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  • 1. A. Madsen, Kevin
    et al.
    J. Bergholtz, Emil
    Stockholm University, Faculty of Science, Department of Physics.
    Brouwer, Piet W.
    Josephson effect in a Weyl SNS junction2017In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 95, no 6, article id 064511Article in journal (Refereed)
    Abstract [en]

    We calculate the Josephson current density j (phi) for a Weyl superconductor-normal-metal-superconductor junction for which the outer terminals are superconducting Weylmetals and the normal layer is a Weyl (semi) metal. We describe the Weyl (semi) metal using a simple model with two Weyl points. The model has broken time-reversal symmetry, but inversion symmetry is present. We calculate the Josephson current for both zero and finite temperature for the two pairing mechanisms inside the superconductors that have been proposed in the literature, zero-momentum BCS-like pairing and finite-momentum FFLO-like pairing, and assuming the short-junction limit. For both pairing types we find that the current is proportional to the normal-state junction conductivity, with a proportionality coefficient that shows quantitative differences between the two pairing mechanisms. The current for the BCS-like pairing is found to be independent of the chemical potential, whereas the current for the FFLO-like pairing is not.

  • 2.
    A. Zheltukhin, A
    Stockholm University, Faculty of Science, Department of Physics.
    Unification of twistors and Ramond vectors2007In: Physics letters B, Vol. 658, p. 82-Article in journal (Refereed)
  • 3. Aad, G.
    et al.
    Abbott, B.
    Abdallah, J.
    Gellerstedt, Karl
    Stockholm University, Faculty of Science, Department of Physics.
    Measurement of the top quark pair production cross section with ATLAS in pp collisions at √s = 7 TeV in dilepton final states2011Report (Other academic)
    Abstract [en]

    A measurement is presented of the production cross section of top quark pairs (σ_{\ttbar{}}) in proton-proton (pp) collisions at √s = 7 TeV recorded with the ATLAS detector at the CERN Large Hadron Collider. Using a data sample of 35 pb−1, candidate events are selected in the dilepton topology with large missing transverse energy, \met{}, and at least two jets.

    A baseline analysis employing kinematic properties of the candidate events to separate the signal from background and using data-driven techniques to determine the most important backgrounds, results in a measurement ofσ_{\ttbar{}} = 173 ± 22(stat.)+18 −16(syst.)+8 −7(lum.) pb,

    where the three uncertainties are from statistics, systematics and integrated luminosity, respectively.

    We also perform a cross section measurement requiring at least one b-tagged jet and a looser kinematic selection that increases the signal-to-background ratio, yielding

    σ_{\ttbar{}} = 171 ± 22(stat.)+21 -16(syst.)+7 −6(lum.) pb.

    Additional studies are performed to corroborate these measurements; a technique that normalizes the \ttbar{} signal yield to the measured rate of Z decays, a two-dimensional template shape fit using the \met{} vs the number of jets to simultaneously measure the production cross sections of \ttbar{}, WW and Z → ττ final states, and a simultaneous measurement of σ_{\ttbar{}} and the b-tagging efficiency using the distribution of the number of tagged jets in each event.

    All the measurements are in good agreement with each other and the Standard Model prediction.

  • 4. Aad, G.
    et al.
    Åsman, Barbro
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    Clément, Christophe
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Eriksson, Daniel
    Stockholm University, Faculty of Science, Department of Physics.
    Gellerstedt, Karl
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hellman, Sten
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hidvégi, Attila
    Stockholm University, Faculty of Science, Department of Physics.
    Holmgren, Sven-Olof
    Stockholm University, Faculty of Science, Department of Physics.
    Johansen, Marianne
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Johansson, K. Erik
    Stockholm University, Faculty of Science, Department of Physics.
    Jon-And, Kerstin
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Lesser, Jonas
    Stockholm University, Faculty of Science, Department of Physics.
    Milstead, David A.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Nordkvist, Björn
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Ohm, Christian C.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Ramstedt, Magnus
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Selldén, Björn
    Stockholm University, Faculty of Science, Department of Physics.
    Silverstein, Samuel B.
    Stockholm University, Faculty of Science, Department of Physics.
    Sjölin, Jörgen
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Tylmad, Maja
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Yang, Zhaoyu
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Zutshi, V.
    Search for New Particles in Two-Jet Final States in 7 TeV Proton-Proton Collisions with the ATLAS Detector at the LHC2010In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 105, no 16, p. 161801-Article in journal (Refereed)
    Abstract [en]

    A search for new heavy particles manifested as resonances in two-jet final states is presented. The data were produced in 7 TeV proton-proton collisions by the LHC and correspond to an integrated luminosity of 315 nb(-1) collected by the ATLAS detector. No resonances were observed. Upper limits were set on the product of cross section and signal acceptance for excited-quark (q*) production as a function of q* mass. These exclude at the 95% C. L. the q* mass interval 0: 30< m(q)*< 1:26 TeV, extending the reach of previous experiments.

  • 5. Aalbers, J.
    et al.
    Agostini, F.
    Alfonsi, M.
    Amaro, F. D.
    Amsler, C.
    Aprile, E.
    Arazi, L.
    Arneodo, F.
    Barrow, P.
    Baudis, L.
    Benabderrahmane, M. L.
    Berger, T.
    Beskers, B.
    Breskin, A.
    Breur, P. A.
    Brown, A.
    Brown, E.
    Bruenner, S.
    Bruno, G.
    Budnik, R.
    Butikofer, L.
    Calvén, Jakob
    Stockholm University, Faculty of Science, Department of Physics.
    Cardoso, J. M. R.
    Cichon, D.
    Coderre, D.
    Colijn, A. P.
    Conrad, Jan
    Stockholm University, Faculty of Science, Department of Physics.
    Cussonneau, J. P.
    Decowski, M. P.
    Diglio, S.
    Drexlin, G.
    Duchovni, E.
    Erdal, E.
    Eurin, G.
    Ferella, Alfredo
    Stockholm University, Faculty of Science, Department of Physics.
    Fieguth, A.
    Fulgione, W.
    Rosso, A. Gallo
    Di Gangi, P.
    Di Giovanni, A.
    Galloway, M.
    Garbini, M.
    Geis, C.
    Glueck, F.
    Grandi, L.
    Greene, Z.
    Grignon, C.
    Hasterok, C.
    Hannen, V.
    Hogenbirk, E.
    Howlett, J.
    Hilk, D.
    Hils, C.
    James, A.
    Kaminsky, B.
    Kazama, S.
    Kilminster, B.
    Kish, A.
    Krauss, L. M.
    Landsman, H.
    Lang, R. F.
    Lin, Q.
    Linde, F. L.
    Lindemann, S.
    Lindner, M.
    Lopes, J. A. M.
    Undagoitia, T. Marrodan
    Masbou, J.
    Massoli, F. V.
    Mayani, D.
    Messina, M.
    Micheneau, K.
    Molinario, A.
    Morå, Knut D.
    Stockholm University, Faculty of Science, Department of Physics.
    Morteau, E.
    Murra, M.
    Naganoma, J.
    Newstead, J. L.
    Ni, K.
    Oberlack, U.
    Pakarha, P.
    Pelssers, Bart
    Stockholm University, Faculty of Science, Department of Physics.
    de Perio, P.
    Persiani, R.
    Piastra, F.
    Piro, M. C.
    Plante, G.
    Rauch, L.
    Reichard, S.
    Rizzo, A.
    Rupp, N.
    Dos Santos, J. M. F.
    Sartorelli, G.
    Scheibelhut, M.
    Schindler, S.
    Schumann, M.
    Schreiner, J.
    Lavina, L. Scotto
    Selvi, M.
    Shagin, P.
    Silva, M. C.
    Simgen, H.
    Sissol, P.
    von Sivers, M.
    Thers, D.
    Thum, J.
    Tiseni, A.
    Trotta, R.
    Tunnell, C. D.
    Valerius, K.
    Vargas, M. A.
    Wang, H.
    Wei, Y.
    Weinheimer, C.
    Wester, T.
    Wulf, J.
    Zhang, Y.
    Zhu, T.
    Zuber, K.
    DARWIN: towards the ultimate dark matter detector2016In: Journal of Cosmology and Astroparticle Physics, ISSN 1475-7516, E-ISSN 1475-7516, no 11, article id 017Article in journal (Refereed)
    Abstract [en]

    DARk matter WImp search with liquid xenoN (DARWIN(2)) will be an experiment for the direct detection of dark matter using a multi-ton liquid xenon time projection chamber at its core. Its primary goal will be to explore the experimentally accessible parameter space for Weakly Interacting Massive Particles (WIMPs) in a wide mass-range, until neutrino interactions with the target become an irreducible background. The prompt scintillation light and the charge signals induced by particle interactions in the xenon will be observed by VUV sensitive, ultra-low background photosensors. Besides its excellent sensitivity to WIMPs above a mass of 5 GeV/c(2), such a detector with its large mass, low-energy threshold and ultra-low background level will also be sensitive to other rare interactions. It will search for solar axions,galactic axion-like particles and the neutrinoless double-beta decay of Xe-136, as well as measure the low-energy solar neutrino flux with <1% precision, observe coherent neutrino-nucleus interactions, and detect galactic supernovae. We present the concept of the DARWIN detector and discuss its physics reach, the main sources of backgrounds and the ongoing detector design and R&D efforts.

  • 6. Aartsen, M. G.
    et al.
    Ackermann, M.
    Adams, J.
    Aguilar, J. A.
    Ahlers, M.
    Ahrens, Maryon
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Altmann, D.
    Anderson, T.
    Arguelles, C.
    Arlen, T. C.
    Auffenberg, J.
    Bai, X.
    Barwick, S. W.
    Baum, V.
    Bay, R.
    Beatty, J. J.
    Tjus, J. Becker
    Becker, K. -H
    BenZvi, S.
    Berghaus, P.
    Berley, D.
    Bernardini, E.
    Bernhard, A.
    Besson, D. Z.
    Binder, G.
    Bindig, D.
    Bissok, M.
    Blaufuss, E.
    Blumenthal, J.
    Boersma, D. J.
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    Bos, F.
    Bose, D.
    Boeser, S.
    Botner, O.
    Brayeur, L.
    Bretz, H. -P
    Brown, A. M.
    Brunner, J.
    Buzinsky, N.
    Casey, J.
    Casier, M.
    Cheung, E.
    Chirkin, D.
    Christov, A.
    Christy, B.
    Clark, K.
    Classen, L.
    Clevermann, F.
    Coenders, S.
    Cowen, D. F.
    Silva, A. H. Cruz
    Daughhetee, J.
    Davis, J. C.
    Day, M.
    de Andre, J. P. A. M.
    De Clercq, C.
    De Ridder, S.
    Desiati, P.
    de Vries, K. D.
    de With, M.
    De Young, T.
    Diaz-Velez, J. C.
    Dunkman, M.
    Eagan, R.
    Eberhardt, B.
    Eichmann, B.
    Eisch, J.
    Euler, S.
    Evenson, P. A.
    Fadiran, O.
    Fazely, A. R.
    Fedynitch, A.
    Feintzeig, J.
    Felde, J.
    Feusels, T.
    Filimonov, K.
    Finley, Chad
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Fischer-Wasels, T.
    Flis, Samuel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Franckowiak, A.
    Frantzen, K.
    Fuchs, T.
    Gaisser, T. K.
    Gaior, R.
    Gallagher, J.
    Gerhardt, L.
    Gier, D.
    Gladstone, L.
    Gluesenkamp, T.
    Goldschmidt, A.
    Golup, G.
    Gonzalez, J. G.
    Goodman, J. A.
    Gora, D.
    Grant, D.
    Gretskov, P.
    Groh, J. C.
    Gross, A.
    Ha, C.
    Haack, C.
    Ismail, A. Haj
    Hallen, P.
    Hallgren, A.
    Halzen, F.
    Hanson, K.
    Hebecker, D.
    Heereman, D.
    Heinen, D.
    Helbing, K.
    Hellauer, R.
    Hellwig, D.
    Hickford, S.
    Hill, G. C.
    Hoffman, K. D.
    Hoffmann, R.
    Homeier, A.
    Hoshina, K.
    Huang, F.
    Huelsnitz, W.
    Hulth, Per Olof
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hultqvist, Klas
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hussain, S.
    Ishihara, A.
    Jacobi, E.
    Jacobsen, J.
    Jagielski, K.
    Japaridze, G. S.
    Jero, K.
    Jlelati, O.
    Jurkovic, M.
    Kaminsky, B.
    Kappes, A.
    Karg, T.
    Karle, A.
    Kauer, M.
    Keivani, A.
    Kelley, J. L.
    Kheirandish, A.
    Kiryluk, J.
    Klaes, J.
    Klein, S. R.
    Koehne, J. -H
    Kohnen, G.
    Kolanoski, H.
    Koob, A.
    Koepke, L.
    Kopper, C.
    Kopper, S.
    Koskinen, D. J.
    Kowalski, M.
    Kriesten, A.
    Krings, K.
    Kroll, G.
    Kroll, M.
    Kunnen, J.
    Kurahashi, N.
    Kuwabara, T.
    Labare, M.
    Lanfranchi, J. L.
    Larsen, D. T.
    Larson, M. J.
    Lesiak-Bzdak, M.
    Leuermann, M.
    Luenemann, J.
    Madsen, J.
    Maggi, G.
    Maruyama, R.
    Mase, K.
    Matis, H. S.
    Maunu, R.
    McNally, F.
    Meagher, K.
    Medici, M.
    Meli, A.
    Meures, T.
    Miarecki, S.
    Middell, E.
    Middlemas, E.
    Milke, N.
    Miller, J.
    Mohrmann, L.
    Montaruli, T.
    Morse, R.
    Nahnhauer, R.
    Naumann, U.
    Niederhausen, H.
    Nowicki, S. C.
    Nygren, D. R.
    Obertacke, A.
    Odrowski, S.
    Olivas, A.
    Omairat, A.
    O'Murchadha, A.
    Palczewski, T.
    Paul, L.
    Penek, Oe.
    Pepper, J. A.
    de los Heros, C. Perez
    Pfendner, C.
    Pieloth, D.
    Pinat, E.
    Posselt, J.
    Price, P. B.
    Przybylski, G. T.
    Puetz, J.
    Quinnan, M.
    Raedel, L.
    Rameez, M.
    Rawlins, K.
    Redl, P.
    Rees, I.
    Reimann, R.
    Relich, M.
    Resconi, E.
    Rhode, W.
    Richman, M.
    Riedel, B.
    Robertson, S.
    Rodrigues, J. P.
    Rongen, M.
    Rott, C.
    Ruhe, T.
    Ruzybayev, B.
    Ryckbosch, D.
    Saba, S. M.
    Sander, H. -G
    Sandroos, J.
    Santander, M.
    Sarkar, S.
    Schatto, K.
    Scheriau, F.
    Schmidt, T.
    Schmitz, M.
    Schoenen, S.
    Schoeneberg, S.
    Schoenwald, A.
    Schukraft, A.
    Schulte, L.
    Schulz, O.
    Seckel, D.
    Sestayo, Y.
    Seunarine, S.
    Shanidze, R.
    Smith, M. W. E.
    Soldin, D.
    Spiczak, G. M.
    Spiering, C.
    Stamatikos, M.
    Stanev, T.
    Stanisha, N. A.
    Stasik, A.
    Stezelberger, T.
    Stokstad, R. G.
    Stoessl, A.
    Strahler, E. A.
    Strom, R.
    Strotjohann, N. L.
    Sullivan, G. W.
    Taavola, H.
    Taboada, I.
    Tamburro, A.
    Tepe, A.
    Ter-Antonyan, S.
    Terliuk, A.
    Tesic, G.
    Tilav, S.
    Toale, P. A.
    Tobin, M. N.
    Tosi, D.
    Tselengidou, M.
    Unger, E.
    Usner, M.
    Vallecorsa, S.
    van Eijndhoven, N.
    Vandenbroucke, J.
    van Santen, J.
    Vehring, M.
    Voge, M.
    Vraeghe, M.
    Walck, Christian
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Wallraff, M.
    Weaver, Ch.
    Wellons, M.
    Wendt, C.
    Westerhoff, S.
    Whelan, B. J.
    Whitehorn, N.
    Wichary, C.
    Wiebe, K.
    Wiebusch, C. H.
    Williams, D. R.
    Wissing, H.
    Wolf, Martin
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Wood, T. R.
    Woschnagg, K.
    Xu, D. L.
    Xu, X. W.
    Yanez, J. P.
    Yodh, G.
    Yoshida, S.
    Zarzhitsky, P.
    Ziemann, J.
    Zierke, S.
    Zoll, Marcel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Determining neutrino oscillation parameters from atmospheric muon neutrino disappearance with three years of IceCube DeepCore data2015In: Physical Review D, ISSN 1550-7998, E-ISSN 1550-2368, Vol. 91, no 7, article id 072004Article in journal (Refereed)
    Abstract [en]

    We present a measurement of neutrino oscillations via atmospheric muon neutrino disappearance with three years of data of the completed IceCube neutrino detector. DeepCore, a region of denser IceCube instrumentation, enables the detection and reconstruction of atmospheric muon neutrinos between 10 and 100 GeV, where a strong disappearance signal is expected. The IceCube detector volume surrounding DeepCore is used as a veto region to suppress the atmospheric muon background. Neutrino events are selected where the detected Cherenkov photons of the secondary particles minimally scatter, and the neutrino energy and arrival direction are reconstructed. Both variables are used to obtain the neutrino oscillation parameters from the data, with the best fit given by Delta m(32)(2) = 2.72(-0.20)(+0.19) x 10(-3) eV(2) and sin(2)theta(23) = 0.53(-0.12)(+0.09) (normal mass ordering assumed). The results are compatible, and comparable in precision, to those of dedicated oscillation experiments.

  • 7. Aartsen, M. G.
    et al.
    Ackermann, M.
    Adams, J.
    Aguilar, J. A.
    Ahlers, M.
    Ahrens, Maryon
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Altmann, D.
    Anderson, T.
    Arguelles, C.
    Arlen, T. C.
    Auffenberg, J.
    Bai, X.
    Barwick, S. W.
    Baum, V.
    Beatty, J. J.
    Tjus, J. Becker
    Becker, K. -H
    BenZvi, S.
    Berghaus, P.
    Berley, D.
    Bernardini, E.
    Bernhard, A.
    Besson, D. Z.
    Binder, G.
    Bindig, D.
    Bissok, M.
    Blaufuss, E.
    Blumenthal, J.
    Boersma, D. J.
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    Bos, F.
    Bose, D.
    Boeser, S.
    Botner, O.
    Brayeur, L.
    Bretz, H. -P
    Brown, A. M.
    Casey, J.
    Casier, M.
    Cheung, E.
    Chirkin, D.
    Christov, A.
    Christy, B.
    Clark, K.
    Classen, L.
    Cleverinann, F.
    Coenders, S.
    Cowen, D. F.
    Silva, A. H. Cruz
    Danninger, Matthias
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Daughhetee, J.
    Davis, J. C.
    Day, M.
    de Andre, J. P. A. M.
    De Clercq, C.
    De Ridder, S.
    Desiati, P.
    de Vries, K. D.
    de With, M.
    DeYoung, T.
    Diaz-Velez, J. C.
    Dunkman, M.
    Eagan, R.
    Eberhardt, B.
    Eichmann, B.
    Eisch, J.
    Euler, S.
    Evenson, P. A.
    Fadiran, O.
    Fazely, A. R.
    Fedynitch, A.
    Feintzeig, J.
    Felde, J.
    Feusels, T.
    Filimonov, K.
    Finley, Chad
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Fischer-Wasels, T.
    Flis, Samuel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Franckowiak, A.
    Frantzen, K.
    Fuchs, T.
    Gaisser, T. K.
    Gaior, R.
    Gallagher, J.
    Gerhardt, L.
    Gier, D.
    Gladstone, L.
    Gluesenkamp, T.
    Goldschmidt, A.
    Golup, G.
    Gonzalez, J. G.
    Goodman, J. A.
    Gora, D.
    Grant, D.
    Gretskov, P.
    Groh, J. C.
    Gross, A.
    Ha, C.
    Haack, C.
    Ismail, A. Haj
    Hallen, P.
    Hallgren, A.
    Halzen, F.
    Hanson, K.
    Hebecker, D.
    Heereman, D.
    Heinen, D.
    Helbing, K.
    Hellauer, R.
    Hellwig, D.
    Hickford, S.
    Hill, G. C.
    Hoffman, K. D.
    Hoffmann, R.
    Homeier, A.
    Hoshina, K.
    Huang, F.
    Huelsnitz, W.
    Hulth, Per Olof
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hultqvist, Klas
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hussain, S.
    Ishihara, A.
    Jacobi, E.
    Jacobsen, J.
    Jagielski, K.
    Japaridze, G. S.
    Jero, K.
    Jlelati, O.
    Jurkovic, M.
    Kaminsky, B.
    Kappes, A.
    Karg, T.
    Karle, A.
    Kauer, M.
    Kelley, J. L.
    Kheirandish, A.
    Kiryluk, J.
    Klaes, J.
    Klein, S. R.
    Koehne, J. -H
    Kohnen, G.
    Kolanoski, H.
    Koob, A.
    Koepke, L.
    Kopper, C.
    Kopper, S.
    Koskinen, D. J.
    Kowalski, M.
    Kriesten, A.
    Krings, K.
    Kroll, G.
    Kroll, M.
    Kunnen, J.
    Kurahashi, N.
    Kuwabara, T.
    Labare, M.
    Larsen, D. T.
    Larson, M. J.
    Lesiak-Bzdak, M.
    Leuermann, M.
    Leute, J.
    Luenemann, J.
    Madsen, J.
    Maggi, G.
    Maruyama, R.
    Mase, K.
    Matis, H. S.
    Maunu, R.
    McNally, F.
    Meagher, K.
    Medici, M.
    Meli, A.
    Meures, T.
    Miarecki, S.
    Middell, E.
    Middlemas, E.
    Milke, N.
    Miller, J.
    Mohrmann, L.
    Montaruli, T.
    Morse, R.
    Nahnhauer, R.
    Naumann, U.
    Niederhausen, H.
    Nowicki, S. C.
    Nygren, D. R.
    Obertacke, A.
    Odrowski, S.
    Olivas, A.
    Omairat, A.
    O'Murchadha, A.
    Palczewski, T.
    Paul, L.
    Penek, Oe.
    Pepper, J. A.
    de los Heros, C. Perez
    Pfendner, C.
    Pieloth, D.
    Pinat, E.
    Posselt, J.
    Price, P. B.
    Przybylski, G. T.
    Puetz, J.
    Quinnan, M.
    Raedel, L.
    Rameez, M.
    Rawlins, K.
    Redl, P.
    Rees, I.
    Reimann, R.
    Relich, M.
    Resconi, E.
    Rhode, W.
    Richman, M.
    Riedel, B.
    Robertson, S.
    Rodrigues, Jp.
    Rongen, M.
    Rott, C.
    Ruhe, T.
    Ruzybayev, B.
    Ryckbosch, D.
    Saba, S. M.
    Sander, H. -G
    Sandroos, J.
    Santander, M.
    Sarkar, S.
    Schatto, K.
    Scheriau, F.
    Schmidt, T.
    Schmitz, M.
    Schoenen, S.
    Schoeneberg, S.
    Schoenwald, A.
    Schukraft, A.
    Schulte, L.
    Schulz, O.
    Seckel, D.
    Sestayo, Y.
    Seunarine, S.
    Shanidze, R.
    Smith, M. W. E.
    Soldin, D.
    Spiczak, G. M.
    Spiering, C.
    Stamatikos, M.
    Stanev, T.
    Stanisha, N. A.
    Stasik, A.
    Stezelberger, T.
    Stokstad, R. G.
    Stoessl, A.
    Strahler, E. A.
    Stroem, R.
    Strotjohann, N. L.
    Sullivan, G. W.
    Taavola, H.
    Taboada, I.
    Tamburro, A.
    Tepe, A.
    Ter-Antonyan, S.
    Terliuk, A.
    Tesic, G.
    Tilav, S.
    Toale, P. A.
    Tobin, M. N.
    Tosi, D.
    Tselengidou, M.
    Unger, E.
    Usner, M.
    Vallecorsa, S.
    van Eijndhoven, N.
    Vandenbroucke, J.
    van Santen, J.
    Vehring, M.
    Voge, M.
    Vraeghe, M.
    Walck, Christian
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Wallraff, M.
    Weaver, Ch.
    Wellons, M.
    Wendt, C.
    Westerhoff, S.
    Whelan, B. J.
    Whitehorn, N.
    Wichary, C.
    Wiebe, K.
    Wiebusch, C. H.
    Williams, D. R.
    Wissing, H.
    Wolf, Martin
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Wood, T. R.
    Woschnagg, K.
    Xu, D. L.
    Xu, X. W.
    Yanez, J. P.
    Yodh, G.
    Yoshida, S.
    Zarzhitsky, P.
    Ziemann, J.
    Zierke, S.
    Zoll, Marcel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Searches for small-scale anisotropies from neutrino point sources with three years of IceCube data2015In: Astroparticle physics, ISSN 0927-6505, E-ISSN 1873-2852, Vol. 66, p. 39-52Article in journal (Refereed)
    Abstract [en]

