On the universality of luminosity-metallicity and mass-metallicity relations for compact star-forming galaxies at redshifts 0 < z < 3

TL;DR

This study demonstrates that the relationships between luminosity, metallicity, and stellar mass in compact star-forming galaxies are consistent across a wide redshift range, indicating universal relations from z=0 to z=3.

Contribution

It provides evidence for the universality of luminosity-metallicity and mass-metallicity relations in compact star-forming galaxies across 0 < z < 3.

Findings

Low-redshift and high-redshift galaxies follow similar relations.

Metallicity shows weak dependence on stellar mass, redshift, and star-formation rate.

Universal global relations exist for compact star-forming galaxies over the studied redshift range.

Abstract

We study relations between global characteristics of low-redshift (0 < z < 1) compact star-forming galaxies, including absolute optical magnitudes, Hbeta emission-line luminosities (or equivalently star-formation rates), stellar masses, and oxygen abundances. The sample consists of 5182 galaxies with high-excitation HII regions selected from the SDSS DR7 and SDSS/BOSS DR10 surveys adopting a criterion [OIII]4959/Hbeta > 1. These data were combined with the corresponding data for high-redshift (2 < z < 3) star-forming galaxies. We find that in all diagrams low-z and high-z star-forming galaxies are closely related indicating a very weak dependence of metallicity on stellar mass, redshift, and star-formation rate. This finding argues in favour of the universal character of the global relations for compact star-forming galaxies with high-excitation HII regions over redshifts 0 < z < 3.