Now showing items 41-60 of 63

  • A Search for Pulsed TeV Gamma Ray Emission from the Crab Pulsar 

    Lang, Mark; Gillanders, Gary (1999)
    We present the results of a search for pulsed TeV emission from the Crab pulsar using the Whipple Observatory's 10m gamma-ray telescope. The direction of the Crab pulsar was observed for a total of 73.4 hours between 1994 ...
  • Search for Pulsed TeV Gamma-ray Emission from the Crab Pulsar 

    Lang, Mark; Gillanders, Gary; Lessard, R. W.; Bond, I. H.; Bradbury, S. M.; Buckley, J. H.; Burdett, A. M.; Carter-Lewis, D. A.; Catanese, M.; Cawley, M. F.; D'Vali, M.; Fegan, D. J.; Finley, J. P.; Gaidos, J. A.; Gillanders, G. H.; Hall, T.; Hillas, A. M.; Krennrich, F.; Lang, M. J.; Masterson, C.; Moriarty, P.; Quinn, J.; Rose, H. J.; Samuelson, F. W.; Sembroski, G. H.; Srinivasan, R.; Vassiliev, V. V.; Weekes, T. C. (1999)
    We present the results of a search for pulsed TeV emission from the Crab pulsar using the Whipple Observatory's 10 m gamma-ray telescope. The direction of the Crab pulsar was observed for a total of 73.4 hours between 1994 ...
  • Search for Pulsed TeV Gamma-ray Emission from the Crab Pulsar 

    Lang, Mark; Gillanders, Gary (1999)
    We present the results of a search for pulsed TeV emission from the Crab pulsar using the Whipple Observatory's 10 m gamma-ray telescope. The direction of the Crab pulsar was observed for a total of 73.4 hours between 1994 ...
  • Simultaneous Multiwavelength Observations of Markarian 421 During Outburst 

    Lang, Mark (2009)
    We report on the results of two coordinated multiwavelength campaigns that focused on the blazar Markarian 421 during its 2006 and 2008 outbursts. These campaigns obtained UV and X-ray data using the XMM-Newton satellite, ...
  • Status of the VERITAS Observatory 

    Lang, Mark; Gillanders, Gary (2008)
    VERITAS, an Imaging Atmospheric Cherenkov Telescope (IACT) system for gammma-ray astronomy in the GeV-TeV range, has recently completed its first season of observations with a full array of four telescopes. A number of ...
  • TeV and Multi-wavelength Observations of Mrk 421 in 2006-2008 

    Lang, Mark; Gillanders, Gary (2011)
    We report on TeV gamma-ray observations of the blazar Mrk 421 (redshift of 0.031) with the VERITAS observatory and the Whipple 10m Cherenkov telescope. The excellent sensitivity of VERITAS allowed us to sample the TeV ...
  • TeV Gamma-Ray Observations of the Perseus and Abell 2029 Galaxy Clusters 

    Lang, Mark; Gillanders, Gary (2006)
    Galaxy clusters might be sources of TeV gamma rays emitted by high-energy protons and electrons accelerated by large scale structure formation shocks, galactic winds, or active galactic nuclei. Furthermore, gamma rays may ...
  • Unprecedented study of the broadband emission of Mrk 421 during flaring activity in March 2010 

    Moriarty, P.; Gillanders, Gary; Lang, Mark (EDP Sciences, 2015-05-27)
    Context. Because of its proximity, Mrk 421 is one of the best sources on which to study the nature of BL Lac objects. Its proximity allows us to characterize its broadband spectral energy distribution (SED). Aims. The ...
  • VERITAS 2008 - 2009 monitoring of the variable gamma-ray source M87 

    Lang, Mark; Gillanders, Gary (2010)
    M87 is a nearby radio galaxy that is detected at energies ranging from radio to VHE gamma-rays. Its proximity and its jet, misaligned from our line-of-sight, enable detailed morphological studies and extensive modeling at ...
  • VERITAS detection of gamma-ray flaring activity from the BL LAC object 1ES 1727+502 during bright moonlight observations 

    Connolly, M.P.; Gillanders, Gary; Moriarty, P.; Lang, Mark (American Astronomical Society, 2015-08-01)
    During moonlit nights, observations with ground-based Cherenkov telescopes at very high energies (VHEs, E > 100 GeV) are constrained since the photomultiplier tubes (PMTs) in the telescope camera are extremely sensitive ...
  • VERITAS Discovery of >200GeV Gamma-ray Emission from the Intermediate-frequency-peaked BL Lac Object W Comae 

