WorldWideScience

Sample records for wide-range multiwavelength observations

  1. Multiwavelength Observations of Mrk 501 in 2008

    Energy Technology Data Exchange (ETDEWEB)

    Kranich, D.; /Zurich, ETH; Paneque, D.; /SLAC; Cesarini, A.; /Natl. U. of Ireland, Galway; Falcone, A.; /Penn State U., Astron. Astrophys.; Giroletti, M.; /Bologna Observ.; Hoversten, E.; /Penn State U., Astron. Astrophys.; Hovatta, T.; /Helsinki U. of Tech.; Kovalev, Y.Y.; /Bonn, Max Planck Inst., Radioastron.; Lahteenmaki, A.; Nieppola, E.; /Helsinki U. of Tech.; Pagani, C.; /Penn State U., Astron. Astrophys.; Pichel, A.; /Buenos Aires U., IAFE; Satalecka, K.; /DESY; Scargle, J.; /NASA, Ames; Steele, D.; /Adler Planetarium, Chicago; Tavecchio, F.; /INAF, Rome; Tescaro, D.; /Barcelona, IFAE; Tornikoski, M.; /Helsinki U. of Tech.; Villata, M.; /Turin Observ.

    2010-08-25

    The well-studied VHE (E > 100 GeV) blazar Mrk 501 was observed between March and May 2008 as part of an extensive multiwavelength observation campaign including radio, optical, X-ray and VHE gamma-ray instruments. Mrk 501 was in a low state of activity during the campaign, with a low VHE flux of about 20% the Crab Nebula flux. Nevertheless, significant flux variations could be observed in X-rays as well as {gamma}-rays. Overall Mrk 501 showed increased variability when going from radio to {gamma}-ray energies. The broadband spectral energy distribution during the two different emission states of the campaign was well described by a homogeneous one-zone synchrotron self-Compton model. The high emission state was satisfactorily modeled by increasing the amount of high energy electrons with respect to the low emission state. This parameterization is consistent with the energy-dependent variability trend observed during the campaign.

  2. Multiwavelength observations of Mrk 501 in 2008

    Energy Technology Data Exchange (ETDEWEB)

    Aleksic, J.; Ansoldi, S.; Antonelli, L. A.; Antoranz, P.; Babic, A.; Bangale, P.; Barres de Almeida, U.; Barrio, J. A.; Gonzalez, Becerra; Bednarek, W.; Zitzer, B.

    2015-01-01

    Context. Blazars are variable sources on various timescales over a broad energy range spanning from radio to very high energy (>100 GeV, hereafter VHE). Mrk 501 is one of the brightest blazars at TeV energies and has been extensively studied since its first VHE detection in 1996. However, most of the γ-ray studies performed on Mrk 501 during the past years relate to flaring activity, when the source detection and characterization with the available γ-ray instrumentation was easier toperform. Aims. Our goal is to characterize the source γ-ray emission in detail, together with the radio-to-X-ray emission, during the non-flaring (low) activity, which is less often studied than the occasional flaring (high) activity. Methods. We organized a multiwavelength (MW) campaign on Mrk 501 between March and May 2008. This multi-instrument effort included the most sensitive VHE γ-ray instruments in the northern hemisphere, namely the imaging atmospheric Cherenkov telescopes MAGIC and VERITAS, as well as Swift, RXTE, the F-GAMMA, GASP-WEBT, and other collaborations and instruments. This provided extensive energy and temporal coverage of Mrk 501 throughout the entire campaign. Results. Mrk 501 was found to be in a low state of activity during the campaign, with a VHE flux in the range of 10%–20% of the Crab nebula flux. Nevertheless, significant flux variations were detected with various instruments, with a trend of increasing variability with energy and a tentative correlation between the X-ray and VHE fluxes. The broadband spectral energy distribution during the two different emission states of the campaign can be adequately described within the homogeneous one-zone synchrotron self-Compton model, with the (slightly) higher state described by an increase in the electron number density. Conclusions. The one-zone SSC model can adequately describe the broadband spectral energy distribution of the source during the two months covered by the MW campaign. This agrees with

  3. Multiwavelength observations of Mrk 501 in 2008

    Science.gov (United States)

    Aleksić, J.; Ansoldi, S.; Antonelli, L. A.; Antoranz, P.; Babic, A.; Bangale, P.; Barres de Almeida, U.; Barrio, J. A.; Becerra González, J.; Bednarek, W.; Berger, K.; Bernardini, E.; Biland, A.; Blanch, O.; Bock, R. K.; Bonnefoy, S.; Bonnoli, G.; Borracci, F.; Bretz, T.; Carmona, E.; Carosi, A.; Carreto Fidalgo, D.; Colin, P.; Colombo, E.; Contreras, J. L.; Cortina, J.; Covino, S.; da Vela, P.; Dazzi, F.; de Angelis, A.; de Caneva, G.; de Lotto, B.; Delgado Mendez, C.; Doert, M.; Domínguez, A.; Dominis Prester, D.; Dorner, D.; Doro, M.; Einecke, S.; Eisenacher, D.; Elsaesser, D.; Farina, E.; Ferenc, D.; Fonseca, M. V.; Font, L.; Frantzen, K.; Fruck, C.; García López, R. J.; Garczarczyk, M.; Garrido Terrats, D.; Gaug, M.; Giavitto, G.; Godinović, N.; González Muñoz, A.; Gozzini, S. R.; Hadamek, A.; Hadasch, D.; Herrero, A.; Hildebrand, D.; Hose, J.; Hrupec, D.; Idec, W.; Kadenius, V.; Kellermann, H.; Knoetig, M. L.; Krause, J.; Kushida, J.; La Barbera, A.; Lelas, D.; Lewandowska, N.; Lindfors, E.; Lombardi, S.; López, M.; López-Coto, R.; López-Oramas, A.; Lorenz, E.; Lozano, I.; Makariev, M.; Mallot, K.; Maneva, G.; Mankuzhiyil, N.; Mannheim, K.; Maraschi, L.; Marcote, B.; Mariotti, M.; Martínez, M.; Mazin, D.; Menzel, U.; Meucci, M.; Miranda, J. M.; Mirzoyan, R.; Moralejo, A.; Munar-Adrover, P.; Nakajima, D.; Niedzwiecki, A.; Nilsson, K.; Nowak, N.; Orito, R.; Overkemping, A.; Paiano, S.; Palatiello, M.; Paneque, D.; Paoletti, R.; Paredes, J. M.; Paredes-Fortuny, X.; Partini, S.; Persic, M.; Prada, F.; Prada Moroni, P. G.; Prandini, E.; Preziuso, S.; Puljak, I.; Reinthal, R.; Rhode, W.; Ribó, M.; Rico, J.; Rodriguez Garcia, J.; Rügamer, S.; Saggion, A.; Saito, T.; Saito, K.; Salvati, M.; Satalecka, K.; Scalzotto, V.; Scapin, V.; Schultz, C.; Schweizer, T.; Shore, S. N.; Sillanpää, A.; Sitarek, J.; Snidaric, I.; Sobczynska, D.; Spanier, F.; Stamatescu, V.; Stamerra, A.; Steinbring, T.; Storz, J.; Sun, S.; Surić, T.; Takalo, L.; Tavecchio, F.; Temnikov, P.; Terzić, T.; Tescaro, D.; Teshima, M.; Thaele, J.; Tibolla, O.; Torres, D. F.; Toyama, T.; Treves, A.; Uellenbeck, M.; Vogler, P.; Wagner, R. M.; Zandanel, F.; Zanin, R.; MAGIC Collaboration; Behera, B.; Beilicke, M.; Benbow, W.; Berger, K.; Bird, R.; Bouvier, A.; Bugaev, B.; Cerruti, M.; Chen, X.; Ciupik, L.; Collins-Hughes, E.; Cui, W.; Duke, C.; Dumm, J.; Falcone, A.; Federici, S.; Feng, Q.; Finley, J. P.; Fortson, L.; Furniss, A.; Galante, N.; Gillanders, G. H.; Griffin, S.; Griffiths, S. T.; Grube, J.; Gyuk, G.; Hanna, D.; Holder, J.; Johnson, C. A.; Kaaret, P.; Kertzman, M.; Kieda, D.; Krawczynski, H.; Lang, M. J.; Madhavan, A. S.; Maier, G.; Majumdar, P.; Meagher, K.; Moriarty, P.; Mukherjee, R.; Nieto, D.; O'Faoláin de Bhróithe, A.; Ong, R. A.; Otte, A. N.; Pichel, A.; Pohl, M.; Popkow, A.; Prokoph, H.; Quinn, J.; Rajotte, J.; Ratliff, G.; Reyes, L. C.; Reynolds, P. T.; Richards, G. T.; Roache, E.; Sembroski, G. H.; Shahinyan, K.; Sheidaei, F.; Smith, A. W.; Staszak, D.; Telezhinsky, I.; Theiling, M.; Tyler, J.; Varlotta, A.; Vincent, S.; Wakely, S. P.; Weekes, T. C.; Welsing, R.; Williams, D. A.; Zajczyk, A.; Zitzer, B.; VERITAS Collaboration; Villata, M.; Raiteri, C. M.; Ajello, M.; Perri, M.; Aller, H. D.; Aller, M. F.; Larionov, V. M.; Efimova, N. V.; Konstantinova, T. S.; Kopatskaya, E. N.; Chen, W. P.; Koptelova, E.; Hsiao, H. Y.; Kurtanidze, O. M.; Nikolashvili, M. G.; Kimeridze, G. N.; Jordan, B.; Leto, P.; Buemi, C. S.; Trigilio, C.; Umana, G.; Lähteenmäki, A.; Nieppola, E.; Tornikoski, M.; Sainio, J.; Kadenius, V.; Giroletti, M.; Cesarini, A.; Fuhrmann, L.; Kovalev, Yu. A.; Kovalev, Y. Y.

    2015-01-01

    Context. Blazars are variable sources on various timescales over a broad energy range spanning from radio to very high energy (>100 GeV, hereafter VHE). Mrk 501 is one of the brightest blazars at TeV energies and has been extensively studied since its first VHE detection in 1996. However, most of the γ-ray studies performed on Mrk 501 during the past years relate to flaring activity, when the source detection and characterization with the available γ-ray instrumentation was easier toperform. Aims: Our goal is to characterize the source γ-ray emission in detail, together with the radio-to-X-ray emission, during the non-flaring (low) activity, which is less often studied than the occasional flaring (high) activity. Methods: We organized a multiwavelength (MW) campaign on Mrk 501 between March and May 2008. This multi-instrument effort included the most sensitive VHE γ-ray instruments in the northern hemisphere, namely the imaging atmospheric Cherenkov telescopes MAGIC and VERITAS, as well as Swift, RXTE, the F-GAMMA, GASP-WEBT, and other collaborations and instruments. This provided extensive energy and temporal coverage of Mrk 501 throughout the entire campaign. Results: Mrk 501 was found to be in a low state of activity during the campaign, with a VHE flux in the range of 10%-20% of the Crab nebula flux. Nevertheless, significant flux variations were detected with various instruments, with a trend of increasing variability with energy and a tentative correlation between the X-ray and VHE fluxes. The broadband spectral energy distribution during the two different emission states of the campaign can be adequately described within the homogeneous one-zone synchrotron self-Compton model, with the (slightly) higher state described by an increase in the electron number density. Conclusions: The one-zone SSC model can adequately describe the broadband spectral energy distribution of the source during the two months covered by the MW campaign. This agrees with previous

  4. Simultaneous multi-wavelength observations of GRS 1915+105

    DEFF Research Database (Denmark)

    Fuchs, Y.; Rodriguez, Cayo Juan Ramos; Mirabel, I.F.

    2003-01-01

    We present the result of multi-wavelength observations of the microquasar GRS 1915 + 105 in a plateau state with a luminosity of similar to7.5 x 10(38) erg s(-1) (similar to40% L-Edd), conducted simultaneously with the INTEGRAL and RXTE satellites, the ESOstarstar/NTT, the Ryle Telescope, the NRAO......(starstarstar) VLA and VLBA, in 2003 April 2-3. For the first time were observed concurrently in GRS 1915 + 105 all of the following properties: a strong steady optically thick radio emission corresponding to a powerful compact jet resolved with the VLBA, bright near-IR emission, a strong QPO at 2.5 Hz in the X...

  5. Detectability of Galactic Faraday Rotation in multiwavelength CMB observations

    Science.gov (United States)

    Kolopanis, Matthew; Mauskopf, Philip; Bowman, Judd

    2018-02-01

    We introduce a new cross-correlation method to detect and verify the astrophysical origin of Faraday Rotation (FR) in multiwavelength surveys. FR is well studied in radio astronomy from radio point sources but the λ2 suppression of FR makes detecting and accounting for this effect difficult at millimeter and sub-millimeter wavelengths. Therefore, statistical methods are used to attempt to detect FR in the cosmic microwave background (CMB). Most estimators of the FR power spectrum rely on single-frequency data. In contrast, we investigate the correlation of polarized CMB maps with FR measure maps from radio point sources. We show a factor of ∼30 increase in sensitivity over single-frequency estimators and predict detections exceeding 10σ significance for a CMB-S4-like experiment. Improvements in observations of FR from current and future radio polarization surveys will greatly increase the usefulness of this method.

  6. Comparing soil functions for a wide range of agriculture soils focusing on production for bioenergy using a combined isotope-based observation and modelling approach

    Science.gov (United States)

    Leistert, Hannes; Herbstritt, Barbara; Weiler, Markus

    2017-04-01

    Increase crop production for bioenergy will result in changes in land use and the resulting soil functions and may generate new chances and risks. However, detailed data and information are still missing how soil function may be altered under changing crop productions for bioenergy, in particular for a wide range of agricultural soils since most data are currently derived from individual experimental sites studying different bioenergy crops at one location. We developed a new, rapid measurement approach to investigate the influence of bioenergy plants on the water cycle and different soil functions (filter and buffer of water and N-cycling). For this approach, we drilled 89 soil cores (1-3 m deep) in spring and fall at 11 sites with different soil properties and climatic conditions comparing different crops (grass, corn, willow, poplar, and other less common bioenergy crops) and analyzing 1150 soil samples for water content, nitrate concentration and stable water isotopes. We benchmarked a soil hydrological model (1-D numerical Richards equation, ADE, water isotope fractionation including liquid and vapor composition of isotopes) using longer-term climate variables and water isotopes in precipitation to derive crop specific parameterization and to specifically validate the differences in water transport and water partitioning into evaporation, transpiration and groundwater recharge among the sites and crops using the water isotopes in particular. The model simulation were in good agreement with the observed isotope profiles and allowed us to differentiate among the different crops. We defined different indicators for the soil functions considered in this study. These indicators included the proportion of groundwater recharge, transit time of water (different percentiles) though the upper 2m and nutrient leaching potential (e.g. nitrate) during the dormant season from the rooting zone. The parameterized model was first used to calculate the indicators for the

  7. Multi-wavelength observations of pulsar wind nebulae and composite supernova remnants

    Science.gov (United States)

    Temim, Tea

    Multi-wavelength studies of pulsar wind nebulae (PWNe) and supernova remnants (SNRs) lead to a better understanding of their evolutionary development, the interaction of supernovae (SNe) and pulsar winds with their surroundings, and nucleosynthesis and production and processing of dust grains by SNe. PWNe and composite supernova remnants, in particular, are unique laboratories for the study of the energetic pulsar winds, particle injection processes, and the impact of PWNe on the evolving SNR. They provide information on SNR shock properties, densities and temperatures, and the chemical composition and the ionization state of the material ejected by SNe. SNRs also serve as laboratories for the study of dust production and processing in SNe. While X-ray observations yield important information about the SN progenitor, hot gas properties, SN explosion energy, and the surrounding interstellar medium (ISM), the IR can provide crucial information about the faint non-thermal emission, continuum emission from dust, and forbidden line emission from SN ejecta. Combining observations at a wide range of wavelengths provides a more complete picture of the SNR development and helps better constrain current models describing a SNR's evolution and its impact on the surrounding medium. This thesis focuses on a multi-wavelength study of PWNe in various stages of their evolution and investigates their interaction with the expanding SN ejecta and dust and the SNR reverse shock. The study of these interactions can provide important information on the SNR properties that may otherwise be unobservable. The work in this thesis has been carried out under the supervision of Patrick Slane at the Harvard-Smithsonian Center for Astrophysics, and Charles E. Woodward and Rebert D. Gehrz at the University of Minnesota. The first part of the thesis summarizes the evolution and observational properties of SNRs and PWNe, with a focus on the evolution of young PWNe that are sweeping up inner SN

  8. Using the Autism Diagnostic Interview-Revised and the Autism Diagnostic Observation Schedule-Generic for the diagnosis of autism spectrum disorders in a Greek sample with a wide range of intellectual abilities.

    Science.gov (United States)

    Papanikolaou, Katerina; Paliokosta, Elena; Houliaras, Giorgos; Vgenopoulou, Sofia; Giouroukou, Eleni; Pehlivanidis, Artemios; Tomaras, Vlassis; Tsiantis, Ioannis

    2009-03-01

    We studied the interrelationship between the Autism Diagnostic Observation Schedule-Generic (ADOS-G), the Autism Diagnostic Interview-Revised (ADI-R) and DSM-IV clinical diagnosis, in a Greek sample of 77 children and adolescents, referred for the assessment of a possible pervasive developmental disorder (PDD) and presenting a wide range of cognitive abilities. The agreement of the ADOS-G and the ADI-R with the clinical diagnosis was estimated as satisfactory and moderate, respectively, while both instruments presented with excellent sensitivity for the diagnosis of autistic disorder along with satisfactory specificity. ADOS-G/ADI-R agreement was estimated as fair. Our results confirm the discriminant validity of ADI-R and ADOS-G in diagnosing pervasive developmental disorders in children and adolescents with a wide range of intellectual abilities.

  9. Multiwavelength observations of the Type IIb supernova 2009mg

    DEFF Research Database (Denmark)

    Oates, S. R.; Bayless, A. J.; Stritzinger, M. D.

    2012-01-01

    We present Swift Ultra-Violet Optical Telescope and X-Ray Telescope (XRT) observations, and visual wavelength spectroscopy of the Type IIb supernova (SN) 2009mg, discovered in the Sb galaxy ESO 121-G26. The observational properties of SN 2009mg are compared to the prototype Type IIb SNe 1993J...

  10. Characterizing Abundances of Volatiles in Comets Through Multiwavelength Observations

    Science.gov (United States)

    Milam, Stefanie N.; Charnley, Steven B.; Kuan, Yi-Jehng; Chuang, Yo-Ling; DiSanti, Michael A.; Bonev, Boncho P.; Remijan, Anthony J.; Coulson, Iain; Haynes, Lillian; Stenborg, Maria

    2012-01-01

    Recently, there have been complimentary observations from multiple facilities to try to unravel the chemical complexity of comets. Incorporating results from various techniques, including: single-dish millimeter wavelength observations, interferometers, and/or IR spectroscopy, one can gain further insight into the abundances, production rates, distributions, and formation mechanisms of molecules in these objects [I]. Such studies have provided great detail towards molecules with a-typical chemistries, such as H2CO [2]. We report spectral observations of C/2007 N3 (Lulin), C/2009 R1 (McNaught), 103P/Hartley 2, and C/2009 P1 (Garradd) with the Arizona Radio Observatory's SMT and 12-m telescopes, as well as the NRAO Greenbank telescope and IRTF-CSHELL. Multiple parent volatiles (HCN, CH3OH, CO, CH4, C2H6, and H2O) as well as a number of daughter products (CS and OH) have been detected in these objects. We will present a comparison of molecular abundances in these comets to those observed in others, supporting a long-term effort of building a comet taxonomy based on composition. Previous work has revealed a range of abundances of parent species (from "organics-poor" to "organics-rich") with respect to water among comets [3,4,5], however the statistics are still poorly constrained and interpretations of the observed compositional diversity are uncertain. We gratefully acknowledge support from the NSF Astronomy and Astrophysics Program, the NASA Planetary Astronomy Program, NASA Planetary Atmospheres Program, and the NASA Astrobiology Program.

  11. Central Asian Dust Experiment (CADEX: Multiwavelength Polarization Raman Lidar Observations in Tajikistan

    Directory of Open Access Journals (Sweden)

    Hofer Julian

    2016-01-01

    Full Text Available For the first time lidar measurements of vertical aerosol profiles are conducted in Tajikistan/Central Asia. These measurements just started on March 17th, 2015. They are performed within the Central Asian Dust Experiment (CADEX in Dushanbe and they will last at least one year. The deployed system for these observations is an updated version of the multiwavelength polarization Raman lidar PollyXT. Vertical profiles of the backscatter coefficient, the extinction coefficient, and the particle depolarization ratio are measured by this instrument. A first and preliminary measurement example of an aerosol layer over Dushanbe is shown.

  12. Multiwavelength Observations of a TeV-Flare from W Comae

    Science.gov (United States)

    Acciari, V. A.; Aliu, E.; Aune, T.; Beilicke, M.; Benbow, W.; Böttcher, M.; Boltuch, D.; Buckley, J. H.; Bradbury, S. M.; Bugaev, V.; Byrum, K.; Cannon, A.; Cesarini, A.; Ciupik, L.; Cogan, P.; Cui, W.; Dickherber, R.; Duke, C.; Falcone, A.; Finley, J. P.; Fortin, P.; Fortson, L.; Furniss, A.; Galante, N.; Gall, D.; Gibbs, K.; Gillanders, G. H.; Grube, J.; Guenette, R.; Gyuk, G.; Hanna, D.; Holder, J.; Hui, C. M.; Humensky, T. B.; Kaaret, P.; Karlsson, N.; Kertzman, M.; Kieda, D.; Konopelko, A.; Krawczynski, H.; Krennrich, F.; Lang, M. J.; Le Bohec, S.; Maier, G.; McArthur, S.; McCann, A.; McCutcheon, M.; Millis, J.; Moriarty, P.; Ong, R. A.; Otte, A. N.; Pandel, D.; Perkins, J. S.; Pichel, A.; Pohl, M.; Quinn, J.; Ragan, K.; Reyes, L. C.; Reynolds, P. T.; Roache, E.; Rose, H. J.; Sembroski, G. H.; Smith, A. W.; Steele, D.; Theiling, M.; Thibadeau, S.; Varlotta, A.; Vassiliev, V. V.; Vincent, S.; Wakely, S. P.; Ward, J. E.; Weekes, T. C.; Weinstein, A.; Weisgarber, T.; Williams, D. A.; Wissel, S.; Wood, M.; Pian, E.; Vercellone, S.; Donnarumma, I.; D'Ammando, F.; Bulgarelli, A.; Chen, A. W.; Giuliani, A.; Longo, F.; Pacciani, L.; Pucella, G.; Vittorini, V.; Tavani, M.; Argan, A.; Barbiellini, G.; Caraveo, P.; Cattaneo, P. W.; Cocco, V.; Costa, E.; Del Monte, E.; De Paris, G.; Di Cocco, G.; Evangelista, Y.; Feroci, M.; Fiorini, M.; Froysland, T.; Frutti, M.; Fuschino, F.; Galli, M.; Gianotti, F.; Labanti, C.; Lapshov, I.; Lazzarotto, F.; Lipari, P.; Marisaldi, M.; Mastropietro, M.; Mereghetti, S.; Morelli, E.; Morselli, A.; Pellizzoni, A.; Perotti, F.; Piano, G.; Picozza, P.; Pilia, M.; Porrovecchio, G.; Prest, M.; Rapisarda, M.; Rappoldi, A.; Rubini, A.; Sabatini, S.; Soffitta, P.; Trifoglio, M.; Trois, A.; Vallazza, E.; Zambra, A.; Zanello, D.; Pittori, C.; Santolamazza, P.; Verrecchia, F.; Giommi, P.; Colafrancesco, S.; Salotti, L.; Villata, M.; Raiteri, C. M.; Aller, H. D.; Aller, M. F.; Arkharov, A. A.; Efimova, N. V.; Larionov, V. M.; Leto, P.; Ligustri, R.; Lindfors, E.; Pasanen, M.; Kurtanidze, O. M.; Tetradze, S. D.; Lahteenmaki, A.; Kotiranta, M.; Cucchiara, A.; Romano, P.; Nesci, R.; Pursimo, T.; Heidt, J.; Benitez, E.; Hiriart, D.; Nilsson, K.; Berdyugin, A.; Mujica, R.; Dultzin, D.; Lopez, J. M.; Mommert, M.; Sorcia, M.; de la Calle Perez, I.

    2009-12-01

    We report results from an intensive multiwavelength campaign on the intermediate-frequency-peaked BL Lacertae object W Com (z = 0.102) during a strong outburst of very high energy gamma-ray emission in 2008 June. The very high energy gamma-ray signal was detected by VERITAS on 2008 June 7-8 with a flux F(>200 GeV) =(5.7 ± 0.6) × 10-11 cm-2 s-1, about three times brighter than during the discovery of gamma-ray emission from W Com by VERITAS in 2008 March. The initial detection of this flare by VERITAS at energies above 200 GeV was followed by observations in high-energy gamma rays (AGILE; E γ>= 100 MeV), X-rays (Swift and XMM-Newton), and at UV, and ground-based optical and radio monitoring through the GASP-WEBT consortium and other observatories. Here we describe the multiwavelength data and derive the spectral energy distribution of the source from contemporaneous data taken throughout the flare.

  13. Multiwavelength observations of black hole and neutron star X-ray binaries

    Science.gov (United States)

    Jain, Raj Kumar

    X-ray novae (XNe) are binary systems in which matter is transferred from the companion star onto the compact object through an accretion flow. Besides providing the most compelling evidence for the existence of black holes, XNe present rare opportunities to test general relativity in the strong field limit. Multiwavelength observations, and in particular the correlated features of the multiwavelength light curves, lead to unique information about the accretion geometry, underlying radiative mechanisms, and relevant physical time-scales. The goal of this thesis is to provide extensive multiwavelength observations of XNe, covering entire outburst cycles, which present quantitative challenges to existing theories. By using instruments designed to conduct long term monitoring of XNe, namely the Rossi X ray Timing Explorer (RXTE) satellite and the Yale 1-m telescope (operated by the YALO consortium), we closely studied a black hole XN XTE J1550-564 and a neutron star XN Aquila X-1 in the optical/IR and X-ray wavelengths. We discovered the optical counterpart of XTE J1550 564, measured a preliminary value for its orbital period, detected several correlations and delays between features in the optical and X-ray light, and obtained the first extensive IR light curve from a black hole XN covering an entire outburst cycle. Similarly, we found delays and correlations in the light curves of Aquila X-1. Periodic signatures were found throughout the outburst. Contrary to prior knowledge, we find a ˜2% shorter period during the outburst rise, compared to the value during full outburst. We have also succeeded, for the first time, in triggering pointed RXTE observations of an XN based on the detection of the optical outburst, which typically precedes the X-ray outburst by a week or so. We proposed qualitative explanations for these observations, which, in the absence of detailed theoretical models, serves as a starting point for further theoretical endeavors. The outburst optical

  14. Multi-wavelength observations of the powerful gamma-ray blazar PKS 1510-089

    Science.gov (United States)

    D'Ammando, F.; Vercellone, S.; Donnarumma, I.; Bulgarelli, A.; Chen, A.; Giuliani, A.; Longo, F.; Pacciani, L.; Pucella, G.; Vittorini, V.; Raiteri, C. M.; Villata, M.; Romano, P.; Krimm, H. A.; Covino, S.

    2010-07-01

    PKS 1510-089 is a Flat Spectrum Radio Quasar at z = 0.361 with radiative output dominated by the γ-ray component and high variability over the whole electromagnetic spectrum. In particular, in the last two years very high γ-ray activity was detected by AGILE with flaring episodes in August 2007 and March 2008 and an extraordinary activity during March 2009. Observations in optical/UV seems to indicate the presence of Seyfert-like features in the broad band spectrum of PKS 1510-089, such as the little and big blue bumps. Moreover, X-ray observations in March 2008 show a harder-when-brighter behaviour quite rare in FSRQs. We present the multiwavelength data of PKS 1510-089 collected by GASP-WEBT, REM, Swift and AGILE during these γ-ray flares.

  15. Multiwavelength observations of the candidate disintegrating sub-Mercury KIC 12557548B , ,

    Energy Technology Data Exchange (ETDEWEB)

    Croll, Bryce; Rappaport, Saul; Levine, Alan M. [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); DeVore, John [Visidyne, Inc., Santa Barbara, CA 93105 (United States); Gilliland, Ronald L.; Star, Kimberly M. [Center for Exoplanets and Habitable Worlds, The Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Crepp, Justin R. [Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46556 (United States); Howard, Andrew W. [Institute for Astronomy, University of Hawaii at Manoa, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Chiang, Eugene [Departments of Astronomy and of Earth and Planetary Science, University of California at Berkeley, Hearst Field Annex B-20, Berkeley, CA 94720-3411 (United States); Jenkins, Jon M. [SETI Institute/NASA Ames Research Center, M/S 244-30, Moffett Field, CA 94035 (United States); Albert, Loic [Département de physique, Université de Montréal, C.P. 6128 Succ. Centre-Ville, Montréal, QC H3C 3J7 (Canada); Bonomo, Aldo S. [INAF-Osservatorio Astrofisico di Torino, via Osservatorio 20, I-10025 Pino Torinese (Italy); Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Isaacson, Howard, E-mail: croll@space.mit.edu [Department of Astronomy, University of California, Berkeley, CA 94720 (United States)

    2014-05-10

    We present multiwavelength photometry, high angular resolution imaging, and radial velocities of the unique and confounding disintegrating low-mass planet candidate KIC 12557548b. Our high angular resolution imaging, which includes space-based Hubble Space Telescope Wide Field Camera 3 (HST/WFC3) observations in the optical (∼0.53 μm and ∼0.77 μm), and ground-based Keck/NIRC2 observations in K' band (∼2.12 μm), allow us to rule out background and foreground candidates at angular separations greater than 0.''2 that are bright enough to be responsible for the transits we associate with KIC 12557548. Our radial velocity limit from Keck/HIRES allows us to rule out bound, low-mass stellar companions (∼0.2 M {sub ☉}) to KIC 12557548 on orbits less than 10 yr, as well as placing an upper limit on the mass of the candidate planet of 1.2 Jupiter masses; therefore, the combination of our radial velocities, high angular resolution imaging, and photometry are able to rule out most false positive interpretations of the transits. Our precise multiwavelength photometry includes two simultaneous detections of the transit of KIC 12557548b using Canada-France-Hawaii Telescope/Wide-field InfraRed Camera (CFHT/WIRCam) at 2.15 μm and the Kepler space telescope at 0.6 μm, as well as simultaneous null-detections of the transit by Kepler and HST/WFC3 at 1.4 μm. Our simultaneous HST/WFC3 and Kepler null-detections provide no evidence for radically different transit depths at these wavelengths. Our simultaneous CFHT/WIRCam detections in the near-infrared and with Kepler in the optical reveal very similar transit depths (the average ratio of the transit depths at ∼2.15 μm compared with ∼0.6 μm is: 1.02 ± 0.20). This suggests that if the transits we observe are due to scattering from single-size particles streaming from the planet in a comet-like tail, then the particles must be ∼0.5 μm in radius or larger, which would favor that KIC 12557548b is a sub

  16. MULTIWAVELENGTH OBSERVATIONS AND MODELING OF 1ES 1959+650 IN A LOW FLUX STATE

    Energy Technology Data Exchange (ETDEWEB)

    Aliu, E.; Errando, M. [Department of Physics and Astronomy, Barnard College, Columbia University, NY 10027 (United States); Archambault, S. [Physics Department, McGill University, Montreal, QC H3A 2T8 (Canada); Arlen, T.; Aune, T. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Beilicke, M.; Bugaev, V.; Dickherber, R. [Department of Physics, Washington University, St. Louis, MO 63130 (United States); Benbow, W. [Fred Lawrence Whipple Observatory, Harvard-Smithsonian Center for Astrophysics, Amado, AZ 85645 (United States); Bird, R.; Collins-Hughes, E. [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Boettcher, M. [Astrophysical Institute, Department of Physics and Astronomy, Ohio University, Athens, OH 45701 (United States); Bouvier, A. [Santa Cruz Institute for Particle Physics and Department of Physics, University of California, Santa Cruz, CA 95064 (United States); Byrum, K. [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Cesarini, A.; Connolly, M. P. [School of Physics, National University of Ireland Galway, University Road, Galway (Ireland); Ciupik, L. [Astronomy Department, Adler Planetarium and Astronomy Museum, Chicago, IL 60605 (United States); Cui, W. [Department of Physics, Purdue University, West Lafayette, IN 47907 (United States); Duke, C. [Department of Physics, Grinnell College, Grinnell, IA 50112-1690 (United States); Dumm, J. [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States); and others

    2013-09-20

    We report on the VERITAS observations of the high-frequency peaked BL Lac object 1ES 1959+650 in the period 2007-2011. This source is detected at TeV energies by VERITAS at 16.4 standard deviation ({sigma}) significance in 7.6 hr of observation in a low flux state. A multiwavelength spectral energy distribution (SED) is constructed from contemporaneous data from VERITAS, Fermi-LAT, RXTE PCA, and Swift UVOT. Swift XRT data is not included in the SED due to a lack of simultaneous observations with VERITAS. In contrast to the orphan {gamma}-ray flare exhibited by this source in 2002, the X-ray flux of the source is found to vary by an order of magnitude, while other energy regimes exhibit less variable emission. A quasi-equilibrium synchrotron self-Compton model with an additional external radiation field is used to describe three SEDs corresponding to the lowest, highest, and average X-ray states. The variation in the X-ray spectrum is modeled by changing the electron injection spectral index, with minor adjustments of the kinetic luminosity in electrons. This scenario produces small-scale flux variability of the order of {approx}< 2 in the high energy (E > 1 MeV) and very high energy (E > 100 GeV) {gamma}-ray regimes, which is corroborated by the Fermi-LAT, VERITAS, and Whipple 10 m telescope light curves.

  17. Multiwavelength Observations of Markarian 421 During a TeV/X-Ray Flare

    Science.gov (United States)

    Bertsch, D. L.; Bruhweiler, F.; Macomb, D. J.; Cheng, K.-P.; Carter-Lewis, D. A.; Akerlof, C. W.; Aller, H. D.; Aller, M. F.; Buckley, J. H.; Cawley, M. F.

    1995-01-01

    A TeV flare from the BL Lac object Mrk 421 was detected in May of 1994 by the Whipple Observatory air Cherenkov experiment during which the flux above 250 GeV increased by nearly an order of magnitude over a 2-day period. Contemporaneous observations by ASCA showed the X-ray flux to be in a very high state. We present these results, combined with the first ever simultaneous or nearly simultaneous observations at GeV gamma-ray, UV, IR, mm, and radio energies for this nearest BL Lac object. While the GeV gamma-ray flux increased slightly, there is little evidence for variability comparable to that seen at TeV and X-ray energies. Other wavelengths show even less variability. This provides important constraints on the emission mechanisms at work. We present the multiwavelength spectrum of this gamma-ray blazar for both quiescent and flaring states and discuss the data in terms of current models of blazar emission.

  18. Multi-wavelength Observations of Solar Acoustic Waves Near Active Regions

    Science.gov (United States)

    Monsue, Teresa; Pesnell, Dean; Hill, Frank

    2018-01-01

    Active region areas on the Sun are abundant with a variety of waves that are both acoustically helioseismic and magnetohydrodynamic in nature. The occurrence of a solar flare can disrupt these waves, through MHD mode-mixing or scattering by the excitation of these waves. We take a multi-wavelength observational approach to understand the source of theses waves by studying active regions where flaring activity occurs. Our approach is to search for signals within a time series of images using a Fast Fourier Transform (FFT) algorithm, by producing multi-frequency power map movies. We study active regions both spatially and temporally and correlate this method over multiple wavelengths using data from NASA’s Solar Dynamics Observatory. By surveying the active regions on multiple wavelengths we are able to observe the behavior of these waves within the Solar atmosphere, from the photosphere up through the corona. We are able to detect enhancements of power around active regions, which could be acoustic power halos and of an MHD-wave propagating outward by the flaring event. We are in the initial stages of this study understanding the behaviors of these waves and could one day contribute to understanding the mechanism responsible for their formation; that has not yet been explained.

  19. Simultaneous, multi-wavelength flare observations of nearby low-mass stars

    Science.gov (United States)

    Thackeray, Beverly; Barclay, Thomas; Quintana, Elisa; Villadsen, Jacqueline; Wofford, Alia; Schlieder, Joshua; Boyd, Patricia

    2018-01-01

    Low-mass stars are the most common stars in the Galaxy and have been targeted in the tens-of-thousands by K2, the re-purposed Kepler mission, as they are prime targets to search for and characterize small, Earth-like planets. Understanding how these fully convective stars drive magnetic activity that manifests as stochastic, short-term brightenings, or flares, provides insight into the prospects of planetary habitability. High energy radiation and energetic particle emission associated with these stars can erode atmospheres, and impact habitability. An innovative campaign to study low mass stars through simultaneous multi-wavelength observations is currently underway with observations ongoing in the X-ray, UV, optical, and radio. I will present early results of our pilot study of the nearby M-Dwarf star Wolf 359 (CN Leo) using K2, SWIFT, and ground based radio observatories, forming a comprehensive picture of flare activity from an M-Dwarf, and discuss the potential impact of these results on exoplanets. "This material is based upon work supported by the National Science Foundation Graduate Research Fellowship Program under Grant No. DGE1322106. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation."

  20. State-of-the-art multi-wavelength observations of nearby brightest group/cluster galaxies

    Science.gov (United States)

    Gendron-Marsolais, Marie-Lou; Hlavacek-Larrondo, Julie

    2018-01-01

    Nearby galaxy groups and clusters are crucial to our understanding of the impact of nuclear outbursts on the intracluster medium as their proximity allows us to study in detail the processes of feedback from active galactic nuclei in these systems. In this talk, I will present state-of-the-art multi-wavelength observations signatures of this mechanism.I will first show results on multi-configuration 230-470 MHz observations of the Perseus cluster from the Karl G. Jansky Very Large Array, probing the non-thermal emission from the old particle population of the AGN outflows. These observations reveal a multitude of new structures associated with the “mini-halo” and illustrate the high-quality images that can be obtained with the new JVLA at low radio-frequencies.Second, I will present new observations with the optical imaging Fourier transform spectrometer SITELLE (CFHT) of NGC 1275, the Perseus cluster's brightest galaxy. With its wide field of view, it is the only integral field unit spectroscopy instrument able to cover the large emission-line filamentary nebula in NGC 1275. I will present the first detailed velocity map of this nebula in its entirety and tackle the question of its origin (residual cooling flow or dragged gas).Finally, I will present deep Chandra observations of the nearby early-type massive elliptical galaxy NGC 4472, the most optically luminous galaxy in the local Universe, lying on the outskirts of the Virgo cluster. Enhanced X-ray rims around the radio lobes are detected and interpreted as gas uplifted from the core by the buoyant rise of the radio bubbles. We estimate the energy required to lift the gas to constitute a significant fraction of the total outburst energy.I will thus show how these high-fidelity observations of nearby brightest group/cluster galaxies are improving our understanding of the AGN feedback mechanism taking place in galaxy groups and clusters.

  1. Multi-Wavelength Near Infrared Observations of Marum and Yasur Volcanoes, Vanuatu

    Science.gov (United States)

    Howell, Robert R.; Radebaugh, Jani; Lopes, Rosaly M.; Lorenz, Ralph D.; Turtle, Elizabeth P.

    2014-11-01

    To help understand and test models of thermal emission from planetary volcanoes, we obtained in May 2014 a variety of near-infrared observations of the very active Marum lava lake on Ambrym, Vanuatu, as well as the Strombolian activity at Yasur on Tanna. Our observations include high resolution images and movies made with standard and modified cameras and camcorders. In addition, to test the planetary emission models, which typically rely on multi-wavelength observations, we developed a small inexpensive prototype imager named "Kerby", which consists of three simultaneously active near-infrared cameras operating at 0.860, 0.775, and 0.675 microns, as well as a fourth visible wavelength RGB camera. This prototype is based on the Raspberry Pi and Pi-NoIR cameras. It can record full high definition video, and is light enough to be carried by backpack and run from batteries. To date we have concentrated on the analysis of the Marum data. During our observations of the 40 m diameter lava lake, convection was so vigorous that areas of thin crust formed only intermittently and persisted for tens of seconds to a few minutes at most. The convection pattern primarily consisted of two upwelling centers located about 8 m in from the margins on opposite sides of the lake. Horizontal velocities away from the upwelling centers were approximately 4 m/s. A hot bright margin roughly 0.4 m wide frequently formed around parts of the lake perimeter. We are in the process of establishing the absolute photometry calibration to obtain temperatures, temperature distributions, and magma cooling rates.

