(a) Rotational and (b) radial velocity components of the gas along the four outer circles (r = 1″ − 3″) depicted in Figs. 15a–c, as derived from the CO (2–1) PV diagrams of Figs. 15d–g. (c) The rate at which gas mass is crossing the quoted circles per unit interval of PA. The PA of the bar is indicated with cyan vertical lines, and the vertical long and short arrows indicate the PA of the MKA and mKA, respectively. Values of V_rad and dṀ/dPA positive (negative) indicate gas flowing in the outward (inward) direction.