Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-25T17:12:06.637Z Has data issue: false hasContentIssue false
  • English
  • Français

16. The Line Spectra of White Dwarfs

Published online by Cambridge University Press:  14 August 2015

P. A. Strittmatter  and
D. T. Wickramasinghe
P. A. Strittmatter
Affiliation:
Institute of Theoretical Astronomy, Cambridge, U.K.
D. T. Wickramasinghe
Affiliation:
Institute of Theoretical Astronomy, Cambridge, U.K.

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 atmospheres with temperatures in the range 10000 ≤ Teff ≤ 25000 K and with gravities 6 ≤ log(g) ≤ 9 have been constructed for various helium abundances with a view to understanding the spectra of the hotter white dwarfs. It is shown that the DB stars are confined to the temperature range 15000 ≤ Teff ≤ 18000 K in which convection also becomes important in the outer layers of helium rich stars. The DA stars seem to avoid this temperature range. The hydrogen and metal abundances in DB atmospheres are shown to be reduced by factors 105 and 103 respectively compared to solar values. Possible explanations of DB and DC spectra are discussed.

Type
Research Article
Information
Symposium - International Astronomical Union , Volume 42: White Dwarfs , 1971 , pp. 116 - 123
Copyright
Copyright © Reidel 1971 

References

Avrett, F. H. and Krook, M.: 1963, Astrophys. J. 137, 874.Google Scholar
Bondi, H. and Hoyle, F.: 1944, Monthly Notices Roy. Astron. Soc. 104, 273.CrossRefGoogle Scholar
Brechot-Sahal, S.: 1968, Z. Astrophys. 69, 74.Google Scholar
Eggen, O. J.: 1970, Astrophys. J. 159, 945.Google Scholar
Eggen, O. J. and Greenstein, J. L.: 1965, Astrophys. J. 141, 83.Google Scholar
Eggen, O. J. and Greenstein, J. L.: 1967, Astrophys. J. 150, 927.Google Scholar
Greenstein, J. L.: 1960, Stars and Stellar Systems 6 (ed. by Greenstein, J. L.), University of Chicago Press, Chicago, p. 676.Google Scholar
Greenstein, J. L.: 1969, Astrophys. J. 158, 281.Google Scholar
Griem, H.: 1968, Astrophys. J. 154, 1111.Google Scholar
Klemola, A. R.: 1961, Astrophys. J. 134, 130.Google Scholar
Mathews, T. A. and Sandage, A.: 1963, Astrophys. J. 138, 30.Google Scholar
Somerville, W. B.: 1965, Astrophys. J. 141, 811.Google Scholar
Strittmatter, P. A. and Wickramasinghe, D. T.: 1970, Monthly Notices Roy. Astron. Soc., in press (paper III).Google Scholar
Terashita, Y. and Matsushima, S.: 1969, Astrophys. J. 156, 183.Google Scholar
van Horn, H. M.: 1970, Astrophys. J. Letters 160, 53.Google Scholar
Vardya, M. S.: 1961, Astrophys. J. 133, 107.Google Scholar
Wickramasinghe, D. T. and Strittmatter, P. A.: 1969, Astron. Astrophys. 2, 242.Google Scholar
Wickramasinghe, D. T. and Strittmatter, P. A.: 1970, Monthly Notices Roy. Astron. Soc., 150, 435 (paper II).Google Scholar