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  - 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  - JOUR
A1  - Benbow, W.
A1  - Bird, R.
A1  - Brill, A.
A1  - Brose, Robert
A1  - Chromey, A. J.
A1  - Daniel, M. K.
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Gillanders, G. H.
A1  - Giuri, C.
A1  - Gueta, O.
A1  - Hanna, D.
A1  - Halpern, J. P.
A1  - Hassan, Tarek
A1  - Holder, J.
A1  - Hughes, G.
A1  - Humensky, T. B.
A1  - Joyce, Amy M.
A1  - Kaaret, P.
A1  - Kar, P.
A1  - Kelley-Hoskins, N.
A1  - Kertzman, M.
A1  - Kieda, D.
A1  - Krause, M.
A1  - Lang, M. J.
A1  - Lin, T. T. Y.
A1  - Maier, Gernot
A1  - Matthews, N.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nieto, D.
A1  - Nievas-Rosillos, M.
A1  - Ong, R. A.
A1  - Park, N.
A1  - Petrashyk, A.
A1  - Pohl, Martin
A1  - Pueschel, Elisa
A1  - Quinn, John
A1  - Ragan, K.
A1  - Reynolds, P. T.
A1  - Richards, G. T.
A1  - Roache, E.
A1  - Rulten, C.
A1  - Sadeh, Iftach
A1  - Santander, M.
A1  - Sembroski, G. H.
A1  - Shahinyan, K.
A1  - Sushch, Iurii
A1  - Wakely, S. P.
A1  - Wells, R. M.
A1  - Wilcox, P.
A1  - Wilhelm, Alina
A1  - Williams, David A.
A1  - Williamson, T. J.
T1  - Direct measurement of stellar angular diameters by the VERITAS Cherenkov telescopes
JF  - Nature astronomy
N2  - The angular size of a star is a critical factor in determining its basic properties1. Direct measurement of stellar angular diameters is difficult: at interstellar distances stars are generally too small to resolve by any individual imaging telescope. This fundamental limitation can be overcome by studying the diffraction pattern in the shadow cast when an asteroid occults a star2, but only when the photometric uncertainty is smaller than the noise added by atmospheric scintillation3. Atmospheric Cherenkov telescopes used for particle astrophysics observations have not generally been exploited for optical astronomy due to the modest optical quality of the mirror surface. However, their large mirror area makes them well suited for such high-time-resolution precision photometry measurements4. Here we report two occultations of stars observed by the Very Energetic Radiation Imaging Telescope Array System (VERITAS)5 Cherenkov telescopes with millisecond sampling, from which we are able to provide a direct measurement of the occulted stars’ angular diameter at the ≤0.1 mas scale. This is a resolution never achieved before with optical measurements and represents an order of magnitude improvement over the equivalent lunar occultation method6. We compare the resulting stellar radius with empirically derived estimates from temperature and brightness measurements, confirming the latter can be biased for stars with ambiguous stellar classifications.
Y1  - 2019
U6  - https://doi.org/10.1038/s41550-019-0741-z
SN  - 2397-3366
VL  - 3
IS  - 6
SP  - 511
EP  - 516
PB  - Nature Publ. Group
CY  - London
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  - 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  - 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  - 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  - 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  - Abeysekara, A. U.
A1  - Archer, A.
A1  - Benbow, Wystan
A1  - Bird, Ralph
A1  - Brill, A.
A1  - Brose, Robert
A1  - Buckley, J. H.
A1  - Christiansen, Jessie L.
A1  - Chromey, A. J.
A1  - Daniel, M. K.
A1  - Falcone, A.
A1  - Feng, Qi
A1  - Finley, John P.
A1  - Fortson, L.
A1  - Furniss, Amy
A1  - Gillanders, Gerard H.
A1  - Gueta, O.
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  - Kertzman, M.
A1  - Kieda, David
A1  - Krause, Maria
A1  - Krennrich, F.
A1  - Lang, M. J.
A1  - Moriarty, P.
A1  - Mukherjee, Reshmi
A1  - Ong, R. A.
A1  - Otte, A. N.
A1  - Park, N.
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  - Scott, S. S.
A1  - Sembroski, G. H.
