Total CO column densities (N) independently calculated from three CO transitions for all regions selected based on the outflow. The x-axis marks the region labels along with their locations around the CND (in brackets), while the y-axis indicates the total CO column densities in the unit of cm⁻². The region code (along the x-axis) and color (the color of the data points) of each region match those in Table 2 and are defined in Sect. 3.2. The legend at the upper-right corner of the plot designates the symbols corresponding to the column densities calculated from three different CO transitions.