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Prospects for Cherenkov Telescope Array Observations of the Young Supernova Remnant RX J1713.7-3946
(2017)
Acero, F. ; Aloisio, R. ; Amans, J. ; Amato, Elena ; Antonelli, L. A. ; Aramo, C. ; Armstrong, T. ; Arqueros, F. ; Asano, Katsuaki ; Ashley, M. ; Backes, M. ; Balazs, C. ; Balzer, A. ; Bamba, Aya ; Barkov, Maxim ; Barrio, J. A. ; Benbow, Wystan ; Bernloehr, K. ; Beshley, V. ; Bigongiari, C. ; Biland, A. ; Bilinsky, A. ; Bissaldi, Elisabetta ; Biteau, J. ; Blanch, O. ; Blasi, P. ; Blazek, J. ; Boisson, C. ; Bonanno, G. ; Bonardi, A. ; Bonavolonta, C. ; Bonnoli, G. ; Braiding, C. ; Brau-Nogue, S. ; Bregeon, J. ; Brown, A. M. ; Bugaev, V. ; Bulgarelli, A. ; Bulik, T. ; Burton, Michael ; Burtovoi, A. ; Busetto, G. ; Bottcher, M. ; Cameron, R. ; Capalbi, M. ; Caproni, Anderson ; Caraveo, P. ; Carosi, R. ; Cascone, E. ; Cerruti, M. ; Chaty, Sylvain ; Chen, A. ; Chen, X. ; Chernyakova, M. ; Chikawa, M. ; Chudoba, J. ; Cohen-Tanugi, J. ; Colafrancesco, S. ; Conforti, V. ; Contreras, J. L. ; Costa, A. ; Cotter, G. ; Covino, Stefano ; Covone, G. ; Cumani, P. ; Cusumano, G. ; Daniel, M. ; Dazzi, F. ; De Angelis, A. ; De Cesare, G. ; De Franco, A. ; De Frondat, F. ; Dal Pino, E. M. de Gouveia ; De Lisio, C. ; Lopez, R. de los Reyes ; De Lotto, B. ; de Naurois, M. ; De Palma, F. ; Del Santo, M. ; Delgado, C. ; della Volpe, D. ; Di Girolamo, T. ; Di Giulio, C. ; Di Pierro, F. ; Di Venere, L. ; Doro, M. ; Dournaux, J. ; Dumas, D. ; Dwarkadas, Vikram V. ; Diaz, C. ; Ebr, J. ; Egberts, Kathrin ; Einecke, S. ; Elsaesser, D. ; Eschbach, S. ; Falceta-Goncalves, D. ; Fasola, G. ; Fedorova, E. ; Fernandez-Barral, A. ; Ferrand, Gilles ; Fesquet, M. ; Fiandrini, E. ; Fiasson, A. ; Filipovic, Miroslav D. ; Fioretti, V. ; Font, L. ; Fontaine, Gilles ; Franco, F. J. ; Freixas Coromina, L. ; Fujita, Yutaka ; Fukui, Y. ; Funk, S. ; Forster, A. ; Gadola, A. ; Lopez, R. Garcia ; Garczarczyk, M. ; Giglietto, N. ; Giordano, F. ; Giuliani, A. ; Glicenstein, J. ; Gnatyk, R. ; Goldoni, P. ; Grabarczyk, T. ; Graciani, R. ; Graham, J. ; Grandi, P. ; Granot, Jonathan ; Green, A. J. ; Griffiths, S. ; Gunji, S. ; Hakobyan, H. ; Hara, S. ; Hassan, T. ; Hayashida, M. ; Heller, M. ; Helo, J. C. ; Hinton, J. ; Hnatyk, B. ; Huet, J. ; Huetten, M. ; Humensky, T. B. ; Hussein, M. ; Horandel, J. ; Ikeno, Y. ; Inada, T. ; Inome, Y. ; Inoue, S. ; Inoue, T. ; Inoue, Y. ; Ioka, K. ; Iori, Maurizio ; Jacquemier, J. ; Janecek, P. ; Jankowsky, D. ; Jung, I. ; Kaaret, P. ; Katagiri, H. ; Kimeswenger, S. ; Kimura, Shigeo S. ; Knodlseder, J. ; Koch, B. ; Kocot, J. ; Kohri, K. ; Komin, N. ; Konno, Y. ; Kosack, K. ; Koyama, S. ; Kraus, Michaela ; Kubo, Hidetoshi ; Mezek, G. Kukec ; Kushida, J. ; La Palombara, N. ; Lalik, K. ; Lamanna, G. ; Landt, H. ; Lapington, J. ; Laporte, P. ; Lee, S. ; Lees, J. ; Lefaucheur, J. ; Lenain, J. -P. ; Leto, Giuseppe ; Lindfors, E. ; Lohse, T. ; Lombardi, S. ; Longo, F. ; Lopez, M. ; Lucarelli, F. ; Luque-Escamilla, Pedro Luis ; Lopez-Coto, R. ; Maccarone, M. C. ; Maier, G. ; Malaguti, G. ; Mandat, D. ; Maneva, G. ; Mangano, S. ; Marcowith, Alexandre ; Marti, J. ; Martinez, M. ; Martinez, G. ; Masuda, S. ; Maurin, G. ; Maxted, N. ; Melioli, Claudio ; Mineo, T. ; Mirabal, N. ; Mizuno, T. ; Moderski, R. ; Mohammed, M. ; Montaruli, T. ; Moralejo, A. ; Mori, K. ; Morlino, G. ; Morselli, A. ; Moulin, Emmanuel ; Mukherjee, R. ; Mundell, C. ; Muraishi, H. ; Murase, Kohta ; Nagataki, Shigehiro ; Nagayoshi, T. ; Naito, T. ; Nakajima, D. ; Nakamori, T. ; Nemmen, R. ; Niemiec, Jacek ; Nieto, D. ; Nievas-Rosillo, M. ; Nikolajuk, M. ; Nishijima, K. ; Noda, K. ; Nogues, L. ; Nosek, D. ; Novosyadlyj, B. ; Nozaki, S. ; Ohira, Yutaka ; Ohishi, M. ; Ohm, S. ; Okumura, A. ; Ong, R. A. ; Orito, R. ; Orlati, A. ; Ostrowski, M. ; Oya, I. ; Padovani, Marco ; Palacio, J. ; Palatka, M. ; Paredes, Josep M. ; Pavy, S. ; Persic, M. ; Petrucci, P. ; Petruk, Oleh ; Pisarski, A. ; Pohl, Martin ; Porcelli, A. ; Prandini, E. ; Prast, J. ; Principe, G. ; Prouza, M. ; Pueschel, Elisa ; Puelhofer, G. ; Quirrenbach, A. ; Rameez, M. ; Reimer, O. ; Renaud, M. ; Ribo, M. ; Rico, J. ; Rizi, V. ; Rodriguez, J. ; Fernandez, G. Rodriguez ; Rodriguez Vazquez, J. J. ; Romano, Patrizia ; Romeo, G. ; Rosado, J. ; Rousselle, J. ; Rowell, G. ; Rudak, B. ; Sadeh, I. ; Safi-Harb, S. ; Saito, T. ; Sakaki, N. ; Sanchez, D. ; Sangiorgi, P. ; Sano, H. ; Santander, M. ; Sarkar, S. ; Sawada, M. ; Schioppa, E. J. ; Schoorlemmer, H. ; Schovanek, P. ; Schussler, F. ; Sergijenko, O. ; Servillat, M. ; Shalchi, A. ; Shellard, R. C. ; Siejkowski, H. ; Sillanpaa, A. ; Simone, D. ; Sliusar, V. ; Sol, H. ; Stanic, S. ; Starling, R. ; Stawarz, L. ; Stefanik, S. ; Stephan, M. ; Stolarczyk, T. ; Szanecki, M. ; Szepieniec, T. ; Tagliaferri, G. ; Tajima, H. ; Takahashi, M. ; Takeda, J. ; Tanaka, M. ; Tanaka, S. ; Tejedor, L. A. ; Telezhinsky, Igor O. ; Temnikov, P. ; Terada, Y. ; Tescaro, D. ; Teshima, M. ; Testa, V. ; Thoudam, S. ; Tokanai, F. ; Torres, D. F. ; Torresi, E. ; Tosti, G. ; Townsley, C. ; Travnicek, P. ; Trichard, C. ; Trifoglio, M. ; Tsujimoto, S. ; Vagelli, V. ; Vallania, P. ; Valore, L. ; van Driel, W. ; van Eldik, C. ; Vandenbroucke, Justin ; Vassiliev, V. ; Vecchi, M. ; Vercellone, Stefano ; Vergani, S. ; Vigorito, C. ; Vorobiov, S. ; Vrastil, M. ; Vazquez Acosta, M. L. ; Wagner, S. J. ; Wagner, R. ; Wakely, S. P. ; Walter, R. ; Ward, J. E. ; Watson, J. J. ; Weinstein, A. ; White, M. ; White, R. ; Wierzcholska, A. ; Wilcox, P. ; Williams, D. A. ; Wischnewski, R. ; Wojcik, P. ; Yamamoto, T. ; Yamamoto, H. ; Yamazaki, Ryo ; Yanagita, S. ; Yang, L. ; Yoshida, T. ; Yoshida, M. ; Yoshiike, S. ; Yoshikoshi, T. ; Zacharias, M. ; Zampieri, L. ; Zanin, R. ; Zavrtanik, M. ; Zavrtanik, D. ; Zdziarski, A. ; Zech, Alraune ; Zechlin, Hannes ; Zhdanov, V. ; Ziegler, A. ; Zorn, J.
We perform simulations for future Cherenkov Telescope Array (CTA) observations of RX J1713.7-3946, a young supernova remnant (SNR) and one of the brightest sources ever discovered in very high energy (VHE) gamma rays. Special attention is paid to exploring possible spatial (anti) correlations of gamma rays with emission at other wavelengths, in particular X-rays and CO/H I emission. We present a series of simulated images of RX J1713.7-3946 for CTA based on a set of observationally motivated models for the gamma-ray emission. In these models, VHE gamma rays produced by high-energy electrons are assumed to trace the nonthermal X-ray emission observed by XMM-Newton, whereas those originating from relativistic protons delineate the local gas distributions. The local atomic and molecular gas distributions are deduced by the NANTEN team from CO and H I observations. Our primary goal is to show how one can distinguish the emission mechanism(s) of the gamma rays (i.e., hadronic versus leptonic, or a mixture of the two) through information provided by their spatial distribution, spectra, and time variation. This work is the first attempt to quantitatively evaluate the capabilities of CTA to achieve various proposed scientific goals by observing this important cosmic particle accelerator.
Furniss, A. ; Noda, K. ; Boggs, S. ; Chiang, J. ; Christensen, F. ; Craig, W. ; Giommi, P. ; Hailey, C. ; Harisson, F. ; Madejski, G. ; Nalewajko, K. ; Perri, M. ; Stern, D. ; Urry, M. ; Verrecchia, F. ; Zhang, W. ; Ahnen, M. L. ; Ansoldi, S. ; Antonelli, L. A. ; Antoranz, P. ; Babic, A. ; Banerjee, B. ; Bangale, P. ; de Almeida, U. Barres ; Barrio, J. A. ; Becerra Gonzalez, J. ; Bednarek, W. ; Bernardini, E. ; Biasuzzi, B. ; Biland, A. ; Blanch Bigas, O. ; Bonnefoy, S. ; Bonnoli, G. ; Borracci, F. ; Bretz, T. ; Carmona, E. ; Carosi, A. ; Chatterjee, A. ; Clavero, R. ; Colin, P. ; Colombo, E. ; Contreras, J. L. ; Cortina, J. ; Covino, S. ; Da Vela, P. ; Dazzi, F. ; De Angelis, A. ; De Caneva, G. ; De Lotto, B. ; de Ona Wilhelmi, E. ; Delgado