GALFIT best-fit model of the UV continuum. We show the input image first column), the model (second column), and the residuals (third column) obtained by subtracting the model from the input image. Both galaxy images M1 (top row) and M2 (bottom row) are shown. The cutouts have a size of 3.6″ × 3.6″. The color cuts are the same in all panels of M1 and in all panels of M2. The crosses in the top left panel indicate the barycenter of the M1 galaxy image as estimated with three different methods: from the GALFIT disk-only best fit (black cross), from the GALFIT disk+clumps best fit (cyan cross), and from the SExtractor (blue cross, see Sect. 3.1 for details). The x indicate the clumps detected in the UV continuum.