JSPAM: A restricted three-body code for simulating interacting galaxies

TL;DR

JSPAM is an updated restricted three-body simulation code that efficiently models interacting galaxies, incorporating new potentials and dynamical friction to better approximate more complex n-body results, and is publicly available.

Contribution

The paper introduces an improved version of the JSPAM code with enhanced modeling features for galaxy interactions, bridging the gap between simple restricted models and complex n-body simulations.

Findings

Updated code with alternative potential and dynamical friction

Better approximation of n-body simulation results

Public release under open-source license

Abstract

Restricted three-body codes have a proven ability to recreate much of the disturbed morphology of actual interacting galaxies. As more sophisticated n-body models were developed and computer speed increased, restricted three-body codes fell out of favor. However, their supporting role for performing wide searches of parameter space when fitting orbits to real systems demonstrates a continuing need for their use. Here we present the model and algorithm used in the JSPAM code. A precursor of this code was originally described in 1990, and was called SPAM. We have recently updated the software with an alternate potential and a treatment of dynamical friction to more closely mimic the results from n-body tree codes. The code is released publicly for use under the terms of the Academic Free License (AFL) v.3.0 and has been added to the Astrophysics Source Code Library.