Now showing items 956-971 of 971

    • The X-Ray Afterglow of Dark GRB 970815: A Common Origin for Gamma-Ray Bursts and X-Ray Flashes? 

      Mirabal, N.; Halpern, J. P.; Gotthelf, E. V.; Mukherjee, R. (IOP, 2004-10-25)
      GRB 970815 is a well-localized gamma-ray burst (GRB) detected by the All-Sky Monitor (ASM) on the Rossi X-Ray Timing Explorer (RXTE) for which no afterglow was identified despite follow-up ASCA and ROSAT pointings and ...
    • X-Ray and GeV Gamma-Ray Variability of the Radio Galaxy NGC 1275 

      Fukazawa, Yasushi; Shiki, Kensei; Tanaka, Yasuyuki; Itoh, Ryosuke; Takahashi, Hiromitsu; Imazato, Fumiya; Dutka, Filippo; Ojha, Roopesh; Nagai, Hiroshi (IOP, 2018-03-12)
      We analyzed Suzaku/XIS data (2006–2015) and Fermi/LAT data (2008–2015) of the gamma-ray emitting radio galaxy NGC 1275. Correlated brightening of the nucleus in both the X-ray and GeV gamma-ray energy bands was found for ...
    • X-ray Binary Luminosity Function Scaling Relations in Elliptical Galaxies: Evidence for Globular Cluster Seeding of Low-Mass X-ray Binaries in Galactic Fields 

      Lehmer, Bret D.; Ferrell, Andrew P.; Doore, Keith; Eufrasio, Rafael T.; Monson, Erik B.; Alexander, David M.; Basu-Zych, Antara; Brandt, William N.; Sivakoff, Greg; Tzanavaris, Panayiotis; Yukita, Mihoko; Fragos, Tassos; Ptak, Andrew (2020-04-27)
      We investigate X-ray binary (XRB) luminosity function (XLF) scaling relations for Chandra detected populations of low-mass XRBs (LMXBs) within the footprints of 24 early-type galaxies. Our sample includes Chandra and HST ...
    • X-ray emission from magnetized neutron star atmospheres at low mass accretion rates. I. Phase-averaged spectrum 

      Sokolova-Lapa, E.; Gornostaev, M.; Wilms, J.; Ballhausen, R.; Falkner, S.; Postnov, K.; Thalhammer, P.; Fürst, F.; García, J. A.; Shakura, N.; Becker, P. A.; Wolff, M. T.; Pottschmidt, Katja; Härer, L.; Malacaria, C.
      Recent observations of X-ray pulsars at low luminosities allow, for the first time, to compare theoretical models for the emission from highly magnetized neutron star atmospheres at low mass accretion rates (M˙≲1015 g s−1) ...
    • The X-ray emission mechanism of large scale powerful quasar jets: Fermi rules out IC/CMB for 3C 273 

      Georganopoulos, Markos; Meyer, Eileen T. (EDP sciences, 2013-12-09)
      The process responsible for the Chandra-detected X-ray emission from the large-scale jets of powerful quasars is not clear yet. The two main models are inverse Compton scattering off the cosmic microwave background photons ...
    • X-ray evolution of the nova V959 Mon suggests a delayed ejection and a non-radiative shock 

      Nelson, Thomas; Mukai, Koji; Chomiuk, Laura; Sokoloski, Jennifer L.; Linford, Justin D.; Finzell, Thomas; Mioduszewski, Amy J.; Rupen, Michael P.; Weston, Jennifer; Oliveira, Raimundo Lopes de (2020-07-30)
      X-ray observations of shocked gas in novae can provide a useful probe of the dynamics of the ejecta. Here we report on X-ray observations of the nova V959 Mon, which was also detected in GeV gamma-rays with the Fermi ...
    • X-ray monitoring of the radio and γ-ray loud Narrow-Line Seyfert 1 Galaxy PKS2004–447 

