The X-ray emissions were discovered by chance beyond the Milky Way and no one really knows what is causing them. Jimmy Irwin wasn’t looking to get a paper published in Nature when he gave three of his University of Alabama undergraduate students an assignment.
He told them to comb through archived Chandra and XMM-Newton telescope data for examples of bright X-ray emissions coming from galaxies beyond the Milky Way. The catch was to find examples emanating from globular cluster galaxies, a type of very old galaxy. Continue reading Weird Deep Space X-Ray Flashes Stump Astronomers