Evolution of Stars Just Below the Critical Mass for Iron Core Formation
Evolution of Stars Just Below the Critical Mass for Iron Core Formation
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铁核形成临界质量以下恒星的演化
DOI：
10.1017/s1743921312013579
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
Takashi Yoshida
中科院分区：
文献类型：
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作者：
Koh Takahashi;Hideyuki Umeda;Takashi Yoshida
我们在0.01M质量的精细网格下计算了初始质量为9- 11 M质量的恒星的演化。我们确定了Ne点火的低临界质量在一个没有经历过的热脉冲插曲的ONe核心。初始质量为9.83 M，CO核心质量为1.365 M。初始质量稍大于临界质量的星星会经历偏离中心的Ne+O点火。由于Ne+O燃烧和持续的电子捕获反应的能量产生率足够大，足以点燃Si，因此由于壳Si燃烧而形成Fe核。对于一颗刚好低于临界质量的星星来说，一个ONe核心继续收缩。在这样一个高密度的核心，通过C燃烧产生的核的电子捕获影响核心的演变。在20 Ne开始捕获电子后，核心可能会点燃O并经历O爆炸。它的命运可能是一颗电子俘获超新星。
We calculate the evolution of stars with their initial mass of 9-11M⊙ under very fine initial mass grid of 0.01M⊙. We determine the lower critical mass for Ne ignition in an ONe core that has not undergone the thermal pulse episode. The values are 9.83M⊙ for the initial mass and 1.365M⊙ for the CO core mass. A star with an initial mass slightly larger than the critical, undergoes an off-center Ne+O ignition. Since the energy production rate of Ne+O burning and lasting electron capture reactions is sufficiently large to ignite Si, an Fe core forms as a result of shell Si burning. For a star just below the critical mass, an ONe core continues to contract. In such a high density core, electron capture by nuclei produced through C burning affects the core evolution. After 20Ne starts to capture electrons, the core may ignite O and undergo O detonation. The fate may be an Electron Capture Supernova.