@article{AbdoAckermannAjelloetal.2011, author = {Abdo, A. A. and Ackermann, Margit and Ajello, M. and Allafort, A. J. and Baldini, L. and Ballet, J. and Barbiellini, G. and Baring, M. G. and Bastieri, D. and Bechtol, K. C. and Bellazzini, R. and Berenji, B. and Blandford, R. D. and Bloom, E. D. and Bonamente, E. and Borgland, A. W. and Bouvier, A. and Brandt, T. J. and Bregeon, Johan and Brez, A. and Brigida, M. and Bruel, P. and Buehler, R. and Buson, S. and Caliandro, G. A. and Cameron, R. A. and Cannon, A. and Caraveo, P. A. and Carrigan, Svenja and Casandjian, J. M. and Cavazzuti, E. and Cecchi, C. and Celik, O. and Charles, E. and Chekhtman, A. and Cheung, C. C. and Chiang, J. and Ciprini, S. and Claus, R. and Cohen-Tanugi, J. and Conrad, Jan and Cutini, S. and Dermer, C. D. and de Palma, F. and do Couto e Silva, E. and Drell, P. S. and Dubois, R. and Dumora, D. and Favuzzi, C. and Fegan, S. J. and Ferrara, E. C. and Focke, W. B. and Fortin, P. and Frailis, M. and Fuhrmann, L. and Fukazawa, Y. and Funk, S. and Fusco, P. and Gargano, F. and Gasparrini, D. and Gehrels, N. and Germani, S. and Giglietto, N. and Giordano, F. and Giroletti, M. and Glanzman, T. and Godfrey, G. and Grenier, I. A. and Guillemot, L. and Guiriec, S. and Hayashida, M. and Hays, E. and Horan, D. and Hughes, R. E. and Johannesson, G. and Johnson, A. S. and Johnson, W. N. and Kadler, M. and Kamae, T. and Katagiri, H. and Kataoka, J. and Knoedlseder, J. and Kuss, M. and Lande, J. and Latronico, L. and Lee, S. -H. and Lemoine-Goumard, M. and Longo, F. and Loparco, F. and Lott, B. and Lovellette, M. N. and Lubrano, P. and Madejski, G. M. and Makeev, A. and Max-Moerbeck, W. and Mazziotta, Mario Nicola and McEnery, J. E. and Mehault, J. and Michelson, P. F. and Mitthumsiri, W. and Mizuno, T. and Moiseev, A. A. and Monte, C. and Monzani, M. E. and Morselli, A. and Moskalenko, I. V. and Murgia, S. and Naumann-Godo, M. and Nishino, S. and Nolan, P. L. and Norris, J. P. and Nuss, E. and Ohsugi, T. and Okumura, A. and Omodei, N. and Orlando, E. and Ormes, J. F. and Paneque, D. and Panetta, J. H. and Parent, D. and Pavlidou, V. and Pearson, T. J. and Pelassa, V. and Pepe, M. and Pesce-Rollins, M. and Piron, F. and Porter, T. A. and Raino, S. and Rando, R. and Razzano, M. and Readhead, A. and Reimer, A. and Reimer, O. and Richards, J. L. and Ripken, J. and Ritz, S. and Roth, M. and Sadrozinski, H. F. -W. and Sanchez, D. and Sander, A. and Scargle, J. D. and Sgro, C. and Siskind, E. J. and Smith, P. D. and Spandre, G. and Spinelli, P. and Stawarz, L. and Stevenson, M. and Strickman, M. S. and Sokolovsky, K. V. and Suson, D. J. and Takahashi, H. and Takahashi, T. and Tanaka, T. and Thayer, J. B. and Thayer, J. G. and Thompson, D. J. and Tibaldo, L. and Torres, F. and Tosti, G. and Tramacere, A. and Uchiyama, Y. and Usher, T. L. and Vandenbroucke, J. and Vasileiou, V. and Vilchez, N. and Vitale, V. and Waite, A. P. and Wang, P. and Wehrle, A. E. and Winer, B. L. and Wood, K. S. and Yang, Z. and Ylinen, T. and Zensus, J. A. and Ziegler, M. and Aleksic, J. and Antonelli, L. A. and Antoranz, P. and Backes, Michael and Barrio, J. A. and Gonzalez, J. Becerra and Bednarek, W. and Berdyugin, A. and Berger, K. and Bernardini, E. and Biland, A. and Blanch Bigas, O. and Bock, R. K. and Boller, A. and Bonnoli, G. and Bordas, Pol and Tridon, D. Borla and Bosch-Ramon, Valentin and Bose, D. and Braun, I. and Bretz, T. and Camara, M. and Carmona, E. and Carosi, A. and Colin, P. and Colombo, E. and Contreras, J. L. and Cortina, J. and Covino, S. and Dazzi, F. and de Angelis, A. and del Pozo, E. De Cea and De Lotto, B. and De Maria, M. and De Sabata, F. and Mendez, C. Delgado and Ortega, A. Diago and Doert, M. and Dominguez, A. and Prester, Dijana Dominis and Dorner, D. and Doro, M. and Elsaesser, D. and Ferenc, D. and Fonseca, M. V. and Font, L. and Lopen, R. J. Garcia and Garczarczyk, M. and Gaug, M. and Giavitto, G. and Godinovi, N. and Hadasch, D. and Herrero, A. and Hildebrand, D. and Hoehne-Moench, D. and Hose, J. and Hrupec, D. and Jogler, T. and Klepser, S. and Kraehenbuehl, T. and Kranich, D. and Krause, J. and La Barbera, A. and Leonardo, E. and Lindfors, E. and Lombardi, S. and Lopez, M. and Lorenz, E. and Majumdar, P. and Makariev, E. and Maneva, G. and Mankuzhiyil, N. and Mannheim, K. and Maraschi, L. and Mariotti, M. and Martinez, M. and Mazin, D. and Meucci, M. and Miranda, J. M. and Mirzoyan, R. and Miyamoto, H. and Moldon, J. and Moralejo, A. and Nieto, D. and Nilsson, K. and Orito, R. and Oya, I. and Paoletti, R. and Paredes, J. M. and Partini, S. and Pasanen, M. and Pauss, F. and Pegna, R. G. and Perez-Torres, M. A. and Persic, M. and Peruzzo, J. and Pochon, J. and Moroni, P. G. Prada and Prada, F. and Prandini, E. and Puchades, N. and Puljak, I. and Reichardt, T. and Reinthal, R. and Rhode, W. and Ribo, M. and Rico, J. and Rissi, M. and Ruegamer, S. and Saggion, A. and Saito, K. and Saito, T. Y. and Salvati, M. and Sanchez-Conde, M. and Satalecka, K. and Scalzotto, V. and Scapin, V. and Schultz, C. and Schweizer, T. and Shayduk, M. and Shore, S. N. and Sierpowska-Bartosik, A. and Sillanpaa, A. and Sitarek, J. and Sobczynska, D. and Spanier, F. and Spiro, S. and Stamerra, A. and Steinke, B. and Storz, J. and Strah, N. and Struebig, J. C. and Suric, T. and Takalo, L. O. and Tavecchio, F. and Temnikov, P. and Terzic, T. and Tescaro, D. and Teshima, M. and Vankov, H. and Wagner, R. M. and Weitzel, Q. and Zabalza, V. and Zandanel, F. and Zanin, R. and Acciari, V. A. and Arlen, T. and Aune, T. and Benbow, W. and Boltuch, D. and Bradbury, S. M. and Buckley, J. H. and Bugaev, V. and Cannon, A. and Cesarini, A. and Ciupik, L. and Cui, W. and Dickherber, R. and Errando, M. and Falcone, A. and Finley, J. P. and Finnegan, G. and Fortson, L. and Furniss, A. and Galante, N. and Gall, D. and Gillanders, G. H. and Godambe, S. and Grube, J. and Guenette, R. and Gyuk, G. and Hanna, D. and Holder, J. and Huang, D. and Hui, C. M. and Humensky, T. B. and Kaaret, P. and Karlsson, N. and Kertzman, M. and Kieda, D. and Konopelko, A. and Krawczynski, H. and Krennrich, F. and Lang, M. J. and Maier, G. and McArthur, S. and McCann, A. and McCutcheon, M. and Moriarty, P. and Mukherjee, R. and Ong, R. and Otte, N. and Pandel, D. and Perkins, J. S. and Pichel, A. and Pohl, M. and Quinn, J. and Ragan, K. and Reyes, L. C. and Reynolds, P. T. and Roache, E. and Rose, H. J. and Rovero, A. C. and Schroedter, M. and Sembroski, G. H. and Senturk, G. D. and Steele, D. and Swordy, S. P. and Tesic, G. and Theiling, M. and Thibadeau, S. and Varlotta, A. and Vincent, S. and Wakely, S. P. and Ward, J. E. and Weekes, T. C. and Weinstein, A. and Weisgarber, T. and Williams, D. A. and Wood, M. and Zitzer, B. and Villata, M. and Raiteri, C. M. and Aller, H. D. and Aller, M. F. and Arkharov, A. A. and Blinov, D. A. and Calcidese, P. and Chen, W. P. and Efimova, N. V. and Kimeridze, G. and Konstantinova, T. S. and Kopatskaya, E. N. and Koptelova, E. and Kurtanidze, O. M. and Kurtanidze, S. O. and Lahteenmaki, A. and Larionov, V. M. and Larionova, E. G. and Larionova, L. V. and Ligustri, R. and Morozova, D. A. and Nikolashvili, M. G. and Sigua, L. A. and Troitsky, I. S. and Angelakis, E. and Capalbi, M. and Carraminana, A. and Carrasco, L. and Cassaro, P. and de la Fuente, E. and Gurwell, M. A. and Kovalev, Y. Y. and Kovalev, Yu. A. and Krichbaum, T. P. and Krimm, H. A. and Leto, Paolo and Lister, M. L. and Maccaferri, G. and Moody, J. W. and Mori, Y. and Nestoras, I. and Orlati, A. and Pagani, C. and Pace, C. and Pearson, R. and Perri, M. and Piner, B. G. and Pushkarev, A. B. and Ros, E. and Sadun, A. C. and Sakamoto, T. and Tornikoski, M. and Yatsu, Y. and Zook, A.