The nearby magnetic cool DZ white dwarf PM J08186-3110
Abstract
We present an analysis of photometric, spectroscopic and spectropolarimetric data of the nearby, cool, magnetic DZ white dwarf PM J08186-3110. High dispersion spectra show the presence of Zeeman splitted spectral lines due to the presence of a surface average magnetic field of 92 kG. The strong magnesium and calcium lines show extended wings shaped by interactions with neutral helium in a dense, cool helium-rich atmosphere. We found that the abundance of heavy elements varied between spectra taken ten years apart but we could not establish a time-scale for these variations; such variations may be linked to surface abundance variations in the magnetized atmosphere. Finally, we show that volume limited samples reveal that about 40% of DZ white dwarfs with effective temperatures below 7000 K are magnetic.
Keywords
Cite
@article{arxiv.2010.15319,
title = {The nearby magnetic cool DZ white dwarf PM J08186-3110},
author = {Adela Kawka and Stéphane Vennes and Nicole F. Allard and T. Leininger and F. X. Gadéa},
journal= {arXiv preprint arXiv:2010.15319},
year = {2020}
}
Comments
Accepted for publication in MNRAS