Observational study of galaxy evolution with large-scale surveys of molecular clouds along the Galactic plane

我们研制了用于双偏振观测的光波导正交码换能器(OMT)，安装在1.85m mm以下的望远镜上，使观测效率提高了2倍。利用该系统，我们成功地覆盖了沿银河平面1250平方度的范围，包括猎户座、金牛座、英仙座、天鹅座、加利福尼亚星云、蛇座等各种恒星形成区。Onishi等人对这一进展进行了总结。(2013年)。通过对猎户座分子云的观测研究，发现~(13)CO(2-1)线是精确推算分子云密度和温度的重要探针。

We developed waveguide-based Orthomode Transducers (OMT) for dual-polarization observations to be installed on the 1.85m mm-submm telescope, which improved the observation efficiency by a factor of 2. With this system, we have succeeded in covering 1250 square degrees along the Galactic plane including various star forming regions of Orion, Taurus, Perseus, Cygnus, California nebula, Serpens, and so on. The development is summarized in Onishi et al. (2013). We found that 13CO(2-1) line is an important probe to precisely derive the density and temperature of molecular clouds through an observational study of molecular clouds toward Orion molecular clouds.