Chuck Bednar for redOrbit.com – Your Universe Online

An unusual photon emission in X-ray data originating from space could be evidence for the existence of a dark matter particle, researchers from the Swiss Federal Institute of Technology in Lausanne (EPFL) report in a new study.

The signal, discovered by scientists working in the EPFL’s Laboratory of Particle Physics and Cosmology (LPPC) and colleagues from Leiden University in the Netherlands, could be the first tangible evidence of the mysterious substance that neither emits or absorbs light and is believed to account for unexplainable gravitational effects.

To this point, dark matter has been considered a purely hypothetical substance, but after sifting through a large quantity of X-ray data, the researchers believe they have identified the signal of a lone dark matter particle. Their findings will be published next week in the journal Physical Review Letters.

“When physicists study the dynamics of galaxies and the movement of stars, they are confronted with a mystery,” the EPFL explained in a statement Thursday. “If they only take visible matter into account, their equations simply don’t add up: the elements that can be observed are not sufficient to explain the rotation of objects and the existing gravitational forces. There is something missing.”

For this reason, experts have determined that there must be some invisible type of matter that does not interact with light, but does interact through gravitational forces. This so-called dark matter does not operate under any of the standard models of physics except through gravitational force, but makes up about 80 percent of the universe.

Two teams of scientists have recently detected the highly-anticipated signal, including one led by EPFL scientist Oleg Ruchayskiy and Leiden University professor Alexey Boyarsky. They made the discovery after analyzing X-rays emitted by the Perseus galaxy cluster and the Andromeda galaxy and collected using the ESA’s XMM-Newton telescope. After eliminating those coming from known particles and atoms, one noteworthy anomaly remained.

“All atoms emit a distinct pattern of light called a spectrum which is how astrophysicists can determine what planets and stars are made from at great distances,” explained Sarah Knapton of Science Editor with The Telegraph. Yet when they studied the X-ray spectrum, they found spikes where nothing should exist, a signal appearing as “a weak, atypical photon emission that could not be attributed to any known form of matter.”

Ruchayskiy told Knapton that the signal’s distribution within the galaxy corresponded precisely with what they were expecting from dark matter, “concentrated and intense in the center of objects and weaker and diffuse on the edges.” If the discovery, which resulted from a photon emitted due to the destruction of a hypothetical particle (possibly a sterile neutrino) is verified, it “could usher in a new era in astronomy,” he added in a statement.

“Dark matter is everywhere, though it’s very hard to catch. Everybody is looking for it and this may be the first sign,” added Boyarsky. “Confirmation of this discovery may lead to construction of new telescopes specially designed for studying the signals from dark matter particles. We will know where to look in order to trace dark structures in space and will be able to reconstruct how the universe has formed.”

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