  2. A Study of Massive Star Evolution and Mass Loss With Multi-Wavelength Observations of Type IIn Supernovae

    Science.gov (United States)

    Fox, Ori; Skrutskie, Michael; Chevalier, Roger; Smith, Nathan; Chandra, Poonam; Filippenko, Alex

    2012-12-01

    Type IIn supernovae (SNe IIn) are a rare (list of subclasses, suggesting multiple progenitors may be responsible. Multi-wavelength observations, spanning the X-ray to the infrared (IR) to the radio regime, can probe various aspects of shock interaction and dust formation associated with the dense CSM for months to years after the radioactive emission fades. Such diagnostics probe the progenitor mass-loss history, CSM characteristics, and even the elusive SN shock breakout. Given the required coordination amongst space-based and large ground-based telescopes, however, existing data sets are sparse and insufficient. Here we submit a joint Spitzer/Chandra proposal to trace the mass-loss history of SNe IIn with a thorough, coordinated, multi-wavelength approach. With guaranteed time on Keck and JVLA already at our disposal and an aligned team of SNe IIn experts spanning all wavelengths, now is the time for such a program.

  3. Multiwavelength Observations of 3C 454.3. II. The AGILE 2007 December Campaign

    Science.gov (United States)

    Donnarumma, I.; Pucella, G.; Vittorini, V.; D'Ammando, F.; Vercellone, S.; Raiteri, C. M.; Villata, M.; Perri, M.; Chen, W. P.; Smart, R. L.; Kataoka, J.; Kawai, N.; Mori, Y.; Tosti, G.; Impiombato, D.; Takahashi, T.; Sato, R.; Tavani, M.; Bulgarelli, A.; Chen, A. W.; Giuliani, A.; Longo, F.; Pacciani, L.; Argan, A.; Barbiellini, G.; Boffelli, F.; Caraveo, P.; Cattaneo, P. W.; Cocco, V.; Contessi, T.; Costa, E.; Del Monte, E.; De Paris, G.; Di Cocco, G.; Evangelista, Y.; Feroci, M.; Ferrari, A.; Fiorini, M.; Froysland, T.; Frutti, M.; Fuschino, F.; Galli, M.; Gianotti, F.; Labanti, C.; Lapshov, I.; Lazzarotto, F.; Lipari, P.; Marisaldi, M.; Mastropietro, M.; Mereghetti, S.; Morelli, E.; Moretti, E.; Morselli, A.; Pellizzoni, A.; Perotti, F.; Piano, G.; Picozza, P.; Pilia, M.; Porrovecchio, G.; Prest, M.; Rapisarda, M.; Rappoldi, A.; Rubini, A.; Sabatini, S.; Scalise, E.; Soffitta, P.; Striani, E.; Trifoglio, M.; Trois, A.; Vallazza, E.; Zambra, A.; Zanello, D.; Pittori, C.; Santolamazza, P.; Verrecchia, F.; Giommi, P.; Antonelli, L. A.; Colafrancesco, S.; Salotti, L.

    2009-12-01

    We report on the second Astrorivelatore Gamma a Immagini Leggero (AGILE) multiwavelength campaign of the blazar 3C 454.3 during the first half of 2007 December. This campaign involved AGILE, Spitzer, Swift, Suzaku, the Whole Earth Blazar Telescope (WEBT) consortium, the Rapid Eye Mount (REM), and the Multicolor Imaging Telescopes for Survey and Monstrous Explosions (MITSuME) telescopes, offering a broadband coverage that allowed for a simultaneous sampling of the synchrotron and inverse Compton (IC) emissions. The two-week AGILE monitoring was accompanied by radio to optical monitoring by WEBT and REM, and by sparse observations in mid-infrared and soft/hard X-ray energy bands performed by means of Target of Opportunity observations by Spitzer, Swift, and Suzaku, respectively. The source was detected with an average flux of ~250 × 10-8 photons cm-2 s-1 above 100 MeV, typical of its flaring states. The simultaneous optical and γ-ray monitoring allowed us to study the time lag associated with the variability in the two energy bands, resulting in a possible lsimone-day delay of the γ-ray emission with respect to the optical one. From the simultaneous optical and γ-ray fast flare detected on December 12, we can constrain the delay between the γ-ray and optical emissions within 12 hr. Moreover, we obtain three spectral energy distributions (SEDs) with simultaneous data for 2007 December 5, 13, and 15, characterized by the widest multifrequency coverage. We found that a model with an external Compton on seed photons by a standard disk and reprocessed by the broad-line regions does not describe in a satisfactory way the SEDs of 2007 December 5, 13, and 15. An additional contribution, possibly from the hot corona with T = 106 K surrounding the jet, is required to account simultaneously for the softness of the synchrotron and the hardness of the IC emissions during those epochs.

  4. Wide Range Multiscale Entropy Changes through Development

    Directory of Open Access Journals (Sweden)

    Nicola R. Polizzotto

    2015-12-01

    Full Text Available How variability in the brain’s neurophysiologic signals evolves during development is important for a global, system-level understanding of brain maturation and its disturbance in neurodevelopmental disorders. In the current study, we use multiscale entropy (MSE, a measure that has been related to signal complexity, to investigate how this variability evolves during development across a broad range of temporal scales. We computed MSE, standard deviation (STD and standard spectral analyses on resting EEG from 188 healthy individuals aged 8–22 years old. We found age-related increases in entropy at lower scales (<~20 ms and decreases in entropy at higher scales (~60–80 ms. Decreases in the overall signal STD were anticorrelated with entropy, especially in the lower scales, where regression analyses showed substantial covariation of observed changes. Our findings document for the first time the scale dependency of developmental changes from childhood to early adulthood, challenging a parsimonious MSE-based account of brain maturation along a unidimensional, complexity measure. At the level of analysis permitted by electroencephalography (EEG, MSE could capture critical spatiotemporal variations in the role of noise in the brain. However, interpretations critically rely on defining how signal STD affects MSE properties.

  5. Multiwavelength Observations of the Gamma-Ray Blazar PKS 0528+134 in Quiescence

    Science.gov (United States)

    Palma, N. I.; Böttcher, M.; de la Calle, I.; Agudo, I.; Aller, M.; Aller, H.; Bach, U.; Benítez, E.; Buemi, C. S.; Escande, L.; Gómez, J. L.; Gurwell, M. A.; Heidt, J.; Hiriart, D.; Jorstad, S. G.; Joshi, M.; Lähteenmäki, A.; Larionov, V. M.; Leto, P.; Li, Y.; López, J. M.; Lott, B.; Madejski, G.; Marscher, A. P.; Morozova, D. A.; Raiteri, C. M.; Roberts, V.; Tornikoski, M.; Trigilio, C.; Umana, G.; Villata, M.; Wylezalek, D.

    2011-07-01

    We present multiwavelength observations of the ultraluminous blazar-type radio loud quasar PKS 0528+134 in quiescence during the period 2009 July-December. Four Target-of-Opportunity observations with the XMM-Newton satellite in the 0.2-10 keV range were supplemented with optical observations at the MDM Observatory, radio and optical data from the GLAST-AGILE Support Program of the Whole Earth Blazar Telescope and the Very Long Baseline Array, additional X-ray data from the Rossi X-ray Timing Explorer (2-10 keV) and from Suzaku (0.5-10 keV) as well as γ-ray data from the Fermi Large Area Telescope in the 100 MeV-200 GeV range. In addition, publicly available data from the SMARTS blazar monitoring program and the University of Arizona/Steward Observatory Fermi Support program were included in our analysis. We found no evidence of significant flux or spectral variability in γ-rays and most radio bands. However, significant flux variability on a timescale of several hours was found in the optical regime, accompanied by a weak trend of spectral softening with increasing flux. We suggest that this might be the signature of a contribution of unbeamed emission, possibly from the accretion disk, at the blue end of the optical spectrum. The optical flux is weakly polarized with rapid variations of the degree and direction of polarization, while the polarization of the 43 GHz radio core remains steady, perpendicular to the jet direction. Optical spectropolarimetry of the object in the quiescent state suggests a trend of increasing degree of polarization with increasing wavelength, providing additional evidence for an unpolarized emission component, possibly thermal emission from the accretion disk, contributing toward the blue end of the optical spectrum. Over an extended period of several months, PKS 0528+134 shows moderate (amplitude constructed four spectral energy distributions (SEDs) corresponding to the times of the XMM-Newton observations. We find that even in the

  6. Deriving brown carbon from multiwavelength absorption measurements: method and application to AERONET and Aethalometer observations

    Directory of Open Access Journals (Sweden)

    X. Wang

    2016-10-01

    Full Text Available The radiative impact of organic aerosols (OA is a large source of uncertainty in estimating the global direct radiative effect (DRE of aerosols. This radiative impact includes not only light scattering but also light absorption from a subclass of OA referred to as brown carbon (BrC. However, the absorption properties of BrC are poorly understood, leading to large uncertainties in modeling studies. To obtain observational constraints from measurements, a simple absorption Ångström exponent (AAE method is often used to separate the contribution of BrC absorption from that of black carbon (BC. However, this attribution method is based on assumptions regarding the spectral dependence of BC that are often violated in the ambient atmosphere. Here we develop a new AAE method which improves upon previous approaches by using the information from the wavelength-dependent measurements themselves and by allowing for an atmospherically relevant range of BC properties, rather than fixing these at a single assumed value. We note that constraints on BC optical properties and mixing state would help further improve this method. We apply this method to multiwavelength absorption aerosol optical depth (AAOD measurements at AERONET sites worldwide and surface aerosol absorption measurements at multiple ambient sites. We estimate that BrC globally contributes up to 40 % of the seasonally averaged absorption at 440 nm. We find that the mass absorption coefficient of OA (OA-MAC is positively correlated with the BC ∕ OA mass ratio. Based on the variability in BC properties and BC ∕ OA emission ratio, we estimate a range of 0.05–1.5 m2 g−1 for OA-MAC at 440 nm. Using the combination of AERONET and OMI UV absorption observations we estimate that the AAE388∕440 nm for BrC is generally  ∼ 4 worldwide, with a smaller value in Europe (< 2. Our analyses of observations at two surface sites (Cape Cod, to the southeast of Boston, and the

  7. PKS 1954-388: RadioAstron Detection on 80,000 km Baselines and Multiwavelength Observations

    Science.gov (United States)

    Edwards, P. G.; Kovalev, Y. Y.; Ojha, R.; An, H.; Bignall, H.; Carpenter, B.; Hovatta, T.; Stevens, J.; Voytsik, P.; Andrianov, A. S.; Dutka, M.; Hase, H.; Horiuchi, S.; Jauncey, D. L.; Kadler, M.; Lisakov, M.; Lovell, J. E. J.; McCallum, J.; Müller, C.; Phillips, C.; Plötz, C.; Quick, J.; Reynolds, C.; Schulz, R.; Sokolovsky, K. V.; Tzioumis, A. K.; Zuga, V.

    2017-04-01

    We present results from a multiwavelength study of the blazar PKS 1954-388 at radio, UV, X-ray, and gamma-ray energies. A RadioAstron observation at 1.66 GHz in June 2012 resulted in the detection of interferometric fringes on baselines of 6.2 Earth-diameters. This suggests a source frame brightness temperature of greater than 2 × 1012 K, well in excess of both equipartition and inverse Compton limits and implying the existence of Doppler boosting in the core. An 8.4-GHz TANAMI VLBI image, made less than a month after the RadioAstron observations, is consistent with a previously reported superluminal motion for a jet component. Flux density monitoring with the Australia Telescope Compact Array confirms previous evidence for long-term variability that increases with observing frequency. A search for more rapid variability revealed no evidence for significant day-scale flux density variation. The ATCA light-curve reveals a strong radio flare beginning in late 2013, which peaks higher, and earlier, at higher frequencies. Comparison with the Fermi gamma-ray light-curve indicates this followed 9 months after the start of a prolonged gamma-ray high-state-a radio lag comparable to that seen in other blazars. The multiwavelength data are combined to derive a Spectral Energy Distribution, which is fitted by a one-zone synchrotron-self-Compton (SSC) model with the addition of external Compton (EC) emission.

  8. Multiwavelength observations of the extreme X-ray-selected BL Lacertae object PG 1553+11 (1ES 1553+113)

    NARCIS (Netherlands)

    Osterman, M. Angela; Miller, H. Richard; Campbell, Amy M.; Marshall, Kevin; McFarland, John P.; Aller, Hugh; Aller, Margo; Fried, Robert E.; Kurtanidze, Omar M.; Nikolashvili, Maria G.; Tornikoski, Merja; Valtaoja, Esko

    PG 1553+11 was the target of a coordinated 3 week multiwavelength campaign during 2003 April and May. A significant X-ray flare was observed during the second half of this campaign. Although no optical flare was recorded during the X-ray campaign, optical observations obtained immediately prior to

  9. Multiwavelength polarization observations of the γ-ray bright quasar PKS 0420-014

    Directory of Open Access Journals (Sweden)

    Troitskiy I.S.

    2013-12-01

    Full Text Available We analyze total and polarized intensity images of the quasar PKS 0420-014 obtained monthly with the VLBA at 43 GHz during 2008–2012 along with γ-ray data provided by the Fermi Large Area Telescope and multi-color photometric and polarimetric measurements collected by different optical telescopes. During this period the quasar underwent a number of optical flares, which were accompanied by rapid rotation of polarization angle, an increase of activity in γ-rays, and the appearance of new superluminal knots in the parsec-scale jet. We investigate the fine structure of the flares at different wavelengths and in polarized light, and determine kinematic parameters of the knots. We compare the rapid evolution of the optical polarization with the polarization of the VLBI core and knots. We interpret the multi-wavelength behavior within a model that places the blazar “dissipation zone” at the millimeter-wave core of the parsec-scale jet.

  10. Forest Fire Smoke Layers Observed in the Free Troposphere over Portugal with a Multiwavelength Raman Lidar: Optical and Microphysical Properties

    Directory of Open Access Journals (Sweden)

    Sérgio Nepomuceno Pereira

    2014-01-01

    Full Text Available Vertically resolved optical and microphysical properties of biomass burning aerosols, measured in 2011 with a multiwavelength Raman lidar, are presented. The transportation time, within 1-2 days (or less, pointed towards the presence of relatively fresh smoke particles over the site. Some strong layers aloft were observed with particle backscatter and extinction coefficients (at 355 nm greater than 5 Mm−1 sr−1 and close to 300 Mm−1, respectively. The particle intensive optical properties showed features different from the ones reported for aged smoke, but rather consistent with fresh smoke. The Ångström exponents were generally high, mainly above 1.4, indicating a dominating accumulation mode. Weak depolarization values, as shown by the small depolarization ratio of 5% or lower, were measured. Furthermore, the lidar ratio presented no clear wavelength dependency. The inversion of the lidar signals provided a set of microphysical properties including particle effective radius below 0.2 μm, which is less than values previously observed for aged smoke particles. Real and imaginary parts of refractive index of about 1.5-1.6 and 0.02i, respectively, were derived. The single scattering albedo was in the range between 0.85 and 0.93; these last two quantities indicate the nonnegligible absorbing characteristics of the observed particles.

  11. MULTI-WAVELENGTH OBSERVATIONS OF BLAZAR AO 0235+164 IN THE 2008-2009 FLARING STATE

    Energy Technology Data Exchange (ETDEWEB)

    Ackermann, M. [Deutsches Elektronen Synchrotron DESY, D-15738 Zeuthen (Germany); Ajello, M.; Blandford, R. D.; Bloom, E. D.; Borgland, A. W.; Bottacini, E.; Buehler, R.; Cameron, R. A. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Ballet, J.; Casandjian, J. M. [Laboratoire AIM, CEA-IRFU/CNRS/Universite Paris Diderot, Service d' Astrophysique, CEA Saclay, 91191 Gif sur Yvette (France); Barbiellini, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy); Bastieri, D.; Buson, S. [Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padova (Italy); Bellazzini, R.; Bregeon, J. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Bonamente, E. [Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, I-06123 Perugia (Italy); Brigida, M. [Dipartimento di Fisica ' M. Merlin' dell' Universita e del Politecnico di Bari, I-70126 Bari (Italy); Bruel, P. [Laboratoire Leprince-Ringuet, Ecole polytechnique, CNRS/IN2P3, Palaiseau (France); Caliandro, G. A. [Institut de Ciencies de l' Espai (IEEE-CSIC), Campus UAB, 08193 Barcelona (Spain); Caraveo, P. A., E-mail: eduardo@slac.stanford.edu, E-mail: madejski@slac.stanford.edu, E-mail: fabio.gargano@ba.infn.it, E-mail: silvia.raino@ba.infn.it, E-mail: lreyes04@calpoly.edu, E-mail: knalew@colorado.edu, E-mail: sikora@camk.edu.pl [INAF-Istituto di Astrofisica Spaziale e Fisica Cosmica, I-20133 Milano (Italy); Collaboration: Fermi-LAT Collaboration; GASP-WEBT consortium; F-GAMMA; Iram-PdBI; Kanata; RXTE; SMARTS; Swift-XRT; and others

    2012-06-01

    The blazar AO 0235+164 (z = 0.94) has been one of the most active objects observed by Fermi Large Area Telescope (LAT) since its launch in Summer 2008. In addition to the continuous coverage by Fermi, contemporaneous observations were carried out from the radio to {gamma}-ray bands between 2008 September and 2009 February. In this paper, we summarize the rich multi-wavelength data collected during the campaign (including F-GAMMA, GASP-WEBT, Kanata, OVRO, RXTE, SMARTS, Swift, and other instruments), examine the cross-correlation between the light curves measured in the different energy bands, and interpret the resulting spectral energy distributions in the context of well-known blazar emission models. We find that the {gamma}-ray activity is well correlated with a series of near-IR/optical flares, accompanied by an increase in the optical polarization degree. On the other hand, the X-ray light curve shows a distinct 20 day high state of unusually soft spectrum, which does not match the extrapolation of the optical/UV synchrotron spectrum. We tentatively interpret this feature as the bulk Compton emission by cold electrons contained in the jet, which requires an accretion disk corona with an effective covering factor of 19% at a distance of 100 R{sub g}. We model the broadband spectra with a leptonic model with external radiation dominated by the infrared emission from the dusty torus.

  12. MULTIWAVELENGTH OBSERVATIONS OF A SLOW-RISE, MULTISTEP X1.6 FLARE AND THE ASSOCIATED ERUPTION

    Energy Technology Data Exchange (ETDEWEB)

    Yurchyshyn, V. [Big Bear Solar Observatory, New Jersey Institute of Technology, Big Bear City, CA 92314 (United States); Kumar, P.; Cho, K.-S.; Lim, E.-K. [Korea Astronomy and Space Science Institute, 776 Daedeok-daero, Yuseong-gu, Daejeon, 305-348 (Korea, Republic of); Abramenko, V. I. [Central Astronomical Observatory of the Russian Academy of Sciences at Pulkovo, 196140, Pulkovskoye chaussee 65, Saint-Petersburg (Russian Federation)

    2015-10-20

    Using multiwavelength observations, we studied a slow-rise, multistep X1.6 flare that began on 2014 November 7 as a localized eruption of core fields inside a δ-sunspot and later engulfed the entire active region (AR). This flare event was associated with formation of two systems of post-eruption arcades (PEAs) and several J-shaped flare ribbons showing extremely fine details, irreversible changes in the photospheric magnetic fields, and it was accompanied by a fast and wide coronal mass ejection. Data from the Solar Dynamics Observatory and IRIS spacecraft, along with the ground-based data from the New Solar Telescope, present evidence that (i) the flare and the eruption were directly triggered by a flux emergence that occurred inside a δ-sunspot at the boundary between two umbrae; (ii) this event represented an example of the formation of an unstable flux rope observed only in hot AIA channels (131 and 94 Å) and LASCO C2 coronagraph images; (iii) the global PEA spanned the entire AR and was due to global-scale reconnection occurring at heights of about one solar radius, indicating the global spatial and temporal scale of the eruption.

  13. Multi-wavelength Observations of Blazar AO 0235+164 in the 2008-2009 Flaring State

    Science.gov (United States)

    Ackermann, M.; Ajello, M.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bottacini, E.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Casandjian, J. M.; Cavazzuti, E.; Cecchi, C.; Charles, E.; Chekhtman, A.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Cutini, S.; D'Ammando, F.; de Palma, F.; Dermer, C. D.; Silva, E. do Couto e.; Drell, P. S.; Drlica-Wagner, A.; Dubois, R.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Focke, W. B.; Fortin, P.; Fuhrmann, L.; Fukazawa, Y.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Germani, S.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Guiriec, S.; Hadasch, D.; Hayashida, M.; Hughes, R. E.; Itoh, R.; Jóhannesson, G.; Johnson, A. S.; Katagiri, H.; Kataoka, J.; Knödlseder, J.; Kuss, M.; Lande, J.; Larsson, S.; Lee, S.-H.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Mazziotta, M. N.; McEnery, J. E.; Mehault, J.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Naumann-Godo, M.; Nishino, S.; Norris, J. P.; Nuss, E.; Ohsugi, T.; Okumura, A.; Omodei, N.; Orlando, E.; Ozaki, M.; Paneque, D.; Panetta, J. H.; Pelassa, V.; Pesce-Rollins, M.; Pierbattista, M.; Piron, F.; Pivato, G.; Porter, T. A.; Rainò, S.; Rando, R.; Rastawicki, D.; Razzano, M.; Readhead, A.; Reimer, A.; Reimer, O.; Reyes, L. C.; Richards, J. L.; Sbarra, C.; Sgrò, C.; Siskind, E. J.; Spandre, G.; Spinelli, P.; Szostek, A.; Takahashi, H.; Tanaka, T.; Thayer, J. G.; Thayer, J. B.; Thompson, D. J.; Tinivella, M.; Torres, D. F.; Tosti, G.; Troja, E.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Vianello, G.; Vitale, V.; Waite, A. P.; Winer, B. L.; Wood, K. S.; Yang, Z.; Zimmer, S.; Fermi-LAT Collaboration; Moderski, R.; Nalewajko, K.; Sikora, M.; Villata, M.; Raiteri, C. M.; Aller, H. D.; Aller, M. F.; Arkharov, A. A.; Benítez, E.; Berdyugin, A.; Blinov, D. A.; Boettcher, M.; Bravo Calle, O. J. A.; Buemi, C. S.; Carosati, D.; Chen, W. P.; Diltz, C.; Di Paola, A.; Dolci, M.; Efimova, N. V.; Forné, E.; Gurwell, M. A.; Heidt, J.; Hiriart, D.; Jordan, B.; Kimeridze, G.; Konstantinova, T. S.; Kopatskaya, E. N.; Koptelova, E.; Kurtanidze, O. M.; Lähteenmäki, A.; Larionova, E. G.; Larionova, L. V.; Larionov, V. M.; Leto, P.; Lindfors, E.; Lin, H. C.; Morozova, D. A.; Nikolashvili, M. G.; Nilsson, K.; Oksman, M.; Roustazadeh, P.; Sievers, A.; Sigua, L. A.; Sillanpää, A.; Takahashi, T.; Takalo, L. O.; Tornikoski, M.; Trigilio, C.; Troitsky, I. S.; Umana, G.; GASP-WEBT Consortium; Angelakis, E.; Krichbaum, T. P.; Nestoras, I.; Riquelme, D.; F-GAMMA; Krips, M.; Trippe, S.; Iram-PdBI; Arai, A.; Kawabata, K. S.; Sakimoto, K.; Sasada, M.; Sato, S.; Uemura, M.; Yamanaka, M.; Yoshida, M.; Kanata; Belloni, T.; Tagliaferri, G.; RXTE; Bonning, E. W.; Isler, J.; Urry, C. M.; SMARTS; Hoversten, E.; Falcone, A.; Pagani, C.; Stroh, M.; (Swift-XRT

    2012-06-01

    The blazar AO 0235+164 (z = 0.94) has been one of the most active objects observed by Fermi Large Area Telescope (LAT) since its launch in Summer 2008. In addition to the continuous coverage by Fermi, contemporaneous observations were carried out from the radio to γ-ray bands between 2008 September and 2009 February. In this paper, we summarize the rich multi-wavelength data collected during the campaign (including F-GAMMA, GASP-WEBT, Kanata, OVRO, RXTE, SMARTS, Swift, and other instruments), examine the cross-correlation between the light curves measured in the different energy bands, and interpret the resulting spectral energy distributions in the context of well-known blazar emission models. We find that the γ-ray activity is well correlated with a series of near-IR/optical flares, accompanied by an increase in the optical polarization degree. On the other hand, the X-ray light curve shows a distinct 20 day high state of unusually soft spectrum, which does not match the extrapolation of the optical/UV synchrotron spectrum. We tentatively interpret this feature as the bulk Compton emission by cold electrons contained in the jet, which requires an accretion disk corona with an effective covering factor of 19% at a distance of 100 R g. We model the broadband spectra with a leptonic model with external radiation dominated by the infrared emission from the dusty torus.

  14. Multi-Wavelength Spectroscopic Observations of a White Light Flare Produced Directly by Non-thermal Electrons

    Science.gov (United States)

    Lee, Kyoung-Sun; Imada, Shinsuke; Watanabe, Kyoko; Bamba, Yumi; Brooks, David

    2017-08-01

    An X1.6 flare on 2014 October 22 was observed by multiple spectrometers in UV, EUV and X-ray (Hinode/EIS, IRIS, and RHESSI), and multi-wavelength imaging observations (SDO/AIA and HMI). We analyze a bright kernel that produces a white light (WL) flare with continuum enhancement and a hard X-ray (HXR) peak. Taking advantage of the spectroscopic observations of IRIS and Hinode/EIS, we measure the temporal variation of the plasma properties in the bright kernel in the chromosphere and corona. We find that explosive evaporation was observed when the WL emission occurred. The temporal correlation of the WL emission, HXR peak, and evaporation flows indicates that the WL emission was produced by accelerated electrons. We calculated the energy flux deposited by non-thermal electrons (observed by RHESSI) and compared it to the dissipated energy estimated from a chromospheric line (Mg II triplet) observed by IRIS. The deposited energy flux from the non-thermal electrons is about (3-7.7)x1010 erg cm-2 s-1 for a given low-energy cutoff of 30-40 keV, assuming the thick-target model. The energy flux estimated from the changes in temperature in the chromosphere measured using the Mg II subordinate line is about (4.6-6.7)×109 erg cm-2 s-1: ˜6%-22% of the deposited energy. This comparison of estimated energy fluxes implies that the continuum enhancement was directly produced by the non-thermal electrons.

  15. Multi-wavelength Observations of the Black Widow Pulsar 2FGL J2339.6-0532 with OISTER and Suzaku

    Science.gov (United States)

    Yatsu, Yoichi; Kataoka, Jun; Takahashi, Yosuke; Tachibana, Yutaro; Kawai, Nobuyuki; Shibata, Shimpei; Pike, Sean; Yoshii, Taketoshi; Arimoto, Makoto; Saito, Yoshihiko; Nakamori, Takeshi; Sekiguchi, Kazuhiro; Kuroda, Daisuke; Yanagisawa, Kenshi; Hanayama, Hidekazu; Watanabe, Makoto; Hamamoto, Ko; Nakao, Hikaru; Ozaki, Akihito; Motohara, Kentaro; Konishi, Masahiro; Tateuchi, Ken; Matsunaga, Noriyuki; Morokuma, Tomoki; Nagayama, Takahiro; Murata, Katsuhiro; Akitaya, Hiroshi; Yoshida, Michitoshi; Ali, Gamal B.; Essam Mohamed, A.; Isogai, Mizuki; Arai, Akira; Takahashi, Hidenori; Hashimoto, Osamu; Miyanoshita, Ryo; Omodaka, Toshihiro; Takahashi, Jun; Tokimasa, Noritaka; Matsuda, Kentaro; Okumura, Shin-ichiro; Nishiyama, Kota; Urakawa, Seitaro; Nogami, Daisaku; Oasa, Yumiko; OISTER Team

    2015-04-01

    Multi-wavelength observations of the black widow binary system 2FGL J2339.6-0532 are reported. The Fermi gamma-ray source 2FGL J2339.6-0532 was recently categorized as a black widow in which a recycled millisecond pulsar (MSP) is evaporating the companion star with its powerful pulsar wind. Our optical observations show clear sinusoidal light curves due to the asymmetric temperature distribution of the companion star. Assuming a simple geometry, we constrained the range of the inclination angle of the binary system to 52{}^\\circ \\lt i\\lt 59{}^\\circ , which enables us to discuss the interaction between the pulsar wind and the companion in detail. The X-ray spectrum consists of two components: a soft, steady component that seems to originate from the surface of the MSP, and a hard, variable component from the wind-termination shock near the companion star. The measured X-ray luminosity is comparable to the bolometric luminosity of the companion, meaning that the heating efficiency is less than 0.5. In the companion orbit, 1011 cm from the pulsar, the pulsar wind is already in the particle-dominant stage with a magnetization parameter of σ \\lt 0.1. In addition, we precisely investigated the time variations of the X-ray periodograms and detected a weakening of the orbital modulation. The observed phenomenon may be related to unstable pulsar wind activity or weak mass accretion, both of which can result in the temporal extinction of the radio pulse.

  16. Multi-wavelength observations of the enduring type IIn Supernovae 2005ip and 2006jd

    DEFF Research Database (Denmark)

    Stritzinger, Maximilian; Taddia, Francesco; Fransson, Claes

    2012-01-01

    extend from UV to mid-infrared wavelengths, and like SN 2005ip, are compared to reported X-ray measurements to understand the nature of the progenitor. Both objects display a number of similarities with the 1988Z-like subclass of SN IIn including (1) remarkably similar early-and late-phase optical......We present an observational study of the Type IIn supernovae (SNe IIn) 2005ip and 2006jd. Broadband UV, optical, and near-IR photometry, and visual-wavelength spectroscopy of SN 2005ip complement and extend upon published observations to 6.5 years past discovery. Our observations of SN 2006jd...

  17. Characterizing Giant Exoplanets through Multiwavelength Transit Observations: HAT-P-8b

    Science.gov (United States)

    Jarka, Kyla L.; Cole, Jackson Lane; Gardner, Cristilyn N.; Garver, Bethany Ray; Kar, Aman; McGough, Aylin Marie; PeQueen, David Jeffrey; Rivera, Daniel Ivan; Kasper, David; Jang-Condell, Hannah; Kobulnicky, Henry; Dale, Daniel

    2018-01-01

    Discovering and characterizing gas giants is important to the search for other life, as gas giants greatly affect the habitability of a solar system. Transits of exoplanets observed in visual photometric bands have been used to characterize their atmospheres and confirm planet parameters. We observed two primary transits of the hot gas giant HAT-P-8b with the Wyoming Infrared Observatory’s 2.3-meter telescope. Using multi-filter photometry in the g, r, i, and z bands (Sloan filters) we were able to update HAT-P-8b’s planet parameters and constrain characteristics of its atmosphere. Preliminary findings show that there is wavelength dependence in the depth of the transit observations. An infrared spectroscopic follow up of this candidate could yield more details on its atmospheric composition.

  18. ERRATIC FLARING OF BL LAC IN 2012–2013: MULTIWAVELENGTH OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Wehrle, Ann E. [Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301 (United States); Grupe, Dirk [Space Science Center, Morehead State University, 235 Martindale Drive, Morehead, KY 40351 (United States); Jorstad, Svetlana G.; Marscher, Alan P. [Institute for Astrophysical Research, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States); Gurwell, Mark [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA-02138 (United States); Baloković, Mislav; Hovatta, Talvikki; Harrison, Fiona H. [Cahill Center for Astronomy and Astrophysics, Caltech, Pasadena, CA 91125 (United States); Madejski, Grzegorz M. [Kavli Institute for Particle Astrophysics and Cosmology, SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States); Stern, Daniel, E-mail: awehrle@spacescience.org [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

    2016-01-10

    BL Lac, the eponymous blazar, flared to historically high levels at millimeter, infrared, X-ray, and gamma-ray wavelengths in 2012. We present observations made with Herschel, Swift, NuSTAR, Fermi, the Submillimeter Array, CARMA, and the VLBA in 2012–2013, including three months with nearly daily sampling at several wavebands. We have also conducted an intensive campaign of 30 hr with every-orbit observations by Swift and NuSTAR, accompanied by Herschel, and Fermi observations. The source was highly variable at all bands. Time lags, correlations between bands, and the changing shapes of the spectral energy distributions can be explained by synchrotron radiation and inverse Compton emission from nonthermal seed photons originating from within the jet. The passage of four new superluminal very long baseline interferometry knots through the core and two stationary knots about 4 pc downstream accompanied the high flaring in 2012–2013. The seed photons for inverse Compton scattering may arise from the stationary knots and from a Mach disk near the core where relatively slow-moving plasma generates intense nonthermal radiation. The 95 spectral energy distributions obtained on consecutive days form the most densely sampled, broad wavelength coverage for any blazar. The observed spectral energy distributions and multi-waveband light curves are similar to simulated spectral energy distributions and light curves generated with a model in which turbulent plasma crosses a conical shock with a Mach disk.

  19. Aerosol retrievals from multi-angle, multi-wavelength, photo-polarimetric observations near clouds

    NARCIS (Netherlands)

    Stap, F.A.

    2016-01-01

    Aerosol plays a complex but important role in the Earth's climate. Better global coverage of aerosol observations and more information on the aerosol microphysical parameters are needed to improve our understanding of the climate. This book contains 3 studies of improving the global coverage of

  20. Testing Planetary Volcanism Models with Multi-Wavelength Near Infrared Observations of Kilauea Flows and Fountains

    Science.gov (United States)

    Howell, Robert R.; Radebaugh, Jani; M. C Lopes, Rosaly; Kerber, Laura; Solomonidou, Anezina; Watkins, Bryn

    2017-10-01

    Using remote sensing of planetary volcanism on objects such as Io to determine eruption conditions is challenging because the emitting region is typically not resolved and because exposed lava cools so quickly. A model of the cooling rate and eruption mechanism is typically used to predict the amount of surface area at different temperatures, then that areal distribution is convolved with a Planck blackbody emission curve, and the predicted spectra is compared with observation. Often the broad nature of the Planck curve makes interpretation non-unique. However different eruption mechanisms (for example cooling fire fountain droplets vs. cooling flows) have very different area vs. temperature distributions which can often be characterized by simple power laws. Furthermore different composition magmas have significantly different upper limit cutoff temperatures. In order to test these models in August 2016 and May 2017 we obtained spatially resolved observations of spreading Kilauea pahoehoe flows and fire fountains using a three-wavelength near-infrared prototype camera system. We have measured the area vs. temperature distribution for the flows and find that over a relatively broad temperature range the distribution does follow a power law matching the theoretical predictions. As one approaches the solidus temperature the observed area drops below the simple model predictions by an amount that seems to vary inversely with the vigor of the spreading rate. At these highest temperatures the simple models are probably inadequate. It appears necessary to model the visco-elastic stretching of the very thin crust which covers even the most recently formed surfaces. That deviation between observations and the simple models may be particularly important when using such remote sensing observations to determine magma eruption temperatures.

  1. Multi-wavelength imaging observations of plasma depletions over Kavalur, India

    Directory of Open Access Journals (Sweden)

    H. S. S. Sinha

    2001-09-01

    Full Text Available Observations of ionospheric plasma depletions were made over Kavalur (12.56° N, 78.8° E, Mag. Lat 4.6° N, India during March–pril 1998 using an all sky optical imaging system operating at 630 nm, 777.4 nm and 557.7 nm. Out of 14 nights of observations, plasma depletions were seen only on 9 nights. Except for 21 March 1998, which was a magnetically disturbed period, all other nights belonged to a magnetically quiet period. Some of the important results obtained from these observations are: (a After the onset of the equatorial spread F (ESF, plasma depletions take typically about 2 hrs 40 min to come to a fully developed state, (b There are three distinct types of plasma depletions: type 1 have an east-west (e–w extent of 250–350 km with an inter-depletion distance (IDD of 125–300 km; Type 2 have an e–w extent of 100–150 km and IDD of 50–150 km; Type 3 have smallest the e–w extent (40–100 km and IDD of 20–60 km, (c Most of the observed plasma depletions (> 82% had their eastward velocity in the range of 25–125 ms–1. Almost stationary plasma depletions (0–25 ms–1 were observed on one night, which was magnetically disturbed. These very slow moving depletions appear to be the result of a modification of the F-region dynamo field due to direct penetration of the electric field and/or changes in the neutral winds induced by the magnetic disturbance, (d On the night of 21/22 March 1998, which was a magnetically disturbed period, plasma depletions could be seen simultaneously in all three observing wavelengths, i.e. in 630 nm, 777.4 nm and 557.7 nm. It is believed that this simultaneous occurrence was due to neutral density modifications as a result of enhanced magnetic activity. (e Well developed brightness patterns were observed for the first time in 777.4 nm images. Earlier, such brightness patterns were observed only in 630 nm and 557.7 nm images. These brightness patterns initially appear as very small regions in the

  2. Characterizing Giant Exoplanets through Multiwavelength Transit Observations: HAT-P-5 b

    Science.gov (United States)

    PeQueen, David Jeffrey; Cole, Jackson Lane; Gardner, Cristilyn N.; Garver, Bethany Ray; Jarka, Kyla L.; Kar, Aman; McGough, Aylin M.; Rivera, Daniel Ivan; Kasper, David; Jang-Condell, Hannah; Kobulnicky, Henry; Dale, Daniel

    2018-01-01

    During the summer of 2017, we observed hot Jupiter-type exoplanet transit events using the Wyoming Infrared Observatory’s 2.3 meter telescope. We observed 14 unique exoplanets during transit events; one such target was HAT-P-5 b. In total, we collected 53 usable science images in the Sloan filter set, particularly with the g’, r’, z’, and i’ band wavelength filters. This exoplanet transited approximately 40 minutes earlier than the currently published literature suggests. After reducing the data and running a Markov chain Monte Carlo analysis, we present results describing the planetary radius, semi-major axis, orbital period, and inclination of HAT-P-5 b. Characteristics of Rayleigh scattering are present in the atmosphere of this exoplanet. This work is supported by the National Science Foundation under REU grant AST 1560461.

  3. Ground-based multiwavelength observations of comet 103P/Hartley 2

    Energy Technology Data Exchange (ETDEWEB)

    Gicquel, A.; Villanueva, G. L.; Cordiner, M. A. [Catholic University of America, Physics Department, 620 Michigan Avenue NE, Washington, DC (United States); Milam, S. N.; Charnley, S. B. [Goddard Center for Astrobiology, NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771 (United States); Remijan, A. J. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Coulson, I. M. [Joint Astronomy Centre, 660 North A' ohoku Place University Park, Hilo, HI 96720 (United States); Chuang, Y.-L.; Kuan, Y.-J., E-mail: adeline.gicquel@nasa.gov, E-mail: stefanie.n.milam@nasa.gov, E-mail: geronimo.l.villanueva@nasa.gov, E-mail: steven.b.charnley@nasa.gov, E-mail: martin.a.cordiner@nasa.gov, E-mail: aremijan@nrao.edu, E-mail: i.coulson@jach.hawaii.edu, E-mail: ylchuang@std.ntnu.edu.tz, E-mail: kuan@ntnu.edu.tw [National Taiwan Normal University, 88 Sec. 4 Ting-Chou Road, Taipei 116, Taiwan (China)

    2014-10-10

    The Jupiter-family comet 103P/Hartley 2 (103P) was the target of the NASA EPOXI mission. In support of this mission, we conducted observations from radio to submillimeter wavelengths of comet 103P in the three weeks preceding the spacecraft rendezvous on UT 2010 November 4.58. This time period included the passage at perihelion and the closest approach of the comet to the Earth. Here, we report detections of HCN, H{sub 2}CO, CS, and OH and upper limits for HNC and DCN toward 103P using the Arizona Radio Observatory Kitt Peak 12 m telescope (ARO 12 m) and submillimeter telescope (SMT), the James Clerk Maxwell Telescope (JCMT), and the Green Bank Telescope (GBT). The water production rate, Q{sub H{sub 2O}} = (0.67-1.07) × 10{sup 28} s{sup –1}, was determined from the GBT OH data. From the average abundance ratios of HCN and H{sub 2}CO relative to water (0.13 ± 0.03% and 0.14 ± 0.03%, respectively), we conclude that H{sub 2}CO is depleted and HCN is normal with respect to typically observed cometary mixing ratios. However, the abundance ratio of HCN with water shows a large diversity with time. Using the JCMT data, we measured an upper limit for the DCN/HCN ratio <0.01. Consecutive observations of ortho-H{sub 2}CO and para-H{sub 2}CO on November 2 (from data obtained at the JCMT) allowed us to derive an ortho:para ratio (OPR) of ≈2.12 ± 0.59 (1σ), corresponding to T {sub spin} > 8 K (2σ).

