TY  - JOUR
A1  - Aleksic, J.
A1  - Ansoldi, S.
A1  - Antonelli, L. A.
A1  - Antoranz, P.
A1  - Babic, A.
A1  - Bangale, P.
A1  - de Almeida, U. Barres
A1  - Barrio, J. A.
A1  - Gonzalez, J. Becerra
A1  - Bednarek, W.
A1  - Berger, K.
A1  - Bernardini, E.
A1  - Bilandli, A.
A1  - Bianch, O.
A1  - Bock, R. K.
A1  - Bonnefoy, S.
A1  - Bonnoli, G.
A1  - Borracci, F.
A1  - Bretz, T.
A1  - Carmona, E.
A1  - Carosi, A.
A1  - Fidalgo, D. Carreto
A1  - Colin, P.
A1  - Colombo, E.
A1  - Contreras, J. L.
A1  - Cortina, J.
A1  - Covino, S.
A1  - Da Vela, P.
A1  - Dazzi, F.
A1  - De Angelis, A.
A1  - De Caneva, G.
A1  - De Lotto, B.
A1  - Delgado Mendez, C.
A1  - Doert, M.
A1  - Dominguez, A.
A1  - Prester, Dijana Dominis
A1  - Dorner, D.
A1  - Doro, M.
A1  - Einecke, S.
A1  - Eisenacher, D.
A1  - Elsaesser, D.
A1  - Farina, E.
A1  - Ferenc, D.
A1  - Fonseca, M. V.
A1  - Font, L.
A1  - Frantzen, K.
A1  - Fruck, C.
A1  - Garcia Lopez, R. J.
A1  - Garczarczyki, M.
A1  - Garrido Terrats, D.
A1  - Gaug, M.
A1  - Giavitto, G.
A1  - Godinovic, N.
A1  - Gonzalez Munoz, A.
A1  - Gozzini, S. R.
A1  - Hadamek, A.
A1  - Hadasch, D.
A1  - Herrero, A.
A1  - Hildebrand, D.
A1  - Hose, J.
A1  - Hrupec, D.
A1  - Idec, W.
A1  - Kadenius, V.
A1  - Kellermann, H.
A1  - Knoetig, M. L.
A1  - Krause, J.
A1  - Kushida, J.
A1  - La Barbera, A.
A1  - Lelas, D.
A1  - Lewandowska, N.
A1  - Lindfors, E.
A1  - Longo, F.
A1  - Lombardi, S.
A1  - Lopez, M.
A1  - Lopez-Coto, R.
A1  - Lopez-Oramas, A.
A1  - Lorenz, E.
A1  - Lozano, I.
A1  - Makariev, M.
A1  - Mallot, K.
A1  - Maneva, G.
A1  - Mankuzhiyil, N.
A1  - Mannheim, K.
A1  - Maraschi, L.
A1  - Marcote, B.
A1  - Mariotti, M.
A1  - Martinez, M.
A1  - Mazin, D.
A1  - Menzel, U.
A1  - Meucci, M.
A1  - Miranda, J. M.
A1  - Mirzoyan, R.
A1  - Moralejo, A.
A1  - Munar-Adrover, P.
A1  - Nakajima, D.
A1  - Niedzwiecki, A.
A1  - Nilsson, K.
A1  - Nowak, N.
A1  - Orito, R.
A1  - Overkemping, A.
A1  - Paiano, S.
A1  - Palatiello, M.
A1  - Paneque, D.
A1  - Paoletti, R.
A1  - Paredes, J. M.
A1  - Paredes-Fortuny, X.
A1  - Partini, S.
A1  - Persic, M.
A1  - Prada, F.
A1  - Moroni, P. G. Prada
A1  - Prandini, E.
A1  - Preziuso, S.
A1  - Puljak, I.
A1  - Reinthal, R.
A1  - Rhode, W.
A1  - Ribo, M.
A1  - Rico, J.
A1  - Garcia, J. Rodriguez
A1  - Ruegamer, S.
A1  - Saggion, A.
A1  - Saito, K.
A1  - Salvati, M.
A1  - Satalecka, K.
A1  - Scalzotto, V.
A1  - Scapin, V.
A1  - Schuliz, C.
A1  - Schweizer, T.
A1  - Shore, S. N.
A1  - Sillanpaa, A.
A1  - Sitarek, J.
A1  - Snidaric, I.
A1  - Sobczynska, D.
A1  - Spanier, F.
A1  - Stamatescu, V.
A1  - Stamerra, A.
A1  - Steinbring, T.
A1  - Storz, J.
A1  - Sun, S.
A1  - Suric, T.
A1  - Takalo, L.
A1  - Tavecchio, F.
A1  - Temnikov, P.
A1  - Terzic, T.
A1  - Tescaro, D.
A1  - Teshima, M.
A1  - Thaele, J.
A1  - Tibolla, O.
A1  - Torres, D. F.
A1  - Toyama, T.
A1  - Treves, A.
A1  - Uellenbeck, M.
A1  - Vogler, P.
A1  - Wagner, R. M.
A1  - Zandanel, F.
A1  - Zanin, R.
A1  - Archambault, S.
A1  - Behera, B.
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Bird, R.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Cerruti, M.
A1  - Chen, X.
A1  - Ciupik, L.
A1  - Collins-Hughes, E.
A1  - Cui, W.
A1  - Dumm, J.
A1  - Eisch, J. D.
A1  - Falcone, A.
A1  - Federici, S.
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Fleischhack, H.
A1  - Fortin, P.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Griffin, S.
A1  - Griffiths, S. T.
A1  - Grube, J.
A1  - Gyuk, G.
A1  - Hanna, D.
A1  - Holder, J.
A1  - Hughes, G.
A1  - Humensky, T. B.
A1  - Johnson, C. A.
A1  - Kaaret, P.
A1  - Kertzman, M.
A1  - Khassen, Y.
A1  - Kieda, D.
A1  - Krawczynski, H.
A1  - Krennrich, F.
A1  - Kumar, S.
A1  - Lang, M. J.
A1  - Maier, G.
A1  - McArthur, S.
A1  - Meagher, K.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Ong, R. A.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Pichel, A.
A1  - Pohl, M.
A1  - Popkow, A.
A1  - Prokoph, H.
A1  - Quinn, M. J.
A1  - Ragan, K.
A1  - Rajotte, J.
A1  - Reynolds, P. T.
A1  - Richards, G. T.
A1  - Roache, E.
A1  - Rovero, A. C.
A1  - Sembroski, G. H.
A1  - Shahinyan, K.
A1  - Staszak, D.
A1  - Telezhinsky, Igor O.
A1  - Theiling, M.
A1  - Tucci, J. V.
A1  - Tyler, J.
A1  - Varlotta, A.
A1  - Wakely, S. P.
A1  - Weekes, T. C.
A1  - Weinstein, A.
A1  - Welsing, R.
A1  - Wilhelm, Alina
A1  - Williams, D. A.
A1  - Zitzer, B.
A1  - Villata, M.
A1  - Raiteri, C.
A1  - Aller, H. D.
A1  - Aller, M. F.
A1  - Chen, W. P.
A1  - Jordan, B.
A1  - Koptelova, E.
A1  - Kurtanidze, O. M.
A1  - Lahteenmaki, A.
A1  - McBreen, B.
A1  - Larionov, V. M.
A1  - Lin, C. S.
A1  - Nikolashvili, M. G.
A1  - Angelakis, E.
A1  - Capalbi, M.
A1  - Carraminana, A.
A1  - Carrasco, L.
A1  - Cassaro, P.
A1  - Cesarini, A.
A1  - Fuhrmann, L.
A1  - Giroletti, M.
A1  - Hovatta, T.
A1  - Krichbaum, T. P.
A1  - Krimm, H. A.
A1  - Max-Moerbeck, W.
A1  - Moody, J. W.
A1  - Maccaferri, G.
A1  - Mori, Y.
A1  - Nestoras, I.
A1  - Orlati, A.
A1  - Pace, C.
A1  - Pearson, R.
A1  - Perri, M.
A1  - Readhead, A. C. S.
A1  - Richards, J. L.
A1  - Sadun, A. C.
A1  - Sakamoto, T.
A1  - Tammi, J.
A1  - Tornikoski, M.
A1  - Yatsu, Y.
A1  - Zook, A.
T1  - The 2009 multiwavelength campaign on Mrk 421: Variability and correlation studies
JF  - Astronomy and astrophysics : an international weekly journal
N2  - Aims. We perform an extensive characterization of the broadband emission of Mrk 421, as well as its temporal evolution, during the non-flaring (low) state. The high brightness and nearby location (z = 0.031) of Mrk 421 make it an excellent laboratory to study blazar emission. The goal is to learn about the physical processes responsible for the typical emission of Mrk 421, which might also be extended to other blazars that are located farther away and hence are more difficult to study.
 Methods. We performed a 4.5-month multi-instrument campaign on Mrk 421 between January 2009 and June 2009, which included VLBA, F-GAMMA, GASP-WEBT, Swift, RXTE, Fermi-LAT, MAGIC, and Whipple, among other instruments and collaborations. This extensive radio to very-high-energy (VHE; E > 100 GeV) gamma-ray dataset provides excellent temporal and energy coverage, which allows detailed studies of the evolution of the broadband spectral energy distribution.
 Results. Mrk421 was found in its typical (non-flaring) activity state, with a VHE flux of about half that of the Crab Nebula, yet the light curves show significant variability at all wavelengths, the highest variability being in the X-rays. We determined the power spectral densities (PSD) at most wavelengths and found that all PSDs can be described by power-laws without a break, and with indices consistent with pink/red-noise behavior. We observed a harder-when-brighter behavior in the X-ray spectra and measured a positive correlation between VHE and X-ray fluxes with zero time lag. Such characteristics have been reported many times during flaring activity, but here they are reported for the first time in the non-flaring state. We also observed an overall anti-correlation between optical /UV and X-rays extending over the duration of the campaign.
 Conclusions. The harder-when-brighter behavior in the X-ray spectra and the measured positive X-ray/VHE correlation during the 2009 multiwavelength campaign suggests that the physical processes dominating the emission during non-flaring states have similarities with those occurring during flaring activity. In particular, this observation supports leptonic scenarios as being responsible for the emission of Mrk 421 during non-flaring activity. Such a temporally extended X-ray /VHE correlation is not driven by any single flaring event, and hence is difficult to explain within the standard hadronic scenarios. The highest variability is observed in the X-ray band, which, within the one-zone synchrotron self-Compton scenario, indicates that the electron energy distribution is most variable at the highest energies.
KW  - BL Lacertae objects: individual: Mrk 421
Y1  - 2015
U6  - https://doi.org/10.1051/0004-6361/201424216
SN  - 0004-6361
SN  - 1432-0746
VL  - 576
PB  - EDP Sciences
CY  - Les Ulis
ER  - 
TY  - JOUR
A1  - Abeysekara, A. U.
A1  - Archer, A.
A1  - Benbow, Wystan
A1  - Bird, Ralph
A1  - Brose, Robert
A1  - Buchovecky, M.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Chromey, A. J.
A1  - Connolly, M. P.
A1  - Cui, Wei
A1  - Daniel, M. K.
A1  - Falcone, A.
A1  - Feng, Qi
A1  - Finley, John P.
A1  - Fortson, L.
A1  - Furniss, Amy
A1  - Huetten, M.
A1  - Hanna, David
A1  - Hervet, O.
A1  - Holder, J.
A1  - Hughes, G.
A1  - Humensky, T. B.
A1  - Johnson, Caitlin A.
A1  - Kaaret, Philip
A1  - Kar, P.
A1  - Kertzman, M.
A1  - Kieda, David
A1  - Krause, M.
A1  - Krennrich, F.
A1  - Kumar, S.
A1  - Lang, M. J.
A1  - Lin, T. T. Y.
A1  - McArthur, S.
A1  - Moriarty, P.
A1  - Mukherjee, Reshmi
A1  - Ong, R. A.
A1  - Otte, Adam Nepomuk
A1  - Park, Nahee
A1  - Petrashyk, A.
A1  - Pohl, Martin
A1  - Pueschel, Elisa
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reynolds, P. T.
A1  - Richards, Gregory T.
A1  - Roache, E.
A1  - Rulten, C.
A1  - Sadeh, I.
A1  - Santander, Marcos
A1  - Sembroski, G. H.
A1  - Shahinyan, Karlen
A1  - Sushch, I.
A1  - Tyler, J.
A1  - Wakely, S. P.
A1  - Weinstein, A.
A1  - Wells, R. M.
A1  - Wilcox, P.
A1  - Wilhelm, Alina
A1  - Williams, D. A.
A1  - Williamson, T. J.
A1  - Zitzer, B.
A1  - Abdollahi, S.
A1  - Ajello, Marco
A1  - Baldini, Luca
A1  - Barbiellini, G.
A1  - Bastieri, Denis
A1  - Bellazzini, Ronaldo
A1  - Berenji, B.
A1  - Bissaldi, Elisabetta
A1  - Blandford, R. D.
A1  - Bonino, R.
A1  - Bottacini, E.
A1  - Brandt, Terri J.
A1  - Bruel, P.
A1  - Buehler, R.
A1  - Cameron, R. A.
A1  - Caputo, R.
A1  - Caraveo, P. A.
A1  - Castro, D.
A1  - Cavazzuti, E.
A1  - Charles, Eric
A1  - Chiaro, G.
A1  - Ciprini, S.
A1  - Cohen-Tanugi, Johann
A1  - Costantin, D.
A1  - Cutini, S.
A1  - de Palma, F.
A1  - Di Lalla, N.
A1  - Di Mauro, M.
A1  - Di Venere, L.
A1  - Dominguez, A.
A1  - Favuzzi, C.
A1  - Fegan, S. J.
A1  - Franckowiak, Anna
A1  - Fukazawa, Yasushi
A1  - Funk, Stefan
A1  - Fusco, Piergiorgio
A1  - Gargano, Fabio
A1  - Gasparrini, Dario
A1  - Giglietto, Nicola
A1  - Giordano, F.
A1  - Giroletti, Marcello
A1  - Green, D.
A1  - Grenier, I. A.
A1  - Guillemot, L.
A1  - Guiriec, Sylvain
A1  - Hays, Elizabeth
A1  - Hewitt, John W.
A1  - Horan, D.
A1  - Johannesson, G.
A1  - Kensei, S.
A1  - Kuss, M.
A1  - Larsson, Stefan
A1  - Latronico, L.
A1  - Lemoine-Goumard, Marianne
A1  - Li, J.
A1  - Longo, Francesco
A1  - Loparco, Francesco
A1  - Lovellette, M. N.
A1  - Lubrano, Pasquale
A1  - Magill, Jeffrey D.
A1  - Maldera, Simone
A1  - Mazziotta, Mario Nicola
A1  - McEnery, J. E.
A1  - Michelson, P. F.
A1  - Mitthumsiri, W.
A1  - Mizuno, Tsunefumi
A1  - Monzani, Maria Elena
A1  - Morselli, Aldo
A1  - Moskalenko, Igor V.
A1  - Negro, M.
A1  - Nuss, E.
A1  - Ojha, R.
A1  - Omodei, Nicola
A1  - Orienti, M.
A1  - Orlando, E.
A1  - Palatiello, M.
A1  - Paliya, Vaidehi S.
A1  - Paneque, D.
A1  - Perkins, Jeremy S.
A1  - Persic, M.
A1  - Pesce-Rollins, Melissa
A1  - Petrosian, Vahe'
A1  - Piron, F.
A1  - Porter, Troy A.
A1  - Principe, G.
A1  - Raino, S.
A1  - Rando, Riccardo
A1  - Rani, B.
A1  - Razzano, Massimilano
A1  - Razzaque, Soebur
A1  - Reimer, A.
A1  - Reimer, Olaf
A1  - Reposeur, T.
A1  - Sgro, C.
A1  - Siskind, E. J.
A1  - Spandre, Gloria
A1  - Spinelli, P.
A1  - Suson, D. J.
A1  - Tajima, Hiroyasu
A1  - Thayer, J. B.
A1  - Thompson, David J.
A1  - Torres, Diego F.
A1  - Tosti, Gino
A1  - Troja, Eleonora
A1  - Valverde, J.
A1  - Vianello, Giacomo
A1  - Vogel, M.
A1  - Wood, K.
A1  - Yassine, M.
A1  - Alfaro, R.
A1  - Alvarez, C.
A1  - Alvarez, J. D.
A1  - Arceo, R.
A1  - Arteaga-Velazquez, J. C.
A1  - Rojas, D. Avila
A1  - Ayala Solares, H. A.
