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Research team:
P.I. Prof. dr. Edward van den Heuvel
Co.I. Prof. dr. Peter Sloot, dr. Simon Portegies Zwart,
Supported by NWO Computational Science (#635.000.001)dr. Michael Sipior,
Alessia Gualandris
Ojective: We are in the process of realizing a N-body lab with the aim to study the evolution of dense stellar systems. The UvA N-body lab (MoDeStA for Modeling Dense Star Clusters in Amsterdam) contains special purpose GRAPE hardware, which is dedicated to gravitational force calculations, attached to the Yellow node of the UvA Beowulf computer, which is a cluster of general-purpose computers. In this environment we are developing highly efficient software libraries containing N-body kernels, such as the direct method, hierarchical methods, and others. The unique combination of GRAPE hardware with a cluster results in speed up of both the direct force calculations, by running them on GRAPE, and a speed up the remaining calculations by parallelizing them over the Beowulf. This allows to remove e.g. known bottle-necks in hierarchical methods executing on GRAPE hardware attached to a single host computer. Together with existing intelligent batch processing tools and interactive visualization technology the N-body lab is now a very powerful generic infrastructure. We are now in the process of studying the dynamical evolution of dense stellar systems (globular clusters and galactic bulges) and the formation and evolution of intermediate mass black holes in dense star clusters. The latter research resulted in a publication in Nature, last April. Currently we are in the process of studying the effect of the presence of binary stars on the evolution toward and through core collapse in globular clusters. During core collapse, which is a consequence of the long term evolution of a system in near equilibrium and with a negative heat capacity, very unusual close interactions between stars occur, the outcomes of which are still unknown. Below we itemize our progress in the structure predetermined by NWO-EW
Activities organized during the course of this project:
Workshops:
Summer school:
- MODEST-5c (July 2005)
Software development
- Distributed parallel N-body code NbodySH1p
- GRAPE-6 supported N-body testsuit
- McScatter
- Binary visualization package Roche
Miscellaneous
Status: Running (Expected finish in Summer 2006)