SCYON Abstract

Received on March 13 2004

Core Formation by a Population of Massive Remnants

AuthorsDavid Merritt1, Slawomir Piatek2, Simon Portegies Zwart3, Marc Hemsendorf4
Affiliation1 Rochester Institute of Technology
2 New Jersey Institute of Technology
3 University of Amsterdam
4 Rutgers University
Submitted toAstrophysical Journal


Core radii of globular clusters in the Large and Small Magellanic Clouds show an increasing trend with age. We propose that this trend is a dynamical effect resulting from the accumulation of massive stars and stellar-mass black holes at the cluster centers. The black holes are remnants of stars with initial masses exceeding 20-25 solar masses; as their orbits decay by dynamical friction, they heat the stellar background and create a core. Using analytical estimates and N-body experiments, we show that the sizes of the cores so produced and their growth rates are consistent with what is observed. We propose that this mechanism is responsible for the formation of cores in all globular clusters and possibly in other systems as well.