Research and Publications - Department of Physics & Astronomy

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Browsing Research and Publications - Department of Physics & Astronomy by Author "Abeysekara, A. U."

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    Discovery of Very-high-energy Emission from RGB J2243+203 and Derivation of Its Redshift Upper Limit
    (IOP Publishing, 2017-11-10) Abeysekara, A. U.; Archambault, S.; Archer, A.; Benbow, W.; Bird, R.; Brose, R.; Buchovecky, M.; Buckley, J. H.; Bugaev, V.; Cerruti, M.; Connolly, M. P.; Cui, W.; Falcone, A.; Feng, Q.; Finley, J. P.; Fleischhack, H.; Fortson, L.; Furniss, A.; Gillanders, G. H.; Griffin, S.; Grube, J.; Huetten, M.; Hanna, D.; 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.; 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.; Santander, M.; Sembroski, G. H.; Shahinyan, K.; Staszak, D.; Telezhinsky, I.; Tyler, J.; Vassiliev, V. V.; Wakely, S. P.; Weiner, O. M.; Weinstein, A.; Wilcox, P.; Wilhelm, A.; Williams, D. A.; Zitzer, B.; Utah System of Higher Education; University of Utah; McGill University; Washington University (WUSTL); Harvard University; Smithsonian Institution; University of California System; University of California Los Angeles; University of Potsdam; Helmholtz Association; Deutsches Elektronen-Synchrotron (DESY); Ollscoil na Gaillimhe-University of Galway; Purdue University System; Purdue University; Purdue University West Lafayette Campus; Tsinghua University; Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park; University of Minnesota System; University of Minnesota Twin Cities; California State University System; California State University East Bay; Stevens Institute of Technology; University of California Santa Cruz; University of Delaware; Columbia University; University of Iowa; DePauw University; Iowa State University; University College Dublin; University System of Georgia; Georgia Institute of Technology; University of Chicago; Cork Institute of Technology; University of Alabama Tuscaloosa
    Very-high-energy (VHE; > 100 GeV) gamma-ray emission from the blazar RGB J2243+203 was discovered with the VERITAS Cherenkov telescope array, during the period between 2014 December 21 and 24. The VERITAS energy spectrum from this source can be fitted by a power law with a photon index of 4.6 +/- 0.5, and a flux normalization at 0.15 TeV of (6.3 +/- 1.1) x 10(-10) cm(-2) s(-1) TeV-1. The integrated Fermi-LAT flux from 1 to 100 GeV during the VERITAS detection is (4.1 +/- 0.8) x 10(-8) cm(-2) s(-1), which is an order of magnitude larger than the four-year-averaged flux in the same energy range reported in the 3FGL catalog, (4.0 +/- 0.1 x 10(-9) cm(-2) s(-1)). The detection with VERITAS triggered observations in the X-ray band with the Swift-XRT. However, due to scheduling constraints Swift-XRT observations were performed 67 hr after the VERITAS detection, rather than simultaneously with the VERITAS observations. The observed X-ray energy spectrum between 2 and 10 keV can be fitted with a power law with a spectral index of 2.7 +/- 0.2, and the integrated photon flux in the same energy band is (3.6 +/- 0.6) x 10(-13) cm(-2) s(-1). EBL-model-dependent upper limits of the blazar redshift have been derived. Depending on the EBL model used, the upper limit varies in the range from z < 0.9 to z < 1.1.
