Author: "Rose, H. A." / Topic: astrophysics::high energy astrophysical phenomena - Searchworks@Jio Institute Digital Library Search Results

Your search keyword '"Rose, H. A."' showing total 62 results

Start Over Author "Rose, H. A." Topic astrophysics::high energy astrophysical phenomena

62 results on '"Rose, H. A."'

1. Multi-wavelength Observations of the Flaring Gamma-ray Blazar 3C 66A in 2008 October

Author: Abdo, A. A., Ackermann, M., Ajello, M., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bonamente, Emanuele, 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., Carrigan, S., Casandjian, J. M., Cavazzuti, E., Cecchi, Claudia, Çelik, Ö., Charles, E., Chekhtman, A., Cheung, C. C., Chiang, J., Ciprini, S., Claus, R., Cohen Tanugi, J., Conrad, J., Costamante, L., Cutini, S., Davis, D. S., Dermer, C. D., Palma, F. d., Digel, S. W., Couto, E. d., Drell, P. S., Dubois, R., Dumora, D., Favuzzi, C., Fegan, S. J., Fortin, P., Frailis, M., Fuhrmann, L., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grove, J. E., Guillemot, L., Guiriec, S., Hadasch, D., Hayashida, M., Hays, E., Horan, D., Hughes, R. E., Itoh, R., Jóhannesson, G., Johnson, A. S., Johnson, T. J., Johnson, W. N., Kamae, T., Katagiri, H., Kataoka, J., Knödlseder, J., Kuss, M., Lande, J., Latronico, L., Lee, S., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Makeev, A., Mazziotta, M. N., Mcenery, J. E., Mehault, J., Michelson, P. F., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Naumann Godo, M., Nestoras, I., Nolan, P. L., Norris, J. P., Nuss, E., 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., Piron, F., Porter, T. A., Rainò, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Reyes, L. C., Ripken, J., Ritz, S., Romani, R. W., Roth, M., Sadrozinski, H. F., Sanchez, D., Sander, A., Scargle, J. D., Sgrò, C., Shaw, M. S., Smith, P. D., Spandre, G., Spinelli, P., Strickman, M. S., Suson, D. J., Takahashi, H., Tanaka, T., Thayer, J. B., Thayer, J. G., Thompson, D. J., Tibaldo, L., Torres, D. F., Tosti, Gino, Tramacere, A., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vilchez, N., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Yang, Z., Ylinen, T., Ziegler, M., Acciari, V. A., Aliu, E., Arlen, T., Aune, T., Beilicke, M., Benbow, W., Böttcher, M., Boltuch, D., Bradbury, S. M., Buckley, J. H., Bugaev, V., Byrum, K., Cannon, A., Cesarini, A., Christiansen, J. L., Ciupik, L., Cui, W., I. d., La, Dickherber, R., Errando, M., Falcone, A., Finley, J. P., Finnegan, G., Fortson, L., Furniss, A., Galante, N., Gall, D., Gillanders, G. H., Godambe, S., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Holder, J., Hui, C. M., Humensky, T. B., Imran, A., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., Lebohec, S., Maier, G., Mcarthur, S., Mccann, A., Mccutcheon, M., Moriarty, P., Mukherjee, R., Ong, R. A., Otte, A. N., Pandel, D., Perkins, J. S., Pichel, A., Pohl, M., Quinn, J., Ragan, K., Reynolds, P. T., Roache, E., Rose, H. J., Schroedter, M., Sembroski, G. H., Senturk, G. D., Smith, A. W., Steele, D., Swordy, S. P., Tešić, G., Theiling, M., Thibadeau, S., Varlotta, A., Vassiliev, V. V., Vincent, S., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., Weisgarber, T., Williams, D. A., Wissel, S., Wood, M., Villata, M., Raiteri, C. M., Gurwell, M. A., Larionov, V. M., Kurtanidze, O. M., Aller, M. F., Lähteenmäki, A., Chen, W. P., Berduygin, A., Agudo, I., Aller, H. D., Arkharov, A. A., Bach, U., Bachev, R., Beltrame, P., Benítez, E., Buemi, C. S., Dashti, J., Calcidese, P., Capezzali, D., Carosati, D., Rio, D. D., Paola, A. D., Diltz, C., Dolci, M., Dultzin, D., Forné, E., Gómez, J. L., Hagen Thorn, V. A., Halkola, A., Heidt, J., Hiriart, D., Hovatta, T., Hsiao, H., Jorstad, S. G., Kimeridze, G. N., Konstantinova, T. S., Kopatskaya, E. N., Koptelova, E., Leto, P., Ligustri, R., Lindfors, E., Lopez, J. M., Marscher, A. P., Mommert, M., Mujica, R., Nikolashvili, M. G., Nilsson, K., Palma, N., Pasanen, M., Roca Sogorb, M., Ros, J. A., Roustazadeh, P., Sadun, A. C., Saino, J., Sigua, L. A., Sillanää, A., Sorcia, M., Takalo, L. O., Tornikoski, M., Trigilio, C., Turchetti, R., Umana, G., Belloni, T., Blake, C. H., Bloom, J. S., Angelakis, E., Fumagalli, M., Hauser, M., Prochaska, J. X., Riquelme, D., Sievers, A., Starr, D. L., Tagliaferri, G., Ungerechts, H., Wagner, S., Zensus, J. A., Collaboration, F. L., Collaboration, V., Consortium, G., 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), Laboratoire Leprince-Ringuet (LLR), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), 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-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), 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, Fermi-LAT, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), 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), Abdo, A. A., Ackermann, M., Ajello, M., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. 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., Carrigan, S., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Çelik, Ö., Charles, E., Chekhtman, A., Cheung, C. C., Chiang, J., Ciprini, S., Claus, R., Cohen Tanugi, J., Conrad, J., Costamante, L., Cutini, S., Davis, D. S., Dermer, C. D., de Palma, F., Digel, S. W., do Couto, e. Silva E., Drell, P. S., Dubois, R., Dumora, D., Favuzzi, C., Fegan, S. J., Fortin, P., Frailis, M., Fuhrmann, L., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grove, J. E., Guillemot, L., Guiriec, S., Hadasch, D., Hayashida, M., Hays, E., Horan, D., Hughes, R. E., Itoh, R., Jóhannesson, G., Johnson, A. S., Johnson, T. J., Johnson, W. N., Kamae, T., Katagiri, H., Kataoka, J., Knödlseder, J., Kuss, M., Lande, J., Latronico, L., Lee, S. H., Longo, Francesco, Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Makeev, A., Mazziotta, M. N., Mcenery, J. E., Mehault, J., Michelson, P. F., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Naumann Godo, M., Nestoras, I., Nolan, P. L., Norris, J. P., Nuss, E., 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., Piron, F., Porter, T. A., Rainò, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Reyes, L. C., Ripken, J., Ritz, S., Romani, R. W., Roth, M., Sadrozinski, H. F. W., Sanchez, D., Sander, A., Scargle, J. D., Sgrò, C., Shaw, M. S., Smith, P. D., Spandre, G., Spinelli, P., Strickman, M. S., Suson, D. J., Takahashi, H., Tanaka, T., Thayer, J. B., Thayer, J. G., Thompson, D. J., Tibaldo, L., Torres, D. F., Tosti, G., Tramacere, A., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vilchez, N., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Yang, Z., Ylinen, T., Ziegler, M., Acciari, V. A., Aliu, E., Arlen, T., Aune, T., Beilicke, M., Benbow, W., Böttcher, M., Boltuch, D., Bradbury, S. M., Buckley, J. H., Bugaev, V., Byrum, K., Cannon, A., Cesarini, A., Christiansen, J. L., Ciupik, L., Cui, W., de la Calle Perez, I., Dickherber, R., Errando, M., Falcone, A., Finley, J. P., Finnegan, G., Fortson, L., Furniss, A., Galante, N., Gall, D., Gillanders, G. H., Godambe, S., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Holder, J., Hui, C. M., Humensky, T. B., Imran, A., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., Lebohec, S., Maier, G., Mcarthur, S., Mccann, A., Mccutcheon, M., Moriarty, P., Mukherjee, R., Ong, R. A., Otte, A. N., Pandel, D., Perkins, J. S., Pichel, A., Pohl, M., Quinn, J., Ragan, K., Reynolds, P. T., Roache, E., Rose, H. J., Schroedter, M., Sembroski, G. H., Senturk G., Demet, Smith, A. W., Steele, D., Swordy, S. P., Tešić, G., Theiling, M., Thibadeau, S., Varlotta, A., Vassiliev, V. V., Vincent, S., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., Weisgarber, T., Williams, D. A., Wissel, S., Wood, M., Villata, M., Raiteri, C. M., Gurwell, M. A., Larionov, V. M., Kurtanidze, O. M., Aller, M. F., Lähteenmäki, A., Chen, W. P., Berduygin, A., Agudo, I., Aller, H. D., Arkharov, A. A., Bach, U., Bachev, R., Beltrame, P., Benítez, E., Buemi, C. S., Dashti, J., Calcidese, P., Capezzali, D., Carosati, D., Da Rio, D., Di Paola, A., Diltz, C., Dolci, M., Dultzin, D., Forné, E., Gómez, J. L., Hagen Thorn, V. A., Halkola, A., Heidt, J., Hiriart, D., Hovatta, T., Hsiao, H. Y., Jorstad, S. G., Kimeridze, G. N., Konstantinova, T. S., Kopatskaya, E. N., Koptelova, E., Leto, P., Ligustri, R., Lindfors, E., Lopez, J. M., Marscher, A. P., Mommert, M., Mujica, R., Nikolashvili, M. G., Nilsson, K., Palma, N., Pasanen, M., Roca Sogorb, M., Ros, J. A., Roustazadeh, P., Sadun, A. C., Saino, J., Sigua, L. A., Sillanää, A., Sorcia, M., Takalo, L. O., Tornikoski, M., Trigilio, C., Turchetti, R., Umana, G., Belloni, T., Blake, C. H., Bloom, J. S., Angelakis, E., Fumagalli, M., Hauser, M., Prochaska, J. X., Riquelme, D., Sievers, A., Starr, D. L., Tagliaferri, G., Ungerechts, H., Wagner, S., Zensus, J. A., Abdo, A, Ackermann, M, Ajello, M, Baldini, L, Ballet, J, Barbiellini, G, Bastieri, D, Bechtol, K, Bellazzini, R, Berenji, B, Blandford, R, Bonamente, E, Borgland, A, Bouvier, A, Bregeon, J, Brez, A, Brigida, M, Bruel, P, Buehler, R, Buson, S, Caliandro, G, Cameron, R, Caraveo, P, Carrigan, S, Casandjian, J, Cavazzuti, E, Cecchi, C, Celik, O, Charles, E, Chekhtman, A, Cheung, C, Chiang, J, Ciprini, S, Claus, R, Cohen-Tanugi, J, Conrad, J, Costamante, L, Cutini, S, Davis, D, Dermer, C, De Palma, F, Digel, S, Do Couto E Silva, E, Drell, P, Dubois, R, Dumora, D, Favuzzi, C, Fegan, S, Fortin, P, Frailis, M, Fuhrmann, L, Fukazawa, Y, Funk, S, Fusco, P, Gargano, F, Gasparrini, D, Gehrels, N, Germani, S, Giglietto, N, Giommi, P, Giordano, F, Giroletti, M, Glanzman, T, Godfrey, G, Grenier, I, Grove, J, Guillemot, L, Guiriec, S, Hadasch, D, Hayashida, M, Hays, E, Horan, D, Hughes, R, Itoh, R, Johannesson, G, Johnson, A, Johnson, T, Johnson, W, Kamae, T, Katagiri, H, Kataoka, J, Knodlseder, J, Kuss, M, Lande, J, Latronico, L, Lee, S, Longo, F, Loparco, F, Lott, B, Lovellette, M, Lubrano, P, Makeev, A, Mazziotta, M, Mcenery, J, Mehault, J, Michelson, P, Mizuno, T, Moiseev, A, Monte, C, Monzani, M, Morselli, A, Moskalenko, I, Murgia, S, Nakamori, T, Naumann-Godo, M, Nestoras, I, Nolan, P, Norris, J, Nuss, E, Ohsugi, T, Okumura, A, Omodei, N, Orlando, E, Ormes, J, Ozaki, M, Paneque, D, Panetta, J, Parent, D, Pelassa, V, Pepe, M, Pesce-Rollins, M, Piron, F, Porter, T, Raino, S, Rando, R, Razzano, M, Reimer, A, Reimer, O, Reyes, L, Ripken, J, Ritz, S, Romani, R, Roth, M, Sadrozinski, H, Sanchez, D, Sander, A, Scargle, J, Sgro, C, Shaw, M, Smith, P, Spandre, G, Spinelli, P, Strickman, M, Suson, D, Takahashi, H, Tanaka, T, Thayer, J, Thompson, D, Tibaldo, L, Torres, D, Tosti, G, Tramacere, A, Usher, T, Vandenbroucke, J, Vasileiou, V, Vilchez, N, Vitale, V, Waite, A, Wang, P, Winer, B, Wood, K, Yang, Z, Ylinen, T, Ziegler, M, Acciari, V, Aliu, E, Arlen, T, Aune, T, Beilicke, M, Benbow, W, Bottcher, M, Boltuch, D, Bradbury, S, Buckley, J, Bugaev, V, Byrum, K, Cannon, A, Cesarini, A, Christiansen, J, Ciupik, L, Cui, W, De La Calle Perez, I, Dickherber, R, Errando, M, Falcone, A, Finley, J, Finnegan, G, Fortson, L, Furniss, A, Galante, N, Gall, D, Gillanders, G, Godambe, S, Grube, J, Guenette, R, Gyuk, G, Hanna, D, Holder, J, Hui, C, Humensky, T, Imran, A, Kaaret, P, Karlsson, N, Kertzman, M, Kieda, D, Konopelko, A, Krawczynski, H, Krennrich, F, Lang, M, Lebohec, S, Maier, G, Mcarthur, S, Mccann, A, Mccutcheon, M, Moriarty, P, Mukherjee, R, Ong, R, Otte, A, Pandel, D, Perkins, J, Pichel, A, Pohl, M, Quinn, J, Ragan, K, Reynolds, P, Roache, E, Rose, H, Schroedter, M, Sembroski, G, Senturk, G, Smith, A, Steele, D, Swordy, S, Tesic, G, Theiling, M, Thibadeau, S, Varlotta, A, Vassiliev, V, Vincent, S, Wakely, S, Ward, J, Weekes, T, Weinstein, A, Weisgarber, T, Williams, D, Wissel, S, Wood, M, Villata, M, Raiteri, C, Gurwell, M, Larionov, V, Kurtanidze, O, Aller, M, Lahteenmaki, A, Chen, W, Berduygin, A, Agudo, I, Aller, H, Arkharov, A, Bach, U, Bachev, R, Beltrame, P, Benitez, E, Buemi, C, Dashti, J, Calcidese, P, Capezzali, D, Carosati, D, Da Rio, D, Di Paola, A, Diltz, C, Dolci, M, Dultzin, D, Forne, E, Gomez, J, Hagen-Thorn, V, Halkola, A, Heidt, J, Hiriart, D, Hovatta, T, Hsiao, H, Jorstad, S, Kimeridze, G, Konstantinova, T, Kopatskaya, E, Koptelova, E, Leto, P, Ligustri, R, Lindfors, E, Lopez, J, Marscher, A, Mommert, M, Mujica, R, Nikolashvili, M, Nilsson, K, Palma, N, Pasanen, M, Roca-Sogorb, M, Ros, J, Roustazadeh, P, Sadun, A, Saino, J, Sigua, L, Sillanaa, A, Sorcia, M, Takalo, L, Tornikoski, M, Trigilio, C, Turchetti, R, Umana, G, Belloni, T, Blake, C, Bloom, J, Angelakis, E, Fumagalli, M, Hauser, M, Prochaska, J, Riquelme, D, Sievers, A, Starr, D, Tagliaferri, G, Ungerechts, H, Wagner, S, Zensus, J, 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), 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), 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), and 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)
Subjects: individual: 3C 66A [BL Lacertae objects], Ciencias Físicas, spectral energy-distribution, Astrophysics, BL Lacertae objects: individual (3C 66A), bright blazars, 01 natural sciences, law.invention, purl.org/becyt/ford/1 [https], bl lacertae objects, Astronomi, astrofysik och kosmologi, law, Astronomy, Astrophysics and Cosmology, 010303 astronomy & astrophysics, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), radio-sources, [SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], epoch vlbi survey, 95.45.+i, 96.60.qe,95.55.Ka, Gamma ray, veritas observations, large-area telescope, Wavelength, Gamma rays: galaxie, active [galaxies], galaxies [gamma rays], Spectral energy distribution, BL Lacertae objects: individual: 3C 66A, Astrophysics - High Energy Astrophysical Phenomena, CIENCIAS NATURALES Y EXACTAS, BL Lac object, individual (3C 66A) [BL Lacertae objects], [PHYS.ASTR.HE]Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Astrophysics::High Energy Astrophysical Phenomena, galaxies: active, FOS: Physical sciences, Telescope, 0103 physical sciences, gamma rays: galaxies, Blazar, tev blazars, 010308 nuclear & particles physics, Scattering, background-radiation, Astronomy and Astrophysics, purl.org/becyt/ford/1.3 [https], Astronomía, Space and Planetary Science, active galactic nuclei, ddc:520, Fermi Gamma-ray Space Telescope
Abstract: 著者人数：328名, Accepted: 2010-10-29, 資料番号: SA1002650000
Published: 2011
Full Text: View/download PDF

