Formation and evolution of X-ray clusters - A hydrodynamic simulation of the intracluster medium

Abstract

The thermodynamic history of the hot intracluster medium in a cluster of Coma richness was examined using a numerical simulation incorporating three-dimensional hydrodynamics of a collisional baryonic component within a self-consistently evolving dark matter mass distribution. The model evolves to states at low redshifts whose X-ray and 'optical' properties are strikingly similar to Coma and A2256. The elliptical X-ray isophotes seen at z = 0 are remnants of a merger event which occurred at z = 0.2; thus, Coma and A2256 probably suffered moderate merger events in the recent past. The model also indicates that clusters of Coma richness should display a Suniaev-Zel'dovich central decrement of about 0.5 mK.