Sub-galactic scaling relations with T$_{\rm e}$-based metallicity of low metallicity regions in galaxies: metal-poor gas inflow may have important effects?

TL;DR

This study investigates low-metallicity regions in galaxies using T$_{ m e}$-based metallicity measurements, revealing that metal-poor gas inflow during interactions influences galaxy evolution, star formation, and metallicity scaling relations.

Contribution

It provides new insights into how metal-poor gas inflow affects galaxy scaling relations and star formation in low-metallicity regions, especially during interactions.

Findings

Low-metallicity regions have higher star formation rates.

Galaxies with low-metallicity regions are often mergers.

Metal-poor gas inflow may dilute interstellar medium during interactions.

Abstract

The scaling relationship is a fundamental probe of the evolution of galaxies. Using the integral field spectroscopic data from the Mapping Nearby Galaxies at Apache Point Observatory survey, we select 1698 spaxels with significant detection of the auroral emission line \oiii$\lambda$4363 from 52 galaxies to investigate the scaling relationships at the low-metallicity end. We find that our sample's star formation rate is higher and its metallicity is lower in the scaling relationship than the star-forming sequence after removing the contribution of the Fundamental Metallicity Relation.We also find that the stellar ages of our sample are younger ($<$ 1 Gyr) and the stellar metallicities are also lower. Morphological parameters from Deep Learning catalog indicate that our galaxies are more likely to be merger. These results suggest that their low metallicity regions may be related to interaction, the inflow of metal-poor gas may dilute the interstellar medium and form new metal-poor stars in these galaxies during interaction.