Supernovas W44 & IC 443 in Gamma Rays (image) DOE/SLAC National Accelerator Laboratory Caption In order to understand the origin and acceleration of cosmic ray protons, researchers used data from the Fermi Gamma-ray Space Telescope and targeted W44 and IC 443, two supernova remnants thousands of light years away. Both turned out to be strong sources of gamma rays, but not at energies below what neutral pion decay would produce -- the observational proof scientists had been looking for. Credit NASA/DOE/Fermi LAT Collaboration Usage Restrictions Please provide credit 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.