Milky Way-like galaxies existed in early universe

Using a new, large-scale computer simulation, researchers have discovered that Milky Way-like galaxies may have existed in the early universe.

The simulation, created by physicists at Carnegie Mellon University and the University of California-Berkeley, shows that the early universe - a mere 500 million years after the Big Bang -- might have had more order and structure than previously thought.

"It is awe inspiring to think that galaxies much like our own existed when the universe was so young," said Tiziana Di Matteo, professor of physics at Carnegie Mellon.

The deepest Hubble Space Telescope observations have thus only covered small volumes of space and have found very irregular, clumpy galaxies at these early epochs.

"It is not surprising that in these small volumes some of the small galaxies do not have regular morphologies like large disk galaxies," Matteo added.

Similarly, numerical simulations have been limited in size so they have only made predictions for the smaller, clumpier galaxies at these early times.

Di Matteo and fellow physics professor Rupert Croft have long been at the forefront of simulation cosmology, completing some of the largest simulations ever created.

Their current simulation, called BlueTides, is 100 times larger than previous simulations.

They were surprised to find a number of disk galaxies in the universe at 500 million years post-Big Bang.

Since disk galaxies are so large and complex, most researchers assumed that they would take a very long time to form and would be rare, if they existed at all, in the early universe.

"Our simulation showed that the early universe might be far from being just this. It might contain beautiful symmetrical galaxies, like the Milky Way," Croft noted.

Their findings, forthcoming in The Astrophysical Journal Letters, will help guide researchers using next-generation telescopes as they search the sky for evidence of the first galaxies.