A numerical model is used to follow the two-dimensional shell of a three-dimensional radio jet. This model, in the spirit of previous work of Wiita and Siah, invokes a new computer code to relax two of their assumptions: (1) Internal pressure of the jet fluid is taken as a tensor, allowing for bulk motion of the internal relativistic gas. (2) Azimuthal symmetry is no longer assumed. Three-dimensional effects of two kinds have been modeled: bending in a "wind" resulting from motion of the host galaxy through an intergalactic medium; and stability of the jet cross-section against flattening or lobing. Results of the two-dimensional cases confirm and strengthen earlier inferences that hydrodynamics alone is incapable of accounting for observed jet collimation. Results on jet bending suggest, once again, that non-hydrodynamic effects must be invoked to explain some observations. With respect to jet cross-section, intricate oscillatory motions have been observed, some of which appear to be unstable and potentially disruptive.
- Pub Date:
- September 1987
- Physics: Astronomy and Astrophysics