    Recently, IceCube found evidence for a diffuse signal of astrophysical neutrinos in an energy range of similar to 60 TeV to the PeV-scale [1]. The origin of those events, being a key to understanding the origin of cosmic rays, is still an unsolved question. So far, analyses have not succeeded to resolve the diffuse signal into point-like sources. Searches including a maximum-likelihood-ratio test, based on the reconstructed directions and energies of the detected down- and up-going neutrino candidates, were also performed on IceCube data leading to the exclusion of bright point sources. In this paper, we present two methods to search for faint neutrino point sources in three years of IceCube data, taken between 2008 and 2011. The first method is an autocorrelation test, applied separately to the northern and southern sky. The second method is a multipole analysis, which expands the measured data in the northern hemisphere into spherical harmonics and uses the resulting expansion coefficients to separate signal from background. With both methods, the results are consistent with the background expectation with a slightly more sparse spatial distribution, corresponding to an underfluctuation. Depending on the assumed number of sources, the resulting upper limit on the flux per source in the northern hemisphere for an E-2 energy spectrum ranges from similar to 1.5. 10(-8) GeV/cm(2) s(-1), in the case of one assumed source, to similar to 4. 10(-10) GeV/cm(2) s(-1), in the case of 3500 assumed sources.

  • 8. Abazov, V. M.
    et al.
    Abbott, B.
    Abolins, M.
    Åsman, Barbro
    Stockholm University, Faculty of Science, Department of Physics.
    Search for Events with Leptonic Jets and Missing Transverse Energy in p(p)over-bar Collisions at root s=1.96 TeV2010In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 105, no 21, p. 211802-Article in journal (Refereed)
    Abstract [en]

    We present the first search for pair production of isolated jets of charged leptons in association with a large imbalance in transverse energy in pp̅ collisions using 5.8  fb-1 of integrated luminosity collected by the D0 detector at the Fermilab Tevatron Collider. No excess is observed above the standard model background, and the result is used to set upper limits on the production cross section of pairs of supersymmetric chargino and neutralino particles as a function of “dark-photon” mass, where the dark photon is produced in the decay of the lightest supersymmetric particle

  • 9. Abazov, V. M.
    et al.
    Abbott, B.
    Abolins, M.
    Åsman, Barbro
    Stockholm University, Faculty of Science, Department of Physics.
    Search for Sneutrino Production in e mu Final States in 5.3 fb(-1) of p(p)over-bar Collisions at root s = 1.96 TeV2010In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 105, no 19, p. 191802-Article in journal (Refereed)
    Abstract [en]

    We report the results of a search for R parity violating (RPV) interactions leading to the production of supersymmetric sneutrinos decaying into eμ final states using 5.3  fb-1 of integrated luminosity collected by the D0 experiment at the Fermilab Tevatron Collider. Having observed no evidence for production of eμ resonances, we set direct bounds on the RPV couplings λ311 and λ312 as a function of sneutrino mass.

  • 10. Abdalla, H.
    et al.
    Abramowski, A.
    Aharonian, F.
    Benkhali, F. Ait
    Akhperjanian, A. G.
    Andersson, T.
    Angüner, E. O.
    Arrieta, M.
    Aubert, P.
    Backes, M.
    Balzer, A.
    Barnard, M.
    Becherini, Y.
    Tjus, J. Becker
    Berge, D.
    Bernhard, S.
    Bernlöhr, K.
    Birsin, E.
    Blackwell, R.
    Böttcher, M.
    Boisson, C.
    Bolmont, J.
    Bordas, P.
    Bregeon, J.
    Brun, F.
    Brun, P.
    Bryan, M.
    Bulik, T.
    Capasso, M.
    Carr, J.
    Casanova, S.
    Chakraborty, N.
    Chalme-Calvet, R.
    Chaves, R. C. G.
    Chen, A.
    Chevalier, J.
    Chrétien, M.
    Colafrancesco, S.
    Cologna, G.
    Condon, B.
    Conrad, Jan
    Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC). Stockholm University, Faculty of Science, Department of Physics.
    Couturier, C.
    Cui, Y.
    Davids, I. D.
    Degrange, B.
    Deil, C.
    Devin, J.
    de Wilt, P.
    Djannati-Ataie, A.
    Domainko, W.
    Donath, A.
    Drury, L. O'C.
    Dubus, G.
    Dutson, K.
    Dyks, J.
    Dyrda, M.
    Edwards, T.
    Egberts, K.
    Eger, P.
    Ernenwein, J. -P.
    Eschbach, S.
    Farnier, Christian
    Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC). Stockholm University, Faculty of Science, Department of Physics.
    Fegan, S.
    Fernandes, M. V.
    Fiasson, A.
    Fontaine, G.
    Förster, A.
    Funk, S.
    Füssling, M.
    Gabici, S.
    Gajdus, M.
    Gallant, Y. A.
    Garrigoux, T.
    Giavitto, G.
    Giebels, B.
    Glicenstein, J. F.
    Gottschall, D.
    Goyal, A.
    Grondin, M. -H.
    Grudzinska, M.
    Hadasch, D.
    Hahn, J.
    Hawkes, J.
    Heinzelmann, G.
    Henri, G.
    Hermann, G.
    Hervet, O.
    Hillert, A.
    Hinton, J. A.
    Hofmann, W.
    Hoischen, C.
    Holler, M.
    Horns, D.
    Ivascenko, A.
    Jacholkowska, A.
    Jamrozy, M.
    Janiak, M.
    Jankowsky, D.
    Jankowsky, F.
    Jingo, M.
    Jogler, T.
    Jouvin, L.
    Jung-Richardt, I.
    Kastendieck, M. A.
    Katarzynski, K.
    Katz, U.
    Kerszberg, D.
    Khélifi, B.
    Kieffer, M.
    King, J.
    Klepser, S.
    Klochkov, D.
    Kluzniak, W.
    Kolitzus, D.
    Komin, Nu.
    Kosack, K.
    Krakau, S.
    Kraus, M.
    Krayzel, F.
    Krüger, P. P.
    Laffon, H.
    Lamanna, G.
    Lau, J.
    Lees, J. -P.
    Lefaucheur, J.
    Lefranc, V.
    Lemière, A.
    Lemoine-Goumard, M.
    Lenain, J. -P.
    Leser, E.
    Liu, R.
    Lohse, T.
    Lorentz, M.
    Lypova, I.
    Marandon, V.
    Marcowith, A.
    Mariaud, C.
    Marx, R.
    Maurin, G.
    Maxted, N.
    Mayer, M.
    Meintjes, P. J.
    Meyer, Manuel
    Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC). Stockholm University, Faculty of Science, Department of Physics.
    Mitchell, A. M. W.
    Moderski, R.
    Mohamed, M.
    Morå, Knut
    Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC). Stockholm University, Faculty of Science, Department of Physics.
    Moulin, E.
    Murach, T.
    de Naurois, M.
    Niederwanger, F.
    Niemiec, J.
    Oakes, L.
    O'Brien, P.
    Odaka, H.
    Ohm, S.
    Ostrowski, M.
    Öttl, S.
    Oya, I.
    Padovani, M.
    Panter, M.
    Parsons, R. D.
    Arribas, M. Paz
    Pekeur, N. W.
    Pelletier, G.
    Perennes, C.
    Petrucci, P. -O.
    Peyaud, B.
    Pita, S.
    Poon, H.
    Prokhorov, D.
    Prokoph, H.
    Pühlhofer, G.
    Punch, M.
    Quirrenbach, A.
    Raab, S.
    Reimer, A.
    Reimer, O.
    Renaud, M.
    Reyes, R. de los
    Rieger, F.
    Romoli, C.
    Rosier-Lees, S.
    Rowell, G.
    Rudak, B.
    Rulten, C. B.
    Sahakian, V.
    Salek, D.
    Sanchez, D. A.
    Santangelo, A.
    Sasaki, M.
    Schlickeiser, R.
    Schüssler, F.
    Schulz, A.
    Schwanke, U.
    Schwemmer, S.
    Settimo, M.
    Seyffert, A. S.
    Shafi, N.
    Shilon, I.
    Simoni, R.
    Sol, H.
    Spanier, F.
    Spengler, Gerrit
    Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC). Stockholm University, Faculty of Science, Department of Physics.
    Spies, F.
    Stawarz, L.
    Steenkamp, R.
    Stegmann, C.
    Stinzing, F.
    Stycz, K.
    Sushch, I.
    Tavernet, J. -P.
    Tavernier, T.
    Taylor, A. M.
    Terrier, R.
    Tibaldo, L.
    Tluczykont, M.
    Trichard, C.
    Tuffs, R.
    van der Walt, J.
    van Eldik, C.
    van Soelen, B.
    Vasileiadis, G.
    Veh, J.
    Venter, C.
    Viana, A.
    Vincent, P.
    Vink, J.
    Voisin, F.
    Völk, H. J.
    Vuillaume, T.
    Wadiasingh, Z.
    Wagner, S. J.
    Wagner, P.
    Wagner, Roger M.
    Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC). Stockholm University, Faculty of Science, Department of Physics.
    White, R.
    Wierzcholska, A.
    Willmann, P.
    Wörnlein, A.
    Wouters, D.
    Yang, R.
    Zabalza, V.
    Zaborov, D.
    Zacharias, M.
    Zdziarski, A. A.
    Zech, A.
    Zefi, F.
    Ziegler, A.
    Zywucka, N.
    HESS Limits on Linelike Dark Matter Signatures in the 100 GeV to 2 TeV Energy Range Close to the Galactic Center2016In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 117, no 15, article id 151302Article in journal (Refereed)
    Abstract [en]

    A search for dark matter linelike signals iss performed in the vicinity of the Galactic Center by the H.E.S.S. experiment on observational data taken in 2014. An unbinned likelihood analysis iss developed to improve the sensitivity to linelike signals. The upgraded analysis along with newer data extend the energy coverage of the previous measurement down to 100 GeV. The 18 h of data collected with the H.E.S.S. array allow one to rule out at 95% C.L. the presence of a 130 GeV line (at l = -1.5 degrees, b = 0 degrees and for a dark matter profile centered at this location) previously reported in Fermi-LAT data. This new analysis overlaps significantly in energy with previous Fermi-LAT and H.E.S.S. results. No significant excess associated with dark matter annihilations was found in the energy range of 100 GeV to 2 TeV and upper limits on the gamma-ray flux and the velocity weighted annihilation cross section are derived adopting an Einasto dark matter halo profile. Expected limits for present and future large statistics H.E.S.S. observations are also given.

  • 11. Abdalla, H.
    et al.
    Abramowski, A.
    Aharonian, F.
    Benkhali, F. Ait
    Akhperjanian, A. G.
    Anguenee, E. O.
    Arrieta, M.
    Aubert, P.
    Backes, M.
    Balzer, A.
    Barnard, M.
    Becherini, Y.
    Tjus, J. Becker
    Berge, D.
    Bernhard, S.
    Bernloehr, K.
    Birsin, E.
    Blackwell, R.
    Boettcher, M.
    Boisson, C.
    Bolmont, J.
    Bordas, P.
    Bregeon, J.
    Brun, F.
    Brun, P.
    Bryan, M.
    Bulik, T.
    Capasso, M.
    Carr, J.
    Casanova, S.
    Chadwick, P. M.
    Chakraborty, N.
    Chalme-Calvet, R.
    Chaves, R. C. G.
    Chen, A.
    Chevalier, J.
    Chretien, M.
    Colafrancesco, S.
    Cologna, G.
    Condon, B.
    Conrad, Jan M.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Couturier, C.
    Cui, Y.
    Davids, I. D.
    Degrange, B.
    Deil, C.
    deWilt, P.
    Dickinson, H. J.
    Djannati-Atai, A.
    Domainko, W.
    Donath, A.
    Drury, L. O'C.
    Dubus, G.
    Dutson, K.
    Dyks, J.
    Dyrda, M.
    Edwards, T.
    Egberts, K.
    Eger, P.
    Ernenwein, J. -P.
    Eschbach, S.
    Farnier, C.
    Fegan, S.
    Fernandes, M. V.
    Fiasson, A.
    Fontaine, G.
    Foerster, A.
    Funk, S.
    Fuessling, M.
    Gabici, S.
    Gajdus, M.
    Gallant, Y. A.
    Garrigoux, T.
    Giavitto, G.
    Giebels, B.
    Glicenstein, J. F.
    Gottschall, D.
    Goya, A.
    Grondin, M. -H.
    Grudzinska, M.
    Hadasch, D.
    Hahn, J.
    Hawkes, J.
    Heinzelmann, G.
    Henri, G.
    Hermann, G.
    Hervet, O.
    Hillert, A.
    Hinton, J. A.
    Hofmann, W.
    Hoischen, C.
    Holler, M.
    Horns, D.
    Ivascenko, A.
    Jacholkowska, A.
    Jamrozy, M.
    Janiak, M.
    Jankowsky, D.
    Jankowsky, F.
    Jingo, M.
    Jogler, T.
    Jouvin, L.
    Jung-Richardt, I.
    Kastendieck, M. A.
    Katarzynski, K.
    Katz, U.
    Kerszberg, D.
    Khelifi, B.
    Kieffer, M.
    King, J.
    Klepser, S.
    Klochkov, D.
    Kluzniak, W.
    Kolitzus, D.
    Komin, Nu.
    Kosack, K.
    Krakau, S.
    Kraus, M.
    Krayzel, F.
    Krueger, P. P.
    Laffon, H.
    Lamanna, G.
    Lau, J.
    Lees, J. -P.
    Lefaucheur, J.
    Lefranc, V.
    Lemiere, A.
    Lemoine-Goumard, M.
    Lenain, J. -P.
    Leser, E.
    Lohse, T.
    Lorentz, M.
    Liu, R.
    Lypova, I.
    Marandon, V.
    Marcowith, A.
    Mariaud, C.
    Marx, R.
    Maurin, G.
    Maxted, N.
    Mayer, M.
    Meintjes, P. J.
    Menzler, U.
    Meyer, M.
    Mitchell, A. M. W.
    Moderski, R.
    Mohamed, M.
    Mora, K.
    Moulin, E.
    Murach, T.
    de Naurois, M.
    Niederwanger, F.
    Niemiec, J.
    Oakes, L.
    Odaka, H.
    Oettl, S.
    Ohm, S.
    Ostrowski, M.
    Oya, I.
    Padovani, M.
    Panter, M.
    Parsons, R. D.
    Arribas, M. Paz
    Pekeur, N. W.
    Pelletier, G.
    Petrucci, P. -O.
    Peyaud, B.
    Pita, S.
    Poona, H.
    Prokhorov, D.
    Prokoph, H.
    Puehlhofer, G.
    Punch, M.
    Quirrenbach, A.
    Raab, S.
    Reimer, A.
    Reimer, O.
    Renaud, M.
    de los Reyes, R.
    Rieger, F.
    Romoli, C.
    Rosier-Lees, S.
    Rowell, G.
    Rudak, B.
    Rulten, C. B.
    Sahakian, V.
    Salek, D.
    Sanchez, D. A.
    Santangelo, A.
    Sasaki, M.
    Schlickeiser, R.
    Schuessler, F.
    Schulz, A.
    Schwanke, U.
    Schwemmer, S.
    Seyffert, A. S.
    Shafi, N.
    Shilon, I.
    Simoni, R.
    Sol, H.
    Spanier, F.
    Spengler, G.
    Spies, F.
    Stawarz, L.
    Steenkamp, R.
    Stegmann, C.
    Stinzing, F.
    Stycz, K.
    Sushch, I.
    Tavernet, J. -P.
    Tavernier, T.
    Taylor, A. M.
    Terrier, R.
    Tluczykont, M.
    Trichard, C.
    Tuffs, R.
    van der Walt, J.
    van Eldik, C.
    van Soelen, B.
    Vasileiadis, G.
    Veh, J.
    Venters, C.
    Viana, A.
    Vincent, P.
    Vink, J.
    Voisin, F.
    Voelk, H. J.
    Vuillaume, T.
    Wadiasingh, Z.
    Wagner, S. J.
    Wagner, P.
    Wagner, R. M.
    White, R.
    Wierzcholska, A.
    Willmann, P.
    Woernlein, A.
    Wouters, D.
    Yang, R.
    Zabalza, V.
    Zaborov, D.
    Zacharias, M.
    Zdziarski, A. A.
    Zech, A.
    Zefi, F.
    Ziegler, A.
    Zywucka, N.
    A search for very high-energy flares from the microquasars GRS 1915+105, Circinus X-1, and V4641 Sgr using contemporaneous HESS and RXTE observations2018In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 612, article id A10Article in journal (Refereed)
    Abstract [en]

    Context. Microquasars are potential gamma-ray emitters. Indications of transient episodes of gamma-ray emission were recently reported in at least two systems: Cyg X-1 and Cyg X-3. The identification of additional gamma-ray-emitting microquasars is required to better understand how gamma-ray emission can be produced in these systems.

    Aims. Theoretical models have predicted very high-energy (VHE) gamma-ray emission from microquasars during periods of transient outburst. Observations reported herein were undertaken with the objective of observing a broadband flaring event in the gamma-ray and X-ray bands.

    Methods. Contemporaneous observations of three microquasars, GRS 1915+105, Circinus X-1, and V4641 Sgr, were obtained using the High Energy Spectroscopic System (H.E.S.S.) telescope array and the Rossi X-ray Timing Explorer (RXTE) satellite. X-ray analyses for each microquasar were performed and VHE gamma-ray upper limits from contemporaneous H.E.S.S. observations were derived.

    Results. No significant gamma-ray signal has been detected in any of the three systems. The integral gamma-ray photon flux at the observational epochs is constrained to be I(>560 GeV) < 7.3 x 10(-13) cm(-2) S-1, I(>560 GeV) < 1.2 x 10-(12) cm s(-1), and I(>240 GeV) < 4.5 x 10(-12) cm(-2) s(-1) for GRS 1915+105, Circinus X-1, and V4641 Sgr, respectively.

    Conclusions. The gamma-ray upper limits obtained using H.E.S.S. are examined in the context of previous Cherenkov telescope observations of microquasars. The effect of intrinsic absorption is modelled for each target and found to have negligible impact on the flux of escaping gamma-rays. When combined with the X-ray behaviour observed using RXTE, the derived results indicate that if detectable VHE gamma-ray emission from microquasars is commonplace, then it is likely to be highly transient.

