HR: 11:05h
AN: SH52C-04    [Abstracts]
TI: HINODE and RHESSI Observations of Partially Occulted Solar Flares
AU: * Krucker, S
EM: krucker@ssl.berkeley.edu
AF: Space Science Laboratory, 7 Gauss Way, Berkeley, CA 94720-7450, United States
AU: Hannah, I G
EM: hannah@ssl.berkeley.edu
AF: Space Science Laboratory, 7 Gauss Way, Berkeley, CA 94720-7450, United States
AU: Lin, R P
EM: rlin@ssl.berkeley.edu
AF: Space Science Laboratory, 7 Gauss Way, Berkeley, CA 94720-7450, United States
AB: We present X-ray imaging and spectral observations of a series of partially occulted solar flares observed by HINODE/XRT and RHESSI on November 21, 2006. Despite that the footpoints of the flare loops are occulted, non-thermal hard X-ray emissions from flare-accelerated electrons are observed in all of these flares. Although the non-thermal emissions are faint, their spectra are rather flat/hard with power law indices between ~4 and ~5. All events look similar with a simple thermal loop seen at the limb that rises slowly (~10 km/s) during the impulsive phase. The non-thermal emission can only be imaged when averaged in time over the impulsive phase, but it originate from a similarly sized loop. Compared at the same time, the non-thermal loop is about 1500 km higher up than the thermal loop. However, the location of the non-thermal loop seen in the impulsive phase is about at the same altitude as the thermal loop seen at the soft X-ray peak time. These observations are consistent with the standard flare model where flare-accelerated electrons produce faint non-thermal hard X-ray emissions in flare loops (thin target emission) and then lose their energy in the footpoints of these loops and heat chromospheric plasma. Evaporation of heated chromospheric plasma then fills up the flare loops earlier seen in non-thermal hard X-rays and makes it visible in thermal X-ray emission.
DE: 7509 Corona
DE: 7519 Flares
DE: 7526 Magnetic reconnection (2723, 7835)
DE: 7554 X-rays, gamma rays, and neutrinos
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Fall Meeting