¹²CO(2−1) (grey), SiO(5−4) (blue), SO(6₅−5₄) (magenta), and ¹³CO(2−1) (cyan) at the positions of the continuum sources A1, A2, and A3 (see Fig. 5). The selected positions are displayed from top to bottom. The ¹²CO(2−1) data have been convolved to match the angular resolution at 1.4 mm (1.′′1×0.′′8). The vertical dashed line marks the systemic velocity of +7.2 km s^-1 for the three continuum sources. We note that the systemic velocity of A3 has been derived from PdBI N₂H⁺(1−0) observations at 93.17 GHz from our CALYPSO dataset.