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1. Multiwavelength study of the gravitationally lensed blazar QSO B0218+357 between 2016 and 2020

Author: MAGIC Collaboration, 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., Bonnoli, G., 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, M., 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., Zari��, D., de Palma, F., D'Ammando, F., Barnacka, A., Sahu, D. K., Hodges, M., Hovatta, T., Kiehlmann, S., Max-Moerbeck, W., Readhead, A. C. S., Reeves, R., Pearson, T. J., L��hteenm��ki, A., Bj��rklund, I., Tornikoski, M., Tammi, J., Suutarinen, S., Hada, K., Niinuma, K., Acciari, V. A., Ansoldi, S., Antonelli, L. A., Arbet Engels, A., Artero, M., Asano, K., Baack, D., Babic, A., Baquero, A., Barres De Almeida, U., Barrio, J. A., Batkovic, I., 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 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., 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, J. G., Green, D., Hadasch, D., Hahn, A., Heckmann, L., Herrera, J., Hoang, J., Hrupec, D., Hutten, M., Inada, T., Inoue, S., Ishio, K., Iwamura, Y., JimCrossed D SignCopyrightnez, 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., Lopez-Coto, R., Lopez-Moya, M., 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., Menchiari, S., 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., 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., 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., Saturni, F. G., 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., Tosti, L., Truzzi, S., Tutone, A., Ubach, S., Van Scherpenberg, J., Vanzo, G., Vazquez Acosta, M., Ventura, S., Verguilov, V., Vigorito, C. F., Vitale, V., Vovk, I., Will, M., Wunderlich, C., Zaric, D., De Palma, F., D'Ammando, F., Barnacka, A., Sahu, D. K., Hodges, M., Hovatta, T., Kiehlmann, S., Max-Moerbeck, W., Readhead, A. C. S., Reeves, R., Pearson, T. J., Lahteenmaki, A., Bjorklund, I., Tornikoski, M., Tammi, J., Suutarinen, S., Hada, K., Niinuma, K., Metsähovi Radio Observatory, Department of Electronics and Nanoengineering, School common, ELEC, Aalto-yliopisto, Aalto University, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Ministerio de Economía y Competitividad (España), Swiss National Science Foundation, European Commission, European Research Council, Japan Society for the Promotion of Science, National Aeronautics and Space Administration (US), and Generalitat de Catalunya
Subjects: RADIO-SOURCES, gamma-rays: galaxies, individual: QSO B0218+357 [quasars], astro-ph.GA, Astrophysics::High Energy Astrophysical Phenomena, jets [galaxies], FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, VLBI OBSERVATIONS, 01 natural sciences, LARGE-AREA TELESCOPE, Gamma rays: galaxies – Gravitational lensing: strong – Galaxies: jets – Radiation mechanisms: non- thermal – quasars: individual: QSO B0218+357, 0103 physical sciences, ABSORPTION, Blazar, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, XMM-NEWTON, astro-ph.HE, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), galaxies: jets, gravitational lensing: strong, quasars: individual: QSO B0218+357, radiation mechanisms: non-thermal, 010308 nuclear & particles physics, TIME-DELAY, POINT-SOURCE CATALOG, Astronomy and Astrophysics, non-thermal [radiation mechanisms], Astrophysics - Astrophysics of Galaxies, GALAXIES, galaxies [gamma-rays], Space and Planetary Science, strong [gravitational lensing], Astrophysics of Galaxies (astro-ph.GA), gravitational lensing: strong radiation mechanisms: non-thermalgalaxies: jetsquasars: individual: QSO B0218+357gamma-rays: galaxies, ddc:520, Astrophysics - High Energy Astrophysical Phenomena, GAMMA-RAY EMISSION, SYSTEM
Abstract: V. A. Acciari et al., We report multiwavelength observations of the gravitationally lensed blazar QSO B0218+357 in 2016–2020. Optical, X-ray, and GeV flares were detected. The contemporaneous MAGIC observations do not show significant very high energy (VHE; ≳100 GeV) gamma-ray emission. The lack of enhancement in radio emission measured by The Owens Valley Radio Observatory indicates the multizone nature of the emission from this object. We constrain the VHE duty cycle of the source to be, The financial support of the German BMBF, MPG, and HGF; the Italian INFN and INAF; the Swiss National Fund SNF; the ERDF under the Spanish Ministerio de Ciencia e Innovación (MICINN) (FPA2017-87859-P, FPA2017-85668-P, FPA2017-82729-C6-5-R, FPA2017-90566-REDC, PID2019-104114RB-C31, PID2019-104114RB-C32, PID2019-105510GB-C31, PID2019-107847RB-C41, PID2019-107847RB-C42, PID2019-107988GB-C22); the Indian Department of Atomic Energy; the Japanese ICRR, the University of Tokyo, JSPS, and MEXT; the Bulgarian Ministry of Education and Science, National RI Roadmap Project DO1-268/16.12.2019 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-2016-0588 and CEX2019-000920-S, and ‘María de Maeztu’ CEX2019-000918-M, the Unidad de Excelencia ‘María de Maeztu’ MDM-2015-0509-18-2 and the ‘la Caixa’ Foundation (fellowship LCF/BQ/PI18/11630012) and by the CERCA program of the Generalitat de Catalunya; by the Croatian Science Foundation (HrZZ) Project IP-2016-06-9782 and the University of Rijeka Project uniri-prirod-18-48; by the DFG Collaborative Research Centers SFB823/C4 and SFB876/C3; the Polish National Research Centre grant UMO-2016/22/M/ST9/00382; and by the Brazilian MCTIC, CNPq, and FAPERJ. The Fermi LAT Collaboration acknowledges generous ongoing support from a number of agencies and institutes that have supported both the development and the operation of the LAT as well as scientific data analysis. These include the National Aeronautics and Space Administration and the Department of Energy in the United States, the Commissariat à l’Energie Atomique and the Centre National de la Recherche Scientifique / Institut National de Physique Nucléaire et de Physique des Particules in France, the Agenzia Spaziale Italiana and the Istituto Nazionale di Fisica Nucleare in Italy, the Ministry of Education, Culture, Sports, Science and Technology (MEXT), High Energy Accelerator Research Organization (KEK) and Japan Aerospace Exploration Agency (JAXA) in Japan, and the K. A. Wallenberg Foundation, the Swedish Research Council and the Swedish National Space Board in Sweden. Additional support for science analysis during the operations phase is gratefully acknowledged from the Istituto Nazionale di Astrofisica in Italy and the Centre National d’Études Spatiales in France. This work performed in part under DOE Contract DE-AC02-76SF00515. We thank Director of Indian Institute of Astrophysics for allotting us observing time with HCT under DDT. We also thank the staff of IAO, Hanle and CREST, Hosakote, that made HCT observations possible. The facilities at IAO and CREST are operated by the Indian Institute of Astrophysics, Bangalore. The Joan Oró Telescope (TJO) of the Montsec Astronomical Observatory (OAdM) is owned by the Catalan Government and operated by the Institute for Space Studies of Catalonia (IEEC). This research has made use of data from the OVRO 40-m monitoring program which was supported in part by NASA grants NNX08AW31G, NNX11A043G, and NNX14AQ89G, and NSF grants AST-0808050 and AST-1109911, and private funding from Caltech and the MPIfR. SK acknowledges support from the European Research Council (ERC) under the European Unions Horizon 2020 research and innovation programme under grant agreement No. 771282. This research has made use of the NASA/IPAC Extragalactic Database (NED), which is funded by the National Aeronautics and Space Administration and operated by the California Institute of Technology. This publication makes use of data obtained at the Metsähovi Radio Observatory, operated by Aalto University in Finland. Part of this work is based on archival data, software or online services provided by the Space Science Data Center - ASI.
Published: 2021
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2. A search for optical and near-infrared counterparts of the compact binary merger GW190814

Author: Thakur, A. L., Dichiara, S., Troja, E., Chase, E. A., Sanchez-Ramirez, R., Piro, L., Fryer, C. L., Butler, N. R., Watson, A. M., Wollaeger, R. T., Ambrosi, E., Gonz��lez, J. Becerra, Becerra, R. L., Bruni, G., Cenko, S. B., Cusumano, G., D'A��, Antonino, Durbak, J., Fontes, C. J., Gatkine, P., Hungerford, A. L., Korobkin, O., Kutyrev, A. S., Lee, W. H., Lotti, S., Minervini, G., Novara, G., La Parola, V., Pereyra, M., Ricci, R., Tiengo, A., and Veilleux, S.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics::Galaxy Astrophysics
Abstract: We report on our observing campaign of the compact binary merger GW190814, detected by the Advanced LIGO and Advanced Virgo detectors on August 14th, 2019. This signal has the best localisation of any observed gravitational wave (GW) source, with a 90% probability area of 18.5 deg$^2$, and an estimated distance of ~ 240 Mpc. We obtained wide-field observations with the Deca-Degree Optical Transient Imager (DDOTI) covering 88% of the probability area down to a limiting magnitude of $w$ = 19.9 AB. Nearby galaxies within the high probability region were targeted with the Lowell Discovery Telescope (LDT), whereas promising candidate counterparts were characterized through multi-colour photometry with the Reionization and Transients InfraRed (RATIR) and spectroscopy with the Gran Telescopio de Canarias (GTC). We use our optical and near-infrared limits in conjunction with the upper limits obtained by the community to constrain the possible electromagnetic counterparts associated with the merger. A gamma-ray burst seen along its jet's axis is disfavoured by the multi-wavelength dataset, whereas the presence of a burst seen at larger viewing angles is not well constrained. Although our observations are not sensitive to a kilonova similar to AT2017gfo, we can rule out high-mass (> 0.1 M$_{\odot}$) fast-moving (mean velocity >= 0.3c) wind ejecta for a possible kilonova associated with this merger., 17 pages, 11 figures, 5 tables; updated acknowledgement section. Accepted for publication in MNRAS (10 September 2020)
Published: 2020

