ADF22-WEB: ALMA and JWST (sub)kpc-scale views of dusty star-forming galaxies in a $z\approx$3 proto-cluster

TL;DR

This study uses high-resolution ALMA and JWST images to analyze the structures of dusty star-forming galaxies at z≈3 within a proto-cluster, revealing diverse morphologies and early formation stages of galaxy evolution.

Contribution

It provides detailed morphological insights into DSFGs at high redshift using combined ALMA and JWST data, highlighting early disk and bulge formation in a proto-cluster environment.

Findings

Most DSFGs have disk-like morphologies with compact cores.

Diversity in dust and stellar structures indicates different evolutionary stages.

Early formation of the morphology-density relation observed.

Abstract

We present a morphological analysis of ALMA and JWST NIRCam images of nine dusty star-forming galaxies (DSFGs) at zspec=3.09, all embedded within the cosmic web filaments at the SSA22 proto-cluster core. The ALMA 870um and 1.1mm images are obtained at spatial resolutions ranging from 0.5" to 0.05" (350 pc at z=3.09). The high-resolution images enable us to resolve inner structures traced by dust continuum, identifying compact dusty cores, clumps, and offset ridges within bars. Sersic profile fit was performed for both ALMA 870um and NIRCam F444W images at comparable resolutions (0.15"). The Sersic index measured for 870um, masking bright regions, indicates values close to unity, suggesting that dust emission arises from disks with superimposed compact core components. For the JWST F444W images (restframe 1um), the Sersic indices range between nF444W = 1-3, pointing to the coexistence of bulges and stellar disks in these DSFGs. A comparison of dust mass surface density, nF444W, and F200W-F444W color (restframe 0.5-1um) reveals diversity among the DSFGs, likely reflecting different evolutionary stages including some DSFGs with red cores, indicating ongoing rapid bulge growth phases heavily obscured by dust. The predominantly disk-like morphologies observed in most DSFGs in the proto-cluster core contrast sharply with early-type morphologies that dominate the highest density environment in the local universe. This suggests that we are witnessing the early formation of the morphology-density relation, as massive galaxies undergo rapid growth as late-type galaxies fueled by cosmic web gas filaments.