Distribution of the CO 2–1 and SO N_J = 5₄–4₃ velocity-integrated emission in the central protostellar region. Northern lobe (red): emission is integrated in the velocity range [+40;+80] km s⁻¹ and is displayed in thin and thick contours for CO and SO, respectively. Southern lobe (blue): emission is integrated in the velocity range [−110;−50] km s⁻¹ and is displayed in thin and thick contours for CO and SO, respectively. The velocity interval was chosen in order to include the region of jet acceleration close to the protostar (see Sect. 4.2). The beam sizes (HPBW) of the CO and SO observations (1.07″ × 0.87″ and 0.52″ × 0.41″, respectively) are shown with ellipses in the bottom left corner. The velocity resolution of the CO (SO) observations is 3.3 km s⁻¹ (2.8 km s⁻¹). The first contour and contour interval are 20% and 10% of the peak intensity in each component. The arrow draws the main axis of the jet from protostar B (from Ospina-Zamudio etal. 2018).