  We present a 3D N-body simulation of the Milky Way including 4*10^5 star- and
dark-like particles and 2*10^4 gas particles, initially distributed according
to an axisymmetric, observationally constrained, mass model. The whole system
is self-gravitating and the gas hydrodynamics is solved using the SPH method.
The simulation leads to the spontaneous formation of a central bar that
strongly affects the gas dynamics. We compute (l-V) diagrams for both the
gaseous and the stellar particles as a function of the angle of the bar with
respect to the observer and compare the results for the gas with HI and CO
observations.

Astrophysics