Now showing items 87-106 of 157

    • Observation of Extended VHE Emission from the Supernova Remnant IC 443 with VERITAS 

      Lang, Mark; Gillanders, Gary (2009)
      We present evidence that the very-high-energy (VHE, E > 100 GeV) gamma-ray emission coincident with the supernova remnant IC 443 is extended. IC 443 contains one of the best-studied sites of supernova remnant/molecular ...
    • Observation of gamma-ray emission from the galaxy M87 above 250 GeV with VERITAS 

      Lang, Mark; Gillanders, Gary (2008)
      The multiwavelength observation of the nearby radio galaxy M87 provides a unique opportunity to study in detail processes occurring in Active Galactic Nuclei from radio waves to TeV gamma-rays. Here we report the detection ...
    • Observations of the shell-type SNR Cassiopeia A at TeV energies with VERITAS 

      Lang, Mark; Gillanders, Gary (2010)
      We report on observations of very high-energy gamma rays from the shell-type supernova remnant Cassiopeia A with the VERITAS stereoscopic array of four imaging atmospheric Cherenkov telescopes in Arizona. The total exposure ...
    • Observations of the Unidentified TeV Gamma-Ray Source TeV J2032+4130 with the Whipple Observatory 10 m Telescope 

      Lang, Mark; Gillanders, Gary (2006)
      We report on observations of the sky region around the unidentified TeV gamma-ray source TeV J2032+4130 carried out with the Whipple Observatory 10 m atmospheric Cherenkov telescope for a total of 65.5 hrs between 2003 and ...
    • Occupational exposures in an equestrian centre to respirable dust and respirable crystalline silica 

      Bulfin, Kathleen; Cowie, Hilary; Galea, Karen S.; Connolly, Alison; Coggins, Marie Ann (MDPI, 2019-09-03)
      Abstract: Sand-based products are regularly used as footing material on indoor equestrian arenas, creating a potential occupational exposure risk for respirable crystalline silica (RCS) for equestrian workers training and ...
    • Optical Observations of PSR J0205+6449 

      Shearer, Andrew (2008)
      PSR J0205+6449 is a X-ray and radio pulsar in supernova remnant 3C 58. We report on observations of the central region of 3C 58 using the 4.2-m William Herschel Telescope with the intention of identifying the optical ...
    • Optical pulsations from the anomalous X-ray pulsar 1E 1048.1-5937 

      Shearer, Andrew (2009)
      We present high-speed optical photometry of the anomalous X-ray pulsar 1E 1048.1-5937 obtained with ULTRACAM on the 8.2-m Very Large Telescope in June 2007. We detect 1E 1048.1-5937 at a magnitude of i'=25.3+/-0.2, consistent ...
    • Optical system of aplanatic telescope with a 100 m spherical primary mirror 

      Druzhin, Vladislav V.; Puryaev, Daniil T.; Goncharov, Alexander V. (Society of Photo-optical Instrumentation Engineers, 2022-06-30)
      We propose an optical system of an extremely large telescope for ground-based or planetary use. The system comprises a segmented spherical mirror with a diameter of 100 m and f-number of f/1. There are three annular zones ...
    • Performance analysis of cone detection algorithms 

      Mariotti, Letizia; Devaney, Nicholas (Optical Society of America, 2015-04-01)
      Many algorithms have been proposed to help clinicians evaluate cone density and spacing, as these may be related to the onset of retinal diseases. However, there has been no rigorous comparison of the performance of these ...
    • Performance review of multiple reference versus time domain optical coherence tomography 

      Neuhaus, Kai; McNamara, Paul M.; Alexandrov, Sergey; O'Gorman, Seán; Hogan, Josh; Wilson, Carol; Leahy, Martin J. (IEEE, 2018-04-19)
      We present a detailed characterization of noise sources in multiple reference optical coherence tomography (MR-OCT) compared to time-domain OCT (TD-OCT). The noise characteristics were modeled based on the TD-OCT noise ...
    • Phasing-out of legacy brominated flame retardants: The UNEP Stockholm Convention and other legislative action worldwide 

