Electron Bremsstrahlung Hard X-Ray Spectra, Electron Distributions, and Energetics in the 2002 July 23 Solar Flare

Details Electron Bremsstrahlung Hard X-Ray Spectra, Electron Distributions, and Energetics in the 2002 July 23 Solar Flare Electron Bremsstrahlung Hard X-Ray Spectra, Electron Distributions, and Energetics in the 2002 July 23 Solar Flare

Oct 2003

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2003apj...595l..97h&link_type=abstract

The Astrophysical Journal, Volume 595, Issue 2, pp. L97-L101.

Astronomy and Astrophysics

Astronomy

134

Sun: Flares, Sun: X-Rays, Gamma Rays

Scientific paper

We present and analyze the first high-resolution hard X-ray spectra from a solar flare observed in both X-ray/γ-ray continuum and γ-ray lines. Spatially integrated photon flux spectra obtained by the Ramaty High Energy Solar Spectroscopic Imager (RHESSI) are well fitted between 10 and 300 keV by the combination of an isothermal component and a double power law. The flare plasma temperature peaks at 40 MK around the time of peak hard X-ray emission and remains above 20 MK 37 minutes later. We derive the nonthermal mean electron flux distribution in one time interval by directly fitting the RHESSI X-ray spectrum with the thin-target bremsstrahlung from a double-power-law electron distribution with a low-energy cutoff. We find that relativistic effects significantly impact the bremsstrahlung spectrum above 100 keV and, therefore, the deduced mean electron flux distribution. We derive the evolution of the injected electron flux distribution on the assumption that the emission is thick-target bremsstrahlung. The injected nonthermal electrons are well described throughout the flare by a double-power-law distribution with a low-energy cutoff that is typically between 20 and 40 keV. We find that the power in nonthermal electrons peaks before the impulsive rise of the hard X-ray and γ-ray emissions. We compare the energy contained in the nonthermal electrons with the energy content of the thermal flare plasma observed by RHESSI and GOES. The minimum total energy deposited into the flare plasma by nonthermal electrons, 2.6×1031 ergs, is on the order of the energy in the thermal plasma.

Affiliated with

Also associated with

No associations

Rating

Electron Bremsstrahlung Hard X-Ray Spectra, Electron Distributions, and Energetics in the 2002 July 23 Solar Flare does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Electron Bremsstrahlung Hard X-Ray Spectra, Electron Distributions, and Energetics in the 2002 July 23 Solar Flare, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electron Bremsstrahlung Hard X-Ray Spectra, Electron Distributions, and Energetics in the 2002 July 23 Solar Flare will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-912955