학술논문
UNCOVER: Illuminating the Early Universe—JWST/NIRSpec Confirmation of z > 12 Galaxies
Document Type
article
Author
Bingjie Wang; Seiji Fujimoto; Ivo Labbé; Lukas J. Furtak; Tim B. Miller; David J. Setton; Adi Zitrin; Hakim Atek; Rachel Bezanson; Gabriel Brammer; Joel Leja; Pascal A. Oesch; Sedona H. Price; Iryna Chemerynska; Sam E. Cutler; Pratika Dayal; Pieter van Dokkum; Andy D. Goulding; Jenny E. Greene; Y. Fudamoto; Gourav Khullar; Vasily Kokorev; Danilo Marchesini; Richard Pan; John R. Weaver; Katherine E. Whitaker; Christina C. Williams
Source
The Astrophysical Journal Letters, Vol 957, Iss 2, p L34 (2023)
Subject
Language
English
ISSN
2041-8213
2041-8205
2041-8205
Abstract
Observations of high-redshift galaxies provide a critical direct test to the theories of early galaxy formation, yet to date, only three have been spectroscopically confirmed at z > 12. Due to strong gravitational lensing over a wide area, the galaxy cluster field A2744 is ideal for searching for the earliest galaxies. Here we present JWST/NIRSpec observations of two galaxies: a robust detection at ${z}_{\mathrm{spec}}={12.393}_{-0.001}^{+0.004}$ , and a plausible candidate at ${z}_{\mathrm{spec}}={13.079}_{-0.001}^{+0.013}$ . The galaxies are discovered in JWST/NIRCam imaging and their distances are inferred with JWST/NIRSpec spectroscopy, all from the JWST Cycle 1 UNCOVER Treasury survey. Detailed stellar population modeling using JWST NIRCam and NIRSpec data corroborates the primeval characteristics of these galaxies: low mass (∼10 ^8 M _⊙ ), young, rapidly assembling, metal-poor, and star-forming. Interestingly, both galaxies are spatially resolved, having lensing-corrected rest-UV effective radii on the order of 300–400 pc, which are notably larger than other spectroscopically confirmed systems at similar redshifts. The observed dynamic range of z ≳ 10 sizes spans over 1 order of magnitude, implying a significant scatter in the size–mass relation at early times. Deep into the epoch of reionization, these discoveries elucidate the emergence of the first galaxies.