A1  - Becerril, A.
A1  - Belmont-Moreno, E.
A1  - BenZvi, S. Y.
A1  - Bernal, A.
A1  - Braun, J.
A1  - Brisbois, C.
A1  - Caballero-Mora, K. S.
A1  - Capistran, T.
A1  - Carraminana, A.
A1  - Casanova, Sabrina
A1  - Castillo, M.
A1  - Cotti, U.
A1  - Cotzomi, J.
A1  - Coutino de Leon, S.
A1  - De Leon, C.
A1  - De la Fuente, E.
A1  - Dichiara, S.
A1  - Dingus, B. L.
A1  - DuVernois, M. A.
A1  - Diaz-Velez, J. C.
A1  - Engel, K.
A1  - Enriquez-Rivera, O.
A1  - Fiorino, D. W.
A1  - Fleischhack, H.
A1  - Fraija, N.
A1  - Garcia-Gonzalez, J. A.
A1  - Garfias, F.
A1  - Gonzalez Munoz, A.
A1  - Gonzalez, M. M.
A1  - Goodman, J. A.
A1  - Hampel-Arias, Z.
A1  - Harding, J. P.
A1  - Hernandez, S.
A1  - Hernandez-Almada, A.
A1  - Hona, B.
A1  - Hueyotl-Zahuantitla, F.
A1  - Hui, C. M.
A1  - Huntemeyer, P.
A1  - Iriarte, A.
A1  - Jardin-Blicq, A.
A1  - Joshi, V.
A1  - Kaufmann, S.
A1  - Lara, A.
A1  - Lauer, R. J.
A1  - Lee, W. H.
A1  - Lennarz, D.
A1  - Leon Vargas, H.
A1  - Linnemann, J. T.
A1  - Longinotti, A. L.
A1  - Luis-Raya, G.
A1  - Luna-Garcia, R.
A1  - Lopez-Coto, R.
A1  - Malone, K.
A1  - Marinelli, S. S.
A1  - Martinez, O.
A1  - Martinez-Castellanos, I.
A1  - Martinez-Castro, J.
A1  - Martinez-Huerta, H.
A1  - Matthews, J. A.
A1  - Miranda-Romagnoli, P.
A1  - Moreno, E.
A1  - Mostafa, M.
A1  - Nayerhoda, A.
A1  - Nellen, L.
A1  - Newbold, M.
A1  - Nisa, M. U.
A1  - Noriega-Papaqui, R.
A1  - Pelayo, R.
A1  - Pretz, J.
A1  - Perez-Perez, E. G.
A1  - Ren, Z.
A1  - Rho, C. D.
A1  - Riviere, C.
A1  - Rosa-Gonzalez, D.
A1  - Rosenberg, M.
A1  - Ruiz-Velasco, E.
A1  - Salazar, H.
A1  - Greus, F. Salesa
A1  - Sandoval, A.
A1  - Schneider, M.
A1  - Arroyo, M. Seglar
A1  - Sinnis, G.
A1  - Smith, A. J.
A1  - Springer, R. W.
A1  - Surajbali, P.
A1  - Taboada, Ignacio
A1  - Tibolla, O.
A1  - Tollefson, K.
A1  - Torres, I.
A1  - Ukwatta, Tilan N.
A1  - Villasenor, L.
A1  - Weisgarber, T.
A1  - Westerhoff, Stefan
A1  - Wisher, I. G.
A1  - Wood, J.
A1  - Yapici, Tolga
A1  - Yodh, G.
A1  - Zepeda, A.
A1  - Zhou, H.
T1  - VERITAS and Fermi-LAT Observations of TeV Gamma-Ray Sources Discovered by HAWC in the 2HWC Catalog
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - The High Altitude Water Cherenkov (HAWC) collaboration recently published their 2HWC catalog, listing 39 very high energy (VHE; >100 GeV) gamma-ray sources based on 507 days of observation. Among these, 19 sources are not associated with previously known teraelectronvolt (TeV) gamma-ray sources. We have studied 14 of these sources without known counterparts with VERITAS and Fermi-LAT. VERITAS detected weak gamma-ray emission in the 1 TeV-30 TeV band in the region of DA 495, a pulsar wind nebula coinciding with 2HWC J1953+294, confirming the discovery of the source by HAWC. We did not find any counterpart for the selected 14 new HAWC sources from our analysis of Fermi-LAT data for energies higher than 10 GeV. During the search, we detected gigaelectronvolt (GeV) gamma-ray emission coincident with a known TeV pulsar wind nebula, SNR G54.1+0.3 (VER J1930+188), and a 2HWC source, 2HWC J1930+188. The fluxes for isolated, steady sources in the 2HWC catalog are generally in good agreement with those measured by imaging atmospheric Cherenkov telescopes. However, the VERITAS fluxes for SNR G54.1+0.3, DA 495, and TeV J2032+4130 are lower than those measured by HAWC, and several new HAWC sources are not detected by VERITAS. This is likely due to a change in spectral shape, source extension, or the influence of diffuse emission in the source region.
KW  - gamma rays: general
Y1  - 2018
U6  - https://doi.org/10.3847/1538-4357/aade4e
SN  - 0004-637X
SN  - 1538-4357
VL  - 866
IS  - 1
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Archambault, S.
A1  - Aune, T.
A1  - Behera, B.
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Berger, K.
A1  - Bird, R.
A1  - Biteau, Jonathan
A1  - Bugaev, V.
A1  - Byrum, K.
A1  - Cardenzana, J. V.
A1  - Cerruti, M.
A1  - Chen, Xuhui
A1  - Ciupik, L.
A1  - Connolly, M. P.
A1  - Cui, Wei
A1  - Dumm, J.
A1  - Errando, M.
A1  - Falcone, A.
A1  - Federici, Simone
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Fleischhack, H.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Galante, N.
A1  - Gillanders, G. H.
A1  - Griffin, S.
A1  - Griffiths, S. T.
A1  - Grube, J.
A1  - Gyuk, G.
A1  - Hanna, D.
A1  - Holder, J.
A1  - Hughes, G.
A1  - Humensky, T. B.
A1  - Johnson, C. A.
A1  - Kaaret, P.
A1  - Kertzman, M.
A1  - Khassen, Y.
A1  - Kieda, D.
A1  - Krawczynski, H.
A1  - Krennrich, F.
A1  - Kumar, S.
A1  - Lang, M. J.
A1  - Madhavan, A. S.
A1  - Maier, G.
A1  - McCann, A.
A1  - Meagher, K.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nieto, Daniel
A1  - Ong, R. A.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Pohl, Martin
A1  - Popkow, A.
A1  - Prokoph, H.
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Rajotte, J.
A1  - Reyes, L. C.
A1  - Reynolds, P. T.
A1  - Richards, G. T.
A1  - Roache, E.
A1  - Sembroski, G. H.
A1  - Shahinyan, K.
A1  - Staszak, D.
A1  - Telezhinsky, Igor O.
A1  - Tucci, J. V.
A1  - Tyler, J.
A1  - Varlotta, A.
A1  - Vassiliev, V. V.
A1  - Vincent, S.
A1  - Wakely, S. P.
A1  - Weinstein, A.
A1  - Welsing, R.
A1  - Wilhelm, Alina
A1  - Williams, D. A.
A1  - Ackermann, Margit
A1  - Ajello, M.
A1  - Albert, A.
A1  - Baldini, L.
A1  - Bastieri, D.
A1  - Bellazzini, R.
A1  - Bissaldi, E.
A1  - Bregeon, Johan
A1  - Buehler, R.
A1  - Buson, S.
A1  - Caliandro, G. A.
A1  - Cameron, R. A.
A1  - Caraveo, P. A.
A1  - Cavazzuti, E.
A1  - Charles, E.
A1  - Chiang, J.
A1  - Ciprini, S.
A1  - Claus, R.
A1  - Cutini, S.
A1  - de Angelis, A.
A1  - de Palma, F.
A1  - Dermer, C. D.
A1  - Digel, S. W.
A1  - Di Venere, L.
A1  - Drell, P. S.
A1  - Favuzzi, C.
A1  - Franckowiak, A.
A1  - Fusco, P.
A1  - Gargano, F.
A1  - Gasparrini, D.
A1  - Giglietto, N.
A1  - Giordano, F.
A1  - Giroletti, M.
A1  - Grenier, I. A.
A1  - Guiriec, S.
A1  - Jogler, T.
A1  - Kuss, M.
A1  - Larsson, S.
A1  - Latronico, L.
A1  - Longo, F.
A1  - Loparco, F.
A1  - Lubrano, P.
A1  - Madejski, G. M.
A1  - Mayer, M.
A1  - Mazziotta, Mario Nicola
A1  - Michelson, P. F.
A1  - Mizuno, T.
A1  - Monzani, M. E.
A1  - Morselli, Aldo
A1  - Murgia, S.
A1  - Nuss, E.
A1  - Ohsugi, T.
A1  - Ormes, J. F.
A1  - Paneque, D.
A1  - Perkins, J. S.
A1  - Piron, F.
A1  - Pivato, G.
A1  - Raino, S.
A1  - Razzano, M.
A1  - Reimer, A.
A1  - Reimer, Olaf
A1  - Ritz, S.
A1  - Schaal, M.
A1  - Sgro, C.
A1  - Siskind, E. J.
A1  - Spinelli, P.
A1  - Takahashi, H.
A1  - Tibaldo, L.
A1  - Tinivella, M.
A1  - Troja, E.
A1  - Vianello, G.
A1  - Werner, M.
A1  - Wood, M.
T1  - Deep broadband observations of the distant gamma-ray blazar PKS 1424+240
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics ; Part 2, Letters
N2  - We present deep VERITAS observations of the blazar PKS 1424+240, along with contemporaneous Fermi Large Area Telescope, Swift X-ray Telescope, and Swift UV Optical Telescope data between 2009 February 19 and 2013 June 8. This blazar resides at a redshift of z >= 0.6035, displaying a significantly attenuated gamma-ray flux above 100 GeV due to photon absorption via pair-production with the extragalactic background light. We present more than 100 hr of VERITAS observations over three years, a multiwavelength light curve, and the contemporaneous spectral energy distributions. The source shows a higher flux of (2.1 +/- 0.3) x 10(-7) photons m(-2) s(-1) above 120 GeV in 2009 and 2011 as compared to the flux measured in 2013, corresponding to (1.02 +/- 0.08) x 10-7 photons m(-2) s(-1) above 120 GeV. The measured differential very high energy (VHE; E >= 100 GeV) spectral indices are Gamma = 3.8 +/- 0.3, 4.3 +/- 0.6 and 4.5 +/- 0.2 in 2009, 2011, and 2013, respectively. No significant spectral change across the observation epochs is detected. We find no evidence for variability at gamma-ray opacities of greater than tau = 2, where it is postulated that any variability would be small and occur on timescales longer than a year if hadronic cosmic-ray interactions with extragalactic photon fields provide a secondary VHE photon flux. The data cannot rule out such variability due to low statistics.
KW  - BL Lacertae objects: individual (PKS 1424+240)-cosmic background radiation
KW  - gamma rays: galaxies
Y1  - 2014
U6  - https://doi.org/10.1088/2041-8205/785/1/L16
SN  - 2041-8205
SN  - 2041-8213
VL  - 785
IS  - 1
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Ahnen, M. L.
A1  - Ansoldi, S.
A1  - Antonelli, L. A.
A1  - Arcaro, C.
A1  - Babic, A.
A1  - Banerjee, B.
A1  - Bangale, P.
A1  - Barres de Almeida, U.
A1  - Barrio, J. A.
A1  - Gonzalez, J. Becerra
A1  - Bednarek, W.
A1  - Bernardini, E.
A1  - Berti, A.
A1  - Bhattacharyya, W.
A1  - Blanch, O.
A1  - Bonnoli, G.
A1  - Carosi, R.
A1  - Carosi, A.
A1  - Chatterjee, A.
A1  - Colak, S. M.
A1  - Colin, P.
A1  - Colombo, E.
A1  - Contreras, J. L.
A1  - Cortina, J.
A1  - Covino, S.
A1  - Cumani, P.
A1  - Da Vela, P.
A1  - Dazzi, F.
A1  - De Angelis, A.
A1  - De Lotto, B.
A1  - Delfino, M.
A1  - Delgado, Jose Miguel Martins
A1  - Di Pierro, F.
A1  - Doert, M.
A1  - Dominguez, A.
A1  - Prester, D. Dominis
A1  - Doro, M.
A1  - Glawion, D. Eisenacher
A1  - Engelkemeier, M.
A1  - Ramazani, V. Fallah
A1  - Fernandez-Barral, A.
A1  - Fidalgo, D.
A1  - Fonseca, M. V.
A1  - Font, L.
A1  - Fruck, C.
A1  - Galindo, D.
A1  - Lopez, R. J. Garcia
A1  - Garczarczyk, M.
A1  - Gaug, M.
A1  - Giammaria, P.
A1  - Godinovic, N.
A1  - Gora, D.
A1  - Guberman, D.
A1  - Hadasch, D.
A1  - Hahn, A.
A1  - Hassan, T.
A1  - Hayashida, M.
A1  - Herrera, J.
A1  - Hose, J.
A1  - Hrupec, D.
A1  - Ishio, K.
A1  - Konno, Y.
A1  - Kubo, H.
A1  - Kushida, J.
A1  - Kuvezdic, D.
A1  - Lelas, D.
A1  - Lindfors, E.
A1  - Lombardi, S.
A1  - Longo, F.
A1  - Lopez, M.
A1  - Maggio, C.
A1  - Majumdar, P.
A1  - Makariev, M.
A1  - Maneva, G.
A1  - Manganaro, M.
A1  - Maraschi, L.
A1  - Mariotti, M.
A1  - Martinez, M.
A1  - Mazin, D.
A1  - Menzel, U.
A1  - Minev, M.
A1  - Miranda, J. M.
A1  - Mirzoyan, R.
A1  - Moralejo, A.
A1  - Moreno, V.
A1  - Moretti, E.
A1  - Nagayoshi, T.
A1  - Neustroev, V.
A1  - Niedzwiecki, A.
A1  - Nievas Rosillo, M.
A1  - Nigro, C.
A1  - Nilsson, K.
A1  - Ninci, D.
A1  - Nishijima, K.
A1  - Noda, K.
A1  - Nogues, L.
A1  - Paiano, S.
A1  - Palacio, J.
A1  - Paneque, D.
A1  - Paoletti, R.
A1  - Paredes, J. M.
A1  - Pedaletti, G.
A1  - Peresano, M.
A1  - Perri, L.
A1  - Persic, M.
A1  - Moroni, P. G. Prada
A1  - Prandini, E.
A1  - Puljak, I.
A1  - Garcia, J. R.
A1  - Reichardt, I.
A1  - Ribo, M.
A1  - Rico, J.
A1  - Righi, C.
A1  - Rugliancich, A.
A1  - Saito, T.
A1  - Satalecka, K.
A1  - Schroeder, S.
A1  - Schweizer, T.
A1  - Shore, S. N.
A1  - Sitarek, J.
A1  - Snidaric, I.
A1  - Sobczynska, D.
A1  - Stamerra, A.
A1  - Strzys, M.
A1  - Suric, T.
A1  - Takalo, L.
A1  - Tavecchio, F.
A1  - Temnikov, P.
A1  - Terzic, T.
A1  - Teshima, M.
A1  - Torres-Alba, N.
A1  - Treves, A.
A1  - Tsujimoto, S.
A1  - Vanzo, G.
A1  - Vazquez Acosta, M.
A1  - Vovk, I.
A1  - Ward, J. E.
A1  - Will, M.
A1  - Zaric, D.
A1  - Arbet-Engels, A.
A1  - Baack, D.
A1  - Balbo, M.
A1  - Biland, A.
A1  - Blank, M.
A1  - Bretz, T.
A1  - Bruegge, K.
A1  - Bulinski, M.
A1  - Buss, J.
A1  - Dmytriiev, A.
A1  - Dorner, D.
A1  - Einecke, S.
A1  - Elsaesser, D.
A1  - Herbst, T.
A1  - Hildebrand, D.
A1  - Kortmann, L.
A1  - Linhoff, L.
A1  - Mahlke, M.
A1  - Mannheim, K.
A1  - Mueller, S. A.
A1  - Neise, D.
A1  - Neronov, A.
A1  - Noethe, M.
A1  - Oberkirch, J.
A1  - Paravac, A.
A1  - Rhode, W.
A1  - Schleicher, B.
A1  - Schulz, F.
A1  - Sedlaczek, K.
A1  - Shukla, A.
A1  - Sliusar, V.
