Measurements of flux density integrated from the selected regions of J1528+0544 along with the best fit JP models (solid lines) and extrapolated power-law spectra (dashed lines) with injection index α_inj = 0.39 (Table 1) plotted on a logarithmic scale. The ages of the regions are given in the plot legend. To separate the plots, the data points along with uncertainties and the best fit spectra were rescaled by factors of 0.35 and 1.5 for the 25 Myr and the 12 Myr regions respectively.