Gas and Metal Distributions within Simulated Disk Galaxies

TL;DR

This paper investigates the distribution and infall of gas in simulated disk galaxies, revealing insights into gas accretion patterns and age gradients that align with observations, advancing our understanding of galactic evolution.

Contribution

It provides new detailed analysis of gas infall mechanisms and age gradients in simulated galaxies, without relying on radial migration effects.

Findings

Half of the gas infall is from the corona and streams.

Gas enters the disk orthogonally, not in-plane.

Age gradients match observed features without migration.

Abstract

We highlight two research strands related to our ongoing chemodynamical Galactic Archaeology efforts: (i) the spatio-temporal infall rate of gas onto the disk, drawing analogies with the infall behaviour imposed by classical galactic chemical evolution models of inside-out disk growth; (ii) the radial age gradient predicted by spectrophometric models of disk galaxies. In relation to (i), at low-redshift, we find that half of the infall onto the disk is gas associated with the corona, while half can be associated with cooler gas streams; we also find that gas enters the disk preferentially orthogonal to the system, rather than in-plane. In relation to (ii), we recover age gradient troughs/inflections consistent with those observed in nature, without recourse to radial migrations.