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30 results on '"atmospheric cherenkov telescopes"'

1. Application of Machine and Deep Learning Methods to the Analysis of IACTs Data

Author: Bruno, Alessandro, Pagliaro, Antonio, La Parola, Valentina, Zelinka, Ivan, Series Editor, Adamatzky, Andrew, Series Editor, Chen, Guanrong, Series Editor, Abraham, Ajith, Editorial Board Member, Lucia, Ana, Editorial Board Member, Burguillo, Juan C., Editorial Board Member, Čelikovský, Sergej, Editorial Board Member, Chadli, Mohammed, Editorial Board Member, Corchado, Emilio, Editorial Board Member, Davendra, Donald, Editorial Board Member, Ilachinski, Andrew, Editorial Board Member, Lampinen, Jouni, Editorial Board Member, Middendorf, Martin, Editorial Board Member, Ott, Edward, Editorial Board Member, Pan, Linqiang, Editorial Board Member, Păun, Gheorghe, Editorial Board Member, Richter, Hendrik, Editorial Board Member, Rodriguez-Aguilar, Juan A., Editorial Board Member, Rössler, Otto, Editorial Board Member, Snasel, Vaclav, Editorial Board Member, Vondrák, Ivo, Editorial Board Member, Zenil, Hector, Editorial Board Member, Brescia, Massimo, editor, and Baron, Dalya, editor
Published: 2021
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2. The Making of Catalogues of Very-High-Energy γ-ray Sources.

Author: de Naurois, Mathieu
Subjects: *GAMMA rays, *CHERENKOV counters, *TELESCOPES, *STEREOSCOPIC views, *COSMIC rays
Abstract: Thirty years after the discovery of the first very-high-energy g-ray source by the Whipple telescope, the field experienced a revolution mainly driven by the third generation of imaging atmospheric Cherenkov telescopes (IACTs). The combined use of large mirrors and the invention of the imaging technique at the Whipple telescope, stereoscopic observations, developed by the HEGRA array and the fine-grained camera, pioneered by the CAT telescope, led to a jump by a factor of more than ten in sensitivity. The advent of advanced analysis techniques led to a vast improvement in background rejection, as well as in angular and energy resolutions. Recent instruments already have to deal with a very large amount of data (petabytes), containing a large number of sources often very extended (at least within the Galactic plane) and overlapping each other, and the situation will become even more dramatic with future instruments. The first large catalogues of sources have emerged during the last decade, which required numerous, dedicated observations and developments, but also made the first population studies possible. This paper is an attempt to summarize the evolution of the field towards the building up of the source catalogues, to describe the first population studies already made possible, and to give some perspectives in the context of the upcoming, new generation of instruments. [ABSTRACT FROM AUTHOR]
Published: 2021
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3. Performance of the MAGIC stereo system obtained with Crab Nebula data

Author: Antoranz Canales, Pedro, Barrio Uña, Juan Abel, Contreras González, José Luis, Fonseca González, Mª Victoria, López Moya, Marcos, Miranda Pantoja, José Miguel, Nieto, Daniel, Satalecka, Konstanzja, Scapin, Valeria, Antoranz Canales, Pedro, Barrio Uña, Juan Abel, Contreras González, José Luis, Fonseca González, Mª Victoria, López Moya, Marcos, Miranda Pantoja, José Miguel, Nieto, Daniel, Satalecka, Konstanzja, and Scapin, Valeria
Abstract: © 2011 Elsevier B.V. We would like to thank the Instituto de Astrofísica de Canarias for the excellent working conditions at the Observatorio del Roque de los Muchachos in La Palma. The support of the German BMBF and MPG, the Italian INFN, the Swiss National Fund SNF, and the Spanish MICINN is gratefully acknowledged.This work was also supported by the Marie Curie program, by the CPAN CSD2007-00042 and MultiDark CSD2009-00064 projects of the Spanish Consolider-Ingenio 2010 programme, by grant DO02-353 of the Bulgarian NSF, by grant 127740 of the Academy of Finland, by the YIP of the Helmholtz Gemeinschaft, by the DFG Cluster of Excellence “Origin and Structure of the Universe”, by the DFG Collaborative Research Centers SFB823/C4 and SFB876/C3, and by the Polish MNiSzW grant 745/N-HESS-MAGIC/2010/0., MAGIC is a system of two Imaging Atmospheric Cherenkov Telescopes located in the Canary island of La Palma. Since autumn 2009 both telescopes have been working together in stereoscopic mode, providing a significant improvement with respect to the previous single-telescope observations. We use observations of the Crab Nebula taken at low zenith angles to assess the performance of the MAGIC stereo system. The trigger threshold of the MAGIC telescopes is 50 - 60 GeV. Advanced stereo analysis techniques allow MAGIC to achieve a sensitivity as good as (0.76 +/- 0.03)% of the Crab Nebula flux in 50 h of observations above 290 GeV. The angular resolution at those energies is better than similar to 0.07 degrees. We also perform a detailed study of possible systematic effects which may influence the analysis of the data taken with the MAGIC telescopes. (C) 2011 Elsevier B.V. All rights reserved., German BMBF, MPG, Italian INFN, Swiss National Fund SNF, Spanish MICINN, Marie Curie program, Spanish Consolider-Ingenio programme, Bulgarian NSF, Academy of Finland, YIP of the Helmholtz Gemeinschaft, DFG Collaborative Research Centers, Polish MNiSzW, Depto. de Estructura de la Materia, Física Térmica y Electrónica, Fac. de Ciencias Físicas, TRUE, pub
Published: 2023

4. High-Energy Gamma-Ray Astronomy. Results on Fundamental Questions after 30 Years of Ground-Based Observations.

Author: de Almeida, Ulisses Barres, Doro, Michele, and de Almeida, Ulisses Barres
Subjects: Mathematics & science, Research & information: general, Cherenkov telescopes, Crab Nebula, Galactic cosmic rays, Gamma-ray bursts, IACT, IACT technology, IACTs, INTEGRAL legacy data base, ISM: individual objects-Crab Nebula, ISM: supernova remnants, Lorentz invariance violation, MHD, Milky Way, PeVatron, Quantum Gravity, TeV gamma-rays, acceleration of particles, alerts, angular resolution, astroparticle physics, astrophysical plasmas, atmospheric Cherenkov telescopes, axion-like particles, background radiation, bayes, cosmic rays, data format, electromagnetic cascades, energy spectral distribution, galaxies, gamma ray astronomy, gamma rays, gamma rays: general, gamma-ray astronomy, gamma-rays, ground-based gamma-ray astrophysics, high energy astrophysics, high-energy, high-energy gamma rays, high-energy gamma-ray astrophysics, imaging atmospheric Cherenkov technique, imaging atmospheric Cherenkov telescope, imaging atmospheric Cherenkov telescopes, intergalactic magnetic fields, interstellar medium, keV-TeV cosmic sources, likelihood, modified photon interactions, multi-messenger, n/a, non-thermal emission, non-thermal radiation, open science, pair production, pevatrons, photon-photon interaction, pulsars: general, radiation mechanisms: non-thermal, radiation mechanisms: nonthermal, radiative processes, real-time, relativistic astrophysics, source catalogues, statistical analysis, time of flight, very high energy gamma-ray telescope, very-high energy Gamma-rays, very-high-energy gamma-ray astronomy, very-high-energy gamma-ray astrophysics, very-high-energy γ-ray astronomy, γ-ray astronomy
Abstract: Summary: This volume celebrates the 30th anniversary of the first very-high energy (VHE) gamma-ray Source detection: the Crab Nebula, observed by the pioneering ground-based Cherenkov telescope Whipple, at teraelectronvolts (TeV) energies, in 1989. As we entered a new era in TeV astronomy, with the imminent start of operations of the Cherenkov Telescope Array (CTA) and new facilities such as LHAASO and the proposed Southern Wide-Field Gamma-ray Observatory (SWGO), we conceived of this volume as a broad reflection on how far we have evolved in the astrophysics topics that dominated the field of TeV astronomy for much of recent history.In the past two decades, H.E.S.S., MAGIC and VERITAS pushed the field of TeV astronomy, consolidating the field of TeV astrophysics, from few to hundreds of TeV emitters. Today, this is a mature field, covering almost every topic of modern astrophysics. TeV astrophysics is also at the center of the multi-messenger astrophysics revolution, as the extreme photon energies involved provide an effective probe in cosmic-ray acceleration, propagation and interaction, in dark matter and exotic physics searches. The improvement that CTA will carry forward and the fact that CTA will operate as the first open observatory in the field, mean that gamma-ray astronomy is about to enter a new precision and productive era.This book aims to serve as an introduction to the field and its state of the art, presenting a series of authoritative reviews on a broad range of topics in which TeV astronomy provided essential contributions, and where some of the most relevant questions for future research lie.

5. Mirror production for the Cherenkov telescopes of the ASTRI mini-array and the MST project for the Cherenkov Telescope Array

Author: Nicola La Palombara, Giorgia Sironi, Enrico Giro, Salvatore Scuderi, Rodolfo Canestrari, Simone Iovenitti, Markus Garczarczyk, Maria Krause, Sebastian Diebold, Rachele Millul, Fabio Marioni, Nadia Missaglia, Matteo Redaelli, Giuseppe Valsecchi, Fabio Zocchi, Adelfio Zanoni, Giovanni Pareschi, ITA, and DEU
Subjects: Cherenkov Telescope Array, cold-slumping technology, Spherical lenses, FOS: Physical sciences, quality: monitoring, fabrication, hot-slumpìing technology, quality assurance, Reflectivity, monitoring [quality], Atmospheric Cherenkov telescopes, ddc:530, Solids, ASTRI, mirror, Instrumentation and Methods for Astrophysics (astro-ph.IM), Instrumentation, activity report, CTA, Mechanical Engineering, Glasses, coating, Astronomy and Astrophysics, Point spread functions, Electronic, Optical and Magnetic Materials, Mirrors, Cherenkov counter, Space and Planetary Science, Control and Systems Engineering, dual mirror, Astrophysics - Instrumentation and Methods for Astrophysics, performance, Telescopes, Aluminum
Abstract: SPIE Optical Engineering + Applications, San Diego, United States, 11 Aug 2019 - 15 Aug 2019; Journal of astronomical telescopes, instruments, and systems 8, 014005 (2022). doi:10.1117/1.JATIS.8.1.014005, The Cherenkov Telescope Array (CTA) is the next ground-based γ-ray observatory in the TeV γ-ray spectral region operating with the Imaging Atmospheric Cherenkov Technique. It is based on almost 70 telescopes of different class diameters - LST, MST and SST of 23, 12, and 4 m, respectively - to be installed in two sites in the two hemispheres (at La Palma, Canary Islands, and near Paranal, Chile). Several thousands of reflecting mirror tiles larger than 1 m$^2$ will be produced for realizing the segmented primary mirrors of a so large number of telescopes. Almost in parallel, the ASTRI Mini-Array (MA) is being implemented in Tenerife (Canary Islands), composed of nine 4 m diameter dual-mirror Cherenkov telescopes (very similar to the SSTs). We completed the mirror production for all nine telescopes of the ASTRI MA and two MST telescopes (400 segments in total) using the cold glass slumping replication technology. The results related to the quality achieved with a so large-scale production are presented, also discussing the adopted testing methods and approaches. They will be very useful for the adoption and optimization of the quality assurance process for the huge production (almost 3000 m$^2$ of reflecting surface) of the MST and SST CTA telescopes., Published by SPIE, [Bellingham, Wash.]
Published: 2022
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6. Architecture and performance of the KM3NeT front-end firmware

Author: Centre Tecnològic de Vilanova i la Geltrú, Universitat Politècnica de Catalunya. LAB - Laboratori d'Aplicacions Bioacústiques, Aiello, S, Albert, Arnauld, Alves Garre, Sergio, Zineb, Aly, Ameli, Fabrizio, André, Michel, Androulakis, Giorgos, Anghinolfi, Marco, Anguita, M., Anton, Gisela, Centre Tecnològic de Vilanova i la Geltrú, Universitat Politècnica de Catalunya. LAB - Laboratori d'Aplicacions Bioacústiques, Aiello, S, Albert, Arnauld, Alves Garre, Sergio, Zineb, Aly, Ameli, Fabrizio, André, Michel, Androulakis, Giorgos, Anghinolfi, Marco, Anguita, M., and Anton, Gisela
Abstract: The KM3NeT infrastructure consists of two deep-sea neutrino telescopes being deployed in the Mediterranean Sea. The telescopes will detect extraterrestrial and atmospheric neutrinos by means of the incident photons induced by the passage of relativistic charged particles through the seawater as a consequence of a neutrino interaction. The telescopes are configured in a three-dimensional grid of digital optical modules, each hosting 31 photomultipliers. The photomultiplier signals produced by the incident Cherenkov photons are converted into digital information consisting of the integrated pulse duration and the time at which it surpasses a chosen threshold. The digitization is done by means of time to digital converters (TDCs) embedded in the field programmable gate array of the central logic board. Subsequently, a state machine formats the acquired data for its transmission to shore. We present the architecture and performance of the front-end firmware consisting of the TDCs and the state machine, Article signat per 248 autors/es: Sebastiano Aiello, Arnauld Albert, Sergio Alves Garre, Zineb Aly, Fabrizio Ameli, Michel Andre, Giorgos Androulakis, Marco Anghinolfi, Mancia Anguita, Gisela Anton, Miquel Ardid, Julien Aublin, Christos Bagatelas, Giancarlo Barbarino, Bruny Baret, Suzan Basegmez du Pree, Anastasios Belias, Meriem Bendahman, Edward Berbee, Ad M. van den Berg, Vincent Bertin, Vincent van Beveren, Simone Biagi, Andrea Biagioni, Matthias Bissinger, Markus Boettcher, Jihad Boumaaza, Mohammed Bouta, Mieke Bouwhuis, Cristiano Bozza, Horea Brânzas, Ronald Bruijn, Jurgen Brunner, Ernst-Jan Buis, Raffaele Buompane, Jose Busto, Barbara Caiffi, David Calvo, Antonio Capone, Victor Carretero, Paolo Castaldi, Silvia Celli, Mohamed Chabab, Nhan Chau, Andrew Chen, Silvio Cherubini, Vitaliano Chiarella, Tommaso Chiarusi, Marco Circella, Rosanna Cocimano, Joao A. B. Coelho, Alexis Coleiro, Marta Colomer Molla, Stephane Colonges, Rosa Coniglione, Imanol Corredoira, Paschal Coyle, Alexandre Creusot, Giacomo Cuttone, Antonio D'Amico, Antonio D’Onofrio, Richard Dallier, Mauro De Palma, Irene Di Palma, Antonio F. Díaz, Didac Diego-Tortosa, Carla Distefano, Alba Domi, Roberto Donà, Corinne Donzaud, Damien Dornic, Manuel Dörr, Doriane Drouhin, Thomas Eberl, Ahmed Eddyamoui, Thijs van Eeden, Daan van Eijk, Imad El Bojaddaini, Dominik Elsaesser, Alexander Enzenhoefer, Victor Espinosa Rosell, Paolo Fermani, Giovanna Ferrara, Miroslav D. Filipovic, Francesco Filippini, Luigi Antonio Fusco, Omar Gabella, Tamas Gal, Alfonso Andres Garcia Soto, Fabio Garufi, Yoann Gatelet, Nicole Geißelbrecht, Lucio Gialanella, Emidio Giorgio, Sara R. Gozzini, Rodrigo Gracia, Kay Graf, Dario Grasso, Giuseppe Grella, Daniel Guderian, Carlo Guidi, Steffen Hallmann, Hassane Hamdaoui, Hans van Haren, Aart Heijboer, Amar Hekalo, Juan J. Hernández-Rey, Jannik Hofestädt, Feifei Huang, Walid Idrissi Ibnsalih, Alin Ilioni, Giulia Illuminati, Clancy W. James, Peter Jansweijer, Maarten de Jong, Paul de Jong, Postprint (published version)
Published: 2021

