July 12, 2018
Four billion years ago, the incredible energy of a massive black hole at the center of a distant galaxy—a blazar—created a cosmic ray particle. As part of that process, it also formed a high-energy neutrino and a shower of gamma rays. In September, the IceCube Neutrino Observatory in Antarctica detected that neutrino. Combined with detections of gamma rays at collaborating institutions across the world, a series of IceCube neutrino detections provide solid evidence that cosmic rays derive from vast collapsed stars as they eat the material of their resident galaxies. The IceCube collaborators recognized these neutrinos for what they were thanks in part to a series of simulations they previously ran on the Pittsburgh Supercomputing Center’s Bridges system.