  4. Multiwavelength observations of a flux rope formation by series of magnetic reconnection in the chromosphere

    Science.gov (United States)

    Kumar, Pankaj; Yurchyshyn, Vasyl; Cho, Kyung-Suk; Wang, Haimin

    2017-07-01

    Using high-resolution observations from the 1.6 m New Solar Telescope (NST) operating at the Big Bear Solar Observatory (BBSO), we report direct evidence of merging and reconnection of cool Hα loops in the chromosphere during two homologous flares (B and C class) caused by a shear motion at the footpoints of two loops. The reconnection between these loops caused the formation of an unstable flux rope that showed counterclockwise rotation. The flux rope could not reach the height of torus instability and failed to form a coronal mass ejection. The HMI magnetograms revealed rotation of the negative and positive (N1/P2) polarity sunspots in the opposite directions, which increased the right- and left-handed twist in the magnetic structures rooted at N1/P2. Rapid photospheric flux cancellation (duration 20-30 min, rate ≈3.44 × 1020 Mx h-1) was observed during and even after the first B6.0 flare and continued until the end of the second C2.3 flare. The RHESSI X-ray sources were located at the site of the loop coalescence. To the best of our knowledge, such a clear interaction of chromospheric loops along with rapid flux cancellation has not been reported before. These high-resolution observations suggest the formation of a small flux rope by a series of magnetic reconnections within chromospheric loops that are associated with very rapid flux cancellation. Movies attached to Figs. 2, 7, 8, and 10 are available at http://www.aanda.org

  5. Suzaku And Multi-Wavelength Observations of OJ 287 During the Periodic Optical Outburst in 2007

    Energy Technology Data Exchange (ETDEWEB)

    Seta, Hiromi; /Saitama U.; Isobe, N.; /Kyoto U.; Tashiro, Makoto S.; /Saitama U.; Yaji, Yuichi; /Saitama U.; Arai, Akira; /Hiroshima U.; Fukuhara, Masayuki; /Tokyo U. /Grad. U. for Adv. Stud., Nagano; Kohno, Kotaro; /Tokyo U.; Nakanishi, Koichiro; /Grad. U. for Adv. Stud., Nagano; Sasada, Mahito; /Hiroshima U.; Shimajiri, Yoshito; /Tokyo U. /Grad. U. for Adv. Stud., Nagano; Tosaki, Tomoka; /Grad. U. for Adv. Stud., Nagano; Uemura, Makoto; /Hiroshima U.; Anderhub, Hans; /Zurich, ETH; Antonelli, L.A.; /INFN, Rome; Antoranz, Pedro; /Madrid U.; Backes, Michael; /Dortmund U.; Baixeras, Carmen; /Barcelona, Autonoma U.; Balestra, Silvia; /Madrid U.; Barrio, Juan Abel; /Madrid U.; Bastieri, Denis; /Padua U. /INFN, Padua; Becerra Gonzalez, Josefa; /IAC, La Laguna /Dortmund U. /Lodz U. /Lodz U. /DESY /Zurich, ETH /Munich, Max Planck Inst. /Padua U. /INFN, Padua /Siena U. /INFN, Siena /Barcelona, IEEC /Munich, Max Planck Inst. /Barcelona, IEEC /Madrid U. /Zurich, ETH /Wurzburg U. /Zurich, ETH /Madrid U. /Munich, Max Planck Inst. /Zurich, ETH /Madrid U. /Barcelona, IFAE /IAC, La Laguna /Laguna U., Tenerife /INFN, Rome /Dortmund U. /Udine U. /INFN, Udine /INFN, Padua /Udine U. /INFN, Udine /Barcelona, IEEC /Madrid U. /Udine U. /INFN, Udine /Udine U. /INFN, Udine /Udine U. /INFN, Udine /IAC, La Laguna /Madrid, CIEMAT /Sierra Nevada Observ. /Zurich, ETH /Padua U. /INFN, Padua /Wurzburg U. /Barcelona, IFAE /UC, Davis /Barcelona, IFAE /Barcelona, IFAE /Madrid U. /Barcelona, Autonoma U. /Munich, Max Planck Inst. /IAC, La Laguna /Laguna U., Tenerife /Barcelona, IFAE /IAC, La Laguna /Munich, Max Planck Inst. /Barcelona, Autonoma U. /Munich, Max Planck Inst. /SLAC /IAC, La Laguna /Laguna U., Tenerife /Zurich, ETH /Wurzburg U. /Munich, Max Planck Inst. /Munich, Max Planck Inst. /Munich, Max Planck Inst. /Zurich, ETH /INFN, Rome /UC, Davis /Siena U. /INFN, Siena /Turku U. /Padua U. /INFN, Padua /Udine U. /INFN, Udine /Padua U. /INFN, Padua /Zurich, ETH /Munich, Max Planck Inst. /DESY /Sofiya, Inst. Nucl. Res. /Udine U. /INFN, Udine /Wurzburg U. /INFN, Rome /Padua U. /INFN, Padua /Barcelona, IFAE /Barcelona, IFAE /Siena U. /INFN, Siena /Wurzburg U. /Madrid U. /Munich, Max Planck Inst. /Munich, Max Planck Inst. /Barcelona, IEEC /Sierra Nevada Observ. /Barcelona, IFAE /Madrid U. /Turku U. /Munich, Max Planck Inst. /Munich, Max Planck Inst. /UC, Santa Cruz /Madrid U. /Siena U. /INFN, Siena /Barcelona, IEEC /Turku U. /Padua U. /INFN, Padua /Zurich, ETH /Siena U. /INFN, Siena /Sierra Nevada Observ. /Udine U. /INFN, Udine /INFN, Trieste /Padua U. /INFN, Padua /Sierra Nevada Observ. /Padua U. /INFN, Padua /Barcelona, IFAE /Barcelona, IFAE /Dortmund U. /Barcelona, IEEC /ICREA, Barcelona /Barcelona, IFAE /Zurich, ETH /Barcelona, Autonoma U. /Wurzburg U. /Padua U. /INFN, Padua /Munich, Max Planck Inst. /INFN, Rome /Sierra Nevada Observ. /DESY /Padua U. /INFN, Padua /Udine U. /INFN, Udine /Munich, Max Planck Inst. /Munich, Max Planck Inst. /Pisa U. /INFN, Pisa /Barcelona, IFAE /Barcelona, IEEC /Turku U. /Munich, Max Planck Inst. /Lodz U. /Lodz U. /Wurzburg U. /Siena U. /INFN, Siena /Zurich, ETH /Turku U. /INFN, Rome /Sofiya, Inst. Nucl. Res. /Barcelona, IFAE /Munich, Max Planck Inst. /DESY /ICREA, Barcelona /Barcelona, IEEC /Siena U. /INFN, Siena /Sofiya, Inst. Nucl. Res. /Munich, Max Planck Inst. /Munich, Max Planck Inst. /Barcelona, IEEC /Sierra Nevada Observ. /Barcelona, IFAE /Barcelona, Autonoma U.

    2011-12-01

    Suzaku observations of the blazar OJ 287 were performed in 2007 April 10-13 and November 7-9. They correspond to a quiescent and a flaring state, respectively. The X-ray spectra of the source can be well described with single power-law models in both exposures. The derived X-ray photon index and the flux density at 1 keV were found to be {Lambda} = 1.65 {+-} 0.02 and S{sub 1keV} = 215 {+-} 5 nJy, in the quiescent state. In the flaring state, the source exhibited a harder X-ray spectrum ({Lambda} = 1.50 {+-} 0.01) with a nearly doubled X-ray flux density S{sub 1keV} = 404{sub -5}{sup +6} nJy. Moreover, significant hard X-ray signals were detected up to {approx} 27 keV. In cooperation with the Suzaku, simultaneous radio, optical, and very-high-energy {gamma}-ray observations of OJ 287 were performed with the Nobeyama Millimeter Array, the KANATA telescope, and the MAGIC telescope, respectively. The radio and optical fluxes in the flaring state (3.04 {+-} 0.46 Jy and 8.93 {+-} 0.05 mJy at 86.75 Hz and in the V-band, respectively) were found to be higher by a factor of 2-3 than those in the quiescent state (1.73 {+-} 0.26 Jy and 3.03 {+-} 0.01 mJy at 86.75 Hz and in the V-band, respectively). No notable {gamma}-ray events were detected in either observation. The spectral energy distribution of OJ 287 indicated that the X-ray spectrum was dominated by inverse Compton radiation in both observations, while synchrotron radiation exhibited a spectral cutoff around the optical frequency. Furthermore, no significant difference in the synchrotron cutoff frequency was found between the quiescent and flaring states. According to a simple synchrotron self-Compton model, the change of the spectral energy distribution is due to an increase in the energy density of electrons with small changes of both the magnetic field strength and the maximum Lorentz factor of electrons.

  6. A Wide Range Neutron Detector for Space Nuclear Reactor Applications

    Science.gov (United States)

    Nassif, Eduardo; Matatagui, Emilio; Sismonda, Miguel; Pretorius, Stephan

    2007-01-01

    We propose here a versatile and innovative solution for monitoring and controlling a space-based nuclear reactor that is based on technology already proved in ground based reactors. A Wide Range Neutron Detector (WRND) allows for a reduction in the complexity of space based nuclear instrumentation and control systems. A ground model, predecessor of the proposed system, has been installed and is operating at the OPAL (Open Pool Advanced Light Water Research Reactor) in Australia, providing long term functional data. A space compatible Engineering Qualification Model of the WRND has been developed, manufactured and verified satisfactorily by analysis, and is currently under environmental testing.

  7. Multiwavelength Observations of Strong Flares from the TeV Blazar 1ES 1959+650

    Science.gov (United States)

    Krawczynski, H.; Hughes, S. B.; Horan, D.; Aharonian, F.; Aller, M. F.; Aller, H.; Boltwood, P.; Buckley, J.; Coppi, P.; Fossati, G.; Götting, N.; Holder, J.; Horns, D.; Kurtanidze, O. M.; Marscher, A. P.; Nikolashvili, M.; Remillard, R. A.; Sadun, A.; Schröder, M.

    2004-01-01

    Following the detection of strong TeV γ-ray flares from the BL Lac object 1ES 1959+650 with the Whipple 10 m Cerenkov telescope on 2002 May 16 and 17, we performed intensive target of opportunity radio, optical, X-ray, and TeV γ-ray observations from 2002 May 18 to August 14. Observations with the X-ray telescope Rossi X-Ray Timing Explorer and the Whipple and HEGRA γ-ray telescopes revealed several strong flares, enabling us to sensitively test the X-ray-γ-ray flux correlation properties. Although the X-ray and γ-ray fluxes seemed to be correlated in general, we found an ``orphan'' γ-ray flare that was not accompanied by an X-ray flare. While we detected optical flux variability with the Boltwood and Abastumani observatories, the data did not give evidence for a correlation of the optical flux variability with the observed X-ray and γ-ray flares. Within statistical errors of about 0.03 Jy at 14.5 GHz and 0.05 Jy at 4.8 GHz, the radio fluxes measured with the University of Michigan Radio Astronomy Observatory stayed constant throughout the campaign; the mean values agreed well with the values measured on 2002 May 7 and June 7 at 4.9 and 15 GHz with the Very Large Array and at 4.8 GHz with archival flux measurements. After describing in detail the radio, optical, X-ray and γ-ray light curves, and spectral energy distributions (SEDs), we present initial modeling of the SED with a simple synchrotron self-Compton model. With the addition of another TeV blazar with good broadband data, we consider the set of all TeV blazars, to begin to look for a connection of the jet properties to the properties of the central accreting black hole thought to drive the jet. Remarkably, the temporal and spectral X-ray and γ-ray emission characteristics of TeV blazars are very similar, even though the mass estimates of their central black holes differ by up to 1 order of magnitude.

  8. X-Ray and Multi-Wavelength Observations of Gamma Ray Bursts (GRBs)

    Science.gov (United States)

    Kouveliotou, Chryssa

    2009-01-01

    The launch of the Italian (with Dutch participation) satellite BeppoSAX in 1996 enabled the detection of the first X-ray GRB afterglow, which in turn led to GRB counterpart detection in multiple wavelengths. This breakthrough firmly established the cosmological nature of GRBs. However, afterglow observations of GRBs took off in large numbers after the launch of NASA's Swift satellite in 2004. Swift enabled multiple major discoveries, such as the early lightcurves of X-ray afterglows, the first detection of a short GRB afterglow and opened more questions such as where are the elusive breaks in afterglow light curves. I will describe here these results and will discuss future opportunities and improvements in the field.

  9. Multiwavelength Observations of the Powerful Gamma-ray Quasar PKS 1510-089: Clues on the Jet Composition

    Energy Technology Data Exchange (ETDEWEB)

    Kataoka, J.; Madejski, G.; Sikora, M.; Roming, P.; Chester, M.M.; Grupe, D.; Tsubuku, Y.; Sato, R.; Kawai, N.; Tosti, G.; Impiombato, D.; Kovalev, Y.Y.; Kovalev, Y.A.; Edwards, Philip G.; Wagner, S.J.; Moderski, R.; Stawarz, L.; Takahashi, T.; Watanabe, S.

    2007-09-28

    We present the results from a multiwavelength campaign conducted in August 2006 of the powerful {gamma}-ray quasar PKS 1510--089 (z = 0.361). This campaign commenced with a deep Suzaku observation lasting three days for a total exposure time of 120 ks, and continued with Swift monitoring over 18 days. Besides Swift observations, which sampled the optical/UV flux in all 6 UVOT filters as well as the X-ray spectrum in the 0.3--10 keV energy range, the campaign included ground-based optical and radio data, and yielded a quasi-simultaneous broad-band spectral energy distribution from 109 Hz to 1019 Hz. Thanks to its low instrumental background, the Suzaku observation provided a high S/N X-ray spectrum, which is well represented by an extremely hard power-law with photon index {Gamma}{approx_equal}1.2, augmented by a soft component apparent below 1 keV, which is well described by a black-body model with temperature kT {approx_equal}0.2 keV. Monitoring by Suzaku revealed temporal variability which is different between the low and high energy bands, again suggesting the presence of a second, variable component in addition to the primary power-law emission. We model the broadband spectrum of PKS 1510--089 assuming that the high energy spectral component results from Comptonization of infrared radiation produced by hot dust located in the surrounding molecular torus. In the adopted internal shock scenario, the derived model parameters imply that the power of the jet is dominated by protons but with a number of electrons/positrons exceeding a number of protons by a factor {approx} 10. We also find that inhomogeneities responsible for the shock formation, prior to the collision may produce bulk-Compton radiation which can explain the observed soft X-ray excess and possible excess at {approx} 18 keV. We note, however, that the bulk-Compton interpretation is not unique, and the observed soft excess could arise as well via some other processes discussed briefly in the text.

  10. Multiwavelength Observations of 6 BL Lac Objects in 2008-2012

    Directory of Open Access Journals (Sweden)

    Morozova D.A.

    2013-12-01

    Full Text Available We present results of 4 years of VLBA monitoring along with γ-ray and optical R-band photometric observations of 6 BL Lac objects (3C 66A, S5 0716+71, PKS 0735+17, S4 0954+68, W Com, and OT 081. We have analyzed total intensity images obtained with the VLBA at 43 GHz and investigated the kinematic evolution of the parsec scale jets of the sources. For all sources we compare flux variations in the VLBI core and bright superluminal knots with γ-ray and optical light curves. The majority of γ-ray flares have optical counterparts. 67% of the γ-ray events are coincident with the appearance of new superluminal knots and/or flares in the millimeter-wave core. These results support the conclusion that for many flares in blazars the region of the γ-ray and optical emission is located in the vicinity or downstream of the mm-wave VLBI core.

  11. Cosmic ray acceleration parameters from multi-wavelength observations. The case of SN 1006

    Science.gov (United States)

    Berezhko, E. G.; Ksenofontov, L. T.; Völk, H. J.

    2009-10-01

    Aims: The properties of the Galactic supernova remnant (SNR) SN 1006 are theoretically reanalysed. Methods: Nonlinear kinetic theory is used to determine the acceleration efficiency of cosmic rays (CRs) in the supernova remnant SN 1006. The known range of astronomical parameters and the existing measurements of nonthermal emission are examined in order to define the values of the relevant physical parameters that determine the CR acceleration efficiency. Results: It is shown that the parameter values - proton injection rate, electron to proton ratio and downstream magnetic field strength -are determined with the appropriate accuracy. In particular the observed azimuthal variations in the γ-ray morphology also agree with the theoretical expectation. These parameter values, together with the reduction of the γ-ray flux relative to a spherically symmetric acceleration geometry, allow a good fit to the existing data, including the recently detected TeV emission by H.E.S.S. Conclusions: SN 1006 represents the first example where a high efficiency of nuclear CR production, required for the Galactic CR sources, is consistently established.

  12. MULTI-WAVELENGTH OBSERVATIONS OF 3FGL J2039.6–5618: A CANDIDATE REDBACK MILLISECOND PULSAR

    Energy Technology Data Exchange (ETDEWEB)

    Salvetti, D.; Mignani, R. P.; Luca, A. De; Belfiore, A.; Marelli, M.; Pizzocaro, D. [INAF—Istituto di Astrofisica Spaziale e Fisica Cosmica Milano, via E. Bassini 15, I-20133, Milano (Italy); Delvaux, C.; Greiner, J.; Becker, W. [Max-Planck Institut für Extraterrestrische Physik, Giessenbachstrasse 1, D-85741 Garching bei München (Germany); Pallanca, C. [Dipartimento di Fisica e Astronomia, Università degli Studi di Bologna, Viale Berti Pichat 6-2, I-40127, Bologna (Italy); Breeveld, A. A. [Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey, RH5 6NT (United Kingdom)

    2015-12-01

    We present multi-wavelength observations of the unassociated γ-ray source 3FGL J2039.6−5618 detected by the Fermi Large Area Telescope. The source γ-ray properties suggest that it is a pulsar, most likely a millisecond pulsar, for which neither radio nor γ-ray pulsations have been detected. We observed 3FGL J2039.6−5618 with XMM-Newton and discovered several candidate X-ray counterparts within/close to the γ-ray error box. The brightest of these X-ray sources is variable with a period of 0.2245 ± 0.0081 days. Its X-ray spectrum can be described by a power law with photon index Γ{sub X} = 1.36 ± 0.09, and hydrogen column density N{sub H} < 4 × 10{sup 20} cm{sup −2}, which gives an unabsorbed 0.3–10 keV X-ray flux of 1.02 × 10{sup −13} erg cm{sup −2} s{sup −1}. Observations with the Gamma-Ray Burst Optical/Near-Infrared Detector discovered an optical counterpart to this X-ray source, with a time-averaged magnitude g′ ∼ 19.5. The counterpart features a flux modulation with a period of 0.22748 ± 0.00043 days that coincides, within the errors, with that of the X-ray source, confirming the association based on the positional coincidence. We interpret the observed X-ray/optical periodicity as the orbital period of a close binary system where one of the two members is a neutron star. The light curve profile of the companion star, which has two asymmetric peaks, suggests that the optical emission comes from two regions with different temperatures on its tidally distorted surface. Based upon its X-ray and optical properties, we consider this source as the most likely X-ray counterpart to 3FGL J2039.6−5618, which we propose to be a new redback system.

  13. The merging cluster Abell 1758 revisited: multi-wavelength observations and numerical simulations

    Science.gov (United States)

    Durret, F.; Laganá, T. F.; Haider, M.

    2011-05-01

    Context. Cluster properties can be more distinctly studied in pairs of clusters, where we expect the effects of interactions to be strong. Aims: We here discuss the properties of the double cluster Abell 1758 at a redshift z ~ 0.279. These clusters show strong evidence for merging. Methods: We analyse the optical properties of the North and South cluster of Abell 1758 based on deep imaging obtained with the Canada-France-Hawaii Telescope (CFHT) archive Megaprime/Megacam camera in the g' and r' bands, covering a total region of about 1.05 × 1.16 deg2, or 16.1 × 17.6 Mpc2. Our X-ray analysis is based on archive XMM-Newton images. Numerical simulations were performed using an N-body algorithm to treat the dark-matter component, a semi-analytical galaxy-formation model for the evolution of the galaxies and a grid-based hydrodynamic code with a parts per million (PPM) scheme for the dynamics of the intra-cluster medium. We computed galaxy luminosity functions (GLFs) and 2D temperature and metallicity maps of the X-ray gas, which we then compared to the results of our numerical simulations. Results: The GLFs of Abell 1758 North are well fit by Schechter functions in the g' and r' bands, but with a small excess of bright galaxies, particularly in the r' band; their faint-end slopes are similar in both bands. In contrast, the GLFs of Abell 1758 South are not well fit by Schechter functions: excesses of bright galaxies are seen in both bands; the faint-end of the GLF is not very well defined in g'. The GLF computed from our numerical simulations assuming a halo mass-luminosity relation agrees with those derived from the observations. From the X-ray analysis, the most striking features are structures in the metal distribution. We found two elongated regions of high metallicity in Abell 1758 North with two peaks towards the centre. In contrast, Abell 1758 South shows a deficit of metals in its central regions. Comparing observational results to those derived from numerical

  14. Multiwavelength observations of Active Galactic Nuclei from the radio to the hard X-rays

    Science.gov (United States)

    Beuchert, Tobias

    2017-07-01

    Active Galaxies form a peculiar type of galaxies. Their cores, the so-called "Active Galactic Nuclei" (AGN), are the most persistent luminous objects in the universe. Accretion of several solar masses per year onto black holes of Millions to Billions of solar masses drive the immense energy output of these systems, which can exceed that of the entire galaxy. The compact energy source, however, only measures about one over a Billion times that of the entire galaxy. Subject of my thesis are observations of the two main channels of energy release of selected AGN systems, both of which are encompassed by profound and yet unanswered questions. These channels are on the one hand the pronounced X-ray emission of the hot and compact accreting environment in close vicinity of the black hole, and on the other hand the radio synchrotron emission of magnetically collimated jets that are fed by portions of the accreted matter. These jets also function as effective accelerators and drive the injected matter deep into the intergalactic medium. As the circumnuclear environment of AGN is too compact to be spatially resolved in the X-rays, I show how X-ray spectroscopy can be used to: (1) understand the effects of strong gravity to trace the geometry and physics of the X-ray source and (2) more consistently quantify matter that surrounds and dynamically absorbs our direct line of sight towards the X-ray source. Second, I unveil the valuable information contained in the polarized radio light being emitted from magnetized jet outflows. In contrast to the X-ray emitting region, I am able to spatially resolve the inner parts of the jet of a prominent galaxy with help of the Very Long Baseline Array, a large network of radio telescopes. The resulting polarization maps turn out to be exceptionally promising in answering fundamental questions related to jet physics.

  15. WEBT multiwavelength monitoring and XMM-Newton observations of BL Lacertae in 2007-2008. Unveiling different emission components

    Science.gov (United States)

    Raiteri, C. M.; Villata, M.; Capetti, A.; Aller, M. F.; Bach, U.; Calcidese, P.; Gurwell, M. A.; Larionov, V. M.; Ohlert, J.; Nilsson, K.; Strigachev, A.; Agudo, I.; Aller, H. D.; Bachev, R.; Benítez, E.; Berdyugin, A.; Böttcher, M.; Buemi, C. S.; Buttiglione, S.; Carosati, D.; Charlot, P.; Chen, W. P.; Dultzin, D.; Forné, E.; Fuhrmann, L.; Gómez, J. L.; Gupta, A. C.; Heidt, J.; Hiriart, D.; Hsiao, W.-S.; Jelínek, M.; Jorstad, S. G.; Kimeridze, G. N.; Konstantinova, T. S.; Kopatskaya, E. N.; Kostov, A.; Kurtanidze, O. M.; Lähteenmäki, A.; Lanteri, L.; Larionova, L. V.; Leto, P.; Latev, G.; Le Campion, J.-F.; Lee, C.-U.; Ligustri, R.; Lindfors, E.; Marscher, A. P.; Mihov, B.; Nikolashvili, M. G.; Nikolov, Y.; Ovcharov, E.; Principe, D.; Pursimo, T.; Ragozzine, B.; Robb, R. M.; Ros, J. A.; Sadun, A. C.; Sagar, R.; Semkov, E.; Sigua, L. A.; Smart, R. L.; Sorcia, M.; Takalo, L. O.; Tornikoski, M.; Trigilio, C.; Uckert, K.; Umana, G.; Valcheva, A.; Volvach, A.

    2009-11-01

    Context: BL Lacertae is the prototype of the blazar subclass named after it. Yet, it has occasionally shown a peculiar behaviour that has questioned a simple interpretation of its broad-band emission in terms of synchrotron plus synchrotron self-Compton (SSC) radiation. Aims: In the 2007-2008 observing season we carried out a new multiwavelength campaign of the Whole Earth Blazar Telescope (WEBT) on BL Lacertae, involving three pointings by the XMM-Newton satellite in July and December 2007, and January 2008, to study its emission properties, particularly in the optical-X-ray energy range. Methods: The source was monitored in the optical-to-radio bands by 37 telescopes. The brightness level was relatively low. Some episodes of very fast variability were detected in the optical bands. Flux changes had larger amplitude at the higher radio frequencies than at longer wavelengths. Results: The X-ray spectra acquired by the EPIC instrument onboard XMM-Newton are well fitted by a power law with photon index Γ ˜ 2 and photoelectric absorption exceeding the Galactic value. However, when taking into account the presence of a molecular cloud on the line of sight, the EPIC data are best fitted by a double power law, implying a concave X-ray spectrum. The spectral energy distributions (SEDs) built with simultaneous radio-to-X-ray data at the epochs of the XMM-Newton observations suggest that the peak of the synchrotron emission lies in the near-IR band, and show a prominent UV excess, besides a slight soft-X-ray excess. A comparison with the SEDs corresponding to previous observations with X-ray satellites shows that the X-ray spectrum is very variable, since it can change from extremely steep to extremely hard, and can be more or less curved in intermediate states. We ascribe the UV excess to thermal emission from the accretion disc, and the other broad-band spectral features to the presence of two synchrotron components, with their related SSC emission. We fit the thermal

  16. Cobalt catalyzed hydroesterification of a wide range of olefins

    Energy Technology Data Exchange (ETDEWEB)

    Van Rensburg, H.; Hanton, M.; Tooze, R.P.; Foster, D.F. [Sasol Technology UK, St Andrews (United Kingdom)

    2011-07-01

    Petrochemical raw materials are an essential raw material for the production of detergents with a substantial portion of synthetic fatty alcohols being produced via hydroformylation of oil or coal derived olefins. Carbonylation processes other than hydroformylation have to date not been commercially employed for the production of fatty esters or alcohols. In this document we highlight the opportunities of converting olefins to esters using cobalt catalyzed alkoxycarbonylation. This process is highly versatile and applicable to a wide range of olefins, linear or branched, alpha or internal in combination with virtually any chain length primary or secondary alcohol allowing the synthesis of a diverse array of compounds such as ester ethoxylated surfactants, methyl branched detergents, lubricants and alkyl propanoates. Furthermore, alkoxycarbonylation of a broad olefin/paraffin hydrocarbon range could be used to produce the corresponding broad cut detergent alcohols. (orig.)

  17. Wide-Range Probing of Dzyaloshinskii-Moriya Interaction

    Science.gov (United States)

    Kim, Duck-Ho; Yoo, Sang-Cheol; Kim, Dae-Yun; Min, Byoung-Chul; Choe, Sug-Bong

    2017-03-01

    The Dzyaloshinskii-Moriya interaction (DMI) in magnetic objects is of enormous interest, because it generates built-in chirality of magnetic domain walls (DWs) and topologically protected skyrmions, leading to efficient motion driven by spin-orbit torques. Because of its importance for both potential applications and fundamental research, many experimental efforts have been devoted to DMI investigation. However, current experimental probing techniques cover only limited ranges of the DMI strength and have specific sample requirements. Thus, there are no versatile methods to quantify DMI over a wide range of values. Here, we present such an experimental scheme, which is based on the angular dependence of asymmetric DW motion. This method can be used to determine values of DMI much larger than the maximum strength of the external magnetic field strength, which demonstrates that various DMI strengths can be quantified with a single measurement setup. This scheme may thus prove essential to DMI-related emerging fields in nanotechnology.

  18. The 2010 Very High Energy Gamma-Ray Flare and 10 Years of Multi-Wavelength Observations of M87

    Science.gov (United States)

    Abramowski, A.; Acero, F.; Aharonian, F.; Akhperjanian, A G.; Anton, G.; Balzer, A.; Barnacka, A.; Barres de Almeida, U.; Becherini, Y.; Becker, J.; hide

    2011-01-01

    The giant radio galaxy M87 with its proximity (16 Mpc), famous jet, and very massive black hole ((3-6) X 10(exp 9) Solar Mass) provides a unique opportunity to investigate the origin of very high energy (VHE; E>100 GeV) gamma-ray emission generated in relativistic outflows and the surroundings of super-massive black holes. M87 has been established as a VHE gamma -ray emitter since 2006. The VHE gamma -ray emission displays strong variability on timescales as short as a day. In this paper, results from a joint VHE monitoring campaign on M87 by the MAGIC and VERITAS instruments in 2010 are reported. During the campaign, a flare at VHE was detected. triggering further observations at VHE (H.E.S.S.), X-rays (Chandra), and radio (43 GHz VLBA). The excellent sampling of the VHE gamma-ray light curve enables one to derive a precise temporal characterization of the flare: the single, isolated flare is well described by a two-sided exponential function with significantly different flux rise and decay times of rise tau ((sup rise sub d) = (1:69 +/- 0:30) days and tau(sup decay sub d = (0:611 +/- 0:080) days, respectively. While the overall variability pattern of the 2010 flare appears somewhat different from that of previous VHE flares in 2005 and 2008, they share very similar timescales (approx day), peak fluxes (Phi (sub > 0:35 TeV) approx. equals (1 - 3) X 10(exp -11) ph / square cm/s), and VHE spectra. 43 GHz VLBA radio observations of the inner jet regions indicate no enhanced flux in 2010 in contrast to observations in 2008, where an increase of the radio flux of the innermost core regions coincided with a VHE flare. On the other hand, Chandra X-ray observations taken approx 3 days after the peak of the VHE gamma -ray emission reveal an enhanced flux from the core (flux increased by factor approx 2; variability timescale < 2 days). The long-term (2001-2010) multi-wavelength (MWL) light curve of M87, spanning from radio to VHE and including data from HST, LT, VLA and

  19. Multiwavelength Observations of 3C 454.3. III. Eighteen Months of Agile Monitoring of the "Crazy Diamond"

    Science.gov (United States)

    Vercellone, S.; D'Ammando, F.; Vittorini, V.; Donnarumma, I.; Pucella, G.; Tavani, M.; Ferrari, A.; Raiteri, C. M.; Villata, M.; Romano, P.; Krimm, H.; Tiengo, A.; Chen, A. W.; Giovannini, G.; Venturi, T.; Giroletti, M.; Kovalev, Y. Y.; Sokolovsky, K.; Pushkarev, A. B.; Lister, M. L.; Argan, A.; Barbiellini, G.; Bulgarelli, A.; Caraveo, P.; Cattaneo, P. W.; Cocco, V.; Costa, E.; Del Monte, E.; De Paris, G.; Di Cocco, G.; Evangelista, Y.; Feroci, M.; Fiorini, M.; Fornari, F.; Froysland, T.; Fuschino, F.; Galli, M.; Gianotti, F.; Labanti, C.; Lapshov, I.; Lazzarotto, F.; Lipari, P.; Longo, F.; Giuliani, A.; Marisaldi, M.; Mereghetti, S.; Morselli, A.; Pellizzoni, A.; Pacciani, L.; Perotti, F.; Piano, G.; Picozza, P.; Pilia, M.; Prest, M.; Rapisarda, M.; Rappoldi, A.; Sabatini, S.; Soffitta, P.; Striani, E.; Trifoglio, M.; Trois, A.; Vallazza, E.; Zambra, A.; Zanello, D.; Pittori, C.; Verrecchia, F.; Santolamazza, P.; Giommi, P.; Colafrancesco, S.; Salotti, L.; Agudo, I.; Aller, H. D.; Aller, M. F.; Arkharov, A. A.; Bach, U.; Bachev, R.; Beltrame, P.; Benítez, E.; Böttcher, M.; Buemi, C. S.; Calcidese, P.; Capezzali, D.; Carosati, D.; Chen, W. P.; Da Rio, D.; Di Paola, A.; Dolci, M.; Dultzin, D.; Forné, E.; Gómez, J. L.; Gurwell, M. A.; Hagen-Thorn, V. A.; Halkola, A.; Heidt, J.; Hiriart, D.; Hovatta, T.; Hsiao, H.-Y.; Jorstad, S. G.; Kimeridze, G.; Konstantinova, T. S.; Kopatskaya, E. N.; Koptelova, E.; Kurtanidze, O.; Lähteenmäki, A.; Larionov, V. M.; Leto, P.; Ligustri, R.; Lindfors, E.; Lopez, J. M.; Marscher, A. P.; Mujica, R.; Nikolashvili, M.; Nilsson, K.; Mommert, M.; Palma, N.; Pasanen, M.; Roca-Sogorb, M.; Ros, J. A.; Roustazadeh, P.; Sadun, A. C.; Saino, J.; Sigua, L.; Sorcia, M.; Takalo, L. O.; Tornikoski, M.; Trigilio, C.; Turchetti, R.; Umana, G.

    2010-03-01

    We report on 18 months of multiwavelength observations of the blazar 3C 454.3 (Crazy Diamond) carried out in the period 2007 July-2009 January. In particular, we show the results of the AGILE campaigns which took place on 2008 May-June, 2008 July-August, and 2008 October-2009 January. During the 2008 May-2009 January period, the source average flux was highly variable, with a clear fading trend toward the end of the period, from an average γ-ray flux F E>100 MeV >~ 200 × 10-8 photons cm-2 s-1 in 2008 May-June, to F E>100 MeV ~ 80 × 10-8 photons cm-2 s-1 in 2008 October-2009 January. The average γ-ray spectrum between 100 MeV and 1 GeV can be fit by a simple power law, showing a moderate softening (from ΓGRID ~ 2.0 to ΓGRID ~ 2.2) toward the end of the observing campaign. Only 3σ upper limits can be derived in the 20-60 keV energy band with Super-AGILE, because the source was considerably off-axis during the whole time period. In 2007 July-August and 2008 May-June, 3C 454.3 was monitored by Rossi X-ray Timing Explorer (RXTE). The RXTE/Proportional Counter Array (PCA) light curve in the 3-20 keV energy band shows variability correlated with the γ-ray one. The RXTE/PCA average flux during the two time periods is F 3-20 keV = 8.4 × 10-11 erg cm-2 s-1, and F 3-20 keV = 4.5 × 10-11 erg cm-2 s-1, respectively, while the spectrum (a power law with photon index ΓPCA = 1.65 ± 0.02) does not show any significant variability. Consistent results are obtained with the analysis of the RXTE/High-Energy X-Ray Timing Experiment quasi-simultaneous data. We also carried out simultaneous Swift observations during all AGILE campaigns. Swift/XRT detected 3C 454.3 with an observed flux in the 2-10 keV energy band in the range (0.9-7.5) × 10-11 erg cm-2 s-1 and a photon index in the range ΓXRT = 1.33-2.04. In the 15-150 keV energy band, when detected, the source has an average flux of about 5 mCrab. GASP-WEBT monitored 3C 454.3 during the whole 2007-2008 period in the radio

  20. THE 2010 VERY HIGH ENERGY {gamma}-RAY FLARE AND 10 YEARS OF MULTI-WAVELENGTH OBSERVATIONS OF M 87

    Energy Technology Data Exchange (ETDEWEB)

    Abramowski, A. [Institut fuer Experimentalphysik, Universitaet Hamburg, Luruper Chaussee 149, D 22761 Hamburg (Germany); Acero, F. [Laboratoire Univers et Particules de Montpellier, Universite Montpellier 2, CNRS/IN2P3, CC 72, Place Eugene Bataillon, F-34095 Montpellier Cedex 5 (France); Aharonian, F.; Bernloehr, K.; Bochow, A. [Max-Planck-Institut fuer Kernphysik, P.O. Box 103980, D 69029 Heidelberg (Germany); Akhperjanian, A. G. [National Academy of Sciences of the Republic of Armenia, 24 Marshall Baghramian Avenue, 0019 Yerevan (Armenia); Anton, G.; Balzer, A. [Physikalisches Institut, Universitaet Erlangen-Nuernberg, Erwin-Rommel-Str. 1, D 91058 Erlangen (Germany); Barnacka, A. [Nicolaus Copernicus Astronomical Center, ul. Bartycka 18, 00-716 Warsaw (Poland); Barres de Almeida, U. [Department of Physics, University of Durham, South Road, Durham DH1 3LE (United Kingdom); Becherini, Y. [Astroparticule et Cosmologie (APC), CNRS, Universite Paris 7 Denis Diderot, 10, rue Alice Domon et Leonie Duquet, F-75205 Paris Cedex 13 (France); Becker, J. [Institut fuer Theoretische Physik, Lehrstuhl IV: Weltraum und Astrophysik, Ruhr-Universitaet Bochum, D 44780 Bochum (Germany); Behera, B. [Landessternwarte, Universitaet Heidelberg, Koenigstuhl, D 69117 Heidelberg (Germany); Birsin, E. [Institut fuer Physik, Humboldt-Universitaet zu Berlin, Newtonstr. 15, D 12489 Berlin (Germany); Biteau, J. [Laboratoire Leprince-Ringuet, Ecole Polytechnique, CNRS/IN2P3, F-91128 Palaiseau (France); Boisson, C. [LUTH, Observatoire de Paris, CNRS, Universite Paris Diderot, 5 Place Jules Janssen, 92190 Meudon (France); Bolmont, J. [LPNHE, Universite Pierre et Marie Curie Paris 6, Universite Denis Diderot Paris 7, CNRS/IN2P3, 4 Place Jussieu, F-75252, Paris Cedex 5 (France); Bordas, P., E-mail: martin.raue@desy.de [Institut fuer Astronomie und Astrophysik, Universitaet Tuebingen, Sand 1, D 72076 Tuebingen (Germany); Collaboration: H.E.S.S. Collaboration; MAGIC Collaboration; VERITAS Collaboration; and others

    2012-02-20

    The giant radio galaxy M 87 with its proximity (16 Mpc), famous jet, and very massive black hole ((3 - 6) Multiplication-Sign 10{sup 9} M{sub Sun }) provides a unique opportunity to investigate the origin of very high energy (VHE; E > 100 GeV) {gamma}-ray emission generated in relativistic outflows and the surroundings of supermassive black holes. M 87 has been established as a VHE {gamma}-ray emitter since 2006. The VHE {gamma}-ray emission displays strong variability on timescales as short as a day. In this paper, results from a joint VHE monitoring campaign on M 87 by the MAGIC and VERITAS instruments in 2010 are reported. During the campaign, a flare at VHE was detected triggering further observations at VHE (H.E.S.S.), X-rays (Chandra), and radio (43 GHz Very Long Baseline Array, VLBA). The excellent sampling of the VHE {gamma}-ray light curve enables one to derive a precise temporal characterization of the flare: the single, isolated flare is well described by a two-sided exponential function with significantly different flux rise and decay times of {tau}{sup rise}{sub d} = (1.69 {+-} 0.30) days and {tau}{sup decay}{sub d} = (0.611 {+-} 0.080) days, respectively. While the overall variability pattern of the 2010 flare appears somewhat different from that of previous VHE flares in 2005 and 2008, they share very similar timescales ({approx}day), peak fluxes ({Phi}{sub >0.35TeV} {approx_equal} (1-3) Multiplication-Sign 10{sup -11} photons cm{sup -2} s{sup -1}), and VHE spectra. VLBA radio observations of 43 GHz of the inner jet regions indicate no enhanced flux in 2010 in contrast to observations in 2008, where an increase of the radio flux of the innermost core regions coincided with a VHE flare. On the other hand, Chandra X-ray observations taken {approx}3 days after the peak of the VHE {gamma}-ray emission reveal an enhanced flux from the core (flux increased by factor {approx}2; variability timescale <2 days). The long-term (2001-2010) multi-wavelength (MWL

  1. Paving the way to simultaneous multi-wavelength astronomy

    Science.gov (United States)

    Middleton, M. J.; Casella, P.; Gandhi, P.; Bozzo, E.; Anderson, G.; Degenaar, N.; Donnarumma, I.; Israel, G.; Knigge, C.; Lohfink, A.; Markoff, S.; Marsh, T.; Rea, N.; Tingay, S.; Wiersema, K.; Altamirano, D.; Bhattacharya, D.; Brandt, W. N.; Carey, S.; Charles, P.; Díaz Trigo, M.; Done, C.; Kotze, M.; Eikenberry, S.; Fender, R.; Ferruit, P.; Fürst, F.; Greiner, J.; Ingram, A.; Heil, L.; Jonker, P.; Komossa, S.; Leibundgut, B.; Maccarone, T.; Malzac, J.; McBride, V.; Miller-Jones, J.; Page, M.; Rossi, E. M.; Russell, D. M.; Shahbaz, T.; Sivakoff, G. R.; Tanaka, M.; Thompson, D. J.; Uemura, M.; Uttley, P.; van Moorsel, G.; van Doesburgh, M.; Warner, B.; Wilkes, B.; Wilms, J.; Woudt, P.

    2017-11-01

    Whilst astronomy as a science is historically founded on observations at optical wavelengths, studying the Universe in other bands has yielded remarkable discoveries, from pulsars in the radio, signatures of the Big Bang at submm wavelengths, through to high energy emission from accreting, gravitationally-compact objects and the discovery of gamma-ray bursts. Unsurprisingly, the result of combining multiple wavebands leads to an enormous increase in diagnostic power, but powerful insights can be lost when the sources studied vary on timescales shorter than the temporal separation between observations in different bands. In July 2015, the workshop ;Paving the way to simultaneous multi-wavelength astronomy; was held as a concerted effort to address this at the Lorentz Center, Leiden. It was attended by 50 astronomers from diverse fields as well as the directors and staff of observatories and spaced-based missions. This community white paper has been written with the goal of disseminating the findings of that workshop by providing a concise review of the field of multi-wavelength astronomy covering a wide range of important source classes, the problems associated with their study and the solutions we believe need to be implemented for the future of observational astronomy. We hope that this paper will both stimulate further discussion and raise overall awareness within the community of the issues faced in a developing, important field.

