Context: Galaxy morphology is a fundamental property to describe galaxy evolution. However, the observed morphology of a particular galaxy may depend on the observed wavelength. Aims: Our aim is to investigate the wavelength dependence and the effect of dust attenuation on nonparametric morphology indicators. Methods: We use the TNG50-SKIRT Atlas, an atlas of synthetic UV to near-infrared (NIR) broadband images for a complete stellar-mass-selected sample of 1154 galaxies extracted from the TNG50 cosmological simulation at z=0. For each image, we calculate four nonparametric morphology indicators using the StatMorph code. Results: We find that the known correlations between the stellar mass and the morphological parameters measured in the optical, together with the Gini-M20, concentration-Gini, and concentration-M20 planes, are fully consistent with observational data. However, nonparametric morphological indicators change significantly with wavelength and that this wavelength dependence is stronger for disc-dominated than for bulge-dominated galaxies. The wavelength dependence of the morphology of our simulated TNG50 galaxies is consistent with measurements of local galaxies from the SINGS survey. We demonstrate that the effect of dust attenuation on nonparametric morphology indicators is modest across the full galaxy population but can be significant for individual galaxies.
@article{arxiv.2605.20886,
title = {The TNG50-SKIRT Atlas: Multi-wavelength nonparametric galaxy morphology},
author = {Sena Bokona Tulu and Maarten Baes and Angelos Nersesian and Tolu Biressa and Vicente Rodriguez-Gomez and Andrea Gebek and Marco Martorano and Abdissa Tassama Emana},
journal= {arXiv preprint arXiv:2605.20886},
year = {2026}
}
Comments
13 pages, 8 figures, accepted for publication in A&A