本项目将基于已经申请到和将要申请的国外大口径地面光学/红外望远镜时间，用我们自己设计和购买的中心波长在3928埃，带宽为70埃的窄带滤光片对选定的天区做窄带深曝光观测。结合已有的相邻宽带归档成像数据，我们将建立一个红移在2.23±0.03的莱曼α发射线星系（LAEs）样本。这一样本将比相近红移处莱曼α发射线星系的已有的观测深2-3倍。基于这一前所未有的深度曝光和高空间分辨率的LAEs样本，我们将对LAEs的尘埃消光、恒星形成率、恒星质量、星系形态、环境、面亮度分布等进行研究。进而对高红移的小质量、低恒星形成率的星系的恒星形成模式以及对总光度密度和恒星形成率密度的贡献做出观测限制。结合对近红外窄带观测选取的位于相同红移的Hα发射线星系的研究将使我们对红移2-3处的恒星形成星系有一个更为全面的认识。

Utilizing the awarded observing time on ground-based large optical/near-infrared telescopes and our customized narrowband filter that centers at 3928 angstrom and has a bandwidth of 70 angstrom, we will carry out deep narrowband surveys for a few well-studied fields. Taking advantage of the publicly available adjacent broad-band images of these fields, a sample of Lyα emitting galaxies (LAEs) at redshift 2.23±0.03 will be identified. Our survey will go 2-3 times deeper than published narrow-band surveys at similar redshift. Based on this as-yet unexplored sample, properties of Lyα emitters, such as dust extinction, star formation rate, stellar mass, morphology, environment and surface brightness profile will be studied. Furthermore, we will put observational constraints on the mode of star formation of high-redshift low mass galaxies and their contribution to the total luminosity and star formation rate densities. Taken together the studies of LAEs and Hα emitters at the same redshift, as identified by near-infrared narrow-band surveys, it will give us a more complete census of star-forming galaxies at z~2-3.