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Title: Ultraviolet excess of luminous quasars. II. Evidence for massive accretion disks

Journal Article · · Astrophys. J.; (United States)
DOI:https://doi.org/10.1086/160981· OSTI ID:5518425

This paper presents new infrared, optical, and ultraviolet spectra of three high-redshift quasars. They are analyzed along with three published quasar spectra. After accounting for other sources of radiation, the continua are fitted with spectra predicted for optically thick steady-state accretion disks which include the effects of general relativity. The two fitting parameters, the mass of the accreting black hole and the accretion rate, are determined by the data with a formal accuracy of 20%. The masses range from 0.2--0.5 billion M/sub sun/ for 3C 273 and PKS 0405--123 to 1--3 billion M/sub sun/ for the high-redshift quasars. The values depend on the assumed disk inclination and the angular momentum of the hole. The high luminosities of these six quasars are all within a factor of 2 of their Eddington limits, and this conclusion is not extremely sensitive to the modeling assumptions.

Research Organization:
Palomar Observatory, California Institute of Technology
OSTI ID:
5518425
Journal Information:
Astrophys. J.; (United States), Vol. 268:2
Country of Publication:
United States
Language:
English