Mendez, C. ; Di Pierro, F. ; Prester, Dijana Dominis ; Dorner, D. ; Doro, M. ; Einecke, S. ; Eisenacher Glawion, D. ; Elsaesser, D. ; Fernandez-Barral, A. ; Fidalgo, D. ; Fonseca, M. V. ; Font, L. ; Frantzen, K. ; Fruck, C. ; Galindo, D. ; Garcia Lopez, R. J. ; Garczarczyk, M. ; Garrido Terrats, D. ; Gaug, M. ; Giammaria, P. ; Godinovic, N. ; Gonzalez Munoz, A. ; Guberman, D. ; Hanabata, Y. ; Hayashida, M. ; Herrera, J. ; Hose, J. ; Hrupec, D. ; Hughes, G. ; Idec, W. ; Kellermann, H. ; Kodani, K. ; Konno, Y. ; Kubo, H. ; Kushida, J. ; La Barbera, A. ; Lelas, D. ; Lewandowska, N. ; Lindfors, E. ; Lombardi, S. ; Longo, F. ; Lopez, M. ; Lopez-Coto, R. ; Lopez-Oramas, A. ; Lorenz, E. ; Majumdar, P. ; Makariev, M. ; Mallot, K. ; Maneva, G. ; Manganaro, M. ; Mannheim, K. ; Maraschi, L. ; Marcote, B. ; Mariotti, M. ; Martinez, M. ; Mazin, D. ; Menzel, U. ; Miranda, J. M. ; Mirzoyan, R. ; Moralejo, A. ; Nakajima, D. ; Neustroev, V. ; Niedzwiecki, A. ; Nievas Rosillo, M. ; Nilsson, K. ; Nishijima, K. ; Orito, R. ; Overkemping, A. ; Paiano, S. ; Palacio, J. ; Palatiello, M. ; Paneque, D. ; Paoletti, R. ; Paredes, J. M. ; Paredes-Fortuny, X. ; Persic, M. ; Poutanen, J. ; Moroni, P. G. Prada ; Prandini, E. ; Puljak, I. ; Reinthal, R. ; Rhode, W. ; Ribo, M. ; Rico, J. ; Garcia, J. Rodriguez ; Saito, T. ; Saito, K. ; Satalecka, K. ; Scapin, V. ; Schultz, C. ; Schweizer, T. ; Shore, S. N. ; Sillanpaa, A. ; Sitarek, J. ; Snidaric, I. ; Sobczynska, D. ; Stamerra, A. ; Steinbring, T. ; Strzys, M. ; Takalo, L. ; Takami, H. ; Tavecchio, F. ; Temnikov, P. ; Terzic, T. ; Tescaro, D. ; Teshima, M. ; Thaele, J. ; Torres, D. F. ; Toyama, T. ; Treves, A. ; Verguilov, V. ; Vovk, I. ; Will, M. ; Zanin, R. ; Archer, A. ; Benbow, W. ; Bird, R. ; Biteau, Jonathan ; Bugaev, V. ; Cardenzana, J. V. ; Cerruti, M. ; Chen, Xuhui ; Ciupik, L. ; Connolly, M. P. ; Cui, W. ; Dickinson, H. J. ; Dumm, J. ; Eisch, J. D. ; Falcone, A. ; Feng, Q. ; Finley, J. P. ; Fleischhack, H. ; Fortin, P. ; Fortson, L. ; Gerard, L. ; Gillanders, G. H. ; Griffin, S. ; Griffiths, S. T. ; Grube, J. ; Gyuk, G. ; Hakansson, Nils ; Holder, J. ; Humensky, T. B. ; Johnson, C. A. ; Kaaret, P. ; Kertzman, M. ; Kieda, D. ; Krause, M. ; Krennrich, F. ; Lang, M. J. ; Lin, T. T. Y. ; Maier, G. ; McArthur, S. ; McCann, A. ; Meagher, K. ; Moriarty, P. ; Mukherjee, R. ; Nieto, D. ; Ong, R. A. ; Park, N. ; Petry, D. ; Pohl, Martin ; Popkow, A. ; Ragan, K. ; Ratliff, G. ; Reyes, L. C. ; Reynolds, P. T. ; Richards, G. T. ; Roache, E. ; Santander, M. ; Sembroski, G. H. ; Shahinyan, K. ; Staszak, D. ; Telezhinsky, Igor