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    Multiwavelength follow-up of a rare IceCube neutrino multiplet
    (EDP Sciences, 2017-11-24) 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.; Arguelles, 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.; Boerner, M.; Bos, F.; Bose, D.; Boeser, 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 Andre, J. P. A. M.; De Clercq, C.; Rosendo, E. del Pino; Dembinski, H.; De Ridder, S.; Desiati, P.; de Vries, K. D.; de Wasseige, G.; de With, M.; DeYoung, T.; 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.; Foesig, C. -C.; Franckowiak, A.; Friedman, E.; Fuchs, T.; Gaisser, T. K.; Gallagher, J.; Gerhardt, L.; Ghorbani, K.; Giang, W.; Gladstone, L.; Glauch, T.; Gluesekamp, 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.; Koepke, L.; Kopper, C.; Kopper, S.; Koskinen, D. J.; Kowalski, M.; Krings, K.; Kroll, M.; Krueckl, G.; Krueger, 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.; Luenemann, 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.; Momente, 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, O.; Pepper, J. A.; Perez de los Heros, C.; Pieloth, D.; Pinat, E.; Price, P. B.; Przybylski, G. T.; Quinnan, M.; Raab, C.; Raedel, 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.; Schoeneberg, 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.; Stoessl, A.; Stroem, 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.; 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.; Meszaros, P.; Murase, K.; Kocevski, D.; Buehler, R.; Giomi, M.; Racusin, J. L.; Albert, A.; Alfaro, R.; Alvarez, C.; Alvarez, J. D.; Arceo, R.; Arteaga-Velazquez, J. C.; Solares, H. A. Ayala; Barber, A. S.; Baustista-Elivar, N.; Becerril, A.; Belmont-Moreno, E.; Bernal, A.; Brisbois, C.; Caballero-Mora, K. S.; Capistran, T.; Carraminana, A.; Casanova, S.; Castillo, M.; Cotti, U.; Coutino de Leon, S.; de la Fuente, E.; De Leon, C.; Diaz Hernandez, R.; Diaz-Velez, J. C.; Dingus, B. L.; DuVernois, M. A.; Ellsworth, R. W.; Engel, K.; Fiorino, D. W.; Fraija, N.; Garcia-Gonzalez, J. A.; Gerhardt, M.; Gonzalez Munoz, A.; Gonzalez, M. M.; Goodman, J. A.; Hampel-Arias, Z.; Harding, J. P.; Hernandez, S.; Hui, C. M.; Huentemeyer, P.; Iriarte, A.; Jardin-Blicq, A.; Joshi, V.; Kaufmann, S.; Lara, A.; Lauer, R. J.; Lee, W. H.; Lennarz, D.; Leon Vargas, H.; Linnemann, J. T.; 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.; 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.; 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.; Villasenor, 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.; Huetten, 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.; Trepanier, 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.; RWTH Aachen University; University of Adelaide; University of New Mexico; Harvard University; Smithsonian Institution; Iowa State University; University of Alaska System; University of Alaska Anchorage; Clark Atlanta University; University System of Georgia; Georgia Institute of Technology; Southern University System; Southern University & A&M College; Tsinghua University; University of California System; University of California Berkeley; United States Department of Energy (DOE); Lawrence Berkeley National Laboratory; Humboldt University of Berlin; Ruhr University Bochum; University of Wurzburg; University of Bonn; Universite Libre de Bruxelles; Vrije Universiteit Brussel; Massachusetts Institute of Technology (MIT); Universidad Nacional Autonoma de Mexico; Instituto Politecnico Nacional - Mexico; CINVESTAV - Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional; Universidad Autonoma de Chiapas; Chiba University; University of Chicago; University of Canterbury; University System of Maryland; University of Maryland College Park; University System of Ohio; Ohio State University; University of Copenhagen; Niels Bohr Institute; Cork Institute of Technology; University of California Davis; Dortmund University of Technology; University College Dublin; Michigan State University; University of Alberta; University of Erlangen Nuremberg; George Mason University; Ollscoil na Gaillimhe-University of Galway; University of Geneva; Ghent University; Consejo Superior de Investigaciones Cientificas (CSIC); CSIC - Instituto de Astrofisica de Andalucia (IAA); National Aeronautics & Space Administration (NASA); NASA Goddard Space Flight Center; DePauw University; Universidad de Guadalajara; California State University System; California State University East Bay; Max Planck Society; Stevens Institute of Technology; Michigan Technological University; NASA Marshall Space Flight Center; University of Iowa; Irkutsk State University; Russian Academy of Sciences; Institute of Applied Physics of the Russian Academy of Sciences; University of California Irvine; Pulkovo Observatory; Polish Academy of Sciences; Institute of Nuclear Physics - Polish Academy of Sciences; University of Kansas; University of Leicester; Los Alamos National Laboratory; University of California Los Angeles; University of Wisconsin System; University of Wisconsin Madison; Johannes Gutenberg University of Mainz; Marquette University; University of Minnesota System; University of Minnesota Twin Cities; University of Mons; McGill University; Universidad Michoacana de San Nicolas de Hidalgo; Lomonosov Moscow State University; Technical University of Munich; University of Munster; University of Delaware; Yale University; Columbia University; University of Oxford; Universidad Autonoma del Estado de Hidalgo; Carnegie Institution for Science; California Institute of Technology; Drexel University; University of Potsdam; Instituto Nacional de Astrofisica, Optica y Electronica; Benemerita Universidad Autonoma de Puebla; South Dakota School Mines & Technology; Weizmann Institute of Science; University of Rochester; Utah System of Higher Education; University of Utah; University of California Santa Barbara; University of California Santa Cruz; University Diego Portales; Washington University (WUSTL); Oskar Klein Centre; Stockholm University; State University of New York (SUNY) System; State University of New York (SUNY) Stony Brook; Sungkyunkwan University (SKKU); Instituto de Astrofisica de Canarias; University of Tokyo; University of Toronto; University of Alabama Tuscaloosa; Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park; Uppsala University; Purdue University System; Purdue University; Purdue University West Lafayette Campus; University of Wuppertal; Helmholtz Association; Deutsches Elektronen-Synchrotron (DESY)
    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.
