A Large Scale Survey of the Subnmillimeter-wave Emission of Atomic Carbon at Northrn Chile

该项目的主要目的是利用在Pampa la Bola（alt. 4800米）。为此，我们首先研制了一种紧凑的亚毫米波接收机，采用GN 2级制冷机。接收机噪声温度达到200 K。利用这台望远镜，我们在项目期间进行了三次测试观测（2001年3月、2001年9月和2002年9月），第一次运行时，我们在运输过程中遇到了望远镜Az驱动系统的严重故障，我们只在Pampa la Bola站点确认了个别仪器的性能。在第二次运行中，我们成功地观测到了来自月球和太阳的492 GHz连续辐射，还观测到了来自高层大气的臭氧辐射。在第三次运行中，我们终于成功地检测到中性碳原子的亚毫米波线（492 GHz）的pOph分子云与该望远镜系统。此外，我们还观测到了包括NGC 6334和M17在内的几个分子云。特别是在M17中，观测到了速度宽度为40 km/s的明显的激波辐射。由于这种翼发射在空间上是扩展的，它不能归因于分子外流从原恒星在这一地区。相反，这种辐射可能代表一种尚未被认识的新型星际云。如上所述，我们已经建立了18厘米望远镜系统，并获得了具有天体物理重要性的新的科学结果。

The principal aim of this project is a large-scale survey observation of the neutral carbon atom with a new transportable 18 cm submillimeter-wave telescope operated at Pampa la Bola (alt. 4800m) in northern Chi I e. For this purpose, we have first developed a compact submillimeter-wave receiver by using a GN 2 stage refrigerator. The receiver noise temperature achieved was as low as 200 K. With this telescope, we conducted the test observations three times during the project period (March 2001, September 2001, and September 2002).In the first run, we had a serious trouble in the Az driving system of the telescope during transportation, and we only confirmed the performance of individual instruments at the Pampa la Bola site. In the second run, we successfully observed the continuum emission from the moon and the sun at 492 GHz, and also observed the ozone emission from the upper atmosphere. In the third run, we finally succeeded in detecting the submillimeter-wave line (492 GHz) of the neutral carbon atom toward the pOph molecular cloud with this telescope system. Furthermore, we observed several molecular clouds including NGC6334 and M17. Particularly awing emission with the velocity width of 40 km/s has been detected clearly in M17. Since this wing emission is spatially extended, it cannot be ascribed to the molecular outflow from protostars in this region. Rather this emission may represent a new type of interstellar clouds that has not been recognized yet.As described above, we have established the 18 cm telescope system, and have obtained new scientific results of astrophysical importance.