Origin of nitrogen enhancement in early galaxies

Determine the physical mechanism responsible for nitrogen enhancement in a subset of early galaxies, including whether very massive-star winds, supermassive stars, or alternative processes dominate.

Background

GN-z11 and several other high-redshift galaxies show strong nitrogen emission and enhanced N/O ratios. The paper considers enrichment by winds from very massive or Wolf–Rayet-like stars, luminous-blue-variable-like eruptions, supermassive stars, and other mechanisms. Although the observed broad N IV] component provides evidence about the relevant stellar or nuclear environments, the enrichment mechanism itself is not established.