  So far, more than 130 extrasolar planets have been found in multiple stellar
systems. Dynamical simulations show that the outcome of the planetary formation
process can lead to different planetary architectures (i.e. location, size,
mass, and water content) when the star system is single or double. In the late
phase of planetary formation, when embryo-sized objects dominate the inner
region of the system, asteroids are also present and can provide additional
material for objects inside the habitable zone (HZ). In this study, we make a
comparison of several binary star systems and aim to show how efficient they
are at moving icy asteroids from beyond the snow line into orbits crossing the
HZ. We also analyze the influence of secular and mean motion resonances on the
water transport towards the HZ. Our study shows that small bodies also
participate in bearing a non-negligible amount of water to the HZ. The
proximity of a companion moving on an eccentric orbit increases the flux of
asteroids to the HZ, which could result in a more efficient water transport on
a short timescale, causing a heavy bombardment. In contrast to asteroids moving
under the gravitational perturbations of one G-type star and a gas giant, we
show that the presence of a companion star not only favors a faster depletion
of our disk of planetesimals, but can also bring 4-5 times more water into the
whole HZ. However, due to the secular resonance located either inside the HZ or
inside the asteroid belt, impacts between icy planetesimals from the disk and
big objects in the HZ can occur at high impact speed. Therefore, real collision
modeling using a GPU 3D-SPH code show that in reality, the water content of the
projectile is greatly reduced and therefore, also the water transported to
planets or embryos initially inside the HZ.
