Ruprecht-Karls-Universität Heidelberg

Königstuhl Kolloquium


Upcoming events


2024-07-26
11:00
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Ian Crossfield (Kansas)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2024-07-26
11:00
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Ian Crossfield (Kansas)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2024-08-02
11:00
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Julianne Dalcanton (Flatiron)
Königstuhl Kolloquium
MPIA lecture hall,
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2024-08-09
11:00
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David Hogg (NYU, MPIA)
Königstuhl Kolloquium
MPIA lecture hall,
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2024-09-06
11:00
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Nico Winkel (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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2024-09-13
11:00
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Dima Semenov (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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2024-09-13
11:00
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Dima Semenov (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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2024-09-13
11:00
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Shri Kulkarni (Caltech)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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2024-09-20
11:00
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Jes Jørgensen (NBI)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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2024-09-20
11:00
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Jes Jørgensen (NBI)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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2024-09-27
11:00
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: Nicolas Bouche (CRAL)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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2024-09-27
11:00
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: Nicolas Bouche (CRAL)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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2024-10-04
11:00
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Tushar Suhasaria (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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2024-10-11
11:00
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Mario Flock (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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2024-10-11
11:00
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Mario Flock (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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2024-10-18
11:00
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Leonard Burtscher (Astronomers for Planet Earth)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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2024-11-08
11:00
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Tushar Suhasaria (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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2024-11-22
11:00
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Beatriz Campos Estrada (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2024-11-29
15:00
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@3PM
Patzer Colloquium
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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2024-11-29
15:00
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@3PM
Patzer Colloquium
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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2024-12-06
11:00
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Heidelberg-Harvard speaker (CfA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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2024-12-13
11:00
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Paul Mollière (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2025-01-31
11:00
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Sophia Vaughan (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)


Past events


2024-07-19
11:00
TBA
Tushar Suhasaria (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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2024-07-19
11:00
Cold, Dark Carbon at the Earliest Stages of Star Formation
Brett McGuire (MIT) : The PAH Revolution
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Polycyclic Aromatic Hydrocarbons (PAHs) have been implicated as a large reservoir of reactive carbon in the interstellar medium since the 1980s.  PAHs have been widely attributed as the carriers of the unidentified infrared bands where their aggregate vibrational emission spectra are extremely well matched to the observed line signals.  Only in the last year have individual PAHs been detected in the ISM for the first time, however, allowing us to begin to investigate the detailed chemical pathways for the formation and destruction of these molecules.  In this talk, I will discuss our detections of PAH molecules via their rotational transitions using Green Bank Telescope observations of TMC-1 from the GOTHAM collaboration.  I will discuss the efforts to model the chemistry of these PAHs, our application of novel machine learning approaches to exploring the chemical inventory in TMC-1, and finally the benefits of unbiased reaction screening studies in the laboratory with Microwave Spectral Taxonomy.

2024-07-12
11:00
TBA
Maximilian Häberle (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2024-07-12
11:00
New proper motion catalog reveals fast-moving stars around an intermediate-mass black hole in Omega Centauri
Maximilian Häberle (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The intermediate-mass black hole (IMBH) regime is still poorly constrained, with few detections between 150 and 10^5 Msun. This poses a challenge to our understanding of supermassive black hole formation in the early universe.
An IMBH in ? Centauri, the Milky Way's most massive globular cluster, has been suspected for almost two decades, but all previous detections have been questioned due to their assumptions and the possible mass contribution of a central cluster of stellar mass black holes.
I will present a new astrometric catalog for the inner region of ? Centauri, containing 1.4 million proper motion measurements based on 20 years of Hubble Space Telescope observations.
Our catalog is supplemented with precise HST photometry in 7 filters, allowing the separation of its complex subpopulations. The catalog is publicly available, providing the largest kinematic dataset for any star cluster.
Our new catalog revealed 7 fast-moving stars in the innermost 3 arcseconds (0.08 pc) of ? Centauri. The inferred velocities of these stars are significantly higher than the expected central escape velocity of the star cluster, so their presence can only be explained by being bound to an IMBH. From the velocities, we can infer a firm lower limit of the black hole mass of ?8,200 Msun. In addition, we compare the full distribution of stellar velocities to N-Body models that suggest the presence of an IMBH with M?50,000 Msun. These results confirm ? Centauri hosts an IMBH which makes this the nearest known massive black hole and, after the Milky Way center, only the second where we can track the orbits of multiple individual bound companions.

2024-07-05
11:00
TBA
Maximilian Häberle (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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2024-07-05
11:00
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Stan Letchev
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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2024-07-05
11:00
The Evolution Revolution and Hints of the Habitable Zone
Eric Gaidos : Planets of M Dwarf Stars
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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The fantastically successful Kepler and TESS missions have populated wide swaths of exoplanet ''phase space" with thousands of objects.  Sheer numbers allow rigorous comparisons of planet and stellar parameters in order to infer intrinsic propertie such as composition or test models of planet formation and evolution. One of the most coveted parameters is host star age, the availability of which allows direct investigation of planet evolution.  Age is also one of the most difficult stellar properties to measure, although space-based surveys such as Gaia and TESS are providing both the stellar populations and data to advance age-dating of stars and hence their planets.  M dwarf stars, as hosts of many of the smallest, most temperate, and possibly most Earth-like planets known, are of particular interest in this regard.  I will describe challenges and advances in age-dating M dwarfs using their rotation, and a new study that has revised the radii of and assigned ages to M dwarf-hosted planets detected by Kepler.  The low luminosities of these stars is allowing planet surveys to probe to and beyond the semi-major axis at which equilibrium temperatures permit water to condense in planetary atmospheres.  This boundary is not only the inner edge of the ''habitable zone" for Earth-like planets, it is where observable changes in the atmospheres of larger planets may occur, hints of which we might be discovering now.

2024-06-28
11:00
TBA
Aarynn Carter (STScI)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2024-06-28
11:00
Physical and chemical evolution of planet‐forming disks
Dima Semenov (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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The formation and composition of planets and their atmospheres are among the most intriguing and challenging scientific topics. The outcome of planet formation and the resulting planetary systems' architectures are set by the initial conditions in the birth sites of planetary systems – planet-forming disks. These planet-forming disks are a natural outcome of the star formation process. The solar nebula, out of which the solar system emerged about 4.5 Gy ago, is one example of such an environment. In addition, hundreds of planet-forming systems are routinely observed nowadays in the dust continuum and multiple atomic and molecular lines (from optics to radio wavelengths). In my KoCo talk, I will show how the observations and theoretical models are used to infer key disk properties and present our current understanding of disk thermal and density structures, masses, dynamics, grain properties, and chemical composition. I will talk about how various processes during star and planet formation affect the resulting spatial distributions and abundances of various ices and gaseous species, ranging from simple inorganic to complex organic molecules. Last but not least, I will also briefly talk about how the physical and chemical properties of these disks are linked to the physical properties and chemical composition of the emerging terrestrial rocky and gas giant planets, as well as primitive bodies such as asteroids and comets.

2024-06-21
11:00
TBA
Selina Nitschai (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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2024-06-21
11:00
Dynamics of the Milky Way Disk and omega Centauri
Selina Nitschai (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Recent surveys and instruments provide an extensive amount of data for our Galaxy that are key to revealing its assembly history. In this talk, I will present the results of my PhD thesis, first, a dynamical model of the Milky Way disk using the spherically-aligned Jeans Anisotropic Method and combined Gaia EDR3 and APOGEE data throughout Galactocentric radii between 5.0<\; R<\;19.5 kpc. Further, I focus on omega Centauri, the most massive globular cluster in the Milky Way, which has long been suspected to be the stripped nucleus of a dwarf galaxy. I present a MUSE spectroscopic dataset with more than 300,000 extracted stellar spectra. Using this dataset, I investigate the underlying metallicity distributions as well as the spatial variations of the populations within omega Cen for the red giant branch stars. Our unprecedented dataset combining spectroscopy with a new astro-photometric catalog is enabling innovative studies that will transform our understanding of omega Cen.

2024-06-14
11:00
TBD
Christina Eilers (MIT)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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2024-06-14
11:00
The Formation and Growth of Supermassive Black Holes
Christina Eilers (MIT)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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The existence of luminous quasars hosting supermassive black holes (SMBHs) within the first billion years of cosmic history challenges our understanding of black hole growth. An important piece to the puzzle is the duty cycle of quasars, the fraction of cosmic time that galaxies shine as active quasars and during which the bulk of the black hole growth occurs. I will present two new avenues towards understanding the early growth phases of SMBHs: Firstly, I will show a novel method to constrain the timescales of quasar activity using the extent of the ionized regions around quasars, and, secondly, I will present the first quasar clustering measurement at z>6 using recent observations from the James Webb Space Telescope that allow us to estimate the quasars' host dark matter halo mass and their duty cycle. We find that SMBHs seem to grow on much shorter timescales than expected, providing a potential solution to the long-standing puzzle of early black hole growth. I will show how we aim to understand the dominant processes that govern black hole growth using a combination of multi-wavelength observations and data-driven models.

2024-06-07
11:00
TBA
Sarah Casewell (Leicester)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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KoCo Signature Speaker

2024-06-07
11:00
"Irradiated brown dwarfs: Providing insights into exoplanet atmospheres"
Sarah Casewell (Leicester)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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KoCo Signature Speaker
Abstract:

Brown dwarfs are often described as failed stars, however the flip side of this description is that they can also be described as over-ambitious planets. With masses between 13-70 Jupiter masses they have cool atmospheres dominated by cloud features, molecules and show features due to weather.  These atmospheres have a lot of similarities with atmospheres we see in planets in our solar system, and also directly imaged exoplanets.  The question then is: How like hot Jupiters are irradiated brown dwarfs? 

In this seminar I will describe the known irradiated brown dwarfs and how they evolve into post-common envelope systems containing a white dwarf. These rare binaries have very short periods (~hrs) and the brown dwarf is irradiated by the white dwarf companion, often with large amounts of UV radiation. I will discuss the atmospheres of these highly irradiated brown dwarfs and their similarities with irradiated exoplanets.


2024-05-31
11:00
TBA
Antoine Dumont (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2024-05-31
11:00
Modeling and Laboratory Investigation of the Nonlinear Curvature Wavefront Sensor
Stan Letchev
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2024-05-24
11:00
TBA
Raphael Hviding (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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2024-05-24
11:00
The Present and Future of mid-IR AGN Selection with Optical Spectroscopy
Raphael Hviding (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Obscured AGN activity remains a vital, yet elusive, part of understanding the co-evolution of galaxies and their central supermassive black holes through cosmic time. Traditional all-sky mid-IR selection has been successful and recovering obscured SMBH growth, leading to some of the largest AGN catalogs in existence. However, mid-IR selection suffers due to contamination from the host-galaxy. With the advent of new, deep, wide-area, optical/near-IR photometric surveys, it becomes critical to leverage existing mid-IR data  to develop new AGN selection techniques to recover populations of accreting SMBHs that are systematically missed in traditional selection. In this talk I will explore the present state mid-IR AGN selection along with new techniques leveraging existing data with upcoming wide-area surveys for uncovering the hidden accretion in our universe.

2024-05-17
11:00
TBA
Ryan Hickox (Dartmouth)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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KoCo signature speaker (GC)

2024-05-17
11:00
Hidden black holes and their evolution over cosmic time
Ryan Hickox (Dartmouth)
Königstuhl Kolloquium
MPIA lecture hall,
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Abstract
At the heart of essentially every large galaxy in the Universe lies a supermassive black hole. In recent years, surveys of the extragalactic sky have made great progress in understanding the cosmic growth of these black holes, as they accrete surrounding material and radiate as active galactic nuclei (AGN). A major challenge, however, is that the bulk of black hole growth takes place behind heavy obscuration. I will present observational evidence that much, or even most, of these AGN are very heavily obscured (Compton-thick) and thus hidden from many previous multiwavelength surveys. I will discuss the implications for cosmic black hole growth and the populations of AGN now detected in the early Universe with JWST.

KoCo signature speaker (GC)

2024-05-10
11:00
TBD
Tom Megeath (Uni of Toledo)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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2024-05-10
11:00
Observing Protostars in the JWST era
Tom Megeath (Uni of Toledo)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Abstract: Protostars play an important role in cosmic evolution. It is during the protostellar phase that most of a stars mass is accreted, and feedback driven by this accretion is thought to lower the star formation efficiency and shape the IMF.  Outflows from protostars also help regulate star formation in molecular clouds. Finally, the material for planet formation is assembled into disks during the protostellar phase.  I will present current results from the IPA (Investigating Protostellar Accretion) program which is studying five protostars across the mass spectrum at 2.9-28 microns with the JWST IFUs. These data probe both the feedback from young stars and the chemistry of ices on dust grains. I will overview how JWST, combined with ALMA and time-domain IR data, can probe the complicated network of processes in protostars, from several thousand au to stellar scales. I will then present the forthcoming HEFE large program on JWST, and discuss the future potential of the observatory to study galactic star formation.

2024-04-26
11:00
TBA
James Kirk (Imperial)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2024-04-26
11:00
TBA
James Kirk (Imperial)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2024-04-26
11:00
Are exoplanet atmospheres a reliable tracer of exoplanet formation? Observing aligned vs misaligned hot Jupiters as a testbed
James Kirk (Imperial)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
A primary objective of exoplanet atmosphere characterisation is to learn about planet formation and evolution. However, this is challenged by the uncertainties and degeneracies inherent to protoplanetary disc composition, planet formation and planetary evolution. To determine whether atmospheric composition is actually a reliable tracer of formation history, we are undertaking a new survey with JWST to compare the compositions of aligned (low obliquity) and misaligned (high obliquity) hot Jupiters for which we are confident they have undergone different evolutionary pathways. It is believed that aligned planets are the outcome of migration through a protoplanetary disc, while misaligned ones arise from high-eccentricity migration after disc dispersal. This dichotomy leads to differences in the material they accrete during their evolution, which in turn should lead to differences in their atmospheric compositions. I will give an overview of our survey, present predictions from disc chemistry models, and share the first transmission spectra.

2024-04-19
11:00
TBD
Shanghuo Li (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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2024-04-19
11:00
Massive Stellar Cluster Formation — From Filament to Binary
Shanghuo Li (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Massive stars (M > 8 Msun) in the Milky Way are overwhelmingly (>80%) found in binaries or higher-order multiplicity systems, which play a curial role in governing cluster dynamics and stellar evolution.  Massive stars and their clusters are known to form from molecular clouds. However, our understanding of their formation processes, from ~10 pc scale molecular clouds to 100 AU scale multiple systems, is still limited. To investigate the formation of massive stars and their associated clusters across multiple scales, we conducted a systematic program using  interferometer observations. Our studies have provided promising insights into the formation of massive protostars and protoclusters at various evolutionary stages and physical scales. In this talk, I will present a detailed overview of our recent studies on massive star-forming regions using ALMA observations, ranging from ~10 pc scale down to scales of ~100 AU.

2024-04-12
11:00
DSA-2000
Fabian Walter (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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TBD

2024-04-12
11:00
The DSA-2000: A Radio Survey Camera
Fabian Walter (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
I will describe the DSA-2000 project, a proposed world-leading radio survey telescope and multi-messenger discovery engine. The array will consist of 2000 × 5m dishes instantaneously covering the 0.7 - 2 GHz frequency range, spanning an area of 19 km × 15 km in Nevada. In an initial five-year survey, the DSA-2000 will image ~30,000 deg^2 repeatedly over sixteen epochs, producing a deep 20cm sky image at 3.3 arcsecond spatial resolution. Fundamental questions surrounding the baryon cycle in galaxies, the formation of stars over cosmic time, and the influence of active SMBHs on galaxies, will be addressed by detecting over a billion star-forming galaxies and active SMBHs, and by observing the neutral-hydrogen kinematics and contents of several million galaxies. The array will revolutionize the field of radio transients, detecting >10,000 FRBs and >1 million slow transients, with sub-arcsecond localization for host galaxy identification. The DSA-2000 will be also be a leading instrument for the discovery and characterization of the electromagnetic counterparts to neutron-star mergers found by ground-based GW detectors. The DSA-2000 is enabled by two breakthrough technologies, i) a low-cost antenna with an ambient temperature receiver and ii) a new generation of digital back-end known as a radio camera, that outputs image data in real time. I will also discuss our recent efforts towards building an HI radio camera for the DSA-110, the DSA-2000 precursor.

2024-04-05
11:00
Recent research results from the HKU Late State stellar evolution team - Strange Galactic alignments and solving the sulphur anomaly in Planetary Nebulae
Quentin Parker (Hong Kong)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Planetary Nebulae (Pne) are a relatively rare but powerful late-stage stellar population in terms of what we can learn about stellar evolution and the chemical enrichment process of entire Galaxies. Their ionised shells exhibit numerous and strong emission lines over a wide range of the electromagnetic spectrum. As such they represent highly useful “laboratories” for studying the plasma physics of these celestial objects.  Because most radiation from PNe is emitted via their strong emission lines they can be found to enormous distances outside of our own Galaxy. Their rich variety of lines also enables estimation of elemental abundances, expansion velocity of the nebula and associated kinematic age. HASH (Hong Kong/AAO/Strasbourg H-alpha PN catalogue) is a PNe mutliwavelength database of all currently known Galactic and Magellanic Cloud PNe. It has provided a powerful online resource for the global community to study both PNe and their CSPN with over 1100 users in more than 60 countries.

In this talk I will present some key, recent results from various HKU based projects on PNe facilitated via our ESO VLT data and HASH. I will cover a recent, enigmatic 5-sigma PNe alignment result in the Galactic centre, our robust abundance determinations and resolution of a decades old  so-called “sulphur anomaly” problem.

2024-04-05
11:00
Recent research results from the HKU Late State stellar evolution team - Strange Galactic alignments and solving the sulphur anomaly in Planetary Nebulae
Quentin Parker (Hong Kong)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Planetary Nebulae (Pne) are a relatively rare but powerful late-stage stellar population in terms of what we can learn about stellar evolution and the chemical enrichment process of entire Galaxies. Their ionised shells exhibit numerous and strong emission lines over a wide range of the electromagnetic spectrum. As such they represent highly useful “laboratories” for studying the plasma physics of these celestial objects.  Because most radiation from PNe is emitted via their strong emission lines they can be found to enormous distances outside of our own Galaxy. Their rich variety of lines also enables estimation of elemental abundances, expansion velocity of the nebula and associated kinematic age. HASH (Hong Kong/AAO/Strasbourg H-alpha PN catalogue) is a PNe mutliwavelength database of all currently known Galactic and Magellanic Cloud PNe. It has provided a powerful online resource for the global community to study both PNe and their CSPN with over 1100 users in more than 60 countries.

In this talk I will present some key, recent results from various HKU based projects on PNe facilitated via our ESO VLT data and HASH. I will cover a recent, enigmatic 5-sigma PNe alignment result in the Galactic centre, our robust abundance determinations and resolution of a decades old  so-called “sulphur anomaly” problem.

2024-03-22
11:00
What do the neighbors look like? A comparative look at the Milky Way and Andromeda dwarf galaxies
Nicolas Martin (Obs. Strasbourg)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Dwarf galaxies are powerful tools of near-field cosmology and galactic archaeology: their numbers, distribution, and star formation can be linked to both the tenets of LCDM (the missing satellite "problem," their (an)isotropic distribution, their dark matter content) and to the build up of their hosts and their environment (accretion, quenching). The exquisite detail offered by observation of the nearby Milky Way dwarf galaxies has built a picture of what dwarf galaxies are and how they evolved through time. In this talk, I will review the increasingly sharp view we are building of the dwarf-galaxy system of the Milky Way's "sister" galaxy, Andromeda, and emphasize key similarities and differences between these two systems of satellites in the hope to learn what features are common or, on the contrary, driven by the different pasts of the Milky Way and Andromeda.

2024-03-22
11:00
What do the neighbors look like? A comparative look at the Milky Way and Andromeda dwarf galaxies
Nicolas Martin (Obs. Strasbourg)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Dwarf galaxies are powerful tools of near-field cosmology and galactic archaeology: their numbers, distribution, and star formation can be linked to both the tenets of LCDM (the missing satellite "problem," their (an)isotropic distribution, their dark matter content) and to the build up of their hosts and their environment (accretion, quenching). The exquisite detail offered by observation of the nearby Milky Way dwarf galaxies has built a picture of what dwarf galaxies are and how they evolved through time. In this talk, I will review the increasingly sharp view we are building of the dwarf-galaxy system of the Milky Way's "sister" galaxy, Andromeda, and emphasize key similarities and differences between these two systems of satellites in the hope to learn what features are common or, on the contrary, driven by the different pasts of the Milky Way and Andromeda.

2024-03-15
11:00
A planetary population synthesis look at the exoplanetary radius valley
Remo Burn (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The planetary population synthesis method can help to confront planet formation theory against observations. I will present an overview of recent works and their challenges before focusing on the radius valley in the observed exoplanet distribution. Conventionally, it is explained by the loss of primordial H/He envelopes atop rocky cores. However, this was so far inconsistent with the presence of migrated, water-rich planets which are consistently predicted by planet formation theories. In a recent work, we recover the radius valley at the observed position if we include supercritical steam atmospheres in combination with photoevaporation of mixed H/He and water. The exclusion of the lower-density supercritical phase of water was a shortcoming of previous global models and is identified as a key process.

2024-03-15
11:00
A planetary population synthesis look at the exoplanetary radius valley
Remo Burn (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The planetary population synthesis method can help to confront planet formation theory against observations. I will present an overview of recent works and their challenges before focusing on the radius valley in the observed exoplanet distribution. Conventionally, it is explained by the loss of primordial H/He envelopes atop rocky cores. However, this was so far inconsistent with the presence of migrated, water-rich planets which are consistently predicted by planet formation theories. In a recent work, we recover the radius valley at the observed position if we include supercritical steam atmospheres in combination with photoevaporation of mixed H/He and water. The exclusion of the lower-density supercritical phase of water was a shortcoming of previous global models and is identified as a key process.

2024-03-08
11:00
A landscape of H.E.S.S. results on indirect dark matter searches
Alessandro Montanari (LSW)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Gamma-ray observations with Imaging Atmospheric Cherenkov Telescopes (IACTs) are a unique probe for indirect detection of dark matter (DM) astrophysical signal. The scenario of TeV-scale Weakly Interactive Massive Particles - a compelling class of stable DM candidates - has been extensively explored using observations collected with the High Energy Stereoscopic System (H.E.S.S.), a hybrid array of five IACTs. After more than 20 years of stereoscopic observations, H.E.S.S. collected a variety of datasets from potential targets hosting DM with unprecedented sensitivity. Located in the Southern hemisphere, H.E.S.S. is in a privileged position to observe the Milky Way and the Galactic centre (GC) region. I will present the main results obtained with H.E.S.S. on the search for DM annihilation signals - considering also specific DM candidates like the Wino, Higgsino, and Quintuplet - from targets such as dwarf spheroidal galaxies, candidates DM subhalos in the Milky Way halo, and the GC region. These results establish a benchmark for the ultimate sensitivity of the current generation of IACT instruments to annihilating DM, providing conclusions directly relevant for searches of DM signals with the next generation of Cherenkov telescopes.

2024-03-08
11:00
A landscape of H.E.S.S. results on indirect dark matter searches
Alessandro Montanari (LSW)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Gamma-ray observations with Imaging Atmospheric Cherenkov Telescopes (IACTs) are a unique probe for indirect detection of dark matter (DM) astrophysical signal. The scenario of TeV-scale Weakly Interactive Massive Particles - a compelling class of stable DM candidates - has been extensively explored using observations collected with the High Energy Stereoscopic System (H.E.S.S.), a hybrid array of five IACTs. After more than 20 years of stereoscopic observations, H.E.S.S. collected a variety of datasets from potential targets hosting DM with unprecedented sensitivity. Located in the Southern hemisphere, H.E.S.S. is in a privileged position to observe the Milky Way and the Galactic centre (GC) region. I will present the main results obtained with H.E.S.S. on the search for DM annihilation signals - considering also specific DM candidates like the Wino, Higgsino, and Quintuplet - from targets such as dwarf spheroidal galaxies, candidates DM subhalos in the Milky Way halo, and the GC region. These results establish a benchmark for the ultimate sensitivity of the current generation of IACT instruments to annihilating DM, providing conclusions directly relevant for searches of DM signals with the next generation of Cherenkov telescopes.

2024-03-01
11:00
Euclid - at the start of its surveys
Knud Jahnke (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
ESA's Euclid mission has been launched 9 months ago and has just started its 6-year science surveys, now scanning 10 square degrees every day. I will recap Euclid's cosmology science goals and motivate why 1000+ non-cosmologists are also eagerly waiting to use Euclid's first data. This will include an overview over Euclid's capabilities and limits, the type of data that is generated, and what kind of work to enable the mission is currently done at MPIA. I'll also give an overview of which Euclid-centered or -enabled science is planned at MPIA, how anyone interested can still get involved, including getting early access to data, and whom you can contact to about Euclid and Euclid science. And I will show the first science-ready data that were released in November, and give an outlook of which data should be expected when.

2024-03-01
11:00
Euclid - at the start of its surveys
Knud Jahnke (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
ESA's Euclid mission has been launched 9 months ago and has just started its 6-year science surveys, now scanning 10 square degrees every day. I will recap Euclid's cosmology science goals and motivate why 1000+ non-cosmologists are also eagerly waiting to use Euclid's first data. This will include an overview over Euclid's capabilities and limits, the type of data that is generated, and what kind of work to enable the mission is currently done at MPIA. I'll also give an overview of which Euclid-centered or -enabled science is planned at MPIA, how anyone interested can still get involved, including getting early access to data, and whom you can contact to about Euclid and Euclid science. And I will show the first science-ready data that were released in November, and give an outlook of which data should be expected when.

2024-02-23
11:00
The outer reaches of extrasolar systems: exoplanets, brown dwarfs and debris disks with high-contrast imaging
Elisabeth Matthews (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Direct detection of exoplanets is challenging: there is an enormous contrast barrier and a small angular separation between a star and any planets that are in orbit\; these planets are also rare, and blind surveys for these objects are expensive. However, once detected, imaged planets can provide a wealth of information about the planet atmosphere through detailed photometric and spectroscopic campaigns. To date, only a small handful of exoplanets have been directly detected, and the population consists primarily of young, hot planets which are still re-radiating their formation energy - with very little overlap with the population of indirectly detected planets. However, cold faint planets are some of the most fascinating: they are the most similar to those in our own solar system, providing context for the study of Jupiter and observationally calibrating theoretical evolution models as the planets approach equilibrium temperature. Their atmospheric chemistry is expected to be dominated by molecules such as CH4, H2O and NH3, and water clouds are also predicted. The unprecedented sensitivity of the James Webb Space Telescope allows access to this cold population of exoplanets for the first time — yet selecting appropriate targets for deep imaging campaigns is critical.

In this talk I will highlight our efforts to use ancillary information to target direct imaging campaigns and image cool planets. Radial velocity campaigns, astrometric accelerations, and debris disk signatures can all provide clues as to the best targets to image. Planets in these systems are particularly amenable to detailed characterization: for example, imaging planets in systems with debris disks allows a detailed study of the disk-planet interactions. Imaging planets with RV information allow us to simultaneously measure precise dynamical masses, bolometric luminosities, and atmospheric compositions, and characterize the orbits of these companions, and early measurements challenge evolutionary models. This technique has led to my recent discovery of the cold planet Eps Ind Ac with JWST/MIRI coronagraphic imaging. Eps Ind Ac is the oldest and coldest exoplanet ever directly imaged, and the first confirmed planet discovered with JWST imaging. Early comparison to models indicates a clear tension with both atmospheric and evolutionary models for solar-age exoplanets, but the bright flux and wide separation make this source ideally suited to future characterization efforts that may shed light on this tension.

2024-02-23
11:00
The outer reaches of extrasolar systems: exoplanets, brown dwarfs and debris disks with high-contrast imaging
Elisabeth Matthews (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Direct detection of exoplanets is challenging: there is an enormous contrast barrier and a small angular separation between a star and any planets that are in orbit\; these planets are also rare, and blind surveys for these objects are expensive. However, once detected, imaged planets can provide a wealth of information about the planet atmosphere through detailed photometric and spectroscopic campaigns. To date, only a small handful of exoplanets have been directly detected, and the population consists primarily of young, hot planets which are still re-radiating their formation energy - with very little overlap with the population of indirectly detected planets. However, cold faint planets are some of the most fascinating: they are the most similar to those in our own solar system, providing context for the study of Jupiter and observationally calibrating theoretical evolution models as the planets approach equilibrium temperature. Their atmospheric chemistry is expected to be dominated by molecules such as CH4, H2O and NH3, and water clouds are also predicted. The unprecedented sensitivity of the James Webb Space Telescope allows access to this cold population of exoplanets for the first time — yet selecting appropriate targets for deep imaging campaigns is critical.

In this talk I will highlight our efforts to use ancillary information to target direct imaging campaigns and image cool planets. Radial velocity campaigns, astrometric accelerations, and debris disk signatures can all provide clues as to the best targets to image. Planets in these systems are particularly amenable to detailed characterization: for example, imaging planets in systems with debris disks allows a detailed study of the disk-planet interactions. Imaging planets with RV information allow us to simultaneously measure precise dynamical masses, bolometric luminosities, and atmospheric compositions, and characterize the orbits of these companions, and early measurements challenge evolutionary models. This technique has led to my recent discovery of the cold planet Eps Ind Ac with JWST/MIRI coronagraphic imaging. Eps Ind Ac is the oldest and coldest exoplanet ever directly imaged, and the first confirmed planet discovered with JWST imaging. Early comparison to models indicates a clear tension with both atmospheric and evolutionary models for solar-age exoplanets, but the bright flux and wide separation make this source ideally suited to future characterization efforts that may shed light on this tension.

2024-02-09
11:00
"Cosmic train-wrecks - cosmology & astrophysics with merging galaxy clusters"
Urmila Chadayammuri (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The Bullet Cluster, Pandora's Cluster, the Trainwreck Cluster - merging galaxy clusters are some of the most spectacular events in the Universe, the most energetic things to occur since the Big Bang. Because these systems are very far from equilibrium, interpreting their observations is much more challenging than in their relaxed counterparts. Powered by idealised and numerical simulations, however, they are uniquely powerful in constraining such properties as the self-interaction cross-section of dark matter, the viscosity of the intracluster medium and the strength of cosmic magnetic fields. Due to their enhanced triaxiality, they are also the most potent gravitational lenses in the Universe, revealing the galaxy and quasar populations otherwise too faint to observe, including now several candidates just half a billion years after the Big Bang. In this talk, I show examples of each of these use cases, and show how the path forward is being accelerated with machine learning and simulation-based inference.

2024-02-09
11:00
"Cosmic train-wrecks - cosmology & astrophysics with merging galaxy clusters"
Urmila Chadayammuri (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
The Bullet Cluster, Pandora's Cluster, the Trainwreck Cluster - merging galaxy clusters are some of the most spectacular events in the Universe, the most energetic things to occur since the Big Bang. Because these systems are very far from equilibrium, interpreting their observations is much more challenging than in their relaxed counterparts. Powered by idealised and numerical simulations, however, they are uniquely powerful in constraining such properties as the self-interaction cross-section of dark matter, the viscosity of the intracluster medium and the strength of cosmic magnetic fields. Due to their enhanced triaxiality, they are also the most potent gravitational lenses in the Universe, revealing the galaxy and quasar populations otherwise too faint to observe, including now several candidates just half a billion years after the Big Bang. In this talk, I show examples of each of these use cases, and show how the path forward is being accelerated with machine learning and simulation-based inference.

2024-02-02
11:00
A new "Ice Age" or an astronomical meltdown? Tracing CHONs chemistry from clouds to exoplanets with JWST
Melissa McClure (Leiden Observatory)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Volatile elements, like C, H, O, N, and S, are critical to the detectability of planetary atmospheres and the origins of life as we know it. These elements are mostly carried by icy dust grains that may have been transferred to Earth from the cold outer regions of the Solar protoplanetary disk. Much of this ice likely originated in the Sun's natal molecular cloud\; however, the total amount, variety, and complexity of ices inherited this way is an open question. These questions are critical to understanding planetary habitability and the rise of life, and they could allow us to use the atmospheric composition of giant planets to trace their formation zones in protoplanetary disks.

Infrared spectroscopy of clouds, protostars, and protoplanetary disks with JWST allows us to answer these questions. I will present initial results from several Cycle 1 JWST programs, including the ERS program Ice Age (http://jwst-iceage.org/), showcasing the exquisite data quality from JWST. These observations reveal the diversity of icy chemistry found in dark regions of molecular clouds and the distribution and bulk composition of ice and gas in protostars and disks. We see early chemical pathways to complex ices and CO2 in the cloud while the distribution of CO ice in the protoplanetary disk, suggests that it is trapped in the CO2 ice matrix on the dust grains. 

These results provide additional complications in the community's efforts to connect exoplanets' atmospheric compositions with their formation histories.

2024-02-02
11:00
A new "Ice Age" or an astronomical meltdown? Tracing CHONs chemistry from clouds to exoplanets with JWST
Melissa McClure (Leiden Observatory)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Volatile elements, like C, H, O, N, and S, are critical to the detectability of planetary atmospheres and the origins of life as we know it. These elements are mostly carried by icy dust grains that may have been transferred to Earth from the cold outer regions of the Solar protoplanetary disk. Much of this ice likely originated in the Sun's natal molecular cloud\; however, the total amount, variety, and complexity of ices inherited this way is an open question. These questions are critical to understanding planetary habitability and the rise of life, and they could allow us to use the atmospheric composition of giant planets to trace their formation zones in protoplanetary disks.

Infrared spectroscopy of clouds, protostars, and protoplanetary disks with JWST allows us to answer these questions. I will present initial results from several Cycle 1 JWST programs, including the ERS program Ice Age (http://jwst-iceage.org/), showcasing the exquisite data quality from JWST. These observations reveal the diversity of icy chemistry found in dark regions of molecular clouds and the distribution and bulk composition of ice and gas in protostars and disks. We see early chemical pathways to complex ices and CO2 in the cloud while the distribution of CO ice in the protoplanetary disk, suggests that it is trapped in the CO2 ice matrix on the dust grains. 

These results provide additional complications in the community's efforts to connect exoplanets' atmospheric compositions with their formation histories.

2024-01-26
11:00
Unveiling the secrets of massive stars as cosmic engines
Andreas Sander (ARI)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Albeit rare in absolute numbers, massive stars are shaping our cosmic history as they are connected to many astrophysical key processes. Commonly defined as stars with an initial mass of more than 8 times the mass of our Sun, massive stars are the progenitors of black holes and neutron stars, reaching all nuclear burning stages before eventually undergoing their inevitable core collapse. In their relative short, but wild life, these luminous objects have an enormous impact on their galactic environment, enriching the surrounding medium with momentum, matter and ionizing radiation. This so-called "feedback" of massive stars is a building block for the evolution of galaxies, initiating and inhibiting further star formation. In the "afterlives" of massive stars, black holes and neutron stars can merge with each other, giving rise a to Gravitational Wave events.

Many details of massive stars as well as their impact and evolution are still poorly understood. In fact, the overall picture we draw in textbooks often does not hold once we actually try to bring all the observational and theoretical constraints together. We nowadays know that many massive stars have one or more companion and interactions between massive stars are common. While this gives rise to different evolutionary channels, many challenges remain. Further unconventional puzzle pieces and surprising constraints have arrived from observational frontiers such as the strong metal-enrichment in high-redshift galaxies discovered by JWST or the black hole statistics obtained from Gravitational Waves.

Investigating the massive star puzzle with a combined approach of theory, observation and numerics is at the very heart of my research group at the ARI. Our central tool in this endeavour is the application and development of dedicated stellar atmosphere models. I will briefly introduce the techniques and challenges of atmosphere modelling for hot, massive stars and their winds as well as their empirical and theoretical applications. Afterwards, I will provide an overview about the multi-ranged research efforts in my group, ranging from the spectral analysis of individual stars and the identification of "hidden" companions over theoretical studies on radiation-driven winds up to the generation of synthetic stellar libraries and new predictions for stellar feedback.

2024-01-26
11:00
Unveiling the secrets of massive stars as cosmic engines
Andreas Sander (ARI)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Albeit rare in absolute numbers, massive stars are shaping our cosmic history as they are connected to many astrophysical key processes. Commonly defined as stars with an initial mass of more than 8 times the mass of our Sun, massive stars are the progenitors of black holes and neutron stars, reaching all nuclear burning stages before eventually undergoing their inevitable core collapse. In their relative short, but wild life, these luminous objects have an enormous impact on their galactic environment, enriching the surrounding medium with momentum, matter and ionizing radiation. This so-called "feedback" of massive stars is a building block for the evolution of galaxies, initiating and inhibiting further star formation. In the "afterlives" of massive stars, black holes and neutron stars can merge with each other, giving rise a to Gravitational Wave events.

Many details of massive stars as well as their impact and evolution are still poorly understood. In fact, the overall picture we draw in textbooks often does not hold once we actually try to bring all the observational and theoretical constraints together. We nowadays know that many massive stars have one or more companion and interactions between massive stars are common. While this gives rise to different evolutionary channels, many challenges remain. Further unconventional puzzle pieces and surprising constraints have arrived from observational frontiers such as the strong metal-enrichment in high-redshift galaxies discovered by JWST or the black hole statistics obtained from Gravitational Waves.

Investigating the massive star puzzle with a combined approach of theory, observation and numerics is at the very heart of my research group at the ARI. Our central tool in this endeavour is the application and development of dedicated stellar atmosphere models. I will briefly introduce the techniques and challenges of atmosphere modelling for hot, massive stars and their winds as well as their empirical and theoretical applications. Afterwards, I will provide an overview about the multi-ranged research efforts in my group, ranging from the spectral analysis of individual stars and the identification of "hidden" companions over theoretical studies on radiation-driven winds up to the generation of synthetic stellar libraries and new predictions for stellar feedback.

2024-01-19
11:00
TBD
No KoCo
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2024-01-19
11:00
TBD
No KoCo
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2024-01-12
11:00
Quasars at Cosmic Dawn - before and after JWST
Eduardo Banados (MPIA)
Königstuhl Kolloquium
MPIA lecture hall,
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Abstract
Quasars are among the most powerful and luminous objects in the Universe. As such, they can be found and studied in detail far back into the epoch of reionization at redshifts z>6. These luminous quasars are ideal laboratories to study the build-up of the first massive galaxies and black holes and the onset of small- and large-scale structures in the early Universe. I will review our "pre-JWST" knowledge of the physical properties of the most distant quasars (black holes, host galaxies, and their environment). I will also highlight recent results, including from JWST, and briefly describe what to expect from the European Euclid mission. The next few years will be critical for advancing our understanding of quasars at cosmic dawn.

2024-01-12
11:00
Quasars at Cosmic Dawn - before and after JWST
Eduardo Banados (MPIA)
Königstuhl Kolloquium
MPIA lecture hall,
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Abstract
Quasars are among the most powerful and luminous objects in the Universe. As such, they can be found and studied in detail far back into the epoch of reionization at redshifts z>6. These luminous quasars are ideal laboratories to study the build-up of the first massive galaxies and black holes and the onset of small- and large-scale structures in the early Universe. I will review our "pre-JWST" knowledge of the physical properties of the most distant quasars (black holes, host galaxies, and their environment). I will also highlight recent results, including from JWST, and briefly describe what to expect from the European Euclid mission. The next few years will be critical for advancing our understanding of quasars at cosmic dawn.

2024-01-12
11:00
TBD
Eduardo Banados (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2023-12-08
11:00
The cradle of black holes: Growing intermediate-mass black holes in dense star cluster simulations
Albrecht Kamlah (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Since the first detection of gravitational waves emitted during the merger of two black holes, understanding the formation channels of such systems has become one of the most pressing questions in theoretical astrophysics. In the 19 pioneering Dragon-II simulations published this year and which I will present, we have demonstrated that the black holes the merge in our simulations can fit the observed gravitational wave sources very well. This has many implications for the entire field of computational astronomy, but also astrophysics in general. Unlike observations, we can resolve the entire lifecycle of the black holes (and other compact objects) that are gravitational wave sources from birth to eventual demise. This helps us to unravel one of the fundamental questions in astrophysics of how massive black holes form and gets us close to the question where supermassive black holes originate from. I will also highlight results from an as of yet mostly ignored parameter in such simulations, which is initial star cluster rotation and which yields exciting phenomena. Lastly, I will provide insights into the evolution of the first (Population-III) star clusters in the Universe and first results from growing actual supermassive black hole seeds within star clusters.

2023-12-08
11:00
The cradle of black holes: Growing intermediate-mass black holes in dense star cluster simulations
Albrecht Kamlah (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Since the first detection of gravitational waves emitted during the merger of two black holes, understanding the formation channels of such systems has become one of the most pressing questions in theoretical astrophysics. In the 19 pioneering Dragon-II simulations published this year and which I will present, we have demonstrated that the black holes the merge in our simulations can fit the observed gravitational wave sources very well. This has many implications for the entire field of computational astronomy, but also astrophysics in general. Unlike observations, we can resolve the entire lifecycle of the black holes (and other compact objects) that are gravitational wave sources from birth to eventual demise. This helps us to unravel one of the fundamental questions in astrophysics of how massive black holes form and gets us close to the question where supermassive black holes originate from. I will also highlight results from an as of yet mostly ignored parameter in such simulations, which is initial star cluster rotation and which yields exciting phenomena. Lastly, I will provide insights into the evolution of the first (Population-III) star clusters in the Universe and first results from growing actual supermassive black hole seeds within star clusters.

2023-12-08
11:00
TBD
Albrecht Kamlah (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2023-12-01
11:00
"Revealing the 3D structure of exo-atmosphere.""
Vivien Parmentier (Université C?'te d'Azur)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Abstract: 

All planetary atmospheres are 3D in nature. This is particularly true for the majority of exoplanets we observe today : tidally-locked, close in, giant planets. Atmospheric flow from the dayside to nightside of these worlds shape the 3D thermal, chemical and cloud structure. Understanding this 3D structure is crucial to properly interpret current and future observations.


I will show how recent breakthrough in telescopes and instrumentations allow us directly measure dynamical quantities and map the 3D structure of exoplanets. I will particularly highlight how wind speeds can be directly measured from ground-based high-spectral resolution observations and how temperature, chemical and cloud maps can be obtained through JWST observations, including the recently observed NIRspec/PRISM phase curve of the hot Jupiter NGTS-10b.

Signature Speaker


2023-12-01
11:00
"Revealing the 3D structure of exo-atmosphere.""
Vivien Parmentier (Université C?'te d'Azur)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Abstract: 

All planetary atmospheres are 3D in nature. This is particularly true for the majority of exoplanets we observe today : tidally-locked, close in, giant planets. Atmospheric flow from the dayside to nightside of these worlds shape the 3D thermal, chemical and cloud structure. Understanding this 3D structure is crucial to properly interpret current and future observations.


I will show how recent breakthrough in telescopes and instrumentations allow us directly measure dynamical quantities and map the 3D structure of exoplanets. I will particularly highlight how wind speeds can be directly measured from ground-based high-spectral resolution observations and how temperature, chemical and cloud maps can be obtained through JWST observations, including the recently observed NIRspec/PRISM phase curve of the hot Jupiter NGTS-10b.

