Searching for Dark Matter Annihilation from Milky Way Dwarf Spheroidal Galaxies with Six Years of Fermi Large Area Telescope Data

Ackermann, M.; Albert, A.; Anderson, B.; Atwood, W. B.; Baldini, L.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Bissaldi, E.; Blandford, R. D.; Bloom, E. D.; Bonino, R.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Bruel, P.; Buehler, R.; Caliandro, G. A.; Cameron, R. A.; Caputo, R.; Caragiulo, M.; Caraveo, P. A.; Cecchi, C.; Charles, E.; Chekhtman, A.; Chiang, J.; Chiaro, G.; Ciprini, S.; Claus, R.; Cohen Tanugi, J.; Conrad, J.; Cuoco, A.; Cutini, S.; D'Ammando, F.; De Angelis, A.; De Palma, F.; Desiante, R.; Digel, S. W.; Di Venere, L.; Drell, P. S.; Drlica Wagner, A.; Essig, R.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Focke, W. B.; Franckowiak, A.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giglietto, N.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Gomez Vargas, G. A.; Grenier, I. A.; Guiriec, S.; Gustafsson, M.; Hays, E.; Hewitt, J. W.; Horan, D.; Jogler, T.; Jóhannesson, G.; Kuss, M.; Larsson, S.; Latronico, L.; Li, J.; Li, L.; Llena Garde, M.; Longo, Francesco; Loparco, F.; Lubrano, P.; Malyshev, D.; Mayer, M.; Mazziotta, M. N.; Mcenery, J. E.; Meyer, M.; Michelson, P. F.; Mizuno, T.; Moiseev, A. A.; Monzani, M. E.; Morselli, A.; Murgia, S.; Nuss, E.; Ohsugi, T.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Perkins, J. S.; Pesce Rollins, M.; Piron, F.; Pivato, G.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Reimer, A.; Reimer, O.; Ritz, S.; Sánchez Conde, M.; Schulz, A.; Sehgal, N.; Sgrò, C.; Siskind, E. J.; Spada, F.; Spandre, G.; Spinelli, P.; Strigari, L.; Tajima, H.; Takahashi, H.; Thayer, J. B.; Tibaldo, L.; Torres, D. F.; Troja, E.; Vianello, G.; Werner, M.; Winer, B. L.; Wood, K. S.; Wood, M.; Zaharijas, G.; Zimmer, S.

doi:10.1103/PhysRevLett.115.231301

The dwarf spheroidal satellite galaxies (dSphs) of the Milky Way are some of the most dark matter (DM) dominated objects known. We report on γ -ray observations of Milky Way dSphs based on six years of Fermi Large Area Telescope data processed with the new Pass8 event-level analysis. None of the dSphs are significantly detected in γ rays, and we present upper limits on the DM annihilation cross section from a combined analysis of 15 dSphs. These constraints are among the strongest and most robust to date and lie below the canonical thermal relic cross section for DM of mass ≲100 GeV annihilating via quark and τ -lepton channels.

Searching for Dark Matter Annihilation from Milky Way Dwarf Spheroidal Galaxies with Six Years of Fermi Large Area Telescope Data / Ackermann, M., Albert, A., Anderson, B., Atwood, W.B., Baldini, L., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bissaldi, E., Blandford, R.D., Bloom, E.D., Bonino, R., Bottacini, E., Brandt, T.J., Bregeon, J., Bruel, P., Buehler, R., Caliandro, G.A., Cameron, R.A., et al.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 115:23(2015), pp. 231301.231301-1-231301.231301-8. [10.1103/PhysRevLett.115.231301]