1. The clustering amplitude of X-ray-selected AGN atz∼ 0.8: evidence for a negative dependence on accretion luminosity
- Author
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G. Mountrichas, Antonis Georgakakis, Mara Salvato, Andrea Merloni, M. L. Menzel, Kirpal Nandra, Zheng-Wei Liu, and N. Fanidakis
- Subjects
QSOS ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Astrophysics::High Energy Astrophysical Phenomena ,Population ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,01 natural sciences ,Luminosity ,0103 physical sciences ,education ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,Physics ,education.field_of_study ,Mass distribution ,010308 nuclear & particles physics ,Astronomy ,Astronomy and Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Redshift ,Galaxy ,Dark matter halo ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Halo ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
The northern tile of the wide-area and shallow XMM-XXL X-ray survey field is used to estimate the average dark matter halo mass of relatively luminous X-ray selected AGN [$\rm log\, L_X (\rm 2-10\,keV)= 43.6^{+0.4}_{-0.4}\,erg/s$] in the redshift interval $z=0.5-1.2$. Spectroscopic follow-up observations of X-ray sources in the XMM-XXL field by the Sloan telescope are combined with the VIPERS spectroscopic galaxy survey to determine the cross-correlation signal between X-ray selected AGN (total of 318) and galaxies (about 20,\,000). We model the large scales (2-25\,Mpc) of the correlation function to infer a mean dark matter halo mass of $\log M / (M_{\odot} \, h^{-1}) = 12.50 ^{+0.22} _{-0.30}$ for the X-ray selected AGN sample. This measurement is about 0.5\,dex lower compared to estimates in the literature of the mean dark matter halo masses of moderate luminosity X-ray AGN [$L_X (\rm 2-10\,keV)\approx 10^{42} - 10^{43}\,erg/s$] at similar redshifts. Our analysis also links the mean clustering properties of moderate luminosity AGN with those of powerful UV/optically selected QSOs, which are typically found in halos with masses few times $10^{12}\,M_{\odot}$. There is therefore evidence for a negative luminosity dependence of the AGN clustering. This is consistent with suggestions that AGN have a broad dark matter halo mass distribution with a high mass tail that becomes sub-dominant at high accretion luminosities. We further show that our results are in qualitative agreement with semi-analytic models of galaxy and AGN evolution, which attribute the wide range of dark matter halo masses among the AGN population to different triggering mechanisms and/or black hole fueling modes., MNRAS accepted. 10 pages, 7 figures, 2 tables
- Published
- 2016
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