Stellar Evolution at Low Metallicity
Stellar Evolution at Low Metallicity
复制标题
低金属丰度下的恒星演化
DOI：
10.1017/s1743921308020528
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
S. Ekström
中科院分区：
文献类型：
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作者：
R. Hirschi;C. Chiappini;G. Meynet;André;A Maeder;S. Ekström
大质量恒星在宇宙的早期演化中发挥了关键作用。它们与第一个光晕一起形成，并开始再电离。因此，了解它们的进化是非常重要的。本文首先回顾了金属丰度(Z)对大质量恒星演化的影响。然后，我们描述了旋转引起的混合和质量损失在极低z下的强烈影响。强混合导致了大量的初级14N， 13C和22Ne的产生。在红超巨星阶段的质量损失使得沃尔夫-拉叶星、Ib型、c型超新星和可能的伽玛射线暴（GRBs）的产生几乎达到Z = 0，对于质量大于60 M⊙的恒星。用旋转恒星模型计算的银河化学演化模型能更好地再现N/O、C/O和12C/13C的早期演化。最后，讨论了伽玛暴背景下磁场的影响。
Abstract Massive stars played a key role in the early evolution of the Universe. They formed with the first halos and started the re-ionisation. It is therefore very important to understand their evolution. In this review, we first recall the effect of metallicity (Z) on the evolution of massive stars. We then describe the strong impact of rotation induced mixing and mass loss at very low Z. The strong mixing leads to a significant production of primary 14N, 13C and 22Ne. Mass loss during the red supergiant stage allows the production of Wolf-Rayet stars, type Ib,c supernovae and possibly gamma-ray bursts (GRBs) down to almost Z = 0 for stars more massive than 60 M⊙. Galactic chemical evolution models calculated with models of rotating stars better reproduce the early evolution of N/O, C/O and 12C/13C. Finally, the impact of magnetic fields is discussed in the context of GRBs.