A1  - Walter, R.
A1  - Archer, A.
A1  - Benbow, W.
A1  - Bird, R.
A1  - Brose, Robert
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Christiansen, J. L.
A1  - Cui, W.
A1  - Daniel, M. K.
A1  - Falcone, A.
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Gillanders, G. H.
A1  - Gueta, O.
A1  - Hanna, D.
A1  - Hervet, O.
A1  - Holder, J.
A1  - Hughes, G.
A1  - Huetten, M.
A1  - Humensky, T. B.
A1  - Johnson, C. A.
A1  - Kaaret, P.
A1  - Kar, P.
A1  - Kelley-Hoskins, N.
A1  - Kertzman, M.
A1  - Kieda, D.
A1  - Krause, M.
A1  - Krennrich, F.
A1  - Kumar, S.
A1  - Lang, M. J.
A1  - Lin, T. T. Y.
A1  - Maier, G.
A1  - McArthur, S.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Ong, R. A.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Petrashyk, A.
A1  - Pichel, A.
A1  - Pohl, Martin
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reynolds, P. T.
A1  - Richards, G. T.
A1  - Roache, E.
A1  - Rovero, A. C.
A1  - Rulten, C.
A1  - Sadeh, I.
A1  - Santander, M.
A1  - Sembroski, G. H.
A1  - Shahinyan, K.
A1  - Sushch, Iurii
A1  - Tyler, J.
A1  - Wakely, S. P.
A1  - Weinstein, A.
A1  - Wells, R. M.
A1  - Wilcox, P.
A1  - Wilhel, A.
A1  - Williams, D. A.
A1  - Williamson, T. J.
A1  - Zitzer, B.
A1  - Perri, M.
A1  - Verrecchia, F.
A1  - Leto, C.
A1  - Villata, M.
A1  - Raiteri, C. M.
A1  - Jorstad, S. G.
A1  - Larionov, V. M.
A1  - Blinov, D. A.
A1  - Grishina, T. S.
A1  - Kopatskaya, E. N.
A1  - Larionova, E. G.
A1  - Nikiforova, A. A.
A1  - Morozova, D. A.
A1  - Troitskaya, Yu. V.
A1  - Troitsky, I. S.
A1  - Kurtanidze, O. M.
A1  - Nikolashvili, M. G.
A1  - Kurtanidze, S. O.
A1  - Kimeridze, G. N.
A1  - Chigladze, R. A.
A1  - Strigachev, A.
A1  - Sadun, A. C.
T1  - Extreme HBL behavior of Markarian 501 during 2012
JF  - Astronomy and astrophysics : an international weekly journal / European Southern Observatory (ESO)
N2  - Aims. We aim to characterize the multiwavelength emission from Markarian 501 (Mrk 501), quantify the energy-dependent variability, study the potential multiband correlations, and describe the temporal evolution of the broadband emission within leptonic theoretical scenarios. Methods. We organized a multiwavelength campaign to take place between March and July of 2012. Excellent temporal coverage was obtained with more than 25 instruments, including the MAGIC, FACT and VERITAS Cherenkov telescopes, the instruments on board the Swift and Fermi spacecraft, and the telescopes operated by the GASP-WEBT collaboration. Results. Mrk 501 showed a very high energy (VHE) gamma-ray flux above 0.2 TeV of similar to 0.5 times the Crab Nebula flux (CU) for most of the campaign. The highest activity occurred on 2012 June 9, when the VHE flux was similar to 3 CU, and the peak of the high-energy spectral component was found to be at similar to 2 TeV. Both the X-ray and VHE gamma-ray spectral slopes were measured to be extremely hard, with spectral indices <2 during most of the observing campaign, regardless of the X-ray and VHE flux. This study reports the hardest Mrk 501 VHE spectra measured to date. The fractional variability was found to increase with energy, with the highest variability occurring at VHE. Using the complete data set, we found correlation between the X-ray and VHE bands; however, if the June 9 flare is excluded, the correlation disappears (significance <3 sigma) despite the existence of substantial variability in the X-ray and VHE bands throughout the campaign. Conclusions. The unprecedentedly hard X-ray and VHE spectra measured imply that their low- and high-energy components peaked above 5 keV and 0.5 TeV, respectively, during a large fraction of the observing campaign, and hence that Mrk 501 behaved like an extreme high-frequency-peaked blazar (EHBL) throughout the 2012 observing season. This suggests that being an EHBL may not be a permanent characteristic of a blazar, but rather a state which may change over time. The data set acquired shows that the broadband spectral energy distribution (SED) of Mrk 501, and its transient evolution, is very complex, requiring, within the framework of synchrotron self-Compton (SSC) models, various emission regions for a satisfactory description. Nevertheless the one-zone SSC scenario can successfully describe the segments of the SED where most energy is emitted, with a significant correlation between the electron energy density and the VHE gamma-ray activity, suggesting that most of the variability may be explained by the injection of high-energy electrons. The one-zone SSC scenario used reproduces the behavior seen between the measured X-ray and VHE gamma-ray fluxes, and predicts that the correlation becomes stronger with increasing energy of the X-rays.
KW  - astroparticle physics
KW  - acceleration of particles
KW  - radiation mechanisms: non-thermal
KW  - BL Lacertae objects: general
KW  - BL Lacertae objects: individual: Mrk501
Y1  - 2018
U6  - https://doi.org/10.1051/0004-6361/201833704
SN  - 1432-0746
VL  - 620
PB  - EDP Sciences
CY  - Les Ulis
ER  - 
TY  - JOUR
A1  - Abeysekara, A. U.
A1  - Benbow, Wystan
A1  - Bird, Ralph
A1  - Brill, A.
A1  - Brose, Robert
A1  - Buckley, J. H.
A1  - Chromey, A. J.
A1  - Daniel, M. K.
A1  - Falcone, A.
A1  - Finley, J. P.
A1  - Fortson, L.
A1  - Furniss, Amy
A1  - Gent, A.
A1  - Gillanders, Gerald H.
A1  - Hanna, David
A1  - Hassan, T.
A1  - Hervet, O.
A1  - Holder, J.
A1  - Hughes, G.
A1  - Humensky, T. B.
A1  - Kaaret, Philip
A1  - Kar, P.
A1  - Kertzman, M.
A1  - Kieda, David
A1  - Krause, Maria
A1  - Krennrich, F.
A1  - Kumar, S.
A1  - Lang, M. J.
A1  - Lin, T. T. Y.
A1  - Maier, Gernot
A1  - Moriarty, P.
A1  - Mukherjee, Reshmi
A1  - Ong, R. A.
A1  - Otte, Adam Nepomuk
A1  - Park, Nahee
A1  - Petrashyk, A.
A1  - Pohl, Martin
A1  - Pueschel, Elisa
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Richards, Gregory T.
A1  - Roache, E.
A1  - Sadeh, I.
A1  - Santander, Marcos
A1  - Schlenstedt, S.
A1  - Sembroski, G. H.
A1  - Sushch, Iurii
A1  - Tyler, J.
A1  - Vassiliev, V. V.
A1  - Wakely, S. P.
A1  - Weinstein, A.
A1  - Wells, R. M.
A1  - Wilcox, P.
A1  - Wilhelm, Alina
A1  - Williams, David A.
A1  - Williamson, T. J.
A1  - Zitzer, B.
A1  - Acciari, V. A.
A1  - Ansoldi, S.
A1  - Antonelli, L. A.
A1  - Engels, A. Arbet
A1  - Baack, D.
A1  - Babic, A.
A1  - Banerjee, B.
A1  - de Almeida, U. Barres
A1  - Barrio, J. A.
A1  - Becerra Gonzalez, Josefa
A1  - Bednarek, Wlodek
A1  - Bernardini, Elisa
A1  - Berti, A.
A1  - Besenrieder, J.
A1  - Bhattacharyya, W.
A1  - Bigongiari, C.
A1  - Biland, A.
A1  - Blanch, O.
A1  - Bonnoli, G.
A1  - Busetto, G.
A1  - Carosi, R.
A1  - Ceribella, G.
A1  - Cikota, S.
A1  - Colak, S. M.
A1  - Colin, P.
A1  - Colombo, E.
A1  - Contreras, J. L.
A1  - Cortina, J.
A1  - Covino, S.
A1  - Da Vela, P.
A1  - Dazzi, F.
A1  - De Angelis, A.
A1  - De Lotto, B.
A1  - Delfino, M.
A1  - Delgado, J.
A1  - Di Pierro, F.
A1  - Do Souto Espinera, E.
A1  - Dominguez, A.
A1  - Prester, D. Dominis
A1  - Dorner, D.
A1  - Doro, M.
A1  - Einecke, S.
A1  - Elsaesser, D.
A1  - Ramazani, V. Fallah
A1  - Fattorini, A.
A1  - Fernandez-Barral, A.
A1  - Ferrara, G.
A1  - Fidalgo, D.
A1  - Foffano, L.
A1  - Fonseca, M. V.
A1  - Font, L.
A1  - Fruck, C.
A1  - Galindo, D.
A1  - Gallozzi, S.
A1  - Lopez, R. J. Garcia
A1  - Garczarczyk, M.
A1  - Gasparyan, S.
A1  - Gaug, Markus
A1  - Giammaria, P.
A1  - Godinovic, N.
A1  - Guberman, D.
A1  - Hadasch, D.
A1  - Hahn, A.
A1  - Herrera, J.
A1  - Hoang, J.
A1  - Hrupec, D.
A1  - Inoue, S.
A1  - Ishio, K.
A1  - Iwamura, Y.
A1  - Kubo, H.
A1  - Kushida, J.
A1  - Kuvezdic, D.
A1  - Lamastra, A.
A1  - Lelas, D.
A1  - Leone, Francesco
A1  - Lindfors, E.
A1  - Lombardi, S.
A1  - Longo, Francesco
A1  - Lopez, M.
A1  - Lopez-Oramas, A.
A1  - Machado de Oliveira Fraga, B.
A1  - Maggio, C.
A1  - Majumdar, P.
A1  - Makariev, M.
A1  - Mallamaci, M.
A1  - Maneva, G.
A1  - Manganaro, M.
A1  - Mannheim, K.
A1  - Maraschi, L.
A1  - Mariotti, M.
A1  - Martinez, M.
A1  - Masuda, S.
A1  - Mazin, D.
A1  - Minev, M.
A1  - Miranda, J. M.
A1  - Mirzoyan, R.
A1  - Molina, E.
A1  - Moralejo, A.
A1  - Moreno, V.
A1  - Moretti, E.
A1  - Munar-Adrover, Pere
A1  - Neustroev, V.
A1  - Niedzwiecki, Andrzej
A1  - Rosillo, Mireia Nievas
A1  - Nigro, C.
A1  - Nilsson, Kari
A1  - Ninci, D.
A1  - Nishijima, K.
A1  - Noda, K.
A1  - Nogues, L.
A1  - Noethe, M.
A1  - Paiano, Simona
A1  - Palacio, J.
A1  - Paneque, D.
A1  - Paoletti, R.
A1  - Paredes, J. M.
A1  - Pedaletti, G.
A1  - Penil, P.
A1  - Peresano, M.
A1  - Persic, M.
A1  - Moroni, P. G. Prada
A1  - Prandini, E.
A1  - Puljak, I.
A1  - Garcia, J. R.
A1  - Rhode, W.
A1  - Ribo, Marc
A1  - Rico, J.
A1  - Righi, C.
A1  - Rugliancich, A.
A1  - Saha, Lab
A1  - Sahakyan, Narek
A1  - Saito, T.
A1  - Satalecka, K.
A1  - Schweizer, T.
A1  - Sitarek, J.
A1  - Snidaric, I.
A1  - Sobczynska, D.
A1  - Somero, A.
A1  - Stamerra, A.
A1  - Strzys, M.
A1  - Suric, T.
A1  - Tavecchio, Fabrizio
A1  - Temnikov, P.
A1  - Terzic, T.
A1  - Teshima, M.
A1  - Torres-Alba, N.
A1  - Tsujimoto, S.
A1  - van Scherpenberg, J.
A1  - Vanzo, G.
A1  - Vazquez Acosta, M.
A1  - Vovk, I.
A1  - Will, M.
A1  - Zaric, D.
T1  - Periastron Observations of TeV Gamma-Ray Emission from a Binary System with a 50-year Period
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics ; Part 2, Letters
N2  - We report on observations of the pulsar/Be star binary system PSR J2032+4127/MT91 213 in the energy range between 100 GeV and 20 TeV with the Very Energetic Radiation Imaging Telescope Array and Major Atmospheric Gamma Imaging Cherenkov telescope arrays. The binary orbit has a period of approximately 50 years, with the most recent periastron occurring on 2017 November 13. Our observations span from 18 months prior to periastron to one month after. A new point-like gamma-ray source is detected, coincident with the location of PSR J2032+4127/MT91 213. The gamma-ray light curve and spectrum are well characterized over the periastron passage. The flux is variable over at least an order of magnitude, peaking at periastron, thus providing a firm association of the TeV source with the pulsar/Be star system. Observations prior to periastron show a cutoff in the spectrum at an energy around 0.5 TeV. This result adds a new member to the small population of known TeV binaries, and it identifies only the second source of this class in which the nature and properties of the compact object are firmly established. We compare the gamma-ray results with the light curve measured with the X-ray Telescope on board the Neil Gehrels Swift Observatory and with the predictions of recent theoretical models of the system. We conclude that significant revision of the models is required to explain the details of the emission that we have observed, and we discuss the relationship between the binary system and the overlapping steady extended source, TeV J2032+4130.
KW  - gamma rays: general
KW  - pulsars: individual (PSR J2032+4127, VER J2032+414, MAGIC J2032+4127)
KW  - stars: individual (MT91 213)
KW  - X-rays: binaries
Y1  - 2018
U6  - https://doi.org/10.3847/2041-8213/aae70e
SN  - 2041-8205
SN  - 2041-8213
VL  - 867
IS  - 1
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Archambault, S.
A1  - Arlen, T.
A1  - Aune, T.
A1  - Behera, B.
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Bird, R.
A1  - Bouvier, A.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Byrum, K.
A1  - Cesarini, A.
A1  - Ciupik, L.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Errando, M.
A1  - Falcone, A.
A1  - Federici, Simone
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Galante, N.
A1  - Gall, D.
A1  - Gillanders, G. H.
A1  - Griffin, S.
A1  - Grube, J.
A1  - Gyuk, G.
A1  - Hanna, D.
A1  - Holder, J.
A1  - Hughes, G.
A1  - Humensky, T. B.
A1  - Kaaret, P.
A1  - Kertzman, M.
A1  - Khassen, Y.
A1  - Kieda, D.
A1  - Krawczynski, H.
A1  - Krennrich, F.
A1  - Kumar, S.
A1  - Lang, M. J.
A1  - Madhavan, A. S.
A1  - Maier, G.
A1  - Majumdar, P.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Millis, J.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - de Bhroithe, A. O'Faolain
A1  - Ong, R. A.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Perkins, J. S.
A1  - Pohl, Martin
A1  - Popkow, A.
A1  - Prokoph, H.
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reyes, L. C.
A1  - Reynolds, P. T.
A1  - Richards, G. T.
A1  - Roache, E.
A1  - Saxon, D. B.
A1  - Sembroski, G. H.
A1  - Smith, A. W.
A1  - Staszak, D.
A1  - Telezhinsky, Igor O.
A1  - Theiling, M.
A1  - Varlotta, A.
A1  - Vassiliev, V. V.
A1  - Vincent, S.
A1  - Wakely, S. P.
A1  - Weekes, T. C.
A1  - Weinstein, A.
A1  - Welsing, R.
A1  - Williams, D. A.
A1  - Zitzer, B.
A1  - Boettcher, Markus
A1  - Fegan, S. J.
A1  - Fortin, P.
A1  - Halpern, J. P.
A1  - Kovalev, Y. Y.
A1  - Lister, M. L.
A1  - Liu, J.
A1  - Pushkarev, A. B.
A1  - Smith, P. S.
T1  - Discovery of a new tev Gamma-Ray source - VER J0521+211
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - 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.
KW  - BL Lacertae objects: individual (VER J0521+211)
KW  - gamma rays: galaxies
Y1  - 2013
U6  - https://doi.org/10.1088/0004-637X/776/2/69
SN  - 0004-637X
SN  - 1538-4357
VL  - 776
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Archambault, S.
A1  - Archer, A.
A1  - Barnacka, Anna
A1  - Behera, B.
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Berger, K.
A1  - Bird, R.
A1  - Böttcher, Markus
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Cardenzana, J. V.
