Author: "Ragan, K" / Database: OpenAIRE - Searchworks@Jio Institute Digital Library Search Results

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618 results on '"Ragan, K"'

1. VERITAS discovery of very high energy gamma-ray emission from S3 1227+25 and multiwavelength observations

Author: Acharyya, A., Adams, C. B., Archer, A., Bangale, P., Benbow, W., Brill, A., Christiansen, J. L., Chromey, A. J., Errando, M., Falcone, A., Feng, Q., Finley, J. P., Foote, G. M., Fortson, L., Furniss, A., Gallagher, G., Hanlon, W., Hanna, D., Hervet, O., Hinrichs, C. E., Hoang, J., Holder, J., Jin, W., Johnson, M. N., Kaaret, P., Kertzman, M., Kieda, D., Kleiner, T. K., Korzoun, N., Krennrich, F., Lang, M. J., Lundy, M., Maier, G., McGrath, C. E., Millard, M. J., Millis, J., Mooney, C. L., Moriarty, P., Mukherjee, R., O'Brien, S., Ong, R. A., Pohl, M., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Ribeiro, D., Roache, E., Sadeh, I., Sadun, A. C., Saha, L., Santander, M., Sembroski, G. H., Shang, R., Splettstoesser, M., Talluri, A. Kaushik, Tucci, J. V., Vassiliev, V. V., Williams, D. A., Wong, S. L., Hovatta, Talvikki, Jorstad, Svetlana G., Kiehlmann, Sebastian, Lähteenmäki, Anne, Liodakis, Ioannis, Marscher, Alan P., Max-Moerbeck, Walter, Readhead, Anthony C. S., Reeves, Rodrigo, Smith, Paul S., Tornikoski, Merja, and VERITAS Collaboration
Subjects: VHE [gamma ray], model [emission], FOS: Physical sciences, GeV, power spectrum, GLAST, emission: model, blazar, emission [gamma ray], synchrotron, flux [gamma ray], optical, gamma ray: flux, High Energy Astrophysical Phenomena (astro-ph.HE), variability, imaging [detector], photon, detector: imaging, polarization: monitoring, monitoring [polarization], gamma ray: emission, gamma ray: VHE, correlation, ddc:520, spectral, VERITAS, Astrophysics - High Energy Astrophysical Phenomena, spectral energy distribution
Abstract: The astrophysical journal / 1 950(2), 152 (2023). doi:10.3847/1538-4357/acd2d0, We report the detection of very high energy gamma-ray emission from the blazar S3 1227+25 (VER J1230+253) with the Very Energetic Radiation Imaging Telescope Array System (VERITAS). VERITAS observations of the source were triggered by the detection of a hard-spectrum GeV flare on 2015 May 15 with the Fermi-Large Area Telescope (LAT). A combined 5 hr VERITAS exposure on May 16 and 18 resulted in a strong 13σ detection with a differential photon spectral index, Γ = 3.8 ± 0.4, and a flux level at 9% of the Crab Nebula above 120 GeV. This also triggered target-of-opportunity observations with Swift, optical photometry, polarimetry, and radio measurements, also presented in this work, in addition to the VERITAS and Fermi-LAT data. A temporal analysis of the gamma-ray flux during this period finds evidence of a shortest variability timescale of τ$_{obs}$ = 6.2 ± 0.9 hr, indicating emission from compact regions within the jet, and the combined gamma-ray spectrum shows no strong evidence of a spectral cutoff. An investigation into correlations between the multiwavelength observations found evidence of optical and gamma-ray correlations, suggesting a single-zone model of emission. Finally, the multiwavelength spectral energy distribution is well described by a simple one-zone leptonic synchrotron self-Compton radiation model., Published by Institute of Physics Publ., London
Published: 2023
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2. VERITAS and Fermi-LAT constraints on the Gamma-ray Emission from Superluminous Supernovae SN2015bn and SN2017egm

Author: Acharyya, A., Adams, C. B., Bangale, P., Benbow, W., Buckley, J. H., Capasso, M., Dwarkadas, V. V., Errando, M., Falcone, A., Feng, Q., Finley, J. P., Foote, G. M., Fortson, L., Furniss, A., Gallagher, G., Gent, A., Hanlon, W. F., Hervet, O., Holder, J., Humensky, T. B., Jin, W., Kaaret, P., Kertzman, M., Kherlakian, M., Kieda, D., Kleiner, T. K., Kumar, S., Lang, M. J., Lundy, M., Maier, G., McGrath, C. E., Millis, J., Moriarty, P., Mukherjee, R., Nievas-Rosillo, M., O'Brien, S., Ong, R. A., Patel, S. R., Pfrang, K., Pohl, Martin, Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Ribeiro, D., Roache, E., Ryan, J. L., Sadeh, I., Santander, M., Sembroski, G. H., Shang, R., Splettstoesser, M., Tak, D., Tucci, J. V., Weinstein, A., Williams, And D. A., Metzger, B. D., Nicholl, M., Vurm, I., and VERITAS Collaboration
Subjects: gamma ray: emission, Cherenkov Telescope Array, gamma ray: VHE, supernova, optical, TeV, VERITAS, magnetar, GeV, energy: injection, GLAST
Abstract: Superluminous supernovae (SLSNe) are a rare class of stellar explosions with luminosities ~10-100 times greater than ordinary core-collapse supernovae. One popular model to explain the enhanced optical output of hydrogen-poor (Type I) SLSNe invokes energy injection from a rapidly spinning magnetar. A prediction in this case is that high-energy gamma rays, generated in the wind nebula of the magnetar, could escape through the expanding supernova ejecta at late times (months or more after optical peak). This paper presents a search for gamma-ray emission in the broad energy band from 100 MeV to 30 TeV from two Type I SLSNe, SN2015bn, and SN2017egm, using observations from Fermi-LAT and VERITAS. Although no gamma-ray emission was detected from either source, the derived upper limits approach the putative magnetar's spin-down luminosity. Prospects are explored for detecting very-high-energy (VHE; 100 GeV - 100 TeV) emission from SLSNe-I with existing and planned facilities such as VERITAS and CTA.
Published: 2023
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3. Combined dark matter searches towards dwarf spheroidal galaxies with Fermi-LAT, HAWC, H.E.S.S., MAGIC, and VERITAS

Author: Charles, E., Di Mauro, M., Giuri, C., Salazar-Gallegos, D., Zitzer, B., Abeysekara, A. U., Albert, A., Alfaro, R., Alvarez, C., Álvarez, J. D., Angeles Camacho, J. R., Arteaga-Velázquez, J. C., Arunbabu, K. P., Avila Rojas, D., Ayala Solares, H. A., Babu, R., Baghmanyan, V., Barber, A. S., Becerra Gonzalez, J., Belmont-Moreno, E., Benzvi, S. Y., Berley, D., Brisbois, C., Caballero-Mora, K. S., Capistrán, T., Carramiñana, A., Casanova, S., Chaparro-Amaro, O., Cotti, U., Cotzomi, J., Coutiño León, S., La Fuente, E., León, C., Diaz-Cruz, L., Diaz Hernandez, R., Díaz-Vélez, J. C., Dingus, B. L., Durocher, M., Duvernois, M. A., Ellsworth, R. W., Engel, K., Espinoza, C., Fan, K. L., Fang, K., Fernández Alonso, M., Fick, B., Fleischhack, H., Flores, J. L., Fraija, N. I., Garcia, D., García-González, J. A., García-Luna, J. L., García-Torales, G., Garfias, F., Giacinti, G., Goksu, H., González, M. M., Goodman, J. A., Harding, J. P., Hernandez, S., Herzog, I., Hinton, J., Hona, B., Huang, D., Hueyotl-Zahuantitla, F., Hui, C. M., Humensky, B., Hüntemeyer, P., Iriarte, A., Jardin-Blicq, A., Jhee, H., Joshi, V., Kieda, D., Kunde, G. J., Kunwar, S., Lara, A., Lee, J., Lee, W. H., Lennarz, D., León Vargas, H., Linnemann, J., Longinotti, A. L., López-Coto, R., Luis-Raya, G., Lundeen, J., Malone, K., Marandon, V., Martinez, O., Martinez-Castellanos, I., Martínez-Huerta, H., Martínez-Castro, J., Matthews, J. A. J., Mcenery, J., Miranda-Romagnoli, P., Morales-Soto, J. A., Moreno, E., Mostafá, M., Nayerhoda, A., Nellen, L., Newbold, M., Nisa, M. U., Noriega-Papaqui, R., Olivera-Nieto, L., Omodei, N., Peisker, A., Pérez Araujo, Y., Pérez-Pérez, E. G., Rho, C. D., Rivière, C., Rosa-Gonzalez, D., Ruiz-Velasco, E., Ryan, J., Salazar, H., Salesa Greus, F., Sandoval, A., Schneider, M., Schoorlemmer, H., Serna-Franco, J., Sinnis, G., Smith, A. J., Springer, R. W., Surajbali, P., Taboada, I., Tanner, M., Tollefson, K., Torres, I., Torres-Escobedo, R., Turner, R., Ureña-Mena, F., Villaseñor, L., Wang, X., Watson, I. J., Weisgarber, T., Werner, F., Willox, E., Wood, J., Yodh, G. B., Zepeda, A., Zhou, H., Abdallah, H., Adam, R., Aharonian, F., Ait Benkhali, F., Angüner, E. O., Arcaro, C., Armand, C., Armstrong, T., Ashkar, H., Backes, M., Barbosa Martins, V., Barnacka, A., Barnard, M., Becherini, Y., Berge, D., Bernlöhr, K., Bi, B., Böttcher, M., Boisson, C., Bolmont, J., Bony Lavergne, M., Breuhaus, M., Brun, F., Brun, P., Bryan, M., Büchele, M., Bulik, T., Bylund, T., Caroff, S., Carosi, A., Chand, T., Chandra, S., Chen, A., Cotter, G., Curyło, M., Damascene Mbarubucyeye, J., Davids, I. D., Davies, J., Deil, C., Devin, J., Dewilt, P., Dirson, L., Djannati-Ataï, A., Dmytriiev, A., Donath, A., Doroshenko, V., Duffy, C., Dyks, J., Egberts, K., Eichhorn, F., Einecke, S., Emery, G., Ernenwein, J. -P, Feijen, K., Fegan, S., Fiasson, A., Fichet Clairfontaine, G., Fontaine, G., Funk, S., Füßling, M., Gabici, S., Gallant, Y. A., Giavitto, G., Giunti, L., Glawion, D., Glicenstein, J. F., Gottschall, D., Grondin, M. -H, Hahn, J., Haupt, M., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., Hörbe, M., Horns, D., Huber, D., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jung-Richardt, I., Kasai, E., Kastendieck, M. A., Katarzyński, K., Katz, U., Khangulyan, D., Khélifi, B., Klepser, S., Kluźniak, W., Komin, Nu, Konno, R., Kosack, K., Kostunin, D., Kreter, M., Lamanna, G., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P, Levy, C., Lohse, T., Lypova, I., Mackey, J., Majumdar, J., Malyshev, D., Marchegiani, P., Marcowith, A., Mares, A., Martì-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Meyer, M., Moderski, R., Mohamed, M., Mohrmann, L., Montanari, A., Moore, C., Morris, P., Moulin, E., Muller, J., Murach, T., Nakashima, K., Naurois, M., Ndiyavala, H., Niederwanger, F., Niemiec, J., Oakes, L., O’brien, P., Odaka, H., Ohm, S., Ona Wilhelmi, E., Ostrowski, M., Panter, M., Panny, S., Parsons, R. D., Peron, G., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Priyana Noel, A., Prokhorov, D. A., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reichherzer, P., Reimer, A., Reimer, O., Remy, Q., Renaud, M., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Sahakian, V., Sailer, S., Sanchez, D. A., Santangelo, A., Sasaki, M., Scalici, M., Schüssler, F., Schutte, H. M., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Senniappan, M., Seyffert, A. S., Shafi, N., Shiningayamwe, K., Simoni, R., Sinha, A., Sol, H., Specovius, A., Spencer, S., Spir-Jacob, M., Stawarz, Ł., Sun, L., Steenkamp, R., Stegmann, C., Steinmassl, S., Steppa, C., Takahashi, T., Tavernier, T., Taylor, A. M., Terrier, R., Tiziani, D., Tluczykont, M., Tomankova, L., Trichard, C., Tsirou, M., Tuffs, R., Uchiyama, Y., Walt, D. J., Eldik, C., Rensburg, C., Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Vincent, P., Vink, J., Völk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Watson, J., White, R., Wierzcholska, A., Wong, Y. W., Yusafzai, A., Zacharias, M., Zanin, R., Zargaryan, D., Zdziarski, A. A., Zech, A., Zhu, S., Zorn, J., Zouari, S., Z̀ywucka, N., Acciari, V. A., Ansoldi, S., Antonelli, L. A., Arbet Engels, A., Artero, M., Asano, K., Baack, D., Babić, A., Baquero, A., Barres Almeida, U., Barrio, J. A., Batković, I., Becerra González, J., Bednarek, W., Bellizzi, L., Bernardini, E., Bernardos, M., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bökenkamp, H., Bonnoli, G., Bošnjak, Ž, 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., Angelis, A., Lotto, B., Delfino, M., Delgado, J., Delgado Mendez, C., Depaoli, D., Di Pierro, F., Di Venere, L., Do Souto Espiñeira, E., Do-Minis Prester, D., Donini, A., Dorner, D., Doro, M., Elsaesser, D., Fallah Ramazani, V., Fattorini, A., Fonseca, M. V., Font, L., Fruck, C., Fukami, S., Fukazawa, Y., García López, R. J., Garczarczyk, M., Gasparyan, S., Gaug, M., Giglietto, N., Giordano, F., Gliwny, P., Godinović, N., Green, J. G., Green, D., Hadasch, D., Hahn, A., Heckmann, L., Herrera, J., Hoang, J., Hrupec, D., Hütten, M., Inada, T., Ishio, K., Iwamura, Y., Jiménez Martínez, I., Jormanainen, J., Jouvin, L., Karjalainen, M., Kerszberg, D., Kobayashi, Y., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Linhoff, L., Lombardi, S., Longo, F., López-Moya, M., López-Oramas, A., Loporchio, S., Machado Oliveira Fraga, B., Maggio, C., Majumdar, P., Makariev, M., Mallamaci, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Mazin, D., Menchiari, S., Mender, S., Mićanović, S., Miceli, D., Miener, T., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Morcuende, D., Moreno, V., Moretti, E., Nakamori, T., Nava, L., 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., Pavletić, L., Peñil, P., Persic, M., Pihet, M., Prada Moroni, P. G., Prandini, E., Priyadarshi, C., Puljak, I., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Sahakyan, N., Saito, T., Sakurai, S., Satalecka, K., Saturni, F. G., Schleicher, B., Schmidt, K., Schweizer, T., Sitarek, J., Šnidarić, I., Dorota Sobczynska, Spolon, A., Stamerra, A., Strišković, J., Strom, D., Strzys, M., Suda, Y., Surić, T., Takahashi, M., Takeishi, R., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Tosti, L., Truzzi, S., Tutone, A., Ubach, S., Scherpenberg, J., Vanzo, G., Vazquez Acosta, M., Ventura, S., Verguilov, V., Vigorito, C. F., Vitale, V., Vovk, I., Will, M., Wunderlich, C., Yamamoto, T., Zarić, D., Adams, C. B., Archer, A., Benbow, W., Brill, A., Buckley, J. H., Capasso, M., Christiansen, J. L., Chromey, A. J., Errando, M., Falcone, A., Farrell, A., Feng, Q., Foote, G. M., Fortson, L., Furniss, A., Gent, A., Gillanders, G. H., Gueta, O., Hanna, D., Hervet, O., Holder, J., Humensky, T. B., Jin, W., Kaaret, P., Kertzman, M., Kleiner, T. K., Kumar, S., Lang, M. J., Lundy, M., Maier, G., Mcgrath, C. E., Moriarty, P., Mukherjee, R., Nieto, D., Nievas-Rosillo, M., O’brien, S., Ong, R. A., Otte, A. N., Patel, S. R., Patel, S., Pfrang, K., Pohl, M., Prado, R. R., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Ribeiro, D., Roache, E., Ryan, J. L., Sadeh, I., Santander, M., Sembroski, G. H., Shang, R., Tak, D., Vassiliev, V. V., Weinstein, A., Williams, D. A., Williamson, T. J., Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Hess, HAWC, VERITAS, MAGIC, H.E.S.S., Fermi-LAT, Naurois , Mathieu, Ona-Wilhelmi , Emma, and Bony , Mathieu
Subjects: data analysis method, talk: Berlin 2021/07/15, FOS: Physical sciences, dark matter: signature, dark matter: direct detection, WIMP: dark matter, channel cross section: upper limit, annihilation [dark matter], GLAST, High Energy Physics - Experiment, dark matter [WIMP], WIMP: annihilation, High Energy Physics - Experiment (hep-ex), Tellurium compounds, Germanium compounds, HESS, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Dark Matter, ddc:530, annihilation [WIMP], ComputingMilieux_MISCELLANEOUS, direct detection [dark matter], High Energy Astrophysical Phenomena (astro-ph.HE), energy: high, upper limit [channel cross section], background, Gamma rays, dark matter: annihilation, Berlin 2021/07/15 [talk], sensitivity, Galaxies, Maximum likelihood estimation, MAGIC, mass dependence, Dark matter searches, high [energy], VERITAS, galaxy, signature [dark matter], Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], HAWC, experimental results
Abstract: Cosmological and astrophysical observations suggest that 85% of the total matter of the Universe is made of Dark Matter (DM). However, its nature remains one of the most challenging and fundamental open questions of particle physics. Assuming particle DM, this exotic form of matter cannot consist of Standard Model (SM) particles. Many models have been developed to attempt unraveling the nature of DM such as Weakly Interacting Massive Particles (WIMPs), the most favored particle candidates. WIMP annihilations and decay could produce SM particles which in turn hadronize and decay to give SM secondaries such as high energy γ rays. In the framework of indirect DM search, observations of promising targets are used to search for signatures of DM annihilation. Among these, the dwarf spheroidal galaxies (dSphs) are commonly favored owing to their expected high DM content and negligible astrophysical background. In this work, we present the very first combination of 20 dSph observations, performed by the Fermi-LAT, HAWC, H.E.S.S., MAGIC, and VERITAS collaborations in order to maximize the sensitivity of DM searches and improve the current results. We use a joint maximum likelihood approach combining each experiment’s individual analysis to derive more constraining upper limits on the WIMP DM self-annihilation cross-section as a function of DM particle mass. We present new DM constraints over the widest mass range ever reported, extending from 5 GeV to 100 TeV thanks to the combination of these five different γ-ray instruments., PoS: Proceedings of Science, 395, ISSN:1824-8039, Proceedings of 37th International Cosmic Ray Conference
Published: 2022
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4. Gamma-ray observations of MAXI J1820+070 during the 2018 outburst

Author: Abe, H., Abe, S., Acciari, V. A., Aniello, T., Ansoldi, S., Antonelli, L. A., Engels, A. Arbet, Arcaro, C., Artero, M., Asano, K., Baack, D., Babić, A., Baquero, A., de Almeida, U. Barres, Barrio, J. A., Batković, I., Baxter, J., González, J. Becerra, Bednarek, W., Bernardini, E., Bernardos, M., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Bošnjak, Ž., Burelli, I., Busetto, G., Carosi, R., Carretero-Castrillo, M., Ceribella, G., Chai, Y., Chilingarian, A., Cikota, S., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D'Amico, G., D'Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Del Popolo, A., Delfino, M., Delgado, J., Mendez, C. Delgado, Depaoli, D., Di Pierro, F., Di Venere, L., Dominis Prester, D., Donini, A., Dorner, D., Doro, M., Elsaesser, D., Emery, G., Fallah Ramazani, V., Fariña, L., Fattorini, A., Font, L., Fruck, C., Fukami, S., Fukazawa, Y., López, R. J. García, Garczarczyk, M., Gasparyan, S., Gaug, M., Paiva, J. G. Giesbrecht, Giglietto, N., Giordano, F., Gliwny, P., Godinović, N., Grau, R., Green, D., Green, J. G., Hadasch, D., Hahn, A., Hassan, T., Heckmann, L., Herrera, J., Hoang, J., Hrupec, D., Hütten, M., Imazawa, R., Inada, T., Iotov, R., Ishio, K., Martínez, I. Jiménez, Jormanainen, J., Kerszberg, D., Kobayashi, Y., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Linhoff, L., Lombardi, S., Longo, F., López-Coto, R., López-Moya, M., López-Oramas, A., Loporchio, S., Lorini, A., Lyard, E., de Oliveira Fraga, B. Machado, Majumdar, P., Makariev, M., Maneva, G., Mang, N., Manganaro, M., Mangano, S., Mannheim, K., Mariotti, M., Martínez, M., Aguilar, A. Mas, Mazin, D., Menchiari, S., Mender, S., Mićanović, S., Miceli, D., Miener, T., Miranda, J. M., Mirzoyan, R., Molina, E., Mondal, H. A., Moralejo, A., Morcuende, D., Moreno, V., Nakamori, T., Nanci, C., Nava, L., Neustroev, V., Nievas Rosillo, M., Nigro, C., Nilsson, K., Nishijima, K., Ekoume, T. Njoh, Noda, K., Nozaki, S., Ohtani, Y., Oka, T., Okumura, A., Otero-Santos, J., Paiano, S., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Pavletić, L., Persic, M., Pihet, M., Pirola, G., Podobnik, F., Prada Moroni, P. G., Prandini, E., Principe, G., Priyadarshi, C., Puljak, I., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Sahakyan, N., Saito, T., Sakurai, S., Satalecka, K., Saturni, F. G., Schleicher, B., Schmidt, K., Schmuckermaier, F., Schubert, J. L., Schweizer, T., Sitarek, J., Sliusar, V., Sobczynska, D., Spolon, A., Stamerra, A., Strišković, J., Strom, D., Strzys, M., Suda, Y., Surić, T., Tajima, H., Takahashi, M., Takeishi, R., Tavecchio, F., Temnikov, P., Terauchi, K., Terzić, T., Teshima, M., Tosti, L., Truzzi, S., Tutone, A., Ubach, S., van Scherpenberg, J., Vazquez Acosta, M., Ventura, S., Verguilov, V., Viale, I., Vigorito, C. F., Vitale, V., Vovk, I., Walter, R., Will, M., Wunderlich, C., Yamamoto, T., Zarić, D., Abdalla, H., Aharonian, F., Benkhali, F. Ait, Angüner, E. O., Ashkar, H., Backes, M., Baghmanyan, V., Barbosa Martins, V., Batzofin, R., Becherini, Y., Berge, D., Bernlöhr, K., Böttcher, M., Boisson, C., Bolmont, J., de Bony de Lavergne, M., Bradascio, F., Breuhaus, M., Brose, R., Brun, F., Bulik, T., Bylund, T., Cangemi, F., Caroff, S., Casanova, S., Cerruti, M., Chand, T., Chandra, S., Chen, A., Chibueze, O. U., Cotter, G., Cristofari, P., Mbarubucyeye, J. Damascene, Devin, J., Djannati-Ataï, A., Dmytriiev, A., Egberts, K., Ernenwein, J.-P., Fiasson, A., Fichet de Clairfontaine, G., Fontaine, G., Füßling, M., Funk, S., Gabici, S., Ghafourizadeh, S., Giavitto, G., Glawion, D., Glicenstein, J. F., Goswami, P., Grolleron, G., Hinton, J. A., Hörbe, M., Hoischen, C., Holch, T. L., Holler, M., Horns, D., Huang, Zhiqiu, Jamrozy, M., Jankowsky, F., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzyński, K., Katz, U., Khélifi, B., Kluźniak, W., Komin, Nu., Kosack, K., Kostunin, D., Lang, R. G., Le Stum, S., Lemière, A., Lemoine-Goumard, M., Lenain, J.-P., Leuschner, F., Lohse, T., Luashvili, A., Lypova, I., Mackey, J., Majumdar, J., Malyshev, D., Marandon, V., Marchegiani, P., Martí-Devesa, G., Marx, R., Maurin, G., Meyer, M., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., Muller, J., Murach, T., Nakashima, K., de Naurois, M., Nayerhoda, A., Niemiec, J., Noel, A. Priyana, O'Brien, P., Ohm, S., Olivera-Nieto, L., de Ona Wilhelmi, E., Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Poireau, V., Prokhorov, D. A., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Reichherzer, P., Reimer, A., Reimer, O., Renaud, M., Rieger, F., Rowell, G., Rudak, B., Ricarte, H. Rueda, Ruiz-Velasco, E., Sahakian, V., Salzmann, H., Santangelo, A., Sasaki, M., Schäfer, J., Schüssler, F., Schutte, H. M., Schwanke, U., Shapopi, J. N. S., Sol, H., Specovius, A., Spencer, S., Stawarz, Ł., Steenkamp, R., Steinmassl, S., Steppa, C., Sushch, I., Suzuki, H., Takahashi, T., Tanaka, T., Thorpe-Morgan, C., Tluczykont, M., Tomankova, L., Tsuji, N., Uchiyama, Y., van Eldik, C., van Soelen, B., Vecchi, M., Veh, J., Venter, C., Vink, J., Wagner, S. J., White, R., Wierzcholska, A., Wong, Yu Wun, Yusafzai, A., Zacharias, M., Zanin, R., Zargaryan, D., Zdziarski, A. A., Zech, A., Zhu, S. J., Zouari, S., Żywucka, N., Acharyya, A., Adams, C. B., Batista, P., Benbow, W., Capasso, M., Christiansen, J. L., Chromey, A. J., Errando, M., Falcone, A., Feng, Q., Finley, J. P., Foote, G. M., Fortson, L., Furniss, A., Gent, A., Hanlon, W. F., Hervet, O., Holder, J., Hona, B., Humensky, T. B., Jin, W., Kaaret, P., Kertzman, M., Kherlakian, M., Kleiner, T. K., Kumar, S., Lang, M. J., Lundy, M., Maier, G., McGrath, C. E., Millis, J., Moriarty, P., Mukherjee, R., O'Brien, S., Ong, R. A., Park, N., Patel, S. R., Pfrang, K., Pohl, M., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Ribeiro, D., Roache, E., Ryan, J. L., Sadeh, I., Saha, L., Santander, M., Sembroski, G. H., Shang, R., Splettstoesser, M., Tak, D., Tucci, J. V., Weinstein, A., Williams, D. A., Williamson, T. J., Bosch-Ramon, V., Celma, C., Linares, M., Russell, D. M., Sala, G., VERITAS Collaboration, H. E. S. S. Collaboration, MAGIC Collaboration, Astronomy, Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique des Deux Infinis Bordeaux (LP2I - Bordeaux), Université de Bordeaux (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Particules de Montpellier (LUPM), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), MAGIC, H.E.S.S., VERITAS, Ministerio de Ciencia e Innovación (España), European Commission, European Research Council, Federal Ministry of Education and Research (Germany), Istituto Nazionale di Astrofisica, Department of Atomic Energy (India), University of Tokyo, Ministry of Education and Science (Bulgaria), High Energy Astrophys. & Astropart. Phys (API, FNWI), and Gravitation and Astroparticle Physics Amsterdam
Subjects: individual: MAXI J1820+070 [stars], FOS: Physical sciences, X-rays: binaries, Raigs gamma, black holes [stars], gamma rays: general, stars: black holes, stars: individual: MAXI J1820+070, Estels binaris de raigs X, High Energy Astrophysical Phenomena (astro-ph.HE), Stars: individual: MAXI J1820+070 – gamma rays: general – stars: black holes – X-rays: binaries, Gamma rays, Astronomy and Astrophysics, X-ray binaries, Space and Planetary Science, HESS - Abteilung Hinton, ddc:520, binaries [X-rays], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - High Energy Astrophysical Phenomena, general [gamma rays]
Abstract: Full list of authors: Abe, H.; Abe, S.; Acciari, V. A.; Aniello, T.; Ansoldi, S.; Antonelli, L. A.; Engels, A. Arbet; Arcaro, C.; Artero, M.; Asano, K.; Baack, D.; Babic, A.; Baquero, A.; de Almeida, U. Barres; Barrio, J. A.; Batkovic, I; Baxter, J.; Gonzalez, J. Becerra; Bednarek, W.; Bernardini, E.; Bernardos, M.; Berti, A.; Besenrieder, J.; Bhattacharyya, W.; Bigongiari, C.; Biland, A.; Blanch, O.; Bonnoli, G.; Bosnjak, Z.; Burelli, I; Busetto, G.; Carosi, R.; Carretero-Castrillo, M.; Ceribella, G.; Chai, Y.; Chilingarian, A.; Cikota, S.; Colombo, E.; Contreras, J. L.; Cortina, J.; Covino, S.; D'Amico, G.; D'Elia, V; Da Vela, P.; Dazzi, F.; De Angelis, A.; De Lotto, B.; Del Popolo, A.; Delfino, M.; Delgado, J.; Mendez, C. Delgado; Depaoli, D.; Di Pierro, F.; Di Venere, L.; Prester, D. Dominis; Donini, A.; Dorner, D.; Doro, M.; Elsaesser, D.; Emery, G.; Ramazani, V. Fallah; Farina, L.; Fattorini, A.; Font, L.; Fruck, C.; Fukami, S.; Fukazawa, Y.; Lopez, R. J. Garcia; Garczarczyk, M.; Gasparyan, S.; Gaug, M.; Paiva, J. G. Giesbrecht; Giglietto, N.; Giordano, F.; Gliwny, P.; Godinovic, N.; Grau, R.; Green, D.; Green, J. G.; Hadasch, D.; Hahn, A.; Hassan, T.; Heckmann, L.; Herrera, J.; Hoang, J.; Hrupec, D.; Hutten, M.; Imazawa, R.; Inada, T.; Iotov, R.; Ishio, K.; Martinez, I. Jimenez; Jormanainen, J.; Kerszberg, D.; Kobayashi, Y.; Kubo, H.; Kushida, J.; Lamastra, A.; Lelas, D.; Leone, F.; Lindfors, E.; Linhoff, L.; Lombardi, S.; Longo, F.; Lopez-Coto, R.; Lopez-Moya, M.; Lopez-Oramas, A.; Loporchio, S.; Lorini, A.; Lyard, E.; Fraga, B. Machado de Oliveira; Majumdar, P.; Makariev, M.; Maneva, G.; Mang, N.; Manganaro, M.; Mangano, S.; Mannheim, K.; Mariotti, M.; Martinez, M.; Aguilar, A. Mas; Mazin, D.; Menchiari, S.; Mender, S.; Micanovic, S.; Miceli, D.; Miener, T.; Miranda, J. M.; Mirzoyan, R.; Molina, E.; Mondal, H. A.; Moralejo, A.; Morcuende, D.; Moreno, V; Nakamori, T.; Nanci, C.; Nava, L.; Neustroev, V; Rosillo, M. Nievas; Nigro, C.; Nilsson, K.; Nishijima, K.; Ekoume, T. Njoh; Noda, K.; Nozaki, S.; Ohtani, Y.; Oka, T.; Okumura, A.; Otero-Santos, J.; Paiano, S.; Palatiello, M.; Paneque, D.; Paoletti, R.; Paredes, J. M.; Pavletic, L.; Persic, M.; Pihet, M.; Pirola, G.; Podobnik, F.; Moroni, P. G. Prada; Prandini, E.; Principe, G.; Priyadarshi, C.; Puljak, I; Rhode, W.; Ribo, M.; Rico, J.; Righi, C.; Rugliancich, A.; Sahakyan, N.; Saito, T.; Sakurai, S.; Satalecka, K.; Saturni, F. G.; Schleicher, B.; Schmidt, K.; Schmuckermaier, F.; Schubert, J. L.; Schweizer, T.; Sitarek, J.; Sliusar, V; Sobczynska, D.; Spolon, A.; Stamerra, A.; Striskovic, J.; Strom, D.; Strzys, M.; Suda, Y.; Suric, T.; Tajima, H.; Takahashi, M.; Takeishi, R.; Tavecchio, F.; Temnikov, P.; Terauchi, K.; Terzic, T.; Teshima, M.; Tosti, L.; Truzzi, S.; Tutone, A.; Ubach, S.; van Scherpenberg, J.; Acosta, M. Vazquez; Ventura, S.; Verguilov, V.; Viale, I; Vigorito, C. F.; Vitale, V.; Vovk, I; Walter, R.; Will, M.; Wunderlich, C.; Yamamoto, T.; Zaric, D.; Abdalla, H.; Aharonian, F.; Benkhali, F. Ait; Anguner, E. O.; Ashkar, H.; Backes, M.; Baghmanyan, V; Martins, V. Barbosa; Batzofin, R.; Becherini, Y.; Berge, D.; Bernloehr, K.; Bottcher, M.; Boisson, C.; Bolmont, J.; de Lavergne, M. de Bony; Bradascio, F.; Breuhaus, M.; Brose, R.; Brun, F.; Bulik, T.; Bylund, T.; Cangemi, F.; Caroff, S.; Casanova, S.; Cerruti, M.; Chand, T.; Chandra, S.; Chen, A.; Chibueze, O. U.; Cotter, G.; Cristofari, P.; Mbarubucyeye, J. Damascene; Devin, J.; Djannati-Atai, A.; Dmytriiev, A.; Egberts, K.; Ernenwein, J-P; Fiasson, A.; de Clairfontaine, G. Fichet; Fontaine, G.; Fuessling, M.; Funk, S.; Gabici, S.; Ghafourizadeh, S.; Giavitto, G.; Glawion, D.; Glicenstein, J. F.; Goswami, P.; Grolleron, G.; Hinton, J. A.; Horbe, M.; Hoischen, C.; Holch, T. L.; Holler, M.; Horns, D.; Huang, Zhiqiu; Jamrozy, M.; Jankowsky, F.; Joshi, V; Jung-Richardt, I; Kasai, E.; Katarzynski, K.; Katz, U.; Khelifi, B.; Kluzniak, W.; Komin, Nu; Kosack, K.; Kostunin, D.; Lang, R. G.; Le Stum, S.; Lemiere, A.; Lemoine-Goumard, M.; Lenain, J-P; Leuschner, F.; Lohse, T.; Luashvili, A.; Lypova, I; Mackey, J.; Majumdar, J.; Malyshev, D.; Malyshev, D.; Marandon, V; Marchegiani, P.; Marti-Devesa, G.; Marx, R.; Maurin, G.; Meyer, M.; Mitchell, A.; Moderski, R.; Mohrmann, L.; Montanari, A.; Moulin, E.; Muller, J.; Murach, T.; Nakashima, K.; de Naurois, M.; Nayerhoda, A.; Niemiec, J.; Noel, A. Pniyana; O'Brien, P.; Ohm, S.; Olivera-Nieto, L.; Wilhelmi, E. de Ona; Ostrowski, M.; Panny, S.; Panter, M.; Parsons, R. D.; Poireau, V; Prokhorov, D. A.; Prokoph, H.; Puehlhofer, G.; Punch, M.; Quirrenbach, A.; Reichherzer, P.; Reimer, A.; Reimer, O.; Renaud, M.; Rieger, F.; Rowell, G.; Rudak, B.; Ricarte, H. Rueda; Ruiz-Velasco, E.; Sahakian, V; Salzmann, H.; Santangelo, A.; Sasaki, M.; Schaefer, J.; Schussler, F.; Schutte, H. M.; Schwanke, U.; Shapopi, J. N. S.; Sol, H.; Specovius, A.; Spencer, S.; Stawarz, L.; Steenkamp, R.; Steinmassl, S.; Steppa, C.; Sushch, I; Suzuki, H.; Takahashi, T.; Tanaka, T.; Thorpe-Morgan, C.; Tluczykont, M.; Tomankova, L.; Tsuji, N.; Uchiyama, Y.; van Eldik, C.; van Soelen, B.; Vecchi, M.; Veh, J.; Venter, C.; Vink, J.; Wagner, S. J.; White, R.; Wierzcholska, A.; Wong, Yu Wun; Yusafzai, A.; Zacharias, M.; Zanin, R.; Zargaryan, D.; Zdziarski, A. A.; Zech, A.; Zhu, S. J.; Zouari, S.; Zywucka, N.; Acharyya, A.; Adams, C. B.; Batista, P.; Benbow, W.; Capasso, M.; Christiansen, J. L.; Chromey, A. J.; Errando, M.; Falcone, A.; Feng, Q.; Finley, J. P.; Foote, G. M.; Fortson, L.; Furniss, A.; Gent, A.; Hanlon, W. E.; Hervet, O.; Holder, J.; Hona, B.; Humensky, T. B.; Jin, W.; Kaaret, P.; Kertzman, M.; Kherlakian, M.; Kleiner, T. K.; Kumar, S.; Lang, M. J.; Lundy, M.; Maier, G.; McGrath, C. E.; Millis, J.; Moriarty, P.; Mukherjee, R.; O'Brien, S.; Ong, R. A.; Park, N.; Patel, S. R.; Pfrang, K.; Pohl, M.; Pueschel, E.; Quinn, J.; Ragan, K.; Reynolds, P. T.; Ribeiro, D.; Roache, E.; Ryan, J. L.; Sadeh, I; Saha, L.; Santander, M.; Sembroski, G. H.; Shang, R.; Splettstoesser, M.; Tak, D.; Tucci, J., V; Weinstein, A.; Williams, D. A.; Williamson, T. J.; Bosch-Ramon, V; Celma, C.; Linares, M.; Russell, D. M.; Sala, G.; MAGIC Collaboration; H E S S Collaboration; VERITAS Collaboration., MAXI J1820+070 is a low-mass X-ray binary with a black hole (BH) as a compact object. This binary underwent an exceptionally bright X-ray outburst from 2018 March to October, showing evidence of a non-thermal particle population through its radio emission during this whole period. The combined results of 59.5 h of observations of the MAXI J1820+070 outburst with the H.E.S.S., MAGIC and VERITAS experiments at energies above 200 GeV are presented, together with Fermi-LAT data between 0.1 and 500 GeV, and multiwavelength observations from radio to X-rays. Gamma-ray emission is not detected from MAXI J1820+070, but the obtained upper limits and the multiwavelength data allow us to put meaningful constraints on the source properties under reasonable assumptions regarding the non-thermal particle population and the jet synchrotron spectrum. In particular, it is possible to show that, if a high-energy (HE) gamma-ray emitting region is present during the hard state of the source, its predicted flux should be at most a factor of 20 below the obtained Fermi-LAT upper limits, and closer to them for magnetic fields significantly below equipartition. During the state transitions, under the plausible assumption that electrons are accelerated up to ∼500 GeV, the multiwavelength data and the gamma-ray upper limits lead consistently to the conclusion that a potential HE and very-HE gamma-ray emitting region should be located at a distance from the BH ranging between 1011 and 1013 cm. Similar outbursts from low-mass X-ray binaries might be detectable in the near future with upcoming instruments such as CTA. © 2022 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society., MAGIC acknowledgements: MAGIC would like to thank the Instituto de Astrofísica de Canarias for the excellent working conditions at the Observatorio del Roque de los Muchachos in La Palma. The financial support of the German BMBF, MPG, and HGF; the Italian INFN and INAF; the Swiss National Fund SNF; the grants PID2019-104114RB-C31, PID2019-104114RB-C32, PID2019-104114RB-C33, PID2019-105510GB-C31, PID2019-107847RB-C41, PID2019-107847RB-C42, PID2019-107847RB-C44, PID2019-107988GB-C22 funded by MCIN/AEI/ 10.13039/501100011033; 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 DO1-400/18.12.2020 and the Academy of Finland grant nr. 320045 is gratefully acknowledged. This work was also been supported by Centros de Excelencia ‘Severo Ochoa’ y Unidades ‘María de Maeztu’ program of the MCIN/AEI/ 10.13039/501100011033 (SEV-2016-0588, SEV-2017-0709, CEX2019-000920-S, CEX2019-000918-M, MDM-2015-0509-18-2) and by the CERCA institution 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 SFB1491 and SFB876/C3; the Polish Ministry Of Education and Science grant No. 2021/WK/08; and by the Brazilian MCTIC, CNPq and FAPERJ. H.E.S.S. acknowledgements: the support of the Namibian authorities and of the University of Namibia in facilitating the construction and operation of H.E.S.S. is gratefully acknowledged, as is the support by the German Ministry for Education and Research (BMBF), the Max Planck Society, the German Research Foundation (DFG), the Helmholtz Association, the Alexander von Humboldt Foundation, the French Ministry of Higher Education, Research and Innovation, the Centre National de la Recherche Scientifique (CNRS/IN2P3 and CNRS/INSU), the Commissariat à l’énergie atomique et aux énergies alternatives (CEA), the U.K. Science and Technology Facilities Council (STFC), the Irish Research Council (IRC) and the Science Foundation Ireland (SFI), the Knut and Alice Wallenberg Foundation, the Polish Ministry of Education and Science, agreement no. 2021/WK/06, the South African Department of Science and Technology and National Research Foundation, the University of Namibia, the National Commission on Research, Science & Technology of Namibia (NCRST), the Austrian Federal Ministry of Education, Science and Research and the Austrian Science Fund (FWF), the Australian Research Council (ARC), the Japan Society for the Promotion of Science, the University of Amsterdam and the Science Committee of Armenia grant 21AG-1C085. We appreciate the excellent work of the technical support staff in Berlin, Zeuthen, Heidelberg, Palaiseau, Paris, Saclay, Tübingen and in Namibia in the construction and operation of the equipment. This work benefited from services provided by the H.E.S.S. Virtual Organisation, supported by the national resource providers of the EGI Federation. VERITAS acknowledgements: VERITAS is supported by grants from the U.S. Department of Energy Office of Science, the U.S. National Science Foundation and the Smithsonian Institution, by NSERC in Canada, and by the Helmholtz Association in Germany. This research used resources provided by the Open Science Grid, which is supported by the National Science Foundation and the U.S. Department of Energy’s Office of Science, and resources of the National Energy Research Scientific Computing Center (NERSC), a U.S. Department of Energy Office of Science User Facility operated under Contract No. DE-AC02-05CH11231. We acknowledge the excellent work of the technical support staff at the Fred Lawrence Whipple Observatory and at the collaborating institutions in the construction and operation of the instrument. E. Molina acknowledges support from MCIN through grant BES-2016-076342. V. Bosch-Ramon acknowledges financial support from the State Agency for Research of the Spanish Ministry of Science and Innovation under grant PID2019-105510GB-C31 and through the ‘Unit of Excellence María de Maeztu 2020-2023 award to the Institute of Cosmos Sciences (CEX2019-000918-M). V. Bosch-Ramon is Correspondent Researcher of CONICET, Argentina, at the IAR. M. Linares has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No. 101002352). G. Sala acknowledges support from the Spanish MINECO grant PID2020-117252GB-I00.
Published: 2022
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5. The throughput calibration of the VERITAS telescopes

