James Webb Space Telescope Feed Post

Arxiv: ADF22-WEB: ALMA and JWST (sub)kpc-scale views of dusty star-forming galaxies in a z\approx3 proto-cluster Published: 2/4/2025 12:36:39 AM Updated: 2/4/2025 12:36:39 AM

Paper abstract: We present a morphological analysis of ALMA and JWST NIRCam images of ninedusty star-forming galaxies (DSFGs) at zspec=3.09, all embedded within thecosmic web filaments at the SSA22 proto-cluster core. The ALMA 870um and 1.1mmimages are obtained at spatial resolutions ranging from 0.5" to 0.05" (350 pcat z=3.09). The high-resolution images enable us to resolve inner structurestraced by dust continuum, identifying compact dusty cores, clumps, and offsetridges within bars. Sersic profile fit was performed for both ALMA 870um andNIRCam F444W images at comparable resolutions (0.15"). The Sersic indexmeasured for 870um, masking bright regions, indicates values close to unity,suggesting that dust emission arises from disks with superimposed compact corecomponents. For the JWST F444W images (restframe 1um), the Sersic indices rangebetween nF444W = 1-3, pointing to the coexistence of bulges and stellar disksin these DSFGs. A comparison of dust mass surface density, nF444W, andF200W-F444W color (restframe 0.5-1um) reveals diversity among the DSFGs, likelyreflecting different evolutionary stages including some DSFGs with red cores,indicating ongoing rapid bulge growth phases heavily obscured by dust. Thepredominantly disk-like morphologies observed in most DSFGs in theproto-cluster core contrast sharply with early-type morphologies that dominatethe highest density environment in the local universe. This suggests that weare witnessing the early formation of the morphology-density relation, asmassive galaxies undergo rapid growth as late-type galaxies fueled by cosmicweb gas filaments.