A1  - Shahinyan, Karlen
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  - Kaur, A.
T1  - VERITAS Observations of the BL Lac Object TXS 0506+056
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics ; Part 2, Letters
N2  - On 2017 September 22, the IceCube Neutrino Observatory reported the detection of the high-energy neutrino event IC 170922A, of potential astrophysical origin. It was soon determined that the neutrino direction was consistent with the location of the gamma-ray blazar TXS 0506+056. (3FGL J0509.4+ 0541), which was in an elevated gamma-ray emission state as measured by the Fermi satellite. Very Energetic Radiation Imaging Telescope Array System (VERITAS) observations of the neutrino/blazar region started on 2017 September 23 in response to the neutrino alert and continued through 2018 February 6. While no significant very-high-energy (VHE; E > 100 GeV) emission was observed from the blazar by VERITAS in the two-week period immediately following the IceCube alert, TXS 0506+ 056 was detected by VERITAS with a significance of 5.8 standard deviations (sigma) in the full 35 hr data set. The average photon flux of the source during this period was (8.9 +/- 1.6). x. 10(-12) cm(-2) s(-1), or 1.6% of the Crab Nebula flux, above an energy threshold of 110 GeV, with a soft spectral index of 4.8. +/-. 1.3.
KW  - astroparticle physics
KW  - BL Lacertae objects: individual (TXS 0506+056, VER J0509+057)
KW  - gamma rays: galaxies
KW  - quasars: general
KW  - neutrinos
Y1  - 2018
U6  - https://doi.org/10.3847/2041-8213/aad053
SN  - 2041-8205
SN  - 2041-8213
VL  - 861
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Abeysekara, A. U.
A1  - Benbow, Wystan
A1  - Bird, Ralph
A1  - Brantseg, T.
A1  - Brose, Robert
A1  - Buchovecky, M.
A1  - Buckley, J. H.
A1  - Bugaev, V.
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  - Gillanders, Gerard H.
A1  - Gunawardhana, Isuru
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  - Krennrich, F.
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, N.
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, M.
A1  - Sembroski, G. H.
A1  - Shahinyan, Karlen
A1  - Wakely, S. P.
A1  - Weinstein, A.
A1  - Wells, R. M.
A1  - Wilcox, P.
A1  - Williams, D. A.
A1  - Zitzer, B.
A1  - Jorstad, Svetlana G.
A1  - Marscher, Alan P.
A1  - Lister, Matthew L.
A1  - Kovalev, Yuri Y.
A1  - Pushkarev, A. B.
A1  - Savolainen, Tuomas
A1  - Agudo, I.
A1  - Molina, S. N.
A1  - Gomez, J. L.
A1  - Larionov, Valeri M.
A1  - Borman, G. A.
A1  - Mokrushina, A. A.
A1  - Tornikoski, Merja
A1  - Lahteenmaki, A.
A1  - Chamani, W.
A1  - Enestam, S.
A1  - Kiehlmann, S.
A1  - Hovatta, Talvikki
A1  - Smith, P. S.
A1  - Pontrelli, P.
T1  - Multiwavelength Observations of the Blazar BL Lacertae
BT  - a new Fast TeV Gamma-Ray Flare
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - Combined with measurements made by very-long-baseline interferometry, the observations of fast TeV gamma-ray flares probe the structure and emission mechanism of blazar jets. However, only a handful of such flares have been detected to date, and only within the last few years have these flares been observed from lower-frequency-peaked BL. Lac objects and flat-spectrum radio quasars. We report on a fast TeV gamma-ray flare from the blazar BL. Lacertae observed by the Very Energetic Radiation Imaging Telescope Array System (VERITAS). with a rise time of similar to 2.3 hr and a decay time of similar to 36 min. The peak flux above 200 GeV is (4.2 +/- 0.6) x 10(-6) photon m(-2) s(-1) measured with a 4-minute-binned light curve, corresponding to similar to 180% of the flux that is observed from the Crab Nebula above the same energy threshold. Variability contemporaneous with the TeV gamma-ray flare was observed in GeV gamma-ray, X-ray, and optical flux, as well as in optical and radio polarization. Additionally, a possible moving emission feature with superluminal apparent velocity was identified in Very Long Baseline Array observations at 43 GHz, potentially passing the radio core of the jet around the time of the gamma-ray flare. We discuss the constraints on the size, Lorentz factor, and location of the emitting region of the flare, and the interpretations with several theoretical models that invoke relativistic plasma passing stationary shocks.
