Implementation of an N-body Code in a HP 1000 Computer
We describe the implementation of Aarseth’s NBODY2 code on a HP 1000 computer. We use the Extended Memory Array (EMA) feature with this code in order to investigate problems that include several hundreds of bodies, but the use of EMA requires some care in order to avoid large increases in computing time. The Vector Instruction Set (VIS) feature, a group of arithmetic subroutines that operates on arrays of floating point numbers and significantly reduces the computing time, turned out to be of little value for this application. We present the computing times demanded by two different problems for a variety of programs, including EMA and VIS. Finally, we present mass loss and mass accretion results for several simulations of galaxy-galaxy encounters performed with our implementation of the NBODY2 code.
KeywordsComputing Time Globular Cluster Softening Parameter Astronomical Society Astrophysical Journal
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- Aarseth, S.J. (1985) ‘Direct Methods for N-Body Simulations’, in J.W. Brackbill and B.J. Cohen (eds.), Multiple Time Scales, New York Academic, pp. 377–418.Google Scholar
- Carpintero, D.D. and Muzzio, J.C. (1988) ‘Disintegration of a Satellite that Orbits around a Galaxy’, II Regional Meeting on Extragalactic Astronomy (Córdoba, Argentina), in press.Google Scholar
- Muzzio, J.C. (1988). ‘Cluster Swapping’, in J.E. Grindlay and A.G. Davis Philip (eds.1, The Harlow-Shapley Symposium on Globular Cluster Systems in Galaxies, pp. 297–309.Google Scholar