The role of soft photon injection and heating in 21 cm cosmology
The role of soft photon injection and heating in 21 cm cosmology
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软光子注入和加热在 21 cm 宇宙学中的作用
DOI：
10.1093/mnras/stad1540
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发表时间：
2023
影响因子：
4.8
通讯作者：
Acharya S
中科院分区：
文献类型：
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作者：
Acharya S
ARCADE无线电过剩和EDGE测量仍然令人困惑。两者之间的联系以前已经考虑过，但是，在这项工作中，我们强调了一个重要的相关影响，以前没有详细分析。通过使用cosmotherm进行软光子注入的宇宙热化计算，我们表明，对于21 cm信号产生，增强的无线电频谱失真和相关的加热之间的相互作用可以隐藏一个显着的无线电过剩再电离时代之前。我们说明了一个简单的幂律软光子源在衰变粒子的情况下，这种效果。即使过于简单化，CMB光谱畸变和21厘米宇宙学之间的联系也应该适用于更广泛的场景。这可能会显着影响来自现有的和未来的21厘米观测的环境无线电背景的演变的约束。特别是，一旦在建模中考虑到加热，现有数据排除的没有加热的情景可能成为可行的解决方案。我们的计算进一步强调了全球21厘米观测达到黑暗时代的重要性，在那里可以潜在地区分各种情况。
The ARCADE radio excess and EDGES measurement remain puzzling. A link between the two has been previously considered, however, in this work we highlight an important related effect that was not analysed in detail before. By performing cosmological thermalization calculations with soft photon injection usingcosmotherm, we show that for the 21 cm signal generation, the interplay between enhanced radio spectral distortions and the associated heating can hide a significant radio excess before the reionization era. We illustrate this effect for a simple power-law soft photon source in decaying particle scenarios. Even if simplistic, the uncovered link between CMB spectral distortions and 21 cm cosmology should apply to a much broader range of scenarios. This could significantly affect the constraints derived from existing and future 21 cm observations on the evolution of the ambient radio background. In particular, scenarios that would be ruled out by existing data without heating could become viable solutions once the heating is accounted for in the modelling. Our calculations furthermore highlight the importance of global 21 cm observations reaching into the dark ages, where various scenarios can potentially be distinguished.