KW  - BL Lacertae objects: individual (BL Lacertae = VER J2202+422)
KW  - galaxies: active
Y1  - 2018
U6  - https://doi.org/10.3847/1538-4357/aab35c
SN  - 0004-637X
SN  - 1538-4357
VL  - 856
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Abeysekara, A. U.
A1  - Archer, A.
A1  - Benbow, Wystan
A1  - Bird, Ralph
A1  - Brose, Robert
A1  - Buchovecky, M.
A1  - Bugaev, V.
A1  - Connolly, M. P.
A1  - Cui, Wei
A1  - Errando, Manel
A1  - Falcone, A.
A1  - Feng, Qi
A1  - Finley, John P.
A1  - Flinders, A.
A1  - Fortson, L.
A1  - Furniss, Amy
A1  - Gillanders, Gerard H.
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  - Kelley-Hoskins, N.
A1  - Kertzman, M.
A1  - Kieda, David
A1  - Krause, Maria
A1  - Krennrich, F.
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  - Park, N.
A1  - Perkins, Jeremy S.
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  - Rulten, C.
A1  - Sadeh, I.
A1  - Santander, M.
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  - Zitzer, B.
A1  - Vurm, Indrek
A1  - Beloborodov, Andrei
T1  - A Strong Limit on the Very-high-energy Emission from GRB 150323A
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - On 2015 March 23, the Very Energetic Radiation Imaging Telescope Array System (VERITAS) responded to a Swift-Burst Alert Telescope (BAT) detection of a gamma-ray burst, with observations beginning 270 s after the onset of BAT emission, and only 135 s after the main BAT emission peak. No statistically significant signal is detected above 140 GeV. The VERITAS upper limit on the fluence in a 40-minute integration corresponds to about 1% of the prompt fluence. Our limit is particularly significant because the very-high-energy (VHE) observation started only similar to 2 minutes after the prompt emission peaked, and Fermi-Large Area Telescope observations of numerous other bursts have revealed that the high-energy emission is typically delayed relative to the prompt radiation and lasts significantly longer. Also, the proximity of GRB 150323A (z = 0.593) limits the attenuation by the extragalactic background light to similar to 50% at 100-200 GeV. We conclude that GRB 150323A had an intrinsically very weak high-energy afterglow, or that the GeV spectrum had a turnover below similar to 100 GeV. If the GRB exploded into the stellar wind of a massive progenitor, the VHE non-detection constrains the wind density parameter to be A greater than or similar to 3 x 10(11) g . cm(-1), consistent with a standard Wolf-Rayet progenitor. Alternatively, the VHE emission from the blast wave would be weak in a very tenuous medium such as the interstellar medium, which therefore cannot be ruled out as the environment of GRB 150323A.
KW  - gamma rays: general
KW  - gamma-ray burst: general
KW  - gamma-ray burst: individual (GRB 150323A)
Y1  - 2018
U6  - https://doi.org/10.3847/1538-4357/aab371
SN  - 0004-637X
SN  - 1538-4357
VL  - 857
IS  - 1
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Ahnen, M. L.
A1  - Ansoldi, S.
A1  - Antonelli, L. A.
A1  - Antoranz, P.
A1  - Babic, A.
A1  - Banerjee, B.
A1  - Bangale, P.
A1  - de Almeida, U. Barres
A1  - Barrio, J. A.
A1  - Gonzalez, J. Becerra
A1  - Bednarek, W.
A1  - Bernardini, E.
A1  - Berti, A.
A1  - Biasuzzi, B.
A1  - Biland, A.
A1  - Blanch, O.
A1  - Bonnefoy, S.
A1  - Bonnoli, G.
A1  - Borracci, F.
A1  - Bretz, T.
A1  - Buson, S.
A1  - Carosi, A.
A1  - Chatterjee, A.
A1  - Clavero, R.
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  - Wilhelmi, E. de Ona
A1  - Di Pierro, F.
