Fermi-LAT study of Gamma-ray emission in the direction of supernova remnant W49B

A. A. Abdo, M. Ackermann, M. Ajello, L. Baldini, J. Ballet, G. Barbiellini, D. Bastieri, K. Bechtol, R. Bellazzini, E. D. Bloom, E. Bonamente, A. W. Borgland, A. Bouvier, J. Bregeon, A. Brez, M. Brigida, P. Bruel, R. Buehler, S. Buson, G. A. CaliandroR. A. Cameron, P. A. Caraveo, J. M. Casandjian, C. Cecchi, Ö Çelik, C. C. Cheung, J. Chiang, S. Ciprini, R. Claus, J. Cohen-Tanugi, J. Conrad, C. D. Dermer, F. De Palma, S. W. Digel, E. Do couto E Silva, P. S. Drell, D. Dumora, C. Favuzzi, S. Funk, P. Fusco, F. Gargano, N. Gehrels, N. Giglietto, F. Giordano, M. Giroletti, T. Glanzman, G. Godfrey, I. A. Grenier, M. H. Grondin, J. E. Grove, L. Guillemot, S. Guiriec, D. Hadasch, Y. Hanabata, A. K. Harding, M. Hayashida, E. Hays, D. Horan, R. E. Hughes, M. S. Jackson, G. Jóhannesson, A. S. Johnson, W. N. Johnson, T. Kamae, H. Katagiri, Jun Kataoka, J. Katsuta, J. Knödlseder, M. Kuss, J. Lande, L. Latronico, S. H. Lee, M. Lemoine-Goumard, F. Longo, F. Loparco, M. N. Lovellette, P. Lubrano, A. Makeev, M. N. Mazziotta, T. Mizuno, C. Monte, M. E. Monzani, A. Morselli, I. V. Moskalenko, S. Murgia, M. Naumann-Godo, P. L. Nolan, J. P. Norris, E. Nuss, T. Ohsugi, A. Okumura, N. Omodei, E. Orlando, J. F. Ormes, V. Pelassa, M. Pepe, M. Pesce-Rollins, F. Piron, S. Rainò, R. Rando, M. Razzano, A. Reimer, O. Reimer, T. Reposeur, J. Ripken, M. Roth, H. F W Sadrozinski, A. Sander, P. M. Saz Parkinson, C. Sgrò, E. J. Siskind, D. A. Smith, P. D. Smith, P. Spinelli, M. S. Strickman, D. J. Suson, H. Tajima, H. Takahashi, T. Takahashi, T. Tanaka, L. Tibaldo, O. Tibolla, D. F. Torres, G. Tosti, A. Tramacere, Y. Uchiyama, T. L. Usher, J. Vandenbroucke, V. Vasileiou, V. Vitale, A. P. Waite, P. Wang, B. L. Winer, K. S. Wood, T. Ylinen, M. Ziegler

    Research output: Contribution to journalArticle

    87 Citations (Scopus)

    Abstract

    We present an analysis of the gamma-ray data obtained with the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope in the direction of SNR W49B (G43.3-0.2). A bright unresolved gamma-ray source detected at a significance of 38s is found to coincide with SNR W49B. The energy spectrum in the 0.2-200 GeV range gradually steepens toward high energies. The luminosity is estimated to be 1.5 × 1036 (D/8 kpc)2 erg s -1 in this energy range. There is no indication that the gamma-ray emission comes from a pulsar. Assuming that the supernova remnant (SNR) shell is the site of gamma-ray production, the observed spectrum can be explained either by the decay of neutral π mesons produced through the proton-proton collisions or by electron bremsstrahlung. The calculated energy density of relativistic particles responsible for the LAT flux is estimated to be remarkably large, Ue,p > 104 eVcm-3, for either gamma-ray production mechanism.

