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arXiv · 1007.3494

AEGIS: Demographics of X-ray and Optically Selected AGNs

Renbin Yan·Luis C. Ho·Jeffrey A. Newman·Alison L. Coil·Christopher N. A. Willmer·Elise S. Laird·Antonis Georgakakis·James Aird·Pauline Barmby·Kevin Bundy·Michael C. Cooper·Marc Davis·S. M. Faber·Taotao Fang·Roger L. Griffith·Anton M. Koekemoer·David C. Koo·Kirpal Nandra·Shinae Q. Park·Vicki L. Sarajedini·Benjamin J. Weiner·S. P. Willner
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Abstract

We develop a new diagnostic method to classify galaxies into AGN hosts, star-forming galaxies, and absorption-dominated galaxies by combining the [O III]/Hbeta ratio with rest-frame U-B color. This can be used to robustly select AGNs in galaxy samples at intermediate redshifts (z<1). We compare the result of this optical AGN selection with X-ray selection using a sample of 3150 galaxies with 0.3 10^44 erg/s in our sample are not detected in our 200 ks Chandra images, most likely due to moderate or heavy absorption by gas near the AGN. The 2--7 keV detection rate of Seyfert 2s at z~0.6 suggests that their column density distribution and Compton-thick fraction are similar to that of local Seyferts. Multiple sample selection techniques are needed to obtain as complete a sample as possible.

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Renbin Yan, Luis C. Ho, Jeffrey A. Newman, Alison L. Coil, Christopher N. A. Willmer, Elise S. Laird, Antonis Georgakakis, James Aird, Pauline Barmby, Kevin Bundy, Michael C. Cooper, Marc Davis, S. M. Faber, Taotao Fang, Roger L. Griffith, Anton M. Koekemoer, David C. Koo, Kirpal Nandra, Shinae Q. Park, Vicki L. Sarajedini, Benjamin J. Weiner, S. P. Willner. 2011-01-20. AEGIS: Demographics of X-ray and Optically Selected AGNs. https://doi.org/10.1088/0004-637x%2F728%2F1%2F38

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