Signature Speaker


2023-12-01
11:00
TBD
Vivien Parmentier (Université C?'te d'Azur)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2023-11-24
15:00
TBD
Patzer Colloquium (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2023-11-24
15:00
TBD
Patzer Colloquium (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
TBD

2023-11-24
11:00
TBD
Patzer Colloquium (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
TBD

2023-11-24
11:00
TBD
Patzer Colloquium (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
TBD

2023-11-24
11:00
TBD
Patzer Colloquium (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
TBD

2023-11-17
11:00
Exoplanet transit spectroscopy in the era of JWST
Eva-Maria Ahrer (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Abstract: JWST started its science operations a year ago. Since then, there's been a large influx of atmospheric characterisation of exoplanets in the infrared, previously only partially accessible with high-resolution spectrographs or space telescopes such as Spitzer. Highlights of early JWST results include detections of carbon dioxide, the lack of detection of methane in some planets and the detection of sulphur dioxide, a product of photochemistry. The implications of these precise observations broad, from planet formation and migration history to challenging our atmospheric models.

In this talk I will give an overview of the first spectra of transiting exoplanets taken with JWST as part of the Transiting Exoplanet Community Early Release Science (TEC ERS) program, including the research I led. I will also show recent JWST observations that demonstrate its capabilities and the new insights we can
 gather about exoplanetary atmospheres, with a focus on transiting gas giants.

In addition to showing new, shiny JWST results, I will also take some time in this talk to discuss synergies between JWST and other telescopes and demonstrate that observations in the bluer wavelength ranges are also necessary to fully characterise an exoplanet's atmosphere.

In the final part of this talk, I will show a few examples of upcoming JWST exoplanetary science that I'm particularly excited about.

2023-11-17
11:00
Exoplanet transit spectroscopy in the era of JWST
Eva-Maria Ahrer (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Abstract: JWST started its science operations a year ago. Since then, there's been a large influx of atmospheric characterisation of exoplanets in the infrared, previously only partially accessible with high-resolution spectrographs or space telescopes such as Spitzer. Highlights of early JWST results include detections of carbon dioxide, the lack of detection of methane in some planets and the detection of sulphur dioxide, a product of photochemistry. The implications of these precise observations broad, from planet formation and migration history to challenging our atmospheric models.

In this talk I will give an overview of the first spectra of transiting exoplanets taken with JWST as part of the Transiting Exoplanet Community Early Release Science (TEC ERS) program, including the research I led. I will also show recent JWST observations that demonstrate its capabilities and the new insights we can
 gather about exoplanetary atmospheres, with a focus on transiting gas giants.

In addition to showing new, shiny JWST results, I will also take some time in this talk to discuss synergies between JWST and other telescopes and demonstrate that observations in the bluer wavelength ranges are also necessary to fully characterise an exoplanet's atmosphere.

In the final part of this talk, I will show a few examples of upcoming JWST exoplanetary science that I'm particularly excited about.

2023-11-17
11:00
TBD
Vivien Parmentier (University of Oxford)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2023-11-17
11:00
TBD
Eva-Maria Ahrer (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
TBD

2023-11-10
11:00
Tools for Understanding the Cosmic History of Molecular Gas
Ryan Keenan (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract

As the fuel for star formation, molecular gas plays a crucial role in the evolution of galaxies. Advanced millimeter-wave facilities now make it possible to study the gas properties of large samples of nearby galaxies and to peer into the cold ISM of “typical” star forming galaxies throughout cosmic time. However, many details of the interplay between gas and star formation that drives galaxy evolution remain unsettled. In this talk, I will present my work refining our tools for measuring and interpreting the observational signatures of molecular gas. I will begin by reviewing recent efforts to measure the cosmic abundance of molecular gas, and its evolution over time. Pioneering studies with ALMA, NOEMA, and the VLA have now constrained the global history of molecular gas to cosmic noon and beyond. Achieving precision measurements of this history will require extensive surveys which push the limits of current facilities. I have developed mocks for current and future surveys to help guide the design of the next generation of molecular gas deep fields. Precision measurements of the cosmic molecular gas history require surveys over significantly larger volumes than have been achieved to date, and I will discuss possible avenues for accomplishing such a survey. The novel technique of “line intensity mapping” (LIM), which can constrain the agreagate gas content of galaxies too faint to be individually detected, provides one path forward using existing facilities. I will provide an overview of the LIM technique, highlight a few upcoming line intensity mapping projects, and present upper limits on the CO-galaxy cross-power spectrum at redshift 2 derived from the exploratory CO Power Spectrum Survey, which serve as a proof of concept for future projects.

 

While much of our understanding of molecular gas comes from studies using the CO(1-0) line, other tracers gas tracers such as the higher energy CO lines, are increasingly popular. In the second half of my talk I will introduce the Arizona Molecular ISM Survey with the SMT (AMISS), a multi-line study of 177 nearby galaxies designed cross-calibrate the CO(1-0), CO(2-1), and CO(3-2) lines as tracers of molecular gas. The large sample and careful calibration of AMISS make it possible to robustly measure correlations between the excitation of CO emitting gas and host galaxy properties on a galaxy integrated scale. The three lines are not perfectly interchangeable tracers and the luminosity ratios between them vary systematically over the galaxy population. Using the AMISS sample, I characterize these trends, providing an empirical prescription for translating between gas measurements made with different CO lines, and then explore the utility of CO line ratios as diagnostics of conditions in the interstellar media of galaxies.


2023-11-10
11:00
Tools for Understanding the Cosmic History of Molecular Gas
Ryan Keenan (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract

As the fuel for star formation, molecular gas plays a crucial role in the evolution of galaxies. Advanced millimeter-wave facilities now make it possible to study the gas properties of large samples of nearby galaxies and to peer into the cold ISM of “typical” star forming galaxies throughout cosmic time. However, many details of the interplay between gas and star formation that drives galaxy evolution remain unsettled. In this talk, I will present my work refining our tools for measuring and interpreting the observational signatures of molecular gas. I will begin by reviewing recent efforts to measure the cosmic abundance of molecular gas, and its evolution over time. Pioneering studies with ALMA, NOEMA, and the VLA have now constrained the global history of molecular gas to cosmic noon and beyond. Achieving precision measurements of this history will require extensive surveys which push the limits of current facilities. I have developed mocks for current and future surveys to help guide the design of the next generation of molecular gas deep fields. Precision measurements of the cosmic molecular gas history require surveys over significantly larger volumes than have been achieved to date, and I will discuss possible avenues for accomplishing such a survey. The novel technique of “line intensity mapping” (LIM), which can constrain the agreagate gas content of galaxies too faint to be individually detected, provides one path forward using existing facilities. I will provide an overview of the LIM technique, highlight a few upcoming line intensity mapping projects, and present upper limits on the CO-galaxy cross-power spectrum at redshift 2 derived from the exploratory CO Power Spectrum Survey, which serve as a proof of concept for future projects.

 

While much of our understanding of molecular gas comes from studies using the CO(1-0) line, other tracers gas tracers such as the higher energy CO lines, are increasingly popular. In the second half of my talk I will introduce the Arizona Molecular ISM Survey with the SMT (AMISS), a multi-line study of 177 nearby galaxies designed cross-calibrate the CO(1-0), CO(2-1), and CO(3-2) lines as tracers of molecular gas. The large sample and careful calibration of AMISS make it possible to robustly measure correlations between the excitation of CO emitting gas and host galaxy properties on a galaxy integrated scale. The three lines are not perfectly interchangeable tracers and the luminosity ratios between them vary systematically over the galaxy population. Using the AMISS sample, I characterize these trends, providing an empirical prescription for translating between gas measurements made with different CO lines, and then explore the utility of CO line ratios as diagnostics of conditions in the interstellar media of galaxies.


2023-11-03
11:00
Inner Disk Chemistry in the JWST Era
Giulia Perotti (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Protoplanetary disks represent the evolutionary link between molecular clouds and planets. Knowledge of their molecular inventory is the key to unveil the chemical trail leading to life, yet too few observational constraints of disks exist at infrared wavelengths. This wavelength regime enables to study the solid and gas reservoirs where terrestrial planets and sub-Neptunes form. Compared to previous IR facilities, the JWST MIRI instrument offers unprecedented sensitivity, spatial resolution (R=3400-1600), and spectral coverage (5-28 µm). In this KoCo, I will present the first MIRI MRS observations of the PDS 70 planet-forming disk as part of the MIRI Mid-INfrared Disk Survey (MINDS). The much higher spectral resolution of MIRI MRS compared with previous Spitzer spectroscopy (R=100, 600) reveals emission of water vapour. This demonstrates that the terrestrial planet-forming zone of PDS 70 has maintained to some degree the physical and chemical conditions of young disks, in spite of the 54 au planet-induced gap.

2023-11-03
11:00
Inner Disk Chemistry in the JWST Era
Giulia Perotti (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Protoplanetary disks represent the evolutionary link between molecular clouds and planets. Knowledge of their molecular inventory is the key to unveil the chemical trail leading to life, yet too few observational constraints of disks exist at infrared wavelengths. This wavelength regime enables to study the solid and gas reservoirs where terrestrial planets and sub-Neptunes form. Compared to previous IR facilities, the JWST MIRI instrument offers unprecedented sensitivity, spatial resolution (R=3400-1600), and spectral coverage (5-28 µm). In this KoCo, I will present the first MIRI MRS observations of the PDS 70 planet-forming disk as part of the MIRI Mid-INfrared Disk Survey (MINDS). The much higher spectral resolution of MIRI MRS compared with previous Spitzer spectroscopy (R=100, 600) reveals emission of water vapour. This demonstrates that the terrestrial planet-forming zone of PDS 70 has maintained to some degree the physical and chemical conditions of young disks, in spite of the 54 au planet-induced gap.

2023-11-03
11:00
tbd
Giulia Perotti (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
tbd

2023-10-27
11:00
TBD
TBD (TBD)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2023-10-20
11:00
Zooming in on the Baryon Cycle in Galaxies
Christopher Faesi (UConn)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The cycling of baryons between phases of the interstellar medium (ISM) and stars drives the dynamical and chemical evolution of galaxies. One major inherent challenge lies in understanding how individual star-forming regions (parsec-scale) couple spatially and temporally to entire galaxies on kilo-parsec scales. Recent multiwavelength wide-field, high-resolution observations are beginning to shed light on how the phases of the baryon cycle are structured across star-forming galaxy disks. In particular, I will show that molecular gas tends to sit near virial equilibrium across a range of environments, but that there is no “magic scale” at which structures become gravitationally bound. I will also discuss work refining star formation rate and metallicity calculations in galaxies at the individual HII region scale. Finally, I will present JWST observations and modeling that show that mid-IR emission is (1) a robust tracer of the bulk cold ISM, and (2) able to diagnose detailed dust properties at high resolution in galaxies.

2023-10-20
11:00
Zooming in on the Baryon Cycle in Galaxies
Christopher Faesi (UConn)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
The cycling of baryons between phases of the interstellar medium (ISM) and stars drives the dynamical and chemical evolution of galaxies. One major inherent challenge lies in understanding how individual star-forming regions (parsec-scale) couple spatially and temporally to entire galaxies on kilo-parsec scales. Recent multiwavelength wide-field, high-resolution observations are beginning to shed light on how the phases of the baryon cycle are structured across star-forming galaxy disks. In particular, I will show that molecular gas tends to sit near virial equilibrium across a range of environments, but that there is no “magic scale” at which structures become gravitationally bound. I will also discuss work refining star formation rate and metallicity calculations in galaxies at the individual HII region scale. Finally, I will present JWST observations and modeling that show that mid-IR emission is (1) a robust tracer of the bulk cold ISM, and (2) able to diagnose detailed dust properties at high resolution in galaxies.

2023-10-13
11:00
The Galactic Center black hole with GRAVITY
Felix Widmann (MPE)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The black hole SgrA* at the center of our galaxy offers the unique possibility to probe General Relativity in an unexplored regime and to study the accretion physics around a supermassive black hole. The proximity of SgrA* allows us to directly observe stars orbiting the black hole and measure emission from the accretion flow of the black hole.
With the unprecedented resolution and sensitivity of the interferometric instrument GRAVITY, we push the observations of the Galactic Center to a new level. In this talk, I will summarize the results achieved with GRAVITY so far and highlight the latest developments. I will talk about the search for ever-fainter stars in close orbits around SgrA*, which allow us to measure the effects of General Relativity in the star's orbits. I will also demonstrate how we can use brightness excursions in SgrA*'s accretion flow (so-called flares) to understand the physics around supermassive black holes. The recent addition of polarimetry allows us to combine the astrometric motion of flares with observed swings in the polarization angle to study the magnetic field around SgrA*. Combining these two measurements enables us to understand better the accretion flow and the physics around the supermassive black hole.

2023-10-13
11:00
The Galactic Center black hole with GRAVITY
Felix Widmann (MPE)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
The black hole SgrA* at the center of our galaxy offers the unique possibility to probe General Relativity in an unexplored regime and to study the accretion physics around a supermassive black hole. The proximity of SgrA* allows us to directly observe stars orbiting the black hole and measure emission from the accretion flow of the black hole.
With the unprecedented resolution and sensitivity of the interferometric instrument GRAVITY, we push the observations of the Galactic Center to a new level. In this talk, I will summarize the results achieved with GRAVITY so far and highlight the latest developments. I will talk about the search for ever-fainter stars in close orbits around SgrA*, which allow us to measure the effects of General Relativity in the star's orbits. I will also demonstrate how we can use brightness excursions in SgrA*'s accretion flow (so-called flares) to understand the physics around supermassive black holes. The recent addition of polarimetry allows us to combine the astrometric motion of flares with observed swings in the polarization angle to study the magnetic field around SgrA*. Combining these two measurements enables us to understand better the accretion flow and the physics around the supermassive black hole.

2023-10-13
11:00
TBD
Felix Widmann (MPE)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2023-10-06
11:00
“Elemental" Insights Into Massive Galaxy Formation
Mariska Kriek (Leiden Obs.)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The chemical compositions of massive galaxies offer a unique view into their formation histories. While metals have been extensively studied in galaxies up to z~4, beyond z=0.7, the majority of studies have focused on star-forming galaxies. Measuring metallicities for distant quiescent galaxies is exceptionally challenging, as it relies on detecting faint stellar absorption features, shifted into the near-infrared wavelength regime. However, quiescent galaxies dominate the high-mass end of the galaxy population up to z~2.5, and thus it is crucial to extend their metal studies to earlier epochs as well. In this colloquium, I will present new elemental abundance measurements of massive quiescent galaxies up to z~2.3 and discuss their implications for understanding chemical enrichment, star formation, and assembly histories. I will discuss the emerging picture of massive galaxy growth over the past 11 billion years, based on these new metallicity studies, combined with similar studies at lower redshifts and measurements of other physical properties. Finally, I will present an overview of ongoing programs with the James Webb Space Telescope (JWST), which will further advance our understanding in this field.


MPIA signature speaker @ KoCo

2023-10-06
11:00
TBA
Mariska Kriek
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
TBA


MPIA signature speaker @ KoCo

2023-09-29
11:00
Improving the census of open clusters with Gaia data and machine learning
Emily Hunt (LSW)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Open clusters are one of the most useful places in the universe for studies of stellar and galactic evolution. Formed when stars collapse from the same molecular cloud into a gravitationally bound cluster, open clusters offer a unique way to study stars of a homogeneous age and chemical composition across a range of masses. This property means they are useful objects for many different areas of astronomy, and accurately cataloguing them is hence important. In this talk, I will present the work I conducted during my PhD, aiming to improve a number of aspects of the census of open clusters in the age  of Gaia. After an introduction to the field, I will start by discussing different unsupervised machine learning algorithms for detecting clusters in the billion-star dataset of Gaia. Next, I will present our recently published catalogue of over 7000 clusters, which represents the largest homogeneous unduplicated catalogue of open clusters to date, including cluster classifications and parameters calculated with approximate Bayesian neural networks. Finally, I will discuss upcoming work on better defining open clusters observationally, which will revolutionise how open clusters can be distinguished from unbound moving groups and associations.

2023-09-29
11:00
Improving the census of open clusters with Gaia data and machine learning
Emily Hunt (LSW)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Open clusters are one of the most useful places in the universe for studies of stellar and galactic evolution. Formed when stars collapse from the same molecular cloud into a gravitationally bound cluster, open clusters offer a unique way to study stars of a homogeneous age and chemical composition across a range of masses. This property means they are useful objects for many different areas of astronomy, and accurately cataloguing them is hence important. In this talk, I will present the work I conducted during my PhD, aiming to improve a number of aspects of the census of open clusters in the age  of Gaia. After an introduction to the field, I will start by discussing different unsupervised machine learning algorithms for detecting clusters in the billion-star dataset of Gaia. Next, I will present our recently published catalogue of over 7000 clusters, which represents the largest homogeneous unduplicated catalogue of open clusters to date, including cluster classifications and parameters calculated with approximate Bayesian neural networks. Finally, I will discuss upcoming work on better defining open clusters observationally, which will revolutionise how open clusters can be distinguished from unbound moving groups and associations.

2023-09-22
11:00
ALMA reveals dust in galaxies at high redshift
Rebecca Bowler (Manchester)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
I will present an overview of what is known about dust in high-redshift galaxies and what this can tell us about early star formation and metal enrichment.  The advent of sensitive mm/sub-mm observations from ALMA and other facilities has opened up the field of direct detection of dust and FIR emission lines in normal galaxies for the first time at z > 6.  From the first detections in individual sources (e.g. the well studied A1689-zD1 at z = 7.13) almost a decade ago the field has gained momentum with blind surveys (such as the ALMA UDF) and large programs targeting the more massive and rare sources (such as ALPINE and REBELS) providing a wealth of data to probe the presence of early dust.  Despite programs such as REBELS targeting rest-UV bright galaxies, these results have surprisingly revealed a significant obscured fraction of star-formation within "normal" galaxies (f_obs > 0.5) even beyond z = 7.  In the cases where there is higher resolution ALMA + HST + JWST data available, a diversity of dust morphologies is found,  with some regions in the galaxy being HST and even JWST-dark, highlighting the key importance of direct dust detections with ALMA.   The dust attenuation law (and hence composition) can be probed via scaling relations such as the "Infrared-excess-beta" relation, and I will present recent results from a compilation of 160 galaxies at z = 4-8 from the ALPINE and REBELS surveys.  I will end by discussing the most pressing open questions and challenges: what is the dust temperature, what is the star-dust geometry and how much star-formation in the early universe is obscured/HST-dark?

MPIA signature speaker at KoCo

2023-09-22
11:00
ALMA reveals dust in galaxies at high redshift
Rebecca Bowler (Manchester)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
I will present an overview of what is known about dust in high-redshift galaxies and what this can tell us about early star formation and metal enrichment.  The advent of sensitive mm/sub-mm observations from ALMA and other facilities has opened up the field of direct detection of dust and FIR emission lines in normal galaxies for the first time at z > 6.  From the first detections in individual sources (e.g. the well studied A1689-zD1 at z = 7.13) almost a decade ago the field has gained momentum with blind surveys (such as the ALMA UDF) and large programs targeting the more massive and rare sources (such as ALPINE and REBELS) providing a wealth of data to probe the presence of early dust.  Despite programs such as REBELS targeting rest-UV bright galaxies, these results have surprisingly revealed a significant obscured fraction of star-formation within "normal" galaxies (f_obs > 0.5) even beyond z = 7.  In the cases where there is higher resolution ALMA + HST + JWST data available, a diversity of dust morphologies is found,  with some regions in the galaxy being HST and even JWST-dark, highlighting the key importance of direct dust detections with ALMA.   The dust attenuation law (and hence composition) can be probed via scaling relations such as the "Infrared-excess-beta" relation, and I will present recent results from a compilation of 160 galaxies at z = 4-8 from the ALPINE and REBELS surveys.  I will end by discussing the most pressing open questions and challenges: what is the dust temperature, what is the star-dust geometry and how much star-formation in the early universe is obscured/HST-dark?

MPIA signature speaker at KoCo

2023-09-15
11:00
The Milky Way Laboratory
Cara Battersby (UConn)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Galaxy centers are the hubs of activity that drive galaxy evolution, from supermassive black holes to feedback from dense stellar clusters. While the bulk of our Milky Way Galaxy is a prime example of present epoch “normal” star formation, our galaxy's center has gas properties that are more reminiscent of star formation during its cosmic peak. In our research group, the Milky Way Laboratory, we capitalize on both the “normal” and “extreme” star formation in our own cosmic backyard in order to resolve the interplay of physical processes in detail. In this talk, I will discuss efforts to measure how stars gain their mass and how the star formation process may vary across the Galaxy. In our galaxy's central molecular zone, the process of star formation is complicated by constant gas inflow, high levels of turbulence, and more. I will present both simulations and observations toward this region that aim to understand the role of the gas inflow, the 3-D geometry of the region, properties of the gas, and incipient star formation.

2023-09-15
11:00
TBA
Rebecca Bowler (Manchester)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBA

MPIA signature speaker at KoCo

2023-09-15
11:00
The Milky Way Laboratory
Cara Battersby (UConn)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Galaxy centers are the hubs of activity that drive galaxy evolution, from supermassive black holes to feedback from dense stellar clusters. While the bulk of our Milky Way Galaxy is a prime example of present epoch “normal” star formation, our galaxy's center has gas properties that are more reminiscent of star formation during its cosmic peak. In our research group, the Milky Way Laboratory, we capitalize on both the “normal” and “extreme” star formation in our own cosmic backyard in order to resolve the interplay of physical processes in detail. In this talk, I will discuss efforts to measure how stars gain their mass and how the star formation process may vary across the Galaxy. In our galaxy's central molecular zone, the process of star formation is complicated by constant gas inflow, high levels of turbulence, and more. I will present both simulations and observations toward this region that aim to understand the role of the gas inflow, the 3-D geometry of the region, properties of the gas, and incipient star formation.

2023-09-08
11:00
The Galactic Center: Insights from K-band spectroscopy
Anja Feldmeier-Krause (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract

The Galactic center region has a mass of ~10^9 M_sun. It consists of the nuclear stellar disk (NSD), a flat, rotating stellar structure, and the nuclear star cluster (NSC), the densest concentration of stars in the Galaxy. 

The NSC and NSD are distinct structures of the Milky Way, but also connected to the larger Milky Way structures, e.g. via the inflow and outflow of gas, and the infall of star clusters. Our knowledge of the larger Milky Way structures, Galactic disc, bulge and halo, has expanded in recent years through surveys and dedicated missions. Hidden behind large amounts of interstellar dust, the Galactic centre structures, NSC and NSD, are inaccessible for these surveys, and they miss an important piece for our understanding of the Milky Way's formation and evolution. 

In this talk I will present spectroscopic observations of the Galactic centre, resulting in >\;2,500 stellar spectra. I will show the spatial distribution of young (few Myr old) stars, the metallicity distribution of the older (several Gyr) red giant stars, and spatial variations of the metallicity distribution. 


2023-09-08
11:00
TBA
Rajika Kuruwita (HITS)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBA

2023-09-08
11:00
The Galactic Center: Insights from K-band spectroscopy
Anja Feldmeier-Krause (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract

The Galactic center region has a mass of ~10^9 M_sun. It consists of the nuclear stellar disk (NSD), a flat, rotating stellar structure, and the nuclear star cluster (NSC), the densest concentration of stars in the Galaxy. 

The NSC and NSD are distinct structures of the Milky Way, but also connected to the larger Milky Way structures, e.g. via the inflow and outflow of gas, and the infall of star clusters. Our knowledge of the larger Milky Way structures, Galactic disc, bulge and halo, has expanded in recent years through surveys and dedicated missions. Hidden behind large amounts of interstellar dust, the Galactic centre structures, NSC and NSD, are inaccessible for these surveys, and they miss an important piece for our understanding of the Milky Way's formation and evolution. 

In this talk I will present spectroscopic observations of the Galactic centre, resulting in >\;2,500 stellar spectra. I will show the spatial distribution of young (few Myr old) stars, the metallicity distribution of the older (several Gyr) red giant stars, and spatial variations of the metallicity distribution. 


2023-09-01
11:00
"Direct Imaging and Characterization of Exoplanets with JWST and Beyond"
Sasha Hinkley (Uni of Exeter)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Abstract: Almost all of the extrasolar planets identified to date have only been indirectly detected based on some effect they have on their host star's light.  However, we now have direct images of a number of massive gaseous exoplanets at wide orbital separations.  This collection of directly imaged exoplanets is already providing valuable atmospheric characterization, especially with new observatories such as the James Webb Space Telescope (JWST).  Exoplanet direct imaging with JWST is allowing us to address some of the most fundamental questions in exoplanetary science, such as the degree to which we can link our measurements of the atmospheric compositions of exoplanets with their formation history. JWST is also likely to help us gain a much more complete picture of the overall demographics of exoplanets, especially at wide orbital separations.  I will also discuss how the Gaia mission is already starting to point the way to numerous more such exoplanets suitable for direct imaging.  Characterization of these self-luminous planets will enlighten their earliest thermal histories, still the greatest source of uncertainty for theoretical models of planet formation.  Lastly, I will discuss upcoming observations in the next decades which should have the capability to directly observe and characterize Earth-like planets in the habitable zones of their host stars. 

2023-09-01
11:00
"Direct Imaging and Characterization of Exoplanets with JWST and Beyond"
Sasha Hinkley (Uni of Exeter)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Abstract: Almost all of the extrasolar planets identified to date have only been indirectly detected based on some effect they have on their host star's light.  However, we now have direct images of a number of massive gaseous exoplanets at wide orbital separations.  This collection of directly imaged exoplanets is already providing valuable atmospheric characterization, especially with new observatories such as the James Webb Space Telescope (JWST).  Exoplanet direct imaging with JWST is allowing us to address some of the most fundamental questions in exoplanetary science, such as the degree to which we can link our measurements of the atmospheric compositions of exoplanets with their formation history. JWST is also likely to help us gain a much more complete picture of the overall demographics of exoplanets, especially at wide orbital separations.  I will also discuss how the Gaia mission is already starting to point the way to numerous more such exoplanets suitable for direct imaging.  Characterization of these self-luminous planets will enlighten their earliest thermal histories, still the greatest source of uncertainty for theoretical models of planet formation.  Lastly, I will discuss upcoming observations in the next decades which should have the capability to directly observe and characterize Earth-like planets in the habitable zones of their host stars. 

2023-08-11
11:00
The JWST view on ice and gas during star and planet formation
Giulia Perotti (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2023-08-04
11:00
Magnetic Fields in the Milky Way and the Small Magellanic Cloud
Jackie Ma (ANU)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The magnetic field is a crucial constituent of the interstellar medium, and accurately understanding its strength and structure in galaxies has significant implications for various areas of galactic astrophysics. Recent advancements in sensitivity and frequency coverage of radio telescopes have provided clearer insights into the magnetic fields of our Milky Way Galaxy and its neighbouring Small Magellanic Cloud (SMC). In this talk, I will share the new magnetic knowledge gained from these advanced radio instruments, using both linear polarisation and high-resolution HI measurements. In the case of the Milky Way, I utilised the Faraday rotation experienced by linearly polarised emission from extragalactic radio sources to find that (1) contrary to theoretical expectations, the galactic-scale magnetic field in the Galactic disk can reverse its direction across the mid-plane towards the Sagittarius spiral arm, and (2) the Galactic magnetic structures can undergo significant changes at <~ 10" scales, most likely due to the anisotropic turbulent magnetic fields shaped by compression and shearing. Meanwhile in the SMC, I find that the filamentary HI structures near its centre are preferentially aligned with the magnetic fields traced by starlight polarisation, suggesting that these HI structures can have the potential of being a new 3D tracer of the SMC's plane-of-sky magnetic field. I will conclude by highlighting the exciting prospects in magnetism studies offered by on-going southern sky radio survey, such as the POSSUM survey in polarisation and the GASKAP survey in HI.

2023-08-04
11:00
Magnetic Fields in the Milky Way and the Small Magellanic Cloud
Jackie Ma (ANU)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The magnetic field is a crucial constituent of the interstellar medium, and accurately understanding its strength and structure in galaxies has significant implications for various areas of galactic astrophysics. Recent advancements in sensitivity and frequency coverage of radio telescopes have provided clearer insights into the magnetic fields of our Milky Way Galaxy and its neighbouring Small Magellanic Cloud (SMC). In this talk, I will share the new magnetic knowledge gained from these advanced radio instruments, using both linear polarisation and high-resolution HI measurements. In the case of the Milky Way, I utilised the Faraday rotation experienced by linearly polarised emission from extragalactic radio sources to find that (1) contrary to theoretical expectations, the galactic-scale magnetic field in the Galactic disk can reverse its direction across the mid-plane towards the Sagittarius spiral arm, and (2) the Galactic magnetic structures can undergo significant changes at <~ 10" scales, most likely due to the anisotropic turbulent magnetic fields shaped by compression and shearing. Meanwhile in the SMC, I find that the filamentary HI structures near its centre are preferentially aligned with the magnetic fields traced by starlight polarisation, suggesting that these HI structures can have the potential of being a new 3D tracer of the SMC's plane-of-sky magnetic field. I will conclude by highlighting the exciting prospects in magnetism studies offered by on-going southern sky radio survey, such as the POSSUM survey in polarisation and the GASKAP survey in HI.

2023-07-28
11:00
Radiative modeling of extended relativistic jets
Michael Zacharias (LSW)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract

Blazars are those kinds of active galactic nuclei, where the relativistic jet points towards Earth. Due to relativistic beaming, the processes inside the jet can be studied in great detail. Kinetic radiation codes provide an excellent opportunity to obtain the particle distributions and to describe interaction processes within the jet, as well as to model the radiative output of the jet. Here, I will present the code "ExHaLe-jet" that describes extended jets considering both leptonic and hadronic processes. I will highlight the influence of thermal photon sources external to the jet, which are prime targets for particle-photon interactions inside the jet.
In a second part of the talk, I will discuss a recent observational result, where a blazar jet seems to suddenly, partially switch off. 


2023-07-28
11:00
Radiative modeling of extended relativistic jets
Michael Zacharias (LSW)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract

Blazars are those kinds of active galactic nuclei, where the relativistic jet points towards Earth. Due to relativistic beaming, the processes inside the jet can be studied in great detail. Kinetic radiation codes provide an excellent opportunity to obtain the particle distributions and to describe interaction processes within the jet, as well as to model the radiative output of the jet. Here, I will present the code "ExHaLe-jet" that describes extended jets considering both leptonic and hadronic processes. I will highlight the influence of thermal photon sources external to the jet, which are prime targets for particle-photon interactions inside the jet.
In a second part of the talk, I will discuss a recent observational result, where a blazar jet seems to suddenly, partially switch off. 


2023-07-21
11:00
First Stars: Formation, Properties, and Impact
Ralf Klessen (ITA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The first generation of stars, often called Population III (or Pop III), form from metal-free primordial gas at redshifts z ~ 30 and below. They dominate the cosmic star formation history until z ~ 20-15, at which point the formation of metal-enriched Pop II stars takes over. I review current theoretical models for the formation, properties and impact of Pop III stars, and discuss observational constraints. I argue that primordial gas is highly susceptible to fragmentation and Pop III stars form as members of small clusters with a logarithmically flat mass function. Feedback from massive Pop III stars plays a central role in regulating subsequent star formation, but major uncertainties remain regarding its immediate impact. Direct observations of Pop III stars in the early Universe remain extremely challenging, whereas stellar archeological surveys allow us to constrain both the low-mass and the high-mass ends of the Pop III mass distribution. Observations suggest that most massive Pop III stars end their lives as core-collapse supernovae rather than as pair-instability supernovae.

2023-07-21
11:00
First Stars: Formation, Properties, and Impact
Ralf Klessen (ITA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The first generation of stars, often called Population III (or Pop III), form from metal-free primordial gas at redshifts z ~ 30 and below. They dominate the cosmic star formation history until z ~ 20-15, at which point the formation of metal-enriched Pop II stars takes over. I review current theoretical models for the formation, properties and impact of Pop III stars, and discuss observational constraints. I argue that primordial gas is highly susceptible to fragmentation and Pop III stars form as members of small clusters with a logarithmically flat mass function. Feedback from massive Pop III stars plays a central role in regulating subsequent star formation, but major uncertainties remain regarding its immediate impact. Direct observations of Pop III stars in the early Universe remain extremely challenging, whereas stellar archeological surveys allow us to constrain both the low-mass and the high-mass ends of the Pop III mass distribution. Observations suggest that most massive Pop III stars end their lives as core-collapse supernovae rather than as pair-instability supernovae.

2023-07-14
11:00
Robustly Characterizing Exoplanets in a New Era of High-Precision Transit Measurements
Julian De Wit (MIT)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract

With a new-generation of great observatories coming online this decade, unprecedented insights into exoplanets will soon be within reach. Observatories such as the James Webb Space Telescope (JWST) notably enable the study of atmospheres around terrestrial exoplanets and can reveal tri-dimensional structures in the atmospheres of their larger counterparts. Robustly leveraging new observations to reach such achievements will however require extra care as the models currently used may not be up to par with their precision. 

During this presentation, I will introduce work done by MIT's Disruptive Planets group and collaborators towards supporting the robust in-depth characterization of exoplanets. I will specifically discuss how not accounting for the true shape of a planet can lead to a misinterpretation of its interior properties as well as atmospheric structure\; how the current state of our understanding of light-matter interactions can similarly affect our interpretation of planetary spectra and thus inferences regarding their atmospheric properties\; and how the current state of emission spectrum models for stars may even prevent from disentangling between the contribution of a planet and its host star, to start with.  I will also present possible ways to address these challenges. I will end with a step-by-step roadmap to the robust characterization of temperate terrestrial planets with JWST, which includes habitability assessment


2023-07-14
11:00
Robustly Characterizing Exoplanets in a New Era of High-Precision Transit Measurements
Julian De Wit (MIT)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract

With a new-generation of great observatories coming online this decade, unprecedented insights into exoplanets will soon be within reach. Observatories such as the James Webb Space Telescope (JWST) notably enable the study of atmospheres around terrestrial exoplanets and can reveal tri-dimensional structures in the atmospheres of their larger counterparts. Robustly leveraging new observations to reach such achievements will however require extra care as the models currently used may not be up to par with their precision. 

During this presentation, I will introduce work done by MIT's Disruptive Planets group and collaborators towards supporting the robust in-depth characterization of exoplanets. I will specifically discuss how not accounting for the true shape of a planet can lead to a misinterpretation of its interior properties as well as atmospheric structure\; how the current state of our understanding of light-matter interactions can similarly affect our interpretation of planetary spectra and thus inferences regarding their atmospheric properties\; and how the current state of emission spectrum models for stars may even prevent from disentangling between the contribution of a planet and its host star, to start with.  I will also present possible ways to address these challenges. I will end with a step-by-step roadmap to the robust characterization of temperate terrestrial planets with JWST, which includes habitability assessment


2023-07-07
11:00
Paradigm Shifts in Galaxy Formation and Cosmic Rays (and Quasar Fueling)
Philip Hopkins (Caltech)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Simulations of galaxy formation and evolution have led to a number of new insights and paradigm shifts in the last decade. A first is that the “clustering” of star formation in both space and time (aka “bursty” star formation) qualitatively changes the dynamics of star formation itself, stellar “feedback” from radiation and supernovae, and therefore galaxy structure and formation, and even the dark matter structure of galaxies. There is now growing agreement that galaxies pass through some bursty, turbulent, disordered phase before (if they are massive enough) “settling down” to form disks with calmer star formation. I'll review how and why this process occurs, and how we can identify the most important physics at play. A second paradigm shift has come with modeling of cosmic rays. I'll review how there has been a sea change in our understanding both of how these particles could influence the formation of galaxies and stars, and how they actually move through and interact with the interstellar medium on astrophysical “micro-scales,” raising much more fundamental un-solved space plasma physics questions. Finally, on quasars, I'll (very briefly) advertise the first numerical simulations which can self-consistently resolve scales from the intergalactic medium down to the formation of accretion disks powering the most luminous sources in the Universe.

2023-07-07
11:00
Paradigm Shifts in Galaxy Formation and Cosmic Rays (and Quasar Fueling)
Philip Hopkins (Caltech)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Simulations of galaxy formation and evolution have led to a number of new insights and paradigm shifts in the last decade. A first is that the “clustering” of star formation in both space and time (aka “bursty” star formation) qualitatively changes the dynamics of star formation itself, stellar “feedback” from radiation and supernovae, and therefore galaxy structure and formation, and even the dark matter structure of galaxies. There is now growing agreement that galaxies pass through some bursty, turbulent, disordered phase before (if they are massive enough) “settling down” to form disks with calmer star formation. I'll review how and why this process occurs, and how we can identify the most important physics at play. A second paradigm shift has come with modeling of cosmic rays. I'll review how there has been a sea change in our understanding both of how these particles could influence the formation of galaxies and stars, and how they actually move through and interact with the interstellar medium on astrophysical “micro-scales,” raising much more fundamental un-solved space plasma physics questions. Finally, on quasars, I'll (very briefly) advertise the first numerical simulations which can self-consistently resolve scales from the intergalactic medium down to the formation of accretion disks powering the most luminous sources in the Universe.

2023-06-30
11:00
Predictions for the faint Lyman-alpha cosmic web
Chris Byrohl (ZAH/ITA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Neutral hydrogen in the filaments of the cosmic web may be observable through emission of the Lyman-alpha line. Although luminous Lyman-alpha emitters are already an established tracer of the matter distribution in the high-redshift universe, the implications of the faint Lyman-alpha glow within the cosmic web, away from luminous emitters, are yet to be explored. In this talk, I will discuss the nature of large-scale, diffuse Lyman-alpha filaments and their detectability with recent integral field spectrographs such as VLT-MUSE, K-CWI, and HET-VIRUS. To explore this, we combine recent cosmological magnetohydrodynamical galaxy formation simulations with explicit calculation of the Lyman-alpha radiative transfer. We find that observable filaments are illuminated by Lyman-alpha photons that are emitted from the circumgalactic medium of intermediate-mass halos, rather than from the filaments themselves. These photons then escape and scatter within their surrounding, substantially boosting the Lyman-alpha signal from diffuse filaments. Our work provides a reference model for Lyman-alpha filaments, and demonstrates the importance and complexities of Lyman-alpha radiative transfer across spatial scales.

2023-06-30
11:00
Predictions for the faint Lyman-alpha cosmic web
Chris Byrohl (ZAH/ITA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Neutral hydrogen in the filaments of the cosmic web may be observable through emission of the Lyman-alpha line. Although luminous Lyman-alpha emitters are already an established tracer of the matter distribution in the high-redshift universe, the implications of the faint Lyman-alpha glow within the cosmic web, away from luminous emitters, are yet to be explored. In this talk, I will discuss the nature of large-scale, diffuse Lyman-alpha filaments and their detectability with recent integral field spectrographs such as VLT-MUSE, K-CWI, and HET-VIRUS. To explore this, we combine recent cosmological magnetohydrodynamical galaxy formation simulations with explicit calculation of the Lyman-alpha radiative transfer. We find that observable filaments are illuminated by Lyman-alpha photons that are emitted from the circumgalactic medium of intermediate-mass halos, rather than from the filaments themselves. These photons then escape and scatter within their surrounding, substantially boosting the Lyman-alpha signal from diffuse filaments. Our work provides a reference model for Lyman-alpha filaments, and demonstrates the importance and complexities of Lyman-alpha radiative transfer across spatial scales.

2023-06-30
11:00
Predictions for the faint Lyman-alpha cosmic web
Chris Byrohl (ZAH/ITA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Neutral hydrogen in the filaments of the cosmic web may be observable through emission of the Lyman-alpha line. Although luminous Lyman-alpha emitters are already an established tracer of the matter distribution in the high-redshift universe, the implications of the faint Lyman-alpha glow within the cosmic web, away from luminous emitters, are yet to be explored. In this talk, I will discuss the nature of large-scale, diffuse Lyman-alpha filaments and their detectability with recent integral field spectrographs such as VLT-MUSE, K-CWI, and HET-VIRUS. To explore this, we combine recent cosmological magnetohydrodynamical galaxy formation simulations with explicit calculation of the Lyman-alpha radiative transfer. We find that observable filaments are illuminated by Lyman-alpha photons that are emitted from the circumgalactic medium of intermediate-mass halos, rather than from the filaments themselves. These photons then escape and scatter within their surrounding, substantially boosting the Lyman-alpha signal from diffuse filaments. Our work provides a reference model for Lyman-alpha filaments, and demonstrates the importance and complexities of Lyman-alpha radiative transfer across spatial scales.

2023-06-23
11:00
Ultra-Diffuse Galaxies (UDGs) and the Stellar Mass – Halo Mass Relationship
Jonah Gannon (Swinburne University)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The stellar mass – halo mass relationship is a fundamental scaling relationship connecting galaxies from dwarfs to giants to their dark matter halos. This relationship is currently key to our understanding of the complex interplay between the many modes of feedback (e.g., stellar winds, supernovae, AGN) and star formation in galaxies. However, recently a population of large half-light radius, low surface brightness ultra-diffuse galaxies (UDGs) have questioned our understanding of galaxy formation in the dwarf galaxy regime. UDGs have been found to reside in dark matter halos of widely varying mass. While many likely reside in “normal” dark matter halos for their stellar mass, some may exhibit an extreme lack of dark matter while yet others are extremely dark matter rich. In this talk, I give an overview of the current observational evidence for UDGs residing in massive dark matter halos. I place particular emphasis on my own Keck observations which have provided support for UDGs' unexpected stellar mass – halo mass positioning and that has revealed the internal structure of their halo (i.e., core vs cusp nature). I discuss how these observations currently inform proposed formation scenarios for UDGsand show an outstanding tension of my observations with simulations of galaxy formation. I conclude with a brief discussion of the important future goals of the field.

2023-06-23
11:00
TBD
Jonah Gannon (Swinburne University)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2023-06-23
11:00
Ultra-Diffuse Galaxies (UDGs) and the Stellar Mass – Halo Mass Relationship
Jonah Gannon (Swinburne University)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
The stellar mass – halo mass relationship is a fundamental scaling relationship connecting galaxies from dwarfs to giants to their dark matter halos. This relationship is currently key to our understanding of the complex interplay between the many modes of feedback (e.g., stellar winds, supernovae, AGN) and star formation in galaxies. However, recently a population of large half-light radius, low surface brightness ultra-diffuse galaxies (UDGs) have questioned our understanding of galaxy formation in the dwarf galaxy regime. UDGs have been found to reside in dark matter halos of widely varying mass. While many likely reside in “normal” dark matter halos for their stellar mass, some may exhibit an extreme lack of dark matter while yet others are extremely dark matter rich. In this talk, I give an overview of the current observational evidence for UDGs residing in massive dark matter halos. I place particular emphasis on my own Keck observations which have provided support for UDGs' unexpected stellar mass – halo mass positioning and that has revealed the internal structure of their halo (i.e., core vs cusp nature). I discuss how these observations currently inform proposed formation scenarios for UDGsand show an outstanding tension of my observations with simulations of galaxy formation. I conclude with a brief discussion of the important future goals of the field.

2023-06-16
11:00
Star formation and stellar populations in galactic bars
Justus Neumann (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
After a vigorous formation phase driven by mergers and galaxy interactions at early epochs, the evolution of galaxies has been dominated by relatively slow, so-called secular evolution over at least half of the Universe's lifetime. While a large number of today's characteristics of galaxies are generated during this phase, we still lack a solid understanding of the astro-physical processes at play. In this talk, I will present some of my work studying galaxy bars - the main drivers of internal galaxy evolution.