    Original languageEnglish
    Pages (from-to)1303-1311
    Number of pages9
    JournalAstrophysical Journal
    Volume722
    Issue number2
    DOIs
    Publication statusPublished - 2010 Oct 20

    Fingerprint

    supernova remnants
    gamma rays
    telescopes
    energy
    Fermi Gamma-ray Space Telescope
    protons
    relativistic particles
    bremsstrahlung
    pulsars
    erg
    indication
    energy spectra
    mesons
    flux density
    collision
    luminosity
    shell
    electron
    collisions
    decay

    Keywords

    • Acceleration of particles
    • ISM: individual objects (W49B)
    • Radiation mechanisms: non-thermal

    ASJC Scopus subject areas

    • Space and Planetary Science
    • Astronomy and Astrophysics

    Cite this

    Abdo, A. A., Ackermann, M., Ajello, M., Baldini, L., Ballet, J., Barbiellini, G., ... Ziegler, M. (2010). Fermi-LAT study of Gamma-ray emission in the direction of supernova remnant W49B. Astrophysical Journal, 722(2), 1303-1311. https://doi.org/10.1088/0004-637X/722/2/1303

    Fermi-LAT study of Gamma-ray emission in the direction of supernova remnant W49B. / Abdo, A. A.; Ackermann, M.; Ajello, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bouvier, A.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Casandjian, J. M.; Cecchi, C.; Çelik, Ö; Cheung, C. C.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Conrad, J.; Dermer, C. D.; De Palma, F.; Digel, S. W.; Do couto E Silva, E.; Drell, P. S.; Dumora, D.; Favuzzi, C.; Funk, S.; Fusco, P.; Gargano, F.; Gehrels, N.; Giglietto, N.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Grondin, M. H.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Hadasch, D.; Hanabata, Y.; Harding, A. K.; Hayashida, M.; Hays, E.; Horan, D.; Hughes, R. E.; Jackson, M. S.; Jóhannesson, G.; Johnson, A. S.; Johnson, W. N.; Kamae, T.; Katagiri, H.; Kataoka, Jun; Katsuta, J.; Knödlseder, J.; Kuss, M.; Lande, J.; Latronico, L.; Lee, S. H.; Lemoine-Goumard, M.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Makeev, A.; Mazziotta, M. N.; Mizuno, T.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Naumann-Godo, M.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohsugi, T.; Okumura, A.; Omodei, N.; Orlando, E.; Ormes, J. F.; Pelassa, V.; Pepe, M.; Pesce-Rollins, M.; Piron, F.; Rainò, S.; Rando, R.; Razzano, M.; Reimer, A.; Reimer, O.; Reposeur, T.; Ripken, J.; Roth, M.; Sadrozinski, H. F W; Sander, A.; Saz Parkinson, P. M.; Sgrò, C.; Siskind, E. J.; Smith, D. A.; Smith, P. D.; Spinelli, P.; Strickman, M. S.; Suson, D. J.; Tajima, H.; Takahashi, H.; Takahashi, T.; Tanaka, T.; Tibaldo, L.; Tibolla, O.; Torres, D. F.; Tosti, G.; Tramacere, A.; Uchiyama, Y.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Vitale, V.; Waite, A. P.; Wang, P.; Winer, B. L.; Wood, K. S.; Ylinen, T.; Ziegler, M.

    In: Astrophysical Journal, Vol. 722, No. 2, 20.10.2010, p. 1303-1311.

