Fermi-LAT Observations of the Gamma-Ray Burst GRB 130427A

M Ackermann,A Schulz,G Barbiellini,J Conrad,M Deklotz,S Cutini,D Tierney,N Giglietto,J E Mcenery,J Chiang,M Roth,G Fitzpatrick,S Funk,H Tajima,J Cohen-Tanugi,C Wilson-Hodge,M Ohno,V Vasileiou,E Bissaldi,M Kuss,A Okumura,F De Palma,F Gargano,S Guiriec,P Lubrano,D Horan,W B Focke,Y Hanabata,G Cusumano,F Piron,A De Angelis,I A Grenier,F Longo,S J Fegan,E C Ferrara,H Takahashi,R Claus,E Troja,R E Hughes,C Meegan,S Ritz,M Tinivella,B L Winer,C Favuzzi,C D Dermer,C Kouveliotou,V Petrosian,V La Parola,G Tosti,M Pesce-Rollins,E Bonamente,J Bregeon,S Razzaque,M E Monzani,C C Cheung,D Paneque,R A Cameron,R Nemmen,W B Atwood,D F Torres,A K Harding,A Sartori,S Ciprini,F D’Ammando,R Preece,J G Thayer,V Connaughton,A J Van Der Horst,S Rainò,M N Mazziotta,R Rando,A Franckowiak,K S Wood,D Hadasch,M Ajello,P S Drell,A Von Kienlin,E Hays,S Foley,J S Perkins,L Tibaldo,V Chaplin,J L Racusin,R Desiante,W N Johnson,P M Saz Parkinson,M Hayashida,A Chekhtman,S Buson,L Di Venere,P N Bhat,J Finke,A Drlica-Wagner,S J Zhu,T Ohsugi,R Buehler,T Jogler,A Diekmann,M S Briggs,G Chiaro,V Pelassa,S Murgia,P Jenke,M Razzano,P A Caraveo,R M Kippen,E Moretti,L Latronico,J Michael Burgess,C Cecchi,G Pivato,G Godfrey,J B Thayer,D Bastieri,P Spinelli,G Spandre,V Vitale,M Orienti,N Omodei,A Goldstein,S Germani,T Mizuno,M Mayer,G A Caliandro,M N Lovellette,F Giordano,E Charles,I V Moskalenko,A Morselli,A Rau,K Bechtol,G Vianello,F Loparco,E Nuss,T A Porter,P Fusco,M Axelsson,C Sgrò,D Kocevski,J Ballet,M Giroletti,J R Cummings,D J Thompson,P F Michelson,A Reimer,J Knödlseder,N Gehrels,J E Grove,S Mcbreen,M Brigida,J Vandenbroucke,R Bellazzini,E J Siskind,F Ryde,D Gruber,J Landé ,W H Cleveland ,H F Yu ,George Younes ,Katsuaki Asano ,L Cominsky ,Pascal Bruel ,Stefan Larsson ,W S Pačiesas ,Ryo Yamazaki ,M H Gibby ,M M Giles ,T Usher ,Dave Byrne ,Э Сонбас ,Takafumi Kawano ,А А Моисеев ,G Jøhannesson ,A C Collazzi ,Jonathan Granot ,S L Xiong ,Matthew G Baring ,Yasushi Fukazawa ,Jeffrey D Scargle ,Yoshiyuki Inoue ,Luca Baldini

doi:10.1126/science.1242353

Abstract

The observations of the exceptionally bright gamma-ray burst (GRB) 130427A by the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope provide constraints on the nature of these unique astrophysical sources. GRB 130427A had the largest fluence, highest-energy photon (95 GeV), longest γ-ray duration (20 hours), and one of the largest isotropic energy releases ever observed from a GRB. Temporal and spectral analyses of GRB 130427A challenge the widely accepted model that the nonthermal high-energy emission in the afterglow phase of GRBs is synchrotron emission radiated by electrons accelerated at an external shock.

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