7. Recent Results from VERITAS.

Author: Quinn, John
Subjects: *CHERENKOV counters, *GALACTIC nuclei, *PULSARS, *SUPERNOVA remnants, *DARK matter
Published: 2011

8. The potential for intensity interferometry with γ-ray telescope arrays.

Author: de Wit, W. J., Le Bohec, S., Hinton, J. A., White, R. J., Daniel, M. K., and Holder, J.
Subjects: *INTERFEROMETRY, *SPACE interferometry, *TELESCOPES, *OPTICAL measurements, *OPTICAL instruments
Abstract: Intensity interferometry exploits a quantum optical effect in order to measure objects with extremely small angular scales. The first experiment to use this technique was the Narrabri intensity interferometer, which was successfully used in the 1970s to measure 32 stellar diameters at optical wavelengths; some as small as 0.4 milli-arcseconds. The advantage of this technique, in comparison with Michelson interferometers, is that it requires only relatively crude, but large, light collectors equipped with fast (nanosecond) photon detectors. Ground-based γ-ray telescope arrays have similar specifications, and a number of these observatories are now operating worldwide, with more extensive installations planned for the future. These future instruments (CTA, AGIS, completion 2015) with 30–90 telescopes will provide 400–4000 different baselines that range in length between 50 m and a kilometre. Intensity interferometry with such arrays of telescopes attains 50 μ-arcsecond resolution for a limiting mv∼8.5. Phase information can be extracted from the interferometric measurement with phase closure, allowing image reconstruction. This technique opens the possibility of a wide range of studies amongst others, probing the stellar surface activity and the dynamic AU scale circumstellar environment of stars in various crucial evolutionary stages. Here we focuse on the astrophysical potential of an intensity interferometer utilising planned new γ-ray instrumentation. [ABSTRACT FROM AUTHOR]
Published: 2008
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9. Recent Results from CANGAROO.

Author: MASAKI MORI
Subjects: GAMMA ray bursts, CHERENKOV radiation, CRAB Nebula, ZENITH distance, MONTE Carlo method
Published: 2007

