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The origin of N III lambda 990 and C III lambda 977 emission in AGN narrow-line region gasWe discuss implications of Hopkins Ultraviolet Telescope (HUT) detections of C III lambda 977 and N III lambda 990 emission from the narrow-line region of the Seyfert 2 galaxy NGC 1068. In their discovery paper Kriss et al. showed that the unexpectedly great strength of these lines implies that the emitting gas must be shock-heated if the lines are collisionally excited. Here we investigate other processes which excite these lines in photoionization equilibrium. Recombination, mainly dielectronic, and continuum fluorescence are strong contributors to the line. The resulting intensities are sensitive to the velocity field of the emitting gas and require that the turbulence be of the same order of magnitude as the observed line width. We propose optical observations that will decide whether the gas is collisionally or radiatively heated.
Document ID
19950037957
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Ferguson, J. W.
(Univ. of Kentucky, Lexington, KY United States)
Ferland, G. J.
(Univ. of Kentucky, Lexington, KY United States)
Pradhan, A. K.
(Ohio State Univ. Columbus, OH, United States)
Date Acquired
August 16, 2013
Publication Date
January 10, 1995
Publication Information
Publication: Astrophysical Journal, Part 2 - Letters
Volume: 438
Issue: 2
ISSN: 0004-637X
Subject Category
Astrophysics
Accession Number
95A69556
Funding Number(s)
CONTRACT_GRANT: NSF PHY-91-115057
CONTRACT_GRANT: NSF AST-93-19034
CONTRACT_GRANT: NAGW-3315
Distribution Limits
Public
Copyright
Other

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