Spectrum of the isotropic diffuse gamma-ray emission derived from first-year fermi large area telescope data

A. A. Abdo; M. Ackermann; M. Ajello; W. B. Atwood; L. Baldini; J. Ballet; G. Barbiellini; D. Bastieri; B. M. Baughman; 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; S. Buson; G. A. Caliandro; R. A. Cameron; P. A. Caraveo; J. M. Casandjian; E. Cavazzuti; C. Cecchi; Ö Ö Çelik; E. Charles; A. Chekhtman; C. C. Cheung; J. Chiang; S. Ciprini; R. Claus; J. Cohen-Tanugi; L. R. Cominsky; J. Conrad; S. Cutini; C. D. Dermer; A. De Angelis; F. De Palma; S. W. Digel; G. Di Bernardo; E. Do Couto E Silva; P. S. Drell; A. Drlica-Wagner; R. Dubois; D. Dumora; C. Farnier; C. Favuzzi; S. J. Fegan; W. B. Focke; P. Fortin; M. Frailis; Y. Fukazawa; S. Funk; P. Fusco; D. Gaggero; F. Gargano; D. Gasparrini; N. Gehrels; S. Germani; B. Giebels; N. Giglietto; P. Giommi; F. Giordano; T. Glanzman; G. Godfrey; I. A. Grenier; M. H. Grondin; J. E. Grove; L. Guillemot; S. Guiriec; M. Gustafsson; Y. Hanabata; A. K. Harding; M. Hayashida; R. E. Hughes; R. Itoh; M. S. Jackson; G. Jóhannesson; A. S. Johnson; R. P. Johnson; T. J. Johnson; W. N. Johnson; T. Kamae; H. Katagiri; J. Kataoka; N. Kawai; M. Kerr; J. Knödlseder; M. L. Kocian; F. Kuehn; M. Kuss; J. Lande; L. Latronico; M. Lemoine-Goumard; F. Longo; F. Loparco; B. Lott; M. N. Lovellette; P. Lubrano; G. M. Madejski; A. Makeev; M. N. Mazziotta; W. McConville; J. E. McEnery; C. Meurer; P. F. Michelson; W. Mitthumsiri; T. Mizuno; A. A. Moiseev; C. Monte; M. E. Monzani; A. Morselli; I. V. Moskalenko; S. Murgia; P. L. Nolan; J. P. Norris; E. Nuss; T. Ohsugi; N. Omodei; E. Orlando; J. F. Ormes; D. Paneque; J. H. Panetta; D. Parent; V. Pelassa; M. Pepe; M. Pesce-Rollins; F. Piron; T. A. Porter; S. Rainò; R. Rando; M. Razzano; A. Reimer; O. Reimer; T. Reposeur; S. Ritz; L. S. Rochester; A. Y. Rodriguez; M. Roth; F. Ryde; H. F.W. Sadrozinski; D. Sanchez; A. Sander; P. M.Saz Parkinson; J. D. Scargle; A. Sellerholm; C. Sgrò; M. S. Shaw; E. J. Siskind; D. A. Smith; P. D. Smith; G. Spandre; P. Spinelli; J. L. Starck; M. S. Strickman; A. W. Strong; D. J. Suson; H. Tajima; H. Takahashi; T. Takahashi; T. Tanaka; J. B. Thayer; J. G. Thayer; D. J. Thompson; L. Tibaldo; D. F. Torres; G. Tosti; A. Tramacere; Y. Uchiyama; T. L. Usher; V. Vasileiou; N. Vilchez; V. Vitale; A. P. Waite; P. Wang; B. L. Winer; K. S. Wood; T. Ylinen; M. Ziegler

doi:10.1103/PhysRevLett.104.101101

Spectrum of the isotropic diffuse gamma-ray emission derived from first-year fermi large area telescope data

