The Magnetic Collimation of Bipolar Out ows I: Adiabatic Simulations
نویسندگان
چکیده
The collimation of an isotropic, non-magnetic protostellar wind by an ordered magnetic eld in the ambient medium is investigated using self-consistent magnetohydrodynamic simulations in two-dimensions. The strong protostellar wind in ates a low density bubble in the ambient medium. The growth of this bubble is con ned along the direction of the ambient magnetic eld when the gas pressure in the interior drops to the level of the magnetic pressure at the surface. For typical molecular cloud conditions, collimation of the protostellar wind into a bipolar out ow occurs on timescales of 10 4 10 5 yrs. When a self-consistent model for a magnetically supported cloud is used as a more realistic initial condition, the wind blown bubble can \blowout" along diverging eld lines in the direction of the steepest density gradient. Subject headings: ISM: jets and out ows radio lines: molecular: circumstellar stars: pre-main-sequence
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