@article{AcciariAliuArlenetal.2011,
  author    = {Acciari, V. A. and Aliu, E. and Arlen, T. and Aune, T. and Beilicke, M. and Benbow, W. and Bradbury, S. M. and Buckley, J. H. and Bugaev, V. and Byrum, K. and Cannon, A. and Cesarini, A. and Ciupik, L. and Collins-Hughes, E. and Connolly, M. P. and Cui, W. and Dickherber, R. and Duke, C. and Errando, M. and Falcone, A. and Finley, J. P. and Finnegan, G. and Fortson, L. and Furniss, A. and Galante, N. and Gall, D. and Gillanders, G. H. and Godambe, S. and Griffin, S. and Grube, J. and Guenette, R. and Gyuk, G. and Hanna, D. and Holder, J. and Hughes, G. and Hui, C. M. and Humensky, T. B. and Kaaret, P. and Karlsson, N. and Kertzman, M. and Kieda, D. and Krawczynski, H. and Krennrich, F. and Lang, M. J. and LeBohec, S. and Maier, G. and Majumdar, P. and McArthur, S. and McCann, A. and Moriarty, P. and Mukherjee, R. and Ong, R. A. and Orr, M. and Otte, A. N. and Park, N. and Perkins, J. S. and Pohl, Martin and Prokoph, H. and Quinn, J. and Ragan, K. and Reyes, L. C. and Reynolds, P. T. and Roache, E. and Rose, H. J. and Ruppel, J. and Saxon, D. B. and Schroedter, M. and Sembroski, G. H. and Senturk, G. D. and Smith, A. W. and Staszak, D. and Tesic, G. and Theiling, M. and Thibadeau, S. and Tsurusaki, K. and Varlotta, A. and Vassiliev, V. V. and Vincent, S. and Vivier, M. and Wakely, S. P. and Ward, J. E. and Weekes, T. C. and Weinstein, A. and Weisgarber, T. and Williams, D. A. and Zitzer, B.},
  title     = {VERITAS OBSERVATIONS OF THE TeV BINARY LS I+61 degrees 303 DURING 2008-2010},
  series = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  volume    = {738},
  journal   = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  number    = {1},
  publisher = {IOP Publ. Ltd.},
  address   = {Bristol},
  issn      = {0004-637X},
  doi       = {10.1088/0004-637X/738/1/3},
  pages     = {8},
  year      = {2011},
  abstract  = {We present the results of observations of the TeV binary LS I + 61 degrees 303 with the VERITAS telescope array between 2008 and 2010, at energies above 300 GeV. In the past, both ground-based gamma-ray telescopes VERITAS and MAGIC have reported detections of TeV emission near the apastron phases of the binary orbit. The observations presented here show no strong evidence for TeV emission during these orbital phases; however, during observations taken in late 2010, significant emission was detected from the source close to the phase of superior conjunction (much closer to periastron passage) at a 5.6 standard deviation (5.6 sigma) post-trials significance. In total, between 2008 October and 2010 December a total exposure of 64.5 hr was accumulated with VERITAS on LS I + 61 degrees 303, resulting in an excess at the 3.3 sigma significance level for constant emission over the entire integrated data set. The flux upper limits derived for emission during the previously reliably active TeV phases (i.e., close to apastron) are less than 5\% of the Crab Nebula flux in the same energy range. This result stands in apparent contrast to previous observations by both MAGIC and VERITAS which detected the source during these phases at 10\% of the Crab Nebula flux. During the two year span of observations, a large amount of X-ray data were also accrued on LS I + 61 degrees 303 by the Swift X-ray Telescope and the Rossi X-ray Timing Explorer Proportional Counter Array. We find no evidence for a correlation between emission in the X-ray and TeV regimes during 20 directly overlapping observations. We also comment on data obtained contemporaneously by the Fermi Large Area Telescope.},
  language  = {en}
}
@article{AbdallaAharonianAitBenkhalietal.2018,
  author    = {Abdalla, Hassan E. and Aharonian, Felix A. and Ait Benkhali, Faical and Ang{\"u}ner, Ekrem Oǧuzhan and Arakawa, M. and Arcaro, C. and Armand, C. and Arrieta, M. and Backes, Michael and Barnard, M. and Becherini, Yvonne and Tjus, J. Becker and Berge, D. and Bernhard, S. and Bernl{\"o}hr, Konrad and Blackwell, R. and B{\"o}ttcher, Markus and Boisson, C. and Bolmont, Julien and Bonnefoy, S. and Bordas, Pol and Bregeon, J. and Brun, F. and Brun, P. and Bryan, M. and B{\"u}chele, M. and Bulik, Tomasz and Bylund, Tomas and Capasso, Massimo and Caroff, S. and Carosi, A. and Casanova, Sabrina and Cerruti, Matteo and Chakraborty, Nachiketa and Chandra, S. and Chaves, R. C. G. and Chen, A. and Colafrancesco, Sergio and Condon, B. and Davids, Isak and Deil, Christoph and Devin, J. and deWilt, P. and Dirson, L. and Djannati-Atai, A. and Dmytriiev, A. and Donath, Axel and Doroshenko, Victor and Dyks, J. and Egberts, Kathrin and Emery, G. and Ernenwein, J. -P. and Eschbach, Stefan and Fegan, S. and Fiasson, Armand and Fontaine, G. and Funk, Sebastian and F{\"u}ßling, Matthias and Gabici, S. and Gallant, Y. A. and Gate, F. and Giavitto, Gianluca and Eisenacher Glawion, Dorit and Glicenstein, Jean-Fran{\c{c}}ois and Gottschall, D. and Grondin, Marie-H{\´e}l{\`e}ne and Hahn, J. and Haupt, M. and Heinzelmann, G. and Henri, Gilles and Hermann, G. and Hinton, James Anthony and Hofmann, Werner and Hoischen, Clemens and Holch, Tim Lukas and Holler, M. and Horns, D. and Huber, D. and Iwasaki, H. and Jacholkowska, A. and Jamrozy, M. and Jankowsky, David and Jankowsky, Felix and Jouvin, L. and Jung-Richardt, I. and Kastendieck, M. A. and Katarzyński, Krzysztof and Katsuragawa, M. and Katz, U. and Kerszberg, D. and Khangulyan, D. and Khelifi, B. and King, J. and Klepser, S. and Kluzniak, W. and Komin, Nu. and Kosack, K. and Krakau, S. and Kraus, M. and Kruger, P. P. and Lamanna, G. and Lau, J. and Lefaucheur, J. and Lemiere, A. and Lemoine-Goumard, M. and Lenain, J. -P. and Leser, Eva and Lohse, T. and Lorentz, M. and Lopez-Coto, R. and Lypova, I. and Malyshev, D. and Marandon, V. and Marcowith, Alexandre and Mariaud, C. and Marti-Devesa, G. and Marx, R. and Maurin, G. and Meintjes, P. J. and Mitchell, A. M. W. and Moderski, R. and Mohamed, M. and Mohrmann, L. and Moulin, Emmanuel and Murach, T. and Nakashima, S. and de Naurois, M. and Ndiyavala, H. and Niederwanger, F. and Niemiec, J. and Oakes, L. and Odaka, H. and Ohm, S. and Ostrowski, M. and Oya, I. and Padovani, M. and Panter, M. and Parsons, R. D. and Perennes, C. and Petrucci, P. -O. and Peyaud, B. and Piel, Q. and Pita, S. and Poireau, V. and Noel, A. Priyana and Prokhorov, D. A. and Prokoph, H. and Puehlhofer, G. and Punch, M. and Quirrenbach, A. and Raab, S. and Rauth, R. and Reimer, A. and Reimer, O. and Renaud, M. and Rieger, F. and Rinchiuso, L. and Romoli, C. and Rowell, G. and Rudak, B. and Ruiz-Velasco, E. and Sahakian, V. and Saito, S. and Sanchez, D. A. and Santangelo, Andrea and Sasaki, M. and Schlickeiser, R. and Schussler, F. and Schulz, A. and Schwanke, U. and Schwemmer, S. and Seglar-Arroyo, M. and Senniappan, M. and Seyffert, A. S. and Shafi, N. and Shilon, I. and Shiningayamwe, K. and Simoni, R. and Sinha, A. and Sol, H. and Spanier, F. and Specovius, A. and Spir-Jacob, M. and Stawarz, L. and Steenkamp, R. and Stegmann, Christian and Steppa, Constantin Beverly and Takahashi, T. and Tavernet, J. -P. and Tavernier, T. and Taylor, A. M. and Terrier, R. and Tibaldo, L. and Tiziani, D. and Tluczykont, M. and Trichard, C. and Tsirou, M. and Tsuji, N. and Tuffs, R. and Uchiyama, Y. and van der Walt, D. J. and van Eldik, C. and van Rensburg, C. and van Soelen, B. and Vasileiadis, G. and Veh, J. and Venter, C. and Viana, A. and Vincent, P. and Vink, J. and Voisin, F. and Voelk, H. J. and Vuillaume, T. and Wadiasingh, Z. and Wagner, S. J. and Wagner, R. M. and White, R. and Wierzcholska, A. and Yang, R. and Zaborov, D. and Zacharias, M. and Zanin, R. and Zdziarski, A. and Zech, Alraune and Zefi, F. and Ziegler, A. and Zorn, J. and Zywucka, N. and Cirelli, M. and Panci, P. and Sala, F. and Silk, J. and Taoso, M.},
  title     = {Searches for gamma-ray lines and 'pure WIMP' spectra from Dark Matter annihilations in dwarf galaxies with H.E.S.S.},
  series = {Journal of cosmology and astroparticle physics},
  journal   = {Journal of cosmology and astroparticle physics},
  number    = {11},
  publisher = {IOP Publishing Ltd. (Bristol)},