A. A. Abdo^*, M. Ackermann, M. Ajello, W. B. Atwood, L. Baldini, J. Ballet, G. Barbiellini, D. Bastieri, B. M. Baughman, K. Bechtol, R. Bellazzini, B. Berenji, R. D. Blandford, E. D. Bloom, E. Bonamente, A. W. Borgland, J. Bregeon, A. Brez, M. Brigida, P. BruelT. H. Burnett, S. Buson, G. A. Caliandro, R. A. Cameron, P. A. Caraveo, J. M. Casandjian, E. Cavazzuti, C. Cecchi, Ö Ö Çelik, E. Charles, A. Chekhtman, C. C. Cheung, J. Chiang, S. Ciprini, R. Claus, J. Cohen-Tanugi, L. R. Cominsky, J. Conrad, S. Cutini, C. D. Dermer, A. De Angelis, F. De Palma, S. W. Digel, G. Di Bernardo, E. Do Couto E Silva, P. S. Drell, A. Drlica-Wagner, R. Dubois, D. Dumora, C. Farnier, C. Favuzzi, S. J. Fegan, W. B. Focke, P. Fortin, M. Frailis, Y. Fukazawa, S. Funk, P. Fusco, D. Gaggero, F. Gargano, D. Gasparrini, N. Gehrels, S. Germani, B. Giebels, N. Giglietto, P. Giommi, F. Giordano, T. Glanzman, G. Godfrey, I. A. Grenier, M. H. Grondin, J. E. Grove, L. Guillemot, S. Guiriec, M. Gustafsson, Y. Hanabata, A. K. Harding, M. Hayashida, R. E. Hughes, R. Itoh, M. S. Jackson, G. Jóhannesson, A. S. Johnson, R. P. Johnson, T. J. Johnson, W. N. Johnson, T. Kamae, H. Katagiri, J. Kataoka, N. Kawai, M. Kerr, J. Knödlseder, M. L. Kocian, F. Kuehn, M. Kuss, J. Lande, L. Latronico, M. Lemoine-Goumard, F. Longo, F. Loparco, B. Lott, M. N. Lovellette, P. Lubrano, G. M. Madejski, A. Makeev, M. N. Mazziotta, W. McConville, J. E. McEnery, C. Meurer, P. F. Michelson, W. Mitthumsiri, T. Mizuno, A. A. Moiseev, C. Monte, M. E. Monzani, A. Morselli, I. V. Moskalenko, S. Murgia, P. L. Nolan, J. P. Norris, E. Nuss, T. Ohsugi, N. Omodei, E. Orlando, J. F. Ormes, D. Paneque, J. H. Panetta, D. Parent, V. Pelassa, M. Pepe, M. Pesce-Rollins, F. Piron, T. A. Porter, S. Rainò, R. Rando, M. Razzano, A. Reimer, O. Reimer, T. Reposeur, S. Ritz, L. S. Rochester, A. Y. Rodriguez, M. Roth, F. Ryde, H. F.W. Sadrozinski, D. Sanchez, A. Sander, P. M.Saz Parkinson, J. D. Scargle, A. Sellerholm, C. Sgrò, M. S. Shaw, E. J. Siskind, D. A. Smith, P. D. Smith, G. Spandre, P. Spinelli, J. L. Starck, M. S. Strickman, A. W. Strong, D. J. Suson, H. Tajima, H. Takahashi, T. Takahashi, T. Tanaka, J. B. Thayer, J. G. Thayer, D. J. Thompson, L. Tibaldo, D. F. Torres, G. Tosti, A. Tramacere, Y. Uchiyama, T. L. Usher, V. Vasileiou, N. Vilchez, V. Vitale, A. P. Waite, P. Wang, B. L. Winer, K. S. Wood, T. Ylinen, M. Ziegler

^*Corresponding author for this work

School of Advanced Science and Engineering

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

471 Citations (Scopus)

Abstract

We report on the first Fermi Large Area Telescope (LAT) measurements of the so-called "extragalactic" diffuse γ-ray emission (EGB). This component of the diffuse γ-ray emission is generally considered to have an isotropic or nearly isotropic distribution on the sky with diverse contributions discussed in the literature. The derivation of the EGB is based on detailed modeling of the bright foreground diffuse Galactic γ-ray emission, the detected LAT sources, and the solar γ-ray emission. We find the spectrum of the EGB is consistent with a power law with a differential spectral index γ=2.41±0.05 and intensity I(>100MeV)=(1. 03±0.17)×10^-5cm^-2s^-1sr ^-1, where the error is systematics dominated. Our EGB spectrum is featureless, less intense, and softer than that derived from EGRET data.

