These stars will begin popping off like a string of firecrackers as they self-destruct as supernovae. The band known as the Milky Way will be gone, but far in the future some astronomers might gaze out onto a starry sky and look all the way into the core of the new elliptical galaxy. They would have no clue that there were once two majestic spiral galaxies, called the Milky Way and Andromeda by a long forgotten civilization. This kind of process can studied using N-body simulations . Such simulations are gravitationally self-consistent.
Modern simulations can include up to a million particles.
Computers are of course doubling their processing speeds about every 18 months, and will do for several doubling times to come. This sequence shows star formation in a merger of equal mass disk galaxies. Time is shown in the upper left corner of each frame, with unit time corresponding to 13 million years. Time is shown in the upper left corner of each frame, with unit time corresponding to 13 million years. As the companion falls into the disk galaxy, it triggers a stong inflow of gas and ensuing burst of star formation in the central kiloparsec of the disk.