A1  - Doert, M.
A1  - Dominguez, A.
A1  - Prester, D. Dominis
A1  - Dorner, D.
A1  - Doro, M.
A1  - Einecke, S.
A1  - Glawion, D. Eisenacher
A1  - Elsaesser, D.
A1  - Engelkemeier, M.
A1  - Ramazani, V. Fallah
A1  - Fernandez-Barral, A.
A1  - Fidalgo, D.
A1  - Fonseca, M. V.
A1  - Font, L.
A1  - Frantzen, K.
A1  - Fruck, C.
A1  - Galindo, D.
A1  - Lopez, R. J. Garcia
A1  - Garczarczyk, M.
A1  - Terrats, D. Garrido
A1  - Gaug, M.
A1  - Giammaria, P.
A1  - Godinovic, N.
A1  - Gonzalez Munoz, A.
A1  - Gora, D.
A1  - Guberman, D.
A1  - Hadasch, D.
A1  - Hahn, A.
A1  - Hanabata, Y.
A1  - Hayashida, M.
A1  - Herrera, J.
A1  - Hose, J.
A1  - Hrupec, D.
A1  - Hughes, G.
A1  - Idec, W.
A1  - Kodani, K.
A1  - Konno, Y.
A1  - Kubo, H.
A1  - Kushida, J.
A1  - La Barbera, A.
A1  - Lelas, D.
A1  - Lindfors, E.
A1  - Lombardi, S.
A1  - Longo, F.
A1  - Lopez, M.
A1  - Lopez-Coto, R.
A1  - Majumdar, P.
A1  - Makariev, M.
A1  - Mallot, K.
A1  - Maneva, G.
A1  - Manganaro, M.
A1  - Mannheim, K.
A1  - Maraschi, L.
A1  - Marcote, B.
A1  - Mariotti, M.
A1  - Martinez, M.
A1  - Mazin, D.
A1  - Menzel, U.
A1  - Miranda, J. M.
A1  - Mirzoyan, R.
A1  - Moralejo, A.
A1  - Moretti, E.
A1  - Nakajima, D.
A1  - Neustroev, V.
A1  - Niedzwiecki, A.
A1  - Rosillo, M. Nievas
A1  - Nilsson, K.
A1  - Nishijima, K.
A1  - Noda, K.
A1  - Nogues, L.
A1  - Overkemping, A.
A1  - Paiano, S.
A1  - Palacio, J.
A1  - Palatiello, M.
A1  - Paneque, D.
A1  - Paoletti, R.
A1  - Paredes, J. M.
A1  - Paredes-Fortuny, X.
A1  - Pedaletti, G.
A1  - Peresano, M.
A1  - Perri, L.
A1  - Persic, M.
A1  - Poutanen, J.
A1  - Moroni, P. G. Prada
A1  - Prandini, E.
A1  - Puljak, I.
A1  - Reichardt, I.
A1  - Rhode, W.
A1  - Ribo, M.
A1  - Rico, J.
A1  - Rodriguez Garcia, J.
A1  - Saito, T.
A1  - Satalecka, K.
A1  - Schroder, S.
A1  - Schultz, C.
A1  - Schweizer, T.
A1  - Shore, S. N.
A1  - Sillanpaa, A.
A1  - Sitarek, J.
A1  - Snidaric, I.
A1  - Sobczynska, D.
A1  - Stamerra, A.
A1  - Steinbring, T.
A1  - Strzys, M.
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  - Torres, D. F.
A1  - Toyama, T.
A1  - Treves, A.
A1  - Vanzo, G.
A1  - Verguilov, V.
A1  - Vovk, I.
A1  - Ward, J. E.
A1  - Will, M.
A1  - Wu, M. H.
A1  - Zanin, R.
A1  - Abeysekara, A. U.
A1  - Archambault, S.
A1  - Archer, A.
A1  - Benbow, W.
A1  - Bird, R.
A1  - Buchovecky, M.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Dickinson, H. J.
A1  - Falcone, A.
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Fleischhack, H.
A1  - Flinders, A.
A1  - Fortson, L.
A1  - Gillanders, G. H.
A1  - Griffin, S.
A1  - Grube, J.
A1  - Huetten, M.
