An interpretation of the spectral properties of hot hydrogen-rich white dwarfs with stratified H/He model atmospheres
An interpretation of the spectral properties of hot hydrogen-rich white dwarfs with stratified H/He model atmospheres
复制标题
分层 H/He 模型大气中热富氢白矮星光谱特性的解释
DOI：
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发表时间：
1992
期刊：
影响因子：
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通讯作者：
G. Fontaine
中科院分区：
文献类型：
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作者：
S. Vennes;G. Fontaine
计算了适用于解释热的富氢白矮星(WD)光谱性质的分层H/He模式大气网格。利用这些模型对Exosat和Einstein观测到的热DA WD样本进行了分析。在T(Ef)=35,000K或更低的六个天体中，有六个没有表现出极紫外光/软X射线通量不足，因此可以仅从纯氢大气的角度来理解。大多数比这个值更热的DA WD确实表现出通量不足，因此需要在它们的大气中存在一些吸收体。结果表明，Feige 24和G191 B2B的Exosat宽带测光不能用层结大气来解释。在这些情况下，重元素的吸收肯定是造成所需的极紫外线/软X射线不透明源的原因。然而，Exosat的数据与其余四个天体中存在分层大气的假设是一致的。
A grid of stratified H/He model atmospheres applicable to the interpretation of the spectral properties of hot H-rich white dwarfs (WDs) is computed. Samples of hot DA WDs observed with Exosat and Einstein are analyzed using the models. Six out of six objects with T(eff) = 35,000 K or less do not show a EUV/soft X-ray flux deficiency and therefore can be understood solely in terms of pure hydrogen atmospheres. A majority of DA WDs hotter than this value do show a flux deficiency and thus require the presence of some absorbers in their atmospheres. It is shown that the Exosat broadband photometry of Feige 24 and G191 B2B cannot be explained in terms of stratified atmospheres. Absorption by heavy elements is certainly responsible for the required EUV/soft X-ray opacity source in these cases. However, the Exosat data are consistent with the hypothesis of stratified atmospheres in the four remaining objects.