Probing the first galaxies with the Square Kilometer Array
Probing the first galaxies with the Square Kilometer Array
复制标题
用平方公里阵列探测第一个星系
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
A. Cooray
中科院分区：
文献类型：
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作者：
M. G. Santos;M. Silva;J. Pritchard;R. Cen;A. Cooray
对再电离前中性氢21厘米谱线亮温各向异性的观测将有助于了解第一批恒星和星系的诞生。本文利用大规模半数值模拟分析了第一批星系成团产生的莱曼-α通量空间波动对21厘米信号的印记。我们表明，如平方公里阵列（SKA）的实验可以探测到这个信号在再电离的开始，给我们重要的信息的紫外线发射光谱的第一批恒星和表征他们的宿主星系。SKA寻路器的总收集面积的10%应该能够在红移z <1020（对应于频率v> 1067 MHz）处对21 cm的功率谱进行统计检测。然后，我们表明，SKA应该能够测量的三维功率谱作为一个函数的角度与视线和讨论使用的红移空间失真的一种方式来分离出的21厘米功率谱的不同组成部分。我们证明，至少在Lyα波动是线性的大尺度上，它们可以作为一种独立于模型的方法来提取由于这些Lyα波动的功率谱。
Observations of anisotropies in the brightness temperature of the 21 cm line of neutral hydrogen from the period before reionization would shed light on the dawn of the first stars and galaxies. In this paper, we use large-scale semi-numerical simulations to analyse the imprint on the 21 cm signal of spatial fluctuations in the Lyman-α flux arising from the clustering of the first galaxies. We show that an experiment such as the Square Kilometer Array (SKA) can probe this signal at the onset of reionization, giving us important information about the UV emission spectra of the first stars and characterizing their host galaxies. SKA-pathfinders with ∼10% of the full collecting area should be capable of making a statistical detection of the 21 cm power spectrum at redshifts z <∼ 20 (corresponding to frequencies ν >∼ 67 MHz). We then show that the SKA should be able to measure the three dimensional power spectrum as a function of the angle with the line of sight and discuss the use of the redshift space distortions as a way to separate out the different components of the 21 cm power spectrum. We demonstrate that, at least on large scales where the Lyα fluctuations are linear, they can be used as a model independent way to extract the power spectra due to these Lyα fluctuations.