Characteristics of the Termination Shock: Insights from Voyager
- California Institute of Technology, Mail Code 220-47, Pasadena, CA 91125 (United States)
We examine the energy spectra obtained from the cosmic ray instrument on the Voyager 1 spacecraft during 2002/215 through 2005/60. We find that the energy spectra of protons below {approx}20 MeV often resemble two power laws with a relatively hard index at low energies and a softer index at higher energies. The point of intersection of the two power laws is {approx}3 MeV. Beginning in 2005, the low-energy index is typically -1.5, corresponding to a shock strength (compression ratio) of 2.5. We attribute these characteristics to a restricted region of the solar wind termination shock that is sporadically connected to the Voyager 1 spacecraft by the interplanetary magnetic field. The absence of significant spectral variability in 2005 suggests that Voyager 1 entered a region with minimal spatial gradients of the lowest energy ions.
- OSTI ID:
- 20719190
- Journal Information:
- AIP Conference Proceedings, Vol. 781, Issue 1; Conference: 4. annual IGPP international astrophysics conference, Palm Springs, CA (United States), 26 Feb - 3 Mar 2005; Other Information: DOI: 10.1063/1.2032708; (c) 2005 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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