Bars as non-axisymmetric structures have been shown to greatly impact the distribution of stars, gas and angular momentum in galaxies. By studying stellar populations as archaeological relics in the central parts of barred galaxies we are able to learn about processes during bar formation and bar evolution. Furthermore, when looking at current and ongoing star formation, we find that about half of all nearby barred galaxies show signatures of star formation along the bar, while the other half presents itself with a curious absence of star formation. Despite the presence of cold molecular gas observed as radial flows along the edge of the bar towards the galaxy centre, the local environment seems to be able to suppress star formation. By using integral field spectrographs such as VLT/MUSE and eBOSS/MaNGA, I will present what we can learn from studies of star formation and stellar populations in galactic bars.

2023-06-16
11:00
TBD
Justus Neumann (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2023-06-16
11:00
Star formation and stellar populations in galactic bars
Justus Neumann (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
After a vigorous formation phase driven by mergers and galaxy interactions at early epochs, the evolution of galaxies has been dominated by relatively slow, so-called secular evolution over at least half of the Universe's lifetime. While a large number of today's characteristics of galaxies are generated during this phase, we still lack a solid understanding of the astro-physical processes at play. In this talk, I will present some of my work studying galaxy bars - the main drivers of internal galaxy evolution.

Bars as non-axisymmetric structures have been shown to greatly impact the distribution of stars, gas and angular momentum in galaxies. By studying stellar populations as archaeological relics in the central parts of barred galaxies we are able to learn about processes during bar formation and bar evolution. Furthermore, when looking at current and ongoing star formation, we find that about half of all nearby barred galaxies show signatures of star formation along the bar, while the other half presents itself with a curious absence of star formation. Despite the presence of cold molecular gas observed as radial flows along the edge of the bar towards the galaxy centre, the local environment seems to be able to suppress star formation. By using integral field spectrographs such as VLT/MUSE and eBOSS/MaNGA, I will present what we can learn from studies of star formation and stellar populations in galactic bars.

2023-06-09
11:00
Trace gases and weather: exoplanet atmospheres 
with JWST and the ELTs

Paul Molliere (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
With the recent launch of JWST, and with the ELT seeing first light towards the end of this decade, the exoplanet atmosphere community is in for an exciting ride. In this talk I will focus on two aspects of science enabled by these observatories. The first is tracing rare atmospheric absorbers, which have never been detected before. These allow us to constrain planet formation from a new angle, going beyond the often-mentioned carbon-to-oxygen number ratio. In addition, some of these detections allow us to probe atmospheric chemistry in disequilibrium, which had been a mostly theoretical exercise before JWST. As a part of this I will give a sneak peek of the results we obtain in the JWST MIRI GTO program. The second aspect is atmospheric weather: what can we learn about atmospheric variability and wind patterns with this new generation of observatories? I will discuss the observations that JWST is going to take in the near future, and what we can expect once the ELT comes online, revealing individual absorption lines in the atmospheres of extrasolar planets.

2023-06-09
11:00
TBD
Paul Molliere (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2023-06-09
11:00
Trace gases and weather: exoplanet atmospheres 
with JWST and the ELTs

Paul Molliere (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
With the recent launch of JWST, and with the ELT seeing first light towards the end of this decade, the exoplanet atmosphere community is in for an exciting ride. In this talk I will focus on two aspects of science enabled by these observatories. The first is tracing rare atmospheric absorbers, which have never been detected before. These allow us to constrain planet formation from a new angle, going beyond the often-mentioned carbon-to-oxygen number ratio. In addition, some of these detections allow us to probe atmospheric chemistry in disequilibrium, which had been a mostly theoretical exercise before JWST. As a part of this I will give a sneak peek of the results we obtain in the JWST MIRI GTO program. The second aspect is atmospheric weather: what can we learn about atmospheric variability and wind patterns with this new generation of observatories? I will discuss the observations that JWST is going to take in the near future, and what we can expect once the ELT comes online, revealing individual absorption lines in the atmospheres of extrasolar planets.

2023-06-02
11:00
TBD
José Eduardo Méndez Delgado (ARI)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2023-06-02
11:00
Temperature inhomogeneities cause the abundance discrepancy in H II regions
José Eduardo Méndez Delgado (ARI)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
H II regions, ionized nebulae associated to massive star formation, exhibit a wealth of emission lines that are the fundamental basis for estimating the chemical composition of the Universe. Heavy element abundances are particularly important because they regulate the cooling of the interstellar gas and are essential to the understanding of several phenomena such as nucleosynthesis, star formation and chemical evolution. For more than 80 years, however, a discrepancy of a factor of around two between heavy-element abundances derived with collisional excited lines (CELs) and recombination lines (RLs) has thrown our absolute abundance determinations into doubt.  The widely observed CELs are ~10,000 times brighter than RLs but exponentially dependent on temperature. Which of the lines (if any) gives the correct heavy-element abundances?
In this colloquium, I will talk about the solution we found for this problem, recently published in Nature. The best available deep optical spectra of star forming regions show evidence of the presence of temperature inhomogeneities within the gas. These inhomogeneities are concentrated in the highly ionized gas and cause the abundance discrepancy problem. This work implies that most metallicity determinations, those based on CELs, must be revised as they may be severely underestimated. The evidence indicates that this effect could be greater in regions of lower metallicity, such as the JWST high-z galaxies. Fortunately, since the temperature inhomogeneities are concentrated in the highly ionized areas of the nebulae, it is possible to correctly determine metallicities using CELs, following the proposed empirical relations.

2023-06-02
11:00
Temperature inhomogeneities cause the abundance discrepancy in H II regions
José Eduardo Méndez Delgado (ARI)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
H II regions, ionized nebulae associated to massive star formation, exhibit a wealth of emission lines that are the fundamental basis for estimating the chemical composition of the Universe. Heavy element abundances are particularly important because they regulate the cooling of the interstellar gas and are essential to the understanding of several phenomena such as nucleosynthesis, star formation and chemical evolution. For more than 80 years, however, a discrepancy of a factor of around two between heavy-element abundances derived with collisional excited lines (CELs) and recombination lines (RLs) has thrown our absolute abundance determinations into doubt.  The widely observed CELs are ~10,000 times brighter than RLs but exponentially dependent on temperature. Which of the lines (if any) gives the correct heavy-element abundances?
In this colloquium, I will talk about the solution we found for this problem, recently published in Nature. The best available deep optical spectra of star forming regions show evidence of the presence of temperature inhomogeneities within the gas. These inhomogeneities are concentrated in the highly ionized gas and cause the abundance discrepancy problem. This work implies that most metallicity determinations, those based on CELs, must be revised as they may be severely underestimated. The evidence indicates that this effect could be greater in regions of lower metallicity, such as the JWST high-z galaxies. Fortunately, since the temperature inhomogeneities are concentrated in the highly ionized areas of the nebulae, it is possible to correctly determine metallicities using CELs, following the proposed empirical relations.

2023-05-26
11:00
The JWST view on ice and gas
Giulia Perotti (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The interaction between interstellar dust, ice and gas plays a major role for the chemistry in regions where star and planets form. Different reactions occur in the gas and on the ice mantles of dust grains in these regions, and consequently the mutual exchange of matter between the two phases is what regulates the physical and chemical evolution of newborn stars and planets. In this talk, I will introduce recent discoveries using JWST that are advancing our understanding of this complex interplay. I will show first JWST observations of the PDS 70 planet-forming disk as part of the MIRI mid-INfrared Disk Survey (MINDS, PI: Th. Henning). The much higher sensitivity of MIRI-MRS compared with previous Spitzer data reveals emission of water vapour. This demonstrates that the terrestrial planet-forming zone of PDS 70 has maintained to some degree the physical and chemical conditions of young disks, in spite of the ~65 AU planet-induced gap.

2023-05-26
11:00
The JWST view on ice and gas during star and planet formation
Giulia Perotti (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2023-05-12
11:00
TBD
Michael Küffmeier (MPE)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2023-05-12
11:00
Modeling constraints on the mass reservoirs of forming disks
Michael Küffmeier (MPE)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The traditional paradigm of star and planet formation can be summarized as follows: stars form with circumstellar disks due to the collapse of rotating dense gas and dust. Such disks are of existential importance as they are the birthplaces of planets. The colloquium will provide an overview of developments and challenges in modeling the formation of these disks that are often referred to as protoplanetary or planet-forming disks. First, I will summarize how various problems related to disk formation arose and were subsequently solved by incorporating various physical effects in spherical core collapse models during the last two decades. I will particularly focus on the effects of magnetic fields and the role of the ionization rate during the collapse phase. The latter is potentially more important for the diversity of disk sizes in various star-forming environments than currently recognized. Recent observations of so-called streamers that seem to feed the forming disk with fresh material are another sign that the protostellar environment plays a bigger role for disk and ultimately planet formation than we previously believed. In line with the picture of variable accretion, disks can be fed with fresh material at later stages or may even be entirely rejuvenated. Finally, I will highlight key implications of an onset of planet formation while disk formation is ongoing.

2023-05-12
11:00
Modeling constraints on the mass reservoirs of forming disks
Michael Küffmeier (MPE)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The traditional paradigm of star and planet formation can be summarized as follows: stars form with circumstellar disks due to the collapse of rotating dense gas and dust. Such disks are of existential importance as they are the birthplaces of planets. The colloquium will provide an overview of developments and challenges in modeling the formation of these disks that are often referred to as protoplanetary or planet-forming disks. First, I will summarize how various problems related to disk formation arose and were subsequently solved by incorporating various physical effects in spherical core collapse models during the last two decades. I will particularly focus on the effects of magnetic fields and the role of the ionization rate during the collapse phase. The latter is potentially more important for the diversity of disk sizes in various star-forming environments than currently recognized. Recent observations of so-called streamers that seem to feed the forming disk with fresh material are another sign that the protostellar environment plays a bigger role for disk and ultimately planet formation than we previously believed. In line with the picture of variable accretion, disks can be fed with fresh material at later stages or may even be entirely rejuvenated. Finally, I will highlight key implications of an onset of planet formation while disk formation is ongoing.

2023-05-05
11:00
Non-ideal MHD simulations of astrophysical jets with the PLUTO code
Giancarlo Mattia (Arcetri)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Astrophysical jets, consisting of collimated high-speed outflows, are typically found in several sources, e.g., young stellar objects, X-ray binaries, gamma-ray bursts, or active galactic nuclei. The formation of collimated outflows requires some common features, such as the presence of a central object, an accretion disk and a large scale magnetic field (whose origin is still unclear). At first I will discuss dynamo processes within thin accretion disks, able to amplify the magnetic field up to the point where the launching becomes possible, focusing on how to build a more consistent dynamo and diffusivity model. Then I will discuss the first numerical simulations of resistive relativistic jets and the role of magnetic reconnection in the large-scale simulations, which may be responsible for particles acceleration in astrophysical outflows.

2023-05-05
11:00
Non-ideal MHD simulations of astrophysical jets with the PLUTO code
Giancarlo Mattia (Arcetri)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Astrophysical jets, consisting of collimated high-speed outflows, are typically found in several sources, e.g., young stellar objects, X-ray binaries, gamma-ray bursts, or active galactic nuclei. The formation of collimated outflows requires some common features, such as the presence of a central object, an accretion disk and a large scale magnetic field (whose origin is still unclear). At first I will discuss dynamo processes within thin accretion disks, able to amplify the magnetic field up to the point where the launching becomes possible, focusing on how to build a more consistent dynamo and diffusivity model. Then I will discuss the first numerical simulations of resistive relativistic jets and the role of magnetic reconnection in the large-scale simulations, which may be responsible for particles acceleration in astrophysical outflows.

2023-05-05
11:00
Non-ideal MHD simulations of astrophysical jets with the PLUTO code
Giancarlo Mattia (Arcetri)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Astrophysical jets, consisting of collimated high-speed outflows, are typically found in several sources, e.g., young stellar objects, X-ray binaries, gamma-ray bursts, or active galactic nuclei. The formation of collimated outflows requires some common features, such as the presence of a central object, an accretion disk and a large scale magnetic field (whose origin is still unclear). At first I will discuss dynamo processes within thin accretion disks, able to amplify the magnetic field up to the point where the launching becomes possible, focusing on how to build a more consistent dynamo and diffusivity model. Then I will discuss the first numerical simulations of resistive relativistic jets and the role of magnetic reconnection in the large-scale simulations, which may be responsible for particles acceleration in astrophysical outflows.

2023-04-21
11:00
LYRA: Pioneering the realm of ultra-high resolution galaxy formation simulations
Thales Gutcke (Uni of Hawaii)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
One of the greatest uncertainties in current cosmological simulations is the effects of baryonic feedback, since current effective models lack predictability. I will introduce LYRA, a novel cosmological galaxy formation model using moving mesh hydrodynamics that resolves every single supernova and the resulting outflows from first principles. To accomplish this, the simulation is run at ultra-high resolution, includes a multi-phase interstellar medium, individual stars, resolved supernova cooling radii and inhomogeneous metal seeding by Population III stars. The model is run to z=0 on a set of field dwarf galaxies that match the stellar mass, size, stellar kinematics and metallicity relations of Local Group dwarf spheroidals. I proceed to describe the star formation histories, the high redshift assembly, the enriched outflows that contribute to the metal pollution of the intergalactic medium and the present-day globular cluster-like substructure. I show that ultra-high resolution simulations go beyond merely providing more spatial information on smaller scales. Instead, penetrating this regime unfolds access to an emergent set of small-scale constraints on galaxy formation.

2023-04-21
11:00
LYRA: Pioneering the realm of ultra-high resolution galaxy formation simulations
Thales Gutcke (Uni of Hawaii)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
One of the greatest uncertainties in current cosmological simulations is the effects of baryonic feedback, since current effective models lack predictability. I will introduce LYRA, a novel cosmological galaxy formation model using moving mesh hydrodynamics that resolves every single supernova and the resulting outflows from first principles. To accomplish this, the simulation is run at ultra-high resolution, includes a multi-phase interstellar medium, individual stars, resolved supernova cooling radii and inhomogeneous metal seeding by Population III stars. The model is run to z=0 on a set of field dwarf galaxies that match the stellar mass, size, stellar kinematics and metallicity relations of Local Group dwarf spheroidals. I proceed to describe the star formation histories, the high redshift assembly, the enriched outflows that contribute to the metal pollution of the intergalactic medium and the present-day globular cluster-like substructure. I show that ultra-high resolution simulations go beyond merely providing more spatial information on smaller scales. Instead, penetrating this regime unfolds access to an emergent set of small-scale constraints on galaxy formation.

2023-04-21
11:00
LYRA: Pioneering the realm of ultra-high resolution galaxy formation simulations
Thales Gutcke (Uni of Hawaii)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
One of the greatest uncertainties in current cosmological simulations is the effects of baryonic feedback, since current effective models lack predictability. I will introduce LYRA, a novel cosmological galaxy formation model using moving mesh hydrodynamics that resolves every single supernova and the resulting outflows from first principles. To accomplish this, the simulation is run at ultra-high resolution, includes a multi-phase interstellar medium, individual stars, resolved supernova cooling radii and inhomogeneous metal seeding by Population III stars. The model is run to z=0 on a set of field dwarf galaxies that match the stellar mass, size, stellar kinematics and metallicity relations of Local Group dwarf spheroidals. I proceed to describe the star formation histories, the high redshift assembly, the enriched outflows that contribute to the metal pollution of the intergalactic medium and the present-day globular cluster-like substructure. I show that ultra-high resolution simulations go beyond merely providing more spatial information on smaller scales. Instead, penetrating this regime unfolds access to an emergent set of small-scale constraints on galaxy formation.

2023-04-14
11:00
Andromeda as a Stepping Stone to the Local Volume: Resolved Stellar Chemodynamics of Extragalactic Streams, Shells, and Disks
Ivanna Escala (Princeton U.)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The formation histories of massive disk galaxies are key to understanding galactic hierarchical assembly and matter distributions. Within the Local Group, Andromeda (M31) provides a unique opportunity for detailed reconstructions of galaxy formation history, where its active merger history sets it apart from the Milky Way (MW). Two primary outstanding questions remain concerning M31's assembly history:  has its disk survived a major merger within the last few billion years, and does this major merger coincide with the formation of M31's Giant Stellar Stream (GSS) and its various tidal shells? In this talk, I will present results from the Elemental Abundances in M31 and Spectroscopic and Photometric Landscape of Andromeda's Stellar Halo (SPLASH) surveys on resolved stellar chemodynamics in M31's disk region and GSS-related tidal substructure. I will discuss implications for the formation of M31's disk and inner stellar halo and constraints on the nature of M31's last significant merger.  I will conclude by highlighting the utility of modern spectroscopic studies of resolved stellar populations in M31 for connecting our MW-based understanding of galaxy formation to future observations of disk galaxies in the Local Volume.

2023-04-14
11:00
Andromeda as a Stepping Stone to the Local Volume: Resolved Stellar Chemodynamics of Extragalactic Streams, Shells, and Disks
Ivanna Escala (Princeton U.)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The formation histories of massive disk galaxies are key to understanding galactic hierarchical assembly and matter distributions. Within the Local Group, Andromeda (M31) provides a unique opportunity for detailed reconstructions of galaxy formation history, where its active merger history sets it apart from the Milky Way (MW). Two primary outstanding questions remain concerning M31's assembly history:  has its disk survived a major merger within the last few billion years, and does this major merger coincide with the formation of M31's Giant Stellar Stream (GSS) and its various tidal shells? In this talk, I will present results from the Elemental Abundances in M31 and Spectroscopic and Photometric Landscape of Andromeda's Stellar Halo (SPLASH) surveys on resolved stellar chemodynamics in M31's disk region and GSS-related tidal substructure. I will discuss implications for the formation of M31's disk and inner stellar halo and constraints on the nature of M31's last significant merger.  I will conclude by highlighting the utility of modern spectroscopic studies of resolved stellar populations in M31 for connecting our MW-based understanding of galaxy formation to future observations of disk galaxies in the Local Volume.

2023-04-14
11:00
Andromeda as a Stepping Stone to the Local Volume: Resolved Stellar Chemodynamics of Extragalactic Streams, Shells, and Disks
Ivanna Escala (Princeton U.)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The formation histories of massive disk galaxies are key to understanding galactic hierarchical assembly and matter distributions. Within the Local Group, Andromeda (M31) provides a unique opportunity for detailed reconstructions of galaxy formation history, where its active merger history sets it apart from the Milky Way (MW). Two primary outstanding questions remain concerning M31's assembly history:  has its disk survived a major merger within the last few billion years, and does this major merger coincide with the formation of M31's Giant Stellar Stream (GSS) and its various tidal shells? In this talk, I will present results from the Elemental Abundances in M31 and Spectroscopic and Photometric Landscape of Andromeda's Stellar Halo (SPLASH) surveys on resolved stellar chemodynamics in M31's disk region and GSS-related tidal substructure. I will discuss implications for the formation of M31's disk and inner stellar halo and constraints on the nature of M31's last significant merger.  I will conclude by highlighting the utility of modern spectroscopic studies of resolved stellar populations in M31 for connecting our MW-based understanding of galaxy formation to future observations of disk galaxies in the Local Volume.

2023-03-31
11:00
TBA
Ivanna Escala (Princeton U.)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBA

2023-03-24
11:00
Predictions for the faint Lyman-alpha cosmic web
Chris Byrohl (ZAH/ITA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Neutral hydrogen in the filaments of the cosmic web may be observable through emission of the Lyman-alpha line. Although luminous Lyman-alpha emitters are already an established tracer of the matter distribution in the high-redshift universe, the implications of the faint Lyman-alpha glow within the cosmic web, away from luminous emitters, are yet to be explored. In this talk, I will discuss the nature of large-scale, diffuse Lyman-alpha filaments and their detectability with recent integral field spectrographs such as VLT-MUSE, K-CWI, and HET-VIRUS. To explore this, we combine recent cosmological magnetohydrodynamical galaxy formation simulations with explicit calculation of the Lyman-alpha radiative transfer. We find that observable filaments are illuminated by Lyman-alpha photons that are emitted from the circumgalactic medium of intermediate-mass halos, rather than from the filaments themselves. These photons then escape and scatter within their surrounding, substantially boosting the Lyman-alpha signal from diffuse filaments. Our work provides a reference model for Lyman-alpha filaments, and demonstrates the importance and complexities of Lyman-alpha radiative transfer across spatial scales.

2023-03-17
11:00
Rapid accretion of rocky planets and the outgassing of their first atmospheres
Anders Johansen (The Globe Institute)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Terrestrial planets have traditionally been thought to form by collisions between protoplanets taking place mostly after the dissipation of the protoplanetary disc, on time-scales of 30-100 million years. I present here a new theoretical model where terrestrial planets grow instead by accreting small pebbles in the protoplanetary disc within 3-5 million years. I discuss how the immense pebble accretion heat leads to extensive melting of the growing planets and to the emergence of deep magma oceans. Volatiles such as water, carbon and nitrogen are accreted with the pebbles and partitioned between atmosphere, magma ocean and core. The end of the accretion phase leads to rapid crystallisation of the magma ocean and outgassing of the first atmosphere. I will show how the atmospheric composition of young planets is key to understanding the origin of life.

2023-03-17
11:00
Rapid accretion of rocky planets and the outgassing of their first atmospheres
Anders Johansen (The Globe Institute)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Terrestrial planets have traditionally been thought to form by collisions between protoplanets taking place mostly after the dissipation of the protoplanetary disc, on time-scales of 30-100 million years. I present here a new theoretical model where terrestrial planets grow instead by accreting small pebbles in the protoplanetary disc within 3-5 million years. I discuss how the immense pebble accretion heat leads to extensive melting of the growing planets and to the emergence of deep magma oceans. Volatiles such as water, carbon and nitrogen are accreted with the pebbles and partitioned between atmosphere, magma ocean and core. The end of the accretion phase leads to rapid crystallisation of the magma ocean and outgassing of the first atmosphere. I will show how the atmospheric composition of young planets is key to understanding the origin of life.

2023-03-10
11:00
Modeling disks and jets around forming massive stars
Andre Oliva (Uni Heidelberg)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
During their early formation stages, massive stars are surrounded by accretion disks and launch powerful magnetically-driven jets and molecular outflows. The tteoretical modeling of such system poses significant challenges due to the wide range of scales and physical effects involved. Observing the innermost (embedded) material surrounding a forming massive star has only been possible recently, thanks to the use of techniques like very-long-baseline interferometry (VLBI). In this talk, I will offer a tour through simulations of massive star formation from a collapsing cloud, with emphasis on the fragmentation of accretion disks and the launch of protostellar jets. I will discuss how high spatial resolution is helping us to understand the formation of massive stellar multiple systems via disk fragmentation. Finally, I will show how a new generation of observations and simulations have come together to uncover the physics of launching protostellar jets.

2023-03-10
11:00
Modeling disks and jets around forming massive stars
Andre Oliva (Uni Heidelberg)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
During their early formation stages, massive stars are surrounded by accretion disks and launch powerful magnetically-driven jets and molecular outflows. The tteoretical modeling of such system poses significant challenges due to the wide range of scales and physical effects involved. Observing the innermost (embedded) material surrounding a forming massive star has only been possible recently, thanks to the use of techniques like very-long-baseline interferometry (VLBI). In this talk, I will offer a tour through simulations of massive star formation from a collapsing cloud, with emphasis on the fragmentation of accretion disks and the launch of protostellar jets. I will discuss how high spatial resolution is helping us to understand the formation of massive stellar multiple systems via disk fragmentation. Finally, I will show how a new generation of observations and simulations have come together to uncover the physics of launching protostellar jets.

2023-03-03
11:00
The JWST view on ice and gas
Giulia Perotti (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The interaction between interstellar dust, ice and gas plays a major role for the chemistry in regions where star and planets form. Different reactions occur in the gas and on the ice mantles of dust grains in these regions, and consequently the mutual exchange of matter between the two phases is what regulates the physical and chemical evolution of newborn stars and planets. In this talk, I will introduce recent discoveries using JWST that are advancing our understanding of this complex interplay. I will show first JWST observations of the PDS 70 planet-forming disk as part of the MIRI mid-INfrared Disk Survey (MINDS, PI: Th. Henning). The much higher sensitivity of MIRI-MRS compared with previous Spitzer data reveals emission of water vapour. This demonstrates that the terrestrial planet-forming zone of PDS 70 has maintained to some degree the physical and chemical conditions of young disks, in spite of the ~65 AU planet-induced gap.

2023-02-24
11:00
Astrochemistry: From disks to planets & moons
Inga Kamp (Kapteyn Astronomical Institute)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
In the past 20 years, new facilities such as the VLT and ALMA allowed us to spatially resolve planet forming disks and to understand the distribution and composition of the material that builds the planets and potentially moons around them. The exquisite data that we obtain from such facilities provides a top level overview of the process of planet formation, but also allows us to understand the detailed physics and chemistry at play in specific environments. Radiative transfer thermo-chemical disk models are ideal virtual laboratories to explore the complex interplay between dust and gas in disks and how this can affect and/or change our interpretation of observations. I will also show how such disk models can give novel insights into characterizing the planet and moon forming processes.

2023-02-24
11:00
Astrochemistry: From disks to planets & moons
Inga Kamp (Kapteyn Astronomical Institute)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
In the past 20 years, new facilities such as the VLT and ALMA allowed us to spatially resolve planet forming disks and to understand the distribution and composition of the material that builds the planets and potentially moons around them. The exquisite data that we obtain from such facilities provides a top level overview of the process of planet formation, but also allows us to understand the detailed physics and chemistry at play in specific environments. Radiative transfer thermo-chemical disk models are ideal virtual laboratories to explore the complex interplay between dust and gas in disks and how this can affect and/or change our interpretation of observations. I will also show how such disk models can give novel insights into characterizing the planet and moon forming processes.

2023-02-17
11:00
TBA
Giulia Perotti (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBA

2023-02-17
11:00
TBA
Chris Byrohl (ZAH/ITA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBA

2023-02-17
11:00
A new national institute for astronomical research: DZA (Deutsches Zentrum für Astrophysik)
Stefan Wagner (ZAH/LSW)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
In September 2022 the German federal ministry for research launched a new national institute for astronomical research. The DZA (Deutsches Zentrum für Astrophysik) will be based in Görlitz, Saxony, and shall enter a start-up phase in spring 2023. It is intended to support astrophysical research in Germany and implements a long-held vision of the astronomical community. Following a three-year preparatory period, the center will conduct research and provide services in technology, data science and astrophysics. A special focus shall be placed on interdisciplinary synergies.
In this seminar the motivation and rationale of the proposal that had been selected for implementation will be described along with the political and financial constraints and opportunities. During the preparatory period the strategy for the first decade shall be detailed with further community involvement. Current plans will be presented.

2023-02-17
11:00
A new national institute for astronomical research: DZA (Deutsches Zentrum für Astrophysik)
Stefan Wagner (ZAH/LSW)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
In September 2022 the German federal ministry for research launched a new national institute for astronomical research. The DZA (Deutsches Zentrum für Astrophysik) will be based in Görlitz, Saxony, and shall enter a start-up phase in spring 2023. It is intended to support astrophysical research in Germany and implements a long-held vision of the astronomical community. Following a three-year preparatory period, the center will conduct research and provide services in technology, data science and astrophysics. A special focus shall be placed on interdisciplinary synergies.
In this seminar the motivation and rationale of the proposal that had been selected for implementation will be described along with the political and financial constraints and opportunities. During the preparatory period the strategy for the first decade shall be detailed with further community involvement. Current plans will be presented.

2023-02-10
15:00
The First Astronomers: How Indigenous Elders Read the Stars
Duane Hamacher (Melbourne)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Indigenous Elders of the world are expert observers of the stars. They teach that everything on the land is reflected in the sky, and everything in the sky is reflected on the land. These living systems of knowledge challenge conventional ideas about the nature of science and the longevity of oral tradition. This talk will explore the scientific layers of Australian Indigenous star knowledge with a focus on observations of variable stars, cataclysmic stars, stellar scintillation, the motions of planets, and transient phenomena, showing how this can guide modern scientific research.

2023-02-10
15:00
The First Astronomers: How Indigenous Elders Read the Stars
Duane Hamacher (Melbourne)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Indigenous Elders of the world are expert observers of the stars. They teach that everything on the land is reflected in the sky, and everything in the sky is reflected on the land. These living systems of knowledge challenge conventional ideas about the nature of science and the longevity of oral tradition. This talk will explore the scientific layers of Australian Indigenous star knowledge with a focus on observations of variable stars, cataclysmic stars, stellar scintillation, the motions of planets, and transient phenomena, showing how this can guide modern scientific research.

2023-02-10
11:00
The First Astronomers: How Indigenous Elders Read the Stars
Duane Hamacher (Melbourne)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Indigenous Elders of the world are expert observers of the stars. They teach that everything on the land is reflected in the sky, and everything in the sky is reflected on the land. These living systems of knowledge challenge conventional ideas about the nature of science and the longevity of oral tradition. This talk will explore the scientific layers of Australian Indigenous star knowledge with a focus on observations of variable stars, cataclysmic stars, stellar scintillation, the motions of planets, and transient phenomena, showing how this can guide modern scientific research.

2023-02-03
11:00
From the Galaxy to Stars: Galactic Multi-scale Simulations of GMC and Star Cluster Formation
Ralph Pudritz (McMaster)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The advent of ALMA, JWST, and a host of recent high resolution atomic hydrogen, molecular gas, and dust surveys are transforming our understanding of star formation over a very wide range of physical scales. From large scale kpc filaments and superbubble structures, to giant molecular clouds (GMCs) on 100 pc scales, star clusters (1 pc) and the sub pc scale filaments in which we observe individual stars form, a new hierarchical and dynamic picture of star formation is emerging. I will review recent progress in simulations and theory of star formation that addresses the physical connections between structure formation from the galactic to pc scales. I will then discuss our own recent galactic multi-scale, zoom-in simulations that allows us to track the formation of structure from galactic to sub pc scales in a magnetized, Milky Way like galaxy undergoing supernova driven feedback processes. A wide variety of structures including superbubbles, kpc atomic gas filaments, smaller scale filamentary GMCs, and star cluster regions form. Gravitational instability of filaments on these different scales and filamentary flows within them, drive GMC and cluster formation respectively. In quieter regions, galactic shear can produce filamentary GMCs within flattened, rotating disk-like structures on 100 pc scales. Strikingly, magnetic field topologies associated with such disk structures are highly helical. This variety seems to reflect recent observational 3D structure maps of nearby GMCs.

2023-02-03
11:00
From the Galaxy to Stars: Galactic Multi-scale Simulations of GMC and Star Cluster Formation
Ralph Pudritz (McMaster)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The advent of ALMA, JWST, and a host of recent high resolution atomic hydrogen, molecular gas, and dust surveys are transforming our understanding of star formation over a very wide range of physical scales. From large scale kpc filaments and superbubble structures, to giant molecular clouds (GMCs) on 100 pc scales, star clusters (1 pc) and the sub pc scale filaments in which we observe individual stars form, a new hierarchical and dynamic picture of star formation is emerging. I will review recent progress in simulations and theory of star formation that addresses the physical connections between structure formation from the galactic to pc scales. I will then discuss our own recent galactic multi-scale, zoom-in simulations that allows us to track the formation of structure from galactic to sub pc scales in a magnetized, Milky Way like galaxy undergoing supernova driven feedback processes. A wide variety of structures including superbubbles, kpc atomic gas filaments, smaller scale filamentary GMCs, and star cluster regions form. Gravitational instability of filaments on these different scales and filamentary flows within them, drive GMC and cluster formation respectively. In quieter regions, galactic shear can produce filamentary GMCs within flattened, rotating disk-like structures on 100 pc scales. Strikingly, magnetic field topologies associated with such disk structures are highly helical. This variety seems to reflect recent observational 3D structure maps of nearby GMCs.

2023-01-27
11:00
Galactic and extra-galactic chemical evolution probed by SDSS
Jianhui Lian (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Galaxy chemical evolution is regulated by the interplay between galaxy internal star formation and external matter exchange with the environment (i.e. gas accretion and outflow winds). Therefore, studying galactic chemical evolution is an important way to uncover the roles played by these processes in driving galaxy formation and evolution. Sloan Digital Sky Survey (SDSS) have collected tremendous spectroscopic chemistry observations for stars in the Milky Way as well as stellar populations and ionised gas in external galaxies, which serves as ideal dataset to study galaxy chemical evolution. In this talk, I will introduce my previous works using SDSS data on both galactic and extra-galactic chemical evolution. At the end of the talk, I will share my own prospect on the future galactic/stellar chemistry studies in terms of linking the Galactic and extragalactic observations.

2023-01-27
11:00
Galactic and extra-galactic chemical evolution probed by SDSS
Jianhui Lian (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Galaxy chemical evolution is regulated by the interplay between galaxy internal star formation and external matter exchange with the environment (i.e. gas accretion and outflow winds). Therefore, studying galactic chemical evolution is an important way to uncover the roles played by these processes in driving galaxy formation and evolution. Sloan Digital Sky Survey (SDSS) have collected tremendous spectroscopic chemistry observations for stars in the Milky Way as well as stellar populations and ionised gas in external galaxies, which serves as ideal dataset to study galaxy chemical evolution. In this talk, I will introduce my previous works using SDSS data on both galactic and extra-galactic chemical evolution. At the end of the talk, I will share my own prospect on the future galactic/stellar chemistry studies in terms of linking the Galactic and extragalactic observations.

2023-01-20
11:00
Star Clusters: Constraining Gas Clearing Timescales with HST Hα Imaging and Classifying Cluster Morphology with Machine Learning
Stephen Hannon (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The analysis of star cluster ages in tandem with the detailed morphology of any associated HII regions can provide insight into the processes that clear a cluster's natal gas, as well as the accuracy of cluster ages and dust extinction derived from Spectral Energy Distribution (SED) fitting. We classify 3757 star clusters in 16 nearby (D < 10 Mpc) galaxies according to their H? morphology (concentrated, partially exposed, no emission), using HST imaging from LEGUS. Briefly, we find a relatively early onset of gas clearing and a short (1-2 Myr) clearing timescale, regardless of distance-dependent resolution effects. We also note issues between SED fitting and the age-extinction degeneracy for low-mass clusters (due to stochastic sampling effects) as well as for some massive, globular clusters, however these do not affect our reported timescales.

Additionally, the time required to produce human-inspected cluster catalogs such as those used in the above study has limited the availability of star cluster samples. To greatly expand upon these samples, deep learning models have recently been proven capable of classifying star clusters at production-scale for nearby spiral galaxies (D < 20 Mpc). In order to optimize the reliability of such models, we use HST UV-optical imaging of objects from the PHANGS-HST survey to create updated models and investigate methods of improving their performance.

2023-01-20
11:00
Star Clusters: Constraining Gas Clearing Timescales with HST Hα Imaging and Classifying Cluster Morphology with Machine Learning
Stephen Hannon (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The analysis of star cluster ages in tandem with the detailed morphology of any associated HII regions can provide insight into the processes that clear a cluster's natal gas, as well as the accuracy of cluster ages and dust extinction derived from Spectral Energy Distribution (SED) fitting. We classify 3757 star clusters in 16 nearby (D < 10 Mpc) galaxies according to their H? morphology (concentrated, partially exposed, no emission), using HST imaging from LEGUS. Briefly, we find a relatively early onset of gas clearing and a short (1-2 Myr) clearing timescale, regardless of distance-dependent resolution effects. We also note issues between SED fitting and the age-extinction degeneracy for low-mass clusters (due to stochastic sampling effects) as well as for some massive, globular clusters, however these do not affect our reported timescales.

Additionally, the time required to produce human-inspected cluster catalogs such as those used in the above study has limited the availability of star cluster samples. To greatly expand upon these samples, deep learning models have recently been proven capable of classifying star clusters at production-scale for nearby spiral galaxies (D < 20 Mpc). In order to optimize the reliability of such models, we use HST UV-optical imaging of objects from the PHANGS-HST survey to create updated models and investigate methods of improving their performance.

2023-01-13
11:00
SPHERE+ an Upgrade for the VLT's Planet Finder Instrument
Markus Feldt (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The VLT's planet finder instrument SPHERE has been in operation for 7 years now, and has generated hundreds of papers and has greatly changed our understanding of how planets form.  It does, however, have its limitation, a couple of which have been identified, and ways have been proposed to overcome them.  I will introduce you to the SPHERE+ project, which aims at improving SPHERE's planet detection capabilities further. I will detail the proposed modifications and their predicted impact on SPHERE's performance.  I will also briefly talk about the somewhat unusual organization of the project, the proposed timeline and funding, and the role of MPIA.  I will round off the last point with a brief history of MPIA's involvement in SPHERE, and in other key adaptive optics projects during the past decades.

2023-01-13
11:00
SPHERE+ an Upgrade for the VLT's Planet Finder Instrument
Markus Feldt (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The VLT's planet finder instrument SPHERE has been in operation for 7 years now, and has generated hundreds of papers and has greatly changed our understanding of how planets form.  It does, however, have its limitation, a couple of which have been identified, and ways have been proposed to overcome them.  I will introduce you to the SPHERE+ project, which aims at improving SPHERE's planet detection capabilities further. I will detail the proposed modifications and their predicted impact on SPHERE's performance.  I will also briefly talk about the somewhat unusual organization of the project, the proposed timeline and funding, and the role of MPIA.  I will round off the last point with a brief history of MPIA's involvement in SPHERE, and in other key adaptive optics projects during the past decades.

2022-12-15
14:00
The 3D structure of the Milky Way and its Molecular Clouds in the era of Gaia
:Thavisha Dharmawardena (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The detailed 3D distributions of dust density and extinction in the Milky Way have long been sought after. However, such 3D reconstruction from sparse data is non-trivial but is essential to understanding the properties of star formation, large-scale dynamics, and structure of our Galaxy. In this talk, I will introduce our new fast and scalable algorithm for 3D dust modeling, DUSTRIBUTION. Using advanced ML methods such as sparse Gaussian Processes and Variational Inference, our algorithm maps Star Formation Regions (SFRs) with millions of input sources in parsec scales within an hour on a single GPU. Our approach allows us to identify large-scale structures in star-formation regions while simultaneously peering into individual molecular clouds, providing insights into multi-scale processes such as fragmentation in molecular clouds.

In Dharmawardena et al., 2022a and b, we model the 3D dust density distribution of 16 SFRs, exploiting distances and extinctions derived from Gaia DR2 and IR data (from Fouesneau et al., 2022). From these maps, we extract 3D boundaries, volumes, precise dust masses (12% statistical uncertainty), and filling factors to study fragmentation within our regions. We recover a more comprehensive range of substructures, such as new interconnecting, free-standing filaments, star-formation feedback, and supernovae cavities. Our sample spans a wide range of environments and masses which we use to explore the variation of these parameters and their environmental effects. For example, we show that, contrary to previous suggestions, the California molecular cloud, while being more massive, is much more extended and hence more diffuse than Orion A, explaining its lower star-formation rate. We also find that Vela C exhibits a significant distance gradient along the cloud and is the most massive component of the Vela Molecular Ridge. We demonstrate it is necessary to clearly define boundaries in 3D for these clouds to determine their masses accurately. Integrating the extinction over the complete line of sight overestimates the mass over an order of magnitude. Compared to Planck data, we demonstrate for the first time that the known relationships between density and dust processing, where high-extinction lines-of-sight have the most processed grains, hold up in resolved observations and continue on more minor scales than previously suggested. In ongoing work, we map the complete Milky Way out to 3 kpc using Gaia data, recovering the dense regions of molecular clouds simultaneously along with larger-scale structures.

Finally, I will showcase our work done in collaboration with the HdA to visualize these data sets in 3D using several techniques, including on the planetarium dome and augmented reality.

2022-12-15
14:00
The 3D structure of the Milky Way and its Molecular Clouds in the era of Gaia
:Thavisha Dharmawardena (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
The detailed 3D distributions of dust density and extinction in the Milky Way have long been sought after. However, such 3D reconstruction from sparse data is non-trivial but is essential to understanding the properties of star formation, large-scale dynamics, and structure of our Galaxy. In this talk, I will introduce our new fast and scalable algorithm for 3D dust modeling, DUSTRIBUTION. Using advanced ML methods such as sparse Gaussian Processes and Variational Inference, our algorithm maps Star Formation Regions (SFRs) with millions of input sources in parsec scales within an hour on a single GPU. Our approach allows us to identify large-scale structures in star-formation regions while simultaneously peering into individual molecular clouds, providing insights into multi-scale processes such as fragmentation in molecular clouds.

In Dharmawardena et al., 2022a and b, we model the 3D dust density distribution of 16 SFRs, exploiting distances and extinctions derived from Gaia DR2 and IR data (from Fouesneau et al., 2022). From these maps, we extract 3D boundaries, volumes, precise dust masses (12% statistical uncertainty), and filling factors to study fragmentation within our regions. We recover a more comprehensive range of substructures, such as new interconnecting, free-standing filaments, star-formation feedback, and supernovae cavities. Our sample spans a wide range of environments and masses which we use to explore the variation of these parameters and their environmental effects. For example, we show that, contrary to previous suggestions, the California molecular cloud, while being more massive, is much more extended and hence more diffuse than Orion A, explaining its lower star-formation rate. We also find that Vela C exhibits a significant distance gradient along the cloud and is the most massive component of the Vela Molecular Ridge. We demonstrate it is necessary to clearly define boundaries in 3D for these clouds to determine their masses accurately. Integrating the extinction over the complete line of sight overestimates the mass over an order of magnitude. Compared to Planck data, we demonstrate for the first time that the known relationships between density and dust processing, where high-extinction lines-of-sight have the most processed grains, hold up in resolved observations and continue on more minor scales than previously suggested. In ongoing work, we map the complete Milky Way out to 3 kpc using Gaia data, recovering the dense regions of molecular clouds simultaneously along with larger-scale structures.

Finally, I will showcase our work done in collaboration with the HdA to visualize these data sets in 3D using several techniques, including on the planetarium dome and augmented reality.

2022-12-09
11:00
TBD
HHSF2022
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2022-12-09
11:00
a story
Sarah Jeffreson (CfA) : From short-lived H2 molecules to powerful feedback-driven galactic winds
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The spatial distribution and clustering of stellar feedback across galaxy discs is a key driver of galactic outflows and therefore galaxy evolution. Using a suite of high-resolution isolated galaxy simulations spanning the star-forming main sequence, I will show that clustered supernova explosions are accounted for by spatially- and temporally-coherent star formation occurring in the most massive molecular clouds. These massive molecular clouds are sustained by the constant accretion of new dense gas from the surrounding environment, in competition with the constant ejection of gas by the momentum associated with the expanding ionised regions around young massive stars. By parametrising the gas accretion rate in terms of properties of the large-scale galactic environment, I will discuss how the detailed spatial distribution of star formation and stellar feedback could be modelled as a sub-grid process in future cosmological simulations.