  address   = {Bristol},
  organization    = {HESS Collaboration},
  issn      = {1475-7516},
  doi       = {10.1088/1475-7516/2018/11/037},
  pages     = {22},
  year      = {2018},
  abstract  = {Dwarf spheroidal galaxies are among the most promising targets for detecting signals of Dark Matter (DM) annihilations. The H.E.S.S. experiment has observed five of these systems for a total of about 130 hours. The data are re-analyzed here, and, in the absence of any detected signals, are interpreted in terms of limits on the DM annihilation cross section. Two scenarios are considered: i) DM annihilation into mono-energetic gamma-rays and ii) DM in the form of pure WIMP multiplets that, annihilating into all electroweak bosons, produce a distinctive gamma-ray spectral shape with a high-energy peak at the DM mass and a lower-energy continuum. For case i), upper limits at 95\% confidence level of about <sigma upsilon > less than or similar to 3 x 10(-25) cm(3) s(-1) are obtained in the mass range of 400 GeV to 1TeV. For case ii), the full spectral shape of the models is used and several excluded regions are identified, but the thermal masses of the candidates are not robustly ruled out.},
  language  = {en}
}
@article{AliuArchambaultArlenetal.2013,
  author    = {Aliu, E. and Archambault, S. and Arlen, T. and Aune, T. and Beilicke, M. and Benbow, W. and Bouvier, A. and Buckley, J. H. and Bugaev, V. and Cesarini, A. and Ciupik, L. and Collins-Hughes, E. and Connolly, M. P. and Cui, W. and Dickherber, R. and Duke, C. and Dumm, J. and Dwarkadas, Vikram V. and Errando, M. and Falcone, A. and Federici, S. and Feng, Q. and Finley, J. P. and Finnegan, G. and Fortson, L. and Furniss, A. and Galante, N. and Gall, D. and Gillanders, G. H. and Godambe, S. and Gotthelf, E. V. and Griffin, S. and Grube, J. and Gyuk, G. and Hanna, D. and Holder, J. and Hughes, G. and Humensky, T. B. and Kaaret, P. and Kargaltsev, O. and Karlsson, N. and Khassen, Y. and Kieda, D. and Krawczynski, H. and Krennrich, F. and Lang, M. J. and Lee, K. and Madhavan, A. S. and Maier, G. and Majumdar, P. and McArthur, S. and McCann, A. and Moriarty, P. and Mukherjee, R. and Nelson, T. and de Bhroithe, A. O\&rsquo and Faolain, and Ong, R. A. and Orr, M. and Otte, A. N. and Park, N. and Perkins, J. S. and Pohl, M. and Prokoph, H. and Quinn, J. and Ragan, K. and Reyes, L. C. and Reynolds, P. T. and Roache, E. and Roberts, M. and Saxon, D. B. and Schroedter, M. and Sembroski, G. H. and Slane, P. and Smith, A. W. and Staszak, D. and Telezhinsky, Igor O. and Tesic, G. and Theiling, M. and Thibadeau, S. and Tsurusaki, K. and Tyler, J. and Varlotta, A. and Vassiliev, V. V. and Vincent, S. and Vivier, M. and Wakely, S. P. and Weekes, T. C. and Weinstein, A. and Welsing, R. and Williams, D. A. and Zitzer, B.},
  title     = {DISCOVERY OF TeV GAMMA-RAY EMISSION FROM CTA 1 BY VERITAS},
  series = {ASTROPHYSICAL JOURNAL},
  volume    = {764},
  journal   = {ASTROPHYSICAL JOURNAL},
  number    = {1},
  publisher = {IOP PUBLISHING LTD},
  address   = {BRISTOL},
  issn      = {0004-637X},
  doi       = {10.1088/0004-637X/764/1/38},
  pages     = {9},
  year      = {2013},
  abstract  = {We report the discovery of TeV gamma-ray emission coincident with the shell-type radio supernova remnant (SNR) CTA 1 using the VERITAS gamma-ray observatory. The source, VER J0006+729, was detected as a 6.5 standard deviation excess over background and shows an extended morphology, approximated by a two-dimensional Gaussian of semimajor (semiminor) axis 0.degrees 30 (0.degrees 24) and a centroid 5\&rsquo; from the Fermi gamma-ray pulsar PSR J0007+7303 and its X-ray pulsar wind nebula (PWN). The photon spectrum is well described by a power-law dN/dE = N-0(E/3 TeV)(-Gamma), with a differential spectral index of Gamma = 2.2 +/- 0.2(stat) +/- 0.3(sys), and normalization N-0 = (9.1 +/- 1.3(stat) +/- 1.7(sys)) x 10(-14) cm(-2) s(-1) TeV-1. The integral flux, F-gamma = 4.0 x 10(-12) erg cm(-2) s(-1) above 1 TeV, corresponds to 0.2\% of the pulsar spin-down power at 1.4 kpc. The energetics, colocation with the SNR, and the relatively small extent of the TeV emission strongly argue for the PWN origin of the TeV photons. We consider the origin of the TeV emission in CTA 1.},
  language  = {en}
}
@article{AliuAuneBeheraetal.2014,
  author    = {Aliu, E. and Aune, T. and Behera, B. and Beilicke, M. and Benbow, W. and Berger, K. and Bird, R. and Buckley, J. H. and Bugaev, V. and Cardenzana, J. V. and Cerruti, M. and Chen, X. and Ciupik, L. and Connolly, M. P. and Cui, W. and Duke, C. and Dumm, J. and Errando, M. and Falcone, A. and Federici, Simone and Feng, Q. and Finley, J. P. and Fortin, P. and Fortson, L. and Furniss, A. and Galante, N. and Gillanders, G. H. and Griffin, S. and Griffiths, S. T. and Grube, J. and Gyuk, G. and Hanna, D. and Holder, J. and Hughes, G. and Humensky, T. B. and Kaaret, P. and Kargaltsev, Oleg and Kertzman, M. and Khassen, Y. and Kieda, D. and Krawczynski, H. and Lang, M. J. and Madhavan, A. S. and Maier, G. and Majumdar, P. and McCann, A. and Moriarty, P. and Mukherjee, R. and Nieto, D. and Ong, R. A. and Otte, A. N. and Pandel, D. and Perkins, J. S. and Pohl, Manuela and Popkow, A. and Prokoph, H. and Quinn, J. and Ragan, K. and Rajotte, J. and Reyes, L. C. and Reynolds, P. T. and Richards, G. T. and Roache, E. and Sembroski, G. H. and Skole, C. and Staszak, D. and Telezhinsky, Igor O. and Theiling, M. and Tucci, J. V. and Tyler, J. and Varlotta, A. and Vincent, S. and Wakely, S. P. and Weekes, T. C. and Weinstein, A. and Welsing, R. and Williams, D. A. and Zitzer, B.},
  title     = {Observations of the unidentified gamm-ray source TeV J2032+4130 BY Veritas},
  series = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  volume    = {783},
  journal   = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  number    = {1},
  publisher = {IOP Publ. Ltd.},
  address   = {Bristol},
  issn      = {0004-637X},
  doi       = {10.1088/0004-637X/783/1/16},
  pages     = {9},
  year      = {2014},
  language  = {en}
}
@article{OrientiFinkeRaiterietal.2015,
  author    = {Orienti, M. and Finke, J. and Raiteri, C. M. and Hovatta, T. and Larsson, J. and Max-Moerbeck, W. and Perkins, J. and Readhead, A. C. S. and Richards, J. L. and Beilicke, M. and Benbow, W. and Berger, K. and Bird, R. and Bugaev, V. and Cardenzana, J. V. and Cerruti, M. and Chen, Xuhui and Ciupik, L. and Dickinson, H. J. and Eisch, J. D. and Errando, M. and Falcone, A. and Finley, J. P. and Fleischhack, H. and Fortin, P. and Fortson, L. and Furniss, A. and Gerard, L. and Gillanders, G. H. and Griffiths, S. T. and Grube, J. and Gyuk, G. and Hakansson, Nils and Holder, J. and Humensky, T. B. and Kar, P. and Kertzman, M. and Khassen, Y. and Kieda, D. and Krennrich, F. and Kumar, S. and Lang, M. J. and Maier, G. and McCann, A. and Meagher, K. and Moriarty, P. and Mukherjee, R. and Nieto, D. and Ong, R. A. and Otte, A. N. and Pohl, Manuela and Popkow, A. and Prokoph, H. and Pueschel, Elisa and Quinn, J. and Ragan, K. and Reynolds, P. T. and Richards, G. T. and Roache, E. and Rousselle, J. and Santander, M. and Sembroski, G. H. and Smith, A. W. and Staszak, D. and Telezhinsky, Igor O. and Tucci, J. V. and Tyler, J. and Varlotta, A. and Vassiliev, V. V. and Wakely, S. P. and Weinstein, A. and Welsing, R. and Williams, D. A. and Zitzer, B.},
  title     = {The most powerful flaring activity from the NLSyl PMN J0948+0022},
  series = {Monthly notices of the Royal Astronomical Society},
  volume    = {446},
  journal   = {Monthly notices of the Royal Astronomical Society},
  number    = {3},
  publisher = {Oxford Univ. Press},
  address   = {Oxford},
  organization    = {VERITAS Collaboration},
  issn      = {0035-8711},
  doi       = {10.1093/mnras/stu2251},
  pages     = {2456 -- 2467},
  year      = {2015},