A1  - Cerruti, M.
A1  - Chen, Xuhui
A1  - Christiansen, J. L.
A1  - Ciupik, L.
A1  - Collins-Hughes, E.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Dickinson, H. J.
A1  - Dumm, J.
A1  - Eisch, J. D.
A1  - Errando, M.
A1  - Falcone, A.
A1  - Federici, Simone
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Fleischhack, H.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Gillanders, G. H.
A1  - Godambe, S.
A1  - Griffin, S.
A1  - Griffiths, S. T.
A1  - Grube, J.
A1  - Gyuk, G.
A1  - Hakansson, Nils
A1  - Hanna, D.
A1  - Holder, J.
A1  - Hughes, G.
A1  - Johnson, C. A.
A1  - Kaaret, P.
A1  - Kar, P.
A1  - Kertzman, M.
A1  - Khassen, Y.
A1  - Kieda, D.
A1  - Krawczynski, H.
A1  - Kumar, S.
A1  - Lang, M. J.
A1  - Madhavan, A. S.
A1  - Maier, G.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Meagher, K.
A1  - Millis, J.
A1  - Moriarty, P.
A1  - Nelson, T.
A1  - Nieto, D.
A1  - Ong, R. A.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Perkins, J. S.
A1  - Pohl, Martin
A1  - Popkow, A.
A1  - Prokoph, H.
A1  - Pueschel, Elisa
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Rajotte, J.
A1  - Reyes, L. C.
A1  - Reynolds, P. T.
A1  - Richards, G. T.
A1  - Roache, E.
A1  - Sembroski, G. H.
A1  - Shahinyan, K.
A1  - Smith, A. W.
A1  - Staszak, D.
A1  - Sweeney, K.
A1  - Telezhinsky, Igor O.
A1  - Tucci, J. V.
A1  - Tyler, J.
A1  - Varlotta, A.
A1  - Vassiliev, V. V.
A1  - Wakely, S. P.
A1  - Welsing, R.
A1  - Wilhelm, Alina
A1  - Williams, D. A.
A1  - Zitzer, B.
T1  - Discovery of very high energy gamma rays from 1ES 1440+122
JF  - Monthly notices of the Royal Astronomical Society
KW  - BL Lacertae objects: general
KW  - gamma-rays: general
Y1  - 2016
U6  - https://doi.org/10.1093/mnras/stw1319
SN  - 0035-8711
SN  - 1365-2966
VL  - 461
SP  - 202
EP  - 208
PB  - Oxford Univ. Press
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Aliu, E.
A1  - Archambault, S.
A1  - Archer, A.
A1  - Aune, T.
A1  - Barnacka, Anna
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Bird, R.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Byrum, K.
A1  - Cardenzana, J. V.
A1  - Cerruti, M.
A1  - Chen, Xuhui
A1  - Ciupik, L.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Dickinson, H. J.
A1  - Dumm, J.
A1  - Eisch, J. D.
A1  - Errando, M.
A1  - Falcone, A.
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Fleischhack, H.
A1  - Fortin, P.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Gillanders, G. H.
A1  - Griffin, S.
A1  - Griffiths, S. T.
A1  - Grube, J.
A1  - Gyuk, G.
A1  - Kansson, N. H. A.
A1  - Hanna, D.
A1  - Holder, J.
A1  - Humensky, T. B.
A1  - Johnson, C. A.
A1  - Kaaret, P.
A1  - Kar, P.
A1  - Kertzman, M.
A1  - Kieda, D.
A1  - Krennrich, F.
A1  - Kumar, S.
A1  - Lang, M. J.
A1  - Lyutikov, M.
A1  - Madhavan, A. S.
A1  - Maier, G.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Meagher, K.
A1  - Millis, J.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nieto, D.
A1  - Ong, R. A.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Pohl, Manuela
A1  - Popkow, A.
A1  - Prokoph, H.
A1  - Pueschel, Elisa
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reyes, L. C.
A1  - Reynolds, P. T.
A1  - Richards, G. T.
A1  - Roache, E.
A1  - Santander, M.
A1  - Sembroski, G. H.
A1  - Shahinyan, K.
A1  - Smith, A. W.
A1  - Staszak, D.
A1  - Telezhinsky, Igor O.
A1  - Tucci, J. V.
A1  - Tyler, J.
A1  - Varlotta, A.
A1  - Vincent, S.
A1  - Wakely, S. P.
A1  - Weinstein, A.
A1  - Williams, D. A.
A1  - Zajczyk, A.
A1  - Zitzer, B.
T1  - A search for pulsations from geminga above 100 GeV with veritas
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - We present the results of 71.6 hr of observations of the Geminga pulsar (PSR J0633+1746) with the VERITAS very-high-energy gamma-ray telescope array. Data taken with VERITAS between 2007 November and 2013 February were phase-folded using a Geminga pulsar timing solution derived from data recorded by the XMM-Newton and Fermi-LAT space telescopes. No significant pulsed emission above 100 GeV is observed, and we report upper limits at the 95% confidence level on the integral flux above 135 GeV (spectral analysis threshold) of 4.0x10(-13) s(-1) cm(-2) and 1.7 x 10(-13) s(-1) cm(-2) for the two principal peaks in the emission profile. These upper limits, placed in context with phase-resolved spectral energy distributions determined from 5 yr of data from the Fermi-Large Area Telescope (LAT), constrain possible hardening of the Geminga pulsar emission spectra above similar to 50 GeV.
KW  - gamma rays: stars
KW  - pulsars: general
KW  - pulsars: individual (PSR J0633+1746, Geminga)
Y1  - 2015
U6  - https://doi.org/10.1088/0004-637X/800/1/61
SN  - 0004-637X
SN  - 1538-4357
VL  - 800
IS  - 1
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Aliu, E.
A1  - Archambault, S.
A1  - Aune, T.
A1  - Benbow, W.
A1  - Berger, K.
A1  - Bird, R.
A1  - Bouvier, A.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Byrum, K.
A1  - Cerruti, M.
A1  - Chen, Xuhui
A1  - Ciupik, L.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Dumm, J.
A1  - Errando, M.
A1  - Falcone, A.
A1  - Federici, Simone
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Fortin, P.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Galante, N.
A1  - Gillanders, G. H.
A1  - Griffin, S.
A1  - Griffiths, S. T.
A1  - Grube, J.
A1  - Gyuk, G.
A1  - Hanna, D.
A1  - Holder, J.
A1  - Hughes, G.
A1  - Humensky, T. B.
A1  - Kaaret, P.
A1  - Kertzman, M.
A1  - Khassen, Y.
A1  - Kieda, D.
A1  - Krennrich, F.
A1  - Kumar, S.
A1  - Lang, M. J.
A1  - Lyutikov, M.
A1  - Maier, G.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Meagher, K.
A1  - Millis, J.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Ong, R. A.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Perkins, J. S.
A1  - Pohl, M.
A1  - Popkow, A.
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Rajotte, J.
A1  - Reyes, L. C.
A1  - Reynolds, P. T.
A1  - Richards, G. T.
A1  - Roache, E.
A1  - Sembroski, G. H.
A1  - Sheidaei, F.
A1  - Smith, A. W.
A1  - Staszak, D.
A1  - Telezhinsky, Igor O.
A1  - Theiling, M.
A1  - Tucci, J. V.
A1  - Tyler, J.
A1  - Varlotta, A.
A1  - Wakely, S. P.
A1  - Weekes, T. C.
A1  - Weinstein, A.
A1  - Welsing, R.
A1  - Williams, D. A.
A1  - Zajczyk, A.
A1  - Zitzer, B.
T1  - A search for enhanced very high energy GAMMA-RAY emission from the 2013 march crab nebula flare
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics ; Part 2, Letters
N2  - In 2013 March, a flaring episode from the Crab Nebula lasting similar to 2 weeks was detected by Fermi-LAT (Large Area Telescope on board the Fermi Gamma-ray Space Telescope). The Very Energetic Radiation Imaging Telescope Array System (VERITAS) provides simultaneous observations throughout this period. During the flare, Fermi-LAT detected a 20 fold increase in flux above the average synchrotron flux >100 MeV seen from the Crab Nebula. Simultaneous measurements with VERITAS are consistent with the non-variable long-term average Crab Nebula flux at TeV energies. Assuming a linear correlation between the very high energy flux change >1 TeV and the flux change seen in the Fermi-LAT band >100 MeV during the period of simultaneous observations, the linear correlation factor can be constrained to be at most 8.6 x 10(-3) with 95% confidence.
KW  - gamma rays: general
KW  - ISM: individual objects (Crab Nebula)
Y1  - 2014
U6  - https://doi.org/10.1088/2041-8205/781/1/L11
SN  - 2041-8205
SN  - 2041-8213
VL  - 781
IS  - 1
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Archer, A.
A1  - Barnacka, Anna
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Berger, K.
A1  - Bird, R.
A1  - Biteau, Jonathan
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Byrum, K.
A1  - Cardenzana, J. V.
A1  - Cerruti, M.
A1  - Chen, W.
A1  - Chen, Xiaoming
A1  - Ciupik, L.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Dickinson, H. J.
A1  - Dumm, J.
A1  - Eisch, J. D.
A1  - Falcone, A.
A1  - Federici, Simone
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Fleischhack, H.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Galante, N.
A1  - Griffin, S.
A1  - Griffiths, S. T.
A1  - Grube, J.
A1  - Gyuk, G.
A1  - Hakansson, Nils
A1  - Hanna, D.
A1  - Holder, J.
A1  - Hughes, G.
A1  - Johnson, C. A.
A1  - Kaaret, P.
A1  - Kar, P.
A1  - Kertzman, M.
A1  - Khassen, Y.
A1  - Kieda, D.
A1  - Krawczynski, H.
A1  - Kumar, S.
A1  - Lang, M. J.
A1  - Maier, G.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Meagher, K.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nieto, D.
A1  - Ong, R. A.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Perkins, J. S.
A1  - Pohl, Manuela
A1  - Popkow, A.
A1  - Prokoph, H.
A1  - Pueschel, Elisa
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Rajotte, J.
A1  - Reyes, L. C.
A1  - Reynolds, P. T.
A1  - Richards, G. T.
A1  - Roache, E.
A1  - Sembroski, G. H.
A1  - Shahinyan, K.
A1  - Smith, A. W.
A1  - Staszak, D.
A1  - Telezhinsky, Igor O.
A1  - Tucci, J. V.
A1  - Tyler, J.
A1  - Varlotta, A.
A1  - Vincent, S.
A1  - Wakely, S. P.
A1  - Weinstein, A.
A1  - Welsing, R.
A1  - Wilhelm, Alina
A1  - Williams, D. A.
A1  - Zajczyk, A.
A1  - Zitzer, B.
T1  - Very-high energy observations of the galactic center region by veritas IN 2010-2012
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - The Galactic center is an interesting region for high-energy (0.1-100 GeV) and very-high-energy (E > 100 GeV) gamma-ray observations. Potential sources of GeV/TeV gamma-ray emission have been suggested, e.g., the accretion of matter onto the supermassive black hole, cosmic rays from a nearby supernova remnant (e.g., Sgr A East), particle acceleration in a plerion, or the annihilation of dark matter particles. The Galactic center has been detected by EGRET and by Fermi/LAT in the MeV/GeV energy band. At TeV energies, the Galactic center was detected with moderate significance by the CANGAROO and Whipple 10 m telescopes and with high significance by H.E.S.S., MAGIC, and VERITAS. We present the results from three years of VERITAS observations conducted at large zenith angles resulting in a detection of the Galactic center on the level of 18 standard deviations at energies above similar to 2.5 TeV. The energy spectrum is derived and is found to be compatible with hadronic, leptonic, and hybrid emission models discussed in the literature. Future, more detailed measurements of the high-energy cutoff and better constraints on the high-energy flux variability will help to refine and/or disentangle the individual models.
KW  - astroparticle physics
KW  - black hole physics
KW  - Galaxy: center
KW  - gamma rays: galaxies
KW  - methods: data analysis
KW  - radiation mechanisms: non-thermal
Y1  - 2014
U6  - https://doi.org/10.1088/0004-637X/790/2/149
SN  - 0004-637X
SN  - 1538-4357
VL  - 790
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Archambault, S.
A1  - Archer, A.
A1  - Benbow, W.
A1  - Bird, R.
A1  - Biteau, Jonathan
A1  - Buchovecky, M.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Byrum, K.
A1  - Cerruti, M.
A1  - Chen, Xuhui
A1  - Ciupik, L.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Eisch, J. D.
A1  - Errando, M.
A1  - Falcone, A.
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Fleischhack, H.
A1  - Fortin, P.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Gillanders, G. H.
A1  - Griffin, S.
A1  - Grube, J.
A1  - Gyuk, G.
A1  - Huetten, M.
A1  - Hakansson, Nils
A1  - Hanna, D.
A1  - Holder, J.
A1  - Humensky, T. B.
A1  - Johnson, C. A.
A1  - Kaaret, P.
A1  - Kar, P.
A1  - Kelley-Hoskins, N.
A1  - Kertzman, M.
A1  - Kieda, D.
A1  - Krause, M.
A1  - Krennrich, F.
A1  - Kumar, S.
A1  - Lang, M. J.
A1  - Maier, G.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Meagher, K.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nguyen, T.
A1  - Nieto, D.
A1  - Ong, R. A.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Perkins, J. S.
A1  - Pichel, A.
A1  - Pohl, Martin
A1  - Popkow, A.
A1  - Pueschel, Elisa
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reynolds, P. T.
A1  - Richards, G. T.
A1  - Roache, E.
A1  - Rovero, A. C.
A1  - Santander, M.
A1  - Sembroski, G. H.
A1  - Shahinyan, K.
A1  - Smith, A. W.
A1  - Staszak, D.
A1  - Telezhinsky, Igor O.
A1  - Tucci, J. V.
A1  - Tyler, J.
A1  - Vincent, S.
A1  - Wakely, S. P.
A1  - Weiner, O. M.
A1  - Weinstein, A.
A1  - Williams, D. A.
A1  - Zitzer, B.
A1  - Fumagalli, M.
A1  - Prochaska, J. X.
T1  - UPPER LIMITS FROM FIVE YEARS OF BLAZAR OBSERVATIONS WITH THE VERITAS CHERENKOV TELESCOPES
JF  - The astronomical journal
N2  - Between the beginning of its full-scale scientific operations in 2007 and 2012, the VERITAS Cherenkov telescope array observed more than 130 blazars; of these, 26 were detected as very-high-energy (VHE; E > 100 GeV) gamma-ray sources. In this work, we present the analysis results of a sample of 114 undetected objects. The observations constitute a total live-time of similar to 570 hr. The sample includes several unidentified Fermi-Large Area Telescope (LAT) sources (located at high Galactic latitude) as well as all the sources from the second Fermi-LAT catalog that are contained within the field of view of the VERITAS observations. We have also performed optical spectroscopy measurements in order to estimate the redshift of some of these blazars that do not have spectroscopic distance estimates. We present new optical spectra from the Kast instrument on the Shane telescope at the Lick observatory for 18 blazars included in this work, which allowed for the successful measurement or constraint on the redshift of four of them. For each of the blazars included in our sample, we provide the flux upper limit in the VERITAS energy band. We also study the properties of the significance distributions and we present the result of a stacked analysis of the data set, which shows a 4s excess.
KW  - BL Lacertae objects: general
KW  - galaxies: active
KW  - gamma rays: galaxies
KW  - radiation mechanisms: non-thermal
Y1  - 2016
U6  - https://doi.org/10.3847/0004-6256/151/6/142
SN  - 0004-6256
SN  - 1538-3881
VL  - 151
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Aliu, E.
A1  - Archambault, S.
A1  - Aune, T.
A1  - Behera, B.
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Berger, K.
A1  - Bird, R.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Cardenzana, J. V.
A1  - Cerruti, M.
A1  - Chen, Xuhui
A1  - Ciupik, L.
A1  - Collins-Hughes, E.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Dumm, J.
A1  - Dwarkadas, Vikram V.
A1  - Errando, M.
A1  - Falcone, A.
A1  - Federici, Simone
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Fleischhack, H.
A1  - Fortin, P.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Galante, N.
A1  - Gall, D.
A1  - Gillanders, G. H.
A1  - Griffin, S.
A1  - Griffiths, S. T.
A1  - Grube, J.
A1  - Gyuk, G.
A1  - Hanna, D.
A1  - Holder, J.
A1  - Hughes, G.
A1  - Humensky, T. B.
A1  - Kaaret, P.
A1  - Kertzman, M.
A1  - Khassen, Y.
A1  - Kieda, D.
