Radio evidence for electron acceleration by transverse shock waves in herringbone type II solar bursts

The authors describe six Type-2 solar radio bursts containing herringbone structure in which the tangential source motions observed are consistent with previous observations that the unusually slow drift rates of Type-2 bursts containing herringbone structure can be explained if the shock waves propagate more or less transverse to open magnetic field lines in the corona thus allowing the electrons to escape along the field lines and produce the herringbone features. However, the high source brightness temperatures and second harmonic polarization of the herringbones are difficult to reconcile with existing theoretical interpretations