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Non-LTE effects on the strength of the Lyman edge in quasar accretion disksWe have calculated UV/EUV (300 A which is less than or equal to lambda which is less than or equal to 1500 A) continuous energy distributions of accretion disks in the centers of active galactic nuclei (AGNs) for disk luminosities in the range 0.1 L(sub Edd) less than or equal to L(sub acc) less than 1.0 L(sub Edd) and central masses ranging from 10(exp 8) solar mass to 10(exp 9) solar mass. The vertical gas pressure structure of the disk and the disk height are obtained analytically; the temperature stratification and the resulting continuum radiation fields are calculated numerically. We have included non-Local Thermodynamic Equilibrium (LTE) effects of both the ionization equilibrium and the level populations of hydrogen and helium. We show that these non-LTE effects reduce the strength of the Lyman edge when comapred to the LTE case. In non-LTE we find that the edge can be weakly in emission or absorption for disks seen face-on, depending on the disk parameters.
Document ID
19950038240
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Stoerzer, H.
(Universitat zu Koln Koln, Germany)
Hauschildt, P. H.
(Arizona State University Tempe, AZ, United States)
Allard, F.
(University of British Columbia Vancouver, BC, Canada)
Date Acquired
August 16, 2013
Publication Date
December 20, 1994
Publication Information
Publication: Astrophysical Journal, Part 2 - Letters
Volume: 437
Issue: 2
ISSN: 0004-637X
Subject Category
Astrophysics
Accession Number
95A69839
Funding Number(s)
CONTRACT_GRANT: DFG-SFB-301
Distribution Limits
Public
Copyright
Other

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