Type II solar radio emission - A self-consistent approach

Abstract

An attempt is made to construct a self-consistent model for type II radio bursts. It is proposed that a majority of the type II shocks are super-critical and the reflected ions from such type II shock fronts are described by the drifted Maxwellian in the upstream and by the Dory-Guest-Harris distribution in the downstream. The low-frequency waves excited by these ions accelerate electrons resonantly along the field lines both in the upstream as well as in the downstream, which are responsible for the lower-frequency and upper-frequency bands in the dynamic spectrum of a type II radio burst. The functional behaviour of the distribution functions of the accelerated electrons is the same in both the cases whereas the number densities of the accelerated electrons in the downstream is smaller than that in the upstream.