3. The Great Markarian 421 Flare of February 2010: Multiwavelength variability and correlation studies

Author: Abeysekara, A. U., Benbow, W., Bird, R., Brill, A., Brose, R., Buchovecky, M., Buckley, J. H., Christiansen, J. L., Chromey, A. J., Daniel, M. K., Dumm, J., Falcone, A., Feng, Q., Finley, J. P., Fortson, L., Furniss, A., Galante, N., Gent, A., Gillanders, G. H., Giuri, C., Gueta, O., Hassan, T., Hervet, O., Holder, J., Hughes, G., Humensky, T. B., Johnson, C. A., Kaaret, P., Kar, P., Kelley-Hoskins, N., Kertzman, M., Kieda, D., Krause, M., Krennrich, F., Kumar, S., Lang, M. J., Moriarty, P., Mukherjee, R., Nelson, T., Nieto, D., Nievas-Rosillo, M., O'Brien, S., Ong, R. A., Otte, A. N., Park, N., Petrashyk, A., Pichel, A., Pohl, M., Prado, R. R., Pueschel, E., 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., Stevenson, B., Sushch, I., Tyler, J., Vassiliev, V. V., Wakely, S. P., Weinstein, A., Wells, R. M., Wilcox, P., Wilhelm, A., Williams, D. A., Zitzer, B., Acciari, V. A., Ansoldi, S., Antonelli, L. A., Engels, A. Arbet, Baack, D., Babi��, A., Banerjee, B., de Almeida, U. Barres, Barrio, J. A., Gonz��lez, J. Becerra, Bednarek, W., Bellizzi, L., Bernardini, E., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., 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., Espi��era, E. Do Souto, Prester, D. Dominis, Dorner, D., Doro, M., Einecke, S., Elsaesser, D., Ramazani, V. Fallah, Fattorini, A., Fern��ndez-Barral, A., Ferrara, G., Fidalgo, D., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., Gallozzi, S., L��pez, R. J. Garc��a, Garczarczyk, M., Gasparyan, S., Gaug, M., Godinovi��, 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., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., L��pez, M., L��pez-Coto, R., L��pez-Oramas, A., 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., Masuda, S., Mazin, D., 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., Rosillo, M. Nievas, Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogu��s, L., N��the, M., Paiano, S., Palacio, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Pe��il, P., Peresano, M., Persic, M., Moroni, P. G. Prada, Prandini, E., Puljak, I., Rhode, W., Rib��, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Sahakyan, N., Saito, T., Satalecka, K., Schweizer, T., Sitarek, J., ��nidari��, I., Sobczynska, D., Somero, A., Stamerra, A., Strom, D., Strzys, M., Sun, S., Suri��, T., Tavecchio, F., Temnikov, P., Terzi��, T., Teshima, M., Torres-Alb��, N., Tsujimoto, S., van Scherpenberg, J., Vanzo, G., Acosta, M. Vazquez, Vovk, I., Will, M., Zari��, D., Aller, H. D., Aller, M. F., Carini, M. T., Horan, D., Jordan, B., Jorstad, Svetlana G., Kurtanidze, O. M., Kurtanidze, S. O., L��hteenm��ki, A., Larionov, V. M., Larionova, E. G., Madejski, G., Marscher, Alan P., Max-Moerbeck, W., Moody, J. Ward, Morozova, D. A., Nikolashvili, M. G., Raiteri, C. M., Readhead, A. C. S., Richards, J. L., Sadun, Alberto C., Sakamoto, T., Sigua, L. A., Smith, P. S., Talvikki, H., Tammi, J., Tornikoski, M., Troitsky, I. S., Villata, M., Laboratoire Leprince-Ringuet (LLR), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), VERITAS, and MAGIC
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - High Energy Astrophysical Phenomena
Abstract: We report on variability and correlation studies using multiwavelength observations of the blazar Mrk 421 during the month of February, 2010 when an extraordinary flare reaching a level of $\sim$27~Crab Units above 1~TeV was measured in very-high-energy (VHE) $\gamma$-rays with the VERITAS observatory. This is the highest flux state for Mrk 421 ever observed in VHE $\gamma$-rays. Data are analyzed from a coordinated campaign across multiple instruments including VHE $\gamma$-ray (VERITAS, MAGIC), high-energy (HE) $\gamma$-ray (Fermi-LAT), X-ray (Swift}, RXTE, MAXI), optical (including the GASP-WEBT collaboration and polarization data) and radio (Mets\"ahovi, OVRO, UMRAO). Light curves are produced spanning multiple days before and after the peak of the VHE flare, including over several flare `decline' epochs. The main flare statistics allow 2-minute time bins to be constructed in both the VHE and optical bands enabling a cross-correlation analysis that shows evidence for an optical lag of $\sim$25-55 minutes, the first time-lagged correlation between these bands reported on such short timescales. Limits on the Doppler factor ($\delta \gtrsim 33$) and the size of the emission region ($ \delta^{-1}R_B \lesssim 3.8\times 10^{13}\,\,\mbox{cm}$) are obtained from the fast variability observed by VERITAS during the main flare. Analysis of 10-minute-binned VHE and X-ray data over the decline epochs shows an extraordinary range of behavior in the flux-flux relationship: from linear to quadratic to lack of correlation to anti-correlation. Taken together, these detailed observations of an unprecedented flare seen in Mrk 421 are difficult to explain by the classic single-zone synchrotron self-Compton model., Comment: 41 pages including 3 appendices, 13 figures; version accepted to Astrophysical Journal
Published: 2020

4. Teraelectronvolt emission from the $��$-ray burst GRB 190114C

Author: MAGIC Collaboration, Acciari, V. A., Ansoldi, S., Antonelli, L. A., Engels, A. Arbet, Baack, D., Babi��, A., Banerjee, B., de Almeida, U. Barres, Barrio, J. A., Gonz��lez, J. Becerra, Bednarek, W., Bellizzi, L., Bernardini, E., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Bo��njak, ��., Busetto, G., Carosi, A., 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'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., Espi��eira, E. Do Souto, Prester, D. Dominis, Donini, A., Dorner, D., Doro, M., Elsaesser, D., Ramazani, V. Fallah, Fattorini, A., Fern��ndez-Barral, A., Ferrara, G., Fidalgo, D., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Fukami, S., Gallozzi, S., L��pez, R. J. Garc��a, Garczarczyk, M., Gasparyan, S., Gaug, M., Giglietto, N., Giordano, F., Godinovi��, N., Green, D., Guberman, D., Hadasch, D., Hahn, A., Herrera, J., Hoang, J., Hrupec, D., H��tten, 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., L��pez, M., L��pez-Coto, R., 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., Masuda, S., Mazin, D., Mi��anovi��, 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., Nogu��s, L., N��the, M., Nozaki, S., Paiano, S., Palacio, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Pe��il, P., Peresano, M., Persic, M., Moroni, P. G. Prada, Prandini, E., Puljak, I., Rhode, W., Rib��, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Sahakyan, N., Saito, T., Sakurai, S., Satalecka, K., Schmidt, K., Schweizer, T., Sitarek, J., ��nidari��, I., Sobczynska, D., Somero, A., Stamerra, A., Strom, D., Strzys, M., Suda, Y., Suri��, T., Takahashi, M., Tavecchio, F., Temnikov, P., Terzi��, T., Teshima, M., Torres-Alb��, N., Tosti, L., Tsujimoto, S., Vagelli, V., van Scherpenberg, J., Vanzo, G., Acosta, M. Vazquez, Vigorito, C. F., Vitale, V., Vovk, I., Will, M., Zari��, D., and Nava, L.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: Gamma-ray bursts (GRBs) of the long-duration class are the most luminous sources of electromagnetic radiation known in the Universe. They are generated by outflows of plasma ejected at near the speed of light by newly formed neutron stars or black holes of stellar mass at cosmological distances. Prompt flashes of MeV gamma rays are followed by longer-lasting afterglow emission from radio waves to GeV gamma rays, due to synchrotron radiation by energetic electrons in accompanying shock waves. Although emission of gamma rays at even higher, TeV energies by other radiation mechanisms had been theoretically predicted, it had never been detected previously. Here we report the clear detection of GRB 190114C in the TeV band, achieved after many years of dedicated searches for TeV emission from GRBs. Gamma rays in the energy range 0.2--1 TeV are observed from about 1 minute after the burst (at more than 50 standard deviations in the first 20 minutes). This unambiguously reveals a new emission component in the afterglow of a GRB, whose power is comparable to that of the synchrotron component. The observed similarity in the radiated power and temporal behaviour of the TeV and X-ray bands points to processes such as inverse Compton radiation as the mechanism of the TeV emission, while processes such as synchrotron emission by ultrahigh-energy protons are disfavoured due to their low radiative efficiency.
Published: 2020
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5. Observation of inverse Compton emission from a long $��$-ray burst