  2. MULTI-WAVELENGTH OBSERVATIONS OF SUPERNOVA 2011ei: TIME-DEPENDENT CLASSIFICATION OF TYPE IIb AND Ib SUPERNOVAE AND IMPLICATIONS FOR THEIR PROGENITORS

    Energy Technology Data Exchange (ETDEWEB)

    Milisavljevic, Dan; Margutti, Raffaella; Soderberg, Alicia M.; Chomiuk, Laura; Sanders, Nathan E. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Pignata, Giuliano; Bufano, Filomena [Departamento de Ciencias Fisicas, Universidad Andres Bello, Avda. Republica 252, Santiago (Chile); Fesen, Robert A.; Parrent, Jerod T. [Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Lab, Hanover, NH 03755 (United States); Parker, Stuart [Parkdale Observatory, 225 Warren Road, RDl Oxford, Canterbury 7495 (New Zealand); Mazzali, Paolo [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Strasse 1, D-85748 Garching (Germany); Pian, Elena [Kavli Institute for Theoretical Physics, Kohn Hall, University of California at Santa Barbara, Santa Barbara, CA 93106-4030 (United States); Pickering, Timothy; Buckley, David A. H.; Crawford, Steven M.; Gulbis, Amanda A. S.; Hettlage, Christian [South African Astronomical Observatory, P.O. Box 9, Observatory 7935, Cape Town (South Africa); Hooper, Eric; Nordsieck, Kenneth H. [Department of Astronomy, University of Wisconsin, Madison, WI 53706 (United States); O' Donoghue, Darragh, E-mail: dmilisav@cfa.harvard.edu [Southern African Large Telescope, P.O. Box 9, Observatory 7935, Cape Town (South Africa); and others

    2013-04-10

    We present X-ray, UV/optical, and radio observations of the stripped-envelope, core-collapse supernova (SN) 2011ei, one of the least luminous SNe IIb or Ib observed to date. Our observations begin with a discovery within {approx}1 day of explosion and span several months afterward. Early optical spectra exhibit broad, Type II-like hydrogen Balmer profiles that subside rapidly and are replaced by Type Ib-like He-rich features on a timescale of one week. High-cadence monitoring of this transition suggests absorption attributable to a high-velocity ({approx}> 12, 000 km s{sup -1}) H-rich shell, which is likely present in many Type Ib events. Radio observations imply a shock velocity of v Almost-Equal-To 0.13 c and a progenitor star average mass-loss rate of M-dot {approx}1.4 Multiplication-Sign 10{sup -5} M{sub sun} yr{sup -1} (assuming wind velocity v{sub w} = 10{sup 3} km s{sup -1}). This is consistent with independent constraints from deep X-ray observations with Swift-XRT and Chandra. Overall, the multi-wavelength properties of SN 2011ei are consistent with the explosion of a lower-mass (3-4 M{sub Sun }), compact (R{sub *} {approx}< 1 Multiplication-Sign 10{sup 11} cm), He-core star. The star retained a thin hydrogen envelope at the time of explosion, and was embedded in an inhomogeneous circumstellar wind suggestive of modest episodic mass loss. We conclude that SN 2011ei's rapid spectral metamorphosis is indicative of time-dependent classifications that bias estimates of the relative explosion rates for Type IIb and Ib objects, and that important information about a progenitor star's evolutionary state and mass loss immediately prior to SN explosion can be inferred from timely multi-wavelength observations.

  3. Contemporaneous multi-wavelength observations of the gamma-ray emitting active galaxy IC 310. New clues on particle acceleration in extragalactic jets

    Energy Technology Data Exchange (ETDEWEB)

    Glawion, Dorit

    2015-05-08

    In this thesis, the broad band emission, especially in the gamma-ray and radio band, of the active galaxy IC 310 located in the Perseus cluster of galaxies was investigated. The main experimental methods were Cherenkov astronomy using the MAGIC telescopes and high resolution very long baseline interferometry (VLBI) at radio frequencies (MOJAVE, EVN). Additionally, data of the object in different energy bands were studied and a multi-wavelength campaign has been organized and conducted. During the campaign, an exceptional bright gamma-ray flare at TeV energies was found with the MAGIC telescopes. The results were compared to theoretical acceleration and emission models for explaining the high energy radiation of active galactic nuclei. Many open questions regarding the particle acceleration to very high energies in the jets of active galactic nuclei, the particle content of the jets, or how the jets are launched, were addressed in this thesis by investigating the variability of IC 310 in the very high energy band. It is argued that IC310 was originally mis-classified as a head-tail radio galaxy. Instead, it shows a variability behavior in the radio, X-ray, and gamma-ray band similar to the one found for blazars. These are active galactic nuclei that are characterized by flux variability in all observed energy bands and at all observed time scales. They are viewed at a small angle between the jet axis and the line-of-sight. Thus, strong relativistic beaming influences the variability properties of blazars. Observations of IC 310 with the European VLBI Network helped to find limits for the angle between the jet axis and the line-of-sight, namely 10 - 20 . This places IC 310 at the borderline between radio galaxies (larger angles) and blazars (smaller angles). During the gamma-ray outburst detected at the beginning of the multi-wavelength campaign, flux variability as short as minutes was measured. The spectrum during the flare can be described by a simple power

  4. Test of models of the cosmic infrared background with multiwavelength observations of the blazar 1ES 1218+30.4 in 2009

    Energy Technology Data Exchange (ETDEWEB)

    Archambault, S. [Physics Department, McGill University, Montreal, QC H3A 2T8 (Canada); Arlen, T.; Aune, T. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Beilicke, M.; Buckley, J. H.; Bugaev, V.; Dickherber, R. [Department of Physics, Washington University, St. Louis, MO 63130 (United States); Benbow, W. [Fred Lawrence Whipple Observatory, Harvard-Smithsonian Center for Astrophysics, Amado, AZ 85645 (United States); Bird, R.; Collins-Hughes, E. [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Böttcher, M. [Department of Physics and Astronomy, Ohio University, Clippinger 339, Athens, OH 45701-2979 (United States); Bouvier, A. [Santa Cruz Institute for Particle Physics and Department of Physics, University of California, Santa Cruz, CA 95064 (United States); Ciupik, L. [Astronomy Department, Adler Planetarium and Astronomy Museum, Chicago, IL 60605 (United States); Connolly, M. P. [School of Physics, National University of Ireland Galway, University Road, Galway (Ireland); Cui, W.; Feng, Q. [Department of Physics, Purdue University, West Lafayette, IN 47907 (United States); Dumm, J. [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States); Errando, M. [Department of Physics and Astronomy, Barnard College, Columbia University, New York, NY 10027 (United States); Falcone, A. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Federici, S., E-mail: krawcz@wuphys.wustl.edu [DESY, Platanenallee 6, D-15738 Zeuthen (Germany); and others

    2014-06-20

    We present the results of a multi-wavelength campaign targeting the blazar 1ES 1218+30.4 with observations with the 1.3 m McGraw-Hill optical telescope, the Rossi X-ray Timing Explorer (RXTE), the Fermi Gamma-Ray Space Telescope, and the Very Energetic Radiation Imaging Telescope Array System (VERITAS). The RXTE and VERITAS observations were spread over a 13 day period and revealed clear evidence for flux variability, and a strong X-ray and γ-ray flare on 2009 February 26 (MJD 54888). The campaign delivered a well-sampled broadband energy spectrum with simultaneous RXTE and VERITAS very high energy (VHE, >100 GeV) observations, as well as contemporaneous optical and Fermi observations. The 1ES 1218+30.4 broadband energy spectrum—the first with simultaneous X-ray and VHE γ-ray energy spectra—is of particular interest as the source is located at a high cosmological redshift for a VHE source (z = 0.182), leading to strong absorption of VHE gamma rays by photons from the optical/infrared extragalactic background light (EBL) via γ{sub VHE} + γ{sub EBL} → e {sup +} e {sup –} pair-creation processes. We model the data with a one-zone synchrotron self-Compton (SSC) emission model and with the extragalactic absorption predicted by several recent EBL models. We find that the observations are consistent with the SSC scenario and all the EBL models considered in this work. We discuss observational and theoretical avenues to improve on the EBL constraints.

  5. Subdigital setae of chameleon feet: friction-enhancing microstructures for a wide range of substrate roughness.

    Science.gov (United States)

    Spinner, Marlene; Westhoff, Guido; Gorb, Stanislav N

    2014-06-27

    Hairy adhesive systems of microscopic setae with triangular flattened tips have evolved convergently in spiders, insects and arboreal lizards. The ventral sides of the feet and tails in chameleons are also covered with setae. However, chameleon setae feature strongly elongated narrow spatulae or fibrous tips. The friction enhancing function of these microstructures has so far only been demonstrated in contact with glass spheres. In the present study, the frictional properties of subdigital setae of Chamaeleo calyptratus were measured under normal forces in the physical range on plane substrates having different roughness. We showed that chameleon setae maximize friction on a wide range of substrate roughness. The highest friction was measured on asperities of 1 μm. However, our observations of the climbing ability of Ch. calyptratus on rods of different diameters revealed that also claws and grasping feet are additionally responsible for the force generation on various substrates during locomotion.

  6. An abundance of small exoplanets around stars with a wide range of metallicities

    DEFF Research Database (Denmark)

    Buchhave, Lars A.; Latham, David W.; Johansen, Anders

    2012-01-01

    on average a metallicity close to that of the Sun), whereas large planets preferentially form around stars with higher metallicities. This observation suggests that terrestrial planets may be widespread in the disk of the Galaxy, with no special requirement of enhanced metallicity for their formation.......The abundance of heavy elements (metallicity) in the photospheres of stars similar to the Sun provides a fossil record of the chemical composition of the initial protoplanetary disk. Metal-rich stars are much more likely to harbour gas giant planets, supporting the model that planets form...... of the host stars of 226 small exoplanet candidates discovered by NASAs Kepler mission, including objects that are comparable in size to the terrestrial planets in the Solar System. We find that planets with radii less than four Earth radii form around host stars with a wide range of metallicities (but...

  7. Multi-wavelength Observations of the Flaring Gamma-ray Blazar 3C 66A in 2008 October

    Science.gov (United States)

    Abdo, A. A.; Ackermann, M.; Ajello, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R. D.; Bonamente, E.; Borgland, A. W.; Bouvier, A.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Carrigan, S.; Casandjian, J. M.; Cavazzuti, E.; Cecchi, C.; Çelik, Ö.; Charles, E.; Chekhtman, A.; Cheung, C. C.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Conrad, J.; Costamante, L.; Cutini, S.; Davis, D. S.; Dermer, C. D.; de Palma, F.; Digel, S. W.; do Couto e Silva, E.; Drell, P. S.; Dubois, R.; Dumora, D.; Favuzzi, C.; Fegan, S. J.; Fortin, P.; Frailis, M.; Fuhrmann, L.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Germani, S.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Hadasch, D.; Hayashida, M.; Hays, E.; Horan, D.; Hughes, R. E.; Itoh, R.; Jóhannesson, G.; Johnson, A. S.; Johnson, T. J.; Johnson, W. N.; Kamae, T.; Katagiri, H.; Kataoka, J.; Knödlseder, J.; Kuss, M.; Lande, J.; Latronico, L.; Lee, S.-H.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Makeev, A.; Mazziotta, M. N.; McEnery, J. E.; Mehault, J.; Michelson, P. F.; Mizuno, T.; Moiseev, A. A.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nakamori, T.; Naumann-Godo, M.; Nestoras, I.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohsugi, T.; Okumura, A.; Omodei, N.; Orlando, E.; Ormes, J. F.; Ozaki, M.; Paneque, D.; Panetta, J. H.; Parent, D.; Pelassa, V.; Pepe, M.; Pesce-Rollins, M.; Piron, F.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Reimer, A.; Reimer, O.; Reyes, L. C.; Ripken, J.; Ritz, S.; Romani, R. W.; Roth, M.; Sadrozinski, H. F.-W.; Sanchez, D.; Sander, A.; Scargle, J. D.; Sgrò, C.; Shaw, M. S.; Smith, P. D.; Spandre, G.; Spinelli, P.; Strickman, M. S.; Suson, D. J.; Takahashi, H.; Tanaka, T.; Thayer, J. B.; Thayer, J. G.; Thompson, D. J.; Tibaldo, L.; Torres, D. F.; Tosti, G.; Tramacere, A.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Vilchez, N.; Vitale, V.; Waite, A. P.; Wang, P.; Winer, B. L.; Wood, K. S.; Yang, Z.; Ylinen, T.; Ziegler, M.; Acciari, V. A.; Aliu, E.; Arlen, T.; Aune, T.; Beilicke, M.; Benbow, W.; Böttcher, M.; Boltuch, D.; Bradbury, S. M.; Buckley, J. H.; Bugaev, V.; Byrum, K.; Cannon, A.; Cesarini, A.; Christiansen, J. L.; Ciupik, L.; Cui, W.; de la Calle Perez, I.; Dickherber, R.; Errando, M.; Falcone, A.; Finley, J. P.; Finnegan, G.; Fortson, L.; Furniss, A.; Galante, N.; Gall, D.; Gillanders, G. H.; Godambe, S.; Grube, J.; Guenette, R.; Gyuk, G.; Hanna, D.; Holder, J.; Hui, C. M.; Humensky, T. B.; Imran, A.; Kaaret, P.; Karlsson, N.; Kertzman, M.; Kieda, D.; Konopelko, A.; Krawczynski, H.; Krennrich, F.; Lang, M. J.; LeBohec, S.; Maier, G.; McArthur, S.; McCann, A.; McCutcheon, M.; Moriarty, P.; Mukherjee, R.; Ong, R. A.; Otte, A. N.; Pandel, D.; Perkins, J. S.; Pichel, A.; Pohl, M.; Quinn, J.; Ragan, K.; Reynolds, P. T.; Roache, E.; Rose, H. J.; Schroedter, M.; Sembroski, G. H.; Senturk, G. Demet; Smith, A. W.; Steele, D.; Swordy, S. P.; Tešić, G.; Theiling, M.; Thibadeau, S.; Varlotta, A.; Vassiliev, V. V.; Vincent, S.; Wakely, S. P.; Ward, J. E.; Weekes, T. C.; Weinstein, A.; Weisgarber, T.; Williams, D. A.; Wissel, S.; Wood, M.; Villata, M.; Raiteri, C. M.; Gurwell, M. A.; Larionov, V. M.; Kurtanidze, O. M.; Aller, M. F.; Lähteenmäki, A.; Chen, W. P.; Berduygin, A.; Agudo, I.; Aller, H. D.; Arkharov, A. A.; Bach, U.; Bachev, R.; Beltrame, P.; Benítez, E.; Buemi, C. S.; Dashti, J.; Calcidese, P.; Capezzali, D.; Carosati, D.; Da Rio, D.; Di Paola, A.; Diltz, C.; Dolci, M.; Dultzin, D.; Forné, E.; Gómez, J. L.; Hagen-Thorn, V. A.; Halkola, A.; Heidt, J.; Hiriart, D.; Hovatta, T.; Hsiao, H.-Y.; Jorstad, S. G.; Kimeridze, G. N.; Konstantinova, T. S.; Kopatskaya, E. N.; Koptelova, E.; Leto, P.; Ligustri, R.; Lindfors, E.; Lopez, J. M.; Marscher, A. P.; Mommert, M.; Mujica, R.; Nikolashvili, M. G.; Nilsson, K.; Palma, N.; Pasanen, M.; Roca-Sogorb, M.; Ros, J. A.; Roustazadeh, P.; Sadun, A. C.; Saino, J.; Sigua, L. A.; Sillanää, A.; Sorcia, M.; Takalo, L. O.; Tornikoski, M.; Trigilio, C.; Turchetti, R.; Umana, G.; Belloni, T.; Blake, C. H.; Bloom, J. S.; Angelakis, E.; Fumagalli, M.; Hauser, M.; Prochaska, J. X.; Riquelme, D.; Sievers, A.; Starr, D. L.; Tagliaferri, G.; Ungerechts, H.; Wagner, S.; Zensus, J. A.; Fermi LAT Collaboration; VERITAS Collaboration; GASP-WEBT Consortium

    2011-01-01

    The BL Lacertae object 3C 66A was detected in a flaring state by the Fermi Large Area Telescope (LAT) and VERITAS in 2008 October. In addition to these gamma-ray observations, F-GAMMA, GASP-WEBT, PAIRITEL, MDM, ATOM, Swift, and Chandra provided radio to X-ray coverage. The available light curves show variability and, in particular, correlated flares are observed in the optical and Fermi-LAT gamma-ray band. The resulting spectral energy distribution can be well fitted using standard leptonic models with and without an external radiation field for inverse Compton scattering. It is found, however, that only the model with an external radiation field can accommodate the intra-night variability observed at optical wavelengths.

  8. EROs found behind lensing clusters: II. Empirical properties, classification, and SED modelling based on multi-wavelength observations

    NARCIS (Netherlands)

    Hempel, A.; Schaerer, D.; Egami, E.; Pelló, R.; Wise, M.; Richard, J.; Le Borgne, J.F.; Kneib, J.P.

    2008-01-01

    Aims. We study the properties and nature of extremely red galaxies (FRO, R-K >= 5.6) found behind two lensing clusters and compare them with other known galaxy populations. Methods. New HST/ACS, Spitzer (TRAC and MIPS), and Chandra/ACIS observations of the two lensing clusters Abell 1835 and AC 114

  9. Novel method of drizzle formation observation at large horizontal scales using multi-wavelength satellite imagery simulation

    NARCIS (Netherlands)

    Stepanov, I.; Russchenberg, H.W.J.

    2014-01-01

    The observations of on-board satellite imaging radiometers are representative of a far-reaching two-dimensional cloud top properties, however with a cutback in the capacity of profiling the cloud vertically. A combination of simulated radiances calculated at the top of the cloud in the near-infrared

  10. Vertically resolved light-absorption characteristics and the influence of relative humidity on particle properties: Multiwavelength Raman lidar observations of East Asian aerosol types over Korea

    Science.gov (United States)

    Noh, Young M.; Müller, Detlef; Mattis, Ina; Lee, Hanlim; Kim, Young J.

    2011-03-01

    Optical and microphysical particle properties, including the particle single-scattering albedo, were derived from multiwavelength aerosol Raman lidar observations at Gwangju (35.10°N, 126.53°E), and Anmyeon Island (36.54°N, 126.33°E), South Korea. The results present aerosol properties in various heights of the atmospheric aerosol layers on 12 different measurement days. The measurement cases differ in terms of aerosol loading as well as aerosol types (long-range transported urban/industrial haze from China, regional/local haze that mainly originated from the Korean peninsula, and smoke from forest fires in east Siberia). The origin of the particle plumes was determined from chemical transport modeling with the FLEXPART model. We find comparably clear differences between the optical and microphysical properties of the aerosol types. Local haze aerosols show effective radii of 0.32 ± 0.02 μm at relative humidity of 60-80%. The effective radii of urban/industrial haze and smoke aerosols are approximately 0.26 μm and 0.27 μm at relative humidity of 35-60%. Light absorption, expressed in terms of single-scattering albedo, is 0.87 ± 0.02 (at 532 nm) for urban/industrial haze from China. This value is considerably lower than the single-scattering albedo of smoke aerosols from Siberia and northern China (0.92 at 532 nm) and of regional/local haze aerosols (0.97 ± 0.01 at 532 nm). We find a hygroscopic growth factor (from relative humidity of 30% to relative humidity of 85%) of 1.49 ± 0.36, if we consider all measurements.

  11. Multiwavelength observations of the γ-ray flaring quasar S4 1030+61 in 2009-2014

    Science.gov (United States)

    Kravchenko, E. V.; Kovalev, Y. Y.; Hovatta, T.; Ramakrishnan, V.

    2016-11-01

    We present a study of the parsec-scale multifrequency properties of the quasar S4 1030+61 during a prolonged radio and γ-ray activity. Observations were performed within Fermi γ-ray telescope, Owens Valley Radio Observatory 40-m telescope and MOJAVE Very Long Baseline Array (VLBA) monitoring programmes, covering five years from 2009. The data are supplemented by four-epoch VLBA observations at 5, 8, 15, 24 and 43 GHz, which were triggered by the bright γ-ray flare, registered in the quasar in 2010. The S4 1030+61 jet exhibits an apparent superluminal velocity of (6.4 ± 0.4)c and does not show ejections of new components in the observed period, while decomposition of the radio light curve reveals nine prominent flares. The measured variability parameters of the source show values typical for Fermi-detected quasars. Combined analysis of radio and γ-ray emission implies a spatial separation between emitting regions at these bands of about 12 pc and locates the γ-ray emission within a parsec from the central engine. We detected changes in the value and direction of the linear polarization and the Faraday rotation measure. The value of the intrinsic brightness temperature of the core is above the equipartition state, while its value as a function of distance from the core is well approximated by the power law. Altogether these results show that the radio flaring activity of the quasar is accompanied by injection of relativistic particles and energy losses at the jet base, while S4 1030+61 has a stable, straight jet well described by standard conical jet theories.

  12. 4.5 YEARS OF MULTI-WAVELENGTH OBSERVATIONS OF MRK 421 DURING THE ARGO-YBJ AND FERMI COMMON OPERATION TIME

    Energy Technology Data Exchange (ETDEWEB)

    Bartoli, B.; Catalanotti, S.; Piazzoli, B. D’Ettorre; Girolamo, T. Di [Dipartimento di Fisica dell’Università di Napoli “Federico II,” Complesso Universitario di Monte Sant’Angelo, via Cinthia, I-80126 Napoli (Italy); Bernardini, P.; D’Amone, A.; Mitri, I. De [Dipartimento Matematica e Fisica “Ennio De Giorgi,” Università del Salento, via per Arnesano, I-73100 Lecce (Italy); Bi, X. J.; Cao, Z.; Chen, S. Z.; Feng, Zhaoyang; Gou, Q. B.; Guo, Y. Q. [Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, P.O. Box 918, 100049 Beijing (China); Chen, T. L.; Danzengluobu [Tibet University, 850000 Lhasa, Xizang (China); Cui, S. W. [Hebei Normal University, 050024, Shijiazhuang Hebei (China); Dai, B. Z. [Yunnan University, 2 North Cuihu Road, 650091 Kunming, Yunnan (China); Sciascio, G. Di [Istituto Nazionale di Fisica Nucleare, Sezione di Roma Tor Vergata, via della Ricerca Scientifica 1, I-00133 Roma (Italy); Feng, C. F. [Shandong University, 250100 Jinan, Shandong (China); Feng, Zhenyong, E-mail: chensz@ihep.ac.cn [Southwest Jiaotong University, 610031 Chengdu, Sichuan (China); Collaboration: ARGO-YBJ Collaboration; and others

    2016-01-15

    We report on the extensive multi-wavelength observations of the blazar Markarian 421 (Mrk 421) covering radio to γ-rays, during the 4.5 year period of ARGO-YBJ and Fermi common operation time, from 2008 August to 2013 February. These long-term observations, extending over an energy range of 18 orders of magnitude, provide a unique chance to study the variable emission of Mrk 421. In particular, due to the ARGO-YBJ and Fermi data, the entire energy range from 100 MeV to 10 TeV is covered without any gap. In the observation period, Mrk 421 showed both low- and high-activity states at all wavebands. The correlations among flux variations in different wavebands were analyzed. The X-ray flux is clearly correlated with the TeV γ-ray flux, while the GeV γ-rays only show a partial correlation with the TeV γ-rays. Radio and UV fluxes seem to be weakly or not correlated with the X-ray and γ-ray fluxes. Seven large flares, including five X-ray flares and two GeV γ-ray flares with variable durations (3–58 days), and one X-ray outburst phase were identified and used to investigate the variation of the spectral energy distribution with respect to a relative quiescent phase. During the outburst phase and the seven flaring episodes, the peak energy in X-rays is observed to increase from sub-keV to a few keV. The TeV γ-ray flux increases up to 0.9–7.2 times the flux of the Crab Nebula. The behavior of GeV γ-rays is found to vary depending on the flare, a feature that leads us to classify flares into three groups according to the GeV flux variation. Finally, the one-zone synchrotron self-Compton model was adopted to describe the emission spectra. Two out of three groups can be satisfactorily described using injected electrons with a power-law spectral index around 2.2, as expected from relativistic diffuse shock acceleration, whereas the remaining group requires a harder injected spectrum. The underlying physical mechanisms responsible for different groups may be

  13. Ground-based network observation using Mie-Raman lidars and multi-wavelength Raman lidars and algorithm to retrieve distributions of aerosol components

    Science.gov (United States)

    Nishizawa, Tomoaki; Sugimoto, Nobuo; Matsui, Ichiro; Shimizu, Atsushi; Hara, Yukari; Itsushi, Uno; Yasunaga, Kazuaki; Kudo, Rei; Kim, Sang-Woo

    2017-02-01

    We improved two-wavelength polarization Mie-scattering lidars at several main sites of the Asian dust and aerosol lidar observation network (AD-Net) by adding a nitrogen Raman scatter measurement channel at 607 nm and have conducted ground-based network observation with the improved Mie-Raman lidars (MRL) in East Asia since 2009. This MRL provides 1α+2β+1δ data at nighttime: extinction coefficient (α532), backscatter coefficient (β532), and depolarization ratio (δ532) of particles at 532 nm and an attenuated backscatter coefficient at 1064 nm (βat,1064). Furthermore, we developed a Multi-wavelength Mie-Raman lidar (MMRL) providing 2α+3β+2δ data (α at 355 and 532 nm; β at 355 and 532; βat at 1064 nm; and δ at 355 and 532 nm) and constructed MMRLs at several main sites of the AD-Net. We identified an aerosol-rich layer and height of the planetary boundary layer (PBL) using βat,1064 data, and derived aerosol optical properties (AOPs, for example, αa, βa, δa, and lidar ratio (Sa)). We demonstrated that AOPs cloud be derived with appropriate accuracy. Seasonal means of AOPs in the PBL were evaluated for each MRL observation site using three-year data from 2010 through 2012; the AOPs changed according to each season and region. For example, Sa,532 at Fukue, Japan, were 44±15 sr in winter and 49±17 in summer; those at Seoul, Korea, were 56±18 sr in winter and 62±15 sr in summer. We developed an algorithm to estimate extinction coefficients at 532 nm for black carbon, dust, sea-salt, and air-pollution aerosols consisting of a mixture of sulfate, nitrate, and organic-carbon substances using the 1α532+2β532 and 1064+1δ532 data. With this method, we assume an external mixture of aerosol components and prescribe their size distributions, refractive indexes, and particle shapes. We applied the algorithm to the observed data to demonstrate the performance of the algorithm and determined the vertical structure for each aerosol component.

  14. Multiwavelength Observations of V2775 Ori, an Outbursting Protostar in L 1641: Exploring the Edge of the FU Orionis Regime

    Science.gov (United States)

    Fischer, William J.; Megeath, S. Thomas; Tobin, John J.; Stutz, Amelia M.; Ali, Babar; Remming, Ian; Kounkel, Marina; Stanke, Thomas; Osorio, Mayra; Henning, Thomas; Manoj, P.; Wilson, T. L.

    2012-09-01

    Individual outbursting young stars are important laboratories for studying the physics of episodic accretion and the extent to which this phenomenon can explain the luminosity distribution of protostars. We present new and archival data for V2775 Ori (HOPS 223), a protostar in the L 1641 region of the Orion molecular clouds that was discovered by Caratti o Garatti et al. to have recently undergone an order-of-magnitude increase in luminosity. Our near-infrared spectra of the source have strong blueshifted He I λ10830 absorption, strong H2O and CO absorption, and no H I emission, all typical of FU Orionis sources. With data from the Infrared Telescope Facility, the Two Micron All Sky Survey, the Hubble Space Telescope, Spitzer, the Wide-field Infrared Survey Explorer, Herschel, and the Atacama Pathfinder Experiment that span from 1 to 70 μm pre-outburst and from 1 to 870 μm post-outburst, we estimate that the outburst began between 2005 April and 2007 March. We also model the pre- and post-outburst spectral energy distributions of the source, finding it to be in the late stages of accreting its envelope with a disk-to-star accretion rate that increased from ~2 × 10-6 M ⊙ yr-1 to ~10-5 M ⊙ yr-1 during the outburst. The post-outburst luminosity at the epoch of the FU Orionis-like near-IR spectra is 28 L ⊙, making V2775 Ori the least luminous documented FU Orionis outburster with a protostellar envelope. The existence of low-luminosity outbursts supports the notion that a range of episiodic accretion phenomena can partially explain the observed spread in protostellar luminosities.

  15. Fermi Large Area Telescope and Multi-wavelength Observations of the Flaring Activity of PKS 1510-089 between 2008 September and 2009 June

    Science.gov (United States)

    Abdo, A. A.; Ackermann, M.; Agudo, I.; Ajello, M.; Allafort, A.; Aller, H. D.; Aller, M. F.; Antolini, E.; Arkharov, A. A.; Axelsson, M.; Bach, U.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berdyugin, A.; Berenji, B.; Blandford, R. D.; Blinov, D. A.; Bloom, E. D.; Boettcher, M.; Bonamente, E.; Borgland, A. W.; Bouvier, A.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Buehler, R.; Buemi, C. S.; Burnett, T. H.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Carosati, D.; Carrigan, S.; Casandjian, J. M.; Cavazzuti, E.; Cecchi, C.; Çelik, Ö.; Chekhtman, A.; Chen, W. P.; Cheung, C. C.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Conrad, J.; Corbel, S.; Costamante, L.; Dermer, C. D.; de Angelis, A.; de Palma, F.; Donato, D.; Silva, E. do Couto e.; Drell, P. S.; Dubois, R.; Dumora, D.; Farnier, C.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Focke, W. B.; Forné, E.; Fortin, P.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Germani, S.; Giebels, B.; Giglietto, N.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Grove, J. E.; Guiriec, S.; Gurwell, M. A.; Gusbar, C.; Gómez, J. L.; Hadasch, D.; Hagen-Thorn, V. A.; Hayashida, M.; Hays, E.; Horan, D.; Hughes, R. E.; Jóhannesson, G.; Johnson, A. S.; Johnson, W. N.; Kamae, T.; Katagiri, H.; Kataoka, J.; Kawai, N.; Kimeridze, G.; Knödlseder, J.; Konstantinova, T. S.; Kopatskaya, E. N.; Koptelova, E.; Kovalev, Y. Y.; Kurtanidze, O. M.; Kuss, M.; Lahteenmaki, A.; Lande, J.; Larionov, V. M.; Larionova, E. G.; Larionova, L. V.; Larsson, S.; Latronico, L.; Lee, S.-H.; Leto, P.; Lister, M. L.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Makeev, A.; Massaro, E.; Mazziotta, M. N.; McConville, W.; McEnery, J. E.; McHardy, I. M.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monte, C.; Monzani, M. E.; Morozova, D. A.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Naumann-Godo, M.; Nikolashvili, M. G.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohno, M.; Ohsugi, T.; Okumura, A.; Omodei, N.; Orlando, E.; Ormes, J. F.; Ozaki, M.; Paneque, D.; Panetta, J. H.; Parent, D.; Pasanen, M.; Pelassa, V.; Pepe, M.; Pesce-Rollins, M.; Piron, F.; Porter, T. A.; Pushkarev, A. B.; Rainò, S.; Raiteri, C. M.; Rando, R.; Razzano, M.; Reimer, A.; Reimer, O.; Reinthal, R.; Ripken, J.; Ritz, S.; Roca-Sogorb, M.; Rodriguez, A. Y.; Roth, M.; Roustazadeh, P.; Ryde, F.; Sadrozinski, H. F.-W.; Sander, A.; Scargle, J. D.; Sgrò, C.; Sigua, L. A.; Smith, P. D.; Sokolovsky, K.; Spandre, G.; Spinelli, P.; Starck, J.-L.; Strickman, M. S.; Suson, D. J.; Takahashi, H.; Takahashi, T.; Takalo, L. O.; Tanaka, T.; Taylor, B.; Thayer, J. B.; Thayer, J. G.; Thompson, D. J.; Tibaldo, L.; Tornikoski, M.; Torres, D. F.; Tosti, G.; Tramacere, A.; Trigilio, C.; Troitsky, I. S.; Umana, G.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Vilchez, N.; Villata, M.; Vitale, V.; Waite, A. P.; Wang, P.; Winer, B. L.; Wood, K. S.; Yang, Z.; Ylinen, T.; Ziegler, M.

    2010-10-01

    We report on the multi-wavelength observations of PKS 1510-089 (a flat spectrum radio quasar (FSRQ) at z = 0.361) during its high activity period between 2008 September and 2009 June. During this 11 month period, the source was characterized by a complex variability at optical, UV, and γ-ray bands, on timescales down to 6-12 hr. The brightest γ-ray isotropic luminosity, recorded on 2009 March 26, was sime2 × 1048 erg s-1. The spectrum in the Fermi Large Area Telescope energy range shows a mild curvature described well by a log-parabolic law, and can be understood as due to the Klein-Nishina effect. The γ-ray flux has a complex correlation with the other wavelengths. There is no correlation at all with the X-ray band, a weak correlation with the UV, and a significant correlation with the optical flux. The γ-ray flux seems to lead the optical one by about 13 days. From the UV photometry, we estimated a black hole mass of sime5.4 × 108 M sun and an accretion rate of sime0.5 M sun yr-1. Although the power in the thermal and non-thermal outputs is smaller compared to the very luminous and distant FSRQs, PKS 1510-089 exhibits a quite large Compton dominance and a prominent big blue bump (BBB) as observed in the most powerful γ-ray quasars. The BBB was still prominent during the historical maximum optical state in 2009 May, but the optical/UV spectral index was softer than in the quiescent state. This seems to indicate that the BBB was not completely dominated by the synchrotron emission during the highest optical state. We model the broadband spectrum assuming a leptonic scenario in which the inverse Compton emission is dominated by the scattering of soft photons produced externally to the jet. The resulting model-dependent jet energetic content is compatible with a scenario in which the jet is powered by the accretion disk, with a total efficiency within the Kerr black hole limit.

  16. Study of the blazar AO 0235+164 during the multi-wavelength observation period from October 2008 to February 2009

    Energy Technology Data Exchange (ETDEWEB)

    Rainò, S. [INFN – Sezione di Bari (Italy); Madejski, G.; Couto e Silva, E. do [W.W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Gargano, F. [INFN – Sezione di Bari (Italy); Reyes, L. [Department of Physics, California Polytechnic State University, San Luis Obispo, CA 93401 (United States); Nalewajko, K. [Nicolaus Copernicus Astronomical Center, 00-716 Warsaw (Poland); University of Colorado, 440 UCB, Boulder, CO 80309 (United States); Sikora, M. [Nicolaus Copernicus Astronomical Center, 00-716 Warsaw (Poland)

    2013-06-15

    AO 0235+164 is one of the most studied and monitored BL Lac objects in the sky. Since the launch of Fermi, the source has been monitored in the gamma-ray band by Fermi Large Area Telescope. Starting in October 2008, AO 0235+164 showed an increasing activity in gamma-rays that led to a multi-wavelength campaign with instruments in the radio, near-infrared, optical, UV and X-ray bands. We present here the results of the analysis of the multi-wavelength data collected during the flaring period: the high variability properties of this source and the SED built from radio frequencies to gamma-rays are shown, and are interpreted in the context of well-known blazar emission models [Ackermann, M. et al. 2012, ApJ 751, 159].

  17. An abundance of small exoplanets around stars with a wide range of metallicities.

    Science.gov (United States)

    Buchhave, Lars A; Latham, David W; Johansen, Anders; Bizzarro, Martin; Torres, Guillermo; Rowe, Jason F; Batalha, Natalie M; Borucki, William J; Brugamyer, Erik; Caldwell, Caroline; Bryson, Stephen T; Ciardi, David R; Cochran, William D; Endl, Michael; Esquerdo, Gilbert A; Ford, Eric B; Geary, John C; Gilliland, Ronald L; Hansen, Terese; Isaacson, Howard; Laird, John B; Lucas, Philip W; Marcy, Geoffrey W; Morse, Jon A; Robertson, Paul; Shporer, Avi; Stefanik, Robert P; Still, Martin; Quinn, Samuel N

    2012-06-13

    The abundance of heavy elements (metallicity) in the photospheres of stars similar to the Sun provides a 'fossil' record of the chemical composition of the initial protoplanetary disk. Metal-rich stars are much more likely to harbour gas giant planets, supporting the model that planets form by accumulation of dust and ice particles. Recent ground-based surveys suggest that this correlation is weakened for Neptunian-sized planets. However, how the relationship between size and metallicity extends into the regime of terrestrial-sized exoplanets is unknown. Here we report spectroscopic metallicities of the host stars of 226 small exoplanet candidates discovered by NASA's Kepler mission, including objects that are comparable in size to the terrestrial planets in the Solar System. We find that planets with radii less than four Earth radii form around host stars with a wide range of metallicities (but on average a metallicity close to that of the Sun), whereas large planets preferentially form around stars with higher metallicities. This observation suggests that terrestrial planets may be widespread in the disk of the Galaxy, with no special requirement of enhanced metallicity for their formation.

  18. Novel Absolute Displacement Sensor with Wide Range Based on Malus Law

    Directory of Open Access Journals (Sweden)

    Yonggang Lin

    2009-12-01

    Full Text Available The paper presents a novel wide range absolute displacement sensor based on polarized light detection principle. The sensor comprises of two sets of polarized light detecting systems which are coupled by pulleys. The inherent disadvantage in optic system like light source intensity drift is solved and absolute measurement with wide-range is achieved. A prototype and the relevant test bed have been built. The test results are in good agreement with expectation. Its measurement range is 540 mm, and its linearity is better than 0.05%.

  19. The wide-range ejector flowmeter: calibrated gas evacuation comprising both high and low gas flows.

    Science.gov (United States)

    Waaben, J; Brinkløv, M M; Jørgensen, S

    1984-11-01

    The wide-range ejector flowmeter is an active scavenging system applying calibrated gas removal directly to the anaesthetic circuit. The evacuation rate can be adjusted on the flowmeter under visual control using the calibration scale ranging from 200 ml X min-1 to 151 X min-1. The accuracy of the calibration was tested on three ejector flowmeters at 12 different presettings. The percentage deviation from presetting varied from + 18 to - 19.4 per cent. The ejector flowmeter enables the provision of consistent and accurately calibrated extraction of waste gases and is applicable within a wide range of fresh gas flows.

  20. Satellite estimates of wide-range suspended sediment concentrations in Changjiang (Yangtze) estuary using MERIS data

    NARCIS (Netherlands)

    Shen, F.; Verhoef, W.; Zhou, Y.; Salama, M.S.; Liu, X.

    2010-01-01

    The Changjiang (Yangtze) estuarine and coastal waters are characterized by suspended sediments over a wide range of concentrations from 20 to 2,500 mg l-1. Suspended sediment plays important roles in the estuarine and coastal system and environment. Previous algorithms for satellite estimates of

  1. Model Study of Wave Overtopping of Marine Structure for a Wide Range of Geometric Parameters

    DEFF Research Database (Denmark)

    Kofoed, Jens Peter

    2000-01-01

    The objective of the study described in this paper is to enable estimation of wave overtopping rates for slopes/ramps given by a wide range of geometric parameters when subjected to varying wave conditions. To achieve this a great number of model tests are carried out in a wave tank using irregular...

  2. Evaluating the impact of a wide range of vegetation densities on river channel pattern

    Science.gov (United States)

    Pattison, Ian; Roucou, Ron

    2016-04-01

    develop a simple conceptual model to explain the observations along the wide range of vegetation densities investigated. At low plant densities, each plant acted independently and caused flow separation and convergence around each plant, similar to in the Coulthard (2005] experiment. At medium densities, individual plants start to interact together with narrow channels developing longitudinally between vegetative bars. Finally at very high densities, there was both lateral and longitudinal interaction between plants meaning that flow was diverted around them forming wandering, meandering channels. In summary, the relationship between vegetation density and channel braiding is more complex than previous thought, taking a parabolic shape, with maximum braiding occurring at medium vegetation densities.

  3. Novel methodology for wide-ranged multistage morphing waverider based on conical theory

    Science.gov (United States)

    Liu, Zhen; Liu, Jun; Ding, Feng; Xia, Zhixun

    2017-11-01

    This study proposes the wide-ranged multistage morphing waverider design method. The flow field structure and aerodynamic characteristics of multistage waveriders are also analyzed. In this method, the multistage waverider is generated in the same conical flowfield, which contains a free-stream surface and different compression-stream surfaces. The obtained results show that the introduction of the multistage waverider design method can solve the problem of aerodynamic performance deterioration in the off-design state and allow the vehicle to always maintain the optimal flight state. The multistage waverider design method, combined with transfiguration flight strategy, can lead to greater design flexibility and the optimization of hypersonic wide-ranged waverider vehicles.

