Institut für Astronomie und Astrophysik Abteilung Astronomie Sand 1, D-72076 Tübingen, Germany
Hinweis: Einige Seiten auf astro.uni-tuebingen.de können veraltet sein und werden nicht mehr aktualisiert. Note: Some webpages at astro.uni-tuebingen.de may be outdated and will no longer be updated.

Preprint 09/08

Spectral modeling of gaseous metal disks around DAZ white dwarfs

K. Werner, T. Nagel, T. Rauch

Institut für Astronomie und Astrophysik, Universität Tübingen

To be published in: Proceedings, 16th European White Dwarf Workshop, Barcelona, 2008

Abstract. We report on our attempt for the first non-LTE modeling of gaseous metal disks around single DAZ white dwarfs recently discovered by Gaensicke et al. and thought to originate from a disrupted asteroid. We assume a Keplerian rotating viscous disk ring composed of calcium and hydrogen and compute the detailed vertical structure and emergent spectrum. We find that the observed infrared CaII emission triplet can be modeled with a hydrogen-deficient gas ring located at R=1.2 R_sun, inside of the tidal disruption radius, with T_eff about 6000 K and a low surface mass density of about 0.3 g/cm². A disk having this density and reaching from the central white dwarf out to R=1.2 R_sun would have a total mass of 7x10²¹ g, corresponding to an asteroid with about 160 km diameter.
 

Preprint (194 kb PDF file including figures)
Astrophysics (astro-ph): 0809.5200

[Home Page] [Preprints 2008] [Quick Reference] [Feedback]

| Impressum Last modified 30 Sep 2008