A1  - Hanna, D.
A1  - Holder, J.
A1  - Humensky, T. B.
A1  - Kaaret, P.
A1  - Kar, P.
A1  - Kelley-Hoskins, N.
A1  - Kertzman, M.
A1  - Kieda, D.
A1  - Krause, M.
A1  - Krennrich, F.
A1  - Lang, M. J.
A1  - Maier, G.
A1  - McCann, A.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nieto, D.
A1  - Ong, R. A.
A1  - Otte, N.
A1  - Park, N.
A1  - Perkins, J.
A1  - Pichel, A.
A1  - Pohl, M.
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, M.
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  - Wilcox, P.
A1  - Wilhelm, Alina
A1  - Williams, D. A.
A1  - Zitzer, B.
A1  - Razzaque, S.
A1  - Villata, M.
A1  - Raiteri, C. M.
A1  - Aller, H. D.
A1  - Aller, M. F.
A1  - Larionov, V. M.
A1  - Arkharov, A. A.
A1  - Blinov, D. A.
A1  - Efimova, N. V.
A1  - Grishina, T. S.
A1  - Hagen-Thorn, V. A.
A1  - Kopatskaya, E. N.
A1  - Larionova, L. V.
A1  - Larionova, E. G.
A1  - Morozova, D. A.
A1  - Troitsky, I. S.
A1  - Ligustri, R.
A1  - Calcidese, P.
A1  - Berdyugin, A.
A1  - Kurtanidze, O. M.
A1  - Nikolashvili, M. G.
A1  - Kimeridze, G. N.
A1  - Sigua, L. A.
A1  - Kurtanidze, S. O.
A1  - Chigladze, R. A.
A1  - Chen, W. P.
A1  - Koptelova, E.
A1  - Sakamoto, T.
A1  - Sadun, A. C.
A1  - Moody, J. W.
A1  - Pace, C.
A1  - Pearson, R.
A1  - Yatsu, Y.
A1  - Mori, Y.
A1  - Carraminyana, A.
A1  - Carrasco, L.
A1  - de la Fuente, E.
A1  - Norris, J. P.
A1  - Smith, P. S.
A1  - Wehrle, A.
A1  - Gurwell, M. A.
A1  - Zook, A.
A1  - Pagani, C.
A1  - Perri, M.
A1  - Capalbi, M.
A1  - Cesarini, A.
A1  - Krimm, H. A.
A1  - Kovalev, Y. Y.
A1  - Kovalev, Yu. A.
A1  - Ros, E.
A1  - Pushkarev, A. B.
A1  - Lister, M. L.
A1  - Sokolovsky, K. V.
A1  - Kadler, M.
A1  - Piner, G.
A1  - Lahteenmaki, A.
A1  - Tornikoski, M.
A1  - Angelakis, E.
A1  - Krichbaum, T. P.
A1  - Nestoras, I.
A1  - Fuhrmann, L.
A1  - Zensus, J. A.
A1  - Cassaro, P.
A1  - Orlati, A.
A1  - Maccaferri, G.
A1  - Leto, P.
A1  - Giroletti, M.
A1  - Richards, J. L.
A1  - Max-Moerbeck, W.
A1  - Readhead, A. C. S.