  4. Why Output Only Modal Analysis is a Desirable Tool for a Wide Range of Practical Applications

    DEFF Research Database (Denmark)

    Brincker, Rune; Ventura, C.; Andersen, P.

    2003-01-01

    In this paper the basic principles in output modal testing and analysis are presented and discussed. A brief review of the techniques for output-only modal testing and identification is presented, and it is argued, that there is now a wide range of techniques for effective identification of modal...... parameters of practical interest - including the mode shape scaling factor - with a high degree of accuracy. It is also argued that the output-only technology offers the user a number of advantages over traditional modal testing. The output-only modal technology allows the user to perform a modal analysis...... in an easier way and in many cases more effectively than traditional modal analysis methods. It can be applied for modal testing and analysis on a wide range of structures and not only for problems generally investigated using traditional modal analysis, but also for those requiring load estimation, vibration...

  5. Wearable Wide-Range Strain Sensors Based on Ionic Liquids and Monitoring of Human Activities

    Directory of Open Access Journals (Sweden)

    Shao-Hui Zhang

    2017-11-01

    Full Text Available Wearable sensors for detection of human activities have encouraged the development of highly elastic sensors. In particular, to capture subtle and large-scale body motion, stretchable and wide-range strain sensors are highly desired, but still a challenge. Herein, a highly stretchable and transparent stain sensor based on ionic liquids and elastic polymer has been developed. The as-obtained sensor exhibits impressive stretchability with wide-range strain (from 0.1% to 400%, good bending properties and high sensitivity, whose gauge factor can reach 7.9. Importantly, the sensors show excellent biological compatibility and succeed in monitoring the diverse human activities ranging from the complex large-scale multidimensional motions to subtle signals, including wrist, finger and elbow joint bending, finger touch, breath, speech, swallow behavior and pulse wave.

  6. 10-decade wide-range neutron-monitoring system. Final test report

    Energy Technology Data Exchange (ETDEWEB)

    Green, W.K.

    1970-10-01

    The objective of Project Agreement 49 was to design, fabricate, test, and evaluate under actual nuclear reactor operating conditions, one prototype counting-Campbelling wide-range type thermal neutron flux measurement channel. This report describes the basic system designed for PA 49, and describes and presents the results of tests conducted on the system. Individual module descriptions and schematics are contained in the instruction manual which was issued with the system.

  7. A Single-Phase Boost Rectifier System for Wide Range of Load Variations

    OpenAIRE

    R Ghosh; Narayanan, G.

    2007-01-01

    Converters operated in discontinuous-conduction-mode (DCM)and in continuous-conduction-mode (CCM) are suitable for lighter and higher loads, respectively. A new, constant switching frequency based single-phase rectifier system is proposed, which operates in DCM and in CCM for outputs less than and greater than 50% rated load, respectively, covering a wide range of load variation. The power circuit and the control circuit of the proposed rectifier are easily configurable for DCM and CCM operat...

  8. The Brightest Gamma-Ray Flaring Blazar in the Sky: AGILE and Multi-wavelength Observations of 3C 454.3 During 2010 November

    Science.gov (United States)

    Vercellone, S.; Striani, E.; Vittorini, V.; Donnarumma, I.; Pacciani, L.; Pucella, G.; Tavani, M.; Raiteri, C. M.; Villata, M.; Romano, P.; Fiocchi, M.; Bazzano, A.; Bianchin, V.; Ferrigno, C.; Maraschi, L.; Pian, E.; Türler, M.; Ubertini, P.; Bulgarelli, A.; Chen, A. W.; Giuliani, A.; Longo, F.; Barbiellini, G.; Cardillo, M.; Cattaneo, P. W.; Del Monte, E.; Evangelista, Y.; Feroci, M.; Ferrari, A.; Fuschino, F.; Gianotti, F.; Giusti, M.; Lazzarotto, F.; Pellizzoni, A.; Piano, G.; Pilia, M.; Rapisarda, M.; Rappoldi, A.; Sabatini, S.; Soffitta, P.; Trifoglio, M.; Trois, A.; Giommi, P.; Lucarelli, F.; Pittori, C.; Santolamazza, P.; Verrecchia, F.; Agudo, I.; Aller, H. D.; Aller, M. F.; Arkharov, A. A.; Bach, U.; Berdyugin, A.; Borman, G. A.; Chigladze, R.; Efimov, Yu. S.; Efimova, N. V.; Gómez, J. L.; Gurwell, M. A.; McHardy, I. M.; Joshi, M.; Kimeridze, G. N.; Krajci, T.; Kurtanidze, O. M.; Kurtanidze, S. O.; Larionov, V. M.; Lindfors, E.; Molina, S. N.; Morozova, D. A.; Nazarov, S. V.; Nikolashvili, M. G.; Nilsson, K.; Pasanen, M.; Reinthal, R.; Ros, J. A.; Sadun, A. C.; Sakamoto, T.; Sallum, S.; Sergeev, S. G.; Schwartz, R. D.; Sigua, L. A.; Sillanpää, A.; Sokolovsky, K. V.; Strelnitski, V.; Takalo, L.; Taylor, B.; Walker, G.

    2011-08-01

    Since 2005, the blazar 3C 454.3 has shown remarkable flaring activity at all frequencies, and during the last four years it has exhibited more than one γ-ray flare per year, becoming the most active γ-ray blazar in the sky. We present for the first time the multi-wavelength AGILE, Swift, INTEGRAL, and GASP-WEBT data collected in order to explain the extraordinary γ-ray flare of 3C 454.3 which occurred in 2010 November. On 2010 November 20 (MJD 55520), 3C 454.3 reached a peak flux (E >100 MeV) of Fp γ = (6.8 ± 1.0) × 10-5 photons cm-2 s-1 on a timescale of about 12 hr, more than a factor of six higher than the flux of the brightest steady γ-ray source, the Vela pulsar, and more than a factor of three brighter than its previous super-flare on 2009 December 2-3. The multi-wavelength data make possible a thorough study of the present event: the comparison with the previous outbursts indicates a close similarity to the one that occurred in 2009. By comparing the broadband emission before, during, and after the γ-ray flare, we find that the radio, optical, and X-ray emission varies within a factor of 2-3, whereas the γ-ray flux by a factor of 10. This remarkable behavior is modeled by an external Compton component driven by a substantial local enhancement of soft seed photons.

  9. Airborne Multiwavelength High-Spectral-Resolution Lidar (HSRL-2) Observations During TCAP 2012: Vertical Proles of Optical and Microphysical Properties of a Smoke/Urban Haze Plume Over the Northeastern Coast of the US

    Energy Technology Data Exchange (ETDEWEB)

    Muller, Detlef; Hostetler, Chris A.; Ferrare, R. A.; Burton, S. P.; Chemyakin, Eduard; Kolgotin, A.; Hair, John; Cook, A. L.; Harper, David; Rogers, R. R.; Hare, Rich; Cleckner, Craig; Obland, Michael; Tomlinson, Jason M.; Berg, Larry K.; Schmid, Beat

    2014-10-10

    We present rst measurements with the rst airborne multiwavelength High-Spectral Resolution Lidar (HSRL-2), developed by NASA Langley Research Center. The instrument was operated during the Department of Energy (DOE) Two-Column Aerosol Project (TCAP) in July 2012. We observed out ow of urban haze and fresh biomass burning smoke from the East Coast of the US out over the West Atlantic Ocean. Lidar ratios at 355 and 532 nm were ... sr indicating moderately absorbing aerosols. Extinctionrelated Angstrom exponents were 1.5{2 pointing at comparably small particles. Our novel automated, unsupervised data inversion algorithm retrieves particle e*ective radii of approximately 0.2 *m, which is in agreement with the large Angstrom exponents. We nd reasonable agreement to particle size parameters obtained from situ measurements carried out with the DOE G-1 aircraft that ew during the lidar observations.

  10. Resource selection and its implications for wide-ranging mammals of the brazilian cerrado.

    Directory of Open Access Journals (Sweden)

    Carly Vynne

    Full Text Available Conserving animals beyond protected areas is critical because even the largest reserves may be too small to maintain viable populations for many wide-ranging species. Identification of landscape features that will promote persistence of a diverse array of species is a high priority, particularly, for protected areas that reside in regions of otherwise extensive habitat loss. This is the case for Emas National Park, a small but important protected area located in the Brazilian Cerrado, the world's most biologically diverse savanna. Emas Park is a large-mammal global conservation priority area but is too small to protect wide-ranging mammals for the long-term and conserving these populations will depend on the landscape surrounding the park. We employed novel, noninvasive methods to determine the relative importance of resources found within the park, as well as identify landscape features that promote persistence of wide-ranging mammals outside reserve borders. We used scat detection dogs to survey for five large mammals of conservation concern: giant armadillo (Priodontes maximus, giant anteater (Myrmecophaga tridactyla, maned wolf (Chrysocyon brachyurus, jaguar (Panthera onca, and puma (Puma concolor. We estimated resource selection probability functions for each species from 1,572 scat locations and 434 giant armadillo burrow locations. Results indicate that giant armadillos and jaguars are highly selective of natural habitats, which makes both species sensitive to landscape change from agricultural development. Due to the high amount of such development outside of the Emas Park boundary, the park provides rare resource conditions that are particularly important for these two species. We also reveal that both woodland and forest vegetation remnants enable use of the agricultural landscape as a whole for maned wolves, pumas, and giant anteaters. We identify those features and their landscape compositions that should be prioritized for

  11. Resource selection and its implications for wide-ranging mammals of the brazilian cerrado.

    Science.gov (United States)

    Vynne, Carly; Keim, Jonah L; Machado, Ricardo B; Marinho-Filho, Jader; Silveira, Leandro; Groom, Martha J; Wasser, Samuel K

    2011-01-01

    Conserving animals beyond protected areas is critical because even the largest reserves may be too small to maintain viable populations for many wide-ranging species. Identification of landscape features that will promote persistence of a diverse array of species is a high priority, particularly, for protected areas that reside in regions of otherwise extensive habitat loss. This is the case for Emas National Park, a small but important protected area located in the Brazilian Cerrado, the world's most biologically diverse savanna. Emas Park is a large-mammal global conservation priority area but is too small to protect wide-ranging mammals for the long-term and conserving these populations will depend on the landscape surrounding the park. We employed novel, noninvasive methods to determine the relative importance of resources found within the park, as well as identify landscape features that promote persistence of wide-ranging mammals outside reserve borders. We used scat detection dogs to survey for five large mammals of conservation concern: giant armadillo (Priodontes maximus), giant anteater (Myrmecophaga tridactyla), maned wolf (Chrysocyon brachyurus), jaguar (Panthera onca), and puma (Puma concolor). We estimated resource selection probability functions for each species from 1,572 scat locations and 434 giant armadillo burrow locations. Results indicate that giant armadillos and jaguars are highly selective of natural habitats, which makes both species sensitive to landscape change from agricultural development. Due to the high amount of such development outside of the Emas Park boundary, the park provides rare resource conditions that are particularly important for these two species. We also reveal that both woodland and forest vegetation remnants enable use of the agricultural landscape as a whole for maned wolves, pumas, and giant anteaters. We identify those features and their landscape compositions that should be prioritized for conservation, arguing

  12. Impedance Based Analysis and Design of Harmonic Resonant Controller for a Wide Range of Grid Impedance

    DEFF Research Database (Denmark)

    Kwon, Jun Bum; Wang, Xiongfei; Blaabjerg, Frede

    2014-01-01

    This paper investigates the effect of grid impedance variation on harmonic resonant current controllers for gridconnected voltage source converters by means of impedance-based analysis. It reveals that the negative harmonic resistances tend to be derived from harmonic resonant controllers...... in the closed-loop output admittance of converter. Such negative resistances may interact with the grid impedance resulting in steady state error or unstable harmonic compensation. To deal with this problem, a design guideline for harmonic resonant controllers under a wide range of grid impedance is proposed...

  13. Why Output Only Modal Analysis is a Desirable Tool for a Wide Range of Practical Applications

    OpenAIRE

    Brincker, Rune; Ventura, C.; Andersen, P.

    2003-01-01

    In this paper the basic principles in output modal testing and analysis are presented and discussed. A brief review of the techniques for output-only modal testing and identification is presented, and it is argued, that there is now a wide range of techniques for effective identification of modal parameters of practical interest - including the mode shape scaling factor - with a high degree of accuracy. It is also argued that the output-only technology offers the user a number of advantages o...

  14. Lithium-ion battery dynamic model for wide range of operating conditions

    DEFF Research Database (Denmark)

    Stroe, Ana-Irina; Stroe, Daniel-Ioan; Swierczynski, Maciej Jozef

    2017-01-01

    In order to analyze the dynamic behavior of a Lithium-ion (Li-ion) battery and to determine their suitability for various applications, battery models are needed. An equivalent electrical circuit model is the most common way of representing the behavior of a Li-ion battery. There are different...... characterization tests performed for a wide range of operating conditions (temperature, load current and state-of-charge) on a commercial available 13Ah high-power lithium titanate oxide battery cell. The obtained results were used to parametrize the proposed dynamic model of the battery cell. To assess...

  15. Development of wide-range constitutive equations for calculations of high-rate deformation of metals

    Directory of Open Access Journals (Sweden)

    Preston D.

    2011-01-01

    Full Text Available For development of models of strength and compressibility of metals in wide range of pressures (up to several megabar and strain rates ~ 1÷108 s−1, the method of dynamic tests is used. Since direct measurement of strength is impossible under complicated intensive high-rate loading, a formal model is created at first, and then it is updated basing on comparison with many experiments, which are sensitive to shear strength. Elastic-plastic, viscous-elastic-plastic and relaxation integral models became nowadays most commonly used. The basic unsolved problems in simulation of high-rate deformation of metals are mentioned in the paper.

  16. A parameterization of momentum roughness length and displacement height for a wide range of canopy densities

    Directory of Open Access Journals (Sweden)

    A. Verhoef

    1997-01-01

    occurring in the d-data across 16 selected canopies can be explained, whereas the analogous value for the z0-data (24 datapoints available is 81%. This makes the R94 model, with only two coefficients and its relatively simple equations, a useful universal tool for predicting z0 and d values for all kinds of canopies. For comparison, a similar fitting exercise is made using simple linear equations based on obstacle height only (e.g. Brutsaert, 1982 and another formula involving canopy height as well as roughness density (Lettau, 1969. The fitted Brutsaert equations explain 98% and 62% of the variance in the d and z0-data, respectively. Lettau's equation for prediction of z0 performs unsatisfactorily (r2 values <0, even after fitting of the coefficient and so it is concluded that the drag partition model is definitely the most effective for prediction of the momentum roughness lengths for a wide rang of canopy densities.

  17. Bobcats ( Lynx rufus) as a Model Organism to Investigate the Effects of Roads on Wide-Ranging Carnivores

    Science.gov (United States)

    Litvaitis, John A.; Reed, Gregory C.; Carroll, Rory P.; Litvaitis, Marian K.; Tash, Jeffrey; Mahard, Tyler; Broman, Derek J. A.; Callahan, Catherine; Ellingwood, Mark

    2015-06-01

    We are using bobcats ( Lynx rufus) as a model organism to examine how roads affect the abundance, distribution, and genetic structure of a wide-ranging carnivore. First, we compared the distribution of bobcat-vehicle collisions to road density and then estimated collision probabilities for specific landscapes using a moving window with road-specific traffic volume. Next, we obtained incidental observations of bobcats from the public, camera-trap detections, and locations of bobcats equipped with GPS collars to examine habitat selection. These data were used to generate a cost-surface map to investigate potential barrier effects of roads. Finally, we have begun an examination of genetic structure of bobcat populations in relation to major road networks. Distribution of vehicle-killed bobcats was correlated with road density, especially state and interstate highways. Collision models suggested that some regions may function as demographic sinks. Simulated movements in the context of the cost-surface map indicated that some major roads may be barriers. These patterns were supported by the genetic structure of bobcats. The sharpest divisions among genetically distinct demes occurred along natural barriers (mountains and large lakes) and in road-dense regions. In conclusion, our study has demonstrated the utility of using bobcats as a model organism to understand the variety of threats that roads pose to a wide-ranging species. Bobcats may also be useful as one of a group of focal species while developing approaches to maintain existing connectivity or mitigate the negative effects of roads.

  18. Evaluation of canola chlorophyll index and leaf nitrogen under wide range of soil moisture

    Science.gov (United States)

    Meskini-Vishkaee, Fatemeh; Mohammadi, Mohammad Hosein; Neyshabouri, Mohammad Reza; Shekari, Farid

    2015-01-01

    The paper presents a study on the effect of soil matric suction on the variation of leaf chlorophyll index and nitrogen concentration of canola. Results showed that chlorophyll index increases exponentially with soil matric suction, especially at the late season of canola growing time. At moderate matric suction (200 and 300 kPa soil suction heads), chlorophyll index remains nearly constant, but in drier soil (matric suction >300 kPa), chlorophyll index increases gradually with time. Despite the variation of the total leaf nitrogen with the soil matric suction, it is similar to the variation of the chlorophyll index, but the results showed that the chlorophyll index - nitrogen concentration curve has a demarcated bi-modal shape. We suggest that 2.7% of nitrogen and 69.8 of the chlorophyll index value represent the upper limit of the chlorophyll meter reliability for estimation of canola nitrogen under a wide range of soil moisture levels. These results confirm that the chlorophyll meter can be used as an effective tool for rapid and non-destructive estimation of the relative chlorophyll and nitrogen content in canola leaves at a wide range of soil moisture content, except for nearly wilting coefficient or extremely high drought stress

  19. Wide-Range Adaptive RF-to-DC Power Converter for UHF RFIDs

    KAUST Repository

    Ouda, Mahmoud H.

    2016-07-27

    A wide-range, differential, cross-coupled rectifier is proposed with an extended dynamic range of input RF power that enables wireless powering from varying distances. The proposed architecture mitigates the reverse-leakage problem in conven- tional, cross-coupled rectifiers without degrading sensitivity. A prototype is designed for UHF RFID applications, and is imple- mented using 0.18 μ m CMOS technology. On-chip measurements demonstrate a sensitivity of − 18 dBm for 1 V output over a 100 k Ω load and a peak RF-to-DC power conversion efficiency of 65%. A conventional, fully cross-coupled rectifier is fabricated along- side for comparison and the proposed rectifier shows more than 2 × increase in dynamic range and a 25% boosting in output voltage than the conventional rectifier

  20. Wide Range Vacuum Pumps for the SAM Instrument on the MSL Curiosity Rover

    Science.gov (United States)

    Sorensen, Paul; Kline-Schoder, Robert; Farley, Rodger

    2014-01-01

    Creare Incorporated and NASA Goddard Space Flight Center developed and space qualified two wide range pumps (WRPs) that were included in the Sample Analysis at Mars (SAM) instrument. This instrument was subsequently integrated into the Mars Science Laboratory (MSL) "Curiosity Rover," launched aboard an Atlas V rocket in 2011, and landed on August 6, 2012, in the Gale Crater on Mars. The pumps have now operated for more than 18 months in the Gale Crater and have been evacuating the key components of the SAM instrument: a quadrupole mass spectrometer, a tunable laser spectrometer, and six gas chromatograph columns. In this paper, we describe the main design challenges and the ways in which they were solved. This includes the custom design of a miniaturized, high-speed motor to drive the turbo drag pump rotor, analysis of rotor dynamics for super critical operation, and bearing/lubricant design/selection.

  1. Water Vapor Sorption Properties of Polyethylene Terephthalate over a Wide Range of Humidity and Temperature.

    Science.gov (United States)

    Dubelley, Florence; Planes, Emilie; Bas, Corine; Pons, Emmanuelle; Yrieix, Bernard; Flandin, Lionel

    2017-03-02

    The dynamic and equilibrium water vapor sorption properties of amorphous polyethylene terephthalate were determined via gravimetric analysis over a wide range of temperatures (23-70 °C) and humidities (0-90% RH). At low temperature and relative humidity, the dynamics of the sorption process was Fickian. Increasing the temperature or relative humidity induced a distinct up-swing effect, which was associated with a plasticization/clustering phenomenon. For high temperatures and relative humidity, a densification of the polymer was evidenced. In addition to the classical Fickian diffusion, a new parameter was introduced to express the structural modifications of PET. Finally, two partial pressures were defined as thresholds that control the transition between these three phases. A simplified state diagram was finally proposed. In addition, the thermal dependence of these sorption modes was also determined and reported. The enthalpy of Henry's water sorption and the activation energy of diffusion were independent of vapor pressure and followed an Arrhenius law.

  2. Interaction factors for two elliptical embedded cracks with a wide range of aspect ratios

    Directory of Open Access Journals (Sweden)

    Kisaburo Azuma

    2017-02-01

    Full Text Available The value of stress intensity factor may be increased through the interaction of multiple cracks that are in close proximity to one another. We investigated the interaction factors of two equal elliptical cracks with a wide range of aspect ratios. Finite element analysis for a linear elastic solid was used to obtain the interaction factor for embedded cracks in an infinite model subjected to remote tension loading. Relationships between interaction factors and dimensionless distances between the cracks were discussed. The results demonstrated that the interaction factors depend on the crack aspect ratio, whose effect is related to the dimensionless distance. Thus, it is suggested that interaction factors can be reasonably characterized using different dimensionless distances depending on the aspect ratio. Finally, we provide a simple empirical formula for obtaining the interaction factors for embedded cracks.

  3. The Ionization Constant of Water over Wide Ranges of Temperature and Density

    Science.gov (United States)

    Bandura, Andrei V.; Lvov, Serguei N.

    2006-03-01

    A semitheoretical approach for the ionization constant of water, KW, is used to fit the available experimental data over wide ranges of density and temperature. Statistical thermodynamics is employed to formulate a number of contributions to the standard state chemical potential of the ionic hydration process. A sorption model is developed for calculating the inner-shell term, which accounts for the ion-water interactions in the immediate ion vicinity. A new analytical expression is derived using the Bragg-Williams approximation that reproduces the dependence of a mean ion solvation number on the solvent chemical potential. The proposed model was found to be correct at the zero-density limit. The final formulation has a simple analytical form, includes seven adjustable parameters, and provides good fitting of the collected KW data, within experimental uncertainties, for a temperature range of 0-800 °C and densities of 0-1.2 g cm-3.

  4. Electrochemical reduction of oxygen catalyzed by a wide range of bacteria including Gram-positive

    Energy Technology Data Exchange (ETDEWEB)

    Cournet, Amandine [Universite de Toulouse, UPS, LU49, Adhesion Bacterienne et Formation de Biofilms, 35 chemin des Maraichers, 31 062 Toulouse cedex 09 (France); Laboratoire de Genie Chimique CNRS, Universite de Toulouse, 4 allee Emile Monso, BP 84234, 31432 Toulouse cedex 04 (France); Delia, Marie-Line; Bergel, Alain [Laboratoire de Genie Chimique CNRS, Universite de Toulouse, 4 allee Emile Monso, BP 84234, 31432 Toulouse cedex 04 (France); Roques, Christine; Berge, Mathieu [Universite de Toulouse, UPS, LU49, Adhesion Bacterienne et Formation de Biofilms, 35 chemin des Maraichers, 31 062 Toulouse cedex 09 (France)

    2010-04-15

    Most bacteria known to be electrochemically active have been harvested in the anodic compartments of microbial fuel cells (MFCs) and are able to use electrodes as electron acceptors. The reverse phenomenon, i.e. using solid electrodes as electron donors, is not so widely studied. To our knowledge, most of the electrochemically active bacteria are Gram-negative. The present study implements a transitory electrochemical technique (cyclic voltammetry) to study the microbial catalysis of the electrochemical reduction of oxygen. It is demonstrated that a wide range of aerobic and facultative anaerobic bacteria are able to catalyze oxygen reduction. Among these electroactive bacteria, several were Gram-positive. The transfer of electrons was direct since no activity was obtained with the filtrate. These findings, showing a widespread property among bacteria including Gram-positive ones, open new and interesting routes in the field of electroactive bacteria research. (author)

  5. A micromixer with consistent mixing performance for a wide range of flow rates.

    Science.gov (United States)

    Goovaerts, Robert; Van Assche, Tom; Sonck, Marc; Denayer, Joeri; Desmet, Gert

    2015-02-01

    A micromixer with consistent mixing performance for a wide range of flow rates is presented. The mixer makes use of internally moving elements, i.e. steel balls that are located in dedicated mixing chambers. Movement is induced by a rotating magnetic field. To get better insight in differences between active and passive mixing, we studied a mixer that can operate in both regimes. A mixing performance study for a range of flow rates along with pressure drop data is presented. The response of the moving elements in regard to the magnetic field is shown experimentally and shows the limitations of earlier modeling studies. Lastly, the estimated power input on the fluids was calculated and allows for a comparison with more well-known convective-type mixers. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Experimental Investigation of Zinc Antimonide Thin Film Thermoelectric Element over Wide Range of Operating Conditions

    DEFF Research Database (Denmark)

    Mirhosseini, Mojtaba; Rezania, Alireza; Blichfeld, Anders B.

    2017-01-01

    different resistive loads and over a wide range of operating temperatures from 160 °C to 350 °C. The results show that, at a hot side temperature equal to 275 °C, the Seebeck coefficient (α) reaches its maximum value (242 μV/K), which is comparable to that of bulk materials reported in the literature....... According to a variation of the load resistance, the maximum power output, that is a function of temperature, occurs at 170.25 Ω. The maximum power is 8.46 μW corresponding to a cold and hot side temperature of ≈ 30 °C and 350 °C, respectively....

  7. A computer code simulating multistage chemical exchange column under wide range of operating conditions

    Energy Technology Data Exchange (ETDEWEB)

    Yamanishi, Toshihiko; Okuno, Kenji [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment

    1996-09-01

    A computer code has been developed to simulate a multistage CECE(Combined Electrolysis Chemical Exchange) column. The solution of basic equations can be found out by the Newton-Raphson method. The independent variables are the atom fractions of D and T in each stage for the case where H is dominant within the column. These variables are replaced by those of H and T under the condition that D is dominant. Some effective techniques have also been developed to get a set of solutions of the basic equations: a setting procedure of initial values of the independent variables; and a procedure for the convergence of the Newton-Raphson method. The computer code allows us to simulate the column behavior under a wide range of the operating conditions. Even for a severe case, where the dominant species changes along the column height, the code can give a set of solutions of the basic equations. (author)

  8. A wide range and highly sensitive optical fiber pH sensor using polyacrylamide hydrogel

    Science.gov (United States)

    Pathak, Akhilesh Kumar; Singh, Vinod Kumar

    2017-12-01

    In the present study we report the fabrication and characterization of no-core fiber sensor (NCFS) using smart hydrogel coating for pH measurement. The no-core fiber (NCF) is stubbed between two single-mode fibers with SMA connector before immobilizing of smart hydrogel. The wavelength interrogation technique is used to calculate the sensitivity of the proposed sensor. The result shows a high sensitivity of 1.94 nm/pH for a wide range of pH values varied from 3 to 10 with a good linear response. In addition to high sensitivity, the fabricated sensor provides a fast response time with a good stability, repeatability and reproducibility.

  9. Autonomous Vehicles Have a Wide Range of Possible Energy Impacts (Poster)

    Energy Technology Data Exchange (ETDEWEB)

    Brown, A.; Repac, B.; Gonder, J.

    2013-07-01

    This poster presents initial estimates of the net energy impacts of automated vehicles (AVs). Automated vehicle technologies are increasingly recognized as having potential to decrease carbon dioxide emissions and petroleum consumption through mechanisms such as improved efficiency, better routing, lower traffic congestion, and by enabling advanced technologies. However, some effects of AVs could conceivably increase fuel consumption through possible effects such as longer distances traveled, increased use of transportation by underserved groups, and increased travel speeds. The net effect on petroleum use and climate change is still uncertain. To make an aggregate system estimate, we first collect best estimates for the energy impacts of approximately ten effects of AVs. We then use a modified Kaya Identity approach to estimate the range of aggregate effects and avoid double counting. We find that depending on numerous factors, there is a wide range of potential energy impacts. Adoption of automated personal or shared vehicles can lead to significant fuel savings but has potential for backfire.

  10. Mechanical and Microstructural Investigation of Dual Phase Stainless Steel (LDX2101) under a wide range of strain rates

    Science.gov (United States)

    Ameri, Ali; Escobedo-Diaz, Juan; Ashraf, Mahmud; Brown, Andrew; Hazell, Paul; Hutchison, Wayne; Quadir, Zakaria

    2017-06-01

    The mechanical response and the microstructural evolution of lean duplex stainless steel 2101 (LDSS 2101) under a wide range of strain rates has been investigated. Experimental testing spanned from quasistatic, high strain-rate (Split Hopkinson Pressure Bar) and shock loading. The microstructural changes, e.g. phase transformation and grain rotation, texture and substructure evolution, were investigated by optical microscopy, X-ray diffraction (XRD) and electron-backscattered diffraction (EBSD). A significant increase in the yield stress with increasing strain rate was observed. The plastic deformation, e.g. work hardening rate, was also depended on the strain-rate. The threshold stress for the iron-epsilon phase transformation was obtained from free surface velocity measurements and the retained high pressure phase was assessed by XRD measurements.

  11. Conduction of Complex Elements of Vacuum Systems in a Wide Range of Pressures

    Directory of Open Access Journals (Sweden)

    O. A. Shemarova

    2014-01-01

    Full Text Available The article presents a statistical mathematical model of a rarefied gas flow based on the method of particles in cells. This approach enables to define basic parameters of gas flow and vacuum systems in a wide range of pressures, including such an important parameter as conductivity of the vacuum system.Key assumptions in designing a mathematical model are: describing the collision of the molecules as hard spheres of elastic collision; considering the collisions to be paired and instant; the molecules velocity distribution corresponding to the Maxwell distribution. The essential feature is simulation of waiting time for the next collision. It depends on the state of the entire system of particles and is independent of what pair is involved in collision.The paper presents a detailed algorithm for implementation of a mathematical model to calculate conductivity. It includes three main stages. The first stage simulates only collisions of particles within the fixed cell of grid. The second stage simulates displacement of particles in accordance with their speed and time step, as well as interaction with the internal surfaces of the vacuum system. The final stage determines system conductivity.As an example, numerical experiments were conducted to determine conductivity of the long cylindrical channel in a wide range of pressures and conductivity of chevron screens too. Obtained data are compared with experimental data, and an error is evaluated. In molecular and transient conditions of gas flow the method of particles in cells gives high accuracy. In the viscous conditions the accuracy decreases because of originating region of continuous medium.This model can be used not only to determine conductivity of vacuum systems, but also to calculate gas flow parameters in systems with large flows (no restrictions for the flow rate value for the channels and profiles with geometry of any complexity. An important feature is that it allows taking into account

  12. Theoretical and Experimental Study on Wide Range Optical Fiber Turbine Flow Sensor

    Directory of Open Access Journals (Sweden)

    Yuhuan Du

    2016-07-01

    Full Text Available In this paper, a novel fiber turbine flow sensor was proposed and demonstrated for liquid measurement with optical fiber, using light intensity modulation to measure the turbine rotational speed for converting to flow rate. The double-circle-coaxial (DCC fiber probe was introduced in frequency measurement for the first time. Through the divided ratio of two rings light intensity, the interference in light signals acquisition can be eliminated. To predict the characteristics between the output frequency and flow in the nonlinear range, the turbine flow sensor model was built. Via analyzing the characteristics of turbine flow sensor, piecewise linear equations were achieved in expanding the flow measurement range. Furthermore, the experimental verification was tested. The results showed that the flow range ratio of DN20 turbine flow sensor was improved 2.9 times after using piecewise linear in the nonlinear range. Therefore, combining the DCC fiber sensor and piecewise linear method, it can be developed into a strong anti-electromagnetic interference(anti-EMI and wide range fiber turbine flowmeter.

  13. Experimental evaluation of a miniature MR device for a wide range of human perceivable haptic sensations

    Science.gov (United States)

    Yang, Tae-Heon; Koo, Jeong-Hoi

    2017-12-01

    Humans can experience a realistic and vivid haptic sensations by the sense of touch. In order to have a fully immersive haptic experience, both kinaesthetic and vibrotactile information must be presented to human users. Currently, little haptic research has been performed on small haptic actuators that can covey both vibrotactile feedback based on the frequency of vibrations up to the human-perceivable limit and multiple levels of kinaesthetic feedback rapidly. Therefore, this study intends to design a miniature haptic device based on MR fluid and experimentally evaluate its ability to convey vibrotactile feedback up to 300 Hz along with kinaesthetic feedback. After constructing a prototype device, a series of testing was performed to evaluate its performance of the prototype using an experimental setup, consisting of a precision dynamic mechanical analyzer and an accelerometer. The kinaesthetic testing results show that the prototype device can provide the force rate up to 89% at 5 V (360 mA), which can be discretized into multiple levels of ‘just noticeable difference’ force rate, indicating that the device can convey a wide range of kinaesthetic sensations. To evaluate the high frequency vibrotactile feedback performance of the device, its acceleration responses were measured and processed using the FFT analysis. The results indicate that the device can convey high frequency vibrotactile sensations up to 300 Hz with the sufficiently large intensity of accelerations that human can feel.

  14. Alternative chitosan-based EPR dosimeter applicable for a relatively wide range of gamma radiation doses

    Science.gov (United States)

    Piroonpan, Thananchai; Katemake, Pichayada; Panritdam, Eagkapong; Pasanphan, Wanvimol

    2017-12-01

    Chitosan biopolymer is proposed as an alternative EPR dosimeter. Its ability to be EPR dosimeter was studied in comparison with the conventional alanine, sugars (i.e., glucose and sucrose), formate derivatives (i.e., lithium (Li), magnesium (Mg), and calcium (Ca) formate). Ethylene vinyl acetate (EVA) and paraffin were used as binder for the preparation of composite EPR dosimeter. Dose responses of all materials were investigated in a wide dose range of radiation doses, i.e., low-level (0-1 kGy), medium-level (1-10 kGy) and high-level (10-100 kGy). The EPR dosimeter properties were studied under different parameters, i.e., microwave power, materials contents, absorbed doses, storage conditions and post-irradiation effects. Li-formate showed a simple EPR spectrum and exhibited superior radiation response for low-dose range; whereas chitosan and sucrose exhibited linear dose response in all studied dose ranges. The EPR signals of chitosan exhibited similar stability as glucose, Li-formate and alanine at ambient temperature after irradiation as long as a year. All EPR signals of the studied materials were affected post-irradiation temperature and humidity after gamma irradiation. The EPR signal of chitosan exhibited long-term stability and it was not sensitive to high storage temperatures and humidity values after irradiation. Chitosan has a good merit as the alternative bio-based material for a stable EPR dosimeter in a wide range of radiation-absorbed doses.

  15. Screening variability and change of soil moisture under wide-ranging climate conditions: Snow dynamics effects.

    Science.gov (United States)

    Verrot, Lucile; Destouni, Georgia

    2015-01-01

    Soil moisture influences and is influenced by water, climate, and ecosystem conditions, affecting associated ecosystem services in the landscape. This paper couples snow storage-melting dynamics with an analytical modeling approach to screening basin-scale, long-term soil moisture variability and change in a changing climate. This coupling enables assessment of both spatial differences and temporal changes across a wide range of hydro-climatic conditions. Model application is exemplified for two major Swedish hydrological basins, Norrström and Piteälven. These are located along a steep temperature gradient and have experienced different hydro-climatic changes over the time period of study, 1950-2009. Spatially, average intra-annual variability of soil moisture differs considerably between the basins due to their temperature-related differences in snow dynamics. With regard to temporal change, the long-term average state and intra-annual variability of soil moisture have not changed much, while inter-annual variability has changed considerably in response to hydro-climatic changes experienced so far in each basin.

  16. Wide-Range Temperature Sensors with High-Level Pulse Train Output

    Science.gov (United States)

    Hammoud, Ahmad; Patterson, Richard L.

    2009-01-01

    Two types of temperature sensors have been developed for wide-range temperature applications. The two sensors measure temperature in the range of -190 to +200 C and utilize a thin-film platinum RTD (resistance temperature detector) as the temperature-sensing element. Other parts used in the fabrication of these sensors include NPO (negative-positive- zero) type ceramic capacitors for timing, thermally-stable film or wirewound resistors, and high-temperature circuit boards and solder. The first type of temperature sensor is a relaxation oscillator circuit using an SOI (silicon-on-insulator) operational amplifier as a comparator. The output is a pulse train with a period that is roughly proportional to the temperature being measured. The voltage level of the pulse train is high-level, for example 10 V. The high-level output makes the sensor less sensitive to noise or electromagnetic interference. The output can be read by a frequency or period meter and then converted into a temperature reading. The second type of temperature sensor is made up of various types of multivibrator circuits using an SOI type 555 timer and the passive components mentioned above. Three configurations have been developed that were based on the technique of charging and discharging a capacitor through a resistive element to create a train of pulses governed by the capacitor-resistor time constant. Both types of sensors, which operated successfully over the wide temperature range, have potential use in extreme temperature environments including jet engines and space exploration missions.

  17. High-resolution and wide range displacement measurement based on planar grating

    Science.gov (United States)

    Lin, Jie; Guan, Jian; Wen, Feng; Tan, Jiubin

    2017-12-01

    High/ultra-precision motion measurements for precision translation stages are highly desired in modern manufacturing systems and instruments. In this work, we introduce a wide range three-axis grating encoder with nanometric resolution, which can measure the x-, y- and z-axial translational motions of a stage simultaneously. The grating encoder is composed of a reflective-type planar scale grating with a period of 8 μm and an optical reading head. A planar reference grating, which is the same as the planar scale grating except the length and width, is employed in the optical reading head. The x- and y- directional ±1st order diffractive beams of the planar scale grating interfere with the corresponding diffractive beams of the planar reference grating, forming the measurement signals. The x- and y- directional ±1st order diffractive beams of the two planar gratings propagate against their original incident path, working as the autocollimatic diffractive beams. Therefore, the z-axial measurement range of the proposed grating encoder is greatly enhanced. The x- and y- axial measurement ranges depend on the size of the planar scale grating. To make the grating encoder more compact, a double grating beam-splitting (DGBS) unit and two diffractive optical elements (DOEs) are introduced. The experimental results indicate that the z-axial displacement resolution is as high as 4 nm with an electronic data division card of 80 segments developed by our lab.

  18. Improvement of cyclic operation on pulverized coal fired boilers by applying wide range burners

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Toshihiko; Watanabe, Shinji; Kiga, Takashi; Koyata, Kazuo

    1999-07-01

    There are recently urgent requirements to operate pulverized coal fired power plants as well as oil fired units cyclically or at low loads. In order to cope with this, wide range burners (WRB) were jointly developed to obtain a high turndown operation by the Central Research Institute of Electric Power Industry (CRIEPI) and Ishikawajima-Harima Heavy Industries Co., Ltd. (IHI). In accordance with the results of various fundamental researches, including combustion tests with a tunnel furnace of 12 MW[thermal], it was confirmed the stability of the flame and the combustion characteristics at low loads as well as that of ordinary burners. The WRB have been applied to the new actual boilers that are Saijo Power Station NO. 2 unit of Sikoku Electric Power Co., Inc., Nanao-Ota Power Station NO. 2 unit of Hokuriku Electric Power Co., Inc. and Miike Power Station NO. 1 unit of Miike Thermal Power Co., Ltd.. The results of the trial operation have shown that the minimum burner load was below half of that of conventional burners, and accordingly the pulverized coal firing minimum load could be reduced. This paper explains about the cyclic operation of their boilers and the improvement effect by applying WRBs.

  19. Accurate Measurements of Aerosol Hygroscopic Growth over a Wide Range in Relative Humidity.

    Science.gov (United States)

    Rovelli, Grazia; Miles, Rachael E H; Reid, Jonathan P; Clegg, Simon L

    2016-06-30

    Using a comparative evaporation kinetics approach, we describe a new and accurate method for determining the equilibrium hygroscopic growth of aerosol droplets. The time-evolving size of an aqueous droplet, as it evaporates to a steady size and composition that is in equilibrium with the gas phase relative humidity, is used to determine the time-dependent mass flux of water, yielding information on the vapor pressure of water above the droplet surface at every instant in time. Accurate characterization of the gas phase relative humidity is provided from a control measurement of the evaporation profile of a droplet of know equilibrium properties, either a pure water droplet or a sodium chloride droplet. In combination, and by comparison with simulations that account for both the heat and mass transport governing the droplet evaporation kinetics, these measurements allow accurate retrieval of the equilibrium properties of the solution droplet (i.e., the variations with water activity in the mass fraction of solute, diameter growth factor, osmotic coefficient or number of water molecules per solute molecule). Hygroscopicity measurements can be made over a wide range in water activity (from >0.99 to, in principle, 0.9 and ∼±1% below 80% RH, and maximum uncertainties in diameter growth factor of ±0.7%. For all of the inorganic systems examined, the time-dependent data are consistent with large values of the mass accommodation (or evaporation) coefficient (>0.1).

