Position velocity (pV) diagrams (continuum subtracted) for IC 860 (left) and Zw049.057 (right) where the x-axis shows the radial velocity (relative to cz = 3880km s^-1 and 3900 km s^-1 respectively) and the y-axis shows the position along the major axis (for both galaxies the position angle is –20°). The upper panel shows the HCN, the centre the HCN-VIB and the lower panel the HCO⁺ pV diagrams. The contours are 3.5 × (1,3,5,7,9,11,13) mJy beam^-1 (IC 860) and 3.5 ×  (1, 3, 5, ... 17) mJy beam^-1 (for Zw049.057). The colour ranges from 2 to 30 mJy beam^-1. The white vertical dashed line indicate the systemic velocity. The horizontal white line indicates the nuclear position of the HCN-VIB line.