Masses M_ℐ derived from fitting images ℐ_ν of the isothermal models of both isolated and embedded starless cores and protostellar envelopes for the correct value of β = 2. Two columns of panels (left, middle) display the masses derived for resolved and unresolved images of the isolated models, whereas the third column of panels (right) present results for unresolved embedded models. Angular resolutions do not make any difference for the isothermal models. See Fig. D.2 and Fig. 8 for more details.