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Title: The X-ray Zurich environmental study (X-zens). I. Chandra and XMM-Newton observations of active galactic nuclei in galaxies in nearby groups

Abstract

We describe X-ray observations with Chandra and XMM-Newton of 18 M {sub group} ∼ 1-6 × 10{sup 13} M {sub ☉}, z ∼ 0.05 galaxy groups from the Zurich ENvironmental Study. The X-ray data aim at establishing the frequency and properties, unaffected by host galaxy dilution and obscuration, of active galactic nuclei (AGNs) in central and satellite galaxies, also as a function of halo-centric distance. X-ray point-source detections are reported for 22 of the 177 galaxies, down to a sensitivity level of f {sub 0.5} {sub –} {sub 8} {sub keV} ∼ 5 × 10{sup –15} erg cm{sup –2} s{sup –1}, corresponding to a limiting luminosity of L {sub 0.5} {sub –} {sub 8} {sub keV} ∼ 3 × 10{sup 40} erg s{sup –1}. With the majority of the X-ray sources attributed to AGNs of low-to-moderate levels (L/L {sub Edd} ≳ 10{sup –4}), we discuss the detection rate in the context of the occupation of AGNs to halos of this mass scale and redshift and compare the structural and morphological properties between AGN-active and non-active galaxies. At galaxy mass scales <10{sup 11} M {sub ☉}, central galaxies appear to be a factor of ∼4 more likely to host AGNs thanmore » satellite galaxies of similar mass. This effect, coupled with the tendency for AGNs to be hosted by massive galaxies, explains the (weak) trend for AGNs to be preferentially found in the inner parts of group halos, with no detectable trend with halo-centric distance in the frequency of AGNs within the satellite population. Finally, our data indicate that the rate of decline with redshift of AGN activity in galaxy groups matches that of the global AGN population, indicating that either AGN activity occurs preferentially in group halos or that the evolution rate is independent of halo mass.« less

Authors:
 [1]; ; ; ; ;  [2]
  1. Kavli Institute for the Physics and Mathematics of the Universe, Todai Institutes for Advanced Study, the University of Tokyo (Kavli IPMU, WPI), Kashiwa 277-8583 (Japan)
  2. Institute for Astronomy, ETH Zürich, CH-8093, Zürich (Switzerland)
Publication Date:
OSTI Identifier:
22348321
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 780; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COMPARATIVE EVALUATIONS; DETECTION; DILUTION; GALAXY NUCLEI; LUMINOSITY; MASS; OCCUPATIONS; POINT SOURCES; QUASARS; RED SHIFT; SATELLITES; SENSITIVITY; X RADIATION; X-RAY GALAXIES; X-RAY SOURCES

Citation Formats

Silverman, J. D., Miniati, F., Carollo, C. M., Cibinel, A., Lilly, S. J., Schawinski, K., and Finoguenov, A., E-mail: john.silverman@ipmu.jp. The X-ray Zurich environmental study (X-zens). I. Chandra and XMM-Newton observations of active galactic nuclei in galaxies in nearby groups. United States: N. p., 2014. Web. doi:10.1088/0004-637X/780/1/67.
Silverman, J. D., Miniati, F., Carollo, C. M., Cibinel, A., Lilly, S. J., Schawinski, K., & Finoguenov, A., E-mail: john.silverman@ipmu.jp. The X-ray Zurich environmental study (X-zens). I. Chandra and XMM-Newton observations of active galactic nuclei in galaxies in nearby groups. United States. https://doi.org/10.1088/0004-637X/780/1/67
Silverman, J. D., Miniati, F., Carollo, C. M., Cibinel, A., Lilly, S. J., Schawinski, K., and Finoguenov, A., E-mail: john.silverman@ipmu.jp. 2014. "The X-ray Zurich environmental study (X-zens). I. Chandra and XMM-Newton observations of active galactic nuclei in galaxies in nearby groups". United States. https://doi.org/10.1088/0004-637X/780/1/67.
@article{osti_22348321,
title = {The X-ray Zurich environmental study (X-zens). I. Chandra and XMM-Newton observations of active galactic nuclei in galaxies in nearby groups},
author = {Silverman, J. D. and Miniati, F. and Carollo, C. M. and Cibinel, A. and Lilly, S. J. and Schawinski, K. and Finoguenov, A., E-mail: john.silverman@ipmu.jp},
abstractNote = {We describe X-ray observations with Chandra and XMM-Newton of 18 M {sub group} ∼ 1-6 × 10{sup 13} M {sub ☉}, z ∼ 0.05 galaxy groups from the Zurich ENvironmental Study. The X-ray data aim at establishing the frequency and properties, unaffected by host galaxy dilution and obscuration, of active galactic nuclei (AGNs) in central and satellite galaxies, also as a function of halo-centric distance. X-ray point-source detections are reported for 22 of the 177 galaxies, down to a sensitivity level of f {sub 0.5} {sub –} {sub 8} {sub keV} ∼ 5 × 10{sup –15} erg cm{sup –2} s{sup –1}, corresponding to a limiting luminosity of L {sub 0.5} {sub –} {sub 8} {sub keV} ∼ 3 × 10{sup 40} erg s{sup –1}. With the majority of the X-ray sources attributed to AGNs of low-to-moderate levels (L/L {sub Edd} ≳ 10{sup –4}), we discuss the detection rate in the context of the occupation of AGNs to halos of this mass scale and redshift and compare the structural and morphological properties between AGN-active and non-active galaxies. At galaxy mass scales <10{sup 11} M {sub ☉}, central galaxies appear to be a factor of ∼4 more likely to host AGNs than satellite galaxies of similar mass. This effect, coupled with the tendency for AGNs to be hosted by massive galaxies, explains the (weak) trend for AGNs to be preferentially found in the inner parts of group halos, with no detectable trend with halo-centric distance in the frequency of AGNs within the satellite population. Finally, our data indicate that the rate of decline with redshift of AGN activity in galaxy groups matches that of the global AGN population, indicating that either AGN activity occurs preferentially in group halos or that the evolution rate is independent of halo mass.},
doi = {10.1088/0004-637X/780/1/67},
url = {https://www.osti.gov/biblio/22348321}, journal = {Astrophysical Journal},
issn = {0004-637X},
number = 1,
volume = 780,
place = {United States},
year = {Wed Jan 01 00:00:00 EST 2014},
month = {Wed Jan 01 00:00:00 EST 2014}
}