O. ; Tucci, J. V. ; Tyler, J. ; Vassiliev, V. V. ; Wakely, S. P. ; Weiner, O. M. ; Weinstein, A. ; Wilhelm, Alina ; Williams, D. A. ; Zitzer, B. ; Vince, O. ; Fuhrmann, L. ; Angelakis, E. ; Karamanavis, V. ; Myserlis, I. ; Krichbaum, T. P. ; Zensus, J. A. ; Ungerechts, H. ; Sievers, A. ; Bachev, R. ; Boettcher, Markus ; Chen, W. P. ; Damljanovic, G. ; Eswaraiah, C. ; Guver, T. ; Hovatta, T. ; Hughes, Z. ; Ibryamov, S. I. ; Joner, M. D. ; Jordan, B. ; Jorstad, S. G. ; Joshi, M. ; Kataoka, J. ; Kurtanidze, O. M. ; Kurtanidze, S. O. ; Lahteenmaki, A. ; Latev, G. ; Lin, H. C. ; Larionov, V. M. ; Mokrushina, A. A. ; Morozova, D. A. ; Nikolashvili, M. G. ; Raiteri, C. M. ; Ramakrishnan, V. ; Readhead, A. C. R. ; Sadun, A. C. ; Sigua, L. A. ; Semkov, E. H. ; Strigachev, A. ; Tammi, J. ; Tornikoski, M. ; Troitskaya, Y. V. ; Troitsky, I. S. ; Villata, M.
We report on simultaneous broadband observations of the TeV-emitting blazar Markarian 501 between 2013 April 1 and August 10, including the first detailed characterization of the synchrotron peak with Swift and NuSTAR. During the campaign, the nearby BL Lac object was observed in both a quiescent and an elevated state. The broadband campaign includes observations with NuSTAR, MAGIC, VERITAS, the Fermi Large Area Telescope, Swift X-ray Telescope and UV Optical Telescope, various ground-based optical instruments, including the GASP-WEBT program, as well as radio observations by OVRO, Metsahovi, and the F-Gamma consortium. Some of the MAGIC observations were affected by a sand layer from the Saharan desert, and had to be corrected using event-by-event corrections derived with a Light Detection and Ranging (LIDAR) facility. This is the first time that LIDAR information is used to produce a physics result with Cherenkov Telescope data taken during adverse atmospheric conditions, and hence sets a precedent for the current and future ground-based gamma-ray instruments. The NuSTAR instrument provides unprecedented sensitivity in hard X-rays, showing the source to display a spectral energy distribution (SED) between 3 and 79 keV consistent with a log-parabolic spectrum and hard X-ray variability on hour timescales. None (of the four extended NuSTAR observations) show evidence of the onset of inverse-Compton emission at hard X-ray energies. We apply a single-zone equilibrium synchrotron self-Compton (SSC) model to five simultaneous broadband SEDs. We find that the SSC model can reproduce the observed broadband states through a decrease in the magnetic field strength coinciding with an increase in the luminosity and hardness of the relativistic leptons responsible for the high-energy emission.
