Supercomputers to Make Virtual Universes to See How Galaxies Form


Do we even know how the Milky Way formed? Clearly no. However, scientists at the University of Arizona are closer to finding out, thanks to a supercomputer simulation. The traditional ways of observation of the real galaxies only give us snapshots. This means that astronomers need to invent and then test different theories about the evolution of the galaxies.

In order to solve these problems, the team used a supercomputer to make millions of different universes. Each of them followed a different physical theory when it comes to how a galaxy should form.

On this computer, they can create many different universes, and then compare them to the actual one. This is how they find out the rules that the galaxy followed when they started to make their appearance. This was said by the author Peter Behroozi, who is an assistant professor at the UA Steward Observatory.

They simulated about 12 million galaxies

Each universe simulated by the computer has 12 million galaxies, and it represents about 400 million years after the Big Bang, and to the present day. The results that they get from the computers helped in solving a paradox: why galaxies stop from forming new stars even when they keep enough hydrogen gas? We are talking about the raw material from which they are born.

“As we go back earlier and earlier in the universe, we would expect the dark matter to be denser, and therefore the gas to be getting hotter and hotter,” said Behroozi. He also stated that this is actually bad when it comes to star formation. They had initially believed that many of the galaxies from the early universe should have stopped from forming new stars.

However, they found the opposite. Some galaxies of a specific size were more likely to form stars at a higher rate.



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