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Aliu, E. ; Archambault, S. ; Behera, B. ; Berger, K. ; Beilicke, M. ; Benbow, W. ; Bird, R. ; Bouvier, A. ; Bugaev, V. ; Cerruti, M. ; Chen, Xuhui ; Ciupik, L. ; Connolly, M. P. ; Cui, W. ; Dumm, J. ; Falcone, A. ; Federici, Simone ; 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. ; Krennrich, F. ; Lang, M. J. ; Maier, G. ; Majumdar, P. ; McArthur, S. ; McCann, A. ; Moriarty, P. ; Mukherjee, R. ; de Bhroithe, A. O'Faolain ; Ong, R. A. ; Otte, A. N. ; Park, N. ; Perkins, J. S. ; Pohl, Martin ; Popkow, A. ; Prokoph, H. ; Quinn, J. ; Ragan, K. ; Rajotte, J. ; Ratliff, G. ; Reynolds, P. T. ; Richards, G. T. ; Roache, E. ; Sembroski, G. H. ; Sheidaei, F. ; Skole, C. ; Smith, A. W. ; Staszak, D. ; Telezhinsky, Igor O. ; Tyler, J. ; Varlotta, A. ; Vincent, S. ; Wakely, S. P. ; Weekes, T. C. ; Weinstein, A. ; Welsing, R. ; Zajczyk, A. ; Zitzer, B.
We present the results of a multiwavelength observational campaign on the TeV binary system LS I +61 degrees 303 with the VERITAS telescope array (>200 GeV), Fermi-LAT (0.3-300 GeV), and Swift/XRT (2-10 keV). The data were taken from 2011 December through 2012 January and show a strong detection in all three wavebands. During this period VERITAS obtained 24.9 hr of quality selected livetime data in which LS I +61 degrees 303 was detected at a statistical significance of 11.9 sigma. These TeV observations show evidence for nightly variability in the TeV regime at a post-trial significance of 3.6 sigma. The combination of the simultaneously obtained TeV and X-ray fluxes do not demonstrate any evidence for a correlation between emission in the two bands. For the first time since the launch of the Fermi satellite in 2008, this TeV detection allows the construction of a detailed MeV-TeV spectral energy distribution from LS I +61 degrees 303. This spectrum shows a distinct cutoff in emission near 4 GeV, with emission seen by the VERITAS observations following a simple power-law above 200 GeV. This feature in the spectrum of LS I +61 degrees 303, obtained from overlapping observations with Fermi-LAT and VERITAS, may indicate that there are two distinct populations of accelerated particles producing the GeV and TeV emission.
Ahnen, M. L. ; Ansoldi, S. ; Antonelli, L. A. ; Antoranz, P. ; Babic, A. ; Banerjee, B. ; Bangale, P. ; de Almeida, U. Barres ; Barrio, J. A. ; Gonzalez, J. Becerra ; Bednarek, W. ; Bernardini, E. ; Berti, A. ; Biasuzzi, B. ; Biland, A. ; Blanch, O. ; Bonnefoy, S. ; Bonnoli, G. ; Borracci, F. ; Bretz, T. ; Buson, S. ; 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 Lotto, B. ; Wilhelmi, E. de Ona ; Di Pierro, F. ; Doert, M. ; Dominguez, A. ; Prester, D. Dominis ; Dorner, D. ; Doro, M. ; Einecke, S. ; Glawion, D. Eisenacher ; Elsaesser, D. ; Engelkemeier, M. ; Ramazani, V. Fallah ; Fernandez-Barral, A. ; Fidalgo, D. ; Fonseca, M. V. ; Font, L. ; Frantzen, K. ; Fruck, C. ; Galindo, D. ; Lopez, R. J. Garcia ; Garczarczyk, M. ; Terrats, D. Garrido ; Gaug, M. ; Giammaria, P. ; Godinovic, N. ; Gonzalez Munoz, A. ; Gora, D. ; Guberman, D. ; Hadasch, D. ; Hahn, A. ; Hanabata, Y. ; Hayashida, M. ; Herrera, J. ; Hose, J. ; Hrupec, D. ; Hughes, G. ; Idec, W. ; Kodani, K. ; Konno, Y. ; Kubo, H. ; Kushida, J. ; La Barbera, A. ; Lelas, D. ; Lindfors, E. ; Lombardi, S. ; Longo, F. ; Lopez, M. ; Lopez-Coto, R. ; 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. ; Moretti, E. ; Nakajima, D. ; Neustroev, V. ; Niedzwiecki, A. ; Rosillo, M. Nievas ; Nilsson, K. ; Nishijima, K. ; Noda, K. ; Nogues, L. ; Overkemping, A. ; Paiano, S. ; Palacio, J. ; Palatiello, M. ; Paneque, D. ; Paoletti, R. ; Paredes, J. M. ; Paredes-Fortuny, X. ; Pedaletti, G. ; Peresano, M. ; Perri, L. ; Persic, M. ; Poutanen, J. ; Moroni, P. G. Prada ; Prandini, E. ; Puljak, I. ; Reichardt, I. ; Rhode, W. ; Ribo, M. ; Rico, J. ; Rodriguez Garcia, J. ; Saito, T. ; Satalecka, K. ; Schroder, S. ; Schultz, C. ; Schweizer, T. ; Shore, S. N. ; Sillanpaa, A. ; Sitarek, J. ; Snidaric, I. ; Sobczynska, D. ; Stamerra, A. ; Steinbring, T. ; Strzys, M. ; Suric, T. ; Takalo, L. ; Tavecchio, F. ; Temnikov, P. ; Terzic, T. ; Tescaro, D. ; Teshima, M. ; Thaele, J. ; Torres, D. F. ; Toyama, T. ; Treves, A. ; Vanzo, G. ; Verguilov, V. ; Vovk, I. ; Ward, J. E. ; Will, M. ; Wu, M. H. ; Zanin, R. ; Abeysekara, A. U. ; Archambault, S. ; Archer, A. ; Benbow, W. ; Bird, R. ; Buchovecky, M. ; Buckley, J. H. ; Bugaev, V. ; Connolly, M. P. ; Cui, W. ; Dickinson, H. J. ; Falcone, A. ; Feng, Q. ; Finley, J. P. ; Fleischhack, H. ; Flinders, A. ; Fortson, L. ; Gillanders, G. H. ; Griffin, S. ; Grube, J. ; Huetten, M. ; Hanna, D. ; Holder, J. ; Humensky, T. B. ; Kaaret, P. ; Kar, P. ; Kelley-Hoskins, N. ; Kertzman, M. ; Kieda, D. ; Krause, M. ; Krennrich, F. ; Lang, M. J. ; Maier, G. ; McCann, A. ; Moriarty, P. ; Mukherjee, R. ; Nieto, D. ; Ong, R. A. ; Otte, N. ; Park, N. ; Perkins, J. ; Pichel, A. ; Pohl, M. ; Popkow, A. ; Pueschel, Elisa ; Quinn, J. ; Ragan, K. ; Reynolds, P. T. ; Richards, G. T. ; Roache, E. ; Rovero, A. C. ; Rulten, C. ; Sadeh, I. ; Santander, M. ; Sembroski, G. H. ; Shahinyan, K. ; Telezhinsky, Igor O. ; Tucci, J. V. ; Tyler, J. ; Wakely, S. P. ; Weinstein, A. ; Wilcox, P. ; Wilhelm, Alina ; Williams, D. A. ; Zitzer, B. ; Razzaque, S. ; Villata, M. ; Raiteri, C. M. ; Aller, H. D. ; Aller, M. F. ; Larionov, V. M. ; Arkharov, A. A. ; Blinov, D. A. ; Efimova, N. V. ; Grishina, T. S. ; Hagen-Thorn, V. A. ; Kopatskaya, E. N. ; Larionova, L. V. ; Larionova, E. G. ; Morozova, D. A. ; Troitsky, I. S. ; Ligustri, R. ; Calcidese, P. ; Berdyugin, A. ; Kurtanidze, O. M. ; Nikolashvili, M. G. ; Kimeridze, G. N. ; Sigua, L. A. ; Kurtanidze, S. O. ; Chigladze, R. A. ; Chen, W. P. ; Koptelova, E. ; Sakamoto, T. ; Sadun, A. C. ; Moody, J. W. ; Pace, C. ; Pearson, R. ; Yatsu, Y. ; Mori, Y. ; Carraminyana, A. ; Carrasco, L. ; de la Fuente, E. ; Norris, J. P. ; Smith, P. S. ; Wehrle, A. ; Gurwell, M. A. ; Zook, A. ; Pagani, C. ; Perri, M. ; Capalbi, M. ; Cesarini, A. ; Krimm, H. A. ; Kovalev, Y. Y. ; Kovalev, Yu. A. ; Ros, E. ; Pushkarev, A. B. ; Lister, M. L. ; Sokolovsky, K. V. ; Kadler, M. ; Piner, G. ; Lahteenmaki, A. ; Tornikoski, M. ; Angelakis, E. ; Krichbaum, T. P. ; Nestoras, I. ; Fuhrmann, L. ; Zensus, J. A. ; Cassaro, P. ; Orlati, A. ; Maccaferri, G. ; Leto, P. ; Giroletti, M. ; Richards, J. L. ; Max-Moerbeck, W. ; Readhead, A. C. S.
Aims. We present an extensive study of the BL Lac object Mrk 501 based on a data set collected during the multi-instrument campaign spanning from 2009 March 15 to 2009 August 1, which includes, among other instruments, MAGIC, VERITAS, Whipple 10 m, and Fermi-LAT to cover the gamma-ray range from 0.1 GeV to 20 TeV; RXTE and Swift to cover wavelengths from UV to hard X-rays; and GASP-WEBT, which provides coverage of radio and optical wavelengths. Optical polarization measurements were provided for a fraction of the campaign by the Steward and St. Petersburg observatories. We evaluate the variability of the source and interband correlations, the gamma-ray flaring activity occurring in May 2009, and interpret the results within two synchrotron self-Compton (SSC) scenarios. Methods. The multiband variability observed during the full campaign is addressed in terms of the fractional variability, and the possible correlations are studied by calculating the discrete correlation function for each pair of energy bands where the significance was evaluated with dedicated Monte Carlo simulations. The space of SSC model parameters is probed following a dedicated grid-scan strategy, allowing for a wide range of models to be tested and offering a study of the degeneracy of model-to-data agreement in the individual model parameters, hence providing a less biased interpretation than the "single-curve SSC model adjustment" typically reported in the literature. Results. We find an increase in the fractional variability with energy, while no significant interband correlations of flux changes are found on the basis of the acquired data set. The SSC model grid-scan shows that the flaring activity around May 22 cannot be modeled adequately with a one-zone SSC scenario (using an electron energy distribution with two breaks), while it can be suitably described within a two (independent) zone SSC scenario. Here, one zone is responsible for the quiescent emission from the averaged 4.5-month observing period, while the other one, which is spatially separated from the first, dominates the flaring emission occurring at X-rays and very-high-energy (> 100 GeV, VHE) gamma-rays. The flaring activity from May 1, which coincides with a rotation of the electric vector polarization angle (EVPA), cannot be satisfactorily reproduced by either a one-zone or a two-independent-zone SSC model, yet this is partially affected by the lack of strictly simultaneous observations and the presence of large flux changes on sub-hour timescales (detected at VHE gamma rays). Conclusions. The higher variability in the VHE emission and lack of correlation with the X-ray emission indicate that, at least during the 4.5-month observing campaign in 2009, the highest energy (and most variable) electrons that are responsible for the VHE gamma rays do not make a dominant contribution to the similar to 1 keV emission. Alternatively, there could be a very variable component contributing to the VHE gamma-ray emission in addition to that coming from the SSC scenario. The studies with our dedicated SSC grid-scan show that there is some degeneracy in both the one-zone and the two-zone SSC scenarios probed, with several combinations of model parameters yielding a similar model-to-data agreement, and some parameters better constrained than others. The observed gamma-ray flaring activity, with the EVPA rotation coincident with the first gamma-ray flare, resembles those reported previously for low frequency peaked blazars, hence suggesting that there are many similarities in the flaring mechanisms of blazars with different jet properties.
Archer, A. ; Benbow, W. ; Bird, R. ; Brose, Robert ; Buchovecky, M. ; Bugaev, V. ; Connolly, M. P. ; Cui, W. ; Daniel, M. K. ; Falcone, A. ; Feng, Q. ; Finley, J. P. ; Fleischhack, H. ; Fortson, L. ; Furniss, A. ; Hanna, D. ; Hervet, O. ; Holder, J. ; Hughes, G. ; Humensky, T. B. ; Hutten, M. ; Johnson, C. A. ; Kaaret, P. ; Kelley-Hoskins, N. ; Kieda, D. ; Krause, M. ; Krennrich, F. ; Kumar, S. ; Lang, M. J. ; Maier, G. ; McArthur, S. ; Moriarty, P. ; Mukherjee, R. ; Nieto, D. ; Ong, R. A. ; Otte, A. N. ; Park, N. ; Petrashyk, A. ; Pohl, Martin ; Popkow, A. ; Pueschel, Elisa ; Quinn, J. ; Ragan, K. ; Reynolds, P. T. ; Richards, G. T. ; Roache, E. ; Rulten, C. ; Sadeh, I. ; Tyler, J. ; Wakely, S. P. ; Weiner, O. M. ; Wilcox, P. ; Wilhelm, Alina ; Williams, D. A. ; Wissel, S. A. ; Zitzer, B.
