[Previous] | [Session 22] | [Next]
V. Icke (Sterrewacht Leiden)
Planetary nebulae are rarely spherical. More often they show a pronounced bipolar shape. Balick proposed that such forms arise due to an interaction between a very fast tenuous outflow, the `last gasp' of the star, and a disk-shaped denser atmosphere left over from an earlier slow phase of mass loss. Analytical and numerical work shows that this mechanism works very well. However, many circumstellar nebulae have a `multipolar' or `point-symmetric' shape. I demonstrate that these seemingly enigmatic forms can be easily reproduced by a two-wind model in which the confining disk is warped, as is expected to occur in irradiated disks. Large-scale explosions in other non-planar disks, such as might occur in active galaxies, are expected to show similar patterns.
If you would like more information about this abstract, please follow the link to http://www.strw.LeidenUniv.nl/~icke/. This link was provided by the author. When you follow it, you will leave the Web site for this meeting; to return, you should use the Back comand on your browser.
The author(s) of this abstract have provided an email address for comments about the abstract: icke@strw.LeidenUniv.nl
[Previous] | [Session 22] | [Next]
Bulletin of the American Astronomical Society, 34, #4
© 2002. The American Astronomical Soceity.