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51. Early Fermi Gamma-ray Space Telescope Observations of the Quasar 3C 454.3

Author

A. A. Abdo, M. Ackermann, M. Ajello, W. B. Atwood, M. Axelsson, L. Baldini, J. Ballet, G. Barbiellini, D. Bastieri, M. Battelino, B. M. Baughman, K. Bechtol, R. Bellazzini, B. Berenji, R. D. Blandford, E. D. Bloom, E. Bonamente, A. W. Borgland, A. Bouvier, J. Bregeon, A. Brez, M. Brigida, P. Bruel, T. H. Burnett, G. A. Caliandro, R. A. Cameron, P. A. Caraveo, J. M. Casandjian, E. Cavazzuti, C. Cecchi, E. Charles, S. Chaty, A. Chekhtman, C. C. Cheung, J. Chiang, S. Ciprini, R. Claus, J. Cohen-Tanugi, L. R. Cominsky, J. Conrad, L. Costamante, S. Cutini, C. D. Dermer, A. de Angelis, F. de Palma, S. W. Digel, E. do Couto e Silva, D. Donato, P. S. Drell, R. Dubois, D. Dumora, C. Farnier, C. Favuzzi, W. B. Focke, L. Foschini, M. Frailis, L. Fuhrmann, Y. Fukazawa, S. Funk, P. Fusco, 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, Y. Hanabata, A. K. Harding, R. C. Hartman, M. Hayashida, E. Hays, R. E. Hughes, G. Jóhannesson, A. S. Johnson, R. P. Johnson, W. N. Johnson, T. Kamae, H. Katagiri, J. Kataoka, N. Kawai, M. Kerr, J. Knödlseder, M. L. Kocian, F. Kuehn, M. Kuss, L. Latronico, S.-H. Lee, M. Lemoine-Goumard, F. Longo, F. Loparco, B. Lott, M. N. Lovellette, P. Lubrano, G. M. Madejski, A. Makeev, E. Massaro, M. N. Mazziotta, J. E. McEnery, S. McGlynn, 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, L. C. Reyes, S. Ritz, L. S. Rochester, A. Y. Rodriguez, F. Rahoui, F. Ryde, H. F.-W. Sadrozinski, R. Sambruna, D. Sanchez, A. Sander, P. M. Saz Parkinson, C. Sgrò, M. S. Shaw, D. A. Smith, P. D. Smith, G. Spandre, P. Spinelli, J.-L. Starck, M. S. Strickman, 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, N. Vilchez, M. Villata, V. Vitale, A. P. Waite, B. L. Winer, K. S. Wood, T. Ylinen, J. A. Zensus, M. Ziegler, Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Théorique et Astroparticules (LPTA), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre d'étude spatiale des rayonnements (CESR), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Fermi-LAT, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Abdo, A. A., Ackermann, M., Ajello, M., Atwood, W. B., Axelsson, M., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Battelino, M., Baughman, B. M., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Bouvier, A., Bregeon, J., Brez, A., Brigida, M., Bruel, P., Burnett, T. H., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Charles, E., Chaty, S., Chekhtman, A., Cheung, C. C., Chiang, J., Ciprini, S., Claus, R., Cohen Tanugi, J., Cominsky, L. R., Conrad, J., Costamante, L., Cutini, S., Dermer, C. D., Angelis, A. d., Palma, F. d., Digel, S. W., Silva, E. D. E., Donato, D., Drell, P. S., Dubois, R., Dumora, D., Farnier, C., Favuzzi, C., Focke, W. B., Foschini, L., Frailis, M., Fuhrmann, L., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giebels, B., Giglietto, N., Giommi, P., Giordano, F., Glanzman, T., Godfrey, G., Grenier, I. A., Grondin, M. H., Grove, J. E., Guillemot, L., Guiriec, S., Hanabata, Y., Harding, A. K., Hartman, R. C., Hayashida, M., Hays, E., Hughes, R. E., Johannesson, G., Johnson, A. S., Johnson, R. P., Johnson, W. N., Kamae, T., Katagiri, H., Kataoka, J., Kawai, N., Kerr, M., Knodlseder, J., Kocian, M. L., Kuehn, F., Kuss, M., Latronico, L., Lee, S. H., Lemoine Goumard, M., Longo, Francesco, Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Makeev, A., Massaro, E., Mazziotta, M. N., Mcenery, J. E., Mcglynn, S., Meurer, C., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nolan, P. L., Norris, J. P., Nuss, E., Ohsugi, T., Omodei, N., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Parent, D., Pelassa, V., Pepe, M., Pesce Rollins, M., Piron, F., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Reposeur, T., Reyes, L. C., Ritz, S., Rochester, L. S., Rodriguez, A. Y., Rahoui, F., Ryde, F., Sadrozinski, H. F. W., Sambruna, R., Sanchez, D., Sander, A., Parkinson, P. M. S., Sgro, C., Shaw, M. S., Smith, D. A., Smith, P. D., Spandre, G., Spinelli, P., Starck, J. L., Strickman, M. S., Suson, D. J., Tajima, H., Takahashi, H., Takahashi, T., Tanaka, T., Thayer, J. B., Thayer, J. G., Thompson, D. J., Tibaldo, L., Torres, D. F., Tosti, G., Tramacere, A., Uchiyama, Y., Usher, T. L., Vilchez, N., Villata, M., Vitale, V., Waite, A. P., Winer, B. L., Wood, K. S., Ylinen, T., Zensus, J. A., and Ziegler, M.

Subjects
[PHYS.ASTR.HE]Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], High Energy Gamma-ray Astronomy, Fermi satellite, Active Galactic Nuclei, Astrophysics::High Energy Astrophysical Phenomena, galaxies: active, Astrophysics, 01 natural sciences, Luminosity, law.invention, Telescope, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Relativistic beaming, quasars: individual: 3C 454.3, Spitzer Space Telescope, law, 0103 physical sciences, Blazar, 010303 astronomy & astrophysics, Physics, 010308 nuclear & particles physics, [SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Galaxies: active, Gamma rays: observations, Quasars: individual, Astronomy and Astrophysics, Quasar, Pair production, Space and Planetary Science, gamma rays: observations, quasars: individual, quasars: individual (3c 454.3), Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Nongalactic Astrophysics, Fermi Gamma-ray Space Telescope
Abstract

著者人数：181名, Accepted: 2009-04-27, 資料番号: SA1000973000

Published
2009

52. The estimation of background production by cosmic rays in high-energy gamma ray telescopes

Author

P. L. Nolan, D. L. Bertsch, R. C. Hartman, E. B. Hughes, C. E. Fichtel, B. W. Hughlock, D. J. Thompson, Stanley D. Hunter, D.G. Koch, E. J. Schneid, H.L. Edwards, G. Kanhack, D. A. Kniffen, Yiing Lin, and M. Sommer

Subjects
Physics, Nuclear and High Energy Physics, biology, Astrophysics::High Energy Astrophysical Phenomena, Monte Carlo method, Astrophysics::Instrumentation and Methods for Astrophysics, Gamma ray, Astronomy, Cosmic ray, Astrophysics, Gamma-ray astronomy, biology.organism_classification, Particle detector, law.invention, Telescope, Nuclear Energy and Engineering, law, Egret, Electrical and Electronic Engineering, Astrophysics::Galaxy Astrophysics, Background radiation
Abstract

A calculation method of estimating instrumental background in high-energy gamma -ray telescopes, using the hadronic Monte Carlo code FLUKA87, is presented. The method is applied to the SAS-2 and EGRET telescope designs and is also used to explore the level of background to be expected for alternative configurations of the proposed GRITS telescope, which adapts the external fuel tank of a Space Shuttle as a gamma -ray telescope with a very large collecting area. The background produced in proton-beam tests of EGRET is much less than the predicted level. This discrepancy appears to be due to the FLUKA87 inability to transport evaporation nucleons. It is predicted that the background in EGRET will be no more than 4-10 % of the extragalactic diffuse gamma radiation. >

