a) Total mass versus mean FWHM size for the 60 starless (or Class 0) sources found with Gaussclumps in the sum map of Cha I at scale 5. The angular resolution (21.2″) is marked by the dotted line. The solid line (M ∝ FWHM²) is the 5σ peak sensitivity limit for Gaussian sources. The dashed line shows the 6.3σ peak sensitivity limit which corresponds to a completeness limit of 90% for Gaussian sources. b) Total mass versus mean deconvolved FWHM size. Sizes smaller than 25.4″ were set to 25.4″ before deconvolution (see note b of Table 6). The solid line shows the relation that characterizes critical Bonnor-Ebert spheres (see Sect. 6.1.6). The dash-dotted and dashed lines show the location of this relation when divided by 2 and 5, respectively. The sources with a mass larger than the critical Bonnor-Ebert mass M_BE,Pext estimated from the ambient cloud pressure are shown with a filled circle. Those with 0.5   M_BE,Pext < M < M_BE,Pext are shown with a circle. c) Mass concentration versus mean FWHM size. The dashed line is the expectation for a circular Gaussian flux density distribution.