Nitrogen Production in Starburst Galaxies Detected by GALEX

TL;DR

This study analyzes nitrogen production in starburst galaxies using UV data from GALEX and spectroscopic data from SDSS, revealing differences in nitrogen-to-oxygen ratios related to star formation activity.

Contribution

It combines UV and optical data to derive gas-phase abundances and star formation histories, providing new insights into nitrogen production in starburst galaxies.

Findings

Galaxies with higher specific star formation rates have lower N/O ratios.

The study compares multiple diagnostics for oxygen abundance.

Starburst activity influences nitrogen enrichment in galaxies.

Abstract

We investigate the production of nitrogen in star forming galaxies with ultraviolet (UV) radiation detected by the Galaxy Evolution Explorer Satellite (GALEX). We use a sample of 8,745 GALEX emission line galaxies matched to the Sloan Digital Sky Survey (SDSS) spectroscopic sample. We derive both gas-phase oxygen and nitrogen abundances for the sample, and apply stellar population synthesis models to derive stellar masses and star formation histories of the galaxies. We compare oxygen abundances derived using three different diagnostics. We derive the specific star formation rates of the galaxies by modeling the 7-band GALEX+SDSS photometry. We find that galaxies that have log SFR/M$_*$ > -10.0 typically have values of log N/O ~0.05 dex less than galaxies with log SFR/M$_*$ < -10.0 and similar oxygen abundances.