The disk–torus system in active galactic nuclei: possible evidence of highly spinning black holes
We study the ratio R between the luminosity of the torus and that of the accretion disk, inferred from the relativistic model KERRBB for a sample of approximately 2000 luminosity-selected radio-quiet Type I active galactic nuclei from the Sloan Digital Sky Survey catalog. We find a mean ratio R ≈ 0...
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Published in | Astronomy and astrophysics (Berlin) Vol. 656; p. A96 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Heidelberg
EDP Sciences
01.12.2021
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Subjects | |
Online Access | Get full text |
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Summary: | We study the ratio
R
between the luminosity of the torus and that of the accretion disk, inferred from the relativistic model KERRBB for a sample of approximately 2000 luminosity-selected radio-quiet Type I active galactic nuclei from the Sloan Digital Sky Survey catalog. We find a mean ratio
R
≈ 0.8 and a considerable number of sources with
R
≳ 1. Our statistical analysis regarding the distribution of the observed ratios suggests that the largest values might be linked to strong relativistic effects due to a large black hole spin (
a
> 0.8), despite the radio-quiet nature of the sources. The mean value of
R
sets a constraint on the average torus aperture angle (in the range 30° <
θ
T
< 70°) and, for about one-third of the sources, the spin must be
a
> 0.7. Moreover, our results suggest that the strength of the disk radiation (i.e., the Eddington ratio) could shape the torus geometry and the relative luminosity ratio
R
. Given the importance of the involved uncertainties on this statistical investigation, an extensive analysis and discussion have been made to assess the robustness of our results. |
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ISSN: | 0004-6361 1432-0746 |
DOI: | 10.1051/0004-6361/202141602 |