Multi-Line Survey Observation of the Galactic Plane by Balloon-Borne Telescopes

它已被广泛证明，存在着各种阶段的气体，如原子，离子和分子在星际空间的银河系。其中氢21厘米线和CO 2.6毫米线分别通过中性氢原子气体和分子气体在研究银河系结构和物理化学阶段中发挥了重要作用。然而，我们以前的研究结果[CII]远红外线调查表明，存在一个新的星际气相，“扩散光解区”。在CO分子气体和氢原子气体之间的界面区域的光解区，是将来自发光恒星的紫外光和光学辐射转化为远红外辐射的主要冷却剂，因此，远红外光谱线是理解银河系星际空间/物质的关键，也是测量星际重元素丰度的工具。我们用空间红外望远镜（IRTS）和球载望远镜（BICE）进行了[CII] 158微米的宽天巡天，用欧洲红外空间天文台（ISO）进行了[OI] 63微米、[OIII] 52.88微米、[CII] 158微米、[NII] 122微米和[NIII] 57微米的宽天巡天。从这些数据中，我们已经表明，弥漫的光解区和弥漫电离区是重要的气相在银河系星际空间。

It has widely been demonstrated that there exist various stages of gas, such as atoms, ions, and molecules in the interstellar space of the Galaxy. Among them, hydrogen 21 cm line and CO 2.6 mm line have been playing important roles in investigations of the galactic structure and physical and chemical stage of the Galaxy through the neutral hydrogen atomic gas and molecular gas, respectively. However, the previous result of our study by a [CII] far-Infrared line survey showed that there exists a new interstellar gas phase, "diffuse photodissociation region" . Photodissociation regions in the enterface region between the CO molecular gas and the hydrogen atomic gas, and are the dominant coolant by conversion of UV and optical radiation from luminous stars into the far-infrared radiation.Therefore, the far-Infrared spectral lines are key for understanding the galactic interstellar space/matter, and are a tool for measuring the interstellar heavy element abundance. We have carried out a wide sky survey of [CII] 158 micron by a space infrared telescope ( IRTS ) and by a balloon-borne telescope ( BICE ), and [OI] 63 micron, [OIII] 52,88 micron, [CII] 158 micron, [NII] 122 micron, and [NIII] 57 micron lines by a European Infrared space observatory ( ISO ). From these data, we have shown diffuse photodissociation regions and diffuse ionization regions are important gas phases in the Galactic Interstellar space.