Author: "Barrio, J. A." / Publisher: deutsches elektronen-synchrotron, desy, hamburg - Searchworks@Jio Institute Digital Library Search Results

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57 results on '"Barrio, J. A."'

1. Sensitivity of the Cherenkov Telescope Array to TeV photon emission from the Large Magellanic Cloud

Author: Acharyya, A., Adam, R., Aguasca-Cabot, A., Agudo, I., Aguirre-Santaella, A., Alfaro, J., Aloisio, R., Alves Batista, R., Amato, E., Angüner, E. O., Aramo, C., Arcaro, C., Asano, K., Aschersleben, J., Ashkar, H., Backes, M., Baktash, A., Balazs, C., Balbo, M., Ballet, J., Bamba, A., Larriva, A. Baquero, Barbosa Martins, V., de Almeida, U. Barres, Barrio, J. A., Bastieri, D., Batista, P., Batkovic, I., Baxter, J. R., González, J. Becerra, Becker Tjus, J., Benbow, W., Bernardini, E., Martín, M. I. Bernardos, Medrano, J. Bernete, Berti, A., Bertucci, B., Beshley, V., Bhattacharjee, P., Bhattacharyya, S., Bigongiari, C., Biland, A., Bissaldi, E., Bocchino, F., Bordas, P., Borkowski, J., Bottacini, E., Böttcher, M., Bradascio, F., Brown, A. M., Bulgarelli, A., Burmistrov, L., Caroff, S., Carosi, A., Carquín, E., Casanova, S., Cascone, E., Cassol, F., Cerruti, M., Chadwick, P., Chaty, S., Chen, A., Chiavassa, A., Chytka, L., Conforti, V., Cortina, J., Costa, A., Costantini, H., Cotter, G., Crestan, S., Cristofari, P., D'Ammando, F., Dalchenko, M., Dazzi, F., De Angelis, A., De Caprio, V., de Gouveia Dal Pino, E. M., De Martino, D., de Naurois, M., de Souza, V., del Valle, M. V., Giler, A. G. Delgado, Delgado, C., della Volpe, D., Depaoli, D., Di Girolamo, T., Di Piano, A., Di Pierro, F., Di Tria, R., Di Venere, L., Diebold, S., Doro, M., Dumora, D., Dwarkadas, V. V., Eckner, C., Egberts, K., Emery, G., Escudero, J., Falceta-Goncalves, D., Fedorova, E., Fegan, S., Feng, Q., Ferenc, D., Ferrand, G., Fiandrini, E., Filipovic, M., Fioretti, V., Foffano, L., Fontaine, G., Fukui, Y., Gaggero, D., Galanti, G., Galaz, G., Gallozzi, S., Gammaldi, V., Garczarczyk, M., Gasbarra, C., Gasparrini, D., Ghalumyan, A., Giarrusso, M., Giavitto, G., Giglietto, N., Giordano, F., Giuliani, A., Glicenstein, J.-F., Goldoni, P., Coelho, J. Goulart, Granot, J., Green, D., Green, J. G., Grondin, M.-H., Gueta, O., Hadasch, D., Hamal, P., Hassan, T., Hayashi, K., Heller, M., Cadena, S. Hernández, Hiroshima, N., Hnatyk, B., Hnatyk, R., Hofmann, W., Holder, J., Holler, M., Horan, D., Horvath, P., Hrabovsky, M., Hütten, M., Iarlori, M., Inada, T., Incardona, F., Inoue, S., Iocco, F., Jamrozy, M., Jin, W., Jung-Richardt, I., Juryšek, J., Kantzas, D., Karas, V., Katagiri, H., Kerszberg, D., Knödlseder, J., Komin, N., Kornecki, P., Kosack, K., Kowal, G., Kubo, H., Lamastra, A., Lapington, J., Lemoine-Goumard, M., Lenain, J.-P., Leone, F., Leto, G., Leuschner, F., Lindfors, E., Lohse, T., Lombardi, S., Longo, F., López-Coto, R., López-Oramas, A., Loporchio, S., Luque-Escamilla, P. L., Macias, O., Majumdar, P., Mandat, D., Mangano, S., Manicò, G., Mariotti, M., Marquez, P., Marsella, G., Martí, J., Martin, P., Martínez, M., Mazin, D., Menchiari, S., Meyer, D. M.-A., Miceli, D., Miceli, M., Michałowski, J., Mitchell, A., Moderski, R., Mohrmann, L., Molero, M., Molina, E., Montaruli, T., Moralejo, A., Morcuende, D., Morselli, A., Moulin, E., Moya, V., Mukherjee, R., Munari, K., Muraczewski, A., Nagataki, S., Nakamori, T., Nayak, A., Niemiec, J., Nievas, M., Nikołajuk, M., Nishĳima, K., Noda, K., Nosek, D., Novosyadlyj, B., Nozaki, S., Ohishi, M., Ohm, S., Okumura, A., Olmi, B., Ong, R. A., Orienti, M., Orito, R., Orlandini, M., Orlando, E., Orlando, S., Ostrowski, M., Oya, I., Pagliaro, A., Palatka, M., Pantaleo, F. R., Paoletti, R., Paredes, J. M., Parmiggiani, N., Patricelli, B., Pech, M., Pecimotika, M., Persic, M., Petruk, O., Pierre, E., Pietropaolo, E., Pirola, G., Pohl, M., Prandini, E., Priyadarshi, C., Pühlhofer, G., Pumo, M. L., Punch, M., Queiroz, F. S., Quirrenbach, A., Rainò, S., Rando, R., Razzaque, S., Reimer, A., Reimer, O., Reposeur, T., Ribó, M., Richtler, T., Rico, J., Rieger, F., Rigoselli, M., Rizi, V., Roache, E., Fernandez, G. Rodriguez, Romano, P., Romeo, G., Rosado, J., de Leon, A. Rosales, Rudak, B., Rulten, C., Sadeh, I., Saito, T., Sánchez-Conde, M., Sano, H., Santangelo, A., Santos-Lima, R., Sarkar, S., Saturni, F. G., Scherer, A., Schovanek, P., Schussler, F., Schwanke, U., Sergĳenko, O., Servillat, M., Siejkowski, H., Siqueira, C., Spencer, S., Stamerra, A., Stanič, S., Steppa, C., Stolarczyk, T., Suda, Y., Tavernier, T., Teshima, M., Tibaldo, L., Torres, D. F., Tothill, N., Vacula, M., Vallage, B., Vallania, P., van Eldik, C., Vázquez Acosta, M., Vecchi, M., Ventura, S., Vercellone, S., Viana, A., Vigorito, C. F., Vink, J., Vitale, V., Vodeb, V., Vorobiov, S., Vuillaume, T., Wagner, S. J., Walter, R., White, M., Wierzcholska, A., Will, M., Yamazaki, R., Yang, L., Yoshikoshi, T., Zacharias, M., Zaharĳas, G., Zavrtanik, D., Zavrtanik, M., and Cherenkov Telescope Array Collaboration
Subjects: photon, emission, acceleration, efficiency, Cherenkov Telescope Array, WIMP, diffusion, suppression, sensitivity, Navarro-Frenk-White profile, dark matter, photon, energy, flux, cosmic radiation, spectrum, energy, high, cloud, TeV, spectral, galaxy, nucleus, cosmic radiation
Abstract: A deep survey of the Large Magellanic Cloud at ~0.1-100TeV photon energies with the Cherenkov Telescope Array is planned. We assess the detection prospects based on a model for the emission of the galaxy, comprising the four known TeV emitters, mock populations of sources, and interstellar emission on galactic scales. We also assess the detectability of 30 Doradus and SN 1987A, and the constraints that can be derived on the nature of dark matter. The survey will allow for fine spectral studies of N157B, N132D, LMC P3, and 30 Doradus C, and half a dozen other sources should be revealed, mainly pulsar-powered objects. The remnant from SN 1987A could be detected if it produces cosmic-ray nuclei with a flat power-law spectrum at high energies, or with a steeper index 2.3-2.4 pending a flux increase by a factor >3-4 over ~2015-2035. Large-scale interstellar emission remains mostly out of reach of the survey if its >10GeV spectrum has a soft photon index ~2.7, but degree-scale 0.1-10TeV pion-decay emission could be detected if the cosmic-ray spectrum hardens above >100GeV. The 30 Doradus star-forming region is detectable if acceleration efficiency is on the order of 1-10% of the mechanical luminosity and diffusion is suppressed by two orders of magnitude within
Published: 2023
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2. Sensitivity of the Cherenkov Telescope Array to spectral signatures of hadronic PeVatrons with application to Galactic Supernova Remnants

Author: Acero, F., Acharyya, A., Adam, R., Aguasca-Cabot, A., Agudo, I., Aguirre-Santaella, A., Alfaro, J., Aloisio, R., Crespo, N. Álvarez, Alves Batista, R., Amati, L., Amato, E., Ambrosi, G., Angüner, E. O., Aramo, C., Arcaro, C., Armstrong, T., Asano, K., Ascasibar, Y., Aschersleben, J., Backes, M., Baktash, A., Balazs, C., Balbo, M., Ballet, J., Larriva, A. Baquero, Barbosa Martins, V., de Almeida, U. Barres, Barrio, J. A., Bastieri, D., Baxter, J. R., Becker Tjus, J., Benbow, W., Bernardos-Martín, M. I., Bernete, J., Berti, A., Bertucci, B., Beshley, V., Bhattacharjee, P., Bhattacharyya, S., Biland, A., Bissaldi, E., Biteau, J., Blanch, O., Bordas, P., Bottacini, E., Bregeon, J., Brose, R., Bucciantini, N., Bulgarelli, A., Capasso, M., Dolcetta, R. A. Capuzzo, Caraveo, P., Cardillo, M., Carosi, R., Casanova, S., Cascone, E., Cassol, F., Catalani, F., Cerruti, M., Chadwick, P., Chaty, S., Chen, A., Chernyakova, M., Chiavassa, A., Chudoba, J., Coimbra-Araujo, C., Conforti, V., Contreras, J. L., Costa, A., Costantini, H., Cristofari, P., Crocker, R., D'Amico, G., D'Ammando, F., De Angelis, A., De Caprio, V., de Gouveia Dal Pino, E. M., de Ona Wilhelmi, E., de Souza, V., Delgado, C., della Volpe, D., Depaoli, D., Di Girolamo, T., Di Pierro, F., Di Tria, R., Di Venere, L., Diebold, S., Djuvsland, J. I., Donini, A., Doro, M., Anjos, R. d. C. Dos, Dwarkadas, V. V., Einecke, S., Elsässer, D., Emery, G., Evoli, C., Falceta-Goncalves, D., Fedorova, E., Fegan, S., Ferrand, G., Fiandrini, E., Filipovic, M., Fioretti, V., Fiori, M., Foffano, L., Fontaine, G., Fukami, S., Galanti, G., Galaz, G., Gammaldi, V., Gasbarra, C., Ghalumyan, A., Ghirlanda, G., Giarrusso, M., Giavitto, G., Giglietto, N., Giordano, F., Giroletti, M., Giuliani, A., Giunti, L., Godinovic, N., Coelho, J. Goulart, Gréaux, L., Green, D., Grondin, M.-H., Gueta, O., Gunji, S., Hassan, T., Heller, M., Hernández-Cadena, S., Hinton, J., Hnatyk, B., Hnatyk, R., Hoffmann, D., Hofmann, W., Holder, J., Horan, D., Horvath, P., Hrabovsky, M., Hrupec, D., Inada, T., Incardona, F., Inoue, S., Ishio, K., Jamrozy, M., Janecek, P., Martínez, I. Jiménez, Jin, W., Jung-Richardt, I., Jurysek, J., Kaaret, P., Karas, V., Katz, U., Kerszberg, D., Khélifi, B., Kieda, D. B., Kissmann, R., Kleiner, T., Kluge, G., Kluzniak, W., Knödlseder, J., Kobayashi, Y., Kohri, K., Komin, N., Kornecki, P., Kubo, H., La Palombara, N., Láinez, M., Lamastra, A., Lapington, J., Lemoine-Goumard, M., Lenain, J.-P., Leone, F., Leto, G., Leuschner, F., Lindfors, E., Liodakis, I., Lohse, T., Lombardi, S., Longo, F., López-Coto, R., López-Moya, M., López-Oramas, A., Loporchio, S., Luque-Escamilla, P. L., Macias, O., Mackey, J., Majumdar, P., Mandat, D., Manganaro, M., Manicò, G., Marconi, M., Martí, J., Martínez, G., Martinez, M., Martinez, O., Mello, A. J. T. S., Menchiari, S., Meyer, D. M.-A., Micanovic, S., Miceli, D., Miceli, M., Michalowski, J., Miener, T., Miranda, J. M., Mitchell, A., Mode, B., Moderski, R., Mohrmann, L., Molina, E., Montaruli, T., Morcuende, D., Morlino, G., Morselli, A., Mosè, M., Moulin, E., Mukherjee, R., Munari, K., Murach, T., Nagai, A., Nagataki, S., Nemmen, R., Niemiec, J., Nieto, D., Nievas Rosillo, M., Nikolajuk, M., Nishijima, K., Noda, K., Novosyadlyj, B., Nozaki, S., Ohishi, M., Ohm, S., Ohtani, Y., Okumura, A., Olmi, B., Ong, R. A., Orienti, M., Orito, R., Orlandini, M., Orlando, E., Orlando, S., Ostrowski, M., Oya, I., Pantaleo, F. R., Paredes, J. M., Patricelli, B., Pecimotika, M., Peresano, M., Pérez-Romero, J., Persic, M., Petruk, O., Piano, G., Pietropaolo, E., Pirola, G., Pittori, C., Pohl, Martin, Ponti, G., Prandini, E., Principe, G., Priyadarshi, C., Pueschel, E., Pühlhofer, G., Pumo, M. L., Quirrenbach, A., Rando, R., Razzaque, S., Reichherzer, P., Reimer, A., Reimer, O., Renaud, M., Reposeur, T., Ribó, M., Richtler, T., Rico, J., Rieger, F., Rigoselli, M., Riitano, L., Rizi, V., Roache, E., Romano, P., Romeo, G., Rosado, J., Rowell, G., Rudak, B., Sadeh, I., Safi-Harb, S., Saha, L., Sailer, S., Sánchez-Conde, M., Sarkar, S., Satalecka, K., Saturni, F. G., Scherer, A., Schovánek, P., Schussler, F., Schwanke, U., Scuderi, S., Seglar-Arroyo, M., Sergijenko, O., Servillat, M., Shang, R.-Y., Sharma, P., Siejkowski, H., Sliusar, V., Słowikowska, A., Sol, H., Specovius, A., Spencer, S. T., Spengler, G., Stamerra, A., Stanič, S., Starecki, T., Starling, R., Stolarczyk, T., Pereira, L. A. Stuani, Suda, Y., Suomijarvi, T., Sushch, I., Tajima, H., Tam, P.-H. T., Tanaka, S. J., Tavecchio, F., Testa, V., Tian, W., Tibaldo, L., Torres, D. F., Tothill, N., Vallage, B., Vallania, P., van Eldik, C., van Scherpenberg, J., Vandenbroucke, J., Vazquez Acosta, M., Vecchi, M., Vercellone, S., Verna, G., Viana, A., Vignatti, J., Vitale, V., Vodeb, V., Vorobiov, S., Vuillaume, T., Wagner, S. J., Walter, R., White, M., Wierzcholska, A., Will, M., Williams, D., Yang, L., Yoshida, T., Yoshikoshi, T., Zaharijas, G., Zampieri, L., Zavrtanik, D., Zavrtanik, M., Zhdanov, V. I., Z̆ivec, M., and Cherenkov Telescope Array Collaboration
Subjects: Cherenkov Telescope Array, emission: spectrum, Gamma rays: general, energy spectrum, sensitivity, VHE, observatory, Galactic PeVatrons, cosmic radiation, Methods: data analysis, supernova, spectral, galaxy, hadron, (Stars:) supernovae: general, statistical, Cosmic rays, signature, Methods: statistical
Abstract: The local Cosmic Ray (CR) energy spectrum exhibits a spectral softening at energies around 3 PeV. Sources which are capable of accelerating hadrons to such energies are called hadronic PeVatrons. However, hadronic PeVatrons have not yet been firmly identified within the Galaxy. Several source classes, including Galactic Supernova Remnants (SNRs), have been proposed as PeVatron candidates. The potential to search for hadronic PeVatrons with the Cherenkov Telescope Array (CTA) is assessed. The focus is on the usage of very high energy γ-ray spectral signatures for the identification of PeVatrons. Assuming that SNRs can accelerate CRs up to knee energies, the number of Galactic SNRs which can be identified as PeVatrons with CTA is estimated within a model for the evolution of SNRs. Additionally, the potential of a follow-up observation strategy under moonlight conditions for PeVatron searches is investigated. Statistical methods for the identification of PeVatrons are introduced, and realistic Monte-Carlo simulations of the response of the CTA observatory to the emission spectra from hadronic PeVatrons are performed. Based on simulations of a simplified model for the evolution for SNRs, the detection of a γ-ray signal from in average 9 Galactic PeVatron SNRs is expected to result from the scan of the Galactic plane with CTA after 10 h of exposure. CTA is also shown to have excellent potential to confirm these sources as PeVatrons in deep observations with O(100) hours of exposure per source.
Published: 2023
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3. A lower bound on intergalactic magnetic fields from time variability of 1ES 0229+200 from MAGIC and Fermi/LAT observations

Author: Acciari, V. A., Agudo, I., Aniello, T., Ansoldi, S., Antonelli, L. A., Engels, A. Arbet, Artero, M., Asano, K., Baack, D., Babic, A., Baquero, A., de Almeida, U. Barres, Barrio, J. A., Batkovic, I., González, J. Becerra, Bednarek, W., Bernardini, E., Bernardos, M., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bökenkamp, H., Bonnoli, G., Bošnjak, Ž., Burelli, I., Busetto, G., Carosi, R., Ceribella, G., Cerruti, M., Chai, Y., Chilingarian, A., Cikota, S., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D'Amico, G., D'Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Del Popolo, A., Delfino, M., Delgado, J., Mendez, C. Delgado, Depaoli, D., Di Pierro, F., Di Venere, L., Do Souto Espiñeira, E., Dominis Prester, D., Donini, A., Dorner, D., Doro, M., Elsaesser, D., Fallah Ramazani, V., Fariña, L., Fattorini, A., Font, L., Fruck, C., Fukami, S., Fukazawa, Y., López, R. J. García, Garczarczyk, M., Gasparyan, S., Gaug, M., Giglietto, N., Giordano, F., Gliwny, P., Godinovic, N., Green, J. G., Green, D., Hadasch, D., Hahn, A., Hassan, T., Heckmann, L., Herrera, J., Hrupec, D., Hütten, M., Inada, T., Iotov, R., Ishio, K., Iwamura, Y., Martínez, I. Jiménez, Jormanainen, J., Jouvin, L., Kerszberg, D., Kobayashi, Y., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Linhoff, L., Liodakis, I., Lombardi, S., Longo, F., López-Coto, R., López-Moya, M., López-Oramas, A., Loporchio, S., Lorini, A., de Oliveira Fraga, B. Machado, Maggio, C., Majumdar, P., Makariev, M., Mallamaci, M., Maneva, G., Manganaro, M., Mannheim, K., Mariotti, M., Martínez, M., Aguilar, A. Mas, Mazin, D., Menchiari, S., Mender, S., Micanovic, S., Miceli, D., Miener, T., Miranda, J. M., Mirzoyan, R., Molina, E., Mondal, H. A., Moralejo, A., Morcuende, D., Moreno, V., Moretti, E., Nakamori, T., Nanci, C., Nava, L., Neustroev, V., Nievas Rosillo, M., Nigro, C., Nilsson, K., Nishijima, K., Noda, K., Nozaki, S., Ohtani, Y., Oka, T., Otero-Santos, J., Paiano, S., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Pavletic, L., Peñil, P., Persic, M., Pihet, M., Prada Moroni, P. G., Prandini, E., Priyadarshi, C., Puljak, I., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Sahakyan, N., Saito, T., Sakurai, S., Satalecka, K., Saturni, F. G., Schleicher, B., Schmidt, K., Schmuckermaier, F., Schubert, J. L., Schweizer, T., Sitarek, J., Šnidaric, I., Sobczynska, D., Spolon, A., Stamerra, A., Striškovic, J., Strom, D., Strzys, M., Suda, Y., Suric, T., Takahashi, M., Takeishi, R., Tavecchio, F., Temnikov, P., Terzic, T., Teshima, M., Tosti, L., Truzzi, S., Tutone, A., Ubach, S., van Scherpenberg, J., Vanzo, G., Vazquez Acosta, M., Ventura, S., Verguilov, V., Viale, I., Vigorito, C. F., Vitale, V., Vovk, I., Will, M., Wunderlich, C., Yamamoto, T., Zaric, D., Neronov, A., Semikoz, D., Korochkin, A., MAGIC Collaboration, Département de Physique des Particules (ex SPP) (DPhP), 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, 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 Paris Cité (UPCité), MAGIC, and HEP, INSPIRE
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Cosmology and Nongalactic Astrophysics (astro-ph.CO), galaxies: active, intergalactic magnetic fields, FOS: Physical sciences, Astronomy and Astrophysics, early Universe, magic, fermi, Space and Planetary Science, gamma rays: galaxies, ddc:520, intergalactic medium, Early Universe, Galaxies: active, Gamma rays: galaxies, Intergalactic medium, Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR] Physics [physics]/Astrophysics [astro-ph], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: Astronomy and astrophysics 670, A145 (2023). doi:10.1051/0004-6361/202244126, Context. Extended and delayed emission around distant TeV sources induced by the effects of propagation of γ ray s through the intergalactic medium can be used for the measurement of the intergalactic magnetic field (IGMF).Aims. We search for delayed GeV emission from the hard-spectrum TeV γ-ray emitting blazar 1ES 0229+200, with the goal of detecting or constraining the IGMF-dependent secondary flux generated during the propagation of TeV γ rays through the intergalactic medium.Methods. We analysed the most recent MAGIC observations over a 5 year time span, and complemented them with historic data of the H.E.S.S. and VERITAS telescopes, along with a 12-year-long exposure of the Fermi/LAT telescope. We used them to trace source evolution in the GeV–TeV band over a decade and a half. We used Monte Carlo simulations to predict the delayed secondary γ-ray flux, modulated by the source variability, as revealed by TeV-band observations. We then compared these predictions for various assumed IGMF strengths to all available measurements of the γ-ray flux evolution.Results. We find that the source flux in the energy range above 200 GeV experiences variations around its average on the 14-year time span of observations. No evidence for the flux variability is found in the 1 − 100 GeV energy range accessible to Fermi/LAT. The non-detection of variability due to delayed emission from electromagnetic cascade developing in the intergalactic medium imposes a lower bound of B > 1.8 × 10´$^{−17}$ G for the long-correlation-length IGMF and B > 10$^{−14}$ G for an IGMF of cosmological origin. Though weaker than the one previously derived from the analysis of Fermi/LAT data, this bound is more robust, being based on a conservative intrinsic source spectrum estimate and accounting for the details of source variability in the TeV energy band. We discuss implications of this bound for cosmological magnetic fields that might explain the baryon asymmetry of the Universe., Published by EDP Sciences, Les Ulis
Published: 2023
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4. Studying the nature of the unidentified gamma-ray source HESS J1841−055 with the MAGIC telescopes

Author: A Acciari, V, Ansoldi, S, A Antonelli, L, Arbet , A, Engels, Asano, K, Baack, D, Babić, A, Banerjee, B, Baquero, A, Barresundefined, U, deundefined, Almeida, A Barrio, J, Becerraundefined, J, González, Bednarek, W, Bellizzi, L, Bernardini, E, Bernardos, M, Berti, A, Besenrieder, J, Bhattacharyya, W, Bigongiari, C, Biland, A, Blanch, O, Bonnoli, G, Bošnjak, Ž, Busetto, G, Carosi, R, Ceribella, G, Cerruti, M, Chai, Y, Chilingarian, A, Cikota, S, M Colak, S, Colombo, E, L Contreras, J, Cortina, J, Covino, S, D’Amico, G, D’Elia, V, Daundefined, P, Vela, Dazzi, F, Deundefined, A, Angelis, Deundefined, B, Lotto, Delfino, M, Delgado, J, Delgadoundefined, C, Mendez, Depaoli, D, Diundefined, T, Girolamo, Diundefined, F, Pierro, Diundefined, L, Venere, Doundefined, E, Soutoundefined, Espiñeira, Dominisundefined, D, Prester, Donini, A, Dorner, D, Doro, M, Elsaesser, D, Fallahundefined, V, Ramazani, Fattorini, A, Ferrara, G, Foffano, L, V Fonseca, M, Font, L, Fruck, C, Fukami, S, J Garcíaundefined, R, López, Garczarczyk, M, Gasparyan, S, Gaug, M, Giglietto, N, Giordano, F, Gliwny, P, Godinović, N, Green, D, Hadasch, D, Hahn, A, Heckmann, L, Herrera, J, Hoang, J, Hrupec, D, Hütten, M, Inada, T, Inoue, S, Ishio, K, Iwamura, Y, Jouvin, L, Kajiwara, Y, Karjalainen, M, Kerszberg, D, Kobayashi, Y, Kubo, H, Kushida, J, Lamastra, A, Lelas, D, Leone, F, Lindfors, E, Lombardi, S, Longo, F, López, M, López-Coto, R, López-Oramas, A, Loporchio, S, Machadoundefined, B, deundefined, Oliveiraundefined, Fraga, Maggio, C, Majumdar, P, Makariev, M, Mallamaci, M, Maneva, G, Manganaro, M, Mannheim, K, Maraschi, L, Mariotti, M, Martínez, M, Mazin, D, Mender, S, Mićanović, S, Miceli, D, Miener, T, Minev, M, M Miranda, J, Mirzoyan, R, Molina, E, Moralejo, A, Morcuende, D, Moreno, V, Moretti, E, Munar-Adrover, P, Neustroev, V, Nigro, C, Nilsson, K, Ninci, D, Nishijima, K, Noda, K, Nozaki, S, Ohtani, Y, Oka, T, Otero-Santos, J, Palatiello, M, Paneque, D, Paoletti, R, M Paredes, J, Pavletić, L, Peñil, P, Perennes, C, Persic, M, G Pradaundefined, P, Moroni, Prandini, E, Priyadarshi, C, Puljak, I, Rhode, W, Ribó, M, Rico, J, Righi, C, Rugliancich, A, Saha, L, Sahakyan, N, Saito, T, Sakurai, S, Satalecka, K, Schleicher, B, Schmidt, K, Schweizer, T, Sitarek, J, Šnidarić, I, Sobczynska, D, Spolon, A, Stamerra, A, Strom, D, Strzys, M, Suda, Y, Surić, T, Takahashi, M, Tavecchio, F, Temnikov, P, Terzić, T, Teshima, M, Torres-Albà, N, Tosti, L, Truzzi, S, vanundefined, J, Scherpenberg, Vanzo, G, Vazquezundefined, M, Acosta, Ventura, S, Verguilov, V, F Vigorito, C, Vitale, V, Vovk, I, Will, M, Zarić, D, Ministerio de Economía y Competitividad (España), Agencia Estatal de Investigación (España), Ministerio de Ciencia, Innovación y Universidades (España), Japan Society for the Promotion of Science, German Research Foundation, Acciari, V. A., Ansoldi, S., Antonelli, L. A., Arbet Engels, A., Asano, K., Baack, D., Babic, A., Banerjee, B., Baquero, A., Barres De Almeida, U., Barrio, J. A., Becerra Gonzalez, J., Bednarek, W., Bellizzi, L., Bernardini, E., Bernardos, M., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Bosnjak, Z., Busetto, G., Carosi, R., Ceribella, G., Cerruti, M., Chai, Y., Chilingarian, A., Cikota, S., Colak, S. M., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D'Amico, G., D'Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Delgado Mendez, C., Depaoli, D., Di Girolamo, T., Di Pierro, F., Di Venere, L., Do Souto Espineira, E., Dominis Prester, D., Donini, A., Dorner, D., Doro, M., Elsaesser, D., Fallah Ramazani, V., Fattorini, A., Ferrara, G., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Fukami, S., Garcia Lopez, R. J., Garczarczyk, M., Gasparyan, S., Gaug, M., Giglietto, N., Giordano, F., Gliwny, P., Godinovic, N., Green, D., Hadasch, D., Hahn, A., Heckmann, L., Herrera, J., Hoang, J., Hrupec, D., Hutten, M., Inada, T., Inoue, S., Ishio, K., Iwamura, Y., Jouvin, L., Kajiwara, Y., Karjalainen, M., Kerszberg, D., Kobayashi, Y., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., Lopez, M., Lopez-Coto, R., Lopez-Oramas, A., Loporchio, S., Machado De Oliveira Fraga, B., Maggio, C., Majumdar, P., Makariev, M., Mallamaci, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martinez, M., Mazin, D., Mender, S., Micanovic, S., Miceli, D., Miener, T., Minev, M., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Morcuende, D., Moreno, V., Moretti, E., Munar-Adrover, P., Neustroev, V., Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nozaki, S., Ohtani, Y., Oka, T., Otero-Santos, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Pavletic, L., Penil, P., Perennes, C., Persic, M., Prada Moroni, P. G., Prandini, E., Priyadarshi, C., Puljak, I., Rhode, W., Ribo, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Sahakyan, N., Saito, T., Sakurai, S., Satalecka, K., Schleicher, B., Schmidt, K., Schweizer, T., Sitarek, J., Snidaric, I., Sobczynska, D., Spolon, A., Stamerra, A., Strom, D., Strzys, M., Suda, Y., Suric, T., Takahashi, M., Tavecchio, F., Temnikov, P., Terzic, T., Teshima, M., Torres-Alba, N., Tosti, L., Truzzi, S., Van Scherpenberg, J., Vanzo, G., Vazquez Acosta, M., Ventura, S., Verguilov, V., Vigorito, C. F., Vitale, V., Vovk, I., Will, M., and Zaric, D.
Subjects: gamma-rays: stars, ISM: individual objects: HESS J1841−055, ISM: supernova remnants, radiation mechanisms: non-thermal, pulsars: general, Hadron, pi, Astrophysics, individual objects: HESS J1841−055 [ISM], 4/3, 01 natural sciences, general [pulsars], HESS, cloud, MAGIC (telescope), 010303 astronomy & astrophysics, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, astro-ph.HE, supernova remnants [ISM], ISM: individual objects: HESS J1841-055, Astrophysics - High Energy Astrophysical Phenomena, Gamma ray, Bremsstrahlung, model: hadronic, non-thermal [radiation mechanisms], Supernova remnant [ISM], gamma ray: emission, curvature, Spectral energy distribution, Electrónica, Electricidad, ISM: Individual objects: HESS J1841-055, Astrophysics::High Energy Astrophysical Phenomena, Star [gamma-rays], energy spectrum, FOS: Physical sciences, Curvature, bremsstrahlung, GeneralLiterature_MISCELLANEOUS, GLAST, stars [gamma-rays], energy dependence, gamma-rays: Stars, ISM: Supernova remnants, pulsars: General, radiation mechanisms: Non-thermal, Pion, emission [gamma ray], 0103 physical sciences, 010308 nuclear & particles physics, Molecular cloud, ComputingMilieux_PERSONALCOMPUTING, Astronomy and Astrophysics, MAGIC, Individual objects: HESS J1841-055 [ISM], Space and Planetary Science, ddc:520, spectral, High Energy Physics::Experiment, hadronic [model]
Abstract: MAGIC Collaboration: et al., We investigate the physical nature and origin of the gamma-ray emission from the extended source HESS J1841−055 observed at TeV and GeV energies. We observed HESS J1841−055 at TeV energies for a total effective time of 43 h with the MAGIC telescopes, in 2012 and 2013. Additionally, we analysed the GeV counterpart making use of about 10 yr of Fermi-LAT data. Using both Fermi-LAT and MAGIC, we study both the spectral and energy-dependent morphology of the source for almost four decades of energy. The origin of the gamma-ray emission from this region is investigated using multiwaveband information on sources present in this region, suggested to be associated with this unidentified gamma-ray source. We find that the extended emission at GeV–TeV energies is best described by more than one source model. We also perform the first energy-dependent analysis of the HESS J1841−055 region at GeV–TeV. We find that the emission at lower energies comes from a diffuse or extended component, while the major contribution of gamma rays above 1 TeV arises from the southern part of the source. Moreover, we find that a significant curvature is present in the combined observed spectrum of MAGIC and Fermi-LAT. The first multiwavelength spectral energy distribution of this unidentified source shows that the emission at GeV–TeV energies can be well explained with both leptonic and hadronic models. For the leptonic scenario, bremsstrahlung is the dominant emission compared to inverse Compton. On the other hand, for the hadronic model, gamma-ray resulting from the decay of neutral pions (π0) can explain the observed spectrum. The presence of dense molecular clouds overlapping with HESS J1841−055 makes both bremsstrahlung and π0-decay processes the dominant emission mechanisms for the source., The financial support by the German BMBF and MPG; the Italian INFN and INAF; the Swiss National Fund SNF; the ERDF under the Spanish MINECO (FPA2015-69818-P, FPA2012-36668, FPA2015-68378-P, FPA2015-69210-C6-2-R, FPA2015-69210-C6-4-R, FPA2015-69210-C6-6-R, AYA2015-71042-P, AYA2016-76012-C3-1-P, ESP2015-71662-C2-2-P, and FPA2017-90566-REDC); the Indian Department of Atomic Energy; and the Japanese JSPS and MEXT; the Bulgarian Ministry of Education and Science, National RI Roadmap Project DO1-153/28.08.2018 and the Academy of Finland grant nr. 320045 is gratefully acknowledged. This work was also supported by the Spanish Centro de Excelencia ‘Severo Ochoa’ SEV-2012-0234 and SEV-2015-0548, and Unidad de Excelencia ‘Maria de Maeztu’ MDM-2014-0369, 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 National Research Centre grant UMO-2016/22/M/ST9/00382 and by the Brazilian MCTIC, CNPq and FAPERJ.
Published: 2020
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5. New Hard-TeV Extreme Blazars Detected with the MAGIC Telescopes

