Wide Field Deep Survey for Ly α Emitters around a Large Scale Structure at Redshift 3.1

本项目的目的包括：(A)在z=3.1的SSA22场（C.C. Steidel, ApJ 2000, & T. Hayashino, AJ 2004）中发现的Lya发射体（LAEs）的大尺度结构（LLS）周围区域的宽场深度调查，以揭示高红移星系在非常大尺度的空间分布；(B)通过与对照场的比较，揭示z=3.1的SSA22 LLS中LAEs的数量过密度。(C)揭示LSS中LAEs的三维空间分布。通过对斯巴鲁2005集约计划获得的2平方度场（200Mpc×100Mpc在共动坐标系中z=3.1）观测数据的分析，我们得到了以下结果，几乎达到了我们上述项目的目标。(1)我们对红移z=3.09±0.03（共动空间6OMpc片）的LAEs进行了窄带滤波（CW497nm/BW8nm）巡天，在SSA22巡天区内探测到~2000个LAEs，在大尺度上表现出较强的不均匀性，即在之前发现的LSS的西侧又发现了一个10OMpc尺度的LSS，并发现了一个直径为70Mpc的大空洞。(2)我们发现，虽然SSA22调查区域不仅存在lse，而且存在较大的空洞，但在200Mpc×100Mpc×6OMpc SSA22调查体积中LAEs的数量密度几乎是控制场相同红移时的两倍。在标准CDM结构形成情景下，在z=3.1处构建如此大的高密度区域的概率仅为10^<-8>。(3)通过对约200个LAEs的光谱观测，我们发现了LSS中LAEs的三维丝状结构，这是标准CDM模拟所期望的。

The aim of this project consists of the followings, (A) Wide field deep survey for the region around the large scale structure (LLS) of Lya emitters (LAEs) discovered in SSA22 field at z=3.1 (C.C. Steidel, ApJ 2000, & T. Hayashino, AJ 2004) to reveal spatial distribution of high redshift galaxies in very large scale, (B) To reveal number overdensity of LAEs in the SSA22 LLS at z=3.1 by comparimg with controle fields, and (C) To reveal three dimensional spatial distribution of LAEs in the LSS discovered. Analysing the observational data over two square degree field (200Mpc×100Mpc at z=3.1 in comoving frame) obtained by the Subaru 2005 Intensive Program, we have gotten the following results which almost reach the goal of our project described above. (1) We carried out narrowband filter (CW497nm/BW8nm) survey for LAEs with redshifts z=3.09±0.03(6OMpc slice of comoving space) to detect ～2000 LAEs in the SSA22 survey area, showing strong inhomogeneous distribution in large scales, i.e., we have discovered another LSS of 10OMpc scale in the west of the LSS previously discovered, together with a big void of 70Mpc in diameter. (2) We have revealed that number density of LAEs in the SSA22 survey volume of 200Mpc×100Mpc×6OMpc is almost twice of it at the same redshift in controle fields, though the SSA22 survey region contains not only LSSs but a big void. Standard CDM structure formation scenario is possible to construct such a large high density region at z=3.1 with only 10^<-8> probability. (3) We have found out three dimensional filamentary structure of LAEs in the LSS by spectroscopic observation of ～200 LAEs, which is expected in general by standard CDM simulations.