}, title = {Insights into the high-energy gamma-Ray emission of markarian 501 fromextensive multifrequency observations in the fermi era}, series = {The astrophysical journal : an international review of spectroscopy and astronomical physics}, volume = {727}, journal = {The astrophysical journal : an international review of spectroscopy and astronomical physics}, number = {2}, publisher = {IOP Publ. Ltd.}, address = {Bristol}, organization = {Fermi-LAT Collaboration, MAGIC Collaboration, VERITAS Collaboration}, issn = {0004-637X}, doi = {10.1088/0004-637X/727/2/129}, pages = {26}, year = {2011}, abstract = {We report on the gamma-ray activity of the blazar Mrk 501 during the first 480 days of Fermi operation. We find that the average Large Area Telescope (LAT) gamma-ray spectrum of Mrk 501 can be well described by a single power-law function with a photon index of 1.78 +/- 0.03. While we observe relatively mild flux variations with the Fermi-LAT (within less than a factor of two), we detect remarkable spectral variability where the hardest observed spectral index within the LAT energy range is 1.52 +/- 0.14, and the softest one is 2.51 +/- 0.20. These unexpected spectral changes do not correlate with the measured flux variations above 0.3 GeV. In this paper, we also present the first results from the 4.5 month long multifrequency campaign (2009 March 15-August 1) on Mrk 501, which included the Very Long Baseline Array (VLBA), Swift, RXTE, MAGIC, and VERITAS, the F-GAMMA, GASP-WEBT, and other collaborations and instruments which provided excellent temporal and energy coverage of the source throughout the entire campaign. The extensive radio to TeV data set from this campaign provides us with the most detailed spectral energy distribution yet collected for this source during its relatively low activity. The average spectral energy distribution of Mrk 501 is well described by the standard one-zone synchrotron self-Compton (SSC) model. In the framework of this model, we find that the dominant emission region is characterized by a size less than or similar to 0.1 pc (comparable within a factor of few to the size of the partially resolved VLBA core at 15-43 GHz), and that the total jet power (similar or equal to 10(44) erg s(-1)) constitutes only a small fraction (similar to 10(-3)) of the Eddington luminosity. The energy distribution of the freshly accelerated radiating electrons required to fit the time-averaged data has a broken power-law form in the energy range 0.3 GeV-10 TeV, with spectral indices 2.2 and 2.7 below and above the break energy of 20 GeV. We argue that such a form is consistent with a scenario in which the bulk of the energy dissipation within the dominant emission zone of Mrk 501 is due to relativistic, proton-mediated shocks. We find that the ultrarelativistic electrons and mildly relativistic protons within the blazar zone, if comparable in number, are in approximate energy equipartition, with their energy dominating the jet magnetic field energy by about two orders of magnitude.}, language = {en} } @article{AbramowskiAharonianBenkhalietal.2015, author = {Abramowski, Attila and Aharonian, Felix A. and Benkhali, Faical Ait and Akhperjanian, A. G. and Ang{\"u}ner, Ekrem Oǧuzhan and Backes, Michael and Balenderan, Shangkari and Balzer, Arnim and Barnacka, Anna and Becherini, Yvonne and Tjus, J. Becker and Berge, David and Bernhard, Sabrina and Bernl{\"o}hr, K. and Birsin, E. and Biteau, Jonathan and Boettcher, Markus and Boisson, Catherine and Bolmont, J. and Bordas, Pol and Bregeon, Johan and Brun, Francois and Brun, Pierre and Bryan, Mark and Bulik, Tomasz and Carrigan, Svenja and Casanova, Sabrina and Chadwick, Paula M. and Chatraborty, N. and Chalme-Calvet, R. and Chaves, Ryan C. G. and Chretien, M. and Colafrancesco, Sergio and Cologna, Gabriele and Conrad, Jan and Couturier, C. and Cui, Y. and Davids, I. D. and Degrange, B. and Deil, C. and deWilt, P. and Djannati-Ata{\"i}, A. and Domainko, W. and Donath, A. and Dubus, G. and Dutson, K. and Dyks, J. and Dyrda, M. and Edwards, T. and Egberts, Kathrin and Eger, P. and Espigat, P. and Farnier, C. and Fegan, S. and Feinstein, F. and Fernandes, M. V. and Fernandez, D. and Fiasson, A. and Fontaine, G. and Foerster, A. and Fuessling, M. and Gabici, S. and Gajdus, M. and Gallant, Y. A. and Garrigoux, T. and Giavitto, G. and Giebels, B. and Glicenstein, J. F. and Gottschall, D. and Grondin, M. -H. and Grudzinska, M. and Hadasch, D. and Haeffner, S. and Hahn, J. and Harris, J. and Heinzelmann, G. and Henri, G. and Hermann, G. and Hervet, O. and Hillert, A. and Hinton, James Anthony and Hofmann, W. and Hofverberg, P. and Holler, Markus and Horns, D. and Ivascenko, A. and Jacholkowska, A. and Jahn, C. and Jamrozy, M. and Janiak, M. and Jankowsky, F. and Jung-Richardt, O. and Kastendieck, M. A. and Katarzynski, K. and Katz, U. and Kaufmann, S. and Khelifi, B. and Kieffer, M. and Klepser, S. and Klochkov, D. and Kluzniak, W. and Kolitzus, D. and Komin, Nu and Kosack, K. and Krakau, S. and Krayzel, F. and Krueger, P. P. and Laffon, H. and Lamanna, G. and Lefaucheur, J. and Lefranc, V. and Lemiere, A. and Lemoine-Goumard, M. and Lenain, J. P. and Lohse, T. and Lopatin, A. and Lu, C-C and Marandon, V. and Marcowith, Alexandre and Marx, R. and Maurin, G. and Maxted, N. and Mayer, Markus and McComb, T. J. L. and Mehault, J. and Meintjes, P. J. and Menzler, U. and Meyer, M. and Mitchell, A. M. W. and Moderski, R. and Mohamed, M. and Mora, K. and Moulin, Emmanuel and Murach, T. and de Naurois, M. and Niemiec, J. and Nolan, S. J. and Oakes, L. and Odaka, H. and Ohm, S. and Opitz, B. and Ostrowski, M. and Oya, I. and Panter, M. and Parsons, R. D. and Anibas, M. Paz and Pekeur, N. W. and Pelletier, G. and Petrucci, P-O and Peyaud, B. and Pita, S. and Poon, H. and Puehlhofer, G. and Punch, M. and Quirrenbach, A. and Raab, S. and Reichardt, I. and Reimer, A. and Reimer, O. and Renaud, M. and de los Reyes, R. and Rieger, F. and Romoli, C. and Rosier-Lees, S. and Rowell, G. and Rudak, B. and Rulten, C. B. and Sahakian, V. and Salek, D. and Sanchez, David M. and Santangelo, A. and Schlickeiser, R. and Schuessler, F. and Schulz, A. and Schwanke, U. and Schwarzburg, S. and Schwemmer, S. and Sol, H. and Spanier, F. and Spengler, G. and Spies, F. and Stawarz, L. and Steenkamp, R. and Stegmann, Christian and Stinzing, F. and Stycz, K. and Sushch, Iurii and Tavernet, J-P and Tavernier, T. and Taylor, A. M. and Terrier, R. and Tluczykont, M. and Trichard, C. and Valerius, K. and van Eldik, C. and van Soelen, B. and Vasileiadis, G. and Veh, J. and Venter, C. and Viana, A. and Vincent, P. and Vink, J. and Voelk, H. J. and Volpe, F. and Vorster, M. and Vuillaume, T. and Wagner, S. J. and Wagner, P. and Wagner, R. M. and Ward, M. and Weidinger, M. and Weitzel, Q. and White, R. and Wierzcholska, A. and Willmann, P. and Woernlein, A. and Wouters, D. and Yang, R. and Zabalza, V. and Zaborov, D. and Zacharias, M. and Zdziarski, A. A. and Zech, Alraune and Zechlin, H-S}, title = {HESS detection of TeV emission from the interaction region between the supernova remnant G349.7+0.2 and a molecular cloud}, series = {Astronomy and astrophysics : an international weekly journal}, volume = {574}, journal = {Astronomy and astrophysics : an international weekly journal}, publisher = {EDP Sciences}, address = {Les Ulis}, organization = {HESS Collaboration}, issn = {0004-6361}, doi = {10.1051/0004-6361/201425070}, pages = {7}, year = {2015}, abstract = {G349.7+0.2 is a young Galactic supernova remnant (SNR) located at the distance of 11.5 kpc and observed across the entire electromagnetic spectrum from radio to high energy (HE; 0.1 GeV < E < 100 GeV) gamma-rays. Radio and infrared observations indicate that the remnant is interacting with a molecular cloud. In this paper, the detection of very high energy (VHE, E > 100 GeV) gamma-ray emission coincident with this SNR with the High Energy Stereoscopic System (HESS.) is reported. This makes it one of the farthest Galactic SNR