Unveiling the nature of the "Green Pea" galaxies

TL;DR

This paper reviews recent findings on the chemical composition of Green Pea galaxies, highlighting their low metallicity, high N/O ratios, and potential evolutionary processes involving gas inflow and stellar feedback.

Contribution

It provides a comprehensive review of the chemical abundances and evolutionary implications of Green Pea galaxies, emphasizing their unique properties and possible transient starburst phase.

Findings

Green Pea galaxies are metal-poor with high N/O ratios.

They may be undergoing a short, extreme evolutionary phase.

Gas inflow and stellar feedback are key drivers of their starburst activity.

Abstract

We review recent results on the oxygen and nitrogen chemical abundances in extremely compact, low-mass starburst galaxies at redshifts between 0.1-0.3 recently named to as "Green Pea" galaxies. These galaxies are genuine metal-poor galaxies ($\sim$ one fifth solar) with N/O ratios unusually high for galaxies of the same metallicity. In combination with their known general properties, i.e., size, stellar mass and star-formation rate, these findings suggest that these objects could be experiencing a short and extreme phase in their evolution. The possible action of both recent and massive inflow of gas, as well as stellar feedback mechanisms are discussed here as main drivers of the starburst activity and their oxygen and nitrogen abundances.