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A Survey of z>5.7 Quasars in the Sloan Digital Sky Survey IV: Discovery of Seven Additional Quasars

Xiaohui Fan·Michael A. Strauss·Gordon T. Richards·Joseph F. Hennawi·Robert H. Becker·Richard L. White·Aleksandar M. Diamond-Stanic·Jennifer L. D onley·Linhua Jiang·J. Serena Kim·Marianne Vestergaard·Jason E. Young·James E. Gunn·Robert H. Lupton·Gillian R. Knapp·Donald P. Schneider·W. N. Brandt·Neta A. Bahcall·J. C. Barentine·J. Brinkmann·Howard J. Brewington·Masataka F ukugita·Michael Harvanek·S. J. Kleinman·Jurek Krzesinski·Dan Long·Eric H. N eilsen, Jr.·Atsuko Nitta·Stephanie A. Snedden·Wolfgang Voges
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Abstract

We present the discovery of seven quasars at z>5.7, selected from ~2000 deg^2 of multicolor imaging data of the Sloan Digital Sky Survey (SDSS). The new quasars have redshifts z from 5.79 to 6.13. Five are selected as part of a complete flux-limited sample in the SDSS Northern Galactic Cap; two have larger photometric errors and are not part of the complete sample. One of the new quasars, SDSS J1335+3533 (z=5.93), exhibits no emission lines; the 3-sigma limit on the rest-frame equivalent width of Ly alpha+NV line is 5 A. It is the highest redshift lineless quasar known, and could be a gravitational lensed galaxy, a BL Lac object or a new type of quasar. Two new z>6 quasars, SDSS 1250+3130 (z=6.13) and SDSS J1137+3549 (z=6.01), show deep Gunn-Peterson absorption gaps in Ly alpha. These gaps are narrower the complete Gunn-Peterson absorption troughs observed among quasars at z>6.2 and do not have complete Ly beta absorption.

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Xiaohui Fan, Michael A. Strauss, Gordon T. Richards, Joseph F. Hennawi, Robert H. Becker, Richard L. White, Aleksandar M. Diamond-Stanic, Jennifer L. D onley, Linhua Jiang, J. Serena Kim, Marianne Vestergaard, Jason E. Young, James E. Gunn, Robert H. Lupton, Gillian R. Knapp, Donald P. Schneider, W. N. Brandt, Neta A. Bahcall, J. C. Barentine, J. Brinkmann, Howard J. Brewington, Masataka F ukugita, Michael Harvanek, S. J. Kleinman, Jurek Krzesinski, Dan Long, Eric H. N eilsen, Jr., Atsuko Nitta, Stephanie A. Snedden, Wolfgang Voges. 2005-12-04. A Survey of z>5.7 Quasars in the Sloan Digital Sky Survey IV: Discovery of Seven Additional Quasars. https://doi.org/10.1086/500296

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