A luminous and young galaxy at z = 12.33 revealed by a JWST/MIRI detection of Hα and [O iii]
Journal article, 2024

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

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

Swiss Federal Institute of Technology in Lausanne (EPFL)

Osservatorio Astronomico di Trieste

Ryota Ikeda

The Graduate University for Advanced Studies (SOKENDAI)

National Astronomical Observatory of Japan

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

University of Ferrara

Istituto nazionale di astrofisica (INAF)

T. Saito

National Astronomical Observatory of Japan

P. Santini

Osservatorio Astronomico di Roma

Roberto Terlevich

University of Cambridge

National Institute of Astrophysics, Optics and Electronics

National University of La Plata

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. In Press

Subject Categories

Astronomy, Astrophysics and Cosmology

DOI

10.1038/s41550-024-02397-3

More information

Latest update

11/13/2024