The Origin of Primary Cosmic Rays: Constraints from ACE Elemental and Isotopic Composition Observations.

Autor: Wiedenbeck, M.E., Yanasak, N.E., Cummings, A.C., Davis, A.J., George, J.S., Leske, R.A., Mewaldt, R.A., Stone, E.C., Hink, P.L., Israel, M.H., Lijowski, M., Christian, E.R., von Rosenvinge, T.T.
Zdroj: Space Science Reviews; Oct2001, Vol. 99 Issue 1-4, p15-26, 12p
Abstrakt: Cosmic-ray isotope observations from NASA’s Advanced Composition Explorer (ACE) mission have been used to investigate the composition of cosmic-ray source material. Source abundances relative to 56Fe are reported for eleven isotopes of Ca, Fe, Co, and Ni, including the very rare isotopes 48Ca and 64Ni. Although the source abundances range over a factor ∼104, most of the ratios to 56Fe are consistent with solar-system values to within ∼20%. However, there are some notable differences, the most significant being an excess of ∼(70±30)% relative to the solar system for the cosmic-ray source ratio 58Fe/56Fe. The possible association of such an excess with a contribution to the cosmic-ray source from Wolf–Rayet star ejecta is discussed. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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