Author: Acciari, V. A., Ansoldi, S., Antonelli, L. A., Engels, A. Arbet, Asano, K., Baack, D., Babić, A., Banerjee, B., De Almeida, U. Barres, Barrio, J. A., González, J. Becerra, Bednarek, W., Bellizzi, L., Bernardini, E., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Bošnjak, Ž., Busetto, G., Carosi, R., Ceribella, G., Cerruti, M., Chai, Y., Chilingaryan, A., Cikota, S., Colak, S. M., Colin, U., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D’Elia, V., Vela, P. Da, Dazzi, F., Angelis, A. De, Lotto, B. De, Delfino, M., Delgado, J., Depaoli, D., Pierro, F. Di, Venere, L. Di, Souto Espiñeira, E. Do, Prester, D. Dominis, Donini, A., Dorner, D., Doro, M., Elsaesser, D., Ramazani, V. Fallah, Fattorini, A., Ferrara, G., Fidalgo, D., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Fukami, S., López, R. J. García, Garczarczyk, M., Gasparyan, S., Gaug, M., Giglietto, N., Giordano, F., Godinović, N., Green, D., Guberman, D., Hadasch, D., Hahn, A., Herrera, J., Hoang, J., Hrupec, D., Hütten, M., Inada, T., Inoue, S., Ishio, K., Iwamura, Y., Jouvin, L., Kerszberg, D., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., López, M., López-Coto, R., López-Oramas, A., Loporchio, S., De Oliveira Fraga, B. Machado, Maggio, C., Majumdar, P., Makariev, M., Mallamaci, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Mazin, D., Mićanović, S., Miceli, D., Minev, M., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Morcuende, D., Moreno, V., Moretti, E., Munar-Adrover, P., Neustroev, V., Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Nozaki, S., Paiano, S., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Peñil, P., Peresano, M., Persic, M., Moroni, P. G. Prada, Prandini, E., Puljak, I., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Sahakyan, N., Saito, T., Sakurai, S., Satalecka, K., Schmidt, K., Schweizer, T., Sitarek, J., Šnidarić, I., Sobczynska, D., Somero, A., Stamerra, A., Strom, D., Strzys, M., Suda, Y., Surić, T., Takahashi, M., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Torres-Albà, N., Tosti, L., Vagelli, V., Scherpenberg, J. Van, Vanzo, G., Acosta, M. Vazquez, Vigorito, C. F., Vitale, V., Vovk, I., Will, M., Zarić, D., Arcaro, C., Carosi, A., D’Ammando, F., Tombesi, F., Lohfink, A., and Fallah Ramazani, V.
Subjects: X-ray, gamma ray: emission, gamma ray: VHE, quality, synchrotron, spectral, magnetization, MAGIC, proton synchrotron, model: leptonic, blazar
Abstract: The astrophysical journal / Supplement series Supplement series [...] 247(1), 16 - (2020). doi:10.3847/1538-4365/ab5b98, Extreme high-frequency-peaked BL Lac objects (EHBLs) are blazars that exhibit extremely energetic synchrotron emission. They also feature nonthermal gamma-ray emission whose peak lies in the very high-energy (VHE, E > 100 GeV) range, and in some sources exceeds 1 TeV: this is the case for hard-TeV EHBLs such as 1ES 0229+200. With the aim of increasing the EHBL population, 10 targets were observed with the MAGIC telescopes from 2010 to 2017, for a total of 265 hr of good-quality data. The data were complemented by coordinated Swift observations. The X-ray data analysis confirms that all but two sources are EHBLs. The sources show only a modest variability and a harder-when-brighter behavior, typical for this class of objects. At VHE gamma-rays, three new sources were detected and a hint of a signal was found for another new source. In each case, the intrinsic spectrum is compatible with the hypothesis of a hard-TeV nature of these EHBLs. The broadband spectral energy distributions (SEDs) of all sources are built and modeled in the framework of a single-zone, purely leptonic model. The VHE gamma-ray-detected sources were also interpreted with a spine–layer model and a proton synchrotron model. The three models provide a good description of the SEDs. However, the resulting parameters differ substantially in the three scenarios, in particular the magnetization parameter. This work presents the first mini catalog of VHE gamma-ray and multiwavelength observations of EHBLs., Published by Univ. of Chicago Press11033, Chicago, Ill. [u.a.]
Published: 2020
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6. Constraints on Gamma-Ray and Neutrino Emission from NGC 1068 with the MAGIC Telescopes

Author: Acciari, V. A., Ansoldi, S., Antonelli, L. A., Arbet Engels, A., Baack, D., Babić, A., Banerjee, B., Barres De Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bellizzi, L., Bernardini, E., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Bošnjak, Ž., Busetto, G., Carosi, R., Ceribella, G., Chai, Y., Chilingaryan, A., Cikota, S., Colak, S. M., Colin, U., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D'Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Depaoli, D., Di Pierro, F., Di Venere, L., Do Souto Espiñeira, E., Dominis Prester, D., Donini, A., Dorner, D., Doro, M., Elsaesser, D., Fallah Ramazani, V., Fattorini, A., Ferrara, G., Fidalgo, D., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Fukami, S., García López, R. J., Garczarczyk, M., Gasparyan, S., Gaug, M., Giglietto, N., Giordano, F., Godinović, N., Green, D., Guberman, D., Hadasch, D., Hahn, A., Herrera, J., Hoang, J., Hrupec, D., Hütten, M., Inada, T., Inoue, S., Ishio, K., Iwamura, Y., Jouvin, L., Kerszberg, D., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., López, M., López-Coto, R., López-Oramas, A., Loporchio, S., Machado De Oliveira Fraga, B., Maggio, C., Majumdar, P., Makariev, M., Mallamaci, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Mazin, D., Mićanović, S., Miceli, D., Minev, M., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Morcuende, D., Moreno, V., Moretti, E., Munar-Adrover, P., Neustroev, V., Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Nozaki, S., Paiano, S., Palacio, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Peñil, P., Peresano, M., Persic, M., Prada Moroni, P. G., Prandini, E., Puljak, I., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Sahakyan, N., Saito, T., Sakurai, S., Satalecka, K., Schmidt, K., Schweizer, T., Sitarek, J., Šnidarić, I., Sobczynska, D., Somero, A., Stamerra, A., Strom, D., Strzys, M., Suda, Y., Surić, T., Takahashi, M., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Torres-Albà, N., Tosti, L., Vagelli, V., Van Scherpenberg, J., Vanzo, G., Vazquez Acosta, M., Vigorito, C. F., Vitale, V., Vovk, I., Will, M., Zarić, D., Fiore, F., Feruglio, C., and Rephaeli, Y.
Subjects: accelerator, neutrino: background, star: formation, MAGIC, GLAST, VHE, IceCube, gamma ray: emission, p: cosmic radiation, slope, spectral, gamma ray: flux, galaxy, AGN
Abstract: The astrophysical journal / 1 883(2), 1 - 11 (2019). doi:10.3847/1538-4357/ab3a51, Starburst galaxies and star-forming active galactic nuclei are among the candidate sources thought to contribute appreciably to the extragalactic gamma-ray and neutrino backgrounds. NGC 1068 is the brightest of the star-forming galaxies found to emit gamma-rays from 0.1 to 50 GeV. Precise measurements of the high-energy spectrum are crucial to study the particle accelerators and probe the dominant emission mechanisms. We have carried out 125 hr of observations of NGC 1068 with the MAGIC telescopes in order to search for gamma-ray emission in the very-high-energy band. We did not detect significant gamma-ray emission, and set upper limits at the 95% confidence level to the gamma-ray flux above 200 GeV f < 5.1 × 10−13 cm−2 s−1. This limit improves previous constraints by about an order of magnitude and allows us to put tight constraints on the theoretical models for the gamma-ray emission. By combining the MAGIC observations with the Fermi-LAT spectrum we limit the parameter space (spectral slope, maximum energy) of the cosmic ray protons predicted by hadronuclear models for the gamma-ray emission, while we find that a model postulating leptonic emission from a semi-relativistic jet is fully consistent with the limits. We provide predictions for IceCube detection of the neutrino signal foreseen in the hadronic scenario. We predict a maximal IceCube neutrino event rate of 0.07 yr−1., Published by Institute of Physics Publ., London
Published: 2019
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7. A Fast Very High Energy $\gamma$-ray Flare from BL Lacertae during a Period of Multiwavelength activity in June 2015

Author: Acciari, V. A., Ansoldi, S., Antonelli, L. A., Engels, A. Arbet, Baack, D., Babić, A., Banerjee, B., Bangale, P., Barres De Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bernardini, E., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Carosi, R., Ceribella, G., Cikota, S., Colak, S. M., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D'Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Di Pierro, F., Espiñera, E. Souto, Domínguez, A., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Elsaesser, D., Fallah Ramazani, V., Fattorini, A., Fernández-Barral, A., Ferrara, G., Fidalgo, D., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., Gallozzi, S., López, R. J. García, Garczarczyk, M., Gaug, M., Giammaria, P., Godinović, N., Guberman, D., Hadasch, D., Hahn, A., Hassan, T., Herrera, J., Hoang, J., Hrupec, D., Inoue, S., Ishio, K., Iwamura, Y., Kubo, H., Kushida, J., Kuveždić, D., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., López, M., López-Oramas, A., Maggio, C., Majumdar, P., Makariev, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Masuda, S., Mazin, D., Minev, M., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Moreno, V., Moretti, E., Munar-Adrover, P., Neustroev, V., Niedzwiecki, A., Nievas Rosillo, M., Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Nöthe, M., Paiano, S., Palacio, J., Paneque, D., Paoletti, R., Paredes, J. M., Pedaletti, G., Peñil, P., Peresano, M., Persic, M., Prada Moroni, P. G., Prandini, E., Puljak, I., Garcia, J. R., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Saito, T., Satalecka, K., Schweizer, T., Sitarek, J., Šnidarić, I., Sobczynska, D., Somero, A., Stamerra, A., Strzys, M., Surić, T., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Torres-Albà, N., Tsujimoto, S., Van Scherpenberg, J., Vanzo, G., Vazquez Acosta, M., Vovk, I., Will, M., Zarić, D., D'Ammando, F., Hada, K., Jorstad, S., Marscher, A. P., Mobeen, M. Z., Larionov, V. M., Borman, G. A., Grishina, T. S., Kopatskaya, E. N., Morozova, D. A., Nikiforova, A. A., Lähteenmäki, A., Tornikoski, M., Agudo, I., and MAGIC Collaboration
Subjects: energy: high, radio wave, interaction: model, photon, tension, 4/3, MAGIC, rotation, emission: model, X-ray, flux, gamma ray: VHE, star, jet, spectral, polarization: optical, AGN
Abstract: Astronomy and astrophysics 623, A175 - (2019). doi:10.1051/0004-6361/201834010, The mechanisms producing fast variability of the γ-ray emission in active galactic nuclei (AGNs) are under debate. The MAGIC telescopes detected a fast, very-high-energy (VHE, E > 100 GeV) γ-ray flare from BL Lacertae on 2015 June 15. The flare had a maximum flux of (1.5 ± 0.3) × 10−10 photons cm−2 s−1 and halving time of 26 ± 8 min. The MAGIC observations were triggered by a high state in the optical and high-energy (HE, E > 100 MeV) γ-ray bands. In this paper we present the MAGIC VHE γ-ray data together with multi-wavelength data from radio, optical, X-rays, and HE γ rays from 2015 May 1 to July 31. Well-sampled multi-wavelength data allow us to study the variability in detail and compare it to the other epochs when fast, VHE γ-ray flares have been detected from this source. Interestingly, we find that the behaviour in radio, optical, X-rays, and HE γ-rays is very similar to two other observed VHE γ-ray flares. In particular, also during this flare there was an indication of rotation of the optical polarization angle and of activity at the 43 GHz core. These repeating patterns indicate a connection between the three events. We also test modelling of the spectral energy distribution based on constraints from the light curves and VLBA observations, with two different geometrical setups of two-zone inverse Compton models. In addition we model the γ-ray data with the star-jet interaction model. We find that all of the tested emission models are compatible with the fast VHE γ-ray flare, but all have some tension with the multi-wavelength observations.Key words: BL Lacertae objects: individual: BL Lacertae / gamma rays: galaxies⋆ MAGIC and multiwavelength data are only 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/623/A175⋆⋆ Corresponding authors: E. Lindfors, e-mail: elilin@utu.fi; M. Vazquez Acosta, e-mail: monicava@iac.es; S. Tsujimoto, e-mail: shimpei.tsujimoto@gmail.com, Published by EDP Sciences, Les Ulis
Published: 2019
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8. Detection of persistent VHE gamma-ray emission from PKS 1510-089 by the MAGIC telescopes during low states between 2012 and 2017

Author: Acciari, V. A., Ansoldi, S., Antonelli, L. A., Engels, A. Arbet, Arcaro, C., Baack, D., Babić, A., Banerjee, B., Bangale, P., Barres De Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bernardini, E., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Carosi, R., Ceribella, G., Chatterjee, A., Colak, S. M., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Cumani, P., D'Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Di Pierro, F., Domínguez, A., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Elsaesser, D., Fallah Ramazani, V., Fattorini, A., Fernández-Barral, A., Ferrara, G., Fidalgo, D., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Gallozzi, S., López, R. J. García, Garczarczyk, M., Gaug, M., Giammaria, P., Godinović, N., Guberman, D., Hadasch, D., Hahn, A., Hassan, T., Herrera, J., Hoang, J., Hrupec, D., Inoue, S., Ishio, K., Iwamura, Y., Kubo, H., Kushida, J., Kuveždić, D., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., López, M., López-Oramas, A., Maggio, C., Majumdar, P., Makariev, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Masuda, S., Mazin, D., Minev, M., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Moreno, V., Moretti, E., Neustroev, V., Niedzwiecki, A., Nievas Rosillo, M., Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Paiano, S., Palacio, J., Paneque, D., Paoletti, R., Paredes, J. M., Pedaletti, G., Peñil, P., Peresano, M., Persic, M., Prada Moroni, P. G., Prandini, E., Puljak, I., Garcia, J. R., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Saito, T., Satalecka, K., Schweizer, T., Sitarek, J., Šnidarić, I., Sobczynska, D., Somero, A., Stamerra, A., Strzys, M., Surić, T., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Torres-Albà, N., Tsujimoto, S., Vanzo, G., Vazquez Acosta, M., Vovk, I., Ward, J. E., Will, M., Zarić, D., Raiteri, C. M., Sandrinelli, A., Hovatta, T., and Kiehlmann, S.
Abstract: Astronomy and astrophysics 619, A159 (2018). doi:10.1051/0004-6361/201833618, Context. PKS 1510–089 is a flat spectrum radio quasar strongly variable in the optical and GeV range. To date, very high-energy (VHE, > 100 GeV) emission has been observed from this source either during long high states of optical and GeV activity or during short flares.Aims. We search for low-state VHE gamma-ray emission from PKS 1510–089. We characterize and model the source in a broadband context, which would provide a baseline over which high states and flares could be better understood.Methods. PKS 1510–089 has been monitored by the MAGIC telescopes since 2012. We use daily binned Fermi-LAT flux measurements of PKS 1510–089 to characterize the GeV emission and select the observation periods of MAGIC during low state of activity. For the selected times we compute the average radio, IR, optical, UV, X-ray, and gamma-ray emission to construct a low-state spectral energy distribution of the source. The broadband emission is modeled within an external Compton scenario with a stationary emission region through which plasma and magnetic fields are flowing. We also perform the emission-model-independent calculations of the maximum absorption in the broad line region (BLR) using two different models.Results. The MAGIC telescopes collected 75 hr of data during times when the Fermi-LAT flux measured above 1 GeV was below 3 × 10$^{−8}$ cm$^{−2}$ s$^{−1}$, which is the threshold adopted for the definition of a low gamma-ray activity state. The data show a strongly significant (9.5σ) VHE gamma-ray emission at the level of (4.27 ± 0.61$_{stat}$) × 10$^{−12}$ cm$^{−2}$ s$^{−1}$ above 150 GeV, a factor of 80 lower than the highest flare observed so far from this object. Despite the lower flux, the spectral shape is consistent with earlier detections in the VHE band. The broadband emission is compatible with the external Compton scenario assuming a large emission region located beyond the BLR. For the first time the gamma-ray data allow us to place a limit on the location of the emission region during a low gamma-ray state of a FSRQ. For the used model of the BLR, the 95% confidence level on the location of the emission region allows us to place it at a distance > 74% of the outer radius of the BLR., Published by EDP Sciences, Les Ulis
Published: 2018
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9. The broad-band properties of the intermediate synchrotron peaked BL Lac S2 0109+22 from radio to VHE gamma rays

Author: Ansoldi, S., Antonelli, L. A., Arcaro, C., Baack, D., Babić, A., Banerjee, B., Bangale, P., Barres De Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bernardini, E., Berse, R Ch, Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Carosi, R., Ceribella, G., Chatterjee, A., Colak, S. M., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Cumani, P., D’Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Di Pierro, F., Domínguez, A., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Elsaesser, D., Fallah Ramazani, V., Fattorini, A., Fernández-Barral, A., Ferrara, G., Fidalgo, D., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Gallozzi, S., García López, R. J., Garczarczyk, M., Gaug, M., Giammaria, P., Godinović, N., Guberman, D., Hadasch, D., Hahn, A., Hassan, T., Hayashida, M., Herrera, J., Hoang, J., Hrupec, D., Inoue, S., Ishio, K., Iwamura, Y., Konno, Y., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., López, M., Maggio, C., Majumdar, P., Makariev, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Masuda, S., Mazin, D., Mielke, K., Minev, M., Miranda, J. M., Mirzoyan, R., Moralejo, A., Moreno, V., Moretti, E., Neustroev, V., Niedzwiecki, A., Nievas Rosillo, M., Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Paiano, S., Palacio, J., Paneque, D., Paoletti, R., Paredes, J. M., Pedaletti, G., Peñil, P., Peresano, M., Persic, M., Pfrang, K., Prada Moroni, P. G., Prandini, E., Puljak, I., Garcia, J. R., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Saito, T., Satalecka, K., Schweizer, T., Sitarek, J., Šnidarić, I., Sobczynska, D., Stamerra, A., Strzys, M., Surić, T., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Torres-Albà, N., Tsujimoto, S., Vanzo, G., Vazquez Acosta, M., Vovk, I., Ward, J. E., Will, M., Zarić, D., Ciprini, S., Desiante, R., Barcewicz, S., Hovatta, T., Jormanainen, J., Takalo, L., Reinthal, R., Mankuzhiyil, N., Wierda, F., Lähteenmäki, A., Tammi, J., Tornikoski, M., Vera, R. J. C., Kiehlmann, S., Max-Moerbeck, W., and Readhead, A. C. S.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Cosmology and Extragalactic Astrophysics
Abstract: The MAGIC telescopes observed S2 0109+22 in 2015 July during its flaring activity in high energy gamma rays observed by Fermi-LAT. We analyse the MAGIC data to characterise the very high energy (VHE) gamma-ray emission of S2 0109+22, which belongs to the subclass of intermediate synchrotron peak (ISP) BL Lac objects. We study the multi-frequency emission in order to investigate the source classification. Finally, we compare the source long-term behaviour to other VHE gamma-ray emitting (TeV) blazars. We performed a temporal and spectral analysis of the data centred around the MAGIC interval of observation (MJD 57225-57231). Long-term radio and optical data have also been investigated using the discrete correlation function. The redshift of the source is estimated through optical host-galaxy imaging and also using the amount of VHE gamma-ray absorption. The quasi-simultaneous multi-frequency spectral energy distribution (SED) is modelled with the conventional one-zone synchrotron self-Compton (SSC) model. MAGIC observations resulted in the detection of the source at a significance level of $5.3\,\sigma$. The VHE gamma-ray emission of S2 0109+22 is variable on a daily time scale. VHE gamma-ray luminosity of the source is lower than the average of TeV BL Lacs. The optical polarization, and long-term optical/radio behaviour of the source are different from the general population of TeV blazars. All these findings agree with the classification of the source as an ISP BL Lac object. We estimate the source redshift as $z = 0.36 \pm 0.07$. The SSC parameters describing the SED are rather typical for blazars.
Published: 2018
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10. Erratum: A cut-off in the TeV gamma-ray spectrum of the SNR Cassiopeia A

Author: Ahnen, MAGIC Collaboration: M L, Ansoldi, S., Antonelli, L. A., Arcaro, C., Babić, A., Banerjee, B., Bangale, P., De Almeida, U Barres, Barrio, J. A., González, J Becerra, Bednarek, W., Bernardini, E., Berti, A., Bhattacharyya, W., Biasuzzi, B., Biland, A., Blanch, O., Bonnefoy, S., Bonnoli, G., Carosi, R., Carosi, A., Chatterjee, A., Colak, M., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Cumani, P., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., De Oña Wilhelmi, E., Pierro, F Di, Doert, M., Domínguez, A., Prester, D Dominis, Dorner, D., Doro, M., Einecke, S., Glawion, D Eisenacher, Elsaesser, D., Engelkemeier, M., Ramazani, V Fallah, Fernández-Barral, A., Fidalgo, D., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., López, R J García, Garczarczyk, M., Gaug, M., Giammaria, P., Godinović, N., Gora, D., Guberman, D., Hadasch, D., Hahn, A., Hassan, T., Hayashida, M., Herrera, J., Hose, J., Hrupec, D., Inada, T., Ishio, K., Konno, Y., Kubo, H., Kushida, J., Kuveždić, D., Lelas, D., Lindfors, E., Lombardi, S., Longo, F., López, M., Maggio, C., Majumdar, P., Makariev, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Mazin, D., Menzel, U., Minev, M., Mirzoyan, R., Moralejo, A., Moreno, V., Moretti, E., Neustroev, V., Niedzwiecki, A., Rosillo, M Nievas, Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Paiano, S., Palacio, J., Paneque, D., Paoletti, R., Paredes, J. M., Pedaletti, G., Peresano, M., Perri, L., Persic, M., Moroni, P G Prada, Prandini, E., Puljak, I., Garcia, J. R., Reichardt, I., Rhode, W., Ribó, M., Rico, J., Righi, C., Saito, T., Satalecka, K., Schroeder, S., Schweizer, T., Shore, S. N., Sitarek, J., Šnidarić, I., Sobczynska, D., Stamerra, A., Strzys, M., Surić, T., Takalo, L., Tavecchio, F., Temnikov, P., Terzić, T., Tescaro, D., Teshima, M., Torres, D. F., Torres-Albà, N., Treves, A., Vanzo, G., Acosta, M Vazquez, Vovk, I., Ward, J. E., Will, M., and Zarić, D.
Abstract: Monthly notices of the Royal Astronomical Society 476(3), 2874 - 2875 (2018). doi:10.1093/mnras/sty382, Published by Oxford Univ. Press, Oxford
Published: 2018
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11. Detection of the blazar S4 0954+65 at very-high-energy with the MAGIC telescopes during an exceptionally high optical state

Author: Ahnen, M. L., Ansoldi, S., Antonelli, L. A., Arcaro, C., Baack, D., Babić, A., Banerjee, B., Bangale, P., Barres De Almeida, U., Barrio, J. A., Bednarek, W., Bernardini, E., Berse, R. Ch., Berti, A., Bhattacharyya, W., Biland, A., Blanch, O., Bonnoli, G., Carosi, R., Carosi, A., Ceribella, G., Chatterjee, A., Colak, S. M., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Cumani, P., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Di Pierro, F., Domínguez, A., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Elsaesser, D., Fallah Ramazani, V., Fernández-Barral, A., Fidalgo, D., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., García López, R. J., Garczarczyk, M., Gaug, M., Giammaria, P., Godinović, N., Gora, D., Guberman, D., Hadasch, D., Hahn, A., Hassan, T., Hayashida, M., Herrera, J., Hose, J., Hrupec, D., Ishio, K., Konno, Y., Kubo, H., Kushida, J., Kuveždić, D., Lelas, D., Lindfors, E., Lombardi, S., Longo, F., López, M., Maggio, C., Majumdar, P., Makariev, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Masuda, S., Mazin, D., Mielke, K., Minev, M., Miranda, J. M., Mirzoyan, R., Moralejo, A., Moreno, V., Moretti, E., Nagayoshi, T., Neustroev, V., Niedzwiecki, A., Nievas Rosillo, M., Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Paiano, S., Palacio, J., Paneque, D., Paoletti, R., Paredes, J. M., Pedaletti, Giovanna, Peresano, M., Persic, M., Prada Moroni, P. G., Prandini, E., Puljak, I., Garcia, J. R., Reichardt, I., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saito, T., Satalecka, K., Schweizer, T., Sitarek, J., Šnidarić, I., Sobczynska, D., Stamerra, A., Strzys, M., Surić, T., Takahashi, M., Takalo, L., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Torres-Albà, N., Treves, A., Tsujimoto, S., Vanzo, G., Vazquez Acosta, M., Vovk, I., Ward, J. E., Will, M., Zarić, D., Becerra Gonzalez, Josefa, Tanaka, Y., Ojha, R., Finke, J., Lähteenmäki, A., Järvelä, E., Tornikoski, M., Ramakrishnan, V., Hovatta, T., Jorstad, S. G., Marscher, A. P., Larionov, V. M., Borman, G. A., Grishina, T. S., Kopatskaya, E. N., Larionova, L. V., Morozova, D. A., Savchenko, S. S., Troitskaya, Yu. V., Troitsky, I. S., Vasilyev, A. A., Agudo, I., Molina, S. N., Casadio, C., Gurwell, M., Carnerero, M. I., Protasio, C., and Acosta Pulido, J. A.
Abstract: Astronomy and astrophysics 617, A30 (2018). doi:10.1051/0004-6361/201832624, ims.The very high energy (VHE&100GeV)γ-ray MAGIC observations of the blazar S4 0954+65, were triggered by anexceptionally high flux state of emission in the optical. This blazar has a disputed redshift ofz= 0.368 orz>0.45 and an uncertainclassification among blazar subclasses. The exceptional source state described here makes for an excellent opportunity to understandphysical processes in the jet of S4 0954+65 and thus contribute to its classification.Methods.We investigated the multiwavelength (MWL) light curve and spectral energy distribution (SED) of the S4 0954+65 blazarduring an enhanced state in February 2015 and have put it in context with possible emission scenarios. We collected photometric datain radio, optical, X-ray, andγ-ray. We studied both the optical polarization and the inner parsec-scale jet behavior with 43 GHz data.Results.Observations with the MAGIC telescopes led to the first detection of S4 0954+65 at VHE. Simultaneous data withFermi-LAT at high energyγ-ray(HE, 100 MeV, Published by EDP Sciences, Les Ulis
Published: 2018
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12. The extreme HBL behaviour of Markarian 501 during 2012

Author: Ahnen, M. L., Ansoldi, S., Antonelli, L. A., Arcaro, C., Babić, A., Banerjee, B., Bangale, P., Barres De Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bernardini, E., Berti, A., Bhattacharyya, W., Blanch, O., Bonnoli, G., Carosi, R., Carosi, A., Chatterjee, A., Colak, S. M., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Cumani, P., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Di Pierro, F., Doert, M., Domínguez, A., Dominis Prester, D., Doro, M., Eisenacher Glawion, D., Engelkemeier, M., Fallah Ramazani, V., Fernández-Barral, A., Fidalgo, D., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., García López, R. J., Garczarczyk, M., Gaug, M., Giammaria, P., Godinović, N., Gora, D., Guberman, D., Hadasch, D., Hahn, A., Hassan, T., Hayashida, M., Herrera, J., Hose, J., Hrupec, D., Ishio, K., Konno, Y., Kubo, H., Kushida, J., Kuveždić, D., Lelas, D., Lindfors, E., Lombardi, S., Longo, F., López, M., Maggio, C., Majumdar, P., Makariev, M., Maneva, G., Manganaro, M., Maraschi, L., Mariotti, M., Martínez, M., Mazin, D., Menzel, U., Minev, M., Miranda, J. M., Mirzoyan, R., Moralejo, A., Moreno, V., Moretti, E., Nagayoshi, T., Neustroev, V., Niedzwiecki, A., Nievas Rosillo, M., Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Paiano, S., Palacio, J., Paneque, D., Paoletti, R., Paredes, J. M., Pedaletti, Giovanna, Peresano, M., Perri, L., Persic$, Prada Moroni, P. G., Prandini, E., Puljak, I., Garcia, J. R., Reichardt, I., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saito, T., Satalecka, K., Schroeder, S., Schweizer, T., Shore, S. N., Sitarek, J., Šnidarić, I., Sobczynska, D., Stamerra, A., Strzys, M., Surić, T., Takalo, L., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Torres-Albà, N., Treves, A., Tsujimoto, S., Vanzo, G., Vazquez Acosta, M., Vovk, I., Ward, J. E., Will, M., Zarić, D., Arbet-Engels, A., Baack, D., Balbo, M., Biland, A., Blank, M., Bretz, T., Bruegge, K., Bulinski, M., Buss, J., Dmytriiev, A., Dorner, D., Einecke, S., Elsaesser, D., Herbst, T., Hildebrand, D., Kortmann, L., Linhoff, L., Mahlke, M., Mannheim, K., Mueller, S. A., Neise, D., Neronov, A., Noethe, M., Oberkirch, J., Paravac, A., Rhode, W., Schleicher, B., Schulz, F., Sedlaczek, K., Shukla, A., Sliusar, V., Walter, R., Archer, A., Benbow, W., Bird, R., Brose, R., Buckley, J. H., Bugaev, V., Christiansen, J. L., Cui, W., Daniel, M. K., Falcone, A., Feng, Q., Finley, J. P., Gillanders, G. H., Gueta, O., Hanna, D., Hervet, O., Holder, J., Hughes, G., Huetten, Moritz, Humensky, T. B., Johnson, C. A., Kaaret, P., Kar, P., Kelley-Hoskins, N., Kertzman, M., Kieda, D., Krause, Maria, Krennrich, F., Kumar, S., Lang, M. J., Lin, T. T. Y., Maier, Gernot, McArthur, S., Moriarty, P., Mukherjee, R., O'Brien, S., Ong, R. A., Otte, A. N., Park, N., Petrashyk, A., Pichel, A., Pohl, Martin, Quinn, J., Ragan, K., Reynolds, P. T., Richards, G. T., Roache, E., Rovero, A. C., Rulten, C., Sadeh, I., Santander, M., Sembroski, G. H., Shahinyan, K., Sushch, I., Tyler, J., Wakely, S. P., Weinstein, A., Wells, R. M., Wilcox, P., Wilhel, A., Williams, D. A., J Williamson, T., Zitzer, B., Perri, M., Verrecchia, F., Leto, C., Villata, M., Raiteri, C. M., Larionov, V. M., Blinov, D. A., Grishina, T. S., Kopatskaya, E. N., Larionova, E. G., Nikiforova, A. A., Morozova, D. A., Troitskaya, Yu. V., Troitsky, I. S., Kurtanidze, O. M., Nikolashvili, M. G., Kurtanidze, S. O., Kimeridze, G. N., Chigladze, R. A., Strigachev, A., Sadun, A. C., Moody, J. W., Chen, W. P., Lin, H. C., Acosta-Pulido, J. A., Arévalo, M. J., Carnerero, M. I., González-Morales, P. A., Manilla-Robles, A., Jermak, H., Steele, I., Mundel, C., Benítez, E., Hiriart, D., Smith, P. S., Max-Moerbeck, W., Readhead, A. C. S., Richards, J. L., Hovatta, T., Lähteenmäki, A., Tornikoski, M., Tammi, J., Georganopoulos, M., and Baring, M. G.
Subjects: electron: energy, energy: emission, X-ray: energy spectrum, MAGIC, blazar, Cherenkov counter, gamma ray: VHE, injection, correlation, synchrotron, fractional, spectral, energy: density, VERITAS, gamma ray: flux, Compton scattering
Abstract: Astronomy and astrophysics 620, A181 (2018). doi:10.1051/0004-6361/201833704, A multiwavelength campaign was organized to take place between March and July of 2012. Excellent temporal coverage was obtained with more than 25 instruments, including the MAGIC, FACT and VERITAS Cherenkov telescopes, the instruments on board the Swift and Fermi spacecraft, and the telescopes operated by the GASP-WEBT collaboration. Mrk 501 showed a very high energy (VHE) gamma-ray flux above 0.2 TeV of $\sim$0.5 times the Crab Nebula flux (CU) for most of the campaign. The highest activity occurred on 2012 June 9, when the VHE flux was $\sim$3 CU, and the peak of the high-energy spectral component was found to be at $\sim$2 TeV. This study reports very hard X-ray spectra, and the hardest VHE spectra measured to date for Mrk 501. The fractional variability was found to increase with energy, with the highest variability occurring at VHE, and a significant correlation between the X-ray and VHE bands. The unprecedentedly hard X-ray and VHE spectra measured imply that their low- and high-energy components peaked above 5 keV and 0.5 TeV, respectively, during a large fraction of the observing campaign, and hence that Mrk 501 behaved like an extreme high-frequency- peaked blazar (EHBL) throughout the 2012 observing season. This suggests that being an EHBL may not be a permanent characteristic of a blazar, but rather a state which may change over time. The one-zone synchrotron self-Compton (SSC) scenario can successfully describe the segments of the SED where most energy is emitted, with a significant correlation between the electron energy density and the VHE gamma-ray activity, suggesting that most of the variability may be explained by the injection of high-energy electrons. The one-zone SSC scenario used reproduces the behaviour seen between the measured X-ray and VHE gamma-ray fluxes, and predicts that the correlation becomes stronger with increasing energy of the X-rays., Published by EDP Sciences, Les Ulis
Published: 2018
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13. Science with e-ASTROGAM: A space mission for MeV–GeV gamma-ray astrophysics

