Two-dimensional models of stellar wind bubbles. III. Self-confining flows in media with strong density gradients.
Hydrodynamical models of stellar wind bubbles evolving in a medium with strong density gradients are presented. Wind parameters are representative of T Tauri stars. The nonuniformity of the medium is caused by the presence of compact circumstellar discs which are simulated by plane-parallel stratified slabs. The bubbles beak out of the discs and evolve into secondary bubbles and/or into hollow cylinders. In the latter case self-confining flows are established due to combined effects of cooling and momentum conservation and a significant degree of collimation of originally isotropic winds can be achieved. During breakout the outer shock front of the bubble may separate from the shell, propagate to large distances from the wind source and drive a bipolar molecular outflow.
Astronomy and Astrophysics
- Pub Date:
- June 1985