10. Architecture and performance of the KM3NeT front-end firmware

Author: Suzan Basegmez du Pree, Daan van Eijk, Silvia Celli, Francisco Salesa Greus, Fabrizio Raffaelli, Joao Coelho, E. Tenllado, M. Taiuti, Carlos Maximiliano Mollo, S. Mazzou, Gisela Anton, Diego Real, S. Biagi, Antonio D'Onofrio, Giulia Illuminati, Alessandro Lonardo, E. Tzamariudaki, Alfonso Andres Garcia Soto, Uli Katz, Thijs van Eeden, David Muñoz Pérez, M. Morganti, Jörn Wilms, Thierry Pradier, S. Rivoire, P. Coyle, Imad El Bojaddaini, Zineb Aly, Giacomo Cuttone, M. Perrin-Terrin, Carlo Alessandro Nicolau, H. Brânzaş, Thomas Eberl, Dídac Diego-Tortosa, M. Bouta, K. Pikounis, Paolo Fermani, Gwenhaël de Wasseige, Mario Musumeci, D. Stavropoulos, Vincent van Beveren, S. Colonges, Veronique Van Elewyck, Abdelilah Moussa, Paolo Musico, Tommaso Chiarusi, Miles Lindsey Clark, P.M. Kooijman, R. Muller, S. M. Stellacci, Emanuele Leonora, S. R. Gozzini, M. Ardid, Jose Busto, Bouke Jisse Jung, Michael Kreter, M. Anghinolfi, A. Martini, N. Geißelbrecht, Annarita Margiotta, A. D'Amico, Dario Grasso, T. Thakore, Sara Pulvirenti, Jean Lesrel, Stefano Mastroianni, A. W. Chen, Doriane Drouhin, H. Hamdaoui, Mohamed Chabab, Jutta Schnabel, Giovanna Ferrara, J.J. Hernández-Rey, Jürgen Brunner, Rémy Le Breton, Raffaele Buompane, Damien Dornic, Angelo Orlando, Jos Steijger, Rosanna Cocimano, Irene Sgura, Antonio F. Díaz, Andrea Biagioni, S. Reck, Corinne Donzaud, Barbara Caiffi, Piotr Mijakowski, G. Pellegrini, Michel André, Alin Ilioni, Francesco Simeone, Fabio Marzaioli, Giancarlo Barbarino, M. Richer, Paolo Piattelli, A. Sinopoulou, M. Bendahman, C. Bagatelas, Sandra Zavatarelli, Juan Paris P. Gonzalez, R. Wojaczyński, R. Bruijn, Arnauld Albert, Riccardo Papaleo, Julien Aublin, M. Dörr, G. Androulakis, R. Coniglione, T. Gal, R. Gracia, C. Distefano, Antoine Kouchner, Ofelia Pisanti, Richard Dallier, Daniele Vivolo, D. F. E. Samtleben, A. Hekalo, Mancia Anguita, Matthias Bissinger, A. Zegarelli, Robert Lahmann, J. Hofestädt, Paolo Castaldi, Lilian Martin, Bernardino Spisso, C. Guidi, Pasquale Migliozzi, Jihad Boumaaza, Mitchell O'Sullivan, L. Maderer, R. Donà, Y. Gatelet, Natalia Zywucka, O. Rabyang, Agustin Sanchez Losa, Els Koffeman, Federico Versari, A. Belias, Bruny Baret, Markus Boettcher, Rezo Shanidze, Silvio Cherubini, J. Schumann, Francesco Leone, D. Guderian, D. Tzanetatos, Giorgi Kistauri, Cristiano Bozza, Kay Graf, Karel Melis, Walid Idrissi Ibnsalih, Soebur Razzaque, Piera Sapienza, V. Chiarella, J. Schmelling, G. Pühlhofer, Fabio Longhitano, V. Carretero, Nhan Chau, Piotr Kalaczyński, Giuseppina Larosa, Mauro De Palma, G. Papalashvili, Karl Mannheim, D. Zaborov, Marco Circella, Ahmed Eddyamoui, L. Nauta, Victor Espinosa Rosell, Matteo Sanguineti, Christos Markou, Carmelo Pellegrino, F. Garufi, C. Pieterse, V. Bertin, C. W. James, Alice Paun, M. D. Filipovic, G.E. Păvălaş, C. Poirè, G. Vasileiadis, Daniele Zito, S. Viola, Ankur Sharma, Ornella Leonardi, Maarten De Jong, Marta Colomer Molla, E. Berbee, Sergio Alves Garre, Emilio Migneco, Imanol Corredoira, Ad van den Berg, Nafis Rezwan Khan Chowdhury, Oleg Kalekin, M. Organokov, B. Ó Fearraigh, A. Creusot, Antonio Marinelli, Gennaro Miele, Giorgio Riccobene, Lucio Gialanella, J.D. Zornoza, Nunzio Randazzo, Giuseppe Levi, F. Filippini, Frits van der Knaap, Steven Tingay, Domenico Santonocito, J. Seneca, Michael Moser, Alba Domi, D. Calvo, Massimiliano Lincetto, D. Lopez-Coto, V. Popa, Steffen Hallmann, Hans van Haren, Irene Di Palma, Andrea Santangelo, Yahya Tayalati, Matthias Kadler, Paul de Jong, Peter Jansweijer, C. Pastore, Luis Salvador Miranda Palacios, J. Zúñiga, J.A. Martínez-Mora, Alexis Coleiro, Fabrizio Ameli, Alberto Rovelli, Emidio Giorgio, Vladimir Kulikovskiy, Luigi Antonio Fusco, Antonio Capone, J. Manczak, D. Elsaesser, Maurizio Spurio, E. Buis, F. Huang, A.J. Heijboer, M.C. Bouwhuis, Giuseppe Grella, Sebastiano Aiello, Thomas Lipreau, Els de Wolf, S. Sánchez Navas, Alexander Enzenhoefer, O. Gabella, KM3NeT (IHEF, IoP, FNWI), Aiello, Sebastiano, Albert, Arnauld, Garre, Sergio Alve, Aly, Zineb, Ameli, Fabrizio, Andre, Michel, Androulakis, Giorgo, Anghinolfi, Marco, Anguita, Mancia, Anton, Gisela, Ardid, Miquel, Aublin, Julien, Bagatelas, Christo, Barbarino, Giancarlo, Baret, Bruny, Basegmez du Pree, Suzan, Belias, Anastasio, Bendahman, Meriem, Berbee, Edward, van den Berg, Ad M., Bertin, Vincent, van Beveren, Vincent, Biagi, Simone, Biagioni, Andrea, Bissinger, Matthia, Boettcher, Marku, Boumaaza, Jihad, Bouta, Mohammed, Bouwhuis, Mieke, Bozza, Cristiano, Brânzaş, Horea, Bruijn, Ronald, Brunner, Jurgen, Buis, Ernst-Jan, Buompane, Raffaele, Busto, Jose, Caiffi, Barbara, Calvo, David, Capone, Antonio, Carretero, Victor, Castaldi, Paolo, Celli, Silvia, Chabab, Mohamed, Chau, Nhan, Chen, Andrew W., Cherubini, Silvio, Chiarella, Vitaliano, Chiarusi, Tommaso, Circella, Marco, Cocimano, Rosanna, Coelho, Joao A. B., Coleiro, Alexi, Molla, Marta C., Colonges, Stephane, Coniglione, Rosa, Corredoira, Imanol, Coyle, Paschal, Creusot, Alexandre, Cuttone, Giacomo, Amico, Antonio D’, D’Onofrio, Antonio, Dallier, Richard, De Palma, Mauro, Di Palma, Irene, Díaz, Antonio F., Diego-Tortosa, Didac, Distefano, Carla, Domi, Alba, Donà, Roberto, Donzaud, Corinne, Dornic, Damien, Dörr, Manuel, Drouhin, Doriane, Eberl, Thoma, Eddyamoui, Ahmed, van Eeden, Thij, van Eijk, Daan, El Bojaddaini, Imad, Elsaesser, Dominik, Enzenhoefer, Alexander, Rosell, Victor Espinosa, Fermani, Paolo, Ferrara, Giovanna, Filipović, Miroslav D., Filippini, Francesco, Fusco, Luigi A., Gabella, Omar, Gal, Tama, Soto, Alfonso Andres Garcia, Garufi, Fabio, Gatelet, Yoann, Geißelbrecht, Nicole, Gialanella, Lucio, Giorgio, Emidio, Gozzini, Sara R., Gracia, Rodrigo, Graf, Kay, Grasso, Dario, Grella, Giuseppe, Guderian, Daniel, Guidi, Carlo, Hallmann, Steffen, Hamdaoui, Hassane, van Haren, Han, Heijboer, Aart, Hekalo, Amar, Hernández-Rey, Juan J., Hofestädt, Jannik, Huang, Feifei, Ibnsalih, Walid Idrissi, Ilioni, Alin, Illuminati, Giulia, James, Clancy W., Jansweijer, Peter, de Jong, Maartin, de Jong, Paul, Jung, Bouke Jisse, Kadler, Matthia, Kalaczyński, Piotr, Kalekin, Oleg, Katz, Uli F., Khan Chowdhury, Nafis R., Kistauri, Giorgi, van der Knaap, Frit, Koffeman, Els N., Kooijman, Paul, Kouchner, Antoine, Kreter, Michael, Kulikovskiy, Vladimir, Lahmann, Robert, Larosa, Giuseppina, Le Breton, Remy, Leonardi, Ornella, Leone, Francesco, Leonora, Emanuele, Lesrel, Jean, Levi, Giuseppe, Lincetto, Massimiliano, Lindsey Clark, Mile, Lipreau, Thoma, Lonardo, Alessandro, Longhitano, Fabio, Lopez-Coto, Daniel, Maderer, Luka, Mańczak, Jerzy M., Mannheim, Karl, Margiotta, Annarita, Marinelli, Antonio, Markou, Christo, Martin, Lilian, Martínez-Mora, Juan A., Martini, Agnese, Marzaioli, Fabio, Mastroianni, Stefano, Mazzou, Safaa, Melis, Karel W., Miele, Gennaro, Migliozzi, Pasquale, Migneco, Emilio, Mijakowski, Piotr, Miranda Palacios, Luis S., Mollo, Carlos M., Morganti, Mauro, Moser, Michael, Moussa, Abdelilah, Muller, Rasa, Pérez, David Muñoz, Musico, Paolo, Musumeci, Mario, Nauta, Lodewijk, Navas, Sergio, Nicolau, Carlo A., Fearraigh, Brian Ó., O’Sullivan, Mitchell, Organokov, Mukharbek, Orlando, Angelo, González, Juan Palacio, Papalashvili, Gogita, Papaleo, Riccardo, Pastore, Cosimo, Păun, Alice M., Păvălaş, Gabriela E., Pellegrini, Giuliano, Pellegrino, Carmelo, Perrin-Terrin, Mathieu, Piattelli, Paolo, Pieterse, Camiel, Pikounis, Konstantino, Pisanti, Ofelia, Poirè, Chiara, Popa, Vlad, Pradier, Thierry, Pühlhofer, Gerd, Pulvirenti, Sara, Rabyang, Omphile, Raffaelli, Fabrizio, Randazzo, Nunzio, Razzaque, Soebur, Real, Diego, Reck, Stefan, Riccobene, Giorgio, Richer, Marc, Rivoire, Stephane, Rovelli, Alberto, Salesa Greus, Francisco, Samtleben, Dorothea F. E., Sánchez Losa, Agustin, Sanguineti, Matteo, Santangelo, Andrea E., Santonocito, Domenico, Sapienza, Piera, Schmelling, Jan-Willem, Schnabel, Jutta, Schumann, Johanne, Seneca, Jordan, Sgura, Irene, Shanidze, Rezo, Sharma, Ankur, Simeone, Francesco, Sinopoulou, Anna, Spisso, Bernardino, Spurio, Maurizio, Stavropoulos, Dimitri, Steijger, Jo, Stellacci, Simona Maria, Taiuti, Mauro, Tayalati, Yahya, Tenllado, Enrique, Thakore, Tarak, Tingay, Steven, Tzamariudaki, Ekaterini, Tzanetatos, Dimitrio, Van Elewyck, Veronique, Vasileiadis, George, Versari, Federico, Viola, Salvo, Vivolo, Daniele, de Wasseige, Gwenhael, Wilms, Joern, Wojaczyński, Rafa, de Wolf, El, Zaborov, Dmitry, Zavatarelli, Sandra, Zegarelli, Angela, Zito, Daniele, de Dios Zornoza, Juan, Zúñiga, Juan, Zywucka, Natalia, Aiello, S., Albert, A., Garre, S. A., Aly, Z., Ameli, F., Andre, M., Androulakis, G., Anghinolfi, M., Anguita, M., Anton, G., Ardid, M., Aublin, J., Bagatelas, C., Barbarino, G., Baret, B., Du Pree, S. B., Belias, A., Bendahman, M., Berbee, E., Van Den Berg, A. M., Bertin, V., Van Beveren, V., Biagi, S., Biagioni, A., Bissinger, M., Boettcher, M., Boumaaza, J., Bouta, M., Bouwhuis, M., Bozza, C., Branzas, H., Bruijn, R., Brunner, J., Buis, E. -J., Buompane, R., Busto, J., Caiffi, B., Calvo, D., Capone, A., Carretero, V., Castaldi, P., Celli, S., Chabab, M., Chau, N., Chen, A., Cherubini, S., Chiarella, V., Chiarusi, T., Circella, M., Cocimano, R., Coelho, J. A. B., Coleiro, A., Molla, M. C., Colonges, S., Coniglione, R., Corredoira, I., Coyle, P., Creusot, A., Cuttone, G., Amico, A. D., D'Onofrio, A., Dallier, R., De Palma, M., Di Palma, I., Diaz, A. F., Diego-Tortosa, D., Distefano, C., Domi, A., Dona, R., Donzaud, C., Dornic, D., Doerr, M., Drouhin, D., Eberl, T., Eddyamoui, A., Van Eeden, T., Van Eijk, D., El Bojaddaini, I., Elsaesser, D., Enzenhoefer, A., Rosell, V. E., Fermani, P., Ferrara, G., Filipovic, M. D., Filippini, F., Fusco, L. A., Gabella, O., Gal, T., Soto, A. A. G., Garufi, F., Gatelet, Y., Geisselbrecht, N., Gialanella, L., Giorgio, E., Gozzini, S. R., Gracia, R., Graf, K., Grasso, D., Grella, G., Guderian, D., Guidi, C., Hallmann, S., Hamdaoui, H., Van Haren, H., Heijboer, A., Hekalo, A., Hernandez-Rey, J. J., Hofestadt, J., Huang, F., Ibnsalih, W. I., Ilioni, A., Illuminati, G., James, C. W., Jansweijer, P., De Jong, M., De Jong, P., Jung, B. J., Kadler, M., Kalaczynski, P., Kalekin, O., Katz, U. F., Chowdhury, N. R. K., Kistauri, G., Van Der Knaap, F., Koffeman, E. N., Kooijman, P., Kouchner, A., Kreter, M., Kulikovskiy, V., Lahmann, R., Larosa, G., Le Breton, R., Leonardi, O., Leone, F., Leonora, E., Lesrel, J., Levi, G., Lincetto, M., Clark, M. L., Lipreau, T., Lonardo, A., Longhitano, F., Lopez-Coto, D., Maderer, L., Manczak, J. M., Mannheim, K., Margiotta, A., Marinelli, A., Markou, C., Martin, L., Martinez-Mora, J. A., Martini, A., Marzaioli, F., Mastroianni, S., Mazzou, S., Melis, K. W., Miele, G., Migliozzi, P., Migneco, E., Mijakowski, P., Palacios, L. S. M., Maximiliano Mollo, C., Morganti, M., Moser, M., Moussa, A., Muller, R., Perez, D. M., Musico, P., Musumeci, M., Nauta, L., Navas, S., Nicolau, C. A., Fearraigh, B. O., O'Sullivan, M., Organokov, M., Orlando, A., Gonzalez, J. P., Papalashvili, G., Papaleo, R., Pastore, C., Paun, A. M., Pavalas, G. E., Pellegrini, G., Pellegrino, C., Perrin-Terrin, M., Piattelli, P., Pieterse, C., Pikounis, K., Pisanti, O., Poire, C., Popa, V., Pradier, T., Puhlhofer, G., Pulvirenti, S., Rabyang, O., Raffaelli, F., Randazzo, N., Razzaque, S., Real, D., Reck, S., Riccobene, G., Richer, M., Rivoire, S., Rovelli, A., Salesa Greus, F., Samtleben, D. F. E., Losa, A. S., Sanguineti, M., Santangelo, A. E., Santonocito, D., Sapienza, P., Schmelling, J. -W., Schnabel, J., Schumann, J., Seneca, J., Sgura, I., Shanidze, R., Sharma, A., Simeone, F., Sinopoulou, A., Spisso, B., Spurio, M., Stavropoulos, D., Steijger, J., Stellacci, S. M., Taiuti, M., Tayalati, Y., Tenllado, E., Thakore, T., Tingay, S., Tzamariudaki, E., Tzanetatos, D., Van Elewyck, V., Vasileiadis, G., Versari, F., Viola, S., Vivolo, D., De Wasseige, G., Wilms, J., Wojaczynski, R., De Wolf, E., Zaborov, D., Zavatarelli, S., Zegarelli, A., Zito, D., De Dios Zornoza, J., Zuniga, J., Zywucka, N., Groupe de Recherche en Physique des Hautes Energies (GRPHE), Institut Universitaire de Technologie de Colmar-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA)), Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Laboratoire de physique subatomique et des technologies associées (SUBATECH), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Laboratoire Univers et Particules de Montpellier (LUPM), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), KM3NeT, Research unit Astroparticle Physics, Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-IUT de Colmar, Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA)), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), ANR-15-CE31-0020,DAEMONS,Démonstration de la possibilité d'établir l'ordonnancement des masses de neutrinos dans la mer(2015), ANR-10-LABX-0023,UnivEarthS,Earth - Planets - Universe: observation, modeling, transfer(2010), ANR-18-IDEX-0001,Université de Paris,Université de Paris(2018), Centre Tecnològic de Vilanova i la Geltrú, and Universitat Politècnica de Catalunya. LAB - Laboratori d'Aplicacions Bioacústiques
Subjects: Astrofísica, acquisition firmware, KM3NeT, neutrino telescope, time to digital converters, Computer science, data acquisition, Physics::Instrumentation and Detectors, time-to-digital converter, computer.software_genre, Astrophysics, Neutrino telescope, 01 natural sciences, Front and back ends, Time-to-digital converter, Atmospheric Cherenkov telescopes, time to digital converter, 010303 astronomy & astrophysics, Instrumentation, FPGA, Clocks, photomultiplier, Firmware, 4. Education, Physics, Electrical engineering, Astrophysics::Instrumentation and Methods for Astrophysics, Electronic, Optical and Magnetic Materials, Acquisition firmware, Neutrino, performance, Photomultiplier, Logic, Astrophysics::High Energy Astrophysical Phenomena, Physique [physics]/Physique [physics], Partícules (Física nuclear), 010309 optics, 0103 physical sciences, Quantization, 14. Life underwater, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Field-programmable gate array, Cherenkov radiation, Particles (Nuclear physics), Detectors òptics, Time to digital converters, Optical detectors, Control systems, Photons, Física [Àrees temàtiques de la UPC], Telescopis, business.industry, Mechanical Engineering, Data acquisition, Field programmable gate arrays, Astronomy and Astrophysics, Physique [physics]/Physique des Hautes Energies - Expérience [hep-ex], Space and Planetary Science, Control and Systems Engineering, FISICA APLICADA, electronics: readout, business, computer, Telescopes, electronics: design
Abstract: The authors acknowledge the financial support of the funding agencies: Agence Nationale de la Recherche (contract ANR-15-CE31-0020), Centre National de la Recherche Scientifique (CNRS), Commission Europeenne (FEDER fund and Marie Curie Program), Institut Universitaire de France (IUF), LabEx UnivEarthS (ANR-10-LABX-0023 and ANR-18-IDEX-0001), Paris Ile-de-France Region, France; Shota Rustaveli National Science Foundation of Georgia (SRNSFG, FR-18-1268), Georgia; Deutsche Forschungsgemeinschaft (DFG), Germany; The General Secretariat of Research and Technology (GSRT), Greece; Istituto Nazionale di Fisica Nucleare (INFN), Ministero dell'Istruzione, dell'Universita e della Ricerca (MIUR), PRIN 2017 program (Grant NAT-NET 2017W4HA7S) Italy; Ministry of Higher Education Scientific Research and Professional Training, ICTP through Grant AF-13, Morocco; Nederlandse organisatie voor Wetenschappelijk Onderzoek (NWO), the Netherlands; The National Science Centre, Poland (2015/18/E/ST2/00758); National Authority for Scientific Research (ANCS), Romania; Ministerio de Ciencia, Innovacion, Investigacion y Universidades (MCIU): Programa Estatal de Generacion de Conocimiento (refs. PGC2018-096663-B-C41, -A-C42, -B-C43, -B-C44) (MCIU/FEDER), Severo Ochoa Centre of Excellence and MultiDark Consolider (MCIU), Junta de Andalucia (ref. SOMM17/6104/UGR), Generalitat Valenciana: Grisolia (ref. GRISOLIA/2018/119) and GenT (ref. CIDEGENT/2018/034) programs, La Caixa Foundation (ref. LCF/BQ/IN17/11620019), EU: MSC program (ref. 713673), Spain., The KM3NeT infrastructure consists of two deep-sea neutrino telescopes being deployed in the Mediterranean Sea. The telescopes will detect extraterrestrial and atmospheric neutrinos by means of the incident photons induced by the passage of relativistic charged particles through the seawater as a consequence of a neutrino interaction. The telescopes are configured in a three-dimensional grid of digital optical modules, each hosting 31 photomultipliers. The photomultiplier signals produced by the incident Cherenkov photons are converted into digital information consisting of the integrated pulse duration and the time at which it surpasses a chosen threshold. The digitization is done by means of time to digital converters (TDCs) embedded in the field programmable gate array of the central logic board. Subsequently, a state machine formats the acquired data for its transmission to shore. We present the architecture and performance of the front-end firmware consisting of the TDCs and the state machine., French National Research Agency (ANR) ANR-15-CE31-0020, Centre National de la Recherche Scientifique (CNRS), Commission Europeenne (FEDER fund), France, Commission Europeenne (Marie Curie Program), France, Institut Universitaire de France (IUF), France, LabEx UnivEarthS, France ANR-10-LABX-0023 ANR-18-IDEX-0001, Paris Ile-de-France Region, France, Shota Rustaveli National Science Foundation of Georgia (SRNSFG), Georgia FR-18-1268, German Research Foundation (DFG), Greek Ministry of Development-GSRT, Istituto Nazionale di Fisica Nucleare (INFN) NAT-NET 2017W4HA7S, Ministry of Education, Universities and Research (MIUR) NAT-NET 2017W4HA7S, PRIN 2017 program Italy NAT-NET 2017W4HA7S, Ministry of Higher Education Scientific Research and Professional Training, ICTP, Morocco AF-13, Netherlands Organization for Scientific Research (NWO) Netherlands Government, National Science Centre, Poland 2015/18/E/ST2/00758, National Authority for Scientific Research (ANCS), Romania, Ministerio de Ciencia, Innovacion, Investigacion y Universidades (MCIU): Programa Estatal de Generacion de Conocimiento (MCIU/FEDER), Spain PGC2018-096663-B-C41 PGC2018-096663-A-C42 PGC2018-096663-B-C43 PGC2018-096663-B-C44, Severo Ochoa Centre of Excellence and MultiDark Consolider (MCIU), Spain, Junta de Andalucia European Commission SOMM17/6104/UGR, Generalitat Valenciana: Grisolia program, Spain GRISOLIA/2018/119, Generalitat Valenciana: GenT program, Spain CIDEGENT/2018/034, La Caixa Foundation LCF/BQ/IN17/11620019, EU: MSC program, Spain 713673
Published: 2021
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11. Highlights from VERITAS on VHE gamma-ray sources in our Galaxy.

Author: Ong, Rene A.
Subjects: *GAMMA rays, *COSMIC rays, *CHERENKOV counters, *SPACE telescopes, *GALAXIES, *ASTROPHYSICS
Abstract: Abstract: VERITAS is a major ground-based detector of very high energy (VHE, E GeV) gamma rays and cosmic rays. VERITAS consists of an array of four 12m-diameter atmospheric Cherenkov telescopes that has been fully operational since September 2007. VERITAS has detected many astrophysical sources of VHE gamma rays, including at least 17 VHE sources that are likely Galactic in origin. This paper describes some of the Galactic source highlights from VERITAS with an emphasis on those aspects that relate to the origin of cosmic rays. Specifically, topics include the VERITAS discovery of VHE emission from the Tycho and CTA 1 supernova remnants, the identification of HESS J0632+057 as a new VHE binary, a substantially improved view of the gamma-ray emission in the Cygnus OB1 region, and the recent remarkable discovery of VHE emission from the Crab pulsar. In 2009, VERITAS was upgraded by relocation of one of the telescopes, leading to a significant improvement in sensitivity. A program to further improve the performance of VERITAS, involving the upgrade of the telescope trigger systems and the telescope cameras, was completed in summer 2012. The upgrade has led to an improved sensitivity and a lower energy threshold for VERITAS, allowing it to perform deeper observations of known Galactic and extragalactic sources and to detect fainter and more distant sources. [Copyright &y& Elsevier]
Published: 2014
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12. Composite mirror facets for ground based gamma ray astronomy.

