Astronomers Think They've Detected Antimatter Signals From Beyond The Milky Way For The First Time

Astronomers reanalyzing the full INTEGRAL gamma-ray dataset report possible 511 keV annihilation signals outside the Milky Way.

The tentative detections are linked to Complex C and the Magellanic Stream, suggesting positrons may have escaped the galaxy before annihilating.

If confirmed, the result would imply the Milky Way produces and leaks more positrons than expected, revising antimatter and gamma-ray models.