Author: Adams, C. B., Benbow, W., Brill, A., Buckley, J. H., Christiansen, J. L., Falcone, A., Feng, Q., Finley, J. P., Foote, G. M., Fortson, L., Furniss, A., Giuri, C., Hanna, D., Hassan, T., Hervet, O., Holder, J., Hona, B., Humensky, T. B., Jin, W., Kaaret, P., Kleiner, T. K., Kumar, S., Lang, M. J., Lundy, M., Maier, G., Moriarty, P., Mukherjee, R., Rosillo, M. Nievas, O'Brien, S., Park, N., Patel, S., Pfrang, K., Pohl, M., Prado, R. R., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Ribeiro, D., Roache, E., Ryan, J. L., Santander, M., Weinstein, A., Williams, D. A., and Williamson, T. J.
Subjects: numerical calculations, Monte Carlo, atmosphere [Cherenkov counter], damage, time dependence, techniques: image processing, optical, mirror, High Energy Astrophysical Phenomena (astro-ph.HE), photomultiplier, image processing [techniques], performance [detector], imaging [detector], photon, Astrophysics::Instrumentation and Methods for Astrophysics, Throughput calibration, Monte Carlo [numerical calculations], detector: imaging, efficiency: quantum, time dependence [damage], astroparticle physics, VERITAS, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, numerical calculations: Monte Carlo, atmosphere [showers], efficiency, quantum, Cherenkov counter, atmosphere, detector: performance, air, Astrophysics::High Energy Astrophysical Phenomena, tube, FOS: Physical sciences, Cherenkov telescopes, Cherenkov counter: atmosphere, damage: time dependence, VHE, Instrument Response Functions, Instrumentation and Methods for Astrophysics (astro-ph.IM), quantum [efficiency], detector, imaging, showers, atmosphere, detectors [instrumentation], detector, performance, showers: atmosphere, instrumentation: detectors, telescopes, calibration, monitoring, gamma ray, ddc:520
Abstract: Astronomy and astrophysics 658, A83 (2022). doi:10.1051/0004-6361/202142275, Context. The response of imaging air Cherenkov telescopes to incident $γ$-ray-initiated showers in the atmosphere changes as the telescopes age due to exposure to light and weather. These aging processes affect the reconstructed energies of the events and $γ$-ray fluxes.Aims. This work discusses the implementation of signal calibration methods for the Very Energetic Radiation Imaging Telescope Array System (VERITAS) to account for changes in the optical throughput and detector performance over time. Methods. The total throughput of a Cherenkov telescope is the product of camera-dependent factors, such as the photomultiplier tube gains and their quantum efficiencies, and the mirror reflectivity and Winston cone response to incoming radiation. This document summarizes different methods to determine how the camera gains and mirror reflectivity have evolved over time and how we can calibrate this changing throughput in reconstruction pipelines for imaging air cherenkov telescopes. The implementation is validated against seven years of observations with the VERITAS telescopes of the Crab Nebula, which is a reference object in very-high-energy astronomy.Results. Regular optical throughput monitoring and the corresponding signal calibrations are found to be critical for the reconstruction of extensive air shower images. The proposed implementation is applied as a correction to the signals of the photomultiplier tubes in the telescope simulation to produce fine-tuned instrument response functions. This method is shown to be effective for calibrating the acquired $γ$-ray data and for recovering the correct energy of the events and photon fluxes. At the same time, it keeps the computational effort of generating Monte Carlo simulations for instrument response functions affordably low., Published by EDP Sciences, Les Ulis
Published: 2022
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6. Observation of the Gamma-Ray Binary HESS J0632+057 with the HESS, MAGIC, and VERITAS Telescopes

Author: Adams, Cb, Benbow, W, Brill, A, Buckley, Jh, Capasso, M, Chromey, Aj, Errando, M, Falcone, A, Farrell, Ka, Feng, Q, Finley, Jp, Foote, Gm, Fortson, L, Furniss, A, Gent, A, Gillanders, Gh, Giuri, C, Gueta, O, Hanna, D, Hassan, T, Hervet, O, Holder, J, Hona, B, Humensky, Tb, Jin, W, Kaaret, P, Kertzman, M, Kieda, D, Kleiner, Tk, Krennrich, F, Kumar, S, Lang, Mj, Lundy, M, Maier, G, Mcgrath, Ce, Moriarty, P, Mukherjee, R, Nieto, D, Nievas-Rosillo, M, O'Brien, S, Ong, Ra, Otte, An, Park, N, Patel, S, Pfrang, K, Pichel, A, Pohl, M, Prado, Rr, Quinn, J, Ragan, K, Reynolds, Pt, Ribeiro, D, Roache, E, Rovero, Ac, Ryan, Jl, Santander, M, Schlenstedt, S, Sembroski, Gh, Shang, R, Tak, D, Vassiliev, Vv, Weinstein, A, Williams, Da, Williamson, Tj, Acciari, Va, Ansoldi, S, Antonelli, La, Engels, Aa, Artero, M, Asano, K, Baack, D, Babic, A, Baquero, A, de Almeida, Ub, Barrio, Ja, Batkovic, I, Gonzalez, Jb, Bednarek, W, Bellizzi, L, Bernardini, E, Bernardos, M, Berti, A, Besenrieder, J, Bhattacharyya, W, Bigongiari, C, Biland, A, Blanch, O, Bokenkamp, H, Bonnoli, G, Busetto, G, Bosnjak, Z, Carosi, R, Ceribella, G, Cerruti, M, Chai, Y, Chilingarian, A, Cikota, S, Colak, Sm, Colombo, E, Contreras, Jl, 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, Cd, Depaoli, D, Di Pierro, F, Di Venere, L, Espineira, Ed, Prester, Dd, Donini, A, Dorner, D, Doro, M, Elsaesser, D, Ramazani, Vf, Fattorini, A, Fonseca, Mv, Font, L, Fruck, C, Fukami, S, Fukazawa, Y, Lopez, Rjg, Garczarczyk, M, Gasparyan, S, Gaug, M, Giglietto, N, Giordano, F, Gliwny, P, Godinovic, N, Green, Jg, Green, D, Hadasch, D, Hahn, A, Heckmann, L, Herrera, J, Hoang, J, Hrupec, D, Hutten, M, Inada, T, Ishio, K, Iwamura, Y, Martinez, Ij, Jormanainen, J, Jouvin, L, Karjalainen, M, Kerszberg, D, Kobayashi, Y, Kubo, H, Kushida, J, Lamastra, A, Lelas, D, Leone, F, Lindfors, E, Linhoff, L, Lombardi, S, Longo, F, Lopez-Coto, R, Lopez-Moya, M, Lopez-Oramas, A, Loporchio, S, Fraga, Bmd, 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, Miranda, Jm, Mirzoyan, R, Molina, E, Moralejo, A, Morcuende, D, Moreno, V, Moretti, E, Nakamori, T, Nava, L, 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, Jm, Pavletic, L, Penil, P, Persic, M, Pihet, M, Moroni, Pgp, 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, Fg, Schleicher, B, Schmidt, K, Schweizer, T, Sitarek, J, Sobczynska, D, Spolon, A, Stamerra, A, Striskovic, J, Strom, D, Strzys, M, Suda, Y, Suric, T, Takahashi, M, Takeishi, R, Tavecchio, F, Temnikov, P, Terzic, T, Teshima, M, Tosti, L, Truzzi, S, Tutone, A, Ubach, S, van Scherpenberg, J, Vanzo, G, Acosta, Mv, Ventura, S, Verguilov, V, Vigorito, Cf, Vitale, V, Vovk, I, Will, M, Wunderlich, C, Yamamoto, T, Zaric, D, Abdalla, H, Aharonian, F, Benkhali, Fa, Anguner, Eo, Arcaro, C, Ashkar, H, Backes, M, Martins, Vb, Barnard, M, Batzofin, R, Becherini, Y, Berge, D, Bernlohr, K, Bi, B, Bottcher, M, Boisson, C, Bolmont, J, de Lavergne, Md, Breuhaus, M, Brose, R, Brun, F, Bulik, T, Caroff, S, Casanova, S, Chand, T, Chen, A, Cotter, G, Mbarubucyeye, Jd, Devin, J, Djannati-Atai, A, Egberts, K, Ernenwein, Jp, Fegan, S, Fiasson, A, de Clairfontaine, Gf, Fontaine, G, Fussling, M, Funk, S, Gabici, S, Giavitto, G, Glawion, D, Glicenstein, Jf, Grondin, Mh, Hinton, Ja, Hofmann, W, Holch, Tl, Holler, M, Horns, D, Huang, Zq, Jamrozy, M, Jankowsky, F, Joshi, V, Jung-Richardt, I, Kasai, E, Katarzynski, K, Khelifi, B, Komin, N, Kosack, K, Kostunin, D, Le Stum, S, Lemiere, A, Lenain, Jp, Leuschner, F, Levy, C, Lohse, T, Luashvili, A, Lypova, I, Mackey, J, Majumdar, J, Malyshev, D, Marandon, V, Marchegiani, P, Marcowith, A, Marti-Devesa, G, Marx, R, Maurin, G, Meintjes, Pj, Mitchell, A, Moderski, R, Mohrmann, L, Montanari, A, Moulin, E, Muller, J, Murach, T, de Naurois, M, Nayerhoda, A, Niemiec, J, Noel, Ap, O'Brien, P, Ohm, S, Olivera-Nieto, L, Wilhelmi, Ed, Ostrowski, M, Panny, S, Panter, M, Parsons, Rd, Peron, G, Poireau, V, Prokhorov, Da, Prokoph, H, Puhlhofer, G, Punch, M, Quirrenbach, A, Reichherzer, P, Reimer, A, Reimer, O, Renaud, M, Rieger, F, Romoli, C, Rowell, G, Rudak, B, Ricarte, Hr, Ruiz-Velasco, E, Sahakian, V, Sailer, S, Salzmann, H, Sanchez, Da, Santangelo, A, Sasaki, M, Schutte, Hm, Schwanke, U, Schussler, F, Senniappan, M, Shapopi, Jns, Simoni, R, Sol, H, Specovius, A, Spencer, S, Steenkamp, R, Steinmassl, S, Sun, L, Takahashi, T, Tanaka, T, Terrier, R, Tsuji, N, Uchiyama, Y, van Eldik, C, van Soelen, B, Veh, J, Venter, C, Vink, J, Wagner, Sj, White, R, Wierzcholska, A, Wong, Yw, Zacharias, M, Zargaryan, D, Zdziarski, Aa, Zech, A, Zhu, Sj, Zouari, S, Zywucka, N, Moritani, Y, Torres, Df, Adams, Cb, Benbow, W, Brill, A, Buckley, Jh, Capasso, M, Chromey, Aj, Errando, M, Falcone, A, Farrell, Ka, Feng, Q, Finley, Jp, Foote, Gm, Fortson, L, Furniss, A, Gent, A, Gillanders, Gh, Giuri, C, Gueta, O, Hanna, D, Hassan, T, Hervet, O, Holder, J, Hona, B, Humensky, Tb, Jin, W, Kaaret, P, Kertzman, M, Kieda, D, Kleiner, Tk, Krennrich, F, Kumar, S, Lang, Mj, Lundy, M, Maier, G, Mcgrath, Ce, Moriarty, P, Mukherjee, R, Nieto, D, Nievas-Rosillo, M, O'Brien, S, Ong, Ra, Otte, An, Park, N, Patel, S, Pfrang, K, Pichel, A, Pohl, M, Prado, Rr, Quinn, J, Ragan, K, Reynolds, Pt, Ribeiro, D, Roache, E, Rovero, Ac, Ryan, Jl, Santander, M, Schlenstedt, S, Sembroski, Gh, Shang, R, Tak, D, Vassiliev, Vv, Weinstein, A, Williams, Da, Williamson, Tj, Acciari, Va, Ansoldi, S, Antonelli, La, Engels, Aa, Artero, M, Asano, K, Baack, D, Babic, A, Baquero, A, de Almeida, Ub, Barrio, Ja, Batkovic, I, Gonzalez, Jb, Bednarek, W, Bellizzi, L, Bernardini, E, Bernardos, M, Berti, A, Besenrieder, J, Bhattacharyya, W, Bigongiari, C, Biland, A, Blanch, O, Bokenkamp, H, Bonnoli, G, Busetto, G, Bosnjak, Z, Carosi, R, Ceribella, G, Cerruti, M, Chai, Y, Chilingarian, A, Cikota, S, Colak, Sm, Colombo, E, Contreras, Jl, 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, Cd, Depaoli, D, Di Pierro, F, Di Venere, L, Espineira, Ed, Prester, Dd, Donini, A, Dorner, D, Doro, M, Elsaesser, D, Ramazani, Vf, Fattorini, A, Fonseca, Mv, Font, L, Fruck, C, Fukami, S, Fukazawa, Y, Lopez, Rjg, Garczarczyk, M, Gasparyan, S, Gaug, M, Giglietto, N, Giordano, F, Gliwny, P, Godinovic, N, Green, Jg, Green, D, Hadasch, D, Hahn, A, Heckmann, L, Herrera, J, Hoang, J, Hrupec, D, Hutten, M, Inada, T, Ishio, K, Iwamura, Y, Martinez, Ij, Jormanainen, J, Jouvin, L, Karjalainen, M, Kerszberg, D, Kobayashi, Y, Kubo, H, Kushida, J, Lamastra, A, Lelas, D, Leone, F, Lindfors, E, Linhoff, L, Lombardi, S, Longo, F, Lopez-Coto, R, Lopez-Moya, M, Lopez-Oramas, A, Loporchio, S, Fraga, Bmd, 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, Miranda, Jm, Mirzoyan, R, Molina, E, Moralejo, A, Morcuende, D, Moreno, V, Moretti, E, Nakamori, T, Nava, L, 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, Jm, Pavletic, L, Penil, P, Persic, M, Pihet, M, Moroni, Pgp, 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, Fg, Schleicher, B, Schmidt, K, Schweizer, T, Sitarek, J, Sobczynska, D, Spolon, A, Stamerra, A, Striskovic, J, Strom, D, Strzys, M, Suda, Y, Suric, T, Takahashi, M, Takeishi, R, Tavecchio, F, Temnikov, P, Terzic, T, Teshima, M, Tosti, L, Truzzi, S, Tutone, A, Ubach, S, van Scherpenberg, J, Vanzo, G, Acosta, Mv, Ventura, S, Verguilov, V, Vigorito, Cf, Vitale, V, Vovk, I, Will, M, Wunderlich, C, Yamamoto, T, Zaric, D, Abdalla, H, Aharonian, F, Benkhali, Fa, Anguner, Eo, Arcaro, C, Ashkar, H, Backes, M, Martins, Vb, Barnard, M, Batzofin, R, Becherini, Y, Berge, D, Bernlohr, K, Bi, B, Bottcher, M, Boisson, C, Bolmont, J, de Lavergne, Md, Breuhaus, M, Brose, R, Brun, F, Bulik, T, Caroff, S, Casanova, S, Chand, T, Chen, A, Cotter, G, Mbarubucyeye, Jd, Devin, J, Djannati-Atai, A, Egberts, K, Ernenwein, Jp, Fegan, S, Fiasson, A, de Clairfontaine, Gf, Fontaine, G, Fussling, M, Funk, S, Gabici, S, Giavitto, G, Glawion, D, Glicenstein, Jf, Grondin, Mh, Hinton, Ja, Hofmann, W, Holch, Tl, Holler, M, Horns, D, Huang, Zq, Jamrozy, M, Jankowsky, F, Joshi, V, Jung-Richardt, I, Kasai, E, Katarzynski, K, Khelifi, B, Komin, N, Kosack, K, Kostunin, D, Le Stum, S, Lemiere, A, Lenain, Jp, Leuschner, F, Levy, C, Lohse, T, Luashvili, A, Lypova, I, Mackey, J, Majumdar, J, Malyshev, D, Marandon, V, Marchegiani, P, Marcowith, A, Marti-Devesa, G, Marx, R, Maurin, G, Meintjes, Pj, Mitchell, A, Moderski, R, Mohrmann, L, Montanari, A, Moulin, E, Muller, J, Murach, T, de Naurois, M, Nayerhoda, A, Niemiec, J, Noel, Ap, O'Brien, P, Ohm, S, Olivera-Nieto, L, Wilhelmi, Ed, Ostrowski, M, Panny, S, Panter, M, Parsons, Rd, Peron, G, Poireau, V, Prokhorov, Da, Prokoph, H, Puhlhofer, G, Punch, M, Quirrenbach, A, Reichherzer, P, Reimer, A, Reimer, O, Renaud, M, Rieger, F, Romoli, C, Rowell, G, Rudak, B, Ricarte, Hr, Ruiz-Velasco, E, Sahakian, V, Sailer, S, Salzmann, H, Sanchez, Da, Santangelo, A, Sasaki, M, Schutte, Hm, Schwanke, U, Schussler, F, Senniappan, M, Shapopi, Jn, Simoni, R, Sol, H, Specovius, A, Spencer, S, Steenkamp, R, Steinmassl, S, Sun, L, Takahashi, T, Tanaka, T, Terrier, R, Tsuji, N, Uchiyama, Y, van Eldik, C, van Soelen, B, Veh, J, Venter, C, Vink, J, Wagner, Sj, White, R, Wierzcholska, A, Wong, Yw, Zacharias, M, Zargaryan, D, Zdziarski, Aa, Zech, A, Zhu, Sj, Zouari, S, Zywucka, N, Moritani, Y, and Torres, Df
Subjects: Gamma ray, binaries
Abstract: The results of gamma-ray observations of the binary system HESS J0632 + 057 collected during 450 hr over 15 yr, between 2004 and 2019, are presented. Data taken with the atmospheric Cherenkov telescopes H.E.S.S., MAGIC, and VERITAS at energies above 350 GeV were used together with observations at X-ray energies obtained with Swift-XRT, Chandra, XMM-Newton, NuSTAR, and Suzaku. Some of these observations were accompanied by measurements of the H alpha emission line. A significant detection of the modulation of the very high-energy gamma-ray fluxes with a period of 316.7 +/- 4.4 days is reported, consistent with the period of 317.3 +/- 0.7 days obtained with a refined analysis of X-ray data. The analysis of data from four orbital cycles with dense observational coverage reveals short-timescale variability, with flux-decay timescales of less than 20 days at very high energies. Flux variations observed over a timescale of several years indicate orbit-to-orbit variability. The analysis confirms the previously reported correlation of X-ray and gamma-ray emission from the system at very high significance, but cannot find any correlation of optical H alpha parameters with fluxes at X-ray or gamma-ray energies in simultaneous observations. The key finding is that the emission of HESS J0632 + 057 in the X-ray and gamma-ray energy bands is highly variable on different timescales. The ratio of gamma-ray to X-ray flux shows the equality or even dominance of the gamma-ray energy range. This wealth of new data is interpreted taking into account the insufficient knowledge of the ephemeris of the system, and discussed in the context of results reported on other gamma-ray binary systems.
Published: 2021

7. VERITAS contributions to the 37th International Cosmic Ray Conference

Author: Adams, C. B., Archer, A., Benbow, W., Brill, A., Buckley, J. H., Capasso, M., Christiansen, J. L., Chromey, A. J., Errando, M., Falcone, A., Farrell, K. A., Feng, Q., Foote, G. M., Fortson, L., Furniss, A., Gent, A., Gillanders, G. H., Giuri, C., Gueta, O., Hanna, D., Hervet, O., Holder, J., Hona, B., Humensky, T. B., Jin, W., Kaaret, P., Kertzman, M., Kleiner, T. K., Kumar, S., Lang, M. J., Lundy, M., Maier, G., Mcgrath, C. E., Moriarty, P., Mukherjee, R., Nieto, D., Nievas-Rosillo, M., O Brien, S., Ong, R. A., Otte, A. N., Patel, S. R., Patel, S., Pfrang, K., Pohl, M., Prado, R. R., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Ribeiro, D., Roache, E., Ryan, J. L., Sadeh, I., Juan Marcos Santander, Sembroski, G. H., Shang, R., Tak, D., Vassiliev, V. V., Weinstein, A., Williams, D. A., and Williamson, T. J.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), FOS: Physical sciences, Astrophysics - High Energy Astrophysical Phenomena
Abstract: Compilation of papers presented by the VERITAS Collaboration at the 37th International Cosmic Ray Conference (ICRC), held July 12 through July 23, 2021 (online) in Berlin, Germany., html page. 2021 ICRC, Berlin, Germany
Published: 2021

8. The Great Markarian 421 Flare of 2010 February: 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., Arbet Engels, A., Baack, D., Babić, A., Banerjee, B., Barres de Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bellizzi, L., Bernardini, E., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Busetto, G., Carosi, R., Ceribella, G., Chai, Y., Cikota, S., Colak, S. M., Colin, U., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D’Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Di Pierro, F., Do Souto Espiñera, E., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Elsaesser, D., Fallah Ramazani, V., Fattorini, A., Fernández-Barral, A., Ferrara, G., Fidalgo, D., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., Gallozzi, S., García López, R. J., Garczarczyk, M., Gasparyan, S., Gaug, M., Godinović, N., Green, D., Guberman, D., Hadasch, D., Hahn, A., Herrera, J., Hoang, J., Hrupec, D., Inoue, S., Ishio, K., Iwamura, Y., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., López, M., López-Coto, R., López-Oramas, A., Machado de Oliveira Fraga, B., Maggio, C., Majumdar, P., Makariev, M., Mallamaci, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Masuda, S., Mazin, D., 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., Nievas Rosillo, M., Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Nöthe, M., Paiano, S., Palacio, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Peñil, P., Peresano, M., Persic, M., Prada Moroni, P. G., Prandini, E., Puljak, I., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Sahakyan, N., Saito, T., Satalecka, K., Schweizer, T., Sitarek, J., Šnidarić, I., Sobczynska, D., Somero, A., Stamerra, A., Strom, D., Strzys, M., Sun, S., Surić, T., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Torres-Albà, N., Tsujimoto, S., van Scherpenberg, J., Vanzo, G., Vazquez Acosta, M., Vovk, I., Will, M., Zarić, D., Aller, H. D., Aller, M. F., Carini, M. T., Horan, D., Jordan, B., Jorstad, S. G., Kurtanidze, O. M., Kurtanidze, S. O., Lähteenmäki, A., Larionov, V. M., Larionova, E. G., Madejski, G., Marscher, A. P., Max-Moerbeck, W., Moody, J. Ward, Morozova, D. A., Nikolashvili, M. G., Raiteri, C. M., Readhead, A. C. S., Richards, J. L., Sadun, A. C., Sakamoto, T., Sigua, L. A., Smith, P. S., Talvikki, H., Tammi, J., Tornikoski, M., Troitsky, I. S., Villata, M., (VERITAS Collaboration), (MAGIC Collaboration), (Multiwavelength Partners), Department of Energy (US), Smithsonian Institution, National Science Foundation (US), National Energy Research Scientific Computing Center (US), German Research Foundation, Istituto Nazionale di Fisica Nucleare, Istituto Nazionale di Astrofisica, Ministerio de Economía y Competitividad (España), Department of Atomic Energy (India), Japan Society for the Promotion of Science, Ministry of Education, Culture, Sports, Science and Technology (Japan), Croatian Science Foundation, University of Rijeka, Polish National Agency for Academic Exchange, National Aeronautics and Space Administration (US), Shota Rustaveli National Science Foundation, Boston University, University of Utah, Harvard University, University of California Los Angeles, Columbia University, University of Potsdam, Washington University St. Louis, California Polytechnic State University, San Luis Obispo, Iowa State University, University of Minnesota Twin Cities, Pennsylvania State University, Purdue University, California State University, East Bay, Georgia Institute of Technology, National University of Ireland, Galway, German Electron Synchrotron, University of California Santa Cruz, University of Delaware, University of Iowa, DePauw University, McGill University, Complutense University, University College Dublin, University of Wisconsin-Madison, Universidad de Buenos Aires, Cork Institute of Technology, University of Alabama, University of Chicago, Instituto de Astrofísica de Canarias, University of Udine, INAF, Osservatorio Astronomico di Roma, Swiss Federal Institute of Technology Zurich, Dortmund University, Saha Institute of Nuclear Physics, Centro Brasileiro de Pesquisas Físicas, University of Łódź, University of Siena, National Institute for Nuclear Physics, Max Planck Institute for Physics, Institute for High Energy Physics, University of Padova, University of Pisa, University of Würzburg, University of Turku, Autonomous University of Barcelona, University of Barcelona, National Academy of Sciences of the Republic of Armenia, The University of Tokyo, Bulgarian Academy of Sciences, Fudan University, University of Michigan, Ann Arbor, Western Kentucky University, CNRS, Dublin Institute for Advanced Studies, Ilia State University, Department of Electronics and Nanoengineering, St. Petersburg State University, United States Department of Energy, Universidad de Chile, Brigham Young University, California Institute of Technology, University of Colorado Denver, Aoyama Gakuin University, University of Arizona, Metsähovi Radio Observatory, Aalto-yliopisto, Aalto University, 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., Arbet Engels, A., Baack, D., Babic, A., Banerjee, B., Barres De Almeida, U., Barrio, J. A., Becerra Gonzalez, J., 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., Do Souto Espiñera, E., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Elsaesser, D., Fallah Ramazani, V., Fattorini, A., Fernandez-Barral, A., Ferrara, G., Fidalgo, D., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., Gallozzi, S., Garcia Lopez, R. J., Garczarczyk, M., Gasparyan, S., Gaug, M., Godinovic, 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., Lopez, M., Lopez-Coto, R., Lopez-Oramas, A., Machado De Oliveira Fraga, B., Maggio, C., Majumdar, P., Makariev, M., Mallamaci, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martinez, 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., Nievas Rosillo, M., Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogues, L., Nothe, M., Paiano, S., Palacio, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Peñil, P., Peresano, M., Persic, M., Prada Moroni, P. G., Prandini, E., Puljak, I., Rhode, W., Ribo, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Sahakyan, N., Saito, T., Satalecka, K., Schweizer, T., Sitarek, J., Snidaric, I., Sobczynska, D., Somero, A., Stamerra, A., Strom, D., Strzys, M., Sun, S., Suric, T., Tavecchio, F., Temnikov, P., Terzic, T., Teshima, M., Torres-Alba, N., Tsujimoto, S., Van Scherpenberg, J., Vanzo, G., Vazquez Acosta, M., Vovk, I., Will, M., Zaric, D., Aller, H. D., Aller, M. F., Carini, M. T., Horan, D., Jordan, B., Jorstad, S. G., Kurtanidze, O. M., Kurtanidze, S. O., Lahteenmaki, A., Larionov, V. M., Larionova, E. G., Madejski, G., Marscher, A. P., Max-Moerbeck, W., Moody, J. W., Morozova, D. A., Nikolashvili, M. G., Raiteri, C. M., Readhead, A. C. S., Richards, J. L., Sadun, A. C., Sakamoto, T., Sigua, L. A., Smith, P. S., Talvikki, H., Tammi, J., Tornikoski, M., Troitsky, I. S., and Villata, M.
Subjects: Multiple days, Gamma-ray astronomY, 010504 meteorology & atmospheric sciences, Astrophysics::High Energy Astrophysical Phenomena, Flux, Markarian galaxies, Astrophysics, Blazar, 01 natural sciences, 7. Clean energy, BL Lacertae object, High energy astrophysic, law.invention, law, Observatory, BL Lacertae objects, Blazars, High energy astrophysics, Relativistic jets, Gamma-ray astronomy, Time domain astronomy, Relativistic jet, 0103 physical sciences, MAGIC (telescope), BL lacertae objects, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Astronomy and Astrophysics, Light curve, Space and Planetary Science, Markarian galaxie, Electrónica, Electricidad, Flare
Abstract: We report on variability and correlation studies using multiwavelength observations of the blazar Mrk 421 during the month of 2010 February, when an extraordinary flare reaching a level of ∼27 Crab Units above 1 TeV was measured in very high energy (VHE) γ-rays with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) observatory. This is the highest flux state for Mrk 421 ever observed in VHE γ-rays. Data are analyzed from a coordinated campaign across multiple instruments, including VHE γ-ray (VERITAS, Major Atmospheric Gamma-ray Imaging Cherenkov), high-energy γ-ray (Fermi-LAT), X-ray (Swift, Rossi X-ray Timing Experiment, MAXI), optical (including the GASP-WEBT collaboration and polarization data), and radio (Metsahovi, Owens Valley Radio Observatory, University of Michigan Radio Astronomy Observatory). 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 ∼25-55 minutes, the first time-lagged correlation between these bands reported on such short timescales. Limits on the Doppler factor (δ ⪆ 33) and the size of the emission region (δR≲ 3.8 × 10cm) 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 anticorrelation. Taken together, these detailed observations of an unprecedented flare seen in Mrk 421 are difficult to explain with the classic single-zone synchrotron self-Compton model., This research is supported by grants from the U.S. Department of Energy Office of Science, the U.S. National Science Foundation, the Smithsonian Institution, and NSERC in Canada. This research used resources provided by the Open Science Grid, which is supported by the National Science Foundation and the U.S. Department of Energy’s Office of Science, and the National Energy Research Scientific Computing Center (NERSC), a U.S. Department of Energy Office of Science User Facility operated under contract No. DE-AC02- 05CH11231. We acknowledge the excellent work of the technical support staff at the Fred Lawrence Whipple Observatory and the collaborating institutions in the construction and operation of the instrument. The MAGIC collaboration would like to thank the Instituto de Astrofísica de Canarias for the excellent working conditions at the Observatorio del Roque de los Muchachos in La Palma. The financial support of the German BMBF and MPG, the Italian INFN and INAF, the Swiss National Fund SNF, the ERDF under the Spanish MINECO (FPA2015-69818-P, FPA2012-36668, FPA2015-68378-P, FPA2015-69210-C6-2- R, FPA2015-69210-C6-4-R, FPA2015-69210-C6-6-R, AYA2015-71042-P, AYA2016-76012-C3-1-P, ESP2015- 71662-C2-2-P, FPA201790566REDC), the Indian Department of Atomic Energy, the Japanese JSPS and MEXT, and the Bulgarian Ministry of Education and Science, National RI Roadmap Project DO1-153/28.08.2018 is gratefully acknowledged. This work was also supported by the Spanish Centro de Excelencia “Severo Ochoa” SEV-2016-0588 and SEV2015-0548 and Unidad de Excelencia “María de Maeztu” MDM-2014-0369, the Croatian Science Foundation (HrZZ) Project IP-2016-06-9782, the University of Rijeka Project 13.12.1.3.02, the DFG Collaborative Research Centers SFB823/C4 and SFB876/C3, the Polish National Research Centre grant UMO-2016/22/M/ST9/00382, and the Brazilian MCTIC, CNPq, and FAPERJ. This publication makes use of data obtained at Metsähovi Radio Observatory, operated by Aalto University, Finland, and the OVRO 40 m monitoring program, which is supported in part by NASA grants NNX08AW31G, NNX11A043G, and NNX14AQ89G and NSF grants AST-0808050 and AST1109911. The UMRAO data were obtained through NSF grant AST 0607523 and NASA Fermi GI award NNX09AU16G. The St. Petersburg University team acknowledges support from Russian RFBR foundation, grant 12-02-00452. The Abastumani Observatory team acknowledges financial support by the Shota Rustaveli National Science Foundation through project FR/577/6-320/13. The Steward Observatory data were obtained under Fermi Guest Investigator Program grant NNX09AU10G. The research at Boston University is supported by NASA grant 80NSSC17K0649 and NSF grant AST-1615796. Software. VEGAS (Cogan 2008), Event Display (Daniel 2008), MARS (Moralejo et al. 2009), Fermi Science Tools81, HEASoft (FTOOLS+XANADU; HEASARC 2014), REX,85 Xspec (Arnaud 1996), emcee (Foreman-Mackey et al. 2013).
Published: 2020

9. Observation of the Gamma-Ray Binary HESS J0632+057 with the H.E.S.S., MAGIC, and VERITAS Telescopes

Author: Adams, C. B., Benbow, W., Finley, J. P., 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., M Foote, G., Mendez, C. Delgado, Depaoli, D., Di Pierro, F., Di Venere, L., Espiñeira, E. Do Souto, Prester, D. Dominis, Donini, A., Dorner, D., Doro, M., Elsaesser, D., Fortson, L., Ramazani, V. Fallah, Fattorini, A., Fonseca, M. V., Font, L., Fruck, C., Fukami, S., Fukazawa, Y., López, R. J. García, Garczarczyk, M., Gasparyan, S., Furniss, A., Gaug, M., Giglietto, N., Giordano, F., Gliwny, P., Godinović, N., Green, J. G., Green, D., Hadasch, D., Hahn, A., Heckmann, L., Gent, A., Herrera, J., Hoang, J., Hrupec, D., Hütten, M., Inada, T., Ishio, K., Iwamura, Y., Martínez, I. Jiménez, Jormanainen, J., Jouvin, L., Gillanders, G. H., Karjalainen, M., Kerszberg, D., Kobayashi, Y., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Linhoff, L., Giuri, C., Lombardi, S., Longo, F., López-Coto, R., López-Moya, M., López-Oramas, A., Loporchio, S., Fraga, B. Machado de Oliveira, Maggio, C., Majumdar, P., Makariev, M., Gueta, O., Mallamaci, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Mazin, D., Menchiari, S., Mender, S., Hanna, D., Mićanović, S., Miceli, D., Miener, T., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Morcuende, D., Moreno, V., Moretti, E., Hassan, T., Nakamori, T., Nava, L., Neustroev, V., Nigro, C., Nilsson, K., Nishijima, K., Nozaki, K. Noda S., Ohtani, Y., Oka, T., Otero-Santos, J., Brill, A., Hervet, O., Paiano, S., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Pavletić, L., Peñil, P., Persic, M., Pihet, M., Moroni, P. G. Prada, Holder, J., Prandini, E., Priyadarshi, C., Puljak, I., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Sahakyan, N., Hona, B., Saito, T., Sakurai, S., Satalecka, K., Saturni, F. G., Schleicher, B., Schmidt, K., Schweizer, T., Sitarek, J., Šnidarić, I., Spolon, D. Sobczynska A., Humensky, T. B., Stamerra, A., Strišković, J., Strom, D., Strzys, M., Suda, Y., Surić, T., Takahashi, M., Takeishi, R., Tavecchio, F., Temnikov, P., Jin, W., Terzić, T., Teshima, M., Tosti, L., Truzzi, S., Tutone, A., Ubach, S., van Scherpenberg, J., Vanzo, G., Acosta, M. Vazquez, Ventura, S., Kaaret, P., Verguilov, V., Vigorito, C. F., Vitale, V., Vovk, I., Will, M., Wunderlich, C., Yamamoto, T., Zarić, D., Abdalla, H., Aharonian, F., Kertzman, M., Ait-Benkhali, F., Angüner, E. O., Arcaro, C., Ashkar, H., Backes, M., Martins, V. Barbosa, Barnard, M., Batzofin, R., Becherini, Y., Berge, D., Kieda, D., Bernloehr, K., Bi, B., Boettcher, M., Boisson, C., Bolmont, J., de Bony de Lavergne, M., Breuhaus, M., Brose, R., Brun, F., Bulik, T., Kleiner, T. K., Caroff, S., Casanova, S., Chand, T., Chen, A., Cotter, G., Damascenev Mbarubucyeye, J., Devin, J., Djannati-Atai, A., Egberts, K., Ernenwein, J. P., Krennrich, F., Fegan, S., Fiasson, A., de Clairfontaine, G. Fichet, Fontaine, G., Fuessling, M., Funk, S., Gabici, S., Giavitto, G., Glawion, D., Glicenstein, J. F., Buckley, J. H., Kumar, S., Grondin, M. H., Hinton, J. A., Hofmann, W., Holch, T. L., Holler, M., Horns, D., Huang, Zhiqiu, Jamrozy, M., Jankowsky, F., Joshi, V., Lang, M. J., Jung-Richardt, I., Kasai, E., Katarzynski, K., Khelifi, B., Komin, Nu., Kosack, K., Kostunin, D., Stum, S. Le, Lemiere, A., Lenain, J. P., Lundy, M., Leuschner, F., Levy, C., Lohse, T., Luashvili, A., Lypova, I., Mackey, J., Majumdar, J., Malyshev, D., Marandon, V., Marchegiani, P., Maier, G., Marcowith, A., Marti'i-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., McGrath, C. E., Muller, J., Murach, T., de Naurois, M., Nayerhoda, A., Niemiec, J., Priyana Noel, A., O'Brien, P., Ohm, S., Olivera-Nieto, L., de Ona-Wilhelmi, E., Moriarty, P., Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Peron, G., Poireau, V., Prokhorov, D. A., Prokoph, H., Puehlhofer, G., Punch, M., Mukherjee, R., Quirrenbach, A., Reichherzer, P., Reimer, A., Reimer, O., Renaud, M., Rieger, F., Romoli, C., Rowell, G., Rudak, B., Ricarte, H. Rueda, Nieto, D., Velasco, E. Ruiz, Sahakian, V., Sailer, S., Salzmann, H., Sanchez, D. A., Santangelo, A., Sasaki, M., Schutte, H. M., Schwanke, U., Schuessler, F., Nievas-Rosillo, M., Senniappan, M., Shapopi, J. N. S., Simoni, R., Sol, H., Specovius, A., Spencer, S., Steenkamp, R., Steinmassl, S., Sun, L., Takahashi, T., O'Brien, S., Tanaka, T., Terrier, R., Tsuji, N., Uchiyama, Y., van Eldik, C., van Soelen, B., Veh, J., Venter, C., Vink, J., Wagner, S. J., Capasso, M., Ong, R. A., White, R., Wierzcholska, A., Wun Wong, Yu, Zacharias, M., Zargaryan, D., Zdziarski, A. A., Zech, A., Zhu, S. J., Zouari, S., Zywucka, N., Otte, A. N., Moritani, Y., Torres, D. F., VERITAS Collaboration, MAGIC Collaboration, H. E. S. S. Collaboration, Park, N., Patel, S., Pfrang, K., Pichel, A., Pohl, M., Prado, R. R., Quinn, J., Ragan, K., Chromey, A. J., Reynolds, P. T., Ribeiro, D., Roache, E., Rovero, A. C., Ryan, J. L., Santander, M., Schlenstedt, S., Sembroski, G. H., Shang, R., Tak, D., Errando, M., Vassiliev, V. V., Weinstein, A., Williams, D. A., Williamson, T. J., Acciari, V. A., Ansoldi, S., Antonelli, L. A., Engels, A. Arbet, Artero, M., Asano, K., Falcone, A., Baack, D., Babić, A., Baquero, A., de Almeida, U. Barres, Barrio, J. A., Batković, I., González, J. Becerra, Bednarek, W., Bellizzi, L., Bernardini, E., Farrell, K. A., Bernardos, M., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bökenkamp, H., Bonnoli, G., Bošnjak, Ž., Feng, Q., Busetto, G., Carosi, R., Ceribella, G., Cerruti, M., Chai, Y., Chilingarian, A., Cikota, S., Colak, S. M., Colombo, E., Contreras, J. L., Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Particules de Montpellier (LUPM), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), VERITAS, MAGIC, and H.E.S.S.
Subjects: electron: acceleration, atmosphere [Cherenkov counter], Astrophysics::High Energy Astrophysical Phenomena, VHE [gamma ray], FOS: Physical sciences, energy [gamma ray], Cherenkov counter: atmosphere, GeV, GLAST, emission [gamma ray], HESS, flux [gamma ray], optical, gamma ray: flux, X-ray: flux, gamma ray: energy, orbit, pulsar, acceleration [electron], High Energy Astrophysical Phenomena (astro-ph.HE), X-ray: energy spectrum, flux [X-ray], background, energy spectrum [X-ray], gamma ray: binary, radio wave: detector, sensitivity, MAGIC, detector [radio wave], modulation, gamma ray: emission, binary [gamma ray], gamma ray: VHE, correlation, ddc:520, gamma-ray binaries — binaries: general — gamma rays:stars — Xrays: binaries — stars: individual (HESSJ0632+057), VERITAS, Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: The astrophysical journal 923(2), 241 (2021). doi:10.3847/1538-4357/ac29b7, The results of gamma-ray observations of the binary system HESS J0632 + 057 collected during 450 hr over 15 yr, between 2004 and 2019, are presented. Data taken with the atmospheric Cherenkov telescopes H.E.S.S., MAGIC, and VERITAS at energies above 350 GeV were used together with observations at X-ray energies obtained with Swift-XRT, Chandra, XMM-Newton, NuSTAR, and Suzaku. Some of these observations were accompanied by measurements of the H�� emission line. A significant detection of the modulation of the very high-energy gamma-ray fluxes with a period of 316.7 �� 4.4 days is reported, consistent with the period of 317.3 �� 0.7 days obtained with a refined analysis of X-ray data. The analysis of data from four orbital cycles with dense observational coverage reveals short-timescale variability, with flux-decay timescales of less than 20 days at very high energies. Flux variations observed over a timescale of several years indicate orbit-to-orbit variability. The analysis confirms the previously reported correlation of X-ray and gamma-ray emission from the system at very high significance, but cannot find any correlation of optical H�� parameters with fluxes at X-ray or gamma-ray energies in simultaneous observations. The key finding is that the emission of HESS J0632 + 057 in the X-ray and gamma-ray energy bands is highly variable on different timescales. The ratio of gamma-ray to X-ray flux shows the equality or even dominance of the gamma-ray energy range. This wealth of new data is interpreted taking into account the insufficient knowledge of the ephemeris of the system, and discussed in the context of results reported on other gamma-ray binary systems., Published by Univ., Chicago, Ill. [u.a.]
Published: 2021
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10. Observation of the Gamma-Ray Binary HESS J0632+057 with the H.E.S.S., MAGIC, and VERITAS Telescopes

Author: Adams, C. B., Benbow, W., Brill, A., Buckley, J. H., Capasso, M., Chromey, A. J., Errando, M., Falcone, A., A Farrell, K., Feng, Q., Finley, J. P., M Foote, G., Fortson, L., Furniss, A., Gent, A., Gillanders, G. H., Giuri, C., Gueta, O., Hanna, D., Hassan, T., Hervet, O., Holder, J., Hona, B., Humensky, T. B., Jin, W., Kaaret, P., Kertzman, M., Kieda, D., K Kleiner, T., Krennrich, F., Kumar, S., Lang, M. J., Lundy, M., Maier, G., E McGrath, C., Moriarty, P., Mukherjee, R., Nieto, D., Nievas-Rosillo, M., O'Brien, S., Ong, R. A., Otte, A. N., Park, N., Patel, S., Pfrang, K., Pichel, A., Pohl, M., Prado, R. R., Quinn, J., Ragan, K., Reynolds, P. T., Ribeiro, D., Roache, E., Rovero, A. C., Ryan, J. L., Santander, M., Schlenstedt, S., Sembroski, G. H., Shang, R., Tak, D., Vassiliev, V. V., Weinstein, A., Williams, D. A., J Williamson, T., Acciari, V. A., Ansoldi, S., ANTONELLI, Lucio Angelo, Arbet Engels, A., Artero, M., Asano, K., Baack, D., Babić, A., Baquero, A., Barres De Almeida, U., Barrio, J. A., Batković, I., Becerra González, J., Bednarek, W., Bellizzi, L., Bernardini, E., Bernardos, M., Berti, A., Besenrieder, J., Bhattacharyya, W., BIGONGIARI, Ciro, Biland, A., Blanch, O., Bökenkamp, H., Bonnoli, G., Bošnjak, Busetto, G., Carosi, R., Ceribella, G., Cerruti, M., Chai, Y., Chilingarian, A., Cikota, S., Colak, S. M., Colombo, E., Contreras, J. L., COVINO, Stefano, D'ELIA, Valerio, DAZZI , FRANCESCO, DEPAOLI, DAVIDE, DONINI, ALICE, GREEN, JARRED GERSHON, LAMASTRA, Alessandra, LEONE, FRANCESCO, LOMBARDI, Saverio, Nava, Lara, PAIANO, Simona, PERSIC, Massimo, PRANDINI, ELISA, Righi, Chiara, SATURNI, FRANCESCO GABRIELE, SPOLON, ALESSIA, STAMERRA, Antonio, TAVECCHIO, Fabrizio, and TUTONE, ANTONIO
Subjects: Astrophysics::High Energy Astrophysical Phenomena
Abstract: The results of gamma-ray observations of the binary system HESS J0632 + 057 collected during 450 hr over 15 yr, between 2004 and 2019, are presented. Data taken with the atmospheric Cherenkov telescopes H.E.S.S., MAGIC, and VERITAS at energies above 350 GeV were used together with observations at X-ray energies obtained with Swift-XRT, Chandra, XMM-Newton, NuSTAR, and Suzaku. Some of these observations were accompanied by measurements of the Hα emission line. A significant detection of the modulation of the very high-energy gamma-ray fluxes with a period of 316.7 4.4 days is reported, consistent with the period of 317.3 0.7 days obtained with a refined analysis of X-ray data. The analysis of data from four orbital cycles with dense observational coverage reveals short-timescale variability, with flux-decay timescales of less than 20 days at very high energies. Flux variations observed over a timescale of several years indicate orbit-to-orbit variability. The analysis confirms the previously reported correlation of X-ray and gamma-ray emission from the system at very high significance, but cannot find any correlation of optical Hα parameters with fluxes at X-ray or gamma-ray energies in simultaneous observations. The key finding is that the emission of HESS J0632 + 057 in the X-ray and gamma-ray energy bands is highly variable on different timescales. The ratio of gamma-ray to X-ray flux shows the equality or even dominance of the gamma-ray energy range. This wealth of new data is interpreted taking into account the insufficient knowledge of the ephemeris of the system, and discussed in the context of results reported on other gamma-ray binary systems.
Published: 2021

11. Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign

Author: Algaba, J.C. Anczarski, J. Asada, K. Baloković, M. Chandra, S. Cui, Y.-Z. Falcone, A.D. Giroletti, M. Goddi, C. Hada, K. Haggard, D. Jorstad, S. Kaur, A. Kawashima, T. Keating, G. Kim, J.-Y. Kino, M. Komossa, S. Kravchenko, E.V. Krichbaum, T.P. Lee, S.-S. Lu, R.-S. Lucchini, M. Markoff, S. Neilsen, J. Nowak, M.A. Park, J. Principe, G. Ramakrishnan, V. Reynolds, M.T. Sasada, M. Savchenko, S.S. Williamson, K.E. Akiyama, K. Alberdi, A. Alef, W. Anantua, R. Azulay, R. Baczko, A.-K. Ball, D. Barrett, J. Bintley, D. Benson, B.A. Blackburn, L. Blundell, R. Boland, W. Bouman, K.L. Bower, G.C. Boyce, H. Bremer, M. Brinkerink, C.D. Brissenden, R. Britzen, S. Broderick, A.E. Broguiere, D. Bronzwaer, T. Byun, D.-Y. Carlstrom, J.E. Chael, A. Chan, C.-K. Chatterjee, S. Chatterjee, K. Chen, M.-T. Chen, Y. Chesler, P.M. Cho, I. Christian, P. Conway, J.E. Cordes, J.M. Crawford, T.M. Crew, G.B. Cruz-Osorio, A. Davelaar, J. De Laurentis, M. Deane, R. Dempsey, J. Desvignes, G. Dexter, J. Doeleman, S.S. Eatough, R.P. Falcke, H. Farah, J. Fish, V.L. Fomalont, E. Ford, H.A. Fraga-Encinas, R. Friberg, P. Fromm, C.M. Fuentes, A. Galison, P. Gammie, C.F. García, R. Gentaz, O. Georgiev, B. Gold, R. Gómez, J.L. Gómez-Ruiz, A.I. Gu, M. Gurwell, M. Hecht, M.H. Hesper, R. Ho, L.C. Ho, P. Honma, M. Huang, C.-W.L. Huang, L. Hughes, D.H. Ikeda, S. Inoue, M. Issaoun, S. James, D.J. Jannuzi, B.T. Janssen, M. Jeter, B. Jiang, W. Jiménez-Rosales, A. Johnson, M.D. Jung, T. Karami, M. Karuppusamy, R. Kettenis, M. Kim, D.-J. Kim, J. Kim, J. Koay, J.Y. Kofuji, Y. Koch, P.M. Koyama, S. Kramer, M. Kramer, C. Kuo, C.-Y. Lauer, T.R. Levis, A. Li, Y.-R. Li, Z. Lindqvist, M. Lico, R. Lindahl, G. Liu, J. Liu, K. Liuzzo, E. Lo, W.-P. Lobanov, A.P. Loinard, L. Lonsdale, C. Macdonald, N.R. Mao, J. Marchili, N. Marrone, D.P. Marscher, A.P. Martí-Vidal, I. Matsushita, S. Matthews, L.D. Medeiros, L. Menten, K.M. Mizuno, I. Mizuno, Y. Moran, J.M. Moriyama, K. Moscibrodzka, M. Müller, C. Musoke, G. Mejías, A.M. Nagai, H. Nagar, N.M. Nakamura, M. Narayan, R. Narayanan, G. Natarajan, I. Nathanail, A. Neri, R. Ni, C. Noutsos, A. Okino, H. Olivares, H. Ortiz-León, G.N. Oyama, T. Ozel, F. Palumbo, D.C.M. Patel, N. Pen, U.-L. Pesce, D.W. Piétu, V. Plambeck, R. Popstefanija, A. Porth, O. Pötzl, F.M. Prather, B. Preciado-López, J.A. Psaltis, D. Pu, H.-Y. Rao, R. Rawlings, M.G. Raymond, A.W. Rezzolla, L. Ricarte, A. Ripperda, B. Roelofs, F. Rogers, A. Ros, E. Rose, M. Roshanineshat, A. Rottmann, H. Roy, A.L. Ruszczyk, C. Rygl, K.L.J. Sánchez, S. Sánchez-Arguelles, D. Savolainen, T. Schloerb, F.P. Schuster, K.-F. Shao, L. Shen, Z. Small, D. Sohn, B.W. Soohoo, J. Sun, H. Tazaki, F. Tetarenko, A.J. Tiede, P. Tilanus, R.P.J. Titus, M. Toma, K. Torne, P. Trent, T. Traianou, E. Trippe, S. Van Bemmel, I. Van Langevelde, H.J. Van Rossum, D.R. Wagner, J. Ward-Thompson, D. Wardle, J. Weintroub, J. Wex, N. Wharton, R. Wielgus, M. Wong, G.N. Wu, Q. Yoon, D. Young, A. Young, K. Younsi, Z. Yuan, F. Yuan, Y.-F. Zensus, J.A. Zhao, G.-Y. Zhao, S.-S. Principe, G. Giroletti, M. D'Ammando, F. Orienti, M. Abdalla, H. Adam, R. Aharonian, F. Benkhali, F.A. Angüner, E.O. Arcaro, C. Armand, C. Armstrong, T. Ashkar, H. Backes, M. Baghmanyan, V. Barbosa Martins, V. Barnacka, A. Barnard, M. Becherini, Y. Berge, D. Bernlöhr, K. Bi, B. Böttcher, M. Boisson, C. Bolmont, J. De Bony De Lavergne, M. Breuhaus, M. Brun, F. Brun, P. Bryan, M. Büchele, M. Bulik, T. Bylund, T. Caroff, S. Carosi, A. Casanova, S. Chand, T. Chen, A. Cotter, G. Curyło, M. Damascene Mbarubucyeye, J. Davids, I.D. Davies, J. Deil, C. Devin, J. Dewilt, P. Dirson, L. Djannati-Ataï, A. Dmytriiev, A. Donath, A. Doroshenko, V. Duffy, C. Dyks, J. Egberts, K. Eichhorn, F. Einecke, S. Emery, G. Ernenwein, J.-P. Feijen, K. Fegan, S. Fiasson, A. De Clairfontaine, G.F. Fontaine, G. Funk, S. Füßling, M. Gabici, S. Gallant, Y.A. Giavitto, G. Giunti, L. Glawion, D. Glicenstein, J.F. Gottschall, D. Grondin, M.-H. Hahn, J. Haupt, M. Hermann, G. Hinton, J.A. Hofmann, W. Hoischen, C. Holch, T.L. Holler, M. Hörbe, M. Horns, D. Huber, D. Jamrozy, M. Jankowsky, D. Jankowsky, F. Jardin-Blicq, A. Joshi, V. Jung-Richardt, I. Kasai, E. Kastendieck, M.A. Katarzyński, K. Katz, U. Khangulyan, D. Khélifi, B. Klepser, S. Kluźniak, W. Komin, N. Konno, R. Kosack, K. Kostunin, D. Kreter, M. Lamanna, G. Lemiere, A. Lemoine-Goumard, M. Lenain, J.-P. Levy, C. Lohse, T. Lypova, I. Mackey, J. Majumdar, J. Malyshev, D. Malyshev, D. Marandon, V. Marchegiani, P. Marcowith, A. Mares, A. Martí-Devesa, G. Marx, R. Maurin, G. Meintjes, P.J. Meyer, M. Moderski, R. Mohamed, M. Mohrmann, L. Montanari, A. Moore, C. Morris, P. Moulin, E. Muller, J. Murach, T. Nakashima, K. Nayerhoda, A. De Naurois, M. Ndiyavala, H. Niederwanger, F. Niemiec, J. Oakes, L. O'Brien, P. Odaka, H. Ohm, S. Olivera-Nieto, L. De Ona Wilhelmi, E. Ostrowski, M. Panter, M. Panny, S. Parsons, R.D. Peron, G. Peyaud, B. Piel, Q. Pita, S. Poireau, V. Noel, A.P. Prokhorov, D.A. Prokoph, H. Pühlhofer, G. Punch, M. Quirrenbach, A. Rauth, R. Reichherzer, P. Reimer, A. Reimer, O. Remy, Q. Renaud, M. Rieger, F. Rinchiuso, L. Romoli, C. Rowell, G. Rudak, B. Ruiz-Velasco, E. Sahakian, V. Sailer, S. Sanchez, D.A. Santangelo, A. Sasaki, M. Scalici, M. Schutte, H.M. Schwanke, U. Schwemmer, S. Seglar-Arroyo, M. Senniappan, M. Seyffert, A.S. Shafi, N. Shiningayamwe, K. Simoni, R. Sinha, A. Sol, H. Specovius, A. Spencer, S. Spir-Jacob, M. Stawarz, Ł. Sun, L. Steenkamp, R. Stegmann, C. Steinmassl, S. Steppa, C. Takahashi, T. Tavernier, T. Taylor, A.M. Terrier, R. Tiziani, D. Tluczykont, M. Tomankova, L. Trichard, C. Tsirou, M. Tuffs, R. Uchiyama, Y. Van Der Walt, D.J. Van Eldik, C. Van Rensburg, C. Van Soelen, B. Vasileiadis, G. Veh, J. Venter, C. Vincent, P. Vink, J. Völk, H.J. Vuillaume, T. Wadiasingh, Z. Wagner, S.J. Watson, J. Werner, F. White, R. Wierzcholska, A. Wong, Y.W. Yusafzai, A. Zacharias, M. Zanin, R. Zargaryan, D. Zdziarski, A.A. Zech, A. Zhu, S.J. Zorn, J. Zouari, S. Żywucka, N. Acciari, V.A. Ansoldi, S. Antonelli, L.A. Engels, A.A. Artero, M. Asano, K. Baack, D. Babić, A. Baquero, A. De Almeida, U.B. Barrio, J.A. Becerra González, J. Bednarek, W. Bellizzi, L. Bernardini, E. Bernardos, M. Berti, A. Besenrieder, J. Bhattacharyya, W. Bigongiari, C. Biland, A. Blanch, O. Bonnoli, G. Bošnjak, Ž. Busetto, G. Carosi, R. Ceribella, G. Cerruti, M. Chai, Y. Chilingarian, A. Cikota, S. 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. García López, R.J. Garczarczyk, M. Gasparyan, S. Gaug, M. Giglietto, N. Giordano, F. Gliwny, P. Godinović, N. Green, J.G. Green, D. Hadasch, D. Hahn, A. Heckmann, L. Herrera, J. Hoang, J. Hrupec, D. Hütten, M. Inada, T. Inoue, S. Ishio, K. Iwamura, Y. Jiménez, 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. López-Coto, R. López-Moya, M. López-Oramas, A. Loporchio, S. Machado De Oliveira Fraga, B. Maggio, C. Majumdar, P. Makariev, M. Mallamaci, M. Maneva, G. Manganaro, M. Mannheim, K. Maraschi, L. Mariotti, M. Martínez, M. Mazin, D. Menchiari, S. Mender, S. Mićanović, S. Miceli, D. Miener, T. Minev, M. Miranda, J.M. Mirzoyan, R. Molina, E. Moralejo, A. Morcuende, D. Moreno, V. Moretti, E. 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. Pavletić, L. Penil, P. Perennes, C. Persic, M. Moroni, P.G.P. Prandini, E. Priyadarshi, C. Puljak, I. Rhode, W. Ribó, M. Rico, J. Righi, C. Rugliancich, A. Saha, L. Sahakyan, N. Saito, T. Sakurai, S. Satalecka, K. Saturni, F.G. Schleicher, B. Schmidt, K. Schweizer, T. Sitarek, J. Šnidarić, I. Sobczynska, D. Spolon, A. Stamerra, A. Strom, D. Strzys, M. Suda, Y. Surić, T. Takahashi, M. Tavecchio, F. Temnikov, P. Terzić, T. Teshima, M. 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. Zarić, D. Adams, C.B. Benbow, W. Brill, A. Capasso, M. Christiansen, J.L. Chromey, A.J. Daniel, M.K. Errando, M. Farrell, K.A. Feng, Q. Finley, J.P. Fortson, L. Furniss, A. Gent, A. Giuri, C. Hassan, T. Hervet, O. Holder, J. Hughes, G. Humensky, T.B. Jin, W. Kaaret, P. Kertzman, M. Kieda, D. Kumar, S. Lang, M.J. Lundy, M. Maier, G. Moriarty, P. Mukherjee, R. Nieto, D. Nievas-Rosillo, M. O'Brien, S. Ong, R.A. Otte, A.N. Patel, S. Pfrang, K. Pohl, M. Prado, R.R. Pueschel, E. Quinn, J. Ragan, K. Reynolds, P.T. Ribeiro, D. Richards, G.T. Roache, E. Rulten, C. Ryan, J.L. Santander, M. Sembroski, G.H. Shang, R. Weinstein, A. Williams, D.A. Williamson, T.J. Hirota, T. Cui, L. Niinuma, K. Ro, H. Sakai, N. Sawada-Satoh, S. Wajima, K. Wang, N. Liu, X. Yonekura, Y.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Cosmology and Extragalactic Astrophysics
Abstract: In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations for a weakly accreting supermassive black hole of mass ∼6.5 × 109 M o˙. The EHTC also partnered with several international facilities in space and on the ground, to arrange an extensive, quasi-simultaneous multi-wavelength campaign. This Letter presents the results and analysis of this campaign, as well as the multi-wavelength data as a legacy data repository. We captured M87 in a historically low state, and the core flux dominates over HST-1 at high energies, making it possible to combine core flux constraints with the more spatially precise very long baseline interferometry data. We present the most complete simultaneous multi-wavelength spectrum of the active nucleus to date, and discuss the complexity and caveats of combining data from different spatial scales into one broadband spectrum. We apply two heuristic, isotropic leptonic single-zone models to provide insight into the basic source properties, but conclude that a structured jet is necessary to explain M87's spectrum. We can exclude that the simultaneous γ-ray emission is produced via inverse Compton emission in the same region producing the EHT mm-band emission, and further conclude that the γ-rays can only be produced in the inner jets (inward of HST-1) if there are strongly particle-dominated regions. Direct synchrotron emission from accelerated protons and secondaries cannot yet be excluded. © 2021. The Author(s). Published by the American Astronomical Society..
Published: 2021

12. The throughput calibration of the VERITAS telescopes

Author: Nievas Rosillo, Mireia, Adams, C., Falcone, A., Farrell, K. A., Feng, Q., Foote, G. M., Fortson, L., Furniss, A., Gent, A., Gillanders, G. H., Giuri, C., Gueta, O., Archer, A., Hanna, D., Hervet, O., Holder, J., Hona, B., Humensky, T. B., Jin, W., Kaaret, P., Kertzman, M., Kieda, D., Kleiner, T. K., Benbow, W., Kumar, S., Lang, M., Lundy, M., Maier, G., McGrath, C. E., Moriarty, P., Mukherjee, R., Nieto, D., O'Brien, S., Ong, R. A., Brill, A., Otte, A., R. Patel, S., Patel, S. R., Pfrang, K., Pohl, M., Prado, R., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Buckley, J. H., Ribeiro, D., Roache, E., Ryan, J. A., Sadeh, I., Santander, M., Sembroski, G. H., Shang, R., Tak, D., Vassiliev, V., Weinstein, A., Capasso, M., Williams, D. A., Williamson, T. J., VERITAS Collaboration, Christiansen, J., Chromey, A. J., and Errando, M.
Subjects: detector: performance, 010504 meteorology & atmospheric sciences, air, atmosphere [Cherenkov counter], Astrophysics::High Energy Astrophysical Phenomena, Monte Carlo method, FOS: Physical sciences, Cherenkov counter: atmosphere, 01 natural sciences, energy: threshold, Cherenkov [radiation], 0103 physical sciences, optical, Calibration, ddc:530, mirror, 010303 astronomy & astrophysics, Throughput (business), Instrumentation and Methods for Astrophysics (astro-ph.IM), Cherenkov radiation, 0105 earth and related environmental sciences, Remote sensing, photomultiplier, showers: atmosphere, performance [detector], imaging [detector], Detector, Astrophysics::Instrumentation and Methods for Astrophysics, Monte Carlo [numerical calculations], detector: imaging, threshold [energy], radiation: Cherenkov, calibration, Crab Nebula, efficiency, Environmental science, VERITAS, numerical calculations: Monte Carlo, Astrophysics - Instrumentation and Methods for Astrophysics, Energy (signal processing), atmosphere [showers]
Abstract: 37th International Cosmic Ray Conference, ICRC 2021, Berlin, online, Germany, 12 Jul 2021 - 23 Jul 2021; Proceedings of Science / International School for Advanced Studies (ICRC2021), 721 (2021). doi:10.22323/1.395.0721, Imaging atmospheric Cherenkov telescopes are continuously exposed to varying weather condi- tions that have short and long-term effects on their response to Cherenkov light from extensive air showers. This work presents the implementation of a throughput calibration method for the VERITAS telescopes taking into account changes in the optical response and detector performance over time. Different methods to measure the total throughput of the instrument, which depend on mirror reflectivites and PMT camera gain and efficiency, are discussed as well as the effect of its evolution on energy thresholds, effective collection areas, and energy reconstruction. The application of this calibration in the VERITAS data analysis chain is discussed, including the validation using Monte Carlo simulations and observations of the Crab Nebula., Published by SISSA, Trieste
Published: 2021
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13. The throughput calibration of the VERITAS telescopes

Author: Adams, C. B., Benbow, W., Brill, A., Buckley, J. H., Christiansen, J. L., Falcone, A., Feng, Q., Finley, J. P., Foote, G. M., Fortson, L., Furniss, A., Giuri, C., Hanna, D., Hassan, T., Hervet, O., Holder, J., Hona, B., Humensky, T. B., Jin, W., Kaaret, P., Kleiner, T. K., Kumar, S., Lang, M. J., Lundy, M., Maier, G., Moriarty, P., Mukherjee, R., Rosillo, M. Nievas, O'Brien, S., Park, N., Patel, S., Pfrang, K., Pohl, M., Prado, R. R., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Ribeiro, D., Roache, E., Ryan, J. L., Santander, M., Weinstein, A., Williams, D. A., and Williamson, T. J.
Subjects: efficiency, quantum, numerical calculations, Monte Carlo, Cherenkov counter, atmosphere, showers, atmosphere, photomultiplier, detector, performance, air, Astrophysics::High Energy Astrophysical Phenomena, tube, photon, Astrophysics::Instrumentation and Methods for Astrophysics, Throughput calibration, damage, time dependence, Cherenkov telescopes, calibration, VHE, monitoring, Instrument Response Functions, optical, VERITAS, mirror, detector, imaging
Abstract: Context. The response of imaging atmospheric Cherenkov telescopes to incident {\gamma}-ray-initiated showers in the atmosphere changes as the telescopes age due to exposure to light and weather. These aging processes affect the reconstructed energies of the events and {\gamma}-ray fluxes. Aims. This work discusses the implementation of signal calibration methods for the Very Energetic Radiation Imaging Telescope Array System (VERITAS) to account for changes in the optical throughput and detector performance over time. Methods. The total throughput of a Cherenkov telescope is the product of camera-dependent factors, such as the photomultiplier tube gains and their quantum efficiencies, and the mirror reflectivity and Winston cone response to incoming radiation. This document summarizes different methods to determine how the camera gains and mirror reflectivity have evolved over time and how we can calibrate this changing throughput in reconstruction pipelines for imaging atmospheric Cherenkov telescopes. The implementation is validated against seven years of observations with the VERITAS telescopes of the Crab Nebula, which is a reference object in very-high-energy astronomy. Results. Regular optical throughput monitoring and the corresponding signal calibrations are found to be critical for the reconstruction of extensive air shower images. The proposed implementation is applied as a correction to the signals of the photomultiplier tubes in the telescope simulation to produce fine-tuned instrument response functions. This method is shown to be effective for calibrating the acquired {\gamma}-ray data and for recovering the correct energy of the events and photon fluxes. At the same time, it keeps the computational effort of generating Monte Carlo simulations for instrument response functions affordably low.
Published: 2021
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14. 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
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15. The Great Markarian 421 flare of 2010 February:multiwavelength variability and correlation studies

Author: Abeysekara, A. U. (A. U.), Benbow, W. (W.), Bird, R. (R.), Brill, A. (A.), Brose, R. (R.), Buchovecky, M. (M.), Buckley, J. H. (J. H.), Christiansen, J. L. (J. L.), Chromey, A. J. (A. J.), Daniel, M. K. (M. K.), Dumm, J. (J.), Falcone, A. (A.), Feng, Q. (Q.), Finley, J. P. (J. P.), Fortson, L. (L.), Furniss, A. (A.), Galante, N. (N.), Gent, A. (A.), Gillanders, G. H. (G. H.), Giuri, C. (C.), Gueta, O. (O.), Hassan, T. (T.), Hervet, O. (O.), Holder, J. (J.), Hughes, G. (G.), Humensky, T. B. (T. B.), Johnson, C. A. (C. A.), Kaaret, P. (P.), Kar, P. (P.), Kelley-Hoskins, N. (N.), Kertzman, M. (M.), Kieda, D. (D.), Krause, M. (M.), Krennrich, F. (F.), Kumar, S. (S.), Lang, M. J. (M. J.), Moriarty, P. (P.), Mukherjee, R. (R.), Nelson, T. (T.), Nieto, D. (D.), Nievas-Rosillo, M. (M.), O'Brien, S. (S.), Ong, R. A. (R. A.), Otte, A. N. (A. N.), Park, N. (N.), Petrashyk, A. (A.), Pichel, A. (A.), Pohl, M. (M.), Prado, R. R. (R. R.), Pueschel, E. (E.), Quinn, J. (J.), Ragan, K. (K.), Reynolds, P. T. (P. T.), Richards, G. T. (G. T.), Roache, E. (E.), Rovero, A. C. (A. C.), Rulten, C. (C.), Sadeh, I. (I), Santander, M. (M.), Sembroski, G. H. (G. H.), Shahinyan, K. (K.), Stevenson, B. (B.), Sushch, I. (I), Tyler, J. (J.), Vassiliev, V. V. (V. V.), Wakely, S. P. (S. P.), Weinstein, A. (A.), Wells, R. M. (R. M.), Wilcox, P. (P.), Wilhelm, A. (A.), Williams, D. A. (D. A.), Zitzer, B. (B.), Acciari, V. A. (V. A.), Ansoldi, S. (S.), Antonelli, L. A. (L. A.), Engels, A. A. (A. Arbet), Baack, D. (D.), Babic, A. (A.), Banerjee, B. (B.), Barres de Almeida, U. (U.), Barrio, J. A. (J. A.), Becerra Gonzalez, J. (J.), Bednarek, W. (W.), Bellizzi, L. (L.), Bernardini, E. (E.), Berti, A. (A.), Besenrieder, J. (J.), Bhattacharyya, W. (W.), Bigongiari, C. (C.), Biland, A. (A.), Blanch, O. (O.), Bonnoli, G. (G.), Busetto, G. (G.), Carosi, R. (R.), Ceribella, G. (G.), Chai, Y. (Y.), Cikota, S. (S.), Colak, S. M. (S. M.), Colin, U. (U.), Colombo, E. (E.), Contreras, J. L. (J. L.), Cortina, J. (J.), Covino, S. (S.), D'Elia, V. (V), Vela, P. (P.), Dazzi, F. (F.), De Angelis, A. (A.), De Lotto, B. (B.), Delfino, M. (M.), Delgado, J. (J.), Di Pierro, F. (F.), Souto Espinera, E. (E.), Prester, D. D. (D. Dominis), Dorner, D. (D.), Doro, M. (M.), Einecke, S. (S.), Elsaesser, D. (D.), Ramazani, V. F. (V. Fallah), Fattorini, A. (A.), Fernandez-Barral, A. (A.), Ferrara, G. (G.), Fidalgo, D. (D.), Foffano, L. (L.), Fonseca, M. V. (M., V), Font, L. (L.), Fruck, C. (C.), Galindo, D. (D.), Gallozzi, S. (S.), Garcia Lopez, R. J. (R. J.), Garczarczyk, M. (M.), Gasparyan, S. (S.), Gaug, M. (M.), Godinovic, N. (N.), Green, D. (D.), Guberman, D. (D.), Hadasch, D. (D.), Hahn, A. (A.), Herrera, J. (J.), Hoang, J. (J.), Hrupec, D. (D.), Inoue, S. (S.), Ishio, K. (K.), Iwamura, Y. (Y.), Kubo, H. (H.), Kushida, J. (J.), Lamastra, A. (A.), Lelas, D. (D.), Leone, F. (F.), Lindfors, E. (E.), Lombardi, S. (S.), Longo, F. (F.), Lopez, M. (M.), Lopez-Coto, R. (R.), Lopez-Oramas, A. (A.), Machado de Oliveira Fraga, B. (B.), Maggio, C. (C.), Majumdar, P. (P.), Makariev, M. (M.), Mallamaci, M. (M.), Maneva, G. (G.), Manganaro, M. (M.), Mannheim, K. (K.), Maraschi, L. (L.), Mariotti, M. (M.), Martinez, M. (M.), Masuda, S. (S.), Mazin, D. (D.), Miceli, D. (D.), Minev, M. (M.), Miranda, J. M. (J. M.), Mirzoyan, R. (R.), Molina, E. (E.), Moralejo, A. (A.), Morcuende, D. (D.), Moreno, V. (V), Moretti, E. (E.), Munar-Adrover, P. (P.), Neustroev, V. (V), Niedzwiecki, A. (A.), Nievas Rosillo, M. (M.), Nigro, C. (C.), Nilsson, K. (K.), Ninci, D. (D.), Nishijima, K. (K.), Noda, K. (K.), Nogues, L. (L.), Noethe, M. (M.), Paiano, S. (S.), Palacio, J. (J.), Palatiello, M. (M.), Paneque, D. (D.), Paoletti, R. (R.), Paredes, J. M. (J. M.), Penil, P. (P.), Peresano, M. (M.), Persic, M. (M.), Moroni, P. G. (P. G. Prada), Prandini, E. (E.), Puljak, I. (I), Rhode, W. (W.), Ribo, M. (M.), Rico, J. (J.), Righi, C. (C.), Rugliancich, A. (A.), Saha, L. (L.), Sahakyan, N. (N.), Saito, T. (T.), Satalecka, K. (K.), Schweizer, T. (T.), Sitarek, J. (J.), Snidaric, I. (I), Sobczynska, D. (D.), Somero, A. (A.), Stamerra, A. (A.), Strom, D. (D.), Strzys, M. (M.), Sun, S. (S.), Suric, T. (T.), Tavecchio, F. (F.), Temnikov, P. (P.), Terzic, T. (T.), Teshima, M. (M.), Torres-Alba, N. (N.), Tsujimoto, S. (S.), van Scherpenberg, J. (J.), Vanzo, G. (G.), Vazquez Acosta, M. (M.), Vovk, I. (I), Will, M. (M.), Zaric, D. (D.), Aller, H. D. (H. D.), Aller, M. F. (M. F.), Carini, M. T. (M. T.), Horan, D. (D.), Jordan, B. (B.), Jorstad, S. G. (S. G.), Kurtanidze, O. M. (O. M.), Kurtanidze, S. O. (S. O.), Lahteenmaki, A. (A.), Larionov, V. M. (V. M.), Larionova, E. G. (E. G.), Madejski, G. (G.), Marscher, A. P. (A. P.), Max-Moerbeck, W. (W.), Moody, J. W. (J. Ward), Morozova, D. A. (D. A.), Nikolashvili, M. G. (M. G.), Raiteri, C. M. (C. M.), Readhead, A. C. (A. C. S.), Richards, J. L. (J. L.), Sadun, A. C. (A. C.), Sakamoto, T. (T.), Sigua, L. A. (L. A.), Smith, P. S. (P. S.), Talvikki, H. (H.), Tammi, J. (J.), Tornikoski, M. (M.), Troitsky, I. S. (I. S.), and Villata, M. (M.)
Subjects: Gamma-ray astronomy, Astrophysics::High Energy Astrophysical Phenomena, Time domain astronomy, BL Lacertae objects, Markarian galaxies, Relativistic jets, High energy astrophysics, Blazars
Abstract: We report on variability and correlation studies using multiwavelength observations of the blazar Mrk 421 during the month of 2010 February, when an extraordinary flare reaching a level of ~27 Crab Units above 1 TeV was measured in very high energy (VHE) γ-rays with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) observatory. This is the highest flux state for Mrk 421 ever observed in VHE γ-rays. Data are analyzed from a coordinated campaign across multiple instruments, including VHE γ-ray (VERITAS, Major Atmospheric Gamma-ray Imaging Cherenkov), high-energy γ-ray (Fermi-LAT), X-ray (Swift, Rossi X-ray Timing Experiment, MAXI), optical (including the GASP-WEBT collaboration and polarization data), and radio (Metsähovi, Owens Valley Radio Observatory, University of Michigan Radio Astronomy Observatory). 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 ~25–55 minutes, the first time-lagged correlation between these bands reported on such short timescales. Limits on the Doppler factor (δ ≳ 33) and the size of the emission region (δ⁻¹ RB ≲ × 10¹³ 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 anticorrelation. Taken together, these detailed observations of an unprecedented flare seen in Mrk 421 are difficult to explain with the classic single-zone synchrotron self-Compton model.
Published: 2020

16. VERITAS Detection of LS 5039 and HESS J1825-137

Author: Abeysekara, A. U., Benbow, W., Bird, R., Brose, R., Christiansen, J. L., Chromey, A. J., Cui, W., Daniel, M. K., Falcone, A., Fortson, L., Hanna, D., Hassan, T., Hervet, O., Holder, J., Hughes, G., Humensky, T. B., Kaaret, P., Kar, P., Kelley-Hoskins, Nathan, Kertzman, M., Kieda, D., Krause, Maria, Lang, M. J., Maier, Gernot, Moriarty, P., Nieto, D., Nievas-Rosillo, M., Ong, R. A., Pandel, D., Pohl, Martin, Prado, R. R., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Richards, G. T., Roache, E., Sadeh, I., Santander, M., Sembroski, G. H., Weinstein, A., Wilcox, P., Williams, D. A., and Williamson, T. J.
Subjects: flux, inverse scattering method, gamma ray: VHE, star, HESS, gamma ray: binary, VERITAS, statistical, pulsar
Abstract: Astroparticle physics 117, 102403 - (2020). doi:10.1016/j.astropartphys.2019.102403, With 8 h of observations, VERITAS confirms the detection of two very high energy gamma-ray sources. The gamma-ray binary LS 5039 is detected with a statistical significance of 8.8 σ . The measured flux above 1 TeV is (2.5±0.4)×10−12cm−2s−1 near inferior conjunction and (7.8±2.8)×10−13cm−2s−1 near superior conjunction. The pulsar wind nebula HESS J1825-137 is detected with a statistical significance of 6.7 σ and a measured flux above 1 TeV of (3.9±0.8)×10−12cm−2s−1 ., Published by Elsevier Science, Amsterdam [u.a.]
Published: 2020
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17. VERITAS and Fermi-LAT Observations of TeV Gamma-Ray Sources Discovered by HAWC in the 2HWC Catalog

Author: Abeysekara, A. U., Archer, A., Benbow, W., Bird, R., Brose, R., Buchovecky, M., Buckley, J. H., Bugaev, V., Chromey, A. J., Connolly, M. P., Cui, W., Michael Daniel, Falcone, A., Feng, Q., Finley, J. P., Fortson, L., Furniss, A., Hütten, M., Hanna, D., Hervet, O., Holder, J., Hughes, G., Humensky, T. B., Johnson, C. A., Kaaret, P., Kar, P., Kertzman, M., Kieda, D., Krause, M., Krennrich, F., Kumar, S., Lang, M. J., Lin, T. T. Y., Mcarthur, S., 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., Reynolds, P. T., Richards, G. T., Roache, E., Rulten, C., Sadeh, I., Santander, M., Sembroski, G. H., Shahinyan, K., Sushch, I., Tyler, J., Wakely, S. P., Weinstein, A., Wells, R. M., Wilcox, P., Wilhelm, A., Williams, D. A., Williamson, T. J., Zitzer, B., Veritas, The Collaboration, Abdollahi, S., Ajello, M., Baldini, L., Barbiellini, G., Bastieri, D., Bellazzini, R., Berenji, B., Bissaldi, E., Blandford, R. D., Bonino, R., Bottacini, E., Brandt, T. J., Bruel, P., Buehler, R., Cameron, R. A., Caputo, R., Caraveo, P. A., Castro, D., Cavazzuti, E., Charles, E., Chiaro, G., Ciprini, S., Cohen-Tanugi, J., Costantin, D., Cutini, S., D’ammando, F., Palma, F., Di Lalla, N., Di Mauro, M., Di Venere, L., Domínguez, A., Favuzzi, C., Fegan, S. J., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Green, D., Grenier, I. A., Guillemot, L., Guiriec, S., Hays, E., Hewitt, J. W., Horan, D., Jóhannesson, G., Kensei, S., Kuss, M., Larsson, S., Latronico, L., Lemoine-Goumard, M., Li, J., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Magill, J. D., Maldera, S., Mazziotta, M. N., Mcenery, J. E., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Negro, M., Nuss, E., Ojha, R., Omodei, N., Orienti, M., Orlando, E., Palatiello, M., Paliya, V. S., Paneque, D., Perkins, J. S., Persic, M., Pesce-Rollins, M., Petrosian, V., Piron, F., Porter, T. A., Principe, G., Rainò, S., Rando, R., Rani, B., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reposeur, T., Sgrò, C., Siskind, E. J., Spandre, G., Spinelli, P., Suson, D. J., Tajima, H., Thayer, J. B., Thompson, D. J., Torres, D. F., Tosti, G., Troja, E., Valverde, J., Vianello, G., Vogel, M., Wood, K., Yassine, M., The Fermi-LAT Collaboration, Alfaro, R., Álvarez, C., Álvarez, J. D., Arceo, R., Arteaga-Velázquez, J. C., Avila Rojas, D., Ayala Solares, H. A., Becerril, A., Belmont-Moreno, E., Benzvi, S. Y., Bernal, A., Braun, J., Brisbois, C., Caballero-Mora, K. S., Capistrán, T., Carramiñana, A., Casanova, S., Castillo, M., Cotti, U., Cotzomi, J., Coutiño León, S., León, C., La Fuente, E., Dichiara, S., Dingus, B. L., Duvernois, M. A., Díaz-Vélez, J. C., Engel, K., Enriquez-Rivera, O., Fiorino, D. W., Fleischhack, H., Fraija, N., García-González, J. A., Garfias, F., González Muñoz, A., González, M. M., Goodman, J. A., Hampel-Arias, Z., Harding, J. P., Hernandez, S., Hernandez-Almada, A., Hona, B., Hueyotl-Zahuantitla, F., Hui, C. M., Hüntemeyer, P., Iriarte, A., Jardin-Blicq, A., Joshi, V., Kaufmann, S., Lara, A., Lauer, R. J., Lee, W. H., Lennarz, D., León Vargas, H., Linnemann, J. T., Longinotti, A. L., Luis-Raya, G., Luna-García, R., López-Coto, R., Malone, K., Marinelli, S. S., Martinez, O., Martinez-Castellanos, I., Martínez-Castro, J., Martínez-Huerta, H., Matthews, J. A., Miranda-Romagnoli, P., Moreno, E., Mostafá, M., Nayerhoda, A., Nellen, L., Newbold, M., Nisa, M. U., Noriega-Papaqui, R., Pelayo, R., Pretz, J., Pérez-Pérez, E. G., Ren, Z., Rho, C. D., Rivière, C., Rosa-González, D., Rosenberg, M., Ruiz-Velasco, E., Salazar, H., Salesa Greus, F., Sandoval, A., Schneider, M., Seglar Arroyo, M., Sinnis, G., Smith, A. J., Springer, R. W., Surajbali, P., Taboada, I., Tibolla, O., Tollefson, K., Torres, I., Ukwatta, T. N., Villaseñor, L., Weisgarber, T., Westerhoff, S., Wisher, I. G., Wood, J., Yapici, T., Yodh, G., Zepeda, A., Zhou, H., Hawc, The Collaboration, Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Particules de Montpellier (LUPM), Université de Montpellier (UM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Unité Scientifique de la Station de Nançay (USN), Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), VERITAS, Fermi-LAT, HAWC, Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Abeysekara, A. U., Archer, A., Benbow, W., Bird, R., Brose, R., Buchovecky, M., Buckley, J. H., Bugaev, V., Chromey, A. J., Connolly, M. P., Cui, W., Daniel, M. K., Falcone, A., Feng, Q., Finley, J. P., Fortson, L., Furniss, A., Hutten, M., Hanna, D., Hervet, O., Holder, J., Hughes, G., Humensky, T. B., Johnson, C. A., Kaaret, P., Kar, P., Kertzman, M., Kieda, D., Krause, M., Krennrich, F., Kumar, S., Lang, M. J., Lin, T. T. Y., Mcarthur, S., 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., Reynolds, P. T., Richards, G. T., Roache, E., Rulten, C., Sadeh, I., Santander, M., Sembroski, G. H., Shahinyan, K., Sushch, I., Tyler, J., Wakely, S. P., Weinstein, A., Wells, R. M., Wilcox, P., Wilhelm, A., Williams, D. A., Williamson, T. J., Zitzer, B., Abdollahi, S., Ajello, M., Baldini, L., Barbiellini, G., Bastieri, D., Bellazzini, R., Berenji, B., Bissaldi, E., Blandford, R. D., Bonino, R., Bottacini, E., Brandt, T. J., Bruel, P., Buehler, R., Cameron, R. A., Caputo, R., Caraveo, P. A., Castro, D., Cavazzuti, E., Charles, E., Chiaro, G., Ciprini, S., Cohen-Tanugi, J., Costantin, D., Cutini, S., D'Ammando, F., DE PALMA, Francesco, Lalla, N. D., Mauro, M. D., Venere, L. D., Dominguez, A., Favuzzi, C., Fegan, S. J., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Green, D., Grenier, I. A., Guillemot, L., Guiriec, S., Hays, E., Hewitt, J. W., Horan, D., Johannesson, G., Kensei, S., Kuss, M., Larsson, S., Latronico, L., Lemoine-Goumard, M., Li, J., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Magill, J. D., Maldera, S., Mazziotta, M. N., Mcenery, J. E., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Negro, M., Nuss, E., Ojha, R., Omodei, N., Orienti, M., Orlando, E., Palatiello, M., Paliya, V. S., Paneque, D., Perkins, J. S., Persic, M., Pesce-Rollins, M., Petrosian, V., Piron, F., Porter, T. A., Principe, G., Raino, S., Rando, R., Rani, B., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reposeur, T., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Suson, D. J., Tajima, H., Thayer, J. B., Thompson, D. J., Torres, D. F., Tosti, G., Troja, E., Valverde, J., Vianello, G., Vogel, M., Wood, K., Yassine, M., Alfaro, R., Alvarez, C., Alvarez, J. D., Arceo, R., Arteaga-Velazquez, J. C., Rojas, D. A., Solares, H. A. A., Becerril, A., Belmont-Moreno, E., Benzvi, S. Y., Bernal, A., Braun, J., Brisbois, C., Caballero-Mora, K. S., Capistran, T., Carraminana, A., Casanova, S., Castillo, M., Cotti, U., Cotzomi, J., De Leon, S. C., Leon, C. D., Fuente, E. D. L., Dichiara, S., Dingus, B. L., Duvernois, M. A., Diaz-Velez, J. C., Engel, K., Enriquez-Rivera, O., Fiorino, D. W., Fleischhack, H., Fraija, N., Garcia-Gonzalez, J. A., Garfias, F., Munoz, A. G., Gonzalez, M. M., Goodman, J. A., Hampel-Arias, Z., Harding, J. P., Hernandez, S., Hernandez-Almada, A., Hona, B., Hueyotl-Zahuantitla, F., Hui, C. M., Huntemeyer, P., Iriarte, A., Jardin-Blicq, A., Joshi, V., Kaufmann, S., Lara, A., Lauer, R. J., Lee, W. H., Lennarz, D., Vargas, H. L., Linnemann, J. T., Longinotti, A. L., Luis-Raya, G., Luna-Garcia, R., Lopez-Coto, R., Malone, K., Marinelli, S. S., Martinez, O., Martinez-Castellanos, I., Martinez-Castro, J., Martinez-Huerta, H., Matthews, J. A., Miranda-Romagnoli, P., Moreno, E., Mostafa, M., Nayerhoda, A., Nellen, L., Newbold, M., Nisa, M. U., Noriega-Papaqui, R., Pelayo, R., Pretz, J., Perez-Perez, E. G., Ren, Z., Rho, C. D., Riviere, C., Rosa-Gonzalez, D., Rosenberg, M., Ruiz-Velasco, E., Salazar, H., Greus, F. S., Sandoval, A., Schneider, M., Arroyo, M. S., Sinnis, G., Smith, A. J., Springer, R. W., Surajbali, P., Taboada, I., Tibolla, O., Tollefson, K., Torres, I., Ukwatta, T. N., Villasenor, L., Weisgarber, T., Westerhoff, S., Wisher, I. G., Wood, J., Yapici, T., Yodh, G., Zepeda, A., Zhou, H., ITA, PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Hütten, M., Palma, F. De, Lalla, N. Di, Mauro, M. Di, Venere, L. Di, Jóhannesson, G., Arteaga-Velázquez, J. C., Rojas, D. Avila, Solares, H. A. Ayala, Capistrán, T., De León, S. Coutino, León, C. De, Fuente, E. De La, Diaz-Vélez, J. C., Garcia-González, J. A., Munoz, A. González, González, M. M., Hüntemeyer, P., Vargas, H. León, López-Coto, R., Mostafá, M., Pérez-Pérez, E. G., Rosa-González, D., Greus, F. Salesa, and Arroyo, M. Seglar
Subjects: Physics, High energy, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Institut für Physik und Astronomie, Astronomy and Astrophysics, Astrophysics, gamma rays: general, Astronomy and Astrophysic, 01 natural sciences, Pulsar wind nebula, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], 0103 physical sciences, ddc:520, ddc:530, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, general [gamma rays], Cherenkov radiation, Fermi Gamma-ray Space Telescope
Abstract: International audience; The High Altitude Water Cherenkov (HAWC) collaboration recently published their 2HWC catalog, listing 39 very high energy (VHE; >100 GeV) gamma-ray sources based on 507 days of observation. Among these, 19 sources are not associated with previously known teraelectronvolt (TeV) gamma-ray sources. We have studied 14 of these sources without known counterparts with VERITAS and Fermi-LAT. VERITAS detected weak gamma-ray emission in the 1 TeV–30 TeV band in the region of DA 495, a pulsar wind nebula coinciding with 2HWC J1953+294, confirming the discovery of the source by HAWC. We did not find any counterpart for the selected 14 new HAWC sources from our analysis of Fermi-LAT data for energies higher than 10 GeV. During the search, we detected gigaelectronvolt (GeV) gamma-ray emission coincident with a known TeV pulsar wind nebula, SNR G54.1+0.3 (VER J1930+188), and a 2HWC source, 2HWC J1930+188. The fluxes for isolated, steady sources in the 2HWC catalog are generally in good agreement with those measured by imaging atmospheric Cherenkov telescopes. However, the VERITAS fluxes for SNR G54.1+0.3, DA 495, and TeV J2032+4130 are lower than those measured by HAWC, and several new HAWC sources are not detected by VERITAS. This is likely due to a change in spectral shape, source extension, or the influence of diffuse emission in the source region.
Published: 2018
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18. 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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19. VERITAS contributions to the 36th International Cosmic Ray Conference

