Simulations of stellar winds and planetary bodies: Ionosphere-rich obstacles in a super-Alfvénic flow
Résumé
We classify the interactions of planetary obstacles with an upstream stellar wind. The investigation of each type of interaction is made using a three dimensional simulation code based on the hybrid modeling of the interplanetary plasma (the AIKEF code). The aim is to fill up the parameter space of magnetospheric interactions. In this work, we focus on highly resistive obstacles, non-magnetized but possessing an ionosphere. We examine different ionospheric types by focusing on one parameter: the ionospheric production. Two types of ionospheric ions are used: H+ and O+, to show the influence of ionospheric ion mass on the interaction region configuration. The interaction types are classified using an equivalent conductivity of the ionosphere. The resulting induced magnetospheric interactions are described using the currents flowing throughout the interaction region. The essence of the interaction region structure is summarized into three-dimensional diagrams of the current distribution. The results show three main stages of development. The first is a lunar-type interaction with raising asymmetries. The second is depicted by the presence of a growing induced magnetopause and an interaction region which asymmetry depends on the mass of the ionospheric ions. The last stage is a fully developed induced magnetosphere, or Venus-like interaction, with a symmetric magnetosphere.