Far-Infrared Spectroscopic Survey of Near-by Interstellar Clouds

远红外[C II]谱线（^2P_<3/2>-^2P_<1/2>，157.7409 μ m）由单离子化碳（C^+）发射，是中性星际云的主要冷却剂。因此，对[C II]线的观测对于揭示星际云的物理状态，特别是能量收支是至关重要的，我们利用专用的BICE观测仪器成功地对[C II]线进行了巡天观测，观测结果对星际物理具有重要意义。然而，由于在朝向银道面的一条直线上有各种各样的分量，观测结果相当复杂，因此，对在一条直线上有单一分量的单个云的[C II]观测对于了解[C II]发射区的物理性质是非常重要的。为了制作[C II]发射区的模板，我们观察了猎户座区域，这是最具代表性的猎户座恒星形成区域。1994年9月3日在日本三陆气球中心用BICE对猎户座进行了观测，发现猎户座区存在多组不同物理参数的[C Ⅱ]发射区。利用这些结果，我们重新研究了我们以前对银河系平面的观测。

The far-infrared [C II] spectral line (^2P_<3/2>-^2P_<1/2>,157.7409 mum), which is emitted by singly ionized carbon (C^+), is the dominant coolant of neutral interstellar clouds. Hence observations of the line is crucial to reveal the physical states, especially the energy budget, of interstellar clouds.We have been successfully making survey observations of the [C II] line using a dedicated observing instrument BICE.The observational results are very important for interstellar physics. However, since there are various components in a line sight toward the Galactic plane, the observational results are rather complicated.Hence the [C II] observations of indivudual clouds which have a single component in a line sight are very important to understand the physical properties of the [C II] emitting regions. To make templates of [C II] emitting regions, we observed the Orion regions, which is the most representative massive-star-forming regions. The observation was carried out on September 3,1994, from the Sanriku Balloon Center, using the BICE.The observation revelaed that there are several groups of [C II] emitting regions with different physical parameters in the Orion regions. Using the results, we reinvestigated our previous [C II] observations of the Galactic plane.