Observed mass for the pre-BD vs. the estimated mass using a r⁻² density profile. Using that profile and the flux detected with AzTEC we estimate the expected mass inside the ALMA beam. Blue squares are sources in this work detected with ALMA. Red points are sources from Huélamo et al. (2017). The ratio between the observed and the estimated masses is close to ∼1 (orange line) for half of the sources (see Sect. 4.4.2). The other three sources with steeper density profiles might be more evolved as they have accreted more mass onto the central object.