Toward more realistic analytic models of the heliotail: Incorporating magnetic flattening via distortion flows

TL;DR

This paper introduces a mathematical method to deform magnetic field models of the heliotail, accounting for observed flattening, while maintaining physical constraints, supported by analysis of advanced simulations.

Contribution

A novel deformation technique for magnetic fields that incorporates realistic heliotail flattening into analytical models, consistent with physical laws.

Findings

Quantitative analysis of heliotail distortion from 3D hybrid simulations

Method preserves solenoidality and induction equation constraints

Provides more realistic analytical models of the heliotail

Abstract

Both physical arguments and simulations of the global heliosphere indicate that the tailward heliopause is flattened considerably in the direction perpendicular to both the incoming flow and the large-scale interstellar magnetic field. Despite this fact, all of the existing global analytical models of the outer heliosheath's magnetic field assume a circular cross section of the heliotail. To eliminate this inconsistency, we introduce a mathematical procedure by which any analytically or numerically given magnetic field can be deformed in such a way that the cross sections along the heliotail axis attain freely prescribed, spatially dependent values for their total area and aspect ratio. The distorting transformation of this method honors both the solenoidality condition and the stationary induction equation with respect to an accompanying flow field, provided that both constraints were already satisfied for the original magnetic and flow fields prior to the transformation. In order to obtain realistic values for the above parameters, we present the first quantitative analysis of the heliotail's overall distortion as seen in state-of-the-art three-dimensional hybrid MHD-kinetic simulations.