Measuring bar pattern speeds from single simulation snapshots

TL;DR

This paper introduces an unbiased, precise method to measure the orientation angle and pattern speed of barred galaxies from single simulation snapshots, with potential to determine rotation vectors.

Contribution

The authors present a novel method that accurately measures bar pattern speeds and orientations from single snapshots, improving upon previous techniques.

Findings

Method is unbiased and precise

Can determine rotation axis and rate

Provides open-source code for implementation

Abstract

We describe methods to measure simultaneously the orientation angle $\psi$ and pattern speed $\Omega$ from single snapshots of simulated barred galaxies. Unlike previous attempts, our approach is unbiased, precise, and consistent in the sense that $\psi=\int\Omega\mathrm{d}t$. It can be extended to obtain the rate and axis of rotation, i.e. the vector $\boldsymbol{\Omega}$. We provide computer code implementing our method.