We present a new measurement of the energy spectrum of iron nuclei in cosmic rays from 20 TeV to 500 TeV; The measurement makes use of a template-based analysis method, which, for the first time, is applied to the energy reconstruction of iron-induced air showers recorded by the VERITAS array of imaging atmospheric Cherenkov telescopes. The event selection makes use of the direct Cherenkov light which is emitted by charged particles before the first interaction, as well as other parameters related to the shape of the recorded air shower images. The measured spectrum is well described by a power law dF/dE = f(0) center dot (E/E-0)(-gamma) over the full energy range, with gamma = 2.82 +/- 0.30(stat)(-0.27)(+0.24)(syst) and f(0) = (4.82 +/- 0.98(stat)(-2.70)(+2.12)(syst)) x 10(-7) m(-2) s(-1) TeV-1 sr(-1) at E-0 = 50 TeV, with no indication of a cutoff or spectral break. The measured differential flux is compatible with previous results, with improved statistical uncertainty at the highest energies.
Abeysekara, A. U. ; Archer, A. ; Benbow, Wystan ; Bird, Ralph ; Brill, A. ; Brose, Robert ; Buchovecky, M. ; Calderon-Madera, D. ; Christiansen, J. L. ; Cui, W. ; Daniel, M. K. ; Falcone, A. ; Feng, Q. ; Fernandez-Alonso, M. ; Finley, J. P. ; Fortson, Lucy ; Furniss, Amy ; Gent, A. ; Giuri, C. ; Gueta, O. ; Hanna, David ; Hassan, T. ; Hervet, Oliver ; Holder, J. ; Hughes, G. ; Humensky, T. B. ; Johnson, Caitlin A. ; Kaaret, P. ; Kertzman, M. ; Kieda, David ; Krause, Maria ; Krennrich, F. ; Kumar, S. ; Lang, M. J. ; Maier, Gernot ; Moriarty, P. ; Mukherjee, Reshmi ; Nievas-Rosillo, M. ; Ong, R. A. ; Pfrang, Konstantin Johannes ; Pohl, Martin ; Prado, R. R. ; Pueschel, Elisa ; Quinn, J. ; Ragan, K. ; Reynolds, P. T. ; Ribeiro, D. ; Richards, G. T. ; Roache, E. ; Rovero, A. C. ; Sadeh, Iftach ; Santander, M. ; Sembroski, G. H. ; Shahinyan, Karlen ; Sushch, Iurii ; Svraka, T. ; Weinstein, A. ; Wells, R. M. ; Wilcox, Patrick ; Wilhelm, Alina ; Williams, David Arnold ; Williamson, T. J. ; Zitzer, B.
The extragalactic background light (EBL), a diffuse photon field in the optical and infrared range, is a record of radiative processes over the universe?s history. Spectral measurements of blazars at very high energies (>100 GeV) enable the reconstruction of the spectral energy distribution (SED) of the EBL, as the blazar spectra are modified by redshift- and energy-dependent interactions of the gamma-ray photons with the EBL. The spectra of 14 VERITAS-detected blazars are included in a new measurement of the EBL SED that is independent of EBL SED models. The resulting SED covers an EBL wavelength range of 0.56?56 ?m, and is in good agreement with lower limits obtained by assuming that the EBL is entirely due to radiation from cataloged galaxies.
Archer, A. ; Benbow, W. ; Bird, R. ; Brose, Robert ; Buchovecky, M. ; Buckley, J. H. ; Bugaev, V. ; Connolly, M. P. ; Cui, W. ; Daniel, M. K. ; Feng, Q. ; Finley, J. P. ; Fortson, L. ; Furniss, A. ; Gillanders, G. ; Huetten, M. ; 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. ; Lin, T. T. Y. ; Maier, G. ; McArthur, S. ; Moriarty, P. ; Mukherjee, R. ; Ong, R. A. ; Otte, A. N. ; Petrashyk, A. ; Pohl, M. ; Pueschel, Elisa ; Quinn, J. ; Ragan, K. ; Reynolds, P. T. ; Richards, G. T. ; Roache, E. ; Rulten, C. ; Sadeh, I. ; Santander, M. ; Sembroski, G. H. ; Staszak, D. ; Sushch, I. ; Wakely, S. P. ; Wells, R. M. ; Wilcox, P. ; Wilhelm, Alina ; Williams, D. A. ; Williamson, T. J. ; Zitzer, B.
Cosmic-ray electrons and positrons (CREs) at GeV-TeV energies are a unique probe of our local Galactic neighborhood. CREs lose energy rapidly via synchrotron radiation and inverse-Compton scattering processes while propagating within the Galaxy, and these losses limit their propagation distance. For electrons with TeV energies, the limit is on the order of a kiloparsec. Within that distance, there are only a few known astrophysical objects capable of accelerating electrons to such high energies. It is also possible that the CREs are the products of the annihilation or decay of heavy dark matter (DM) particles. VERITAS, an array of imaging air Cherenkov telescopes in southern Arizona, is primarily utilized for gamma-ray astronomy but also simultaneously collects CREs during all observations. We describe our methods of identifying CREs in VERITAS data and present an energy spectrum, extending from 300 GeV to 5 TeV, obtained from approximately 300 hours of observations. A single power-law fit is ruled out in VERITAS data. We find that the spectrum of CREs is consistent with a broken power law, with a break energy at 710 +/- 40(stat) +/- 140(syst) GeV.
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, Alexandre ; Marx, R. ; Maurin, G. ; Maxted, N. ; Mayer, M. ; McComb, T. J. L. ; Mehault, J. ; Menzler, U. ; Meyer, M. ; Moderski, R. ; Mohamed, M. ; Moulin, Emmanuel ; 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, Andrea ; 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.
