Galaxy morphology from z ∼ 6 through the lens of JWST

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

Astronomy and Astrophysics

Advertised on:
5
2024
Number of authors
30
IAC number of authors
4
Citations
44
Refereed citations
35
Description
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.

The catalog is available at the CDS via anonymous ftp to cdsarc.cds.unistra.fr (ftp://130.79.128.5) or via https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/685/A48

Related projects
Group members
Traces of Galaxy Formation: Stellar populations, Dynamics and Morphology
We are a large, diverse, and very active research group aiming to provide a comprehensive picture for the formation of galaxies in the Universe. Rooted in detailed stellar population analysis, we are constantly exploring and developing new tools and ideas to understand how galaxies came to be what we now observe.
Ignacio
Martín Navarro