Author: De Angelis, A., Tatischeff, V., Grenier, I. A., McEnery, J., Mallamaci, M., Tavani, M., Oberlack, U., Hanlon, L., Walter, R., Argan, A., Von Ballmoos, P., Bulgarelli, A., Bykov, A., Hernanz, M., Kanbach, G., Kuvvetli, I., Pearce, M., Zdziarski, A., Conrad, J., Ghisellini, G., Harding, A., Isern, J., Leising, M., Longo, F., Madejski, G., Martinez, M., Mazziotta, M. N., Paredes, J. M., Pohl, Martin, Rando, R., Razzano, M., Aboudan, A., Ackermann, M., Addazi, A., Ajello, M., Albertus, C., Álvarez, J. M., Ambrosi, G., Antón, S., Antonelli, L. A., Babic, A., Baibussinov, B., Balbo, M., Baldini, L., Balman, S., Bambi, C., Barres De Almeida, U., Barrio, J. A., Bartels, R., Bastieri, D., Bednarek, W., Bernard, D., Bernardini, E., Bernasconi, T., Bertucci, B., Biland, A., Bissaldi, E., Boettcher, M., Bonvicini, V., Bosch-Ramon, V., Bottacini, E., Bozhilov, V., Bretz, T., Branchesi, M., Brdar, V., Bringmann, T., Brogna, A., Budtz Jørgensen, C., Busetto, G., Buson, S., Busso, M., Caccianiga, A., Camera, S., Campana, R., Caraveo, P., Cardillo, M., Carlson, P., Celestin, S., Cermeño, M., Chen, A., Cheung, C. C., Churazov, E., Ciprini, S., Coc, A., Colafrancesco, S., Coleiro, A., Collmar, W., Coppi, P., Curado Da Silva, R., Cutini, S., D'Ammando, F., De Lotto, B., De Martino, D., De Rosa, A., Del Santo, M., Delgado, L., Diehl, R., Dietrich, S., Dolgov, A. D., Domínguez, A., Dominis Prester, D., Donnarumma, I., Dorner, D., Doro, M., Dutra, M., Elsaesser, D., Fabrizio, M., Fernández-Barral, A., Fioretti, V., Foffano, L., Formato, V., Fornengo, N., Foschini, L., Franceschini, A., Franckowiak, A., Funk, S., Fuschino, F., Gaggero, D., Galanti, G., Gargano, F., Gasparrini, D., Gehrz, R., Giammaria, P., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Ghirlanda, G., Godinovic, N., Gouiffés, C., Grove, J. E., Hamadache, C., Hartmann, D. H., Hayashida, M., Hryczuk, A., Jean, P., Johnson, T., José, J., Kaufmann, S., Khelifi, B., Kiener, J., Knödlseder, J., Kole, M., Kopp, J., Kozhuharov, V., Labanti, C., Lalkovski, S., Laurent, P., Limousin, O., Linares, M., Lindfors, E., Lindner, M., Liu, J., Lombardi, S., Loparco, F., López-Coto, R., López Moya, M., Lott, B., Lubrano, P., Malyshev, D., Mankuzhiyil, N., Mannheim, K., Marchã, M. J., Marcianò, A., Marcote, B., Mariotti, M., Marisaldi, M., McBreen, S., Mereghetti, S., Merle, A., Mignani, R., Minervini, G., Moiseev, A., Morselli, A., Moura, F., Nakazawa, K., Nava, L., Nieto, D., Orienti, M., Orio, M., Orlando, E., Orleanski, P., Paiano, S., Paoletti, R., Papitto, A., Pasquato, M., Patricelli, B., Pérez-García, M.Á., Persic, M., Piano, G., Pichel, A., Pimenta, M., Pittori, C., Porter, T., Poutanen, J., Prandini, E., Prantzos, N., Produit, N., Profumo, S., Queiroz, F. S., Rainó, S., Raklev, A., Regis, M., Reichardt, I., Rephaeli, Y., Rico, J., Rodejohann, W., Rodriguez Fernandez, G., Roncadelli, M., Roso, L., Rovero, A., Ruffini, R., Sala, G., Sánchez-Conde, M. A., Santangelo, A., Saz Parkinson, P., Sbarrato, T., Shearer, A., Shellard, R., Short, K., Siegert, T., Siqueira, C., Spinelli, P., Stamerra, A., Starrfield, S., Strong, A., Strümke, I., Tavecchio, F., Taverna, R., Terzić, T., Thompson, D. J., Tibolla, O., Torres, D. F., Turolla, R., Ulyanov, A., Ursi, A., Vacchi, A., Van Den Abeele, J., Vankova-Kirilovai, G., Venter, C., Verrecchia, F., Vincent, P., Wang, X., Weniger, C., Wu, X., Zaharijaš, G., Zampieri, L., Zane, S., Zimmer, S., and Zoglauer, A.
Abstract: Journal of high energy astrophysics 19, 1 - 106 (2018). doi:10.1016/j.jheap.2018.07.001, e-ASTROGAM (‘enhanced ASTROGAM’) is a breakthrough Observatory space mission, with a detector composed by a Silicon tracker, a calorimeter, and an anticoincidence system, dedicated to the study of the non-thermal Universe in the photon energy range from 0.3 MeV to 3 GeV – the lower energy limit can be pushed to energies as low as 150 keV for the tracker, and to 30 keV for calorimetric detection. The mission is based on an advanced space-proven detector technology, with unprecedented sensitivity, angular and energy resolution, combined with polarimetric capability. Thanks to its performance in the MeV–GeV domain, substantially improving its predecessors, e-ASTROGAM will open a new window on the non-thermal Universe, making pioneering observations of the most powerful Galactic and extragalactic sources, elucidating the nature of their relativistic outflows and their effects on the surroundings. With a line sensitivity in the MeV energy range one to two orders of magnitude better than previous generation instruments, e-ASTROGAM will determine the origin of key isotopes fundamental for the understanding of supernova explosion and the chemical evolution of our Galaxy. The mission will provide unique data of significant interest to a broad astronomical community, complementary to powerful observatories such as LIGO-Virgo-GEO600-KAGRA, SKA, ALMA, E-ELT, TMT, LSST, JWST, Athena, CTA, IceCube, KM3NeT, and LISA., Published by Elsevier, Amsterdam [u.a.]
Published: 2018
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14. A search for spectral hysteresis and energy-dependent time lags from X-ray and TeV gamma-ray observations of Mrk 421

Author: Abeysekara, A. U., Archambault, S., Chen, X., De Lotto, B., Wilhelmi, E. de Oña, Di Pierro, F., Doert, M., Domínguez, A., Prester, D. Dominis, Dorner, D., Doro, M., Einecke, S., Glawion, D. Eisenacher, Ciupik, L., Elsaesser, D., Engelkemeier, M., Ramazani, V. Fallah, Fernández-Barral, A., Fidalgo, D., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., López, R. J. García, Connolly, M. P., Garczarczyk, M., Gaug, M., Giammaria, P., Godinović, N., Gora, D., Guberman, D., Hadasch, D., Hahn, A., Hassan, T., Hayashida, M., Cui, W., Herrera, J., Hose, J., Hrupec, D., Hughes, G., Idec, W., Kodani, K., Konno, Y., Kubo, H., Kushida, J., Lelas, D., Eisch, J. D., Lindfors, E., Lombardi, S., Longo, F., López, M., López-Coto, R., Majumdar, P., Makariev, M., Mallot, K., Maneva, G., Manganaro, M., Falcone, A., Mannheim, K., Maraschi, L., Marcote, B., Mariotti, M., Martínez, M., Mazin, D., Menzel, U., Mirzoyan, R., Moralejo, A., Moretti, E., Feng, Q., Nakajima, D., Neustroev, V., Niedzwiecki, A., Rosillo, M. Nievas, Nilsson, K., Nishijima, K., Noda, K., Nogués, L., Nöthe, M., Paiano, S., Finley, J. P., Palacio, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Paredes-Fortuny, X., Pedaletti, G., Peresano, M., Perri, L., Persic, M., Fleischhack, H., Poutanen, J., Moroni, P. G. Prada, Prandini, E., Puljak, I., Garcia, J. R., Reichardt, I., Rhode, W., Ribó, M., Rico, J., Saito, T., Flinders, A., Satalecka, K., Schroeder, S., Schweizer, T., Shore, S. N., Sillanpää, A., Sitarek, J., Snidaric, I., Sobczynska, D., Stamerra, A., Strzys, M., Archer, A., Fortson, L., Surić, T., Takalo, L., Tavecchio, F., Temnikov, P., Terzić, T., Tescaro, D., Teshima, M., Torres, D. F., Torres-Albà, N., Toyama, T., Furniss, A., Treves, A., Vanzo, G., Acosta, M. Vazquez, Vovk, I., Ward, J. E., Will, M., Wu, M. H., Zanin, R., Hovatta, T., Perez, I. de la Calle, Griffin, S., Smith, P. S., Racero, E., Baloković, M., VERITAS Collaboration, MAGIC Collaboration, Hütten, M., Håkansson, N., Hanna, D., Hervet, O., Holder, J., Humensky, T. B., Kaaret, P., Benbow, W., Kar, P., Kertzman, M., Kieda, D., Krause, Maria, Kumar, S., Lang, M. J., Maier, G., McArthur, S., McCann, A., Meagher, K., Bird, R., Moriarty, P., Mukherjee, R., Nieto, D., O'Brien, S., Ong, R. A., Otte, A. N., Park, N., Pelassa, V., Pohl, Martin, Popkow, A., Buchovecky, M., Pueschel, E., Ragan, K., Reynolds, P. T., Richards, G. T., Roache, E., Sadeh, I., Santander, M., Sembroski, G. H., Shahinyan, K., Staszak, D., Buckley, J. H., Telezhinsky, I., Tucci, J. V., Tyler, J., Wakely, S. P., Weinstein, A., Wilhelm, Alina, Williams, D. A., Ahnen, M. L., Ansoldi, S., Antonelli, L. A., Bugaev, V., Antoranz, P., Arcaro, C., Babic, A., Banerjee, B., Bangale, P., de Almeida, U. Barres, Barrio, J. A., González, J. Becerra, Bednarek, W., Bernardini, E., Cardenzana, J. V, Berti, A., Biasuzzi, B., Biland, A., Blanch, O., Bonnefoy, S., Bonnoli, G., Borracci, F., Bretz, T., Carosi, R., Carosi, A., Cerruti, M., Chatterjee, A., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Cumani, P., Da Vela, P., Dazzi, F., De Angelis, A., Department of Radio Science and Engineering, Aalto-yliopisto, Aalto University, Universitat de Barcelona, Abeysekara, A. U., Archambault, S., Archer, A., Benbow, W., Bird, R., Buchovecky, M., Buckley, J. H., Bugaev, V., Cardenzana, J. V., Cerruti, M., Chen, X., Ciupik, L., Connolly, M. P., Cui, W., Eisch, J. D., Falcone, A., Feng, Q., Finley, J. P., Fleischhack, H., Flinders, A., Fortson, L., Furniss, A., Griffin, S., Hakansson, M. H. N., Hanna, D., Hervet, O., Holder, J., Humensky, T. B., Kaaret, P., Kar, P., Kertzman, M., Kieda, D., Krause, M., Kumar, S., Lang, M. J., Maier, G., Mcarthur, S., Mccann, A., Meagher, K., Moriarty, P., Mukherjee, R., Nieto, D., Ong, S. O. R. A., Otte, A. N., Park, N., Pelassa, V., Pohl, M., Popkow, A., Pueschel, E., Ragan, K., Reynolds, P. T., Richards, G. T., Roache, E., Sadeh, I., Santander, M., Sembroski, G. H., Shahinyan, K., Staszak, D., Telezhinsky, I., Tucci, J. V., Tyler, J., Wakely, S. P., Weinstein, A., Wilhelm, A., Williams, D. A., Ahnen, M. L., Ansoldi, S., Antonelli, L. A., Antoranz, P., Arcaro, C., Babic, A., Banerjee, B., Bangale, P., Almeida, U. Barres De, Barrio, J. A., González, J. Becerra, Bednarek, W., Bernardini, E., Berti, Alessio, Biasuzzi, B., Biland, A., Blanch, O., Bonnefoy, S., Bonnoli, G., Borracci, F., Bretz, T., Carosi, R., Carosi, A., Chatterjee, A., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Cumani, P., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., De Ona Wilhelmi, E., Di Pierro, F., Doert, M., Domínguez, A., Prester, D. Domini, Dorner, D., Doro, M., Einecke, S., Glawion, D. Eisenacher, Elsaesser, D., Engelkemeier, M., Ramazani, V. Fallah, Fernández Barral, A., Fidalgo, D., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., López, R. J. García, Garczarczyk, M., Gaug, M., Giammaria, P., Godinović, N., Gora, D., Guberman, D., Hadasch, D., Hahn, A., Hassan, T., Hayashida, M., Herrera, J., Hose, J., Hrupec, D., Hughes, G., Idec, W., Kodani, K., Konno, Y., Kubo, H., Kushida, J., Lelas, D., Lindfors, E., Lombardi, S., Longo, Francesco, López, M., López Coto, R., Majumdar, P., Makariev, M., Mallot, K., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Marcote, B., Mariotti, M., Martínez, M., Mazin, D., Menzel, U., Mirzoyan, R., Moralejo, A., Moretti, E., Nakajima, D., Neustroev, V., Niedzwiecki, A., Rosillo, M. Nieva, Nilsson, K., Nishijima, K., Noda, K., Nogués, L., Nöthe, M., Paiano, S., Palacio, J., Palatiello, Michele, Paneque, D., Paoletti, R., Paredes, J. M., Paredes Fortuny, X., Pedaletti, G., Peresano, M., Perri, L., Persic, M., Poutanen, J., Moroni, P. G. Prada, Prandini, E., Puljak, I., Garcia, J. R., Reichardt, I., Rhode, W., Ribó, M., Rico, J., Saito, T., Satalecka, K., Schroeder, S., Schweizer, T., Shore, S. N., Sillanp, A., Sitarek, J., Snidaric, I., Sobczynska, D., Stamerra, A., Strzys, M., Surić, T., Takalo, L., Tavecchio, F., Temnikov, P., Terzić, T., Tescaro, D., Teshima, M., Torres, D. F., Torres Albà, N., Toyama, T., Treves, A., Vanzo, G., Acosta, M. Vazquez, Vovk, I., Ward, J. E., Will, M., Wu, M. H., Zanin, R., Hovatta, T., De La Calle Perez, I., Smith, P. S., Racero, E., and Baloković, M.
Subjects: bl-lacertae objects, blazars, Astrophysics, telescope, 01 natural sciences, Spectral line, individual (Markarian 421) [BL Lacertae objects], law.invention, Raigs gamma, law, emission, MAGIC (telescope), 010303 astronomy & astrophysics, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Spectral index, Gamma ray, Radius, lac objects, non-thermal [radiation mechanisms], Synchrotron, xmm-newton, BL Lacertae objects: individual (Markarian 421), galaxies: active, gamma rays: general, radiation mechanisms: non-thermal, Astronomy and Astrophysics, Space and Planetary Science, correlated variability, active [galaxies], Física nuclear, Astrophysics - High Energy Astrophysical Phenomena, multiwavelength observations, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, 0103 physical sciences, Blazar, 010308 nuclear & particles physics, Gamma rays, Spectral density, Astronomy and Astrophysic, Galaxies, Galàxies, active galactic nuclei, markarian-421, ddc:520, galaxies: active – BL Lacertae objects: individual: (Markarian 421), general [gamma rays]
Abstract: The astrophysical journal 834(1), 2 (2017). doi:10.3847/1538-4357/834/1/2, Blazars are variable emitters across all wavelengths over a wide range of timescales, from months down to minutes. It is therefore essential to observe blazars simultaneously at different wavelengths, especially in the X-ray and gamma-ray bands, where the broadband spectral energy distributions usually peak. In this work, we report on three "target-of-opportunity" observations of Mrk 421, one of the brightest TeV blazars, triggered by a strong flaring event at TeV energies in 2014. These observations feature long, continuous, and simultaneous exposures with XMM-Newton (covering the X-ray and optical/ultraviolet bands) and VERITAS (covering the TeV gamma-ray band), along with contemporaneous observations from other gamma-ray facilities (MAGIC and Fermi-Large Area Telescope) and a number of radio and optical facilities. Although neither rapid flares nor significant X-ray/TeV correlation are detected, these observations reveal subtle changes in the X-ray spectrum of the source over the course of a few days. We search the simultaneous X-ray and TeV data for spectral hysteresis patterns and time delays, which could provide insight into the emission mechanisms and the source properties (e.g., the radius of the emitting region, the strength of the magnetic field, and related timescales). The observed broadband spectra are consistent with a one-zone synchrotron self-Compton model. We find that the power spectral density distribution at $\gtrsim$ 4 × 10$^{−4}$ Hz from the X-ray data can be described by a power-law model with an index value between 1.2 and 1.8, and do not find evidence for a steepening of the power spectral index (often associated with a characteristic length scale) compared to the previously reported values at lower frequencies., Published by IOP Publ., Chicago, Ill. [u.a.]
Published: 2016
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15. Performance of the MAGIC telescopes under moonlight

Author: Ahnen, M. L., Ansoldi, S., Antonelli, L. A., Arcaro, C., Babić, A., Banerjee, B., Bangale, P., Barres De Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bernardini, E., Berti, A., Bhattacharyya, W., Biasuzzi, B., Biland, A., Blanch, O., Bonnefoy, S., Bonnoli, G., Carosi, R., Carosi, A., Chatterjee, A., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Cumani, P., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., De Oña Wilhelmi, E., Di Pierro, F., Doert, M., Domínguez, A., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Eisenacher Glawion, D., Elsaesser, D., Engelkemeier, M., Fallah Ramazani, V., Fernández-Barral, A., Fidalgo, D., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., García López, R. J., Garczarczyk, M., Gaug, M., Giammaria, P., Godinović, N., Gora, D., Griffiths, S., Guberman, D., Hadasch, D., Hahn, A., Hassan, T., Hayashida, M., Herrera, J., Hose, J., Hrupec, D., Hughes, G., Ishio, K., Konno, Y., Kubo, H., Kushida, J., Kuveždić, D., Lelas, D., Lindfors, E., Lombardi, S., Longo, F., López, M., Maggio, C., Majumdar, P., Makariev, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Mazin, D., Menzel, U., Minev, M., Mirzoyan, R., Moralejo, A., Moreno, V., Moretti, E., Neustroev, V., Niedzwiecki, A., Nievas Rosillo, M., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Paiano, S., Palacio, J., Paneque, D., Paoletti, R., Paredes, J. M., Paredes-Fortuny, X., Pedaletti, G., Peresano, M., Perri, L., Persic, M., Prada Moroni, P. G., Prandini, E., Puljak, I., Garcia, J. R., Reichardt, I., Rhode, W., Ribó, M., Rico, J., Rugliancich, A., Saito, T., Satalecka, K., Schroeder, S., Schweizer, T., Sillanpää, A., Sitarek, J., Šnidarić, I., Sobczynska, D., Stamerra, A., Strzys, M., Surić, T., Takalo, L., Tavecchio, F., Temnikov, P., Terzić, T., Tescaro, D., Teshima, M., Torres, D. F., Torres-Albà, N., Treves, A., Vanzo, G., Vazquez Acosta, M., Vovk, I., Ward, J. E., Will, M., and Zarić, D.
Abstract: Astroparticle physics 94, 29 - 41 (2017). doi:10.1016/j.astropartphys.2017.08.001, MAGIC, a system of two imaging atmospheric Cherenkov telescopes, achieves its best performance under dark conditions, i.e. in absence of moonlight or twilight. Since operating the telescopes only during dark time would severely limit the duty cycle, observations are also performed when the Moon is present in the sky. Here we develop a dedicated Moon-adapted analysis to characterize the performance of MAGIC under moonlight. We evaluate energy threshold, angular resolution and sensitivity of MAGIC under different background light levels, based on Crab Nebula observations and tuned Monte Carlo simulations. This study includes observations taken under non-standard hardware configurations, such as reducing the camera photomultiplier tubes gain by a factor ∼ 1.7 (reduced HV settings) with respect to standard settings (nominal HV) or using UV-pass filters to strongly reduce the amount of moonlight reaching the cameras of the telescopes. The Crab Nebula spectrum is correctly reconstructed in all the studied illumination levels, that reach up to 30 times brighter than under dark conditions. The main effect of moonlight is an increase in the analysis energy threshold and in the systematic uncertainties on the flux normalization. The sensitivity degradation is constrained to be below 10%, within 15–30% and between 60 and 80% for nominal HV, reduced HV and UV-pass filter observations, respectively. No worsening of the angular resolution was found. Thanks to observations during moonlight, the maximal duty cycle of MAGIC can be increased from ∼ 18%, under dark nights only, to up to ∼ 40% in total with only moderate performance degradation., Published by Elsevier, Amsterdam [u.a.]
Published: 2017
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16. Multiwavelength observations of a VHE gamma-ray flare from PKS 1510−089 in 2015

Author: Ahnen, M. L., Ansoldi, S., Antonelli, L. A., Arcaro, C., Babić, A., Banerjee, B., Bangale, P., Barres De Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bernardini, E., Berti, A., Biasuzzi, B., Biland, A., Blanch, O., Bonnefoy, S., Bonnoli, G., Borracci, F., Bretz, T., Carosi, R., Carosi, A., Chatterjee, A., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Cumani, P., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., De Oña Wilhelmi, E., Di Pierro, F., Doert, M., Domínguez, A., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Eisenacher Glawion, D., Elsaesser, D., Engelkemeier, M., Fallah Ramazani, V., Fernández-Barral, A., Fidalgo, D., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., García López, R. J., Garczarczyk, Markus, Gaug, M., Giammaria, P., Godinović, N., Gora, D., Guberman, D., Hadasch, D., Hahn, A., Hassan, T., Hayashida, M., Herrera, J., Hose, J., Hrupec, D., Hughes, G., Ishio, K., Konno, Y., Kushida, J., Kuveždić, D., Lelas, D., Lindfors, E., Lombardi, S., Longo, F., López, M., Majumdar, P., Makariev, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Mazin, D., Menzel, U., Mirzoyan, R., Moralejo, A., Moretti, E., Nakajima, D., Neustroev, V., Niedzwiecki, A., Nievas Rosillo, M., Nilsson, K., Nishijima, K., Noda, K., Nogués, L., Paiano, S., Palacio, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Paredes-Fortuny, X., Pedaletti, G., Peresano, M., Perri, L., Persic, M., Poutanen, J., Prada Moroni, P. G., Prandini, E., Puljak, I., Garcia, J. R., Reichardt, I., Rhode, W., Ribó, M., Rico, J., Saito, T., Satalecka, K., Schroeder, S., Schweizer, T., Shore, S. N., Sillanpää, A., Sitarek, J., Šnidarić, I., Sobczynska, D., Stamerra, A., Strzys, M., Surić, T., Takalo, L., Tavecchio, F., Temnikov, P., Terzić, T., Tescaro, D., Teshima, M., Torres, D. F., Torres-Albà, N., Toyama, T., Treves, A., Vanzo, G., Vazquez Acosta, M., Vovk, I., Ward, J. E., Will, M., Wu, M. H., Zarić, D., Desiante, R., D'Ammando, F., Larsson, S., Raiteri, C. M., Reinthal, R., Lähteenmäki, A., Järvelä, E., Tornikoski, M., Ramakrishnan, V., Jorstad, S. G., Marscher, A. P., Bala, V., MacDonald, N. R., Kaur, N., Sameer, Baliyan, K., Acosta-Pulido, J. A., Lazaro, C., Martínez-Lombilla, C., Grinon-Marin, A. B., Yabar, A. Pastor, Protasio, C., Carnerero, M. I., Jermak, H., Steele, I. A., Larionov, V. M., Borman, G. A., and Grishina, T. S.
Subjects: X-ray, flux, gamma ray: VHE, spectral, quasar, polarization: optical, rotation, MAGIC
Abstract: Astronomy and astrophysics 603, A29 (2017). doi:10.1051/0004-6361/201629960, Context. PKS 1510−089 is one of only a few flat spectrum radio quasars detected in the very-high-energy (VHE, > 100 GeV) gamma-ray band. Aims. We study the broadband spectral and temporal properties of the PKS 1510−089 emission during a high gamma-ray state. Methods. We performed VHE gamma-ray observations of PKS 1510−089 with the Major Atmospheric Gamma Imaging Cherenkov (MAGIC) telescopes during a long, high gamma-ray state in May 2015. In order to perform broadband modeling of the source, we have also gathered contemporaneous multiwavelength data in radio, IR, optical photometry and polarization, UV, X-ray, and GeV gamma-ray ranges. We construct a broadband spectral energy distribution (SED) in two periods, selected according to VHE gamma-ray state. Results. PKS 1510−089 was detected by MAGIC during a few day-long observations performed in the middle of a long, high optical and gamma-ray state, showing for the first time a significant VHE gamma-ray variability. Similarly to the optical and gamma-ray high state of the source detected in 2012, it was accompanied by a rotation of the optical polarization angle and the emission of a new jet component observed in radio. However, owing to large uncertainty on the knot separation time, the association with the VHE gamma-ray emission cannot be firmly established. The spectral shape in the VHE band during the flare is similar to those obtained during previous measurements of the source. The observed flux variability sets constraints for the first time on the size of the region from which VHE gamma rays are emitted. We model the broadband SED in the framework of the external Compton scenario and discuss the possible emission site in view of multiwavelength data and alternative emission models. Key words: galaxies: active / galaxies: jets / gamma rays: galaxies / quasars: individual: PKS 1510-089, Published by EDP Sciences, Les Ulis
Published: 2017
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17. Prospects for Cherenkov Telescope Array Observations of the Young Supernova Remnant RX J1713.7-3946

Author: Acero, F., Aloisio, R., Amans, J., Amato, E., Antonelli, L. A., Aramo, C., Armstrong, T., Arqueros, F., Asano, K., Ashley, M., Backes, M., Balazs, C., Balzer, A., Bamba, A., Barkov, M., Barrio, J. A., Benbow, W., Bernl?Hr, K., Beshley, V., Bigongiari, C., Biland, A., Bilinsky, A., Bissaldi, E., Biteau, J., Blanch, O., Blasi, P., Blazek, J., Boisson, C., Bonanno, G., Bonardi, A., Bonavolont?, C., Bonnoli, G., Braiding, C., Brau-Nogu?, S., Bregeon, J., Brown, A. M., Bugaev, V., Bulgarelli, A., Bulik, T., Burton, M., Burtovoi, A., Busetto, G., B?Ttcher, M., Cameron, R., Capalbi, M., Caproni, A., Caraveo, P., Carosi, R., Cascone, E., Cerruti, M., Chaty, S., Chen, A., Chen, X., Chernyakova, M., Chikawa, M., Chudoba, J., Cohen-Tanugi, J., Colafrancesco, S., Conforti, V., Contreras, J. L., Costa, A., Cotter, G., Covino, S., Covone, G., Cumani, P., Cusumano, G., D?Ammando, F., D?Urso, D., Daniel, M., Dazzi, F., De Angelis, A., De Cesare, G., De Franco, A., De Frondat, F., De Gouveia Dal Pino, E. M., De Lisio, C., De Los Reyes Lopez, R., De Lotto, B., De Naurois, M., De Palma, F., Del Santo, M., Delgado, C., Della Volpe, D., Di Girolamo, T., Di Giulio, C., Di Pierro, F., Di Venere, L., Doro, M., Dournaux, J., Dumas, D., Dwarkadas, V., D?Az, C., Ebr, J., Egberts, K., Einecke, S., Els?Sser, D., Eschbach, S., Falceta-Goncalves, D., Fasola, G., Fedorova, E., Fern?Ndez-Barral, A., Ferrand, G., Fesquet, M., Fiandrini, E., Fiasson, A., Filipov?C, M. D., Fioretti, V., Font, L., Fontaine, G., Franco, F. J., Coromina, L. Freixas, Fujita, Y., Fukui, Y., Funk, S., F?Rster, A., Gadola, A., L?Pez, R. Garcia, Garczarczyk, M., Giglietto, N., Giordano, F., Giuliani, A., Glicenstein, J., Gnatyk, R., Goldoni, P., Grabarczyk, T., Graciani, R., Graham, J., Grandi, P., Granot, J., Green, A. J., Griffiths, S., Gunji, S., Hakobyan, H., Hara, S., Hassan, T., Hayashida, M., Heller, M., Helo, J. C., Hinton, J., Hnatyk, B., Huet, J., Huetten, Moritz, Humensky, T. B., Hussein, M., H?Randel, J., Ikeno, Y., Inada, T., Inome, Y., Inoue, S., Inoue, T., Inoue, Y., Ioka, K., Iori, M., Jacquemier, J., Janecek, P., Jankowsky, D., Jung, I., Kaaret, P., Katagiri, H., Kimeswenger, S., Kimura, S., Kn?Dlseder, J., Koch, B., Kocot, J., Kohri, K., Komin, N., Konno, Y., Kosack, K., Koyama, S., Kraus, M., Kubo, H., Mezek, G. Kukec, Kushida, J., Palombara, N. La, Lalik, K., Lamanna, G., Landt, H., Lapington, J., Laporte, P., Lee, S., Lees, J., Lefaucheur, J., Lenain, J.-P., Leto, G., Lindfors, E., Lohse, T., Lombardi, S., Longo, F., Lopez, M., Lucarelli, F., Luque-Escamilla, P. L., L?Pez-Coto, R., Maccarone, M. C., Maier, G., Malaguti, G., Mandat, D., Maneva, G., Mangano, S., Marcowith, A., Mart?, J., Mart?Nez, M., Mart?Nez, G., Masuda, S., Maurin, G., Maxted, N., Melioli, C., Mineo, T., Mirabal, N., Mizuno, T., Moderski, R., Mohammed, M., Montaruli, T., Moralejo, A., Mori, K., Morlino, G., Morselli, A., Moulin, E., Mukherjee, R., Mundell, C., Muraishi, H., Murase, K., Nagataki, S., Nagayoshi, T., Naito, T., Nakajima, D., Nakamori, T., Nemmen, R., Niemiec, J., Nieto, D., Nievas-Rosillo, M., Niko?Ajuk, M., Nishijima, K., Noda, K., Nogues, L., Nosek, D., Novosyadlyj, B., Nozaki, S., Ohira, Y., Ohishi, M., Ohm, S., Okumura, A., Ong, R. A., Orito, R., Orlati, A., Ostrowski, M., Oya, I., Padovani, M., Palacio, J., Palatka, M., Paredes, J. M., Pavy, S., Pe?Er, A., Persic, M., Petrucci, P., Petruk, O., Pisarski, A., Pohl, M., Porcelli, A., Prandini, E., Prast, J., Principe, G., Prouza, M., Pueschel, E., P?Hlhofer, G., Quirrenbach, A., Rameez, M., Reimer, O., Renaud, M., Rib?, M., Rico, J., Rizi, V., Rodriguez, J., Fernandez, G. Rodriguez, V?Zquez, J. J. Rodr?Guez, Romano, P., Romeo, G., Rosado, J., Rousselle, J., Rowell, G., Rudak, B., Sadeh, I., Safi-Harb, S., Saito, T., Sakaki, N., Sanchez, D., Sangiorgi, P., Sano, H., Santander, M., Sarkar, S., Sawada, M., Schioppa, E. J., Schoorlemmer, H., Schovanek, P., Schussler, F., Sergijenko, O., Servillat, M., Shalchi, A., Shellard, R. C., Siejkowski, H., Sillanp??, A., Simone, D., Sliusar, V., Sol, H., Stani?, S., Starling, R., Stawarz, ?., Stefanik, S., Stephan, M., Stolarczyk, T., Szanecki, M., Szepieniec, T., Tagliaferri, G., Tajima, H., Takahashi, M., Takeda, J., Tanaka, M., Tanaka, S., Tejedor, L. A., Telezhinsky, I., Temnikov, P., Terada, Y., Tescaro, D., Teshima, M., Testa, V., Thoudam, S., Tokanai, F., Torres, D. F., Torresi, E., Tosti, G., Townsley, C., Travnicek, P., Trichard, C., Trifoglio, M., Tsujimoto, S., Vagelli, V., Vallania, P., Valore, L., Van Driel, W., Van Eldik, C., Vandenbroucke, J., Vassiliev, V., Vecchi, M., Vercellone, S., Vergani, S., Vigorito, C., Vorobiov, S., Vrastil, M., Acosta, M. L. V?Zquez, Wagner, S. J., Wagner, R., Wakely, S. P., Walter, R., Ward, J. E., Watson, J. J., Weinstein, A., White, M., White, R., Wierzcholska, A., Wilcox, P., Williams, D. A., Wischnewski, R., Wojcik, P., Yamamoto, T., Yamamoto, H., Yamazaki, R., Yanagita, S., Yang, L., Yoshida, T., Yoshida, M., Yoshiike, S., Yoshikoshi, T., Zacharias, M., Zampieri, L., Zanin, R., Zavrtanik, M., Zavrtanik, D., Zdziarski, A., Zech, A., Zechlin, H., Zhdanov, V., Ziegler, A., and Zorn, J.
Abstract: The astrophysical journal 840(2), 74 (2017). doi:10.3847/1538-4357/aa6d67, We perform simulations for future Cherenkov Telescope Array (CTA) observations of RX J1713.7−3946, a young supernova remnant (SNR) and one of the brightest sources ever discovered in very high energy (VHE) gamma rays. Special attention is paid to exploring possible spatial (anti)correlations of gamma rays with emission at other wavelengths, in particular X-rays and CO/H i emission. We present a series of simulated images of RX J1713.7−3946 for CTA based on a set of observationally motivated models for the gamma-ray emission. In these models, VHE gamma rays produced by high-energy electrons are assumed to trace the nonthermal X-ray emission observed by XMM-Newton, whereas those originating from relativistic protons delineate the local gas distributions. The local atomic and molecular gas distributions are deduced by the NANTEN team from CO and H i observations. Our primary goal is to show how one can distinguish the emission mechanism(s) of the gamma rays (i.e., hadronic versus leptonic, or a mixture of the two) through information provided by their spatial distribution, spectra, and time variation. This work is the first attempt to quantitatively evaluate the capabilities of CTA to achieve various proposed scientific goals by observing this important cosmic particle accelerator., Published by IOP, Chicago, Ill. [u.a.]
Published: 2017
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18. A cut-off in the TeV gamma-ray spectrum of the SNR Cassiopeia A