Aliu, E. ; Archambault, S. ; Arlen, T. ; Aune, T. ; Beilicke, M. ; Benbow, W. ; Bird, R. ; Bouvier, A. ; Buckley, J. H. ; Bugaev, V. ; Cesarini, A. ; Ciupik, L. ; Connolly, M. P. ; Cui, W. ; Dumm, J. ; Errando, M. ; Falcone, A. ; Federici, Simone ; Feng, Q. ; Finley, J. P. ; Fortin, P. ; Fortson, L. ; Furniss, A. ; Galante, N. ; Gerard, L. ; Gillanders, G. H. ; Griffin, S. ; 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. ; McArthur, S. ; McCann, A. ; Moriarty, P. ; Mukherjee, R. ; Nieto, D. ; De Bhroithe, A. O'Faolain ; Ong, R. A. ; Orr, M. ; Otte, A. N. ; Park, N. ; Perkins, J. S. ; Pohl, Martin ; Popkow, A. ; Prokoph, H. ; Quinn, J. ; Ragan, K. ; Reyes, L. C. ; Reynolds, P. T. ; Richards, G. T. ; Roache, E. ; Saxon, D. B. ; Sembroski, G. H. ; Skole, C. ; Smith, A. W. ; Soares-Furtado, M. ; Staszak, D. ; Telezhinsky, Igor O. ; Tesic, G. ; Theiling, M. ; Varlotta, A. ; Vassiliev, V. V. ; Vincent, S. ; Wakely, S. P. ; Weekes, T. C. ; Weinstein, A. ; Welsing, R. ; Williams, D. A. ; Zitzer, B. ; Böttcher, Markus ; Fumagalli, M. ; Jadhav, J.
We report on VERITAS observations of the BL Lac object B2 1215+30 between 2008 and 2012. During this period, the source was detected at very high energies (VHEs; E > 100 GeV) by VERITAS with a significance of 8.9s and showed clear variability on timescales larger than months. In 2011, the source was found to be in a relatively bright state and a power-law fit to the differential photon spectrum yields a spectral index of 3.6 +/- 0.4(stat) +/- 0.3(syst) with an integral flux above 200 GeV of (8.0 +/- 0.9(stat) +/- 3.2(syst)) x 10(-12) cm(-2) s(-1). No short term variability could be detected during the bright state in 2011. Multi-wavelength data were obtained contemporaneously with the VERITAS observations in 2011 and cover optical (Super-LOTIS, MDM, Swift/UVOT), X-ray (Swift/XRT), and gamma-ray (Fermi-LAT) frequencies. These were used to construct the spectral energy distribution (SED) of B2 1215+30. A one-zone leptonic model is used to model the blazar emission and the results are compared to those of MAGIC from early 2011 and other VERITAS-detected blazars. The SED can be reproduced well with model parameters typical for VHE-detected BL Lac objects.
Aliu, E. ; Archambault, S. ; Aune, T. ; Behera, B. ; Beilicke, M. ; Benbow, W. ; Berger, K. ; Bird, R. ; Buckley, J. H. ; Bugaev, V. ; Cardenzana, J. V. ; Cerruti, M. ; Chen, Xuhui ; Ciupik, L. ; Collins-Hughes, E. ; Connolly, M. P. ; Cui, W. ; Dumm, J. ; Dwarkadas, Vikram V. ; Errando, M. ; Falcone, A. ; Federici, Simone ; Feng, Q. ; Finley, J. P. ; Fleischhack, H. ; Fortin, P. ; Fortson, L. ; Furniss, A. ; Galante, N. ; Gall, D. ; 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. ; Krennrich, F. ; Kumar, S. ; Lang, M. J. ; Madhavan, A. S. ; Maier, G. ; McCann, A. J. ; Meagher, K. ; Millis, J. ; Moriarty, P. ; Mukherjee, R. ; Nieto, D. ; Ong, R. A. ; Otte, A. N. ; Pandel, D. ; Park, N. ; Pohl, Martin ; Popkow, A. ; Prokoph, H. ; Quinn, J. ; Ragan, K. ; Rajotte, J. ; Ratliff, G. ; Reyes, L. C. ; Reynolds, P. T. ; Richards, G. T. ; Roache, E. ; Rousselle, J. ; Sembroski, G. H. ; Shahinyan, K. ; Sheidaei, F. ; Smith, A. W. ; Staszak, D. ; Telezhinsky, Igor O. ; Tsurusaki, K. ; Tucci, J. V. ; Tyler, J. ; Varlotta, A. ; Vassiliev, V. V. ; Vincent, S. ; Wakely, S. P. ; Ward, J. E. ; Weinstein, A. ; Welsing, R. ; Wilhelm, Alina
We report on deep observations of the extended TeV gamma-ray source MGRO J1908+06 made with the VERITAS very high energy gamma-ray observatory. Previously, the TeV emission has been attributed to the pulsar wind nebula (PWN) of the Fermi-LAT pulsar PSR J1907+0602. We detect MGRO J1908+06 at a significance level of 14 standard deviations (14 sigma) and measure a photon index of 2.20 +/- 0.10(stat) +/- 0.20(sys). The TeV emission is extended, covering the region near PSR J1907+0602 and also extending toward SNR G40.5-0.5. When fitted with a two-dimensional Gaussian, the intrinsic extension has a standard deviation of sigma(src) = 0 degrees.44 +/- 0 degrees.02. In contrast to other TeV PWNe of similar age in which the TeV spectrum softens with distance from the pulsar, the TeV spectrum measured near the pulsar location is consistent with that measured at a position near the rim of G40.5-0.5, 0 degrees.33 away.
Aliu, E. ; Archambault, S. ; Arlen, T. ; Aune, T. ; Barnacka, Anna ; Beilicke, M. ; Benbow, W. ; Berger, K. ; Bird, R. ; Bouvier, A. ; Buckley, J. H. ; Bugaev, V. ; Cerruti, M. ; Chen, X. ; Ciupik, L. ; Collins-Hughes, E. ; Connolly, M. P. ; Cui, W. ; Dumm, J. ; Eisch, J. D. ; Falcone, A. ; Federici, S. ; Feng, Q. ; Finley, J. P. ; Fleischhack, H. ; Fortin, P. ; Fortson, L. ; Furniss, A. ; Galante, N. ; Gillanders, G. H. ; Griffin, S. ; Griffiths, S. T. ; Grube, J. ; Gyuk, G. ; Hakansson, N. ; Hanna, D. ; Holder, J. ; Hughes, G. ; Hughes, Z. ; Humensky, T. B. ; Johnson, C. A. ; Kaaret, P. ; Kar, P. ; Kertzman, M. ; Khassen, Y. ; Kieda, D. ; Krawczynski, H. ; Krennrich, F. ; Lang, M. J. ; Madhavan, A. S. ; Majumdar, P. ; McArthur, S. ; McCann, A. ; Meagher, K. ; Millis, J. ; Moriarty, P. ; Mukherjee, R. ; Nelson, T. ; 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. ; Sadun, A. ; Santander, M. ; Sembroski, G. H. ; Shahinyan, K. ; Sheidaei, F. ; Smith, A. W. ; Staszak, D. ; Telezhinsky, Igor O. ; Theiling, M. ; Tyler, J. ; Varlotta, A. ; Vassiliev, V. V. ; Vincent, S. ; Wakely, S. P. ; Weekes, T. C. ; Weinstein, A. ; Welsing, R. ; Wilhelm, Alina ; Williams, D. A. ; Zitzer, B. ; Boettcher, Markus ; Fumagalli, M.