2022-12-09
11:00
TBD
HHSF2022
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2022-12-09
11:00
a story
Sarah Jeffreson (CfA) : From short-lived H2 molecules to powerful feedback-driven galactic winds
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The spatial distribution and clustering of stellar feedback across galaxy discs is a key driver of galactic outflows and therefore galaxy evolution. Using a suite of high-resolution isolated galaxy simulations spanning the star-forming main sequence, I will show that clustered supernova explosions are accounted for by spatially- and temporally-coherent star formation occurring in the most massive molecular clouds. These massive molecular clouds are sustained by the constant accretion of new dense gas from the surrounding environment, in competition with the constant ejection of gas by the momentum associated with the expanding ionised regions around young massive stars. By parametrising the gas accretion rate in terms of properties of the large-scale galactic environment, I will discuss how the detailed spatial distribution of star formation and stellar feedback could be modelled as a sub-grid process in future cosmological simulations.

2022-12-02
11:00
Towards molecular complexity
Thomas Henning (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The Kepler and TESS missions together with radial-velocity observations from the ground revealed that low-mass planets are frequent. A number of rocky planets have been discovered in the habitable zone around their host stars. The next big challenge is to understand the transition of terrestrial planets from geochemical systems to biogeochemical worlds. The talk will introduce the main origins of life concepts. It will discuss how molecular complexity can be reached. In addition, it will introduce the new MPIA labs and will show first results.

2022-12-02
11:00
Towards molecular complexity
Thomas Henning (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2022-12-02
11:00
Towards molecular complexity
Thomas Henning (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The Kepler and TESS missions together with radial-velocity observations from the ground revealed that low-mass planets are frequent. A number of rocky planets have been discovered in the habitable zone around their host stars. The next big challenge is to understand the transition of terrestrial planets from geochemical systems to biogeochemical worlds. The talk will introduce the main origins of life concepts. It will discuss how molecular complexity can be reached. In addition, it will introduce the new MPIA labs and will show first results.

2022-11-25
15:00
Award celebration
Patzer colloquium
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Different time slot at 3PM.

2022-11-25
15:00
Award celebration
Patzer colloquium
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Different time slot at 3PM.

2022-11-25
11:00
Award celebration
Patzer colloquium
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The award winner will present their work.

2022-11-25
11:00
Award celebration
Patzer colloquium
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
The award winner will present their work.

2022-11-25
11:00
Award celebration
Patzer colloquium
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
The award winner will present their work.

2022-11-25
11:00
Award celebration
Patzer colloquium
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The award winner will present their work.

2022-11-18
11:00
Unveiling the complexities of massive star clusters
Richard de Grijs (Macquarie U.)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Around the turn of the last century, star clusters of all kinds were considered ‘simple' stellar populations. Over the past decade, this situation has changed dramatically. At the same time, star clusters are among the brightest stellar population components and, as such, they are visible out to much greater distances than individual stars, even the brightest, so that understanding the intricacies of star cluster composition and their evolution is imperative for understanding stellar populations and the evolution of galaxies as a whole. In this review of where the field has moved to in recent years, we place particular emphasis on the properties and importance of the effects of rapid stellar rotation, and the presence of multiplicity among the red-giant-branch populations in Magellanic Cloud star clusters with ages up to a few billion years.

2022-11-18
11:00
Unveiling the complexities of massive star clusters
Richard de Grijs (Macquarie U.)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Around the turn of the last century, star clusters of all kinds were considered ‘simple' stellar populations. Over the past decade, this situation has changed dramatically. At the same time, star clusters are among the brightest stellar population components and, as such, they are visible out to much greater distances than individual stars, even the brightest, so that understanding the intricacies of star cluster composition and their evolution is imperative for understanding stellar populations and the evolution of galaxies as a whole. In this review of where the field has moved to in recent years, we place particular emphasis on the properties and importance of the effects of rapid stellar rotation, and the presence of multiplicity among the red-giant-branch populations in Magellanic Cloud star clusters with ages up to a few billion years.

2022-11-11
11:00
Is the Stellar Initial Mass Function Truly Universal?
Charles Steinhardt (DAWN)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Current techniques for analyzing large photometric catalogs are generally forced to assume a single, universal stellar initial mass function (IMF), although the IMF should be expected to vary depending upon conditions within a star-forming galaxy. The introduction of an additional parameter into photometric template fitting allows galaxies to be fit with a range of different IMFs. Most galaxies are best fit with a bottom-lighter IMF than the Milky Way, and this change in IMF also modifies inferred properties such as stellar mass and star formation rate. Several surprising new features appear, including significant constraints on the feedback mechanisms responsible for star formation and subsequent quenching. Additionally, the same techniques might indicate that most galaxies go through an earliest phase of star formation dominated by different feedback mechanisms and centered in galactic cores prior to the more typical star formation at later times.

2022-11-11
11:00
Is the Stellar Initial Mass Function Truly Universal?
Charles Steinhardt (DAWN)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Current techniques for analyzing large photometric catalogs are generally forced to assume a single, universal stellar initial mass function (IMF), although the IMF should be expected to vary depending upon conditions within a star-forming galaxy. The introduction of an additional parameter into photometric template fitting allows galaxies to be fit with a range of different IMFs. Most galaxies are best fit with a bottom-lighter IMF than the Milky Way, and this change in IMF also modifies inferred properties such as stellar mass and star formation rate. Several surprising new features appear, including significant constraints on the feedback mechanisms responsible for star formation and subsequent quenching. Additionally, the same techniques might indicate that most galaxies go through an earliest phase of star formation dominated by different feedback mechanisms and centered in galactic cores prior to the more typical star formation at later times.

2022-11-04
11:00
TBD
Mateusz Ruszkowski (University of Michigan)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2022-11-04
11:00
TBD
Mateusz Ruszkowski (University of Michigan)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2022-11-04
11:00
The role of cosmic rays, magnetic fields, and turbulence in AGN feedback
Mateusz Ruszkowski (University of Michigan)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
AGN play central role in shaping the properties of galaxies and solving the decades-old cooling flow problem. In this talk, I will discuss recent developments in the field of AGN jet feedback. I will focus on the role of cosmic rays, magnetic fields, and turbulence in shaping the observational properties of hot gaseous halos and on theoretical aspects of the energy transfer from the AGN jets to the ambient medium, i.e., the circumgalactic and intracluster medium (CGM and ICM, respectively). I will begin by discussing an example of supermassive black hole (SMBH) feedback in our own Galactic ''backyard'' — the Fermi Bubbles observed by Fermi in gamma-rays, Planck in microwaves, and, most recently, by eROSITA in X-rays. I will then discuss AGN jet feedback in elliptical galaxies and galaxy clusters. Specifically, I will discuss three new surprising findings: (i) that cosmic ray streaming heating is an important new channel for the AGN energy thermalization in the feedback process, (ii) that even extremely weak magnetic fields can dramatically alter the dynamics of the cold gas precipitation out of the CGM and ICM and feeding the SMBH, and (iii) that, contrary to textbook expectation, turbulence in the CGM/ICM may be non-Kolmogorov in nature. All of these findings have implications for the interpretation of observational results and for our understanding of AGN feedback in general.

2022-11-04
11:00
TBD
Mateusz Ruszkowski (University of Michigan)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2022-11-04
11:00
The role of cosmic rays, magnetic fields, and turbulence in AGN feedback
Mateusz Ruszkowski (University of Michigan)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
AGN play central role in shaping the properties of galaxies and solving the decades-old cooling flow problem. In this talk, I will discuss recent developments in the field of AGN jet feedback. I will focus on the role of cosmic rays, magnetic fields, and turbulence in shaping the observational properties of hot gaseous halos and on theoretical aspects of the energy transfer from the AGN jets to the ambient medium, i.e., the circumgalactic and intracluster medium (CGM and ICM, respectively). I will begin by discussing an example of supermassive black hole (SMBH) feedback in our own Galactic ''backyard'' — the Fermi Bubbles observed by Fermi in gamma-rays, Planck in microwaves, and, most recently, by eROSITA in X-rays. I will then discuss AGN jet feedback in elliptical galaxies and galaxy clusters. Specifically, I will discuss three new surprising findings: (i) that cosmic ray streaming heating is an important new channel for the AGN energy thermalization in the feedback process, (ii) that even extremely weak magnetic fields can dramatically alter the dynamics of the cold gas precipitation out of the CGM and ICM and feeding the SMBH, and (iii) that, contrary to textbook expectation, turbulence in the CGM/ICM may be non-Kolmogorov in nature. All of these findings have implications for the interpretation of observational results and for our understanding of AGN feedback in general.

2022-10-28
11:00
TBA
Niv Drory (U. of Texas/Austin)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2022-10-28
11:00
TBA
Niv Drory (U. of Texas/Austin)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2022-10-28
11:00
TBA
Niv Drory (U. of Texas/Austin)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2022-10-28
11:00
The Local Volume Mapper (LVM) Survey in SDSS-V: IFU spectroscopy of the Milky Way and Magellanic Clouds
Niv Drory (UT Austin)
Königstuhl Kolloquium
MPIA lecture hall,
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Abstract
The SDSS-V Local Volume Mapper (LVM) is an IFU survey covering 3500 sq degrees in the MW disk at 0.1-1 pc resolution and the Magellanic Clouds at 10 pc resolution, in total about 1 steradian of sky. It uses a full-moon sized fiber-fed IFU feeding spectrographs covering the full optical bandpass at R~4000 (4800 at Ha). LVM finely resolves star forming structures, GMCs, H II regions, diffuse gas and filaments, nebulae, and young stellar clusters across a wide range of physical parameters and environments. Ancillary data provide stellar spectroscopy from SDSS-III,IV and V, resolved (spectro-)photometry of individual stars and color-magnitude diagrams (CMDs), and X-Ray to radio data from a multitude of surveys. LVM probes the radiation field and wind momentum input of stars back into the ISM and together with the wide coverage addresses feedback from the single star scale up to kpc and galactic scales. It also addresses many open science questions regarding the composition, physical state and conditions in the ISM. Key science topics include the injection of feedback into the ISM, the star formation efficiency dependence on galactic environment, precision abundance diagnostics, the diffusion of heavy elements, the heating mechanisms of the diffuse ionized gas, the ionization structure of HII regions, the time evolution of star forming structures, and many other topics.

2022-10-21
11:00
TBC
Deanne Fisher (Swinburne U.)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2022-10-21
11:00
TBC
Deanne Fisher (Swinburne U.)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2022-10-21
11:00
TBC
Deanne Fisher (Swinburne U.)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2022-10-21
11:00
TBC
Deanne Fisher (Swinburne U.)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2022-10-21
11:00
Physical and chemical properties during high-mass star formation
Caroline Gieser (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
During high-mass star formation, fragmentation takes place on various spatial scales from giant molecular clouds down to disk scales. At the earliest evolutionary stages, high-mass protostars are still deeply embedded within their parental molecular cloud and can be studied best at high spatial resolution with interferometers at mm wavelengths.
The IRAM/NOEMA large program "CORE" allows us to analyze the physical and chemical properties of a sample of luminous high-mass star-forming regions. The 1 mm dust continuum of the sample shows a large diversity of fragmentation properties. Using the spectral line emission, we characterize the physical structure (temperature an density) and quantify the molecular content of individual fragmented cores. Even though all regions are classified to harbor high-mass protostellar objects, the molecular content shows a high degree of complexity. By combining the observed core properties, we are able to estimate chemical timescales with the physical-chemical model MUSCLE.
We find well-constrained density and temperature profiles in agreement with theoretical predictions. The molecular complexity in the core spectra can be explained by an age spread that is then confirmed by our physical-chemical modeling. The hot molecular cores show the greatest number of emission lines, but we also find evolved cores in which most molecules are destroyed and, thus, the spectra appear line-poor once again. We increased our sample with ALMA 3mm observations of 11 additional high-mass star-forming regions at different evolutionary stages - from infrared dark clouds to ultra-compact HII regions - in order to further investigate the evolution of the physical and chemical properties on core scales.

2022-10-14
11:00
TBA
Sabine Thater (University Vienna)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBA

2022-10-14
11:00
TBA
Sabine Thater (University Vienna)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBA

2022-10-14
11:00
TBA
Sabine Thater (University Vienna)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBA

2022-10-14
11:00
Expanding the extreme ends of the massive black hole scaling relations with dynamical modelling
Sabine Thater (University Vienna)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
By now more than hundred massive black hole (MBH) mass measurements of local galaxies based on stellar or gaseous motion reveal strong correlations of the MBH mass with their bulge properties, such as bulge mass, stellar velocity dispersion (sigma) and light concentration. Determining MBH masses is a challenging procedure and it is not possible to use one single method across the full sample of galaxies. Problematically, measurements from different dynamical tracers often give discrepant results, rising the question whether the variety of methods forces an additional bias on the scaling relations. Therefore, connecting mass results from different methods is necessary to evaluate the robustness and universality of the measurement results and thus crucial for improving the understanding of the interplay between the central black holes and their host galaxies.

I will present two projects to address the following questions: Do high-mass and low-mass black holes follow the same scaling relations? Does the variety of mass measurement methods force an additional bias on the scaling relations? I will show two independent black hole determinations from the early-type galaxy NGC 6958 based on stellar kinematics (MUSE) and molecular gas kinematics (ALMA), taking special care in revisiting the associated measurement errors, specifically, the systematics associated with the dynamical methods, and the general accuracy of black hole mass measurements. NGC 6958 is part of the SMASHING sample of 20 early-type galaxies which expand the black hole scaling relations on both the high and low mass end. I will discuss the dynamically measured black hole masses in the SMASHING sample in context of the MBH mass-sigma relation. Finally, I will give an outlook to new features in the triaxial Schwarzschild chemo-dynamical modelling code that is developed in Vienna.

2022-10-07
11:00
TBD
Ralf Klessen (ITA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2022-10-07
11:00
TBD
Ralf Klessen (ITA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2022-10-07
11:00
TBD
Ralf Klessen (ITA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2022-10-07
11:00
TBD
Ralf Klessen (ITA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2022-09-30
11:00
A Tapestry of Starlight and Supermassive Black Holes
Alyssa Drake (Hertfordshire)
Königstuhl Kolloquium
MPIA lecture hall,
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Abstract
As new astronomical facilities come online, they offer the opportunity to transform our understanding of the Universe. One such facility is The International LOFAR Telescope, which is opening new parameter space in the low-frequency radio sky through its unprecedented combination of sensitivity, areal coverage and spatial resolution. In particular, the LOFAR Two Metre Sky Survey (LoTSS) is surveying the entire northern sky at 150MHz to a depth of ~100 micro Jy, already providing a sample of > 4 million extragalactic radio sources, and gathering statistical samples of both extreme quasars in the early Universe, and 'typical' star-forming galaxies across vast swathes of cosmic time. I will outline our current understanding of the build up of the first supermassive black holes, and the evolution of cosmic star formation, using state-of-the art facilities (e.g. MUSE and ALMA), before discussing how the advent of massively-multiplexed spectroscopic facilities such as WEAVE will unlock the immense potential of the LOFAR surveys. For instance, by providing > 1 million optical spectra of radio-selected sources, the WEAVE-LOFAR survey will be able to distinguish between star-formation and AGN, accretion modes in AGN, and ultimately enable us to understand the complex interplay between star formation and accretion from z~7 to the present day.

2022-09-23
11:00
TBD
Raphaël Errani (Obs. Strasbourg)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2022-09-23
11:00
TBD
Raphaël Errani (Obs. Strasbourg)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2022-09-23
11:00
TBD
Raphaël Errani (Obs. Strasbourg)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2022-09-23
11:00
Structure and kinematics of tidally limited satellite galaxies in LCDM
Raphaël Errani (Obs. Strasbourg)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract

Abstract: In the cold dark matter model, we think the Milky Way \;hosts many dark matter subhalos - some of them host luminous dwarf galaxies, others devoid of stars. \;In this talk, I'll discuss how cold dark matter substructures get trimmed down due to the Milky Way tidal field and how this affects embedded dwarf galaxies. \;In particular, I'll show that if dark matter subhalos have centrally-divergent density cusps, they are very resilient to tidal effects, and the sizes and velocity dispersions of heavily-stripped Milky Way satellite galaxies are set by the properties of their underlying dark matter subhalos. \;The results raise challenging questions about the nature of dark matter on galactic scales, as the existence of extended and dynamically cold Milky Way satellite galaxies, like the Crater 2 and Antlia 2 dwarfs, appears in conflict with simple predictions from cold dark matter models. \;


2022-09-16
11:00
TBA
Kathryn Kreckel (ZAH/ARI)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBA

2022-09-16
11:00
TBA
Kathryn Kreckel (ZAH/ARI)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBA

2022-09-16
11:00
TBA
Kathryn Kreckel (ZAH/ARI)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBA

2022-09-16
11:00
Resolving the Baryon Cycle within Nearby Galaxies

Kathryn Kreckel (ZAH/ARI)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The buildup of stellar mass through star formation is driven on small (<100pc) scales by physical processes and local conditions, but regulated across larger (kpc) scales through the baryon cycle. This entails the transformation of gas into stars, and eventual ejection and recycling of material to form the next generation of stars. The ionized interstellar medium (ISM) provides crucial insights into these processes, particularly our understanding of radiative and mechanical feedback from young massive stars. The PHANGS (Physics at High Angular resolution in Nearby GalaxieS) collaboration is building a library of uniform, high-quality, high-resolution observations of nearby galaxies at the critical “cloud scale” across star-forming galaxy disks by using observations from Hubble, MUSE/VLT, JWST, and ALMA. This provides a characterization of the young star clusters, the ionized HII regions, the supernova remnants and the giant molecular clouds, with which we we can explore a comprehensive view of the star-formation process. I will present new results from my group, which has focused on quantifying the impact of these stellar feedback processes on the ISM. I will show how we are leveraging our large statistical samples to establish an evolutionary sequence for HII regions, linking ionized nebulae with their powering stellar sources. In charting the late-time and large-scale feedback, I will show how morphological identification of bubbles in molecular and ionized gas, and now with JWST in the dust, provides quantitative constraints on different feedback mechanisms.

2022-09-09
11:00
TBD
Camille Bergez (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2022-09-09
11:00
TBD
Camille Bergez (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2022-09-09
11:00
TBD
Camille Bergez (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2022-09-09
11:00
How the formation of multiple giant planets can impact their own growth and the structure of their protoplanetary disk
Camille Bergez (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Giant planets are partly formed by accretion of the gas present in the protoplanetary disk surrounding them. This process influences the shape of the protoplanetary disk as well as the growth of the giants themselves when considering more than one giant forming at the same time. I will present the results of my hydrodynamical simulations which investigate the evolution of the masses of the planets as a function of time as well as the evolution of the structures present in the protoplanetary disk. I will link these two quantities to observations of protoplanetary disks as well as the distributions of characteristics of the observed exoplanets.

2022-09-05
12:40
D
D (D)
Königstuhl Kolloquium
D, D
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Abstract
D

2022-09-02
11:00
Updates to the Maunakea Spectroscopic Explorer: Thousands of Fibers, Infinite Possibilities
: Andrew Sheinis (CFHT)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
MSE is a massively multiplexed spectroscopic survey facility that will replace the Canada-France-Hawaii-Telescope in the coming decade. This 11.25-m telescope, with its 1.5 square degree field-of-view, will observe 4,000 – 20,000 astronomical targets in every pointing by using fibers to pick up the light at the prime focus w and transmitting it to banks of low/moderate (R=3,000/6,000) and high (R=30,000) resolution spectrographs. Piezo actuators position individual fibers in the field of view to enable simultaneous full field coverage for both resolution modes. MSE will unveil the composition and dynamics of the faint Universe and impact nearly every ?eld of astrophysics across all spatial scales, from individual stars to the largest scale structures in the Universe, including (i) the ultimate Gaia follow-up facility for understanding the chemistry and dynamics of the distant Milky Way, including the outer disk and faint stellar halo at high spectral resolution (ii) galaxy formation and evolution at cosmic noon, (iii) derivation of the mass of the neutrino and insights into in?ationary physics through a cosmological redshift survey that probes a large volume of the Universe with a high galaxy density. The instrument suite, dedicated to large scale surveys, will enable MSE to collect a massive amount of data: equivalent to a full SDSS Legacy Survey every 7 weeks. We present an update to the major systems development for MSE along with the ongoing process of evaluating improvements to the baseline telescope design. In addition, we present the plan to develop a Pathfinder instrument at CFHT to fast-track development of the MSE technology as well as provide a the only wide-field spectroscopic capability in the visible and NIR in the Northern Hemisphere later in this decade.

2022-08-05
11:00
TBA
David Hogg (NYU, Flation Institute)
Königstuhl Kolloquium
MPIA lecture hall,
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Abstract
TBA

2022-08-05
11:00
TBA
David Hogg (NYU, Flation Institute)
Königstuhl Kolloquium
MPIA lecture hall,
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Abstract
TBA

2022-08-05
11:00
TBA
David Hogg (NYU, Flation Institute)
Königstuhl Kolloquium
MPIA lecture hall,
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Abstract
TBA

2022-08-05
11:00
Fitting very flexible models\n
David Hogg (NYU, Flation Institute)
Königstuhl Kolloquium
MPIA lecture hall,
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Abstract

Linear fitting is often used for interpolation of data, for example when you have calibration data and you want to fit a smooth, flexible function. Or you want to de-trend a time series or normalize a spectrum. I will discuss how this fitting is done, with ordinary least squares and extensions thereof. Extremely surprisingly, it is often valuable to choose far more parameters than data points, despite folk rules to the contrary\; over-fitting is not (mainly) a problem of having too many parameters. It is even possible to take the limit of infinite parameters, at which a regularized least-squares fit can become the mean of a Gaussian process, which is a very useful model. I recommend cross-validation as a practical method for model selection, and jackknife resampling as a practical method for estimating the uncertainties of the predictions made by the model. (work with Soledad Villar)




2022-07-29
11:00
Recent updates and highlights in high-contrast imaging of exoplanets
Matthias Samland (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The first generation of dedicated high-contrast imaging \;instrumentation has seen first light around 8 years ago (SPHERE, GPI), \;and a lot has changed in the intervening years. In this talk I provide \;an overview of recent development in instrumentation, data reduction, \;and atmospheric characterization (yes, also some JWST images).

2022-07-29
11:00
Recent updates and highlights in high-contrast imaging of exoplanets
Matthias Samland (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
The first generation of dedicated high-contrast imaging \;instrumentation has seen first light around 8 years ago (SPHERE, GPI), \;and a lot has changed in the intervening years. In this talk I provide \;an overview of recent development in instrumentation, data reduction, \;and atmospheric characterization (yes, also some JWST images).

2022-07-29
11:00
Recent updates and highlights in high-contrast imaging of exoplanets
Matthias Samland (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
The first generation of dedicated high-contrast imaging \;instrumentation has seen first light around 8 years ago (SPHERE, GPI), \;and a lot has changed in the intervening years. In this talk I provide \;an overview of recent development in instrumentation, data reduction, \;and atmospheric characterization (yes, also some JWST images).

2022-07-29
11:00
Recent updates and highlights in high-contrast imaging of exoplanets
Matthias Samland (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
The first generation of dedicated high-contrast imaging \;instrumentation has seen first light around 8 years ago (SPHERE, GPI), \;and a lot has changed in the intervening years. In this talk I provide \;an overview of recent development in instrumentation, data reduction, \;and atmospheric characterization (yes, also some JWST images).

2022-07-22
11:00
[Fe/H] and [a/Fe] from spectra of red giant stars across M31, M33, and beyond
Leigh Wojno (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
We present chemical abundances of red giant branch stars in the Andromeda (M31) system, including its dwarf satellites, as well as M33. We use spectral synthesis to obtain individual and coadded spectroscopic abundance measurements from R~6000 NIR spectra obtained as part of the Spectroscopic and Photometric Landscape of Andromeda's Stellar Halo (SPLASH) survey. Spectra with insufficient S/N to determine individual abundance measurements are binned according to their photometric metallicity and coadded to obtain mean [Fe/H] and [a/Fe] for groups of similar stars. Using both individual and coadded abundance measurements, we measure a radial metallicity gradient in both [Fe/H] and [a/Fe] for stars associated with the “smooth” halo of M31, of -0.005±0.003 and 0.0034±0.0004 dex kpc-1, respectively. For stars more likely to be associated with substructure, we measure a similar gradient in [Fe/H], but do not find evidence for a radial gradient in [a/Fe]. Radial abundance gradients are associated with "inside out" galaxy formation, and we compare these gradients to those measured for the Milky Way. Finally, we explore the 2D [a/Fe]-[Fe/H] abundance space for M31, its satellite galaxies, and M33. By putting these abundance measurements into context with the local group, we aim to identify critical differences in the star formation and accretion history of M31 compared to that of our own Galaxy.

2022-07-22
11:00
[Fe/H] and [a/Fe] from spectra of red giant stars across M31, M33, and beyond
Leigh Wojno (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
We present chemical abundances of red giant branch stars in the Andromeda (M31) system, including its dwarf satellites, as well as M33. We use spectral synthesis to obtain individual and coadded spectroscopic abundance measurements from R~6000 NIR spectra obtained as part of the Spectroscopic and Photometric Landscape of Andromeda's Stellar Halo (SPLASH) survey. Spectra with insufficient S/N to determine individual abundance measurements are binned according to their photometric metallicity and coadded to obtain mean [Fe/H] and [a/Fe] for groups of similar stars. Using both individual and coadded abundance measurements, we measure a radial metallicity gradient in both [Fe/H] and [a/Fe] for stars associated with the “smooth” halo of M31, of -0.005±0.003 and 0.0034±0.0004 dex kpc-1, respectively. For stars more likely to be associated with substructure, we measure a similar gradient in [Fe/H], but do not find evidence for a radial gradient in [a/Fe]. Radial abundance gradients are associated with "inside out" galaxy formation, and we compare these gradients to those measured for the Milky Way. Finally, we explore the 2D [a/Fe]-[Fe/H] abundance space for M31, its satellite galaxies, and M33. By putting these abundance measurements into context with the local group, we aim to identify critical differences in the star formation and accretion history of M31 compared to that of our own Galaxy.

2022-07-22
11:00
[Fe/H] and [a/Fe] from spectra of red giant stars across M31, M33, and beyond
Leigh Wojno (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
We present chemical abundances of red giant branch stars in the Andromeda (M31) system, including its dwarf satellites, as well as M33. We use spectral synthesis to obtain individual and coadded spectroscopic abundance measurements from R~6000 NIR spectra obtained as part of the Spectroscopic and Photometric Landscape of Andromeda's Stellar Halo (SPLASH) survey. Spectra with insufficient S/N to determine individual abundance measurements are binned according to their photometric metallicity and coadded to obtain mean [Fe/H] and [a/Fe] for groups of similar stars. Using both individual and coadded abundance measurements, we measure a radial metallicity gradient in both [Fe/H] and [a/Fe] for stars associated with the “smooth” halo of M31, of -0.005±0.003 and 0.0034±0.0004 dex kpc-1, respectively. For stars more likely to be associated with substructure, we measure a similar gradient in [Fe/H], but do not find evidence for a radial gradient in [a/Fe]. Radial abundance gradients are associated with "inside out" galaxy formation, and we compare these gradients to those measured for the Milky Way. Finally, we explore the 2D [a/Fe]-[Fe/H] abundance space for M31, its satellite galaxies, and M33. By putting these abundance measurements into context with the local group, we aim to identify critical differences in the star formation and accretion history of M31 compared to that of our own Galaxy.

2022-07-22
11:00
[Fe/H] and [a/Fe] from spectra of red giant stars across M31, M33, and beyond
Leigh Wojno (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
We present chemical abundances of red giant branch stars in the Andromeda (M31) system, including its dwarf satellites, as well as M33. We use spectral synthesis to obtain individual and coadded spectroscopic abundance measurements from R~6000 NIR spectra obtained as part of the Spectroscopic and Photometric Landscape of Andromeda's Stellar Halo (SPLASH) survey. Spectra with insufficient S/N to determine individual abundance measurements are binned according to their photometric metallicity and coadded to obtain mean [Fe/H] and [a/Fe] for groups of similar stars. Using both individual and coadded abundance measurements, we measure a radial metallicity gradient in both [Fe/H] and [a/Fe] for stars associated with the “smooth” halo of M31, of -0.005±0.003 and 0.0034±0.0004 dex kpc-1, respectively. For stars more likely to be associated with substructure, we measure a similar gradient in [Fe/H], but do not find evidence for a radial gradient in [a/Fe]. Radial abundance gradients are associated with "inside out" galaxy formation, and we compare these gradients to those measured for the Milky Way. Finally, we explore the 2D [a/Fe]-[Fe/H] abundance space for M31, its satellite galaxies, and M33. By putting these abundance measurements into context with the local group, we aim to identify critical differences in the star formation and accretion history of M31 compared to that of our own Galaxy.

2022-07-15
11:00
Large-Scale Structure Cosmology in the Systematics-Limited Regime
Elizabeth Krause (University of Arizona)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Over the next decade, large galaxy surveys will map billions of galaxies and probe cosmic structure formation with high statistical precision. This talk will outline opportunities and challenges of cosmological analyses in the presence of complex systematic effects using recent results from the Dark Energy Survey as pathfinder examples. In particular, I will describe different cosmological probes measured from photometric data and summarize the recent progress on combining galaxy clustering, weak lensing, cluster clustering and cluster abundances, as well as constraints on baryons and galaxy biasing from small scales. I will conclude with an outlook on cosmology analysis plans and challenges for future, much larger experiments such as Rubin Observatory's LSST, Roman Space Telescope and overlapping Cosmic Microwave Background surveys.

2022-07-15
11:00
Large-Scale Structure Cosmology in the Systematics-Limited Regime
Elizabeth Krause (University of Arizona)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Over the next decade, large galaxy surveys will map billions of galaxies and probe cosmic structure formation with high statistical precision. This talk will outline opportunities and challenges of cosmological analyses in the presence of complex systematic effects using recent results from the Dark Energy Survey as pathfinder examples. In particular, I will describe different cosmological probes measured from photometric data and summarize the recent progress on combining galaxy clustering, weak lensing, cluster clustering and cluster abundances, as well as constraints on baryons and galaxy biasing from small scales. I will conclude with an outlook on cosmology analysis plans and challenges for future, much larger experiments such as Rubin Observatory's LSST, Roman Space Telescope and overlapping Cosmic Microwave Background surveys.

2022-07-15
11:00
Large-Scale Structure Cosmology in the Systematics-Limited Regime
Elizabeth Krause (University of Arizona)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Over the next decade, large galaxy surveys will map billions of galaxies and probe cosmic structure formation with high statistical precision. This talk will outline opportunities and challenges of cosmological analyses in the presence of complex systematic effects using recent results from the Dark Energy Survey as pathfinder examples. In particular, I will describe different cosmological probes measured from photometric data and summarize the recent progress on combining galaxy clustering, weak lensing, cluster clustering and cluster abundances, as well as constraints on baryons and galaxy biasing from small scales. I will conclude with an outlook on cosmology analysis plans and challenges for future, much larger experiments such as Rubin Observatory's LSST, Roman Space Telescope and overlapping Cosmic Microwave Background surveys.

2022-07-15
11:00
Large-Scale Structure Cosmology in the Systematics-Limited Regime
Elizabeth Krause (University of Arizona)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Over the next decade, large galaxy surveys will map billions of galaxies and probe cosmic structure formation with high statistical precision. This talk will outline opportunities and challenges of cosmological analyses in the presence of complex systematic effects using recent results from the Dark Energy Survey as pathfinder examples. In particular, I will describe different cosmological probes measured from photometric data and summarize the recent progress on combining galaxy clustering, weak lensing, cluster clustering and cluster abundances, as well as constraints on baryons and galaxy biasing from small scales. I will conclude with an outlook on cosmology analysis plans and challenges for future, much larger experiments such as Rubin Observatory's LSST, Roman Space Telescope and overlapping Cosmic Microwave Background surveys.

2022-07-08
11:00
ANDES & The Promise of High Resolution Spectroscopy of Exoplanets
Wolfgang Gässler (MPIA) & Paul Mollière (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
High resolution spectroscopy is a powerful tool for many fields of astronomy, particularly exoplanet atmosphere characterization. In this talk we will introduce the ArmazoNes high Dispersion Echelle Spectrograph (ANDES), a planned ELT second-light instrument. ANDES will provide high resolution spectroscopy from optical wavelengths through the near-infrared (0.4-1.8 micron). We will give an overview of the instrument and discuss key exoplanet science cases, including measurements of the chemical composition, atmospheric dynamics, spin, and cloud properties. We will also discuss MPIA's planned contributions to the project, including a design study for expanding the instrument's wavelength coverage into the K band.

2022-07-08
11:00
ANDES & The Promise of High Resolution Spectroscopy of Exoplanets
Wolfgang Gässler (MPIA) & Paul Mollière (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
High resolution spectroscopy is a powerful tool for many fields of astronomy, particularly exoplanet atmosphere characterization. In this talk we will introduce the ArmazoNes high Dispersion Echelle Spectrograph (ANDES), a planned ELT second-light instrument. ANDES will provide high resolution spectroscopy from optical wavelengths through the near-infrared (0.4-1.8 micron). We will give an overview of the instrument and discuss key exoplanet science cases, including measurements of the chemical composition, atmospheric dynamics, spin, and cloud properties. We will also discuss MPIA's planned contributions to the project, including a design study for expanding the instrument's wavelength coverage into the K band.

2022-07-08
11:00
ANDES & The Promise of High Resolution Spectroscopy of Exoplanets
Wolfgang Gässler (MPIA) & Paul Mollière (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
High resolution spectroscopy is a powerful tool for many fields of astronomy, particularly exoplanet atmosphere characterization. In this talk we will introduce the ArmazoNes high Dispersion Echelle Spectrograph (ANDES), a planned ELT second-light instrument. ANDES will provide high resolution spectroscopy from optical wavelengths through the near-infrared (0.4-1.8 micron). We will give an overview of the instrument and discuss key exoplanet science cases, including measurements of the chemical composition, atmospheric dynamics, spin, and cloud properties. We will also discuss MPIA's planned contributions to the project, including a design study for expanding the instrument's wavelength coverage into the K band.

2022-07-08
11:00
ANDES & The Promise of High Resolution Spectroscopy of Exoplanets
Wolfgang Gässler (MPIA) & Paul Mollière (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
High resolution spectroscopy is a powerful tool for many fields of astronomy, particularly exoplanet atmosphere characterization. In this talk we will introduce the ArmazoNes high Dispersion Echelle Spectrograph (ANDES), a planned ELT second-light instrument. ANDES will provide high resolution spectroscopy from optical wavelengths through the near-infrared (0.4-1.8 micron). We will give an overview of the instrument and discuss key exoplanet science cases, including measurements of the chemical composition, atmospheric dynamics, spin, and cloud properties. We will also discuss MPIA's planned contributions to the project, including a design study for expanding the instrument's wavelength coverage into the K band.

2022-07-01
11:00
TBD
Giulia Perotti (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2022-07-01
11:00
TBD
Matthias Samland (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2022-07-01
11:00
3D magneto-hydrodynamical model atmospheres: the influence of surface magnetism on the center-to-limb variation of solar-type stars
Hans-Günter Ludwig (LSW)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Observations indicate that magnetic activity has an influence on the center-to-limb variation (CLV) of solar-type stars. In my presentation, I review the magnetic activity of the Sun as template of activity of solar-type stars in general. I further review the observations conducted with the Kepler space observatory on transiting exo-planetary systems that motivated my project on the CLV. With the help of 3D magneto-hydrodynamical (MHD) model atmospheres a theoretical description of the observation is attempted. I describe the properties of the MHD models relevant for the project. MHD models are constructed which differ in the mean magnetic field strength. They are considered as elements suitable to build-up the stellar surface. Their radiative output for various stellar limb angles is calculated and compared to the measurements. A partial correspondence is achieved, however, discrepancies remain that may be of observational or theoretical origin. Not directly related to the project, and if time permits, I will finally comment on the impact of magnetic activity on Gaia photometry.

2022-07-01
11:00
3D magneto-hydrodynamical model atmospheres: the influence of surface magnetism on the center-to-limb variation of solar-type stars
Hans-Günter Ludwig (LSW)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Observations indicate that magnetic activity has an influence on the center-to-limb variation (CLV) of solar-type stars. In my presentation, I review the magnetic activity of the Sun as template of activity of solar-type stars in general. I further review the observations conducted with the Kepler space observatory on transiting exo-planetary systems that motivated my project on the CLV. With the help of 3D magneto-hydrodynamical (MHD) model atmospheres a theoretical description of the observation is attempted. I describe the properties of the MHD models relevant for the project. MHD models are constructed which differ in the mean magnetic field strength. They are considered as elements suitable to build-up the stellar surface. Their radiative output for various stellar limb angles is calculated and compared to the measurements. A partial correspondence is achieved, however, discrepancies remain that may be of observational or theoretical origin. Not directly related to the project, and if time permits, I will finally comment on the impact of magnetic activity on Gaia photometry.

2022-07-01
11:00
3D magneto-hydrodynamical model atmospheres: the influence of surface magnetism on the center-to-limb variation of solar-type stars
Hans-Günter Ludwig (LSW)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Observations indicate that magnetic activity has an influence on the center-to-limb variation (CLV) of solar-type stars. In my presentation, I review the magnetic activity of the Sun as template of activity of solar-type stars in general. I further review the observations conducted with the Kepler space observatory on transiting exo-planetary systems that motivated my project on the CLV. With the help of 3D magneto-hydrodynamical (MHD) model atmospheres a theoretical description of the observation is attempted. I describe the properties of the MHD models relevant for the project. MHD models are constructed which differ in the mean magnetic field strength. They are considered as elements suitable to build-up the stellar surface. Their radiative output for various stellar limb angles is calculated and compared to the measurements. A partial correspondence is achieved, however, discrepancies remain that may be of observational or theoretical origin. Not directly related to the project, and if time permits, I will finally comment on the impact of magnetic activity on Gaia photometry.

2022-07-01
11:00
3D magneto-hydrodynamical model atmospheres: the influence of surface magnetism on the center-to-limb variation of solar-type stars
Hans-Günter Ludwig (LSW)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Observations indicate that magnetic activity has an influence on the center-to-limb variation (CLV) of solar-type stars. In my presentation, I review the magnetic activity of the Sun as template of activity of solar-type stars in general. I further review the observations conducted with the Kepler space observatory on transiting exo-planetary systems that motivated my project on the CLV. With the help of 3D magneto-hydrodynamical (MHD) model atmospheres a theoretical description of the observation is attempted. I describe the properties of the MHD models relevant for the project. MHD models are constructed which differ in the mean magnetic field strength. They are considered as elements suitable to build-up the stellar surface. Their radiative output for various stellar limb angles is calculated and compared to the measurements. A partial correspondence is achieved, however, discrepancies remain that may be of observational or theoretical origin. Not directly related to the project, and if time permits, I will finally comment on the impact of magnetic activity on Gaia photometry.

2022-06-24
11:00
New insights on the formation of the terrestrial planets
Jingyi Mah (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
High-precision cosmochemistry data from meteorites suggest that the Earth, Mars and asteroid Vesta are compositionally distinct and that the compositions of these three objects appear to correlate with their distance from the Sun. These cosmochemistry observations can be used to constrain plausible formation pathways of the terrestrial planets in the inner Solar System. In particular, recent work has shown that aside from the classical view of collisions by increasingly massive planetesimals, the accretion of mm to m-sized pebbles can also reproduce the mass-orbit distribution of the terrestrial planets, igniting new debates in the community. In this talk I will discuss my work aiming to determine the more plausible formation pathway of the terrestrial planets by combining N-body simulations with constraints from cosmochemistry data.

2022-06-24
11:00
New insights on the formation of the terrestrial planets
Jingyi Mah (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
High-precision cosmochemistry data from meteorites suggest that the Earth, Mars and asteroid Vesta are compositionally distinct and that the compositions of these three objects appear to correlate with their distance from the Sun. These cosmochemistry observations can be used to constrain plausible formation pathways of the terrestrial planets in the inner Solar System. In particular, recent work has shown that aside from the classical view of collisions by increasingly massive planetesimals, the accretion of mm to m-sized pebbles can also reproduce the mass-orbit distribution of the terrestrial planets, igniting new debates in the community. In this talk I will discuss my work aiming to determine the more plausible formation pathway of the terrestrial planets by combining N-body simulations with constraints from cosmochemistry data.

2022-06-24
11:00
New insights on the formation of the terrestrial planets
Jingyi Mah (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
High-precision cosmochemistry data from meteorites suggest that the Earth, Mars and asteroid Vesta are compositionally distinct and that the compositions of these three objects appear to correlate with their distance from the Sun. These cosmochemistry observations can be used to constrain plausible formation pathways of the terrestrial planets in the inner Solar System. In particular, recent work has shown that aside from the classical view of collisions by increasingly massive planetesimals, the accretion of mm to m-sized pebbles can also reproduce the mass-orbit distribution of the terrestrial planets, igniting new debates in the community. In this talk I will discuss my work aiming to determine the more plausible formation pathway of the terrestrial planets by combining N-body simulations with constraints from cosmochemistry data.

2022-06-24
11:00
New insights on the formation of the terrestrial planets
Jingyi Mah (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
High-precision cosmochemistry data from meteorites suggest that the Earth, Mars and asteroid Vesta are compositionally distinct and that the compositions of these three objects appear to correlate with their distance from the Sun. These cosmochemistry observations can be used to constrain plausible formation pathways of the terrestrial planets in the inner Solar System. In particular, recent work has shown that aside from the classical view of collisions by increasingly massive planetesimals, the accretion of mm to m-sized pebbles can also reproduce the mass-orbit distribution of the terrestrial planets, igniting new debates in the community. In this talk I will discuss my work aiming to determine the more plausible formation pathway of the terrestrial planets by combining N-body simulations with constraints from cosmochemistry data.

2022-06-17
11:00
TBA
Anders Johansen (The Globe Institute, Copenhagen)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBA

2022-06-17
11:00
3D magneto-hydrodynamical model atmospheres: the influence of surface magnetism on the center-to-limb variation of solar-type stars
Hans-Günter Ludwig (LSW)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2022-06-17
11:00
Quasars and the intergalactic medium at cosmic dawn
Xiaohui Fan (University of Arizona)
Königstuhl Kolloquium
MPIA lecture hall,
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Abstract
High-redshift quasars provide direct probes to the formation of the earliest supermassive black holes, their connections to early galaxy formation, and the history of cosmic reionization. More than 200 quasars have now been discovered in the first billion years of the cosmic history, with the highest redshift currently at z=7.6, indicating that billion solar mass black holes have already fully formed merely half billion years after the first star formation in the universe. I will (1) review the current state of high-redshift quasar surveys and discoveries, as a result of the new generations of wide-field sky surveys and developments in data mining and machine learning\; (2) discuss using high-redshift quasars as probes to the history of supermassive black hole growth in the early universe, using measurements of quasar luminosity function and black hole masses\; (3) present the latest observations of the the co-evolution of early SMBH growth and galaxy formation, and the roles quasar played in early galaxy formation and structure formation\; and (4) review the progress of using IGM absorption in quasar sightlines and properties of quasar proximity zones, which is unveiling a rapid and highly inhomogeneous reionization process at z~5.5 - 7.5. I will close with a discussion about the future of high-redshift quasar research, in the context of facilities such as JWST, LSST and Roman Space Telescope.

