标题： 主序星和次巨星类太阳振荡器的结构核的线性性 显示英文标题

标题： Linearity of Structure Kernels in Main-sequence and Subgiant Solar-like Oscillators

摘要： 地震结构反演已被用于研究太阳内部数十年。 通过使用开普勒任务获得的高精度频率，现在可以使用结构反演来研究其他类似太阳的振荡器，包括主序星和次巨星。 次巨星特别有趣，因为它们表现出混合声波-浮力模式，这为探测恒星核心的更深层区域提供了机会。 本研究检查了为太阳和其他主序星的纯声学模式开发的结构反演技术是否仍适用于次巨星中观测到的混合模式。 我们构建了两个模型网格：一个是主序星的网格，另一个是早期次巨星的网格。 利用这些网格，我们检查了反演过程的两个不同部分。 首先，我们检查所谓的“核误差”，这些误差衡量模式敏感度函数恢复两个模型之间已知频率差异的能力。 其次，我们测试这些核误差如何影响反演推断已知结构差异的能力。 在主序星上，我们发现可以在我们考虑的所有质量范围和大频率间隔内获得可靠的结构反演结果。 然而，在次巨星分支上，混合模式的快速演化导致大的核误差，从而难以恢复已知的结构差异。 我们的测试表明，使用混合模式可靠地推断次巨星的结构需要改进当前的拟合方法并对结构反演技术进行修改。 显示英文摘要

摘要： Seismic structure inversions have been used to study the solar interior for decades. With the high-precision frequencies obtained using data from the Kepler mission, it has now become possible to study other solar-like oscillators using structure inversions, including both main-sequence and subgiant stars. Subgiant stars are particularly interesting because they exhibit modes of mixed acoustic-buoyancy nature, which provide the opportunity to probe the deeper region of stellar cores. This work examines whether the structure inversion techniques developed for the pure acoustic modes of the Sun and other main-sequence stars are still valid for mixed modes observed in subgiant stars. We construct two grids of models: one of main-sequence stars and one of early subgiant stars. Using these grids, we examine two different parts of the inversion procedure. First, we examine what we call the "kernel errors", which measure how well the mode sensitivity functions can recover known frequency differences between two models. Second, we test how these kernel errors affect the ability of an inversion to infer known structure differences. On the main sequence, we find that reliable structure inversion results can be obtained across the entire range of masses and large frequency separations we consider. On the subgiant branch, however, the rapid evolution of mixed modes leads to large kernel errors and hence difficulty recovering known structure differences. Our tests show that using mixed modes to infer the structure of subgiant stars reliably will require improvements to current fitting approaches and modifications to the structure inversion techniques.