CaltechAUTHORS
Published November 10, 2011 | Version Published
Journal Article Open

The Population of High-Redshift Active Galactic Nuclei in the CHANDRA-Cosmos Survey

Creators

  • 1. ROR icon Harvard-Smithsonian Center for Astrophysics
  • 2. ROR icon Max Planck Institute for Extraterrestrial Physics
  • 3. ROR icon Max Planck Institute for Plasma Physics
  • 4. ROR icon California Institute of Technology
  • 5. ROR icon Astronomical Observatory of Rome
  • 6. ROR icon Ehime University
  • 7. ROR icon University of Hawaii at Manoa
  • 8. ROR icon University of California, Riverside
  • 9. ROR icon National Autonomous University of Mexico
  • 10. ROR icon Agenzia Spaziale Italiana
  • 11. ROR icon Max Planck Institute for Astrophysics
  • 12. ROR icon Kavli Institute for the Physics and Mathematics of the Universe
  • 13. ROR icon University of Bologna
  • 14. ROR icon University of Crete
  • 15. ROR icon Space Telescope Science Institute

Abstract

We present the high-redshift (3 3. Eighty-one sources are selected in the 0.5-2 keV band, fourteen are selected in the 2-10 keV and six in the 0.5-10 keV bands. We sample the high-luminosity (log L_((2-10keV)) > 44.15 erg s^(–1)) space density up to z ~ 5 and a fainter luminosity range (43.5 erg s^(–1) < log L_((2-10keV)) < 44.15 erg s^(–1)) than previous studies, up to z = 3.5. We weighted the contribution to the number counts and the space density of the sources with photometric redshift by using their probability of being at z > 3. We find that the space density of high-luminosity AGNs declines exponentially at all the redshifts, confirming the trend observed for optically selected quasars. At lower luminosity, the measured space density is not conclusive, and a larger sample of faint sources is needed. Comparisons with optical luminosity functions and black hole formation models are presented together with prospects for future surveys.

Additional Information

© 2011 The American Astronomical Society. Received 2010 December 23; accepted 2011 August 8; published 2011 October 21. The authors thank the referee for suggestions which improved this paper's content. The authors thank J. Aird and E. Glikman for sharing their luminosity functions, and G. Risaliti, R. D'Abrusco, and A. Goulding for useful discussions. This work was supported in part by NASA Chandra grant No. GO7-8136A (M.E., F.C., H.H.), the Blancheflor Boncompagni Ludovisi foundation (F.C.) and the Smithsonian Scholarly Studies (F.C.). F.S. acknowledges the Alexander von Humboldt Foundation for support. In Italy this work is supported by ASI/INAF contracts I/009/10/0 and I/088/06. Facilities: CXO (ACIS), HST (ACS), XMM

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Additional details

Identifiers

Eprint ID
28918
Resolver ID
CaltechAUTHORS:20120123-115613901

Funding

NASA
GO7-8136A
Blancheflor Boncompagni Ludovisi foundation
Smithsonian Institution
Alexander von Humboldt Foundation
Agenzia Spaziale Italiana (ASI)
I/009/10/0
Agenzia Spaziale Italiana (ASI)
I/088/06/0
Istituto Nazionale di Astrofisica (INAF)

Dates

Created
2012-01-24
Created from EPrint's datestamp field
Updated
2021-11-09
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Caltech Custom Metadata

Caltech groups
COSMOS , Infrared Processing and Analysis Center (IPAC)