HR: 0800h
AN: SH41A-0309 [Abstracts]
TI: Statistics of Hot Plasmas in M/X Flares Using RHESSI Fe & Fe/Ni Line and Continuum Observations
AU: * Caspi, A
EM: cepheid@ssl.berkeley.edu
AF: Department of Physics, University of California, Berkeley, CA 94720-7300, United States
AU: * Caspi, A
EM: cepheid@ssl.berkeley.edu
AF: Space Sciences Laboratory, University of California, Berkeley, CA 94720-7450, United
States
AU: Krucker, S
EM: krucker@ssl.berkeley.edu
AF: Space Sciences Laboratory, University of California, Berkeley, CA 94720-7450, United
States
AU: Lin, R P
EM: rlin@ssl.berkeley.edu
AF: Department of Physics, University of California, Berkeley, CA 94720-7300, United States
AU: Lin, R P
EM: rlin@ssl.berkeley.edu
AF: Space Sciences Laboratory, University of California, Berkeley, CA 94720-7450, United
States
AB:
Observations by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) have shown that
"super-hot" (T > ~30~MK) thermal plasmas are a somewhat common feature of (large) flares of GOES
class M or X. However, the origins and evolution of such super-hot plasmas are still poorly understood. RHESSI
observes solar photons >3 keV with a spectral resolution of ~1~keV FWHM, and is especially sensitive to
flare plasmas hotter than ~10~MK. RHESSI's rich data set allows an unprecedented level of analysis of
thermal flare plasma through imaging and spectroscopic observations of the thermal bremsstrahlung continuum
and the Fe and Fe/Ni line complexes at ~6.7 and ~8~keV. Accurately characterizing the thermal
plasma provides information about flare heating and cooling mechanisms and improves our understanding of
flare energy transport and release. We present early results of a statistical survey of hot thermal plasmas in
~300 RHESSI-observed M/X-class flares (2002-2005), utilizing an analytical method to compare the thermal
continuum and line emission (Caspi & Lin 2007). We present flare energetics, size, and temperature
distributions and discuss the implications for the origins of super-hot thermal plasmas.
UR: http://sprg.ssl.berkeley.edu/~cepheid/agu2007/
DE: 7509 Corona
DE: 7519 Flares
DE: 7554 X-rays, gamma rays, and neutrinos
DE: 7594 Instruments and techniques
DE: 7599 General or miscellaneous
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Fall Meeting