ever detected in this domain. An integral flux F(E > 400 GeV) = (6.5 +/- 1.1(stat) +/- 1.3(syst)) x 10-11 ph cm(-2) s(-1) corresponding to similar to 0.7\% of that of the Crab Nebula and to a luminosity of similar to 10(34) erg s(-1) above the same energy threshold, and a steep photon index Gamma(VHE) = 2.8 +/- 0.27(stat) +/- 0.20(syst) are measured. The analysis of more than 5 yr of Fermi-LAT data towards this source shows a power-law like spectrum with a best-fit photon index Gamma(HE) = 2.2 +/- 0.04.2(stat-0.31sys)(+0.13), The combined gamma-ray spectrum of 0349.7+0.2 can be described by either a broken power law (I3PL) or a power law with exponential (or sub exponential) cutoff (PLC). In the former case, the photon break energy is found at E-br,E-gamma = 551(-30)(+70) GeV, slightly higher than what is usually observed in the HE/VHE gamma-ray emitting middle-aged SNRs known to be interacting with molecular clouds. In the latter case. the exponential (respectively sub-exponential) cutoff energy is measured at E-cat,E-gamma = 1.4(-0.55)(+1.6) (respectively 0.35(-0.21)(+0.75)) TeV. A pion decay process resulting from the interaction of the accelerated protons and nuclei with the dense surrounding medium is clearly the preferred scenario to explain the gamma-ray emission. The BPL with a spectral steepening of 0.5-1 and the PLC provide equally good fits to the data. The product or the average gas density and the total energy content of accelerated protons and nuclei amounts to nu W-p similar to 5 x 10(51) erg cm(-3)}, language = {en} } @article{AbramowskiAharonianBenkhalietal.2015, author = {Abramowski, Attila and Aharonian, Felix A. and Benkhali, Faical Ait and Akhperjanian, A. G. and Ang{\"u}ner, Ekrem Oǧuzhan and Anton, Gisela and Backes, Michael and Balenderan, Shangkari and Balzer, Arnim and Barnacka, Anna and Becherini, Yvonne and Tjus, J. Becker and Bernl{\"o}hr, K. and Birsin, E. and Bissaldi, E. and Biteau, Jonathan and Boettcher, Markus and Boisson, Catherine and Bolmont, J. and Bordas, Pol and Brucker, J. and Brun, Francois and Brun, Pierre and Bulik, Tomasz and Carrigan, Svenja and Casanova, Sabrina and Chadwick, Paula M. and Chalme-Calvet, R. and Chaves, Ryan C. G. and Cheesebrough, A. and Chretien, M. and Colafrancesco, Sergio and Cologna, Gabriele and Conrad, Jan and Couturier, C. and Cui, Y. and Dalton, M. and Daniel, M. K. and Davids, I. D. and Degrange, B. and Deil, C. and deWilt, P. and Dickinson, H. J. and Djannati-Ata{\"i}, A. and Domainko, W. and Dubus, G. and Dutson, K. and Dyks, J. and Dyrda, M. and Edwards, T. and Egberts, Kathrin and Eger, P. and Espigat, P. and Farnier, C. and Fegan, S. and Feinstein, F. and Fernandes, M. V. and Fernandez, D. and Fiasson, A. and Fontaine, G. and Foerster, A. and Fuessling, M. and Gajdus, M. and Gallant, Y. A. and Garrigoux, T. and Giavitto, G. and Giebels, B. and Glicenstein, J. F. and Grondin, M. -H. and Grudzinska, M. and Haeffner, S. and Hahn, J. and Harris, J. and Heinzelmann, G. and Henri, G. and Hermann, G. and Hervet, O. and Hillert, A. and Hinton, James Anthony and Hofmann, W. and Hofverberg, P. and Holler, M. and Horns, D. and Jacholkowska, A. and Jahn, C. and Jamrozy, M. and Janiak, M. and Jankowsky, F. and Jung, I. and Kastendieck, M. A. and Katarzynski, K. and Katz, Uli and Kaufmann, S. and Khelifi, B. and Kieffer, M. and Klepser, S. and Klochkov, D. and Kluzniak, W. and Kneiske, Tanja and Kolitzus, D. and Komin, Nu. and Kosack, K. and Krakau, S. and Krayzel, F. and Krueger, P. P. and Laffon, H. and Lamanna, G. and Lefaucheur, J. and Lemiere, A. and Lemoine-Goumard, M. and Lenain, J. -P. and Lohse, T. and Lopatin, A. and Lu, C. -C. and Marandon, V. and Marcowith, Alexandre and Marx, R. and Maurin, G. and Maxted, N. and Mayer, M. and McComb, T. J. L. and Mehault, J. and Meintjes, P. J. and Menzler, U. and Meyer, M. and Moderski, R. and Mohamed, M. and Moulin, Emmanuel and Murach, T. and Naumann, C. L. and de Naurois, M. and Niemiec, J. and Nolan, S. J. and Oakes, L. and Odaka, H. and Ohm, S. and Wilhelmi, E. de Ona and Opitz, B. and Ostrowski, M. and Oya, I. and Panter, M. and Parsons, R. D. and Arribas, M. Paz and Pekeur, N. W. and Pelletier, G. and Perez, J. and Petrucci, P. -O. and Peyaud, B. and Pita, S. and Poon, H. and Puehlhofer, G. and Punch, M. and Quirrenbach, A. and Raab, S. and Raue, M. and Reichardt, I. and Reimer, A. and Reimer, Olaf and Renaud, M. and de los Reyes, R. and Rieger, F. and Rob, L. and Romoli, C. and Rosier-Lees, S. and Rowell, G. and Rudak, B. and Rulten, C. B. and Sahakian, V. and Sanchez, David M. and Santangelo, A. and Schlickeiser, R. and Schuessler, F. and Schulz, A. and Schwanke, U. and Schwarzburg, S. and Schwemmer, S. and Sol, H. and Spengler, G. and Spies, F. and Stawarz, L. and Steenkamp, R. and Stegmann, Christian and Stinzing, F. and Stycz, K. and Sushch, Iurii and Tavernet, J. -P. and Tavernier, T. and Taylor, A. M. and Terrier, R. and Tluczykont, M. and Trichard, C. and Valerius, K. and van Eldik, Christopher and van Soelen, B. and Vasileiadis, G. and Venter, C. and Viana, A. and Vincent, P. and Voelk, H. J. and Volpe, F. and Vorster, M. and Vuillaume, T. and Wagner, S. J. and Wagner, P. and Wagner, R. M. and Ward, M. and Weidinger, M. and Weitzel, Q. and White, R. and Wierzcholska, A. and Willmann, P. and Wrnlein, A. and Wouters, D. and Yang, R. and Zabalza, V. and Zacharias, M. and Zdziarski, A. A. and Zech, Alraune and Zechlin, H. -S. and Finke, J. and Fortin, P. and Horan, D.}, title = {The high-energy gamma-ray emission of AP Librae}, series = {Astronomy and astrophysics : an international weekly journal}, volume = {573}, journal = {Astronomy and astrophysics : an international weekly journal}, publisher = {EDP Sciences}, address = {Les Ulis}, organization = {HESS Collaboration}, issn = {0004-6361}, doi = {10.1051/0004-6361/201321436}, pages = {7}, year = {2015}, abstract = {The gamma-ray spectrum of the low-frequency-peaked BL Lac (LBL) object AP Librae is studied, following the discovery of very-high-energy (VHE; E > 100 GeV) gamma-ray emission up to the TeV range by the H.E.S.S. experiment. Thismakes AP Librae one of the few VHE emitters of the LBL type. The measured spectrum yields a flux of (8.8 +/- 1.5(stat) +/- 1.8(sys)) x 10(-12) cm(-2) s(-1) above 130 GeV and a spectral index of Gamma = 2.65 +/- 0.19(stat) +/- 0.20(sys). This study also makes use of Fermi-LAT observations in the high energy (HE, E > 100 MeV) range, providing the longest continuous light curve (5 years) ever published on this source. The source underwent a flaring event between MJD 56 306-56 376 in the HE range, with a flux increase of a factor of 3.5 in the 14 day bin light curve and no significant variation in spectral shape with respect to the low-flux state. While the H.E.S.S. and (low state) Fermi-LAT fluxes are in good agreement where they overlap, a spectral curvature between the steep VHE spectrum and the Fermi-LAT spectrum is observed. The maximum of the gamma-ray emission in the spectral energy distribution is located below the GeV energy range.