    Research output: Contribution to journalArticle

    Abdo, AA, Ackermann, M, Ajello, M, Baldini, L, Ballet, J, Barbiellini, G, Bastieri, D, Bechtol, K, Bellazzini, R, Bloom, ED, Bonamente, E, Borgland, AW, Bouvier, A, Bregeon, J, Brez, A, Brigida, M, Bruel, P, Buehler, R, Buson, S, Caliandro, GA, Cameron, RA, Caraveo, PA, Casandjian, JM, Cecchi, C, Çelik, Ö, Cheung, CC, Chiang, J, Ciprini, S, Claus, R, Cohen-Tanugi, J, Conrad, J, Dermer, CD, De Palma, F, Digel, SW, Do couto E Silva, E, Drell, PS, Dumora, D, Favuzzi, C, Funk, S, Fusco, P, Gargano, F, Gehrels, N, Giglietto, N, Giordano, F, Giroletti, M, Glanzman, T, Godfrey, G, Grenier, IA, Grondin, MH, Grove, JE, Guillemot, L, Guiriec, S, Hadasch, D, Hanabata, Y, Harding, AK, Hayashida, M, Hays, E, Horan, D, Hughes, RE, Jackson, MS, Jóhannesson, G, Johnson, AS, Johnson, WN, Kamae, T, Katagiri, H, Kataoka, J, Katsuta, J, Knödlseder, J, Kuss, M, Lande, J, Latronico, L, Lee, SH, Lemoine-Goumard, M, Longo, F, Loparco, F, Lovellette, MN, Lubrano, P, Makeev, A, Mazziotta, MN, Mizuno, T, Monte, C, Monzani, ME, Morselli, A, Moskalenko, IV, Murgia, S, Naumann-Godo, M, Nolan, PL, Norris, JP, Nuss, E, Ohsugi, T, Okumura, A, Omodei, N, Orlando, E, Ormes, JF, Pelassa, V, Pepe, M, Pesce-Rollins, M, Piron, F, Rainò, S, Rando, R, Razzano, M, Reimer, A, Reimer, O, Reposeur, T, Ripken, J, Roth, M, Sadrozinski, HFW, Sander, A, Saz Parkinson, PM, Sgrò, C, Siskind, EJ, Smith, DA, Smith, PD, Spinelli, P, Strickman, MS, Suson, DJ, Tajima, H, Takahashi, H, Takahashi, T, Tanaka, T, Tibaldo, L, Tibolla, O, Torres, DF, Tosti, G, Tramacere, A, Uchiyama, Y, Usher, TL, Vandenbroucke, J, Vasileiou, V, Vitale, V, Waite, AP, Wang, P, Winer, BL, Wood, KS, Ylinen, T & Ziegler, M 2010, 'Fermi-LAT study of Gamma-ray emission in the direction of supernova remnant W49B', Astrophysical Journal, vol. 722, no. 2, pp. 1303-1311. https://doi.org/10.1088/0004-637X/722/2/1303
    Abdo AA, Ackermann M, Ajello M, Baldini L, Ballet J, Barbiellini G et al. Fermi-LAT study of Gamma-ray emission in the direction of supernova remnant W49B. Astrophysical Journal. 2010 Oct 20;722(2):1303-1311. https://doi.org/10.1088/0004-637X/722/2/1303
    Abdo, A. A. ; Ackermann, M. ; Ajello, M. ; Baldini, L. ; Ballet, J. ; Barbiellini, G. ; Bastieri, D. ; Bechtol, K. ; Bellazzini, R. ; Bloom, E. D. ; Bonamente, E. ; Borgland, A. W. ; Bouvier, A. ; Bregeon, J. ; Brez, A. ; Brigida, M. ; Bruel, P. ; Buehler, R. ; Buson, S. ; Caliandro, G. A. ; Cameron, R. A. ; Caraveo, P. A. ; Casandjian, J. M. ; Cecchi, C. ; Çelik, Ö ; Cheung, C. C. ; Chiang, J. ; Ciprini, S. ; Claus, R. ; Cohen-Tanugi, J. ; Conrad, J. ; Dermer, C. D. ; De Palma, F. ; Digel, S. W. ; Do couto E Silva, E. ; Drell, P. S. ; Dumora, D. ; Favuzzi, C. ; Funk, S. ; Fusco, P. ; Gargano, F. ; Gehrels, N. ; Giglietto, N. ; Giordano, F. ; Giroletti, M. ; Glanzman, T. ; Godfrey, G. ; Grenier, I. A. ; Grondin, M. H. ; Grove, J. E. ; Guillemot, L. ; Guiriec, S. ; Hadasch, D. ; Hanabata, Y. ; Harding, A. K. ; Hayashida, M. ; Hays, E. ; Horan, D. ; Hughes, R. E. ; Jackson, M. S. ; Jóhannesson, G. ; Johnson, A. S. ; Johnson, W. N. ; Kamae, T. ; Katagiri, H. ; Kataoka, Jun ; Katsuta, J. ; Knödlseder, J. ; Kuss, M. ; Lande, J. ; Latronico, L. ; Lee, S. H. ; Lemoine-Goumard, M. ; Longo, F. ; Loparco, F. ; Lovellette, M. N. ; Lubrano, P. ; Makeev, A. ; Mazziotta, M. N. ; Mizuno, T. ; Monte, C. ; Monzani, M. E. ; Morselli, A. ; Moskalenko, I. V. ; Murgia, S. ; Naumann-Godo, M. ; Nolan, P. L. ; Norris, J. P. ; Nuss, E. ; Ohsugi, T. ; Okumura, A. ; Omodei, N. ; Orlando, E. ; Ormes, J. F. ; Pelassa, V. ; Pepe, M. ; Pesce-Rollins, M. ; Piron, F. ; Rainò, S. ; Rando, R. ; Razzano, M. ; Reimer, A. ; Reimer, O. ; Reposeur, T. ; Ripken, J. ; Roth, M. ; Sadrozinski, H. F W ; Sander, A. ; Saz Parkinson, P. M. ; Sgrò, C. ; Siskind, E. J. ; Smith, D. A. ; Smith, P. D. ; Spinelli, P. ; Strickman, M. S. ; Suson, D. J. ; Tajima, H. ; Takahashi, H. ; Takahashi, T. ; Tanaka, T. ; Tibaldo, L. ; Tibolla, O. ; Torres, D. F. ; Tosti, G. ; Tramacere, A. ; Uchiyama, Y. ; Usher, T. L. ; Vandenbroucke, J. ; Vasileiou, V. ; Vitale, V. ; Waite, A. P. ; Wang, P. ; Winer, B. L. ; Wood, K. S. ; Ylinen, T. ; Ziegler, M. / Fermi-LAT study of Gamma-ray emission in the direction of supernova remnant W49B. In: Astrophysical Journal. 2010 ; Vol. 722, No. 2. pp. 1303-1311.
