The Intergalactic Stellar Population from Mergers of Elliptical Galaxies
  with Dark Matter halos
  We present simulations of dry-merger encounters between pairs of elliptical
galaxies with dark matter halos. The aim of these simulations is to study the
intergalactic stellar populations produced in both parabolic and hyperbolic
encounters. We model progenitor galaxies with total-to-luminous mass ratios
M_T/M_L 3 and 11. The initial mass of the colliding galaxies are chosen so that
M_1/M_2 and 10. The model galaxies are populated by particles representing
stars, as in Stanghellini et al. (2006), and dark matter. Merger remnants
resulting from these encounters display a population of unbounded particles,
both dark and luminous. The number of particles becoming unbounded depends on
orbital configuration, with hyperbolic encounters producing a larger luminous
intracluster population than parabolic encounters. Furthermore, in simulations
with identical orbital parameters, a lower M_T/M_L of the colliding galaxies
produces a larger fraction of unbounded luminous particles. For each modeled
collision, the fraction of unbounded to initial stellar mass is the same in all
mass-bins considered, similarly to what we found previously by modeling
encounters of galaxies without dark halos. The fraction of intergalactic to
total luminosity resulting from our simulations is ~ 4% and ~ 6% for
dark-to-bright mass rations of 10 and 2 respectively. These unbounded-to-total
luminous fractions are down from 17 % that we had previously found in the case
of no dark halos. Our results are in broad agreement with intergalactic light
observed in groups of galaxies, while the results of our previous models
without dark halos better encompass observed intracluster populations. We
suggest a possible formation scenario of intergalactic stars.
