Excess of Gamma Rays (2 of 3) (IMAGE) DOE/SLAC National Accelerator Laboratory Caption When astrophysicists model the Milky Way's gamma-ray sources to the best of their knowledge, they are left with an excess glow at the galactic center. Some researchers have argued that the signal might hint at hypothetical dark matter particles. However, it could also have other cosmic origins. Credit NASA; A. Mellinger/Central Michigan University; T. Linden/University of Chicago Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.