image: In Cygnus X-3, an accretion disk surrounding a black hole or neutron star orbits close to a hot, massive star. Gamma rays (purple, in this picture) likely arise when fast-moving electrons above and below the disk collide with the star's ultraviolet light. Fermi sees more of this emission when the disk is on the far side of the orbit. This image relates to an article that appeared in the Nov. 26 issue of Science Express, published by AAAS. The study, by Dr. A.A. Abdo at Naval Research Laboratory and the National Academy of Sciences in Washington, DC, and colleagues, was titled, "Modulated High-Energy Gamma-Ray Emission from the Microquasar Cygnus X-3." view more
Credit: Image courtesy of Walter Feimer, NASA/Goddard Space Flight Center