  • 12. Abdalla, H.
    et al.
    Abramowski, A.
    Aharonian, F.
    Benkhali, F. Ait
    Akhperjanian, A. G.
    Anguener, E. O.
    Arrieta, M.
    Aubert, P.
    Backes, M.
    Balzer, A.
    Barnard, M.
    Becherini, Y.
    Tjus, J. Becker
    Berge, D.
    Bernhard, S.
    Bernloehr, K.
    Birsin, E.
    Blackwell, R.
    Bottcher, M.
    Boisson, C.
    Bolmont, J.
    Bordas, P.
    Bregeon, J.
    Brun, F.
    Brun, P.
    Bryan, M.
    Bulik, T.
    Capasso, M.
    Carr, J.
    Casanova, S.
    Chakraborty, N.
    Chalme-Calvet, R.
    Chaves, R. C. G.
    Chen, A.
    Chevalier, J.
    Chretien, M.
    Colafrancesco, S.
    Cologna, G.
    Condon, B.
    Conrad, J.
    Cui, Y.
    Davids, I. D.
    Degrange, B.
    Deil, C.
    deWilt, P.
    Djannati-Atai, A.
    Domainko, W.
    Donath, A.
    Drury, L. O'C.
    Dubus, G.
    Dutson, K.
    Dyks, J.
    Dyrda, M.
    Edwards, T.
    Egberts, K.
    Eger, P.
    Ernenwein, J. -P.
    Eschbach, S.
    Farnier, Christian
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC). Linnaeus University, Sweden.
    Fegan, S.
    Fernandes, M. V.
    Fiasson, A.
    Fontaine, G.
    Foerster, A.
    Funk, S.
    Fuessling, M.
    Gabici, S.
    Gajdus, M.
    Gallant, Y. A.
    Garrigoux, T.
    Giavitto, G.
    Giebels, B.
    Glicenstein, J. F.
    Gottschall, D.
    Goyal, A.
    Grondin, M. -H.
    Grudzinska, M.
    Hadasch, D.
    Hahn, J.
    Hawkes, J.
    Heinzelmann, G.
    Henri, G.
    Hermann, G.
    Hervet, O.
    Hillert, A.
    Hinton, J. A.
    Hofmann, W.
    Hoischen, C.
    Holler, M.
    Horns, D.
    Ivascenko, A.
    Jacholkowska, A.
    Jamrozy, M.
    Janiak, M.
    Jankowsky, D.
    Jankowsky, F.
    Jingo, M.
    Jogler, T.
    Jouvin, L.
    Jung-Richardt, I.
    Kastendieck, M. A.
    Katarzynski, K.
    Katz, U.
    Kerszberg, D.
    Khelifi, B.
    Kieffer, M.
    King, J.
    Klepser, S.
    Klochkov, D.
    Kluzniak, W.
    Kolitzus, D.
    Komin, Nu.
    Kosack, K.
    Krakau, S.
    Kraus, M.
    Krayzel, F.
    Kruger, P. P.
    Laffon, H.
    Lamanna, G.
    Lau, J.
    Lees, J. -P.
    Lefaucheur, J.
    Lefranc, V.
    Lemiere, A.
    Lemoine-Goumard, M.
    Lenain, J. -P.
    Leser, E.
    Lohse, T.
    Lorentz, M.
    Liu, R.
    Lypova, I.
    Marandon, V.
    Marcowith, A.
    Mariaud, C.
    Marx, R.
    Maurin, G.
    Maxted, N.
    Mayer, M.
    Meintjes, P. J.
    Menzler, U.
    Meyer, Manuel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Mitchell, A. M. W.
    Moderski, R.
    Mohamed, M.
    Morå, Knut
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Moulin, E.
    Murach, T.
    de Naurois, M.
    Niederwanger, F.
    Niemiec, J.
    Oakes, L.
    Odaka, H.
    Oettl, S.
    Ohm, S.
    Ostrowski, M.
    Oya, I.
    Padovani, M.
    Panter, M.
    Parsons, R. D.
    Arribas, M. Paz
    Pekeur, N. W.
    Pelletier, G.
    Petrucci, P. -O.
    Peyaud, B.
    Pita, S.
    Poon, H.
    Prokhorov, D.
    Prokoph, H.
    Puehlhofer, G.
    Punch, M.
    Quirrenbach, A.
    Raab, S.
    Reimer, A.
    Reimer, O.
    Renaud, M.
    de los Reyes, R.
    Rieger, F.
    Romoli, C.
    Rosier-Lees, S.
    Rowell, G.
    Rudak, B.
    Rulten, C. B.
    Sahakian, V.
    Salek, D.
    Sanchez, D. A.
    Santangelo, A.
    Sasaki, M.
    Schlickeiser, R.
    Schussler, F.
    Schulz, A.
    Schwanke, U.
    Schwemmer, S.
    Seyffert, A. S.
    Shafi, N.
    Shilon, I.
    Simoni, R.
    Sol, H.
    Spanier, F.
    Spengler, Gerrit
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Spies, F.
    Stawarz, L.
    Steenkamp, R.
    Stegmann, C.
    Stinzing, F.
    Stycz, K.
    Sushch, I.
    Tavernet, J. -P.
    Tavernier, T.
    Taylor, A. M.
    Terrier, R.
    Tluczykont, M.
    Trichard, C.
    Tuffs, R.
    van der Walt, J.
    van Eldik, C.
    van Soelen, B.
    Vasileiadis, G.
    Veh, J.
    Venter, C.
    Viana, A.
    Vincent, P.
    Vink, J.
    Voisin, F.
    Voelk, H. J.
    Vuillaume, T.
    Wadiasingh, Z.
    Wagner, S. J.
    Wagner, P.
    Wagner, Robert M.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    White, R.
    Wierzcholska, A.
    Willmann, P.
    Woernlein, A.
    Wouters, D.
    Yang, R.
    Zabalza, V.
    Zaborov, D.
    Zacharias, M.
    Zdziarski, A. A.
    Zech, A.
    Zefi, F.
    Ziegler, A.
    Zywucka, N.
    Extended VHE gamma-ray emission towards SGR1806-20, LBV 1806-20, and stellar cluster Cl*1806-202018In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 612, article id A11Article in journal (Refereed)
    Abstract [en]

    Using the High Energy Spectroscopic System (H.E.S.S.) telescopes we have discovered a steady and extended very high-energy (VHE) gamma-ray source towards the luminous blue variable candidate LBV 1806-20, massive stellar cluster Cl* 1806-20, and magnetar SGR 1806-20. The new VHE source, HESS J1808-204, was detected at a statistical significance of >6 sigma (post-trial) with a photon flux normalisation (2.9 +/- 0.4(stat) +/- 0.5(sys)) x 10(-13) ph cm(-2) s(-1) TeV-1 at 1 TeV and a power-law photon index of 2.3 +/- 0.2(stat) +/- 0.3(sys). The luminosity of this source (0.2 to 10 TeV; scaled to distance d = 8 : 7 kpc) is L-VHE similar to 1.6 x 10(34)(d = 8.7 kpc)(2) erg s(-1). The VHE gamma-ray emission is extended and is well fit by a single Gaussian with statistical standard deviation of 0.095 degrees +/- 0.015 degrees. This extension is similar to that of the synchrotron radio nebula G10.0-0.3, which is thought to be powered by LBV 1806-20. The VHE gamma-ray luminosity could be provided by the stellar wind luminosity of LBV 1806-20 by itself and/or the massive star members of Cl* 1806-20. Alternatively, magnetic dissipation (e.g. via reconnection) from SGR 1806-20 can potentially account for the VHE luminosity. The origin and hadronic and/or leptonic nature of the accelerated particles responsible for HESS J1808-204 is not yet clear. If associated with SGR 1806 20, the potentially young age of the magnetar (650 yr) can be used to infer the transport limits of these particles to match the VHE source size. This discovery provides new interest in the potential for high-energy particle acceleration from magnetars, massive stars, and/or stellar clusters.

  • 13. Abdalla, H.
    et al.
    Aharonian, F.
    Benkhali, F. Ait
    Anguner, E. O.
    Arakawa, M.
    Arcaro, C.
    Armand, C.
    Arrieta, M.
    Backes, M.
    Barnard, M.
    Becherini, Y.
    Tjus, J. Becker
    Berge, D.
    Bernhard, S.
    Bernloehr, K.
    Blackwell, R.
    Bottcher, M.
    Boisson, C.
    Bolmont, J.
    Bonnefoy, S.
    Bordas, P.
    Bregeon, J.
    Brun, F.
    Brun, P.
    Bryan, M.
    Buechele, M.
    Bulik, T.
    Bylund, T.
    Capasso, M.
    Caroff, S.
    Carosi, A.
    Casanova, S.
    Cerruti, M.
    Chakraborty, N.
    Chandra, S.
    Chaves, R. C. G.
    Chen, A.
    Colafrancesco, S.
    Condon, B.
    Davids, I. D.
    Dei, C.
    Devin, J.
    dewilt, P.
    Dirson, L.
    Djannati-Atai, A.
    Dmytriiev, A.
    Donath, A.
    Drury, L. O'C
    Dyks, J.
    Egberts, K.
    Emery, G.
    Ernenwein, J-P
    Eschbach, S.
    Fegan, S.
    Fiasson, A.
    Fontaine, G.
    Funk, S.
    Fuessling, M.
    Gabici, S.
    Gallant, Y. A.
    Garrigoux, T.
    Gate, F.
    Giavitto, G.
    Glawion, D.
    Glicenstein, J. F.
    Gottschall, D.
    Grondin, M-H
    Hahn, J.
    Haupt, M.
    Heinzelmann, G.
    Henri, G.
    Hermann, G.
    Hinton, J. A.
    Hofmann, W.
    Hoischen, C.
    Holch, T. L.
    Holler, M.
    Horns, D.
    Huber, D.
    Iwasaki, H.
    Jacholkowska, A.
    Jamrozy, M.
    Jankowsky, D.
    Jankowsky, F.
    Jouvin, L.
    Jung-Richardt, I
    Kastendieck, M. A.
    Katarzynski, K.
    Katsuragawa, M.
    Katz, U.
    Kerszberg, D.
    Khangulyan, D.
    Khelifi, B.
    King, J.
    Klepser, S.
    Kluzniak, W.
    Komin, Nu
    Kosack, K.
    Krakau, S.
    Kraus, M.
    Kruger, P. P.
    Lamanna, G.
    Lau, J.
    Lefaucheur, J.
    Lemiere, A.
    Lemoine-Goumard, M.
    Lenain, J-P
    Leser, E.
    Lohse, T.
    Lorentz, M.
    Lopez-Coto, R.
    Lypova, I
    Malyshev, D.
    Marandon, V
    Marcowith, A.
    Mariaud, C.
    Marti-Devesa, G.
    Marx, R.
    Maurin, G.
    Meintjes, P. J.
    Mitchell, A. M. W.
    Moderski, R.
    Mohamed, M.
    Mohrmann, L.
    Moulin, E.
    Murach, T.
    Nakashima, S.
    de Naurois, M.
    Ndiyavala, H.
    Niederwanger, F.
    Niemiec, J.
    Oakes, L.
    O'Brien, P.
    Odaka, H.
    Ohm, S.
    Ostrowski, M.
    Oya, I
    Padovani, M.
    Panter, M.
    Parsons, R. D.
    Perennes, C.
    Petrucci, P-O
    Peyaud, B.
    Piel, Q.
    Pita, S.
    Poireau, V
    Noel, A. Priyana
    Prokhorov, D. A.
    Prokoph, H.
    Puehlhofer, G.
    Punch, M.
    Quirrenbach, A.
    Raab, S.
    Rauth, R.
    Reimer, A.
    Reimer, O.
    Renaud, M.
    Rieger, F.
    Rinchiuso, L.
    Romoli, C.
    Rowel, G.
    Rudak, B.
    Ruiz-Velasco, E.
    Sahakian, V
    Saito, S.
    Sanchez, D. A.
    Santangelo, A.
    Sasaki, M.
    Schlickeiser, R.
    Schussler, F.
    Schulz, A.
    Schwanke, U.
    Schwemmer, S.
    Seglar-Arroyo, M.
    Senniappan, M.
    Seyffert, A. S.
    Shafi, N.
    Shilon, I
    Shiningayamwe, K.
    Simoni, R.
    Sinha, A.
    Sol, H.
    Spanier, F.
    Specovius, A.
    Spir-Jacob, M.
    Stawarz, L.
    Steenkamp, R.
    Stegmann, C.
    Steppa, C.
    Sushch, I
    Takahashi, T.
    Tavernet, J-P
    Tavernier, T.
    Taylor, A. M.
    Terrier, R.
    Tibaldo, L.
    Tiziani, D.
    Tluczykont, M.
    Trichard, C.
    Tsirou, M.
    Tsuji, N.
    Tuffs, R.
    Uchiyama, Y.
    van der Walt, D. J.
    van Eldik, C.
    van Rensburg, C.
    van Soelen, B.
    Vasileiadis, G.
    Veh, J.
    Venter, C.
    Viana, A.
    Vincent, P.
    Vink, J.
    Voisin, F.
    Voelk, H. J.
    Vuillaume, T.
    Wadiasingh, Z.
    Wagner, S. J.
    Wagner, P.
    Wagner, Robert M.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    White, R.
    Wierzcholska, A.
    Woernlein, A.
    Yang, R.
    Zaborov, D.
    Zacharias, M.
    Zanin, R.
    Zdziarski, A. A.
    Zech, A.
    Zefi, F.
    Ziegler, A.
    Zorn, J.
    Zywucka, N.
    The starburst galaxy NGC 253 revisited by HESS and Fermi-LAT2018In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 617, article id A73Article in journal (Refereed)
    Abstract [en]

    Context. NGC 253 is one of only two starburst galaxies found to emit gamma-rays from hundreds of MeV to multi-TeV energies. Accurate measurements of the very-high-energy (VHE; E> 100 GeV) and high-energy (HE; E > 60 MeV) spectra are crucial to study the underlying particle accelerators, probe the dominant emission mechanism(s) and to study cosmic-ray interaction and transport. Aims. The measurement of the VHE gamma-ray emission of NGC 253 published in 2012 by H.E.S.S. was limited by large systematic uncertainties. Here, the most up to date measurement of the gamma-ray spectrum of NGC 253 is investigated in both HE and VHE gamma-rays. Assuming a hadronic origin of the gamma-ray emission, the measurement uncertainties are propagated into the interpretation of the accelerated particle population. Methods. The data of H.E.S.S. observations are reanalysed using an updated calibration and analysis chain. The improved Fermi-LAT analysis employs more than 8 yr of data processed using pass 8. The cosmic-ray particle population is evaluated from the combined HE-VHE gamma-ray spectrum using NAIMA in the optically thin case. Results. The VHE gamma-ray energy spectrum is best fit by a power-law distribution with a flux normalisation of (1.34 +/- 0.14(stat) +/- 0.27(sys)) x 10(-13) cm(-2) s(-1) TeV-1 at 1 TeV - about 40% above, but compatible with the value obtained in Abramowski et al. (2012). The spectral index Gamma = 2.39 +/- 0.14(stat) +/- 0.25(sys) is slightly softer than but consistent with the previous measurement within systematic errors. In the Fermi energy range an integral flux of F(E > 60 MeV) = (1.56 +/- 0.28(stat) +/- 0.15(sys)) x 10(-8) cm(-2) s(-1) is obtained. At energies above similar to 3 GeV the HE spectrum is consistent with a power-law ranging into the VHE part of the spectrum measured by H.E.S.S. with an overall spectral index Gamma = 2.22 +/- 0.06(stat). Conclusions. Two scenarios for the starburst nucleus are tested, in which the gas in the starburst nucleus acts as either a thin or a thick target for hadronic cosmic rays accelerated by the individual sources in the nucleus. In these two models, the level to which NGC 253 acts as a calorimeter is estimated to a range of f(cal) = 0.1 to 1 while accounting for the measurement uncertainties. The presented spectrum is likely to remain the most accurate measurements until the Cherenkov Telescope Array (CTA) has collected a substantial set of data towards NGC 253.

  • 14. Abdalla, H.
    et al.
    Collaboration, H. E. S. S.
    Abramowski, A.
    Aharonian, F.
    Benkhali, F. Ait
    Anguner, E. O.
    Arakawa, M.
    Armand, C.
    Arrieta, M.
    Backes, M.
    Balzer, A.
    Barnard, M.
    Becherini, Y.
    Tjus, J. Becker
    Berge, D.
    Bernhard, S.
    Bernloehr, K.
    Blackwell, R.
    Bottcher, M.
    Boisson, C.
    Bolmont, J.
    Bonnefoy, S.
    Bordas, P.
    Bregeon, J.
    Brun, F.
    Brun, P.
    Bryan, M.
    Buechele, M.
    Bulik, T.
    Capasso, M.
    Caroff, S.
    Carosi, A.
    Casanova, S.
    Cerruti, M.
    Chakraborty, N.
    Chaves, R. C. G.
    Chen, A.
    Chevalier, J.
    Colafrancesco, S.
    Condon, B.
    Conrad, Jan
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Davids, I. D.
    Decock, J.
    Deil, C.
    Devin, J.
    deWilt, P.
    Dirson, L.
    Djannati-Atai, A.
    Donath, A.
    Drury, L. O' C.
    Dyks, J.
    Edwards, T.
    Egberts, K.
    Emery, G.
    Ernenwein, J. -P.
    Eschbach, S.
    Farnier, Christian
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC). Linnaeus University, Sweden.
    Fegan, S.
    Fernandes, M. V.
    Fiasson, A.
    Fontaine, G.
    Funk, S.
    Fuessling, M.
    Gabici, S.
    Gallant, Y. A.
    Garrigoux, T.
    Gate, F.
    Giavitto, G.
    Glawion, D.
    Glicenstein, J. F.
    Gottschall, D.
    Grondin, M. -H.
    Hahn, J.
    Haupt, M.
    Hawkes, J.
    Heinzelmann, G.
    Henri, G.
    Hermann, G.
    Hinton, J. A.
    Hofmann, W.
    Hoischen, C.
    Holch, T. L.
    Holler, M.
    Horns, D.
    Ivascenko, A.
    Iwasaki, H.
    Jacholkowska, A.
    Jamrozy, M.
    Jankowsky, D.
    Jankowsky, F.
    Jingo, M.
    Jouvin, L.
    Jung-Richardt, I.
    Kastendieck, M. A.
    Katarzynski, K.
    Katsuragawa, M.
    Katz, U.
    Kerszberg, D.
    Khangulyan, D.
    Khelifi, B.
    King, J.
    Klepser, S.
    Klochkov, D.
    Kluzniak, W.
    Komin, Nu.
    Kosack, K.
    Krakau, S.
    Kraus, M.
    Kruger, P. P.
    Laffon, H.
    Lamanna, G.
    Lau, J.
    Lefaucheur, J.
    Lemiere, A.
    Lemoine-Goumard, M.
    Lenain, J. -P.
    Leser, E.
    Lohse, T.
    Lorentz, M.
    Liu, R.
    Lopez-Coto, R.
    Lypova, I.
    Malyshev, D.
    Marandon, V.
    Marcowith, A.
    Mariaud, C.
    Marx, R.
    Maurin, G.
    Maxted, N.
    Mayer, M.
    Meintjes, P. J.
    Meyer, Manuel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Mitchell, A. M. W.
    Moderski, R.
    Mohamed, M.
    Mohrmann, L.
    Morå, Knut
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Moulin, E.
    Murach, T.
    Nakashima, S.
    de Naurois, M.
    Ndiyavala, H.
    Niederwanger, F.
    Niemiec, J.
    Oakes, L.
    O'Brien, P.
    Odaka, H.
    Ohm, S.
    Ostrowski, M.
    Oya, I.
    Padovani, M.
    Panter, M.
    Parsons, R. D.
    Pekeur, N. W.
    Pelletier, G.
    Perennes, C.
    Petrucci, P. -O.
    Peyaud, B.
    Piel, Q.
    Pita, S.
    Poireau, V.
    Prokhorov, D. A.
    Prokoph, H.
    Puehlhofer, G.
    Punch, M.
    Quirrenbach, A.
    Raab, S.
    Rauth, R.
    Reimer, A.
    Reimer, O.
    Renaud, M.
    de los Reyes, R.
    Rieger, F.
    Rinchiuso, L.
    Romoli, C.
    Rowell, G.
    Rudak, B.
    Rulten, C. B.
    Sahakian, V.
    Saito, S.
    Sanchez, D. A.
    Santangelo, A.
    Sasaki, M.
    Schlickeiser, R.
    Schussler, F.
    Schulz, A.
    Schwanke, U.
    Schwemmer, S.
    Seglar-Arroyo, M.
    Seyffert, A. S.
    Shafi, N.
    Shilon, I.
    Shiningayamwe, K.
    Simoni, R.
    Sol, H.
    Spanier, F.
    Spir-Jacob, M.
    Stawarz, L.
    Steenkamp, R.
    Stegmann, C.
    Steppa, C.
    Sushch, I.
    Takahashi, T.
    Tavernet, J. -P.
    Tavernier, T.
    Taylor, A. M.
    Terrier, R.
    Tibaldo, L.
    Tiziani, D.
    Tluczykont, M.
    Trichard, C.
    Tsirou, M.
    Tsuji, N.
    Tuffs, R.
    Uchiyama, Y.
    van der Walt, D. J.
    van Eldik, C.
    van Rensburg, C.
    van Soelen, B.
    Vasileiadis, G.
    Veh, J.
    Venter, C.
    Viana, A.
    Vincent, P.
    Vink, J.
    Voisin, F.
    Voelk, H. J.
    Vuillaume, T.
    Wadiasingh, Z.
    Wagner, S. J.
    Wagner, P.
    Wagner, Robert M.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    White, R.
    Wierzcholska, A.
    Willmann, P.
    Woernlein, A.
    Wouters, D.
    Yang, R.
    Zaborov, D.
    Zacharias, M.
    Zanin, R.
    Zdziarski, A. A.
    Zech, A.
    Zefi, F.
    Ziegler, A.
    Zorn, J.
    Zywucka, N.
    Detection of variable VHE gamma-ray emission from the extra-galactic gamma-ray binary LMC P32018In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 610, article id L17Article in journal (Refereed)
    Abstract [en]

    Context. Recently, the high-energy (HE, 0.1-100 GeV) gamma-ray emission from the object LMC P3 in the Large Magellanic Cloud (LMC) has been discovered to be modulated with a 10.3-day period, making it the first extra-galactic gamma-ray binary.

