Search for dark matter annihilation signals from the Fornax galaxy cluster with H.E.S.S.
2012 (English)In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 750, no 2, 123- p.Article in journal (Refereed) Published
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 upsilon > 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 upsilon >(95% C.L.) similar to 10(-23) cm(3) s(-1), depending on the DM particle model and halo properties. Additional contribution from DM substructures can improve the upper limits on <sigma upsilon > 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 upsilon >(95% C.L.) similar to 10(-26) cm(3) s(-1).
Place, publisher, year, edition, pages
2012. Vol. 750, no 2, 123- p.
astroparticle physics, dark matter, galaxies: clusters: general, galaxies: clusters: individual (Fornax), gamma rays: galaxies: clusters, gamma rays: general
Astronomy, Astrophysics and Cosmology
IdentifiersURN: urn:nbn:se:kth:diva-95487DOI: 10.1088/0004-637X/750/2/123ISI: 000303446500037ScopusID: 2-s2.0-84860368084OAI: oai:DiVA.org:kth-95487DiVA: diva2:528680
QC 20120528. Correction in: Astrophysical Journal, 2014, vol. 783, issue. 1.
WOS: 0003349196000632012-05-282012-05-282014-06-11Bibliographically approved