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Arxiv: Near-IR clumps and their properties in high-z galaxies with JWST/NIRCam Published: 2/5/2024 4:28:07 AM Updated: 1/29/2025 4:12:32 AM

Paper abstract: Resolved stellar morphology of z>1 galaxies was inaccessible before JWST.This limitation, due to the impact of dust on rest-frame UV light, had withheldmajor observational conclusions required to understand the importance of clumpsin galaxy evolution. Essentially independent of this issue, we use therest-frame near-IR for a stellar-mass dependent clump detection method anddetermine reliable estimations of selection effects. We exploit publiclyavailable JWST/NIRCam and HST/ACS imaging data from CEERS, to create astellar-mass based picture of clumps in a mass-complete sample of 418 galaxieswithin a wide wavelength coverage of 0.5-4.6\,\mum and a redshift window of1 < z < 2. We find that a near-IR detection gives access to a larger, andpossibly different, set of clumps within galaxies, with those also detected inUV making up only 28\%. Whereas, 85\% of the UV clumps are found to have anear-IR counterpart. These near-IR clumps closely follow the UVJ classificationof their respective host galaxies, with these hosts mainly populating thestar-forming regime besides a fraction of them (16\%) that can be consideredquiescent. The mass of the detected clumps are found to be within the range of10^{7.5-9.5}\,\rm M_{\odot}, therefore expected to drive gas into galaxycores through tidal torques. The clump stellar mass function is found to have aslope of -1.50 \pm 0.14, indicating a hierarchical nature similar to that ofstar-forming regions in the local Universe. Finally, we observe a radialgradient of increasing clump mass towards the centre of galaxies.