Bipolar jets from a star-torus system: effect of torus' gravity

We examine the hydrodybnamical wind-type jet in the funnel formed along a rotational axis of accretion tori surrounding a protostar, taking into account the gravitational field produced by the torus gas. The behavior of a jet flow is drastically changed due to the effect of gravity of the torus gas. Multiple critical points appear in some cases. For large values of the specific energy of the flow, the jet flow passes through the inner critical point, whereas it passes through the outer one for small values. A slight change in the flow energy leads to a drastic transition of the location of the critical point where the flow passes through. (author)