2. Spectral Energy Distribution of Markarian 501: Quiescent State Versus Extreme Outburst

Author: Acciari, V.-A., Aleksic, J., Antonelli, L. A., Antoranz, P., Arlen, T., Aune, T., Backes, M., Barrio, J. A., Bastieri, D., Becerra González, J., Bednarek, W., Schultz, C., Schweizer, T., Sembroski, G. H., Shayduk, M., Shore, S. N., Sierpowska-Bartosik, A., Sillanpää, A., Sitarek, J., Sobczynska, D., Boller, A., Konopelko, A., Spanier, F., Spiro, S., Stamerra, A., Steele, D., Steinke, B., Storz, J., Strah, N., Struebig, J. C., Suric, T., Swordy, S. P., Krähenbühl, T., Boltuch, D., Takalo, L., Tavecchio, F., Temnikov, P., Terzic, T., Tescaro, D., Teshima, M., Theiling, M., the MAGIC Collaboration, the VERITAS Collaboration, Kranich, D., Thibadeau, S., Bonnoli, G., Torres, D. F., Vankov, H., Varlotta, A., Vassiliev, V. V., Vincent, S., Wagner, R. M., Wakely, S. P., Ward, J. E., Krause, J., Weekes, T. C., Weinstein, A., Bordas, P., Weisgarber, T., Weitzel, Q., Williams, D. A., Wood, M., Zabalza, V., Zandanel, F., Zanin, R., Krawczynski, H., Zitzer, B., Borla Tridon, D., Bosch-Ramon, V., Bose, D., Böttcher, M., Bradbury, S.-M., Braun, I., Bretz, T., Buckley, J.-H., Bugaev, V., Krennrich, F., Camara, M., Cannon, A., Carmona, E., Carosi, A., Cesarini, A., Ciupik, L., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., La Barbera, A., Covino, S., Cui, W., Dazzi, F., De Angelis, A., De Cea del Pozo, E., Delgado Mendez, C., De Lotto, B., De Maria, M., De Sabata, F., Diago Ortega, A., Leonardo, E., Dickherber, R., Doert, M., Domínguez, A., Dominis Prester, D., Dorner, D., Doro, M., Duke, C., Elsaesser, D., Errando, M., Lindfors, E., Falcone, A., Ferenc, D., Finley, J . P., Finnegan, G., Fonseca, M. V., Font, L., Fortson, L., Furniss, A., Galante, N., Gall, D., Lombardi, S., García López, R. J., Garczarczyk, M., Gaug, M., Giavitto, G., Godambe, S., Godinovic, N., Grube, J., Guenette, R., Gyuk, G., Hadasch, D., Beilicke, M., Hanna, D., Hayashida, M., Herrero, A., Hildebrand, D., Höhne-Mönch, D., Holder, J., Hose, J., Hrupec, D., Huang, D., Hui, C. M., Longo, F., Humensky, T. B., Imran, A., Jogler, T., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D., Klepser, S., López, M., Lorenz, E., Madhavan, A. S., Maier, G., Majumdar, P., Makariev, M., Maneva, G., Mankuzhiyil, N., Mannheim, K., Benbow, W., Maraschi, L., Mariotti, M., Martínez, M., Mazin, D., McArthur, S., McCann, A., Meucci, M., Miranda, J. M., Mirzoyan, R., Miyamoto, H., Berdyugin, A., Moldón, J., Moralejo, A., Moriarty, P., Nieto, D., Nilsson, K., Ong, R. A., Orito, R., Otte, A. N., Oya, I., Pandel, D., Berger, K., Paneque, D., Paoletti, R., Paredes, J. M., Partini, S., Pasanen, M., Pauss, F., Pegna, R. G., Perez-Torres, M. A., Perkins, J. S., Persic, M., Bernardini, E., Peruzzo, L., Pichel, A., Pochon, J., Pohl, M., Prada, F., Prada Moroni, P. G., Prandini, E., Puchades, N., Puljak, I., Quinn, J., Biland, A., Ragan, K., Reichardt, I., Reinthal, R., Reyes, L. C., Reynolds, P. T., Rhode, W., Ribó, M., Rico, J., Rissi, M., Roache, E., Blanch, O., Rose, H. J., Rügamer, S., Saggion, A., Saito, K., Saito, T. Y., Salvati, M., Sánchez-Conde, M., Satalecka, K., Scalzotto, V., Scapin, V., Bock, R. K., Schroedter, M., Universitat de Barcelona, Acciari, V. A., Arlen, T., Aune, T., Beilicke, M., Benbow, W., Böttcher, M., Boltuch, D., Bradbury, S. M., Buckley, J. H., Bugaev, V., Cannon, A., Cesarini, A., Ciupik, L., Cui, W., Dickherber, R., Duke, C., Errando, M., Falcone, A., Finley, J. P., Finnegan, G., Fortson, L., Furniss, A., Galante, N., Gall, D., Godambe, S., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Holder, J., Huang, D., Hui, C. M., Humensky, T. B., Imran, A., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D., Konopelko, A., Krawczynski, H., Krennrich, F., Madhavan, A. S., Maier, G., Mcarthur, S., Mccann, A., Moriarty, P., Ong, R. A., Otte, A. N., Pandel, D., Perkins, J. S., Pichel, A., Pohl, M., Quinn, J., Ragan, K., Reyes, L. C., Reynolds, P. T., Roache, E., Rose, H. J., Schroedter, M., Sembroski, G. H., Steele, D., Swordy, S. P., Theiling, M., Thibadeau, S., Varlotta, A., Vassiliev, V. V., Vincent, S., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., Weisgarber, T., Williams, D. A., Wood, M., Zitzer, B., Aleksić, J., Antonelli, L. A., Antoranz, P., Backes, M., Barrio, J. A., Bastieri, D., Becerra González, J., Bednarek, W., Berdyugin, A., Berger, K., Bernardini, E., Biland, A., Blanch, O., Bock, R. K., Boller, A., Bonnoli, G., Bordas, P., Borla Tridon, D., Bosch Ramon, V., Bose, D., Braun, I., Bretz, T., Camara, M., Carmona, E., Carosi, A., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Dazzi, F., De Angelis, A., De Cea del Pozo, E., De Lotto, B., De Maria, M., De Sabata, F., Delgado Mendez, C., Diago Ortega, A., Doert, M., Domínguez, A., Dominis Prester, D., Dorner, D., Doro, M., Elsaesser, D., Ferenc, D., Fonseca, M. V., Font, L., García López, R. J., Garczarczyk, M., Gaug, M., Giavitto, G., Godinović, N., Hadasch, D., Herrero, A., Hildebrand, D., Höhne Mönch, D., Hose, J., Hrupec, D., Jogler, T., Klepser, S., Krähenbühl, T., Kranich, D., Krause, J., La Barbera, A., Leonardo, E., Lindfors, E., Lombardi, S., Longo, Francesco, López, M., Lorenz, E., Majumdar, P., Makariev, M., Maneva, G., Mankuzhiyil, N., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Mazin, D., Meucci, M., Miranda, J. M., Mirzoyan, R., Miyamoto, H., Moldón, J., Moralejo, A., Nieto, D., Nilsson, K., Orito, R., Oya, I., Paoletti, R., Paredes, J. M., Partini, S., Pasanen, M., Pauss, F., Pegna, R. G., Perez Torres, M. A., Persic, M., Peruzzo, L., Pochon, J., Prada, F., Prada Moroni, P. G., Prandini, E., Puchades, N., Puljak, I., Reichardt, I., Reinthal, R., Rhode, W., Ribó, M., Rico, J., Rissi, M., Rügamer, S., Saggion, A., Saito, K., Saito, T. Y., Salvati, M., Sánchez Conde, M., Satalecka, K., Scalzotto, V., Scapin, V., Schultz, C., Schweizer, T., Shayduk, M., Shore, S. N., Sierpowska Bartosik, A., Sillanpää, A., Sitarek, J., Sobczynska, D., Spanier, F., Spiro, S., Stamerra, A., Steinke, B., Storz, J., Strah, N., Struebig, J. C., Suric, T., Takalo, L., Tavecchio, F., Temnikov, P., Terzić, T., Tescaro, D., Teshima, M., Torres, D. F., Vankov, H., Wagner, R. M., Weitzel, Q., Zabalza, V., Zandanel, F., Zanin, R., Paneque, D., and Hayashida, M.
Subjects: Astrophysics, 01 natural sciences, 7. Clean energy, LARGE-AREA TELESCOPE, law.invention, Raigs gamma, Spitzer Space Telescope, law, GAMMA-RAY EMISSION, ACTIVE GALACTIC NUCLEI, MULTIWAVELENGTH OBSERVATIONS, X-RAY, RADIATION, BLAZAR, PERFORMANCE, EVOLUTION, ASTRONOMY, 010303 astronomy & astrophysics, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, non-thermal [radiation mechanisms], Synchrotron, galaxies [X-rays], BL Lacertae objects: individual (Markarian 501 = VER J1653+397) — galaxies: active — gamma rays: observations — radiation mechanisms: non-thermal — X-rays: galaxies, bl lacertae objects: individual (markarian 501=ver j1653+397), active [galaxies], Spectral energy distribution, Electrónica, Física nuclear, Raigs X, Electricidad, Astrophysics - High Energy Astrophysical Phenomena, Active galactic nucleus, gamma ray astronomy, IMAGING CHERENKOV DETECTOR, Astrophysics::High Energy Astrophysical Phenomena, galaxies: active, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Photon energy, gamma rays: galaxies, 0103 physical sciences, X-rays, galaxie [gamma rays], Blazar, Astrophysics::Galaxy Astrophysics, 010308 nuclear & particles physics, Gamma rays, Astronomy and Astrophysics, radiation mechanisms: non-thermal, BL Lacertae objects: individual: Markarian 501 {\amp}equals VER J1653+397, X-rays: galaxies, Space and Planetary Science, individual: Markarian 501 {\amp}equals VER J1653+397 [BL Lacertae objects], Galàxies actives, Active galaxies, ddc:520, Order of magnitude, Fermi Gamma-ray Space Telescope
Abstract: The very high energy (VHE; E > 100 GeV) blazar Markarian 501 has a well-studied history of extreme spectral variability and is an excellent laboratory for studying the physical processes within the jets of active galactic nuclei. However, there are few detailed multiwavelength studies of Markarian 501 during its quiescent state, due to its low luminosity. A short-term multiwavelength study of Markarian 501 was coordinated in March 2009, focusing around a multi-day observation with the Suzaku X-ray satellite and including {\gamma}-ray data from VERITAS, MAGIC, and the Fermi Gamma-ray Space Telescope with the goal of providing a well-sampled multiwavelength baseline measurement of Markarian 501 in the quiescent state. The results of these quiescent-state observations are compared to the historically extreme outburst of April 16, 1997, with the goal of examining variability of the spectral energy distribution between the two states. The derived broadband spectral energy distribution shows the characteristic double-peaked profile. We find that the X-ray peak shifts by over two orders of magnitude in photon energy between the two flux states while the VHE peak varies little. The limited shift in the VHE peak can be explained by the transition to the Klein-Nishina regime. Synchrotron self-Compton models are matched to the data and the implied Klein-Nishina effects are explored., Comment: Accepted for publication in ApJ, 25 pages, 6 figures, corresponding authors: Daniel Gall daniel-d-gall@uiowa.edu and Wei Cui cui@purdue.edu
Published: 2011
Full Text: View/download PDF

3. Discovery Of Very High Energy Gamma Rays From Pks 1424+240 And Multiwavelength Constraints On Its Redshift

Author: Acciari, V. A., Aliu, E., Arlen, T., Aune, T., Bautista, M., Beilicke, M., Benbow, W., Böttcher, M., Boltuch, D., Bradbury, S. M., Buckley, J. H., Bugaev, V., Byrum, K., Cannon, A., Cesarini, A., Chow, Y. C., Ciupik, L., Cogan, P., Cui, W., Duke, C., Falcone, A., Finley, J. P., Finnegan, G., Fortson, L., Furniss, A., Galante, N., Gall, D., Gillanders, G. H., Godambe, S., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Holder, J., Hui, C. M., Humensky, T. B., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., Lebohec, S., Maier, G., Mcarthur, S., Mccann, A., Mccutcheon, M., Millis, J., Moriarty, P., Nagai, T., Ong, R. A., Otte, A. N., Pandel, D., Perkins, J. S., Pichel, A., Pohl, M., Quinn, J., Ragan, K., Reyes, L. C., Reynolds, P. T., Roache, E., Rose, H. J., Schroedter, M., Sembroski, G. H., Demet Senturk, G., Smith, A. W., Steele, D., Swordy, S. P., Theiling, M., Thibadeau, S., Varlotta, A., Vassiliev, V. V., Vincent, S., Wagner, R. G., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., Weisgarber, T., Williams, D. A., Wissel, S., Wood, M., Zitzer, B., Abdo, A. A., Ackermann, M., Ajello, M., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Baughman, B. M., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Bregeon, J., Brez, A., Brigida, Monica, Bruel, P., Burnett, T. H., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Çelik, Ö., Chekhtman, A., Cheung, C. C., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., Cutini, S., Dermer, C. D., De Angelis, A., De Palma, F., Do Couto E Silva, E., Drell, P. S., Drlica-Wagner, A., Dubois, R., Dumora, D., Farnier, C., Favuzzi, C., Fegan, S. J., Focke, W. B., Fortin, P., Frailis, M., Fukazawa, Y., 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., Grove, J. E., Guillemot, L., Guiriec, S., Hanabata, Y., Hays, E., Hughes, R. E., Jackson, M. S., Jóhannesson, G., Johnson, A. S., Johnson, W. N., Kamae, T., Katagiri, H., Kataoka, J., Kawai, N., Kerr, M., Knödlseder, J., Kocian, M. L., Kuss, M., Lande, J., Latronico, L., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Makeev, A., Mazziotta, M. N., Mcenery, J. E., Meurer, C., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monte, Claudia, 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., Parent, D., Pelassa, V., Pepe, M., Pesce-Rollins, M., Piron, F., Porter, T. A., Rainò, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Reposeur, T., Rodriguez, A. Y., Roth, M., Ryde, F., Sadrozinski, H. F. -W., Sanchez, D., Sander, A., Saz Parkinson, P. M., Scargle, J. D., Sgrò, C., Shaw, M. S., Siskind, E. J., Smith, P. D., Spandre, G., Spinelli, Pietro, Strickman, M. S., Suson, D. J., Tajima, H., Takahashi, H., 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., Vasileiou, V., Vilchez, N., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Ylinen, T., Ziegler, M., Barber, S. D., Terndrup, D. M., 2010, 1088/2041-8205/708/2/L100, 10., Article, Scopus, 2-s2. 0-77949547554, Acciari, V. A., Aliu, E., Arlen, T., Aune, T., Bautista, M., Beilicke, M., Benbow, W., Bottcher, M., Boltuch, D., Bradbury, S. M., Buckley, J. H., Bugaev, V., Byrum, K., Cannon, A., Cesarini, A., Chow, Y. C., Ciupik, L., Cogan, P., Cui, W., Duke, C., Falcone, A., Finley, J. P., Finnegan, G., Fortson, L., Furniss, A., Galante, N., Gall, D., Gillanders, G. H., Godambe, S., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Holder, J., Hui, C. M., Humensky, T. B., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., Lebohec, S., Maier, G., Mcarthur, S., Mccann, A., Mccutcheon, M., Millis, J., Moriarty, P., Nagai, T., Ong, R. A., Otte, A. N., Pandel, D., Perkins, J. S., Pichel, A., Pohl, M., Quinn, J., Ragan, K., Reyes, L. C., Reynolds, P. T., Roache, E., Rose, H. J., Schroedter, M., Sembroski, G. H., Senturk, G. D., Smith, A. W., Steele, D., Swordy, S. P., Theiling, M., Thibadeau, S., Varlotta, A., Vassiliev, V. V., Vincent, S., Wagner, R. G., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., Weisgarber, T., Williams, D. A., Wissel, S., Wood, M., Zitzer, B., Abdo, A. A., Ackermann, M., Ajello, M., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Baughman, B. M., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Bregeon, J., Brez, A., Brigida, M., Bruel, P., Burnett, T. H., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Celik, O., Chekhtman, A., Cheung, C. C., Chiang, J., Ciprini, S., Claus, R., Cohen Tanugi, J., Conrad, J., Cutini, S., Dermer, C. D., Angelis, A. d., Palma, F. d., Silva, E. D. E., Drell, P. S., Drlica Wagner, A., Dubois, R., Dumora, D., Farnier, C., Favuzzi, C., Fegan, S. J., Focke, W. B., Fortin, P., Frailis, M., Fukazawa, Y., 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., Grove, J. E., Guillemot, L., Guiriec, S., Hanabata, Y., Hays, E., Hughes, R. E., Jackson, M. S., Johannesson, G., Johnson, A. S., Johnson, W. N., Kamae, T., Katagiri, H., Kataoka, J., Kawai, N., Kerr, M., Knodlseder, J., Kocian, M. L., Kuss, M., Lande, J., Latronico, L., Longo, Francesco, Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Makeev, A., Mazziotta, M. N., Mcenery, J. E., 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., 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., Rodriguez, A. Y., Roth, M., Ryde, F., Sadrozinski, H. F. W., Sanchez, D., Sander, A., Parkinson, P. M. S., Scargle, J. D., Sgro, C., Shaw, M. S., Siskind, E. J., Smith, P. D., Spandre, G., Spinelli, P., Strickman, M. S., Suson, D. J., Tajima, H., Takahashi, H., 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., Vasileiou, V., Vilchez, N., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Ylinen, T., Ziegler, M., Barber, S. D., Terndrup, D. M., 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), Laboratoire Leprince-Ringuet (LLR), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), 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-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), 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, Fermi-LAT, 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), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), 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), 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), 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: [PHYS.ASTR.HE]Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Cosmology and Nongalactic Astrophysics (astro-ph.CO), spectra, Astrophysics::High Energy Astrophysical Phenomena, bl-lacertae objects, blazars, Flux, FOS: Physical sciences, Fermi satellite, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 7. Clean energy, 01 natural sciences, High Energy Gamma-ray Astronomy, bl lacertae objects: individual (pks 1424+240=ver j1427+237), gamma rays: observations, BL Lacertae objects: individual (PKS 1424+240 = VER J1427+237), gamma rays: observations, Observatory, veritas, emission, 0103 physical sciences, 010303 astronomy & astrophysics, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), 010308 nuclear & particles physics, [SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Gamma ray, background-radiation, Astronomy and Astrophysics, Active Galactic Nuclei, Redshift, astronomy, large-area telescope, mission, Extragalactic background light, 13. Climate action, Space and Planetary Science, Very High Energy Gamma-ray Astronomy, source list, ddc:520, Spectral energy distribution, High Energy Physics::Experiment, Astrophysics - High Energy Astrophysical Phenomena, BL Lac object, Fermi Gamma-ray Space Telescope, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: We report the first detection of very-high-energy (VHE) gamma-ray emission above 140 GeV from PKS 1424+240, a BL Lac object with an unknown redshift. The photon spectrum above 140 GeV measured by VERITAS is well described by a power law with a photon index of 3.8 +- 0.5_stat +- 0.3_syst and a flux normalization at 200 GeV of (5.1 +- 0.9_stat +- 0.5_syst) x 10^{-11} TeV^-1 cm^-2 s^-1, where stat and syst denote the statistical and systematical uncertainty, respectively. The VHE flux is steady over the observation period between MJD 54881 and 55003 (2009 February 19 to June 21). Flux variability is also not observed in contemporaneous high energy observations with the Fermi Large Area Telescope (LAT). Contemporaneous X-ray and optical data were also obtained from the Swift XRT and MDM observatory, respectively. The broadband spectral energy distribution (SED) is well described by a one-zone synchrotron self-Compton (SSC) model favoring a redshift of less than 0.1. Using the photon index measured with Fermi in combination with recent extragalactic background light (EBL) absorption models it can be concluded from the VERITAS data that the redshift of PKS 1424+240 is less than 0.66., Comment: accepted for publication, ApJ
Published: 2010
Full Text: View/download PDF

4. Multiwavelength Observations of Markarian 421 During a TeV/X-Ray Flare

Author: Macomb, D. J., Akerlof, C. W., Aller, H. D., Aller, M. F., Bertsch, D. L., Bruhweiler, F., Buckley, J. H., Carter-Lewis, D. A., Cawley, M. F., Cheng, K. -P., Dermer, C., Fegan, D. J., Gaidos, J. A., Gear, W. K., Hall, C. R., Hartman, R. C., Hillas, A. M., Kafatos, M., Kerrick, A. D., Kniffen, D. A., Kondo, Y., Lamb, R. C., Marscher, A., McEnery, J., McHardy, I. M., Meyer, D. I., Moore, E. M., Ramos, E., Robson, E. I., Rose, H. J., Schubnell, M. S., Sembroski, G., Stevens, J. A., Weekes, T. C., Wilson, C., Zweerink, J., Kubo, H., Makino, Fumiyoshi, Makishima, K., Takahashi, Tadayuki, and Tashiro, M.
Subjects: Physics, Active galactic nucleus, Radio galaxy, Astrophysics::High Energy Astrophysical Phenomena, Astronomy, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Gamma-ray astronomy, Astrophysics, law.invention, Space and Planetary Science, Observatory, law, Blazar, Markarian galaxies, Flare, BL Lac object
Abstract: 著者人数：41名, Accepted: 1995-06-09, 資料番号: SA1002227000
Published: 1995

5. Gamma-ray observations of the Be/pulsar binary 1A 0535+262 during a giant X-ray outburst

Author: VERITAS collaboration, Acciari, V. A., Aliu, E., Araya, M., Arlen, T., Aune, T., Beilicke, M., Benbow, W., Bradbury, S. M., Buckley, J. H., Bugaev, V., Byrum, K., Cannon, A., Cesarini, A., Ciupik, L., Collins-Hughes, E., Cui, W., Dickherber, R., Duke, C., Falcone, A., Finley, J. P., Fortson, L., Furniss, A., Galante, N., Gall, D., Godambe, S., Griffin, S., Guenette, R., Gyuk, G., Hanna, D., Holder, J., Hughes, G., Hui, C. M., Humensky, T. B., Imran, A., Kaaret, P., Kertzman, M., Krawczynski, H., Krennrich, F., Madhavan, A. S., Maier, G., Majumdar, P., McArthur, S., Moriarty, P., Ong, R. A., Otte, A. N., Pandel, D., Park, N., Perkins, J. S., Pohl, M., Prokoph, H., Quinn, J., Ragan, K., Reyes, L. C., Reynolds, P. T., Roache, E., Rose, H. J., Saxon, D. B., Sembroski, G. H., Senturk, G. Demet, Smith, A. W., Tešić, G., Theiling, M., Thibadeau, S., Varlotta, A., Vincent, S., Vivier, M., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., Weisgarber, T., Weng, S., Williams, D. A., Wood, M., and Zitzer, B.
Subjects: catalog, Astrophysics::High Energy Astrophysical Phenomena, Population, proportional counter array, FOS: Physical sciences, Binary number, a0535+262, Astrophysics, Electron, hess j0632+057, 01 natural sciences, Pulsar, 0103 physical sciences, emission, Black-body radiation, education, 010303 astronomy & astrophysics, acceleration of particles, pulsar, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, education.field_of_study, 010308 nuclear & particles physics, Gamma ray, stars: individual (1a 0535+262), Institut für Physik und Astronomie, Astronomy and Astrophysics, gamma rays: general, a-0535+26, calibration, period, Orbit, large-area telescope, binaries: general, Space and Planetary Science, Astrophysics - High Energy Astrophysical Phenomena, Fermi Gamma-ray Space Telescope
Abstract: Giant X-ray outbursts, with luminosities of about $ 10^{37}$ erg s$^{-1}$, are observed roughly every 5 years from the nearby Be/pulsar binary 1A 0535+262. In this article, we present observations of the source with VERITAS at very-high energies (VHE; E$>$100 GeV) triggered by the X-ray outburst in December 2009. The observations started shortly after the onset of the outburst, and they provided comprehensive coverage of the episode, as well as the 111-day binary orbit. No VHE emission is evident at any time. We also examined data from the contemporaneous observations of 1A 0535+262 with the Fermi/LAT at high energy photons (HE; E$>$0.1 GeV) and failed to detect the source at GeV energies. The X-ray continua measured with the Swift/XRT and the RXTE/PCA can be well described by the combination of blackbody and Comptonized emission from thermal electrons. Therefore, the gamma-ray and X-ray observations suggest the absence of a significant population of non-thermal particles in the system. This distinguishes 1A~0535+262 from those Be X-ray binaries (such as PSR B1259--63 and LS I +61$^{\circ}$303) that have been detected at GeV--TeV energies. We discuss the implications of the results on theoretical models., 28 pages, 4 figures; accepted by The Astrophysical Journal updated references
Published: 2011
Full Text: View/download PDF

