From left to right: observed 1.1 mm ALMA continuum images of the targeted protostars; image of the disk model for the source resulting from the Gaussian fitting (in cases where the envelope component is fitted, only the disk component is shown); residual image after subtracting the disk model from the image; residual image after subtracting both disk and envelope models. From top to bottom: cases that occur in the Gaussian fitting procedure are presented: Per-emb-41, single source, without a noticeable contribution from the envelope; Per-emb-7, contribution of the envelope, as assessed by eye, is significant, an additional broad Gaussian with size of 3′′ was added to the input parameters; Per-emb-54, the central compact component was faint compared to the noise level, it was necessary to fix the size of the Gaussian to the synthesized beam size for the fit to converge. Per-emb-51, the central component has a very small flux compared to the envelope.