Test particle acceleration in a numerical MHD experiment of an anemone jet^*

¹ CRAL - Observatoire de Lyon, 9, avenue Charles Andre, 69561 Saint Genis Laval Cedex, France
² Niels Bohr Institute, Blegdamsvej 17, 2100 Copenhagen Ø, Denmark e-mail: kg@astro.ku.dk

Received: 23 October 2009
Accepted: 23 December 2009

Abstract

Aims. To use a 3D numerical MHD experiment representing magnetic flux emerging into an open field region as a background field for tracing charged particles. The interaction between the two flux systems generates a localised current sheet where MHD reconnection takes place. We investigate how efficiently the reconnection region accelerates charged particles and what kind of energy distribution they acquire.

Methods. The particle tracing is done numerically using the Guiding Center Approximation on individual data sets from the numerical MHD experiment.

Results. We derive particle and implied photon distribution functions having power law forms, and look at the impact patterns of particles hitting the photosphere. We find that particles reach energies far in excess of those seen in observations of solar flares. However the structure of the impact region in the photosphere gives a good representation of the topological structure of the magnetic field.