N.V. Nitta
Lockheed Martin Solar and Astrophysics Laboratory, Department/ADBS,
B/52, 3251 Hanover Str., Palo Alto, CA 94304, USA
Radio type II bursts show the existence of shock waves and their propagation from the corona to the heliosphere. There seems to be little doubt as to the CME origin of the low frequency (DH and kilometric) part of type II bursts, but the origin of metric type II bursts seems to be still unsettled. In a few well-observed events, the co-existence of the DH and metric type II bursts around the same time indicates different origins, but counter examples do exist. In this study, we select a small number of events from the two categories and examine EUV/X-ray and coronagraph images to see if there are different flare/CME relationships.