Author: Ahnen, M. L., Ansoldi, S., Antonelli, L. A., Arcaro, C., Babić, A., Banerjee, B., Bangale, P., Barres De Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bernardini, E., Berti, A., Bhattacharyya, W., Biasuzzi, B., Biland, A., Blanch, O., Bonnefoy, S., Bonnoli, G., Carosi, R., Carosi, A., Chatterjee, A., Colak, M., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Cumani, P., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., De Oña Wilhelmi, E., Di Pierro, F., Doert, M., Domínguez, A., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Eisenacher Glawion, D., Elsaesser, D., Engelkemeier, M., Fallah Ramazani, V., Fernández-Barral, A., Fidalgo, D., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., García López, R. J., Garczarczyk, Markus, Gaug, M., Giammaria, P., Godinović, N., Gora, D., Guberman, D., Hadasch, D., Hahn, A., Hassan, T., Hayashida, M., Herrera, J., Hose, J., Hrupec, D., Inada, T., Ishio, K., Konno, Y., Kubo, H., Kushida, J., Kuveždić, D., Lelas, D., Lindfors, E., Lombardi, S., Longo, F., López, M., Maggio, C., Majumdar, P., Makariev, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Mazin, D., Menzel, U., Minev, M., Mirzoyan, R., Moralejo, A., Moreno, V., Moretti, E., Neustroev, V., Niedzwiecki, A., Nievas Rosillo, M., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Paiano, S., Palacio, J., Paneque, D., Paoletti, R., Paredes, J. M., Pedaletti, G., Peresano, M., Perri, L., Persic, M., Prada Moroni, P. G., Prandini, E., Puljak, I., Garcia, J. R., Reichardt, I., Rhode, W., Ribó, M., Rico, J., Righi, C., Saito, T., Satalecka, K., Schroeder, S., Schweizer, T., Shore, S. N., Sitarek, J., Šnidarić, I., Sobczynska, D., Stamerra, A., Strzys, M., Surić, T., Takalo, L., Tavecchio, F., Temnikov, P., Terzić, T., Tescaro, D., Teshima, M., Torres-Albà, N., Treves, A., Vanzo, G., Vazquez Acosta, M., Vovk, I., Ward, J. E., Will, M., and Zarić, D.
Subjects: energy: high, lepton, magnetic field: low, energy spectrum, acceleration, power spectrum, gamma ray: energy spectrum, MAGIC, GLAST, moment, flux, gamma ray: emission, cosmic radiation: galaxy, supernova, spectral, model: leptonic
Abstract: Monthly notices of the Royal Astronomical Society 472(3), 2956 - 2962 (2017). doi:10.1093/mnras/stx2079, It is widely believed that the bulk of the Galactic cosmic rays is accelerated in supernova remnants (SNRs). However, no observational evidence of the presence of particles of PeV energies in SNRs has yet been found. The young historical SNR Cassiopeia A (Cas A) appears as one of the best candidates to study acceleration processes. Between 2014 December and 2016 October, we observed Cas A with the MAGIC telescopes, accumulating 158 h of good quality data. We derived the spectrum of the source from 100 GeV to 10 TeV. We also analysed ∼8 yr of Fermi-LAT to obtain the spectral shape between 60 MeV and 500 GeV. The spectra measured by the LAT and MAGIC telescopes are compatible within the errors and show a clear turn-off (4.6σ) at the highest energies, which can be described with an exponential cut-off at $E_c = 3.5(^{+1.6}_{-1.0})_{{\rm stat}} (^{+0.8}_{-0.9})_{{\rm sys}}$ TeV. The gamma-ray emission from 60 MeV to 10 TeV can be attributed to a population of high-energy protons with a spectral index of ∼2.2 and an energy cut-off at ∼10 TeV. This result indicates that Cas A is not contributing to the high energy (∼PeV) cosmic ray sea in a significant manner at the present moment. A one-zone leptonic model fails to reproduce by itself the multiwavelength spectral energy distribution. Besides, if a non-negligible fraction of the flux seen by MAGIC is produced by leptons, the radiation should be emitted in a region with a low magnetic field (B⪅180 μG) like in the reverse shock., Published by Oxford Univ. Press, Oxford
Published: 2017
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19. Search for very high-energy gamma-ray emission from the microquasar Cygnus X-1 with the MAGIC telescopes

Author: MAGIC Collaboration, Ahnen, M. L., Ansoldi, S., Antonelli, L. A., Arcaro, C., Babić, A., Banerjee, B., Bangale, P., De Almeida, U. Barres, Barrio, J. A., González, J. Becerra, Bednarek, W., Bernardini, E., Berti, A., Bhattacharyya, W., Biasuzzi, B., Biland, A., Blanch, O., Bonnefoy, S., Bonnoli, G., Carosi, R., Carosi, A., Chatterjee, A., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Cumani, P., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Wilhelmi, E. De Oña, Di Pierro, F., Doert, M., Domínguez, A., Prester, D. Dominis, Dorner, D., Doro, M., Einecke, S., Glawion, D. Eisenacher, Elsaesser, D., Engelkemeier, M., Ramazani, V. Fallah, Fernández-Barral, A., Fidalgo, D., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., López, R. J. García, Garczarczyk, M., Gaug, M., Giammaria, P., Godinović, N., Gora, D., Guberman, D., Hadasch, D., Hahn, A., Hassan, T., Hayashida, M., Herrera, J., Hose, J., Hrupec, D., Ishio, K., Konno, Y., Kubo, H., Kushida, J., Kuveždić, D., Lelas, D., Lindfors, E., Lombardi, S., Longo, F., López, M., Maggio, C., Majumdar, P., Makariev, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Mazin, D., Menzel, U., Minev, M., Mirzoyan, R., Moralejo, A., Moreno, V., Moretti, E., Neustroev, V., Niedzwiecki, A., Rosillo, M. Nievas, Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Paiano, S., Palacio, J., Paneque, D., Paoletti, R., Paredes, J. M., Paredes-Fortuny, X., Pedaletti, G., Peresano, M., Perri, L., Persic, M., Moroni, P. G. Prada, Prandini, E., Puljak, I., Garcia, J. R., Reichardt, I., Rhode, W., Ribó, M., Rico, J., Righi, C., Saito, T., Satalecka, K., Schroeder, S., Schweizer, T., Sitarek, J., Šnidarić, I., Sobczynska, D., Stamerra, A., Strzys, M., Surić, T., Takalo, L., Tavecchio, F., Temnikov, P., Terzić, T., Tescaro, D., Teshima, M., Torres, D. F., Torres-Albà, N., Treves, A., Vanzo, G., Acosta, M. Vazquez, Vovk, I., Ward, J. E., Will, M., Zarić, D., Bosch-Ramon, V., Pooley, G. G., Trushkin, S. A., and Zanin, R.
Abstract: Monthly notices of the Royal Astronomical Society 472(3), 3474 - 3485 (2017). doi:10.1093/mnras/stx2087, The microquasar Cygnus X-1 displays the two typical soft and hard X-ray states of a black-hole transient. During the latter, Cygnus X-1 shows a one-sided relativistic radio-jet. Recent detection of the system in the high energy (HE; $E\gtrsim60$ MeV) gamma-ray range with \textit{Fermi}-LAT associates this emission with the outflow. Former MAGIC observations revealed a hint of flaring activity in the very high-energy (VHE; $E\gtrsim100$ GeV) regime during this X-ray state. We analyze $\sim97$ hr of Cygnus X-1 data taken with the MAGIC telescopes between July 2007 and October 2014. To shed light on the correlation between hard X-ray and VHE gamma rays as previously suggested, we study each main X-ray state separately. We perform an orbital phase-folded analysis to look for variability in the VHE band. Additionally, to place this variability behavior in a multiwavelength context, we compare our results with \textit{Fermi}-LAT, \textit{AGILE}, \textit{Swift}-BAT, \textit{MAXI}, \textit{RXTE}-ASM, AMI and RATAN-600 data. We do not detect Cygnus X-1 in the VHE regime. We establish upper limits for each X-ray state, assuming a power-law distribution with photon index $\Gamma=3.2$. For steady emission in the hard and soft X-ray states, we set integral upper limits at 95\% confidence level for energies above 200 GeV at $2.6\times10^{-12}$~photons cm$^{-2}$s$^{-1}$ and $1.0\times10^{-11}$~photons cm$^{-2}$s$^{-1}$, respectively. We rule out steady VHE gamma-ray emission above this energy range, at the level of the MAGIC sensitivity, originating in the interaction between the relativistic jet and the surrounding medium, while the emission above this flux level produced inside the binary still remains a valid possibility., Published by Oxford Univ. Press, Oxford
Published: 2017
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20. Observation of the Black Widow B1957+20 millisecond pulsar binary system with the MAGIC telescopes

Author: Ahnen, M. L., Ansoldi, S., Antonelli, L. A., Arcaro, C., Babić, A., Banerjee, B., Bangale, P., Barres De Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bernardini, E., Berti, A., Biasuzzi, B., Biland, A., Blanch, O., Bonnefoy, S., Bonnoli, G., Borracci, F., Bretz, T., Carosi, R., Carosi, A., Chatterjee, A., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Cumani, P., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., De Oña Wilhelmi, E., Di Pierro, F., Doert, M., Domínguez, A., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Eisenacher Glawion, D., Elsaesser, D., Engelkemeier, M., Fallah Ramazani, V., Fernández-Barral, A., Fidalgo, D., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., García López, R. J., Garczarczyk, Markus, Gaug, M., Giammaria, P., Godinović, N., Gora, D., Griffiths, S., Guberman, D., Hadasch, D., Hahn, A., Hassan, T., Hayashida, M., Herrera, J., Hose, J., Hrupec, D., Hughes, G., Ishio, K., Konno, Y., Kubo, H., Kushida, J., Kuveždić, D., Lelas, D., Lindfors, E., Lombardi, S., Longo, F., López, M., Maggio, C., Majumdar, P., Makariev, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Mazin, D., Menzel, U., Minev, M., Mirzoyan, R., Moralejo, A., Moreno, V., Moretti, E., Neustroev, V., Niedzwiecki, A., Nievas Rosillo, M., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Paiano, S., Palacio, J., Paneque, D., Paoletti, R., Paredes, J. M., Paredes-Fortuny, X., Pedaletti, G., Peresano, M., Perri, L., Persic, M., Prada Moroni, P. G., Prandini, E., Puljak, I., Garcia, J. R., Reichardt, I., Rhode, W., Ribó, M., Rico, J., Saito, T., Satalecka, K., Schroeder, S., Schweizer, T., Shore, S. N., Sillanpää, A., Sitarek, J., Snidari´Csnidari´C, I. ˇ, Sobczynska, D., Stamerra, A., Strzys, M., Suri´Csuri´C, T., Takalo, L., Tavecchio, F., Temnikov, P., Terzi´Cterzi´C, T., Tescaro, D., Teshima, M., Torres, D. F., Torres-Albà, N., Treves, A., Vanzo, G., Vazquez Acosta, M., Vovk, I., Ward, J. E., Will, M., Zarić, D., Cognard, I., and Guillemot, L.
Subjects: radio wave, acceleration: efficiency, electron: acceleration, electron: injection, binary: compact, spin, MAGIC, GLAST, Compton scattering: inverse, gamma ray: VHE, star, pulsar: binary, frequency, mass, pulsar: emission, pulsar: interaction, upper limit, plasma
Abstract: Monthly notices of the Royal Astronomical Society 470(4), 4608 - 4617 (2017). doi:10.1093/mnras/stx1405, B1957+20 is a millisecond pulsar located in a black-widow-type compact binary system with a low-mass stellar companion. The interaction of the pulsar wind with the companion star wind and/or the interstellar plasma is expected to create plausible conditions for acceleration of electrons to TeV energies and subsequent production of very high-energy γ-rays in the inverse Compton process. We performed extensive observations with the Major Atmospheric Gamma Imaging Cherenkov Telescopes (MAGIC) telescopes of B1957+20. We interpret results in the framework of a few different models, namely emission from the vicinity of the millisecond pulsar, the interaction of the pulsar and stellar companion wind region or bow shock nebula. No significant steady very high-energy γ-ray emission was found. We derived a 95 per cent confidence level upper limit of 3.0 × 10$^{−12}$ cm$^{−2}$ s$^{−1}$ on the average γ-ray emission from the binary system above 200 GeV. The upper limits obtained with the MAGIC constrain, for the first time, different models of the high-energy emission in B1957+20. In particular, in the inner mixed wind nebula model with mono-energetic injection of electrons, the acceleration efficiency of electrons is constrained to be below ∼2–10 per cent of the pulsar spin-down power. For the pulsar emission, the obtained upper limits for each emission peak are well above the exponential cut-off fits to the Fermi-LAT data, extrapolated to energies above 50 GeV. The MAGIC upper limits can rule out a simple power-law tail extension through the sub-TeV energy range for the main peak seen at radio frequencies., Published by Oxford Univ. Press, Oxford
Published: 2017
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21. Detection of very high energy gamma-ray emission from the gravitationally lensed blazar QSO B0218+357 with the MAGIC telescopes

Author: Ahnen, M. L., Ansoldi, S., Antonelli, L. A., Antoranz, P., Arcaro, C., Babic, A., Banerjee, B., Bangale, P., Barres De Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bernardini, E., Berti, A., Biasuzzi, B., Biland, A., Blanch, O., Bonnefoy, S., Bonnoli, G., Borracci, F., Bretz, T., Buson, S., Carosi, A., Chatterjee, A., Clavero, R., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., De Oña Wilhelmi, E., Di Pierro, F., Doert, M., Domínguez, A., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Eisenacher Glawion, D., Elsaesser, D., Engelkemeier, M., Fallah Ramazani, V., Fernández-Barral, A., Fidalgo, D., Fonseca, M. V., Font, L., Frantzen, K., Fruck, C., Galindo, D., García López, R. J., Garczarczyk, M., Garrido Terrats, D., Gaug, M., Giammaria, P., Godinović, N., Gora, D., Guberman, D., Hadasch, D., Hahn, A., Hayashida, M., Herrera, J., Hose, J., Hrupec, D., Hughes, G., Idec, W., Kodani, K., Konno, Y., Kubo, H., Kushida, J., La Barbera, A., Lelas, D., Lindfors, E., Lombardi, S., Longo, F., López, M., López-Coto, R., Majumdar, P., Makariev, M., Mallot, K., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Marcote, B., Mariotti, M., Martínez, M., Mazin, D., Menzel, U., Miranda, J. M., Mirzoyan, R., Moralejo, A., Moretti, E., Nakajima, D., Neustroev, V., Niedzwiecki, A., Nievas Rosillo, M., Nilsson, K., Nishijima, K., Noda, K., Nogués, L., Paiano, S., Palacio, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Paredes-Fortuny, X., Pedaletti, G., Peresano, M., Perri, L., Persic, M., Poutanen, J., Prada Moroni, P. G., Prandini, E., Puljak, I., Garcia, J. R., Reichardt, I., Rhode, W., Ribó, M., Rico, J., Saito, T., Satalecka, K., Schroeder, S., Schweizer, T., Shore, S. N., Sillanpää, A., Sitarek, J., Snidaric, I., Sobczynska, D., Stamerra, A., Strzys, M., Surić, T., Takalo, L., Tavecchio, F., Temnikov, P., Terzić, T., Tescaro, D., Teshima, M., Torres, D. F., Toyama, T., Treves, A., Vanzo, G., Verguilov, V., Vovk, I., Ward, J. E., Will, M., Wu, M. H., Zanin, R., and Desiante, R.
Abstract: Astronomy and astrophysics 595, A98(2016). doi:10.1051/0004-6361/201629461, QSO B0218+357 is a gravitationally lensed blazar located at a redshift of 0.944. The gravitational lensing splits the emitted radiation into two components that are spatially indistinguishable by gamma-ray instruments, but separated by a 10–12 day delay. In July 2014, QSO B0218+357 experienced a violent flare observed by the Fermi-LAT and followed by the MAGIC telescopes.Aims. The spectral energy distribution of QSO B0218+357 can give information on the energetics of z ~ 1 very high energy gamma-ray sources. Moreover the gamma-ray emission can also be used as a probe of the extragalactic background light at z ~ 1.Methods. MAGIC performed observations of QSO B0218+357 during the expected arrival time of the delayed component of the emission. The MAGIC and Fermi-LAT observations were accompanied by quasi-simultaneous optical data from the KVA telescope and X-ray observations by Swift-XRT. We construct a multiwavelength spectral energy distribution of QSO B0218+357 and use it to model the source. The GeV and sub-TeV data obtained by Fermi-LAT and MAGIC are used to set constraints on the extragalactic background light.Results. Very high energy gamma-ray emission was detected from the direction of QSO B0218+357 by the MAGIC telescopes during the expected time of arrival of the trailing component of the flare, making it the farthest very high energy gamma-ray source detected to date. The observed emission spans the energy range from 65 to 175 GeV. The combined MAGIC and Fermi-LAT spectral energy distribution of QSO B0218+357 is consistent with current extragalactic background light models. The broadband emission can be modeled in the framework of a two-zone external Compton scenario, where the GeV emission comes from an emission region in the jet, located outside the broad line region., Published by EDP Sciences, Les Ulis
Published: 2016
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22. Multi-Wavelength Observations of the Blazar 1ES 1011+496 in Spring 2008

Author: Ahnen, M. L., Ansoldi, S., Antonelli, L. A., Antoranz, P., Babic, A., Banerjee, B., Bangale, P., De Almeida, U. Barres, Barrio, J. A., González, J. Becerra, Bednarek, W., Bernardini, E., Biasuzzi, B., Biland, A., Blanch, O., Bonnefoy, S., Bonnoli, G., Borracci, F., Bretz, T., Carmona, E., Carosi, A., Chatterjee, A., Clavero, R., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Da Vela, P., Dazzi, F., De Angelis, A., De Caneva, G., De Lotto, B., Wilhelmi, E. De O Na, Mendez, C. Delgado, Pierro, F. Di, Prester, D. Dominis, Dorner, D., Doro, M., Einecke, S., Elsaesser, D., Fernández-Barral, A., Fidalgo, D., Fonseca, M. V., Font, L., Frantzen, K., Fruck, C., Galindo, D., López, R. J. García, Garczarczyk, M., Terrats, D. Garrido, Gaug, M., Giammaria, P., Godinović, N., Muñoz, A. González, Guberman, D., Hanabata, Y., Hayashida, M., Herrera, J., Hose, J., Hrupec, D., Hughes, G., Idec, W., Kodani, K., Konno, Y., Kubo, H., Kushida, J., La Barbera, A., Lelas, D., Lindfors, E., Lombardi, S., Longo, F., López, M., López-Coto, R., López-Oramas, A., Lorenz, E., Majumdar, P., Makariev, M., Mallot, K., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Marcote, B., Mariotti, M., Martínez, M., Mazin, D., Menzel, U., Miranda, J. M., Mirzoyan, R., Moralejo, A., Nakajima, D., Neustroev, V., Niedzwiecki, A., Rosillo, M. Nievas, Nilsson, K., Nishijima, K., Noda, K., Orito, R., Overkemping, A., Paiano, S., Palacio, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Paredes-Fortuny, X., Persic, M., Poutanen, J., Moroni, P. G. Prada, Prandini, E., Puljak, I., Reinthal, R., Rhode, W., Ribó, M., Rico, J., Garcia, J. Rodriguez, Rügamer, S., Saito, T., Satalecka, K., Scapin, V., Schultz, C., Schweizer, T., Shore, S. N., Sillanpää, A., Sitarek, J., Snidaric, I., Sobczynska, D., Stamerra, A., Steinbring, T., Strzys, M., Takalo, L., Takami, H., Tavecchio, F., Temnikov, P., Terzić, T., Tescaro, D., Teshima, M., Thaele, J., Torres, D. F., Toyama, T., Treves, A., Verguilov, V., Vovk, I., Ward, J. E., Will, M., Wu, M. H., Zanin, R., Lucarelli, F., Pittori, C., Vercellone, S., Berdyugin, A., Carini, M. T., Lähteenmäki, A., Pasanen, M., Pease, A., Sainio, J., Tornikoski, M., and Walters, R.
Abstract: Monthly notices of the Royal Astronomical Society 459, 2286 - 2298 (2016). doi:10.1093/mnras/stw710, The BL Lac object 1ES 1011+496 was discovered at very high energy (VHE, E > 100GeV) γ-rays by Major Atmospheric Gamma-ray Imaging Cherenkov (MAGIC) in Spring 2007. Before that the source was little studied in different wavelengths. Therefore, a multiwavelength (MWL) campaign was organized in Spring 2008. Along MAGIC, the MWL campaign included the Metsähovi Radio Observatory, Bell and Kungliga Vetenskapsakademien (KVA) optical telescopes and the Swift and AGILE satellites. MAGIC observations span from 2008 March to May for a total of 27.9 h, of which 19.4 h remained after quality cuts. The light curve showed no significant variability yielding an integral flux above 200 GeV of (1.3 ± 0.3) × 10$^{−11}$ photons cm$^{−2}$ s$^{−1}$. The differential VHE spectrum could be described with a power-law function with a spectral index of 3.3 ± 0.4. Both results were similar to those obtained during the discovery. Swift X-ray Telescope observations revealed an X-ray flare, characterized by a harder-when-brighter trend, as is typical for high synchrotron peak BL Lac objects (HBL). Strong optical variability was found during the campaign, but no conclusion on the connection between the optical and VHE γ-ray bands could be drawn. The contemporaneous spectral energy distribution shows a synchrotron-dominated source, unlike concluded in previous work based on non-simultaneous data, and is well described by a standard one-zone synchrotron self-Compton model. We also performed a study on the source classification. While the optical and X-ray data taken during our campaign show typical characteristics of an HBL, we suggest, based on archival data, that 1ES 1011+496 is actually a borderline case between intermediate and high synchrotron peak frequency BL Lac objects., Published by Oxford Univ. Press, Oxford
Published: 2016
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23. Insights into the emission of the blazar 1ES 1011+496 through unprecedented broadband observations during 2011 and 2012

Author: Aleksić, J., Ansoldi, S., Antonelli, L. A., Antoranz, P., Arcaro, C., Babic, A., Bangale, P., Barres De Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bernardini, E., Biasuzzi, B., Biland, A., Blanch, O., Bonnefoy, S., Bonnoli, G., Borracci, F., Bretz, T., Carmona, E., Carosi, A., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Da Vela, P., Dazzi, F., De Angelis, A., De Caneva, G., De Lotto, B., De Oña Wilhelmi, E., Delgado Mendez, C., Di Pierro, F., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Eisenacher, D., Elsaesser, D., Fernández-Barral, A., Fidalgo, D., Fonseca, M. V., Font, L., Frantzen, K., Fruck, C., Galindo, D., García López, R. J., Garczarczyk, M., Garrido Terrats, D., Gaug, M., Godinović, N., González Muñoz, A., Gozzini, S. R., Hadasch, D., Hanabata, Y., Hayashida, M., Herrera, J., Hose, J., Hrupec, D., Idec, W., Kadenius, V., Kellermann, H., Knoetig, M. L., Kodani, K., Konno, Y., Krause, J., Kubo, H., Kushida, J., La Barbera, A., Lelas, D., Lewandowska, N., Lindfors, E., Lombardi, S., Longo, F., López, M., López-Coto, R., López-Oramas, A., Lorenz, E., Lozano, I., Makariev, M., Mallot, K., Maneva, G., Mannheim, K., Maraschi, L., Marcote, B., Mariotti, M., Martínez, M., Mazin, D., Menzel, U., Miranda, J. M., Mirzoyan, R., Moralejo, A., Munar-Adrover, P., Nakajima, D., Neustroev, V., Niedzwiecki, A., Nievas Rosillo, M., Nilsson, K., Nishijima, K., Noda, K., Orito, R., Overkemping, A., Paiano, S., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Paredes-Fortuny, X., Persic, M., Poutanen, J., Prada Moroni, P. G., Prandini, E., Puljak, I., Reinthal, R., Rhode, W., Ribó, M., Rico, J., Rodriguez Garcia, J., Saito, T., Saito, K., Satalecka, K., Scalzotto, V., Scapin, V., Schweizer, T., Shore, S. N., Sillanpää, A., Sitarek, J., Snidaric, I., Sobczynska, D., Stamerra, A., Steinbring, T., Strzys, M., Takalo, L., Takami, H., Tavecchio, F., Temnikov, P., Terzić, T., Tescaro, D., Teshima, M., Thaele, J., Torres, D. F., Toyama, T., Treves, A., Vogler, P., Will, M., Zanin, R., Buson, S., D’Ammando, F., Lähteenmäki, A., Hovatta, T., Kovalev, Y. Y., Lister, M. L., Max-Moerbeck, W., Mundell, C., Pushkarev, A. B., Rastorgueva-Foi, E., Readhead, A. C. S., Richards, J. L., Tammi, J., Sanchez, D. A., Tornikoski, M., Savolainen, T., and Steele, I.
Abstract: Astronomy and astrophysics 591, A10(2016). doi:10.1051/0004-6361/201527176, 1ES 1011+496 (z = 0.212) was discovered in very high-energy (VHE, E> 100 GeV) γ rays with MAGIC in 2007. The absence of simultaneous data at lower energies led to an incomplete characterization of the broadband spectral energy distribution (SED).Aims. We study the source properties and the emission mechanisms, probing whether a simple one-zone synchrotron self-Compton (SSC) scenario is able to explain the observed broadband spectrum.Methods. We analyzed data in the range from VHE to radio data from 2011 and 2012 collected by MAGIC, Fermi-LAT, Swift, KVA, OVRO, and Metsähovi in addition to optical polarimetry data and radio maps from the Liverpool Telescope and MOJAVE.Results. The VHE spectrum was fit with a simple power law with a photon index of 3.69 ± 0.22 and a flux above 150 GeV of (1.46 ± 0.16) × 10$^{-11}$ ph cm$^{-2}$ s$^{-1}$. The source 1ES 1011+496 was found to be in a generally quiescent state at all observed wavelengths, showing only moderate variability from radio to X-rays. A low degree of polarization of less than 10% was measured in optical, while some bright features polarized up to 60% were observed in the radio jet. A similar trend in the rotation of the electric vector position angle was found in optical and radio. The radio maps indicated a superluminal motion of 1.8 ± 0.4 c, which is the highest speed statistically significant measured so far in a high-frequency-peaked BL Lac.Conclusions. For the first time, the high-energy bump in the broadband SED of 1ES 1011+496 could be fully characterized from 0.1 GeV to 1 TeV, which permitted a more reliable interpretation within the one-zone SSC scenario. The polarimetry data suggest that at least part of the optical emission has its origin in some of the bright radio features, while the low polarization in optical might be due to the contribution of parts of the radio jet with different orientations of the magnetic field with respect to the optical emission., Published by EDP Sciences, Les Ulis
Published: 2016
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24. Very High-Energy Gamma-Ray Follow-Up Program Using Neutrino Triggers from IceCube

