标题： 第三星族恒星能否成为并合双黑洞和极金属贫乏星的主要起源？ 显示英文标题

标题： Can Population III stars be major origins of both merging binary black holes and extremely metal poor stars?

摘要： 第三星族（Pop III）恒星，也被称为第一代恒星或金属零恒星，是由原始气体组成的。我们研究了它们是否可以成为合并双黑洞（BHs）和极贫金属星的主要起源。极贫金属星的丰度模式有助于追溯第三星族恒星的特性。我们证实了之前的论点，即观测到的黑洞合并率需要第三星族恒星形成效率比理论预测值高10倍，而宇宙再电离历史仍然允许这种较高的第三星族恒星形成效率。 另一方面，我们新发现极贫金属星的元素丰度模式仅允许第三星族初始质量函数的最小质量为$\sim 15 - 27$ $M_\odot$ 。换句话说，最小质量不能与上下方分别产生中子星和黑洞的临界质量有太大偏差。 第三星族恒星可能是合并双黑洞的主要来源，但我们的研究表明，在假设极贫金属星是由原始气体与第三星族超新星喷发物混合而成的情况下，第三星族恒星作为起源的参数空间被缩小了。 显示英文摘要

摘要： Population (Pop) III stars, first stars, or metal-free stars are made of primordial gas. We have examined if they can be dominant origins of merging binary black holes (BHs) and extremely metal-poor stars. The abundance pattern of EMP stars is helpful to trace back the properties of Pop III stars. We have confirmed previous arguments that the observed BH merger rate needs Pop III star formation efficiency 10 times larger than theoretically predicted values, while the cosmic reionization history still permits such a high Pop III star formation efficiency. On the other hand, we have newly found that the elemental abundance pattern of EMP stars only allows the Pop III initial mass function with the minimum mass of $\sim 15 - 27$ $M_\odot$. In other words, the minimum mass must not deviate largely from the critical mass below and above which Pop III stars leave behind neutron stars and BHs, respectively. Pop III stars may be still a dominant origin of merging binary BHs but our study has reduced the allowed parameter space under a hypothesis that EMP stars are formed from primordial gas mixed with Pop III supernova ejecta.