6. VERITAS OBSERVATIONS OF THE TeV BINARY LS I+61 degrees 303 DURING 2008-2010

Author: Acciari, V. A., Aliu, E., Arlen, T., Aune, T., Beilicke, M., Benbow, W., Bradbury, S. M., Buckley, J. H., Bugaev, V., Byrum, K., Cannon, A., Cesarini, A., Ciupik, L., Collins-Hughes, E., Connolly, M. P., Cui, W., Dickherber, R., Duke, C., Errando, M., Falcone, A., Finley, J. P., Finnegan, G., Fortson, L., Furniss, A., Galante, N., Gall, D., Gillanders, G. H., Godambe, S., Griffin, S., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Holder, J., Hughes, G., Hui, C. M., Humensky, T. B., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D., Krawczynski, H., Krennrich, F., Lang, M. J., LeBohec, S., Maier, G., Majumdar, P., McArthur, S., McCann, A., Moriarty, P., Mukherjee, R., Ong, R. A., Orr, M., Otte, A. N., Park, N., Perkins, J. S., Pohl, Martin Karl Wilhelm, Prokoph, H., Quinn, J., Ragan, K., Reyes, L. C., Reynolds, P. T., Roache, E., Rose, H. J., Ruppel, J., Saxon, D. B., Schroedter, M., Sembroski, G. H., Senturk, G. D., Smith, A. W., Staszak, D., Tesic, G., Theiling, M., Thibadeau, S., Tsurusaki, K., Varlotta, A., Vassiliev, V. V., Vincent, S., Vivier, M., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., Weisgarber, T., Williams, D. A., and Zitzer, B.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Institut für Physik und Astronomie
Abstract: We present the results of observations of the TeV binary LS I + 61 degrees 303 with the VERITAS telescope array between 2008 and 2010, at energies above 300 GeV. In the past, both ground-based gamma-ray telescopes VERITAS and MAGIC have reported detections of TeV emission near the apastron phases of the binary orbit. The observations presented here show no strong evidence for TeV emission during these orbital phases; however, during observations taken in late 2010, significant emission was detected from the source close to the phase of superior conjunction (much closer to periastron passage) at a 5.6 standard deviation (5.6 sigma) post-trials significance. In total, between 2008 October and 2010 December a total exposure of 64.5 hr was accumulated with VERITAS on LS I + 61 degrees 303, resulting in an excess at the 3.3 sigma significance level for constant emission over the entire integrated data set. The flux upper limits derived for emission during the previously reliably active TeV phases (i.e., close to apastron) are less than 5% of the Crab Nebula flux in the same energy range. This result stands in apparent contrast to previous observations by both MAGIC and VERITAS which detected the source during these phases at 10% of the Crab Nebula flux. During the two year span of observations, a large amount of X-ray data were also accrued on LS I + 61 degrees 303 by the Swift X-ray Telescope and the Rossi X-ray Timing Explorer Proportional Counter Array. We find no evidence for a correlation between emission in the X-ray and TeV regimes during 20 directly overlapping observations. We also comment on data obtained contemporaneously by the Fermi Large Area Telescope.
Published: 2011

7. Discovery of very high energy gamma-ray emission from the SNR G54.1+0.3

Author: Acciari, V. A., Aliu, E., Arlen, T., Aune, T., Bautista, M., Beilicke, M., Benbow, W., Boltuch, D., Bradbury, S. M., Buckley, J. H., Bugaev, V., Butt, Y., Byrum, K., Cesarini, A., Ciupik, L., Cui, W., Dickherber, R., Duke, C., Finley, J. P., Finnegan, G., Fortson, L., Furniss, A., Galante, N., Gall, D., Gillanders, G. H., Godambe, S., Gotthelf, E. V., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Holder, J., Hui, C. M., Humensky, T. B., Imran, A., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., LeBohec, S., Maier, G., McArthur, S., McCann, A., McCutcheon, M., Moriarty, P., Muhkerjee, R., Ong, R. A., Otte, A. N., Pandel, D., Perkins, J. S., Pohl, M., Quinn, J., Ragan, K., Reyes, L. C., Reynolds, P. T., Roache, E., Rose, H. J., Schroedter, M., Sembroski, G. H., Senturk, G. D., Slane, P., Smith, A. W., Steele, D., Swordy, S. P., Tesic, G., Theiling, M., Thibadeau, S., Vassiliev, V. V., Vincent, S., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., Weisgarber, T., Williams, D. A., Wissel, S., Wood, M., and Zitzer, B.
Subjects: Astrophysics::High Energy Astrophysical Phenomena
Abstract: We report the discovery of very high energy (VHE) gamma-ray emission from the direction of the SNR G54.1+ 0.3 using the VERITAS ground-based gamma-ray observatory. The TeV signal has an overall significance of 6.8s and appears pointlike given the resolution of the instrument. The integral flux above 1 TeV is 2.5% of the Crab Nebula flux and significant emission is measured between 250 GeV and 4 TeV, well described by a power-law energy spectrum dN/dE similar to E-Gamma with a photon index Gamma = 2.39 +/- 0.23(stat) +/- 0.30sys. We find no evidence of time variability among observations spanning almost two years. Based on the location, the morphology, the measured spectrum, the lack of variability, and a comparison with similar systems previously detected in the TeV band, the most likely counterpart of this new VHE gamma-ray source is the pulsar wind nebula (PWN) in the SNR G54.1+0.3. The measured X-ray to VHE gamma-ray luminosity ratio is the lowest among all the nebulae supposedly driven by young rotation-powered pulsars, which could indicate a particle-dominated PWN.
Published: 2010

8. VERITAS 2008 - 2009 monitoring of the variable gamma-ray source M87

Author: The VERITAS Collaboration, Acciari, V. A., Aliu, E., Arlen, T., Aune, T., Beilicke, M., Benbow, W., Boltuch, D., Bradbury, S. M., Buckley, J. H., Bugaev, V., Byrum, K., Cannon, A., Cesarini, A., Chow, Y. C., Ciupik, L., Cogan, P., Cui, W., Dickherber, R., Duke, C., Finley, J. P., Finnegan, G., Fortin, P., Fortson, L., Furniss, A., Galante, N., Gall, D., Gillanders, G. H., Godambe, S., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Holder, J., Hui, C. M., Humensky, T. B., Imran, A., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., LeBohec, S., Maier, G., McArthur, S., McCann, A., McCutcheon, M., Millis, J., Moriarty, P., Ong, R. A., Otte, A. N., Pandel, D., Perkins, J. S., Quinn, A. M. J., Ragan, K., Reyes, L. C., Reynolds, P. T., Roache, E., Rose, H. J., Rovero, A. C., Schroedter, M., Sembroski, G. H., Senturk, G. Demet, Smith, A. W., Steele, D., Swordy, S. P., Theiling, M., Thibadeau, S., Varlotta, A., Vincent, S., Wagner, R. G., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., Weisgarber, T., Williams, D. A., Wissel, S., Wood, M., Zitzer, B., Monitoring, Chandra M87, Harris, D. E., and Massaro, F.
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO), black-hole, Radio galaxy, Astrophysics::High Energy Astrophysical Phenomena, Ciencias Físicas, FOS: Physical sciences, Flux, radio galaxy m87, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, VER J1230+123), telescope, 01 natural sciences, law.invention, purl.org/becyt/ford/1 [https], Observatory, law, jet, gamma rays: galaxies, 0103 physical sciences, site, Astrophysics::Solar and Stellar Astrophysics, hst-1, Spectral analysis, 010303 astronomy & astrophysics, galaxies: individual (M87, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, tev emission, variability, 010308 nuclear & particles physics, Gamma ray, galaxies: individual (m87, ver j1230+123), Astronomy and Astrophysics, individual: M87 VER J1230+123 [galaxies], purl.org/becyt/ford/1.3 [https], m-87, astronomy, Astronomía, galaxies: individual (M87, VER J1230+123) , gamma rays: galaxies, Crab Nebula, 13. Climate action, Space and Planetary Science, galaxies [gamma rays], Astrophysics - High Energy Astrophysical Phenomena, CIENCIAS NATURALES Y EXACTAS, Astrophysics - Cosmology and Nongalactic Astrophysics, Flare
Abstract: M87 is a nearby radio galaxy that is detected at energies ranging from radio to VHE gamma-rays. Its proximity and its jet, misaligned from our line-of-sight, enable detailed morphological studies and extensive modeling at radio, optical, and X-ray energies. Flaring activity was observed at all energies, and multi-wavelength correlations would help clarify the origin of the VHE emission. In this paper, we describe a detailed temporal and spectral analysis of the VERITAS VHE gamma-ray observations of M87 in 2008 and 2009. In the 2008 observing season, VERITAS detected an excess with a statistical significance of 7.2 sigma from M87 during a joint multi-wavelength monitoring campaign conducted by three major VHE experiments along with the Chandra X-ray Observatory. In February 2008, VERITAS observed a VHE flare from M87 occurring over a 4-day timespan. The peak nightly flux above 250GeV was 7.7% of the Crab Nebula flux. M87 was marginally detected before this 4-day flare period, and was not detected afterwards. Spectral analysis of the VERITAS observations showed no significant change in the photon index between the flare and pre-flare states. Shortly after the VHE flare seen by VERITAS, the Chandra X-ray Observatory detected the flux from the core of M87 at a historical maximum, while the flux from the nearby knot HST-1 remained quiescent. Acciari et al. (2009) presented the 2008 contemporaneous VHE gamma-ray, Chandra X-ray, and VLBA radio observations which suggest the core as the most likely source of VHE emission, in contrast to the 2005 VHE flare that was simultaneous with an X-ray flare in the HST-1 knot. In 2009, VERITAS continued its monitoring of M87 and marginally detected a 4.2 sigma excess corresponding to a flux of ~1% of the Crab Nebula. No VHE flaring activity was observed in 2009., Comment: 17 pages, 5 figures, accepted for publication in ApJ
Published: 2010
Full Text: View/download PDF

9. Veritas 2008-2009 monitoring of the variable gamma-ray source M 87

Author: Acciari, V. A., Aliu, E., Arlen, T., Aune, T., Beilicke, M., Benbow, W., Boltuch, D., Bradbury, S. M., Buckley, J. H., Bugaev, V., Byrum, K., Cannon, A., Cesarini, A., Chow, Y. C., Ciupik, L., Cogan, P., Cui, W., Dickherber, R., Duke, C., Finley, J. P., Finnegan, G., Fortin, P., Fortson, L., Furniss, A., Galante, N., Gall, D., Gillanders, G. H., Godambe, S., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Holder, J., Hui, C. M., Humensky, T. B., Imran, A., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., LeBohec, S., Maier, G., McArthur, S., McCann, A., McCutcheon, M., Millis, J., Moriarty, P., Ong, R. A., Otte, A. N., Pandel, D., Perkins, J. S., Pichel, A., Pohl, M., Quinn, J., Ragan, K., Reyes, L. C., Reynolds, P. T., Roache, E., Rose, H. J., Rovero, A. C., Schroedter, M., Sembroski, G. H., Senturk, G. D., Smith, A. W., Steele, D., Swordy, S. P., Theiling, M., Thibadeau, S., Varlotta, A., Vincent, S., Wagner, R. G., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., Weisgarber, T., Williams, D. A., Wissel, S., Wood, M., Zitzer, B., Harris, D. E., and Massaro, F.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics
Abstract: M 87 is a nearby radio galaxy that is detected at energies ranging from radio to very high energy (VHE) gamma rays. Its proximity and its jet, misaligned from our line of sight, enable detailed morphological studies and extensive modeling at radio, optical, and X-ray energies. Flaring activity was observed at all energies, and multi-wavelength correlations would help clarify the origin of the VHE emission. In this paper, we describe a detailed temporal and spectral analysis of the VERITAS VHE gamma-ray observations of M 87 in 2008 and 2009. In the 2008 observing season, VERITAS detected an excess with a statistical significance of 7.2 standard deviations (sigma) from M 87 during a joint multi-wavelength monitoring campaign conducted by three major VHE experiments along with the Chandra X-ray Observatory. In 2008 February, VERITAS observed a VHE flare from M 87 occurring over a 4 day timespan. The peak nightly flux above 250 GeV was (1.14 +/- 0.26) x 10(-11) cm(-2) s(-1), which corresponded to 7.7% of the Crab Nebula flux. M 87 was marginally detected before this 4 day flare period, and was not detected afterward. Spectral analysis of the VERITAS observations showed no significant change in the photon index between the flare and pre-flare states. Shortly after the VHE flare seen by VERITAS, the Chandra X-ray Observatory detected the flux from the core of M 87 at a historical maximum, while the flux from the nearby knot HST-1 remained quiescent. Acciari et al. presented the 2008 contemporaneous VHE gamma-ray, Chandra X-ray, and Very Long Baseline Array radio observations which suggest the core as the most likely source of VHE emission, in contrast to the 2005 VHE flare that was simultaneous with an X-ray flare in the HST-1 knot. In 2009, VERITAS continued its monitoring of M 87 and marginally detected a 4.2 sigma excess corresponding to a flux of similar to 1% of the Crab Nebula. No VHE flaring activity was observed in 2009.
Published: 2010

10. Discovery of VHE $\gamma$-ray emission from the SNR G54.1+0.3

Author: Acciari, V. A., Aliu, E., Arlen, T., Aune, T., Bautista, M., Beilicke, M., Benbow, W., Boltuch, D., Bradbury, S. M., Buckley, J. H., Bugaev, V., Butt, Y., Byrum, K., Cesarini, A., Ciupik, L., Cui, W., Dickherber, R., Duke, C., Finley, J. P., Finnegan, G., Fortson, L., Furniss, A., Galante, N., Gall, D., Gillanders, G. H., Godambe, S., Gotthelf, E. V., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Holder, J., Hui, C. M., Humensky, T. B., Imran, A., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., LeBohec, S., Maier, G., McArthur, S., McCann, A., McCutcheon, M., Moriarty, P., Muhkerjee, R., Ong, R. A., Otte, A. N., Pandel, D., Perkins, J. S., Pohl, M., Quinn, J., Ragan, K., Reyes, L. C., Reynolds, P. T., Roache, E., Rose, H. J., Schroedter, M., Sembroski, G. H., Senturk, G. Demet, Slane, P., Smith, A. W., Steele, D., Swordy, S. P., Těsić, G., Theiling, M., Thibadeau, S., Vassiliev, V. V., Vincent, S., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., Weisgarber, T., Williams, D. A., Wissel, S., Wood, M., and Zitzer, B.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, High Energy Physics::Experiment, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics::Galaxy Astrophysics
Abstract: We report the discovery of very high energy gamma-ray emission from the direction of the SNR G54.1+0.3 using the VERITAS ground-based gamma-ray observatory. The TeV signal has an overall significance of 6.8$\sigma$ and appears point-like given the 5$^{arcminute}$ resolution of the instrument. The integral flux above 1 TeV is 2.5% of the Crab Nebula flux and significant emission is measured between 250 GeV and 4 TeV, well described by a power-law energy spectrum dN/dE $\sim$ E$^{-\Gamma}$ with a photon index $\Gamma= 2.39\pm0.23_{stat}\pm0.30_{sys}$. We find no evidence of time variability among observations spanning almost two years. Based on the location, the morphology, the measured spectrum, the lack of variability and a comparison with similar systems previously detected in the TeV band, the most likely counterpart of this new VHE gamma-ray source is the PWN in the SNR G54.1+0.3. The measured X-ray to VHE gamma-ray luminosity ratio is the lowest among all the nebulae supposedly driven by young rotation-powered pulsars, which could indicate a particle-dominated PWN., Comment: 5 pages, 2 figure, Latex, emulateapj style, accepted by the Astrophysical Journal Letters
Published: 2010

11. Observations of the shell-type SNR Cassiopeia A at TeV energies with VERITAS

Author: The VERITAS Collaboration, Acciari, V. A., Aliu, E., Arlen, T., Aune, T., Bautista, M., Beilicke, M., Benbow, W., Boltuch, D., Bradbury, S. M., Buckley, J. H., Bugaev, V., Butt, Y., Byrum, K., Cannon, A., Cesarini, A., Chow, Y. C., Ciupik, L., Cogan, P., Cui, W., Dickherber, R., Duke, C., Ergin, T., Fegan, S. J., Finley, J. P., Finnegan, G., Fortin, P., Fortson, L., Furniss, A., Galante, N., Gall, D., Gillanders, G. H., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Holder, J., Huang, D., Hui, C. M., Humensky, T. B., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., LeBohec, S., Maier, G., McArthur, S., McCann, A., McCutcheon, M., Millis, J., Moriarty, P., Ong, R. A., Pandel, D., Perkins, J. S., Pohl, M., Quinn, J., Ragan, K., Reynolds, P. T., Roache, E., Rose, H. J., Schroedter, M., Sembroski, G. H., Smith, A. W., Smith, B. R., Steele, D., Swordy, S. P., Theiling, M., Thibadeau, S., Varlotta, A., Vassiliev, V. V., Vincent, S., Wagner, R. G., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., Weisgarber, T., Wissel, S., and Wood, M.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Astrophysics of Galaxies (astro-ph.GA), Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies, Astrophysics::Galaxy Astrophysics
Abstract: We report on observations of very high-energy gamma rays from the shell-type supernova remnant Cassiopeia A with the VERITAS stereoscopic array of four imaging atmospheric Cherenkov telescopes in Arizona. The total exposure time for these observations is 22 hours, accumulated between September and November of 2007. The gamma-ray source associated with the SNR Cassiopeia A was detected above 200 GeV with a statistical significance of 8.3 s.d. The estimated integral flux for this gamma-ray source is about 3% of the Crab-Nebula flux. The photon spectrum is compatible with a power law dN/dE ~ E^(-Gamma) with an index Gamma = 2.61 +/- 0.24(stat) +/- 0.2(sys). The data are consistent with a point-like source. We provide a detailed description of the analysis results, and discuss physical mechanisms that may be responsible for the observed gamma-ray emission., 27 pages, 2 figures; Accepted for publication in ApJ
Published: 2010

12. Discovery of variability in the very high energy famma-ray emission of 1ES 1218+304 with veritas

Author: Acciari, V. A., Aliu, E., Beilicke, M., Benbow, W., Boltuch, D., Bottcher, M., Bradbury, S. M., Bugaev, V., Byrum, K., Cesarini, A., Ciupik, L., Cogan, P., Cui, W., Dickherber, R., Duke, C., Falcone, A., Finley, J. P., Finnegan, G., Fortson, L., Furniss, A., Galante, N., Gall, D., Gibbs, K., Guenette, R., Gillanders, G. H., Godambe, S., Grube, J., Hanna, D., Hui, C. M., Humensky, T. B., Imran, A., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D., Krawczynski, H., Krennrich, F., Lang, M. J., LeBohec, S., Maier, G., McArthur, S., McCann, A., Moriarty, P., Nagai, T., Ong, R. A., Otte, A. N., Pandel, D., Perkins, J. S., Pichel, A., Pohl, M., Quinn, J., Ragan, K., Reyes, L. C., Reynolds, P. T., Roache, E., Rose, H. J., Schroedter, M., Sembroski, G. H., Smith, A. W., Steele, D., Swordy, S. P., Theiling, M., Thibadeau, S., Vassiliev, V. V., Vincent, S., Wakely, S. P., Weekes, T. C., Weinstein, A., Weisgarber, T., and Williams, D. A.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Cosmology and Extragalactic Astrophysics
Abstract: We present results from an intensive VERITAS monitoring campaign of the high-frequency peaked BL Lac object 1ES 1218+304 in 2008/2009. Although 1ES 1218+304 was detected previously by MAGIC and VERITAS at a persistent level of similar to 6% of the Crab Nebula flux, the new VERITAS data reveal a prominent flare reaching similar to 20% of the Crab. While very high energy (VHE) flares are quite common in many nearby blazars, the case of 1ES 1218+304 (redshift z = 0.182) is particularly interesting since it belongs to a group of blazars that exhibit unusually hard VHE spectra considering their redshifts. When correcting the measured spectra for absorption by the extragalactic background light, 1ES 1218+304 and a number of other blazars are found to have differential photon indices Gamma
Published: 2010

