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Infrared spectroscopic confirmation of z ∼ 2 photometrically selected obscured quasars
被引:4
|作者:
Ishikawa, Yuzo
[1
]
Wang, Ben
[2
,3
]
Zakamska, Nadia L.
[1
,4
]
Richards, Gordon T.
[5
]
Hennawi, Joseph F.
[3
,6
]
Rivera, Angelica B.
[7
]
机构:
[1] Johns Hopkins Univ, Bloomberg Ctr, Dept Phys & Astron, Baltimore, MD 21218 USA
[2] Tsinghua Univ, Dept Astron, Beijing 100084, Peoples R China
[3] Leiden Univ, Leiden Observ, POB 9513, NL-2300 RA Leiden, Netherlands
[4] Princeton Univ, Inst Adv Study, Princeton, NJ 08544 USA
[5] Drexel Univ, Dept Phys, 32 S 32nd St, Philadelphia, PA 19104 USA
[6] UC Santa Barbara, Dept Phys, Broida Hall, Santa Barbara, CA 93106 USA
[7] US Naval Acad, Dept Phys, 572 CHolloway Rd, Annapolis, MD 21402 USA
关键词:
galaxies: high-redshift;
quasars: emission lines;
quasars: general;
quasars: supermassive black holes;
infrared: galaxies;
ACTIVE GALACTIC NUCLEI;
DIGITAL-SKY-SURVEY;
EXTREMELY RED QUASARS;
WISE-SELECTED HOT;
REDSHIFT EXTREMELY RED;
BLACK-HOLE MASSES;
LUMINOSITY FUNCTION;
REDDENED QUASARS;
HOST GALAXIES;
II QUASARS;
D O I:
10.1093/mnras/stad1035
中图分类号:
P1 [天文学];
学科分类号:
0704 ;
摘要:
The census of obscured quasar populations is incomplete and remains a major unsolved problem, especially at higher redshifts, where we expect a greater density of galaxy formation and quasar activity. We present Gemini GNIRS near-infrared spectroscopy of 24 luminous obscured quasar candidates from the Sloan Digital Sky Survey's Stripe 82 region. The targets were photometrically selected using a WISE/W4 selection technique that is optimized to identify IR-bright and heavily reddened/optically obscured targets at z > 1. We detect emission lines of H alpha, H beta, and/or [O iii] in 23 sources allowing us to measure spectroscopic redshifts in the range 1 < z < 3 with bolometric luminosities spanning L = 10(46.3)-10(47.3) erg s(-1). We observe broad 10(3)-10(4) km s(-1) Balmer emissions with large H alpha/H beta ratios, and we directly observe a heavily reddened rest-frame optical continuum in several sources, suggesting high extinction (A(V) similar to 7-20 mag). Our observations demonstrate that such optical/infrared photometric selection successfully recovers high-redshift obscured quasars. The successful identification of previously undetected red, obscured high-redshift quasar candidates suggests that there are more obscured quasars yet to be discovered.
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页码:350 / 361
页数:12
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