Voyager observations of energetic particles near the solar wind termination shock
Voyager 1 is observing the energy spectra of anomalous cosmic ray H, He, and O in the heliosheath. The relative abundance of H/He is 20 at 1-1.5 MeV/nuc, indicating that H pickup ions are more efficiently accelerated than was modeled from observations at higher energies. Voyager 2 began observing upstream energetic ions from the shock in late 2004 at ∼75 AU, about 10 AU closer to the Sun than observed by Voyager 1. Voyager 2 will be at 84.7 AU at the end of 2007 and may have crossed the termination shock.
Additional InformationCopyright Universidad Nacional Autónoma de México We thank the Voyager Low Energy Charge Particle team for the use of their data in Figure 3. This work was supported under contract NAS7-03001.
Published - 2008-19.pdf