The 1<z<5 Infrared Luminosity Function of Type I Quasars
Abstract
We determine the rest-frame 8 micron luminosity function of type I quasars over the redshift range 1<z<5. Our sample consists of 292 24 micron sources brighter than 1 mJy selected from 7.17 square degrees of the Spitzer Space Telescope MIPS survey of the NOAO Deep Wide-Field Survey Bootes field. The AGN and Galaxy Evolution Survey (AGES) has measured redshifts for 270 of the R<21.7 sources and we estimate that the contamination of the remaining 22 sources by stars and galaxies is low. We are able to select quasars missed by ultra-violet excess quasar surveys, including reddened type I quasars and 2.2<z<3.0 quasars with optical colors similar to main sequence stars. We find reddened type I quasars comprise 20% of the type I quasar population. Nonetheless, the shape, normalization, and evolution of the rest-frame 8 micron luminosity function is comparable to that of quasars selected from optical surveys. The 8 micron luminosity function of type I quasars is well approximated by a power-law with index -2.75(+/-0.14). We directly measure the peak of the quasar space density to be at z=2.6(+/-0.3).
Keywords
Cite
@article{arxiv.astro-ph/0510504,
title = {The 1<z<5 Infrared Luminosity Function of Type I Quasars},
author = {Michael J. I. Brown and Kate Brand and Arjun Dey and Buell T. Jannuzi and Richard Cool and Emeric Le Floc'h and Christopher S. Kochanek and Lee Armus and Chao Bian and Jim Higdon and Sarah Higdon and Casey Papovich and George Rieke and Marcia Rieke and J. D. Smith and B. T. Soifer and Dan Weedman},
journal= {arXiv preprint arXiv:astro-ph/0510504},
year = {2008}
}
Comments
Accepted for publication in the ApJ, 19 pages, 12 figures