HR: 08:00h
AN: SH41B-01 INVITED     [Abstracts]
TI: Voyager in the Vicinity of the Termination Shock: Observations and Questions
AU: * Stone, E C
EM: ecs@srl.caltech.edu
AF: California Institute of Technology, 1200 E. California Blvd. Mail Stop 220 47, Pasadena, CA 91125 United States
AB: For most of the last two and a half years, Voyager 1 has observed enhanced intensities of energetic ions streaming along the magnetic field, suggesting that the source is a durable rather than transient feature of this region of the heliosphere beyond 85 AU. If Voyager 1 is in the solar wind, the beaming requires a non-spherical termination shock, but is the asymmetry of the shock large enough and in the right location? The small average radial anisotropy requires a large radial gradient, but is that consistent with lack of energy dependent modulation at low energies? If Voyager 1 is in the heliosheath, the outward beaming direction and small radial anisotropy are consistent, but are strong, persistent beams expected in the turbulent heliosheath, and what is the mechanism for avoiding the expected compression of the magnetic field? Whether or not Voyager 1 crossed the shock, there appear to be two distinct sources of accelerated interstellar pickup ions. Why does the nearby source region connected directly to Voyager 1 accelerate He ions to less that ~10 MeV/nucleon, while the more distant source region accelerates He ions to much higher energies? These and other aspects of the observations are revealing the unexpected nature of the termination shock and particle acceleration.
DE: 2104 Cosmic rays
DE: 2114 Energetic particles, heliospheric (7514)
DE: 2124 Heliopause and solar wind termination
DE: 2134 Interplanetary magnetic fields
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2004 AGU Fall Meeting