Evolution of star clusters with a mass distribution of binaries

The dynamical evolution of star clusters with an initial population of binaries strongly depends on the parameters of the bounded pairs. The authors performed computational simulation with direct N-body codes, on models with N = 300 objects, with initial fraction of 20% of binaries with the same orbital semi-axis and with a Salpeter mass spectrum. The results are compared with previous analysis on similar equal-mass star models. The calculation points out that binaries with different mass companions determine an enhanced and sudden expansion of the system with neither core collapse nor central mass segregation.