  20. A “twisted” microfluidic mixer suitable for a wide range of flow rate applications

    KAUST Repository

    Sivashankar, Shilpa

    2016-06-27

    This paper proposes a new “twisted” 3D microfluidic mixer fabricated by a laser writing/microfabrication technique. Effective and efficient mixing using the twisted micromixers can be obtained by combining two general chaotic mixing mechanisms: splitting/recombining and chaotic advection. The lamination of mixer units provides the splitting and recombination mechanism when the quadrant of circles is arranged in a two-layered serial arrangement of mixing units. The overall 3D path of the microchannel introduces the advection. An experimental investigation using chemical solutions revealed that these novel 3D passive microfluidic mixers were stable and could be operated at a wide range of flow rates. This micromixer finds application in the manipulation of tiny volumes of liquids that are crucial in diagnostics. The mixing performance was evaluated by dye visualization, and using a pH test that determined the chemical reaction of the solutions. A comparison of the tornado-mixer with this twisted micromixer was made to evaluate the efficiency of mixing. The efficiency of mixing was calculated within the channel by acquiring intensities using ImageJ software. Results suggested that efficient mixing can be obtained when more than 3 units were consecutively placed. The geometry of the device, which has a length of 30 mm, enables the device to be integrated with micro total analysis systems and other lab-on-chip devices.

  1. Localization of a Wide-Ranging Panel of Antigens in the Rat Retina by Immunohistochemistry

    Science.gov (United States)

    Chidlow, Glyn; Daymon, Mark; Wood, John P. M.; Casson, Robert J.

    2011-01-01

    The preferred fixative for whole eyes is Davidson’s solution, which provides optimal tissue preservation while avoiding retinal detachment. Hitherto, the compatibility of Davidson’s solution with immunohistochemistry has been largely untested. The goal of the present study was to compare the immunolabeling patterns of a wide-ranging panel of commercially available, previously validated antibodies in formalin- and Davidson’s-fixed retinas. Immunohistochemistry was performed in normal pigmented rat eyes and, to facilitate localization of inducible proteins, eyes injected with the bacterial toxin lipopolysaccharide or subjected to laser-induced photoreceptor damage. Specificity of labeling was judged by the morphology and distribution of immunopositive cells, by the absence of signal in appropriate controls, and by comparison with expected staining patterns. Retinas fixed in formalin displayed only adequate morphological integrity but were highly compatible with all 39 antibodies evaluated. Retinas fixed in Davidson’s solution displayed morphological integrity superior to those fixed in formalin. Generally, the cellular and subcellular patterns and intensities of immunoreactivities obtained with each fixative were identical; however, Davidson’s fixative was less compatible with certain antibodies, such as the neurotransmitter γ-aminobutyric acid, the microglial marker iba1, the macroglial stress protein nestin, and the small heat shock proteins Hsp27 and αB-crystallin, shortfalls that somewhat temper enthusiasm concerning its use. PMID:21832149

  2. ATMOSPHERIC DYNAMICS OF TERRESTRIAL EXOPLANETS OVER A WIDE RANGE OF ORBITAL AND ATMOSPHERIC PARAMETERS

    Energy Technology Data Exchange (ETDEWEB)

    Kaspi, Yohai [Department of Earth and Planetary Sciences, Weizmann Institute of Science, 234 Herzl st., 76100, Rehovot (Israel); Showman, Adam P., E-mail: yohai.kaspi@weizmann.ac.il [Department of Planetary Sciences and Lunar and Planetary Laboratory, The University of Arizona, 1629 University Blvd., Tucson, AZ 85721 (United States)

    2015-05-01

    The recent discoveries of terrestrial exoplanets and super-Earths extending over a broad range of orbital and physical parameters suggest that these planets will span a wide range of climatic regimes. Characterization of the atmospheres of warm super-Earths has already begun and will be extended to smaller and more distant planets over the coming decade. The habitability of these worlds may be strongly affected by their three-dimensional atmospheric circulation regimes, since the global climate feedbacks that control the inner and outer edges of the habitable zone—including transitions to Snowball-like states and runaway-greenhouse feedbacks—depend on the equator-to-pole temperature differences, patterns of relative humidity, and other aspects of the dynamics. Here, using an idealized moist atmospheric general circulation model including a hydrological cycle, we study the dynamical principles governing the atmospheric dynamics on such planets. We show how the planetary rotation rate, stellar flux, atmospheric mass, surface gravity, optical thickness, and planetary radius affect the atmospheric circulation and temperature distribution on such planets. Our simulations demonstrate that equator-to-pole temperature differences, meridional heat transport rates, structure and strength of the winds, and the hydrological cycle vary strongly with these parameters, implying that the sensitivity of the planet to global climate feedbacks will depend significantly on the atmospheric circulation. We elucidate the possible climatic regimes and diagnose the mechanisms controlling the formation of atmospheric jet streams, Hadley and Ferrel cells, and latitudinal temperature differences. Finally, we discuss the implications for understanding how the atmospheric circulation influences the global climate.

  3. Natural selection constrains neutral diversity across a wide range of species.

    Science.gov (United States)

    Corbett-Detig, Russell B; Hartl, Daniel L; Sackton, Timothy B

    2015-04-01

    The neutral theory of molecular evolution predicts that the amount of neutral polymorphisms within a species will increase proportionally with the census population size (Nc). However, this prediction has not been borne out in practice: while the range of Nc spans many orders of magnitude, levels of genetic diversity within species fall in a comparatively narrow range. Although theoretical arguments have invoked the increased efficacy of natural selection in larger populations to explain this discrepancy, few direct empirical tests of this hypothesis have been conducted. In this work, we provide a direct test of this hypothesis using population genomic data from a wide range of taxonomically diverse species. To do this, we relied on the fact that the impact of natural selection on linked neutral diversity depends on the local recombinational environment. In regions of relatively low recombination, selected variants affect more neutral sites through linkage, and the resulting correlation between recombination and polymorphism allows a quantitative assessment of the magnitude of the impact of selection on linked neutral diversity. By comparing whole genome polymorphism data and genetic maps using a coalescent modeling framework, we estimate the degree to which natural selection reduces linked neutral diversity for 40 species of obligately sexual eukaryotes. We then show that the magnitude of the impact of natural selection is positively correlated with Nc, based on body size and species range as proxies for census population size. These results demonstrate that natural selection removes more variation at linked neutral sites in species with large Nc than those with small Nc and provides direct empirical evidence that natural selection constrains levels of neutral genetic diversity across many species. This implies that natural selection may provide an explanation for this longstanding paradox of population genetics.

  4. Wide range of socioeconomic factors associated with mortality among cities in Japan.

    Science.gov (United States)

    Fukuda, Yoshiharu; Nakamura, Keiko; Takano, Takehito

    2004-06-01

    The aim of this study was to identify socioeconomic factors associated with mortality among cities in Japan. Sex-specific and age-adjusted mortality rates for 1990 and 1995 were calculated by 779 local administrative units across the nation. One hundred indicators related to socioeconomic factors were compiled and divided into eight categories: economy, education, living conditions, vegetation and open space, transport, preventive activities, medical care and demography. Composite socioeconomic indices were formulated using factor analysis of the socioeconomic indicators by category, and the association between the indices and mortality rates was examined by correlation analysis and multiple regression analysis. Nineteen composite socioeconomic indices were obtained from factor analysis, and all indices except educational expenditure-related index were significantly correlated with mortality rates. Unemployment, old housing, primary health resources and density were independently positively associated, and higher education, public library activity, health check-up participation and population growth were independently negatively associated with both 1990 and 1995 male mortality rates. For female mortality, higher income, unemployment, spacious dwelling, old housing, less vegetation, road facility, numbers of cars per population, primary health resources and density were independently positively associated, and higher education, public library activity and health check-up participation were independently negatively associated. The relationship between mortality and socioeconomic conditions was stronger in males than in females, and higher income and less vegetation were associated with higher mortality only for females. The present study demonstrated a close link between mortality and a wide range of socioeconomic conditions by using a number of indicators compiled from various data sources. The results promote a deeper understanding of socioeconomic health

  5. Wide range of mercury contamination in chicks of southern ocean seabirds.

    Science.gov (United States)

    Blévin, Pierre; Carravieri, Alice; Jaeger, Audrey; Chastel, Olivier; Bustamante, Paco; Cherel, Yves

    2013-01-01

    Using top predators as sentinels of the marine environment, Hg contamination was investigated within the large subantarctic seabird community of Kerguelen Islands, a remote area from the poorly known Southern Indian Ocean. Chicks of 21 sympatric seabirds presented a wide range of Hg concentrations, with the highest contaminated species containing ~102 times more feather Hg than the less contaminated species. Hence, Kerguelen seabirds encompass the whole range of chick feather Hg values that were previously collected worldwide in poorly industrialized localities. Using stable isotopes, the effects of foraging habitats (reflected by δ(13)C) and trophic positions (reflected by δ(15)N) on Hg concentrations were investigated. Species-related Hg variations were highly and positively linked to feather δ(15)N values, thus highlighting the occurrence of efficient Hg biomagnification processes within subantarctic marine trophic webs. By contrast, Hg contamination overall correlated poorly with feeding habitats, because of the pooling of species foraging within different isotopic gradients corresponding to distinct seabird habitats (benthic, pelagic, neritic and oceanic). However, when focusing on oceanic seabirds, Hg concentration was related to feather δ(13)C values, with species feeding in colder waters (lower δ(13)C values) south of Kerguelen Islands being less prone to be contaminated than species feeding in northern warmer waters (higher δ(13)C values). Within the context of continuous increase in global Hg emissions, Kerguelen Islands that are located far away from anthropogenic sources can be considered as an ideal study site to monitor the temporal trend of global Hg contamination. The present work helps selecting some seabird species as sentinels of environmental pollution according to their high Hg concentrations and their contrasted foraging ecology.

  6. Modelling seasonal habitat suitability for wide-ranging species: Invasive wild pigs in northern Australia.

    Directory of Open Access Journals (Sweden)

    Jens G Froese

    Full Text Available Invasive wildlife often causes serious damage to the economy and agriculture as well as environmental, human and animal health. Habitat models can fill knowledge gaps about species distributions and assist planning to mitigate impacts. Yet, model accuracy and utility may be compromised by small study areas and limited integration of species ecology or temporal variability. Here we modelled seasonal habitat suitability for wild pigs, a widespread and harmful invader, in northern Australia. We developed a resource-based, spatially-explicit and regional-scale approach using Bayesian networks and spatial pattern suitability analysis. We integrated important ecological factors such as variability in environmental conditions, breeding requirements and home range movements. The habitat model was parameterized during a structured, iterative expert elicitation process and applied to a wet season and a dry season scenario. Model performance and uncertainty was evaluated against independent distributional data sets. Validation results showed that an expert-averaged model accurately predicted empirical wild pig presences in northern Australia for both seasonal scenarios. Model uncertainty was largely associated with different expert assumptions about wild pigs' resource-seeking home range movements. Habitat suitability varied considerably between seasons, retracting to resource-abundant rainforest, wetland and agricultural refuge areas during the dry season and expanding widely into surrounding grassland floodplains, savanna woodlands and coastal shrubs during the wet season. Overall, our model suggested that suitable wild pig habitat is less widely available in northern Australia than previously thought. Mapped results may be used to quantify impacts, assess risks, justify management investments and target control activities. Our methods are applicable to other wide-ranging species, especially in data-poor situations.

  7. [A wide-ranging project to the best use of S. Niccolo Psychiatric Hospital].

    Science.gov (United States)

    Vannozzi, Francesca

    2007-01-01

    The S. Niccolò Psychiatric Hospital was one of the most important health institutions not only for Siena but for the entire Tuscan district and beyond. It was known to serve all the catchment area for mentally ill patients coming from other cities. At a national level, it is also one of the most beautiful models of hospital architecture of the "village" type, the expression of a late nineteenth-century tendency to perceive mental disorders as illnesses that could be improved and cured through "moral treatment", with work and distraction as the principal therapeutic instruments. The closure of the psychiatric hospital in Siena provided for by the Italian psychiatric reform of 1978 actually took place over an extremely long period of time. It was definitively closed only on 30 September 1999 and was the last psychiatric hospital in Tuscany to cease its activity. Its history, the importance it had for the considerable number of committed patients, the extension of the area of the hospital over 183,574 m2 and its organization in 16 edifices, mean that S. Niccolò is now an architectonic complex of great value and interest but also subject to progressive deterioration. This reality, together with the urgency of salvaging the collections of books from its very rich library and its archives of administrative documents and medical records, has led the author to prepare a wide-ranging and extremely complex project that aims at the best use of S. Niccolò. Thanks to the collaboration of a group of experts from various Faculties of the University of Siena, and beginning with a multidisciplinary study of S. Niccolò's history, the project proceeds to the identification of concrete actions of cultural policy as well.

  8. A numerical shallow-water model for gravity currents for a wide range of density differences

    Science.gov (United States)

    Shimizu, Hiroyuki A.; Koyaguchi, Takehiro; Suzuki, Yujiro J.

    2017-12-01

    Gravity currents with various contrasting densities play a role in mass transport in a number of geophysical situations. The ratio of the density of the current, ρ c, to the density of the ambient fluid, ρ a, can vary between 100 and 103. In this paper, we present a numerical method of simulating gravity currents for a wide range of ρ c/ ρ a using a shallow-water model. In the model, the effects of varying ρ c/ ρ a are taken into account via the front condition (i.e., factors describing the balance between the driving pressure and the ambient resistance pressure at the flow front). Previously, two types of numerical models have been proposed to solve the front condition. These are referred to here as the Boundary Condition (BC) model and the Artificial Bed (AB) model. The front condition is calculated as a boundary condition at each time step in the BC model, whereas it is calculated by setting a thin artificial bed ahead of the front in the AB model. We assessed the BC and AB models by comparing their numerical results with the analytical results for a simple case of homogeneous currents. The results from the BC model agree well with the analytical results when ρ c/ ρ a≲102, but the model tends to overestimate the speed of the front position when ρ c/ρ a≳102. In contrast, the AB model generates good approximations of the analytical results for ρ c/ρ a≳ 102, given a sufficiently small artificial bed thickness, but fails to reproduce the analytical results when ρ c/ ρ a≲102. Therefore, we propose a numerical method in which the BC model is used for currents with ρ c/ ρ a≲102 and the AB model is used for currents with ρ c/ρ a≳ 102.

  9. Wide range of mercury contamination in chicks of southern ocean seabirds.

    Directory of Open Access Journals (Sweden)

    Pierre Blévin

    Full Text Available Using top predators as sentinels of the marine environment, Hg contamination was investigated within the large subantarctic seabird community of Kerguelen Islands, a remote area from the poorly known Southern Indian Ocean. Chicks of 21 sympatric seabirds presented a wide range of Hg concentrations, with the highest contaminated species containing ~102 times more feather Hg than the less contaminated species. Hence, Kerguelen seabirds encompass the whole range of chick feather Hg values that were previously collected worldwide in poorly industrialized localities. Using stable isotopes, the effects of foraging habitats (reflected by δ(13C and trophic positions (reflected by δ(15N on Hg concentrations were investigated. Species-related Hg variations were highly and positively linked to feather δ(15N values, thus highlighting the occurrence of efficient Hg biomagnification processes within subantarctic marine trophic webs. By contrast, Hg contamination overall correlated poorly with feeding habitats, because of the pooling of species foraging within different isotopic gradients corresponding to distinct seabird habitats (benthic, pelagic, neritic and oceanic. However, when focusing on oceanic seabirds, Hg concentration was related to feather δ(13C values, with species feeding in colder waters (lower δ(13C values south of Kerguelen Islands being less prone to be contaminated than species feeding in northern warmer waters (higher δ(13C values. Within the context of continuous increase in global Hg emissions, Kerguelen Islands that are located far away from anthropogenic sources can be considered as an ideal study site to monitor the temporal trend of global Hg contamination. The present work helps selecting some seabird species as sentinels of environmental pollution according to their high Hg concentrations and their contrasted foraging ecology.

  10. Modelling seasonal habitat suitability for wide-ranging species: Invasive wild pigs in northern Australia.

    Science.gov (United States)

    Froese, Jens G; Smith, Carl S; Durr, Peter A; McAlpine, Clive A; van Klinken, Rieks D

    2017-01-01

    Invasive wildlife often causes serious damage to the economy and agriculture as well as environmental, human and animal health. Habitat models can fill knowledge gaps about species distributions and assist planning to mitigate impacts. Yet, model accuracy and utility may be compromised by small study areas and limited integration of species ecology or temporal variability. Here we modelled seasonal habitat suitability for wild pigs, a widespread and harmful invader, in northern Australia. We developed a resource-based, spatially-explicit and regional-scale approach using Bayesian networks and spatial pattern suitability analysis. We integrated important ecological factors such as variability in environmental conditions, breeding requirements and home range movements. The habitat model was parameterized during a structured, iterative expert elicitation process and applied to a wet season and a dry season scenario. Model performance and uncertainty was evaluated against independent distributional data sets. Validation results showed that an expert-averaged model accurately predicted empirical wild pig presences in northern Australia for both seasonal scenarios. Model uncertainty was largely associated with different expert assumptions about wild pigs' resource-seeking home range movements. Habitat suitability varied considerably between seasons, retracting to resource-abundant rainforest, wetland and agricultural refuge areas during the dry season and expanding widely into surrounding grassland floodplains, savanna woodlands and coastal shrubs during the wet season. Overall, our model suggested that suitable wild pig habitat is less widely available in northern Australia than previously thought. Mapped results may be used to quantify impacts, assess risks, justify management investments and target control activities. Our methods are applicable to other wide-ranging species, especially in data-poor situations.

  11. Bedload transport flux fluctuations over a wide range of time scales

    Science.gov (United States)

    Ma, H.; Fu, X.; Ancey, C.

    2014-12-01

    Bedload transport is a highly fluctuating process. Our previous study (Ma et al., 2014) demonstrated a three-regime relation of the variance of bedload transport flux across a wide range of sampling time scales. This study further explored the fluctuation spectrum of at-a-point bedload transport flux with different sampling times. We derived out analytical solutions of the third- and fourth-order moments of bedload transport flux, based on a physically-based formulation (Ancey et al., 2008; Ma et al., 2014). A formulation of the probability density function of bedload transport flux was constructed based on the 1st through 4th order moments. Experimental data were used to test against the solutions of both the moments and PDF. Interestingly, the higher order statistical moments were found to exhibit the three-regime pattern as well. This study contributes to a comprehensive understanding of bedload transport flux fluctuation and emphasizes its timescale-dependent features resulting from the discrete nature and correlated motion of bedload material. The correlated structures of bedload transport, such as bed forms and particle clusters, deserve to be further exploration in future studies. Keywords: bedload transport; stochastic theory; high order moment; fluctuation; time scale; PDF. Ancey, C., Davison, A. C., Bohm, T., Jodeau, M., and Frey, P. Entrainment and motion of coarse particles in a shallow water stream down a steep slope, Journal of Fluid Mechanics, 2008, 595, 83-114, doi: 10.1017/S0022112007008774. Ma, H. B., Heyman, J., Fu, X. D., Mettra, F., Ancey, C. and Parker, G. Bedload transport over a broad range of time scales: determination of three regimes of fluctuations. Journal of Geophysical Research-Earth Surface, 2014. (under review)

  12. Choice of alpha-probe operating voltage to suit a wide range of conditions.

    Science.gov (United States)

    Bosley, R B; Simpson, J A

    2002-09-01

    Alpha probes, consisting of a ZnS(Ag) scintillator and a photo-multiplier tube, are commonly used throughout the nuclear industry for radiation protection and clearance of materials during decommissioning. The success in achieving these purposes is dependent on a number of factors including the counting efficiency of the probe, the condition of the material being monitored, the speed of monitoring and the distance between the probe and material. The efficiency of the probe is dependent on the operating voltage and is the only factor that is under the control of the calibration facility. As the calibration laboratory may not be aware of the specific environment in which the probe will be used, an operating voltage to suite a wide range of conditions must be chosen. In the past, it has frequently been assumed that it is necessary to set as high an operating voltage as possible in order to maximise the counting efficiency to low-energy alpha particles. However, the response to gamma rays, particularly those having low energies, also increases with operating voltage and will therefore limit the upper operating voltage that can be set. The efficiency of a scintillation-type probe (NE Technology AP2) in measuring contamination levels on a number of typical surfaces using different operating voltages has been investigated. It has been found that the surface characteristics of the material being monitored have far more effect on the results of alpha monitoring than the choice of operating voltage. Thus the calibration laboratory can set the operating voltage below the level at which there is a risk of response to low-energy gamma rays without significantly affecting the overall counting efficiency for low-energy alpha particles.

  13. A wide-range model for simulation of pump-probe experiments with metals

    Energy Technology Data Exchange (ETDEWEB)

    Povarnitsyn, Mikhail E., E-mail: povar@ihed.ras.ru [Joint Institute for High Temperatures RAS, Izhorskaya 13 Bldg 2, Moscow, 125412 (Russian Federation); Andreev, Nikolay E. [Joint Institute for High Temperatures RAS, Izhorskaya 13 Bldg 2, Moscow, 125412 (Russian Federation); Moscow Institute of Physics and Technology (State University), Institutsky lane 9, Dolgoprudny, Moscow region, 141700 (Russian Federation); Apfelbaum, Eugeny M. [Joint Institute for High Temperatures RAS, Izhorskaya 13 Bldg 2, Moscow, 125412 (Russian Federation); Itina, Tatiana E. [Joint Institute for High Temperatures RAS, Izhorskaya 13 Bldg 2, Moscow, 125412 (Russian Federation); Laboratoire Hubert Curien, UMR CNRS 5516, 18 rue Benoit Lauras, Bat. F, 42000, St-Etienne (France); Khishchenko, Konstatntin V. [Joint Institute for High Temperatures RAS, Izhorskaya 13 Bldg 2, Moscow, 125412 (Russian Federation); Moscow Institute of Physics and Technology (State University), Institutsky lane 9, Dolgoprudny, Moscow region, 141700 (Russian Federation); Kostenko, Oleg F. [Joint Institute for High Temperatures RAS, Izhorskaya 13 Bldg 2, Moscow, 125412 (Russian Federation); Levashov, Pavel R. [Joint Institute for High Temperatures RAS, Izhorskaya 13 Bldg 2, Moscow, 125412 (Russian Federation); Moscow Institute of Physics and Technology (State University), Institutsky lane 9, Dolgoprudny, Moscow region, 141700 (Russian Federation); Veysman, Mikhail E. [Joint Institute for High Temperatures RAS, Izhorskaya 13 Bldg 2, Moscow, 125412 (Russian Federation)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer Pump-probe experiments provide an integral test of the models in the theoretically difficult regime of warm dense matter. Black-Right-Pointing-Pointer The target material motion is evident for heating by femtosecond pulses of intensity more than 10{sup 14} W/cm{sup 2}. Black-Right-Pointing-Pointer Phase shift of S and P-polarized pulses is different because of separated zones of absorption. Black-Right-Pointing-Pointer Uncertainty in the pulse energy determination of {approx}10% gives substantial deflection of the theoretical curves. Black-Right-Pointing-Pointer The surface target oxide films may result in bigger phase shift in experiment. - Abstract: High precision pump-probe experiments can provide a valuable information about material states out of equilibrium. A wide-range numerical model is used for the description of material response on ultrashort laser action. The model is developed on the basis of two-temperature hydrodynamics with heat transport, ionization, plasma expansion, electron-ion collisions and two-temperature equation of state for an irradiated substance. Comparison of experimental findings with the results of simulation is used both for the numerical model verification and for calculation of plasma thermodynamic parameters that cannot be measured directly in experiment. An aluminum target is heated by an intense 400 nm (2{omega}) pump laser pulse that is incident normal to the planar target. Weak S- and P-polarized probe pulses with wavelength 800 nm (1{omega}) are used for diagnostics of the plasma. Both probe pulses illuminate the target at a 45 Degree-Sign angle. Calculation of the reflectivity and phase shift of probe pulses with both polarizations are in good agreement with experiment.

  14. Rat injury model under controlled field-relevant primary blast conditions: acute response to a wide range of peak overpressures.

    Science.gov (United States)

    Skotak, Maciej; Wang, Fang; Alai, Aaron; Holmberg, Aaron; Harris, Seth; Switzer, Robert C; Chandra, Namas

    2013-07-01

    We evaluated the acute (up to 24 h) pathophysiological response to primary blast using a rat model and helium driven shock tube. The shock tube generates animal loadings with controlled pure primary blast parameters over a wide range and field-relevant conditions. We studied the biomechanical loading with a set of pressure gauges mounted on the surface of the nose, in the cranial space, and in the thoracic cavity of cadaver rats. Anesthetized rats were exposed to a single blast at precisely controlled five peak overpressures over a wide range (130, 190, 230, 250, and 290 kPa). We observed 0% mortality rates in 130 and 230 kPa groups, and 30%, 24%, and 100% mortality rates in 190, 250, and 290 kPa groups, respectively. The body weight loss was statistically significant in 190 and 250 kPa groups 24 h after exposure. The data analysis showed the magnitude of peak-to-peak amplitude of intracranial pressure (ICP) fluctuations correlates well with mortality rates. The ICP oscillations recorded for 190, 250, and 290 kPa are characterized by higher frequency (10-20 kHz) than in other two groups (7-8 kHz). We noted acute bradycardia and lung hemorrhage in all groups of rats subjected to the blast. We established the onset of both corresponds to 110 kPa peak overpressure. The immunostaining against immunoglobulin G (IgG) of brain sections of rats sacrificed 24-h post-exposure indicated the diffuse blood-brain barrier breakdown in the brain parenchyma. At high blast intensities (peak overpressure of 190 kPa or more), the IgG uptake by neurons was evident, but there was no evidence of neurodegeneration after 24 h post-exposure, as indicated by cupric silver staining. We observed that the acute response as well as mortality is a non-linear function over the peak overpressure and impulse ranges explored in this work.

  15. Wide-Range Highly-Efficient Wireless Power Receivers for Implantable Biomedical Sensors

    KAUST Repository

    Ouda, Mahmoud

    2016-11-01

    Wireless power transfer (WPT) is the key enabler for a myriad of applications, from low-power RFIDs, and wireless sensors, to wirelessly charged electric vehicles, and even massive power transmission from space solar cells. One of the major challenges in designing implantable biomedical devices is the size and lifetime of the battery. Thus, replacing the battery with a miniaturized wireless power receiver (WPRx) facilitates designing sustainable biomedical implants in smaller volumes for sentient medical applications. In the first part of this dissertation, we propose a miniaturized, fully integrated, wirelessly powered implantable sensor with on-chip antenna, designed and implemented in a standard 0.18μm CMOS process. As a batteryless device, it can be implanted once inside the body with no need for further invasive surgeries to replace batteries. The proposed single-chip solution is designed for intraocular pressure monitoring (IOPM), and can serve as a sustainable platform for implantable devices or IoT nodes. A custom setup is developed to test the chip in a saline solution with electrical properties similar to those of the aqueous humor of the eye. The proposed chip, in this eye-like setup, is wirelessly charged to 1V from a 5W transmitter 3cm away from the chip. In the second part, we propose a self-biased, differential rectifier with enhanced efficiency over an extended range of input power. A prototype is designed for the medical implant communication service (MICS) band at 433MHz. It demonstrates an efficiency improvement of more than 40% in the rectifier power conversion efficiency (PCE) and a dynamic range extension of more than 50% relative to the conventional cross-coupled rectifier. A sensitivity of -15.2dBm input power for 1V output voltage and a peak PCE of 65% are achieved for a 50k load. In the third part, we propose a wide-range, differential RF-to-DC power converter using an adaptive, self-biasing technique. The proposed architecture doubles

  16. Multiwavelength monitoring of QS Tel

    Science.gov (United States)

    Rosen, S. R.; Rainger, J. F.; Burleigh, M. R.; Mittaz, J. P. D.; Buckley, D. A. H.; Sirk, M. M.; Lieu, R.; Howell, S. B.; de Martino, D.

    2001-04-01

    Multiwavelength monitoring observations of the AM Her system, QS Tel, are presented, the centrepiece being a coordinated campaign with the ASCA, EUVE and HST satellites and optical observations on 1996 September 28-29. The star was initially observed in an intermediate brightness, single pole state in 1996 April by ROSAT. However two EUVE snapshots of the system in August found it in a deep low state, the light curves appearing to retain a bright and faint phase morphology although the bright interval showed significant phase drifts compared with the earlier ROSAT data. At this time, the system appeared optically bright, while polarimetry pointed to one active pole. A modest recovery of intensity, albeit accompanied by an apparently chaotic extreme ultraviolet (EUV) light curve, was subsequently recorded during the coordinated run in late September. This brightening was confirmed by a second ROSAT pointing in early October, although the EUV brightening is matched by a marked decay in its optical output. These observations, all of which found the system in a fainter EUV state than seen in 1993, add to the catalogue of accretion mode behaviour in QS Tel. However, as yet, the data base of observations does not allow us to establish whether the accretion mode is dictated by accretion-rate dependent penetration of the magnetosphere or asynchronous rotation. The ASCA spectrum obtained during the coordinated observation is adequately described by a thermal spectrum with a temperature of about 4.4keV and an absorbing column density of less than 8×1020cm-2. At the same time, the 1150-2600Å UV HST spectrum shows a strong, broad Lyα absorption profile which we attribute to the white dwarf. We infer an effective temperature of 16000-19000K and a mass between 0.5 and 0.93Msolar for the white dwarf, at least some of the uncertainty arising because the profile is very probably contaminated and broadened by Zeeman features. The orbital variation seen by HST can be matched by a

  17. GRB 030227: The first multiwavelength afterglow of an INTEGRAL GRB

    DEFF Research Database (Denmark)

    Castro-Tirado, A.J.; Gorosabel, J.; Guziy, S.

    2003-01-01

    We present multiwavelength observations of a gamma-ray burst detected by INTEGRAL (GRB 030227) between 5.3 hours and similar to1.7 days after the event. Here we report the discovery of a dim optical afterglow (OA) that would not have been detected by many previous searches due to its faintess (R...

  18. Acidic pH shock induces the expressions of a wide range of stress-response genes

    Directory of Open Access Journals (Sweden)

    Hong Soon-Kwang

    2008-12-01

    Full Text Available Abstract Background Environmental signals usually enhance secondary metabolite production in Streptomycetes by initiating complex signal transduction system. It is known that different sigma factors respond to different types of stresses, respectively in Streptomyces strains, which have a number of unique signal transduction mechanisms depending on the types of environmental shock. In this study, we wanted to know how a pH shock would affect the expression of various sigma factors and shock-related proteins in S. coelicolor A3(2. Results According to the results of transcriptional and proteomic analyses, the major number of sigma factor genes were upregulated by an acidic pH shock. Well-studied sigma factor genes of sigH (heat shock, sigR (oxidative stress, sigB (osmotic shock, and hrdD that play a major role in the secondary metabolism, were all strongly upregulated by the pH shock. A number of heat shock proteins including the DnaK family and chaperones such as GroEL2 were also observed to be upregulated by the pH shock, while their repressor of hspR was strongly downregulated. Oxidative stress-related proteins such as thioredoxin, catalase, superoxide dismutase, peroxidase, and osmotic shock-related protein such as vesicle synthases were also upregulated in overall. Conclusion From these observations, an acidic pH shock was considered to be one of the strongest stresses to influence a wide range of sigma factors and shock-related proteins including general stress response proteins. The upregulation of the sigma factors and shock proteins already found to be related to actinorhodin biosynthesis was considered to have contributed to enhanced actinorhodin productivity by mediating the pH shock signal to regulators or biosynthesis genes for actinorhodin production.

  19. The effect of magnetic fields on gamma-ray bursts inferred from multi-wavelength observations of the burst of 23 January 1999

    NARCIS (Netherlands)

    Galama, TJ; Briggs, MS; Wijers, RAMJ; Rol, E; Band, D; van Paradijs, J; Kouveliotou, C; Preece, RD; Smith, IA; Tilanus, RPJ; de Bruyn, AG; Strom, RG; Pooley, G; Castro-Tirado, AJ; Tanvir, N; Robinson, C; Hurley, K; Heise, J; Telting, J; Rutten, RGM; Packham, C; Swaters, R; Fassia, A; Green, SF; Foster, MJ; Sagar, R; Pandey, AK; Nilakshi, [No Value; Yadav, RKS; Ofek, EO; Leibowitz, E; Ibbetson, P; Rhoads, J; Falco, E; Petry, C; Impey, C; Geballe, TR; Bhattacharya, D

    1999-01-01

    Gamma-ray bursts (GRBs) are thought to arise when an extremely relativistic outflow of particles from a massive explosion (the nature of which is still unclear) Interacts with material surrounding the site of the explosion. observations of the evolving changes in emission at many wavelengths allow

  20. Swift multi-wavelength observations of the high-redshift Blazar S5 0836+710 (4C 71.07)

    Science.gov (United States)

    Vercellone, Stefano; Romano, Patrizia; Raiteri, Claudia Maria; Acosta Pulido, Jose; Villata, Massimo; Carnerero Martin, Maria Isabel

    2016-04-01

    We present the preliminary results of a year-long Swift monitoring campaign of the high-redshift (z=2.172) flat-spectrum radio quasar (FSRQ) S5 0836+710 (4C 71.07). The campaign, based on one observation per month, 5 ks each observation, for 12 months, allowed us to investigate the synchrotron and nuclear emission contributions to the optical-UV frequency range of its spectral energy distribution and the X-ray spectral variations along a baseline of a year. We obtained a high-accuracy determination of UVOT magnitudes, an X-ray photon index with an uncertainty of the order of 5%, and well-sampled light curves both in the optical-UV and X-ray energy bands to study their possible modulations and correlations. Our study allowed us to exploit the unique Swift capabilities in terms of both simultaneous energy coverage and schedule flexibility. The Swift monitoring campaign was supported by observations by the GLAST-AGILE Support Program (GASP) of the Whole Earth Blazar Telescope (WEBT) Collaboration, which provided radio, near-infrared, and optical photometric data as well as optical polarimetry. Moreover, a spectroscopic monitoring was obtained at the William Herschel Telescope (WHT) and the Nordic Optical Telescope (NOT). All these observations will allow us to obtain a comprehensive picture of the jet as well as of the nuclear source emission.

  1. Investigating early-type galaxy evolution with a multiwavelength approach - I. X-ray properties of 12 galaxies observed with Swift and XMM-Newton

    Science.gov (United States)

    Trinchieri, G.; Rampazzo, R.; Mazzei, P.; Marino, A.; Wolter, A.

    2015-05-01

    We report here the results from the X-ray observations of 12 early-type galaxies (ETGs) observed with Swift and XMM-Newton, originally selected from a sample of galaxies with Spitzer and/or GALEX data. With the combined analysis of new X-ray and optical-UV observations and of previously available data from archives, we aim at investigating the relation between X-ray luminosity and evolutionary phases of ETGs. We will interpret the results with the additional aid of smoothed particle hydrodynamics chemo-photometric simulations. All galaxies have been detected in the X-ray band, with luminosities Lx > 1039 erg s-1. X-ray emitting gas has been detected in about half of the sample, with luminosities from ≥1039 to 1040 erg s-1. UVOT images show a variety of morphologies, from absence of peculiar features relative to optical wavelengths typical of red and dead early-types, to well defined almost circular rings clearly emerging in the U band, to more spectacular and complex features connected to recent or even ongoing star formation (SF). We find little evidence of any influence of the SF activity on their global X-ray properties, and in particular, on the luminosity-weighted age of the system, usually estimated in the nuclear region. However, with the present data we cannot exclude that such a relation exists on smaller scales, related to the specific sites where we see evidence of newly formed stars, such as outer rings and arcs and peculiar features observed in UV images.

  2. Probing AGN Physics with Kepler and Multiwavelength Variability

    Science.gov (United States)

    Edelson, Rick

    spanning a wide range of mass and Eddington ratio, allowing us to test for the expected correlation of variability timescales with black hole mass and accretion rate. These analyses will lead to new constraints on the physical conditions and mechanisms responsible for AGN optical variability. We are also conducting multiwavelength monitoring of Kepler AGN. Our first campaign involved contemporaneous Swift/Suzaku/Kepler monitoring of the Seyfert 1 galaxy Zw 229-15 and we are currently gathering Swift data in order to determine the best candidates for future Kepler/X-ray campaigns. These data could allow the first direct "reverberation mapping" measurements of the size of the accretion disk. We are also gathering other simultaneous monitoring of the Kepler AGN, e.g., emission-line monitoring by the LAMP consortium, to better define the transfer function and to estimate the BLR size and black hole mass. Our efforts have also led to discovery of the first highly-variable Kepler BL Lac object in the Kepler field, producing what is by far the best optical light curve ever obtained for a BL Lac. This object's PSD shows a sharp cutoff on a time scale of ~5 hr, much shorter than the lower limits set for Seyfert 1s. The RMS/flux relation is also clearly non-linear, the first such measurement for a BL Lac. Kepler's key legacy for AGN studies will be its rich archive of high-precision, long- duration, intensively-sampled light curves. The goal of this proposal is to build this archive in order to maximize Kepler's scientific output and our understanding of the central regions of AGN.

  3. Live cell plasma membranes do not exhibit a miscibility phase transition over a wide range of temperatures.

    Science.gov (United States)

    Lee, Il-Hyung; Saha, Suvrajit; Polley, Anirban; Huang, Hector; Mayor, Satyajit; Rao, Madan; Groves, Jay T

    2015-03-26

    Lipid/cholesterol mixtures derived from cell membranes as well as their synthetic reconstitutions exhibit well-defined miscibility phase transitions and critical phenomena near physiological temperatures. This suggests that lipid/cholesterol-mediated phase separation plays a role in the organization of live cell membranes. However, macroscopic lipid-phase separation is not generally observed in cell membranes, and the degree to which properties of isolated lipid mixtures are preserved in the cell membrane remain unknown. A fundamental property of phase transitions is that the variation of tagged particle diffusion with temperature exhibits an abrupt change as the system passes through the transition, even when the two phases are distributed in a nanometer-scale emulsion. We support this using a variety of Monte Carlo and atomistic simulations on model lipid membrane systems. However, temperature-dependent fluorescence correlation spectroscopy of labeled lipids and membrane-anchored proteins in live cell membranes shows a consistently smooth increase in the diffusion coefficient as a function of temperature. We find no evidence of a discrete miscibility phase transition throughout a wide range of temperatures: 14-37 °C. This contrasts the behavior of giant plasma membrane vesicles (GPMVs) blebbed from the same cells, which do exhibit phase transitions and macroscopic phase separation. Fluorescence lifetime analysis of a DiI probe in both cases reveals a significant environmental difference between the live cell and the GPMV. Taken together, these data suggest the live cell membrane may avoid the miscibility phase transition inherent to its lipid constituents by actively regulating physical parameters, such as tension, in the membrane.

  4. Logistic regression accuracy across different spatial and temporal scales for a wide-ranging species, the marbled murrelet

    Science.gov (United States)

    Carolyn B. Meyer; Sherri L. Miller; C. John Ralph

    2004-01-01

    The scale at which habitat variables are measured affects the accuracy of resource selection functions in predicting animal use of sites. We used logistic regression models for a wide-ranging species, the marbled murrelet, (Brachyramphus marmoratus) in a large region in California to address how much changing the spatial or temporal scale of...

  5. Construct Validity of the Wechsler Abbreviated Scale of Intelligence and Wide Range Intelligence Test: Convergent and Structural Validity

    Science.gov (United States)

    Canivez, Gary L.; Konold, Timothy R.; Collins, Jason M.; Wilson, Greg

    2009-01-01

    The Wechsler Abbreviated Scale of Intelligence (WASI; Psychological Corporation, 1999) and the Wide Range Intelligence Test (WRIT; Glutting, Adams, & Sheslow, 2000) are two well-normed brief measures of general intelligence with subtests purportedly assessing verbal-crystallized abilities and nonverbal-fluid-visual abilities. With a sample of…

  6. Preliminary assessment of the ecological risks to wide-ranging wildlife species on the Oak Ridge Reservation

    Energy Technology Data Exchange (ETDEWEB)

    Sample, B.E.; Baron, L.A.; Jackson, B.L.

    1995-08-01

    Historically, ecological risk assessment at CERCLA sites [such as the Oak Ridge Reservation (ORR)], has focused on species that may be definitively associated with a contaminated area or source operable unit. Consequently the species that are generally considered are those with home ranges small enough such that multiple individuals or a distinct population can be expected to reside within the boundaries of the contaminated site. This approach is adequate for sites with single, discrete areas of contamination that only provide habitat for species with limited requirements. This approach is not adequate however for large sites with multiple, spatially separated contaminated areas that provide habitat for wide-ranging wildlife species. Because wide-ranging wildlife species may travel between and use multiple contaminated sites they may be exposed to and be at risk from contaminants from multiple locations. Use of a particular contaminated site by wide-ranging species will be dependent upon the amount of suitable habitat available at that site. Therefore to adequately evaluate risks to wide-ranging species at the ORR-wide scale, the use of multiple contaminated sites must be weighted by the amount of suitable habitat on OUs. This reservation-wide ecological risk assessment is intended to identify which endpoints are significantly at risk; which contaminants are responsible for this risk; and which OUs significantly contribute to risk.

  7. Are simple empirical crop coefficient approaches for determining pecan water use readily transferrable across a wide range of conditions?