Author: Abeysekara, A. U., Archer, A., Benbow, W., Bird, R., Brill, A., Brose, R., Buckley, J. H., Christiansen, J. L., Chromey, A. J., Daniel, M. K., Das, S., Falcone, A., Feng, Q., Finley, J. P., Fortson, L., Furniss, A., Gent, A., Gillanders, G. H., Giuri, C., Gueta, O., Hanna, D., Hassan, T., Hervet, O., Holder, J., Hughes, G., Humensky, T. B., Kaaret, P., Kelley-Hoskins, N., Kertzman, M., Kieda, D., Krause, M., Kumar, S., Lang, M. J., Lin, T. T. Y., Lundy, M., Maier, G., Matthews, N., Moriarty, P., Mukherjee, R., Nievas-Rosillo, M., O Brien, S., Ong, R. A., Otte, A. N., Park, N., Petrashyk, A., Pfrang, K., Pohl, M., Prado, R. R., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Ribeiro, D., Richards, G. T., Roache, E., Sadeh, I., Juan Marcos Santander, Schlenstedt, S., Scott, S. S., Sembroski, G. H., Shang, R., Vassiliev, V. V., Wakely, S. P., Weinstein, A., Wells, R. M., Wilcox, P., Williams, D. A., and Williamson, T. J.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), FOS: Physical sciences, Astrophysics - High Energy Astrophysical Phenomena
Abstract: Compilation of papers presented by the VERITAS Collaboration at the 36th International Cosmic Ray Conference (ICRC), held July 24 through August 1, 2019 in Madison, Wisconsin., html page. 2019 ICRC, Madison, Wisconsin
Published: 2019

20. A Search for Pulsed Very High-Energy Gamma Rays from Thirteen Young Pulsars in Archival VERITAS Data

Author: Archer, A., Benbow, W., Bird, R., Brose, R., Buchovecky, M., Buckley, J. H., Chromey, A. J., Cui, W., Falcone, A., Feng, Q., Finley, J. P., Fortson, L., Furniss, A., Gent, A., Gueta, O., Hanna, D., 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., Krennrich, F., Kumar, S., Lang, M. J., Lin, T. T. Y., McCann, A., Moriarty, P., Mukherjee, R., O'Brien, S., Ong, R. A., Otte, A. N., Pandel, D., Park, N., Petrashyk, A., Pohl, M., Pueschel, E., Quinn, J., Ragan, K., Richards, G. T., Roache, E., Sadeh, I., Santander, M., Scott, S. S., Sembroski, G. H., Shahinyan, K., Sushch, I., Tyler, J., Wakely, S. P., Weinstein, A., Wells, R. M., Wilcox, P., Wilhelm, A., Williams, D. A., Williamson, T. J, and Zitzer, B.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astrophysics - High Energy Astrophysical Phenomena
Abstract: We conduct a search for periodic emission in the very high-energy gamma-ray band (VHE; E > 100 GeV) from a total of 13 pulsars in an archival VERITAS data set with a total exposure of over 450 hours. The set of pulsars includes many of the brightest young gamma-ray pulsars visible in the Northern Hemisphere. The data analysis resulted in non-detections of pulsed VHE gamma rays from each pulsar. Upper limits on a potential VHE gamma-ray flux are derived at the 95% confidence level above three energy thresholds using two methods. These are the first such searches for pulsed VHE emission from each of the pulsars, and the obtained limits constrain a possible flux component manifesting at VHEs as is seen for the Crab pulsar., 32 pages, 20 figures, accepted for publication in ApJ
Published: 2019

21. Measurement of the extragalactic background light spectral energy distribution with VERITAS

Author: VERITAS Collaboration, Abeysekara, A. U., Archer, A., Benbow, W., Bird, R., Brill, A., Brose, R., Buchovecky, M., Christiansen, J. L., Cui, W., Daniel, M. K., Falcone, A., Feng, Q., Fernandez-Alonso, M., Finley, J. P., Fortson, L., Furniss, A., Gent, A., Giuri, C., Gueta, O., Hanna, D., Hassan, T., Hervet, O., Holder, J., Hughes, G., Humensky, T. B., Johnson, C. A., Kaaret, P., Kertzman, M., Kieda, D., Krause, M., Krennrich, F., Kumar, S., Lang, M. J., Maier, Gernot, Moriarty, P., Mukherjee, R., Nievas-Rosillo, M., O'Brien, S., Ong, R. A., Pfrang, K., Pohl, M., Prado, R. R., Pueschel, Elisa, Ragan, K., Reynolds, P. T., Ribeiro, D., Richards, G. T., Roache, E., Rovero, A. C., Sadeh, I., Santander, M., Sembroski, G. H., Shahinyan, K., Sushch, I., Weinstein, A., Wells, R. M., Wilcox, P., Wilhelm, A., Williams, D. A., Williamson, T. J, and Zitzer, B.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Computer Science::Computation and Language (Computational Linguistics and Natural Language and Speech Processing), Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: The astrophysical journal / 2 885, 8 pages (2019)., The extragalactic background light (EBL), a diffuse photon field in the optical and infrared range, is a record of radiative processes over the Universe's history. Spectral measurements of blazars at very high energies ($>$100 GeV) enable the reconstruction of the spectral energy distribution (SED) of the EBL, as the blazar spectra are modified by redshift- and energy-dependent interactions of the gamma-ray photons with the EBL. The spectra of 14 VERITAS-detected blazars are included in a new measurement of the EBL SED that is independent of EBL SED models. The resulting SED covers an EBL wavelength range of 0.56--56 $\mu$m, and is in good agreement with lower limits obtained by assuming that the EBL is entirely due to radiation from cataloged galaxies., Published by Institute of Physics Publ., London
Published: 2019
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22. Very high-energy gamma-ray follow-up program using neutrino triggers from IceCube

Author: IceCube Collaboration, Aartsen, M. G., Abraham, K., Ackermann, M., Adams, J., Aguilar, J. A., Ahlers, M., Ahrens, M., Altmann, D., Andeen, K., Anderson, T., Ansseau, I., Anton, G., Archinger, M., Arguelles, C., Auffenberg, J., Axani, S., Bai, X., Barwick, S. W., Baum, V., Bay, R., Beatty, J. J., Becker-Tjus, J., Becker, K. -H, Benzvi, S., Berley, D., Bernardini, E., Bernhard, A., Besson, D. Z., Binder, G., Bindig, D., Bissok, M., Blaufuss, E., Blot, S., Bohm, C., Borner, M., Bos, F., Bose, D., Boser, S., Botner, O., Braun, J., Brayeur, L., Bretz, H. -P, Bron, S., Burgman, A., Carver, T., Casier, M., Cheung, E., Chirkin, D., Christov, A., Clark, K., Classen, L., Coenders, S., Collin, G. H., Conrad, J. M., Cowen, D. F., Cross, R., Day, M., Andre, J. P. A. M., Clercq, C., Del Pino Rosendo, E., Dembinski, H., Ridder, S., Desiati, P., Vries, K. D., Wasseige, G., With, M., Deyoung, T., Diaz-Velez, J. C., Di Lorenzo, V., Dujmovic, H., Dumm, J. P., Dunkman, M., Eberhardt, B., Ehrhardt, T., Eichmann, B., Eller, P., Euler, S., Evenson, P. A., Fahey, S., Fazely, A. R., Feintzeig, J., Felde, J., Filimonov, K., Finley, C., Flis, S., Fosig, C. -C, Franckowiak, A., Franke, R., Friedman, E., Fuchs, T., Gaisser, T. K., Gallagher, J., Gerhardt, L., Ghorbani, K., Giang, W., Gladstone, L., Glauch, T., Glusenkamp, T., Goldschmidt, A., Golup, G., Gonzalez, J. G., Grant, D., Griffith, Z., Haack, C., Haj Ismail, A., Hallgren, A., Halzen, F., Hansen, E., Hansmann, T., Hanson, K., Hebecker, D., Heereman, D., Helbing, K., Hellauer, R., Hickford, S., Hignight, J., Hill, G. C., Hoffman, K. D., Hoffmann, R., Holzapfel, K., Hoshina, K., Huang, F., Huber, M., Hultqvist, K., In, S., Ishihara, A., Jacobi, E., Japaridze, G. S., Jeong, M., Jero, K., Jones, B. J. P., Jurkovic, M., Kappes, A., Karg, T., Karle, A., Katz, U., Kauer, M., Keivani, A., Kelley, J. L., Kheirandish, A., Kim, M., Kintscher, T., Kiryluk, J., Kittler, T., Klein, S. R., Kohnen, G., Koirala, R., Kolanoski, H., Konietz, R., Kopke, L., Kopper, C., Kopper, S., Koskinen, D. J., Kowalski, M., Krings, K., Kroll, M., Kruckl, G., Kruger, C., Kunnen, J., Kunwar, S., Kurahashi, N., Kuwabara, T., Labare, M., Lanfranchi, J. L., Larson, M. J., Lauber, F., Lennarz, D., Lesiak-Bzdak, M., Leuermann, M., Lu, L., Lunemann, J., Madsen, J., Maggi, G., Mahn, K. B. M., Mancina, S., Mandelartz, M., Maruyama, R., Mase, K., Maunu, R., Mcnally, F., Meagher, K., Medici, M., Meier, M., Meli, A., Menne, T., Merino, G., Meures, T., Miarecki, S., Mohrmann, L., Montaruli, T., Moulai, M., Nahnhauer, R., Naumann, U., Neer, G., Niederhausen, H., Nowicki, S. C., Nygren, D. R., Obertacke Pollmann, A., Olivas, A., O Murchadha, A., Palczewski, T., Pandya, H., Pankova, D. V., Peiffer, P., Penek, O., Pepper, J. A., Perez Los Heros, C., Pieloth, D., Pinat, E., Price, P. B., Przybylski, G. T., Quinnan, M., Raab, C., Radel, L., Rameez, M., Rawlins, K., Reimann, R., Relethford, B., Relich, M., Resconi, E., Rhode, W., Richman, M., Riedel, B., Robertson, S., Rongen, M., Rott, C., Ruhe, T., Ryckbosch, D., Rysewyk, D., Sabbatini, L., Sanchez-Herrera, S. E., Sandrock, A., Sandroos, J., Sarkar, S., Satalecka, K., Schlunder, P., Schmidt, T., Schoenen, S., Schoneberg, S., Schumacher, L., Seckel, D., Seunarine, S., Soldin, D., Song, M., Spiczak, G. M., Spiering, C., Stanev, T., Stasik, A., Stettner, J., Steuer, A., Stezelberger, T., Stokstad, R. G., Stossl, A., Strom, R., Strotjohann, N. L., Sullivan, G. W., Sutherland, M., Taavola, H., Taboada, I., Tatar, J., Tenholt, F., Ter-Antonyan, S., Terliuk, A., Tevsic, G., Tilav, S., Toale, P. A., Tobin, M. N., Toscano, S., Tosi, D., Tselengidou, M., Turcati, A., Unger, E., Usner, M., Vandenbroucke, J., Eijndhoven, N., Vanheule, S., Rossem, M., Santen, J., Veenkamp, J., Vehring, M., Voge, M., Vogel, E., Vraeghe, M., Walck, C., Wallace, A., Wallraff, M., Wandkowsky, N., Weaver, Ch, Weiss, M. J., Wendt, C., Westerhoff, S., Whelan, B. J., Wickmann, S., Wiebe, K., Wiebusch, C. H., Wille, L., Williams, D. R., Wills, L., Wolf, M., Wood, T. R., Woolsey, E., Woschnagg, K., Xu, D. L., Xu, X. W., Xu, Y., Yanez, J. P., Yodh, G., Yoshida, S., Zoll, M., Magic, Collaboration, Ahnen, M. L., Ansoldi, S., Antonelli, L. A., Antoranz, P., Babic, A., Banerjee, B., Bangale, P., Barres Almeida, U., Barrio, J. A., Becerra Gonzalez, J., Bednarek, W., Berti, A., Biasuzzi, B., Biland, A., Blanch, O., Bonnefoy, S., Bonnoli, G., Borracci, F., Bretz, T., Buson, S., Carosi, A., Chatterjee, A., Clavero, R., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Da Vela, P., Dazzi, F., Angelis, A., Lotto, B., Ona Wilhelmi, E., Di Pierro, F., Doert, M., Dominguez, A., Dominis Prester, D., Dorner, D., Michele Doro, Einecke, S., Eisenacher Glawion, D., Elsaesser, D., Engelkemeier, M., Fallah Ramazani, V., Fernandez-Barral, A., Fidalgo, D., Fonseca, M. V., Font, L., Frantzen, K., Fruck, C., Galindo, D., Garcia Lopez, R. J., Garczarczyk, M., Garrido Terrats, D., Gaug, M., Giammaria, P., Godinovic, N., Gonzalez Munoz, A., Gora, D., Guberman, D., Hadasch, D., Hahn, A., Hanabata, Y., Hayashida, M., Herrera, J., Hose, J., Hrupec, D., Hughes, G., Idec, W., Kodani, K., Konno, Y., Kubo, H., Kushida, J., La Barbera, A., Lelas, D., Lindfors, E., Lombardi, S., Longo, F., Lopez, M., Lopez-Coto, R., Majumdar, P., Makariev, M., Mallot, K., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Marcote, B., Mariotti, M., Martinez, M., Mazin, D., Menzel, U., Miranda, J. M., Mirzoyan, R., Moralejo, A., Moretti, E., Nakajima, D., Neustroev, V., Niedzwiecki, A., Nievas Rosillo, M., Nilsson, K., Nishijima, K., Noda, K., Nogues, L., Overkemping, A., Paiano, S., Palacio, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Paredes-Fortuny, X., Pedaletti, G., Peresano, M., Perri, L., Persic, M., Poutanen, J., Prada Moroni, P. G., Prandini, E., Puljak, I., Reichardt, I., Ribo, M., Rico, J., Rodriguez Garcia, J., Saito, T., Schroeder, S., Schultz, C., Schweizer, T., Shore, S. N., Sillanpaa, A., Sitarek, J., Snidaric, I., Sobczynska, D., Stamerra, A., Steinbring, T., Strzys, M., Suric, T., Takalo, L., Tavecchio, F., Temnikov, P., Terzic, T., Tescaro, D., Teshima, M., Thaele, J., Torres, D. F., Toyama, T., Treves, A., Vanzo, G., Verguilov, V., Vovk, I., Ward, J. E., Will, M., Wu, M. H., Zanin, R., Veritas, Collaboration, Abeysekara, A. U., Archambault, S., Archer, A., Benbow, W., Bird, R., Bourbeau, E., Buchovecky, M., Bugaev, V., Byrum, K., Cardenzana, J. V., Cerruti, M., Ciupik, L., Connolly, M. P., Cui, W., Dickinson, H. J., Dumm, J., Eisch, J. D., Errando, M., Falcone, A., Feng, Q., Finley, J. P., Fleischhack, H., Flinders, A., Fortson, L., Furniss, A., Gillanders, G. H., Griffin, S., Grube, J., Hutten, M., Haakansson, N., Hervet, O., Holder, J., Humensky, T. B., Johnson, C. A., Kaaret, P., Kar, P., Kelley-Hoskins, N., Kertzman, M., Kieda, D., Krause, M., Krennrich, F., Kumar, S., Lang, M. J., Maier, G., Mcarthur, S., Mccann, A., Moriarty, P., Mukherjee, R., Nguyen, T., Nieto, D., O Brien, S., Ong, R. A., Otte, A. N., Park, N., Pohl, M., Popkow, A., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Richards, G. T., Roache, E., Rulten, C., Sadeh, I., Santander, M., Sembroski, G. H., Shahinyan, K., Staszak, D., Telezhinsky, I., Tucci, J. V., Tyler, J., Wakely, S. P., Weinstein, A., Wilcox, P., Wilhelm, A., Williams, D. A., Zitzer, B., Vriendenkring VUB, Physics, Elementary Particle Physics, Universitat de Barcelona, Aartsen, M. G., Abraham, K., Ackermann, M., Adams, J., Aguilar, J. A., Ahlers, M., Ahrens, M., Altmann, D., Andeen, K., Anderson, T., Ansseau, I., Anton, G., Archinger, M., Argï¿½elles, C., Auffenberg, J., Axani, S., Bai, X., Barwick, S. W., Baum, V., Bay, R., Beatty, J. J., Becker Tjus, J., Becker, K. -H., Benzvi, S., Berley, D., Bernardini, E., Bernhard, A., Besson, D. Z., Binder, G., Bindig, D., Bissok, M., Blaufuss, E., Blot, S., Bohm, C., Bï¿½rner, M., Bos, F., Bose, D., Bï¿½ser, S., Botner, O., Braun, J., Brayeur, L., Bretz, H. -P., Bron, S., Burgman, A., Carver, T., Casier, M., Cheung, E., Chirkin, D., Christov, A., Clark, K., Classen, L., Coenders, S., Collin, G. H., Conrad, J. M., Cowen, D. F., Cross, R., Day, M., De Andrï¿½, J. P. A. M., De Clercq, C., Del Pino Rosendo, E., Dembinski, H., De Ridder, S., Desiati, P., De Vries, K. D., De Wasseige, G., De With, M., Deyoung, T., Dï¿½az-Vï¿½lez, J. C., Di Lorenzo, V., Dujmovic, H., Dumm, J. P., Dunkman, M., Eberhardt, B., Ehrhardt, T., Eichmann, B., Eller, P., Euler, S., Evenson, P. A., Fahey, S., Fazely, A. R., Feintzeig, J., Felde, J., Filimonov, K., Finley, C., Flis, S., Fï¿½sig, C. -C., Franckowiak, A., Franke, R., Friedman, E., Fuchs, T., Gaisser, T. K., Gallagher, J., Gerhardt, L., Ghorbani, K., Giang, W., Gladstone, L., Glauch, T., Glï¿½senkamp, T., Goldschmidt, A., Golup, G., Gonzalez, J. G., Grant, D., Griffith, Z., Haack, C., Haj Ismail, A., Hallgren, A., Halzen, F., Hansen, E., Hansmann, T., Hanson, K., Hebecker, D., Heereman, D., Helbing, K., Hellauer, R., Hickford, S., Hignight, J., Hill, G. C., Hoffman, K. D., Hoffmann, R., Holzapfel, K., Hoshina, K., Huang, F., Huber, M., Hultqvist, K., In, S., Ishihara, A., Jacobi, E., Japaridze, G. S., Jeong, M., Jero, K., Jones, B. J. P., Jurkovic, M., Kappes, A., Karg, T., Karle, A., Katz, U., Kauer, M., Keivani, A., Kelley, J. L., Kheirandish, A., Kim, M., Kintscher, T., Kiryluk, J., Kittler, T., Klein, S. R., Kohnen, G., Koirala, R., Kolanoski, H., Konietz, R., Kï¿½pke, L., Kopper, C., Kopper, S., Koskinen, D. J., Kowalski, M., Krings, K., Kroll, M., Krï¿½ckl, G., Krï¿½ger, C., Kunnen, J., Kunwar, S., Kurahashi, N., Kuwabara, T., Labare, M., Lanfranchi, J. L., Larson, M. J., Lauber, F., Lennarz, D., Lesiak-Bzdak, M., Leuermann, M., Lu, L., Lï¿½nemann, J., Madsen, J., Maggi, G., Mahn, K. B. M., Mancina, S., Mandelartz, M., Maruyama, R., Mase, K., Maunu, R., Mcnally, F., Meagher, K., Medici, M., Meier, M., Meli, A., Menne, T., Merino, G., Meures, T., Miarecki, S., Mohrmann, L., Montaruli, T., Moulai, M., Nahnhauer, R., Naumann, U., Neer, G., Niederhausen, H., Nowicki, S. C., Nygren, D. R., Obertacke Pollmann, A., Olivas, A., O'Murchadha, A., Palczewski, T., Pandya, H., Pankova, D. V., Peiffer, P., Penek, O., Pepper, J. A., Pï¿½rez De Los Heros, C., Pieloth, D., Pinat, E., Price, P. B., Przybylski, G. T., Quinnan, M., Raab, C., Rï¿½del, L., Rameez, M., Rawlins, K., Reimann, R., Relethford, B., Relich, M., Resconi, E., Rhode, W., Richman, M., Riedel, B., Robertson, S., Rongen, M., Rott, C., Ruhe, T., Ryckbosch, D., Rysewyk, D., Sabbatini, L., Sanchez Herrera, S. E., Sandrock, A., Sandroos, J., Sarkar, S., Satalecka, K., Schlunder, P., Schmidt, T., Schoenen, S., Schï¿½neberg, S., Schumacher, L., Seckel, D., Seunarine, S., Soldin, D., Song, M., Spiczak, G. M., Spiering, C., Stanev, T., Stasik, A., Stettner, J., Steuer, A., Stezelberger, T., Stokstad, R. G., Stï¿½ï¿½l, A., Strï¿½m, R., Strotjohann, N. L., Sullivan, G. W., Sutherland, M., Taavola, H., Taboada, I., Tatar, J., Tenholt, F., Ter-Antonyan, S., Terliuk, A., Tesic, G., Tilav, S., Toale, P. A., Tobin, M. N., Toscano, S., Tosi, D., Tselengidou, M., Turcati, A., Unger, E., Usner, M., Vandenbroucke, J., Van Eijndhoven, N., Vanheule, S., Van Rossem, M., Van Santen, J., Veenkamp, J., Vehring, M., Voge, M., Vogel, E., Vraeghe, M., Walck, C., Wallace, A., Wallraff, M., Wandkowsky, N., Weaver, Ch., Weiss, M. J., Wendt, C., Westerhoff, S., Whelan, B. J., Wickmann, S., Wiebe, K., Wiebusch, C. H., Wille, L., Williams, D. R., Wills, L., Wolf, M., Wood, T. R., Woolsey, E., Woschnagg, K., Xu, D. L., Xu, X. W., Xu, Y., Yanez, J. P., Yodh, G., Yoshida, S., Zoll, M., Ahnen, M. L., Ansoldi, S., Antonelli, L. A., Antoranz, P., Babic, A., Banerjee, B., Bangale, P., Barres De Almeida, U., Barrio, J. A., Becerra Gonzï¿½lez, J., Bednarek, W., Berti, A., Biasuzzi, B., Biland, A., Blanch, O., Bonnefoy, S., Bonnoli, G., Borracci, F., Bretz, T., Buson, S., Carosi, A., Chatterjee, A., Clavero, R., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., De Ona Wilhelmi, E., Di Pierro, F., Doert, M., Domï¿½nguez, A., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Eisenacher Glawion, D., Elsaesser, D., Engelkemeier, M., Ramazani Fallah, V., Fernï¿½ndez-Barral, A., Fidalgo, D., Fonseca, M. V., Font, L., Frantzen, K., Fruck, C., Galindo, D., Garcï¿½a Lopez, R. J., Garczarczyk, M., Garrido Terrats, D., Gaug, M., Giammaria, P., Godinovic, N., Gonzï¿½lez Munoz, A., Gora, D., Guberman, D., Hadasch, D., Hahn, A., Hanabata, Y., Hayashida, M., Herrera, J., Hose, J., Hrupec, D., Hughes, G., Idec, W., Kodani, K., Konno, Y., Kubo, H., Kushida, J., La Barbera, A., Lelas, D., Lindfors, E., Lombardi, S., Longo, F., Lopez, M., Lopez-Coto, R., Majumdar, P., Makariev, M., Mallot, K., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Marcote, B., Mariotti, M., Martï¿½nez, M., Mazin, D., Menzel, U., Miranda, J. M., Mirzoyan, R., Moralejo, A., Moretti, E., Nakajima, D., Neustroev, V., Niedzwiecki, A., Nievas Rosillo, M., Nilsson, K., Nishijima, K., Noda, K., Noguï¿½s, L., Overkemping, A., Paiano, S., Palacio, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Paredes-Fortuny, X., Pedaletti, G., Peresano, M., Perri, L., Persic, M., Poutanen, J., Prada Moroni, P. G., Prandini, E., Puljak, I., Reichardt, I., Ribo, M., Rico, J., Rodriguez Garcia, J., Saito, T., Schroeder, S., Schultz, C., Schweizer, T., Sillanpï¿½ï¿½, A., Sitarek, J., Snidaric, I., Sobczynska, D., Stamerra, A., Steinbring, T., Strzys, M., Suric, T., Takalo, L., Tavecchio, F., Temnikov, P., Terzic, T., Tescaro, D., Teshima, M., Thaele, J., Torres, D. F., Toyama, T., Treves, A., Vanzo, G., Verguilov, V., Vovk, I., Ward, J. E., Will, M., Wu, M. H., Zanin, R., Abeysekara, A. U., Archambault, S., Archer, A., Benbow, W., Bird, R., Bourbeau, E., Buchovecky, M., Bugaev, V., Byrum, K., Cardenzana, J. V., Cerruti, M., Ciupik, L., Connolly, M. P., Cui, W., Dickinson, H. J., Dumm, J., Eisch, J. D., Errando, M., Falcone, A., Feng, Q., Finley, J. P., Fleischhack, H., Flinders, A., Fortson, L., Furniss, A., Gillanders, G. H., Griffin, S., Grube, J., Hï¿½tten, M., Hakansson, N., Hervet, O., Holder, J., Humensky, T. B., Johnson, C. A., Kaaret, P., Kar, P., Kelley-Hoskins, N., Kertzman, M., Kieda, D., Krause, M., Krennrich, F., Kumar, S., Lang, M. J., Maier, G., Mcarthur, S., Mccann, A., Moriarty, P., Mukherjee, R., Nguyen, T., Nieto, D., O'Brien, S., Ong, R. A., Otte, A. N., Park, N., Pohl, M., Popkow, A., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Richards, G. T., Roache, E., Rulten, C., Sadeh, I., Santander, M., Sembroski, G. H., Shahinyan, K., Staszak, D., Telezhinsky, I., Tucci, J. V., Tyler, J., Wakely, S. P., Weinstein, A., Wilcox, P., Wilhelm, A., Williams, D. A., Zitzer, B., Massachusetts Institute of Technology. Department of Physics, Arguelles Delgado, Carlos A, Axani, Spencer Nicholas, Collin G. H., Conrad, Janet Marie, Jones, Benjamin James Poyner, and Moulai, Marjon H.
Subjects: High energy, Particle physics, Physics - Instrumentation and Detectors, Gamma telescope, media_common.quotation_subject, Astrophysics::High Energy Astrophysical Phenomena, Gamma telescopes, FOS: Physical sciences, 01 natural sciences, Neutrino detectors, Instrumentation, Mathematical Physics, Online analysis, High Energy Physics - Experiment, Neutrino detector, High Energy Physics - Experiment (hep-ex), Raigs gamma, 0103 physical sciences, MAGIC (telescope), ddc:610, Neutrins, Neutrinos, Blazar, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, media_common, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, 010308 nuclear & particles physics, Gamma rays, Gamma ray, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Instrumentation and Detectors (physics.ins-det), Sky, Física nuclear, Neutrino, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics, neutrino detectors, gamma telescopes
Abstract: Journal of Instrumentation 11(11), P11009(2016). doi:10.1088/1748-0221/11/11/P11009, We describe and report the status of a neutrino-triggered program in IceCube that generates real-time alerts for gamma-ray follow-up observations by atmospheric-Cherenkov telescopes (MAGIC and VERITAS). While IceCube is capable of monitoring the whole sky continuously, high-energy gamma-ray telescopes have restricted fields of view and in general are unlikely to be observing a potential neutrino-flaring source at the time such neutrinos are recorded. The use of neutrino-triggered alerts thus aims at increasing the availability of simultaneous multi-messenger data during potential neutrino flaring activity, which can increase the discovery potential and constrain the phenomenological interpretation of the high-energy emission of selected source classes (e.g. blazars). The requirements of a fast and stable online analysis of potential neutrino signals and its operation are presented, along with first results of the program operating between 14 March 2012 and 31 December 2015., Published by Inst. of Physics, London
Published: 2017
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23. VERITAS and Fermi-LAT observations of new HAWC sources

Author: VERITAS Collaboration, Abeysekara, A. U., Archer, A., Benbow, W., Bird, R., Brose, R., Buchovecky, M., Buckley, J. H., Bugaev, V., Chromey, A. J., Connolly, M. P., Cui, W., Daniel, M. K., Falcone, A., Feng, Q., Finley, J. P., Fortson, L., Furniss, A., Hutten, M., Hanna, D., Hervet, O., Holder, J., Hughes, G., Humensky, T. B., Johnson, C. A., Kaaret, P., Kar, P., Kertzman, M., Kieda, D., Krause, M., Krennrich, F., Kumar, S., Lang, M. J., Lin, T. T. Y., McArthur, S., 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., Reynolds, P. T., Richards, G. T., Roache, E., Rulten, C., Sadeh, I., Santander, M., Sembroski, G. H., Shahinyan, K., Sushch, I., Tyler, J., Wakely, S. P., Weinstein, A., Wells, R. M., Wilcox, P., Wilhelm, A., Williams, D. A., Williamson, T. J., Zitzer, B., Collaboration, Fermi-LAT, Abdollahi, S., Ajello, M., Baldini, L., Barbiellini, G., Bastieri, D., Bellazzini, R., Berenji, B., Bissaldi, E., Blandford, R. D., Bonino, R., Bottacini, E., Brandt, T. J., Bruel, P., Buehler, R., Cameron, R. A., Caputo, R., Caraveo, P. A., Castro, D., Cavazzuti, E., Charles, E., Chiaro, G., Ciprini, S., Cohen-Tanugi, J., Costantin, D., Cutini, S., D'Ammando, F., de Palma, F., Di Lalla, N., Di Mauro, M., Di Venere, L., Dominguez, A., Favuzzi, C., Fegan, S. J., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Green, D., Grenier, I. A., Guillemot, L., Guiriec, S., Hays, E., Hewitt, J. W., Horan, D., Johannesson, G., Kensei, S., Kuss, M., Larsson, S., Latronico, L., Lemoine-Goumard, M., Li, J., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Magill, J. D., Maldera, S., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Negro, M., Nuss, E., Ojha, R., Omodei, N., Orienti, M., Orlando, E., Palatiello, M., Paliya, V. S., Paneque, D., Perkins, J. S., Persic, M., Pesce-Rollins, M., Petrosian, V., Piron, F., Porter, T. A., Principe, G., Raino, S., Rando, R., Rani, B., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reposeur, T., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Suson, D. J., Tajima, H., Thayer, J. B., Thompson, D. J., Torres, D. F., Tosti, G., Troja, E., Valverde, J., Vianello, G., Vogel, M., Wood, K., Yassine, M., Collaboration, HAWC, Alfaro, R., Alvarez, C., Alvarez, J. D., Arceo, R., Arteaga-Velazquez, J. C., Rojas, D. Avila, Solares, H. A. Ayala, Becerril, A., Belmont-Moreno, E., BenZvi, S. Y., Bernal, A., Braun, J., Brisbois, C., Caballero-Mora, K. S., Capistran, T., Carraminana, A., Casanova, S., Castillo, M., Cotti, U., Cotzomi, J., de Leon, S. Coutino, De Leon, C., De la Fuente, E., Dichiara, S., Dingus, B. L., DuVernois, M. A., Diaz-Velez, J. C., Engel, K., Enriquez-Rivera, O., Fiorino, D. W., Fleischhack, H., Fraija, N., Garcia-Gonzalez, J. A., Garfias, F., Munoz, A. Gonzalez, Gonzalez, M. M., Goodman, J. A., Hampel-Arias, Z., Harding, J. P., Hernandez, S., Hernandez-Almada, A., Hona, B., Hueyotl-Zahuantitla, F., Hui, C. M., Huntemeyer, P., Iriarte, A., Jardin-Blicq, A., Joshi, V., Kaufmann, S., Lara, A., Lauer, R. J., Lee, W. H., Lennarz, D., Vargas, H. Leon, Linnemann, J. T., Longinotti, A. L., Luis-Raya, G., Luna-Garcia, R., Lopez-Coto, R., Malone, K., Marinelli, S. S., Martinez, O., Martinez-Castellanos, I., Martinez-Castro, J., Martinez-Huerta, H., Matthews, J. A., Miranda-Romagnoli, P., Moreno, E., Mostafa, M., Nayerhoda, A., Nellen, L., Newbold, M., Nisa, M. U., Noriega-Papaqui, R., Pelayo, R., Pretz, J., Perez-Perez, E. G., Ren, Z., Rho, C. D., Riviere, C., Rosa-Gonzalez, D., Rosenberg, M., Ruiz-Velasco, E., Salazar, H., Greus, F. Salesa, Sandoval, A., Schneider, M., Arroyo, M. Seglar, Sinnis, G., Smith, A. J., Springer, R. W., Surajbali, P., Taboada, I., Tibolla, O., Tollefson, K., Torres, I., Ukwatta, T. N., Villasenor, L., Weisgarber, T., Westerhoff, S., Wisher, I. G., Wood, J., Yapici, T., Yodh, G., Zepeda, A., and Zhou, H.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics - High Energy Astrophysical Phenomena
Abstract: The HAWC (High Altitude Water Cherenkov) collaboration recently published their 2HWC catalog, listing 39 very high energy (VHE; >100~GeV) gamma-ray sources based on 507 days of observation. Among these, there are nineteen sources that are not associated with previously known TeV sources. We have studied fourteen of these sources without known counterparts with VERITAS and Fermi-LAT. VERITAS detected weak gamma-ray emission in the 1~TeV-30~TeV band in the region of DA 495, a pulsar wind nebula coinciding with 2HWC J1953+294, confirming the discovery of the source by HAWC. We did not find any counterpart for the selected fourteen new HAWC sources from our analysis of Fermi-LAT data for energies higher than 10 GeV. During the search, we detected GeV gamma-ray emission coincident with a known TeV pulsar wind nebula, SNR G54.1+0.3 (VER J1930+188), and a 2HWC source, 2HWC J1930+188. The fluxes for isolated, steady sources in the 2HWC catalog are generally in good agreement with those measured by imaging atmospheric Cherenkov telescopes. However, the VERITAS fluxes for SNR G54.1+0.3, DA 495, and TeV J2032+4130 are lower than those measured by HAWC and several new HAWC sources are not detected by VERITAS. This is likely due to a change in spectral shape, source extension, or the influence of diffuse emission in the source region., Accepted for publication in the ApJ, Corresponding author: Nahee Park (VERITAS Collaboration), John W. Hewitt (Fermi-LAT Collaboration), Ignacio Taboada (HAWC Collaboration), 30 pages, 12 figures
Published: 2018

24. Veritas observations of the bl lac object txs 0506+056

Author: Abeysekara, A. U., Archer, A., Benbow, W., Bird, R., Brill, A., Brose, R., Buckley, J. H., Christiansen, J. L., Chromey, A. J., Daniel, M. K., Falcone, A., Feng, Q., Finley, J. P., Fortson, L., Furniss, A., Gillanders, G. H., Gueta, O., Hanna, D., Hervet, O., Holder, J., Hughes, G., Humensky, T. B., Johnson, C. A., Kaaret, P., Kar, P., Kelley-Hoskins, N., Kertzman, M., Kieda, D., Krause, M., Krennrich, F., Lang, M. J., 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., Reynolds, P. T., Richards, G. T., Roache, E., Rulten, C., Sadeh, I., Santander, M., Scott, S. S., Sembroski, G. H., Shahinyan, K., Tyler, J., Wakely, S. P., Weinstein, A., Wells, R. M., Wilcox, P., Wilhelm, A., Williams, D. A., Williamson, T. J, Zitzer, B., and Kaur, A.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, telescope, 01 natural sciences, IceCube Neutrino Observatory, blazar, quasars: general, 0103 physical sciences, gamma rays: galaxies, ddc:530, 010306 general physics, Blazar, 010303 astronomy & astrophysics, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Spectral index, Institut für Physik und Astronomie, neutrinos, Astronomy and Astrophysics, i, radiation, Crab Nebula, mission, 13. Climate action, Space and Planetary Science, astroparticle physics, bl lacertae objects: individual (txs 0506+056, ver j0509+057), active galactic nuclei, ddc:520, High Energy Physics::Experiment, Neutrino, Astrophysics - High Energy Astrophysical Phenomena, Energy (signal processing), Fermi Gamma-ray Space Telescope, BL Lac object
Abstract: On 2017 September 22, the IceCube Neutrino Observatory reported the detection of the high-energy neutrino event IC 170922A, of potential astrophysical origin. It was soon determined that the neutrino direction was consistent with the location of the gamma-ray blazar TXS 0506+056. (3FGL J0509.4+ 0541), which was in an elevated gamma-ray emission state as measured by the Fermi satellite. Very Energetic Radiation Imaging Telescope Array System (VERITAS) observations of the neutrino/blazar region started on 2017 September 23 in response to the neutrino alert and continued through 2018 February 6. While no significant very-high-energy (VHE; E > 100 GeV) emission was observed from the blazar by VERITAS in the two-week period immediately following the IceCube alert, TXS 0506+ 056 was detected by VERITAS with a significance of 5.8 standard deviations (sigma) in the full 35 hr data set. The average photon flux of the source during this period was (8.9 +/- 1.6). x. 10(-12) cm(-2) s(-1), or 1.6% of the Crab Nebula flux, above an energy threshold of 110 GeV, with a soft spectral index of 4.8. +/-. 1.3.
Published: 2018
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25. Multiwavelength Observations of the Blazar BL Lacertae

Author: Abeysekara, A. U., Benbow, W., Bird, R., Brantseg, T., Brose, R., Buchovecky, M., Buckley, J. H., Bugaev, V., Connolly, M. P., Cui, W., Daniel, M. K., Falcone, A., Feng, Q., Finley, J. P., Fortson, L., Furniss, A., Gillanders, G. H., Gunawardhana, I., Hütten, M., Hanna, D., Hervet, O., Holder, J., Hughes, G., Humensky, T. B., Johnson, C. A., Kaaret, P., Kar, P., Kertzman, M., Krennrich, F., Lang, M. J., Lin, T. T.Y., McArthur, S., Moriarty, P., Mukherjee, R., O'Brien, S., Ong, R. A., Otte, A. N., Park, N., Petrashyk, A., Pohl, Martin, Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Richards, G. T., Roache, E., Rulten, C., Sadeh, I., Santander, M., Sembroski, G. H., Shahinyan, K., Wakely, S. P., Weinstein, A., Wells, R. M., Wilcox, P., Williams, D. A., Zitzer, B., Jorstad, S. G., Marscher, A. P., Lister, M. L., Kovalev, Y. Y., Pushkarev, A. B., Savolainen, T., Agudo, I., Molina, S. N., Gómez, J. L., Larionov, V. M., Borman, G. A., Mokrushina, A. A., Tornikoski, M., Lahteenmaki, A., Chamani, Wara, Enestam, S., Kiehlmann, S., Hovatta, T., Smith, P. S., Pontrelli, P., University of Utah, Harvard University, University of California Los Angeles, Iowa State University, University of Potsdam, Washington University St. Louis, National University of Ireland, Galway, Purdue University, Pennsylvania State University, McGill University, University of Minnesota Twin Cities, California State University, East Bay, German Electron Synchrotron, University of California Santa Cruz, University of Delaware, Columbia University, University of Iowa, DePauw University, University College Dublin, Georgia Institute of Technology, University of Chicago, Cork Institute of Technology, Boston University, RAS - P.N. Lebedev Physics Institute, Metsähovi Radio Observatory, CSIC, St. Petersburg State University, Crimean Astrophysical Observatory, Department of Electronics and Nanoengineering, California Institute of Technology, University of Turku, University of Arizona, Aalto-yliopisto, and Aalto University
Subjects: Astrophysics::High Energy Astrophysical Phenomena, active [galaxies], Astrophysics::Cosmology and Extragalactic Astrophysics, individual (BL Lacertae = VER J2202+422) [BL Lacertae objects]
Abstract: Combined with measurements made by very-long-baseline interferometry, the observations of fast TeV gamma-ray flares probe the structure and emission mechanism of blazar jets. However, only a handful of such flares have been detected to date, and only within the last few years have these flares been observed from lower-frequency-peaked BL Lac objects and flat-spectrum radio quasars. We report on a fast TeV gamma-ray flare from the blazar BL Lacertae observed by the Very Energetic Radiation Imaging Telescope Array System (VERITAS). with a rise time of ∼2.3 hr and a decay time of ∼36 min. The peak flux above 200 GeV is (4.2 ± 0.6) ×10-6 photon m-2 s-1 measured with a 4-minute-binned light curve, corresponding to ∼180% of the flux that is observed from the Crab Nebula above the same energy threshold. Variability contemporaneous with the TeV gamma-ray flare was observed in GeV gamma-ray, X-ray, and optical flux, as well as in optical and radio polarization. Additionally, a possible moving emission feature with superluminal apparent velocity was identified in Very Long Baseline Array observations at 43 GHz, potentially passing the radio core of the jet around the time of the gamma-ray flare. We discuss the constraints on the size, Lorentz factor, and location of the emitting region of the flare, and the interpretations with several theoretical models that invoke relativistic plasma passing stationary shocks.
Published: 2018

26. Multiwavelength Observations of the Blazar BL Lacertae

Author: Abeysekara, A. U., Benbow, Wystan, Bird, Ralph, Brantseg, T., Brose, Robert, Buchovecky, M., Buckley, J. H., Bugaev, V., Connolly, M. P., Cui, Wei, Daniel, M. K., Falcone, A., Feng, Qi, Finley, John P., Fortson, L., Furniss, Amy, Gillanders, Gerard H., Gunawardhana, Isuru, Huetten, M., Hanna, David, Hervet, O., Holder, J., Hughes, G., Humensky, T. B., Johnson, Caitlin A., Kaaret, Philip, Kar, P., Kertzman, M., Krennrich, F., Lang, M. J., Lin, T. T. Y., McArthur, S., Moriarty, P., Mukherjee, Reshmi, Ong, R. A., Otte, Adam Nepomuk, Park, N., Petrashyk, A., Pohl, Martin Karl Wilhelm, Pueschel, Elisa, Quinn, J., Ragan, K., Reynolds, P. T., Richards, Gregory T., Roache, E., Rulten, C., Sadeh, I., Santander, M., Sembroski, G. H., Shahinyan, Karlen, Wakely, S. P., Weinstein, A., Wells, R. M., Wilcox, P., Williams, D. A., Zitzer, B., Jorstad, Svetlana G., Marscher, Alan P., Lister, Matthew L., Kovalev, Yuri Y., Pushkarev, A. B., Savolainen, Tuomas, Agudo, I., Molina, S. N., Gomez, J. L., Larionov, Valeri M., Borman, G. A., Mokrushina, A. A., Tornikoski, Merja, Lahteenmaki, A., Chamani, W., Enestam, S., Kiehlmann, S., Hovatta, Talvikki, Smith, P. S., and Pontrelli, P.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Institut für Physik und Astronomie, ddc:530, Astrophysics::Cosmology and Extragalactic Astrophysics
Abstract: Combined with measurements made by very-long-baseline interferometry, the observations of fast TeV gamma-ray flares probe the structure and emission mechanism of blazar jets. However, only a handful of such flares have been detected to date, and only within the last few years have these flares been observed from lower-frequency-peaked BL. Lac objects and flat-spectrum radio quasars. We report on a fast TeV gamma-ray flare from the blazar BL. Lacertae observed by the Very Energetic Radiation Imaging Telescope Array System (VERITAS). with a rise time of similar to 2.3 hr and a decay time of similar to 36 min. The peak flux above 200 GeV is (4.2 +/- 0.6) x 10(-6) photon m(-2) s(-1) measured with a 4-minute-binned light curve, corresponding to similar to 180% of the flux that is observed from the Crab Nebula above the same energy threshold. Variability contemporaneous with the TeV gamma-ray flare was observed in GeV gamma-ray, X-ray, and optical flux, as well as in optical and radio polarization. Additionally, a possible moving emission feature with superluminal apparent velocity was identified in Very Long Baseline Array observations at 43 GHz, potentially passing the radio core of the jet around the time of the gamma-ray flare. We discuss the constraints on the size, Lorentz factor, and location of the emitting region of the flare, and the interpretations with several theoretical models that invoke relativistic plasma passing stationary shocks.
Published: 2018

