Effective N-body models of composite collisionless stellar systems

Abstract

Gas-poor galaxies can be modelled as composite collisionless stellar systems, with a dark matter halo and one or more stellar components, representing different stellar populations. The dynamical evolution of such composite systems is often studied with numerical N-body simulations, whose initial conditions typically require realizations with particles of stationary galaxy models. We present a novel method to conceive these N-body realizations, which allows one to exploit at best a collisionless N-body simulation that follows their evolution. The method is based on the use of an effective N-body model of a composite system, which is in fact realized as a one-component system of particles that is interpreted a posteriori as a multi-component system, by assigning in post-processing fractions of each particle's mass to different components. Examples of astrophysical applications are N-body simulations that aim to reproduce the observed properties of interacting galaxies, satellite galaxies and stellar streams. As a case study we apply our method to an N-body simulation of tidal stripping of a two-component (dark matter and stars) satellite dwarf galaxy orbiting in the gravitational potential of the Milky Way.

arXiv comment10 pages, 9 figures, accepted for publication in MNRAS. Figures 3, 7 and 9 illustrate the method applied to tidal streams

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Cited by in corpus (4)

• The Contribution of In-situ and Ex-situ Star Formation in Early-Type Galaxies: MaNGA versus IllustrisTNG
• Multiple stellar population mass loss in massive Galactic globular clusters
• Tidal mass loss in the Fornax dwarf spheroidal galaxy through N-body simulations with Gaia DR3-based orbits
• Efficiency of parallel computations of gravitational forces by TreeCode method in N-body models