Seminar by Arno Vanthieghem, Princeton
Microturbulence produced by plasma instabilities plays an important role in the dynamics and dissipation mechanisms of relativistic astrophysical blast waves, such as those associated with gamma-ray bursts. Modeling of their afterglow emission bears witness to strong electron heating in the precursor of relativistic Weibel-mediated collisionless shock waves propagating in unmagnetized electron-ion plasmas. We present the tenets of a theoretical model, validated by particle-in-cell simulations, accounting for the electron heating via a Joule-like process through the interplay between pitch-angle scattering in the microturbulence and the coherent electrostatic field induced by the difference in inertia between species. We will then discuss how to extend this model to relativistic radiation-mediated shocks propagating in high-opacity media of importance for the prompt gamma-ray burst emission.
Host: Lorenzo Sironi