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A Snapshot Survey for Gravitational Lenses Among z>=4.0 Quasars: II. Constraints on the 4.0<z<4.5 Quasar Population

Gordon T. Richards·Zoltan Haiman·Bartosz Pindor·Michael A. Strauss·Xiaohui Fan·Daniel Eisenstein·Donald P. Schneider·Neta A. Bahcall·J. Brinkmann·Masataka Fukugita
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Abstract

We report on i-band snapshot observations of 157 Sloan Digital Sky Survey (SDSS) quasars at 4 -3.8 (3 sigma), assuming a break in the quasar luminosity function at M_1450^star=-24.5. This constraint is considerably stronger than the limit of beta>-4.63 obtained from the absence of lensing in four z>5.7 quasars. Such constraints are important for our understanding of the true space density of high-redshift quasars and the ionization state of the early universe.

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Gordon T. Richards, Zoltan Haiman, Bartosz Pindor, Michael A. Strauss, Xiaohui Fan, Daniel Eisenstein, Donald P. Schneider, Neta A. Bahcall, J. Brinkmann, Masataka Fukugita. 2005-09-06. A Snapshot Survey for Gravitational Lenses Among z>=4.0 Quasars: II. Constraints on the 4.0<z<4.5 Quasar Population. https://doi.org/10.1086/498063

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