ESO 546-G34: The most metal poor LSB galaxy?

TL;DR

This study re-analyzed spectroscopic data of low surface brightness galaxies, identifying ESO 546-G34 as potentially the most metal-poor LSB galaxy, and suggests an evolutionary link with blue compact galaxies based on metallicity-luminosity deviations.

Contribution

It provides the first identification of a potentially extremely metal-poor LSB galaxy and explores its implications for galaxy evolution and the luminosity-metallicity relation.

Findings

ESO 546-G34 may be the most metal-poor LSB galaxy in the local Universe.

Blue metal-poor LSBGs and BCGs deviate from the standard luminosity-metallicity relation.

Evidence suggests an evolutionary connection between LSBGs and BCGs.

Abstract

We present a re-analysis of spectroscopic data for 23 HII-regions in 12 blue, metal-poor low surface brightness galaxies (LSBGs) taking advantage of recent developments in calibrating strong-line methods. In doing so we have identified a galaxy (ESO 546-G34) which may be the most metal-poor LSB galaxy found in the local Universe. Furthermore, we see evidence that blue metal-poor LSBGs, together with blue compact galaxies (BCGs) and many other HII galaxies, fall outside the regular luminosity-metallicity relation. This suggests there might be an evolutionary connection between LSBGs and BCGs. In such case, several very metal-poor LSBGs should exist in the local Universe.