Original language	English
Article number	101101
Journal	Physical Review Letters
Volume	104
Issue number	10
DOIs	https://doi.org/10.1103/PhysRevLett.104.101101
Publication status	Published - 2010 Mar 8

ASJC Scopus subject areas

Physics and Astronomy(all)

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10.1103/PhysRevLett.104.101101

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Abdo, A. A., Ackermann, M., Ajello, M., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Baughman, B. M., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Bregeon, J., Brez, A., Brigida, M., ... Ziegler, M. (2010). Spectrum of the isotropic diffuse gamma-ray emission derived from first-year fermi large area telescope data. Physical Review Letters, 104(10), [101101]. https://doi.org/10.1103/PhysRevLett.104.101101

Abdo, AA, Ackermann, M, Ajello, M, Atwood, WB, Baldini, L, Ballet, J, Barbiellini, G, Bastieri, D, Baughman, BM, Bechtol, K, Bellazzini, R, Berenji, B, Blandford, RD, Bloom, ED, Bonamente, E, Borgland, AW, Bregeon, J, Brez, A, Brigida, M, Bruel, P, Burnett, TH, Buson, S, Caliandro, GA, Cameron, RA, Caraveo, PA, Casandjian, JM, Cavazzuti, E, Cecchi, C, Çelik, ÖÖ, Charles, E, Chekhtman, A, Cheung, CC, Chiang, J, Ciprini, S, Claus, R, Cohen-Tanugi, J, Cominsky, LR, Conrad, J, Cutini, S, Dermer, CD, De Angelis, A, De Palma, F, Digel, SW, Di Bernardo, G, E Silva, EDC, Drell, PS, Drlica-Wagner, A, Dubois, R, Dumora, D, Farnier, C, Favuzzi, C, Fegan, SJ, Focke, WB, Fortin, P, Frailis, M, Fukazawa, Y, Funk, S, Fusco, P, Gaggero, D, Gargano, F, Gasparrini, D, Gehrels, N, Germani, S, Giebels, B, Giglietto, N, Giommi, P, Giordano, F, Glanzman, T, Godfrey, G, Grenier, IA, Grondin, MH, Grove, JE, Guillemot, L, Guiriec, S, Gustafsson, M, Hanabata, Y, Harding, AK, Hayashida, M, Hughes, RE, Itoh, R, Jackson, MS, Jóhannesson, G, Johnson, AS, Johnson, RP, Johnson, TJ, Johnson, WN, Kamae, T, Katagiri, H, Kataoka, J, Kawai, N, Kerr, M, Knödlseder, J, Kocian, ML, Kuehn, F, Kuss, M, Lande, J, Latronico, L, Lemoine-Goumard, M, Longo, F, Loparco, F, Lott, B, Lovellette, MN, Lubrano, P, Madejski, GM, Makeev, A, Mazziotta, MN, McConville, W, McEnery, JE, Meurer, C, Michelson, PF, Mitthumsiri, W, Mizuno, T, Moiseev, AA, Monte, C, Monzani, ME, Morselli, A, Moskalenko, IV, Murgia, S, Nolan, PL, Norris, JP, Nuss, E, Ohsugi, T, Omodei, N, Orlando, E, Ormes, JF, Paneque, D, Panetta, JH, Parent, D, Pelassa, V, Pepe, M, Pesce-Rollins, M, Piron, F, Porter, TA, Rainò, S, Rando, R, Razzano, M, Reimer, A, Reimer, O, Reposeur, T, Ritz, S, Rochester, LS, Rodriguez, AY, Roth, M, Ryde, F, Sadrozinski, HFW, Sanchez, D, Sander, A, Parkinson, PMS, Scargle, JD, Sellerholm, A, Sgrò, C, Shaw, MS, Siskind, EJ, Smith, DA, Smith, PD, Spandre, G, Spinelli, P, Starck, JL, Strickman, MS, Strong, AW, Suson, DJ, Tajima, H, Takahashi, H, Takahashi, T, Tanaka, T, Thayer, JB, Thayer, JG, Thompson, DJ, Tibaldo, L, Torres, DF, Tosti, G, Tramacere, A, Uchiyama, Y, Usher, TL, Vasileiou, V, Vilchez, N, Vitale, V, Waite, AP, Wang, P, Winer, BL, Wood, KS, Ylinen, T & Ziegler, M 2010, 'Spectrum of the isotropic diffuse gamma-ray emission derived from first-year fermi large area telescope data', Physical Review Letters, vol. 104, no. 10, 101101. https://doi.org/10.1103/PhysRevLett.104.101101

