Direct collisional simulation of 10000 particles past core collapse

被引:53
作者
Spurzem, R [1 ]
Aarseth, SJ [1 ]
机构
[1] UNIV CAMBRIDGE,INST ASTRON,CAMBRIDGE CB3 0HA,ENGLAND
关键词
methods; numerical; celestial mechanics; stellar dynamics; galaxies; star clusters;
D O I
10.1093/mnras/282.1.19
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
A collisional N-body simulation using NBODY5 On a Single GRAY YMP processor is followed well into the post-collapse regime. This is presently one of the largest particle numbers of all such models published, but some data for an even larger N produced by using special-purpose computers have recently been presented. In contrast to previous ensemble-averaged N-body simulations the noise here is low enough just to compare this one single run with the expectations from statistical models based on the Fokker-Planck approximation. Agreement is as good as could be expected for the case of the evolution of the Lagrangian radii, radial and tangential velocity dispersions and various core quantities. We discuss briefly approximate models to understand the number and the energy of escapers and the question of gravothermal core oscillations; although the system exhibits postcollapse oscillations they turn out to be directly binary driven and we cannot prove the existence of a gravothermal expansion at this particle number. Finally in a detailed examination of the wandering of the density centre we find, in contrast to some previous studies, a clear long-time period of the order of approximately 14 half-mass crossing times.
引用
收藏
页码:19 / 39
页数:21
相关论文
共 50 条
[1]  
AARSETH SJ, 1974, ASTRON ASTROPHYS, V35, P237
[2]  
AARSETH SJ, 1985, MULTIPLE TIME SCALES, P378
[3]   NUMERICAL-INTEGRATION SCHEME FOR N-BODY GRAVITATIONAL PROBLEM [J].
AHMAD, A ;
COHEN, L .
JOURNAL OF COMPUTATIONAL PHYSICS, 1973, 12 (03) :389-402
[4]   A HIERARCHICAL O(N-LOG-N) FORCE-CALCULATION ALGORITHM [J].
BARNES, J ;
HUT, P .
NATURE, 1986, 324 (6096) :446-449
[5]  
BETTWIESER E, 1984, MON NOT R ASTRON SOC, V208, P493
[6]   THE ONSET OF GRAVOTHERMAL OSCILLATIONS IN GLOBULAR-CLUSTER EVOLUTION [J].
BREEDEN, JL ;
COHN, HN ;
HUT, P .
ASTROPHYSICAL JOURNAL, 1994, 421 (01) :195-205
[7]  
Brown S. D., 1992, FIELD PROGRAMMABLE G
[8]   CORE RADIUS AND DENSITY-MEASUREMENTS IN N-BODY EXPERIMENTS - CONNECTIONS WITH THEORETICAL AND OBSERVATIONAL DEFINITIONS [J].
CASERTANO, S ;
HUT, P .
ASTROPHYSICAL JOURNAL, 1985, 298 (01) :80-94
[9]   GRAVOTHERMAL OSCILLATIONS AFTER CORE COLLAPSE IN GLOBULAR-CLUSTER EVOLUTION [J].
COHN, H ;
HUT, P ;
WISE, M .
ASTROPHYSICAL JOURNAL, 1989, 342 (02) :814-822