The Daily Mining Gazette - Published: Friday, November 09, 2007 Print Article | Close Window MTU playskey role in project By DAN SCHNEIDER, DMG Writer HOUGHTON — Scientists can now tell what direction the highest-energy cosmic rays are coming from. In an international astronomical project called the Pierre Auger Collaboration, scientists from 17 countries have identified Active Galactic Nuclei as the most probable source of the cosmic rays. That conclusion has been a long time coming. “We have been looking for almost 100 years for the sources of the cosmic rays that were discovered at the beginning of the 20th century,” Michigan Technological University Physics Professor David Nitz said. “This is the first time that anyone has been able to actually see where charged cosmic rays are coming from.” Electronic equipment developed at Tech played a key role in analyzing the cosmic rays. The Auger Collaboration’s findings are reported in Friday’s issue of the journal Science. The highest-energy particles are thought to be born in super-massive black holes in the Active Galactic Nuclei at the center of galaxies located hundreds of millions of light-years away from earth. According to Nitz, a galactic nuclei can make subatomic particles move so fast, it makes the best particle accelerators on earth look like snail farms. “How the black hole actually transforms the material around it into cosmic rays of energies that are 100 million times greater than we can create on earth is not understood, but now we have strong evidence that we should really look closely at the objects to see what this energy production process is,” Nitz said. The physical manifestation of the Auger Project is an array of 1,600 detectors spread over 1,200 square miles of Argentinean desert — a land area larger than the Keweenaw Peninsula. Brian Fick, and associate professor of physics at Tech, helped determine the location. “It’s got the right latitude, 35 degrees south, it’s got the right altitude, 1,400 meters, it’s flat, it’s dry, and there aren’t too many people,” Fick said. He explained the dryness of the location is important because of the fluorescence detectors used to calibrate the array. The 1,600 detectors record the cosmic rays that constantly pass through earth. Electronic equipment developed, programmed and tested at Tech identifies the highest-energy rays — the ones Nitz calls the most significant “high energy events” — and isolates them for in-depth analysis. Nitz said these “events” are rare occurrences in the general onrush of cosmic rays. It is the particles’ great speed that allows scientists to trace their source with a degree of accuracy. Nitz said the findings will allow scientists to begin to observe the universe based on cosmic rays, analogous to using telescopes to observe the universe through visible light. “One of the important things about this is it’s another window into astronomy,” Nitz said. “Now we can start to do astronomy with charged particles and every one of these windows allows us to learn additional information about the cosmos.” He called the work “basic science.” “We seek to understand how the universe works but one of the things we have not understood is how nature can accelerate these cosmic rays and so there’s a mystery there,” Nitz said. “By unravelling it, there may or may not be practical applications in the world, you never know. If you don’t do the basic research, you’re not going to be able to have the practical applications.” Nitz said four faculty at Tech, counting himself, have worked on the project and graduate and undergraduate students contributed to the work done at Tech. The next step in the collaboration is the development of a cosmic ray observatory in North America. Dan Schneider can be reached at dschneider@mininggazette.com