Integrated intensity maps of CO for different velocity regimes overlaid on Band 6 continuumin grayscale for SMM1-a. The emission is integrated over the velocities listed in Table 2. The synthesized beam of the CO (red) and continuum (black) is presented in bottom-left corner of EHV plot. The synthesized beam size of the continuum images is 0.′′35 × 0.′′33 and 0.′′55 × 0.′′45 for CO map. The contours are [3, 6, 9, 15, 20, 40] times the rms value. The rms values for each velocity channel, which are blueshifted and redshifted in K km s⁻¹, are slow [18.8, 20.5], fast[5.8, 7.2], EHV [2.0, 2.8].