Chemical abundance patterns in Local Group galaxies within cosmological simulations

TL;DR

This paper integrates a chemical enrichment model into cosmological simulations of Local Group galaxies, revealing how different stellar populations contribute to chemical evolution over time.

Contribution

It presents a novel implementation of chemical enrichment in cosmological simulations, linking galaxy formation history with detailed chemical evolution.

Findings

Alpha-element enrichment occurs early due to Type II supernovae.

Gradual contamination from Type Ia supernovae and AGB star winds.

Chemical evolution varies across galaxy components.

Abstract

In the context of the concordance cosmology, structure formation in the Universe is the result of the amplification, by gravitational effects, of small perturbations in the primeval density field. This results in the formation of structures known as dark matter haloes, where gas collapses and forms stars, giving birth to galaxies. Numerical simulations are an important tool in the theoretical study of galaxy formation and evolution. In the present work, we describe the implementation of a chemical enrichment model in a state-of-the-art cosmological simulation of the Local Group. The simulation includes sub-grid models for the most relevant physical processes. We analyze the chemical and morphological evolution of two galaxies with virial masses similar to that of our Milky Way. For each of the stellar components (disc, bulge and halo), we establish links between their formation history and their chemical evolution. We find that $\alpha$-element (O, Mg, Si) enrichment happens at early stages of evolution, as their main producers are short-lived stars which end their lives as type II supernova explosions. There is also a gradual contamination with the rest of the elements as type Ia supernovae and winds of stars in the asymptotic giant branch occur.