Hydrogen 2p-2s Transition: Signals from the Epochs of Recombination and Reionization
Hydrogen 2p-2s Transition: Signals from the Epochs of Recombination and Reionization
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DOI：
10.1086/518650
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发表时间：
2007-04
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影响因子：
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通讯作者：
S. Sethi;R. Subrahmanyan;D. Roshi
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作者：
S. Sethi;R. Subrahmanyan;D. Roshi
我们提出了一种方法来研究的基础上可能观察到的2 p-2s的精细结构线的中性氢的宇宙学H II区域外的类星体和其他电离源的再电离时代的再电离时代。我们表明，对于在z = 6.3处观察到的光源的典型参数，该信号的强度与H I分数成正比，对于完全中性介质，其亮度温度为20 μK。从这个红移的精细结构线是在ν <$1 GHz可观察到的，我们讨论了与几个操作和未来的射电望远镜检测的前景。我们还计算了该信号在复合时期的特征;峰值亮度预计为100 μK，该信号出现在5-10 MHz的频率范围内。来自复合时代的信号几乎不可能被探测到，因为在这些频率下银河系的辐射非常明亮。
We propose a method to study the epoch of reionization based on the possible observation of 2p-2s fine-structure lines from the neutral hydrogen outside the cosmological H II regions enveloping QSOs and other ionizing sources in the reionization era. We show that for parameters typical of luminous sources observed at z ≃ 6.3, the strength of this signal, which is proportional to the H I fraction, has a brightness temperature ≃20 μK for a fully neutral medium. The fine-structure line from this redshift is observable at ν ≃ 1 GHz, and we discuss prospects for the detection with several operational and future radio telescopes. We also compute the characteristics of this signal from the epoch of recombination; the peak brightness is expected to be ≃100 μK, and this signal appears in the frequency range 5-10 MHz. The signal from the recombination era is nearly impossible to detect owing to the extreme brightness of the Galactic emission at these frequencies.