Author: IceCube Collaboration, Aartsen, M. G., Abraham, K., Ackermann, M., Adams, J., Aguilar, J. A., Ahlers, M., Ahrens, M., Altmann, D., Andeen, K., Anderson, T., Ansseau, I., Anton, G., Archinger, M., Arguelles, C., Auffenberg, J., Axani, S., Bai, X., Barwick, S. W., Baum, V., Bay, R., Beatty, J. J., Becker-Tjus, J., Becker, K. -H., BenZvi, S., Berley, D., Bernardini, E., Bernhard, A., Besson, D. Z., Binder, G., Bindig, D., Bissok, M., Blaufuss, E., Blot, S., Bohm, C., Borner, M., Bos, F., Bose, D., Boser, S., Botner, O., Braun, J., Brayeur, L., Bretz, H. -P., Bron, S., Burgman, A., Carver, T., Casier, M., Cheung, E., Chirkin, D., Christov, A., Clark, K., Classen, L., Coenders, S., Collin, G. H., Conrad, J. M., Cross, D. F. Cowen R., Day, M., De Andre, J. P. A. M., De Clercq, C., Rosendo, E. Del Pino, Dembinski, H., De Ridder, S., Desiati, P., De Vries, K. D., De Wasseige, G., De With, M., DeYoung, T., Diaz-Velez, J. C., Di Lorenzo, V., Dujmovic, H., Dumm, J. P., Dunkman, M., Eberhardt, B., Ehrhardt, T., Eichmann, B., Eller, P., Euler, S., Evenson, P. A., Fahey, S., Fazely, A. R., Feintzeig, J., Felde, J., Filimonov, K., Finley, C., Flis, S., Fosig, C. -C., Franckowiak, A., Franke, R., Friedman, E., Fuchs, T., Gaisser, T. K., Gallagher, J., Gerhardt, L., Ghorbani, K., Giang, W., Gladstone, L., Glauch, T., Glusenkamp, T., Goldschmidt, A., Golup, G., Gonzalez, J. G., Grant, D., Griffith, Z., Haack, C., Ismail, A. Haj, Hallgren, A., Halzen, F., Hansen, E., Hansmann, T., Hanson, K., Hebecker, D., Heereman, D., Helbing, K., Hellauer, R., Hickford, S., Hignight, J., Hill, G. C., Hoffman, K. D., Hoffmann, Rainer, Holzapfel, K., Hoshina, K., Huang, F., Huber, M., Hultqvist, K., In, S., Ishihara, A., Jacobi, E., Japaridze, G. S., Jeong, M., Jero, K., Jones, B. J. P., Jurkovic, M., Kappes, A., Karg, T., Karle, A., Katz, U., Kauer, M., Keivani, A., Kelley, J. L., Kheirandish, A., Kim, M., Kintscher, T., Kiryluk, J., Kittler, T., Klein, S. R., Kohnen, G., Koirala, R., Kolanoski, H., Konietz, R., Kopke, L., Kopper, C., Kopper, S., Koskinen, D. J., Kowalski, M., Krings, K., Kroll, M., Kruckl, G., Kruger, C., Kunnen, J., Kunwar, S., Kurahashi, N., Kuwabara, T., Labare, M., Lanfranchi, J. L., Larson, M. J., Lauber, F., Lennarz, D., Lesiak-Bzdak, M., Leuermann, M., Lu, L., Lunemann, J., Madsen, J., Maggi, G., Mahn, K. B. M., Mancina, S., Mandelartz, M., Maruyama, R., Mase, K., Maunu, R., McNally, F., Meagher, K., Medici, M., Meier, M., Meli, A., Menne, T., Merino, G., Meures, T., Miarecki, S., Mohrmann, L., Montaruli, T., Moulai, M., Nahnhauer, R., Naumann, U., Neer, G., Niederhausen, H., Nowicki, S. C., Nygren, D. R., Pollmann, A. Obertacke, Olivas, A., O'Murchadha, A., Palczewski, T., Pandya, H., Pankova, D. V., Peiffer, P., Penek, O., Pepper, J. A., Heros, C. Perez De Los, Pieloth, D., Pinat, E., Price, P. B., Przybylski, G. T., Quinnan, M., Raab, C., Radel, L., Rameez, M., Rawlins, K., Reimann, R., Relethford, B., Relich, M., Resconi, E., Rhode, W., Richman, M., Riedel, B., Robertson, S., Rongen, M., Rott, C., Ruhe, T., Ryckbosch, D., Rysewyk, D., Sabbatini, L., Sanchez-Herrera, S. E., Sandrock, A., Sandroos, J., Sarkar, S., Satalecka, K., Schlunder, P., Schmidt, T., Schoenen, S., Schoneberg, S., Schumacher, L., Seckel, D., Seunarine, S., Soldin, D., Song, M., Spiczak, G. M., Spiering, C., Stanev, T., Stasik, A., Stettner, J., Steuer, A., Stezelberger, T., Stokstad, R. G., Stossl, A., Strom, R., Strotjohann, N. L., Sullivan, G. W., Sutherland, M., Taavola, H., Taboada, I., Tatar, J., Tenholt, F., Ter-Antonyan, S., Terliuk, A., Tevsic, G., Tilav, S., Toale, P. A., Tobin, M. N., Toscano, S., Tosi, D., Tselengidou, M., Turcati, A., Unger, E., Usner, M., Vandenbroucke, J., Van Eijndhoven, N., Vanheule, S., Van Rossem, M., Van Santen, J., Veenkamp, J., Vehring, M., Voge, M., Vogel, E., Vraeghe, M., Walck, C., Wallace, A., Wallraff, M., Wandkowsky, N., Weaver, Ch., Weiss, M. J., Wendt, C., Westerhoff, S., Whelan, B. J., Wickmann, S., Wiebe, K., Wiebusch, C. H., Wille, L., Williams, D. R., Wills, L., Wolf, M., Wood, T. R., Woolsey, E., Woschnagg, K., Xu, D. L., Xu, X. W., Xu, Y., Yanez, J. P., Yodh, G., Yoshida, S., M. Zoll MAGIC Collaboration, Ahnen, M. L., Ansoldi, S., Antonelli, L. A., Antoranz, P., Babic, A., Banerjee, B., Bangale, P., De Almeida, U. Barres, Barrio, J. A., Gonzalez, J. Becerra, Bednarek, W., Berti, A., Biasuzzi, B., Biland, A., Blanch, O., Bonnefoy, S., Bonnoli, G., Borracci, F., Bretz, T., Buson, S., Carosi, A., Chatterjee, A., Clavero, R., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Wilhelmi, E. De Ona, Di Pierro, F., Doert, M., Dominguez, A., Prester, D. Dominis, Dorner, D., Doro, M., Einecke, S., Glawion, D. Eisenacher, Elsaesser, D., Engelkemeier, M., Ramazani, V. Fallah, Fernandez-Barral, A., Fidalgo, D., Fonseca, M. V., Font, L., Frantzen, K., Fruck, C., Galindo, D., Lopez, R. J. Garcia, Garczarczyk, M., Terrats, D. Garrido, Gaug, M., Giammaria, P., Godinovic, N., Munoz, A. Gonzalez, Gora, D., Guberman, D., Hadasch, D., Hahn, A., Hanabata, Y., Hayashida, M., Herrera, J., Hose, J., Hrupec, D., Hughes, G., Idec, W., Kodani, K., Konno, Y., Kubo, H., Kushida, J., La Barbera, A., Lelas, D., Lindfors, E., Lombardi, S., Longo, F., Lopez, M., Lopez-Coto, R., Majumdar, P., Makariev, M., Mallot, K., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Marcote, B., Mariotti, M., Martinez, M., Mazin, D., Menzel, U., Miranda, J. M., Mirzoyan, R., Moralejo, A., Moretti, E., Nakajima, D., Neustroev, V., Niedzwiecki, A., Rosillo, M. Nievas, Nilsson, K., Nishijima, K., Noda, K., Nogues, L., Overkemping, A., Paiano, S., Palacio, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Paredes-Fortuny, X., Pedaletti, G., Peresano, M., Perri, L., Persic, M., Poutanen, J., Moroni, P. G. Prada, Prandini, E., Puljak, I., Reichardt, I., Ribo, M., Rico, J., Garcia, J. Rodriguez, Saito, T., Schroeder, S., Schultz, C., Schweizer, T., Sillanpaa, A., Sitarek, J., Snidaric, I., Sobczynska, D., Stamerra, A., Steinbring, T., Strzys, M., Suric, T., Takalo, L., Tavecchio, F., Temnikov, P., Terzic, T., Tescaro, D., Teshima, M., Thaele, J., Torres, D. F., Toyama, T., Treves, A., Vanzo, G., Verguilov, V., Vovk, I., Ward, J. E., Will, M., Wu, M. H., R. Zanin VERITAS Collaboration, Abeysekara, A. U., Archambault, S., Archer, A., Benbow, W., Bird, R., Bourbeau, E., Buchovecky, M., Bugaev, V., Byrum, K., Cardenzana, J. V, Cerruti, M., Ciupik, L., Connolly, M. P., Cui, W., Dickinson, H. J., Dumm, J., Eisch, J. D., Errando, M., Falcone, A., Feng, Q., Finley, J. P., Fleischhack, H., Flinders, A., Fortson, L., Furniss, A., Gillanders, G. H., Griffin, S., Grube, J., Hutten, M., Haakansson, N., Hervet, O., Holder, J., Humensky, T. B., Johnson, C. A., Kaaret, P., Kar, P., Kelley-Hoskins, N., Kertzman, M., Kieda, D., Krause, Maria, Krennrich, F., Kumar, S., Lang, M. J., Maier, G., McArthur, S., McCann, A., Moriarty, P., Mukherjee, R., Nguyen, T., Nieto, D., O'Brien, S., Ong, R. A., Otte, A. N., Park, N., Pohl, Martin, Popkow, A., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Richards, G. T., Roache, E., Rulten, C., Sadeh, I., Santander, M., Sembroski, G. H., Shahinyan, K., Staszak, D., Telezhinsky, I., Tucci, J. V., Tyler, J., Wakely, S. P., Weinstein, A., Wilcox, P., Wilhelm, A., Williams, D. A., and Zitzer, B.
Abstract: (2016)., We describe and report the status of a neutrino-triggered program in IceCube that generates real-time alerts for gamma-ray follow-up observations by atmospheric-Cherenkov telescopes (MAGIC and VERITAS). While IceCube is capable of monitoring the whole sky continuously, high-energy gamma-ray telescopes have restricted fields of view and in general are unlikely to be observing a potential neutrino-flaring source at the time such neutrinos are recorded. The use of neutrino-triggered alerts thus aims at increasing the availability of simultaneous multi-messenger data during potential neutrino flaring activity, which can increase the discovery potential and constrain the phenomenological interpretation of the high-energy emission of selected source classes (e.g. blazars). The requirements of a fast and stable online analysis of potential neutrino signals and its operation are presented, along with first results of the program operating between 14 March 2012 and 31 December 2015.
Published: 2016
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25. Long-term multi-wavelength variability and correlation study of Markarian 421 from 2007 to 2009

Author: Ahnen, M. L., Ansoldi, S., Antonelli, L. A., Antoranz, P., Babic, A., Banerjee, B., Bangale, P., Barres De Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bernardini, E., Biasuzzi, B., Biland, A., Blanch, O., Bonnefoy, S., Bonnoli, G., Borracci, F., Bretz, T., Buson, S., Carosi, A., Chatterjee, A., Clavero, R., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., De Oña Wilhelmi, E., Di Pierro, F., Domínguez, A., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Eisenacher Glawion, D., Elsaesser, D., Fernández-Barral, A., Fidalgo, D., Fonseca, M. V., Font, L., Frantzen, K., Fruck, C., Galindo, D., García López, R. J., Garczarczyk, M., Garrido Terrats, D., Gaug, M., Giammaria, P., Godinović, N., González Muñoz, A., Gora, D., Guberman, D., Hadasch, D., Hahn, A., Hanabata, Y., Hayashida, M., Herrera, J., Hose, J., Hrupec, D., Hughes, G., Idec, W., Kodani, K., Konno, Y., Kubo, H., Kushida, J., La Barbera, A., Lelas, D., Lindfors, E., Lombardi, S., Longo, F., López, M., López-Coto, R., Majumdar, P., Makariev, M., Mallot, K., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Marcote, B., Mariotti, M., Martínez, M., Mazin, D., Menzel, U., Miranda, J. M., Mirzoyan, R., Moralejo, A., Moretti, E., Nakajima, D., Neustroev, V., Niedzwiecki, A., Nievas Rosillo, M., Nilsson, K., Nishijima, K., Noda, K., Nogués, L., Orito, R., Overkemping, A., Paiano, S., Palacio, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Paredes-Fortuny, X., Pedaletti, G., Perri, L., Persic, M., Poutanen, J., Prada Moroni, P. G., Prandini, E., Puljak, I., Rhode, W., Ribó, M., Rico, J., Rodriguez Garcia, J., Saito, T., Satalecka, K., Schultz, C., Schweizer, T., Shore, S. N., Sillanpää, A., Sitarek, J., Snidaric, I., Sobczynska, D., Stamerra, A., Steinbring, T., Strzys, M., Takalo, L., Takami, H., Tavecchio, F., Temnikov, P., Terzić, T., Tescaro, D., Teshima, M., Thaele, J., Torres, D. F., Toyama, T., Treves, A., Verguilov, V., Vovk, I., Ward, J. E., Will, M., Wu, M. H., Zanin, R., Blinov, D. A., Chen, W. P., Efimova, N. V., Forné, E., Grishina, T. S., Hovatta, T., Jordan, B., Kimeridze, G. N., Kopatskaya, E. N., Koptelova, E., Kurtanidze, O. M., Kurtanidze, S. O., Lähteenmäki, A., Larionov, V. M., Larionova, E. G., Larionova, L. V., Ligustri, R., Lin, H. C., McBreen, B., Morozova, D. A., Nikolashvili, M. G., Raiteri, C. M., Ros, J. A., Sadun, A. C., Sigua, L. A., Tornikoski, M., Troitsky, I. S., and Villata, M.
Abstract: Astronomy and astrophysics 593, A91(2016). doi:10.1051/0004-6361/201628447, Aims. We study the multi-band variability and correlations of the TeV blazar Mrk 421 on year timescales, which can bring additional insight on the processes responsible for its broadband emission.Methods. We observed Mrk 421 in the very high energy (VHE) γ-ray range with the Cherenkov telescope MAGIC-I from March 2007 to June 2009 for a total of 96 h of effective time after quality cuts. The VHE flux variability is quantified using several methods, including the Bayesian Block algorithm, which is applied to data from Cherenkov telescopes here for the first time. The 2.3 yr long MAGIC light curve is complemented with data from the Swift/BAT and RXTE/ASM satellites and the KVA, GASP-WEBT, OVRO, and Metsähovi telescopes from February 2007 to July 2009, allowing for an excellent characterisation of the multi-band variability and correlations over year timescales.Results. Mrk 421 was found in different γ-ray emission states during the 2.3 yr long observation period: The flux above 400 GeV spans from the minimum nightly value of (1.3 ± 0.4) × 10$^{-11}$ cm$^{-2}$ s$^{-1}$ to the maximum flux, that is about 24 times higher, at (3.1 ± 0.1) × 10$^{-10}$ cm$^{-2}$ s$^{-1}$. Flares and different levels of variability in the γ-ray light curve could be identified with the Bayesian Block algorithm. The same behaviour of a quiet and active emission was found in the X-ray light curves measured by Swift/BAT and the RXTE/ASM, with a direct correlation in time. The behaviour of the optical light curve of GASP-WEBT and the radio light curves by OVRO and Metsähovi are different as they show no coincident features with the higher energetic light curves and a less variable emission. Overall, the fractional variability increases with energy. The comparable variability in the X-ray and VHE bands and their direct correlation during both high- and low-activity periods spanning many months show that the electron populations radiating the X-ray and γ-ray photons are either the same, as expected in the synchrotron-self-Compton mechanism, or at least strongly correlated, as expected in electromagnetic cascades., Published by EDP Sciences, Les Ulis
Published: 2016
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26. Discovery of very high Energy $\gamma$ -ray Emission from the Blazar 1ES 0033+595 by the MAGIC Telescopes

Author: Aleksi, J., Ansoldi, S., Antonelli, L. A., Antoranz, P., Babic, A., Bangale, P., De Almeida, U. B., Barrio, J. A., Gonzalez, J. B., Bednarek, W., Berger, K., Bernardini, E., Biland, A., Blanch, O., Bonnefoy, S., Bonnoli, G., Borracci, F., Bretz, T., Carmona, E., Carosi, A., Fidalgo, D. C., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Da Vela, P., Dazzi, F., De Angelis, A., De Caneva, G., De Lotto, B., Mendez, C. D., Doert, M., Dominguez, A., Prester, D. D., Dorner, D., Doro, M., Einecke, S., Eisenacher, D., Elsaesser, D., Farina, E., Ferenc, D., Fonseca, M. V., Font, L., Frantzen, K., Fruck, C., Lopez, R. J. G., Garczarczyk, M., Terrats, D. G., Gaug, M., Godinovi, N., Munoz, A. G., Gozzini, S. R., Hadasch, D., Hayashida, M., Herrera, J., Herrero, A., Hildebrand, D., Hose, J., Hrupec, D., Idec, W., Kadenius, V., Kellermann, H., Kodani, K., Konno, Y., Krause, J., Kubo, H., Kushida, J., Barbera, A. L., Lelas, D., Lewandowska, N., Lindfors, E., Lombardi, S., Lopez, M., Lopez-Coto, R., Lopez-Oramas, A., Lorenz, E., Lozano, I., Makariev, M., Mallot, K., Maneva, G., Mankuzhiyil, N., Mannheim, K., Maraschi, L., Marcote, B., Mariotti, M., Martinez, M., Mazin, D., Menzel, U., Meucci, M., Miranda, J. M., Mirzoyan, R., Moralejo, A., Munar-Adrover, P., Nakajima, D., Niedzwiecki, A., Nilsson, K., Nishijima, K., Noda, K., Nowak, N., Orito, R., Overkemping, A., Paiano, S., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Paredes-Fortuny, X., Partini, S., Persic, M., Prada, F., Moroni, P. G. P., Prandini, E., Preziuso, S., Puljak, I., Reinthal, R., Rhode, W., Ribo, M., Rico, J., Garcia, J. R., Rugamer, S., Saggion, A., Saito, T., Saito, K., Satalecka, K., Scalzotto, V., Scapin, V., Schultz, C., Schweizer, T., Shore, S. N., Sillanpaa, A., Sitarek, J., Snidaric, I., Sobczynska, D., Spanier, F., Stamatescu, V., Stamerra, A., Steinbring, T., Storz, J., Sun, S., Suri, T., Takalo, L., Takami, H., Tavecchio, F., Temnikov, P., Terzi, T., Tescaro, D., Teshima, M., Thaele, J., Tibolla, O., Torres, D. F., Toyama, T., Treves, A., Uellenbeck, M., Vogler, P., Wagner, R. M., Zandanel, F., Zanin, R., Collaboration), (MAGIC, Tronconi, V., Buson, S., and Borghese, A.
Abstract: Monthly notices of the Royal Astronomical Society 446(1), 217 - 225 (2015). doi:10.1093/mnras/stu2024, Published by Oxford Univ. Press, Oxford
Published: 2015
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27. Bounds on Lorentz invariance violation from MAGIC observation of GRB 190114C

Author: Acciari, V. A., Ansoldi, S., Antonelli, L. A., Arbet Engels, A., Baack, D., Babić, A., Banerjee, B., Barres de Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bellizzi, L., Bernardini, E., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Bošnjak, Ž., Busetto, G., Carosi, R., Ceribella, G., Cerruti, M., Chai, Y., Chilingarian, A., Cikota, S., Colak, S. M., Colin, U., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D'Amico, G., D'Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Depaoli, D., Di Pierro, F., Di Venere, L., Do Souto Espiñeira, E., Dominis Prester, D., Donini, A., Dorner, D., Doro, M., Elsaesser, D., Fallah Ramazani, V., Fattorini, A., Ferrara, G., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Fukami, S., García López, R. J., Garczarczyk, M., Gasparyan, S., Gaug, M., Giglietto, N., Giordano, F., Gliwny, P., Godinović, N., Green, D., Hadasch, D., Hahn, A., Herrera, J., Hoang, J., Hrupec, D., Hütten, M., Inada, T., Inoue, S., Ishio, K., Iwamura, Y., Jouvin, L., Kajiwara, Y., Karjalainen, M., Kerszberg, D., Kobayashi, Y., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., López, M., López-Coto, R., López-Oramas, A., Loporchio, S., Machado de Oliveira Fraga, B., Maggio, C., Majumdar, P., Makariev, M., Mallamaci, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Mazin, D., Mender, S., Mićanović, S., Miceli, D., Miener, T., Minev, M., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Morcuende, D., Moreno, V., Moretti, E., Munar-Adrover, P., Neustroev, V., Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Nozaki, S., Ohtani, Y., Oka, T., Otero-Santos, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Pavletić, L., Peñil, P., Perennes, C., Peresano, M., Persic, M., Prada Moroni, P. G., Prandini, E., Puljak, I., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Sahakyan, N., Saito, T., Sakurai, S., Satalecka, K., Schleicher, B., Schmidt, K., Schweizer, T., Sitarek, J., Šnidarić, I., Sobczynska, D., Spolon, A., Stamerra, A., Strom, D., Strzys, M., Suda, Y., Surić, T., Takahashi, M., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Torres-Albà, N., Tosti, L., van Scherpenberg, J., Vanzo, G., Vazquez Acosta, M., Ventura, S., Verguilov, V., Vigorito, C. F., Vitale, V., Vovk, I., Will, M., Zarić, D., and Nava, L.
Subjects: higher-order: 0, spectral, quantum gravity: model, Cherenkov counter: imaging, gamma ray: burst, invariance: Lorentz, 7. Clean energy, MAGIC, violation: Lorentz, photon: velocity, energy dependence
Abstract: Physical review letters 125(2), 1-7 (2020). doi:10.1103/PhysRevLett.125.021301, On January 14, 2019, the Major Atmospheric Gamma Imaging Cherenkov telescopes detected GRB 190114C above 0.2 TeV, recording the most energetic photons ever observed from a gamma-ray burst. We use this unique observation to probe an energy dependence of the speed of light in vacuo for photons as predicted by several quantum gravity models. Based on a set of assumptions on the possible intrinsic spectral and temporal evolution, we obtain competitive lower limits on the quadratic leading order of speed of light modification., Published by APS, College Park, Md.

28. Testing two-component models on very-high-energy gamma-ray emitting BL Lac objects

Author: Acciari, V. A., Ansoldi, S., Antonelli, L. A., Arbet Engels, A., Baack, D., Babić, A., Banerjee, B., Barres De Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bellizzi, L., Bernardini, E., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Bošnjak, Z., Busetto, G., Carosi, R., Ceribella, G., Cerruti, M., Chai, Y., Chilingarian, A., Cikota, S., Colak, S. M., Colin, U., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D'Amico, G., D'Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Depaoli, D., Di Pierro, F., Di Venere, L., Do Souto Espiñeira, E., Dominis Prester, D., Donini, A., Dorner, D., Doro, M., Elsaesser, D., Fallah Ramazani, V., Fattorini, A., Ferrara, G., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Fukami, S., García López, R. J., Garczarczyk, Markus, Gasparyan, S., Gaug, M., Giglietto, N., Giordano, F., Gliwny, P., Godinović, N., Green, D., Hadasch, D., Hahn, A., Herrera, J., Hoang, J., Hrupec, D., Hütten, M., Inada, T., Inoue, S., Ishio, K., Iwamura, Y., Jouvin, L., Kajiwara, Y., Karjalainen, M., Kerszberg, D., Kobayashi, Y., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., López, M., López-Coto, R., López-Oramas, A., Loporchio, S., Machado De Oliveira Fraga, B., Maggio, C., Majumdar, P., Makariev, M., Mallamaci, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Mazin, D., Mender, S., Mićanović, S., Miceli, D., Miener, T., Minev, M., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Morcuende, D., Moreno, V., Moretti, E., Munar-Adrover, P., Neustroev, V., Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Nozaki, S., Ohtani, Y., Oka, T., Otero-Santos, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Pavletić, L., Peñil, P., Peresano, M., Persic, M., Prada Moroni, P. G., Prandini, E., Puljak, I., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Sahakyan, N., Saito, T., Sakurai, S., Satalecka, K., Schleicher, B., Schmidt, K., Schweizer, T., Sitarek, J., Šnidarić, I., Sobczynska, D., Spolon, A., Stamerra, A., Strom, D., Strzys, M., Suda, Y., Surić, T., Takahashi, M., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Torres-Albà, N., Tosti, L., Van Scherpenberg, J., Vanzo, G., Vazquez Acosta, M., Ventura, S., Verguilov, V., Vigorito, C. F., Vitale, V., Vovk, I., Will, M., Zarić, D., Nievas-Rosillo, M., Arcaro, C., D' Ammando, F., De Palma, F., Hodges, M., Hovatta, T., Kiehlmann, S., Max-Moerbeck, W., Readhead, A. C. S., Reeves, R., Takalo, L., Reinthal, R., Jormanainen, J., Wierda, F., Wagner, S. M., Berdyugin, A., Nabizadeh, A., Talebpour Sheshvan, N., Oksanen, A., Bachev, R., Strigachev, A., and Kehusmaa, P.
Subjects: 7. Clean energy
Abstract: Astronomy and astrophysics 640, A132 - (2020). doi:10.1051/0004-6361/202037811, Context. It has become evident that one-zone synchrotron self-Compton models are not always adequate for very-high-energy (VHE) gamma-ray emitting blazars. While two-component models are performing better, they are difficult to constrain due to the large number of free parameters. Aims. In this work, we make a first attempt to take into account the observational constraints from Very Long Baseline Interferometry (VLBI) data, long-term light curves (radio, optical, and X-rays) and optical polarisation to limit the parameter space for a two-component model and test if it can still reproduce the observed spectral energy distribution (SED) of the blazars. Methods. We selected five TeV BL Lac objects based on the availability of VHE gamma-ray and optical polarisation data. We collected constraints for the jet parameters from VLBI observations. We evaluated the contributions of the two components to the optical flux by means of decomposition of long-term radio and optical light curves as well as modeling of the optical polarisation variability of the objects. We selected eight epochs for these five objects, based on the variability observed at VHE gamma rays, for which we constructed the SEDs that we then modeled with a two-component model. Results. We found parameter sets which can reproduce the broadband SED of the sources in the framework of two-component models considering all available observational constraints from VLBI observations. Moreover, the constraints obtained from the long-term behavior of the sources in the lower energy bands could be used to determine the region where the emission in each band originates. Finally, we attempted to use optical polarisation data to shed new light on the behavior of the two components in the optical band. Our observationally constrained two zone model allows explanation of the entire SED from radio to VHE with two co-located emission regions., Published by EDP Sciences, Les Ulis

29. Investigation of the correlation patterns and the Compton dominance variability of Mrk 421 in 2017

Author: Acciari, V. A., Ansoldi, S., Antonelli, L. A., Engels, A. Arbet, Artero, M., Asano, K., Babi��, A., Baquero, A., de Almeida, U. Barres, Barrio, J. A., Batkovi��, I., Gonz��lez, J. Becerra, Bednarek, W., Bellizzi, L., Bernardini, E., Bernardos, M., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Blanch, O., Bo��njak, Z., Busetto, G., Carosi, R., Ceribella, G., Cerruti, M., Chai, Y., Chilingarian, A., Cikota, S., Colak, S. M., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D'Amico, G., D'Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Mendez, C. Delgado, Depaoli, D., Di Pierro, F., Di Venere, L., Do Souto Espi��eira, E., Prester, D. Dominis, Donini, A., Doro, M., Ramazani, V. Fallah, Fattorini, A., Ferrara, G., Fonseca, M. V., Font, L., Fruck, C., Fukami, S., L��pez, R. J. Garc��a, Garczarczyk, Markus, Gasparyan, S., Gaug, M., Giglietto, N., Giordano, F., Gliwny, P., Godinovi��, N., Green, J. G., Green, D., Hadasch, D., Hahn, A., Heckmann, L., Herrera, J., Hoang, J., Hrupec, D., H��tten, M., Inada, T., Inoue, S., Ishio, K., Iwamura, Y., Jim��nez, I., Jormanainen, J., Jouvin, L., Kajiwara, Y., Karjalainen, M., Kerszberg, D., Kobayashi, Y., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., L��pez-Coto, R., L��pez-Moya, M., L��pez-Oramas, A., Loporchio, S., de Oliveira Fraga, B. Machado, Maggio, C., Majumdar, P., Makariev, M., Mallamaci, M., Maneva, G., Manganaro, M., Maraschi, L., Mariotti, M., Mart��nez, M., Mazin, D., Menchiari, S., Mender, S., Mi��anovi��, S., Miceli, D., Miener, T., Minev, M., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Morcuende, D., Moreno, V., Moretti, E., Neustroev, V., Nigro, C., Nilsson, K., Nishijima, K., Noda, K., Nozaki, S., Ohtani, Y., Oka, T., Otero-Santos, J., Paiano, S., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Pavleti��, L., Pe��il, P., Perennes, C., Persic, M., Moroni, P. G. Prada, Prandini, E., Priyadarshi, C., Puljak, I., Rib��, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Sahakyan, N., Saito, T., Sakurai, S., Satalecka, K., Saturni, F. G., Schmidt, K., Schweizer, T., Sitarek, J., ��nidari��, I., Sobczynska, D., Spolon, A., Stamerra, A., Strom, D., Strzys, M., Suda, Y., Suri��, T., Takahashi, M., Tavecchio, F., Temnikov, P., Terzi��, T., Teshima, M., Tosti, L., Truzzi, S., Tutone, A., Ubach, S., van Scherpenberg, J., Vanzo, G., Acosta, M. Vazquez, Ventura, S., Verguilov, V., Vigorito, C. F., Vitale, V., Vovk, I., Will, M., Wunderlich, C., Zari��, D., Baack, D., Balbo, M., Biederbeck, N., Biland, A., Bretz, T., Buss, J., Dorner, D., Eisenberger, L., Elsaesser, D., Hildebrand, D., Iotov, R., Mannheim, K., Neise, D., Noethe, M., Paravac, A., Rhode, W., Schleicher, B., Sliusar, V., Walter, R., D'Ammando, F., Horan, D., Lien, A. Y., Balokovi��, M., Madejski, G. M., Perri, M., Verrecchia, F., Leto, C., L��hteenm��ki, A., Tornikoski, M., Ramakrishnan, V., J��rvel��, E., Vera, R. J. C., Chamani, W., Villata, M., Raiteri, C. M., Gupta, A. C., Pandey, A., Fuentes, A., Agudo, I., Casadio, C., Semkov, E., Ibryamov, S., Marchini, A., Bachev, R., Strigachev, A., Ovcharov, E., Bozhilov, V., Valcheva, A., Zaharieva, E., Damljanovic, G., Vince, O., Larionov, V. M., Borman, G. A., Grishina, T. S., Hagen-Thorn, V. A., Kopatskaya, E. N., Larionova, E. G., Larionova, L. V., Morozova, D. A., Nikiforova, A. A., Savchenko, S. S., Troitskiy, I. S., Troitskaya, Y. V., Vasilyev, A. A., Merkulova, O. A., Chen, W. P., Samal, M., Lin, H. C., Moody, J. W., Sadun, A. C., Jorstad, S. G., Marscher, A. P., Weaver, Z. R., Feige, M., Kania, J., Kopp, M., Kunkel, L., Reinhart, D., Scherbantin, A., Schneider, L., Lorey, C., Acosta-Pulido, J. A., Carnerero, M. I., Carosati, D., Kurtanidze, S. O., Kurtanidze, O. M., Nikolashvili, M. G., Chanishvili, R. G., Chigladze, R. A., Ivanidze, R. Z., Kimeridze, G. N., Sigua, L. A., Joner, M. D., Spencer, M., Giroletti, M., Marchili, N., Righini, S., Rizzi, N., and Bonnoli, G.
Subjects: electron, galaxies: active, flux: correlation, GeV, radiation mechanisms: non-thermal, 7. Clean energy, MAGIC, GLAST, blazar, gamma ray: VHE, ultraviolet, optical, spectral, TeV, BL Lacertae objects: individual: Mrk 421, X-ray: flux, model: leptonic, Lorentz
Abstract: Astronomy and astrophysics 655, A89 (2021). doi:10.1051/0004-6361/202141004, Aims. We present a detailed characterisation and theoretical interpretation of the broadband emission of the paradigmatic TeV blazar Mrk 421, with a special focus on the multi-band flux correlations.Methods. The dataset has been collected through an extensive multi-wavelength campaign organised between 2016 December and 2017 June. The instruments involved are MAGIC, FACT, Fermi-LAT, Swift, GASP-WEBT, OVRO, Medicina, and Mets��hovi. Additionally, four deep exposures (several hours long) with simultaneous MAGIC and NuSTAR observations allowed a precise measurement of the falling segments of the two spectral components.Results. The very-high-energy (VHE; E > 100 GeV) gamma rays and X-rays are positively correlated at zero time lag, but the strength and characteristics of the correlation change substantially across the various energy bands probed. The VHE versus X-ray fluxes follow different patterns, partly due to substantial changes in the Compton dominance for a few days without a simultaneous increase in the X-ray flux (i.e., orphan gamma-ray activity). Studying the broadband spectral energy distribution (SED) during the days including NuSTAR observations, we show that these changes can be explained within a one-zone leptonic model with a blob that increases its size over time. The peak frequency of the synchrotron bump varies by two orders of magnitude throughout the campaign. Our multi-band correlation study also hints at an anti-correlation between UV-optical and X-ray at a significance higher than 3��. A VHE flare observed on MJD 57788 (2017 February 4) shows gamma-ray variability on multi-hour timescales, with a factor ten increase in the TeV flux but only a moderate increase in the keV flux. The related broadband SED is better described by a two-zone leptonic scenario rather than by a one-zone scenario. We find that the flare can be produced by the appearance of a compact second blob populated by high energetic electrons spanning a narrow range of Lorentz factors, from ��$_{min}$=2��10$^4$ to ��$_{max}$=6��10$^5$.Key words: galaxies: active / BL Lacertae objects: individual: Mrk 421 / radiation mechanisms: non-thermal�� Light curves and spectral energy distributions data are only 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/cat/J/A+A/655/A89�� Corresponding authors: A. Arbet Engels and D. Paneque; e-mail: contact.magic@mpp.mpg.de.�� Also member of the MAGIC Collaboration.�� Also member of the FACT Collaboration., Published by EDP Sciences, Les Ulis