  abstract  = {We report on multifrequency observations performed during 2012 December-2013 August of the first narrow-line Seyfert 1 galaxy detected in gamma-rays, PMN J0948+0022 (z = 0.5846). A y -ray flare was observed by the Large Area Telescope on board Fermi during 2012 December-2013 January, reaching a daily peak flux in the 0.1-100 GeV energy range of (155 31) x 10 8 ph cm(-2) S-1 on 2013 January 1, corresponding to an apparent isotropic luminosity of similar to 1.5 x 1048 erg s(-1). The y -ray flaring period triggered Swift and Very Energetic Radiation Imaging Telescope Array System (VERITAS) observations in addition to radio and optical monitoring by Owens Valley Radio Observatory, Monitoring Of Jets in Active galactic nuclei with VLBA Experiments, and Catalina Real-time Transient Survey. A strong flare was observed in optical, UV, and X-rays on 2012 December 30, quasi-simultaneously to the y -ray flare, reaching a record flux for this source from optical to y gamma-rays. VERITAS observations at very high energy (E > 100 GeV) during 2013 January 6-17 resulted in an upper limit of F>0.2 Trev < 4.0 x 10(-12) ph cm(-2) s(-1). We compared the spectral energy distribution (SED) of the flaring state in 2013 January with that of an intermediate state observed in 2011. The two SEDs, modelled as synchrotron emission and an external Compton scattering of seed photons from a dust torus, can be modelled by changing both the electron distribution parameters and the magnetic field.},
  language  = {en}
}
@article{ArchambaultArlenAuneetal.2014,
  author    = {Archambault, S. and Arlen, T. and Aune, T. and Beilicke, M. and Benbow, W. and Bird, R. and Boettcher, Markus and Bouvier, A. and Buckley, J. H. and Bugaev, V. and Ciupik, L. and Collins-Hughes, E. and Connolly, M. P. and Cui, W. and Dickherber, R. and Dumm, J. and Errando, M. and Falcone, A. and Federici, Simone and Feng, Q. and Finley, J. P. and Fortson, L. and Furniss, A. and Galante, N. and Gall, D. and Garson, A. III. and Gillanders, G. H. and Griffin, S. and Grube, J. and Gusbar, C. and Gyuk, G. and Hanna, D. and Holder, J. and Hughes, G. and Kaaret, P. and Kertzman, M. and Khassen, Y. and Kieda, D. and Krawczynski, H. and Lamerato, A. and Lang, M. J. and Li, K. and Madhavan, A. S. and Maier, G. and Majumdar, P. and McArthur, S. and McCann, A. and Millis, J. and Moriarty, P. and Mukherjee, R. and Nieto, D. and Ong, R. A. and Orr, M. and Otte, A. N. and Park, N. and Perkins, J. S. and Pohl, Martin and Popkow, A. and Prokoph, H. and Quinn, J. and Ragan, K. and Reynolds, P. T. and Richards, G. T. and Roache, E. and Roustazadeh, P. and Saxon, D. B. and Sembroski, G. H. and Senturk, G. D. and Skole, C. and Staszak, D. and Telezhinsky, Igor O. and Tesic, G. and Theiling, M. and Varlotta, A. and Vassiliev, V. V. and Vincent, S. and Wakely, S. P. and Weinstein, A. and Welsing, R. and Williams, D. A. and Zitzer, B.},
  title     = {Test of models of the cosmic infrared background with multiwavelength observations of the blazar 1ES 1218+30.4 IN 2009},
  series = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  volume    = {788},
  journal   = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  number    = {2},
  publisher = {IOP Publ. Ltd.},
  address   = {Bristol},
  issn      = {0004-637X},
  doi       = {10.1088/0004-637X/788/2/158},
  pages     = {9},
  year      = {2014},
  abstract  = {We present the results of a multi-wavelength campaign targeting the blazar 1ES 1218+30.4 with observations with the 1.3 m McGraw-Hill optical telescope, the Rossi X-ray Timing Explorer (RXTE), the Fermi Gamma-Ray Space Telescope, and the Very Energetic Radiation Imaging Telescope Array System (VERITAS). The RXTE and VERITAS observations were spread over a 13 day period and revealed clear evidence for flux variability, and a strong X-ray and gamma-ray flare on 2009 February 26 (MJD 54888). The campaign delivered a well-sampled broadband energy spectrum with simultaneous RXTE and VERITAS very high energy (VHE, > 100 GeV) observations, as well as contemporaneous optical and Fermi observations. The 1ES 1218+30.4 broadband energy spectrum-the first with simultaneous X-ray and VHE gamma-ray energy spectra-is of particular interest as the source is located at a high cosmological redshift for a VHE source (z = 0.182), leading to strong absorption of VHE gamma rays by photons from the optical/infrared extragalactic background light (EBL) via gamma VHE +gamma EBL -> e(+) e(-)pair-creation processes. We model the data with a one-zone synchrotron self-Compton (SSC) emission model and with the extragalactic absorption predicted by several recent EBL models. We find that the observations are consistent with the SSC scenario and all the EBL models considered in this work. We discuss observational and theoretical avenues to improve on the EBL constraints.},
  language  = {en}
}
@article{AcciariAliuArayaetal.2011,
  author    = {Acciari, V. A. and Aliu, E. and Araya, M. and Arlen, T. and Aune, T. and Beilicke, M. and Benbow, W. and Bradbury, S. M. and Buckley, J. H. and Bugaev, V. and Byrum, K. and Cannon, A. and Cesarini, A. and Ciupik, L. and Collins-Hughes, E. and Cui, W. and Dickherber, R. and Duke, C. and Falcone, A. and Finley, J. P. and Fortson, L. and Furniss, A. and Galante, N. and Gall, D. and Godambe, S. and Griffin, S. and Guenette, R. and Gyuk, G. and Hanna, D. and Holder, J. and Hughes, G. and Hui, C. M. and Humensky, T. B. and Imran, A. and Kaaret, P. and Kertzman, M. and Krawczynski, H. and Krennrich, F. and Madhavan, A. S. and Maier, G. and Majumdar, P. and McArthur, S. and Moriarty, P. and Ong, R. A. and Otte, A. N. and Pandel, D. and Park, N. and Perkins, J. S. and Pohl, Martin and Prokoph, H. and Quinn, J. and Ragan, K. and Reyes, L. C. and Reynolds, P. T. and Roache, E. and Rose, H. J. and Saxon, D. B. and Sembroski, G. H. and Sentuerk, G. D. and Smith, A. W. and Tesic, G. and Theiling, M. and Thibadeau, S. and Varlotta, A. and Vincent, S. and Vivier, M. and Wakely, S. P. and Ward, J. E. and Weekes, T. C. and Weinstein, A. and Weisgarber, T. and Weng, S. and Williams, D. A. and Wood, M. and Zitzer, B.},
  title     = {Gamma-ray observations of the Be/Pulsar binary 1A 0535+262 during a Giant X-Ray outburst},
  series = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  volume    = {733},
  journal   = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  number    = {2},
  publisher = {IOP Publ. Ltd.},
  address   = {Bristol},
  issn      = {0004-637X},
  doi       = {10.1088/0004-637X/733/2/96},
  pages     = {10},
  year      = {2011},
  abstract  = {Giant X-ray outbursts, with luminosities of about 10(37) erg s(-1), are observed roughly every five years from the nearby Be/pulsar binary 1A 0535+262. In this article, we present observations of the source with VERITAS at very high energies (VHEs; E > 100 GeV) triggered by the X-ray outburst in 2009 December. The observations started shortly after the onset of the outburst and provided comprehensive coverage of the episode, as well as the 111 day binary orbit. No VHE emission is evident at any time. We also examined data from the contemporaneous observations of 1A 0535+262 with the Fermi/Large Area Telescope at high-energy photons (E > 0.1 GeV) and failed to detect the source at GeV energies. The X-ray continua measured with the Swift/X-Ray Telescope and the RXTE/PCA can be well described by the combination of blackbody and Comptonized emission from thermal electrons. Therefore, the gamma-ray and X-ray observations suggest the absence of a significant population of non-thermal particles in the system. This distinguishes 1A 0535+262 from those Be X-ray binaries (such as PSR B1259-63 and LS I +61 degrees 303) that have been detected at GeV-TeV energies. We discuss the implications of the results on theoretical models.},
  language  = {en}
}
@article{AcciariAliuArlenetal.2011,
