Abramowski, A.Büsching, I.De Jager, O.C.Venter, C.Vorster, M.H.E.S.S. Collaboration2012-09-052012-09-052011Abramowski, A. et al. 2011. H.E.S.S. constraints on dark matter annihilations towards the Sculptor and Carina dwarf galaxies. Astroparticle physics, 34(8):608-616. [https://doi.org/10.1016/j.astropartphys.2010.12.006]0927-65051873-2852 (Online)http://hdl.handle.net/10394/7243https://doi.org/10.1016/j.astropartphys.2010.12.006The Sculptor and Carina dwarf spheroidal galaxies were observed with the H.E.S.S. Cherenkov telescope array between January 2008 and December 2009. The data sets consist of a total of 11.8 h and 14.8 h of high quality data, respectively. No gamma-ray signal was detected at the nominal positions of these galaxies above 220 GeV and 320 GeV, respectively. Upper limits on the gamma-ray fluxes at 95% CL assuming two forms for the spectral energy distribution (a power law shape and one derived from dark matter annihilation) are obtained at the level of 10-13-10-12 cm-2 s-1 in the TeV range. Constraints on the velocity weighted dark matter particle annihilation cross section for both Sculptor and Carina dwarf galaxies range from σʋ~ 10-21 cm3 s-1 down to σʋ i ~ 10-22 cm3 s-1 depending on the dark matter halo model used. Possible enhancements of the gamma-ray flux are studied: the Sommerfeld effect, which is found to exclude some dark matter particle masses, the internal Bremsstrahlung and clumps in the dark-matter halo distributions.enGamma-rays: observationsdark matterSommerfeld enhancementInternal BremsstrahlungSculptorCarinaDwarf spheroidal galaxyArticle