Dark matter factory
OK. If these dark matter axions convert into x-ray photons as a natural process, I would expect them to register as an x-ray emission band or elevated population of x-rays in an energy band above a comparatively flat background. Also, given that dark matter in the vicinity of the Milky Way is supposedly helping to spin the galaxy, I'd expect the x-rays to be spatially distributed to come from the plane of the Milky Way and not from above or below it.