Published
1991

53. The Fermi Gamma-Ray Space Telescope Discovers the Pulsar in the Young Galactic Supernova Remnant CTA 1

Author

M. N. Mazziotta, M. L. Kocian, T. H. Burnett, M. Ziegler, R. Rando, Jean Ballet, Sinéad McGlynn, Stefano Ciprini, C. Farnier, Diego F. Torres, C. C. Cheung, T. Reposeur, P. Fusco, Luca Baldini, Paul J. Wang, David Sánchez, Hideaki Katagiri, Elliott D. Bloom, Sylvain Guiriec, Brian L Winer, Andrea Tramacere, Y. Kanai, Stefan Funk, T. Kishishita, A. A. Moiseev, F. Longo, Roger W. Romani, Carmelo Sgrò, Jan Conrad, Steven Ritz, Pascal Bruel, E. Nuss, Gino Tosti, R. E. Hughes, David Paneque, M. Kuss, D. Parent, F. Loparco, H. Tajima, E. Do Couto E Silva, R. C. Hartman, Peter F. Michelson, F. Kuehn, Keith Bechtol, M. Ozaki, D. J. Thompson, P. D. Smith, Richard Dubois, T. A. Porter, J.H. Panetta, Melissa Pesce-Rollins, F. de Palma, J. G. Thayer, Hartmut Sadrozinski, David Smith, A. Sellerholm, T. Schalk, P. Lubrano, A. Sander, Teresa Mineo, Nicola Omodei, M. Razzano, L.S. Rochester, T. L. Usher, S. Rainò, P. Carlson, Tsunefumi Mizuno, M.-H. Grondin, Hajimu Yasuda, Hiromitsu Takahashi, E. Hays, G.L. Godfrey, Markus Roth, G. Bogaert, Tadayuki Takahashi, Paul S. Ray, B. M. Baughman, Stephen E. Thorsett, F. Gargano, L. Pieri, Emanuele Bonamente, J. E. Grove, Yasushi Fukazawa, A. A. Abdo, E. Orlando, E. Charles, Karen Watters, M. Dormody, E. J. Siskind, G. Piano, D. Dumora, Takaaki Tanaka, W. N. Johnson, A. De Angelis, Randall P. Johnson, Matthew Kerr, T. Ylinen, J. B. Thayer, P. L. Nolan, N. Gehrels, A. Reimer, W. B. Focke, N. Komin, B. Berenji, A. Chekhtman, N. Vilchez, Markus Ackermann, Luca Latronico, S. Germani, Claudia Cecchi, P. Spinelli, Y. Edmonds, Francesco Giordano, Ronaldo Bellazzini, D. J. Suson, L. R. Cominsky, A. Van Etten, Igor V. Moskalenko, J. F. Ormes, Jean-Luc Starck, Olaf Reimer, R. A. Cameron, A. Morselli, V. Pelassa, V. Vitale, Charles D. Dermer, J. Bregeon, Julie McEnery, A. W. Borgland, C. Meurer, C. Monte, A. S. Johnson, S. Cutini, M. Pepe, James Chiang, Roger Blandford, M. Marelli, Bulent Kiziltan, Matthew G. Baring, N. Kawai, A. Makeev, M. E. Monzani, Takeshi Nakamori, J. M. Casandjian, T. Ohsugi, S. W. Digel, T. J. Johnson, T. Glanzman, Denis Bastieri, Gudlaugur Johannesson, Felix Ryde, G. A. Caliandro, Guido Barbiellini, P. M. Saz Parkinson, V. Lonjou, A. Brez, Jürgen Knödlseder, R. Claus, W. Mitthumsiri, Gottfried Kanbach, Dario Gasparrini, B. Giebels, B. Lott, F. Piron, T. Kamae, N. Giglietto, S. Murgia, Masanori Ohno, L. Tibaldo, Alice K. Harding, W. B. Atwood, D. Davis, M. N. Lovellette, P. A. Caraveo, Persis S. Drell, Kent S. Wood, M. Brigida, A. Y. Rodriguez, L. Guillemot, I. A. Grenier, Atsushi Okumura, Gloria Spandre, Johann Cohen-Tanugi, M. S. Strickman, M. Lemoine-Goumard, Abdo, A. A., Ackermann, M., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Baring, M. G., Bastieri, D., Baughman, B. M., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bloom, E. D., Bogaert, G., Bonamente, E., Borgland, A. W., Bregeon, J., Brez, A., Brigida, M., Bruel, P., Burnett, T. H., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Carlson, P., Casandjian, J. M., Cecchi, C., Charles, E., Chekhtman, A., Cheung, C. C., Chiang, J., Ciprini, S., Claus, R., Cohen Tanugi, J., Cominsky, L. R., Conrad, J., Cutini, S., Davis, D. S., Dermer, C. D., Angelis, A. d., Palma, F. d., Digel, S. W., Dormody, M., Silva, E. D. E., Drell, P. S., Dubois, R., Dumora, D., Edmonds, Y., Farnier, C., Focke, W. B., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giebels, B., Giglietto, N., Giordano, F., Glanzman, T., Godfrey, G., Grenier, I. A., Grondin, M. H., Grove, J. E., Guillemot, L., Guiriec, S., Harding, A. K., Hartman, R. C., Hays, E., Hughes, R. E., Johannesson, G., Johnson, A. S., Johnson, R. P., Johnson, T. J., Johnson, W. N., Kamae, T., Kanai, Y., Kanbach, G., Katagiri, H., Kawai, N., Kerr, M., Kishishita, T., Kiziltan, B., Knodlseder, J., Kocian, M. L., Komin, N., Kuehn, F., Kuss, M., Latronico, L., Lemoine Goumard, M., Longo, Francesco, Lonjou, V., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Makeev, A., Marelli, M., Mazziotta, M. N., Mcenery, J. E., Mcglynn, S., Meurer, C., Michelson, P. F., Mineo, T., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Nolan, P. L., Nuss, E., Ohno, M., Ohsugi, T., Okumura, A., Omodei, N., Orlando, E., Ormes, J. F., Ozaki, M., Paneque, D., Panetta, J. H., Parent, D., Pelassa, V., Pepe, M., Pesce Rollins, M., Piano, G., Pieri, L., Piron, F., Porter, T. A., Raino, S., Rando, R., Ray, P. S., Razzano, M., Reimer, A., Reimer, O., Reposeur, T., Ritz, S., Rochester, L. S., Rodriguez, A. Y., Romani, R. W., Roth, M., Ryde, F., Sadrozinski, H. F. W., Sanchez, D., Sander, A., Parkinson, P. M. S., Schalk, T. L., Sellerholm, A., Sgro, C., Siskind, E. J., Smith, D. A., Smith, P. D., Spandre, G., Spinelli, P., Starck, J. L., Strickman, M. S., Suson, D. J., Tajima, H., Takahashi, H., Takahashi, T., Tanaka, T., Thayer, J. B., Thayer, J. G., Thompson, D. J., Thorsett, S. E., Tibaldo, L., Torres, D. F., Tosti, G., Tramacere, A., Usher, T. L., Etten, A. V., Vilchez, N., Vitale, V., Wang, P., Watters, K., Winer, B. L., Wood, K. S., Yasuda, H., Ylinen, T., Ziegler, M., Département d'Astrophysique (ex SAP) (DAP), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Théorique et Astroparticules (LPTA), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre d'étude spatiale des rayonnements (CESR), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Roma Tor Vergata [Roma], Centre d'études scientifiques et techniques d'Aquitaine (CESTA), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), and Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Fermi satellite, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, High Energy Gamma-ray Astronomy, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Spitzer Space Telescope, Pulsar, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Supernova remnant, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Physics, Nebula, Multidisciplinary, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Astrophysics (astro-ph), Astrophysics::Instrumentation and Methods for Astrophysics, Gamma ray, Astronomy, Stars, Supernova, Fermi Gamma-ray Space Telescope
Abstract

Energetic young pulsars and expanding blast waves (supernova remnants, SNRs) are the most visible remains after massive stars, ending their lives, explode in core-collapse supernovae. The Fermi Gamma-Ray Space Telescope has unveiled a radio quiet pulsar located near the center of the compact synchrotron nebula inside the supernova remnant CTA 1. The pulsar, discovered through its gamma-ray pulsations, has a period of 316.86 ms, a period derivative of 3.614 x 10-13 s s-1 . Its characteristic age of 104 years is comparable to that estimated for the SNR. It is conjectured that most unidentified Galactic gamma ray sources associated with star-forming regions and SNRs are such young pulsars., 18 pages, 3 figures + supplemental material, published in Science Express, October 16, 2008, Contact authors: G. Kanbach, K. Wood, M. Ziegler

Published
2008

54. EGRET Gamma‐Ray Observations of the Crab P2/P1 Ratio

Author

W. F. Tompkins, P. L. Nolan, D. J. Thompson, B. B. Jones, P. V. Ramanamurthy, and Gottfried Kanbach

Subjects
Physics, biology, Crab Pulsar, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), Astrophysics::Instrumentation and Methods for Astrophysics, Gamma ray, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, biology.organism_classification, Light curve, Flux ratio, law.invention, Telescope, Space and Planetary Science, Observatory, law, Egret, Variation (astronomy)
Abstract

Recent observations of the Crab pulsar by the Energetic Gamma-Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory show that the high-energy gamma-ray light curve has changed little over the lifetime of the instrument. Previous data collected by SAS-2 and COS-B in the years 1972-82, along with earlier EGRET data, suggested a 14 year sinusoidal variation in the flux ratio between the first and second peaks. The new data from EGRET indicate that the flux ratio is constant., 6 pages, 3 figures. To be published in ApJ

Published
1997

55. Plastic Scintillator Block As Photon Beam Monitor For Egret Calibration

Author

R. Hofstadter, J. R. Mattox, E. B. Hughes, Yiing Lin, A. H. Walker, and P. L. Nolan

Subjects
Physics, Nuclear and High Energy Physics, Beam diameter, business.industry, Bremsstrahlung, Scintillator, Particle detector, Linear particle accelerator, Optics, Nuclear Energy and Engineering, Scintillation counter, Physics::Accelerator Physics, Energetic Gamma Ray Experiment Telescope, Electrical and Electronic Engineering, business, Beam (structure)
Abstract

The EGRET (Energetic Gamma Ray Experiment Telescope) detector has been calibrated at SLAC (Stanford Linear Accelerator) and, to a lesser degree, at the MIT (Massachusetts Institute of Technology) Bates Linear Accelerator Center. To monitor the photon beams for the calibration, a plastic scintillator block, 5 cm*5 cm in cross section, 15 cm in length, and viewed by a single photomultiplier tube, was used for the entire beam energy range of 15 MeV to 10 GeV. The design operation, and method of analysis of the beam intensity are presented. A mathematical framework has been developed to treat the general case of a beam with multiphoton beam pulses and with a background component. A procedure to deal with the fluctuations of the beam intensity over a data-taking period was also developed. The photon beam monitor is physically sturdy, electronically steady, simple to construct, and easy to operate. Its major merits lie in its sheer simplicity of construction and operation and in the wide energy range it can cover. >

Published
2005

56. Recalibration Of The Egret Gamma Ray Telescope At The Mit Bates Linear Accelerator Center

Author

D. A. Kniffen, B. W. Hughlock, R. C. Hartman, C.E. Fichtell, D. J. Thompson, Stanley D. Hunter, E.C. Booth, E. J. Schneid, A.-H. Walkers, Yiing Lin, E.B. Hughess, D.R. Tieger, K. Dow, P. L. Nolan, D. L. Bertsch, W.W. Sapp, and Gottfried Kanbach

Subjects
Nuclear physics, Physics, biology, Monte Carlo method, Calibration, Egret, BATES, Center (algebra and category theory), Astrophysics, biology.organism_classification, Linear particle accelerator, Fermi Gamma-ray Space Telescope
Published
2005

57. A Northern Survey of Gamma-Ray Blazar Candidates

Author

P. L. Nolan, Roger W. Romani, David Sowards-Emmerd, S. E. Healey, and Peter F. Michelson

Subjects
Physics, biology, media_common.quotation_subject, Astrophysics (astro-ph), Gamma ray, FOS: Physical sciences, Astronomy and Astrophysics, Quasar, Astrophysics, biology.organism_classification, Redshift, Space and Planetary Science, Sky, Observatory, Egret, Blazar, media_common
Abstract

In preparation for GLAST, we have compiled a sample of blazar candidates to increase the pool of well studied AGN from which GLAST counterparts will be drawn. Sources were selected with our Figure of Merit (FoM) ranking; thus, they have radio and X-ray properties very similar to the EGRET blazars. Spectroscopic confirmation of these candidates is in progress, and more than 70% of these objects have been identified as flat spectrum radio quasars and BL Lac objects. We present ~250 new optical blazar identifications based on McDonald Observatory spectroscopy, 224 with redshifts. Of these, 167 are in our FoM-selected set. To motivate the Gamma-ray nature of these objects, we analyzed the current release of the EGRET data for possible point sources at their radio positions. We develop two distinct methods to combine multiple EGRET observations of a sky position into a single detection significance. We report a detection of the signal of the set of blazar candidates in the EGRET data at the > 3 sigma level by both techniques. We predict that the majority of these blazar candidates will be found by GLAST due to its increased sensitivity, duty cycle and resolving power., ApJ Accepted (to appear 10 June 2005)

Published
2005
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59. Variability of EGRET Gamma-Ray Sources

Author

W. F. Tompkins, P. L. Nolan, Isabelle Grenier, and Peter F. Michelson

Subjects
Physics, education.field_of_study, Spiral galaxy, biology, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), Population, FOS: Physical sciences, Flux, Astronomy and Astrophysics, Astrophysics, Galactic plane, Table (information), biology.organism_classification, Pulsar, Space and Planetary Science, Egret, Blazar, education, Astrophysics::Galaxy Astrophysics
Abstract

