Channel maps of the ²⁸SiO v = 2 J = 5–4 line emission. The contours in each channel are 3, 6, 9, 12, 15, 18, 21 and 24 times the rms noise in the peak line channel (0.065 Jy beam^-1). Every channel is 2.5 km s^-1 wide and the central LSR velocity is indicated in the lower right corner of each box. In the central channels, the SiO emission is unresolved and peaks at the position of Source I (pink star symbol), probably tracing the inner parts of the outflow associated with Source I (as the ²⁸SiO v = 1 transition). In addition, strong diffuse emission is evident away from the systemic velocity blending the SiO line, that we attribute to CH₃CH₂CN, CH₃CH₂CHO and CH₃OCH₃. The ALMA synthesized beam is indicated as a white ellipse in the lower left panel.