Toward and Understanding of Cluster Evolution: A Deep X-Ray Selected Cluster Catalog from ROSAT

摘要

Deep, high latitude ROSAT (Roentgen Satellite) PSPC (position sensitive proportional counter) images were analyzed to detect extended X-ray sources. More than one hundred such sources have been found. Extensive simulations have been performed to characterize the completeness of the source detection algorithms. The ROSAT observations show little evidence of evolution in either the clusters' luminosities or their size as characterized by their core radii. These observations are inconsistent with a high density CDM universe, but support either a low density universe, or one with a low value of Omega and a high value of Lamda. Recent optical spectroscopic results on the MMT telescope found two clusters in this sample with a redshift 0.5, and one with a redshift of 0.3.