Author: Brun, P., Carton, P.-H., Durand, D., Glicenstein, J.-F., Jeanney, C., Medina, M.C., Micolon, P., and Peyaud, B.
Subjects: *GAMMA ray astronomy, *CHERENKOV radiation, *IONIZING radiation, *ELECTROMAGNETIC waves, *COST effectiveness, *TELESCOPES
Abstract: Abstract: Composite mirrors for gamma-ray astronomy have been developed to fulfill the specifications required for the next generation of Cherenkov telescopes represented by CTA (Cherenkov Telescope Array). In addition to the basic requirements on focus and reflection efficiency, the mirrors have to be stiff, lightweight, durable and cost efficient. In this paper, the technology developed to produce such mirrors is described, as well as some tests that have been performed to validate them. It is shown that these mirrors comply with the needs of CTA, making them good candidates for use on a significant part of the array. [Copyright &y& Elsevier]
Published: 2013
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13. Pointing of HAGAR telescope mirrors.

Author: Gothe, K., Prabhu, T., Vishwanath, P., Acharya, B., Srinivasan, R., Chitnis, V., Kamath, P., Srinivasulu, G., Saleem, F., Kemkar, P., Mahesh, P., Gabriel, F., Manoharan, J., Dorji, N., Dorjai, T., Angchuk, D., D'souza, A., Duhan, S., Nagesh, B., and Rao, S.
Subjects: *TELESCOPES, *GAMMA ray astronomy, *CHERENKOV radiation, *MATHEMATICAL models
Abstract: An array of seven atmospheric Cherenkov telescopes was commissioned at a high altitude site in Hanle in the Ladakh region of the Himalayas. The array called HAGAR has been designed to observe celestial γ-rays of energy >100 GeV. Each telescope is altitude-azimuth mounted and carries seven parabolic mirrors whose optic axes are co-aligned with the telescope axis. The telescopes point and track a celestial source using a PC-based drive control system. Two important issues in positioning of each HAGAR telescope are pointing accuracy of telescope axis and co-alignment of mirrors' optic axes with the telescope axis. We have adopted a three pronged strategy to address these issues, namely use of pointing models to improve pointing accuracy of the telescopes, RA-DEC scan technique to measure the pointing offsets of the mirrors and mechanical fine-tuning of off-axis mirrors by sighting a distant stationary light source. This paper discusses our efforts in this regard as well as the current status of pointing and monitoring of HAGAR telescopes. [ABSTRACT FROM AUTHOR]
Published: 2013
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14. VERITAS:: STATUS SUMMARY 2009.

Author: WEEKES, T. C.
Subjects: *GAMMA rays, *ASTRONOMICAL instruments, *ASTRONOMY, *OBSERVATORIES
Abstract: VERITAS is a ground-based gamma-ray observatory that uses the imaging atmospheric Cherenkov technique and operates in the very-high energy (VHE) region of the gamma-ray spectrum from 100 GeV to 50 TeV. The observatory consists of an array of four 12 m-diameter imaging atmospheric Cherenkov telescopes located in southern Arizona, USA. The four-telescope array has been fully operational since September 2007, and over the last two years, VERITAS has been operating with high reliability and sensitivity. It is currently one of the most sensitive VHE observatories. This paper summarizes the status of VERITAS as of October 2009, and describes the detection of several new VHE gamma-ray sources. [ABSTRACT FROM AUTHOR]
Published: 2010
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15. Image and non-image parameters of atmospheric Cherenkov events: a comparative study of their <f>γ</f>-ray/hadron classification potential in ultrahigh energy regime

Author: Razdan, A., Haungs, A., Rebel, H., and Bhat, C.L.
Subjects: *CHERENKOV counters, *GAMMA rays, *HADRONS
Abstract: In this exploratory simulation study, we compare the event-progenitor classification potential of a variety of measurable parameters of atmospheric Cherenkov pulses which are produced by ultrahigh energy γ-ray and hadron progenitors and are likely to be recorded by the TACTIC (TeV atmospheric Cherenkov telescope with imaging camera) array of atmospheric Cherenkov telescopes. The parameters derived from Cherenkov images include Hillas, fractal and wavelet moments, while those obtained from non-image Cherenkov data consist of pulse profile rise time and base width and the relative ultraviolet to visible light content of the Cherenkov event. It is shown by a neural-net approach that these parameters, when used in suitable combinations, can bring about a proper segregation of the two event types, even with modest sized data samples of progenitor particles. [Copyright &y& Elsevier]
Published: 2002
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16. Upgraded Cameras for the H.E.S.S. Imaging Atmospheric Cherenkov Telescopes

Author: Evans, Christopher J., Simard, Luc, Fontaine, Gérard, Füßling, Matthias, Giebels, Berrie, Glicenstein, Jean-François, Gräber, Tobias, Hinton, James, Jahnke, Albert, Klepser, Stefan, Kossatz, Marko, Kretzschmann, Axel, Takami, Hideki, Lefranc, Valentin, Leich, Holger, Lüdecke, Hartmut, Lypova, Iryna, Manigot, Pascal, Marandon, Vincent, Moulin, Emmanuel, de Naurois, Mathieu, Nayman, Patrick, Penno, Marek, Giavitto, Gianluca, Ross, Duncan, Salek, David, Schade, Markus, Schwab, Thomas, Simoni, Rachel, Stegmann, Christian, Steppa, Constantin, Thornhill, Julian, Toussnel, François, Ashton, Terry, Balzer, Arnim, Berge, David, Brun, Francois, Chaminade, Thomas, Delagnes, Eric, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire Leprince-Ringuet (LLR), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: data acquisition, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, Stereoscopy, 01 natural sciences, programming, Data acquisition, Software, Atmospheric Cherenkov telescopes, HESS, 0103 physical sciences, High Energy Stereoscopic System, Cherenkov counter: imaging, Computing systems, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Data storage, Field-programmable gate array, 010303 astronomy & astrophysics, Cherenkov radiation, detector: design, FPGA, C++, Physics, photomultiplier, 010308 nuclear & particles physics, business.industry, integrated circuit, Field programmable gate arrays, Computer hardware, trigger, Cherenkov Telescope Array, Cameras, Photomultipliers, Upgrade, Gamma radiation, Computer data storage, electronics: readout, upgrade, ddc:620, Electronics, business, performance
Abstract: International audience; The High Energy Stereoscopic System (H.E.S.S.) is an array of five imaging atmospheric Cherenkov telescopes, sensitive to cosmic gamma rays of energies between ~30 GeV and several tens of TeV. Four of them started operations in 2003 and their photomultiplier tube (PMT) cameras are currently undergoing a major upgrade, with the goals of improving the overall performance of the array and reducing the failure rate of the ageing systems. With the exception of the 960 PMTs, all components inside the camera have been replaced: these include the readout and trigger electronics, the power, ventilation and pneumatic systems and the control and data acquisition software. New designs and technical solutions have been introduced: the readout makes use of the NECTAr analog memory chip, which samples and stores the PMT signals and was developed for the Cherenkov Telescope Array (CTA). The control of all hardware subsystems is carried out by an FPGA coupled to an embedded ARM computer, a modular design which has proven to be very fast and reliable. The new camera software is based on modern C++ libraries such as Apache Thrift, ØMQ and Protocol buffers, offering very good performance, robustness, flexibility and ease of development. The first camera was upgraded in 2015, the other three cameras are foreseen to follow in fall 2016. We describe the design, the performance, the results of the tests and the lessons learned from the first upgraded H.E.S.S. camera.© (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Published: 2016
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17. The Cherenkov Telescope Array Observatory: top level use cases

Author: Alessandro Carosi, J.-P. Lenain, Pep Colomé, J. Schmid, E. de Oña Wilhelmi, Elina Lindfors, F. Di Pierro, N. Serre, M. Heller, Catherine Boisson, Sera Markoff, P. Romano, Garret Cotter, Andrea Zoli, Stefano Covino, A. Stamerra, Helene Sol, G. Tosti, S. Vercellone, Markus Gaug, J. Martí Ribas, Zeljka Bosnjak, K. Kosack, A. W. Chen, F. Lucarelli, Carole Mundell, Pierre-Olivier Petrucci, Michael Daniel, J. Goullon, J. Vandenbrouck, Valentina Fioretti, Gernot Maier, Pedro L. Luque-Escamilla, Susumu Inoue, F. Schüssler, J. Schwarz, G. Hermann, J. L. Rodriguez, G. De Cesare, R. A. Ong, Saverio Lombardi, Andrea Bulgarelli, T. Stolarczyk, Vito Conforti, P. T. O'Brien, J. F. Glicenstein, Jose Luis Contreras, Martino Marisaldi, Koji Noda, Ullrich Schwanke, N. Neyroud, L. A. Antonelli, M. Della Volpe, Jürgen Knödlseder, B. Khelifi, Marc Ribó, M. Füßling, Paola Grandi, Ciro Bigongiari, D. Gotz, A. Zech, M. Garczarczyk, Jim Hinton, S. D. Vergani, S. Brau-Nogué, P. Goldoni, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Observatoire de Paris - Site de Paris (OP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), Département de Physique des Particules (ex SPP) (DPP), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Observatoire de Paris - Site de Meudon (OBSPM), Observatoire de Paris, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Département de Physique des Particules (ex SPP) (DPhP), High Energy Astrophys. & Astropart. Phys (API, FNWI), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)
Subjects: Cherenkov Telescope Array, Astronomy, Observatories, Context (language use), feedback, 01 natural sciences, programming, 010309 optics, Software, Observatory, Atmospheric Cherenkov telescopes, 0103 physical sciences, Use case, [INFO]Computer Science [cs], Workgroup, 010303 astronomy & astrophysics, Simulation, Physics, Requirements management, ta115, Equipment and services, business.industry, strong interaction, optics, observatory, Physical sciences, Workflow, Cherenkov counter, gamma ray: VHE, Gamma radiation, flow, Systems engineering, Física nuclear, business, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], acceptance, Telescopes
Abstract: International audience; Today the scientific community is facing an increasing complexity of the scientific projects, from both a technological and a management point of view. The reason for this is in the advance of science itself, where new experiments with unprecedented levels of accuracy, precision and coverage (time and spatial) are realised. Astronomy is one of the fields of the physical sciences where a strong interaction between the scientists, the instrument and software developers is necessary to achieve the goals of any Big Science Project. The Cherenkov Telescope Array (CTA) will be the largest ground-based very high-energy gamma-ray observatory of the next decades. To achieve the full potential of the CTA Observatory, the system must be put into place to enable users to operate the telescopes productively. The software will cover all stages of the CTA system, from the preparation of the observing proposals to the final data reduction, and must also fit into the overall system. Scientists, engineers, operators and others will use the system to operate the Observatory, hence they should be involved in the design process from the beginning. We have organised a workgroup and a workflow for the definition of the CTA Top Level Use Cases in the context of the Requirement Management activities of the CTA Observatory. Scientists, instrument and software developers are collaborating and sharing information to provide a common and general understanding of the Observatory from a functional point of view. Scientists that will use the CTA Observatory will provide mainly Science Driven Use Cases, whereas software engineers will subsequently provide more detailed Use Cases, comments and feedbacks. The main purposes are to define observing modes and strategies, and to provide a framework for the flow down of the Use Cases and requirements to check missing requirements and the already developed Use-Case models at CTA sub-system level. Use Cases will also provide the basis for the definition of the Acceptance Test Plan for the validation of the overall CTA system. In this contribution we present the organisation and the workflow of the Top Level Use Cases workgroup.© (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Published: 2016
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18. Unprecedented study of the broadband emission of Mrk 421 during flaring activity in March 2010

