HR: 0830h
AN: SP21A-02    [Abstracts]
TI: Transition Region Emission and the Energy Input to Thermal Plasma in Solar Flares
AU: * Holman, G D
EM: holman@stars.gsfc.nasa.gov
AF: NASA's Goddard Space Flight Center, Code 612.1, Greenbelt, MD 20771 United States
AU: Dennis, B R
EM: Brian.R.Dennis@nasa.gov
AF: NASA's Goddard Space Flight Center, Code 612.1, Greenbelt, MD 20771 United States
AU: Haga, L
EM: lhaga@lasp680.gsfc.nasa.gov
AF: NASA's Goddard Space Flight Center, Code 612.1, Greenbelt, MD 20771 United States
AU: Haga, L
EM: lhaga@lasp680.gsfc.nasa.gov
AF: The Catholic University of America, Department of Physics, Washington, DC 20064 United States
AU: Raymond, J C
EM: jraymond@cfa.harvard.edu
AF: Harvard-Smithsonian CfA, 60 Garden Street, Cambridge, MA 02138 United States
AU: Panasyuk, A
EM: apanasyuk@cfa.harvard.edu
AF: Harvard-Smithsonian CfA, 60 Garden Street, Cambridge, MA 02138 United States
AB: Understanding the energetics of solar flares depends on obtaining reliable determinations of the energy input to flare plasma. X-ray observations of the thermal bremsstrahlung from hot flare plasma provide temperatures and emission measures which, along with estimates of the plasma volume, allow the energy content of this hot plasma to be computed. However, if thermal energy losses are significant or if significant energy goes directly into cooler plasma, this is only a lower limit on the total energy injected into thermal plasma during the flare. We use SOHO UVCS observations of O VI flare emission scattered by coronal O VI ions to deduce the flare emission at transition region temperatures between 100,000 K and 1 MK for the 2002 July 23 and other flares. We find that the radiated energy at these temperatures significantly increases the deduced energy input to the thermal plasma, but by an amount that is less than the uncertainty in the computed energies. Comparisons of computed thermal and nonthermal electron energies deduced from RHESSI, GOES, and UVCS are shown.
DE: 7519 Flares
DE: 7549 Ultraviolet emissions
DE: 7554 X rays, gamma rays, and neutrinos
SC: Solar Physics Division - AAS [SP]
MN: 2005 Joint Assembly