  author    = {Acciari, V. A. and Aliu, E. and Arlen, T. and Aune, T. and Beilicke, M. and Benbow, W. and Bradbury, S. M. and Buckley, J. H. and Bugaev, V. and Byrum, K. and Cannon, A. and Cesarini, A. and Christiansen, J. L. and Ciupik, L. and Collins-Hughes, E. and Connolly, M. P. and Cui, W. and Duke, C. and Errando, M. and Falcone, A. and Finley, J. P. and Finnegan, G. and Fortson, L. and Furniss, A. and Galante, N. and Gall, D. and Godambe, S. and Griffin, S. and Grube, J. and Guenette, R. and Gyuk, G. and Hanna, D. and Holder, J. and Hughes, G. and Hui, C. M. and Humensky, T. B. and Jackson, D. J. and Kaaret, P. and Karlsson, N. and Kertzman, M. and Kieda, D. and Krawczynski, H. and Krennrich, F. and Lang, M. J. and Madhavan, A. S. and Maier, G. and McArthur, S. and McCann, A. and Moriarty, P. and Newbold, M. D. and Ong, R. A. and Orr, M. and Otte, A. N. and Park, N. and Perkins, J. S. and Pohl, Martin and Prokoph, H. and Quinn, J. and Ragan, K. and Reyes, L. C. and Reynolds, P. T. and Roache, E. and Rose, H. J. and Ruppel, J. and Saxon, D. B. and Schroedter, M. and Sembroski, G. H. and Sentuerk, G. D. and Smith, A. W. and Staszak, D. and Swordy, S. P. and Tesic, G. and Theiling, M. and Thibadeau, S. and Tsurusaki, K. and Varlotta, A. and Vassiliev, V. V. and Vincent, S. and Vivier, M. and Wakely, S. P. and Ward, J. E. and Weekes, T. C. and Weinstein, A. and Weisgarber, T. and Williams, D. A. and Wood, M.},
  title     = {Veritas observations of gamma-ray bursts detected by swift},
  series = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  volume    = {743},
  journal   = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  number    = {1},
  publisher = {IOP Publ. Ltd.},
  address   = {Bristol},
  issn      = {0004-637X},
  doi       = {10.1088/0004-637X/743/1/62},
  pages     = {10},
  year      = {2011},
  abstract  = {We present the results of 16 Swift-triggered Gamma-ray burst (GRB) follow-up observations taken with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) telescope array from 2007 January to 2009 June. The median energy threshold and response time of these observations were 260 GeV and 320 s, respectively. Observations had an average duration of 90 minutes. Each burst is analyzed independently in two modes: over the whole duration of the observations and again over a shorter timescale determined by the maximum VERITAS sensitivity to a burst with a t(-1.5) time profile. This temporal model is characteristic of GRB afterglows with high-energy, long-lived emission that have been detected by the Large Area Telescope on board the Fermi satellite. No significant very high energy (VHE) gamma-ray emission was detected and upper limits above the VERITAS threshold energy are calculated. The VERITAS upper limits are corrected for gamma-ray extinction by the extragalactic background light and interpreted in the context of the keV emission detected by Swift. For some bursts the VHE emission must have less power than the keV emission, placing constraints on inverse Compton models of VHE emission.},
  language  = {en}
}
@article{ArchambaultArlenAuneetal.2013,
  author    = {Archambault, S. and Arlen, T. and Aune, T. and Behera, B. and Beilicke, M. and Benbow, W. and Bird, R. and Bouvier, A. and Buckley, J. H. and Bugaev, V. and Byrum, K. and Cesarini, A. and Ciupik, L. and Connolly, M. P. and Cui, W. and Errando, M. and Falcone, A. and Federici, Simone and Feng, Q. and Finley, J. P. and Fortson, L. and Furniss, A. and Galante, N. and Gall, D. and Gillanders, G. H. and Griffin, S. and Grube, J. and Gyuk, G. and Hanna, D. and Holder, J. and Hughes, G. and Humensky, T. B. and Kaaret, P. and Kertzman, M. and Khassen, Y. and Kieda, D. and Krawczynski, H. and Krennrich, F. and Kumar, S. and Lang, M. J. and Madhavan, A. S. and Maier, G. and Majumdar, P. and McArthur, S. and McCann, A. and Millis, J. and Moriarty, P. and Mukherjee, R. and de Bhroithe, A. O'Faolain and Ong, R. A. and Otte, A. N. and Park, N. and Perkins, J. S. and Pohl, Martin and Popkow, A. and Prokoph, H. and Quinn, J. and Ragan, K. and Reyes, L. C. and Reynolds, P. T. and Richards, G. T. and Roache, E. and Saxon, D. B. and Sembroski, G. H. and Smith, A. W. and Staszak, D. and Telezhinsky, Igor O. and Theiling, M. and Varlotta, A. and Vassiliev, V. V. and Vincent, S. and Wakely, S. P. and Weekes, T. C. and Weinstein, A. and Welsing, R. and Williams, D. A. and Zitzer, B. and Boettcher, Markus and Fegan, S. J. and Fortin, P. and Halpern, J. P. and Kovalev, Y. Y. and Lister, M. L. and Liu, J. and Pushkarev, A. B. and Smith, P. S.},
  title     = {Discovery of a new tev Gamma-Ray source - VER J0521+211},
  series = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  volume    = {776},
  journal   = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  number    = {2},
  publisher = {IOP Publ. Ltd.},
  address   = {Bristol},
  organization    = {VERITAS Collaboration},
  issn      = {0004-637X},
  doi       = {10.1088/0004-637X/776/2/69},
  pages     = {10},
  year      = {2013},
  abstract  = {We report the detection of a new TeV gamma-ray source, VER J0521+211, based on observations made with the VERITAS imaging atmospheric Cherenkov Telescope Array. These observations were motivated by the discovery of a cluster of >30 GeV photons in the first year of Fermi Large Area Telescope observations. VER J0521+211 is relatively bright at TeV energies, with a mean photon flux of (1.93 +/- 0.13(stat) +/- 0.78(sys)) x 10(-11) cm(-2) s(-1) above 0.2 TeV during the period of the VERITAS observations. The source is strongly variable on a daily timescale across all wavebands, from optical to TeV, with a peak flux corresponding to similar to 0.3 times the steady Crab Nebula flux at TeV energies. Follow-up observations in the optical and X-ray bands classify the newly discovered TeV source as a BL Lac-type blazar with uncertain redshift, although recent measurements suggest z = 0.108. VER J0521+211 exhibits all the defining properties of blazars in radio, optical, X-ray, and gamma-ray wavelengths.},
  language  = {en}
}
@article{ArchambaultBeilickeBenbowetal.2013,
  author    = {Archambault, S. and Beilicke, M. and Benbow, W. and Berger, K. and Bird, R. and Bouvier, A. and Buckley, J. H. and Bugaev, V. and Byrum, K. and Cerruti, M. and Chen, Xuhui and Ciupik, L. and Connolly, M. P. and Cui, W. and Duke, C. and Dumm, J. and Errando, M. and Falcone, A. and Federici, Simone and Feng, Q. and Finley, J. P. and Fortson, L. and Furniss, A. and Galante, N. and Gillanders, G. H. and Griffin, S. and Griffiths, S. T. and Grube, J. and Gyuk, G. and Hanna, D. and Holder, J. and Hughes, G. and Humensky, T. B. and Kaaret, P. and Kertzman, M. and Khassen, Y. and Kieda, D. and Krawczynski, H. and Lang, M. J. and Madhavan, A. S. and Maier, G. and Majumdar, P. and McArthur, S. and McCann, A. and Moriarty, P. and Mukherjee, R. and Nieto, D. and de Bhroithe, A. O'Faolain and Ong, R. A. and Otte, A. N. and Pandel, D. and Park, N. and Perkins, J. S. and Pohl, Martin and Popkow, A. and Prokoph, H. and Quinn, J. and Ragan, K. and Rajotte, J. and Reyes, L. C. and Reynolds, P. T. and Richards, G. T. and Roache, E. and Sembroski, G. H. and Sheidaei, F. and Smith, A. W. and Staszak, D. and Telezhinsky, Igor O. and Theiling, M. and Tucci, J. V. and Tyler, J. and Varlotta, A. and Vincent, S. and Wakely, S. P. and Weekes, T. C. and Weinstein, A. and Williams, D. A. and Zitzer, B. and McCollough, M. L.},
  title     = {Veritas observatons of the microquasar cygnus X-3},
  series = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  volume    = {779},
  journal   = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  number    = {2},
  publisher = {IOP Publ. Ltd.},
  address   = {Bristol},
  organization    = {VERITAS Collaboration, Smithsonian Astrophys Observ},
  issn      = {0004-637X},
  doi       = {10.1088/0004-637X/779/2/150},
  pages     = {10},
  year      = {2013},
  abstract  = {We report results from TeV gamma-ray observations of the microquasar Cygnus X-3. The observations were made with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) over a time period from 2007 June 11 to 2011 November 28. VERITAS is most sensitive to gamma rays at energies between 85 GeV and 30 TeV. The effective exposure time amounts to a total of about 44 hr, with the observations covering six distinct radio/X-ray states of the object. No significant TeV gamma-ray emission was detected in any of the states, nor with all observations combined. The lack of a positive signal, especially in the states where GeV gamma rays were detected, places constraints on TeV gamma-ray production in Cygnus X-3. We discuss the implications of the results.},
