【摘要】 本文对于物质密度沿z方向指数衰减的轴对称盘状星系模型,忽略恒星本动,讨论了物质在星系盘面的投影面密度同星系旋转曲线的关系,得出了对于无限薄盘的Toomre模型的改正公式。结果表明,考虑了星系厚度以后,物质分布比无限薄盘模型更加向中心集中。对银河系中心部分,投影面密度值比Toomre公式给出的密度值约高9%。更多还原

【Abstract】 Neglecting peculiar motion of stars, the relation between projected surface density and rotation curve of axisymmetrical galaxies in which the distribution of matter along z-axis is assumed to be in proportion as e^-a|x| is investigated. Modified formu-lae of Toomre’s model for highly flattened galaxies are obtained. It is shown that on considering the thickness of galaxies, the distribution of matter will concentrate more to the centre of galaxies than Toomre’s model. For central part of the Galaxy, the projected surface density has increased about 9% more than that given by Too-mre’s model.更多还原