SiS υ = 0, J = 12–11 velocity-channel maps with a beam with HPBW=20 mas × 20 mas; note the smaller field of view compared with that of the 60 mas-resolution maps show in Fig. 7. Contours are 2σ, 4σ, … by 4σ (σ = 0.5 mJy beam⁻¹). In the last panel, the zeroth moment map of SiS (integrated over V_LSR = [18:52] km s⁻¹) is shown (color scale and wedge) together with that of the NaCl line-stacked data (contours). Units of the wedge are Jy beam⁻¹ km s⁻¹. Two orthogonal segments are used to outline the opening angle of the SS-outflow at its base (~90°).