Galaxy morphologies at cosmic noon with JWST: A foundation for exploring gas transport with bars and spiral arms
Juan M. Espejo Salcedo, Stavros Pastras, J. Vácha, C. Pulsoni, R. Genzel, N. M. Förster Schreiber, Jean-Baptiste Jolly, Capucine Barfety, Jianhang Chen, Giulia Tozzi, Daizhong Liu, Lilian L. Lee, Stijn Wuyts, L. J. Tacconi, R. Davies, Hannah Übler, D. Lutz, Emily Wisnioski, J. Shangguan, Minju Lee, Sedona H. Price, Frank Eisenhauer, Alvio Renzini, Amit Nestor Shachar, Rodrigo Herrera-Camus
Abstract
The way in which radial flows shape galaxy structure and evolution remains an open question. Internal drivers of such flows, such as bars and spiral arms, known to mediate gas flows in the local Universe, are now observable at high redshift thanks to JWST’s unobscured view. We investigated the morphology of massive star-forming galaxies at 0.8 < z < 1.3 and 2.0 < z < 2.5, epochs marking the peak and decline of cosmic star formation, both well covered by kinematic surveys. Using JWST/NIRCam imaging, we visually classified 1451 galaxies, identified non-axisymmetric features, counted the number of spiral arms, analyzed nonparametric morphological indicators, and studied the dynamical support of the sample covered by kinematics (≈11% of the sample) as measured via v / σ . Disk galaxies dominate the sample (fraction 0.82 ± 0.03); among them, 0.48 ± 0.04 exhibit spiral structure and 0.11 ± 0.03 host bars. Both fractions decline with redshift, in agreement with previous studies. The proportion of two- and three-armed spirals remains largely unchanged across our redshift bins: approximately two-thirds show two arms and one-third show three arms in both bins. Notably, we find a higher incidence of three-armed spirals (≈0.30) than reported in the local Universe (≈0.20), suggesting a mild evolution in spiral arm multiplicity. Nonparametric morphological metrics strongly correlate with stellar mass but show no significant redshift evolution. Finally, kinematic analysis reveals a correlation between disk morphology and rotational support: most disks exhibit v / σ > 3 and median values of v / σ > 7 for spirals and v / σ > 5 for barred galaxies. This study establishes a population-wide framework for linking galaxy morphology and dynamics at cosmic noon, providing a key reference for future studies on the role of detailed structural features in galaxy evolution.