Chaotic Spiral Galaxies

TL;DR

This paper investigates how chaotic orbits, guided by asymptotic curves, support the spiral structure in barred spiral galaxy models, revealing their role in maintaining the galaxy's spiral arms over multiple rotations.

Contribution

It demonstrates that chaotic orbits along unstable asymptotic manifolds can support spiral structures for extended periods, with different orbits influencing different galaxy regions.

Findings

Chaotic orbits follow unstable periodic orbits initially.

Orbits support spiral structure for over 10 bar rotations.

Outer galaxy orbits diffuse outward more slowly.

Abstract

We study the role of asymptotic curves in supporting the spiral structure of a N-body model simulating a barred spiral galaxy. Chaotic orbits with initial conditions on the unstable asymptotic curves of the main unstable periodic orbits follow the shape of the periodic orbits for an initial interval of time and then they are diffused outwards supporting the spiral structure of the galaxy. Chaotic orbits having small deviations from the unstable periodic orbits, stay close and along the corresponding unstable asymptotic manifolds, supporting the spiral structure for more than 10 rotations of the bar. Chaotic orbits of different Jacobi constants support different parts of the spiral structure. We also study the diffusion rate of chaotic orbits outwards and find that chaotic orbits that support the outer parts of the galaxy are diffused outwards more slowly than the orbits supporting the inner parts of the spiral structure.