A1  - Krennrich, F.
A1  - Kumar, S.
A1  - Lang, M. J.
A1  - Madhavan, A. S.
A1  - Maier, G.
A1  - McCann, A. J.
A1  - Meagher, K.
A1  - Millis, J.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nieto, D.
A1  - Ong, R. A.
A1  - Otte, A. N.
A1  - Pandel, D.
A1  - Park, N.
A1  - Pohl, Martin
A1  - Popkow, A.
A1  - Prokoph, H.
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Rajotte, J.
A1  - Ratliff, G.
A1  - Reyes, L. C.
A1  - Reynolds, P. T.
A1  - Richards, G. T.
A1  - Roache, E.
A1  - Rousselle, J.
A1  - Sembroski, G. H.
A1  - Shahinyan, K.
A1  - Sheidaei, F.
A1  - Smith, A. W.
A1  - Staszak, D.
A1  - Telezhinsky, Igor O.
A1  - Tsurusaki, K.
A1  - Tucci, J. V.
A1  - Tyler, J.
A1  - Varlotta, A.
A1  - Vassiliev, V. V.
A1  - Vincent, S.
A1  - Wakely, S. P.
A1  - Ward, J. E.
A1  - Weinstein, A.
A1  - Welsing, R.
A1  - Wilhelm, Alina
T1  - Investigating the TeV morpholoy of MGRO J1908+06 with veritas
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - 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.
KW  - gamma rays: general
KW  - gamma-ray burst: individual (MGRO J1908+06, VER J1907+062)
KW  - pulsars: individual (PSR J1907+0602)
KW  - ISM: supernova remnants
Y1  - 2014
U6  - https://doi.org/10.1088/0004-637X/787/2/166
SN  - 0004-637X
SN  - 1538-4357
VL  - 787
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Abeysekara, A. U.
A1  - Archambault, S.
A1  - Archer, A.
A1  - Benbow, W.
A1  - Bird, R.
A1  - Buchovecky, M.
A1  - Buckley, J. H.
A1  - Byrum, K.
A1  - Cardenzana, J. V.
A1  - Cerruti, M.
A1  - Chen, Xuhui
A1  - Christiansen, J. L.
A1  - Ciupik, L.
A1  - Cui, W.
A1  - Dickinson, H. J.
A1  - Eisch, J. D.
A1  - Errando, M.
A1  - Falcone, A.
A1  - Fegan, D. J.
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Fleischhack, H.
A1  - Fortin, P.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Gillanders, G. H.
A1  - Griffin, S.
A1  - Grube, J.
A1  - Gyuk, G.
A1  - Huetten, M.
A1  - Hakansson, Nils
A1  - Hanna, D.
A1  - Holder, J.
A1  - Humensky, T. B.
A1  - Johnson, C. A.
A1  - Kaaret, P.
A1  - Kar, P.
A1  - Kelley-Hoskins, N.
A1  - Kertzman, M.
A1  - Kieda, D.
A1  - Krause, M.
A1  - Krennrich, F.
A1  - Kumar, S.
A1  - Lang, M. J.
A1  - Lin, T. T. Y.
A1  - Maier, G.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Meagher, K.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nieto, D.
A1  - Ong, R. A.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Perkins, J. S.
A1  - Petrashyk, A.
A1  - Pohl, Martin
A1  - Popkow, A.
A1  - Pueschel, Elisa
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Ratliff, G.
A1  - Reynolds, P. T.
A1  - Richards, G. T.
A1  - Roache, E.
A1  - Santander, M.
A1  - Sembroski, G. H.
A1  - Shahinyan, K.
A1  - Staszak, D.
A1  - Telezhinsky, Igor O.
A1  - Tucci, J. V.
A1  - Tyler, J.
A1  - Vincent, S.
A1  - Wakely, S. P.
A1  - Weiner, O. M.
A1  - Weinstein, A.
A1  - Williams, D. A.
A1  - Zitzer, B.
T1  - A SEARCH FOR BRIEF OPTICAL FLASHES ASSOCIATED WITH THE SETI TARGET KIC 8462852
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics ; Part 2, Letters
N2  - 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.
KW  - astrobiology
KW  - extraterrestrial intelligence
KW  - methods: observational
KW  - stars: individual ( KIC 8462852)
KW  - techniques: photometric
Y1  - 2016
U6  - https://doi.org/10.3847/2041-8205/818/2/L33
SN  - 2041-8205
SN  - 2041-8213
VL  - 818
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Aliu, E.
A1  - Archer, A.
A1  - Aune, T.
A1  - Barnacka, Anna
A1  - Behera, B.
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Berger, K.
A1  - Bird, R.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Byrum, K.
A1  - Cardenzana, J. V.
A1  - Cerruti, M.
A1  - Chen, Xuhui
A1  - Ciupik, L.
A1  - Connolly, M. P.
A1  - Cui, Wei
A1  - Dickinson, H. J.
A1  - Dumm, J.
A1  - Eisch, J. D.
A1  - Errando, M.
A1  - Falcone, A.
A1  - Federici, Simone
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Fortin, P.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Galante, N.
A1  - Gillanders, G. H.
A1  - Griffin, S.
A1  - Griffiths, S. T.
A1  - Grube, J.
A1  - Gyuk, G.
A1  - Hakansson, Nils
A1  - Hanna, D.
A1  - Holder, J.
A1  - Hughes, G.
A1  - Humensky, T. B.
A1  - Johnson, C. A.
A1  - Kaaret, P.
A1  - Kar, P.
A1  - Kertzman, M.
A1  - Khassen, Y.
A1  - Kieda, D.
A1  - Krawczynski, H.
A1  - Krennrich, F.
A1  - Kumar, S.
A1  - Lang, M. J.
A1  - Madhavan, A.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Meagher, K.
A1  - Millis, J.
A1  - Moriarty, P.
A1  - Nieto, Daniel
A1  - Ong, R. A.
A1  - Orr, M.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Perkins, J. S.
A1  - Pohl, Martin
A1  - Popkow, A.
A1  - Prokoph, H.
A1  - Pueschel, Elisa
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Rajotte, J.
A1  - Reyes, L. C.
A1  - Reynolds, P. T.
A1  - Richards, G. T.
A1  - Roache, E.
A1  - Sembroski, G. H.
A1  - Shahinyan, K.
A1  - Staszak, D.
A1  - Telezhinsky, Igor O.
A1  - Tucci, J. V.
A1  - Tyler, J.
A1  - Varlotta, A.
A1  - Vassiliev, V. V.
A1  - Wakely, S. P.
A1  - Weinstein, A.
A1  - Welsing, R.
A1  - Wilhelm, Alina
A1  - Williams, D. A.
A1  - Zitzer, B.
T1  - Veritas observations of the BL LAC OBJECT PG 1553+113
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - We present results from VERITAS observations of the BL Lac object PG 1553+113 spanning the years 2010, 2011, and 2012. The time-averaged spectrum, measured between 160 and 560 GeV, is well described by a power law with a spectral index of 4.33 +/- 0.09. The time-averaged integral flux above 200 GeV measured for this period was (1.69 +/- 0.06) x 10(-11) photons cm(-2) s(-1), corresponding to 6.9% of the Crab Nebula flux. We also present the combined gamma-ray spectrum from the Fermi Large Area Telescope and VERITAS covering an energy range from 100 MeV to 560 GeV. The data are well fit by a power law with an exponential cutoff at 101.9 +/- 3.2 GeV. The origin of the cutoff could be intrinsic to PG 1553+113 or be due to the gamma-ray opacity of our universe through pair production off the extragalactic background light (EBL). Given lower limits to the redshift of z > 0.395 based on optical/UV observations of PG 1553+113, the cutoff would be dominated by EBL absorption. Conversely, the small statistical uncertainties of the VERITAS energy spectrum have allowed us to provide a robust upper limit on the redshift of PG 1553+113 of z <= 0.62. A strongly elevated mean flux of (2.50 +/- 0.14) x10(-11) photons cm(-2) s(-1) (10.3% of the Crab Nebula flux) was observed during 2012, with the daily flux reaching as high as (4.44 +/- 0.71) x10(-11) photons cm(-2) s(-1) (18.3% of the Crab Nebula flux) on MJD 56048. The light curve measured during the 2012 observing season is marginally inconsistent with a steady flux, giving a chi(2) probability for a steady flux of 0.03%.
KW  - BL Lacertae objects: general
Y1  - 2015
U6  - https://doi.org/10.1088/0004-637X/799/1/7
SN  - 0004-637X
SN  - 1538-4357
VL  - 799
IS  - 1
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Archambault, S.
A1  - Archer, A.
A1  - Aune, T.
A1  - Barnacka, Anna
A1  - Benbow, W.
A1  - Bird, R.
A1  - Buchovecky, M.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Byrum, K.
A1  - Cardenzana, J. V.
A1  - Cerruti, M.
A1  - Chen, Xuhui
A1  - Ciupik, L.
A1  - Collins-Hughes, E.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Dickinson, H. J.
A1  - Dumm, J.
A1  - Eisch, J. D.
A1  - Falcone, A.
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Fleischhack, H.
A1  - Flinders, A.
A1  - Fortin, P.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Gillanders, G. H.
A1  - Griffin, S.
A1  - Grube, J.
A1  - Gyuk, G.
A1  - Huetten, M.
A1  - Hakansson, Nils
A1  - Hanna, D.
A1  - Holder, J.
A1  - Humensky, T. B.
A1  - Johnson, C. A.
A1  - Kaaret, P.
A1  - Kar, P.
A1  - Kelley-Hoskins, N.
A1  - Kertzman, M.
A1  - Khassen, Y.
A1  - Kieda, D.
A1  - Krause, M.
A1  - Krennrich, F.
A1  - Kumar, S.
A1  - Lang, M. J.
A1  - Maier, G.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Meagher, K.
A1  - Millis, J.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nieto, D.
A1  - Ong, R. A.
A1  - Otte, A. N.
A1  - Pandel, D.
A1  - Park, N.
A1  - Pelassa, V.
A1  - Pohl, Martin
A1  - Popkow, A.
A1  - Pueschel, Elisa
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reynolds, P. T.
A1  - Richards, G. T.
A1  - Roache, E.
A1  - Rousselle, J.
A1  - Rulten, C.
A1  - Santander, M.
A1  - Sembroski, G. H.
A1  - Shahinyan, K.
A1  - Smith, A. W.
A1  - Staszak, D.
A1  - Telezhinsky, Igor O.
A1  - Tucci, J. V.
A1  - Tyler, J.
A1  - Vincent, S.
A1  - Wakely, S. P.
A1  - Weiner, O. M.
A1  - Weinstein, A.
A1  - Wilhelm, Alina
A1  - Williams, D. A.
A1  - Zitzer, B.
T1  - EXCEPTIONALLY BRIGHT TEV FLARES FROM THE BINARY LS I+61 degrees 303
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics ; Part 2, Letters
N2  - The TeV binary system LS I +61 degrees 303 is known for its regular, non-thermal emission pattern that traces the orbital period of the compact object in its 26.5 day orbit around its B0 Ve star companion. The system typically presents elevated TeV emission around apastron passage with flux levels between 5% and 15% of the steady flux from the Crab Nebula (> 300 GeV). In this article, VERITAS observations of LS I + 61 degrees. 303 taken in late 2014 are presented, during which bright TeV flares around apastron at flux levels peaking above 30% of the Crab Nebula flux were detected. This is the brightest such activity from this source ever seen in the TeV regime. The strong outbursts have rise and fall times of less than a day. The short timescale of the flares, in conjunction with the observation of 10 TeV photons from LS I + 61 degrees 303 during the flares, provides constraints on the properties of the accelerator in the source.
KW  - binaries: general
KW  - gamma-rays: general
KW  - stars: individual (LS I+61 degrees 303, VER J0240+612)
KW  - X-rays: binaries
Y1  - 2016
U6  - https://doi.org/10.3847/2041-8205/817/1/L7
SN  - 2041-8205
SN  - 2041-8213
VL  - 817
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Abeysekara, A. U.
A1  - Archambault, S.
A1  - Archer, A.
A1  - Benbow, Wystan
A1  - Bird, Ralph
A1  - Buchovecky, M.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Byrum, K.
A1  - Cerruti, M.
A1  - Chen, X.
A1  - Ciupik, L.
A1  - Cui, W.
A1  - Dickinson, H. J.
A1  - Eisch, J. D.
A1  - Errando, M.
A1  - Falcone, A.
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Fleischhack, H.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Gillanders, G. H.
A1  - Griffin, S.
A1  - Grube, J.
A1  - Hutten, M.
A1  - Hakansson, N.
A1  - Hanna, D.
A1  - Holder, J.
A1  - Humensky, T. B.
A1  - Johnson, C. A.
A1  - Kaaret, P.
A1  - Kar, P.
A1  - Kertzman, M.
A1  - Kieda, D.
A1  - Krause, M.
A1  - Krennrich, F.
A1  - Kumar, S.
A1  - Lang, M. J.
A1  - Maier, G.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Meagher, K.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nguyen, T.
A1  - Nieto, D.
A1  - Ong, R. A.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Pelassa, V.
A1  - Pohl, Martin
A1  - Popkow, A.
A1  - Pueschel, Elisa
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reynolds, P. T.
A1  - Richards, G. T.
A1  - Roache, E.
A1  - Rulten, C.
A1  - Santander, M.
A1  - Sembroski, G. H.
A1  - Shahinyan, K.
A1  - Staszak, D.
A1  - Telezhinsky, Igor O.
A1  - Tucci, J. V.
A1  - Tyler, J.
A1  - Wakely, S. P.
A1  - Weiner, O. M.
A1  - Weinstein, A.
A1  - Wilhelm, Alina
A1  - Williams, D. A.
A1  - Fegan, S.
A1  - Giebels, B.
A1  - Horan, D.
A1  - Berdyugin, A.
A1  - Kuan, J.
A1  - Lindfors, E.
A1  - Nilsson, K.
A1  - Oksanen, A.
A1  - Prokoph, H.
A1  - Reinthal, R.
A1  - Takalo, L.
A1  - Zefi, F.
T1  - A Luminous and Isolated Gamma-Ray Flare from the Blazar B2 1215+30
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - B2 1215+30 is a BL-Lac-type blazar that was first detected at TeV energies by the MAGIC atmospheric Cherenkov telescopes and subsequently confirmed by the Very Energetic Radiation Imaging Telescope Array System (VERITAS) observatory with data collected between 2009 and 2012. In 2014 February 08, VERITAS detected a large-amplitude flare from B2. 1215+30 during routine monitoring observations of the blazar 1ES. 1218+304, located in the same field of view. The TeV flux reached 2.4 times the Crab Nebula flux with a variability timescale of <3.6 hr. Multiwavelength observations with Fermi-LAT, Swift, and the Tuorla Observatory revealed a correlated high GeV flux state and no significant optical counterpart to the flare, with a spectral energy distribution where the gamma-ray luminosity exceeds the synchrotron luminosity. When interpreted in the framework of a onezone leptonic model, the observed emission implies a high degree of beaming, with Doppler factor delta > 10, and an electron population with spectral index p < 2.3.
KW  - BL Lacertae objects: individual (B2 1215+30, VER J1217+301)
KW  - galaxies: active
KW  - galaxies: jets
KW  - galaxies: nuclei
KW  - gamma rays: galaxies
Y1  - 2017
U6  - https://doi.org/10.3847/1538-4357/836/2/205
SN  - 0004-637X
SN  - 1538-4357
VL  - 836
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Archambault, S.
A1  - Archer, A.
A1  - Benbow, Wystan
A1  - Bird, Ralph
A1  - Bourbeau, E.
A1  - Buchovecky, M.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Cerruti, M.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Dwarkadas, Vikram V.
A1  - Errando, M.
A1  - Falcone, A.
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Fleischhack, H.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Griffin, S.
A1  - Huetten, M.
A1  - Hanna, D.
A1  - Holder, J.
A1  - Johnson, C. A.
A1  - Kaaret, P.
A1  - Kar, P.
A1  - Kelley-Hoskins, N.
A1  - Kertzman, M.
A1  - Kieda, D.
A1  - Krause, M.
A1  - Kumar, S.
A1  - Lang, M. J.
A1  - Maier, G.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nieto, D.
A1  - Ong, R. A.
A1  - Otte, A. N.
A1  - Park, Nahee
A1  - Pohl, Martin
A1  - Popkow, A.
A1  - Pueschel, Elisa
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reynolds, P. T.
A1  - Richards, G. T.
A1  - Roache, E.
A1  - Sadeh, I.
A1  - Santander, M.
