Fermi large area telescope observations of the crab pulsar and nebula

A. A. Abdo; M. Ackermann; M. Ajello; W. B. Atwood; M. Axelsson; L. Baldini; J. Ballet; G. Barbiellini; M. G. Baring; D. Bastieri; K. Bechtol; R. Bellazzini; B. Berenji; R. D. Blandford; E. D. Bloom; E. Bonamente; A. W. Borgland; J. Bregeon; A. Brez; M. Brigida; P. Bruel; T. H. Burnett; G. A. Caliandro; R. A. Cameron; F. Camilo; P. A. Caraveo; J. M. Casandjian; C. Cecchi; Ö Çelik; A. Chekhtman; C. C. Cheung; J. Chiang; S. Ciprini; R. Claus; I. Cognard; J. Cohen-Tanugi; L. R. Cominsky; J. Conrad; C. D. Dermer; A. De Angelis; A. De Luca; F. De Palma; S. W. Digel; E. Do Couto E Silva; P. S. Drell; R. Dubois; D. Dumora; C. Espinoza; C. Farnier; C. Favuzzi; S. J. Fegan; E. C. Ferrara; W. B. Focke; M. Frailis; P. C.C. Freire; Y. Fukazawa; S. Funk; P. Fusco; F. Gargano; D. Gasparrini; N. Gehrels; S. Germani; G. Giavitto; B. Giebels; N. Giglietto; F. Giordano; T. Glanzman; G. Godfrey; I. A. Grenier; M. H. Grondin; J. E. Grove; L. Guillemot; S. Guiriec; Y. Hanabata; A. K. Harding; M. Hayashida; E. Hays; R. E. Hughes; G. Jóhannesson; A. S. Johnson; R. P. Johnson; T. J. Johnson; W. N. Johnson; S. Johnston; T. Kamae; H. Katagiri; J. Kataoka; N. Kawai; M. Kerr; J. Knödlseder; M. L. Kocian; M. Kramer; F. Kuehn; M. Kuss; J. Lande; L. Latronico; S. H. Lee; M. Lemoine-Goumard; F. Longo; F. Loparco; B. Lott; M. N. Lovellette; P. Lubrano; A. G. Lyne; A. Makeev; M. Marelli; M. N. Mazziotta; J. E. McEnery; C. Meurer; P. F. Michelson; W. Mitthumsiri; T. Mizuno; A. A. Moiseev; C. Monte; M. E. Monzani; E. Moretti; A. Morselli; I. V. Moskalenko; S. Murgia; T. Nakamori; P. L. Nolan; J. P. Norris; A. Noutsos; E. Nuss; T. Ohsugi; N. Omodei; E. Orlando; J. F. Ormes; M. Ozaki; D. Paneque; J. H. Panetta; D. Parent; V. Pelassa; M. Pepe; M. Pesce-Rollins; M. Pierbattista; F. Piron; T. A. Porter; S. Rainò; R. Rando; P. S. Ray; M. Razzano; A. Reimer; O. Reimer; T. Reposeur; S. Ritz; L. S. Rochester; A. Y. Rodriguez; R. W. Romani; M. Roth; F. Ryde; H. F.W. Sadrozinski; D. Sanchez; A. Sander; P. M.Saz Parkinson; J. D. Scargle; C. Sgrò; E. J. Siskind; D. A. Smith; P. D. Smith; G. Spandre; P. Spinelli; B. W. Stappers; M. S. Strickman; D. J. Suson; H. Tajima; H. Takahashi; T. Tanaka; J. B. Thayer; J. G. Thayer; G. Theureau; D. J. Thompson; S. E. Thorsett; L. Tibaldo; D. F. Torres; G. Tosti; A. Tramacere; Y. Uchiyama; T. L. Usher; A. Van Etten; V. Vasileiou; N. Vilchez; V. Vitale; A. P. Waite; E. Wallace; P. Wang; K. Watters; P. Weltevrede; B. L. Winer; K. S. Wood; T. Ylinen; M. Ziegler

