New Insights on the Origin of Cosmic Rays

  • Date June 18, 2015
  • Hour 3 pm
  • Room Main Lecture Hall
  • Speaker Damiano Caprioli (Princeton University)

I present the results of large kinetic simulations of particle acceleration at non-relativistic collisionless shocks, which allow a first-principles investigation of cosmic ray (CR) acceleration at supernova remnants' shocks.
Ion and electron acceleration efficiency and magnetic field amplification are investigated in detail as a function of shock inclination and strength, and compared with predictions of diffusive shock acceleration theory.
Moreover, I outline an original mechanism (the "espresso mechanism") for the acceleration of nuclei up to 10^20eV in the relativistic jets of powerful active galactic nuclei. The combination of the supernova paradigm for the origin of Galactic CRs and the espresso mechanism provides a unified description of the global CR spectrum and chemical composition over more than 11 orders of magnitude in energy.