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arXiv:2207.09428astro-ph.GA

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

Leonardo Ferreira, Nathan Adams, Christopher J. Conselice, Elizaveta Sazonova, Duncan Austin, Joseph Caruana, Fabricio Ferrari, Aprajita Verma, James Trussler, Tom Broadhurst, Jose Diego, Brenda L. Frye, Massimo Pascale, Stephen M. Wilkins, Rogier A. Windhorst, Adi Zitrin

Abstract

We present early results regarding the morphological and structural properties of galaxies seen with the James Webb Space Telescope at $z > 3$ in the Early Release Observations of SMACS 0723, a galaxy cluster at $z=0.39$. 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 \textsc{Morfometryka} measures to perform quantitative morphology measurements, both parametric with light profile fitting (Sérsic indices) and non-parametric (CAS values). Using these, we measure the relative fraction of disk, spheroidal, and peculiar galaxies at $3 < z < 8$. We discover the surprising result that at $z > 1.5$ disk galaxies dominate the overall fraction of morphologies, with a factor of $\sim 10$ 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.

arXiv comments
11 pages, 7 figures. Accepted for publication in ApJL
Journal reference
DOI
doi:10.3847/2041-8213/ac947c
Subjects
astro-ph.GAAstrophysics of Galaxies

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Linked by 3 identifiable commenters in 3 comments across 3 threads, from Aug 2022 to Aug 2022. Found in 2 HN submissions from Aug 2022 to Aug 2022. Open submission discussions.

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Discussed in comments3 threads

  1. Scientists puzzled because James Webb is seeing stuff that shouldn't be there 1 comment

    • Link to relevant paper, looking at shape/form of redshifted (far away) galaxies under heavy lensing (high interstellar magnification). "First Rest-Frame Optical Observation of Galaxy at Z3 with JWST in Smacs 0723 Field" https://arxiv.org/abs/2207.09428…

      rektideView on HNParent context

  2. We don't know how the universe began, and we will never know 1 comment

    • Early pixel blob analysis (I don't know a better way to put this, check Figure 5 in the paper) from the James Webb: https://arxiv.org/pdf/2207.09428.pdf Suggests that the universe may be older than the Big Bang theory predicts. There are a lot of qualifiers on both sides of…

      neffyView on HNParent context

  3. [dead] 1 comment

    • > The unexpected new data coming back from the telescope are inspiring panic among astronomers This assumption that surprising results induce panic, fear or worry in scientists speaks volumes in itself. Nothing could please a true scientist more than discovering something new…

      adhesive_wombatView on HNParent context

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