    CSIR Research Space (South Africa)

    Taylor, NJ

    2017-02-01

    Full Text Available to easier parameterization and the requirements for fewer, more easily measured input parameters, they may not always be transferable across a wide range of conditions. As a result these models may not always give acceptably accurate ET values outside...

  8. Constraining the Structure of the Transition Disk HD 135344B (SAO 206462) by Simultaneous Modeling of Multiwavelength Gas and Dust Observations

    Science.gov (United States)

    Carmona, A.; Pinte, C.; Thi, W. F.; Benisty, M.; Menard, F.; Grady, C.; Kamp, I.; Woitke, P.; Olofsson, J.; Roberge, A.; hide

    2014-01-01

    Context: Constraining the gas and dust disk structure of transition disks, particularly in the inner dust cavity, is a crucial step toward understanding the link between them and planet formation. HD 135344B is an accreting (pre-)transition disk that displays the CO 4.7 micrometer emission extending tens of AU inside its 30 AU dust cavity. Aims: We constrain HD 135344B's disk structure from multi-instrument gas and dust observations. Methods: We used the dust radiative transfer code MCFOST and the thermochemical code ProDiMo to derive the disk structure from the simultaneous modeling of the spectral energy distribution (SED), VLT/CRIRES CO P(10) 4.75 Micrometers, Herschel/PACS [O(sub I)] 63 Micrometers, Spitzer/IRS, and JCMT CO-12 J = 3-2 spectra, VLTI/PIONIER H-band visibilities, and constraints from (sub-)mm continuum interferometry and near-IR imaging. Results: We found a disk model able to describe the current gas and dust observations simultaneously. This disk has the following structure. (1) To simultaneously reproduce the SED, the near-IR interferometry data, and the CO ro-vibrational emission, refractory grains (we suggest carbon) are present inside the silicate sublimation radius (0.08 is less than R less than 0.2 AU). (2) The dust cavity (R is less than 30 AU) is filled with gas, the surface density of the gas inside the cavity must increase with radius to fit the CO ro-vibrational line profile, a small gap of a few AU in the gas distribution is compatible with current data, and a large gap of tens of AU in the gas does not appear likely. (4) The gas-to-dust ratio inside the cavity is >100 to account for the 870 Micrometers continuum upper limit and the CO P(10) line flux. (5) The gas-to-dust ratio in the outer disk (30 is less than R less than 200 AU) is less than 10 to simultaneously describe the [O(sub I)] 63 Micrometers line flux and the CO P(10) line profile. (6) In the outer disk, most of the gas and dust mass should be located in the midplane, and

  9. Tracking Galaxy Evolution Through Low-Frequency Radio Continuum Observations using SKA and Citizen-Science Research using Multi-Wavelength Data

    Science.gov (United States)

    Hota, Ananda; Konar, C.; Stalin, C. S.; Vaddi, Sravani; Mohanty, Pradeepta K.; Dabhade, Pratik; Dharmik Bhoga, Sai Arun; Rajoria, Megha; Sethi, Sagar

    2016-12-01

    We present a brief review of progress in the understanding of general spiral and elliptical galaxies, through merger, star formation and AGN activities. With reference to case studies performed with the GMRT, we highlight the unique aspects of studying galaxies in the radio wavelengths where powerful quasars and bright radio galaxies are traditionally the dominating subjects. Though AGN or quasar activity is extremely energetic, it is extremely short-lived. This justify focussing on transitional galaxies to find relic-evidences of the immediate past AGN-feedback which decide the future course of evolution of a galaxy. Relic radio lobes can be best detected in low frequency observations with the GMRT, LOFAR and in future SKA. The age of these relic radio plasma can be as old as a few hundred Myr. There is a huge gap between this and what is found in optical bands. The very first relic-evidences of a past quasar activity (Hanny's Voorwerp) was discovered in 2007 by a Galaxy Zoo citizen-scientist, a school teacher, in the optical bands. This relic is around a few tens of thousand years old. More discoveries needed to match these time-scales with star formation time-scales in AGN host galaxies to better understand black hole galaxy co-evolution process via feedback-driven quenching of star formation. It is now well-accepted that discovery and characterization of such faint fuzzy relic features can be more efficiently done by human eye than a machine. Radio interferometry images are more complicated than optical and need the citizen-scientists to be trained. RAD@home, the only Indian citizen-science research project in astronomy, analysing TIFR GMRT Sky Survey (TGSS) 150 MHz data and observing from the Giant Meterwave Radio Telescope (GMRT), was launched in April 2013. Unique, zero-infrastructure zero-funded design of RAD@home as a collaboratory of 69 trained e-astronomers is briefly described. Some of the new-found objects like episodic radio galaxies, radio-jet and

  10. Morphology of quantified ionospheric range spread-F over a wide range of midlatitudes in the Australian longitudinal sector

    Directory of Open Access Journals (Sweden)

    L. A. Hajkowicz

    2007-06-01

    Full Text Available Ionograms from a standard vertical-incidence ionosonde chain (nine stations, obtained over a wide range of southern latitudes (in geom.lat. range: 23°–52° S, were digitally scanned at 5-min intervals at nighttime (18:00–06:00 LT for 13 months (January 2004–January 2005. An important parameter of the F-region, so-called range spread-F (Sr, was for the first time quantified in km. Maximum in Sr was recorded at a sounding frequency of 1.8 MHz for each night and for each ionosonde station. A distinct pattern in the magnitude (in km and in the percentage occurrence of the range spread-F was present in southern winter only (the June solstice. The sub-auroral region (geom. lat. ≥52° S is characterised by consistently high spread-F (average Sr≈100 km on 80–100 per cent of the observed nights. There is a sharp equatorward boundary in the spread-F activity in a latitudinal range: 52°–48° S followed by a midlatitude region (44°–48° S which exhibits a peak in Sr (≈50 km in winter only, observed on half of the nights. The midlatitude activity reaches its minimum at 42°–43° S, with Sr less than 20 km on one third of the nights. The low midlatitudes (23°–36° S are characterised by a strong peak in Sr again in winter, centred at about 30° S (average Sr≈70 km on 80 per cent of the nights. The pattern becomes largely absent during other seasons particularly in southern summer (the December solstice when spread-F activity shifts to sub-auroral latitudes. The pattern in the occurrence of spread-F appears to have a global character as the enhanced spread-F activity is observed in the Japanese sector in local summer (i.e. the June solstice. It appears that the midlatitude spread-F minimum is only apparent but not real. It delineates the boundary between aurorally generated spread-F (due to travelling ionospheric disturbances, TIDs and low midlatitude spread-F whose origin is not known.

  11. Morphology of quantified ionospheric range spread-F over a wide range of midlatitudes in the Australian longitudinal sector

    Directory of Open Access Journals (Sweden)

    L. A. Hajkowicz

    2007-06-01

    Full Text Available Ionograms from a standard vertical-incidence ionosonde chain (nine stations, obtained over a wide range of southern latitudes (in geom.lat. range: 23°–52° S, were digitally scanned at 5-min intervals at nighttime (18:00–06:00 LT for 13 months (January 2004–January 2005. An important parameter of the F-region, so-called range spread-F (Sr, was for the first time quantified in km. Maximum in Sr was recorded at a sounding frequency of 1.8 MHz for each night and for each ionosonde station. A distinct pattern in the magnitude (in km and in the percentage occurrence of the range spread-F was present in southern winter only (the June solstice. The sub-auroral region (geom. lat. ≥52° S is characterised by consistently high spread-F (average Sr≈100 km on 80–100 per cent of the observed nights. There is a sharp equatorward boundary in the spread-F activity in a latitudinal range: 52°–48° S followed by a midlatitude region (44°–48° S which exhibits a peak in Sr (≈50 km in winter only, observed on half of the nights. The midlatitude activity reaches its minimum at 42°–43° S, with Sr less than 20 km on one third of the nights. The low midlatitudes (23°–36° S are characterised by a strong peak in Sr again in winter, centred at about 30° S (average Sr≈70 km on 80 per cent of the nights. The pattern becomes largely absent during other seasons particularly in southern summer (the December solstice when spread-F activity shifts to sub-auroral latitudes. The pattern in the occurrence of spread-F appears to have a global character as the enhanced spread-F activity is observed in the Japanese sector in local summer (i.e. the June solstice.

    It appears that the midlatitude spread-F minimum is only apparent but not real. It delineates the boundary between aurorally generated spread-F (due to travelling ionospheric disturbances, TIDs and low midlatitude spread-F whose origin is not known.

  12. Elastic precursor wave decay in shock-compressed aluminum over a wide range of temperature

    Science.gov (United States)

    Austin, Ryan A.

    2018-01-01

    The effect of temperature on the dynamic flow behavior of aluminum is considered in the context of precursor wave decay measurements and simulations. In this regard, a dislocation-based model of high-rate metal plasticity is brought into agreement with previous measurements of evolving wave profiles at 300 to 933 K, wherein the amplification of the precursor structure with temperature arises naturally from the dislocation mechanics treatment. The model suggests that the kinetics of inelastic flow and stress relaxation are governed primarily by phonon scattering and radiative damping (sound wave emission from dislocation cores), both of which intensify with temperature. The manifestation of these drag effects is linked to low dislocation density ahead of the precursor wave and the high mobility of dislocations in the face-centered cubic lattice. Simulations performed using other typical models of shock wave plasticity do not reproduce the observed temperature-dependence of elastic/plastic wave structure.

  13. Elastic precursor wave decay in shock-compressed aluminum over a wide range of temperature

    Science.gov (United States)

    Austin, Ryan

    2017-06-01

    As a part of broader efforts to understand the dynamic strength of metals, precursor wave decay measurements are well-situated to probe time-dependent flow behavior at relatively high strain rates and low strain levels. Such measurements provide crucial data to help constrain models of underlying deformation mechanisms and microstructure evolution under shock wave loading. In previous work, wave structures were measured in aluminum plate impact experiments performed at temperatures ranging from 300 K to just below the ambient melting point (933 K). These measurements serve as a basis for evaluating and refining a dislocation-based model of high-rate metal plasticity. In the experiments, the precursor wave amplitudes were observed to increase with temperature. This effect is usually explained in terms of the temperature dependence of dislocation phonon scattering (i.e., the linear regime of damped dislocation mobility). However, the model predicts that phonon radiation provides a somewhat stronger damping effect at all temperatures, given the high speeds attained by the dislocations. The combined effects of phonon scattering and radiation then seem to be responsible for the measured precursor amplifications. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 (LLNL-ABS-724488).

  14. Vesicular stomatitis virus enables gene transfer and transsynaptic tracing in a wide range of organisms

    Science.gov (United States)

    Mundell, Nathan A.; Beier, Kevin T.; Pan, Y. Albert; Lapan, Sylvain W.; Göz Aytürk, Didem; Berezovskii, Vladimir K.; Wark, Abigail R.; Drokhlyansky, Eugene; Bielecki, Jan; Born, Richard T.; Schier, Alexander F.

    2015-01-01

    Current limitations in technology have prevented an extensive analysis of the connections among neurons, particularly within nonmammalian organisms. We developed a transsynaptic viral tracer originally for use in mice, and then tested its utility in a broader range of organisms. By engineering the vesicular stomatitis virus (VSV) to encode a fluorophore and either the rabies virus glycoprotein (RABV‐G) or its own glycoprotein (VSV‐G), we created viruses that can transsynaptically label neuronal circuits in either the retrograde or anterograde direction, respectively. The vectors were investigated for their utility as polysynaptic tracers of chicken and zebrafish visual pathways. They showed patterns of connectivity consistent with previously characterized visual system connections, and revealed several potentially novel connections. Further, these vectors were shown to infect neurons in several other vertebrates, including Old and New World monkeys, seahorses, axolotls, and Xenopus. They were also shown to infect two invertebrates, Drosophila melanogaster, and the box jellyfish, Tripedalia cystophora, a species previously intractable for gene transfer, although no clear evidence of transsynaptic spread was observed in these species. These vectors provide a starting point for transsynaptic tracing in most vertebrates, and are also excellent candidates for gene transfer in organisms that have been refractory to other methods. J. Comp. Neurol. 523:1639–1663, 2015. © 2015 Wiley Periodicals, Inc. PMID:25688551

  15. Wide range instantaneous temperature measurements of convective fluid flows by using a schlieren system based in color images

    Science.gov (United States)

    Martínez-González, A.; Moreno-Hernández, D.; Monzón-Hernández, D.; León-Rodríguez, M.

    2017-06-01

    In the schlieren method, the deflection of light by the presence of an inhomogeneous medium is proportional to the gradient of its refractive index. Such deflection, in a schlieren system, is represented by light intensity variations on the observation plane. Then, for a digital camera, the intensity level registered by each pixel depends mainly on the variation of the medium refractive index and the status of the digital camera settings. Therefore, in this study, we regulate the intensity value of each pixel by controlling the camera settings such as exposure time, gamma and gain values in order to calibrate the image obtained to the actual temperature values of a particular medium. In our approach, we use a color digital camera. The images obtained with a color digital camera can be separated on three different color-channels. Each channel corresponds to red, green, and blue color, moreover, each one has its own sensitivity. The differences in sensitivity allow us to obtain a range of temperature values for each color channel. Thus, high, medium and low sensitivity correspond to green, blue, and red color channel respectively. Therefore, by adding up the temperature contribution of each color channel we obtain a wide range of temperature values. Hence, the basic idea in our approach to measure temperature, using a schlieren system, is to relate the intensity level of each pixel in a schlieren image to the corresponding knife-edge position measured at the exit focal plane of the system. Our approach was applied to the measurement of instantaneous temperature fields of the air convection caused by a heated rectangular metal plate and a candle flame. We found that for the metal plate temperature measurements only the green and blue color-channels were required to sense the entire phenomena. On the other hand, for the candle case, the three color-channels were needed to obtain a complete measurement of temperature. In our study, the candle temperature was took as

  16. Parametrization of the average ionization and radiative cooling rates of carbon plasmas in a wide range of density and temperature

    OpenAIRE

    Gil de la Fe, Juan Miguel; Rodriguez Perez, Rafael; Florido, Ricardo; Garcia Rubiano, Jesus; Mendoza, M. A.; Nuez, A. de la; Espinosa, G.; Martel Escobar, Carlos; Mínguez Torres, Emilio

    2013-01-01

    In this work we present an analysis of the influence of the thermodynamic regime on the monochromatic emissivity, the radiative power loss and the radiative cooling rate for optically thin carbon plasmas over a wide range of electron temperature and density assuming steady state situations. Furthermore, we propose analytical expressions depending on the electron density and temperature for the average ionization and cooling rate based on polynomial fittings which are valid for the whole range...

  17. FORECASTING OF ESTIMATED PERFORMANCE OF CONCRETE WITH ORGANIC AND HYDRAULIC BINDING AGENTS WITHIN WIDE RANGE OF TEMPERATURE AND STRAIN RATE

    Directory of Open Access Journals (Sweden)

    V. A. Verenko

    2010-01-01

    Full Text Available A methodology  for determination of estimated performance of main road-building materials (asphalt concrete and сold recycled material within wide range of temperature and strain rate, is developed in the paper and it allows to obtain the whole spectrum of parameters required for calculation of a road pavement structure with minimum number of test results. This technique can be useful in designing material and pavement structure during its repair while using the method of cold in-place recycling because it enables significantly to reduce a number of laboratory tests. The methodology has been implemented as a computer program for its practical application.

  18. Efficient Wide Range Converters (EWiRaC): A new family of high efficient AC-DC Converters

    DEFF Research Database (Denmark)

    Petersen, Lars; Andersen, Michael Andreas E.

    2006-01-01

    suffers a major penalty in efficiency when used at the low end of the voltage range (90VAC) in a universal voltage range application (90-270VAC). This paper addresses this problem by suggesting a new family of converters that effectively reduces the apparent voltage range with a factor of 2 by changing...... the converter topology according to the input voltage. This new converter type has been named: efficient wide range converter (EWiRaC). The performance of the EWiRaC is experimental verified in a universal input range (90-270VAC) application with an output voltage of 185VDC capable of 500W output power. The EWi...

  19. FORWARD: A toolset for multiwavelength coronal magnetometry

    Directory of Open Access Journals (Sweden)

    Sarah eGibson

    2016-03-01

    Full Text Available Determining the 3D coronal magnetic field is a critical, but extremely difficult problem to solve. Since different types of multiwavelength coronal data probe different aspects of the coronal magnetic field, ideally these data should be used together to validate and constrain specifications of that field. Such a task requires the ability to create observable quantities at a range of wavelengths from a distribution of magnetic field and associated plasma -- i.e., to perform forward calculations. In this paper we describe the capabilities of the FORWARD SolarSoft IDL package, a uniquely comprehensive toolset for coronal magnetometry. FORWARD is a community resource that may be used both to synthesize a broad range of coronal observables, and to access and compare synthetic observables to existing data. It enables forward fitting of specific observations, and helps to build intuition into how the physical properties of coronal magnetic structures translate to observable properties. FORWARD can also be used to generate synthetic test beds from MHD simulations in order to facilitate the development of coronal magnetometric inversion methods, and to prepare for the analysis of future large solar telescope data.

  20. Can benthic foraminifera be used as bio-indicators of pollution in areas with a wide range of physicochemical variability?

    Science.gov (United States)

    Martins, Maria Virgínia Alves; Pinto, Anita Fernandes Souza; Frontalini, Fabrizio; da Fonseca, Maria Clara Machado; Terroso, Denise Lara; Laut, Lazaro Luiz Mattos; Zaaboub, Noureddine; da Conceição Rodrigues, Maria Antonieta; Rocha, Fernando

    2016-12-01

    The Ria de Aveiro, a lagoon located in the NW coast of Portugal, presents a wide range of changes to the natural hydrodynamical and physicochemical conditions induced for instance by works of port engineering and pollution. In order to evaluate the response of living benthic foraminifera to the fluctuations in physicochemical parameters and pollution (metals and TOC), eight sediment samples were collected from canals and salt pans within the Aveiro City, in four different sampling events. During the sampling events, salinity showed the most significant fluctuations among the physicochemical parameters with the maximum range of variation at Troncalhada and Santiago salt pans. Species such as Haynesina germanica, Trochammina inflata and Entzia macrescens were found inhabiting these hypersaline environments with the widest fluctuations of physicochemical parameters. In contrast, Ammonia tepida dominated zones with high concentrations of metals and organic matter and in lower salinity waters. Parameters related to benthic foraminiferal assemblages (i.e., diversity and evenness) were found to significantly decline in stations polluted by metals and characterized by higher TOC content. Foraminiferal density reduced significantly in locations with a wide range of physicochemical temporal variability. This work shows that, even under extreme conditions caused by highly variable physicochemical parameters, benthic foraminiferal assemblages might be used as valuable bioindicators of environmental stress.

  1. Preliminary assessment of the ecological risks to wide-ranging wildlife species on the Oak Ridge Reservation. 1996 update

    Energy Technology Data Exchange (ETDEWEB)

    Sample, B.E.; Hinzman, R.L.; Jackson, B.L.; Baron, L.

    1996-09-01

    More than approximately 50 years of operations, storage, and disposal of wastes generated by the three facilities on the Oak Ridge Reservation (ORR) (the Oak Ridge K-25 Site, Oak Ridge National Laboratory, and the Oak Ridge Y-12 Plant) has resulted in a mosaic of uncontaminated property and lands that are contaminated to varying degrees. This contaminated property includes source areas and the terrestrial and aquatic habitats down gradient from these source areas. Although the integrator OUs generally contain considerable habitat for biota, the source OUs provide little or no suitable habitat. Historically, ecological risk assessment at Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) sites has focused on species that may be definitively associated with a contaminated area or source OU. Endpoints considered in source OUs include plants, soil/litter invertebrates and processes, aquatic biota found in on-OU sediments and surface waters, and small herbivorous, omnivorous, and vermivorous (i.e., feeding on ground, litter, or soil invertebrates) wildlife. All of these endpoints have limited spatial distributions or home ranges such that numerous individuals or a distinct population can be expected to reside within the boundaries of the source OU. Most analyses are not adequate for large sites with multiple, spatially separated contaminated areas such as the ORR that provide habitat for wide-ranging wildlife species. This report is a preliminary response to a plan for assessing risks to wide-ranging species.

  2. Multifunctional photoacoustic signals detected by P(VDF/TrFE) film sensor with a wide range of frequency

    Science.gov (United States)

    Ishihara, M.; Hirasawa, T.; Tsujita, K.; Kitagaki, M.; Bansaku, I.; Fujita, M.; Kikuchi, M.

    2011-03-01

    Photoacoustics has been widely studied as a combined imaging modality of both optical and acoustical methods. The merits of the photoacoustic imaging are realizing the full potentials of pulsed laser-tissue interaction. As the photoacoustic waves can be induced at chromophores by pulsed lased irradiation through a thermoelastic process, it covers a wide range of frequency. In order to take advantages of the wide range frequency characteristics, we employed not PZT, but piezoelectronic copolymer film, P(VDF/TrFE) film, with various thickness ranging from 20 to 100 μm as photoacoustic transducers. Because blood vessels play a key role in homeostasis, we experimentally demonstrated blood vessels phantom using second harmonic generation of Q-switched Nd:YAG laser and Ti:sapphire nanosecond laser pulses through optical fiber transmission. The detected photoacoustic waveforms showed distinctive time-of-flight signals. The photoacoustic signals were sensitive to temperature, absorption coefficients of chromophores, and diameters of the phantom vessels. Hemoglobin oxygen saturation could be easily derived from the multi wavelength photoacoustic signals using differential optical absorption characteristics. These results proved the functional quantitative photoacoustic imaging using the signal characteristics. A multivariate photoacoustic imaging approach must be promising to convenient diagnosis.

  3. SEMICONDUCTOR INTEGRATED CIRCUITS: Design and implementation of a high precision and wide range adjustable LED drive controller

    Science.gov (United States)

    Guoding, Dai; Feng, Yu; Xuan, Wang; Weimin, Li

    2010-02-01

    This paper presents a novel high precision and wide range adjustable LED constant-current drive controller design. Compared with the traditional technique, the conventional mirror resistance is substituted by a MOSFET with fixed drain voltage, and a negative feedback amplifier is used to keep all mirror device voltages equal, so that the output current is precise and not affected by the load supply voltage. In addition, the electric property of the mirror MOSFET is optimized by a current subsection mirror (CSM) mechanism, thus ensuring a wide range of output current with high accuracy. A three-channel LED driver chip based on this project is designed and fabricated in the TSMC 0.6 μm BCD process with a die area of 1.1 × 0.7 mm2. Experimental results show that the proposed LED drive controller works well, and, as expected, the output current can be maintained from 5 to 60 mA. A relative current accuracy error of less than 1% and a maximal relative current matching error of 1.5% are successfully achieved.

  4. A compact wide-range spectrometer with image intensifier: unexpected advantages, new functions, and a variety of applications.

    Science.gov (United States)

    Protopopov, Vladimir

    2012-05-01

    Gated intensified spectrometers are very efficient instruments not only in time-resolved applications but also in all other fields were traditional non-gated and non-intensified devices are so popular today. This paper describes the design and performance of a simple, reliable, and relatively inexpensive wide-range gated intensified spectrometer that was conceived as a prototype for volume production. With 200-900 nm spectral range, 3 ns temporal resolution, variable optical gain up to 4000, repetition rate up to 200 kHz, spectral resolution 2 nm (0.9 nm with deconvolution), and affordable price, such a device may be useful for budget research laboratories working in the fields of cell biology, laser-induced breakdown spectroscopy, molecular kinetics, plasma diagnostics, materials characterization, combustion analysis, and forensic analysis.

  5. Parameter-free numerical method for modeling thermal convection in square cavities in a wide range of Rayleigh numbers

    Science.gov (United States)

    Goloviznin, V. M.; Korotkin, I. A.; Finogenov, S. A.

    2016-12-01

    Some numerical results for the two- and three-dimensional de Vahl Davis benchmark are presented. This benchmark describes thermal convection in a square (cubic) cavity with vertical heated walls in a wide range of Rayleigh numbers (104 to 1014), which covers both laminar and highly turbulent f lows. Turbulent f lows are usually described using a turbulence model with parameters that depend on the Rayleigh number and require adjustment. An alternative is Direct Numerical Simulation (DNS) methods, but they demand extremely large computational grids. Recently, there has been an increasing interest in DNS methods with an incomplete resolution, which, in some cases, are able to provide acceptable results without resolving Kolmogorov scales. On the basis of this approach, the so-called parameter-free computational techniques have been developed. These methods cover a wide range of Rayleigh numbers and allow computing various integral properties of heat transport on relatively coarse computational grids. In this paper, a new numerical method based on the CABARET scheme is proposed for solving the Navier-Stokes equations in the Boussinesq approximation. This technique does not involve a turbulence model or any tuning parameters and has a second-order approximation scheme in time and space on uniform and nonuniform grids with a minimal computational stencil. Testing the technique on the de Vahl Davis benchmark and a sequence of refined grids shows that the method yields integral heat f luxes with a high degree of accuracy for both laminar and highly turbulent f lows. For Rayleigh numbers up to 1014, a several percent accuracy is achieved on an extremely coarse grid consisting of 20 × 20 cells refined toward the boundary. No definite or comprehensive explanation of this computational phenomenon has been given. Cautious optimism is expressed regarding the perspectives of using the new method for thermal convection computations at low Prandtl numbers typical of liquid metals.

  6. Heavy reliance on carbohydrate across a wide range of exercise intensities during voluntary arm ergometry in persons with paraplegia.

    Science.gov (United States)

    Jacobs, Kevin A; Burns, Patricia; Kressler, Jochen; Nash, Mark S

    2013-09-01

    To describe and compare substrate oxidation and partitioning during voluntary arm ergometry in individuals with paraplegia and non-disabled individuals over a wide range of exercise intensities. Cross-sectional study. Clinical research facility. Ten apparently healthy, sedentary men with paraplegia and seven healthy, non-disabled subjects. Rest and continuous progressive voluntary arm ergometry between 30 and 80% of peak aerobic capacity (VO2peak). Total energy expenditure and whole body rates of fat and carbohydrate oxidation. A maximal whole body fat oxidation (WBFO) rate of 0.13 ± 0.07 g/minute was reached at 41 ± 9% VO2peak for subjects with paraplegia, although carbohydrate became the predominant fuel source during exercise exceeding an intensity of 30-40% VO2peak. Both the maximal WBFO rate (0.06 ± 0.04 g/minute) and the intensity at which it occurred (13 ± 3% VO2peak) were significantly lower for the non-disabled subjects than those with paraplegia. Sedentary individuals with paraplegia are more capable of oxidizing fat during voluntary arm ergometry than non-disabled individuals perhaps due to local adaptations of upper body skeletal muscle used for daily locomotion. However, carbohydrate is the predominant fuel source oxidized across a wide range of intensities during voluntary arm ergometry in those with paraplegia, while WBFO is limited and maximally achieved at low exercise intensities compared to that achieved by able-bodied individuals during leg ergometry. These findings may partially explain the diminished rates of fat loss imposed by acute bouts of physical activity in those with paraplegia.

  7. Multiwavelength pyrometry - An improved method

    Science.gov (United States)

    Hunter, G. B.; Allemand, C. D.; Eagar, T. W.

    1985-12-01

    Multiwavelength pyrometry measures simultaneously the temperature and emissivity of a thermal radiator by fitting a large number of radiation measurements to the Planck radiation law relation. It is assumed that a smooth function exists between the spectral emissitivity and the wavelength range of the radiation data. An error analysis shows that the relative errors in the temperature measurements are less than the random relative measurement errors of spectral radiance and that of the calculated spectral emissivity values. The effects of varying different parameters such as the wavelength range, the source temperature, and the number of data pairs on the accuracy of the temperature determinations are studied through computer simulations. It is shown that accuracy increases as the wavelength range is extended toward the peak in spectral radiance and as the number of measured data pairs increases. The experimental confirmation of this technique is presented, showing temperature measurements within 1 percent of the actual temperatures on a platinum surface within a temperature range of 1273 to 1724 K.

  8. Prototype Device For Multiwavelength Pyrometry

    Science.gov (United States)

    Hunter, Gordon B.; Allemand, Charly D.; Eagar, Thomas W.

    1986-11-01

    The Multichannel Infrared-Red Temperature Micro-Analyzer (MIRTMA) system is used to experimentally demonstrate the feasibility of a method of multiwavelength pyrometry using least-squares fitting analyses. The MIRTMA is a prototype instrument capable of monitoring temperatures above 1100 K with a spatial resolution of 100 um using spectral radiance measurements at approximately 200 wavelengths in a range of 0.6 to 0.8 um. Demonstrations of this equipment on a heated platinum strip source are described and discussed. The temperature measurements of these sources are generally within 5% of the actual temperature but can be within 1% using certain techniques. Capabilities and limitations of the method and the MIRTMA equipment are presented. The various calibrations used with the technique are also described, particularly with respect to corrections for the nonlinear response of the silicon intensified target (SIT) detector employed. Potential improvements to the instrument based on this work are presented, and it is concluded that the SIT detector should be replaced with a more suitable detector.

  9. Prototype device for multiwavelength pyrometry

    Energy Technology Data Exchange (ETDEWEB)

    Hunter, G.B.; Allemand, C.D.; Eagar, T.W.

    1986-11-01

    The Multichannel Infrared-Red Temperature Micro-Analyzer (MIRTMA) system is used to experimentally demonstrate the feasibility of a method of multiwavelength pyrometry using least-squares fitting analyses. The MIRTMA is a prototype instrument capable of monitoring temperatures above 1100 K with a spatial resolution of 100 ..mu..m using spectral radiance measurements at approximately 200 wavelengths in a range of 0.6 t 0.8 ..mu..m. Demonstrations of this equipment on a heated platinum strip source are described and discussed. The temperature measurements of these sources are generally within 5% of the actual temperature but can be within 1% using certain techniques. Capabilities and limitations of the method and the MIRTMA equipment are presented. The various calibrations used with the technique are also described, particularly with respect to corrections for the nonlinear response of the silicon intensified target (SIT) detector employed. Potential improvements to the instrument based on this work are presented, and it is concluded that the SIT detector should be replaced with a more suitable detector.

  10. A wide range of energy spin-filtering in a Rashba quantum ring using S-matrix method

    Science.gov (United States)

    Naeimi, Azadeh S.; Eslami, Leila; Esmaeilzadeh, Mahdi

    2013-01-01

    In this paper, spin-filtering properties of transmitted electrons through a quantum ring in the presence of Rashba spin-orbit interaction and magnetic flux are studied. To investigate the effects of coupling between the leads and ring on the spin-filtering, the S-matrix method is used. It is shown that by tuning the Rashba spin-orbit strength and the magnetic flux, the quantum ring can act as a perfect spin-filter with high efficiency. The spin-filtering can be changed from spin up to spin down and vice versa by changing the Rashba strength when the magnetic flux is held constant or by changing the magnetic flux when the Rashba strength is held constant. In addition, the effect of the angle between the leads on spin-filtering properties is taken into account and the angles at which the spin-filtering can occur are determined. The spin-filtering can take place in narrow ranges of electron energy for weak coupling, while for strong coupling it can take place in a wide range of electron energy.

  11. Impact of Wide-Ranging Nanoscale Chemistry on Band Structure at Cu(In, Ga)Se2 Grain Boundaries.

    Science.gov (United States)

    Stokes, Adam; Al-Jassim, Mowafak; Diercks, David; Clarke, Amy; Gorman, Brian

    2017-10-26

    The relative chemistry from grain interiors to grain boundaries help explain why grain boundaries may be beneficial, detrimental or benign towards device performance. 3D Nanoscale chemical analysis extracted from atom probe tomography (APT) (10's of parts-per-million chemical sensitivity and sub-nanometer spatial resolution) of twenty grain boundaries in a high-efficiency Cu(In, Ga)Se2 solar cell shows the matrix and alkali concentrations are wide-ranging. The concentration profiles are then related to band structure which provide a unique insight into grain boundary electrical performance. Fluctuating Cu, In and Ga concentrations result in a wide distribution of potential barriers at the valence band maximum (VBM) (-10 to -160 meV) and the conduction band minimum (CBM) (-20 to -70 meV). Furthermore, Na and K segregation is not correlated to hampering donors, (In, Ga)Cu and VSe, contrary to what has been previously reported. In addition, Na and K are predicted to be n-type dopants at grain boundaries. An overall band structure at grain boundaries is presented.

  12. Development of a novel monoclonal antibody with reactivity to a wide range of Venezuelan equine encephalitis virus strains

    Directory of Open Access Journals (Sweden)

    Phelps Amanda L

    2009-11-01

    Full Text Available Abstract Background There is currently a requirement for antiviral therapies capable of protecting against infection with Venezuelan equine encephalitis virus (VEEV, as a licensed vaccine is not available for general human use. Monoclonal antibodies are increasingly being developed as therapeutics and are potential treatments for VEEV as they have been shown to be protective in the mouse model of disease. However, to be truly effective, the antibody should recognise multiple strains of VEEV and broadly reactive monoclonal antibodies are rarely and only coincidentally isolated using classical hybridoma technology. Results In this work, methods were developed to reliably derive broadly reactive murine antibodies. A phage library was created that expressed single chain variable fragments (scFv isolated from mice immunised with multiple strains of VEEV. A broadly reactive scFv was identified and incorporated into a murine IgG2a framework. This novel antibody retained the broad reactivity exhibited by the scFv but did not possess virus neutralising activity. However, the antibody was still able to protect mice against VEEV disease induced by strain TrD when administered 24 h prior to challenge. Conclusion A monoclonal antibody possessing reactivity to a wide range of VEEV strains may be of benefit as a generic antiviral therapy. However, humanisation of the murine antibody will be required before it can be tested in humans. Crown Copyright © 2009

  13. Genetic diversity and differentiation in a wide ranging anadromous fish, American shad (Alosa sapidissima), is correlated with latitude.

    Science.gov (United States)

    Hasselman, Daniel J; Ricard, Daniel; Bentzen, Paul

    2013-03-01

    Studies that span entire species ranges can provide insight into the relative roles of historical contingency and contemporary factors that influence population structure and can reveal patterns of genetic variation that might otherwise go undetected. American shad is a wide ranging anadromous clupeid fish that exhibits variation in demographic histories and reproductive strategies (both semelparity and iteroparity) and provides a unique perspective on the evolutionary processes that govern the genetic architecture of anadromous fishes. Using 13 microsatellite loci, we examined the magnitude and spatial distribution of genetic variation among 33 populations across the species' range to (i) determine whether signals of historical demography persist among contemporary populations and (ii) assess the effect of different reproductive strategies on population structure. Patterns of genetic diversity and differentiation among populations varied widely and reflect the differential influences of historical demography, microevolutionary processes and anthropogenic factors across the species' range. Sequential reductions of diversity with latitude among formerly glaciated rivers are consistent with stepwise postglacial colonization and successive population founder events. Weak differentiation among U.S. iteroparous populations may be a consequence of human-mediated gene flow, while weak differentiation among semelparous populations probably reflects natural gene flow. Evidence for an effect of reproductive strategy on population structure suggests an important role for environmental variation and suggests that the factors that are responsible for shaping American shad life history patterns may also influence population genetic structure. © 2013 Blackwell Publishing Ltd.

  14. Parallel Mutations Result in a Wide Range of Cooperation and Community Consequences in a Two-Species Bacterial Consortium.

    Directory of Open Access Journals (Sweden)

    Sarah M Douglas

    Full Text Available Multi-species microbial communities play a critical role in human health, industry, and waste remediation. Recently, the evolution of synthetic consortia in the laboratory has enabled adaptation to be addressed in the context of interacting species. Using an engineered bacterial consortium, we repeatedly evolved cooperative genotypes and examined both the predictability of evolution and the phenotypes that determine community dynamics. Eight Salmonella enterica serovar Typhimurium strains evolved methionine excretion sufficient to support growth of an Escherichia coli methionine auxotroph, from whom they required excreted growth substrates. Non-synonymous mutations in metA, encoding homoserine trans-succinylase (HTS, were detected in each evolved S. enterica methionine cooperator and were shown to be necessary for cooperative consortia growth. Molecular modeling was used to predict that most of the non-synonymous mutations slightly increase the binding affinity for HTS homodimer formation. Despite this genetic parallelism and trend of increasing protein binding stability, these metA alleles gave rise to a wide range of phenotypic diversity in terms of individual versus group benefit. The cooperators with the highest methionine excretion permitted nearly two-fold faster consortia growth and supported the highest fraction of E. coli, yet also had the slowest individual growth rates compared to less cooperative strains. Thus, although the genetic basis of adaptation was quite similar across independent origins of cooperative phenotypes, quantitative measurements of metabolite production were required to predict either the individual-level growth consequences or how these propagate to community-level behavior.

  15. Parallel Mutations Result in a Wide Range of Cooperation and Community Consequences in a Two-Species Bacterial Consortium.

    Science.gov (United States)

    Douglas, Sarah M; Chubiz, Lon M; Harcombe, William R; Ytreberg, F Marty; Marx, Christopher J

    2016-01-01

    Multi-species microbial communities play a critical role in human health, industry, and waste remediation. Recently, the evolution of synthetic consortia in the laboratory has enabled adaptation to be addressed in the context of interacting species. Using an engineered bacterial consortium, we repeatedly evolved cooperative genotypes and examined both the predictability of evolution and the phenotypes that determine community dynamics. Eight Salmonella enterica serovar Typhimurium strains evolved methionine excretion sufficient to support growth of an Escherichia coli methionine auxotroph, from whom they required excreted growth substrates. Non-synonymous mutations in metA, encoding homoserine trans-succinylase (HTS), were detected in each evolved S. enterica methionine cooperator and were shown to be necessary for cooperative consortia growth. Molecular modeling was used to predict that most of the non-synonymous mutations slightly increase the binding affinity for HTS homodimer formation. Despite this genetic parallelism and trend of increasing protein binding stability, these metA alleles gave rise to a wide range of phenotypic diversity in terms of individual versus group benefit. The cooperators with the highest methionine excretion permitted nearly two-fold faster consortia growth and supported the highest fraction of E. coli, yet also had the slowest individual growth rates compared to less cooperative strains. Thus, although the genetic basis of adaptation was quite similar across independent origins of cooperative phenotypes, quantitative measurements of metabolite production were required to predict either the individual-level growth consequences or how these propagate to community-level behavior.

  16. Micro-Viscometer for Measuring Shear-Varying Blood Viscosity over a Wide-Ranging Shear Rate

    Science.gov (United States)

    Kim, Byung Jun; Lee, Seung Yeob; Jee, Solkeun; Atajanov, Arslan; Yang, Sung

    2017-01-01

    In this study, a micro-viscometer is developed for measuring shear-varying blood viscosity over a wide-ranging shear rate. The micro-viscometer consists of 10 microfluidic channel arrays, each of which has a different micro-channel width. The proposed design enables the retrieval of 10 different shear rates from a single flow rate, thereby enabling the measurement of shear-varying blood viscosity with a fixed flow rate condition. For this purpose, an optimal design that guarantees accurate viscosity measurement is selected from a parametric study. The functionality of the micro-viscometer is verified by both numerical and experimental studies. The proposed micro-viscometer shows 6.8% (numerical) and 5.3% (experimental) in relative error when compared to the result from a standard rotational viscometer. Moreover, a reliability test is performed by repeated measurement (N = 7), and the result shows 2.69 ± 2.19% for the mean relative error. Accurate viscosity measurements are performed on blood samples with variations in the hematocrit (35%, 45%, and 55%), which significantly influences blood viscosity. Since the blood viscosity correlated with various physical parameters of the blood, the micro-viscometer is anticipated to be a significant advancement for realization of blood on a chip. PMID:28632151

  17. Concurrent validity of the wide range assessment of visual motor abilities in typically developing children ages 4 to 11 years.

    Science.gov (United States)

    Obler, Doris R; Avi-Itzhak, Tamara

    2011-10-01

    Pediatric clinicians working with school-age children use the Wide Range Assessment of Visual Motor Abilities (WRAVMA) as a method for evaluating visual perception and motor skills in children despite limited information on concurrent validity. Whether it may be substituted for the Beery-Buktenica Developmental Test of Visual-Motor Integration (VMI) and has suitable estimates of concurrent validity were examined with a convenience sample of 91 typically developing children ages 4 to 11 years. No systematic concurrent validity between the WRAVMA and the VMI emerged. Only two subtests of the WRAVMA (Matching with Visual Perception, and Pegboard with Motor Coordination) gave scores statistically significantly correlated with those on the VMI, and these correlations were weak, accounting for very small amounts of the shared variance. As such, they have low clinical relevance. These findings do not provide evidence of concurrent validity to support the use of WRAVMA as an alternative method for the VMI for assessing children's visual perception and motor skills.

  18. An integrated geometric modelling framework for patient-specific computational haemodynamic study on wide-ranged vascular network.