    Lang, Mark; Gillanders, Gary (2008)
    We report the detection of very high-energy gamma-ray emission from the intermediate-frequency-peaked BL Lacertae object W Comae (z=0.102) by VERITAS. The source was observed between January and April 2008. A strong outburst ...
  • VERITAS Observations of a Very High Energy Gamma-ray Flare from the Blazar 3C 66A 

    Lang, Mark; Gillanders, Gary (2009)
    The intermediate-frequency peaked BL Lacertae (IBL) object 3C 66A is detected during 2007 - 2008 in VHE (very high energy: E > 100 GeV) gamma-rays with the VERITAS stereoscopic array of imaging atmospheric Cherenkov ...
  • VERITAS observations of the BL Lac object PG 1553+113 

    Connolly, M.P.; Gillanders, Gary; Moriarty, P.; Lang, Mark (American Astronomical Society, 2015-01-20)
    We present results from VERITAS observations of the BL Lac object PG 1553+113 spanning the years 2010, 2011, and 2012. The time-averaged spectrum, measured between 160 and 560 GeV, is well described by a power law with a ...
  • VERITAS observations of the BL Lac 1ES 1218+304 

    Lang, Mark; Gillanders, Gary (2009)
    The VERITAS collaboration reports the detection of very-high-energy (VHE) gamma-ray emission from the high-frequency-peaked BL Lac object 1ES 1218+304 located at a redshift of z=0.182. A gamma-ray signal was detected with ...
  • VERITAS Observations of the gamma-Ray Binary LS I +61 303 

    Lang, Mark; Gillanders, Gary (2008)
    LS I +61 303 is one of only a few high-mass X-ray binaries currently detected at high significance in very high energy gamma-rays. The system was observed over several orbital cycles (between September 2006 and February ...
  • VERITAS Observations of the TeV Binary LS I +61 303 During 2008-2010 

    Lang, Mark; Gillanders, Gary (2011)
    We present the results of observations of the TeV binary LS I +61 303 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 ...
  • VERITAS Upper Limit on the VHE Emission from the Radio Galaxy NGC 1275 

    Lang, Mark; Gillanders, Gary (2009)
    The recent detection by the Fermi gamma-ray space telescope of high-energy gamma-rays from the radio galaxy NGC 1275 makes the observation of the very high energy (VHE: E > 100 GeV) part of its broadband spectrum ...
  • VERITAS: Status and Highlights 

    Lang, Mark; Gillanders, Gary (2011)
    The VERITAS telescope array has been operating smoothly since 2007, and has detected gamma-ray emission above 100 GeV from 40 astrophysical sources. These include blazars, pulsar wind nebulae, supernova remnants, gamma-ray ...
  • A Very High Energy Gamma-Ray Spectrum of 1ES 2344+514 

    Lang, Mark; Gillanders, Gary (2005)
    The BL Lacertae (BL Lac) object 1ES 2344+514 (1ES 2344), at a redshift of 0.044, was discovered as a source of very high energy (VHE) gamma rays by the Whipple Collaboration in 1995 \citep{2344Catanese98}. This detection ...
  • Very High Energy Observations of Gamma-Ray Burst Locations with the Whipple Telescope 

    Lang, Mark; Gillanders, Gary; Horan, D.; Atkins, R. W.; Badran, H. M.; Blaylock, G.; Bradbury, S. M.; Buckley, J. H.; Byrum, K. L.; Celik, O.; Chow, Y. C. K.; Cogan, P.; Cui, W.; Daniel, M. K.; Perez, I. de la Calle; Dowdall, C.; Falcone, A. D.; Fegan, D. J.; Fegan, S. J.; Finley, J. P.; Fortin, P.; Fortson, L. F.; Gillanders, G. H.; Grube, J.; Gutierrez, K. J.; Hall, J.; Hanna, D.; Holder, J.; Hughes, S. B.; Humensky, T. B.; Kenny, G. E.; Kertzman, M.; Kieda, D. B.; Kildea, J.; Krawczynski, H.; Krennrich, F.; Lang, M. J.; LeBohec, S.; Maier, G.; Moriarty, P.; Nagai, T.; Ong, R. A.; Perkins, J. S.; Petry, D.; Quinn, J.; Quinn, M.; Ragan, K.; Reynolds, P. T.; Rose, H. J.; Schroedter, M.; Sembroski, G. H.; Steele, D.; Swordy, S. P.; Toner, J. A.; Valcarcel, L.; Vassiliev, V. V.; Wagner, R. G.; Wakely, S. P.; Weekes, T. C.; White, R. J.; Williams, D. A. (2007)
    Gamma-ray burst (GRB) observations at very high energies (VHE, E > 100 GeV) can impose tight constraints on some GRB emission models. Many GRB afterglow models predict a VHE component similar to that seen in blazars and ...