27. A Very High Energy $��$-Ray Survey towards the Cygnus Region of the Galaxy

Author: The VERITAS Collaboration, Abeysekara, A. U., Archer, A., Aune, T., Benbow, W., Bird, R., Brose, R., Buchovecky, M., Bugaev, V., Cui, W., Daniel, M. K., Falcone, A., Feng, Q., Finley, J. P., Fleischhack, H., Flinders, A., Fortson, L., Furniss, A., Gotthelf, E. V., Grube, J., Hanna, D., Hervet, O., Holder, J., Huang, K., Hughes, G., Humensky, T. B., H��tten, M., Johnson, C. A., Kaaret, P., Kar, P., Kelley-Hoskins, N., Kertzman, M., Kieda, D., Krause, M., Kumar, S., Lang, M. J., Lin, T. T. Y., Maier, G., McArthur, S., Moriarty, P., Mukherjee, R., O'Brien, S., Ong, R. A., Otte, A. N., Pandel, D., Park, N., Petrashyk, A., Pohl, M., Popkow, A., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Richards, G. T., Roache, E., Rousselle, J., Rulten, C., Sadeh, I., Santander, M., Sembroski, G. H., Shahinyan, K., Tyler, J., Vassiliev, V. V., Wakely, S. P., Ward, J. E., Weinstein, A., Wells, R. M., Wilcox, P., Wilhelm, A., Williams, D. A., and Zitzer, B.
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: We present results from deep observations towards the Cygnus region using 300 hours of very-high-energy (VHE) $��$-ray data taken with the VERITAS Cherenkov telescope array and over seven years of high-energy $��$-ray data taken with the Fermi satellite at an energy above 1 GeV. As the brightest region of diffuse $��$-ray emission in the northern sky, the Cygnus region provides a promising area to probe the origins of cosmic rays. We report the identification of a potential Fermi-LAT counterpart to VER J2031+415 (TeV J2032+4130), and resolve the extended VHE source VER J2019+368 into two source candidates (VER J2018+367* and VER J2020+368*) and characterize their energy spectra. The Fermi-LAT morphology of 3FGL 2021.0+4031e (the Gamma-Cygni supernova remnant) was examined and a region of enhanced emission coincident with VER J2019+407 was identified and jointly fit with the VERITAS data. By modeling 3FGL J2015.6+3709 as two sources, one located at the location of the pulsar wind nebula CTB 87 and one at the quasar QSO J2015+371, a continuous spectrum from 1 GeV to 10 TeV was extracted for VER J2016+371 (CTB 87). An additional 71 locations coincident with Fermi-LAT sources and other potential objects of interest were tested for VHE $��$-ray emission, with no emission detected and upper limits on the differential flux placed at an average of 2.3% of the Crab Nebula ux. We interpret these observations in a multiwavelength context and present the most detailed $��$-ray view of the region to date., 49 Pages, 22 Figures, 13 Tables, Accepted to ApJ
Published: 2018
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28. A Very High Energy γ -Ray Survey toward the Cygnus Region of the Galaxy

Author: Abeysekara, A. U., Archer, A., Aune, T., Benbow, W., Bird, R., Brose, R., Buchovecky, M., Bugaev, V., Cui, W., Daniel, M. K., Falcone, A., Feng, Q., Finley, J. P., Fleischhack, H., Flinders, A., Fortson, L., Furniss, A., Gotthelf, E. V., Grube, J., Hanna, D., Hervet, O., Holder, J., Huang, K., Hughes, G., Humensky, T. B., Huetten, Moritz, Johnson, C. A., Kaaret, P., Kar, P., Kelley-Hoskins, N., Kertzman, M., Kieda, D., Krause, M., Kumar, S., Lang, M. J., Lin, T. T. Y., Maier, Gernot, McArthur, S., Moriarty, P., Mukherjee, R., O’Brien, S., Ong, R. A., Otte, A. N., Pandel, D., Park, N., Petrashyk, A., Pohl, M., Popkow, A., Pueschel, Elisa, Quinn, J., Ragan, K., Reynolds, P. T., Richards, G. T., Roache, E., Rousselle, J., Rulten, C., Sadeh, I., Santander, M., Sembroski, G. H., Shahinyan, K., Tyler, J., Vassiliev, V. V., Wakely, S. P., Ward, J. E., Weinstein, A., Wells, R. M., Wilcox, P., Wilhelm, Alina, Williams, D. A., and Zitzer, B.
Abstract: The astrophysical journal / 1 861(2), 134 (2018). doi:10.3847/1538-4357/aac4a2, We present results from deep observations toward the Cygnus region using 300 hr of very high energy (VHE) γ-ray data taken with the VERITAS Cerenkov telescope array and over 7 yr of high-energy γ-ray data taken with the Fermi satellite at an energy above 1 GeV. As the brightest region of diffuse γ-ray emission in the northern sky, the Cygnus region provides a promising area to probe the origins of cosmic rays. We report the identification of a potential Fermi-LAT counterpart to VER J2031+415 (TeV J2032+4130) and resolve the extended VHE source VER J2019+368 into two source candidates (VER J2018+367* and VER J2020+368*) and characterize their energy spectra. The Fermi-LAT morphology of 3FGL J2021.0+4031e (the Gamma Cygni supernova remnant) was examined, and a region of enhanced emission coincident with VER J2019+407 was identified and jointly fit with the VERITAS data. By modeling 3FGL J2015.6+3709 as two sources, one located at the location of the pulsar wind nebula CTB 87 and one at the quasar QSO J2015+371, a continuous spectrum from 1 GeV to 10 TeV was extracted for VER J2016+371 (CTB 87). An additional 71 locations coincident with Fermi-LAT sources and other potential objects of interest were tested for VHE γ-ray emission, with no emission detected and upper limits on the differential flux placed at an average of 2.3% of the Crab Nebula flux. We interpret these observations in a multiwavelength context and present the most detailed γ-ray view of the region to date., Published by Univ.11032, Chicago, Ill. [u.a.]
Published: 2018
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29. HESS J1943+213: An Extreme Blazar Shining through the Galactic Plane

Author: Archer, A., Benbow, W., Bird, R., Brose, R., Buchovecky, M., Bugaev, V., Cui, W., Daniel, M. K., Falcone, A., Feng, Q., Finley, J. P., Flinders, A., Fortson, L., Furniss, A., Gillanders, G. H., Hütten, M., Hanna, D., Hervet, O., Holder, J., Hughes, G., Humensky, T. B., Johnson, C. A., Kaaret, P., Kar, P., Kelley-Hoskins, N., Kieda, D., Krause, M., Krennrich, F., Kumar, S., Lang, M. J., Lin, T. T. Y., McArthur, S., Moriarty, P., Mukherjee, R., Nieto, D., O’Brien, S., Ong, R. A., Otte, A. N., Park, N., Petrashyk, A., Pohl, M., Popkow, A., Pueschel, Elisa, Quinn, J., Ragan, K., Reynolds, P. T., Richards, G. T., Roache, E., Rulten, C., Sadeh, I., Sembroski, G. H., Shahinyan, K., Tyler, J., Wakely, S. P., Weiner, O. M., Weinstein, A., Wells, R. M., Wilcox, P., Wilhelm, A., Williams, D. A., Brisken, W. F., and Pontrelli, P.
Abstract: The astrophysical journal / 1 862(1), 41 (2018). doi:10.3847/1538-4357/aacbd0, HESS J1943+213 is a very high energy (VHE; >100 GeV) γ-ray source in the direction of the Galactic plane. Studies exploring the classification of the source are converging toward its identification as an extreme synchrotron BL Lac object. Here we present 38 hr of VERITAS observations of HESS J1943+213 taken over 2 yr. The source is detected with a significance of ~20 standard deviations, showing a remarkably stable flux and spectrum in VHE γ-rays. Multifrequency Very Long Baseline Array (VLBA) observations of the source confirm the extended, jet-like structure previously found in the 1.6 GHz band with the European VLBI Network and detect this component in the 4.6 and 7.3 GHz bands. The radio spectral indices of the core and the jet and the level of polarization derived from the VLBA observations are in a range typical for blazars. Data from VERITAS, Fermi-LAT, Swift-XRT, the FLWO 48'' telescope, and archival infrared and hard X-ray observations are used to construct and model the spectral energy distribution (SED) of the source with a synchrotron self-Compton model. The well-measured γ-ray peak of the SED with VERITAS and Fermi-LAT provides constraining upper limits on the source redshift. Possible contribution of secondary γ-rays from ultra-high-energy cosmic-ray-initiated electromagnetic cascades to the γ-ray emission is explored, finding that only a segment of the VHE spectrum can be accommodated with this process. A variability search is performed across X-ray and γ-ray bands. No statistically significant flux or spectral variability is detected., Published by Univ.11032, Chicago, Ill. [u.a.]
Published: 2018
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30. Measurement of the iron spectrum in cosmic rays by VERITAS

Author: Archer, A., Benbow, W., Bird, R., Brose, R., Buchovecky, M., Bugaev, V., Connolly, M. P., Cui, W., Daniel, M. K., Falcone, A., Feng, Q., Finley, J. P., Fleischhack, H., Fortson, L., Furniss, A., Hanna, D., Hervet, O., Holder, J., Hughes, G., Humensky, T. B., Huetten, Moritz, Johnson, C. A., Kaaret, P., Kelley-Hoskins, N., Kieda, D., Krause, M., Krennrich, F., Kumar, S., Lang, M. J., Maier, G., McArthur, S., Moriarty, P., Mukherjee, R., Nieto, D., O’Brien, S., Ong, R. A., Otte, A. N., Park, N., Petrashyk, A., Pohl, Martin, Popkow, A., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Richards, G. T., Roache, E., Rulten, C., Sadeh, I., Tyler, J., Wakely, S. P., Weiner, O. M., Wilcox, P., Wilhelm, Alina, Williams, D. A., Wissel, S. A., and Zitzer, B.
Abstract: Physical review / D 98(2), 022009 (2018). doi:10.1103/PhysRevD.98.022009, We present a new measurement of the energy spectrum of iron nuclei in cosmic rays from 20 TeV to 500 TeV. The measurement makes use of a template-based analysis method, which, for the first time, is applied to the energy reconstruction of iron-induced air showers recorded by the VERITAS array of imaging atmospheric Cherenkov telescopes. The event selection makes use of the direct Cherenkov light which is emitted by charged particles before the first interaction, as well as other parameters related to the shape of the recorded air shower images. The measured spectrum is well described by a power law $\frac{dF}{dE} = f0 ⋅ (\frac{E}{E0})^{−\gamma}$ over the full energy range, with $\gamma = 2.82±0.30(stat)^{+0.24}_{−0.27}(syst)$ and $f_0 = (4.82±0.98(stat)^{+2.12}_{−2.70}(syst)) × 10^{−7} m^{−2} s^{−1} TeV^{−1} sr^{−1}$ at $E_0 = 50 TeV$, with no indication of a cutoff or spectral break. The measured differential flux is compatible with previous results, with improved statistical uncertainty at the highest energies., Published by Soc., [S.l.]
Published: 2018
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31. A Very High Energy γ -Ray Survey toward the Cygnus Region of the Galaxy

Author: Abeysekara, A. U., Archer, A., Falcone, A., Feng, Q., Finley, J. P., Fleischhack, H., Flinders, A., Fortson, L., Furniss, A., Gotthelf, E. V., Grube, J., Hanna, D., Aune, T., Hervet, O., Holder, J., Huang, K., Hughes, G., Humensky, T. B., Huetten, Moritz, Johnson, C. A., Kaaret, P., Kar, P., Kelley-Hoskins, N., Benbow, W., Kertzman, M., Kieda, D., Krause, M., Kumar, S., Lang, M. J., Lin, T. T. Y., Maier, Gernot, McArthur, S., Moriarty, P., Mukherjee, R., Bird, R., O’Brien, S., Ong, R. A., Otte, A. N., Pandel, D., Park, N., Petrashyk, A., Pohl, M., Popkow, A., Pueschel, Elisa, Quinn, J., Brose, R., Ragan, K., Reynolds, P. T., Richards, G. T., Roache, E., Rousselle, J., Rulten, C., Sadeh, I., Santander, M., Sembroski, G. H., Shahinyan, K., Buchovecky, M., Tyler, J., Vassiliev, V. V., Wakely, S. P., Ward, J. E., Weinstein, A., Wells, R. M., Wilcox, P., Wilhelm, Alina, Williams, D. A., Zitzer, B., Bugaev, V., Cui, W., and Daniel, M. K.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, ddc:520, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: We present results from deep observations toward the Cygnus region using 300 hr of very high energy (VHE) γ-ray data taken with the VERITAS Cerenkov telescope array and over 7 yr of high-energy γ-ray data taken with the Fermi satellite at an energy above 1 GeV. As the brightest region of diffuse γ-ray emission in the northern sky, the Cygnus region provides a promising area to probe the origins of cosmic rays. We report the identification of a potential Fermi-LAT counterpart to VER J2031+415 (TeV J2032+4130) and resolve the extended VHE source VER J2019+368 into two source candidates (VER J2018+367* and VER J2020+368*) and characterize their energy spectra. The Fermi-LAT morphology of 3FGL J2021.0+4031e (the Gamma Cygni supernova remnant) was examined, and a region of enhanced emission coincident with VER J2019+407 was identified and jointly fit with the VERITAS data. By modeling 3FGL J2015.6+3709 as two sources, one located at the location of the pulsar wind nebula CTB 87 and one at the quasar QSO J2015+371, a continuous spectrum from 1 GeV to 10 TeV was extracted for VER J2016+371 (CTB 87). An additional 71 locations coincident with Fermi-LAT sources and other potential objects of interest were tested for VHE γ-ray emission, with no emission detected and upper limits on the differential flux placed at an average of 2.3% of the Crab Nebula flux. We interpret these observations in a multiwavelength context and present the most detailed γ-ray view of the region to date.
Published: 2018
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32. The extreme HBL behaviour of Markarian 501 during 2012

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

Author: Abeysekara, A. U., Benbow, W., Bird, R., Brantseg, T., Brose, R., Buchovecky, M., Buckley, J. H., Bugaev, V., Connolly, M. P., Cui, W., Daniel, M. K., Falcone, A., Feng, Q., Finley, J. P., Fortson, L., Furniss, A., Gillanders, G. H., Gunawardhana, I., Hütten, M., Hanna, D., Hervet, O., Holder, J., Hughes, G., Humensky, T. B., Johnson, C. A., Kaaret, P., Kar, P., Kertzman, M., Krennrich, F., Lang, M. J., Lin, T. T. Y., McArthur, S., 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., Reynolds, P. T., Richards, G. T., Roache, E., Rulten, C., Sadeh, I., Santander, M., Sembroski, G. H., Shahinyan, K., Wakely, S. P., Weinstein, A., Wells, R. M., Wilcox, P., Williams, D. A., Zitzer, B., Jorstad, S. G., Marscher, A. P., Lister, M. L., Kovalev, Y. Y., Pushkarev, A. B., Savolainen, T., Agudo, I., Molina, S. N., Gómez, J. L., Larionov, V. M., Borman, G. A., Mokrushina, A. A., Tornikoski, M., Lähteenmäki, A., Chamani, W., Enestam, S., Kiehlmann, S., Hovatta, T., Smith, P. S., and Pontrelli, P.
Abstract: The astrophysical journal 856(2), 95 (2018). doi:10.3847/1538-4357/aab35c, Combined with measurements made by very-long-baseline interferometry, the observations of fast TeV gamma-ray flares probe the structure and emission mechanism of blazar jets. However, only a handful of such flares have been detected to date, and only within the last few years have these flares been observed from lower-frequency-peaked BL Lac objects and flat-spectrum radio quasars. We report on a fast TeV gamma-ray flare from the blazar BL Lacertae observed by the Very Energetic Radiation Imaging Telescope Array System (VERITAS). with a rise time of ~2.3 hr and a decay time of ~36 min. The peak flux above 200 GeV is (4.2 ± 0.6) × 10$^{−6}$ photon m$^{−2}$ s$^{−1}$ measured with a 4-minute-binned light curve, corresponding to ~180% of the flux that is observed from the Crab Nebula above the same energy threshold. Variability contemporaneous with the TeV gamma-ray flare was observed in GeV gamma-ray, X-ray, and optical flux, as well as in optical and radio polarization. Additionally, a possible moving emission feature with superluminal apparent velocity was identified in Very Long Baseline Array observations at 43 GHz, potentially passing the radio core of the jet around the time of the gamma-ray flare. We discuss the constraints on the size, Lorentz factor, and location of the emitting region of the flare, and the interpretations with several theoretical models that invoke relativistic plasma passing stationary shocks., Published by IOP Publ., Chicago, Ill. [u.a.]
Published: 2018
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34. A search for spectral hysteresis and energy-dependent time lags from X-ray and TeV gamma-ray observations of Mrk 421

Author: Abeysekara, A. U., Archambault, S., Chen, X., De Lotto, B., Wilhelmi, E. de Oña, Di Pierro, F., Doert, M., Domínguez, A., Prester, D. Dominis, Dorner, D., Doro, M., Einecke, S., Glawion, D. Eisenacher, Ciupik, L., Elsaesser, D., Engelkemeier, M., Ramazani, V. Fallah, Fernández-Barral, A., Fidalgo, D., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., López, R. J. García, Connolly, M. P., Garczarczyk, M., Gaug, M., Giammaria, P., Godinović, N., Gora, D., Guberman, D., Hadasch, D., Hahn, A., Hassan, T., Hayashida, M., Cui, W., Herrera, J., Hose, J., Hrupec, D., Hughes, G., Idec, W., Kodani, K., Konno, Y., Kubo, H., Kushida, J., Lelas, D., Eisch, J. D., Lindfors, E., Lombardi, S., Longo, F., López, M., López-Coto, R., Majumdar, P., Makariev, M., Mallot, K., Maneva, G., Manganaro, M., Falcone, A., Mannheim, K., Maraschi, L., Marcote, B., Mariotti, M., Martínez, M., Mazin, D., Menzel, U., Mirzoyan, R., Moralejo, A., Moretti, E., Feng, Q., Nakajima, D., Neustroev, V., Niedzwiecki, A., Rosillo, M. Nievas, Nilsson, K., Nishijima, K., Noda, K., Nogués, L., Nöthe, M., Paiano, S., Finley, J. P., Palacio, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Paredes-Fortuny, X., Pedaletti, G., Peresano, M., Perri, L., Persic, M., Fleischhack, H., Poutanen, J., Moroni, P. G. Prada, Prandini, E., Puljak, I., Garcia, J. R., Reichardt, I., Rhode, W., Ribó, M., Rico, J., Saito, T., Flinders, A., Satalecka, K., Schroeder, S., Schweizer, T., Shore, S. N., Sillanpää, A., Sitarek, J., Snidaric, I., Sobczynska, D., Stamerra, A., Strzys, M., Archer, A., Fortson, L., Surić, T., Takalo, L., Tavecchio, F., Temnikov, P., Terzić, T., Tescaro, D., Teshima, M., Torres, D. F., Torres-Albà, N., Toyama, T., Furniss, A., Treves, A., Vanzo, G., Acosta, M. Vazquez, Vovk, I., Ward, J. E., Will, M., Wu, M. H., Zanin, R., Hovatta, T., Perez, I. de la Calle, Griffin, S., Smith, P. S., Racero, E., Baloković, M., VERITAS Collaboration, MAGIC Collaboration, Hütten, M., Håkansson, N., Hanna, D., Hervet, O., Holder, J., Humensky, T. B., Kaaret, P., Benbow, W., Kar, P., Kertzman, M., Kieda, D., Krause, Maria, Kumar, S., Lang, M. J., Maier, G., McArthur, S., McCann, A., Meagher, K., Bird, R., Moriarty, P., Mukherjee, R., Nieto, D., O'Brien, S., Ong, R. A., Otte, A. N., Park, N., Pelassa, V., Pohl, Martin, Popkow, A., Buchovecky, M., Pueschel, E., Ragan, K., Reynolds, P. T., Richards, G. T., Roache, E., Sadeh, I., Santander, M., Sembroski, G. H., Shahinyan, K., Staszak, D., Buckley, J. H., Telezhinsky, I., Tucci, J. V., Tyler, J., Wakely, S. P., Weinstein, A., Wilhelm, Alina, Williams, D. A., Ahnen, M. L., Ansoldi, S., Antonelli, L. A., Bugaev, V., Antoranz, P., Arcaro, C., Babic, A., Banerjee, B., Bangale, P., de Almeida, U. Barres, Barrio, J. A., González, J. Becerra, Bednarek, W., Bernardini, E., Cardenzana, J. V, Berti, A., Biasuzzi, B., Biland, A., Blanch, O., Bonnefoy, S., Bonnoli, G., Borracci, F., Bretz, T., Carosi, R., Carosi, A., Cerruti, M., Chatterjee, A., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Cumani, P., Da Vela, P., Dazzi, F., De Angelis, A., Department of Radio Science and Engineering, Aalto-yliopisto, Aalto University, Universitat de Barcelona, Abeysekara, A. U., Archambault, S., Archer, A., Benbow, W., Bird, R., Buchovecky, M., Buckley, J. H., Bugaev, V., Cardenzana, J. V., Cerruti, M., Chen, X., Ciupik, L., Connolly, M. P., Cui, W., Eisch, J. D., Falcone, A., Feng, Q., Finley, J. P., Fleischhack, H., Flinders, A., Fortson, L., Furniss, A., Griffin, S., Hakansson, M. H. N., Hanna, D., Hervet, O., Holder, J., Humensky, T. B., Kaaret, P., Kar, P., Kertzman, M., Kieda, D., Krause, M., Kumar, S., Lang, M. J., Maier, G., Mcarthur, S., Mccann, A., Meagher, K., Moriarty, P., Mukherjee, R., Nieto, D., Ong, S. O. R. A., Otte, A. N., Park, N., Pelassa, V., Pohl, M., Popkow, A., Pueschel, E., Ragan, K., Reynolds, P. T., Richards, G. T., Roache, E., Sadeh, I., Santander, M., Sembroski, G. H., Shahinyan, K., Staszak, D., Telezhinsky, I., Tucci, J. V., Tyler, J., Wakely, S. P., Weinstein, A., Wilhelm, A., Williams, D. A., Ahnen, M. L., Ansoldi, S., Antonelli, L. A., Antoranz, P., Arcaro, C., Babic, A., Banerjee, B., Bangale, P., Almeida, U. Barres De, Barrio, J. A., González, J. Becerra, Bednarek, W., Bernardini, E., Berti, Alessio, Biasuzzi, B., Biland, A., Blanch, O., Bonnefoy, S., Bonnoli, G., Borracci, F., Bretz, T., Carosi, R., Carosi, A., Chatterjee, A., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Cumani, P., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., De Ona Wilhelmi, E., Di Pierro, F., Doert, M., Domínguez, A., Prester, D. Domini, Dorner, D., Doro, M., Einecke, S., Glawion, D. Eisenacher, Elsaesser, D., Engelkemeier, M., Ramazani, V. Fallah, Fernández Barral, A., Fidalgo, D., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., López, R. J. García, Garczarczyk, M., Gaug, M., Giammaria, P., Godinović, N., Gora, D., Guberman, D., Hadasch, D., Hahn, A., Hassan, T., Hayashida, M., Herrera, J., Hose, J., Hrupec, D., Hughes, G., Idec, W., Kodani, K., Konno, Y., Kubo, H., Kushida, J., Lelas, D., Lindfors, E., Lombardi, S., Longo, Francesco, López, M., López Coto, R., Majumdar, P., Makariev, M., Mallot, K., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Marcote, B., Mariotti, M., Martínez, M., Mazin, D., Menzel, U., Mirzoyan, R., Moralejo, A., Moretti, E., Nakajima, D., Neustroev, V., Niedzwiecki, A., Rosillo, M. Nieva, Nilsson, K., Nishijima, K., Noda, K., Nogués, L., Nöthe, M., Paiano, S., Palacio, J., Palatiello, Michele, Paneque, D., Paoletti, R., Paredes, J. M., Paredes Fortuny, X., Pedaletti, G., Peresano, M., Perri, L., Persic, M., Poutanen, J., Moroni, P. G. Prada, Prandini, E., Puljak, I., Garcia, J. R., Reichardt, I., Rhode, W., Ribó, M., Rico, J., Saito, T., Satalecka, K., Schroeder, S., Schweizer, T., Shore, S. N., Sillanp, A., Sitarek, J., Snidaric, I., Sobczynska, D., Stamerra, A., Strzys, M., Surić, T., Takalo, L., Tavecchio, F., Temnikov, P., Terzić, T., Tescaro, D., Teshima, M., Torres, D. F., Torres Albà, N., Toyama, T., Treves, A., Vanzo, G., Acosta, M. Vazquez, Vovk, I., Ward, J. E., Will, M., Wu, M. H., Zanin, R., Hovatta, T., De La Calle Perez, I., Smith, P. S., Racero, E., and Baloković, M.
Subjects: bl-lacertae objects, blazars, Astrophysics, telescope, 01 natural sciences, Spectral line, individual (Markarian 421) [BL Lacertae objects], law.invention, Raigs gamma, law, emission, MAGIC (telescope), 010303 astronomy & astrophysics, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Spectral index, Gamma ray, Radius, lac objects, non-thermal [radiation mechanisms], Synchrotron, xmm-newton, BL Lacertae objects: individual (Markarian 421), galaxies: active, gamma rays: general, radiation mechanisms: non-thermal, Astronomy and Astrophysics, Space and Planetary Science, correlated variability, active [galaxies], Física nuclear, Astrophysics - High Energy Astrophysical Phenomena, multiwavelength observations, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, 0103 physical sciences, Blazar, 010308 nuclear & particles physics, Gamma rays, Spectral density, Astronomy and Astrophysic, Galaxies, Galàxies, active galactic nuclei, markarian-421, ddc:520, galaxies: active – BL Lacertae objects: individual: (Markarian 421), general [gamma rays]
Abstract: The astrophysical journal 834(1), 2 (2017). doi:10.3847/1538-4357/834/1/2, Blazars are variable emitters across all wavelengths over a wide range of timescales, from months down to minutes. It is therefore essential to observe blazars simultaneously at different wavelengths, especially in the X-ray and gamma-ray bands, where the broadband spectral energy distributions usually peak. In this work, we report on three "target-of-opportunity" observations of Mrk 421, one of the brightest TeV blazars, triggered by a strong flaring event at TeV energies in 2014. These observations feature long, continuous, and simultaneous exposures with XMM-Newton (covering the X-ray and optical/ultraviolet bands) and VERITAS (covering the TeV gamma-ray band), along with contemporaneous observations from other gamma-ray facilities (MAGIC and Fermi-Large Area Telescope) and a number of radio and optical facilities. Although neither rapid flares nor significant X-ray/TeV correlation are detected, these observations reveal subtle changes in the X-ray spectrum of the source over the course of a few days. We search the simultaneous X-ray and TeV data for spectral hysteresis patterns and time delays, which could provide insight into the emission mechanisms and the source properties (e.g., the radius of the emitting region, the strength of the magnetic field, and related timescales). The observed broadband spectra are consistent with a one-zone synchrotron self-Compton model. We find that the power spectral density distribution at $\gtrsim$ 4 × 10$^{−4}$ Hz from the X-ray data can be described by a power-law model with an index value between 1.2 and 1.8, and do not find evidence for a steepening of the power spectral index (often associated with a characteristic length scale) compared to the previously reported values at lower frequencies., Published by IOP Publ., Chicago, Ill. [u.a.]
Published: 2016
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35. Deep broadband observations of the distant gamma-ray blazar PKS 1424+240

Author: Archambault, S., Aune, T., Cardenzana, J. V, de Palma, F., Dermer, C. D., Digel, S. W., Di Venere, L., Drell, P. S., Favuzzi, C., Franckowiak, A., Fusco, P., Gargano, F., Gasparrini, D., Cerruti, M., Giglietto, N., Giordano, Francesca, Giroletti, M., Grenier, I. A., Guiriec, S., Jogler, T., Kuss, M., Larsson, S., Latronico, L., Longo, F., Chen, X., Loparco, F., Lubrano, P., Madejski, G. M., Mayer, M., Mazziotta, M. N., Michelson, P. F., Mizuno, T., Monzani, M. E., Morselli, A., Murgia, S., Ciupik, L., Nuss, E., Ohsugi, T., Ormes, J. F., Paneque, D., Perkins, J. S., Piron, F., Pivato, G., Rainò, S., Razzano, M., Reimer, A., Connolly, M. P., Reimer, O., Ritz, S., Schaal, M., Sgrò, C., Siskind, E. J., Spinelli, P., Takahashi, H., Tibaldo, L., Tinivella, M., Troja, E., Cui, W., Vianello, G., Werner, M., Wood, M., VERITAS Collaboration, Fermi-LAT Collaboration, Dumm, J., Errando, M., Falcone, A., Federici, S., Behera, B., Feng, Q., Finley, J. P., Fleischhack, H., Fortson, L., Furniss, A., Galante, N., Gillanders, G. H., Griffin, S., Griffiths, S. T., Grube, J., Beilicke, M., Gyuk, G., Hanna, D., Holder, J., Hughes, G., Humensky, T. B., Johnson, C. A., Kaaret, P., Kertzman, M., Khassen, Y., Kieda, D., Benbow, W., Krawczynski, H., Krennrich, F., Kumar, S., Lang, M. J., Madhavan, A. S, Maier, G., McCann, A., Meagher, K., Moriarty, P., Mukherjee, R., Berger, K., Nieto, D., de Bhróithe, A. O'Faoláin, Ong, R. A., Otte, A. N., Park, N., Pohl, M., Popkow, A., Prokoph, H., Quinn, J., Ragan, K., Bird, R., Rajotte, J., Reyes, L. C., Reynolds, P. T., Richards, G. T., Roache, E., Sembroski, G. H., Shahinyan, K., Staszak, D., Telezhinsky, I., Tucci, J. V., Biteau, J., Tyler, J., Varlotta, A., Vassiliev, V. V., Vincent, S., Wakely, S. P., Weinstein, A., Welsing, R., Wilhelm, A., Williams, D. A., Ackermann, M., Bugaev, V., Ajello, M., Albert, A., Baldini, L., Bastieri, D., Bellazzini, R., Bissaldi, E., Bregeon, J., Buehler, R., Buson, S., Caliandro, G. A., Byrum, K., Cameron, R. A., Caraveo, P. A., Cavazzuti, E., Charles, E., Chiang, J., Ciprini, S., Claus, R., Cutini, S., D'Ammando, F., de Angelis, A., Laboratoire Univers et Particules de Montpellier (LUPM), Université de Montpellier (UM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), VERITAS, Fermi-LAT, Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), Archambault, S., Aune, T., Behera, B., Beilicke, M., Benbow, W., Berger, K., Bird, R., Biteau, J., Bugaev, V., Byrum, K., Cardenzana, J. V., Cerruti, M., Chen, X., Ciupik, L., Connolly, M. P., Cui, W., Dumm, J., Errando, M., Falcone, A., Federici, S., Feng, Q., Finley, J. P., Fleischhack, H., Fortson, L., Furniss, A., Galante, N., Gillanders, G. H., Griffin, S., Griffiths, S. T., Grube, J., Gyuk, G., Hanna, D., Holder, J., Hughes, G., Humensky, T. B., Johnson, C. A., Kaaret, P., Kertzman, M., Khassen, Y., Kieda, D., Krawczynski, H., Krennrich, F., Kumar, S., Lang, M. J., Madhavan, A. S., Maier, G., Mccann, A., Meagher, K., Moriarty, P., Mukherjee, R., Nieto, D., De Bhróithe, A. O'Faoláin, Ong, R. A., Otte, A. N., Park, N., Pohl, M., Popkow, A., Prokoph, H., Quinn, J., Ragan, K., Rajotte, J., Reyes, L. C., Reynolds, P. T., Richards, G. T., Roache, E., Sembroski, G. H., Shahinyan, K., Staszak, D., Telezhinsky, I., Tucci, J. V., Tyler, J., Varlotta, A., Vassiliev, V. V., Vincent, S., Wakely, S. P., Weinstein, A., Welsing, R., Wilhelm, A., Williams, D. A., Ackermann, M., Ajello, M., Albert, A., Baldini, L., Bastieri, D., Bellazzini, R., Bissaldi, Elisabetta, Bregeon, J., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cavazzuti, E., Charles, E., Chiang, J., Ciprini, S., Claus, R., Cutini, S., D'Ammando, F., De Angelis, A., De Palma, F., Dermer, C. D., Digel, S. W., Di Venere, L., Drell, P. S., Favuzzi, C., Franckowiak, A., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Grenier, I. A., Guiriec, S., Jogler, T., Kuss, M., Larsson, S., Latronico, L., Longo, Francesco, Loparco, F., Lubrano, P., Madejski, G. M., Mayer, M., Mazziotta, M. N., Michelson, P. F., Mizuno, T., Monzani, M. E., Morselli, A., Murgia, S., Nuss, E., Ohsugi, T., Ormes, J. F., Paneque, D., Perkins, J. S., Piron, F., Pivato, G., Rainò, S., Razzano, M., Reimer, A., Reimer, O., Ritz, S., Schaal, M., Sgrò, C., Siskind, E. J., Spinelli, P., Takahashi, H., Tibaldo, L., Tinivella, M., Troja, E., Vianello, G., Werner, M., Wood, M., Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Archambault S, Aune T, Behera B, Beilicke M, Benbow W, Berger K, Bird R, Biteau J, Bugaev V, Byrum K, Cardenzana JV, Cerruti M, Chen X, Ciupik L, Connolly MP, Cui W, Dumm J, Errando M, Falcone A, Federici S, Feng Q, Finley JP, Fleischhack H, Fortson L, Furniss A, Galante N, Gillanders GH, Griffin S, Griffiths ST, Grube J, Gyuk G, Hanna D, Holder J, Hughes G, Humensky TB, Johnson CA, Kaaret P, Kertzman M, Khassen Y, Kieda D, Krawczynski H, Krennrich F, Kumar S, Lang MJ, Madhavan AS, Maier G, McCann A, Meagher K, Moriarty P, Mukherjee R, Nieto D, de Bhroithe AO, Ong RA, Otte AN, Park N, Pohl M, Popkow A, Prokoph H, Quinn J, Ragan K, Rajotte J, Reyes LC, Reynolds PT, Richards GT, Roache E, Sembroski GH, Shahinyan K, Staszak D, Telezhinsky I, Tucci JV, Tyler J, Varlotta A, Vassiliev VV, Vincent S, Wakely SP, Weinstein A, Welsing R, Wilhelm A, Williams DA, Ackermann M, Ajello M, Albert A, Baldini L, Bastieri D, Bellazzini R, Bissaldi E, Bregeon J, Buehler R, Buson S, Caliandro GA, Cameron RA, Caraveo PA, Cavazzuti E, Charles E, Chiang J, Ciprini S, Claus R, Cutini S, DAmmando F, de Angelis A, de Palma F, Dermer CD, Digel SW, Di Venere L, Drell PS, Favuzzi C, Franckowiak A, Fusco P, Gargano F, Gasparrini D, Giglietto N, Giordano F, Giroletti M, Grenier IA, Guiriec S, Jogler T, Kuss M, Larsson S, Latronico L, Longo F, Loparco F, Lubrano P, Madejski GM, Mayer M, Mazziotta MN, Michelson PF, Mizuno T, Monzani ME, Morselli A, Murgia S, Nuss E, Ohsugi T, Ormes JF, Paneque D, Perkins JS, Piron F, Pivato G, Raino S, Razzano M, Reimer A, Reimer O, Ritz S, Schaal M, Sgro C, Siskind EJ, Spinelli P, Takahashi H, Tibaldo L, Tinivella M, Troja E, Vianello G, Werner M, Wood M, Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112))
Subjects: extragalactic background light, Flux, photon: absorption, Astrophysics, cosmic radiation: interaction, individual (PKS 1424+240)-cosmic background radiation, gamma rays: galaxies [BL Lacertae objects], 01 natural sciences, Absorption (logic), gamma ray: flux, 010303 astronomy & astrophysics, photon: flux, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Gamma ray, universe, large-area telescope, Extragalactic background light, statistics, VERITAS, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, BL Lacertae objects: individual (PKS 1424+240)-cosmic background radiation, gamma rays: galaxies, spectra, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, space-telescope mission, VHE, blazar, 0103 physical sciences, detector: optical, Blazar, energy cosmic-ray, Astrophysics::Galaxy Astrophysics, tev blazars, 010308 nuclear & particles physics, background, Institut für Physik und Astronomie, opacity, Astronomy and Astrophysics, Light curve, redshift, Redshift, radiation, pair production, 13. Climate action, Space and Planetary Science, ddc:520, spectral, BL Lacertae objects: individual (PKS 1424+240)-cosmic background radiation, gamma rays: galaxies, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], absorption, X-ray: detector, Fermi Gamma-ray Space Telescope
Abstract: We present deep VERITAS observations of the blazar PKS 1424+240, along with contemporaneous Fermi Large Area Telescope, Swift X-ray Telescope and Swift UV Optical Telescope data between 2009 February 19 and 2013 June 8. This blazar resides at a redshift of $z\ge0.6035$, displaying a significantly attenuated gamma-ray flux above 100 GeV due to photon absorption via pair-production with the extragalactic background light. We present more than 100 hours of VERITAS observations from three years, a multiwavelength light curve and the contemporaneous spectral energy distributions. The source shows a higher flux of (2.1$\pm0.3$)$\times10^{-7}$ ph m$^{-2}$s$^{-1}$ above 120 GeV in 2009 and 2011 as compared to the flux measured in 2013, corresponding to (1.02$\pm0.08$)$\times10^{-7}$ ph m$^{-2}$s$^{-1}$ above 120 GeV. The measured differential very high energy (VHE; $E\ge100$ GeV) spectral indices are $\Gamma=$3.8$\pm$0.3, 4.3$\pm$0.6 and 4.5$\pm$0.2 in 2009, 2011 and 2013, respectively. No significant spectral change across the observation epochs is detected. We find no evidence for variability at gamma-ray opacities of greater than $\tau=2$, where it is postulated that any variability would be small and occur on longer than year timescales if hadronic cosmic-ray interactions with extragalactic photon fields provide a secondary VHE photon flux. The data cannot rule out such variability due to low statistics., Comment: ApJL accepted March 17, 2014
Published: 2014
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36. Multimessenger observations of a flaring blazar coincident with high-energy neutrino IceCube-170922A

