TY  - JOUR
A1  - Acciari, V. A.
A1  - Aliu, E.
A1  - Arlen, T.
A1  - Aune, T.
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Bradbury, S. M.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Byrum, K.
A1  - Cannon, A.
A1  - Cesarini, A.
A1  - Christiansen, J. L.
A1  - Ciupik, L.
A1  - Collins-Hughes, E.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Duke, C.
A1  - Errando, M.
A1  - Falcone, A.
A1  - Finley, J. P.
A1  - Finnegan, G.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Galante, N.
A1  - Gall, D.
A1  - Godambe, S.
A1  - Griffin, S.
A1  - Grube, J.
A1  - Guenette, R.
A1  - Gyuk, G.
A1  - Hanna, D.
A1  - Holder, J.
A1  - Hughes, G.
A1  - Hui, C. M.
A1  - Humensky, T. B.
A1  - Jackson, D. J.
A1  - Kaaret, P.
A1  - Karlsson, N.
A1  - Kertzman, M.
A1  - Kieda, D.
A1  - Krawczynski, H.
A1  - Krennrich, F.
A1  - Lang, M. J.
A1  - Madhavan, A. S.
A1  - Maier, G.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Moriarty, P.
A1  - Newbold, M. D.
A1  - Ong, R. A.
A1  - Orr, M.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Perkins, J. S.
A1  - Pohl, Martin
A1  - Prokoph, H.
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reyes, L. C.
A1  - Reynolds, P. T.
A1  - Roache, E.
A1  - Rose, H. J.
A1  - Ruppel, J.
A1  - Saxon, D. B.
A1  - Schroedter, M.
A1  - Sembroski, G. H.
A1  - Sentuerk, G. D.
A1  - Smith, A. W.
A1  - Staszak, D.
A1  - Swordy, S. P.
A1  - Tesic, G.
A1  - Theiling, M.
A1  - Thibadeau, S.
A1  - Tsurusaki, K.
A1  - Varlotta, A.
A1  - Vassiliev, V. V.
A1  - Vincent, S.
A1  - Vivier, M.
A1  - Wakely, S. P.
A1  - Ward, J. E.
A1  - Weekes, T. C.
A1  - Weinstein, A.
A1  - Weisgarber, T.
A1  - Williams, D. A.
A1  - Wood, M.
T1  - Veritas observations of gamma-ray bursts detected by swift
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - We present the results of 16 Swift-triggered Gamma-ray burst (GRB) follow-up observations taken with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) telescope array from 2007 January to 2009 June. The median energy threshold and response time of these observations were 260 GeV and 320 s, respectively. Observations had an average duration of 90 minutes. Each burst is analyzed independently in two modes: over the whole duration of the observations and again over a shorter timescale determined by the maximum VERITAS sensitivity to a burst with a t(-1.5) time profile. This temporal model is characteristic of GRB afterglows with high-energy, long-lived emission that have been detected by the Large Area Telescope on board the Fermi satellite. No significant very high energy (VHE) gamma-ray emission was detected and upper limits above the VERITAS threshold energy are calculated. The VERITAS upper limits are corrected for gamma-ray extinction by the extragalactic background light and interpreted in the context of the keV emission detected by Swift. For some bursts the VHE emission must have less power than the keV emission, placing constraints on inverse Compton models of VHE emission.
KW  - astroparticle physics
KW  - gamma-ray burst: general
Y1  - 2011
U6  - https://doi.org/10.1088/0004-637X/743/1/62
SN  - 0004-637X
VL  - 743
IS  - 1
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - tAliu, E.
A1  - Archambault, S.
A1  - Arlen, T.
A1  - Aune, T.
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Bird, R.
A1  - Bouvier, A.
A1  - Bradbury, S. M.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Byrum, K.
A1  - Cannon, A.
A1  - Cesarini, A.
A1  - Ciupik, L.
A1  - Collins-Hughes, E.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Dickherber, R.
A1  - Duke, C.
A1  - Dumm, J.
A1  - Dwarkadas, Vikram V.
A1  - Errando, M.
A1  - Falcone, A.
A1  - Federici, Simone
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Finnegan, G.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Galante, N.
A1  - Gall, D.
A1  - Gillanders, G. H.
A1  - Godambe, S.
A1  - Gotthelf, E. V.
A1  - Griffin, S.
A1  - Grube, J.
A1  - Gyuk, G.
A1  - Hanna, D.
A1  - Holder, J.
A1  - Huan, H.
A1  - Hughes, G.
A1  - Humensky, T. B.
A1  - Kaaret, P.
A1  - Karlsson, N.
A1  - Kertzman, M.
A1  - Khassen, Y.
A1  - Kieda, D.
A1  - Krawczynski, H.
A1  - Krennrich, F.
A1  - Lang, M. J.
A1  - Lee, K.
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  - Nelson, T.
A1  - de Bhroithe, A. O'Faolain
A1  - Ong, R. A.
A1  - Orr, M.
A1  - Otte, A. N.
A1  - Pandel, D.
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  - Roache, E.
A1  - Rose, H. J.
A1  - Ruppel, Jens
A1  - Saxon, D. B.
A1  - Schroedter, M.
A1  - Sembroski, G. H.
A1  - Sentuerk, G. D.
A1  - Skole, C.
A1  - Telezhinsky, Igor O.
A1  - Tesic, G.
A1  - Theiling, M.
A1  - Thibadeau, S.
A1  - Tsurusaki, K.
A1  - Tyler, J.
A1  - Varlotta, A.
A1  - Vassiliev, V. V.
A1  - Vincent, S.
A1  - Wakely, S. P.
A1  - Ward, J. E.
A1  - Weekes, T. C.
A1  - Weinstein, A.
A1  - Weisgarber, T.
A1  - Welsing, R.
A1  - Williams, D. A.
A1  - Zitzer, B.
T1  - Discovery of TeV Gamma-Ray emission toward supernova remnant SNR G78.2+2.1
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - We report the discovery of an unidentified, extended source of very-high-energy gamma-ray emission, VER J2019+407, within the radio shell of the supernova remnant SNR G78.2+2.1, using 21.4 hr of data taken by the VERITAS gamma-ray observatory in 2009. These data confirm the preliminary indications of gamma-ray emission previously seen in a two-year (2007-2009) blind survey of the Cygnus region by VERITAS. VER J2019+407, which is detected at a post-trials significance of 7.5 standard deviations in the 2009 data, is localized to the northwestern rim of the remnant in a region of enhanced radio and X-ray emission. It has an intrinsic extent of 0 degrees.23 +/- 0 degrees.03(stat-0 degrees.02sys)(+0 degrees.04) and its spectrum is well-characterized by a differential power law (dN/dE = N-0 x (E/TeV)-Gamma) with a photon index of Gamma = 2.37 +/- 0.14(stat) +/- 0.20(sys) and a flux normalization of N-0 = 1.5 +/- 0.2(stat) +/- 0.4(sys) x 10(-12) photon TeV-1 cm(-2) s(-1). This yields an integral flux of 5.2 +/- 0.8(stat) +/- 1.4(sys) x 10(-12) photon cm(-2) s(-1) above 320 GeV, corresponding to 3.7% of the Crab Nebula flux. We consider the relationship of the TeV gamma-ray emission with the GeV gamma-ray emission seen from SNR G78.2+2.1 as well as that seen from a nearby cocoon of freshly accelerated cosmic rays. Multiple scenarios are considered as possible origins for the TeV gamma-ray emission, including hadronic particle acceleration at the SNR shock.
