银河系质量的多途径测定  

Approaches for Measurements of the Mass of the Milky Way Galaxy

作　　者：赵君亮[1,2] 

机构地区：[1]中国科学院上海天文台,上海200030 [2]上海师范大学,上海200233

出　　处：《天文学进展》2015年第2期175-187,共13页Progress In Astronomy

基　　金：国家自然科学基金(11373054);中国科学院战略性先导科技专项B类(XDB09010100)

摘　　要：对测定银河系质量的一些主要方法及若干重要相关问题做了简要介绍,包括运动学方法(含自转曲线法)、伴天体的潮汐半径、逃逸速度法和计时推理法等。给出近40年来较有代表性的银河系质量的实测结果,并加以比较和讨论。迄今为止银河系质量的测定值仍有相当大的不确定性,未来的空间观测资料有望对此做出明显的改进。As one of the important parameters of the Milky Way Galaxy, the Galactic mass has been determined or estimated in many different ways since 1920s, including kinematics of tracers, tidal radius of both globular clusters and dwarf satellite galaxies of the Galaxy, local escape velocity, timing argument theory, etc. Different kinds of tracers can be used for estimating the Galactic mass, including globular clusters, satellite galaxies and some other bright halo population objects, such as field horizontal branch stars, RR Lyraes variables, red giant stars, etc. In order to measure the whole dynamical mass of the galaxy, tracers with galactocentric distances as far as possible should be used. In order to determine the Galactic mass based on kinematics of tracers, it is necessary to gain space velocities of the tracers, both line-of-sight velocities and proper motions （transverse velocities）. However, in earlier time it was very dimcult and even impossible to measure proper motions of tracers because they are far away from us. In this case, only observational data which can be used for mass determination are line-of-sight velocities of tracers, and some theoretical assumptions for tracers＇ orbits are necessary to be introduced. As VLBI and space techniques become applicable to astrometry, proper motion data have been available for some satellite galaxies to estimate the Galactic mass. Besides the above method, some other approaches can also be used for estimation of the Galactic mass. （1） There is a relation among the tidal （limiting） radius of a satellite, its mass and Galactocentric distance and the Galactic mass, which can be used to estimate the Galactic mass. （2） In the solar neighborhood, there is a simple relation between the Galactic mass and the local escape velocity, which has been used for determination of the Galactic mass. （3） If a pair of galaxies, such as the Galaxy and a dwarf satellite, is well represented by point masses and isolated, their total mass may be estimated by mea

关 键 词：银河系质量 暗物质 自转曲线 潮汐半径 逃逸速度 计时推理 自行 

分 类 号：P156.4[天文地球—天文学]