13. Discovery of Variability in the Very High Energy Gamma-Ray Emission of 1ES 1218+304 with VERITAS

Author: The VERITAS Collaboration, Acciari, V. A., Aliu, E., Beilicke, M., Benbow, W., Boltuch, D., B��ttcher, M., Bradbury, S. M., Bugaev, V., Byrum, K., Cesarini, A., Ciupik, L., Cogan, P., Cui, W., Dickherber, R., Duke, C., Falcone, A., Finley, J. P., Finnegan, G., Fortson, L., Furniss, A., Galante, N., Gall, D., Gibbs, K., Guenette, R., Gillanders, G. H., Godambe, S., Grube, J., Hanna, D., Hui, C. M., Humensky, T. B., Imran, A., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D., Krawczynski, H., Krennrich, F., Lang, M. J., LeBohec, S., Maier, G., McArthur, S., McCann, A., Moriarty, P., Nagai, T., Ong, R. A., Otte, A. N., Pandel, D., Perkins, J. S., Pichel, A., Pohl, M., Quinn, J., Ragan, K., Reyes, L. C., Reynolds, P. T., Roache, E., Rose, H. J., Schroedter, M., Sembroski, G. H., Smith, A. W., Steele, D., Swordy, S. P., Theiling, M., Thibadeau, S., Vassiliev, V. V., Vincent, S., Wakely, S. P., Weekes, T. C., Weinstein, A., Weisgarber, T., and Williams, D. A.
Subjects: extragalactic background light, Cosmology and Nongalactic Astrophysics (astro-ph.CO), spectra, Astrophysics::High Energy Astrophysical Phenomena, galaxies: active, blazars, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, telescope, 01 natural sciences, bl lacertae objects: individual (1es 1218+304=ver j1221+301), law.invention, Astrophysical jet, law, jet, 0103 physical sciences, gamma rays: galaxies, Blazar, 010303 astronomy & astrophysics, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), 010308 nuclear & particles physics, Astronomy and Astrophysics, acceleration, Light curve, Redshift, w-comae, Crab Nebula, Extragalactic background light, 13. Climate action, Space and Planetary Science, active galactic nuclei, peaked bl-lacertae, ddc:520, Astrophysics - High Energy Astrophysical Phenomena, constraints, Astrophysics - Cosmology and Nongalactic Astrophysics, Flare, BL Lac object
Abstract: We present results from an intensive VERITAS monitoring campaign of the high-frequency peaked BL Lac object 1ES 1218+304 in 2008/2009. Although 1ES 1218+304 was detected previously by MAGIC and VERITAS at a persistent level of ~6% of the Crab Nebula flux, the new VERITAS data reveal a prominent flare reaching ~20% of the Crab. While very high energy (VHE) flares are quite common in many nearby blazars, the case of 1ES 1218+304 (redshift z = 0.182) is particularly interesting since it belongs to a group of blazars that exhibit unusually hard VHE spectra considering their redshifts. When correcting the measured spectra for absorption by the extragalactic background light, 1ES 1218+304 and a number of other blazars are found to have differential photon indices less than 1.5. The difficulty in modeling these hard spectral energy distributions in blazar jets has led to a range of theoretical gamma-ray emission scenarios, one of which is strongly constrained by these new VERITAS observations. We consider the implications of the observed light curve of 1ES 1218+304, which shows day scale flux variations, for shock acceleration scenarios in relativistic jets, and in particular for the viability of kiloparsec-scale jet emission scenarios., Comment: 5 pages, 3 figures; Published in The Astrophysical Journal Letters
Published: 2010
Full Text: View/download PDF

14. Discovery of VHE $��$-ray emission from the SNR G54.1+0.3

Author: Acciari, V. A., Aliu, E., Arlen, T., Aune, T., Bautista, M., Beilicke, M., Benbow, W., Boltuch, D., Bradbury, S. M., Buckley, J. H., Bugaev, V., Butt, Y., Byrum, K., Cesarini, A., Ciupik, L., Cui, W., Dickherber, R., Duke, C., Finley, J. P., Finnegan, G., Fortson, L., Furniss, A., Galante, N., Gall, D., Gillanders, G. H., Godambe, S., Gotthelf, E. V., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Holder, J., Hui, C. M., Humensky, T. B., Imran, A., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., LeBohec, S., Maier, G., McArthur, S., McCann, A., McCutcheon, M., Moriarty, P., Muhkerjee, R., Ong, R. A., Otte, A. N., Pandel, D., Perkins, J. S., Pohl, M., Quinn, J., Ragan, K., Reyes, L. C., Reynolds, P. T., Roache, E., Rose, H. J., Schroedter, M., Sembroski, G. H., Senturk, G. Demet, Slane, P., Smith, A. W., Steele, D., Swordy, S. P., T��si��, G., Theiling, M., Thibadeau, S., Vassiliev, V. V., Vincent, S., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., Weisgarber, T., Williams, D. A., Wissel, S., Wood, M., and Zitzer, B.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, High Energy Physics::Experiment, Astrophysics::Galaxy Astrophysics
Abstract: We report the discovery of very high energy gamma-ray emission from the direction of the SNR G54.1+0.3 using the VERITAS ground-based gamma-ray observatory. The TeV signal has an overall significance of 6.8$��$ and appears point-like given the 5$^{arcminute}$ resolution of the instrument. The integral flux above 1 TeV is 2.5% of the Crab Nebula flux and significant emission is measured between 250 GeV and 4 TeV, well described by a power-law energy spectrum dN/dE $\sim$ E$^{-��}$ with a photon index $��= 2.39\pm0.23_{stat}\pm0.30_{sys}$. We find no evidence of time variability among observations spanning almost two years. Based on the location, the morphology, the measured spectrum, the lack of variability and a comparison with similar systems previously detected in the TeV band, the most likely counterpart of this new VHE gamma-ray source is the PWN in the SNR G54.1+0.3. The measured X-ray to VHE gamma-ray luminosity ratio is the lowest among all the nebulae supposedly driven by young rotation-powered pulsars, which could indicate a particle-dominated PWN., 5 pages, 2 figure, Latex, emulateapj style, accepted by the Astrophysical Journal Letters
Published: 2010
Full Text: View/download PDF

15. VERITAS Search for VHE Gamma-ray Emission from Dwarf Spheroidal Galaxies

Author: The VERITAS Collaboration, Acciari, V. A., Arlen, T., Aune, T., Beilicke, M., Benbow, W., Boltuch, D., Bradbury, S. M., Buckley, J. H., Bugaev, V., Byrum, K., Cannon, A., Cesarini, A., Christiansen, J. L., Ciupik, L., Cui, W., Dickherber, R., Duke, C., Finley, J. P., Finnegan, G., Furniss, A., Galante, N., Godambe, S., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Holder, J., Hui, C. M., Humensky, T. B., Imran, A., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D., Konopelko, A., Krawczynski, H., Krennrich, F., Maier, G., McArthur, S., McCann, A., McCutcheon, M., Moriarty, P., Ong, R. A., Otte, A. N., Pandel, D., Perkins, J. S., Pohl, M., Quinn, J., Ragan, K., Reyes, L. C., Reynolds, P. T., Roache, E., Rose, H. J., Schroedter, M., Sembroski, G. H., Senturk, G. Demet, Smith, A. W., Steele, D., Swordy, S. P., Te��i��, G., Theiling, M., Thibadeau, S., Varlotta, A., Vassiliev, V. V., Vincent, S., Wagner, R. G., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., Weisgarber, T., Williams, D. A., Wissel, S., Wood, M. D., and Zitzer, B.
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO), velocity dispersion profiles, Astrophysics::High Energy Astrophysical Phenomena, Dark matter, FOS: Physical sciences, Ursa Minor, Astrophysics, exploring halo substructure, Astrophysics::Cosmology and Extragalactic Astrophysics, telescope, 01 natural sciences, dark matter, 0103 physical sciences, gamma rays: galaxies, dark-matter substructure, giant stars, 010303 astronomy & astrophysics, milky-way halo, galactic-center, Astrophysics::Galaxy Astrophysics, Dwarf galaxy, Physics, 010308 nuclear & particles physics, density profiles, Astronomy and Astrophysics, BOOTES, galaxies: dwarf, Galaxy, draco, Space and Planetary Science, Weakly interacting massive particles, Neutralino, ursa-minor, Minimal Supersymmetric Standard Model, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: Indirect dark matter searches with ground-based gamma-ray observatories provide an alternative for identifying the particle nature of dark matter that is complementary to that of direct search or accelerator production experiments. We present the results of observations of the dwarf spheroidal galaxies Draco, Ursa Minor, Bootes 1, and Willman 1 conducted by VERITAS. These galaxies are nearby dark matter dominated objects located at a typical distance of several tens of kiloparsecs for which there are good measurements of the dark matter density profile from stellar velocity measurements. Since the conventional astrophysical background of very high energy gamma rays from these objects appears to be negligible, they are good targets to search for the secondary gamma-ray photons produced by interacting or decaying dark matter particles. No significant gamma-ray flux above 200 GeV was detected from these four dwarf galaxies for a typical exposure of ~20 hours. The 95% confidence upper limits on the integral gamma-ray flux are in the range 0.4-2.2x10^-12 photons cm^-2s^-1. We interpret this limiting flux in the context of pair annihilation of weakly interacting massive particles and derive constraints on the thermally averaged product of the total self-annihilation cross section and the relative velocity of the WIMPs. The limits are obtained under conservative assumptions regarding the dark matter distribution in dwarf galaxies and are approximately three orders of magnitude above the generic theoretical prediction for WIMPs in the minimal supersymmetric standard model framework. However significant uncertainty exists in the dark matter distribution as well as the neutralino cross sections which under favorable assumptions could further lower the limits., Comment: 21 pages, 2 figures, updated to reflect version published in ApJ. NOTE: M.D. Wood added as author
Published: 2010
Full Text: View/download PDF

16. Detection of extended vhe gamma ray emission from g106.3+2.7 with veritas

Author: VERITAS Collaboration, Acciari, V. A., Aliu, E., Arlen, T., Aune, T., Bautista, M., Beilicke, M., Benbow, W., Boltuch, D., Bradbury, S. M., Buckley, J. H., Bugaev, V., Butt, Y., Byrum, K., Cannon, A., Cesarini, A., Chow, Y. C., Ciupik, L., Cogan, P., Cui, W., Dickherber, R., Ergin, T., Fegan, S. J., Finley, J. P., Fortin, P., Fortson, L., Furniss, A., Gall, D., Gillanders, G. H., Gotthelf, E. V., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Holder, J., Horan, D., Hui, C. M., Humensky, T. B., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., LeBohec, S., Maier, G., McCann, A., McCutcheon, M., Millis, J., Moriarty, P., Mukherjee, R., Ong, R. A., Otte, A. N., Pandel, D., Perkins, J. S., Pohl, M., Quinn, J., Ragan, K., Reyes, L. C., Reynolds, P. T., Roache, E., Rose, H. J., Schroedter, M., Sembroski, G. H., Smith, A. W., Steele, D., Swordy, S. P., Theiling, M., Toner, J. A., Vassiliev, V. V., Vincent, S., Wagner, R. G., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., Weisgarber, T., Williams, D. A., Wissel, S., Wood, M., and Zitzer, B.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Context (language use), Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, pulsar wind nebulae, molecular clouds, telescope, 01 natural sciences, Pulsar wind nebula, law.invention, Telescope, Pulsar, law, 0103 physical sciences, Supernova remnant, 010303 astronomy & astrophysics, Cherenkov radiation, Astrophysics::Galaxy Astrophysics, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, supernova remnants, 010308 nuclear & particles physics, Gamma ray, Astronomy and Astrophysics, field, astronomy, supernova remnant, Crab Nebula, Space and Planetary Science, source list, ism: individual (g106.3+2.7=ver j2227+608), galactic-plane survey, High Energy Physics::Experiment, pulsars: individual (j2229+6114), Astrophysics - High Energy Astrophysical Phenomena, source 3eg j2227+6122, gamma rays: observations, discovery
Abstract: We report the detection of very-high-energy (VHE) gamma-ray emission from supernova remnant (SNR) G106.3+2.7. Observations performed in 2008 with the VERITAS atmospheric Cherenkov gamma-ray telescope resolve extended emission overlapping the elongated radio SNR. The 7.3 sigma (pre-trials) detection has a full angular extent of roughly 0.6deg by 0.4deg. Most notably, the centroid of the VHE emission is centered near the peak of the coincident 12CO (J = 1-0) emission, 0.4deg away from the pulsar PSR J2229+6114, situated at the northern end of the SNR. Evidently the current-epoch particles from the pulsar wind nebula are not participating in the gamma-ray production. The VHE energy spectrum measured with VERITAS is well characterized by a power law dN/dE = N_0(E/3 TeV)^{-G} with a differential index of G = 2.29 +/- 0.33stat +/- 0.30sys and a flux of N_0 = (1.15 +/- 0.27stat +/- 0.35sys)x 10^{-13} cm^{-2} s^{-1} TeV^{-1}. The integral flux above 1 TeV corresponds to ~5 percent of the steady Crab Nebula emission above the same energy. We describe the observations and analysis of the object and briefly discuss the implications of the detection in a multiwavelength context., 5 pages, 2 figures
Published: 2009

17. Multiwavelength Observations of LS I +61 303 with VERITAS, Swift and RXTE

Author: VERITAS Collaboration, Acciari, V. A., Aliu, E., Arlen, T., Bautista, M., Beilicke, M., Benbow, W., Bottcher, M., Bradbury, S. M., Bugaev, V., Butt, Y., Byrum0, K., Cannon, A., Cesarini, A., Chow, Y. C., Ciupik, L., Cogan, P., Colin, P., Cui, W., Daniel, M., Dickherber, R., Ergin, T., Falcone, A., Fegan, S. J., Finley, J. P., Fortin, P., Fortson, L., Furniss, A., Gall, D., Gillanders, G. H., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Hays, E., Holder, J., Horan, D., Hui, C. M., Humensky, T. B., Kaaret, P., Karlsson, N., Kieda, D., Kildea, J., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., LeBohec, S., Maier, G., McCann, A., McCutcheon, M., Millis, J., Moriarty, P., Mukherjee, R., Nagai, T., Ong, R. A., Otte, A. N., Pandel, D., Perkins, J. S., Pohl, M., Quinn, J., Ragan, K., Reyes, L. C., Reynolds, P. T., Roache, E., Rose, H. J., Schroedter, M., Sembroski, G. H., Smith, A. W., Steele, D., Stroh, M., Swordy, S., Theiling, M., Toner, J. A., Varlotta, A., Vassiliev, V. V., Wagner, R. G., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinsteiny, A., White, R. J., Williams, D. A., Wissely, S., Woody, M., and Zitzer, B.
Subjects: Swift, Be star, Astrophysics::High Energy Astrophysical Phenomena, ls-i-+61-303, Binary number, Flux, FOS: Physical sciences, Astrophysics, Compact star, telescope, energy gamma-rays, 01 natural sciences, spectrum, microquasar ls-i+61-303, 0103 physical sciences, +61-degrees-303, 010303 astronomy & astrophysics, computer.programming_language, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), lsi+61-degrees-303, timing-explorer, 010308 nuclear & particles physics, Sigma, Astronomy and Astrophysics, x-ray binary, radio, Crab Nebula, binaries: general, 13. Climate action, Space and Planetary Science, x-rays: binaries, Astrophysics - High Energy Astrophysical Phenomena, computer, gamma rays: observations
Abstract: We present results from a long-term monitoring campaign on the TeV binary LSI +61 303 with VERITAS at energies above 500 GeV, and in the 2-10 keV hard X-ray bands with RXTE and Swift, sampling nine 26.5 day orbital cycles between September 2006 and February 2008. The binary was observed by VERITAS to be variable, with all integrated observations resulting in a detection at the 8.8 sigma (2006/2007) and 7.3 sigma (2007/2008) significance level for emission above 500 GeV. The source was detected during active periods with flux values ranging from 5 to 20% of the Crab Nebula, varying over the course of a single orbital cycle. Additionally, the observations conducted in the 2007-2008 observing season show marginal evidence (at the 3.6 sigma significance level) for TeV emission outside of the apastron passage of the compact object around the Be star. Contemporaneous hard X-ray observations with RXTE and Swift show large variability with flux values typically varying between 0.5 and 3.0*10^-11 ergs cm^-2 s^-1 over a single orbital cycle. The contemporaneous X-ray and TeV data are examined and it is shown that the TeV sampling is not dense enough to detect a correlation between the two bands., 30 pages, 5 figures, 2 table, Accepted for publication in The Astrophysical Journal
Published: 2009

18. Veritas observations of a very high energy γ-ray flare from the blazar 3c 66a

Author: VERITAS Collaboration, Acciari, V. A., Aliu, E., Arlen, T., Beilicke, M., Benbow, W., Bottcher, M., Bradbury, S. M., Buckley, J. H., Bugaev, V., Butt, Y., Byrum, K., Cannon, A., Celik, O., Cesarini, A., Chow, Y. C., Ciupik, L., Cogan, P., Cui, W., Daniel, M. K., Dickherber, R., Ergin, T., Falcone, A., Fegan, S. J., Finley, J. P., Fortin, P., Fortson, L., Furniss, A., Gall, D., Gibbs, K., Gillanders, G. H., Godambe, S., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Hays, E., Holder, J., Horan, D., Hui, C. M., Humensky, T. B., Imran, A., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D., Kildea, J., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., LeBohec, S., Maier, G., McCann, A., McCutcheon, M., Millis, J., Moriarty, P., Mukherjee, R., Nagai, T., Ong, R. A., Otte, A. N., Pandel, D., Perkins, J. S., Petry, D., Pizlo, F., Pohl, M., Quinn, J., Ragan, K., Reyes, L. C., Reynolds, P. T., Roache, E., Rose, H. J., Schroedter, M., Sembroski, G. H., Smith, A. W., Steele, D., Swordy, S. P., Theiling, M., Toner, J. A., Varlotta, A., Vassiliev, V. V., Wagner, R. G., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., Williams, D. A., Wissel, S., Wood, M., and Zitzer, B.
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO), Photon, Radio galaxy, Astrophysics::High Energy Astrophysical Phenomena, galaxies: active, FOS: Physical sciences, Flux, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, array, 3c-66a, 01 natural sciences, law.invention, atmospheric cherenkov telescopes, bl lacertae objects, law, 0103 physical sciences, emission, Blazar, 010303 astronomy & astrophysics, Cherenkov radiation, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, 010308 nuclear & particles physics, Gamma ray, opacity, Astronomy and Astrophysics, radiation, astronomy, Crab Nebula, x-ray, 13. Climate action, Space and Planetary Science, bl lacertae objects: individual (3c 66a), Astrophysics - High Energy Astrophysical Phenomena, gamma rays: observations, discovery, Astrophysics - Cosmology and Nongalactic Astrophysics, Flare
Abstract: The intermediate-frequency peaked BL Lacertae (IBL) object 3C 66A is detected during 2007 - 2008 in VHE (very high energy: E > 100 GeV) gamma-rays with the VERITAS stereoscopic array of imaging atmospheric Cherenkov telescopes. An excess of 1791 events is detected, corresponding to a significance of 21.2 standard deviations (sigma), in these observations (32.8 hours live time). The observed integral flux above 200 GeV is 6% of the Crab Nebula's flux and shows evidence for variability on the time-scale of days. The measured energy spectrum is characterized by a soft power law with photon index Gamma = 4.1 +- 0.4_stat +- 0.6_sys. The radio galaxy 3C 66B is excluded as a possible source of the VHE emission., 13 Pages, 4 Figures. Published in ApJL. This new version correctly calculates the intrinsic photon index (see Erratum: ApJL, 721:L203-L204)
Published: 2009