Author: E. Pueschel, J. Hose, Svetlana G. Jorstad, M. F. Aller, David A. Williams, G. H. Sembroski, D. Nakajima, M. Strzys, R. Welsing, A. Archer, E. Colombo, B. Biasuzzi, F. Borracci, Stefano Ansoldi, Riccardo Paoletti, I. Telezhinsky, Jamie Holder, D. Elsaesser, D. Staszak, Dario Hrupec, L. Ciupik, L. C. Reyes, G. Bonnoli, K. Ragan, M. A. Lopez, N. Galante, Hajime Takami, J. M. Paredes, P. T. Reynolds, Natalia Lewandowska, Hugh D. Aller, L. O. Takalo, G. H. Gillanders, T. Schweizer, Mosè Mariotti, Wystan Benbow, A.-K. Overkemping, D. Hadasch, Victor Stamatescu, J. Biteau, Paul S. Smith, Gordon T. Richards, Wei Cui, A. La Barbera, Sinéad M. Griffin, E. Roache, A. López-Oramas, S. Rügamer, Juan Abel Barrio, J. A. Ros, O. M. Kurtanidze, Alessandro Carosi, Ruben Lopez-Coto, X. Paredes-Fortuny, Mark Gurwell, U. Menzel, Saverio Lombardi, Calvin A. Johnson, P. Kar, M. Villata, K. Mallot, R. J. García López, Felix Spanier, M. Kertzman, A. C. S. Readhead, E. Prandini, D. Galindo, Merja Tornikoski, Yusuke Konno, Diego F. Torres, M. G. Nikolashvili, D. Eisenacher, Antonio Stamerra, K. Kodani, Givi N. Kimeridze, Julian Sitarek, Lorand A. Sigua, K. Nishijima, J. V. Tucci, A. Cesarini, M. Perri, P. Kaaret, J. Storz, D. Dominis Prester, Martin Pohl, C. M. Raiteri, Markus Garczarczyk, C. Fruck, A. Sillanpää, N. Håkansson, M. Makariev, T. Toyama, L. Maraschi, A. Pichel, Jose Miguel Miranda, Matteo Cerruti, Konstancja Satalecka, J. Becerra González, P. Antoranz, Amy Furniss, S. P. Wakely, B. Jordan, Elena G. Larionova, Xuhui Chen, H. C. Lin, Geza Gyuk, Louis Antonelli, Michele Doro, Abelardo Moralejo, Jelena Aleksić, S. McArthur, M. L. Knoetig, P. G. Prada Moroni, P. Munar-Adrover, Ivica Puljak, E. Collins-Hughes, K. Meagher, Nikola Godinovic, Benito Marcote, T. Steinbring, W. Idec, M. V. Fonseca, Pierre Colin, P. Temnikov, M. Hayashida, Patrick Vogler, J. Tyler, A. Niedzwiecki, C. Schultz, V. Scapin, J. H. Buckley, P. Moriarty, Tomislav Terzić, K. Berger, T. Sakamoto, C. Delgado Mendez, S. R. Gozzini, B. McBreen, O. Tibolla, Shan Sun, E. de Oña Wilhelmi, Ivan S. Troitsky, David Paneque, I. Snidaric, Marc Ribó, P. Da Vela, D. Hildebrand, B. Steinke, Steven N. Shore, Q. Feng, K. Frantzen, Massimo Persic, Hidetoshi Kubo, A. Boller, D. A. Morozova, A. Wilhelm, R. Reinthal, Thomas Bretz, Sofia O. Kurtanidze, Kari Nilsson, Elina Lindfors, Justin D. Finke, J. Krause, B. De Lotto, Walter Max-Moerbeck, K. Saito, Razmik Mirzoyan, U. Barres de Almeida, A. González Muñoz, V. Kadenius, Damir Lelas, N. Mankuzhiyil, J. P. Finley, J. S. Perkins, Wen Ping Chen, S. Paiano, E. Lorenz, Karl Mannheim, H. Prokoph, Hanna Kellermann, Daniel Mazin, I. Lozano, Dorota Sobczyńska, J. D. Eisch, Wolfgang Rhode, Daniela Dorner, M. Palatiello, Joseph Moody, Lucy Fortson, M. I. Martínez, M. Gaug, P. Bangale, G. De Caneva, J. Herrera, Matthias Beilicke, Koji Noda, J. Millis, Abraham D. Falcone, Francesco Dazzi, Karlen Shahinyan, Elisa Bernardini, S. Bonnefoy, Sabrina Einecke, J. Rodriguez Garcia, W. Bednarek, Fabrizio Tavecchio, Ll. Font, A. C. Sadun, Anne Lähteenmäki, Stefano Covino, M. J. Lang, A. Varlotta, Masahiro Teshima, A. McCann, Ekaterina Koptelova, A. C. Rovero, J. Kushida, D. Tescaro, Jose Luis Contreras, G. Hughes, M. Uellenbeck, Takashi Saito, Y. Hanabata, A. Popkow, Juan Cortina, V. Bugaev, David Kieda, Reiko Orito, S. Buson, J. L. Richards, Ann E. Wehrle, D. Garrido Terrats, P. Fortin, Oscar Blanch, Ralph Bird, S. Archambault, Valeri M. Larionov, V. Scalzotto, Ana Babić, Julia Thaele, E. Carmona, A. De Angelis, A. Treves, R. A. Ong, G. Maneva, R. Zanin, A. N. Otte, Adrian Biland, J. Rico, Alan P. Marscher, Universitat de Barcelona, Department of Radio Science and Engineering, Aalto-yliopisto, Aalto University, and ~
Subjects: extragalactic background light, Ciencias Físicas, spectral energy-distribution, Flux, Non-thermal / galaxies, Astrophysics, law.invention, Relativistic particle, purl.org/becyt/ford/1 [https], atmospheric cherenkov telescopes, Raigs gamma, bl lacertae objects, law, MAGIC (telescope), Active / BL Lacertae objects, astro-ph.HE, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, individual: Mrk 421 [BL Lacertae objects], education.field_of_study, gamma-ray outburst, non-thermal [radiation mechanisms], BL Lacertae objects: individual: Mrk 421, Galaxies: active, Gamma rays: galaxies, Radiation mechanisms: non-thermal, Astronomy and Astrophysics, Space and Planetary Science, Particle acceleration, NON THERMAL RADIATION, large-area telescope, active [galaxies], galaxies [gamma rays], BL LACERTAE OBJECTS, Electrónica, self-compton model, Electricidad, Astrophysics - High Energy Astrophysical Phenomena, CIENCIAS NATURALES Y EXACTAS, Flare, Astrophysics::High Energy Astrophysical Phenomena, galaxies: active, Population, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Radio telescope, radiation mechanisms: non-thermal, gamma rays: galaxies, Radiation mechanisms, BL Lacertae objects: individual, simultaneous multiwavelength observations, AGN, education, Blazar, Individual: Mrk 421 / gamma rays, tev blazars, Gamma rays, Institut für Physik und Astronomie, purl.org/becyt/ford/1.3 [https], Galaxies, Astronomía, x-ray, Galàxies actives, Active galaxies, ddc:520
Abstract: A flare from the TeV blazar Mrk 421, occurring in March 2010, was observed for 13 consecutive days from radio to very high energy (VHE, E > 100 GeV) gamma-rays with MAGIC, VERITAS, Whipple, FermiLAT, MAXI, RXTE, Swift, GASP-WEBT, and several optical and radio telescopes. We model the day-scale SEDs with one-zone and two-zone synchrotron self-Compton (SSC) models, investigate the physical parameters, and evaluate whether the observed broadband SED variability can be associated to variations in the relativistic particle population. Flux variability was remarkable in the X-ray and VHE bands while it was minor or not significant in the other bands. The one-zone SSC model can describe reasonably well the SED of each day for the 13 consecutive days. This flaring activity is also very well described by a two-zone SSC model, where one zone is responsible for the quiescent emission while the other smaller zone, which is spatially separated from the first one, contributes to the daily-variable emission occurring in X-rays and VHE gamma-rays. Both the one-zone SSC and the two-zone SSC models can describe the daily SEDs via the variation of only four or five model parameters, under the hypothesis that the variability is associated mostly to the underlying particle population. This shows that the particle acceleration and cooling mechanism producing the radiating particles could be the main one responsible for the broadband SED variations during the flaring episodes in blazars. The two-zone SSC model provides a better agreement to the observed SED at the narrow peaks of the low- and high-energy bumps during the highest activity, although the reported one-zone SSC model could be further improved by the variation of the parameters related to the emitting region itself ($\delta$, $B$ and $R$), in addition to the parameters related to the particle population., Comment: Published in A&A, 30 pages, 15 figures, 6 tables. Online-data: multi-wavelength light curves (data in Fig. 1) and broadband spectral energy distributions (the data in Figs. 6, and B1-B4) are available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/578/A22. Corresponding authors: David Paneque (dpaneque@mpp.mpg.de), Shangyu Sun (sysun@mpp.mpg.de), Hajime Takami (takami@post.kek.jp)
Published: 2014
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19. Unprecedented study of the broadband emission of Mrk 421 during flaring activity in March 2010

Author: Antoranz Canales, Pedro, Barrio Uña, Juan Abel, Contreras González, José Luis, Fonseca González, María Victoria, López Moya, Marcos, Miranda Pantoja, José Miguel, Satalecka, Konstanzja, Scapin, Valeria, Antoranz Canales, Pedro, Barrio Uña, Juan Abel, Contreras González, José Luis, Fonseca González, María Victoria, López Moya, Marcos, Miranda Pantoja, José Miguel, Satalecka, Konstanzja, and Scapin, Valeria
Abstract: © ESO 2015. The authors thank the anonymous referee for providing a very detailed and constructive list of remarks that helped us to improve the manuscript. The MAGIC collaboration would like to thank the Instituto de Astrofísica de Canarias for the excellent working conditions at the Observatorio del Roque de los Muchachos in La Palma. The financial support of the German BMBF and MPG, the Italian INFN and INAF, the Swiss National Fund SNF, the ERDF under the Spanish MINECO, and the Japanese JSPS and MEXT is gratefully acknowledged. This work was also supported by the Centro de Excelencia Severo Ochoa SEV-2012-0234, CPAN CSD2007-00042, and MultiDark CSD2009-00064 projects of the Spanish Consolider-Ingenio 2010 programme, by grant 268740 of the Academy of Finland, by the Croatian Science Foundation (HrZZ) Project 09/176 and the University of Rijeka Project 13.12.1.3.02, by the DFG Collaborative Research Centers SFB823/C4 and SFB876/C3, and by the Polish MNiSzW grant 745/N-HESS-MAGIC/2010/0. The VERITAS collaboration acknowledges supports from the grants from the U.S. Department of Energy Office of Science, the U.S. National Science Foundation and the Smithsonian Institution, by NSERC in Canada, by Science Foundation Ireland (SFI 10/RFP/AST2748) and by STFC in the U.K. We acknowledge the excellent work of the technical support staff at the Fred Lawrence Whipple Observatory and at the collaborating institutions in the construction and operation of the instrument. The Fermi LAT collaboration acknowledges generous ongoing support from a number of agencies and institutes that have supported both the development and the operation of the LAT as well as scientific data analysis. These include the National Aeronautics and Space Administration and the Department of Energy in the United States, the Commissariat à l’Energie Atomique and the Centre National de la Recherche Scientifique / Institut National de Physique Nucléaire et de Physique des Particules in France, the Agenzia, Ministerio de Economía y Competitividad (MINECO), German BMBF, German MPG, Italian INFN, Italian INAF, Swiss National Fund SNF, Japanese JSPS and MEXT, Centro de Excelencia Severo Ochoa, Spanish Consolider-Ingenio 2010 programme, Academy of Finland, Croatian Science Foundation (HrZZ), University of Rijeka, DFG Collaborative Research Centers, Polish MNiSzW, U.S. Department of Energy Office of Science, U.S. National Science Foundation, Smithsonian Institution, NSERC in Canada, Science Foundation Ireland, STFC in the U.K., National Aeronautics and Space Administration and the Department of Energy in the United States, Commissariat à l’Energie Atomique and the Centre National de la Recherche Scientifique / Institut National de Physique Nucléaire et de Physique des Particules in France, Agenzia Spaziale Italiana, Istituto Nazionale di Fisica Nucleare in Italy, Ministry of Education, Culture, Sports, Science and Technology (MEXT), High Energy Accelerator Research Organization (KEK, Japan Aerospace Exploration Agency (JAXA) in Japan, K. A. Wallenberg Foundation, Swedish Research Council and the Swedish National Space Board in Sweden, Istituto Nazionale di Astrofisica in Italy, Centre National d’Études Spatiales in France, NASA Fermi Guest Investigator, Smithsonian Astrophysical Observatory, Academia Sinica Institute of Astronomy and Astrophysics, Smithsonian Institution and the Academia Sinica, NASA, NSF, Academy of Finland, Russian RFBR, St.Petersburg University, Georgian National Science Foundation, Shota Rustaveli National Science Foundation, Depto. de Estructura de la Materia, Física Térmica y Electrónica, Fac. de Ciencias Físicas, TRUE, pub
Published: 2015

20. A prototype for the Real-Time analysis of the Cherenkov Telescope Array

Author: Jose Luis Contreras, Juan José Rodríguez-Vázquez, Andrea Bulgarelli, Simon Rosen, Raquel de los Reyes, A. Aboudan, Paola Grandi, S. Buson, Gino Tosti, Andrea Zoli, Domenico Beneventano, Stefan Ohm, Gernot Maier, Sonia Bergamaschi, Vito Conforti, Catherine Boisson, Louis Antonelli, Phil Evans, Martino Marisaldi, Karl Kosack, Giovanni Lamanna, Jürgen Knödlseder, Adriano De Rosa, R. Graciani, Jim Hinton, Nadine Neyroud, Vincenzo Testa, Amanda Weinstein, Denis Bastieri, Alessandro Tacchini, Etienne Lyard, Giovanni De Cesare, Eleonora Torresi, Saverio Lombardi, J. P. Dumm, Lucy Fortson, J. P. Osborne, Giuseppe Malaguti, Matthias Fuessling, Jean Jacquemier, Fulvio Gianotti, Alessandro Carosi, Brian Humensky, Jerzy Burkowski, M. Trifoglio, Luciano Nicastro, Valentina Fioretti, and Matteo Interlandi
Subjects: Cherenkov Telescope Array, Pipeline (computing), Interface (computing), Real-time computing, Cherenkov telescopes, gamma-ray flares, GPU, Intel/Phi, real-time Analysis, science alert system, VHE gamma-ray astronomy, 01 natural sciences, 7. Clean energy, Software, Observatory, 0103 physical sciences, 11. Sustainability, 010303 astronomy & astrophysics, Throughput (business), Physics, 010308 nuclear & particles physics, business.industry, Astronomy, Computer data storage, Software design pattern, Física nuclear, DataBase, Atmospheric Cherenkov telescopes, Observatories, Algorithms, Telescopes, Computer hardware, Data storage, Gamma radiation, Interfaces, business
Abstract: The Cherenkov Telescope Array (CTA) observatory will be one of the biggest ground-based very-high-energy (VHE) gamma-ray observatory. CTA will achieve a factor of 10 improvement in sensitivity from some tens of GeV to beyond 100 TeV with respect to existing telescopes. The CTA observatory will be capable of issuing alerts on variable and transient sources to maximize the scientific return. To capture these phenomena during their evolution and for effective communication to the astrophysical community, speed is crucial. This requires a system with a reliable automated trigger that can issue alerts immediately upon detection of gamma-ray flares. This will be accomplished by means of a Real-Time Analysis (RTA) pipeline, a key system of the CTA observatory. The latency and sensitivity requirements of the alarm system impose a challenge because of the anticipated large data rate, between 0.5 and 8 GB/s. As a consequence, substantial efforts toward the optimization of high-throughput computing service are envisioned. For these reasons our working group has started the development of a prototype of the Real-Time Analysis pipeline. The main goals of this prototype are to test: (i) a set of frameworks and design patterns useful for the inter-process communication between software processes running on memory; (ii) the sustainability of the foreseen CTA data rate in terms of data throughput with different hardware (e.g. accelerators) and software configurations, (iii) the reuse of non-real-time algorithms or how much we need to simplify algorithms to be compliant with CTA requirements, (iv) interface issues between the different CTA systems. In this work we focus on goals (i) and (ii).
Published: 2014