A1  - Sembroski, G. H.
A1  - Shahinyan, K.
A1  - Slane, P.
A1  - Staszak, D.
A1  - Telezhinsky, Igor O.
A1  - Trepanier, S.
A1  - Tyler, J.
A1  - Wakely, S. P.
A1  - Weinstein, A.
A1  - Weisgarber, T.
A1  - Wilcox, P.
A1  - Wilhelm, Alina
A1  - Williams, D. A.
A1  - Zitzer, B.
T1  - Gamma-ray Observations of Tycho's Supernova Remnant with VERITAS and Fermi
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
KW  - material
KW  - data behind figure
Y1  - 2017
U6  - https://doi.org/10.3847/1538-4357/836/1/23
SN  - 0004-637X
SN  - 1538-4357
VL  - 836
IS  - 1
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Middeldorp, Christel M.
A1  - Mahajan, Anubha
A1  - Horikoshi, Momoko
A1  - Robertson, Neil R.
A1  - Beaumont, Robin N.
A1  - Bradfield, Jonathan P.
A1  - Bustamante, Mariona
A1  - Cousminer, Diana L.
A1  - Day, Felix R.
A1  - De Silva, N. Maneka
A1  - Guxens, Monica
A1  - Mook-Kanamori, Dennis O.
A1  - St Pourcain, Beate
A1  - Warrington, Nicole M.
A1  - Adair, Linda S.
A1  - Ahlqvist, Emma
A1  - Ahluwalia, Tarunveer Singh
A1  - Almgren, Peter
A1  - Ang, Wei
A1  - Atalay, Mustafa
A1  - Auvinen, Juha
A1  - Bartels, Meike
A1  - Beckmann, Jacques S.
A1  - Bilbao, Jose Ramon
A1  - Bond, Tom
A1  - Borja, Judith B.
A1  - Cavadino, Alana
A1  - Charoen, Pimphen
A1  - Chen, Zhanghua
A1  - Coin, Lachlan
A1  - Cooper, Cyrus
A1  - Curtin, John A.
A1  - Custovic, Adnan
A1  - Das, Shikta
A1  - Davies, Gareth E.
A1  - Dedoussis, George V.
A1  - Duijts, Liesbeth
A1  - Eastwood, Peter R.
A1  - Eliasen, Anders U.
A1  - Elliott, Paul
A1  - Eriksson, Johan G.
A1  - Estivill, Xavier
A1  - Fadista, Joao
A1  - Fedko, Iryna O.
A1  - Frayling, Timothy M.
A1  - Gaillard, Romy
A1  - Gauderman, W. James
A1  - Geller, Frank
A1  - Gilliland, Frank
A1  - Gilsanz, Vincente
A1  - Granell, Raquel
A1  - Grarup, Niels
A1  - Groop, Leif
A1  - Hadley, Dexter
A1  - Hakonarson, Hakon
A1  - Hansen, Torben
A1  - Hartman, Catharina A.
A1  - Hattersley, Andrew T.
A1  - Hayes, M. Geoffrey
A1  - Hebebrand, Johannes
A1  - Heinrich, Joachim
A1  - Helgeland, Oyvind
A1  - Henders, Anjali K.
A1  - Henderson, John
A1  - Henriksen, Tine B.
A1  - Hirschhorn, Joel N.
A1  - Hivert, Marie-France
A1  - Hocher, Berthold
A1  - Holloway, John W.
A1  - Holt, Patrick
A1  - Hottenga, Jouke-Jan
A1  - Hypponen, Elina
A1  - Iniguez, Carmen
A1  - Johansson, Stefan
A1  - Jugessur, Astanand
A1  - Kahonen, Mika
A1  - Kalkwarf, Heidi J.
A1  - Kaprio, Jaakko
A1  - Karhunen, Ville
A1  - Kemp, John P.
A1  - Kerkhof, Marjan
A1  - Koppelman, Gerard H.
A1  - Korner, Antje
A1  - Kotecha, Sailesh
A1  - Kreiner-Moller, Eskil
A1  - Kulohoma, Benard
A1  - Kumar, Ashish
A1  - Kutalik, Zoltan
A1  - Lahti, Jari
A1  - Lappe, Joan M.
A1  - Larsson, Henrik
A1  - Lehtimaki, Terho
A1  - Lewin, Alexandra M.
A1  - Li, Jin
A1  - Lichtenstein, Paul
A1  - Lindgren, Cecilia M.
A1  - Lindi, Virpi
A1  - Linneberg, Allan
A1  - Liu, Xueping
A1  - Liu, Jun
A1  - Lowe, William L.
A1  - Lundstrom, Sebastian
A1  - Lyytikainen, Leo-Pekka
A1  - Ma, Ronald C. W.
A1  - Mace, Aurelien
A1  - Magi, Reedik
A1  - Magnus, Per
A1  - Mamun, Abdullah A.
A1  - Mannikko, Minna
A1  - Martin, Nicholas G.
A1  - Mbarek, Hamdi
A1  - McCarthy, Nina S.
A1  - Medland, Sarah E.
A1  - Melbye, Mads
A1  - Melen, Erik
A1  - Mohlke, Karen L.
A1  - Monnereau, Claire
A1  - Morgen, Camilla S.
A1  - Morris, Andrew P.
A1  - Murray, Jeffrey C.
A1  - Myhre, Ronny
A1  - Najman, Jackob M.
A1  - Nivard, Michel G.
A1  - Nohr, Ellen A.
A1  - Nolte, Ilja M.
A1  - Ntalla, Ioanna
A1  - Oberfield, Sharon E.
A1  - Oken, Emily
A1  - Oldehinkel, Albertine J.
A1  - Pahkala, Katja
A1  - Palviainen, Teemu
A1  - Panoutsopoulou, Kalliope
A1  - Pedersen, Oluf
A1  - Pennell, Craig E.
A1  - Pershagen, Goran
A1  - Pitkanen, Niina
A1  - Plomin, Robert
A1  - Power, Christine
A1  - Prasad, Rashmi B.
A1  - Prokopenko, Inga
A1  - Pulkkinen, Lea
A1  - Raikkonen, Katri
A1  - Raitakari, Olli T.
A1  - Reynolds, Rebecca M.
A1  - Richmond, Rebecca C.
A1  - Rivadeneira, Fernando
A1  - Rodriguez, Alina
A1  - Rose, Richard J.
A1  - Salem, Rany
A1  - Santa-Marina, Loreto
A1  - Saw, Seang-Mei
A1  - Schnurr, Theresia M.
A1  - Scott, James G.
A1  - Selzam, Saskia
A1  - Shepherd, John A.
A1  - Simpson, Angela
A1  - Skotte, Line
A1  - Sleiman, Patrick M. A.
A1  - Snieder, Harold
A1  - Sorensen, Thorkild I. A.
A1  - Standl, Marie
A1  - Steegers, Eric A. P.
A1  - Strachan, David P.
A1  - Straker, Leon
A1  - Strandberg, Timo
A1  - Taylor, Michelle
A1  - Teo, Yik-Ying
A1  - Thiering, Elisabeth
A1  - Torrent, Maties
A1  - Tyrrell, Jessica
A1  - Uitterlinden, Andre G.
A1  - van Beijsterveldt, Toos
A1  - van der Most, Peter J.
A1  - van Duijn, Cornelia M.
A1  - Viikari, Jorma
A1  - Vilor-Tejedor, Natalia
A1  - Vogelezang, Suzanne
A1  - Vonk, Judith M.
A1  - Vrijkotte, Tanja G. M.
A1  - Vuoksimaa, Eero
A1  - Wang, Carol A.
A1  - Watkins, William J.
A1  - Wichmann, H-Erich
A1  - Willemsen, Gonneke
A1  - Williams, Gail M.
A1  - Wilson, James F.
A1  - Wray, Naomi R.
A1  - Xu, Shujing
A1  - Xu, Cheng-Jian
A1  - Yaghootkar, Hanieh
A1  - Yi, Lu
A1  - Zafarmand, Mohammad Hadi
A1  - Zeggini, Eleftheria
A1  - Zemel, Babette S.
A1  - Hinney, Anke
A1  - Lakka, Timo A.
A1  - Whitehouse, Andrew J. O.
A1  - Sunyer, Jordi
A1  - Widen, Elisabeth E.
A1  - Feenstra, Bjarke
A1  - Sebert, Sylvain
A1  - Jacobsson, Bo
A1  - Njolstad, Pal R.
A1  - Stoltenberg, Camilla
A1  - Smith, George Davey
A1  - Lawlor, Debbie A.
A1  - Paternoster, Lavinia
A1  - Timpson, Nicholas J.
A1  - Ong, Ken K.
A1  - Bisgaard, Hans
A1  - Bonnelykke, Klaus
A1  - Jaddoe, Vincent W. V.
A1  - Tiemeier, Henning
A1  - Jarvelin, Marjo-Riitta
A1  - Evans, David M.
A1  - Perry, John R. B.
A1  - Grant, Struan F. A.
A1  - Boomsma, Dorret I.
A1  - Freathy, Rachel M.
A1  - McCarthy, Mark I.
A1  - Felix, Janine F.
T1  - The Early Growth Genetics (EGG) and EArly Genetics and Lifecourse Epidemiology (EAGLE) consortia
BT  - design, results and future prospects
JF  - European journal of epidemiology
N2  - The impact of many unfavorable childhood traits or diseases, such as low birth weight and mental disorders, is not limited to childhood and adolescence, as they are also associated with poor outcomes in adulthood, such as cardiovascular disease. Insight into the genetic etiology of childhood and adolescent traits and disorders may therefore provide new perspectives, not only on how to improve wellbeing during childhood, but also how to prevent later adverse outcomes. To achieve the sample sizes required for genetic research, the Early Growth Genetics (EGG) and EArly Genetics and Lifecourse Epidemiology (EAGLE) consortia were established. The majority of the participating cohorts are longitudinal population-based samples, but other cohorts with data on early childhood phenotypes are also involved. Cohorts often have a broad focus and collect(ed) data on various somatic and psychiatric traits as well as environmental factors. Genetic variants have been successfully identified for multiple traits, for example, birth weight, atopic dermatitis, childhood BMI, allergic sensitization, and pubertal growth. Furthermore, the results have shown that genetic factors also partly underlie the association with adult traits. As sample sizes are still increasing, it is expected that future analyses will identify additional variants. This, in combination with the development of innovative statistical methods, will provide detailed insight on the mechanisms underlying the transition from childhood to adult disorders. Both consortia welcome new collaborations. Policies and contact details are available from the corresponding authors of this manuscript and/or the consortium websites.
KW  - Genetics
KW  - Consortium
KW  - Childhood traits and disorders
KW  - Longitudinal
Y1  - 2019
U6  - https://doi.org/10.1007/s10654-019-00502-9
SN  - 0393-2990
SN  - 1573-7284
VL  - 34
IS  - 3
SP  - 279
EP  - 300
PB  - Springer
CY  - Dordrecht
ER  - 
TY  - JOUR
A1  - Allen, C.
A1  - Archambault, S.
A1  - Archer, A.
A1  - Benbow, W.
A1  - Bird, R.
A1  - Bourbeau, E.
A1  - Brose, Robert
A1  - Buchovecky, M.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Cardenzana, J. V.
A1  - Cerruti, M.
A1  - Chen, Xuhui
A1  - Christiansen, J. L.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Daniel, M. K.
A1  - Eisch, J. D.
A1  - Falcone, Abe
A1  - Feng, Q.
A1  - Fernandez-Alonso, M.
A1  - Finley, J. P.
A1  - Fleischhack, H.
A1  - Flinders, A.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Gillanders, G. H.
A1  - Griffin, S.
A1  - Grube, J.
A1  - Huetten, M.
A1  - Hakansson, N.
A1  - Hanna, D.
A1  - Hervet, O.
A1  - Holder, J.
A1  - Hughes, G.
A1  - Humensky, T. B.
A1  - Johnson, C. A.
A1  - Kaaret, P.
A1  - Kar, P.
A1  - Kelley-Hoskins, N.
A1  - Kertzman, M.
A1  - Kieda, D.
A1  - Krause, M.
A1  - Krennrich, F.
A1  - Kumar, S.
A1  - Lang, M. J.
A1  - Maier, G.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Meagher, K.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nguyen, T.
A1  - Nieto, D.
A1  - Ong, R. A.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Petrashyk, A.
A1  - Pichel, A.
A1  - Pohl, Martin
A1  - Popkow, A.
A1  - Pueschel, Elisa
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reynolds, P. T.
A1  - Richards, G. T.
A1  - Roache, E.
A1  - Rovero, A. C.
A1  - Rulten, C.
A1  - Sadeh, I.
A1  - Santander, Marcos
A1  - Sembroski, G. H.
A1  - Shahinyan, K.
A1  - Telezhinsky, Igor O.
A1  - Tucci, J. V.
A1  - Tyler, J.
A1  - Wakely, S. P.
A1  - Weinstein, A.
A1  - Wilhelm, Alina
A1  - Williams, D. A.
T1  - Very-High-Energy gamma-Ray Observations of the Blazar 1ES 2344+514 with VERITAS
JF  - Monthly notices of the Royal Astronomical Society
N2  - We present very-high-energy gamma-ray observations of the BL Lac object 1ES 2344+514 taken by the Very Energetic Radiation Imaging Telescope Array System between 2007 and 2015. 1ES 2344+514 is detected with a statistical significance above the background of 20.8 sigma in 47.2 h (livetime) of observations, making this the most comprehensive very-high-energy study of 1ES 2344+514 to date. Using these observations, the temporal properties of 1ES 2344+514 are studied on short and long times-scales. We fit a constant-flux model to nightly and seasonally binned light curves and apply a fractional variability test to determine the stability of the source on different time-scales. We reject the constant-flux model for the 2007-2008 and 2014-2015 nightly binned light curves and for the long-term seasonally binned light curve at the > 3 sigma level. The spectra of the time-averaged emission before and after correction for attenuation by the extragalactic background light are obtained. The observed time-averaged spectrum above 200 GeV is satisfactorily fitted (x(2)/NDF = 7.89/6) by a power-law function with an index Gamma = 2.46 +/- 0.06(stat) +/- 0.20(sys) and extends to at least 8 TeV. The extragalactic-backgroundlight-deabsorbed spectrum is adequately fit (x(2)/NDF = 6.73/6) by a power-law function with an index Gamma = 2.15 +/- 0.06(stat) +/- 0.20(sys) while an F-test indicates that the power law with an exponential cut-off function provides a marginally better fit (x(2)/NDF = 2.56/5) at the 2.1 sigma level. The source location is found to be consistent with the published radio location and its spatial extent is consistent with a point source.
KW  - astroparticle physics
KW  - BL Lacertae objects: individual: 1ES 2344+514=VERJ2347+517
KW  - gamma-rays: galaxies
Y1  - 2017
U6  - https://doi.org/10.1093/mnras/stx1756
SN  - 0035-8711
SN  - 1365-2966
VL  - 471
SP  - 2117
EP  - 2123
PB  - Oxford Univ. Press
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Abeysekara, A. U.
A1  - Archambault, S.
A1  - Archer, A.
A1  - Benbow, W.
A1  - Bird, R.
A1  - Brose, Robert
A1  - Buchovecky, M.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Cerruti, M.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Falcone, A.
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Fleischhack, H.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Gillanders, G. H.
A1  - Griffin, S.
A1  - Grube, J.
A1  - Huetten, M.
A1  - Hanna, D.
A1  - Hervet, O.
A1  - Holder, J.
A1  - Humensky, T. B.
A1  - Johnson, C. A.
A1  - Kaaret, P.
A1  - Kar, P.
A1  - Kelley-Hoskins, N.
A1  - Kertzman, M.
A1  - Kieda, D.
A1  - Krause, M.
A1  - Krennrich, F.
A1  - Kumar, S.
A1  - Lang, M. J.
A1  - Maier, G.
A1  - McArthur, S.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nieto, D.
A1  - Ong, R. A.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Petrashyk, A.
A1  - Pohl, Martin
A1  - Popkow, A.
A1  - Pueschel, Elisa
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reynolds, P. T.
A1  - Richards, G. T.
A1  - Roache, E.
A1  - Rulten, C.
A1  - Sadeh, I.
A1  - Santander, M.
A1  - Sembroski, G. H.
A1  - Shahinyan, K.
A1  - Staszak, D.
A1  - Telezhinsky, Igor O.
A1  - Tyler, J.
A1  - Vassiliev, V. V.
A1  - Wakely, S. P.
A1  - Weiner, O. M.
A1  - Weinstein, A.
A1  - Wilcox, P.
