大样本恒星演化研究组知识库

由于缺乏足够的观测数据,大质量恒星的研究进展缓慢,到目前为止大质量恒星演化和黑洞详细的形成过程还存在较大争议。LIGO首次探测到恒星级双黑洞并合产生的引力波信号,这不但验证了爱因斯坦20世纪的预言,而且还证实了大质量双黑洞的存在。研究工作采用恒星演化程序MESA (Modules for Experiments in Stellar Astrophysics)计算孤立双星的演化,主星初始质量为20 M⊙～80 M⊙,金属丰度为0.000 1～0.002,初始双星质量比为0.7～0.9。双星系统通过稳定物质转移通道,形成总质量(15～110) M⊙范围内的双黑洞。形成双黑洞的并合时标强烈依赖于初始轨道周期,只有初始轨道周期不大于5 d的双星系统演化形成的双黑洞,通过引力波辐射损失角动量,最终可能在哈勃时标内并合。研究工作得到的结果可以解释部分现阶段已经探测到的引力波事件。

Due to the lack of observational constraints, progresses in the field of massive stars has been small, leading to controversy regarding their evolution, as well as how black holes are formed. Following LIGO's discovery of binary black hole systems, a better understanding of the formation of massive binary black hole systems is required. In this paper, we use MESA (Modules for Experiments in Stellar Astrophysics) to simulate the evolution of isolated massive binaries, taking into account processes such as stellar wind, mass transfer, and supernova explosions. In our work, we consider binaries with primary masses of 20 to 80 solar masses, mass ratios of 0.7 to 0.9, and metallicities of 0.000 1 to 0.002. We find that binaries that undergo stable mass transfer can form binary black holes with total masses of 15 to 110 solar masses. We also find that the gravitational merging timescales of the simulated binaries are strongly dependent on their initial orbital periods; in our sample, which does not include systems that undergo common envelope evolution, binaries with initial orbital periods of less than 5 days can merge within Hubble time, while those with initial orbital periods of more than 5 days cannot. Our results can explain the origin of some objects that have been observed by LIGO and Virgo.