Exploring Dark Matter with Milky Way substructure

TL;DR

This paper investigates how the Sommerfeld effect can significantly boost dark matter annihilation signals in the Milky Way's substructure, predicting detectable gamma-ray fluxes from dark clumps.

Contribution

It applies the Sommerfeld correction to a high-resolution simulation to quantify the enhancement of dark matter annihilation signals from substructures.

Findings

Annihilation luminosity from cold substructure can be boosted by orders of magnitude.

Predicted gamma-ray fluxes from dark clumps are within Fermi satellite detection capabilities.

Dark matter detection prospects are significantly improved by considering the Sommerfeld effect.

Abstract

The unambiguous detection of Galactic dark matter annihilation would unravel one of the most outstanding puzzles in particle physics and cosmology. Recent observations have motivated models in which the annihilation rate is boosted by the Sommerfeld effect, a non-perturbative enhancement arising from a long range attractive force. Here we apply the Sommerfeld correction to Via Lactea II, a high resolution N-body simulation of a Milky-Way-size galaxy, to investigate the phase-space structure of the Galactic halo. We show that the annihilation luminosity from kinematically cold substructure can be enhanced by orders of magnitude relative to previous calculations, leading to the prediction of gamma-ray fluxes from up to hundreds of dark clumps that should be detectable by the Fermi satellite.