The variability of the high-energy gamma ray sources in the Third EGRET catalog is analyzed by a new method. We re-analyze the EGRET data to calculate a likelihood function for the flux of each source in each observation, both for detections and upper limits. These functions can be combined in a uniform manner with a simple model of the flux distribution to characterize the flux variation by a confidence interval for the relative standard deviation of the flux. The main result is a table of these values for almost all the cataloged sources. As expected, the identified pulsars are steady emitters and the blazars are mostly highly variable. The unidentified sources are heterogeneous, with greater variation at higher Galactic latitude. There is an indication that pulsar wind nebulae are associated with variable sources. There is a population of variable sources along the Galactic plane, concentrated in the inner spiral arms., Accepted by ApJ. 13 pages, 3 figures, 2 tables. Machine-readable copies of Table 1 are at http://giants.stanford.edu/~pln/vartbl1/

Published
2003

60. Performance of the EGRET astronomical gamma ray telescope

Author

M. Sommer, H. A. Mayer-Hasselwander, R. C. Hartman, D. J. Thompson, Y.C. Lin, D. L. Bertsch, E. B. Hughes, R. Hofstadter, E. J. Schneid, D. A. Kniffen, Gottfried Kanbach, J.R. Mattox, Stanley D. Hunter, H. Rothermel, P. Sreekumar, K. Pinkau, C. E. Fichtel, Peter F. Michelson, P. L. Nolan, and C. von Montigny

Subjects
Physics, Nuclear and High Energy Physics, biology, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Gamma ray, Astronomy, Astrophysics, Gamma-ray astronomy, biology.organism_classification, law.invention, Telescope, Nuclear Energy and Engineering, Observatory, law, Egret, Energetic Gamma Ray Experiment Telescope, Angular resolution, Electrical and Electronic Engineering, Fermi Gamma-ray Space Telescope
Abstract

On April 5, 1991, the Space Shuttle Atlantis carried the Compton Gamma Ray Observatory into orbit and the satellite was deployed on April 7. The Energetic Gamma Ray Experiment Telescope (EGRET) instrument was activated on April 15, and the first month of operations was devoted to verification of the instrument performance. Measurements made during that month and in the subsequent sky survey phase have verified that the instrument time resolution, angular resolution, and gamma ray detection efficiency are all within nominal limits. >

Published
2002

61. Constraints on the cosmic rays in the Small Magellanic Cloud

Author

D. A. Kniffen, C. E. Fichtel, J. R. Mattox, R. C. Hartman, E. J. Schneid, Gottfried Kanbach, D. J. Thompson, Peter F. Michelson, Y. C. Lin, K. Pinkau, P. L. Nolan, H. A. Mayer-Hasselwander, C. von Montigny, Stanley D. Hunter, D. L. Bertsch, P. Sreekumar, R. G. Stone, and Brenda Dingus

Subjects
Physics, Radio galaxy, Astrophysics::High Energy Astrophysical Phenomena, Milky Way, Gamma ray, General Physics and Astronomy, Cosmic ray, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Electron, Galaxy, Energetic Gamma Ray Experiment Telescope, Small Magellanic Cloud, Astrophysics::Galaxy Astrophysics
Abstract

Observations of the Small Magellanic Cloud using the Energetic Gamma Ray Experiment Telescope on the Compton Observatory yield an upper limit (95% confidence) for gamma-ray emission g100 MeV of 0.5\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}7}$ photon/${\mathrm{cm}}^{2}$ s. The expected flux if the cosmic rays are universal rather than galactic in origin, is (2.4-0.5)\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}7}$ photon/${\mathrm{cm}}^{2}$ s, only a third of which arise from cosmic ray electron interactions. Hence, the bulk of the cosmic ray energy density is almost certainly not metagalactic, and therefore galactic in origin.

Published
1993

62. Multifrequency studies of the enigmatic gamma-ray source 3EG J1835+5918

Author

Gottfried Kanbach, K. T. S. Brazier, P. L. Nolan, D. J. Thompson, Olaf Reimer, and A. Carraminana

Subjects
Physics, biology, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), Gamma ray, Flux, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Radiation, biology.organism_classification, law.invention, Telescope, Neutron star, Pulsar, Space and Planetary Science, law, Egret, Optical identification
Abstract

The EGRET telescope has repeatedly observed 3EG J1835+5918 as a bright and steady source of high-energy gamma-ray radiation which has not yet been indentified. EGRET data from CGRO observation cycle 1 to 7 have been reanalysed above 100 MeV and above 1 GeV. The gamma-ray source location represents the latest and probably final positional assessment based on EGRET data. We especially adress the question of flux variability and spectral variability. The results of a X-ray/optical identification campaign towards 3EG J1835+5918 are given. The one object which might be associated with the gamma-ray source 3EG J1835+5918 has the characteristics of an isolated neutron star and possible of a radio-quiet pulsar., Comment: 8 pages, 5 figures, accepted for publication in MNRAS

Published
2001
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63. Feasibility studies of coded masks for high-energy gamma-ray telescopes in space

Author

P. F. Michelson, P. L. Nolan, D. J. Thompson, and Y. C. Lin

Subjects
Physics, High energy, Point source, business.industry, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Gamma ray, Field of view, Gamma-ray astronomy, Space (mathematics), Optics, Spitzer Space Telescope, Angular resolution, business
Abstract

It is a well-known fact that the high-energy gamma-ray telescopes in conventional designs are inherently limited in their spatial resolving powers. EGRET can locate a point source to 5 to 10 arcmin accuracy, while GLAST can achieve source location capabilities to better than 0.5 arcmin. Although there is still room for improvement in the angular resolution of the conventional high-energy gamma-ray telescopes, other means can also be explored at this time. Coded masks have been successfully used for X-ray and low-energy gamma-ray telescopes. Such devices have also been considered for high-energy gamma-ray telescopes from time to time. In this paper we investigate the feasibility of using coded masks to achieve much higher source location capabilities for a high-energy gamma-ray space telescope. We discuss the merits and the difficulties of using coded masks to achieve this goal. In particular, we look into the issues of size, weight, field of view, and the trade-off between the angular resolution and the f...

Published
2001

64. Results from the beam test of the engineering model of the GLAST large area telescope

Author

Hartmut Sadrozinski, Elliott D. Bloom, Bernard F. Phlips, B. Giebels, A. A. Moiseev, D. J. Thompson, R. Dubois, A. Chekhtman, B. Baughman, R. Arnold, N. Cotton, A. Djannati-Ataï, E. Do Couto E Silva, T. Hansl-Kozanecka, R. Terrier, P. M. Saz Parkinson, A. P. Waite, S. Gillespie, M. Frigaard, M. Hicks, Jonathan F. Ormes, G. Winker, T. Ohsugi, J. R. Bogart, P.L. Anthony, W. Kroeger, S. Ritz, J. L. Evans, J. Wallace, D. Tournear, W. N. Johnson, T. Handa, T. Fieguth, J.A. Hernando, Stephen M. Rock, J. J. Russel, M. Nikolaou, Yiing Lin, J. Silvis, D. Lauben, R. Williamson, D. Engovatov, B. Bumala, Gwelen Paliaga, T. Lindner, P. Bosted, T. Kamae, P. Espigat, A. Crider, D. Flath, Peter F. Michelson, Z. M. Szalata, P. L. Nolan, S. H. Williams, M. Hirayama, Ian Dobbs-Dixon, T. Schalk, G. Godfrey, A.C. Odian, R. P. Johnson, J. E. Grove, H. Arrighi, Physique Corpusculaire et Cosmologie - Collège de France (PCC), and Collège de France (CdF (institution))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nuclear and High Energy Physics, Photon, Physics::Instrumentation and Detectors, 01 natural sciences, Particle detector, 030218 nuclear medicine & medical imaging, law.invention, Telescope, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], 03 medical and health sciences, 0302 clinical medicine, Data acquisition, Optics, law, 0103 physical sciences, Instrumentation, Physics, 010308 nuclear & particles physics, business.industry, Gamma ray, Calorimeter, Physics::Accelerator Physics, Photon beams, High Energy Physics::Experiment, business, Beam (structure)
Abstract

This paper describes the results of a beam test using the Engineering Model of the GLAST Large Area Telescope, which was installed in a beam of positrons, hadrons and tagged photons at SLAC. The performance of the four subsystems, Anti Coincidence Detector, Silicon Tracker, Calorimeter and Data Acquisition will be described.

Published
2001

65. Some aspects of the radio emission of EGRET-detected blazars

Author

P. L. Nolan, R. C. Hartman, D. J. Thompson, D. L. Bertsch, Steven D. Bloom, A. Mücke, H. A. Mayer-Hasselwander, Peter F. Michelson, Olaf Reimer, Reshmi Mukherjee, Y. C. Lin, M. Pohl, J. A. Esposito, D. A. Kniffen, Stanley D. Hunter, and Gottfried Kanbach

Subjects
Physics, biology, Astrophysics::High Energy Astrophysical Phenomena, Radio flux, Astronomy, Flux, Quasar, Gamma ray spectra, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Gamma-ray astronomy, biology.organism_classification, Egret, Blazar, Astrophysics::Galaxy Astrophysics
Abstract

It has long been recognized that the high-latitude EGRET sources can be identified with blazars of significant radio emission. Many aspects of the relation between high-energy gamma-ray emission and radio emission of EGRET-detected blazars remain uncertain. In this paper, we use the results of the recently published Third EGRET Source Catalog to examine in more detail to what extent the EGRET flux and the radio flux are correlated. In particular we examine the correlation (or the lack of it) in flux level, spectral shape, temporal variation, and detection limit. Many significant previous studies in these areas are also evaluated.

Published
2000

66. Multiwavelength studies of the peculiar gamma-ray source 3EG J1835+5918

Author

K. T. S. Brazier, P. L. Nolan, Olaf Reimer, G. Kanbach, Alberto Carramiñana, and D. J. Thompson

Subjects
Physics, biology, Pulsar, ROSAT, Gamma ray, Egret, Astronomy, Astrophysics, Gamma-ray astronomy, Emission spectrum, Galactic plane, biology.organism_classification, Gamma-ray burst
Abstract

The source 3EG J1835+5918 was discovered early in the CGRO mission by EGRET as a bright unidentified γ-ray source outside the galactic plane. Especially remarkable, it has not been possible to identify this object with any known counterpart in any other wavelengths band since then. Analyzing our recent ROSAT HRI observation, for the first time we are able to suggest X-ray counterparts of 3EG J1835+5918. The discovered X-ray sources were subject of deep optical investigations in order to reveal their nature and conclude on the possibility of being counterparts for this peculiar γ-ray source.

