Cosmological hydrogen recombination: populations of the high‐level substates
Cosmological hydrogen recombination: populations of the high‐level substates
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宇宙学氢重组：高级亚状态的群体
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
R. Sunyaev
中科院分区：
文献类型：
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作者：
J. Chluba;J. Rubiño;R. Sunyaev
本文给出了在宇宙氢复合过程中，由于束缚-束缚跃迁而引起的宇宙微波背景辐射（CMB）的光谱畸变的结果。我们扩展了之前对重组问题的处理（Rubino-Mart 'on等人，2006），现在包括主要的碰撞过程，并跟踪多达100个壳层的所有氢角动量子状态的演变。我们表明，由于宇宙的重子密度很低，即使在最高考虑的壳层内也没有达到完全统计平衡（SE），并且在低频下，当假设n > 2时完全SE时，复合谱是显著不同的。我们还直接比较了我们的结果的电离历史的Recfast代码的输出，特别是在低红移，而出现很大的差异。在汤姆逊可见度函数附近，电子分数相差约0.6%，这对温度和偏振功率谱的影响为-1%。此外，我们简短地讨论了自由-自由吸收和线加宽由于电子散射的束缚-束缚复合光谱和CMB角涨落的产生由于光子的散射内的高壳层的影响。
We present results for the spectral distortions of the Cosmic Microwave Background (CMB) arising due to bound-bound transitions during the epoch of cosmological hy- drogen recombination at frequencies down to ν � 100MHz. We extend our previous treatment of the recombination problem (Rubino-Mart´on et al. 2006) now including the main collisional processes and following the evolution of all the hydrogen angular momentum sub-states for up to 100 shells. We show that, due to the low baryon den- sity of the Universe, even within the highest considered shell full statistical equilibrium (SE) is not reached and that at low frequencies the recombination spectrum is signifi- cantly different when assuming full SE for n > 2. We also directly compare our results for the ionization history to the output of the Recfast code, showing that especially at low redshifts rather big differences arise. In the vicinity of the Thomson visibility function the electron fraction differs by roughly 0.6% which affects the temperature and polarization power spectra by � 1%. Furthermore we shortly discuss the influence of free-free absorption and line broadening due to electron scattering on the bound- bound recombination spectrum and the generation of CMB angular fluctuations due to scattering of photons within the high shells.