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The environments of z ~ 1 active galactic nuclei at 3.6μm

Falder, J. T. and Stevens, J. A. and Jarvis, Matt J. and Hardcastle, M. J. and Lacy, M. and McLure, R. J. and Hatziminaoglou, E. and Page, M. J. and Richards, G. T. (2010) The environments of z ~ 1 active galactic nuclei at 3.6μm. Monthly Notices of the Royal Astronomical Society, 405 (1). pp. 347-358. ISSN 0035-8711.

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We present an analysis of a large sample of active galactic nuclei (AGN) environments at z ~ 1 using stacked Spitzer data at 3.6 μm. The sample contains type 1 and type 2 AGN in the form of quasars and radio galaxies, and spans a large range in both optical and radio luminosity. We find, on average, that two to three massive galaxies containing a substantial evolved stellar population lie within a 200–300 kpc radius of the AGN, constituting a >8σ excess relative to the field. Secondly, we find evidence for the environmental source density to increase with the radio luminosity of AGN, but not with black hole mass. This is shown first by dividing the AGN into their classical AGN types, where we see more significant overdensities in the fields of the radio-loud AGN. If instead we dispense with the classical AGN definitions, we find that the source overdensity as a function of radio luminosity for all our AGN exhibits a positive correlation. One interpretation of this result is that the Mpc-scale environment is in some way influencing the radio emission that we observe from AGN. This could be explained by the confinement of radio jets in dense environments leading to enhance radio emission or, alternatively, may be linked to more rapid black hole spin brought on by galaxy mergers.

Item Type:Article
Related URLs:
URLURL TypeDescription DOIArticle
Jarvis, Matt J.0000-0001-7039-9078
Lacy, M.0000-0002-3032-1783
Page, M. J.0000-0002-6689-6271
Additional Information:© 2010 The Authors. Journal compilation © 2010 RAS. Accepted 2010 January 29. Received 2010 January 29; in original form 2009 December 3. This work is based (in part) on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. Support for this work was provided by NASA through an award issued by JPL/Caltech. JTF thanks the Science and Technology Facilities Council for a research studentship. MJH thanks the Royal Society for a research fellowship. RJM acknowledges funding from the Royal Society. 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.
Funding AgencyGrant Number
Science and Technology Facilities Council (STFC)UNSPECIFIED
Subject Keywords:galaxies: active; galaxies: clusters: general; galaxies: high-redshift; quasars: general; galaxies: statistics
Issue or Number:1
Record Number:CaltechAUTHORS:20100630-114204649
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Official Citation:The environments of z sim 1 active galactic nuclei at 3.6 mum (p 347-358) J. T. Falder, J. A. Stevens, Matt J. Jarvis, M. J. Hardcastle, M. Lacy, R. J. McLure, E. Hatziminaoglou, M. J. Page, G. T. Richards Published Online: Mar 10 2010 8:00AM DOI: 10.1111/j.1365-2966.2010.16444.x
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:18872
Deposited By: Ruth Sustaita
Deposited On:30 Jun 2010 21:39
Last Modified:09 Mar 2020 13:18

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