Astrophysical research in Heidelberg


The International Max Planck Research School for Astronomy and Cosmic Physics at the University of Heidelberg (IMPRS-HD) is a collaborative effort between the Max Planck Society and the University of Heidelberg.
Founded 1385 the University of Heidelberg is the oldest university of present-day Germany. 15 % of Heidelberg's 27,000 students come from outside Germany, over 2,400 of them from Europe and 890 from Asia (in total from 128 countries).
Regularly ranked as one of the best German universities, Heidelberg University successfully brings together old tradition and modern conceptions.
A poll published 2010 by the German Academic Exchange Service (DAAD) concluded that Heidelberg is Germany's most popular university for international doctoral students.


The Heidelberg area has one of the highest densities of astrophysical research in Germany hosting five world-class institutes. More then 30 professors and a total scientific staff (astrophysics) of about 200 people. Additional staff could be acquired by external funding (national and international grants).
The Faculty of Physics and Astronomy at the University of Heidelberg is the largest in Germany concerning the number of Ph.D. graduations per year.


The following institutes take part in IMPRS-HD:

  • Max Planck Institute for Astronomy (MPIA)
  • Max Planck Institute for Nuclear Physics (MPIK), Astrophysics and Particle Physics divisions
  • Institute for Theoretical Astrophysics (ITA)
  • Astronomisches Rechen-Institut (ARI), ( ''Institute for Astronomical Computing'' )
  • Landessternwarte Königstuhl (LSW), ( ''Königstuhl State Observatory'' )
  • Heidelberg Institute of Theoretical Studies (HITS)

  • Since 2005 the three university institutes ARI, ITA, LSW form the Zentrum für Astronomie der Universität Heidelberg (ZAH) (''Center for Astronomy of Heidelberg University'').
    Since autumn 2007 IMPRS-HD is an independent part of the Heidelberg Graduate School of Fundamental Physics, HGSFP.

    Almost any topic of astrophysics is covered by researchers in Heidelberg ...
    Phenomenologically, this ranges from elementary particles (astroparticle physics) over the interstellar gas, cosmic rays and microscopic dust particles to sub-stellar bodies as planets, moons, comets, brown dwarfs to stars of different age, size or constituents, to extragalactic objects (galaxies, dark matter) and finally the universe as a whole (cosmology).
    Observationally, almost all frequencies are covered. While the emphasis is on optical/infrared frequencies and on very high energy energies of TeV gamma rays, also mm and radio observations aer carried out. Researchers in Heidelberg apply and develop ground-based telescope and instrumentation techniques as well as satellite instrumentation.
    In theory various fields are covered with focal points in gravitational lensing, (magneto)-hydrodynamic or SPH simulations, transport, acceleration and non-thermal emission theory for relativistic particles, and radiation transfer modeling.



