THE DYNAMIC DECAY OF YOUNG FEW-BODY STELLAR-SYSTEMS - I - THE EFFECT OF A MASS-SPECTRUM FOR N = 3, 4, AND 5

We investigate the dynamic decay of nonhierarchical few-body systems, with an emphasis on applications to young stellar multiples formed by fragmenting cloud collapse. A chain regularization scheme is used to i ntegrate orbits for 300 or more crossing times in order to guarantee t hat most systems are fully decayed. In this paper, we consider cases w here the number N of point-mass stars is three, four, or five; and we explore effects of the stellar mass spectrum on the outcome in the low angular momentum limit. A novel classification scheme is introduced t o identify the remnant decay products, including singles, binaries, an d bound hierarchical multiples. The ensemble of final system configura tions is then analysed to determine mass and escape speed distribution s, and to characterize properties of the binary and triple stars forme d during the decay. Some statistical features of the endstates can be understood analytically using well-known principles of few-body dynami cs. Our results suggest observable signatures in and around star formi ng regions which would be expected if multiply fragmenting collapse is a common mode of star formation.