论文标题
Autterosic恒星模型：最初氦气的处理系统学
Asteroseismic stellar modelling: systematics from the treatment of the initial helium abundance
论文作者
论文摘要
尽管最初的氦气丰度是建模太阳能型恒星的重要成分，但在这些恒星中的丰度仍然是一个受约束的观察性质。这是因为这些恒星的有效温度不足以允许氦气电离，在采用光谱技术时不允许对其丰度得出任何结论。为此，恒星模块均通过半经验氦与重量元素比估计初始氦气的丰度，该元素比标准的大爆炸核合成值固定在标准。 Depending on the choice of solar composition used in stellar model computations, the helium-to-heavy element ratio, ($ΔY/ΔZ$) is found to vary between 1 and 3. In this study, we use the Kepler "LEGACY" stellar sample, for which precise seismic data is available, and explore the systematic uncertainties on the inferred stellar parameters (radius, mass, and age) arising from adopting different values of $Δy/Δz$，特别是1.4和2.0。用较高$Δy /Δz$构建的恒星网格值可得出较低的半径和质量估计。我们发现半径，质量和年龄的系统不确定性分别为1.1％，2.6％和13.1％。
Despite the fact that the initial helium abundance is an essential ingredient in modelling solar-type stars, its abundance in these stars remains a poorly constrained observational property. This is because the effective temperature in these stars is not high enough to allow helium ionization, not allowing any conclusions on its abundance when spectroscopic techniques are employed. To this end, stellar modellers resort to estimating the initial helium abundance via a semi-empirical helium-to-heavy element ratio, anchored to the the standard Big Bang nucleosynthesis value. Depending on the choice of solar composition used in stellar model computations, the helium-to-heavy element ratio, ($ΔY/ΔZ$) is found to vary between 1 and 3. In this study, we use the Kepler "LEGACY" stellar sample, for which precise seismic data is available, and explore the systematic uncertainties on the inferred stellar parameters (radius, mass, and age) arising from adopting different values of $ΔY/ΔZ$, specifically, 1.4 and 2.0. The stellar grid constructed with a higher $ΔY / ΔZ$ value yields lower radius and mass estimates. We found systematic uncertainties of 1.1 per cent, 2.6 per cent, and 13.1 per cent on radius, mass, and ages, respectively.
