Now showing items 298-317 of 863

    • GNSS Session A: Synergy of SLR and GNSS Data Products 

      Pavlis, Erricos C. (National Aeronautics and Space Administration, 2015-10-26)
    • GRB 000418: A Hidden Jet Revealed 

      Berger, E.; Diercks, A.; Frail, D. A.; Kulkarni, S. R.; Bloom, J. S.; Sari, R.; Halpern, J.; Mirabal, N.; Taylor, G. B.; Hurley, K.; Pooley, G.; Becker, K. M.; Wagner, R. M.; Terndrup, D. M.; Statler, T.; Wik, D. R.; Mazets, E.; Cline, T. (IOP, 2001-04-05)
      We report on optical, near-infrared, and centimeter radio observations of GRB 000418 that allow us to follow the evolution of the afterglow from 2 to 200 days after the γ-ray burst (GRB). In modeling these broadband data, ...
    • GRB 021004: A Possible Shell Nebula around a Wolf-Rayet Star Gamma-Ray Burst Progenitor 

      Mirabal, N.; Halpern, J. P.; Chornock, Ryan; Filippenko, Alexei V.; Terndrup, D. M.; Armstrong, E.; Kemp, J.; Thorstensen, J. R.; Tavarez, M.; Espaillat, C. (IOP, 2003-06-06)
      The rapid localization of GRB 021004 by the HETE-2 satellite allowed nearly continuous monitoring of its early optical afterglow decay, as well as high-quality optical spectra that determined a redshift of z3 = 2.328 for ...
    • GRB 050826: A Subluminous Event at z=0.296 Finds Its Place in the Luminosity Distribution of Gamma-Ray Burst Afterglows 

      Mirabal, N.; Halpern, J. P.; O'Brien, P. T. (IOP, 2007-05-14)
      We present the optical identification and spectroscopy of the host galaxy of GRB 050826 at redshift z = 0.296 ± 0.001. Image subtraction among observations obtained on three consecutive nights reveals a fading object 5 hr ...
    • GRB 060218/SN 2006aj: A Gamma-Ray Burst and Prompt Supernova at z=0.0335 

      Mirabal, N.; Halpern, J. P.; An, D.; Thorstensen, J. R.; Terndrup, D. M. (IOP, 2006-05-08)
      We report the imaging and spectroscopic localization of GRB 060218 to a low-metallicity dwarf starburst galaxy at z = 0.03345 ± 0.00006. In addition to making it the second nearest gamma-ray burst known, optical spectroscopy ...
    • GRB 991216 Joins the Jet Set: Discovery and Monitoring of its Optical Afterglow 

      Halpern, J. P.; Uglesich, R.; Mirabal, N.; Kassin, S.; Thorstensen, J.; Keel, W. C.; Diercks, A.; Bloom, J. S.; Harrison, F.; Mattox, J.; Eracleous, M. (IOP, 2000-06-15)
      The optical light curve of the energetic γ-ray burst GRB 991216 is consistent with jetlike behavior in which a power-law decay steepens from t⁻¹·²²⁺⁰·⁰⁴ at early times to t⁻¹·⁵³⁺⁰·⁰⁵ in a gradual transition at around 2 ...
    • A Hard X-ray Survey of Radio-Selected Blazars 

      Langejahn, Marcus; Kadler, Matthias; Wilms, Jorn; Bock, M.; Baumgartner, W.H.; Gehrels, N.; Markwardt, C.B.; Tueller, J.
      The MOJAVE program has been monitoring a statistically complete sample of 135 radio-loud active galactic nuclei (AGN) of the northern hemisphere using the Very Long Baseline Array (VLBA). This sample, dominated by low-peaked ...
    • Heralded two-photon entanglement from probabilistic quantum logic operations on multiple parametric down-conversion sources 

      Pittman, T.B.; Donegan, M. M.; Fitch, M. J.; Jacobs, B. C.; Franson, J.D.; Kok, P.; Lee, Hwang; Dowling, J. P. (IEEE, 2018-10-29)
      An ideal controlled-NOT gate followed by projective measurements can be used to identify specific Bell states of its two input qubits. When the input qubits are each members of independent Bell states, these projective ...
    • Heralding single photons from pulsed parametric down-conversion 

      Pittman, T.B.; Jacobs, B. C.; Franson, J.D. (Elsevier, 2004-11-23)
      We describe an experiment in which photon pairs from a pulsed parametric down-conversion source were coupled into single-mode fibers. Detecting one of the photons heralded the presence of the other photon in its fiber with ...
    • HESS and Fermi-LAT discovery of γ-rays from the blazar 1ES 1312−423 

