Position-velocity diagram of ¹³CO J = 6–5 at 661.067 GHz for a slit width of 101 pixels at a position angle (PA, measured from north to east) of (top left) 90° (i.e., along the right ascension; offset to the east is negative, and to the west positive), (top right) 0° (i.e., along the declination; offset to the north is negative and to the south positive), (bottom left) 10°, and (bottom right) 22.5°.