    Aims. This work aims at the detection of very-high-energy (VHE, >100 GeV) gamma-ray emission and the search for modulation of the VHE signal with the orbital period of the binary system.

    Methods. LMC P3 has been observed with the High Energy Stereoscopic System (H.E.S.S.); the acceptance-corrected exposure time is 100 h. The data set has been folded with the known orbital period of the system in order to test for variability of the emission.

    Results. VHE gamma-ray emission is detected with a statistical significance of 6.4 sigma. The data clearly show variability which is phase-locked to the orbital period of the system. Periodicity cannot be deduced from the H.E.S.S. data set alone. The orbit-averaged luminosity in the 1-10 TeV energy range is (1.4 +/- 0.2) x 10(35) erg s(-1). A luminosity of (5 +/- 1) x 10(35) erg s(-1) is reached during 20% of the orbit. HE and VHE gamma-ray emissions are anti-correlated. LMC P3 is the most luminous gamma-ray binary known so far.

  • 15. Abdalla, H.
    et al.
    Conrad, Jan M.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Farnier, Christian
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC). Linnaeus University, Sweden.
    Meyer, Manuel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Morå, Knut
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Wagner, Robert M.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Zywucka, N.
    HESS J1741-302: a hidden accelerator in the Galactic plane2018In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 612, article id A13Article in journal (Refereed)
    Abstract [en]

    The H.E.S.S. Collaboration has discovered a new very high energy (VHE, E > 0.1 TeV) gamma-ray source, HESS J1741-302, located in the Galactic plane. Despite several attempts to constrain its nature, no plausible counterpart has been found so far at X-ray and MeV/GeV gamma-ray energies, and the source remains unidentified. An analysis of 145-h of observations of HESS J1741-302 at VHEs has revealed a steady and relatively weak TeV source (similar to 1% of the Crab Nebula flux), with a spectral index of Gamma = 2.3 +/- 0.2(stat) +/- 0.2(sys), extending to energies up to 10 TeV without any clear signature of a cut-off. In a hadronic scenario, such a spectrum implies an object with particle acceleration up to energies of several hundred TeV. Contrary to most H.E.S.S. unidentified sources, the angular size of HESS J1741-302 is compatible with the H.E.S.S. point spread function at VHEs, with an extension constrained to be below 0.068 degrees at a 99% confidence level. The gamma-ray emission detected by H.E.S.S. can be explained both within a hadronic scenario, due to collisions of protons with energies of hundreds of TeV with dense molecular clouds, and in a leptonic scenario, as a relic pulsar wind nebula, possibly powered by the middle-aged (20 kyr) pulsar PSR B1737-30. A binary scenario, related to the compact radio source 1LC 358.266+0.038 found to be spatially coincident with the best fit position of HESS J1741-302, is also envisaged.

  • 16. Abdallah et al., DELPHI Collaboration: J
    et al.
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics.
    Investigation of Colour Reconnection in WW Events with the DELPHI detector at LEP-22007In: European Physical Journal C, ISSN 1434-6044, E-ISSN 1434-6052, Vol. 51, no 2, p. 249-269Article in journal (Refereed)
    Abstract [en]

    In the reaction e(+)e(-) -> WW -> (q(1) (q) over bar (2))(q(3)(q) over bar (4)) the usual hadronization models treat the colour singlets q(1)(q) over bar (2) and q(3)(q) over bar (4) coming from two W bosons independently. However, since the. nal state partons may coexist in space and time, cross-talk between the two evolving hadronic systems may be possible during fragmentation through soft gluon exchange. This e. ect is known as colour reconnection. In this article the results of the investigation of colour reconnection e. ects in fully hadronic decays of W pairs in DELPHI at LEP are presented. Two complementary analyses were performed, studying the particle. ow between jets and W mass estimators, with negligible correlation between them, and the results were combined and compared to models. In the framework of the SK-I model, the value for its. parameter most compatible with the data was found to be:

    (SK)-S-kappa-I = 2.2(-1.3) (+2.5)

    corresponding to the probability of reconnection P-reco to be in the range 0.31 < P-reco < 0.68 at 68% confidence level with its best value at 0.52.

  • 17. Abdallah et al., DELPHI Collaboration: J
    et al.
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics.
    Search for a Fourth Generation b-quark at LEP-II at sqrt(s)=196-209 GeV2007In: European Physical Journal C, ISSN 1434-6044, E-ISSN 1434-6052, Vol. 50, no 3, p. 507-518Article in journal (Refereed)
    Abstract [en]

    A search for the pair production of fourth generation b'-quarks was performed using data taken by the DELPHI detector at LEP-II. The analysed data were collected at centre-of-mass energies ranging from 196 to 209 GeV, corresponding to an integrated luminosity of 420 pb(-1). No evidence for a signal was found. Upper limits on BR(b'-> bZ) and BR(b'-> bZ) were obtained for b' masses ranging from 96 to 103 GeV/c(2) stop. These limits, together with the theoretical branching ratios predicted by a sequential four generations model, were used to constrain the value of R-CKM=vertical bar V-cb(') /V-tb'V-tb vertical bar there V-cb', V-tb' and V-tb are elements of the extended CKM matrix.

  • 18. Abdallah et al., DELPHI Collaboration: J
    et al.
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics.
    Study of Multi-Muon Bundles in Cosmic Ray Showers Detected with the DELPHI Detector at LEP2007In: Astroparticle physics, ISSN 0927-6505, E-ISSN 1873-2852, Vol. 28, no 3, p. 273-286Article in journal (Refereed)
    Abstract [en]

    The DELPHI detector at LEP has been used to measure multi-muon bundles originating from cosmic ray interactions with air. The cosmic events were recorded in "parasitic mode" between individual e(+)e(-) interactions and the total live time of this data taking is equivalent to 1.6 x 10(6) s. The DELPHI apparatus is located about 100 m underground and the 84 metres rock overburden imposes a cutoff of about 52 GeV/c on muon momenta. The data from the large volume Hadron Calorimeter allowed the muon multiplicity of 54,201 events to be reconstructed. The resulting muon multiplicity distribution is compared with the prediction of the Monte Carlo simulation based on CORSIKA/QGSJETOI. The model fails to describe the abundance of high multiplicity events. The impact of QGSJET internal parameters on the results is also studied.

  • 19. Abdallah et al., DELPHI Collaboration: J
    et al.
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics.
    Study of triple-gauge-boson couplings ZZZ, ZZ gamma and z gamma gamma at LEP2007In: European Physical Journal C, ISSN 1434-6044, E-ISSN 1434-6052, Vol. 51, no 3, p. 525-542Article in journal (Refereed)
  • 20. Abdallah et al., DELPHI Collaboration: J
    et al.
    Åsman, Barbro
    Stockholm University, Faculty of Science, Department of Physics.
    Berntzon, Lisa
    Stockholm University, Faculty of Science, Department of Physics.
    Dalmau, Jörgen
    Stockholm University, Faculty of Science, Department of Physics.
    Holmgren, Sven-Olof
    Stockholm University, Faculty of Science, Department of Physics.
    Hultqvist, Klas
    Stockholm University, Faculty of Science, Department of Physics.
    Johansson, E. K.
    Stockholm University, Faculty of Science, Department of Physics.
    Johansson, P. D.
    Stockholm University, Faculty of Science, Department of Physics.
    Leinonen, Lena
    Stockholm University, Faculty of Science, Department of Physics.
    Lipniacka, Anna
    Stockholm University, Faculty of Science, Department of Physics.
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics.
    A Measurement of the Tau Hadronic Branching Ratios2006In: European Physical Journal C, ISSN 1434-6044, E-ISSN 1434-6052, Vol. 46, no 1, p. 1-26Article in journal (Refereed)
  • 21. Abdallah et al., DELPHI Collaboration: J
    et al.
    Åsman, Barbro
    Stockholm University, Faculty of Science, Department of Physics.
    Berntzon, Lisa
    Stockholm University, Faculty of Science, Department of Physics.
    Dalmau, Jörgen
    Stockholm University, Faculty of Science, Department of Physics.
    Holmgren, Sven-Olof
    Stockholm University, Faculty of Science, Department of Physics.
    Hultqvist, Klas
    Stockholm University, Faculty of Science, Department of Physics.
    Johansson, E. K.
    Stockholm University, Faculty of Science, Department of Physics.
    Johansson, P. D.
    Stockholm University, Faculty of Science, Department of Physics.
    Leinonen, Lena
    Stockholm University, Faculty of Science, Department of Physics.
    Lipniacka, Anna
    Stockholm University, Faculty of Science, Department of Physics.
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics.
    Evidence for an Excess of Soft Photons in Hadronic Decays of $Z^0$2006In: European Physical Journal C, ISSN 1434-6044, E-ISSN 1434-6052, Vol. 47, no 2, p. 273-294Article in journal (Refereed)
    Abstract [en]

    Soft photons inside hadronic jets converted in front of the DELPHI main tracker (TPC) in events of qq̄ disintegrations of the Z0 were studied in the kinematic range 0.2<Eγ<1 GeV and transverse momentum with respect to the closest jet direction pT<80 MeV/c. A clear excess of photons in the experimental data as compared to the Monte Carlo predictions is observed. This excess (uncorrected for the photon detection efficiency) is (1.17±0.06±0.27)×10-3 γ/jet in the specified kinematic region, while the expected level of the inner hadronic bremsstrahlung (which is not included in the Monte Carlo) is (0.340±0.001±0.038)×10-3 γ/jet. The ratio of the excess to the predicted bremsstrahlung rate is then (3.4±0.2±0.8), which is similar in strength to the anomalous soft photon signal observed in fixed target experiments with hadronic beams.

  • 22. Abdallah et al., DELPHI Collaboration: J
    et al.
    Åsman, Barbro
    Stockholm University, Faculty of Science, Department of Physics.
    Berntzon, Lisa
    Stockholm University, Faculty of Science, Department of Physics.
    Dalmau, Jörgen
    Stockholm University, Faculty of Science, Department of Physics.
    Holmgren, Sven-Olof
    Stockholm University, Faculty of Science, Department of Physics.
    Hultqvist, Klas
    Stockholm University, Faculty of Science, Department of Physics.
    Johansson, E. K.
    Stockholm University, Faculty of Science, Department of Physics.
    Johansson, P. D.
    Stockholm University, Faculty of Science, Department of Physics.
    Leinonen, Lena
    Stockholm University, Faculty of Science, Department of Physics.
    Lipniacka, Anna
    Stockholm University, Faculty of Science, Department of Physics.
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics.
    Measurement and interpretation of fermion-pair production at LEP energies above the Z resonance2006In: European Physical Journal C, ISSN 1434-6044, E-ISSN 1434-6052, Vol. 45, no 3, p. 589-632Article in journal (Refereed)
  • 23. Abdallah et al., DELPHI Collaboration: J
    et al.
    Åsman, Barbro
    Stockholm University, Faculty of Science, Department of Physics.
    Berntzon, Lisa
    Stockholm University, Faculty of Science, Department of Physics.
    Dalmau, Jörgen
    Stockholm University, Faculty of Science, Department of Physics.
    Holmgren, Sven-Olof
    Stockholm University, Faculty of Science, Department of Physics.
    Hultqvist, Klas
    Stockholm University, Faculty of Science, Department of Physics.
    Johansson, E. K.
    Stockholm University, Faculty of Science, Department of Physics.
    Johansson, P. D.
    Stockholm University, Faculty of Science, Department of Physics.
    Leinonen, Lena
    Stockholm University, Faculty of Science, Department of Physics.
    Lipniacka, Anna
    Stockholm University, Faculty of Science, Department of Physics.
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics.
    Search for Excited Leptons in in e+e- Collisions at $sqrt{s}=189-209$ GeV2006In: European Physical Journal C, ISSN 1434-6044, E-ISSN 1434-6052, Vol. 46, no 2, p. 277-293Article in journal (Refereed)
  • 24. Abdallah et al., DELPHI Collaboration: J
    et al.
    Åsman, Barbro
    Stockholm University, Faculty of Science, Department of Physics.
    Berntzon, Lisa
    Stockholm University, Faculty of Science, Department of Physics.
    Dalmau, Jörgen
    Stockholm University, Faculty of Science, Department of Physics.
    Holmgren, Sven-Olof
    Stockholm University, Faculty of Science, Department of Physics.
    Hultqvist, Klas
    Stockholm University, Faculty of Science, Department of Physics.
    Johansson, E. K.
    Stockholm University, Faculty of Science, Department of Physics.
    Johansson, P. D.
    Stockholm University, Faculty of Science, Department of Physics.
    Leinonen, Lena
    Stockholm University, Faculty of Science, Department of Physics.
    Lipniacka, Anna
    Stockholm University, Faculty of Science, Department of Physics.
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics.
    Search for ηb in two-photon collisions at LEP II with the DELPHI detector2006In: Physics Letters B, ISSN 0370-2693, E-ISSN 1873-2445, Vol. 634, no 4, p. 340-346Article in journal (Refereed)
  • 25. Abdallah et al., DELPHI Collaboration: J
    et al.
    Åsman, Barbro
    Stockholm University, Faculty of Science, Department of Physics.
    Berntzon, Lisa
    Stockholm University, Faculty of Science, Department of Physics.
    Dalmau, Jörgen
    Stockholm University, Faculty of Science, Department of Physics.
    Holmgren, Sven-Olof
    Stockholm University, Faculty of Science, Department of Physics.
    Hultqvist, Klas
    Stockholm University, Faculty of Science, Department of Physics.
    Johansson, K. E.
    Stockholm University, Faculty of Science, Department of Physics.
    Johansson, P. D.
    Stockholm University, Faculty of Science, Department of Physics.
    Leinonen, Lena
    Stockholm University, Faculty of Science, Department of Physics.
    Lipniacka, Anna
    Stockholm University, Faculty of Science, Department of Physics.
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics.
    Determination of the b quark mass at the MZ scale with the DELPHI detector at LEP2006In: European Physical Journal C, ISSN 1434-6044, E-ISSN 1434-6052, Vol. 46, no 3, p. 569-583Article in journal (Refereed)
  • 26. Abdallah et al., DELPHI Collaboration: J
    et al.
    Åsman, Barbro
    Stockholm University, Faculty of Science, Department of Physics.
    Berntzon, Lisa
    Stockholm University, Faculty of Science, Department of Physics.
    Dalmau, Jörgen
    Stockholm University, Faculty of Science, Department of Physics.
    Holmgren, Sven-Olof
    Stockholm University, Faculty of Science, Department of Physics.
    Hultqvist, Klas
    Stockholm University, Faculty of Science, Department of Physics.
    Johansson, K. E.
    Stockholm University, Faculty of Science, Department of Physics.
    Johansson, P. D.
    Stockholm University, Faculty of Science, Department of Physics.
    Leinonen, Lena
    Stockholm University, Faculty of Science, Department of Physics.
    Lipniacka, Anna
    Stockholm University, Faculty of Science, Department of Physics.
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics.
    Study of double-tagged γγ events at LEPII2006In: European Physical Journal C, ISSN 1434-6044, E-ISSN 1434-6052, Vol. 46, no 3, p. 559-568Article in journal (Refereed)
  • 27. Abdallah et al., DELPHI Collaboration: J
    et al.
    Åsman, Barbro
    Stockholm University, Faculty of Science, Department of Physics.
    Berntzon, Lisa
    Stockholm University, Faculty of Science, Department of Physics.
    Dalmau, Jörgen
    Stockholm University, Faculty of Science, Department of Physics.
    Holmgren, Sven-Olof
    Stockholm University, Faculty of Science, Department of Physics.
    Hultqvist, Klas
    Stockholm University, Faculty of Science, Department of Physics.
    Johansson, K.
    Stockholm University, Faculty of Science, Department of Physics.
    Johansson, D.
    Stockholm University, Faculty of Science, Department of Physics.
    Leinonen, Lena
    Stockholm University, Faculty of Science, Department of Physics.
    Lipniacka, Anna
    Stockholm University, Faculty of Science, Department of Physics.
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics.
    Determination of Heavy Quark Non-Perturbative Parameters from Spectral Moments in Semileptonic B Decays2006In: European Physical Journal C, ISSN 1434-6044, E-ISSN 1434-6052, Vol. 45, no 1, p. 35-59Article in journal (Refereed)
  • 28. Abdallah et al., DELPHI Collaboration: J
    et al.
    Åsman, Barbro
    Stockholm University, Faculty of Science, Department of Physics.
    Berntzon, Lisa
    Stockholm University, Faculty of Science, Department of Physics.
    Dalmau, Jörgen
    Stockholm University, Faculty of Science, Department of Physics.
    Holmgren, Sven-Olof
    Stockholm University, Faculty of Science, Department of Physics.
    Hultqvist, Klas
    Stockholm University, Faculty of Science, Department of Physics.
    Johansson, K.
    Stockholm University, Faculty of Science, Department of Physics.
    Johansson, D.
    Stockholm University, Faculty of Science, Department of Physics.
    Leinonen, Lena
    Stockholm University, Faculty of Science, Department of Physics.
    Lipniacka, Anna
    Stockholm University, Faculty of Science, Department of Physics.
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics.
    Single Intermediate Vector Boson Production in e + e- Collisions * at $sqrt{s}= 183 - 209$ GeV2006In: European Physical Journal C, ISSN 1434-6044, E-ISSN 1434-6052, Vol. 45, no 2, p. 273-289Article in journal (Refereed)
  • 29. Abdallah et al., DELPHI Collaboration: J
    et al.
    Åsman, Barbro
    Stockholm University, Faculty of Science, Department of Physics.
    Berntzon, Lisa
    Stockholm University, Faculty of Science, Department of Physics.
    Dalmau, Jörgen
    Stockholm University, Faculty of Science, Department of Physics.
    Holmgren, Sven-Olof
    Stockholm University, Faculty of Science, Department of Physics.
    Johansson, E. K.
    Stockholm University, Faculty of Science, Department of Physics.
    Johansson, P. D.
    Stockholm University, Faculty of Science, Department of Physics.
    Leinonen, Lena
    Stockholm University, Faculty of Science, Department of Physics.
    Lipniacka, Anna
    Stockholm University, Faculty of Science, Department of Physics.
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics.
    Niss, P.
    Stockholm University, Faculty of Science, Department of Physics.
    Walck, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    Masses, Lifetimes and Production Rates of $Xi^-$ and $-arXi^+$ at LEP 12006In: Physics Letters B, ISSN 0370-2693, E-ISSN 1873-2445, Vol. 639, no 3-4, p. 179-191Article in journal (Refereed)
  • 30. Abdallah et al., DELPHI Collaboration: J
    et al.
    Åsman, Barbro
    Stockholm University, Faculty of Science, Department of Physics.
    Berntzon, Lisa
    Stockholm University, Faculty of Science, Department of Physics.
    Dalmau, Jörgen
    Stockholm University, Faculty of Science, Department of Physics.
    Holmgren, Sven-Olof
    Stockholm University, Faculty of Science, Department of Physics.
    Johansson, Erik
    Stockholm University, Faculty of Science, Department of Physics.
    Johansson, P. D.
    Stockholm University, Faculty of Science, Department of Physics.
    Leinonen, Lena
    Stockholm University, Faculty of Science, Department of Physics.
    Lipniacka, Anna
    Stockholm University, Faculty of Science, Department of Physics.
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics.
    Study of Leading Hadrons in Gluon and Quark Fragmentation2006In: Physics Letters B, ISSN 0370-2693, E-ISSN 1873-2445, Vol. 643, no 3-4, p. 147-157Article in journal (Refereed)
    Abstract [en]

    The study of quark jets in e+e reactions at LEP has demonstrated that the hadronisation process is reproduced well by the Lund string model. However, our understanding of gluon fragmentation is less complete. In this study enriched quark and gluon jet samples of different purities are selected in three-jet events from hadronic decays of the Z collected by the DELPHI experiment in the LEP runs during 1994 and 1995. The leading systems of the two kinds of jets are defined by requiring a rapidity gap and their sum of charges is studied. An excess of leading systems with total charge zero is found for gluon jets in all cases, when compared to Monte Carlo simulations with JETSET (with and without Bose–Einstein correlations included) and ARIADNE. The corresponding leading systems of quark jets do not exhibit such an excess. The influence of the gap size and of the gluon purity on the effect is studied and a concentration of the excess of neutral leading systems at low invariant masses (2 GeV/c2) is observed, indicating that gluon jets might have an additional hitherto undetected fragmentation mode via a two-gluon system. This could be an indication of a possible production of gluonic states as predicted by QCD.

