Now showing items 945-964 of 971

    • Was the X-ray Afterglow of GRB 970815 Detected? 

      Mirabal, N.; Halpern, J. P.; Gotthelf, E. V.; Mukherjee, R. (AIP publishing, 2004-10-01)
      GRB 970815 was 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 ...
    • A weakening Compton hump and soft X-ray excess detected in the Seyfert-1 galaxy MCG-02-58-22 

      Laha, Sibasish; Ghosh, Ritesh (IOP Publishing, 2021-04-29)
      We have carried out an extensive X-ray spectral study of the bare Seyfert-1 galaxy MCG--02--58--22 to ascertain the nature of the X-ray reprocessing media, using observations from Suzaku (2009) and simultaneous observations ...
    • The WEBT Campaign on the Blazar 3C 279 in 2006 

      Mirabal, N.; et al. (IOP, 2007-08-16)
      The quasar 3C 279 was the target of an extensive multiwavelength monitoring campaign from 2006 January through April. An optical-IR-radio monitoring campaign by the Whole Earth Blazar Telescope (WEBT) collaboration was ...
    • Weekly solutions: station coordinates, non-linear station behaviours, systematic effects 

      Pavlis, Erricos C.; Biancale, Richard (International Earth Rotation and Reference Systems Service, 2005-10-10)
    • What can Fermi tell us about CTA? 

      Garcıa, R.; Curras, E.; Mirabal, N.; Contreras, J.L.; Carmona, E. (2010-09)
    • What is the Structure of Relativistic Jets in AGN on Scales of Light Days? 

      Zacharias, Norbert; Johnston, Kenneth; Boboltz, David; Fey, Alan L.; Gaume, Ralph; Ojha, Roopesh; Meier, David L.; Murphy, David W.; Jones, Dayton L.; Unwin, Stephen C.; Piner, B. Glenn (2009-02-11)
      The structure of relativistic jets in AGN on scales of light days reveals how energy propagates through jets, a process that is fundamental to galaxy evolution. A deeper understanding of jet physics will clarify the ...
    • Where Does Work End and Home Life Begin? 

      Berge, Zane L.; Bichy, Cassie; Grayson, Candice; Johnson, Anthony; Macadoff, Stephen; Nee, Kathryn (IGI Global Disseminator of Knowledge, 2009)
      Many years ago, it was a commonly held belief that technology would improve industries and service professions, which means that people could work shorter hours and their employers would make just as much money. Essentially, ...
    • WHY DO COMPACT ACTIVE GALACTIC NUCLEI AT HIGH REDSHIFT SCINTILLATE LESS? 

      Koay, J. Y.; Macquart, J-P.; Rickett, B. J.; Bignall, H. E.; Jauncey, D. L.; Pursimo, T.; Reynolds, C.; Lovell, J. E. J.; Kedziora-Chudczer, L.; Ojha, R. (IOP, 2012-08-12)
      The fraction of compact active galactic nuclei (AGNs) that exhibit interstellar scintillation (ISS) at radio wavelengths, as well as their scintillation amplitudes, have been found to decrease significantly for sources at ...
    • Why do models overestimate surface ozone in the Southeast United States 

      Travis, Katherine R.; Jacob, Daniel J.; Fisher, Jenny A.; Kim, Patrick S.; Marais, Eloise A.; Zhu, Lei; Yu, Karen; Miller, Christopher C.; Yantosca, Robert M.; Sulprizio, Melissa P.; Thompson, Anne M.; Wennberg, Paul O.; Crounse, John D.; St. Clair, Jason M.; Cohen, Ronald C.; Laughner, Joshua L.; Dibb, Jack E.; Hall, Samuel R.; Ullmann, Kirk; Wolfe, Glenn M.; Pollack, Illana B.; Peischl, Jeff; Neuman, Jonathan A.; Zhou, Xianliang (Copernicus Publications, 2016-11-01)
      Ozone pollution in the Southeast US involves complex chemistry driven by emissions of anthropogenic nitrogen oxide radicals (NOx  ≡  NO + NO₂) and biogenic isoprene. Model estimates of surface ozone concentrations tend to ...
    • Willman 1: An X-ray shot in the dark with Chandra 

      Nieto, D.; Mirabal, N. (2010-03-19)
      The sterile neutrino is a weakly-interacting particle that emerges in the framework of certain extensions of standard particle physics and that fits naturally with the properties of a warm dark matter particle candidate. ...
    • Wintertime Overnight NOx Removal in a Southeastern United States Coal‐fired Power Plant Plume: A Model for Understanding Winter NOx Processing and its Implications 

      Fibiger, Dorothy L.; McDuffie, Erin E.; Dubé, William P.; Aikin, Kenneth C.; Lopez‐Hilfiker, Felipe D.; Lee, Ben H.; Green, Jamie R.; Fiddler, Marc N.; Holloway, John S.; Ebben, Carlena; Sparks, Tamara L.; Wooldridge, Paul; Weinheimer, Andrew J.; Montzka, Denise D.; Apel, Eric C.; Hornbrook, Rebecca S.; Hills, Alan J.; Blake, Nicola J.; DiGangi, Josh P; Wolfe, Glenn M.; Bililign, Solomon; Cohen, Ronald C.; Thornton, Joel A.; Brown, Steven S. (AGU Pubication, 2018-01-05)
      Nitric oxide (NO) is emitted in large quantities from coal‐burning power plants. During the day, the plumes from these sources are efficiently mixed into the boundary layer, while at night, they may remain concentrated due ...
    • 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 ...