Cluster X-ray Luminosity Evolution

Abstract

Whether the X-ray luminosities of clusters of galaxies evolve has been a contentious issue for over ten years. However, the data available to address this issue have improved dramatically as cluster surveys from the ROSAT archive near completion. There are now three samples of nearby clusters and seven distant cluster samples. We present a uniform analysis of four of the distant cluster samples. Each exhibits highly statistically significant luminosity evolution. We combine three of these samples to measure the high redshift cluster X-ray luminosity function with good statistics that shows the nature of the evolution.