Measurements of flux density integrated from the regions used for the spectral aging analysis (see Figures 3, 4, and 5) along with the best fit continuous injection models plotted on a logarithmic scale. The best fit injection indices α_inj are given in Table 1. To separate the plots in the J1021+1216 panel, the data points along with uncertainties and the best fit spectra of the eastern and western inner lobe were multiplied by 0.2 and 0.1, respectively.