30. Discovery of TeV γ-ray emission from the neighbourhood of the supernova remnant G24.7+0.6 by MAGIC

Author: Acciari, V. A., Ansoldi, S., Antonelli, L. A., Arbet Engels, A., Arcaro, C., Baack, D., Babić, A., Banerjee, B., Bangale, P., De Almeida, U Barres, Barrio, J. A., Becerra González, J., Bednarek, W., Bernardini, E., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Carosi, R., Ceribella, G., Chatterjee, A., Colak, S. M., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Cumani, P., D’Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Di Pierro, F., Domínguez, A., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Elsaesser, D., Fallah Ramazani, V., Fattorini, A., Fernández-Barral, A., Ferrara, G., Fidalgo, D., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., Gallozzi, S., García López, R. J., Garczarczyk, M., Gaug, M., Giammaria, P., Godinović, N., Guberman, D., Hadasch, D., Hahn, A., Hassan, T., Herrera, J., Hoang, J., Hrupec, D., Inoue, S., Ishio, K., Iwamura, Y., Kubo, H., Kushida, J., Kuveždić, D., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., López, M., López-Oramas, A., Maggio, C., Majumdar, P., Makariev, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Masuda, S., Mazin, D., Minev, M., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Moreno, V., Moretti, E., Neustroev, V., Niedzwiecki, A., Nievas Rosillo, M., Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Paiano, S., Palacio, J., Paneque, D., Paoletti, R., Paredes, J. M., Pedaletti, Giovanna, Peñil, P., Peresano, M., Persic, M., Prada Moroni, P. G., Prandini, E., Puljak, I., Garcia, J. R., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Saito, T., Satalecka, K., Schweizer, T., Sitarek, J., Šnidarić, I., Sobczynska, D., Somero, A., Stamerra, A., Strzys, M., Surić, T., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Torres-Albà, N., Tsujimoto, S., Vanzo, G., Vazquez Acosta, M., Vovk, I., Ward, J. E., Will, M., Zarić, D., De Oña Wilhelmi, E., Torres, D. F., and Zanin, R.
Subjects: 13. Climate action
Abstract: Monthly notices of the Royal Astronomical Society 483(4), 4578 - 4585 (2019). doi:10.1093/mnras/sty3387, SNR G24.7+0.6 is a 9.5 kyrs radio and γ-ray supernova remnant evolving in a dense medium. In the GeV regime, SNR G24.7+0.6 (3FHL J1834.1–0706e/FGES J1834.1–0706) shows a hard spectral index (Γ ∼ 2) up to 200 GeV, which makes it a good candidate to be observed with Cherenkov telescopes such as MAGIC. We observed the field of view of SNR G24.7+0.6 with the MAGIC telescopes for a total of 31 h. We detect very high-energy γ-ray emission from an extended source located 0.34° away from the centre of the radio SNR. The new source, named MAGIC J1835–069 is detected up to 5 TeV, and its spectrum is well-represented by a power-law function with spectral index of 2.74 ± 0.08. The complexity of the region makes the identification of the origin of the very high-energy emission difficult; however, the spectral agreement with the LAT source and overlapping position at less than 1.5σ point to a common origin. We analysed 8 yr of Fermi-LAT data to extend the spectrum of the source down to 60 MeV. Fermi-LAT and MAGIC spectra overlap within errors and the global broad-band spectrum is described by a power law with exponential cut-off at 1.9 ± 0.5 TeV. The detected γ-ray emission can be interpreted as the results of proton–proton interaction between the supernova and the CO-rich surrounding., Published by Oxford Univ. Press, Oxford

31. Deep observations of the globular cluster M15 with the MAGIC telescopes

Author: Acciari, V. A., Ansoldi, S., Antonelli, L. A., Arbet Engels, A., Baack, D., Babić, A., Banerjee, B., Barres De Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bernardini, E., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Busetto, G., Carosi, R., Ceribella, G., Cikota, S., Colak, S. M., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D’Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Di Pierro, F., Do Souto Espiñera, E., Domínguez, A., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Elsaesser, D., Fallah Ramazani, V., Fattorini, A., Fernández-Barral, A., Ferrara, G., Fidalgo, D., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., Gallozzi, S., García López, R. J., Garczarczyk, M., Gasparyan, S., Gaug, M., Giammaria, P., Godinović, N., Green, D., Guberman, D., Hadasch, D., Hahn, A., Herrera, J., Hoang, J., Hrupec, D., Inoue, S., Ishio, K., Iwamura, Y., Kubo, H., Kushida, J., Kuveždić, D., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., López, M., López-Oramas, A., Machado De Oliveira Fraga, B., Maggio, C., Majumdar, P., Makariev, M., Mallamaci, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Masuda, S., Mazin, D., Minev, M., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Moreno, V., Moretti, E., Munar-Adrover, P., Neustroev, V., Niedzwiecki, A., Nievas Rosillo, M., Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Nöthe, M., Paiano, S., Palacio, J., Paneque, D., Paoletti, R., Paredes, J. M., Pedaletti, G., Peñil, P., Peresano, M., Persic, M., Prada Moroni, P. G., Prandini, E., Puljak, I., Garcia, J. R., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Sahakyan, N., Saito, T., Satalecka, K., Schweizer, T., Sitarek, J., Šnidarić, I., Sobczynska, D., Somero, A., Stamerra, A., Strzys, M., Surić, T., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Torres-Albà, N., Tsujimoto, S., Van Scherpenberg, J., Vanzo, G., Vazquez Acosta, M., Vovk, I., Will, M., and Zarić, D.
Subjects: 7. Clean energy
Abstract: Monthly notices of the Royal Astronomical Society 484(2), 2876 - 2885 (2019). doi:10.1093/mnras/stz179, A population of globular clusters (GCs) has been recently established by the Fermi-LAT telescope as a new class of GeV γ-ray sources. Leptons accelerated to TeV energies, in the inner magnetospheres of MSPs or in their wind regions, should produce γ-rays through the inverse Compton scattering in the dense radiation field from the huge population of stars. We have conducted deep observations of the GC M15 with the MAGIC telescopes and used 165 h in order to search for γ-ray emission. A strong upper limit on the TeV γ-ray flux $< 3.2 × 10^{−13}cm^{−2}s^{−1}$ above 300 GeV (⁠, Published by Oxford Univ. Press, Oxford

32. Discovery of very high energy gamma-ray emission from the blazar 1ES 1727+502 with the MAGIC Telescopes

Author: Aleksić, J., Antonelli, L. A., Antoranz, P., Asensio, M., Backes, M., Barres De Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Berger, K., Bernardini, E., Biland, A., Blanch, O., Bock, R. K., Boller, A., Bonnefoy, S., Bonnoli, G., Borla Tridon, D., Borracci, F., Bretz, T., Carmona, E., Carosi, A., Carreto Fidalgo, D., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Cossio, L., Covino, S., Da Vela, P., Dazzi, F., De Angelis, A., De Caneva, G., De Lotto, B., Delgado Mendez, C., Doert, M., Domínguez, A., Dominis Prester, D., Dorner, D., Doro, M., Eisenacher, D., Elsaesser, D., Farina, E., Ferenc, D., Fonseca, M. V., Font, L., Fruck, C., García López, R. J., Garczarczyk, M., Garrido Terrats, D., Gaug, M., Giavitto, G., Godinović, N., González Muñoz, A., Gozzini, S. R., Hadamek, A., Hadasch, D., Häfner, D., Herrero, A., Hose, J., Hrupec, D., Idec, W., Jankowski, F., Kadenius, V., Klepser, S., Knoetig, M. L., Krähenbühl, T., Krause, J., Kushida, J., La Barbera, A., Lelas, D., Lewandowska, N., Lindfors, E., Lombardi, S., López, M., López-Coto, R., López-Oramas, A., Lorenz, E., Lozano, I., Makariev, M., Mallot, K., Maneva, G., Mankuzhiyil, N., Mannheim, K., Maraschi, L., Marcote, B., Mariotti, M., Martínez, M., Masbou, J., Mazin, D., Meucci, M., Miranda, J. M., Mirzoyan, R., Moldón, J., Moralejo, A., Munar-Adrover, P., Nakajima, D., Niedzwiecki, A., Nilsson, K., Nowak, N., Orito, R., Paiano, S., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Partini, S., Persic, M., Prada, F., Prada Moroni, P. G., Prandini, E., Puljak, I., Reichardt, I., Reinthal, R., Rhode, W., Ribó, M., Rico, J., Rügamer, S., Saggion, A., Saito, K., Saito, T. Y., Salvati, M., Satalecka, K., Scalzotto, V., Scapin, V., Schultz, C., Schweizer, T., Shore, S. N., Sillanpää, A., Sitarek, J., Snidaric, I., Sobczynska, D., Spanier, F., Spiro, S., Stamatescu, V., Stamerra, A., Steinke, B., Storz, J., Sun, S., Surić, T., Takalo, L., Takami, H., Tavecchio, F., Temnikov, P., Terzić, T., Tescaro, D., Teshima, M., Tibolla, O., Torres, D. F., Toyama, T., Treves, A., Uellenbeck, M., Vogler, P., Wagner, R. M., Weitzel, Q., Zandanel, F., Zanin, R., and Buson, S.
Subjects: 13. Climate action, 7. Clean energy
Abstract: Astronomy and astrophysics 563, A90 (2014). doi:10.1051/0004-6361/201321360, Motivated by the prediction of a high TeV luminosity we investigated whether the blazar 1ES 1727+502 (z = 0.055) is emitting very high energy (VHE, E > 100 GeV) γ rays. We observed the BL Lac object 1ES 1727+502 in stereoscopic mode with the two MAGIC telescopes for 14 nights between May 6th and June 10th 2011, for a total effective observing time of 12.6 h. To study the multiwavelength spectral energy distribution (SED), we used simultaneous optical R-band data from the KVA telescope, archival UV/optical and X-ray observations from instruments UVOT and XRT on board of the Swift satellite, and high energy (HE, 0.1 GeV–100 GeV) γ-ray data from the Fermi-LAT instrument. We detected, for the first time, VHE γ-ray emission from 1ES 1727+502 at a statistical significance of 5.5σ. The integral flux above 150 GeV is estimated to be (2.1 ± 0.4)% of the Crab nebula flux and the de-absorbed VHE spectrum has a photon index of (2.7 ± 0.5). No significant short-term variability was found in any of the wavebands presented here. We model the SED using a one-zone synchrotron self-Compton model obtaining parameters typical for this class of sources., Published by EDP Sciences, Les Ulis

33. First detection of VHE gamma-ray emission from TXS 1515��273, study of its X-ray variability and spectral energy distribution

Author: Acciari, V. A., Ansoldi, S., Antonelli, L. A., Engels, A. Arbet, Artero, M., Asano, K., Baack, D., Babi��, A., Baquero, A., de Almeida, U. Barres, Barrio, J. A., Batkovi��, I., Gonz��lez, J. Becerra, Bednarek, W., Bellizzi, L., Bernardini, E., Bernardos, M., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bo��njak, ��., Busetto, G., Carosi, R., Ceribella, G., Cerruti, M., Chai, Y., Chilingarian, A., Cikota, S., Colak, S. M., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D'Amico, G., D'Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Mendez, C. Delgado, Depaoli, D., Di Pierro, F., Di Venere, L., Espi��eira, E. Do Souto, Prester, D. Dominis, Donini, A., Dorner, D., Doro, M., Elsaesser, D., Ramazani, V. Fallah, Fattorini, A., Ferrara, G., Fonseca, M. V., Font, L., Fruck, C., Fukami, S., L��pez, R. J. Garc��a, Garczarczyk, Markus, Gasparyan, S., Gaug, M., Giglietto, N., Giordano, F., Gliwny, P., Godinovi��, N., Green, J. G., Green, D., Hadasch, D., Hahn, A., Heckmann, L., Herrera, J., Hoang, J., Hrupec, D., H��tten, M., Inada, T., Inoue, S., Ishio, K., Iwamura, Y., Jim��nez, I., Jormanainen, J., Jouvin, L., Kajiwara, Y., Karjalainen, M., Kerszberg, D., Kobayashi, Y., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., L��pez-Coto, R., L��pez-Moya, M., L��pez-Oramas, A., Loporchio, S., Fraga, B. Machado de Oliveira, Maggio, C., Majumdar, P., Makariev, M., Mallamaci, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Mart��nez, M., Mazin, D., Menchiari, S., Mender, S., Mi��anovi��, S., Miceli, D., Miener, T., Minev, M., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Morcuende, D., Moreno, V., Moretti, E., Neustroev, V., Nigro, C., Nilsson, K., Nishijima, K., Noda, K., Nozaki, S., Ohtani, Y., Oka, T., Otero-Santos, J., Paiano, S., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Pavleti��, L., Pe��il, P., Perennes, C., Persic, M., Moroni, P. G. Prada, Prandini, E., Priyadarshi, C., Puljak, I., Rhode, W., Rib��, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Sahakyan, N., Saito, T., Sakurai, S., Satalecka, K., Saturni, F. G., Schleicher, B., Schmidt, K., Schweizer, T., Sitarek, J., ��nidari��, I., Sobczynska, D., Spolon, A., Stamerra, A., Strom, D., Strzys, M., Suda, Y., Suri��, T., Takahashi, M., Tavecchio, F., Temnikov, P., Terzi��, T., Teshima, M., Tosti, L., Truzzi, S., Tutone, A., Ubach, S., van Scherpenberg, J., Vanzo, G., Acosta, M. Vazquez, Ventura, S., Verguilov, V., Vigorito, C. F., Vitale, V., Vovk, I., Will, M., Wunderlich, C., Zaric, D., Bissaldi, E., Bonnoli, G., Cutini, S., D'Ammando, F., Nabizadeh, A., Marchini, A., and Orienti, M.
Subjects: Radiation mechanisms: non-thermal, objects: individual: TXS 1515��273, galaxies: active, 7. Clean energy
Abstract: Monthly notices of the Royal Astronomical Society 507(1), 1528 - 1545 (2021). doi:10.1093/mnras/stab1994, We report here on the first multiwavelength (MWL) campaign on the blazar TXS 1515��273, undertaken in 2019 and extending from radio to very-high-energy gamma-rays (VHE). Up until now, this blazar had not been the subject of any detailed MWL observations. It has a rather hard photon index at GeV energies and was considered a candidate extreme high-synchrotron-peaked source. MAGIC observations resulted in the first-time detection of the source in VHE with a statistical significance of 7.6��. The average integral VHE flux of the source is 6 �� 1 per cent of the Crab nebula flux above 400 GeV. X-ray coverage was provided by Swift-XRT, XMM��Newton, and NuSTAR. The long continuous X-ray observations were separated by ��9 h, both showing clear hour scale flares. In the XMM��Newton data, both the rise and decay time-scales are longer in the soft X-ray than in the hard X-ray band, indicating the presence of a particle cooling regime. The X-ray variability time-scales were used to constrain the size of the emission region and the strength of the magnetic field. The data allowed us to determine the synchrotron peak frequency and classify the source as a flaring high, but not extreme synchrotron-peaked object. Considering the constraints and variability patterns from the X-ray data, we model the broad-band spectral energy distribution. We applied a simple one-zone model, which could not reproduce the radio emission and the shape of the optical emission, and a two-component leptonic model with two interacting components, enabling us to reproduce the emission from radio to VHE band., Published by Oxford Univ. Press, Oxford

34. Gamma-ray flaring activity of NGC 1275 in 2016-2017 measured by MAGIC

Author: Ansoldi, S., Antonelli, L. A., Arcaro, C., Baack, D., Babić, A., Banerjee, B., Bangale, P., De Almeida, U. Barres, Barrio, J. A., González, J. Becerra, Bednarek, W., Bernardini, E., Berse, R. Ch., Berti, A., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Carosi, R., Ceribella, G., Chatterjee, A., Colak, S. M., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Cumani, P., D'Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Di Pierro, F., Domínguez, A., Prester, D. Dominis, Dorner, D., Doro, M., Einecke, S., Elsaesser, D., Ramazani, V. Fallah, Fattorini, A., Fernández-Barral, A., Ferrara, G., Fidalgo, D., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., Gallozzi, S., López, R. J. García, Garczarczyk, M., Gaug, M., Giammaria, P., Godinović, N., Gora, D., Guberman, D., Hadasch, D., Hahn, A., Hassan, T., Hayashida, M., Herrera, J., Hoang, J., Hose, J., Hrupec, D., Ishio, K., Konno, Y., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., López, M., Maggio, C., Majumdar, P., Makariev, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Masuda, S., Mazin, D., Mielke, K., Minev, M., Miranda, J. M., Mirzoyan, R., Moralejo, A., Moreno, V., Moretti, E., Nagayoshi, T., Neustroev, V., Niedzwiecki, A., Rosillo, M. Nievas, Nigro, Cosimo, Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Paiano, S., Palacio, J., Paneque, D., Paoletti, R., Paredes, J. M., Pedaletti, G., Peñil, P., Peresano, M., Persic, M., Pfrang, Konstantin Johannes, Moroni, P. G. Prada, Prandini, E., Puljak, I., Garcia, J. R., Reichardt, I., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Saito, T., Satalecka, K., Schweizer, T., Sitarek, J., Šnidarić, I., Sobczynska, D., Stamerra, A., Strzys, M., Surić, T., Takahashi, M., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Torres-Albà, N., Tsujimoto, S., Vanzo, G., Acosta, M. Vazquez, Vovk, I., Ward, J. E., Will, M., Zarić, D., Glawion, D., Takalo, L. O., and Jormanainen, J.
Subjects: 13. Climate action
Abstract: Astronomy and astrophysics 617, A91 (2018). doi:10.1051/0004-6361/201832895, We report on the detection of flaring activity from the Fanaroff-Riley I radio galaxy NGC 1275 in very-high-energy (VHE, E $>$ 100 GeV) gamma rays with the MAGIC telescopes. Observations were performed between 2016 September and 2017 February as part of a monitoring program. The brightest outburst with $\sim1.5$ times the Crab Nebula flux above 100 GeV (C.U.) was observed during the night between 2016 December 31 and 2017 January 1 (fifty times higher than the mean previously measured in two observational campaigns between 2009 and 2011). Significant variability of the day-by-day light curve was measured, the shortest flux-doubling time-scales was found to be of $(611\pm101)$ min. The combined spectrum of the MAGIC data during the strongest flare state and simultaneous data from the Fermi-LAT around 2017 January 1 follows a power-law with an exponential cutoff at the energy $(492\pm35)$ GeV. Simultaneous optical flux density measurements in the R-band obtained with the KVA telescope are also presented and the correlation between the optical and gamma-ray emission is investigated. Due to possible internal pair-production, the fast flux variability constrains the Doppler factor to values which are inconsistent with a large viewing angle as observed in the radio band. We investigate different scenarios for the explanation of fast gamma-ray variability, namely emission from: magnetospheric gaps, relativistic blobs propagating in the jet (mini-jets) or external cloud (or star) entering the jet. We find that the only plausible model to account for the luminosities here observed would be the production of gamma rays in a magnetospheric gap around the central black hole only in the eventuality of an enhancement of the magnetic field threading the hole from its equipartition value with the gas pressure in the accretion flow., Published by EDP Sciences, Les Ulis

35. Unravelling the complex behavior of Mrk 421 with simultaneous X-ray and VHE observations during an extreme flaring activity in April 2013

Author: Acciari, V. A., Ansoldi, S., Antonelli, L. A., Arbet Engels, A., Baack, D., Babić, A., Banerjee, B., Barres De Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bellizzi, L., Bernardini, E., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Bošnjak, Ž., Busetto, G., Carosi, R., Ceribella, G., Cerruti, M., Chai, Y., Chilingarian, A., Cikota, S., Colak, S. M., Colin, U., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D'Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Del Puppo, F., Delfino, M., Delgado, J., Depaoli, D., Di Pierro, F., Di Venere, L., Do Souto Espiñeira, E., Dominis Prester, D., Donini, A., Dorner, D., Doro, M., Elsaesser, D., Fallah Ramazani, V., Fattorini, A., Ferrara, G., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Fukami, S., García López, R. J., Garczarczyk, Markus, Gasparyan, S., Gaug, M., Giglietto, N., Giordano, F., Gliwny, P., Godinović, N., Green, D., Hadasch, D., Hahn, A., Herrera, J., Hoang, J., Hrupec, D., Hütten, M., Inada, T., Inoue, S., Ishio, K., Iwamura, Y., Jouvin, L., Kajiwara, Y., Kerszberg, D., Kobayashi, Y., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., López, M., López-Coto, R., López-Oramas, A., Loporchio, S., Machado De Oliveira Fraga, B., Maggio, C., Majumdar, P., Makariev, M., Mallamaci, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Mazin, D., Mender, S., Mićanović, S., Miceli, D., Miener, T., Minev, M., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Morcuende, D., Moreno, V., Moretti, E., Munar-Adrover, P., Neustroev, V., Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Nozaki, S., Ohtani, Y., Oka, T., Otero-Santos, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Pavletić, L., Peñil, P., Peresano, M., Persic, M., Prada Moroni, P. G., Prandini, E., Puljak, I., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Sahakyan, N., Saito, T., Sakurai, S., Satalecka, K., Schleicher, B., Schmidt, K., Schweizer, T., Sitarek, J., Šnidarić, I., Sobczynska, D., Spolon, A., Stamerra, A., Strom, D., Strzys, M., Suda, Y., Surić, T., Takahashi, M., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Torres-Albà, N., Tosti, L., Van Scherpenberg, J., Vanzo, G., Vazquez Acosta, M., Ventura, S., Verguilov, V., Vigorito, C. F., Vitale, V., Vovk, I., Will, M., Zarić, D., Petropoulou, M., Finke, J., D'Ammando, F., Baloković, M., Madejski, G., Mori, K., Puccetti, Simonetta, Leto, C., Perri, M., Verrecchia, F., Villata, M., Raiteri, C. M., Agudo, I., Bachev, R., Berdyugin, A., Blinov, D. A., Chanishvili, R., Chen, W. P., Chigladze, R., Damljanovic, G., Eswaraiah, C., Grishina, T. S., Ibryamov, S., Jordan, B., Jorstad, S. G., Joshi, M., Kopatskaya, E. N., Kurtanidze, O. M., Kurtanidze, S. O., Larionova, E. G., Larionova, L. V., Larionov, V. M., Latev, G., Lin, H. C., Marscher, A. P., Mokrushina, A. A., Morozova, D. A., Nikolashvili, M. G., Semkov, E., Smith, P. S., Strigachev, A., Troitskaya, Yu. V., Troitsky, I. S., Vince, O., Barnes, J., Güver, T., Moody, J. W., Sadun, A. C., Hovatta, T., Richards, J. L., Max-Moerbeck, W., Readhead, A. C. R., Lähteenmäki, A., Tornikoski, M., Tammi, J., Ramakrishnan, V., and Reinthal, R.
Subjects: 13. Climate action, 7. Clean energy
Abstract: The astrophysical journal / Supplement series Supplement series 248(2), 29 - (2020). doi:10.3847/1538-4365/ab89b5, We report on a multiband variability and correlation study of the TeV blazar Mrk 421 during an exceptional flaring activity observed from 2013 April 11 to 19. The study uses, among others, data from GLAST-AGILE Support Program (GASP) of the Whole Earth Blazar Telescope (WEBT), Swift, Nuclear Spectroscopic Telescope Array (NuSTAR), Fermi Large Area Telescope, Very Energetic Radiation Imaging Telescope Array System (VERITAS), and Major Atmospheric Gamma Imaging Cherenkov (MAGIC). The large blazar activity and the 43 hr of simultaneous NuSTAR and MAGIC/VERITAS observations permitted variability studies on 15 minute time bins over three X-ray bands (3–7 keV, 7–30 keV, and 30–80 keV) and three very-high-energy (VHE; >0.1 TeV) gamma-ray bands (0.2–0.4 TeV, 0.4–0.8 TeV, and >0.8 TeV). We detected substantial flux variations on multi-hour and sub-hour timescales in all of the X-ray and VHE gamma-ray bands. The characteristics of the sub-hour flux variations are essentially energy independent, while the multi-hour flux variations can have a strong dependence on the energy of the X-rays and the VHE gamma-rays. The three VHE bands and the three X-ray bands are positively correlated with no time lag, but the strength and characteristics of the correlation change substantially over time and across energy bands. Our findings favor multi-zone scenarios for explaining the achromatic/chromatic variability of the fast/slow components of the light curves, as well as the changes in the flux–flux correlation on day-long timescales. We interpret these results within a magnetic reconnection scenario, where the multi-hour flux variations are dominated by the combined emission from various plasmoids of different sizes and velocities, while the sub-hour flux variations are dominated by the emission from a single small plasmoid moving across the magnetic reconnection layer., Published by Univ. of Chicago Press11033, Chicago, Ill. [u.a.]

36. Testing emission models on the extreme blazar 2WHSP J073326.7+515354 detected at very high energies with the MAGIC telescopes

Author: Acciari, V. A., Ansoldi, S., Antonelli, L. A., Arbet Engels, A., Baack, D., Babić, A., Banerjee, B., Barres De Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bellizzi, L., Bernardini, E., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Bošnjak, Ž, Busetto, G., Carosi, R., Ceribella, G., Cerruti, M., Chai, Y., Chilingaryan, A., Cikota, S., Colak, S. M., Colin, U., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D’Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Depaoli, D., Di Pierro, F., Di Venere, L., Do Souto Espiñeira, E., Dominis Prester, D., Donini, A., Dorner, D., Doro, M., Elsaesser, D., Fallah Ramazani, V., Fattorini, A., Ferrara, G., Fidalgo, D., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Fukami, S., García López, R. J., Garczarczyk, M., Gasparyan, S., Gaug, M., Giglietto, N., Giordano, F., Godinović, N., Green, D., Guberman, D., Hadasch, D., Hahn, A., Herrera, J., Hoang, J., Hrupec, D., Hütten, M., Inada, T., Inoue, S., Ishio, K., Iwamura, Y., Jouvin, L., Kerszberg, D., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., López, M., López-Coto, R., López-Oramas, A., Loporchio, S., Machado De Oliveira Fraga, B., Maggio, C., Majumdar, P., Makariev, M., Mallamaci, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Mazin, D., Mićanović, S., Miceli, D., Minev, M., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Morcuende, D., Moreno, V., Moretti, E., Munar-Adrover, P., Neustroev, V., Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Nozaki, S., Paiano, S., Palacio, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Peñil, P., Peresano, M., Persic, M., Prada Moroni, P. G., Prandini, E., Puljak, I., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Sahakyan, N., Saito, T., Sakurai, S., Satalecka, K., Schmidt, K., Schweizer, T., Sitarek, J., Šnidarić, I., Sobczynska, D., Somero, A., Stamerra, A., Strom, D., Strzys, M., Suda, Y., Surić, T., Takahashi, M., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Torres-Albà, N., Tosti, L., Vagelli, V., Van Scherpenberg, J., Vanzo, G., Vazquez Acosta, M., Vigorito, C. F., Vitale, V., Vovk, I., Will, M., Zarić, D., Asano, K., D’Ammando, F., and Clavero, R.
Subjects: 13. Climate action, 7. Clean energy
Abstract: Monthly notices of the Royal Astronomical Society 490(2), 2284 - 2299 (2019). doi:10.1093/mnras/stz2725, Extreme high-energy-peaked BL Lac objects (EHBLs) are an emerging class of blazars. Their typical two-hump-structured spectral energy distribution (SED) peaks at higher energies with respect to conventional blazars. Multiwavelength (MWL) observations constrain their synchrotron peak in the medium to hard X-ray band. Their gamma-ray SED peaks above the GeV band, and in some objects it extends up to several TeV. Up to now, only a few EHBLs have been detected in the TeV gamma-ray range. In this paper, we report the detection of the EHBL 2WHSP J073326.7+515354, observed and detected during 2018 in TeV gamma rays with the MAGIC telescopes. The broad-band SED is studied within an MWL context, including an analysis of the Fermi-LAT data over 10 yr of observation and with simultaneous Swift-XRT, Swift-UVOT, and KVA data. Our analysis results in a set of spectral parameters that confirms the classification of the source as an EHBL. In order to investigate the physical nature of this extreme emission, different theoretical frameworks were tested to model the broad-band SED. The hard TeV spectrum of 2WHSP J073326.7+515354 sets the SED far from the energy equipartition regime in the standard one-zone leptonic scenario of blazar emission. Conversely, more complex models of the jet, represented by either a two-zone spine-layer model or a hadronic emission model, better represent the broad-band SED., Published by Oxford Univ. Press, Oxford

37. Very-high-energy gamma-ray observations of the Type Ia Supernova SN 2014J with the MAGIC telescopes

Author: Ahnen, M. L., Ansoldi, S., Antonelli, L. A., Antoranz, P., Arcaro, C., Babic, A., Banerjee, B., Bangale, P., Barres De Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bernardini, E., Berti, A., Biasuzzi, B., Biland, A., Blanch, O., Bonnefoy, S., Bonnoli, G., Borracci, F., Bretz, T., Carosi, R., Carosi, A., Chatterjee, A., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Cumani, P., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., De Oña Wilhelmi, E., Di Pierro, F., Doert, M., Domínguez, A., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Eisenacher Glawion, D., Elsaesser, D., Engelkemeier, M., Fallah Ramazani, V., Fernández-Barral, A., Fidalgo, D., Fonseca, M. V., Font, L., Frantzen, K., Fruck, C., Galindo, D., García López, R. J., Garczarczyk, Markus, Garrido Terrats, D., Gaug, M., Giammaria, P., Godinović, N., Gora, Dariusz, Guberman, D., Hadasch, D., Hahn, A., Hayashida, M., Herrera, J., Hose, J., Hrupec, D., Hughes, G., Idec, W., Kodani, K., Konno, Y., Kubo, H., Kushida, J., La Barbera, A., Lelas, D., Lindfors, E., Lombardi, S., Longo, F., López, M., López-Coto, R., Majumdar, P., Makariev, M., Mallot, K., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Marcote, B., Mariotti, M., Martínez, M., Mazin, D., Menzel, U., Miranda, J. M., Mirzoyan, R., Moralejo, A., Moretti, E., Nakajima, D., Neustroev, V., Niedzwiecki, A., Nievas Rosillo, M., Nilsson, K., Nishijima, K., Noda, K., Nogués, L., Paiano, S., Palacio, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Paredes-Fortuny, X., Pedaletti, G., Peresano, M., Perri, L., Persic, M., Poutanen, J., Prada Moroni, P. G., Prandini, E., Puljak, I., Garcia, J. R., Reichardt, I., Rhode, W., Ribó, M., Rico, J., Saito, T., Satalecka, K., Schroeder, S., Schweizer, T., Sillanpää, A., Sitarek, J., Snidaric, I., Sobczynska, D., Stamerra, A., Strzys, M., Surić, T., Takalo, L., Tavecchio, F., Temnikov, P., Terzić, T., Tescaro, D., Teshima, M., Torres, D. F., Toyama, T., Treves, A., Vanzo, G., Vazquez Acosta, M., Vovk, I., Ward, J. E., Will, M., Wu, M. H., and Zanin, R.
Subjects: flux, energy: high, Cherenkov counter, gamma ray: VHE, 13. Climate action, air, supernova, photon, imaging, power spectrum, 7. Clean energy, MAGIC
Abstract: Astronomy and astrophysics 602, A98 (2017). doi:10.1051/0004-6361/201629574, In this work we present data from observations with the MAGIC telescopes of SN 2014J detected on January 21 2014, the closest Type Ia supernova since Imaging Air Cherenkov Telescopes started to operate.Aims. We aim to probe the possibility of very-high-energy (VHE; E ≥ 100 GeV) gamma rays produced in the early stages of Type Ia supernova explosions.Methods. We performed follow-up observations after this supernova (SN) explosion for five days, between January 27 and February 2 2014. We searched for gamma-ray signals in the energy range between 100 GeV and several TeV from the location of SN 2014J using data from a total of ~5.5 h of observations. Prospects for observing gamma rays of hadronic origin from SN 2014J in the near future are also being addressed.Results. No significant excess was detected from the direction of SN 2014J. Upper limits at 95% confidence level on the integral flux, assuming a power-law spectrum, dF/dE ∝ E− Γ, with a spectral index of Γ = 2.6, for energies higher than 300 GeV and 700 GeV, are established at 1.3 × 10$^{-12}$ and 4.1 × 10$^{-13}$ photons cm$^{-2}$ s$^{-2}$, respectively.Conclusions. For the first time, upper limits on the VHE emission of a Type Ia supernova are established. The energy fraction isotropically emitted into TeV gamma rays during the first ~ 10 days after the supernova explosion for energies greater than 300 GeV is limited to 10$^{-6}$ of the total available energy budget (~1051 erg). Within the assumed theoretical scenario, the MAGIC upper limits on the VHE emission suggest that SN 2014J will not be detectable in the future by any current or planned generation of Imaging Atmospheric Cherenkov Telescopes., Published by EDP Sciences, Les Ulis

38. Periastron Observations of TeV Gamma-Ray Emission from a Binary System with a 50-year Period

Author: Abeysekara, A. U., Benbow, W., Bird, R., Brill, A., Brose, R., Buckley, J. H., Chromey, A. J., Daniel, M. K., Falcone, A., Finley, J. P., Fortson, L., Furniss, A., Gent, A., Gillanders, G. H., Hanna, D., Hassan, T., Hervet, O., Holder, J., Hughes, G., Humensky, T. B., Kaaret, P., Kar, P., Kertzman, M., Kieda, D., Krause, M., Krennrich, F., Kumar, S., Lang, M. J., Lin, T. T. Y., Maier, G., Moriarty, P., Mukherjee, R., O’Brien, S., Ong, R. A., Otte, A. N., Park, N., Petrashyk, A., Pohl, M., Pueschel, Elisa, Quinn, J., Ragan, K., Richards, G. T., Roache, E., Sadeh, I., Santander, M., Schlenstedt, S., Sembroski, G. H., Sushch, Iurii, Tyler, J., Vassiliev, V. V., Wakely, S. P., Weinstein, A., Wells, R. M., Wilcox, P., Wilhelm, Alina, Williams, D. A., Williamson, T. J, Zitzer, B., Acciari, V. A., Ansoldi, S., Antonelli, L. A., Engels, A. Arbet, Baack, D., Babić, A., Banerjee, B., De Almeida, U. Barres, Barrio, J. A., González, J. Becerra, Bednarek, W., Bernardini, Elisa, Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Busetto, G., Carosi, R., Ceribella, G., Cikota, S., Colak, S. M., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D’Elia, V., Vela, P. Da, Dazzi, F., Angelis, A. De, Lotto, B. De, Delfino, M., Delgado, J., Pierro, F. Di, Souto Espiñera, E. Do, Domínguez, A., Prester, D. Dominis, Dorner, D., Doro, M., Einecke, S., Elsaesser, D., Ramazani, V. Fallah, Fattorini, A., Fernández-Barral, A., Ferrara, G., Fidalgo, D., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., Gallozzi, S., López, R. J. García, Garczarczyk, M., Gasparyan, S., Gaug, M., Giammaria, P., Godinović, N., Guberman, D., Hadasch, D., Hahn, A., Herrera, J., Hoang, J., Hrupec, D., Inoue, S., Ishio, K., Iwamura, Y., Kubo, H., Kushida, J., Kuveždić, D., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., López, M., López-Oramas, A., De Oliveira Fraga, B. Machado, Maggio, C., Majumdar, P., Makariev, M., Mallamaci, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Masuda, S., Mazin, D., Minev, M., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Moreno, V., Moretti, E., Munar-Adrover, P., Neustroev, V., Niedzwiecki, A., Rosillo, M. Nievas, Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Nöthe, M., Paiano, S., Palacio, J., Paneque, D., Paoletti, R., Paredes, J. M., Pedaletti, G., Peñil, P., Peresano, M., Persic, M., Moroni, P. G. Prada, Prandini, E., Puljak, I., Garcia, J. R., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Sahakyan, N., Saito, T., Satalecka, K., Schweizer, T., Sitarek, J., Šnidarić, I., Sobczynska, D., Somero, A., Stamerra, A., Strzys, M., Surić, T., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Torres-Albà, N., Tsujimoto, S., Scherpenberg, J. Van, Vanzo, G., Acosta, M. Vazquez, Vovk, I., Will, M., and Zarić, D.
Subjects: 13. Climate action
Abstract: The astrophysical journal 867(1), L19 (2018). doi:10.3847/2041-8213/aae70e, We report on observations of the pulsar/Be star binary system PSR J2032+4127/MT91 213 in the energy range between $100\,\mathrm{GeV}$ and $20\,\mathrm{TeV}$ with the Very Energetic Radiation Imaging Telescope Array and Major Atmospheric Gamma Imaging Cherenkov telescope arrays. The binary orbit has a period of approximately 50 years, with the most recent periastron occurring on 2017 November 13. Our observations span from 18 months prior to periastron to one month after. A new point-like gamma-ray source is detected, coincident with the location of PSR J2032+4127/MT91 213. The gamma-ray light curve and spectrum are well characterized over the periastron passage. The flux is variable over at least an order of magnitude, peaking at periastron, thus providing a firm association of the TeV source with the pulsar/Be star system. Observations prior to periastron show a cutoff in the spectrum at an energy around $0.5\,\mathrm{TeV}$. This result adds a new member to the small population of known TeV binaries, and it identifies only the second source of this class in which the nature and properties of the compact object are firmly established. We compare the gamma-ray results with the light curve measured with the X-ray Telescope on board the Neil Gehrels Swift Observatory and with the predictions of recent theoretical models of the system. We conclude that significant revision of the models is required to explain the details of the emission that we have observed, and we discuss the relationship between the binary system and the overlapping steady extended source, TeV J2032+4130., Published by IOP, Chicago, Ill. [u.a.]