A1  - Wilhelm, Alina
A1  - Williams, D. A.
A1  - Zitzer, B.
T1  - Discovery of Very-high-energy Emission from RGB J2243+203 and Derivation of Its Redshift Upper Limit
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics ; Supplement series
N2  - 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.
KW  - galaxies: individual (RGB J2243+203)
Y1  - 2017
U6  - https://doi.org/10.3847/1538-4365/aa8d76
SN  - 0067-0049
SN  - 1538-4365
VL  - 233
SP  - 1188
EP  - 1204
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Orienti, M.
A1  - Finke, J.
A1  - Raiteri, C. M.
A1  - Hovatta, T.
A1  - Larsson, J.
A1  - Max-Moerbeck, W.
A1  - Perkins, J.
A1  - Readhead, A. C. S.
A1  - Richards, J. L.
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Berger, K.
A1  - Bird, R.
A1  - Bugaev, V.
A1  - Cardenzana, J. V.
A1  - Cerruti, M.
A1  - Chen, Xuhui
A1  - Ciupik, L.
A1  - Dickinson, H. J.
A1  - Eisch, J. D.
A1  - Errando, M.
A1  - Falcone, A.
A1  - Finley, J. P.
A1  - Fleischhack, H.
A1  - Fortin, P.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Gerard, L.
A1  - Gillanders, G. H.
A1  - Griffiths, S. T.
A1  - Grube, J.
A1  - Gyuk, G.
A1  - Hakansson, Nils
A1  - Holder, J.
A1  - Humensky, T. B.
A1  - Kar, P.
A1  - Kertzman, M.
A1  - Khassen, Y.
A1  - Kieda, D.
A1  - Krennrich, F.
A1  - Kumar, S.
A1  - Lang, M. J.
A1  - Maier, G.
A1  - McCann, A.
A1  - Meagher, K.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nieto, D.
A1  - Ong, R. A.
A1  - Otte, A. N.
A1  - Pohl, Manuela
A1  - Popkow, A.
A1  - Prokoph, H.
A1  - Pueschel, Elisa
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reynolds, P. T.
A1  - Richards, G. T.
A1  - Roache, E.
A1  - Rousselle, J.
A1  - Santander, M.
A1  - Sembroski, G. H.
A1  - Smith, A. W.
A1  - Staszak, D.
A1  - Telezhinsky, Igor O.
A1  - Tucci, J. V.
A1  - Tyler, J.
A1  - Varlotta, A.
A1  - Vassiliev, V. V.
A1  - Wakely, S. P.
A1  - Weinstein, A.
A1  - Welsing, R.
A1  - Williams, D. A.
A1  - Zitzer, B.
T1  - The most powerful flaring activity from the NLSyl PMN J0948+0022
JF  - Monthly notices of the Royal Astronomical Society
N2  - 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.
KW  - galaxies: active-galaxies: individual: PMN J0948+0022
KW  - galaxies: nuclei
KW  - galaxies: Seyfert
KW  - gamma-rays: general
Y1  - 2015
U6  - https://doi.org/10.1093/mnras/stu2251
SN  - 0035-8711
SN  - 1365-2966
VL  - 446
IS  - 3
SP  - 2456
EP  - 2467
PB  - Oxford Univ. Press
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Archer, A.
A1  - Benbow, W.
A1  - Bird, R.
A1  - Buchovecky, M.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Byrum, K.
A1  - Cardenzana, J. V.
A1  - Cerruti, M.
A1  - Chen, Xuhui
A1  - Ciupik, L.
A1  - Collins-Hughes, E.
A1  - Connolly, M. P.
A1  - Eisch, J. D.
A1  - Falcone, A.
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Fleischhack, H.
A1  - Flinders, A.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Gillanders, G. H.
A1  - Griffin, S.
A1  - Grube, J.
A1  - Gyuk, G.
A1  - Hakansson, Nils
A1  - Hanna, D.
A1  - Holder, J.
A1  - Humensky, T. B.
A1  - Huetten, M.
A1  - Johnson, C. A.
A1  - Kaaret, P.
A1  - Kar, P.
A1  - Kelley-Hoskins, N.
A1  - Kertzman, M.
A1  - Kieda, D.
A1  - Krause, M.
A1  - Krennrich, F.
A1  - Kumar, S.
A1  - Lang, M. J.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Meagher, K.
A1  - Millis, J.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nieto, D.
A1  - Ong, R. A.
A1  - Park, N.
A1  - Pelassa, V.
A1  - Pohl, Martin
A1  - Popkow, A.
A1  - Pueschel, Elisa
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Ratliff, G.
A1  - Reynolds, P. T.
A1  - Richards, G. T.
A1  - Roache, E.
A1  - Rousselle, J.
A1  - Santander, M.
A1  - Sembroski, G. H.
A1  - Shahinyan, K.
A1  - Smith, A. W.
A1  - Staszak, D.
A1  - Telezhinsky, Igor O.
A1  - Tucci, J. V.
A1  - Tyler, J.
A1  - Vassiliev, V. V.
A1  - Wakely, S. P.
A1  - Weiner, O. M.
A1  - Weinstein, A.
A1  - Wilhelm, Alina
A1  - Williams, D. A.
A1  - Zitzer, B.
A1  - Yusef-Zadeh, F.
T1  - TEV GAMMA-RAY OBSERVATIONS OF THE GALACTIC CENTER RIDGE BY VERITAS
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - The Galactic Center ridge has been observed extensively in the past by both GeV and TeV gamma-ray instruments revealing a wealth of structure, including a diffuse component and the point sources G0.9+0.1 (a composite supernova remnant) and Sgr A* (believed to be associated with the supermassive black hole located at the center of our Galaxy). Previous very high energy (VHE) gamma-ray observations with the H.E.S.S.. experiment have also detected an extended TeV gamma-ray component along the Galactic plane in the >300 GeV gamma-ray regime. Here we report on observations of the Galactic Center ridge from 2010 to 2014 by the VERITAS telescope array in the >2 TeV energy range. From these observations we (1) provide improved measurements of the differential energy spectrum for Sgr A* in the >2 TeV gamma-ray regime, (2) provide a detection in the >2 TeV gamma-ray emission from the composite SNR G0.9+0.1 and an improved determination of its multi-TeV gamma-ray energy spectrum, and. (3) report on the detection of VER J1746-289, a localized enhancement of >2 TeV gamma-ray emission along the Galactic plane.
KW  - Galaxy: center
KW  - gamma rays: general
KW  - supernovae: individual (G0.9+0.1)
Y1  - 2016
U6  - https://doi.org/10.3847/0004-637X/821/2/129
SN  - 0004-637X
SN  - 1538-4357
VL  - 821
SP  - 162
EP  - 167
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Archer, A.
A1  - Benbow, Wystan
A1  - Bird, Ralph
A1  - Brose, Robert
A1  - Buchovecky, M.
A1  - Buckley, J. H.
A1  - Chromey, A. J.
A1  - Cui, Wei
A1  - Falcone, A.
A1  - Feng, Qi
A1  - Finley, J. P.
A1  - Fortson, Lucy
A1  - Furniss, Amy
A1  - Gent, A.
A1  - Gueta, O.
A1  - Hanna, David
A1  - Hassan, T.
A1  - Hervet, Olivier
A1  - Holder, J.
A1  - Hughes, G.
A1  - Humensky, T. B.
A1  - Johnson, Caitlin A.
A1  - Kaaret, Philip
A1  - Kar, P.
A1  - Kelley-Hoskins, N.
A1  - Kertzman, M.
A1  - Kieda, David
A1  - Krennrich, F.
A1  - Kumar, S.
A1  - Lang, M. J.
A1  - Lin, T. T. Y.
A1  - McCann, A.
A1  - Moriarty, P.
A1  - Mukherjee, Reshmi
A1  - Ong, R. A.
A1  - Otte, Adam Nepomuk
A1  - Pandel, D.
A1  - Park, N.
A1  - Petrashyk, A.
A1  - Pohl, Martin
A1  - Pueschel, Elisa
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Richards, Gregory T.
A1  - Roache, E.
A1  - Sadeh, I
A1  - Santander, Marcos
A1  - Scott, S. S.
A1  - Sembroski, G. H.
A1  - Shahinyan, Karlen
A1  - Sushch, Iurii
A1  - Tyler, J.
A1  - Wakely, S. P.
A1  - Weinstein, A.
A1  - Wells, R. M.
A1  - Wilcox, P.
A1  - Wilhelm, Alina
A1  - Williams, D. A.
A1  - Williamson, T. J.
A1  - Zitzer, B.
T1  - A Search for Pulsed Very High-energy Gamma-Rays from 13 Young Pulsars in Archival VERITAS Data
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - We conduct a search for periodic emission in the very high-energy (VHE) gamma-ray band (E > 100 GeV) from a total of 13 pulsars in an archival VERITAS data set with a total exposure of over 450 hr. The set of pulsars includes many of the brightest young gamma-ray pulsars visible in the Northern Hemisphere. The data analysis resulted in nondetections of pulsed VHE gamma-rays from each pulsar. Upper limits on a potential VHE gamma-ray flux are derived at the 95% confidence level above three energy thresholds using two methods. These are the first such searches for pulsed VHE emission from each of the pulsars, and the obtained limits constrain a possible flux component manifesting at VHEs as is seen for the Crab pulsar.
KW  - gamma rays: general
KW  - pulsars: general
KW  - stars: neutron
Y1  - 2019
U6  - https://doi.org/10.3847/1538-4357/ab14f4
SN  - 0004-637X
SN  - 1538-4357
VL  - 876
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Archer, A.
A1  - Benbow, W.
A1  - Bird, R.
A1  - Brose, Robert
A1  - Buchovecky, M.
A1  - Bugaev, V.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Daniel, M. K.
A1  - Falcone, A.
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Fleischhack, H.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Hanna, D.
A1  - Hervet, O.
A1  - Holder, J.
A1  - Hughes, G.
A1  - Humensky, T. B.
A1  - Hutten, M.
A1  - Johnson, C. A.
A1  - Kaaret, P.
A1  - Kelley-Hoskins, N.
A1  - Kieda, D.
A1  - Krause, M.
A1  - Krennrich, F.
A1  - Kumar, S.
A1  - Lang, M. J.
A1  - Maier, G.
A1  - McArthur, S.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nieto, D.
A1  - Ong, R. A.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Petrashyk, A.
A1  - Pohl, Martin
A1  - Popkow, A.
A1  - Pueschel, Elisa
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reynolds, P. T.
A1  - Richards, G. T.
A1  - Roache, E.
A1  - Rulten, C.
A1  - Sadeh, I.
A1  - Tyler, J.
A1  - Wakely, S. P.
A1  - Weiner, O. M.
A1  - Wilcox, P.
A1  - Wilhelm, Alina
A1  - Williams, D. A.
A1  - Wissel, S. A.
A1  - Zitzer, B.
T1  - Measurement of the iron spectrum in cosmic rays by VERITAS
JF  - Physical review : D, Particles, fields, gravitation, and cosmology
N2  - We present a new measurement of the energy spectrum of iron nuclei in cosmic rays from 20 TeV to 500 TeV; The measurement makes use of a template-based analysis method, which, for the first time, is applied to the energy reconstruction of iron-induced air showers recorded by the VERITAS array of imaging atmospheric Cherenkov telescopes. The event selection makes use of the direct Cherenkov light which is emitted by charged particles before the first interaction, as well as other parameters related to the shape of the recorded air shower images. The measured spectrum is well described by a power law dF/dE = f(0) center dot (E/E-0)(-gamma) over the full energy range, with gamma = 2.82 +/- 0.30(stat)(-0.27)(+0.24)(syst) and f(0) = (4.82 +/- 0.98(stat)(-2.70)(+2.12)(syst)) x 10(-7) m(-2) s(-1) TeV-1 sr(-1) at E-0 = 50 TeV, with no indication of a cutoff or spectral break. The measured differential flux is compatible with previous results, with improved statistical uncertainty at the highest energies.
Y1  - 2018
U6  - https://doi.org/10.1103/PhysRevD.98.022009
SN  - 2470-0010
SN  - 2470-0029
VL  - 98
IS  - 2
PB  - American Physical Society
CY  - College Park
ER  - 
TY  - JOUR
A1  - Archer, A.
A1  - Benbow, W.
A1  - Bird, R.
A1  - Brose, Robert
A1  - Buchovecky, M.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Daniel, M. K.
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Gillanders, G.
A1  - Huetten, M.
A1  - Hanna, D.
A1  - Hervet, O.
A1  - Holder, J.
A1  - Hughes, G.
A1  - Humensky, T. B.
A1  - Johnson, C. A.
A1  - Kaaret, P.
A1  - Kar, P.
A1  - Kelley-Hoskins, N.
A1  - Kertzman, M.
A1  - Kieda, D.
A1  - Krause, M.
A1  - Krennrich, F.
A1  - Kumar, S.
A1  - Lang, M. J.
A1  - Lin, T. T. Y.
A1  - Maier, G.
A1  - McArthur, S.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Ong, R. A.
A1  - Otte, A. N.
A1  - Petrashyk, A.
A1  - Pohl, M.
A1  - Pueschel, Elisa
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reynolds, P. T.
A1  - Richards, G. T.
A1  - Roache, E.
A1  - Rulten, C.
A1  - Sadeh, I.
A1  - Santander, M.
A1  - Sembroski, G. H.
A1  - Staszak, D.
A1  - Sushch, I.
A1  - Wakely, S. P.
A1  - Wells, R. M.
A1  - Wilcox, P.
A1  - Wilhelm, Alina
A1  - Williams, D. A.
A1  - Williamson, T. J.
A1  - Zitzer, B.
T1  - Measurement of cosmic-ray electrons at TeV energies by VERITAS
JF  - Physical review : D, Particles, fields, gravitation, and cosmology
N2  - Cosmic-ray electrons and positrons (CREs) at GeV-TeV energies are a unique probe of our local Galactic neighborhood. CREs lose energy rapidly via synchrotron radiation and inverse-Compton scattering processes while propagating within the Galaxy, and these losses limit their propagation distance. For electrons with TeV energies, the limit is on the order of a kiloparsec. Within that distance, there are only a few known astrophysical objects capable of accelerating electrons to such high energies. It is also possible that the CREs are the products of the annihilation or decay of heavy dark matter (DM) particles. VERITAS, an array of imaging air Cherenkov telescopes in southern Arizona, is primarily utilized for gamma-ray astronomy but also simultaneously collects CREs during all observations. We describe our methods of identifying CREs in VERITAS data and present an energy spectrum, extending from 300 GeV to 5 TeV, obtained from approximately 300 hours of observations. A single power-law fit is ruled out in VERITAS data. We find that the spectrum of CREs is consistent with a broken power law, with a break energy at 710 +/- 40(stat) +/- 140(syst) GeV.
Y1  - 2018
U6  - https://doi.org/10.1103/PhysRevD.98.062004
SN  - 2470-0010
SN  - 2470-0029
VL  - 98
IS  - 6
PB  - American Physical Society
CY  - College Park
ER  - 
TY  - JOUR
A1  - Abeysekara, A. U.
A1  - Archer, A.
A1  - Aune, Taylor
A1  - Benbow, Wystan
A1  - Bird, Ralph
A1  - Brose, Robert
A1  - Buchovecky, M.
A1  - Bugaev, V.
A1  - Cui, Wei
A1  - Daniel, M. K.
A1  - Falcone, A.
A1  - Feng, Qi
A1  - Finley, John P.
A1  - Fleischhack, H.
A1  - Flinders, A.
A1  - Fortson, L.
A1  - Furniss, Amy
A1  - Gotthelf, Eric V.
A1  - Grube, J.
A1  - Hanna, David
A1  - Hervet, O.
A1  - Holder, J.
A1  - Huang, K.
A1  - Hughes, G.
A1  - Humensky, T. B.
A1  - Huetten, M.
A1  - Johnson, Caitlin A.
A1  - Kaaret, Philip
A1  - Kar, P.
A1  - Kelley-Hoskins, N.
A1  - Kertzman, M.
A1  - Kieda, David
A1  - Krause, Maria
A1  - Kumar, S.
A1  - Lang, M. J.
A1  - Lin, T. T. Y.
A1  - Maier, Gernot
A1  - McArthur, S.
A1  - Moriarty, P.
A1  - Mukherjee, Reshmi
A1  - Ong, R. A.
A1  - Otte, Adam Nepomuk
A1  - Pandel, Dirk
A1  - Park, Nahee
A1  - Petrashyk, A.
A1  - Pohl, Martin
A1  - Popkow, Alexis
A1  - Pueschel, Elisa
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reynolds, P. T.
