Because white dwarfs are the most common end state of stellar evolution, determining their internal structure will yield many clues about the final stages of stellar evolution and the physics of matter under extreme conditions. We present the results of our parametric survey of evolutionary models of composi-tionally stratified white dwarfs with hydrogen surface layers (DA white dwarfs) and provide a comprehensive set of theoretical g-mode pulsation periods for comparison to observations of pulsating DA white dwarfs. This survey complements the previous survey of helium atmosphere (DB) white dwarf periods of Bradley, Winget, & Wood. We show how to use the periods of low-overtone and/or trapped modes to constrain the internal structure of pulsating DA white dwarfs by utilizing their sensitivity to the total stellar mass and the location of the hydrogen/helium transition zone. We use G117-B15A as an example to demonstrate the potential of our models for asteroseismology; we suggest that G117-B15A has a mass of 0.55 Solar mass and a hydrogen layer mass of ≈ 1.5 x 10~(-4)M_*.
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机译：由于白矮星是恒星演化的最常见最终状态，因此确定它们的内部结构将为恒星演化的最终阶段和极端条件下物质的物理学提供许多线索。我们介绍了具有氢表面层的复合分层白矮星（DA白矮星）的演化模型的参数调查结果，并提供了一套完整的理论g模式脉动周期，用于与脉动DA白矮星的观测结果进行比较。该调查补充了先前对Bradley，Winget和Wood的氦气（DB）白矮期的调查。我们展示了如何利用低泛音和/或陷波模式的周期，通过利用脉动DA白矮星对总恒星质量的敏感性和氢/氦过渡区的位置来约束其内部结构。我们以G117-B15A为例，说明我们的模型在地震学方面的潜力。我们建议G117-B15A的质量为0.55太阳质量，氢层质量为≈1.5 x 10〜（-4）M_ *。
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