机构:
Yonsei Univ, Dept Astron, Seoul 120749, South Korea
Yonsei Univ, Yonsei Univ Observ, Seoul 120749, South KoreaETH, Dept Phys, Inst Astron, CH-8093 Zurich, Switzerland
galaxies: active;
galaxies: nuclei;
galaxies: Seyfert;
galaxies: statistics;
methods: data analysis;
quasars: general;
ACTIVE GALACTIC NUCLEI;
DIGITAL SKY SURVEY;
STAR-FORMATION RATE;
SUPERMASSIVE BLACK-HOLES;
HOST GALAXIES;
SEYFERT-GALAXIES;
PARAMETER-ESTIMATION;
QUASAR FRACTION;
LOW-LUMINOSITY;
LINE SPECTRA;
D O I:
10.1088/0067-0049/219/1/1
中图分类号:
P1 [天文学];
学科分类号:
0704 ;
摘要:
We have recently identified a substantial number of type 1 active galactic nuclei (AGNs) featuring weak broad-line regions (BLRs) at z < 0.2 from detailed analysis of galaxy spectra in the Sloan Digital Sky Survey Data Release 7. These objects predominantly show a stellar continuum but also a broad H alpha emission line, indicating the presence of a low-luminosity AGN oriented so that we are viewing the central engine directly without significant obscuration. These accreting black holes have previously eluded detection due to their weak nature. The newly discovered BLR AGNs have increased the number of known type 1 AGNs by 49%. Some of these new BLR AGNs were detected with the Chandra X-ray Observatory, and their X-ray properties confirm that they are indeed type 1 AGNs. Based on our new and more complete catalog of type 1 AGNs, we derived the type 1 fraction of AGNs as a function of [O III] lambda 5007 emission luminosity and explored the possible dilution effect on obscured AGNs due to star formation. The new type 1 AGN fraction shows much more complex behavior with respect to black hole mass and bolometric luminosity than has been suggested previously by the existing receding torus model. The type 1 AGN fraction is sensitive to both of these factors, and there seems to be a sweet spot (ridge) in the diagram of black hole mass and bolometric luminosity. Furthermore, we present the possibility that the Eddington ratio plays a role in determining opening angles.
机构:
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USACALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
Assef, R. J.
;
Stern, D.
论文数: 0引用数: 0
h-index: 0
机构:
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USACALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
Stern, D.
;
Kochanek, C. S.
论文数: 0引用数: 0
h-index: 0
机构:
Ohio State Univ, Dept Astron, Columbus, OH 43210 USA
Ohio State Univ, Ctr Cosmol & Astroparticle Phys, Columbus, OH 43210 USACALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
Kochanek, C. S.
;
Blain, A. W.
论文数: 0引用数: 0
h-index: 0
机构:
Univ Leicester, Leicester LE1 7RH, Leics, EnglandCALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
Blain, A. W.
;
Brodwin, M.
论文数: 0引用数: 0
h-index: 0
机构:CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
Brodwin, M.
;
Brown, M. J. I.
论文数: 0引用数: 0
h-index: 0
机构:
Univ Missouri, Dept Phys, Kansas City, MO 64110 USA
Monash Univ, Sch Phys, Clayton, Vic 3800, AustraliaCALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
Brown, M. J. I.
;
Donoso, E.
论文数: 0引用数: 0
h-index: 0
机构:
CALTECH, Infrared Proc & Anal Ctr, Pasadena, CA 91125 USA
ICATE, RA-5400 San Juan, ArgentinaCALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
Donoso, E.
;
Eisenhardt, P. R. M.
论文数: 0引用数: 0
h-index: 0
机构:CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
Eisenhardt, P. R. M.
;
Jannuzi, B. T.
论文数: 0引用数: 0
h-index: 0
机构:
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
Univ Arizona, Steward Observ, Tucson, AZ 85721 USACALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
Jannuzi, B. T.
;
Jarrett, T. H.
论文数: 0引用数: 0
h-index: 0
机构:
CALTECH, Infrared Proc & Anal Ctr, Pasadena, CA 91125 USA
Univ Cape Town, Dept Astron, ZA-7700 Rondebosch, South AfricaCALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
Jarrett, T. H.
;
Stanford, S. A.
论文数: 0引用数: 0
h-index: 0
机构:
Univ Calif Davis, Dept Phys, Davis, CA 95616 USA
Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USACALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
Stanford, S. A.
;
Tsai, C. -W.
论文数: 0引用数: 0
h-index: 0
机构:
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USACALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
Tsai, C. -W.
;
Wu, J.
论文数: 0引用数: 0
h-index: 0
机构:
UCLA Astron, Los Angeles, CA 90095 USACALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
Wu, J.
;
Yan, L.
论文数: 0引用数: 0
h-index: 0
机构:
CALTECH, Infrared Proc & Anal Ctr, Pasadena, CA 91125 USACALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
机构:
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USACALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
Assef, R. J.
;
Stern, D.
论文数: 0引用数: 0
h-index: 0
机构:
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USACALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
Stern, D.
;
Kochanek, C. S.
论文数: 0引用数: 0
h-index: 0
机构:
Ohio State Univ, Dept Astron, Columbus, OH 43210 USA
Ohio State Univ, Ctr Cosmol & Astroparticle Phys, Columbus, OH 43210 USACALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
Kochanek, C. S.
;
Blain, A. W.
论文数: 0引用数: 0
h-index: 0
机构:
Univ Leicester, Leicester LE1 7RH, Leics, EnglandCALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
Blain, A. W.
;
Brodwin, M.
论文数: 0引用数: 0
h-index: 0
机构:CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
Brodwin, M.
;
Brown, M. J. I.
论文数: 0引用数: 0
h-index: 0
机构:
Univ Missouri, Dept Phys, Kansas City, MO 64110 USA
Monash Univ, Sch Phys, Clayton, Vic 3800, AustraliaCALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
Brown, M. J. I.
;
Donoso, E.
论文数: 0引用数: 0
h-index: 0
机构:
CALTECH, Infrared Proc & Anal Ctr, Pasadena, CA 91125 USA
ICATE, RA-5400 San Juan, ArgentinaCALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
Donoso, E.
;
Eisenhardt, P. R. M.
论文数: 0引用数: 0
h-index: 0
机构:CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
Eisenhardt, P. R. M.
;
Jannuzi, B. T.
论文数: 0引用数: 0
h-index: 0
机构:
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
Univ Arizona, Steward Observ, Tucson, AZ 85721 USACALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
Jannuzi, B. T.
;
Jarrett, T. H.
论文数: 0引用数: 0
h-index: 0
机构:
CALTECH, Infrared Proc & Anal Ctr, Pasadena, CA 91125 USA
Univ Cape Town, Dept Astron, ZA-7700 Rondebosch, South AfricaCALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
Jarrett, T. H.
;
Stanford, S. A.
论文数: 0引用数: 0
h-index: 0
机构:
Univ Calif Davis, Dept Phys, Davis, CA 95616 USA
Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USACALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
Stanford, S. A.
;
Tsai, C. -W.
论文数: 0引用数: 0
h-index: 0
机构:
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USACALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
Tsai, C. -W.
;
Wu, J.
论文数: 0引用数: 0
h-index: 0
机构:
UCLA Astron, Los Angeles, CA 90095 USACALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
Wu, J.
;
Yan, L.
论文数: 0引用数: 0
h-index: 0
机构:
CALTECH, Infrared Proc & Anal Ctr, Pasadena, CA 91125 USACALTECH, Jet Prop Lab, Pasadena, CA 91109 USA