Published
2000

67. GeV emission from the nearby radio galaxy Centaurus A

Author

R. C. Hartman, P. Sreekumar, D. J. Thompson, P. L. Nolan, and D. L. Bertsch

Subjects
Physics, Active galactic nucleus, biology, Radio galaxy, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), Centaurus A, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, biology.organism_classification, Luminosity, Egret, Blazar, Astrophysics::Galaxy Astrophysics
Abstract

EGRET has detected 67 sources associated with active galactic nuclei. With the exception of radio galaxy Cen A, all are classified as belonging to the blazar class of active galactic nuclei. The cumulative exposure from multiple EGRET observations has provided the first clear detection of Centaurus A. Unlike the \gr blazars seen by EGRET which are believed to exhibit near-alignment of the central jet along the line-of-sight, Cen A provides the first evidence for $>$100 MeV emission from a source with a confirmed large-inclination jet. Although the high-energy emission represents a lower luminosity than most EGRET blazars, with the advent of new more sensitive instruments such as GLAST and VERITAS, the detection of off-axis high-energy emission from more distant radio galaxies is an exciting possibility., 4 pages. accepted for publication in Astroparticle Physics

Published
1999

68. Beam Test of Gamma-ray Large Area Space Telescope Components

Author

Peter F. Michelson, Hartmut Sadrozinski, W. Kröger, P. Fleury, W. F. Tompkins, Jay P. Norris, A. A. Moiseev, W. N. Johnson, R. P. Johnson, C. Chaput, W. B. Atwood, C. Meetre, B.B. Jones, J.A. Hernando, G. Godfrey, R. Erickson, J. E. Grove, Yiing Lin, D. Engovatov, A. Pocar, X. Chen, Peter Milne, P. L. Nolan, M. J. Oreglia, D. J. Thompson, D.L. Chenette, S. Jaggar, M. Hirayama, P. Anthony, S. Ritz, R. Gearhart, J. Bourotte, Elliott D. Bloom, Bernard F. Phlips, Z. M. Szalata, Jonathan F. Ormes, T. Fieguth, and P. E. Bosted

Subjects
Physics, Nuclear and High Energy Physics, Physics - Instrumentation and Detectors, business.industry, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Gamma ray, FOS: Physical sciences, Instrumentation and Detectors (physics.ins-det), Particle detector, Charged particle, Linear particle accelerator, Space Physics (physics.space-ph), Calorimeter, Optics, Physics - Space Physics, Spitzer Space Telescope, Measuring instrument, Physics::Accelerator Physics, High Energy Physics::Experiment, business, Instrumentation, Beam (structure)
Abstract

A beam test of GLAST (Gamma-ray Large Area Space Telescope) components was performed at the Stanford Linear Accelerator Center in October, 1997. These beam test components were simple versions of the planned flight hardware. Results on the performance of the tracker, calorimeter, and anti-coincidence charged particle veto are presented., Comment: 39 pages, 21 figures

Published
1999
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69. EGRET observations of PKS 0528+134 from 1991 to 1997

Author

A. Witzel, Alan P. Marscher, R. C. Hartman, D. J. Thompson, Alex Kraus, E. Valtaoja, A. Mücke, H. Teräsranta, Reshmi Mukherjee, S. J. Wagner, M. Pohl, Stanley D. Hunter, P. F. Michelson, C. von Montigny, P. Sreekumar, Merja Tornikoski, E. J. Schneid, D. A. Kniffen, Brenda Dingus, Thomas P. Krichbaum, J. A. Esposito, Steven D. Bloom, H. A. Mayer-Hasselwander, Gottfried Kanbach, W. A. Mahoney, Olaf Reimer, P. L. Nolan, D. L. Bertsch, and Y. C. Lin

Subjects
Physics, Active galactic nucleus, biology, Astrophysics::High Energy Astrophysical Phenomena, Gamma ray, Flux, Astronomy, Quasar, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, biology.organism_classification, Spectral line, Egret, Spectral analysis, Gamma-ray burst, Astrophysics::Galaxy Astrophysics
Abstract

The compact, radio-loud quasar PKS 0528+134 has been one of the brightest active galactic nuclei (AGN) detected by EGRET. The flux history of the source including data up to March 1997, as well as the spectra measured during the flaring and non-flaring states is presented. Multiwavelength observations of PKS 0528+134 are also presented. A detailed relativistic SSC jet model agrees well with the multiwavelength spectrum; the data, however are insufficient to discriminate between this and other emission models.

Published
1997

70. Temporal and spectral studies of unidentified EGRET high latitude sources

Author

D. L. Bertsch, C. V. Montigny, Y. C. Lin, D. A. Kniffen, P. L. Nolan, J. A. Esposito, O. Reimer, Brenda Dingus, R. Mukherjee, H. A. Mayer-Hasselwander, B. B. Jones, Stanley D. Hunter, Gottfried Kanbach, P. Sreekumar, W. F. Tompkins, R. C. Hartman, and D. J. Thompson

Subjects
Data set, Physics, biology, High latitude, Flux, Astronomy, Egret, Gamma ray spectra, Astrophysics, Gamma-ray burst, biology.organism_classification, Galaxy, Astronomical spectroscopy
Abstract

Source distribution studies only provide meaningful information if the basic populations are carefully determined, especially if the statistics are limited. This necessitates restrictions from the approach of using the complete EGRET source catalog data. Considering various peculiarities of the catalogs a more uniform data set is defined for further source distribution studies. Here, we focus on the temporal and spectral characteristic of the unidentified EGRET high latitude sources (|b|>10°). Variability is addressed on the basis of flux histories with timescales of individual viewing periods, and spectra are determined for all sources based on the enhanced statistics from EGRET observations of Phase 1 to 4. The derived features are used to discuss whether the unidentified high latitude sources show similarities or differences from classes of already identified objects, or if no conclusive answer can be given.

Published
1997

71. Phase-Resolved Studies of the High-Energy Gamma-Ray Emission from the Crab, Geminga, and Vela Pulsars

Author

Peter F. Michelson, D. J. Thompson, J. M. Fierro, and P. L. Nolan

Subjects
Physics, Spectral index, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), Gamma ray, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Vela, Spectral line, Crab Nebula, Pulsar, Space and Planetary Science, Observatory, Astrophysics::Galaxy Astrophysics, Fermi Gamma-ray Space Telescope
Abstract

Using the first three and a half years of observations from the Energetic Gamma Ray Telescope (EGRET) on board the Compton Gamma Ray Observatory (CGRO), phase-resolved analyses are performed on the emission from the three brightest high-energy gamma-ray pulsars, Crab, Geminga, and Vela. For each pulsar, it is found that there is detectable high-energy gamma-ray emission above the galactic diffuse background throughout much of the pulsar rotation cycle. A hardness ratio is introduced to characterize the evolution of the spectral index as a function of pulsar phase. While the hardest emission from the Crab and Vela pulsars comes from the bridge region between the two gamma-ray peaks, the hardest emission from Geminga corresponds to the second gamma-ray peak. For all three pulsars, phase-resolved spectra of the pulse profile components reveal that although there is a large variation in the spectral index over the pulsar phase interval, the high-energy spectral turnover, if any, occurs at roughly the same energy in each component. The high-energy gamma-ray emission from the Crab complex appears to include an unpulsed ultra-soft component of spectral index ~ -4.3 which dominates the total emission below 100 MeV. This component is consistent with the expected emission from the tail end of the Crab nebula synchrotron emission., Comment: 20 pages, 11 figures, 7 tables. Accepted for publication in the Astrophysical Journal

Published
1997
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72. EGRET Observations of the Extragalactic Gamma Ray Emission

Author

P. Sreekumar, D. L. Bertsch, B. L. Dingus, J. A. Esposito, C. E. Fichtel, R. C. Hartman, S. D. Hunter, G. Kanbach, D. A. Kniffen, Y. C. Lin, H. A. Mayer‐Hasselwander, P. F. Michelson, C. von Montigny, A. Mucke, R. Mukherjee, P. L. Nolan, M. Pohl, O. Reimer, E. Schneid, J. G. Stacy, F. W. Stecker, D. J. Thompson, and T. D. Willis

Subjects
Physics, Photon, biology, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), Gamma ray, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Radiation, biology.organism_classification, Galaxy, Space and Planetary Science, Observatory, Egret, Energetic Gamma Ray Experiment Telescope, Blazar, Astrophysics::Galaxy Astrophysics
Abstract

The all-sky survey in high-energy gamma rays (E$>$30 MeV) carried out by the Energetic Gamma Ray Experiment Telescope (EGRET) aboard the Compton Gamma-Ray Observatory provides a unique opportunity to examine in detail the diffuse gamma-ray emission. The observed diffuse emission has a Galactic component arising from cosmic-ray interactions with the local interstellar gas and radiation as well an almost uniformly distributed component that is generally believed to originate outside the Galaxy. Through a careful study and removal of the Galactic diffuse emission, the flux, spectrum and uniformity of the extragalactic emission is deduced. The analysis indicates that the extragalactic emission is well described by a power law photon spectrum with an index of -(2.10+-0.03) in the 30 MeV to 100 GeV energy range. No large scale spatial anisotropy or changes in the energy spectrum are observed in the deduced extragalactic emission. The most likely explanation for the origin of this extragalactic high-energy gamma-ray emission is that it arises primarily from unresolved gamma-ray-emitting blazars., 19 pages latex, 10 figures, accepted for publication in ApJ

Published
1997
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73. EGRET observations of PKS 2005−489

Author

A. Mücke, H. A. Mayer-Hasselwander, Steven D. Bloom, J. A. Esposito, Reshmi Mukherjee, P. F. Michelson, C. von Montigny, B. B. Jones, Stanley D. Hunter, D. J. Thompson, P. Sreekumar, E. J. Schneid, Brenda Dingus, Olaf Reimer, D. A. Kniffen, W. F. Tompkins, Gottfried Kanbach, M. Pohl, Y. C. Lin, P. L. Nolan, and D. L. Bertsch

Subjects
Physics, Active galactic nucleus, biology, media_common.quotation_subject, Astronomy, Context (language use), Maximum likelihood analysis, Astrophysics, Software package, biology.organism_classification, Sky, Aspect angle, Egret, Gamma-ray burst, media_common
Abstract

PKS 2005−489, at z=0.071, is one of the closest BL Lacertae objects, bright in radio to X-ray wavebands. It has been in EGRET’s field of view a total of six times within an aspect angle of 30° from Phase 1 to Phase 3 (1991 May to 1994 October), none afterwards. But the total EGRET exposure to this region of the sky was still rather low. PKS 2005−489 was listed in the First EGRET Catalog at the significance TS=4.3, in the context of the maximum likelihood analysis adopted by the EGRET team as part of the standard EGRET software package. Later when the EGRET data were reanalyzed with revised software and improved diffuse model to generate the Second EGRET Catalog, the detection significance of PKS 2005−489 was found to be at TS=3.8, slightly below the TS=4.0 cut line to qualify for an entry in the Second EGRET Catalog. The status of EGRET results on PKS 2005−489 at this time is presented in this paper.

