HR: 1340h
AN: SH53A-1055    [Abstracts]
TI: What is There Before a Flare?
AU: * Hudson, H S
EM: hhudson@ssl.berkeley.edu
AF: SSL/UCB, 7 Gauss Way, Berkeley, CA 94720-7450, United States
AU: Hannah, I G
EM: hannah@ssl.berkeley.edu
AF: SSL/UCB, 7 Gauss Way, Berkeley, CA 94720-7450, United States
AU: Krucker, S
EM: krucker@ssl.berkeley.edu
AF: SSL/UCB, 7 Gauss Way, Berkeley, CA 94720-7450, United States
AU: Watanabe, K
EM: kwatana@ssl.berkeley.edu
AF: SSL/UCB, 7 Gauss Way, Berkeley, CA 94720-7450, United States
AB: The physical parameters in a coronal volume prior to the occurrence of a flare are generally unknown, but may play an important role in identifying the processes involved in flaring or eruption. Now we have observations from Hinode at very high resolution that can provide the best possible values for preflare temperature and density, for example. We make use of Hinode XRT observations of the preflare magnetic structure with the same footpoint locations as a flaring loop, as identified in RHESSI images. We additionally introduce a method based on conductive equilibrium (RTV scaling) to reduce the uncertainty on estimates of physical parameters due to lack of knowledge of the detailed geometry. Preliminary results are consistent with the finding at lower resolution from Yohkoh: in a majority of cases, the preflare conditions are not observable in soft X-rays. We discuss the upper limits that result, which point to low temperatures, densities, and plasma beta values, but high Alfven speeds. We hope also to be able to extend this conclusion with EIS observations.
DE: 7509 Corona
DE: 7519 Flares
DE: 7554 X-rays, gamma rays, and neutrinos
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Fall Meeting