Position-velocity maps of molecular line emission from the central region of Centaurus A, in position angle 125° counter-clockwise from north (data summarised in Tables 2 and 3). Horizontal scales are velocity V(LSR) in   km   s^-1, vertical scales are offsets from the nucleus in arcsec. The panels on the left show emission from   ¹²CO; the J = 1–0, J = 2–1, and J = 3–2 transitions are shown from top to bottom, respectively. The panels on the right show emission from   ¹³CO (J = 1–0 at the top, J = 2–1 in the middle). The J = 1–0 HCN transition is at bottom right. The J = 1–0 maps have resolutions of 45′′−55′′, all other maps have an effective resolution of 23′′. In all three   ¹²CO maps, the contours are at multiples of 50 mK in main-beam brightness temperature. In the   ¹³CO maps contours are at multiples of 5 mK (J = 1–0) and 10 mK (J = 2–1). The HCN map contours are at multiples of 5 mK. Strong absorption is clear in all panels near V_LSR = 550     km   s^-1. Emission from the rapidly rotating compact nuclear disk becomes progressively more clear with increasing J-transition in the   ¹²COpanels, and in the HCN map.