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Equilibrium Abundances of Heavy Elements Supported by Radiative Levitation in the Atmospheres of Hot DA White Dwarfs

Published online by Cambridge University Press:  12 April 2016

P. Chayer ,
S. Vennes ,
A.K. Pradhan ,
P. Thejll ,
A. Beauchamp ,
G. Fontaine  and
F. Wesemael
P. Chayer
Affiliation:
Center for EUV Astrophysics, 2150 Kittredge St., University of California at Berkeley, Berkeley, CA 94720-5030, USA
S. Vennes
Affiliation:
Center for EUV Astrophysics, 2150 Kittredge St., University of California at Berkeley, Berkeley, CA 94720-5030, USA
A.K. Pradhan
Affiliation:
Department of Astronomy, Ohio State University, Columbus, OH 43210-1106, USA
P. Thejll
Affiliation:
Niels Bohr Institute, Blegdamsvej 17, DK-2100, København Ø, Denmark
A. Beauchamp
Affiliation:
Departement de Physique, Université de Montréal, C.P. 6128, Succ. Centre-Ville, Montréal, Québec, Canada, H3C 3J7
G. Fontaine
Affiliation:
Departement de Physique, Université de Montréal, C.P. 6128, Succ. Centre-Ville, Montréal, Québec, Canada, H3C 3J7
F. Wesemael
Affiliation:
Departement de Physique, Université de Montréal, C.P. 6128, Succ. Centre-Ville, Montréal, Québec, Canada, H3C 3J7

Abstract

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We present revised estimates of the equilibrium abundances of heavy elements supported by radiative levitation in the atmospheres of hot DA white dwarfs. We emphasize, in particular, the role of trace pollutants that may be present in the background plasma, an effect which has been heretofore neglected. We take advantage of the availability of a table of detailed monochromatic opacities calculated for a plasma made of H containing small amounts of C, N, O, and Fe to illustrate how the equilibrium abundances of levitating elements react to the flux redistribution caused by the addition of these small traces of opaque material. We also consider two other improvements: a more sophisticated treatment of the momentum redistribution process and ion experiences following a photoexcitation, and use of an upgraded value for the line profile width associated with pressure broadening.

Type
IV. White Dwarf Structure/Evolution
Information
International Astronomical Union Colloquium , Volume 152: Astrophysics in the Extreme Ultraviolet , 1996 , pp. 211 - 215
Copyright
Copyright © Kluwer 1996

References

Bergeron, P., Wesemael, F., Michaud, G., & Fontaine, G. 1988, ApJ, 332, 964 CrossRefGoogle Scholar
Chayer, P., & Vennes, S. 1995, in preparationGoogle Scholar
Chayer, P., Fontaine, G., & Wesemael, F. 1995, ApJ, in pressGoogle Scholar
Chayer, P., LeBlanc, F., Fontaine, G., Wesemael, F., Michaud, G., & Vennes, S. 1994, ApJ, 436, L161 Google Scholar
Gonzalez, J.-F., LeBlanc, F., Artru, M.-C, Michaud, G. 1995, A&A, in pressGoogle Scholar
Vennes, S., Pradhan, A.K., Thejll, P. 1995, in preparationGoogle Scholar
Vennes, S., Chayer, P., Thorstensen, J.R., Bowyer, S., & Shipman, H.L. 1992, ApJ, 392, L27 Google Scholar
Werner, K., & Dreizler, S. 1994, A&A, 286, L31 Google Scholar
Wesemael, F., Henry, R.B.C., & Shipman, H.L. 1984, ApJ, 287, 868 Google Scholar