The ubiquity of carbon dredge-up in hydrogen-deficient white dwarfs as revealed by GALEX
The ubiquity of carbon dredge-up in hydrogen-deficient white dwarfs as revealed by GALEX
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GALEX 揭示了缺氢白矮星中碳清除的普遍性
DOI：
10.1093/mnrasl/slad105
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发表时间：
2023
影响因子：
--
通讯作者：
Tremblay, Pier-Emmanuel
中科院分区：
文献类型：
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作者：
Blouin, Simon;Kilic, Mukremin;Bédard, Antoine;Tremblay, Pier-Emmanuel
长期以来，人们一直用从缺氢白矮星内部对流吸收碳来解释冷DQ星(K)光谱中碳吸收特征的存在。据推测，这种输运过程不仅限于DQ白矮星，而且在相同温度范围内的非DQ缺氢白矮星中也会发生，尽管效率较低。这个非dq星群主要由DC白矮星组成，它们的光谱没有特征。然而，到目前为止，还没有发现直流恒星中普遍存在碳污染的直接观测证据。在这篇论文中，我们分析了来自星系演化探测器的数据，揭示了大多数DC白矮星在k温度范围内的紫外碳谱线的光度特征。我们的研究结果表明，绝大多数缺乏氢的白矮星在它们的进化过程中都会经历碳的吸收。
The convective dredge-up of carbon from the interiors of hydrogen-deficient white dwarfs has long been invoked to explain the presence of carbon absorption features in the spectra of cool DQ stars (K). It has been hypothesized that this transport process is not limited to DQ white dwarfs and also operates, albeit less efficiently, in non-DQ hydrogen-deficient white dwarfs within the same temperature range. This non-DQ population is predominantly composed of DC white dwarfs, which exhibit featureless optical spectra. However, no direct observational evidence of ubiquitous carbon pollution in DC stars has thus far been uncovered. In this Letter, we analyse data from theGalaxy Evolution Explorerto reveal the photometric signature of ultraviolet carbon lines in most DC white dwarfs in theK temperature range. Our results show that the vast majority of hydrogen-deficient white dwarfs experience carbon dredge-up at some point in their evolution.