SVS13-A region as imaged using SO. Left panel: spatial distribution of the SO(2₃ –1₂) red- and blue-shifted emission overlaid with the 90 GHz continuum map (see Fig. 1). Red-shifted emission maps have been derived by integrating the SO emission from the systemic velocity (+8.6 km s⁻¹, Chen et al. 2009) up to +20 km s⁻¹. Blue-shifted image has been obtained by integrating down to –94 km s⁻¹ in absolute values). Angular offset are with respect to the phase centre (see Sect. 3). First contour and steps are 3σ and 4σ, respectively. The 1σ value is 5 mJy km s⁻¹ and 14 mJy km s⁻¹ for the red- and blue-shifted emission, respectively. The filled ellipse shows the synthesized beam (HPBW): 1.′′ 6 × 1.′′1 (PA = 41°). The SVS13-B protostar is also labelled. White dashed circle indicate the primary beam: ~ 55′′. Upper-right panel: zoom-in of the inner SVS13-A region as observed using the SO(4₅ –3₄) emission. Green contours are for the emission in the 3 km s⁻¹ around the systemic velocity. Red-shifted emission maps has been derived by integrating the SO emission from the systemic velocity up to +20 km s⁻¹. Blue-shifted image has been obtained by integrating down to –5 km s⁻¹. First contour and steps are 3σ and 10σ, respectively. The 1σ values are 10 mJy km s⁻¹ (systemic velocity), 13 mJy km s⁻¹ (red), and 11mJy km s⁻¹ (blue). Symbols are as in the left panel. The black cross indicates the positions of the 205 GHz continuum peak (see Fig. 1). The synthesized beam (HPBW) is 0.′′ 65 × 0.′′58 (PA = –46°). Middle-right panel: zoom-in of the inner SVS13-A region as observed using the SO(4₅ –4₄) emission. The whole velocity emitting region has been used (see Fig. 3). First contour and steps are 3σ (9 mJy km s⁻¹) and 10σ, respectively. Symbols are as in the left panel. The synthesized beam (HPBW) is: 1.′′ 6 × 1.′′1 (PA= 41°). Bottom-right panel: zoom-in on the inner SVS13-A region as observed using the ³⁴SO(2₃–1₂) emission. First contour and steps are3σ (12 mJy km s⁻¹) and 10σ, respectively. Symbols are as in the left panel. The synthesized beam is the same as in the middle-right panel.