    @article{eb9a1807340446bc9d9b96752db21379,
    title = "Fermi-LAT study of Gamma-ray emission in the direction of supernova remnant W49B",
    abstract = "We present an analysis of the gamma-ray data obtained with the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope in the direction of SNR W49B (G43.3-0.2). A bright unresolved gamma-ray source detected at a significance of 38s is found to coincide with SNR W49B. The energy spectrum in the 0.2-200 GeV range gradually steepens toward high energies. The luminosity is estimated to be 1.5 × 1036 (D/8 kpc)2 erg s -1 in this energy range. There is no indication that the gamma-ray emission comes from a pulsar. Assuming that the supernova remnant (SNR) shell is the site of gamma-ray production, the observed spectrum can be explained either by the decay of neutral π mesons produced through the proton-proton collisions or by electron bremsstrahlung. The calculated energy density of relativistic particles responsible for the LAT flux is estimated to be remarkably large, Ue,p > 104 eVcm-3, for either gamma-ray production mechanism.",
    keywords = "Acceleration of particles, ISM: individual objects (W49B), Radiation mechanisms: non-thermal",
    author = "Abdo, {A. A.} and M. Ackermann and M. Ajello and L. Baldini and J. Ballet and G. Barbiellini and D. Bastieri and K. Bechtol and R. Bellazzini and Bloom, {E. D.} and E. Bonamente and Borgland, {A. W.} and A. Bouvier and J. Bregeon and A. Brez and M. Brigida and P. Bruel and R. Buehler and S. Buson and Caliandro, {G. A.} and Cameron, {R. A.} and Caraveo, {P. A.} and Casandjian, {J. M.} and C. Cecchi and {\"O} {\cC}elik and Cheung, {C. C.} and J. Chiang and S. Ciprini and R. Claus and J. Cohen-Tanugi and J. Conrad and Dermer, {C. D.} and {De Palma}, F. and Digel, {S. W.} and {Do couto E Silva}, E. and Drell, {P. S.} and D. Dumora and C. Favuzzi and S. Funk and P. Fusco and F. Gargano and N. Gehrels and N. Giglietto and F. Giordano and M. Giroletti 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 D. Hadasch and Y. Hanabata and Harding, {A. K.} and M. Hayashida and E. Hays and D. Horan and Hughes, {R. E.} and Jackson, {M. S.} and G. J{\'o}hannesson and Johnson, {A. S.} and Johnson, {W. N.} and T. Kamae and H. Katagiri and Jun Kataoka and J. Katsuta and J. Kn{\"o}dlseder and M. Kuss and J. Lande and L. Latronico and Lee, {S. H.} and M. Lemoine-Goumard and F. Longo and F. Loparco and Lovellette, {M. N.} and P. Lubrano and A. Makeev and Mazziotta, {M. N.} and T. Mizuno and C. Monte and Monzani, {M. E.} and A. Morselli and Moskalenko, {I. V.} and S. Murgia and M. Naumann-Godo and Nolan, {P. L.} and Norris, {J. P.} and E. Nuss and T. Ohsugi and A. Okumura and N. Omodei and E. Orlando and Ormes, {J. F.} and V. Pelassa and M. Pepe and M. Pesce-Rollins and F. Piron and S. Rain{\`o} and R. Rando and M. Razzano and A. Reimer and O. Reimer and T. Reposeur and J. Ripken and M. Roth and Sadrozinski, {H. F W} and A. Sander and {Saz Parkinson}, {P. M.} and C. Sgr{\`o} and Siskind, {E. J.} and Smith, {D. A.} and Smith, {P. D.} and P. Spinelli and Strickman, {M. S.} and Suson, {D. J.} and H. Tajima and H. Takahashi and T. Takahashi and T. Tanaka and L. Tibaldo and O. Tibolla and Torres, {D. F.} and G. Tosti and A. Tramacere and Y. Uchiyama and Usher, {T. L.} and J. Vandenbroucke and V. Vasileiou 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 = "10",
    day = "20",
    doi = "10.1088/0004-637X/722/2/1303",
    language = "English",
    volume = "722",
    pages = "1303--1311",
    journal = "Astrophysical Journal",
    issn = "0004-637X",
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    }

