Abstract

Contributed Talk - Splinter NonThermalAccel   (MW-1250)

Particle Acceleration and Emission Signatures in Relativistic large-scale AGN Jets

Nikita, Frank Rieger, Frank Jenko
Max Planck Institute for Plasma Physics

Author: Nikita Nikita Co-authors: Frank Rieger, Frank Jenko Relativistic jets from active galactic nuclei (AGNs) are among the most energetic phenomena in the universe, extending over kilo-parsec scales. These jets develop complex structures through different MHD instabilities and turbulence, which strongly influence non-thermal particle acceleration in these systems. In this work, we explore jet-driven turbulence as a site for stochastic (second-order Fermi) acceleration in regimes where strong shocks are absent and magnetization is sufficiently high for stochastic processes to dominate. We develop a semi-analytical framework to model turbulent acceleration, investigating how different prescriptions for momentum diffusion coefficients and particle escape timescales influence energy gain and resulting particle spectra. Our preliminary results from solving the particle transport equation show that stochastic acceleration can efficiently energize particles to X-ray-emitting energies. These high-energy particles can subsequently produce even higher-energy emission via Inverse Compton processes. This framework is highly relevant for interpreting the high-energy emission observed from large-scale jets in nearby radio galaxies such as M87 and Centaurus A. By coupling our acceleration model with numerical simulation and synthetic synchrotron emission, we aim to examine how variations in diffusion physics translate into observable signatures in AGN jets. This approach provides new constraints on the microphysical processes governing particle acceleration in large-scale relativistic outflows.