Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2009-09-11
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
Comments: 8 pages, 3 figures, accepted by MNRAS
Scientific paper
General criteria to check the positivity of the distribution function (phase-space consistency) of stellar systems of assigned density and anisotropy profile are useful starting points in Jeans-based modeling. Here we substantially extend previous results, and we present the inversion formula and the analytical necessary and sufficient conditions for phase-space consistency of the family of multi-component Cuddeford spherical systems: the distribution function of each density component of these systems is defined as the sum of an arbitrary number of Cuddeford distribution functions with arbitrary values of the anisotropy radius, but identical angular momentum exponent. The radial trend of anisotropy that can be realized by these models is therefore very general. As a surprising by-product of our study, we found that the ``central cusp-anisotropy theorem'' (a necessary condition for consistency relating the values of the central density slope and of the anisotropy parameter) holds not only at the center, but at all radii in consistent multi-component generalized Cuddeford systems. This last result suggests that the so--called mass--anisotropy degeneracy could be less severe than what is sometimes feared.
Ciotti Luca
Morganti Lucia
No associations
LandOfFree
Consistency criteria for generalized Cuddeford 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 Consistency criteria for generalized Cuddeford systems, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Consistency criteria for generalized Cuddeford systems will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-428228