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

Abstract

view Abstract Citations (38) References (24) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS On Charge Exchange Effect in the Vicinity of the Cometopause of Comet Halley Ip, W. -H. Abstract 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. Publication: The Astrophysical Journal Pub Date: August 1989 DOI: 10.1086/167764 Bibcode: 1989ApJ...343..946I Keywords: Charge Exchange; Halley'S Comet; Magnetohydrodynamic Flow; Solar Wind; Chemical Composition; Energy Distribution; Flow Distribution; Giotto Mission; Vega Project; COMETS; HALLEY; CHARGE EXCHANGE; COMETOPAUSE; SPACECRAFT OBSERVATIONS; VEGA MISSIONS; GIOTTO MISSION; CHEMISTRY; THERMAL PROPERTIES; STREAMLINES; ENERGY; DISTRIBUTION; IONS; MODELS; MAGNETOHYDRODYNAMICS; DEPLETION; IMS INSTRUMENT; PLASMA; SOLAR WIND; CALCULATIONS; OXYGEN; WATER; PROTONS; THEORETICAL STUDIES; Astrophysics; Comets; COMETS; HYDROMAGNETICS; PLASMAS; SUN: SOLAR WIND full text sources ADS |