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Some implications of ultraviolet observations of quasars and active galaxiesThe problem of the order of magnitude discrepancy in the expected and observed ratios of the Lyman and Balmer lines in quasars and active galaxies is reviewed. Whereas early photoionization models for the emission line regions predicted F(L-alpha)/F(H-beta) not less than 40, the observations give values for this ratio in the range 3-8. Attempts at explaining the observations have involved dust, both external and internal to the emission line regions, and improved treatments of the collisional processes and radiative transfer effects in dense (Ne about 10 to the 10th/cu cm), optically thick clouds. None of the effects considered is, by itself, able to explain all the observations, and a combination of several of them is probably required.
Document ID
19800067478
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Davidsen, A. F.
Date Acquired
August 10, 2013
Publication Date
January 1, 1980
Subject Category
Astrophysics
Meeting Information
Meeting: Objects of high redshift
Location: Los Angeles, CA
Start Date: August 28, 1979
End Date: August 31, 1979
Accession Number
80A51648
Funding Number(s)
CONTRACT_GRANT: NGR-21-001-001
Distribution Limits
Public
Copyright
Other

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