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    A SEARCH FOR BRIEF OPTICAL FLASHES ASSOCIATED WITH THE SETI TARGET KIC 8462852
    (IOP Publishing, 2016-02-18) Abeysekara, A. U.; Archambault, S.; Archer, A.; Benbow, W.; Bird, R.; Buchovecky, M.; Buckley, J. H.; Byrum, K.; Cardenzana, J. V.; Cerruti, M.; Chen, X.; Christiansen, J. L.; Ciupik, L.; Cui, W.; Dickinson, H. J.; Eisch, J. D.; Errando, M.; Falcone, A.; Fegan, D. J.; Feng, Q.; Finley, J. P.; Fleischhack, H.; 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.; Kieda, D.; Krause, M.; Krennrich, F.; Kumar, S.; Lang, M. J.; Lin, T. T. Y.; Maier, G.; McArthur, S.; McCann, A.; Meagher, K.; Moriarty, P.; Mukherjee, R.; Nieto, D.; O'Brien, S.; de Bhroithe, A. O'Faolain; Ong, R. A.; Otte, A. N.; Park, N.; Perkins, J. S.; Petrashyk, A.; Pohl, M.; Popkow, A.; Pueschel, E.; Quinn, J.; Ragan, K.; Ratliff, G.; Reynolds, P. T.; Richards, G. T.; Roache, E.; Santander, M.; Sembroski, G. H.; Shahinyan, K.; Staszak, D.; Telezhinsky, I.; Tucci, J. V.; Tyler, J.; Vincent, S.; Wakely, S. P.; Weiner, O. M.; Weinstein, A.; Williams, D. A.; Zitzer, B.; Utah System of Higher Education; University of Utah; McGill University; Washington University (WUSTL); Harvard University; Smithsonian Institution; University College Dublin; University of California System; University of California Los Angeles; United States Department of Energy (DOE); Argonne National Laboratory; Iowa State University; University of Potsdam; Helmholtz Association; Deutsches Elektronen-Synchrotron (DESY); California State University System; California Polytechnic State University San Luis Obispo; Purdue University System; Purdue University; Purdue University West Lafayette Campus; Columbia University; Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park; University of Minnesota System; University of Minnesota Twin Cities; California State University East Bay; Ollscoil na Gaillimhe-University of Galway; University of Delaware; Florida Institute of Technology; University of California Santa Cruz; University of Iowa; DePauw University; University System of Georgia; Georgia Institute of Technology; University of Chicago; National Aeronautics & Space Administration (NASA); NASA Goddard Space Flight Center; Cork Institute of Technology; University of Alabama Tuscaloosa
    The F-type star KIC. 8462852 has recently been identified as an exceptional target for search for extraterrestrial intelligence (SETI) observations. We describe an analysis methodology for optical SETI, which we have used to analyze nine hours of serendipitous archival observations of KIC. 8462852 made with the VERITAS gamma-ray observatory between 2009 and 2015. No evidence of pulsed optical beacons, above a pulse intensity at the Earth of approximately 1 photon m(-2), is found. We also discuss the potential use of imaging atmospheric Cherenkov telescope arrays in searching for extremely short duration optical transients in general.
