The heavily polluted atmosphere of the DAZ white dwarf GALEX J193156.8+011745

作者：Vennes S^*; Kawka A; Nemeth P

来源：Monthly Notices of the Royal Astronomical Society, 2010, 404(1): L40-L44.

DOI：10.1111/j.1745-3933.2010.00830.x

• stars: abundance
• stars: individual: GALEX J193156.8+011745
• white dwarfs

We report on the discovery of a new heavily polluted white dwarf. The DAZ white dwarf GALEX J193156.8+011745 was identified in a joint Galaxy Evolution Explorer (GALEX)/GSC survey of ultraviolet-excess objects. Optical spectra obtained at ESO New Technology Telescope show strong absorption lines of magnesium and silicon, and a detailed abundance analysis based on Very Large Telescope-Kueyen UVES spectra reveal super-solar abundances of silicon and magnesium and near-solar abundances of oxygen, calcium and iron. The overall abundance pattern bears the signature of on-going accretion on to the white dwarf atmosphere. The infrared spectral energy distribution shows an excess in the H and K bands likely associated with the accretion source.

• 出版日期2010-5-1