Discovery of a 12 billion solar mass black hole at redshift 6.3 and its challenge to the black hole/galaxy coevolution at cosmic dawn

Xue Bing Wu, Feige Wang, Xiaohui Fan, Weimin Yi, Wenwen Zuo, Fuyan Bian, Linhua Jiang, Ian D. McGreer, Ran Wang, Jinyi Yang, Qian Yang, David Thompson, Yuri Beletsky

Research output: Contribution to journalArticle

1 Scopus citations


The existence of black holes with masses of about one billion solar masses in quasars at redshifts z > 6 presents significant challenges to theories of the formation and growth of black holes and the black hole/galaxy co-evolution in the early Universe. Here we 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 at z > 6 provides a unique laboratory to the study of the mass assembly and galaxy formation around the most massive black holes at cosmic dawn. It raises further challenges to the black hole/galaxy co-evolution in the epoch of cosmic reionization because the black hole needs to grow much faster than the host galaxy.

Original languageEnglish (US)
Pages (from-to)80-83
Number of pages4
JournalProceedings of the International Astronomical Union
Publication statusPublished - 2015


  • black hole physics
  • early universe
  • galaxies: active
  • galaxies: evolution
  • galaxies: nuclei
  • quasars: emission lines
  • quasars: general

ASJC Scopus subject areas

  • Astronomy and Astrophysics

Cite this