Lyman continuum, N_Ly (from Table 5), as a function of the bolometric luminosity, L_bol. Open and filled symbols denote Low and High sources, respectively. The different colors indicate the Type 1 (blue), Type 2 (green), and Type 3 (red), while the black symbols correspond to those centimeter sources not classified in any of the three types (see Sect. 6). The red solid line corresponds to the Lyman continuum of a ZAMS star of a given bolometric luminosity, while the dashed region indicates the expected N_Ly if L_bol is due to a cluster (see Sect. 5.2 for details). The black solid line corresponds to the Lyman continuum expected from a black-body with the same radius and temperature as a ZAMS star. At the top and right axes we list the spectral type corresponding to a given Lyman continuum and a given bolometric luminosity. The arrow indicates by how much a point should be shifted if its distance is doubled.