Author: Acciari, V. A., Ansoldi, S., Antonelli, L. A., Engels, A. Arbet, Baack, D., Babi��, A., Banerjee, B., de Almeida, U. Barres, Barrio, J. A., Gonz��lez, J. Becerra, Bednarek, W., Bellizzi, L., Bernardini, E., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Bo��njak, ��., 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., Espi��eira, E. Do Souto, 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., L��pez, R. J. Garc��a, Garczarczyk, M., Gasparyan, S., Gaug, M., Giglietto, N., Giordano, F., Godinovi��, N., Green, D., Guberman, D., Hadasch, D., Hahn, A., Herrera, J., Hoang, J., Hrupec, D., H��tten, 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., L��pez, M., L��pez-Coto, R., 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., Mi��anovi��, 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., Nogu��s, L., Nozaki, S., Paiano, S., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Pe��il, P., Peresano, M., Persic, M., Moroni, P. G. Prada, Prandini, E., Puljak, I., Rhode, W., Rib��, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Sahakyan, N., Saito, T., Sakurai, S., Satalecka, K., Schmidt, K., Schweizer, T., Sitarek, J., ��nidari��, I., Sobczynska, D., Somero, A., Stamerra, A., Strom, D., Strzys, M., Suda, Y., Suri��, T., Takahashi, M., Tavecchio, F., Temnikov, P., Terzi��, T., Teshima, M., Torres-Alb��, N., Tosti, L., Vagelli, V., van Scherpenberg, J., Vanzo, G., Acosta, M. Vazquez, Vigorito, C. F., Vitale, V., Vovk, I., Will, M., Zari��, D., Nava, L., Veres, P., Bhat, P. N., Briggs, M. S., Cleveland, W. H., Hamburg, R., Hui, C. M., Mailyan, B., Preece, R. D., Roberts, O., von Kienlin, A., Wilson-Hodge, C. A., Kocevski, D., Arimoto, M., Tak, D., Asano, K., Axelsson, M., Barbiellini, G., Bissaldi, E., Dirirsa, F. Fana, Gill, R., Granot, J., McEnery, J., Razzaque, S., Piron, F., Racusin, J. L., Thompson, D. J., Campana, S., Bernardini, M. G., Kuin, N. P. M., Siegel, M. H., Cenko, S. Bradley, O'Brien, P., Capalbi, M., D'A��, A., De Pasquale, M., Gropp, J., Klingler, N., Osborne, J. P., Perri, M., Starling, R., Tagliaferri, G., Tohuvavohu, A., Ursi, A., Tavani, M., Cardillo, M., Casentini, C., Piano, G., Evangelista, Y., Verrecchia, F., Pittori, C., Lucarelli, F., Bulgarelli, A., Parmiggiani, N., Anderson, G. E., Anderson, J. P., Bernardi, G., Bolmer, J., Caballero-Garc��a, M. D., Carrasco, I. M., Castell��n, A., Segura, N. Castro, Castro-Tirado, A. J., Cherukuri, S. V., Cockeram, A. M., D'Avanzo, P., Di Dato, A., Diretse, R., Fender, R. P., Fern��ndez-Garc��a, E., Fynbo, J. P. U., Fruchter, A. S., Greiner, J., Gromadzki, M., Heintz, K. E., Heywood, I., van der Horst, A. J., Hu, Y. -D., Inserra, C., Izzo, L., Jaiswal, V., Jakobsson, P., Japelj, J., Kankare, E., Kann, D. A., Kouveliotou, C., Klose, S., Levan, A. J., Li, X. Y., Lotti, S., Maguire, K., Malesani, D. B., Manulis, I., Marongiu, M., Martin, S., Melandri, A., Micha��owski, M., Miller-Jones, J. C. A., Misra, K., Moin, A., Mooley, K. P., Nasri, S., Nicholl, M., Noschese, A., Novara, G., Pandey, S. B., Peretti, E., del Pulgar, C. J. P��rez, P��rez-Torres, M. A., Perley, D. A., Piro, L., Ragosta, F., Resmi, L., Ricci, R., Rossi, A., S��nchez-Ram��rez, R., Selsing, J., Schulze, S., Smartt, S. J., Smith, I. A., Sokolov, V. V., Stevens, J., Tanvir, N. R., Th��ne, C. C., Tiengo, A., Tremou, E., Troja, E., Postigo, A. de Ugarte, Vergani, S. D., Wieringa, M., Woudt, P. A., Xu, D., Yaron, O., and Young, D. R.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: Long-duration gamma-ray bursts (GRBs) originate from ultra-relativistic jets launched from the collapsing cores of dying massive stars. They are characterised by an initial phase of bright and highly variable radiation in the keV-MeV band that is likely produced within the jet and lasts from milliseconds to minutes, known as the prompt emission. Subsequently, the interaction of the jet with the external medium generates external shock waves, responsible for the afterglow emission, which lasts from days to months, and occurs over a broad energy range, from the radio to the GeV bands. The afterglow emission is generally well explained as synchrotron radiation by electrons accelerated at the external shock. Recently, an intense, long-lasting emission between 0.2 and 1 TeV was observed from the GRB 190114C. Here we present the results of our multi-frequency observational campaign of GRB~190114C, and study the evolution in time of the GRB emission across 17 orders of magnitude in energy, from $5\times10^{-6}$ up to $10^{12}$\,eV. We find that the broadband spectral energy distribution is double-peaked, with the TeV emission constituting a distinct spectral component that has power comparable to the synchrotron component. This component is associated with the afterglow, and is satisfactorily explained by inverse Compton upscattering of synchrotron photons by high-energy electrons. We find that the conditions required to account for the observed TeV component are not atypical, supporting the possibility that inverse Compton emission is commonly produced in GRBs.
Published: 2020
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6. Detection of the Geminga pulsar with MAGIC hints at a power-law tail emission beyond 15 GeV

Author: MAGIC Collaboration, Acciari, V. A., Ansoldi, S., Antonelli, L. A., Engels, A. Arbet, Asano, K., Baack, D., Babi��, A., Baquero, A., de Almeida, U. Barres, Barrio, J. A., Gonz��lez, J. Becerra, Bednarek, W., Bellizzi, L., Bernardini, E., Bernardos, M., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., 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 Girolamo, T., Di Pierro, F., Di Venere, L., neira, E. Do Souto Espi, Prester, D. Dominis, Donini, A., Dorner, D., Doro, M., Elsaesser, D., Ramazani, V. Fallah, Fattorini, A., Ferrara, G., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Fukami, S., L��pez, R. J. Garc��a, Garczarczyk, M., 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., 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., 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., 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., Pavleti��, L., nil, P. Pe, 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., Torres-Alb��, N., Tosti, L., Truzzi, S., Tutone, A., van Scherpenberg, J., Vanzo, G., Acosta, M. Vazquez, Ventura, S., Verguilov, V., Vigorito, C. F., Vitale, V., Vovk, I., Will, M., Zari��, D., Hirotani, K., Parkinson, P. M. Saz, Acciari, V. A., Ansoldi, S., Antonelli, L. A., Arbet Engels, A., Asano, K., Baack, D., Babic, A., 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, J. G., Green, D., Hadasch, D., Hahn, A., Heckmann, L., Herrera, J., Hoang, J., Hrupec, D., Hutten, 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., Lopez-Coto, R., Lopez-Moya, M., 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., Saturni, F. G., 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., Tutone, A., Van Scherpenberg, J., Vanzo, G., Vazquez Acosta, M., Ventura, S., Verguilov, V., Vigorito, C. F., Vitale, V., Vovk, I., Will, M., Zaric, D., Hirotani, K., Saz Parkinson, P. M., German Research Foundation, Japan Society for the Promotion of Science, Ministry of Education, Culture, Sports, Science and Technology (Japan), Academy of Finland, Federal Ministry of Education and Research (Germany), Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brasil), Chinese University of Hong Kong, Istituto Nazionale di Fisica Nucleare, Croatian Science Foundation, Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro, University of Tokyo, Istituto Nazionale di Astrofisica, European Commission, Ministério da Ciência, Tecnologia e Inovação (Brasil), and The Government of the Hong Kong Special Administrative Region
Subjects: Gamma rays: stars, Pulsars: general, Pulsars: individual: Geminga, Pulsars: individual: PSR J0633+1746, Inverse, Astrophysics, gamma ray: pulsed, GeV, power spectrum, 01 natural sciences, Power law, rotation, MAGIC (telescope), 010303 astronomy & astrophysics, pulsar, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Spectral index, Range (particle radiation), pulsed [gamma ray], gamma rays: stars, pulsars: general, pulsars: individual: PSR J0633+1746, pulsars: individual: Geminga, stars [gamma rays], gamma ray: emission, inverse [Compton scattering], quality, curvature, Física nuclear, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics::High Energy Astrophysical Phenomena, general [Pulsars], gap, FOS: Physical sciences, Radiation, GLAST, star [Gamma rays], Pulsar, emission [gamma ray], 0103 physical sciences, 010308 nuclear & particles physics, Computer Science::Information Retrieval, Compton scattering, individual: Geminga [Pulsars], Astronomy and Astrophysics, individual: PSR J0633+1746 [Pulsars], sensitivity, MAGIC, Compton scattering: inverse, Space and Planetary Science, ddc:520
Abstract: Astronomy and astrophysics 643, L14 (1-6) (2020). doi:10.1051/0004-6361/202039131, We report the detection of pulsed gamma-ray emission from the Geminga pulsar (PSR J0633+1746) between 15 GeV and 75 GeV. This is the first time a middle-aged pulsar has been detected up to these energies. Observations were carried out with the MAGIC telescopes between 2017 and 2019 using the low-energy threshold Sum-Trigger-II system. After quality selection cuts, ∼80 h of observational data were used for this analysis. To compare with the emission at lower energies below the sensitivity range of MAGIC, 11 years of Fermi-LAT data above 100 MeV were also analysed. From the two pulses per rotation seen by Fermi-LAT, only the second one, P2, is detected in the MAGIC energy range, with a significance of 6.3$σ$. The spectrum measured by MAGIC is well-represented by a simple power law of spectral index $Γ$ = 5.62 ± 0.54, which smoothly extends the Fermi-LAT spectrum. A joint fit to MAGIC and Fermi-LAT data rules out the existence of a sub-exponential cut-off in the combined energy range at the 3.6$σ$ significance level. The power-law tail emission detected by MAGIC is interpreted as the transition from curvature radiation to Inverse Compton Scattering of particles accelerated in the northern outer gap., Published by EDP Sciences, Les Ulis
Published: 2020

7. Quasi-periodic behaviour in the optical and ��-ray light curves of blazars 3C 66A and B2 1633+38

Author: Otero-Santos, J., Acosta-Pulido, J. A., Gonz��lez, J. Becerra, Raiteri, C. M., Larionov, V. M., Pe��il, P., Smith, P. S., Niebla, C. Ballester, Borman, G. A., Carnerero, M. I., Segura, N. Castro, Grishina, T. S., Kopatskaya, E. N., Larionova, E. G., Morozova, D. A., Nikiforova, A. A., Savchenko, S. S., Troitskaya, Yu. V., Troitsky, I. S., Vasilyev, A. A., and Villata, M.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), FOS: Physical sciences
Abstract: We report on quasi-periodic variability found in two blazars included in the Steward Observatory Blazar Monitoring data sample: the BL Lac object 3C 66A and the Flat Spectrum Radio Quasar B2 1633+38. We collect optical photometric and polarimetric data in V and R bands of these sources from different observatories: St. Petersburg University, Crimean Astrophysical Observatory, WEBT-GASP, Catalina Real-Time Transient Survey, Steward Observatory, STELLA Robotic Observatory and Katzman Automatic Imaging Telescope. In addition, an analysis of the $��$-ray light curves from $\textit{Fermi}$-LAT is included. Three methods are used to search for any periodic behaviour in the data: the Z-transform Discrete Correlation Function, the Lomb-Scargle periodogram and the Weighted Wavelet Z-transform. We find evidences of possible quasi-periodic variability in the optical photometric data of both sources with periods of $\sim$3 years for 3C 66A and $\sim$1.9 years for B2 1633+38, with significances between 3$��$ and 5$��$. Only B2 1633+38 shows evidence of this behaviour in the optical polarized data set at a confidence level of 2$��$-4$��$. This is the first reported evidence of quasi-periodic behaviour in the optical light curve of B2 1633+38. Also a hint of quasi-periodic behaviour is found in the $��$-ray light curve of B2 1633+38 with a confidence level $\geqslant$2$��$, while no periodicity is observed for 3C 66A in this energy range. We propose different jet emission models that could explain the quasi-periodic variability and the differences found between these two sources., Accepted for publication in MNRAS
Published: 2020
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8. MAGIC observations of the diffuse $��$-ray emission in the vicinity of the Galactic Centre

