【摘 要】
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The role of stability in the general three-body problem is investigated with regard to the tidal radius of a globular cluster in a galactic potential.A stab
【出 处】
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国际天文学联合会第312次专题会议
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The role of stability in the general three-body problem is investigated with regard to the tidal radius of a globular cluster in a galactic potential.A stability analysis,outlined in Mardling(2008),is used here to predict the occurrence of unstable stellar orbits in the outermost region of a globular cluster.Stars on unstable orbits will random walk in binding energy until their eventual escape from the cluster.During the random walk stage stars will have a different distribution of velocities when compared to stars in an isolated cluster.This manifests as a flattening of the velocity dispersion profile beyond the transition radius between stable and unstable orbits.This transition radius is compared to observational data of the velocity dispersion for 15 Milky Way globular clusters with approximately known orbital parameters.We find that the stability boundary predicts flattening in the majority of clusters and that NGC 6171 may already be showing evidence of chaotic diffusion.We conclude that modifications of Newtonian dynamics are not required to explain the observations.
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