Energy deposition profiles and entropy in galaxy clusters

Abstract

We report the results of our study of fractional entropy enhancement in the intracluster medium (ICM) of the clusters from the representative XMM-Newton cluster structure survey. We compare the observed entropy profile of these clusters with that expected for the ICM without any feedback, as well as with the introduction of preheating and cooling. We make the first estimate of the total, as well as radial, non-gravitational energy deposition up to r 500 for this large, nearly flux-limited, sample of clusters. We find that the total energy deposition corresponding to the entropy enhancement is proportional to the cluster temperature (and hence cluster mass). The energy deposition per particle scaled by T sp, ΔE/T sp has a similar profile in all clusters, and is more pronounced in the central regions. Our results support models of entropy enhancement through active galactic nucleus feedback. © 2012. The American Astronomical Society. All rights reserved.