Author: MAGIC Collaboration, Acciari, V. A., Ansoldi, S., Antonelli, L. A., Engels, A. Arbet, Baack, D., Babi��, A., Banerjee, B., de Almeida, U. Barres, Barrio, J. A., Gonz��lez, J. Becerra, Bednarek, W., Bellizzi, L., Bernardini, E., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Bo��njak, ��., 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., Espi��eira, E. Do Souto, Prester, D. Dominis, Donini, A., Dorner, D., Doro, M., Elsaesser, D., Ramazani, V. Fallah, Fattorini, A., Fern��ndez-Barral, A., Ferrara, G., Fidalgo, D., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Fukami, S., L��pez, R. J. Garc��a, Garczarczyk, M., Gasparyan, S., Gaug, M., Giglietto, N., Giordano, F., Godinovi��, N., Green, D., Guberman, D., Hadasch, D., Hahn, A., Herrera, J., Hoang, J., Hrupec, D., H��tten, 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., L��pez, M., L��pez-Coto, R., 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., Masuda, S., Mazin, D., Mi��anovi��, 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., Nogu��s, L., N��the, M., Nozaki, S., Paiano, S., Palacio, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Pe��il, P., Peresano, M., Persic, M., Moroni, P. G. Prada, Prandini, E., Puljak, I., Rhode, W., Rib��, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Sahakyan, N., Saito, T., Sakurai, S., Satalecka, K., Schmidt, K., Schweizer, T., Sitarek, J., ��nidari��, I., Sobczynska, D., Somero, A., Stamerra, A., Strom, D., Strzys, M., Suda, Y., Suri��, T., Takahashi, M., Tavecchio, F., Temnikov, P., Terzi��, T., Teshima, M., Torres-Alb��, N., Tosti, L., Tsujimoto, S., Vagelli, V., van Scherpenberg, J., Vanzo, G., Acosta, M. Vazquez, Vigorito, C. F., Vitale, V., Vovk, I., Will, M., and Zari��, D.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences
Abstract: Aims: $��$ rays can be used as a tracer in the search of sources of Galactic cosmic rays (CRs). We present deep observations of the Galactic Centre (GC) region with the MAGIC telescopes, which we use for inferring the underlying CR distribution. Methods: We observed the GC region for ${\approx}100$ hours with the MAGIC telescopes from 2012 to 2017, at high zenith angles (58-70~deg). This implies a larger energy threshold, but also an increased effective collection area compared to low zenith observations. Using new software, we derive instrument response and background models, enabling us to study the diffuse emission in the region. We use pre-existing data of the gas distribution in the GC region to derive the underlying distribution of CRs. Results: We obtain a significant detection for all four model components used to fit our data (Sgr~A*, ``Arc'', G0.9+0.1, and an extended component for the Galactic Ridge). We find that the diffuse component is best described as a power-law with index 2 and an exponential cut-off at around 20~TeV with the significance of the cut-off being only 2~$��$. The derived cosmic-ray profile hints to a peak at the GC position, with a measured profile index of $1.2 \pm 0.3$, supporting the hypothesis of a CR accelerator at the GC. We argue that the measurements of this profile are presently limited by our knowledge of the gas distribution in the GC vicinity., 10 pages, 10 figures. Accepted for publication by A&A. Corresponding authors: Christian Fruck (fruck@mpp.mpg.de), Ievgen Vovk (vovk@icrr.u-tokyo.ac.jp), Yuki Iwamura (iwamura@icrr.u-tokyo.ac.jp) and Marcel Strzys (strzys@icrr.u-tokyo.ac.jp)
Published: 2020
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9. Multiwavelength variability and correlation studies of Mrk 421 during historically low X-ray and $��$-ray activity in 2015$-$2016

Author: MAGIC Collaboration, Acciari, V. A., Ansoldi, S., Antonelli, L. A., Asano, K., Babi��, A., Banerjee, B., Baquero, A., de Almeida, U. Barres, Barrio, J. A., Gonz��lez, J. Becerra, Bednarek, W., Bellizzi, L., Bernardini, E., Bernardos, M., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Blanch, O., Bonnoli, G., 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 Girolamo, T., Di Pierro, F., Di Venere, L., Espi��eira, E. Do Souto, Prester, D. Dominis, Donini, A., Doro, M., Ramazani, V. Fallah, Fattorini, A., Ferrara, G., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Fukami, S., L��pez, R. J. Garc��a, Garczarczyk, M., 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., 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, M., L��pez-Coto, R., L��pez-Oramas, A., Loporchio, S., Fraga, B. Machado de Oliveira, Maggio, C., Majumdar, P., Makariev, M., Mallamaci, M., Maneva, G., Manganaro, M., Maraschi, L., Mariotti, M., Mart��nez, M., Mazin, D., 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., 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., 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., 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., Torres-Alb��, N., Tosti, L., Truzzi, S., van Scherpenberg, J., Vanzo, G., Acosta, M. Vazquez, Ventura, S., Verguilov, V., Vigorito, C. F., Vitale, V., Vovk, I., Will, M., Zari��, D., collaboration, FACT, 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., Collaborators, MWL, 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., L��hteenm��ki, A., Tornikoski, M., Ramakrishnan, V., J��rvel��, E., Vera, R. J. C., Righini, S., and Lien, A. Y.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics
Abstract: We report a characterization of the multi-band flux variability and correlations of the nearby (z=0.031) blazar Markarian 421 (Mrk 421) using data from Mets��hovi, Swift, Fermi-LAT, MAGIC, FACT and other collaborations and instruments from November 2014 till June 2016. Mrk 421 did not show any prominent flaring activity, but exhibited periods of historically low activity above 1 TeV (F$_{>1\mathrm{TeV}}$0.1 TeV) $��$-rays, which, despite the low activity, show a significant positive correlation with no time lag. The HR$_\mathrm{keV}$ and HR$_\mathrm{TeV}$ 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 days centered at time lag zero, and a positive correlation between the optical/GeV and the radio emission over a range of about 60 days centered at a time lag of $43^{+9}_{-6}$ days.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., 45 pages, 30 figures, 6 tables, accepted for publication in MNRAS
Published: 2020
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10. A Fast Very High Energy $��$-ray Flare from BL Lacertae during a Period of Multiwavelength activity in June 2015

Author: MAGIC Collaboration, Acciari, V. A., Ansoldi, S., Antonelli, L. A., Engels, A. Arbet, Baack, D., Babi��, A., Banerjee, B., Bangale, P., de Almeida, U. Barres, Barrio, J. A., Gonz��lez, J. Becerra, 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., Espi��era, E. Do Souto, Dom��nguez, A., Prester, D. Dominis, Dorner, D., Doro, M., Einecke, S., Elsaesser, D., Ramazani, V. Fallah, Fattorini, A., Fern��ndez-Barral, A., Ferrara, G., Fidalgo, D., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., Gallozzi, S., L��pez, R. J. Garc��a, Garczarczyk, M., Gaug, M., Giammaria, P., Godinovi��, 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., Kuve��di��, D., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., L��pez, M., L��pez-Oramas, A., Maggio, C., Majumdar, P., Makariev, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Mart��nez, 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., Nogu��s, L., N��the, M., Paiano, S., Palacio, J., Paneque, D., Paoletti, R., Paredes, J. M., Pedaletti, G., Pe��il, P., Peresano, M., Persic, M., Moroni, P. G. Prada, Prandini, E., Puljak, I., Garcia, J. R., Rhode, W., Rib��, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Saito, T., Satalecka, K., Schweizer, T., Sitarek, J., ��nidari��, I., Sobczynska, D., Somero, A., Stamerra, A., Strzys, M., Suri��, T., Tavecchio, F., Temnikov, P., Terzi��, T., Teshima, M., Torres-Alb��, N., Tsujimoto, S., van Scherpenberg, J., Vanzo, G., Acosta, M. Vazquez, Vovk, I., Will, M., Zari��, 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., L��hteenm��ki, A., Tornikoski, M., and Agudo, I.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics
Abstract: The mechanisms producing fast variability of the $��$-ray emission in active galactic nuclei are under debate. The MAGIC telescopes detected a fast very high energy (VHE, E$>100$ GeV) $��$-ray flare from BL Lacertae on 2015 June 15. The flare had a maximum flux of $(1.5\pm 0.3)\times 10^{-10}$ photons cm$^{-2}$ s$^{-1}$ and halving time of $26\pm8$ minutes. The MAGIC observations were triggered by a high state in the optical and high energy (HE, E$>100$ MeV) $��$-ray bands. In this paper we present the MAGIC VHE $��$-ray data together with multiwavelength data from radio, optical, X-rays, and HE $��$ rays from 2015 May 1 to July 31. Well-sampled multiwavelength data allow us to study the variability in detail and compare it to the other epochs when fast VHE $��$-ray flares have been detected from this source. Interestingly, we find that the behaviour in radio, optical, X-rays and HE $��$-rays is very similar to two other observed VHE $��$-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 $��$-ray data with the star-jet interaction model. We find that all of the tested emission models are compatible with the fast VHE $��$-ray flare, but all have some tension with the multiwavelength observations., Accepted to Astronomy & Astrophysics
Published: 2019
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11. Discovery of TeV $��$-ray emission from the neighbourhood of the supernova remnant G24.7+0.6 by MAGIC

Author: MAGIC Collaboration, Acciari, V. A., Ansoldi, S., Antonelli, L. A., Engels, A. Arbet, Arcaro, C., Baack, D., Babi��, A., Banerjee, B., Bangale, P., de Almeida, U. Barres, Barrio, J. A., Gonz��lez, J. Becerra, 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., Dom��nguez, A., Prester, D. Dominis, Dorner, D., Doro, M., Einecke, S., Elsaesser, D., Ramazani, V. Fallah, Fattorini, A., Fern��ndez-Barral, A., Ferrara, G., Fidalgo, D., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., Gallozzi, S., L��pez, R. J. Garc��a, Garczarczyk, M., Gaug, M., Giammaria, P., Godinovi��, 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., Kuve��di��, D., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., L��pez, M., L��pez-Oramas, A., Maggio, C., Majumdar, P., Makariev, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Mart��nez, M., Masuda, S., Mazin, D., Minev, M., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Moreno, V., Moretti, E., Neustroev, V., Niedzwiecki, A., Rosillo, M. Nievas, Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogu��s, L., Paiano, S., Palacio, J., Paneque, D., Paoletti, R., Paredes, J. M., Pedaletti, G., Pe��il, P., Peresano, M., Persic, M., Moroni, P. G. Prada, Prandini, E., Puljak, I., Garcia, J. R., Rhode, W., Rib��, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Saito, T., Satalecka, K., Schweizer, T., Sitarek, J., ��nidari��, I., Sobczynska, D., Somero, A., Stamerra, A., Strzys, M., Suri��, T., Tavecchio, F., Temnikov, P., Terzi��, T., Teshima, M., Torres-Alb��, N., Tsujimoto, S., Vanzo, G., Acosta, M. Vazquez, Vovk, I., Ward, J. E., Will, M., Zari��, D., Wilhelmi, E. de O��a, Torres, D. F., and Zanin, R.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: SNR G24.7+0.6 is a 9.5 kyrs radio and $��$-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 ($��$$\sim$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\ with the MAGIC telescopes for a total of 31 hours. We detect very high energy $��$-ray emission from an extended source located 0.34\degr\ away from the center of the radio SNR. The new source, named \mgc\ is detected up to 5\,TeV, and its spectrum is well-represented by a power-law function with spectral index of $2.74 \pm 0.08$. 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 1.5$��$ point to a common origin. We analysed 8 years 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 cutoff at $1.9\pm0.5$\,TeV. The detected $��$-ray emission can be interpreted as the results of proton-proton interaction between the supernova and the CO-rich surrounding., accepted for publication by MNRAS
Published: 2018
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12. Periastron Observations of TeV Gamma-Ray Emission from a Binary System with a 50-year Period

