HR: 1330h
AN: SH23A-02    [Abstracts]
TI: Characteristics of the Solar Wind Termination Shock From Voyager 1 Observations
AU: * Cummings, A C
EM: ace@srl.caltech.edu
AF: California Institute of Technology, Mail Code 220-47, Pasadena, CA 91125 United States
AU: Stone, E C
EM: ecs@srl.caltech.edu
AF: California Institute of Technology, Mail Code 220-47, Pasadena, CA 91125 United States
AB: For much of the time since mid-2002, the Voyager 1 spacecraft has apparently been on interplanetary magnetic field lines connected to a source of particles at the solar wind termination shock. The source point is back along the field lines towards the Sun, as suggested by the streaming anisotropies. The energy spectra often resemble the energy spectra expected for anomalous cosmic rays (ACRs) at the shock, with one important difference. Although the spectra often have a power-law dependence at low energies and a roll off to a much steeper power-law spectrum at higher energies, as expected for the ACR spectrum at the shock, the energy of this roll off is much lower than observed in the ACR spectrum at the same time. Hence, the ACRs must be originating from a different part of the shock. The observed energy spectrum sometimes appears modulated at low energies, as if there is turbulence along the field line between Voyager 1 and the shock. At other times, it appears that there is little scattering in the intervening space. We will examine the observed energy spectra to infer key characteristics of the shock region sampled by Voyager 1, such as the shock strength, the perpendicular mean free path, and the rigidity dependence of the mean free path. This work was supported by NASA under contract NAS7-03001.
DE: 2104 Cosmic rays
DE: 2114 Energetic particles, heliospheric (7514)
DE: 2124 Heliopause and solar wind termination
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2005 Joint Assembly