PV diagrams from the ¹²CO(3−2) ALMA cube a) along the central velocity gradient (PA = 140°) and b) perpendicular to the central velocity gradient (PA = 50°). The color-bar shows the flux density in [Jy beam^-1]. The position of the cuts is displayed in Fig. 4c. The white rectangle marks the nuclear region in which the central velocity gradient is dominant. (a1) to (b3) mark dust arm positions: (a1) eastern arm, (a2) southern arm, (a3) nuclear arm, (a4) northern arm, (b1) overlap between eastern and southern arm, (b2) nuclear arm, (b3) southern arm (west).