doi:10.1088/0004-637X/708/2/1254

Fermi large area telescope observations of the crab pulsar and nebula

A. A. Abdo, M. Ackermann, M. Ajello, W. B. Atwood, M. Axelsson, L. Baldini, J. Ballet, G. Barbiellini, M. G. Baring, D. Bastieri, K. Bechtol, R. Bellazzini, B. Berenji, R. D. Blandford, E. D. Bloom, E. Bonamente, A. W. Borgland, J. Bregeon, A. Brez, M. BrigidaP. Bruel, T. H. Burnett, G. A. Caliandro, R. A. Cameron, F. Camilo, P. A. Caraveo, J. M. Casandjian, C. Cecchi, Ö Çelik, A. Chekhtman, C. C. Cheung, J. Chiang, S. Ciprini, R. Claus, I. Cognard, J. Cohen-Tanugi, L. R. Cominsky, J. Conrad, C. D. Dermer, A. De Angelis, A. De Luca, F. De Palma, S. W. Digel, E. Do Couto E Silva, P. S. Drell, R. Dubois, D. Dumora, C. Espinoza, C. Farnier, C. Favuzzi, S. J. Fegan, E. C. Ferrara, W. B. Focke, M. Frailis, P. C.C. Freire, Y. Fukazawa, S. Funk, P. Fusco, F. Gargano, D. Gasparrini, N. Gehrels, S. Germani, G. Giavitto, B. Giebels, N. Giglietto, F. Giordano, T. Glanzman, G. Godfrey, I. A. Grenier, M. H. Grondin, J. E. Grove, L. Guillemot, S. Guiriec, Y. Hanabata, A. K. Harding, M. Hayashida, E. Hays, R. E. Hughes, G. Jóhannesson, A. S. Johnson, R. P. Johnson, T. J. Johnson, W. N. Johnson, S. Johnston, T. Kamae, H. Katagiri, J. Kataoka, N. Kawai, M. Kerr, J. Knödlseder, M. L. Kocian, M. Kramer, F. Kuehn, M. Kuss, J. Lande, L. Latronico, S. H. Lee, M. Lemoine-Goumard, F. Longo, F. Loparco, B. Lott, M. N. Lovellette, P. Lubrano, A. G. Lyne, A. Makeev, M. Marelli, M. N. Mazziotta, J. E. McEnery, C. Meurer, P. F. Michelson, W. Mitthumsiri, T. Mizuno, A. A. Moiseev, C. Monte, M. E. Monzani, E. Moretti, A. Morselli, I. V. Moskalenko, S. Murgia, T. Nakamori, P. L. Nolan, J. P. Norris, A. Noutsos, E. Nuss, T. Ohsugi, N. Omodei, E. Orlando, J. F. Ormes, M. Ozaki, D. Paneque, J. H. Panetta, D. Parent, V. Pelassa, M. Pepe, M. Pesce-Rollins, M. Pierbattista, F. Piron, T. A. Porter, S. Rainò, R. Rando, P. S. Ray, M. Razzano, A. Reimer, O. Reimer, T. Reposeur, S. Ritz, L. S. Rochester, A. Y. Rodriguez, R. W. Romani, M. Roth, F. Ryde, H. F.W. Sadrozinski, D. Sanchez, A. Sander, P. M.Saz Parkinson, J. D. Scargle, C. Sgrò, E. J. Siskind, D. A. Smith, P. D. Smith, G. Spandre, P. Spinelli, B. W. Stappers, M. S. Strickman, D. J. Suson, H. Tajima, H. Takahashi, T. Tanaka, J. B. Thayer, J. G. Thayer, G. Theureau, D. J. Thompson, S. E. Thorsett, L. Tibaldo, D. F. Torres, G. Tosti, A. Tramacere, Y. Uchiyama, T. L. Usher, A. Van Etten, V. Vasileiou, N. Vilchez, V. Vitale, A. P. Waite, E. Wallace, P. Wang, K. Watters, P. Weltevrede, B. L. Winer, K. S. Wood, T. Ylinen, M. Ziegler

