A self-consistent semi-analytic model for Population III star formation in minihaloes
A self-consistent semi-analytic model for Population III star formation in minihaloes
复制标题
迷你晕中 III 族恒星形成的自洽半解析模型
DOI：
10.1093/mnras/stad2308
复制
发表时间：
2023
影响因子：
4.8
通讯作者：
Furlanetto, Steven R.
中科院分区：
文献类型：
--
作者：
Hegde, Sahil;Furlanetto, Steven R.
第一批恒星的形成标志着我们宇宙历史上的一个分水岭时刻。作为第一个发光结构，这些恒星(也被称为种群III，或Pop III恒星)孕育了第一个星系，并开始了重新电离的过程。我们建立了一个分析模型，在存在起伏的紫外线背景、早期宇宙的残余暗物质(DM)-重子相对速度和X射线背景的情况下，自洽地追踪迷你晕内POP III恒星的形成，这些背景在很大程度上抑制了气体的冷却，推迟了第一代恒星的形成。我们在一个早期恒星形成的半解析模型中展示了这个框架的实用性，该模型也跟踪了这些光晕中的Pop III和Pop II恒星形成之间的转变。使用我们允许POP III恒星形成的标准的新处方，我们跟踪了从z=50到z=6的一组DM晕，并检查了全球恒星形成历史，发现每个过程都定义了它自己的关键时期：(I)气流速度在最高红移时占主导地位(z≳30)，(Ii)UV背景在中间时间(30≳z≳15)确定基调，以及(3)X射线控制POP III恒星形成的最新时间(z≲15)。在我们所有的模型中，Pop III恒星继续形成到∼7-10，届时它们的超新星将有可能用即将到来的仪器观测到。最后，我们在全球21厘米氢原子的自旋翻转信号中识别了Pop III物理中的变化特征。
The formation of the first stars marks a watershed moment in the history of our Universe. As the first luminous structures, these stars (also known as Population III, or Pop III stars) seed the first galaxies and begin the process of reionization. We construct an analytic model to self-consistently trace the formation of Pop III stars inside minihaloes in the presence of the fluctuating ultraviolet background, relic dark matter (DM)-baryon relative velocities from the early universe, and an X-ray background, which largely work to suppress cooling of gas and delay the formation of this first generation of stars. We demonstrate the utility of this framework in a semi-analytic model for early star formation that also follows the transition between Pop III and Pop II star formation inside these haloes. Using our new prescription for the criteria allowing Pop III star formation, we follow a population of DM haloes fromz= 50 throughz= 6 and examine the global star formation history, finding that each process defines its own key epoch: (i) the stream velocity dominates at the highest redshifts (z≳ 30), (ii) the UV background sets the tone at intermediate times (30 ≳z≳ 15), and (iii) X-rays control the end of Pop III star formation at the latest times (z≲ 15). In all of our models, Pop III stars continue to form down toz∼ 7–10, when their supernovae will be potentially observable with forthcoming instruments. Finally, we identify the signatures of variations in the Pop III physics in the global 21-cm spin–flip signal of atomic hydrogen.