    TY - JOUR

    T1 - Fermi-LAT study of Gamma-ray emission in the direction of supernova remnant W49B

    AU - Abdo, A. A.

    AU - Ackermann, M.

    AU - Ajello, M.

    AU - Baldini, L.

    AU - Ballet, J.

    AU - Barbiellini, G.

    AU - Bastieri, D.

    AU - Bechtol, K.

    AU - Bellazzini, R.

    AU - Bloom, E. D.

    AU - Bonamente, E.

    AU - Borgland, A. W.

    AU - Bouvier, A.

    AU - Bregeon, J.

    AU - Brez, A.

    AU - Brigida, M.

    AU - Bruel, P.

    AU - Buehler, R.

    AU - Buson, S.

    AU - Caliandro, G. A.

    AU - Cameron, R. A.

    AU - Caraveo, P. A.

    AU - Casandjian, J. M.

    AU - Cecchi, C.

    AU - Çelik, Ö

    AU - Cheung, C. C.

    AU - Chiang, J.

    AU - Ciprini, S.

    AU - Claus, R.

    AU - Cohen-Tanugi, J.

    AU - Conrad, J.

    AU - Dermer, C. D.

    AU - De Palma, F.

    AU - Digel, S. W.

    AU - Do couto E Silva, E.

    AU - Drell, P. S.

    AU - Dumora, D.

    AU - Favuzzi, C.

    AU - Funk, S.

    AU - Fusco, P.

    AU - Gargano, F.

    AU - Gehrels, N.

    AU - Giglietto, N.

    AU - Giordano, F.

    AU - Giroletti, M.

    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 - Hadasch, D.

    AU - Hanabata, Y.

    AU - Harding, A. K.

    AU - Hayashida, M.

    AU - Hays, E.

    AU - Horan, D.

    AU - Hughes, R. E.

    AU - Jackson, M. S.

    AU - Jóhannesson, G.

    AU - Johnson, A. S.

    AU - Johnson, W. N.

    AU - Kamae, T.

    AU - Katagiri, H.

    AU - Kataoka, Jun

    AU - Katsuta, J.

    AU - Knödlseder, J.

    AU - Kuss, M.

    AU - Lande, J.

    AU - Latronico, L.

    AU - Lee, S. H.

    AU - Lemoine-Goumard, M.

    AU - Longo, F.

    AU - Loparco, F.

