2002A&A...395L..21H

We demonstrate that the ``sub-Keplerian'' rotation curve of maser spots in NGC1068 can be explained by the gravitational attraction of the disc orbiting the central black hole. Possible parameters matching observations are: black hole mass ≃(1.2±0.1)x10⁷M_☉, disc outer edge >1.3pc, aspect ratio 3x10^–3≲(H)/(R)≲0.3, surface density Σ∝R^{–1.05±0.10}, and disc mass ≃(9.4±1.6)x10⁶M_☉. The physical conditions required for the excitation of masers are fulfilled, and the outer disc would stand in a gravitationally marginally stable state.