2016/08/31 by J. Singal, J. George, A. Gerber
Physics and Astronomy · #astro-ph.CO #astro-ph.GA
paper · pdf · doi:10.3847/0004-637x/831/1/60
published as ApJ, 2016, 831, 60 · 13 pages, 11 figures, published in ApJ. arXiv admin note: text overlap with arXiv:1207.3396
arxiv created 2016/10/27 · arxiv updated 2016/11/09
We determine the 22μm luminosity evolution and luminosity function for quasars from a data set of over 20,000 objects obtained by combining flux-limited Sloan Digital Sky Survey optical and Wide field Infrared Survey Explorer mid-infrared data. We apply methods developed in previous works to access the intrinsic population distributions non-parametrically, taking into account the truncations and correlations inherent in the data. We find that the population of quasars exhibits positive luminosity evolution with redshift in the mid-infrared, but with considerably less mid-infrared evolution than in the optical or radio bands. With the luminosity evolutions accounted for, we determine the density evolution and local mid-infrared luminosity function. The latter displays a sharp flattening at local luminosities below ∼ 1031 erg sec-1 Hz-1, which has been reported previously at 15 μm for AGN classified as both type-1 and type-2. We calculate the integrated total emission from quasars at 22 μm and find it to be a small fraction of both the cosmic infrared background light and the integrated emission from all sources at this wavelength.