    AU - Lovellette, M. N.

    AU - Lubrano, P.

    AU - Makeev, A.

    AU - Mazziotta, M. N.

    AU - Mizuno, T.

    AU - Monte, C.

    AU - Monzani, M. E.

    AU - Morselli, A.

    AU - Moskalenko, I. V.

    AU - Murgia, S.

    AU - Naumann-Godo, M.

    AU - Nolan, P. L.

    AU - Norris, J. P.

    AU - Nuss, E.

    AU - Ohsugi, T.

    AU - Okumura, A.

    AU - Omodei, N.

    AU - Orlando, E.

    AU - Ormes, J. F.

    AU - Pelassa, V.

    AU - Pepe, M.

    AU - Pesce-Rollins, M.

    AU - Piron, F.

    AU - Rainò, S.

    AU - Rando, R.

    AU - Razzano, M.

    AU - Reimer, A.

    AU - Reimer, O.

    AU - Reposeur, T.

    AU - Ripken, J.

    AU - Roth, M.

    AU - Sadrozinski, H. F W

    AU - Sander, A.

    AU - Saz Parkinson, P. M.

    AU - Sgrò, C.

    AU - Siskind, E. J.

    AU - Smith, D. A.

    AU - Smith, P. D.

    AU - Spinelli, P.

    AU - Strickman, M. S.

    AU - Suson, D. J.

    AU - Tajima, H.

    AU - Takahashi, H.

    AU - Takahashi, T.

    AU - Tanaka, T.

    AU - Tibaldo, L.

    AU - Tibolla, O.

    AU - Torres, D. F.

    AU - Tosti, G.

    AU - Tramacere, A.

    AU - Uchiyama, Y.

    AU - Usher, T. L.

    AU - Vandenbroucke, J.

    AU - Vasileiou, V.

    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 - 2010/10/20

    Y1 - 2010/10/20

    N2 - We present an analysis of the gamma-ray data obtained with the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope in the direction of SNR W49B (G43.3-0.2). A bright unresolved gamma-ray source detected at a significance of 38s is found to coincide with SNR W49B. The energy spectrum in the 0.2-200 GeV range gradually steepens toward high energies. The luminosity is estimated to be 1.5 × 1036 (D/8 kpc)2 erg s -1 in this energy range. There is no indication that the gamma-ray emission comes from a pulsar. Assuming that the supernova remnant (SNR) shell is the site of gamma-ray production, the observed spectrum can be explained either by the decay of neutral π mesons produced through the proton-proton collisions or by electron bremsstrahlung. The calculated energy density of relativistic particles responsible for the LAT flux is estimated to be remarkably large, Ue,p > 104 eVcm-3, for either gamma-ray production mechanism.

    AB - We present an analysis of the gamma-ray data obtained with the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope in the direction of SNR W49B (G43.3-0.2). A bright unresolved gamma-ray source detected at a significance of 38s is found to coincide with SNR W49B. The energy spectrum in the 0.2-200 GeV range gradually steepens toward high energies. The luminosity is estimated to be 1.5 × 1036 (D/8 kpc)2 erg s -1 in this energy range. There is no indication that the gamma-ray emission comes from a pulsar. Assuming that the supernova remnant (SNR) shell is the site of gamma-ray production, the observed spectrum can be explained either by the decay of neutral π mesons produced through the proton-proton collisions or by electron bremsstrahlung. The calculated energy density of relativistic particles responsible for the LAT flux is estimated to be remarkably large, Ue,p > 104 eVcm-3, for either gamma-ray production mechanism.

    KW - Acceleration of particles

    KW - ISM: individual objects (W49B)

    KW - Radiation mechanisms: non-thermal

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    UR - http://www.scopus.com/inward/citedby.url?scp=78149236068&partnerID=8YFLogxK

    U2 - 10.1088/0004-637X/722/2/1303

    DO - 10.1088/0004-637X/722/2/1303

    M3 - Article

    AN - SCOPUS:78149236068

    VL - 722

    SP - 1303

    EP - 1311

    JO - Astrophysical Journal

    JF - Astrophysical Journal

    SN - 0004-637X

    IS - 2

    ER -