The Influence of Radial Stellar Migration on the Chemical Evolution of the Milky Way

TL;DR

This study models how radial stellar migration affects the Milky Way's chemical evolution, revealing it influences metallicity distributions and scatters local stellar abundances without significantly flattening overall abundance gradients.

Contribution

It introduces an analytical model of stellar migration integrated with chemical evolution, showing its effects on metallicity distributions and abundance gradients in the Milky Way.

Findings

Migration narrows the G-dwarf metallicity distribution.

It scatters local stellar abundances without flattening gradients.

Older stars have flatter abundance gradients.

Abstract

Stellar migration is an important dynamical process in Galactic disk. Here we model the radial stellar migration in the Galactic disk with an analytical method, then add it to detailed Galactic chemical evolution model to study the influence of radial stellar migration on the chemical evolution of the Milky Way, especially for the abundance gradients. We found that the radial stellar migration in the Galactic disk can make the profile of the G-dwarf metallicity distribution of the solar neighborhood taller and narrower, thus it becomes another solution to the "G-dwarf problem". It can also scatter the age-metallicity relation. However, after the migration, the abundance distributions along the Galactic radius don't change much, namely the abundance gradients would not be flattened by the radial stellar migration, which is different from the predictions of many theoretical works. But it can flatten the radial gradients of the mean chemical abundance of stars, and older stars possess flatter abundance gradients than younger stars. The most significant effect of the radial stellar migration on the chemical abundance is that at a position it scatters the abundance of stars there from a relatively concentrated value to a range.