NASA says its scientists have come up with a computer simulation that suggests if we want to understand dark matter, there's a unique place we should be looking — and it's deep inside black holes.
The simulations shows that particles of dark matter crashing into each other in the intense gravity possessed by a black hole would produce gamma-ray emissions that would be strong and observable.
It could reveal black matter that, although it is believed to account for the majority of the bulk of the universe, is paradoxically invisible because it doesn't emit, absorb or reflect visible light.
"While we don't yet know what dark matter is, we do know it interacts with the rest of the universe through gravity, which means it must accumulate around supermassive black holes," explains astrophysicist Jeremy Schnittman of NASA's Goddard Space Flight Center in Greenbelt, Maryland. "A black hole not only naturally concentrates dark matter particles, its gravitational force amplifies the energy and number of collisions that may produce gamma rays."
Writing in The Astrophysical Journal, Schnittman described the computer simulation he's come up with to recreate the orbits of particles in the hundreds upon millions within dark matter and the gamma-ray emissions they might produce as they collide in the neighborhood of a black hole.
The simulation is based on dark matter being in the form of Weakly Interacting Massive Particles — WIMPS — widely considered to be leading candidates of the substances of which dark matter consists.
Two WIMPS colliding would mutually annihilate each other, resulting in the most animated form of light: gamma-rays.
Scientists have long been searching for WIMPS by searching for the gamma-rays they could create, but collision of WIMPS are believed to be extremely rare under normal conditions.
However, conditions in the vicinity of black holes are anything but normal, they point out, and the theory is that they could serve as concentrators of dark matter — in other words, a natural laboratory more powerful and extreme than any that could be built on Earth — increasing both the rate and energy levels of WIMP collisions.
Schnittman says his research and his computer simulation are one more step toward a possible future day when scientists will see incontrovertible evidence of a WIMP annihilation signal emanating from dark matter in the vicinity of a supermassive black hole.
"The simulation tells us there is an astrophysically interesting signal we have the potential of detecting in the not too distant future, as gamma-ray telescopes improve," he says. "The next step is to create a framework where existing and future gamma-ray observations can be used to fine-tune both the particle physics and our models of black holes."
