A&A 432, 1049-1056 (2005)
Quiet time particle acceleration in interplanetary spaceF. Lepreti1, H. Isliker1, K. Petraki1, 2 and L. Vlahos1
1 Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
2 Department of Physics and Astronomy, UCLA, Los Angeles, California 90095, USA
(Received 16 July 2004 / Accepted 8 November 2004)
We propose a model for the acceleration of charged particles in interplanetary space that appear during quiet time periods, that is, not associated with solar activity events like intense flares or coronal mass ejections. The interaction of charged particles with modeled turbulent electromagnetic fields, which mimic the fields observed in the interplanetary medium, is studied. The turbulence is modeled by means of a dynamical system, the Gledzer-Ohkitani-Yamada (GOY) shell model, which describes the gross features of the Navier-Stokes equations. The GOY model is used to build a 3D velocity field, which in turn is used to numerically solve the ideal magneto-hydrodynamic (MHD) induction equation, while the electric field is calculated from the ideal Ohm's law. Particle acceleration in such an environment is investigated by test particle simulations, and the resulting energy distributions are discussed and compared to observations of suprathermal electrons and ions during quiet periods in interplanetary space.
Key words: acceleration of particles -- turbulence -- Sun: solar wind -- interplanetary medium
© ESO 2005