FUSE observations of hot white dwarfs
نویسندگان
چکیده
منابع مشابه
FUSE observations of hot white dwarfs
We have analyzed FUSE observations of six hot white dwarf stars: four DA white dwarfs with Teff >∼ 45 000 K, the DAO Feige 55 (Teff ≈ 55 000 K), and the DA CD−38◦ 10980 (Teff ≈ 24 000 K). Photospheric lines from Si IV, PV, and S VI can be observed in the majority of the five hotter objects. Feige 55 shows also several other heavier elements. The measured abundances agree only partly with the pr...
متن کاملFUSE Observations of the Hottest DA White Dwarfs
We report early FUSE observations of the very hot DA white dwarfs PG1342+444 and REJ0558−371. Detection of photospheric absorption lines allows us to estimate the abundances of C, O, Si, P, S and Fe, the first measurements reported for DA stars at such high temperatures. Values of T eff and log g determined for PG1342+444 from the Lyman line series disagree with the results of the standard Balm...
متن کاملSTIS observations of 5 hot DA white dwarfs
We present some early results from a study of five hot DA white dwarf stars, based on spectra obtained using STIS. All show multiple components in one or more of the strong resonance absorption lines typically associated with the stellar photosphere (e.g. C IV, Si IV, N V and O V). Possible relationships between the non-photospheric velocity components and the interstellar medium or local stell...
متن کاملIdentification of neon in FUSE and VLT spectra of extremely hot hydrogen - deficient ( pre - ) white dwarfs ⋆ ⋆ ⋆
One of the strongest absorption lines observed in far-ultraviolet FUSE spectra of many PG1159 stars remained unidentified up to now. We show that this line, located at 973.3Å, stems from Ne . We also present new optical high-resolution spectra of PG1159 stars, obtained with the ESO VLT, which cover the Ne 3644Å line and a newly identified Ne multiplet in the 3850–3910Å region. We com...
متن کاملFuse Spectroscopy of the Two Prototype White Dwarfs with Signatures of a Super-hot Wind
The O VIII phenomenon describes the occurrence of ultra-high ionization absorption lines of the CNO elements (e.g. O VIII, N VII, C VI, and even Ne X) in the optical spectra hot of DO WDs. This requires temperatures of almost 10 6 K. Since the first discovery of two such objects (Werner et al. 1995) we realized that 50% of all DO WDs are affected (Dreizler et al. 1995), hence it could be that a...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Astronomy & Astrophysics
سال: 2001
ISSN: 0004-6361,1432-0746
DOI: 10.1051/0004-6361:20010612