Radio emission from the solar corona due to shock waves.

The slowly drifting solar type II radio bursts are believed to be due to the flare associated shock waves propagating radially outward in the corona. The main observational characteristics of these bursts show that the shocks responsible are supercritical and quasiperpendicular. The electrons accelerated through reflected-ion-beam-excited low frequency waves form gap distributions by getting scattered on whistlers and they fill a large volume just in front and behind the shock front rise to the backbone emission. The electrons accelerated by fast Fermi process form electron beam escaping from the shock front and give rise to herringbone emission. The brightness temperatures, polarization and frequency splitting are self consistently explained.