Movie: N-body Simulation of the Milky Way's inner gas dynamics

This movie shows the simultaneous evolution of the luminous stellar components (right) and the gas (left) in the inertial frame of the centre of mass. The bottom frames are face-on projections with 24 kpc on a side, and the top frames are longitude-latitude maps as seen from the Sun located 8 kpc below the centre in the former frames, covering |l|<50 deg and |b|<25 deg. A careful inspection of the movie betrays oscillations of the density centre.

These results come from a completely self-consistent hybrid particle-mesh and SPH N-body simulation of the Milky Way described in Fux(1997) and Fux (1999). The simulation involves over 3.8 million particles, including a dark halo component and 150000 gas particles. A stellar bar with a corotation radius of 4.5 kpc has formed from the initial axisymmetric conditons while the gas component was kept fixed. The movies start at t=1800 Myr, just at the moment when the gas is relaxed. The onset of the non-axisymmetric part of the live potential is done linearly during half a rotation period of the bar. The gas component is treated as an isothermal perfect gas with a sound speed of 10 km/s.

Credit: R. Fux, Geneva Observatory

http://obswww.unige.ch/~fux/hydro.htm