Author: Aartsen, M. G., Ackermann, M., Adams, J., Aguilar, J. A., Ahlers, M., Ahrens, M., Al Samarai, I., Altmann, D., Andeen, K., Anderson, T., Ansseau, I., Anton, G., Argüelles, C., Auffenberg, J., Axani, S., Bagherpour, H., Bai, X., Barron, J. P., Barwick, S. W. Baum V., Bay, R., Beatty, J. J., Becker Tjus, J., Becker, K. -H., Benzvi, S., Berley, D., Bernardini, E., Besson, D. Z., Binder, G., Bindig, D., Blaufuss, E., Blot, S., Bohm, C., Börner, M., Bos, F., Böser, S., Botner, O., Bourbeau, E., Bourbeau, J., Bradascio, F., Braun, J., Brenzke, M., Bretz, H. -P., Bron, S., Brostean-Kaiser, J., Burgman, A., Busse, R. S., Carver, T., Cheung, E., Chirkin, D., Christov, A., Clark, K., Classen, L., Coenders, S., Collin, G. H., Conrad, J. M., Coppin, P., Correa, P., Cowen, D. F., Cross, R., Dave, P., Day, M., de André, J. P. A. M., De Clercq, C., Delaunay, J. J., Dembinski, H., De Ridder, S., Desiati, P., de Vries, K. D., de Wasseige, G., de With, M., Deyoung, T., Díaz-Vélez, J. C., di Lorenzo, V., Dujmovic, H., Dumm, J. P., Dunkman, M., Dvorak, E., Eberhardt, B., Ehrhardt, T., Eichmann, B., Eller, P., Evenson, P. A., Fahey, S., Fazely, A. R., Felde, J., Filimonov, K., Finley, C., Flis, S., Franckowiak, A., Friedman, E., Fritz, A., Gaisser, T. K., Gallagher, J., Gerhardt, L., Ghorbani, K., Glauch, T., Glüsenkamp, T., Goldschmidt, A., Gonzalez, J. G., Grant, D., Griffith, Z., Haack, C., Hallgren, A., Halzen, F., Hanson, K., Hebecker, D., Heereman, D., Helbing, K., Hellauer, R., Hickford, S., Hignight, J., Hill, G. C., Hoffman, K. D., Hoffmann, R., Hoinka, T., Hokanson-Fasig, B., Hoshina, K., Huang, F., Huber, M., Hultqvist, K., Hünnefeld, M., Hussain, R., In, S., Iovine, N., Ishihara, A., Jacobi, E., Japaridze, G. S., Jeong, M., Jero, K., Jones, B. J. P., Kalaczynski, P., Kang, W., Kappes, A., Kappesser, D., Karg, T., Karle, A., Katz, U., Kauer, M., Keivani, A., Kelley, J. L., Kheirandish, A., Kim, J., Kim, M., Kintscher, T., Kiryluk, J., Kittler, T., Klein, S. R., Koirala, R., Kolanoski, H., Köpke, L., Kopper, C., Kopper, S., Koschinsky, J. P., Koskinen, D. J., Kowalski, M., Krings, K., Kroll, M., Krückl, G., Kunwar, S., Kurahashi, N., Kuwabara, T., Kyriacou, A., Labare, M., Lanfranchi, J. L., Larson, M. J., Lauber, F., Leonard, K., Lesiak-Bzdak, M., Leuermann, M., Liu, Q. R., Lozano Mariscal, C. J., Lu, L., Lünemann, J., Luszczak, W., Madsen, J., Maggi, G., Mahn, K. B. M., Mancina, S., Maruyama, R., Mase, K., Maunu, R., Meagher, K., Medici, M., Meier, M., Menne, T., Merino, G., Meures, T., Miarecki, S., Micallef, J., Momenté, G., Montaruli, T., Moore, R. W., S, Morse, R., Moulai, M., Nahnhauer, R., Nakarmi, P., Naumann, U., Neer, G., Niederhausen, H., Nowicki, S. C., Nygren, D. R., Obertacke Pollmann, A., Olivas, A., O'Murchadha, A., O'Sullivan, E., Palczewski, T., Pandya, H., Pankova, D. V., Peiffer, P., Pepper, J. A., Pérez de los Heros, C., Pieloth, D., Pinat, E., Plum, M., Price, P. B., Przybylski, G. T., Raab, C., Rädel, L., Rameez, M., Rauch, L., Rawlins, K., Rea, I. C., Reimann, R., Relethford, B., Relich, M., Resconi, E., Rhode, W., Richman, M., Robertson, S., Rongen, M., Rott, C., Ruhe, T., Ryckbosch, D., Rysewyk, D., Safa, I., Sälzer, T., Sanchez Herrera, S. E., Sandrock, A., Sandroos, J., Santander, M., Sarkar, S., Satalecka, K., Schlunder, P., Schmidt, T., Schneider, A., Schoenen, S., Schöneberg, S., Schumacher, L., Sclafani, S., Seckel, D., Seunarine, S., Soedingrekso, J., Soldin, D., Song, M., Spiczak, G. M., Spiering, C., Stachurska, J., Stamatikos, M., Stanev, T., Stasik, A., Stein, R., Stettner, J., Steuer, A., Stezelberger, T., Stokstad, R. G., Stößl, A., Strotjohann, N. L., Stuttard, T., Sullivan, G. W., Sutherland, M., Taboada, I., Tatar, J., Tenholt, F., Ter-Antonyan, S., Terliuk, A., Tilav, S., Toale, P. A., Tobin, M. N., Toennis, C., Toscano, S., Tosi, D., Tselengidou, M., Tung, C. F., Turcati, A., Turley, C. F., Ty, B., Unger, E., Usner, M., Vandenbroucke, J., Van Driessche, W., van Eijk, D., van Eijndhoven, N., Vanheule, S., van Santen, J., Vogel, E., Vraeghe, M., Walck, C., Wallace, A., Wallraff, M., Wandler, F. D., Wandkowsky, N., Waza, A., Weaver, C., Weiss, M. J., Wendt, C., Werthebach, J., Westerhoff, S., Whelan, B. J., Whitehorn, N., Wiebe, K., Wiebusch, C. H., Wille, L., Williams, D. R., Wills, L., Wolf, M., Wood, J., Wood, T. R., Woschnagg, K., D. L., Xu, X. W., Xu, Xu, Y., Yanez, J. P., Yodh, G., Yoshida, S., Yuan, T., Fermi-LAT, Collaboration, Abdollahi, S., Ajello, M., Angioni, R., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Bissaldi, E., Blandford, R. D., Bonino, R., Bottacini, E., Bregeon, J., Bruel, P., Buehler, R., Burnett, T. H., Burns, E., Buson, S., Cameron, R. A., Caputo, R., Caraveo, P. A., Cavazzuti, E., Charles, E., Chen, S., Cheung, C. C., Chiang, J., Chiaro, G., Ciprini, S., Cohen-Tanugi, J., Conrad, J., Costantin, D., Cutini, S., D'Ammando, F., de Palma, F., Digel, S. W., Di Lalla, N., Di Mauro, M., Di Venere, L., Domínguez, A., Favuzzi, C., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giomi, M., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Green, D., Grenier, I. A., Grondin, M. -H., Guiriec, S., Harding, A. K., Hayashida, M., Hays, E., Hewitt, J. W., Horan, D., Jóhannesson, G., Kadler, M., Kensei, S., Kocevski, D., Krauss, F., Kreter, M., Kuss, M., La Mura, G., Larsson, S., Latronico, L., Lemoine-Goumard, M., Li, J., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Magill, J. D., Maldera, S., Malyshev, D., Manfreda, A., Mazziotta, M. N., Mcenery, J. E., Meyer, M., Michelson, P. F., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Negro, M., Nuss, E., Ojha, R., Omodei, N., Orienti, M., Orlando, E., Palatiello, M., Paliya, V. S., Perkins, J. S., Persic, M., Pesce-Rollins, M., Piron, F., Porter, T. A., Principe, G., Rainò, S., Rando, R., Rani, B., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Renault-Tinacci, N., Ritz, S., Rochester, L. S., Saz Parkinson, P. M., Sgrò, C., Siskind, E. J., Spandre, G., Spinelli, P., Suson, D. J., Tajima, H., Takahashi, M., Tanaka, Y., Thayer, J. B., Thompson, D. J., Tibaldo, L., Torres, D. F., Torresi, E., Tosti, G., Troja, E., Valverde, J., Vianello, G., Vogel, M., Wood, K., Wood, M., Zaharijas, G., Magic, Collaboration, Ahnen, M. L., Ansoldi, S., Antonelli, L. A., Arcaro, C., Baack, D., Babić, A., Banerjee, B., Bangale, P., Barres de Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Berti, A., Bhattacharyya, W., Biland, A., Blanch, O., Bonnoli, G., Carosi, A., Carosi, R., Ceribella, G., Chatterjee, A., Colak, S. M., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Cumani, P., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Di Pierro, F., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Elsaesser, D., Fallah Ramazani, V., Fernández-Barral, A., Fidalgo, D., Foffano, L., Pfrang, K., Fonseca, M. V., Font, L., Franceschini, A., Fruck, C., Galindo, D., Gallozzi, S., García López, R. J., Garczarczyk, M., Gaug, M., Giammaria, P., Godinović, N., Gora, D., Guberman, D., Hadasch, D., Hahn, A., Hassan, T., Herrera, J., Hose, J., Hrupec, D., Inoue, S., Ishio, K., Konno, Y., Kubo, H., Kushida, J., Lelas, D., Lindfors, E., Lombardi, S., López, M., Maggio, C., Majumdar, P., Makariev, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Masuda, S., Mazin, D., Minev, M., J. M., M, Mirzoyan, R., Moralejo, A., Moreno, V., Moretti, E., Nagayoshi, T., Neustroev, V., Niedzwiecki, A., Nievas Rosillo, M., Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Paiano, S., Palacio, J., Paneque, D., Paoletti, R., Paredes, J. M., Pedaletti, G., Peresano, M., Prada Moroni, P. G., Prandini, E., Puljak, I., Rodriguez Garcia, J., Reichardt, I., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saito, T., Schweizer, T., Sitarek, J., Šnidaric ́, I., Sobczynska, D., Stamerra, A., Strzys, M., Surić, T., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Torres-Albà, N., Treves, A., Tsujimoto, S., Vanzo, G., Vazquez Acosta, M., Vovk, I., Ward, J. E., Will, M., Zaric ́, D., Agile, Team, Lucarelli, F., Tavani, M., Piano, G., Donnarumma, I., Pittori, C., Verrecchia, F., Bulgarelli, A., Caraveo, P., Cattaneo, P. W., Colafrancesco, S., Costa, E., Di Cocco, G., Ferrari, A., Gianotti, F., Giuliani, A., Lipari, P., Mereghetti, S., Pacciani, L., Paoletti, F., Parmiggiani, N., Pellizzoni, A., Picozza, P., Pilia, M., Rappoldi, A., Trois, A., Vercellone, S., Vittorini, V., ASAS-SN, Team, Stanek, A. Franckowiak K. Z., Kochanek, C. S., Beacom, J. F., Thompson, T. A., Holoien, T. W. -S., Dong, S., Prieto, J. L., Shappee, B. J., Holmbo, S., Hawc, Collaboration, Abeysekara, A. U., Albert, A., Alfaro, R., Alvarez, C., Arceo, R., Arteaga-Velázquez, J. C., Avila Rojas, D., Ayala Solares, H. A., Becerril, A., Belmont-Moreno, E., Bernal, A., Caballero-Mora, K. S., Capistrán, T., Carramiñana, A., Casanova, S., Castillo, M., Cotti, U., Cotzomi, J., Coutiño de León, S., De León, C., De la Fuente, E., Diaz Hernandez, R., Dichiara, S., Dingus, B. L., Duvernois, M. A., Ellsworth, R. W., Engel, K., Fiorino, D. W., Fleischhack, H., Fraija, N., García-González, J. A., Garfias, F., González Muñoz, A., González, M. M., Goodman, J. A., Hampel-Arias, Z., Harding, J. P., Hernandez, S., Hona, B., Hueyotl-Zahuantitla, F., Hui, C. M., Hüntemeyer, P., Iriarte, A., Jardin-Blicq, A., Joshi, V., Kaufmann, S., Kunde, G. J., Lara, A., Lauer, R. J., Lee, W. H., Lennarz, D., León Vargas, H., Linnemann, J. T., Longinotti, A. L., Luis-Raya, G., Luna-García, R., Malone, K., Marinelli, S. S., Martinez, O., Martinez-Castellanos, I., Martínez-Castro, J., Martínez-Huerta, H., Matthews, J. A., Miranda-Romagnoli, P., Moreno, E., Mostafá, M., Nayerhoda, A., Nellen, L., Newbold, M., Nisa, M. U., Noriega-Papaqui, R., Pelayo, R., Pretz, J., Pérez-Pérez, E. G., Ren, Z., Rho, C. D., Rivière, C., Rosa-González, D., Rosenberg, M., Ruiz-Velasco, E., Salesa Greus, F., Sandoval, A., Schneider, M., Schoorlemmer, H., Sinnis, G., Smith, A. J., Springer, R. W., Surajbali, P., Tibolla, O., Tollefson, K., Torres, I., Villaseñor, L., Weisgarber, T., Werner, F., Yapici, T., Gaurang, Y., Zepeda, A., Zhou, H., Álvarez, J. D., Collaboration, H. E. S. S., Abdalla, H., Angüner, E. O., Armand, C., Backes, M., Becherini, Y., Berge, D., Böttcher, M., Boisson, C., Bolmont, J., Bonnefoy, S., Bordas, P., Brun, F., Büchele, M., Bulik, T., Caroff, S., Cerruti, M., Chakraborty, N., Chandra, S., Chen, A., Davids, I. D., Deil, C., Devin, J., Djannati-Ataï, A., Egberts, K., Emery, G., Eschbach, S., Fiasson, A., Fontaine, G., Füßling, M., Gallant, Y. A., Gaté, F., Giavitto, G., Glawion, D., Glicenstein, J. F., Gottschall, D., Haupt, M., Henri, G., Hinton, J. A., Hoischen, C., Holch, T. L., Huber, D., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jouvin, L., Jung-Richardt, I., Kerszberg, D., Khélifi, B., King, J., Klepser, S., Kluz ́niak, W., Komin, Nu., Kraus, M., Lefaucheur, J., Lemière, A., Lenain, J. -P., Leser, E., Lohse, T., López-Coto, R., Lorentz, M., Lypova, I., Marandon, V., Guillem Martí-Devesa, G., Maurin, G., Mitchell, A. M. W., Moderski, R., Mohamed, M., Mohrmann, L., Moulin, E., Murach, T., de Naurois, M., Niederwanger, F., Niemiec, J., Oakes, L., O'Brien, P., Ohm, S., Ostrowski, M., Oya, I., Panter, M., Parsons, R. D., Perennes, C., Piel, Q., Pita, S., Poireau, V., Priyana Noel, A., Prokoph, H., Pühlhofer, G., Quirrenbach, A., Raab, S., Rauth, R., Renaud, M., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Sasaki, D. A., Sanchez, M., Schlickeiser, R., Schüssler, F., Schulz, A., Schwanke, U., Seglar-Arroyo, M., Shafi, N., Simoni, R., Sol, H., Stegmann, C., Steppa, C., Tavernier, T., Taylor, A. M., Tiziani, D., Trichard, C., Tsirou, M., van Eldik, C., van Rensburg, C., van Soelen, B., Veh, J., Vincent, P., Voisin, F., Wagner, S. J., Wagner, R. M., Wierzcholska, A., Zanin, R., Zdziarski, A. A., Zech, A., Ziegler, A., Zorn, J., Żywucka, N., Integral, Team, Savchenko, V., Ferrigno, C., Bazzano, A., Diehl, R., Kuulkers, E., Laurent, P., Natalucci, L., Panessa, F., Rodi, J., Ubertini, P., Kanata Kiso and Subaru Observing Teams, Morokuma, T., Ohta, K., Tanaka, Y. T., Mori, H., Yamanaka, M., Kawabata, K. S., Utsumi, Y., Nakaoka, T., Kawabata, M., Nagashima, H., Yoshida, M., Matsuoka, Y., Itoh, R., Kapteyn, Team, Keel, W., Liverpool Telescope Team, Copperwheat, C., Steele, I., Swift/nustar, Team, Cenko, S. B., Evans, P. A., Fox, D. B., Kennea, J. A., Marshall, F. E., Osborne, J. P., Tohuvavohu, A., Veritas, Collaboration, Archer, A., Benbow, W., Bird, R., Brill, A., Brose, R., Buchovecky, M., Buckley, J. H., Bugaev, V., Christiansen, J. L., Connolly, M. P., Cui, W., Daniel, M. K., Errando, M., Falcone, A., Feng, Q., Finley, J. P., Fortson, L., Furniss, A., Gueta, O., Hütten, M., Hervet, O., Hughes, G., Humensky, T. B., Johnson, C. A., Kaaret, P., Kar, P., Kelley-Hoskins, N., Kertzman, M., Kieda, D., Krause, M., Krennrich, F., Kumar, S., Lang, M. J., Lin, T. T. Y., Maier, G., Mcarthur, S., Moriarty, P., Mukherjee, R., Nieto, D., O'Brien, S., Ong, R. A., Otte, A. N., Park, N., Petrashyk, A., Pohl, M., Popkow, A., Pueschel, S. E., Quinn, J., Ragan, K., Reynolds, P. T., Richards, G. T., Roache, E., Rulten, C., Sadeh, I., Scott, S. S., Sembroski, G. H., Shahinyan, K., Sushch, I., Trépanier, S., Tyler, J., Vassiliev, V. V., Wakely, S. P., Weinstein, A., Wells, R. M., Wilcox, P., Wilhelm, A., Williams, D. A., Zitzer, B., Vla/b, Team, Tetarenko, A. J., Kimball, A. E., Miller-Jones, J. C. A., Sivakoff, G. R., Massachusetts Institute of Technology. Laboratory for Nuclear Science, Massachusetts Institute of Technology. Department of Nuclear Science and Engineering, Massachusetts Institute of Technology. Department of Physics, ITA, High Energy Astrophys. & Astropart. Phys (API, FNWI), Faculty of Science, API Other Research (FNWI), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Particules de Montpellier (LUPM), Université de Montpellier (UM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Centre de Physique des Particules de Marseille (CPPM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Aix Marseille Université (AMU), Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Département d'Astrophysique (ex SAP) (DAP), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, IceCube, Fermi-LAT, Kapteyn, Liverpool Telescope, Subaru, Swift NuSTAR, VERITAS, VLA/17B-403, MAGIC, AGILE, ASAS-SN, HAWC, H.E.S.S., INTEGRAL, Kanata, Kiso, Aartsen, M. G., Ackermann, M., Adams, J., Aguilar, J. A., Ahlers, M., Ahrens, M., Al Samarai, I., Altmann, D., Andeen, K., Anderson, T., Ansseau, I., Anton, G., Argüelles, C., Auffenberg, J., Axani, S., Bagherpour, H., Bai, X., Barron, J. P., Barwick, S. W., Baum, V., Bay, R., Beatty, J. J., Becker Tjus, J., Becker, K. -H., Benzvi, S., Berley, D., Bernardini, E., Besson, D. Z., Binder, G., Bindig, D., Blaufuss, E., Blot, S., Bohm, C., Börner, M., Bos, F., Böser, S., Botner, O., Bourbeau, E., Bourbeau, J., Bradascio, F., Braun, J., Brenzke, M., Bretz, H. -P., Bron, S., Brostean-Kaiser, J., Burgman, A., Busse, R. S., Carver, T., Cheung, E., Chirkin, D., Christov, A., Clark, K., Classen, L., Coenders, S., Collin, G. H., Conrad, J. M., Coppin, P., Correa, P., Cowen, D. F., Cross, R., Dave, P., Day, M., de André, J. P. A. M., De Clercq, C., Delaunay, J. J., Dembinski, H., De Ridder, S., Desiati, P., de Vries, K. D., de Wasseige, G., de With, M., Deyoung, T., Díaz-Vélez, J. C., Di Lorenzo, V., Dujmovic, H., Dumm, J. P., Dunkman, M., Dvorak, E., Eberhardt, B., Ehrhardt, T., Eichmann, B., Eller, P., Evenson, P. A., Fahey, S., Fazely, A. R., Felde, J., Filimonov, K., Finley, C., Flis, S., Franckowiak, A., Friedman, E., Fritz, A., Gaisser, T. K., Gallagher, J., Gerhardt, L., Ghorbani, K., Glauch, T., Glüsenkamp, T., Goldschmidt, A., Gonzalez, J. G., Grant, D., Griffith, Z., Haack, C., Hallgren, A., Halzen, F., Hanson, K., Hebecker, D., Heereman, D., Helbing, K., Hellauer, R., Hickford, S., Hignight, J., Hill, G. C., Hoffman, K. D., Hoffmann, R., Hoinka, T., Hokanson-Fasig, B., Hoshina, K., Huang, F., Huber, M., Hultqvist, K., Hünnefeld, M., Hussain, R., In, S., Iovine, N., Ishihara, A., Jacobi, E., Japaridze, G. S., Jeong, M., Jero, K., Jones, B. J. P., Kalaczynski, P., Kang, W., Kappes, A., Kappesser, D., Karg, T., Karle, A., Katz, U., Kauer, M., Keivani, A., Kelley, J. L., Kheirandish, A., Kim, J., Kim, M., Kintscher, T., Kiryluk, J., Kittler, T., Klein, S. R., Koirala, R., Kolanoski, H., Köpke, L., Kopper, C., Kopper, S., Koschinsky, J. P., Koskinen, D. J., Kowalski, M., Krings, K., Kroll, M., Krückl, G., Kunwar, S., Kurahashi, N., Kuwabara, T., Kyriacou, A., Labare, M., Lanfranchi, J. L., Larson, M. J., Lauber, F., Leonard, K., Lesiak-Bzdak, M., Leuermann, M., Liu, Q. R., Lozano Mariscal, C. J., Lu, L., Lünemann, J., Luszczak, W., Madsen, J., Maggi, G., Mahn, K. B. M., Mancina, S., Maruyama, R., Mase, K., Maunu, R., Meagher, K., Medici, M., Meier, M., Menne, T., Merino, G., Meures, T., Miarecki, S., Micallef, J., Momenté, G., Montaruli, T., Moore, R. W., Morse, R., Moulai, M., Nahnhauer, R., Nakarmi, P., Naumann, U., Neer, G., Niederhausen, H., Nowicki, S. C., Nygren, D. R., Obertacke Pollmann, A., Olivas, A., O’Murchadha, A., O’Sullivan, E., Palczewski, T., Pandya, H., Pankova, D. V., Peiffer, P., Pepper, J. A., Pérez de los Heros, C., Pieloth, D., Pinat, E., Plum, M., Price, P. B., Przybylski, G. T., Raab, C., Rädel, L., Rameez, M., Rauch, L., Rawlins, K., Rea, I. C., Reimann, R., Relethford, B., Relich, M., Resconi, E., Rhode, W., Richman, M., Robertson, S., Rongen, M., Rott, C., Ruhe, T., Ryckbosch, D., Rysewyk, D., Safa, I., Sälzer, T., Sanchez Herrera, S. E., Sandrock, A., Sandroos, J., Santander, M., Sarkar, S., Satalecka, K., Schlunder, P., Schmidt, T., Schneider, A., Schoenen, S., Schöneberg, S., Schumacher, L., Sclafani, S., Seckel, D., Seunarine, S., Soedingrekso, J., Soldin, D., Song, M., Spiczak, G. M., Spiering, C., Stachurska, J., Stamatikos, M., Stanev, T., Stasik, A., Stein, R., Stettner, J., Steuer, A., Stezelberger, T., Stokstad, R. G., Stößl, A., Strotjohann, N. L., Stuttard, T., Sullivan, G. W., Sutherland, M., Taboada, I., Tatar, J., Tenholt, F., Ter-Antonyan, S., Terliuk, A., Tilav, S., Toale, P. A., Tobin, M. N., Toennis, C., Toscano, S., Tosi, D., Tselengidou, M., Tung, C. F., Turcati, A., Turley, C. F., Ty, B., Unger, E., Usner, M., Vandenbroucke, J., Van Driessche, W., van Eijk, D., van Eijndhoven, N., Vanheule, S., van Santen, J., Vogel, E., Vraeghe, M., Walck, C., Wallace, A., Wallraff, M., Wandler, F. D., Wandkowsky, N., Waza, A., Weaver, C., Weiss, M. J., Wendt, C., Werthebach, J., Westerhoff, S., Whelan, B. J., Whitehorn, N., Wiebe, K., Wiebusch, C. H., Wille, L., Williams, D. R., Wills, L., Wolf, M., Wood, J., Wood, T. R., Woschnagg, K., Xu, D. L., Xu, X. W., Xu, Y., Yanez, J. P., Yodh, G., Yoshida, S., Yuan, T., Abdollahi, S., Ajello, M., Angioni, R., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Bissaldi, E., Blandford, R. D., Bonino, R., Bottacini, E., Bregeon, J., Bruel, P., Buehler, R., Burnett, T. H., Burns, E., Buson, S., Cameron, R. A., Caputo, R., Caraveo, P. A., Cavazzuti, E., Charles, E., Chen, S., Cheung, C. C., Chiang, J., Chiaro, G., Ciprini, S., Cohen-Tanugi, J., Conrad, J., Costantin, D., Cutini, S., D’Ammando, F., de Palma, F., Digel, S. W., Di Lalla, N., Di Mauro, M., Di Venere, L., Domínguez, A., Favuzzi, C., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giomi, M., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Green, D., Grenier, I. A., Grondin, M. -H., Guiriec, S., Harding, A. K., Hayashida, M., Hays, E., Hewitt, J. W., Horan, D., Jóhannesson, G., Kadler, M., Kensei, S., Kocevski, D., Krauss, F., Kreter, M., Kuss, M., La Mura, G., Larsson, S., Latronico, L., Lemoine-Goumard, M., Li, J., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Magill, J. D., Maldera, S., Malyshev, D., Manfreda, A., Mazziotta, M. N., Mcenery, J. E., Meyer, M., Michelson, P. F., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Negro, M., Nuss, E., Ojha, R., Omodei, N., Orienti, M., Orlando, E., Palatiello, M., Paliya, V. S., Perkins, J. S., Persic, M., Pesce-Rollins, M., Piron, F., Porter, T. A., Principe, G., Rainò, S., Rando, R., Rani, B., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Renault-Tinacci, N., Ritz, S., Rochester, L. S., Saz Parkinson, P. M., Sgrò, C., Siskind, E. J., Spandre, G., Spinelli, P., Suson, D. J., Tajima, H., Takahashi, M., Tanaka, Y., Thayer, J. B., Thompson, D. J., Tibaldo, L., Torres, D. F., Torresi, E., Tosti, G., Troja, E., Valverde, J., Vianello, G., Vogel, M., Wood, K., Wood, M., Zaharijas, G., Ahnen, M. L., Ansoldi, S., Antonelli, L. A., Arcaro, C., Baack, D., Babić, A., Banerjee, B., Bangale, P., Barres de Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Berti, A., Bhattacharyya, W., Biland, A., Blanch, O., Bonnoli, G., Carosi, A., Carosi, R., Ceribella, G., Chatterjee, A., Colak, S. M., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Cumani, P., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Di Pierro, F., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Elsaesser, D., Fallah Ramazani, V., Fernández-Barral, A., Fidalgo, D., Foffano, L., Pfrang, K., Fonseca, M. V., Font, L., Franceschini, A., Fruck, C., Galindo, D., Gallozzi, S., García López, R. J., Garczarczyk, M., Gaug, M., Giammaria, P., Godinović, N., Gora, D., Guberman, D., Hadasch, D., Hahn, A., Hassan, T., Herrera, J., Hose, J., Hrupec, D., Inoue, S., Ishio, K., Konno, Y., Kubo, H., Kushida, J., Lelas, D., Lindfors, E., Lombardi, S., López, M., Maggio, C., Majumdar, P., Makariev, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Masuda, S., Mazin, D., Minev, M., M, J. M., Mirzoyan, R., Moralejo, A., Moreno, V., Moretti, E., Nagayoshi, T., Neustroev, V., Niedzwiecki, A., Nievas, Rosillo, M., Nigro, Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Paiano, S., Palacio, J., Paneque, D., Paoletti, R., Paredes, J. M., Pedaletti, G., Peresano, M., Prada Moroni, P. G., Prandini, E., Puljak, I., Rodriguez Garcia, J., Reichardt, I., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saito, T., Schweizer, T., Sitarek, J., Šnidarić, I., Sobczynska, D., Stamerra, A., Strzys, M., Surić, T., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Torres-Albà, N., Treves, A., Tsujimoto, S., Vanzo, G., Vazquez Acosta, M., Vovk, I., Ward, J. E., Will, M., Zarić, D., Lucarelli, F., Tavani, M., Piano, G., Donnarumma, I., Pittori, C., Verrecchia, F., Bulgarelli, A., Caraveo, P., Cattaneo, P. W., Colafrancesco, S., Costa, E., Di Cocco, G., Ferrari, A., Gianotti, F., Giuliani, A., Lipari, P., Mereghetti, S., Pacciani, L., Paoletti, F., Parmiggiani, N., Pellizzoni, A., Picozza, P., Pilia, M., Rappoldi, A., Trois, A., Vercellone, S., Vittorini, V., Stanek, K. Z., Kochanek, C. S., Beacom, J. F., Thompson, T. A., Holoien, T. W. -S., Dong, S., Prieto, J. L., Shappee, B. J., Holmbo, S., Abeysekara, A. U., Albert, A., Alfaro, R., Alvarez, C., Arceo, R., Arteaga-Velázquez, J. C., Avila Rojas, D., Ayala Solares, H. A., Becerril, A., Belmont-Moreno, E., Bernal, A., Caballero-Mora, K. S., Capistrán, T., Carramiñana, A., Casanova, S., Castillo, M., Cotti, U., Cotzomi, J., Coutiño de León, S., De León, C., De la Fuente, E., Diaz Hernandez, R., Dichiara, S., Dingus, B. L., Duvernois, M. A., Ellsworth, R. W., Engel, K., Fiorino, D. W., Fleischhack, H., Fraija, N., García-González, J. A., Garfias, F., González Muñoz, A., González, M. M., Goodman, J. A., Hampel-Arias, Z., Harding, J. P., Hernandez, S., Hona, B., Hueyotl-Zahuantitla, F., Hui, C. M., Hüntemeyer, P., Iriarte, A., Jardin-Blicq, A., Joshi, V., Kaufmann, S., Kunde, G. J., Lara, A., Lauer, R. J., Lee, W. H., Lennarz, D., León Vargas, H., Linnemann, J. T., Longinotti, A. L., Luis-Raya, G., Luna-García, R., Malone, K., Marinelli, S. S., Martinez, O., Martinez-Castellanos, I., Martínez-Castro, J., Martínez-Huerta, H., Matthews, J. A., Miranda-Romagnoli, P., Moreno, E., Mostafá, M., Nayerhoda, A., Nellen, L., Newbold, M., Nisa, M. U., Noriega-Papaqui, R., Pelayo, R., Pretz, J., Pérez-Pérez, E. G., Ren, Z., Rho, C. D., Rivière, C., Rosa-González, D., Rosenberg, M., Ruiz-Velasco, E., Salesa Greus, F., Sandoval, A., Schneider, M., Schoorlemmer, H., Sinnis, G., Smith, A. J., Springer, R. W., Surajbali, P., Tibolla, O., Tollefson, K., Torres, I., Villaseñor, L., Weisgarber, T., Werner, F., Yapici, T., Gaurang, Y., Zepeda, A., Zhou, H., Álvarez, J. D., Abdalla, H., Angüner, E. O., Armand, C., Backes, M., Becherini, Y., Berge, D., Böttcher, M., Boisson, C., Bolmont, J., Bonnefoy, S., Bordas, P., Brun, F., Büchele, M., Bulik, T., Caroff, S., Cerruti, M., Chakraborty, N., Chandra, S., Chen, A., Davids, I. D., Deil, C., Devin, J., Djannati-Ataï, A., Egberts, K., Emery, G., Eschbach, S., Fiasson, A., Fontaine, G., Füßling, M., Gallant, Y. A., Gaté, F., Giavitto, G., Glawion, D., Glicenstein, J. F., Gottschall, D., Haupt, M., Henri, G., Hinton, J. A., Hoischen, C., Holch, T. L., Huber, D., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jouvin, L., Jung-Richardt, I., Kerszberg, D., Khélifi, B., King, J., Klepser, S., Kluźniak, W., Komin, Nu., Kraus, M., Lefaucheur, J., Lemière, A., Lenain, J. -P., Leser, E., Lohse, T., López-Coto, R., Lorentz, M., Lypova, I., Marandon, V., Guillem Martí-Devesa, G., Maurin, G., Mitchell, A. M. W., Moderski, R., Mohamed, M., Mohrmann, L., Moulin, E., Murach, T., de Naurois, M., Niederwanger, F., Niemiec, J., Oakes, L., O’Brien, P., Ohm, S., Ostrowski, M., Oya, I., Panter, M., Parsons, R. D., Perennes, C., Piel, Q., Pita, S., Poireau, V., Priyana Noel, A., Prokoph, H., Pühlhofer, G., Quirrenbach, A., Raab, S., Rauth, R., Renaud, M., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Sanchez, D. A., Sasaki, M., Schlickeiser, R., Schüssler, F., Schulz, A., Schwanke, U., Seglar-Arroyo, M., Shafi, N., Simoni, R., Sol, H., Stegmann, C., Steppa, C., Tavernier, T., Taylor, A. M., Tiziani, D., Trichard, C., Tsirou, M., van Eldik, C., van Rensburg, C., van Soelen, B., Veh, J., Vincent, P., Voisin, F., Wagner, S. J., Wagner, R. M., Wierzcholska, A., Zanin, R., Zdziarski, A. A., Zech, A., Ziegler, A., Zorn, J., Żywucka, N., Savchenko, V., Ferrigno, C., Bazzano, A., Diehl, R., Kuulkers, E., Laurent, P., Natalucci, L., Panessa, F., Rodi, J., Ubertini, P., Morokuma, T., Ohta, K., Tanaka, Y. T., Mori, H., Yamanaka, M., Kawabata, K. S., Utsumi, Y., Nakaoka, T., Kawabata, M., Nagashima, H., Yoshida, M., Matsuoka, Y., Itoh, R., Keel, W., Copperwheat, C., Steele, I., Cenko, S. B., Evans, P. A., Fox, D. B., Kennea, J. A., Marshall, F. E., Osborne, J. P., Tohuvavohu, A., Archer, A., Benbow, W., Bird, R., Brill, A., Brose, R., Buchovecky, M., Buckley, J. H., Bugaev, V., Christiansen, J. L., Connolly, M. P., Cui, W., Daniel, M. K., Errando, M., Falcone, A., Feng, Q., Finley, J. P., Fortson, L., Furniss, A., Gueta, O., Hütten, M., Hervet, O., Hughes, G., Humensky, T. B., Johnson, C. A., Kaaret, P., Kar, P., Kelley-Hoskins, N., Kertzman, M., Kieda, D., Krause, M., Krennrich, F., Kumar, S., Lang, M. J., Lin, T. T. Y., Maier, G., Mcarthur, S., Moriarty, P., Mukherjee, R., Nieto, D., O’Brien, S., Ong, R. A., Otte, A. N., Park, N., Petrashyk, A., Pohl, M., Popkow, A., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Richards, G. T., Roache, E., Rulten, C., Sadeh, I., Scott, S. S., Sembroski, G. H., Shahinyan, K., Sushch, I., Trépanier, S., Tyler, J., Vassiliev, V. V., Wakely, S. P., Weinstein, A., Wells, R. M., Wilcox, P., Wilhelm, A., Williams, D. A., Zitzer, B., Tetarenko, A. J., Kimball, A. E., Miller-Jones, J. C. A., Sivakoff, G. R., Physics, Elementary Particle Physics, Vriendenkring VUB, Faculty of Sciences and Bioengineering Sciences, Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Annecy de Physique des Particules (LAPP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), Współautorami artykułu są członkowie różnych grup badawczych w liczbie 875, Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)
Subjects: High energy, Kanata, Swift/NuSTAR, Astrophysics, Blazar, blazar: emission, 01 natural sciences, 7. Clean energy, Coincidence, Multidisciplinary, Blazar, Neutrino, High Energy Physics - Experiment, neutrino, High Energy Physics - Experiment (hep-ex), ASAS-SN, 010303 astronomy & astrophysics, HESS - Abteilung Hofmann, Computer Science::Databases, Physics, HAWC - Abteilung Hinton, High Energy Astrophysical Phenomena (astro-ph.HE), COSMIC cancer database, Multidisciplinary, Supernova, gamma ray: emission, VERITAS, Neutrino, Kapteyn, Astrophysics - High Energy Astrophysical Phenomena, General Science & Technology, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, IceCube Collaboration, jet: relativistic, AGILE, Coincident, Subaru, 0103 physical sciences, Kiso, supernova, neutrino event IceCube-170922A, gamma-ray blazar TXS 0506+056, quasar, Astrophysics::Galaxy Astrophysics, ta115, 010308 nuclear & particles physics, INTEGRAL, background, Liverpool Telescope, VLA/17B-403 teams, MAGIC, messenger, flux, gamma ray: VHE, 13. Climate action, general, Diffuse flux, High Energy Physics::Experiment, Fermi-LAT, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], HAWC, H.E.S.S
Abstract: INTRODUCTION Neutrinos are tracers of cosmic-ray acceleration: electrically neutral and traveling at nearly the speed of light, they can escape the densest environments and may be traced back to their source of origin. High-energy neutrinos are expected to be produced in blazars: intense extragalactic radio, optical, x-ray, and, in some cases, γ-ray sources characterized by relativistic jets of plasma pointing close to our line of sight. Blazars are among the most powerful objects in the Universe and are widely speculated to be sources of high-energy cosmic rays. These cosmic rays generate high-energy neutrinos and γ-rays, which are produced when the cosmic rays accelerated in the jet interact with nearby gas or photons. On 22 September 2017, the cubic-kilometer IceCube Neutrino Observatory detected a ~290-TeV neutrino from a direction consistent with the flaring γ-ray blazar TXS 0506+056. We report the details of this observation and the results of a multiwavelength follow-up campaign. RATIONALE Multimessenger astronomy aims for globally coordinated observations of cosmic rays, neutrinos, gravitational waves, and electromagnetic radiation across a broad range of wavelengths. The combination is expected to yield crucial information on the mechanisms energizing the most powerful astrophysical sources. That the production of neutrinos is accompanied by electromagnetic radiation from the source favors the chances of a multiwavelength identification. In particular, a measured association of high-energy neutrinos with a flaring source of γ-rays would elucidate the mechanisms and conditions for acceleration of the highest-energy cosmic rays. The discovery of an extraterrestrial diffuse flux of high-energy neutrinos, announced by IceCube in 2013, has characteristic properties that hint at contributions from extragalactic sources, although the individual sources remain as yet unidentified. Continuously monitoring the entire sky for astrophysical neutrinos, IceCube provides real-time triggers for observatories around the world measuring γ-rays, x-rays, optical, radio, and gravitational waves, allowing for the potential identification of even rapidly fading sources. RESULTS A high-energy neutrino-induced muon track was detected on 22 September 2017, automatically generating an alert that was distributed worldwide within 1 min of detection and prompted follow-up searches by telescopes over a broad range of wavelengths. On 28 September 2017, the Fermi Large Area Telescope Collaboration reported that the direction of the neutrino was coincident with a cataloged γ-ray source, 0.1° from the neutrino direction. The source, a blazar known as TXS 0506+056 at a measured redshift of 0.34, was in a flaring state at the time with enhanced γ-ray activity in the GeV range. Follow-up observations by imaging atmospheric Cherenkov telescopes, notably the Major Atmospheric Gamma Imaging Cherenkov (MAGIC) telescopes, revealed periods where the detected γ-ray flux from the blazar reached energies up to 400 GeV. Measurements of the source have also been completed at x-ray, optical, and radio wavelengths. We have investigated models associating neutrino and γ-ray production and find that correlation of the neutrino with the flare of TXS 0506+056 is statistically significant at the level of 3 standard deviations (sigma). On the basis of the redshift of TXS 0506+056, we derive constraints for the muon-neutrino luminosity for this source and find them to be similar to the luminosity observed in γ-rays. CONCLUSION The energies of the γ-rays and the neutrino indicate that blazar jets may accelerate cosmic rays to at least several PeV. The observed association of a high-energy neutrino with a blazar during a period of enhanced γ-ray emission suggests that blazars may indeed be one of the long-sought sources of very-high-energy cosmic rays, and hence responsible for a sizable fraction of the cosmic neutrino flux observed by IceCube.
Published: 2018
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37. Gamma-ray observations of Tycho's SNR with VERITAS and Fermi

Author: VERITAS Collaboration, Archambault, S., Archer, A., Benbow, W., Bird, R., Bourbeau, E., Buchovecky, M., Buckley, J. H., Bugaev, V., Cerruti, M., Connolly, M. P., Cui, W., Dwarkadas, V. V., Errando, M., Falcone, A., Feng, Q., Finley, J. P., Fleischhack, H., Fortson, L., Furniss, A., Griffin, S., Hutten, M., Hanna, D., Holder, J., Johnson, C. A., Kaaret, P., Kar, P., Kelley-Hoskins, N., Kertzman, M., Kieda, D., Krause, M., Kumar, S., Lang, M. J., Maier, G., McArthur, S., McCann, A., Moriarty, P., Mukherjee, R., Nieto, D., O'Brien, S., Ong, R. A., Otte, A. N., Park, N., Pohl, M., Popkow, A., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Richards, G. T., Roache, E., Sadeh, I., Santander, M., Sembroski, G. H., Shahinyan, K., Slane, P., Staszak, D., Telezhinsky, I., Trepanier, S., Tyler, J., Wakely, S. P., Weinstein, A., Weisgarber, T., Wilcox, P., Wilhelm, A., Williams, D. A., and Zitzer, B.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics - High Energy Astrophysical Phenomena
Abstract: High-energy gamma-ray emission from supernova remnants (SNRs) has provided a unique perspective for studies of Galactic cosmic-ray acceleration. Tycho's SNR is a particularly good target because it is a young, type Ia SNR that is well-studied over a wide range of energies and located in a relatively clean environment. Since the detection of gamma-ray emission from Tycho's SNR by VERITAS and Fermi-LAT, there have been several theoretical models proposed to explain its broadband emission and high-energy morphology. We report on an update to the gamma-ray measurements of Tycho's SNR with 147 hours of VERITAS and 84 months of Fermi-LAT observations, which represents about a factor of two increase in exposure over previously published data. About half of the VERITAS data benefited from a camera upgrade, which has made it possible to extend the TeV measurements toward lower energies. The TeV spectral index measured by VERITAS is consistent with previous results, but the expanded energy range softens a straight power-law fit. At energies higher than 400 GeV, the power-law index is $2.92 \pm 0.42_{\mathrm{stat}} \pm 0.20_{\mathrm{sys}}$. It is also softer than the spectral index in the GeV energy range, $2.14 \pm 0.09_{\mathrm{stat}} \pm 0.02_{\mathrm{sys}}$, measured by this study using Fermi--LAT data. The centroid position of the gamma-ray emission is coincident with the center of the remnant, as well as with the centroid measurement of Fermi--LAT above 1 GeV. The results are consistent with an SNR shell origin of the emission, as many models assume. The updated spectrum points to a lower maximum particle energy than has been suggested previously., Accepted for publication in The Astrophysical Journal
Published: 2017

38. Very-High-Energy $��$-Ray Observations of the Blazar 1ES 2344+514 with VERITAS

Author: Allen, C., Archambault, S., Archer, A., Benbow, W., Bird, R., Bourbeau, E., Brose, R., Buchovecky, M., Buckley, J. H., Bugaev, V., Cardenzana, J. V, Cerruti, M., Chen, X., Christiansen, J. L., Connolly, M. P., Cui, W., Daniel, M. K., Eisch, J. D., Falcone, A., Feng, Q., Fernandez-Alonso, M., Finley, J. P., Fleischhack, H., Flinders, A., Fortson, L., Furniss, A., Gillanders, G. H., Griffin, S., Grube, J., H��tten, M., H��kansson, N., Hanna, D., Hervet, O., Holder, J., Hughes, G., Humensky, T. B., Johnson, C. A., Kaaret, P., Kar, P., Kelley-Hoskins, N., Kertzman, M., Kieda, D., Krause, M., Krennrich, F., Kumar, S., Lang, M. J., Maier, G., McArthur, S., McCann, A., Meagher, K., Moriarty, P., Mukherjee, R., Nguyen, T., Nieto, D., O'Brien, S., de Bhr��ithe, A. O'Faol��in, Ong, R. A., Otte, A. N., Park, N., Petrashyk, A., Pichel, A., Pohl, M., Popkow, A., 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., Telezhinsky, I., Tucci, J. V., Tyler, J., Wakely, S. P., Weinstein, A., Wilhelm, A., and Williams, D. A.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), FOS: Physical sciences
Abstract: We present very-high-energy $��$-ray observations of the BL Lac object 1ES 2344+514 taken by the Very Energetic Radiation Imaging Telescope Array System (VERITAS) between 2007 and 2015. 1ES 2344+514 is detected with a statistical significance above background of $20.8��$ in $47.2$ hours (livetime) of observations, making this the most comprehensive very-high-energy study of 1ES 2344+514 to date. Using these observations the temporal properties of 1ES 2344+514 are studied on short and long times scales. We fit a constant flux model to nightly- and seasonally-binned light curves and apply a fractional variability test, to determine the stability of the source on different timescales. We reject the constant-flux model for the 2007-2008 and 2014-2015 nightly-binned light curves and for the long-term seasonally-binned light curve at the $> 3��$ level. The spectra of the time-averaged emission before and after correction for attenuation by the extragalactic background light are obtained. The observed time-averaged spectrum above 200 GeV is satisfactorily fitted (${��^2/NDF = 7.89/6}$) by a power-law function with index $��= 2.46 \pm 0.06_{stat} \pm 0.20_{sys} $ and extends to at least 8 TeV. The extragalactic-background-light-deabsorbed spectrum is adequately fit (${��^2/NDF = 6.73/6}$) by a power-law function with index $��= 2.15 \pm 0.06_{stat} \pm 0.20_{sys} $ while an F-test indicates that the power-law with exponential cutoff function provides a marginally-better fit ($��^2/NDF $ = $2.56 / 5 $) at the 2.1$��$ level. The source location is found to be consistent with the published radio location and its spatial extent is consistent with a point source., 7 pages, 2 figures. Published in Monthly Notices of the Royal Astronomical Society
Published: 2017
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39. A luminous and isolated gamma-ray flare from the blazar B2 1215+30

Author: Veritas, Collaboration, Abeysekara, A. U., Archambault, S., Archer, A., Benbow, W., Bird, R., Buchovecky, M., Buckley, J. H., Bugaev, V., Byrum, K., Cerruti, M., Chen, X., Ciupik, L., Cui, W., Dickinson, H. J., Eisch, J. D., Errando, M., Falcone, A., Feng, Q., Finley, J. P., Fleischhack, H., Fortson, L., Furniss, A., Gillanders, G. H., Griffin, S., Grube, J., Hutten, M., Hakansson, N., Hanna, D., Holder, J., Humensky, T. B., Johnson, C. A., Kaaret, P., Kar, P., Kertzman, M., Kieda, D., Krause, M., Krennrich, F., Kumar, S., Lang, M. J., Gernot Maier, Mcarthur, S., Mccann, A., Meagher, K., Moriarty, P., Mukherjee, R., Nguyen, T., Nieto, D., Ong, R. A., Otte, A. N., Park, N., Pelassa, V., Pohl, M., Popkow, A., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Richards, G. T., Roache, E., Rulten, C., Santander, M., Sembroski, G. H., Shahinyan, K., Staszak, D., Telezhinsky, I., Tucci, J. V., Tyler, J., Wakely, S. P., Weiner, O. M., Weinstein, A., Wilhelm, A., Williams, D. A., Fermi-LAT Collaboration, Fegan, S., Giebels, B., Horan, D., Berdyugin, A., Kuan, J., Lindfors, E., Nilsson, K., Oksanen, A., Prokoph, H., Reinthal, R., Takalo, L., Zefi, F., AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), VERITAS, Fermi-LAT, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), AstroParticule et Cosmologie ( APC - UMR 7164 ), Centre National de la Recherche Scientifique ( CNRS ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Observatoire de Paris-Université Paris Diderot - Paris 7 ( UPD7 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ), Laboratoire Leprince-Ringuet ( LLR ), Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -École polytechnique ( X ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Physique Nucléaire et de Hautes Énergies ( LPNHE ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Université Paris Diderot - Paris 7 ( UPD7 ) -Centre National de la Recherche Scientifique ( CNRS ), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: multiwavelength observations, 010504 meteorology & atmospheric sciences, [ PHYS.ASTR ] Physics [physics]/Astrophysics [astro-ph], Astrophysics::High Energy Astrophysical Phenomena, galaxies: active, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, swift ultraviolet/optical telescope, 01 natural sciences, law.invention, bl lacertae objects, law, Observatory, 0103 physical sciences, gamma rays: galaxies, Astrophysics::Solar and Stellar Astrophysics, ddc:530, MAGIC (telescope), Blazar, 010303 astronomy & astrophysics, Cherenkov radiation, 0105 earth and related environmental sciences, BL Lacertae objects: individual, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Spectral index, particle-acceleration, Astrophysics::Instrumentation and Methods for Astrophysics, Gamma ray, Institut für Physik und Astronomie, Astronomy and Astrophysics, source catalog, galaxies: jets, spectral energy-distributions, bl lacertae objects: individual (b2 1215+30, ver j1217+301), large-area telescope, Crab Nebula, Space and Planetary Science, active galactic nuclei, reconnection, ddc:520, galaxies: nuclei, Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], discovery, Flare
Abstract: The astrophysical journal 836(2), 205 (2017). doi:10.3847/1538-4357/836/2/205, B2 1215+30 is a BL-Lac-type blazar that was first detected at TeV energies by the MAGIC atmospheric Cherenkov telescopes and subsequently confirmed by the Very Energetic Radiation Imaging Telescope Array System (VERITAS) observatory with data collected between 2009 and 2012. In 2014 February 08, VERITAS detected a large-amplitude flare from B2 1215+30 during routine monitoring observations of the blazar 1ES 1218+304, located in the same field of view. The TeV flux reached 2.4 times the Crab Nebula flux with a variability timescale of $\lt 3.6\,\mathrm{hr}$. Multiwavelength observations with Fermi-LAT, Swift, and the Tuorla Observatory revealed a correlated high GeV flux state and no significant optical counterpart to the flare, with a spectral energy distribution where the gamma-ray luminosity exceeds the synchrotron luminosity. When interpreted in the framework of a one-zone leptonic model, the observed emission implies a high degree of beaming, with Doppler factor $\delta \gt 10$, and an electron population with spectral index $p\lt 2.3$., Published by IOP Publ., Chicago, Ill. [u.a.]
Published: 2017
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40. Search for Magnetically Broadened Cascade Emission From Blazars with VERITAS

