VERITAS observations of the Segue 1 dwarf spheroidal galaxy (1110.4358v3)

Abstract: In the cosmological paradigm, cold dark matter dominates the mass content of the Universe and is present at every scale. Candidates for dark mater include many extensions of the standard model, with a Weakly Interacting Massive Particle (WIMP) in the mass range from 50 GeV to greater than 10 TeV. The self-annihilation of WIMPs in astrophysical regions of high dark matter density can produce secondary particles including Very High Energy (VHE) gamma rays with energies up to the dark matter particle mass. The VERITAS array of Cherenkov telescopes, designed for the detection of VHE gamma rays in the 100 GeV-10 TeV energy range, is an appropriate instrument for the detection of dark matter. Among the possible astrophysical targets, dwarf spheroidal galaxies (dSphs) of the Local Group are promising targets to search for the annihilation signature of dark matter due to their proximity and large dark matter content. We report here on extensive observations conducted by VERITAS on the nearby Segue 1 satellite galaxy, which is currently considered as one of the best dSphs for dark matter studies. The results are discussed in the framework of WIMP models, with a special emphasis on leptophilic DM models invoked to explain the recent cosmic ray lepton anomalies.