39. Monitoring of the radio galaxy M 87 during a low-emission state from 2012 to 2015 with MAGIC

Author: Acciari, V. A., Ansoldi, S., Antonelli, L. A., Arbet Engels, A., Arcaro, C., Baack, D., Babić, A., Banerjee, B., Bangale, P., Barres de Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bellizzi, L., Bernardini, E., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Bošnjak, Ž, Busetto, G., Carosi, R., Ceribella, G., Chai, Y., Chilingaryan, A., Cikota, S., Colak, S. M., Colin, U., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D’Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Depaoli, D., Di Pierro, F., Di Venere, L., Do Souto Espiñeira, E., Dominis Prester, D., Donini, A., Dorner, D., Doro, M., Elsaesser, D., Fallah Ramazani, V., Fattorini, A., Fernández-Barral, A., Ferrara, G., Fidalgo, D., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Fukami, S., García López, R. J., Garczarczyk, M., Gaug, M., Giglietto, N., Godinović, N., Guberman, D., Hadasch, D., Hahn, A., Herrera, J., Hoang, J., Hrupec, D., Hütten, M., Inada, T., Inoue, S., Ishio, K., Iwamura, Y., Kerszberg, D., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., López, M., López-Coto, R., López-Oramas, A., Loporchio, S., Machado de Oliveira Fraga, B., Maggio, C., Majumdar, P., Makariev, M., Mallamaci, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Masuda, S., Mazin, D., Mićanović, S., Miceli, D., Minev, M., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Morcuende, D., Moreno, V., Moretti, E., Munar-Adrover, P., Neustroev, V., Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Nöthe, M., Nozaki, S., Paiano, S., Palacio, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Peñil, P., Peresano, M., Persic, M., Prada Moroni, P. G., Prandini, E., Puljak, I., Rhode, W., Ribó, M., Rico, J., Rugliancich, A., Saha, L., Saito, T., Sakurai, S., Satalecka, K., Schweizer, T., Sitarek, J., Šnidarić, I., Sobczynska, D., Somero, A., Stamerra, A., Strzys, M., Suda, Y., Surić, T., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Torres-Albà, N., Tosti, L., Tsujimoto, S., Vagelli, V., van Scherpenberg, J., Vanzo, G., Acosta, M Vazquez, Vigorito, C. F., Vitale, V., Vovk, I., Will, M., Zarić, D., Asano, Collaborators: K, Hada, K., Giroletti, M., Jermak, H. E., Madrid, J. P., Massaro, F., Spanier, F., Steele, I. A., and MAGIC Collaboration
Subjects: hybrid, galaxy: radio wave, photon, galaxies: active, magnetic field, radiation mechanisms: non-thermal, galaxies: jets, 7. Clean energy, MAGIC, GLAST, galaxies: individual: M 87, monitoring, gamma ray: emission, gamma ray: VHE, synchrotron, gamma rays: galaxies, spectral, gamma ray: flux
Abstract: Monthly notices of the Royal Astronomical Society 492(4), 5354 - 5365 (2020). doi:10.1093/mnras/staa014, M 87 is one of the closest (z = 0.004 36) extragalactic sources emitting at very high energies (VHE, E > 100 GeV). The aim of this work is to locate the region of the VHE gamma-ray emission and to describe the observed broad-band spectral energy distribution (SED) during the low VHE gamma-ray state. The data from M 87 collected between 2012 and 2015 as part of a MAGIC monitoring programme are analysed and combined with multiwavelength data from Fermi-LAT, Chandra, HST, EVN, VLBA, and the Liverpool Telescope. The averaged VHE gamma-ray spectrum can be fitted from ∼100 GeV to ∼10 TeV with a simple power law with a photon index of (−2.41 ± 0.07), while the integral flux above 300 GeV is |$(1.44\pm 0.13)\times 10^{-12}\, \mathrm{cm}^{-2}\, \mathrm{s}^{-1}$|⁠. During the campaign between 2012 and 2015, M 87 is generally found in a low-emission state at all observed wavelengths. The VHE gamma-ray flux from the present 2012–2015M 87 campaign is consistent with a constant flux with some hint of variability (⁠|$\sim 3\, \sigma$|⁠) on a daily time-scale in 2013. The low-state gamma-ray emission likely originates from the same region as the flare-state emission. Given the broad-band SED, both a leptonic synchrotron self-Compton and a hybrid photohadronic model reproduce the available data well, even if the latter is preferred. We note, however, that the energy stored in the magnetic field in the leptonic scenario is very low, suggesting a matter-dominated emission region., Published by Oxford Univ. Press, Oxford

40. MAGIC upper limits on the GRB 090102 afterglow

Author: Aleksić, J., Ansoldi, S., Antonelli, L. A., Antoranz, P., Babic, A., De Almeida, U. B., Barrio, J. A., Gonzalez, J. B., Bednarek, W., Berger, K., Bernardini, E., Biland, A., Blanch, O., Bock, R. K., Boller, A., Bonnefoy, S., Bonnoli, G., Borracci, F., Bretz, T., Carmona, E., Carosi, A., Fidalgo, D. C., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Cossio, L., Covino, S., Da Vela, P., Dazzi, F., De Angelis, A., De Caneva, G., De Lotto, B., Mendez, C. D., Doert, M., Dominguez, A., Prester, D. D., Dorner, D., Doro, M., Eisenacher, D., Elsaesser, D., Farina, E., Ferenc, D., Fonseca, M. V., Font, L., Frantzen, K., Fruck, C., Lopez, R. J. G., Garczarczyk, M., Terrats, D. G., Gaug, M., Giavitto, G., Godinovic, N., Munoz, A. G., Gozzini, S. R., Hadamek, A., Hadasch, D., Herrero, A., Hose, J., Hrupec, D., Idec, W., Kadenius, V., Knoetig, M. L., Krahenbuhl, T., Krause, J., Kushida, J., Barbera, A. L., Lelas, D., Lewandowska, N., Lindfors, E., Lombardi, S., Lopez-Coto, R., Lopez, M., Lopez-Oramas, A., Lorenz, E., Lozano, I., Makariev, M., Mallot, K., Maneva, G., Mankuzhiyil, N., Mannheim, K., Maraschi, L., Marcote, B., Mariotti, M., Martinez, M., Masbou, J., Mazin, D., Menzel, U., Meucci, M., Miranda, J. M., Mirzoyan, R., Moldon, J., Moralejo, A., Munar-Adrover, P., Nakajima, D., Niedzwiecki, A., Nilsson, K., Nowak, N., Orito, R., Overkemping, A., Paiano, S., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Partini, S., Persic, M., Prada, F., Moroni, P. G. P., Prandini, E., Preziuso, S., Puljak, I., Reichardt, I., Reinthal, R., Rhode, W., Ribo, M., Rico, J., Garcia, J. R., Rugamer, S., Saggion, A., Saito, K., Saito, T., Salvati, M., Satalecka, K., Scalzotto, V., Scapin, V., Schultz, C., Schweizer, T., Shore, S. N., Sillanpaa, A., Sitarek, J., Snidaric, I., Sobczynska, D., Spanier, F., Stamatescu, V., Stamerra, A., Storz, J., Sun, S., Suric, T., Takalo, L., Tavecchio, F., Temnikov, P., Terzic, T., Tescaro, D., Teshima, M., Thaele, J., Tibolla, O., Torres, D. F., Toyama, T., Treves, A., Uellenbeck, M., Vogler, P., Wagner, R. M., Weitzel, Q., Zandanel, F., Zanin, R., Bouvier, A., Hayashida, M., Tajima, H., and Longo, F.
Subjects: 7. Clean energy
Abstract: Monthly notices of the Royal Astronomical Society 437(4), 3103 - 3111 (2014). doi:10.1093/mnras/stt2041, Published by Wiley-Blackwell, Oxford [u.a.]

41. MAGIC very large zenith angle observations of the Crab Nebula up to 100 TeV

Author: Acciari, V. A., Antonelli, L. A., Arbet Engels, A., Baack, D., Babić, A., Banerjee, B., Barres De Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bellizzi, L., Bernardini, E., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Bošnjak, Ž., Busetto, G., Carosi, R., Ceribella, G., Chai, Y., Chilingaryan, A., Cikota, S., Colak, S. M., Colin, U., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D’Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Depaoli, D., Di Pierro, F., Di Venere, L., Do Souto Espiñeira, E., Dominis Prester, D., Donini, A., Dorner, D., Doro, M., Elsaesser, D., Fallah Ramazani, V., Fattorini, A., Ferrara, G., Fidalgo, D., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Fukami, S., García López, R. J., Garczarczyk, M., Gasparyan, S., Gaug, M., Giglietto, N., Giordano, F., Godinović, N., Green, D., Guberman, D., Hadasch, D., Hahn, A., Herrera, J., Hoang, J., Hrupec, D., Hütten, M., Inada, T., Inoue, S., Ishio, K., Iwamura, Y., Jouvin, L., Kerszberg, D., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., López, M., López-Coto, R., López-Oramas, A., Loporchio, S., Machado De Oliveira Fraga, B., Maggio, C., Majumdar, P., Makariev, M., Mallamaci, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Mazin, D., Mićanović, S., Miceli, D., Minev, M., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Morcuende, D., Moreno, V., Moretti, E., Munar-Adrover, P., Neustroev, V., Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Nozaki, S., Paiano, S., Palacio, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Peñil, P., Peresano, M., Persic, M., Prada Moroni, P. G., Prandini, E., Puljak, I., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Sahakyan, N., Saito, T., Sakurai, S., Satalecka, K., Schmidt, K., Schweizer, T., Sitarek, J., Šnidarić, I., Sobczynska, D., Somero, A., Stamerra, A., Strom, D., Strzys, M., Suda, Y., Surić, T., Takahashi, M., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Torres-Albà, N., Tosti, L., Vagelli, V., Van Scherpenberg, J., Vanzo, G., Vazquez Acosta, M., Vigorito, C. F., Vitale, V., Vovk, I., Will, M., and Zarić, D.
Subjects: energy: high, imaging, gamma rays: general, calibration, MAGIC, emission: model, atmosphere: monitoring, gamma ray: emission, Cherenkov counter, optical, spectral, 14. Life underwater, methods: observational, ISM: supernova remnants
Abstract: Astronomy and astrophysics 635, A158 (1-10) (2020). doi:10.1051/0004-6361/201936899, Aims. We measure the Crab Nebula $γ$-ray spectral energy distribution in the ~100 TeV energy domain and test the validity of existing leptonic emission models at these high energies.Methods. We used the novel very large zenith angle observations with the MAGIC telescope system to increase the collection area above 10 TeV. We also developed an auxiliary procedure of monitoring atmospheric transmission in order to assure proper calibration of the accumulated data. This employs recording optical images of the stellar field next to the source position, which provides a better than 10% accuracy for the transmission measurements.Results. We demonstrate that MAGIC very large zenith angle observations yield a collection area larger than a square kilometer. In only ~ 56 h of observations, we detect the γ-ray emission from the Crab Nebula up to 100 TeV, thus providing the highest energy measurement of this source to date with Imaging Atmospheric Cherenkov Telescopes. Comparing accumulated and archival MAGIC and Fermi/LAT data with some of the existing emission models, we find that none of them provides an accurate description of the 1 GeV to 100 TeV $γ$-ray signal., Published by EDP Sciences, Les Ulis

42. Study of the variable broadband emission of Markarian 501 during the most extreme Swift X-ray activity

Author: Acciari, V. A., Ansoldi, S., Antonelli, L. A., Babić, A., Banerjee, B., Barres De Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bernardini, E., Berti$, Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Blanch, O., Bonnoli, G., Busetto, G., Carosi, R., Ceribella, G., Cikota, S., Colak, S. M., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D'Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino$, Delgado$, Di Pierro, F., Do Souto Espiñera, E., Domínguez, A., Dominis Prester, D., Doro, M., Fallah Ramazani, V., Fattorini, A., Fernández-Barral, A., Ferrara, G., Fidalgo, D., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., Gallozzi, S., García López, R. J., Garczarczyk, Markus, Gasparyan, S., Gaug, M., Giammaria, P., Godinović, N., Guberman, D., Hadasch, D., Hahn, A., Hassan, T., Herrera, J., Hoang, J., Hrupec, D., Inoue, S., Ishio, K., Iwamura, Y., Kubo, H., Kushida, J., Kuveždić, D., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo$, López, M., López-Oramas, A., Machado De Oliveira Fraga, B., Maggio, C., Majumdar, P., Makariev, M., Mallamaci, M., Maneva, G., Manganaro, M., Maraschi, L., Mariotti, M., Martínez, M., Masuda, S., Mazin, D., Minev, M., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Moreno, V., Moretti, E., Munar-Adrover, P., Neustroev, V., Niedzwiecki, A., Nievas Rosillo, M., Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Paiano, S., Palacio, J., Paneque, D., Paoletti, R., Paredes, J. M., Pedaletti, Giovanna, Peñil, P., Peresano, M., Persic$, Prada Moroni, P. G., Prandini, E., Puljak, I., Garcia, J. R., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Sahakyan, N., Saito, T., Satalecka, K., Schweizer, T., Sitarek, J., Šnidarić, I., Sobczynska, D., Somero, A., Stamerra, A., Strzys, M., Surić, T., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Torres-Albà, N., Tsujimoto, S., Van Scherpenberg, J., Vanzo, G., Vazquez Acosta, M., Vovk, I., Will, M., Zarić, D., Arbet-Engels, A., Baack, D., Balbo, M., Biland, A., Blank, M., Bretz, T., Bruegge, K., Bulinski, M., Buss, J., Doerr, M., Dorner, D., Einecke, S., Elsaesser, D., Hildebrand, D., Linhoff, L., Mannheim, K., Mueller, S., Neise, D., Neronov, A., Noethe, M., Paravac, A., Rhode, W., Schleicher, B., Schulz, F., Sedlaczek, K., Shukla, A., Sliusar, V., Von Willert, E., Walter, R., Wendel, Cato Christian, Tramacere, A., Lien, A., Perri, M., Verrecchia, F., Armas Padilla, M., Leto, C., Lähteenmäki, A., Tornikoski, M., and Tammi, J.
Subjects: 7. Clean energy
Abstract: Astronomy and astrophysics 637, A86 - (2020). doi:10.1051/0004-6361/201834603, Context. Markarian 501 (Mrk 501) is a very high-energy (VHE) gamma-ray blazar located at z = 0.034, which is regularly monitored by a wide range of multi-wavelength instruments, from radio to VHE gamma rays. During a period of almost two weeks in July 2014, the highest X-ray activity of Mrk 501 was observed in ∼14 years of operation of the Neil Gehrels Swift Gamma-ray Burst Observatory.Aims. We characterize the broadband variability of Mrk 501 from radio to VHE gamma rays during the most extreme X-ray activity measured in the last 14 years, and evaluate whether it can be interpreted within theoretical scenarios widely used to explain the broadband emission from blazars.Methods. The emission of Mrk 501 was measured at radio with Metsähovi, at optical–UV with KVA and Swift/UVOT, at X-ray with Swift/XRT and Swift/BAT, at gamma ray with Fermi-LAT, and at VHE gamma rays with the FACT and MAGIC telescopes. The multi-band variability and correlations were quantified, and the broadband spectral energy distributions (SEDs) were compared with predictions from theoretical models.Results. The VHE emission of Mrk 501 was found to be elevated during the X-ray outburst, with a gamma-ray flux above 0.15 TeV varying from ∼0.5 to ∼2 times the Crab nebula flux. The X-ray and VHE emission both varied on timescales of 1 day and were found to be correlated. We measured a general increase in the fractional variability with energy, with the VHE variability being twice as large as the X-ray variability. The temporal evolution of the most prominent and variable segments of the SED, characterized on a day-by-day basis from 2014 July 16 to 2014 July 31, is described with a one-zone synchrotron self-Compton model with variations in the break energy of the electron energy distribution (EED), and with some adjustments in the magnetic field strength and spectral shape of the EED. These results suggest that the main flux variations during this extreme X-ray outburst are produced by the acceleration and the cooling of the high-energy electrons. A narrow feature at ∼3 TeV was observed in the VHE spectrum measured on 2014 July 19 (MJD 56857.98), which is the day with the highest X-ray flux (>0.3 keV) measured during the entire Swift mission. This feature is inconsistent with the classical analytic functions to describe the measured VHE spectra (power law, log-parabola, and log-parabola with exponential cutoff) at more than 3σ. A fit with a log-parabola plus a narrow component is preferred over the fit with a single log-parabola at more than 4σ, and a dedicated Monte Carlo simulation estimated the significance of this extra component to be larger than 3σ. Under the assumption that this VHE spectral feature is real, we show that it can be reproduced with three distinct theoretical scenarios: (a) a pileup in the EED due to stochastic acceleration; (b) a structured jet with two-SSC emitting regions, with one region dominated by an extremely narrow EED; and (c) an emission from an IC pair cascade induced by electrons accelerated in a magnetospheric vacuum gap, in addition to the SSC emission from a more conventional region along the jet of Mrk 501.Key words: galaxies: active / BL Lacertae objects: individual: Mrk 501 / gamma rays: galaxies / X-rays: galaxies⋆ Corresponding authors: J. Becerra González, jbecerra@iac.es; D. Paneque, dpaneque@mppmu.mpg.de; C. Wendel, cwendel@astro.uni-wuerzburg.de., Published by EDP Sciences, Les Ulis

43. The broad-band properties of the intermediate synchrotron peaked BL Lac S2 0109+22 from radio to VHE gamma-rays

Author: Ansoldi, S., Antonelli, L. A., Arcaro, C., Baack, D., Babić, A., Banerjee, B., Bangale, P., Barres De Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bernardini, E., Berse, R Ch, Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Carosi, R., Ceribella, G., Chatterjee, A., Colak, S. M., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Cumani, P., D’Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Di Pierro, F., Domínguez, A., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Elsaesser, D., Fallah Ramazani, V., Fattorini, A., Fernández-Barral, A., Ferrara, G., Fidalgo, D., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Gallozzi, S., García López, R. J., Garczarczyk, M., Gaug, M., Giammaria, P., Godinović, N., Guberman, D., Hadasch, D., Hahn, A., Hassan, T., Hayashida, M., Herrera, J., Hoang, J., Hrupec, D., Inoue, S., Ishio, K., Iwamura, Y., Konno, Y., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., López, M., Maggio, C., Majumdar, P., Makariev, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Masuda, S., Mazin, D., Mielke, K., Minev, M., Miranda, J. M., Mirzoyan, R., Moralejo, A., Moreno, V., Moretti, E., Neustroev, V., Niedzwiecki, A., Nievas Rosillo, M., Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Paiano, S., Palacio, J., Paneque, D., Paoletti, R., Paredes, J. M., Pedaletti, G., Peñil, P., Peresano, M., Persic, M., Pfrang, K., Prada Moroni, P. G., Prandini, E., Puljak, I., Garcia, J. R., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Saito, T., Satalecka, K., Schweizer, T., Sitarek, J., Šnidarić, I., Sobczynska, D., Stamerra, A., Strzys, M., Surić, T., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Torres-Albà, N., Tsujimoto, S., Vanzo, G., Vazquez Acosta, M., Vovk, I., Ward, J. E., Will, M., Zarić, D., Barcewicz, S., Hovatta, T., Jormanainen, J., Takalo, L., Reinthal, R., Mankuzhiyil, N., Wierda, F., Lähteenmäki, A., Tammi, J., Tornikoski, M., Vera, R. J. C., Kiehlmann, S., Max-Moerbeck, W., and Readhead, A. C. S.
Subjects: 13. Climate action
Abstract: Monthly notices of the Royal Astronomical Society 480(1), 879 - 892 (2018). doi:10.1093/mnras/sty1753, The Major Atmospheric Gamma-ray Imaging Cherenkov (MAGIC) telescopes observed S2 0109+22 in 2015 July during its flaring activity in high-energy gamma-rays observed by Fermi-Large Area Telescope. We analyse the MAGIC data to characterize the very high energy (VHE) gamma-ray emission of S2 0109+22, which belongs to the subclass of intermediate synchrotron peak (ISP) BL Lacertae (BL Lac) objects. We study the multifrequency emission in order to investigate the source classification. Finally, we compare the source long-term behaviour to other VHE gamma-ray emitting (TeV) blazars. We performed a temporal and spectral analysis of the data centred around the MAGIC interval of observation (MJD 57225–57231). Long-term radio and optical data have also been investigated using the discrete correlation function. The redshift of the source is estimated through optical host-galaxy imaging and also using the amount of VHE gamma-ray absorption. The quasi-simultaneous multifrequency spectral energy distribution (SED) is modelled with the conventional one-zone synchrotron self-Compton (SSC) model. MAGIC observations resulted in the detection of the source at a significance level of 5.3σ. The VHE gamma-ray emission of S2 0109+22 is variable on a daily time scale. VHE gamma-ray luminosity of the source is lower than the average of TeV BL Lacs. The optical polarization and long-term optical/radio behaviour of the source are different from the general population of TeV blazars. All these findings agree with the classification of the source as an ISP BL Lac object. We estimate the source redshift as $z$ = 0.36 ± 0.07. The SSC parameters describing the SED are rather typical for blazars., Published by Oxford Univ. Press, Oxford

44. Constraints on particle acceleration in SS433/W50 from MAGIC and H.E.S.S. observations

Author: Ahnen, M. L., Ansoldi, S., Antonelli, L. A., Arcaro, C., Babić, A., Banerjee, B., Bangale, P., Barres De Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bernardini, E., Berti, A., Biasuzzi, B., Biland, A., Blanch, O., Bonnefoy, S., Bonnoli, G., Borracci, F., Carosi, R., Carosi, A., Chatterjee, A., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Cumani, P., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., De Oña Wilhelmi, E., Di Pierro, F., Doert, M., Domínguez, A., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Eisenacher Glawion, D., Elsaesser, D., Engelkemeier, M., Fallah Ramazani, V., Fernández-Barral, A., Fidalgo, D., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., García López, R. J., Garczarczyk, M., Gaug, M., Giammaria, P., Godinović, N., Gora, D., Griffiths, S., Guberman, D., Hadasch, D., Hahn, A., Hassan, T., Hayashida, M., Herrera, J., Hose, J., Hrupec, D., Hughes, G., Ishio, K., Konno, Y., Kubo, H., Kushida, J., Kuveždić, D., Lelas, D., Lindfors, E., Lombardi, S., Longo, F., López, M., López-Oramas, A., Majumdar, P., Makariev, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Mazin, D., Menzel, U., Minev, M., Mirzoyan, R., Moralejo, A., Moreno, V., Moretti, E., Munar-Adrover, P., Neustroev, V., Niedzwiecki, A., Nievas Rosillo, M., Nilsson, K., Nishijima, K., Noda, K., Nogués, L., Paiano, S., Palacio, J., Paneque, D., Paoletti, R., Paredes, J. M., Paredes-Fortuny, X., Pedaletti, G., Peresano, M., Perri, L., Persic, M., Prada Moroni, P. G., Prandini, E., Puljak, I., Garcia, J. R., Reichardt, I., Rhode, W., Ribó, M., Rico, J., Saito, T., Satalecka, K., Schroeder, S., Schweizer, T., Shore, S. N., Sillanpää, A., Sitarek, J., Šnidarić, I., Sobczynska, D., Stamerra, A., Strzys, M., Surić, T., Takalo, L., Tavecchio, F., Temnikov, P., Terzić, T., Tescaro, D., Teshima, M., Torres, D. F., Torres-Albà, N., Treves, A., Vanzo, G., Vazquez Acosta, M., Vovk, I., Ward, J. E., Will, M., Wu, M. H., Zarić, D., Abdalla, H., Abramowski, A., Aharonian, F., Ait Benkhali, F., Akhperjanian, A. G., Andersson, T., Angüner, E. O., Arakawa, M., Arrieta, M., Aubert, P., Backes, M., Balzer, A., Barnard, M., Becherini, Y., Becker Tjus, J., Berge, D., Bernhard, S., Bernlöhr, K., Blackwell, R., Böttcher, M., Boisson, C., Bolmont, J., Bordas, P., Bregeon, J., Brun, F., Brun, P., Bryan, M., Büchele, M., Bulik, T., Capasso, M., Carr, J., Casanova, S., Cerruti, M., Chakraborty, N., Chalme-Calvet, R., Chaves, R. C. G., Chen, A., Chevalier, J., Chrétien, M., Coffaro, M., Colafrancesco, S., Cologna, G., Condon, B., Conrad, J., Cui, Y., Davids, I. D., Decock, J., Degrange, B., Deil, C., Devin, J., DeWilt, P., Dirson, L., Djannati-Ataï, A., Domainko, W., Donath, A., Drury, L. O’C., Dutson, K., Dyks, J., Edwards, T., Egberts, K., Eger, P., Ernenwein, J.-P., Eschbach, S., Farnier, C., Fegan, S., Fernandes, M. V., Fiasson, A., Fontaine, G., Förster, A., Funk, S., Füßling, M., Gabici, S., Gajdus, M., Gallant, Y. A., Garrigoux, T., Giavitto, G., Giebels, B., Glicenstein, J. F., Gottschall, D., Goyal, A., Grondin, M.-H., Hahn, J., Haupt, M., Hawkes, J., Heinzelmann, G., Henri, G., Hermann, G., Hervet, O., Hinton, J. A., Hofmann, W., Hoischen, C., Holler, M., Horns, D., Ivascenko, A., Iwasaki, H., Jacholkowska, A., Jamrozy, M., Janiak, M., Jankowsky, D., Jankowsky, F., Jingo, M., Jogler, T., Jouvin, L., Jung-Richardt, I., Kastendieck, M. A., Katarzyński, K., Katsuragawa, M., Katz, U., Kerszberg, D., Khangulyan, D., Khélifi, B., Kieffer, M., King, J., Klepser, S., Klochkov, D., Kluźniak, W., Kolitzus, D., Komin, Nu., Kosack, K., Krakau, S., Kraus, M., Krüger, P. P., Laffon, H., Lamanna, G., Lau, J., Lees, J.-P., Lefaucheur, J., Lefranc, V., Lemière, A., Lemoine-Goumard, M., Lenain, J.-P., Leser, E., Lohse, T., Lorentz, M., Liu, R., López-Coto, R., Lypova, I., Marandon, V., Marcowith, A., Mariaud, C., Marx, R., Maurin, G., Maxted, N., Mayer, M., Meintjes, P. J., Meyer, M., Mitchell, A. M. W., Moderski, R., Mohamed, M., Mohrmann, L., Morå, K., Moulin, E., Murach, T., Nakashima, S., De Naurois, M., Niederwanger, F., Niemiec, J., Oakes, L., O’Brien, P., Odaka, H., Öttl, S., Ohm, S., Ostrowski, M., Oya, I., Padovani, M., Panter, M., Parsons, R. D., Pekeur, N. W., Pelletier, G., Perennes, C., Petrucci, P.-O., Peyaud, B., Piel, Q., Pita, S., Poon, H., Prokhorov, D., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Reimer, A., Reimer, O., Renaud, M., De Los Reyes, R., Richter, S., Rieger, F., Romoli, C., Rowell, G., Rudak, B., Rulten, C. B., Safi-Harb, S., Sahakian, V., Saito, S., Salek, D., Sanchez, D. A., Santangelo, A., Sasaki, M., Schlickeiser, R., Schüssler, F., Schulz, Anneli, Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Settimo, M., Seyffert, A. S., Shafi, N., Shilon, I., Simoni, R., Sol, H., Spanier, F., Spengler, G., Spies, F., Stawarz, Ł., Steenkamp, R., Stegmann, C., Stycz, K., Sushch, I., Takahashi, T., Tavernet, J.-P., Tavernier, T., Taylor, A. M., Terrier, R., Tibaldo, L., Tiziani, D., Tluczykont, M., Trichard, C., Tsuji, N., Tuffs, R., Uchiyama, Y., Van Der Walt, D. J., Van Eldik, C., Van Rensburg, C., Van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Viana, A., Vincent, P., Vink, J., Voisin, F., Völk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Wagner, P., Wagner, R. M., White, R., Wierzcholska, A., Willmann, P., Wörnlein, A., Wouters, D., Yang, R., Zabalza, V., Zaborov, D., Zacharias, M., Zanin, R., Zdziarski, A. A., Zech, A., Zefi, F., Ziegler, A., and Zywucka, N.
Subjects: 7. Clean energy
Abstract: Astronomy and astrophysics 612, A14 (2018). doi:10.1051/0004-6361/201731169, Context. The large jet kinetic power and non-thermal processes occurring in the microquasar SS 433 make this source a good candidate for a very high-energy (VHE) gamma-ray emitter. Gamma-ray fluxes above the sensitivity limits of current Cherenkov telescopes have been predicted for both the central X-ray binary system and the interaction regions of SS 433 jets with the surrounding W50 nebula. Non-thermal emission at lower energies has been previously reported, indicating that efficient particle acceleration is taking place in the system.Aim. We explore the capability of SS 433 to emit VHE gamma rays during periods in which the expected flux attenuation due to periodic eclipses (P$_{orb}$ ~ 13.1 days) and precession of the circumstellar disk (P$_{pre}$ ~ 162 days) periodically covering the central binary system is expected to be at its minimum. The eastern and western SS 433/W50 interaction regions are also examined using the whole data set available. We aim to constrain some theoretical models previously developed for this system with our observations.Methods. We made use of dedicated observations from the Major Atmospheric Gamma Imaging Cherenkov telescopes (MAGIC) and High Energy Spectroscopic System (H.E.S.S.) of SS 433 taken from 2006 to 2011. These observation were combined for the first time and accounted for a total effective observation time of 16.5 h, which were scheduled considering the expected phases of minimum absorption of the putative VHE emission. Gamma-ray attenuation does not affect the jet/medium interaction regions. In this case, the analysis of a larger data set amounting to ~40–80 h, depending on the region, was employed.Results. No evidence of VHE gamma-ray emission either from the central binary system or from the eastern/western interaction regions was found. Upper limits were computed for the combined data set. Differential fluxes from the central system are found to be ≲ 10$^{−12}$–10$^{−13}$ TeV$^{−1}$ cm$^{−2}$ s$^{−1}$ in an energy interval ranging from ~few × 100 GeV to ~few TeV. Integral flux limits down to ~ 10$^{−12}$–10$^{−13}$ ph cm$^{−2}$ s$^{−1}$ and ~ 10$^{−13}$–10$^{−14}$ ph cm$^{−2}$ s$^{−1}$ are obtainedat 300 and 800 GeV, respectively. Our results are used to place constraints on the particle acceleration fraction at the inner jetregions and on the physics of the jet/medium interactions.Conclusions. Our findings suggest that the fraction of the jet kinetic power that is transferred to relativistic protons must be relatively small in SS 433, qp ≤ 2.5 × 10$^{−5}$, to explain the lack of TeV and neutrino emission from the central system. At the SS 433/W50 interface, the presence of magnetic fields ≳10 μG is derived assuming a synchrotron origin for the observed X-ray emission. This also implies the presence of high-energy electrons with E$_{e−}$ up to 50 TeV, preventing an efficient production of gamma-ray fluxes in these interaction regions., Published by EDP Sciences, Les Ulis