21. Discovery of TeV Gamma-ray Emission from CTA 1 by VERITAS

Author: A. N. Otte, G. H. Sembroski, M. P. Connolly, E. Aliu, T. J. N. Nelson, R. Welsing, K. Lee, L. Ciupik, M. Theiling, P. Moriarty, Eric V. Gotthelf, Geza Gyuk, N. Karlsson, J. P. Finley, Wei Cui, Q. Feng, Gernot Maier, T. C. Weekes, I. Telezhinsky, Jamie Holder, S. Thibadeau, D. Gall, Oleg Kargaltsev, A. O'Faolain de Bhroithe, H. Krawczynski, A. Furniss, N. Galante, S. P. Wakely, R. Mukherjee, R. A. Ong, E. Roache, R. Dickherber, H. Prokoph, S. Vincent, A. S. Madhavan, Wystan Benbow, Abraham D. Falcone, S. Griffin, G. Finnegan, A. W. Smith, Mallory S. E. Roberts, S. McArthur, C. Duke, B. Zitzer, P. T. Reynolds, P. Kaaret, K. Ragan, J. Tyler, F. Krennrich, Y. Khassen, M. Schroedter, A. Bouvier, Vikram V. Dwarkadas, M. Vivier, J. Grube, M. Beilicke, Manel Errando, D. Staszak, S. Federici, J. H. Buckley, P. Majumdar, J. S. Perkins, David Kieda, D. B. Saxon, E. Collins-Hughes, Luis C. Reyes, N. H. Park, David A. Williams, Patrick Slane, M. Orr, T. B. Humensky, T. Aune, S. Godambe, G. Hughes, T. Arlen, Lucy Fortson, A. Cesarini, John L. Quinn, Martin Pohl, J. Dumm, Vladimir Vassiliev, A. Varlotta, M. J. Lang, A. Weinstein, K. Tsurusaki, G. H. Gillanders, D. S. Hanna, G. Tešić, V. Bugaev, S. Archambault, and A. McCann
Subjects: catalog, gamma-rays: stars, Photon, Astrophysics::High Energy Astrophysical Phenomena, supernova remnant cta-1, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Pulsar wind nebula, atmospheric cherenkov telescopes, Pulsar, Observatory, hess j1825-137, evolution, 0103 physical sciences, pulsations, crab-nebula, Supernova remnant, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Spectral index, pulsars: individual (psr j0007+7303), 010308 nuclear & particles physics, Gamma ray, Astronomy and Astrophysics, x-rays: individual (rx j0007.0+7303), astronomy, supernovae: individual (g119.5+10.2), x-ray, Space and Planetary Science, ddc:520, High Energy Physics::Experiment, Astrophysics - High Energy Astrophysical Phenomena, pulsar-wind nebulae, Fermi Gamma-ray Space Telescope
Abstract: We report the discovery of TeV gamma-ray emission coincident with the shell-type radio supernova remnant (SNR) CTA 1 using the VERITAS gamma-ray observatory. The source, VER J0006+729, was detected as a 6.5 standard deviation excess over background and shows an extended morphology, approximated by a two-dimensional Gaussian of semi-major (semi-minor) axis 0.30 degree (0.24 degree) and a centroid 5' from the Fermi gamma-ray pulsar PSR J0007+7303 and its X-ray pulsar wind nebula (PWN). The photon spectrum is well described by a power-law dN/dE = N_0 (E/3 TeV)^(-\Gamma), with a differential spectral index of \Gamma = 2.2 +- 0.2_stat +- 0.3_sys, and normalization N_0 = (9.1 +- 1.3_stat +- 1.7_sys) x 10^(-14) cm^(-2) s^(-1) TeV^(-1). The integral flux, F_\gamma = 4.0 x 10^(-12) erg cm^(-2) s^(-1) above 1 TeV, corresponds to 0.2% of the pulsar spin-down power at 1.4 kpc. The energetics, co-location with the SNR, and the relatively small extent of the TeV emission strongly argue for the PWN origin of the TeV photons. We consider the origin of the TeV emission in CTA 1., Comment: 10 pages, 9 figures, accepted for publication in ApJ
Published: 2012
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22. Performance of the MAGIC stereo system obtained with Crab Nebula data

Author: J. M. Paredes, Antonio Stamerra, Aldo Treves, Daniel Nieto, V. Scalzotto, Daniela Dorner, Abelardo Moralejo, J. Storz, Thomas Bretz, S. N. Shore, Riccardo Paoletti, D. Häfner, R. Mirzoyan, S. Partini, Hanna Kellermann, D. Höhne-Mönch, Ignasi Reichardt, Masahiro Teshima, Petar Temnikov, W. Bednarek, Igor Oya, Fabrizio Tavecchio, Elisa Bernardini, Silvia Pardo, Pierre Colin, Ll. Font, M. Martı´nez, P. Antoranz, E. A. Alvarez, Konstancja Satalecka, A. Boller, Wolfgang Rhode, Elina Lindfors, K. Saito, L. Cossio, J. Moldón, M. Uellenbeck, Gianluca Giavitto, E. Colombo, Michele Doro, Kari Nilsson, Hiroko Miyamoto, Jelena Aleksić, D. Dominis Prester, Daniel Mazin, G. Maneva, Julian Sitarek, Fabio Zandanel, A. Saggion, Patrick Vogler, Dario Hrupec, Nikola Godinovic, M. Asensio, M. Salvati, Adrian Biland, Oscar Blanch, Ralph Bock, L. O. Takalo, Elisa Prandini, M. A. Perez-Torres, Daniela Hadasch, T. Schweizer, M. Shayduk, Artemio Herrero, David Paneque, R. Reinthal, Louis Antonelli, Jose Luis Contreras, Francisco Prada, Stefano Covino, Mosè Mariotti, Juan Cortina, A. De Angelis, Nijil Mankuzhiyil, I. Snidaric, Damir Lelas, Diego F. Torres, P. Munar-Adrover, A. Cañellas, C. Delgado Mendez, M. Pasanen, Dorota Sobczyńska, Michael Backes, J. Krause, R. J. García López, B. De Lotto, Francesco Dazzi, K. Berger, Victor Zabalza, G. De Caneva, S. Spiro, E. Lorenz, E. Carmona, A. Diago Ortega, Robert Wagner, Markus Garczarczyk, Saverio Lombardi, E. Leonardo, D. Tescaro, M. Makariev, M. Pilia, J. Pochon, A. Sillanpää, Victor Stamatescu, Felix Spanier, J. Rico, D. Hildebrand, L. Peruzzo, Takashi Saito, P. G. Prada Moroni, R. Zanin, B. Huber, O. Tibolla, Reiko Orito, Daniel Ferenc, H. Vankov, Ilana M. Braun, Massimo Persic, T. Krähenbühl, S. Klepser, G. Bonnoli, M. V. Fonseca, N. Strah, Christian Fruck, T. Jogler, B. Steinke, M. López, S. Rügamer, Juan Abel Barrio, D. Borla Tridon, I. Puljak, A. La Barbera, J. Becerra González, Mario Meucci, M. Doert, Denis Bastieri, Q. Weitzel, Tihomir Surić, Karl Mannheim, Marc Ribó, Andrei Berdyugin, J. Hose, A. López-Oramas, D. Elsaesser, Alessandro Carosi, D. Garrido, Jose Miguel Miranda, C. Schultz, V. Scapin, Felicitas Pauss, L. Maraschi, Hajime Takami, Tomislav Terzić, E. De Cea del Pozo, and A. Domi´nguez
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Flux, FOS: Physical sciences, Stereoscopy, Astrophysics, gamma ray astronomy, Cosmic rays, IMAGING CHERENKOV DETECTOR, 01 natural sciences, Neutron stars, law.invention, law, Gamma ray astronomy, 0103 physical sciences, Astronomia de raigs gamma, Astrophysics::Solar and Stellar Astrophysics, Angular resolution, MAGIC (telescope), 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Zenith, Cherenkov radiation, Astrophysics::Galaxy Astrophysics, Estels de neutrons, Physics, 010308 nuclear & particles physics, ATMOSPHERIC CHERENKOV TELESCOPES, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Astronomy and Astrophysics, Gamma-ray astronomy, PULSAR, gamma-ray astronomy, Cherenkov telescopes, Crab Nebula, ARRAYS, ddc:540, FLARES, TEV, Electrónica, Física nuclear, Astrophysics::Earth and Planetary Astrophysics, Electricidad, Astrophysics - Instrumentation and Methods for Astrophysics, GAMMA-RAY EMISSION, astro-ph.IM
Abstract: MAGIC is a system of two Imaging Atmospheric Cherenkov Telescopes located in the Canary island of La Palma. Since autumn 2009 both telescopes have been working together in stereoscopic mode, providing a significant improvement with respect to the previous single-telescope observations. We use observations of the Crab Nebula taken at low zenith angles to assess the performance of the MAGIC stereo system. The trigger threshold of the MAGIC telescopes is 50-60 GeV. Advanced stereo analysis techniques allow MAGIC to achieve a sensitivity as good as (0.76 +/- 0.03)% of the Crab Nebula flux in 50 h of observations above 290 GeV. The angular resolution at those energies is better than ~0.07 degree. We also perform a detailed study of possible systematic effects which may influence the analysis of the data taken with the MAGIC telescopes., Comment: 15 pages, 19 figures, 4 tables, added run-by-run systematics study, and the study of angular resolution as the function of the distance to the camera centre, accepted for publication in Astroparticle Physics
Published: 2012
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23. Constraints on Cosmic Rays, Magnetic Fields, and Dark Matter from Gamma-Ray Observations of the Coma Cluster of Galaxies with VERITAS and Fermi

Author: T. Arlen, T. Aune, M. Beilicke, W. Benbow, A. Bouvier, J. H. Buckley, V. Bugaev, K. Byrum, A. Cannon, A. Cesarini, L. Ciupik, E. Collins-Hughes, M. P. Connolly, W. Cui, R. Dickherber, J. Dumm, A. Falcone, S. Federici, Q. Feng, J. P. Finley, G. Finnegan, L. Fortson, A. Furniss, N. Galante, D. Gall, S. Godambe, S. Griffin, J. Grube, G. Gyuk, J. Holder, H. Huan, G. Hughes, T. B. Humensky, A. Imran, P. Kaaret, N. Karlsson, M. Kertzman, Y. Khassen, D. Kieda, H. Krawczynski, F. Krennrich, K. Lee, A. S Madhavan, G. Maier, P. Majumdar, S. McArthur, A. McCann, P. Moriarty, R. Mukherjee, T. Nelson, A. O’Faoláin de Bhróit, R. A. Ong, M. Orr, A. N. Otte, N. Park, J. S. Perkins, M. Pohl, H. Prokoph, J. Quinn, K. Ragan, L. C. Reyes, P. T. Reynolds, E. Roache, J. Ruppel, D. B. Saxon, M. Schroedter, G. H. Sembroski, C. Skole, A. W. Smith, I. Telezhinsky, G. Tešić, M. Theiling, S. Thibadeau, K. Tsurusaki, A. Varlotta, M. Vivier, S. P. Wakely, J. E. Ward, A. Weinstein, R. Welsing, D. A. Williams, B. Zitzer, C. Pfrommer, and A. Pinzke
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO), Astrophysics::High Energy Astrophysical Phenomena, Dark matter, nonthermal emission, FOS: Physical sciences, Coma (optics), Cosmic ray, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, galaxies: clusters: individual (coma (aco 1656)), magnetic fields, dark matter, large-scale structure, shock-waves, atmospheric cherenkov telescopes, diffuse radio-emission, cosmic rays, all-sky survey, Coma Cluster, upper limits, galactic-center, Galaxy cluster, Cherenkov radiation, gamma rays: galaxies: clusters, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Institut für Physik und Astronomie, Astronomy and Astrophysics, source catalog, Galaxy, x-ray, galaxies: clusters: general, Space and Planetary Science, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Nongalactic Astrophysics, Fermi Gamma-ray Space Telescope
Abstract: Observations of radio halos and relics in galaxy clusters indicate efficient electron acceleration. Protons should likewise be accelerated, suggesting that clusters may also be sources of very high-energy (VHE; E>100 GeV) gamma-ray emission. We report here on VHE gamma-ray observations of the Coma galaxy cluster with the VERITAS array of imaging Cherenkov telescopes, with complementing Fermi-LAT observations at GeV energies. No significant gamma-ray emission from the Coma cluster was detected. Integral flux upper limits at the 99% confidence level were measured to be on the order of (2-5)*10^-8\ ph. m^-2 s^-1 (VERITAS, >220 GeV} and ~2*10^-6 ph. m^-2 s^-1 (Fermi, 1-3 GeV), respectively. We use the gamma-ray upper limits to constrain CRs and magnetic fields in Coma. Using an analytical approach, the CR-to-thermal pressure ratio is constrained to be < 16% from VERITAS data and < 1.7% from Fermi data (averaged within the virial radius). These upper limits are starting to constrain the CR physics in self-consistent cosmological cluster simulations and cap the maximum CR acceleration efficiency at structure formation shocks to be, ApJ in press
Published: 2012
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24. The discovery of g-ray emission from the Blazar RGB J0710+591