Author: Veritas, Collaboration, Archambault, S., Archer, A., Benbow, W., Buchovecky, M., Bugaev, V., Cerruti, M., Connolly, M. P., Cui, W., Falcone, A., Fernández Alonso, M., Finley, J. P., Fleischhack, H., Fortson, L., Furniss, A., Griffin, S., Hütten, M., Hervet, O., Holder, J., Humensky, T. B., Johnson, C. A., Kaaret, P., Kar, P., Kieda, D., Krause, M., Krennrich, F., Lang, M. J., Lin, T. T. Y., Gernot Maier, Mcarthur, S., Moriarty, P., Nieto, D., O Brien, S., Ong, R. A., Otte, A. N., Pohl, M., Popkow, A., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Richards, G. T., Roache, E., Rovero, A. C., Sadeh, I., Shahinyan, K., Staszak, D., Telezhinsky, I., Tyler, J., Wakely, S. P., Weinstein, A., Weisgarber, T., Wilcox, P., Wilhelm, A., Williams, D. A., and Zitzer, B.
Subjects: extragalactic background light, Photon, GALAXIES [GAMMA RAYS], Ciencias Físicas, Cosmic microwave background, Astrophysics, magnetic fields, 7. Clean energy, 01 natural sciences, purl.org/becyt/ford/1 [https], pair halos, 010303 astronomy & astrophysics, ACTIVE [GALAXIES], fields, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Gamma ray, cosmic voids, universe, large-area telescope, Extragalactic background light, Cascade, ddc:53, GENERAL [BL LACERTAE OBJECTS], Astrophysics - High Energy Astrophysical Phenomena, CIENCIAS NATURALES Y EXACTAS, Active galactic nucleus, Astrophysics::High Energy Astrophysical Phenomena, galaxies: active, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, gamma rays: galaxies, 0103 physical sciences, 010306 general physics, Blazar, Astrophysics::Galaxy Astrophysics, bl lacertae objects: general, gamma-ray observations, tev blazars, Institut für Physik und Astronomie, Astronomy and Astrophysics, purl.org/becyt/ford/1.3 [https], MAGNETIC FIELDS, radiation, Astronomía, 13. Climate action, Space and Planetary Science, active galactic nuclei, ddc:520, Intergalactic travel
Abstract: We present a search for magnetically broadened gamma-ray emission around active galactic nuclei (AGN), using VERITAS observations of seven hard-spectrum blazars. A cascade process occurs when multi-TeV gamma rays from AGN interact with extragalactic background light (EBL) photons to produce electron-positron pairs, which then interact with cosmic microwave background (CMB) photons via inverse-Compton scattering to produce gamma rays. Due to the deflection of the electron-positron pairs, a non-zero intergalactic magnetic field (IGMF) would potentially produce detectable effects on the angular distribution of the cascade emission. In particular, an angular broadening compared to the unscattered emission could occur. Through non-detection of angularly broadened emission from 1ES 1218+304, the source with the largest predicted cascade fraction, we exclude a range of IGMF strengths around $10^{-14}$G at the 95% confidence level. The extent of the exclusion range varies with the assumptions made about the intrinsic spectrum of 1ES 1218+304 and the EBL model used in the simulation of the cascade process. All of the sources are used to set limits on the flux due to extended emission., Comment: Accepted for publication in The Astrophysical Journal
Published: 2017
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41. VERITAS contributions to the 35th International Cosmic Ray Conference

Author: Abeysekara, A. U., Archambault, S., Archer, A., Benbow, W., Bird, R., Brose, R., Buchovecky, M., Christiansen, J. L., Connolly, M. P., Cui, W., Daniel, M. K., Falcone, A., Feng, Q., Fernandez-Alonso, M., Finley, J. P., Fleischhack, H., Fortson, L., Furniss, A., Gillanders, G. H., Hütten, M., Hanna, D., Hervet, O., Holder, J., Hughes, G., Humensky, T. B., Johnson, C. A., Kaaret, P., Kar, P., Kertzman, M., Kieda, D., Krause, M., Krennrich, F., Kumar, S., Lang, M. J., Maier, G., Mcarthur, S., Moriarty, P., Mukherjee, R., Nieto, D., O Brien, S., Ong, R. A., Otte, A. N., Pandel, D., Park, N., Pohl, M., Popkow, A., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Roache, E., Rovero, A. C., Sadeh, I., Juan Marcos Santander, Schlenstedt, S., Sembroski, G. H., Shahinyan, K., Tyler, J., Wakely, S. P., Weinstein, A., Wells, R. M., Wilcox, P., Wilhelm, A., Williams, D. A., Williamson, T. J., and Zitzer, B.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), FOS: Physical sciences, Astrophysics - High Energy Astrophysical Phenomena
Abstract: Compilation of papers presented by the VERITAS Collaboration at the 35th International Cosmic Ray Conference (ICRC), held July 12 through July 20, 2017 in Busan, South Korea., Comment: html page. 2017 ICRC, Busan, South Korea. A full list of author affiliations can be found at this link: https://veritas.sao.arizona.edu/conferences/ICRC2017_AuthList.html
Published: 2017
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42. Multiwavelength follow-up of a rare IceCube neutrino multiplet

Author: Aartsen, M. G., Ackermann, M., Adams, J., Aguilar, J. A., Ahlers, M., Ahrens, M., Samarai, I. Al, Altmann, D., Andeen, K., Anderson, T., Ansseau, I., Anton, G., Archinger, M., Arg��elles, C., Auffenberg, J., Axani, S., Bai, X., Barwick, S. W., Baum, V., Bay, R., Beatty, J. J., Tjus, J. Becker, Becker, K. -H., BenZvi, S., Berley, D., Bernardini, E., Bernhard, A., Besson, D. Z., Binder, G., Bindig, D., Blaufuss, E., Blot, S., Bohm, C., B��rner, M., Bos, F., Bose, D., B��ser, S., Botner, O., Braun, J., Brayeur, L., Bretz, H. -P., Bron, S., Burgman, A., Carver, T., Casier, M., Cheung, E., Chirkin, D., Christov, A., Clark, K., Classen, L., Coenders, S., Collin, G. H., Conrad, J. M., Cowen, D. F., Cross, R., Day, M., de, J. P. A. M., R��, De Clercq, C., Rosendo, E. del Pino, Dembinski, H., De Ridder, S., Desiati, P., de Vries, K. D., de Wasseige, G., de With, M., DeYoung, T., di Lorenzo, V., Dujmovic, H., Dumm, J. P., Dunkman, M., Eberhardt, B., Ehrhardt, T., Eichmann, B., Eller, P., Euler, S., Evenson, P. A., Fahey, S., Fazely, A. R., Feintzeig, J., Felde, J., Filimonov, K., Finley, C., Flis, S., F��sig, C. -C., Franckowiak, A., Friedman, E., Fuchs, T., Gaisser, T. K., Gallagher, J., Gerhardt, L., Ghorbani, K., Giang, W., Gladstone, L., Glauch, T., Gl��senkamp, T., Goldschmidt, A., Gonzalez, J. G., Grant, D., Griffith, Z., Haack, C., Hallgren, A., Halzen, F., Hansen, E., Hansmann, T., Hanson, K., Hebecker, D., Heereman, D., Helbing, K., Hellauer, R., Hickford, S., Hignight, J., Hill, G. C., Hoffman, K. D., Hoffmann, R., Hoshina, K., Huang, F., Huber, M., Hultqvist, K., In, S., Ishihara, A., Jacobi, E., Japaridze, G. S., Jeong, M., Jero, K., Jones, B. J. P., Kang, W., Kappes, A., Karg, T., Karle, A., Katz, U., Kauer, M., Keivani, A., Kelley, J. L., Kheirandish, A., Kim, J., Kim, M., Kintscher, T., Kiryluk, J., Kittler, T., Klein, S. R., Kohnen, G., Koirala, R., Kolanoski, H., Konietz, R., K��pke, L., Kopper, C., Kopper, S., Koskinen, D. J., Kowalski, M., Krings, K., Kroll, M., Kr��ckl, G., Kr��ger, C., Kunnen, J., Kunwar, S., Kurahashi, N., Kuwabara, T., Kyriacou, A., Labare, M., Lanfranchi, J. L., Larson, M. J., Lauber, F., Lesiak-Bzdak, M., Leuermann, M., Lu, L., L��nemann, J., Madsen, J., Maggi, G., Mahn, K. B. M., Mancina, S., Mandelartz, M., Maruyama, R., Mase, K., Maunu, R., McNally, F., Meagher, K., Medici, M., Meier, M., Menne, T., Merino, G., Meures, T., Miarecki, S., Micallef, J., Moment��, G., Montaruli, T., Moulai, M., Nahnhauer, R., Naumann, U., Neer, G., Niederhausen, H., Nowicki, S. C., Nygren, D. R., Pollmann, A. Obertacke, Olivas, A., O'Murchadha, A., Palczewski, T., Pandya, H., Pankova, D. V., Peiffer, P., Penek, ��., Pepper, J. A., Heros, C. P��rez de los, Pieloth, D., Pinat, E., Price, P. B., Przybylski, G. T., Quinnan, M., Raab, C., R��del, L., Rameez, M., Rawlins, K., Reimann, R., Relethford, B., Relich, M., Resconi, E., Rhode, W., Richman, M., Riedel, B., Robertson, S., Rongen, M., Rott, C., Ruhe, T., Ryckbosch, D., Rysewyk, D., Sabbatini, L., Herrera, S. E. Sanchez, Sandrock, A., Sandroos, J., Sarkar, S., Satalecka, K., Schlunder, P., Schmidt, T., Schoenen, S., Sch��neberg, S., Schumacher, L., Seckel, D., Seunarine, S., Soldin, D., Song, M., Spiczak, G. M., Spiering, C., Stachurska, J., Stanev, T., Stasik, A., Stettner, J., Steuer, A., Stezelberger, T., Stokstad, R. G., St��l, A., Str��m, R., Strotjohann, N. L., Sullivan, G. W., Sutherland, M., Taavola, H., Taboada, I., Tatar, J., Tenholt, F., Ter-Antonyan, S., Terliuk, A., Te��i��, G., Tilav, S., Toale, P. A., Tobin, M. N., Toscano, S., Tosi, D., Tselengidou, M., Tung, C. F., Turcati, A., Unger, E., Usner, M., Vandenbroucke, J., van Eijndhoven, N., Vanheule, S., van Rossem, M., van Santen, J., Vehring, M., Voge, M., Vogel, E., Vraeghe, M., Walck, C., Wallace, A., Wallraff, M., Wandkowsky, N., Waza, A., Weaver, Ch., Weiss, M. J., Wendt, C., Westerhoff, S., Whelan, B. J., Wickmann, S., Wiebe, K., Wiebusch, C. H., Wille, L., Williams, D. R., Wills, L., Wolf, M., Wood, T. R., Woolsey, E., Woschnagg, K., Xu, D. L., Xu, X. W., Xu, Y., Yanez, J. P., Yodh, G., Yoshida, S., Zoll, M., Stanek, K. Z., Shappee, B. J., Kochanek, C. S., Holoien, T. W. -S., Prieto, J. L., Fox, D. B., DeLaunay, J. J., Turley, C. F., Barthelmy, S. D., Lien, A. Y., M��sz��ros, P., Murase, K., Kocevski, D., Buehler, R., Giomi, M., Racusin, J. L., Albert, A., Alfaro, R., Alvarez, C., ��lvarez, J. D., Arceo, R., Arteaga-Vel��zquez, J. C., Solares, H. A. Ayala, Barber, A. S., Becerril, N. Baustista-Elivar A., Belmont-Moreno, E., Bernal, A., Brisbois, C., Caballero-Mora, K. S., Capistr��n, T., Carrami��ana, A., Casanova, S., Castillo, M., Cotti, U., de Le��n, S. Couti��o, de la Fuente, E., De Le��n, C., Hernandez, R. Diaz, D��az-V��lez, J. C., Dingus, B. L., DuVernois, M. A., Ellsworth, R. W., Engel, K., Fiorino, D. W., Fraija, N., Garc��a-Gonz��lez, J. A., Gerhardt, M., Mu��oz, A. Gonz��lez, Gonz��lez, M. M., Goodman, J. A., Hampel-Arias, Z., Harding, J. P., Hernandez, S., Hui, C. M., H��ntemeyer, P., Iriarte, A., Jardin-Blicq, A., Joshi, V., Kaufmann, S., Lara, A., Lauer, R. J., Lee, W. H., Lennarz, D., Vargas, H. Le��n, Linnemann, J. T., Raya, G. Luis, Luna-Garc��a, R., L��pez-Coto, R., Malone, K., Marinelli, S. S., Martinez, O., Martinez-Castellanos, I., Mart��nez-Castro, J., Mart��nez-Huerta, H., Matthews, J. A., Miranda-Romagnoli, P., Moreno, E., Mostaf��, M., Nellen, L., Newbold, M., Nisa, M. U., Noriega-Papaqui, R., Pelayo, R., Pretz, J., P��rez-P��rez, E. G., Ren, Z., Rho, C. D., Rivi��re, C., Rosa-Gonz��lez, D., Rosenberg, M., Greus, F. Salesa, Sandoval, A., Schneider, M., Schoorlemmer, H., Sinnis, G., Smith, A. J., Springer, R. W., Surajbali, P., Tibolla, O., Tollefson, K., Torres, I., Ukwatta, T. N., Villase��or, L., Weisgarber, T., Wisher, I. G., Wood, J., Yapici, T., Zepeda, A., Zhou, H., Arcavi, I., Hosseinzadeh, G., Howell, D. A., Valenti, S., McCully, C., Lipunov, V. M., Gorbovskoy, E. S., Tiurina, N. V., Balanutsa, P. V., Kuznetsov, A. S., Kornilov, V. G., Chazov, V., Budnev, N. M., Gress, O. A., Ivanov, K. I., Tlatov, A. G., Lopez, R. Rebolo, Serra-Ricart, M., Evans, P. A., Kennea, J. A., Gehrels, N., Osborne, J. P., Page, K. L., Abeysekara, A. U., Archer, A., Benbow, W., Bird, R., Brantseg, T., Bugaev, V., Cardenzana, J. V, Connolly, M. P., Cui, W., Falcone, A., Feng, Q., Finley, J. P., Fleischhack, H., Fortson, L., Furniss, A., Griffin, S., Grube, J., H��tten, M., Hervet, O., Holder, J., Hughes, G., Humensky, T. B., Johnson, C. A., Kaaret, P., Kar, P., Kelley-Hoskins, N., Kertzman, M., Krause, M., Kumar, S., Lang, M. J., Lin, T. T. Y., McArthur, S., Moriarty, P., Mukherjee, R., Nieto, D., Ong, R. A., Otte, A. N., Pohl, M., Popkow, A., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Richards, G. T., Roache, E., Rulten, C., Sadeh, I., Santander, M., Sembroski, G. H., Staszak, D., Tr��panier, S., Tyler, J., Wakely, S. P., Weinstein, A., Wilcox, P., Wilhelm, A., Williams, D. A., Zitzer, B., Bellm, E., Cano, Z., Gal-Yam, A., Kann, D. A., Ofek, E. O., Rigault, M., Soumagnac, M., National Science Foundation (US), Consejo Nacional de Ciencia y Tecnología (México), Universidad Nacional Autónoma de México, National Aeronautics and Space Administration (US), Villum Fonden, UK Space Agency, Physics, Elementary Particle Physics, Faculty of Sciences and Bioengineering Sciences, and Vriendenkring VUB
Subjects: Supernovae: general, Astrophysics, general [gamma-ray burst], 01 natural sciences, 7. Clean energy, LARGE-AREA TELESCOPE, law.invention, law, Observatory, all-sky survey, emission, Muon neutrino, X-rays: bursts, 010303 astronomy & astrophysics, media_common, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), GAMMA-RAY BURSTS, gamma-ray bursts, Gamma-ray burst: general, neutrinos, Galaxies: active, Supernova, large-area telescope, astroparticle physics, ALL-SKY SURVEY, tidal disruption, active [galaxies], Neutrino, Astrophysics - High Energy Astrophysical Phenomena, grb optical afterglows, general [supernovae], alert system, ACTIVE GALACTIC NUCLEI, Active galactic nucleus, bursts [X-rays], TIDAL DISRUPTION, media_common.quotation_subject, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Telescope, 0103 physical sciences, luminosity function, Neutrinos, 010308 nuclear & particles physics, GRB OPTICAL AFTERGLOWS, Astronomy and Astrophysics, Astroparticle physics, Space and Planetary Science, swift-bat survey, Physics and Astronomy, 13. Climate action, Sky, LUMINOSITY FUNCTION, active galactic nuclei, ddc:520, SWIFT-BAT SURVEY, EMISSION, Fermi Gamma-ray Space Telescope, ALERT SYSTEM
Abstract: Full list of authors: Aartsen, M. G.; Ackermann, M.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Ahrens, M.; Al Samarai, I.; Altmann, D.; Andeen, K.; Anderson, T.; Ansseau, I.; Anton, G.; Archinger, M.; Argüelles, C.; Auffenberg, J.; Axani, S.; Bai, X.; Barwick, S. W.; Baum, V. Bay, R.; Beatty, J. J.; Tjus, J. Becker; Becker, K. -H.; Benzvi, S.; Berley, D.; Bernardini, E.; Bernhard, A.; Besson, D. Z.; Binder, G.; Bindig, D.; Blaufuss, E.; Blot, S.; Bohm, C.; Börner, M.; Bos, F.; Bose, D.; Böser, S.; Botner, O.; Braun, J.; Brayeur, L.; Bretz, H. -P.; Bron, S.; Burgman, A.; Carver, T.; Casier, M.; Cheung, E.; Chirkin, D.; Christov, A.; Clark, K.; Classen, L.; Coenders, S.; Collin, G. H.; Conrad, J. M.; Cowen, D. F.; Cross, R.; Day, M.; de André, J. P. A. M.; de Clercq, C.; Del Pino Rosendo, E.; Dembinski, H.; De Ridder, S.; Desiati, P.; de Vries, K. D.; de Wasseige, G.; de With, M.; Deyoung, T.; di Lorenzo, V.; Dujmovic, H.; Dumm, J. P.; Dunkman, M.; Eberhardt, B.; Ehrhardt, T.; Eichmann, B.; Eller, P.; Euler, S.; Evenson, P. A.; Fahey, S.; Fazely, A. R.; Feintzeig, J.; Felde, J.; Filimonov, K.; Finley, C.; Flis, S.; Fösig, C. -C.; Franckowiak, A.; Friedman, E.; Fuchs, T.; Gaisser, T. K.; Gallagher, J.; Gerhardt, L.; Ghorbani, K.; Giang, W.; Gladstone, L.; Glauch, T.; Glüsenkamp, T.; Goldschmidt, A.; Gonzalez, J. G.; Grant, D.; Griffith, Z.; Haack, C.; Hallgren, A.; Halzen, F.; Hansen, E.; Hansmann, T.; Hanson, K.; Hebecker, D.; Heereman, D.; Helbing, K.; Hellauer, R.; Hickford, S.; Hignight, J.; Hill, G. C.; Hoffman, K. D.; Hoffmann, R.; Hoshina, K.; Huang, F.; Huber, M.; Hultqvist, K.; in, S.; Ishihara, A.; Jacobi, E.; Japaridze, G. S.; Jeong, M.; Jero, K.; Jones, B. J. P.; Kang, W.; Kappes, A.; Karg, T.; Karle, A.; Katz, U.; Kauer, M.; Keivani, A.; Kelley, J. L.; Kheirandish, A.; Kim, J.; Kim, M.; Kintscher, T.; Kiryluk, J.; Kittler, T.; Klein, S. R.; Kohnen, G.; Koirala, R.; Kolanoski, H.; Konietz, R.; Köpke, L.; Kopper, C.; Kopper, S.; Koskinen, D. J.; Kowalski, M.; Krings, K.; Kroll, M.; Krückl, G.; Krüger, C.; Kunnen, J.; Kunwar, S.; Kurahashi, N.; Kuwabara, T.; Kyriacou, A.; Labare, M.; Lanfranchi, J. L.; Larson, M. J.; Lauber, F.; Lesiak-Bzdak, M.; Leuermann, M.; Lu, L.; Lünemann, J.; Madsen, J.; Maggi, G.; Mahn, K. B. M.; Mancina, S.; Mandelartz, M.; Maruyama, R.; Mase, K.; Maunu, R.; McNally, F.; Meagher, K.; Medici, M.; Meier, M.; Menne, T.; Merino, G.; Meures, T.; Miarecki, S.; Micallef, J.; Momenté, G.; Montaruli, T.; Moulai, M.; Nahnhauer, R.; Naumann, U.; Neer, G.; Niederhausen, H.; Nowicki, S. C.; Nygren, D. R.; Obertacke Pollmann, A.; Olivas, A.; O'Murchadha, A.; Palczewski, T.; Pandya, H.; Pankova, D. V.; Peiffer, P.; Penek, Ö.; Pepper, J. A.; Pérez de Los Heros, C.; Pieloth, D.; Pinat, E.; Price, P. B.; Przybylski, G. T.; Quinnan, M.; Raab, C.; Rädel, L.; Rameez, M.; Rawlins, K.; Reimann, R.; Relethford, B.; Relich, M.; Resconi, E.; Rhode, W.; Richman, M.; Riedel, B.; Robertson, S.; Rongen, M.; Rott, C.; Ruhe, T.; Ryckbosch, D.; Rysewyk, D.; Sabbatini, L.; Sanchez Herrera, S. E.; Sandrock, A.; Sandroos, J.; Sarkar, S.; Satalecka, K.; Schlunder, P.; Schmidt, T.; Schoenen, S.; Schöneberg, S.; Schumacher, L.; Seckel, D.; Seunarine, S.; Soldin, D.; Song, M.; Spiczak, G. M.; Spiering, C.; Stachurska, J.; Stanev, T.; Stasik, A.; Stettner, J.; Steuer, A.; Stezelberger, T.; Stokstad, R. G.; Stößl, A.; Ström, R.; Strotjohann, N. L.; Sullivan, G. W.; Sutherland, M.; Taavola, H.; Taboada, I.; Tatar, J.; Tenholt, F.; Ter-Antonyan, S.; Terliuk, A.; Tešić, G.; Tilav, S.; Toale, P. A.; Tobin, M. N.; Toscano, S.; Tosi, D.; Tselengidou, M.; Tung, C. F.; Turcati, A.; Unger, E.; Usner, M.; Vandenbroucke, J.; van Eijndhoven, N.; Vanheule, S.; van Rossem, M.; van Santen, J.; Vehring, M.; Voge, M.; Vogel, E.; Vraeghe, M.; Walck, C.; Wallace, A.; Wallraff, M.; Wandkowsky, N.; Waza, A.; Weaver, Ch.; Weiss, M. J.; Wendt, C.; Westerhoff, S.; Whelan, B. J.; Wickmann, S.; Wiebe, K.; Wiebusch, C. H.; Wille, L.; Williams, D. R.; Wills, L.; Wolf, M.; Wood, T. R.; Woolsey, E.; Woschnagg, K.; Xu, D. L.; Xu, X. W.; Xu, Y.; Yanez, J. P.; Yodh, G.; Yoshida, S.; Zoll, M.; Asas-Sn Collaboration; Stanek, K. Z.; Shappee, B. J.; Kochanek, C. S.; Holoien, T. W. -S.; Prieto, J. L.; Astrophysical Multimessenger Observatory Network; Fox, D. B.; Delaunay, J. J.; Turley, C. F.; Barthelmy, S. D.; Lien, A. Y.; Mészáros, P.; Murase, K.; Fermi Collaboration; Kocevski, D.; Buehler, R.; Giomi, M.; Racusin, J. L.; Hawc Collaboration; Albert, A.; Alfaro, R.; Alvarez, C.; Álvarez, J. D.; Arceo, R.; Arteaga-Velázquez, J. C.; Ayala Solares, H. A.; Barber, A. S.; Baustista-Elivar, N.; Becerril, A.; Belmont-Moreno, E.; Bernal, A.; Brisbois, C.; Caballero-Mora, K. S.; Capistrán, T.; Carramiñana, A.; Casanova, S.; Castillo, M.; Cotti, U.; Coutiño de León, S.; de La Fuente, E.; de León, C.; Diaz Hernandez, R.; Díaz-Vélez, J. C.; Dingus, B. L.; Duvernois, M. A.; Ellsworth, R. W.; Engel, K.; Fiorino, D. W.; Fraija, N.; García-González, J. A.; Gerhardt, M.; González Muñoz, A.; González, M. M.; Goodman, J. A.; Hampel-Arias, Z.; Harding, J. P.; Hernandez, S.; Hui, C. M.; Hüntemeyer, P.; Iriarte, A.; Jardin-Blicq, A.; Joshi, V.; Kaufmann, S.; Lara, A.; Lauer, R. J.; Lee, W. H.; Lennarz, D.; León Vargas, H.; Linnemann, J. T.; Luis Raya, G.; Luna-García, R.; López-Coto, R.; Malone, K.; Marinelli, S. S.; Martinez, O.; Martinez-Castellanos, I.; Martínez-Castro, J.; Martínez-Huerta, H.; Matthews, J. A.; Miranda-Romagnoli, P.; Moreno, E.; Mostafá, M.; Nellen, L.; Newbold, M.; Nisa, M. U.; Noriega-Papaqui, R.; Pelayo, R.; Pretz, J.; Pérez-Pérez, E. G.; Ren, Z.; Rho, C. D.; Rivière, C.; Rosa-González, D.; Rosenberg, M.; Salesa Greus, F.; Sandoval, A.; Schneider, M.; Schoorlemmer, H.; Sinnis, G.; Smith, A. J.; Springer, R. W.; Surajbali, P.; Tibolla, O.; Tollefson, K.; Torres, I.; Ukwatta, T. N.; Villaseñor, L.; Weisgarber, T.; Wisher, I. G.; Wood, J.; Yapici, T.; Zepeda, A.; Zhou, H.; Lco Collaboration; Arcavi, I.; Hosseinzadeh, G.; Howell, D. A.; Valenti, S.; McCully, C.; Master Collaboration; Lipunov, V. M.; Gorbovskoy, E. S.; Tiurina, N. V.; Balanutsa, P. V.; Kuznetsov, A. S.; Kornilov, V. G.; Chazov, V.; Budnev, N. M.; Gress, O. A.; Ivanov, K. I.; Tlatov, A. G.; Rebolo Lopez, R.; Serra-Ricart, M.; Swift Collaboration; Evans, P. A.; Kennea, J. A.; Gehrels, N.; Osborne, J. P.; Page, K. L.; VERITAS Collaboration; Abeysekara, A. U.; Archer, A.; Benbow, W.; Bird, R.; Brantseg, T.; Bugaev, V.; v Cardenzana, J.; Connolly, M. P.; Cui, W.; Falcone, A.; Feng, Q.; Finley, J. P.; Fleischhack, H.; Fortson, L.; Furniss, A.; Griffin, S.; Grube, J.; Hütten, M.; Hervet, O.; Holder, J.; Hughes, G.; Humensky, T. B.; Johnson, C. A.; Kaaret, P.; Kar, P.; Kelley-Hoskins, N.; Kertzman, M.; Krause, M.; Kumar, S.; Lang, M. J.; Lin, T. T. Y.; McArthur, S.; Moriarty, P.; Mukherjee, R.; Nieto, D.; Ong, R. A.; Otte, A. N.; Pohl, M.; Popkow, A.; Pueschel, E.; Quinn, J.; Ragan, K.; Reynolds, P. T.; Richards, G. T.; Roache, E.; Rulten, C.; Sadeh, I.; Santander, M.; Sembroski, G. H.; Staszak, D.; Trépanier, S.; Tyler, J.; Wakely, S. P.; Weinstein, A.; Wilcox, P.; Wilhelm, A.; Williams, D. A.; Zitzer, B.; Bellm, E.; Cano, Z.; Gal-Yam, A.; Kann, D. A.; Ofek, E. O.; Rigault, M.; Soumagnac, M., On February 17, 2016, the IceCube real-time neutrino search identified, for the first time, three muon neutrino candidates arriving within 100 s of one another, consistent with coming from the same point in the sky. Such a triplet is expected once every 13.7 years as a random coincidence of background events. However, considering the lifetime of the follow-up program the probability of detecting at least one triplet from atmospheric background is 32%. Follow-up observatories were notified in order to search for an electromagnetic counterpart. Observations were obtained by Swift's X-ray telescope, by ASAS-SN, LCO and MASTER at optical wavelengths, and by VERITAS in the very-high-energy gamma-ray regime. Moreover, the Swift BAT serendipitously observed the location 100 s after the first neutrino was detected, and data from the Fermi LAT and HAWC observatory were analyzed. We present details of the neutrino triplet and the follow-up observations. No likely electromagnetic counterpart was detected, and we discuss the implications of these constraints on candidate neutrino sources such as gamma-ray bursts, core-collapse supernovae and active galactic nucleus flares. This study illustrates the potential of and challenges for future follow-up campaigns. © ESO, 2017. © ESO, 2017., The IceCube Collaboration acknowledges the support from the following agencies: US National Science Foundation-Office of Polar Programs, US National Science Foundation-Physics Division, University of Wisconsin Alumni Research Foundation, the Grid Laboratory of Wisconsin (GLOW) grid infrastructure at the University of Wisconsin – Madison, the Open Science Grid (OSG) grid infrastructure; US Department of Energy, and National Energy Research Scientific Computing Center, the Louisiana Optical Network Initiative (LONI) grid computing resources; Natural Sciences and Engineering Research Council of Canada, WestGrid and Compute/Calcul Canada; Swedish Research Council, Swedish Polar Research Secretariat, Swedish National Infrastructure for Computing (SNIC), and Knut and Alice Wallenberg Foundation, Sweden; German Ministry for Education and Research (BMBF), Deutsche Forschungsgemeinschaft (DFG), Helmholtz Alliance for Astroparticle Physics (HAP), Research Department of Plasmas with Complex Interactions (Bochum), Germany; Fund for Scientific Research (FNRS-FWO), FWO Odysseus programme, Flanders Institute to encourage scientific and technological research in industry (IWT), Belgian Federal Science Policy Office (Belspo); University of Oxford, United Kingdom; Marsden Fund, New Zealand; Australian Research Council; Japan Society for Promotion of Science (JSPS); the Swiss National Science Foundation (SNSF), Switzerland; National Research Foundation of Korea (NRF); Villum Fonden, Danish National Research Foundation (DNRF), Denmark This work made use of data supplied by the UK Swift Science Data Centre at the University of Leicester. Funding for the Swift project in the UK is provided by the UK Space Agency. Part of this work was facilitated by the GROWTH project, a partnership in international research and education, NSF PIRE Grant No. 1545949. ASAS-SN is supported by NSF grant AST-1515927. Development of ASAS-SN has been supported by NSF grant AST-0908816, the Center for Cosmology and AstroParticle Physics at the Ohio State University, the Mt. Cuba Astronomical Foundation, and by George Skestos. 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. The HAWC Collaboration acknowledges the support from: the US National Science Foundation (NSF); the US Department of Energy Office of High-Energy Physics; the Laboratory Directed Research and Development (LDRD) program of Los Alamos National Laboratory; Consejo Nacional de Ciencia y Tecnología (CONACyT), México (grants 271051, 232656, 260378, 179588, 239762, 254964, 271737, 258865, 243290, 132197), Laboratorio Nacional HAWC de rayos gamma; L’OREAL Fellowship for Women in Science 2014; Red HAWC, México; DGAPA-UNAM (grants IG100317, IN111315, IN111716-3, IA102715, 109916, IA102917); VIEP-BUAP; PIFI 2012, 2013, PROFOCIE 2014, 2015;the University of Wisconsin Alumni Research Foundation; the Institute of Geophysics, Planetary Physics, andSignatures at Los Alamos National Laboratory; Polish Science Centre grant DEC-2014/13/B/ST9/945; Coordinación de la Investigación Científica de la Universidad Michoacana. We thank Luciano Díaz and Eduardo Murrieta for technical support of the HAWC detector. Support for I. Arcavi was provided by NASA through the Einstein Fellowship Program, grant PF6-170148. D. A. Howell, C. McCully, and G. Hosseinzadeh are supported by NSF-1313484. This work makes use of observations from the LCO network. VERITAS research is supported by grants from the U.S. Department of Energy Office of Science, the U.S. National Science Foundation and the Smithsonian Institution, and by NSERC in Canada. VERITAS acknowledges the excellent work of the technical support staff at the Fred Lawrence Whipple Observatory and at the collaborating institutions in the construction and operation of the instrument. E. O. Ofek and A. Gal-Yam acknowledge a Minerva grant.
Published: 2017
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43. Dark matter constraints from a joint analysis of dwarf Spheroidal galaxy observations with VERITAS

Author: Archambault, S., Archer, A., Benbow, W., Bird, R., Bourbeau, E., Brantseg, T., Buchovecky, M., Buckley, J. H., Bugaev, V., Byrum, K., Cerruti, M., Christiansen, J. L., Connolly, M. P., Cui, W., Daniel, M. K., Feng, Q., Finley, J. P., Fleischhack, H., Fortson, L., Furniss, A., Geringer-Sameth, A., Griffin, S., Grube, J., Hütten, M., Håkansson, N., Hanna, D., Hervet, O., Holder, J., Hughes, G., Hummensky, B., Johnson, C. A., Kaaret, P., Kar, P., Kelley-Hoskins, N., Kertzman, M., Kieda, D., Koushiappas, S., Krause, M., Krennrich, F., Lang, M. J., Lin, T. T. Y., McArthur, S., Moriarty, P., Mukherjee, R., Nieto, D., O’Brien, S., Ong, R. A., Otte, A. N., Park, N., Pohl, Martin, Popkow, A., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Richards, G. T., Roache, E., Rulten, C., Sadeh, I., Santander, M., Sembroski, G. H., Shahinyan, K., Smith, A. W., Staszak, D., Telezhinsky, I., Trepanier, S., Tucci, J. V., Tyler, J., Wakely, S. P., Weinstein, A., Wilcox, P., Williams, D. A., and Zitzer, B.
Abstract: Physical review / D 95(8), 082001(2017). doi:10.1103/PhysRevD.95.082001, We present constraints on the annihilation cross section of weakly interacting massive particles dark matter based on the joint statistical analysis of four dwarf galaxies with VERITAS. These results are derived from an optimized photon weighting statistical technique that improves on standard imaging atmospheric Cherenkov telescope (IACT) analyses by utilizing the spectral and spatial properties of individual photon events. We report on the results of ∼ 230 hours of observations of five dwarf galaxies and the joint statistical analysis of four of the dwarf galaxies. We find no evidence of gamma-ray emission from any individual dwarf nor in the joint analysis. The derived upper limit on the dark matter annihilation cross section from the joint analysis is 1.35 × 10$^{−23}$ cm$^{3}$ s$^{−1}$ at 1 TeV for the bottom quark $(b\bar{b})$ final state, 2.85 × 10$^{−24}$ cm$^{3}$ s$^{−1}$ at 1 TeV for the tau lepton $(\tau^{+}\tau^{−})$ final state and 1.32 × 10$^{−25}$ cm$^3$ s$^{−1}$ at 1 TeV for the gauge boson $(\gamma\gamma)$ final state., Published by APS, Woodbury, NY
Published: 2017
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44. Very-High-Energy $\gamma$-Ray Observations of the Blazar 1ES 2344+514 with VERITAS

Author: Allen, C., Archambault, S., Archer, A., Benbow, W., Bird, R., Bourbeau, E., Brose, R., Buchovecky, M., Buckley, J. H., Bugaev, V., Cardenzana, J. V, Cerruti, M., Chen, X., Christiansen, J. L., Connolly, M. P., Cui, W., Daniel, M. K., Eisch, J. D., Falcone, A., Feng, Q., Fernandez-Alonso, M., Finley, J. P., Fleischhack, H., Flinders, A., Fortson, L., Furniss, A., Gillanders, G. H., Griffin, S., Grube, J., Hütten, M., Håkansson, N., Hanna, D., Hervet, O., Holder, J., Hughes, G., Humensky, T. B., Johnson, C. A., Kaaret, P., Kar, P., Kelley-Hoskins, N., Kertzman, M., Kieda, D., Krause, Maria, Krennrich, F., Kumar, S., Lang, M. J., Maier, Gernot, McArthur, S., McCann, A., Meagher, K., Moriarty, P., Mukherjee, R., Nguyen, T., Nieto, D., O'Brien, S., De Bhróithe, A. O'Faoláin, Ong, R. A., Otte, A. N., Park, N., Petrashyk, A., Pichel, A., Pohl, Martin, Popkow, A., 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., Telezhinsky, I., Tucci, J. V., Tyler, J., Wakely, S. P., Weinstein, A., Wilhelm, Alina, and Williams, D. A.
Abstract: Monthly notices of the Royal Astronomical Society 471(2), 2117 - 2123 (2017). doi:10.1093/mnras/stx1756, We present very-high-energy $\gamma$-ray observations of the BL Lac object 1ES 2344+514 taken by the Very Energetic Radiation Imaging Telescope Array System between 2007 and 2015. 1ES 2344+514 is detected with a statistical significance above the background of 20.8σ in 47.2 h (livetime) of observations, making this the most comprehensive very-high-energy study of 1ES 2344+514 to date. Using these observations, the temporal properties of 1ES 2344+514 are studied on short and long times-scales. We fit a constant-flux model to nightly and seasonally binned light curves and apply a fractional variability test to determine the stability of the source on different time-scales. We reject the constant-flux model for the 2007–2008 and 2014–2015 nightly binned light curves and for the long-term seasonally binned light curve at the > 3σ level. The spectra of the time-averaged emission before and after correction for attenuation by the extragalactic background light are obtained. The observed time-averaged spectrum above 200 GeV is satisfactorily fitted ($χ^2$/NDF = 7.89/6) by a power-law function with an index Γ = 2.46 ± 0.06stat ± 0.20sys and extends to at least 8 TeV. The extragalactic-background-light-deabsorbed spectrum is adequately fit ($χ^2$/NDF = 6.73/6) by a power-law function with an index Γ = 2.15 ± 0.06stat ± 0.20sys while an F-test indicates that the power law with an exponential cut-off function provides a marginally better fit ($χ^2$/NDF = 2.56/5) at the 2.1σ level. The source location is found to be consistent with the published radio location and its spatial extent is consistent with a point source., Published by Oxford Univ. Press, Oxford
Published: 2017
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45. First NuSTAR Observations of Mrk 501 within a Radio to TeV Multi-Instrument Campaign

