Panic! at the Disks: First Rest-frame Optical Observations of Galaxy Structure at z > 3 with JWST in the SMACS 0723 Field

Journal article

We present early results regarding the morphological and structural properties of galaxies seen with the James Webb Space Telescope (JWST) at z > 3 in the Early Release Observations toward the SMACS 0723 cluster field. Using JWST we investigate, for the first time, the optical morphologies of a significant number of z > 3 galaxies with accurate photometric redshifts in this field to determine the form of galaxy structure in the relatively early universe. We use visual morphologies and Morfometryka measures to perform quantitative morphology measurements, both parametric with light profile fitting (Sérsic indices) and nonparametric (concentration, asymmetry, and smoothness (CAS) values). Using these, we measure the relative fraction of disk, spheroidal, and peculiar galaxies at 3 1.5 disk galaxies dominate the overall fraction of morphologies, with a factor of ∼10 relative higher number of disk galaxies than seen by the Hubble Space Telescope at these redshifts. Our visual morphological estimates of galaxies align closely with their locations in CAS parameter space and their Sérsic indices. © 2022. The Author(s). Published by the American Astronomical Society.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Authors: Ferreira, L; Adams, N; Conselice, CJ; Sazonova, E; Austin, D

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Astronomical Society
• Journal: The Astrophysical Journal Letters
• Volume: 938
• Issue: 1
• Pages: L2-L2
• Publication date: 2022-10-10
• DOI: 10.3847/2041-8213/ac947c
• EISSN: 2041-8213
• ISSN: 2041-8205
• Language: English
• Keywords: Galaxy; Hubble space telescope; Universe; Elliptical galaxy; Astronomy; Galaxy formation and evolution; James Webb Space Telescope; Physics; Galaxy cluster; Astrophysics; Hubble Deep Field; Redshift