Measuring the Expansion or Contraction of Galaxies

TL;DR

This paper explores how galaxies expand or contract due to mass loss or accretion, proposing that stellar radial migration can be observed with future high-resolution telescopes, revealing galaxy evolution dynamics.

Contribution

It introduces a method to measure galaxy size changes by analyzing stellar radial migration caused by mass loss or accretion, linking observable stellar movements to galaxy evolution.

Findings

Radial migration of stars can indicate galaxy expansion or contraction.

High-resolution spectrographs could detect these stellar movements.

Accretion in dense environments may cause inward stellar migration.

Abstract

Galaxies lose mass as a result of their luminosity or gaseous outflows. I calculate the resulting radial migration of stars outwards and show that it could potentially be measured with high resolution spectrographs on the next generation of large telescopes. Substantial accretion of matter in dense cosmic environments could trigger inward stellar migration that would be even more easily measurable.