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arXiv 0902.3640astro-ph.SR
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白矮星KUV 02196+2816的光谱分析:一个新的未分辨的DA + DB简并双星

Spectroscopic Analysis of the White Dwarf KUV 02196+2816: A New Unresolved DA+DB Degenerate Binary

M. -M. Limoges, P. Bergeron, Pierre Dufour

摘要:

本文对DBA(或DAB)白矮星KUV 02196+2816进行了光谱分析.所观察到的氢和氦线的配置文件被证明是不兼容的模型下计算的假设一个均匀的氢和氦的化学成分的光谱。相反,如果将KUV 02196+2816解释为由氢线DA星和氦线DB星组成的未解析双简并星,则可以实现与KUV 02196+2816的光谱的极好拟合。由最佳拟合得到的大气参数为:DA星的Teff= 27,170 K,log g=8.09; DB星的Teff= 36,340 K,log g=8.09,这意味着系统的总质量(M~1.4 Msol)非常接近于克拉塞卡极限。此外,DB星的有效温度位于所谓的DB间隙内,很少有明亮的DB星被发现。这一发现的DAB和DBA光谱类和双退化双星的演化的影响进行了讨论。

英文摘要:

A spectroscopic analysis of the DBA (or DAB) white dwarf KUV 02196+2816 is presented. The observed hydrogen and helium line profiles are shown to be incompatible with model spectra calculated under the assumption of a homogeneous hydrogen and helium chemical composition. In contrast, an excellent fit to the optical spectrum of KUV 02196+2816 can be achieved if the object is interpreted as an unresolved double degenerate composed of a hydrogen-line DA star and a helium-line DB star. The atmospheric parameters obtained from the best fit are Teff=27,170 K and log g=8.09 for the DA star, Teff=36,340 K and log g=8.09 for the DB star, which implies that the total mass of the system (M~1.4 Msol) is very close to the Chandrasekhar limit. Moreover, the effective temperature of the DB stars lies well within the so-called DB gap where very few bright DB stars are found. The implications of this discovery with respect to the DAB and DBA spectral classes and to the evolution of double degenerate binaries are discussed.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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