19. VERITAS Upper Limit on the VHE Emission from the Radio Galaxy NGC 1275

Author: VERITAS Collaboration, Acciari, V. A., Aliu, E., Arlen, T., Aune, T., Bautista, M., Beilicke, M., Benbow, W., Boltuch, D., Bradbury, S. M., Buckley, J. H., Bugaev, V., Byrum, K., Cannon, A., Celik, O., Cesarini, A., Ciupik, L., Cogan, P., Cui, W., Dickherber, R., Duke, C., Fegan, S. J., Finley, J. P., Fortin, P., Fortson, L., Furniss, A., Galante, N., Gall, D., Gibbs, K., Gillanders, G. H., Godambe, S., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Holder, J., Horan, D., Hui, C. M., Humensky, T. B., Imran, A., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., LeBohec, S., Maier, G., McCann, A., McCutcheon, M., Millis, J., Moriarty, P., Mukherjee, R., Ong, R. A., Otte, A. N., Pandel, D., Perkins, J. S., Pohl, M., Quinn, J., Ragan, K., Reynolds, P. T., Roache, E., Rose, H. J., Schroedter, M., Sembroski, G. H., Smith, A. W., Steele, D., Swordy, S. P., Theiling, M., Toner, J. A., Varlotta, A., Vassiliev, V. V., Vincent, S., Wagner, R. G., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., Weisgarber, T., Williams, D. A., Wissel, S., Wood, M., Zitzer, B., Kataoka, J., Cavazzuti, E., Cheung, C. C., Lott, B., Thompson, D. J., and Tosti, G.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics::Galaxy Astrophysics
Abstract: The recent detection by the Fermi gamma-ray space telescope of high-energy gamma-rays from the radio galaxy NGC 1275 makes the observation of the very high energy (VHE: E > 100 GeV) part of its broadband spectrum particularly interesting, especially for the understanding of active galactic nuclei (AGN) with misaligned multi-structured jets. The radio galaxy NGC 1275 was recently observed by VERITAS at energies above 100 GeV for about 8 hours. No VHE gamma-ray emission was detected by VERITAS from NGC 1275. A 99% confidence level upper limit of 2.1% of the Crab Nebula flux level is obtained at the decorrelation energy of approximately 340 GeV, corresponding to 19% of the power-law extrapolation of the Fermi Large Area Telescope (LAT) result., Accepted for publication in ApJ Letters
Published: 2009
Full Text: View/download PDF

20. Radio imaging of the very-high-energy gamma-ray emission region in the central engine of a radio galaxy

Author: Veritas, Collaboration, Monitoring Team, Vlba Ghz M., Collaboration, H. E. S. S., Magic, Collaboration, Acciari, V. A., Aliu, E., Arlen, T., Bautista, M., Beilicke, M., Benbow, W., Bradbury, S. M., Buckley, J. H., Bugaev, V., Butt, Y., Byrum, K., Cannon, A., Celik, O., Cesarini, A., Chow, Y. C., Ciupik, L., Cogan, P., Cui, W., Dickherber, R., Fegan, S. J., Finley, J. P., Fortin, P., Fortson, L., Furniss, A., Gall, D., Gillanders, G. H., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Holder, J., Horan, D., Hui, C. M., Humensky, T. B., Imran, A., Kaaret, P., Karlsson, N., Kieda, D., Kildea, J., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., Lebohec, S., Maier, G., Mccann, A., Mccutcheon, M., Millis, J., Moriarty, P., Ong, R. A., Otte, A. N., Pandel, D., Perkins, J. S., Petry, D., Pohl, M., Quinn, J., Ragan, K., Reyes, L. C., Reynolds, P. T., Roache, E., Rose, H. J., Schroedter, M., Sembroski, G. H., Smith, A. W., Swordy, S. P., Theiling, M., Toner, J. A., Varlotta, A., Vincent, S., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., Williams, D. A., Wissel, S., Wood, M., Walker, R. C., Davies, F., Hardee, P. E., Junor, W., Ly, C., Aharonian, F., Akhperjanian, A. G., Anton, G., Barres Almeida, U., Bazer-Bachi, A. R., Becherini, Y., Behera, B., Bernlohr, K., Bochow, A., Boisson, C., Bolmont, J., Borrel, V., Brucker, J., Brun, F., Brun, P., Buhler, R., Bulik, T., Busching, I., Boutelier, T., Chadwick, P. M., Charbonnier, A., Chaves, R. C. G., Cheesebrough, A., Chounet, L-M, Clapson, A. C., Coignet, G., Dalton, M., Daniel, M. K., Davids, I. D., Degrange, B., Deil, C., Dickinson, H. J., Djannati-Atai, A., Domainko, W., Drury, L. O. C., Dubois, F., Dubus, G., Dyks, J., Dyrda, M., Egberts, K., Emmanoulopoulos, D., Espigat, P., Farnier, C., Feinstein, F., Fiasson, A., Forster, A., Fontaine, G., Fussling, M., Gabici, S., Gallant, Y. A., Gerard, L., Gerbig, D., Giebels, B., Glicenstein, J. F., Gluck, B., Goret, P., Gohring, D., Hauser, D., Hauser, M., Heinz, S., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hoffmann, A., Hofmann, W., Holleran, M., Hoppe, S., Horns, D., Jacholkowska, A., Jager, O. C., Jahn, C., Jung, I., Katarzynski, K., Katz, U., Kaufmann, S., Kendziorra, E., Kerschhaggl, M., Khangulyan, D., Khelifi, B., Keogh, D., Kluzniak, W., Kneiske, T., Komin, Nu, Kosack, K., Lamanna, G., Lenain, J-P, Lohse, T., Marandon, V., Martin, J. M., Martineau-Huynh, O., Marcowith, A., Maurin, D., Mccomb, T. J. L., Medina, M. C., Moderski, R., Moulin, E., Naumann-Godo, M., Naurois, M., Nedbal, D., Nekrassov, D., Nicholas, B., Niemiec, J., Nolan, S. J., Ohm, S., Olive, J-F, Ona Wilhelmi, E., Orford, K. J., Ostrowski, M., Panter, M., Paz Arribas, M., Pedaletti, G., Pelletier, G., Petrucci, P-O, Pita, S., Puhlhofer, G., Punch, M., Quirrenbach, A., Raubenheimer, B. C., Raue, M., Rayner, S. M., Renaud, M., Rieger, F., Ripken, J., Rob, L., Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C. B., Ruppel, J., Sahakian, V., Santangelo, A., Schlickeiser, R., Schock, F. M., Schroder, R., Schwanke, U., Schwarzburg, S., Schwemmer, S., Shalchi, A., Sikora, M., Skilton, J. L., Sol, H., Spangler, D., Stawarz, L., Steenkamp, R., Stegmann, C., Stinzing, F., Superina, G., Szostek, A., Tam, P. H., Tavernet, J-P, Terrier, R., Tibolla, O., Tluczykont, M., Christopher van Eldik, Vasileiadis, G., Venter, C., Venter, L., Vialle, J. P., Vincent, P., Vivier, M., Volk, H. J., Volpe, F., Wagner, S. J., Ward, M., Zdziarski, A. A., Zech, A., Anderhub, H., Antonelli, L. A., Antoranz, P., Backes, M., Baixeras, C., Balestra, S., Barrio, J. A., Bastieri, D., Becerra Gonzalez, J., Becker, J. K., Bednarek, W., Berger, K., Bernardini, E., Biland, A., Bock, R. K., Bonnoli, G., Bordas, P., Borla Tridon, D., Bosch-Ramon, V., Bose, D., Braun, I., Bretz, T., Britvitch, I., Camara, M., Carmona, E., Commichau, S., Contreras, J. L., Cortina, J., Costado, M. T., Covino, S., Curtef, V., Dazzi, F., Angelis, A., Cea Del Pozo, E., Delgado Mendez, C., Los Reyes, R., Lotto, B., Maria, M., Sabata, F., Dominguez, A., Dorner, D., Doro, M., Elsaesser, D., Errando, M., Ferenc, D., Fernandez, E., Firpo, R., Fonseca, M. V., Font, L., Galante, N., Garcia Lopez, R. J., Garczarczyk, M., Gaug, M., Goebel, F., Hadasch, D., Hayashida, M., Herrero, A., Hildebrand, D., Hohne-Monch, D., Hose, J., Hsu, C. C., Jogler, T., Kranich, D., La Barbera, A., Laille, A., Leonardo, E., Lindfors, E., Lombardi, S., Longo, F., Lopez, M., Lorenz, E., Majumdar, P., Maneva, G., Mankuzhiyil, N., Mannheim, K., Maraschi, L., Mariotti, M., Martinez, M., Mazin, D., Meucci, M., Miranda, J. M., Mirzoyan, R., Miyamoto, H., Moldon, J., Moles, M., Moralejo, A., Nieto, D., Nilsson, K., Ninkovic, J., Oya, I., Paoletti, R., Paredes, J. M., Pasanen, M., Pascoli, D., Pauss, F., Pegna, R. G., Perez-Torres, M. A., Persic, M., Peruzzo, L., Prada, F., Prandini, E., Puchades, N., Reichardt, I., Rhode, W., Ribo, M., Rico, J., Rissi, M., Robert, A., Rugamer, S., Saggion, A., Saito, T. Y., Salvati, M., Sanchez-Conde, M., Satalecka, K., Scalzotto, V., Scapin, V., Schweizer, T., Shayduk, M., Shore, S. N., Sidro, N., Sierpowska-Bartosik, A., Sillanpaa, A., Sitarek, J., Sobczynska, D., Spanier, F., Stamerra, A., Stark, L. S., Takalo, L., Tavecchio, F., Temnikov, P., Tescaro, D., Teshima, M., Torres, D. F., Turini, N., Vankov, H., Wagner, R. M., Zabalza, V., Zandanel, F., Zanin, R., Zapatero, J., Centre d'étude spatiale des rayonnements (CESR), 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, AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Pierre et Marie Curie - Paris 6 (UPMC), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), APC - Astrophysique des Hautes Energies (APC - AHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Dipartimento di Astronomia, Universita degli Studi di Bologna, Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO)-Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), HESS, Universitat de Barcelona, Université Toulouse III - Paul Sabatier (UT3), 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), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Dipartimento di Astronomia, Universita degli Studi di Bologna, Università di Bologna [Bologna] (UNIBO)-Università di Bologna [Bologna] (UNIBO)-AstroParticule et Cosmologie (APC (UMR_7164)), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, 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), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), V. A., Acciari, E., Aliu, T., Arlen, M., Bautista, M., Beilicke, W., Benbow, S. M., Bradbury, J. H., Buckley, V., Bugaev, Y., Butt, K., Byrum, A., Cannon, O., Celik, A., Cesarini, Y. C., Chow, L., Ciupik, P., Cogan, W., Cui, R., Dickherber, S. J., Fegan, J. P., Finley, P., Fortin, L., Fortson, A., Furni, D., Gall, G. H., Gillander, J., Grube, R., Guenette, G., Gyuk, D., Hanna, J., Holder, D., Horan, C. M., Hui, T. B., Humensky, A., Imran, P., Kaaret, N., Karlsson, D., Kieda, J., Kildea, A., Konopelko, H., Krawczynski, F., Krennrich, M. J., Lang, S., Lebohec, G., Maier, A., Mccann, M., Mccutcheon, J., Milli, P., Moriarty, R. A., Ong, A. N., Otte, D., Pandel, J. S., Perkin, D., Petry, M., Pohl, J., Quinn, K., Ragan, L. C., Reye, P. T., Reynold, E., Roache, H. J., Rose, M., Schroedter, G. H., Sembroski, A. W., Smith, S. P., Swordy, M., Theiling, J. A., Toner, A., Varlotta, S., Vincent, S. P., Wakely, J. E., Ward, T. C., Weeke, A., Weinstein, D. A., William, S., Wissel, M., Wood, R. C., Walker, F., Davie, P. E., Hardee, W., Junor, C., Ly, F., Aharonian, A. G., Akhperjanian, G., Anton, U. B., de Almeida, A. R., Bazer Bachi, Y., Becherini, B., Behera, K., Bernlohr, A., Bochow, C., Boisson, J., Bolmont, V., Borrel, J., Brucker, F., Brun, P., Brun, R., Buhler, T., Bulik, I., Busching, T., Boutelier, P. M., Chadwick, A., Charbonnier, R. C. G., Chave, A., Cheesebrough, L. M., Chounet, A. C., Clapson, G., Coignet, M., Dalton, M. K., Daniel, I. D., David, B., Degrange, C., Deil, H. J., Dickinson, A., Djannati Atai, W., Domainko, L. O., Drury, F., Duboi, G., Dubu, J., Dyk, M., Dyrda, K., Egbert, D., Emmanoulopoulo, P., Espigat, C., Farnier, F., Feinstein, A., Fiasson, A., Forster, G., Fontaine, M., Fussling, S., Gabici, Y. A., Gallant, L., Gerard, D., Gerbig, B., Giebel, J. F., Glicenstein, B., Gluck, P., Goret, D., Gohring, D., Hauser, M., Hauser, S., Heinz, G., Heinzelmann, G., Henri, G., Hermann, J. A., Hinton, A., Hoffmann, W., Hofmann, M., Holleran, S., Hoppe, D., Horn, A., Jacholkowska, O. C., de Jager, C., Jahn, I., Jung, K., Katarzynski, U., Katz, S., Kaufmann, E., Kendziorra, M., Kerschhaggl, D., Khangulyan, B., Khelifi, D., Keogh, W., Kluzniak, T., Kneiske, N., Komin, K., Kosack, G., Lamanna, J. P., Lenain, T., Lohse, V., Marandon, J. M., Martin, O., Martineau Huynh, A., Marcowith, D., Maurin, T. J. L., Mccomb, M. C., Medina, R., Moderski, E., Moulin, M., Naumann Godo, M. d., Nauroi, D., Nedbal, D., Nekrassov, B., Nichola, J., Niemiec, S. J., Nolan, S., Ohm, J. F., Olive, E. D., Wilhelmi, K. J., Orford, M., Ostrowski, M., Panter, M. P., Arriba, G., Pedaletti, G., Pelletier, P. O., Petrucci, S., Pita, M., Raue, S. M., Rayner, M., Renaud, F., Rieger, J., Ripken, L., Rob, S., Rosier Lee, G., Rowell, B., Rudak, C. B., Rulten, J., Ruppel, V., Sahakian, A., Santangelo, R., Schlickeiser, F. M., Schock, R., Schroder, U., Schwanke, S., Schwarzburg, S., Schwemmer, A., Shalchi, M., Sikora, J. L., Skilton, H., Sol, D., Spangler, L., Stawarz, R., Steenkamp, C., Stegmann, F., Stinzing, G., Superina, A., Szostek, P. H., Tam, J. P., Tavernet, R., Terrier, O., Tibolla, M., Tluczykont, C. v., Eldik, G., Vasileiadi, C., Venter, L., Venter, J. P., Vialle, P., Vincent, M., Vivier, H. J., Volk, F., Volpe, S. J., Wagner, M., Ward, A. A., Zdziarski, A., Zech, H., Anderhub, L. A., Antonelli, P., Antoranz, M., Backe, C., Baixera, S., Balestra, J. A., Barrio, D., Bastieri, J. B., Gonzlez, J. K., Becker, W., Bednarek, K., Berger, E., Bernardini, A., Biland, R. K., Bock, G., Bonnoli, P., Borda, D. B., Tridon, V., Bosch Ramon, D., Bose, I., Braun, T., Bretz, I., Britvitch, M., Camara, E., Carmona, S., Commichau, J. L., Contrera, J., Cortina, M. T., Costado, S., Covino, V., Curtef, F., Dazzi, A. D., Angeli, E. D., Del Pozo, C. D., Mendez, R. D., los Reye, B. D., Lotto, M. D., Maria, F. D., Sabata, A., Dominguez, D., Dorner, M., Doro, D., Elsaesser, M., Errando, D., Ferenc, E., Fernndez, R., Firpo, M. V., Fonseca, L., Font, N., Galante, R. J. G., Lopez, M., Garczarczyk, M., Gaug, F., Goebel, D., Hadasch, M., Hayashida, A., Herrero, D., Hildebrand, D., Hohne Monch, J., Hose, C. C., Hsu, T., Jogler, D., Kranich, A. L., Barbera, A., Laille, E., Leonardo, E., Lindfor, S., Lombardi, Longo, Francesco, M., Lopez, E., Lorenz, P., Majumdar, G., Maneva, N., Mankuzhiyil, K., Mannheim, L., Maraschi, M., Mariotti, M., Martinez, D., Mazin, M., Meucci, J. M., Miranda, R., Mirzoyan, H., Miyamoto, J., Moldon, M., Mole, A., Moralejo, D., Nieto, K., Nilsson, J., Ninkovic, I., Oya, R., Paoletti, J. M., Parede, M., Pasanen, D., Pascoli, F., Pau, R. G., Pegna, M. A., Perez Torre, M., Persic, L., Peruzzo, F., Prada, E., Prandini, N., Puchade, I., Reichardt, W., Rhode, M., Ribo, J., Rico, M., Rissi, A., Robert, S., Rugamer, A., Saggion, T. Y., Saito, M., Salvati, M., Sanchez Conde, K., Satalecka, V., Scalzotto, V., Scapin, T., Schweizer, M., Shayduk, S. N., Shore, N., Sidro, A., Sierpowska Bartosik, A., Sillanpaa, J., Sitarek, D., Sobczynska, F., Spanier, A., Stamerra, L. S., Stark, L., Takalo, F., Tavecchio, P., Temnikov, D., Tescaro, M., Teshima, D. F., Torre, N., Turini, H., Vankov, R. M., Wagner, V., Zabalza, F., Zandanel, R., Zanin, and J., Zapatero
Subjects: m87 jet, Radio galaxy, Astrophysics, telescope, 01 natural sciences, Astroparticle, Jets (Astrofísica), Radio astronomy, 010303 astronomy & astrophysics, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, tev emission, Multidisciplinary, [SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Gamma ray, 3. Good health, Forats negres (Astronomia), Radioastronomia, Electrónica, Física nuclear, Electricidad, Astrophysics - High Energy Astrophysical Phenomena, Very High Energy Gamma-ray Astronomy, MAGIC telescope, Galaxies, Radio wave, outburst, [PHYS.ASTR.HE]Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Active galactic nucleus, inner jet, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, X-shaped radio galaxy, veritas, 0103 physical sciences, Nucli galàctic actiu, crab-nebula, VHE Gamma ray, Astrophysics::Galaxy Astrophysics, Active galactic nuclei, variability, 010308 nuclear & particles physics, nucleus, Astronomy, Astrophysics - Astrophysics of Galaxies, Galaxy, Accretion (astrophysics), Astrophysical jets, Black hole, Cherenkov telescope, Astrophysics of Galaxies (astro-ph.GA), Black holes (Astronomy), supermassive black-hole
Abstract: The accretion of matter onto a massive black hole is believed to feed the relativistic plasma jets found in many active galactic nuclei (AGN). Although some AGN accelerate particles to energies exceeding 10^12 electron Volts (eV) and are bright sources of very-high-energy (VHE) gamma-ray emission, it is not yet known where the VHE emission originates. Here we report on radio and VHE observations of the radio galaxy M87, revealing a period of extremely strong VHE gamma-ray flares accompanied by a strong increase of the radio flux from its nucleus. These results imply that charged particles are accelerated to very high energies in the immediate vicinity of the black hole., Comment: 21 pages, 5 figures, published in Science, see: http://www.sciencemag.org/cgi/content/abstract/325/5939/444
Published: 2009
Full Text: View/download PDF

