Unexpected Gamma-Ray Signal Discovered Outside Milky Way

Newfound Signal Potentially Linked to High-Energy Cosmic Rays, Deepening Astrophysical Mystery

Astronomers have discovered an unexpected and unexplained gamma-ray signal outside our Milky Way galaxy, according to data from NASA's Fermi Telescope.
The gamma-ray signal is located towards another unexplained feature in space, the source of some of the most energetic cosmic particles ever detected.
The team believes the newfound signal is related to these high-energy particles, or cosmic rays, deepening the mystery of their origins.
The gamma-ray feature may be similar to a characteristic of the cosmic microwave background (CMB), the oldest light in the universe.
The team's findings were presented at the 243rd meeting of the American Astronomical Society and published in The Astrophysical Journal Letters.