Author: The VERITAS Collaboration, 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, E., Quinn, J., Ragan, K., Richards, G. T., Roache, E., Sadeh, I., Santander, M., Schlenstedt, S., Sembroski, G. H., Sushch, I., Tyler, J., Vassiliev, V. V., Wakely, S. P., Weinstein, A., Wells, R. M., Wilcox, P., Wilhelm, A., Williams, D. A., Williamson, T. J, Zitzer, B., Collaboration, MAGIC, Acciari, V. A., Ansoldi, S., Antonelli, L. A., Engels, A. Arbet, Baack, D., Babi��, A., Banerjee, B., de Almeida, U. Barres, Barrio, J. A., Gonz��lez, J. Becerra, 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., Espi��era, E. Do Souto, Dom��nguez, A., Prester, D. Dominis, Dorner, D., Doro, M., Einecke, S., Elsaesser, D., Ramazani, V. Fallah, Fattorini, A., Fern��ndez-Barral, A., Ferrara, G., Fidalgo, D., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., Gallozzi, S., L��pez, R. J. Garc��a, Garczarczyk, M., Gasparyan, S., Gaug, M., Giammaria, P., Godinovi��, N., Guberman, D., Hadasch, D., Hahn, A., Herrera, J., Hoang, J., Hrupec, D., Inoue, S., Ishio, K., Iwamura, Y., Kubo, H., Kushida, J., Kuve��di��, D., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., L��pez, M., L��pez-Oramas, A., 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., 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., Nogu��s, L., N��the, M., Paiano, S., Palacio, J., Paneque, D., Paoletti, R., Paredes, J. M., Pedaletti, G., Pe��il, P., Peresano, M., Persic, M., Moroni, P. G. Prada, Prandini, E., Puljak, I., Garcia, J. R., Rhode, W., Rib��, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Sahakyan, N., Saito, T., Satalecka, K., Schweizer, T., Sitarek, J., ��nidari��, I., Sobczynska, D., Somero, A., Stamerra, A., Strzys, M., Suri��, T., Tavecchio, F., Temnikov, P., Terzi��, T., Teshima, M., Torres-Alb��, N., Tsujimoto, S., van Scherpenberg, J., Vanzo, G., Acosta, M. Vazquez, Vovk, I., Will, M., Zari��, D., 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, E., Quinn, J., Ragan, K., Richards, G. T., Roache, E., Sadeh, I., Santander, M., Schlenstedt, S., Sembroski, G. H., Sushch, I., Tyler, J., Vassiliev, V. V., Wakely, S. P., Weinstein, A., Wells, R. M., Wilcox, P., Wilhelm, A., 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. Barre, Barrio, J. A., González, J. Becerra, 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., Vela, P. Da, Dazzi, F., Angelis, A. De, Lotto, B. De, Delfino, M., Delgado, J., Pierro, F. Di, Souto Espinera, E. Do, Dominguez, A., Prester, D. Domini, 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. Garcia, 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., Martinez, 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. Nieva, 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., Penil, 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-Alba, N., Tsujimoto, S., Scherpenberg, J. Van, Vanzo, G., Acosta, M. Vazquez, Vovk, I., Will, M., Zarić, D., and Universitat de Barcelona
Subjects: gamma rays: general, pulsars: individual (PSR J2032+4127, VER J2032+414, MAGIC J2032 +4127), stars: individual (MT91 213), X-rays: binaries, Astronomy and Astrophysics, Space and Planetary Science, MAGIC J2032 +4127), Astrophysics, 01 natural sciences, law.invention, Raigs gamma, Observatory, law, Astrophysics::Solar and Stellar Astrophysics, MAGIC (telescope), 010303 astronomy & astrophysics, astro-ph.HE, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), education.field_of_study, binarie [X-rays], Púlsars, Física nuclear, Astrophysics - High Energy Astrophysical Phenomena, individual (MT91 213) [stars], Astrophysics and Astronomy, Be star, Astrophysics::High Energy Astrophysical Phenomena, Population, FOS: Physical sciences, Compact star, Telescope, Pulsar, 0103 physical sciences, pulsars: individual (PSR J2032+4127, individual (PSR J2032+4127, VER J2032+414, MAGIC J2032 +4127) [pulsars], 010306 general physics, education, MAGIC J2032+4127), Pulsars, pulsars: individual (PSR J2032+4127, VER J2032+414, MAGIC J2032+4127), Gamma rays, Institut für Physik und Astronomie, Astronomy and Astrophysic, Light curve, Stars, Estels, VER J2032+414, 13. Climate action, ddc:520, general [gamma rays]
Abstract: We report on observations of the pulsar / Be star binary system PSR J2032+4127 / MT91 213 in the energy range between 100 GeV and 20 TeV with the VERITAS and MAGIC imaging atmospheric 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 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 (XRT) on board the Neil Gehrels \textit{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 we have observed, and we discuss the relationship between the binary system and the overlapping steady extended source, TeV J2032+4130., Comment: 12 pages, 3 figures, 1 table. Accepted for publication in ApJL
Published: 2018
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13. MAGIC observations of MWC 656, the only known Be/BH system

Author: Aleksi��, J., Ansoldi, S., Antonelli, L. A., Antoranz, P., Babic, A., Bangale, P., Barrio, J. A., Gonz��lez, J. Becerra, Bednarek, W., Bernardini, E., Biasuzzi, B., Bil, 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., Wilhelmi, E. de O��a, Mendez, C. Delgado, Prester, D. Dominis, Dorner, D., Doro, M., Einecke, S., Eisenacher, D., Elsaesser, D., Fidalgo, D., Fonseca, M. V., Font, L., Frantzen, K., Fruck, C., Galindo, D., L��pez, R. J. Garc��a, Garczarczyk, M., Terrats, D. Garrido, Gaug, M., Godinovi��, N., Mu��oz, A. Gonz��lez, Gozzini, S. R., Hadasch, D., Hanabata, Y., Hayashida, M., Herrera, J., Hildebr, D., 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., L��pez, M., L��pez-Coto, R., L��pez-Oramas, A., Lorenz, E., Lozano, I., Makariev, M., Mallot, K., Maneva, G., Mankuzhiyil, N., Mannheim, K., Maraschi, L., Marcote, B., Mariotti, M., Mart��nez, M., Mazin, D., Menzel, U., Mir, J. M., A, Mirzoyan, R., Moralejo, A., Munar-Adrover, P., Nakajima, D., Neustroev, V., Niedzwiecki, A., 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., Moroni, P. G. Prada, Pr, E., Ini, Puljak, I., Reinthal, R., Rhode, W., Rib��, M., Rico, J., Garcia, J. Rodriguez, R��gamer, S., Saito, T., Saito, K., Satalecka, K., Scalzotto, V., Scapin, V., Schultz, C., Schweizer, T., Sillanp��, A., Sitarek, J., Snidaric, I., Sobczynska, D., Spanier, F., Stamerra, A., Steinbring, T., Storz, J., Strzys, M., 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., Vogler, P., Will, M., Zanin, R., Casares, J., Mold��n, J., Aleksić, J., Ansoldi, Stefano, Antonelli, L. A., Antoranz, P., Babic, A., Bangale, P., 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., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Eisenacher, D., Elsaesser, D., 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., Hildebrand, D., 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, Francesco, 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., Mazin, D., Menzel, U., Miranda, J. M., Mirzoyan, R., Moralejo, A., Munar Adrover, P., Nakajima, D., Neustroev, V., Niedzwiecki, A., 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., Rügamer, S., Saito, T., Saito, K., Satalecka, K., Scalzotto, V., Scapin, V., Schultz, C., Schweizer, T., Sillanpää, A., Sitarek, J., Snidaric, I., Sobczynska, D., Spanier, F., Stamerra, A., Steinbring, T., Storz, J., Strzys, M., Takalo, L., Takami, H., Tavecchio, F., Temnikov, P., Terzić, T., Tescaro, D., Teshima, M., Thaele, J., Tibolla, O., Torres, D. F., Toyama, T., Treves, A., Vogler, P., Will, M., Zanin, R., Casares, J., and Moldón, J.
Subjects: Astrofísica, Be star, Stars: individual: MWC 656, Astrophysics::High Energy Astrophysical Phenomena, Flux, FOS: Physical sciences, Context (language use), astro-ph.HE, Astrophysics, general, gamma rays: stars, X-rays: binaries, stars: individual: MWC 656 [astroparticle physics, binaries], astroparticle physics, binaries: general, gamma rays: stars, X-rays: binaries, stars: individual: MWC 656, Gamma rays: stars, Astroparticle physics, Binaries: general, X-rays: binaries, Astronomy and Astrophysics, Space and Planetary Science, binaries: general, gamma rays: observations, gamma rays: binary, stars: individual (MWC 656), X-rays: individual (MWC 656), Gamma ray astronomy, Astrophysics::Solar and Stellar Astrophysics, Astronomia de raigs gamma, MAGIC (telescope), Estels binaris de raigs X, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Gamma ray, Black hole, X-ray binaries, Crab Nebula, ddc:520, Satellite, Electrónica, Física nuclear, Electricidad, Astrophysics - High Energy Astrophysical Phenomena
Abstract: Context: MWC 656 has recently been established as the first observationally detected high-mass X-ray binary system containing a Be star and a black hole (BH). The system has been associated with a gamma-ray flaring event detected by the AGILE satellite in July 2010. Aims: Our aim is to evaluate if the MWC 656 gamma-ray emission extends to very high energy (VHE > 100 GeV) gamma rays. Methods. We have observed MWC 656 with the MAGIC telescopes for $\sim$23 hours during two observation periods: between May and June 2012 and June 2013. During the last period, observations were performed contemporaneously with X-ray (XMM-Newton) and optical (STELLA) instruments. Results: We have not detected the MWC 656 binary system at TeV energies with the MAGIC Telescopes in either of the two campaigns carried out. Upper limits (ULs) to the integral flux above 300 GeV have been set, as well as differential ULs at a level of $\sim$5% of the Crab Nebula flux. The results obtained from the MAGIC observations do not support persistent emission of very high energy gamma rays from this system at a level of 2.4% the Crab flux., Accepted for publication in A&A. 5 pages, 2 figures, 2 tables
Published: 2015