Author: Furniss, A., Noda, K., Boggs, S., Chiang, J., Christensen, F., Craig, W., Giommi, P., Hailey, C., Harisson, F., Madejski, G., Nalewajko, K., PERRI, Matteo, Stern, D., Urry, M., VERRECCHIA, Francesco, Zhang, W., NuSTAR Team, Ahnen, M. L., ANTONELLI, Lucio Angelo, Antonelli, L. A., Antoranz, P., Babic, A., Banerjee, B., Bangale, P., Barres de Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bernardini, E., Biasuzzi, B., Biland, A., Blanch, O., Bonnefoy, S., Bonnoli, G., Borracci, F., Bretz, T., Carmona, E., Carosi, A., Chatterjee, A., Clavero, R., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., COVINO, Stefano, Da Vela, P., Dazzi, F., De Angelis, A., De Caneva, G., De Lotto, B., de Oña Wilhelmi, E., Delgado Mendez, C., Di Pierro, F., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Eisenacher Glawion, D., Elsaesser, D., Fernández-Barral, A., Fidalgo, D., Fonseca, M. V., Font, L., Frantzen, K., Fruck, C., Galindo, D., García López, R. J., Garczarczyk, M., Garrido Terrats, D., Gaug, M., Giammaria, P., Godinović, N., González Muñoz, A., Guberman, D., Hanabata, Y., Hayashida, M., Herrera, J., Hose, J., Hrupec, D., Hughes, G., Idec, W., Kellermann, H., Kodani, K., Konno, Y., Kubo, H., Kushida, J., LA BARBERA, ANTONINO, Lelas, D., Lewandowska, N., Lindfors, E., LOMBARDI, Saverio, Longo, F., López, M., López-Coto, R., López-Oramas, A., Lorenz, E., Majumdar, P., Makariev, M., Mallot, K., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Marcote, B., Mariotti, M., Martínez, M., Mazin, D., Menzel, U., Miranda, J. M., Mirzoyan, R., Moralejo, A., Nakajima, D., Neustroev, V., Niedzwiecki, A., Nievas Rosillo, M., Nilsson, K., Nishijima, K., Orito, R., Overkemping, A., PAIANO, Simona, Palacio, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Paredes-Fortuny, X., Persic, M., Poutanen, J., Prada Moroni, P. G., PRANDINI, ELISA, Puljak, I., Reinthal, R., Rhode, W., Ribó, M., Rico, J., Rodriguez Garcia, J., Saito, T., Saito, K., Satalecka, K., Scapin, V., Schultz, C., Schweizer, T., Shore, S. N., Sillanpää, A., Sitarek, J., Snidaric, I., Sobczynska, D., STAMERRA, Antonio, Steinbring, T., Strzys, M., Takalo, L., Takami, H., TAVECCHIO, Fabrizio, Temnikov, P., Terzić, T., Tescaro, D., Teshima, M., Thaele, J., Torres, D. F., Toyama, T., Treves, A., Verguilov, V., Vovk, I., Will, M., Zanin, R., MAGIC Collaboration, Archer, A., Benbow, W., Bird, R., Biteau, J., Bugaev, V., Cardenzana, J. V., Cerruti, M., Chen, X., Ciupik, L., Connolly, M. P., Cui, W., Dickinson, H. J., Dumm, J., Eisch, J. D., Falcone, A., Feng, Q., Finley, J. P., Fleischhack, H., Fortin, P., Fortson, L., Gerard, L., Gillanders, G. H., Griffin, S., Griffiths, S. T., Grube, J., Gyuk, G., Håkansson, N., Holder, J., Humensky, T. B., Johnson, C. A., Kaaret, P., Kertzman, M., Kieda, D., Krause, M., Krennrich, F., Lang, M. J., Lin, T. T. Y., Maier, G., McArthur, S., McCann, A., Meagher, K., Moriarty, P., Mukherjee, R., Nieto, D., O'Faoláin de Bhróithe, A., Ong, R. A., Park, N., Petry, D., Pohl, M., Popkow, A., Ragan, K., Ratliff, G., Reyes, L. C., Reynolds, P. T., Richards, G. T., Roache, E., Santander, M., Sembroski, G. H., Shahinyan, K., Staszak, D., Telezhinsky, I., Tucci, J. V., Tyler, J., Vassiliev, V. V., Wakely, S. P., Weiner, O. M., Weinstein, A., Wilhelm, A., Williams, D. A., Zitzer, B., VERITAS Collaboration, Vince, O., Fuhrmann, L., Angelakis, E., Karamanavis, V., Myserlis, I., Krichbaum, T. P., Zensus, J. A., Ungerechts, H., Sievers, A., F-Gamma Consortium, The, Bachev, R., Böttcher, M., Chen, W. P., Damljanovic, G., Eswaraiah, C., Güver, T., Hovatta, T., Hughes, Z., Ibryamov, S. I., Joner, M. D., Jordan, B., Jorstad, S. G., Joshi, M., Kataoka, J., Kurtanidze, O. M., Kurtanidze, S. O., Lähteenmäki, A., Latev, G., Lin, H. C., Larionov, V. M., Mokrushina, A. A., Morozova, D. A., Nikolashvili, M. G., RAITERI, Claudia Maria, Ramakrishnan, V., Readhead, A. C. R., Sadun, A. C., Sigua, L. A., Semkov, E. H., Strigachev, A., Tammi, J., Tornikoski, M., Troitskaya, Y. V., Troitsky, I. S., VILLATA, Massimo, Department of Radio Science and Engineering, Aalto-yliopisto, Aalto University, Universitat de Barcelona, Furniss, A., Noda, K., Boggs, S., Chiang, J., Christensen, F., Craig, W., Giommi, P., Hailey, C., Harisson, F., Madejski, G., Nalewajko, K., Perri, M., Stern, D., Urry, M., Verrecchia, F., Zhang, W., Ahnen, M. L., Ansoldi, S., Antonelli, L. A., Antoranz, P., Babic, A., Banerjee, B., Bangale, P., Barres De Almeida, U., J., A. Barrio, Becerra González, J., Bednarek, W., Bernardini, E., Biasuzzi, B., Biland, A., Blanch, O., Bonnefoy, S., Bonnoli, G., Borracci, F., Bretz, T., Carmona, E., Carosi, A., Chatterjee, A., Clavero, R., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Da Vela, P., Dazzi, F., De Angelis, A., De Caneva, G., De Lotto, B., De Oña Wilhelmi, E., Delgado Mendez, C., Di Pierro, F., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Eisenacher Glawion, D., Elsaesser, D., Fernández Barral, A., Fidalgo, D., Fonseca, M. V., Font, L., Frantzen, K., Fruck, C., Galindo, D., García López, R. J., Garczarczyk, M., Garrido Terrats, D., Gaug, M., Giammaria, P., Godinović, N., González Muñoz, A., Guberman, D., Hanabata, Y., Hayashida, M., Herrera, J., Hose, J., Hrupec, D., Hughes, G., Idec, W., Kellermann, H., Kodani, K., Konno, Y., Kubo, H., Kushida, J., La Barbera, A., Lelas, D., Lewandowska, N., Lindfors, E., Lombardi, S., Longo, Francesco, López, M., López Coto, R., López Oramas, A., Lorenz, E., Majumdar, P., Makariev, M., Mallot, K., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Marcote, B., Mariotti, M., Martínez, M., Mazin, D., Menzel, U., Miranda, J. M., Mirzoyan, R., Moralejo, A., Nakajima, D., Neustroev, V., Niedzwiecki, A., Nievas Rosillo, M., Nilsson, K., Nishijima, K., Orito, R., Overkemping, A., Paiano, S., Palacio, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Paredes Fortuny, X., Persic, M., Poutanen, J., Prada Moroni, P. G., Prandini, E., Puljak, I., Reinthal, R., Rhode, W., Ribó, M., Rico, J., Rodriguez Garcia, J., Saito, T., Saito, K., Satalecka, K., Scapin, V., Schultz, C., Schweizer, T., Shore, S. N., Sillanpä, A., Sitarek, J., Snidaric, I., Sobczynska, D., Stamerra, A., Steinbring, T., Strzys, M., Takalo, L., Takami, H., Tavecchio, F., Temnikov, P., Terzić, T., Tescaro, D., Teshima, M., Thaele, J., Torres, D. F., Toyama, T., Treves, A., Verguilov, V., Vovk, I., Will, M., Zanin, R., Archer, A., Benbow, W., Bird, R., Biteau, J., Bugaev, V., Cardenzana, J. V., Cerruti, M., Chen, X., Ciupik, L., Connolly, M. P., Cui, W., Dickinson, H. J., Dumm, J., Eisch, J. D., Falcone, A., Feng, Q., Finley, J. P., Fleischhack, H., Fortin, P., Fortson, L., Gerard, L., Gillanders, G. H., Griffin, S., Griffiths, S. T., Grube, J., Gyuk, G., Håkansson, N., Holder, J., Humensky, T. B., Johnson, C. A., Kaaret, P., Kertzman, M., Kieda, D., Krause, M., Krennrich, F., Lang, M. J., Lin, T. T. Y., Maier, G., Mcarthur, S., Mccann, A., Meagher, K., Moriarty, P., Mukherjee, R., Nieto, D., O'Faoláin De Bhróithe, A., Ong, R. A., Park, N., Petry, D., Pohl, M., Popkow, A., Ragan, K., Ratliff, G., Reyes, L. C., Reynolds, P. T., Richards, G. T., Roache, E., Santander, M., Sembroski, G. H., Shahinyan, K., Staszak, D., Telezhinsky, I., Tucci, J. V., Tyler, J., Vassiliev, V. V., Wakely, S. P., Weiner, O. M., Weinstein, A., Wilhelm, A., Williams, D. A., Zitzer, B., Vince, O., Fuhrmann, L., Angelakis, E., Karamanavis, V., Myserlis, I., Krichbaum, T. P., Zensus, J. A., Ungerechts, H., Sievers, A., Bachev, R., Böttcher, M., Chen, W. P., Damljanovic, G., Eswaraiah, C., Güver, T., Hovatta, T., Hughes, Z., Ibryamov, S. I., Joner, M. D., Jordan, B., Jorstad, S. G., Joshi, M., Kataoka, J., Kurtanidze, O. M., Kurtanidze, S. O., Lähteenmäki, A., Latev, G., Lin, H. C., Larionov, V. M., Mokrushina, A. A., Morozova, D. A., Nikolashvili, M. G., Raiteri, C. M., Ramakrishnan, V., A. C., R. Readhead, Sadun, A. C., Sigua, L. A., Semkov, E. H., Strigachev, A., Tammi, J., Tornikoski, M., Troitskaya, Y. V., Troitsky, I. S., Villata, M., ~, and 24420530 - Böttcher, Markus
Subjects: galaxie [X-rays], Astrophysics, galaxies BL Lacs, galaxies individual (Markarian 501), X-rays, 01 natural sciences, Luminosity, law.invention, bl lacertae objects, law, MAGIC (telescope), individual: Markarian 501 [galaxies], 010303 astronomy & astrophysics, astro-ph.HE, High Energy Astrophysical Phenomena (astro-ph.HE), BL Lacertae objects: general, galaxies: individual: Markarian 501, X-rays: galaxies, Physics, Astrophysics::Instrumentation and Methods for Astrophysics, fermi-lat, galaxies [X-rays], large-area telescope, BL Lacertae objects: general, galaxies: individual (Markarian 501), X-rays: galaxies, individual (Markarian 501) [galaxies], Spectral energy distribution, Electrónica, Física nuclear, Individual (Markarian 501), Raigs X, Electricidad, Astrophysics - High Energy Astrophysical Phenomena, Nuclear and High Energy Physics, BL Lac object, multiwavelength observations, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Optical telescope, Telescope, 0103 physical sciences, crab-nebula, Blazar, galaxies: individual (markarian 501), particle-acceleration, 010308 nuclear & particles physics, general [BL Lacertae objects], galaxies: individual: Markarian 501, Institut für Physik und Astronomie, Astronomy and Astrophysics, gamma-ray emission, Galaxies, Galàxies, x-ray, Space and Planetary Science, ddc:520, magic telescope, log-parabolic spectra, Fermi Gamma-ray Space Telescope
Abstract: We report on simultaneous broadband observations of the TeV-emitting blazar Markarian 501 between 1 April and 10 August 2013, including the first detailed characterization of the synchrotron peak with Swift and NuSTAR. During the campaign, the nearby BL Lac object was observed in both a quiescent and an elevated state. The broadband campaign includes observations with NuSTAR, MAGIC, VERITAS, the Fermi Large Area Telescope (LAT), Swift X-ray Telescope and UV Optical Telescope, various ground-based optical instruments, including the GASP-WEBT program, as well as radio observations by OVRO, Mets\"ahovi and the F-Gamma consortium. Some of the MAGIC observations were affected by a sand layer from the Saharan desert, and had to be corrected using event-by-event corrections derived with a LIDAR (LIght Detection And Ranging) facility. This is the first time that LIDAR information is used to produce a physics result with Cherenkov Telescope data taken during adverse atmospheric conditions, and hence sets a precedent for the current and future ground-based gamma-ray instruments. The NuSTAR instrument provides unprecedented sensitivity in hard X-rays, showing the source to display a spectral energy distribution between 3 and 79 keV consistent with a log-parabolic spectrum and hard X-ray variability on hour timescales. None (of the four extended NuSTAR observations) shows evidence of the onset of inverse-Compton emission at hard X-ray energies. We apply a single-zone equilibrium synchrotron self-Compton model to five simultaneous broadband spectral energy distributions. We find that the synchrotron self-Compton model can reproduce the observed broadband states through a decrease in the magnetic field strength coinciding with an increase in the luminosity and hardness of the relativistic leptons responsible for the high-energy emission., Comment: Accepted for publication in ApJ
Published: 2015
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46. Multi-wavelength Observations of the Flaring Gamma-ray Blazar 3C 66A in 2008 October

Author: Abdo, A. A., Ackermann, M., Ajello, M., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bonamente, Emanuele, Borgland, A. W., Bouvier, A., Bregeon, J., Brez, A., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Carrigan, S., Casandjian, J. M., Cavazzuti, E., Cecchi, Claudia, Çelik, Ö., Charles, E., Chekhtman, A., Cheung, C. C., Chiang, J., Ciprini, S., Claus, R., Cohen Tanugi, J., Conrad, J., Costamante, L., Cutini, S., Davis, D. S., Dermer, C. D., Palma, F. d., Digel, S. W., Couto, E. d., Drell, P. S., Dubois, R., Dumora, D., Favuzzi, C., Fegan, S. J., Fortin, P., Frailis, M., Fuhrmann, L., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grove, J. E., Guillemot, L., Guiriec, S., Hadasch, D., Hayashida, M., Hays, E., Horan, D., Hughes, R. E., Itoh, R., Jóhannesson, G., Johnson, A. S., Johnson, T. J., Johnson, W. N., Kamae, T., Katagiri, H., Kataoka, J., Knödlseder, J., Kuss, M., Lande, J., Latronico, L., Lee, S., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Makeev, A., Mazziotta, M. N., Mcenery, J. E., Mehault, J., Michelson, P. F., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Naumann Godo, M., Nestoras, I., Nolan, P. L., Norris, J. P., Nuss, E., Ohsugi, T., Okumura, A., Omodei, N., Orlando, E., Ormes, J. F., Ozaki, M., Paneque, D., Panetta, J. H., Parent, D., Pelassa, V., Pepe, M., Pesce Rollins, M., Piron, F., Porter, T. A., Rainò, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Reyes, L. C., Ripken, J., Ritz, S., Romani, R. W., Roth, M., Sadrozinski, H. F., Sanchez, D., Sander, A., Scargle, J. D., Sgrò, C., Shaw, M. S., Smith, P. D., Spandre, G., Spinelli, P., Strickman, M. S., Suson, D. J., Takahashi, H., Tanaka, T., Thayer, J. B., Thayer, J. G., Thompson, D. J., Tibaldo, L., Torres, D. F., Tosti, Gino, Tramacere, A., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vilchez, N., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Yang, Z., Ylinen, T., Ziegler, M., Acciari, V. A., Aliu, E., Arlen, T., Aune, T., Beilicke, M., Benbow, W., Böttcher, M., Boltuch, D., Bradbury, S. M., Buckley, J. H., Bugaev, V., Byrum, K., Cannon, A., Cesarini, A., Christiansen, J. L., Ciupik, L., Cui, W., I. d., La, Dickherber, R., Errando, M., Falcone, A., Finley, J. P., Finnegan, G., Fortson, L., Furniss, A., Galante, N., Gall, D., Gillanders, G. H., Godambe, S., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Holder, J., Hui, C. M., Humensky, T. B., Imran, A., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., Lebohec, S., Maier, G., Mcarthur, S., Mccann, A., Mccutcheon, M., Moriarty, P., Mukherjee, R., Ong, R. A., Otte, A. N., Pandel, D., Perkins, J. S., Pichel, A., Pohl, M., Quinn, J., Ragan, K., Reynolds, P. T., Roache, E., Rose, H. J., Schroedter, M., Sembroski, G. H., Senturk, G. D., Smith, A. W., Steele, D., Swordy, S. P., Tešić, G., Theiling, M., Thibadeau, S., Varlotta, A., Vassiliev, V. V., Vincent, S., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., Weisgarber, T., Williams, D. A., Wissel, S., Wood, M., Villata, M., Raiteri, C. M., Gurwell, M. A., Larionov, V. M., Kurtanidze, O. M., Aller, M. F., Lähteenmäki, A., Chen, W. P., Berduygin, A., Agudo, I., Aller, H. D., Arkharov, A. A., Bach, U., Bachev, R., Beltrame, P., Benítez, E., Buemi, C. S., Dashti, J., Calcidese, P., Capezzali, D., Carosati, D., Rio, D. D., Paola, A. D., Diltz, C., Dolci, M., Dultzin, D., Forné, E., Gómez, J. L., Hagen Thorn, V. A., Halkola, A., Heidt, J., Hiriart, D., Hovatta, T., Hsiao, H., Jorstad, S. G., Kimeridze, G. N., Konstantinova, T. S., Kopatskaya, E. N., Koptelova, E., Leto, P., Ligustri, R., Lindfors, E., Lopez, J. M., Marscher, A. P., Mommert, M., Mujica, R., Nikolashvili, M. G., Nilsson, K., Palma, N., Pasanen, M., Roca Sogorb, M., Ros, J. A., Roustazadeh, P., Sadun, A. C., Saino, J., Sigua, L. A., Sillanää, A., Sorcia, M., Takalo, L. O., Tornikoski, M., Trigilio, C., Turchetti, R., Umana, G., Belloni, T., Blake, C. H., Bloom, J. S., Angelakis, E., Fumagalli, M., Hauser, M., Prochaska, J. X., Riquelme, D., Sievers, A., Starr, D. L., Tagliaferri, G., Ungerechts, H., Wagner, S., Zensus, J. A., Collaboration, F. L., Collaboration, V., Consortium, G., Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Laboratoire Leprince-Ringuet (LLR), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Laboratoire de Physique Théorique et Astroparticules (LPTA), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre d'étude spatiale des rayonnements (CESR), Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Fermi-LAT, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Abdo, A. A., Ackermann, M., Ajello, M., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bonamente, E., Borgland, A. W., Bouvier, A., Bregeon, J., Brez, A., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Carrigan, S., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Çelik, Ö., Charles, E., Chekhtman, A., Cheung, C. C., Chiang, J., Ciprini, S., Claus, R., Cohen Tanugi, J., Conrad, J., Costamante, L., Cutini, S., Davis, D. S., Dermer, C. D., de Palma, F., Digel, S. W., do Couto, e. Silva E., Drell, P. S., Dubois, R., Dumora, D., Favuzzi, C., Fegan, S. J., Fortin, P., Frailis, M., Fuhrmann, L., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grove, J. E., Guillemot, L., Guiriec, S., Hadasch, D., Hayashida, M., Hays, E., Horan, D., Hughes, R. E., Itoh, R., Jóhannesson, G., Johnson, A. S., Johnson, T. J., Johnson, W. N., Kamae, T., Katagiri, H., Kataoka, J., Knödlseder, J., Kuss, M., Lande, J., Latronico, L., Lee, S. H., Longo, Francesco, Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Makeev, A., Mazziotta, M. N., Mcenery, J. E., Mehault, J., Michelson, P. F., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Naumann Godo, M., Nestoras, I., Nolan, P. L., Norris, J. P., Nuss, E., Ohsugi, T., Okumura, A., Omodei, N., Orlando, E., Ormes, J. F., Ozaki, M., Paneque, D., Panetta, J. H., Parent, D., Pelassa, V., Pepe, M., Pesce Rollins, M., Piron, F., Porter, T. A., Rainò, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Reyes, L. C., Ripken, J., Ritz, S., Romani, R. W., Roth, M., Sadrozinski, H. F. W., Sanchez, D., Sander, A., Scargle, J. D., Sgrò, C., Shaw, M. S., Smith, P. D., Spandre, G., Spinelli, P., Strickman, M. S., Suson, D. J., Takahashi, H., Tanaka, T., Thayer, J. B., Thayer, J. G., Thompson, D. J., Tibaldo, L., Torres, D. F., Tosti, G., Tramacere, A., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vilchez, N., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Yang, Z., Ylinen, T., Ziegler, M., Acciari, V. A., Aliu, E., Arlen, T., Aune, T., Beilicke, M., Benbow, W., Böttcher, M., Boltuch, D., Bradbury, S. M., Buckley, J. H., Bugaev, V., Byrum, K., Cannon, A., Cesarini, A., Christiansen, J. L., Ciupik, L., Cui, W., de la Calle Perez, I., Dickherber, R., Errando, M., Falcone, A., Finley, J. P., Finnegan, G., Fortson, L., Furniss, A., Galante, N., Gall, D., Gillanders, G. H., Godambe, S., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Holder, J., Hui, C. M., Humensky, T. B., Imran, A., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., Lebohec, S., Maier, G., Mcarthur, S., Mccann, A., Mccutcheon, M., Moriarty, P., Mukherjee, R., Ong, R. A., Otte, A. N., Pandel, D., Perkins, J. S., Pichel, A., Pohl, M., Quinn, J., Ragan, K., Reynolds, P. T., Roache, E., Rose, H. J., Schroedter, M., Sembroski, G. H., Senturk G., Demet, Smith, A. W., Steele, D., Swordy, S. P., Tešić, G., Theiling, M., Thibadeau, S., Varlotta, A., Vassiliev, V. V., Vincent, S., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., Weisgarber, T., Williams, D. A., Wissel, S., Wood, M., Villata, M., Raiteri, C. M., Gurwell, M. A., Larionov, V. M., Kurtanidze, O. M., Aller, M. F., Lähteenmäki, A., Chen, W. P., Berduygin, A., Agudo, I., Aller, H. D., Arkharov, A. A., Bach, U., Bachev, R., Beltrame, P., Benítez, E., Buemi, C. S., Dashti, J., Calcidese, P., Capezzali, D., Carosati, D., Da Rio, D., Di Paola, A., Diltz, C., Dolci, M., Dultzin, D., Forné, E., Gómez, J. L., Hagen Thorn, V. A., Halkola, A., Heidt, J., Hiriart, D., Hovatta, T., Hsiao, H. Y., Jorstad, S. G., Kimeridze, G. N., Konstantinova, T. S., Kopatskaya, E. N., Koptelova, E., Leto, P., Ligustri, R., Lindfors, E., Lopez, J. M., Marscher, A. P., Mommert, M., Mujica, R., Nikolashvili, M. G., Nilsson, K., Palma, N., Pasanen, M., Roca Sogorb, M., Ros, J. A., Roustazadeh, P., Sadun, A. C., Saino, J., Sigua, L. A., Sillanää, A., Sorcia, M., Takalo, L. O., Tornikoski, M., Trigilio, C., Turchetti, R., Umana, G., Belloni, T., Blake, C. H., Bloom, J. S., Angelakis, E., Fumagalli, M., Hauser, M., Prochaska, J. X., Riquelme, D., Sievers, A., Starr, D. L., Tagliaferri, G., Ungerechts, H., Wagner, S., Zensus, J. A., Abdo, A, Ackermann, M, Ajello, M, Baldini, L, Ballet, J, Barbiellini, G, Bastieri, D, Bechtol, K, Bellazzini, R, Berenji, B, Blandford, R, Bonamente, E, Borgland, A, Bouvier, A, Bregeon, J, Brez, A, Brigida, M, Bruel, P, Buehler, R, Buson, S, Caliandro, G, Cameron, R, Caraveo, P, Carrigan, S, Casandjian, J, Cavazzuti, E, Cecchi, C, Celik, O, Charles, E, Chekhtman, A, Cheung, C, Chiang, J, Ciprini, S, Claus, R, Cohen-Tanugi, J, Conrad, J, Costamante, L, Cutini, S, Davis, D, Dermer, C, De Palma, F, Digel, S, Do Couto E Silva, E, Drell, P, Dubois, R, Dumora, D, Favuzzi, C, Fegan, S, Fortin, P, Frailis, M, Fuhrmann, L, Fukazawa, Y, Funk, S, Fusco, P, Gargano, F, Gasparrini, D, Gehrels, N, Germani, S, Giglietto, N, Giommi, P, Giordano, F, Giroletti, M, Glanzman, T, Godfrey, G, Grenier, I, Grove, J, Guillemot, L, Guiriec, S, Hadasch, D, Hayashida, M, Hays, E, Horan, D, Hughes, R, Itoh, R, Johannesson, G, Johnson, A, Johnson, T, Johnson, W, Kamae, T, Katagiri, H, Kataoka, J, Knodlseder, J, Kuss, M, Lande, J, Latronico, L, Lee, S, Longo, F, Loparco, F, Lott, B, Lovellette, M, Lubrano, P, Makeev, A, Mazziotta, M, Mcenery, J, Mehault, J, Michelson, P, Mizuno, T, Moiseev, A, Monte, C, Monzani, M, Morselli, A, Moskalenko, I, Murgia, S, Nakamori, T, Naumann-Godo, M, Nestoras, I, Nolan, P, Norris, J, Nuss, E, Ohsugi, T, Okumura, A, Omodei, N, Orlando, E, Ormes, J, Ozaki, M, Paneque, D, Panetta, J, Parent, D, Pelassa, V, Pepe, M, Pesce-Rollins, M, Piron, F, Porter, T, Raino, S, Rando, R, Razzano, M, Reimer, A, Reimer, O, Reyes, L, Ripken, J, Ritz, S, Romani, R, Roth, M, Sadrozinski, H, Sanchez, D, Sander, A, Scargle, J, Sgro, C, Shaw, M, Smith, P, Spandre, G, Spinelli, P, Strickman, M, Suson, D, Takahashi, H, Tanaka, T, Thayer, J, Thompson, D, Tibaldo, L, Torres, D, Tosti, G, Tramacere, A, Usher, T, Vandenbroucke, J, Vasileiou, V, Vilchez, N, Vitale, V, Waite, A, Wang, P, Winer, B, Wood, K, Yang, Z, Ylinen, T, Ziegler, M, Acciari, V, Aliu, E, Arlen, T, Aune, T, Beilicke, M, Benbow, W, Bottcher, M, Boltuch, D, Bradbury, S, Buckley, J, Bugaev, V, Byrum, K, Cannon, A, Cesarini, A, Christiansen, J, Ciupik, L, Cui, W, De La Calle Perez, I, Dickherber, R, Errando, M, Falcone, A, Finley, J, Finnegan, G, Fortson, L, Furniss, A, Galante, N, Gall, D, Gillanders, G, Godambe, S, Grube, J, Guenette, R, Gyuk, G, Hanna, D, Holder, J, Hui, C, Humensky, T, Imran, A, Kaaret, P, Karlsson, N, Kertzman, M, Kieda, D, Konopelko, A, Krawczynski, H, Krennrich, F, Lang, M, Lebohec, S, Maier, G, Mcarthur, S, Mccann, A, Mccutcheon, M, Moriarty, P, Mukherjee, R, Ong, R, Otte, A, Pandel, D, Perkins, J, Pichel, A, Pohl, M, Quinn, J, Ragan, K, Reynolds, P, Roache, E, Rose, H, Schroedter, M, Sembroski, G, Senturk, G, Smith, A, Steele, D, Swordy, S, Tesic, G, Theiling, M, Thibadeau, S, Varlotta, A, Vassiliev, V, Vincent, S, Wakely, S, Ward, J, Weekes, T, Weinstein, A, Weisgarber, T, Williams, D, Wissel, S, Wood, M, Villata, M, Raiteri, C, Gurwell, M, Larionov, V, Kurtanidze, O, Aller, M, Lahteenmaki, A, Chen, W, Berduygin, A, Agudo, I, Aller, H, Arkharov, A, Bach, U, Bachev, R, Beltrame, P, Benitez, E, Buemi, C, Dashti, J, Calcidese, P, Capezzali, D, Carosati, D, Da Rio, D, Di Paola, A, Diltz, C, Dolci, M, Dultzin, D, Forne, E, Gomez, J, Hagen-Thorn, V, Halkola, A, Heidt, J, Hiriart, D, Hovatta, T, Hsiao, H, Jorstad, S, Kimeridze, G, Konstantinova, T, Kopatskaya, E, Koptelova, E, Leto, P, Ligustri, R, Lindfors, E, Lopez, J, Marscher, A, Mommert, M, Mujica, R, Nikolashvili, M, Nilsson, K, Palma, N, Pasanen, M, Roca-Sogorb, M, Ros, J, Roustazadeh, P, Sadun, A, Saino, J, Sigua, L, Sillanaa, A, Sorcia, M, Takalo, L, Tornikoski, M, Trigilio, C, Turchetti, R, Umana, G, Belloni, T, Blake, C, Bloom, J, Angelakis, E, Fumagalli, M, Hauser, M, Prochaska, J, Riquelme, D, Sievers, A, Starr, D, Tagliaferri, G, Ungerechts, H, Wagner, S, Zensus, J, Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)
Subjects: individual: 3C 66A [BL Lacertae objects], Ciencias Físicas, spectral energy-distribution, Astrophysics, BL Lacertae objects: individual (3C 66A), bright blazars, 01 natural sciences, law.invention, purl.org/becyt/ford/1 [https], bl lacertae objects, Astronomi, astrofysik och kosmologi, law, Astronomy, Astrophysics and Cosmology, 010303 astronomy & astrophysics, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), radio-sources, [SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], epoch vlbi survey, 95.45.+i, 96.60.qe,95.55.Ka, Gamma ray, veritas observations, large-area telescope, Wavelength, Gamma rays: galaxie, active [galaxies], galaxies [gamma rays], Spectral energy distribution, BL Lacertae objects: individual: 3C 66A, Astrophysics - High Energy Astrophysical Phenomena, CIENCIAS NATURALES Y EXACTAS, BL Lac object, individual (3C 66A) [BL Lacertae objects], [PHYS.ASTR.HE]Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Astrophysics::High Energy Astrophysical Phenomena, galaxies: active, FOS: Physical sciences, Telescope, 0103 physical sciences, gamma rays: galaxies, Blazar, tev blazars, 010308 nuclear & particles physics, Scattering, background-radiation, Astronomy and Astrophysics, purl.org/becyt/ford/1.3 [https], Astronomía, Space and Planetary Science, active galactic nuclei, ddc:520, Fermi Gamma-ray Space Telescope
Abstract: 著者人数：328名, Accepted: 2010-10-29, 資料番号: SA1002650000
Published: 2011
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47. Very high energy outburst of markarian 501 in may 2009

Author: Aliu, E., Archambault, S., Bird, R., Weiner, O. M., Weinstein, A., Welsing, R., Wilhelm, Alina, Williams, D. A., Zitzer, B., Baring, M. G., Becerra Gónzalez, J., Cillis, A. N., Horan, D., Böttcher, M., Paneque, D., VERITAS Collaboration, Bouvier, A., Buchovecky, M., Buckley, J. H., Bugaev, V., Cardenzana, J. V., Cerruti, M., Cesarini, A., Chen, Xuhui, Archer, A., Ciupik, L., Collins-Hughes, E., Connolly, M. P., Cui, W., Dumm, J., Eisch, J. D., Falcone, A., Federici, S., Feng, Q., Finley, J. P., Arlen, T., Fleischhack, H., Fortin, P., Fortson, L., Furniss, A., Galante, N., Gall, D., Gillanders, G. H., Griffin, S., Griffiths, S. T., Grube, J., Aune, T., Gyuk, G., Hütten, M., Håkansson, N., Holder, J., Hughes, Greg, Humensky, T. B., Johnson, C. A., Kaaret, P., Kar, P., Kelley-Hoskins, N., Barnacka, A., Kertzman, M., Khassen, Y., Kieda, D., Krause, M., Krawczynski, H., Krennrich, F., Lang, M. J., Madhavan, A. S., Maier, G., McArthur, S., Behera, B., McCann, A., Meagher, K., Millis, J., Moriarty, P., Mukherjee, R., Nieto, D., O’Faoláin de Bhróithe, A., Ong, R. A., Orr, M., Otte, A. N., Beilicke, M., Pandel, D., Park, N., Pelassa, V., Perkins, J. S., Pichel, A., Pohl, Martin, Popkow, A., Quinn, J., Ragan, K., Reyes, L. C., Benbow, W., Reynolds, P. T., Roache, E., Rousselle, J., Rovero, A. C., Saxon, D. B., Sembroski, G. H., Shahinyan, K., Sheidaei, F., Skole, C., Smith, A. W., Berger, K., Staszak, D., Telezhinsky, I., Theiling, M., Todd, N. W., Tucci, J. V., Tyler, J., Varlotta, A., Vassiliev, V. V., Vincent, S., Wakely, S. P., Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), VERITAS, Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Laboratoire Leprince-Ringuet ( LLR ), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -École polytechnique ( X ) -Centre National de la Recherche Scientifique ( CNRS )
Subjects: High energy, GAMMA RAYS, [ PHYS.ASTR ] Physics [physics]/Astrophysics [astro-ph], Ciencias Físicas, bl-lacertae objects, Flux, Astrophysics, 01 natural sciences, law.invention, purl.org/becyt/ford/1 [https], law, gamma ray: flux, 010303 astronomy & astrophysics, internal shocks, extragalactic radio-sources, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, spectral variability, Quiescent state, Optical polarization, large-area telescope, VERITAS, Astrophysics - High Energy Astrophysical Phenomena, CIENCIAS NATURALES Y EXACTAS, Flare, multiwavelength observations, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, GLAST, blazar, polarization: rotation, BL-LAC OBJECTS, bl lacertae objects: individual: mrk 501, 0103 physical sciences, gamma rays: galaxies, polarization: optical, Blazar, optical polarization properties, 010308 nuclear & particles physics, Institut für Physik und Astronomie, Astronomy and Astrophysics, purl.org/becyt/ford/1.3 [https], gamma-ray emission, Astronomía, Crab Nebula, gamma ray: VHE, x-ray, 13. Climate action, Space and Planetary Science, active galactic nuclei, ddc:520, spectral, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: The very high energy (VHE; E $>$ 100 GeV) blazar Markarian 501 was observed between April 17 and May 5 (MJD 54938--54956), 2009, as part of an extensive multi-wavelength campaign from radio to VHE. Strong VHE $��$-ray activity was detected on May 1st with Whipple and VERITAS, when the flux (E $>$ 400 GeV) increased to 10 times the pre-flare baseline flux ($3.9{\times 10^{-11}}~{\rm ph~cm^{-2}~s^{-1}}$), reaching five times the flux of the Crab Nebula. This coincided with a decrease in the optical polarization and a rotation of the polarization angle by 15$^{\circ}$. This VHE flare showed a fast flux variation with an increase of a factor $\sim$4 in 25 minutes, and a falling time of $\sim$50 minutes. We present the observations of the quiescent state previous to the flare and of the high state after the flare, focusing on the flux and spectral variability from Whipple, VERITAS, Fermi-LAT, RXTE, and Swift combined with optical and radio data., 13 pages, 10 figures. Accepted for publication in Astronomy and Astrophysics
Published: 2016
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48. Investigating broadband variability of the TeV blazar 1ES 1959+650

Author: Aliu, E., Archambault, S., Buckley, J. H., Bugaev, V., Cerruti, M., Chen, Xuhui, Ciupik, L., Collins-Hughes, E., Connolly, M. P., Cui, W., Dumm, J., Eisch, J. D., Arlen, T., Falcone, A., Federici, S., Feng, Q., Finley, J. P., Fleischhack, H., Fortin, P., Fortson, L., Furniss, Amy, Galante, N., Gillanders, G. H., Aune, T., Griffin, S., Griffiths, S. T., Grube, J., Gyuk, G., Håkansson, N., Hanna, D., Holder, J., Hughes, G., Hughes, Z., Humensky, T. B., Barnacka, A., Johnson, C. A., Kaaret, P., Kar, P., Kertzman, M., Khassen, Y., Kieda, D., Krawczynski, H., Krennrich, F., Lang, M. J., Madhavan, A. S., Beilicke, M., Majumdar, P., McArthur, S., McCann, A., Meagher, K., Millis, J., Moriarty, P., Mukherjee, R., Nelson, T., Nieto, D., O'Faoláin de Bhróithe, A., Benbow, W., Ong, R. A., Otte, A. N., Park, N., Perkins, J. S., Pohl, Martin, Popkow, A., Prokoph, H., Quinn, J., Ragan, K., Rajotte, J., Berger, K., Reyes, L. C., Reynolds, P. T., Richards, G. T., Roache, E., Sadun, A., Santander, M., Sembroski, G. H., Shahinyan, K., Sheidaei, F., Smith, A. W., Bird, R., Staszak, D., Telezhinsky, I., Theiling, M., Tyler, J., Varlotta, A., Vassiliev, V. V., Vincent, S., Wakely, S. P., Weekes, T. C., Weinstein, A., Bouvier, A., Welsing, R., Wilhelm, A., Williams, D. A., Zitzer, B., Böttcher, Markus, Fumagalli, M., VERITAS Collaboration, Aliu, E, Archambault, S, Arlen, T, Aune, T, Barnacka, A, Beilicke, M, Benbow, W, Berger, K, Bird, R, Bouvier, A, Buckley, J, Bugaev, V, Cerruti, M, Chen, X, Ciupik, L, Collins-Hughes, E, Connolly, M, Cui, W, Dumm, J, Eisch, J, Falcone, A, Federici, S, Feng, Q, Finley, J, Fleischhack, H, Fortin, P, Fortson, L, Furniss, A, Galante, N, Gillanders, G, Griffin, S, Griffiths, S, Grube, J, Gyuk, G, Hakansson, N, Hanna, D, Holder, J, Hughes, G, Hughes, Z, Humensky, T, Johnson, C, Kaaret, P, Kar, P, Kertzman, M, Khassen, Y, Kieda, D, Krawczynski, H, Krennrich, F, Lang, M, Madhavan, A, Majumdar, P, Mcarthur, S, Mccann, A, Meagher, K, Millis, J, Moriarty, P, Mukherjee, R, Nelson, T, Nieto, D, O'Faolain De Bhroithe, A, Ong, R, Otte, A, Park, N, Perkins, J, Pohl, M, Popkow, A, Prokoph, H, Quinn, J, Ragan, K, Rajotte, J, Reyes, L, Reynolds, P, Richards, G, Roache, E, Sadun, A, Santander, M, Sembroski, G, Shahinyan, K, Sheidaei, F, Smith, A, Staszak, D, Telezhinsky, I, Theiling, M, Tyler, J, Varlotta, A, Vassiliev, V, Vincent, S, Wakely, S, Weekes, T, Weinstein, A, Welsing, R, Wilhelm, A, Williams, D, Zitzer, B, Bottcher, M, and Fumagalli, M
Subjects: multiwavelength observations, galaxies. [Gamma rays], Astrophysics::High Energy Astrophysical Phenomena, Flux, FOS: Physical sciences, Context (language use), Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, individual (1ES 1959+650) [BL Lacertae objects], 7. Clean energy, law.invention, Telescope, 1es-1959+650, law, gamma-ray astronomy, gamma rays: galaxies, strong flares, Blazar, Astrophysics::Galaxy Astrophysics, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), BL lacertae objects: individual (1ES 1959+650), Institut für Physik und Astronomie, Astronomy and Astrophysics, Synchrotron, mkn 501, radiation, large-area telescope, Crab Nebula, synchrotron mirror model, x-ray, Space and Planetary Science, Gamma rays: galaxie, Spectral energy distribution, ddc:520, Astrophysics - High Energy Astrophysical Phenomena, Fermi Gamma-ray Space Telescope, energy
Abstract: We summarize broadband observations of the TeV-emitting blazar 1ES 1959+650, including optical R-band observations by the robotic telescopes Super-LOTIS and iTelescope, UV observations by Swift UVOT, X-ray observations by the Swift X-ray Telescope (XRT), high-energy gamma-ray observations with the Fermi Large Area Telescope (LAT) and very-high-energy (VHE) gamma-ray observations by VERITAS above 315 GeV, all taken between 17 April 2012 and 1 June 2012 (MJD 56034 and 56079). The contemporaneous variability of the broadband spectral energy distribution is explored in the context of a simple synchrotron self Compton (SSC) model. In the SSC emission scenario, we find that the parameters required to represent the high state are significantly different than those in the low state. Motivated by possible evidence of gas in the vicinity of the blazar, we also investigate a reflected-emission model to describe the observed variability pattern. This model assumes that the non-thermal emission from the jet is reflected by a nearby cloud of gas, allowing the reflected emission to re-enter the blob and produce an elevated gamma-ray state with no simultaneous elevated synchrotron flux. The model applied here, although not required to explain the observed variability pattern, represents one possible scenario which can describe the observations. As applied to an elevated VHE state of 66% of the Crab Nebula flux, observed on a single night during the observation period, the reflected-emission scenario does not support a purely leptonic non-thermal emission mechanism. The reflected emission model does, however, predict a reflected photon field with sufficient energy to enable elevated gamma-ray emission via pion production with protons of energies between 10 and 100 TeV., Accepted by ApJ
Published: 2014
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49. Exceptionally Bright TEV Flares from the Binary LS I +61° 303

Author: VERITAS Collaboration, Archambault, S., Archer, A., Aune, T., Barnacka, A., Benbow, W., Bird, R., Buchovecky, M., Buckley, J. H., Bugaev, V., Byrum, K., Cardenzana, J. V., Cerruti, M., Chen, X., Ciupik, L., Collins-Hughes, E., Connolly, M. P., Cui, W., Dickinson, H. J., Dumm, J., Eisch, J. D., Falcone, A., Feng, Q., Finley, J. P., Fleischhack, H., Flinders, A., Fortin, P., Fortson, L., Furniss, A., Gillanders, G. H., Griffin, S., Grube, J., Gyuk, G., Huetten, M., Hakansson, N., Hanna, D., Holder, J., Humensky, T. B., Johnson, C. A., Kaaret, P., Kar, P., Kelley-Hoskins, N., Kertzman, M., Khassen, Y., Kieda, D., Krause, M., Krennrich, F., Kumar, S., Lang, M. J., Maier, G., McArthur, S., McCann, A., Meagher, K., Millis, J., Moriarty, P., Mukherjee, R., Nieto, D., O'Brien, S., de Bhroithe, A. O'Faolain, Ong, R. A., Otte, A. N., Pandel, D., Park, N., Pelassa, V., Pohl, M., Popkow, A., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Richards, G. T., Roache, E., Rousselle, J., Rulten, C., Santander, M., Sembroski, G. H., Shahinyan, K., Smith, A. W., Staszak, D., Telezhinsky, I., Tucci, J. V., Tyler, J., Vincent, S., Wakely, S. P., Weiner, O. M., Weinstein, A., Wilhelm, A., Williams, D. A., and Zitzer, B.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, swift/xrt, FOS: Physical sciences, Binary number, Flux, gamma-ray binaries, Astrophysics, periodicity, Compact star, 01 natural sciences, emission, 0103 physical sciences, +61-degrees-303, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, High Energy Astrophysical Phenomena (astro-ph.HE), parameters, Physics, lsi+61-degrees-303, 010308 nuclear & particles physics, Conjunction (astronomy), stars: individual (ls i+61 degrees 303, ver j0240+612), Astronomy and Astrophysics, fermi-lat, gamma-rays: general, Orbital period, Orbit, Crab Nebula, binaries: general, x-rays: binaries, 13. Climate action, Space and Planetary Science, ddc:520, Astrophysics - High Energy Astrophysical Phenomena
Abstract: The TeV binary system LS I +61$^\circ$ 303 is known for its regular, non-thermal emission pattern which traces the orbital period of the compact object in its 26.5 day orbit around its B0 Ve star companion. The system typically presents elevated TeV emission around apastron passage with flux levels between 5% and 15% of the steady flux from the Crab Nebula (> 300 GeV). In this article, VERITAS observations of LS I +61$^\circ$ 303 taken in late 2014 are presented, during which bright TeV flares around apastron at flux levels peaking above 30% of the Crab Nebula flux were detected. This is the brightest such activity from this source ever seen in the TeV regime. The strong outbursts have rise and fall times of less than a day. The short timescale of the flares, in conjunction with the observation of 10 TeV photons from LS I +61$^\circ$ 303 during the flares, provides constraints on the properties of the accelerator in the source., 9 pages, 2 figures. Accepted for publication by ApJL
Published: 2016
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50. EXCEPTIONALLY BRIGHT TEV FLARES FROM THE BINARY LS I+61 degrees 303

Author: Archambault, S., Archer, A., Aune, T., Barnacka, Anna, Benbow, W., Bird, R., Buchovecky, M., Buckley, J. H., Bugaev, V., Byrum, K., Cardenzana, J. V., Cerruti, M., Chen, Xuhui, Ciupik, L., Collins-Hughes, E., Connolly, M. P., Cui, W., Dickinson, H. J., Dumm, J., Eisch, J. D., Falcone, A., Feng, Q., Finley, J. P., Fleischhack, H., Flinders, A., Fortin, P., Fortson, L., Furniss, A., Gillanders, G. H., Griffin, S., Grube, J., Gyuk, G., Huetten, M., Hakansson, Nils, Hanna, D., Holder, J., Humensky, T. B., Johnson, C. A., Kaaret, P., Kar, P., Kelley-Hoskins, N., Kertzman, M., Khassen, Y., Kieda, D., Krause, M., Krennrich, F., Kumar, S., Lang, M. J., Maier, G., McArthur, S., McCann, A., Meagher, K., Millis, J., Moriarty, P., Mukherjee, R., Nieto, D., Ong, R. A., Otte, A. N., Pandel, D., Park, N., Pelassa, V., Pohl, Martin Karl Wilhelm (Prof. Dr.), Popkow, A., Pueschel, Elisa, Quinn, J., Ragan, K., Reynolds, P. T., Richards, G. T., Roache, E., Rousselle, J., Rulten, C., Santander, M., Sembroski, G. H., Shahinyan, K., Smith, A. W., Staszak, D., Telezhinsky, Igor O., Tucci, J. V., Tyler, J., Vincent, S., Wakely, S. P., Weiner, O. M., Weinstein, A., Wilhelm, Alina, Williams, D. A., and Zitzer, B.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Solar and Stellar Astrophysics, Institut für Physik und Astronomie
Abstract: The TeV binary system LS I +61 degrees 303 is known for its regular, non-thermal emission pattern that traces the orbital period of the compact object in its 26.5 day orbit around its B0 Ve star companion. The system typically presents elevated TeV emission around apastron passage with flux levels between 5% and 15% of the steady flux from the Crab Nebula (> 300 GeV). In this article, VERITAS observations of LS I + 61 degrees. 303 taken in late 2014 are presented, during which bright TeV flares around apastron at flux levels peaking above 30% of the Crab Nebula flux were detected. This is the brightest such activity from this source ever seen in the TeV regime. The strong outbursts have rise and fall times of less than a day. The short timescale of the flares, in conjunction with the observation of 10 TeV photons from LS I + 61 degrees 303 during the flares, provides constraints on the properties of the accelerator in the source.
Published: 2016

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