The observational studies of high-redshift Ly$\alpha$ emission-line galaxies
Abstract
The study of high-redshift {{Ly$\alpha$ 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, Ly$\alpha$ 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 Ly$\alpha$ emitting galaxies using the narrow-band photometric technique and spectroscopic observations. This paper mainly introduces the progress in the study of Ly$\alpha$ emitting galaxies at redshift $> 2$ in terms of properties of clustering, stellar populations and nebular emissions, star formation, morphologies of ultra-violet continuum and Ly$\alpha$ 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 Ly$\alpha$ emitting galaxies at extremely high redshifts.
