A luminous and young galaxy at z = 12.33 revealed by a JWST/MIRI detection of Hα and [O iii]
Journal article, 2025
The James Webb Space Telescope has discovered a surprising population of bright galaxies in the very early Universe (≲500 Myr after the Big Bang) that is hard to explain with conventional galaxy-formation models and whose physical properties are not fully understood. Insight into their internal physics is best captured through nebular lines, but at these early epochs, the brightest of these spectral features are redshifted into the mid-infrared and remain elusive. Using the mid-infrared instrument onboard the James Webb Space Telescope, here we present a detection of Hα and doubly ionized oxygen ([O iii] 4959,5007 Å) from the bright, ultra-high-redshift galaxy candidate GHZ2/GLASS-z12. Based on these emission lines, we infer a spectroscopic redshift of z = 12.33 ± 0.04, placing this galaxy just ~400 Myr after the Big Bang. These observations provide key insights into the conditions of this primaeval, luminous galaxy, which shows hard ionizing conditions rarely seen in the local Universe and probably driven by a compact and young burst (≲30 Myr) of star formation. The galaxy’s oxygen-to-hydrogen abundance is close to a tenth of the solar value, indicating a rapid metal enrichment. This study establishes the unique conditions of this notably bright and distant galaxy and the huge potential of mid-infrared observations to characterize these primordial systems.
Author
J. A. Zavala
National Astronomical Observatory of Japan
M. Castellano
Osservatorio Astronomico di Roma
Hollis B. Akins
The University of Texas at Austin
Tom Bakx
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Denis Burgarella
Laboratoire d'Astrophysique de Marseille
Caitlin M. Casey
The University of Texas at Austin
Óscar A. Chávez Ortiz
The University of Texas at Austin
Mark Dickinson
NOIRLab
Steven L. Finkelstein
The University of Texas at Austin
Ikki Mitsuhashi
University of Tokyo
National Astronomical Observatory of Japan
Kimihiko Nakajima
National Astronomical Observatory of Japan
P.G.P. Pérez-González
Centro de Astrobiologia (CAB)
Pablo Arrabal Haro
NOIRLab
Pietro Bergamini
Istituto nazionale di astrofisica (INAF)
University of Milan
V. Buat
Laboratoire d'Astrophysique de Marseille
Bren Backhaus
University of Connecticut
Antonello Calabrò
Osservatorio Astronomico di Roma
Nikko J. Cleri
Texas A&M University
David Fernández-Arenas
Universidad Nacional Autónoma de México
Canada France Hawaii Telescope Corporation
A. Fontana
Osservatorio Astronomico di Roma
M. Franco
The University of Texas at Austin
Claudio Grillo
Istituto nazionale di astrofisica (INAF)
University of Milan
M. Giavalisco
University of Massachusetts
Norman A. Grogin
Space Telescope Science Institute (STScI)
N. Hathi
Space Telescope Science Institute (STScI)
Michaela Hirschmann
Osservatorio Astronomico di Trieste
Swiss Federal Institute of Technology in Lausanne (EPFL)
Ryota Ikeda
National Astronomical Observatory of Japan
The Graduate University for Advanced Studies (SOKENDAI)
Intae Jung
Space Telescope Science Institute (STScI)
Jeyhan S. Kartaltepe
Rochester Institute of Technology
Anton M. Koekemoer
Space Telescope Science Institute (STScI)
Rebeca L. Larson
Rochester Institute of Technology
The University of Texas at Austin
Jed McKinney
The University of Texas at Austin
Casey Papovich
Texas A&M University
Piero Rosati
Istituto nazionale di astrofisica (INAF)
University of Ferrara
T. Saito
National Astronomical Observatory of Japan
P. Santini
Osservatorio Astronomico di Roma
Roberto Terlevich
University of Cambridge
National University of La Plata
National Institute of Astrophysics, Optics and Electronics
Elena Terlevich
National Institute of Astrophysics, Optics and Electronics
University of Cambridge
National University of La Plata
Tommaso Treu
University of California
L. Y.Aaron Yung
Space Telescope Science Institute (STScI)
Nature Astronomy
23973366 (eISSN)
Vol. 9 1 155-164Subject Categories (SSIF 2011)
Astronomy, Astrophysics and Cosmology
DOI
10.1038/s41550-024-02397-3