The Anisotropy of the Extragalactic Radio Background from Dark Matter Annihilation

Understand

Observations of the extragalactic radio background have uncovered a significant isotropic emission across multiple frequencies spanning from 22 MHz to 10 GHz.

• The intensity of this non-thermal emission component significantly exceeds the expected contribution from known astrophysical sources.
• Interestingly, models have indicated that the annihilation of dark matter particles may reproduce both the flux and spectrum of the excess.
• However, the lack of a measurable anisotropy in the residual emission remains challenging for both dark matter and standard astrophysical interpretations of the ARCADE-2 data.