Now showing items 1-20 of 822

    • Postselection-free energy-time entanglement 

      Strekalov, D. V.; Pittman, T.B.; Sergienko, A. V.; Shih, Y. H.; Kwiat, P. G. (American Physical Society (APS), 1996-07-01)
      We report a two-photon interference experiment that realizes a postselection-free test of Bell's inequality based on energy-time entanglement. In contrast with all previous experiments of this type, the employed entangled ...
    • Can Two-Photon Interference be Considered the Interference of Two Photons? 

      Pittman, T. B.; Strekalov, D. V.; Migdall, A.; Rubin, M. H.; Sergienko, A. V.; Shih, Y. H. (American Physical Society (APS), 1996-09-02)
      We report on a “postponed compensation” experiment in which the observed two-photon entangled state interference cannot be pictured in terms of the overlap of the two individual photon wave packets of a parametric ...
    • Electron-positron jets associated with the quasar 3C279 

      Wardle, J.F.C.; Homan, D.C.; Ojha, R.; Roberts, D.H. (Brandeis University, 1998)
      A long outstanding problem in extragalactic astrophysics is the composition of the relativistic jets of plasma streaming from the nuclei of quasars and active galaxies - whether it is predominantly a "normal" (electron-proton) ...
    • Multi-Photon Entanglement and Quantum Teleportation 

      Shih, Yanhua (U. S. Army Research Office, 1999-07-31)
      The project "Multi-Photon Entanglement and Quantum Teleportation" concerns a series of experimental and theoretical investigations on multi-photon entangled states and the applications, for example, quantum teleportation. ...
    • Quantum logic using photon-exchange interactions 

      Franson, J.D.; Pittman, T.B. (OSA Publishing, 2000-05)
      Nonlinear optical effects at the two-photon level are usually negligible because of the weak electric field associated with a single photon.
    • Search for the Identification of 3EG J1835+5918: Evidence for a New Type of High-Energy Gamma-Ray Source 

      Mirabal, N.; Halpern, J. P.; Eracleous, M.; Becker, R. H. (IOP, 2000-05-10)
      The EGRET source 3EG J1835+5918 is the brightest and most accurately positioned of the as-yet unidentified high-energy γ-ray sources at high Galactic latitude (ℓ,b = 89°,25°). We present a multiwavelength study of the ...
    • 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 ...
    • The Antarctic Submillimeter Telescope and Remote Observatory (AST/RO) 

      Stark, Antony A.; Bally, John; Balm, Simon P.; Bania, T. M.; Bolatto, Alberto D.; Chamberlin, Richard A.; Engargiola, Gregory; Huang, Maohai; Ingalls, James G.; Jacobs, Karl; Jackson, James M.; Kooi, Jacob W.; Lane, Adair P.; Lo, K.-Y.; Marks, Rodney D.; Martin, Christopher L.; Mumma, Dennis; Ojha, Roopesh; Schieder, Rudolf; Staguhn, Johannes; Stutzki, Juergen; Walker, Christopher K.; Wilson, Robert W.; Wright, Gregory A.; Zhang, Xiaolei; Zimmermann, Peter; Zimmermann, Ruediger (IOP, 2000-12-15)
      AST/RO, a 1.7 m diameter telescope for astronomy and aeronomy studies at wavelengths between 200 and 2000 microns, was installed at the South Pole during the 1994-1995 Austral summer. The telescope operates continuously ...
    • A Neutron Star Identification for the High-Energy Gamma-Ray Source 3EG J1835+5918 Detected in the ROSAT All-Sky Survey 

      Mirabal, N.; Halpern, J. P. (IOP, 2001-01-24)
      In the error box of 3EG J1835+5918, the brightest as-yet unidentified EGRET source at intermediate Galactic latitude, we find a weak, ultrasoft X-ray source at energies E < 0.3 keV in the ROSAT All-Sky Survey. Deep optical ...
    • AST/RO Observations of Atomic Carbon near the Galactic Center 

      Ojha, Roopesh; Stark, Antony A.; Hsieh, Henry H.; Lane, Adair P.; Chamberlin, Richard A.; Bania, Thomas M.; Bolatto, Alberto D.; Jackson, James M.; Wright, Gregory A. (IOP, 2001-02-10)
      We present a coarsely sampled map of the region |l| ≤ 2°, |b| ≤ 0°1 in the 492 GHz (³P₁ → ³P₀) fine-structure transition of neutral carbon, observed with the Antarctic Submillimeter Telescope and Remote Observatory (AST/RO). ...
    • Multicolor Observations of the GRB 000926 Afterglow 

