11 April 2002 CfA Colloquium


Title: Hydrodynamics of Cluster Formation

Speaker: Michael Norman

Abstract:

Most of the baryons in galaxy clusters reside in their intracluster media (ICM). What is their dynamical, thermal, and chemical state? While much has been learned from X-ray observations of local (z~0) clusters, our understanding of the formation history of clusters and their ICMs is still sketchy. I review results of high resolution cosmological hydrodynamical simulations which shed some light on these questions. The calculations make use of a new numerical technique--Eulerian adaptive mesh refinement--which is well suited to the problem. A complete sample of simulated clusters in a LCDM cosmology has been computed and archived on the web at http://sca.ncsa.uiuc.edu. We find a universal temperature profile for ICMs exterior to the cooling cores which is well fit by T~(1+r/a)^x, where a~R_vir/1.5 and x~-1.6. This profile is insensitive to cosmology, and in good agreement with the results of Markevitch et al. (1998). I will also present results of new simulations including radiative cooling, galaxy formation, and feedback which suggest an alternative explanation to the origin of so-called cooling flow clusters, and also shed some light on how cluster ICMs become enriched with metals.

References for students:

http://www.cita.utoronto.ca/~cloken/PAPERS/profs_preprint.ps