CONSTRAINTS ON THE CLUSTER MASS-TEMPERATURE RELATION IMPOSED BY THE DIFFUSE X-RAY BACKGROUND

摘要

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.