Characteristics of a type II solar radio burst on 22 March 1998

A solar radio type II burst (which was seen as two patches of emission, one during 07:00-07:13 UT and other one during 07:20-07:35 UT) was observed on 22 March 1998 using the Madurai radio spectrograph. A broad range of data (from Culgoora and Hiraiso spectrographs, white-light data from SOHO/LASCO and X-ray data from Yohkoh and GOES satellites) was also studied for this e vent, which was analyzed in comparison with these supplementary data. In ad dition, the conditions associated with this shock were analyzed quantitativ ely. From the above investigations, the following conclusions have been mad e. The temporal relationship between H-alpha flare and burst has shown that the active region AR 8185 is the source of this type II burst. A bright fr ont feature observed with LASCO is also associated with this type II burst and active region AR 8185. The time profile of the shock derived from the f irst patch of this type II burst coincides with the flare starting time. Al so, within error limits, the start time of the CME is same as the flare. He nce, it is not possible to decide whether the type II originated in the fla re or was driven by CME. In addition, the investigations of the second patc h alone has provided the following results. The inferred shock speed for th e second patch of emission is lower than the first and closer to the CME sp eed. The emission occurred below 50 MHz. These conditions imply that this p atch may be a separate burst which might have been produced by the CME alon e.