Rotational diagram for the lines of r-SiC₃. The blue line correspond to a fit to all transitions with energy of their upper level lower than 50 K. The purple one corresponds to the fit to all data with upper level energies above 50 K. The dashed red line corresponds to a global fit to all the data and represents an averaged temperature and column density. The data for each K_a is represented by the same color (black for K_a = 0, green for K_a = 2, cyan for K_a = 4 and blue for K_a = 6.