2012/07/31 by A. Hektor, Andi Hektor, Martti Raidal +3 · 2 citations
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Cluster (spacecraft) #Dark Matter and Cosmic Phenomena #Dark galaxy #Dark matter #Dark matter halo #Galaxy #Galaxy cluster #Galaxy groups and clusters #Hot dark matter #Radiation Detection and Scintillator Technologies #astro-ph.CO #astro-ph.HE #hep-ex #hep-ph
paper · pdf · doi:10.1088/2041-8205/762/2/l22
Double peak structure of the excess seen due to new Fermi-LAT energy resolution, in agreement with the Galactic centre data. More results available in web http://phys.hep.kbfi.ee/~andi/FermiLAT-lines/. One additional plot added to show correlation between signal and cluster brightness. Published version
arxiv created 2012/12/13 · openalex publication_date 2012/12/17 · arxiv updated 2015/06/05 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Using the Fermi Large Area Telescope (LAT) we search for spectral features in γ-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 3.6σ, 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.