Radio AGN in 13,240 galaxy clusters from the Sloan Digital Sky Survey

TL;DR

This study analyzes the radio properties of Brightest Cluster Galaxies in over 13,000 galaxy clusters, revealing correlations between radio emission, galaxy mass, and cluster richness, and characterizing the sizes and distribution of radio AGN.

Contribution

It provides a large-scale statistical analysis of radio AGN in galaxy clusters, including size distributions and environmental dependencies, using SDSS and FIRST survey data.

Findings

19.7% of BCGs are associated with radio sources

Radio emission peaks at 55 kpc, extending to 200 kpc

Radio-loud BCGs correlate with galaxy mass and cluster richness

Abstract

We correlate the positions of 13,240 Brightest Cluster Galaxies (BCGs) with 0.1 <= z <= 0.3 from the maxBCG catalog with radio sources from the FIRST survey to study the sizes and distributions of radio AGN in galaxy clusters. We find that 19.7% of our BCGs are associated with FIRST sources, and this fraction depends on the stellar mass of the BCG, and to a lesser extent on the richness of the parent cluster (in the sense of increasing radio loudness with increasing mass). The intrinsic size of the radio emission associated with the BCGs peaks at 55 kpc, with a tail extending to 200 kpc. The radio power of the extended sources places them on the divide between FR I and FR II type sources, while sources compact in the radio tend to be somewhat less radio-luminous. We also detect an excess of radio sources associated with the cluster, instead of with the BCG itself, extending out to ~1.4 Mpc.