@article{55458cafcecb48ceb30b8c4180fe25a3,
title = "X-ray bright active galactic nuclei in massive galaxy clusters - III. New insights into the triggering mechanisms of cluster AGN",
abstract = "We present the results of a new analysis of the X-ray selected active galactic nuclei (AGN) population residing in and behind 135 of the most massive galaxy clusters in the redshift range of 0.2 < z < 0.9 observed with Chandra. With a sample of more than 11 000 Xray point sources, we are able to measure, for the first time, evidence for evolution in the cluster AGN population beyond the expected evolution of field AGN. Our analysis shows that overall number density of cluster AGN scales with the cluster mass as ~M-1.2 500. There is no evidence for the overall number density of cluster member X-ray AGN depending on the cluster redshift in a manner different than field AGN, nor is there any evidence that the spatial distribution of clusterAGN(given in units of the cluster overdensity radius r500) strongly depends on the cluster mass or redshift. TheM-1.2 ± 0.7 scaling relationwemeasure is consistent with theoretical predictions of the galaxy merger rate in clusters, which is expected to scalewith the cluster velocity dispersion, α, as ~α-3 or ~M-1. This consistency suggests that galaxy mergers may be an important contributor to the cluster AGN population, a result that is further corroborated by visual inspection of Hubble images for 23 spectroscopically confirmed cluster member AGN in our sample. A merger-driven scenario for the triggering of X-ray AGN is not strongly favoured by studies of field galaxies, however, suggesting that different mechanisms may be primarily responsible for the triggering of cluster and field X-ray AGN.",
author = "S. Ehlert and Allen, {S. W.} and Brandt, {W. N.} and Canning, {R. E.A.} and B. Luo and A. Mantz and Morris, {R. G.} and {Von Der Linden}, A. and Xue, {Y. Q.}",
note = "Funding Information: We thank Patrick Broos and Leisa Townsley for technical support, insight, and advice as to how to utilize best the ACIS-EXTRACT software package for this study. We also thank Bret Lehmer for providing the cumulative number counts data for the CDF-S, and Nina Bonaven-tura at the Chandra X-ray Center{\textquoteright}s Helpdesk for technical support in the catalogue production. We also wish to thank the anonymous referee whose comments have greatly improved this paper. Support for this work was provided by the Department of Energy Grant Number DE-AC02-76SF00515 and Chandra X-ray Center grant GO0-11149X. Support for SE was provided by the Smithsonian Astrophysical Observatory (SAO) subcontract SV2-82023 under NASA contract NAS8-03060. We also acknowledge support from NASA ADP grant NNX10AC99G, Chandra X-ray Center grants SP1-12007A, and National Science Foundation grants AST-0838187 and AST-1140019. We also acknowledge support from the Thousand Young Talents (QingNianQianRen) program (KJ2030220004), the USTC startup funding (ZC9850290195), and the National Natural Science Foundation of China through NSFC-11243008 and NSFC-11473026. Additional funding as provided by the Strategic Priority Research Program {\textquoteleft}The Emergence of Cosmological Structures{\textquoteright} of the Chinese Academy of Sciences (XDB09000000). This research has made use of the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. Based on observations made with the NASA/ESA Hubble Space Telescope, and obtained from the Hubble Legacy Archive, which is a collaboration between the Space Telescope Science Institute (STScI/NASA), the Space Telescope European Coordinating Facility (ST-ECF/ESA), and the Canadian Astronomy Data Centre (CADC/NRC/CSA). Funding Information: We thank Patrick Broos and Leisa Townsley for technical support, insight, and advice as to howto utilize best the ACIS-EXTRACT software package for this study. We also thank Bret Lehmer for providing the cumulative number counts data for the CDF-S, and Nina Bonaventura at the Chandra X-rayCenter's Helpdesk for technical support in the catalogue production. We also wish to thank the anonymous referee whose comments have greatly improved this paper. Support for this work was provided by the Department of Energy Grant Number DE-AC02-76SF00515 and Chandra X-ray Center grant GO0-11149X. Support for SE was provided by the Smithsonian Astrophysical Observatory (SAO) subcontract SV2-82023 under NASA contract NAS8-03060. We also acknowledge support from NASA ADP grant NNX10AC99G, Chandra X-ray Center grants SP1-12007A, and National Science Foundation grantsAST-0838187 and AST-1140019. We also acknowledge support from the Thousand Young Talents (QingNianQianRen) program (KJ2030220004), the USTC startup funding (ZC9850290195), and the National Natural Science Foundation of China through NSFC-11243008 and NSFC- 11473026. Additional funding as provided by the Strategic Priority Research Program 'The Emergence of Cosmological Structures' of the Chinese Academy of Sciences (XDB09000000). This research has made use of the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. Based on observations made with the NASA/ESA Hubble Space Telescope, and obtained from the Hubble Legacy Archive, which is a collaboration between the Space Telescope Science Institute (STScI/NASA), the Space Telescope European Coordinating Facility (ST-ECF/ESA), and the Canadian Astronomy Data Centre (CADC/NRC/CSA). Publisher Copyright: {\textcopyright} 2014 The Authors.",
year = "2015",
doi = "10.1093/mnras/stu2091",
language = "English (US)",
volume = "446",
pages = "2709--2729",
journal = "Monthly Notices of the Royal Astronomical Society",
issn = "0035-8711",
publisher = "Oxford University Press",
number = "3",
}