Radio emission of coronal shock waves

Abstract

The "backbone" emission of shock initiated coronal (metric) type II solar radio bursts is considered. The source has extremely narrow bandwidth and appears to be stationary in relation to the shock. The increasingly complete understanding of the phenomena associated with the Earth's bow shock is tapped for suggestions on the responsible particles, their energies and the emission mechanism of radio waves. The authors propose that the radiation originates from electrons and ions of a few keV energy, the dominant populations of accelerated particles upstream of the bow shock. A model is developed which can explain the major observed features by wave-wave coupling between electron plasma waves themselves and with ion waves. Observational tests at interplanetary and bow shock waves are proposed.