TY - JOUR
T1 - An Optically Faint Quasar Survey at z ∼ 5 in the CFHTLS Wide Field
T2 - Estimates of the Black Hole Masses and Eddington Ratios
AU - Ikeda, H.
AU - Nagao, T.
AU - Matsuoka, K.
AU - Kawakatu, N.
AU - Kajisawa, M.
AU - Akiyama, M.
AU - Miyaji, T.
AU - Morokuma, T.
N1 - Funding Information:
Funding for SDSS-III has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, and the U.S. Department of Energy Office of Science. The SDSS-III website is http://www.sdss3.org/. SDSS-III is managed by the Astrophysical Research Consortium for the Participating Institutions of the SDSS-III Collaboration including the University of Arizona, the Brazilian Participation Group, Brookhaven National Laboratory, Carnegie Mellon University, University of Florida, the French Participation Group, the German Participation Group, Harvard University, the Instituto de Astrofisica de Canarias, the Michigan State/Notre Dame/JINA Participation Group, Johns Hopkins University, Lawrence Berkeley National Laboratory, Max Planck Institute for Astrophysics, Max Planck Institute for Extraterrestrial Physics, New Mexico State University, New York University, Ohio State University, Pennsylvania State University, University of Portsmouth, Princeton University, the Spanish Participation Group, University of Tokyo, University of Utah, Vanderbilt University, University of Virginia, University of Washington, and Yale University.
Funding Information:
We thank the anonymous referee for valuable comments that helped to improve this paper. We would also like to thank the Gemini staff for their invaluable help. This work is based on data obtained at the Gemini Observatory via the time exchange program between Gemini and the Subaru Telescope (processed using the Gemini IRAF package). The Gemini Observatory is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the National Research Council (Canada), CONICYT (Chile), Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina), and Ministério da Ciência, Tecnologia e Inovação (Brazil).
Funding Information:
This work was financially supported in part by the Japan Society for the Promotion of Science (JSPS; TN: grant No. 25707010, 16H01101, and 16H03958). T. Miyaji is supported by UNAM-DGAPA Grant PAPIIT IN104216 and CONACyT Grant Investigación Básica 252531. K.M. is financially supported by the JSPS through the JSPS Research Fellowship for research abroad. N.K. acknowledges the financial support of Grant-in-Aid for Young Scientists (B:16K17670). This research used the facilities of the Canadian Astronomy Data Centre operated by the National Research Council of Canada with the support of the Canadian Space Agency. This research made use of Astropy, a community-developed core Python package for Astronomy (Astropy Collaboration et al. 2013). Data analysis was in part carried out on the common use data analysis computer system at the Astronomy Data Center, ADC, of the National Astronomical Observatory of Japan.
Funding Information:
This publication makes use of data products from the Wide- field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration. This research has made use of the NASA/IPAC Infrared Science Archive, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.
Funding Information:
This work is based on observations performed with MegaPrime/MegaCam, a joint project of CFHT and CEA/ DAPNIA, at the Canada–France–Hawaii Telescope (CFHT), which is operated by the National Research Council (NRC) of Canada, the Institut National des Science de l’Univers of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii. This work is based in part on data products produced at the Canadian Astronomy Data Centre as part of the Canada–France–Hawaii Telescope Legacy Survey, a collaborative project of NRC and CNRS. To make contours in Figures 2, 5, and 6, the astroML python package was used (Vanderplas et al. 2012; Ivezić et al. 2014).
Publisher Copyright:
© 2017. The American Astronomical Society. All rights reserved..
PY - 2017/9/1
Y1 - 2017/9/1
N2 - We present the result of our spectroscopic follow-up observation for faint quasar candidates at z ∼ 5 in part of the Canada-France-Hawaii Telescope Legacy Survey wide field. We select nine photometric candidates and identify three z ∼ 5 faint quasars, one z ∼ 4 faint quasar, and a late-type star. Since two faint quasar spectra show the C iv emission line without suffering from a heavy atmospheric absorption, we estimate their black hole masses (MBH) and Eddington ratios (L/LEdd). The inferred logMBH are 9.04 ± 0.14 and 8.53 ± 0.20, respectively. In addition, the inferred are -1.00 ± 0.15 and -0.42 ± 0.22, respectively. If we adopt that L/LEdd = constant or |∞ (1 + Z)2, the seed black hole masses (Msced) of our z ∼ 5 faint quasars are expected to be > 105 MOin most cases. We also compare the observational results with a mass accretion model, where angular momentum is lost due to supernova explosions. Accordingly, of the z ∼ 5 faint quasars in our sample can be explained even if Msced is ∼ 103 Mo. Since z ∼ 6 luminous qusars and our z ∼ 5 faint quasars are not on the same evolutionary track, z ∼ 6 luminous quasars and our z ∼ 5 quasars are not the same populations but different populations, due to the difference of a period of the mass supply from host galaxies. Furthermore, we confirm that one can explain of z ∼ 6 luminous quasars and our z ∼ 5 faint quasars even if their seed black holes are formed at z ∼ 7.
AB - We present the result of our spectroscopic follow-up observation for faint quasar candidates at z ∼ 5 in part of the Canada-France-Hawaii Telescope Legacy Survey wide field. We select nine photometric candidates and identify three z ∼ 5 faint quasars, one z ∼ 4 faint quasar, and a late-type star. Since two faint quasar spectra show the C iv emission line without suffering from a heavy atmospheric absorption, we estimate their black hole masses (MBH) and Eddington ratios (L/LEdd). The inferred logMBH are 9.04 ± 0.14 and 8.53 ± 0.20, respectively. In addition, the inferred are -1.00 ± 0.15 and -0.42 ± 0.22, respectively. If we adopt that L/LEdd = constant or |∞ (1 + Z)2, the seed black hole masses (Msced) of our z ∼ 5 faint quasars are expected to be > 105 MOin most cases. We also compare the observational results with a mass accretion model, where angular momentum is lost due to supernova explosions. Accordingly, of the z ∼ 5 faint quasars in our sample can be explained even if Msced is ∼ 103 Mo. Since z ∼ 6 luminous qusars and our z ∼ 5 faint quasars are not on the same evolutionary track, z ∼ 6 luminous quasars and our z ∼ 5 quasars are not the same populations but different populations, due to the difference of a period of the mass supply from host galaxies. Furthermore, we confirm that one can explain of z ∼ 6 luminous quasars and our z ∼ 5 faint quasars even if their seed black holes are formed at z ∼ 7.
KW - cosmology: observations
KW - quasars: supermassive black holes-surveys
UR - http://www.scopus.com/inward/record.url?scp=85029061083&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85029061083&partnerID=8YFLogxK
U2 - 10.3847/1538-4357/aa83ae
DO - 10.3847/1538-4357/aa83ae
M3 - Article
AN - SCOPUS:85029061083
SN - 0004-637X
VL - 846
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 57
ER -