Accretion of grains and element abundances in cool, helium-rich white dwarfs

Astronomy and Astrophysics – Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

54

Abundance, B Stars, Stellar Mass Accretion, Stellar Models, Stellar Temperature, White Dwarf Stars, Helium, Silicates, Stellar Magnetic Fields, Stellar Rotation, Stellar Spectra

Scientific paper

The problem posed by the occasional presence of metal features in the spectra of cool, helium-rich white dwarfs within the framework of the accretion-diffusion picture of Vauclair, Vauclair, and Greenstein (1979) is considered. A model where metals from the interstellar medium are accreted in the form of grains by a slowly rotating, weakly magnetic white dwarf, and where the propeller mechanism of Illarionov and Sunyaev (1975) provides the screening mechanism required to prevent the accretion of interstellar hydrogen, is explored. The rate of rotation and surface magnetic field strength required in this model appears consistent with the sparse upper limits available for white dwarfs. For typical silicate grains, the propeller mechanism is found to be operative only for effective temperatures between about 8000 and about 15,000 K. This result is in qualitative agreement with the observed concentration of cool, helium-rich white dwarfs with metal features in that effective temperature range.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Accretion of grains and element abundances in cool, helium-rich white dwarfs does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Accretion of grains and element abundances in cool, helium-rich white dwarfs, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Accretion of grains and element abundances in cool, helium-rich white dwarfs will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1257103

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.