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Actis, M. ; Agnetta, G. ; Aharonian, Felix A. ; Akhperjanian, A. G. ; Aleksic, J. ; Aliu, E. ; Allan, D. ; Allekotte, I. ; Antico, F. ; Antonelli, L. A. ; Antoranz, P. ; Aravantinos, A. ; Arlen, T. ; Arnaldi, H. ; Artmann, S. ; Asano, K. ; Asorey, H. G. ; Baehr, J. ; Bais, A. ; Baixeras, C. ; Bajtlik, S. ; Balis, D. ; Bamba, A. ; Barbier, C. ; Barcelo, M. ; Barnacka, Anna ; Barnstedt, Jürgen ; de Almeida, U. Barres ; Barrio, J. A. ; Basso, S. ; Bastieri, D. ; Bauer, C. ; Becerra Gonzalez, J. ; Becherini, Yvonne ; Bechtol, K. C. ; Becker, J. ; Beckmann, Volker ; Bednarek, W. ; Behera, B. ; Beilicke, M. ; Belluso, M. ; Benallou, M. ; Benbow, W. ; Berdugo, J. ; Berger, K. ; Bernardino, T. ; Bernlöhr, K. ; Biland, A. ; Billotta, S. ; Bird, T. ; Birsin, E. ; Bissaldi, E. ; Blake, S. ; Blanch Bigas, O. ; Bobkov, A. A. ; Bogacz, L. ; Bogdan, M. ; Boisson, Catherine ; Boix Gargallo, J. ; Bolmont, J. ; Bonanno, G. ; Bonardi, A. ; Bonev, T. ; Borkowski, Janett ; Botner, O. ; Bottani, A. ; Bourgeat, M. ; Boutonnet, C. ; Bouvier, A. ; Brau-Nogue, S. ; Braun, I. ; Bretz, T. ; Briggs, M. S. ; Brun, Pierre ; Brunetti, L. ; Buckley, H. ; Bugaev, V. ; Buehler, R. ; Bulik, Tomasz ; Busetto, G. ; Buson, S. ; Byrum, K. ; Cailles, M. ; Cameron, R. A. ; Canestrari, R. ; Cantu, S. ; Carmona, E. ; Carosi, A. ; Carr, John ; Carton, P. H. ; Casiraghi, M. ; Castarede, H. ; Catalano, O. ; Cavazzani, S. ; Cazaux, S. ; Cerruti, B. ; Cerruti, M. ; Chadwick, M. ; Chiang, J. ; Chikawa, M. ; Cieslar, M. ; Ciesielska, M. ; Cillis, A. N. ; Clerc, C. ; Colin, P. ; Colome, J. ; Compin, M. ; Conconi, P. ; Connaughton, V. ; Conrad, Jan ; Contreras, J. L. ; Coppi, P. ; Corlier, M. ; Corona, P. ; Corpace, O. ; Corti, D. ; Cortina, J. ; Costantini, H. ; Cotter, G. ; Courty, B. ; Couturier, S. ; Covino, S. ; Croston, J. ; Cusumano, G. ; Daniel, M. K. ; Dazzi, F. ; Deangelis, A. ; de Cea del Pozo, E. ; Dal Pino, E. M. de Gouveia ; de Jager, O. ; de la Calle Perez, I. ; De La Vega, G. ; De Lotto, B. ; de Naurois, M. ; Wilhelmi, E. de Ona ; de Souza, V. ; Decerprit, B. ; Deil, C. ; Delagnes, E. ; Deleglise, G. ; Delgado, C. ; Dettlaff, T. ; Di Paolo, A. ; Di Pierro, F. ; Diaz, C. ; Dick, J. ; Dickinson, H. ; Digel, S. W. ; Dimitrov, D. ; Disset, G. ; Djannati-Ataï, A. ; Doert, M. ; Domainko, W. ; Dorner, D. ; Doro, M. ; Dournaux, J. -L. ; Dravins, D. ; Drury, L. ; Dubois, F. ; Dubois, R. ; Dubus, G. ; Dufour, C. ; Durand, D. ; Dyks, J. ; Dyrda, M. ; Edy, E. ; Egberts, Kathrin ; Eleftheriadis, C. ; Elles, S. ; Emmanoulopoulos, D. ; Enomoto, R. ; Ernenwein, J. -P. ; Errando, M. ; Etchegoyen, A. ; Falcone, A. D. ; Farakos, K. ; Farnier, C. ; Federici, S. ; Feinstein, F. ; Ferenc, D. ; Fillin-Martino, E. ; Fink, D. ; Finley, C. ; Finley, J. P. ; Firpo, R. ; Florin, D. ; Foehr, C. ; Fokitis, E. ; Font, Ll. ; Fontaine, G. ; Fontana, A. ; Foerster, A. ; Fortson, L. ; Fouque, N. ; Fransson, C. ; Fraser, G. W. ; Fresnillo, L. ; Fruck, C. ; Fujita, Y. ; Fukazawa, Y. ; Funk, S. ; Gaebele, W. ; Gabici, S. ; Gadola, A. ; Galante, N. ; Gallant, Y. ; Garcia, B. ; Garcia Lopez, R. J. ; Garrido, D. ; Garrido, L. ; Gascon, D. ; Gasq, C. ; Gaug, M. ; Gaweda, J. ; Geffroy, N. ; Ghag, C. ; Ghedina, A. ; Ghigo, M. ; Gianakaki, E. ; Giarrusso, S. ; Giavitto, G. ; Giebels, B. ; Giro, E. ; Giubilato, P. ; Glanzman, T. ; Glicenstein, J. -F. ; Gochna, M. ; Golev, V. ; Gomez Berisso, M. ; Gonzalez, A. ; Gonzalez, F. ; Granena, F. ; Graciani, R. ; Granot, J. ; Gredig, R. ; Green, A. ; Greenshaw, T. ; Grimm, O. ; Grube, J. ; Grudzinska, M. ; Grygorczuk, J. ; Guarino, V. ; Guglielmi, L. ; Guilloux, F. ; Gunji, S. ; Gyuk, G. ; Hadasch, D. ; Haefner, D. ; Hagiwara, R. ; Hahn, J. ; Hallgren, A. ; Hara, S. ; Hardcastle, M. J. ; Hassan, T. ; Haubold, T. ; Hauser, M. ; Hayashida, M. ; Heller, R. ; Henri, G. ; Hermann, G. ; Herrero, A. ; Hinton, James Anthony ; Hoffmann, D. ; Hofmann, W. ; Hofverberg, P. ; Horns, D. ; Hrupec, D. ; Huan, H. ; Huber, B. ; Huet, J. -M. ; Hughes, G. ; Hultquist, K. ; Humensky, T. B. ; Huppert, J. -F. ; Ibarra, A. ; Illa, J. M. ; Ingjald, J. ; Inoue, S. ; Inoue, Y. ; Ioka, K. ; Jablonski, C. ; Jacholkowska, A. ; Janiak, M. ; Jean, P. ; Jensen, H. ; Jogler, T. ; Jung, I. ; Kaaret, P. ; Kabuki, S. ; Kakuwa, J. ; Kalkuhl, C. ; Kankanyan, R. ; Kapala, M. ; Karastergiou, A. ; Karczewski, M. ; Karkar, S. ; Karlsson, N. ; Kasperek, J. ; Katagiri, H. ; Katarzynski, K. ; Kawanaka, N. ; Kedziora, B. ; Kendziorra, E. ; Khelifi, B. ; Kieda, D. ; Kifune, T. ; Kihm, T. ; Klepser, S. ; Kluzniak, W. ; Knapp, J. ; Knappy, A. R. ; Kneiske, T. ; Knoedlseder, J. ; Koeck, F. ; Kodani, K. ; Kohri, K. ; Kokkotas, K. ; Komin, N. ; Konopelko, A. ; Kosack, K. ; Kossakowski, R. ; Kostka, P. ; Kotula, J. ; Kowal, G. ; Koziol, J. ; Kraehenbuehl, T. ; Krause, J. ; Krawczynski, H. ; Krennrich, F. ; Kretzschmann, A. ; Kubo, H. ; Kudryavtsev, V. A. ; Kushida, J. ; La