Fermi 130 GeV gamma-ray excess and dark matter annihilation in sub-haloes and in the Galactic centre

Journal Article · Sat Sep 01 04:00:00 EDT 2012 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2012/09/032· OSTI ID:22279951

Tempel, Elmo; Hektor, Andi; Raidal, Martti ^[1]

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1. NICPB, Ravala 10, Tallinn 10143 (Estonia)

We analyze publicly available Fermi-LAT high-energy gamma-ray data and confirm the existence of clear spectral feature peaked at E{sub γ} = 130 GeV. Scanning over the Galaxy we identify several disconnected regions where the observed excess originates from. Our best optimized fit is obtained for the central region of Galaxy with a clear peak at 130 GeV with local statistical significance 4.5σ. The observed excess is not correlated with Fermi bubbles. We compute the photon spectra induced by dark matter annihilations into two and four standard model particles, the latter via two light intermediate states, and fit the spectra with data. Since our fits indicate sharper and higher signal peak than in the previous works, data favors dark matter direct two-body annihilation channels into photons or other channels giving only line-like spectra. If Einasto halo profile correctly predicts the central cusp of Galaxy, dark matter annihilation cross-section to two photons is of order ten percent of the standard thermal freeze-out cross-section. The large dark matter two-body annihilation cross-section to photons may signal a new resonance that should be searched for at the CERN LHC experiments.

• OSTI ID: 22279951
• Journal Information: Journal of Cosmology and Astroparticle Physics, Journal Name: Journal of Cosmology and Astroparticle Physics Journal Issue: 09 Vol. 2012; ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ANNIHILATION
ASTROPHYSICS
CERN LHC
COSMOLOGY
CROSS SECTIONS
GAMMA RADIATION
GEV RANGE
INTERMEDIATE STATE
MILKY WAY
NONLUMINOUS MATTER
RESONANCE
SIGNALS
STANDARD MODEL
TWO-BODY PROBLEM