Physical processes in the vicinity of the cometopause interpreted on the basis of plasma, magnetic field, and plasma wave data measured on board the Vega 2 spacecraft

Abstract

This paper presents the first step toward a comprehensive interpretation of the plasma, electric, and magnetic field measurements performed by four different instruments near the cometopause of Halley's comet. No flow parameter displays any drastic variation at this boundary which separates two environments with different chemical composition. A fire hose instability is possibly developing near the cometopause where the number of cometary ions significantly increases. The waves at the lower hybrid frequency and in the whistler range have similar amplitudes.