Astronomy and Astrophysics – Astrophysics
Scientific paper
2005-11-03
Astronomy and Astrophysics
Astrophysics
24 pages, 10 figures, accepted for publication by A&A
Scientific paper
10.1051/0004-6361:20053665
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.
Gros Michel
Kiener Juergen
Tatischeff Vincent
Weidenspointner Georg
No associations
LandOfFree
Properties of the energetic particle distributions during the October 28, 2003 solar flare from INTEGRAL/SPI observations 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 Properties of the energetic particle distributions during the October 28, 2003 solar flare from INTEGRAL/SPI observations, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Properties of the energetic particle distributions during the October 28, 2003 solar flare from INTEGRAL/SPI observations will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-482308