Collaborative Research: Hyper Suprime-Cam Wide Emission-Line Survey

再电离时代是宇宙演化的关键时期，当星系间气体从中性和不透明转变为高度电离，因此是透明的。确定红移发生的时间和电离星际气体的光子的来源代表了观测宇宙学的当前前沿之一。最近在识别高红移星系群方面取得的巨大进展，特别是发射莱曼阿尔法星系的星系，有可能回答这一过程何时发生的问题。该项目将开发大的、均匀的星系样本，用来确定高红移的超发光星系的性质。该项目的一个重要方面是为研究生和本科生提供研究机会，激发他们的兴趣并鼓励他们参与科学，培训他们使用观测方法和仪器，指导他们使用计算机处理和处理大型成像和光谱数据集的简化技术，并提供指导，重点是鼓励女学生。观测表明，高红移莱曼阿尔法发射体(LAE)的比例下降到红移7以上，这被解释为标志着在这个红移处重新电离的开始。然而，最亮的LAE似乎没有表现出这样的进化，而且也可能比低光度的LAE表现出更复杂的线型，这表明最亮的LAE通过产生高度电离的环境来保护自己免受IGM不断演变的中性的影响。因此，银河系可以直接看到，而不需要从周围的星际介质散射。拟议中的调查的目的是利用斯巴鲁望远镜上的Hyper SuPrime-Cam观测120平方度到中等深度的视场，以便开发一个大的均匀选择的非常明亮的LAE样本，以及一个非常大的中等亮度的LAE样本，从中我们可以确定从红移5到红移7的LAE的性质。从这些样本，研究人员将能够确定在这个红移范围内LAE是如何依赖于环境和光度的，并估计在最明亮的LAE中的电离光子产生和HII孔隙率的增长。确定再电离边界附近星系的性质，特别是它们的电离光子产生，将为星际气体演化、星系演化和高红移结构形成的理论模型提供强有力的约束。

The epoch of reionization, when the intergalactic gas went from being neutral and opaque to being very highly ionized, and therefore transparent, is a key period in the evolution of the Universe. Determining the redshift when this occurred and the sources of the photons that ionized the intergalactic gas represents one of the current frontiers in observational cosmology. The enormous recent progress in identifying populations of high-redshift galaxies, particularly the Lyman alpha emitting galaxies, has the potential to answer the question of when this process occurred. This project will develop large, homogeneous galaxy samples with which to determine the properties of the ultra-luminous galaxies at high redshift. An important aspect of this project is to provide research opportunities for graduate and undergraduate students that will engage their interest and encourage their participation in science, train them in observational methods and instruments, direct them in computer processing and reduction techniques for large imaging and spectroscopic data sets, and provide mentoring, with a particular emphasis on encouraging women students. Observations suggesting a drop in the high-redshift Lyman Alpha Emitter (LAE) fraction beyond a redshift of seven have been interpreted as marking the onset of reionization at this redshift. However, the most luminous LAEs do not appear to show such an evolution and may also exhibit more complex line profiles than lower-luminosity LAEs, suggesting that the most luminous LAEs are protecting themselves from the evolving neutrality of the IGM by generating highly ionized surroundings. As a consequence, the galaxy can be seen directly without scattering from the surrounding intergalactic medium. The aim of the proposed survey is to observe a 120 square degree field to moderate depth using Hyper Suprime-Cam on the Subaru telescope in order to develop a large uniformly-selected sample of very luminous LAEs, as well as a very large sample of more moderate-luminosity LAEs from which we can determine the properties of LAEs from redshift 5 to redshift 7. From these samples, the researchers will be able to determine how LAEs depend on environment and luminosity in this redshift range, as well as estimate the ionizing photon production in the most luminous LAEs and the growth of HII porosity. Determining properties of galaxies near the reionization boundary, and particularly their ionizing photon production, will provide strong constraints on theoretical models of the evolution of the intergalactic gas, the evolution of galaxies, and structure formation at high redshift.