Fermi Gamma-ray Telescope tagged posts

Dark matter may come in two flavors—finally explaining why its signals appear in some galaxies but vanish in others. A mysterious glow of gamma rays at the center of the Milky Way has long hinted at dark matter, but the lack of similar signals in smaller dwarf galaxies has cast doubt on that idea. Now, researchers propose a bold twist: dark matter might not be a single particle at all, but a mix of two different types that must interact with each other to produce detectable signals.

Sometimes, not seeing somet...

In the heart of an active galaxy, matter falling toward a supermassive black hole generates jets of particles traveling near the speed of light. Image Credit: NASA’s Goddard Space Flight Center Scientific Visualization Studio

When the universe was young, a supermassive black hole – bloated to the bursting point with stupendous power – heaved out a jet of particle-infused energy that raced through the vastness of space at nearly the speed of light. Billions of years later, a trio of Clemson University scientists, led by College of Science astrophysicist Marco Ajello, has identified this black hole and 4 others similar to it that range in age from 1.4 billion to 1.9 billion years old...