  • 31. Abdallah et al., DELPHI Collaboration: J
    et al.
    Åsman, Barbro
    Stockholm University, Faculty of Science, Department of Physics.
    Holmgren, Sven-Olof
    Stockholm University, Faculty of Science, Department of Physics.
    Johansson, Erik
    Stockholm University, Faculty of Science, Department of Physics.
    Leinonen, Lena
    Stockholm University, Faculty of Science, Department of Physics.
    Lipniacka, Anna
    Stockholm University, Faculty of Science, Department of Physics.
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics.
    Search for Pentaquarks in the Hadronic Decays of the Z Boson with the DELPHI Detector at LEP2007In: Physics Letters B, ISSN 0370-2693, E-ISSN 1873-2445, Vol. 653, no 2-4, p. 151-160Article in journal (Refereed)
    Abstract [en]

    The quark model does not exclude states composed of more than three quarks, like pentaquark systems. Controversial evidence for such states has been published in the last years, in particular: for a strange pentaquark Theta(1540)(+); for a double-strange state, the Xi(1862)(--), subsequently called Phi(1860)--; and for a charmed state, the Theta(c)(3100)(0). If confirmed, a full pentaquark family might exist; such pentaquark states could be produced in e(+)e(-) annihilations near the Z energy. In this Letter a search for pentaquarks is described using the DELPHI detector at LEP, characterized by powerful particle identification sub-systems crucial in the separation of the signal from the background for these states. At 95% CL, upper limits are set on the production rates N of such particles and their charge-conjugate state per Z decay: N-Theta+ x Br(Theta(+) -> pK(S)(0)) < 5.1 x 10(-4), N Theta++ < 1.6 x 10(-3), N Phi(1860)-- x Br((P(1860)-- -> Xi(-)pi(-)) < 2.9 x 10(-4), N-Theta c(3100)0 x Br(Theta(c)(3100)(0) -> D*(+)p) < 8.8 x 10(-4).

  • 32. Abdallah et al., DELPHI Collaboration: J
    et al.
    Åsman, Barbro
    Stockholm University, Faculty of Science, Department of Physics.
    Holmgren, Sven-Olof
    Stockholm University, Faculty of Science, Department of Physics.
    Johansson, Erik
    Stockholm University, Faculty of Science, Department of Physics.
    Leinonen, Lena
    Stockholm University, Faculty of Science, Department of Physics.
    Lipniacka, Anna
    Stockholm University, Faculty of Science, Department of Physics.
    Moa, Torbjörn
    Stockholm University, Faculty of Science, Department of Physics.
    Z gamma* production in e(+) e(-) interactions at root s=183-209 GeV2007In: European Physical Journal C, ISSN 1434-6044, E-ISSN 1434-6052, Vol. 51, no 3, p. 503-523Article in journal (Refereed)
    Abstract [en]

    Measurements of Z gamma* production are presented using data collected by the DELPHI detector at centre-of-mass energies ranging from 183 to 209 GeV, corresponding to an integrated luminosity of about 667 pb(-1). The measurements cover a wide range of the possible final state four-fermion configurations: hadronic and leptonic (e(+) e(-) q (q) over bar, mu(+) mu(-) q (q) over bar ,q (q) over barv (v) over bar), fully leptonic (l(+) l(-) l' (+) l'(-)) and fully hadronic. nal states (q (q) over barq (q) over bar, with a low mass q (q$) over bar pair). Measurements of the Z gamma* cross-section for the various. nal states have been compared with the Standard Model expectations and found to be consistent within the errors. In addition, a total cross-section measurement of the l(+) l(-) l'(+)l'(-) cross-section is reported, and found to be in agreement with the prediction of the Standard Model.

  • 33. Abdallah, H.
    et al.
    Abramowski, A.
    Aharonian, F.
    Benkhali, F. Ait
    Akhperjanian, A. G.
    Anguener, E.
    Arrieta, M.
    Aubert, P.
    Backes, M.
    Balzer, A.
    Barnard, M.
    Becherini, Y.
    Tjus, J. Becker
    Berge, D.
    Bernhard, S.
    Bernloehr, K.
    Birsin, E.
    Blackwell, R.
    Bottcher, M.
    Boisson, C.
    Bolmont, J.
    Bordas, P.
    Bregeon, J.
    Brun, F.
    Brun, P.
    Bryan, M.
    Bulik, T.
    Capasso, M.
    Carr, J.
    Casanova, S.
    Chakraborty, N.
    Chalme-Calvet, R.
    Chaves, R. C. G.
    Chen, A.
    Chevalier, J.
    Chretien, M.
    Colafrancesco, S.
    Cologna, G.
    Condon, B.
    Conrad, Jan
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC). Wallenberg Academy Fellow, Sweden.
    Couturier, C.
    Cui, Y.
    Davids, I. D.
    Degrange, B.
    Deil, C.
    deWilt, P.
    Djannati-Atai, A.
    Domainko, W.
    Donath, A.
    Drury, L. O'C.
    Dubus, G.
    Dutson, K.
    Dyks, J.
    Dyrda, M.
    Edwards, T.
    Egberts, K.
    Eger, P.
    Ernenwein, J. -P.
    Eschbach, S.
    Farnier, Christian
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Fegan, S.
    Fernandes, M. V.
    Fiasson, A.
    Fontaine, G.
    Foerster, A.
    Funk, S.
    Fuessling, M.
    Gabici, S.
    Gajdus, M.
    Gallant, Y. A.
    Garrigoux, T.
    Giavitto, G.
    Giebels, B.
    Glicenstein, J. F.
    Gottschall, D.
    Goyal, A.
    Grondin, M. -H.
    Grudzinska, M.
    Hadasch, D.
    Hahn, J.
    Hawkes, J.
    Heinzelmann, G.
    Henri, G.
    Hermann, G.
    Hervet, O.
    Hillert, A.
    Hinton, J. A.
    Hofmann, W.
    Hoischen, C.
    Holler, M.
    Horns, D.
    Ivascenko, A.
    Jacholkowska, A.
    Jamrozy, M.
    Janiak, M.
    Jankowsky, D.
    Jankowsky, F.
    Jingo, M.
    Jogler, T.
    Jouvin, L.
    Jung-Richardt, I.
    Kastendieck, M. A.
    Katarzynski, K.
    Katz, U.
    Kerszberg, D.
    Khelifi, B.
    Kieffer, M.
    King, J.
    Klepser, S.
    Klochkov, D.
    Kluzniak, W.
    Kolitzus, D.
    Komin, Nu.
    Kosack, K.
    Krakau, S.
    Kraus, M.
    Krayzel, F.
    Kruger, P. P.
    Laffon, H.
    Lamanna, G.
    Lau, J.
    Lees, J. -P.
    Lefaucheur, J.
    Lefranc, V.
    Lemiere, A.
    Lemoine-Goumard, M.
    Lenain, J. -P.
    Leser, E.
    Lohse, T.
    Lorentz, M.
    Lui, R.
    Lypova, I.
    Marandon, V.
    Marcowith, A.
    Mariaud, C.
    Marx, R.
    Maurin, G.
    Maxted, N.
    Mayer, M.
    Meintjes, P. J.
    Menzler, U.
    Meyer, Manuel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Mitchell, A. M. W.
    Moderski, R.
    Mohamed, M.
    Morå, Knut
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Moulin, E.
    Murach, T.
    de Naurois, M.
    Niederwanger, F.
    Niemiec, J.
    Oakes, L.
    Odaka, H.
    Ohm, S.
    Oettl, S.
    Ostrowski, M.
    Oya, I.
    Padovani, M.
    Panter, M.
    Parsons, R. D.
    Arribas, M. Paz
    Pekeur, N. W.
    Pelletier, G.
    Petrucci, P. -O.
    Peyaud, B.
    Pita, S.
    Poon, H.
    Prokhorov, D.
    Prokoph, H.
    Puehlhofer, G.
    Punch, M.
    Quirrenbach, A.
    Raab, S.
    Reimer, A.
    Reimer, O.
    Renaud, M.
    de los Reyes, R.
    Rieger, F.
    Romoli, C.
    Rosier-Lees, S.
    Rowell, G.
    Rudak, B.
    Rulten, C. B.
    Sahakian, V.
    Salek, D.
    Sanchez, D. A.
    Santangelo, A.
    Sasaki, M.
    Schlickeiser, R.
    Schussler, F.
    Schulz, A.
    Schwanke, U.
    Schwemmer, S.
    Seyffert, A. S.
    Shafi, N.
    Simoni, R.
    Sol, H.
    Spanier, F.
    Spengler, Gerrit
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Spiess, F.
    Stawarz, L.
    Steenkamp, R.
    Stegmann, C.
    Stinzing, F.
    Stycz, K.
    Sushch, I.
    Tavernet, J. -P.
    Tavernier, T.
    Taylor, A. M.
    Terrier, R.
    Tluczykont, M.
    Trichard, C.
    Tuffs, R.
    van der Walt, J.
    van Eldik, C.
    van Soelen, B.
    Vasileiadis, G.
    Veh, J.
    Venter, C.
    Viana, A.
    Vincent, P.
    Vink, J.
    Voisin, F.
    Voelk, H. J.
    Vuillaume, T.
    Wadiasingh, Z.
    Wagner, S. J.
    Wagner, P.
    Wagner, Robert M.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    White, R.
    Wierzcholska, A.
    Willmann, P.
    Woernlein, A.
    Wouters, D.
    Yang, R.
    Zabalza, V.
    Zaborov, D.
    Zacharias, M.
    Zdziarski, A. A.
    Zech, A.
    Zefi, F.
    Ziegler, A.
    Zywucka, N.
    Search for Dark Matter Annihilations towards the Inner Galactic Halo from 10 Years of Observations with HESS2016In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 117, no 11, article id 111301Article in journal (Refereed)
    Abstract [en]

    The inner region of the Milky Way halo harbors a large amount of dark matter (DM). Given its proximity, it is one of the most promising targets to look for DM. We report on a search for the annihilations of DM particles using gamma-ray observations towards the inner 300 pc of the Milky Way, with the H.E.S.S. array of ground-based Cherenkov telescopes. The analysis is based on a 2D maximum likelihood method using Galactic Center (GC) data accumulated by H.E.S.S. over the last 10 years (2004-2014), and does not show any significant gamma-ray signal above background. Assuming Einasto and Navarro-Frenk-White DM density profiles at the GC, we derive upper limits on the annihilation cross section <sigma nu >. These constraints are the strongest obtained so far in the TeV DM mass range and improve upon previous limits by a factor 5. For the Einasto profile, the constraints reach <sigma nu > values of 6 x 10(-26) cm(3) s(-1) in the W+W- channel for a DM particle mass of 1.5 TeV, and 2 x 10(-26) cm(3) s(-1) in the tau(+)tau(-) channel for a 1 TeV mass. For the first time, ground-based gamma-ray observations have reached sufficient sensitivity to probe <sigma nu > values expected from the thermal relic density for TeV DM particles.

  • 34.
    Abdallah, J.
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    , et al
    Search for SUSY in the AMSB scenario with the DELPHI detector2004In: Eur. Phys. J., Vol. C, no 34, p. 145-156Article in journal (Refereed)
  • 35.
    Abdallah, J.
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    , et al
    Searches for supersymmetric particles in $e^+e^-$ collisions up to 208~GeV,2003In: Eur. Phys. J., Vol. C, no 31, p. 421-479Article in journal (Refereed)
  • 36. Abdallah, J.
    et al.
    Adragna, P.
    Alexa, C.
    Alves, R.
    Amaral, P.
    Ananiev, A.
    Anderson, K.
    Andresen, X.
    Antonaki, A.
    Batusov, V.
    Bednar, P.
    Behrens, A.
    Bergeås, Elin
    Stockholm University, Faculty of Science, Department of Physics.
    Biscarat, C.
    Blanch, O.
    Blanchot, G.
    Blocki, J.
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    Boldea, V.
    Bosi, F.
    Bosman, M.
    Bromberg, C.
    Brunel, B.
    Budagov, J.
    Calderon, D.
    Calvet, D.
    Cardeira, C.
    Carli, T.
    Carvalho, J.
    Cascella, M.
    Castillo, M. V.
    Costello, J.
    Cavalli-Sforza, M.
    Cavasinni, V.
    Cerqueira, A. S.
    Clément, Christophe
    Stockholm University, Faculty of Science, Department of Physics. CERN, Geneva, Switzerland.
    Cobal, M.
    Cogswell, F.
    Constantinescu, S.
    Costanzo, D.
    Da Silva, P.
    David, M.
    Davidek, T.
    Dawson, J.
    De, K.
    Del Prete, T.
    Di Girolamo, B.
    Dita, S.
    Dolejsi, J.
    Dolezal, Z.
    Dotti, A.
    Downing, R.
    Drake, G.
    Efthymiopoulos, I.
    Errede, D.
    Errede, S.
    Farbin, A.
    Fassouliotis, D.
    Feng, E.
    Fenyuk, A.
    Ferdi, C.
    Ferreira, B. C.
    Ferrer, A.
    Ferrer, J.
    Flaminio, V.
    Flix, J.
    Francavilla, P.
    Fullana, E.
    Garde, V.
    Gaydee, J. C.
    Gellerstedt, Karl
    Stockholm University, Faculty of Science, Department of Physics.
    Giakoumopoulou, V.
    Giangiobbe, V.
    Gildemeister, O.
    Gilewsky, V.
    Giokaris, N.
    Gollub, N.
    Gomes, A.
    Gonzalez, V.
    Gouveia, J.
    Grenier, P.
    Gris, P.
    Grudzinski, J.
    Guarino, V.
    Guicheney, C.
    Gupta, A.
    Hakobyan, H.
    Haney, M.
    Hellman, Sten
    Stockholm University, Faculty of Science, Department of Physics.
    Henriques, A.
    Higon, E.
    Hill, N.
    Holmgren, Sven-Olof
    Stockholm University, Faculty of Science, Department of Physics.
    Hruska, I.
    Hurwitz, M.
    Huston, J.
    Jen-La Plante, I.
    Jon-And, Kerstin
    Stockholm University, Faculty of Science, Department of Physics.
    Junk, T.
    Karyukhin, A.
    Khubua, J.
    Klereborn, Jonas
    Stockholm University, Faculty of Science, Department of Physics.
    Kopikov, S.
    Korolkov, I.
    Krivkova, P.
    Kulchitsky, Y.
    Kurochkin, Y.
    Kuzhir, P.
    Lapin, V.
    Lasseure, C.
    LeCompte, T.
    Lefevre, R.
    Leitner, R.
    Li, J.
    Lyablin, M.
    Lim, H.
    Lokajicek, M.
    Lomakin, Y.
    Lourtie, P.
    Lovas, L.
    Lupi, A.
    Maidantchik, C.
    Maio, A.
    Maliukov, S.
    Manousakis, A.
    Marques, C.
    Marroquim, F.
    Martin, F.
    Mazzoni, E.
    Mergelkuhl, D.
    Merritt, F.
    Miagkov, A.
    Miller, R.
    Minashvili, I.
    Miralles, L.
    Montarou, G.
    Nemecek, S.
    Nessi, M.
    Nikitine, I.
    Nodulman, L.
    Norniella, O.
    Nyman, T.
    Onofre, A.
    Oreglia, M.
    Palan, B.
    Pallin, D.
    Pantea, D.
    Pereira, A.
    Pilcher, J.
    Pina, J.
    Pinhao, J.
    Pod, E.
    Podlyski, F.
    Portell, X.
    Poveda, J.
    Pribyl, L.
    Price, L. E.
    Proudfoot, J.
    Ramalho, M.
    Ramstedt, Magnus
    Stockholm University, Faculty of Science, Department of Physics.
    Raposeiro, L.
    Reis, J.
    Richards, R.
    Roda, C.
    Romanov, V.
    Rose-Dulcina, L.
    Rosnet, P.
    Roy, P.
    Ruiz, A.
    Rumiantsau, V.
    Russakovich, N.
    da Costa, J. Sa
    Salto, O.
    Salvachua, B.
    Sanchis, E.
    Sanders, H.
    Santoni, C.
    Santos, J.
    Saraiva, J. G.
    Sarri, F.
    Says, L. -P
    Schlager, G.
    Schlereth, J.
    Seixas, J. M.
    Sellden, Björn
    Stockholm University, Faculty of Science, Department of Physics.
    Shalanda, N.
    Shchelchkov, A.
    Shevtsov, P.
    Shochet, M.
    Silva, J.
    Simaitis, V.
    Simonyan, M.
    Sissakian, A.
    Sjölin, Jörgen
    Stockholm University, Faculty of Science, Department of Physics.
    Skrzecz, F.
    Solans, C.
    Solodkov, A.
    Solovianov, O.
    Sorokina, J.
    Sosebee, M.
    Spano, F.
    Speckmeyer, P.
    Stanek, R.
    Starchenko, E.
    Starovoitov, P.
    Suk, M.
    Sykora, I.
    Tang, F.
    Tas, P.
    Teuscher, R.
    Tokar, S.
    Topilin, N.
    Torres, J.
    Underwood, D.
    Usai, G.
    Utkin, V.
    Valero, A.
    Valkar, S.
    Valls, J. A.
    Vartapetian, A.
    Vazeille, F.
    Vellidis, C.
    Ventura, F.
    Vichou, I.
    Vivarelli, I.
    Volpi, M.
    White, A.
    Wood, K.
    Zaitsev, A.
    Zenin, A.
    Zenis, T.
    Zenonos, Z.
    Zenz, S.
    Zilka, B.
    Mechanical construction and installation of the ATLAS tile calorimeter2013In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 8, p. T11001-Article in journal (Refereed)
    Abstract [en]

    This paper summarises the mechanical construction and installation of the Tile Calorimeter for the ATLAS experiment at the Large Hadron Collider in CERN, Switzerland. The Tile Calorimeter is a sampling calorimeter using scintillator as the sensitive detector and steel as the absorber and covers the central region of the ATLAS experiment up to pseudorapidities +/- 1.7. The mechanical construction of the Tile Calorimeter occurred over a period of about 10 years beginning in 1995 with the completion of the Technical Design Report and ending in 2006 with the installation of the final module in the ATLAS cavern. During this period approximately 2600 metric tons of steel were transformed into a laminated structure to form the absorber of the sampling calorimeter. Following instrumentation and testing, which is described elsewhere, the modules were installed in the ATLAS cavern with a remarkable accuracy for a structure of this size and weight.

  • 37. Abdallah, J.
    et al.
    Adragna, P.
    Alexa, C.
    Alves, R.
    Amaral, P.
    Ananiev, A.
    Anderson, K.
    Andresen, X.
    Antonaki, A.
    Batusov, V.
    Bednar, P.
    Bergeås, Elin
    Stockholm University, Faculty of Science, Department of Physics.
    Biscarat, C.
    Blanch, O.
    Blanchot, G.
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    Boldea, V.
    Bosi, F.
    Bosman, M.
    Bromberg, C.
    Budagov, J.
    Calvet, D.
    Cardeira, C.
    Carli, T.
    Carvalho, J.
    Cascella, M.
    Castillo, M. V.
    Costelo, J.
    Cavalli-Sforza, M.
    Cavasinni, V.
    Cerqueira, A. S.
    Clément, Christophe
    Stockholm University, Faculty of Science, Department of Physics.
    Cobal, M.
    Cogswell, F.
    Constantinescu, S.
    Costanzo, D.
    Da Silva, P.
    David, M.
    Davidek, T.
    Dawson, J.
    De, K.
    Del Prete, T.
    Diakov, E.
    Di Girolamo, B.
    Dita, S.
    Dolejsi, J.
    Dolezal, Z.
    Dotti, A.
    Downing, R.
    Drake, G.
    Efthymiopoulos, I.
    Errede, D.
    Errede, S.
    Farbin, A.
    Fassouliotis, D.
    Feng, E.
    Fenyuk, A.
    Ferdi, C.
    Ferreira, B. C.
    Ferrer, A.
    Flaminio, V.
    Flix, J.
    Francavilla, P.
    Fullana, E.
    Garde, V.
    Gellerstedt, Karl
    Stockholm University, Faculty of Science, Department of Physics.
    Giakoumopoulou, V.
    Giangiobbe, V.
    Gildemeister, O.
    Gilewsky, V.
    Giokaris, N.
    Gollub, N.
    Gomes, A.
    Gonzalez, V.
    Gouveia, J.
    Grenier, P.
    Gris, P.
    Guarino, V.
    Guicheney, C.
    Gupta, A.
    Hakobyan, H.
    Haney, M.
    Hellman, Sten
    Stockholm University, Faculty of Science, Department of Physics.
    Henriques, A.
    Higon, E.
    Hill, N.
    Holmgren, Sven-Olof
    Stockholm University, Faculty of Science, Department of Physics.
    Hruska, I.
    Hurwitz, M.
    Huston, J.
    Plante, I. Jen-La
    Jon-And, Kerstin
    Stockholm University, Faculty of Science, Department of Physics.
    Junk, T.
    Karyukhin, A.
    Khubua, J.
    Klereborn, Jonas
    Stockholm University, Faculty of Science, Department of Physics.
    Konstantinov, V.
    Kopikov, S.
    Korolkov, I.
    Krivkova, P.
    Kulchitsky, Y.
    Kurochkin, Yu
    Kuzhir, P.
    Lapin, V.
    LeCompte, T.
    Lefevre, R.
    Leitner, R.
    Li, J.
    Liablin, M.
    Lokajicek, M.
    Lomakin, Y.
    Lourtie, P.
    Lovas, L.
    Lupi, A.
    Maidantchik, C.
    Maio, A.
    Maliukov, S.
    Manousakis, A.
    Marques, C.
    Marroquim, F.
    Martin, F.
    Mazzoni, E.
    Merritt, F.
    Miagkov, A.
    Miller, R.
    Minashvili, I.
    Miralles, L.
    Montarou, G.
    Nemecek, S.
    Nessi, M.
    Nikitine, I.
    Nodulman, L.
    Norniella, O.
    Onofre, A.
    Oreglia, M.
    Palan, B.
    Pallin, D.
    Pantea, D.
    Pereira, A.
    Pilcher, J.
    Pina, J.
    Pinhao, J.
    Pod, E.
    Podlyski, F.
    Portell, X.
    Poveda, J.
    Pribyl, L.
    Price, E.
    Proudfoot, J.
    Ramalho, M.
    Ramstedt, Magnus
    Stockholm University, Faculty of Science, Department of Physics.
    Raposeiro, L.
    Reis, J.
    Richards, R.
    Roda, C.
    Romanov, V.
    Rosnet, P.
    Roy, P.
    Ruiz, A.
    Rumiantsau, V.
    Russakovich, N.
    Da Costa, J. Sa
    Salto, O.
    Salvachua, B.
    Sanchis, E.
    Sanders, H.
    Santoni, C.
    Santos, J.
    Saraiva, J. G.
    Sarri, F.
    Says, L. -P
    Schlager, G.
    Schlereth, J.
    Seixas, J. M.
    Sellden, Björn
    Stockholm University, Faculty of Science, Department of Physics.
    Shalanda, N.
    Shevtsov, P.
    Shochet, M.
    Silva, J.
    Simaitis, V.
    Simonyan, M.
    Sissakian, A.
    Sjölin, Jörgen
    Stockholm University, Faculty of Science, Department of Physics.
    Solans, C.
    Solodkov, A.
    Solovianov, O.
    Sosebee, M.
    Spano, F.
    Speckmeyer, P.
    Stanek, R.
    Starchenko, E.
    Starovoitov, P.
    Suk, M.
    Sykora, I.
    Tang, F.
    Tas, P.
    Teuscher, R.
    Tischenko, M.
    Tokar, S.
    Topilin, N.
    Torres, J.
    Underwood, D.
    Usai, G.
    Valero, A.
    Valkar, S.
    Valls, J. A.
    Vartapetian, A.
    Vazeille, F.
    Vellidis, C.
    Ventura, F.
    Vichou, I.
    Vivarelli, I.
    Volpi, M.
    White, A.
    Zaitsev, A.
    Zaytsev, Yu
    Zenin, A.
    Zenis, T.
    Zenonos, Z.
    Zenz, S.
    Zilka, B.
    The optical instrumentation of the ATLAS Tile Calorimeter2013In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 8, p. P01005-Article in journal (Refereed)
    Abstract [en]

    The Tile Calorimeter, covering the central region of the ATLAS experiment up to pseudorapidities of +/-1.7, is a sampling device built with scintillating tiles that alternate with iron plates. The light is collected in wave-length shifting (WLS) fibers and is read out with photomultipliers. In the characteristic geometry of this calorimeter the tiles lie in planes perpendicular to the beams, resulting in a very simple and modular mechanical and optical layout. This paper focuses on the procedures applied in the optical instrumentation of the calorimeter, which involved the assembly of about 460,000 scintillator tiles and 550,000 WLS fibers. The outcome is a hadronic calorimeter that meets the ATLAS performance requirements, as shown in this paper.

