Active galactic nucleus feedback and entropy injection in galaxy cluster cores

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 within r 500, from the Representative XMM-Newton Cluster Structure Survey to simulated base entropy profiles without feedback from both adaptive mesh refinement (AMR) and smoothed particle hydrodynamic (SPH) non-radiative simulations, we estimate the amount of additional non-gravitational energy, E ICM, contained in the intracluster medium (ICM), as well as the total energy feedback, E Feedback, from active galactic nuclei (AGNs; the central AGNs in most cases) into the clusters. The total feedback energy scales with the mean spectroscopic temperature as $E_{\rm Feedback} \propto T_{\rm sp}^{2.52 \pm 0.08}$ and $E_{\rm Feedback} \propto T_{\rm sp}^{2.17 \pm 0.11}$ for the SPH and AMR baseline profiles. The mean non-gravitational energy per particle within r 500 remaining in the ICM after energy lost during cooling is epsilonICM = 2.8 ± 0.8 keV for the SPH theoretical relation and epsilonICM = 1.7 ± 0.9 keV for the AMR theoretical relation. We use the NRAO/VLA Sky Survey source catalog to determine the radio luminosity, LR , at 1.4 GHz of the central source(s) of our sample. For T sp > 3 keV, the E Feedback correlates with LR , although with different normalization for cool-core and non-cool-core clusters. We show that AGNs could provide a significant portion of the feedback.