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Near-infrared characterization of ultra-diffuse galaxies in Abell 2744 by JWST/NIRISS imaging Published: 12/21/2022 9:00:05 PM Updated: 6/5/2023 5:18:47 PM

Paper abstract: We present a search and characterization of ultra-diffuse galaxies (UDGs) inthe Frontier Fields cluster Abell~2744 at z=0.308. We use JWST/NIRISS F200Wobservations, acquired as part of the GLASS-JWST Early Release Science Program,aiming to characterize morphologies of cluster UDGs and their diffuse stellarcomponents. A total number of 22 UDGs are identified by our selection criteriausing morphological parameters, down to stellar mass of ~10^{7}M_{\odot}.The selected UDGs are systematically larger in effective radius in F200W thanin HST/ACS F814W images, which implies that some of them would not have beenidentified as UDGs when selected at rest-frame optical wavelengths. In fact, wefind that about one third of the UDGs were not previously identified based onthe F814W data. We observe a flat distribution of the UDGs in the stellarmass-size plane, similar to what is found for cluster quiescent galaxies atcomparable mass. Our pilot study using the new JWST F200W filter showcases theefficiency of searching UDGs at cosmological distances, with 1/30 of theexposure time of the previous deep observing campaign with HST. Further studieswith JWST focusing on spatially-resolved properties of individual sources willprovide insight into their origin.