@article{2b9c7a538ade4782ada9c1a7dba5c627,

title = "Spectrum of the isotropic diffuse gamma-ray emission derived from first-year fermi large area telescope data",

abstract = "We report on the first Fermi Large Area Telescope (LAT) measurements of the so-called {"}extragalactic{"} diffuse γ-ray emission (EGB). This component of the diffuse γ-ray emission is generally considered to have an isotropic or nearly isotropic distribution on the sky with diverse contributions discussed in the literature. The derivation of the EGB is based on detailed modeling of the bright foreground diffuse Galactic γ-ray emission, the detected LAT sources, and the solar γ-ray emission. We find the spectrum of the EGB is consistent with a power law with a differential spectral index γ=2.41±0.05 and intensity I(>100MeV)=(1. 03±0.17)×10-5cm-2s-1sr -1, where the error is systematics dominated. Our EGB spectrum is featureless, less intense, and softer than that derived from EGRET data.",

author = "Abdo, {A. A.} and M. Ackermann and M. Ajello and Atwood, {W. B.} and L. Baldini and J. Ballet and G. Barbiellini and D. Bastieri and Baughman, {B. M.} 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 S. Buson and Caliandro, {G. A.} and Cameron, {R. A.} and Caraveo, {P. A.} and Casandjian, {J. M.} and E. Cavazzuti and C. Cecchi and {\c C}elik, {{\"O} {\"O}} and E. Charles and A. Chekhtman and Cheung, {C. C.} and J. Chiang and S. Ciprini and R. Claus and J. Cohen-Tanugi and Cominsky, {L. R.} and J. Conrad and S. Cutini and Dermer, {C. D.} and {De Angelis}, A. and {De Palma}, F. and Digel, {S. W.} and {Di Bernardo}, G. and {E Silva}, {E. Do Couto} and Drell, {P. S.} and A. Drlica-Wagner and R. Dubois and D. Dumora and C. Farnier and C. Favuzzi and Fegan, {S. J.} and Focke, {W. B.} and P. Fortin and M. Frailis and Y. Fukazawa and S. Funk and P. Fusco and D. Gaggero and F. Gargano and D. Gasparrini and N. Gehrels and S. Germani and B. Giebels and N. Giglietto and P. Giommi 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 M. Gustafsson and Y. Hanabata and Harding, {A. K.} and M. Hayashida and Hughes, {R. E.} and R. Itoh and Jackson, {M. S.} and G. J{\'o}hannesson and Johnson, {A. S.} and Johnson, {R. P.} and Johnson, {T. J.} and Johnson, {W. N.} 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 F. Kuehn and M. Kuss and J. Lande and L. Latronico and M. Lemoine-Goumard and F. Longo and F. Loparco and B. Lott and Lovellette, {M. N.} and P. Lubrano and Madejski, {G. M.} and A. Makeev and Mazziotta, {M. N.} and W. McConville 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 A. Morselli and Moskalenko, {I. V.} and S. Murgia and Nolan, {P. L.} and Norris, {J. P.} and E. Nuss and T. Ohsugi and N. Omodei and E. Orlando and Ormes, {J. F.} and D. Paneque and Panetta, {J. H.} and D. Parent and V. Pelassa and M. Pepe and M. Pesce-Rollins and F. Piron and Porter, {T. A.} and S. Rain{\`o} and R. Rando and M. Razzano and A. Reimer and O. Reimer and T. Reposeur and S. Ritz and Rochester, {L. S.} and Rodriguez, {A. Y.} 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 A. Sellerholm and C. Sgr{\`o} and Shaw, {M. S.} and Siskind, {E. J.} and Smith, {D. A.} and Smith, {P. D.} and G. Spandre and P. Spinelli and Starck, {J. L.} and Strickman, {M. S.} and Strong, {A. W.} and Suson, {D. J.} and H. Tajima and H. Takahashi and T. Takahashi and T. Tanaka and Thayer, {J. B.} and Thayer, {J. G.} and Thompson, {D. J.} and L. Tibaldo and Torres, {D. F.} and G. Tosti and A. Tramacere and Y. Uchiyama and Usher, {T. L.} and V. Vasileiou and N. Vilchez and V. Vitale and Waite, {A. P.} and P. Wang and Winer, {B. L.} and Wood, {K. S.} and T. Ylinen and M. Ziegler",

