高红移Lyα发射线星系观测研究

The observational studies of high-redshift Lyα emission-line galaxies

高红移Lyα发射线星系的研究是理解宇宙恒星形成历史和早期星系形成的关键.作为高红移宇宙的重要组成部分,Lyα发射线星系是研究星系形成、宇宙恒星形成和结构形成历史以及宇宙再电离时期的重要探针.近20年随着8–10 m级地面望远镜和红外设备的发展,利用窄带测光技术和光谱观测,人们对Lyα发射线星系的研究取得了巨大进展.本文主要介绍由窄带测光技术选取的红移2以上的Lyα发射线星系的成团性质、恒星星族和发射线星云性质、恒星形成性质、紫外连续谱和Lyα发射线形态,与莱曼断裂星系的关系,对宇宙恒星形成率密度的贡献,以及极高红移Lyα发射线星系对宇宙再电离时期的限制等方面的研究进展.

The study of high-redshift Lyα emission-line galaxies is the key to understanding the cosmic star formation history and galaxy formation. As one of the most important constituents of the high-redshift universe, Lyα emitting galaxies are the best probe for studying galaxy formation, cosmic star formation and structure formation histories, and the epoch of cosmic re-ionization. In the past twenty years, with the advent of 8–10 m class telescopes and infrared equipments, people have made great progress in the selection and study of Lyα emitting galaxies using the narrow-band photometric technique and spectroscopic observations. This paper mainly introduces the progress in the study of Lyα emitting galaxies at redshift 〉 2 in terms of properties of clustering, stellar populations and nebular emissions, star formation, morphologies of ultra-violet continuum and Lyα emission line, relations with Lyman Break Galaxies, contributions to the cosmic star formation rate densities, and the constraints on the epoch of re-ionization from Lyα emitting galaxies at extremely high redshifts.