Evidence of enhanced magnetism in cool, polluted white dwarfs

Adela Kawka; Stéphane Vennes; Lilia Ferrario; Ernst Paunzen

doi:10.1093/mnras/sty3048

Evidence of enhanced magnetism in cool, polluted white dwarfs

Adela Kawka^*, Stéphane Vennes, Lilia Ferrario, Ernst Paunzen

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

33 Citations (Scopus)

Abstract

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 (≈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.

Original language	English
Pages (from-to)	5201-5210
Number of pages	10
Journal	Monthly Notices of the Royal Astronomical Society
Volume	482
Issue number	4
DOIs	https://doi.org/10.1093/mnras/sty3048
Publication status	Published - 1 Feb 2019

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abstract = "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 (≈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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T1 - Evidence of enhanced magnetism in cool, polluted white dwarfs

AU - Kawka, Adela

AU - Vennes, Stéphane

AU - Ferrario, Lilia

AU - Paunzen, Ernst

PY - 2019/2/1

Y1 - 2019/2/1

N2 - 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 (≈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.

AB - 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 (≈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.

KW - Stars: abundances

KW - Stars: individual: NLTT 7547

KW - Stars: magnetic field

KW - White dwarfs

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DO - 10.1093/mnras/sty3048

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EP - 5210

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

IS - 4

ER -

Evidence of enhanced magnetism in cool, polluted white dwarfs

Abstract

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