Azimuthally averaged CO(3−2) emission, around the position of SSC B1 up to a maximum radius of 1.̋8. The left panel shows the total emission and the right panel shows the emission clipped up to a maximum value of 20% of the peak emission. The semi-ellipse in dashed-red line highlights the expanding shell assuming a central velocity of ~1565 km s^-1 marked with a red tick on the velocity axis, while for the dashed-cyan line, the central velocity is equal to that of the Brγ emission.