ZAH researchers are drivers and key participants in a large number of top international projects spanning observations, instrumentation, simulations and theory, in collaboration with the world's foremost research institutions. Such ZAH research collaborations are described below incl. links to more detailed websites presenting individual scopes and objectives.
The origin of the Milky Way and fundamental issues connected with galaxy evolution are the focus of the Collaborative Research Center 881 "The Milky Way System" at Heidelberg University. The SFB 881 is supported by the German Research Foundation (first funding period: 2011 - 2014, second funding period: 2015 - 2018). Its research work revolves around our own galaxy, the Milky Way. Scientists involved in the SFB investigate the origins and evolution of the Milky Way and its surroundings in order to clarify fundamental principles of galaxy formation. Other goals of the research work done by SFB 881 include to test the predictions of cosmological models on galaxy formation, to explore the assembly history of our Milky Way, to constrain the role of accretion, to investigate the small-scale distribution of dark matter, to study modes of star formation in different Galactic components from molecular clouds to star clusters and field stars, and to trace our Galaxy's star formation history, chemical evolution, and dynamical history across cosmic time.
Local Contact: Prof. Dr. Eva Grebel (ZAH/ARI)
The ZAH is directly involved in in the Gaia satellite mission of the European Space Agency ESA. Launched on December 19, 2013, Gaia measures the positions, parallaxes, proper motions, luminosities and colours of more than 1 billion stars with unprecedented precision, complemented by radial velcities and spectra of 100 million stars. Main goal is to elucidate the structure, formation and evolution of the Milky Way. ARI is leading the Gaia Data Reduction and Analysis Consortium, DPAC. DPAC is the Gaia Data Processing and Analysis Consortium, ESA's official science partner in the Gaia project. On September 14, 2016 the first Gaia catalogue was published i.a. with positions (α, δ) for all sources with acceptable formal standard errors on positions (in total 1,142,679,769 entries) and the five-parameter astrometric solution - positions, parallaxes, and proper motions - for 2,057,050 stars in common between the Tycho-2 Catalogue and Gaia.
Local contact: Dr. Michael Biermann (ZAH/ARI)
The appearance of the first stars of the universe marked a primary transition in cosmic history. Their light ended the “dark ages”. They played a key role in the metal enrichment and the reionization of the Universe, thereby shaping the galaxies we see today.
Understanding high-redshift star formation is central to many areas of modern astrophysics. However, still little is known about the origin and observable characteristics of the first stellar populations. The Advanced Grant Research Project "Formation of the First Stars", funded by the European Research Council (ERC), intends to shed light on the physical processes that govern the formation of stars in the early Universe. The projects applies a concerted, multi-facetted approach that combines a range of complementary expertise and innovative techniques.
In the two EU Training and Research Networks the strong (ANGLES - Astrophysics Network for Galaxy LEnsing Studies) and the weak gravitational lensing effect (DUEL - The Dark Universe with Extragalactic Lensing) is used to explore the visible and the dark Universe. In these two programs the international education of PhD students and Postdocs is a major goal. PLANET (Probing Lens Anomaly NETwork) is a collaboration to follow-up gravitational lensing events with the aim to discover extra-solar planets. This method is potentially sensitive to masses as small as the Earth's.
Lucifer and PRIMA at LBT
The Large Binocular Telescope "LBT" in Arizona (USA) is the most powerful telescope in the northern hemisphere. Lucifer I and II are cryogene spectrographs/cameras for both telescopes of the LBT, which can be used in the near Infrared up to 2.5 micrometer wavelength. The extremely high resolution of the LBT with these special instruments is perfectly suited for the investigation of star and planet formation as well as for detailed views on distant galaxies and quasars.
The Landessternware is a member of the PRIMA (Phase-Referenced Imaging and Micro-arcsecond Astrometry) Consortium, along with MPIA, Geneva Observatory, and ESO. This instrument is a VLTI backend. It measures the angular separation between a science star and a reference star. Changes in the angular separation, after calibration, indicate that the science star has a planetary system. PRIMA will be accurate to approximately 10 microarcseconds, sufficient for detecting Jupiter-sized planets. The Landessternwarte is responsible for the data-reduction software.
The High Energy Stereoscopic System H.E.S.S. (High Energy Stereoscopic System) in Namibia is the most powerful ground based system of Imaging Atmospheric Cherenkov Telescopes for the investigation of cosmic gamma rays in the 100 GeV energy range. The H.E.S.S. project is run by a collaboration of European and African institutions. The Landessternwarte Heidelberg (LSW) is a member of this collaboration.
Local contact: Prof. Dr. Stefan Wagner (ZAH/LSW)
AstroGrid-D and GRACE
AstroGrid-D is a research project in the area "e-Science" and "Grid middleware" for the support of scientific work in the context of the German D-Grid-Initiative. The resulting Grid-infrastructure will be available for all german scientists.
GRACE (GRApe + mpraCE)is a cooperation project, supported by the Volkswagen-Stiftung, dedicated to develop special hardware for high-performance computers. The hybrid-structure of this new type of super-computer combines three elements: a normal 64 prozessor Beowulf PC cluster, special developed computer hardware with fixed-wired gravitational force computation (GRAPE), developed in a project of Japanese astrophysicists at the Univ. of Tokyo, and flexible reprogrammable chips (FPGA, field programmable gate array). A performance of 4 Tflop/s computational speed is actually realized.
SDSS, RAVE and Pan-STARRS
The ZAH is partner of some big international projects, which scan systematically large areas of the sky. The SDSS-Project (Sloan Digital Sky Survey; 2000-2008) in New Mexico is the most extensive CCD survey for photometry and spectroscopy in order to determine the positions and physical properties of stars and galaxies at the Northern sky. The data are taken to investigate the history and structure of the Milky Way and galaxy evolution in general. The Radial Velocity Experiment (RAVE; 2003-2010) in Australia measures radial velocities and the chemical composition of 1 million stars at the Southern sky to determine the evolution of the Milky Way disc. The Panoramic Survey Telescope & Rapid Response System (Pan-STARRS) at Hawaii will start very soon a new Northern sky survey, which is able to measure five times fainter objects than the SDSS. Additionally to brightnesses and colours the variability of objects will be determined. The search for extrasolar planets and the investigation of structure and evolution of the Milky Way and distant galaxies are important ais of the project.
In the standard cosmological model, normal baryonic matter contributes only roughly 5% to the overall density of our universe, the rest being in the form of dark matter (27%) and dark energy (68%). The existence and dominance of dark energy was unexpected and raised fundamental questions such as the range of validity of Einstein's gravity, the role of extra dimensions, the existence of new forces, the nature of vacuum, the relation to the inflationary field and to the particle physics models.
The transregional research center 'The Dark Universe' (TRR33) investigates these topics by means of theoretical approaches, observations, and numerical simulations.
The 4MOST consortium has been selected by the European Southern Observatory (ESO) to provide the ESO community with a fibre-fed spectroscopic survey facility on the VISTA telescope with a large enough field-of-view to survey a large fraction of the southern sky in a few years. The facility will be able to simultaneously obtain spectra of ~2400 objects distributed over an hexagonal field-of-view of 4 square degrees. This high multiplex of 4MOST, combined with its high spectral resolution, will enable detection of chemical and kinematic substructure in the stellar halo, bulge and thin and thick discs of the Milky Way, thus help unravel the origin of our home galaxy. The consortium consists of 15 members, some contributing to the hardware development, others to the software development, and almost all to the science case development (not detailed here). The 4MOST-team at the Landessternwarte is resposible for the development and assembly of the high resolution spectrograph.