EDP Sciences
Free access
Issue
A&A
Volume 500, Number 2, June III 2009
Page(s) 901 - 908
Section The Sun
DOI http://dx.doi.org/10.1051/0004-6361/200811364
Published online 29 April 2009
A&A 500, 901-908 (2009)
DOI: 10.1051/0004-6361/200811364

Relationship between non-thermal electron energy spectra and GOES classes

R. Falewicz1, P. Rudawy1, and M. Siarkowski2

1  Astronomical Institute, University of Wrocław, 51-622 Wrocław, ul. Kopernika 11, Poland
    e-mail: [falewicz;rudawy]@astro.uni.wroc.pl
2  Space Research Centre, Polish Academy of Sciences, 51-622 Wrocław, ul. Kopernika 11, Poland
    e-mail: ms@cbk.pan.wroc.pl

Received 17 November 2008 / Accepted 31 March 2009

Abstract
Aims. We investigate influence of variations in the energy spectrum of non-thermal electrons on the resulting GOES classes of solar flares.
Methods. Twelve observed flares with various soft-to-hard X-ray emission ratios were modeled using different non-thermal electron energy distributions. Initial values of the flare physical parameters including geometrical properties were estimated using observations.
Results. We found that, for a fixed total energy of non-thermal electrons in a flare, the resulting GOES class of the flare can change significantly by varying the spectral index and low energy cut-off of the non-thermal electron distribution. Thus, the GOES class of a flare depends not only on the total non-thermal electrons energy but also on the electron beam parameters. For example, we were able to convert a M2.7 class solar flare into a merely C1.4 class one and a B8.1 class event into a C2.6 class flare. The results of our work also suggest that the level of correlation between the cumulative time integral of HXR and SXR fluxes can depend on the considered HXR energy range.


Key words: Sun: chromosphere -- Sun: corona -- Sun: flares -- Sun: magnetic fields -- Sun: X-rays, gamma rays



© ESO 2009

What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access.

An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.

  • If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
  • You can define your own OpenURL resolver with your EDPS Account.
    In this case your choice will be given priority over that of your library.
  • You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.