Simulating Sinking Satellites with SUPERBOX-10

TL;DR

SUPERBOX-10 enhances galaxy simulation accuracy and efficiency by improving grid resolution, parallelising FFT computations, and effectively modeling satellite interactions and their impact on galactic structures.

Contribution

It introduces a parallelised version of SUPERBOX-10 with flattened grids, improving resolution and computational speed for galaxy simulations.

Findings

Flattened grids reduce numerical heating.

Satellites on low-eccentricity, low-inclination orbits heat the galactic disc.

Most satellite energy and angular momentum transfer to the halo.

Abstract

SUPERBOX-10 is the successor of SUPERBOX, a particle-mesh code where additional grids and sub-grids are applied to regions of high particle density. Previous limitations have been solved. For instance, the vertical resolution is improved considerably when flattened grids are used. Since the computationally most intensive part is the Fast Fourier Transform, we introduce a parallelised version using the library FFTW, resulting in a speed-up of a few. The new features are tested using a galaxy model consisting of an exponential disc, a bulge and a dark matter halo. We demonstrate that the use of flattened grids efficiently reduces numerical heating. We simulate the merging of disc-bulge-halo galaxies with small spherical satellites. As a result, satellites on orbits with both low eccentricity and inclination heat the disc most efficiently. Moreover, we find that most of the satellite's energy and angular momentum is transfered to the halo.