Fermilab scientists help make major astrophysics discovery

Fermilab scientists have contributed to the discovery of the origin of cosmic rays, a feat they say will lead to a better understanding of galaxies.

An international collaboration of scientists will report evidence that the universe's highest-energy beams come from active areas containing black holes in an article Friday in Science magazine.

For the scientific community, it's the next step forward in understanding the composition and actions of the universe.

"It's one of the outstanding puzzles in astrophysics," said Fermilab scientist Henry Glass, who worked on the project. "It's pretty significant."

Cosmic rays are comprised of protons and atomic nuclei that travel at close to the speed of light into the Earth's atmosphere.

They were first observed in 1938 and recorded in 1991. They puzzled scientists with the extremely high amount of energy contained within them.

The energy produced by the rays is up to 100 million times the energy produced by Fermilab's Tevatron accelerator, currently the fastest particle accelerator in the world, Glass said.

"Nothing we ever build will be as powerful as that," he said.

About 370 scientists from 17 countries have worked for more than 20 years on the project, based at the 1,200-square mile Pierre Auger Observatory in Argentina.

It started tracking cosmic rays in January 2004.

Fermilab is the U.S. national office for the project, and about 10 scientists there have been working on it.

Minor cosmic rays are sent in different directions from magnetic fields, making it impossible to track their origin. The Auger lab is located on such a large campus in order to track the larger rays - ones that hit a square-foot area about once a century.

In the past three years, scientists have measured about 80 of those.

What they've found is that the energy is coming from reactions inside Active Galactic Nuclei, areas that contain active black holes.

The thought is that when black holes are swallowing dust and gas, some of the energy is being ejected back out, Glass said.

Black holes are at the center of most galaxies, as is the case with the Milky Way. That black hole is not active, however - much like a dormant vs. active volcano, Glass said.

The discovery should allow for new studies in the field of cosmic ray astronomy, specifically looking into where the rays come from and how they can accelerate particles at such a high rate of speed.

Scientists hope to build a second laboratory in Colorado, to have a lab in both the northern and southern hemispheres.

"In a sense, we've just opened the door," Glass said.