}, language = {en} } @article{AbramowskiAharonianBenkhalietal.2015, author = {Abramowski, Attila and Aharonian, Felix A. and Benkhali, Faical Ait and Akhperjanian, A. G. and Ang{\"u}ner, Ekrem Oǧuzhan and Backes, Michael and Balenderan, Shangkari and Balzer, Arnim and Barnacka, Anna and Becherini, Yvonne and Becker-Tjus, J. and Berge, David and Bernhard, Sabrina and Bernl{\"o}hr, K. and Birsin, E. and Biteau, Jonathan and Boettcher, Markus and Boisson, Catherine and Bolmont, J. and Bordas, Pol and Bregeon, Johan and Brun, Francois and Brun, Pierre and Bryan, Mark and Bulik, Tomasz and Carrigan, Svenja and Casanova, Sabrina and Chadwick, Paula M. and Chakraborty, N. and Chalme-Calvet, R. and Chaves, Ryan C. G. and Chretien, M. and Colafrancesco, Sergio and Cologna, Gabriele and Conrad, Jan and Couturier, C. and Cui, Y. and Dalton, M. and Davids, I. D. and Degrange, B. and Deil, C. and de Wilt, P. and Djannati-Ata{\"i}, A. and Domainko, W. and Donath, A. and Dubus, G. and Dutson, K. and Dyks, J. and Dyrda, M. and Edwards, T. and Egberts, Kathrin and Eger, P. and Espigat, P. and Farnier, C. and Fegan, S. and Feinstein, F. and Fernandes, M. V. and Fernandez, D. and Fiasson, A. and Fontaine, G. and Foerster, A. and Fuessling, M. and Gabici, S. and Gajdus, M. and Gallant, Y. A. and Garrigoux, T. and Giavitto, G. and Giebels, B. and Glicenstein, J. F. and Gottschall, D. and Grondin, M-H. and Grudzinska, M. and Hadasch, D. and Haeffner, S. and Hahn, J. and Harris, J. and Heinzelmann, G. and Henri, G. and Hermann, G. and Hervet, O. and Hillert, A. and Hinton, James Anthony and Hofmann, W. and Hofverberg, P. and Holler, M. and Horns, D. and Ivascenko, A. and Jacholkowska, A. and Jahn, C. and Jamrozy, M. and Janiak, M. and Jankowsky, F. and Jung, I. and Kastendieck, M. A. and Katarzynski, K. and Katz, U. and Kaufmann, S. and Khelifi, B. and Kieffer, M. and Klepser, S. and Klochkov, D. and Kluzniak, W. and Kolitzus, D. and Komin, Nu. and Kosack, K. and Krakau, S. and Krayzel, F. and Krueger, P. P. and Laffon, H. and Lamanna, G. and Lefaucheur, J. and Lefranc, V. and Lemiere, A. and Lemoine-Goumard, M. and Lenain, J-P. and Lohse, T. and Lopatin, A. and Lu, C-C. and Marandon, V. and Marcowith, Alexandre and Marx, R. and Maurin, G. and Maxted, N. and Mayer, M. and McComb, T. J. L. and Mehault, J. and Meintjes, P. J. and Menzler, U. and Meyer, M. and Mitchell, A. M. W. and Moderski, R. and Mohamed, M. and Mora, K. and Moulin, Emmanuel and Murach, T. and de Naurois, M. and Niemiec, J. and Nolan, S. J. and Oakes, L. and Odaka, H. and Ohm, S. and Opitz, B. and Ostrowski, M. and Oya, I. and Panter, M. and Parsons, R. D. and Arribas, M. Paz and Pekeur, N. W. and Pelletier, G. and Perez, J. and Petrucci, P-O. and Peyaud, B. and Pita, S. and Poon, H. and Puehlhofer, G. and Punch, M. and Quirrenbach, A. and Raab, S. and Reichardt, I. and Reimer, A. and Reimer, O. and Renaud, M. and de los Reyes, R. and Rieger, F. and Rob, L. and Romoli, C. and Rosier-Lees, S. and Rowell, G. and Rudak, B. and Rulten, C. B. and Sahakian, V. and Salek, D. and Sanchez, David M. and Santangelo, A. and Schlickeiser, R. and Schuessler, F. and Schulz, A. and Schwanke, U. and Schwarzburg, S. and Schwemmer, S. and Sol, H. and Spanier, F. and Spengler, G. and Spies, F. and Stawarz, L. and Steenkamp, R. and Stegmann, Christian and Stinzing, F. and Stycz, K. and Sushch, Iurii and Tavernet, J-P. and Tavernier, T. and Taylor, A. M. and Terrier, R. and Tluczykont, M. and Trichard, C. and Valerius, K. and van Eldik, C. and van Soelen, B. and Vasileiadis, G. and Veh, J. and Venter, C. and Viana, A. and Vincent, P. and Vink, J. and Voelk, H. J. and Volpe, F. and Vorster, M. and Vuillaume, T. and Wagner, S. J. and Wagner, P. and Wagner, R. M. and Ward, M. and Weidinger, M. and Weitzel, Q. and White, R. and Wierzcholska, A. and Willmann, P. and Woernlein, A. and Wouters, D. and Yang, R. and Zabalza, V. and Zaborov, D. and Zacharias, M. and Zdziarski, A. A. and Zech, Alraune and Zechlin, H-S.}, title = {The exceptionally powerful TeV gamma-ray emitters in the Large Magellanic Cloud}, series = {Science}, volume = {347}, journal = {Science}, number = {6220}, publisher = {American Assoc. for the Advancement of Science}, address = {Washington}, organization = {HESS Collaboration}, issn = {0036-8075}, doi = {10.1126/science.1261313}, pages = {406 -- 412}, year = {2015}, abstract = {The Large Magellanic Cloud, a satellite galaxy of the Milky Way, has been observed with the High Energy Stereoscopic System (H.E.S.S.) above an energy of 100 billion electron volts for a deep exposure of 210 hours. Three sources of different types were detected: the pulsar wind nebula of the most energetic pulsar known, N 157B; the radio-loud supernova remnant N 132D; and the largest nonthermal x-ray shell, the superbubble 30 Dor C. The unique object SN 1987A is, unexpectedly, not detected, which constrains the theoretical framework of particle acceleration in very young supernova remnants. These detections reveal the most energetic tip of a g-ray source population in an external galaxy and provide via 30 Dor C the unambiguous detection of g-ray emission from a superbubble.}, language = {en} } @article{AliuArchambaultAuneetal.2014, author = {Aliu, E. and Archambault, S. and Aune, T. and Behera, B. and Beilicke, M. and Benbow, W. and Berger, K. and Bird, R. and Bouvier, A. and Buckley, J. H. and Bugaev, V. and Byrum, K. and Cerruti, M. and Chen, X. and Ciupik, L. and Connolly, M. P. and Cui, W. and Duke, C. and Dumm, J. and Errando, M. and Falcone, A. and Federici, S. and Feng, Q. and Finley, J. P. and Fortin, P. and Fortson, L. and Furniss, A. and Galante, N. and Gillanders, G. H. and Griffin, S. and Griffiths, S. T. and Grube, J. and Gyuk, G. and Hanna, D. and Holder, J. and Hughes, G. and Humensky, T. B. and Kaaret, P. and Kertzman, M. and Khassen, Y. and Kieda, D. and Krawczynski, H. and Krennrich, F. and Lang, M. J. and Madhavan, A. S. and Maier, G. and Majumdar, P. and McCann, A. and Moriarty, P. and Mukherjee, R. and Nieto, D. and Ong, R. A. and Otte, A. N. and Park, N. and Perkins, J. S. and Pohl, M. and Popkow, A. and Prokoph, H. and Quinn, J. and Ragan, K. and Rajotte, J. and Reyes, L. C. and Reynolds, P. T. and Richards, G. T. and Roache, E. and Rousselle, J. and Sembroski, G. H. and Sheidaei, F. and Skole, C. and Smith, A. W. and Staszak, D. and Stroh, M. and Telezhinsky, Igor O. and Theiling, M. and Tucci, J. V. and Tyler, J. and Varlotta, A. and Vincent, S. and Wakely, S. P. and Weinstein, A. and Welsing, R. and Williams, D. A. and Zajczyk, A. and Zitzer, B. and Abramowski, Attila and Aharonian, Felix A. and Benkhali, Faical Ait and Akhperjanian, A. G. and Ang{\"u}ner, Ekrem Oǧuzhan and Anton, Gisela and Balenderan, Shangkari and Balzer, Arnim and Barnacka, Anna and Becherini, Yvonne and Tjus, J. Becker and Bernl{\"o}hr, K. and Birsin, E. and Bissaldi, E. and Biteau, Jonathan and Boettcher, Markus and Boisson, Catherine and Bolmont, J. and Bordas, Pol and Brucker, J. and Brun, Francois and Brun, Pierre and Bulik, Tomasz and Carrigan, Svenja and Casanova, Sabrina and Cerruti, M. and Chadwick, Paula M. and Chalme-Calvet, R. and Chaves, Ryan C. G. and Cheesebrough, A. and Chretien, M. and Colafrancesco, Sergio and Cologna, Gabriele and Conrad, Jan and Couturier, C. and Dalton, M. and Daniel, M. K. and Davids, I. D. and Degrange, B. and Deil, C. and deWilt, P. and Dickinson, H. J. and Djannati-Ata{\"i}, A. and Domainko, W. and Dubus, G. and Dutson, K. and Dyks, J. and Dyrda, M. and Edwards, T. and Egberts, Kathrin and Eger, P. and Espigat, P. and Farnier, C. and Fegan, S. and Feinstein, F. and Fernandes, M. V. and Fernandez, D. and Fiasson, A. and Fontaine, G. and Foerster, A. and Fuessling, M. and Gajdus, M. and Gallant, Y. A. and Garrigoux, T. and Giavitto, G. and Giebels, B. and Glicenstein, J. F. and Grondin, M. -H. and Grudzinska, M. and Haeffner, S. and Hahn, J. and Harris, J. and Heinzelmann, G. and Henri, G. and Hermann, G. and Hervet, O. and Hillert, A. and Hinton, James Anthony and Hofmann, W. and Hofverberg, P. and Holler, M. and Horns, D. and Jacholkowska, A. and Jahn, C. and Jamrozy, M. and Janiak, M. and Jankowsky, F. and Jung, I. and Kastendieck, M. A. and Katarzynski, K. and Katz, U. and Kaufmann, S. and Khelifi, B. and Kieffer, M. and Klepser, S. and Klochkov, D. and Kluzniak, W. and Kneiske, T. and Kolitzus, D. and Komin, Nu. and Kosack, K. and Krakau, S. and Krayzel, F. and Krueger, P. P. and Laffon, H. and Lamanna, G. and Lefaucheur, J. and Lemiere, A. and Lemoine-Goumard, M. and Lenain, J. -P. and Lennarz, D. and Lohse, T. and Lopatin, A. and Lu, C. -C. and Marandon, V. and