14. Very-high-energy ��-ray observations of novae and dwarf novae with the MAGIC telescopes

Author: 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., Gonz��lez, 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��a, Mendez, C. Delgado, Di Pierro, F., Prester, D. Dominis, Dorner, D., Doro, M., Einecke, S., Glawion, D. Eisenacher, Elsaesser, D., Fern��ndez-Barral, A., Fidalgo, D., Fonseca, M. V., Font, L., Frantzen, K., Fruck, C., Galindo, D., L��pez, R. J. Garc��a, Garczarczyk, M., Terrats, D. Garrido, Gaug, M., Giammaria, P., Godinovi��, N., Mu��oz, A. Gonz��lez, 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., L��pez, M., L��pez-Coto, R., L��pez-Oramas, A., Lorenz, E., Majumdar, P., Makariev, M., Mallot, K., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Marcote, B., Mariotti, M., Mart��nez, 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., Rib��, M., Rico, J., Garcia, J. Rodriguez, Saito, T., Saito, K., Satalecka, K., Scapin, V., Schultz, C., Schweizer, T., Sillanp��, A., Sitarek, J., Snidaric, I., Sobczynska, D., Stamerra, A., Steinbring, T., Strzys, M., Takalo, L., Takami, H., Tavecchio, F., Temnikov, P., Terzi��, T., Tescaro, D., Teshima, M., Thaele, J., Torres, D. F., Toyama, T., Treves, A., Verguilov, V., Vovk, I., Will, M., Zanin, R., Desiante, R., and Hays, E.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Solar and Stellar Astrophysics, FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment
Abstract: Context. In the last five years the Fermi Large Area Telescope (LAT) instrument detected GeV ��-ray emission from five novae. The GeV emission can be interpreted in terms of an inverse Compton process of electrons accelerated in a shock. In this case it is expected that protons in the same conditions can be accelerated to much higher energies. Consequently they may produce a second component in the ��-ray spectrum at TeV energies. Aims. We aim to explore the very-high-energy domain to search for ��-ray emission above 50 GeV and to shed light on the acceleration process of leptons and hadrons in nova explosions. Methods. We have performed observations with the MAGIC telescopes of the classical nova V339 Del shortly after the 2013 outburst, triggered by optical and subsequent GeV ��-ray detec- tions. We also briefly report on VHE observations of the symbiotic nova YY Her and the dwarf nova ASASSN-13ax. We complement the TeV MAGIC observations with the analysis of con- temporaneous Fermi-LAT data of the sources. The TeV and GeV observations are compared in order to evaluate the acceleration parameters for leptons and hadrons. Results. No significant TeV emission was found from the studied sources. We computed upper limits on the spectrum and night-by-night flux. The combined GeV and TeV observations of V339 Del limit the ratio of proton to electron luminosities to Lp, 7 pages, 2 figures, accepted for publication in A&A
Published: 2015
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15. MAGIC search for VHE $��$-ray emission from AE Aquarii in a multiwavelength context

Author: Aleksi��, J., Ansoldi, S., Antonelli, L. A., Antoranz, P., Babic, A., Bangale, P., Barrio, J. A., Gonz��lez, J. Becerra, 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., Wilhelmi, E. de O��a, Mendez, C. Delgado, Doert, M., Prester, D. Dominis, Dorner, D., Doro, M., Einecke, S., Eisenacher, D., Elsaesser, D., Fonseca, M. V., Font, L., Frantzen, K., Fruck, C., Galindo, D., L��pez, R. J. Garc��a, Garczarczyk, M., Terrats, D. Garrido, Gaug, M., Godinovi��, N., Mu��oz, A. Gonz��lez, Gozzini, S. R., Hadasch, D., Hanabata, Y., Hayashida, M., Herrera, J., Hildebrand, D., Hose, J., Hrupec, D., Idec, W., Kadenius, V., Kellermann, H., Kodani, K., Konno, Y., Krause, J., Kubo, H., Kushida, J., La Barbera, A., Lelas, D., Lewandowska, N., Lindfors, E., Lombardi, S., L��pez, M., L��pez-Coto, R., L��pez-Oramas, A., Lorenz, E., Lozano, I., Makariev, M., Mallot, K., Maneva, G., Mankuzhiyil, N., Mannheim, K., Maraschi, L., Marcote, B., Mariotti, M., Mart��nez, M., Mazin, D., Menzel, U., 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., Persic, M., Moroni, P. G. Prada, Prandini, E., Preziuso, S., Puljak, I., Reinthal, R., Rhode, W., Rib��, M., Rico, J., Garcia, J. Rodriguez, R��gamer, S., Saggion, A., Saito, T., Saito, K., Satalecka, K., Scalzotto, V., Scapin, V., Schultz, C., Schweizer, T., Sillanp��, A., Sitarek, J., Snidaric, I., Sobczynska, D., Spanier, F., Stamatescu, V., Stamerra, A., Steinbring, T., Storz, J., Strzys, M., 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., Zanin, R., Bogosavljevic, M., Ioannou, Z., Mauche, C. W., Palaiologou, E. V., P��rez-Torres, M. A., and Tuominen, T.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics::Galaxy Astrophysics
Abstract: It has been claimed that the nova-like cataclysmic variable (CV) AE Aquarii (AE Aqr) is a very-high-energy (VHE, $E>$100 GeV) source both on observational and theoretical grounds. We aim to search for VHE gamma-ray emission from AE Aqr during different states of the source at several wavelengths to confirm or rule out previous claims of detection of gamma-ray emission from this object. We report on observations of AE Aqr performed by MAGIC. The source was observed during 12 hours as part of a multiwavelength campaign carried out between May and June 2012 covering the optical, X-ray, and gamma-ray ranges. Besides MAGIC, the other facilities involved were the KVA, Skinakas, and Vidojevica telescopes in the optical and Swift in X-rays. We calculated integral upper limits coincident with different states of the source in the optical. We computed upper limits to the pulsed emission limiting the signal region to 30% of the phaseogram and we also searched for pulsed emission at different frequencies applying the Rayleigh test. AE Aqr was not detected at VHE energies during the multiwavelength campaign. We establish integral upper limits at the 95\% confidence level for the steady emission assuming the differential flux proportional to a power-law function d��/dE \propto E^{-Gamma}, with a Crab-like photon spectral index of Gamma=2.6. The upper limit above 200 GeV is 6.4\times10^{-12} cm^{-2}s^{-1} and above 1 TeV is 7.4\times10^{-13} cm^{-2}s^{-1}. We obtained an upper limit for the pulsed emission of 2.6\times10^{-12} cm^{-2}s^{-1} for energies above 200 GeV. Applying the Rayleigh test for pulsed emission at different frequencies we did not find any significant signal. Our results indicate that AE Aqr is not a VHE gamma-ray emitter at the level of emission previously claimed. We have established the most constraining upper limits for the VHE gamma-ray emission of AE Aqr., 9 pages, 5 figures. Accepted for publication in A&A
Published: 2014
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16. Discovery of VHE gamma-ray emission from the BL Lac object B3 2247+381 with the MAGIC telescopes

Author: The MAGIC Collaboration, Aleksi��, J., Alvarez, E. A., Antonelli, L. A., Antoranz, P., Asensio, M., Backes, M., Barrio, J. A., Bastieri, D., Gonz��lez, J. Becerra, Bednarek, W., Berdyugin, A., Berger, K., Bernardini, E., Biland, A., Blanch, O., Bock, R. K., Boller, A., Bonnoli, G., Tridon, D. Borla, Braun, I., Bretz, T., Ca��ellas, A., Carmona, E., Carosi, A., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Cossio, L., Covino, S., Dazzi, F., De Angelis, A., De Caneva, G., del Pozo, E. De Cea, De Lotto, B., Mendez, C. Delgado, Ortega, A. Diago, Doert, M., Dom��nguez, A., Prester, D. Dominis, Dorner, D., Doro, M., Elsaesser, D., Ferenc, D., Fonseca, M. V., Font, L., Fruck, C., L��pez, R. J. Garc��a, Garczarczyk, M., Garrido, D., Giavitto, G., Godinovi��, N., Hadasch, D., H��fner, D., Herrero, A., Hildebrand, D., H��hne-M��nch, D., Hose, J., Hrupec, D., Huber, B., Jogler, T., Kellermann, H., Klepser, S., Kr��henb��hl, T., Krause, J., La Barbera, A., Lelas, D., Leonardo, E., Lindfors, E., Lombardi, S., L��pez, M., L��pez-Oramas, A., Lorenz, E., Makariev, M., Maneva, G., Mankuzhiyil, N., Mannheim, K., Maraschi, L., Mariotti, M., Mart��nez, M., Mazin, D., Meucci, M., Miranda, J. M., Mirzoyan, R., Miyamoto, H., Mold��n, J., Moralejo, A., Munar-Adrover, P., Nieto, D., Nilsson, K., Orito, R., Oya, I., Paneque, D., Paoletti, R., Pardo, S., Paredes, J. M., Partini, S., Pasanen, M., Pauss, F., Perez-Torres, M. A., Persic, M., Peruzzo, L., Pilia, M., Pochon, J., Prada, F., Moroni, P. G. Prada, Prandini, E., Puljak, I., Reichardt, I., Reinthal, R., Rhode, W., Rib��, M., Rico, J., R��gamer, S., Saggion, A., Saito, K., Saito, T. Y., Salvati, M., Satalecka, K., Scalzotto, V., Scapin, V., Schultz, C., Schweizer, T., Shayduk, M., Shore, S. N., Sillanp��, A., Sitarek, J., Snidaric, I., Sobczynska, D., Spanier, F., Spiro, S., Stamatescu, V., Stamerra, A., Steinke, B., Storz, J., Strah, N., Suri��, T., Takalo, L., Takami, H., Tavecchio, F., Temnikov, P., Terzi��, T., Tescaro, D., Teshima, M., Tibolla, O., Torres, D. F., Treves, A., Uellenbeck, M., Vankov, H., Vogler, P., Wagner, R. M., Weitzel, Q., Zabalza, V., Zandanel, F., Zanin, R., Kadenius, V., Weidinger, M., and Buson, S.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), astro-ph.HE, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Astrophysics::High Energy Astrophysical Phenomena, astro-ph.CO, FOS: Physical sciences, ddc:520, Electrónica, Electricidad, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: We study the non-thermal jet emission of the BL Lac object B3 2247+381 during a high optical state. The MAGIC telescopes observed the source during 13 nights between September 30th and October 30th 2010, collecting a total of 14.2 hours of good quality very high energy (VHE) $\gamma$-ray data. Simultaneous multiwavelength data was obtained with X-ray observations by the Swift satellite and optical R-band observations at the KVA-telescope. We also use high energy $\gamma$-ray (HE, 0.1 GeV-100 GeV) data from the Fermi satellite. The BL Lac object B3 2247+381 (z=0.119) was detected, for the first time, at VHE $\gamma$-rays at a statistical significance of 5.6 $\sigma$. A soft VHE spectrum with a photon index of -3.2 $\pm$ 0.6 was determined. No significant short term flux variations were found. We model the spectral energy distribution using a one-zone SSC-model, which can successfully describe our data., Comment: 7 pages, 6 figures, 1 table, accepted for publication in Astronomy and Astrophysics
Published: 2012

