The Astrophysics of Hydrogen and Helium Reionization

该研究项目将研究宇宙中氢和氦的再电离，结合分析和数值方法来阐明再电离的物理基础，以及电离源的性质和丰度以及星系间介质（IGM）的特性如何影响再电离。该分析将进一步用于考虑再电离对这一过程的可观测特征的影响，包括高红移时来自氢的21厘米辐射的波动、对发射Ly-alpha的星系的调查、伽马射线暴的光谱以及Lyman-alpha森林的统计特性。这项研究的结果将用于指导当前和未来研究IGM中高红移星系、类星体和弥散气体发射的实验的最佳观测策略。这项工作的更广泛影响包括培训代表性不足的学生，以及通过网络可视化和模拟进行公众宣传。

This research program will examine the reionization of the Universe in both hydrogen and helium, combining analytical and numerical approaches to elucidate the physics underlying reionization and how it is influenced by the nature and abundance of the ionizing sources and the properties of the intergalactic medium (IGM). The analysis will be further employed to consider the impact of reionization on observable signatures of this process, including fluctuations in 21 cm radiation from hydrogen at high redshifts, surveys of Ly-alpha emitting galaxies, spectra of gamma-ray bursts, and the statistical properties of the Lyman-alpha forest. The results of this investigation will be used to guide optimal observing strategies for ongoing and future experiments to investigate emission from high-redshift galaxies, quasars, and diffuse gas in the IGM.The broader impacts of this work include training of underrepresented students, and public outreach through visualizations and simulations accessible through the web.