CaltechAUTHORS
Published October 2001 | Version public
Journal Article Metadata-only

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

Creators

  • 1. ROR icon Jet Propulsion Lab
  • 2. ROR icon California Institute of Technology
  • 3. ROR icon Washington University in St. Louis

Abstract

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 ^(56)Fe are reported for eleven isotopes of Ca, Fe, Co, and Ni, including the very rare isotopes ^(48)Ca and ^(64)Ni. Although the source abundances range over a factor ∼10^4, most of the ratios to ^(56)Fe 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 ^(58)Fe/^(56)Fe. The possible association of such an excess with a contribution to the cosmic-ray source from Wolf–Rayet star ejecta is discussed.

Additional Information

© 2001 Kluwer Academic Publishers. Received 29 September 2000; Accepted in final form: 15 January 2001. We are grateful to the large group of dedicated individuals that participated in the development of the CRIS instrument (listed in Stone et al., 1998). We also thank J. Klarmann for contributions to the CRIS data analysis. This research was supported by the National Aeronautics and Space Administration at the California Institute of Technology (under grant NAG5-6912), the Jet Propulsion Laboratory, the Goddard Space Flight Center, and Washington University.

Additional details

Identifiers

Eprint ID
48966
Resolver ID
CaltechAUTHORS:20140827-090214937

Related works

Describes
https://resolver.caltech.edu/CaltechAUTHORS:20200506-160349946 (URL)

Funding

NASA
NAG5-6912
JPL
Goddard Space Flight Center
Washington University

Dates

Created
2014-08-27
Created from EPrint's datestamp field
Updated
2021-11-10
Created from EPrint's last_modified field

Caltech Custom Metadata

Caltech groups
Space Radiation Laboratory , Physics Department
Other Numbering System Name
Space Radiation Laboratory
Other Numbering System Identifier
2001-12