Potential gamma-ray signal could be evidence of dark matter

Scientific American : In April, Christoph Weniger of the GRAPPA Institute in Amsterdam examined public data from the Fermi Gamma-ray Space Telescope‘s primary instrument: the Large Area Telescope (LAT). He found evidence of a high-energy gamma-ray signal emanating from the galactic center. No known astronomical phenomenon could account for the signal and Weniger believed it could only have been caused by dark matter particle collisions. Now, the team members running the LAT have indicated that they, too, found a 135-GeV gamma-ray line coming from near the galactic core. However, Andrea Albert, one of the Fermi team members from the Ohio State University, says the signal only has a 3.35-sigma local significance. That means there is not yet definite evidence of a signal, and it could just be variation in the background or a data processing artifact. Albert also says that the team detected a similar, though even less significant, signal at the same energy level when the telescope looked at the outer rim of Earth’s atmosphere. If so, then both signals could be the result of some artifact of data collection or processing. Albert says that, within the next year, the team hopes to have enough evidence to determine whether the signal is real.