It may look more like a young child’s art assignment than anything else, but this is in fact the best dark matter signal that scientists have ever recorded. Speaking to New Scientist, Dan Hooper from the Fermi National Laboratory gushed that “this is the most compelling signal we’ve had for dark matter particles — ever.”
It is in fact an extra-bright gamma ray burst that’s emanating from the galactic centre, which is already thought to be a region rich in dark matter.
By subtracting known background levels of gamma rays from the signals they were detecting, they found these extra gamma rays forming a 5000-light-year sphere around the galactic centre. While some critics suggest the rays could be a result of other celestial bodies — notably a pulsar — Hooper and his colleagues point out that the sphere’s size make that unlikely. He explains:
“At this point, there are no known or proposed astrophysical mechanisms or sources that can account for this emission. That doesn’t rule out things that no one’s thought of yet, but we’ve tried pretty hard to think of something without success.”
So, it seems more likely than ever that dark matter is a thing, and you’re looking at it in this image. The next step, say the researchers, is to try to spot the same phenomenon with Large Underground Xenon (LUX) detector in South Dakota. That device is so sensitive that it should be able to settle the debate; let’s wait see. [New Scientist]