A search for a dark matter annihilation signal towards the Canis Major overdensity with H.E.S.S

• Published in: The Astrophysical journal 2009, Vol.691, p.175-181
• Main Authors: Aharonian, F., Akhperjanian, A.G., Barres de Almeida, U., Bazer-Bachi, A.R., Behera, B., Beilicke, M., Benbow, W., Bernlöhr, K., Boisson, C., Borrel, V., Braun, I., Brion, E., Brucker, J., Bühler, R., Bulik, T., Büsching, I., Boutelier, T., Carrigan, S., Chadwick, P.M., Chaves, R., Chounet, L.-M., Coignet, G., Cornils, R., Costamante, L., Dalton, M., Degrange, B., Dickinson, H.J., Djannati-Ataï, A., Domainko, W., Drury, L.O'C., Dubois, F., Dubus, G., Dyks, J., Egberts, K., Emmanoulopoulos, D., Espigat, P., Farnier, C., Feinstein, F., Fiasson, A., Förster, A., Fontaine, G., Füssling, M., Gabici, S., Gallant, Y.A., Gérard, L., Giebels, B., Glicenstein, J.F., Glück, B., Goret, P., Hadjichristidis, C., Hauser, D., Hauser, M., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J.A., Hoffmann, A., Hofmann, W., Holleran, M., Hoppe, S., Horns, D., Jacholkowska, A., de Jager, O.C., Jung, I., Katarzy'Nski, K., Kendziorra, E., Kerschhaggl, M., Khangulyan, D., Khélifi, B., Keogh, D., Komin, Nu, Kosack, K., Lamanna, G., Latham, I.J., Lenain, J.-P., Lohse, T., Martin, J.M., Martineau-Huynh, O., Marcowith, A., Masterson, C., Maurin, D., Mccomb, T.J.L., Moderski, R., Moulin, Emmanuel, Naumann-Godo, M., de Naurois, M., Nedbal, D., Nekrassov, D., Nolan, S.J., Ohm, S., Olive, J.-P., de Oña Wilhelmi, E., Orford, K.J., Osborne, J.L., Ostrowski, M., Panter, M., Pedaletti, G., Pelletier, G., Petrucci, P.-O., Pita, S.
• Format: Article
• Language: English
• Subjects: Astrophysics; Cosmology and Extra-Galactic Astrophysics; Physics; Sciences of the Universe
• ISSN: 0004-637X; 1538-4357
• DOI: 10.1088/0004-637X/691/1/175

A search for a dark matter (DM) annihilation signal into $\gamma$-rays toward the direction of the Canis Major (CMa) overdensity is presented. The nature of CMa is still controversial and one scenario represents it as a dwarf galaxy, making it an interesting candidate for DM annihilation searches. A total of 9.6 hours of high quality data were collected with the H.E.S.S. array of Imaging Atmospheric Cherenkov Telescopes (IACTs) and no evidence for a very high energy $\gamma$-ray signal is found. Upper limits on the CMa dwarf galaxy mass of the order of 10$^{9}$ M$_{\odot}$ are derived at the 95% C.L. assuming neutralino masses in the range 500 GeV - 10 TeV and relatively large annihilation cross-sections. Constraints on the velocity-weighted annihilation cross section $$, are calculated for specific WIMP scenarios, using a NFW model for the DM halo profile and taking advantage of numerical simulations of hierarchical structure formation. 95% C.L. exclusion limits of the order of 5 $\times$ 10$^{-24}$ cm$^{3}$ s$^{-1}$ are reached in the 500 GeV - 10 TeV DM particle mass interval, assuming a total halo mass of 3 $\times$ 10$^{8}$ M$_{\odot}$.