The Hunt for Dark Matter Continues: Supercomputer Simulations Chart the Evolution of the Local Universe
Astronomers have discovered new clues when it comes to the hunt for dark matter. They've created supercomputer simulations that show the evolution of our "local universe" from the Big Bang to the present day. The new simulations could improve the understanding of dark matter.
Dark matter is a somewhat mysterious substance that is believed to make up about 85 percent of the mass of the universe. Although it makes up so much of the universe, though, scientists know surprisingly little about it. They believe that clumps of dark matter, or halos, that emerged from the early universe trapped intergalactic gas and became the birthplace of galaxies.
"Dark matter is the key to everything we know about galaxies, but we still don't know its exact nature," said Carlos Frenk, one of the researchers, in a news release. "Understanding how galaxies formed holds the key to the dark matter mystery."
Theory actually predicts that our own cosmic neighborhood should be teeming with millions of small halos, but only a few dozen small galaxies have been spotted around the Milky Way. Obviously, there can't be a galaxy in every halo, and that's something that the researchers wanted to investigate.
In this case, the simulations showed how and why millions of halos around our galaxy failed to produce galaxy. The gas that would have made the galaxies was sterilized by the heat of the first stars that formed in the universe and was prevented from cooling and turning into stars. A few halos combated this by growing early and fast enough to hold onto their gas and form galaxies.
"We have learned that most dark matter halos are quite different from the 'chosen few' that are lit up by starlight," said Frenk. "Thanks to our simulations we know that if our theories of dark matter are correct then the universe around us should be full of halos that failed to make a galaxy. Perhaps astronomers will one day figure out a way to find them."
The findings will be presented at the Royal Astronomical Society's National Astronomy Meeting in Portsmouth on June 26.