2022-06-17
11:00
Quasars and the intergalactic medium at cosmic dawn
Xiaohui Fan (University of Arizona)
Königstuhl Kolloquium
MPIA lecture hall,
Show/hide abstract

Abstract
High-redshift quasars provide direct probes to the formation of the earliest supermassive black holes, their connections to early galaxy formation, and the history of cosmic reionization. More than 200 quasars have now been discovered in the first billion years of the cosmic history, with the highest redshift currently at z=7.6, indicating that billion solar mass black holes have already fully formed merely half billion years after the first star formation in the universe. I will (1) review the current state of high-redshift quasar surveys and discoveries, as a result of the new generations of wide-field sky surveys and developments in data mining and machine learning\; (2) discuss using high-redshift quasars as probes to the history of supermassive black hole growth in the early universe, using measurements of quasar luminosity function and black hole masses\; (3) present the latest observations of the the co-evolution of early SMBH growth and galaxy formation, and the roles quasar played in early galaxy formation and structure formation\; and (4) review the progress of using IGM absorption in quasar sightlines and properties of quasar proximity zones, which is unveiling a rapid and highly inhomogeneous reionization process at z~5.5 - 7.5. I will close with a discussion about the future of high-redshift quasar research, in the context of facilities such as JWST, LSST and Roman Space Telescope.

2022-06-17
11:00
Quasars and the intergalactic medium at cosmic dawn
Xiaohui Fan (University of Arizona)
Königstuhl Kolloquium
MPIA lecture hall,
Show/hide abstract

Abstract
High-redshift quasars provide direct probes to the formation of the earliest supermassive black holes, their connections to early galaxy formation, and the history of cosmic reionization. More than 200 quasars have now been discovered in the first billion years of the cosmic history, with the highest redshift currently at z=7.6, indicating that billion solar mass black holes have already fully formed merely half billion years after the first star formation in the universe. I will (1) review the current state of high-redshift quasar surveys and discoveries, as a result of the new generations of wide-field sky surveys and developments in data mining and machine learning\; (2) discuss using high-redshift quasars as probes to the history of supermassive black hole growth in the early universe, using measurements of quasar luminosity function and black hole masses\; (3) present the latest observations of the the co-evolution of early SMBH growth and galaxy formation, and the roles quasar played in early galaxy formation and structure formation\; and (4) review the progress of using IGM absorption in quasar sightlines and properties of quasar proximity zones, which is unveiling a rapid and highly inhomogeneous reionization process at z~5.5 - 7.5. I will close with a discussion about the future of high-redshift quasar research, in the context of facilities such as JWST, LSST and Roman Space Telescope.

2022-06-17
11:00
Quasars and the intergalactic medium at cosmic dawn
Xiaohui Fan (University of Arizona)
Königstuhl Kolloquium
MPIA lecture hall,
Show/hide abstract

Abstract
High-redshift quasars provide direct probes to the formation of the earliest supermassive black holes, their connections to early galaxy formation, and the history of cosmic reionization. More than 200 quasars have now been discovered in the first billion years of the cosmic history, with the highest redshift currently at z=7.6, indicating that billion solar mass black holes have already fully formed merely half billion years after the first star formation in the universe. I will (1) review the current state of high-redshift quasar surveys and discoveries, as a result of the new generations of wide-field sky surveys and developments in data mining and machine learning\; (2) discuss using high-redshift quasars as probes to the history of supermassive black hole growth in the early universe, using measurements of quasar luminosity function and black hole masses\; (3) present the latest observations of the the co-evolution of early SMBH growth and galaxy formation, and the roles quasar played in early galaxy formation and structure formation\; and (4) review the progress of using IGM absorption in quasar sightlines and properties of quasar proximity zones, which is unveiling a rapid and highly inhomogeneous reionization process at z~5.5 - 7.5. I will close with a discussion about the future of high-redshift quasar research, in the context of facilities such as JWST, LSST and Roman Space Telescope.

2022-06-10
11:00
Gaia Data Release 3
Coryn Bailer-Jones (MPIA)
Königstuhl Kolloquium
MPIA lecture hall,
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Abstract
Gaia Data Release 3 will take place on Monday 13 June. This is the second part of the third release, following on from the release of the main astrometry and photometry in December 2020. I will give an overview of what is new in this release and what to expect. All of the MPIA-Gaia team will be on hand to answer your questions, although answers to some will no doubt have to wait until Monday.

2022-06-10
11:00
Gaia Data Release 3
Coryn Bailer-Jones (MPIA)
Königstuhl Kolloquium
MPIA lecture hall,
Show/hide abstract

Abstract
Gaia Data Release 3 will take place on Monday 13 June. This is the second part of the third release, following on from the release of the main astrometry and photometry in December 2020. I will give an overview of what is new in this release and what to expect. All of the MPIA-Gaia team will be on hand to answer your questions, although answers to some will no doubt have to wait until Monday.

2022-06-10
11:00
Gaia Data Release 3
Coryn Bailer-Jones (MPIA)
Königstuhl Kolloquium
MPIA lecture hall,
Show/hide abstract

Abstract
Gaia Data Release 3 will take place on Monday 13 June. This is the second part of the third release, following on from the release of the main astrometry and photometry in December 2020. I will give an overview of what is new in this release and what to expect. All of the MPIA-Gaia team will be on hand to answer your questions, although answers to some will no doubt have to wait until Monday.

2022-06-10
11:00
Gaia Data Release 3
Coryn Bailer-Jones (MPIA)
Königstuhl Kolloquium
MPIA lecture hall,
Show/hide abstract

Abstract
Gaia Data Release 3 will take place on Monday 13 June. This is the second part of the third release, following on from the release of the main astrometry and photometry in December 2020. I will give an overview of what is new in this release and what to expect. All of the MPIA-Gaia team will be on hand to answer your questions, although answers to some will no doubt have to wait until Monday.

2022-06-03
11:00
From Planet-forming Disks to
Ilaria Pascucci (LPL, Tuscon)
Königstuhl Kolloquium
MPIA lecture hall,
Show/hide abstract

Abstract
How did our Solar System and other planet systems form? Which systems are most likely to host habitable worlds? These are critical questions as we plan for missions capable of detecting Earth analogues and search for atmospheric signatures of life. I will discuss how linking multi-wavelength observations of disks around young stars and exoplanet demographics sheds light on these questions. First, I will present evidence for a dominant mechanism to form giant planets. Then, I will discuss an ongoing effort to constrain how the most common planets, sub-Neptunes and super-Earths, form. I will conclude by discussing how upcoming facilities will further these studies and their role in reconstructing the paths to habitable worlds.

2022-06-03
11:00
From Planet-forming Disks to
Ilaria Pascucci (LPL, Tuscon)
Königstuhl Kolloquium
MPIA lecture hall,
Show/hide abstract

Abstract
How did our Solar System and other planet systems form? Which systems are most likely to host habitable worlds? These are critical questions as we plan for missions capable of detecting Earth analogues and search for atmospheric signatures of life. I will discuss how linking multi-wavelength observations of disks around young stars and exoplanet demographics sheds light on these questions. First, I will present evidence for a dominant mechanism to form giant planets. Then, I will discuss an ongoing effort to constrain how the most common planets, sub-Neptunes and super-Earths, form. I will conclude by discussing how upcoming facilities will further these studies and their role in reconstructing the paths to habitable worlds.

2022-06-03
11:00
From Planet-forming Disks to
Ilaria Pascucci (LPL, Tuscon)
Königstuhl Kolloquium
MPIA lecture hall,
Show/hide abstract

Abstract
How did our Solar System and other planet systems form? Which systems are most likely to host habitable worlds? These are critical questions as we plan for missions capable of detecting Earth analogues and search for atmospheric signatures of life. I will discuss how linking multi-wavelength observations of disks around young stars and exoplanet demographics sheds light on these questions. First, I will present evidence for a dominant mechanism to form giant planets. Then, I will discuss an ongoing effort to constrain how the most common planets, sub-Neptunes and super-Earths, form. I will conclude by discussing how upcoming facilities will further these studies and their role in reconstructing the paths to habitable worlds.

2022-06-03
11:00
TBD
Ilaria Pascucci (LPL, Tuscon)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
TBD

2022-06-03
11:00
From Planet-forming Disks to
Ilaria Pascucci (LPL, Tuscon)
Königstuhl Kolloquium
MPIA lecture hall,
Show/hide abstract

Abstract
How did our Solar System and other planet systems form? Which systems are most likely to host habitable worlds? These are critical questions as we plan for missions capable of detecting Earth analogues and search for atmospheric signatures of life. I will discuss how linking multi-wavelength observations of disks around young stars and exoplanet demographics sheds light on these questions. First, I will present evidence for a dominant mechanism to form giant planets. Then, I will discuss an ongoing effort to constrain how the most common planets, sub-Neptunes and super-Earths, form. I will conclude by discussing how upcoming facilities will further these studies and their role in reconstructing the paths to habitable worlds.

2022-05-27
11:00
TBA
Jennifer (Leigh) Wojno (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
TBA

2022-05-27
11:00
On Modelling Complex Systems in Astronomy
Yuan-Sen Ting (ANU)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Astronomy today is fundamentally different than it was even just a decade ago. Our increasing ability to collect a large amount of data from ever more powerful instrumental has enabled many new opportunities. However, such opportunity also comes with new challenges. The bottleneck stems from the fact that most astronomical observations are inherently high dimension — from “imaging” the Universe at the finest details to fully characterising tens of millions of spectra consisting of tens of thousands of wavelength pixels. In this regime, classical astrostatistics approaches struggle.

I will present two different machine learning approaches to quantify complex systems in astronomy. (1) Reductionist approach: I will discuss how machine learning can optimally compress information and extract higher-order moment information in stochastic processes. (2) A generative approach: I will discuss how generative models, such as normalising flow, allow us to properly model the vast astronomy data set, enabling the study of complex astronomy systems directly in their raw dimensional space.

2022-05-27
11:00
On Modelling Complex Systems in Astronomy
Yuan-Sen Ting (ANU)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Astronomy today is fundamentally different than it was even just a decade ago. Our increasing ability to collect a large amount of data from ever more powerful instrumental has enabled many new opportunities. However, such opportunity also comes with new challenges. The bottleneck stems from the fact that most astronomical observations are inherently high dimension — from “imaging” the Universe at the finest details to fully characterising tens of millions of spectra consisting of tens of thousands of wavelength pixels. In this regime, classical astrostatistics approaches struggle.

I will present two different machine learning approaches to quantify complex systems in astronomy. (1) Reductionist approach: I will discuss how machine learning can optimally compress information and extract higher-order moment information in stochastic processes. (2) A generative approach: I will discuss how generative models, such as normalising flow, allow us to properly model the vast astronomy data set, enabling the study of complex astronomy systems directly in their raw dimensional space.

2022-05-27
11:00
On Modelling Complex Systems in Astronomy
Yuan-Sen Ting (ANU)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Astronomy today is fundamentally different than it was even just a decade ago. Our increasing ability to collect a large amount of data from ever more powerful instrumental has enabled many new opportunities. However, such opportunity also comes with new challenges. The bottleneck stems from the fact that most astronomical observations are inherently high dimension — from “imaging” the Universe at the finest details to fully characterising tens of millions of spectra consisting of tens of thousands of wavelength pixels. In this regime, classical astrostatistics approaches struggle.

I will present two different machine learning approaches to quantify complex systems in astronomy. (1) Reductionist approach: I will discuss how machine learning can optimally compress information and extract higher-order moment information in stochastic processes. (2) A generative approach: I will discuss how generative models, such as normalising flow, allow us to properly model the vast astronomy data set, enabling the study of complex astronomy systems directly in their raw dimensional space.

2022-05-27
11:00
On Modelling Complex Systems in Astronomy
Yuan-Sen Ting (ANU)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Astronomy today is fundamentally different than it was even just a decade ago. Our increasing ability to collect a large amount of data from ever more powerful instrumental has enabled many new opportunities. However, such opportunity also comes with new challenges. The bottleneck stems from the fact that most astronomical observations are inherently high dimension — from “imaging” the Universe at the finest details to fully characterising tens of millions of spectra consisting of tens of thousands of wavelength pixels. In this regime, classical astrostatistics approaches struggle.

I will present two different machine learning approaches to quantify complex systems in astronomy. (1) Reductionist approach: I will discuss how machine learning can optimally compress information and extract higher-order moment information in stochastic processes. (2) A generative approach: I will discuss how generative models, such as normalising flow, allow us to properly model the vast astronomy data set, enabling the study of complex astronomy systems directly in their raw dimensional space.

2022-05-20
11:00
High contrast detection and characterization of exoplanets using high resolution spectroscopy
Dimitri Mawet (Caltech)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Twenty-seven years after the discovery of the first planet orbiting a star other than the Sun, it is now clear that extrasolar planets are ubiquitous in the galaxy. Though our understanding of exoplanet demographics has dramatically expanded in recent years, many fundamental questions about their origin and composition remain. High-precision high-resolution spectroscopy (HRS) at the diffraction limit of large telescopes enables the most detailed measurements of exoplanet properties, including their atmospheric composition and dynamics, orbits, and masses. I will present recent results obtained with the Keck Planet Imager and Characterizer (KPIC) at W.M. Keck Observatory as well as prospects for revolutionary advances in exoplanet detection and characterization with future ground- and space-based facilities.

2022-05-20
11:00
High contrast detection and characterization of exoplanets using high resolution spectroscopy
Dimitri Mawet (Caltech)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Twenty-seven years after the discovery of the first planet orbiting a star other than the Sun, it is now clear that extrasolar planets are ubiquitous in the galaxy. Though our understanding of exoplanet demographics has dramatically expanded in recent years, many fundamental questions about their origin and composition remain. High-precision high-resolution spectroscopy (HRS) at the diffraction limit of large telescopes enables the most detailed measurements of exoplanet properties, including their atmospheric composition and dynamics, orbits, and masses. I will present recent results obtained with the Keck Planet Imager and Characterizer (KPIC) at W.M. Keck Observatory as well as prospects for revolutionary advances in exoplanet detection and characterization with future ground- and space-based facilities.

2022-05-20
11:00
High contrast detection and characterization of exoplanets using high resolution spectroscopy
Dimitri Mawet (Caltech)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Twenty-seven years after the discovery of the first planet orbiting a star other than the Sun, it is now clear that extrasolar planets are ubiquitous in the galaxy. Though our understanding of exoplanet demographics has dramatically expanded in recent years, many fundamental questions about their origin and composition remain. High-precision high-resolution spectroscopy (HRS) at the diffraction limit of large telescopes enables the most detailed measurements of exoplanet properties, including their atmospheric composition and dynamics, orbits, and masses. I will present recent results obtained with the Keck Planet Imager and Characterizer (KPIC) at W.M. Keck Observatory as well as prospects for revolutionary advances in exoplanet detection and characterization with future ground- and space-based facilities.

2022-05-20
11:00
High contrast detection and characterization of exoplanets using high resolution spectroscopy
Dimitri Mawet (Caltech)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Twenty-seven years after the discovery of the first planet orbiting a star other than the Sun, it is now clear that extrasolar planets are ubiquitous in the galaxy. Though our understanding of exoplanet demographics has dramatically expanded in recent years, many fundamental questions about their origin and composition remain. High-precision high-resolution spectroscopy (HRS) at the diffraction limit of large telescopes enables the most detailed measurements of exoplanet properties, including their atmospheric composition and dynamics, orbits, and masses. I will present recent results obtained with the Keck Planet Imager and Characterizer (KPIC) at W.M. Keck Observatory as well as prospects for revolutionary advances in exoplanet detection and characterization with future ground- and space-based facilities.

2022-05-13
11:00
Three Years of Research of the Planet Genesis Group at MPIA
Paola Pinilla (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Since the first high angular resolution observation of a protoplanetary disk using ALMA eight years ago, our understanding of the structure and evolution of protoplanetary disks has been revolutionized. Ever since then, hundreds of disks have been observed with ALMA and SPHERE/VLT at high angular resolution, and they have been found in disks with different properties (for example: age, stellar mass). Disk substructures are key for planet formation: as dust traps, they are the regions where pebbles and planetesimals form. Although disk substructures have been detected is several protoplanetary disks, their origin, evolution, and properties remain unknown. The “Genesis of Planets” group at MPIA have been investigated the potential origin of these substructures, how can we observationally distinguish different origins, the effect of the stellar properties and disk environment, among others. In this colloquium, I will summarize the main results of the last three years of my group research and I will give a short overview of the near future in this field.

2022-05-13
11:00
Three Years of Research of the Planet Genesis Group at MPIA
Paola Pinilla (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Since the first high angular resolution observation of a protoplanetary disk using ALMA eight years ago, our understanding of the structure and evolution of protoplanetary disks has been revolutionized. Ever since then, hundreds of disks have been observed with ALMA and SPHERE/VLT at high angular resolution, and they have been found in disks with different properties (for example: age, stellar mass). Disk substructures are key for planet formation: as dust traps, they are the regions where pebbles and planetesimals form. Although disk substructures have been detected is several protoplanetary disks, their origin, evolution, and properties remain unknown. The “Genesis of Planets” group at MPIA have been investigated the potential origin of these substructures, how can we observationally distinguish different origins, the effect of the stellar properties and disk environment, among others. In this colloquium, I will summarize the main results of the last three years of my group research and I will give a short overview of the near future in this field.

2022-05-13
11:00
Three Years of Research of the Planet Genesis Group at MPIA
Paola Pinilla (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Since the first high angular resolution observation of a protoplanetary disk using ALMA eight years ago, our understanding of the structure and evolution of protoplanetary disks has been revolutionized. Ever since then, hundreds of disks have been observed with ALMA and SPHERE/VLT at high angular resolution, and they have been found in disks with different properties (for example: age, stellar mass). Disk substructures are key for planet formation: as dust traps, they are the regions where pebbles and planetesimals form. Although disk substructures have been detected is several protoplanetary disks, their origin, evolution, and properties remain unknown. The “Genesis of Planets” group at MPIA have been investigated the potential origin of these substructures, how can we observationally distinguish different origins, the effect of the stellar properties and disk environment, among others. In this colloquium, I will summarize the main results of the last three years of my group research and I will give a short overview of the near future in this field.

2022-05-13
11:00
Three Years of Research of the Planet Genesis Group at MPIA
Paola Pinilla (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Since the first high angular resolution observation of a protoplanetary disk using ALMA eight years ago, our understanding of the structure and evolution of protoplanetary disks has been revolutionized. Ever since then, hundreds of disks have been observed with ALMA and SPHERE/VLT at high angular resolution, and they have been found in disks with different properties (for example: age, stellar mass). Disk substructures are key for planet formation: as dust traps, they are the regions where pebbles and planetesimals form. Although disk substructures have been detected is several protoplanetary disks, their origin, evolution, and properties remain unknown. The “Genesis of Planets” group at MPIA have been investigated the potential origin of these substructures, how can we observationally distinguish different origins, the effect of the stellar properties and disk environment, among others. In this colloquium, I will summarize the main results of the last three years of my group research and I will give a short overview of the near future in this field.

2022-05-06
11:00
TBA
Michael Küffmeier (University of Virginia/MPE)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
TBA

2022-05-06
11:00
The Pristine survey: Galactic Archaeology with the very metal-poor (and very old) Milky Way
Nicolas Martin (Obs. Strasbourg)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
I will present the latest results from the Pristine collaboration that builds on a large photometric survey of the Northern sky with a narrow-band filter that focuses on the metallicity-sensitive Ca H&K lines and that yields accurate metallicities for tens of millions of stars. I will show that Pristine is very efficient at finding extremely metal-poor stars ([Fe/H]<-3.0 dex), whose chemistry holds information about the very first stars\; that we are starting to lift the veil on the distribution and, when combined with the exquisite Gaia astrometric information, the orbits of these oldest stars in the Milky Way and in dwarf galaxies\; and that, with the advent of near-future, large spectroscopic surveys like WEAVE, we shall soon have an unprecedented view of the assembly of the Milky Way at the earliest times.

2022-05-06
11:00
The Pristine survey: Galactic Archaeology with the very metal-poor (and very old) Milky Way
Nicolas Martin (Obs. Strasbourg)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
I will present the latest results from the Pristine collaboration that builds on a large photometric survey of the Northern sky with a narrow-band filter that focuses on the metallicity-sensitive Ca H&K lines and that yields accurate metallicities for tens of millions of stars. I will show that Pristine is very efficient at finding extremely metal-poor stars ([Fe/H]<-3.0 dex), whose chemistry holds information about the very first stars\; that we are starting to lift the veil on the distribution and, when combined with the exquisite Gaia astrometric information, the orbits of these oldest stars in the Milky Way and in dwarf galaxies\; and that, with the advent of near-future, large spectroscopic surveys like WEAVE, we shall soon have an unprecedented view of the assembly of the Milky Way at the earliest times.

2022-05-06
11:00
The Pristine survey: Galactic Archaeology with the very metal-poor (and very old) Milky Way
Nicolas Martin (Obs. Strasbourg)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
I will present the latest results from the Pristine collaboration that builds on a large photometric survey of the Northern sky with a narrow-band filter that focuses on the metallicity-sensitive Ca H&K lines and that yields accurate metallicities for tens of millions of stars. I will show that Pristine is very efficient at finding extremely metal-poor stars ([Fe/H]<-3.0 dex), whose chemistry holds information about the very first stars\; that we are starting to lift the veil on the distribution and, when combined with the exquisite Gaia astrometric information, the orbits of these oldest stars in the Milky Way and in dwarf galaxies\; and that, with the advent of near-future, large spectroscopic surveys like WEAVE, we shall soon have an unprecedented view of the assembly of the Milky Way at the earliest times.

2022-05-06
11:00
The Pristine survey: Galactic Archaeology with the very metal-poor (and very old) Milky Way
Nicolas Martin (Obs. Strasbourg)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
I will present the latest results from the Pristine collaboration that builds on a large photometric survey of the Northern sky with a narrow-band filter that focuses on the metallicity-sensitive Ca H&K lines and that yields accurate metallicities for tens of millions of stars. I will show that Pristine is very efficient at finding extremely metal-poor stars ([Fe/H]<-3.0 dex), whose chemistry holds information about the very first stars\; that we are starting to lift the veil on the distribution and, when combined with the exquisite Gaia astrometric information, the orbits of these oldest stars in the Milky Way and in dwarf galaxies\; and that, with the advent of near-future, large spectroscopic surveys like WEAVE, we shall soon have an unprecedented view of the assembly of the Milky Way at the earliest times.

2022-04-29
11:00
Active Galactic Nuclei on the Smallest Scales: Imaging the Circumnuclear Dust with MATISSE
Jacob Isbell (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Active galactic nuclei (AGN) play a key role in galaxy formation and evolution, but they remain shrouded in dust and in mystery. The dust surrounding the AGN on parsec scales traces the molecular gas responsible for AGN feeding, causes the diversity of AGN types, and may be an important channel for interaction with the host galaxy. The small physical scales of the dust structures means that the so-called "torus" remains unresolved with 10m-class telescopes, and instead we use the mid-infrared interferometer, VLTI MATISSE, to study a small number of nearby Seyfert AGN. The Circinus Galaxy is the nearest Seyfert 2, and using MATISSE we have imaged its circumnuclear dust for the first time. It is clear that a smooth torus is no longer a sufficient description of the dust. Instead we find a 1.9 pc diameter thin disk and patchy emission perpendicular to it. We find strong evidence of dust clumpiness and ~3pc scale warm dust emission consistent with radiation-driven outflow models. We also showed in imaging of NGC 1068 that the SMBH was obscured by a warm, nearly edge-on disk. We identified emission from polar flows and absorbing dust that is mineralogically distinct from standard ISM dust, indicating possible dust recycling. These results place new constraints on hydrodynamical and radiation transfer modeling, and have implications for the Unified Model of AGN.

2022-04-29
11:00
Active Galactic Nuclei on the Smallest Scales: Imaging the Circumnuclear Dust with MATISSE
Jacob Isbell (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Active galactic nuclei (AGN) play a key role in galaxy formation and evolution, but they remain shrouded in dust and in mystery. The dust surrounding the AGN on parsec scales traces the molecular gas responsible for AGN feeding, causes the diversity of AGN types, and may be an important channel for interaction with the host galaxy. The small physical scales of the dust structures means that the so-called "torus" remains unresolved with 10m-class telescopes, and instead we use the mid-infrared interferometer, VLTI MATISSE, to study a small number of nearby Seyfert AGN. The Circinus Galaxy is the nearest Seyfert 2, and using MATISSE we have imaged its circumnuclear dust for the first time. It is clear that a smooth torus is no longer a sufficient description of the dust. Instead we find a 1.9 pc diameter thin disk and patchy emission perpendicular to it. We find strong evidence of dust clumpiness and ~3pc scale warm dust emission consistent with radiation-driven outflow models. We also showed in imaging of NGC 1068 that the SMBH was obscured by a warm, nearly edge-on disk. We identified emission from polar flows and absorbing dust that is mineralogically distinct from standard ISM dust, indicating possible dust recycling. These results place new constraints on hydrodynamical and radiation transfer modeling, and have implications for the Unified Model of AGN.

2022-04-29
11:00
Active Galactic Nuclei on the Smallest Scales: Imaging the Circumnuclear Dust with MATISSE
Jacob Isbell (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Active galactic nuclei (AGN) play a key role in galaxy formation and evolution, but they remain shrouded in dust and in mystery. The dust surrounding the AGN on parsec scales traces the molecular gas responsible for AGN feeding, causes the diversity of AGN types, and may be an important channel for interaction with the host galaxy. The small physical scales of the dust structures means that the so-called "torus" remains unresolved with 10m-class telescopes, and instead we use the mid-infrared interferometer, VLTI MATISSE, to study a small number of nearby Seyfert AGN. The Circinus Galaxy is the nearest Seyfert 2, and using MATISSE we have imaged its circumnuclear dust for the first time. It is clear that a smooth torus is no longer a sufficient description of the dust. Instead we find a 1.9 pc diameter thin disk and patchy emission perpendicular to it. We find strong evidence of dust clumpiness and ~3pc scale warm dust emission consistent with radiation-driven outflow models. We also showed in imaging of NGC 1068 that the SMBH was obscured by a warm, nearly edge-on disk. We identified emission from polar flows and absorbing dust that is mineralogically distinct from standard ISM dust, indicating possible dust recycling. These results place new constraints on hydrodynamical and radiation transfer modeling, and have implications for the Unified Model of AGN.

2022-04-29
11:00
Active Galactic Nuclei on the Smallest Scales: Imaging the Circumnuclear Dust with MATISSE
Jacob Isbell (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Active galactic nuclei (AGN) play a key role in galaxy formation and evolution, but they remain shrouded in dust and in mystery. The dust surrounding the AGN on parsec scales traces the molecular gas responsible for AGN feeding, causes the diversity of AGN types, and may be an important channel for interaction with the host galaxy. The small physical scales of the dust structures means that the so-called "torus" remains unresolved with 10m-class telescopes, and instead we use the mid-infrared interferometer, VLTI MATISSE, to study a small number of nearby Seyfert AGN. The Circinus Galaxy is the nearest Seyfert 2, and using MATISSE we have imaged its circumnuclear dust for the first time. It is clear that a smooth torus is no longer a sufficient description of the dust. Instead we find a 1.9 pc diameter thin disk and patchy emission perpendicular to it. We find strong evidence of dust clumpiness and ~3pc scale warm dust emission consistent with radiation-driven outflow models. We also showed in imaging of NGC 1068 that the SMBH was obscured by a warm, nearly edge-on disk. We identified emission from polar flows and absorbing dust that is mineralogically distinct from standard ISM dust, indicating possible dust recycling. These results place new constraints on hydrodynamical and radiation transfer modeling, and have implications for the Unified Model of AGN.

2022-04-22
11:00
Classification of astronomical data using machine learning. An application to variable stars classification
Sara Jamal (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Large-scale surveys such as Gaia and the Rubin Observatory (LSST) raise the challenge of processing large data streams to identify more than 10^6 sources, thus supporting the use of automated approaches such as ML for classification tasks and outlier detection. In this context, the performances of ML techniques (e.g., neural networks) have been demonstrated over the last years in a broad range of applications such as supernovae classification, transient events detection and, more generally, VS classification.
Stellar variability manifests through changes over time in the chemical composition, the brightness and the color of a star depending on its evolutionary stage and environment (e.g. multiple system, accretion). The classification of VS is based on the taxonomy defined by the GCVS and exploits data observed over time across different photometric bands.
The first part of this talk aims to briefly present the general context supporting the use of ML for astronomical data classification, with an emphasis on VS. The second part of this talk presents my previous work on VS classification using deep neural networks, and introduces the ongoing developments of the ML classification module, DSC, for Gaia. Finally, I will close with a discussion on current limitations and outlooks regarding the use of ML for classification in astronomy.

2022-04-22
11:00
Classification of astronomical data using machine learning. An application to variable stars classification
Sara Jamal (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Large-scale surveys such as Gaia and the Rubin Observatory (LSST) raise the challenge of processing large data streams to identify more than 10^6 sources, thus supporting the use of automated approaches such as ML for classification tasks and outlier detection. In this context, the performances of ML techniques (e.g., neural networks) have been demonstrated over the last years in a broad range of applications such as supernovae classification, transient events detection and, more generally, VS classification.
Stellar variability manifests through changes over time in the chemical composition, the brightness and the color of a star depending on its evolutionary stage and environment (e.g. multiple system, accretion). The classification of VS is based on the taxonomy defined by the GCVS and exploits data observed over time across different photometric bands.
The first part of this talk aims to briefly present the general context supporting the use of ML for astronomical data classification, with an emphasis on VS. The second part of this talk presents my previous work on VS classification using deep neural networks, and introduces the ongoing developments of the ML classification module, DSC, for Gaia. Finally, I will close with a discussion on current limitations and outlooks regarding the use of ML for classification in astronomy.

2022-04-22
11:00
Classification of astronomical data using machine learning. An application to variable stars classification
Sara Jamal (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Large-scale surveys such as Gaia and the Rubin Observatory (LSST) raise the challenge of processing large data streams to identify more than 10^6 sources, thus supporting the use of automated approaches such as ML for classification tasks and outlier detection. In this context, the performances of ML techniques (e.g., neural networks) have been demonstrated over the last years in a broad range of applications such as supernovae classification, transient events detection and, more generally, VS classification.
Stellar variability manifests through changes over time in the chemical composition, the brightness and the color of a star depending on its evolutionary stage and environment (e.g. multiple system, accretion). The classification of VS is based on the taxonomy defined by the GCVS and exploits data observed over time across different photometric bands.
The first part of this talk aims to briefly present the general context supporting the use of ML for astronomical data classification, with an emphasis on VS. The second part of this talk presents my previous work on VS classification using deep neural networks, and introduces the ongoing developments of the ML classification module, DSC, for Gaia. Finally, I will close with a discussion on current limitations and outlooks regarding the use of ML for classification in astronomy.

2022-04-22
11:00
Classification of astronomical data using machine learning. An application to variable stars classification
Sara Jamal (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Large-scale surveys such as Gaia and the Rubin Observatory (LSST) raise the challenge of processing large data streams to identify more than 10^6 sources, thus supporting the use of automated approaches such as ML for classification tasks and outlier detection. In this context, the performances of ML techniques (e.g., neural networks) have been demonstrated over the last years in a broad range of applications such as supernovae classification, transient events detection and, more generally, VS classification.
Stellar variability manifests through changes over time in the chemical composition, the brightness and the color of a star depending on its evolutionary stage and environment (e.g. multiple system, accretion). The classification of VS is based on the taxonomy defined by the GCVS and exploits data observed over time across different photometric bands.
The first part of this talk aims to briefly present the general context supporting the use of ML for astronomical data classification, with an emphasis on VS. The second part of this talk presents my previous work on VS classification using deep neural networks, and introduces the ongoing developments of the ML classification module, DSC, for Gaia. Finally, I will close with a discussion on current limitations and outlooks regarding the use of ML for classification in astronomy.

2022-04-15
11:00
No KoCo
Public Holiday
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2022-04-15
11:00
No KoCo
Public Holiday
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2022-04-15
11:00
No KoCo
Public Holiday
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2022-04-15
11:00
No KoCo
Public Holiday
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2022-04-08
11:00
Unveiling the early stages of planet formation
Myriam Benisty (IPAG)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The exoplanet population detected so far shows an extreme diversity that is still partly unexplained. It may originate from the diversity in the initial conditions and physical processes that lead to their formation in protoplanetary disks. Protoplanetary disks evolve and dissipate rapidly while planets are forming resulting in a complex interplay that can influence and determine the final outcome of the planet formation process. To address this major open question, it is crucial to directly observe young planets still in the process of formation, and their direct imprints on the disk structure.

In this talk, I will present recent high-resolution observations of protoplanetary disks, obtained at multiple wavelengths, that show that small scale structures are not only nearly ubiquitous in disks but that they can directly inform on the disk physical conditions, the underlying young planets population and the processes of planet formation. I will also discuss the exciting perspectives in this field, enabled by the development of new instrumentation.

2022-04-08
11:00
Unveiling the early stages of planet formation
Myriam Benisty (IPAG)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
The exoplanet population detected so far shows an extreme diversity that is still partly unexplained. It may originate from the diversity in the initial conditions and physical processes that lead to their formation in protoplanetary disks. Protoplanetary disks evolve and dissipate rapidly while planets are forming resulting in a complex interplay that can influence and determine the final outcome of the planet formation process. To address this major open question, it is crucial to directly observe young planets still in the process of formation, and their direct imprints on the disk structure.

In this talk, I will present recent high-resolution observations of protoplanetary disks, obtained at multiple wavelengths, that show that small scale structures are not only nearly ubiquitous in disks but that they can directly inform on the disk physical conditions, the underlying young planets population and the processes of planet formation. I will also discuss the exciting perspectives in this field, enabled by the development of new instrumentation.

2022-04-08
11:00
Unveiling the early stages of planet formation
Myriam Benisty (IPAG)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
The exoplanet population detected so far shows an extreme diversity that is still partly unexplained. It may originate from the diversity in the initial conditions and physical processes that lead to their formation in protoplanetary disks. Protoplanetary disks evolve and dissipate rapidly while planets are forming resulting in a complex interplay that can influence and determine the final outcome of the planet formation process. To address this major open question, it is crucial to directly observe young planets still in the process of formation, and their direct imprints on the disk structure.

In this talk, I will present recent high-resolution observations of protoplanetary disks, obtained at multiple wavelengths, that show that small scale structures are not only nearly ubiquitous in disks but that they can directly inform on the disk physical conditions, the underlying young planets population and the processes of planet formation. I will also discuss the exciting perspectives in this field, enabled by the development of new instrumentation.

2022-04-08
11:00
Unveiling the early stages of planet formation
Myriam Benisty (IPAG)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
The exoplanet population detected so far shows an extreme diversity that is still partly unexplained. It may originate from the diversity in the initial conditions and physical processes that lead to their formation in protoplanetary disks. Protoplanetary disks evolve and dissipate rapidly while planets are forming resulting in a complex interplay that can influence and determine the final outcome of the planet formation process. To address this major open question, it is crucial to directly observe young planets still in the process of formation, and their direct imprints on the disk structure.

In this talk, I will present recent high-resolution observations of protoplanetary disks, obtained at multiple wavelengths, that show that small scale structures are not only nearly ubiquitous in disks but that they can directly inform on the disk physical conditions, the underlying young planets population and the processes of planet formation. I will also discuss the exciting perspectives in this field, enabled by the development of new instrumentation.

2022-04-01
11:00
Warm giant exoplanets in the TESS era
Melissa Hobson (MPIA) : The WINE survey
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
In order to understand planet formation, evolution, and internal structure, we need a clear picture of exoplanet demographics. In particular, giant long-period exoplanets are fundamental, as -unlike the better-sampled Hot Jupiters - they preserve their formation history in their orbital parameters. Likewise, they do not suffer from irradiation-induced inflation as Hot Jupiters do, so their internal structure can be better modelled. The ongoing TESS mission has provided many warm giant candidates, which the Warm gIaNts with tEss collaboration (WINE) is at the forefront of detecting, confirming, and characterizing. Our systematic search for transits in the TESS light curves has given rise to hundreds of transiting giant candidates with periods larger than 10 days, out to hundreds of days. Our efficient ground-based radial-velocity and photometric follow-up of the southern skies has already confirmed several tens of these candidates. In this presentation, I will describe the survey, and present some of our most exciting recent discoveries, such as a still-cooling planet around a young, active star, and an exo-Saturn with a habitable-zone companion.

2022-04-01
11:00
Warm giant exoplanets in the TESS era
Melissa Hobson (MPIA) : The WINE survey
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
In order to understand planet formation, evolution, and internal structure, we need a clear picture of exoplanet demographics. In particular, giant long-period exoplanets are fundamental, as -unlike the better-sampled Hot Jupiters - they preserve their formation history in their orbital parameters. Likewise, they do not suffer from irradiation-induced inflation as Hot Jupiters do, so their internal structure can be better modelled. The ongoing TESS mission has provided many warm giant candidates, which the Warm gIaNts with tEss collaboration (WINE) is at the forefront of detecting, confirming, and characterizing. Our systematic search for transits in the TESS light curves has given rise to hundreds of transiting giant candidates with periods larger than 10 days, out to hundreds of days. Our efficient ground-based radial-velocity and photometric follow-up of the southern skies has already confirmed several tens of these candidates. In this presentation, I will describe the survey, and present some of our most exciting recent discoveries, such as a still-cooling planet around a young, active star, and an exo-Saturn with a habitable-zone companion.

2022-04-01
11:00
Warm giant exoplanets in the TESS era
Melissa Hobson (MPIA) : The WINE survey
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
In order to understand planet formation, evolution, and internal structure, we need a clear picture of exoplanet demographics. In particular, giant long-period exoplanets are fundamental, as -unlike the better-sampled Hot Jupiters - they preserve their formation history in their orbital parameters. Likewise, they do not suffer from irradiation-induced inflation as Hot Jupiters do, so their internal structure can be better modelled. The ongoing TESS mission has provided many warm giant candidates, which the Warm gIaNts with tEss collaboration (WINE) is at the forefront of detecting, confirming, and characterizing. Our systematic search for transits in the TESS light curves has given rise to hundreds of transiting giant candidates with periods larger than 10 days, out to hundreds of days. Our efficient ground-based radial-velocity and photometric follow-up of the southern skies has already confirmed several tens of these candidates. In this presentation, I will describe the survey, and present some of our most exciting recent discoveries, such as a still-cooling planet around a young, active star, and an exo-Saturn with a habitable-zone companion.

2022-04-01
11:00
Warm giant exoplanets in the TESS era
Melissa Hobson (MPIA) : The WINE survey
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
In order to understand planet formation, evolution, and internal structure, we need a clear picture of exoplanet demographics. In particular, giant long-period exoplanets are fundamental, as -unlike the better-sampled Hot Jupiters - they preserve their formation history in their orbital parameters. Likewise, they do not suffer from irradiation-induced inflation as Hot Jupiters do, so their internal structure can be better modelled. The ongoing TESS mission has provided many warm giant candidates, which the Warm gIaNts with tEss collaboration (WINE) is at the forefront of detecting, confirming, and characterizing. Our systematic search for transits in the TESS light curves has given rise to hundreds of transiting giant candidates with periods larger than 10 days, out to hundreds of days. Our efficient ground-based radial-velocity and photometric follow-up of the southern skies has already confirmed several tens of these candidates. In this presentation, I will describe the survey, and present some of our most exciting recent discoveries, such as a still-cooling planet around a young, active star, and an exo-Saturn with a habitable-zone companion.

2022-03-25
15:00
The interplay between internal and external processes in disk galaxies
Francesca Pinna (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Galactic internal structures are an important tracer of the global-galaxy formation and evolution. At larger scale, spatially resolved stellar populations of galactic disks tell us the story of spiral galaxies from the early stages when the older thick disks formed, to recent times when most thin disks were still forming stars. Thick disks, fainter envelopes of the brighter thin disks, are generally older and more metal-poor. Different formation scenarios have been proposed in the literature to explain their properties: in-situ formation at high redshift from turbulent gas, dynamical heating of a preexisting thinner disk and direct accretion of stars. I will present my work on this topic, making use of integral-field spectroscopy observations of edge-on galaxies as well as high-resolution numerical simulations. These results reveal complex thick-disk origins, combination of the different mechanisms that were previously proposed, and shed some light on the evolutionary connection between the thin and the thick disk. Their star-formation histories and chemical evolutions result from the interplay between internal and external processes. Galaxy mergers, providing both stars and gas from satellites, play an essential role in the formation and growth of galactic internal structures at different spatial scales, and are then key to understand the mass assembly of galaxies.

2022-03-25
15:00
The interplay between internal and external processes in disk galaxies
Francesca Pinna (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Galactic internal structures are an important tracer of the global-galaxy formation and evolution. At larger scale, spatially resolved stellar populations of galactic disks tell us the story of spiral galaxies from the early stages when the older thick disks formed, to recent times when most thin disks were still forming stars. Thick disks, fainter envelopes of the brighter thin disks, are generally older and more metal-poor. Different formation scenarios have been proposed in the literature to explain their properties: in-situ formation at high redshift from turbulent gas, dynamical heating of a preexisting thinner disk and direct accretion of stars. I will present my work on this topic, making use of integral-field spectroscopy observations of edge-on galaxies as well as high-resolution numerical simulations. These results reveal complex thick-disk origins, combination of the different mechanisms that were previously proposed, and shed some light on the evolutionary connection between the thin and the thick disk. Their star-formation histories and chemical evolutions result from the interplay between internal and external processes. Galaxy mergers, providing both stars and gas from satellites, play an essential role in the formation and growth of galactic internal structures at different spatial scales, and are then key to understand the mass assembly of galaxies.

2022-03-25
15:00
The interplay between internal and external processes in disk galaxies
Francesca Pinna (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Galactic internal structures are an important tracer of the global-galaxy formation and evolution. At larger scale, spatially resolved stellar populations of galactic disks tell us the story of spiral galaxies from the early stages when the older thick disks formed, to recent times when most thin disks were still forming stars. Thick disks, fainter envelopes of the brighter thin disks, are generally older and more metal-poor. Different formation scenarios have been proposed in the literature to explain their properties: in-situ formation at high redshift from turbulent gas, dynamical heating of a preexisting thinner disk and direct accretion of stars. I will present my work on this topic, making use of integral-field spectroscopy observations of edge-on galaxies as well as high-resolution numerical simulations. These results reveal complex thick-disk origins, combination of the different mechanisms that were previously proposed, and shed some light on the evolutionary connection between the thin and the thick disk. Their star-formation histories and chemical evolutions result from the interplay between internal and external processes. Galaxy mergers, providing both stars and gas from satellites, play an essential role in the formation and growth of galactic internal structures at different spatial scales, and are then key to understand the mass assembly of galaxies.

2022-03-25
15:00
The interplay between internal and external processes in disk galaxies
Francesca Pinna (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Galactic internal structures are an important tracer of the global-galaxy formation and evolution. At larger scale, spatially resolved stellar populations of galactic disks tell us the story of spiral galaxies from the early stages when the older thick disks formed, to recent times when most thin disks were still forming stars. Thick disks, fainter envelopes of the brighter thin disks, are generally older and more metal-poor. Different formation scenarios have been proposed in the literature to explain their properties: in-situ formation at high redshift from turbulent gas, dynamical heating of a preexisting thinner disk and direct accretion of stars. I will present my work on this topic, making use of integral-field spectroscopy observations of edge-on galaxies as well as high-resolution numerical simulations. These results reveal complex thick-disk origins, combination of the different mechanisms that were previously proposed, and shed some light on the evolutionary connection between the thin and the thick disk. Their star-formation histories and chemical evolutions result from the interplay between internal and external processes. Galaxy mergers, providing both stars and gas from satellites, play an essential role in the formation and growth of galactic internal structures at different spatial scales, and are then key to understand the mass assembly of galaxies.

