Freiburg 2008 – scientific programme
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EP: Fachverband Extraterrestrische Physik
EP 4: The Sun and Heliosphere - Poster Session
EP 4.15: Poster
Monday, March 3, 2008, 17:30–19:00, Vorraum KGI-Aula
Are "Anomalous" Cosmic Rays the Main Contribution to the Low-Energy "Galactic" Cosmic Ray Spectrum? — •Klaus Scherer1, Horst Fichtner1, Stefan Ferreira2, Ingo Büsching2, and Marius Potgieter2 — 1Institut für Theoretische Physik, Lehrstuhl IV: Weltraum- und Astrophysik, Ruhr-Universität Bochum, D-44780, Bochum, Germany — 2Unit for Space Physics, North-West University, 2520 Potchefstroom, South Africa
While the high-energy part of the galactic cosmic ray spectrum is well observed, its nature at energies below about 1 GeV/nucleon is still not known well. Recent in-situ measurements made with the Voyager 1 spacecraft in the heliosheath between the solar wind termination shock and the heliopause have not only added further constraints to the local interstellar spectrum of galactic cosmic rays at low energies, but also suggest how the proton part is formed in the Galaxy. It appears that the acceleration of heliospheric anomalous cosmic rays does not only take place at the solar wind termination shock but to an even larger extent within the heliosheath leading to a significantly higher source strength than expected. Combining this finding with recent model results for astrospheres immersed in different interstellar environments shows that the astrospheric anomalous cosmic ray fluxes of solar-type stars can be a hundred times higher than thought earlier and, consequently, their total contribution to the lower end of the interstellar spectrum can be significant.