Top panel: comparison between two limiting cases where γ-ray photons are absorbed only on synchrotron photons emitted by secondary pairs (solid line) or by primary electrons (dashed line). The injection compactnesses of γ-rays and primary electrons are (solid line) and (dashed line), respectively. Different parts of the spectra have different power-law dependencies that are marked on the plot. Bottom panel: example of an indermediate case where γ-rays are being partially absorbed on synchrotron photons from secondaries. The injection compactness of primary electrons is , while ℓ_inj takes the following values: 8 × 10^-3 (solid line), 8 × 10^-2 (dashed line), and 8 × 10^-1 (dotted line). The dash-dotted line that is obtained for (same as solid line in top panel) is plotted for comparison reasons. Other parameters used for the plot are: B = 40 G and R = 3 × 10¹⁶ cm.