Research output: Contribution to journal › Article › peer-review

277 Scopus citations

Abstract

We report on γ-ray observations of the Crab Pulsar and Nebula using 8 months of survey data with the Fermi Large Area Telescope (LAT). The high quality light curve obtained using the ephemeris provided by the Nançay and Jodrell Bank radio telescopes shows two main peaks stable in phase with energy. The first γ-ray peak leads the radio main pulse by (281 ±12 ± 21) μs, giving new constraints on the production site of non-thermal emission in pulsar magnetospheres. The first uncertainty is due to γ-ray statistics, and the second arises from the rotation parameters. The improved sensitivity and the unprecedented statistics afforded by the LAT enable precise measurement of the Crab Pulsar spectral parameters: cut-off energy at E_c = (5.8 ± 0.5 ± 1.2) GeV, spectral index of Γ = (1.97 ± 0.02 ± 0.06) and integral photon flux above 100 MeV of (2.09 ± 0.03 ± 0.18) × 10^-6 cm^-2 s^-1. The first errors represent the statistical error on the fit parameters, while the second ones are the systematic uncertainties. Pulsed γ-ray photons are observed up to 20 GeV which precludes emission near the stellar surface, below altitudes of around 4-5 stellar radii in phase intervals encompassing the two main peaks. A detailed phase-resolved spectral analysis is also performed: the hardest emission from the Crab Pulsar comes from the bridge region between the two γ-ray peaks while the softest comes from the falling edge of the second peak. The spectrum of the nebula in the energy range 100 MeV-300 GeV is well described by the sum of two power laws of indices Γ_sync = (3.99 ± 0.12 ± 0.08) and Γ_IC = (1.64 ± 0.05 ± 0.07), corresponding to the falling edge of the synchrotron and the rising edge of the inverse Compton (IC) components, respectively. This latter, which links up naturally with the spectral data points of Cherenkov experiments, is well reproduced via IC scattering from standard magnetohydrodynamic nebula models, and does not require any additional radiation mechanism.

Original language	English
Pages (from-to)	1254-1267
Number of pages	14
Journal	Astrophysical Journal
Volume	708
Issue number	2
DOIs	https://doi.org/10.1088/0004-637X/708/2/1254
State	Published - 2010
Externally published	Yes

Keywords

Gamma rays: observations
ISM: individual (Crab Nebula)
Pulsars: individual (Crab)
Supernova remnants

Access to Document

10.1088/0004-637X/708/2/1254

Cite this

Abdo, A. A., Ackermann, M., Ajello, M., Atwood, W. B., Axelsson, M., Baldini, L., Ballet, J., Barbiellini, G., Baring, M. G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Bregeon, J., Brez, A., ... Ziegler, M. (2010). Fermi large area telescope observations of the crab pulsar and nebula. Astrophysical Journal, 708(2), 1254-1267. https://doi.org/10.1088/0004-637X/708/2/1254

@article{e3281a147ccb4e9191c074ffe71324b6,

title = "Fermi large area telescope observations of the crab pulsar and nebula",

abstract = "We report on γ-ray observations of the Crab Pulsar and Nebula using 8 months of survey data with the Fermi Large Area Telescope (LAT). The high quality light curve obtained using the ephemeris provided by the Nan{\c c}ay and Jodrell Bank radio telescopes shows two main peaks stable in phase with energy. The first γ-ray peak leads the radio main pulse by (281 ±12 ± 21) μs, giving new constraints on the production site of non-thermal emission in pulsar magnetospheres. The first uncertainty is due to γ-ray statistics, and the second arises from the rotation parameters. The improved sensitivity and the unprecedented statistics afforded by the LAT enable precise measurement of the Crab Pulsar spectral parameters: cut-off energy at Ec = (5.8 ± 0.5 ± 1.2) GeV, spectral index of Γ = (1.97 ± 0.02 ± 0.06) and integral photon flux above 100 MeV of (2.09 ± 0.03 ± 0.18) × 10-6 cm-2 s-1. The first errors represent the statistical error on the fit parameters, while the second ones are the systematic uncertainties. Pulsed γ-ray photons are observed up to 20 GeV which precludes emission near the stellar surface, below altitudes of around 4-5 stellar radii in phase intervals encompassing the two main peaks. A detailed phase-resolved spectral analysis is also performed: the hardest emission from the Crab Pulsar comes from the bridge region between the two γ-ray peaks while the softest comes from the falling edge of the second peak. The spectrum of the nebula in the energy range 100 MeV-300 GeV is well described by the sum of two power laws of indices Γsync = (3.99 ± 0.12 ± 0.08) and ΓIC = (1.64 ± 0.05 ± 0.07), corresponding to the falling edge of the synchrotron and the rising edge of the inverse Compton (IC) components, respectively. This latter, which links up naturally with the spectral data points of Cherenkov experiments, is well reproduced via IC scattering from standard magnetohydrodynamic nebula models, and does not require any additional radiation mechanism.",

