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

Lacy, Mark and Canalizo, Gabriela and Rawlings, Steve and Sajina, Anna and Storrie-Lombardi, Lisa and Armus, Lee and Marleau, Francine R. and Muzzin, Adam (2005) Mid-infrared selection of Quasar-2s in Spitzer's First Look Survey. Memorie della Società Astronomica Italiana, 76 . pp. 154-157. ISSN 0037-8720.

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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.

Item Type:Article
Related URLs:
URLURL TypeDescription
Lacy, Mark0000-0002-3032-1783
Canalizo, Gabriela0000-0003-4693-6157
Sajina, Anna0000-0002-1917-1200
Storrie-Lombardi, Lisa0000-0002-5987-5210
Armus, Lee0000-0003-3498-2973
Muzzin, Adam0000-0002-9330-9108
Additional Information:© 2005 SAIt. Società Astronomica Italiana. This work is based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory (JPL), California Institute of Technology under NASA contract 1407. Support for this work was provided by NASA through JPL.
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
Subject Keywords:galaxies:active, infrared radiation, galaxies:distances and redshifts
Record Number:CaltechAUTHORS:20170323-072953109
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Official Citation:Mid-infrared selection of Quasar-2s in Spitzer's First Look Survey Lacy, M., Canalizo, G., Rawlings, S., Sajina, A., Storrie-Lombardi, L., Armus, L., , Memorie della Società Astronomica Italiana, v.76, p.154-157 (2005)
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:75343
Deposited By: Ruth Sustaita
Deposited On:23 Mar 2017 14:44
Last Modified:07 Nov 2019 14:58

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