Evidence of enhanced magnetism in cool, polluted white dwarfs

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KAWKA Adela VENNES Stephane FERRARIO Lilia PAUNZEN Ernst

Druh Článek v odborném periodiku
Časopis / Zdroj Monthly Notices of the Royal Astronomical Society
Fakulta / Pracoviště MU

Přírodovědecká fakulta

Citace
Doi http://dx.doi.org/10.1093/mnras/sty3048
Klíčová slova stars: abundances; stars: individual: NLTT 7547; stars: magnetic field; white dwarfs
Popis We report the discovery of a new, polluted, magnetic white dwarf in the Luyten survey of high-proper motion stars. High-dispersion spectra of NLTT 7547 reveal a complex heavy element line spectrum in a cool (approximate to 5200 K) hydrogen-dominated atmosphere showing the effect of a surface averaged field of 163 kG, consistent with a 240 kG centred dipole, although the actual field structure remains uncertain. The abundance pattern shows the effect of accreted material with a distinct magnesium-rich flavour. Combined with earlier identifications, this discovery supports a correlation between the incidence of magnetism in cool white dwarfs and their contamination by heavy elements.
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