A tentative gamma-ray line from Dark Matter annihilation at the Fermi Large Area Telescope
- Max-Planck-Institut für Physik, Föhringer Ring 6, 80805 München (Germany)
The observation of a gamma-ray line in the cosmic-ray fluxes would be a smoking-gun signature for dark matter annihilation or decay in the Universe. We present an improved search for such signatures in the data of the Fermi Large Area Telescope (LAT), concentrating on energies between 20 and 300 GeV. Besides updating to 43 months of data, we use a new data-driven technique to select optimized target regions depending on the profile of the Galactic dark matter halo. In regions close to the Galactic center, we find a 4.6σ indication for a gamma-ray line at E{sub γ} ≈ 130 GeV. When taking into account the look-elsewhere effect the significance of the observed excess is 3.2σ. If interpreted in terms of dark matter particles annihilating into a photon pair, the observations imply a dark matter mass of m{sub χ} = 129.8±2.4 {sup +7}{sub −13} GeV and a partial annihilation cross-section of (σv){sub χχ} {sub →} {sub γγ} = (1.27±0.32 {sup +0.18}{sub −0.28}) × 10{sup −27}cm{sup 3}s{sup −1} when using the Einasto dark matter profile. The evidence for the signal is based on about 50 photons; it will take a few years of additional data to clarify its existence.
- OSTI ID:
- 22279911
- Journal Information:
- Journal of Cosmology and Astroparticle Physics, Vol. 2012, Issue 08; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
- Country of Publication:
- United States
- Language:
- English
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