NASA Detects Mysterious X-Ray Signal 240 Million Light Years Away
NASA astronomers have detected a signal, characterized by a “spike of intensity at a very specific wavelength of X-ray light,” in the Perseus galaxy cluster, 240 million light years from Earth.
According to Gizmodo, NASA scientists don’t yet know what the origin of the signal is, but they theorize that it could possibly be related to the existence of dark matter, an elusive substance that neither absorbs nor emits light, but makes up much of the observable physical universe. The signal, which was detected using archival data from the Chandra x-ray observatory and the XMM-Newton mission, may be the result of the decay of sterile neutrinos, a type of particle that has been considered a candidate for dark matter. When XMM-Newton data was studied, NASA scientists observed the a similar spike of intensity at the same wavelength in 73 other galaxy clusters.
Esra Bulbul, lead author of a study on the signal who works at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, said that while dark matter is a “long-shot” explanation for the x-ray signal, “the pay-off would be huge if we’re right. So we’re going to keep testing this interpretation and see where it takes us,” according to Universe Today. While it is possible that the signal was caused by sterile neutrino decay, it is far from a sure thing, researchers stressed, pointing out that detection of the x-ray signal pushed both the Chandra and Newton observatories to the limits of their capabilities.
Study co-author Maxim Markevitch, of NASA’s Goddard Space Flight Center, said that while the signal could prove the existence of sterile neutrinos, researchers have much work ahead of them before they can claim such a discovery, though the possibility has them excited. According to Space.com, Adam Foster, another co-author of the study, said that the next step would be to combine data from the Chandra observatory with information gleaned by Japan’s Suzaku mission in an effort to determine if the x-ray signal is observable in even more galaxy clusters.
If the x-ray signal is indeed proof of sterile neutrinos, it wouldn’t be the first evidence that pointed to the existence of dark matter. As The Inquisitr previously reported, NASA scientists utilized an alpha magnetic spectrometer (a type of particle detector) attached to the international space station in order to detect positrons, which pointed to a “new physical phenomenon” that could be a sign of dark matter.
While the origin of the x-ray signal remains a mystery at this time, NASA scientists say that more data may be available after Astro-H, a Japanese observatory with a new, more precise type of x-ray detector, launches next year.
