EVIDENCE FOR INDIRECT DETECTION OF DARK MATTER FROM GALAXY CLUSTERS IN FERMI {gamma}-RAY DATA

Journal Article · Thu Jan 10 04:00:00 EST 2013 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/762/2/L22· OSTI ID:22078345

Hektor, A; Raidal, M; Tempel, E ^[1]

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1. National Institute of Chemical Physics and Biophysics, Raevala 10, 10143 Tallinn(Estonia)

Using the Fermi Large Area Telescope (LAT) we search for spectral features in {gamma}-rays coming from regions corresponding to the 18 brightest nearby galaxy clusters determined by the magnitude of their signal line-of-sight integrals. We observe a double-peak-like excess over the diffuse power-law background at photon energies of 110 GeV and 130 GeV with a global statistical significance of up to 3.6{sigma}, independently confirming earlier claims of the same excess from the Galactic center. Interpreting this result as a signal of dark matter annihilations to two monochromatic photon channels in galaxy cluster halos, and fixing the annihilation cross-section from the Galactic center data, we determine the annihilation boost factor due to dark matter subhalos from the data. Our results contribute to a discrimination of the dark matter annihilations from astrophysical processes and from systematic detector effects, offering them as possible explanations for the Fermi-LAT excess.

• OSTI ID: 22078345
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 2 Vol. 762; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ANNIHILATION
ASTROPHYSICS
CROSS SECTIONS
DATA ANALYSIS
DETECTION
GALAXY CLUSTERS
GAMMA RADIATION
GEV RANGE
MONOCHROMATIC RADIATION
NONLUMINOUS MATTER
PHOTONS
SIGNALS
TELESCOPES