Marcowith, Alexandre and Marx, R. and Maurin, G. and Maxted, N. and Mayer, M. and McComb, T. J. L. and Mehault, J. and Menzler, U. and Meyer, M. and Moderski, R. and Mohamed, M. and Moulin, Emmanuel and Murach, T. and Naumann, C. L. and de Naurois, M. and Niemiec, J. and Nolan, S. J. and Oakes, L. and Ohm, S. and Wilhelmi, E. de Ona and Opitz, B. and Ostrowski, M. and Oya, I. and Panter, M. and Parsons, R. D. and Arribas, M. Paz and Pekeur, N. W. and Pelletier, G. and Perez, J. and Petrucci, P. -O. and Peyaud, B. and Pita, S. and Poon, H. and Puehlhofer, G. and Punch, M. and Quirrenbach, A. and Raab, S. and Raue, M. and Reimer, A. and Reimer, O. and Renaud, M. and de los Reyes, R. and Rieger, F. and Rob, L. and Romoli, C. and Rosier-Lees, S. and Rowell, G. and Rudak, B. and Rulten, C. B. and Sahakian, V. and Sanchez, David M. and Santangelo, A. and Schlickeiser, R. and Schuessler, F. and Schulz, A. and Schwanke, U. and Schwarzburg, S. and Schwemmer, S. and Sol, H. and Spengler, G. and Spies, F. and Stawarz, L. and Steenkamp, R. and Stegmann, Christian and Stinzing, F. and Stycz, K. and Sushch, Iurii and Szostek, A. and Tavernet, J. -P. and Tavernier, T. and Taylor, A. M. and Terrier, R. and Tluczykont, M. and Trichard, C. and Valerius, K. and van Eldik, C. and Vasileiadis, G. and Venter, C. and Viana, A. and Vincent, P. and Voelk, H. J. and Volpe, F. and Vorster, M. and Wagner, S. J. and Wagner, P. and Ward, M. and Weidinger, M. and Weitzel, Q. and White, R. and Wierzcholska, A. and Willmann, P. and Woernlein, A. and Wouters, D. and Zacharias, M. and Zajczyk, A. and Zdziarski, A. A. and Zech, Alraune and Zechlin, H. -S.}, title = {Long-term TeV and X-RAY observations of the GAMMA- RAY binary hess J0632+057}, series = {The astrophysical journal : an international review of spectroscopy and astronomical physics}, volume = {780}, journal = {The astrophysical journal : an international review of spectroscopy and astronomical physics}, number = {2}, publisher = {IOP Publ. Ltd.}, address = {Bristol}, organization = {VERITAS Collaboration, HESS Collaboration}, issn = {0004-637X}, doi = {10.1088/0004-637X/780/2/168}, pages = {14}, year = {2014}, language = {en} } @article{AbramowskiAharonianBenkhalietal.2014, author = {Abramowski, Attila and Aharonian, Felix A. and Benkhali, Faical Ait and Akhperjanian, A. G. and Ang{\"u}ner, Ekrem Oǧuzhan and Anton, Gisela and Balenderan, Shangkari and Balzer, Arnim and Barnacka, Anna and Becherini, Yvonne and Tjus, J. Becker and Bernl{\"o}hr, K. and Birsin, E. and Bissaldi, E. and Biteau, Jonathan and Boettcher, Markus and Boisson, Catherine and Bolmont, J. and Bordas, Pol and Brucker, J. and Brun, Francois and Brun, Pierre and Bulik, Tomasz and Carrigan, Svenja and Casanova, Sabrina and Cerruti, M. and Chadwick, Paula M. and Chalme-Calvet, R. and Chaves, Ryan C. G. and Cheesebrough, A. and Chretien, M. and Colafrancesco, Sergio and Cologna, Gabriele and Conrad, Jan and Couturier, C. and Cui, Y. and Dalton, M. and Daniel, M. K. and Davids, I. D. and Degrange, B. and Deil, C. and dewilt, P. and Dickinson, H. J. and Djannati-Ata{\"i}, A. and Domainko, W. and Dubus, G. and Dutson, K. and Dyks, J. and Dyrda, M. and Edwards, T. and Egberts, Kathrin and Eger, P. and Espigat, P. and Farnier, C. and Fegan, S. and Feinstein, F. and Fernandes, M. V. and Fernandez, D. and Fiasson, A. and Fontaine, G. and Foerster, A. and Fuessling, M. and Gajdus, M. and Gallant, Y. A. and Garrigoux, T. and Giavitto, G. and Giebels, B. and Glicenstein, J. F. and Grondin, M. -H. and Grudzinska, M. and Haeffner, S. and Hahn, J. and Harris, J. and Heinzelmann, G. and Henri, G. and Hermann, G. and Hervet, O. and Hillert, A. and Hinton, James Anthony and Hofmann, W. and Hofverberg, P. and Holler, M. and Horns, D. and Jacholkowska, A. and Jahn, C. and Jamrozy, M. and Janiak, M. and Jankowsky, F. and Jung, I. and Kastendieck, M. A. and Katarzynski, K. and Katz, U. and Kaufmann, S. and Khelifi, B. and Kieffer, M. and Klepser, S. and Klochkov, D. and Kluzniak, W. and Kneiske, T. and Kolitzus, D. and Komin, Nu. and Kosack, K. and Krakau, S. and Krayzel, F. and Krueger, P. P. and Laffon, H. and Lamanna, G. and Lefaucheur, J. and Lemiere, A. and Lemoine-Goumard, M. and Lenain, J. -P. and Lennarz, D. and Lohse, T. and Lopatin, A. and Lu, C. -C. and Marandon, V. and Marcowith, Alexandre and Marx, R. and Maurin, G. and Maxted, N. and Mayer, M. and McComb, T. J. L. and Mehault, J. and Meintjes, P. J. and Menzler, U. and Meyer, M. and Moderski, R. and Mohamed, M. and Moulin, Emmanuel and Murach, T. and Naumann, C. L. and de Naurois, M. and Niemiec, J. and Nolan, S. J. and Oakes, L. and Ohm, S. and Wilhelmi, E. de Ona and Opitz, B. and Ostrowski, M. and Oya, I. and Panter, M. and Parsons, R. D. and Arribas, M. Paz and Pekeur, N. W. and Pelletier, G. and Perez, J. and Petrucci, P. -O. and Peyaud, B. and Pita, S. and Poon, H. and Puehlhofer, G. and Punch, M. and Quirrenbach, A. and Raab, S. and Raue, M. and Reimer, A. and Reimer, O. and Renaud, M. and de los Reyes, R. and Rieger, F. and Rob, L. and Romoli, C. and Rosier-Lees, S. and Rowell, G. and Rudak, B. and Rulten, C. B. and Sahakian, V. and Sanchez, David M. and Santangelo, A. and Schlickeiser, R. and Schuessler, F. and Schulz, A. and Schwanke, U. and Schwarzburg, S. and Schwemmer, S. and Sol, H. and Spengler, G. and Spies, F. and Stawarz, L. and Steenkamp, R. and Stegmann, Christian and Stinzing, F. and Stycz, K. and Sushch, Iurii and Szostek, A. and Tavernet, J. -P. and Tavernier, T. and Taylor, A. M. and Terrier, R. and Tluczykont, M. and Trichard, C. and Valerius, K. and van Eldik, C. and van Soelen, B. and Vasileiadis, G. and Venter, C. and Viana, A. and Vincent, P. and Voelk, H. J. and Volpe, F. and Vorster, M. and Vuillaume, T. and Wagner, S. J. and Wagner, P. and Ward, M. and Weidinger, M. and Weitzel, Q. and White, R. and Wierzcholska, A. and Willmann, P. and Woernlein, A. and Wouters, D. and Zabalza, V. and Zacharias, M. and Zajczyk, A. and Zdziarski, A. A. and Zech, Alraune and Zechlin, H. -S.}, title = {HESS J1818-154, a new composite supernova remnant discovered in TeV gamma rays and X-rays}, series = {Astronomy and astrophysics : an international weekly journal}, volume = {562}, journal = {Astronomy and astrophysics : an international weekly journal}, publisher = {EDP Sciences}, address = {Les Ulis}, organization = {HESS Collaboration}, issn = {0004-6361}, doi = {10.1051/0004-6361/201322914}, pages = {10}, year = {2014}, abstract = {Composite supernova remnants (SNRs) constitute a small subclass of the remnants of massive stellar explosions where non-thermal radiation is observed from both the expanding shell-like shock front and from a pulsar wind nebula (PWN) located inside of the SNR. These systems represent a unique evolutionary phase of SNRs where observations in the radio, X-ray, and gamma-ray regimes allow the study of the co-evolution of both these energetic phenomena. In this article, we report results from observations of the shell-type SNR G15.4+0.1 performed with the High Energy Stereoscopic System (H. E. S. S.) and XMM-Newton. A compact TeV gamma-ray source, HESS J1818-154, located in the center and contained within the shell of G15.4+0.1 is detected by H. E. S. S. and featurs a spectrum best represented by a power-law model with a spectral index of -2.3 +/- 0.3(stat) +/- 0.2(sys) and an integral flux of F(>0.42 TeV) = (0.9 +/- 0.3(stat) +/- 0.2(sys)) x 10(-12) cm(-2) s(-1). Furthermore, a recent observation with XMM-Newton reveals extended X-ray emission strongly peaked in the center of G15.4+0.1. The X-ray source shows indications of an energy-dependent morphology featuring a compact core at energies above 4 keV and more extended emission that fills the entire region within the SNR at lower energies. Together, the X-ray and VHE gamma-ray emission provide strong evidence of a PWN located inside the shell of G15.4+0.1 and this SNR can therefore be classified as a composite based on these observations. The radio, X-ray, and gamma-ray emission from the PWN is compatible with a one-zone leptonic model that requires a low average magnetic field inside the emission region. An unambiguous counterpart to the putative pulsar, which is thought to power the PWN, has been detected neither in radio nor in X-ray observations of G15.4+0.1.