Simulated Universe Sheds Light on Dark Matter
This article is republished from HPCwire.
While philosophers debate whether our universe, and all of us in it, may exist solely within a giant computer simulation, scientists at Durham University turned the idea of a virtual universe into reality.
Hoping to gain a better understanding of the mechanisms that give rise to stars, galaxies and even dark matter, astronomers from Durham along with scientists from Leiden University in Holland have harnessed the power of two supercomputers for their research: Durham University’s Cosmology Machine (COSMA), and GENCI’s Curie.
The simulation project, called EAGLE (Evolution and Assembly of GaLaxies and their Environments), aims to improve upon past models that failed after their star clusters were found to bear little resemblance those in our universe – either because they were of the wrong size, too round of a shape, or included stars that were too old.
What astronomers hope will set EAGLE apart is its inclusion of stronger galactic winds that drive the cosmos by blowing away the gases that cradled stars in their infancy, but are not found in mature galaxies.
“The universe generated by the computer is just like the real thing,” says Durham University Professor Richard Bower, co-author of the EAGLE paper published in this month’s edition of the Monthly Notices of the Royal Astronomical Society.
“There are galaxies everywhere, with all the stages, sizes and colours I’ve seen with the world’s largest telescopes.”
With these results, researchers should be able to gain an even deeper understanding of how the universe developed from the Big Bang that took place 13.8 billion years ago.
“This is the start of a new era for us. We can now manipulate the conditions of the universe and study the evolution of galaxies throughout the past 14 billion years,” comments Dr. Rob Crain, a co-author from Liverpool John Moores University.
“It is incredible,” adds Bower. “In the EAGLE universe I can even press a button to make time run backwards.”
But EAGLE’s usefulness hasn’t ended there. The project may also offer provide a guiding light in the hunt for dark matter.
“I’ve been losing sleep over this for the last 30 years,” says Professor Carlos Frank, Director of Durham University’s Institute for Computational Cosmology.
“Dark matter is the key to everything we know about galaxies, but we still don’t know its exact nature.”
Estimated to account for nearly 85 percent of the total matter in the universe, dark matter is invisible to telescopes as it neither emits nor absorbs light, but is observed indirectly by its gravitational pull on other, visible matter.
Physicists theorize that clumps of dark matter called “halos” helped to form galaxies by trapping cosmic gas, and predicted that these halos should be found in abundance. Instead only a few dozen have been observed around the Milky Way, and there isn’t a galaxy in every halo as scientists had anticipated.
EAGLE has helped to explain this phenomenon, showing that millions of these halos failed to conceive galaxies in the simulation due to extreme heat that prevented the gas from cooling into stars.
The project “EAGLE – Evolution and Assembly of GaLaxies and their Environments” led by Joop Schaye of Leiden University, The Netherlands was awarded 39.8 million core hours on CURIE TN @ GENCI@CEA, France under the 6th PRACE Call for Proposals for Regular Access. Richard Bower presented this project at PRACEdays14 in Barcelona.