Abeysekara, A. U. ; Archambault, S. ; Archer, A. ; Benbow, W. ; Bird, R. ; Biteau, Jonathan ; Buchovecky, M. ; Buckley, J. H. ; Bugaev, V. ; Byrum, K. ; Cardenzana, J. V. ; Cerruti, M. ; Chen, Xuhui ; Christiansen, J. L. ; Ciupik, L. ; Connolly, M. P. ; Cui, W. ; Dickinson, H. J. ; Dumm, J. ; Eisch, J. D. ; Errando, M. ; Falcone, A. ; Feng, Q. ; Finley, J. P. ; Fleischhack, H. ; Flinders, A. ; Fortin, P. ; Fortson, L. ; Furniss, A. ; Gillanders, G. H. ; Griffin, S. ; Grube, J. ; Gyuk, G. ; Huetten, M. ; Hanna, D. ; Holder, J. ; Humensky, T. B. ; Johnson, C. A. ; Kaaret, P. ; Kar, P. ; Kelley-Hoskins, N. ; Kertzman, M. ; Kieda, D. ; Krause, M. ; Krennrich, F. ; Lang, M. J. ; Maier, G. ; McArthur, S. ; McCann, A. ; Meagher, K. ; Moriarty, P. ; Mukherjee, R. ; Nieto, D. ; Ong, R. A. ; Otte, A. N. ; Park, N. ; Pelassa, V. ; Petrashyk, A. ; Petry, D. ; Pohl, Martin ; Popkow, A. ; Pueschel, Elisa ; Quinn, J. ; Ragan, K. ; Ratliff, G. ; Reyes, L. C. ; Reynolds, P. T. ; Reynolds, K. ; Richards, G. T. ; Roache, E. ; Rulten, C. ; Santander, M. ; Sembroski, G. H. ; Shahinyan, K. ; Smith, A. W. ; Staszak, D. ; Telezhinsky, Igor O. ; Tucci, J. V. ; Tyler, J. ; Vincent, S. ; Wakely, S. P. ; Weiner, O. M. ; Weinstein, A. ; Wilhelm, Alina ; Williams, D. A. ; Zitzer, B.
We present results from multiwavelength observations of the BL Lacertae object 1ES 1741 + 196, including results in the very high energy gamma-ray regime using the Very Energetic Radiation Imaging Telescope Array System (VERITAS). The VERITAS time-averaged spectrum, measured above 180 GeV, is well modelled by a power law with a spectral index of 2.7 +/- 0.7(stat) +/- 0.2(syst). The integral flux above 180 GeV is (3.9 +/- 0.8(stat) +/- 1.0(syst)) x 10(-8) m(-2) s(-1), corresponding to 1.6 per cent of the Crab nebula flux on average. The multiwavelength spectral energy distribution of the source suggests that 1ES 1741+196 is an extreme-high-frequency-peaked BL Lacertae object. The observations analysed in this paper extend over a period of six years, during which time no strong flares were observed in any band. This analysis is therefore one of the few characterizations of a blazar in a non-flaring state.
A SEARCH FOR VERY HIGH ENERGY GAMMA RAYS FROM THE MISSING LINK BINARY PULSAR J1023+0038 WITH VERITAS
(2016)
Aliu, E. ; Archambault, S. ; Archer, A. ; Benbow, W. ; Bird, R. ; Biteau, Jonathan ; Buchovecky, M. ; Buckley, J. H. ; Bugaev, V. ; Byrum, K. ; Cardenzana, J. V. ; Cerruti, M. ; Chen, Xuhui ; Ciupik, L. ; Connolly, M. P. ; Cui, W. ; Dickinson, H. J. ; Eisch, J. D. ; Falcone, A. ; Feng, Q. ; Finley, J. P. ; Fleischhack, H. ; Flinders, A. ; Fortin, P. ; Fortson, L. ; Furniss, A. ; Gillanders, G. H. ; Griffin, S. ; Grube, J. ; Gyuk, G. ; Huetten, M. ; Hakansson, Nils ; Holder, J. ; Humensky, T. B. ; Johnson, C. A. ; Kaaret, P. ; Kar, P. ; Kelley-Hoskins, N. ; Kertzman, M. ; Kieda, D. ; Krause, M. ; Lang, M. J. ; Loo, A. ; Maier, G. ; McArthur, S. ; McCann, A. ; Meagher, K. ; Moriarty, P. ; Mukherjee, R. ; Nguyen, T. ; Nieto, D. ; Ong, R. A. ; Otte, A. N. ; Pandel, D. ; Park, N. ; Pelassa, V. ; Petrashyk, A. ; Pohl, M. ; Popkow, A. ; Pueschel, Elisa ; Quinn, J. ; Ragan, K. ; Reynolds, P. T. ; Richards, G. T. ; Roache, E. ; Rulten, C. ; Santander, M. ; Sembroski, G. H. ; Shahinyan, K. ; Smith, A. W. ; Staszak, D. ; Telezhinsky, Igor O. ; Tucci, J. V. ; Tyler, J. ; Varlotta, A. ; Vincent, S. ; Wakely, S. P. ; Weiner, O. M. ; Weinstein, A. ; Wilhelm, Alina ; Williams, D. A. ; Zitzer, B. ; Chernyakova, M. ; Roberts, M. S. E.
