星系的恒星速度弥散度的归算方法

Methods of Recovering Stellar Velocity Dispersions of Galaxies

星系的恒星视向速度分布是星系动力学模型的重要观测约束,其特征参数包括速度弥散度、分布轮廓以及红移。这些参数对研究星系的动力学、结构和演化以及中央黑洞的质量等都具有重要的价值。该文全面总结了从星系光谱归算星系的恒星视向速度分布及其弥散度的各种方法,以及对观测和处理的一些要求。这些方法都假设星系谱线可看作是模板星光谱经多普勒位移并加宽后的线性叠加。提取尽可能多的星系内部恒星运动信息、减少模板星失配的影响、简化误差分析,是这些方法追求的目标。

The line-of-sight velocity distributions （LOSVDs）, including velocity dispersions, velocity distributions profile and redshift, are the important observational constraints in our understanding of the galactic dynamics, structures and evolution, as well as the nature of supermassive black holes in the center of galaxies. In this paper, we have given a detailed review for all the methods used for recovering LOSVDs of galaxies and the requirements for observations and data processings. Those methods are based on an assumption that a galactic spectrum can be described as if it were generated from some template stellar spectrums which are produced by doppler shifting and line broadening. The ultimate purpose of these new methods is to get galactic dynamical information from its spectrum as much as possible, to minimize the effect of template mismatching, and to simplify the error analysis.