17. Detection of VHE ��-rays from HESS J0632+057 during the 2011 February X-ray outburst with the MAGIC Telescopes

Author: The MAGIC Collaboration, Aleksi��, J., Alvarez, E. A., Antonelli, L. A., Antoranz, P., Asensio, M., Backes, M., de Almeida, U. Barres, Barrio, J. A., Bastieri, D., Gonz��lez, J. Becerra, Bednarek, W., Berger, K., Bernardini, E., Biland, A., Blanch, O., Bock, R. K., Boller, A., Bonnoli, G., Tridon, D. Borla, Bosch-Ramon, V., Bretz, T., Ca��ellas, A., Carmona, E., Carosi, A., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Cossio, L., Covino, S., Da Vela, P., Dazzi, F., De Angelis, A., De Caneva, G., del Pozo, E. De Cea, De Lotto, B., Mendez, C. Delgado, Ortega, A. Diago, Doert, M., Dom��nguez, A., Prester, D. Dominis, Dorner, D., Doro, M., Eisenacher, D., Elsaesser, D., Ferenc, D., Fonseca, M. V., Font, L., Fruck, C., L��pez, R. J. Garc��a, Garczarczyk, M., Terrats, D. Garrido, Giavitto, G., Godinovi��, N., Mu��oz, A. Gonz��lez, Gozzini, S. R., Hadasch, D., H��fner, D., Herrero, A., Hildebrand, D., Hose, J., Hrupec, D., Huber, B., Jankowski, F., Jogler, T., Kadenius, V., Kellermann, H., Klepser, S., Kr��henb��hl, T., Krause, J., La Barbera, A., Lelas, D., Leonardo, E., Lewandowska, N., Lindfors, E., Lombardi, S., L��pez, M., L��pez-Coto, R., L��pez-Oramas, A., Lorenz, E., Makariev, M., Maneva, G., Mankuzhiyil, N., Mannheim, K., Maraschi, L., Mariotti, M., Mart��nez, M., Mazin, D., Meucci, M., Miranda, J. M., Mirzoyan, R., Mold��n, J., Moralejo, A., Munar-Adrover, P., Niedzwiecki, A., Nieto, D., Nilsson, K., Nowak, N., Orito, R., Paiano, S., Paneque, D., Paoletti, R., Pardo, S., Paredes, J. M., Partini, S., Perez-Torres, M. A., Persic, M., Pilia, M., Pochon, J., Prada, F., Moroni, P. G. Prada, Prandini, E., Gimenez, I. Puerto, Puljak, I., Reichardt, I., Reinthal, R., Rhode, W., Rib��, M., Rico, J., R��gamer, S., Saggion, A., Saito, K., Saito, T. Y., Salvati, M., Satalecka, K., Scalzotto, V., Scapin, V., Schultz, C., Schweizer, T., Shore, S. N., Sillanp��, A., Sitarek, J., Snidaric, I., Sobczynska, D., Spanier, F., Spiro, S., Stamatescu, V., Stamerra, A., Steinke, B., Storz, J., Strah, N., Sun, S., Suri��, T., Takalo, L., Takami, H., Tavecchio, F., Temnikov, P., Terzi��, T., Tescaro, D., Teshima, M., Tibolla, O., Torres, D. F., Treves, A., Uellenbeck, M., Vogler, P., Wagner, R. M., Weitzel, Q., Zabalza, V., Zandanel, F., and Zanin, R.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences
Abstract: The very high energy (VHE) ��-ray source HESS J0632+057 has recently been confirmed to be a ��-ray binary. The optical counterpart is the Be star MWC 148, and a compact object of unknown nature orbits it every ~321 d with a high eccentricity of ~0.8. We monitored HESS J0632+057 with the stereoscopic MAGIC telescopes from 2010 October to 2011 March and detected significant VHE ��-ray emission during 2011 February, when the system exhibited an X-ray outburst. We find no ��-ray signal in the other observation periods when the system did not show increased X-ray flux. Thus HESS J0632+057 exhibits ��-ray variability on timescales of the order of one to two months possibly linked to the X-ray outburst that takes place about 100 days after the periastron passage. Furthermore our measurements provide for the first time the ��-ray spectrum down to about 140 GeV and indicate no turnover of the spectrum at low energies. We compare the properties of HESS J0632+057 with the similar ��-ray binary LS I +61 303, and discuss on the possible origin of the multi-wavelength emission of the source, 6 pages and 3 figures, submitted, corresponding authors T. Jogler and P. Munar-Adrover
Published: 2012
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18. MAGIC low energy observation of GRB090102 afterglow

Author: Carosi, A., Antonelli, L. A., de Almeida, U. Barres, Bastieri, D., Gonz��lez, J. Becerra, Colombo, E., Garczarczyk, M., Covino, S., La Barbera, A, Spiro, S., Dom��nguez, A., Gaug, M., Longo, F., and Scapin, V.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics - High Energy Astrophysical Phenomena
Abstract: Hints for a GeV component in the emission from GRBs are known since the EGRET observations during the '90s and they have been recently confirmed by the data of the Fermi satellite. These results have, however, shown that a fully satisfactory interpretative framework of the GRB phenomena is still lacking. The MAGIC telescope opens the possibility to extend the measurement of GRBs in the several tens up to hundreds of GeV energy range. From the theoretical point of view, both leptonic and hadronic processes have been suggested to explain the possible GeV/TeV counterpart of GRBs. Observations with ground-based telescopes of very high energy photons (E>30 GeV) from these sources are going to play a key role in discriminating among the different proposed emission mechanisms which are barely distinguishable at lower energies. MAGIC telescope observations of the GRB090102 (z=1.547) field from 03:14:52 UT to 06:54:01 UT are analyzed to derive upper limits to the GeV/TeV emission. We compare these results to the expected emissions evaluated for different processes in the framework of the standard fireball model. The results we obtained are compatible with the expected emission but cannot yet set further constraints on the theoretical scenario. However, the difficulty in modeling the low energy data for this event makes it difficult to fix in an unambiguous way the physical parameters which describe the fireball. Nonetheless, the MAGIC telescope, thanks to its low energy threshold and fast repositioning, is opening for the first time the possibility to fill the energy gap between space-based gamma detectors and the ground-based measurements. This will makes possible GRBs multiwavelength studies in the very high energy domain., 2011 Fermi Symposium proceedings - eConf C110509
Published: 2011

19. OBSERVATIONS OF THE CRAB PULSAR BETWEEN 25 AND 100 GeV WITH THE MAGIC I TELESCOPE

Author: MAGIC Collaboration, Aleksi��, J., Alvarez, E. A., Antonelli, L. A., Antoranz, P., Asensio, M., Backes, M., Barrio, J. A., Bastieri, D., Gonz��lez, J. Becerra, Bednarek, W., Berdyugin, A., Berger, K., Bernardini, E., Biland, A., Blanch, O., Bock, R. K., Boller, A., Bonnoli, G., Tridon, D. Borla, Braun, I., Bretz, T., Ca��ellas, A., Carmona, E., Carosi, A., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Cossio, L., Covino, S., Dazzi, F., De Angelis, A., De Caneva, G., del Pozo, E. De Cea, De Lotto, B., Mendez, C. Delgado, Ortega, A. Diago, Doert, M., Dom��nguez, A., Prester, D. Dominis, Dorner, D., Doro, M., Eisenacher, D., Elsaesser, D., Ferenc, D., Fonseca, M. V., Font, L., Fruck, C., L��pez, R. J. Garc��a, Garczarczyk, M., Garrido, D., Giavitto, G., Godinovi��, N., Hadasch, D., H��fner, D., Herrero, A., Hildebrand, D., H��hne-M��nch, D., Hose, J., Hrupec, D., Jogler, T., Kellermann, H., Klepser, S., Kr��henb��hl, T., Krause, J., Kushida, J., La Barbera, A., Lelas, D., Leonardo, E., Lindfors, E., Lombardi, S., L��pez, M., L��pez-Oramas, A., Lorenz, E., Makariev, M., Maneva, G., Mankuzhiyil, N., Mannheim, K., Maraschi, L., Marcote, B., Mariotti, M., Mart��nez, M., Mazin, D., Meucci, M., Miranda, J. M., Mirzoyan, R., Mold��n, J., Moralejo, A., Munar-Adrover, P., Nieto, D., Nilsson, K., Orito, R., Otte, N., Oya, I., Paneque, D., Paoletti, R., Pardo, S., Paredes, J. M., Partini, S., Perez-Torres, M. A., Persic, M., Peruzzo, L., Pilia, M., Pochon, J., Prada, F., Moroni, P. G. Prada, Prandini, E., Gimenez, I. Puerto, Puljak, I., Reichardt, I., Reinthal, R., Rhode, W., Rib��, M., Rico, J., Rissi, M., R��gamer, S., Saggion, A., Saito, K., Saito, T. Y., Salvati, M., Satalecka, K., Scalzotto, V., Scapin, V., Schultz, C., Schweizer, T., Shayduk, M., Shore, S. N., Sillanp��, A., Sitarek, J., Snidaric, I., Sobczynska, D., Spanier, F., Spiro, S., Stamatescu, V., Stamerra, A., Steinke, B., Storz, J., Strah, N., Suri��, T., Takalo, L., Takami, H., Tavecchio, F., Temnikov, P., Terzi��, T., Tescaro, D., Teshima, M., Tibolla, O., Torres, D. F., Treves, A., Uellenbeck, M., Vankov, H., Vogler, P., Wagner, R. M., Weitzel, Q., Zabalza, V., Zandanel, F., Zanin, R., Hirotani, K., and Universitat de Barcelona
Subjects: GAMMA-RAY PULSARS, PARTICLE-ACCELERATION, POLAR CAPS, FOS: Physical sciences, FERMI-LAT OBSERVATIONS, Astrophysics, 01 natural sciences, Power law, law.invention, Telescope, RAPIDLY SPINNING PULSARS, SLOT GAPS, Raigs gamma, Pulsar, law, 0103 physical sciences, OUTER GAP ACCELERATOR, MAGIC (telescope), HIGH-ENERGY EMISSION, ELECTRIC-FIELD STRUCTURE, POTENTIAL DROPS, 010306 general physics, 010303 astronomy & astrophysics, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Crab Pulsar, Gamma rays, Order (ring theory), Astronomy and Astrophysics, Gamma rays: stars, pulsars: individual (Crab pulsar, PSR B0531+21), Stars, Estels, Space and Planetary Science, Astrophysics - High Energy Astrophysical Phenomena, Energy (signal processing), Fermi Gamma-ray Space Telescope
Abstract: We report on the observation of $\gamma$-rays above 25\,GeV from the Crab pulsar (PSR B0532+21) using the MAGIC I telescope. Two data sets from observations during the winter period 2007/2008 and 2008/2009 are used. In order to discuss the spectral shape from 100\,MeV to 100\,GeV, one year of public {\it Fermi} Large Area Telescope ({\it Fermi}-LAT) data are also analyzed to complement the MAGIC data. The extrapolation of the exponential cutoff spectrum determined with the Fermi-LAT data is inconsistent with MAGIC measurements, which requires a modification of the standard pulsar emission models. In the energy region between 25 and 100\,GeV, the emission in the P1 phase (from -0.06 to 0.04, location of the main pulse) and the P2 phase (from 0.32 to 0.43, location of the interpulse) can be described by power laws with spectral indices of $-3.1 \pm 1.0_{stat} \pm 0.3_{syst}$ and $-3.5 \pm 0.5_{stat} \pm 0.3_{syst}$, respectively. Assuming an asymmetric Lorentzian for the pulse shape, the peak positions of the main pulse and the interpulse are estimated to be at phases $-0.009 \pm 0.007$ and $0.393 \pm 0.009$, while the full widths at half maximum are $0.025 \pm 0.008$ and $0.053 \pm 0.015$, respectively., Comment: 14 pages, 15 figures, published in Astrophysical Journal
Published: 2011

