Envelope mass vs. bolometric luminosity diagram from Andre et al. (2000) and Maury et al. (2011). The small black squares and triangles are Class 0 and I protostars detected in the Aquila rift, Ophiuchus, Perseus, and Orion regions (Bontemps et al. 1996; Motte & André 2001; Andre et al. 2000; Maury et al. 2011; Sadavoy et al. 2014). The lines indicate the conceptual border zone between the Class 0 and Class I stage, with M_env ∝ L_bol for the dashed line and for the dotted line. Blue lines with arrows represent protostellar evolutionary tracks, computed for final stellar masses of 0.1, 0.3, 1, and 3M_⊙; the evolution proceeds from top left (objects with large envelope masses slowly accreting) to bottom (the envelope mass and the accretion luminosity are rapidly decreasing). Our sample is overlaid with the positions of protostars in our sample: B335 in yellow, IRAS16293 in purple, Perseus sources in green, and Cepheus sources in light blue. The sample only contains low-mass Class 0 protostars, except for SVS13-A. The M_env and L_bol are from Massi et al. (2008) for CB230, Launhardt et al. (2013) for B335, Crimier et al. (2010) for IRAS16293, Sadavoy et al. (2014), Ladjelate et al. (in prep.), and Maury et al. (in prep.) for the rest of the sources.