Barbera, N. ; La Parola, V. ; La Rosa, G. ; Lopez, A. ; Lamanna, G. ; Laporte, P. ; Lavalley, C. ; Le Flour, T. ; Le Padellec, A. ; Lenain, J. -P. ; Lessio, L. ; Lieunard, B. ; Lindfors, E. ; Liolios, A. ; Lohse, T. ; Lombardi, S. ; Lopatin, A. ; Lorenz, E. ; Lubinski, P. ; Luz, O. ; Lyard, E. ; Maccarone, M. C. ; Maccarone, T. ; Maier, G. ; Majumdar, P. ; Maltezos, S. ; Malkiewicz, P. ; Mana, C. ; Manalaysay, A. ; Maneva, G. ; Mangano, A. ; Manigot, P. ; Marin, J. ; Mariotti, M. ; Markoff, S. ; Martinez, G. ; Martinez, M. ; Mastichiadis, A. ; Matsumoto, H. ; Mattiazzo, S. ; Mazin, D. ; McComb, T. J. L. ; McCubbin, N. ; McHardy, I. ; Medina, C. ; Melkumyan, D. ; Mendes, A. ; Mertsch, P. ; Meucci, M. ; Michalowski, J. ; Micolon, P. ; Mineo, T. ; Mirabal, N. ; Mirabel, F. ; Miranda, J. M. ; Mirzoyan, R. ; Mizuno, T. ; Moal, B. ; Moderski, R. ; Molinari, E. ; Monteiro, I. ; Moralejo, A. ; Morello, C. ; Mori, K. ; Motta, G. ; Mottez, F. ; Moulin, E. ; Mukherjee, R. ; Munar, P. ; Muraishi, H. ; Murase, K. ; Murphy, A. Stj. ; Nagataki, S. ; Naito, T. ; Nakamori, T. ; Nakayama, K. ; Naumann, C. L. ; Naumann, D. ; Nayman, P. ; Nedbal, D. ; Niedzwiecki, A. ; Niemiec, J. ; Nikolaidis, A. ; Nishijima, K. ; Nolan, S. J. ; Nowak, N. ; O'Brien, P. T. ; Ochoa, I. ; Ohira, Y. ; Ohishi, M. ; Ohka, H. ; Okumura, A. ; Olivetto, C. ; Ong, R. A. ; Orito, R. ; Orr, M. ; Osborne, J. P. ; Ostrowski, M. ; Otero, L. ; Otte, A. N. ; Ovcharov, E. ; Oya, I. ; Ozieblo, A. ; Paiano, S. ; Pallota, J. ; Panazol, J. L. ; Paneque, D. ; Panter, M. ; Paoletti, R. ; Papyan, G. ; Paredes, J. M. ; Pareschi, G. ; Parsons, R. D. ; Arribas, M. Paz ; Pedaletti, G. ; Pepato, A. ; Persic, M. ; Petrucci, P. O. ; Peyaud, B. ; Piechocki, W. ; Pita, S. ; Pivato, G. ; Platos, L. ; Platzer, R. ; Pogosyan, L. ; Pohl, Martin ; Pojmanski, G. ; Ponz, J. D. ; Potter, W. ; Prandini, E. ; Preece, R. ; Prokoph, H. ; Puehlhofer, G. ; Punch, M. ; Quel, E. ; Quirrenbach, A. ; Rajda, P. ; Rando, R. ; Rataj, M. ; Raue, M. ; Reimann, C. ; Reimann, O. ; Reimer, A. ; Reimer, O. ; Renaud, M. ; Renner, S. ; Reymond, J. -M. ; Rhode, W. ; Ribo, M. ; Ribordy, M. ; Rico, J. ; Rieger, F. ; Ringegni, P. ; Ripken, J. ; Ristori, P. ; Rivoire, S. ; Rob, L. ; Rodriguez, S. ; Roeser, U. ; Romano, Patrizia ; Romero, G. E. ; Rosier-Lees, S. ; Rovero, A. C. ; Roy, F. ; Royer, S. ; Rudak, B. ; Rulten, C. B. ; Ruppel, J. ; Russo, F. ; Ryde, F. ; Sacco, B. ; Saggion, A. ; Sahakian, V. ; Saito, K. ; Saito, T. ; Sakaki, N. ; Salazar, E. ; Salini, A. ; Sanchez, F. ; Sanchez Conde, M. A. ; Santangelo, A. ; Santos, E. M. ; Sanuy, A. ; Sapozhnikov, L. ; Sarkar, S. ; Scalzotto, V. ; Scapin, V. ; Scarcioffolo, M. ; Schanz, T. ; Schlenstedt, S. ; Schlickeiser, R. ; Schmidt, T. ; Schmoll, J. ; Schroedter, M. ; Schultz, C. ; Schultze, J. ; Schulz, A. ; Schwanke, U. ; Schwarzburg, S. ; Schweizer, T. ; Seiradakis, J. ; Selmane, S. ; Seweryn, K. ; Shayduk, M. ; Shellard, R. C. ; Shibata, T. ; Sikora, M. ; Silk, J. ; Sillanpaa, A. ; Sitarek, J. ; Skole, C. ; Smith, N. ; Sobczynska, D. ; Sofo Haro, M. ; Sol, H. ; Spanier, F. ; Spiga, D. ; Spyrou, S. ; Stamatescu, V. ; Stamerra, A. ; Starling, R. L. C. ; Stawarz, L. ; Steenkamp, R. ; Stegmann, Christian ; Steiner, S. ; Stergioulas, N. ; Sternberger, R. ; Stinzing, F. ; Stodulski, M. ; Straumann, U. ; Suarez, A. ; Suchenek, M. ; Sugawara, R. ; Sulanke, K. H. ; Sun, S. ; Supanitsky, A. D. ; Sutcliffe, P. ; Szanecki, M. ; Szepieniec, T. ; Szostek, A. ; Szymkowiak, A. ; Tagliaferri, G. ; Tajima, H. ; Takahashi, H. ; Takahashi, K. ; Takalo, L. ; Takami, H. ; Talbot, R. G. ; Tam, P. H. ; Tanaka, M. ; Tanimori, T. ; Tavani, M. ; Tavernet, J. -P. ; Tchernin, C. ; Tejedor, L. A. ; Telezhinsky, Igor O. ; Temnikov, P. ; Tenzer, C. ; Terada, Y. ; Terrier, R. ; Teshima, M. ; Testa, V. ; Tibaldo, L. ; Tibolla, O. ; Tluczykont, M. ; Peixoto, C. J. Todero ; Tokanai, F. ; Tokarz, M. ; Toma, K. ; Torres, D. F. ; Tosti, G. ; Totani, T. ; Toussenel, F. ; Vallania, P. ; Vallejo, G. ; van der Walt, J. ; van Eldik, C. ; Vandenbroucke, J. ; Vankov, H. ; Vasileiadis, G. ; Vassiliev, V. V. ; Vegas, I. ; Venter, L. ; Vercellone, S. ; Veyssiere, C. ; Vialle, J. P. ; Videla, M. ; Vincent, P. ; Vink, J. ; Vlahakis, N. ; Vlahos, L. ; Vogler, P. ; Vollhardt, A. ; Volpe, F. ; Von Gunten, H. P. ; Vorobiov, S. ; Wagner, S. ; Wagner, R. M. ; Wagner, B. ; Wakely, S. P. ; Walter, P. ; Walter, R. ; Warwick, R. ; Wawer, P. ; Wawrzaszek, R. ; Webb, N. ; Wegner, P. ; Weinstein, A. ; Weitzel, Q. ; Welsing, R. ; Wetteskind, H. ; White, R. ; Wierzcholska, A. ; Wilkinson, M. I. ; Williams, D. A. ; Winde, M. ; Wischnewski, R. ; Wisniewski, L. ; Wolczko, A. ; Wood, M. ; Xiong, Q. ; Yamamoto, T. ; Yamaoka, K. ; Yamazaki, R. ; Yanagita, S. ; Yoffo, B. ; Yonetani, M. ; Yoshida, A. ; Yoshida, T. ; Yoshikoshi, T. ; Zabalza, V. ; Zagdanski, A. ; Zajczyk, A. ; Zdziarski, A. ; Zech, Alraune ; Zietara, K. ; Ziolkowski, P. ; Zitelli, V. ; Zychowski, P.