  • 38. Abdallah, J.
    et al.
    Alexa, C.
    Amaral Coutinho, Y.
    Amor Dos Santos, S. P.
    Anderson, K. J.
    Arabidze, G.
    Araque, J. P.
    Artamonov, A.
    Asquith, L.
    Astalos, R.
    Mayes, J. Backus
    Bartos, P.
    Batkova, L.
    Bertolucci, F.
    Bessidskaia Bylund, Olga
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Blanco Castro, A.
    Blazek, T.
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Boumediene, D.
    Boveia, A.
    Brown, H.
    Busato, E.
    Calkins, R.
    Calvet, D.
    Calvet, S.
    Toro, R. Camacho
    Caminal Armadans, R.
    Carli, T.
    Carvalho, J.
    Cascella, M.
    Castro, N. F.
    Cavasinni, V.
    Cerqueira, A. S.
    Chadelas, R.
    Chakraborty, D.
    Chekanov, S.
    Chen, X.
    Chikovani, L.
    Choudalakis, G.
    Cinca, D.
    Ciubancan, M.
    Clément, Christophe
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Cole, S.
    Constantinescu, S.
    Costin, T.
    Crouau, M.
    Crozatier, C.
    Cuciuc, C. -M.
    Da Cunha Sargedas De Sousa, M. J.
    Darmora, S.
    Davidek, T.
    Del Prete, T.
    Dita, S.
    Djobava, T.
    Dolejsi, J.
    Dotti, A.
    Dubreuil, E.
    Dunford, M.
    Eriksson, Daniel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Errede, S.
    Errede, D.
    Faltova, J.
    Farbin, A.
    Febbraro, R.
    Federic, P.
    Feng, E. J.
    Ferrer, A.
    Fiascaris, M.
    Fiolhais, M. C. N.
    Fiorini, L.
    Francavilla, P.
    Torregrosa, E. Fullana
    Galhardo, B.
    Gellerstedt, Karl
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Ghodbane, N.
    Giakoumopoulou, V.
    Giangiobbe, V.
    Giokaris, N.
    Glonti, G. L.
    Gomes, A.
    Gonzalez Parra, G.
    Grenier, P.
    Grinstein, S.
    Gris, Ph.
    Guicheney, C.
    Hakobyan, H.
    Hard, A. S.
    Harkusha, S.
    Heelan, L.
    Helsens, C.
    Correia, A. M. Henriques
    Hernandez Jimenez, Y.
    Hernandez, C. M.
    Hign-Rodriguez, E.
    Hurwitz, M.
    Huseynov, N.
    Huston, J.
    Plante, I. Jen-La
    Jennens, D.
    Johansson, K. Erik
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Jon-And, Kerstin
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Jorge, P. M.
    Juste Rozas, A.
    Kapliy, A.
    Karpov, S. N.
    Karyukhin, A. N.
    Khandanyan, Hovhannes
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Khramov, E.
    Khubua, J.
    Kim, Hyeon
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Klimek, Pawel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Korolkov, I.
    Kruse, A.
    Kulchitsky, Y.
    Kurochkin, Y. A.
    Lafarguette, P.
    Lambert, D.
    LeCompte, T.
    Leitner, R.
    Leone, S.
    Liao, H.
    Lie, K.
    Lokajicek, M.
    Lundberg, Olof
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Magalhaes Martins, P. J.
    Maio, A.
    Makouski, M.
    Maneira, J.
    Manhaes de Andrade Filho, L.
    Manousakis-Katsikakis, A.
    Martin, B.
    Mchedlidze, G.
    Meehan, S.
    Garcia, B. R. Mellado
    Meoni, E.
    Merritt, F. S.
    Meyer, C.
    Miller, D. W.
    Milstead, David A.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Minashvili, I. A.
    Mir, L. M.
    Molander, Simon
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Montejo Berlingen, J.
    Mosidze, M.
    Myagkov, A. G.
    Nemecek, S.
    Nepomuceno, A. A.
    Nguyen, D. H.
    Nikolaenko, V.
    Nilsson, P.
    Nodulman, L.
    Nordkvist, Björn
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Ohm, C. C.
    Olariu, A.
    Oleiro Seabra, L. F.
    Onofre, A.
    Oreglia, M. J.
    Pallin, D.
    Pantea, D.
    Hernandez, D. Paredes
    Morales, M. I. Pedraza
    Pedro, R.
    Martins, F. M. Pedro
    Peng, H.
    Penning, B.
    Pilcher, J. E.
    Pina, J.
    Pleskot, V.
    Plotnikova, E.
    Podlyski, F.
    Popeneciu, G. A.
    Poveda, J.
    Pravahan, R.
    Pribyl, L.
    Price, L. E.
    Proudfoot, J.
    Rocha de Lima, J. G.
    Roda, C.
    Dos Santos, D. Roda
    Saez, S. M. Romano
    Rossetti, V.
    Ruiz-Martinez, A.
    Rusakovich, N. A.
    Ferrando, B. M. Salvachua
    Santoni, C.
    Santos, H.
    Saraiva, J. G.
    Says, L. P.
    Schwartzman, A.
    Scuri, F.
    Shimizu, S.
    Silva, J.
    Silverstein, Samuel B.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Solans, C. A.
    Solodkov, A. A.
    Solovyanov, O. V.
    Spalla, M.
    Stanek, R. W.
    Starchenko, E. A.
    Starovoitov, P.
    Stavina, P.
    Stoicea, G.
    Succurro, A.
    Suhr, C.
    Sumida, T.
    Sykora, I.
    Tas, P.
    Tavares Delgado, A.
    Tokar, S.
    Tsiareshka, P. V.
    Tsiskaridze, V.
    Tudorache, V.
    Tudorache, A.
    Tuggle, J. M.
    Tylmad, Maja
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Usai, G.
    Valero, A.
    Valery, L.
    Valladolid Gallego, E.
    Valls Ferrer, J. A.
    Vazeille, F.
    Veloso, F.
    Vichou, I.
    Vinogradov, V. B.
    Viret, S.
    Volpi, M.
    Wang, C.
    Weng, Z.
    White, A.
    Wilkens, H. G.
    Yanush, S.
    Yoshida, R.
    Zhang, L.
    Zhu, Y.
    Zinonos, Z.
    Zutshi, V.
    Zenis, T.
    van Woerden, M. C.
    The Laser calibration of the ATLAS Tile Calorimeter during the LHC run 12016In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 11, article id T10005Article in journal (Refereed)
    Abstract [en]

    This article describes the Laser calibration system of the ATLAS hadronic Tile Calorimeter that has been used during the run 1 of the LHC. First, the stability of the system associated readout electronics is studied. It is found to be stable with variations smaller than 0.6 %. Then, the method developed to compute the calibration constants, to correct for the variations of the gain of the calorimeter photomultipliers, is described. These constants were determined with a statistical uncertainty of 0.3 % and a systematic uncertainty of 0.2 % for the central part of the calorimeter and 0.5 % for the end-caps. Finally, the detection and correction of timing mis-configuration of the Tile Calorimeter using the Laser system are also presented.

  • 39. Abdel-Aty, M.
    et al.
    Larson, Jonas
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Nordic Institute for Theoretical Physics (Nordita).
    Eleuch, H.
    Obada, A. S. F.
    Multi-particle entanglement of charge qubits coupled to a nanoresonator2011In: Physica. E, Low-Dimensional systems and nanostructures, ISSN 1386-9477, E-ISSN 1873-1759, Vol. 43, no 9, p. 1625-1630Article in journal (Refereed)
    Abstract [en]

    The dynamics of charge qubits coupled to a nanomechanical resonator under the influence of both a phonon bath in contact with the resonator and irreversible decay of the qubits is considered. The focus of our analysis is devoted to multi-particle entanglement and the effects arising from the coupling to the reservoir. Even in the presence of the reservoirs, the inherent entanglement is found to be rather robust. Due to this fact, together with control of system parameters, the system may, therefore, be especially suited for quantum information processing. Our findings also shed light on the evolution of open quantum many-body systems. For instance, due to intrinsic qubit-qubit couplings our model is related to a driven XY spin model.

  • 40. Abdesselam, A.
    et al.
    Belyaev, A.
    Kuutmann, E. Bergeaas
    Bitenc, U.
    Brooijmans, G.
    Butterworth, J.
    de Renstrom, P. Bruckman
    Franzosi, D. Buarque
    Buckingham, R.
    Chapleau, B.
    Dasgupta, M.
    Davison, A.
    Dolen, J.
    Ellis, S.
    Fassi, F.
    Ferrando, J.
    Frandsen, M. T.
    Frost, J.
    Gadfort, T.
    Glover, N.
    Haas, A.
    Halkiadakis, E.
    Hamilton, K.
    Hays, C.
    Hill, C.
    Jackson, J.
    Issever, C.
    Karagoz, M.
    Katz, A.
    Kreczko, L.
    Krohn, D.
    Lewis, A.
    Livermore, S.
    Loch, P.
    Maksimovic, P.
    March-Russell, J.
    Martin, A.
    McCubbin, N.
    Newbold, D.
    Ott, J.
    Perez, G.
    Policchio, A.
    Rappoccio, S.
    Raklev, A. R.
    Richardson, P.
    Salam, G. P.
    Sannino, F.
    Santiago, J.
    Schwartzman, A.
    Shepherd-Themistocleous, C.
    Sinervo, P.
    Sjölin, Jörgen
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Son, M.
    Spannowsky, M.
    Strauss, E.
    Takeuchi, M.
    Tseng, J.
    Tweedie, B.
    Vermilion, C.
    Voigt, J.
    Vos, M.
    Wacker, J.
    Wagner-Kuhr, J.
    Wilson, M. G.
    Boosted objects: a probe of beyond the standard model physics2011In: European Physical Journal C, ISSN 1434-6044, E-ISSN 1434-6052, Vol. 71, no 6, p. 1661-Article in journal (Refereed)
    Abstract [en]

    We present the report of the hadronic working group of the BOOST2010 workshop held at the University of Oxford in June 2010. The first part contains a review of the potential of hadronic decays of highly boosted particles as an aid for discovery at the LHC and a discussion of the status of tools developed to meet the challenge of reconstructing and isolating these topologies. In the second part, we present new results comparing the performance of jet grooming techniques and top tagging algorithms on a common set of benchmark channels. We also study the sensitivity of jet substructure observables to the uncertainties in Monte Carlo predictions.

  • 41. Abdo, A. A.
    et al.
    Ackermann, M.
    Ajello, M.
    Allafort, A.
    Amin, M. A.
    Baldini, L.
    Barbiellini, G.
    Bastieri, D.
    Bechtol, K.
    Bellazzini, R.
    Blandford, R. D.
    Bonamente, E.
    Borgland, A. W.
    Bregeon, J.
    Brigida, M.
    Buehler, R.
    Bulmash, D.
    Buson, S.
    Caliandro, G. A.
    Cameron, R. A.
    Caraveo, P. A.
    Cavazzuti, E.
    Cecchi, C.
    Charles, E.
    Cheung, C. C.
    Chiang, J.
    Chiaro, G.
    Ciprini, S.
    Claus, R.
    Cohen-Tanugi, J.
    Conrad, Jan
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC). The Royal Swedish Academy of Sciences, Sweden.
    Corbet, R. H. D.
    Cutini, S.
    D'Ammando, F.
    de Angelis, A.
    de Palma, F.
    Dermer, C. D.
    Drell, P. S.
    Drlica-Wagner, A.
    Favuzzi, C.
    Finke, J.
    Focke, W. B.
    Fukazawa, Y.
    Fusco, P.
    Gargano, F.
    Gasparrini, D.
    Gehrels, N.
    Giglietto, N.
    Giordano, F.
    Giroletti, M.
    Glanzman, T.
    Grenier, I. A.
    Grove, J. E.
    Guiriec, S.
    Hadasch, D.
    Hayashida, M.
    Hays, E.
    Hughes, R. E.
    Inoue, Y.
    Jackson, M. S.
    Jogler, T.
    Johannesson, G.
    Johnson, A. S.
    Kamae, T.
    Knoedlseder, J.
    Kuss, M.
    Lande, J.
    Larsson, Stefan
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, Department of Astronomy. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Latronico, L.
    Longo, F.
    Loparco, F.
    Lott, B.
    Lovellette, M. N.
    Lubrano, P.
    Madejski, G. M.
    Mazziotta, M. N.
    Mehault, J.
    Michelson, P. F.
    Mizuno, T.
    Monzani, M. E.
    Morselli, A.
    Moskalenko, I. V.
    Murgia, S.
    Nemmen, R.
    Nuss, E.
    Ohno, M.
    Ohsugi, T.
    Paneque, D.
    Perkins, J. S.
    Pesce-Rollins, M.
    Piron, F.
    Pivato, G.
    Porter, T. A.
    Raino, S.
    Rando, R.
    Razzano, M.
    Reimer, A.
    Reimer, O.
    Reyes, L. C.
    Ritz, S.
    Romoli, C.
    Roth, M.
    Parkinson, P. M. Saz
    Sgro, C.
    Siskind, E. J.
    Spandre, G.
    Spinelli, P.
    Takahashi, H.
    Takeuchi, Y.
    Tanaka, T.
    Thayer, J. G.
    Thayer, J. B.
    Thompson, D. J.
    Tibaldo, L.
    Tinivella, M.
    Torres, D. F.
    Tosti, G.
    Troja, E.
    Tronconi, V.
    Usher, T. L.
    Vandenbroucke, J.
    Vasileiou, V.
    Vianello, G.
    Vitale, V.
    Waite, A. P.
    Werner, M.
    Winer, B. L.
    Wood, K. S.
    GAMMA-RAY FLARING ACTIVITY FROM THE GRAVITATIONALLY LENSED BLAZAR PKS 1830-211 OBSERVED BY Fermi LAT2015In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 799, no 2, article id 143Article in journal (Refereed)
    Abstract [en]

    The Large Area Telescope ( LAT) on board the FermiGamma- ray Space Telescope routinely detects the MeV- peaked flat- spectrum radio quasar PKS 1830- 211 ( z = 2.507). Its apparent isotropic. - ray luminosity ( E > 100 MeV), averaged over 3 years of observations and peaking on 2010 October 14/ 15 at 2.9 x 1050 erg s- 1, makes it among the brightest high- redshift Fermi blazars. No published model with a single lens can account for all of the observed characteristics of this complex system. Based on radio observations, one expects time- delayed variability to follow about 25 days after a primary flare, with flux about a factor of 1.5 less. Two large. - ray flares of PKS 1830- 211 have been detected by the LAT in the considered period, and no substantial evidence for such a delayed activity was found. This allows us to place a lower limit of about 6 on the. - ray flux ratio between the two lensed images. Swift XRT observations from a dedicated Target of Opportunity program indicate a hard spectrum with no significant correlation of X- ray flux with the. - ray variability. The spectral energy distribution can be modeled with inverse Compton scattering of thermal photons from the dusty torus. The implications of the LAT data in terms of variability, the lack of evident delayed flare events, and different radio and. - ray flux ratios are discussed. Microlensing effects, absorption, size and location of the emitting regions, the complex mass distribution of the system, an energy- dependent inner structure of the source, and flux suppression by the lens galaxy for one image path may be considered as hypotheses for understanding our results.

  • 42. Abdo, A. A.
    et al.
    Ackermann, M.
    Ajello, M.
    Allafort, A.
    Asano, K.
    Baldini, L.
    Ballet, J.
    Barbiellini, G.
    Baring, M. G.
    Bastieri, D.
    Bechtol, K.
    Bellazzini, R.
    Berenji, B.
    Blandford, R. D.
    Bloom, E. D.
    Bonamente, E.
    Borgland, A. W.
    Bregeon, J.
    Brez, A.
    Brigida, M.
    Bruel, P.
    Buson, S.
    Caliandro, G. A.
    Cameron, R. A.
    Camilo, F.
    Caraveo, P. A.
    Carrigan, S.
    Casandjian, J. M.
    Cecchi, C.
    Celik, Oe
    Chekhtman, A.
    Cheung, C. C.
    Chiang, J.
    Ciprini, S.
    Claus, R.
    Cohen-Tanugi, J.
    Conrad, Jan
    Stockholm University, Faculty of Science, Department of Physics.
    den Hartog, P. R.
    Dermer, C. D.
    de Luca, A.
    de Palma, F.
    Dormody, M.
    do Couto e Silva, E.
    Drell, P. S.
    Dubois, R.
    Dumora, D.
    Farnier, C.
    Favuzzi, C.
    Fegan, S. J.
    Ferrara, E. C.
    Focke, W. B.
    Frailis, M.
    Fukazawa, Y.
    Funk, S.
    Fusco, P.
    Gargano, F.
    Gehrels, N.
    Germani, S.
    Giglietto, N.
    Giordano, F.
    Glanzman, T.
    Godfrey, G.
    Gotthelf, E. V.
    Grenier, I. A.
    Grondin, M. -H
    Grove, J. E.
    Guillemot, L.
    Guiriec, S.
    Hanabata, Y.
    Harding, A. K.
    Hays, E.
    Hobbs, G.
    Horan, D.
    Hughes, R. E.
    Johannesson, G.
    Johnson, A. S.
    Johnson, T. J.
    Johnson, W. N.
    Johnston, S.
    Kamae, T.
    Kanai, Y.
    Kanbach, G.
    Katagiri, H.
    Kataoka, J.
    Kawai, N.
    Keith, M.
    Kerr, M.
    Knoedlseder, J.
    Kuss, M.
    Lande, J.
    Latronico, L.
    Lemoine-Goumard, M.
    Garde, Maja Llena
    Stockholm University, Faculty of Science, Department of Physics.
    Longo, F.
    Loparco, F.
    Lott, B.
    Lovellette, M. N.
    Lubrano, P.
    Makeev, A.
    Manchester, R. N.
    Marelli, M.
    Mazziotta, M. N.
    McEnery, J. E.
    Michelson, P. F.
    Mitthumsiri, W.
    Mizuno, T.
    Moiseev, A. A.
    Monte, C.
    Monzani, M. E.
    Morselli, A.
    Moskalenko, I. V.
    Murgia, S.
    Nakamori, T.
    Nolan, P. L.
    Norris, J. P.
    Nuss, E.
    Ohno, M.
    Ohsugi, T.
    Omodei, N.
    Orlando, E.
    Ormes, J. F.
    Paneque, D.
    Panetta, J. H.
    Parent, D.
    Pelassa, V.
    Pepe, M.
    Pesce-Rollins, M.
    Piron, F.
    Porter, T. A.
    Raino, S.
    Rando, R.
    Razzano, M.
    Rea, N.
    Reimer, A.
    Reimer, O.
    Reposeur, T.
    Rodriguez, A. Y.
    Romani, R. W.
    Roth, M.
    Ryde, F.
    Sadrozinski, H. F. -W
    Sander, A.
    Parkinson, P. M. Saz
    Sgro, C.
    Siskind, E. J.
    Smith, D. A.
    Smith, P. D.
    Spandre, G.
    Spinelli, P.
    Starck, J. -L
    Strickman, M. S.
    Suson, D. J.
    Takahashi, H.
    Takahashi, T.
    Tanaka, T.
    Thayer, J. B.
    Thayer, J. G.
    Thompson, D. J.
    Thorsett, S. E.
    Tibaldo, L.
    Torres, D. F.
    Tosti, G.
    Tramacere, A.
    Uchiyama, Y.
    Usher, T. L.
    Vasileiou, V.
    Venter, C.
    Vilchez, N.
    Vitale, V.
    Waite, A. P.
    Wang, P.
    Weltevrede, P.
    Winer, B. L.
    Wood, K. S.
    Yang, Zhaoyu
    Stockholm University, Faculty of Science, Department of Physics.
    Ylinen, T.
    Ziegler, M.
    DETECTION OF THE ENERGETIC PULSAR PSR B1509-58 AND ITS PULSAR WIND NEBULA IN MSH 15-52 USING THE FERMI-LARGE AREA TELESCOPE2010In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 714, no 1, p. 927-936Article in journal (Refereed)
    Abstract [en]

    We report the detection of high-energy gamma-ray emission from the young and energetic pulsar PSR B1509-58 and its pulsar wind nebula (PWN) in the composite supernova remnant G320.4-1.2 (aka MSH 15-52). Using 1 yr of survey data with the Fermi-Large Area Telescope (LAT), we detected pulsations from PSR B1509-58 up to 1 GeV and extended gamma-ray emission above 1 GeV spatially coincident with the PWN. The pulsar light curve presents two peaks offset from the radio peak by phases 0.96 +/- 0.01 and 0.33 +/- 0.02. New constraining upper limits on the pulsar emission are derived below 1 GeV and confirm a severe spectral break at a few tens of MeV. The nebular spectrum in the 1-100 GeV energy range is well described by a power law with a spectral index of (1.57 +/- 0.17 +/- 0.13) and a flux above 1 GeV of (2.91 +/- 0.79 +/- 1.35) x 10(-9) cm(-2) s(-1). The first errors represent the statistical errors on the fit parameters, while the second ones are the systematic uncertainties. The LAT spectrum of the nebula connects nicely with Cherenkov observations, and indicates a spectral break between GeV and TeV energies.

