Galaxy morphology from z ~ 6 through the lens of JWST

M. Huertas-Company, K. G. Iyer, E. Angeloudi, M. B. Bagley, S. L. Finkelstein, J. Kartaltepe, E. J. McGrath, R. Sarmiento, J. Vega-Ferrero, P. Arrabal Haro, P. Behroozi, F. Buitrago, Y. Cheng, L. Costantin, A. Dekel, M. Dickinson, D. Elbaz, N. A. Grogin, N. P. Hathi, B. W. HolwerdaA. M. Koekemoer, R. A. Lucas, C. Papovich, P. G. Pérez-González, N. Pirzkal, L. M. Seillé, A. De La Vega, S. Wuyts, G. Yang, L. Y.A. Yung

Research output: Contribution to journalArticlepeer-review

2 Citations (SciVal)

Abstract

Context: The James Webb Space Telescope's (JWST's) unprecedented combination of sensitivity, spatial resolution, and infrared coverage has enabled a new era of galaxy morphology exploration across most of cosmic history. 

Aims: We analyze the near-infrared (NIR ~ 0.8 -1 μm) rest-frame morphologies of galaxies with log M/M > 9 in the redshift range of 0 < z < 6, compare with previous HST-based results and release the first JWST-based morphological catalog of ~20 000 galaxies in the CEERS survey. 

Methods: We classified the galaxies in our sample into four main broad classes: spheroid, disk+spheroid, disk, and disturbed, based on imaging with four filters: F150W, F200W, F356W, and F444W. We used convolutional neural networks (CNNs) trained on HST/WFC3 labeled images and domain-adapted to JWST/NIRCam. 

Results: We find that ~90% and ~75% of galaxies at z < 3 have the same early and late and regular and irregular classification, respectively, in JWST and HST imaging when considering similar wavelengths. For small (large) and faint objects, JWST-based classifications tend to systematically present less bulge-dominated systems (peculiar galaxies) than HST-based ones, but the impact on the reported evolution of morphological fractions is less than ~10%. Using JWST-based morphologies at the same rest-frame wavelength ( ~0.8 -1 μm), we confirm an increase in peculiar galaxies and a decrease in bulge-dominated galaxies with redshift, as reported in previous HST-based works, suggesting that the stellar mass distribution, in addition to light distribution, is more disturbed in the early Universe. However, we find that undisturbed disk-like systems already dominate the high-mass end of the late-type galaxy population (log M/M > 10.5) at z ~ 5, and bulge-dominated galaxies also exist at these early epochs, confirming a rich and evolved morphological diversity of galaxies ~1 Gyr after the Big Bang. Finally, we find that the morphology-quenching relation is already in place for massive galaxies at z > 3, with massive quiescent galaxies (log M/M > 10.5) being predominantly bulge-dominated.

Original languageEnglish
Article numberA48
JournalAstronomy and Astrophysics
Volume685
Early online date3 May 2024
DOIs
Publication statusPublished - 31 May 2024

Keywords

  • Catalogs
  • Galaxies: evolution
  • Galaxies: high-redshift
  • Galaxies: statistics
  • Galaxies: structure

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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