Published
1997

74. EGRET observations of X-ray binaries

Author

Y. C. Lin, W. F. Tompkins, P. F. Michelson, B. B. Jones, Mallory S. E. Roberts, and P. L. Nolan

Subjects
Physics, biology, Maximum likelihood, Modulation (music), Gamma ray, X-ray binary, Egret, Astronomy, Gamma ray spectra, Astrophysics, Gamma-ray burst, biology.organism_classification
Abstract

Several known low- and high-mass X-ray binaries with orbital periods between tens of minutes and several days were examined in EGRET data. Instrument thresholds for orbital modulation were calculated, and appropriate observations were analyzed with new software which uses maximum likelihood methods for signal detection, fully accounting for variations in EGRET exposure, as well as the structured gamma-ray background and the energy-dependent point-spread function. While some sources were not detected by EGRET at all, several were marginally detected with less than 5 σ significance. However, due to significant background and low statistics, the observations were unable to constrain the modulation fraction of any of the sources.

Published
1997

75. ERRATUM: 'CONSTRAINTS ON THE COSMIC-RAY DENSITY GRADIENT BEYOND THE SOLAR CIRCLE FROM FERMI γ-RAY OBSERVATIONS OF THE THIRD GALACTIC QUADRANT' (2011, ApJ, 726, 81)

Author

Francesco Longo, A. Chekhtman, J. Mehault, R. Dubois, A. W. Borgland, W. B. Focke, Eric Charles, P. L. Nolan, D. Parent, P. Spinelli, T. Uehara, D. J. Suson, Francesco Giordano, Nicola Omodei, M. Ziegler, Pierrick Martin, Joachim Ripken, R. A. Cameron, Hiromitsu Takahashi, S. Murgia, Jean Ballet, Andrey Vladimirov, P. Wang, P. Bruel, F. Piron, P. Lubrano, Julie McEnery, Yasunobu Uchiyama, E. Orlando, Stefano Ciprini, R. Buehler, P. Fusco, Emanuele Bonamente, Hartmut Sadrozinski, Melissa Pesce-Rollins, R. Claus, Alice K. Harding, J. M. Casandjian, Peter F. Michelson, Tadayuki Takahashi, Marcello Giroletti, Ryosuke Itoh, Marco Ajello, Sho Nishino, J. B. Thayer, Elliott D. Bloom, Luca Baldini, A. Tramacere, G. Godfrey, Ronaldo Bellazzini, Hideaki Katagiri, A. Makeev, Takaaki Tanaka, T. J. Brandt, K. Hayashi, Igor V. Moskalenko, M. E. Monzani, S. Rainò, Zhenwei Yang, Tsunefumi Mizuno, Mn Mazziotta, Carmelo Sgrò, Riccardo Rando, T. Ohsugi, F. de Palma, F. Loparco, Olaf Reimer, S. Buson, Yasushi Fukazawa, Jan Conrad, T. A. Porter, R. E. Hughes, Shiu-Hang Lee, V. Pelassa, E. Nuss, Seth Digel, Charles D. Dermer, Claudia Cecchi, L. Tibaldo, M. Kuss, Diego F. Torres, Daniela Hadasch, M. Ozaki, D. J. Thompson, J. F. Ormes, A. P. Waite, C. Favuzzi, J. P. Norris, A. Morselli, V. Vitale, J. Bregeon, M. Razzano, T. Sada, Stefan Funk, S. Germani, K. S. Wood, T. Kamae, W. N. Johnson, B. Berenji, Keith Bechtol, A. Reimer, Gudlaugur Johannesson, Justin Vandenbroucke, Guido Barbiellini, M. Brigida, E. J. Siskind, M. Hayashida, C. Monte, N. Vilchez, Jun Kataoka, Markus Ackermann, M. Llena-Garde, Andrew W. Strong, A. S. Johnson, M. Pepe, T. Glanzman, Jürgen Knödlseder, Y. Hanabata, V. Vasileiou, F. Gargano, Luca Latronico, Nicola Giglietto, Denis Bastieri, M. N. Lovellette, P. A. Caraveo, James Chiang, Elizabeth C. Ferrara, Alessandro Brez, Persis S. Drell, I. A. Grenier, T. L. Usher, Atsushi Okumura, Gloria Spandre, J. Lande, Sylvain Guiriec, Johann Cohen-Tanugi, M. Naumann-Godo, M. S. Strickman, and G. A. Caliandro

Subjects
Physics, Density gradient, Space and Planetary Science, Galactic quadrant, Astronomy, Astronomy and Astrophysics, Cosmic ray, Astrophysics, Fermi Gamma-ray Space Telescope
Published
2013

76. TASC measurements/upper limits for energetic gamma-ray bursts within the EGRET field of view

Author

C. E. Fichtel, P. L. Nolan, J. R. Catelli, D. L. Bertsch, H. A. Mayer-Hasselwander, Gottfried Kanbach, J. A. Esposito, R. C. Hartman, D. J. Thompson, Reshmi Mukherjee, Y. C. Lin, Stanley D. Hunter, D. A. Kniffen, P. F. Michelson, P. Sreekumar, E. J. Schneid, C. von Montigny, and Brenda Dingus

Subjects
Physics, biology, Gamma ray, Egret, Astronomy, Field of view, Astrophysics, biology.organism_classification, Gamma-ray burst
Abstract

For the period from launch in April 1991 to present, EGRET had reported on the detection of seven energetic gamma-ray bursts. A systematic analysis of the Total Absorption Shower Counter (TASC) data has been made for bursts within the EGRET field of view. Spectral indexes are given for these bursts detected by EGRET and upper limits are given for bursts detected by COMPTEL and not by EGRET.

Published
1996

77. Continuing search of the EGRET data for high-energy gamma-ray microsecond bursts

Author

P. L. Nolan, D. L. Bertsch, D. A. Kniffen, C. E. Fichtel, Y. C. Lin, L. M. McDonald, Stanley D. Hunter, P. Sreekumar, E. J. Schneid, Brenda Dingus, J. A. Esposito, R. C. Hartman, D. J. Thompson, Gottfried Kanbach, H. A. Mayer-Hasselwander, Reshmi Mukherjee, P. F. Michelson, and C. von Montigny

Subjects
Physics, biology, Astrophysics::High Energy Astrophysical Phenomena, media_common.quotation_subject, Gamma ray, Astronomy, Particle accelerator, Astrophysics, biology.organism_classification, Universe, law.invention, Black hole, General Relativity and Quantum Cosmology, Microsecond, law, Egret, Stellar black hole, Gamma-ray burst, media_common
Abstract

In the mid 1970’s Hawking (1) and Page and Hawking (2), investigated theoretically the possibility of detecting high-energy gamma rays produced by the quantum-mechanical decay of a small black hole created in the early universe. They concluded that, at the end of the life of the small black hole, it would radiate a burst of gamma rays peaked near 250 MeV with a total energy of about 1034 ergs in the order of a microsecond or less if certain details of the theory were true. The characteristics of a black hole are determined by laws of physics beyond the range of current particle accelerators; hence, the search for these short bursts of high-energy gamma rays provides at least the possibility of detecting directly the gamma rays from such bursts, and a search of the EGRET data has led to an upper limit below 5×10−2 black hole decays per pc3 yr−1, placing constraints on this and other theories predicting microsecond high-energy gamma-ray bursts.

Published
1996

78. High-Energy Gamma Rays from PKS 1406−076 and the Observation of Correlated Gamma-Ray and Optical Emission

Author

P. L. Nolan, D. L. Bertsch, J. R. Mattox, R. C. Hartman, D. J. Thompson, Stanley D. Hunter, P. Sreekumar, Ulrich Hopp, Peter F. Michelson, C. E. Fichtel, D. A. Kniffen, Yiing Lin, H. A. Mayer-Hasselwander, Jochen Heidt, Gottfried Kanbach, H. Bock, Stefan Wagner, Brenda Dingus, and C. von Montigny

Subjects
Physics, High energy, Active galactic nucleus, genetic structures, biology, Astrophysics::High Energy Astrophysical Phenomena, Gamma ray, Astronomy, Astronomy and Astrophysics, Quasar, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Radiation, biology.organism_classification, law.invention, Space and Planetary Science, law, Astrophysics::Solar and Stellar Astrophysics, Egret, sense organs, Blazar, Astrophysics::Galaxy Astrophysics, Flare
Abstract

We report simultaneous observations of the optically violent variable (OVV) quasar PKS 1406-076 in the optical and gamma-ray regime. Gamma-ray emission is detected with very high significance. Both the gamma-ray and optical properties of PKS 1406-076 are typical for the group of gamma-bright active galactic nuclei detected by EGRET. During 1993 January the source was unusually bright in both frequency ranges. During this period we observed a rapid, symmetrical flare in the optical wavelength range which lasted for about 4 days. EGRET detected a similar rapid flare peaking about 22 hr after the optical outburst. Because such rapid flares are rare events, it is likely that the outbursts in the two frequency regimes are correlated. Correlated outbursts with similar profiles and a lag between the optical and gamma-ray maxima of 22 hr are inconsistent with simple versions of models suggested for the emission of high-energy radiation from blazars.

Published
1995

79. EGRET Observations of Gamma Rays from Point Sources with Galactic Latitude +10(degrees) < b < +40(degrees)

Author

C. E. Fichtel, Peter F. Michelson, H. A. Mayer-Hasselwander, J. R. Mattox, Reshmi Mukherjee, R. C. Hartman, E. J. Schneid, C. von Montigny, D. J. Thompson, D. A. Kniffen, J. A. Esposito, Stanley D. Hunter, P. Sreekumar, J. M. Fierro, Brenda Dingus, T. D. Willis, Gottfried Kanbach, P. L. Nolan, D. L. Bertsch, James Chiang, and Y. C. Lin

Subjects
Physics, biology, Astrophysics::High Energy Astrophysical Phenomena, Gamma ray, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, biology.organism_classification, Latitude, Space and Planetary Science, Egret, Point (geometry), Astrophysics::Galaxy Astrophysics
Abstract

The EGRET instrument aboard the Compton Gamma Ray Observatory (CGRO) has completed the first all-sky survey in high-energy gamma rays and has repeatedly viewed selected portions of the sky. Analysis of the region with galactic latitude $+10\arcdeg < b < +40\arcdeg$ indicates the presence of nineteen point sources, including nine which can be identified as active galactic nuclei, some of which have been reported previously, as well as ten other sources with no definite counterparts. Using the combined exposures from Phase 1 and Phase 2 of the CGRO viewing program, the spectra, time variability, and positions of all detected sources in this region are determined. It is tentatively suggested that one of the unidentified sources might be associated with the radio galaxy Centaurus A., Comment: 18 pages, 3 Postscript figures (one of 3 pages) Uses aaspp4.sty

Published
1995

80. EGRET Detection of Pulsed Gamma Radiation from PSR B1951+32

Author

D. A. Kniffen, Andrew Lyne, J. A. Esposito, D. J. Thompson, H. A. Mayer-Hasselwander, Brenda Dingus, Yiing Lin, J. M. Fierro, P. L. Nolan, J. R. Mattox, Stanley D. Hunter, Reshmi Mukherjee, D. L. Bertsch, Gottfried Kanbach, C. von Montigny, M. Merck, C. E. Fichtel, P. V. Ramanamurthy, and Peter F. Michelson

Subjects
Physics, Spectral index, biology, Astrophysics::High Energy Astrophysical Phenomena, Gamma ray, Astronomy, Astronomy and Astrophysics, Astrophysics, Gamma-ray astronomy, Magnetar, biology.organism_classification, Pulsar, Space and Planetary Science, Observatory, Egret, Energetic Gamma Ray Experiment Telescope, Astrophysics::Galaxy Astrophysics
Abstract

We detected a sixth high-energy gamma-ray pulsar, PSR B1951+32, pulsating in gamma rays at E ≥ 100 MeV with the same 39.5 ms periodicity as in radio, using the data obtained during 1991 May to 1994 July by the Energetic Gamma Ray Experiment Telescope (EGRET) aboard the Compton Gamma Ray Observatory. Although seen only as a weak source amidst the high background of galactic disk emission, the pulsation in high-energy gamma rays is clearly seen. The pulsed radiation has a photon spectral index of -1.74 ± 0.11. There is no evidence as yet for unpulsed emission from the object. The pulsar appears to have an efficiency of ~0.004 for converting its rotational energy loss into gamma rays at E ≥ 100 MeV.

