Heng Hao, Martin Elvis, Francesca Civano, Gianni Zamorani, Luis C. Ho, Andrea Comastri, Angela Bongiorno, Andrea Merloni, Marcella Brusa, Jonathan R. Trump, Mara Salvato, Chris D. Impey, Anton M. Koekemoer, Giorgio Lanzuisi, Annalisa Celotti, Knud Jahnke, Cristian Vignali, John D. Silverman, C. Megan Urry, Kevin Schawinski, Peter Capak
The near-infrared to optical-ultraviolet (0.1 -- 10 $\mu m$) spectral energy distribution (SED) shapes of 407 X-ray-selected radio-quiet type 1 AGN in the wide-field "Cosmic Evolution Survey" (COSMOS) have been studied for signs of evolution. For a sub-sample of 200 radio-quiet quasars with black hole mass estimation and host galaxy correction, we study the mean SEDs as a function of a broad range of redshift, bolometric luminosity, black hole mass and Eddington ratio, and compare them with the Elvis et al. (1994, E94) type 1 AGN mean SED. The mean SEDs in each bin are very similar to each other, showing no evidence of dependence on any of the analyzed parameters. We also checked the SED dispersion as a function of these four parameters, and found no significant dependance. The dispersion of the XMM-COSMOS SEDs is generally larger than E94 SED dispersion in the ultraviolet, which might be largely due to the broader "window function" for COSMOS quasars, and the X-ray based selection technique.
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http://arxiv.org/abs/1210.3033
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