Life and Death of Young Dense Star Clusters near the Galactic Center

Simon F. Portegies Zwart1 Stephen L. W. McMillan2 Holger Baumgardt3


(1) Astronomical Institute `Anton Pannekoek', University of Amsterdam, Kruislaan 403, the Netherlands and Institute for Computer Science, University of Amsterdam, Kruislaan 403
(2) Department of Physics, Drexel University, Philadelphia, PA 19104, USA
(3) Institute of Advanced Physical and Chemical Research RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-019, Japan

EPrint Server: astro-ph/0403147


Abstract:

We discuss the structural change and degree of mass segregation of young dense star clusters within about 100 pc of the Galactic center. In our calculations, which are performed with GRAPE-6, the equations of motion of all stars and binaries are calculated accurately but the external potential of the Galaxy is solved (semi)analytically. The simulations are preformed to model the Arches star cluster. We find that star clusters with are less strongly perturbed by the tidal field and dynamical friction are much stronger affected by mass segregation; resulting in a significant pile-up of massive stars in the cluster center. At an age of about 3.5 Myr more than 90 per cent of the stars more massive than 10 \msun are concentrated within the half-mass radius of the surviving cluster. Star clusters which are strongly perturbed by the tidal field of the parent Galaxy are much less affected by mass segregation.


Preprints available from the authors at spz@science.uva.nl , or the raw TeX (no figures) if you click here.

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