    The Max Planck Institute for Astronomy (MPIA) has three main research foci; of which one is the formation, evolution, and dynamical evolution of Galaxies, including observational cosmology, another the formation of stars and planets, and the third one the development of state-of-the-art instrumentation techniques for large ground-based telescopes and space missions. MPIA has operated for many years the Calar Alto Observatory in south-east Spain.
    The primary research goals in the department of planet and star formation, are a better understanding of the various processes involved in star and planet formation over the broadest possible range of masses and different environmental and initial conditions. The scientific approach to these problems will be focused on high-resolution techniques provided by adaptive optics-assisted observations and interferometry as well as sensitive infrared observations from the ground and space.
    Examples of the instrument development at the MPIA for space-based Infrared Observatories are the PACS camera for HERSCHEL and the MIR camera MIRI for the Next Generation Space Telescope (JWST). For ground-based observations, a number of instruments and telescopes have been developed at the MPIA, in particular for the Calar Alto Observatory, ESO VLT, or the LBT.
    The main research goal in the department of galaxies and cosmology, is to empirically derive a picture of the evolution of the structural properties of galaxies, and to understand where, when and how the stars in galaxies were built up over cosmic time. These, in turn, are important tests of models of galaxy formation and evolution, guiding their development and refinement. A common thread connecting all topics considered is the requirement that one links the properties of distant galaxy populations in the early Universe with present-day galaxies, using similar data analysis and techniques.
    The MPIA theory groups aim to answer the fundamental questions in the field of planet & star formation and galaxy formation and cosmology by exploiting advanced analytical methods as well as the power of supercomputers.
    The Max Planck Institute for Nuclear Physics takes part in IMPRS-HD with several groups dealing with astrophysics and particle astrophysics.
    The theoretical astrophysics group considers the physics of non-thermal, high-energy particles in the Universe, in particular their acceleration mechanism, their radiation, and their dynamical interaction with interstellar/intergalactic matter.
    The activity of the high energy estrophysics group is concerned with theoretical studies of high energy cosmic gamma-ray sources, the theory of gamma-ray experiments, and data analysis and interpretation for the experiments with the HEGRA and H.E.S.S. Cherenkov telescopes. These projects are done jointly with the division of Particle Physics at the institute in the framework of large international collaborations.
    Infrared Astrophysics is a joint activity of several groups within the MPIK, interested in interstellar dust properties, galactic star formation, supernova remnants, and comets. For ESA's IR Space Observatory (ISO) the MPIK provided calibrated hardware, calibration tools and facilities for the pre flight.
    Neutrino astrophysics, as research activity concerning Solar Neutrinos, started in the mid 80ties in a joint effort with the Brookhaven National Laboratory to observe solar neutrinos with a Gallium detector. The subsequent international project GALLEX was performed under the MPIK leadership in the underground Laboratory in del Gran Sasso in Italy. Its successful completion led to an upgrade named Gallium Neutrino Observatory (GNO) and to an active participation in the BOREXINO experiment.
    One of the astrophysical goals of the Non Accelerator Particle Physics group is the experimental search for Dark Matter
    The Institute for Theoretical Astrophysics (ITA) at the University of Heidelberg carries out research in cosmology, extragalactic astrophysics, galactic dynamics, star formation, stellar evolution and astrochemistry.
    Understanding the formation of stars in galaxies like our Milky Way or in the early universe is the goal of the star formation group at ITA. Stars form by gravoturbulent fragmentation of magnetized interstellar gas clouds. The supersonic turbulence ubiquitously observed in Galactic molecular gas generates strong density fluctuations with gravity taking over in the densest and most massive regions. Collapse sets in to build up stars and star clusters. This process is studied by means of numerical simulations and theoretical model calculations. Planets and planetary systems can build up in the accretion disks around new-born stars. Studying the physics of accretion disks, the process of dust formation in these disks, or the formation of structures in the B-ring of Saturn are important research topics at ITA. Other major fields of research are the numerical modeling and interpretation of cosmic radiation fields and the atmospheres of cool giant stars.
    The distribution of galaxies on the sky, their X-ray signature and magnetic fields are considered in the group network of galaxy clusters. The light deflection by gravity is another major research topic at ITA. gravitational lensing leading to (de-)magnification and distortion of the observable images can be caused by stellar mass objects to galaxy clusters. Maps of the dark-matter distribution in galaxy clusters can be constructed from the weaker distortion of very many galaxies in their background (see left). On even larger scale researches at ITA consider cosmological questions as the nature of dark matter and dark energy, structure formation in the universe, or the anisotropy of the CMB as observed by WMAP.