Ground-based gamma-ray astronomy has had a major breakthrough with the impressive results obtained using systems of imaging atmospheric Cherenkov telescopes. Ground-based gamma-ray astronomy has a huge potential in astrophysics, particle physics and cosmology. CTA is an international initiative to build the next generation instrument, with a factor of 5-10 improvement in sensitivity in the 100 GeV-10 TeV range and the extension to energies well below 100 GeV and above 100 TeV. CTA will consist of two arrays (one in the north, one in the south) for full sky coverage and will be operated as open observatory. The design of CTA is based on currently available technology. This document reports on the status and presents the major design concepts of CTA.
The 2010 very high energy gamma-ray flare and 10 years ofmulti-wavelength oservations of M 87
(2012)
Abramowski, Attila ; Acero, F. ; Aharonian, Felix A. ; Akhperjanian, A. G. ; Anton, Gisela ; Balzer, Arnim ; Barnacka, Anna ; de Almeida, U. Barres ; Becherini, Yvonne ; Becker, J. ; Behera, B. ; Bernlöhr, K. ; Birsin, E. ; Biteau, Jonathan ; Bochow, A. ; Boisson, Catherine ; Bolmont, J. ; Bordas, Pol ; Brucker, J. ; Brun, Francois ; Brun, Pierre ; Bulik, Tomasz ; Buesching, I. ; Carrigan, Svenja ; Casanova, Sabrina ; Cerruti, M. ; Chadwick, Paula M. ; Charbonnier, A. ; Chaves, Ryan C. G. ; Cheesebrough, A. ; Clapson, A. C. ; Coignet, G. ; Cologna, Gabriele ; Conrad, Jan ; Dalton, M. ; Daniel, M. K. ; Davids, I. D. ; Degrange, B. ; Deil, C. ; Dickinson, H. J. ; Djannati-Ataï, A. ; Domainko, W. ; Drury, L. O'C. ; Dubus, G. ; Dutson, K. ; Dyks, J. ; Dyrda, M. ; Egberts, Kathrin ; Eger, P. ; Espigat, P. ; Fallon, L. ; Farnier, C. ; Fegan, S. ; Feinstein, F. ; Fernandes, M. V. ; Fiasson, A. ; Fontaine, G. ; Foerster, A. ; Fuessling, M. ; Gallant, Y. A. ; Gast, H. ; Gerard, L. ; Gerbig, D. ; Giebels, B. ; Glicenstein, J. F. ; Glueck, B. ; Goret, P. ; Goering, D. ; Haeffner, S. ; Hague, J. D. ; Hampf, D. ; Hauser, M. ; Heinz, S. ; Heinzelmann, G. ; Henri, G. ; Hermann, G. ; Hinton, James Anthony ; Hoffmann, A. ; Hofmann, W. ; Hofverberg, P. ; Holler, M. ; Horns, D. ; Jacholkowska, A. ; de Jager, O. C. ; Jahn, C. ; Jamrozy, M. ; Jung, I. ; Kastendieck, M. A. ; Katarzynski, K. ; Katz, U. ; Kaufmann, S. ; Keogh, D. ; Khangulyan, D. ; Khelifi, B. ; Klochkov, D. ; Kluzniak, W. ; Kneiske, T. ; Komin, Nu. ; Kosack, K. ; Kossakowski, R. ; Laffon, H. ; Lamanna, G. ; Lennarz, D. ; Lohse, T. ; Lopatin, A. ; Lu, C. -C. ; Marandon, V. ; Marcowith, A. ; Masbou, J. ; Maurin, D. ; Maxted, N. ; Mayer, M. ; McComb, T. J. L. ; Medina, M. C. ; Mehault, J. ; Moderski, R. ; Moulin, E. ; Naumann, C. L. ; Naumann-Godo, M. ; de Naurois, M. ; Nedbal, D. ; Nekrassov, D. ; Nguyen, N. ; Nicholas, B. ; Niemiec, J. ; Nolan, S. 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J. ; Ward, M. ; White, R. ; Wierzcholska, A. ; Zacharias, M. ; Zajczyk, A. ; Zdziarski, A. A. ; Zech, Alraune ; Zechlin, H. -S. ; Aleksic, J. ; Antonelli, L. A. ; Antoranz, P. ; Backes, Michael ; Barrio, J. A. ; Bastieri, D. ; Becerra Gonzalez, J. ; Bednarek, W. ; Berdyugin, A. ; Berger, K. ; Bernardini, E. ; Biland, A. ; Blanch Bigas, O. ; Bock, R. K. ; Boller, A. ; Bonnoli, G. ; Tridon, D. Borla ; Braun, I. ; Bretz, T. ; Canellas, A. ; Carmona, E. ; Carosi, A. ; Colin, P. ; Colombo, E. ; Contreras, J. L. ; Cortina, J. ; Cossio, L. ; Covino, S. ; Dazzi, F. ; De Angelis, A. ; De Cea del Pozo, E. ; De Lotto, B. ; Delgado Mendez, C. ; Diago Ortega, A. ; Doert, M. ; Dominguez, A. ; Prester, Dijana Dominis ; Dorner, D. ; Doro, M. ; Elsaesser, D. ; Ferenc, D. ; Fonseca, M. V. ; Font, L. ; Fruck, C. ; Garcia Lopez, R. J. ; Garczarczyk, M. ; Garrido, D. ; Giavitto, G. ; Godinovic, N. ; Hadasch, D. ; Haefner, D. ; Herrero, A. ; Hildebrand, D. ; Hoehne-Moench, D. ; Hose, J. ; Hrupec, D. ; Huber, B. ; Jogler, T. ; Klepser, S. ; Kraehenbuehl, T. ; Krause, J. ; La Barbera, A. ; Lelas, D. ; Leonardo, E. ; Lindfors, E. ; Lombardi, S. ; Lopez, M. ; Lorenz, E. ; Makariev, M. ; 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. ; Moralejo, A. ; Munar, P. ; Nieto, D. ; Nilsson, K. ; Orito, R. ; Oya, I. ; Paneque, D. ; Paoletti, R. ; Pardo, S. ; Paredes, J. M. ; Partini, S. ; Pasanen, M. ; Pauss, F. ; Perez-Torres, M. A. ; Persic, M. ; Peruzzo, L. ; Pilia, M. ; Pochon, J. ; Prada, F. ; Moroni, P. G. Prada ; Prandini, E. ; Puljak, I. ; Reichardt, I. ; Reinthal, R. ; Rhode, W. ; Ribo, M. ; Rico, J. ; Ruegamer, S. ; Saggion, A. ; Saito, K. ; Saito, T. Y. ; Salvati, M. ; Satalecka, K. ; Scalzotto, V. ; Scapin, V. ; Schultz, C. ; Schweizer, T. ; Shayduk, M. ; Shore, S. N. ; Sillanpaa, A. ; Sitarek, J. ; Sobczynska, D. ; Spanier, F. ; Spiro, S. ; Stamerra, A. ; Steinke, B. ; Storz, J. ; Strah, N. ; Suric, T. ; Takalo, L. ; Takami, H. ; Tavecchio, F. ; Temnikov, P. ; Terzic, T. ; Tescaro, D. ; Teshima, M. ; Thom, M. ; Tibolla, O. ; Torres, D. F. ; Treves, A. ; Vankov, H. ; Vogler, P. ; Wagner, R. M. ; Weitzel, Q. ; Zabalza, V. ; Zandanel, F. ; Zanin, R. ; Arlen, T. ; Aune, T. ; Beilicke, M. ; Benbow, W. ; Bouvier, A. ; Bradbury, S. M. ; Buckley, J. H. ; Bugaev, V. ; Byrum, K. ; Cannon, A. ; Cesarini, A. ; Ciupik, L. ; 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. ; Godambe, S. ; Griffin, S. ; Grube, J. ; Gyuk, G. ; Hanna, D. ; Holder, J. ; Huan, H. ; Hui, C. M. ; Kaaret, P. ; Karlsson, N. ; Kertzman, M. ; Khassen, Y. ; Kieda, D. ; Krawczynski, H. ; Krennrich, F. ; Lang, M. J. ; LeBohec, S. ; Maier, G. ; McArthur, S. ; McCann, A. ; Moriarty, P. ; Mukherjee, R. ; Nunez, P. D. ; Ong, R. A. ; Orr, M. ; Otte, A. N. ; Park, N. ; Perkins, J. S. ; Pichel, A. ; Pohl, Martin ; Prokoph, H. ; Ragan, K. ; Reyes, L. C. ; Reynolds, P. T. ; Roache, E. ; Rose, H. J. ; Ruppel, J. ; Schroedter, M. ; Sembroski, G. H. ; Sentuerk, G. D. ; Telezhinsky, Igor O. ; Tesic, G. ; Theiling, M. ; Thibadeau, S. ; Varlotta, A. ; Vassiliev, V. V. ; Vivier, M. ; Wakely, S. P. ; Weekes, T. C. ; Williams, D. A. ; Zitzer, B. ; de Almeida, U. Barres ; Cara, M. ; Casadio, C. ; Cheung, C. C. ; McConville, W. ; Davies, F. ; Doi, A. ; Giovannini, G. ; Giroletti, M. ; Hada, K. ; Hardee, P. ; Harris, D. E. ; Junor, W. ; Kino, M. ; Lee, N. P. ; Ly, C. ; Madrid, J. ; Massaro, F. ; Mundell, C. G. ; Nagai, H. ; Perlman, E. S. ; Steele, I. A. ; Walker, R. C. ; Wood, D. L.
