A) Location of a dust wave r_min (black contours) in pc evaluated for a grid of ionizing source luminosities Q₀ and ambient densities n_H for v_f = 10 km s^-1. The dotted contours represent r_min calculated with v_f = 5 km s^-1 and 20 km s^-1 (a lower flow velocity will move the contours to the right in this figure). Overplotted are different astronomical objects, located in regimes drawn in Fig. 5: UC- H II /HC- H II; (Wood & Churchwell 1989), C- H II; (Garay et al. 1993) and evolved  H II bubbles; (Paladini et al. 2012). We also show SSCs in the Local Group; (compiled from Turner 2009), merging galaxies; (Gilbert & Graham 2007), starburst galaxies; (McCrady & Graham 2007), and ULIRGs; (Anantharamaiah et al. 2000). Larger symbols correspond to prototypical candidates of a class denoted between brackets Fig. 5. B1), B2), and B3) coupling strength C (black contours), evaluated for a flow velocity v_f = 5 km s^-1, 10 km s^-1, and 20 km s^-1.