BibTeX

@article{2507.10667v1,
Author        = {Richard A. N. Brooks and Jason L. Sanders and Adam M. Dillamore and Nicolás Garavito-Camargo and Adrian M. Price-Whelan},
Title         = {A Simulation Based Inference Approach to the Dynamics of the MW-LMC
  System -- Validation},
Eprint        = {2507.10667v1},
ArchivePrefix = {arXiv},
PrimaryClass  = {astro-ph.GA},
Abstract      = {The infall of the LMC into the Milky Way (MW) has generated dynamical
disequilibrium throughout the MW. The interaction has displaced the MW's centre
of mass, manifesting as an apparent 'reflex motion' in velocities of outer halo
stars. Often, expensive high fidelity MW--LMC simulations are required to model
these effects, though the range of model parameter spaces can be large and
complex. We investigate the ability of lower fidelity, rigid MW-LMC simulations
to reliably infer the model parameters of higher fidelity N-body and
hydrodynamical cosmological zoom-in MW--LMC simulations using a
Simulation-Based Inference (SBI) approach. We produce and release a set of
128,000 MW--LMC rigid potentials, with stellar haloes evolved to present-day,
each adopting a unique combination of model parameters including the MW mass,
the LMC mass and the dynamical friction strength. For these simulation
parameters, we use SBI to find their posterior distributions. We find that our
SBI framework trained on rigid MW--LMC simulations is able to correctly infer
the true simulation LMC mass within a $1\sigma$ confidence interval from both
N-body and cosmological simulations when knowledge of the induced MW reflex
motion is provided as data. This motivates future applications of the presented
SBI framework to observational data, which will help constrain both MW and LMC
properties, as well as the dynamics of the MW's reflex motion.},
Year          = {2025},
Month         = {Jul},
Url           = {http://arxiv.org/abs/2507.10667v1},
File          = {2507.10667v1.pdf}
}