Intensity-weighted velocity (moment 1) map of the v = 0 J = 5–4 ²⁸SiO line emission with overlaid contours from the v = 0 J = 2–1 ²⁸SiO total intensity (Plambeck et al. 2009). Only pixels with fluxes  > 1 Jy beam^-1 or 4 times the rms noise of the channel with the brightest emission, were used. The white ellipses indicate the positions (Shuping et al. 2004) and approximate sizes (estimated from Shuping et al. 2004) of the infrared sources IRc4, IRc7, IRc11 and IRc12. Source I is marked with a white cross. The newly discovered infrared source SOF1 (de Buizer et al. 2012) is indicated as a circle in the upper left corner. The two white crosses in the blue arc labeled “Goddi” and “Zapata” are the points of interaction between Source I and BN as derived by Goddi et al. (2011a) and Zapata et al. (2009), respectively.