New Astronomy, 5, 305-326 (2000/September-0)
SUPERBOX - an efficient code for collisionless galactic dynamics.
FELLHAUER M., KROUPA P., BAUMGARDT H., BIEN R., BOILY C.M., SPURZEM R. and WASSMER N.
Abstract (from CDS):
We present Superbox, a particle-mesh code with high resolution sub-grids and an NGP (nearest grid point) force-calculation scheme based on the second derivatives of the potential. Superbox implements a fast low-storage FFT-algorithm, giving the possibility to work with millions of particles on desk-top computers. Test calculations show energy and angular momentum conservation to one part in 10^5 per crossing-time. The effects of grid and numerical relaxation remain negligible, even when these calculations cover a Hubble-time of evolution. As the sub-grids follow the trajectories of individual galaxies, the code allows a highly resolved treatment of interactions in clusters of galaxies, such as high-velocity encounters between elliptical galaxies and the tidal disruption of dwarf galaxies. Excellent agreement is obtained in a comparison with a direct-summation N-body code running on special-purpose Grape 3 hardware. The orbital decay of satellite galaxies due to dynamical friction obtained with Superbox agrees with Chandrasekhar's treatment when the Coulomb logarithm lnLambda ~= 1.5.