The giant radio galaxy M 87 with its proximity (16 Mpc), famous jet, and very massive black hole ((3-6) x 10(9) M-circle dot) provides a unique opportunity to investigate the origin of very high energy (VHE; E > 100 GeV) gamma-ray emission generated in relativistic outflows and the surroundings of supermassive black holes. M 87 has been established as a VHE gamma-ray emitter since 2006. The VHE gamma-ray emission displays strong variability on timescales as short as a day. In this paper, results from a joint VHE monitoring campaign on M 87 by the MAGIC and VERITAS instruments in 2010 are reported. During the campaign, a flare at VHE was detected triggering further observations at VHE (H.E.S.S.), X-rays (Chandra), and radio (43 GHz Very Long Baseline Array, VLBA). The excellent sampling of the VHE gamma-ray light curve enables one to derive a precise temporal characterization of the flare: the single, isolated flare is well described by a two-sided exponential function with significantly different flux rise and decay times of tau(rise)(d) = (1.69 +/- 0.30) days and tau(decay)(d) = (0.611 +/- 0.080) days, respectively. While the overall variability pattern of the 2010 flare appears somewhat different from that of previous VHE flares in 2005 and 2008, they share very similar timescales (similar to day), peak fluxes (Phi(>0.35 TeV) similar or equal to (1-3) x 10(-11) photons cm(-2) s(-1)), and VHE spectra. VLBA radio observations of 43 GHz of the inner jet regions indicate no enhanced flux in 2010 in contrast to observations in 2008, where an increase of the radio flux of the innermost core regions coincided with a VHE flare. On the other hand, Chandra X-ray observations taken similar to 3 days after the peak of the VHE gamma-ray emission reveal an enhanced flux from the core (flux increased by factor similar to 2; variability timescale <2 days). The long-term (2001-2010) multi-wavelength (MWL) light curve of M 87, spanning from radio to VHE and including data from Hubble Space Telescope, Liverpool Telescope, Very Large Array, and European VLBI Network, is used to further investigate the origin of the VHE gamma-ray emission. No unique, common MWL signature of the three VHE flares has been identified. In the outer kiloparsec jet region, in particular in HST-1, no enhanced MWL activity was detected in 2008 and 2010, disfavoring it as the origin of the VHE flares during these years. Shortly after two of the three flares (2008 and 2010), the X-ray core was observed to be at a higher flux level than its characteristic range (determined from more than 60 monitoring observations: 2002-2009). In 2005, the strong flux dominance of HST-1 could have suppressed the detection of such a feature. Published models for VHE gamma-ray emission from M 87 are reviewed in the light of the new data.
Aliu, E. ; Archambault, S. ; Aune, T. ; Behera, B. ; Beilicke, M. ; Benbow, W. ; Berger, K. ; Bird, R. ; Bouvier, A. ; Buckley, J. H. ; Bugaev, V. ; Byrum, K. ; Cerruti, M. ; Chen, X. ; Ciupik, L. ; Connolly, M. P. ; Cui, W. ; Duke, C. ; Dumm, J. ; Errando, M. ; Falcone, A. ; Federici, S. ; Feng, Q. ; Finley, J. P. ; Fortin, P. ; Fortson, L. ; Furniss, A. ; Galante, N. ; Gillanders, G. H. ; Griffin, S. ; Griffiths, S. T. ; Grube, J. ; Gyuk, G. ; Hanna, D. ; Holder, J. ; Hughes, G. ; Humensky, T. B. ; Kaaret, P. ; Kertzman, M. ; Khassen, Y. ; Kieda, D. ; Krawczynski, H. ; Krennrich, F. ; Lang, M. J. ; Madhavan, A. S. ; Maier, G. ; Majumdar, P. ; McCann, A. ; Moriarty, P. ; Mukherjee, R. ; Nieto, D. ; Ong, R. A. ; Otte, A. N. ; Park, N. ; Perkins, J. S. ; Pohl, M. ; Popkow, A. ; Prokoph, H. ; Quinn, J. ; Ragan, K. ; Rajotte, J. ; Reyes, L. C. ; Reynolds, P. T. ; Richards, G. T. ; Roache, E. ; Rousselle, J. ; Sembroski, G. H. ; Sheidaei, F. ; Skole, C. ; Smith, A. W. ; Staszak, D. ; Stroh, M. ; Telezhinsky, Igor O. ; Theiling, M. ; Tucci, J. V. ; Tyler, J. ; Varlotta, A. ; Vincent, S. ; Wakely, S. P. ; Weinstein, A. ; Welsing, R. ; Williams, D. A. ; Zajczyk, A. ; Zitzer, B. ; Abramowski, Attila ; Aharonian, Felix A. ; Benkhali, Faical Ait ; Akhperjanian, A. G. ; Angüner, Ekrem Oǧuzhan ; Anton, Gisela ; Balenderan, Shangkari ; Balzer, Arnim ; Barnacka, Anna ; Becherini, Yvonne ; Tjus, J. Becker ; Bernlöhr, K. ; Birsin, E. ; Bissaldi, E. ; Biteau, Jonathan ; Boettcher, Markus ; Boisson, Catherine ; Bolmont, J. ; Bordas, Pol ; Brucker, J. ; Brun, Francois ; Brun, Pierre ; Bulik, Tomasz ; Carrigan, Svenja ; Casanova, Sabrina ; Cerruti, M. ; Chadwick, Paula M. ; Chalme-Calvet, R. ; Chaves, Ryan C. G. ; Cheesebrough, A. ; Chretien, M. ; Colafrancesco, Sergio ; Cologna, Gabriele ; Conrad, Jan ; Couturier, C. ; Dalton, M. ; Daniel, M. K. ; Davids, I. D. ; Degrange, B. ; Deil, C. ; deWilt, P. ; Dickinson, H. J. ; Djannati-Ataï, A. ; Domainko, W. ; Dubus, G. ; Dutson, K. ; Dyks, J. ; Dyrda, M. ; Edwards, T. ; Egberts, Kathrin ; Eger, P. ; Espigat, P. ; Farnier, C. ; Fegan, S. ; Feinstein, F. ; Fernandes, M. V. ; Fernandez, D. ; Fiasson, A. ; Fontaine, G. ; Foerster, A. ; Fuessling, M. ; Gajdus, M. ; Gallant, Y. A. ; Garrigoux, T. ; Giavitto, G. ; Giebels, B. ; Glicenstein, J. F. ; Grondin, M. -H. ; Grudzinska, M. ; Haeffner, S. ; Hahn, J. ; Harris, J. ; Heinzelmann, G. ; Henri, G. ; Hermann, G. ; Hervet, O. ; Hillert, A. ; Hinton, James Anthony ; Hofmann, W. ; Hofverberg, P. ; Holler, M. ; Horns, D. ; Jacholkowska, A. ; Jahn, C. ; Jamrozy, M. ; Janiak, M. ; Jankowsky, F. ; Jung, I. ; Kastendieck, M. A. ; Katarzynski, K. ; Katz, U. ; Kaufmann, S. ; Khelifi, B. ; Kieffer, M. ; Klepser, S. ; Klochkov, D. ; Kluzniak, W. ; Kneiske, T. ; Kolitzus, D. ; Komin, Nu. ; Kosack, K. ; Krakau, S. ; Krayzel, F. ; Krueger, P. P. ; Laffon, H. ; Lamanna, G. ; Lefaucheur, J. ; Lemiere, A. ; Lemoine-Goumard, M. ; Lenain, J. -P. ; Lennarz, D. ; Lohse, T. ; Lopatin, A. ; Lu, C. -C. ; Marandon, V. ; Marcowith, A. ; Marx, R. ; Maurin, G. ; Maxted, N. ; Mayer, M. ; McComb, T. J. L. ; Mehault, J. ; Menzler, U. ; Meyer, M. ; Moderski, R. ; Mohamed, M. ; Moulin, E. ; Murach, T. ; Naumann, C. L. ; de