The Fermi observatory is advancing our knowledge of gamma-ray bursts (GRBs) through pioneering observations at high energies, covering more than seven decades in energy with the two on-board detectors, the Large Area Telescope (LAT) and the Gamma-ray Burst Monitor (GBM). Here, we report on the observation of the long GRB 090217A which triggered the GBM and has been detected by the LAT with a significance greater than 9σ. We present the GBM and LAT observations and on-ground analyses, including the time-resolved spectra and the study of the temporal profile from 8 keV up to ~1 GeV. All spectra are well reproduced by a Band model. We compare these observations to the first two LAT-detected, long bursts GRB 080825C and GRB 080916C. These bursts were found to have time-dependent spectra and exhibited a delayed onset of the high-energy emission, which are not observed in the case of GRB 090217A. We discuss some theoretical implications for the high-energy emission of GRBs.

FERMI OBSERVATIONS OF HIGH-ENERGY GAMMA-RAY EMISSION FROM GRB 090217A

BALDINI, LUCA;RAZZANO, MASSIMILIANO;
2010-01-01

Abstract

The Fermi observatory is advancing our knowledge of gamma-ray bursts (GRBs) through pioneering observations at high energies, covering more than seven decades in energy with the two on-board detectors, the Large Area Telescope (LAT) and the Gamma-ray Burst Monitor (GBM). Here, we report on the observation of the long GRB 090217A which triggered the GBM and has been detected by the LAT with a significance greater than 9σ. We present the GBM and LAT observations and on-ground analyses, including the time-resolved spectra and the study of the temporal profile from 8 keV up to ~1 GeV. All spectra are well reproduced by a Band model. We compare these observations to the first two LAT-detected, long bursts GRB 080825C and GRB 080916C. These bursts were found to have time-dependent spectra and exhibited a delayed onset of the high-energy emission, which are not observed in the case of GRB 090217A. We discuss some theoretical implications for the high-energy emission of GRBs.
2010
Ackermann, M; Ajello, M; Baldini, Luca; Ballet, J; Barbiellini, G; Baring, Mg; Bastieri, D; Bechtol, K; Bellazzini, R; Berenji, B; Bhat, Pn; Bissaldi, E; Blandford, Rd; Bonamente, E; Borgland, Aw; Bouvier, A; Bregeon, J; Brez, A; Briggs, Ms; Brigida, M; Bruel, P; Buehler, R; Buson, S; Caliandro, Ga; Cameron, Ra; Caraveo, Pa; Carrigan, S; Casandjian, Jm; Cecchi, C; Celik, O; Charles, E; Chekhtman, A; Chiang, J; Ciprini, S; Claus, R; Cohen Tanugi, J; Connaughton, V; Conrad, J; Cutini, S; Dermer, Cd; de Angelis, A; de Palma, F; Digel, Sw; do Couto e., Silva E; Drell, Ps; Dubois, R; Favuzzi, C; Fegan, Sj; Ferrara, Ec; Frailis, M; Fukazawa, Y; Fusco, P; Gargano, F; Gasparrini, D; Gehrels, N; Germani, S; Giglietto, N; Giommi, P; Giordano, F; Giroletti, M; Glanzman, T; Godfrey, G; Granot, J; Grenier, Ia; Grove, Je; Guillemot, L; Guiriec, S; Hadasch, D; Hays, E; Horan, D; Hughes, Re; Johannesson, G; Johnson, As; Johnson, Wn; Kamae, T; Katagiri, H; Kippen, Rm; Knodlseder, J; Kocevski, D; Kuss, M; Lande, J; Latronico, L; Lee, Sh; Garde, Ml; Longo, F; Loparco, F; Lovellette, Mn; Lubrano, P; Makeev, A; Mazziotta, Mn; Mcbreen, S; Mcenery, Je; Mcglynn, S; Meegan, C; Mehault, J; Meszaros, P; Michelson, Pf; Mizuno, T; Moiseev, Aa; Monte, C; Monzani, Me; Moretti, E; Morselli, A; Moskalenko, Iv; Murgia, S; Nakajima, H; Nakamori, T; Naumann Godo, M; Nolan, Pl; Norris, Jp; Nuss, E; Ohno, M; Ohsugi, T; Okumura, A; Omodei, N; Orlando, E; Ormes, Jf; Ozaki, M; Paciesas, Ws; Paneque, D; Panetta, Jh; Parent, D; Pelassa, V; Pepe, M; Pesce Rollins, M; Petrosian, V; Piron, F; Porter, Ta; Preece, R; Racusin, Jl; Raino, S; Rando, R; Rau, A; Razzano, Massimiliano; Razzaque, S; Reimer, A; Reimer, O; Ripken, J; Roth, M; Ryde, F; Sadrozinski, Hfw; Sander, A; Scargle, Jd; Schalk, Tl; Sgro, C; Siskind, Ej; Smith, Pd; Spandre, G; Spinelli, P; Stamatikos, M; Strickman, Ms; Suson, Dj; Tajima, H; Takahashi, H; Tanaka, T; Thayer, Jb; Thayer, Jg; Tibaldo, L; Torres, Df; Tosti, G; Tramacere, A; Uehara, T; Usher, Tl; Vandenbroucke, J; van der Horst, Aj; Vasileiou, V; Vilchez, N; Vitale, V; von Kienlin, A; Waite, Ap; Wang, P; Wilson Hodge, C; Winer, Bl; Wood, Ks; Wu, Xf; Yamazaki, R; Yang, Z; Ylinen, T; Ziegler, M.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11568/194966
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