MSTAR -- a fast parallelised algorithmically regularised integrator with minimum spanning tree coordinates
| Autor: | Rantala, Antti, Pihajoki, Pauli, Mannerkoski, Matias, Johansson, Peter H., Naab, Thorsten |
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| Rok vydání: | 2020 |
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| Zdroj: | Monthly Notices of the Royal Astronomical Society, Volume 492, Issue 3, March 2020, Pages 4131-4148 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1093/mnras/staa084 |
| Popis: | We present the novel algorithmically regularised integration method MSTAR for high accuracy ($|\Delta E/E| \gtrsim 10^{-14}$) integrations of N-body systems using minimum spanning tree coordinates. The two-fold parallelisation of the $\mathcal{O}(N_\mathrm{part}^2)$ force loops and the substep divisions of the extrapolation method allows for a parallel scaling up to $N_\mathrm{CPU} = 0.2 \times N_\mathrm{part}$. The efficient parallel scaling of MSTAR makes the accurate integration of much larger particle numbers possible compared to the traditional algorithmic regularisation chain (AR-CHAIN) methods, e.g. $N_\mathrm{part} = 5000$ particles on $400$ CPUs for $1$ Gyr in a few weeks of wall-clock time. We present applications of MSTAR on few particle systems, studying the Kozai mechanism and N-body systems like star clusters with up to $N_\mathrm{part} =10^4$ particles. Combined with a tree or a fast multipole based integrator the high performance of MSTAR removes a major computational bottleneck in simulations with regularised subsystems. It will enable the next generation galactic-scale simulations with up to $10^9$ stellar particles (e.g. $m_\star = 100 M_\odot$ for a $M_\star = 10^{11} M_\odot$ galaxy) including accurate collisional dynamics in the vicinity of nuclear supermassive black holes. Comment: 20 pages, 16 figures, accepted for publication in MNRAS |
| Databáze: | arXiv |
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