Browsing UMBC Physics Department by Title

Now showing items 484-503 of 882

    • Multidisciplinary Education on Big Data + HPC + Atmospheric Sciences 

      Wang, Jianwu; Gobbert, Matthias K.; Zhang, Zhibo; Gangopadhyay, Aryya; Page, Glenn G. (National Science Foundation, 2017-11-01)
      We present a new initiative to create a training program or graduate-level course (cybertraining.umbc.edu) in big data applied to atmospheric sciences as application area and using high-performance computing as indispensable ...

    • Multimessenger observations of a flaring blazar coincident with high-energy neutrino IceCube-170922A 

      Ojha, Roopesh; et al. (American Association for the Advancement of Science, 2018-07-13)

    • MULTIWAVELENGTH EVIDENCE FOR QUASI-PERIODIC MODULATION IN THE GAMMA-RAY BLAZAR PG 1553+113 

      Ojha, R.; Corbet, R. H. D. (IOP, 2015-11-10)
      We report for the first time a γ-ray and multiwavelength nearly periodic oscillation in an active galactic nucleus. Using the Fermi Large Area Telescope we have discovered an apparent quasi-periodicity in the γ-ray flux ...

    • MULTIWAVELENGTH REFRACTION MODELING IMPROVEMENTS FOR SLR OBSERVATIONS 

      Hulley, G.; Pavlis, E. C.; Mendes, V. B.; Pavlis, D. E.
      Atmospheric refraction is an important accuracy-limiting factor in the use of satellite laser ranging (SLR) for high-accuracy science applications. In most of these applications, and particularly for the establishment and ...

    • 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 ...

    • Multiwavelength variability and correlation studies of Mrk 421 during historically low X-ray and γ-ray activity in 2015–2016 

      Lien, A.Y.; et al. (Oxford University Press, 2020-12-08)
      We report a characterization of the multi-band flux variability and correlations of the nearby (z=0.031) blazar Markarian 421 (Mrk 421) using data from Metsähovi, Swift, Fermi-LAT, MAGIC, FACT and other collaborations and ...

    • A MULTIZONE MODEL FOR SIMULATING THE HIGH-ENERGY VARIABILITY OF TeV BLAZARS 

      Graff, Philip B.; Georganopoulos, Markos; Perlman, Eric S.; Kazanas, Demosthenes (The American Astronomical Society, 2008-08-12)
      We present a time-dependent multizone code for simulating the variability of synchrotron self-Compton (SSC) sources. The code adopts a multizone pipe geometry for the emission region, appropriate for simulating emission ...

    • The MURALES survey I. A dual AGN in the radio galaxy 3C 459? 

      Balmaverde, B.; Capetti, A.; Marconi, A.; Venturi, G.; Chiaberge, M.; Baldi, R. D.; Baum, S.; Gilli, R.; Grandi, P.; Meyer, E.; Miley, G.; O’Dea, C.; Sparks, W.; Torresi, E.; Tremblay, G. (EDP sciences, 2018-08-02)
      We observed the FR II radio galaxy 3C 459 (z = 0.22) with the MUSE spectrograph at the Very Large Telescope (VLT) as part of the MURALES project (a MUse RAdio Loud Emission line Snapshot survey). We detected diffuse nuclear ...

    • The MURALES survey. II. Presentation of the observations and first results 

      Balmaverde, Barbara; Capetti, Alessandro; Marconi, Alessandro; Venturi, Giacomo; Chiaberge, M.; Baldi, R.D.; Baum, S.; Gilli, R.; Grandi, P.; Meyer, E.; Miley, G.; O'Dea, C.; Sparks, W.; Torresi, E.; Tremblay, G. (2019-03-27)
      We present observations of a complete sub sample of 20 radio galaxies from the Third Cambridge Catalog (3C) with redshift <0.3 obtained from VLT/MUSE optical integral field spectroscoph. These data have been obtained as ...

    • The MURALES survey. III. Completing the MUSE observations of 37 3C low-z radio galaxies 

      Balmaverde, Barbara; Capetti, Alessandro; Marconi, Alessandro; Venturi, Giacomo; Chiaberge, M.; Baldi, R.D.; Baum, S.; Gilli, R.; Grandi, P.; Meyer, Eileen T.; Miley, G.; Dea, C. O.; Sparks, W.; Torresi, E.; Tremblay, G. (2020-10-21)
      We present the final observations of a complete sample of 37 radio galaxies from the Third Cambridge Catalog (3C) with redshift <0.3 and declination <20 degrees obtained with the VLT/MUSE optical integral field spectrograph. ...

