Book contents
- Frontmatter
- Contents
- Preface
- 1 The N-body problem
- 2 Predictor–corrector methods
- 3 Neighbour treatments
- 4 Two-body regularization
- 5 Multiple regularization
- 6 Tree codes
- 7 Program organization
- 8 Initial setup
- 9 Decision-making
- 10 Neighbour schemes
- 11 Two-body algorithms
- 12 Chain procedures
- 13 Accuracy and performance
- 14 Practical aspects
- 15 Star clusters
- 16 Galaxies
- 17 Planetary systems
- 18 Small-N experiments
- Appendix A Global regularization algorithms
- Appendix B Chain algorithms
- Appendix C Higher-order systems
- Appendix D Practical algorithms
- Appendix E KS procedures with GRAPE
- Appendix F Alternative simulation method
- Appendix G Table of symbols
- Appendix H Hermite integration method
- References
- Index
15 - Star clusters
Published online by Cambridge University Press: 18 August 2009
- Frontmatter
- Contents
- Preface
- 1 The N-body problem
- 2 Predictor–corrector methods
- 3 Neighbour treatments
- 4 Two-body regularization
- 5 Multiple regularization
- 6 Tree codes
- 7 Program organization
- 8 Initial setup
- 9 Decision-making
- 10 Neighbour schemes
- 11 Two-body algorithms
- 12 Chain procedures
- 13 Accuracy and performance
- 14 Practical aspects
- 15 Star clusters
- 16 Galaxies
- 17 Planetary systems
- 18 Small-N experiments
- Appendix A Global regularization algorithms
- Appendix B Chain algorithms
- Appendix C Higher-order systems
- Appendix D Practical algorithms
- Appendix E KS procedures with GRAPE
- Appendix F Alternative simulation method
- Appendix G Table of symbols
- Appendix H Hermite integration method
- References
- Index
Summary
Introduction
Simulating star clusters by direct N-body integrations is the equivalent of scaling mountains the hard way. At any time the maximum particle number depends on hardware and is therefore limited by technology. Some of the methods that have been described in this book are ideally suited to studying the classical point-mass problem. In addition, a wide variety of astrophysical processes can be included for realistic modelling of actual clusters. Recently the simulations have been devoted to systems with up to N ≃ 104 particles which includes rich open clusters. However, with the construction of the GRAPE-6 special-purpose computer we are now able to investigate small globular clusters as observed in the Large Magellanic Cloud (LMC) [Elson et al., 1998].
In the following we concentrate on various aspects of star cluster simulations not covered in earlier chapters. We first describe algorithms for determining the core radius and density centre which are useful tools for data analysis. For historical reasons, idealized models (i.e. isolated systems) are also considered, particularly because of their relevance for more approximate methods. After further discussions of the IMF, we return to the subject of assigning primordial binaries and illustrate their importance by some general results. External effects due to the tidal field and interstellar clouds form an important ingredient in star cluster modelling even though the latter are rarely studied. Algorithms for combining stellar evolution with the dynamical treatment have been outlined previously.
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- Chapter
- Information
- Gravitational N-Body SimulationsTools and Algorithms, pp. 264 - 296Publisher: Cambridge University PressPrint publication year: 2003