The first generation of stars, often called Population III (or Pop III), form from metal-free primordial gas at redshifts z ∼ 30 and below. They dominate the cosmic star-formation history until z ∼ 15–20, at which point the formation of metal-enriched Population II stars takes over. We review current theoretical models for the formation, properties, and impact of Pop III stars and discuss existing and future observational constraints. Key takeaways from this review include the following: ▪Primordial gas is highly susceptible to fragmentation and Pop III stars form as members of small clusters with a logarithmically flat mass function.▪Feedback from massive Pop III stars plays a central role in regulating subsequent star formation, but major uncertainties remain regarding its immediate impact.▪In extreme conditions, supermassive Pop III stars can form, reaching masses of several 105M⊙. Their remnants may be the seeds of the supermassive black holes observed in high-redshift quasars.▪Direct observations of Pop III stars in the early Universe remain extremely challenging. Indirect constraints from the global 21-cm signal or gravitational waves are more promising.▪Stellar archeological surveys allow us to constrain both the low-mass and the high-mass ends of the Pop III mass distribution. Observations suggest that most massive Pop III stars end their lives as core-collapse supernovae rather than as pair-instability supernovae.

中文翻译：

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第一颗恒星：形成、性质和影响


第一代恒星，通常被称为种群 III（或 Pop III），由红移 z ∼ 30 及以下的无金属原始气体形成。它们在宇宙恒星形成历史中占据主导地位，直到 z ∼ 15-20，此时富含金属的 Population II 恒星的形成占据主导地位。我们回顾了当前关于 Pop III 星形成、特性和影响的理论模型，并讨论了现有和未来的观测限制。这篇综述的主要结论包括：▪原始气体极易碎裂，Pop III 星是具有对数平坦质量函数的小星团的成员。▪来自大质量 Pop III 星的反馈在调节随后的恒星形成中起着核心作用，但其直接影响仍然存在重大不确定性。▪在极端条件下，超大质量 Pop III 星可以形成， 质量达到几 105M⊙。它们的残余物可能是在高红移类星体中观察到的超大质量黑洞的种子。 ▪来自全球 21 cm 信号或引力波的间接约束更有希望。▪恒星考古调查使我们能够约束 Pop III 质量分布的低质量和高质量末端。观测表明，大多数大质量 Pop III 恒星以核心坍缩超新星而不是成对不稳定的超新星结束它们的生命。