KW  - acceleration of particles
KW  - cosmic rays
KW  - gamma rays: general
KW  - ISM: supernova remnants
Y1  - 2013
U6  - https://doi.org/10.1088/0004-637X/770/2/93
SN  - 0004-637X
VL  - 770
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Acciari, V. A.
A1  - Aliu, E.
A1  - Arlen, T.
A1  - Aune, T.
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Bradbury, S. M.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Byrum, K.
A1  - Cannon, A.
A1  - Cesarini, A.
A1  - Ciupik, L.
A1  - Collins-Hughes, E.
A1  - Cui, W.
A1  - Dickherber, R.
A1  - Duke, C.
A1  - Errando, M.
A1  - Finley, J. P.
A1  - Finnegan, G.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Galante, N.
A1  - Gall, D.
A1  - Gillanders, G. H.
A1  - Godambe, S.
A1  - Griffin, S.
A1  - Grube, J.
A1  - Guenette, R.
A1  - Gyuk, G.
A1  - Hanna, D.
A1  - Holder, J.
A1  - Hughes, J. P.
A1  - Hui, C. M.
A1  - Humensky, T. B.
A1  - Kaaret, P.
A1  - Karlsson, N.
A1  - Kertzman, M.
A1  - Kieda, D.
A1  - Krawczynski, H.
A1  - Krennrich, F.
A1  - Lang, M. J.
A1  - LeBohec, S.
A1  - Madhavan, A. S.
A1  - Maier, G.
A1  - Majumdar, P.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Ong, R. A.
A1  - Orr, M.
A1  - Otte, A. N.
A1  - Pandel, D.
A1  - Park, N. H.
A1  - Perkins, J. S.
A1  - Pohl, Martin
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reyes, L. C.
A1  - Reynolds, P. T.
A1  - Roache, E.
A1  - Rose, H. J.
A1  - Saxon, D. B.
A1  - Schroedter, M.
A1  - Sembroski, G. H.
A1  - Senturk, G. Demet
A1  - Slane, P.
A1  - Smith, A. W.
A1  - Tesic, G.
A1  - Theiling, M.
A1  - Thibadeau, S.
A1  - Tsurusaki, K.
A1  - Varlotta, A.
A1  - Vassiliev, V. V.
A1  - Vincent, S.
A1  - Vivier, M.
A1  - Wakely, S. P.
A1  - Ward, J. E.
A1  - Weekes, T. C.
A1  - Weinstein, A.
A1  - Weisgarber, T.
A1  - Williams, D. A.
A1  - Wood, M.
A1  - Zitzer, B.
T1  - Discovery of OF TeV Gamma-Ray emission from tycho's supernova remnant
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics ; Part 2, Letters
N2  - We report the discovery of TeV gamma-ray emission from the Type Ia supernova remnant (SNR) G120.1+1.4, known as Tycho's SNR. Observations performed in the period 2008-2010 with the VERITAS ground-based gamma-ray observatory reveal weak emission coming from the direction of the remnant, compatible with a point source located at 00(h)25(m)27(s).0, +64 degrees 10'50 '' (J2000). The TeV photon spectrum measured by VERITAS can be described with a power law dN/dE = C(E/3.42 TeV)(-Gamma) with Gamma = 1.95 +/- 0.51(stat) +/- 0.30(sys) and C = (1.55 +/- 0.43(stat) +/- 0.47(sys)) x 10(-14) cm(-2) s(-1) TeV-1. The integral flux above 1 TeV corresponds to similar to 0.9% of the steady Crab Nebula emission above the same energy, making it one of the weakest sources yet detected in TeV gamma rays. We present both leptonic and hadronic models that can describe the data. The lowest magnetic field allowed in these models is similar to 80 mu G, which may be interpreted as evidence for magnetic field amplification.
KW  - gamma rays: general
KW  - ISM: individual objects (G120.1+01.4, Tycho=VER J0025+641)
Y1  - 2011
U6  - https://doi.org/10.1088/2041-8205/730/2/L20
SN  - 2041-8205
VL  - 730
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Aliu, E.
A1  - Arlen, T.
A1  - Aune, T.
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Boettcher, Markus
A1  - Bouvier, A.
A1  - Bradbury, S. M.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Cannon, A.
A1  - Cesarini, A.
A1  - Ciupik, L.
A1  - Collins-Hughes, E.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Dickherber, R.
A1  - Errando, M.
A1  - Falcone, A.
A1  - Finley, J. P.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Galante, N.
A1  - Gall, D.
A1  - Gillanders, G. H.
A1  - Godambe, S.
A1  - Griffin, S.
A1  - Grube, J.
A1  - Gyuk, G.
A1  - Hanna, D.
A1  - Holder, J.
A1  - Huan, H.
A1  - Hughes, G.
A1  - Hui, C. M.
A1  - Humensky, T. B.
A1  - Kaaret, P.
A1  - Karlsson, N.
A1  - Kertzman, M.
A1  - Kieda, D.
A1  - Krawczynski, H.
A1  - Krennrich, F.
A1  - Madhavan, A. S.
A1  - Maier, G.
A1  - Majumdar, P.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Ong, R. A.
A1  - Orr, M.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Perkins, J. S.
A1  - Pichel, A.
A1  - Pohl, Martin
A1  - Prokoph, H.
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reyes, L. C.
A1  - Reynolds, P. T.
A1  - Roache, E.
A1  - Rose, H. J.
A1  - Ruppel, J.
A1  - Saxon, D. B.
A1  - Schroedter, M.
A1  - Sembroski, G. H.
A1  - Skole, C.
A1  - Smith, A. W.
A1  - Staszak, D.
A1  - Tesic, G.
A1  - Theiling, M.
A1  - Thibadeau, S.
A1  - Tsurusaki, K.
A1  - Tyler, J.
A1  - Varlotta, A.
A1  - Vincent, S.
A1  - Vivier, M.
A1  - Wakely, S. P.
A1  - Ward, J. E.
A1  - Weinstein, A.
A1  - Weisgarber, T.
A1  - Williams, D. A.
T1  - Veritas observations of unusual extragalactic transient swift J164449.3+573451
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics ; Part 2, Letters
N2  - We report on very high energy (>100 GeV) gamma-ray observations of Swift J164449.3+573451, an unusual transient object first detected by the Swift Observatory and later detected by multiple radio, optical, and X-ray observatories. A total exposure of 28 hr was obtained on Swift J164449.3+573451 with the Very Energetic Radiation Imaging Telescope Array System ( VERITAS) during 2011 March 28-April 15. We do not detect the source and place a differential upper limit on the emission at 500 GeV during these observations of 1.4 x 10(-12) erg cm(-2) s(-1) (99% confidence level). We also present time-resolved upper limits and use a flux limit averaged over the X-ray flaring period to constrain various emission scenarios that can accommodate both the radio-through-X-ray emission detected from the source and the lack of detection by VERITAS.
