Comparison of Convective Overshooting Models and Their Impact on Abundances from Integrated Light Spectroscopy of Young ($<$ 3 Gyr) Star Clusters

TL;DR

This study assesses how different convective overshooting models in stellar evolution affect chemical abundance measurements from integrated light spectroscopy of young star clusters, finding that models without overshooting yield more accurate results.

Contribution

It compares the impact of convective overshooting in isochrone models on Fe abundance results from integrated light spectroscopy of young clusters, providing guidance for model selection.

Findings

Isochrones without convective overshooting give more accurate Fe abundances.

Integrated light spectroscopy can test and constrain stellar evolution models.

Convective overshooting is a key parameter affecting abundance analysis accuracy.

Abstract

As part of an ongoing program to measure detailed chemical abundances in nearby galaxies, we use a sample of young to intermediate age clusters in the Large Magellanic Cloud with ages of 10 Myr to 2 Gyr to evaluate the effect of isochrone parameters, specifically core convective overshooting, on Fe abundance results from high resolution, integrated light spectroscopy. In this work we also obtain fiducial Fe abundances from high resolution spectroscopy of the cluster individual member stars. We compare the Fe abundance results for the individual stars to the results from isochrones and integrated light spectroscopy to determine whether isochrones with convective overshooting should be used in our integrated light analysis of young to intermediate age (10 Myr -3 Gyr) star clusters. We find that when using the isochrones from the Teramo group, we obtain more accurate results for young and intermediate age clusters over the entire age range when using isochrones without convective overshooting. While convective overshooting is not the only uncertain aspect of stellar evolution, it is one of the most readily parametrized ingredients in stellar evolution models, and thus important to evaluate for the specific models used in our integrated light analysis. This work demonstrates that our method for integrated light spectroscopy of star clusters can provide unique tests for future constraints on stellar evolution models of young and intermediate age clusters.