Sérsic profile fitting for the BGGs of (a) RO-1001-Sat and (b) RO-0959-Sat. Each row shows the fit for a NIRCam filterband, from top to bottom: F115W, F150W, F277W, and F444W. The first column shows the data as 6″ × 6″ cutouts centred on the respective BGG. The second column shows the best-fit models and the third column shows the residual images (Data-Model). The data, models, and residuals are displayed with the same logarithmic intensity scaling for each filterband.