Abstract of the talk
given by Prof. Simone White, MPI für Astrophysik, Garching
THE FORMATION AND EVOLUTION OF GALAXY CLUSTERS
Monday, 7th July 2003
at 17:00 ct Uhr
in HNB at the Ruhr-Universität Bochum
Galaxy clusters are the most massive quasi-equilibrium structures in the present Universe. Recent microwave background data have established the initial conditions for cluster formation with considerable precision, but later evolution involves the complex and nonlinear interplay of a wide range of astrophysical processes. I will illustrate this using a variety of supercomputer simulations. The dark matter distribution within clusters is highly structured. The intergalactic gas in clusters is turbulent and far from thermodynamic equilibrium. The assembly of clusters and of many cluster galaxies is recent. Nevertheless, protogalactic star formation in cluster regions began early and could plausibly ionize enough material at high redshift to account for the high electron scattering optical depth measured by the WMAP satellite.