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Title

Core radius evolution of star clusters

Author(s)

Wilkinson, Mark I.;  Hurley, Jarrod R.;  Mackey, A. Dougal;  Gilmore, Gerry F.;  Tout, Christopher A.

Abstract

We use N -body simulations of star clusters to investigate the possible dynamical origins of the observed spread in core radius among intermediate-age and old star clusters in the Large Magellanic Cloud (LMC). Two effects are considered, a time-varying external tidal field and variations in primordial hard binary fraction. Simulations of clusters orbiting a point-mass galaxy show similar core radius evolution for clusters on both circular and elliptical orbits and we therefore conclude that the tidal field of the LMC has not yet significantly influenced the evolution of the intermediate-age clusters. The presence of large numbers of hard primordial binaries in a cluster leads to core radius expansion; however, the magnitude of the effect is insufficient to explain the observations. Furthermore, the range of binary fractions required to produce significant core radius growth is inconsistent with the observational evidence that all the LMC clusters have similar stellar luminosity functions.

Publication type

Journal article

Source

Monthly Notices of the Royal Astronomical Society, Vol. 343, no. 3 (August 2003), p. 1025-1037

Publication year

2003

Keyword(s)

Dynamical evolution;  Galaxies;  Globular clusters;  Initial mass function;  Large Magellanic Cloud;  LMC;  N-body simulations;  Primordial binaries;  Star clusters;  Tidal tails

Publisher

Blackwell

ISSN

0035-8711

Publisher URL

http://dx.doi.org/10.1046/j.1365-8711.2003.06749.x

Copyright

Copyright © 2003 the authors. Journal compilation copyright © 2003 Royal Astronomical Society. The accepted manuscript of the paper is reproduced here in accordance with the copyright policy of the publisher. The definitive publication is available at www.interscience.wiley.com.

Full text

Peer reviewed