HARD X-RAY OBSERVATIONS OF HIGH CORONAL REGIONS IN SOLAR FLARES

摘要

Using Hard X-ray data obtained from the Hard X-ray Telescope (HXT) onboard Yohkoh I have studied coronal sources in three limb flares, including one particularly interesting event on April 23 1998. The results for the April flare show: (1) the existence of an extended source located in the high corona (～5000 km), and (2) dominant thermal and other sources do not come from the same looptop region. Preliminary results for the other two flares are also discussed.