论文标题
关于B型矮人的混合和氦气核心质量的多样性。
On the diversity of mixing and helium core masses of B-type dwarfs from gravity-mode asteroseismology
论文作者
论文摘要
银河系的化学演化在很大程度上是由巨大恒星产量的指导。它们的进化受到内部混合的严重影响，使恒星的寿命更长，并在主要序列演变结束时产生更大的氦气芯。 Asterosology是通过提供振荡恒星内部物理学的直接探针来研究恒星内饰的强大工具。这项工作重新审查了Kepler空间望远镜观察到的26个缓慢脉动B恒星的最近得出的内部混合曲线，以便研究混合曲线实际上可以彼此区分的混合曲线，并为在主要进化时获得的预期氦核质量提供了预测。我们发现，对于这些恒星中的五个，混合曲线是明确得出的，而其余的恒星至少具有另一个混合曲线，可以很好地解释振荡。比指数扩散的过冲比对流渗透是约55％的恒星，而在包膜中则优选分层混合（〜39％）。我们估计在主要序列演化结束时获得的预期氦核质量，发现它们受到恒星信封中发生的混合量的高度影响。
The chemical evolution of the Galaxy is largely guided by the yields from massive stars. Their evolution is heavily influenced by their internal mixing, allowing the stars to live longer and yield a more massive helium core at the end of their main-sequence evolution. Asteroseismology is a powerful tool for studying stellar interiors by providing direct probes of the interior physics of the oscillating stars. This work revisits the recently derived internal mixing profiles of 26 slowly pulsating B stars observed by the Kepler space telescope, in order to investigate how well the mixing profiles can in fact be distinguished from one another as well as provide predictions for the expected helium core masses obtained at the end of the main-sequence evolution. We find that for five of these stars the mixing profile is derived unambiguously, while the remaining stars have at least one other mixing profile which explains the oscillations equally well. Convective penetration is preferred over exponential diffusive overshoot for ~55% of the stars, while stratified mixing is preferred in the envelope (~39%). We estimate the expected helium core masses obtained at the end of the main-sequence evolution and find them to be highly influenced by the estimated amount of mixing occurring in the envelopes of the stars.
