On charge exchange effect in the vicinity of the cometopause of Comet Halley

Journal Article · Tue Aug 01 04:00:00 EDT 1989 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/167764· OSTI ID:5337660

Ip, W H ^[1]

---

1. Max-Planck-Institut fuer Aeronomie, Katlenburg-Lindau (Germany, F.R.)

In order to explore the physical nature of the cometopause observed at Comet Halley by the Vega spacecraft and by the Giotto probe, the chemical compositional changes and variations of the thermal-energy distributions of the water-group ions are examined, adopting a two-dimensional cometary-plasma flowfield model based on three-dimensional MHD simulations of Fedder et al. (1986). The charge-exchange loss of hot cometary ions and the solar-wind protons could be used to explain the observed number-density profiles quantitatively. The resulting exponential depletion of the hot-ion populations with a scale length of about 10,000 km occurs near 60,000-80,000 km along the trajectory of Giotto, as indicated by both theoretical computations and the ion-mass-spectrometer measurements. The formation of the cometopause located at about 140,000 km is therefore not necessarily as closely related to the charge-exchange process. 27 refs.

• OSTI ID: 5337660
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 343; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics & Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BARYONS
CHARGE EXCHANGE
CHARGED PARTICLES
CHEMICAL COMPOSITION
COMETS
ELEMENTARY PARTICLES
FERMIONS
FLUID MECHANICS
HADRONS
HALLEY COMET
HYDRODYNAMICS
INTERACTIONS
ION DENSITY
IONS
MAGNETOHYDRODYNAMICS
MASS SPECTROMETERS
MATHEMATICAL MODELS
MEASURING INSTRUMENTS
MECHANICS
NUCLEONS
PROTONS
RADIATIONS
SOLAR ACTIVITY
SOLAR PARTICLES
SOLAR PROTONS
SOLAR RADIATION
SOLAR WIND
SPACE VEHICLES
SPECTROMETERS
STELLAR RADIATION
VARIATIONS
VEGA SPACE PROBES
VEHICLES