A long time ago in a galaxy half the universe away, a flood of high-energy gamma rays began its journey to Earth. When they arrived in April, NASA’s Fermi Gamma-ray Space Telescope caught the outburst, which helped two ground-based gamma-ray observatories detect some of the highest-energy light ever seen from a galaxy so distant. The observations provide a surprising look into the environment near a supermassive black hole at the galaxy’s center and offer a glimpse into the state of the cosmos 7 billion years ago.

“When we looked at all the data from this event, from gamma rays to radio, we realized the measurements told us something we didn’t expect about how the black hole produced this energy,” said Jonathan Biteau at the Nuclear Physics Institute of Orsay, France. He led the study of results from the Very Energetic Radiation Imaging Telescope Array System (VERITAS), a gamma-ray telescope in Arizona.