  We present N-body simulations of elliptical galaxy encounters into dry
mergers to study the resulting unbound intergalactic stellar population, in
particular that of the post-Main Sequence stars. The systems studied are pairs
of spherical galaxies without dark halos. The stellar content of the model
galaxies is distributed into mass-bins representing low- and intermediate-mass
stars (0.85 -- 8 solar masses) according to Salpeter's initial mass function.
Our models follow the dynamical evolution of galaxy encounters colliding
head-on from initial low-energy parabolic or high-energy mildly-hyperbolic
orbits, and for a choice of initial-mass ratios. The merging models with
initial parabolic orbits have M2/M1 =1 and 10, and they leave behind
respectively 5.5 % and 10 % of the total initial mass as unbound stellar mass.
The merging model with initial hyperbolic orbit has M2/M1 =1, and leaves behind
21 % of its initial stellar mass as unbound mass, showing that the efficiency
in producing intergalactic stars through a high-energy hyperbolic encounter is
about four times than through a parabolic encounter of the same initial mass
ratio. By assuming that all progenitor galaxies as well as the merger remnants
are homologous systems we obtained that the intergalactic starlight is 17 % and
28 % of the total starlight respectively for the parabolic and hyperbolic
encounters with M2/M1 =1. In all models, different mass stars have the same
probability of becoming unbound and feeding the intergalactic stellar
population.
