Abstract

Using six-dimensional phase-space information from the Fourth Data release of the RAdial Velocity Experiment (RAVE) over the range of Galactic longitude 240 degrees l 360 degrees and V-LSR -239 km s(-1), we computed orbits for 329 RAVE stars that were originally selected as chemically and kinematically related to omega Centauri. The orbits were integrated in a Milky-Way-like axisymmetric Galactic potential, ignoring the effects of the dynamical evolution of omega Centauri due to the tidal effects of the Galaxy disk on the cluster along time. We also ignored secular changes in the Milky Way potential over time. In a Monte Carlo scheme, and under the assumption that the stars may have been ejected with velocities greater than the escape velocity (V-rel > V-esc,V-0) from the cluster, we identified 15 stars as having close encounters with omega Centauri: (i) 8 stars with relative velocities V-rel 200 km s(-1) may have been ejected similar to 200 Myr ago from omega Centauri; (ii) another group of 7 stars were identified with high relative velocity V-rel > 200 km s(-1) during close encounters, and it seems unlikely that they were ejected from omega Centauri. We also confirm the link between J131340.4-484714 as a potential member of omega Centauri, and probably ejected similar to 2.0 Myr ago, with a relative velocity V-rel similar to 80 km s(-1).