论文标题
脉动极低的质量白矮人SDSS J111215.82+111745.0：具有$ p $ - 模式脉动的模型与观测值一致
Asteroseismology of the pulsating extremely low-mass white dwarf SDSS J111215.82+111745.0: a model with $p$-mode pulsations consistent with the observations
论文作者
论文摘要
SDSS J111215.82+111745.0是发现的第二个脉动极低的白色矮人。在该恒星上检测到了两种短期脉动，即107.56和134.275 s，这将是在白矮人上观察到的第一个观察到的压力模式（$ p $ - 模式）。尽管两个潜在的$ p $ - modes尚未确认，但它们使SDSS J111215.82+111745.0成为一个有趣的对象。在这项工作中，我们分析了在SDSS J111215.82+111745.0上观察到的七个时期的整个集合。我们采用三个独立的周期间距测试，以揭示大约93.4 s的平均周期间距为$ \ ell = 1 $ $ g $ -modes，这给了$ \ ell = 1 $识别提供了更多的信心。然后，我们为该恒星执行性化症建模，其中H化学轮廓被视为变量。恒星参数$ m = 0.1650 \ pm0.0137 $ $ $ m_ \ odot $和$ t_ \ mathrm {eff} = 9750 \ pm560 $ k从最佳拟合模型确定，也定义了H/HH/HH/HE化学配置文件。这两个可疑的$ p $ modes在最佳拟合模型中也很好地表示，并且恒星参数和脉动频率都与从光谱学得出的值非常吻合。
SDSS J111215.82+111745.0 is the second pulsating extremely low-mass white dwarf discovered. Two short-period pulsations, 107.56 and 134.275 s, were detected on this star, which would be the first observed pressure mode ($p$-mode) pulsations observed on a white dwarf. While the two potential $p$-modes have yet to be confirmed, they make SDSS J111215.82+111745.0 an interesting object. In this work, we analyzed the whole set of seven periods observed on SDSS J111215.82+111745.0. We adopt three independent period-spacing tests to reveal a roughly 93.4 s mean period spacing of $\ell=1$ $g$-modes, which gives added credence to the $\ell=1$ identifications. Then we perform asteroseismic modeling for this star, in which the H chemical profile is taken as a variable. The stellar parameters $M=0.1650\pm0.0137$ $M_\odot$ and $T_\mathrm{eff}=9750\pm560$ K are determined from the best-fit model and the H/He chemical profiles are also defined. The two suspected $p$-modes are also well represented in the best-fit model, and both the stellar parameters and the pulsation frequencies are in good agreement with the values derived from spectroscopy.
