L_bol/L_submm ratio vs. bolometric temperature of the globule cores (see Table 6 and Sect. 5.4). The size of the symbols scales with the peak column density of the respective sources. Error bars on CB 244 - SMM1 illustrate the 10% relative uncertainity on both values (Sect. 5.4). The “classical” T_bol boundaries for Class 0 protostars are indicated by the vertical dashed lines. The two triangles, connected by a dotted line, represent one synthetic protostar-envelope system taken from (Robitaille et al. 2006), once seen close to edge-on (T_bol = 34 K) and once seen nearly pole-on into the outflow cavity (T_bol = 119 K; see discussion in Sect. 5.4).