SEARCH FOR DARK MATTER ANNIHILATION SIGNALS FROM THE FORNAX GALAXY CLUSTER WITH H.E.S.S

Journal Article · Thu May 10 04:00:00 EDT 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/750/2/123· OSTI ID:22034498

Abramowski, A ^[1]; Acero, F ^[2]; Aharonian, F; Bernloehr, K; Bochow, A ^[3]; Akhperjanian, A G ^[4]; Anton, G; Balzer, A; Brucker, J ^[5]; Barnacka, A ^[6]; Barres de Almeida, U ^[7]; Becherini, Y ^[8]; Becker, J ^[9]; Behera, B ^[10]; Birsin, E ^[11]; Biteau, J; Brun, F ^[12]; Boisson, C ^[13]; Bolmont, J ^[14]; Bordas, P ^[15] ; others, and

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1. Institut fuer Experimentalphysik, Universitaet Hamburg, Luruper Chaussee 149, D 22761 Hamburg (Germany)
2. Laboratoire de Physique Theorique et Astroparticules, Universite Montpellier 2, CNRS/IN2P3, CC 70, Place Eugene Bataillon, F-34095 Montpellier Cedex 5 (France)
3. Max-Planck-Institut fuer Kernphysik, P.O. Box 103980, D 69029 Heidelberg (Germany)
4. National Academy of Sciences of the Republic of Armenia, Yerevan (Armenia)
5. Physikalisches Institut, Universitaet Erlangen-Nuernberg, Erwin-Rommel-Str. 1, D 91058 Erlangen (Germany)
6. Nicolaus Copernicus Astronomical Center, ul. Bartycka 18, 00-716 Warsaw (Poland)
7. Department of Physics, University of Durham, South Road, Durham DH1 3LE (United Kingdom)
8. Astroparticule et Cosmologie (APC), CNRS, Universite Paris 7 Denis Diderot, 10, rue Alice Domon et Leonie Duquet, F-75205 Paris Cedex 13 (France)
9. Institut fuer Theoretische Physik, Lehrstuhl IV: Weltraum und Astrophysik, Ruhr-Universitaet Bochum, D 44780 Bochum (Germany)
10. Landessternwarte, Universitaet Heidelberg, Koenigstuhl, D 69117 Heidelberg (Germany)
11. Institut fuer Physik, Humboldt-Universitaet zu Berlin, Newtonstr. 15, D 12489 Berlin (Germany)
12. Laboratoire Leprince-Ringuet, Ecole Polytechnique, CNRS/IN2P3, F-91128 Palaiseau (France)
13. LUTH, Observatoire de Paris, CNRS, Universite Paris Diderot, 5 Place Jules Janssen, 92190 Meudon (France)
14. LPNHE, Universite Pierre et Marie Curie Paris 6, Universite Denis Diderot Paris 7, CNRS/IN2P3, 4 Place Jussieu, F-75252, Paris Cedex 5 (France)
15. Institut fuer Astronomie und Astrophysik, Universitaet Tuebingen, Sand 1, D 72076 Tuebingen (Germany)

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) {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 ({sigma}v) 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 ({sigma}v){sup 95%C.L.} {approx} 10{sup -23} cm{sup 3} s{sup -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){sup 95%C.L.} {approx}10{sup -26} cm{sup 3} s{sup -1}.

• OSTI ID: 22034498
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 750; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ANNIHILATION
ASTROPHYSICS
CROSS SECTIONS
DEAD TIME
DENSITY
GALAXY CLUSTERS
GAMMA RADIATION
INTERNAL BREMSSTRAHLUNG
KALUZA-KLEIN THEORY
NONLUMINOUS MATTER
PARTICLE MODELS
PHOTON EMISSION
REST MASS
SUPERSYMMETRY
TEV RANGE