Spectral analysis of hot DO white dwarf PG 1034+001
K. Werner1, S.Dreizler2, B. Wolff11Institut für Astronomie und Astrophysik der Universität, D-24098 Kiel, Germany
2Dr. Remeis Sternwarte, Universität Erlangen-Nürnberg, 96049-Bamberg, Germany
We present a non-LTE model atmosphere analysis of the hot DO white dwarf PG 1034+001. It is based on archival HST GHRS spectra, on new optical medium resolution spectra and pointed ROSAT PSPC observations.
The effective temperature is higher than previously thought (Teff=100000K, log g=7.5). We determined abundances of carbon, nitrogen, and oxygen which are roughly in agreement with earlier LTE results. We also determined the silicon abundance and, for the first time in a DO white dwarf, the abundance of iron on hand of newly identified Fe VI lines in the HST spectra. An upper abundance limit for nickel is derived. The results are discussed in the framework of diffusion theory.
We derive a stellar mass of 0.59Msun and propose that PG 1034+001 is a descendant from the hydrogen-deficient PG 1159 stars.
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