The DOI matches its Crossref record; 5 of the 5 references it cites were found in a registry or an index.
SPACE DENSITY OF OPTICALLY SELECTED TYPE 2 QUASARS
Open accessAbstract
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 8.3 L ☉ < L [O iii ] < 10 10 L ☉ (corresponding to intrinsic luminosities up to M [2500 Å] ≃ −28 mag or bolometric luminosities up to 4 × 10 47 erg s −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 ∼1.5:1 for 10 8.3 L ☉ < L [O iii ] < 10 9.5 L ☉ at z < 0.3, and at least ∼1.2:1 for L [O iii ] ∼ 10 10 L ☉ at 0.3 < z < 0.83. Type 2 quasars are at least as abundant as type 1 quasars in the relatively nearby universe ( z ≲ 0.8) for the highest luminosities.
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Schlegel, D. J., Finkbeiner, D. P., & Davis, M. (1998) · The Astrophysical Journal · doi:10.1086/305772 · Cited by 15,126
The Sloan Digital Sky Survey Photometric System
Fukugita, M., Ichikawa, T., Gunn, J. E., Doi, M., Shimasaku, K., & Schneider, D. P. (1996) · The Astronomical Journal · doi:10.1086/117915 · Cited by 3,033
Self-citationThe Sloan Digital Sky Survey Photometric Camera
Gunn, J. E., Carr, M., Rockosi, C., Sekiguchi, M., Berry, K., Elms, B., de Haas, E., Ivezić, Ž., Knapp, G., Lupton, R., et al. (1998) · The Astronomical Journal · doi:10.1086/300645 · Cited by 1,692
Self-citationAstrometric Calibration of the Sloan Digital Sky Survey
Pier, J. R., Munn, J. A., Hindsley, R. B., Hennessy, G. S., Kent, S. M., Lupton, R. H., & Ivezić, Ž. (2003) · The Astronomical Journal · doi:10.1086/346138 · Cited by 908
An Improved Photometric Calibration of the Sloan Digital Sky Survey Imaging Data
Padmanabhan, N., Schlegel, D. J., Finkbeiner, D. P., Barentine, J. C., Blanton, M. R., Brewington, H. J., Gunn, J. E., Harvanek, M., Hogg, D. W., Ivezić, Ž., et al. (2008) · The Astrophysical Journal · doi:10.1086/524677 · Cited by 591
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A CATALOG OF QUASAR PROPERTIES FROM SLOAN DIGITAL SKY SURVEY DATA RELEASE 7
Shen, Y., Richards, G. T., Strauss, M. A., Hall, P. B., Schneider, D. P., Snedden, S., Bizyaev, D., Brewington, H., Malanushenko, V., Malanushenko, E., et al. (2011) · The Astrophysical Journal Supplement Series · doi:10.1088/0067-0049/194/2/45 · Cited by 1,517
Self-citationRevisiting the Unified Model of Active Galactic Nuclei
Netzer, H. (2015) · Annual Review of Astronomy and Astrophysics · doi:10.1146/annurev-astro-082214-122302 · Cited by 865
Bolton, A. S., Schlegel, D. J., Aubourg, É., Bailey, S., Bhardwaj, V., Brownstein, J. R., Burles, S., Chen, Y.-M., Dawson, K., Eisenstein, D. J., et al. (2012) · The Astronomical Journal · doi:10.1088/0004-6256/144/5/144 · Cited by 667
Self-citationActive galactic nuclei: what’s in a name?
Padovani, P., Alexander, D. M., Assef, R. J., De Marco, B., Giommi, P., Hickox, R. C., Richards, G. T., Smolčić, V., Hatziminaoglou, E., Mainieri, V., et al. (2017) · The Astronomy and Astrophysics Review · doi:10.1007/s00159-017-0102-9 · Cited by 666
Self-citationAGN wind scaling relations and the co-evolution of black holes and galaxies
Fiore, F., Feruglio, C., Shankar, F., Bischetti, M., Bongiorno, A., Brusa, M., Carniani, S., Cicone, C., Duras, F., Lamastra, A., et al. (2017) · Astronomy & Astrophysics · doi:10.1051/0004-6361/201629478 · Cited by 601
Metadata
- Authors
- Reyes, R., Zakamska, N. L., Strauss, M. A., Green, J., Krolik, J. H., Shen, Y., Richards, G. T., Anderson, S. F., & Schneider, D. P.
- Venue
- The Astronomical Journal
- Publisher
- American Astronomical Society
- Published
- 2008-11-10
- Volume
- 136
- Issue
- 6
- Pages
- 2373-2390
- ISSN
- 0004-6256 (ISSN-L)
- 1538-3881
- OpenAlex
- W2049430551
- Cited by
- 303
- References
- 5
- FWCI
- 9.43
- Type
- journal article
- Language
- en
- Open access
- bronze
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- Reyes, R., Zakamska, N. L., Strauss, M. A., Green, J., Krolik, J. H., Shen, Y., Richards, G. T., Anderson, S. F., & Schneider, D. P. (2008). SPACE DENSITY OF OPTICALLY SELECTED TYPE 2 QUASARS. The Astronomical Journal. https://doi.org/10.1088/0004-6256/136/6/2373
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