论文标题
脉动驱动的质量损失来自金属贫困簇的恒星合并后面的大量恒星
Pulsation-driven mass loss from massive stars behind stellar mergers in metal-poor dense clusters
论文作者
论文摘要
最近发现的高红移（Z> 6）超质量黑洞（SMBH）有利于Protogalaxies中巨大的种子BHS的形成。一种可能的情况是在密集的群集中通过失控的恒星碰撞形成巨大的恒星〜1e3-1e4 msun，留下了巨大的BHS而没有大量的质量损失。我们研究具有零年龄的主要序列（ZAMS）质量MZAMS/MSUN = 300-3000和金属性Z/ZSUN = 0-0.1的巨大恒星的脉动不稳定性，并讨论脉动驱动的质量损失是否会导致大规模的BH形成。在MS阶段，由epsilon机制激发的脉动不稳定性在〜1e3年中增长。随着恒星质量和金属性的增加，质量损失率增加到<1e-3 msun/yr。在红色的超级巨型（RSG）阶段中，在氢离子化区中运行的Kappa机制激发了不稳定性，并在约10年内生长更快。 RSG质量损失速率几乎与金属性无关，并在〜1E-3-1E-2 MSUN/YR范围内分布。进行恒星结构计算，包括由于脉动驱动的风，我们发现MZAMS/MSUN = 300-3000的恒星模型可以留下比〜200-1200 msun更大的残余BHS。我们得出的结论是，大规模的合并产品可以在z> 6处观察到的怪物SMBH。
The recent discovery of high-redshift (z > 6) supermassive black holes (SMBH) favors the formation of massive seed BHs in protogalaxies. One possible scenario is formation of massive stars ~ 1e3-1e4 Msun via runaway stellar collisions in a dense cluster, leaving behind massive BHs without significant mass loss. We study the pulsational instability of massive stars with the zero-age main-sequence (ZAMS) mass Mzams/Msun = 300-3000 and metallicity Z/Zsun = 0-0.1, and discuss whether or not pulsation-driven mass loss prevents massive BH formation. In the MS phase, the pulsational instability excited by the epsilon-mechanism grows in ~ 1e3 yrs. As the stellar mass and metallicity increase, the mass-loss rate increases to < 1e-3 Msun/yr. In the red super-giant (RSG) phase, the instability is excited by the kappa-mechanism operating in the hydrogen ionization zone and grows more rapidly in ~ 10 yrs. The RSG mass-loss rate is almost independent of metallicity and distributes in the range of ~ 1e-3-1e-2 Msun/yr. Conducting the stellar structure calculations including feedback due to pulsation-driven winds, we find that the stellar models of Mzams/Msun = 300-3000 can leave behind remnant BHs more massive than ~ 200-1200 Msun. We conclude that massive merger products can seed monster SMBHs observed at z > 6.
