title: An ultraluminous quasar with a twelve-billion-solar-mass black hole at redshift 6.30.
abstract: So far, roughly 40 quasars with redshifts greater than z = 6 have been discovered. Each quasar contains a black hole with a mass of about one billion solar masses (10(9) M Sun symbol). The existence of such black holes when the Universe was less than one billion years old presents substantial challenges to theories of the formation and growth of black holes and the coevolution of black holes and galaxies. Here we report the discovery of an ultraluminous quasar, SDSS J010013.02+280225.8, at redshift z = 6.30. It has an optical and near-infrared luminosity a few times greater than those of previously known z > 6 quasars. On the basis of the deep absorption trough on the blue side of the Lyman-α emission line in the spectrum, we estimate the proper size of the ionized proximity zone associated with the quasar to be about 26 million light years, larger than found with other z > 6.1 quasars with lower luminosities. We estimate (on the basis of a near-infrared spectrum) that the black hole has a mass of ∼1.2 × 10(10) M Sun symbol, which is consistent with the 1.3 × 10(10) M Sun symbol derived by assuming an Eddington-limited accretion rate.
authors.affiliation: 1] Department of Astronomy, School of Physics, Peking University, Beijing 100871, China [2] Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871, China.
authors.forename: Xue-Bing
authors.initials: XB
authors.lastname: Wu
authors.affiliation: 1] Department of Astronomy, School of Physics, Peking University, Beijing 100871, China [2] Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871, China.
authors.forename: Feige
authors.initials: F
authors.lastname: Wang
authors.affiliation: 1] Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871, China [2] Steward Observatory, University of Arizona, Tucson, Arizona 85721-0065, USA.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Fan
authors.affiliation: 1] Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011, China [2] University of Chinese Academy of Sciences, Beijing 100049, China [3] Key Laboratory for the Structure and Evolution of Celestial Objects, Chinese Academy of Sciences, Kunming 650011, China.
authors.forename: Weimin
authors.initials: W
authors.lastname: Yi
authors.affiliation: Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030, China.
authors.forename: Wenwen
authors.initials: W
authors.lastname: Zuo
authors.affiliation: Mount Stromlo Observatory, Research School of Astronomy and Astrophysics, Australian National University, Weston Creek, Australian Capital Territory 2611, Australia.
authors.forename: Fuyan
authors.initials: F
authors.lastname: Bian
authors.affiliation: Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871, China.
authors.forename: Linhua
authors.initials: L
authors.lastname: Jiang
authors.affiliation: Steward Observatory, University of Arizona, Tucson, Arizona 85721-0065, USA.
authors.forename: Ian D
authors.initials: ID
authors.lastname: McGreer
authors.affiliation: Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871, China.
authors.forename: Ran
authors.initials: R
authors.lastname: Wang
authors.affiliation: 1] Department of Astronomy, School of Physics, Peking University, Beijing 100871, China [2] Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871, China.
authors.forename: Jinyi
authors.initials: J
authors.lastname: Yang
authors.affiliation: 1] Department of Astronomy, School of Physics, Peking University, Beijing 100871, China [2] Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Yang
authors.affiliation: Large Binocular Telescope Observatory, University of Arizona, Tucson, Arizona 85721, USA.
authors.forename: David
authors.initials: D
authors.lastname: Thompson
authors.affiliation: Las Campanas Observatory, Carnegie Institution of Washington, Colina el Pino, Casilla 601, La Serena, Chile.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Beletsky