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Universität zu Köln
Mathematisch-Naturwissenschaftliche Fakultät

I. Physikalisches Institut

Project A1 / Sonderforschungsbereich 494

Large-scale distribution and structure of the interstellar medium

Carsten Kramer (Project Leader)
Markus Cubick, Holger Jakob, Michael Masur, Martin Miller, Bhaswati Mookerjea, Volker Ossenkopf, Markus Röllig, Robert Simon, Amiel Sternberg (Tel Aviv University), Kefeng Sun, Jürgen Stutzki


This project section aims at a better understanding of the structure, dynamics, energy balance, and chemistry of the interstellar medium (ISM) in the Milky Way and in nearby, external galaxies. To this end, we are developing physical models of photon dominated regions (PDRs) as well as tools to characterize the structure of the clouds. Based on its experience with KOSMA and other submillimeter observatories, A1 is deeply involved in the preparation for observations with the new observatories NANTEN2, SOFIA, and HIFI/Herschel, all of which will become available in the period 2006-8.

Two areas of modelling/analysis are particularly important:

Modelling of Photon dominated regions (PDRs)

The Cologne PDR group has a record of more than 20 publications over the past 10 years. In the previous application period (2003-5), we have used state-of-the-art PDR models to interpret the integrated intensities of all major gas cooling lines and the FIR dust continuum in Galactic star forming regions and in external galaxies, thereby studying the energy balance of molecular clouds. This work puts us in the best position to interpret velocity resolved FIR lines which we are going to observe with the new FIR observatories SOFIA and HIFI/Herschel in a couple of guaranteed and open time projects. NANTEN2 will allow for extended maps of the two fine structure transitions of atomic carbon and mid-J CO lines at the same angular resolution allowing to save precious satellite observing time. We will continue large-scale mapping projects of the CO 2-1 and 3-2 lines with KOSMA, enhanced by a new array receiver.

Analysis of the small and large-scale structure of interstellar clouds

While the KOSMA-3m and the NANTEN2-4m telescopes are best suited to conduct large-scale mapping observations, they will also reach spatial resolutions of down to 0.07 pc (14 000 AU) in the nearby low-mass star forming regions. These are scales at which the turbulent support of clouds is expected to break down. Both telescopes are therefore perfectly suited to study the large-scale structure of molecular clouds down to scales where coherent cores may form. In A1, we are studying the physical processes governing this structure by statistical analysis of the observed data and the comparison with numerical models of the turbulent medium. To map still lower spatial scales and to obtain maps of the dust continuum, we will use the large submm telescopes APEX/CSO/JCMT and SMA/ALMA.

Research topics:

Large-scale mapping projects Detailed studies of Galactic Photon Dominated Regions
Nearby large spiral galaxies Additional projects of A1
Modeling of Photon Dominated Regions Structure of Molecular Clouds

Documents and Presentations


Infos für Studenten

Observatories (deadlines)