The Outskirts of Galaxy Clusters: To r200 and Beyond with Suzaku, XMM-Newton and Chandra
Abstract
Galaxy clusters are the largest gravitationally bound structures in the universe and thus provide the best opportunity to study cosmology at work. Their outskirts, regions close to the virial radius, have not been well studied and could aid in our understanding of cluster growth, structure and mass. We show results from a program to constrain the properties of the outer intra-cluster medium in a sample of galaxy clusters, making use the strengths of the three complementary X-ray observatories: Suzaku which has a low and stable background, XMM-Newton which has a very high sensitivity, and Chandra which provides good spatial resolution. The sample comprises eleven mostly relaxed clusters at 0.1-0.2 with full azimuthal coverage to beyond r200. Here we report results obtained from a few of the clusters starting with Abell 773. We are able to measure diffuse X-ray emission well beyond r200. Our results suggest that the ICM is not in hydrostatic equilibrium in the outskirts of this cluster: we detect clear azimuthal variations in temperature and surface brightness. We also present the density, entropy and baryonic function profiles for each of these clusters.
- Publication:
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AAS/High Energy Astrophysics Division #13
- Pub Date:
- April 2013
- Bibcode:
- 2013HEAD...1311604G