论文标题
DQ星中缺少金属：一个简单的解释
Missing metals in DQ stars: A simple explanation
论文作者
论文摘要
经典的DQ恒星是白色矮人，其大气包含可检测到的碳痕迹，这是通过对流挖掘过程中提出的。有趣的是，与其他白色矮谱类不同，DQ星实际上永远不会显示出比碳更重的元素的外部污染迹象。在这封信中，我们通过表明DQ恒星中缺乏可检测到的外部污染来解决这个长期存在的问题，这自然是由于金属积聚对白矮人大气结构的影响而自然解释的。增压元素的DQ星看到其大气密度的降低，从而导致分子丰度急剧下降，并强烈抑制C $ _2 $ _2 $ swan波段。我们表明，从行星材料中积聚重元素的典型DQ星通常会直接转化为DZ恒星。
Classical DQ stars are white dwarfs whose atmospheres contain detectable traces of carbon brought up to the surface by a convective dredge-up process. Intriguingly, unlike other white dwarf spectral classes, DQ stars virtually never show signs of external pollution by elements heavier than carbon. In this Letter, we solve this long-standing problem by showing that the absence of detectable external pollution in DQ stars is naturally explained by the impact of metal accretion on the atmospheric structure of the white dwarf. A DQ star that accretes heavy elements sees its atmospheric density decrease, which leads to a sharp drop in the molecular carbon abundance and a strong suppression of the C$_2$ Swan bands. We show that a typical DQ star that accretes heavy elements from planetary material generally transforms directly into a DZ star.
