Journal Article

The quasar mass–luminosity plane – I. A sub-Eddington limit for quasars

Charles L. Steinhardt and Martin Elvis

in Monthly Notices of the Royal Astronomical Society

Published on behalf of The Royal Astronomical Society

Volume 402, issue 4, pages 2637-2648
Published in print March 2010 | ISSN: 0035-8711
Published online March 2010 | e-ISSN: 1365-2966 | DOI:
The quasar mass–luminosity plane – I. A sub-Eddington limit for quasars

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We use 62 185 quasars from the Sloan Digital Sky Survey Data Release 5 sample to explore the relationship between black hole mass and luminosity. Black hole masses were estimated based on the widths of their Hβ, Mg ii and C iv lines and adjacent continuum luminosities using standard virial mass estimate scaling laws. We find that, over the range 0.2 < z < 4.0, the most luminous low-mass quasars are at their Eddington luminosity, but the most luminous high-mass quasars in each redshift bin fall short of their Eddington luminosities, with the shortfall of the order of 10 or more at 0.2 < z < 0.6. We examine several potential sources of measurement uncertainty or bias and show that none of them can account for this effect. We also show the statistical uncertainty in virial mass estimation to have an upper bound of ∼0.15 dex, smaller than the 0.4 dex previously reported. We also examine the highest mass quasars in every redshift bin in an effort to learn more about quasars that are about to cease their luminous accretion. We conclude that the quasar mass–luminosity locus contains a number of new puzzles that must be explained theoretically.

Keywords: accretion, accretion discs; black hole physics; galaxies: evolution; galaxies: nuclei; quasars: general

Journal Article.  9576 words.  Illustrated.

Subjects: Astronomy and Astrophysics

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