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.

中文翻译：

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附近的磁冷 DZ 白矮星 PM J08186−3110

我们对附近的冷磁 DZ 白矮星 PM J08186-3110 的光度、光谱和光谱偏振数据进行了分析。高色散光谱显示，由于存在 92 kG 的表面平均磁场，因此存在塞曼分裂谱线。强烈的镁和钙线显示出在浓密、凉爽的富含氦气的大气中与中性氦相互作用形成的延伸翅膀。我们发现重元素的丰度在相隔十年的光谱之间有所不同，但我们无法确定这些变化的时间尺度；这种变化可能与磁化大气中的表面丰度变化有关。最后，我们展示了体积受限的样本表明，大约 40% 的有效温度低于 7000 K 的 DZ 白矮星是磁性的。