year = "2010",

month = mar,

day = "8",

doi = "10.1103/PhysRevLett.104.101101",

language = "English",

volume = "104",

journal = "Physical Review Letters",

issn = "0031-9007",

publisher = "American Physical Society",

number = "10",

}

TY - JOUR

T1 - Spectrum of the isotropic diffuse gamma-ray emission derived from first-year fermi large area telescope data

AU - Abdo, A. A.

AU - Ackermann, M.

AU - Ajello, M.

AU - Atwood, W. B.

AU - Baldini, L.

AU - Ballet, J.

AU - Barbiellini, G.

AU - Bastieri, D.

AU - Baughman, B. M.

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 - Buson, S.

AU - Caliandro, G. A.

AU - Cameron, R. A.

AU - Caraveo, P. A.

AU - Casandjian, J. M.

AU - Cavazzuti, E.

AU - Cecchi, C.

AU - Çelik, Ö Ö

AU - Charles, E.

AU - Chekhtman, A.

AU - Cheung, C. C.

AU - Chiang, J.

AU - Ciprini, S.

AU - Claus, R.

AU - Cohen-Tanugi, J.

AU - Cominsky, L. R.

AU - Conrad, J.

AU - Cutini, S.

AU - Dermer, C. D.

AU - De Angelis, A.

AU - De Palma, F.

AU - Digel, S. W.

AU - Di Bernardo, G.

AU - E Silva, E. Do Couto

AU - Drell, P. S.

AU - Drlica-Wagner, A.

AU - Dubois, R.

AU - Dumora, D.

AU - Farnier, C.

AU - Favuzzi, C.

AU - Fegan, S. J.

AU - Focke, W. B.

AU - Fortin, P.

AU - Frailis, M.

AU - Fukazawa, Y.

AU - Funk, S.

AU - Fusco, P.

AU - Gaggero, D.

AU - Gargano, F.

AU - Gasparrini, D.

AU - Gehrels, N.

AU - Germani, S.

AU - Giebels, B.

AU - Giglietto, N.

AU - Giommi, P.

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 - Gustafsson, M.

AU - Hanabata, Y.

AU - Harding, A. K.

AU - Hayashida, M.

AU - Hughes, R. E.

AU - Itoh, R.

AU - Jackson, M. S.

AU - Jóhannesson, G.

AU - Johnson, A. S.

AU - Johnson, R. P.

AU - Johnson, T. J.

AU - Johnson, W. N.

AU - Kamae, T.

AU - Katagiri, H.

AU - Kataoka, J.

AU - Kawai, N.

AU - Kerr, M.

AU - Knödlseder, J.

AU - Kocian, M. L.

AU - Kuehn, F.

AU - Kuss, M.

AU - Lande, J.

AU - Latronico, L.

AU - Lemoine-Goumard, M.

AU - Longo, F.

AU - Loparco, F.

AU - Lott, B.

AU - Lovellette, M. N.

AU - Lubrano, P.

