Visibility profiles of the 231 GHz (black dots) and 94 GHz (gray triangles) continuum emission from L1448-NB1.Open symbols are used when the visibility real part has a negative value (since absolute values are shown in the log–log plot). In each visibility curve, we show both the best Plummer-only model (Pl, black curve) and the best Plummer + Gauss (PG, red curve) model. In the case of L1448-NB1, the F-test suggests that the PG model for the 231 GHz profile does not perform statistically better than the Plummer-only (Pl) model (see Table 6 for more information on the two models). For the 94 GHz profile, the PG model that includes a 0.94′′ Gaussian component performs better than the Pl model, although none of the two models does satisfactorily reproduce the visibility profile (reduced chi square > 3 in both cases).