Abundance evolution of intermediate mass elements (C to Zn) in the Milky Way halo and disk

TL;DR

This study models the evolution of intermediate mass elements from C to Zn in the Milky Way's halo and disk, comparing predictions with observations to evaluate stellar yields and element behavior.

Contribution

It provides a consistent galactic evolution model for halo and disk, analyzing element abundance evolution with metallicity-dependent yields and critically assessing stellar nucleosynthesis data.

Findings

Models match main observational constraints

Identifies successes and shortcomings of stellar yields

Discusses potential explanations for oxygen behavior

Abstract

We present a comprehensive study of the evolution of the abundances of intermediate mass elements, from C to Zn, in the Milky Way halo and in the local disk. We use a consistent model to describe the evolution of those two galactic subsystems. The halo and the disk are assumed to evolve independently, both starting with gas of primordial composition, and in different ways: strong outflow is assumed to take place during the $\sim$1 Gyr of the halo formation, while the disk is built by slowly infalling gas. This description of the halo+disk evolution can correctly account for the main observational constraints (at least in the framework of simple models of galactic chemical evolution). We utilise then metallicity dependant yields to study the evolution of all elements from C and Zn. Comparing our results to an extensive body of observational data (including very recent ones), we are able to make a critical analysis of the successes and shortcomings of current yields of massive stars. Finally, we discuss qualitatively some possible ways to interpret the recent data on oxygen vs iron, which suggest that oxygen behaves differently from the other alpha-elements.