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ON THE OBSERVED DISTRIBUTIONS OF BLACK HOLE MASSES AND EDDINGTON RATIOS FROM RADIATION PRESSURE CORRECTED VIRIAL INDICATORS

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posted on 2023-06-08, 08:10 authored by Alessandro Marconi, David J Axon, Roberto Maiolino, Tohru Nagao, Paola Pietrini, Guido Risaliti, Andrew Robinson, Guidetta Torricelli
The application of the virial theorem to the broad-line region (BLR) of active galactic nuclei (AGNs) allows black hole (BH) mass estimates for large samples of objects at all redshifts. In a recent paper, we showed that ionizing radiation pressure onto BLR clouds affects virial BH mass estimates and we provided empirically calibrated corrections. More recently, a new test of the importance of radiation forces has been proposed: the M-BH-sigma relation has been used to estimate M-BH for a sample of type-2 AGNs and virial relations (with and without radiation pressure) for a sample of type-1 AGNs extracted from the same parent population. The observed L/L-Edd distribution based on virial BH masses is in good agreement with that based on M-BH-sigma only if radiation pressure effects are negligible, otherwise significant discrepancies are observed. In this Letter, we investigate the effects of intrinsic dispersions associated with the virial relations providing M-BH, and we show that they explain the discrepancies between the observed L/L-Edd distributions of type-1 and type-2 AGNs. These discrepancies in the L/L-Edd distributions are present regardless of the general importance of radiation forces, which must be negligible only for a small fraction of sources with large L/L-Edd. Average radiation pressure corrections should then be applied in virial M-BH estimators until their dependence on observed source physical properties has been fully calibrated. Finally, the comparison between M-BH and L/L-Edd distributions derived from sigma-based and virial estimators can constrain the variance of BLR physical properties in AGNs.

History

Publication status

  • Published

File Version

  • Published version

Journal

Astrophysical Journal Letters

ISSN

2041-8205

Issue

2

Volume

698

Page range

L103-L107

Department affiliated with

  • Physics and Astronomy Publications

Full text available

  • Yes

Peer reviewed?

  • Yes

Legacy Posted Date

2012-02-06

First Open Access (FOA) Date

2016-03-22

First Compliant Deposit (FCD) Date

2016-11-17

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