  language  = {en}
}
@article{AliuArchambaultArlenetal.2013,
  author    = {Aliu, E. and Archambault, S. and Arlen, T. and Aune, T. and Beilicke, M. and Benbow, W. and Bird, R. and Bouvier, A. and Buckley, J. H. and Bugaev, V. and Cesarini, A. and Ciupik, L. and Connolly, M. P. and Cui, W. and Dumm, J. and Errando, M. and Falcone, A. and Federici, Simone and Feng, Q. and Finley, J. P. and Fortin, P. and Fortson, L. and Furniss, A. and Galante, N. and Gerard, L. and Gillanders, G. H. and Griffin, S. and Grube, J. and Gyuk, G. and Hanna, D. and Holder, J. and Hughes, G. and Humensky, T. B. and Kaaret, P. and Kertzman, M. and Khassen, Y. and Kieda, D. and Krawczynski, H. and Krennrich, F. and Lang, M. J. and Madhavan, A. S. and Maier, G. and Majumdar, P. and McArthur, S. and McCann, A. and Moriarty, P. and Mukherjee, R. and Nieto, D. and De Bhroithe, A. O'Faolain and Ong, R. A. and Orr, M. and Otte, A. N. and Park, N. and Perkins, J. S. and Pohl, Martin and Popkow, A. and Prokoph, H. and Quinn, J. and Ragan, K. and Reyes, L. C. and Reynolds, P. T. and Richards, G. T. and Roache, E. and Saxon, D. B. and Sembroski, G. H. and Skole, C. and Smith, A. W. and Soares-Furtado, M. and Staszak, D. and Telezhinsky, Igor O. and Tesic, G. and Theiling, M. and Varlotta, A. and Vassiliev, V. V. and Vincent, S. and Wakely, S. P. and Weekes, T. C. and Weinstein, A. and Welsing, R. and Williams, D. A. and Zitzer, B. and B{\"o}ttcher, Markus and Fumagalli, M. and Jadhav, J.},
  title     = {Long term observations of B2 1215+30 with veritas},
  series = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  volume    = {779},
  journal   = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  number    = {2},
  publisher = {IOP Publ. Ltd.},
  address   = {Bristol},
  organization    = {VERITAS Collaboration},
  issn      = {0004-637X},
  doi       = {10.1088/0004-637X/779/2/92},
  pages     = {9},
  year      = {2013},
  abstract  = {We report on VERITAS observations of the BL Lac object B2 1215+30 between 2008 and 2012. During this period, the source was detected at very high energies (VHEs; E > 100 GeV) by VERITAS with a significance of 8.9s and showed clear variability on timescales larger than months. In 2011, the source was found to be in a relatively bright state and a power-law fit to the differential photon spectrum yields a spectral index of 3.6 +/- 0.4(stat) +/- 0.3(syst) with an integral flux above 200 GeV of (8.0 +/- 0.9(stat) +/- 3.2(syst)) x 10(-12) cm(-2) s(-1). No short term variability could be detected during the bright state in 2011. Multi-wavelength data were obtained contemporaneously with the VERITAS observations in 2011 and cover optical (Super-LOTIS, MDM, Swift/UVOT), X-ray (Swift/XRT), and gamma-ray (Fermi-LAT) frequencies. These were used to construct the spectral energy distribution (SED) of B2 1215+30. A one-zone leptonic model is used to model the blazar emission and the results are compared to those of MAGIC from early 2011 and other VERITAS-detected blazars. The SED can be reproduced well with model parameters typical for VHE-detected BL Lac objects.},
  language  = {en}
}
@article{AliuAuneBeheraetal.2014,
  author    = {Aliu, E. and Aune, T. and Behera, B. and Beilicke, M. and Benbow, W. and Berger, K. and Bird, R. and Bouvier, A. and Buckley, J. H. and Bugaev, V. and Cerruti, M. and Chen, Xuhui and Ciupik, L. and Connolly, M. P. and Cui, W. and Dumm, J. and Dwarkadas, Vikram V. and Errando, M. and Falcone, A. and Federici, Simone and Feng, Q. and Finley, J. P. and Fleischhack, H. and Fortin, P. and Fortson, L. and Furniss, A. and Galante, N. and Gillanders, G. H. and Gotthelf, E. V. and Griffin, S. and Griffiths, S. T. and Grube, J. and Gyuk, G. and Hanna, D. and Holder, J. and Hughes, G. and Humensky, T. B. and Johnson, C. A. and Kaaret, P. and Kargaltsev, O. and Kertzman, M. and Khassen, Y. and Kieda, D. and Krennrich, F. and Lang, M. J. and Madhavan, A. S. and Maier, G. and McArthur, S. and McCann, A. and Millis, J. and Moriarty, P. and Mukherjee, R. and Nieto, D. and Ong, R. A. and Otte, A. N. and Pandel, D. and Park, N. and Pohl, Martin and Popkow, A. and Prokoph, H. and Quinn, J. and Ragan, K. and Rajotte, J. and Reyes, L. C. and Reynolds, P. T. and Richards, G. T. and Roache, E. and Roberts, M. and Sembroski, G. H. and Shahinyan, K. and Smith, A. W. and Staszak, D. and Telezhinsky, Igor O. and Tucci, J. V. and Tyler, J. and Vincent, S. and Wakely, S. P. and Weinstein, A. and Welsing, R. and Wilhelm, Alina and Williams, D. A. and Zitzer, B.},
  title     = {Spatially resolving the very high energy emission from MRGO J2019+37 wih veritas},
  series = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  volume    = {788},
  journal   = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  number    = {1},
  publisher = {IOP Publ. Ltd.},
  address   = {Bristol},
  issn      = {0004-637X},
  doi       = {10.1088/0004-637X/788/1/78},
  pages     = {10},
  year      = {2014},
  abstract  = {We present very high energy (VHE) imaging of MGRO J2019+37 obtained with the VERITAS observatory. The bright extended (similar to 2 degrees) unidentified Milagro source is located toward the rich star formation region Cygnus-X. MGRO J2019+37 is resolved into two VERITAS sources. The faint, point-like source VER J2016+371 overlaps CTB 87, a filled-center remnant (SNR) with no evidence of a supernova remnant shell at the present time. Its spectrum is well fit in the 0.65-10 TeV energy range by a power-law model with photon index 2.3 +/- 0.4. VER J2019+378 is a bright extended (similar to 1 degrees) source that likely accounts for the bulk of the Milagro emission and is notably coincident with PSR J2021+3651 and the star formation region Sh 2-104. Its spectrum in the range 1-30 TeV is well fit with a power-law model of photon index 1.75 +/- 0.3, among the hardest values measured in the VHE band, comparable to that observed near Vela-X. We explore the unusual spectrum and morphology in the radio and X-ray bands to constrain possible emission mechanisms for this source.},
  language  = {en}
}
@article{ArlenAuneBeilickeetal.2012,
  author    = {Arlen, T. and Aune, T. and Beilicke, M. and Benbow, W. and Bouvier, A. and Buckley, J. H. and Bugaev, V. and Byrum, K. and Cannon, A. and Cesarini, A. and Ciupik, L. and Collins-Hughes, E. and Connolly, M. P. and Cui, W. and Dickherber, R. and Dumm, J. and Falcone, A. and Federici, S. and Feng, Q. and Finley, J. P. and Finnegan, G. and Fortson, L. and Furniss, A. and Galante, N. and Gall, D. and Godambe, S. and Griffin, S. and Grube, J. and Gyuk, G. and Holder, J. and Huan, H. and Hughes, G. and Humensky, T. B. and Imran, A. and Kaaret, P. and Karlsson, N. and Kertzman, M. and Khassen, Y. and Kieda, D. and Krawczynski, H. and Krennrich, F. and Lee, K. and Madhavan, A. S. and Maier, G. and Majumdar, P. and McArthur, S. and McCann, A. and Moriarty, P. and Mukherjee, R. and Nelson, T. and de Bhroithe, A. O'Faolain and Ong, R. A. and Orr, M. and Otte, A. N. and Park, N. and Perkins, J. S. and Pohl, Martin and Prokoph, H. and Quinn, J. and Ragan, K. and Reyes, L. C. and Reynolds, P. T. and Roache, E. and Ruppel, J. and Saxon, D. B. and Schroedter, M. and Sembroski, G. H. and Skole, C. and Smith, A. W. and Telezhinsky, Igor O. and Tesic, G. and Theiling, M. and Thibadeau, S. and Tsurusaki, K. and Varlotta, A. and Vivier, M. and Wakely, S. P. and Ward, J. E. and Weinstein, A. and Welsing, R. and Williams, D. A. and Zitzer, B. and Pfrommer, C. and Pinzke, A.},
  title     = {Constraints on cosmic rays, magnetic fields, and dark matter fromgamma-ray observations of the coma cluster of galaxies with veritas and fermi},
  series = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  volume    = {757},
  journal   = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  number    = {2},
  publisher = {IOP Publ. Ltd.},
  address   = {Bristol},
  issn      = {0004-637X},
  doi       = {10.1088/0004-637X/757/2/123},
  pages     = {14},