      Sharkey, Martin; Harrad, Stuart; Abou-Elwafa Abdallah, Mohamed; Drage, Daniel S.; Berresheim, Harald (Elsevier, 2020-08-18)
      Due to their toxicity and persistence, several families of brominated flame retardants (BFRs) have been listed as persistent organic pollutants (POPs) in the Stockholm Convention, a multilateral treaty overseen by the ...
    • Portable X-ray fluorescence for the detection of POP-BFRs in waste plastics 

      Sharkey, Martin; Abdallah, Mohamed Abou-Elwafa; Drage, Daniel S; Harrad, Stuart; Berresheim, Harald (Elsevier, 2018-05-26)
      The purpose of this study was to establish the efficacy of portable X-ray fluorescence (XRF) instrumentation as a screening tool for a variety of end of life plastics which may contain excess amounts of brominated flame ...
    • Pulse variation of the optical emission of Crab pulsar 

      Shearer, Andrew (2007)
      The stability of the optical pulse of the Crab pulsar is analyzed based on the 1 $\mu$s resolution observations with the Russian 6-meter and William Hershel telescopes equipped with different photon-counting detectors. The ...
    • Radio Imaging of the Very-High-Energy Gamma-Ray Emission Region in the Central Engine of a Radio Galaxy 

      Lang, Mark (2009)
      The accretion of matter onto a massive black hole is believed to feed the relativistic plasma jets found in many active galactic nuclei (AGN). Although some AGN accelerate particles to energies exceeding 10^12 electron ...
    • Real-time quantitative visualization of 3D structural information 

      Alexandrov, Sergey; Uttam, Shikhar; Bista, Rajan K.; Zhao, Chengquan; Liu, Yang (Optica, 2012)
      We demonstrate a novel approach for the real time visualization and quantification of the 3D spatial frequencies in an image domain. Our approach is based on the spectral encoding of spatial frequency principle and permits ...
    • A recent change in the optical and gamma ray polarization of the Crab nebula and pulsar 

      Moran, Paul; Kyne, Gillian; Redfern, R. M.; Shearer, Andrew (Oxford journals, 2015-12-31)
      We report on observations of the polarization of optical and γ-ray photons from the Crab nebula and pulsar system using the Galway Astronomical Stokes Polarimeter (GASP), the Hubble Space Telescope, Advanced Camera for ...
    • Recent Results from the VERITAS Collaboration 

      Lang, Mark; Gillanders, Gary (2002)
      A decade after the discovery of TeV gamma-rays from the blazar Mrk 421 (Punch et al. 1992), the list of TeV blazars has increased to five BL Lac objects: Mrk 421 (Punch et al. 1992; Petry et al. 1996; Piron et al. 2001), ...
    • Refinement and validation of an exposure model for the pharmaceutical industry 

      Mc Donnell, Patricia E.; Coggins, Marie (2011)
      Objectives: Assessment of worker's exposure is becoming increasingly critical in the pharmaceutical industry as drugs of higher potency are being manufactured. The batch nature of operations often makes it difficult to ...
    • Residential ventilation and health 

      Coggins, Marie; Jones, Simon (Air Infiltration and Ventilation Centre (AIVC) and International Energy Agency (IEA), 2021-07)
      AIVC Technical Note 68 (TN 68) "Residential Ventilation and Health is one of the outcomes of the work performed under the framework of AIVC s project Ventilation & Health and benefited from contributions by several ...
    • Rotational Modulation of M/L Dwarfs due to Magnetic Spots 

      Butler, Ray (2007)
      We find periodic I-band variability in two ultracool dwarfs, TVLM 513-46546 and 2MASS J00361617+1821104, on either side of the M/L dwarf boundary. Both of these targets are short-period radio transients, with the detected ...