KW  - accretion, accretion disks
KW  - galaxies: active
KW  - gamma rays: galaxies
KW  - radiation mechanisms: non-thermal
Y1  - 2011
U6  - https://doi.org/10.1088/2041-8205/738/2/L30
SN  - 2041-8205
VL  - 738
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
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  - Aliu, E.
A1  - Archambault, S.
A1  - Arlen, T.
A1  - Aune, T.
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Boettcher, Markus
A1  - Bouvier, A.
A1  - Bugaev, V.
A1  - Cannon, A.
A1  - Cesarini, A.
A1  - Ciupik, L.
A1  - Collins-Hughes, E.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Dickherber, R.
A1  - Dumm, J.
A1  - Errando, M.
A1  - Falcone, A.
A1  - Federici, Stefania
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Finnegan, G.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Galante, N.
A1  - Gall, D.
A1  - Godambe, S.
A1  - Griffin, S.
A1  - Grube, J.
A1  - Gyuk, G.
A1  - Hanna, D.
A1  - Holder, J.
A1  - Huan, H.
A1  - Hughes, G.
A1  - Hui, C. M.
A1  - Imran, A.
A1  - Jameil, O.
A1  - Kaaret, P.
A1  - Karlsson, N.
A1  - Kertzman, M.
A1  - Kerr, J.
A1  - Khassen, Y.
A1  - Kieda, D.
A1  - Krawczynski, H.
A1  - Krennrich, F.
A1  - Lang, M. J.
A1  - Lee, K.
A1  - Madhavan, A. S.
A1  - Majumdar, P.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nelson, T.
A1  - de Bhroithe, A. O'Faolain
A1  - Ong, R. A.
A1  - Orr, M.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Perkins, J. S.
A1  - Pichel, A.
A1  - Pohl, Martin
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reynolds, P. T.
A1  - Roache, E.
A1  - Ruppel, J.
A1  - Saxon, D. B.
A1  - Schroedter, M.
A1  - Sembroski, G. H.
A1  - Sentuerk, G. D.
A1  - Smith, A. W.
A1  - Staszak, D.
A1  - Stroh, M.
A1  - Telezhinsky, Igor O.
A1  - Tesic, G.
A1  - Theiling, M.
A1  - Thibadeau, S.
A1  - Tsurusaki, K.
A1  - Varlotta, A.
A1  - Vassiliev, V. V.
A1  - Vivier, M.
A1  - Wakely, S. P.
A1  - Ward, J. E.
A1  - Weinstein, A.
A1  - Welsing, R.
A1  - Williams, D. A.
A1  - Zitzer, B.
T1  - Multiwavelength observations of the AGN 1ES 0414+009 with veritas, FERMI-LAT, SWIFT-XRT, AND MDM
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - We present observations of the BL Lac object 1ES 0414+009 in the >200 GeV gamma-ray band by the VERITAS array of Cherenkov telescopes. 1ES 0414+009 was observed by VERITAS between 2008 January and 2011 February, resulting in 56.2 hr of good quality pointed observations. These observations resulted in a detection of 822 events from the source corresponding to a statistical significance of 6.4 standard deviations (6.4 sigma) above the background. The source flux, showing no evidence for variability, is measured as (5.2 +/- 1.1(stat) +/- 2.6(sys)) x 10(-12) photons cm(-2) s(-1) above 200 GeV, equivalent to approximately 2% of the Crab Nebula flux above this energy. The differential photon spectrum from 230 GeV to 850 GeV is well fit by a power law with a photon index of Gamma = 3.4 +/- 0.5(stat) +/- 0.3(sys) and a flux normalization of (1.6 +/- 0.3(stat) +/- 0.8(sys)) x 10(-11) photons cm(-2) s(-1) at 300 GeV. We also present multiwavelength results taken in the optical (MDM), x-ray (Swift-XRT), and GeV (Fermi-LAT) bands and use these results to construct a broadband spectral energy distribution (SED). Modeling of this SED indicates that homogenous one-zone leptonic scenarios are not adequate to describe emission from the system, with a lepto-hadronic model providing a better fit to the data.
KW  - BL Lacertae objects: individual (1ES 0414+009, ERJ0416+011)
KW  - gamma rays: galaxies
Y1  - 2012
U6  - https://doi.org/10.1088/0004-637X/755/2/118
SN  - 0004-637X
VL  - 755
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Arlen, T.
A1  - Aune, T.
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Bouvier, A.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Byrum, K.
A1  - Cannon, A.
A1  - Cesarini, A.
A1  - Ciupik, L.
A1  - Collins-Hughes, E.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Dickherber, R.
A1  - Dumm, J.
A1  - Falcone, A.
A1  - Federici, S.
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Finnegan, G.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Galante, N.
A1  - Gall, D.
A1  - Godambe, S.
A1  - Griffin, S.
A1  - Grube, J.
A1  - Gyuk, G.
A1  - Holder, J.
A1  - Huan, H.
A1  - Hughes, G.
A1  - Humensky, T. B.
A1  - Imran, A.
A1  - Kaaret, P.
A1  - Karlsson, N.
A1  - Kertzman, M.
A1  - Khassen, Y.
A1  - Kieda, D.
A1  - Krawczynski, H.
A1  - Krennrich, F.
A1  - Lee, K.
A1  - Madhavan, A. S.
A1  - Maier, G.
A1  - Majumdar, P.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nelson, T.
A1  - de Bhroithe, A. O'Faolain
A1  - Ong, R. A.
A1  - Orr, M.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Perkins, J. S.
A1  - Pohl, Martin
A1  - Prokoph, H.
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reyes, L. C.
A1  - Reynolds, P. T.
A1  - Roache, E.
A1  - Ruppel, J.
A1  - Saxon, D. B.
A1  - Schroedter, M.
A1  - Sembroski, G. H.
A1  - Skole, C.
A1  - Smith, A. W.
A1  - Telezhinsky, Igor O.
A1  - Tesic, G.
A1  - Theiling, M.
A1  - Thibadeau, S.
A1  - Tsurusaki, K.
A1  - Varlotta, A.
A1  - Vivier, M.
A1  - Wakely, S. P.
A1  - Ward, J. E.
A1  - Weinstein, A.
A1  - Welsing, R.
A1  - Williams, D. A.
A1  - Zitzer, B.
A1  - Pfrommer, C.
A1  - Pinzke, A.