20. Detection of very-high energy ��-ray emission from NGC 1275 by the MAGIC telescopes

Author: MAGIC Collaboration, Aleksi��, J., Alvarez, E. A., Antonelli, L. A., Antoranz, P., Asensio, M., Backes, M., de Almeida, U. Barres, Barrio, J. A., Bastieri, D., Gonz��lez, J. Becerra, Bednarek, W., Berdyugin, A., Berger, K., Bernardini, E., Biland, A., Blanch, O., Bock, R. K., Boller, A., Bonnoli, G., Tridon, D. Borla, Braun, I., Bretz, T., Ca��ellas, A., Carmona, E., Carosi, A., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Cossio, L., Covino, S., Dazzi, F., De Angelis, A., De Caneva, G., del Pozo, E. De Cea, De Lotto, B., Mendez, C. Delgado, Ortega, A. Diago, Doert, M., Dom��nguez, A., Prester, D. Dominis, Dorner, D., Doro, M., Eisenacher, D., Elsaesser, D., Ferenc, D., Fonseca, M. V., Font, L., Fruck, C., L��pez, R. J. Garc��a, Garczarczyk, M., Garrido, D., Giavitto, G., Godinovi��, N., Gozzini, S. R., Hadasch, D., H��fner, D., Herrero, A., Hildebrand, D., H��hne-M��nch, D., Hose, J., Hrupec, D., Jogler, T., Kellermann, H., Klepser, S., Kr��henb��hl, T., Krause, J., Kushida, J., La Barbera, A., Lelas, D., Leonardo, E., Lewandowska, N., Lindfors, E., Lombardi, S., L��pez, M., L��pez-Coto, R., L��pez-Oramas, A., Lorenz, E., Makariev, M., Maneva, G., Mankuzhiyil, N., Mannheim, K., Maraschi, L., Mariotti, M., Mart��nez, M., Mazin, D., Meucci, M., Miranda, J. M., Mirzoyan, R., Mold��n, J., Moralejo, A., Munar-Adrover, P., Niedzwiecki, A., Nieto, D., Nilsson, K., Nowak, N., Orito, R., Paiano, S., Paneque, D., Paoletti, R., Pardo, S., Paredes, J. M., Partini, S., Perez-Torres, M. A., Persic, M., Peruzzo, L., Pilia, M., Pochon, J., Prada, F., Moroni, P. G. Prada, Prandini, E., Gimenez, I. Puerto, Puljak, I., Reichardt, I., Reinthal, R., Rhode, W., Rib��, M., Rico, J., R��gamer, S., Saggion, A., Saito, K., Saito, T. Y., Salvati, M., Satalecka, K., Scalzotto, V., Scapin, V., Schultz, C., Schweizer, T., Shayduk, M., Shore, S. N., Sillanp��, A., Sitarek, J., Snidaric, I., Sobczynska, D., Spanier, F., Spiro, S., Stamatescu, V., Stamerra, A., Steinke, B., Storz, J., Strah, N., Sun, S., Suri��, T., Takalo, L., Takami, H., Tavecchio, F., Temnikov, P., Terzi��, T., Tescaro, D., Teshima, M., Tibolla, O., Torres, D. F., Treves, A., Uellenbeck, M., Vankov, H., Vogler, P., Wagner, R. M., Weitzel, Q., Zabalza, V., Zandanel, F., Zanin, R., Pfrommer, C., and Pinzke, A.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences
Abstract: We report on the detection of very-high energy (VHE, E>100 GeV) gamma-ray emission from NGC 1275, the central radio galaxy of the Perseus cluster of galaxies. The source has been detected by the MAGIC telescopes with a statistical significance of 6.6 sigma above 100 GeV in 46 hr of stereo observations carried out between August 2010 and February 2011. The measured differential energy spectrum between 70 GeV and 500 GeV can be described by a power law with a steep spectral index of ��=-4.1+/-0.7stat+/-0.3syst, and the average flux above 100 GeV is F_{gamma}=(1.3+/-0.2stat+/-0.3syst) x 10^-11 cm^-2 s^-1. These results, combined with the power-law spectrum measured in the first two years of observations by the Fermi-LAT above 100 MeV, with a spectral index of Gamma ~ -2.1, strongly suggest the presence of a break or cut-off around tens of GeV in the NGC 1275 spectrum. The light curve of the source above 100 GeV does not show hints of variability on a month time scale. Finally, we report on the nondetection in the present data of the radio galaxy IC 310, previously discovered by the Fermi-LAT and MAGIC. The derived flux upper limit F^{U.L.}_{gamma} (>300 GeV)=1.2 x 10^-12 cm^-2 s^-1 is a factor ~ 3 lower than the mean flux measured by MAGIC between October 2009 and February 2010, thus confirming the year time-scale variability of the source at VHE., Corresponding authors are S. Lombardi, P. Colin, D. Hildebrand, and F. Zandanel. Published in A&A; 4 pages, 4 figures
Published: 2011
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21. OBSERVATIONS OF THE CRAB PULSAR BETWEEN 25 AND 100 GeV WITH THE MAGIC I TELESCOPE.

Author: Aleksić, J., Alvarez, E. A., Antonelli, L. A., Antoranz, P., Asensio, M., Backes, M., Barrio, J. A., Bastieri, D., Gonz´lez, J. Becerra, Bednarek, W., Berdyugin, A., Berger, K., Bernardini, E., Biland, A., Blanch, O., Bock, R. K., Boller, A., Bonnoli, G., Tridon, D. Borla, and Braun, I.
Subjects: PULSARS, NEUTRON stars, TELESCOPES, ASTRONOMY, RADIATION sources
Abstract: We report on the observation of γ-rays above 25 GeV from the Crab pulsar (PSR B0532+21) using the MAGIC I telescope. Two data sets from observations during the winter period 2007/2008 and 2008/2009 are used. In order to discuss the spectral shape from 100 MeV to 100 GeV, one year of public Fermi Large Area Telescope (Fermi-LAT) data are also analyzed to complement the MAGIC data. The extrapolation of the exponential cutoff spectrum determined with the Fermi-LAT data is inconsistent with MAGIC measurements, which requires a modification of the standard pulsar emission models. In the energy region between 25 and 100 GeV, the emission in the PI phase (from -0.06 to 0.04, location of the main pulse) and the P2 phase (from 0.32 to 0.43, location of the interpulse) can be described by power laws with spectral indices of -3.1 ± 1.0stat ± 0.3syst and -3.5 ± 0.5stat ± 0.3syst, respectively. Assuming an asymmetric Lorentzian for the pulse shape, the peak positions of the main pulse and the interpulse are estimated to be at phases -0.009 ± 0.007 and 0.393 ± 0.009, while the full widths at half-maximum are 0.025 ± 0.008 and 0.053 ± 0.015, respectively. [ABSTRACT FROM AUTHOR]
Published: 2011
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22. 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

23. 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

24. Optimized dark matter searches in deep observations of Segue 1 with MAGIC.

Author: Aleksić, J., Ansoldi, S., Antonelli, L.A., Antoranz, P., Babic, A., Bangale, P., Almeida, U. Barres de, Barrio, J.A., Gonz�lez, J. Becerra, Bednarek, W., Berger, K., Bernardini, E., Biland, A., Blanch, O., Bock, R.K., Bonnefoy, S., Bonnoli, G., Borracci, F., Bretz, T., and Carmona, E.
Published: 2014
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24 results on '"Gonz��lez, J. Becerra"'

1. Multiwavelength study of the gravitationally lensed blazar QSO B0218+357 between 2016 and 2020

2. A search for optical and near-infrared counterparts of the compact binary merger GW190814

3. The Great Markarian 421 Flare of February 2010: Multiwavelength variability and correlation studies

4. Teraelectronvolt emission from the $��$-ray burst GRB 190114C

5. Observation of inverse Compton emission from a long $��$-ray burst

6. Detection of the Geminga pulsar with MAGIC hints at a power-law tail emission beyond 15 GeV

7. Quasi-periodic behaviour in the optical and ��-ray light curves of blazars 3C 66A and B2 1633+38

8. MAGIC observations of the diffuse $��$-ray emission in the vicinity of the Galactic Centre

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

10. A Fast Very High Energy $��$-ray Flare from BL Lacertae during a Period of Multiwavelength activity in June 2015

11. Discovery of TeV $��$-ray emission from the neighbourhood of the supernova remnant G24.7+0.6 by MAGIC

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

13. MAGIC observations of MWC 656, the only known Be/BH system

14. Very-high-energy ��-ray observations of novae and dwarf novae with the MAGIC telescopes

15. MAGIC search for VHE $��$-ray emission from AE Aquarii in a multiwavelength context

16. Discovery of VHE gamma-ray emission from the BL Lac object B3 2247+381 with the MAGIC telescopes

17. Detection of VHE ��-rays from HESS J0632+057 during the 2011 February X-ray outburst with the MAGIC Telescopes

18. MAGIC low energy observation of GRB090102 afterglow

19. OBSERVATIONS OF THE CRAB PULSAR BETWEEN 25 AND 100 GeV WITH THE MAGIC I TELESCOPE

20. Detection of very-high energy ��-ray emission from NGC 1275 by the MAGIC telescopes

21. OBSERVATIONS OF THE CRAB PULSAR BETWEEN 25 AND 100 GeV WITH THE MAGIC I TELESCOPE.

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

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

24. Optimized dark matter searches in deep observations of Segue 1 with MAGIC.

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24 results on '"Gonz��lez, J. Becerra"'

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