T1  - Multiband variability studies and novel broadband SED modeling of Mrk 501 in 2009
JF  - Astronomy and astrophysics : an international weekly journal
N2  - Aims. We present an extensive study of the BL Lac object Mrk 501 based on a data set collected during the multi-instrument campaign spanning from 2009 March 15 to 2009 August 1, which includes, among other instruments, MAGIC, VERITAS, Whipple 10 m, and Fermi-LAT to cover the gamma-ray range from 0.1 GeV to 20 TeV; RXTE and Swift to cover wavelengths from UV to hard X-rays; and GASP-WEBT, which provides coverage of radio and optical wavelengths. Optical polarization measurements were provided for a fraction of the campaign by the Steward and St. Petersburg observatories. We evaluate the variability of the source and interband correlations, the gamma-ray flaring activity occurring in May 2009, and interpret the results within two synchrotron self-Compton (SSC) scenarios. Methods. The multiband variability observed during the full campaign is addressed in terms of the fractional variability, and the possible correlations are studied by calculating the discrete correlation function for each pair of energy bands where the significance was evaluated with dedicated Monte Carlo simulations. The space of SSC model parameters is probed following a dedicated grid-scan strategy, allowing for a wide range of models to be tested and offering a study of the degeneracy of model-to-data agreement in the individual model parameters, hence providing a less biased interpretation than the "single-curve SSC model adjustment" typically reported in the literature. Results. We find an increase in the fractional variability with energy, while no significant interband correlations of flux changes are found on the basis of the acquired data set. The SSC model grid-scan shows that the flaring activity around May 22 cannot be modeled adequately with a one-zone SSC scenario (using an electron energy distribution with two breaks), while it can be suitably described within a two (independent) zone SSC scenario. Here, one zone is responsible for the quiescent emission from the averaged 4.5-month observing period, while the other one, which is spatially separated from the first, dominates the flaring emission occurring at X-rays and very-high-energy (> 100 GeV, VHE) gamma-rays. The flaring activity from May 1, which coincides with a rotation of the electric vector polarization angle (EVPA), cannot be satisfactorily reproduced by either a one-zone or a two-independent-zone SSC model, yet this is partially affected by the lack of strictly simultaneous observations and the presence of large flux changes on sub-hour timescales (detected at VHE gamma rays). Conclusions. The higher variability in the VHE emission and lack of correlation with the X-ray emission indicate that, at least during the 4.5-month observing campaign in 2009, the highest energy (and most variable) electrons that are responsible for the VHE gamma rays do not make a dominant contribution to the similar to 1 keV emission. Alternatively, there could be a very variable component contributing to the VHE gamma-ray emission in addition to that coming from the SSC scenario. The studies with our dedicated SSC grid-scan show that there is some degeneracy in both the one-zone and the two-zone SSC scenarios probed, with several combinations of model parameters yielding a similar model-to-data agreement, and some parameters better constrained than others. The observed gamma-ray flaring activity, with the EVPA rotation coincident with the first gamma-ray flare, resembles those reported previously for low frequency peaked blazars, hence suggesting that there are many similarities in the flaring mechanisms of blazars with different jet properties.
KW  - BL Lacertae objects: individual: Markarian 501
KW  - methods: data analysis
Y1  - 2017
U6  - https://doi.org/10.1051/0004-6361/201629540
SN  - 1432-0746
VL  - 603
PB  - EDP Sciences
CY  - Les Ulis
ER  - 
TY  - JOUR
A1  - Archambault, S.
A1  - Archer, A.
A1  - Benbow, W.
A1  - Bird, R.
A1  - Bourbeau, E.
A1  - Brantseg, T.
A1  - Buchovecky, M.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Byrum, K.
A1  - Cerruti, M.
A1  - Christiansen, J. L.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Daniel, M. K.
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Fleischhack, H.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Geringer-Sameth, A.
A1  - Griffin, S.
A1  - Grube, J.
A1  - Hütten, M.
A1  - Hakansson, N.
A1  - Hanna, D.
A1  - Hervet, O.
A1  - Holder, J.
A1  - Hughes, G.
A1  - Hummensky, B.
A1  - Johnson, C. A.
A1  - Kaaret, P.
A1  - Kar, P.
A1  - Kelley-Hoskins, N.
A1  - Kertzman, M.
A1  - Kieda, D.
A1  - Koushiappas, S.
A1  - Krause, M.
A1  - Krennrich, F.
A1  - Lang, M. J.
A1  - Lin, T. T. Y.
A1  - McArthur, S.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nieto, D.
A1  - Ong, R. A.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Pohl, M.
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  - Smith, A. W.
A1  - Staszak, D.
A1  - Telezhinsky, Igor O.
A1  - Trepanier, S.
A1  - Tucci, J. V.
A1  - Tyler, J.
A1  - Wakely, S. P.
A1  - Weinstein, A.
A1  - Wilcox, P.
A1  - Williams, D. A.
A1  - Zitzer, B.
