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D/H and O-18/O-16 ratio in the hydronium ion and in neutral water from in situ ion measurements in comet Halley

Altwegg, K.; Balsiger, H.; Geiss, J.

The D/H ratio and the O-18/O-16 ratio in hydronium ions in the gas coma of comet Halley have been determined from ion data obtained by the high intensity sensor (HIS) of the ion spectometer (IMS) on board the spacecraft Giotto in 1986. The HIS instrument measured the reliable data for the water group ions over a large distance range from the nucle…

Structure of mass-loading shocks. 2. Comparison of theory and observation at comet Halley

Coates, A. J.; Neubauer, F. M.; Reme, H. +2 more

The multifluid diffusive model of G. P. Zank et al. (1994), which describes the interaction of the solar wind with a cometary plasma in the outer coma, has been used to model the structure of the Halley bow shock. The theoretical results are compared to in situ observations made by Giotto. We compare the solar wind and cometary ion number densitie…

The induced magnetosphere of comet Halley 3. The plasma kinematics

Neubauer, F. M.; Israelevich, P. L.; Ershkovich, A. I.

The plasma velocity in the magnetosphere of comet Halley is calculated by using the displacement of magnetic field lines during the Giotto flyby. The obtained profile is in good agreement with that found from the momentum balance condition. The radial component of plasma velocity measured in situ (Schwenn et al., 1987) correlates well with the spa…

Magnetic effect due to hypervelocity dust particle impact on the Giotto spacecraft

Neubauer, F. M.; Israelevich, P. L.; Ershkovich, A. I. +1 more

Magnetic field disturbance accompanying dust particle impacts is explained by means of the creation of a secondary cloud around the Giotto spacecraft. The enhancement of the magnetic field is seen as a result of the deceleration of electrons in the cometary plasma flow due to collisions with neutral atoms of the cloud surrounding the spacecraft. A…