Extragalactic positron-annihilation hotspots might mean Milky Way produces far more positrons than thought

Positrons—the antimatter counterpart of electrons—are created in high-energy cosmic processes. When normal matter meets its antimatter counterpart, they annihilate, or vanish, and produce a distinctive 511 keV gamma-ray signal. Scientists use this signal to detect where these annihilations occur.

Originally published at Phys.org