HR: 1340h
AN: SH13A-0287    [Abstracts]
TI: Hard X-ray Emissions From The Legs of Flaring Loops
AU: * Liu, W
EM: weiliu@sun.Stanford.EDU
AF: Stanford University, Department of Physics, Stanford University, Stanford, CA 94305-4060 United States
AU: Liu, S
EM: Siming.Liu@stanford.edu
AF: Stanford University, Department of Physics, Stanford University, Stanford, CA 94305-4060 United States
AU: Jiang, Y
EM: arjiang@stanford.edu
AF: Stanford University, Department of Physics, Stanford University, Stanford, CA 94305-4060 United States
AU: Petrosian, V
EM: vahe@astronomy.Stanford.EDU
AF: Stanford University, Department of Physics, Stanford University, Stanford, CA 94305-4060 United States
AB: or the first time in the RHESSI era, Liu et al. (2005) reported hard X-ray emissions coming from the legs of a flaring loop at intermediate energies, as opposed to the commonly observed looptop (LT) and footpoint (FP) emissions. In an M-1.7 flare observed by RHESSI on November 13, 2003, we found that the FPs in the 9-20 keV energy range rose up to the legs and eventually merged at the LT, suggestive of a gradual density enhancement in the loop possibly caused by chromospheric evaporation. We identified several flares with similar behavior and analyzed their images, spectra, and imaging spectroscopy, in an effort to better understand the nature of the leg emissions. We will present the results of our data analysis of all such flares and discuss their implications for the particle acceleration and other theoretical aspects of flares such as chromospheric evaporation. The work is supported by NASA grants NAG5-12111, NAG5 11918-1, and NSF grant ATM-0312344 at Stanford University.
DE: 7507 Chromosphere
DE: 7509 Corona
DE: 7519 Flares
DE: 7554 X-rays, gamma rays, and neutrinos
SC: SPA-Solar and Heliospheric Physics [SH]
MN: Fall Meeting 2005