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Far-ultraviolet and optical spectrophotometry of X-ray selected Seyfert galaxiesFive X-ray selected Seyfert galaxies were examined via near-simultaneous far-ultraviolet and optical spectrophotometry in an effort to test models for excitation of emission lines by X-ray and ultraviolet continuum photoionization. The observed Ly-alpha/H-beta ratio in the present sample averages 22, with an increase found toward the high-velocity wings of the H lines in the spectrum of at least one of the Seyfert I nuclei. It is suggested that Seyfert galaxies with the most high-velocity gas exhibit the highest Ly-alpha/H-beta ratios at all velocities in the line profiles, and that sometimes this ratio may be highest for the highest velocity material in the broad-line clouds. Since broad-lined objects are least affected by Ly-alpha trapping effects, they have Ly-alpha/H-beta ratios much closer to those predicted by early photoionization calculations.
Document ID
19860055328
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Clarke, J. T.
(NASA Marshall Space Flight Center Huntsville, AL; California, University, Berkeley, United States)
Bowyer, S.
(California, University Berkeley, United States)
Grewing, M.
(Tuebingen, Universitaet Germany)
Date Acquired
August 12, 2013
Publication Date
June 1, 1986
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 305
ISSN: 0004-637X
Subject Category
Astrophysics
Accession Number
86A40066
Funding Number(s)
CONTRACT_GRANT: NAG5-69
Distribution Limits
Public
Copyright
Other

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