      Price, P. A.; Harrison, F. A.; Galama, T. J.; Reichart, D. E.; Axelrod, T. S.; Berger, E.; Bloom, J. S.; Busche, J.; Cline, T.; Diercks, A.; Djorgovski, S. G.; Frail, D. A.; Gal-Yam, A.; Halpern, J.; Holtzman, J. A.; Hunt, M.; Hurley, K.; Jacoby, B.; Kimble, R.; Kulkarni, S. R.; Mirabal, N.; Morrison, G.; Ofek, E.; Pevunova, O.; Sari, R.; Schmidt, B. P.; Turnshek, D.; Yost, S. (IOP, 2001-02-26)
      We present multicolor light curves of the optical afterglow of gamma-ray burst (GRB) 000926. Beginning ~1.5 days after the burst, the light curves of this GRB steepen measurably. The existence of such achromatic breaks is ...
    • Parsec-Scale Blazar Monitoring: Proper Motions 

      Homan, Daniel C.; Ojha, Roopesh; Wardle, John F. C.; Roberts, David H.; Aller, Margo F.; Aller, Hugh D.; Philip A. Hughes (IOP, 2001-03-10)
      We present proper motions obtained from a dual-frequency, six-epoch, VLBA polarization experiment monitoring a sample of 12 blazars. The observations were made at 15 and 22 GHz at bimonthly intervals over 1996. A total of ...
    • Tidal Satellite Perturbations and the Lense-Thirring Effect 

      Iorio, Lorenzo; Pavlis, Erricos C. (The Geodetic Society of Japan, 2001-03-25)
    • 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, ...
    • Probabilistic quantum logic operations using polarizing beam splitters 

      Pittman, T. B.; Jacobs, B. C.; Franson, J. D. (American Physical Society (APS), 2001-11-16)
      It has previously been shown that probabilistic quantum logic operations may be performed using linear optical elements, additional photons (ancilla), and post-selection based on the output of single-photon detectors. Here ...
    • Parsec-Scale Blazar Monitoring: Flux and Polarization Variability 

      Homan, Daniel C.; Ojha, Roopesh; Wardle, John F. C.; Roberts, David H.; Aller, Margo F.; Aller, Hugh D.; Hughes, Philip A. (IOP, 2002-03-20)
      We present analysis of the flux density and polarization variability of parsec-scale radio jets from a dual-frequency, six-epoch, VLBA polarization experiment monitoring 12 blazars. The observations were made at 15 and 22 ...
    • Is the EGRET Source 3EG J1621+8203 the Radio Galaxy NGC 6251? 

      Mukherjee, R.; Halpern, J.; Mirabal, N.; Gotthelf, E. V. (IOP, 2002-04-03)
      We discuss the nature of the unidentified EGRET source 3EG J1621+8203. In an effort to identify the gamma-ray source, we have examined X-ray images of the field from ROSAT PSPC, ROSAT HRI, and ASCA GIS. Of the several faint ...
    • Improved mapping functions for atmospheric refraction correction in SLR 

      Mendes, V. B.; Prates, G.; Pavlis, E.C.; Pavlis, D.E.; Langley, R. B. (AGU Pubication, 2002-05-24)
      We present two new mapping functions (MFs) to model the elevation angle dependence of the atmospheric delay for satellite laser ranging (SLR) data analysis. The new MFs were derived from ray tracing through a set of data ...
    • Multiwavelength Searches of Unidentified EGRET Sources 

      Mirabal, N.; Halpern, J.; Mukherjee, R.; Gotthelf, E.; Camilo, F. (2002-05-28)
      3EG J1835+5918 is the brightest of the so-called unidentified EGRET sources at intermediate galactic latitude (l,b)=(89,25). We obtained complete radio, optical, and X-ray coverage of its error box, discovering a faint ...
    • The Next Geminga: Deep Multiwavelength Observations of a Neutron Star Identified with 3EG J1835+5918 

      Halpern, J. P.; Gotthelf, E. V.; Mirabal, N.; Camilo, F. (IOP, 2002-06-02)
      We describe Chandra, Hubble Space Telescope (HST), and radio observations that reveal a radio-quiet but magnetospherically active neutron star in the error circle of the high-energy γ-ray source 3EG J1835+5918, the brightest ...