A massive compact quiescent galaxy at z = 2 with a complete Einstein ring in JWST imaging.

ABSTRACT: One of the surprising results from the Hubble Space Telescope was the discovery that many of the most massive galaxies at redshift z ≈ 2 are very compact, having a half-light radius of only 1-2 kpc. The interpretation is that massive galaxies formed inside out, with their cores largely in place by z ≈ 2 and approximately half of their present-day mass added later through minor mergers. Here we present a compact, massive, quiescent galaxy at a photometric redshift of zphot=1.94-0.17+0.13 with a complete Einstein ring. The ring was found in the James Webb Space Telescope COSMOS-Web survey and is produced by a background galaxy at zphot=2.98-0.47+0.42. Its 1.54″ diameter provides a direct measurement of the mass of the 'pristine' core of a massive galaxy, observed before

SUBMITTER: van Dokkum P 

PROVIDER: S-EPMC10803264 | biostudies-literature | 2024

REPOSITORIES: biostudies-literature