Theory
Is Fission Still Alive?
Is Fission Dead?
No, not yet. Bate presented 1 case. For more rapidly rotating systems,
large compression will occur at larger T/|W|. This means that the 2nd collapse
will occur for more rapidly rotating objects. Further, the off-center density
maxima are more pronounced at higher T/|W| increasing the possiblity of
binary star formation.
The bars are also dynamically stable after their
formation (according to Durisen et al.
1986, Bate 1998, and the quasi-linear theory) and their further evolution
is driven by dissiapative effects. Such secular processes are slow
compared to dyanmical processes and, as a result,
other physics could intervene and take over the evolution.
Possibilities are:
- As noted above, H2 dissociation may drive the further
evolution Bate (1998);
- Radiative cooling could step in to drive the long term evolution
of the bar. In this case, it is conceivable that weak density maxima
could grow leading to the formation of a close
binary system (cf. Tohline, Cazes, & Cohl 1998).
- Viscosity (through shock formation) could drive the long term
bar evolution and, in fact, there are suggestions that such effects
could cause the bar to relax into an oblate structure which is incapable
of transporting angular momentum outward to the spiral arams;
... ;
All of the above warrant further investigation.
Further Issues:
Solution:
