Cool Cores in Clusters of Galaxies

Hans Boehringer, Max-Planck-Institut fuer extraterr. Physik

The centers of about half of all galaxy clusters show a very rich and complex phenomenology of X-ray emitting plasma at thermally unstable conditions, with energy input from central AGN, and metal rich plasma. In the talk I will review some of the collected evidence for a plasma state where cooling is balanced by heat input and where chemical enrichment helps to diagnose transport processes in this complex plasma. I will also outline the importance of understanding these effects for the use of galaxy clusters in cosmological research.