[C II] 158-μm observations and modelling of AzTEC/C159. Top left panel: HST F814W image with the [C II] 158-μm total-flux map contours overlaid; the source is not detected by HST. Top middle panel: total-flux map (green shape and black contours) of the [C II] 158-μm emission; the lowest contour is at about 2.5 times the rms noise in this map, and the other contours are at 2, 4, and 8 times this level. In red we show the outer contour of the total-flux map of the model obtained with ^3DBAROLO (convoluted with the observational beam, shown in the bottom left corner). Top right panel: velocity (weighted-mean) field of the [C II] 158-μm line. Bottom left panel: position-velocity diagram along the kinematic major axis of the galaxy (grey line across the velocity field); the data are in green shades and contours, while the best-fit ^3DBAROLO model is in red contours. Contour levels are at −2, 2, 4, and 8 times the rms noise per channel. Bottom centre panel: position-velocity diagram along the kinematic minor axis of the galaxy displayed analogously to the major-axis plot. Bottom right panel: velocity (weighted-mean) field of the best-fitting ^3DBAROLO model.