}, language = {en} } @article{AbramowskiAharonianBenkhalietal.2014, author = {Abramowski, Attila and Aharonian, Felix A. and Benkhali, Faical Ait and Akhperjanian, A. G. and Ang{\"u}ner, Ekrem Oǧuzhan and Backes, Michael and Balenderan, Shangkari and Balzer, Arnim and Barnacka, Anna and Becherini, Yvonne and Tjus, J. Becker and Berge, David and Bernhard, Sabrina and Bernl{\"o}hr, K. and Birsin, E. and Biteau, Jonathan and B{\"o}ttcher, Markus and Boisson, Catherine and Bolmont, J. and Bordas, Pol and Bregeon, Johan and Brun, Francois and Brun, Pierre and Bryan, Mark and Bulik, Tomasz and Carrigan, Svenja and Casanova, Sabrina and Chadwick, Paula M. and Chakraborty, N. and Chalme-Calvet, R. and Chaves, Ryan C. G. and Chretien, M. and Colafrancesco, Sergio and Cologna, Gabriele and Conrad, Jan and Couturier, C. and Cui, Y. and Dalton, M. and Davids, I. D. and Degrange, B. and Deil, C. and dewilt, P. and Djannati-Ata{\"i}, A. and Domainko, W. and Donath, A. and Dubus, G. and Dutson, K. and Dyks, J. and Dyrda, M. and Edwards, T. and Egberts, Kathrin and Eger, P. and Espigat, P. and Farnier, C. and Fegan, S. and Feinstein, F. and Fernandes, M. V. and Fernandez, D. and Fiasson, A. and Fontaine, G. and Forster, A. and Fuling, M. and Gabici, S. and Gajdus, M. and Gallant, Y. A. and Garrigoux, T. and Giavitto, G. and Giebels, B. and Glicenstein, J. F. and Gottschall, D. and Grondin, M. -H. and Grudzinska, M. and Hadsch, D. and Haeffner, S. and Hahn, J. and Harris, J. and Heinzelmann, G. and Henri, G. and Hermann, G. and Hervet, O. and Hillert, A. and Hinton, James Anthony and Hofmann, W. and Hofverberg, P. and Holler, Markus and Horns, D. and Ivascenko, A. and Jacholkowska, A. and Jahn, C. and Jamrozy, M. and Janiak, M. and Jankowsky, F. and Jung, I. and Kastendieck, M. A. and Katarzynski, K. and Katz, U. and Kaufmann, S. and Khelifi, B. and Kiefeer, M. and Klepser, S. and Klochkov, D. and Kluzniak, W. and Kolitzus, D. and Komin, Nu. and Kosack, K. and Krakau, S. and Krayzel, F. and Kruger, P. P. and Laffon, H. and Lamanna, G. and Lefaucheur, J. and Lefranc, V. and Lemiere, A. and Lemoine-Goumard, M. and Lenain, J. -P. and Lohse, T. and Lopatin, A. and Lu, C. -C. and Marandon, V. and Marcowith, Alexandre and Marx, R. and Maurin, G. and Maxted, N. and Mayer, M. and McComb, T. J. L. and Mehault, J. and Meintjes, P. J. and Menzler, U. and Meyer, M. and Mitchell, A. M. W. and Moderski, R. and Mohamed, M. and Mora, K. and Moulin, Emmanuel and Murach, T. and de Naurois, M. and Niemiec, J. and Nolan, S. J. and Oakes, L. and Odaka, H. and Ohm, S. and Opitz, B. and Ostrowski, M. and Oya, I. and Panter, M. and Parsons, R. D. and Arribas, M. Paz and Pekeur, N. W. and Pelletier, G. and Perez, J. and Petrucci, P. -O. and Peyaud, B. and Pita, S. and Poon, H. and Puhlhofer, G. and Punch, M. and Quirrenbach, A. and Raab, S. and Reichardt, I. and Reimer, A. and Reimer, O. and Renaud, M. and de los Reyes, R. and Rieger, F. and Rob, L. and Romoli, C. and Rosier-Lees, S. and Rowell, G. and Rudak, B. and Rulten, C. B. and Sahakian, V. and Salek, D. and Sanchez, David M. and Santangelo, A. and Schlickeiser, R. and Schussler, F. and Schulz, A. and Schwanke, U. and Schwarzburg, S. and Schwemmer, S. and Sol, H. and Spanier, F. and Spengler, G. and Spies, F. and Stawarz, L. and Steenkamp, R. and Stegmann, Christian and Stinzing, F. and Stycz, K. and Sushch, Iurii and Tavernet, J. -P. and Tavernier, T. and Taylor, A. M. and Terrier, R. and Tluczykont, M. and Trichard, C. and Valerius, K. and Van Eldik, C. and Van Soelen, B. and Vasileiadis, G. and Veh, J. and Venter, C. and Viana, A. and Vincent, P. and Vink, J. and Volk, H. J. and Volpe, F. and Vorster, M. and Vuillaume, T. and Wagner, S. J. and Wagner, P. and Wagner, R. M. and Ward, M. and Weidinger, M. and Weitzel, Q. and White, R. and Wierzcholska, A. and Willmann, P. and Wornlein, A. and Wouters, D. and Yang, R. and Zabalza, V. and Zaborov, D. and Zacharias, M. and Zdziarski, A. A. and Zech, Alraune and Zechlin, H. -S.}, title = {Long-term monitoring of PKS2155-304 with ATOM and HESS:investigation of optical/gamma-ray correlations in different spectral states}, series = {Astronomy and astrophysics : an international weekly journal}, volume = {571}, journal = {Astronomy and astrophysics : an international weekly journal}, publisher = {EDP Sciences}, address = {Les Ulis}, organization = {HESSS Collaboration}, issn = {0004-6361}, doi = {10.1051/0004-6361/201424142}, pages = {10}, year = {2014}, abstract = {In this paper we report on the analysis of all the available optical and very high-energy gamma-ray (> 200 GeV) data for the BL Lac object PKS 2155-304, collected simultaneously with the ATOM and H.E.S.S. telescopes from 2007 until 2009. This study also includes X-ray (RXTE, Swift) and high-energy gamma-ray (Fermi-LAT) data. During the period analysed, the source was transitioning from its flaring to quiescent optical states, and was characterized by only moderate flux changes at different wavelengths on the timescales of days and months. A flattening of the optical continuum with an increasing optical flux can be noted in the collected dataset, but only occasionally and only at higher flux levels. We did not find any universal relation between the very high-energy gamma-ray and optical flux changes on the timescales from days and weeks up to several years. On the other hand, we noted that at higher flux levels the source can follow two distinct tracks in the optical flux-colour diagrams, which seem to be related to distinct gamma-ray states of the blazar. The obtained results therefore indicate a complex scaling between the optical and gamma-ray emission of PKS 2155 304, with different correlation patterns holding at different epochs, and a gamma-ray flux depending on the combination of an optical flux and colour rather than a flux alone.}, language = {en} } @article{AbramowskiAharonianBenkhalietal.2014, author = {Abramowski, Attila and Aharonian, Felix A. and Benkhali, Faical Ait and Akhperjanian, A. G. and Ang{\"u}ner, Ekrem Oǧuzhan and Anton, Gisela and Backes, Michael and Balenderan, Shangkari and Balzer, Arnim and Barnacka, Anna and Becherini, Yvonne and Tjus, J. Becker and Bernl{\"o}hr, K. and Birsin, E. and Bissaldi, E. and Biteau, Jonathan and Boettcher, Markus and Boisson, Catherine and Bolmont, J. and Bordas, Pol and Brucker, J. and Brun, Francois and Brun, Pierre and Bulik, Tomasz and Carrigan, Svenja and Casanova, Sabrina and Chadwick, Paula M. and Chalme-Calvet, R. and Chaves, Ryan C. G. and Cheesebrough, A. and Chretien, M. and Colafrancesco, Sergio and Cologna, Gabriele and Conrad, Jan and Couturier, C. and Cui, Y. and Djannati-Ata{\"i}, A. and Domainko, W. and Dubus, G. and Dutson, K. and Dyks, J. and Dyrda, M. and Edwards, T. and Egberts, Kathrin and Eger, P. and Espigat, P. and Farnier, C. and Fegan, S. and Feinstein, F. and Fernandes, M. V. and Fernandez, D. and Fiasson, A. and Fontaine, G. and Foerster, A. and Fussling, Matthias and Gajdus, M. and Gallant, Y. A. and Garrigoux, T. and Giavitto, G. and Giebels, B. and Glicenstein, J. F. and Grondin, M. -H. and Grudzinska, M. and Haeffner, S. and Hahn, J. and Harris, J. and Heinzelmann, G. and Henri, G. and Hermann, G. and Hervet, O. and Hillert, A. and Hinton, James Anthony and Hofmann, W. and Hofverberg, P. and Holler, M. and Horns, D. and Jacholkowska, A. and Jahn, C. and Jamrozy, M. and Janiak, M. and