Channel maps of the ¹²CO J = 3−2 line emission toward M 2–9. The center is given by the position of compact continuum emission, here subtracted, at J2000 coordinates RA = 17:05:37.966, Dec = −10:08:32.63. The LSR velocities are specified in the top left corner of each panel. Contours are shown from 4 ×σ with a spacing of 15 ×σ (where the root-mean-square noise is 2 mJy beam^-1, which corresponds to 0.66 K in Rayleigh-Jeans-equivalent T_MB units) as a white solid line, and at −4 ×σ as dashed red lines. The synthesized beam is 0.̋19 × 0.̋16 with the major axis PA = 116°, and is drawn in the bottom right corner of the last panel. More details can be found in Sect. 3.