Prospects for 21 cm Galaxy Cross-correlations with HERA and the Roman High-latitude Survey
Prospects for 21 cm Galaxy Cross-correlations with HERA and the Roman High-latitude Survey
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DOI：
10.3847/1538-4357/acaeb0
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发表时间：
2022-05
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影响因子：
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通讯作者：
P. La Plante;J. Mirocha;Adélie Gorce;A. Lidz;A. Parsons
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作者：
P. La Plante;J. Mirocha;Adélie Gorce;A. Lidz;A. Parsons
21 cm场与星系分布之间的互相关是再电离时代（EoR）的一个潜在探测器。21厘米信号跟踪星系际介质中的中性气体，在大的空间尺度上，这应该与高红移星系分布有关，高红移星系分布部分来源和跟踪电离气体。在不久的将来，预计氢再电离时代阵列（HERA）等干涉仪将提供21厘米功率谱的极其灵敏的测量。与此同时，Nancy Grace Roman太空望远镜（Roman）将产生迄今为止最广泛的EoR明亮星系目录。利用再电离的数值模拟，我们探讨了在EoR期间测量21 cm和星系场之间的交叉功率谱的前景。我们预测HERA和Roman之间的12σ探测，假设重叠的调查区域为500 deg 2，红移不确定性σ z = 0.01（如对Lyα发射星系的高纬度光谱调查所预期的那样），有效Lyα发射器占空比f LAE = 0.1。因此，HERA-Roman互功率谱可用于帮助验证HERA的21 cm探测。我们发现星系分布中的散粒噪声是检测的一个限制因素，因此使用Roman的补充观测应该优先考虑更深的观测，而不是覆盖更宽的视场。我们已经创建了一个公共GitHub存储库，其中包含计算的关键部分，该存储库随附于本文：https://github.com/plaplant/21cm_gal_cross_correlation。
The cross-correlation between the 21 cm field and the galaxy distribution is a potential probe of the Epoch of Reionization (EoR). The 21 cm signal traces neutral gas in the intergalactic medium and, on large spatial scales, this should be anticorrelated with the high-redshift galaxy distribution, which partly sources and tracks the ionized gas. In the near future, interferometers such as the Hydrogen Epoch of Reionization Array (HERA) are projected to provide extremely sensitive measurements of the 21 cm power spectrum. At the same time, the Nancy Grace Roman Space Telescope (Roman) will produce the most extensive catalog to date of bright galaxies from the EoR. Using seminumeric simulations of reionization, we explore the prospects for measuring the cross-power spectrum between the 21 cm and galaxy fields during the EoR. We forecast a 12σ detection between HERA and Roman, assuming an overlapping survey area of 500 deg2, redshift uncertainties of σ z = 0.01 (as expected for the high-latitude spectroscopic survey of Lyα-emitting galaxies), and an effective Lyα emitter duty cycle of f LAE = 0.1. Thus the HERA–Roman cross-power spectrum may be used to help verify 21 cm detections from HERA. We find that the shot-noise in the galaxy distribution is a limiting factor for detection, and so supplemental observations using Roman should prioritize deeper observations, rather than covering a wider field of view. We have made a public GitHub repository containing key parts of the calculation, which accompanies this paper: https://github.com/plaplant/21cm_gal_cross_correlation.