Astronomy and Astrophysics – Astrophysics
Scientific paper
2008-08-18
Astrophys.J.689:1005-1019,2008
Astronomy and Astrophysics
Astrophysics
AASTeX v5.2, 37 pages with 2 figures, accepted for publication in The Astrophysical Journal
Scientific paper
10.1086/592684
Spherical models of collisionless but quasi-relaxed stellar systems have long been studied as a natural framework for the description of globular clusters. Here we consider the construction of self-consistent models under the same physical conditions, but including explicitly the ingredients that lead to departures from spherical symmetry. In particular, we focus on the effects of the tidal field associated with the hosting galaxy. We then take a stellar system on a circular orbit inside a galaxy represented as a "frozen" external field. The equilibrium distribution function is obtained from the one describing the spherical case by replacing the energy integral with the relevant Jacobi integral in the presence of the external tidal field. Then the construction of the model requires the investigation of a singular perturbation problem for an elliptic partial differential equation with a free boundary, for which we provide a method of solution to any desired order, with explicit solutions to two orders. We outline the relevant parameter space, thus opening the way to a systematic study of the properties of a two-parameter family of physically justified non-spherical models of quasi-relaxed stellar systems. The general method developed here can also be used to construct models for which the non-spherical shape is due to internal rotation. Eventually, the models will be a useful tool to investigate whether the shapes of globular clusters are primarily determined by internal rotation, by external tides, or by pressure anisotropy.
Bertin Giuseppe
Varri Anna L.
No associations
LandOfFree
The construction of non-spherical models of quasi-relaxed stellar systems 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 The construction of non-spherical models of quasi-relaxed stellar systems, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The construction of non-spherical models of quasi-relaxed stellar systems will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-698666