Published
1995

81. EGRET Observations of Active Galactic Nuclei

Author

R. C. Hartman, Stanley D. Hunter, D. J. Thompson, P. Sreekumar, E. J. Schneid, C. E. Fichtel, H. A. Mayer-Hasselwander, J. A. Esposito, James Chiang, T. D. Willis, J. M. Fierro, Brenda Dingus, Peter F. Michelson, D. A. Kniffen, C. von Montigny, J. R. Mattox, Y. C. Lin, P. L. Nolan, D. L. Bertsch, and Gottfried Kanbach

Subjects
Physics, Photon, Active galactic nucleus, biology, Infrared, Astrophysics::High Energy Astrophysical Phenomena, Gamma ray, Astronomy, Quasar, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, biology.organism_classification, Observatory, Egret, Blazar, Astrophysics::Galaxy Astrophysics
Abstract

The EGRET instrument on the Compton Gamma Ray Observatory, which detects photons in the energy range 30 MeV to 30 GeV, has detected about 40 sources of gamma rays (>100 MeV) at high galactic latitudes. Most of these appear to be associated with bright, flat-spectrum radio sources, many of which have been previously classified as optically violent variable (OVV) quasars or BL Lac objects (together often referred to as blazars). The remaining sources are presently unidentified, although some of them are positionally compatible with flat-spectrum radio sources which are somewhat less bright and less well-studied.

Published
1995

82. Observations of high-energy gamma-ray bursts with EGRET

Author

R. C. Hartman, D. J. Thompson, H. A. Mayer-Hasselzuander, D. A. Kniffen, Yiing Lin, Brenda Dingus, Reshmi Mukherjee, C. von Montigny, Stanley D. Hunter, P. Sreekumar, E. J. Schneid, Gottfried Kanbach, P. L. Nolan, M. Merck, D. L. Bertsch, Martin Pohl, Peter F. Michelson, and C. E. Fichtel

Subjects
Physics, biology, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Gamma ray, Astrophysics, biology.organism_classification, Cosmic string, Neutron star, Observatory, Egret, Energetic Gamma Ray Experiment Telescope, Spark chamber, Gamma-ray burst
Abstract

Gamma Ray Bursts (GRBs) have puzzled astronomers since their discovery more than 20 years ago. As no counterparts at wavelengths other than X- and γ-rays have yet been found the identification of the sources is still missing. Theoretical explanations range from colliding comets (1993) and merging neutron stars (1982) to more exotic objects, such as superconducting cosmic strings (1988). Data accumulated until now still do not discriminate between these models, although results from the BATSE (Burst and Transient Source Experiment) instrument aboard the Compton Gamma Ray Observatory ( CGRO ) strongly favor extragalactic models. The Energetic Gamma Ray Experiment Telescope ( EGRET ) aboard CGRO has s ofar detected photons from 5 GRBs with its spark chamber. These are the highest energy γ-rays associated with GRBs to date. In this work we review previously published data and summarize the properties of these events. Elsewhere we present possible constraints from the data on the models proposed to explain GRBs.

Published
1995

83. EGRET data reduction and analysis

Author

H. A. Mayer-Hasselwander, R. C. Hartman, D. J. Thompson, P. F. Michelson, C. von Montigny, P. L. Nolan, D. A. Kniffen, Brenda Dingus, C. E. Fichtel, J. A. Esposito, Stanley D. Hunter, P. Sreekumar, D. L. Bertsch, E. J. Schneid, Y. C. Lin, J. R. Mattox, Gottfried Kanbach, and J. M. Fierro

Subjects
Physics, Data processing, Information retrieval, biology, Calibration (statistics), business.industry, Astronomy, biology.organism_classification, Data type, law.invention, Telescope, Software, law, Data analysis, Egret, business, Data reduction
Abstract

This paper provides a summary of the data reduction and analysis procedures used by the Energetic Gamma Ray Experimental Telescope (EGRET) team. The steps are summarized beginning with the extensive calibration, proceeding to the basic data reduction, and finishing with the data analysis techniques, including a brief description of the source determination, the intensity calculation, the spectral evaluation, the pulsar program, and time variations. References are provided for the detailed discussions of the major portions of the work. The types of data and the software available to Guest Investigators are also reviewed with guides to more detailed descriptions. In this way, the overview is given in one place with references for those wishing to see parts in detail.

Published
1994

84. EGRET observations of extended high-energy emissions from the nuclear line flares of June 1991

Author

D. A. Kniffen, C. E. Fichtel, J. R. Mattox, Gottfried Kanbach, Y. C. Lin, R. C. Hartman, H. A. Mayer-Hasselwander, D. J. Thompson, P. L. Nolan, K. T. S. Brazier, D. L. Bertsch, E. J. Schneid, Brenda Dingus, P. F. Michelson, C. von Montigny, Stanley D. Hunter, and P. Sreekumar

Subjects
Physics, biology, Spectrometer, Solar flare, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Gamma ray, Astronomy, Astrophysics, biology.organism_classification, law.invention, Observatory, law, Physics::Space Physics, Astrophysics::Solar and Stellar Astrophysics, Egret, Spark chamber, Astrophysics::Galaxy Astrophysics, Flare, Line (formation)
Abstract

EGRET onboard the Compton Gamma Ray Observatory observed four energetic X‐type solar flares during June 1991. Two of these flares were in the EGRET spark chamber field of view and were observed to have high energy gamma ray emission lasting hours after the impulsive phase of the flare. Measurements of all four flares were obtained by the EGRET large NaI spectrometer.

Published
1994

85. Egret observation of the June 30 and July 2, 1991 energetic solar flares

Author

R. C. Hartman, D. J. Thompson, Brenda Dingus, P. L. Nolan, D. L. Bertsch, P. F. Michelson, C. von Montigny, E. J. Schneid, J. R. Mattox, H. A. Mayer-Hasselwander, Gottfried Kanbach, D. A. Kniffen, K. T. S. Brazier, Y. C. Lin, Stanley D. Hunter, P. Sreekumar, and C. E. Fichtel

Subjects
Physics, Spectrometer, biology, Solar flare, Astrophysics::High Energy Astrophysical Phenomena, Bremsstrahlung, Gamma ray, Astronomy, Astrophysics, biology.organism_classification, Spectral line, On board, Observatory, Egret
Abstract

The EGRET experiment on board the Compton Gamma Ray Observatory observed energetic gamma rays from the impulsive solar flares on June 30 and July 2, 1991. The June 20 and July 2 spectra were measured by the large NaI spectrometer in EGRET and extended up to nearly ∼50 MeV and ∼10 MeV respecetively before appearing to cut off. These spectra can be fit by a power law model or an isothermal plasma model.

Published
1994

87. Variability of EGRET-detected active galaxies and acceleration mechanisms

Author

Brenda Dingus, J. R. Mattox, K. T. S. Brazier, Peter F. Michelson, C. E. Fichtel, Stanley D. Hunter, P. Sreekumar, R. C. Hartman, J. A. Esposito, E. J. Schneid, T. D. Willis, C. von Montigny, D. J. Thompson, D. A. Kniffen, H. A. Mayer-Hasselwander, Gottfried Kanbach, J. Chiang, Y. C. Lin, P. L. Nolan, D. L. Bertsch, and J. M. Fierro

Subjects
Physics, Active galactic nucleus, biology, Astrophysics::High Energy Astrophysical Phenomena, Gamma ray, Astronomy, Optical polarization, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, biology.organism_classification, Radio spectrum, Observatory, Egret, Energetic Gamma Ray Experiment Telescope, Blazar, Astrophysics::Galaxy Astrophysics
Abstract

The Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Observatory has detected, with a high degree of certainty, more than 20 active galactic nuclei (AGN) in high energy gamma‐ray (E≳100 MeV). All of these sources appear to be members of the blazar class of AGN, exhibiting one or more of the characteristics of this source class (flat radio spectrum, strong variability, optical polarization).Variability on time scales from days to months or longer is a characteristic of the gamma‐ray emission from most of the blazars detected by EGRET. In this paper the EGRET observations of variability are summarized and some of the implications for emission models are discussed. In particular, the EGRET observations and consideration of gamma‐ray absorption via photon‐photon pair production strongly suggest that the gamma radiation from AGN is beamed toward us. This is consistent with the interpretation of blazars as objects in which the non‐thermal radiation arises predominantly from a ‘‘jet’’ of relativis...

Published
1994

88. The luminosity function of EGRET-detected gamma-ray loud active galactic nuclei

Author

Gottfried Kanbach, E. J. Schneid, H. A. Mayer-Hasselwander, R. C. Hartman, D. J. Thompson, D. L. Bertsch, P. L. Nolan, Stanley D. Hunter, P. Sreekumar, T. D. Willis, Peter F. Michelson, C. E. Fichtel, Y. C. Lin, James Chiang, K. T. S. Brazier, J. M. Fierro, J. A. Esposito, H. D. Radecke, Brenda Dingus, J. R. Mattox, C. von Montigny, and D. A. Kniffen

Subjects
Physics, education.field_of_study, Active galactic nucleus, biology, Astrophysics::High Energy Astrophysical Phenomena, Population, Gamma ray, Astronomy, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, biology.organism_classification, Cosmology, Luminosity, Observatory, Egret, education, Astrophysics::Galaxy Astrophysics, Luminosity function (astronomy)
Abstract

The EGRET instrument aboard the Compton Gamma‐Ray Observatory has detected gamma‐ray emission from many Active Galactic Nuclei during the Phase I & II observation periods. With the continuing discovery of gamma‐ray loud AGN, it becomes increasingly important to characterize the luminosity and density distribution of these objects in order to understand how the gamma‐ray characteristics are related to properties observed at radio, optical and X‐ray wavelengths. The 〈V/Vmax〉 test is applied to the population of gamma‐ray loud Active Galactic Nuclei which have been observed by the EGRET instrument during the Phase I all‐sky survey. Evidence for luminosity evolution is presented, and estimates of the degree of evolution are made given standard assumptions about the cosmology and the form of the luminosity evolution. The effects of observational biases due to gamma‐ray flux‐detection limits and optical identifications are considered.

