• DOI:10.1111/j.1365-2966.2010.16939.x
• Corpus ID: 55855450

The early dynamical evolution of cool, clumpy star clusters

@article{Allison2010TheED,
  title={The early dynamical evolution of cool, clumpy star clusters},
  author={Richard J. Allison and S. P. Goodwin and Richard J. Parker and Simon Portegies Zwart and Richard de Grijs},
  journal={Monthly Notices of the Royal Astronomical Society},
  year={2010},
  volume={407},
  pages={1098-1107}
}

• R. Allison, S. Goodwin, +2 authors R. Grijs
• Published 29 April 2010
• Physics
• Monthly Notices of the Royal Astronomical Society

Observations and theory both suggest that star clusters form sub-virial (cool) with
highly sub-structured distributions. We perform a large ensemble of N-body simulations
of moderate-sized (N = 1000) cool, fractal clusters to investigate their early
dynamical evolution. We find that cool, clumpy clusters dynamically mass segregate
on a short timescale, that Trapezium-like massive higher-order multiples are commonly
formed, and that massive stars are often ejected from clusters with velocities
> 10 km s−1
(c.f. the average escape velocity of 2.5 km s−1
). The properties of clusters
also change rapidly on very short timescales. Young clusters may also undergo
core collapse events, in which a dense core containing massive stars is hardened due
to energy losses to a halo of lower-mass stars. Such events can blow young clusters
apart with no need for gas expulsion. The warmer and less substructured a cluster is
initially, the less extreme its evolution.