Feedback in Cluster Cores and Beyond

Subha Majumdar

December 04, 2013

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Abstract: We make the first estimate of non-gravitational energy profiles in galaxy cluster cores (and beyond) based on observational data. Comparing the observed entropy profiles from the Representative XMM-Newton Cluster Structure Survey to simulated base entropy profiles without feedback from both AMR and SPH non-radiative simulations, we estimate the amount of additional non-gravitational energy contained in the intra-cluster medium (ICM), as well as the total energy feedback, from active galactic nuclei (AGNs; the central AGNs in most cases) into the clusters. We find that the energy feedback scales with the cluster temperature from groups to cluster scales with relatively small scatter. The estimated mean non-gravitational energy per particle remaining in the ICM after energy lost during cooling is more than corresponding numbers used/found in radiative simulations of clusters, in general. By cross-correlating with the NVSS source catalog to determine the radio luminosity, L_R, at 1.4 GHz of the central source(s) of our sample, we find that the feedback correlates with L_R, although with different normalization for cool-core and non-cool-core clusters. We argue that AGNs could provide a significant portion of the feedback. Simulations of clusters including AGN feedback must reproduce these feedback profiles in addition to reproducing cluster scaling relations.