A thirty-four billion solar mass black hole in SMSS J2157-3602, the most luminous known quasar

Abstract

From near-infrared spectroscopic measurements of the Mg II emission line doublet, we estimate the black hole (BH) mass of the quasar, SMSS J215728.21-360215.1, as being (3.4 +/- 0.6) x 10(10) M circle dot and refine the redshift of the quasar to be z = 4.692. SMSS J2157 is the most luminous known quasar, with a 3000 angstrom luminosity of (4.7 +/- 0.5) x 10(47) erg s(-1) and an estimated bolometric luminosity of 1.6 x 10(48) erg s(-1), yet its Eddington ratio is only similar to 0.4. Thus, the high luminosity of this quasar is a consequence of its extremely large BH - one of the most massive BHs at z > 4. Show more