      Ojha, R.; Perkins, J. S. (Oxford University Press, 2013-08-01)
      A deep observation campaign carried out by the High Energy Stereoscopic System (HESS) on Centaurus A enabled the discovery of γ-rays from the blazar 1ES 1312−423, 2° away from the radio galaxy. With a differential flux at ...
    • High resolution rapid response observations of compact radio sources with the Ceduna Hobart Interferometer (CHI) 

      Blanchard, J. M.; Lovell, J. E. J.; Ojha, R.; Kadler, M.; Dickey, J. M.; Edwards, P. G. (EDP sciences, 2012-02-17)
      Context. Frequent, simultaneous observations across the electromagnetic spectrum are essential to the study of a range of astrophysical phenomena including active galactic nuclei. A key tool of such studies is the ability ...
    • High Resolution, AltitudeCorrected Monthly Satellite Precipitation Product Improves Estimates in Mountain Regions 

      Remer, Lorraine A.; Levy, Robert C.; Mattoo, Shana
      Aerosol optical properties derived from an early version of the Dark Target (DT) algorithm applied to the Moderateresolution Imaging Spectroradiometer (MODIS) on Terra, for 12 June 2001
    • High upward fluxes of formic acid from a boreal forest canopy 

      Schobesberger, Siegfried; Lopez‐Hilfiker, Felipe D.; Taipale, Ditte; Millet, Dylan B.; D'Ambro, Emma L.; Rantala, Pekka; Mammarella, Ivan; Zhou, Putian; Wolfe, Glenn M.; Lee, Ben H.; Boy, Michael; Thornton, Joel A. (AGU Pubication, 2016-08-26)
      Eddy covariance fluxes of formic acid, HCOOH, were measured over a boreal forest canopy in spring/summer 2014. The HCOOH fluxes were bidirectional but mostly upward during daytime, in contrast to studies elsewhere that ...
    • High-Fidelity Quantum Logic Operations and Entangled Ancilla States 

      Franson, J.D.; Donegan, M. M.; Fitch, M. J.; Jacobs, B. C.; Pittman, T. B. (OSA Publishing, 2003-06)
      We describe a high-fidelity approach to linear optics quantum computing in which the quantum logic operations always produce an output. A method for generating the required entangled states is also described.
    • High-Fidelity Quantum Logic Operations Using Linear Optical Elements 

      Franson, J.D.; Donegan, M. M.; Fitch, M.J.; Jacobs, B. C.; Pittman, T.B. (American Physical Society (APS), 2002-09-04)
      Knill, Laflamme, and Milburn [Nature (London) 409, 46 (2001)] have shown that quantum logic operations can be performed using linear optical elements and additional ancilla photons. Their approach is probabilistic in the ...
    • High-Resolution Grating Spectroscopy of GRB 020405 with the Chandra Low Energy Transmission Grating Spectrometer 

      Mirabal, N.; Paerels, F.; Halpern, J. P. (IOP, 2002-12-16)
      We present high-resolution X-ray spectroscopy of GRB 020405 obtained with the Low Energy Transmission Grating Spectrometer (LETGS) on board the Chandra X-Ray Observatory starting 1.68 days after the burst. The spectrum ...
    • High-resolution observations of 6.7-GHz methanol masers with the Long Baseline Array 

      Dodson, R.; Ojha, R.; Ellingsen, S. P. (Oxford University Press, 2004-07-01)
      We have used the Australian Long Baseline Array (LBA) to produce milliarcsecond images of five sites of methanol (CH3OH) maser emission at 6.7 GHz. These are all sites that have linear morphologies at arcsecond resolutions, ...
    • High-Resolution Observations of Centaurus A 

      Muller, Cornelia; Blanchard, J.; Bock, M.; Carpenter, B.; Dutka, M.; Furst, F.; Grafe, C.; Großberger, C.; Kadler, M.; Krauß, F.; Markowitz, A.; Ojha, R.; Perucho, M.; Pottschmidt, K.; Ros, E.; Rothschild, R.; Schulz, R.; Trustedt, J.; Wilms, J.; the TANAMI Collaboration (European Space Agency, 2011)
      The closest active galaxy Centaurus A is regularly observed at milliarcsecond resolution within the framework of the Southern Hemisphere AGN monitoring program TANAMI. Additional multiwavelength observations up to gamma-ray ...
    • Highest gamma-ray flux level detected from very high redshift blazar B3 1343+451 

      Ojha, Roopesh; Dutka, Michael; Torresi, Eleonora (The Astronomer's Telegram, 2011-12-01)
    • High‐accuracy zenith delay prediction at optical wavelengths 

      Mendes, V. B.; Pavlis, E. C. (AGU Pubication, 2004-07-16)
      A major limitation in accuracy in modern satellite laser ranging is the modeling of atmospheric refraction. Recent improvements in this area include the development of mapping functions to project the atmospheric delay ...