AEGIS: Radio and mid-infrared selection of obscured AGN candidates

  • S. Q. Park
  • , P. Barmby
  • , G. G. Fazio
  • , K. Nandra
  • , E. S. Laird
  • , A. Georgakakis
  • , D. Rosario
  • , S. P. Willner
  • , G. H. Rieke
  • , M. L.N. Ashby
  • , R. J. Ivison
  • , A. L. Coil
  • , S. Miyazaki

Research output: Contribution to journalArticlepeer-review

27 Scopus citations

Abstract

The application of multiwavelength selection techniques is crucial for discovering a complete and unbiased set of active galactic nuclei (AGNs). Here, we select a sample of 72 AGN candidates in the extended Groth strip (EGS) using deep radio and mid-infrared (mid-IR) data from the Very Large Array (VLA) and the Spitzer Space Telescope, and analyze their properties across other wavelengths. Only 30% of these sources are detected in deep 200 ks Chandra X-Ray Observatory pointings. The X-ray-detected sources demonstrate moderate obscuration with column densities of NH ≳ 1022 cm-2. A stacked image of sources undetected by Chandra shows low levels of X-ray activity, suggesting they may be faint or obscured AGNs. Less than 40% of our sample are selected as AGNs with optical broad lines, mid-IR power laws, or X-ray detections. Thus, if our candidates are indeed AGNs, then the radio/mid-IR selection criteria we use provide a powerful tool for identifying sources missed by other surveys.

Original languageEnglish (US)
Pages (from-to)744-750
Number of pages7
JournalAstrophysical Journal
Volume678
Issue number2
DOIs
StatePublished - May 10 2008

Keywords

  • Galaxies: active
  • Infrared: galaxies
  • Radio continuum: galaxies
  • X-rays: galaxies

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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