We summarize broadband observations of the TeV-emitting blazar 1ES 1959+650, including optical R-band observations by the robotic telescopes Super-LOTIS and iTelescope, UV observations by Swift Ultraviolet and Optical Telescope, X-ray observations by the Swift X-ray Telescope, high-energy gamma-ray observations with the Fermi Large Area Telescope, and very-high-energy (VHE) gamma-ray observations by VERITAS above 315 GeV, all taken between 2012 April 17 and 2012 June 1 (MJD 56034 and 56079). The contemporaneous variability of the broadband spectral energy distribution is explored in the context of a simple synchrotron self Compton (SSC) model. In the SSC emission scenario, we find that the parameters required to represent the high state are significantly different than those in the low state. Motivated by possible evidence of gas in the vicinity of the blazar, we also investigate a reflected emission model to describe the observed variability pattern. This model assumes that the non-thermal emission from the jet is reflected by a nearby cloud of gas, allowing the reflected emission to re-enter the blob and produce an elevated gamma-ray state with no simultaneous elevated synchrotron flux. The model applied here, although not required to explain the observed variability pattern, represents one possible scenario which can describe the observations. As applied to an elevated VHE state of 66% of the Crab Nebula flux, observed on a single night during the observation period, the reflected emission scenario does not support a purely leptonic non-thermal emission mechanism. The reflected emission model does, however, predict a reflected photon field with sufficient energy to enable elevated gamma-ray emission via pion production with protons of energies between 10 and 100 TeV.
Introducing the CTA concept
(2013)
Acharya, B. S. ; Actis, M. ; Aghajani, T. ; Agnetta, G. ; Aguilar, J. ; Aharonian, Felix A. ; Ajello, M. ; Akhperjanian, A. G. ; Alcubierre, M. ; Aleksic, J. ; Alfaro, R. ; Aliu, E. ; Allafort, A. J. ; Allan, D. ; Allekotte, I. ; Amato, E. ; Anderson, J. ; Angüner, Ekrem Oǧuzhan ; Antonelli, L. A. ; Antoranz, P. ; Aravantinos, A. ; Arlen, T. ; Armstrong, T. ; Arnaldi, H. ; Arrabito, L. ; Asano, K. ; Ashton, T. ; Asorey, H. G. ; Awane, Y. ; Baba, H. ; Babic, A. ; Baby, N. ; Baehr, J. ; Bais, A. ; Baixeras, C. ; Bajtlik, S. ; Balbo, M. ; Balis, D. ; Balkowski, C. ; Bamba, A. ; Bandiera, R. ; Barber, A. ; Barbier, C. ; Barcelo, M. ; Barnacka, Anna ; Barnstedt, Jürgen ; Barres de Almeida, U. ; Barrio, J. A. ; Basili, A. ; Basso, S. ; Bastieri, D. ; Bauer, C. ; Baushev, Anton N. ; Becerra Gonzalez, J. ; Becherini, Yvonne ; Bechtol, K. C. ; Tjus, J. Becker ; Beckmann, Volker ; Bednarek, W. ; Behera, B. ; Belluso, M. ; Benbow, W. ; Berdugo, J. ; Berger, K. ; Bernard, F. ; Bernardino, T. ; Bernlöhr, K. ; Bhat, N. ; Bhattacharyya, S. ; Bigongiari, C. ; Biland, A. ; Billotta, S. ; Bird, T. ; Birsin, E. ; Bissaldi, E. ; Biteau, Jonathan ; Bitossi, M. ; Blake, S. ; Blanch Bigas, O. ; Blasi, P. ; Bobkov, A. A. ; Boccone, V. ; Boettcher, Markus ; Bogacz, L. ; Bogart, J. ; Bogdan, M. ; Boisson, Catherine ; Boix Gargallo, J. ; Bolmont, J. ; Bonanno, G. ; Bonardi, A. ; Bonev, T. ; Bonifacio, P. ; Bonnoli, G. ; Bordas, Pol ; Borgland, A. W. ; Borkowski, Janett ; Bose, R. ; Botner, O. ; Bottani, A. ; Bouchet, L. ; Bourgeat, M. ; Boutonnet, C. ; Bouvier, A. ; Brau-Nogue, S. ; Braun, I. ; Bretz, T. ; Briggs, M. S. ; Bringmann, T. ; Brook, P. ; Brun, Pierre ; Brunetti, L. ; Buanes, T. ; Buckley, J. H. ; Buehler, R. ; Bugaev, V. ; Bulgarelli, A. ; Bulik, Tomasz ; Busetto, G. ; Buson, S. ; Byrum, K. ; Cailles, M. ; Cameron, R. A. ; Camprecios, J. ; Canestrari, R. ; Cantu, S. ; Capalbi, M. ; Caraveo, P. A. ; Carmona, E. ; Carosi, A. ; Carr, John ; Carton, P. H. ; Casanova, Sabrina ; Casiraghi, M. ; Catalano, O. ; Cavazzani, S. ; Cazaux, S. ; Cerruti, M. ; Chabanne, E. ; Chadwick, Paula M. ; Champion, C. ; Chen, Andrew ; Chiang, J. ; Chiappetti, L. ; Chikawa, M. ; Chitnis, V. R. ; Chollet, F. ; Chudoba, J. ; Cieslar, M. ; Cillis, A. N. ; Cohen-Tanugi, J. ; Colafrancesco, Sergio ; Colin, P. ; Calome, J. ; Colonges, S. ; Compin, M. ; Conconi, P. ; Conforti, V. ; Connaughton, V. ; Conrad, Jan ; Contreras, J. L. ; Coppi, P. ; Corona, P. ; Corti, D. ; Cortina, J. ; Cossio, L. ; Costantini, H. ; Cotter, G. ; Courty, B. ; Couturier, S. ; Covino, S. ; Crimi, G. ; Criswell, S. J. ; Croston, J. ; Cusumano, G. ; Dafonseca, M. ; Dale, O. ; Daniel, M. ; Darling, J. ; Davids, I. ; Dazzi, F. ; De Angelis, A. ; De Caprio, V. ; De Frondat, F. ; de Gouveia Dal Pino, E. M. ; de la Calle, I. ; De La Vega, G. A. ; Lopez, R. de los Reyes ; De Lotto, B. ; De Luca, A. ; de Mello Neto, J. R. T. ; de Naurois, M. ; de Oliveira, Y. ; de Ona Wilhelmi, E. ; de Souza, V. ; Decerprit, G. ; Decock, G. ; Deil, C. ; Delagnes, E. ; Deleglise, G. ; Delgado, C. ; Della Volpe, D. ; Demange, P. ; Depaola, G. ; Dettlaff, A. ; Di Paola, A. ; Di Pierro, F. ; Diaz, C. ; Dick, J. ; Dickherber, R. ; Dickinson, H. ; Diez-Blanco, V. ; Digel, S. ; Dimitrov, D. ; Disset, G. ; Djannati-Ataï, A. ; Doert, M. ; Dohmke, M. ; Domainko, W. ; Prester, Dijana Dominis ; Donat, A. ; Dorner, D. ; Doro, M. ; Dournaux, J-L. ; Drake, G. ; Dravins, D. ; Drury, L. ; Dubois, F. ; Dubois, R. ; Dubus, G. ; Dufour, C. ; Dumas, D. ; Dumm, J. ; Durand, D. ; Dyks, J. ; Dyrda, M. ; Ebr, J. ; Edy, E. ; Egberts, Kathrin ; Eger, P. ; Einecke, S. ; Eleftheriadis, C. ; Elles, S. ; Emmanoulopoulos, D. ; Engelhaupt, D. ; Enomoto, R. ; Ernenwein, J-P ; Errando, M. ; Etchegoyen, A. ; Evans, P. ; Falcone, A. ; Fantinel, D. ; Farakos, K. ; Farnier, C. ; Fasola, G. ; Favill, B. ; Fede, E. ; Federici, S. ; Fegan, S. ; Feinstein, F. ; Ferenc, D. ; Ferrando, P. ; Fesquet, M. ; Fiasson, A. ; Fillin-Martino, E. ; Fink, D. ; Finley, C. ; Finley, J. P. ; Fiorini, M. ; Firpo Curcoll, R. ; Flores, H. ; Florin, D. ; Focke, W. ; Foehr, C. ; Fokitis, E. ; Font, L. ; Fontaine, G. ; Fornasa, M. ; Foerster, A. ; Fortson, L. ; Fouque, N. ; Franckowiak, A. ; Fransson, C. ; Fraser, G. ; Frei, R. ; Albuquerque, I. F. M. ; Fresnillo, L. ; Fruck, C. ; Fujita, Y. ; Fukazawa, Y. ; Fukui, Y. ; Funk, S. ; Gaebele, W. ; Gabici, S. ; Gabriele, R. ; Gadola, A. ; Galante, N. ; Gall, D. ; Gallant, Y. ; Gamez-Garcia, J. ; Garcia, B. ; Garcia Lopez, R. ; Gardiol, D. ; Garrido, D. ; Garrido, L. ; Gascon, D. ; Gaug, M. ; Gaweda, J. ; Gebremedhin, L. ; Geffroy, N. ; Gerard, L. ; Ghedina, A. ; Ghigo, M. ; Giannakaki, E. ; Gianotti, F. ; Giarrusso, S. ; Giavitto, G. ; Giebels, B. ; Gika, V. ; Giommi, P. ; Girard, N. ; Giro, E. ; Giuliani, A. ; Glanzman, T. ; Glicenstein, J. -F. ; Godinovic, N. ; Golev, V. ; Gomez Berisso, M. ; Gomez-Ortega, J. ; Gonzalez, M. M. ; Gonzalez, A. ; Gonzalez, F. ; Gonzalez Munoz, A. ; Gothe, K. S. ; Gougerot, M. ; Graciani, R. ; Grandi, P. ; Granena, F. ; Granot, J. ; Grasseau, G. ; Gredig, R. ; Green, A. ; Greenshaw, T. ; Gregoire, T. ; Grimm, O. ; Grube, J. ; Grudzinska, M. ; Gruev, V. ; Gruenewald, S. ; Grygorczuk, J. ; Guarino, V. ; Gunji, S. ; Gyuk, G. ; Hadasch, D. ; Hagiwara, R. ; Hahn, J. ; Hakansson, N. ; Hallgren, A. ; Hamer Heras, N. ; Hara, S. ; Hardcastle, M. J. ; Harris, J. ; Hassan, T. ; Hatanaka, K. ; Haubold, T. ; Haupt, A. ; Hayakawa, T. ; Hayashida, M. ; Heller, R. ; Henault, F. ; Henri, G. ; Hermann, G. ; Hermel, R. ; Herrero, A. ; Hidaka, N. ; Hinton, J. ; Hoffmann, D. ; Hofmann, W. ; Hofverberg, P. ; Holder, J. ; Horns, D. ; Horville, D. ; Houles, J. ; Hrabovsky, M. ; Hrupec, D. ; Huan, H. ; Huber, B. ; Huet, J. -M. ; Hughes, G. ; Humensky, T. B. ; Huovelin, J. ; Ibarra, A. ; Illa, J. M. ; Impiombato, D. ; Incorvaia, S. ; Inoue, S. ; Inoue, Y. ; Ioka, K. ; Ismailova, E. ; Jablonski, C. ; Jacholkowska, A. ; Jamrozy, M. ; Janiak, M. ; Jean, P. ; Jeanney, C. ; Jimenez, J. J. ; Jogler, T. ; Johnson, T. ; Journet, L. ; Juffroy, C. ; Jung, I. ; Kaaret, P. ; Kabuki, S. ; Kagaya, M. ; Kakuwa, J. ; Kalkuhl, C. ; Kankanyan, R. ; Karastergiou, A. ; Kaercher, K. ; Karczewski, M. ; Karkar, S. ; Kasperek, Aci. ; Kastana, D. ; Katagiri, H. ; Kataoka, J. ; Katarzynski, K. ; Katz, U. ; Kawanaka, N. ; Kellner-Leidel, B. ; Kelly, H. ; Kendziorra, E. ; Khelifi, B. ; Kieda, D. B. ; Kifune, T. ; Kihm, T. ; Kishimoto, T. ; Kitamoto, K. ; Kluzniak, W. ; Knapic, C. ; Knapp, J. w ; Knoedlseder, J. ; Koeck, F. ; Kocot, J. ; Kodani, K. ; Koehne, J. -H. ; Kohri, K. ; Kokkotas, K. ; Kolitzus, D. ; Komin, N. ; Kominis, I. ; Konno, Y. ; Koeppel, H. ; Korohoda, P. ; Kosack, K. ; Koss, G. ; Kossakowski, R. ; Kostka, P. ; Koul, R. ; Kowal, G. ; Koyama, S. ; Koziol, J. ; Kraehenbuehl, T. ; Krause, J. ; Krawzcynski, H. ; Krennrich, F. ; Krepps, A. ; Kretzschmann, A. ; Krobot, R. ; Krueger, P. ; Kubo, H. ; Kudryavtsev, V. A. ; Kushida, J. ; Kuznetsov, A. ; La Barbera, A. ; La Palombara, N. ; La Parola, V. ; La Rosa, G. ; Lacombe, K. ; Lamanna, G. ; Lande, J. ; Languignon, D. ; Lapington, J. ; Laporte, P. ; Lavalley, C. ; Le Flour, T. ; Le Padellec, A. ; Lee, S. -H. ; Lee, W. H. ; Leigui de Oliveira, M. A. ; Lelas, D. ; Lenain, J. -P. ; Leopold, D. J. ; Lerch, T. ; Lessio, L. ; Lieunard, B. ; Lindfors, E. ; Liolios, A. ; Lipniacka, A. ; Lockart, H. ; Lohse, T. ; Lombardi, S. ; Lopatin, A. ; Lopez, M. ; Lopez-Coto, R. ; Lopez-Oramas, A. ; Lorca, A. ; Lorenz, E. ; Lubinski, P. ; Lucarelli, F. ; Luedecke, H. ; Ludwin, J. ; Luque-Escamilla, P. L. ; Lustermann, W. ; Luz, O. ; Lyard, E. ; Maccarone, M. C. ; Maccarone, T. J. ; Madejski, G. M. ; Madhavan, A. ; Mahabir, M. ; Maier, G. ; Majumdar, P. ; Malaguti, G. ; Maltezos, S. ; Manalaysay, A. ; Mancilla, A. ; Mandat, D. ; Maneva, G. ; Mangano, A. ; Manigot, P. ; Mannheim, K. ; Manthos, I. ; Maragos, N. ; Marcowith, Alexandre ; Mariotti, M. ; Marisaldi, M. ; Markoff, S. ; Marszalek, A. ; Martens, C. ; Marti, J. ; Martin, J-M. ; Martin, P. ; Martinez, G. ; Martinez, F. ; Martinez, M. ; Masserot, A. ; Mastichiadis, A. ; Mathieu, A. ; Matsumoto, H. ; Mattana, F. ; Mattiazzo, S. ; Maurin, G. ; Maxfield, S. ; Maya, J. ; Mazin, D. ; Mc Comb, L. ; McCubbin, N. ; McHardy, I. ; McKay, R. ; Medina, C. ; Melioli, C. ; Melkumyan, D. ; Mereghetti, S. ; Mertsch, P. ; Meucci, M. ; Michalowski, J. ; Micolon, P. ; Mihailidis, A. ; Mineo, T. ; Minuti, M. ; Mirabal, N. ; Mirabel, F. ; Miranda, J. M. ; Mirzoyan, R. ; Mizuno, T. ; Moal, B. ; Moderski, R. ; Mognet, I. ; Molinari, E. ; Molinaro, M. ; Montaruli, T. ; Monteiro, I. ; Moore, P. ; Moralejo Olaizola, A. ; Mordalska, M. ; Morello, C. ; Mori, K. ; Mottez, F. ; Moudden, Y. ; Moulin, Emmanuel ; Mrusek, I. ; Mukherjee, R. ; Munar-Adrover, P. ; Muraishi, H. ; Murase, K. ; Murphy, A. ; Nagataki, S. ; Naito, T. ; Nakajima, D. ; Nakamori, T. ; Nakayama, K. ; Naumann, C. L. ; Naumann, D. ; Naumann-Godo, M. ; Nayman, P. ; Nedbal, D. ; Neise, D. ; Nellen, L. ; Neustroev, V. ; Neyroud, N. ; Nicastro, L. ; Nicolau-Kuklinski, J. ; Niedzwiecki, A. ; Niemiec, J. ; Nieto, D. ; Nikolaidis, A. ; Nishijima, K. ; Nolan, S. ; Northrop, R. ; Nosek, D. ; Nowak, N. ; Nozato, A. ; O'Brien, P. ; Ohira, Y. ; Ohishi, M. ; Ohm, S. ; Ohoka, H. ; Okuda, T. ; Okumura, A. ; Olive, J. -F. ; Ong, R. A. ; Orito, R. ; Orr, M. ; Osborne, J. ; Ostrowski, M. ; Otero, L. A. ; Otte, N. ; Ovcharov, E. ; Oya, I. ; Ozieblo, A. ; Padilla, L. ; Paiano, S. ; Paillot, D. ; Paizis, A. ; Palanque, S. ; Palatka, M. ; Pallota, J. ; Panagiotidis, K. ; Panazol, J. -L. ; Paneque, D. ; Panter, M. ; Paoletti, R. ; Papayannis, Alexandros ; Papyan, G. ; Paredes, J. M. ; Pareschi, G. ; Parks, G. ; Parraud, J. -M. ; Parsons, D. ; Arribas, M. Paz ; Pech, M. ; Pedaletti, G. ; Pelassa, V. ; Pelat, D. ; Perez, M. D. C. ; Persic, M. ; Petrucci, P-O ; Peyaud, B. ; Pichel, A. ; Pita, S. ; Pizzolato, F. ; Platos, L. ; Platzer, R. ; Pogosyan, L. ; Pohl, M. ; Pojmanski, G. ; Ponz, J. D. ; Potter, W. ; Poutanen, J. ; Prandini, E. ; Prast, J. ; Preece, R. ; Profeti, F. ; Prokoph, H. ; Prouza, M. ; Proyetti, M. ; Puerto-Gimenez, I. ; Puehlhofer, G. ; Puljak, I. ; Punch, M. ; Pyziol, R. ; Quel, E. J. ; Quinn, J. ; Quirrenbach, A. ; Racero, E. ; Rajda, P. J. ; Ramon, P. ; Rando, R. ; Rannot, R. C. ; Rataj, M. ; Raue, M. ; Reardon, P. ; Reimann, O. ; Reimer, A. ; Reimer, O. ; Reitberger, K. ; Renaud, M. ; Renner, S. ; Reville, B. ; Rhode, W. ; Ribo, M. ; Ribordy, M. ; Richer, M. G. ; Rico, J. ; Ridky, J. ; Rieger, F. ; Ringegni, P. ; Ripken, J. ; Ristori, P. R. ; Riviere, A. ; Rivoire, S. ; Rob, L. ; Roeser, U. ; Rohlfs, R. ; Rojas, G. ; Romano, Patrizia ; Romaszkan, W. ; Romero, G. E. ; Rosen, S. ; Lees, S. Rosier ; Ross, D. ; Rouaix, G. ; Rousselle, J. ; Rousselle, S. ; Rovero, A. C. ; Roy, F. ; Royer, S. ; Rudak, B. ; Rulten, C. ; Rupinski, M. ; Russo, F. ; Ryde, F. ; Sacco, B. ; Saemann, E. O. ; Saggion, A. ; Safiakian, V. ; Saito, K. ; Saito, T. ; Saito, Y. ; Sakaki, N. ; Sakonaka, R. ; Salini, A. ; Sanchez, F. ; Sanchez-Conde, M. ; Sandoval, A. ; Sandaker, H. ; Sant'Ambrogio, E. ; Santangelo, Andrea ; Santos, E. M. ; Sanuy, A. ; Sapozhnikov, L. ; Sarkar, S. ; Sartore, N. ; Sasaki, H. ; Satalecka, K. ; Sawada, M. ; Scalzotto, V. ; Scapin, V. ; Scarcioffolo, M. ; Schafer, J. ; Schanz, T. ; Schlenstedt, S. ; Schlickeiser, R. ; Schmidt, T. ; Schmoll, J. ; Schovanek, P. ; Schroedter, M. ; Schultz, C. ; Schultze, J. ; Schulz, A. ; Schure, K. ; Schwab, T. ; Schwanke, U. ; Schwarz, J. ; Schwarzburg, S. ; Schweizer, T. ; Schwemmer, S. ; Segreto, A. ; Seiradakis, J. -H. ; Sembroski, G. H. ; Seweryn, K. ; Sharma, M. ; Shayduk, M. ; Shellard, R. C. ; Shi, J. ; Shibata, T. ; Shibuya, A. ; Shum, E. ; Sidoli, L. ; Sidz, M. ; Sieiro, J. ; Sikora, M. ; Silk, J. ; Sillanpaa, A. ; Singh, B. B. ; Sitarek, J. ; Skole, C. ; Smareglia, R. ; Smith, A. ; Smith, D. ; Smith, J. ; Smith, N. ; Sobczynska, D. ; Sol, H. ; Sottile, G. ; Sowinski, M. ; Spanier, F. ; Spiga, D. ; Spyrou, S. ; Stamatescu, V. ; Stamerra, A. ; Starling, R. ; Stawarz, L. ; Steenkamp, R. ; Stegmann, Christian ; Steiner, S. ; Stergioulas, N. ; Sternberger, R. ; Sterzel, M. ; Stinzing, F. ; Stodulski, M. ; Straumann, U. ; Strazzeri, E. ; Stringhetti, L. ; Suarez, A. ; Suchenek, M. ; Sugawara, R. ; Sulanke, K. -H. ; Sun, S. ; Supanitsky, A. D. ; Suric, T. ; Sutcliffe, P. ; Sykes, J. ; Szanecki, M. ; Szepieniec, T. ; Szostek, A. ; Tagliaferri, G. ; Tajima, H. ; Takahashi, H. ; Takahashi, K. ; Takalo, L. ; Takami, H. ; Talbot, C. ; Tammi, J. ; Tanaka, M. ; Tanaka, S. ; Tasan, J. ; Tavani, M. ; Tavernet, J. -P. ; Tejedor, L. A. ; Telezhinsky, Igor O. ; Temnikov, P. ; Tenzer, C. ; Terada, Y. ; Terrier, R. ; Teshima, M. ; Testa, V. ; Tezier, D. ; Thuermann, D. ; Tibaldo, L. ; Tibolla, O. ; Tiengo, A. ; Tluczykont, M. ; Todero Peixoto, C. J. ; Tokanai, F. ; Tokarz, M. ; Toma, K. ; Torii, K. ; Tornikoski, M. ; Torres, D. F. ; Torres, M. ; Tosti, G. ; Totani, T. ; Toussenel, C. ; Tovmassian, G. ; Travnicek, P. ; Trifoglio, M. ; Troyano, I. ; Tsinganos, K. ; Ueno, H. ; Umehara, K. ; Upadhya, S. S. ; Usher, T. ; Uslenghi, M. ; Valdes-Galicia, J. F. ; Vallania, P. ; Vallejo, G. ; van Driel, W. ; van Eldik, C. ; Vandenbrouke, J. ; Vanderwalt, J. ; Vankov, H. ; Vasileiadis, G. ; Vassiliev, V. ; Veberic, D. ; Vegas, I. ; Vercellone, S. ; Vergani, S. ; Veyssiere, C. ; Vialle, J. P. ; Viana, A. ; Videla, M. ; Vincent, P. ; Vincent, S. ; Vink, J. ; Vlahakis, N. ; Vlahos, L. ; Vogler, P. ; Vollhardt, A. ; von Gunten, H. P. ; Vorobiov, S. ; Vuerli, C. ; Waegebaert, V. ; Wagner, R. ; Wagner, R. G. ; Wagner, S. ; Wakely, S. P. ; Walter, R. ; Walther, T. ; Warda, K. ; Warwick, R. ; Wawer, P. ; Wawrzaszek, R. ; Webb, N. ; Wegner, P. ; Weinstein, A. ; Weitzel, Q. ; Welsing, R. ; Werner, M. ; Wetteskind, H. ; White, R. ; Wierzcholska, A. ; Wiesand, S. ; Wilkinson, M. ; Williams, D. A. ; Willingale, R. ; Winiarski, K. ; Wischnewski, R. ; Wisniewski, L. ; Wood, M. ; Woernlein, A. ; Xiong, Q. ; Yadav, K. K. ; Yamamoto, H. ; Yamamoto, T. ; Yamazaki, R. ; Yanagita, S. ; Yebras, J. M. ; Yelos, D. ; Yoshida, A. ; Yoshida, T. ; Yoshikoshi, T. ; Zabalza, V. ; Zacharias, M. ; Zajczyk, A. ; Zanin, R. ; Zdziarski, A. ; Zech, Alraune ; Zhao, A. ; Zhou, X. ; Zietara, K. ; Ziolkowski, J. ; Ziolkowski, P. ; Zitelli, V. ; Zurbach, C. ; Zychowski, P.
The Cherenkov Telescope Array (CTA) is a new observatory for very high-energy (VHE) gamma rays. CTA has ambitions science goals, for which it is necessary to achieve full-sky coverage, to improve the sensitivity by about an order of magnitude, to span about four decades of energy, from a few tens of GeV to above 100 TeV with enhanced angular and energy resolutions over existing VHE gamma-ray observatories. An international collaboration has formed with more than 1000 members from 27 countries in Europe, Asia, Africa and North and South America. In 2010 the CTA Consortium completed a Design Study and started a three-year Preparatory Phase which leads to production readiness of CTA in 2014. In this paper we introduce the science goals and the concept of CTA, and provide an overview of the project.