Now showing items 108-127 of 135

    • Ultra-sensitive label free imaging below the resolution limit 

      Alexandrov, Sergey; McGrath, James; Sheppard, Colin J. R.; Boccafoschi, Francesca; Giannini, Cinzia; Sibillano, Teresa; Subhash, Hrebesh; Hogan, Josh; Leahy, James J. (SPIE (Society of Photo-optical Instrumentation Engineers) Digital Library, 2019-02-02)
      Almost all known nanoscopy methods rely upon the contrast created by fluorescent labels attached to the object of interest. This causes limitations on their applicability to in vivo imaging. A new label-free spectral ...
    • Understanding the changes of cone reflectance in adaptive optics flood illumination retinal images over three years 

      Mariotti, Letizia; Devaney, Nicholas; Lombardo, Giuseppe; Lombardo, Marco (Optical Society of America, 2016)
      Although there is increasing interest in the investigation of cone reflectance variability, little is understood about its characteristics over long time scales. Cone detection and its automation is now becoming a fundamental ...
    • 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 ...
    • Using the Agile software development lifecycle to develop a standalone application for generating colour magnitude diagrams 

      Fitzgerald, K.; Browne, Lisa-Marie; Butler, Ray F. (Elsevier, 2019-05-11)
      Virtual observatories allow the means by which an astronomer is able to discover, access, and process data seamlessly, regardless of its physical location. However, steep learning curves are often required to become ...
    • Validation of the inhalable dust algorithm of the Advanced REACH Tool using a dataset from the pharmaceutical industry 

      Mc Donnell, Patricia E.; Coggins, Marie (RSC, 2011-05-04)
      As it is often difficult to obtain sufficient numbers of measurements to adequately characterise exposure levels, occupational exposure models may be useful tools in the exposure assessment process. This study aims to ...
    • 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 Observations of the Unusual Extragalactic Transient Swift J164449.3+573451 

      Gillanders, Gary (2011)
      We report on very-high-energy ($>$100 GeV) gamma-ray observations of Swift J164449.3+573451, an unusual transient object first detected by the {\it Swift} Observatory and later detected by multiple radio, optical and ...
    • 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 ...
    • Very High Energy Observations of Gamma-Ray Burst Locations with the Whipple Telescope 

      Lang, Mark; Gillanders, Gary (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 ...
    • Very High Energy Observations of Gamma-Ray Burst Locations with the Whipple Telescope 

      Lang, Mark; Gillanders, Gary (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 ...