Author: Acciari1, V. A., Aliu2, E., Arlen3, T., Aune4, T., Bautista5, M., Beilicke6, M., Benbow1, W., Böttcher7, M., Boltuch8, D., Bradbury9, S. M., Buckley6, J. H., Bugaev6, V., Byrum10, K., Cannon11, A., Cesarini12, A., Ciupik13, L., Cui14, W., Dickherber6, R., Duke15, C., Falcone16, A., Finley14, J. P., Finnegan17, G., Fortson13, L., Furniss4, A., Galante1, N., Gall14, D., Gibbs1, K., Gillanders12, G. H., Godambe17, S., Grube11, J., Guenette5, R., Gyuk13, G., Hanna5, D., Holder8, J., Hui17, C. M., Humensky18, T. B., Imran19, A., Kaaret20, P., Karlsson13, N., Kertzman21, M., Kieda17, D., Konopelko22, A., Krawczynski6, H., Krennrich19, F., Lang12, M. J., Lamerato7, A., Lebohec17, S., Maier5, G., Mcarthur6, S., Mccann5, A., Mccutcheon5, M., Moriarty23, P., Mukherjee2, R., Ong3, R. A., Otte4, A. N., Pandel20, D., Perkins1, J. S., Petry24, D., Pichel25, A., Pohl19, M., Quinn11, J., Ragan5, K., Reyes26, L. C., Reynolds27, P. T., Roache1, E., Rose9, H. J., Roustazadeh7, P., Schroedter19, M., Sembroski14, G. H., Demet Senturk28, G., Smith10, A. W., Steele13, D., Swordy18, S. P., Tešić5, G., Theiling1, M., Thibadeau6, S., Varlotta14, A., Vassiliev3, V. V., Vincent17, S., Wagner10, R. G., Wakely18, S. P., Ward11, J. E., Weekes1, T. C., Weinstein3, A., Weisgarber18, T., Williams4, D. A., Wissel18, S., Wood3, M., Zitzer14, B., Ackermann29, M., Ajello29, M., Antolini30, E., Baldini32, L., Ballet33, J., Barbiellini34, G., Bastieri36, D., Bechtol29, K., Bellazzini32, R., Berenji29, B., Blandford29, R. D., Bloom29, E. D., Bonamente, Emanuele, Borgland29, A. W., Bouvier29, A., Bregeon32, J., Brigida38, M., Bruel40, P., Buehler29, R., Buson36, S., Caliandro41, G. A., Cameron29, R. A., Caraveo42, P. A., Carrigan37, S., Casandjian33, J. M., Cavazzuti43, E., Cecchi, Claudia, Çelik44, Ö., 46, 45, Charles29, E., Chekhtman47, A., Cheung47, C. C., Chiang29, J., Ciprini31, S., Claus29, R., Cohen Tanugi50, J., Conrad51, J., 84, 52, Dermer47, C. D., de Palma38, F., Silva29, E. do Couto e., Drell29, P. S., Dubois29, R., Dumora53, D., Farnier50, C., Favuzzi38, C., Fegan40, S. J., Fortin40, P., Frailis55, M., Fukazawa57, Y., Funk29, S., Fusco38, P., Gargano39, F., Gasparrini43, D., Gehrels44, N., Germani30, S., Giebels40, B., Giglietto38, N., Giordano38, F., Giroletti58, M., Glanzman29, T., Godfrey29, G., Grenier33, I. A., Grove47, J. E., Guiriec59, S., Hays44, E., Horan40, D., Hughes60, R. E., Jóhannesson29, G., Johnson29, A. S., Johnson47, W. N., Kamae29, T., Katagiri57, H., Kataoka61, J., Knödlseder62, J., Kuss32, M., Lande29, J., Latronico32, L., Lee29, S. H., Llena Garde51, M., Longo34, F., Loparco38, F., Lott53, B., Lovellette47, M. N., Lubrano30, P., Makeev47, A., Mazziotta39, M. N., Michelson29, P. F., Mitthumsiri29, W., Mizuno57, T., Moiseev45, A. A., Monte38, C., Monzani29, M. E., Morselli64, A., Moskalenko29, I. V., Murgia29, S., Nolan29, P. L., Norris65, J. P., Nuss50, E., Ohno66, M., Ohsugi67, T., Omodei29, N., Orlando68, E., Ormes65, J. F., Paneque29, D., Panetta29, J. H., Pelassa50, V., Pepe30, M., Pesce Rollins32, M., Piron50, F., Porter29, T. A., Rainò38, S., Rando36, R., Razzano32, M., Reimer69, A., Reimer69, O., Ripken51, J., Rodriguez41, A. Y., Roth70, M., Sadrozinski71, H. F. W., Sanchez40, D., Sander60, A., Scargle72, J. D., Sgrò32, C., Siskind73, E. J., Smith60, P. D., Spandre32, G., Spinelli38, P., Strickman47, M. S., Suson74, D. J., Takahashi67, H., Tanaka29, T., Thayer29, J. B., Thayer29, J. G., Thompson44, D. J., Tibaldo33, L., 37, 36, Torres41, D. F., Tosti, Gino, Tramacere29, A., 77, 76, Usher29, T. L., Vasileiou45, V., Vilchez62, N., Vitale64, V., Waite29, A. P., Wang29, P., Winer60, B. L., Wood47, K. S., Yang51, Z., Ylinen52, T., 80, 79, Ziegler71, M., Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Théorique et Astroparticules (LPTA), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre d'étude spatiale des rayonnements (CESR), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Acciari, V. A., Aliu, E., Arlen, T., Aune, T., Bautista, M., Beilicke, M., Benbow, W., Bottcher, M., Boltuch, D., Bradbury, S. M., Buckley, J. H., Bugaev, V., Byrum, K., Cannon, A., Cesarini, A., Ciupik, L., Cui, W., Dickherber, R., Duke, C., Falcone, A., Finley, J. P., Finnegan, G., Fortson, L., Furniss, A., Galante, N., Gall, D., Gibbs, K., Gillanders, G. H., Godambe, S., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Holder, J., Hui, C. M., Humensky, T. B., Imran, A., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., Lamerato, A., Lebohec, S., Maier, G., Mcarthur, S., Mccann, A., Mccutcheon, M., Moriarty, P., Mukherjee, R., Ong, R. A., Otte, A. N., Pandel, D., Perkins, J. S., Petry, D., Pichel, A., Pohl, M., Quinn, J., Ragan, K., Reyes, L. C., Reynolds, P. T., Roache, E., Rose, H. J., Roustazadeh, P., Schroedter, M., Sembroski, G. H., Senturk, G. D., Smith, A. W., Steele, D., Swordy, S. P., Tesic, G., Theiling, M., Thibadeau, S., Varlotta, A., Vassiliev, V. V., Vincent, S., Wagner, R. G., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., Weisgarber, T., Williams, D. A., Wissel, S., Wood, M., Zitzer, B., Ackermann, M., Ajello, M., Antolini, E., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Bouvier, A., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Carrigan, S., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Celik, O., Charles, E., Chekhtman, A., Cheung, C. C., Chiang, J., Ciprini, S., Claus, R., Cohen Tanugi, J., Conrad, J., Dermer, C. D., Palma, F. d., Silva, E. D. E., Drell, P. S., Dubois, R., Dumora, D., Farnier, C., Favuzzi, C., Fegan, S. J., Fortin, P., Frailis, M., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giebels, B., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grove, J. E., Guiriec, S., Hays, E., Horan, D., Hughes, R. E., Johannesson, G., Johnson, A. S., Johnson, W. N., Kamae, T., Katagiri, H., Kataoka, J., Knodlseder, J., Kuss, M., Lande, J., Latronico, L., Lee, S. H., Garde, M. L., Longo, Francesco, Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Makeev, A., Mazziotta, M. N., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nolan, P. L., Norris, J. P., Nuss, E., Ohno, M., Ohsugi, T., Omodei, N., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Pelassa, V., Pepe, M., Pesce Rollins, M., Piron, F., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Ripken, J., Rodriguez, A. Y., Roth, M., Sadrozinski, H. F. W., Sanchez, D., Sander, A., Scargle, J. D., Sgro, C., Siskind, E. J., Smith, P. D., Spandre, G., Spinelli, P., Strickman, M. S., Suson, D. J., Takahashi, H., Tanaka, T., Thayer, J. B., Thayer, J. G., Thompson, D. J., Tibaldo, L., Torres, D. F., Tosti, G., Tramacere, A., Usher, T. L., Vasileiou, V., Vilchez, N., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Yang, Z., Ylinen, T., Ziegler, M., Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)
Subjects: [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Ciencias Físicas, bl-lacertae objects, Fermi satellite, Astrophysics, 7. Clean energy, 01 natural sciences, High Energy Gamma-ray Astronomy, law.invention, purl.org/becyt/ford/1 [https], atmospheric cherenkov telescopes, law, 010303 astronomy & astrophysics, BL Lacertae objects: individual (RGB J0710+591, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Spectral index, [SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Gamma ray, lac objects, astronomy, individual (RGB J0710+591, VER J0710+591) [BL Lacertae objects], galaxies [gamma rays], Spectral energy distribution, host galaxies, constraints, Astrophysics - High Energy Astrophysical Phenomena, CIENCIAS NATURALES Y EXACTAS, Astrophysics - Cosmology and Nongalactic Astrophysics, BL Lac object, VER J0710+591), [PHYS.ASTR.HE]Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Cosmology and Nongalactic Astrophysics (astro-ph.CO), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Telescope, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], veritas, 0103 physical sciences, gamma rays: galaxies, BL Lacertae objects: individual (RGB J0710+591, VER J0710+591), Blazar, Astrophysics::Galaxy Astrophysics, 010308 nuclear & particles physics, bl lacertae objects: individual (rgb j0710+591, ver j0710+591), background-radiation, Astronomy and Astrophysics, Active Galactic Nuclei, purl.org/becyt/ford/1.3 [https], sample, Astronomía, Crab Nebula, 13. Climate action, Space and Planetary Science, Very High Energy Gamma-ray Astronomy, ddc:520, Fermi Gamma-ray Space Telescope
Abstract: The high-frequency-peaked BL Lacertae object RGB J0710+591 was observed in the very high-energy (VHE; E > 100 GeV) wave band by the VERITAS array of atmospheric Cherenkov telescopes. The observations, taken between 2008 December and 2009 March and totaling 22.1 hr, yield the discovery of VHE gamma rays from the source. RGB J0710+591 is detected at a statistical significance of 5.5 standard deviations (5.5σ) above the background, corresponding to an integral flux of (3.9 ± 0.8) × 10−12 cm−2 s−1 (3% of the Crab Nebula’s flux) above 300 GeV. The observed spectrum can be fit by a power law from 0.31 to 4.6 TeV with a photon spectral index of 2.69 ± 0.26stat ± 0.20sys. These data are complemented by contemporaneous multiwavelength data from the Fermi Large Area Telescope, the Swift X-ray Telescope, the Swift Ultra-Violet and Optical Telescope, and the Michigan–Dartmouth–MIT observatory. Modeling the broadband spectral energy distribution (SED) with an equilibrium synchrotron self-Compton model yields a good statistical fit to the data. The addition of an external-Compton component to the model does not improve the fit nor brings the system closer to equipartition. The combined Fermi and VERITAS data constrain the properties of the high-energy emission component of the source over 4 orders of magnitude and give measurements of the rising and falling sections of the SED. Fil: Acciari, V. A.. Harvard-Smithsonian Center for Astrophysics; Estados Unidos Fil: Aliu, E.. Columbia University; Estados Unidos Fil: Arlen, T.. University of California; Estados Unidos Fil: Aune, T.. University of California; Estados Unidos Fil: Bautista, M.. McGill University; Canadá Fil: Beilicke, M.. University of Washington; Estados Unidos Fil: Benbow, W.. Harvard-Smithsonian Center for Astrophysics; Estados Unidos Fil: Bottcher, M.. Ohio University; Estados Unidos Fil: Boltuch, D.. University of Delaware; Estados Unidos Fil: Bradbury, S. M.. University of Leeds; Reino Unido Fil: Buckley, J. H.. University of Washington; Estados Unidos Fil: Bugaev, V.. University of Washington; Estados Unidos Fil: Byrum, K.. Argonne National Laboratory; Estados Unidos Fil: Cannon, A.. University College Dublin; Irlanda Fil: Cesarini, A.. National University of Ireland Galway; Irlanda Fil: Ciupik, L.. Adler Planetarium and Astronomy Museum; Estados Unidos Fil: Cui, W.. Purdue University; Estados Unidos Fil: Dickherber, R.. University of Washington; Estados Unidos Fil: Duke, C.. Grinnell College; Estados Unidos Fil: Falcone, A.. State University Of Pennsylvania; Estados Unidos Fil: Finley, J. P.. Purdue University; Estados Unidos Fil: Finnegan, G.. University of Utah; Estados Unidos Fil: Fortson, L.. Adler Planetarium and Astronomy Museum; Estados Unidos Fil: Furniss, A.. University of California; Estados Unidos Fil: Galante, N.. Harvard-Smithsonian Center for Astrophysics; Estados Unidos Fil: Gall, D.. Purdue University; Estados Unidos Fil: Gibbs, K.. Harvard-Smithsonian Center for Astrophysics; Estados Unidos Fil: Gillanders, G. H.. National University of Ireland Galway; Irlanda Fil: Godambe, S.. University of Utah; Estados Unidos Fil: Pichel, Ana Carolina. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentina Fil: The Veritas Collaboration.
Published: 2010
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25. Veritas upper limit on the very high energy emission from the radio galaxy NGC 1275

Author: V. A. Acciari, E. Aliu, T. Arlen, T. Aune, M. Bautista, M. Beilicke, W. Benbow, D. Boltuch, S. M. Bradbury, J. H. Buckley, V. Bugaev, K. Byrum, A. Cannon, O. Celik, A. Cesarini, L. Ciupik, P. Cogan, W. Cui, R. Dickherber, C. Duke, S. J. Fegan, J. P. Finley, P. Fortin, L. Fortson, A. Furniss, N. Galante, D. Gall, K. Gibbs, G. H. Gillanders, S. Godambe, J. Grube, R. Guenette, G. Gyuk, D. Hanna, J. Holder, D. Horan, C. M. Hui, T. B. Humensky, A. Imran, P. Kaaret, N. Karlsson, M. Kertzman, D. Kieda, A. Konopelko, H. Krawczynski, F. Krennrich, M. J. Lang, S. LeBohec, G. Maier, A. McCann, M. McCutcheon, J. Millis, P. Moriarty, R. Mukherjee, R. A. Ong, A. N. Otte, D. Pandel, J. S. Perkins, M. Pohl, J. Quinn, K. Ragan, P. T. Reynolds, E. Roache, H. J. Rose, M. Schroedter, G. H. Sembroski, A. W. Smith, D. Steele, S. P. Swordy, M. Theiling, J. A. Toner, A. Varlotta, V. V. Vassiliev, S. Vincent, R. G. Wagner, S. P. Wakely, J. E. Ward, T. C. Weekes, A. Weinstein, T. Weisgarber, D. A. Williams, S. Wissel, M. Wood, B. Zitzer, J. Kataoka, E. Cavazzuti, C. C. Cheung, B. Lott, D. J. Thompson, G. Tosti, Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), and Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
Subjects: jets, [PHYS.ASTR.HE]Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Active galactic nucleus, Radio galaxy, Perseus A), Astrophysics::High Energy Astrophysical Phenomena, Flux, proton blazar, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, law.invention, galaxies: individual: NGC 1275 3C 84 Perseus A, Telescope, atmospheric cherenkov telescopes, Spitzer Space Telescope, law, 0103 physical sciences, 3C 84, Limit (mathematics), galaxies: Seyfert, gamma rays: observations, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Physics, parameters, 010308 nuclear & particles physics, [SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], galaxies: individual (NGC 1275, Astronomy and Astrophysics, gamma-ray emission, galaxies: individual (ngc 1275, 3c 84, perseus a), radiation, Crab Nebula, Space and Planetary Science, markarian-501, active galactic nuclei, peaked bl-lacertae, discovery, Fermi Gamma-ray Space Telescope
Abstract: The recent detection by the Fermi gamma-ray space telescope of high-energy gamma-rays from the radio galaxy NGC 1275 makes the observation of the very high energy (VHE: E > 100 GeV) part of its broadband spectrum particularly interesting, especially for the understanding of active galactic nuclei (AGN) with misaligned multi-structured jets. The radio galaxy NGC 1275 was recently observed by VERITAS at energies above 100 GeV for about 8 hours. No VHE gamma-ray emission was detected by VERITAS from NGC 1275. A 99% confidence level upper limit of 2.1% of the Crab Nebula flux level is obtained at the decorrelation energy of approximately 340 GeV, corresponding to 19% of the power-law extrapolation of the Fermi Large Area Telescope (LAT) result.
Published: 2009
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26. Veritas observations of a very high energy γ-ray flare from the blazar 3c 66a

