Though there are multiple classes of objects that are able to produce gamma-rays, the source of certain highly-energetic photons discovered as coming from the core of the Milky Way has yet to be established. Astrophysicists are currently trying to understand what may be producing the particles.
The gamma-rays were identified by the NASA Fermi Gamma-Ray Telescope, which recently produced a map of the high-energy sky. It managed to account for 67 percent of the energetic light it discovered, but astrophysicists are still having problems figuring out where the remaining third comes from.
“We have no idea what they are,” says astrophysicist Dave Thompson, from the NASA Goddard Space Flight Center (GSFC), in Greenbelt, Maryland. He adds that the study ruled out dark matter as a potential source for these extreme radiations.
If the elusive stuff were able to produce gamma-rays, then it would do so as a diffuse glow, seeing how it permeates everything, even the massive voids between galaxies and galactic clusters. The statement was made by Harvard-Smithsonian Center for Astrophysics (CfA) expert Douglas Finkbeiner.
While researchers don't yet know the source of the mysterious radiations, they were able to determine where the remaining portion of this high-energy light comes from. Apparently, blazars and pulsars play an important role in producing gamma-rays.
A blazar is defined as a very compact energy source that gets its fuel from a supermassive black hole. They are considered to be some of the most dangerous objects in space, and are divided in two categories – BL Lacertae objects (BL Lac) and Optically Violent Variable (OVV) quasars.
Pulsars are a type of fast-spinning neutron stars, which release jets of radio waves from their poles as they rotate. When oriented correctly in regards to Earth, we see these jets as if they were the beams of a lighthouse, which makes the stars appear to be pulsating.
Giant cosmic structures called Fermi bubbles are also important gamma-ray sources. These formations emanate from the core of the Milky Way, but what exactly causes them is still a mystery. Experts suspect that our galaxy's supermassive black hole may play a role in their synthesis, Daily Galaxy
Researchers managing Fermi say that they will continue to use this extremely sensitive telescope to conduct additional investigations of the night sky. These surveys may finally reveal objects or structures that may account for the extra amounts of gamma-rays.