Bonn 2010 – wissenschaftliches Programm

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EP: Fachverband Extraterrestrische Physik

EP 7: Fundamental Physics

EP 7.1: Vortrag

Dienstag, 16. März 2010, 15:00–15:15, AKM

A new particle invariant suggested by frozen-in magnetic field lines at the solar wind termination shock — •Mark Siewert and Hans-Jörg Fahr — Argelander-Institut für Astronomie, Uni Bonn

Among other concepts, Magnetohydrodynamics introduces the frozen-in field condition, which causes magnetic field lines to be convected along with the plasma flow velocity U^→. However, in astrophysical boundary layers (i.e. shock waves), deceleration is discontinous, and therefore, it is highly nontrivial to describe how the gyrating ions will react to this. In the past, we have studied this problem under the assumption that the classical electromagnetic invariant, the magnetic moment, is still conserved in the transition layer of the shock, which, however, results in too weak temperature gains when compared to the solar wind termination shock data taken by the Voyagers. We now present a new approach, based on the concept that decelerated frozen-in field lines lead to a local overshooting configuration, which modifies the classical gyrational motion, ultimately leading to a better agreement with the solar wind termination shock data.