The hydrogen clock to infer the upper stellar mass
The hydrogen clock to infer the upper stellar mass
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氢钟推断上层恒星质量
DOI：
10.1093/mnras/stac2485
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发表时间：
2022
影响因子：
4.8
通讯作者：
Higgins E
中科院分区：
文献类型：
--
作者：
Higgins E
质量最大的恒星控制着其宿主环境的化学富集、机械和辐射反馈以及能量收支。然而，大质量恒星最初是如何形成的，以及它们在一生中是如何演化的，目前还不清楚。在恒星物理学中，最大质量恒星的质量损失仍然是一个关键的未知问题，它会对恒星反馈和人口产生影响。在这项工作中，我们比较了质量范围从80到1000 M⊙的超大质量恒星（VMS）模型的网格，用于一系列输入物理。我们将接近爱丁顿极限的增强风与标准的o型星风进行比较，并对目前观测到的~ 50-100 M⊙恒星产生影响。我们探测了相关的表面H丰度(x)，以确定VMS与O星相比进化的关键特征。我们发现我们的模型与增强风处方的行为存在根本差异，在1.6 Myr的恒星质量上收敛，而不管初始质量如何。事实证明，由于VMS在质量阈值以上的化学均匀性，xx是破译初始质量的重要工具。我们使用exx来打破分离双星的两个组成部分的初始质量简并，以及狼蛛星云中WNh恒星的样本。我们发现，对于某些物体，初始质量是不受限制的，因此，甚至1000m⊙阶的初始质量也不排除。再加上1.6 Myr的质量周转率，xx可以用作“时钟”来确定上层恒星的质量。
The most massive stars dominate the chemical enrichment, mechanical and radiative feedback, and energy budget of their host environments. Yet how massive stars initially form and how they evolve throughout their lives is ambiguous. The mass loss of the most massive stars remains a key unknown in stellar physics, with consequences for stellar feedback and populations. In this work, we compare grids of very massive star (VMS) models with masses ranging from 80 to 1000 M⊙, for a range of input physics. We include enhanced winds close to the Eddington limit as a comparison to standard O-star winds, with consequences for present-day observations of ∼50–100 M⊙stars. We probe the relevant surface H abundances (Xs) to determine the key traits of VMS evolution compared to O stars. We find fundamental differences in the behaviour of our models with the enhanced-wind prescription, with a convergence on the stellar mass at 1.6 Myr, regardless of the initial mass. It turns out thatXsis an important tool in deciphering the initial mass due to the chemically homogeneous nature of VMS above a mass threshold. We useXsto break the degeneracy of the initial masses of both components of a detached binary, and a sample of WNh stars in the Tarantula Nebula. We find that for some objects, the initial masses are unrestricted and, as such, even initial masses of the order 1000 M⊙are not excluded. Coupled with the mass turnover at 1.6 Myr,Xscan be used as a ‘clock’ to determine the upper stellar mass.
DOI：
10.1017/s1743921314004657
发表时间：
2012-08
期刊：
Proceedings of the International Astronomical Union
影响因子：
--
作者：
J. Vink
通讯作者：
J. Vink