AU - Madejski, G. M.

AU - Makeev, A.

AU - Mazziotta, M. N.

AU - McConville, W.

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 - Morselli, A.

AU - Moskalenko, I. V.

AU - Murgia, S.

AU - Nolan, P. L.

AU - Norris, J. P.

AU - Nuss, E.

AU - Ohsugi, T.

AU - Omodei, N.

AU - Orlando, E.

AU - Ormes, J. F.

AU - Paneque, D.

AU - Panetta, J. H.

AU - Parent, D.

AU - Pelassa, V.

AU - Pepe, M.

AU - Pesce-Rollins, M.

AU - Piron, F.

AU - Porter, T. A.

AU - Rainò, S.

AU - Rando, R.

AU - Razzano, M.

AU - Reimer, A.

AU - Reimer, O.

AU - Reposeur, T.

AU - Ritz, S.

AU - Rochester, L. S.

AU - Rodriguez, A. Y.

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 - Sellerholm, A.

AU - Sgrò, C.

AU - Shaw, M. S.

AU - Siskind, E. J.

AU - Smith, D. A.

AU - Smith, P. D.

AU - Spandre, G.

AU - Spinelli, P.

AU - Starck, J. L.

AU - Strickman, M. S.

AU - Strong, A. W.

AU - Suson, D. J.

AU - Tajima, H.

AU - Takahashi, H.

AU - Takahashi, T.

AU - Tanaka, T.

AU - Thayer, J. B.

AU - Thayer, J. G.

AU - Thompson, D. J.

AU - Tibaldo, L.

AU - Torres, D. F.

AU - Tosti, G.

AU - Tramacere, A.

AU - Uchiyama, Y.

AU - Usher, T. L.

AU - Vasileiou, V.

AU - Vilchez, N.

AU - Vitale, V.

AU - Waite, A. P.

AU - Wang, P.

AU - Winer, B. L.

AU - Wood, K. S.

AU - Ylinen, T.

AU - Ziegler, M.

PY - 2010/3/8

Y1 - 2010/3/8

N2 - We report on the first Fermi Large Area Telescope (LAT) measurements of the so-called "extragalactic" diffuse γ-ray emission (EGB). This component of the diffuse γ-ray emission is generally considered to have an isotropic or nearly isotropic distribution on the sky with diverse contributions discussed in the literature. The derivation of the EGB is based on detailed modeling of the bright foreground diffuse Galactic γ-ray emission, the detected LAT sources, and the solar γ-ray emission. We find the spectrum of the EGB is consistent with a power law with a differential spectral index γ=2.41±0.05 and intensity I(>100MeV)=(1. 03±0.17)×10-5cm-2s-1sr -1, where the error is systematics dominated. Our EGB spectrum is featureless, less intense, and softer than that derived from EGRET data.

AB - We report on the first Fermi Large Area Telescope (LAT) measurements of the so-called "extragalactic" diffuse γ-ray emission (EGB). This component of the diffuse γ-ray emission is generally considered to have an isotropic or nearly isotropic distribution on the sky with diverse contributions discussed in the literature. The derivation of the EGB is based on detailed modeling of the bright foreground diffuse Galactic γ-ray emission, the detected LAT sources, and the solar γ-ray emission. We find the spectrum of the EGB is consistent with a power law with a differential spectral index γ=2.41±0.05 and intensity I(>100MeV)=(1. 03±0.17)×10-5cm-2s-1sr -1, where the error is systematics dominated. Our EGB spectrum is featureless, less intense, and softer than that derived from EGRET data.

UR - http://www.scopus.com/inward/record.url?scp=77749298248&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77749298248&partnerID=8YFLogxK

U2 - 10.1103/PhysRevLett.104.101101

DO - 10.1103/PhysRevLett.104.101101

M3 - Article

AN - SCOPUS:77749298248

SN - 0031-9007

VL - 104

JO - Physical Review Letters

JF - Physical Review Letters

IS - 10

M1 - 101101

ER -

Spectrum of the isotropic diffuse gamma-ray emission derived from first-year fermi large area telescope data

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