Publication Date:
2013-01-03
Description:
We present an analysis of the X-ray bright point-source population in 43 massive clusters of galaxies observed with the Chandra X-ray Observatory . We have constructed a catalogue of 4210 rigorously selected X-ray point sources in these fields, which span a survey area of 4.2 ° 2 . This catalogue reveals a clear excess of sources when compared to deep blank-field surveys, which amounts to roughly 1 ± 0.4 additional sources per cluster, likely active galactic nuclei (AGN) associated with the clusters. The excess sources are located within the overdensity radius r 500 , with the largest excess observed near the cluster centres. The average radial profile of the excess X-ray sources of the cluster is well described by a power law [ N ( r ) ~ r β ] with an index of β ~ –0.6. An initial analysis using literature results on the mean profile of member galaxies in massive X-ray-selected clusters indicates that the fraction of galaxies hosting X-ray AGN rises with increasing clustercentric radius, being approximately three times higher near r 500 than in the central regions. This trend is qualitatively similar to that observed for star formation in cluster member galaxies.
Print ISSN:
0035-8711
Electronic ISSN:
1365-2966
Topics:
Physics
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