Speaker
Damiano Caprioli
(Princeton University)
Description
The origin of cosmic rays (CRs) has puzzled scientists since the pioneering discovery by Victor Hess in 1912. In the last decade, however, modern supercomputers have opened a new window on the processes regulating astrophysical collisionless plasmas, allowing the study of CR acceleration via first-principles kinetic simulations; at the same time, new generations of X-ray and gamma-ray telescopes have been collecting evidence that Galactic CRs are accelerated in the blast waves of supernova remnants (SNRs).
I present state-of-the-art particle-in-cells simulations of non-relativistic shocks, in which ion and electron acceleration efficiency, and magnetic field amplification, are studied in detail as a function of the shock parameters. I then discuss the theoretical and observational counterparts of these findings, comparing them with predictions of diffusive shock acceleration theory, and with multi-wavelength observations of young SNRs; I especially outline some major open questions, such as the (possible) causes of the steep CR spectra inferred from gamma-ray observations of SNRs, and the origin of the knee in the Galactic CR spectrum. Finally, I put such a theoretical understanding in relation with CR propagation in the Galaxy, in order to bridge the gap between acceleration in sources and measurements of CRs at Earth.
| Registration number following "ICRC2015-I/" | 1074 |
|---|---|
| Collaboration | -- not specified -- |
Primary author
Damiano Caprioli
(Princeton University)