T1  - Constraints on cosmic rays, magnetic fields, and dark matter fromgamma-ray observations of the coma cluster of galaxies with veritas and fermi
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - Observations of radio halos and relics in galaxy clusters indicate efficient electron acceleration. Protons should likewise be accelerated and, on account of weak energy losses, can accumulate, suggesting that clusters may also be sources of very high energy (VHE; E > 100 GeV) gamma-ray emission. We report here on VHE gamma-ray observations of the Coma galaxy cluster with the VERITAS array of imaging Cerenkov telescopes, with complementing Fermi Large Area Telescope observations at GeV energies. No significant gamma-ray emission from the Coma Cluster was detected. Integral flux upper limits at the 99% confidence level were measured to be on the order of (2-5) x 10(-8) photonsm(-2) s(-1) (VERITAS, >220 GeV) and similar to 2 x 10(-6) photonsm(-2) s(-1) (Fermi, 1-3GeV), respectively. We use the gamma-ray upper limits to constrain cosmic rays (CRs) and magnetic fields in Coma. Using an analytical approach, the CR-to-thermal pressure ratio is constrained to be < 16% from VERITAS data and <1.7% from Fermi data (averaged within the virial radius). These upper limits are starting to constrain the CR physics in self-consistent cosmological cluster simulations and cap the maximum CR acceleration efficiency at structure formation shocks to be <50%. Alternatively, this may argue for non-negligible CR transport processes such as CR streaming and diffusion into the outer cluster regions. Assuming that the radio-emitting electrons of the Coma halo result from hadronic CR interactions, the observations imply a lower limit on the central magnetic field in Coma of similar to(2-5.5) mu G, depending on the radial magnetic field profile and on the gamma-ray spectral index. Since these values are below those inferred by Faraday rotation measurements in Coma (for most of the parameter space), this renders the hadronic model a very plausible explanation of the Coma radio halo. Finally, since galaxy clusters are dark matter (DM) dominated, the VERITAS upper limits have been used to place constraints on the thermally averaged product of the total self-annihilation cross section and the relative velocity of the DM particles, <sigma nu >.
KW  - cosmic rays
KW  - dark matter
KW  - galaxies: clusters: general
KW  - galaxies: clusters: individual (Coma (ACO 1656))
KW  - gamma rays: galaxies: clusters
KW  - magnetic fields
Y1  - 2012
U6  - https://doi.org/10.1088/0004-637X/757/2/123
SN  - 0004-637X
VL  - 757
IS  - 2
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  - Aliu, E.
A1  - Arlen, T.
A1  - Aune, T.
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Bouvier, A.
A1  - Bradbury, S. M.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Byrum, K.
A1  - Cannon, A.
A1  - Cesarini, A.
A1  - Christiansen, J. L.
A1  - Ciupik, L.
A1  - Collins-Hughes, E.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Dickherber, R.
A1  - Duke, C.
A1  - Errando, M.
A1  - Falcone, A.
A1  - Finley, J. P.
A1  - Finnegan, G.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Galante, N.
A1  - Gall, D.
A1  - Gibbs, K.
A1  - Gillanders, G. H.
A1  - Godambe, S.
A1  - Griffin, S.
A1  - Grube, J.
A1  - Guenette, R.
A1  - Gyuk, G.
A1  - Hanna, D.
A1  - Holder, J.
A1  - Huan, H.
A1  - Hughes, G.
A1  - Hui, C. M.
A1  - Humensky, T. B.
A1  - Imran, A.
A1  - Kaaret, P.
A1  - Karlsson, N.
A1  - Kertzman, M.
A1  - Kieda, D.
A1  - Krawczynski, H.
A1  - Krennrich, F.
A1  - Lang, M. J.
A1  - Lyutikov, M.
A1  - Madhavan, A. S.
A1  - Maier, G.
A1  - Majumdar, P.
A1  - McArthur, S.
A1  - McCann, A.
A1  - McCutcheon, M.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nunez, P.
A1  - Ong, R. A.
A1  - Orr, M.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Perkins, J. S.
A1  - Pizlo, F.
A1  - Pohl, Martin
A1  - Prokoph, H.
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reyes, L. C.
A1  - Reynolds, P. T.
A1  - Roache, E.
A1  - Rose, H. J.
A1  - Ruppel, J.
A1  - Saxon, D. B.
A1  - Schroedter, M.
A1  - Sembroski, G. H.
A1  - Sentuerk, G. D.
A1  - Smith, A. W.
A1  - Staszak, D.
A1  - Tesic, G.
A1  - Theiling, M.
A1  - Thibadeau, S.
A1  - Tsurusaki, K.
A1  - Tyler, J.
A1  - Varlotta, A.
A1  - Vassiliev, V. V.
A1  - Vincent, S.
A1  - Vivier, M.
A1  - Wakely, S. P.
A1  - Ward, J. E.
A1  - Weekes, T. C.
A1  - Weinstein, A.
A1  - Weisgarber, T.
A1  - Williams, D. A.
A1  - Zitzer, B.
T1  - Detection of pulsed Gamma Rays Above 100 GeV from the Crab Pulsar
JF  - Science
N2  - We report the detection of pulsed gamma rays from the Crab pulsar at energies above 100 giga-electron volts (GeV) with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) array of atmospheric Cherenkov telescopes. The detection cannot be explained on the basis of current pulsar models. The photon spectrum of pulsed emission between 100 mega-electron volts and 400 GeV is described by a broken power law that is statistically preferred over a power law with an exponential cutoff. It is unlikely that the observation can be explained by invoking curvature radiation as the origin of the observed gamma rays above 100 GeV. Our findings require that these gamma rays be produced more than 10 stellar radii from the neutron star.
Y1  - 2011
U6  - https://doi.org/10.1126/science.1208192
SN  - 0036-8075
VL  - 334
IS  - 6052
SP  - 69
EP  - 72
PB  - American Assoc. for the Advancement of Science
CY  - Washington
ER  - 
TY  - JOUR
A1  - Aliu, E.
A1  - Archambault, S.
A1  - Arlen, T.
A1  - Aune, T.
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Boettcher, Markus
A1  - Bouvier, A.
A1  - Bradbury, S. M.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Byrum, K.
A1  - Cannon, A.
A1  - Cesarini, A.
A1  - Ciupik, L.
A1  - Collins-Hughes, E.
A1  - Connolly, M. P.
A1  - Coppi, P.
A1  - Cui, W.
A1  - Decerprit, G.
A1  - Dickherber, R.
A1  - Dumm, J.
A1  - Errando, Manel
A1  - Falcone, A.
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Finnegan, G.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Galante, N.
A1  - Gall, D.
A1  - Godambe, S.
A1  - Griffin, S.
A1  - Grube, J.
A1  - Gyuk, G.
A1  - Hanna, D.
A1  - Hawkins, K.
A1  - Holder, J.
A1  - Huan, H.
A1  - Hughes, G.
A1  - Humensky, T. B.
A1  - Kaaret, P.
A1  - Karlsson, N.
A1  - Kertzman, M.
A1  - Khassen, Y.
A1  - Kieda, D.
A1  - Krawczynski, H.
A1  - Krennrich, F.
A1  - Lang, M. J.
A1  - Lee, K.
A1  - Madhavan, A. S.
A1  - Maier, G.
A1  - Majumdar, P.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Moriarty, P.
A1  - Mukherjee, Reshmi
A1  - Ong, R. A.
A1  - Orr, M.
A1  - Otte, A. N.
A1  - Palma, N.
A1  - Park, N.
A1  - Perkins, J. S.
A1  - Pichel, A.
