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arXiv · 0708.2578

A Survey of z~6 Quasars in the SDSS Deep Stripe: I. a Flux-Limited Sample at z_{AB}<21

Linhua Jiang·Xiaohui Fan·James Annis·Robert H. Becker·Richard L. White·Kuenley Chiu·Huan Lin·Robert H. Lupton·Gordon T. Richards·Michael A. Strauss·Sebastian Jester·Donald P. Schneider
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Abstract

We present the discovery of five quasars at z~6 selected from 260 deg^2 of the Sloan Digital Sky Survey (SDSS) southern survey, a deep imaging survey obtained by repeatedly scanning a stripe along the Celestial Equator. The five quasars with 20 =6.0 and =-25.8 is (5.0+/-2.1) x 10^{-9} Mpc^{-3} mag^{-1}. We model the bright-end quasar luminosity function (QLF) at z~6 as a power law Phi(L_{1450}) \propto L_{1450}^{beta}. The slope beta calculated from a combination of our sample and the luminous SDSS quasar sample is -3.1+/-0.4, significantly steeper than the slope of the QLF at z~4. Based on the derived QLF, we find that the quasar/AGN population cannot provide enough photons to ionize the intergalactic medium (IGM) at z~6 unless the IGM is very homogeneous and the luminosity (L*_{1450}) at which the QLF power law breaks is very low.

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Linhua Jiang, Xiaohui Fan, James Annis, Robert H. Becker, Richard L. White, Kuenley Chiu, Huan Lin, Robert H. Lupton, Gordon T. Richards, Michael A. Strauss, Sebastian Jester, Donald P. Schneider. 2007-08-20. A Survey of z~6 Quasars in the SDSS Deep Stripe: I. a Flux-Limited Sample at z_{AB}<21. https://doi.org/10.1088/0004-6256/135/3/1057

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