URBANA — Since Saturday, a camera atop the Andes Mountains in Chile has been taking pictures of galaxies far, far away while researchers in Urbana have been processing those images and preparing them for scientists to review — in the hopes of one day shedding light on mysterious "dark energy."
Called the Dark Energy Survey, the international collaboration involves at least 200 scientists from institutions such as the University of Illinois, Lawrence Berkeley National Laboratory, the University of Chicago, University of Pennsylvania, as well as researchers from Europe and South America.
At the center of the study is a 570-megapixel camera, said to be the largest digital camera in the world, which will snap pictures of galaxies and supernovas for 105 nights a year for five years. The camera, built at Fermilab National Accelerator Laboratory in Batavia, includes some components designed and built at the UI's Loomis Laboratory of Physics in Urbana. The camera was installed at the Cerro Tololo Inter-American Observatory in the Andes Mountains in Chile.
Dark energy is "the name for something we don't understand," said Robert Gruendl, research scientist with the UI's Department of Astronomy. About 15 years ago scientists attempting to measure the expansion of the universe found the universe was accelerating, meaning there has to be some force behind the acceleration, he said.
"What the (Dark Energy) Survey is trying to do is characterize the ... acceleration we are seeing so we can place limits on what may be causing it. Right now we call it dark energy," Gruendl said.
The survey, which started collecting images Aug. 31, will cover the Southern Hemisphere and follows up on the Sloan Digital Sky Survey, which focused on the Northern Hemisphere from a telescope in New Mexico. The Dark Energy Survey is expected to collect images of 300 million galaxies, 100,000 galaxy clusters and discover 4,000 new supernovae.
Before the scientists analyze these new images, scientists at the UI's National Center for Supercomputing Applications review the raw data, turning it into data projects scientists will be able to use in their research, said Don Petravick, project director with NCSA.
In a sense, it's kind of like when you take a photo with your iPhone — software in the phone processes the image before you see it, making it suitable for you to share with others, Petravick said. Something similar is going on with the Dark Energy Survey images but on a much more "exquisite" level, he said.
A full night of observing will produce about 18,000 images.
In the collaboration, there are about 35 people working on this first stage, including about 12 to 15 people at NCSA.
"We're excited to do this. It is a different kind of activity at NCSA," Petravick said. Instead of providing a supercomputer that researchers log into, NCSA also is providing personnel who are "embedded in this collaboration and are members of it," he said.
The first images are being processed now, and around this time next year Gruendl anticipates a release of data from the first year of collecting images, with some small, incremental releases made ahead of that date.
Illinois astronomers will analyze galaxy clusters and Illinois physicists will look at supernovae "to chart the expansion of the universe over time, and (look) at gravitational lensing to determine the history of the formation of structure (galaxies and galaxy clusters)," UI physics Professor Jon Thaler said in release.
"It's an exciting time in cosmology, when we can use observations of the distant universe to tell us about the fundamental nature of matter, energy, space and time," said Josh Frieman, director of the Dark Energy Survey with the U.S. Department of Energy's Fermi Lab, in a release.
The Dark Energy Survey receives funding from the Department of Energy, the National Science Foundation, the participating institutions and funding agencies in the United Kingdom, Spain, Brazil, Germany and Switzerland.
More information is available at http://www.darkenergysurvey.org