Constraining the Sommerfeld enhancement with Cherenkov telescope observations of dwarf galaxies

Understand

The presence of dark matter in the halo of our galaxy could be revealed through indirect detection of annihilation products.

• Dark matter annihilation is one of the possible interpretations of the recent measured excesses in positron and electron fluxes, once boost factors of the order of 10^3 or more are taken into account.
• Such boost factors are actually achievable through the velocity-dependent Sommerfeld enhancement of the annihilation cross-section.
• Here we study the expected gamma-ray flux from two local dwarf galaxies for which air Cerenkov measurements are available, namely Draco and Sagittarius.