Skip to Content

Consistency of dark matter interpretations of the 3.5 keV X-ray line.

Two groups have reported an anomalous X-ray line from galactic sources that is claimed to have no plausible atomic origin, whereas decaying dark matter could explain it. Other groups looking at different sources find only upper limits on the line strength, seeming to rule out decaying dark matter. I show how the seemingly conflicting observations can have a consistent interpretation in the context of models where dark matter inelastic scattering produces an excited state that decays into the ground state and the X-ray photon. The dark matter mass is only weakly constrained by the X-ray data, but possibly required to be heavier than 10 TeV by CMB constraints, unless the dark matter halo of the Milky Way is cored.