Rest-frame optical spectra and black hole masses of 3 < z < 6 quasars

Journal Article · Wed Jun 10 04:00:00 EDT 2015 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/806/1/109· OSTI ID:22883075

Jun, Hyunsung David ^[1]; Im, Myungshin; Kim, Dohyeong; Kim, Ji Hoon ^[2]; Lee, Hyung Mok; Woo, Jong-Hak; Lee, Myung Gyoon ^[3]; Ohyama, Youichi ^[4]; Fan, Xiaohui ^[5]; Goto, Tomotsugu ^[6]; Kim, Minjin ^[7]; Nakagawa, Takao ^[8]; Pearson, Chris; Serjeant, Stephen ^[9]

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1. Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA 91109 (United States)
2. Center for the Exploration of the Origin of the universe (CEOU), Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of)
3. Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of)
4. Academia Sinica, Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 10617, Taiwan (China)
5. Steward Observatory, The University of Arizona, Tucson, AZ 85721 (United States)
6. Institute of Astronomy and Department of Physics, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu, 30013, Taiwan (China)
7. Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of)
8. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara, Kanagawa 252-5210 (Japan)
9. Department of Physical Sciences, The Open University, Milton Keynes, MK7 6AA (United Kingdom)

We present the rest-frame optical spectral properties of 155 luminous quasars at 3.3 < z < 6.4 taken with the AKARI space telescope, including the first detection of the Hα emission line as far out as z ∼ 6. We extend the scaling relation between the rest-frame optical continuum and the line luminosity of active galactic nuclei (AGNs) to the high-luminosity, high-redshift regime that has rarely been probed before. Remarkably, we find that a single log-linear relation can be applied to the 5100 Å and Hα AGN luminosities over a wide range of luminosity (10{sup 42} < L{sub 5100} < 10{sup 47} ergs s{sup −1}) or redshift (0 < z < 6), suggesting that the physical mechanism governing this relation is unchanged from z = 0 to 6, over five decades in luminosity. Similar scaling relations are found between the optical and the UV continuum luminosities or line widths. Applying the scaling relations to the Hβ black hole (BH) mass (M{sub BH}) estimator of local AGNs, we derive the M{sub BH} estimators based on the Hα, Mg ii, and C iv lines, finding that the UV-line-based masses are overall consistent with the Balmer-line-based, but with a large intrinsic scatter of 0.40 dex for the C iv estimates. Our 43 M{sub BH} estimates from Hα confirm the existence of BHs as massive as ∼ 10{sup 10} M{sub ⊙} out to z ∼ 5 and provide a secure footing for previous results from Mg ii-line-based studies that a rapid M{sub BH} growth has occurred in the early universe.

• OSTI ID: 22883075
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 806; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United Kingdom
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
BALMER LINES
BLACK HOLES
DETECTION
EMISSION
GALACTIC EVOLUTION
GALAXIES
GALAXY NUCLEI
LINE WIDTHS
LUMINOSITY
MASS
QUASARS
RED SHIFT
SPACE
SPECTRA
TELESCOPES
UNIVERSE