  In this paper a new scalable hydrodynamic code GPUPEGAS (GPU-accelerated
PErformance Gas Astrophysic Simulation) for simulation of interacting galaxies
is proposed. The code is based on combination of Godunov method as well as on
the original implementation of FlIC method, specially adapted for
GPU-implementation. Fast Fourier Transform is used for Poisson equation
solution in GPUPEGAS. Software implementation of the above methods was tested
on classical gas dynamics problems, new Aksenov's test and classical
gravitational gas dynamics problems. Collisionless hydrodynamic approach was
used for modelling of stars and dark matter. The scalability of GPUPEGAS
computational accelerators is shown.