The binary millisecond radio pulsar PSR J1023+0038 exhibits many characteristics similar to the gamma-ray binary system PSR B1259-63/LS 2883, making it an ideal candidate for the study of high-energy nonthermal emission. It has been the subject of multiwavelength campaigns following the disappearance of the pulsed radio emission in 2013 June, which revealed the appearance of an accretion disk around the neutron star. We present the results of very high energy (VHE) gamma-ray observations carried out by the Very Energetic Radiation Imaging Telescope Array System before and after this change of state. Searches for steady and pulsed emission of both data sets yield no significant gamma-ray signal above 100 GeV, and upper limits are given for both a steady and pulsed gamma-ray flux. These upper limits are used to constrain the magnetic field strength in the shock region of the PSR J1023+0038 system. Assuming that VHE gamma rays are produced via an inverse Compton mechanism in the shock region, we constrain the shock magnetic field to be greater than similar to 2 G before the disappearance of the radio pulsar and greater than similar to 10 G afterward.
Archambault, S. ; Archer, A. ; Benbow, W. ; Bird, R. ; Biteau, Jonathan ; Buchovecky, M. ; Buckley, J. H. ; Bugaev, V. ; Byrum, K. ; Cerruti, M. ; Chen, Xuhui ; Ciupik, L. ; Connolly, M. P. ; Cui, W. ; Eisch, J. D. ; Errando, M. ; Falcone, A. ; Feng, Q. ; Finley, J. P. ; Fleischhack, H. ; Fortin, P. ; Fortson, L. ; Furniss, A. ; Gillanders, G. H. ; Griffin, S. ; Grube, J. ; Gyuk, G. ; Huetten, M. ; Hakansson, Nils ; Hanna, D. ; Holder, J. ; 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. ; Perkins, J. S. ; Pichel, A. ; Pohl, Martin ; Popkow, A. ; Pueschel, Elisa ; Quinn, J. ; Ragan, K. ; Reynolds, P. T. ; Richards, G. T. ; Roache, E. ; Rovero, A. C. ; Santander, M. ; Sembroski, G. H. ; Shahinyan, K. ; Smith, A. W. ; Staszak, D. ; Telezhinsky, Igor O. ; Tucci, J. V. ; Tyler, J. ; Vincent, S. ; Wakely, S. P. ; Weiner, O. M. ; Weinstein, A. ; Williams, D. A. ; Zitzer, B. ; Fumagalli, M. ; Prochaska, J. X.
Between the beginning of its full-scale scientific operations in 2007 and 2012, the VERITAS Cherenkov telescope array observed more than 130 blazars; of these, 26 were detected as very-high-energy (VHE; E > 100 GeV) gamma-ray sources. In this work, we present the analysis results of a sample of 114 undetected objects. The observations constitute a total live-time of similar to 570 hr. The sample includes several unidentified Fermi-Large Area Telescope (LAT) sources (located at high Galactic latitude) as well as all the sources from the second Fermi-LAT catalog that are contained within the field of view of the VERITAS observations. We have also performed optical spectroscopy measurements in order to estimate the redshift of some of these blazars that do not have spectroscopic distance estimates. We present new optical spectra from the Kast instrument on the Shane telescope at the Lick observatory for 18 blazars included in this work, which allowed for the successful measurement or constraint on the redshift of four of them. For each of the blazars included in our sample, we provide the flux upper limit in the VERITAS energy band. We also study the properties of the significance distributions and we present the result of a stacked analysis of the data set, which shows a 4s excess.
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