Fermi Acceleration in Magnetic Reconnection Sites

Type Conference Paper
Names E. M. de Gouveia Dal Pino, G. Kowal, A. Lazarian
Conference Name 8th International Conference of Numerical Modeling of Space Plasma Flows (ASTRONUM 2013)
Place eprint: arXiv:1401.4941
Volume 488
Pages 8
Date September 1, 2014
ISBN 1050-3390
URL http://adsabs.org/2014ASPC.488.8D
Library Catalog adslabs.org
Abstract The mechanisms that accelerate cosmic relativistic particles are not fully understood yet. A variety of processes has been investigated and the acceleration in magnetic reconnection sites has lately gained increasing attention from researchers not only for its potential importance in the solar system, but also beyond it, in astrophysical environments like compact stellar sources, AGNs and GRBs, and even in diffusive magnetized media as the interstellar medium (ISM) and the intergalactic medium (IGM). In this talk we review this process and, supported by three-dimensional MHD simulations with the injection of thousands of test particles, we show that they can be efficiently accelerated by magnetic reconnection through a first-order Fermi process within large scale magnetic current sheets, even in a collisional fluid (contrary to what was previously believed), especially when local turbulence is present which makes reconnection fast, the acceleration layer thicker and the overall process naturally three-dimensional. Tests of particle acceleration in pure MHD turbulent environments (i.e., without the presence of large scale current sheets), on the other hand, indicate that the dominant acceleration process is a second-order Fermi.
UW-Madison Astronomy Home