Constraints on the Cluster Mass‐Temperature Relation Imposed by the Diffuse X‐Ray Background

Abstract

We show the constraints on the dynamical properties of groups and clusters of galaxies imposed by the diffuse X-ray background (XRB) emission. We first estimate the total integrated diffuse X-ray emission associated with groups and clusters of galaxies using the X-ray luminosity function derived from the Press-Schechter mass function and the mass-temperature (M-T) and X-ray luminosity-temperature relations of the galaxy groups and clusters. We have applied different cosmological models and M-T relations in estimating the integrated emission. For most of the models associated with the M-T relations derived from X-ray mass estimates, we find that the integrated emission significantly exceeds the unresolved diffuse XRB emission. We suggest that using the X-ray surface brightness profiles as a cluster mass estimator may significantly underestimate the real mass of galaxy clusters. Our methods provide strong constraints on the distribution and the dynamical evolution models of the galaxy clusters.