Naurois, M. ; Niemiec, J. ; Nolan, S. J. ; Oakes, L. ; Ohm, S. ; Wilhelmi, E. de Ona ; Opitz, B. ; Ostrowski, M. ; Oya, I. ; Panter, M. ; Parsons, R. D. ; Arribas, M. Paz ; Pekeur, N. W. ; Pelletier, G. ; Perez, J. ; Petrucci, P. -O. ; Peyaud, B. ; Pita, S. ; Poon, H. ; Puehlhofer, G. ; Punch, M. ; Quirrenbach, A. ; Raab, S. ; Raue, M. ; Reimer, A. ; Reimer, O. ; Renaud, M. ; de los Reyes, R. ; Rieger, F. ; Rob, L. ; Romoli, C. ; Rosier-Lees, S. ; Rowell, G. ; Rudak, B. ; Rulten, C. B. ; Sahakian, V. ; Sanchez, David M. ; Santangelo, A. ; Schlickeiser, R. ; Schuessler, F. ; Schulz, A. ; Schwanke, U. ; Schwarzburg, S. ; Schwemmer, S. ; Sol, H. ; Spengler, G. ; Spies, F. ; Stawarz, L. ; Steenkamp, R. ; Stegmann, Christian ; Stinzing, F. ; Stycz, K. ; Sushch, Iurii ; Szostek, A. ; Tavernet, J. -P. ; Tavernier, T. ; Taylor, A. M. ; Terrier, R. ; Tluczykont, M. ; Trichard, C. ; Valerius, K. ; van Eldik, C. ; Vasileiadis, G. ; Venter, C. ; Viana, A. ; Vincent, P. ; Voelk, H. J. ; Volpe, F. ; Vorster, M. ; Wagner, S. J. ; Wagner, P. ; Ward, M. ; Weidinger, M. ; Weitzel, Q. ; White, R. ; Wierzcholska, A. ; Willmann, P. ; Woernlein, A. ; Wouters, D. ; Zacharias, M. ; Zajczyk, A. ; Zdziarski, A. A. ; Zech, Alraune ; Zechlin, H. -S.
VERITAS and Fermi-LAT Observations of TeV Gamma-Ray Sources Discovered by HAWC in the 2HWC Catalog
(2018)
Abeysekara, A. U. ; Archer, A. ; Benbow, Wystan ; Bird, Ralph ; Brose, Robert ; Buchovecky, M. ; Buckley, J. H. ; Bugaev, V. ; Chromey, A. J. ; Connolly, M. P. ; Cui, Wei ; Daniel, M. K. ; Falcone, A. ; Feng, Qi ; Finley, John P. ; Fortson, L. ; Furniss, Amy ; Huetten, M. ; Hanna, David ; Hervet, O. ; Holder, J. ; Hughes, G. ; Humensky, T. B. ; Johnson, Caitlin A. ; Kaaret, Philip ; Kar, P. ; Kertzman, M. ; Kieda, David ; Krause, M. ; Krennrich, F. ; Kumar, S. ; Lang, M. J. ; Lin, T. T. Y. ; McArthur, S. ; Moriarty, P. ; Mukherjee, Reshmi ; Ong, R. A. ; Otte, Adam Nepomuk ; Park, Nahee ; Petrashyk, A. ; Pohl, Martin ; Pueschel, Elisa ; Quinn, J. ; Ragan, K. ; Reynolds, P. T. ; Richards, Gregory T. ; Roache, E. ; Rulten, C. ; Sadeh, I. ; Santander, Marcos ; Sembroski, G. H. ; Shahinyan, Karlen ; Sushch, I. ; Tyler, J. ; Wakely, S. P. ; Weinstein, A. ; Wells, R. M. ; Wilcox, P. ; Wilhelm, Alina ; Williams, D. A. ; Williamson, T. J. ; Zitzer, B. ; Abdollahi, S. ; Ajello, Marco ; Baldini, Luca ; Barbiellini, G. ; Bastieri, Denis ; Bellazzini, Ronaldo ; Berenji, B. ; Bissaldi, Elisabetta ; Blandford, R. D. ; Bonino, R. ; Bottacini, E. ; Brandt, Terri J. ; Bruel, P. ; Buehler, R. ; Cameron, R. A. ; Caputo, R. ; Caraveo, P. A. ; Castro, D. ; Cavazzuti, E. ; Charles, Eric ; Chiaro, G. ; Ciprini, S. ; Cohen-Tanugi, Johann ; Costantin, D. ; Cutini, S. ; de Palma, F. ; Di Lalla, N. ; Di Mauro, M. ; Di Venere, L. ; Dominguez, A. ; Favuzzi, C. ; Fegan, S. J. ; Franckowiak, Anna ; Fukazawa, Yasushi ; Funk, Stefan ; Fusco, Piergiorgio ; Gargano, Fabio ; Gasparrini, Dario ; Giglietto, Nicola ; Giordano, F. ; Giroletti, Marcello ; Green, D. ; Grenier, I. A. ; Guillemot, L. ; Guiriec, Sylvain ; Hays, Elizabeth ; Hewitt, John W. ; Horan, D. ; Johannesson, G. ; Kensei, S. ; Kuss, M. ; Larsson, Stefan ; Latronico, L. ; Lemoine-Goumard, Marianne ; Li, J. ; Longo, Francesco ; Loparco, Francesco ; Lovellette, M. N. ; Lubrano, Pasquale ; Magill, Jeffrey D. ; Maldera, Simone ; Mazziotta, Mario Nicola ; McEnery, J. E. ; Michelson, P. F. ; Mitthumsiri, W. ; Mizuno, Tsunefumi ; Monzani, Maria Elena ; Morselli, Aldo ; Moskalenko, Igor V. ; Negro, M. ; Nuss, E. ; Ojha, R. ; Omodei, Nicola ; Orienti, M. ; Orlando, E. ; Palatiello, M. ; Paliya, Vaidehi S. ; Paneque, D. ; Perkins, Jeremy S. ; Persic, M. ; Pesce-Rollins, Melissa ; Petrosian, Vahe' ; Piron, F. ; Porter, Troy A. ; Principe, G. ; Raino, S. ; Rando, Riccardo ; Rani, B. ; Razzano, Massimilano ; Razzaque, Soebur ; Reimer, A. ; Reimer, Olaf ; Reposeur, T. ; Sgro, C. ; Siskind, E. J. ; Spandre, Gloria ; Spinelli, P. ; Suson, D. J. ; Tajima, Hiroyasu ; Thayer, J. B. ; Thompson, David J. ; Torres, Diego F. ; Tosti, Gino ; Troja, Eleonora ; Valverde, J. ; Vianello, Giacomo ; Vogel, M. ; Wood, K. ; Yassine, M. ; Alfaro, R. ; Alvarez, C. ; Alvarez, J. D. ; Arceo, R. ; Arteaga-Velazquez, J. C. ; Rojas, D. Avila ; Ayala Solares, H. A. ; Becerril, A. ; Belmont-Moreno, E. ; BenZvi, S. Y. ; Bernal, A. ; Braun, J. ; Brisbois, C. ; Caballero-Mora, K. S. ; Capistran, T. ; Carraminana, A. ; Casanova, Sabrina ; Castillo, M. ; Cotti, U. ; Cotzomi, J. ; Coutino de Leon, S. ; De Leon, C. ; De la Fuente, E. ; Dichiara, S. ; Dingus, B. L. ; DuVernois, M. A. ; Diaz-Velez, J. C. ; Engel, K. ; Enriquez-Rivera, O. ; Fiorino, D. W. ; Fleischhack, H. ; Fraija, N. ; Garcia-Gonzalez, J. A. ; Garfias, F. ; Gonzalez Munoz, A. ; Gonzalez, M. M. ; Goodman, J. A. ; Hampel-Arias, Z. ; Harding, J. P. ; Hernandez, S. ; Hernandez-Almada, A. ; Hona, B. ; Hueyotl-Zahuantitla, F. ; Hui, C. M. ; Huntemeyer, P. ; Iriarte, A. ; Jardin-Blicq, A. ; Joshi, V. ; Kaufmann, S. ; Lara, A. ; Lauer, R. J. ; Lee, W. H. ; Lennarz, D. ; Leon Vargas, H. ; Linnemann, J. T. ; Longinotti, A. L. ; Luis-Raya, G. ; Luna-Garcia, R. ; Lopez-Coto, R. ; Malone, K. ; Marinelli, S. S. ; Martinez, O. ; Martinez-Castellanos, I. ; Martinez-Castro, J. ; Martinez-Huerta, H. ; Matthews, J. A. ; Miranda-Romagnoli, P. ; Moreno, E. ; Mostafa, M. ; Nayerhoda, A. ; Nellen, L. ; Newbold, M. ; Nisa, M. U. ; Noriega-Papaqui, R. ; Pelayo, R. ; Pretz, J. ; Perez-Perez, E. G. ; Ren, Z. ; Rho, C. D. ; Riviere, C. ; Rosa-Gonzalez, D. ; Rosenberg, M. ; Ruiz-Velasco, E. ; Salazar, H. ; Greus, F. Salesa ; Sandoval, A. ; Schneider, M. ; Arroyo, M. Seglar ; Sinnis, G. ; Smith, A. J. ; Springer, R. W. ; Surajbali, P. ; Taboada, Ignacio ; Tibolla, O. ; Tollefson, K. ; Torres, I. ; Ukwatta, Tilan N. ; Villasenor, L. ; Weisgarber, T. ; Westerhoff, Stefan ; Wisher, I. G. ; Wood, J. ; Yapici, Tolga ; Yodh, G. ; Zepeda, A. ; Zhou, H.
