The ellipticities of Galactic and LMC globular clusters

Abstract

The globular clusters of the LMC are found to be significantly more elliptical than Galactic globular clusters, but very similar in virtually all other respects. The ellipticity of the LMC globular clusters is shown not be correlated with the age or mass of those clusters. It is proposed that the ellipticity differences are caused by the different strengths of the tidal fields in the LMC and the Galaxy. The strong Galactic tidal field erases initial velocity anisotropies and removes angular momentum from globular clusters making them more spherical. The tidal field of the LMC is not strong enough to perform these tasks and its globular clusters remain close to their initial states.

3 pages LaTeX file with 3 figures incorporated accepted for publication in MNRAS. Also available by e-mailing spg, or by ftp from ftp://star-www.maps.susx.ac.uk/pub/papers/spg/ellip.ps.Z

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