Heavy element abundances in DAO white dwarfs measured from FUSE data
نویسندگان
چکیده
منابع مشابه
Element abundances in cool white dwarfs I .
The standard explanation for the presence of photospheric metals in white dwarfs of spectral type DZ and related types is a combination of episodic accretion from the interstellar medium and diffusion of heavy elements downwards in the atmosphere on time scales of typically 106 years. Much of the empirical data on atmospheric parameters and element abundances available in the literature is base...
متن کاملElement abundances in cool white dwarfs
We present a small data base of homogeneously derived photospheric element abundances of DZ white dwarfs and related objects. Our previous investigations are supplemented with the analysis of ultraviolet spectra for nine white dwarfs. Of particular interest is the detection of Lα absorption in van Maanen 2 and a determination of the effective temperature of this star. The new value is about 100...
متن کاملA search for binarity using FUSE observations of DAO white dwarfs
We report on a search for evidence of binarity in Far-Ultraviolet Spectroscopic Explorer (FUSE) observations of DAO white dwarfs. Spectra recorded by FUSE are built up from a number of separate exposures. Observation of changes in the position of photospheric heavy element absorption lines between exposures, with respect to the stationary interstellar medium lines, would reveal radial velocity ...
متن کاملFUSE 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 کاملHeavy element abundance patterns in hot DA White Dwarfs
We present a series of systematic abundance measurements for 25 hot DA white dwarfs in the temperature range ~20000-110000K, based on far-UV spectroscopy with STIS/GHRS on HST, IUE and FUSE. Using our latest heavy element blanketed non-LTE stellar atmosphere calculations we have addressed the heavy element abundance patterns making completely objective measurements of abundance values and upper...
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: Monthly Notices of the Royal Astronomical Society
سال: 2005
ISSN: 0035-8711,1365-2966
DOI: 10.1111/j.1365-2966.2005.09428.x