21. MULTIWAVELENGTH OBSERVATIONS OF A TeV-FLARE FROM W COMAE

Author: Veritas, Collaboration, Acciari, V. A., Aliu, E., Aune, T., Beilicke, M., Benbow, W., Bottcher, M., Boltuch, D., Buckley, J. H., Bradbury, S. M., Bugaev, V., Byrum, K., Cannon, A., Cesarini, A., Ciupik, L., Cogan, P., Cui, W., Dickherber, R., Duke, C., Falcone, A., Finley, J. P., Fortin, P., Fortson, L., Furniss, A., Galante, N., Gall, D., Gibbs, K., Gillanders, G. H., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Holder, J., Hui, C. M., Humensky, T. B., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., Lebohec, S., Maier, G., Mcarthur, S., Mccann, A., Mccutcheon, M., Millis, J., Moriarty, P., Ong, R. A., Otte, A. N., Pandel, D., Perkins, J. S., Pichel, A., Pohl, M., Quinn, J., Ragan, K., Reyes, L. C., Reynolds, P. T., Roache, E., Rose, H. J., Sembroski, G. H., Smith, A. W., Steele, D., Theiling, M., Thibadeau, S., Varlotta, A., Vassiliev, V. V., Vincent, S., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., Weisgarber, T., Williams, D. A., Wissel, S., Wood, M., Agile, The Team, Pian, E., Vercellone, S., Donnarumma, I., D Ammando, F., Bulgarelli, A., Chen, A. W., Giuliani, A., Longo, F., Pacciani, L., Pucella, G., Vittorini, V., Tavani, M., Argan, A., Barbiellini, G., Caraveo, P., Cattaneo, P. W., Cocco, V., Costa, E., Del Monte, E., Paris, G., Di Cocco, G., Evangelista, Y., Feroci, M., Fiorini, M., Froysland, T., Frutti, M., Fuschino, F., Galli, M., Gianotti, F., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Marisaldi, M., Mastropietro, M., Mereghetti, S., Morelli, E., Morselli, A., Pellizzoni, A., Perotti, F., Piano, G., Picozza, P., Pilia, M., Porrovecchio, G., Prest, M., Rapisarda, M., Rappoldi, A., Rubini, A., Soffitta, S. Sabatini P., Trifoglio, M., Trois, A., Vallazza, E., Zambra, A., Zanello, D., Pittori, C., Santolamazza, P., Verrecchia, F., Giommi, P., Colafrancesco, S., Salotti, L., Massimo Villata, Raiteri, C. M., Aller, H. D., Aller, M. F., Arkharov, A. A., Efimova, N. V., Larionov, V. M., Leto, P., Ligustri, R., Lindfors, E., Pasanen, M., Kurtanidze, O. M., Tetradze, S. D., Lahteenmaki, A., Kotiranta, M., Cucchiara, A., Romano, P., Nesci, R., Pursimo, T., Heidt, J., Benitez, E., Hiriart, D., Nilsson, K., Berdyugin, A., Mujica, R., Dultzin, D., Lopez, J. M., Mommert, M., Sorcia, M., La Calle Perez, I., V. A., Acciari, E., Aliu, T., Aune, M., Beilicke, W., Benbow, M., Bottcher, D., Boltuch, J. H., Buckley, S. M., Bradbury, V., Bugaev, K., Byrum, A., Cannon, A., Cesarini, L., Ciupik, P., Cogan, W., Cui, R., Dickherber, C., Duke, A., Falcone, J. P., Finley, P., Fortin, L., Fortson, A., Furni, N., Galante, D., Gall, K., Gibb, G. H., Gillander, J., Grube, R., Guenette, G., Gyuk, D., Hanna, J., Holder, C. M., Hui, T. B., Humensky, P., Kaaret, N., Karlsson, M., Kertzman, D., Kieda, A., Konopelko, H., Krawczynski, F., Krennrich, M. J., Lang, S., Lebohec, G., Maier, S., Mcarthur, A., Mccann, M., Mccutcheon, J., Milli, P., Moriarty, R. A., Ong, A. N., Otte, D., Pandel, J. S., Perkin, A., Pichel, M., Pohl, J., Quinn, K., Ragan, L. C., Reye, P. T., Reynold, E., Roache, H. J., Rose, G. H., Sembroski, A. W., Smith, D., Steele, M., Theiling, S., Thibadeau, A., Varlotta, V. V., Vassiliev, S., Vincent, S. P., Wakely, J. E., Ward, T. C., Weeke, A., Weinstein, T., Weisgarber, D. A., William, S., Wissel, M., Wood, E., Pian, S., Vercellone, I., Donnarumma, F., D'Ammando, A., Bulgarelli, A. W., Chen, A., Giuliani, Longo, Francesco, L., Pacciani, G., Pucella, V., Vittorini, M., Tavani, A., Argan, G., Barbiellini, P., Caraveo, P. W., Cattaneo, V., Cocco, E., Costa, E. D., Monte, G. D., Pari, G. D., Cocco, Y., Evangelista, M., Feroci, M., Fiorini, T., Froysland, M., Frutti, F., Fuschino, M., Galli, F., Gianotti, C., Labanti, I., Lapshov, F., Lazzarotto, P., Lipari, M., Marisaldi, M., Mastropietro, S., Mereghetti, E., Morelli, A., Morselli, A., Pellizzoni, F., Perotti, G., Piano, P., Picozza, M., Pilia, G., Porrovecchio, M., Prest, M., Rapisarda, A., Rappoldi, A., Rubini, S., Sabatini, P., Soffitta, M., Trifoglio, A., Troi, E., Vallazza, A., Zambra, D., Zanello, C., Pittori, P., Santolamazza, F., Verrecchia, P., Giommi, S., Colafrancesco, L., Salotti, M., Villata, C. M., Raiteri, H. D., Aller, M. F., Aller, A. A., Arkharov, N. V., Efimova, V. M., Larionov, P., Leto, R., Ligustri, E., Lindfor, M., Pasanen, O. M., Kurtanidze, S. D., Tetradze, A., Lahteenmaki, M., Kotiranta, A., Cucchiara, P., Romano, R., Nesci, T., Pursimo, J., Heidt, E., Benitez, D., Hiriart, K., Nilsson, A., Berdyugin, R., Mujica, D., Dultzin, J. M., Lopez, M., Mommert, M., Sorcia, I. D., Perez, Acciari VA, Aliu E, Aune T, Beilicke M, Benbow W, Bottcher M, Boltuch D, Buckley JH, Bradbury SM, Bugaev V, Byrum K, Cannon A, Cesarini A, Ciupik L, Cogan P, Cui W, Dickherber R, Duke C, Falcone A, Finley JP, Fortin P, Fortson L, Furniss A, Galante N, Gall D, Gibbs K, Gillanders GH, Grube J, Guenette R, Gyuk G, Hanna D, Holder J, Hui CM, Humensky TB, Kaaret P, Karlsson N, Kertzman M, Kieda D, Konopelko A, Krawczynski H, Krennrich F, Lang MJ, LeBohec S, Maier G, McArthur S, McCann A, McCutcheon M, Millis J, Moriarty P, Ong RA, Otte AN, Pandel D, Perkins JS, Pichel A, Pohl M, Quinn J, Ragan K, Reyes LC, Reynolds PT, Roache E, Rose HJ, Sembroski GH, Smith AW, Steele D, Theiling M, Thibadeau S, Varlotta A, Vassiliev VV, Vincent S, Wakely SP, Ward JE, Weekes TC, Weinstein A, Weisgarber T, Williams DA, Wissel S, Wood M, Pian E, Vercellone S, Donnarumma I, DAmmando F, Bulgarelli A, Chen AW, Giuliani A, Longo F, Pacciani L, Pucella G, Vittorini V, Tavani M, Argan A, Barbiellini G, Caraveo P, Cattaneo PW, Cocco V, Costa E, Del Monte E, De Paris G, Di Cocco G, Evangelista Y, Feroci M, Fiorini M, Froysland T, Frutti M, Fuschino F, Galli M, Gianotti F, Labanti C, Lapshov I, Lazzarotto F, Lipari P, Marisaldi M, Mastropietro M, Mereghetti S, Morelli E, Morselli A, Pellizzoni A, Perotti F, Piano G, Picozza P, Pilia M, Porrovecchio G, Prest M, Rapisarda M, Rappoldi A, Rubini A, Sabatini S, Soffitta P, Trifoglio M, Trois A, Vallazza E, Zambra A, Zanello D, Pittori C, Santolamazza P, Verrecchia F, Giommi P, Colafrancesco S, Salotti L, Villata M, Raiteri CM, Aller HD, Aller MF, Arkharov AA, Efimova NV, Larionov VM, Leto P, Ligustri R, Lindfors E, Pasanen M, Kurtanidze OM, Tetradze SD, Lahteenmaki A, Kotiranta M, Cucchiara A, Romano P, Nesci R, Pursimo T, Heidt J, Benitez E, Hiriart D, Nilsson K, Berdyugin A, Mujica R, Dultzin D, Lopez JM, Mommert M, Sorcia M, and Perez ID
Subjects: Agile, High energy, agile space mission, Astrophysics::High Energy Astrophysical Phenomena, bl-lacertae objects, FOS: Physical sciences, Flux, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, telescope, 01 natural sciences, High Energy Gamma-ray Astronomy, blazar, law.invention, multiwavelength, BL Lacertae, law, 0103 physical sciences, 010303 astronomy & astrophysics, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, 010308 nuclear & particles physics, Very High Energy Gamma-ray Astronomy, AGILE satellite, Active Galactic Nuclei, Gamma ray, background-radiation, Astronomy and Astrophysics, gamma-ray emission, lac objects, spectral energy-distributions, veritas observations, Space and Planetary Science, source list, Spectral energy distribution, BL Lacertae objects: individual (W Com), Astrophysics - High Energy Astrophysical Phenomena, gamma rays: observations, Flare, BL Lac object
Abstract: We report results from an intensive multiwavelength campaign on the intermediate-frequency-peaked BL Lacertae object W Com (z=0.102) during a strong outburst of very high energy gamma-ray emission in June 2008. The very high energy gamma-ray signal was detected by VERITAS on 2008 June 7-8 with a flux F(>200 GeV) = (5.7+-0.6)x10^-11 cm-2s-1, about three times brighter than during the discovery of gamma-ray emission from W Com by VERITAS in 2008 March. The initial detection of this flare by VERITAS at energies above 200 GeV was followed by observations in high energy gamma-rays (AGILE, E>100 MeV), and X-rays (Swift and XMM-Newton), and at UV, and ground-based optical and radio monitoring through the GASP-WEBT consortium and other observatories. Here we describe the multiwavelength data and derive the spectral energy distribution (SED) of the source from contemporaneous data taken throughout the flare., 26 pages, 5 figures; Accepted for publication by The Astrophysical Journal
Published: 2009

22. Veritas discovery of >200 gev gamma-ray emission from the intermediate-frequency-peaked bl lacertae object w comae

Author: VERITAS Collaboration, Acciari, V. A., Aliu, E., Beilicke, M., Benbow, W., Boettcher, M., Bradbury, S. M., Buckley, J. H., Bugaev, V., Butt, Y., Celik, O., Cesarini, A., Ciupik, L., Chow, Y. C. K., Cogan, P., Colin, P., Cui, W., Daniel, M. K., Ergin, T., Falcone, A. D., Fegan, S. J., Finley, J. P., Finnegan, G., Fortin, P., Fortson, L. F., Furniss, A., Gall, D., Gillanders, G. H., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Hays, E., Holder, J., Horan, D., Hui, C. M., Humensky, T. B., Imran, A., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D. B., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., LeBohec, S., Lee, K., Maier, G., McCann, A., McCutcheon, M., Moriarty, P., Mukherjee, R., Nagai, T., Niemiec, J., Ong, R. A., Pandel, D., Perkins, J. S., Petry, D., Pohl, M., Quinn, J., Ragan, K., Reyes, L. C., Reynolds, P. T., Roache, E., Rose, H. J., Schroedter, M., Sembroski, G. H., Smith, A. W., Steele, D., Swordy, S. P., Toner, J. A., Vassiliev, V. V., Wagner, R., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., White, R. J., Williams, D. A., Wissel, S. A., Wood, M., and Zitzer, B.
Subjects: Photon, spectra, Astrophysics::High Energy Astrophysical Phenomena, blazars, Flux, Astrophysics, 01 natural sciences, 7. Clean energy, law.invention, law, 0103 physical sciences, gamma rays : observations, bl lacertae objects : individual (w comae), 010303 astronomy & astrophysics, Physics, high-energy emission, Spectral index, 010308 nuclear & particles physics, radio-sources, Gamma ray, Astronomy and Astrophysics, astronomy, Crab Nebula, 13. Climate action, Space and Planetary Science, Spectral energy distribution, egret, Flare, BL Lac object
Abstract: We report the detection of very high-energy gamma-ray emission from the intermediate-frequency-peaked BL Lacertae object W Comae (z=0.102) by VERITAS. The source was observed between January and April 2008. A strong outburst of gamma-ray emission was measured in the middle of March, lasting for only four days. The energy spectrum measured during the two highest flare nights is fit by a power-law and is found to be very steep, with a differential photon spectral index of Gamma = 3.81 +- 0.35_stat +- 0.34_syst. The integral photon flux above 200GeV during those two nights corresponds to roughly 9% of the flux from the Crab Nebula. Quasi-simultaneous Swift observations at X-ray energies were triggered by the VERITAS observations. The spectral energy distribution of the flare data can be described by synchrotron-self-Compton (SSC) or external-Compton (EC) leptonic jet models, with the latter offering a more natural set of parameters to fit the data., Comment: 7 pages, 4 figures, accepted by ApJL
Published: 2008

23. Veritas observations of the gamma-ray binary LS I+61 303

Author: Acciari, V. A., Beilicke, M., Blaylock, G., Bradbury, S. M., Buckley, J. H., Bugaev, V., Butt, Y., Byrum, K. L., Celik, O., Cesarini, A., Ciupik, L., Chow, Y. C. K., Cogan, P., Colin, P., Cui, W., Daniel, M. K., Duke, C., Ergin, T., Falcone, A. D., Fegan, S. J., Finley, J. P., Fortin, P., Fortson, L. F., Gall, D., Gibbs, K., Gillanders, G. H., Grube, J., Guenette, R., Hanna, D., Hays, E., Holder, J., Horan, D., Hughes, S. B., Hui, C. M., Humensky, T. B., Kaaret, P., Kieda, D. B., Kildea, J., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., LeBohec, S., Lee, K., Maier, G., McCann, A., McCutcheon, M., Millis, J., Moriarty, P., Mukherjee, R., Nagai, T., Ong, R. A., Pandel, D., Perkins, J. S., Pizlo, F., Pohl, M., Quinn, J., Ragan, K., Reynolds, P. T., Rose, H. J., Schroedter, M., Sembroski, G. H., Smith, A. W., Steele, D., Swordy, S. P., Toner, J. A., Valcarcel, L., Vassiliev, V. V., Wagner, R., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., White, R. J., Williams, D. A., Wissel, S. A., Wood, M., and Zitzer, B.
Subjects: acceleration of particles, binaries : general, gamma rays, observations, stars : individual (LS I+61 303), Astronomy & Astrophysics, Astrophysics::High Energy Astrophysical Phenomena, High Energy Physics::Experiment
Abstract: LS I +61 303 is one of only a few high-mass X-ray binaries currently detected at high significance in very high energy gamma-rays. The system was observed over several orbital cycles ( between 2006 September and 2007 February) with the VERITAS array of imaging air Cerenkov telescopes. A signal of gamma-rays with energies above 300 GeV is found with a statistical significance of 8.4 standard deviations. The detected flux is measured to be strongly variable; the maximum flux is found during most orbital cycles at apastron. The energy spectrum for the period of maximum emission can be characterized by a power law with a photon index of Gamma = 2.40 +/- 0.16(stat) +/- 0.2(sys) and a flux above 300 GeV corresponding to 15% - 20% of the flux from the Crab Nebula.
Published: 2008

24. VERITAS Discovery of >200GeV Gamma-ray Emission from the Intermediate-frequency-peaked BL Lac Object W Comae

Author: VERITAS Collaboration, Acciari, V. A., Aliu, E., Beilicke, M., Benbow, W., Boettcher, M., Bradbury, S. M., Buckley, J. H., Bugaev, V., Butt, Y., Celik, O., Cesarini, A., Ciupik, L., Chow, Y. C. K., Cogan, P., Colin, P., Cui, W., Daniel, M. K., Ergin, T., Falcone, A. D., Fegan, S. J., Finley, J. P., Finnegan, G., Fortin, P., Fortson, L. F., Furniss, A., Gall, D., Gillanders, G. H., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Hays, E., Holder, J., Horan, D., Hui, C. M., Humensky, T. B., Imran, A., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D. B., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., LeBohec, S., Lee, K., Maier, G., McCann, A., McCutcheon, M., Moriarty, P., Mukherjee, R., Nagai, T., Niemiec, J., Ong, R. A., Pandel, D., Perkins, J. S., Petry, D., Pohl, M., Quinn, J., Ragan, K., Reyes, L. C., Reynolds, P. T., Roache, E., Rose, H. J., Schroedter, M., Sembroski, G. H., Smith, A. W., Steele, D., Swordy, S. P., Toner, J. A., Vassiliev, V. V., Wagner, R., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., White, R. J., Williams, D. A., Wissel, S. A., Wood, M., and Zitzer, B.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), FOS: Physical sciences
Abstract: We report the detection of very high-energy gamma-ray emission from the intermediate-frequency-peaked BL Lacertae object W Comae (z=0.102) by VERITAS. The source was observed between January and April 2008. A strong outburst of gamma-ray emission was measured in the middle of March, lasting for only four days. The energy spectrum measured during the two highest flare nights is fit by a power-law and is found to be very steep, with a differential photon spectral index of Gamma = 3.81 +- 0.35_stat +- 0.34_syst. The integral photon flux above 200GeV during those two nights corresponds to roughly 9% of the flux from the Crab Nebula. Quasi-simultaneous Swift observations at X-ray energies were triggered by the VERITAS observations. The spectral energy distribution of the flare data can be described by synchrotron-self-Compton (SSC) or external-Compton (EC) leptonic jet models, with the latter offering a more natural set of parameters to fit the data., 7 pages, 4 figures, accepted by ApJL
Published: 2008
Full Text: View/download PDF

25. Observation of gamma-ray emission from the galaxy M87 above 250 GeV with VERITAS

Author: Acciari, V. A., Beilicke, M., Blaylock, G., Bradbury, S. M., Buckley, J. H., Bugaev, V., Butt, Y., Celik, O., Cesarini, A., Ciupik, L., Cogan, P., Colin, P., Cui, W., Daniel, M. K., Duke, C., Ergin, T., Falcone, A. D., Fegan, S. J., Finley, J. P., Finnegan, G., Fortin, P., Fortson, L. F., Gibbs, K., Gillanders, G. H., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Hays, E., Holder, J., Horan, D., Hughes, S. B., Hui, M. C., Humensky, T. B., Imran, A., Kaaret, P., Kertzman, M., Kieda, D. B., Kildea, J., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., LeBohec, S., Lee, K., Maier, G., McCann, A., McCutcheon, M., Millis, J., Moriarty, P., Mukherjee, R., Nagai, T., Ong, R. A., Pandel, D., Perkins, J. S., Pohl, M., Quinn, J., Ragan, K., Reynolds, P. T., Rose, H. J., Schroedter, M., Sembroski, G. H., Smith, A. W., Steele, D., Swordy, S. P., Toner, A. Syson J. A., Valcarcel, L., Vassiliev, V. V., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., White, R. J., Williams, D. A., Wissel, S. A., Wood, M. D., and Zitzer, B.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), FOS: Physical sciences, High Energy Physics::Experiment, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: The multiwavelength observation of the nearby radio galaxy M87 provides a unique opportunity to study in detail processes occurring in Active Galactic Nuclei from radio waves to TeV gamma-rays. Here we report the detection of gamma-ray emission above 250 GeV from M87 in spring 2007 with the VERITAS atmospheric Cherenkov telescope array and discuss its correlation with the X-ray emission. The gamma-ray emission is measured to be point-like with an intrinsic source radius less than 4.5 arcmin. The differential energy spectrum is fitted well by a power-law function: dPhi/dE=(7.4+-1.3_{stat}+-1.5_{sys})(E/TeV)^{-2.31+-0.17_{stat}+-0.2_{sys}} 10^{-9}m^{-2}s^{-1}TeV^{-1}. We show strong evidence for a year-scale correlation between the gamma-ray flux reported by TeV experiments and the X-ray emission measured by the ASM/RXTE observatory, and discuss the possible short-time-scale variability. These results imply that the gamma-ray emission from M87 is more likely associated with the core of the galaxy than with other bright X-ray features in the jet., Comment: 10 pages, 7 figures, accepted for publication in The Astrophysical Journal
Published: 2008
Full Text: View/download PDF