keywords = "Gamma rays: observations, ISM: individual (Crab Nebula), Pulsars: individual (Crab), Supernova remnants",

author = "Abdo, {A. A.} and M. Ackermann and M. Ajello and Atwood, {W. B.} and M. Axelsson and L. Baldini and J. Ballet and G. Barbiellini and Baring, {M. G.} and D. Bastieri and K. Bechtol and R. Bellazzini and B. Berenji and Blandford, {R. D.} and Bloom, {E. D.} and E. Bonamente and Borgland, {A. W.} and J. Bregeon and A. Brez and M. Brigida and P. Bruel and Burnett, {T. H.} and Caliandro, {G. A.} and Cameron, {R. A.} and F. Camilo and Caraveo, {P. A.} and Casandjian, {J. M.} and C. Cecchi and {\"O} {\c C}elik and A. Chekhtman and Cheung, {C. C.} and J. Chiang and S. Ciprini and R. Claus and I. Cognard and J. Cohen-Tanugi and Cominsky, {L. R.} and J. Conrad and Dermer, {C. D.} and {De Angelis}, A. and {De Luca}, A. and {De Palma}, F. and Digel, {S. W.} and {Do Couto E Silva}, E. and Drell, {P. S.} and R. Dubois and D. Dumora and C. Espinoza and C. Farnier and C. Favuzzi and Fegan, {S. J.} and Ferrara, {E. C.} and Focke, {W. B.} and M. Frailis and Freire, {P. C.C.} and Y. Fukazawa and S. Funk and P. Fusco and F. Gargano and D. Gasparrini and N. Gehrels and S. Germani and G. Giavitto and B. Giebels and N. Giglietto and F. Giordano and T. Glanzman and G. Godfrey and Grenier, {I. A.} and Grondin, {M. H.} and Grove, {J. E.} and L. Guillemot and S. Guiriec and Y. Hanabata and Harding, {A. K.} and M. Hayashida and E. Hays and Hughes, {R. E.} and G. J{\'o}hannesson and Johnson, {A. S.} and Johnson, {R. P.} and Johnson, {T. J.} and Johnson, {W. N.} and S. Johnston and T. Kamae and H. Katagiri and J. Kataoka and N. Kawai and M. Kerr and J. Kn{\"o}dlseder and Kocian, {M. L.} and M. Kramer and F. Kuehn and M. Kuss and J. Lande and L. Latronico and Lee, {S. H.} and M. Lemoine-Goumard and F. Longo and F. Loparco and B. Lott and Lovellette, {M. N.} and P. Lubrano and Lyne, {A. G.} and A. Makeev and M. Marelli and Mazziotta, {M. N.} and McEnery, {J. E.} and C. Meurer and Michelson, {P. F.} and W. Mitthumsiri and T. Mizuno and Moiseev, {A. A.} and C. Monte and Monzani, {M. E.} and E. Moretti and A. Morselli and Moskalenko, {I. V.} and S. Murgia and T. Nakamori and Nolan, {P. L.} and Norris, {J. P.} and A. Noutsos and E. Nuss and T. Ohsugi and N. Omodei and E. Orlando and Ormes, {J. F.} and M. Ozaki and D. Paneque and Panetta, {J. H.} and D. Parent and V. Pelassa and M. Pepe and M. Pesce-Rollins and M. Pierbattista and F. Piron and Porter, {T. A.} and S. Rain{\`o} and R. Rando and Ray, {P. S.} and M. Razzano and A. Reimer and O. Reimer and T. Reposeur and S. Ritz and Rochester, {L. S.} and Rodriguez, {A. Y.} and Romani, {R. W.} and M. Roth and F. Ryde and Sadrozinski, {H. F.W.} and D. Sanchez and A. Sander and Parkinson, {P. M.Saz} and Scargle, {J. D.} and C. Sgr{\`o} and Siskind, {E. J.} and Smith, {D. A.} and Smith, {P. D.} and G. Spandre and P. Spinelli and Stappers, {B. W.} and Strickman, {M. S.} and Suson, {D. J.} and H. Tajima and H. Takahashi and T. Tanaka and Thayer, {J. B.} and Thayer, {J. G.} and G. Theureau and Thompson, {D. J.} and Thorsett, {S. E.} and L. Tibaldo and Torres, {D. F.} and G. Tosti and A. Tramacere and Y. Uchiyama and Usher, {T. L.} and {Van Etten}, A. and V. Vasileiou and N. Vilchez and V. Vitale and Waite, {A. P.} and E. Wallace and P. Wang and K. Watters and P. Weltevrede and Winer, {B. L.} and Wood, {K. S.} and T. Ylinen and M. Ziegler",

