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
Abstract
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.
- Publication:
-
Galaxies at High Redshift and Their Evolution Over Cosmic Time
- Pub Date:
- 2016
- DOI:
- 10.1017/S1743921315010066
- Bibcode:
- 2016IAUS..319...80W
- Keywords:
-
- black hole physics;
- galaxies: active;
- galaxies: nuclei;
- galaxies: evolution;
- quasars: general;
- quasars: emission lines;
- early universe