      Kreikenbohm, A.; Kadler, M.; Wilms, J.; Schulz, R.; Müller, C.; Ojha, R.; Ros, E.; Mannheim, K.; Elsässer, D. (EDP sciences, 2013-12-09)
      We present preliminary results of the X-ray analysis of XMM-Newton and Swift observations as part of a multi-wavelength monitoring campaign in 2012 of the radio-loud narrow line Seyfert 1 galaxy PKS 2004–447. The source ...
    • An X-ray spectral study of the origin of reflection features in bare Seyfert 1 galaxy ESO 511--G030 

      Ghosh, Ritesh; Laha, Sibasish (2020-12-19)
      The reprocessed X-ray emission from Active Galactic Nuclei (AGN) is an important diagnostic tool to study the dynamics and geometry of the matter surrounding the supermassive black holes (SMBHs). We present a broadband ...
    • X-ray variability analysis of a large series of XMM–Newton +NuSTAR observations of NGC 3227 

      Lobban, A. P.; Turner, T. J.; Reeves, J. N.; Braito, V.; Miller, L. (Oxford University Press, 2020-04-16)
      We present a series of X-ray variability results from a long XMM–Newton + NuSTAR campaign on the bright, variable AGN NGC 3227. We present an analysis of the light curves, showing that the source displays typically ...
    • X-Ray-to-Radio Offset Inference from Low-Count X-Ray Jets 

      Reddy, Karthik; Georganopoulos, Markos; Meyer, Eileen T.
      Observations of positional offsets between the location of X-ray and radio features in many resolved, extragalactic jets indicates that the emitting regions are not co-spatial, an important piece of evidence in the debate ...
    • Xenon-based Nonlinear Fabry-Perot Interferometer for Quantum Information Applications 

      Hickman, G. T.; Pittman, T.B.; Franson, J.D. (OSA Publishing, 2015-05)
      We describe a nonlinear Fabry-Perot interferometer useful for optical quantum information applications. We observe self-phase modulation and other nonlinear effects with ultra-low input powers using metastable xenon in a ...
    • XMM-Newton observations of eleven intermediate polars and possible candidates 

      Wörpel, Hauke; Schwope, Axel; Traulsen, Iris; Mukai, Koji; Ok, Samet (EDP sciences, 2020-07-02)
      Aims. We aim to identify new intermediate polars (IPs) in XMM-Newton observations from a list of promising candidates. By selecting targets not previously known to be X-ray bright, we aim to uncover evidence for an X-ray ...
    • Zeno logic gates using microcavities 

      Franson, James D.; Pittman, Todd B.; Jacobs, Bryan C. (OSA Publishing, 2007)
      The linear optics approach to quantum computing has several potential advantages, but the logic operations are probabilistic. We review the use of the quantum Zeno effect to suppress the intrinsic failure events in these ...
    • γ-RAY AND PARSEC-SCALE JET PROPERTIES OF A COMPLETE SAMPLE OF BLAZARS FROM THE MOJAVE PROGRAM 

      Meyer, E. T. et al. (IOP, 2011-11-02)
      We investigate the Fermi Large Area Telescope γ-ray and 15 GHz Very Long Baseline Array radio properties of a joint γ-ray and radio-selected sample of active galactic nuclei (AGNs) obtained during the first 11 months of ...
    • The γ-ray properties of radio-selected extragalactic jets 

      Bock, M.; Kadler, M.; Tosti, G.; Burnett, T.H.; Muller, C.; Ojha, R.; LAT collaboration; Wilms, J. (2010-06-13)
      Most extragalactic jets in radio-loud Active Galactic Nuclei are bright and variable gamma-ray sources, which are continuously monitored with Fermi/LAT. We present the gamma-ray properties of the MOJAVE and TANAMI AGN ...
    • Untitled 

      Zhao, Xingchen; Peng, Tao; Yi, Zhenhuan; Zhang, Lida; Zubairy, M. Suhail; Shih, Yanhua; Scully, Marlan O. (2020-12-11)
      We develop a method based on the cross-spectrum of an intensity-modulated CW laser, which can extract a signal from an extremely noisy environment and image objects hidden in turbid media. We theoretically analyzed our ...