Sinuous Modes and Steady WARPS of Polytropic Disks

Details Sinuous Modes and Steady WARPS of Polytropic Disks Sinuous Modes and Steady WARPS of Polytropic Disks

Jan 1995

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1995nyasa.773...55b&link_type=abstract

Waves in Astrophysics, vol. Volume 773, p. 55-69

Astronomy and Astrophysics

Astrophysics

Polytropic Processes, Partial Differential Equations, Disk Galaxies, Gravitational Effects, Galactic Halos, Integral Equations, Halos, Astronomical Models

Scientific paper

In an asymptotic development of the equations governing the equilibria and linear stability of rapidly rotating polytropes we employed the slender aspect of these objects to reduce the three-dimensional partial differential equations to a somewhat simpler, ordinary integro-differential form. Specifically, the polytrope was characterized by an equatorial radius and a characteristic thickness, based on conditions at the center of the disk. The equations were then asymptotically solved. The earlier calculations dealt with isolated objects that were in centrifugal balance; that is, the centrifugal acceleration of the configuration was balanced largely by self-gravity with small contributions from the pressure gradient. Another interesting situation is that in which the polytrope rotates subject to externally imposed gravitational fields. The dark halos associated with disks also provide one possible explanation of the apparent warping of many galaxies. If the axis of the highly flattened disk is not aligned with that of the much less flattened halo, then the resultant torque of the halo gravity on the disk might provide a nonaxisymmetric distortion or disk warp. Motivated by these possibilities we build models of polytropic disks of small but finite thickness that are subjected to prescribed, external gravitational fields. First we estimate how a symmetrical potential distorts the structure of the disk, then we examine its sinuous modes to confirm that they are stable, hence suggesting that a warp must be externally forced. Finally, we consider steady warps of the disk plane when the axis of the disk does not coincide with that of the halo.

Affiliated with

Also associated with

No associations

Rating

Sinuous Modes and Steady WARPS of Polytropic Disks 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 Sinuous Modes and Steady WARPS of Polytropic Disks, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sinuous Modes and Steady WARPS of Polytropic Disks will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-836735