26. Observation of gamma-ray emission from the galaxy M87 above 250 GeV with VERITAS

Author: Acciari, V. A., Beilicke, M., Blaylock, G., Bradbury, S. M., Buckley, J. H., Bugaev, V., Butt, Y., Celik, O., Cesarini, A., Ciupik, L., Cogan, P., Colin, P., Cui, W., Daniel, M. K., Duke, C., Ergin, T., Falcone, A. D., Fegan, S. J., Finley, J. P., Finnegan, G., Fortin, P., Fortson, L. F., Gibbs, K., Gillanders, G. H., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Hays, E., Holder, J., Horan, D., Hughes, S. B., Hui, M. C., Humensky, T. B., Imran, A., Kaaret, P., Kertzman, M., Kieda, D. B., Kildea, J., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., LeBohec, S., Lee, K., Maier, G., McCann, A., McCutcheon, M., Millis, J., Moriarty, P., Mukherjee, R., Nagai, T., Ong, R. A., Pandel, D., Perkins, J. S., Pohl, M., Quinn, J., Ragan, K., Reynolds, P. T., Rose, H. J., Schroedter, M., Sembroski, G. H., Smith, A. W., Steele, D., Swordy, S. P., Syson, A., Toner, J. A., Valcarcel, L., Vassiliev, V. V., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., White, R. J., Williams, D. A., Wissel, S. A., Wood, M. D., and Zitzer, B.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, galaxies : individual (M87, NGC 4486, Virgo A), gamma rays, observations, Astronomy & Astrophysics, High Energy Physics::Experiment, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: The multiwavelength observation of the nearby radio galaxy M87 provides a unique opportunity to study in detail processes occurring in active galactic nuclei from radio waves to TeV gamma-rays. Here we report the detection of gamma-ray emission above 250 GeV from M87 in spring 2007 with the VERITAS atmospheric Cerenkov telescope array and discuss its correlation with the X-ray emission. The gamma-ray emission is measured to be pointlike with an intrinsic source radius less than 4.5'. The differential energy spectrum is fitted well by a power-law function: d Phi/dE = (7.4 +/- 1.3(stat) +/- 1.5(sys))(E/TeV)((-2.31 +/- 0.17stat +/- 0.2sys)) 10(-9) m(-2) s(-1) TeV-1. We show strong evidence for a year-scale correlation between the gamma-ray flux reported by TeV experiments and the X-ray emission measured by the ASM RXTE observatory, and discuss the possible short-timescale variability. These results imply that the gamma-ray emission from M87 is more likely associated with the core of the galaxy than with other bright X-ray features in the jet.
Published: 2008

27. Very High Energy Observations of Gamma-Ray Burst Locations with the Whipple Telescope

Author: Lang, Mark, Gillanders, Gary, Horan, D., Atkins, R. W., Badran, H. M., Blaylock, G., Bradbury, S. M., Buckley, J. H., Byrum, K. L., Celik, O., Chow, Y. C. K., Cogan, P., Cui, W., Daniel, M. K., Perez, I. de la Calle, Dowdall, C., Falcone, A. D., Fegan, D. J., Fegan, S. J., Finley, J. P., Fortin, P., Fortson, L. F., Gillanders, G. H., Grube, J., Gutierrez, K. J., Hall, J., Hanna, D., Holder, J., Hughes, S. B., Humensky, T. B., Kenny, G. E., Kertzman, M., Kieda, D. B., Kildea, J., Krawczynski, H., Krennrich, F., Lang, M. J., LeBohec, S., Maier, G., Moriarty, P., Nagai, T., Ong, R. A., Perkins, J. S., Petry, D., Quinn, J., Quinn, M., Ragan, K., Reynolds, P. T., Rose, H. J., Schroedter, M., Sembroski, G. H., Steele, D., Swordy, S. P., Toner, J. A., Valcarcel, L., Vassiliev, V. V., Wagner, R. G., Wakely, S. P., Weekes, T. C., White, R. J., and Williams, D. A.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics
Abstract: Gamma-ray burst (GRB) observations at very high energies (VHE, E > 100 GeV) can impose tight constraints on some GRB emission models. Many GRB afterglow models predict a VHE component similar to that seen in blazars and plerions, in which the GRB spectral energy distribution has a double-peaked shape extending into the VHE regime. VHE emission coincident with delayed X-ray flare emission has also been predicted. GRB follow-up observations have had high priority in the observing program at the Whipple 10m Gamma-ray Telescope and GRBs will continue to be high priority targets as the next generation observatory, VERITAS, comes on-line. Upper limits on the VHE emission, at late times (>~4 hours), from seven GRBs observed with the Whipple Telescope are reported here. peer-reviewed
Published: 2007

28. Multiwavelength observations of the blazar Markarian 421 in 2002 December and 2003 January

Author: Rebillot, P. F., Badran, H. M., Blaylock, G., Bradbury, S. M., Buckley, J. H., Carter-Lewis, D. A., Celik, O., Chow, Y. C., Cogan, P., Cui, W., Daniel, M., Duke, C., Falcone, A., Fegan, S. J., Finley, J. P., Fortson, L. F., Gillanders, G. H., Grube, J., Gutierrez, K., Gyuk, G., Hanna, D., Holder, J., Horan, D., Hughes, S. B., Kenny, G. E., Kertzman, M., Kieda, D., Kildea, J., Kosack, K., Krawczynski, H., Krennrich, F., Lang, M. J., Le Bohec, S., Linton, E., Maier, G., Moriarty, P., Perkins, J., Pohl, M., Quinn, J., Ragan, K., Reynolds, P. T., Rose, H. J., Schroedter, M., Sembroski, G. H., Steele, G., Swordy, S. P., Valcarcel, L., Vassiliev, V. V., Wakely, S. P., Weekes, T. C., Zweerink, J., Aller, M., Aller, H., Boltwood, P., Jung, I., Kranich, D., Nilsson, K., Pasanen, M., Sadun, A., and Sillanpaa, A.
Subjects: bl lacertae objects : individual (mrk 421), galaxies : jets, gamma rays : observations radiation, mechanisms : nonthermal, x-rays : individual (mrk 421), tev gamma-rays, active galactic nuclei, bl-lacertae objects, self-compton model, x-ray, spectral evolution, lac objects, strong flares, crab-nebula, mkn 501, Astrophysics::High Energy Astrophysical Phenomena
Abstract: We report on a multiwavelength campaign on the TeV gamma-ray blazar Mrk 421 performed during 2002 December and 2003 January. These target of opportunity observations were initiated by the detection of X-ray and TeV gamma-ray flares with the All Sky Monitor (ASM) on board the Rossi X-Ray Timing Explorer (RXTE) and the 10 m Whipple gamma-ray telescope. The campaign included observational coverage in the radio (University of Michigan Radio Astronomy Observatory), optical (Boltwood, La Palma KVA 0.6 m; WIYN 0.9 m), X-ray (RXTE pointed telescopes), and TeV gamma-ray (Whipple and HEGRA) bands. At TeV energies, the observations revealed several flares at intermediate flux levels, peaking between 1 and 1.5 times the flux from the Crab Nebula. While the time-averaged spectrum can be fitted with a single power law of photon index Gamma = 2.8 from dN gamma/dE proportional to E-Gamma, we find some evidence for spectral variability. Confirming earlier results, the campaign reveals a rather loose correlation between the X-ray and TeV gamma-ray fluxes. In one case, a very strong X-ray flare is not accompanied by a comparable TeV gamma-ray flare. Although the source flux was variable in the optical and radio bands, the sparse sampling of the optical and radio light curves does not allow us to study the correlation properties in detail. We present a simple analysis of the data with a synchrotron self-Compton model, emphasizing that models with very high Doppler factors and low magnetic fields can describe the data.
Published: 2006

29. Optical SETI with Imaging Cherenkov Telescopes

Author: Holder, J., Ashworth, P., LeBohec, S., Rose, H. J., and Weekes, T. C.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astrophysics
Abstract: The idea of searching for optical signals from extraterrestrial civilizations has become increasingly popular over the last five years, with dedicated projects at a number of observatories. The method relies on the detection of a brief (few ns), intense light pulse with fast photon detectors. Ground-based gamma-ray telescopes such as the Whipple 10m, providing a large mirror area and equipped with an array of photomultiplier tubes (PMTs), are ideal instruments for this kind of observation if the background of cosmic-ray events can be rejected. We report here on a method for searching for optical SETI pulses, using background discrimination techniques based on the image shape., 4 pages. Submitted to the 29th ICRC, Pune
Published: 2005

30. VERITAS: the Very Energetic Radiation Imaging Telescope Array System

Author: Krennrich, F., Bond, I. H., Boyle, P. J., Bradbury, S. M., Buckley, J. H., Carter-Lewis, D., Celik, O., Cui, W., Daniel, M., D'Vali, M., Perez, I. D. C., Duke, C., Falcone, A., Fegan, D. J., Fegan, S. J., Finley, J. P., Fortson, L. F., Gaidos, J., Gammell, S., Gibbs, K., Gillanders, G. H., Grube, J., Hall, J., Hall, T. A., Hanna, D., Hillas, A. M., Holder, J., Horan, D., Jarvis, A., Kenny, G. E., Kertzman, M., Kieda, D., Kildea, J., Knapp, J., Kosack, K., Krawczynski, H., Lang, M. J., LeBohec, S., Linton, E., Lloyd-Evans, J., Milovanovic, A., Moriarty, P., Muller, D., Nagai, T., Nolan, S., Ong, R. A., Pallassini, R., Petry, D., Power-Mooney, B., Quinn, J., Quinn, M., Ragan, K., Rebillot, P., Reynolds, P. T., Rose, H. J., Schroedter, M., Sembroski, G., Swordy, S. P., Syson, A., Vassiliev, V. V., Walker, G., Wakely, S. P., Weekes, T. C., and Zweerink, J.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Astrophysics::Solar and Stellar Astrophysics, gamma-ray astronomy, tev energies, atmospheric cherenkov detectors, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: The Very Energetic Radiation Imaging Telescope Array System (VERITAS) is the major next generation imaging atmospheric Cherenkov gamma-ray telescope in the western hemisphere and will be located in southern Arizona nearby Kitt Peak National Observatory. The VERITAS observatory will provide unprecedented sensitivity to photon energies between 50 GeV and 50 TeV. The first stage is an array of four telescopes to be fully operational in early 2006, with an expansion to seven telescopes envisioned for 2008. The construction of a prototype telescope is underway, for which first light is expected in Fall 2003. The technical concept is outlined and a progress report is given. (C) 2004 Published by Elsevier B.V.
Published: 2004

31. Observation of M87 at 400 GeV with the Whipple 10 meter telescope

Author: Le Bohec, S., Badran, H. M., Bond, I. H., Boyle, P. J., Bradbury, S. M., Buckley, J. H., Carter-Lewis, D. A., Catanese, M., Celik, O., Cui, W., Daniel, M., D'Vali, M., Perez, I. D., Duke, C., Falcone, A., Fegan, D. J., Fegan, S. J., Finley, J. P., Fortson, L. F., Gaidos, J. A., Gammell, S., Gibbs, K., Gillanders, G. H., Grube, J., Hall, J., Hall, T. A., Hanna, D., Hillas, A. M., Holder, J., Horan, D., Jarvis, A., Jordan, M., Kenny, G. E., Kertzman, M., Kieda, D., Kildea, J., Knapp, J., Kosack, K., Krawczynski, H., Krennrich, F., Lang, M. J., Linton, E., Lloyd-Evans, J., Milovanovic, A., Moriarty, P., Muller, D., Nagai, T., Nolan, S., Ong, R. A., Pallassini, R., Petry, D., Rose, H. J., Schroedter, M., Sembroski, G. H., Swordy, S. P., Syson, A., Vassiliev, V. V., Wakely, S. P., Walker, G., Weekes, T. C., and Zweerink, J.
Subjects: galaxies : active, galaxies : individual (m87), gamma rays : observations, tev gamma-rays, bl-lacertae object, high-resolution, galaxy m-87, lac object, jet, emission, spectrum, radio, polarization, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Cosmology and Extragalactic Astrophysics
Abstract: We present results from observations taken with the Whipple 10 m very high energy gamma-ray telescope with maximal sensitivity at 400 GeV during 39 hr between 2000 and 2003 in the direction of the giant radio galaxy M87. Using the entire data set, we derive a 99% confidence level upper limit on the flux of gamma-ray emission above 400 GeV from M87 to be less than or equal to 6: 9; 10(-1)2 cm(-2) s(-1). This suggests variability at the 90% confidence level when compared to the flux measured by the HEGRA collaboration in 1999 if the differential spectrum is steeper than a power law of index 3.75. Our search for a correlation between the Rossi X-Ray Timing Explorer all-sky monitor observation and a potential gamma-ray signal is inconclusive.
Published: 2004

32. Discovery of Spectral Variability of Markarian 421 at TeV Energies

Author: Krennrich, F., Bond, I. H., Bradbury, S. M., Buckley, J. H., Carter-Lewis, D. A., Cui, W., Perez, I. de la Calle, Fegan, D. J., Fegan, S. J., Finley, J. P., Gaidos, J. A., Gibbs, K., Gillanders, G. H., Hall, T. A., Hillas, A. M., Holder, J., Horan, D., Jordan, M., Kertzman, M., Kieda, D., Kildea, J., Knapp, J., Kosack, K., Lang, M. J., LeBohec, S., Moriarty, P., M��ller, D., Ong, R. A., Pallassini, R., Petry, D., Quinn, J., Reay, N. W., Reynolds, P. T., Rose, H. J., Sembroski, G. H., Sidwell, R., Stanton, N., Swordy, S. P., Vassiliev, V. V., Wakely, S. P., and Weekes, T. C.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics
Abstract: The detection of spectral variability of the gamma-ray blazar Mrk 421 at TeV energies is reported. Observations with the Whipple Observatory 10m gamma-ray telescope taken in 2000/2001 revealed exceptionally strong and long-lasting flaring activity. Flaring levels of 0.4 to 13 times that of the Crab Nebula flux provided sufficient statistics for a detailed study of the energy spectrum between 380 GeV and 8.2 TeV as a function of flux level. These spectra are well described by a power law with an exponential cutoff. There is no evidence for variation in the cutoff energy with flux, and all spectra are consistent with an average value for the cutoff energy of 4.3 TeV. The spectral index varies between 1.89 in a high flux state and 2.72 in a low state. The correlation between spectral index and flux is tight when averaging over the total 2000/2001 data set. Spectral measurements of Mrk~421 from previous years (1995/96 and 1999) by the Whipple collaboration are consistent with this flux-spectral index correlation, which suggest that this may be a constant or a long-term property of the source. If a similar flux-spectral index correlation were found for other gamma-ray blazars, this universal property could help disentangle the intrinsic emission mechanism from external absorption effects., 24 pages, 3 figures, submitted May 20 2002, accepted for publication in the Astrophysical Journal Letters
Published: 2002

33. The TeV spectrum of H1426+428

Author: Petry, D., Bond, I. H., Bradbury, S. M., Buckley, J. H., Carter-Lewis, D. A., Cui, W., Duke, C., Perez, I. de la Calle, Falcone, A., Fegan, D. J., Fegan, S. J., Finley, J. P., Gaidos, J. A., Gibbs, K., Gammell, S., Hall, J., Hall, T. A., Hillas, A. M., Holder, J., Horan, D., Jordan, M., Kertzman, M., Kieda, D., Kildea, J., Knapp, J., Kosack, K., Krennrich, F., LeBohec, S., Moriarty, P., M��ller, D., Nagai, T. N., Ong, R., Page, M., Pallassini, R., Power-Mooney, B., Quinn, J., Reay, N. W., Reynolds, P. T., Rose, H. J., Schroedter, M., Sembroski, G. H., Sidwell, R., Stanton, N., Swordy, S. P., Vassiliev, V. V., Wakely, S. P., Walker, G., and Weekes, T. C.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), FOS: Physical sciences, High Energy Physics::Experiment, Astrophysics::Cosmology and Extragalactic Astrophysics
Abstract: The BL Lac object H1426+428 was recently detected as a high energy gamma-ray source by the VERITAS collaboration (Horan et al. 2002). We have reanalyzed the 2001 portion of the data used in the detection in order to examine the spectrum of H1426+428 above 250 GeV. We find that the time-averaged spectrum agrees with a power law of the shape dF/dE = 10^(-7.31 +- 0.15(stat) +- 0.16(syst)) x E^(-3.50 +- 0.35(stat) +- 0.05(syst)) m^(-2)s^(-1)TeV^(-1) The statistical evidence from our data for emission above 2.5 TeV is 2.6 sigma. With 95% c.l., the integral flux of H1426+428 above 2.5 TeV is larger than 3% of the corresponding flux from the Crab Nebula. The spectrum is consistent with the (non-contemporaneous) measurement by Aharonian et al. (2002) both in shape and in normalization. Below 800 GeV, the data clearly favours a spectrum steeper than that of any other TeV Blazar observed so far indicating a difference in the processes involved either at the source or in the intervening space., LaTeX, 8 pages, 4 figures, accepted for publication in ApJ
Published: 2002
Full Text: View/download PDF

34. Cutoff in the TeV Energy Spectrum of Markarian 421 During Strong Flares in 2001

Author: Krennrich, F., Badran, H. M., Bond, I. H., Bradbury, S. M., Buckley, J. H., Carter-Lewis, D. A., Catanese, M., Cui, W., Dunlea, S., Das, D., Perez, I. de la Calle, Fegan, D. J., Fegan, S. J., Finley, J. P., Gaidos, J. A., Gibbs, K., Gillanders, G. H., Hall, T. A., Hillas, A. M., Holder, J., Horan, D., Jordan, M., Kertzman, M., Kieda, D., Kildea, J., Knapp, J., Kosack, K., Lang, M. J., LeBohec, S., McKernan, B., Moriarty, P., M��ller, D., Ong, R., Pallassini, R., Petry, D., Quinn, J., Reay, N. W., Reynolds, P. T., Rose, H. J., Sembroski, G. H., Sidwell, R., Stanton, N., Swordy, S. P., Vassiliev, V. V., Wakely, S. P., and Weekes, T. C.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), FOS: Physical sciences, High Energy Physics::Experiment, Astrophysics
Abstract: Exceptionally strong and long lasting flaring activity of the blazar Markarian 421 (Mrk 421) occurred between January and March 2001. Based on the excellent signal-to-noise ratio of the data we derive the energy spectrum between 260 GeV - 17 TeV with unprecedented statistical precision. The spectrum is not well described by a simple power law even with a curvature term. Instead the data can be described by a power law with exponential cutoff: $\rm {{dN}\over{dE}} \propto \rm E^{-2.14 \pm 0.03_{stat}} \times e^{-E/E_{0}} m^{-2} s^{-1} TeV^{-1}$ with $\rm E_{0} = 4.3 \pm 0.3_{stat} TeV$. Mrk 421 is the second $\gamma$-ray blazar that unambiguously exhibits an absorption-like feature in its spectral energy distribution at 3-6 TeV suggesting that this may be a universal phenomenon, possibly due to the extragalactic infra-red background radiation., Comment: 14 pages, 3 figures, submitted to ApJL
Published: 2001

35. Gamma-ray Observations of the Galactic Plane at Energies E > 500 GeV

Author: Lebohec, S., Bond, I. H., Bradbury, S. M., Buckley, J. H., Burdett, A. M., Carter-Lewis, D. A., Catanese, M., Cawley, M. F., Dunlea, S., D Vali, M., Fegan, D. J., Fegan, S. J., Finley, J. P., Gaidos, J. A., Hall, T. A., Hillas, A. M., Horan, D., Knapp, J., Krennrich, F., Lessard, R. W., Macomb, D., Masterson, C., John Quinn, Rose, H. J., Samuelson, F. W., Sembroski, G. H., Vassiliev, V. V., and Weekes, T. C.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), FOS: Physical sciences, High Energy Physics::Experiment, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: In 1998 and 1999 the Whipple Observatory 10 m telescope was used to search for diffuse gamma ray emission from the Galactic Plane. No signifiant evidence of emission was found. Assuming the TeV emission profile matches EGRET observations above 1 GeV with a differential spectral index of 2.4, we derive an upper limit of {$\rm {3.0\cdot10^{-8}cm^{-2}s^{-1}sr^{-1}}$} for the average diffuse emission above {$\rm500 GeV$} in the galactic latitude range from {$\rm-2^o$ to $\rm +2^o$} at galactic longitude {$\rm 40^o$}. Comparisons with EGRET observations provide a lower limit of 2.31 for the differential spectral index of the diffuse emission, assuming there is no break in the spectrum between 30 GeV and 500 GeV. This constrains models for diffuse emission with a significant inverse Compton contribution., 18 pages, 9 figures, other comments
Published: 2000
Full Text: View/download PDF

36. VERITAS: Performance characteristics (baseline design)

Author: Vassiliev, V. V., Carter-Lewis, D. A., Hillas, A. M., Kertzman, M. P., Knapp, J., Krennrich, F., Lessard, R. W., Rose, H. J., and Sembroski, G. H.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astrophysics
Abstract: VERITAS is a proposed major ground-based gamma-ray observatory to be built at the Whipple Observatory in southern Arizona, USA. It will consist of an array of seven 10m imaging Cherenkov telescopes designed to conduct gamma-ray observations in the energy range of 50 GeV - 50 TeV. A description of the baseline VERITAS design and optimization criteria are presented. We provide basic characteristics of the array performance for observations of point sources, such as angular resolution, energy threshold, energy resolution, and integral flux sensitivity. The limiting factors of the VERITAS performance are discussed., to be published in the proceedings of the 26th ICRC (Salt Lake City, 1999)
Published: 1999

