Multifrequency Analysis of 21 Centimeter Fluctuations from the Era of Reionization
Multifrequency Analysis of 21 Centimeter Fluctuations from the Era of Reionization
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DOI：
10.1086/429857
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发表时间：
2004-08
期刊：
影响因子：
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通讯作者：
Mário G. Santos;A. Cooray;L. Knox
中科院分区：
文献类型：
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作者：
Mário G. Santos;A. Cooray;L. Knox
我们研究了利用红移21厘米谱线发射的亮温起伏提取再电离时代中性氢分布的详细统计性质的前景。这一信号的探测由于来自前景源的污染而变得复杂，如扩散银河同步加速器和低射频自由辐射、来自电离区的河外自由辐射和射电点源。我们对这些前景进行建模，以确定在即将到来的实验中可以检测到21厘米波动的程度。我们发现，不仅从一个频率到另一个频率的相关性水平，而且前景相关性的函数形式都对前景去除有很大的影响。我们计算了21厘米起伏的角功率谱能被确定得多好。我们还表明，中性氢气分布相对于密度场的大范围偏差可以高精度地确定，并用于区分不同的再电离历史。
We study the prospects for extracting detailed statistical properties of the neutral hydrogen distribution during the era of reionization using the brightness temperature fluctuations from redshifted 21 cm line emission. Detection of this signal is complicated by contamination from foreground sources such as diffuse Galactic synchrotron and free-free emission at low radio frequencies, extragalactic free-free emission from ionized regions, and radio point sources. We model these foregrounds to determine the extent to which 21 cm fluctuations can be detected with upcoming experiments. We find that not only the level of correlation from one frequency to another but also the functional form of the foreground correlations has a substantial impact on foreground removal. We calculate how well the angular power spectra of the 21 cm fluctuations can be determined. We also show that the large-scale bias of the neutral hydrogen gas distribution with respect to the density field can be determined with high precision and used to distinguish between different reionization histories.