  • 43. Abdo, A. A.
    et al.
    Ackermann, M.
    Ajello, M.
    Allafort, A.
    Baldini, L.
    Ballet, J.
    Barbiellini, G.
    Baring, M. G.
    Bastieri, D.
    Baughman, B. M.
    Bechtol, K.
    Bellazzini, R.
    Berenji, B.
    Blandford, R. D.
    Bloom, E. D.
    Bonamente, E.
    Borgland, A. W.
    Bregeon, J.
    Brez, A.
    Brigida, M.
    Bruel, P.
    Buehler, R.
    Burnett, T. H.
    Busetto, G.
    Caliandro, G. A.
    Cameron, R. A.
    Caraveo, P. A.
    Casandjian, J. M.
    Cecchi, C.
    Celik, Oe.
    Charles, E.
    Chaty, S.
    Chekhtman, A.
    Cheung, C. C.
    Chiang, J.
    Cillis, A. N.
    Ciprini, S.
    Claus, R.
    Cohen-Tanugi, J.
    Conrad, Jan
    Stockholm University, Faculty of Science, Department of Physics.
    Corbel, S.
    de Palma, F.
    Digel, S. W.
    Dormody, M.
    do Couto e Silva, E.
    Drell, P. S.
    Dubois, R.
    Dumora, D.
    Edmonds, Y.
    Farnier, C.
    Favuzzi, C.
    Fegan, S. J.
    Ferrara, E. C.
    Focke, W. B.
    Fortin, P.
    Frailis, M.
    Fukazawa, Y.
    Funk, S.
    Fusco, P.
    Gargano, F.
    Gasparrini, D.
    Gehrels, N.
    Germani, S.
    Giavitto, G.
    Giglietto, N.
    Giordano, F.
    Glanzman, T.
    Godfrey, G.
    Grenier, I. A.
    Grondin, M. -H
    Grove, J. E.
    Guillemot, L.
    Guiriec, S.
    Hanabata, Y.
    Hays, E.
    Harding, A. K.
    Hayashida, M.
    Horan, D.
    Hughes, R. E.
    Jackson, M. S.
    Johnson, A. S.
    Johnson, T. J.
    Johnson, W. N.
    Kamae, T.
    Katagiri, H.
    Kataoka, J.
    Kawai, N.
    Kerr, M.
    Knoedlseder, J.
    Kuss, M.
    Lande, J.
    Latronico, L.
    Lemoine-Goumard, M.
    Longo, F.
    Loparco, F.
    Lott, B.
    Lovellette, M. N.
    Lubrano, P.
    Makeev, A.
    Mazziotta, M. N.
    Meurer, C.
    Stockholm University, Faculty of Science, Department of Physics.
    Michelson, P. F.
    Mitthumsiri, W.
    Mizuno, T.
    Monte, C.
    Monzani, M. E.
    Morselli, A.
    Moskalenko, I. V.
    Murgia, S.
    Nakamori, T.
    Nolan, P. L.
    Norris, J. P.
    Nuss, E.
    Ohsugi, T.
    Okumura, A.
    Omodei, N.
    Orlando, E.
    Ormes, J. F.
    Paneque, D.
    Panetta, J. H.
    Pelassa, V.
    Pepe, M.
    Pesce-Rollins, M.
    Piron, F.
    Pohl, M.
    Porter, T. A.
    Raino, S.
    Rando, R.
    Reimer, A.
    Reimer, O.
    Reposeur, T.
    Ritz, S.
    Rodriguez, A. Y.
    Romani, R. W.
    Roth, M.
    Sadrozinski, H. F. -W
    Sander, A.
    Parkinson, P. M. Saz
    Scargle, J. D.
    Sgro, C.
    Siskind, E. J.
    Smith, D. A.
    Smith, P. D.
    Spinelli, P.
    Strickman, M. S.
    Suson, D. J.
    Tajima, H.
    Takahashi, T.
    Tanaka, T.
    Thayer, J. B.
    Thayer, J. G.
    Thompson, D. J.
    Thorsett, S. E.
    Tibaldo, L.
    Tibolla, O.
    Torres, D. F.
    Tosti, G.
    Tramacere, A.
    Uchiyama, Y.
    Usher, T. L.
    Van Etten, A.
    Vasileiou, V.
    Venter, C.
    Vilchez, N.
    Vitale, V.
    Waite, A. P.
    Wang, P.
    Winer, B. L.
    Wood, K. S.
    Yamazaki, R.
    Ylinen, T.
    Ziegler, M.
    FERMI-LAT DISCOVERY OF GeV GAMMA-RAY EMISSION FROM THE YOUNG SUPERNOVA REMNANT CASSIOPEIA A2010In: The Astrophysical Journal Letters, ISSN 0004-6388, Vol. 710, no 1, p. l92-L97Article in journal (Refereed)
    Abstract [en]

    We report on the first detection of GeV high-energy gamma-ray emission from a young supernova remnant (SNR) with the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope. These observations reveal a source with no discernible spatial extension detected at a significance level of 12.2 sigma above 500 MeV a a location that is consistent with the position of the remnant of the supernova explosion that occurred around 1680 in the Cassiopeia constellation-Cassiopeia A (Cas A). The gamma-ray flux and spectral shape of the source are consistent with a scenario in which the gamma-ray emission originates from relativistic particles accelerated in the shell of this remnant. The total content of cosmic rays (electrons and protons) accelerated in Cas A can be estimated as W-CR similar or equal to (1-4) x 10(49) erg thanks to the well-known density in the remnant assuming that the observed gamma ray originates in the SNR shell(s). The magnetic field in the radio-emitting plasma can be robustly constrained as B >= 0.1 mG, providing new evidence of the magnetic field amplification at the forward shock and the strong field in the shocked ejecta.

  • 44. Abdo, A. A.
    et al.
    Ackermann, M.
    Ajello, M.
    Allafort, A.
    Baldini, L.
    Ballet, J.
    Barbiellini, G.
    Baring, M. G.
    Bastieri, D.
    Bellazzini, R.
    Berenji, B.
    Blandford, R. D.
    Bloom, E. D.
    Bonamente, E.
    Borgland, A. W.
    Bouvier, A.
    Brandt, T. J.
    Bregeon, J.
    Brigida, M.
    Bruel, P.
    Buehler, R.
    Buson, S.
    Caliandro, G. A.
    Cameron, R. A.
    Caraveo, P. A.
    Casandjian, J. M.
    Cecchi, C.
    Chaty, S.
    Chekhtman, A.
    Cheung, C. C.
    Chiang, J.
    Cillis, A. N.
    Ciprini, S.
    Claus, R.
    Cohen-Tanugi, J.
    Conrad, Jan
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Corbel, S.
    Cutini, S.
    de Angelis, A.
    de Palma, F.
    Dermer, C. D.
    Digel, S. W.
    do Couto e Silva, E.
    Drell, P. S.
    Drlica-Wagner, A.
    Dubois, R.
    Dumora, D.
    Favuzzi, C.
    Ferrara, E. C.
    Fortin, P.
    Frailis, M.
    Fukazawa, Y.
    Fukui, Y.
    Funk, S.
    Fusco, P.
    Gargano, F.
    Gasparrini, D.
    Gehrels, N.
    Germani, S.
    Giglietto, N.
    Giordano, F.
    Giroletti, M.
    Glanzman, T.
    Godfrey, G.
    Grenier, I. A.
    Grondin, M. -H
    Guiriec, S.
    Hadasch, D.
    Hanabata, Y.
    Harding, A. K.
    Hayashida, M.
    Hayashi, K.
    Hays, E.
    Horan, D.
    Jackson, M. S.
    Johannesson, G.
    Johnson, A. S.
    Kamae, T.
    Katagiri, H.
    Kataoka, J.
    Kerr, M.
    Knoedlseder, J.
    Kuss, M.
    Lande, J.
    Latronico, L.
    Lee, S. -H
    Lemoine-Goumard, M.
    Longo, F.
    Loparco, F.
    Lovellette, M. N.
    Lubrano, P.
    Madejski, G. M.
    Makeev, A.
    Mazziotta, M. N.
    McEnery, J. E.
    Michelson, P. F.
    Mignani, R. P.
    Mitthumsiri, W.
    Mizuno, T.
    Moiseev, A. A.
    Monte, C.
    Monzani, M. E.
    Morselli, A.
    Moskalenko, I. V.
    Murgia, S.
    Naumann-Godo, M.
    Nolan, P. L.
    Norris, J. P.
    Nuss, E.
    Ohsugi, T.
    Okumura, A.
    Orlando, E.
    Ormes, J. F.
    Paneque, D.
    Parent, D.
    Pelassa, V.
    Pesce-Rollins, M.
    Pierbattista, M.
    Piron, F.
    Pohl, M.
    Porter, T. A.
    Raino, S.
    Rando, R.
    Razzano, M.
    Reimer, O.
    Reposeur, T.
    Ritz, S.
    Romani, R. W.
    Roth, M.
    Sadrozinski, H. F. -W
    Parkinson, P. M. Saz
    Sgro, C.
    Smith, D. A.
    Smith, P. D.
    Spandre, G.
    Spinelli, P.
    Strickman, M. S.
    Tajima, H.
    Takahashi, H.
    Takahashi, T.
    Tanaka, T.
    Thayer, J. G.
    Thayer, J. B.
    Thompson, D. J.
    Tibaldo, L.
    Tibolla, O.
    Torres, D. F.
    Tosti, G.
    Tramacere, A.
    Troja, E.
    Uchiyama, Y.
    Vandenbroucke, J.
    Vasileiou, V.
    Vianello, G.
    Vilchez, N.
    Vitale, V.
    Waite, A. P.
    Wang, P.
    Winer, B. L.
    Wood, K. S.
    Yamamoto, H.
    Yamazaki, R.
    Yang, Zhaoyu
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Ziegler, M.
    OBSERVATIONS OF THE YOUNG SUPERNOVA REMNANT RX J1713.7-3946 WITH THE FERMI LARGE AREA TELESCOPE2011In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 734, no 1, p. 28-Article in journal (Refereed)
    Abstract [en]

    We present observations of the young supernova remnant (SNR) RX J1713.7-3946 with the Fermi Large Area Telescope (LAT). We clearly detect a source positionally coincident with the SNR. The source is extended with a best-fit extension of 0 degrees.55 +/- 0 degrees.04 matching the size of the non-thermal X-ray and TeV gamma-ray emission from the remnant. The positional coincidence and the matching extended emission allow us to identify the LAT source with SNR RX J1713.7-3946. The spectrum of the source can be described by a very hard power law with a photon index of Gamma = 1.5 +/- 0.1 that coincides in normalization with the steeper H. E. S. S.-detected gamma-ray spectrum at higher energies. The broadband gamma-ray emission is consistent with a leptonic origin as the dominant mechanism for the gamma-ray emission.

  • 45. Abdo, A. A.
    et al.
    Ackermann, M.
    Ajello, M.
    Allafort, A.
    Baldini, L.
    Ballet, J.
    Barbiellini, G.
    Bastieri, D.
    Bechtol, K.
    Bellazzini, R.
    Berenji, B.
    Blandford, R. D.
    Bloom, E. D.
    Bonamente, E.
    Borgland, A. W.
    Bouvier, A.
    Brandt, T. J.
    Bregeon, J.
    Brez, A.
    Brigida, M.
    Bruel, P.
    Buehler, R.
    Buson, S.
    Caliandro, G. A.
    Cameron, R. A.
    Cannon, A.
    Caraveo, P. A.
    Casandjian, J. M.
    Celik, O.
    Charles, E.
    Chekhtman, A.
    Cheung, C. C.
    Chiang, J.
    Ciprini, S.
    Claus, R.
    Cohen-Tanugi, J.
    Costamante, L.
    Cutini, S.
    D'Ammando, F.
    Dermer, C. D.
    de Angelis, A.
    de Luca, A.
    de Palma, F.
    Digel, S. W.
    do Couto e Silva, E.
    Drell, P. S.
    Drlica-Wagner, A.
    Dubois, R.
    Dumora, D.
    Favuzzi, C.
    Fegan, S. J.
    Ferrara, E. C.
    Focke, W. B.
    Fortin, P.
    Frailis, M.
    Fukazawa, Y.
    Funk, S.
    Fusco, P.
    Gargano, F.
    Gasparrini, D.
    Gehrels, N.
    Germani, S.
    Giglietto, N.
    Giordano, F.
    Giroletti, M.
    Glanzman, T.
    Godfrey, G.
    Grenier, I. A.
    Grondin, M. -H
    Grove, J. E.
    Guiriec, S.
    Hadasch, D.
    Hanabata, Y.
    Harding, A. K.
    Hayashi, K.
    Hayashida, M.
    Hays, E.
    Horan, D.
    Itoh, R.
    Johannesson, G.
    Johnson, A. S.
    Johnson, T. J.
    Khangulyan, D.
    Kamae, T.
    Katagiri, H.
    Kataoka, J.
    Kerr, M.
    Knoedlseder, J.
    Kuss, M.
    Lande, J.
    Latronico, L.
    Lee, S. -H
    Lemoine-Goumard, M.
    Longo, F.
    Loparco, F.
    Lubrano, P.
    Madejski, G. M.
    Makeev, A.
    Marelli, M.
    Mazziotta, M. N.
    McEnery, J. E.
    Michelson, P. F.
    Mitthumsiri, W.
    Mizuno, T.
    Moiseev, A. A.
    Monte, C.
    Monzani, M. E.
    Morselli, A.
    Moskalenko, I. V.
    Murgia, S.
    Nakamori, T.
    Naumann-Godo, M.
    Nolan, P. L.
    Norris, J. P.
    Nuss, E.
    Ohsugi, T.
    Okumura, A.
    Omodei, N.
    Ormes, J. F.
    Ozaki, M.
    Paneque, D.
    Parent, D.
    Pelassa, V.
    Pepe, M.
    Pesce-Rollins, M.
    Pierbattista, M.
    Piron, F.
    Porter, T. A.
    Raino, S.
    Rando, R.
    Ray, P. S.
    Razzano, M.
    Reimer, A.
    Reimer, O.
    Reposeur, T.
    Ritz, S.
    Romani, R. W.
    Sadrozinski, H. F. -W
    Sanchez, D.
    Parkinson, P. M. Saz
    Scargle, J. D.
    Schalk, T. L.
    Sgro, C.
    Siskind, E. J.
    Smith, P. D.
    Spandre, G.
    Spinelli, P.
    Strickman, M. S.
    Suson, D. J.
    Takahashi, H.
    Takahashi, T.
    Tanaka, T.
    Thayer, J. B.
    Thompson, D. J.
    Tibaldo, L.
    Torres, D. F.
    Tosti, G.
    Tramacere, A.
    Troja, E.
    Uchiyama, Y.
    Vandenbroucke, J.
    Vasileiou, V.
    Vianello, G.
    Vitale, V.
    Wang, P.
    Wood, K. S.
    Yang, Zhaoyu
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Ziegler, M.
    Gamma-Ray Flares from the Crab Nebula2011In: Science, ISSN 0036-8075, E-ISSN 1095-9203, Vol. 331, no 6018, p. 739-742Article in journal (Refereed)
    Abstract [en]

    A young and energetic pulsar powers the well-known Crab Nebula. Here, we describe two separate gamma-ray (photon energy greater than 100 mega-electron volts) flares from this source detected by the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. The first flare occurred in February 2009 and lasted approximately 16 days. The second flare was detected in September 2010 and lasted approximately 4 days. During these outbursts, the gamma-ray flux from the nebula increased by factors of four and six, respectively. The brevity of the flares implies that the gamma rays were emitted via synchrotron radiation from peta-electron-volt (10(15) electron volts) electrons in a region smaller than 1.4 x 10(-2) parsecs. These are the highest-energy particles that can be associated with a discrete astronomical source, and they pose challenges to particle acceleration theory.

  • 46. Abdo, A. A.
    et al.
    Ackermann, M.
    Ajello, M.
    Allafort, A.
    Baldini, L.
    Ballet, J.
    Barbiellini, G.
    Bastieri, D.
    Bechtol, K.
    Bellazzini, R.
    Berenji, B.
    Blandford, R. D.
    Bloom, E. D.
    Bonamente, E.
    Borgland, A. W.
    Bouvier, A.
    Brandt, T. J.
    Bregeon, J.
    Brigida, M.
    Bruel, P.
    Buehler, R.
    Buson, S.
    Caliandro, G. A.
    Cameron, R. A.
    Caraveo, P. A.
    Carrigan, S.
    Casandjian, J. M.
    Cecchi, C.
    Celik, Oe.
    Chekhtman, A.
    Chiang, J.
    Ciprini, S.
    Claus, R.
    Cohen-Tanugi, J.
    Conrad, Jan
    Stockholm University, Faculty of Science, Department of Physics.
    Dermer, C. D.
    de Palma, F.
    do Couto e Silva, E.
    Drell, P. S.
    Dubois, R.
    Dumora, D.
    Farnier, C.
    Favuzzi, C.
    Fegan, S. J.
    Fukazawa, Y.
    Fukui, Y.
    Funk, S.
    Fusco, P.
    Gargano, F.
    Gehrels, N.
    Germani, S.
    Giglietto, N.
    Giordano, F.
    Glanzman, T.
    Godfrey, G.
    Grenier, I. A.
    Grove, J. E.
    Guiriec, S.
    Hadasch, D.
    Hanabata, Y.
    Harding, A. K.
    Hays, E.
    Horan, D.
    Hughes, R. E.
    Johannesson, G.
    Johnson, A. S.
    Johnson, W. N.
    Kamae, T.
    Katagiri, H.
    Kataoka, J.
    Knoedlseder, J.
    Kuss, M.
    Lande, J.
    Latronico, L.
    Lee, S. -H
    Lemoine-Goumard, M.
    Garde, Maja Llena
    Stockholm University, Faculty of Science, Department of Physics.
    Longo, F.
    Loparco, F.
    Lovellette, M. N.
    Lubrano, P.
    Makeev, A.
    Mazziotta, M. N.
    Michelson, P. F.
    Mitthumsiri, W.
    Mizuno, T.
    Moiseev, A. A.
    Monte, C.
    Monzani, M. E.
    Morselli, A.
    Moskalenko, I. V.
    Murgia, S.
    Nakamori, T.
    Nolan, P. L.
    Norris, J. P.
    Nuss, E.
    Ohno, M.
    Ohsugi, T.
    Omodei, N.
    Orlando, E.
    Ormes, J. F.
    Ozaki, M.
    Panetta, J. H.
    Parent, D.
    Pelassa, V.
    Pepe, M.
    Pesce-Rollins, M.
    Piron, F.
    Porter, T. A.
    Raino, S.
    Rando, R.
    Razzano, M.
    Reimer, A.
    Reimer, O.
    Reposeur, T.
    Rodriguez, Y.
    Roth, M.
    Sadrozinski, H. F. -W
    Sander, A.
    Parkinson, P. M. Saz
    Sgro, C.
    Siskind, E. J.
    Smith, D. A.
    Smith, P. D.
    Spandre, G.
    Spinelli, P.
    Strickman, M. S.
    Suson, D. J.
    Tajima, H.
    Takahashi, H.
    Takahashi, T.
    Tanaka, T.
    Thayer, J. B.
    Thayer, J. G.
    Thompson, D. J.
    Tibaldo, L.
    Tibolla, O.
    Torres, D. F.
    Tosti, G.
    Uchiyama, Y.
    Uehara, T.
    Usher, T. L.
    Vasileiou, V.
    Vilchez, N.
    Vitale, V.
    Waite, A. P.
    Wang, P.
    Winer, B. L.
    Wood, K. S.
    Yamamoto, H.
    Yamazaki, R.
    Yang, Zhaoyu
    Stockholm University, Faculty of Science, Department of Physics.
    Ylinen, T.
    Ziegler, M.
    FERMI LARGE AREA TELESCOPE OBSERVATIONS OF THE SUPERNOVA REMNANT W28 (G6.4-0.1)2010In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 718, no 1, p. 348-356Article in journal (Refereed)
    Abstract [en]

    We present detailed analysis of two gamma-ray sources, 1FGL J1801.3-2322c and 1FGL J1800.5-2359c, that have been found toward the supernova remnant (SNR) W28 with the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. 1FGL J1801.3-2322c is found to be an extended source within the boundary of SNR W28, and to extensively overlap with the TeV gamma-ray source HESS J1801-233, which is associated with a dense molecular cloud interacting with the SNR. The gamma-ray spectrum measured with the LAT from 0.2 to 100 GeV can be described by a broken power-law function with a break at similar to 1 GeV and photon indices of 2.09 +/- 0.08 (stat) +/- 0.28 (sys) below the break and 2.74 +/- 0.06 (stat) +/- 0.09 (sys) above the break. Given the clear association between HESS J1801-233 and the shocked molecular cloud and a smoothly connected spectrum in the GeV-TeV band, we consider the origin of the gamma-ray emission in both GeV and TeV ranges to be the interaction between particles accelerated in the SNR and the molecular cloud. The decay of neutral pions produced in interactions between accelerated hadrons and dense molecular gas provides a reasonable explanation for the broadband gamma-ray spectrum. 1FGL J1800.5-2359c, located outside the southern boundary of SNR W28, cannot be resolved. An upper limit on the size of the gamma-ray emission was estimated to be similar to 16' using events above similar to 2 GeV under the assumption of a circular shape with uniform surface brightness. It appears to coincide with the TeV source HESS J1800-240B, which is considered to be associated with a dense molecular cloud that contains the ultra compact H II region W28A2 (G5.89-0.39). We found no significant gamma-ray emission in the LAT energy band at the positions of TeV sources HESS J1800-230A and HESS J1800-230C. The LAT data for HESS J1800-230A combined with the TeV data points indicate a spectral break between 10 GeV and 100 GeV.