2022-03-18
15:00
The cloud-scale baryon cycle across the nearby galaxy population
Melanie Chevance (ZAH/ARI)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Galaxies are in constant evolution, driven by the cycle of matter within them: gas clouds assemble and collapse, stars form within them, matter and energy are redistributed in the galaxy through stellar feedback and turbulence. The physical processes driving this cycle occur on small scales but govern the evolution of entire galaxies. In turn, the large-scale evolution of galaxies across space and time directly affects the environment from which stars form. It is one of the big unanswered questions in modern astrophysics which processes drive this multi-scale cycle and what its quantitative characteristics are. I will present the first systematic characterisation of the evolutionary timeline between molecular gas clouds, stars and feedback in galaxies. I will show that star formation is fast and inefficient: gas clouds are quickly destroyed (within 1-5 Myr) by radiation and winds from the young stars born within them, limiting the efficiency of the gas-to-star conversion to 2-10%. Such measurements are key to overcome the main limitation of current simulations of galaxy formation and evolution.

2022-03-18
15:00
The cloud-scale baryon cycle across the nearby galaxy population
Melanie Chevance (ZAH/ARI)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Galaxies are in constant evolution, driven by the cycle of matter within them: gas clouds assemble and collapse, stars form within them, matter and energy are redistributed in the galaxy through stellar feedback and turbulence. The physical processes driving this cycle occur on small scales but govern the evolution of entire galaxies. In turn, the large-scale evolution of galaxies across space and time directly affects the environment from which stars form. It is one of the big unanswered questions in modern astrophysics which processes drive this multi-scale cycle and what its quantitative characteristics are. I will present the first systematic characterisation of the evolutionary timeline between molecular gas clouds, stars and feedback in galaxies. I will show that star formation is fast and inefficient: gas clouds are quickly destroyed (within 1-5 Myr) by radiation and winds from the young stars born within them, limiting the efficiency of the gas-to-star conversion to 2-10%. Such measurements are key to overcome the main limitation of current simulations of galaxy formation and evolution.

2022-03-18
15:00
The cloud-scale baryon cycle across the nearby galaxy population
Melanie Chevance (ZAH/ARI)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Galaxies are in constant evolution, driven by the cycle of matter within them: gas clouds assemble and collapse, stars form within them, matter and energy are redistributed in the galaxy through stellar feedback and turbulence. The physical processes driving this cycle occur on small scales but govern the evolution of entire galaxies. In turn, the large-scale evolution of galaxies across space and time directly affects the environment from which stars form. It is one of the big unanswered questions in modern astrophysics which processes drive this multi-scale cycle and what its quantitative characteristics are. I will present the first systematic characterisation of the evolutionary timeline between molecular gas clouds, stars and feedback in galaxies. I will show that star formation is fast and inefficient: gas clouds are quickly destroyed (within 1-5 Myr) by radiation and winds from the young stars born within them, limiting the efficiency of the gas-to-star conversion to 2-10%. Such measurements are key to overcome the main limitation of current simulations of galaxy formation and evolution.

2022-03-18
15:00
The cloud-scale baryon cycle across the nearby galaxy population
Melanie Chevance (ZAH/ARI)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Galaxies are in constant evolution, driven by the cycle of matter within them: gas clouds assemble and collapse, stars form within them, matter and energy are redistributed in the galaxy through stellar feedback and turbulence. The physical processes driving this cycle occur on small scales but govern the evolution of entire galaxies. In turn, the large-scale evolution of galaxies across space and time directly affects the environment from which stars form. It is one of the big unanswered questions in modern astrophysics which processes drive this multi-scale cycle and what its quantitative characteristics are. I will present the first systematic characterisation of the evolutionary timeline between molecular gas clouds, stars and feedback in galaxies. I will show that star formation is fast and inefficient: gas clouds are quickly destroyed (within 1-5 Myr) by radiation and winds from the young stars born within them, limiting the efficiency of the gas-to-star conversion to 2-10%. Such measurements are key to overcome the main limitation of current simulations of galaxy formation and evolution.

2022-03-11
15:00
TBA
Francesca Pinna (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBA

2022-03-11
15:00
Insights into hot Jupiter atmospheres from 3D circulation models
Maria Steinrueck (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Out of all exoplanets, hot Jupiters are the most amenable to atmospheric characterization. To make sense of the growing body of observations and to better understand the atmospheres of these planets, three-dimensional models are crucial. The strong day-night temperature contrast on hot Jupiters drives a vigorous atmospheric circulation which can profoundly change atmospheric processes such as chemistry, cloud formation and haze formation. In turn, these processes have a feedback on the temperature structure and the winds. In this talk, I will highlight some examples of this interaction. First, I will talk about including disequilibrium abundances of the important infrared absorbers CH4 and CO in general circulation models (GCMs). My results show that disequilibrium CH4 and CO abundances significantly affect the thermal structure, predicted phase curves and emission spectra of hot Jupiters. I will then discuss photochemical hazes. Even though it is expected that photochemical hazes form on the daysides of many hot Jupiters, my work is the first to examine the detailed 3D distribution of photochemical hazes. I will present results on the effect of the inhomogeneous haze distribution on transmission spectra as well as how heating and cooling from hazes changes the global temperature structure and atmospheric circulation.

2022-03-11
15:00
Insights into hot Jupiter atmospheres from 3D circulation models
Maria Steinrueck (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Out of all exoplanets, hot Jupiters are the most amenable to atmospheric characterization. To make sense of the growing body of observations and to better understand the atmospheres of these planets, three-dimensional models are crucial. The strong day-night temperature contrast on hot Jupiters drives a vigorous atmospheric circulation which can profoundly change atmospheric processes such as chemistry, cloud formation and haze formation. In turn, these processes have a feedback on the temperature structure and the winds. In this talk, I will highlight some examples of this interaction. First, I will talk about including disequilibrium abundances of the important infrared absorbers CH4 and CO in general circulation models (GCMs). My results show that disequilibrium CH4 and CO abundances significantly affect the thermal structure, predicted phase curves and emission spectra of hot Jupiters. I will then discuss photochemical hazes. Even though it is expected that photochemical hazes form on the daysides of many hot Jupiters, my work is the first to examine the detailed 3D distribution of photochemical hazes. I will present results on the effect of the inhomogeneous haze distribution on transmission spectra as well as how heating and cooling from hazes changes the global temperature structure and atmospheric circulation.

2022-03-11
15:00
Insights into hot Jupiter atmospheres from 3D circulation models
Maria Steinrueck (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Out of all exoplanets, hot Jupiters are the most amenable to atmospheric characterization. To make sense of the growing body of observations and to better understand the atmospheres of these planets, three-dimensional models are crucial. The strong day-night temperature contrast on hot Jupiters drives a vigorous atmospheric circulation which can profoundly change atmospheric processes such as chemistry, cloud formation and haze formation. In turn, these processes have a feedback on the temperature structure and the winds. In this talk, I will highlight some examples of this interaction. First, I will talk about including disequilibrium abundances of the important infrared absorbers CH4 and CO in general circulation models (GCMs). My results show that disequilibrium CH4 and CO abundances significantly affect the thermal structure, predicted phase curves and emission spectra of hot Jupiters. I will then discuss photochemical hazes. Even though it is expected that photochemical hazes form on the daysides of many hot Jupiters, my work is the first to examine the detailed 3D distribution of photochemical hazes. I will present results on the effect of the inhomogeneous haze distribution on transmission spectra as well as how heating and cooling from hazes changes the global temperature structure and atmospheric circulation.

2022-03-11
15:00
Insights into hot Jupiter atmospheres from 3D circulation models
Maria Steinrueck (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Out of all exoplanets, hot Jupiters are the most amenable to atmospheric characterization. To make sense of the growing body of observations and to better understand the atmospheres of these planets, three-dimensional models are crucial. The strong day-night temperature contrast on hot Jupiters drives a vigorous atmospheric circulation which can profoundly change atmospheric processes such as chemistry, cloud formation and haze formation. In turn, these processes have a feedback on the temperature structure and the winds. In this talk, I will highlight some examples of this interaction. First, I will talk about including disequilibrium abundances of the important infrared absorbers CH4 and CO in general circulation models (GCMs). My results show that disequilibrium CH4 and CO abundances significantly affect the thermal structure, predicted phase curves and emission spectra of hot Jupiters. I will then discuss photochemical hazes. Even though it is expected that photochemical hazes form on the daysides of many hot Jupiters, my work is the first to examine the detailed 3D distribution of photochemical hazes. I will present results on the effect of the inhomogeneous haze distribution on transmission spectra as well as how heating and cooling from hazes changes the global temperature structure and atmospheric circulation.

2022-03-04
15:00
Data Science at MPIA
Iva Momcheva & Morgan Fouesneau
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
We present the newly created Data Science department at MPIA. We will first give you an overview of what means data science means in the astronomy context and present our activity plans for 2022. The department will support everyone in carrying out novel, cutting-edge research and establishing MPIA as a worldwide leader in astronomical data science by providing a platform to solidify foundational hacking & coding skills, a space to explore. develop, and share data science skills.

2022-03-04
15:00
Data Science at MPIA
Iva Momcheva & Morgan Fouesneau
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
We present the newly created Data Science department at MPIA. We will first give you an overview of what means data science means in the astronomy context and present our activity plans for 2022. The department will support everyone in carrying out novel, cutting-edge research and establishing MPIA as a worldwide leader in astronomical data science by providing a platform to solidify foundational hacking & coding skills, a space to explore. develop, and share data science skills.

2022-03-04
15:00
Data Science at MPIA
Iva Momcheva & Morgan Fouesneau
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
We present the newly created Data Science department at MPIA. We will first give you an overview of what means data science means in the astronomy context and present our activity plans for 2022. The department will support everyone in carrying out novel, cutting-edge research and establishing MPIA as a worldwide leader in astronomical data science by providing a platform to solidify foundational hacking & coding skills, a space to explore. develop, and share data science skills.

2022-03-04
15:00
Data Science at MPIA
Iva Momcheva & Morgan Fouesneau
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
We present the newly created Data Science department at MPIA. We will first give you an overview of what means data science means in the astronomy context and present our activity plans for 2022. The department will support everyone in carrying out novel, cutting-edge research and establishing MPIA as a worldwide leader in astronomical data science by providing a platform to solidify foundational hacking & coding skills, a space to explore. develop, and share data science skills.

2022-02-25
15:00
TBA
Tom Mikal-Evans (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBA

2022-02-18
15:00
Protoplanetary disks and the dawn of planets
Leonardo Testi (ESO)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
In the classical picture of star and planet formation, disks are expected to form as a natural consequence of core collapse to form stars. Disks are then expected to mediate the extraction of excess angular momentum during the stellar accretion phase, and to be the locus of planet formation at later times. Reality is obviously much more complicated than this one line overview: disk properties “at birth” are a complex function of the star formation environment, the problem of transport in disks is far from being fully understood, as are the initial condition and timeline for planet formation. In this talk I will discuss some of these problems, mostly focusing on the successes and limitations of our understanding of the properties of individual disks and the global evolution of disk populations. I will discuss the current evidence for early planet formation in protoplanetary disks, and the open questions related to effect of the star formation environment across the Galaxy on disk properties and evolution, which likely also affect the planet formation process.

2022-02-18
15:00
Protoplanetary disks and the dawn of planets
Leonardo Testi (ESO)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
In the classical picture of star and planet formation, disks are expected to form as a natural consequence of core collapse to form stars. Disks are then expected to mediate the extraction of excess angular momentum during the stellar accretion phase, and to be the locus of planet formation at later times. Reality is obviously much more complicated than this one line overview: disk properties “at birth” are a complex function of the star formation environment, the problem of transport in disks is far from being fully understood, as are the initial condition and timeline for planet formation. In this talk I will discuss some of these problems, mostly focusing on the successes and limitations of our understanding of the properties of individual disks and the global evolution of disk populations. I will discuss the current evidence for early planet formation in protoplanetary disks, and the open questions related to effect of the star formation environment across the Galaxy on disk properties and evolution, which likely also affect the planet formation process.

2022-02-18
15:00
Protoplanetary disks and the dawn of planets
Leonardo Testi (ESO)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
In the classical picture of star and planet formation, disks are expected to form as a natural consequence of core collapse to form stars. Disks are then expected to mediate the extraction of excess angular momentum during the stellar accretion phase, and to be the locus of planet formation at later times. Reality is obviously much more complicated than this one line overview: disk properties “at birth” are a complex function of the star formation environment, the problem of transport in disks is far from being fully understood, as are the initial condition and timeline for planet formation. In this talk I will discuss some of these problems, mostly focusing on the successes and limitations of our understanding of the properties of individual disks and the global evolution of disk populations. I will discuss the current evidence for early planet formation in protoplanetary disks, and the open questions related to effect of the star formation environment across the Galaxy on disk properties and evolution, which likely also affect the planet formation process.

2022-02-18
15:00
Protoplanetary disks and the dawn of planets
Leonardo Testi (ESO)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
In the classical picture of star and planet formation, disks are expected to form as a natural consequence of core collapse to form stars. Disks are then expected to mediate the extraction of excess angular momentum during the stellar accretion phase, and to be the locus of planet formation at later times. Reality is obviously much more complicated than this one line overview: disk properties “at birth” are a complex function of the star formation environment, the problem of transport in disks is far from being fully understood, as are the initial condition and timeline for planet formation. In this talk I will discuss some of these problems, mostly focusing on the successes and limitations of our understanding of the properties of individual disks and the global evolution of disk populations. I will discuss the current evidence for early planet formation in protoplanetary disks, and the open questions related to effect of the star formation environment across the Galaxy on disk properties and evolution, which likely also affect the planet formation process.

2022-02-11
15:00
The origin of star and planetary systems
Stefan Kraus (University of Exeter)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Most stars do not exist alone but are orbited by planets or stellar-mass companions. One of the big open questions concerns how planetary systems and multiple-star systems form and what causes the diversity in their orbital architecture and compositional characteristics. In this talk, I will outline how infrared interferometry allows us to explore the origin of this diversity, either by observing systems in the process of formation or by deducing their history from the characteristics observed in fully-formed systems. I will discuss results from our MIRC-X 6 telescope imager at CHARA, where we achieve the resolution of a 330m telescope and search for potentially planet-induced structures in the innermost astronomical unit of protoplanetary disks. In the second part, I will present the ERC-funded GAIA-BIFROST project that will measure orbital parameters, precision masses, and spin-orbit alignments for thousands of binary and planetary systems. We will build a new beam-combination instrument for ESO's VLT Interferometer, named BIFROST, that will open the short-wavelength and high spectral-resolution window at VLTI. This will allow us to measure spin-orbit alignments for wide-separation planets and binaries, providing fundamentally new insights on the dynamical processes that shape system architectures. Finally, I will highlight the prospect of using BIFROST and other future missions for exoplanet spectroscopy and for decoding the formation history of these distant worlds.

2022-02-11
15:00
The origin of star and planetary systems
Stefan Kraus (University of Exeter)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Most stars do not exist alone but are orbited by planets or stellar-mass companions. One of the big open questions concerns how planetary systems and multiple-star systems form and what causes the diversity in their orbital architecture and compositional characteristics. In this talk, I will outline how infrared interferometry allows us to explore the origin of this diversity, either by observing systems in the process of formation or by deducing their history from the characteristics observed in fully-formed systems. I will discuss results from our MIRC-X 6 telescope imager at CHARA, where we achieve the resolution of a 330m telescope and search for potentially planet-induced structures in the innermost astronomical unit of protoplanetary disks. In the second part, I will present the ERC-funded GAIA-BIFROST project that will measure orbital parameters, precision masses, and spin-orbit alignments for thousands of binary and planetary systems. We will build a new beam-combination instrument for ESO's VLT Interferometer, named BIFROST, that will open the short-wavelength and high spectral-resolution window at VLTI. This will allow us to measure spin-orbit alignments for wide-separation planets and binaries, providing fundamentally new insights on the dynamical processes that shape system architectures. Finally, I will highlight the prospect of using BIFROST and other future missions for exoplanet spectroscopy and for decoding the formation history of these distant worlds.

2022-02-11
15:00
The origin of star and planetary systems
Stefan Kraus (University of Exeter)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Most stars do not exist alone but are orbited by planets or stellar-mass companions. One of the big open questions concerns how planetary systems and multiple-star systems form and what causes the diversity in their orbital architecture and compositional characteristics. In this talk, I will outline how infrared interferometry allows us to explore the origin of this diversity, either by observing systems in the process of formation or by deducing their history from the characteristics observed in fully-formed systems. I will discuss results from our MIRC-X 6 telescope imager at CHARA, where we achieve the resolution of a 330m telescope and search for potentially planet-induced structures in the innermost astronomical unit of protoplanetary disks. In the second part, I will present the ERC-funded GAIA-BIFROST project that will measure orbital parameters, precision masses, and spin-orbit alignments for thousands of binary and planetary systems. We will build a new beam-combination instrument for ESO's VLT Interferometer, named BIFROST, that will open the short-wavelength and high spectral-resolution window at VLTI. This will allow us to measure spin-orbit alignments for wide-separation planets and binaries, providing fundamentally new insights on the dynamical processes that shape system architectures. Finally, I will highlight the prospect of using BIFROST and other future missions for exoplanet spectroscopy and for decoding the formation history of these distant worlds.

2022-02-11
15:00
TBD
Stefan Kraus (University of Exeter)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
TBD

2022-02-11
15:00
The origin of star and planetary systems
Stefan Kraus (University of Exeter)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Most stars do not exist alone but are orbited by planets or stellar-mass companions. One of the big open questions concerns how planetary systems and multiple-star systems form and what causes the diversity in their orbital architecture and compositional characteristics. In this talk, I will outline how infrared interferometry allows us to explore the origin of this diversity, either by observing systems in the process of formation or by deducing their history from the characteristics observed in fully-formed systems. I will discuss results from our MIRC-X 6 telescope imager at CHARA, where we achieve the resolution of a 330m telescope and search for potentially planet-induced structures in the innermost astronomical unit of protoplanetary disks. In the second part, I will present the ERC-funded GAIA-BIFROST project that will measure orbital parameters, precision masses, and spin-orbit alignments for thousands of binary and planetary systems. We will build a new beam-combination instrument for ESO's VLT Interferometer, named BIFROST, that will open the short-wavelength and high spectral-resolution window at VLTI. This will allow us to measure spin-orbit alignments for wide-separation planets and binaries, providing fundamentally new insights on the dynamical processes that shape system architectures. Finally, I will highlight the prospect of using BIFROST and other future missions for exoplanet spectroscopy and for decoding the formation history of these distant worlds.

2022-02-11
11:00
TBD
Stefan Kraus (University of Exeter)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
TBD

2022-02-04
15:00
The mass growth in star-forming galaxies in the distant Universe
Ugne Dudzeviciute (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Roughly half of the star formation that has ever occurred was obscured
by dust, thus understanding the nature, origin, and evolution of this
dust-obscured activity in galaxies is crucial for furthering our
understanding of galaxy formation and growth. Some of the most
dust-obscured and actively star-forming galaxies at high redshift are
sub-millimetre galaxies, with star formation rates in the range
~100-1000 Mo/yr and large molecular gas reservoirs. In this talk I will
present the multi-wavelength analysis of the largest sample of ALMA
870?m-selected galaxies, which aimed to better understand the structure
of these systems and the role of the sub-millimetre bright phase in the
wider context of galaxy formation and evolution. For a more complete
view of the luminous far-infrared activity in the Universe over a wider
redshift range, I will also present a comparison to a sample of less
dust-obscured galaxies (those closer to the star-forming main-sequence)
from the deepest 450?m survey. Through studying the most dust-obscured
strongly star-forming systems, less extreme dust-obscured galaxies as
well as typical ‘main-sequence' galaxies, we were able to probe the mass
build-up across the ‘main-sequence'. The results suggest that the most
massive sub-millimetre galaxies reside in the most massive dark matter
halos that can still support efficient cooling and collapse of gas, and
that there might be differences in the processes of mass growth in
galaxies across the ‘main-sequence'.

2022-02-04
15:00
The mass growth in star-forming galaxies in the distant Universe
Ugne Dudzeviciute (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Roughly half of the star formation that has ever occurred was obscured
by dust, thus understanding the nature, origin, and evolution of this
dust-obscured activity in galaxies is crucial for furthering our
understanding of galaxy formation and growth. Some of the most
dust-obscured and actively star-forming galaxies at high redshift are
sub-millimetre galaxies, with star formation rates in the range
~100-1000 Mo/yr and large molecular gas reservoirs. In this talk I will
present the multi-wavelength analysis of the largest sample of ALMA
870?m-selected galaxies, which aimed to better understand the structure
of these systems and the role of the sub-millimetre bright phase in the
wider context of galaxy formation and evolution. For a more complete
view of the luminous far-infrared activity in the Universe over a wider
redshift range, I will also present a comparison to a sample of less
dust-obscured galaxies (those closer to the star-forming main-sequence)
from the deepest 450?m survey. Through studying the most dust-obscured
strongly star-forming systems, less extreme dust-obscured galaxies as
well as typical ‘main-sequence' galaxies, we were able to probe the mass
build-up across the ‘main-sequence'. The results suggest that the most
massive sub-millimetre galaxies reside in the most massive dark matter
halos that can still support efficient cooling and collapse of gas, and
that there might be differences in the processes of mass growth in
galaxies across the ‘main-sequence'.

2022-02-04
15:00
The mass growth in star-forming galaxies in the distant Universe
Ugne Dudzeviciute (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Roughly half of the star formation that has ever occurred was obscured
by dust, thus understanding the nature, origin, and evolution of this
dust-obscured activity in galaxies is crucial for furthering our
understanding of galaxy formation and growth. Some of the most
dust-obscured and actively star-forming galaxies at high redshift are
sub-millimetre galaxies, with star formation rates in the range
~100-1000 Mo/yr and large molecular gas reservoirs. In this talk I will
present the multi-wavelength analysis of the largest sample of ALMA
870?m-selected galaxies, which aimed to better understand the structure
of these systems and the role of the sub-millimetre bright phase in the
wider context of galaxy formation and evolution. For a more complete
view of the luminous far-infrared activity in the Universe over a wider
redshift range, I will also present a comparison to a sample of less
dust-obscured galaxies (those closer to the star-forming main-sequence)
from the deepest 450?m survey. Through studying the most dust-obscured
strongly star-forming systems, less extreme dust-obscured galaxies as
well as typical ‘main-sequence' galaxies, we were able to probe the mass
build-up across the ‘main-sequence'. The results suggest that the most
massive sub-millimetre galaxies reside in the most massive dark matter
halos that can still support efficient cooling and collapse of gas, and
that there might be differences in the processes of mass growth in
galaxies across the ‘main-sequence'.

2022-02-04
15:00
TBA
Ugne Dudzeviciute (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2022-02-04
15:00
The mass growth in star-forming galaxies in the distant Universe
Ugne Dudzeviciute (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Roughly half of the star formation that has ever occurred was obscured
by dust, thus understanding the nature, origin, and evolution of this
dust-obscured activity in galaxies is crucial for furthering our
understanding of galaxy formation and growth. Some of the most
dust-obscured and actively star-forming galaxies at high redshift are
sub-millimetre galaxies, with star formation rates in the range
~100-1000 Mo/yr and large molecular gas reservoirs. In this talk I will
present the multi-wavelength analysis of the largest sample of ALMA
870?m-selected galaxies, which aimed to better understand the structure
of these systems and the role of the sub-millimetre bright phase in the
wider context of galaxy formation and evolution. For a more complete
view of the luminous far-infrared activity in the Universe over a wider
redshift range, I will also present a comparison to a sample of less
dust-obscured galaxies (those closer to the star-forming main-sequence)
from the deepest 450?m survey. Through studying the most dust-obscured
strongly star-forming systems, less extreme dust-obscured galaxies as
well as typical ‘main-sequence' galaxies, we were able to probe the mass
build-up across the ‘main-sequence'. The results suggest that the most
massive sub-millimetre galaxies reside in the most massive dark matter
halos that can still support efficient cooling and collapse of gas, and
that there might be differences in the processes of mass growth in
galaxies across the ‘main-sequence'.

2022-01-28
15:00
TBA
Jan-Torge Schindler (Leiden Observatory)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
TBA

2022-01-28
15:00
TBA
Jan-Torge Schindler (Leiden Obs./MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
TBA

2022-01-28
15:00
The rise and fall of quasars
Jan-Torge Schindler (Leiden Obs./MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Quasars are the most luminous long-lived sources of light in the Universe. We understand their intense emission to be the signpost of rapid accretion of matter onto a supermassive black hole (SMBH). Empowered by wide-area optical and infrared sky surveys, the last two decades have seen rapid advances in the discovery of quasars at increasingly higher redshifts. With quasar surveys now spanning a timescale of roughly 10 billion years (z=0.3-7.6), I will review the most recent measurements of the quasar luminosity function, tracking the growth of SMBHs across cosmic time. In this context I will discuss the challenges of quasar surveys on the basis of my Extremely Luminous Quasar Survey (z=3-5) and then highlight my current efforts to provide the most precise estimate of the luminosity function at z=6 with the Pan-STARRS1 distant quasar survey. The recent increase in the number of quasars known at the highest redshifts (z>5.5) has enabled subsequent observing programs to investigate the accretion conditions and the gas properties around their central SMBHs. I will summarize the most recent insights, outline open questions and discuss how new and upcoming facilities (e.g., JWST, Euclid, LSST, …) will open a new perspective on the formation and evolution of SMBHs in the coming years.

2022-01-28
11:00
TBA
Jan-Torge Schindler (Leiden Obs./MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
TBA

2022-01-21
15:00
TBD
Sascha Quanz (ETH)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
TBD

2022-01-21
15:00
The direct detection of extrasolar planetary systems - motivation, challenges and opportunities
Sascha Quanz (ETH)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Since the discovery of the first extrasolar planet orbiting a Sun-like star in 1995, exoplanet science has been evolving into a highly dynamic field of modern astrophysics. Today, almost 5000 exoplanets have been confirmed and, thanks to ongoing efforts from the ground and from space, this number keeps continuously increasing. Most of the planets have been discovered via indirect techniques, such as the radial velocity and transit techniques. However, the direct detection of exoplanets is required to significantly expand the exoplanet discovery space, provide crucial links to planet formation studies, and, ultimately, test hypotheses related to exoplanet habitability and the possible existence of atmospheric biosignatures in a statistically relevant sample of objects. I will briefly discuss the challenges that need to be overcome to take a direct image or a spectrum of an exoplanet and then describe a roadmap what we can expect to learn from the direct detection of exoplanets as we go from currently available observatories (e.g., VLT and, very soon, the James Webb Space Telescope), to future observations with the ELT and, eventually, to new flagship-class space missions.

2022-01-21
11:00
TBD
Sascha Quanz (ETH)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
TBD

2021-12-17
15:00
TBD
Leonardo Testi (ESO)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
TBD

2021-12-17
15:00
TBD
Leonardo Testi (ESO)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2021-12-10
15:00
TBD
Heidelberg-Harvard participant (?)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2021-12-10
15:00
Finding Relativistic Stellar Explosions Using Optical Time-Domain Surveys
Anna Ho (UCB)
Königstuhl Kolloquium
Zoom,
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Abstract
Decades of observations of long-duration gamma-ray bursts (GRBs), attributed to relativistic jets launched in the collapse of massive stars, have yielded important insights on massive-star evolution, compact-object formation, and the physics of relativistic outflows. A major outstanding mystery is whether GRBs---occurring at only 0.1% of the supernova rate---simply represent the tip of the iceberg in a vast landscape of phenomena. To answer this question, with the Zwicky Transient Facility (ZTF) we are conducting a systematic exploration of the rest of the iceberg via searches for fast (hour to day) optical transients. In the past few years our searches yielded several orphan afterglows (afterglows without detected GRBs) at cosmological distances, supernovae with luminous X-ray and radio emission, and mildly relativistic explosions in dense circumstellar matter. Understanding the origin of these events and their relation to GRBs will require coordinated observations between high-cadence optical surveys, wide-field X-ray monitors, and millimeter and radio observatories. This will be possible in the next few years with the launch of the Space-based multi-band astronomical Variable Objects Monitor (SVOM), the enhanced cadence of ZTF Phase II, and sensitive millimeter-band facilities like the Atacama Large Millimeter Array (ALMA).

2021-12-10
15:00
TBD
Heidelberg-Harvard participant (?)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2021-12-03
15:00
TBD
Sara Rezaei Kh. (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2021-12-03
15:00
3D structures of the local molecular clouds and their implications for star formation
Sara Rezaei Kh. (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für ASTROLOGIE, Level 3 Lecture Hall (301)
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Abstract
The unprecedented astrometry from the Gaia mission has opened a new door to studying the solar neighbourhood in great detail. In order to get the wealth of information in this data, we have developed a state-of-the-art, three-dimensional dust mapping technique using Gaussian process, that provides detailed 3D maps of the Milky Way. We obtain the 3D positions of stars from Gaia, and their individual extinction using multi-band photometry, which are then used as the input for our model. Taking into account both distance and extinction uncertainties, together with the 3D spatial correlation between neighbouring points, we produce 3D maps of the local molecular clouds, revealing the 3D structures of individual clouds in fine detail.
In this talk, I will start by introducing dust and why it is an important component of the interstellar medium, followed by some of the most recent literature works in the field. Then I will introduce you to our Gaussian-process-based technique and its application to mapping the star-forming regions in the Milky Way. I will finish by showing some of our latest results on the important role of the 3D shape in star formation properties of the molecular clouds.

2021-11-26
15:00
Prize winners
Patzer colloquium
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2021-11-26
15:00
Prize winners
Patzer colloquium
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2021-11-26
15:00
Prize winners
Patzer colloquium
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2021-11-26
15:00
Prize winners
Patzer colloquium
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2021-11-26
15:00
Prize winners
Patzer colloquium
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2021-11-19
15:00
An astrochemical modeller's view of disks, planet formation and exoplanet atmospheres
Christian Eistrup (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
(Exo)planetary science has emerged as a field since the discovery of exoplanets, and a key part of this field is understanding how exoplanets form. Such understanding requires connecting observed exoplanets with characterised atmospheric properties to the environments in which they once formed: protoplanetary disk midplanes. I also requires insights and understanding of both the physical processes of planet formation, as well as the chemical compositions of planet-forming material. Chemical kinetics is gaining growing attention as a means to model how the chemical composition of material in protoplanetary disk may evolve and change during the course of planet formation, and how such chemical evolution may manifest itself in the composition of the exoplanet atmospheres that are soon to be characterised by JWST and other current and future facilities. In this talk, I will present new insights into how this "planet formation chemistry" depends on such important factors as sizes of the dust grains in the disk midplane, and the elemental ratio (C/O) of the host star, factors which are known to varying over time, and from system to system.

2021-11-19
15:00
TBD
Christian Eistrup (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2021-11-12
15:00
The Evolution of Volatile Carbon During Planet Formation
Kamber Schwarz (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The initial composition of a giant planet's atmosphere is set by the gas disk in which it forms. In this talk I will discuss recent ALMA observations which reveal low abundances of gas phase carbon in protoplanetary disks. This volatile sequestration, i.e., the removal of molecules such as CO from the gas, can occur via chemical reprocessing into less volatile species or trapping as ice in large planetesimals. Using disk chemical modeling, I will demonstrate that under most physical conditions both chemical and physical processes likely play a role in removing carbon from the gas on short timescales. I will then present ways to test various predictions regarding mechanisms to remove gas phase carbon and the dominate volatile carbon reservoir.

2021-11-12
15:00
The Evolution of Volatile Carbon During Planet Formation
Kamber Schwarz (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
The initial composition of a giant planet's atmosphere is set by the gas disk in which it forms. In this talk I will discuss recent ALMA observations which reveal low abundances of gas phase carbon in protoplanetary disks. This volatile sequestration, i.e., the removal of molecules such as CO from the gas, can occur via chemical reprocessing into less volatile species or trapping as ice in large planetesimals. Using disk chemical modeling, I will demonstrate that under most physical conditions both chemical and physical processes likely play a role in removing carbon from the gas on short timescales. I will then present ways to test various predictions regarding mechanisms to remove gas phase carbon and the dominate volatile carbon reservoir.

2021-11-05
15:00
Constraining planet formation
Bertram Bitsch (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Planet formation is a complex process, where in core-accretion models micro-meter sized dust grains grow all the way to gas giants within a few Myr during the lifetime of the protoplanetary disc. In the past, planet formation models would be judged on how good they can reproduce the observed exoplanet population in respect to their masses, radii, orbital parameters and occurrence rates. In this talk, I will first review the main ingredients for planet formation models and then discuss further methods that can be used to constrain planet formation models in more detail. In particular, I will focus on constraints from ALMA as well as on measurements of planetary atmospheric compositions and stellar abundances, opening up new avenues to constrain planet formation models.

2021-11-05
15:00
Constraining planet formation
Bertram Bitsch (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Planet formation is a complex process, where in core-accretion models micro-meter sized dust grains grow all the way to gas giants within a few Myr during the lifetime of the protoplanetary disc. In the past, planet formation models would be judged on how good they can reproduce the observed exoplanet population in respect to their masses, radii, orbital parameters and occurrence rates. In this talk, I will first review the main ingredients for planet formation models and then discuss further methods that can be used to constrain planet formation models in more detail. In particular, I will focus on constraints from ALMA as well as on measurements of planetary atmospheric compositions and stellar abundances, opening up new avenues to constrain planet formation models.

2021-10-29
15:00
Launching of astrophysical jets
Christian Fendt (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
I will present recent results of MHD simulations investigating the launching of astrophysical jets, covering both relativistic and non-relativistic flows. I will cover the topics of the 1) physical conditions at the launching point of jets, 2) the origin of the jet launching magnetic field as generated by a mean-field accretion disk dynamo, and 3) general relativistic jet launching from close to a black hole. I will start 0) with an introduction on the basic physics involved.

2021-10-29
15:00
Launching of astrophysical jets
Christian Fendt (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
I will present recent results of MHD simulations investigating the launching of astrophysical jets, covering both relativistic and non-relativistic flows. I will cover the topics of the 1) physical conditions at the launching point of jets, 2) the origin of the jet launching magnetic field as generated by a mean-field accretion disk dynamo, and 3) general relativistic jet launching from close to a black hole. I will start 0) with an introduction on the basic physics involved.

2021-10-22
15:00
TBD
Sümeyye Suri (Uni Vienna)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2021-10-22
15:00
Two decades of z>6 quasar hunt: Achievements, failures, and new hopes
Roberto Decarli (INAF-Bologna)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Since their first discovery about 20 years ago, luminous quasars at cosmic dawn have proven to be exceptional tools to investigate how massive black holes formed, how the first massive galaxies and large-scale structures assembled, and what physical processes shaped the Universe at its last phase transition (the epoch of reionization). In this talk I will review how the search for a new quasar frontier has evolved in the last twenty years, and address some of the lessons we learned so far from the discovered quasars. I will discuss some of the new and old (but lingering) open puzzles. Finally, I will provide an outlook from a biased observer's perspective on what we should expect from the field in the coming years, as new facilities offer unprecedented, exciting opportunities to study massive black holes in the infancy of galaxy formation.

2021-10-22
15:00
Two decades of z>6 quasar hunt: Achievements, failures, and new hopes
Roberto Decarli (INAF-Bologna)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Since their first discovery about 20 years ago, luminous quasars at cosmic dawn have proven to be exceptional tools to investigate how massive black holes formed, how the first massive galaxies and large-scale structures assembled, and what physical processes shaped the Universe at its last phase transition (the epoch of reionization). In this talk I will review how the search for a new quasar frontier has evolved in the last twenty years, and address some of the lessons we learned so far from the discovered quasars. I will discuss some of the new and old (but lingering) open puzzles. Finally, I will provide an outlook from a biased observer's perspective on what we should expect from the field in the coming years, as new facilities offer unprecedented, exciting opportunities to study massive black holes in the infancy of galaxy formation.

2021-10-15
15:00
Cold gas in distant galaxies
Leindert Boogaard (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Cold gas is the fuel for star formation and mapping the evolution of the cosmic molecular gas content is therefore key to our understanding of the build-up of galaxies over cosmic time. The advent of large millimeter interferometers now makes it possible to map the cold gas content of the universe in unprecedented detail. In this talk, I will present the latest results from the ALMA Spectroscopic Survey of the Hubble Ultra Deep Field (ASPECS), an ALMA large program that performed the largest three dimensional spectral-scan survey for cold gas and dust through cosmic time. I will discuss the resulting physical properties and conditions inside the cold interstellar medium of star-forming galaxies at cosmic noon, and the implications of ASPECS for the cosmic molecular gas density and the baryon cycle. I will close by discussing key steps we are working on to further refine our knowledge of cold gas in distant galaxies.

2021-10-15
15:00
Cold gas in distant galaxies
Leindert Boogaard (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Cold gas is the fuel for star formation and mapping the evolution of the cosmic molecular gas content is therefore key to our understanding of the build-up of galaxies over cosmic time. The advent of large millimeter interferometers now makes it possible to map the cold gas content of the universe in unprecedented detail. In this talk, I will present the latest results from the ALMA Spectroscopic Survey of the Hubble Ultra Deep Field (ASPECS), an ALMA large program that performed the largest three dimensional spectral-scan survey for cold gas and dust through cosmic time. I will discuss the resulting physical properties and conditions inside the cold interstellar medium of star-forming galaxies at cosmic noon, and the implications of ASPECS for the cosmic molecular gas density and the baryon cycle. I will close by discussing key steps we are working on to further refine our knowledge of cold gas in distant galaxies.

2021-10-08
15:00
TBD
Jacques Kluska (KU Leuven)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2021-10-08
15:00
TBD
Jacques Kluska (KU Leuven)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2021-10-08
15:00
Disks around evolved binaries: do they form second-generation planets?
Jacques Kluska (KU Leuven)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Most of the planets were formed around young stars. But can they form around evolved stars as well?
The origin of the diversity and complexity of the detected exoplanetary systems stems from how they form in protoplanetary disks. These disks are intensively studied around young stars thanks to the high-angular resolution provided by recent instruments (VLT, ALMA). However, similar disks are also found around evolved stars, namely post-AGB binaries, raising the exciting but yet unanswered question of second-generation planet formation.
While this question has only been tackled theoretically in the past, we have now the possibility to probe such second-generation planet formation by observations using high angular resolution instruments.
In this talk I will show the latest results of an extensive high angular resolution observing campaign of these disks using infrared interferometry at the VLTI (PIONIER, GRAVITY, MATISSE).
I will show that these disks share many similarities with protoplanetary disks around young stars.
These disks are, therefore, a unique laboratory to test planet formation scenarios in a parameter space that is unmet around young stars (e.g., short disk lifetime, high stellar luminosity, no influence from the environment).
Whether or not planet formation is possible at the end of stellar evolution, studying it in a very different parameter space will provide an unprecedented test to current planet formation theories.

2021-10-08
15:00
Disks around evolved binaries: do they form second-generation planets?
Jacques Kluska (KU Leuven)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Most of the planets were formed around young stars. But can they form around evolved stars as well?
The origin of the diversity and complexity of the detected exoplanetary systems stems from how they form in protoplanetary disks. These disks are intensively studied around young stars thanks to the high-angular resolution provided by recent instruments (VLT, ALMA). However, similar disks are also found around evolved stars, namely post-AGB binaries, raising the exciting but yet unanswered question of second-generation planet formation.
While this question has only been tackled theoretically in the past, we have now the possibility to probe such second-generation planet formation by observations using high angular resolution instruments.
In this talk I will show the latest results of an extensive high angular resolution observing campaign of these disks using infrared interferometry at the VLTI (PIONIER, GRAVITY, MATISSE).
I will show that these disks share many similarities with protoplanetary disks around young stars.
These disks are, therefore, a unique laboratory to test planet formation scenarios in a parameter space that is unmet around young stars (e.g., short disk lifetime, high stellar luminosity, no influence from the environment).
Whether or not planet formation is possible at the end of stellar evolution, studying it in a very different parameter space will provide an unprecedented test to current planet formation theories.

2021-10-01
15:00
How did large programs improve our understanding of the star formation process?
Sü Suri (Uni Vienna)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Recent observational large programs have allowed us to explore the pathways which lead to the formation of high-mass stars and their impact on the natal clouds. In the molecular cloud scales, filament fragmentation and mass accretion through networks of filaments play a key-role in the formation of high- and intermediate-mass stars. In sub-parsec scales, theoretical work predicts that high-mass stars form, similarly to their low-mass counterparts, through a disk-mediated process. In this talk, I will present results from a number of large programs carried out at CARMA, NOEMA, and SOFIA with the aim of understanding the star formation process at the scales of molecular clouds down to the scales of individual star-forming cores using high velocity and spatial resolution (sub-)mm and IR data.

2021-10-01
15:00
How did large programs improve our understanding of the star formation process?
Sü Suri (Uni Vienna)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Recent observational large programs have allowed us to explore the pathways which lead to the formation of high-mass stars and their impact on the natal clouds. In the molecular cloud scales, filament fragmentation and mass accretion through networks of filaments play a key-role in the formation of high- and intermediate-mass stars. In sub-parsec scales, theoretical work predicts that high-mass stars form, similarly to their low-mass counterparts, through a disk-mediated process. In this talk, I will present results from a number of large programs carried out at CARMA, NOEMA, and SOFIA with the aim of understanding the star formation process at the scales of molecular clouds down to the scales of individual star-forming cores using high velocity and spatial resolution (sub-)mm and IR data.

2021-09-24
15:00
TBD
Saskia Hekker (HITS)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2021-09-24
15:00
TBD
Saskia Hekker (HITS)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2021-09-24
15:00
Asteroseismology: what makes stars tick?
Saskia Hekker (HITS)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
What physical processes (i.e. energy transport, rotation, chemical mixing etc) inside a star cause the star to behave in a certain way? The surface properties of a star typically do not reveal enough information to infer these processes. Therefore, we need a window to look inside the stars. This window is provided by asteroseismology - the study of the internal structure of stars through their global oscillation modes. In this talk I will provide a brief introduction to this field and present some recent results as well as challenges we are facing.

2021-09-24
15:00
Asteroseismology: what makes stars tick?
Saskia Hekker (HITS)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
What physical processes (i.e. energy transport, rotation, chemical mixing etc) inside a star cause the star to behave in a certain way? The surface properties of a star typically do not reveal enough information to infer these processes. Therefore, we need a window to look inside the stars. This window is provided by asteroseismology - the study of the internal structure of stars through their global oscillation modes. In this talk I will provide a brief introduction to this field and present some recent results as well as challenges we are facing.