A1  - Pohl, Martin
A1  - Prokoph, H.
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reyes, L. C.
A1  - Reynolds, P. T.
A1  - Roache, E.
A1  - Rose, H. J.
A1  - Ruppel, J.
A1  - Saxon, D. B.
A1  - Schroedter, M.
A1  - Sembroski, G. H.
A1  - Sentuerk, G. D.
A1  - Smith, A. W.
A1  - Staszak, D.
A1  - Telezhinsky, Igor O.
A1  - Tesic, G.
A1  - Theiling, M.
A1  - Thibadeau, S.
A1  - Tsurusaki, K.
A1  - Varlotta, A.
A1  - Vivier, M.
A1  - Wakely, S. P.
A1  - Ward, J. E.
A1  - Weekes, T. C.
A1  - Weinstein, A.
A1  - Weisgarber, T.
A1  - Williams, D. A.
A1  - Zitzer, B.
A1  - Fortin, P.
A1  - Horan, D.
T1  - Disovery of high-energy and very high energy gamma-ray emission from the blazar RBS 0413
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - We report on the discovery of high-energy (HE; E > 0.1 GeV) and very high energy (VHE; E > 100 GeV) gamma-ray emission from the high-frequency-peaked BL Lac object RBS 0413. VERITAS, a ground-based gamma-ray observatory, detected VHE. rays from RBS 0413 with a statistical significance of 5.5 standard deviations (sigma) and a gamma-ray flux of (1.5 +/- 0.6(stat) +/- 0.7(syst)) x 10(-8) photons m(-2) s(-1) (similar to 1% of the Crab Nebula flux) above 250 GeV. The observed spectrum can be described by a power law with a photon index of 3.18 +/- 0.68(stat) +/- 0.30(syst). Contemporaneous observations with the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope detected HE gamma rays from RBS 0413 with a (stat)istical significance of more than 9 sigma, a power-law photon index of 1.57 +/- 0.12(stat-0.12sys')(+0.11) and a gamma-ray flux between 300 MeV and 300 GeV of (1.64 +/- 0.43(stat-0.22sys)(+ 0.31)) x 10(-5) photons m(-2) s(-1). We present the results from Fermi-LAT and VERITAS, including a spectral energy distribution modeling of the gamma-ray, quasi-simultaneous X-ray (Swift-XRT), ultraviolet (Swift-UVOT), and R-band optical (MDM) data. We find that, if conditions close to equipartition are required, both the combined synchrotron self-Compton/external-Compton and the lepto-hadronic models are preferred over a pure synchrotron self-Compton model.
KW  - BL Lacertae objects: individual (RBS 0413-VER J0319+187)
KW  - gamma rays: galaxies
Y1  - 2012
U6  - https://doi.org/10.1088/0004-637X/750/2/94
SN  - 0004-637X
VL  - 750
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Aliu, E.
A1  - Arlen, T.
A1  - Aune, T.
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Bouvier, A.
A1  - Bradbury, S. M.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Byrum, K.
A1  - Cannon, A.
A1  - Cesarini, A.
A1  - Ciupik, L.
A1  - Collins-Hughes, E.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Dickherber, R.
A1  - Duke, C.
A1  - Errando, M.
A1  - Falcone, A.
A1  - Finley, J. P.
A1  - Finnegan, G.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Galante, N.
A1  - Gall, D.
A1  - Godambe, S.
A1  - Griffin, S.
A1  - Grube, J.
A1  - Guenette, R.
A1  - Gyuk, G.
A1  - Hanna, D.
A1  - Holder, J.
A1  - Huan, H.
A1  - Hughes, G.
A1  - Hui, C. M.
A1  - Humensky, T. B.
A1  - Imran, A.
A1  - Kaaret, P.
A1  - Karlsson, N.
A1  - Kertzman, M.
A1  - Kieda, D.
A1  - Krawczynski, H.
A1  - Krennrich, F.
A1  - Lang, M. J.
A1  - LeBohec, S.
A1  - Madhavan, A. S.
A1  - Maier, G.
A1  - Majumdar, P.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nunez, P. D.
A1  - Ong, R. A.
A1  - Orr, M.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Perkins, J. S.
A1  - Pichel, A.
A1  - Pohl, Martin
A1  - Prokoph, H.
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reyes, L. C.
A1  - Reynolds, P. T.
A1  - Roache, E.
A1  - Rose, H. J.
A1  - Ruppel, J.
A1  - Saxon, D. B.
A1  - Schroedter, M.
A1  - Sembroski, G. H.
A1  - Sentuerk, G. D.
A1  - Skole, C.
A1  - Staszak, D.
A1  - Tesic, G.
A1  - Theiling, M.
A1  - Thibadeau, S.
A1  - Tsurusaki, K.
A1  - Tyler, J.
A1  - Varlotta, A.
A1  - Vassiliev, V. V.
A1  - Vincent, S.
A1  - Vivier, M.
A1  - Wakely, S. P.
A1  - Ward, J. E.
A1  - Weekes, T. C.
A1  - Weinstein, A.
A1  - Weisgarber, T.
A1  - Williams, D. A.
A1  - Zitzer, B.
T1  - Veritas observations of day-scale flaring of M 87 in 2010 April
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - VERITAS has been monitoring the very-high-energy (VHE; > 100 GeV) gamma-ray activity of the radio galaxy M87 since 2007. During 2008, flaring activity on a timescale of a few days was observed with a peak flux of (0.70 +/- 0.16) x 10(-11) cm(-2) s(-1) at energies above 350 GeV. In 2010 April, VERITAS detected a flare from M 87 with peak flux of (2.71 +/- 0.68) x 10(-11) cm(-2) s(-1) for E > 350 GeV. The source was observed for six consecutive nights during the flare, resulting in a total of 21 hr of good-quality data. The most rapid flux variation occurred on the trailing edge of the flare with an exponential flux decay time of 0.90(-0.15)(+0.22) days. The shortest detected exponential rise time is three times as long, at 2.87(+1.65)(-0.99) days. The quality of the data sample is such that spectral analysis can be performed for three periods: rising flux, peak flux, and falling flux. The spectra obtained are consistent with power-law forms. The spectral index at the peak of the flare is equal to 2.19 +/- 0.07. There is some indication that the spectrum is softer in the falling phase of the flare than the peak phase, with a confidence level corresponding to 3.6 standard deviations. We discuss the implications of these results for the acceleration and cooling rates of VHE electrons in M 87 and the constraints they provide on the physical size of the emitting region.
KW  - galaxies: individual (M 87, VER J1230+123)
KW  - gamma rays: galaxies
Y1  - 2012
U6  - https://doi.org/10.1088/0004-637X/746/2/141
SN  - 0004-637X
VL  - 746
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Aliu, E.
A1  - Archambault, S.
A1  - Arlen, T.
A1  - Aune, T.
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Bouvier, A.
A1  - Bradbury, S. M.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Byrum, K.
A1  - Cannon, A.
A1  - Cesarini, A.
A1  - Christiansen, J. L.
A1  - Ciupik, L.
A1  - Collins-Hughes, E.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Decerprit, G.
