%0 Journal Article
%T Fermi LAT observations of the Geminga pulsar
%+ Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112))
%+ Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG)
%+ Laboratoire Leprince-Ringuet (LLR)
%+ Laboratoire de Physique Théorique et Astroparticules (LPTA)
%+ Centre d'étude spatiale des rayonnements (CESR)
%A A. Abdo, A.
%A Ackermann, Markus
%A Ajello, Marco
%A Baldini, Luca
%A Ballet, Jean
%A Barbiellini, Guido
%A Bastieri, D.
%A M. Baughman, B.
%A Bechtol, K.
%A Bellazzini, R.
%A Berenji, B.
%A F. Bignami, G.
%A D. Blandford, R.
%A D. Bloom, E.
%A Bonamente, E.
%A W. Borgland, A.
%A Bregeon, J.
%A Brez, A.
%A Brigida, M.
%A Bruel, Pascal
%A H. Burnett, T.
%A A. Caliandro, G.
%A A. Cameron, R.
%A Caraveo, P. A.
%A M. Casandjian, J.
%A Cecchi, C.
%A Celik, O.
%A Charles, E.
%A Chekhtman, A.
%A C. Cheung, C.
%A Chiang, J.
%A Ciprini, S.
%A Claus, R.
%A Cohen-Tanugi, J.
%A Conrad, J.
%A D. Dermer, C.
%A de Palma, F.
%A Dormody, M.
%A Do Couto E Silva, E.
%A S. Drell, P.
%A Dubois, R.
%A Dumora, D.
%A Edmonds, Y.
%A Farnier, C.
%A Favuzzi, C.
%A J. Fegan, S.
%A B. Focke, W.
%A Fortin, P.
%A Frailis, M.
%A Fukazawa, Y.
%A Funk, S.
%A Fusco, P.
%A Gargano, F.
%A Gasparrini, D.
%A Gehrels, N.
%A Germani, S.
%A Giavitto, G.
%A Giglietto, N.
%A Giordano, F.
%A Glanzman, T.
%A Godfrey, G.
%A A. Grenier, I.
%A Grondin, M.-H.
%A E. Grove, J.
%A Guillemot, L.
%A Guiriec, S.
%A Hadasch, D.
%A K. Harding, A.
%A Hays, E.
%A E. Hughes, R.
%A Johannesson, G.
%A S. Johnson, A.
%A J. Johnson, T.
%A N. Johnson, W.
%A Kamae, T.
%A Katagiri, H.
%A Kataoka, J.
%A Kawai, N.
%A Kerr, M.
%A Knödlseder, Jürgen
%A Kuss, M.
%A Lande, J.
%A Latronico, L.
%A Lemoine-Goumard, M.
%A Longo, F.
%A Loparco, F.
%A Lott, B.
%A N. Lovellette, M.
%A Lubrano, P.
%A Makeev, A.
%A Marelli, M.
%A N. Mazziotta, M.
%A E. Mcenery, J.
%A Meurer, C.
%A F. Michelson, P.
%A Mitthumsiri, W.
%A Mizuno, T.
%A A. Moiseev, A.
%A Monte, C.
%A E. Monzani, M.
%A Morselli, A.
%A V. Moskalenko, I.
%A Murgia, S.
%A L. Nolan, P.
%A P. Norris, J.
%A Nuss, E.
%A Ohsugi, T.
%A Omodei, N.
%A Orlando, E.
%A F. Ormes, J.
%A Ozaki, M.
%A Paneque, D.
%A H. Panetta, J.
%A Parent, D.
%A Pelassa, V.
%A Pepe, M.
%A Pesce-Rollins, M.
%A Piron, F.
%A Porter, T.A.
%A Raino, S.
%A Rando, R.
%A S. Ray, P.
%A Razzano, M.
%A Reimer, A.
%A Reimer, O.
%A Reposeur, T.
%A S. Rochester, L.
%A Y. Rodriguez, A.
%A W. Romani, R.
%A Roth, M.
%A Ryde, F.
%A F.-W. Sadrozinski, H.
%A Sander, A.
%A M. Saz Parkinson, P.
%A D. Scargle, J.
%A Sgro, C.
%A J. Siskind, E.
%A Smith, David Stanley
%A D. Smith, P.
%A Spandre, G.
%A Spinelli, P.
%A S. Strickman, M.
%A J. Suson, D.
%A Takahashi, H.
%A Takahashi, T.
%A Tanaka, T.
%A B. Thayer, J.
%A G. Thayer, J.
%A J. Thompson, D.
%A Tibaldo, L.
%A F. Torres, D.
%A Tosti, G.
%A Tramacere, A.
%A L. Usher, T.
%A van Etten, A.
%A Vasileiou, V.
%A Venter, C.
%A Vilchez, N.
%A Vitale, V.
%A P. Waite, A.
%A Wang, P.
%A Watters, K.
%A L. Winer, B.
%A S. Wood, K.
%A Ylinen, T.
%A Ziegler, M.
%Z 32 pages, 12 figures, 3 tables. Accepted for publication in The Astrophysical Journal. Corresponding authors: Denis Dumora (dumora@cenbg.in2p3.fr), Fabio Gargano (Fabio.Gargano@ba.infn.it), Massimiliano Razzano (massimiliano.razzano@pi.infn.it)
%< avec comité de lecture
%@ 0004-637X
%J The Astrophysical Journal
%I American Astronomical Society
%V 720
%P 272-283
%8 2010-09-01
%D 2010
%Z 1007.1142
%R 10.1088/0004-637X/720/1/272
%K gamma rays: stars
%K pulsars: general
%K pulsars: individual (PSR J0633+1746
%K Geminga)
%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 We report on the \textit{Fermi}-LAT observations of the Geminga pulsar, the second brightest non-variable GeV source in the $\gamma$-ray sky and the first example of a radio-quiet $\gamma$-ray pulsar. The observations cover one year, from the launch of the $Fermi$ satellite through 2009 June 15. A data sample of over 60,000 photons enabled us to build a timing solution based solely on $\gamma$ rays. Timing analysis shows two prominent peaks, separated by $\Delta \phi$ = 0.497 $\pm$ 0.004 in phase, which narrow with increasing energy. Pulsed $\gamma$ rays are observed beyond 18 GeV, precluding emission below 2.7 stellar radii because of magnetic absorption. The phase-averaged spectrum was fitted with a power law with exponential cut-off of spectral index $\Gamma$ = (1.30 $\pm$ 0.01 $\pm$ 0.04), cut-off energy $E_{0}$ = (2.46 $\pm$ 0.04 $\pm$ 0.17) GeV and an integral photon flux above 0.1 GeV of (4.14 $\pm$ 0.02 $\pm$ 0.32) $\times$ 10$^{-6}$ cm$^{-2}$ s$^{-1}$. The first uncertainties are statistical and the second are systematic. The phase-resolved spectroscopy shows a clear evolution of the spectral parameters, with the spectral index reaching a minimum value just before the leading peak and the cut-off energy having maxima around the peaks. Phase-resolved spectroscopy reveals that pulsar emission is present at all rotational phases. The spectral shape, broad pulse profile, and maximum photon energy favor the outer magnetospheric emission scenarios.
%G English
%Z Fermi-LAT
%L in2p3-00530035
%U https://hal.in2p3.fr/in2p3-00530035
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