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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

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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 

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