Ballistic stellar jets from sources with a time-dependent ejection direction

Abstract

We present models of astrophysical jets ejected from sources with atime-dependent ejection direction. The perturbations in the ejectiondirection are amplified as a result of a `garden-hose' effect, resultingin a `twisted filament' morphology for the jet. Because of this, atlarge distances from the source the motion of the material is mostlyperpendicular to the direction of the jet filament, leading to a`sideways interaction' between the jet and the surrounding environment.We derive simple models for the kinematics of the jet and for thejet-environment interaction. From these models, we compute emission-lineintensity maps that can be directly compared with observations ofstellar jets.