  • 47. Abdo, A. A.
    et al.
    Ackermann, M.
    Ajello, M.
    Allafort, A.
    Baldini, L.
    Ballet, J.
    Barbiellini, G.
    Bastieri, D.
    Bechtol, K.
    Bellazzini, R.
    Berenji, B.
    Blandford, R. D.
    Bloom, E. D.
    Bonamente, E.
    Borgland, A. W.
    Bouvier, A.
    Bregeon, J.
    Brez, A.
    Brigida, M.
    Bruel, P.
    Burnett, T. H.
    Buson, S.
    Caliandro, G. A.
    Cameron, R. A.
    Caraveo, P. A.
    Carrigan, S.
    Casandjian, J. M.
    Cecchi, C.
    Celik, Oe
    Chekhtman, A.
    Chung, C. C.
    Chiang, J.
    Ciprini, S.
    Claus, R.
    Cohen-Tanugi, J.
    Conrad, Jan
    Stockholm University, Faculty of Science, Department of Physics.
    de Angelis, A.
    de Palma, F.
    Dormody, M.
    do Couto e Silva, E.
    Drell, P. S.
    Dubois, R.
    Dumora, D.
    Farnier, C.
    Favuzzi, C.
    Fegan, S. J.
    Focke, W. B.
    Fortin, P.
    Frailis, M.
    Fukazawa, Y.
    Funk, S.
    Fusco, P.
    Gargano, F.
    Gehrels, N.
    Germani, S.
    Giavitto, G.
    Giglietto, N.
    Giordano, F.
    Glanzman, T.
    Godfrey, G.
    Grenier, I. A.
    Grondin, M. -H
    Grove, J. E.
    Guillemot, L.
    Guiriec, S.
    Harding, A. K.
    Hayashida, M.
    Hays, E.
    Horan, D.
    Hughes, R. E.
    Jackson, M. S.
    Johannesson, G.
    Johnson, A. S.
    Johnson, T. J.
    Johnson, W. N.
    Johnston, S.
    Kamae, T.
    Katagiri, H.
    Kataoka, J.
    Kawai, N.
    Kerr, M.
    Knoedlseder, J.
    Kuss, M.
    Lande, J.
    Latronico, L.
    Lee, S. -H
    Lemoine-Goumard, M.
    Garde, Maja Llena
    Stockholm University, Faculty of Science, Department of Physics.
    Longo, F.
    Loparco, F.
    Lott, B.
    Lovellette, M. N.
    Lubrano, P.
    Makeev, A.
    Marelli, M.
    Mazziotta, M. N.
    McEnery, J. E.
    Meurer, C.
    Stockholm University, Faculty of Science, Department of Physics.
    Michelson, P. F.
    Mitthumsiri, W.
    Mizuno, T.
    Moiseev, A. A.
    Monte, C.
    Monzani, M. E.
    Morselli, A.
    Moskalenko, I. V.
    Murgia, S.
    Nakamori, T.
    Nolan, P. L.
    Norris, J. P.
    Noutsos, A.
    Nuss, E.
    Ohsugi, T.
    Omodei, N.
    Orlando, E.
    Ormes, J. F.
    Ozaki, M.
    Paneque, D.
    Panetta, J. H.
    Parent, D.
    Pelassa, V.
    Pepe, M.
    Pesce-Rollins, M.
    Pierbattista, M.
    Piron, F.
    Porter, T. A.
    Raino, S.
    Rando, R.
    Ray, P. S.
    Rea, N.
    Reimer, A.
    Reimer, O.
    Reposeur, T.
    Ritz, S.
    Rodriguez, A. Y.
    Romani, R. W.
    Roth, M.
    Ryde, F.
    Sadrozinski, H. F. -W
    Sanchez, D.
    Sander, A.
    Parkinson, P. M. Saz
    Scargle, J. D.
    Sgro, C.
    Siskind, E. J.
    Smith, D. A.
    Smith, P. D.
    Spandre, G.
    Spinelli, P.
    Strickman, M. S.
    Suson, D. J.
    Tajima, H.
    Takahashi, H.
    Takahashi, T.
    Tanaka, T.
    Thayer, J. B.
    Thayer, J. G.
    Thompson, D. J.
    Tibaldo, L.
    Torres, D. F.
    Tosti, G.
    Tramacere, A.
    Uchiyama, Y.
    Usher, T. L.
    Van Etten, A.
    Vasileiou, V.
    Venter, C.
    Vilchez, N.
    Vitale, V.
    Waite, A. P.
    Wang, P.
    Weltevrede, P.
    Winer, B. L.
    Wood, K. S.
    Ylinen, T.
    Ziegler, M.
    FERMI LARGE AREA TELESCOPE OBSERVATIONS OF THE VELA-X PULSAR WIND NEBULA2010In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 713, no 1, p. 146-153Article in journal (Refereed)
    Abstract [en]

    We report on gamma-ray observations in the off-pulse window of the Vela pulsar PSR B0833-45 using 11 months of survey data from the Fermi Large Area Telescope (LAT). This pulsar is located in the 8 degrees diameter Vela supernova remnant, which contains several regions of non-thermal emission detected in the radio, X-ray, and gamma-ray bands. The gamma-ray emission detected by the LAT lies within one of these regions, the 2 degrees x 3 degrees area south of the pulsar known as Vela-X. The LAT flux is significantly spatially extended with a best-fit radius of 0.degrees 88 +/- 0.degrees 12 for an assumed radially symmetric uniform disk. The 200 MeV to 20 GeV LAT spectrum of this source is well described by a power law with a spectral index of 2.41 +/- 0.09 +/- 0.15 and integral flux above 100 MeV of (4.73 +/- 0.63 +/- 1.32) x 10(-7) cm(-2) s(-1). The first errors represent the statistical error on the fit parameters, while the second ones are the systematic uncertainties. Detailed morphological and spectral analyses give strong constraints on the energetics and magnetic field of the pulsar wind nebula system and favor a scenario with two distinct electron populations.

  • 48. Abdo, A. A.
    et al.
    Ackermann, M.
    Ajello, M.
    Allafort, A.
    Baldini, L.
    Ballet, J.
    Barbiellini, G.
    Bastieri, D.
    Bellazzini, R.
    Berenji, B.
    Blandford, R. D.
    Bloom, E. D.
    Bonamente, E.
    Borgland, A. W.
    Bouvier, A.
    Bregeon, J.
    Brigida, M.
    Bruel, P.
    Buehler, R.
    Buson, S.
    Caliandro, G. A.
    Cameron, R. A.
    Caraveo, P. A.
    Casandjian, J. M.
    Cavazzuti, E.
    Cecchi, C.
    Charles, E.
    Chekhtman, A.
    Cheung, C. C.
    Chiang, J.
    Ciprini, S.
    Claus, R.
    Conrad, Jan
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Cutini, S.
    D'Ammando, F.
    de Angelis, A.
    de Palma, F.
    Dermer, C. D.
    Digel, S. W.
    do Couto e Silva, E.
    Drell, P. S.
    Dubois, R.
    Dumora, D.
    Escande, L.
    Favuzzi, C.
    Fegan, S. J.
    Ferrara, E. C.
    Fortin, P.
    Fukazawa, Y.
    Fusco, P.
    Gargano, F.
    Gasparrini, D.
    Gehrels, N.
    Germani, S.
    Giglietto, N.
    Giommi, P.
    Giordano, F.
    Giroletti, M.
    Glanzman, T.
    Godfrey, G.
    Grenier, I. A.
    Grove, J. E.
    Guiriec, S.
    Hadasch, D.
    Hayashida, M.
    Hays, E.
    Horan, D.
    Itoh, R.
    Johannesson, G.
    Johnson, A. S.
    Kamae, T.
    Katagiri, H.
    Kataoka, J.
    Knoedlseder, J.
    Kuss, M.
    Lande, J.
    Larsson, Stefan
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC). Stockholm University, Faculty of Science, Department of Astronomy.
    Latronico, L.
    Lee, S. -H
    Longo, F.
    Loparco, F.
    Lott, B.
    Lovellette, M. N.
    Lubrano, P.
    Madejski, G. M.
    Makeev, A.
    Mazziotta, M. N.
    McConville, W.
    McEnery, J. E.
    Michelson, P. F.
    Mitthumsiri, W.
    Mizuno, T.
    Moiseev, A. A.
    Monte, C.
    Monzani, M. E.
    Morselli, A.
    Moskalenko, I. V.
    Murgia, S.
    Naumann-Godo, M.
    Nishino, S.
    Nolan, P. L.
    Norris, J. P.
    Nuss, E.
    Ohsugi, T.
    Okumura, A.
    Orlando, E.
    Ormes, J. F.
    Paneque, D.
    Pelassa, V.
    Pesce-Rollins, M.
    Pierbattista, M.
    Piron, F.
    Porter, T. A.
    Raino, S.
    Rando, R.
    Razzaque, S.
    Reimer, A.
    Reimer, O.
    Ritz, S.
    Roth, M.
    Sadrozinski, H. F. -W
    Sanchez, D.
    Scargle, J. D.
    Schalk, T. L.
    Sgro, C.
    Siskind, E. J.
    Smith, P. D.
    Spandre, G.
    Spinelli, P.
    Strickman, M. S.
    Takahashi, H.
    Takahashi, T.
    Tanaka, T.
    Tanaka, Y.
    Thayer, J. G.
    Thayer, J. B.
    Thompson, D. J.
    Tibaldo, L.
    Torres, D. F.
    Tosti, G.
    Tramacere, A.
    Troja, E.
    Vandenbroucke, J.
    Vasileiou, V.
    Vianello, G.
    Vilchez, N.
    Vitale, V.
    Waite, A. P.
    Wang, P.
    Winer, B. L.
    Wood, K. S.
    Yang, Zhaoyu
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Ziegler, M.
    FERMI GAMMA-RAY SPACE TELESCOPE OBSERVATIONS OF THE GAMMA-RAY OUTBURST FROM 3C454.3 IN NOVEMBER 20102011In: The Astrophysical Journal Letters, ISSN 2041-8205, Vol. 733, no 2, p. L26-Article in journal (Refereed)
    Abstract [en]

    The flat-spectrum radio quasar 3C454.3 underwent an extraordinary 5 day gamma-ray outburst in 2010 November when the daily flux measured with the Fermi Large Area Telescope (LAT) at photon energies E > 100 MeV reached (66 +/- 2) x 10(-6) photons cm(-2) s(-1). This is a factor of three higher than its previous maximum flux recorded in 2009 December and greater than or similar to 5 times brighter than the Vela pulsar, which is normally the brightest source in the gamma-ray sky. The 3 hr peak flux was (85 +/- 5) x 10(-6) photons cm-2 s(-1), corresponding to an apparent isotropic luminosity of (2.1 +/- 0.2) x10(50) erg s(-1), the highest ever recorded for a blazar. In this Letter, we investigate the features of this exceptional event in the gamma-ray band of the Fermi-LAT. In contrast to previous flares of the same source observed with the Fermi-LAT, clear spectral changes are observed during the flare.

  • 49. Abdo, A. A.
    et al.
    Ackermann, M.
    Ajello, M.
    Allafort, A.
    Ballet, J.
    Barbiellini, G.
    Bastieri, D.
    Bechtol, K.
    Bellazzini, R.
    Berenji, B.
    Blandford, R. D.
    Bonamente, E.
    Borgland, A. W.
    Bregeon, J.
    Brigida, M.
    Bruel, P.
    Buehler, R.
    Buson, S.
    Caliandro, G. A.
    Cameron, R. A.
    Camilo, F.
    Caraveo, P. A.
    Cecchi, C.
    Charles, E.
    Chaty, S.
    Chekhtman, A.
    Chernyakova, M.
    Cheung, C. C.
    Chiang, J.
    Ciprini, S.
    Claus, R.
    Cohen-Tanugi, J.
    Cominsky, L. R.
    Corbel, S.
    Cutini, S.
    D'Ammando, F.
    de Angelis, A.
    den Hartog, P. R.
    de Palma, F.
    Dermer, C. D.
    Digel, S. W.
    do Couto e Silva, E.
    Dormody, M.
    Drell, P. S.
    Drlica-Wagner, A.
    Dubois, R.
    Dubus, G.
    Dumora, D.
    Enoto, T.
    Espinoza, C. M.
    Favuzzi, C.
    Fegan, S. J.
    Ferrara, E. C.
    Focke, W. B.
    Fortin, P.
    Fukazawa, Y.
    Funk, S.
    Fusco, P.
    Gargano, F.
    Gasparrini, D.
    Gehrels, N.
    Germani, S.
    Giglietto, N.
    Giommi, P.
    Giordano, F.
    Giroletti, M.
    Glanzman, T.
    Godfrey, G.
    Grenier, I. A.
    Grondin, M. -H
    Grove, J. E.
    Grundstrom, E.
    Guiriec, S.
    Gwon, C.
    Hadasch, D.
    Harding, A. K.
    Hayashida, M.
    Hays, E.
    Johannesson, G.
    Johnson, A. S.
    Johnson, T. J.
    Johnston, S.
    Kamae, T.
    Katagiri, H.
    Kataoka, J.
    Keith, M.
    Kerr, M.
    Knodlseder, J.
    Kramer, M.
    Kuss, M.
    Lande, J.
    Lee, S. -H
    Lemoine-Goumard, M.
    Longo, F.
    Loparco, F.
    Lovellette, M. N.
    Lubrano, P.
    Manchester, R. N.
    Marelli, M.
    Mazziotta, M. N.
    Michelson, P. F.
    Mitthumsiri, W.
    Mizuno, T.
    Moiseev, A. A.
    Monte, C.
    Monzani, M. E.
    Morselli, A.
    Moskalenko, I. V.
    Murgia, S.
    Nakamori, T.
    Naumann-Godo, M.
    Neronov, A.
    Nolan, P. L.
    Norris, J. P.
    Noutsos, A.
    Nuss, E.
    Ohsugi, T.
    Okumura, A.
    Omodei, N.
    Orlando, E.
    Paneque, D.
    Parent, D.
    Pesce-Rollins, M.
    Pierbattista, M.
    Piron, F.
    Porter, T. A.
    Possenti, A.
    Raino, S.
    Rando, R.
    Ray, P. S.
    Razzano, M.
    Razzaque, S.
    Reimer, A.
    Reimer, O.
    Reposeur, T.
    Ritz, S.
    Sadrozinski, H. F. -W
    Scargle, J. D.
    Sgro, C.
    Shannon, R.
    Siskind, E. J.
    Smith, P. D.
    Spandre, G.
    Spinelli, P.
    Strickman, M. S.
    Suson, D. J.
    Takahashi, H.
    Tanaka, T.
    Thayer, J. G.
    Thayer, J. B.
    Thompson, D. J.
    Thorsett, S. E.
    Tibaldo, L.
    Tibolla, O.
    Torres, D. F.
    Tosti, G.
    Troja, E.
    Uchiyama, Y.
    Usher, T. L.
    Vandenbroucke, J.
    Vasileiou, V.
    Vianello, G.
    Vitale, V.
    Waite, A. P.
    Wang, P.
    Winer, B. L.
    Wolff, M. T.
    Wood, D. L.
    Wood, K. S.
    Yang, Zhaoyu
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Ziegler, M.
    Zimmer, Stephan
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    DISCOVERY OF HIGH-ENERGY GAMMA-RAY EMISSION FROM THE BINARY SYSTEM PSR B1259-63/LS 2883 AROUND PERIASTRON WITH FERMI2011In: Astrophysical Journal Letters, ISSN 2041-8205, Vol. 736, no 1, p. L11-Article in journal (Refereed)
    Abstract [en]

    We report on the discovery of >= 100 MeV gamma-rays from the binary system PSR B1259-63/LS 2883 using the Large Area Telescope (LAT) on board Fermi. The system comprises a radio pulsar in orbit around a Be star. We report on LAT observations from near apastron to similar to 128 days after the time of periastron, t(p), on 2010 December 15. No gamma-ray emission was detected from this source when it was far from periastron. Faint gamma-ray emission appeared as the pulsar approached periastron. At similar to t(p) + 30 days, the >= 100 MeV gamma-ray flux increased over a period of a few days to a peak flux 20-30 times that seen during the pre-periastron period, but with a softer spectrum. For the following month, it was seen to be variable on daily timescales, but remained at similar to(1-4) x 10(-6) cm(-2) s(-1) before starting to fade at similar to t(p) + 57 days. The total gamma-ray luminosity observed during this period is comparable to the spin-down power of the pulsar. Simultaneous radio and X-ray observations of the source showed no corresponding dramatic changes in radio and X-ray flux between the pre-periastron and post-periastron flares. We discuss possible explanations for the observed gamma-ray-only flaring of the source.

  • 50. Abdo, A. A.
    et al.
    Ackermann, M.
    Ajello, M.
    Ampe, J.
    Anderson, B.
    Atwood, W. B.
    Axelsson, M.
    Stockholm University, Faculty of Science, Department of Astronomy.
    Bagagli, R.
    Baldini, L.
    Ballet, J.
    Barbiellini, G.
    Bartelt, J.
    Bastieri, D.
    Baughman, B. M.
    Bechtol, K.
    Bédérède, D.
    Bellardi, F.
    Bellazzini, R.
    Belli, F.
    Berenji, B.
    Bisello, D.
    Bissaldi, E.
    Bloom, E. D.
    Bogaert, G.
    Bogart, J. R.
    Bonamente, E.
    Borgland, A. W.
    Bourgeois, P.
    Bouvier, A.
    Bregeon, J.
    Brez, A.
    Brigida, M.
    Bruel, P.
    Burnett, T. H.
    Busetto, G.
    Caliandro, G. A.
    Cameron, R. A.
    Campell, M.
    Caraveo, P. A.
    Carius, S.
    Carlson, P.
    Casandjian, J. M.
    Cavazzuti, E.
    Ceccanti, M.
    Cecchi, C.
    Charles, E.
    Chekhtman, A.
    Cheung, C. C.
    Chiang, J.
    Chipaux, R.
    Cillis, A. N.
    Ciprini, S.
    Claus, R.
    Cohen-Tanugi, J.
    Condamoor, S.
    Conrad, J.
    Stockholm University, Faculty of Science, Department of Physics.
    Corbet, R.
    Cutini, S.
    Davis, D. S.
    Deklotz, M.
    Dermer, C. D.
    de Angelis, A.
    de Palma, F.
    Digel, S. W.
    Dizon, P.
    Dormody, M.
    Do Couto E Silva, E.
    Drell, P. S.
    Dubois, R.
    Dumora, D.
    Edmonds, Y.
    Fabiani, D.
    Farnier, C.
    Favuzzi, C.
    Ferrara, E. C.
    Ferreira, O.
    Fewtrell, Z.
    Flath, D. L.
    Fleury, P.
    Focke, W. B.
    Fouts, K.
    Frailis, M.
    Freytag, D.
    Fukazawa, Y.
    Funk, S.
    Fusco, P.
    Gargano, F.
    Gasparrini, D.
    Gehrels, N.
    Germani, S.
    Giebels, B.
    Giglietto, N.
    Giordano, F.
    Glanzman, T.
    Godfrey, G.
    Goodman, J.
    Grenier, I. A.
    Grondin, M.-H.
    Grove, J. E.
    Guillemot, L.
    Guiriec, S.
    Hakimi, M.
    Haller, G.
    Hanabata, Y.
    Hart, P. A.
    Hascall, P.
    Hays, E.
    Huffer, M.
    Hughes, R. E.
    Jóhannesson, G.
    Johnson, A. S.
    Johnson, R. P.
    Johnson, T. J.
    Johnson, W. N.
    Kamae, T.
    Katagiri, H.
    Kataoka, J.
    Kavelaars, A.
    Kelly, H.
    Kerr, M.
    Klamra, W.
    Knödlseder, J.
    Kocian, M. L.
    Kuehn, F.
    Kuss, M.
    Latronico, L.
    Lavalley, C.
    Leas, B.
    Lee, B.
    Lee, S.-H.
    Lemoine-Goumard, M.
    Longo, F.
    Loparco, F.
    Lott, B.
    Lovellette, M. N.
    Lubrano, P.
    Lung, D. K.
    Madejski, G. M.