Velocity centroid map obtained by fitting a Gaussian profile to the C¹⁸O(2–1) spectra. The calculated velocity gradient is overplotted on top of it, using streamplot (https://matplotlib.org/stable/api_as_gen/matplotlib.pyplot.streamplot.html), showing organised motion. The colourbar of this streamplot, located on top of the figure, indicates the magnitude of the velocity gradient at each location. The black circle indicates the beam size of the presented APEX observations and the black crosses indicate the position of the 4 massive fragments.