Year: 2001
Type: article
Abstract: The deepest region of the ROSAT All-Sky Survey, at the north ecliptic pole, has been studied to produce a complete and unbiased X-ray-selected sample of clusters of galaxies. This sample is used to investigate the nature of cluster evolution and to explore the potential implications for large-scale structure models. The survey is 99.6% optically identified. Spectroscopic redshifts have been measured for all the extragalactic identifications. In this Letter, first results on cluster evolution are presented based on a comparison between the number of the observed clusters in the north ecliptic pole survey and the number of expected clusters assuming no-evolution models. At z > 0.3, there is a deficit of clusters with respect to the local universe that is significant at greater than 4.7 σ. The evolution appears to commence at L 0.5-2.0 keV > 1.8 × 10 44 ergs s -1 in our data. The negative evolution goes in the same direction as the original Extended Medium-Sensitivity Survey result, the results from the 160 deg 2 survey, and the recent results from the ROSAT Deep Cluster Survey. At lower redshifts, there is no evidence for evolution, a result in agreement with these and other cluster surveys.
Source: The Astrophysical Journal
DOI: 10.1086/320671
Authors: I. M. Gioia, J. P. Henry, C. R. Mullis, W. Voges, U. G. Briel, H. Böhringer, J. P. Huchra
Institutions: University of Hawaiʻi at Mānoa, California Institute of Technology, Centre National de la Recherche Scientifique, University of Hawaii System, W.M. Keck Observatory, Istituto di Radioastronomia di Bologna, Canada–France–Hawaii Telescope, National Research Council Canada, Max Planck Institute for Extraterrestrial Physics, Center for Astrophysics Harvard & Smithsonian
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2952124758