A MUSE/VLT spatially resolved study of the emission structure of Green Pea galaxies

TL;DR

This study uses integral field spectroscopy to spatially resolve emission structures in Green Pea galaxies, revealing how star formation influences ionization and chemical properties, thus shedding light on early galaxy evolution.

Contribution

It provides the first detailed spatially resolved emission maps of Green Pea galaxies, linking starburst regions to ionization and metallicity variations.

Findings

Starburst regions correlate with high excitation areas.

Outer regions contain low brightness ionized gas.

High-ionizing lines are present in some galaxies with intense star formation.

Abstract

Green Pea galaxies are remarkable for their intense star formation and serve as a window into the early universe. In our study, we used integral field spectroscopy to examine 24 of these galaxies in the optical spectrum. We focused on the interaction between their ionized interstellar medium and the star formation processes within them. Our research generated spatial maps of emission lines and other properties like ionization structures and chemical conditions. These maps showed that areas with higher levels of excitation are usually located where starbursts are occurring. Continuum maps displayed more intricate structures than emission line maps and hinted at low brightness ionized gas in the galaxies' outer regions. We also analyzed integrated spectra from selected areas within these galaxies to derive physical properties like electron densities and temperatures. In some galaxies, we were able to determine metallicity levels. Our observations revealed the presence of high-ionizing lines in three galaxies, two of which had extremely high rates of star formation. Our findings provide valuable insights into the properties and star-forming processes in Green Pea galaxies, contributing to our broader understanding of galactic evolution in the early universe.