Hostname: page-component-84b7d79bbc-g7rbq Total loading time: 0 Render date: 2024-07-27T18:15:57.175Z Has data issue: false hasContentIssue false

Pressure Shifts of Metal Lines in Cool White Dwarfs

Published online by Cambridge University Press:  12 April 2016

Gordon L. Hammond*
Affiliation:
Astronomy Program,Department of MathematicsUniversity of South Florida,Tampa, FL 33620

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Model atmosphere techniques and an experimentally confirmed theory of collision broadening of CaII H and K by helium have been combined to shou that the difference in velocity shifts for the two lines is a sensitive diagnostic for the H/He abundance ratio in cool, metallic line uhite dwarfs.

Type
Research Article
Copyright
Copyright © Springer-Verlag 1989

References

Aannestad, P.A., and Sion, E.M. 1985, A. J., 90, 1832.CrossRefGoogle Scholar
Bell, R.A. 1970, M.N.R.A.S., 148, 25.CrossRefGoogle Scholar
Greenstein, J.L. 1977, Ap. J. 173, 377.CrossRefGoogle Scholar
Breenstein, J.L. 1984, Ap. J., 276, 607.Google Scholar
Hammond, S.L. 1974, Ph.D. Dissertation, University Maryland, College Park, MDGoogle Scholar
Hammond, G.L. 1975, Ap. J., 196, 291.CrossRefGoogle Scholar
Hammond, S.L. 1987, Bull. AAS, 19, 755.Google Scholar
Liebert, J. 1977, Apstr. Ap., 60, 101.Google Scholar
Liebert, J., Uehrse, R., and Green, R.F. 1987, Apstr. Ap., 175, 173.Google Scholar
Monteiro, T., Cooper, I., Dickinson, A., and Lewis, E. 1986, J. Phys. B. 19, 4087 Google Scholar
Sion, E.M. 1988, private communication.Google Scholar
Wagner, R., Sion, E.M., Liebert, J., and Starrfield, S. 1988, Ap. J., 328, 213.CrossRefGoogle Scholar
Zeidler-K.T., E.-M., Weidemann, V., and Koester, D. 1986, Apstr. Ap. 155, 356.Google Scholar