The Cerro Tololo Inter-American Observatory in Chile. Courtesy of Fermilab Media Services.
The work of Ohio State scientists is playing a big role in providing new information about a few of the universe’s longstanding questions.
On Aug. 3, a team of around 400 international astrophysicists, with the help of Ohio State’s Center of Cosmology and Astro-Particle Physics, released a map of the universe that explains some of space’s biggest mysteries such as the development of the universe and the existence of dark matter and energy.
Twenty-six percent of the current universe is comprised of dark matter, a material that composes most of the mass in the universe, according to first-year results from the group named Dark Energy Survey. Another 70 percent is dark energy, which is the cause for the expansion of the universe.
“There is no understanding of how this works,” said Klaus Honscheid, a physics professor and leader of Ohio State’s DES group. “This[map] will shed some light on the behavior of dark energy and dark matter.”
Professor Klaus Honscheid next to the Dark Energy Camera at the Cerro Tololo Inter-American Observatory in Chile. Courtesy of T. Abbott, Cerro Tololo Inter-American Observatory.
To make these observations, DES used images taken by a 570-megapixel Dark Energy Camera — which is about the size of an average car — at the Cerro Tololo Inter-American Observatory in Chile.
Honscheid said Ohio State’s team helped construct the camera, not only physically, but also in creating algorithms to help clean images for observation.
The camera uses gravitational lensing, a process through which images are used to show where dark matter, a material that has yet to be directly observed by scientists, is located by measuring how light from background galaxies is refracted by dark matter in the foreground of the image.
“Where there are galaxies there must also be dark matter,” said Michael Troxel, a post-doctoral fellow at Ohio State’s Center of Cosmology and Astro-Particle Physics.
By then comparing the images to simulations based on cosmic microwave background, which is light that remains from around 400,000 years ago after the Big Bang, scientists can predict how the universe looks with a 7-percent margin of error.
The remains of the 400,000-year-old light can also allow for predictions of what the universe looked like billions of years ago.
“These are the seeds that developed into galaxies and stars and eventually you and me,” Honscheid said.
John Beacom, director of the Center for Cosmology and Astro-Particle Physics, said the project might not be immediately practical, but it is the first step to understanding from what the universe is made.
There is so much more information in these images, Honscheid said, and there is an enormous amount of research still to be done.
The DES is in the midst of its fifth observation season, which will run through February.
