Precise parameters for both white dwarfs in the eclipsing binary CSS 41177
Precise parameters for both white dwarfs in the eclipsing binary CSS 41177
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DOI：
10.1093/mnras/stt2453
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发表时间：
2014-01
影响因子：
4.8
通讯作者：
M. Bours;T. Marsh;S. Parsons;C. Copperwheat;V. Dhillon;S. Littlefair;B. Gänsicke;A. Gianninas;P. Tremblay
中科院分区：
文献类型：
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作者：
M. Bours;T. Marsh;S. Parsons;C. Copperwheat;V. Dhillon;S. Littlefair;B. Gänsicke;A. Gianninas;P. Tremblay
我们目前的ULTRACAM测光和X-射手光谱的食双白色矮星二进制CSS 41177，唯一这样的系统，也是一个双线光谱二进制。光变曲线和径向速度的组合模型产生了两颗白色矮星的质量和半径，而不需要假设质量-半径关系。我们发现主白色矮星的质量为M1 = 0.38 ± 0.02 M，半径为R1 = 0.0222 ± 0.0004 R。次级白色矮星的质量和半径分别为M2 = 0.32 ± 0.01 M和R2 = 0.0207 ± 0.0004 R，其温度和表面重力（T2 = 11678 ± 313 K，log（g2）= 7.32 ± 0.02）接近于白色矮星不稳定带。然而，我们没有发现相对振幅约为0.5%的脉动的证据。质量和半径都与氦白色矮星模型一致，其薄氢包层小于10−4 M*。这两颗恒星将在1.14 ± 0.07 Gyr合并，这是由于引力波发射造成的角动量损失。
We present ULTRACAM photometry and X-Shooter spectroscopy of the eclipsing double white dwarf binary CSS 41177, the only such system that is also a double-lined spectroscopic binary. Combined modelling of the light curves and radial velocities yield masses and radii for both white dwarfs without the need to assume mass–radius relations. We find that the primary white dwarf has a mass of M1 = 0.38 ± 0.02 M⊙ and a radius of R1 = 0.0222 ± 0.0004 R⊙. The secondary white dwarf's mass and radius are M2 = 0.32 ± 0.01 M⊙ and R2 = 0.0207 ± 0.0004 R⊙, and its temperature and surface gravity (T2 = 11678 ± 313 K, log(g2) = 7.32 ± 0.02) put it close to the white dwarf instability strip. However, we find no evidence for pulsations to roughly 0.5 per cent relative amplitude. Both masses and radii are consistent with helium white dwarf models with thin hydrogen envelopes of ≤10−4 M*. The two stars will merge in 1.14 ± 0.07 Gyr due to angular momentum loss via gravitational wave emission.