The deep Groth Strip Survey. VI. Spectroscopic, variability, and X-ray detection of active galactic nuclei

被引:31
作者
Sarajedini, Vicki L. [1 ]
Koo, David C.
Phillips, Andrew C.
Kobulnicky, Henry A.
Gebhardt, Karl
Willmer, Christopher N. A.
Vogt, Nicole P.
Laird, Elise
Im, Myungshin
Iverson, Sarah
Mattos, Wanessa
机构
[1] Univ Florida, Dept Astron, Gainesville, FL 32611 USA
[2] Univ Calif Santa Cruz, Univ Calif Observ, Lick Observ, Santa Cruz, CA 95064 USA
[3] Univ Wyoming, Dept Phys & Astron, Laramie, WY 82071 USA
[4] Univ Texas, Dept Astron, Austin, TX 78723 USA
[5] New Mexico State Univ, Dept Astron, Las Cruces, NM 88003 USA
[6] Univ London Imperial Coll Sci Technol & Med, Astrophys Grp, London SW7 2AZ, England
[7] Seoul Natl Univ, Astron Program, SEES, Seoul, South Korea
[8] Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA
关键词
galaxies : active; surveys;
D O I
10.1086/505909
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We identify active galactic nuclei (AGNs) in the Groth-Westphal Survey Strip (GSS) using the independent and complementary selection techniques of optical spectroscopy and photometric variability. We discuss the X-ray properties of these AGNs using Chandra/XMM-Newton data for this region. From a sample of 576 galaxies with high-quality spectra we identify 31 galaxies with AGN signatures. Seven of these have broad emission lines (Type 1 AGNs). We also identify 26 galaxies displaying nuclear variability in Hubble Space Telescope Wide Field Planetary Camera 2 (HST WFPC2) images of the GSS separated by similar to 7 yr. The primary overlap of the two selected AGN samples is the set of broad-line AGNs, of which 80% appear as variable. Only a few narrow-line AGNs approach the variability threshold. The broad-line AGNs have an average redshift of < z > similar or equal to 1.1, while the other spectroscopic AGNs have redshifts closer to the mean of the general galaxy population (< z > similar or equal to 0: 7). Eighty percent of the identified broad-line AGNs are detected in X-rays, and these are among the most luminous X-ray sources in the GSS. Only one narrow-line AGN is X-ray detected. Of the variable nuclei galaxies within the X-ray survey, 27% are X-ray detected. We find that 1.9% +/- 0.6% of GSS galaxies to V-gal = 24 are broad-line AGNs, 1.4% +/- 0.5% are narrow-line AGNs, and 4.5% +/- 1.4% contain variable nuclei. The fraction of spectroscopically identified BLAGNs and NLAGNs at z similar to 1 reveals a marginally significant increase of 1.3% +/- 0.9% when compared to the local population.
引用
收藏
页码:69 / 88
页数:20
相关论文
共 61 条
[1]  
Barger A. J., 2003, APJ, V584, P61
[2]   Optical and infrared properties of the 2 Ms Chandra Deep Field North X-ray sources [J].
Barger, AJ ;
Cowie, LL ;
Capak, P ;
Alexander, DM ;
Bauer, FE ;
Fernandez, E ;
Brandt, WN ;
Garmire, GP ;
Hornschemeier, AE .
ASTRONOMICAL JOURNAL, 2003, 126 (02) :632-665
[3]   The first radio-loud broad absorption line QSO and evidence for a hidden population of quasars [J].
Becker, RH ;
Gregg, MD ;
Hook, IM ;
McMahon, RG ;
White, RL ;
Helfand, DJ .
ASTROPHYSICAL JOURNAL, 1997, 479 (02) :L93-L96
[4]   Variable extended objects in Selected Area 57 [J].
Bershady, MA ;
Trevese, D ;
Kron, RG .
ASTROPHYSICAL JOURNAL, 1998, 496 (01) :103-116
[5]  
BIRETTA J, 2001, BAAS, V198, P402
[6]   The 2dF QSO Redshift Survey - I. The optical luminosity function of quasi-stellar objects [J].
Boyle, BJ ;
Shanks, T ;
Croom, SM ;
Smith, RJ ;
Miller, L ;
Loaring, N ;
Heymans, C .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2000, 317 (04) :1014-1022
[7]   THE OPTICAL LUMINOSITY FUNCTION OF SEYFERT-1 NUCLEI [J].
CHENG, FZ ;
DANESE, L ;
DEZOTTI, G ;
FRANCESCHINI, A .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1985, 212 (04) :857-871
[8]   Clues to active galactic nucleus growth from optically variable objects in the hubble ultra deep field [J].
Cohen, SH ;
Ryan, RE ;
Straughn, AN ;
Hathi, NP ;
Windhorst, RA ;
Koekemoer, AM ;
Pirzkal, N ;
Xu, C ;
Mobasher, B ;
Malhotra, S ;
Strolger, LG ;
Rhoads, JE .
ASTROPHYSICAL JOURNAL, 2006, 639 (02) :731-739
[9]   Science objectives and early results of the DEEP2 Redshift Survey [J].
Davis, M ;
Faber, SM ;
Newman, JA ;
Phillips, AC ;
Ellis, RS ;
Steidel, CC ;
Conselice, C ;
Coil, AL ;
Finkbeiner, DP ;
Koo, DC ;
Guhathakurta, P ;
Weiner, B ;
Schiavon, R ;
Willmer, C ;
Kaiser, N ;
Luppino, G ;
Wirth, G ;
Connolly, A ;
Eisenhardt, P ;
Cooper, M ;
Gerke, B .
DISCOVERIES AND RESEARCH PROSPECTS FROM 6- TO 10- METER-CLASS TELESCOPES II, 2003, 4834 :161-172
[10]   The DEIMOS spectrograph for the Keck II telescope: integration and testing [J].
Faber, SM ;
Phillips, AC ;
Kibrick, RI ;
Alcott, B ;
Allen, SL ;
Burrous, J ;
Cantrall, T ;
Clarke, DA ;
Coil, AL ;
Cowley, DJ ;
Davis, M ;
Deich, WTS ;
Dietsch, K ;
Gilmore, DK ;
Harper, CA ;
Hilyard, DF ;
Lewis, JP ;
McVeigh, MM ;
Newman, J ;
Osborne, J ;
Schiavon, RP ;
Stover, RJ ;
Tucker, D ;
Wallace, V ;
Wei, MZ ;
Wirth, GD ;
Wright, CA .
INSTRUMENT DESIGN AND PERFORMANCE FOR OPTICAL/INFRARED GROUND-BASED TELESCOPES, PTS 1-3, 2003, 4841 :1657-1669