Abdo AA, Ackermann M, Ajello M, Baldini L, Ballet J, Barbiellini G, Bastier D, Baughman BM, Bechtol K, Bellazzini R, Berenji B, Bignami GF, Blandford RD, Bloom ED, Bonamente E, Borgland AW, Bregeon J, Brez A, Brigida M, Brueli P, Burnett TH, Caliandro GA, Cameron RA, Caraveo PA, Casandjian JM, Cecchi C, Celik O, Charles E, Chekhtman A, Cheung CC, Chiang J, Ciprini S, Claus R, Cohen-Tanugi J, Conrad J, Dermer CD, De Palma F, Dormody M, Do Couto E Silva E, Drell PS, Dubois R, Dumora D, Edmonds Y, Farnier C, Favuzzi C, Fegan SJ, Focke WB, Fortin P, Frailis M, Furazawa Y, Funk S, Fusco P, Gargano F, Gasparrini D, Gehrels N, Germani S, Giavitto G, Giglietto N, Giordano F, Glanzman T, Godfrey G, Grenier IA, Grondin MH, Grove JE, Guillemot L, Guiriec S, Hadasch D, Hardino AK, Hays E, Hughes RE, Johannesson G, Johnson AS, Johnson TJ, Johnson WN, Kamae T, Katagiri H, Kataoka J, Kawai N, Kerr M, Knoedlseder J, Kuss MW, Lande J, Latronico L, Lemoine-Goumard M, Longo F, Loparco F, Lott B, Lovellette MN, Lubrano P, Makeev A, Marelli M, Mazziotta MN, Mcenery JE, Meurer C, Michelson PF, Mitthumsiri W, Mizuno T, Moiseev AA, Monte C, Monzani ME, Morselli A, Moskalenk IV, Murgia S, Nolan PL, Norris JP, Nuss E, Ohsugi T, Omodei N, Orlando E, Ormes JF, Ozaki M, Paneque D, Panetta JH, Parent D, Pelassa V, Pepe M, Pesce-Rollins M, Piron F, Porter TA, Raino S, Rando R, Rayi PS, Razzano M, Reimer A, Reimer O, Reposeur T, Rochester LS, Rodriguez AY, Romani RW, Roth M, Ryde F, Sadrozinski HFW, Sander A, Parkinson PMS, Scargle JD, Sgro C, Siskind EJ, Smith DA, Smith PD, Spandre G, Spinelli P, Strickman MS, Suson DJ, Takahashi HH, Takahashi T, Tanaka T, Thayer JB, Thayer JG, Thompson DJ, Tibaldo L, Torres DF, Tosti G, Tramacere A, Usher TL, Van Etten A, Vasileiou V, Venter C, Vilchez N, Vitale V, Waite AP, Wang P, Watters K, Winer BL, Wood KS, Ylinen T, Ziegler M (2010)
Publication Type: Journal article
Publication year: 2010
Book Volume: 720
Pages Range: 272-283
Journal Issue: 1
DOI: 10.1088/0004-637X/720/1/272
We report on the 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 +/- 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 cutoff of spectral index Gamma = (1.30 +/- 0.01 +/- 0.04), cutoff energy E-0 = (2.46 +/- 0.04 +/- 0.17) GeV, and an integral photon flux above 0.1 GeV of (4.14 +/- 0.02 +/- 0.32) x 10(-6) cm(-2) s(-1). The first uncertainties are statistical and the second ones 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 cutoff energy having maxima around the peaks. The 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.
APA:
Abdo, A.A., Ackermann, M., Ajello, M., Baldini, L., Ballet, J., Barbiellini, G.,... Ziegler, M. (2010). FERMI-LAT OBSERVATIONS OF THE GEMINGA PULSAR. Astrophysical Journal, 720(1), 272-283. https://doi.org/10.1088/0004-637X/720/1/272
MLA:
Abdo, A. A., et al. "FERMI-LAT OBSERVATIONS OF THE GEMINGA PULSAR." Astrophysical Journal 720.1 (2010): 272-283.
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