The High Altitude Water Cherenkov (HAWC) collaboration recently published their 2HWC catalog, listing 39 very high energy (VHE; >100 GeV) gamma-ray sources based on 507 days of observation. Among these, 19 sources are not associated with previously known teraelectronvolt (TeV) gamma-ray sources. We have studied 14 of these sources without known counterparts with VERITAS and Fermi-LAT. VERITAS detected weak gamma-ray emission in the 1 TeV-30 TeV band in the region of DA 495, a pulsar wind nebula coinciding with 2HWC J1953+294, confirming the discovery of the source by HAWC. We did not find any counterpart for the selected 14 new HAWC sources from our analysis of Fermi-LAT data for energies higher than 10 GeV. During the search, we detected gigaelectronvolt (GeV) gamma-ray emission coincident with a known TeV pulsar wind nebula, SNR G54.1+0.3 (VER J1930+188), and a 2HWC source, 2HWC J1930+188. The fluxes for isolated, steady sources in the 2HWC catalog are generally in good agreement with those measured by imaging atmospheric Cherenkov telescopes. However, the VERITAS fluxes for SNR G54.1+0.3, DA 495, and TeV J2032+4130 are lower than those measured by HAWC, and several new HAWC sources are not detected by VERITAS. This is likely due to a change in spectral shape, source extension, or the influence of diffuse emission in the source region.
Abeysekara, A. U. ; Benbow, Wystan ; Bird, Ralph ; Brill, A. ; Brose, Robert ; Buckley, J. H. ; Chromey, A. J. ; Daniel, M. K. ; Falcone, A. ; Finley, J. P. ; Fortson, L. ; Furniss, Amy ; Gent, A. ; Gillanders, Gerald H. ; Hanna, David ; Hassan, T. ; Hervet, O. ; Holder, J. ; Hughes, G. ; Humensky, T. B. ; Kaaret, Philip ; Kar, P. ; Kertzman, M. ; Kieda, David ; Krause, Maria ; Krennrich, F. ; Kumar, S. ; Lang, M. J. ; Lin, T. T. Y. ; Maier, Gernot ; Moriarty, P. ; Mukherjee, Reshmi ; Ong, R. A. ; Otte, Adam Nepomuk ; Park, Nahee ; Petrashyk, A. ; Pohl, Martin ; Pueschel, Elisa ; Quinn, J. ; Ragan, K. ; Richards, Gregory T. ; Roache, E. ; Sadeh, I. ; Santander, Marcos ; Schlenstedt, S. ; Sembroski, G. H. ; Sushch, Iurii ; Tyler, J. ; Vassiliev, V. V. ; Wakely, S. P. ; Weinstein, A. ; Wells, R. M. ; Wilcox, P. ; Wilhelm, Alina ; Williams, David A. ; Williamson, T. J. ; Zitzer, B. ; Acciari, V. A. ; Ansoldi, S. ; Antonelli, L. A. ; Engels, A. Arbet ; Baack, D. ; Babic, A. ; Banerjee, B. ; de Almeida, U. Barres ; Barrio, J. A. ; Becerra Gonzalez, Josefa ; Bednarek, Wlodek ; Bernardini, Elisa ; Berti, A. ; Besenrieder, J. ; Bhattacharyya, W. ; Bigongiari, C. ; Biland, A. ; Blanch, O. ; Bonnoli, G. ; Busetto, G. ; Carosi, R. ; Ceribella, G. ; Cikota, S. ; Colak, S. M. ; Colin, P. ; Colombo, E. ; Contreras, J. L. ; Cortina, J. ; Covino, S. ; Da Vela, P. ; Dazzi, F. ; De Angelis, A. ; De Lotto, B. ; Delfino, M. ; Delgado, J. ; Di Pierro, F. ; Do Souto Espinera, E. ; Dominguez, A. ; Prester, D. Dominis ; Dorner, D. ; Doro, M. ; Einecke, S. ; Elsaesser, D. ; Ramazani, V. Fallah ; Fattorini, A. ; Fernandez-Barral, A. ; Ferrara, G. ; Fidalgo, D. ; Foffano, L. ; Fonseca, M. V. ; Font, L. ; Fruck, C. ; Galindo, D. ; Gallozzi, S. ; Lopez, R. J. Garcia ; Garczarczyk, M. ; Gasparyan, S. ; Gaug, Markus ; Giammaria, P. ; Godinovic, N. ; Guberman, D. ; Hadasch, D. ; Hahn, A. ; Herrera, J. ; Hoang, J. ; Hrupec, D. ; Inoue, S. ; Ishio, K. ; Iwamura, Y. ; Kubo, H. ; Kushida, J. ; Kuvezdic, D. ; Lamastra, A. ; Lelas, D. ; Leone, Francesco ; Lindfors, E. ; Lombardi, S. ; Longo, Francesco ; Lopez, M. ; Lopez-Oramas, A. ; Machado de Oliveira Fraga, B. ; Maggio, C. ; Majumdar, P. ; Makariev, M. ; Mallamaci, M. ; Maneva, G. ; Manganaro, M. ; Mannheim, K. ; Maraschi, L. ; Mariotti, M. ; Martinez, M. ; Masuda, S. ; Mazin, D. ; Minev, M. ; Miranda, J. M. ; Mirzoyan, R. ; Molina, E. ; Moralejo, A. ; Moreno, V. ; Moretti, E. ; Munar-Adrover, Pere ; Neustroev, V. ; Niedzwiecki, Andrzej ; Rosillo, Mireia Nievas ; Nigro, C. ; Nilsson, Kari ; Ninci, D. ; Nishijima, K. ; Noda, K. ; Nogues, L. ; Noethe, M. ; Paiano, Simona ; Palacio, J. ; Paneque, D. ; Paoletti, R. ; Paredes, J. M. ; Pedaletti, G. ; Penil, P. ; Peresano, M. ; Persic, M. ; Moroni, P. G. Prada ; Prandini, E. ; Puljak, I. ; Garcia, J. R. ; Rhode, W. ; Ribo, Marc ; Rico, J. ; Righi, C. ; Rugliancich, A. ; Saha, Lab ; Sahakyan, Narek ; Saito, T. ; Satalecka, K. ; Schweizer, T. ; Sitarek, J. ; Snidaric, I. ; Sobczynska, D. ; Somero, A. ; Stamerra, A. ; Strzys, M. ; Suric, T. ; Tavecchio, Fabrizio ; Temnikov, P. ; Terzic, T. ; Teshima, M. ; Torres-Alba, N. ; Tsujimoto, S. ; van Scherpenberg, J. ; Vanzo, G. ; Vazquez Acosta, M. ; Vovk, I. ; Will, M. ; Zaric, D.