  year      = {2012},
  abstract  = {Observations of radio halos and relics in galaxy clusters indicate efficient electron acceleration. Protons should likewise be accelerated and, on account of weak energy losses, can accumulate, suggesting that clusters may also be sources of very high energy (VHE; E > 100 GeV) gamma-ray emission. We report here on VHE gamma-ray observations of the Coma galaxy cluster with the VERITAS array of imaging Cerenkov telescopes, with complementing Fermi Large Area Telescope observations at GeV energies. No significant gamma-ray emission from the Coma Cluster was detected. Integral flux upper limits at the 99\% confidence level were measured to be on the order of (2-5) x 10(-8) photonsm(-2) s(-1) (VERITAS, >220 GeV) and similar to 2 x 10(-6) photonsm(-2) s(-1) (Fermi, 1-3GeV), respectively. We use the gamma-ray upper limits to constrain cosmic rays (CRs) and magnetic fields in Coma. Using an analytical approach, the CR-to-thermal pressure ratio is constrained to be < 16\% from VERITAS data and <1.7\% from Fermi data (averaged within the virial radius). These upper limits are starting to constrain the CR physics in self-consistent cosmological cluster simulations and cap the maximum CR acceleration efficiency at structure formation shocks to be <50\%. Alternatively, this may argue for non-negligible CR transport processes such as CR streaming and diffusion into the outer cluster regions. Assuming that the radio-emitting electrons of the Coma halo result from hadronic CR interactions, the observations imply a lower limit on the central magnetic field in Coma of similar to(2-5.5) mu G, depending on the radial magnetic field profile and on the gamma-ray spectral index. Since these values are below those inferred by Faraday rotation measurements in Coma (for most of the parameter space), this renders the hadronic model a very plausible explanation of the Coma radio halo. Finally, since galaxy clusters are dark matter (DM) dominated, the VERITAS upper limits have been used to place constraints on the thermally averaged product of the total self-annihilation cross section and the relative velocity of the DM particles, <sigma nu >.},
  language  = {en}
}
@article{AliuArchambaultAuneetal.2014,
  author    = {Aliu, E. and Archambault, S. and Aune, T. and Behera, B. and Beilicke, M. and Benbow, W. and Berger, K. and Bird, R. and Buckley, J. H. and Bugaev, V. and Cardenzana, J. V. and Cerruti, M. and Chen, Xuhui and Ciupik, L. and Collins-Hughes, E. and Connolly, M. P. and Cui, W. and Dumm, J. and Dwarkadas, Vikram V. and Errando, M. and Falcone, A. and Federici, Simone and Feng, Q. and Finley, J. P. and Fleischhack, H. and Fortin, P. and Fortson, L. and Furniss, A. and Galante, N. and Gall, D. and Gillanders, G. H. and Griffin, S. and Griffiths, S. T. and Grube, J. and Gyuk, G. and Hanna, D. and Holder, J. and Hughes, G. and Humensky, T. B. and Kaaret, P. and Kertzman, M. and Khassen, Y. and Kieda, D. and Krennrich, F. and Kumar, S. and Lang, M. J. and Madhavan, A. S. and Maier, G. and McCann, A. J. and Meagher, K. and Millis, J. and Moriarty, P. and Mukherjee, R. and Nieto, D. and Ong, R. A. and Otte, A. N. and Pandel, D. and Park, N. and Pohl, Martin and Popkow, A. and Prokoph, H. and Quinn, J. and Ragan, K. and Rajotte, J. and Ratliff, G. and Reyes, L. C. and Reynolds, P. T. and Richards, G. T. and Roache, E. and Rousselle, J. and Sembroski, G. H. and Shahinyan, K. and Sheidaei, F. and Smith, A. W. and Staszak, D. and Telezhinsky, Igor O. and Tsurusaki, K. and Tucci, J. V. and Tyler, J. and Varlotta, A. and Vassiliev, V. V. and Vincent, S. and Wakely, S. P. and Ward, J. E. and Weinstein, A. and Welsing, R. and Wilhelm, Alina},
  title     = {Investigating the TeV morpholoy of MGRO J1908+06 with veritas},
  series = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  volume    = {787},
  journal   = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  number    = {2},
  publisher = {IOP Publ. Ltd.},
  address   = {Bristol},
  issn      = {0004-637X},
  doi       = {10.1088/0004-637X/787/2/166},
  pages     = {7},
  year      = {2014},
  abstract  = {We report on deep observations of the extended TeV gamma-ray source MGRO J1908+06 made with the VERITAS very high energy gamma-ray observatory. Previously, the TeV emission has been attributed to the pulsar wind nebula (PWN) of the Fermi-LAT pulsar PSR J1907+0602. We detect MGRO J1908+06 at a significance level of 14 standard deviations (14 sigma) and measure a photon index of 2.20 +/- 0.10(stat) +/- 0.20(sys). The TeV emission is extended, covering the region near PSR J1907+0602 and also extending toward SNR G40.5-0.5. When fitted with a two-dimensional Gaussian, the intrinsic extension has a standard deviation of sigma(src) = 0 degrees.44 +/- 0 degrees.02. In contrast to other TeV PWNe of similar age in which the TeV spectrum softens with distance from the pulsar, the TeV spectrum measured near the pulsar location is consistent with that measured at a position near the rim of G40.5-0.5, 0 degrees.33 away.},
  language  = {en}
}
@article{AliuArchambaultArlenetal.2012,
  author    = {Aliu, E. and Archambault, S. and Arlen, T. and Aune, T. and Beilicke, M. and Benbow, W. and Boettcher, Markus and Bouvier, A. and Buckley, J. H. and Bugaev, V. and Cesarini, A. and Ciupik, L. and Collins-Hughes, E. and Connolly, M. P. and Cui, W. and Dickherber, R. and Duke, C. and Dumm, J. and Errando, M. and Falcone, A. and Federici, Simone and Feng, Q. and Finley, J. P. and Finnegan, G. and Fortson, L. and Furniss, A. and Galante, N. and Gall, D. and Godambe, S. and Griffin, S. and Grube, J. and Gyuk, G. and Hanna, D. and Holder, J. and Huan, H. and Kaaret, P. and Karlsson, N. and Khassen, Y. and Kieda, D. and Krawczynski, H. and Krennrich, F. and Lee, K. and Madhavan, A. S. and Maier, G. and Majumdar, P. and McArthur, S. and McCann, A. and Moriarty, P. and Mukherjee, R. and Nelson, T. and de Bhroithe, A. O'Faolain and Ong, R. A. and Orr, M. and Otte, A. N. and Park, N. and Perkins, J. S. and Pichel, A. and Pohl, Martin and Prokoph, H. and Quinn, J. and Ragan, K. and Reyes, L. C. and Reynolds, P. T. and Roache, E. and Saxon, D. B. and Sembroski, G. H. and Staszak, D. and Telezhinsky, Igor O. and Tesic, G. and Theiling, M. and Thibadeau, S. and Tsurusaki, K. and Varlotta, A. and Vassiliev, V. V. and Vincent, S. and Vivier, M. and Wakely, S. P. and Weekes, T. C. and Weinstein, A. and Welsing, R. and Williams, D. A. and Zitzer, B. and Fortin, P. and Horan, D. and Fumagalli, M. and Kaplan, K. and Prochaska, J. X.},
  title     = {Veritas observations of six bright, hard-spectrum fermi-lat blazars},
  series = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  volume    = {759},
  journal   = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  number    = {2},
  publisher = {IOP Publ. Ltd.},
  address   = {Bristol},
  organization    = {VERITAS Collaboration},
  issn      = {0004-637X},
  doi       = {10.1088/0004-637X/759/2/102},
  pages     = {13},
  year      = {2012},
  abstract  = {We report on VERITAS very high energy (VHE; E >= 100 GeV) observations of six blazars selected from the Fermi Large Area Telescope First Source Catalog (1FGL). The gamma-ray emission from 1FGL sources was extrapolated up to the VHE band, taking gamma-ray absorption by the extragalactic background light into account. This allowed the selection of six bright, hard-spectrum blazars that were good candidate TeV emitters. Spectroscopic redshift measurements were attempted with the Keck Telescope for the targets without Sloan Digital Sky Survey spectroscopic data. No VHE emission is detected during the observations of the six sources described here. Corresponding TeV upper limits are presented, along with contemporaneous Fermi observations and non-concurrent Swift UVOT and X-Ray Telescope data. The blazar broadband spectral energy distributions (SEDs) are assembled and modeled with a single-zone synchrotron self-Compton model. The SED built for each of the six blazars shows a synchrotron peak bordering between the intermediate-and high-spectrum-peak classifications, with four of the six resulting in particle-dominated emission regions.},
