Top panels: combined A+B moment maps of the HCN 3−2 line emission from the main disk (as defined in the text). Left panel: integrated intensity with contour levels 0.5 × (1,2,4,8,16,32) Jy beam^-1 km s^-1 and grey (colour) scale ranging from 0 to 15 Jy beam^-1 km s^-1 (peak integrated flux is 22 Jy beam^-1 km s^-1). Centre: velocity field with contour levels starting at − 56 km s^-1 and then increasing by steps of 18.8 km s^-1 until +38 km s^-1. The grey (colour) scale ranges from − 65 to 50 km s^-1. Right: dispersion map where contours start at 30 km s^-1 and then increase by steps of 30 km s^-1. Greyscale ranges from 0 to 115 km s^-1 and peak dispersion is 130 km s^-1. The cross marks the position of the peak HCN 3−2 integrated intensity. Lower panels: combined A+B moment maps of the HCO⁺ 3−2 line. Left panel: integrated intensity with contour levels 0.5 × (1,2,4,8,16,32) Jy beam^-1 km s^-1 and grey (colour) scale ranging from 0 to 15 Jy beam^-1 km s^-1 (peak integrated flux is 12 Jy beam^-1 km s^-1). Centre: velocity field with contour levels starting at − 56 km s^-1 and then increasing by steps of 18.8 km s^-1 until +38 km s^-1. The grey (colour) scale ranges from − 65 to 50 km s^-1. Right: dispersion map where contours start at 30 km s^-1 and then increase by steps of 30 km s^-1. Greyscale ranges from 0 to 115 km s^-1 and peak dispersion is 98 km s^-1. The cross marks the position of the peak HCN 3−2 integrated intensity. (In the online version of this figure the greyscale is replaced with a rainbow color scale ranging from dark blue to red.)