Outflow momentum in M_⊙ km s⁻¹ against the luminosity of its driving source in L_⊙. Black circles are from Maud et al. (2015), and open triangles from Duarte-Cabral et al. (2013) for high-mass Class−0 objects, and black squares from Dunham et al. (2014) showing the outflows from low-mass stars. Horizontal lines denote the momentum (multiplied by two as outflows are bipolar) of each dent listed in Table 1. Dent 5 and 6 have a lower limit and are indicated by the dashed red lines.