%0 Journal Article
%T GRB110721A: An extreme peak energy and signatures of the photosphere
%+ Laboratoire Leprince-Ringuet (LLR)
%+ Max-Planck-Institut für Kernphysik (MPIK)
%+ GLAST
%+ Laboratoire Univers et Particules de Montpellier (LUPM)
%A Axelsson, Magnus
%A Baldini, Luca
%A Barbiellini, Guido
%A G. Baring, M.
%A Bellazzini, R.
%A Bregeon, J.
%A Brigida, M.
%A Bruel, Pascal
%A Buehler, R.
%A A. Caliandro, G.
%A A. Cameron, R.
%A Caraveo, P. A.
%A Cecchi, C.
%A Chaves, R.C.G.
%A Chekhtman, A.
%A Chiang, J.
%A Claus, R.
%A Conrad, J.
%A Cutini, S.
%A d'Ammando, F.
%A de Palma, F.
%A D. Dermer, C.
%A Do Couto E Silva, E.
%A S. Drell, P.
%A Favuzzi, C.
%A J. Fegan, S.
%A C. Ferrara, E.
%A B. Focke, W.
%A Fukazawa, Y.
%A Fusco, P.
%A Gargano, F.
%A Gasparrini, D.
%A Gehrels, N.
%A Germani, S.
%A Giglietto, N.
%A Giroletti, M.
%A Godfrey, G.
%A Guiriec, S.
%A Hadasch, D.
%A Hanabata, Y.
%A Hayashida, M.
%A Hou, X.
%A Iyyani, S.
%A S. Jackson, M.
%A Kocevski, D.
%A Kuss, M.
%A Larsson, J.
%A Larsson, S.
%A Longo, F.
%A Loparco, F.
%A Lundman, C.
%A N. Mazziotta, M.
%A E. Mcenery, J.
%A Mizuno, T.
%A E. Monzani, M.
%A Moretti, E.
%A Morselli, A.
%A Murgia, S.
%A Nuss, E.
%A Nymark, T.
%A Ohno, M.
%A Omodei, N.
%A Pesce-Rollins, M.
%A Piron, F.
%A Pivato, G.
%A L. Racusin, J.
%A Rain'O, S.
%A Razzano, M.
%A Razzaque, S.
%A Reimer, A.
%A Roth, M.
%A Ryde, F.
%A Sanchez, D.A.
%A Sgr'O, C.
%A J. Siskind, E.
%A Spandre, G.
%A Spinelli, P.
%A Stamatikos, M.
%A Tibaldo, L.
%A Tinivella, M.
%A L. Usher, T.
%A Vandenbroucke, J.
%A Vasileiou, V.
%A Vianello, G.
%A Vitale, V.
%A P. Waite, A.
%A L. Winer, B.
%A S. Wood, K.
%A M. Burgess, J.
%A N. Bhat, P.
%A Bissaldi, E.
%A S. Briggs, M.
%A Connaughton, V.
%A Fishman, G.
%A Fitzpatrick, G.
%A Foley, S.
%A Gruber, D.
%A M. Kippen, R.
%A Kouveliotou, C.
%A Jenke, P.
%A Mcbreen, S.
%A Mcglynn, S.
%A Meegan, C.
%A S. Pacisas, W.
%A Pelassa, V.
%A Preece, R.
%A Tierney, D.
%A von Kienlin, A.
%A Wilson-Hodge, C.
%A Xiong, S.
%A Pe'Er, A.
%< avec comité de lecture
%@ 2041-8205
%J The Astrophysical journal letters
%I Bristol : IOP Publishing
%V 757
%P L31
%8 2012
%D 2012
%Z 1207.6109
%R 10.1088/2041-8205/757/2/L31
%Z Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE]
%Z Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE]Journal articles
%X GRB110721A was observed by the Fermi Gamma-ray Space Telescope using its two instruments the Large Area Telescope (LAT) and the Gamma-ray Burst Monitor (GBM). The burst consisted of one major emission episode which lasted for ~24.5 seconds (in the GBM) and had a peak flux of 5.7\pm0.2 x 10^{-5} erg/s/cm^2. The time-resolved emission spectrum is best modeled with a combination of a Band function and a blackbody spectrum. The peak energy of the Band component was initially 15\pm2 MeV, which is the highest value ever detected in a GRB. This measurement was made possible by combining GBM/BGO data with LAT Low Energy Events to achieve continuous 10--100 MeV coverage. The peak energy later decreased as a power law in time with an index of -1.89\pm0.10. The temperature of the blackbody component also decreased, starting from ~80 keV, and the decay showed a significant break after ~2 seconds. The spectrum provides strong constraints on the standard synchrotron model, indicating that alternative mechanisms may give rise to the emission at these energies.
%G English
%L in2p3-00743070
%U https://hal.in2p3.fr/in2p3-00743070
%~ IN2P3
%~ X
%~ CENBG
%~ LLR
%~ CNRS
%~ UNIV-MONTP2
%~ X-LLR
%~ X-DEP
%~ X-DEP-PHYS
%~ LUPM
%~ MIPS
%~ UNIV-MONTPELLIER
%~ LUPM_EMA
%~ UM1-UM2