2021-08-06
15:00
The CARMENES search for exoplanets around M dwarfs: Disentangling planet signals and astrophysical noise
Stephan Stock (LSW)
Königstuhl Kolloquium
ia zoom link. Please contact organisers if you need the zoom information.,
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Abstract
The CARMENES radial-velocity (RV) survey of 365 M dwarfs to search for exoplanet has been in operation for more than five years at the 3.5 m telescope on Calar Alto, Spain. In the first part of the talk, I will give a short overview of results in which I was involved during my Ph.D. studies and that were possible thanks to CARMENES. The RV measurements of M-dwarf stars, which rank among the most active stars in the Universe, typically contain signals related to the star's rotational activity. Stellar astrophysical noise and aliasing caused by data sampling are significant obstacles that needed to be overcome for many investigated systems in the CARMENES survey. Therefore, in the second part of the talk, I will focus on a handful of such systems. I will demonstrate that it is possible to detect and model planetary RV signals at the limit of the stellar astrophysical noise by applying rigorous statistical models, along with prior information from auxiliary data and further simulations. I will also give more details regarding the disentanglement of stellar activity and planetary signals and our approach to model them by applying a Bayesian framework and Gaussian process (GP) regression models. Despite their advantages, GP models are still very controversial in the RV community due to their intrinsic flexibility and intransparency which brings the risk to come to wrong conclusions when incorporating a GP into the modeling. As part of my Ph.D. thesis, I have investigated the properties and the performance of GP models based on numerical simulations of simulated RV data of active M dwarfs. I will present some key outcomes from these simulations as well as some guidelines, tips and tricks on how to robustly use GP models for RV and photometric time series data. My goal is to convince you that while GP models can be risky if not applied correctly (as with many other types of models), they can be extremely helpful, even necessary, in many situations leading to the fact that not accounting for the correlated noise caused by the stellar activity of the star, for example by applying a GP model, might lead to wrong conclusions about the planets in the system.

2021-08-06
15:00
The CARMENES search for exoplanets around M dwarfs: Disentangling planet signals and astrophysical noise
Stephan Stock (LSW)
Königstuhl Kolloquium
ia zoom link. Please contact organisers if you need the zoom information.,
Show/hide abstract

Abstract
The CARMENES radial-velocity (RV) survey of 365 M dwarfs to search for exoplanet has been in operation for more than five years at the 3.5 m telescope on Calar Alto, Spain. In the first part of the talk, I will give a short overview of results in which I was involved during my Ph.D. studies and that were possible thanks to CARMENES. The RV measurements of M-dwarf stars, which rank among the most active stars in the Universe, typically contain signals related to the star's rotational activity. Stellar astrophysical noise and aliasing caused by data sampling are significant obstacles that needed to be overcome for many investigated systems in the CARMENES survey. Therefore, in the second part of the talk, I will focus on a handful of such systems. I will demonstrate that it is possible to detect and model planetary RV signals at the limit of the stellar astrophysical noise by applying rigorous statistical models, along with prior information from auxiliary data and further simulations. I will also give more details regarding the disentanglement of stellar activity and planetary signals and our approach to model them by applying a Bayesian framework and Gaussian process (GP) regression models. Despite their advantages, GP models are still very controversial in the RV community due to their intrinsic flexibility and intransparency which brings the risk to come to wrong conclusions when incorporating a GP into the modeling. As part of my Ph.D. thesis, I have investigated the properties and the performance of GP models based on numerical simulations of simulated RV data of active M dwarfs. I will present some key outcomes from these simulations as well as some guidelines, tips and tricks on how to robustly use GP models for RV and photometric time series data. My goal is to convince you that while GP models can be risky if not applied correctly (as with many other types of models), they can be extremely helpful, even necessary, in many situations leading to the fact that not accounting for the correlated noise caused by the stellar activity of the star, for example by applying a GP model, might lead to wrong conclusions about the planets in the system.

2021-08-06
15:00
The CARMENES search for exoplanets around M dwarfs: Disentangling planet signals and astrophysical noise
Stephan Stock (LSW)
Königstuhl Kolloquium
ia zoom link. Please contact organisers if you need the zoom information.,
Show/hide abstract

Abstract
The CARMENES radial-velocity (RV) survey of 365 M dwarfs to search for exoplanet has been in operation for more than five years at the 3.5 m telescope on Calar Alto, Spain. In the first part of the talk, I will give a short overview of results in which I was involved during my Ph.D. studies and that were possible thanks to CARMENES. The RV measurements of M-dwarf stars, which rank among the most active stars in the Universe, typically contain signals related to the star's rotational activity. Stellar astrophysical noise and aliasing caused by data sampling are significant obstacles that needed to be overcome for many investigated systems in the CARMENES survey. Therefore, in the second part of the talk, I will focus on a handful of such systems. I will demonstrate that it is possible to detect and model planetary RV signals at the limit of the stellar astrophysical noise by applying rigorous statistical models, along with prior information from auxiliary data and further simulations. I will also give more details regarding the disentanglement of stellar activity and planetary signals and our approach to model them by applying a Bayesian framework and Gaussian process (GP) regression models. Despite their advantages, GP models are still very controversial in the RV community due to their intrinsic flexibility and intransparency which brings the risk to come to wrong conclusions when incorporating a GP into the modeling. As part of my Ph.D. thesis, I have investigated the properties and the performance of GP models based on numerical simulations of simulated RV data of active M dwarfs. I will present some key outcomes from these simulations as well as some guidelines, tips and tricks on how to robustly use GP models for RV and photometric time series data. My goal is to convince you that while GP models can be risky if not applied correctly (as with many other types of models), they can be extremely helpful, even necessary, in many situations leading to the fact that not accounting for the correlated noise caused by the stellar activity of the star, for example by applying a GP model, might lead to wrong conclusions about the planets in the system.

2021-08-06
15:00
The CARMENES search for exoplanets around M dwarfs: Disentangling planet signals and astrophysical noise
Stephan Stock (LSW)
Königstuhl Kolloquium
ia zoom link. Please contact organisers if you need the zoom information.,
Show/hide abstract

Abstract
The CARMENES radial-velocity (RV) survey of 365 M dwarfs to search for exoplanet has been in operation for more than five years at the 3.5 m telescope on Calar Alto, Spain. In the first part of the talk, I will give a short overview of results in which I was involved during my Ph.D. studies and that were possible thanks to CARMENES. The RV measurements of M-dwarf stars, which rank among the most active stars in the Universe, typically contain signals related to the star's rotational activity. Stellar astrophysical noise and aliasing caused by data sampling are significant obstacles that needed to be overcome for many investigated systems in the CARMENES survey. Therefore, in the second part of the talk, I will focus on a handful of such systems. I will demonstrate that it is possible to detect and model planetary RV signals at the limit of the stellar astrophysical noise by applying rigorous statistical models, along with prior information from auxiliary data and further simulations. I will also give more details regarding the disentanglement of stellar activity and planetary signals and our approach to model them by applying a Bayesian framework and Gaussian process (GP) regression models. Despite their advantages, GP models are still very controversial in the RV community due to their intrinsic flexibility and intransparency which brings the risk to come to wrong conclusions when incorporating a GP into the modeling. As part of my Ph.D. thesis, I have investigated the properties and the performance of GP models based on numerical simulations of simulated RV data of active M dwarfs. I will present some key outcomes from these simulations as well as some guidelines, tips and tricks on how to robustly use GP models for RV and photometric time series data. My goal is to convince you that while GP models can be risky if not applied correctly (as with many other types of models), they can be extremely helpful, even necessary, in many situations leading to the fact that not accounting for the correlated noise caused by the stellar activity of the star, for example by applying a GP model, might lead to wrong conclusions about the planets in the system.

2021-07-30
15:00
tbd
Stephan Stock (LSW)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2021-07-30
15:00
Picture a Scientist
Movie Screening (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)

2021-07-23
15:00
Star formation and feedback in low-mass molecular clouds - a 3D view
Steffi Walch-Gassner (Uni Cologne)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Star formation takes place in the densest and coldest parts of the interstellar medium (ISM), in dark molecular clouds. These are swept up by multiple supernova explosions on scales of several hundred parsec. While condensing out of the warm ISM, the clouds are continuously fed with fresh gas. Thus, the turbulent substructure and magnetic field properties are imprinted during cloud formation. The formation of dense clouds from the multi-phase ISM, the onset of star formation, and the evolution of the molecular clouds under the impact of stellar feedback from newly born massive stars is studied in high-resolution simulations within the SILCC-Zoom project.
In this talk I will show how the evolution of self-consistently formed molecular clouds is governed by stellar feedback from newly born massive stars. Our simulated molecular clouds resemble nearby molecular clouds like Taurus and Ophiuchus. We investigate how the presence of a magnetic field impacts the structure of the forming molecular clouds and find that the presence of a magnetic field leads to more fluffy clouds. In general, the detailed cloud substructure (and therefore highly localised shielding factors) determines the clouds' vulnerability to stellar feedback processes, in particular to ionizing radiation, as well as the clustering properties of the new-born stars. Moreover, we find that the ionization state of the gas can be highly variable on scales of tens of parsec due to small-scale turbulent motions within the star-forming clouds, which shield and release the ionizing radiation. Overall, the efficiency of star formation is quite effectively regulated by stellar (pre-supernova) feedback on small scales.
By means of synthetic observations, we also investigate in detail how our simulations would appear to an observer. I will show a few examples focussing on CO and ionized carbon and discussing CO-dark molecular gas.

2021-07-23
15:00
Star formation and feedback in low-mass molecular clouds - a 3D view
Steffi Walch-Gassner (Uni Cologne)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Star formation takes place in the densest and coldest parts of the interstellar medium (ISM), in dark molecular clouds. These are swept up by multiple supernova explosions on scales of several hundred parsec. While condensing out of the warm ISM, the clouds are continuously fed with fresh gas. Thus, the turbulent substructure and magnetic field properties are imprinted during cloud formation. The formation of dense clouds from the multi-phase ISM, the onset of star formation, and the evolution of the molecular clouds under the impact of stellar feedback from newly born massive stars is studied in high-resolution simulations within the SILCC-Zoom project.
In this talk I will show how the evolution of self-consistently formed molecular clouds is governed by stellar feedback from newly born massive stars. Our simulated molecular clouds resemble nearby molecular clouds like Taurus and Ophiuchus. We investigate how the presence of a magnetic field impacts the structure of the forming molecular clouds and find that the presence of a magnetic field leads to more fluffy clouds. In general, the detailed cloud substructure (and therefore highly localised shielding factors) determines the clouds' vulnerability to stellar feedback processes, in particular to ionizing radiation, as well as the clustering properties of the new-born stars. Moreover, we find that the ionization state of the gas can be highly variable on scales of tens of parsec due to small-scale turbulent motions within the star-forming clouds, which shield and release the ionizing radiation. Overall, the efficiency of star formation is quite effectively regulated by stellar (pre-supernova) feedback on small scales.
By means of synthetic observations, we also investigate in detail how our simulations would appear to an observer. I will show a few examples focussing on CO and ionized carbon and discussing CO-dark molecular gas.

2021-07-23
15:00
Star formation and feedback in low-mass molecular clouds - a 3D view
Steffi Walch-Gassner (Uni Cologne)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Star formation takes place in the densest and coldest parts of the interstellar medium (ISM), in dark molecular clouds. These are swept up by multiple supernova explosions on scales of several hundred parsec. While condensing out of the warm ISM, the clouds are continuously fed with fresh gas. Thus, the turbulent substructure and magnetic field properties are imprinted during cloud formation. The formation of dense clouds from the multi-phase ISM, the onset of star formation, and the evolution of the molecular clouds under the impact of stellar feedback from newly born massive stars is studied in high-resolution simulations within the SILCC-Zoom project.
In this talk I will show how the evolution of self-consistently formed molecular clouds is governed by stellar feedback from newly born massive stars. Our simulated molecular clouds resemble nearby molecular clouds like Taurus and Ophiuchus. We investigate how the presence of a magnetic field impacts the structure of the forming molecular clouds and find that the presence of a magnetic field leads to more fluffy clouds. In general, the detailed cloud substructure (and therefore highly localised shielding factors) determines the clouds' vulnerability to stellar feedback processes, in particular to ionizing radiation, as well as the clustering properties of the new-born stars. Moreover, we find that the ionization state of the gas can be highly variable on scales of tens of parsec due to small-scale turbulent motions within the star-forming clouds, which shield and release the ionizing radiation. Overall, the efficiency of star formation is quite effectively regulated by stellar (pre-supernova) feedback on small scales.
By means of synthetic observations, we also investigate in detail how our simulations would appear to an observer. I will show a few examples focussing on CO and ionized carbon and discussing CO-dark molecular gas.

2021-07-23
15:00
Star formation and feedback in low-mass molecular clouds - a 3D view
Steffi Walch-Gassner (Uni Cologne)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Star formation takes place in the densest and coldest parts of the interstellar medium (ISM), in dark molecular clouds. These are swept up by multiple supernova explosions on scales of several hundred parsec. While condensing out of the warm ISM, the clouds are continuously fed with fresh gas. Thus, the turbulent substructure and magnetic field properties are imprinted during cloud formation. The formation of dense clouds from the multi-phase ISM, the onset of star formation, and the evolution of the molecular clouds under the impact of stellar feedback from newly born massive stars is studied in high-resolution simulations within the SILCC-Zoom project.
In this talk I will show how the evolution of self-consistently formed molecular clouds is governed by stellar feedback from newly born massive stars. Our simulated molecular clouds resemble nearby molecular clouds like Taurus and Ophiuchus. We investigate how the presence of a magnetic field impacts the structure of the forming molecular clouds and find that the presence of a magnetic field leads to more fluffy clouds. In general, the detailed cloud substructure (and therefore highly localised shielding factors) determines the clouds' vulnerability to stellar feedback processes, in particular to ionizing radiation, as well as the clustering properties of the new-born stars. Moreover, we find that the ionization state of the gas can be highly variable on scales of tens of parsec due to small-scale turbulent motions within the star-forming clouds, which shield and release the ionizing radiation. Overall, the efficiency of star formation is quite effectively regulated by stellar (pre-supernova) feedback on small scales.
By means of synthetic observations, we also investigate in detail how our simulations would appear to an observer. I will show a few examples focussing on CO and ionized carbon and discussing CO-dark molecular gas.

2021-07-16
15:00
New Ideas in Instrument Calibration
David Hogg (NYU/MPIA/Flatiron Institute)
Königstuhl Kolloquium
ia zoom link. Please contact organisers if you need the zoom information.,
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Abstract
In many contexts in astrophysics we are faced with instrument-calibration problems where precision (or accuracy) are of utmost importance\; these include imagers, spectrographs, and interferometers. I will discuss a few new and important ideas in calibration including (a) self-calibration, in which the scientific data of interest are used to directly determine calibration parameters, (b) cross-calibration, in which a poorly calibrated instrument is calibrated by comparing the science data with observations made at another instrument, and (c) hierarchical (or causal) models, in which the calibration state for one observation is determined not just from nearby (in time) calibration data but instead from combining all data ever taken with the instrument into a data-driven model of the instrument's behavior. I discuss all of these ideas in the context of extreme precision star and planet projects (think radial velocities, transits and transit spectroscopy, and detailed abundances) but the ideas apply across all kinds of astronomical instrumentation, catalogs, and projects. I'll give examples in which we substantially improved precision-measurement projects.

2021-07-16
15:00
New Ideas in Instrument Calibration
David Hogg (NYU/MPIA/Flatiron Institute)
Königstuhl Kolloquium
ia zoom link. Please contact organisers if you need the zoom information.,
Show/hide abstract

Abstract
In many contexts in astrophysics we are faced with instrument-calibration problems where precision (or accuracy) are of utmost importance\; these include imagers, spectrographs, and interferometers. I will discuss a few new and important ideas in calibration including (a) self-calibration, in which the scientific data of interest are used to directly determine calibration parameters, (b) cross-calibration, in which a poorly calibrated instrument is calibrated by comparing the science data with observations made at another instrument, and (c) hierarchical (or causal) models, in which the calibration state for one observation is determined not just from nearby (in time) calibration data but instead from combining all data ever taken with the instrument into a data-driven model of the instrument's behavior. I discuss all of these ideas in the context of extreme precision star and planet projects (think radial velocities, transits and transit spectroscopy, and detailed abundances) but the ideas apply across all kinds of astronomical instrumentation, catalogs, and projects. I'll give examples in which we substantially improved precision-measurement projects.

2021-07-16
15:00
New Ideas in Instrument Calibration
David Hogg (NYU/MPIA/Flatiron Institute)
Königstuhl Kolloquium
ia zoom link. Please contact organisers if you need the zoom information.,
Show/hide abstract

Abstract
In many contexts in astrophysics we are faced with instrument-calibration problems where precision (or accuracy) are of utmost importance\; these include imagers, spectrographs, and interferometers. I will discuss a few new and important ideas in calibration including (a) self-calibration, in which the scientific data of interest are used to directly determine calibration parameters, (b) cross-calibration, in which a poorly calibrated instrument is calibrated by comparing the science data with observations made at another instrument, and (c) hierarchical (or causal) models, in which the calibration state for one observation is determined not just from nearby (in time) calibration data but instead from combining all data ever taken with the instrument into a data-driven model of the instrument's behavior. I discuss all of these ideas in the context of extreme precision star and planet projects (think radial velocities, transits and transit spectroscopy, and detailed abundances) but the ideas apply across all kinds of astronomical instrumentation, catalogs, and projects. I'll give examples in which we substantially improved precision-measurement projects.

2021-07-16
15:00
New Ideas in Instrument Calibration
David Hogg (NYU/MPIA/Flatiron Institute)
Königstuhl Kolloquium
ia zoom link. Please contact organisers if you need the zoom information.,
Show/hide abstract

Abstract
In many contexts in astrophysics we are faced with instrument-calibration problems where precision (or accuracy) are of utmost importance\; these include imagers, spectrographs, and interferometers. I will discuss a few new and important ideas in calibration including (a) self-calibration, in which the scientific data of interest are used to directly determine calibration parameters, (b) cross-calibration, in which a poorly calibrated instrument is calibrated by comparing the science data with observations made at another instrument, and (c) hierarchical (or causal) models, in which the calibration state for one observation is determined not just from nearby (in time) calibration data but instead from combining all data ever taken with the instrument into a data-driven model of the instrument's behavior. I discuss all of these ideas in the context of extreme precision star and planet projects (think radial velocities, transits and transit spectroscopy, and detailed abundances) but the ideas apply across all kinds of astronomical instrumentation, catalogs, and projects. I'll give examples in which we substantially improved precision-measurement projects.

2021-07-09
15:00
R-process: connecting simulations to observations
Almudena Arcones (Uni. Darmstadt)
Königstuhl Kolloquium
ia zoom link. Please contact organisers if you need the zoom information.,
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Abstract
The heaviest elements form by the rapid neutron capture process (r-process) in neutron star mergers and rare core-collapse supernovae. The light curve of the kilonova following the neutron star merger GW170817 showed indications of heavy elements being produced and direct observation of Strontium. This talk will report on recent breakthroughs in understanding the extreme environment in which the formation of the heavy elements occurs, as well as open questions regarding the astrophysics and nuclear physics involved.

2021-07-09
15:00
R-process: connecting simulations to observations
Almudena Arcones (Uni. Darmstadt)
Königstuhl Kolloquium
ia zoom link. Please contact organisers if you need the zoom information.,
Show/hide abstract

Abstract
The heaviest elements form by the rapid neutron capture process (r-process) in neutron star mergers and rare core-collapse supernovae. The light curve of the kilonova following the neutron star merger GW170817 showed indications of heavy elements being produced and direct observation of Strontium. This talk will report on recent breakthroughs in understanding the extreme environment in which the formation of the heavy elements occurs, as well as open questions regarding the astrophysics and nuclear physics involved.

2021-07-09
15:00
R-process: connecting simulations to observations
Almudena Arcones (Uni. Darmstadt)
Königstuhl Kolloquium
ia zoom link. Please contact organisers if you need the zoom information.,
Show/hide abstract

Abstract
The heaviest elements form by the rapid neutron capture process (r-process) in neutron star mergers and rare core-collapse supernovae. The light curve of the kilonova following the neutron star merger GW170817 showed indications of heavy elements being produced and direct observation of Strontium. This talk will report on recent breakthroughs in understanding the extreme environment in which the formation of the heavy elements occurs, as well as open questions regarding the astrophysics and nuclear physics involved.

2021-07-09
15:00
R-process: connecting simulations to observations
Almudena Arcones (Uni. Darmstadt)
Königstuhl Kolloquium
ia zoom link. Please contact organisers if you need the zoom information.,
Show/hide abstract

Abstract
The heaviest elements form by the rapid neutron capture process (r-process) in neutron star mergers and rare core-collapse supernovae. The light curve of the kilonova following the neutron star merger GW170817 showed indications of heavy elements being produced and direct observation of Strontium. This talk will report on recent breakthroughs in understanding the extreme environment in which the formation of the heavy elements occurs, as well as open questions regarding the astrophysics and nuclear physics involved.

2021-07-02
15:00
Solids in planet forming disks ? What have we learned after 10 years of ALMA?
Til Birnstiel (LMU)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Despite a wealth of observations from exoplanets and our own solar system, fundamental questions remain about how planets form. Most of planet formation happens well hidden in circumstellar disks and only within the last decade, ALMA and SPHERE started to give us glimpses into the detailed structure of disks and their population properties. In this talk I will introduce the key concepts of how the solid material in disks evolves and how we can observe these processes. I will discuss how high resolution studies on the one hand and lower resolution surveys on the other hand can shed some light on the earliest stages of planet formation and which new questions have emerged.

2021-07-02
15:00
Solids in planet forming disks ? What have we learned after 10 years of ALMA?
Til Birnstiel (LMU)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Despite a wealth of observations from exoplanets and our own solar system, fundamental questions remain about how planets form. Most of planet formation happens well hidden in circumstellar disks and only within the last decade, ALMA and SPHERE started to give us glimpses into the detailed structure of disks and their population properties. In this talk I will introduce the key concepts of how the solid material in disks evolves and how we can observe these processes. I will discuss how high resolution studies on the one hand and lower resolution surveys on the other hand can shed some light on the earliest stages of planet formation and which new questions have emerged.

2021-07-02
15:00
Solids in planet forming disks ? What have we learned after 10 years of ALMA?
Til Birnstiel (LMU)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Despite a wealth of observations from exoplanets and our own solar system, fundamental questions remain about how planets form. Most of planet formation happens well hidden in circumstellar disks and only within the last decade, ALMA and SPHERE started to give us glimpses into the detailed structure of disks and their population properties. In this talk I will introduce the key concepts of how the solid material in disks evolves and how we can observe these processes. I will discuss how high resolution studies on the one hand and lower resolution surveys on the other hand can shed some light on the earliest stages of planet formation and which new questions have emerged.

2021-07-02
15:00
Solids in planet forming disks ? What have we learned after 10 years of ALMA?
Til Birnstiel (LMU)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Despite a wealth of observations from exoplanets and our own solar system, fundamental questions remain about how planets form. Most of planet formation happens well hidden in circumstellar disks and only within the last decade, ALMA and SPHERE started to give us glimpses into the detailed structure of disks and their population properties. In this talk I will introduce the key concepts of how the solid material in disks evolves and how we can observe these processes. I will discuss how high resolution studies on the one hand and lower resolution surveys on the other hand can shed some light on the earliest stages of planet formation and which new questions have emerged.

2021-06-25
15:00
The Many Diverse Manifestations of Supermassive Black-Hole Feedback
Annalisa Pillepich (MPIA)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
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Abstract
Feedback from super massive black holes (SMBHs) is commonly invoked in state-of-the-art large-scale cosmological galaxy simulations to halt star formation in massive galaxies. In fact, no other mechanism so far has been shown to be capable of returning entire populations of simulated massive quenched galaxies that are consistent with the observed galaxy red sequence and quenched fractions. In this talk, I will show how the IllustrisTNG cosmological simulations of galaxies allow us to gain insights and testable predictions on the manifestations of these energetic phenomena. With IllustrisTNG, with one unique set of physical ingredients, we simultaneously resolve and model the inner structural details of thousands of galaxies across five orders of magnitude in stellar mass, across environments, and together with the evolution and dynamics of the inter-stellar, circum-galactic and inter-galactic media. We are putting together ever more quantitative and plausible evidences as to the role that feedback from SMBH can have, not only in shaping galaxy structural properties and galaxy populations across 90 per cent of the Universe's history, but also in regulating the thermodynamical, ionization, and metal enrichment properties of the cosmic gas across halo scales and beyond. In particular, I will show how the IllustrisTNG model predicts that the gaseous atmospheres within and around galaxies are X-ray *brighter* for star-forming than for quiescent galaxies at the transitional mass scale of ~10^10-11 solar masses. I will discuss how novel results on the observed quenched fractions from SDSS support the ejective character of SMBH feedback from the central galaxies in groups and clusters at low redshift. And finally I will show that the TNG50 simulation naturally returns X-ray emitting bubbles that resemble the eROSITA and Fermi bubbles observed at the center of our Galaxy.

2021-06-25
15:00
The Many Diverse Manifestations of Supermassive Black-Hole Feedback
Annalisa Pillepich (MPIA)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
Show/hide abstract

Abstract
Feedback from super massive black holes (SMBHs) is commonly invoked in state-of-the-art large-scale cosmological galaxy simulations to halt star formation in massive galaxies. In fact, no other mechanism so far has been shown to be capable of returning entire populations of simulated massive quenched galaxies that are consistent with the observed galaxy red sequence and quenched fractions. In this talk, I will show how the IllustrisTNG cosmological simulations of galaxies allow us to gain insights and testable predictions on the manifestations of these energetic phenomena. With IllustrisTNG, with one unique set of physical ingredients, we simultaneously resolve and model the inner structural details of thousands of galaxies across five orders of magnitude in stellar mass, across environments, and together with the evolution and dynamics of the inter-stellar, circum-galactic and inter-galactic media. We are putting together ever more quantitative and plausible evidences as to the role that feedback from SMBH can have, not only in shaping galaxy structural properties and galaxy populations across 90 per cent of the Universe's history, but also in regulating the thermodynamical, ionization, and metal enrichment properties of the cosmic gas across halo scales and beyond. In particular, I will show how the IllustrisTNG model predicts that the gaseous atmospheres within and around galaxies are X-ray *brighter* for star-forming than for quiescent galaxies at the transitional mass scale of ~10^10-11 solar masses. I will discuss how novel results on the observed quenched fractions from SDSS support the ejective character of SMBH feedback from the central galaxies in groups and clusters at low redshift. And finally I will show that the TNG50 simulation naturally returns X-ray emitting bubbles that resemble the eROSITA and Fermi bubbles observed at the center of our Galaxy.

2021-06-25
15:00
The Many Diverse Manifestations of Supermassive Black-Hole Feedback
Annalisa Pillepich (MPIA)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
Show/hide abstract

Abstract
Feedback from super massive black holes (SMBHs) is commonly invoked in state-of-the-art large-scale cosmological galaxy simulations to halt star formation in massive galaxies. In fact, no other mechanism so far has been shown to be capable of returning entire populations of simulated massive quenched galaxies that are consistent with the observed galaxy red sequence and quenched fractions. In this talk, I will show how the IllustrisTNG cosmological simulations of galaxies allow us to gain insights and testable predictions on the manifestations of these energetic phenomena. With IllustrisTNG, with one unique set of physical ingredients, we simultaneously resolve and model the inner structural details of thousands of galaxies across five orders of magnitude in stellar mass, across environments, and together with the evolution and dynamics of the inter-stellar, circum-galactic and inter-galactic media. We are putting together ever more quantitative and plausible evidences as to the role that feedback from SMBH can have, not only in shaping galaxy structural properties and galaxy populations across 90 per cent of the Universe's history, but also in regulating the thermodynamical, ionization, and metal enrichment properties of the cosmic gas across halo scales and beyond. In particular, I will show how the IllustrisTNG model predicts that the gaseous atmospheres within and around galaxies are X-ray *brighter* for star-forming than for quiescent galaxies at the transitional mass scale of ~10^10-11 solar masses. I will discuss how novel results on the observed quenched fractions from SDSS support the ejective character of SMBH feedback from the central galaxies in groups and clusters at low redshift. And finally I will show that the TNG50 simulation naturally returns X-ray emitting bubbles that resemble the eROSITA and Fermi bubbles observed at the center of our Galaxy.

2021-06-25
15:00
The Many Diverse Manifestations of Supermassive Black-Hole Feedback
Annalisa Pillepich (MPIA)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
Show/hide abstract

Abstract
Feedback from super massive black holes (SMBHs) is commonly invoked in state-of-the-art large-scale cosmological galaxy simulations to halt star formation in massive galaxies. In fact, no other mechanism so far has been shown to be capable of returning entire populations of simulated massive quenched galaxies that are consistent with the observed galaxy red sequence and quenched fractions. In this talk, I will show how the IllustrisTNG cosmological simulations of galaxies allow us to gain insights and testable predictions on the manifestations of these energetic phenomena. With IllustrisTNG, with one unique set of physical ingredients, we simultaneously resolve and model the inner structural details of thousands of galaxies across five orders of magnitude in stellar mass, across environments, and together with the evolution and dynamics of the inter-stellar, circum-galactic and inter-galactic media. We are putting together ever more quantitative and plausible evidences as to the role that feedback from SMBH can have, not only in shaping galaxy structural properties and galaxy populations across 90 per cent of the Universe's history, but also in regulating the thermodynamical, ionization, and metal enrichment properties of the cosmic gas across halo scales and beyond. In particular, I will show how the IllustrisTNG model predicts that the gaseous atmospheres within and around galaxies are X-ray *brighter* for star-forming than for quiescent galaxies at the transitional mass scale of ~10^10-11 solar masses. I will discuss how novel results on the observed quenched fractions from SDSS support the ejective character of SMBH feedback from the central galaxies in groups and clusters at low redshift. And finally I will show that the TNG50 simulation naturally returns X-ray emitting bubbles that resemble the eROSITA and Fermi bubbles observed at the center of our Galaxy.

2021-06-18
15:00
The architectures of planetary systems: Population synthesis meets observations
Martin Schlecker (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Exoplanets are now routinely detected and their properties, such as their mass and orbital periods, can be constrained to high precision. While it is widely recognized that multiple planets per system are common, their mutual relationships are still largely unexplored. By confronting simulated planet populations with observed exoplanets, I will show that planetary properties and the architectures of their host planetary systems are related, and, more specifically, that observables of small planets on short orbits might be used to infer the existence of additional planetary companions. I will discuss how a solidification of this prediction has the power to constrain central open questions in contemporary planet formation theory, ranging from the efficiency of pebble accretion to planet migration.

2021-06-18
15:00
The architectures of planetary systems: Population synthesis meets observations
Martin Schlecker (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Exoplanets are now routinely detected and their properties, such as their mass and orbital periods, can be constrained to high precision. While it is widely recognized that multiple planets per system are common, their mutual relationships are still largely unexplored. By confronting simulated planet populations with observed exoplanets, I will show that planetary properties and the architectures of their host planetary systems are related, and, more specifically, that observables of small planets on short orbits might be used to infer the existence of additional planetary companions. I will discuss how a solidification of this prediction has the power to constrain central open questions in contemporary planet formation theory, ranging from the efficiency of pebble accretion to planet migration.

2021-06-18
15:00
The architectures of planetary systems: Population synthesis meets observations
Martin Schlecker (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Exoplanets are now routinely detected and their properties, such as their mass and orbital periods, can be constrained to high precision. While it is widely recognized that multiple planets per system are common, their mutual relationships are still largely unexplored. By confronting simulated planet populations with observed exoplanets, I will show that planetary properties and the architectures of their host planetary systems are related, and, more specifically, that observables of small planets on short orbits might be used to infer the existence of additional planetary companions. I will discuss how a solidification of this prediction has the power to constrain central open questions in contemporary planet formation theory, ranging from the efficiency of pebble accretion to planet migration.

2021-06-18
15:00
The architectures of planetary systems: Population synthesis meets observations
Martin Schlecker (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Exoplanets are now routinely detected and their properties, such as their mass and orbital periods, can be constrained to high precision. While it is widely recognized that multiple planets per system are common, their mutual relationships are still largely unexplored. By confronting simulated planet populations with observed exoplanets, I will show that planetary properties and the architectures of their host planetary systems are related, and, more specifically, that observables of small planets on short orbits might be used to infer the existence of additional planetary companions. I will discuss how a solidification of this prediction has the power to constrain central open questions in contemporary planet formation theory, ranging from the efficiency of pebble accretion to planet migration.

2021-06-11
15:00
High resolution observations of protoplanetary disk structures
Myriam Benisty (IPAG)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract

Recent observing campaigns have revealed a great diversity in exoplanetary systems whose origin is yet to be understood. How and when planets form, and how they evolve and interact with their birth environment, the protoplanetary disks, are major open questions. Protoplanetary disks evolve and dissipate rapidly while planets are forming, implying a direct feedback between the processes of planet formation and disk evolution. These mechanisms leave clear imprints on the disk structure that can be directly observed. In the past few years, high-resolution observations of protoplanetary disks obtained in the infrared and in the millimeter regime have led to exquisite images and shown that small scale structures are ubiquitous in protoplanetary disks. I will present recent observational results on protoplanetary disks obtained with VLTI, VLT/SPHERE and ALMA, that allow to probe the disk structure and the dynamics of solids, and in particular, in the so far unique system that hosts two directly imaged protoplanets.


2021-06-11
15:00
High resolution observations of protoplanetary disk structures
Myriam Benisty (IPAG)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract

Recent observing campaigns have revealed a great diversity in exoplanetary systems whose origin is yet to be understood. How and when planets form, and how they evolve and interact with their birth environment, the protoplanetary disks, are major open questions. Protoplanetary disks evolve and dissipate rapidly while planets are forming, implying a direct feedback between the processes of planet formation and disk evolution. These mechanisms leave clear imprints on the disk structure that can be directly observed. In the past few years, high-resolution observations of protoplanetary disks obtained in the infrared and in the millimeter regime have led to exquisite images and shown that small scale structures are ubiquitous in protoplanetary disks. I will present recent observational results on protoplanetary disks obtained with VLTI, VLT/SPHERE and ALMA, that allow to probe the disk structure and the dynamics of solids, and in particular, in the so far unique system that hosts two directly imaged protoplanets.


2021-06-11
15:00
High resolution observations of protoplanetary disk structures
Myriam Benisty (IPAG)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract

Recent observing campaigns have revealed a great diversity in exoplanetary systems whose origin is yet to be understood. How and when planets form, and how they evolve and interact with their birth environment, the protoplanetary disks, are major open questions. Protoplanetary disks evolve and dissipate rapidly while planets are forming, implying a direct feedback between the processes of planet formation and disk evolution. These mechanisms leave clear imprints on the disk structure that can be directly observed. In the past few years, high-resolution observations of protoplanetary disks obtained in the infrared and in the millimeter regime have led to exquisite images and shown that small scale structures are ubiquitous in protoplanetary disks. I will present recent observational results on protoplanetary disks obtained with VLTI, VLT/SPHERE and ALMA, that allow to probe the disk structure and the dynamics of solids, and in particular, in the so far unique system that hosts two directly imaged protoplanets.


2021-06-11
15:00
High resolution observations of protoplanetary disk structures
Myriam Benisty (IPAG)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract

Recent observing campaigns have revealed a great diversity in exoplanetary systems whose origin is yet to be understood. How and when planets form, and how they evolve and interact with their birth environment, the protoplanetary disks, are major open questions. Protoplanetary disks evolve and dissipate rapidly while planets are forming, implying a direct feedback between the processes of planet formation and disk evolution. These mechanisms leave clear imprints on the disk structure that can be directly observed. In the past few years, high-resolution observations of protoplanetary disks obtained in the infrared and in the millimeter regime have led to exquisite images and shown that small scale structures are ubiquitous in protoplanetary disks. I will present recent observational results on protoplanetary disks obtained with VLTI, VLT/SPHERE and ALMA, that allow to probe the disk structure and the dynamics of solids, and in particular, in the so far unique system that hosts two directly imaged protoplanets.


2021-06-04
15:00
Probing the Growth of Black Holes at the Limit of Large Telescopes
Felix Bosco (MPIA)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
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Abstract
In recent years, more and more observational evidence for the existence of black holes (BHs) was gathered. This was acknowledged by the Nobel prizes in 2017 and 2020, for the detection of gravitational waves, emitted by merging BH binaries, and for the discovery of Sag A* as the central supermassive BH (SMBH) in the Milky Way. Still, direct kinematical measurements of BH masses require to resolve the sphere of influence at sub-milliarcsecond scales. In this talk, I present. two novel observational approaches that exhaust the resolution limit of modern large telescopes in order to allow for tighter constraints on masses and growth mechanisms of BHs:

The first approach applies holographic speckle imaging techniques to near-infrared images after partial atmospheric turbulence correction. Based on simulations and observational data, we have shown that the combination of techniques recovers the diffraction limit of 8 m-class telescopes for stars too faint for classical speckle imaging. This approach will allow for tracing BHs directly via stellar kinematics.

The second technique uses the spectroastrometric signal of the quasar broad emission line region in order to constrain its geometric and kinematic structure. We extract this signal from adaptive-optics-assisted near-infrared spectroscopy with an 8m telescope and carefully study the uncertainties. The comparison of the data to our model allows us to report on the first tentative detection of the spectroastrometric signal of a luminous quasar and thereby for constraining its BH mass, the first direct measurement beyond a redshift of z = 2 and out of the detection range of reverberation mapping or optical interferometry.

2021-06-04
15:00
Probing the Growth of Black Holes at the Limit of Large Telescopes
Felix Bosco (MPIA)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
Show/hide abstract

Abstract
In recent years, more and more observational evidence for the existence of black holes (BHs) was gathered. This was acknowledged by the Nobel prizes in 2017 and 2020, for the detection of gravitational waves, emitted by merging BH binaries, and for the discovery of Sag A* as the central supermassive BH (SMBH) in the Milky Way. Still, direct kinematical measurements of BH masses require to resolve the sphere of influence at sub-milliarcsecond scales. In this talk, I present. two novel observational approaches that exhaust the resolution limit of modern large telescopes in order to allow for tighter constraints on masses and growth mechanisms of BHs:

The first approach applies holographic speckle imaging techniques to near-infrared images after partial atmospheric turbulence correction. Based on simulations and observational data, we have shown that the combination of techniques recovers the diffraction limit of 8 m-class telescopes for stars too faint for classical speckle imaging. This approach will allow for tracing BHs directly via stellar kinematics.

The second technique uses the spectroastrometric signal of the quasar broad emission line region in order to constrain its geometric and kinematic structure. We extract this signal from adaptive-optics-assisted near-infrared spectroscopy with an 8m telescope and carefully study the uncertainties. The comparison of the data to our model allows us to report on the first tentative detection of the spectroastrometric signal of a luminous quasar and thereby for constraining its BH mass, the first direct measurement beyond a redshift of z = 2 and out of the detection range of reverberation mapping or optical interferometry.

2021-06-04
15:00
Probing the Growth of Black Holes at the Limit of Large Telescopes
Felix Bosco (MPIA)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
Show/hide abstract

Abstract
In recent years, more and more observational evidence for the existence of black holes (BHs) was gathered. This was acknowledged by the Nobel prizes in 2017 and 2020, for the detection of gravitational waves, emitted by merging BH binaries, and for the discovery of Sag A* as the central supermassive BH (SMBH) in the Milky Way. Still, direct kinematical measurements of BH masses require to resolve the sphere of influence at sub-milliarcsecond scales. In this talk, I present. two novel observational approaches that exhaust the resolution limit of modern large telescopes in order to allow for tighter constraints on masses and growth mechanisms of BHs:

The first approach applies holographic speckle imaging techniques to near-infrared images after partial atmospheric turbulence correction. Based on simulations and observational data, we have shown that the combination of techniques recovers the diffraction limit of 8 m-class telescopes for stars too faint for classical speckle imaging. This approach will allow for tracing BHs directly via stellar kinematics.

The second technique uses the spectroastrometric signal of the quasar broad emission line region in order to constrain its geometric and kinematic structure. We extract this signal from adaptive-optics-assisted near-infrared spectroscopy with an 8m telescope and carefully study the uncertainties. The comparison of the data to our model allows us to report on the first tentative detection of the spectroastrometric signal of a luminous quasar and thereby for constraining its BH mass, the first direct measurement beyond a redshift of z = 2 and out of the detection range of reverberation mapping or optical interferometry.

2021-06-04
15:00
Probing the Growth of Black Holes at the Limit of Large Telescopes
Felix Bosco (MPIA)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
Show/hide abstract

Abstract
In recent years, more and more observational evidence for the existence of black holes (BHs) was gathered. This was acknowledged by the Nobel prizes in 2017 and 2020, for the detection of gravitational waves, emitted by merging BH binaries, and for the discovery of Sag A* as the central supermassive BH (SMBH) in the Milky Way. Still, direct kinematical measurements of BH masses require to resolve the sphere of influence at sub-milliarcsecond scales. In this talk, I present. two novel observational approaches that exhaust the resolution limit of modern large telescopes in order to allow for tighter constraints on masses and growth mechanisms of BHs:

The first approach applies holographic speckle imaging techniques to near-infrared images after partial atmospheric turbulence correction. Based on simulations and observational data, we have shown that the combination of techniques recovers the diffraction limit of 8 m-class telescopes for stars too faint for classical speckle imaging. This approach will allow for tracing BHs directly via stellar kinematics.

The second technique uses the spectroastrometric signal of the quasar broad emission line region in order to constrain its geometric and kinematic structure. We extract this signal from adaptive-optics-assisted near-infrared spectroscopy with an 8m telescope and carefully study the uncertainties. The comparison of the data to our model allows us to report on the first tentative detection of the spectroastrometric signal of a luminous quasar and thereby for constraining its BH mass, the first direct measurement beyond a redshift of z = 2 and out of the detection range of reverberation mapping or optical interferometry.

2021-05-28
15:00
Better together: binary stars as probes of stellar evolution and fundamental physics
Kareem Al-Badry (Berkeley,MPIA)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
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Abstract


Binary stars are foundational to modern astrophysics. They underpin precision measurements of stellar structure, age, and composition\; they provide the most stringent tests of general relativity, they make possible the study of faint and rare objects such as black holes and neutron stars, and they are the progenitors of gravitational wave sources. The components of binaries often interact, dramatically changing their evolution and giving rise to a spectacular zoo of astrophysical phenomenology. To understand stars -- particularly massive stars -- it is necessary to understand binaries. Large-scale stellar surveys such as Gaia, TESS, and SDSS-V are transforming the binary field, making possible both comprehensive population demographics and the discovery of rare objects. I will discuss new insights gleaned from surveys in recent years, including the creation of stripped-envelope stars following binary mass transfer, the formation of equal-mass "twin" binaries in circumbinary disks, the metallicity-dependence of the binary fraction, and the discovery of planets in binaries. I will focus in particular on the search for dormant stellar-mass black holes in binaries, discussing recent candidates and the path forward to characterizing the detached black hole population.

2021-05-28
15:00
Better together: binary stars as probes of stellar evolution and fundamental physics
Kareem Al-Badry (Berkeley,MPIA)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
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Abstract


Binary stars are foundational to modern astrophysics. They underpin precision measurements of stellar structure, age, and composition\; they provide the most stringent tests of general relativity, they make possible the study of faint and rare objects such as black holes and neutron stars, and they are the progenitors of gravitational wave sources. The components of binaries often interact, dramatically changing their evolution and giving rise to a spectacular zoo of astrophysical phenomenology. To understand stars -- particularly massive stars -- it is necessary to understand binaries. Large-scale stellar surveys such as Gaia, TESS, and SDSS-V are transforming the binary field, making possible both comprehensive population demographics and the discovery of rare objects. I will discuss new insights gleaned from surveys in recent years, including the creation of stripped-envelope stars following binary mass transfer, the formation of equal-mass "twin" binaries in circumbinary disks, the metallicity-dependence of the binary fraction, and the discovery of planets in binaries. I will focus in particular on the search for dormant stellar-mass black holes in binaries, discussing recent candidates and the path forward to characterizing the detached black hole population.

