Simulation on solar type II radio bursts associated with corona mass ejections

Laboratory for Plasma Astrophysics, Faculty of Engineering, Toyama University, 3190 Gofuku, Toyama, 930-8555, Japan e-mail: sakaijun@eng.toyama-u.ac.jp

Received: 10 March 2005
Accepted: 15 June 2005

Abstract

The wave emission process of solar type II radio bursts associated with Coronal Mass Ejections (CME) is investigated by using two-dimensional, electromagnetic, relativistic Particle-In-Cell (PIC) code. Two simulation results are shown: the first case where the CME propagates perpendicular to the local magnetic field, and the second case where the CME propagates obliquely to the local magnetic field showing two cases of the propagation angle of 80 and 40 degrees. We show that a fast magnetosonic shock wave is formed with both protons and electrons accelerated by the surfatron acceleration mechanism. From the first case we show that the electron Bernstein waves are generated near the shock front and can be converted to extra-ordinary electromagnetic waves (type II radio bursts) through direct linear mode conversion. It is found from the second case that the electrostatic Langmuir waves (Z-mode) are generated near the shock front and can be also converted in extra-ordinary electromagnetic waves through direct linear mode conversion.