Disk-Halo Interplay in Galaxy Evolution

TL;DR

This paper reviews the complex interactions between galactic disks and halos, focusing on resonant interactions, the impact of gas, and how chaos influences galaxy structure during formation.

Contribution

It provides new insights into how triaxial dark matter halos evolve and how chaos affects disk-halo interactions in galaxy evolution models.

Findings

Triaxiality results from mergers and radial orbit instability.

Chaos dampens initial bar formation and reduces halo prolateness.

Gravitational quadrupole interactions trigger chaos in galaxy systems.

Abstract

Some aspects of disk-halo interactions for models of in and out of equilibrium disk galaxies are reviewed. Specifically, we focus on disk-halo resonant interaction without and in the presence of a gas component. Another issue is the disk growth within an assembling triaxial dark matter halo. We argue that while the triaxiality is the result of the merger process and the radial orbit instability, it is the developing chaos that damps the first generation of bars and washes out the halo prolateness. This chaos is triggered by the gravitational quadrupole interaction(s) in the system and supported by a number of other processes which are characteristic of baryons.