Skip to main content
U.S. flag

An official website of the United States government

Return to search results
💡 Advanced Search Tip

Search by organization or tag to find related datasets

ROSAT PSPC Catalog of Clusters of Galaxies

Published by High Energy Astrophysics Science Archive Research Center | National Aeronautics and Space Administration | Metadata Last Checked: September 14, 2025 | Last Modified: 2025-09-10
This is a catalog of 203 clusters of galaxies serendipitously detected in 647 ROSAT PSPC high Galactic latitude pointings covering 158 square degrees. This is one of the largest X-ray-selected cluster samples, comparable in size only to the ROSAT All-Sky Survey sample of nearby clusters (Ebeling et al. 1997). Clusters in the inner 17.'5 of the ROSAT PSPC field of view are detected using the spatial extent of their X-ray emission. Fluxes of detected clusters range from 1.6 x 10<sup>-14</sup> to 8 x 10<sup>-12</sup> ergs s<sup>-1</sup> cm<sup>-2</sup> in the 0.5-2 keV energy band. X-ray luminosities range from 10<sup>42</sup> ergs s<sup>-1</sup>, corresponding to very poor groups, to ~5 x 10<sup>44</sup> ergs s<sup>-1</sup>, corresponding to rich clusters. The cluster redshifts range from z = 0.015 to z > 0.5. The catalog lists X-ray fluxes, core radii, and spectroscopic redshifts for 73 clusters and photometric redshifts for the remainder. Of 223 X-ray sources, 203 have been optically confirmed as clusters of galaxies. Of the remaining 20 sources, 19 are likely false detections arising from blends of unresolved point X-ray sources. Optical identifications of the remaining object are hampered by a nearby bright star. Above a flux of 2 x 10<sup>-13</sup> ergs s<sup>-1</sup> cm<sup>-2</sup>, 98% of extended X-ray sources are optically confirmed clusters. The number of false detections and their flux distribution are in perfect agreement with simulations. The log N-log S relation for clusters derived from this catalog shows excellent agreement with counts of bright clusters derived from the Einstein Extended Medium Sensitivity Survey and the ROSAT All-Sky Survey. At fainter fluxes, its log N-log S relation agrees with the smaller area WARPS survey. The cluster counts appear to be systematically higher than those from a 50 square degree survey by Rosati et al. This database was created by the HEASARC in December 2001 based on the CDS/ADC catalog J/ApJ/502/558/ (table3.dat). This is a service provided by NASA HEASARC .

Find Related Datasets

Click any tag below to search for similar datasets

Complete Metadata

data.gov

An official website of the GSA's Technology Transformation Services

Looking for U.S. government information and services?
Visit USA.gov