Jankowsky, F. and Jung, I. and Kastendieck, M. A. and Katarzynski, K. and Katz, U. and Kaufmann, S. and Khelifi, B. and Kieffer, M. and Klepser, S. and Klochkov, D. and Kluzniak, W. and Kneiske, T. and Kolitzus, D. and Komin, Nu. and Kosack, K. and Krakau, S. and Krayzel, F. and Krueger, P. P. and Laffon, H. and Lamanna, G. and Lefaucheur, J. and Lemiere, A. and Lemoine-Goumard, M. and Lenain, J. -P. and Lohse, T. and Lopatin, A. and Lu, C. -C. and Marandon, V. and Marcowith, Alexandre and Marx, R. and Maurin, G. and Maxted, N. and Mayer, M. and McComb, T. J. L. and Mehault, J. and Meintjes, P. J. and Menzler, U. and Meyer, M. and Moderski, R. and Mohamed, M. and Moulin, Emmanuel and Murach, T. and Naumann, C. L. and de Naurois, M. and Niemiec, J. and Nolan, S. J. and Oakes, L. and Odaka, H. and Ohm, S. and Wilhelmi, E. de Ona and Opitz, B. and Ostrowski, M. and Oya, I. and Panter, M. and Parsons, R. D. and Arribas, M. Paz and Pekeur, N. W. and Pelletier, G. and Perez, J. and Petrucci, P. -O. and Peyaud, B. and Pita, S. and Poon, H. and Puehlhofer, G. and Punch, M. and Quirrenbach, A. and Raab, S. and Raue, M. and Reichardt, I. and Reimer, A. and Reimer, O. and Renaud, M. and Reyes, R. de los and Rieger, F. and Rob, L. and Romoli, C. and Rosier-Lees, S. and Rowell, G. and Rudak, B. and Rulten, C. B. and Sahakian, V. and Sanchez, David M. and Santangelo, A. and Schlickeiser, R. and Schuessler, F. and Schulz, A. and Schwanke, U. and Schwarzburg, S. and Schwemmer, S. and Sol, H. and Spengler, G. and Spies, F. and Stawarz, L. and Steenkamp, R. and Stegmann, Christian and Stinzing, F. and Stycz, K. and Sushch, Iurii and Tavernet, J. -P. and Tavernier, T. and Taylor, A. M. and Terrier, R. and Tluczykont, M. and Trichard, C. and Valerius, K. and van Eldik, C. and van Soelen, B. and Vasileiadis, G. and Venter, C. and Viana, A. and Vincent, P. and Voelk, H. J. and Volpe, F. and Vorster, M. and Vuillaume, T. and Wagner, S. J. and Wagner, P. and Wagner, R. M. and Ward, M. and Weidinger, M. and Weitzel, Q. and White, R. and Wierzcholska, A. and Willmann, P. and Woernlein, A. and Wouters, D. and Yang, R. and Zabalza, V. and Zacharias, M. and Zdziarski, A. A. and Zech, Alraune and Zechlin, H. -S. and Malyshev, D.}, title = {Search for extended gamma-ray emission around AGN with HESS and Fermi-LAT}, series = {Astronomy and astrophysics : an international weekly journal}, volume = {562}, journal = {Astronomy and astrophysics : an international weekly journal}, publisher = {EDP Sciences}, address = {Les Ulis}, organization = {HESS Collaboration}, issn = {0004-6361}, doi = {10.1051/0004-6361/201322510}, pages = {10}, year = {2014}, abstract = {Context. Very-high-energy (VHE; E > 100 GeV) gamma-ray emission from blazars inevitably gives rise to electron-positron pair production through the interaction of these gamma-rays with the extragalactic background light (EBL). Depending on the magnetic fields in the proximity of the source, the cascade initiated from pair production can result in either an isotropic halo around an initially- beamed source or a magnetically- broadened cascade :aux. Aims. Both extended pair-halo (PH) and magnetically broadened cascade (MBC) emission from regions surrounding the blazars 1ES 1101-232, IRS 0229+200, and PKS 2155-304 were searched for using VHE y-ray data taken with the High Energy Stereoscopic System (HESS.) and high-energy (HE; 100 MeV < E < 100 GeV) gamma-ray data with the Fermi Large Area Telescope (LAT). Methods. By comparing the angular distributions of the reconstructed gamma-ray events to the angular profiles calculated from detailed theoretical models, the presence of PH and MBC was investigated. Results. Upper limits on the extended emission around lES 1101-232, lES 0229+200, and PKS 2155-304 are found to be at a level of a few per cent of the Crab nebula flux above 1 TeV, depending on the assumed photon index of the cascade emission. Assuming strong extra-Galactic magnetic field (EGME) values, >10(-12) G, this limits the production of pair haloes developing from electromagnetic cascades. For weaker magnetic fields, in which electromagnetic cascades would result in MBCs. EGMF strengths in the range (0.3-3) x 10(-15) G were excluded for PKS 2155-304 at the 99\% confidence level, under the assumption of a 1 Mpc coherence length.}, language = {en} } @article{AbramowskiAharonianBenkhalietal.2014, author = {Abramowski, Attila and Aharonian, Felix A. and Benkhali, Faical Ait and Akhperjanian, A. G. and Ang{\"u}ner, Ekrem Oǧuzhan and Anton, Gisela and Balenderan, Shangkari and Balzer, Arnim and Barnacka, Anna and Becherini, Yvonne and Tjus, J. Becker and Bernl{\"o}hr, K. and Birsin, E. and Bissaldi, E. and Biteau, Jonathan and Boettcher, Markus and Boisson, Catherine and Bolmont, J. and Bordas, Pol and Brucker, J. and Brun, Francois and Brun, Pierre and Bulik, Tomasz and Carrigan, Svenja and Casanova, Sabrina and Cerruti, M. and Chadwick, Paula M. and Chalme-Calvet, R. and Chaves, Ryan C. G. and Cheesebrough, A. and Chretien, M. and Colafrancesco, Sergio and Cologna, Gabriele and Conrad, Jan and Couturier, C. and Dalton, M. and Daniel, M. K. and Davids, I. D. and Degrange, B. and Deil, C. and deWilt, P. and Dicldnson, H. J. and Djannati-Ata{\"i}, A. and Domainko, W. and Dubus, G. and Dutson, K. and Dyks, J. and Dyrda, M. and Edwards, T. and Egberts, Kathrin and Eger, P. and Espigat, P. and Farnier, C. and Fegan, S. and Feinstein, F. and Fernandes, M. V. and Fernandez, D. and Fiasson, A. and Fontaine, G. and Foerster, A. and Fuessling, Matthias and Gajdus, M. and Gallant, Y. A. and Garrigoux, T. and Giebels, B. and Glicenstein, J. F. and Grondin, M-H and Grudzinska, M. and Haeffner, S. and Hahn, J. and Harris, J. and Heinzelmann, G. and Henri, G. and Hermann, G. and Hervet, O. and Hillert, A. and Hinton, James Anthony and Hofmann, W. and Hofverberg, P. and Holler, Markus and Horns, D. and Jacholkowska, A. and Jahn, C. and Jamrozy, M. and Janiak, M. and Jankowsky, F. and Jung, I. and Kastendieck, M. A. and Katarzynski, K. and Katz, U. and Kaufmann, S. and Khelifi, B. and Kieffer, M. and Klepser, S. and Klochkov, D. and Kluzniak, W. and Kneiske, T. and Kolitzus, D. and Komin, Nu and Kosack, K. and Krakau, S. and Krayzel, F. and Krueger, P. P. and Laffon, H. and Lamanna, G. and Lefaucheur, J. and Lemiere, A. and Lemoine-Goumard, M. and Lenain, J-P and Lennarz, D. and Lohse, T. and Lopatin, A. and Lu, C-C and Marandon, V. and Marcowith, Alexandre and Marx, R. and Maurin, G. and Maxted, N. and Mayer, M. and McComb, T. J. L. and Mehault, J. and Menzler, U. and Meyer, M. and Moderski, R. and Mohamed, M. and Moulin, Emmanuel and Murach, T. and Naumann, C. L. and de Naurois, M. and Niemiec, J. and Nolan, S. J. and Oakes, L. and Ohm, S. and Wilhelmi, E. de Ona and Opitz, B. and Ostrowski, M. and Oya, I. and Panter, M. and Parsons, R. D. and Arribas, M. Paz and Pekeur, N. W. and Pelletier, G. and Perez, J. and Petrucci, P-O and Peyaud, B. and Pita, S. and Poon, H. and Puehlhofer, G. and Punch, M. and Quirrenbach, A. and Raab, S. and Raue, M. and Reimer, A. and Reimer, O. and Renaud, M. and de los Reyes, R. and Rieger, F. and Rob, L. and Romoli, C. and Rosier-Lees, S. and Rowell, G. and Rudak, B. and Rulten, C. B. and Sahakian, V. and Sanchez, David M. and Santangelo, A. and Schlickeiser, R. and Schuessler, F. and Schulz, A. and Schwanke, U. and Schwarzburg, S. and Schwemmer, S. and Sol, H. and Spengler, G. and Spies, F. and Stawarz, L. and Steenkamp, R. and Stegmann, Christian and Stinzing, F. and Stycz, K. and Sushch, Iurii and Szostek, A. and Tam, P. H. T. and Tavernet, J-P and Tavernier, T. and Taylor, A. M. and Terrier, R. and Tluczykont, M. and Trichard, C. and Valerius, K. and van Eldik, C. and Vasileiadis, G. and Venter, C. and Viana, A. and Vincent, P. and Voelk, H. J. and Volpe, F. and Vorster, M. and Wagner, S. J. and