An Ultra-luminous Quasar with Most Massive Black Hole in the Distant Universe

To date about 40 quasars with redshifts z>6 have been discovered. Each quasar harbors a black hole with a mass of several billion solar masses. The existence of such black holes when the Universe was less than one billion years old presents significant challenges to theories of the formation and growth of black holes and the black hole/galaxy coevolution. 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.

Speaker: 
Xuebing Wu (KIAA/DoA)
Place: 
KIAA-PKU Auditorium
Host: 
Zhuo Li
Time: 
Thursday, March 5, 2015 - 4:00pm