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    VERITAS and multiwavelength observations of the BL Lacertae object 1ES 1741+196
    (Oxford University Press, 2016-05-04) Abeysekara, A. U.; Archambault, S.; Archer, A.; Benbow, W.; Bird, R.; Biteau, J.; Buchovecky, M.; Buckley, J. H.; Bugaev, V.; Byrum, K.; Cardenzana, J. V.; Cerruti, M.; Chen, X.; Christiansen, J. L.; 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.; Fortin, P.; Fortson, L.; Furniss, A.; Gillanders, G. H.; Griffin, S.; Grube, J.; Gyuk, G.; Huetten, M.; Hanna, D.; Holder, J.; Humensky, T. B.; Johnson, C. A.; Kaaret, P.; Kar, P.; Kelley-Hoskins, N.; Kertzman, M.; Kieda, D.; Krause, M.; Krennrich, F.; Lang, M. J.; Maier, G.; McArthur, S.; McCann, A.; Meagher, K.; Moriarty, P.; Mukherjee, R.; Nieto, D.; O'Brien, S.; de Bhroithe, A. O'Faolain; Ong, R. A.; Otte, A. N.; Park, N.; Pelassa, V.; Petrashyk, A.; Petry, D.; Pohl, M.; Popkow, A.; Pueschel, E.; Quinn, J.; Ragan, K.; Ratliff, G.; Reyes, L. C.; Reynolds, P. T.; Reynolds, K.; Richards, G. T.; Roache, E.; 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.; Zitzer, B.; Utah System of Higher Education; University of Utah; McGill University; Washington University (WUSTL); Harvard University; Smithsonian Institution; University College Dublin; University of California System; University of California Santa Cruz; University of California Los Angeles; United States Department of Energy (DOE); Argonne National Laboratory; Iowa State University; University of Potsdam; Helmholtz Association; Deutsches Elektronen-Synchrotron (DESY); California State University System; California Polytechnic State University San Luis Obispo; Purdue University System; Purdue University; Purdue University West Lafayette Campus; University of Minnesota System; University of Minnesota Twin Cities; Columbia University; Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park; California State University East Bay; University of Delaware; University of Iowa; DePauw University; University System of Georgia; Georgia Institute of Technology; University of Chicago; National Aeronautics & Space Administration (NASA); NASA Goddard Space Flight Center; University System of Maryland; University of Maryland College Park; University of Alabama Tuscaloosa
    We present results from multiwavelength observations of the BL Lacertae object 1ES 1741 + 196, including results in the very high energy gamma-ray regime using the Very Energetic Radiation Imaging Telescope Array System (VERITAS). The VERITAS time-averaged spectrum, measured above 180 GeV, is well modelled by a power law with a spectral index of 2.7 +/- 0.7(stat) +/- 0.2(syst). The integral flux above 180 GeV is (3.9 +/- 0.8(stat) +/- 1.0(syst)) x 10(-8) m(-2) s(-1), corresponding to 1.6 per cent of the Crab nebula flux on average. The multiwavelength spectral energy distribution of the source suggests that 1ES 1741+196 is an extreme-high-frequency-peaked BL Lacertae object. The observations analysed in this paper extend over a period of six years, during which time no strong flares were observed in any band. This analysis is therefore one of the few characterizations of a blazar in a non-flaring state.
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    A Very High Energy gamma-Ray Survey toward the Cygnus Region of the Galaxy
    (IOP Publishing, 2018-07-12) 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, 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.; Zitzer, B.; Utah System of Higher Education; University of Utah; Washington University (WUSTL); University of California System; University of California Los Angeles; Harvard University; Smithsonian Institution; University of Potsdam; Helmholtz Association; Deutsches Elektronen-Synchrotron (DESY); Purdue University System; Purdue University; Purdue University West Lafayette Campus; Tsinghua University; Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park; McGill University; University of Minnesota System; University of Minnesota Twin Cities; California State University System; California State University East Bay; Columbia University; Stevens Institute of Technology; University of California Santa Cruz; University of Delaware; University of Iowa; DePauw University; Ollscoil na Gaillimhe-University of Galway; University College Dublin; University System of Georgia; Georgia Institute of Technology; Grand Valley State University; University of Chicago; University of Hawaii System; University of Hawaii Manoa; Cork Institute of Technology; Autonomous University of Barcelona; Barcelona Institute of Science & Technology; Institute for High Energy Physics (IFAE); Iowa State University; University of Alabama Tuscaloosa
    We present results from deep observations toward the Cygnus region using 300 hr of very high energy (VHE)gamma-ray data taken with the VERITAS Cerenkov telescope array and over 7 yr of high-energy.-ray data taken with the Fermi satellite at an energy above 1 GeV. As the brightest region of diffuse gamma-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 gamma-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 gamma-ray view of the region to date.