Motivated by the closest major merger, the Antennae Galaxies (NGC4038/4039), we want to
improve our genetic algorithm based modeling code Minga (Theis 1999). The aim is to reveal the major interaction and
galaxy parameters, e.g. orbital information and halo properties of such
an equal mass merger system. Together with the sophisticated search strategy of
Minga, one needs fast and reliable models in order to investigate the high
dimensional parameter space of this problem. Therefore we use a restricted
N-body code which is based on the approach by Toomre & Toomre
(1972), however with some refinements like
consistent orbits of extended dark matter halos. Recently also dynamical friction was
included to this code (Petsch 2007). While a good
description for dynamical friction was found for mass ratios up to
q = 1/3 (Petsch & Theis 2008), major merger systems were only imperfectly remodeled. Here we show recent
improvements for a major merger system by including mass-loss and using NFW halos.