Energy distribution of non-thermal particles injected into the JET and ISM regions for different assumed values of the low-energy cutoff . Particle injection is discretized as occurring every t_inj = 1 kyr (dotted lines). The final cumulative distribution at present time accounts for radiation cooling due to IC on the CMB and synchrotron losses. Distributions are shown for particles injected recently (t_inj ≤ 1 kyr) that diffuse through the JET region (blue lines), and particles injected at t_inj > 1 kyr diffusing into the ISM region (in red lines). In both cases, a magnetic field of B_ISM = B_JET = 5 μG is assumed. A low cutoff for the particle distribution at injection is considered, adopting two different values and (solid and dashed lines, respectively). A high energy cutoff is also assumed in all cases. The distribution normalization is computed accounting for the source observed X-ray luminosity (see text for details).