Grommet: an N-body code for high-resolution simulations of individual galaxies

Abstract

This paper presents a fast, economical particle-multiple-mesh N-body code optimized for large-N modelling of collisionless dynamical processes, such as black-hole wandering or bar-halo interactions, occurring within isolated galaxies. The code has been specially designed to conserve linear momentum. Despite this, it also has variable softening and an efficient block-timestep scheme: the force between any pair of particles is calculated using the finest mesh that encloses them both (respecting Newton's third law) and is updated only on the longest timestep of the two (which conserves momentum). For realistic galaxy models with N > 10^6, it is faster than the fastest comparable momentum-conserving tree code by a factor ranging from ~2 (using single timesteps) to ~10 (multiple timesteps in a concentrated galaxy).

arXiv comment10 pages, 7 figures. Simplified integrator updated to match published version

References in corpus (9)

• Adaptive Refinement Tree - a new high-resolution N-body code for cosmological simulations
• Sinking Satellites and the Heating of Galaxy Discs
• A Hierarchical O(N) Force Calculation Algorithm
• MLAPM - a C code for cosmological simulations
• Bar-Induced Evolution of Dark Matter Cusps
• Halo evolution in the presence of a disc bar
• An optimum time-stepping scheme for N-body simulations
• Models of Galaxies with Central Black Holes: Simulation Methods
• An adaptive hierarchical particle-mesh code with isolated boundary conditions

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• Multi-mass schemes for collisionless N-body simulations
• A Fast Poisson Solver of Second-Order Accuracy for Isolated Systems in Three-Dimensional Cartesian and Cylindrical Coordinates
• Hierarchical Particle-Mesh: an FFT-accelerated Fast Multipole Method
• On the long-term evolution of razor-thin galactic discs: Balescu-Lenard prediction and perspectives