45. First Multi-wavelength Campaign on the Gamma-ray-loud Active Galaxy IC 310

Author: Ahnen, M. L., Ansoldi, S., Antonelli, L. A., Arcaro, C., Babić, A., Banerjee, B., Bangale, P., Barres De Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bernardini, E., Berti, A., Biasuzzi, B., Biland, A., Blanch, O., Bonnefoy, S., Bonnoli, G., Borracci, F., Bretz, T., Carosi, R., Carosi, A., Chatterjee, A., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Cumani, P., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Wilhelmi, E. De Oña, Di Pierro, F., Doert, M., Domínguez, A., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Glawion, D. Eisenacher, Elsaesser, D., Engelkemeier, M., Ramazani, V. Fallah, Fernández-Barral, A., Fidalgo, D., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., López, R. J. García, Garczarczyk, M., Gaug, M., Giammaria, P., Godinović, N., Gora, D., Guberman, D., Hadasch, D., Hahn, A., Hassan, T., Hayashida, M., Herrera, J., Hose, J., Hrupec, D., Hughes, G., Idec, W., Ishio, K., Kodani, K., Konno, Y., Kubo, H., Kushida, J., Lelas, D., Lindfors, E., Lombardi, S., Longo, F., López, M., Majumdar, P., Makariev, M., Mallot, K., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Mazin, D., Menzel, U., Mirzoyan, R., Moralejo, A., Moretti, E., Nakajima, D., Neustroev, V., Niedzwiecki, A., Rosillo, M. Nievas, Nilsson, K., Nishijima, K., Noda, K., Nogués, L., Nöthe, M., Paiano, S., Palacio, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Paredes-Fortuny, X., Pedaletti, G., Peresano, M., Perri, L., Persic, M., Poutanen, J., Prada Moroni, P. G., Prandini, E., Puljak, I., Garcia, J. R., Reichardt, I., Rhode, W., Ribó, M., Rico, J., Saito, T., Satalecka, K., Schroeder, S., Schweizer, T., Shore, S. N., Sillanpää, A., Sitarek, J., Snidaric, I., Sobczynska, D., Stamerra, A., Strzys, M., Surić, T., Takalo, L., Tavecchio, F., Temnikov, P., Terzić, T., Tescaro, D., Teshima, M., Torres, D. F., Torres-Albà, N., Toyama, T., Treves, A., Vanzo, G., Vazquez Acosta, M., Vovk, I., Ward, J. E., Will, M., Wu, M. H., Krauß, F., Schulz, R., Kadler, M., Wilms, J., Ros, E., Bach, U., Beuchert, T., Langejahn, M., Wendel, C., Gehrels, N., Baumgartner, W. H., Markwardt, C. B., Müller, C., Grinberg, V., Hovatta, T., and Magill, J.
Subjects: 3. Good health
Abstract: Astronomy and astrophysics 603, A25 (2017). doi:10.1051/0004-6361/201630347, Context. The extragalactic very-high-energy gamma-ray sky is rich in blazars. These are jetted active galactic nuclei that are viewed at a small angle to the line-of-sight. Only a handful of objects viewed at a larger angle are so far known to emit above 100 GeV. Multi-wavelength studies of such objects up to the highest energies provide new insights into the particle and radiation processes of active galactic nuclei. Aims. We aim to report the results from the first multi-wavelength campaign observing the TeV detected nucleus of the active galaxy IC 310, whose jet is observed at a moderate viewing angle of 10°−20°. Methods. The multi-instrument campaign was conducted between 2012 November and 2013 January, and involved observations with MAGIC, Fermi, INTEGRAL, Swift, OVRO, MOJAVE and EVN. These observations were complemented with archival data from the AllWISE and 2MASS catalogs. A one-zone synchrotron self-Compton model was applied to describe the broadband spectral energy distribution. Results. IC 310 showed an extraordinary TeV flare at the beginning of the campaign, followed by a low, but still detectable TeV flux. Compared to previous measurements in this energy range, the spectral shape was found to be steeper during the low emission state. Simultaneous observations in the soft X-ray band showed an enhanced energy flux state and a harder-when-brighter spectral shape behavior. No strong correlated flux variability was found in other frequency regimes. The broadband spectral energy distribution obtained from these observations supports the hypothesis of a double-hump structure. Conclusions. The harder-when-brighter trend in the X-ray and VHE emission, observed for the first time during this campaign, is consistent with the behavior expected from a synchrotron self-Compton scenario. The contemporaneous broadband spectral energy distribution is well described with a one-zone synchrotron self-Compton model using parameters that are comparable to those found for other gamma-ray-emitting misaligned blazars. Key words: galaxies: active / galaxies: individual: IC 310 / gamma rays: galaxies, Published by EDP Sciences, Les Ulis

46. Multiwavelength variability and correlation studies of Mrk 421 during historically low X-ray and $\gamma$-ray activity in 2015$-$2016

Author: Acciari, V. A., Ansoldi, S., Antonelli, L. A., Asano, K., Babić, A., Banerjee, Debasish, Baquero, A., Barres de Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bellizzi, L., Bernardini, Elisa, Bernardos, M., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Blanch, O., Bonnoli, G., Bošnjak, Z., Busetto, G., Carosi, R., Ceribella, G., Cerruti, M., Chai, Y., Chilingarian, A., Cikota, S., Colak, S. M., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D'Amico, G., D'Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Delgado Mendez, C., Depaoli, D., Di Girolamo, T., Di Pierro, F., Di Venere, L., Do Souto Espiñeira, E., Dominis Prester, D., Donini, A., Doro, M., Fallah Ramazani, V., Fattorini, A., Ferrara, G., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Fukami, S., García López, R. J., Garczarczyk, Markus, Gasparyan, S., Gaug, M., Giglietto, N., Giordano, F., Gliwny, P., Godinović, N., Green, J. G., Green, D., Hadasch, D., Hahn, A., Heckmann, L., Herrera, J., Hoang, J., Hrupec, D., Hütten, M., Inada, T., Inoue, S., Ishio, K., Iwamura, Y., Jormanainen, J., Jouvin, L., Kajiwara, Y., Karjalainen, M., Kerszberg, D., Kobayashi, Y., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., López, M., López-Coto, R., López-Oramas, A., Loporchio, S., Machado de Oliveira Fraga, B., Maggio, C., Majumdar, P., Makariev, M., Mallamaci, M., Maneva, G., Manganaro, M., Maraschi, L., Mariotti, M., Martínez, M., Mazin, D., Mender, S., Mićanović, S., Miceli, D., Miener, T., Minev, M., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Morcuende, D., Moreno, V., Moretti, E., Munar-Adrover, P., Neustroev, V., Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nozaki, S., Ohtani, Y., Oka, T., Otero-Santos, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Pavletić, L., Peñil, P., Perennes, C., Persic, M., Prada Moroni, P. G., Prandini, E., Priyadarshi, C., Puljak, I., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Sahakyan, N., Saito, T., Sakurai, S., Satalecka, Konstancja, Schleicher, B., Schmidt, K., Schweizer, T., Sitarek, J., Šnidarić, I., Sobczynska, D., Spolon, A., Stamerra, A., Strom, D., Strzys, M., Suda, Y., Surić, T., Takahashi, M., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Torres-Albà, N., Tosti, L., Truzzi, S., van Scherpenberg, J., Vanzo, G., Vazquez Acosta, M., Ventura, S., Verguilov, V., Vigorito, C. F., Vitale, V., Vovk, I., Will, M., Zarić, D., Arbet-Engels, A., Baack, D., Balbo, M., Beck, M., Biederbeck, N., Biland, A., Bretz, T., Bruegge, K., Buss, J., Dorner, D., Elsaesser, D., Hildebrand, D., Iotov, R., Klinger, M., Mannheim, K., Neise, D., Neronov, A., Noethe, M., Paravac, A., Sliusar, V., Theissen, F., Walter, R., Valverde, J., Horan, D., Giroletti, M., Perri, M., Verrecchia, F., Leto, C., Sadun, A. C., Moody, J. W., Joner, M., Marscher, A. P., Jorstad, S. G., Lähteenmäki, A., Tornikoski, M., Ramakrishnan, V., Järvelä, E., Vera, R. J. C., Righini, S., and Lien, A. Y.
Subjects: radio wave, galaxies: active, GeV, 4/3, radiation mechanisms: non-thermal, MAGIC, methods: data analysis, GLAST, VHE, blazar, X-ray, flux, 13. Climate action, gamma ray, correlation, synchrotron, optical, TeV, spectral, BL Lacertae objects: individual: Mrk 421, methods: observational
Abstract: Monthly notices of the Royal Astronomical Society 504(1), 1427 (2021). doi:10.1093/mnras/staa3727, We report a characterization of the multiband flux variability and correlations of the nearby (z = 0.031) blazar Markarian 421 (Mrk 421) using data from Metsähovi, Swift, Fermi-LAT, MAGIC, FACT, and other collaborations and instruments from 2014 November till 2016 June. Mrk 421 did not show any prominent flaring activity, but exhibited periods of historically low activity above 1 TeV (F_>1 TeV < 1.7 × 10^−12 ph cm^−2 s^−1) and in the 2–10 keV (X-ray) band (F|$_{2-10\, \mathrm{keV}}\lt 3.6\times 10^{-11}$| erg cm^−2 s^−1), during which the Swift-BAT data suggest an additional spectral component beyond the regular synchrotron emission. The highest flux variability occurs in X-rays and very high-energy (E > 0.1 TeV) γ-rays, which, despite the low activity, show a significant positive correlation with no time lag. The HR_keV and HR_TeV show the harder-when-brighter trend observed in many blazars, but the trend flattens at the highest fluxes, which suggests a change in the processes dominating the blazar variability. Enlarging our data set with data from years 2007 to 2014, we measured a positive correlation between the optical and the GeV emission over a range of about 60 d centred at time lag zero, and a positive correlation between the optical/GeV and the radio emission over a range of about 60 d centred at a time lag of |$43^{+9}_{-6}$| d. This observation is consistent with the radio-bright zone being located about 0.2 parsec downstream from the optical/GeV emission regions of the jet. The flux distributions are better described with a lognormal function in most of the energy bands probed, indicating that the variability in Mrk 421 is likely produced by a multiplicative process., Published by Oxford Univ. Press, Oxford

47. First NuStar Observations of MRK 501 within a Radio to TeV Multi-Instrument Campaign

Author: Furniss, A., Noda, K., Boggs, S., Chiang, J., Christensen, F., Craig, W., Giommi, P., Hailey, C., Harisson, F., Madejski, G., Nalewajko, K., Perri, M., Stern, D., Urry, M., Verrecchia, F., Zhang, W., Ahnen, M. L., Ansoldi, S., Antonelli, L. A., Antoranz, P., Babic, A., Banerjee, B., Bangale, P., Barres De Almeida, U., A. Barrio, J., Becerra González, J., Bednarek, W., Bernardini, E., Biasuzzi, B., Biland, A., Blanch, O., Bonnefoy, S., Bonnoli, G., Borracci, F., Bretz, T., Carmona, E., Carosi, A., Chatterjee, A., Clavero, R., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Da Vela, P., Dazzi, F., De Angelis, A., De Caneva, G., De Lotto, B., De Oña Wilhelmi, E., Delgado Mendez, C., Di Pierro, F., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Eisenacher Glawion, D., Elsaesser, D., Fernández-Barral, A., Fidalgo, D., Fonseca, M. V., Font, L., Frantzen, K., Fruck, C., Galindo, D., García López, R. J., Garczarczyk, M., Garrido Terrats, D., Gaug, M., Giammaria, P., Godinovic´, N., González Muñoz, A., Guberman, D., Hanabata, Y., Hayashida, M., Herrera, J., Hose, J., Hrupec, D., Hughes, G., Idec, W., Kellermann, H., Kodani, K., Konno, Y., Kubo, H., Kushida, J., La Barbera, A., Lelas, D., Lewandowska, N., Lindfors, E., Lombardi, S., Longo, F., López, M., López-Coto, R., López-Oramas, A., Lorenz, E., Majumdar, P., Makariev, M., Mallot, K., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Marcote, B., Mariotti, M., Martínez, M., Mazin, D., Menzel, U., Miranda, J. M., Mirzoyan, R., Moralejo, A., Nakajima, D., Neustroev, V., Niedzwiecki, A., Nievas Rosillo, M., Nilsson, K., Nishijima, K., Orito, R., Overkemping, A., Paiano, S., Palacio, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Paredes-Fortuny, X., Persic, M., Poutanen, J., Prada Moroni, P. G., Prandini, E., Puljak, I., Reinthal, R., Rhode, W., Ribó, M., Rico, J., Rodriguez Garcia, J., Saito, T., Saito, K., Satalecka, K., Scapin, V., Schultz, C., Schweizer, T., Shore, S. N., Sillanpää, A., Sitarek, J., Snidaric, I., Sobczynska, D., Stamerra, A., Steinbring, T., Strzys, M., Takalo, L., Takami, H., Tavecchio, F., Temnikov, P., Terzic´, T., Tescaro, D., Teshima, M., Thaele, J., Torres, D. F., Toyama, T., Treves, A., Verguilov, V., Vovk, I., Will, M., Zanin, R., Archer, A., Benbow, W., Bird, R., Biteau, J., Bugaev, V., Cardenzana, J. V, Cerruti, M., Chen, Xuhui, Ciupik, L., Connolly, M. P., Cui, W., Dickinson, H. J., Dumm, J., Eisch, J. D., Falcone, A., Feng, Q., Finley, J. P., Fleischhack, H., Fortin, P., Fortson, L., Gerard, L., Gillanders, G. H., Griffin, S., Griffiths, S. T., Grube, J., Gyuk, G., Håkansson, N., Holder, J., Humensky, T. B., Johnson, C. A., Kaaret, P., Kertzman, M., Kieda, D., Krause, Maria, Krennrich, F., Lang, M. J., Lin, T. T. Y., Maier, G., McArthur, S., McCann, A., Meagher, K., Moriarty, P., Mukherjee, R., Nieto, D., O’Faoláin De Bhróit, A., Ong, R. A., Park, N., Petry, D., Pohl, Martin, Popkow, A., Ragan, K., Ratliff, G., Reyes, L. C., Reynolds, P. T., Richards, G. T., Roache, E., Santander, M., Sembroski, G. H., Shahinyan, K., Staszak, D., Telezhinsky, I., Tucci, J. V., Tyler, J., Vassiliev, V. V., Wakely, S. P., Weiner, O. M., Weinstein, A., Wilhelm, Alina, Williams, D. A., Zitzer, B., Vince, O., Fuhrmann, L., Angelakis, E., Karamanavis, V., Myserlis, I., Krichbaum, T. P., Zensus, J. A., Ungerechts, H., Sievers, A., Bachev, R., Böttcher, M., Chen, W. P., Damljanovic, G., Eswaraiah, C., Güver, T., Hovatta, T., Hughes, Z., Ibryamov, S. I., Joner, M. D., Jordan, B., Jorstad, S. G., Joshi, M., Kataoka, J., Kurtanidze, O. M., Kurtanidze, S. O., Lähteenmäki, A., Latev, G., Lin, H. C., Larionov, V. M., Mokrushina, A. A., Morozova, D. A., Nikolashvili, M. G., Raiteri, C. M., Ramakrishnan, V., R. Readhead, A. C., Sadun, A. C., Sigua, L. A., Semkov, E. H., Strigachev, A., Tammi, J., Tornikoski, M., Troitskaya, Y. V., Troitsky, I. S., and Villata, M.
Subjects: 13. Climate action
Abstract: The astrophysical journal 812(1), 65 - (2015). doi:10.1088/0004-637X/812/1/65, We report on simultaneous broadband observations of the TeV-emitting blazar Markarian 501 between 2013 April 1 and August 10, including the first detailed characterization of the synchrotron peak with Swift and NuSTAR. During the campaign, the nearby BL Lac object was observed in both a quiescent and an elevated state. The broadband campaign includes observations with NuSTAR, MAGIC, VERITAS, the Fermi Large Area Telescope, Swift X-ray Telescope and UV Optical Telescope, various ground-based optical instruments, including the GASP-WEBT program, as well as radio observations by OVRO, Metsähovi, and the F-Gamma consortium. Some of the MAGIC observations were affected by a sand layer from the Saharan desert, and had to be corrected using event-by-event corrections derived with a Light Detection and Ranging (LIDAR) facility. This is the first time that LIDAR information is used to produce a physics result with Cherenkov Telescope data taken during adverse atmospheric conditions, and hence sets a precedent for the current and future ground-based gamma-ray instruments. The NuSTAR instrument provides unprecedented sensitivity in hard X-rays, showing the source to display a spectral energy distribution (SED) between 3 and 79 keV consistent with a log-parabolic spectrum and hard X-ray variability on hour timescales. None (of the four extended NuSTAR observations) show evidence of the onset of inverse-Compton emission at hard X-ray energies. We apply a single-zone equilibrium synchrotron self-Compton (SSC) model to five simultaneous broadband SEDs. We find that the SSC model can reproduce the observed broadband states through a decrease in the magnetic field strength coinciding with an increase in the luminosity and hardness of the relativistic leptons responsible for the high-energy emission., Published by Univ.11032, Chicago, Ill. [u.a.]

48. Broadband characterisation of the very intense TeV flares of the blazar 1ES 1959+650 in 2016

Author: Acciari, V. A., Ansoldi, S., Antonelli, L. A., Arbet Engels, A., Baack, D., Babić, A., Banerjee, B., Barres De Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bellizzi, L., Bernardini, E., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Bosnjak, Z., Busetto, G., Carosi, R., Ceribella, G., Chai, Y., Cikota, S., Colak, S. M., Colin, U., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D'Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Di Pierro, F., Do Souto Espiñeira, E., Dominis Prester, D., Donini, A., Dorner, D., Doro, M., Elsaesser, D., Fallah Ramazani, V., Fattorini, A., Fernández-Barral, A., Ferrara, G., Fidalgo, D., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Fukami, S., Gallozzi, S., García López, R. J., Garczarczyk, Markus, Gasparyan, S., Gaug, M., Godinović, N., Green, D., Guberman, D., Hadasch, D., Hahn, A., Herrera, J., Hoang, J., Hrupec, D., Inada, T., Inoue, S., Ishio, K., Iwamura, Y., Jouvin, L., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., López, M., López-Coto, R., López-Oramas, A., Machado De Oliveira Fraga, B., Maggio, C., Majumdar, P., Makariev, M., Mallamaci, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Masuda, S., Mazin, D., Mićanović, S., Miceli, D., Minev, M., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Morcuende, D., Moreno, V., Moretti, E., Munar-Adrover, P., Neustroev, V., Niedzwiecki, A., Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Nöthe, M., Nozaki, S., Paiano, S., Palacio, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Peñil, P., Peresano, M., Persic, M., Prada Moroni, P. G., Prandini, E., Puljak, I., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Saito, T., Sakurai, S., Satalecka, K., Schweizer, T., Sitarek, J., Šnidarić, I., Sobczynska, D., Somero, A., Stamerra, A., Strom, D., Strzys, M., Surić, T., Takahashi, M., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Torres-Albà, N., Tsujimoto, S., Van Scherpenberg, J., Vanzo, G., Vazquez Acosta, M., Vovk, I., Will, M., Zarić, D., and Hayashida, M.
Subjects: exceptional, model: hadronic, imaging, magnetic field, 7. Clean energy, MAGIC, proton synchrotron, VHE, GLAST, blazar, flux, X-ray, p: energy, field strength, 13. Climate action, gamma ray, synchrotron, spectral, Cherenkov
Abstract: Astronomy and astrophysics 638, A14 - (2020). doi:10.1051/0004-6361/201935450, 1ES 1959+650 is a bright TeV high-frequency-peaked BL Lac object exhibiting interesting features like 'orphan' TeV flares and a broad emission in the high-energy regime, that are difficult to interpret using conventional one-zone Synchrotron Self-Compton (SSC) scenarios. We report the results from the Major Atmospheric Gamma Imaging Cherenkov (MAGIC) observations in 2016 along with the multi-wavelength data from the Fermi Large Area Telescope (LAT) and Swift instruments. MAGIC observed 1ES 1959+650 with different emission levels in the very-high-energy (VHE, E >100 GeV) gamma-ray band during 2016. In the long-term data, the X-ray spectrum becomes harder with increasing flux and a hint of a similar trend is also visible in the VHE band. An exceptionally high VHE flux reaching ~ 3 times the Crab Nebula flux was measured by MAGIC on the 13th, 14th of June and 1st July 2016 (the highest flux observed since 2002). During these flares, the high-energy peak of the spectral energy distribution (SED) lies in the VHE domain and extends up to several TeV. The spectrum in the gamma-ray (both Fermi-LAT and VHE bands) and the X-ray bands are quite hard. On 13th June and 1st July 2016, the source showed rapid variations of the VHE flux within timescales of less than an hour. A simple one-zone SSC model can describe the data during the flares requiring moderate to high values of the Doppler factors (>=30-60). Alternatively, the high-energy peak of the SED can be explained by a purely hadronic model attributed to proton-synchrotron radiation with jet power L_{jet}~10^{46} erg/s and under high values of the magnetic field strength (~100 G) and maximum proton energy (~few EeV). Mixed lepto-hadronic models require super-Eddington values of the jet power. We conclude that it is difficult to get detectable neutrino emission from the source during the extreme VHE flaring period of 2016., Published by EDP Sciences, Les Ulis

49. Multi-wavelength characterization of the blazar S5 0716+714 during an unprecedented outburst phase

Author: Ahnen, M. L., Ansoldi, S., Antonelli, L. A., Arcaro, C., Baack, D., Babić, A., Banerjee, B., Bangale, P., Barres De Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bernardini, E., Ch Berse, R., Berti, A., Bhattacharyya, W., Biland, A., Blanch, O., Bonnoli, G., Carosi, R., Carosi, A., Ceribella, G., Chatterjee, A., Colak, S. M., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Cumani, P., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Di Pierro, F., Domínguez, A., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Elsaesser, D., Fallah Ramazani, V., Fernández-Barral, A., Fidalgo, D., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., Gallozzi, S., García López, R. J., Garczarczyk, M., Gaug, M., Giammaria, P., Godinović, N., Gora, D., Guberman, D., Hadasch, D., Hahn, A., Hassan, T., Hayashida, M., Herrera, J., Hose, J., Hrupec, D., Ishio, K., Konno, Y., Kubo, H., Kushida, J., Kuveždić, D., Lelas, D., Lindfors, E., Lombardi, S., Longo, F., López, M., Maggio, C., Majumdar, P., Makariev, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Masuda, S., Mazin, D., Mielke, K., Minev, M., Miranda, J. M., Mirzoyan, R., Moralejo, A., Moreno, V., Moretti, E., Nagayoshi, T., Neustroev, V., Niedzwiecki, A., Nievas Rosillo, M., Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Paiano, S., Palacio, J., Paneque, D., Paoletti, R., Paredes, J. M., Pedaletti, G., Peresano, M., Persic, M., Prada Moroni, P. G., Prandini, E., Puljak, I., Garcia, J. R., Reichardt, I., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saito, T., Satalecka, K., Schweizer, T., Sitarek, J., Šnidarić, I., Sobczynska, D., Stamerra, A., Strzys, M., Surić, T., Takahashi, M., Takalo, L., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Torres-Albà, N., Treves, A., Tsujimoto, S., Vanzo, G., Vazquez Acosta, M., Vovk, I., Ward, J. E., Will, M., Zarić, D., Bastieri, D., Gasparrini, D., Lott, B., Rani, B., Thompson, D. J., Agudo, I., Angelakis, E., Borman, G. A., Casadio, C., Grishina, T. S., Gurwell, M., Hovatta, T., Itoh, R., Järvelä, E., Jermak, H., Jorstad, S., Kopatskaya, E. N., Kraus, A., Krichbaum, T. P., Kuin, N. P. M., Lähteenmäki, A., Larionov, V. M., Larionova, L. V., Lien, A. Y., Madejski, G., Marscher, A., Myserlis, I., Max-Moerbeck, W., Molina, S. N., Morozova, D. A., Nalewajko, K., Pearson, T. J., Ramakrishnan, V., Readhead, A. C. S., Reeves, R. A., Savchenko, S. S., Steele, I. A., Tornikoski, M., Troitskaya, Yu. V., Troitsky, I., Vasilyev, A. A., and Anton Zensus, J.
Subjects: 7. Clean energy
Abstract: Astronomy and astrophysics 619, A45 (2018). doi:10.1051/0004-6361/201832677, Context. The BL Lac object S5 0716+714, a highly variable blazar, underwent an impressive outburst in January 2015 (Phase A), followed by minor activity in February (Phase B). The MAGIC observations were triggered by the optical flux observed in Phase A, corresponding to the brightest ever reported state of the source in the R-band.Aims.The comprehensive dataset collected is investigated in order to shed light on the mechanism of the broadband emission.Methods. Multi-wavelength light curves have been studied together with the broadband spectral energy distributions (SEDs). The sample includes data from Effelsberg, OVRO, Metsähovi, VLBI, CARMA, IRAM, SMA, Swift-UVOT, KVA, Tuorla, Steward, RINGO3, KANATA, AZT-8+ST7, Perkins, LX-200, Swift-XRT, NuSTAR, Fermi-LAT and MAGIC.Results. The flaring state of Phase A was detected in all the energy bands, providing for the first time a multi-wavelength sample of simultaneous data from the radio band to the very-high-energy (VHE, E > 100 GeV). In the constructed SED, the Swift-XRT+NuSTAR data constrain the transition between the synchrotron and inverse Compton components very accurately, while the second peak is constrained from 0.1 GeV to 600 GeV by Fermi+MAGIC data. The broadband SED cannot be described with a one-zone synchrotron self-Compton model as it severely underestimates the optical flux in order to reproduce the X-ray to γ-ray data. Instead we use a two-zone model. The electric vector position angle (EVPA) shows an unprecedented fast rotation. An estimation of the redshift of the source by combined high-energy (HE, 0.1 GeV < E < 100 GeV) and VHE data provides a value of z = 0.31 ± 0.02$_{stats}$ ± 0.05$_{sys}$, confirming the literature value.Conclusions. The data show the VHE emission originating in the entrance and exit of a superluminal knot in and out of a recollimation shock in the inner jet. A shock–shock interaction in the jet seems responsible for the observed flares and EVPA swing. This scenario is also consistent with the SED modeling., Published by EDP Sciences, Les Ulis

50. MAGIC observations of the microquasar V404 Cygni during the 2015 outburst

Author: Ahnen, M. L., Ansoldi, S., Antonelli, L. A., Arcaro, C., Babić, A., Banerjee, B., Bangale, P., Barres De Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bernardini, E., Berti, A., Biasuzzi, B., Biland, A., Blanch, O., Bonnefoy, S., Bonnoli, G., Carosi, R., Carosi, A., Chatterjee, A., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Cumani, P., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., De Oña Wilhelmi, E., Di Pierro, F., Doert, M., Domínguez, A., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Eisenacher Glawion, D., Elsaesser, D., Engelkemeier, M., Fallah Ramazani, V., Fernández-Barral, A., Fidalgo, D., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., García López, R. J., Garczarczyk, Markus, Gaug, M., Giammaria, P., Godinović, N., Gora, D., Griffiths, S., Guberman, D., Hadasch, D., Hahn, A., Hassan, T., Hayashida, M., Herrera, J., Hose, J., Hrupec, D., Hughes, G., Ishio, K., Konno, Y., Kubo, H., Kushida, J., Kuveždić, D., Lelas, D., Lindfors, E., Lombardi, S., Longo, F., López, M., Maggio, C., Majumdar, P., Makariev, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Mazin, D., Menzel, U., Minev, M., Mirzoyan, R., Moralejo, A., Moreno, V., Moretti, E., Neustroev, V., Niedzwiecki, A., Nievas Rosillo, M., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Paiano, S., Palacio, J., Paneque, D., Paoletti, R., Paredes, J. M., Paredes-Fortuny, X., Pedaletti, G., Peresano, M., Perri, L., Persic, M., Prada Moroni, P. G., Prandini, E., Puljak, I., Garcia, J. R., Reichardt, I., Rhode, W., Ribó, M., Rico, J., Saito, T., Satalecka, K., Schroeder, S., Schweizer, T., Sillanpää, A., Sitarek, J., Šnidarić, I., Sobczynska, D., Stamerra, A., Strzys, M., Surić, T., Takalo, L., Tavecchio, F., Temnikov, P., Terzić, T., Tescaro, D., Teshima, M., Torres, D. F., Torres-Albà, N., Treves, A., Vanzo, G., Vazquez Acosta, M., Vovk, I., Ward, J. E., Will, M., Zarić, D., Loh, A., and Rodriguez, J.
Subjects: radio wave, exceptional, opacity, acceleration, 7. Clean energy, MAGIC, GLAST, VHE, X-ray, gamma ray, flux: upper limit, quasar, burst
Abstract: Monthly notices of the Royal Astronomical Society 471(2), 1688 - 1693 (2017). doi:10.1093/mnras/stx1690, The microquasar V404 Cygni underwent a series of outbursts in 2015, June 15–31, during which its flux in hard X-rays (20–40 keV) reached about 40 times the Crab nebula flux. Because of the exceptional interest of the flaring activity from this source, observations at several wavelengths were conducted. The MAGIC telescopes, triggered by the INTEGRAL alerts, followed-up the flaring source for several nights during the period June 18–27, for more than 10 h. One hour of observation was simultaneously conducted on a giant 22 GHz radio flare and a hint of signal at GeV energies seen by Fermi-LAT. The MAGIC observations did not show significant emission in any of the analysed time intervals. The derived flux upper limit, in the energy range 200–1250 GeV, is 4.8 × 10$^{−12}$ photons cm$^{−2}$ s$^{−1}$. We estimate the gamma-ray opacity during the flaring period, which along with our non-detection points to an inefficient acceleration in the V404 Cyg jets if a very high energy emitter is located further than 1 × 10$^{10}$ cm from the compact object., Published by Oxford Univ. Press, Oxford

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