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

该项目的目标包括：(A)对在z=3.1的SSA22场(C.C.Steidel，APJ 2000，和T.Hayashino，AJ 2004)发现的Lya发射体(LAE)大尺度结构(LAE)周围区域进行广域深度观测，以揭示大尺度高红移星系的空间分布；(B)通过与控制场的比较，揭示SSA22大尺度结构(LAE)中LAE的数超密度；以及(C)揭示LAE在LSS中的三维空间分布。通过分析斯巴鲁2005密集程序在两个平方度场(z=3.1时200Mpc×100Mpc)上的观测数据，我们得到了以下结果，基本达到了上述项目的目标。(1)对红移z=3.09±0.03的LAES进行窄带滤波(CW497 nm/BW8 nm)测量，在SSA22测区探测到约2000个LAE，在大尺度上表现出很强的不均匀分布，即在LSS的西侧发现了另一个10OMpc尺度的LSS，并发现了一个直径为70Mpc的大空洞。(2)SSA22测区中200Mpc×100Mpc×6OMpc测区的LAE数密度几乎是同红移区的两倍，但SSA22测区不仅含有LSSs，而且存在较大的空洞。标准的清洁发展机制结构形成情景有可能在z=3.1的情况下以仅10^-8的概率构建如此大的高密度区域。(3)通过对200个LaE的光谱观测，我们发现了LSS中LaE的三维丝状结构，这是标准CDM模拟普遍预期的结果。

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.