1. The COSMOS AGN Spectroscopic Survey I: XMM Counterparts
- Author
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Trump, Jonathan R., Impey, Chris D., Elvis, Martin, McCarthy, Patrick J., Huchra, John P., Brusa, Marcella, Salvato, Mara, Capak, Peter, Cappelluti, Nico, Civano, Francesca, Comastri, Andrea, Gabor, Jared, Hao, Heng, Hasinger, Gunther, Jahnke, Knud, Kelly, Brandon C., Lilly, Simon J., Schinnerer, Eva, Scoville, Nick Z., and Smolcic, Vernesa
- Subjects
Astrophysics - Abstract
We present optical spectroscopy for an X-ray and optical flux-limited sample of 677 XMM-Newton selected targets covering the 2 deg^2 COSMOS field, with a yield of 485 high-confidence redshifts. The majority of the spectra were obtained over three seasons (2005-2007) with the IMACS instrument on the Magellan (Baade) telescope. We also include in the sample previously published Sloan Digital Sky Survey spectra and supplemental observations with MMT/Hectospec. We detail the observations and classification analyses. The survey is 90% complete to flux limits of f_{0.5-10 keV}>8 x 10^-16 erg cm^-2 s^-1 and i_AB+<22, where over 90% of targets have high-confidence redshifts. Making simple corrections for incompleteness due to redshift and spectral type allows for a description of the complete population to $i_AB+<23. The corrected sample includes 57% broad emission line (Type 1, unobscured) AGN at 0.13
3 x 10^42 erg s^-1) to z<1, of both optically obscured and unobscured types. We find statistically significant evidence that the obscured to unobscured AGN ratio at z<1 increases with redshift and decreases with luminosity., Comment: Accepted for publication in the ApJ. 31 pages, 17 figures. Table 2 is available on request - Published
- 2008
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