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arXiv · 0903.4136

Downsizing of supermassive black holes from the SDSS quasar survey

Marzia Labita·Roberto Decarli·Aldo Treves·Renato Falomo
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Abstract

Starting from the ~50000 quasars of the Sloan Digital Sky Survey for which MgII line width and 3000 A monochromatic flux are available, we aim to study the dependence of the mass of active black holes on redshift. We focus on the observed distribution in the FWHM - nuclear luminosity plane, which can be reproduced at all redshifts assuming a limiting BH mass, a maximum Eddington ratio and a minimum luminosity (due to the survey flux limit). We study the z-dependence of the best fit parameters of assumed distributions at increasing redshift and find that the maximum mass of the quasar population evolves as log[M_BH(max)/M_Sun]~0.3z+9, while the maximum Eddington ratio (~0.45) is practically independent of cosmic time. These results are unaffected by the Malmquist bias.

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Marzia Labita, Roberto Decarli, Aldo Treves, Renato Falomo. 2009-03-24. Downsizing of supermassive black holes from the SDSS quasar survey. https://doi.org/10.1111/j.1365-2966.2009.14812.x

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