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Theoretical Astrophysics group Cologne - TAC

Our research deals with the numerical modelling of the star formation process by means of high-performance, 3D, magneto-hydrodynamical (MHD) simulations. The simulations cover large spatial scales from ISM physics on kpc scales over molecular clouds on scales of 10 - 100 pc to star forming filaments on (sub-) pc scales and finally to protostellar discs and jets on scales of 10 - 1000 AU.

In our research group we use several tools like the (M)HD codes FLASH, GADGET, GANDALF, the astrochemical code KROME, 3D-PDR or radiative transport codes like RADMC-3D and POLARIS.

Prof. Dr. Stefanie Walch-Gassner is the head of the SILCC project (SImulating the life Cyle of molecular Clouds), a collaboration of several European astrophysical institutes, which has set the aim to model the formation, evolution, and dispersal of molecular clouds in 3D, MHD simulations with particular focus on a detailed astro-chemical modelling and the inclusion of various feedback processes.

Contact information:

  • Phone: (+49|0) 221 / 470 - 3497
  • Fax: (+49|0) 221 / 470 - 5162
  • Email: walch [at] ph1.uni-koeln.de

Consultation hours

upon agreement in Room 1.14, Building 312 

The evolution of velocity dispersion in OB associations - The case of Scorpius-Centaurus

vergrößern:
Figure 1. Left: 3D surfaces of 34 stellar populations in the Sco-Cen stellar complex (age-coloured, from about 2–20 Myr, blue to red) as selected with SigMA. A spatial-temporal pattern is visible, with older clusters at the center and young clusters at the outskirts of the complex. In particular, three chains of star formation propagation are visible, partially extending below the Galactic Plane (toward CrA and LCC). See also the link to the INTERACTIVE version. Right: Cumulative 3D velocity dispersion, starting from the oldest cluster (e-Lup); at each age-step the stars of the next-younger cluster are added and the velocity dispersion is calculated for all the stars that are in clusters with ages larger than given on the x-axis. The symbols are again color-coded for age (see also left panel), and are scaled by cluster size (of the cluster that was added at that age-step). A monotonic increase in velocity dispersion with age is visible, cumulating in about 4 km/s when all stellar members from the 34 Sco-Cen clusters are combined.