A survey of luminous high-redshift quasars with SDSS and WISE II. the bright end of the quasar luminosity function at z ~ 5

Bibliographic Details
Title: A survey of luminous high-redshift quasars with SDSS and WISE II. the bright end of the quasar luminosity function at z ~ 5
Authors: Yang, Jinyi, Wang, Feige, Wu, Xue-Bing, Fan, Xiaohui, McGreer, Ian D., Bian, Fuyan, Yi, Weimin, Yang, Qian, Ai, Yanli, Dong, Xiaoyi, Zuo, Wenwen, Green, Richard, Jiang, Linhua, Wang, Shu, Wang, Ran, Yue, Minghao
Publication Year: 2016
Collection: Astrophysics
Subject Terms: Astrophysics - Astrophysics of Galaxies
More Details: This is the second paper in a series on a new luminous z ~ 5 quasar survey using optical and near-infrared colors. Here we present a new determination of the bright end of the quasar luminosity function (QLF) at z ~ 5. Combined our 45 new quasars with previously known quasars that satisfy our selections, we construct the largest uniform luminous z ~ 5 quasar sample to date, with 99 quasars in the range 4.7 <= z < 5.4 and -29 < M1450 <= -26.8, within the Sloan Digital Sky Survey (SDSS) footprint. We use a modified 1/Va method including flux limit correction to derive a binned QLF, and we model the parametric QLF using maximum likelihood estimation. With the faint-end slope of the QLF fixed as alpha = -2.03 from previous deeper samples, the best fit of our QLF gives a flatter bright end slope beta = -3.58+/-0.24 and a fainter break magnitude M*1450 = -26.98+/-0.23 than previous studies at similar redshift. Combined with previous work at lower and higher redshifts, our result is consistent with a luminosity evolution and density evolution (LEDE) model. Using the best fit QLF, the contribution of quasars to the ionizing background at z ~ 5 is found to be 18% - 45% with a clumping factor C of 2 - 5. Our sample suggests an evolution of radio loud fraction with optical luminosity but no obvious evolution with redshift.
Comment: 14 pages, 12 figures, Accepted by ApJ
Document Type: Working Paper
DOI: 10.3847/0004-637X/829/1/33
Access URL: http://arxiv.org/abs/1607.04415
Accession Number: edsarx.1607.04415
Database: arXiv
More Details
DOI:10.3847/0004-637X/829/1/33