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Arxiv: JWST/CEERS Sheds Light on Dusty Star-Forming Galaxies: Forming Bulges, Lopsidedness and Outside-In Quenching at Cosmic Noon Published: 7/14/2023 10:45:28 PM Updated: 5/1/2024 7:11:02 AM

Paper abstract: We investigate the morphology and resolved physical properties of a sample of22 IR-selected DSFG at Cosmic Noon, using JWST NIRCam images obtained in theEGS field for the CEERS survey. The resolution of the NIRCam images allows usto spatially resolve these galaxies up to 4.4um and identify their bulge/coreeven when extinguished by dust. The goal of this study is to obtain a betterunderstanding of the formation and evolution of FIR-bright galaxies byspatially resolving their properties, using JWST to look through the dust andbridge the gap between the compact FIR sources and the larger optical SFG.Based on RGB images using the NIRCam filters, we divide each galaxy in severaluniformly colored regions, fit their respective SED and measure physicalproperties. After classifying each region as SF or quiescent, we assigngalaxies to three classes, depending on whether active SF is located in thecore, in the disk or in both. Results: (i) We find that the galaxies at higherz tend to have a fragmented disk with a low core mass fraction: they are at anearly stage of bulge formation. When moving toward lower z, the core massfraction increases, and the bulge growth is associated with a stabilization ofthe disk: NIRCam data clearly point towards bulge formation in pre-existingdisks. (ii) Lopsidedness is a common feature of DSFGs, it could have a majorimpact on their evolution; (iii) 23% of galaxies have a SF core embedded in aquiescent disk, they seem to be undergoing outside-in quenching, oftenfacilitated by their strong lopsidedness inducing instabilities; (iv) We showthat half of our galaxies with star-formation concentrated in their core aregood SMG counterpart candidates, demonstrating that compact SMGs are usuallysurrounded by a larger less obscured disk; and (v) we find surprising evidencefor clump-like substructures being quiescent and/or residing in quiescentregions.