ICM properties and AGN distribution in high-z RCS clusters

TL;DR

This study examines the X-ray properties and AGN distribution in high-redshift optically selected galaxy clusters from the RCS, revealing lower L-T normalization compared to X-ray selected clusters and an excess of low-luminosity AGN near cluster centers.

Contribution

First spectral analysis of ICM in optically selected high-z RCS clusters, comparing their properties to X-ray selected clusters and analyzing AGN distribution.

Findings

ICM emission detected in most clusters

RCS clusters have lower L-T normalization than X-ray selected clusters

Excess of low-luminosity AGN near cluster centers

Abstract

Here we discuss the X-ray properties of clusters of galaxies optically selected in the Red-Sequence Cluster Survey (RCS) observed with the Chandra satellite, at redshifts 0.6 < z < 1.2. We intended to assess the evolutionary stage of optically selected high-z clusters of galaxies, performing a spectral analysis of the diffuse emission from their ICM. We also investigated the distribution of AGN in their surroundings. The background subtracted spectra were analyzed and fitted with a single temperature model to measure average ICM temperature, X-ray bolometric luminosity and Fe abundance within typical radii between 200 and 350 kpc. We also analyzed the point source number density and spatial distribution in the RCS clusters fields as a function of the X-ray flux. We detected emission for the majority of the clusters, except for three, for which we have only marginal detection at ~3 Sigma. We find that the normalization of the L-T relation for RCS clusters is a factor of ~2 lower than the one for X-ray selected clusters. We confirm that the Fe abundance in the detected objects is consistent with that of X-ray selected clusters at the same redshift. We also found an excess of low-luminosity AGN towards the center of the clusters.