简介: |
To date about 40 quasars with redshifts z>6 have been discovered. Each quasar harbors a black hole with a mass of about one billion solar masses. The existence of such black holes when the Universe was less than one billion years after the Big Bang presents significant challenges to theories of the formation and growth of black holes and the black hole/galaxy co-evolution. I will report a recent discovery of an ultra-luminous quasar at redshift z=6.30, which has an observed optical and near-infrared luminosity a few times greater than those of previously known z>6 quasars. With near-infrared spectroscopy, we obtain a black hole mass of about 12 billion solar masses, which is well consistent with the mass derived by assuming an Eddington-limited accretion. This ultra-luminous quasar with a 12 billion solar mass black hole at z>6 provides a unique laboratory to the study of the mass assembly and galaxy formation around the most massive black holes in the early Universe.
个人简介:Prof. Xue-Bing Wu, an associate director of Kavli Institute for Astronomy and Astrophysics at Peking University. He obtained his Ph.D. at Beijing Astronomical Observatory, Chinese Academy of Sciences (CAS) in 1996. He was a postdoctoral researcher at Institute of Theoretical Physics, CAS in 1996-1998, and a research associate at Beijing Astronomical Observatory, CAS in 1998-2000. He joined Department of Astronomy of Peking University as an associate professor in 2000, and became a professor in 2001. His research interests mainly include quasars and active galactic nuclei (AGNs), supermassive black holes and their accretion physics.
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