A Study of Large Scale structures of Galaxy Distribution in the Local Universe by means of Galaxy search in the Milky Way Region

为了弄清银河系后局部宇宙星系分布的大尺度结构，我们对该地区的星系进行了两次系统的搜寻：(1)寻找银河系后的IRAS星系(1994-1996)IRAS星系被定义为在60微米处的通量密度大于0.6Jy。在远红外波段，银河系的消光是如此之低，以至于即使在银河系地区也有可能探测到IRAS星系。我们获得了具有与已知IRAS星系相似的远红外特征的IRAS点源，并在远红外点源的位置上识别出光学上类似星系的物体。然后我们对尽可能多的候选星系进行了红移观测。我们的结果表明，银河系存在五个几乎垂直于银河系垂直分布的丝状结构，一个位于Puppis的星系团，其速度约为2000 Km/S，以及沿超北坐标的X轴方向存在一个大尺度结构，其大小为100MPC。我们还阐明了局部空洞的结构。(2)对银河系中心区域星系的目视搜索(1995-1996)IRAS星系搜索的结果也表明，在靠近银河系中心的空洞附近有一个明显的大空洞。为了确定空洞的真实性，我们通过施密特平板和一个带有大型可移动平台的显微镜进行了一次视觉搜索，这是由这项资助获得的。我们在大约1050平方度的范围内探测到了大约12000个候选星系。现在我们要对这些天体进行红移测量。通过后续的红移观测，我们可以弄清该地区的大尺度构造。

In order to clarify the large-scale structures of galaxy distribution of the Local Universe behind the Milky Way, we performed two systematic search for galaxies in this region.(1) A search for IRAS galaxies behind the Milky Way (1994-1996)IRAS galaxies are defined to have flux densities larger than 0.6 Jy at 60 mum. At far-infrared wavelengths Galactic extinction is so low that detection of IRAS galaxies is possible even at the Milky Way region. We picked up IRAS point sources with far-infrared features similar to known IRAS galaxies and identified optically galaxy-like objects on the positions of the far-infrared point souces. Then we carried out a redshift survey of the galaxy candidates as many as possible.Our results show the presence of five filamentary structures of galaxy distribution almost vertically crossing the Milky Way, a galaxy cluster at Puppis with about 2000 km/s, and a large-scale structure with a size of 100 Mpc along X-axis of the supergalctic coordinate. We also clarify the structure of the Local Void.(2) A visual search for galaxies at the Galactic center region (1995-1996)The results of the IRAS galaxy search also indicate an apparent largy nearby void toward the Galactic center. To ascertain the reality of the void, we carried out a visual search for galaxies by means of Schmidt plates and a microscope with a large movable stage, which was obtained by this Grant-in-Aid. We detected about 12000 galaxy candidates in about 1050 square degrees surveryed. Now we are going to carry out a redshift survery of these objects. We may clarify large-scale structures in this region by the follow-up redshift survery.