2021-05-28
15:00
Better together: binary stars as probes of stellar evolution and fundamental physics
Kareem Al-Badry (Berkeley,MPIA)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
Show/hide abstract

Abstract


Binary stars are foundational to modern astrophysics. They underpin precision measurements of stellar structure, age, and composition\; they provide the most stringent tests of general relativity, they make possible the study of faint and rare objects such as black holes and neutron stars, and they are the progenitors of gravitational wave sources. The components of binaries often interact, dramatically changing their evolution and giving rise to a spectacular zoo of astrophysical phenomenology. To understand stars -- particularly massive stars -- it is necessary to understand binaries. Large-scale stellar surveys such as Gaia, TESS, and SDSS-V are transforming the binary field, making possible both comprehensive population demographics and the discovery of rare objects. I will discuss new insights gleaned from surveys in recent years, including the creation of stripped-envelope stars following binary mass transfer, the formation of equal-mass "twin" binaries in circumbinary disks, the metallicity-dependence of the binary fraction, and the discovery of planets in binaries. I will focus in particular on the search for dormant stellar-mass black holes in binaries, discussing recent candidates and the path forward to characterizing the detached black hole population.

2021-05-28
15:00
Better together: binary stars as probes of stellar evolution and fundamental physics
Kareem Al-Badry (Berkeley,MPIA)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
Show/hide abstract

Abstract


Binary stars are foundational to modern astrophysics. They underpin precision measurements of stellar structure, age, and composition\; they provide the most stringent tests of general relativity, they make possible the study of faint and rare objects such as black holes and neutron stars, and they are the progenitors of gravitational wave sources. The components of binaries often interact, dramatically changing their evolution and giving rise to a spectacular zoo of astrophysical phenomenology. To understand stars -- particularly massive stars -- it is necessary to understand binaries. Large-scale stellar surveys such as Gaia, TESS, and SDSS-V are transforming the binary field, making possible both comprehensive population demographics and the discovery of rare objects. I will discuss new insights gleaned from surveys in recent years, including the creation of stripped-envelope stars following binary mass transfer, the formation of equal-mass "twin" binaries in circumbinary disks, the metallicity-dependence of the binary fraction, and the discovery of planets in binaries. I will focus in particular on the search for dormant stellar-mass black holes in binaries, discussing recent candidates and the path forward to characterizing the detached black hole population.

2021-05-21
15:00
Studying quasar microlensing with robotic telescopes
Robert Schmidt (ZAH/ARI)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
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Abstract
Gravitationally lensed quasars are illusions where a background quasar is observed several times due to the light deflection by a foreground galaxy. Microlensing along the individual light paths causes variability of the quasar images, which lets us draw conclusions on the microlensing objects and the quasar engine. I sum up the state of the art and describe our monitoring program which uses the LCO robotic telescopes.

2021-05-21
15:00
Studying quasar microlensing with robotic telescopes
Robert Schmidt (ZAH/ARI)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
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Abstract
Gravitationally lensed quasars are illusions where a background quasar is observed several times due to the light deflection by a foreground galaxy. Microlensing along the individual light paths causes variability of the quasar images, which lets us draw conclusions on the microlensing objects and the quasar engine. I sum up the state of the art and describe our monitoring program which uses the LCO robotic telescopes.

2021-05-21
15:00
Studying quasar microlensing with robotic telescopes
Robert Schmidt (ZAH/ARI)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
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Abstract
Gravitationally lensed quasars are illusions where a background quasar is observed several times due to the light deflection by a foreground galaxy. Microlensing along the individual light paths causes variability of the quasar images, which lets us draw conclusions on the microlensing objects and the quasar engine. I sum up the state of the art and describe our monitoring program which uses the LCO robotic telescopes.

2021-05-21
15:00
Studying quasar microlensing with robotic telescopes
Robert Schmidt (ZAH/ARI)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
Show/hide abstract

Abstract
Gravitationally lensed quasars are illusions where a background quasar is observed several times due to the light deflection by a foreground galaxy. Microlensing along the individual light paths causes variability of the quasar images, which lets us draw conclusions on the microlensing objects and the quasar engine. I sum up the state of the art and describe our monitoring program which uses the LCO robotic telescopes.

2021-05-14
15:00
Knitting Together a New 3D View of our Milky Way Galaxy
Catherine Zucker (CfA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Until recently, much of our understanding of the 3D structure of our Milky Way was based on 2D observations of stars and dust, or spectral-line observations of gas. Distance measurements needed to turn the 2D sky into a 3D physical picture of the stars and interstellar clouds that form them were few and far between. In this talk, I will discuss how the rise of Gaia and large photometric surveys ? in combination with new data science and visualization techniques ? is quickly changing the landscape. In particular, I will show how 3D dust maps have received a huge distance resolution boost from Gaia and how 3D dust can be ?knitted? together with velocity information from gas and young stars to render new 3D spatial-kinematic views of our solar neighborhood. On small scales, I will present a new analysis of the 3D spatial topologies of local molecular clouds, linking the formation of a subset of these clouds to the expansion of a previously undiscovered feedback-driven superbubble. And on large scales, I will show how many of these clouds are connected into a 2.7-kpc-long undulating gaseous structure called the Radcliffe Wave, which redefines our understanding of the Local Arm nearby.

2021-05-14
15:00
Knitting Together a New 3D View of our Milky Way Galaxy
Catherine Zucker (CfA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Until recently, much of our understanding of the 3D structure of our Milky Way was based on 2D observations of stars and dust, or spectral-line observations of gas. Distance measurements needed to turn the 2D sky into a 3D physical picture of the stars and interstellar clouds that form them were few and far between. In this talk, I will discuss how the rise of Gaia and large photometric surveys ? in combination with new data science and visualization techniques ? is quickly changing the landscape. In particular, I will show how 3D dust maps have received a huge distance resolution boost from Gaia and how 3D dust can be ?knitted? together with velocity information from gas and young stars to render new 3D spatial-kinematic views of our solar neighborhood. On small scales, I will present a new analysis of the 3D spatial topologies of local molecular clouds, linking the formation of a subset of these clouds to the expansion of a previously undiscovered feedback-driven superbubble. And on large scales, I will show how many of these clouds are connected into a 2.7-kpc-long undulating gaseous structure called the Radcliffe Wave, which redefines our understanding of the Local Arm nearby.

2021-05-14
15:00
Knitting Together a New 3D View of our Milky Way Galaxy
Catherine Zucker (CfA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Until recently, much of our understanding of the 3D structure of our Milky Way was based on 2D observations of stars and dust, or spectral-line observations of gas. Distance measurements needed to turn the 2D sky into a 3D physical picture of the stars and interstellar clouds that form them were few and far between. In this talk, I will discuss how the rise of Gaia and large photometric surveys ? in combination with new data science and visualization techniques ? is quickly changing the landscape. In particular, I will show how 3D dust maps have received a huge distance resolution boost from Gaia and how 3D dust can be ?knitted? together with velocity information from gas and young stars to render new 3D spatial-kinematic views of our solar neighborhood. On small scales, I will present a new analysis of the 3D spatial topologies of local molecular clouds, linking the formation of a subset of these clouds to the expansion of a previously undiscovered feedback-driven superbubble. And on large scales, I will show how many of these clouds are connected into a 2.7-kpc-long undulating gaseous structure called the Radcliffe Wave, which redefines our understanding of the Local Arm nearby.

2021-05-07
15:00
Explaining the high accretion rates in transition disks
Matias Garate (MPIA)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
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Abstract
The origin of transition disks remains an unsolved puzzle in the process of planet formation, and this is mainly because of their seemingly contradictory properties. After all, how can we explain a population of disks that present large gaps that extend for tens of AUs, high accretion rates that are inconsistent with the inner disk lifetime, and bright luminosities that reveal a high content of millimeter sized grains, all at the same time? In this talk I will present our latest model of disk evolution, which includes both the effects of photoevaporative dispersal to explain the large gaps, and dead zones in the inner regions to explain the high accretion rates, and show that when these ingredients work together they can effectively reproduce the observed population of transition disk as a whole, covering the weak points that each models would have individually.

2021-05-07
15:00
Explaining the high accretion rates in transition disks
Matias Garate (MPIA)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
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Abstract
The origin of transition disks remains an unsolved puzzle in the process of planet formation, and this is mainly because of their seemingly contradictory properties. After all, how can we explain a population of disks that present large gaps that extend for tens of AUs, high accretion rates that are inconsistent with the inner disk lifetime, and bright luminosities that reveal a high content of millimeter sized grains, all at the same time? In this talk I will present our latest model of disk evolution, which includes both the effects of photoevaporative dispersal to explain the large gaps, and dead zones in the inner regions to explain the high accretion rates, and show that when these ingredients work together they can effectively reproduce the observed population of transition disk as a whole, covering the weak points that each models would have individually.

2021-05-07
15:00
Explaining the high accretion rates in transition disks
Matias Garate (MPIA)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
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Abstract
The origin of transition disks remains an unsolved puzzle in the process of planet formation, and this is mainly because of their seemingly contradictory properties. After all, how can we explain a population of disks that present large gaps that extend for tens of AUs, high accretion rates that are inconsistent with the inner disk lifetime, and bright luminosities that reveal a high content of millimeter sized grains, all at the same time? In this talk I will present our latest model of disk evolution, which includes both the effects of photoevaporative dispersal to explain the large gaps, and dead zones in the inner regions to explain the high accretion rates, and show that when these ingredients work together they can effectively reproduce the observed population of transition disk as a whole, covering the weak points that each models would have individually.

2021-04-30
15:00
PHANGS-ALMA : Our First Cloud-Scale Survey of Molecular Gas
Adam Leroy (OSU)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
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Abstract

I will present "PHANGS-ALMA" a multi-cycle ALMA survey of 90 nearby galaxies built around an ALMA Large Program. Leveraging ALMA's amazing combination of resolution, sensitivity, and mapping speed, PHANGS-ALMA mapped the CO 2-1 emission, our basic tracer of molecular gas in galaxies, at 1" = 50-150 pc resolution scales across essentially all accessible very nearby star-forming galaxies. This resolution represents a major leap forward because, for the first time, PHANGS-ALMA resolves the molecular gas across whole galaxies into individual star-forming molecular clouds, giving access to the demographics, life cycle, and properties of tens of thousands of molecular clouds across a representative set of z=0 galaxies. I will give an overview of the motivation and execution of the survey and then highlight results on each of these key topics - demographics, life cycles, and star formation properties of clouds - from the PHANGS team.

2021-04-30
15:00
PHANGS-ALMA : Our First Cloud-Scale Survey of Molecular Gas
Adam Leroy (OSU)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
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Abstract

I will present "PHANGS-ALMA" a multi-cycle ALMA survey of 90 nearby galaxies built around an ALMA Large Program. Leveraging ALMA's amazing combination of resolution, sensitivity, and mapping speed, PHANGS-ALMA mapped the CO 2-1 emission, our basic tracer of molecular gas in galaxies, at 1" = 50-150 pc resolution scales across essentially all accessible very nearby star-forming galaxies. This resolution represents a major leap forward because, for the first time, PHANGS-ALMA resolves the molecular gas across whole galaxies into individual star-forming molecular clouds, giving access to the demographics, life cycle, and properties of tens of thousands of molecular clouds across a representative set of z=0 galaxies. I will give an overview of the motivation and execution of the survey and then highlight results on each of these key topics - demographics, life cycles, and star formation properties of clouds - from the PHANGS team.

2021-04-30
15:00
PHANGS-ALMA : Our First Cloud-Scale Survey of Molecular Gas
Adam Leroy (OSU)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
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Abstract

I will present "PHANGS-ALMA" a multi-cycle ALMA survey of 90 nearby galaxies built around an ALMA Large Program. Leveraging ALMA's amazing combination of resolution, sensitivity, and mapping speed, PHANGS-ALMA mapped the CO 2-1 emission, our basic tracer of molecular gas in galaxies, at 1" = 50-150 pc resolution scales across essentially all accessible very nearby star-forming galaxies. This resolution represents a major leap forward because, for the first time, PHANGS-ALMA resolves the molecular gas across whole galaxies into individual star-forming molecular clouds, giving access to the demographics, life cycle, and properties of tens of thousands of molecular clouds across a representative set of z=0 galaxies. I will give an overview of the motivation and execution of the survey and then highlight results on each of these key topics - demographics, life cycles, and star formation properties of clouds - from the PHANGS team.

2021-04-23
15:00
Finding the sources of reionisation
Romain Meyer (MPIA)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
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Abstract
The epoch of (hydrogen) reionisation, during which hydrogen in the intergalactic medium was reionised by the first galaxies, was the last global phase transition of the Universe and ended about a billion years after the Big Bang. The last two decades have seen enormous progress in our understanding of cosmic reionisation. Whilst the timing and topology of reionisation are being constrained ever more precisely, the sources emitting the necessary ionising photons have however remained elusive. In this talk, I will discuss new measurements of the ionising output of high-redshift galaxies aiming to uncover which galaxies are responsible for reionisation and what this might imply for galaxy evolution.

2021-04-23
15:00
Finding the sources of reionisation
Romain Meyer (MPIA)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
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Abstract
The epoch of (hydrogen) reionisation, during which hydrogen in the intergalactic medium was reionised by the first galaxies, was the last global phase transition of the Universe and ended about a billion years after the Big Bang. The last two decades have seen enormous progress in our understanding of cosmic reionisation. Whilst the timing and topology of reionisation are being constrained ever more precisely, the sources emitting the necessary ionising photons have however remained elusive. In this talk, I will discuss new measurements of the ionising output of high-redshift galaxies aiming to uncover which galaxies are responsible for reionisation and what this might imply for galaxy evolution.

2021-04-23
15:00
Finding the sources of reionisation
Romain Meyer (MPIA)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
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Abstract
The epoch of (hydrogen) reionisation, during which hydrogen in the intergalactic medium was reionised by the first galaxies, was the last global phase transition of the Universe and ended about a billion years after the Big Bang. The last two decades have seen enormous progress in our understanding of cosmic reionisation. Whilst the timing and topology of reionisation are being constrained ever more precisely, the sources emitting the necessary ionising photons have however remained elusive. In this talk, I will discuss new measurements of the ionising output of high-redshift galaxies aiming to uncover which galaxies are responsible for reionisation and what this might imply for galaxy evolution.

2021-04-16
15:00
Mapping the assembly of discs via their chemical abundances
Francesco Belfiori (INAF-Arcetri)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
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Abstract
The last five years have seen enormous progress in mapping local galaxies with integral field spectroscopy. Large surveys, like CALIFA, SAMI and MaNGA, have now provided us with a detailed view of star formation and chemical enrichment across the Hubble sequence at z=0. In this talk I will review what these observations have taught us about the chemo-dynamics of local disc galaxies, focusing on metallicity gradients as probes for disc assembly.

Moving beyond metallicity gradients requires mapping of ISM at the ?cloud-scale?, enabling us to resolve individual HII regions from the diffuse ionised gas background. I will present early results from the PHANGS-MUSE survey, a large program with the MUSE integral field spectrograph, which has recently obtained the first systematic view of the ionised ISM at the cloud scale (<\;50 pc) across a variety of local environments in a sample of 19 nearby galaxies. This dataset is allowing us to take the first step towards drawing a complete picture of the baryon cycle, and bridging the gap between the Milky Way and the extragalactic view of star formation and chemical enrichment.

2021-04-16
15:00
Mapping the assembly of discs via their chemical abundances
Francesco Belfiori (INAF-Arcetri)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
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Abstract
The last five years have seen enormous progress in mapping local galaxies with integral field spectroscopy. Large surveys, like CALIFA, SAMI and MaNGA, have now provided us with a detailed view of star formation and chemical enrichment across the Hubble sequence at z=0. In this talk I will review what these observations have taught us about the chemo-dynamics of local disc galaxies, focusing on metallicity gradients as probes for disc assembly.

Moving beyond metallicity gradients requires mapping of ISM at the ?cloud-scale?, enabling us to resolve individual HII regions from the diffuse ionised gas background. I will present early results from the PHANGS-MUSE survey, a large program with the MUSE integral field spectrograph, which has recently obtained the first systematic view of the ionised ISM at the cloud scale (<\;50 pc) across a variety of local environments in a sample of 19 nearby galaxies. This dataset is allowing us to take the first step towards drawing a complete picture of the baryon cycle, and bridging the gap between the Milky Way and the extragalactic view of star formation and chemical enrichment.

2021-04-16
15:00
Mapping the assembly of discs via their chemical abundances
Francesco Belfiori (INAF-Arcetri)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
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Abstract
The last five years have seen enormous progress in mapping local galaxies with integral field spectroscopy. Large surveys, like CALIFA, SAMI and MaNGA, have now provided us with a detailed view of star formation and chemical enrichment across the Hubble sequence at z=0. In this talk I will review what these observations have taught us about the chemo-dynamics of local disc galaxies, focusing on metallicity gradients as probes for disc assembly.

Moving beyond metallicity gradients requires mapping of ISM at the ?cloud-scale?, enabling us to resolve individual HII regions from the diffuse ionised gas background. I will present early results from the PHANGS-MUSE survey, a large program with the MUSE integral field spectrograph, which has recently obtained the first systematic view of the ionised ISM at the cloud scale (<\;50 pc) across a variety of local environments in a sample of 19 nearby galaxies. This dataset is allowing us to take the first step towards drawing a complete picture of the baryon cycle, and bridging the gap between the Milky Way and the extragalactic view of star formation and chemical enrichment.

2021-03-26
15:00
The Galactic centre told by its stellar population
Francisco Nogueras Lara (MPIA)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
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Abstract
The Galactic centre (GC) is the only galactic nucleus where we can resolve individual stars down to mili-parsec scales. Therefore, it constitutes a unique laboratory to study stellar nuclei and their role in the context of galaxy evolution. However, the high extinction and the extreme source crowding hamper the analysis of its stellar population and structure. In this talk, I will present the GALACTICNUCLEUS catalogue, a high angular resolution (~0.2'') photometric survey in the near infrared bands JHKs, that was specially designed to observe the GC. I will summarise our main results on the extinction analysis in the near infrared, the star formation history, and the distance to dark clouds in the central molecular zone.

2021-03-26
15:00
The Galactic centre told by its stellar population
Francisco Nogueras Lara (MPIA)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
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Abstract
The Galactic centre (GC) is the only galactic nucleus where we can resolve individual stars down to mili-parsec scales. Therefore, it constitutes a unique laboratory to study stellar nuclei and their role in the context of galaxy evolution. However, the high extinction and the extreme source crowding hamper the analysis of its stellar population and structure. In this talk, I will present the GALACTICNUCLEUS catalogue, a high angular resolution (~0.2'') photometric survey in the near infrared bands JHKs, that was specially designed to observe the GC. I will summarise our main results on the extinction analysis in the near infrared, the star formation history, and the distance to dark clouds in the central molecular zone.

2021-03-26
15:00
The Galactic centre told by its stellar population
Francisco Nogueras Lara (MPIA)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
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Abstract
The Galactic centre (GC) is the only galactic nucleus where we can resolve individual stars down to mili-parsec scales. Therefore, it constitutes a unique laboratory to study stellar nuclei and their role in the context of galaxy evolution. However, the high extinction and the extreme source crowding hamper the analysis of its stellar population and structure. In this talk, I will present the GALACTICNUCLEUS catalogue, a high angular resolution (~0.2'') photometric survey in the near infrared bands JHKs, that was specially designed to observe the GC. I will summarise our main results on the extinction analysis in the near infrared, the star formation history, and the distance to dark clouds in the central molecular zone.

2021-03-19
15:00
The inner regions of protoplanetary disks: an interferometric view
Rebeca Garcia-Lopez (Uni. Dublin/MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
A first step towards understanding planetary formation is the characterisation of the structure and evolution of protoplanetary discs. Although the large scale disc is understood in some detail, very little is known about the inner few au. In this region, dust grains sublimate, and accretion and ejection take place, affecting the entire disk structure and evolution.

In this talk, I will review the most recent findings on the structure of the innermost regions of protoplanetary disks. In particular, I will focus on the main characteristics of this inner region as probed through VLTI-GRAVITY observations of dust and gas tracers, such as the CO and HI Br gamma emission. Finally, I will show what is our progress on image reconstruction of the inner disk.

2021-03-19
15:00
The inner regions of protoplanetary disks: an interferometric view
Rebeca Garcia-Lopez (Uni. Dublin/MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
A first step towards understanding planetary formation is the characterisation of the structure and evolution of protoplanetary discs. Although the large scale disc is understood in some detail, very little is known about the inner few au. In this region, dust grains sublimate, and accretion and ejection take place, affecting the entire disk structure and evolution.

In this talk, I will review the most recent findings on the structure of the innermost regions of protoplanetary disks. In particular, I will focus on the main characteristics of this inner region as probed through VLTI-GRAVITY observations of dust and gas tracers, such as the CO and HI Br gamma emission. Finally, I will show what is our progress on image reconstruction of the inner disk.

2021-03-19
15:00
The inner regions of protoplanetary disks: an interferometric view
Rebeca Garcia-Lopez (Uni. Dublin/MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
A first step towards understanding planetary formation is the characterisation of the structure and evolution of protoplanetary discs. Although the large scale disc is understood in some detail, very little is known about the inner few au. In this region, dust grains sublimate, and accretion and ejection take place, affecting the entire disk structure and evolution.

In this talk, I will review the most recent findings on the structure of the innermost regions of protoplanetary disks. In particular, I will focus on the main characteristics of this inner region as probed through VLTI-GRAVITY observations of dust and gas tracers, such as the CO and HI Br gamma emission. Finally, I will show what is our progress on image reconstruction of the inner disk.

2021-03-12
15:00
Exploring the metal-poor inner Milky Way with the Pristine survey
Anke Arentsen (Strasbourg)
Königstuhl Kolloquium
Zoom,
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Abstract
Exploring the metal-poor inner Milky Way with the Pristine survey

Anke Arentsen (Strasbourg)

Old, metal-poor stars can teach us about the First Stars and about the early formation and evolution of the Milky Way. A prediction of simulations is that the fraction of metal-poor stars that are very old is highest towards the centres of galaxies: in their bulges. However, searching for metal-poor stars in the bulge region of the Milky Way faces many challenges, so much is unknown about the properties of the metal-poor inner Galaxy. In this talk, I will introduce the Pristine Inner Galaxy Survey (PIGS) which has reached unprecedented efficiency in finding very metal-poor stars in the Galactic bulge region. I will present recent PIGS results on the chemistry (focusing on carbon-enhanced metal-poor stars) and the kinematics of the metal-poor inner Galaxy, and discuss what they can teach us about this ancient component of the Milky Way. \;

2021-03-12
15:00
Exploring the metal-poor inner Milky Way with the Pristine survey
Anke Arentsen (Strasbourg)
Königstuhl Kolloquium
Zoom,
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Abstract
Exploring the metal-poor inner Milky Way with the Pristine survey

Anke Arentsen (Strasbourg)

Old, metal-poor stars can teach us about the First Stars and about the early formation and evolution of the Milky Way. A prediction of simulations is that the fraction of metal-poor stars that are very old is highest towards the centres of galaxies: in their bulges. However, searching for metal-poor stars in the bulge region of the Milky Way faces many challenges, so much is unknown about the properties of the metal-poor inner Galaxy. In this talk, I will introduce the Pristine Inner Galaxy Survey (PIGS) which has reached unprecedented efficiency in finding very metal-poor stars in the Galactic bulge region. I will present recent PIGS results on the chemistry (focusing on carbon-enhanced metal-poor stars) and the kinematics of the metal-poor inner Galaxy, and discuss what they can teach us about this ancient component of the Milky Way. \;

2021-03-12
15:00
Exploring the metal-poor inner Milky Way with the Pristine survey
Anke Arentsen (Strasbourg)
Königstuhl Kolloquium
Zoom,
Show/hide abstract

Abstract
Exploring the metal-poor inner Milky Way with the Pristine survey

Anke Arentsen (Strasbourg)

Old, metal-poor stars can teach us about the First Stars and about the early formation and evolution of the Milky Way. A prediction of simulations is that the fraction of metal-poor stars that are very old is highest towards the centres of galaxies: in their bulges. However, searching for metal-poor stars in the bulge region of the Milky Way faces many challenges, so much is unknown about the properties of the metal-poor inner Galaxy. In this talk, I will introduce the Pristine Inner Galaxy Survey (PIGS) which has reached unprecedented efficiency in finding very metal-poor stars in the Galactic bulge region. I will present recent PIGS results on the chemistry (focusing on carbon-enhanced metal-poor stars) and the kinematics of the metal-poor inner Galaxy, and discuss what they can teach us about this ancient component of the Milky Way. \;

2021-03-05
15:00
from the instrument to the data analysis.
Faustine Cantalloube (MPIA) on High-contrast imaging of exoplanets and circumstellar disks
Königstuhl Kolloquium
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Abstract
High-contrast imaging of exoplanets and circumstellar disks: from the instrument to the data analysis.

Faustine Cantalloube (MPIA)

High-contrast imaging is one of the most challenging observational techniques in the visible infrared. It requires the best adaptive optics systems installed on the largest ground-based telescopes, advanced coronagraphs design, and dedicated image processing techniques. Thanks to the second generation of high-contrast instruments, such as VLT/SPHERE partially developed at MPIA, we now understand subtle effects stemming from the atmospheric turbulence and interacting all the way through the instrument, which drive the final performance of the instrument. This knowledge turns out to be of great interest in the context of the design of the future 40-m class telescopes instrument suite. In this talk, I will give an overview of exoplanet imaging from an instrumental perspective.

2021-03-05
15:00
from the instrument to the data analysis.
Faustine Cantalloube (MPIA) on High-contrast imaging of exoplanets and circumstellar disks
Königstuhl Kolloquium
Zoom,
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Abstract
High-contrast imaging of exoplanets and circumstellar disks: from the instrument to the data analysis.

Faustine Cantalloube (MPIA)

High-contrast imaging is one of the most challenging observational techniques in the visible infrared. It requires the best adaptive optics systems installed on the largest ground-based telescopes, advanced coronagraphs design, and dedicated image processing techniques. Thanks to the second generation of high-contrast instruments, such as VLT/SPHERE partially developed at MPIA, we now understand subtle effects stemming from the atmospheric turbulence and interacting all the way through the instrument, which drive the final performance of the instrument. This knowledge turns out to be of great interest in the context of the design of the future 40-m class telescopes instrument suite. In this talk, I will give an overview of exoplanet imaging from an instrumental perspective.

2021-03-05
15:00
from the instrument to the data analysis.
Faustine Cantalloube (MPIA) on High-contrast imaging of exoplanets and circumstellar disks
Königstuhl Kolloquium
Zoom,
Show/hide abstract

Abstract
High-contrast imaging of exoplanets and circumstellar disks: from the instrument to the data analysis.

Faustine Cantalloube (MPIA)

High-contrast imaging is one of the most challenging observational techniques in the visible infrared. It requires the best adaptive optics systems installed on the largest ground-based telescopes, advanced coronagraphs design, and dedicated image processing techniques. Thanks to the second generation of high-contrast instruments, such as VLT/SPHERE partially developed at MPIA, we now understand subtle effects stemming from the atmospheric turbulence and interacting all the way through the instrument, which drive the final performance of the instrument. This knowledge turns out to be of great interest in the context of the design of the future 40-m class telescopes instrument suite. In this talk, I will give an overview of exoplanet imaging from an instrumental perspective.

2021-02-19
15:00
Into the abyss - How the deep atmosphere influences observables in extrasolar planets
Ludmila Carone (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Exoplanet atmosphere studies are becoming more detailed with advances in models and observational facilities and methods. One particular aspect in exoplanet atmosphere science is becoming more and more important with more detailed data: the connection between the (3D) atmosphere of extrasolar planets and their interior.

Here, it is the optically thick atmosphere (1000 bar >\; p >\;1 bar) which provides a boundary layer between deeper processes and the observable atmosphere: Temperature and heat sources, composition, deep winds, magnetic field coupling ... all of these can shape the flow, temperature structure and chemistry in higher parts of the exoplanet atmospheres.

In this talk, I will given an overview of the so far recognized interior - exoplanet connections and how to diagnose these with current and upcoming facilities. I will show that ultra hot Jupiters and some key hot Jupiter planets will be particularly interesting to investigate for interior effects. And I will show that the atmosphere-interior connection becomes even more important and multi-faceted when going to smaller and smaller planets. Thus, understanding the influence of the interior in the currently most readily characterizable exoplanets is a pressing need.

2021-02-19
15:00
Into the abyss - How the deep atmosphere influences observables in extrasolar planets
Ludmila Carone (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Exoplanet atmosphere studies are becoming more detailed with advances in models and observational facilities and methods. One particular aspect in exoplanet atmosphere science is becoming more and more important with more detailed data: the connection between the (3D) atmosphere of extrasolar planets and their interior.

Here, it is the optically thick atmosphere (1000 bar >\; p >\;1 bar) which provides a boundary layer between deeper processes and the observable atmosphere: Temperature and heat sources, composition, deep winds, magnetic field coupling ... all of these can shape the flow, temperature structure and chemistry in higher parts of the exoplanet atmospheres.

In this talk, I will given an overview of the so far recognized interior - exoplanet connections and how to diagnose these with current and upcoming facilities. I will show that ultra hot Jupiters and some key hot Jupiter planets will be particularly interesting to investigate for interior effects. And I will show that the atmosphere-interior connection becomes even more important and multi-faceted when going to smaller and smaller planets. Thus, understanding the influence of the interior in the currently most readily characterizable exoplanets is a pressing need.

2021-02-19
15:00
Into the abyss - How the deep atmosphere influences observables in extrasolar planets
Ludmila Carone (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
Show/hide abstract

Abstract
Exoplanet atmosphere studies are becoming more detailed with advances in models and observational facilities and methods. One particular aspect in exoplanet atmosphere science is becoming more and more important with more detailed data: the connection between the (3D) atmosphere of extrasolar planets and their interior.

Here, it is the optically thick atmosphere (1000 bar >\; p >\;1 bar) which provides a boundary layer between deeper processes and the observable atmosphere: Temperature and heat sources, composition, deep winds, magnetic field coupling ... all of these can shape the flow, temperature structure and chemistry in higher parts of the exoplanet atmospheres.

In this talk, I will given an overview of the so far recognized interior - exoplanet connections and how to diagnose these with current and upcoming facilities. I will show that ultra hot Jupiters and some key hot Jupiter planets will be particularly interesting to investigate for interior effects. And I will show that the atmosphere-interior connection becomes even more important and multi-faceted when going to smaller and smaller planets. Thus, understanding the influence of the interior in the currently most readily characterizable exoplanets is a pressing need.

2021-02-12
15:00
Observational signatures of AGN feedback across cosmic time
Dominika Wylezalek (ZAH/ARI)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
AGN feedback is now widely considered to be one of the main drivers in regulating the growth of massive galaxies. In my talk I will describe several efforts to understand the power, reach and impact of AGN feedback processes. Using SDSS-IV MaNGA at low-z, we find significant evidence for AGN signatures even in low-luminosity AGN. Using molecular gas as a tracer, we are investigating if / how feedback may impact and quench galaxies at low-z. At higher redshift, we find that outflows can indeed suppress star formation in their hosts, consistent with the AGN having a 'negative' impact. However, both star formation and quasar activity peak at z ~ 2-3 where AGN are expected to impact the build-up of stellar mass the most. Our team recently discovered a unique population of luminous high-z quasars (ERQs) with extreme outflow properties. At the same time, more and more exotic AGN populations with extreme signatures are being discovered at that redshift. These populations are ideal to obtain a census of the overall mass and energy budget of both outflow and infall/feeding from the CGM, an essential requirement to probe the detailed and full feedback loop. I will present recent efforts in our group to characterise feedback processes in powerful AGN on CGM scales at and near cosmic noon.

Finally, I will also introduce the JWST ERS Program "Q3D" which will study the impact of three carefully selected luminous quasars on their hosts. Our program will serve as a pathfinder for JWST science investigations in IFU mode.

2021-02-12
15:00
TBA
Dominika Wylezalek (ZAH/ARI)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBA

2021-02-05
15:00
Gaia & the fingerprints of the Galactic bar ? a dynamical Milkay Way mystery
Wilma Trick (MPA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBA

2021-02-05
15:00
Gaia & the fingerprints of the Galactic bar ? a dynamical Milky Way mystery
Wilma Trick (MPA)
Königstuhl Kolloquium
Zoom,
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Abstract

The Milky Way's disk around the Sun is interspersed by 7 streams of stars, amongst them the famous "Hercules", "Sirius", and "Hyades" moving groups. These streaming motions are caused by some powerful perturber. Suspects are the spiral arms, satellites, and/or the Galactic bar. So far, the true culprit has been notoriously elusive.

This talk shows how stars whose orbits are in resonance with the Galactic bar exhibit distinctive patterns in action-angle space. Based on these fingerprints, the exquisite Gaia data narrows down the search for the bar's Outer Lindblad Resonance (OLR) to two likely candidates: the "Hat" and the "Sirius" moving groups.

Finally pinning down the true OLR (and therefore the pattern speed of the Galactic bar) will be a milestone in uncovering the Milky Way's structure and evolution.


2021-01-29
15:00
TBA
Sarah Bosman (MPIA)
Königstuhl Kolloquium
zoom,
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Abstract
Beyond the Lyman-? forest: Understanding the end stages of Reionization

Hydrogen reionization is a crucial period during the Universe's history during which the first galaxies drive a global phase transition signaling the end of the Cosmic Dark Ages. Our observational view of reionization has changed drastically since Planck measurements pushed the timing of the process to later times, and in reach of direct observation through quasar spectroscopy. Ironically, the increase in observational data has raised more questions than it has answered. The timing of the end of reionization, as well as its morphology and the processes driving its end stages, are being hotly debated. I will review our current understanding of reionization's end stages, and present preliminary results from the XQR-30 collaboration: a 248-hour Large Program that is increasing the number of high-quality quasar spectroscopy during reionization four-fold. New developments are happening very quickly and offering the first solid insights into the properties of early galaxies driving reionization during the first billion years.

2021-01-29
15:00
TBA
Sarah Bosman (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBA

2021-01-22
15:00
CARMENES, the exoplanet finder: Uncovering nearby exoplanet systems with precision radial velocity measurements
Trifon Trifonov (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
CARMENES is a high-resolution optical and near-infrared spectrograph(s) mounted at the 3.6m telescope in Calar Alto, Spain. The CARMENES exoplanet survey began in 2016, targeting over 350 nearby M-dwarf stars. Since then, CARMENES has proven to be one of the most effective Radial Velocity (RV) exoplanet finders currently in operation. I will briefly present the CARMENES-GTO Doppler survey, its scientific goals, and I will focus on some of the exciting CARMENES-GTO exoplanet discoveries. I will show that CARMENES is fully capable of discovering complex multiple-planet systems around late M-dwarf stars, which cannot be studied by other instruments. I will reveal the powerful synergy between CARMENES and the Transiting Exoplanet Survey Satellite (TESS), leading to a dozen exoplanet discoveries. One of the most exciting CARMENES discoveries, confirmed by TESS, is a nearby transiting rocky exoplanet that will be a prime target for atmospheric investigation and characterization with the JWST. The precise orbital determination based on CARMENES precision RVs is vital for probing the planetary formation mechanisms and evolution scenarios around low-mass stars and in general.

2021-01-22
15:00
TBA
Trifon Trifonov (MPIA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBA

2021-01-15
15:00
Star formation and its quenching: insights from radio continuum and multiwavelength surveys
Sarah Leslie (Leiden)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
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Abstract

There are two main populations of galaxies in the universe, those forming stars and those no longer forming stars (quiescent). Explaining the quiescent population requires poorly constrained mechanisms referred to as ''quenching'' to interrupt the star formation process. Radio source counts are dominated by AGN at high flux densities and star-forming galaxies at low flux densities. With contemporary interferometers like ASKAP, MeerKAT/MIGHTEE, and LOFAR, we are starting to survey wide areas at unprecedented depths, detecting millions of normal star-forming galaxies and low-luminosity AGN out to high redshift. In this talk, I will focus on (1) new results with LOFAR and VLA on calibrating the radio -- SFR relation and its application as a dust unbiased tracer of star formation, and (2) recent work using MaNGA and LOFAR to investigate AGN feedback in the local universe.



Frithjof Brauer Memorial Award talk

2021-01-15
15:00
Brauer Award talk
Sarah Leslie (Leiden)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
TBD

2021-01-08
15:00
Connecting the dots: Numerical models of AGN and their particle acceleration
F. Spanier (ITA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Active Galactic Nuclei are an interesting source not only for photons in a very wide energy range, but also for cosmic rays and neutrinos. The emission of these different messengers is most likely connected to each other. To understand the physics behind AGN, emission models have to be constructed. Nowadays observational data is available from radio frequencies to TeV energies and neutrino observatories like IceCUBE may provide ultra-high energy neutrino counts. Unfortunately long-term simultaneous multi-wavelength observations are still scarce. I will present results from time-dependent and spatially resolved AGN emission models that allow for a self-consistent treatment of emission and particle acceleration within AGN. These models may help to distinguish different emission processes using the timing of lightcurves in separate energy bands. But they may also provide answers to questions like "What is the shape of an AGN jet?" or "Is there really one neutrino per one high-energy photon?"

2021-01-08
15:00
Connecting the dots: Numerical models of AGN and their particle acceleration
F. Spanier (ITA)
Königstuhl Kolloquium
Max-Planck-Institut für Astronomie, Level 3 Lecture Hall (301)
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Abstract
Active Galactic Nuclei are an interesting source not only for photons in a very wide energy range, but also for cosmic rays and neutrinos. The emission of these different messengers is most likely connected to each other. To understand the physics behind AGN, emission models have to be constructed. Nowadays observational data is available from radio frequencies to TeV energies and neutrino observatories like IceCUBE may provide ultra-high energy neutrino counts. Unfortunately long-term simultaneous multi-wavelength observations are still scarce. I will present results from time-dependent and spatially resolved AGN emission models that allow for a self-consistent treatment of emission and particle acceleration within AGN. These models may help to distinguish different emission processes using the timing of lightcurves in separate energy bands. But they may also provide answers to questions like "What is the shape of an AGN jet?" or "Is there really one neutrino per one high-energy photon?"

2020-12-18
15:00
Big Steps Toward Small Words: Exoplanet Atmosphere Characterization of Sub-Neptunes and Super-Earths
Laura Kreidberg (MPIA)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
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Abstract
Planets in between the size of Earth and Neptune are one of the dominant outcomes of planet formation. These worlds have no analogue in the Solar System, and their existence gives rise to many questions: what is their typical bulk composition? how do they form? what are their climates like? To address these questions, we turn to atmosphere characterization, which can provide a wealth of additional information about the planets beyond their masses and radii. In this talk, I will share new results from Hubble and Spitzer observational campaigns focused on small planet atmospheres, including (1) a search for demographic trends in the cloud properties and composition of sub-Neptunes, and (2) searches for an atmosphere on two hot rocky super-Earths.

2020-12-18
15:00
Big Steps Toward Small Words: Exoplanet Atmosphere Characterization of Sub-Neptunes and Super-Earths
Laura Kreidberg (MPIA)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
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Abstract
Planets in between the size of Earth and Neptune are one of the dominant outcomes of planet formation. These worlds have no analogue in the Solar System, and their existence gives rise to many questions: what is their typical bulk composition? how do they form? what are their climates like? To address these questions, we turn to atmosphere characterization, which can provide a wealth of additional information about the planets beyond their masses and radii. In this talk, I will share new results from Hubble and Spitzer observational campaigns focused on small planet atmospheres, including (1) a search for demographic trends in the cloud properties and composition of sub-Neptunes, and (2) searches for an atmosphere on two hot rocky super-Earths.

2020-12-11
15:00
Stellar clustering connecting the formation and evolution of galaxies to the formation and evolution of us
Diederik Kruijssen (Heidelberg University)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
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Abstract
The clustered nature of star formation leaves a long-term imprint on galaxies, stars, and planets. At young ages, stellar clustering subdivides galaxies into individual building blocks undergoing vigorous, feedback-driven life cycles that vary with the galactic environment. These units structure the interstellar medium spatially, dynamically and chemically, and collectively define how galaxies form stars. At old ages, the relics of clustered star formation persist as ancient globular clusters, which hold a wealth of information allowing us to reconstruct the assembly histories of galaxies, culminating in the reconstruction of the Milky Way's merger tree. Towards smaller scales, stellar clustering has a measurable impact on the evolution of protoplanetary discs, the architectures of planetary systems, and the properties of planets themselves. I will discuss how this web of physical processes across a hierarchy of scales defines the cosmic ecosystem that we live in, and demonstrate that stellar clustering is at its focal point.

2020-12-11
15:00
Stellar clustering connecting the formation and evolution of galaxies to the formation and evolution of us
Diederik Kruijssen (Heidelberg University)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
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Abstract
The clustered nature of star formation leaves a long-term imprint on galaxies, stars, and planets. At young ages, stellar clustering subdivides galaxies into individual building blocks undergoing vigorous, feedback-driven life cycles that vary with the galactic environment. These units structure the interstellar medium spatially, dynamically and chemically, and collectively define how galaxies form stars. At old ages, the relics of clustered star formation persist as ancient globular clusters, which hold a wealth of information allowing us to reconstruct the assembly histories of galaxies, culminating in the reconstruction of the Milky Way's merger tree. Towards smaller scales, stellar clustering has a measurable impact on the evolution of protoplanetary discs, the architectures of planetary systems, and the properties of planets themselves. I will discuss how this web of physical processes across a hierarchy of scales defines the cosmic ecosystem that we live in, and demonstrate that stellar clustering is at its focal point.

2020-12-04
15:00
Star Formation in the Turbulent-Multiphase Interstellar Medium
Shmuel Bialy (CfA)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
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Abstract

I will start with a broad review of the field of star formation and galaxy evolution, and some pressing open questions. I will then dive into the star-forming interstellar medium (ISM), asking the question, what regulates the star formation process on galactic scales? I will discuss the multiphase structure of the ISM, heating-cooling processes, and turbulence, all of which may play an important \;role in regulating star formation.  \;I will focus on a particularly appealing theory in which far-UV radiation from massive stars introduces a natural \;self-regulation process for star-formation, and will present recent results \; (Bialy 2020) for the intimate link between star-formation rate and the far-UV radiation intensity in the ISM. I will conclude by discussing promising future directions: (1) charting new ways for constraining poorly known interstellar properties: turbulence, 3D ISM structure, the nature of low energy cosmic-rays, and (2) an ongoing effort to construct an improved star-formation model for next-generation cosmological simulations (i.e., IllustrisTNG successors).

2020-12-04
15:00
Star Formation in the Turbulent-Multiphase Interstellar Medium
Shmuel Bialy (CfA)
Königstuhl Kolloquium
Via zoom link. Please contact organisers if you need the zoom information.,
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Abstract

I will start with a broad review of the field of star formation and galaxy evolution, and some pressing open questions. I will then dive into the star-forming interstellar medium (ISM), asking the question, what regulates the star formation process on galactic scales? I will discuss the multiphase structure of the ISM, heating-cooling processes