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arXiv · 1005.4968

AGN clustering in the local Universe: an unbiased picture from Swift-BAT

N. Cappelluti·M. Ajello·D. Burlon·M. Krumpe·T. Miyaji·S. Bonoli·J. Greiner
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Abstract

We present the clustering measurement of hard X-ray selected AGN in the local Universe. We used a sample of 199 sources spectroscopically confirmed detected by Swift-BAT in its 15-55 keV all-sky survey. We measured the real space projected auto-correlation function and detected a signal significant on projected scales lower than 200 Mpc/h. We measured a correlation length of r0=5.56+0.49-0.43 Mpc/h and a slope γ=1.64-0.08 -0.07. We also measured the auto-correlation function of Type I and Type II AGN and found higher correlation length for Type I AGN. We have a marginal evidence of luminosity dependent clustering of AGN, as we detected a larger correlation length of luminous AGN than that of low luminosity sources. The corresponding typical host DM halo masses of Swift-BAT are log(MDMH) 12-14 h^-1 M/M_sun, depending on the subsample. For the whole sample we measured log(MDMH)\sim 13.15 h-1 M/M_sun which is the typical mass of a galaxy group. We estimated that the local AGN population has a typical lifetime tau_AGN \sim 0.7 Gyr, it is powered by SMBH with mass MBH \sim 1-10x10^8 M_\odot and accreting with very low efficiency, log(epsilon)-2.0. We also conclude that local AGN host galaxies are typically red-massive galaxies with stellar mass of the order 2-80x10^10 h^-1 M_sun. We compared our results with clustering predictions of merger-driven AGN triggering models and found a good agreement.

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N. Cappelluti, M. Ajello, D. Burlon, M. Krumpe, T. Miyaji, S. Bonoli, J. Greiner. 2010-05-27. AGN clustering in the local Universe: an unbiased picture from Swift-BAT. https://doi.org/10.1088/2041-8205%2F716%2F2%2Fl209

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