year = "2010",

doi = "10.1088/0004-637X/708/2/1254",

language = "English",

volume = "708",

pages = "1254--1267",

journal = "Astrophysical Journal",

issn = "0004-637X",

publisher = "American Astronomical Society",

number = "2",

}

Abdo, AA, Ackermann, M, Ajello, M, Atwood, WB, Axelsson, M, Baldini, L, Ballet, J, Barbiellini, G, Baring, MG, Bastieri, D, Bechtol, K, Bellazzini, R, Berenji, B, Blandford, RD, Bloom, ED, Bonamente, E, Borgland, AW, Bregeon, J, Brez, A, Brigida, M, Bruel, P, Burnett, TH, Caliandro, GA, Cameron, RA, Camilo, F, Caraveo, PA, Casandjian, JM, Cecchi, C, Çelik, Ö, Chekhtman, A, Cheung, CC, Chiang, J, Ciprini, S, Claus, R, Cognard, I, Cohen-Tanugi, J, Cominsky, LR, Conrad, J, Dermer, CD, De Angelis, A, De Luca, A, De Palma, F, Digel, SW, Do Couto E Silva, E, Drell, PS, Dubois, R, Dumora, D, Espinoza, C, Farnier, C, Favuzzi, C, Fegan, SJ, Ferrara, EC, Focke, WB, Frailis, M, Freire, PCC, Fukazawa, Y, Funk, S, Fusco, P, Gargano, F, Gasparrini, D, Gehrels, N, Germani, S, Giavitto, G, Giebels, B, Giglietto, N, Giordano, F, Glanzman, T, Godfrey, G, Grenier, IA, Grondin, MH, Grove, JE, Guillemot, L, Guiriec, S, Hanabata, Y, Harding, AK, Hayashida, M, Hays, E, Hughes, RE, Jóhannesson, G, Johnson, AS, Johnson, RP, Johnson, TJ, Johnson, WN, Johnston, S, Kamae, T, Katagiri, H, Kataoka, J, Kawai, N, Kerr, M, Knödlseder, J, Kocian, ML, Kramer, M, Kuehn, F, Kuss, M, Lande, J, Latronico, L, Lee, SH, Lemoine-Goumard, M, Longo, F, Loparco, F, Lott, B, Lovellette, MN, Lubrano, P, Lyne, AG, Makeev, A, Marelli, M, Mazziotta, MN, McEnery, JE, Meurer, C, Michelson, PF, Mitthumsiri, W, Mizuno, T, Moiseev, AA, Monte, C, Monzani, ME, Moretti, E, Morselli, A, Moskalenko, IV, Murgia, S, Nakamori, T, Nolan, PL, Norris, JP, Noutsos, A, 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, Pierbattista, M, Piron, F, Porter, TA, Rainò, S, Rando, R, Ray, PS, Razzano, M, Reimer, A, Reimer, O, Reposeur, T, Ritz, S, Rochester, LS, Rodriguez, AY, Romani, RW, Roth, M, Ryde, F, Sadrozinski, HFW, Sanchez, D, Sander, A, Parkinson, PMS, Scargle, JD, Sgrò, C, Siskind, EJ, Smith, DA, Smith, PD, Spandre, G, Spinelli, P, Stappers, BW, Strickman, MS, Suson, DJ, Tajima, H, Takahashi, H, Tanaka, T, Thayer, JB, Thayer, JG, Theureau, G, Thompson, DJ, Thorsett, SE, Tibaldo, L, Torres, DF, Tosti, G, Tramacere, A, Uchiyama, Y, Usher, TL, Van Etten, A, Vasileiou, V, Vilchez, N, Vitale, V, Waite, AP, Wallace, E, Wang, P, Watters, K, Weltevrede, P, Winer, BL, Wood, KS, Ylinen, T & Ziegler, M 2010, 'Fermi large area telescope observations of the crab pulsar and nebula', Astrophysical Journal, vol. 708, no. 2, pp. 1254-1267. https://doi.org/10.1088/0004-637X/708/2/1254

