Volume 475, Number 3, December I 2007
|Page(s)||821 - 825|
|Published online||24 September 2007|
Self-consistent triaxial de Zeeuw-Carollo models
Department of Physics and Institute of Astronomy, National Tsing-Hua University, Hsin-Chu 30013, Taiwan e-mail: [pthakur;jiang]@phys.nthu.edu.tw
2 Division of Science Education, Pusan National University, Busan 609-735, Korea e-mail: [mdas;hbann]@pusan.ac.kr
3 School of Studies in Physics, Pt. Ravishankar Shukla University, Raipur 492 010, India e-mail: email@example.com
Accepted: 10 September 2007
We use the standard method of Schwarzschild to construct self-consistent solutions for the triaxial de Zeeuw & Carollo (1996) models with central density cusps. ZC96 models are triaxial generalizations of spherical γ-models of Dehnen whose densities vary as near the center and r-4 at large radii and hence, possess a central density core for and cusps for . We consider four triaxial models from ZC96, two prolate triaxials: with and 1.5, and two oblate triaxials: with and 1.5. We compute 4500 orbits in each model for time periods of . We find that a large fraction of the orbits in each model are stochastic by means of their nonzero Liapunov exponents. The stochastic orbits in each model can sustain regular shapes for ~ or longer, which suggests that they diffuse slowly through their allowed phase-space. With the exception of the oblate triaxial models with , our attempts to construct self-consistent solutions employing only the regular orbits fail for the remaining three models. However, the self-consistent solutions are found to exist for all models when the stochastic and regular orbits are treated in the same way because the mixing-time, ~, is shorter than the integration time, . Moreover, the “fully-mixed” solutions can also be constructed for all models when the stochastic orbits are fully mixed at 15 lowest energy shells. Thus, we conclude that the self-consistent solutions exist for our selected prolate and oblate triaxial models with and 1.5.
Key words: galaxies: kinematics and dynamics / galaxies: structure / methods: numerical
© ESO, 2007
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.