SIMULATIONS OF SPHEROIDAL SYSTEMS WITH SUBSTRUCTURE - TREES IN FIELDS

We present a hybrid technique of N-body simulation to deal with collis ionless stellar systems having an inhomogeneous global structure. We c ombine a treecode and a self-consistent field code such that each of t he codes models a different component of the system being investigated . The treecode is suited to treatment of dynamically cold or clumpy co mponents, which may undergo significant evolution within a dynamically hot system. The hot system is appropriately evolved by the self-consi stent field code. This combined code is particularly suited to a numbe r of problems in galactic dynamics. Applications of the code to these problems are briefly discussed.