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Physical Sciences and Mathematics Commons™
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Full-Text Articles in Physical Sciences and Mathematics
The Mystery Of The Missing Boundary Layer, Gary J. Ferland, S. S. Langer, J. Macdonald, G. H. Pepper, G. Shaviv, J. W. Truran
The Mystery Of The Missing Boundary Layer, Gary J. Ferland, S. S. Langer, J. Macdonald, G. H. Pepper, G. Shaviv, J. W. Truran
Physics and Astronomy Faculty Publications
The question of the nature of the ultraviolet and X-ray radiation field of cataclysmic binaries is addressed. The spectrum and luminosity of this radiation are important in determining the mass transfer rate and energy budget of the system and in studies of the ejecta surrounding novae. In many systems, the soft X-ray luminosity is ~ 102-104 times weaker than predicted by simple accretion models. We discuss several possible solutions to this discrepancy. The most likely are either that the optical luminosity of a typical old nova is produced partly by reprocessed ultraviolet light from the white dwarf, …
Broad Line Region Clouds And The Absorbing Material In Ngc 4151, Gary J. Ferland, R. F. Mushotzky
Broad Line Region Clouds And The Absorbing Material In Ngc 4151, Gary J. Ferland, R. F. Mushotzky
Physics and Astronomy Faculty Publications
The constraints imposed by X-ray, ultraviolet, and optical observations on the absorbing material in the Seyfert 1.5 galaxy NGC 4151 are discussed. These observations are compared to the predictions of photoionization models of both broad line region clouds, which Holt et al. identify as the source of the extinction, and to models of the narrow line region gas. The weakness of both C III] 1909 and the broad component of Hα relative to C IV 1549, together with the absence of an absorption Balmer jump, indicate that the ionization parameter for the broad line region is a factor …