A1  - Dickherber, R.
A1  - Dumm, J.
A1  - Errando, M.
A1  - Falcone, A.
A1  - Feng, Q.
A1  - Ferrer, F.
A1  - Finley, J. P.
A1  - Finnegan, G.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Galante, N.
A1  - Gall, D.
A1  - Godambe, S.
A1  - Griffin, S.
A1  - Grube, J.
A1  - Gyuk, G.
A1  - Hanna, D.
A1  - Holder, J.
A1  - Huan, H.
A1  - Hughes, G.
A1  - Humensky, T. B.
A1  - Kaaret, P.
A1  - Karlsson, N.
A1  - Kertzman, M.
A1  - Khassen, Y.
A1  - Kieda, D.
A1  - Krawczynski, H.
A1  - Krennrich, F.
A1  - Lee, K.
A1  - Madhavan, A. S.
A1  - Maier, G.
A1  - Majumdar, P.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Ong, R. A.
A1  - Orr, M.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Perkins, J. S.
A1  - Pohl, Martin
A1  - Prokoph, H.
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reyes, L. C.
A1  - Reynolds, P. T.
A1  - Roache, E.
A1  - Rose, H. J.
A1  - Ruppel, J.
A1  - Saxon, D. B.
A1  - Schroedter, M.
A1  - Sembroski, G. H.
A1  - Sentuerk, G. D.
A1  - Skole, C.
A1  - Smith, A. W.
A1  - Staszak, D.
A1  - Telezhinsky, Igor O.
A1  - Tesic, G.
A1  - Theiling, M.
A1  - Thibadeau, S.
A1  - Tsurusaki, K.
A1  - Varlotta, A.
A1  - Vassiliev, V. V.
A1  - Vincent, S.
A1  - Vivier, M.
A1  - Wagner, R. G.
A1  - Wakely, S. P.
A1  - Ward, J. E.
A1  - Weekes, T. C.
A1  - Weinstein, A.
A1  - Weisgarber, T.
A1  - Williams, D. A.
A1  - Zitzer, B.
T1  - VERITAS deep observations of the dwarf spheroidal galaxy Segue 1
JF  - Physical review : D, Particles, fields, gravitation, and cosmology
N2  - The VERITAS array of Cherenkov telescopes has carried out a deep observational program on the nearby dwarf spheroidal galaxy Segue 1. We report on the results of nearly 48 hours of good quality selected data, taken between January 2010 and May 2011. No significant gamma-ray emission is detected at the nominal position of Segue 1, and upper limits on the integrated flux are derived. According to recent studies, Segue 1 is the most dark matter-dominated dwarf spheroidal galaxy currently known. We derive stringent bounds on various annihilating and decaying dark matter particle models. The upper limits on the velocity-weighted annihilation cross-section are <sigma upsilon >(95%) (CL) less than or similar to 10(-23) cm(3) s(-1), improving our limits from previous observations of dwarf spheroidal galaxies by at least a factor of 2 for dark matter particle masses m(chi) greater than or similar to 300 GeV. The lower limits on the decay lifetime are at the level of tau(95%) (CL) greater than or similar to 10(24) s. Finally, we address the interpretation of the cosmic ray lepton anomalies measured by ATIC and PAMELA in terms of dark matter annihilation, and show that the VERITAS observations of Segue 1 disfavor such a scenario.
Y1  - 2012
U6  - https://doi.org/10.1103/PhysRevD.85.062001
SN  - 1550-7998
VL  - 85
IS  - 6
PB  - American Physical Society
CY  - College Park
ER  - 
TY  - JOUR
A1  - Acciari, V. A.
A1  - Aliu, E.
A1  - Arlen, T.
A1  - Aune, T.
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Bradbury, S. M.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Byrum, K.
A1  - Cannon, A.
A1  - Cesarini, A.
A1  - Ciupik, L.
A1  - Collins-Hughes, E.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Dickherber, R.
A1  - Duke, C.
A1  - Errando, M.
A1  - Falcone, A.
A1  - Finley, J. P.
A1  - Finnegan, G.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Galante, N.
A1  - Gall, D.
A1  - Gillanders, G. H.
A1  - Godambe, S.
A1  - Griffin, S.
A1  - Grube, J.
A1  - Guenette, R.
A1  - Gyuk, G.
A1  - Hanna, D.
A1  - Holder, J.
A1  - Hughes, G.
A1  - Hui, C. M.
A1  - Humensky, T. B.
A1  - Kaaret, P.
A1  - Karlsson, N.
A1  - Kertzman, M.
A1  - Kieda, D.
A1  - Krawczynski, H.
A1  - Krennrich, F.
A1  - Lang, M. J.
A1  - LeBohec, S.
A1  - Maier, G.
A1  - Majumdar, P.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Ong, R. A.
A1  - Orr, M.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Perkins, J. S.
A1  - Pohl, Martin
A1  - Prokoph, H.
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reyes, L. C.
A1  - Reynolds, P. T.
A1  - Roache, E.
A1  - Rose, H. J.
A1  - Ruppel, J.
A1  - Saxon, D. B.
A1  - Schroedter, M.
A1  - Sembroski, G. H.
A1  - Senturk, G. D.
A1  - Smith, A. W.
A1  - Staszak, D.
A1  - Tesic, G.
A1  - Theiling, M.
A1  - Thibadeau, S.
A1  - Tsurusaki, K.
A1  - Varlotta, A.
A1  - Vassiliev, V. V.
A1  - Vincent, S.
A1  - Vivier, M.
A1  - Wakely, S. P.
A1  - Ward, J. E.
A1  - Weekes, T. C.
A1  - Weinstein, A.
A1  - Weisgarber, T.
A1  - Williams, D. A.
A1  - Zitzer, B.
T1  - VERITAS OBSERVATIONS OF THE TeV BINARY LS I+61 degrees 303 DURING 2008-2010
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - We present the results of observations of the TeV binary LS I + 61 degrees 303 with the VERITAS telescope array between 2008 and 2010, at energies above 300 GeV. In the past, both ground-based gamma-ray telescopes VERITAS and MAGIC have reported detections of TeV emission near the apastron phases of the binary orbit. The observations presented here show no strong evidence for TeV emission during these orbital phases; however, during observations taken in late 2010, significant emission was detected from the source close to the phase of superior conjunction (much closer to periastron passage) at a 5.6 standard deviation (5.6 sigma) post-trials significance. In total, between 2008 October and 2010 December a total exposure of 64.5 hr was accumulated with VERITAS on LS I + 61 degrees 303, resulting in an excess at the 3.3 sigma significance level for constant emission over the entire integrated data set. The flux upper limits derived for emission during the previously reliably active TeV phases (i.e., close to apastron) are less than 5% of the Crab Nebula flux in the same energy range. This result stands in apparent contrast to previous observations by both MAGIC and VERITAS which detected the source during these phases at 10% of the Crab Nebula flux. During the two year span of observations, a large amount of X-ray data were also accrued on LS I + 61 degrees 303 by the Swift X-ray Telescope and the Rossi X-ray Timing Explorer Proportional Counter Array. We find no evidence for a correlation between emission in the X-ray and TeV regimes during 20 directly overlapping observations. We also comment on data obtained contemporaneously by the Fermi Large Area Telescope.
