Magnetic morphology of nonthermal electron precipitation during three flares in a highly nonpotential active region

Abstract

NOAA Active region 5747, during its October 1989 transit across the solar disk, showed highly nonpotential photospheric vector magnetic field structure and produced many solar flares, three of which we observed at Mees Solar Observatory. After resolution of the 180° ambiguity, we determined the photospheric distribution of the vertical current density. We then compared the locations of the major current systems to sites of nonthermal electron precipitation inferred from Hα profiles of three flares observed using the Mees CCD Imaging Spectrograph. We found that the sites of energetic electron precipitation are at the edges of these currents, not at their peaks.