Studies of dynamical properties of globular clusters. III. Anisotropyin omega Centauri.
Abstract
A KingMichie dynamical model has been built, based on an assumed form of the phasespace distribution function f(E,J) which induces a radial anisotropic velocity dispersion. This model consists of ten different subpopulations representing heavy remnants, white dwarfs and main sequence stars. From fitting to the surface brightness profile already published in the literature and to the mean radial velocities obtained with CORAVEL for 318 individual stars in ω Centauri, it appears that only models with strong anisotropy of the velocity dispersion (r_{a} = 2  3 r_{c}) agree with the observations. This result is related to the large halfmass relaxation time, which amounts to 20  30×10^{9}yr, the central relaxation time being of the order of 10^{9}yr. The mean value of the mass function exponent x is 1.34. The fraction of the total mass in the form of remnants heavier than the white dwarfs equals 0 to 9% of the total mass of the cluster, being inversely proportional to the fraction of white dwarfs. The total mass M_{tot} = 3.9×10^{6}M_sun; gives a masstolight ratio M/L_{V} = 2.9.
 Publication:

Astronomy and Astrophysics
 Pub Date:
 October 1987
 Bibcode:
 1987A&A...184..144M
 Keywords:

 Anisotropic Media;
 Astrodynamics;
 Centaurus Constellation;
 Galactic Rotation;
 Globular Clusters;
 Computational Astrophysics;
 Distribution Functions;
 Astrophysics