A1  - Richards, Gregory T.
A1  - Roache, E.
A1  - Rousselle, J.
A1  - Rulten, C.
A1  - Sadeh, I.
A1  - Santander, M.
A1  - Sembroski, G. H.
A1  - Shahinyan, Karlen
A1  - Tyler, J.
A1  - Vassiliev, V. V.
A1  - Wakely, S. P.
A1  - Ward, J. E.
A1  - Weinstein, A.
A1  - Wells, R. M.
A1  - Wilcox, P.
A1  - Wilhelm, Alina
A1  - Williams, David A.
A1  - Zitzer, B.
T1  - A Very High Energy gamma-Ray Survey toward the Cygnus Region of the Galaxy
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - 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.
KW  - acceleration of particles
KW  - cosmic rays
KW  - gamma rays: general
KW  - ISM: supernova remnants
Y1  - 2018
U6  - https://doi.org/10.3847/1538-4357/aac4a2
SN  - 0004-637X
SN  - 1538-4357
VL  - 861
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Archer, A.
A1  - Benbow, Wystan
A1  - Bird, Ralph
A1  - Brose, Robert
A1  - Buchovecky, M.
A1  - Bugaev, V
A1  - Cui, Wei
A1  - Danie, M. K.
A1  - Falcone, A.
A1  - Feng, Qi
A1  - Finley, John P.
A1  - Flinders, A.
A1  - Fortson, L.
A1  - Furniss, Amy
A1  - Gillanders, Gerard H.
A1  - Huttens, M.
A1  - Hanna, David
A1  - Hervet, O.
A1  - Holder, J.
A1  - Hughes, G.
A1  - Humensky, T. B.
A1  - Johnson, Caitlin A.
A1  - Kaaret, Philip
A1  - Kar, P.
A1  - Kelley-Hoskins, N.
A1  - Kieda, David
A1  - Krause, Maria
A1  - Krennrich, F.
A1  - Kumar, S.
A1  - Lang, M. J.
A1  - Lin, T. T. Y.
A1  - McArthur, S.
A1  - Moriarty, P.
A1  - Mukherjee, Reshmi
A1  - Nieto, Daniel
A1  - Ong, R. A.
A1  - Otte, A. N.
A1  - Park, Nahee
A1  - Petrashyk, A.
A1  - Pohl, Martin
A1  - Popkow, Alexis
A1  - Pueschel, Elisa
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reynold, P. T.
A1  - Richards, Gregory T.
A1  - Roache, E.
A1  - Rulten, C.
A1  - Sadeh, I
A1  - Sembroski, G. H.
A1  - Shahinyan, Karlen
A1  - Tyler, J.
A1  - Wakely, S. P.
A1  - Weiner, O. M.
A1  - Weinstein, A.
A1  - Wells, R. M.
A1  - Wilcox, P.
A1  - Wilhelm, Alina
A1  - Williams, David A.
A1  - Brisken, W. F.
A1  - Pontrelli, P.
T1  - HESS J1943+213
BT  - An extreme blazar shining through the galactic plane
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - HESS J1943+213 is a very high energy (VHE; > 100 GeV) gamma-ray source in the direction of the Galactic plane. Studies exploring the classification of the source are converging toward its identification as an extreme synchrotron BL Lac object. Here we present 38 hr of VERITAS observations of HESS J1943+213 taken over 2 yr. The source is detected with a significance of similar to 20 standard deviations, showing a remarkably stable flux and spectrum in VHE gamma-rays. Multifrequency Very Long Baseline Array (VLBA) observations of the source confirm the extended, jet-like structure previously found in the 1.6 GHz band with the European VLBI Network and detect this component in the 4.6 and 7.3 GHz bands. The radio spectral indices of the core and the jet and the level of polarization derived from the VLBA observations are in a range typical for blazars. Data from VERITAS, Fermi-LAT, Swift-XRT, the FLWO 48 ' telescope, and archival infrared and hard X-ray observations are used to construct and model the spectral energy distribution (SED) of the source with a synchrotron self-Compton model. The well-measured gamma-ray peak of the SED with VERITAS and Fermi-LAT provides constraining upper limits on the source redshift. Possible contribution of secondary gamma-rays from ultra-high-energy cosmic-ray-initiated electromagnetic cascades to the gamma-ray emission is explored, finding that only a segment of the VHE spectrum can be accommodated with this process. A variability search is performed across X-ray and gamma-ray bands. No statistically significant flux or spectral variability is detected.
KW  - astroparticle physics
KW  - BL Lacertae objects: individual (HESS J1943+213, VER J1943+213)
KW  - galaxies: active
KW  - galaxies: jets
KW  - galaxies: nuclei
KW  - gamma rays: galaxies
Y1  - 2018
U6  - https://doi.org/10.3847/1538-4357/aacbd0
SN  - 0004-637X
SN  - 1538-4357
VL  - 862
IS  - 1
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Venkatraman, S.
A1  - Kumar, R.
A1  - Sankar, J.
A1  - Chandrashekar, T. K.
A1  - Sendhil, K.
A1  - Vijayan, C.
A1  - Kelling, Alexandra
A1  - Senge, Mathias O.
T1  - Oxasmaragdyrin-ferrocene and oxacorrole-ferrocene conjugates : Synthesis, structure, and nonlinear optical properties
N2  - Ferrocenyl macrocyclic conjugates involving 22pi oxasmaragdyrins and 18pi oxacorroles have been synthesized and characterized. The direct covalent linkage of the ferrocenyl moiety to the meso position of the macrocycle is achieved by simple oxidative coupling of appropriate precursors with trifluoroacetic acid as catalyst. The electronic coupling between the ferrocenyl moiety and the macrocyclic pi system is apparent from: a) the red shifts (293-718 cm(-1)) of the Soret and Q-bands in the electronic absorption spectra of ferrocenyl conjugates; b) the shift of oxidation potentials (50 130 mV) of both the ferrocene and the corrole rings to the positive potentials; and c) considerable shortening of the C-C bond which connects the ferrocene and the meso-carbon atom of the macrocycle. The single-crystal X-ray structure of oxasmaragdyrin-ferrocene conjugate 9 reveals the planarity of the 22pi skeleton with very small deviations of the meso-carbon atoms. The meso-ferrocenyl substituent has a small dihedral angle of 38degrees, making way for mixing of the molecular orbitals of the ferrocene and the macrocycle. However, the other two meso substituents are almost perpendicular to the mean plane, defined by the three meso carbon atoms. Classical C-(HO)-O-... and nonclassical C- H(...)pi interactions lead to a two-dimensional supramolecular network. Ferrocene-smaragdyrin conjugate 9 bonds to a chloride ion in the protonated form and a rhodium(i) ion in the free base form. Nonlinear optical measurements reveal a larger nonlinear refractive index (-5.83 x 10(-8) cm(2) W-1) and figure of merit (2.28 x 10(-8) cm(3)W(-1)) for the rhodium smaragdyrin-ferrocene conjugate 19 than for the others, suggesting its possible application in optical devices
Y1  - 2004
SN  - 0947-6539
ER  - 
TY  - JOUR
A1  - Kleinpeter, Erich
A1  - Koch, Andreas
A1  - Sahoo, Himansu S.
A1  - Chand, Dillip Kumar
T1  - Anisotropic effect of the nitrate anion-manifestation of diamagnetic proton chemical shifts in the 1H NMR spectra of NO3-coordinated complexes
N2  - The anisotropic effect of the planar nitrate anion NO3- has been ab initio calculated employing the Nucleus- Independent Chemical Shift (NICS) concept of von Ragué Schleyer and visualized as Iso-Chemical-Shielding Surfaces (ICSSs) of various (de)shieldings. Complexation-induced shifts in the 1H NMR spectra of nitrate/metal complexes or nitrate/receptor supramolecules can be separated now into anisotropic influences of the suitably coordinated nitrate anions and effects originating from differential sources.
Y1  - 2008
UR  - http://www.sciencedirect.com/science/article/pii/S0040402008005814
U6  - https://doi.org/10.1016/j.tet.2008.03.063
ER  - 
TY  - JOUR
A1  - Schürmann, Robin Mathis
A1  - Tsering, Thupten
A1  - Tanzer, Katrin
A1  - Denifl, Stephan
A1  - Kumar, S. V. K.
A1  - Bald, Ilko
T1  - Resonant Formation of Strand Breaks in Sensitized Oligonucleotides Induced by Low-Energy Electrons (0.5-9 eV)
JF  - Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition
N2  - Halogenated nucleobases are used as radiosensitizers in cancer radiation therapy, enhancing the reactivity of DNA to secondary low-energy electrons (LEEs). LEEs induce DNA strand breaks at specific energies (resonances) by dissociative electron attachment (DEA). Although halogenated nucleobases show intense DEA resonances at various electron energies in the gas phase, it is inherently difficult to investigate the influence of halogenated nucleobases on the actual DNA strand breakage over the broad range of electron energies at which DEA can take place (<12 eV). By using DNA origami nanostructures, we determined the energy dependence of the strand break cross-section for oligonucleotides modified with 8-bromoadenine ((8Br)A). These results were evaluated against DEA measurements with isolated (8Br)A in the gas phase. Contrary to expectations, the major contribution to strand breaks is from resonances at around 7 eV while resonances at very low energy (<2 eV) have little influence on strand breaks.
KW  - cancer radiation therapy
KW  - dissociative electron attachment
KW  - DNA origami
KW  - DNA radiation damage
KW  - radiosensitizers
Y1  - 2017
U6  - https://doi.org/10.1002/anie.201705504
SN  - 1433-7851
SN  - 1521-3773
VL  - 56
SP  - 10952
EP  - 10955
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Abeysekara, A. U.
A1  - Archer, A.
A1  - Benbow, Wystan
A1  - Bird, Ralph
A1  - Brill, A.
A1  - Brose, Robert
A1  - Buchovecky, M.
A1  - Calderon-Madera, D.
A1  - Christiansen, J. L.
A1  - Cui, W.
A1  - Daniel, M. K.
A1  - Falcone, A.
A1  - Feng, Q.
A1  - Fernandez-Alonso, M.
A1  - Finley, J. P.
A1  - Fortson, Lucy
A1  - Furniss, Amy
A1  - Gent, A.
A1  - Giuri, C.
A1  - Gueta, O.
A1  - Hanna, David
A1  - Hassan, T.
A1  - Hervet, Oliver
A1  - Holder, J.
A1  - Hughes, G.
A1  - Humensky, T. B.
A1  - Johnson, Caitlin A.
A1  - Kaaret, P.
A1  - Kertzman, M.
A1  - Kieda, David
A1  - Krause, Maria
A1  - Krennrich, F.
A1  - Kumar, S.
A1  - Lang, M. J.
A1  - Maier, Gernot
A1  - Moriarty, P.
A1  - Mukherjee, Reshmi
A1  - Nievas-Rosillo, M.
A1  - Ong, R. A.
A1  - Pfrang, Konstantin Johannes
A1  - Pohl, Martin
A1  - Prado, R. R.
A1  - Pueschel, Elisa
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reynolds, P. T.
A1  - Ribeiro, D.
A1  - Richards, G. T.
A1  - Roache, E.
A1  - Rovero, A. C.
A1  - Sadeh, Iftach
A1  - Santander, M.
A1  - Sembroski, G. H.
A1  - Shahinyan, Karlen
A1  - Sushch, Iurii
A1  - Svraka, T.
A1  - Weinstein, A.
A1  - Wells, R. M.
A1  - Wilcox, Patrick
A1  - Wilhelm, Alina
A1  - Williams, David Arnold
A1  - Williamson, T. J.
A1  - Zitzer, B.
T1  - Measurement of the Extragalactic Background Light Spectral Energy Distribution with VERITAS
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - The extragalactic background light (EBL), a diffuse photon field in the optical and infrared range, is a record of radiative processes over the universe?s history. Spectral measurements of blazars at very high energies (>100 GeV) enable the reconstruction of the spectral energy distribution (SED) of the EBL, as the blazar spectra are modified by redshift- and energy-dependent interactions of the gamma-ray photons with the EBL. The spectra of 14 VERITAS-detected blazars are included in a new measurement of the EBL SED that is independent of EBL SED models. The resulting SED covers an EBL wavelength range of 0.56?56 ?m, and is in good agreement with lower limits obtained by assuming that the EBL is entirely due to radiation from cataloged galaxies.
KW  - Extragalactic astronomy
KW  - Active galactic nuclei
KW  - Diffuse radiation
KW  - Cosmology
Y1  - 2019
U6  - https://doi.org/10.3847/1538-4357/ab4817
SN  - 0004-637X
SN  - 1538-4357
VL  - 885
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - GEN
A1  - Kumar, Rohini
A1  - Hesse, Fabienne
A1  - Rao, P. Srinivasa
A1  - Musolff, Andreas
A1  - Jawitz, James
A1  - Sarrazin, Francois
A1  - Samaniego, Luis
A1  - Fleckenstein, Jan H.
A1  - Rakovec, Oldrich
A1  - Thober, S.
A1  - Attinger, Sabine
T1  - Strong hydroclimatic controls on vulnerability to subsurface nitrate contamination across Europe
T2  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Subsurface contamination due to excessive nutrient surpluses is a persistent and widespread problem in agricultural areas across Europe. The vulnerability of a particular location to pollution from reactive solutes, such as nitrate, is determined by the interplay between hydrologic transport and biogeochemical transformations. Current studies on the controls of subsurface vulnerability do not consider the transient behaviour of transport dynamics in the root zone. Here, using state-of-the-art hydrologic simulations driven by observed hydroclimatic forcing, we demonstrate the strong spatiotemporal heterogeneity of hydrologic transport dynamics and reveal that these dynamics are primarily controlled by the hydroclimatic gradient of the aridity index across Europe. Contrasting the space-time dynamics of transport times with reactive timescales of denitrification in soil indicate that similar to 75% of the cultivated areas across Europe are potentially vulnerable to nitrate leaching for at least onethird of the year. We find that neglecting the transient nature of transport and reaction timescale results in a great underestimation of the extent of vulnerable regions by almost 50%. Therefore, future vulnerability and risk assessment studies must account for the transient behaviour of transport and biogeochemical transformation processes.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1352 
KW  - travel time distributions
KW  - groundwater vulnerability
KW  - flux tracking
KW  - transit-time
KW  - water age
KW  - nitrogen
KW  - model
KW  - dynamics
KW  - pollution
KW  - patterns
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-549875
SN  - 1866-8372
IS  - 1
ER  - 
TY  - JOUR
A1  - Kumar, Rohini
A1  - Hesse, Fabienne
A1  - Rao, P. Srinivasa
A1  - Musolff, Andreas
A1  - Jawitz, James
A1  - Sarrazin, Francois
A1  - Samaniego, Luis
A1  - Fleckenstein, Jan H.
A1  - Rakovec, Oldrich
A1  - Thober, S.
A1  - Attinger, Sabine
T1  - Strong hydroclimatic controls on vulnerability to subsurface nitrate contamination across Europe
JF  - Nature Communications
N2  - Subsurface contamination due to excessive nutrient surpluses is a persistent and widespread problem in agricultural areas across Europe. The vulnerability of a particular location to pollution from reactive solutes, such as nitrate, is determined by the interplay between hydrologic transport and biogeochemical transformations. Current studies on the controls of subsurface vulnerability do not consider the transient behaviour of transport dynamics in the root zone. Here, using state-of-the-art hydrologic simulations driven by observed hydroclimatic forcing, we demonstrate the strong spatiotemporal heterogeneity of hydrologic transport dynamics and reveal that these dynamics are primarily controlled by the hydroclimatic gradient of the aridity index across Europe. Contrasting the space-time dynamics of transport times with reactive timescales of denitrification in soil indicate that similar to 75% of the cultivated areas across Europe are potentially vulnerable to nitrate leaching for at least onethird of the year. We find that neglecting the transient nature of transport and reaction timescale results in a great underestimation of the extent of vulnerable regions by almost 50%. Therefore, future vulnerability and risk assessment studies must account for the transient behaviour of transport and biogeochemical transformation processes.
KW  - travel time distributions
KW  - groundwater vulnerability
KW  - flux tracking
KW  - transit-time
KW  - water age
KW  - nitrogen
KW  - model
KW  - dynamics
KW  - pollution
KW  - patterns
Y1  - 2020
U6  - https://doi.org/10.1038/s41467-020-19955-8
SN  - 2041-1723
VL  - 11
IS  - 1
SP  - 1
EP  - 10
PB  - Nature Publishing Group UK
CY  - London
ER  -