Clues to Radial Migration from the Properties of Outer Disks

TL;DR

This paper reviews observational evidence linking surface brightness profile breaks in galaxy outer disks to radial migration, highlighting their importance in understanding galaxy disk formation.

Contribution

It synthesizes current observational data supporting the role of radial migration in shaping outer disk properties.

Findings

Surface brightness breaks are common in galaxy disks.

Radial migration is a plausible explanation for these breaks.

Observational evidence aligns with theoretical models of disk evolution.

Abstract

The outer disks of galaxies present a unique laboratory for studying the process of disk formation. A considerable fraction of observed disks exhibit a break in their surface brightness profiles. The ubiquity of these features points to a crucial aspect of disk formation which must be explained. Recent theoretical work suggests that such breaks are related to significant amounts of radial migration. We discuss the current observational evidence which supports this picture.