Less Wound and More Asymmetric: JWST Confirms the Evolution of Spiral Structure in Galaxies at $z \lesssim 3$

TL;DR

This study analyzes the evolution of spiral galaxy structures over cosmic time using JWST and HST data, revealing that spiral arms become more tightly wound and asymmetric at higher redshifts, with band-shifting effects influencing observed properties.

Contribution

It provides the first comprehensive measurement of spiral arm parameters in distant galaxies, demonstrating their evolution with redshift and highlighting the impact of observational effects.

Findings

Spiral arms have larger pitch angles at lower redshifts.

Spiral structures are more asymmetric at higher redshifts.

Band-shifting effects can mimic evolutionary changes.

Abstract

Spiral galaxies are ubiquitous in the local Universe. However the properties of spiral arms in them are still not well studied, and there is even less information concerning spiral structure in distant galaxies. We aim to measure the most general parameters of spiral arms in remote galaxies and trace their changes with redshift. We perform photometric decomposition, including spiral arms, for 159 galaxies from the HST COSMOS and JWST CEERS and JADES surveys, which are imaged in optical and near-infrared rest-frame wavelengths. We confirm that, in our representative sample of spiral galaxies, the pitch angles increase, and the azimuthal lengths decrease with increasing redshift, implying that the spiral structure becomes more tightly wound over time. For the spiral-to-total luminosity ratio and the spiral width-to-disc scale length ratio, we find that band-shifting effects can be as significant as, or even stronger than, evolutionary effects. Additionally, we find that spiral structure becomes more asymmetric at higher redshifts.