T1  - Dark matter constraints from a joint analysis of dwarf Spheroidal galaxy observations with VERITAS
JF  - Physical review : D, Particles, fields, gravitation, and cosmology
N2  - We present constraints on the annihilation cross section of weakly interacting massive particles dark matter based on the joint statistical analysis of four dwarf galaxies with VERITAS. These results are derived from an optimized photon weighting statistical technique that improves on standard imaging atmospheric Cherenkov telescope (IACT) analyses by utilizing the spectral and spatial properties of individual photon events. We report on the results of similar to 230 hours of observations of five dwarf galaxies and the joint statistical analysis of four of the dwarf galaxies. We find no evidence of gamma-ray emission from any individual dwarf nor in the joint analysis. The derived upper limit on the dark matter annihilation cross section from the joint analysis is 1.35 x 10(-23) cm(3) s(-1) at 1 TeV for the bottom quark (b (b) over bar) final state, 2.85 x 10(-24) cm(3) s(-1) at 1 TeV for the tau lepton (tau+tau(-)) final state and 1.32 x 10-25 cm(3) s(-1) at 1 TeV for the gauge boson (gamma gamma) final state.
Y1  - 2017
U6  - https://doi.org/10.1103/PhysRevD.95.082001
SN  - 2470-0010
SN  - 2470-0029
VL  - 95
IS  - 8
PB  - American Physical Society
CY  - College Park
ER  - 
TY  - JOUR
A1  - Archambault, S.
A1  - Archer, A.
A1  - Benbow, W.
A1  - Buchovecky, M.
A1  - Bugaev, V.
A1  - Cerruti, M.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Falcone, A.
A1  - Alonso, M. Fernandez
A1  - Finley, J. P.
A1  - Fleischhack, H.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Griffin, S.
A1  - Hutten, M.
A1  - Hervet, O.
A1  - Holder, J.
A1  - Humensky, T. B.
A1  - Johnson, C. A.
A1  - Kaaret, P.
A1  - Kar, P.
A1  - Kieda, D.
A1  - Krause, M.
A1  - Krennrich, F.
A1  - Lang, M. J.
A1  - Lin, T. T. Y.
A1  - Maier, G.
A1  - McArthur, S.
A1  - Moriarty, P.
A1  - Nieto, D.
A1  - Ong, R. A.
A1  - Otte, A. N.
A1  - Pohl, M.
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  - Sadeh, I.
A1  - Shahinyan, K.
A1  - Staszak, D.
A1  - Telezhinsky, Igor O.
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  - Search for Magnetically Broadened Cascade Emission from Blazars with VERITAS
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - We present a search for magnetically broadened gamma-ray emission around active galactic nuclei (AGNs), using VERITAS observations of seven hard-spectrum blazars. A cascade process occurs when multi-TeV gamma-rays from an AGN interact with extragalactic background light (EBL) photons to produce electron-positron pairs, which then interact with cosmic microwave background photons via inverse-Compton scattering to produce gamma-rays. Due to the deflection of the electron- positron pairs, a non-zero intergalactic magnetic field (IGMF) would potentially produce detectable effects on the angular distribution of the cascade emission. In particular, an angular broadening compared to the unscattered emission could occur. Through non-detection of angularly broadened emission from 1ES 1218 vertical bar 304, the source with the largest predicted cascade fraction, we exclude a range of IGMF strengths around 10(-14) G at the 95% confidence level. The extent of the exclusion range varies with the assumptions made about the intrinsic spectrum of 1ES. 1218+304 and the EBL model used in the simulation of the cascade process. All of the sources are used to set limits on the flux due to extended emission.
KW  - BL Lacertae objects: general
KW  - galaxies: active
KW  - gamma rays: galaxies
KW  - magnetic fields
Y1  - 2017
U6  - https://doi.org/10.3847/1538-4357/835/2/288
SN  - 0004-637X
SN  - 1538-4357
VL  - 835
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  - 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  - 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  - 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  - Archambault, S.
A1  - Archer, A.
A1  - Benbow, W.
A1  - Bird, Ralph
A1  - Bourbeau, E.
A1  - Bouvier, A.
A1  - Buchovecky, M.
A1  - Bugaev, V.
A1  - Cardenzana, J. V.
A1  - Cerruti, M.
A1  - Ciupik, L.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Daniel, M. K.
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  - 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  - Kar, P.
