Speaker
Description
Blazars, among the most extreme classes of active galactic nuclei, are powered by relativistic jets whose energy dissipation mechanisms remain poorly understood. The flat radio spectrum and the core-shift effect trace the spatial distributions of magnetic fields and relativistic particles, while variability encodes dynamical information about dissipation processes. However, a unified framework connecting these observables to the underlying jet physics has been lacking. Here, we present a multi-frequency analysis of the prototypical blazar Mrk 501, incorporating core-shift measurements, spectral energy distributions (SEDs), and power spectral densities (PSDs) within a conical jet model that conserves magnetic power. Our model localizes the emission regions via core-shift data, revealing the profiles of electron density and dissipation rate along the jet. Notably, simulated PSDs at high radio frequencies ($\gtrsim 15$ GHz) deviate from observations, suggesting the presence of fewer but more energetic plasmoids in the inner jet compared to outer regions. This points to distinct dissipation mechanisms operating in the inner and outer jet. Our study establishes a novel approach to probe jet stratification, linking small-scale plasmoid dynamics to global energy transport in relativistic jets.
