Astronomy and Astrophysics – Astrophysics
Scientific paper
2005-07-13
Astron.Nachr.327:925-935,2006
Astronomy and Astrophysics
Astrophysics
53 pages, 4 figures, 1 table, improved version with bending instabilities mentioned and discussed, and related references adde
Scientific paper
10.1002/asna.200510653
With regard to homeoidally striated Jacobi ellipsoids, a unified theory of systematically rotating and peculiar motions is developed, where both real and imaginary rotation are considered. The effect of positive or negative residual motion excess, is shown to be equivalent to an additional real or imaginary rotation, respectively. Then it is realized that a homeoidally striated Jacobi ellipsoid with assigned velocity distribution, always admits an adjoint configuration i.e. a classical Jacobi ellipsoid of equal mass and axes. In addition, further constraints are established on the amount of residual velocity anisotropy along the principal axes, for triaxial configurations. Special effort is devoted to investigating sequences of virial equilibrium configurations in terms of normalized parameters, including the effects of both density and velocity profile. In particular, it is shown that bifurcation points from axisymmetric to triaxial configurations occur as in classical Jacobi ellipsoids, contrary to earlier results. The reasons of the above mentioned discrepancy are also explained. An interpretation of recent results from numerical simulations on stability (Meza 2002), is provided in the light of the model. A physical interpretation of the early Hubble sequence is shortly reviewed and discussed from the standpoint of the model, according if elliptical galaxies are considered as isolated systems or embedded within dark matter haloes. In any case, a lower limit to the flattening of oblate-like configurations is established. On the other hand, it is found no lower limit to the elongation of prolate-like configurations, and observed lack of elliptical galaxies more elongated than E7 needs a different physical interpretation, such as the fully investigated bending instabilities.
No associations
LandOfFree
Homeoidally striated density profiles. II. Anisotropy and rotation 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 Homeoidally striated density profiles. II. Anisotropy and rotation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Homeoidally striated density profiles. II. Anisotropy and rotation will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-294660