  language  = {en}
}
@article{ArlenAuneBeilickeetal.2013,
  author    = {Arlen, T. and Aune, T. and Beilicke, M. and Benbow, W. and Bouvier, A. and Buckley, J. H. and Bugaev, V. and Cesarini, A. and Ciupik, L. and Connolly, M. P. and Cui, W. and Dickherber, R. and Dumm, J. and Errando, M. and Falcone, A. and Federici, S. and Feng, Q. and Finley, J. P. and Finnegan, G. and Fortson, L. and Furniss, A. and Galante, N. and Gall, D. and Griffin, S. and Grube, J. and Gyuk, G. and Hanna, D. and Holder, J. and Humensky, T. B. and Kaaret, P. and Karlsson, N. and Kertzman, M. and Khassen, Y. and Kieda, D. and Krawczynski, H. and Krennrich, F. and Maier, G. and Moriarty, P. and Mukherjee, R. and Nelson, T. and de Bhroithe, A. O'Faolain and Ong, R. A. and Orr, M. and Park, N. and Perkins, J. S. and Pichel, A. and Pohl, Martin and Prokoph, H. and Quinn, J. and Ragan, K. and Reyes, L. C. and Reynolds, P. T. and Roache, E. and Saxon, D. B. and Schroedter, M. and Sembroski, G. H. and Staszak, D. and Telezhinsky, Igor O. and Tesic, G. and Theiling, M. and Tsurusaki, K. and Varlotta, A. and Vincent, S. and Wakely, S. P. and Weekes, T. C. and Weinstein, A. and Welsing, R. and Williams, D. A. and Zitzer, B. and Jorstad, S. G. and MacDonald, N. R. and Marscher, A. P. and Smith, P. S. and Walker, R. C. and Hovatta, T. and Richards, J. and Max-Moerbeck, W. and Readhead, A. and Lister, M. L. and Kovalev, Y. Y. and Pushkarev, A. B. and Gurwell, M. A. and Lahteenmaki, A. and Nieppola, E. and Tornikoski, M. and Jarvela, E.},
  title     = {Rapid TeV Gamma-Ray flaring of bl lacertae},
  series = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  volume    = {762},
  journal   = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  number    = {2},
  publisher = {IOP Publ. Ltd.},
  address   = {Bristol},
  organization    = {VERITAS Collaboration},
  issn      = {0004-637X},
  doi       = {10.1088/0004-637X/762/2/92},
  pages     = {13},
  year      = {2013},
  abstract  = {We report on the detection of a very rapid TeV gamma-ray flare from BL Lacertae on 2011 June 28 with the Very Energetic Radiation Imaging Telescope Array System (VERITAS). The flaring activity was observed during a 34.6 minute exposure, when the integral flux above 200 GeV reached (3.4 +/- 0.6) x 10(-6) photons m(-2) s(-1), roughly 125\% of the Crab Nebula flux measured by VERITAS. The light curve indicates that the observations missed the rising phase of the flare but covered a significant portion of the decaying phase. The exponential decay time was determined to be 13 +/- 4 minutes, making it one of the most rapid gamma-ray flares seen from a TeV blazar. The gamma-ray spectrum of BL Lacertae during the flare was soft, with a photon index of 3.6 +/- 0.4, which is in agreement with the measurement made previously by MAGIC in a lower flaring state. Contemporaneous radio observations of the source with the Very Long Baseline Array revealed the emergence of a new, superluminal component from the core around the time of the TeV gamma-ray flare, accompanied by changes in the optical polarization angle. Changes in flux also appear to have occurred at optical, UV, and GeV gamma-ray wavelengths at the time of the flare, although they are difficult to quantify precisely due to sparse coverage. A strong flare was seen at radio wavelengths roughly four months later, which might be related to the gamma-ray flaring activities. We discuss the implications of these multiwavelength results.},
  language  = {en}
}
@article{AliuArchambaultArlenetal.2013,
  author    = {Aliu, E. and Archambault, S. and Arlen, T. and Aune, T. and Beilicke, M. and Benbow, W. and Bird, R. and Boettcher, Markus and Bouvier, A. and Bugaev, V. and Byrum, K. and Cesarini, A. and Ciupik, L. and Collins-Hughes, E. and Connolly, M. P. and Cui, W. and Dickherber, R. and Duke, C. and Dumm, J. and Errando, M. and Falcone, A. and Federici, Simone and Feng, Q. and Finley, J. P. and Finnegan, G. and Fortson, L. and Furniss, A. and Galante, N. and Gall, D. and Gillanders, G. H. and Griffin, S. and Grube, J. and Gyuk, G. and Hanna, D. and Holder, J. and Hughes, G. and Humensky, T. B. and Kaaret, P. and Kertzman, M. and Khassen, Y. and Kieda, D. and Krawczynski, H. and Krennrich, F. and Lang, M. J. and Madhavan, A. S. and Maier, G. and Majumdar, P. and McArthur, S. and McCann, A. and Moriarty, P. and Mukherjee, R. and Nelson, T. and de Bhroithe, A. O'Faolain and Ong, R. A. and Orr, M. and Otte, A. N. and Park, N. and Perkins, J. S. and Pichel, A. and Pohl, Martin and Popkow, A. and Prokoph, H. and Quinn, J. and Ragan, K. and Reyes, L. C. and Reynolds, P. T. and Roache, E. and Saxon, D. B. and Schroedter, M. and Sembroski, G. H. and Skole, C. and Smith, A. W. and Staszak, D. and Telezhinsky, Igor O. and Theiling, M. and Tyler, J. and Varlotta, A. and Vassiliev, V. V. and Wakely, S. P. and Weekes, T. C. and Weinstein, A. and Welsing, R. and Williams, D. A. and Zitzer, B.},
  title     = {Multiwavelenght observations and modeling of 1ES 1959+650 in a low flux state},
  series = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  volume    = {775},
  journal   = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  number    = {1},
  publisher = {IOP Publ. Ltd.},
  address   = {Bristol},
  issn      = {0004-637X},
  doi       = {10.1088/0004-637X/775/1/3},
  pages     = {8},
  year      = {2013},
  abstract  = {We report on the VERITAS observations of the high-frequency peaked BL Lac object 1ES 1959+650 in the period 2007-2011. This source is detected at TeV energies by VERITAS at 16.4 standard deviation (sigma) significance in 7.6 hr of observation in a low flux state. A multiwavelength spectral energy distribution (SED) is constructed from contemporaneous data from VERITAS, Fermi-LAT, RXTE PCA, and Swift UVOT. Swift XRT data is not included in the SED due to a lack of simultaneous observations with VERITAS. In contrast to the orphan gamma-ray flare exhibited by this source in 2002, the X-ray flux of the source is found to vary by an order of magnitude, while other energy regimes exhibit less variable emission. A quasi-equilibrium synchrotron self-Compton model with an additional external radiation field is used to describe three SEDs corresponding to the lowest, highest, and average X-ray states. The variation in the X-ray spectrum is modeled by changing the electron injection spectral index, with minor adjustments of the kinetic luminosity in electrons. This scenario produces small-scale flux variability of the order of less than or similar to 2 in the high energy (E > 1MeV) and very high energy (E > 100 GeV) gamma-ray regimes, which is corroborated by the Fermi-LAT, VERITAS, and Whipple 10 m telescope light curves.},
  language  = {en}
}
@article{AliuArchambaultBeheraetal.2013,
  author    = {Aliu, E. and Archambault, S. and Behera, B. and Berger, K. and Beilicke, M. and Benbow, W. and Bird, R. and Bouvier, A. and Bugaev, V. and Cerruti, M. and Chen, Xuhui and Ciupik, L. and Connolly, M. P. and Cui, W. and Dumm, J. and Falcone, A. and Federici, Simone and Feng, Q. and Finley, J. P. and Fortin, P. and Fortson, L. and Furniss, A. and Galante, N. and Gillanders, G. H. and Griffin, S. and Griffiths, S. T. and Grube, J. and Gyuk, G. and Hanna, D. and Holder, J. and Hughes, G. and Humensky, T. B. and Kaaret, P. and Kertzman, M. and Khassen, Y. and Kieda, D. and Krennrich, F. and Lang, M. J. and Maier, G. and Majumdar, P. and McArthur, S. and McCann, A. and Moriarty, P. and Mukherjee, R. and de Bhroithe, A. O'Faolain and Ong, R. A. and Otte, A. N. and Park, N. and Perkins, J. S. and Pohl, Martin and Popkow, A. and Prokoph, H. and Quinn, J. and Ragan, K. and Rajotte, J. and Ratliff, G. and Reynolds, P. T. and Richards, G. T. and Roache, E. and Sembroski, G. H. and Sheidaei, F. and Skole, C. and Smith, A. W. and Staszak, D. and Telezhinsky, Igor O. and Tyler, J. and Varlotta, A. and Vincent, S. and Wakely, S. P. and Weekes, T. C. and Weinstein, A. and Welsing, R. and Zajczyk, A. and Zitzer, B.},
