SCUBADive I: JWST+ALMA Analysis of 289 sub-millimeter galaxies in COSMOS-Web

TL;DR

This study constructs a detailed sample of 289 sub-millimeter galaxies in COSMOS-Web using JWST and ALMA data, revealing their properties, morphologies, and clustering behavior at high redshifts.

Contribution

It provides the first large, joint JWST and ALMA analysis of sub-millimeter galaxies, including new insights into their redshifts, morphologies, and clustering.

Findings

Average redshift z=2.6 and stellar mass log(M*)=11.1.

30% of galaxies have no previous optical/near-infrared detections.

Clustering within 10 arcseconds is twice as high as random expectation.

Abstract

JWST has enabled detecting and spatially resolving the heavily dust-attenuated stellar populations of sub-millimeter galaxies, revealing detail that was previously inaccessible. In this work we construct a sample of 289 sub-millimeter galaxies with detailed joint ALMA and JWST constraints in the COSMOS field. Sources are originally selected using the SCUBA-2 instrument and have archival ALMA observations from various programs. Their JWST NIRCam imaging is from COSMOS-Web and PRIMER. We extract multi-wavelength photometry in a manner that leverages the unprecedented near-infrared spatial resolution of JWST, and fit the data with spectral energy distribution models to derive photometric redshifts, stellar masses, star-formation rates and optical attenuation. The sample has an average z=2.6, A_V=2.5, SFR=270 and log(M*)=11.1. There are 81 (30%) galaxies that have no previous optical/near-infrared detections, including 75% of the z>4 sub-sample (n=28). The faintest observed near-infrared sources have the highest redshifts and largest A_V=4. In a preliminary morphology analysis we find that ~10% of our sample exhibit spiral arms and 5% host stellar bars, with one candidate bar found at z>3. Finally, we find that the clustering of JWST galaxies within 10 arcseconds of a sub-mm galaxy is a factor of 2 greater than what is expected based on either random clustering or the distribution of sources around any red galaxy irrespective of a sub-mm detection.