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Carbon and Hydrocarbon Molecules in Very Cool White Dwarfs

Published online by Cambridge University Press:  25 May 2016

Turgut Aslan  and
Irmela Bues
Turgut Aslan
Affiliation:
Dr. Remeis Sternwarte, Astronomisches Institut der Universität Erlangen-Nürnberg, 96049 Bamberg, Germany
Irmela Bues
Affiliation:
Dr. Remeis Sternwarte, Astronomisches Institut der Universität Erlangen-Nürnberg, 96049 Bamberg, Germany

Abstract

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We report on our investigations in progress on the importance of polyatomic molecules – especially of carbon and hydrocarbon – in the atmospheres of very cool helium-rich white dwarfs. For two sets of abundance ratios, model atmospheres with Teff = 5000 K, log g = 8.0 have been computed and the dependence of C3, C2H and C2H2 on abundance variations of H/He, C/He, O/He and N/He has been calculated in detail, with the absorption of carbon molecules included quantitatively. We discuss the possibility that C2H features can explain the observed IR flux deficiency for LHS 1126 at 1.6 μm and 2.0–2.3 μm.

Type
Session II — Models and Abundance Determinations
Information
Symposium - International Astronomical Union , Volume 177: The Carbon Star Phenomenon , 2000 , pp. 97 - 102
Copyright
Copyright © Kluwer 2000 

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