A parallel tree code

Abstract We describe a new implementation of a parallel N-body tree code. The code is load-balanced using the method of orthogonal recursive bisection to subdivide the N-body system into independent rectangular volumes each of which is mapped to a processor on a parallel computer. On the Cray T3D, the load balance is in the range of 70-90% depending on the problem size and number of processors. The code can handle simulations with > 10 million particles, roughly a factor of 10 greater than allowed on vectorized tree codes. Edmund Bertschinger