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Radiation-pressure-supported obscuring tori around active galactic nucleiRadiation pressure acting on dust grains can support the vertical thickness of the obscuring tori believed to exist in active galactic nuclei. Using the results of 2D radiation transfer calculations, we evaluate the radiation force acting on these tori. We find that on the inner edge of the torus the radiation force is about 350 l(E) times the gravitational force of the nucleus, where l(E) is the Eddington ratio. Beyond a few torus heights from the inner edge, the radiation force is negligible with respect to gravity. However, between these two extremes lies a region of considerable size where the ratio of radiation force to gravity is nearly constant and can be of order unity for l(E) about 0.1. If the distribution of material within the torus is sufficiently lumpy, there is a significant time-varying component to the radiation force. This drives the random motions of the constituent clouds, thickening the torus at lower values of l(E).
Document ID
19930030033
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Pier, Edward A.
(NASA Headquarters Washington, DC United States)
Krolik, Julian H.
(Johns Hopkins Univ. Baltimore, MD, United States)
Date Acquired
August 15, 2013
Publication Date
November 1, 1992
Publication Information
Publication: Astrophysical Journal, Part 2 - Letters
Volume: 399
Issue: 1
ISSN: 0004-637X
Subject Category
Astrophysics
Accession Number
93A14030
Funding Number(s)
CONTRACT_GRANT: NAGW-2803
Distribution Limits
Public
Copyright
Other

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