The MW and Andromeda will collide in future. This is predicted by some models. This simulation is showing how it will be, if we will observe that event by Hubble
Space Telescope (HST). The realistic initial conditions are constrained on observational data.

The fully Hydro-Simulation contains: SFR, SN feedback, metal line cooling, DM halo (NFW profile), bulge (Hernquist profile), stellar particles.

The formed stars are colored by mapping VBU bands to RGB color.

The instrument noise and PSF are taken from WFPC2 camera on HST.

Time span is from now to 10 Gigayear to future.

A.Khalatyan, AIP, 2007

Thanks to :
M.Steinmetz,
V.Springel,
G.Yepes