The Phoenix Fire Model for Jet Creation: The Role of Magnetic Fields in the Production and Propagation of Relativistic Jets

Using recent observational and theoretical results, I outline the latest ideas on how relativistic jets are produced by rotating magnetic fields, along with the physical processes that result in the FR I/II dichotomy. Simply put, at the end of the acceleration and collimation phase the now super-magnetosonic jet (the “Phoenix”) passes through a master recollimation shock (the “fire”) and is reborn as a new and more stable collimated MHD flow. Depending on whether the magnetic dissipation in the shock is negligible or substantial, the final jet will be either trans-magnetosonic (a BL Lac/FR I source) or super-(magneto)sonic with a weak magnetic field (an FSRQ/FR II source). Predictions are made about the behavior of additional observational and theoretical studies that can test this hypothesis more completely