  Context. More than 60 planets have been discovered so far in systems that
harbour two stars, some of which have binary semi-major axes as small as 20 au.
It is well known that the formation of planets in such systems is strongly
influenced by the stellar components, since the protoplanetary disc and the
particles within are exposed to the gravitational influence of the binary.
However, the question on how self-gravitating protoplanetary bodies affect the
evolution of a radiative, circumprimary disc is still open. Aims. We present
our 2D hydrodynamical GPU-CPU code and study the interaction of several
thousands of self-gravitating particles with a viscous and radiative
circumprimary disc within a binary star system. To our knowledge this program
is the only one at the moment that is capable to handle this many particles and
to calculate their influence on each other and on the disc. Methods. We
performed hydrodynamical simulations of a circumstellar disc assuming the
binary system to be coplanar. Our gridbased staggered mesh code relies on ideas
from ZEUS-2D, where we implemented the FARGO algorithm and an additional energy
equation for the radiative cooling according to opacity tables. To treat
particle motion we used a parallelised version of the precise Bulirsch - Stoer
algorithm. Four models in total where computed taking into account (i) only
N-body interaction, (ii) N-body and disc interaction, (iii) the influence of
computational parameters (especially smoothing) on N-body interaction, and (iv)
the influence of a quiet low-eccentricity disc while running model (ii). The
impact velocities where measured at two different time intervals and were
compared. Results. We show that the combination of disc- and N-body
self-gravity can have a significant influence on the orbit evolution of roughly
Moon sized protoplanets.

Earth and Planetary Astrophysics