Position-velocity diagram along the equatorial axis of the CALYPSO protostellar envelopes. Blue and red dots show the blue- and red-shifted velocities, respectively. The arrows display the upper limits of v_rot determined from velocity maps that do not exhibit a spatial distribution of velocities as organized as one wouldexpect from rotation motions (see Sect. 4.3 and Appendix C). Green dots show the column density profiles along the equatorial axis. Dots and large dots show the C¹⁸O and N₂H⁺ data, respectively. The dashed curve shows the best fit with a power-law model leaving the index α as a free parameter (v_rot ∝ r^α) whereas the dotted curve shows the best fit with a power-law model with a fixed index α = −1. The verticaldashed lines show the transition radii between the different datasets (PdBI, combined, and 30m) and the two tracers as illustrated in Fig. 15 and given in Table C.1.