    The Astronomisches Rechen-Institut (ARI) covers a wide range of research areas including cosmology, gravitational lensing, galaxy evolution, stellar dynamics, and astrometry. Moreover, it plays a leading role in the preparation of the Gaia satellite mission of the European Space Agency and in special-purpose high-performance computing.
    One of the primary research foci at the ARI is galaxy evolution. Our goal is to understand how galaxies formed and evolved over a Hubble time and to refine the corresponding cosmological models. Stellar populations are valuable witnesses of the formation history of a galaxy, providing a fossil record also of its chemical evolution and accretion history. Stellar dynamics yield information on the underlying mass distribution, gravitational potential, and dark matter content as well as on past interactions. Studying the properties of galaxies in groups and clusters constrains their assembly histories, the origin of different galaxy types, and the cosmological substructure problem.
    The ARI participates in several large international survey projects including the Sloan Digital Sky Survey (SDSS), the Radial Velocity Experiment (RAVE), Pan-STARRS, and ESA's cornerstone satellite mission Gaia. Gaia will uncover the detailed evolutionary history of our own Milky Way.
    These observational efforts are complemented by extensive dynamical and chemo-dynamical simulations on special-purpose supercomputers.
    The other main research focus at the ARI is gravitational lensing, studying various applications of light deflection as caused by planets, stars, galaxies, and clusters of galaxies. Microlensing of distant quasars and of stars in the Milky Way or nearby galaxies may help to detect (or exclude) compact dark matter candidates. Examining and modeling giant arc systems produced by the lensing effect of galaxy clusters on background galaxies helps to measure the mass and the mass distribution of the lensing cluster. By monitoring the lightcurves of microlensed stars in the Galactic bulge and by searching for short time-scale deviations, planets around other stars are being detected.
    Moreover, the ARI is involved in efforts to detect gravitational waves directly, e.g. via ESA's Laser Interferometer Space Antenna (LISA).
    Research topics at the Landessternwarte Heidelberg-Königstuhl (LSW) (i.e. Heidelberg-Königstuhl State Observatory) consider observational and theoretical issues in stellar and extragalactic astrophsyics as well as a strong participation in instrumentation projects.
    The research in stellar astrophysics concentrates on Hot Stars, the Theory of Young Stellar Objects, and Extrasolar Planets. The hot star group at the LSW mainly studies the mass-loss and variability of hot, massive stars, in the last years mainly with the fiber-linked echelle spectrographs FEROS and HEROS at ESO, La Silla.
    In a collaboration with ESO and colleagues from Ondrejov, we investigate the spectroscopic variability of Be stars and the formation of their disks. In addition, chemical abundances of B stars are studied with LTE and NLTE model-atmosphere analysis. A comprehensive search for extrasolar planets around massive, evolved stars is carried out at the LSW using the Hamilton spectrograph at Lick Observatory. As part of an international consortium, the LSW also participates in the preparation of the astrometric planet search with PRIMA at the VLTI.
    The Galactic Archaeology Group at LSW is concerned with the search for the most metal-poor and hence oldest stars of the Galaxy, and the determination of their chemical abundance patterns by means of optical high-resolution spectroscopy. These stars are important tools for studying the earliest phases of formation and chemical evolution of the Galaxy.
    Another main area of research are Supermassive Black Holes and Active galactic nuclei, in particular Quasar variability, which is also studied within the EC-TMR research grant ENIGMA, or Multi-frequency Studies of Blazar Variability , Emission Lines of AGN, Hot Spots in Radio Galaxies, Active Galaxies at High Redshift and also Theoretical Studies of AGN.
    Research at the LSW further considers the Structure of Spiral Galaxies and the Morphological Evolution of Galaxies in Clusters. The LSW is a partner in the HESS collaboration and responsible for multi-frequency studies with this leading facility of high-energy astrophysics.
    One of the LSW research topics in extragalactic astrophysics is the FORS Deep Field (FDF) project, relying on guaranteed time granted along with the development of the FORS (FOcal Reducer/low dispersion Spectrograph) instrument for the VLT.
    Besides FORS, the LSW is involved in other instrumentation projects as the LBT (Large Binocular Telescope), ATOM (Automatic Telescope for Optical Monitoring), LUCIFER, the LBT NIR spectroscopic utility incl. camera and integral-field unit, and SOLSPEC.
    The Heidelberg Institute for Theoretical Studies (HITS) takes part in IMPRS-HD with the group working on Theoretical Astrophysics.
    The Theoretical Astrophysics Group at HITS has been established 2010 and is led by Prof. Volker Springel of Heidelberg University the group. Numerical simulations of cosmic structure formation, as carried out in the “Theoretical Astrophysics” (TAP) group , are one of the best tools for understanding our quite strange Universe, in which most of the material consists of unknown "Dark Matter", and a mysterious "Dark Energy" field drives an accelerated expansion of space. The work focuses on the formation and evolution of galaxies, supermassive black holes, stars, and planets. A major goal of the group's research is to unlock the power of modern high-performance supercomputers for basic research in theoretical astrophysics. To this end, both the state-of-the art computational facilities at HITS and supercomputers in Germany and across Europe are employed.