A Galaxy Cluster Collision Viewed Along the Line of Sight: Simulated X-ray Observations
Abstract
Several lines of evidence have suggested that the the galaxy cluster Cl 0024+17, an apparently relaxed system, is actually a collision of two clusters, the interaction occurring along our line of sight. In this paper we present a high-resolution N-body/hydrodynamics simulation of such a collision. We have created mock X-ray observations of our simulated system using MARX, a program that simulates the on-orbit performance of the Chandra X-ray Observatory. We analyze these simulated data to generate profiles of the surface brightness and temperature. The simulated surface brightness profiles are better fit by a superposition of two β-model profiles than a single profile, in agreement with the observations of Cl 0024+17. However, due to projection effects, much of the post-collision density and temperature structure of the clusters is not seen in the observations. In particular, the observed temperatures from spectral fitting are much lower than the temperature of the hottest gas. We determine from our fitted profiles that if the system is modeled as a single cluster, the hydrostatic mass estimate is a factor 2-3 less than the actual mass, but if the system is modeled as two galaxy clusters in superposition, a hydrostatic mass estimation can be made which is accurate to within 10-20%.
- Publication:
-
American Astronomical Society Meeting Abstracts #212
- Pub Date:
- May 2008
- Bibcode:
- 2008AAS...212.2107Z