The Chemical enrichment and origin of Nitrogen-Rich Galaxies at High Redshift
Speaker: Kuria Watanabe
Abstract:
Chemical properties of young galaxies are important to understand the chemical evolution in galaxy formation. We investigate the origin of abundance ratios in JWST star-forming galaxies (z ~ 4-10) by comparing chemical evolution models.
The high N/O ratio in GN-z11, CEERS_01019, and GLASS_150008 observed with JWST cannot be explained by typical chemical evolution models including AGB stars. We focus on the three candidates of rich nitrogen, the Wolf-Rayet stars (WR), supermassive stars (SMS), and tidal disruption events (TDE). We develop the chemical evolution models of three candidates. Although the Ar/O values of the high N/O galaxies are not obtained, we find that the Ar/O values are the key to distinguishing between the three models. The three models can show the high N/O values as much as the N/O values in GN-z11, CEERS_01019, and GLASS_150008. Because the time scale of high N/O is very short due to the CCSNe, the massive stars (>25 Msun) should directly collapse into black holes.