13mm低温制冷谱线接收系统和星际水分子观测研究

为了开拓短厘米波单天线星际分子的观测和研究，在乌鲁木齐天文站２５ｍ射电望远镜１３ｍｍ低温制冷接收机的基础上，配置了声表面波频谱仪和谱线数据采集系统，组成了１３ｍｍ低温致冷谱线接收机．接收机前端是一个工作在低温２０Ｋ的低噪声放大器，本振是２２ＧＨｚ的锁相源．接收机的平均噪声温度为５０Ｋ．后端是一个宽带的（４０ＭＨｚ）高分辨率（４０ｋＨｚ）的声表波频谱仪．利用这套系统观测了一批已知的水脉泽源，观测系统正常，结果合理．观测结果表明，乌鲁木齐天文站良好的站址和２５ｍ射电望远镜给厘米波段星际分子谱线观测提供了一个很好的条件．

13mm CRYOGENICALLY COOLED SYSTEM AND OBSERVATIONS FOR INTERSTELLAR MOLECULES

For the spectral line observations in short centimeter wavelength region with a single dish, a SAW(surface acoustic wave) spectrometer has been installed on the Urumqi 25m radio telescope. Together with a 13mm cryogenically cooled receiver, an analytical system of spectrum has been built with low noise temperature. The front end is a low noise amplifier operating at the temperature of 20K and the PLO uses a 22GHz phase locked oscillator. An average noise temperature of 50K for this receiver system was measured. The back end is a SAW spectrometer with wide band of 40MHz and frequency resolution of 40kHz. Many known H 2O maser sources were observed with reasonable results. The site and facilities at Urumqi Astronomical Station provide excellent conditions for the spectral line observations in centimeter wavelength region.