A new technique leads to the discovery of two closely separated pairs of supermassive black holes in the early universe.
What is the source of the highest-energy cosmic rays in our Galaxy? We report here the observation of the ultra-high-energy gamma-ray emission from a stellar superbubble in the Cygnus region, powered by the massive stellar complex called Cygnus OB2 in an attempt to answer this question.
We report the first detection of gigaelectronvolt (GeV) gamma-rays from a Magnetar. High-energy gamma-rays were detected after the initial detection of a signal in the megaelectronvolt (MeV) band originated from a magnetar giant flare in the nearby Sculptor galaxy.