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 6.

中文翻译：

---

贫金属密集星团中恒星合并背后的大质量恒星的脉动驱动质量损失

最近发现的高红移 (z > 6) 超大质量黑洞 (SMBH) 有利于原星系中大质量种子 BH 的形成。一种可能的情况是通过密集星团中失控的恒星碰撞形成大质量恒星~1e3-1e4 Msun，留下大质量BHs而没有显着的质量损失。我们研究了零年龄主序 (ZAMS) 质量 Mzams/Msun = 300-3000 和金属丰度 Z/Zsun = 0-0.1 的大质量恒星的脉动不稳定性，并讨论了脉动驱动的质量损失是否阻止了大质量 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丰度的增加，质量损失率增加到 6。