When is Uniform Rotation an Energy Minimum?

Astronomy and Astrophysics – Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

8 pages, AAS Tex Macros, Submitted to ApJ (Letters)

Scientific paper

A simple variational calculation is presented showing that a uniformly rotating barotropic fluid in an external potential attains a true energy minimum if and only if the rotation profile is everywhere subsonic. If regions of supersonic rotation are present, fluid variations exist that could take the sytem to states of lower energy. In any given system, these states may or may not be dynamically accessible, but their existence is important. It means that extending the degrees of freedom available to the fluid (say by weak magnetic fields) may open a path to fluid instabilities. Whether astrophysical gaseous nebula tend toward states of uniform rotation or toward more Keplerian core-disk systems appears to be largely a matter of whether the rotation profile is transonic or not. The suggestion is made that the length scale associated with coherent molecular cloud cores is related to the requirement that the cores be stable and rotate subsonically.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

When is Uniform Rotation an Energy Minimum? does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with When is Uniform Rotation an Energy Minimum?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and When is Uniform Rotation an Energy Minimum? will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-110511

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.