UNCOVER: The rest ultraviolet to near infrared multiwavelength structures and dust distributions of sub-millimeter-detected galaxies in Abell 2744

TL;DR

This study uses JWST and ALMA data to analyze the multiwavelength structures and dust distributions of sub-millimeter galaxies at cosmic noon, revealing their compactness, dust concentration, and the influence of dust on observed properties.

Contribution

First detailed multiwavelength structural analysis of faint sub-mm galaxies at z~1-3.5 using JWST and ALMA data, highlighting dust's role in galaxy morphology.

Findings

Galaxies are smaller and more concentrated at longer wavelengths.

Most galaxies show centrally-concentrated dust affecting color gradients.

Dust quantity and geometry influence multiwavelength structures.

Abstract

With the wavelength coverage, sensitivity, and high spatial resolution of JWST, it is now possible to peer through the dust attenuation to probe the rest-frame near infrared (NIR) and stellar structures of extremely dusty galaxies at cosmic noon (z~1-3). In this paper we leverage the combined ALMA and JWST/HST coverage in Abell 2744 to study the multiwavelength (0.5-4.4${\mu}$m) structures of 11 sub-millimeter (sub-mm) detected galaxies at z~0.9-3.5 that are fainter than bright "classical" sub-mm galaxies (SMGs); 7 of which are detected in deep X-ray data. While these objects reveal a diversity of structures and sizes, all are smaller and more concentrated towards longer wavelengths. Of the X-ray-detected objects, only two show evidence for appreciable AGN flux contributions (at ${\gtrsim}$2${\mu}$m). Excluding the two AGN-dominated objects, the smaller long wavelength sizes indicate that their rest-frame NIR light profiles, inferred to trace their stellar mass profiles, are more compact than their optical profiles. The sub-mm detections and visible dust lanes suggest centrally-concentrated dust is a key driver of the observed color gradients. Further, we find that more concentrated galaxies tend to have lower size ratios (rest-frame NIR to optical); this suggests that the galaxies with the most compact light distributions also have the most concentrated dust. The 1.2mm flux densities and size ratios of these 9 objects suggest that both total dust quantity and geometry impact these galaxies' multiwavelength structures. Upcoming higher resolution 1.2mm ALMA imaging will facilitate joint spatially-resolved analysis and will directly test the dust distributions within this representative sub-mm population.