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Pick-up ions at Comet P/Halley's bow shock - Observations with the IIS spectrometer on GiottoGaseous material expanding from the nucleus of Comet Halley into space forms the neutral coma around the comet. Ionization in the solar UV radiation removes particles from the coma and injects them into the solar wind plasma. These freshly created ions are accelerated by the interplanetary electric field on cycloidal trajectories with gyrocenters moving with the speed of the magnetic field lines. In the solar wind frame of reference these particles move along the magnetic field lines with a fixed pitch angle. Pitch-angle scattering and energy diffusion reduce quickly the initial energy anisotropy which is associated with the narrow pick-up structures. First observations of heavy cometary pick-up ions (water group ions) at the bow shock are presented. The evolution of the distribution function in the vicinity of the shock and radial density profiles are discussed.
Document ID
19880036207
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Wilken, B.
(Max-Planck-Institut fuer Aeronomie Katlenburg-Lindau, Federal Republic of Germany, United States)
Johnstone, A.
(Max-Planck-Inst. fuer Aeronomie Katlenburg-Lindau, Germany)
Coates, A.
(London, University College, Dorking, United Kingdom)
Amata, E.
(CNR Istituto di Fisica dello Spazio Interplanetario, Frascati, Italy)
Borg, H.
(Max-Planck-Inst. fuer Aeronomie Katlenburg-Lindau, Germany)
Date Acquired
August 13, 2013
Publication Date
November 1, 1987
Publication Information
Publication: Astronomy and Astrophysics
Volume: 187
Issue: 1-2
ISSN: 0004-6361
Subject Category
Astrophysics
Accession Number
88A23434
Funding Number(s)
CONTRACT_GRANT: BMFT-01-OF-112-4
CONTRACT_GRANT: NASW-3574
CONTRACT_GRANT: NASA ORDER W-15164
Distribution Limits
Public
Copyright
Other

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