SPACE DENSITY OF OPTICALLY SELECTED TYPE 2 QUASARS

Journal Article · Mon Dec 15 04:00:00 EST 2008 · Astronomical Journal (New York, N.Y. Online)

DOI:https://doi.org/10.1088/0004-6256/136/6/2373; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21301233

Reyes, Reinabelle; Strauss, Michael A; Green, Joshua; Shen, Yue ^[1]; Zakamska, Nadia L ^[2]; Krolik, Julian H ^[3]; Richards, Gordon T ^[4]; Anderson, Scott F ^[5]; Schneider, Donald P ^[6]

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1. Princeton University Observatory, Peyton Hall, Princeton, NJ 08544 (United States)
2. Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540 (United States)
3. Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218-2686 (United States)
4. Department of Physics, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States)
5. Astronomy Department, P.O. Box 351580, University of Washington, Seattle, WA 98195 (United States)
6. Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States)

Type 2 quasars are luminous active galactic nuclei whose central regions are obscured by large amounts of gas and dust. In this paper, we present a catalog of type 2 quasars from the Sloan Digital Sky Survey, selected based on their optical emission lines. The catalog contains 887 objects with redshifts z < 0.83; this is 6 times larger than the previous version and is by far the largest sample of type 2 quasars in the literature. We derive the [O III]5007 luminosity function (LF) for 10{sup 8.3} L {sub sun} < L {sub [OIII]} < 10{sup 10} L {sub sun} (corresponding to intrinsic luminosities up to M[2500 A] {approx_equal} -28 mag or bolometric luminosities up to 4 x 10{sup 47} erg s{sup -1}). This LF provides robust lower limits to the actual space density of obscured quasars due to our selection criteria, the details of the spectroscopic target selection, and other effects. We derive the equivalent LF for the complete sample of type 1 (unobscured) quasars and determine the ratio of type 2 to type 1 quasar number densities. Our data constrain this ratio to be at least {approx}1.5:1 for 10{sup 8.3} L {sub sun} < L {sub [OIII]} < 10{sup 9.5} L {sub sun} at z < 0.3, and at least {approx}1.2:1 for L {sub [OIII]} {approx} 10{sup 10} L {sub sun} at 0.3 < z < 0.83. Type 2 quasars are at least as abundant as type 1 quasars in the relatively nearby universe (z {approx}< 0.8) for the highest luminosities.

• OSTI ID: 21301233
• Journal Information: Astronomical Journal (New York, N.Y. Online), Journal Name: Astronomical Journal (New York, N.Y. Online) Journal Issue: 6 Vol. 136; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
99 GENERAL AND MISCELLANEOUS
BOLOMETERS
CATALOGS
DENSITY
DUSTS
GALAXIES
GALAXY NUCLEI
LUMINOSITY
QUASARS
RED SHIFT
UNIVERSE