We report on observations of the pulsar/Be star binary system PSR J2032+4127/MT91 213 in the energy range between 100 GeV and 20 TeV with the Very Energetic Radiation Imaging Telescope Array and Major Atmospheric Gamma Imaging Cherenkov telescope arrays. The binary orbit has a period of approximately 50 years, with the most recent periastron occurring on 2017 November 13. Our observations span from 18 months prior to periastron to one month after. A new point-like gamma-ray source is detected, coincident with the location of PSR J2032+4127/MT91 213. The gamma-ray light curve and spectrum are well characterized over the periastron passage. The flux is variable over at least an order of magnitude, peaking at periastron, thus providing a firm association of the TeV source with the pulsar/Be star system. Observations prior to periastron show a cutoff in the spectrum at an energy around 0.5 TeV. This result adds a new member to the small population of known TeV binaries, and it identifies only the second source of this class in which the nature and properties of the compact object are firmly established. We compare the gamma-ray results with the light curve measured with the X-ray Telescope on board the Neil Gehrels Swift Observatory and with the predictions of recent theoretical models of the system. We conclude that significant revision of the models is required to explain the details of the emission that we have observed, and we discuss the relationship between the binary system and the overlapping steady extended source, TeV J2032+4130.
Abeysekara, A. U. ; Benbow, Wystan ; Bird, Ralph ; Brantseg, T. ; Brose, Robert ; Buchovecky, M. ; Buckley, J. H. ; Bugaev, V. ; Connolly, M. P. ; Cui, Wei ; Daniel, M. K. ; Falcone, A. ; Feng, Qi ; Finley, John P. ; Fortson, L. ; Furniss, Amy ; Gillanders, Gerard H. ; Gunawardhana, Isuru ; Huetten, M. ; Hanna, David ; Hervet, O. ; Holder, J. ; Hughes, G. ; Humensky, T. B. ; Johnson, Caitlin A. ; Kaaret, Philip ; Kar, P. ; Kertzman, M. ; Krennrich, F. ; Lang, M. J. ; Lin, T. T. Y. ; McArthur, S. ; Moriarty, P. ; Mukherjee, Reshmi ; Ong, R. A. ; Otte, Adam Nepomuk ; Park, N. ; Petrashyk, A. ; Pohl, Martin ; Pueschel, Elisa ; Quinn, J. ; Ragan, K. ; Reynolds, P. T. ; Richards, Gregory T. ; Roache, E. ; Rulten, C. ; Sadeh, I. ; Santander, M. ; Sembroski, G. H. ; Shahinyan, Karlen ; Wakely, S. P. ; Weinstein, A. ; Wells, R. M. ; Wilcox, P. ; Williams, D. A. ; Zitzer, B. ; Jorstad, Svetlana G. ; Marscher, Alan P. ; Lister, Matthew L. ; Kovalev, Yuri Y. ; Pushkarev, A. B. ; Savolainen, Tuomas ; Agudo, I. ; Molina, S. N. ; Gomez, J. L. ; Larionov, Valeri M. ; Borman, G. A. ; Mokrushina, A. A. ; Tornikoski, Merja ; Lahteenmaki, A. ; Chamani, W. ; Enestam, S. ; Kiehlmann, S. ; Hovatta, Talvikki ; Smith, P. S. ; Pontrelli, P.
Combined with measurements made by very-long-baseline interferometry, the observations of fast TeV gamma-ray flares probe the structure and emission mechanism of blazar jets. However, only a handful of such flares have been detected to date, and only within the last few years have these flares been observed from lower-frequency-peaked BL. Lac objects and flat-spectrum radio quasars. We report on a fast TeV gamma-ray flare from the blazar BL. Lacertae observed by the Very Energetic Radiation Imaging Telescope Array System (VERITAS). with a rise time of similar to 2.3 hr and a decay time of similar to 36 min. The peak flux above 200 GeV is (4.2 +/- 0.6) x 10(-6) photon m(-2) s(-1) measured with a 4-minute-binned light curve, corresponding to similar to 180% of the flux that is observed from the Crab Nebula above the same energy threshold. Variability contemporaneous with the TeV gamma-ray flare was observed in GeV gamma-ray, X-ray, and optical flux, as well as in optical and radio polarization. Additionally, a possible moving emission feature with superluminal apparent velocity was identified in Very Long Baseline Array observations at 43 GHz, potentially passing the radio core of the jet around the time of the gamma-ray flare. We discuss the constraints on the size, Lorentz factor, and location of the emitting region of the flare, and the interpretations with several theoretical models that invoke relativistic plasma passing stationary shocks.
Dark matter constraints from a joint analysis of dwarf Spheroidal galaxy observations with VERITAS
(2017)
Archambault, S. ; Archer, A. ; Benbow, W. ; Bird, R. ; Bourbeau, E. ; Brantseg, T. ; Buchovecky, M. ; Buckley, J. H. ; Bugaev, V. ; Byrum, K. ; Cerruti, M. ; Christiansen, J. L. ; Connolly, M. P. ; Cui, W. ; Daniel, M. K. ; Feng, Q. ; Finley, J. P. ; Fleischhack, H. ; Fortson, L. ; Furniss, A. ; Geringer-Sameth, A. ; Griffin, S. ; Grube, J. ; Hütten, M. ; Hakansson, N. ; Hanna, D. ; Hervet, O. ; Holder, J. ; Hughes, G. ; Hummensky, B. ; Johnson, C. A. ; Kaaret, P. ; Kar, P. ; Kelley-Hoskins, N. ; Kertzman, M. ; Kieda, D. ; Koushiappas, S. ; Krause, M. ; Krennrich, F. ; Lang, M. J. ; Lin, T. T. Y. ; McArthur, S. ; Moriarty, P. ; Mukherjee, R. ; Nieto, D. ; Ong, R. A. ; Otte, A. N. ; Park, N. ; Pohl, M. ; Popkow, A. ; Pueschel, Elisa ; Quinn, J. ; Ragan, K. ; Reynolds, P. T. ; Richards, G. T. ; Roache, E. ; Rulten, C. ; Sadeh, I. ; Santander, M. ; Sembroski, G. H. ; Shahinyan, K. ; Smith, A. W. ; Staszak, D. ; Telezhinsky, Igor O. ; Trepanier, S. ; Tucci, J. V. ; Tyler, J. ; Wakely, S. P. ; Weinstein, A. ; Wilcox, P. ; Williams, D. A. ; Zitzer, B.
We present constraints on the annihilation cross section of weakly interacting massive particles dark matter based on the joint statistical analysis of four dwarf galaxies with VERITAS. These results are derived from an optimized photon weighting statistical technique that improves on standard imaging atmospheric Cherenkov telescope (IACT) analyses by utilizing the spectral and spatial properties of individual photon events. We report on the results of similar to 230 hours of observations of five dwarf galaxies and the joint statistical analysis of four of the dwarf galaxies. We find no evidence of gamma-ray emission from any individual dwarf nor in the joint analysis. The derived upper limit on the dark matter annihilation cross section from the joint analysis is 1.35 x 10(-23) cm(3) s(-1) at 1 TeV for the bottom quark (b (b) over bar) final state, 2.85 x 10(-24) cm(3) s(-1) at 1 TeV for the tau lepton (tau+tau(-)) final state and 1.32 x 10-25 cm(3) s(-1) at 1 TeV for the gauge boson (gamma gamma) final state.
