Correlations of the feedback energy and BCG radio luminosity in galaxy clusters

TL;DR

This study investigates the relationship between feedback energy from active galactic nuclei and radio luminosity of BCGs in galaxy clusters, revealing correlations with cluster properties and greater AGN effectiveness in less massive clusters.

Contribution

It provides new empirical evidence linking AGN feedback energy and BCG radio luminosity to cluster thermal properties, highlighting the mass dependence of feedback efficiency.

Findings

Feedback energy correlates with cluster temperature as E_feedback ∝ T_obs^{0.98±0.37}.

BCG radio luminosity scales with gas mass as L_R ∝ m_{g,obs}^{1.76±0.71}.

Radio luminosity correlates with X-ray luminosity as L_R ∝ L_{X,obs}^{0.94±0.35}.

Abstract

We study the excess entropy and the corresponding non-gravitational feedback energy ($E_{feedback}$) in the intra-cluster medium (ICM) by considering a sample of 38 galaxy clusters using Chandra X-ray and NRAO VLA Sky Survey (NVSS)/Giant Metrewave Radio Telescope (GMRT) radio observations. We find moderate correlation of the feedback energy and brightest cluster galaxy (BCG) radio luminosity ($L_R$) with the various cluster thermal properties. We show conclusively that the active galactic nucleus (AGN) is more effective in transferring feedback energy to the ICM in less massive clusters. We find that within $0.3r_{500}$, the feedback energy correlates with cluster temperature as $E_{feedback}\propto T_{obs}^{0.98\pm0.37}$. Moreover, for radio detected BCG sample we find that BCG radio luminosity at 1.4 GHz scales with gas mass as $L_R\propto m_{g,obs}^{ 1.76\pm0.71}$ and with X-ray luminosity as $L_R\propto L_{X,obs}^{0.94\pm0.35}$. Finally, we discuss the implications of our results with regard to feedback in clusters.