Skip to Main content Skip to Navigation
Journal articles

Properties of the energetic particle distributions during the October 28, 2003 solar flare from INTEGRAL/SPI observations

Abstract : Analysis of spectra obtained with the gamma-ray spectrometer SPI onboard INTEGRAL of the GOES X17-class flare on October 28, 2003 is presented. In the energy range 600 keV - 8 MeV three prominent narrow lines at 2.223, 4.4 and 6.1 MeV, resulting from nuclear interactions of accelerated ions within the solar atmosphere could be observed. Time profiles of the three lines and the underlying continuum indicate distinct phases with several emission peaks and varying continuum-to-line ratio for several minutes before a smoother decay phase sets in. Due to the high-resolution Ge detectors of SPI and the exceptional intensity of the flare, detailed studies of the 4.4 and 6.1 MeV line shapes was possible for the first time. Comparison with calculated line shapes using a thick target interaction model and several energetic particle angular distributions indicates that the nuclear interactions were induced by downward-directed particle beams with alpha-to-proton ratios of the order of 0.1. There are also indications that the 4.4 MeV to 6.1 MeV line fluence ratio changed between the beginning and the decay phase of the flare, possibly due to a temporal evolution of the energetic particle alpha-to-proton ratio.
Complete list of metadatas

http://hal.in2p3.fr/in2p3-00025397
Contributor : Dominique Girod <>
Submitted on : Saturday, September 23, 2006 - 9:15:10 PM
Last modification on : Wednesday, September 16, 2020 - 4:17:35 PM

Links full text

Identifiers

Collections

Citation

J. Kiener, M. Gros, V. Tatischeff, G. Weidenspointner. Properties of the energetic particle distributions during the October 28, 2003 solar flare from INTEGRAL/SPI observations. Astronomy and Astrophysics - A&A, EDP Sciences, 2006, 445, pp.725-733. ⟨10.1051/0004-6361:20053665⟩. ⟨in2p3-00025397⟩

Share

Metrics

Record views

223