    • Nanofiber-segment ring resonator 

      Jones, D.E.; Hickman, G. T.; Franson, J.D.; Pittman, T.B. (OSA Publishing, 2016)
      We describe a fiber ring resonator comprised of a relatively long loop of standard single-mode fiber with a short nanofiber segment. The evanescent mode of the nanofiber segment allows the cavity-enhanced field to interact ...

    • The NASA Carbon Airborne Flux Experiment (CARAFE): instrumentation and methodology 

      Wolfe, Glenn M.; Kawa, S. Randy; Hanisco, Thomas F.; Hannun, Reem A.; Newman, Paul A.; Swanson, Andrew; Bailey, Steve; Barrick, John; Thornhill, K. Lee; Diskin, Glenn; DiGangi, Josh; Nowak, John B.; Sorenson, Carl; Bland, Geoffrey; Yungel, James K.; Swenson, Craig A. (Copernicus Publications, 2018-03-28)
      The exchange of trace gases between the Earth's surface and atmosphere strongly influences atmospheric composition. Airborne eddy covariance can quantify surface fluxes at local to regional scales (1–1000 km), potentially ...

    • NASA’s Next Generation Space Geodesy Network Typical Core Site Requirements and Layout 

      Esper, J.; Long, J. L.; Lemoine, F. G.; McCormick, D. R.; Merkowitz, S. M.; Ma, C.; McGarry, J. F.; Hilliard, L.; Pavlis, E. C.; Pearlman, M. R.; Stowers, D. A.; Wetzel, S. L. (NASA, 2014-10-14)
      NASA’s renewed commitment to the deployment of a new network of “core” space geodetic sites requires careful planning and consideration for location selection, instrument and facility layout, and required infrastructure. ...

    • NASA’s Next Generation Space Geodesy Project 

      NASA Goddard Space Flight Center Jet Propulsion Laboratory (NASA, 2011-12-16)
      This proposal describes NASA’s Space Geodesy Project. This two-year project will contribute to the Global Geodetic Core Network by: (1) Completing ongoing Network Design Studies that describe the appropriate number and ...

    • The nature of the X-ray flash of August 24 2005 

      Sollerman, J.; Fynbo, J. P. U.; Gorosabe, J.; Halpern, J. P.; Hjorth, J.; Jakobsson, P.; Mirabal, N.; Watson, D.; Xu, D.; Castro-Tirado, A. J.; Féron, C.; Jaunsen, A. O.; Jelínek, M.; Jensen, B. L.; Kann, D. A.; Ovaldsen, J. E.; Pozanenko, A.; Stritzinger, M.; Thöne, C. C.; Postigo, A. de Ugarte; Guziy, S.; Ibrahimov, M.; Järvinen, S. P.; Levan, A.; Rumyantsev, V.; Tanvir, N. (EDP sciences, 2007-04-24)
      Aims. Our aim is to investigate the nature of the X-Ray Flash (XRF) of August 24, 2005. Methods. We present comprehensive photometric R-band observations of the fading optical afterglow of XRF 050824, from 11 minutes to ...

    • Near-infrared and gamma-ray monitoring of TANAMI gamma-ray bright sources 

      Nesci, R.; Tosti, G.; Pursimo, T.; Ojha, R.; Kadler, M. (EDP sciences, 2013-06-18)
      Context. Spectral energy distribution and its variability are basic tools for understanding the physical processes operating in active galactic nuclei (AGN). Aims. In this paper we report the results of a one-year ...

    • Negative entropy production rates in Drude-Sommerfeld metals 

      Bonança, Marcus V. S.; Nazé, Pierre; Deffner, Sebastian (2020-09-30)
      It is a commonly accepted creed that in typical situations the rate of entropy production is non-negative. We show that this assertion is not entirely correct if a time-dependent, external perturbation is not compensated ...

    • Net radiative effects of dust in the tropical North Atlantic based on integrated satellite observations and in situ measurements 

      Song, Qianqian; Zhang, Zhibo; Yu, Hongbin; Kato, Seiji; Yang, Ping; Colarco, Peter; Remer, Lorraine A.; Ryder, Claire L. (Copernicus Publications, 2018-08-13)
      In this study, we integrate recent in situ measurements with satellite retrievals of dust physical and radiative properties to quantify dust direct radiative effects on shortwave (SW) and longwave (LW) radiation (denoted ...

    • 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 ...

    • A new airborne laser-induced fluorescence instrument for in situ detection of formaldehyde throughout the troposphere and lower stratosphere 

      Cazorla, M.; Wolfe, G. M.; Bailey, S. A.; Swanson, A. K.; Arkinson, H. L.; Hanisco, T. F. (Copernicus, 2015-02-03)
      The NASA In Situ Airborne Formaldehyde (ISAF) instrument is a high-performance laser-based detector for gas-phase formaldehyde (HCHO). ISAF uses rotational-state specific laser excitation at 353 nm for laser-induced ...