TY - JOUR

T1 - Fermi large area telescope observations of the crab pulsar and nebula

AU - Abdo, A. A.

AU - Ackermann, M.

AU - Ajello, M.

AU - Atwood, W. B.

AU - Axelsson, M.

AU - Baldini, L.

AU - Ballet, J.

AU - Barbiellini, G.

AU - Baring, M. G.

AU - Bastieri, D.

AU - Bechtol, K.

AU - Bellazzini, R.

AU - Berenji, B.

AU - Blandford, R. D.

AU - Bloom, E. D.

AU - Bonamente, E.

AU - Borgland, A. W.

AU - Bregeon, J.

AU - Brez, A.

AU - Brigida, M.

AU - Bruel, P.

AU - Burnett, T. H.

AU - Caliandro, G. A.

AU - Cameron, R. A.

AU - Camilo, F.

AU - Caraveo, P. A.

AU - Casandjian, J. M.

AU - Cecchi, C.

AU - Çelik, Ö

AU - Chekhtman, A.

AU - Cheung, C. C.

AU - Chiang, J.

AU - Ciprini, S.

AU - Claus, R.

AU - Cognard, I.

AU - Cohen-Tanugi, J.

AU - Cominsky, L. R.

AU - Conrad, J.

AU - Dermer, C. D.

AU - De Angelis, A.

AU - De Luca, A.

AU - De Palma, F.

AU - Digel, S. W.

AU - Do Couto E Silva, E.

AU - Drell, P. S.

AU - Dubois, R.

AU - Dumora, D.

AU - Espinoza, C.

AU - Farnier, C.

AU - Favuzzi, C.

AU - Fegan, S. J.

AU - Ferrara, E. C.

AU - Focke, W. B.

AU - Frailis, M.

AU - Freire, P. C.C.

AU - Fukazawa, Y.

AU - Funk, S.

AU - Fusco, P.

AU - Gargano, F.

AU - Gasparrini, D.

AU - Gehrels, N.

AU - Germani, S.

AU - Giavitto, G.

AU - Giebels, B.

AU - Giglietto, N.

AU - Giordano, F.

AU - Glanzman, T.

AU - Godfrey, G.

AU - Grenier, I. A.

AU - Grondin, M. H.

AU - Grove, J. E.

AU - Guillemot, L.

AU - Guiriec, S.

AU - Hanabata, Y.

AU - Harding, A. K.

AU - Hayashida, M.

