Meng Su, Douglas P. Finkbeiner
Using 3.7 years of Fermi-LAT data, we examine the diffuse gamma-ray emission in the inner Galaxy in the energy range 80 GeV < E < 200 GeV. We find a diffuse gamma-ray feature at ~110 GeV to ~140 GeV which can be modeled by a ~<4 degree FWHM Gaussian in the Galactic center. The morphology is not correlated with the recently discovered Fermi bubbles. The null hypothesis of zero intensity is ruled out by 5.0 sigma (3.7 sigma with trials factor). The energy spectrum of this structure is consistent with a single spectral line (at energy 127.0+-2.0 GeV with chi square = 4.48 for 4 d.o.f.). A pair of lines at 110.8+-4.4 GeV and 128.8+-2.7 GeV provides a marginally better fit (with chi square = 1.25 for 2 d.o.f.). The total luminosity of the structure is (3.2+-0.6)x10^(35) erg/s, or (1.7+-0.4)x10^(36) photons/sec. The observation is compatible with a 142 GeV WIMP annihilating through gamma-Z and gamma-h for m_h~130 GeV, as in the "Higgs in Space" scenario.
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http://arxiv.org/abs/1206.1616
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