Published
1994

89. Comparison of BATSE, COMPTEL, EGRET, and OSSE spectra of GRB 910601

Author

G. H. Share, W. N. Johnson, J. D. Kurfess, R. J. Murphy, A. Connors, B. L. Dingus, B. E. Schaefer, D. Band, J. Matteson, W. Collmar, V. Schönfelder, C. E. Fichtel, P. W. Kwok, B. J. Teegarden, G. Fishman, L. Kuiper, G. V. Jung, S. M. Matz, P. L. Nolan, E. J. Schneid, and C. Winkler

Subjects
Physics, biology, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Gamma ray, Astronomy, Astrophysics, biology.organism_classification, Spectral line, Observatory, Egret, Gamma spectroscopy, Gamma-ray burst, Spectroscopy
Abstract

GRB 910601 was well observed by all three broad‐field experiments on the COMPTON Observatory; it was also at a known position within the narrow aperture of the OSSE instrument. This has permitted us to compare spectra observed from all four of the COMPTON Observatory instruments. The burst lasted for about 40 s and was observed into the MeV region by all of the detectors; it was not detected at energies above 10 MeV. Time‐integrated spectra from COMPTEL, EGRET, and OSSE are in good agreement. Spectra from both the BATSE large area and spectroscopy detectors during the early part of the burst are also in good agreement with the OSSE spectrum.

Published
1994

90. EGRET observations of three gamma-ray bursts at energies ≳30 MeV

Author

P. F. Michelson, B. L. Dingus, C. von Montigny, H. A. Mayer-Hasselwander, Kevin Hurley, Gottfried Kanbach, J. R. Mattox, C. E. Fichtel, M. Sommer, R. C. Hartman, Alice K. Harding, D. J. Thompson, D. A. Kniffen, P. L. Nolan, Stanley D. Hunter, D. L. Bertsch, P. Sreekumar, E. J. Schneid, and Y. C. Lin

Subjects
Physics, Amplitude, biology, Astrophysics::High Energy Astrophysical Phenomena, Gamma ray, Egret, Astrophysics, Light curve, Gamma-ray burst, biology.organism_classification, Fluence, Order of magnitude, Intensity (physics)
Abstract

EGRET has imaged three gamma‐ray bursts at energies above 30 MeV. The bursts are GRB930131, GRB910503, and GRB910601—listed in order of decreasing intensity. GeV emission has been detected in two bursts which increases by an order of magnitude the maximum energy gamma rays observed from a gamma‐ray burst. The high energy emission is a significant contributor to the fluence of these burst, and the duration of the high energy emission is at least as long and in some cases longer than the emission observed by BATSE. The high energy gamma rays are also used to determine the most probable direction of the burst.

Published
1994

91. Timing the Geminga pulsar with high-energy gamma rays

Author

R. C. Hartman, D. A. Kniffen, D. J. Thompson, Stanley D. Hunter, P. Sreekumar, J. M. Fierro, James Chiang, E. J. Schneid, H. A. Mayer-Hasselwander, K. T. S. Brazier, H. D. Radecke, T. D. Willis, C. E. Fichtel, P. L. Nolan, D. L. Bertsch, Gottfried Kanbach, Y. C. Lin, J. A. Esposito, J. R. Mattox, Brenda Dingus, P. F. Michelson, and C. von Montigny

Subjects
Physics, High energy, Pulsar, biology, Gamma ray, Astronomy, Egret, Astrophysics, Light curve, Ephemeris, biology.organism_classification
Abstract

The EGRET phase 1 & 2 observations of Geminga have been used to determine an optimum contemporary ephemeris using the ‘‘Z2n timing method.’’ The residuals for this linear ephemeris over 2.1 years are less than 5 ms, suggesting that Geminga has not glitched. A position estimate is found to be consistent with the G‘ optical counterpart. The comparison of f between this ephemeris and that of COS‐B yields an estimate of f which is an order of magnitude smaller than that determined from the COS‐B data. It is estimated that the anticipated EGRET phase 3 Geminga exposure will allow for the comparison of Geminga phase between EGRET, COS‐B, and SAS‐2.

Published
1994

92. The unidentified gamma ray source GRO J1837+59

Author

J. M. Fierro, J. R. Mattox, H. D. Radeck, D. A. Kniffen, K. T. S. Brazier, Gottfried Kanbach, R. C. Hartman, D. J. Thompson, H. A. Mayer-Hasselwander, Brenda Dingus, J. A. Esposito, C. von Montigny, P. L. Nolan, Stanley D. Hunter, P. Sreekumar, D. L. Bertsch, E. J. Schneid, C. E. Fichtel, T. D. Willis, Peter F. Michelson, Y. C. Lin, and James Chiang

Subjects
Physics, High energy, biology, Astrophysics::High Energy Astrophysical Phenomena, Gamma ray, Astronomy, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, biology.organism_classification, Latitude, law.invention, Telescope, Radiation flux, law, Egret, Blazar, Gamma-ray burst, Astrophysics::Galaxy Astrophysics
Abstract

The EGRET gamma‐ray telescope has detected a persistent source of high energy gamma rays which has not been identified. It was detected in seven different observations in 1991–1993. Variations in the spectrum, combined with a galactic latitude of +25°, make it likely that this is a previously unknown blazar.

Published
1994

93. The Crab unpulsed spectrum: New results and interpretation

Author

Alice K. Harding, P. L. Nolan, P. Sreekumar, H. I. Nel, Peter F. Michelson, O. C. De Jager, and D. J. Thompson

Subjects
Physics, Spectral index, Pair production, Crab Nebula, biology, Pulsar, Astrophysics::High Energy Astrophysical Phenomena, Gamma ray, Compton scattering, Egret, Synchrotron radiation, Astrophysics, biology.organism_classification
Abstract

The unpulsed spectrum of Crab as seen by EGRET appears to be inconsistent with a single power law: there is a flattening above 1 GeV, and when combined with the Comptel unpulsed spectrum, shows evidence of a rollover above 30 MeV. The unpulsed flux in the 70 MeV to 1 GeV interval appears to have decreased between 1991 and 1993. The significance of this decrease is ∼3.3 σ. Such a cutoff below a GeV was indeed predicted by De Jager & Harding (1992) as synchrotron radiation by the highest energy electrons/positrons at the pulsar wind shock. The EGRET data suggests a maximum electron energy of 2 PeV, which is comfortably within the limits predicted by diffusive work drift acceleration. However, above 1 GeV we see evidence of a flat but steady spectral component extending out to at least 30 GeV. The existence of this steady component was predicted as early as 1965 by Gould as inverse Compton scattering (ICS) over the whole Crab nebula, and the observed spectrum is consistent with the detailed ICS calculation o...

Published
1994

94. EGRET observations of Mrk 421 in Phase 1 and Phase 2 of the Compton Observatory’s viewing program—A summary

Author

C. E. Fichtel, H. A. Mayer-Hasselwander, Gottfried Kanbach, C. von Montigny, J. R. Mattox, D. A. Kniffen, Peter F. Michelson, R. C. Hartman, Brenda Dingus, J. A. Esposito, D. J. Thompson, James Chiang, Stanley D. Hunter, P. Sreekumar, E. J. Schneid, Y. C. Lin, P. L. Nolan, and D. L. Bertsch

Subjects
Physics, Spectral index, Photon, biology, Astronomy, Flux, Astrophysics, biology.organism_classification, law.invention, Telescope, Radiation flux, Observatory, law, Egret, BL Lac object
Abstract

During Phase 1 and Phase 2 of the Compton Observatory’s viewing program, Mrk 421 was in EGRET’s field of view a total of 6 times. This BL Lac object was positively detected by EGRET at 5 σ level and with a photon flux of (1.4±0.3)×10−7 cm−2 s−1 for E≳100 MeV when it was first covered by EGRET in 1991 June 28–July 12. The photon spectrum of this first observation can be represented by a single power law with a photon spectral index of −1.96±0.14. During the 5 subsequent observations, this source was covered by EGRET either at large viewing angles with respect to the instrument axis or with short exposure times. But the source was always visible to the EGRET telescope at about the same flux level as during the first observation except one viewing period, VP222, 1993 May 24–31, for which only an upper limit can be obtained for the photon flux. This upper limit is also consistent with the detected flux levels of the other observations. The average photon floux for E≳100 MeV as calculated from the combined data of all these 6 observations is (1.7±0.3)×10−7 cm−2 s−1 and the corresponding photon spectral index for the combined data is −1.71±0.15. A summary of these results are given in this paper.

