The polluted atmospheres of cool white dwarfs and the magnetic field connection

0429445 - ASÚ 2015 RIV GB eng J - Článek v odborném periodiku
Kawka, Adela - Vennes, Stephane
The polluted atmospheres of cool white dwarfs and the magnetic field connection.
Monthly Notices of the Royal Astronomical Society. Roč. 439, č. 1 (2014), L90-L94. ISSN 0035-8711. E-ISSN 1365-2966
Grant CEP: GA ČR GAP209/12/0217; GA ČR GA13-14581S
Institucionální podpora: RVO:67985815
Klíčová slova: white dwarfs * stars: abundances * stars: atmospheres
Kód oboru RIV: BN - Astronomie a nebeská mechanika, astrofyzika
Impakt faktor: 5.107, rok: 2014

We present an analysis of X-Shooter spectra of the polluted hydrogen-rich white dwarfs (DAZ) NLTT 888 and NLTT 53908. The spectra of NLTT 53908 show strong, Zeeman-split calcium lines (Ca II H&K and Ca I lambda 4226) and the star appears to be a close relative of the polluted magnetic white dwarf (DAZH) NLTT 10480, while the spectra of NLTT 888 show narrow lines of calcium and iron. A comparison of the DAZ NLTT 888 and the DAZH NLTT 53908 with other class members illustrates the diversity of environment and formation circumstances surrounding these objects. In particular, we find that the incidence of magnetism in old, polluted white dwarfs significantly exceeds that found in the general white dwarf population which suggests a hypothetical link between a crowded planetary system and magnetic field generation.
Trvalý link: http://hdl.handle.net/11104/0234567