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 Cl0024+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 N-body/hydrodynamics simulation of such a collision between two galaxy clusters. 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 this simulated data to generate profiles of the surface brightness and temperature profiles. The surface brightness profiles are better fit by a superposition of two β-model profiles rather than a single profile, in agreement with the observations of Cl 0024+17. However, due to projection effects, much of the density and temperature structure of the clusters post-collision is not seen in the observations. In particular, the observed temperatures from spectral fitting are lower than the temperature of the highest-temperature gas in the clusters. We determine from our fitted profiles that if the system is modeled as a single cluster, then 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:
-
AAS/High Energy Astrophysics Division #10
- Pub Date:
- March 2008
- Bibcode:
- 2008HEAD...10.0909Z