Clusters of Galaxies at Intermediate Redshift: The EMSS Sample Revisited

We have completed a detailed study of clusters of galaxies within the EMSS cluster sample. We analyzed ROSAT X-ray images of the CNOC subsample of the EMSS clusters, and calculated mass profiles which we compared with lensing and dynamical estimates. We carried out an optical observational program to investigate new X-ray sources detected in a re-analysis of the Einstein IPC images. This program detected several previously undiscovered, distant, and rich clusters of galaxies, apparently missing from the original EMSS sample. We calculate the completeness of the EMSS cluster sample, and present some of the new clusters as a possible new class of X-ray low surface brightness, or low X-ray luminosity clusters (relative to their optical richness). We have also re-analyzed the entire EMSS distant (z>=0.14) cluster sample, using available X-ray temperature measurements, as well as all available ROSAT data to measure surface brightness profiles in order to make a more accurate correction to the detected flux, and therefore more accurate calculation of the X-ray cluster luminosities. In conjunction with our discovery of new clusters, this completes our calculations of the EMSS cluster X-ray luminosity functions (XLFs), and we present revised values of the evolution in the cluster XLF.