KW  - binaries: general
KW  - gamma rays: general
KW  - X-rays: binaries
Y1  - 2011
U6  - https://doi.org/10.1088/0004-637X/738/1/3
SN  - 0004-637X
VL  - 738
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  - Babie, 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  - Carosi, R.
A1  - Carosi, A.
A1  - Chatterjee, A.
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  - 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-Barra, 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  - Godinovie, N.
A1  - Gora, D.
A1  - Griffiths, S.
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  - Hughes, G.
A1  - Ishio, K.
A1  - Konno, Y.
A1  - Kubo, H.
A1  - Kushida, J.
A1  - Kuvezdie, D.
A1  - Lelas, D.
A1  - Lindfors, E.
A1  - Lombardi, S.
A1  - Longo, F.
A1  - Lopez, M.
A1  - Lopez-Oramas, A.
A1  - Majumdar, P.
A1  - Makariev, M.
A1  - Maneva, G.
A1  - Manganaro, M.
A1  - Mannheim, K.
A1  - Maraschi, L.
A1  - Mariotti, M.
A1  - Martinez, M.
A1  - Mazin, D.
A1  - Menzel, U.
A1  - Minev, M.
A1  - Mirzoyan, R.
A1  - Moralejo, A.
A1  - Moreno, V.
A1  - Moretti, E.
A1  - Munar-Adrover, P.
A1  - Neustroev, V.
A1  - Niedzwiecki, A.
A1  - Rosillo, M. Nievas
A1  - Nilsson, K.
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  - Paredes-Fortuny, X.
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  - Rhode, W.
A1  - Riti, M.
A1  - Rico, J.
A1  - Saito, T.
A1  - Satalecka, K.
A1  - Schroeder, S.
A1  - Schweizer, T.
A1  - Shore, S. N.
A1  - Sillanpaa, A.
A1  - Sitarek, J.
A1  - Sobczynskall, D.
A1  - Stamerra, A.
A1  - Strzys, M.
A1  - Surie, T.
A1  - Takalo, L.
A1  - Tavecchio, F.
A1  - Temnikov, P.
A1  - Terzie, T.
A1  - Tescaro, D.
A1  - Teshima, M.
A1  - Torres, D. F.
A1  - Torres-Alla, N.
A1  - Treves, A.
A1  - Vanzo, G.
A1  - Acosta, M. Vazquez
A1  - Vovk, I.
A1  - Ward, J. E.
A1  - Will, M.
A1  - Wu, M. H.
A1  - Zarie, D.
A1  - Abdalla, Hassan E.
A1  - Abramowski, A.
A1  - Aharonian, Felix A.
A1  - Benkhali, F. Ait
A1  - Akhperjanian, A. G.
A1  - Andersson, T.
A1  - Angüner, Ekrem Oǧuzhan
A1  - Arakawa, M.
A1  - Arrieta, M.
A1  - Aubert, P.
A1  - Backes, M.
A1  - Balzer, A.
A1  - Barnard, M.
A1  - Becherini, Y.
A1  - Tjus, J. Becker
A1  - Berge, D.
A1  - Bernhard, S.
A1  - Bernlohr, K.
A1  - Blackwell, R.
A1  - Bottcher, M.
A1  - Boisson, C.
A1  - Bolmont, J.
A1  - Bordas, Pol
A1  - Bregeon, J.
A1  - Brun, F.
A1  - Brun, P.
A1  - Bryan, M.
A1  - Btichele, M.
A1  - Bulik, T.
A1  - Capasso, M.
A1  - Carr, J.
A1  - Casanova, Sabrina
A1  - Cerruti, M.
A1  - Chakraborty, N.
A1  - Chalme-Calvet, R.
A1  - Chaves, R. C. G.
A1  - Chen, A.
A1  - Chevalier, J.
A1  - Chretien, M.
A1  - Coffaro, M.
A1  - Colafrancesco, S.
A1  - Cologna, G.
A1  - Condon, B.
A1  - Conrad, J.
A1  - Cui, Y.
A1  - Davids, I. D.
A1  - Decock, J.
A1  - Degrange, B.
A1  - Dei, C.
A1  - Devin, J.
A1  - Dewilt, P.
A1  - Dirson, L.
A1  - Djannati-Atai, A.
A1  - Domainko, W.
A1  - Donath, A.
A1  - Dutson, K.
A1  - Dyks, J.
A1  - Edwards, T.
A1  - Egberts, Kathrin
A1  - Eger, P.
A1  - Ernenwein, J. -P.
A1  - Eschbach, S.
A1  - Farnier, C.
A1  - Fegan, S.
A1  - Fernandes, M. V.
A1  - Fiasson, A.
A1  - Fontaine, G.
A1  - Forster, A.
A1  - Funk, S.
A1  - Ftifiling, M.
A1  - Gabici, S.
A1  - Gajdus, M.
A1  - Gallant, Y. A.
A1  - Garrigoux, T.
A1  - Giavitto, G.
A1  - Giebels, B.
A1  - Glicenstein, J. F.
A1  - Gottschal, D.
A1  - Goya, A.
A1  - Grondin, M. -H.
A1  - Hahn, J.
A1  - Haupt, M.
A1  - Hawkes, J.
A1  - Heinzelmann, G.
A1  - Henri, G.
A1  - Hermann, G.
A1  - Hervet, O.
A1  - Hinton, J. A.
A1  - Hofmann, W.
A1  - Hoischen, Clemens
A1  - Holler, M.
A1  - Horns, D.
A1  - Ivascenko, A.
A1  - Iwasaki, H.
A1  - Jacholkowska, A.
A1  - Jamrozy, M.
A1  - Janiak, M.
A1  - Jankowsky, D.
A1  - Jankowsky, F.
A1  - Jingo, M.
A1  - Jogler, T.
A1  - Jouvin, L.
A1  - Jung-Richardt, I.
A1  - Kastendieck, M. A.
A1  - Katarzyfiski, K.
A1  - Katsuragawa, M.
A1  - Katz, U.
A1  - Kerszberg, D.
A1  - Khangulyan, D.
A1  - Khelifi, B.
A1  - Kieffer, M.
A1  - King, J.
A1  - Klepser, S.
A1  - Klochkov, D.
A1  - Kluiniak, W.
A1  - Kolitzus, D.
A1  - Komin, Nu.
A1  - Kosack, K.
A1  - Krakau, S.
A1  - Kraus, M.
A1  - Krtiger, P. P.
A1  - Laffon, H.
A1  - Lamanna, G.
A1  - Lau, J.
A1  - Lees, J. -P.
A1  - Lefaucheur, J.
A1  - Lefranc, V.
A1  - Lemiere, A.
A1  - Lemoine-Goumard, M.
A1  - Lenain, J. -P.
A1  - Leser, Eva
A1  - Lohse, T.
A1  - Lorentz, M.
A1  - Liu, R.
A1  - Lopez-Coto, R.
