Broad emission line regions in active galactic nuclei: The link with the accretion power

Authors
Citation
F. Nicastro, Broad emission line regions in active galactic nuclei: The link with the accretion power, ASTROPHYS J, 530(2), 2000, pp. L65-L68
Citations number
20
Categorie Soggetti
Space Sciences
Journal title
ASTROPHYSICAL JOURNAL
ISSN journal
0004637X → ACNP
Volume
530
Issue
2
Year of publication
2000
Part
2
Pages
L65 - L68
Database
ISI
SICI code
0004-637X(20000220)530:2<L65:BELRIA>2.0.ZU;2-Z
Abstract
We present a model that relates the width of the broad emission lines of ac tive galactic nuclei (AGNs) to the Keplerian velocity of an accretion disk at a critical distance from the central black hole. This critical distance falls in a region bounded on the inward side by the transition radius betwe en the radiation pressure- and the gas pressure-dominated region of the acc retion disk and on the outward side by the maximum radius below which a sta bilizing, radially accreting and vertically outflowing corona exists. We sh ow that in the framework of this picture, the observed range of H beta FWHM s from broad-line to narrow-line type 1 AGNs is well reproduced as a functi on of the accretion rate. This interval of velocities is the only permitted range and goes from similar to 20,000 km s(-1) for sub-Eddington accretion rates to similar to 1000 km s(-1) fur Eddington accretion rates.