Stellar Outflows Driven by Magnetized Wide‐Angle Winds

We present two-dimensional, cylindrically symmetric simulations ofhydrodynamic and magnetohydrodynamic (MHD) wide-angle winds interacting with acollapsing environment. These simulations have direct relevance to youngstellar objects (YSOs). The results may also be of use in the study ofcollimated outflows from proto-planetary and planetary nebulae. We study arange of wind configurations consistent with asymptotic MHD wind collimation.The degree of collimation is parameterized by the ratio of the wind density atthe pole to that of the equator. We find that a toroidal magnetic field canhave a significant influence on the resulting outflow, giving rise to a verydense, jet-like flow in the post-shock region. The properties of the flow inthis region are similar to the asymptotic state of a collimated MHD wind. Weconclude that wide-angle MHD winds are quite likely capable of drivingmolecular outflows. Due to difficulty in treating MHD winds ab-initio insimulations we choose magnetic field strengths in the wind consistent slowmagnetic rotators. While MHD launched winds will be in the fast rotator regimewe discuss how our results, which rely on toroidal pinch effects, will hold forstronger field strengths