Impacts of stellar wind and supernovae on star cluster formation: Origins of extremely high N/O ratios and multiple stellar populations.

This article focuses on the metal enrichment processes from stellar winds and supernovae (SNe) in low-metallicity clouds during massive star cluster formation, investigated through three-dimensional radiation hydrodynamics simulations. It finds that nitrogen enrichment, primarily from Wolf–Rayet (WR) stellar winds, accumulates in sufficiently massive (≥10^6 solar masses) and compact star clusters before SNe occur, producing nitrogen-enhanced gas and subsequent star formation with elevated nitrogen-to-oxygen ([N/O]) ratios comparable to those observed in certain high-redshift galaxies. The study shows that if star formation lasts longer than the WR phase but shorter than the SN timescale (~10 Myr), a significant fraction of stars form from nitrogen-enriched gas, whereas longer durations lead to oxygen enrichment from SNe and lower [N/O] ratios. These results suggest that massive, dense star-forming clumps observed in early galaxies by JWST are plausible sites for globular cluster formation with multiple stellar populations, linking early starburst activity to observed chemical abundance patterns.