A flexible method to evolve collisional systems and their tidal debris in external potentials

TL;DR

This paper presents a versatile numerical method for simulating the evolution of collisional systems and their tidal debris within complex, time-varying external gravitational potentials, enhancing the modeling of star clusters and their tidal tails.

Contribution

The authors develop a differential technique to accurately evaluate tidal accelerations and their derivatives, integrated into the nbody6 code, enabling detailed studies of star clusters in evolving external fields.

Findings

Method successfully models star clusters in complex potentials

Allows simulation of tidal tails in multi-component systems

Implemented in widely-used nbody6 code

Abstract

We introduce a numerical method to integrate tidal effects on collisional systems, using any definition of the external potential as a function of space and time. Rather than using a linearisation of the tidal field, this new method follows a differential technique to numerically evaluate the tidal acceleration and its time derivative. Theses are then used to integrate the motions of the components of the collisional systems, like stars in star clusters, using a predictor-corrector scheme. The versatility of this approach allows the study of star clusters, including their tidal tails, in complex, multi-components, time-evolving external potentials. The method is implemented in the code nbody6 (Aarseth 2003).