Allen, C. ; Archambault, S. ; Archer, A. ; Benbow, W. ; Bird, R. ; Bourbeau, E. ; Brose, Robert ; Buchovecky, M. ; Buckley, J. H. ; Bugaev, V. ; Cardenzana, J. V. ; Cerruti, M. ; Chen, Xuhui ; Christiansen, J. L. ; Connolly, M. P. ; Cui, W. ; Daniel, M. K. ; Eisch, J. D. ; Falcone, Abe ; Feng, Q. ; Fernandez-Alonso, M. ; Finley, J. P. ; Fleischhack, H. ; Flinders, A. ; Fortson, L. ; Furniss, A. ; Gillanders, G. H. ; Griffin, S. ; Grube, J. ; Huetten, M. ; Hakansson, N. ; Hanna, D. ; Hervet, O. ; Holder, J. ; Hughes, G. ; Humensky, T. B. ; Johnson, C. A. ; Kaaret, P. ; Kar, P. ; Kelley-Hoskins, N. ; Kertzman, M. ; Kieda, D. ; Krause, M. ; Krennrich, F. ; Kumar, S. ; Lang, M. J. ; Maier, G. ; McArthur, S. ; McCann, A. ; Meagher, K. ; Moriarty, P. ; Mukherjee, R. ; Nguyen, T. ; Nieto, D. ; Ong, R. A. ; Otte, A. N. ; Park, N. ; Petrashyk, A. ; Pichel, A. ; Pohl, Martin ; Popkow, A. ; Pueschel, Elisa ; Quinn, J. ; Ragan, K. ; Reynolds, P. T. ; Richards, G. T. ; Roache, E. ; Rovero, A. C. ; Rulten, C. ; Sadeh, I. ; Santander, Marcos ; Sembroski, G. H. ; Shahinyan, K. ; Telezhinsky, Igor O. ; Tucci, J. V. ; Tyler, J. ; Wakely, S. P. ; Weinstein, A. ; Wilhelm, Alina ; Williams, D. A.
We present very-high-energy gamma-ray observations of the BL Lac object 1ES 2344+514 taken by the Very Energetic Radiation Imaging Telescope Array System between 2007 and 2015. 1ES 2344+514 is detected with a statistical significance above the background of 20.8 sigma in 47.2 h (livetime) of observations, making this the most comprehensive very-high-energy study of 1ES 2344+514 to date. Using these observations, the temporal properties of 1ES 2344+514 are studied on short and long times-scales. We fit a constant-flux model to nightly and seasonally binned light curves and apply a fractional variability test to determine the stability of the source on different time-scales. We reject the constant-flux model for the 2007-2008 and 2014-2015 nightly binned light curves and for the long-term seasonally binned light curve at the > 3 sigma level. The spectra of the time-averaged emission before and after correction for attenuation by the extragalactic background light are obtained. The observed time-averaged spectrum above 200 GeV is satisfactorily fitted (x(2)/NDF = 7.89/6) by a power-law function with an index Gamma = 2.46 +/- 0.06(stat) +/- 0.20(sys) and extends to at least 8 TeV. The extragalactic-backgroundlight-deabsorbed spectrum is adequately fit (x(2)/NDF = 6.73/6) by a power-law function with an index Gamma = 2.15 +/- 0.06(stat) +/- 0.20(sys) while an F-test indicates that the power law with an exponential cut-off function provides a marginally better fit (x(2)/NDF = 2.56/5) at the 2.1 sigma level. The source location is found to be consistent with the published radio location and its spatial extent is consistent with a point source.
Abeysekara, A. U. ; Archer, A. ; Benbow, Wystan ; Bird, Ralph ; Brill, A. ; Brose, Robert ; Buckley, J. H. ; Christiansen, Jessie L. ; Chromey, A. J. ; Daniel, M. K. ; Falcone, A. ; Feng, Qi ; Finley, John P. ; Fortson, L. ; Furniss, Amy ; Gillanders, Gerard H. ; Gueta, O. ; Hanna, David ; Hervet, O. ; Holder, J. ; Hughes, G. ; Humensky, T. B. ; Johnson, Caitlin A. ; Kaaret, Philip ; Kar, P. ; Kelley-Hoskins, N. ; Kertzman, M. ; Kieda, David ; Krause, Maria ; Krennrich, F. ; Lang, M. J. ; Moriarty, P. ; Mukherjee, Reshmi ; Ong, R. A. ; Otte, A. N. ; Park, N. ; Petrashyk, A. ; Pohl, Martin ; Pueschel, Elisa ; Quinn, J. ; Ragan, K. ; Reynolds, P. T. ; Richards, Gregory T. ; Roache, E. ; Rulten, C. ; Sadeh, I. ; Santander, Marcos ; Scott, S. S. ; Sembroski, G. H. ; Shahinyan, Karlen ; Tyler, J. ; Wakely, S. P. ; Weinstein, A. ; Wells, R. M. ; Wilcox, P. ; Wilhelm, Alina ; Williams, D. A. ; Williamson, T. J. ; Zitzer, B. ; Kaur, A.
On 2017 September 22, the IceCube Neutrino Observatory reported the detection of the high-energy neutrino event IC 170922A, of potential astrophysical origin. It was soon determined that the neutrino direction was consistent with the location of the gamma-ray blazar TXS 0506+056. (3FGL J0509.4+ 0541), which was in an elevated gamma-ray emission state as measured by the Fermi satellite. Very Energetic Radiation Imaging Telescope Array System (VERITAS) observations of the neutrino/blazar region started on 2017 September 23 in response to the neutrino alert and continued through 2018 February 6. While no significant very-high-energy (VHE; E > 100 GeV) emission was observed from the blazar by VERITAS in the two-week period immediately following the IceCube alert, TXS 0506+ 056 was detected by VERITAS with a significance of 5.8 standard deviations (sigma) in the full 35 hr data set. The average photon flux of the source during this period was (8.9 +/- 1.6). x. 10(-12) cm(-2) s(-1), or 1.6% of the Crab Nebula flux, above an energy threshold of 110 GeV, with a soft spectral index of 4.8. +/-. 1.3.
Archambault, S. ; Archer, A. ; Benbow, W. ; Bird, Ralph ; Bourbeau, E. ; Bouvier, A. ; Buchovecky, M. ; Bugaev, V. ; Cardenzana, J. V. ; Cerruti, M. ; Ciupik, L. ; Connolly, M. P. ; Cui, W. ; Daniel, M. K. ; Errando, M. ; Falcone, A. ; Feng, Q. ; Finley, J. P. ; Fleischhack, H. ; Fortson, L. ; Furniss, A. ; Gillanders, G. H. ; Griffin, S. ; Hanna, D. ; Hervet, O. ; Holder, J. ; Hughes, G. ; Humensky, T. B. ; Hutten, M. ; Johnson, C. A. ; Kaaret, P. ; Kar, P. ; Kertzman, M. ; Kieda, D. ; Krause, M. ; Lang, M. J. ; Lin, T. T. Y. ; Maier, G. ; McArthur, S. ; Moriarty, P. ; Mukherjee, R. ; Nieto, D. ; Ong, R. A. ; Otte, A. N. ; Park, N. ; Pohl, Martin ; Popkow, A. ; Pueschel, Elisa ; Quinn, J. ; Ragan, K. ; Reynolds, P. T. ; Richards, G. T. ; Roache, E. ; Rulten, C. ; Sadeh, I. ; Sembroski, G. H. ; Shahinyan, K. ; Staszak, D. ; Telezhinsky, Igor O. ; Trepanier, S. ; Wakely, S. P. ; Weinstein, A. ; Wilcox, P. ; Williams, D. A. ; Zitzer, B.
Imaging atmospheric Cherenkov telescopes (IACTs) are equipped with sensitive photomultiplier tube (PMT) cameras. Exposure to high levels of background illumination degrades the efficiency of and potentially destroys these photo-detectors over time, so IACTs cannot be operated in the same configuration in the presence of bright moonlight as under dark skies. Since September 2012, observations have been carried out with the VERITAS IACTs under bright moonlight (defined as about three times the night-sky-background (NSB) of a dark extragalactic field, typically occurring when Moon illumination > 35%) in two observing modes, firstly by reducing the voltage applied to the PMTs and, secondly, with the addition of ultra-violet (UV) bandpass filters to the cameras. This has allowed observations at up to about 30 times previous NSB levels (around 80% Moon illumination), resulting in 30% more observing time between the two modes over the course of a year. These additional observations have already allowed for the detection of a flare from the 1ES 1727 + 502 and for an observing program targeting a measurement of the cosmic-ray positron fraction. We provide details of these new observing modes and their performance relative to the standard VERITAS observations. (C) 2017 Elsevier B.V. All rights reserved.