We review the current status of knowledge concerning the early phases of star formation during cosmic dawn. This includes the first generations of stars forming in the lowest mass dark matter halos in which cooling and condensation of gas with primordial composition is possible at very high redshift ( z > 20 $z > 20$ ), namely metal-free Population III stars, and the first generation of massive black holes forming at such early epochs, the so-called black hole seeds. The formation of black hole seeds as end states of the collapse of Population III stars, or via direct collapse scenarios, is discussed. In particular, special emphasis is given to the physics of supermassive stars as potential precursors of direct collapse black holes, in light of recent results of stellar evolution models, and of numerical simulations of the early stages of galaxy formation. Furthermore, we discuss the role of the cosmic radiation produced by the early generation of stars and black holes at high redshift in the process of reionization.

中文翻译：

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第一批恒星和黑洞的形成

我们回顾了关于宇宙黎明期间恒星形成早期阶段的知识现状。这包括在质量最低的暗物质晕中形成的第一代恒星，其中具有原始成分的气体在非常高的红移（ z > 20 $z > 20 $ ）下可能冷却和凝结，即无金属的第三族恒星，以及在如此早期形成的第一代大质量黑洞，即所谓的黑洞种子。黑洞种子的形成作为第三族恒星坍缩的最终状态，或通过直接坍缩情景进行了讨论。根据恒星演化模型的最新结果，特别强调了超大质量恒星作为直接坍缩黑洞的潜在前兆的物理学，以及星系形成早期阶段的数值模拟。此外，我们讨论了高红移的早期恒星和黑洞在再电离过程中产生的宇宙辐射的作用。