Example of the method used to determine projected kinematic position angles (PAs) from the velocity maps of the galaxy NGC 36. Leftmost panel shows the SDSS r-band image of the galaxy. White solid line represents the photometric PA measured at the same galactocentric distance as the kinematic PA (PA_morph, measured from the r-band image; see Sect. 3). Dashed line represents the photometric PA measured at the outermost isophotes of the image (PA). Middle-left and middle-right panels show the stellar and ionised gas velocity maps, respectively. Green points highlight the locations where the maximum velocities are located at a given radius, determined from the position–velocity diagram. Black lines for each kinematic side represent the average kinematic PA (PA_kin), while white thin lines along the zero-velocity curve show the average minor kinematic PA. Right panel shows the distance from the galactic centre versus the maximum for the stellar (blue points) and ionised gas (red points) components. The curve along 0 km s^-1 represents the velocities along the zero-velocity curve. The error bars represent the uncertainty in velocity determined from Monte Carlo simulations.