The origin of hot white dwarf circumstellar features The origin of hot DA circumstellar features
The origin of hot white dwarf circumstellar features The origin of hot DA circumstellar features
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热白矮星星周特征的起源 热DA星周特征的起源
DOI：
10.1111/j.1365-2966.2012.20964.x
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发表时间：
2012
影响因子：
4.8
通讯作者：
Dickinson N
中科院分区：
文献类型：
--
作者：
Dickinson N
我们分析了23个热DAs的样本，以更好地理解先前工作中报道的星周特征的来源。在八颗恒星上再次对星周物质进行了明确的探测。其中三颗白矮星的星周物质的速度与星际介质（ISM）沿着恒星视线的径向速度一致，这表明这些物体可能正在电离它们所在位置的ISM。在另外三种情况下，星周速度接近ISM的速度，这表明这些物体正在电离ISM或蒸发的星子/物质在星周圆盘上。wd1614−084的星周速度远低于ISM的速度，这表明未被探测到的ISM成分或星周物质发生了电离。在WD 0232+035上看到的物质可以归因于从它的M矮星伴星上丢失的物质的光电离。测量到的星周物质的柱密度位于热DA Strömgren球体中预测存在的电离ISM柱密度范围内。
We have analysed a sample of 23 hot DAs to better understand the source of the circumstellar features reported in previous work. Unambiguous detections of circumstellar material are again made at eight stars. The velocities of the circumstellar material at three of the white dwarfs are coincident with the radial velocities of interstellar medium (ISM) along the sight-line to the stars, suggesting that the objects may be ionizing the ISM in their locality. In three further cases, the circumstellar velocities are close to the ISM velocities, indicating that these objects are ionizing either the ISM or evaporated planetesimals/material in a circumstellar disc. The circumstellar velocity at WD 1614−084 lies far from the ISM velocities, indicating the ionization of either an undetected ISM component or circumstellar material. The material seen at WD 0232+035 can be attributed to the photoionization of material lost from its M dwarf companion. The measured column densities of the circumstellar material lie within the ionized ISM column density ranges predicted to exist in hot DA Strömgren spheres.