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Appendix A: Orbits in a non-axisymmetric Galactic model
We also ran the simulations in a non-axisymmetric galactic potential, in order to verify the bar effect in our results. The Galactic model that we considered is the analytical potential presented in Sect. 4, and the non-axisymmetric Galactic potential including a prolate bar given by Pichardo et al. (2004) to the galactic bar, with a total mass of ~1.6 × 1010M⊙ and angular velocity of ωB = 55 ± 5 km s-1 kpc-1 (e.g., Pichardo et al. 2012). Using the same considerations as in Sect. 4 to model the orbits of the RAVE stars and ω Centauri, 105 pairs of orbits were integrated to 0.2 Gyr in the past. Figures A.1 and A.2 show the results to the stars listed in Table 1; the probabilities of close encounters are similar in both Galactic potential, and the bar effects for integration time <0.2 Gyr, do not affect the results presented in this work.
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Fig. A.1
Relative velocity (Vrel) distribution for 105 pairs of orbits integrated backward in time over 0.2 Gyr in an axisymmetric (pink histograms) and non-axisymmetric potential (black histograms). |
| Open with DEXTER | |
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Fig. A.2
davg distribution. The pink and red histograms are the same as in Fig. A.1. |
| Open with DEXTER | |
ω Centauri candidates selected from RAVE catalog, their abundance ratios, and space velocities.
© ESO, 2015