Connecting high-redshift galaxy populations through observations of local Damped Lyman Alpha dwarf galaxies

TL;DR

This study analyzes a local dwarf galaxy that produces a Damped Lyman Alpha system, providing insights into high-redshift galaxy populations by comparing chemical abundances from emission and absorption data.

Contribution

It presents the first comparison of chemical abundances in a Damped Lyman Alpha galaxy using both emission and absorption diagnostics, linking local and high-redshift galaxy observations.

Findings

Abundances from emission and absorption agree within uncertainties.

The galaxy provides a local analog for high-redshift Damped Lyman Alpha systems.

A catalog of dwarf galaxy-QSO projections is provided for future research.

Abstract

I report on observations of the z=0.01 dwarf galaxy SBS1543+593 which is projected onto the background QSO HS1543+5921. As a star-forming galaxy first noted in emission, this dwarf is playing a pivotal role in our understanding of high-redshift galaxy populations, because it also gives rise to a Damped Lyman Alpha system. This enabled us to analyze, for the first time, the chemical abundance of $\alpha$ elements in a Damped Lyman Alpha galaxy using both, emission and absorption diagnostics. We find that the abundances agree with one another within the observational uncertainties. I discuss the implications of this result for the interpretation of high-redshift galaxy observations. A catalog of dwarf-galaxy--QSO projections culled from the Sloan Digital Sky Survey is provided to stimulate future work.