Distance to the Solar Wind Termination Shock and the Source Flux of Anomalous Cosmic Rays During 1986-1988
Creators
Abstract
We use observations of the intensity of anomalous cosmic ray helium and oxygen in the outer heliosphere near the last solar minimum period, in conjunction with solar observations of the tilt of the neutral current sheet, to estimate that the solar wind termination shock was at 67 ± 5 AU during the time period 1986.7-1988.5. We find the source flux of anomalous cosmic rays at the shock to be 1.7 ± 0.3 (m² s sr MeV/nucleon)^(−1) for 7.1-17.1 MeV/nucleon anomalous cosmic ray oxygen and 4.3 ± 0.8 (m² s sr MeV/nucleon)^(−1) for 31-57 MeV/nucleon anomalous cosmic ray helium. We also estimate a source flux of anomalous cosmic ray hydrogen of 2.3 ± 0.6 (m² s sr MeV)^(−1) at 134 MeV. The resulting energy density of anomalous cosmic rays at the solar wind termination shock is ∼0.03 eV/cm³, approximately 2% of the energy density of the solar wind at 67 AU.
Additional Information
Copyright 1994 by the American Geophysical Union. (Received October 22, 1993; revised January 21, 1994; accepted February 21, 1994.) We are grateful to J. T. Hoeksema for providing the neutral sheet tilt data in machine readable form. This work was supported in part by NASA under contract NAS7-918 and grant NAGW-1919. The Editor thanks L. A. Fisk and M. A. Forman for their assistance in evaluating this paper.Attached Files
Published - 1993-37.pdf
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1993-37.pdf
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- Eprint ID
- 45842
- Resolver ID
- CaltechAUTHORS:20140520-100248179
Funding
- NASA
- NAS7-918
- NASA
- NAGW-1919
Dates
- Created
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2014-05-28Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field
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- Space Radiation Laboratory
- Other Numbering System Name
- Space Radiation Laboratory
- Other Numbering System Identifier
- 1993-37