The Massive and Distant Clusters of WISE Survey. VIII. Radio Activity in Massive Galaxy Clusters

Abstract

Abstract We present a study of the central radio activity of galaxy clusters at high redshift. Using a large sample of galaxy clusters at 0.7 < z < 1.5 from the Massive and Distant Clusters of Wide-field Infrared Survey Explorer Survey and the Faint Images of the Radio Sky at Twenty-Centimeters 1.4 GHz catalog, we measure the fraction of clusters containing a radio source within the central 500 kpc, which we term the cluster radio-active fraction, and the fraction of cluster galaxies within the central 500 kpc exhibiting radio emission. We find tentative (2.25σ) evidence that the cluster radio-active fraction increases with cluster richness, while the fraction of cluster galaxies that are radioluminous ( W Hz−1) does not correlate with richness at a statistically significant level. Compared to that calculated at 0 < z < 0.6, the cluster radio-active fraction at 0 < z < 1.5 increases by a factor of 10. This fraction is also dependent on the radio luminosity. Clusters at higher redshift are much more likely to host a radio source of luminosity W Hz−1 than are lower-redshift clusters. We compare the fraction of radioluminous cluster galaxies to the fraction measured in a field environment. For 0.7 < z < 1.5, we find that both the cluster and field radioluminous galaxy fraction increases with stellar mass, regardless of environment, though at fixed stellar mass, cluster galaxies are roughly 2 times more likely to be radioluminous than field galaxies.