Spatial distribution (contours and colour) of the SVS13-A region obtained using different SO₂, and ³⁴SO₂ line emission (see Table 1). Angular offset are respect to the phase centre (see Sect. 3). The whole velocity emitting region has been used (from 0 km s⁻¹ to +20 km s⁻¹, see Fig. 7). The SO₂(11_2,10–11_1,11) profile has been deblended by the CH₃OCHO line fitting the profile with two Gaussians (see Table 1). First contour and steps are 5σ and 10σ, respectively. The 1σ value is: 7 mJy km s⁻¹ for SO₂ (8_1,7–8_0,8 (left panel), 14 mJy km s⁻¹ for SO₂ (11_2,10–11_1,11), SO₂ (18_3,15–18_2,16), and ³⁴SO₂(12_0,12–11_1,11). The filled ellipse shows the synthesized beam (HPBW): 1.′′6 × 1.′′1 (PA = 41°) for the SO₂(8_1,7–8_0,8) maps (left panel), and 0.′′65 × 0.′′58 (PA= –46°) for the other images. The black crosses indicate the positions of the VLA4A and VLA4B sources as imaged using the VLA array by Tobin et al. (2018).