Speaker
Description
Feedback by active galactic nuclei (AGN) jets is thought to prevent cooling flows in cool-core galaxy clusters. Cosmic ray electrons are believed to be accelerated at internal shocks in these jets, leading to the synchrotron radio emission observed in radio galaxies and jet-inflated radio lobes. The lobes inflated over multiple AGN feedback duty cycles rise buoyantly in the intra-cluster medium, creating complex morphologies and heating the surrounding gas. We simulate non-thermal radio emission maps of self-regulated AGN jet feedback in isolated cluster simulations. To do this, we follow cosmic ray electron spectra spatially and temporally by solving the Fokker-Planck equation on Lagrangian tracer particles in our magneto-hydrodynamic simulations using the CREST post-processing code. We have implemented a sub-grid model to accelerate cosmic ray protons and electrons at unresolved internal shocks, whereby a fraction of the jet thermal energy is converted to cosmic ray energy with an exponentially decreasing rate. The resulting electron spectrum exhibits a steady-state slope with a decreasing normalization at high momenta, while the rest of the spectrum resembles a freely cooling spectrum. We produce multi-frequency spectra, synthetic radio emission maps and spectral index maps with the CRAYON+ code.
