Paper

Search for Dark Matter Annihilation Signals from the Fornax Galaxy Cluster with H.E.S.S

Jung, I, Katarzyński, K, Gerbig, D, Panter, M, Jamrozy, M, Skilton, J L, Steenkamp, R, Stycz, K, Holler, M, Sol, H, Schlickeiser, R, Daniel, M K, Kossakowski, R, Klochkov, D, Nguyen, N, Drury, L O'C, Fegan, S, Lennarz, D, P -O Petrucci, Maxted, N, Dubus, G, Renaud, M, Deil, C, de Jager, O C, Gérard, L, Jacholkowska, A, Schwemmer, S, Raue, M, Schulz, A, Heinzelmann, G, Medina, M C, Hofmann, W, de los Reyes, R, Terrier, R, Rieger, F, Hermann, G, Schwanke, U, Zdziarski, A A, Sheidaei, F, Stawarz, Ł, Sanchez, D A, Viana, A, Ostrowski, M, Barnacka, A, Stinzing, F, Jahn, C, Nekrassov, D, Moderski, R, Volpe, F, Sushch, I, Balzer, A, Füßling, M, White, R, Boisson, C, Dickinson, H J, McComb, T J L, Rosier-Lees, S, Becker, J, Espigat, P, Degrange, B, Conrad, J, Hoffmann, A, de Naurois, M, Zajczyk, A, Akhperjanian, A G, Zacharias, M, Khélifi, B, Fallon, L, ster, A, Carrigan, S, Rudak, B, Tluczykont, M, H -S Zechlin, Keogh, D, Zech, A, Chadwick, P M, Nedbal, D, Dalton, M, Sahakian, V, Venter, C, Hauser, M, Reimer, O, J -P Tavernet, Häffner, S, Brucker, J, Nolan, S J, Gallant, Y A, Lopatin, A, Davids, I D, Rowell, G, Kneiske, T, Reimer, A, Djannati-Ataï, A, Dutson, K, Ripken, J, Ruppe

2013

Overview

The Fornax galaxy cluster was observed with the High Energy Stereoscopic System (H.E.S.S.) for a total live time of 14.5 hours, searching for very-high-energy (VHE, E>100 GeV) gamma-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 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 gamma-ray flux, due to DM substructures of the DM host halo, or from the Sommerfeld effect, are studied. Additional gamma-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 ~ 10^-23cm^3s^-1, depending on the DM particle model and halo properties. Additional contribution from DM substructures can improve the upper limits on <\\sigma v> 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 <\\sigma v> ~ 10^-26cm^3s^-1.

• Publisher: Cornell University Library, arXiv.org
• Subject: Bremsstrahlung / Confidence intervals / Cross-sections / Dark matter / Density distribution / Elastic scattering / Galactic clusters / Galaxies / Gamma rays / Particle mass / Stereoscopy / Substructures / Supersymmetry