A1  - Lypova, I.
A1  - Marandon, V.
A1  - Marcowith, Alexandre
A1  - Mariaud, C.
A1  - Marx, R.
A1  - Maurin, G.
A1  - Maxted, N.
A1  - Mayer, M.
A1  - Meintjes, P. J.
A1  - Meyer, M.
A1  - Mitche, A. M. W.
A1  - Moderski, R.
A1  - Mohamed, M.
A1  - Mohrmann, L.
A1  - Mora, K.
A1  - Moulin, Emmanuel
A1  - Murach, T.
A1  - Nakashima, S.
A1  - De Naurois, M.
A1  - Niederwanger, F.
A1  - Niemiec, J.
A1  - Oakes, L.
A1  - Odaka, H.
A1  - Ott, S.
A1  - Ohm, S.
A1  - Ostrowski, M.
A1  - Oya, I.
A1  - Padovani, M.
A1  - Panter, M.
A1  - Parsons, R. D.
A1  - Pekeur, N. W.
A1  - Pelletier, G.
A1  - Perennes, C.
A1  - Petrucci, P. -O.
A1  - Peyaud, B.
A1  - Pie, Q.
A1  - Pita, S.
A1  - Poon, H.
A1  - Prokhorov, D.
A1  - Prokoph, H.
A1  - Ptffilhofer, G.
A1  - Punch, M.
A1  - Quirrenbach, A.
A1  - Raab, S.
A1  - Reimer, A.
A1  - Reimer, O.
A1  - Renaud, M.
A1  - De Los Reyes, R.
A1  - Richter, S.
A1  - Rieger, F.
A1  - Romoli, C.
A1  - Rowell, G.
A1  - Rudak, B.
A1  - Rulten, C. B.
A1  - Safi-Harb, S.
A1  - Sahakian, V.
A1  - Saito, S.
A1  - Salek, D.
A1  - Sanchez, D. A.
A1  - Santangelo, Andrea
A1  - Sasaki, M.
A1  - Schlickeiser, R.
A1  - Schtissler, F.
A1  - Schulz, A.
A1  - Schwanke, U.
A1  - Schwemmer, S.
A1  - Seglar-Arroyo, M.
A1  - Settimo, M.
A1  - Seyffert, A. S.
A1  - Shafi, N.
A1  - Shilon, I.
A1  - Simoni, R.
A1  - So, H.
A1  - Spanier, F.
A1  - Spengler, G.
A1  - Spies, F.
A1  - Stawarz, L.
A1  - Steenkamp, R.
A1  - Stegmann, Christian
A1  - Stycz, K.
A1  - Sushch, I.
A1  - Takahashi, T.
A1  - Tavernet, J. -P.
A1  - Tavernier, T.
A1  - Taylor, A. M.
A1  - Terrier, R.
A1  - Tibaldo, L.
A1  - Tiziani, D.
A1  - Tluczykont, M.
A1  - Trichard, C.
A1  - Tsuji, N.
A1  - Tuffs, R.
A1  - Uchiyama, Y.
A1  - Van der Walt, D. J.
A1  - Van Eldik, C.
A1  - Van Rensburg, C.
A1  - Van Soelen, B.
A1  - Vasileiadis, G.
A1  - Veh, J.
A1  - Venter, C.
A1  - Viana, A.
A1  - Vincent, P.
A1  - Vink, J.
A1  - Voisin, F.
A1  - Vok, H. J.
A1  - Vuillaume, T.
A1  - Wadiasingh, Z.
A1  - Wagner, S. J.
A1  - Wagner, P.
A1  - Wagner, R. M.
A1  - White, R.
A1  - Wierzcholska, A.
A1  - Willmann, P.
A1  - Wornlein, A.
A1  - Wouters, D.
A1  - Yang, R.
A1  - Zabalza, V.
A1  - Zaborov, D.
A1  - Zacharias, M.
A1  - Zanin, R.
A1  - Zdziarski, A. A.
A1  - Zech, Alraune
A1  - Zefi, F.
A1  - Ziegler, A.
A1  - Zywuckan, N.
T1  - Constraints on particle acceleration in SS433/W50 from MAGIC and HESS observations
JF  - Astronomy and astrophysics : an international weekly journal
N2  - Context. The large jet kinetic power and non-thermal processes occurring in the microquasar SS 433 make this source a good candidate for a very high-energy (VHE) gamma-ray emitter. Gamma-ray fluxes above the sensitivity limits of current Cherenkov telescopes have been predicted for both the central X-ray binary system and the interaction regions of SS 433 jets with the surrounding W50 nebula. Non-thermal emission at lower energies has been previously reported, indicating that efficient particle acceleration is taking place in the system. Aims. We explore the capability of SS 433 to emit VHE gamma rays during periods in which the expected flux attenuation due to periodic eclipses (P-orb similar to 13.1 days) and precession of the circumstellar disk (P-pre similar to 162 days) periodically covering the central binary system is expected to be at its minimum. The eastern and western SS 433/W50 interaction regions are also examined using the whole data set available. We aim to constrain some theoretical models previously developed for this system with our observations. Methods. We made use of dedicated observations from the Major Atmospheric Gamma Imaging Cherenkov telescopes (MAGIC) and High Energy Spectroscopic System (H.E.S.S.) of SS 433 taken from 2006 to 2011. These observation were combined for the first time and accounted for a total effective observation time of 16.5 h, which were scheduled considering the expected phases of minimum absorption of the putative VHE emission. Gamma-ray attenuation does not affect the jet/medium interaction regions. In this case, the analysis of a larger data set amounting to similar to 40-80 h, depending on the region, was employed. Results. No evidence of VHE gamma-ray emission either from the central binary system or from the eastern/western interaction regions was found. Upper limits were computed for the combined data set. Differential fluxes from the central system are found to be less than or similar to 10(-12)-10(-13) TeV-1 cm(-2) s(-1) in an energy interval ranging from similar to few x 100 GeV to similar to few TeV. Integral flux limits down to similar to 10(-12)-10(-13) ph cm(-2) s(-1) and similar to 10(-13)-10(-14) ph cm(-2) s(-1) are obtained at 300 and 800 GeV, respectively. Our results are used to place constraints on the particle acceleration fraction at the inner jet regions and on the physics of the jet/medium interactions. Conclusions. Our findings suggest that the fraction of the jet kinetic power that is transferred to relativistic protons must be relatively small in SS 433, q(p) <= 2.5 x 10(-5), to explain the lack of TeV and neutrino emission from the central system. At the SS 433/W50 interface, the presence of magnetic fields greater than or similar to 10 mu G is derived assuming a synchrotron origin for the observed X-ray emission. This also implies the presence of high-energy electrons with E-e up to 50 TeV, preventing an efficient production of gamma-ray fluxes in these interaction regions.
KW  - gamma rays: general
KW  - stars: black holes
KW  - X-rays: binaries
KW  - ISM: jets and outflows
Y1  - 2018
U6  - https://doi.org/10.1051/0004-6361/201731169
SN  - 1432-0746
VL  - 612
PB  - EDP Sciences
CY  - Les Ulis
ER  -