Research on Galactic dynamics with maser sources

这项研究的目的是通过高精度测量脉泽源的径向速度来研究星系的自转曲线，这是目前射电天文学技术所能提供的。高灵敏度的射电观测将基于对附近恒星的观测的位置天文学方法扩展到银河系的所有地方。我们测量了SiO源和OH/H2O脉泽源的径向速度，得到了银河系的自转曲线，阐明了气体和恒星运动的差异。我们还测试了测量附近脉泽源自行的可能性。利用JHK红外成像观测对脉泽源进行了识别：在近红外和中红外数据中精确地测量了恒星的位置，并确定了与光谱能量分布的距离。通过对这些射电和近红外观测获得的数据进行分析，我们得到了愚蠢的结果；(1)银河系外的SiO脉泽源的径向速度数据表明，银河系自转曲线在太阳附近随半径缓慢减小，富氧星和富碳星的近红外色指数具有不同的特征。(2)我们在SgrB分子云方向发现了大量的SiO脉泽源，并在近红外成像中将它们识别为恒星。在距银心1角分的范围内，我们还发现了许多SiO脉泽源。(3)分析了水脉泽斑的位置和速度数据，揭示了脉泽斑加速运动的存在，在此基础上，我们证实了用射电和红外技术相结合的方法高精度测量银河系恒星运动的可能性。

The purpose of this research was to investigate the rotation curve of the Galaxt by measuring the radial velocities of maser sources with high accuracy that is now available with techniques in radio astronomy. The high sensitivity radio observations extends the method of positional astronomy, which were based on the observations on nearby stars, to all the way in the Galaxy. We have measured radial velocities of SiO and OH/H2O masers ources, obtained the rotation curve of the Galaxy, and clarify the difference of motion between the gas and stars. We also tested a possibility of measuring proper motions of nearby maser sources. we have identified the maser sources with infrared JHK imaging observations : positions of stars were measured in an accuracy of arcsec, and determined the distances from the spectral energy distribution in the near and mid infrared data.With the analyzes of the data obtained by these radio and near-infrared observations, we have obtained the foolowing results ;(1) The radial velocity data of SiO maser sources at the outer Galaxy show that the Galactic rotation curve is slowly decreasing with radius near the solar neibourhood, and the oxygen-and carbon-rich stars have a different characteristic in the near-infrared color index.(2) We founda number of SiO maser sources in the directions of Sgr B molecular cloud and they are identified at the near-infrared imaging as stars. We also found many SiO maser sources within 1 arc minute from the Galactic center.(3) Analyzes the positional and velocity data of water maser spots revealed the presence of accelerating motion of the maser spots.Based on these observations, we have confirmed the possibility of measuring stellar motions in the Galaxy with high accuracy by the method combining the radio and infrared techniques.