AU - Hays, E.

AU - Hughes, R. E.

AU - Jóhannesson, G.

AU - Johnson, A. S.

AU - Johnson, R. P.

AU - Johnson, T. J.

AU - Johnson, W. N.

AU - Johnston, S.

AU - Kamae, T.

AU - Katagiri, H.

AU - Kataoka, J.

AU - Kawai, N.

AU - Kerr, M.

AU - Knödlseder, J.

AU - Kocian, M. L.

AU - Kramer, M.

AU - Kuehn, F.

AU - Kuss, M.

AU - Lande, J.

AU - Latronico, L.

AU - Lee, S. H.

AU - Lemoine-Goumard, M.

AU - Longo, F.

AU - Loparco, F.

AU - Lott, B.

AU - Lovellette, M. N.

AU - Lubrano, P.

AU - Lyne, A. G.

AU - Makeev, A.

AU - Marelli, M.

AU - Mazziotta, M. N.

AU - McEnery, J. E.

AU - Meurer, C.

AU - Michelson, P. F.

AU - Mitthumsiri, W.

AU - Mizuno, T.

AU - Moiseev, A. A.

AU - Monte, C.

AU - Monzani, M. E.

AU - Moretti, E.

AU - Morselli, A.

AU - Moskalenko, I. V.

AU - Murgia, S.

AU - Nakamori, T.

AU - Nolan, P. L.

AU - Norris, J. P.

AU - Noutsos, A.

AU - Nuss, E.

AU - Ohsugi, T.

AU - Omodei, N.

AU - Orlando, E.

AU - Ormes, J. F.

AU - Ozaki, M.

AU - Paneque, D.

AU - Panetta, J. H.

AU - Parent, D.

AU - Pelassa, V.

AU - Pepe, M.

AU - Pesce-Rollins, M.

AU - Pierbattista, M.

AU - Piron, F.

AU - Porter, T. A.

AU - Rainò, S.

AU - Rando, R.

AU - Ray, P. S.

AU - Razzano, M.

AU - Reimer, A.

AU - Reimer, O.

AU - Reposeur, T.

AU - Ritz, S.

AU - Rochester, L. S.

AU - Rodriguez, A. Y.

AU - Romani, R. W.

AU - Roth, M.

AU - Ryde, F.

AU - Sadrozinski, H. F.W.

AU - Sanchez, D.

AU - Sander, A.

AU - Parkinson, P. M.Saz

AU - Scargle, J. D.

AU - Sgrò, C.

AU - Siskind, E. J.

AU - Smith, D. A.

AU - Smith, P. D.

AU - Spandre, G.

AU - Spinelli, P.

AU - Stappers, B. W.

AU - Strickman, M. S.

AU - Suson, D. J.

AU - Tajima, H.

AU - Takahashi, H.

AU - Tanaka, T.

AU - Thayer, J. B.

AU - Thayer, J. G.

AU - Theureau, G.

AU - Thompson, D. J.

AU - Thorsett, S. E.

AU - Tibaldo, L.

AU - Torres, D. F.

AU - Tosti, G.

AU - Tramacere, A.

AU - Uchiyama, Y.

AU - Usher, T. L.

AU - Van Etten, A.

AU - Vasileiou, V.

AU - Vilchez, N.

AU - Vitale, V.

AU - Waite, A. P.

AU - Wallace, E.

AU - Wang, P.

AU - Watters, K.

AU - Weltevrede, P.

AU - Winer, B. L.

AU - Wood, K. S.

AU - Ylinen, T.

AU - Ziegler, M.

