# The ALPINE-CRISTAL-JWST Survey: The Fast Metal Enrichment of Massive Galaxies at z~5

**Authors:** Andreas L. Faisst, Lun-Jun Liu, Yohan Dubois, Omima Osman, Andrea Pallottini, Livia Vallini, Seiji Fujimoto, Bahram Mobasher, Wuji Wang, Yu-Heng Lin, Ricardo O. Amorín, Manuel Aravena, R. J. Assef, Andrew J. Battisti, Matthieu Béthermin, Médéric Boquien, Paolo Cassata, Elisabete da Cunha, Poulomi Dam, Gabriella de Lucia  
**arXiv:** [2510.16106](https://arxiv.org/abs/2510.16106)  
**Date:** 2025-10-17  
**Summary page:** https://www.summarizepaper.com/en/paper/2510.16106v1/

## Key points

- Study by Faisst et al. focused on stellar mass-metallicity relationship (MZR) and mass-metallicity-star formation connection (FMR) in 18 massive main-sequence galaxies at z~5 from ALPINE-CRISTAL-JWST sample.
- Metallicities determined using strong optical lines, verified through oxygen abundance measurements for five galaxies with faint auroral lines.
- Minimal evolution in MZR observed between z~5 and cosmic noon at z~2, indicating rapid metal enrichment in early galaxies.
- FMR at z=5 showed larger scatter towards lower metallicities compared to local FMR, attributed to bursty star formation, direct metal build-up, age variations, and outflow efficiencies.
- Observed MZR and FMR aligned well with cosmological simulations over three orders of stellar mass, but some simulations underestimated metal enrichment at lower masses due to overly efficient outflows.
- ALPINE-CRISTAL-JWST galaxies likely integrated into current FMR around z~10 and expected to evolve into massive galaxies with super-solar metallicities by z=0.
- Study provides insights into fast metal enrichment processes in massive galaxies at high redshifts and highlights complex interplay between star formation, metal production, and galaxy evolution in the early universe.

## Summary

In the study conducted by Faisst et al., the relationship between stellar mass and metallicity (known as the MZR) and the connection between mass, metallicity, and star formation (known as the FMR or "fundamental metallicity relation") were investigated for 18 massive main-sequence galaxies at a redshift of z~5 from the ALPINE-CRISTAL-JWST sample. This sample was specifically chosen to complement recent studies by JWST at lower stellar masses. The metallicities of these galaxies were determined using strong optical lines and were further verified through temperature-based oxygen abundance measurements for five galaxies where faint auroral lines were detected. The results of this study revealed that there was minimal evolution in the MZR at the massive end between a redshift of z~5 and cosmic noon at z~2. This indicates a rapid enrichment of metals in these early galaxies. Interestingly, the FMR at a redshift of z=5 exhibited a significantly larger scatter, particularly towards lower metallicities, compared to the local FMR relation. This scatter was attributed to bursty star formation processes, direct metal build-up in early galaxies, as well as variations in age and outflow efficiencies. By analyzing all available samples, it was found that the observed MZR and FMR over three orders of stellar mass generally aligned well with results from cosmological simulations. However, some simulations underestimated metal enrichment at lower stellar masses due to overly efficient metal-rich outflows. The researchers suggested that the ALPINE-CRISTAL-JWST galaxies likely integrated into the current FMR around a redshift of z~10 and are expected to evolve into massive galaxies with super-solar metallicities by a redshift of z=0. Overall, this study provides valuable insights into the fast metal enrichment processes occurring in massive galaxies at high redshifts and highlights the complex interplay between star formation, metal production, and galaxy evolution in the early universe.