Intensity weighted velocity (moment 1) map and integrated intensity contours of HCN taken over the velocity ranges 0−80, 80−160, and 160−240 km s⁻¹ from the systemic velocity (∼4000 km s⁻¹) on the red- (solid) and blueshifted (dashed) sides in IRAS 17578-0400. Velocity contours are given every 30 km s⁻¹. Integrated intensity contours start at 0.16, 0.20, and 0.16 Jy beam⁻¹ km s⁻¹ (5σ) for the three velocity intervals, respectively, and increase by factors of 2.