X-ray signal from Milky Way’s halo eliminates some alternate explanations
A strange X-ray signal has popped up again in new measurements, raising hopes that it could be a sign of dark matter.
Data from NASA’s Chandra X-ray Observatory reveal an excess of X-rays at a particular energy, creating a bump on a plot, scientists report online at arXiv.org on January 29. The X-ray “line,” as it is known, could reveal the presence of dark matter — an unknown substance that scientists believe constitutes most of the matter in the cosmos.
While the X-ray line has been found previously using several different telescopes, some searches have come up empty (SN: 9/3/16, p. 17). The new observation strengthens the case that the odd feature is real, and eliminates some possible mundane explanations.
“This is a very exciting thing,” says astrophysicist Nico