Browsing School of Physics by Title
Now showing items 140-159 of 175
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TeV and Multi-wavelength Observations of Mrk 421 in 2006-2008
(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
(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 ... -
Three-dimensional depth-resolved and extended-resolution micro-particle characterization by holographic light scattering spectroscopy
(Optica, 2010)Fourier-holographic light scattering spectroscopy is applied to record complex angular scattering spectra of two- and three-dimensional samples over a wide field of view. We introduce a computational depth sectioning ... -
Tissue viability imaging of skin microcirculation following exposure to Cold Air (-110°C) and Cold Water (8°C)
(CIAFEL, 2013)Cryotherapy is currently used in various clinical, rehabilitative and sporting settings. However, very little is known regarding the impact of cooling on the microcirculatory response. Objectives: The present study sought ... -
Top-down and bottom-up aerosol-cloud closure: towards understanding sources of uncertainty in deriving cloud shortwave radiative flux
(European Geosciences Union (EGU), 2017-08-22)Top-down and bottom-up aerosol-cloud shortwave radiative flux closures were conducted at the Mace Head Atmospheric Research Station in Galway, Ireland, in August 2015. This study is part of the BACCHUS (Impact of Biogenic ... -
Tracking potential sources of peak ozone concentrations in the upper troposphere over the Arabian Gulf region.
(Elsevier (Science Direct), 2014-11-13)In August 2013, the Qatar Environment and Energy Research Institute (QEERI), was the first to launch temporally highly resolved ozonesondes in the Middle East region. The data from 20 launches consistently show changes in ... -
Ultra-sensitive label free imaging below the resolution limit
(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
(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
(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
(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
(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
(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
(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 detection of LS 5039 and HESS J1825-137
(Elsevier, 2019-11-07)With 8 h of observations, VERITAS confirms the detection of two very high energy gamma-ray sources. The gamma-ray binary LS 5039 is detected with a statistical significance of 8.8σ. The measured flux above 1 TeV is near ... -
VERITAS Discovery of >200GeV Gamma-ray Emission from the Intermediate-frequency-peaked BL Lac Object W Comae
(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
(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
(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
(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
(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 ...