Statistical interpretation of the spatial distribution of current 130 GeV gamma-ray line signal within the dark matter annihilation scenario

Abstract

Recently, several groups identified a tentative $\gamma$-ray line signal with energy $\sim 130$ GeV in the central Galaxy from the Fermi-LAT data. %The morphology study shows that the signal is consistent with dark matter %annihilation, but with an offset $\sim 220$ pc ($1.5^{\circ }$) of the %center from the Galactic center Sgr A${}^{\star }$, Such a $\gamma -$ray line can be interpreted as the signal of dark matter annihilation. However, the offset $\sim 220$ pc ($1.5^{\circ }$) of the center of the most prominent signal region from the Galactic center Sgr A${}^{\star }$ has been thought to challenge the dark matter annihilation interpretation. Considering the fact that such a 130 GeV $\gamma$-ray line signal consists of only $\sim 14$ photons, we suggest that the "imperfect" consistency of these photons with the expected dark matter distribution is due to the limited statistics. The offset will be smaller as more signal photons have been collected in the near future. Our Monte Carlo simulation supports the above speculation.

4 pages, 2 figures, Phys. Lett. B in press

References in corpus (6)

• A Tentative Gamma-Ray Line from Dark Matter Annihilation at the Fermi Large Area Telescope
• Strong Evidence for Gamma-ray Line Emission from the Inner Galaxy
• Spectral and spatial variations of the diffuse gamma-ray background in the vicinity of the Galactic plane and possible nature of the feature at 130 GeV
• Brightening the (130 GeV) Gamma-Ray Line
• Testing the 130 GeV gamma-ray line with high energy resolution detectors
• Mixed Wino-Axion Dark Matter in String/M Theory and the 130 GeV Gamma-line "Signal"

Cited by in corpus (3)

• Three Exceptions for Thermal Dark Matter with Enhanced Annihilation to Gamma Gamma
• Galactic Center Radio Constraints on Gamma-Ray Lines from Dark Matter Annihilation
• The 130 GeV Fingerprint of Right-Handed Neutrino Dark Matter