The Impact of the First Galaxies on Cosmic Dawn and Reionization
The Impact of the First Galaxies on Cosmic Dawn and Reionization
复制标题
第一个星系对宇宙黎明和再电离的影响
DOI：
10.1093/mnras/stac185
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
C. Mason
中科院分区：
文献类型：
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作者：
Julian B. Muñoz;Y. Qin;A. Mesinger;S. Murray;B. Greig;C. Mason
在宇宙黎明和再电离(红移z=5-30)期间，fiRst星系的形成触发了我们宇宙的最后一次重大相变，当时氢从冷和中性演化到热和电离。21厘米长的中性氢线将很快让我们绘制出这些宇宙里程碑的地图，并研究这些里程碑所在的星系。为了帮助解释这些观察结果，我们升级了公开可用的代码21cmFAST。我们引入了一种新的，fl可执行的附加反馈的参数化：来自非均匀的H2解离(Lyman-Werner；LW)背景和暗物质-重子相对速度，它恢复了最近的具有这两种效应的小规模流体动力学模拟的结果。作为21厘米结构进化(EOS)项目的2021年部分，我们进行了一个大型的“最佳猜测”模拟。这改进了之前发布的星系模型，该模型再现了观测到的紫外线光度函数(UVLF)，并包括了一批分子冷却的星系。由此产生的21厘米的全球信号和功率谱明显较弱，主要是由于与fi匹配所需的恒星形成率密度的更快演变。然而，我们预测HERA和SKA的信噪比都很高。我们演示了如何从21厘米的演化中推断出看不见的第一个fi星系的恒星到晕的质量关系。最后，我们认为由于相对速度引起的X射线加热的空间调制提供了在z≈10-15处可以在我们的fi基准模型中检测到的独特的声学特征。我们的第一个公开模拟是在整个宇宙黎明和再电离过程中联合使用非均匀LW和相对速度反馈的fi公开模拟，我们在以下链接上提供这些模拟：
The formation of the first galaxies during cosmic dawn and reionization (at redshifts z = 5–30), triggered the last major phase transition of our universe, as hydrogen evolved from cold and neutral to hot and ionized. The 21-cm line of neutral hydrogen will soon allow us to map these cosmic milestones and study the galaxies that dro v e them. To aid in interpreting these observations, we upgrade the publicly available code 21cmFAST . We introduce a new, flexible parametrization of the additive feedback from: an inhomogeneous, H 2 -dissociating (Lyman–Werner; LW) background; and dark matter – baryon relative velocities; which recovers results from recent, small-scale hydrodynamical simulations with both effects. We perform a large, ‘best-guess’ simulation as the 2021 installment of the Evolution of 21-cm Structure (EOS) project. This impro v es the previous release with a galaxy model that reproduces the observed UV luminosity functions (UVLFs), and by including a population of molecular-cooling galaxies. The resulting 21-cm global signal and power spectrum are significantly weaker, primarily due to a more rapid evolution of the star formation rate density required to match the UVLFs. Nevertheless, we forecast high signal-to-noise detections for both HERA and the SKA. We demonstrate how the stellar-to-halo mass relation of the unseen, first galaxies can be inferred from the 21-cm e volution. Finally, we sho w that the spatial modulation of X-ray heating due to relative velocities provides a unique acoustic signature that is detectable at z ≈ 10–15 in our fiducial model. Ours are the first public simulations with joint inhomogeneous LW and relativ e-v elocity feedback across the entire cosmic dawn and reionization, and we make them available at this link https:// scholar.harvard.edu/ julianbmunoz/eos-21 .