IRAM PdBI continuum-subtracted maps of the CN(1–0) line emission. From left to right: (i) total emission integrated between −800 <  v [km s⁻¹]< 1600, where velocities are calculated with respect to the J = 3/2−1/2 spingroup (Table 1); (ii) blue wing of the J = 3/2−1/2 line (−500 <  v [km s⁻¹]<  − 300); (iii) red wing, integrated between 108.372 < ν_obs[GHz] < 108.463, corresponding to velocities 300 <  v [km s⁻¹]< 550 with respect to the central frequency of the fainter J = 1/2−1/2 spingroup (where the red line wing is not affected by blending). All maps are corrected for the primary beam (45.6″ FWHM) and show the central 25″ × 25″ region. The synthesised beam is reported in the bottom left corner of the maps. Negative contours (dashed lines) correspond to (−6σ, −3σ, −2σ), and positive contours (solid lines) correspond to (2σ, 3σ, 6σ, 9σ, n × 12σ), with n = 1, 2, etc., where σ is the rms of the cleaned datacube (see Table 1).