A SURVEY OF z {approx} 6 QUASARS IN THE SLOAN DIGITAL SKY SURVEY DEEP STRIPE. II. DISCOVERY OF SIX QUASARS AT z {sub AB}>21

Journal Article · Wed Jul 15 04:00:00 EDT 2009 · Astronomical Journal (New York, N.Y. Online)

DOI:https://doi.org/10.1088/0004-6256/138/1/305; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21255685

Linhua, Jiang; Xiaohui, Fan; Fuyan, Bian ^[1]; Annis, James; Huan, Lin ^[2]; Chiu, Kuenley ^[3]; Jester, Sebastian ^[4]; Lupton, Robert H; Strauss, Michael A ^[5]; Richards, Gordon T ^[6]; Malanushenko, Viktor; Malanushenko, Elena ^[7]; Schneider, Donald P ^[8]

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1. Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)
2. Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States)
3. Department of Astronomy, California Institute of Technology, MS 105-24, Pasadena, CA 91125 (United States)
4. Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany)
5. Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)
6. Department of Physics, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States)
7. Apache Point Observatory, P.O. Box 59, Sunspot, NM 88359 (United States)
8. Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States)

We present the discovery of six new quasars at z {approx} 6 selected from the Sloan Digital Sky Survey (SDSS) southern survey, a deep imaging survey obtained by repeatedly scanning a stripe along the celestial equator. The six quasars are about 2 mag fainter than the luminous z {approx} 6 quasars found in the SDSS main survey and 1 mag fainter than the quasars reported in Paper I. Four of them comprise a complete flux-limited sample at 21 < z {sub AB} < 21.8 over an effective area of 195 deg{sup 2}. The other two quasars are fainter than z {sub AB} = 22 and are not part of the complete sample. The quasar luminosity function at z {approx} 6 is well described as a single power law {phi}(L {sub 1450}) {proportional_to} L {sup {beta}} {sub 1450} over the luminosity range -28 < M {sub 1450} < -25. The best-fitting slope {beta} varies from -2.6 to -3.1, depending on the quasar samples used, with a statistical error of 0.3-0.4. About 40% of the quasars discovered in the SDSS southern survey have very narrow Ly{alpha} emission lines, which may indicate small black hole masses and high Eddington luminosity ratios, and therefore short black hole growth timescales for these faint quasars at early epochs.

• OSTI ID: 21255685
• Journal Information: Astronomical Journal (New York, N.Y. Online), Journal Name: Astronomical Journal (New York, N.Y. Online) Journal Issue: 1 Vol. 138; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
99 GENERAL AND MISCELLANEOUS
BLACK HOLES
COSMOLOGY
EMISSION
EQUATOR
ERRORS
LUMINOSITY
MASS
QUASARS