Illuminating the 130 GeV Gamma Line with Continuum Photons

TL;DR

This paper analyzes Fermi gamma-ray data to constrain the continuum photon spectrum associated with the 130 GeV line, providing bounds that challenge certain dark matter models as explanations.

Contribution

It offers the first robust, profile-independent bounds on the continuum photon flux linked to the 130 GeV gamma-ray line, excluding neutralino dark matter as a source.

Findings

Strong bounds on continuum to line photon ratio

Excludes neutralino dark matter as explanation

Constraints are independent of dark matter density profile uncertainties

Abstract

There is evidence for a 130 GeV gamma-ray line at the Galactic Center in the Fermi Large Area Telescope data. Dark matter candidates that explain this feature should also annihilate to Standard Model particles, resulting in a continuous spectrum of photons. To study this continuum, we analyze the Fermi data down to 5 GeV, restricted to the inner 3 degrees of the Galaxy. We place a strong bound on the ratio of continuum photons to monochromatic line photons that is independent of uncertainties in the dark matter density profile. The derived constraints exclude neutralino dark matter as an explanation for the line.