Wagner, P. and Ward, M. and Weidinger, M. and Weitzel, Q. and White, R. and Wierzcholska, A. and Willmann, P. and Woernlein, A. and Wouters, D. and Zacharias, M. and Zajczyk, A. and Zdziarski, A. A. and Zech, Alraune and Zechlin, H-S}, title = {Search for TeV Gamma-ray emission from GRB 100621A, an extremely bright GRB in X-rays, with HESS}, series = {Astronomy and astrophysics : an international weekly journal}, volume = {565}, journal = {Astronomy and astrophysics : an international weekly journal}, publisher = {EDP Sciences}, address = {Les Ulis}, organization = {HESS Collaboration}, issn = {0004-6361}, doi = {10.1051/0004-6361/201322984}, pages = {6}, year = {2014}, abstract = {The long gamma-ray burst (GRB) 100621A, at the time the brightest X-ray transient ever detected by Swift-XRT in the 0.3-10 keV range, has been observed with the H.E.S.S. imaging air Cherenkov telescope array, sensitive to gamma radiation in the very-high-energy (VHE, >100 GeV) regime. Due to its relatively small redshift of z similar to 0.5, the favourable position in the southern sky and the relatively short follow-up time (<700 s after the satellite trigger) of the H.E.S.S. observations, this GRB could be within the sensitivity reach of the HESS. instrument. The analysis of the HESS. data shows no indication of emission and yields an integral flux upper limit above similar to 380 GeV of 4.2 x 10(-12) cm(-2) s(-1) s (95\% confidence level), assuming a simple Band function extension model. A comparison to a spectral-temporal model, normalised to the prompt flux at sub-MeV energies, constraints the existence of a temporally extended and strong additional hard power law, as has been observed in the other bright X-ray GRB 130427A. A comparison between the HESS. upper limit and the contemporaneous energy output in X-rays constrains the ratio between the X-ray and VHE gamma-ray fluxes to be greater than 0.4. This value is an important quantity for modelling the afterglow and can constrain leptonic emission scenarios, where leptons are responsible for the X-ray emission and might produce VHE gamma rays.}, language = {en} } @article{AbramowskiAharonianBenkhalietal.2014, author = {Abramowski, Attila and Aharonian, Felix A. and Benkhali, Faical Ait and Akhperjanian, A. G. and Ang{\"u}ner, Ekrem Oǧuzhan and Anton, Gisela and Balenderan, Shangkari and Balzer, Arnim and Barnacka, Anna and Becherini, Yvonne and Tjus, J. Becker and Bernl{\"o}hr, K. and Birsin, E. and Bissaldi, E. and Biteau, Jonathan and Boettcher, Markus and Boisson, Catherine and Bolmont, J. and Bordas, Pol and Brucker, J. and Brun, Francois and Brun, Pierre and Bulik, Tomasz and Carrigan, Svenja and Casanova, Sabrina and Cerruti, M. and Chadwick, Paula M. and Chalme-Calvet, R. and Chaves, Ryan C. G. and Cheesebrough, A. and Chretien, M. and Colafrancesco, Sergio and Cologna, Gabriele and Conrad, Jan and Couturier, C. and Cui, Y. and Dalton, M. and Daniel, M. K. and Davids, I. D. and Degrange, B. and Deil, C. and dewilt, P. and Dicldnson, H. J. and Djannati-Ata{\"i}, A. and Domainko, W. and Dubus, G. and Dutson, K. and Dyks, J. and Dyrda, M. and Edwards, T. and Egberts, Kathrin and Eger, P. and Espigat, P. and Farnier, C. and Fegan, S. and Feinstein, F. and Fernandes, M. V. and Fernandez, D. and Fiasson, A. and Fontaine, G. and Foerster, A. and Fuessling, M. and Gajdus, M. and Gallant, Y. A. and Garrigoux, T. and Giavitto, G. and Giebels, B. and Glicenstein, J. F. and Grondin, M. -H. and Grudzinska, M. and Haeffner, S. and Hahn, J. and Harris, J. and Heinzelmann, G. and Henri, G. and Hermann, G. and Hervet, O. and Hillert, A. and Hinton, James Anthony and Hofmann, W. and Hofverberg, P. and Holler, M. and Horns, D. and Jacholkowska, A. and Jahn, C. and Jamrozy, M. and Janiak, M. and Jankowsky, F. and Jung, I. and Kastendieck, M. A. and Katarzynski, K. and Katz, U. and Kaufmann, S. and Khelifi, B. and Kieffer, M. and Klepser, S. and Klochkov, D. and Kluzniak, W. and Kneiske, T. and Kolitzus, D. and Komin, Nu. and Kosack, K. and Krakau, S. and Krayzel, F. and Krueger, P. P. and Laffon, H. and Lamanna, G. and Lefaucheur, J. and Lemiere, A. and Lemoine-Goumard, M. and Lenain, J. -P. and Lennarz, D. and Lohse, T. and Lopatin, A. and Lu, C. -C. and Marandon, V. and Marcowith, Alexandre and Marx, R. and Maurin, G. and Maxted, N. and Mayer, M. and McComb, T. J. L. and Mehault, J. and Meintjes, P. J. and Menzler, U. and Meyer, M. and Moderski, R. and Mohamed, M. and Moulin, Emmanuel and Murach, T. and Naumann, C. L. and de Naurois, M. and Niemiec, J. and Nolan, S. J. and Oakes, L. and Ohm, S. and Wilhelmi, E. de Ona and Opitz, B. and Ostrowski, M. and Oya, I. and Panter, M. and Parsons, R. D. and Arribas, M. Paz and Pekeur, N. W. and Pelletier, G. and Perez, J. and Petrucci, P. -O. and Peyaud, B. and Pita, S. and Poon, H. and Puehlhofer, G. and Punch, M. and Quirrenbach, A. and Raab, S. and Raue, M. and Reimer, A. and Reimer, O. and Renaud, M. and Reyes, R. de Los and Rieger, F. and Rob, L. and Romoli, C. and Rosier-Lees, S. and Rowell, G. and Rudak, B. and Rulten, C. B. and Sahakian, V. and Sanchez, David M. and Santangelo, A. and Schlickeiser, R. and Schuessler, F. and Schulz, A. and Schwanke, U. and Schwarzburg, S. and Schwemmer, S. and Sol, H. and Spengler, G. and Spies, F. and Stawarz, L. and Steenkamp, R. and Stegmann, Christian and Stinzing, F. and Stycz, K. and Sushch, Iurii and Szostek, A. and Tavernet, J. -P. and Tavernier, T. and Taylor, A. M. and Terrier, R. and Tluczykont, M. and Trichard, C. and Valerius, K. and van Eldik, C. and van Soelen, B. and Vasileiadis, G. and Venter, C. and Viana, A. and Vincent, P. and Voelk, H. J. and Volpe, F. and Vorster, M. and Vuillaume, T. and Wagner, S. J. and Wagner, P. and Ward, M. and Weidinger, M. and Weitzel, Q. and White, R. and Wierzcholska, A. and Willmann, P. and Woernlein, A. and Wouters, D. and Zabalza, V. and Zacharias, M. and Zajczyk, A. and Zdziarski, A. A. and Zech, Alraune and Zechlin, H. -S.}, title = {Flux upper limits for 47 AGN observed with HESS in 2004-2011}, series = {Astronomy and astrophysics : an international weekly journal}, volume = {564}, journal = {Astronomy and astrophysics : an international weekly journal}, publisher = {EDP Sciences}, address = {Les Ulis}, organization = {HESS Collaboration}, issn = {0004-6361}, doi = {10.1051/0004-6361/201322897}, pages = {10}, year = {2014}, abstract = {Context. About 40\% of the observation time of the High Energy Stereoscopic System (H.E.S.S.) is dedicated to studying active galactic nuclei (AGN), with the aim of increasing the sample of known extragalactic very-high-energy (VHE, E > 100 GeV) sources and constraining the physical processes at play in potential emitters. Aims. H.E.S.S. observations of AGN, spanning a period from April 2004 to December 2011, are investigated to constrain their gamma-ray fluxes. Only the 47 sources without significant excess detected at the position of the targets are presented. Methods. Upper limits on VHE fluxes of the targets were computed and a search for variability was performed on the nightly time scale. Results. For 41 objects, the flux upper limits we derived are the most constraining reported to date. These constraints at VHE are compared with the flux level expected from extrapolations of Fermi-LAT measurements in the two-year catalog of AGN. The H.E.S.S. upper limits are at least a factor of two lower than the extrapolated Fermi-LAT fluxes for 11 objects Taking into account the attenuation by the extragalactic background light reduces the tension for all but two of them, suggesting intrinsic curvature in the high-energy spectra of these two AGN. Conclusions. Compilation efforts led by current VHE instruments are of critical importance for target-selection strategies before the advent of the Cherenkov Telescope Array (CTA).}, language = {en} }