Constraining annihilating dark matter by x-ray data

Understand

In the past decade, gamma-ray observations and radio observations put strong constraints on the parameters of dark matter annihilation.

• In this article, we suggest another robust way to constrain the parameters of dark matter annihilation.
• We expect that the electrons and positrons produced from dark matter annihilation would scatter with the cosmic microwave background photons and boost the photon energy to $\sim$ keV order.
• Based on the x-ray data from the Draco dwarf galaxy, the new constraints for some of the annihilation channels are generally tighter than the constraints obtained from 6 years of Fermi Large Area Telescope (Fermi-LAT) gamma-ray observations of the Milky Way dwarf spheroidal satellite galaxies.