X-Ray bright active galactic nuclei in massive galaxy clusters - II. The fraction of galaxies hosting active nuclei

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  • S. Ehlert
  • A. von der Linden
  • S. W. Allen
  • W. N. Brandt
  • Y. Q. Xue
  • B. Luo
  • A. Mantz
  • R. G. Morris
  • D. Applegate
  • P. Kelly

We present a measurement of the fraction of cluster galaxies hosting X-ray bright active galactic nuclei (AGN) as a function of clustercentric distance scaled in units of r500. Our analysis employs high-quality Chandra X-ray and Subaru optical imaging for 42 massive X-ray-selected galaxy cluster fields spanning the redshift range 0.2 < z < 0.7. In total, our study involves 176 AGN with bright (R < 23) optical counterparts above a 0.5-8.0 keV flux limit of 10-14 erg cm-2 s-1. When excluding central dominant galaxies from the calculation, we measure a cluster galaxy AGN fraction in the central regions of the clusters that is~3 times lower than the field value. This fraction increases with clustercentric distance before becoming consistent with the field at ~2.5r500. Our data exhibit similar radial trends to those observed for star formation and optically selected AGN in cluster member galaxies, both of which are also suppressed near cluster centres to a comparable extent. These results strongly support the idea that X-ray AGN activity and strong star formation are linked through their common dependence on available reservoirs of cold gas.

Original languageEnglish
Article numberstt2025
JournalMonthly Notices of the Royal Astronomical Society
Volume437
Issue number2
Pages (from-to)1942-1949
Number of pages8
ISSN0035-8711
DOIs
Publication statusPublished - 1 Nov 2013

    Research areas

  • Galaxies: Active, Galaxies: Clusters: General, Galaxies: Photometry, X-rays: Galaxies, Xrays: Galaxies: Clusters

ID: 122297356