Constraining the unexplored period between the dark ages and reionization with observations of the global 21 cm signal
Constraining the unexplored period between the dark ages and reionization with observations of the global 21 cm signal
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DOI：
10.1103/physrevd.82.023006
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发表时间：
2010-05
影响因子：
5
通讯作者：
J. Pritchard;A. Loeb
中科院分区：
文献类型：
--
作者：
J. Pritchard;A. Loeb
用单偶极实验观测红移21厘米中性氢谱线的全球亮温的频率依赖性是可能的。在本文中，我们开发了一个Fisher矩阵形式主义计算的灵敏度，这些仪器的21厘米信号的再电离和黑暗时代。我们证明了持续时间{Delta}z <或约的快速再电离历史。2可以被约束，条件是局部前景可以由低阶多项式很好地建模。然后，它表明，在范围{nu}=50-100 MHz的观测可以切实约束的Ly{alpha}和x射线发射率的第一批恒星形成在z{approx}15-25，只要系统的温度残差可以控制到小于1 mK。最后，我们证明了探测来自星星形成前的黑暗时代的21厘米信号的困难。
Observations of the frequency dependence of the global brightness temperature of the redshifted 21 cm line of neutral hydrogen may be possible with single dipole experiments. In this paper, we develop a Fisher matrix formalism for calculating the sensitivity of such instruments to the 21 cm signal from reionization and the dark ages. We show that rapid reionization histories with duration {Delta}z < or approx. 2 can be constrained, provided that local foregrounds can be well modeled by low order polynomials. It is then shown that observations in the range {nu}=50-100 MHz can feasibly constrain the Ly{alpha} and x-ray emissivity of the first stars forming at z{approx}15-25, provided that systematic temperature residuals can be controlled to less than 1 mK. Finally, we demonstrate the difficulty of detecting the 21 cm signal from the dark ages before star formation.