Now showing items 46-65 of 94

  • Nanosensitive optical coherence tomography for the study of changes in static and dynamic structures 

    Subhash, Hrebesh M.; Leahy, Martin (IOP Science, 2014-03-06)
    We briefly discuss the principle of image formation in Fourier domain optical coherence tomography (OCT). The theory of a new approach to improve dramatically the sensitivity of conventional OCT is described. The approach ...
  • Novel approach for label free super-resolution imaging in far field 

    Alexandrov, Sergey; McGrath, James; Hrebesh, Subhash; Leahy, Martin (Nature Publishing Group, 2015)
    Progress in the emerging areas of science and technology, such as bio- and nano-technologies, depends on development of corresponding techniques for imaging and probing the structures with high resolution. Recently, the ...
  • 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 ...
  • 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 ...
  • 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 ...
  • 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 ...
  • 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 ...
  • A search for CO+ in planetary nebulae 

    Redman, Matt P. (2007)
    We have carried out a systematic search for the molecular ion CO+ in a sample of 8 protoplanetary and planetary nebulae in order to determine the origin of the unexpectedly strong HCO+ emission previously detected in these ...
  • A Search for Dark Matter Annihilation with the Whipple 10m Telescope 

    Lang, Mark (2008)
    We present observations of the dwarf galaxies Draco and Ursa Minor, the local group galaxies M32 and M33, and the globular cluster M15 conducted with the Whipple 10m gamma-ray telescope to search for the gamma-ray signature ...
  • A search for optical bursts from RRAT J1819-1458: II. Simultaneous ULTRACAM-Lovell Telescope observations 

    Shearer, Andrew (2011)
    The Rotating RAdio Transient (RRAT) J1819-1458 exhibits ~3 ms bursts in the radio every ~3 min, implying that it is visible for only ~1 per day. Assuming that the optical light behaves in a similar manner, long exposures ...
  • 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 ...
  • A Search for Pulsed TeV Gamma Ray Emission from the Crab Pulsar 

    Lang, Mark; Gillanders, Gary; Burdett, A. M.; Bond, I. H.; Boyle, P. J.; Bradbury, S. M.; Buckley, J. H.; Carter-Lewis, D. A.; Catanese, M.; Cawley, M. F.; D'Vali, M.; Fegan, D. J.; Fegan, S. J.; Finley, J. P.; Gaidos, J. A.; Gillanders, G. H.; Hall, T. A.; Hillas, A. M.; Kildea, J.; Knapp, J.; Krennrich, F.; Lang, M. J.; LeBohec, S.; Lessard, R. W.; 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 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 (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; 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 ...