PY - 2010

Y1 - 2010

N2 - We report on γ-ray observations of the Crab Pulsar and Nebula using 8 months of survey data with the Fermi Large Area Telescope (LAT). The high quality light curve obtained using the ephemeris provided by the Nançay and Jodrell Bank radio telescopes shows two main peaks stable in phase with energy. The first γ-ray peak leads the radio main pulse by (281 ±12 ± 21) μs, giving new constraints on the production site of non-thermal emission in pulsar magnetospheres. The first uncertainty is due to γ-ray statistics, and the second arises from the rotation parameters. The improved sensitivity and the unprecedented statistics afforded by the LAT enable precise measurement of the Crab Pulsar spectral parameters: cut-off energy at Ec = (5.8 ± 0.5 ± 1.2) GeV, spectral index of Γ = (1.97 ± 0.02 ± 0.06) and integral photon flux above 100 MeV of (2.09 ± 0.03 ± 0.18) × 10-6 cm-2 s-1. The first errors represent the statistical error on the fit parameters, while the second ones are the systematic uncertainties. Pulsed γ-ray photons are observed up to 20 GeV which precludes emission near the stellar surface, below altitudes of around 4-5 stellar radii in phase intervals encompassing the two main peaks. A detailed phase-resolved spectral analysis is also performed: the hardest emission from the Crab Pulsar comes from the bridge region between the two γ-ray peaks while the softest comes from the falling edge of the second peak. The spectrum of the nebula in the energy range 100 MeV-300 GeV is well described by the sum of two power laws of indices Γsync = (3.99 ± 0.12 ± 0.08) and ΓIC = (1.64 ± 0.05 ± 0.07), corresponding to the falling edge of the synchrotron and the rising edge of the inverse Compton (IC) components, respectively. This latter, which links up naturally with the spectral data points of Cherenkov experiments, is well reproduced via IC scattering from standard magnetohydrodynamic nebula models, and does not require any additional radiation mechanism.

AB - We report on γ-ray observations of the Crab Pulsar and Nebula using 8 months of survey data with the Fermi Large Area Telescope (LAT). The high quality light curve obtained using the ephemeris provided by the Nançay and Jodrell Bank radio telescopes shows two main peaks stable in phase with energy. The first γ-ray peak leads the radio main pulse by (281 ±12 ± 21) μs, giving new constraints on the production site of non-thermal emission in pulsar magnetospheres. The first uncertainty is due to γ-ray statistics, and the second arises from the rotation parameters. The improved sensitivity and the unprecedented statistics afforded by the LAT enable precise measurement of the Crab Pulsar spectral parameters: cut-off energy at Ec = (5.8 ± 0.5 ± 1.2) GeV, spectral index of Γ = (1.97 ± 0.02 ± 0.06) and integral photon flux above 100 MeV of (2.09 ± 0.03 ± 0.18) × 10-6 cm-2 s-1. The first errors represent the statistical error on the fit parameters, while the second ones are the systematic uncertainties. Pulsed γ-ray photons are observed up to 20 GeV which precludes emission near the stellar surface, below altitudes of around 4-5 stellar radii in phase intervals encompassing the two main peaks. A detailed phase-resolved spectral analysis is also performed: the hardest emission from the Crab Pulsar comes from the bridge region between the two γ-ray peaks while the softest comes from the falling edge of the second peak. The spectrum of the nebula in the energy range 100 MeV-300 GeV is well described by the sum of two power laws of indices Γsync = (3.99 ± 0.12 ± 0.08) and ΓIC = (1.64 ± 0.05 ± 0.07), corresponding to the falling edge of the synchrotron and the rising edge of the inverse Compton (IC) components, respectively. This latter, which links up naturally with the spectral data points of Cherenkov experiments, is well reproduced via IC scattering from standard magnetohydrodynamic nebula models, and does not require any additional radiation mechanism.

KW - Gamma rays: observations

KW - ISM: individual (Crab Nebula)

KW - Pulsars: individual (Crab)

KW - Supernova remnants

UR - http://www.scopus.com/inward/record.url?scp=77949386414&partnerID=8YFLogxK

U2 - 10.1088/0004-637X/708/2/1254

DO - 10.1088/0004-637X/708/2/1254

M3 - Article

AN - SCOPUS:77949386414

SN - 0004-637X

VL - 708

SP - 1254

EP - 1267

JO - Astrophysical Journal

JF - Astrophysical Journal

IS - 2

ER -

Fermi large area telescope observations of the crab pulsar and nebula

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