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arXiv · astro-ph/0411416

Mid-infrared selection of quasar-2s in Spitzer's First Look Survey

M. Lacy·G. Canalizo·S. Rawlings·A. Sajina·L. Storrie-Lombardi·L. Armus·F. Marleau·A. Muzzin·.
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Abstract

We present early results from the spectroscopic follow-up of a sample of candidate obscured AGN selected in the mid-infrared from the Spitzer First Look Survey. Our selection allows a direct comparison of the numbers of obscured and unobscured AGN at a given luminosity for the first time, and shows that the ratio of obscured to unobscured AGN at infrared luminosities corresponding to low luminosity quasars is ~1:1 at z~0.5. Most of our optically-faint candidate obscured AGN have the high-ionization, narrow-line spectra expected from type-2 AGN. A composite spectrum shows evidence for Balmer absorption lines, indicating recent star-formation activity in the host galaxies. There is tentative evidence for a decrease in the obscured AGN fraction with increasing AGN luminosity.

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M. Lacy, G. Canalizo, S. Rawlings, A. Sajina, L. Storrie-Lombardi, L. Armus, F. Marleau, A. Muzzin, .. 2004-11-15. Mid-infrared selection of quasar-2s in Spitzer's First Look Survey. https://arxiv.org/abs/astro-ph/0411416

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