Search for dark matter annihilation signals from the Fornax galaxy cluster with H.E.S.S.

The Fornax galaxy cluster was observed with the High Energy Stereoscopic System for a total live time of 14.5 hr, searching for very high energy (VHE; E > 100GeV) γ-rays from dark matter (DM) annihilation. No significant signal was found in searches for point-like and extended emissions. Using several models of the DM density distribution, upper limits on the DM velocity-weighted annihilation cross-section langσvrang as a function of the DM particle mass are derived. Constraints are derived for different DM particle models, such as those arising from Kaluza-Klein and supersymmetric models. Various annihilation final states are considered. Possible enhancements of the DM annihilation γ-ray flux, due to DM substructures of the DM host halo, or from the Sommerfeld effect, are studied. Additional γ-ray contributions from internal bremsstrahlung and inverse Compton radiation are also discussed. For a DM particle mass of 1 TeV, the exclusion limits at 95% of confidence level reach values of langσvrang95% C.L. ~ 10–23 cm3 s–1, depending on the DM particle model and halo properties. Additional contribution from DM substructures can improve the upper limits on langσvrang by more than two orders of magnitude. At masses around 4.5 TeV, the enhancement by substructures and the Sommerfeld resonance effect results in a velocity-weighted annihilation cross-section upper limit at the level of langσvrang95% C.L. ~10–26 cm3 s–1.Fil: Abramowski, Ana Laura. Universitat Hamburg; AlemaniaFil: Acero, F.. Universidad Montpellier; FranciaFil: Aharonian, Felix A.. National Academy Of Sciences Of The Republic Of Armenia; Armenia. Max Planck Institut Fur Kernphysik; AlemaniaFil: Akhperjanian, A.G.. Yerevan Physics Institute; Armenia. National Academy Of Sciences Of The Republic Of Armenia; ArmeniaFil: Anton, G.. Universitat Erlangen-Nuremberg; AlemaniaFil: Balzer, A.. Universitat Erlangen-Nuremberg; AlemaniaFil: Barnacka, A.. Nicolaus Copernicus Astronomical Center; PoloniaFil: Barres De Almeida, U.. University Of Durham; Reino UnidoFil: Becherini, Y.. Université Paris Diderot - Paris 7; FranciaFil: Becker, J.. Ruhr Universität Bochum; AlemaniaFil: Behera, B.. Landessternwarte Heidelberg; AlemaniaFil: Bernlöhr, K.. Max Planck Institut Fur Kernphysik; AlemaniaFil: Birsin, E.. Humboldt-universitat Zu Berlin; AlemaniaFil: Biteau, J.. Laboratoire Leprince-Ringuet; FranciaFil: Bochow, A.. Max Planck Institut Fur Kernphysik; AlemaniaFil: Boisson, C.. Université Paris Diderot - Paris 7; FranciaFil: Bolmont, J.. Universite Pierre et Marie Curie; FranciaFil: Bordas, Paul. Universitat Tubingen; AlemaniaFil: Brucker, J.. Universitat Erlangen-Nuremberg; AlemaniaFil: Brun, F.. Laboratoire Leprince-Ringuet; FranciaFil: Brun, P.. CEA Saclay; FranciaFil: Bulik, T.. Uniwersytet Warszawski; ArgentinaFil: Büsching, I.. Ruhr Universität Bochum; AlemaniaFil: Carrigan, S.. Max Planck Institut Fur Kernphysik; AlemaniaFil: Casanova, S.. Ruhr Universität Bochum; AlemaniaFil: Cerruti, M.. Université Paris Diderot - Paris 7; FranciaFil: Chadwick, P.M.. University Of Durham; Reino UnidoFil: Charbonnier, A.. Universite Pierre et Marie Curie; FranciaFil: Chaves, R. C. G.. Max Planck Institut Fur Kernphysik; AlemaniaFil: Medina, Maria Clementina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; Argentina. CEA Saclay; Franci