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Session 70 - Solar Flares and Ejections.
Display session, Thursday, June 13
Tripp Commons,

[70.12] Plasma Heating at the Onset of Solar Flares

S. Savy (Institute of Space and Astronautical Science)

An analysis of 50 flares observed with the Yohkoh satellite is presented. These events were selected on the basis of completeness of Yohkoh HXT, BCS, and SXT data. In addition, BATSE data was used to supplement the high energy coverage of HXT in some cases. The spatial and spectral characteristics of the hard X-ray and soft X-ray sources at onset are compared with the observed heating during the main phase of the flares. The extent of the Neupert effect in each case was evaluated.

In a number of events the early hard X-ray spectrum was extremely soft in comparison to the later main burst and exhibited a different spatial structure. Spectral analysis of the X-ray data are used to place limits on the nature of the hard X-ray emission at onset, and the results are discussed with regard to models of energy release and recent findings purporting to show magnetic reconnection sites in a number of solar flares.

Program listing for Thursday