2024MNRAS.529.4433B

We consider the broad-band spectral energy distribution of the high-energy-peaked blazar Mkn 501 using Swift-XRT/UVOT, NuSTAR and Fermi-LAT observations taken between 2013 and 2022. The spectra were fitted with a one-zone leptonic model using synchrotron and synchrotron self-Compton emission from different particle energy distributions such as a broken power law, log-parabola, as well as distributions expected when the diffusion or the acceleration time-scale are energy-dependent. The jet power estimated for a broken power-law distribution was ∼10⁴⁷(10⁴⁴) erg s^–1 for a minimum electron energy γ_min ∼ 10(10³). However, for electron energy distributions with intrinsic curvature (such as the log-parabola form), the jet power is significantly lower at a few times 10⁴² erg s^–1 which is a few per cent of the Eddington luminosity of a 10⁷ M_⊙ black hole, suggesting that the jet may be powered by accretion processes. We discuss the implications of these results.