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

再电离时期，星系间气体从中性和不透明到高度电离，因此是透明的，是宇宙演化的关键时期。确定这种情况发生时的红移以及电离星系际气体的光子来源是观测宇宙学目前的前沿之一。 最近在确定高红移星系群，特别是莱曼α发射星系群方面取得的巨大进展，有可能回答这个过程何时发生的问题。该项目将开发大型同质星系样本，以确定高红移超亮星系的特性。 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，鼓励他们参与科学，对他们进行观测方法和仪器方面的培训，指导他们掌握大型成像和光谱数据集的计算机处理和还原技术，并提供指导，特别强调鼓励女学生。观测结果表明，高红移的莱曼阿尔法埃塞尔比（LAE）分数下降超过7，这被解释为标志着在这个红移的再电离的开始。 然而，最明亮的LAEs似乎没有显示出这样的演变，也可能表现出更复杂的线轮廓比低光度LAEs，这表明最明亮的LAEs是保护自己免受IGM的演变中性产生高度电离的环境。 因此，星系可以直接被看到，而不受周围星系际介质的散射。 拟议的调查的目的是观察一个120平方度的领域，以适度的深度使用超Suprime-Cam的斯巴鲁望远镜，以开发一个大的统一选择的样本非常明亮的LAEs，以及一个非常大的样本更中等亮度LAEs，我们可以确定从红移5到红移7的LAEs的属性。从这些样本中，研究人员将能够确定LAEs如何依赖于该红移范围内的环境和光度，以及估计最明亮LAEs中的电离光子产生和HII孔隙率的增长。再电离边界附近星系的性质的确定，特别是它们的电离光子的产生，将提供强有力的约束的理论模型的星系际气体的演化，星系的演化，和结构的形成在高红移。

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.