  title     = {Multiwavelemght oservatons of the TeV binary LS I+61 degrees 303 with veritas, fermi-lat, and swift/XRT during a TeV outburst},
  series = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  volume    = {779},
  journal   = {The astrophysical journal : an international review of spectroscopy and astronomical physics},
  number    = {1},
  publisher = {IOP Publ. Ltd.},
  address   = {Bristol},
  issn      = {0004-637X},
  doi       = {10.1088/0004-637X/779/1/88},
  pages     = {7},
  year      = {2013},
  abstract  = {We present the results of a multiwavelength observational campaign on the TeV binary system LS I +61 degrees 303 with the VERITAS telescope array (>200 GeV), Fermi-LAT (0.3-300 GeV), and Swift/XRT (2-10 keV). The data were taken from 2011 December through 2012 January and show a strong detection in all three wavebands. During this period VERITAS obtained 24.9 hr of quality selected livetime data in which LS I +61 degrees 303 was detected at a statistical significance of 11.9 sigma. These TeV observations show evidence for nightly variability in the TeV regime at a post-trial significance of 3.6 sigma. The combination of the simultaneously obtained TeV and X-ray fluxes do not demonstrate any evidence for a correlation between emission in the two bands. For the first time since the launch of the Fermi satellite in 2008, this TeV detection allows the construction of a detailed MeV-TeV spectral energy distribution from LS I +61 degrees 303. This spectrum shows a distinct cutoff in emission near 4 GeV, with emission seen by the VERITAS observations following a simple power-law above 200 GeV. This feature in the spectrum of LS I +61 degrees 303, obtained from overlapping observations with Fermi-LAT and VERITAS, may indicate that there are two distinct populations of accelerated particles producing the GeV and TeV emission.},
  language  = {en}
}
@article{AbdallaAbramowskiAharonianetal.2016,
  author    = {Abdalla, Hassan E. and Abramowski, Attila and Aharonian, Felix A. and Benkhali, Fai{\c{c}}al Ait and Akhperjanian, A. G. and Ang{\"u}ner, Ekrem Oǧuzhan and Arrieta, M. and Aubert, Pierre and Backes, Michael and Balzer, Arnim and Barnard, Michelle and Becherini, Yvonne and Tjus, Julia Becker and Berge, David and Bernhard, Sabrina and Bernl{\"o}hr, K. and Birsin, E. and Blackwell, R. and Bottcher, Markus and Boisson, Catherine and Bolmont, J. and Bordas, Pol and Bregeon, Johan and Brun, Francois and Brun, Pierre and Bryan, Mark and Bulik, Tomasz and Capasso, M. and Carr, John and Casanova, Sabrina and Chakraborty, N. and Chalme-Calvet, R. and Chaves, Ryan C. G. and Chen, Andrew and Chevalier, J. and Chretien, M. and Colafrancesco, Sergio and Cologna, Gabriele and Condon, B. and Conrad, Jan and Couturier, C. and Cui, Y. and Davids, I. D. and Degrange, B. and Deil, Christoph and deWilt, P. and Djannati-Atai, Arache and Domainko, Wilfried and Donath, Axel and Dubus, Guillaume and Dutson, Kate and Dyks, J. and Dyrda, M. and Edwards, T. and Egberts, Kathrin and Eger, P. and Ernenwein, J. -P. and Eschbach, S. and Farnier, C. and Fegan, Stuart and Fernandes, M. V. and Fiasson, A. and Fontaine, G. and Foerster, A. and Funk, S. and F{\"u}ßling, Matthias and Gabici, Stefano and Gajdus, M. and Gallant, Y. A. and Garrigoux, T. and Giavitto, Gianluca and Giebels, B. and Glicenstein, J. F. and Gottschall, Daniel and Goyal, A. and Grondin, M. -H. and Grudzinska, M. and Hadasch, Daniela and Hahn, J. and Hawkes, J. and Heinzelmann, G. and Henri, Gilles and Hermann, G. and Hervet, Olivier and Hillert, A. and Hinton, James Anthony and Hofmann, Werner and Hoischen, Clemens and Holler, M. and Horns, D. and Ivascenko, Alex and Jacholkowska, A. and Jamrozy, Marek and Janiak, M. and Jankowsky, D. and Jankowsky, Felix and Jingo, M. and Jogler, Tobias and Jouvin, Lea and Jung-Richardt, Ira and Kastendieck, M. A. and Katarzynski, Krzysztof and Katz, Uli and Kerszberg, D. and Khelifi, B. and Kieffer, M. and King, J. and Klepser, S. and Klochkov, Dmitry and Kluzniak, W. and Kolitzus, D. and Komin, Nu. and Kosack, K. and Krakau, S. and Kraus, Michael and Krayzel, F. and Kruger, P. P. and Laffon, H. and Lamanna, G. and Lau, Jeanie and Lees, J. -P. and Lefaucheur, J. and Lefranc, V. and Lemiere, A. and Lemoine-Goumard, M. and Lenain, J. -P. and Leser, Eva and Lohse, Thomas and Lorentz, M. and Lui, R. and Lypova, Iryna and Marandon, Vincent and Marcowith, Alexandre and Mariaud, C. and Marx, R. and Maurin, G. and Maxted, N. and Mayer, Michael and Meintjes, Petrus Johannes and Menzler, U. and Meyer, Manuel and Mitchell, A. M. W. and Moderski, R. and Mohamed, M. and Mora, K. and Moulin, Emmanuel and Murach, T. and de Naurois, Mathieu and Niederwanger, F. and Niemiec, J. and Oakes, L. and Odaka, Hirokazu and Ohm, Stefan and Oettl, S. and Ostrowski, M. and Oya, I. and Padovani, Marco and Panter, M. and Parsons, R. D. and Arribas, M. Paz and Pekeur, N. W. and Pelletier, G. and Petrucci, P. -O. and Peyaud, B. and Pita, S. and Poon, Helen and Prokhorov, Dmitry and Prokoph, Heike and Puehlhofer, Gerd and Punch, Michael and Quirrenbach, Andreas and Raab, S. and Reimer, Anita and Reimer, Olaf and Renaud, M. and de los Reyes, R. and Rieger, Frank and Romoli, Carlo and Rosier-Lees, S. and Rowell, G. and Rudak, B. and Rulten, C. B. and Sahakian, V. and Salek, David and Sanchez, David A. and Santangelo, Andrea and Sasaki, Manami and Schlickeiser, Reinhard and Schussler, F. and Schulz, Andreas and Schwanke, U. and Schwemmer, S. and Seyffert, A. S. and Shafi, N. and Simoni, R. and Sol, H. and Spanier, Felix and Spengler, G. and Spiess, F. and Stawarz, Lukasz and Steenkamp, R. and Stegmann, Christian and Stinzing, F. and Stycz, K. and Sushch, Iurii and Tavernet, J. -P. and Tavernier, T. and Taylor, A. M. and Terrier, R. and Tluczykont, Martin and Trichard, C. and Tuffs, R. and van der Walt, Johan and van Eldik, Christopher and van Soelen, Brian and Vasileiadis, Georges and Veh, J. and Venter, C. and Viana, A. and Vincent, P. and Vink, Jacco and Voisin, F. and Voelk, Heinrich J. and Vuillaume, Thomas and Wadiasingh, Z. and Wagner, Stefan J. and Wagner, P. and Wagner, R. M. and White, R. and Wierzcholska, Alicja and Willmann, P. and Woernlein, A. and Wouters, Denis and Yang, R. and Zabalza, Victor and Zaborov, D. and Zacharias, M. and Zdziarski, A. A. and Zech, Andreas and Zefi, F. and Ziegler, A. and Zywucka, Natalia},
  title     = {Search for Dark Matter Annihilations towards the Inner Galactic Halo from 10 Years of Observations with HESS},
  series = {Physical review letters},
  volume    = {117},
  journal   = {Physical review letters},
  publisher = {American Physical Society},
  address   = {College Park},
  organization    = {HESS Collaboration},
  issn      = {0031-9007},
  doi       = {10.1103/PhysRevLett.117.111301},
  pages     = {6},
  year      = {2016},
  abstract  = {The inner region of the Milky Way halo harbors a large amount of dark matter (DM). Given its proximity, it is one of the most promising targets to look for DM. We report on a search for the annihilations of DM particles using gamma-ray observations towards the inner 300 pc of the Milky Way, with the H.E.S.S. array of ground-based Cherenkov telescopes. The analysis is based on a 2D maximum likelihood method using Galactic Center (GC) data accumulated by H.E.S.S. over the last 10 years (2004-2014), and does not show any significant gamma-ray signal above background. Assuming Einasto and Navarro-Frenk-White DM density profiles at the GC, we derive upper limits on the annihilation cross section <sigma nu >. These constraints are the strongest obtained so far in the TeV DM mass range and improve upon previous limits by a factor 5. For the Einasto profile, the constraints reach <sigma nu > values of 6 x 10(-26) cm(3) s(-1) in the W+W- channel for a DM particle mass of 1.5 TeV, and 2 x 10(-26) cm(3) s(-1) in the tau(+)tau(-) channel for a 1 TeV mass. For the first time, ground-based gamma-ray observations have reached sufficient sensitivity to probe <sigma nu > values expected from the thermal relic density for TeV DM particles.},
  language  = {en}
}