CASA simulated SMA 1.3 mm continuum map of the SDC13 region (bottom) made using RADMC-3D models A2b (top) and D3b (centre; see Table 4). Map contours are at 2, 4, 6, 8 and 10 mJy. The rms noise in the centre of the map ~0.3 mJy. Model fluxes for A2b (shown in red) and D3b (shown in green) are compared with plots of the observed MAMBO 1.2 mm flux against equivalent radius for MM1 and MM2 respectively (solid black lines). Model parameters are given in the key of each plot, with further details given in the text. The grey lines in the top two plots indicate perpendicular slices of observed flux against radius; these slices give an indication of variation in the observed flux distributions in MM1 and MM2. The dashed curves indicate the MAMBO beam (FWHM = 10.7′′).