Detection of Pulsed Gamma Rays Above 100 GeV from the Crab Pulsar

Aliu E; Arlen T; Aune T; Beilicke M; Benbow W; Bouvier A; Bradbury SM; Buckley JH; Bugaev V; Byrum K; Cannon A; Cesarini A; Christiansen JL; Ciupik L; Collins-Hughes E; Connolly MP; Cui W; Dickherber R; Duke C; Errando M; Falcone A; Finley JP; Finnegan G; Fortson L; Furniss A; Galante N; Gall D; Gibbs K; Gillanders GH; Godambe S; Griffin S; Grube J; Guenette R; Gyuk G; Hanna D; Holder J; Huan H; Hughes G; Hui CM; Humensky TB; Imran A; Kaaret P; Karlsson N; Kertzman M; Kieda D; Krawczynski H; Krennrich F; Lang MJ; Lyutikov M; Madhavan AS; Maier G; Majumdar P; McArthur S; McCann A; McCutcheon M; Moriarty P; Mukherjee R; Nunez P; Ong RA; Orr M; Otte AN; Park N; Perkins JS; Pizlo F; Pohl M; Prokoph H; Quinn J; Ragan K; Reyes LC; Reynolds PT; Roache E; Rose HJ; Ruppel J; Saxon DB; Schroedter M; Sembroski GH; Senturk GD; Smith AW; Staszak D; Tesic G; Theiling M; Thibadeau S; Tsurusaki K; Tyler J; Varlotta A; Vassiliev VV; Vincent S; Vivier M; Wakely SP; Ward JE; Weekes TC; Weinstein A; Weisgarber T; Williams DA; Zitzer B

Science, Vol.333, No.6052, 69-72, 2011

DOI10.1126/science.1208192 Export Citation

Detection of Pulsed Gamma Rays Above 100 GeV from the Crab Pulsar

Aliu E, Arlen T, Aune T, Beilicke M, Benbow W, Bouvier A, Bradbury SM, Buckley JH, Bugaev V, Byrum K, Cannon A, Cesarini A, Christiansen JL, Ciupik L, Collins-Hughes E, Connolly MP, Cui W, Dickherber R, Duke C, Errando M, Falcone A, Finley JP, Finnegan G, Fortson L, Furniss A, Galante N, Gall D, Gibbs K, Gillanders GH, Godambe S, Griffin S, Grube J, Guenette R, Gyuk G, Hanna D, Holder J, Huan H, Hughes G, Hui CM, Humensky TB, Imran A, Kaaret P, Karlsson N, Kertzman M, Kieda D, Krawczynski H, Krennrich F, Lang MJ, Lyutikov M, Madhavan AS, Maier G, Majumdar P, McArthur S, McCann A, McCutcheon M, Moriarty P, Mukherjee R, Nunez P, Ong RA, Orr M, Otte AN, Park N, Perkins JS, Pizlo F, Pohl M, Prokoph H, Quinn J, Ragan K, Reyes LC, Reynolds PT, Roache E, Rose HJ, Ruppel J, Saxon DB, Schroedter M, Sembroski GH, Senturk GD, Smith AW, Staszak D, Tesic G, Theiling M, Thibadeau S, Tsurusaki K, Tyler J, Varlotta A, Vassiliev VV, Vincent S, Vivier M, Wakely SP, Ward JE, Weekes TC, Weinstein A, Weisgarber T, Williams DA, Zitzer B

We report the detection of pulsed gamma rays from the Crab pulsar at energies above 100 giga-electron volts (GeV) with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) array of atmospheric Cherenkov telescopes. The detection cannot be explained on the basis of current pulsar models. The photon spectrum of pulsed emission between 100 mega-electron volts and 400 GeV is described by a broken power law that is statistically preferred over a power law with an exponential cutoff. It is unlikely that the observation can be explained by invoking curvature radiation as the origin of the observed gamma rays above 100 GeV. Our findings require that these gamma rays be produced more than 10 stellar radii from the neutron star.