Normalized outflow velocity (V_out/V_circ) as a function of the ratio of the amount of momentum flux supplied by star formation to the value needed to overcome gravity and push the outflowing gas for a cloud model (left) and for a shell model (right). This figure is similar to Fig. 9 in H15. Squares, crosses, triangles, circles, and stars represent respectively the MEGAFLOW, H15, B12, M19, and P23 galaxies. Empty symbols represent down-the-barrel data, whereas filled sybols are from background quasars studies. The left panel, in blue (red), shows the weak (strong) outflows. In the left (right) panel the dashed curve is derived from the equation of motion for a cloud (shell) model (see text). The white squares correspond to less reliable MEGAFLOW outflow properties (for more details, see Schroetter et al. 2019).