A1  - Kertzman, M.
A1  - Kieda, D.
A1  - Krause, M.
A1  - Lang, M. J.
A1  - Lin, T. T. Y.
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  - 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  - Sembroski, G. H.
A1  - Shahinyan, K.
A1  - Staszak, D.
A1  - Telezhinsky, Igor O.
A1  - Trepanier, S.
A1  - Wakely, S. P.
A1  - Weinstein, A.
A1  - Wilcox, P.
A1  - Williams, D. A.
A1  - Zitzer, B.
T1  - Gamma-ray observations under bright moonlight with VERITAS
JF  - Astroparticle physics
N2  - Imaging atmospheric Cherenkov telescopes (IACTs) are equipped with sensitive photomultiplier tube (PMT) cameras. Exposure to high levels of background illumination degrades the efficiency of and potentially destroys these photo-detectors over time, so IACTs cannot be operated in the same configuration in the presence of bright moonlight as under dark skies. Since September 2012, observations have been carried out with the VERITAS IACTs under bright moonlight (defined as about three times the night-sky-background (NSB) of a dark extragalactic field, typically occurring when Moon illumination > 35%) in two observing modes, firstly by reducing the voltage applied to the PMTs and, secondly, with the addition of ultra-violet (UV) bandpass filters to the cameras. This has allowed observations at up to about 30 times previous NSB levels (around 80% Moon illumination), resulting in 30% more observing time between the two modes over the course of a year. These additional observations have already allowed for the detection of a flare from the 1ES 1727 + 502 and for an observing program targeting a measurement of the cosmic-ray positron fraction. We provide details of these new observing modes and their performance relative to the standard VERITAS observations. (C) 2017 Elsevier B.V. All rights reserved.
KW  - Instrumentation
KW  - Moonlight
KW  - Observing methods
KW  - VERITAS
KW  - IACT
Y1  - 2017
U6  - https://doi.org/10.1016/j.astropartphys.2017.03.001
SN  - 0927-6505
SN  - 1873-2852
VL  - 91
SP  - 34
EP  - 43
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Aliu, E.
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  - Cardenzana, J. V.
A1  - Cerruti, M.
A1  - Chen, Xuhui
A1  - Ciupik, L.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Dickinson, H. 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  - 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  - Lang, M. J.
A1  - Loo, A.
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  - Pandel, D.
A1  - Park, N.
A1  - Pelassa, V.
A1  - Petrashyk, A.
A1  - Pohl, M.
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  - 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  - Weiner, O. M.
A1  - Weinstein, A.
A1  - Wilhelm, Alina
A1  - Williams, D. A.
A1  - Zitzer, B.
A1  - Chernyakova, M.
A1  - Roberts, M. S. E.
T1  - A SEARCH FOR VERY HIGH ENERGY GAMMA RAYS FROM THE MISSING LINK BINARY PULSAR J1023+0038 WITH VERITAS
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - The binary millisecond radio pulsar PSR J1023+0038 exhibits many characteristics similar to the gamma-ray binary system PSR B1259-63/LS 2883, making it an ideal candidate for the study of high-energy nonthermal emission. It has been the subject of multiwavelength campaigns following the disappearance of the pulsed radio emission in 2013 June, which revealed the appearance of an accretion disk around the neutron star. We present the results of very high energy (VHE) gamma-ray observations carried out by the Very Energetic Radiation Imaging Telescope Array System before and after this change of state. Searches for steady and pulsed emission of both data sets yield no significant gamma-ray signal above 100 GeV, and upper limits are given for both a steady and pulsed gamma-ray flux. These upper limits are used to constrain the magnetic field strength in the shock region of the PSR J1023+0038 system. Assuming that VHE gamma rays are produced via an inverse Compton mechanism in the shock region, we constrain the shock magnetic field to be greater than similar to 2 G before the disappearance of the radio pulsar and greater than similar to 10 G afterward.
KW  - binaries: general
KW  - gamma rays: general
KW  - pulsars: general
KW  - pulsars: individual (PSR J1023+0038)
Y1  - 2016
U6  - https://doi.org/10.3847/0004-637X/831/2/193
SN  - 0004-637X
SN  - 1538-4357
VL  - 831
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  -