Astrophysical Reconnection and Particle Acceleration

TL;DR

This paper discusses how turbulence influences magnetic reconnection in astrophysical environments and how this process can efficiently accelerate particles through the first order Fermi mechanism, supported by new numerical results.

Contribution

It presents new numerical results on particle acceleration in turbulent reconnection and compares this mechanism to acceleration in turbulent media.

Findings

Reconnection becomes fast and turbulence-dependent in astrophysical settings.

Turbulent reconnection can efficiently accelerate particles via the first order Fermi process.

Numerical simulations support the role of turbulence in enhancing particle acceleration.

Abstract

Astrophysical reconnection takes place in a turbulent medium. The turbulence in most cases is pre-existing, not caused by the reconnection itself. The model of magnetic reconnection in Lazarian & Vishniac (1999) predicts that in the presence of turbulence the reconnection becomes fast, i.e. it is independent of resistivity, but dependent on the level of turbulence. Magnetic reconnection injects energy into plasmas through a turbulent outflow from the reconnection region and this outflow can enhance the level of turbulence creating bursts of reconnection. Magnetic reconnection in the presence of turbulence can accelerate energetic particles through the first order Fermi mechanism, as was discussed in Gouveia dal Pino & Lazarian (2005). We discuss new numerical results on particle acceleration in turbulent reconnection, compare the acceleration arising from turbulent reconnection to the acceleration of energetic particles in turbulent medium.