Histograms of the sizes of isolated cores, not blended with any other source in any waveband. The core radius is the arithmetic mean of the major and minor half maximum sizes, measured in the surface density images with three different resolutions (indicated by the vertical dashed lines). Panel a: distribution of source radii at 8.5″ resolution. Panel b: distribution of source radii at 11.7″ resolution. Panel c: distribution of source radii at 18.2″ resolution.