Spectroscopic confirmation of a massive quiescent galaxy, at z = 4.658, just 1.25 Gyr after the Big Bang,
They used deep continuum observations from JWST NIRSpec
It formed its stellar population over a 200 Myr period, approximately 600 − 800 Myr after the Big Bang (z = 7.3 ± 0.2), before quenching at z = 6.7 ± 0.3
Redshift estimates:
JWST NIRSpec observations of GS-9209 for a z~4.658 galaxy:
Breadcrumbs
A massive quiescent galaxy at redshift 4.658
https://ui.adsabs.harvard.edu/abs/2023arXiv230111413C
Carnall et al. 2023
Redshift estimates:
JWST NIRSpec observations of GS-9209 for a z~4.658 galaxy: