Hierarchical merging and the structure of elliptical galaxies
Hierarchical merging and the structure of elliptical galaxies
复制标题
椭圆星系的层次合并和结构
DOI：
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发表时间：
1983
期刊：
影响因子：
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通讯作者：
M. Duncan
中科院分区：
文献类型：
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作者：
R. Farouki;S. Shapiro;M. Duncan
N 体模拟用于研究由分层合并产生的无碰撞自引力系统（例如星系）的全局特性之间的关系。假定质量为 M 的每个星系是由两个质量为 1/2 M 的相同前身星系通过相互穿透的抛物线相遇合并而形成的。在合并层次的各个阶段，残余星系都与其祖先星系有着强烈的同源性。结果是星系质量和中心速度色散之间的幂律关系，其指数类似于观测到的椭圆形光度-速度色散关系。由于这种关系似乎完全无标度，因此我们检查了主要由随机运动支持的其他恒星系统（球状星团和矮椭圆星系）的观测数据。讨论了分级合并已经在质量上运行了几十年的可能性（10/sup 5/<或约=M/M/sub sun/<或约=10/sup 12/）。
N-body simulations are employed to investigate relationships between the global properties of collisionless, self-gravitating systems (e.g., galaxies) that result from hierarchical merging. Each galaxy of mass M is assumed to form by the merging of two identical progenitors of mass 1/2 M from an interpenetrating parabolic encounter. The remnant galaxies depart strongly from homology with their progenitors at all stages in the merging hierarchy. A power-law relation between galaxy mass and central velocity dispersion results, with exponent similar to the observed luminosity-velocity dispersion relation for ellipticals. Since this relation appears to be entirely scale-free, we inspect observational data on other stellar systems supported primarily by random motions (globular clusters and dwarf elliptical galaxies). The possibily that hierarchical merging has operated over many decades in mass (10/sup 5/< or approx. =M/M/sub sun/ < or approx. =10/sup 12/) is discussed.