Thanks to data from two different spacecraft, scientists may be getting a rare signal of the invisible material that makes up most of the universe: dark matter.
According to Space.com, newly detected X-ray emissions from more than 70 galaxy clusters could be produced by dark matter. Authors of a new study based their work on data from NASA's Chandra X-Ray Observatory and the European Space Agency's XMM-Newton Satellite.
Dark matter is tricky to pick out because it does not emit light nor does it absorb it, but it reveals itself when its gravity pulls at tangible normal matter. Even though dark matter is mostly a mystery, many experts believe it makes up at least 80 percent of the universe.
"We know that the dark matter explanation is a long shot, but the payoff would be huge if we're right," study lead author Esra Bulbul, of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Mass., said in a press release. "So we're going to keep testing this interpretation and see where it takes us."
The spike in X-ray emissions the researchers observed brought both spacecraft to the limit of the sensitivity meters, which all but rules out the possibility the readings were generated by sterile neutrinos. In past studies, Space.com reported, scientists have suggested that sterile neutrinos could emit X-rays when they decay.
"We have a lot of work to do before we can claim, with any confidence, that we've found sterile neutrinos," study co-author Maxim Markevitch, of NASA's Goddard Space Flight Center in Greenbelt, Md., said in the release. "But just the possibility of finding them has us very excited."
The researchers published their work in the Astrophysical Journal.
"Our next step is to combine data from Chandra and JAXA's Suzaku mission for a large number of galaxy clusters to see if we find the same X-ray signal," study co-author Adam Foster, also of CfA, said in the release. "There are lots of ideas out there about what these data could represent. We may not know for certain until Astro-H launches, with a new type of X-ray detector that will be able to measure the line with more precision than currently possible."
