Early Results from GLASS-JWST. V: The First Rest-frame Optical Size-Luminosity Relation of Galaxies at z

Yang, L.L.YangMorishita, T.T.MorishitaLeethochawalit, N.N.LeethochawalitCASTELLANO, MarcoMarcoCASTELLANOCalabrò, A.A.CalabròTreu, T.T.TreuBONCHI, AndreaAndreaBONCHIFONTANA, AdrianoAdrianoFONTANAMason, C.C.MasonMERLIN, EmilianoEmilianoMERLINPARIS, DiegoDiegoPARISTrenti, M.M.TrentiRoberts-Borsani, G.G.Roberts-BorsaniBradac, M.M.BradacVANZELLA, ErosErosVANZELLAVULCANI, BenedettaBenedettaVULCANIMarchesini, D.D.MarchesiniDing, X.X.DingNanayakkara, T.T.NanayakkaraBirrer, S.S.BirrerGlazebrook, K.K.GlazebrookJones, T.T.JonesBoyett, K.K.BoyettSANTINI, PaolaPaolaSANTINIStrait, V.V.StraitWang, X.X.Wang2025-03-212025-03-2120222041-8205http://hdl.handle.net/20.500.12386/36901We present the first rest-frame optical size-luminosity relation of galaxies at z > 7, using the NIRCam imaging data obtained by the GLASS James Webb Space Telescope Early Release Science (GLASS-JWST-ERS) program, providing the deepest extragalactic data of the ERS campaign. Our sample consists of 19 photometrically selected bright galaxies with m F444W ≤ 27.8 at 7 < z < 9 and m F444W < 28.2 at z ~ 9-15. We measure the size of the galaxies in five bands, from rest-frame optical (~4800 Å) to the UV (~1600 Å) based on the Sérsic model, and analyse the size-luminosity relation as a function of wavelength. Remarkably, the data quality of the NIRCam imaging is sufficient to probe the half-light radius r e down to ~100 pc at z > 7. Given the limited sample size and magnitude range, we first fix the slope to that observed for larger samples in rest-frame UV using Hubble Space Telescope samples. The median size r 0 at the reference luminosity M = -21 decreases slightly from rest-frame optical (600 ± 80 pc) to UV (450 ± 130 pc). We then refit the size-luminosity relation allowing the slope to vary. The slope is consistent with β ~ 0.2 for all bands except F150W, where we find a marginally steeper slope of β = 0.53 ± 0.15. The steep UV slope is mainly driven by the smallest and faintest galaxies. If confirmed by larger samples, it implies that the UV size-luminosity relation breaks toward the faint end, as suggested by lensing studies.STAMPAenEarly Results from GLASS-JWST. V: The First Rest-frame Optical Size-Luminosity Relation of Galaxies at z > 7Article10.3847/2041-8213/ac88032-s2.0-85141329518https://iopscience.iop.org/article/10.3847/2041-8213/ac8803https://api.elsevier.com/content/abstract/scopus_id/851413295182022ApJ...938L..17YFIS/05 - ASTRONOMIA E ASTROFISICA