Histograms of the values of the calculated FP coefficients a (top), b (middle), and c (bottom). In each panel the histogram of the coefficient (blue line), the average value (vertical black line), and the median (vertical red line) are shown. In the case of the b coefficient, which does not depend on β, the average and the median are the same (the black and red vertical lines coincide). The dashed gray regions give the intervals of the FP coefficients found by fitting the distribution of ETGs in the log(σ)−log(I_e)−log(R_e) space.