37. Hour-Scale Multiwavelength Variability in Markarian 421

Author: Catanese, M., Bond, I. H., Bradbury, S. M., Breslin, A. C., Buckley, J. H., Burdett, A. M., Carter-Lewis, D. A., Cawley, M. F., Dunlea, S., D'Vali, M., Fegan, D. J., Fegan, S. J., Finley, J. P., Gaidos, J. A., Hall, T. A., Hillas, A. M., Horan, D., Knapp, J., Krennrich, F., Bohec, S. Le, Lessard, R. W., Masterson, C., Moriarty, P., Quinn, J., Rose, H. J., Samuelson, F. W., Sembroski, G. H., Vassiliev, V. V., Weekes, T. C., Maraschi, L., Fossati, G., Tavecchio, F., Chiappetti, L., Celotti, A., Ghisellini, G., Grandi, P., Pian, E., Tagliaferri, G., and Treves, A.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics
Abstract: Markarian 421 was observed for about four days with BeppoSAX and the Whipple Observatory gamma-ray telescope in April 1998. A pronounced, well-defined, flare with hour-scale variability was observed simultaneously in X-rays and very high energy gamma-rays. These data provide the first evidence that the X-ray and TeV intensities are well correlated on time-scales of hours. While the rise of the flare occurred on a similar time-scale in the two wavebands, the decay of the flare was much more rapid in gamma rays, providing the first clear indication that the X-ray and gamma-ray emission may not be completely correlated in Markarian 421., 4 pages, 1 figure, to be published in the proceedings of the 26th ICRC (Salt Lake City, 1999)
Published: 1999

38. A Search for Pulsed TeV Gamma Ray Emission from the Crab Pulsar

Author: Lang, Mark, Gillanders, Gary, Burdett, A. M., Bond, I. H., Boyle, P. J., Bradbury, S. M., Buckley, J. H., Carter-Lewis, D. A., Catanese, M., Cawley, M. F., D'Vali, M., Fegan, D. J., Fegan, S. J., Finley, J. P., Gaidos, J. A., Gillanders, G. H., Hall, T. A., Hillas, A. M., Kildea, J., Knapp, J., Krennrich, F., Lang, M. J., LeBohec, S., Lessard, R. W., Masterson, C., Moriarty, P., Quinn, J., Rose, H. J., Samuelson, F. W., Sembroski, G. H., Srinivasan, R., Vassiliev, V. V., and Weekes, T. C.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Astrophysics
Abstract: We present the results of a search for pulsed TeV emission from the Crab pulsar using the Whipple Observatory's 10m gamma-ray telescope. The direction of the Crab pulsar was observed for a total of 73.4 hours between 1994 November and 1997 March. Spectral analysis techniques were applied to search for the presence of a gamma-ray signal from the Crab pulsar over the energy band 250GeV to 4TeV. At these energies we do not see any evidence of the 33ms pulsations present at lower energies from the Crab pulsar. The 99.9% confidence level upper limit for pulsed emission above 250GeV is derived to be 4.8 10^-12 cm^-2 s^-1 or
Published: 1999

39. A Search for Pulsed TeV Gamma Ray Emission from the Crab Pulsar

Author: Burdett, A. M., Bond, I. H., Boyle, P. J., Bradbury, S. M., Buckley, J. H., Carter-Lewis, D. A., Catanese, M., Cawley, M. F., D'Vali, M., Fegan, D. J., Fegan, S. J., Finley, J. P., Gaidos, J. A., Gillanders, G. H., Hall, T. A., Hillas, A. M., Kildea, J., Knapp, J., Krennrich, F., Lang, M. J., LeBohec, S., Lessard, R. W., Masterson, C., Moriarty, P., Quinn, J., Rose, H. J., Samuelson, F. W., Sembroski, G. H., Srinivasan, R., Vassiliev, V. V., and Weekes, T. C.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astrophysics
Abstract: We present the results of a search for pulsed TeV emission from the Crab pulsar using the Whipple Observatory's 10m gamma-ray telescope. The direction of the Crab pulsar was observed for a total of 73.4 hours between 1994 November and 1997 March. Spectral analysis techniques were applied to search for the presence of a gamma-ray signal from the Crab pulsar over the energy band 250GeV to 4TeV. At these energies we do not see any evidence of the 33ms pulsations present at lower energies from the Crab pulsar. The 99.9% confidence level upper limit for pulsed emission above 250GeV is derived to be 4.8 10^-12 cm^-2 s^-1 or, 4 pages, 2 figures, to be published in the proceedings of 26th International Cosmic Ray Conference (Salt Lake City, 1999)
Published: 1999
Full Text: View/download PDF

40. Search for TeV Gamma-Rays from Shell-Type Supernova Remnants

Author: Whipple Collaboration, Lessard, R. W., Bond, I. H., Boyle, P. J., Bradbury, S. M., Buckley, J. H., Burdett, A. M., Carter-Lewis, D. A., Catanese, M., Cawley, M. F., Dunlea, S., D'Vali, M., Fegan, D. J., Fegan, S. J., Finley, J. P., Gaidos, J. A., Hall, T. A., Hillas, A. M., Horan, D., Knapp, J., Krennrich, F., Bohec, S. Le, Masterson, C., Quinn, J., Rose, H. J., Samuelson, F. W., Sembroski, G. H., Vassiliev, V. V., and Weekes, T. C.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: If cosmic rays with energies 500 GeV flux are reported. Non-thermal X-ray emission detected from one of these remnants (Cassiopeia A) has been interpreted as synchrotron emission from electrons in the ambient magnetic fields. Gamma-ray emission detected from the Monoceros/Rosette Nebula region has been interpreted as evidence of cosmic-ray acceleration. We interpret our results in the context of these observations., 4 pages, 2 figures, to appear in the proceedings of 26th International Cosmic Ray Conference (Salt Lake City, 1999)
Published: 1999

41. Whipple Observations of BL Lac Objects

Author: D'Vali, M., Bond, I. H., Bradbury, S. M., Buckley, J. H., Burdett, A. M., Carter-Lewis, D. A., Catanese, M., Cawley, M. F., Fegan, D. J., Fegan, S. J., Finley, J. P., Gaidos, J. A., Hall, T. A., Hillas, A. M., Knapp, J., Krennrich, F., Bohec, S. Le, Lessard, R. W., Masterson, C., Myles, S. D., Quinn, J., Rose, H. J., Samuelson, F. W., Sembroski, G. H., Vassiliev, V. V., and Weekes, T. C.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: Only BL Lac objects have been detected as extragalactic sources of very high energy (E > 300 GeV) gamma rays. Using the Whipple Observatory Gamma-ray Telescope, we have attempted to detect more BL Lacs using three approaches. First, we have conducted surveys of nearby BL Lacs, which led to the detections of Mrk 501 and 1ES 2344+514. Second, we have observed X-ray bright BL Lacs when the RXTE All-Sky Monitor identifies high state X-ray emission in an object, in order to efficiently detect extended high emission states. Third, we have conducted rapid observations of several BL Lacs and QSOs located close together in the sky to search for very high flux, short time-scale flare states such as have been seen from Mrk 421. We will present the results of a survey using the third observational technique., 4 pages, 2 figures, to be published in the proceedings of 26th International Cosmic Ray Conference (Salt Lake City, 1999)
Published: 1999

42. The Very Energetic Radiation Imaging Telescope Array System (VERITAS)

Author: Bradbury, S. M., Bond, I. H., Breslin, A. C., Buckley, J. H., Carter-Lewis, D. A., Catanese, M., Criswell, S., Dingus, B. L., Fegan, D. J., Finley, J. P., Gaidos, J., Grindlay, J., Hillas, A. M., Harris, K., Hermann, G., Kaaret, P., Kieda, D., Knapp, J., Krennrich, F., LeBohec, S., Lessard, R. W., Lloyd-Evans, J., McKernan, B., Mueller, D., Ong, R., Quenby, J. J., Quinn, J., Rochester, G., Rose, H. J., Salamon, M., Sembroski, G. H., Sumner, T., Swordy, S., Vassiliev, V. V., and Weekes, T. C.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: We give an overview of the current status and scientific goals of VERITAS, a proposed hexagonal array of seven 10 m aperture imaging Cherenkov telescopes. The selected site is Montosa Canyon (1390 m a.s.l.) at the Whipple Observatory, Arizona. Each telescope, of 12 m focal length, will initially be equipped with a 499 element photomultiplier camera covering a 3.5 degree field of view. A central station will initiate the readout of 500 MHz FADCs upon receipt of multiple telescope triggers. The minimum detectable flux sensitivity will be 0.5% of the Crab Nebula flux at 200 GeV. Detailed simulations of the array's performance are presented elsewhere at this meeting. VERITAS will operate primarily as a gamma-ray observatory in the 50 GeV to 50 TeV range for the study of active galaxies, supernova remnants, pulsars and gamma-ray bursts., 4 pages, 2 figures, to be published in the proceedings of the 26th ICRC (Salt Lake City, 1999)
Published: 1999

43. New Limits to the IR Background: Bounds on Radiative Neutrino Decay and on VMO Contributions to the Dark Matter Problem

Author: Biller, S. D., Buckley, J., Burdett, A., Gordo, J. Bussons, Carter-Lewis, D. A., Fegan, D. J., Findley, J., Gaidos, J. A., Hillas, A. M., Krennrich, F., Lamb, R. C., Lessard, R., McEnery, J. E., Mohanty, G., Quinn, J., Rodgers, A. J., Rose, H. J., Samuelson, F., Sembroski, G., Skelton, P., Weekes, T. C., J, and Zweerink
Subjects: High Energy Physics - Experiment (hep-ex), High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), Physics - Space Physics, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Space Physics (physics.space-ph), Astrophysics::Galaxy Astrophysics, High Energy Physics - Experiment
Abstract: From considering the effect of gamma-gamma interactions on recently observed TeV gamma-ray spectra, improved limits are set to the density of extragalactic infrared (IR) photons which are robust and essentially model-independent. The resulting limits are up to two orders of magnitude more restrictive than direct observations in the 0.025-0.3eV regime. These limits are used to improve constraints on radiative neutrino decay in the mass range above 0.05eV and on Very Massive Objects (VMOs) as providing the dark matter needed to explain galaxy rotation curves., 13 pages including 4 figures
Published: 1998

44. Tev Blazars: Status of Observations

Author: Krennrich, F., Biller, S. D., Bond, I. H., Boyle, P. J., Bradbury, S. M., Breslin, A. C., Buckley, J. H., Burdett, A. M., Bussons Gordo, J., Carter-Lewis, D. A., Catanese, M., Cawley, M. F., Fegan, D. J., Finley, J. P., Gaidos, J. A., Hall, T., Hillas, A. M., Lamb, R. C., Lessard, R. W., Masterson, C., Mcenery, J. E., Mohanty, G., Moriarty, P., John Quinn, Rodgers, A. J., Rose, H. J., Samuelson, F. W., Sembroski, G. H., Srinivasan, R., Vassiliev, V. V., and Weekes, T. C.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, High Energy Physics::Phenomenology, Astrophysics (astro-ph), Physics::Accelerator Physics, FOS: Physical sciences, High Energy Physics::Experiment, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics
Abstract: The close relation between ground-based TeV observations and satellite borne $\gamma$-ray measurements has been important for the understanding of blazars. The observations which involve the TeV component in blazar studies are reviewed., Comment: 8 Pages, 6 figures
Published: 1998
Full Text: View/download PDF

45. Limits to Quantum Gravity Effects from Observations of TeV Flares in Active Galaxies

Author: Biller, S. D., Breslin, A. C., Buckley, J., Catanese, M., Carson, M., Carter-Lewis, D. A., Cawley, M. F., Fegan, D. J., Finley, J., Gaidos, J. A., Hillas, A. M., Krennrich, F., Lamb, R. C., Lessard, R., Masterson, C., McEnery, J. E., McKernan, B., Moriarty, P., Quinn, J., Rose, H. J., Samuelson, F., Sembroski, G., Skelton, P., and Weekes, T. C.
Subjects: High Energy Physics - Theory, High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), High Energy Physics - Theory (hep-th), Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), FOS: Physical sciences, General Relativity and Quantum Cosmology (gr-qc), Astrophysics, General Relativity and Quantum Cosmology
Abstract: We have used data from the TeV gamma-ray flare associated with the active galaxy Markarian 421 observed on 15 May 1996 to place bounds on the possible energy-dependence of the speed of light in the context of an effective quantum gravitational energy scale. The possibility of an observable time dispersion in high energy radiation has recently received attention in the literature, with some suggestions that the relevant energy scale could be less than the Planck mass and perhaps as low as 10^16 GeV. The limits derived here indicate this energy scale to be in excess of 4x10^16 GeV at the 95% confidence level. To the best of our knowledge, this constitutes the first convincing limit on such phenomena in this energy regime., Comment: 6 pages, including 2 figures
Published: 1998
Full Text: View/download PDF

46. Discovery of >350 GeV Gamma Rays from the BL Lacertae Object 1ES 2344+514

Author: Catanese, M., Akerlof, C. W., Badran, H. M., Biller, S. D., Bond, I. H., Boyle, P. J., Bradbury, S. M., Buckley, J. H., Burdett, A. M., Gordo, J. Bussons, Carter-Lewis, D. A., Cawley, M. F., Connaughton, V., Fegan, D. J., Finley, J. P., Gaidos, J. A., Hall, T., Hillas, A. M., Krennrich, F., Lamb, R. C., Lessard, R. W., Masterson, C., McEnery, J. E., Mohanty, G., Quinn, J., Rodgers, A. J., Rose, H. J., Samuelson, F. W., Schubnell, M. S., Sembroski, G. H., Srinivasan, R., Weekes, T. C., Wilson, C. W., and Zweerink, J.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: We present the discovery of >350 GeV gamma-ray emission from the BL Lacertae object 1ES 2344+514 with the Whipple Observatory 10m gamma-ray telescope. This is the third BL Lac object detected at gamma-ray energies above 300 Gev, the other two being Markarian 421 (Mrk 421) and Mrk501. These three active galactic nuclei are all X-ray selected and have the lowest known redshifts of any BL Lac objects currently identified. The evidence for emission derives primarily from an apparent flare on December 20, 1995 when a 6 sigma excess was detected with a flux approximately 63% of the very high energy gamma-ray emission from the Crab Nebula, the standard candle for TeV gamma-ray sources. Excluding the flare, observations between October 1995 and January 1996 yield a 4 sigma detection corresponding to 11% of the VHE Crab Nebula flux. Observations spanning September 1996 to January 1997 failed to yield a significant detection of a steady flux or any flaring. For this period, the 99.9% confidence level upper limit is, Comment: 19 pages, 6 Postscript figures
Published: 1997

47. The TeV Gamma-Ray Spectrum of Markarian 421 During an Intense Flare

Author: Zweerink, J. A., Akerlof, C. W., Biller, S. D., Boyle, P., Buckley, J. H., Burdett, A., Bussóns Gordo, J., Carter-Lewis, D. A., Catanese, M., Cawley, M. F., Fegan, D. J., Finley, J. P., Gaidos, J. A., Hillas, A. M., Krennrich, F., Lamb, R. C., Lessard, R. W., Mcenery, J. E., Mohanty, G., John Quinn, Rodgers, A. J., Rose, H. J., Samuelson, F. W., Schubnell, M. S., Sembroski, G., Srinivasan, R., Weekes, T. C., and Wilson, C.
Subjects: Astrophysics::High Energy Astrophysical Phenomena
Abstract: We present the gamma-ray spectrum of the BL Lacertae object, Markarian 421, above 500 GeV during its most intense recorded TeV flare, on 1996 May 7. The spectrum is well fitted by a power law with an exponent of 22.5650.0750.1 (statistical and systematic errors). The spectrum extends above 5 TeV with no evidence for a cutoff, favoring determinations of the extragalactic infrared energy density that do not produce a sharp cutoff at these energies.
Published: 1997

48. A Search for TeV Emission from Unidentified Sources in the Galactic Plane

Author: Buckley, J. H., Boyle, P. J., Bradbury, S. M., Burdett, A. M., Gordo, J. Bussons, Carter-Lewis, D. A., Catanese, M., Cawley, M. F., Fegan, D. J., Finley, J. P., Gaidos, J. A., Hillas, A. M., Krennrich, F., Lamb, R. C., Lessard, R. W., Masterson, C., McEnery, J. E., Mohanty, G., Quinn, J., Rodgers, A. J., Rose, H. J., Rovero, A. C., Samuelson, F. W., Sembroski, G. H., Srinivasan, R., Weekes, T. C., and Zweerink, J.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: The ~70 unidentified sources of the EGRET sky survey may be one of its most important legacies. The identification of these sources at other wavelengths is critical to understanding their nature. Many have flat spectra out to 10 GeV which, if extrapolated to TeV energies, would be easily detectable relative to the steeply falling diffuse background. The Whipple Observatory gamma-ray telescope has been used to observe a number of these which were selected based on their position, intensity and spectrum and in some cases based on a possible association with a supernova remnant or pulsar. No significant emission has been detected from these sources, and upper limits are given., 4 pages, 1 figure, to appear in proceedings of 25th ICRC (Durban)
Published: 1997

49. Spectrum of TeV Gamma-Rays from the Crab Nebula

Author: Carter-Lewis, D. A., Biller, S., Boyle, P. J., Buckley, J. H., Burdett, A., Gordo, J. Bussons, Catanese, M. A., Cawley, M. F., Fegan, D. J., Finley, J. P., Gaidos, J. A., Hillas, A. M., Krennrich, F., Lamb, R. C., Lessard, R. W., Masterson, C., McEnery, J. E., Mohanty, G., Quinn, J., Rodgers, A. J., Rose, H. J., Samuelson, F. W., Sembroski, G. H., Srinivasan, R., Weekes, T. C., West, M., and Zweerink, J. A.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astrophysics
Abstract: The Crab Nebula has become established as the standard candle for TeV gamma-ray astronomy using the atmospheric Cherenkov technique. No evidence for variability has been seen. The spectrum of gamma rays from the Crab Nebula has been measured in the energy range 500 GeV to 8 TeV at the Whipple Observatory by the atmospheric Cherenkov imaging technique. Two methods of analysis involving independent Monte Carlo simulations and two databases of observations (1988-89 and 1995-96) were used and gave close agreement. Using the complete spectrum of the Crab Nebula, the spectrum of relativistic electrons is deduced and the spectrum of the resulting inverse Compton gamma-ray emission is in good agreement with the measured spectrum if the ambient magnetic field is about 25-30 nT., 4 pages, 3 figures, to appear in proceedings of the 25th ICRC (Durban)
Published: 1997

50. Search for TeV Counterparts in Gamma-Ray Bursts

Author: Boyle, P. J., Buckley, J. H., Burdett, A. M., Gordo, J. Bussons, Carter-Lewis, D. A., Catanese, M., Cawley, M. F., Connaughton, V., Fegan, D. J., Finley, J. P., Gaidos, J. A., Harris, K., Hillas, A. M., Lamb, R. C., Krennrich, F., Lessard, R. W., Masterson, C., McEnery, J. E., Mohanty, G., Porter, N. A., Quinn, J., Rodgers, A. J., Rose, H. J., Samuelson, F. W., Sembroski, G. H., Srinivasan, R., Weekes, T. C., and Zweerink, J.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astrophysics
Abstract: Based on BACODINE network notification the Whipple Observatory gamma-ray telescope has been used to search for the delayed TeV counterpart to BATSE-detected gamma-ray bursts. In the fast slew mode, any point in the sky can be reached within two minutes of the burst notification. The search strategy, necessary because of the uncertainty in burst position and limited FOV of the camera, is described., 4 pages, 3 figures, to appear in proceedings of the 25th ICRC (Durban)
Published: 1997

Catalog

Books, media, physical & digital resources

See catalog results

Searchworks

Select search scope, currently: Articles Catalog books, media & more in Jio Institute collections Articles journal articles & other e-resources

Search

Search Constraints

Refine your results

Search Limiters

Topic

Publication Year Range

Language

Journal

Database

Publisher

62 results on '"Rose, H. A."'

Search Results

Catalog

Select search scope, currently: Articles

Catalog

books, media & more in Jio Institute collections

Articles

journal articles & other e-resources