Size-line width coefficient versus surface density for the Firecracker cloud (Finn et al. 2019) and the M4, M5, and M6 clouds. The four red diamonds are observations, done using apertures (1–4) with radii R = 6.4, 15, 26, and 37 pc. The other points are our simulations, with connected points corresponding to apertures (1–4) of radii R = 5, 10, 15 and 20 pc. The colors indicate how much stellar mass has been produced (with empty points indicating no star formation). The lines correspond to virial equilibrium and free-fall as labeled (see Fig. 2 of Ballesteros-Paredes et al. 2011).