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

27. Design of light concentrators for Cherenkov telescope observatories

Author: Henault, Franois, Petrucci, Pierre-Olivier, Jocou, Laurent, Khelifi, Bruno, Manigot, Pascal, Hormigos, Stephane, Knoedlseder, Juergen, Olive, Jean-Francois, Jean, Pierre, Punch, Michael, Henault, Franois, Petrucci, Pierre-Olivier, Jocou, Laurent, Khelifi, Bruno, Manigot, Pascal, Hormigos, Stephane, Knoedlseder, Juergen, Olive, Jean-Francois, Jean, Pierre, and Punch, Michael
Abstract: The Cherenkov Telescope Array (CTA) will be the largest cosmic gamma ray detector ever built in the world. It will be installed at two different sites in the North and South hemispheres and should be operational for about 30 years. In order to cover the desired energy range, the CTA is composed of typically 50-100 collecting telescopes of various sizes (from 6 to 24-m diameters). Most of them are equipped with a focal plane camera consisting of 1500 to 2000 Photomultipliers (PM) equipped with light concentrating optics, whose double function is to maximize the amount of Cherenkov light detected by the photo-sensors, and to block any stray light originating from the terrestrial environment. Two different optical solutions have been designed, respectively based on a Compound Parabolic Concentrator (CPC), and on a purely dioptric concentrating lens. In this communication are described the technical specifications, optical designs and performance of the different solutions envisioned for all these light concentrators. The current status of their prototyping activities is also given.
Published: 2013
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28. Performance of the MAGIC stereo system obtained with Crab Nebula data

Author: Antoranz Canales, Pedro, Barrio Uña, Juan Abel, Contreras González, José Luis, Fonseca González, María Victoria, López Moya, Marcos, Miranda Pantoja, José Miguel, Nieto Castaño, Daniel, Satalecka, Konstanzja, Scapin, Valeria, Antoranz Canales, Pedro, Barrio Uña, Juan Abel, Contreras González, José Luis, Fonseca González, María Victoria, López Moya, Marcos, Miranda Pantoja, José Miguel, Nieto Castaño, Daniel, Satalecka, Konstanzja, and Scapin, Valeria
Abstract: © 2011 Elsevier B.V. We would like to thank the Instituto de Astrofísica de Canarias for the excellent working conditions at the Observatorio del Roque de los Muchachos in La Palma. The support of the German BMBF and MPG, the Italian INFN, the Swiss National Fund SNF, and the Spanish MICINN is gratefully acknowledged.This work was also supported by the Marie Curie program, by the CPAN CSD2007-00042 and MultiDark CSD2009-00064 projects of the Spanish Consolider-Ingenio 2010 programme, by grant DO02-353 of the Bulgarian NSF, by grant 127740 of the Academy of Finland, by the YIP of the Helmholtz Gemeinschaft, by the DFG Cluster of Excellence “Origin and Structure of the Universe”, by the DFG Collaborative Research Centers SFB823/C4 and SFB876/C3, and by the Polish MNiSzW grant 745/N-HESS-MAGIC/2010/0., MAGIC is a system of two Imaging Atmospheric Cherenkov Telescopes located in the Canary island of La Palma. Since autumn 2009 both telescopes have been working together in stereoscopic mode, providing a significant improvement with respect to the previous single-telescope observations. We use observations of the Crab Nebula taken at low zenith angles to assess the performance of the MAGIC stereo system. The trigger threshold of the MAGIC telescopes is 50 - 60 GeV. Advanced stereo analysis techniques allow MAGIC to achieve a sensitivity as good as (0.76 +/- 0.03)% of the Crab Nebula flux in 50 h of observations above 290 GeV. The angular resolution at those energies is better than similar to 0.07 degrees. We also perform a detailed study of possible systematic effects which may influence the analysis of the data taken with the MAGIC telescopes. (C) 2011 Elsevier B.V. All rights reserved., German BMBF, MPG, Italian INFN, Swiss National Fund SNF, Spanish MICINN, Marie Curie program, Spanish Consolider-Ingenio programme, Bulgarian NSF, Academy of Finland, YIP of the Helmholtz Gemeinschaft, DFG Collaborative Research Centers, Polish MNiSzW, Depto. de Estructura de la Materia, Física Térmica y Electrónica, Fac. de Ciencias Físicas, TRUE, pub
Published: 2012

29. Multi-wavelength observations of PKS 2155-304 with H.E.S.S

Author: F. Aharonian, A. G. Akhperjanian, A. R. Bazer-Bachi, M. Beilicke, W. Benbow, D. Berge, K. Bernlöhr, C. Boisson, O. Bolz, V. Borrel, I. Braun, F. Breitling, A. M. Brown, P. M. Chadwick, L.-M. Chounet, R. Cornils, L. Costamante, B. Degrange, H. J. Dickinson, A. Djannati-Ataï, null L. O'C. Drury, G. Dubus, D. Emmanoulopoulos, P. Espigat, F. Feinstein, G. Fontaine, Y. Fuchs, S. Funk, Y. A. Gallant, B. Giebels, S. Gillessen, J. F. Glicenstein, P. Goret, C. Hadjichristidis, M. Hauser, G. Heinzelmann, G. Henri, G. Hermann, J. A. Hinton, W. Hofmann, M. Holleran, D. Horns, A. Jacholkowska, O. C. de Jager, B. Khélifi, Nu. Komin, A. Konopelko, I. J. Latham, R. Le Gallou, A. Lemière, M. Lemoine-Goumard, N. Leroy, T. Lohse, J. M. Martin, O. Martineau-Huynh, A. Marcowith, C. Masterson, T. J. L. McComb, M. de Naurois, S. J. Nolan, A. Noutsos, K. J. Orford, J. L. Osborne, M. Ouchrif, M. Panter, G. Pelletier, S. Pita, G. Pühlhofer, M. Punch, B. C. Raubenheimer, M. Raue, J. Raux, S. M. Rayner, A. Reimer, O. Reimer, J. Ripken, L. Rob, L. Rolland, G. Rowell, V. Sahakian, L. Saugé, S. Schlenker, R. Schlickeiser, C. Schuster, U. Schwanke, M. Siewert, H. Sol, D. Spangler, R. Steenkamp, C. Stegmann, J.-P. Tavernet, R. Terrier, C. G. Théoret, M. Tluczykont, G. Vasileiadis, C. Venter, P. Vincent, null H. J . Völk, S. J. Wagner, Laboratoire Leprince-Ringuet (LLR), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Laboratoire de Physique Théorique et Astroparticules (LPTA), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Pierre et Marie Curie - Paris 6 (UPMC), HESS, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)
Subjects: Energy gamma Rays, Photon, Astrophysics::High Energy Astrophysical Phenomena, Hadron, Proportional counter, FOS: Physical sciences, radiation mechanisms: non thermal, Astrophysics, Synchrotron-proton blazar, 01 natural sciences, galaxie: active, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Tev blazars, Atmospheric Cherenkov telescopes, 0103 physical sciences, X-rays, Radiation mechanisms, High Energy Stereoscopic System, Spectral variability, 010303 astronomy & astrophysics, Observations, BL Lacertae objects: Individual: PKS 2155-304, PKS 2155-304, Physics, Active galactic nuclei, Non thermal, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, BL-LAC objects, Astrophysics (astro-ph), X-rays:galaxies, Astronomy and Astrophysics, 13. Climate action, Space and Planetary Science, Active galaxies, Satellite, Simultaneous x-ray, Kilosecond, gamma rays: observations, BL Lac object
Abstract: The High Energy Stereoscopic System (H.E.S.S.) has observed the high-frequency peaked BL Lac object PKS2155-304 in 2003 between October 19 and November 26 in Very High Energy (VHE) gamma-rays (E>160 GeV for these observations). Observations were carried out simultaneously with the Proportional Counter Array (PCA) on board the Rossi X-ray Timing Explorer satellite (RXTE), the Robotic Optical Transient Search Experiment (ROTSE) and the Nancay decimetric radiotelescope (NRT). Intra-night variability is seen in the VHE band, the source being detected with a high significance on each night it was observed. Variability is also found in the X-ray and optical bands on kilosecond timescales, along with flux-dependent spectral changes in the X-rays. The average H.E.S.S. spectrum shows a very soft power law shape with a photon index of 3.37+/-0.07(stat)+/-0.10(sys). The energy outputs in the 2-10 keV and in the VHE gamma-ray range are found to be similar, with the X-rays and the optical fluxes at a level comparable to some of the lowest historical measurements, indicating that PKS2155-304 was in a low or quiescent state during the observations. Both a leptonic and a hadronic model are used to derive source parameters from these observations., 16 pages, 13 figures, Accepted (June 22) for publication in A&A
Published: 2005
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30. Calibration of cameras of the H.E.S.S. detector

Author: M. Panter, Wystan Benbow, Gilles Henri, J. Raux, G. Fontaine, David Berge, B. Khélifi, C. Borgmeier, G. Hermann, A. Djannati-Ataï, L-M. Chounet, Catherine Boisson, Nu. Komin, Felix Aharonian, Thomas Lohse, C. G. Théoret, P. Goret, I. Redondo, T. J. L. McComb, O. C. de Jager, B. Degrange, Y. A. Gallant, R. Le Gallou, C. Hadjichristidis, M. Siewert, V. Sahakian, S. M. Rayner, Martin Raue, M. de Naurois, O. Bolz, J. Ripken, L. Saugé, Michael Punch, B. C. Raubenheimer, Guy Pelletier, B. Giebels, A. Lemière, Stefan Wagner, Tulun Ergin, D. J. van der Walt, Stefan Funk, A. R. Bazer-Bachi, Conor Masterson, J.-P. Tavernet, P. Vincent, M. Beilicke, Jim Hinton, Helene Sol, I. J. Latham, S. Pita, J. L. Osborne, F. Feinstein, B. Visser, K. J. Orford, M. Lemoine, L. Rob, M. Ouchrif, Martin Pohl, P. M. Chadwick, Werner Hofmann, P. Espigat, Heinrich J. Völk, Luigi Costamante, Julien Guy, M. Rivoal, F. Breitling, Dieter Horns, Gerd Pühlhofer, Olaf Reimer, G. Heinzelmann, G. Vasileiadis, L. O'c. Drury, Klaus-Michael Aye, A. Konopelko, Ullrich Schwanke, Reinhard Schlickeiser, A. G. Akhperjanian, R. Steenkamp, A. Marcowith, P. Berghaus, Gavin Rowell, C. Schuster, A. M. Brown, M. Holleran, S. Schlenker, V. R. Chitnis, C. Stegmann, Stefan Gillessen, I. Jung, N. Leroy, L. Rolland, S. J. Nolan, M. Hauser, R. Cornils, P. Fleury, M. Tluczykont, Konrad Bernlöhr, A. Reimer, A. Noutsos, Physique Corpusculaire et Cosmologie - Collège de France (PCC), Collège de France (CdF (institution))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Théorique et Astroparticules (LPTA), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), HESS, Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Pierre et Marie Curie - Paris 6 (UPMC), and Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)
Subjects: High energy, Photomultiplier, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Optical-system, FOS: Physical sciences, Stereoscopy, Astrophysics, 01 natural sciences, Stability (probability), law.invention, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Optics, Atmospheric Cherenkov telescopes, law, 0103 physical sciences, Calibration, High Energy Stereoscopic System, Performance, 010303 astronomy & astrophysics, Cherenkov radiation, Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, business.industry, Detector, Astrophysics (astro-ph), Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Astronomy and Astrophysics, business
Abstract: H.E.S.S. - the High Energy Stereoscopic System- is a new system of large atmospheric Cherenkov telescopes for GeV/TeV astronomy. Each of the four telescopes of 107 m^2 mirror area is equipped with a 960-pixel photomulitiplier-tube camera. This paper describes the methods used to convert the photomultiplier signals into the quantities needed for Cherenkov image analysis. Two independent calibration techniques have been applied in parallel to provide an estimation of uncertainties. Results on the long-term stability of the H.E.S.S. cameras are also presented., Comment: 29 pages, 13 figures, accepted by Astroparticle Physics
Published: 2004
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30 results on '"atmospheric cherenkov telescopes"'

1. Application of Machine and Deep Learning Methods to the Analysis of IACTs Data

2. The Making of Catalogues of Very-High-Energy γ-ray Sources.

3. Performance of the MAGIC stereo system obtained with Crab Nebula data

4. High-Energy Gamma-Ray Astronomy. Results on Fundamental Questions after 30 Years of Ground-Based Observations.

5. Mirror production for the Cherenkov telescopes of the ASTRI mini-array and the MST project for the Cherenkov Telescope Array

6. Architecture and performance of the KM3NeT front-end firmware

7. Recent Results from VERITAS.

8. The potential for intensity interferometry with γ-ray telescope arrays.

9. Recent Results from CANGAROO.

10. Architecture and performance of the KM3NeT front-end firmware

11. Highlights from VERITAS on VHE gamma-ray sources in our Galaxy.

12. Composite mirror facets for ground based gamma ray astronomy.

13. Pointing of HAGAR telescope mirrors.

14. VERITAS:: STATUS SUMMARY 2009.

15. Image and non-image parameters of atmospheric Cherenkov events: a comparative study of their <f>γ</f>-ray/hadron classification potential in ultrahigh energy regime

16. Upgraded Cameras for the H.E.S.S. Imaging Atmospheric Cherenkov Telescopes

17. The Cherenkov Telescope Array Observatory: top level use cases

18. Unprecedented study of the broadband emission of Mrk 421 during flaring activity in March 2010

19. Unprecedented study of the broadband emission of Mrk 421 during flaring activity in March 2010

20. A prototype for the Real-Time analysis of the Cherenkov Telescope Array

21. Discovery of TeV Gamma-ray Emission from CTA 1 by VERITAS

22. Performance of the MAGIC stereo system obtained with Crab Nebula data

23. Constraints on Cosmic Rays, Magnetic Fields, and Dark Matter from Gamma-Ray Observations of the Coma Cluster of Galaxies with VERITAS and Fermi

24. The discovery of g-ray emission from the Blazar RGB J0710+591

25. Veritas upper limit on the very high energy emission from the radio galaxy NGC 1275

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

27. Design of light concentrators for Cherenkov telescope observatories

28. Performance of the MAGIC stereo system obtained with Crab Nebula data

29. Multi-wavelength observations of PKS 2155-304 with H.E.S.S

30. Calibration of cameras of the H.E.S.S. detector

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30 results on '"atmospheric cherenkov telescopes"'

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