Published
1994

95. ERRATUM: 'THE FIRST FERMI LARGE AREA TELESCOPE CATALOG OF GAMMA-RAY PULSARS' (2010, ApJS, 187, 460)

Author

Na Wang, James Chiang, Roger Blandford, B. Lott, Cristobal M. Espinoza, Jun Kataoka, Ö. Çelik, V. M. Kaspi, A. S. Johnson, S. Cutini, F. Piron, Jean Ballet, Gudlaugur Johannesson, Sinéad McGlynn, I. A. Grenier, M. Hayashida, M. Roth, A. De Luca, C. Favuzzi, Stefano Ciprini, Felix Ryde, Lucas Guillemot, B. Giebels, A. Tramacere, A. Noutsos, Stefan Funk, Guido Barbiellini, H. Tajima, Nicola Omodei, S. Murgia, V. Vasileiou, Richard Dubois, Luca Baldini, T. Mizuno, M. Marelli, M. Frailis, P. Spinelli, Scott M. Ransom, Seth Digel, M. S. Jackson, F. de Palma, Matthew G. Baring, Alice K. Harding, Fernando Camilo, Benjamin Stappers, C. Farnier, Elliott D. Bloom, B. M. Baughman, L. Tibaldo, L. R. Cominsky, Igor V. Moskalenko, T. A. Porter, Jürgen Knödlseder, Brian L Winer, Sylvain Guiriec, Gloria Spandre, S. Rainò, Eric V. Gotthelf, S. Germani, Mn Mazziotta, Olaf Reimer, A. A. Moiseev, Christo Venter, A. van Etten, Francesco Longo, P. Fusco, W. B. Atwood, Diego F. Torres, Omar Tibolla, Paul J. Wang, Andrew W. Strong, Denise A. Smith, A. Sellerholm, Roger W. Romani, Grzegorz Madejski, Nicola Giglietto, Hartmut Sadrozinski, Robert R. Rando, M. Kramer, David Sánchez, Dario Gasparrini, F. Gargano, Ronaldo Bellazzini, Gilles Theureau, Hideaki Katagiri, Luca Latronico, A. Sander, C. Meurer, T. J. Johnson, Y. Hanabata, M. N. Lovellette, F. Loparco, Paolo Giommi, Carmelo Sgrò, Denis Bastieri, P. D. Smith, Persis S. Drell, Alessandro Brez, E. Do Couto E Silva, Aous A. Abdo, T. L. Schalk, E. Nuss, W. N. Johnson, G. A. Caliandro, Paul S. Ray, C. Gwon, Elizabeth C. Ferrara, Gottfried Kanbach, David Paneque, M. Kuss, A. Y. Rodriguez, Randall P. Johnson, P. Weltevrede, Robin H. D. Corbet, D. Parent, J. E. Grove, Yasushi Fukazawa, P. Caraveo, Karen Watters, E. Hays, Jan Conrad, Pascal Bruel, Ismaël Cognard, Y. Uchiyama, Johann Cohen-Tanugi, P. M. Saz Parkinson, M. Dormody, Nanda Rea, Melissa Pesce-Rollins, M. S. Strickman, Andrew Lyne, A. P. Waite, T. Kamae, Peter F. Michelson, Richard N. Manchester, M. Lemoine-Goumard, G.L. Godfrey, Charles D. Dermer, A. Makeev, K. S. Wood, J. G. Thayer, Matthew Kerr, Tadayuki Takahashi, W. Mitthumsiri, R. Claus, S. J. Fegan, M. E. Monzani, J. B. Thayer, P. R. den Hartog, Jean-Luc Starck, J. P. Norris, W. B. Focke, A. Morselli, V. Vitale, A. Chekhtman, J. Bregeon, A. Reimer, Keith Bechtol, Marco Ajello, S. Buson, J. Lande, M. Razzano, A. De Angelis, M. Brigida, T. L. Usher, M.-H. Grondin, R. E. Hughes, Stephen E. Thorsett, E. Charles, M. Ozaki, J. F. Ormes, Emanuele Bonamente, D. J. Thompson, Francesco Giordano, Hiromitsu Takahashi, D. Dumora, P. L. Nolan, N. Gehrels, Takaaki Tanaka, T. Mineo, Claudia Cecchi, T. Glanzman, E. Orlando, V. Pelassa, T. Ylinen, R. A. Cameron, Julie McEnery, Steven Ritz, D. J. Suson, T. H. Burnett, B. Berenji, Gianluca Giavitto, M. Ziegler, Takeshi Nakamori, J. M. Casandjian, E. J. Siskind, T. Ohsugi, C. C. Cheung, Magnus Axelsson, Paulo C. C. Freire, W. Mcconville, N. Vilchez, E. Striani, P. Fortin, G. Tosti, Markus Ackermann, P. Lubrano, Simon Johnston, M. Pepe, Margaret A. Livingstone, Jeffrey D. Scargle, N. Kawai, M. L. Kocian, C. Monte, T. Reposeur, A. W. Borgland, and J. H. Panetta

Subjects
Physics, 010308 nuclear & particles physics, Gamma ray, Astronomy, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, law.invention, Telescope, Pulsar, Space and Planetary Science, law, 0103 physical sciences, 010303 astronomy & astrophysics, Fermi Gamma-ray Space Telescope
Published
2011

96. Preliminary EGRET soruce catalog

Author

H. Rothermel, C. E. Fichtel, Brenda Dingus, J. R. Mattox, D. A. Kniffen, P. F. Michelson, C. von Montigny, P. W. Kwok, M. Sommer, K. Pinkau, R. C. Hartman, D. J. Thompson, Gottfried Kanbach, Stanley D. Hunter, P. Sreekumar, E. J. Schneid, H. A. Mayer-Hasselwander, P. L. Nolan, D. L. Bertsch, and Y. C. Lin

Subjects
Physics, Solar flare, biology, Pulsar, Astronomy, Egret, Astrophysics, biology.organism_classification, Galaxy
Published
1993

97. EGRET observations of gamma-ray bursts

Author

C. E. Fichtel, E. J. Schneid, P. L. Nolan, K. Pinkau, D. L. Bertsch, R. C. Hartman, D. J. Thompson, Y. C. Lin, P. F. Michelson, Stanley D. Hunter, C. von Montigny, P. Sreekumar, H. Rothermel, P. W. Kwok, M. Sommer, J. R. Mattox, D. A. Kniffen, Gottfried Kanbach, H. A. Mayer-Hasselwander, and Brenda Dingus

Subjects
Physics, biology, Spectrometer, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Gamma ray, Astronomy, Astrophysics, biology.organism_classification, Light curve, law.invention, Telescope, Observatory, law, Egret, Spark chamber, Gamma-ray burst
Abstract

The EGRET instrument has detected gamma‐ray bursts in its large‐volume NaI spectrometer, anticoincidence shield and imaging spark chamber. Its spectral range from 1 MEV to greater than 200 MeV overlaps with and extends beyond those of other instruments on the Compton Gamma Ray Observatory. For intense high‐energy burst in the telescope field of view, detection of gamma rays in the spark chamber telescope allows the location of a burst to be determined. Only six bursts, three of which were strong bursts with gamma‐ray energies greater than 10 MeV, have been observed to date as a result of BATSE triggers. Interest in spectral breaks at lower energies led to a careful examination of the EGRET sensitivity in the overlap region with BATSE. The low‐energy sensitivity was studied using the detailed CGRO mass model; the resulting sensitivity values are presented as a function of burst direction relative to EGRET.

Published
1993

98. EGRET observation of the constellation Cygnus

Author

E. J. Schneid, Stanley D. Hunter, P. Sreekumar, P. W. Kowk, C. E. Fichtel, J. R. Mattox, H. D. Radecke, Gottfried Kanbach, James Chiang, T. Halaczek, K. Pinkau, Brenda Dingus, D. A. Kniffen, P. F. Michelson, H. Rothermal, C. von Montigny, H. A. Mayer-Hasselwander, J. M. Fierro, Y. C. Lin, P. L. Nolan, D. L. Bertsch, R. C. Hartman, D. J. Thompson, M. Sommer, and K. T. S. Brazier

Subjects
Physics, Spectral index, biology, Point source, media_common.quotation_subject, Astronomy, Flux, Astrophysics, biology.organism_classification, law.invention, Radiation flux, Observatory, law, Sky, Egret, Flare, media_common
Abstract

The Compton Observatory was pointed at Cygnus twice during the full sky survey (5/30–6/8/91 & 8/8–8/15/91). The COS‐B sources 2CG 075+00 and 2CG 078+01 are detected by EGRET, and smaller error boxes have been obtained, but the sources are not yet identified at other wavelengths. An excess of counts is noted at the position of Cygnus X‐3 consistent with a point source. The corresponding flux is 8±2×10−7 cm−2 s−1 (E≳0.1 GeV)—a factor of 5 less than the flux reported by the SAS‐2 group for Cygnus X‐3. The observed intensities for the individual periods were consistent with no change in intensity between the first and second observations (the second observation began two weeks after the beginning of the July 1991 radio flare). More work is required to refine and verify the galactic diffuse model (which comprises at least 10 times more flux than Cygnus X‐3 in this direction) before a definitive Cygnus X‐ray point‐source result will be obtained. The 4.8 hr X‐ray periodicity of Cygnus X‐3 is not detected in exta...

Published
1993

99. EGRET observations of gamma-ray bursts on June 1, 1991 and August 14, 1991

Author

H. A. Mayer-Hasselwander, M. Sommer, R. C. Hartman, D. J. Thompson, C. E. Fichtel, D. A. Kniffen, P. W. Kwok, K. Pinkau, H. Rothermel, Brenda Dingus, P. L. Nolan, P. F. Michelson, D. L. Bertsch, C. von Montigny, Y. C. Lin, J. R. Mattox, Stanley D. Hunter, P. Sreekumar, E. J. Schneid, and Gottfried Kanbach

Subjects
Physics, biology, Gamma ray, Bremsstrahlung, Astronomy, Astrophysics, biology.organism_classification, Spectral line, law.invention, Telescope, Atmosphere, law, Egret, Spark chamber, Gamma-ray burst
Abstract

The Energetic Gamma Ray Experimental Telescope (EGRET) instrument detected the gamma ray bursts on June 1, 1991 (GRB 910601) and August 14, 1991 (GRB 910814). Significant time structures down to 0.256 s were resolved by the by the anti‐coincidence dome. Spectra accumulated by the NaI(Tl) crystal are consistent with a power law model with evidence of spectral evolution. Four gamma ray events within 5 degrees from the direction of GRB 910601 were found in the spark chamber, when 1.5 could be expected from the detection rate, but they arrived only after the main burst emission had decayed. When GRB 910814 arrived, the spark chamber was disabled because the earth’s atmosphere was in its field of view.

Published
1993

100. EGRET observations of pulsars

Author

Matthew Bailes, H. I. Nel, Peter F. Michelson, Simon Johnston, D. A. Kniffen, K. T. S. Brazier, Y. C. Lin, H. A. Mayer-Hasselwander, C. von Montigny, J. R. Mattox, C. E. Fichtel, V. M. Kaspi, J. H. Taylor, Luciano Nicastro, David J. Nice, Gottfried Kanbach, James Chiang, P. L. Nolan, R. C. Hartman, Andrew Lyne, D. J. Thompson, D. L. Bertsch, N. D' Amico, Zaven Arzoumanian, R. N. Manchester, E. J. Schneid, Stanley D. Hunter, P. Sreekumar, K. Pinkau, and J. M. Fierro

Subjects
Physics, Millisecond, biology, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Gamma ray, Astronomy, Astrophysics, Vela, biology.organism_classification, Ephemeris, Pulsar, Observatory, Millisecond pulsar, Egret
Abstract

Ever since the detection of the Crab and Vela pulsars as high‐energy gamma‐ray sources, there has been speculation that many pulsars might be gamma‐ray emitters, some of which might be detectable with more sensitive instruments. Based on theoretical considerations, most interest has focused on young pulsars where a relatively high fraction of the spin down energy might be expected to be carried away in gamma rays. Millisecond pulsars have also been suggested as possible detectable gamma‐ray sources. Consequently, the Compton Gamma Ray Observatory was designed with the ability to time tag gamma rays to an accuracy of a tenth of a millisecond in absolute time. This is needed in view of the long integration times required because of the low expected fluxes. In addition, a cooperative effort has been organized with radio astronomers who are making contemporary measurements of the ephemerides of a relatively large fraction of known pulsars which might be expected to be candidate gamma‐ray ‘‘pulsars’’ based on ...

Published
1993

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