    Science.gov (United States)

    Torii, Ryo; Oshima, Marie

    2012-01-01

    Patient-specific haemodynamic computations have been used as an effective tool in researches on cardiovascular disease associated with haemodynamics such as atherosclerosis and aneurysm. Recent development of computer resource has enabled 3D haemodynamic computations in wide-spread arterial network but there are still difficulties in modelling vascular geometry because of noise and limited resolution in medical images. In this paper, an integrated framework to model an arterial network tree for patient-specific computational haemodynamic study is developed. With this framework, 3D vascular geometry reconstruction of an arterial network and quantification of its geometric feature are aimed. The combination of 3D haemodynamic computation and vascular morphology quantification helps better understand the relationship between vascular morphology and haemodynamic force behind 'geometric risk factor' for cardiovascular diseases. The proposed method is applied to an intracranial arterial network to demonstrate its accuracy and effectiveness. The results are compared with the marching-cubes (MC) method. The comparison shows that the present modelling method can reconstruct a wide-ranged vascular network anatomically more accurate than the MC method, particularly in peripheral circulation where the image resolution is low in comparison to the vessel diameter, because of the recognition of an arterial network connectivity based on its centreline.

  19. Wide range of body composition measures are associated with cognitive function in community-dwelling older adults.

    Science.gov (United States)

    Won, Huiloo; Abdul Manaf, Zahara; Mat Ludin, Arimi Fitri; Shahar, Suzana

    2017-04-01

    Studies of the association between body composition, both body fat and body muscle, and cognitive function are rarely reported. The aim of the present study was to determine the association between a wide range of body composition measures with cognitive function in older adults. A total of 2322 Malaysian older adults aged 60 years and older were recruited using multistage random sampling in a population-based cross-sectional study. Out of 2322 older adults recruited, 2309 (48% men) completed assessments on cognitive function and body composition. Cognitive functions were assessed using the Malay version of the Mini-Mental State Examination, the Bahasa Malaysia version of Montreal Cognitive Assessment, Digit Span Test, Digit Symbol Test and Rey Auditory Verbal Learning Test. Body composition included body mass index, mid-upper arm circumference, waist circumference, calf circumference, waist-to-hip ratio, percentage body fat and skeletal muscle mass. The association between body composition and cognitive functions was analyzed using multiple linear regression. After adjustment for age, education years, hypertension, hypercholesterolemia, diabetes mellitus, depression, smoking status and alcohol consumption, we found that calf circumference appeared as a significant predictor for all cognitive tests among both men and women (P < 0.05), except for the Rey Auditory Verbal Learning Test. Waist-to-hip ratio was detected as a significant predictor for all cognitive tests among women (P < 0.05), but was only a significant predictor for the Bahasa Malaysia version of Montreal Cognitive Assessment among men (P < 0.05). These results suggest that there is a need to maintain muscle mass and lower adipose tissue among older adults for optimal cognitive function. Geriatr Gerontol Int 2017; 17: 554-560. © 2016 Japan Geriatrics Society.

  20. Identification and characterization of highly divergent simian foamy viruses in a wide range of new world primates from Brazil.

    Directory of Open Access Journals (Sweden)

    Cláudia P Muniz

    Full Text Available Foamy viruses naturally infect a wide range of mammals, including Old World (OWP and New World primates (NWP, which are collectively called simian foamy viruses (SFV. While NWP species in Central and South America are highly diverse, only SFV from captive marmoset, spider monkey, and squirrel monkey have been genetically characterized and the molecular epidemiology of SFV infection in NWPs remains unknown. We tested a large collection of genomic DNA (n = 332 comprising 14 genera of NWP species for the presence of SFV polymerase (pol sequences using generic PCR primers. Further molecular characterization of positive samples was carried out by LTR-gag and larger pol sequence analysis. We identified novel SFVs infecting nine NWP genera. Prevalence rates varied between 14-30% in different species for which at least 10 specimens were tested. High SFV genetic diversity among NWP up to 50% in LTR-gag and 40% in pol was revealed by intragenus and intrafamilial comparisons. Two different SFV strains infecting two captive yellow-breasted capuchins did not group in species-specific lineages but rather clustered with SFVs from marmoset and spider monkeys, indicating independent cross-species transmission events. We describe the first SFV epidemiology study of NWP, and the first evidence of SFV infection in wild NWPs. We also document a wide distribution of distinct SFVs in 14 NWP genera, including two novel co-speciating SFVs in capuchins and howler monkeys, suggestive of an ancient evolutionary history in NWPs for at least 28 million years. A high SFV genetic diversity was seen among NWP, yet these viruses seem able to jump between NWP species and even genera. Our results raise concerns for the risk of zoonotic transmission of NWP SFV to humans as these primates are regularly hunted for food or kept as pets in forest regions of South America.

  1. Behaviour and modelling of aluminium alloy AA6060 subjected to a wide range of strain rates and temperatures

    Directory of Open Access Journals (Sweden)

    Vilamosa Vincent

    2015-01-01

    Full Text Available The thermo-mechanical behaviour in tension of an as-cast and homogenized AA6060 alloy was investigated at a wide range of strains (the entire deformation process up to fracture, strain rates (0.01–750 s−1 and temperatures (20–350 ∘C. The tests at strain rates up to 1 s−1 were performed in a universal testing machine, while a split-Hopkinson tension bar (SHTB system was used for strain rates from 350 to 750 s−1. The samples were heated with an induction-based heating system. A typical feature of aluminium alloys at high temperatures is that necking occurs at a rather early stage of the deformation process. In order to determine the true stress-strain curve also after the onset of necking, all tests were instrumented with a digital camera. The experimental tests reveal that the AA6060 material has negligible strain-rate sensitivity (SRS for temperatures lower than 200 ∘C, while both yielding and work hardening exhibit a strong positive SRS at higher temperatures. The coupled strain-rate and temperature sensitivity is challenging to capture with most existing constitutive models. The paper presents an outline of a new semi-physical model that expresses the flow stress in terms of plastic strain, plastic strain rate and temperature. The parameters of the model were determined from the tests, and the stress-strain curves from the tests were compared with the predictions of the model. Good agreement was obtained over the entire strain rate and temperature range.

  2. Muscle coordination limits efficiency and power output of human limb movement under a wide range of mechanical demands

    Science.gov (United States)

    Wakeling, James M.

    2015-01-01

    This study investigated the influence of cycle frequency and workload on muscle coordination and the ensuing relationship with mechanical efficiency and power output of human limb movement. Eleven trained cyclists completed an array of cycle frequency (cadence)-power output conditions while excitation from 10 leg muscles and power output were recorded. Mechanical efficiency was maximized at increasing cadences for increasing power outputs and corresponded to muscle coordination and muscle fiber type recruitment that minimized both the total muscle excitation across all muscles and the ineffective pedal forces. Also, maximum efficiency was characterized by muscle coordination at the top and bottom of the pedal cycle and progressive excitation through the uniarticulate knee, hip, and ankle muscles. Inefficiencies were characterized by excessive excitation of biarticulate muscles and larger duty cycles. Power output and efficiency were limited by the duration of muscle excitation beyond a critical cadence (120–140 rpm), with larger duty cycles and disproportionate increases in muscle excitation suggesting deteriorating muscle coordination and limitations of the activation-deactivation capabilities. Most muscles displayed systematic phase shifts of the muscle excitation relative to the pedal cycle that were dependent on cadence and, to a lesser extent, power output. Phase shifts were different for each muscle, thereby altering their mechanical contribution to the pedaling action. This study shows that muscle coordination is a key determinant of mechanical efficiency and power output of limb movement across a wide range of mechanical demands and that the excitation and coordination of the muscles is limited at very high cycle frequencies. PMID:26445873

  3. Food Anticipatory Activity Behavior of Mice across a Wide Range of Circadian and Non-Circadian Intervals

    Science.gov (United States)

    Luby, Matthew D.; Hsu, Cynthia T.; Shuster, Scott A.; Gallardo, Christian M.; Mistlberger, Ralph E.; King, Oliver D.; Steele, Andrew D.

    2012-01-01

    When rodents are fed in a limited amount during the daytime, they rapidly redistribute some of their nocturnal activity to the time preceding the delivery of food. In rats, anticipation of a daily meal has been interpreted as a circadian rhythm controlled by a food-entrained oscillator (FEO) with circadian limits to entrainment. Lesion experiments place this FEO outside of the light-entrainable circadian pacemaker in the suprachiasmatic nucleus. Mice also anticipate a fixed daily meal, but circadian limits to entrainment and anticipation of more than 2 daily meals, have not been assessed. We used a video-based behavior recognition system to quantify food anticipatory activity in mice receiving 2, 3, or 6 daily meals at intervals of 12, 8, or 4-hours (h). Individual mice were able to anticipate as many as 4 of 6 daily meals, and anticipation persisted during meal omission tests. On the 6 meal schedule, pre-prandial activity and body temperature were poorly correlated, suggesting independent regulation. Mice showed a limited ability to anticipate an 18 h feeding schedule. Finally, mice showed concurrent circadian and sub-hourly anticipation when provided with 6 small meals, at 30 minute intervals, at a fixed time of day. These results indicate that mice can anticipate feeding opportunities at a fixed time of day across a wide range of intervals not previously associated with anticipatory behavior in studies of rats. The methods described here can be exploited to determine the extent to which timing of different intervals in mice relies on common or distinct neural and molecular mechanisms. PMID:22662260

  4. Researching Complex Heat, Air and Moisture Interactions for a Wide-Range of Building Envelope Systems and Environmental Loads

    Energy Technology Data Exchange (ETDEWEB)

    Karagiozis, A.N.

    2007-05-15

    This document serves as the final report documenting work completed by Oak Ridge National Laboratory (ORNL) and the Fraunhofer Institute in Building Physics (Holzkirchen, Germany) under an international CRADA No. 0575 with Fraunhofer Institute of Bauphysics of the Federal Republic of Germany for Researching Complex Heat, Air and Moisture Interactions for a Wide Range of Building Envelope Systems and Environmental Loads. This CRADA required a multi-faceted approach to building envelope research that included a moisture engineering approach by blending extensive material property analysis, laboratory system and sub-system thermal and moisture testing, and advanced moisture analysis prediction performance. The Participant's Institute for Building physics (IBP) and the Contractor's Buildings Technology Center (BTC) identified potential research projects and activities capable of accelerating and advancing the development of innovative, low energy and durable building envelope systems in diverse climates. This allowed a major leverage of the limited resources available to ORNL to execute the required Department of Energy (DOE) directives in the area of moisture engineering. A joint working group (ORNL and Fraunhofer IBP) was assembled and a research plan was executed from May 2000 to May 2005. A number of key deliverables were produced such as adoption of North American loading into the WUFI-software. in addition the ORNL Weather File Analyzer was created and this has been used to address environmental loading for a variety of US climates. At least 4 papers have been co-written with the CRADA partners, and a chapter in the ASTM Manual 40 on Moisture Analysis and Condensation Control. All deliverables and goals were met and exceeded making this collaboration a success to all parties involves.

  5. Muscle coordination limits efficiency and power output of human limb movement under a wide range of mechanical demands.

    Science.gov (United States)

    Blake, Ollie M; Wakeling, James M

    2015-12-01

    This study investigated the influence of cycle frequency and workload on muscle coordination and the ensuing relationship with mechanical efficiency and power output of human limb movement. Eleven trained cyclists completed an array of cycle frequency (cadence)-power output conditions while excitation from 10 leg muscles and power output were recorded. Mechanical efficiency was maximized at increasing cadences for increasing power outputs and corresponded to muscle coordination and muscle fiber type recruitment that minimized both the total muscle excitation across all muscles and the ineffective pedal forces. Also, maximum efficiency was characterized by muscle coordination at the top and bottom of the pedal cycle and progressive excitation through the uniarticulate knee, hip, and ankle muscles. Inefficiencies were characterized by excessive excitation of biarticulate muscles and larger duty cycles. Power output and efficiency were limited by the duration of muscle excitation beyond a critical cadence (120-140 rpm), with larger duty cycles and disproportionate increases in muscle excitation suggesting deteriorating muscle coordination and limitations of the activation-deactivation capabilities. Most muscles displayed systematic phase shifts of the muscle excitation relative to the pedal cycle that were dependent on cadence and, to a lesser extent, power output. Phase shifts were different for each muscle, thereby altering their mechanical contribution to the pedaling action. This study shows that muscle coordination is a key determinant of mechanical efficiency and power output of limb movement across a wide range of mechanical demands and that the excitation and coordination of the muscles is limited at very high cycle frequencies. Copyright © 2015 the American Physiological Society.

  6. Food anticipatory activity behavior of mice across a wide range of circadian and non-circadian intervals.

    Directory of Open Access Journals (Sweden)

    Matthew D Luby

    Full Text Available When rodents are fed in a limited amount during the daytime, they rapidly redistribute some of their nocturnal activity to the time preceding the delivery of food. In rats, anticipation of a daily meal has been interpreted as a circadian rhythm controlled by a food-entrained oscillator (FEO with circadian limits to entrainment. Lesion experiments place this FEO outside of the light-entrainable circadian pacemaker in the suprachiasmatic nucleus. Mice also anticipate a fixed daily meal, but circadian limits to entrainment and anticipation of more than 2 daily meals, have not been assessed. We used a video-based behavior recognition system to quantify food anticipatory activity in mice receiving 2, 3, or 6 daily meals at intervals of 12, 8, or 4-hours (h. Individual mice were able to anticipate as many as 4 of 6 daily meals, and anticipation persisted during meal omission tests. On the 6 meal schedule, pre-prandial activity and body temperature were poorly correlated, suggesting independent regulation. Mice showed a limited ability to anticipate an 18 h feeding schedule. Finally, mice showed concurrent circadian and sub-hourly anticipation when provided with 6 small meals, at 30 minute intervals, at a fixed time of day. These results indicate that mice can anticipate feeding opportunities at a fixed time of day across a wide range of intervals not previously associated with anticipatory behavior in studies of rats. The methods described here can be exploited to determine the extent to which timing of different intervals in mice relies on common or distinct neural and molecular mechanisms.

  7. Multiwavelength Polarization of Rotation-powered Pulsars

    Science.gov (United States)

    Harding, Alice K.; Kalapotharakos, Constantinos

    2017-05-01

    Polarization measurements provide strong constraints on models for emission from rotation-powered pulsars. We present multiwavelength polarization predictions showing that measurements over a range of frequencies can be particularly important for constraining the emission location, radiation mechanisms, and system geometry. The results assume a generic model for emission from the outer magnetosphere and current sheet in which optical to hard X-ray emission is produced by synchrotron radiation (SR) from electron-positron pairs and γ-ray emission is produced by curvature radiation (CR) or SR from accelerating primary electrons. The magnetic field structure of a force-free magnetosphere is assumed and the phase-resolved and phase-averaged polarization is calculated in the frame of an inertial observer. We find that large position angle (PA) swings and deep depolarization dips occur during the light-curve peaks in all energy bands. For synchrotron emission, the polarization characteristics are strongly dependent on photon emission radius with larger, nearly 180°, PA swings for emission outside the light cylinder (LC) as the line of sight crosses the current sheet. The phase-averaged polarization degree for SR is less that 10% and around 20% for emission starting inside and outside the LC, respectively, while the polarization degree for CR is much larger, up to 40%-60%. Observing a sharp increase in polarization degree and a change in PA at the transition between X-ray and γ-ray spectral components would indicate that CR is the γ-ray emission mechanism.

  8. Hunting for treasures among the Fermi unassociated sources: A multiwavelength approach

    Energy Technology Data Exchange (ETDEWEB)

    Acero, F.; Ojha, R. [ORAU/NASA Goddard Space Flight Center, Astrophysics Science Division, Code 661, Greenbelt, MD 20771 (United States); Donato, D.; Ferrara, E. [CRESST/NASA Goddard Space Flight Center, Astrophysics Science Division, Code 661, Greenbelt, MD 20771 (United States); Stevens, J. [CSIRO Astronomy and Space Science, Locked Bag 194, Narrabri NSW 2390 (Australia); Edwards, P. G. [CSIRO Astronomy and Space Science, P.O. Box 76, Epping NSW 1710 (Australia); Blanchard, J.; Lovell, J. E. J. [University of Tasmania School of Mathematics and Physics, Private Bag 37, Hobart TAS 7001 (Australia); Thompson, D. J., E-mail: fabio.f.acero@nasa.gov [NASA Goddard Space Flight Center, Astrophysics Science Division, Code 661, Greenbelt, MD 20771 (United States)

    2013-12-20

    The Fermi Gamma-Ray Space Telescope has been detecting a wealth of sources where the multiwavelength counterpart is either inconclusive or missing altogether. We present a combination of factors that can be used to identify multiwavelength counterparts to these Fermi unassociated sources. This approach was used to select and investigate seven bright, high-latitude unassociated sources with radio, UV, X-ray, and γ-ray observations. As a result, four of these sources are candidates to be active galactic nuclei, and one to be a pulsar, while two do not fit easily into these known categories of sources. The latter pair of extraordinary sources might reveal a new category subclass or a new type of γ-ray emitter. These results altogether demonstrate the power of a multiwavelength approach to illuminate the nature of unassociated Fermi sources.

  9. Touch the Invisible Sky: A multi-wavelength Braille book featuring NASA images

    Science.gov (United States)

    Steel, S.; Grice, N.; Daou, D.

    2008-06-01

    Multi-wavelength astronomy - the study of the Universe at wavelengths beyond the visible, has revolutionised our understanding and appreciation of the cosmos. Hubble, Chandra and Spitzer are examples of powerful, space-based telescopes that complement each other in their observations spanning the electromagnetic spectrum. While several Braille books on astronomical topics have been published, to this point, no printed material accessible to the sight disabled or Braille reading public has been available on the topic of multi-wavelength astronomy. Touch the Invisible Sky presents the first printed introduction to modern, multi-wavelength astronomy studies to the disabled sight community. On a more fundamental level, tactile images of a Universe that had, until recently, been invisible to all, sighted or non-sighted, is an important learning message on how science and technology broadens our senses and our understanding of the natural world.

  10. Nitrogen yield advantage from grass-legume mixtures is robust over a wide range of legume proportions and environmental conditions.

    Science.gov (United States)

    Suter, Matthias; Connolly, John; Finn, John A; Loges, Ralf; Kirwan, Laura; Sebastià, Maria-Teresa; Lüscher, Andreas

    2015-06-01

    Current challenges to global food security require sustainable intensification of agriculture through initiatives that include more efficient use of nitrogen (N), increased protein self-sufficiency through homegrown crops, and reduced N losses to the environment. Such challenges were addressed in a continental-scale field experiment conducted over 3 years, in which the amount of total nitrogen yield (Ntot ) and the gain of N yield in mixtures as compared to grass monocultures (Ngainmix ) was quantified from four-species grass-legume stands with greatly varying legume proportions. Stands consisted of monocultures and mixtures of two N2 -fixing legumes and two nonfixing grasses. The amount of Ntot of mixtures was significantly greater (P ≤ 0.05) than that of grass monocultures at the majority of evaluated sites in all 3 years. Ntot and thus Ngainmix increased with increasing legume proportion up to one-third of legumes. With higher legume percentages, Ntot and Ngainmix did not continue to increase. Thus, across sites and years, mixtures with one-third proportion of legumes attained ~95% of the maximum Ntot acquired by any stand and had 57% higher Ntot than grass monocultures. Realized legume proportion in stands and the relative N gain in mixture (Ngainmix /Ntot in mixture) were most severely impaired by minimum site temperature (R = 0.70, P = 0.003 for legume proportion; R = 0.64, P = 0.010 for Ngainmix /Ntot in mixture). Nevertheless, the relative N gain in mixture was not correlated to site productivity (P = 0.500), suggesting that, within climatic restrictions, balanced grass-legume mixtures can benefit from comparable relative gains in N yield across largely differing productivity levels. We conclude that the use of grass-legume mixtures can substantially contribute to resource-efficient agricultural grassland systems over a wide range of productivity levels, implying important savings in N fertilizers and thus greenhouse gas emissions and a

  11. Prediction of rumen degradability parameters of a wide range of forages and non-forages by NIRS.

    Science.gov (United States)

    Foskolos, A; Calsamiglia, S; Chrenková, M; Weisbjerg, M R; Albanell, E

    2015-07-01

    Kinetics of nutrient degradation in the rumen is an important component of feed evaluation systems for ruminants. The in situ technique is commonly used to obtain such dynamic parameters, but it requires cannulated animals and incubations last several days limiting its application in practice. On the other hand, feed industry relies strongly on NIRS to predict chemical composition of feeds and it has been used to predict nutrient degradability parameters. However, most of these studies were feedstuff specific, predicting degradability parameters of a particular feedstuff or category of feedstuffs, mainly forages or compound feeds and not grains and byproducts. Our objective was to evaluate the potential of NIRS to predict degradability parameters and effective degradation utilizing a wide range of feedstuffs commonly used in ruminant nutrition. A database of 809 feedstuffs was created. Feedstuffs were grouped as forages (FF; n=256), non-forages (NF; n=539) and of animal origin (n=14). In situ degradability data for dry matter (DM; n=665), CP (n=682) and NDF (n=100) were collected. Degradability was described in terms of washable fraction (a), slowly degradable fraction (b) and its rate of degradation (c). All samples were scanned from 1100 to 2500 nm using an NIRSystems 5000 scanning in reflectance mode. Calibrations were developed for all samples (ALL), FF and NF. Equations were validated with an external validation set of 20% of total samples. NIRS equations to predict the effective degradability and fractions a and b of DM, CP and NDF could be evaluated from being adequate for screening (r(2)>0.77; ratio of performance to deviation (RPD)=2.0 to 2.9) to suitable for quantitative purposes (r(2)>0.84; RPD=3.1 to 4.7), and some predictions were improved by group separation reducing the standard error of prediction. Similarly, the rate of degradation of CP (CP(c)) and DM (DM(c)) was predicted for screening purposes (RPD⩾2 and 2.5 for CP(c) and DM(c), respectively

  12. Modeling and Simulation of - and Silicon Germanium-Base Bipolar Transistors Operating at a Wide Range of Temperatures.

    Science.gov (United States)

    Shaheed, M. Reaz

    1995-01-01

    to provide consistently accurate values for base sheet resistance for both Si- and SiGe-base transistors over a wide range of temperatures. A model for plasma-induced bandgap narrowing suitable for implementation in a numerical simulator has been developed. The appropriate method of incorporating this model in a drift -diffusion solver is described. The importance of including this model for low temperature simulation is demonstrated. With these models in place, the enhanced simulator has been used for evaluating and designing the Si- and SiGe-base bipolar transistors. Silicon-germanium heterojunction bipolar transistors offer significant performance and cost advantages over conventional technologies in the production of integrated circuits for communications, computer and transportation applications. Their high frequency performance at low cost, will find widespread use in the currently exploding wireless communication market. However, the high performance SiGe-base transistors are prone to have a low common-emitter breakdown voltage. In this dissertation, a modification in the collector design is proposed for improving the breakdown voltage without sacrificing the high frequency performance. A comprehensive simulation study of p-n-p SiGe-base transistors has been performed. Different figures of merit such as drive current, current gain, cut -off frequency and Early voltage were compared between a graded germanium profile and an abrupt germanium profile. The differences in the performance level between the two profiles diminishes as the base width is scaled down.

  13. Multiwavelength Astronomy Modules for High School Students

    Science.gov (United States)

    Thomas, Christie; Brazas, J.; Lane, S.; York, D. G.

    2014-01-01

    The University of Chicago Multiwavelength Astronomy modules are web-based lessons covering the history, science, tools, and impact of astronomy across the wavebands, from gamma ray to infrared. Each waveband includes four lessons addressing one aspect of its development. The lessons are narrated by a historical docent or practicing scientist who contributed to a scientific discovery or instrument design significant to astronomical progress. The process of building each lesson began with an interview conducted with the scientist, or the consultation of a memoir or oral history transcript for historical docents. The source was then excerpted to develop a lesson and supplemented by archival material from the University of Chicago Library and other archives; NASA media; and participant contributed photographs, light curves, and spectra. Practicing educators also participated in the lesson development and evaluation. In July 2013, the University of Chicago sponsored 9 teachers and 15 students to participate in a STEM education program designed to engage participants as co-learners as they used the Multiwavelength Astronomy lessons in conjunction with talks given by the participating scientists. Teachers also practiced implementation of the resources with students and designed authentic research activities that make use of NASA mission data, which were undertaken as mini-research projects by student teams during the course of the program. This poster will introduce the Multiwavelength Astronomy web modules; highlight educator experiences in their use with high school audiences; and analyze the module development process, framing the benefits to and contributions of each of the stakeholders including practicing astronomers in research and space centers, high school science educators, high school students, University libraries and archives, and the NASA Science Mission Directorate. The development of these resources, and the summer professional development workshops were

  14. Wide range of metallic and organic contaminants in various tissues of the Antarctic prion, a planktonophagous seabird from the Southern Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Fromant, Aymeric [Centre d' Etudes Biologiques de Chizé, UMR 7372 CNRS—Université de La Rochelle, 79360 Villiers-en-Bois (France); Carravieri, Alice, E-mail: carravieri@cebc.cnrs.fr [Centre d' Etudes Biologiques de Chizé, UMR 7372 CNRS—Université de La Rochelle, 79360 Villiers-en-Bois (France); Littoral Environnement et Sociétés (LIENSs), UMR 7266 CNRS—Université de la Rochelle, 2 rue Olympe de Gouges, 17000 La Rochelle (France); Bustamante, Paco [Littoral Environnement et Sociétés (LIENSs), UMR 7266 CNRS—Université de la Rochelle, 2 rue Olympe de Gouges, 17000 La Rochelle (France); Labadie, Pierre; Budzinski, Hélène; Peluhet, Laurent [Université de Bordeaux, UMR 5805 EPOC (LPTC Research Group), Université Bordeaux, 351 Cours de la Libération, F 33405 Talence Cedex (France); Churlaud, Carine [Littoral Environnement et Sociétés (LIENSs), UMR 7266 CNRS—Université de la Rochelle, 2 rue Olympe de Gouges, 17000 La Rochelle (France); Chastel, Olivier; Cherel, Yves [Centre d' Etudes Biologiques de Chizé, UMR 7372 CNRS—Université de La Rochelle, 79360 Villiers-en-Bois (France)

    2016-02-15

    ABSTRACT: Trace elements (n = 14) and persistent organic pollutants (POPs, n = 30) were measured in blood, liver, kidney, muscle and feathers of 10 Antarctic prions (Pachyptila desolata) from Kerguelen Islands, southern Indian Ocean, in order to assess their concentrations, tissue distribution, and inter-tissue and inter-contaminant relationships. Liver, kidney and feathers presented the highest burdens of arsenic, cadmium and mercury, respectively. Concentrations of cadmium, copper, iron, and zinc correlated in liver and muscle, suggesting that uptake and pathways of metabolism and storage were similar for these elements. The major POPs were 4,4′-DDE, mirex, PCB-153 and PCB-138. The concentrations and tissue distribution patterns of environmental contaminants were overall in accordance with previous results in other seabirds. Conversely, some Antarctic prions showed surprisingly high concentrations of BDE-209. This compound has been rarely observed in seabirds before, and its presence in Antarctic prions could be due to the species feeding habits or to the ingestion of plastic debris. Overall, the study shows that relatively lower trophic level seabirds (zooplankton-eaters) breeding in the remote southern Indian Ocean are exposed to a wide range of environmental contaminants, in particular cadmium, selenium and some emerging-POPs, which merits further toxicological investigations. - Highlights: • Trace elements and POPs were measured in various tissues of 10 Antarctic prions. • Residue diversity was notable given the species' small size and low trophic position. • Cd, Se, BDE 183 and 209 showed noticeably high internal tissue concentrations. • Several POPs showed inter- and intra-tissue correlations, indicating co-exposure. • Blood was validated as a good bioindicator of internal tissue As and Hg levels.

  15. A kinetic and theoretical study of the borate catalysed reactions of hydrogen peroxide: the role of dioxaborirane as the catalytic intermediate for a wide range of substrates.

    Science.gov (United States)

    Deary, Michael E; Durrant, Marcus C; Davies, D Martin

    2013-01-14

    Our recent work has provided new insights into the equilibria and species that exist in aqueous solution at different pHs for the boric acid - hydrogen peroxide system, and the role of these species in oxidation reactions. Most recently, (M. C. Durrant, D. M. Davies and M. E. Deary, Org. Biomol. Chem., 2011, 9, 7249-7254), we have produced strong theoretical and experimental evidence for the existence of a previously unreported monocyclic three membered peroxide species, dioxaborirane, that is the likely catalytic species in borate mediated electrophilic reactions of hydrogen peroxide in alkaline solution. In the present paper, we extend our study of the borate-peroxide system to look at a wide range of substrates that include substituted dimethyl anilines, methyl-p-tolyl sulfoxide, halides, hydrogen sulfide anion, thiosulfate, thiocyanate, and hydrazine. The unusual selectivity-reactivity pattern of borate catalysed reactions compared with hydrogen peroxide and inorganic or organic peracids previously observed for the organic sulfides (D. M. Davies, M. E. Deary, K. Quill and R. A. Smith, Chem.-Eur. J., 2005, 11, 3552-3558) is also seen with substituted dimethyl aniline nucleophiles. This provides evidence that the pattern is not due to any latent electrophilic tendency of the organic sulfides and further supports dioxaborirane being the likely reactive intermediate, thus broadening the applicability of this catalytic system. Moreover, density functional theory calculations on our proposed mechanism involving dioxaborirane are consistent with the experimental results for these substrates. Results obtained at high concentrations of both borate and hydrogen peroxide require the inclusion the diperoxodiborate dianion in the kinetic analysis. A scheme detailing our current understanding of the borate-peroxide system is presented.

  16. The Novel Arrange & Average Algorithm for the Retrieval of Aerosol Properties from Multiwavelength Lidar Data

    Science.gov (United States)

    Chemyakin, E.; Mueller, D.; Burton, S. P.; Kolgotin, A.; Hostetler, C. A.; Ferrare, R. A.

    2014-12-01

    Aerosol particles affect the radiative energy balance in the atmosphere and thus influence regional and global climate through the direct and indirect radiative effect. Aerosols may result in net cooling or warming of the air, changes of the large-scale atmospheric circulation, cloud lifetime, and occurrence and intensity of precipitation. The presence and distribution of aerosols in space and time is highly inhomogeneous and variable. In addition, aerosol radiative forcing depends on the vertical distribution of aerosols. Regular observations of aerosol optical and physical properties over large temporal and spatial scales are needed for radiative impact studies to address the gaps in knowledge of the role of aerosols in climate change. In this context, light detection and ranging (lidar) instruments will play a crucial role as only these instruments provide information of aerosol properties with high vertical resolution. Here we present a novel, automated and unsupervised algorithm called the Arrange & Average algorithm that employs a look-up table for the purpose of retrieving the real and imaginary part of the complex refractive index (CRI), effective radius, and total number, surface-area, and volume concentrations of particle size distributions for a wide range of parameter space. The distinctive feature of our approach is that the CRI is treated like other retrieval parameters which significantly simplifies the whole numerical scheme. The algorithm is used for processing optical data acquired with different measurement configurations of multiwavelength high-spectral-resolution lidar or Raman lidar. The Arrange & Average algorithm is simple in its practical realization and flexible in the sense that it can be easily applied to various configurations of lidar instruments. We have conducted detailed numerical simulations and performance tests of the algorithm for 4 important lidar instrument configurations: "3 backscatter (β) + 2 extinction (α)" ("3β + 2

  17. Immunochemical characterization of and isolation of the gene for a Borrelia burgdorferi immunodominant 60-kilodalton antigen common to a wide range of bacteria

    DEFF Research Database (Denmark)

    Hansen, K; Bangsborg, Jette Marie; Fjordvang, H

    1988-01-01

    By crossed immunoelectrophoresis and Western blotting (immunoblotting), it was shown that Borrelia burgdorferi expresses the 60-kilodalton Common Antigen (CA) that is cross-reactive with an equivalent antigen in a wide range of remotely related bacteria. B. burgdorferi CA is strongly immunogenic....

  18. A Matrix-Based Structure for Vario-Scale Vector Representation over a Wide Range of Map Scales : The Case of River Network Data

    NARCIS (Netherlands)

    Huang, L.; Ai, Tinghua; van Oosterom, P.J.M.; Yan, Xiongfeng; Yang, Min

    2017-01-01

    The representation of vector data at variable scales has been widely applied in geographic information systems and map-based services. When the scale changes across a wide range, a complex generalization that involves multiple operations is required to transform the data. To present such complex

  19. Seasonality in cholera dynamics: A rainfall-driven model explains the wide range of patterns in endemic areas

    Science.gov (United States)

    Baracchini, Theo; King, Aaron A.; Bouma, Menno J.; Rodó, Xavier; Bertuzzo, Enrico; Pascual, Mercedes

    2017-10-01

    Seasonal patterns in cholera dynamics exhibit pronounced variability across geographical regions, showing single or multiple peaks at different times of the year. Although multiple hypotheses related to local climate variables have been proposed, an understanding of this seasonal variation remains incomplete. The historical Bengal region, which encompasses the full range of cholera's seasonality observed worldwide, provides a unique opportunity to gain insights on underlying environmental drivers. Here, we propose a mechanistic, rainfall-temperature driven, stochastic epidemiological model which explicitly accounts for the fluctuations of the aquatic reservoir, and analyze with this model the historical dataset of cholera mortality in the Bengal region. Parameters are inferred with a recently developed sequential Monte Carlo method for likelihood maximization in partially observed Markov processes. Results indicate that the hydrological regime is a major driver of the seasonal dynamics of cholera. Rainfall tends to buffer the propagation of the disease in wet regions due to the longer residence times of water in the environment and an associated dilution effect, whereas it enhances cholera resurgence in dry regions. Moreover, the dynamics of the environmental water reservoir determine whether the seasonality is unimodal or bimodal, as well as its phase relative to the monsoon. Thus, the full range of seasonal patterns can be explained based solely on the local variation of rainfall and temperature. Given the close connection between cholera seasonality and environmental conditions, a deeper understanding of the underlying mechanisms would allow the better management and planning of public health policies with respect to climate variability and climate change.

  20. The VLBA-BU-BLAZAR Multi-Wavelength Monitoring Program

    Directory of Open Access Journals (Sweden)

    Svetlana Jorstad

    2016-10-01

    Full Text Available We describe a multiwavelength program of monitoring of a sample of bright γ-ray blazars, which the Boston University (BU group has being carrying out since June 2007. The program includes monthly monitoring with the Very Long Baseline Array at 43 GHz, optical photometric and polarimetric observations, construction and analysis of UV and X-ray light curves obtained with the Rossi X-ray Timing Explorer (RXTE and Swift satellites, and construction and analysis of γ-ray light curves based on data provided by the Large Area Telescope of the Fermi Gamma-ray Space Telescope. We present general results about the kinematics of parsec-scale radio jets, as well as the connection between γ-ray outbursts and jet events.

  1. Application of a wide-range yeast vector (CoMed™ system to recombinant protein production in dimorphic Arxula adeninivorans, methylotrophic Hansenula polymorpha and other yeasts

    Directory of Open Access Journals (Sweden)

    Kunze Gotthard

    2006-11-01

    Full Text Available Abstract Background Yeasts provide attractive expression platforms in combining ease of genetic manipulation and fermentation of a microbial organism with the capability to secrete and to modify proteins according to a general eukaryotic scheme. However, early restriction to a single yeast platform can result in costly and time-consuming failures. It is therefore advisable to assess several selected systems in parallel for the capability to produce a particular protein in desired amounts and quality. A suitable vector must contain a targeting sequence, a promoter element and a selection marker that function in all selected organisms. These criteria are fulfilled by a wide-range integrative yeast expression vector (CoMed™ system based on A. adeninivorans- and H. polymorpha-derived elements that can be introduced in a modular way. Results The vector system and a selection of modular elements for vector design are presented. Individual single vector constructs were used to transform a range of yeast species. Various successful examples are described. A vector with a combination of an rDNA sequence for genomic targeting, the E. coli-derived hph gene for selection and the A. adeninivorans-derived TEF1 promoter for expression control of a GFP (green fluorescent protein gene was employed in a first example to transform eight different species including Hansenula polymorpha, Arxula adeninivorans and others. In a second example, a vector for the secretion of IL-6 was constructed, now using an A. adeninivorans-derived LEU2 gene for selection of recombinants in a range of auxotrophic hosts. In this example, differences in precursor processing were observed: only in A. adeninivorans processing of a MFα1/IL-6 fusion was performed in a faithful way. Conclusion rDNA targeting provides a tool to co-integrate up to 3 different expression plasmids by a single transformation step. Thus, a versatile system is at hand that allows a comparative assessment of newly

  2. A continuous current model of ultra-thin cylindrical surrounding-gate inversion-mode Si nanowire nMOSFETs considering a wide range of body doping concentration

    Science.gov (United States)

    Jin, Xiaoshi; Liu, Xi; Wu, Meile; Chuai, Rongyan; Lee, Jung-Hee; Lee, Jong-Ho

    2013-01-01

    Based on the approximated solution of Poisson's equation, we propose a continuous current model of ultra-thin fully depleted cylindrical surrounding-gate Si nanowire MOSFETs. It matches well with three-dimensional simulation results using SILVACO Atlas TCAD in a wide range (from intrinsic to high doping) of the body doping concentration without any empirical fitting parameters. It is valid for all the operation regions such as subthreshold, turn-on, linear and saturation.

  3. Wide Range Neutron Detector Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Current design concepts of nuclear reactors for space applications are well advanced in core configurations and architectural design. There is a need to determine...

  4. Wide Range Neutron Detector Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Current design concepts for space nuclear reactors are well advanced in core configurations and architectural design. There is need however to determine how such...

  5. Rapid variability of blazar 3C 279 during flaring states in 2013-2014 with joint FERMI-LAT, NuSTAR, swift, and ground-based multi-wavelength observations

    DEFF Research Database (Denmark)

    Hayashida, M.; Nalewajko, K.; Madejski, G. M.

    2015-01-01

    We report the results of a multiband observing campaign on the famous blazar 3C 279 conducted during a phase of increased activity from 2013 December to 2014 April, including first observations of it with NuSTAR. The γ-ray emission of the source measured by Fermi-LAT showed multiple distinct flar...

  6. Flow Patterns Transition Law of Oil-Water Two-Phase Flow under a Wide Range of Oil Phase Viscosity Condition

    OpenAIRE

    Wei Wang(College of William and Mary); Wei Cheng; Kai Li; Chen Lou; Jing Gong

    2013-01-01

    A systematic work on the prediction of flow patterns transition of the oil-water two-phase flows is carried out under a wide range of oil phase viscosities, where four main flow regimes are considered including stratified, dispersed, core-annular, and intermittent flow. For oil with a relatively low viscosity, VKH criterion is considered for the stability of stratified flow, and critical drop size model is distinguished for the transition of o/w and w/o dispersed flow. For oil with a high vis...

  7. The multiwavelength spectrum of NGC 3115: Hot accretion flow properties

    Science.gov (United States)

    Almeida, Ivan; Nemmen, Rodrigo; Wong, Ka-Wah; Wu, Qingwen; Irwin, Jimmy A.

    2018-01-01

    NGC 3115 is the nearest galaxy hosting a billion solar mass black hole and is also a low-luminosity active galactic nucleus (LLAGN). X-ray observations of this LLAGN are able to spatially resolve the hot gas within the sphere of gravitational influence of the supermassive black hole. These observations make NGC 3115 an important testbed for black hole accretion theory in galactic nuclei since they constrain the outer boundary conditions of the hot accretion flow. We present a compilation of the multiwavelength spectral energy distribution (SED) of the nucleus of NGC 3115 from radio to X-rays. We report the results from modeling the observed SED with radiatively inefficient accretion flow (RIAF) models. The radio emission can be well-explained by synchrotron emission from the RIAF without the need for contribution from a relativistic jet. We obtain a tight constraint on the RIAF density profile, ρ (r) ∝ r^{-0.73 _{-0.02} ^{+0.01}}, implying that mass-loss through subrelativistic outflows from the RIAF is significant. The lower frequency radio observation requires the synchrotron emission from a nonthermal electron population in the RIAF, similarly to Sgr A*.

  8. Solid State Multiwavelength LIDAR for Volcanic Ash Monitoring Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Physical Sciences Inc. proposes to develop a compact, multiwavelength LIDAR with polarization analysis capability that will be able to identify volcanic ash clouds...

  9. Acoustofluidics 22: multi-wavelength resonators, applications and considerations.

    Science.gov (United States)

    Hawkes, Jeremy J; Radel, Stefan

    2013-02-21

    One important niche for multi-wavelength resonators is the filtration of suspensions containing very high particle concentration. For some applications, multi-wavelength ultrasound enhanced sedimentation filters are second only to the centrifuge in efficiency but, unlike the centrifuge they are easily adapted for continuous flow. Multi-wavelength resonators are also an obvious consideration when half-wavelength chambers are too small for a specific application. Unfortunately the formula, bigger = higher-throughput, does not scale linearly. Here we describe the relationships between chamber size and throughput for acoustic, electrical, flow and thermal convection actions, allowing the user to define initial parameters for their specific applications with some confidence. We start with a review of some of the many forms of multi-wavelength particle manipulation systems.

  10. Hemicellulose block copolymers made from woods for wide-range directed self-assembly lithography enabling wider range of applicable patterning size

    Science.gov (United States)

    Morita, Kazuyo; Yamamoto, Kimiko

    2017-03-01

    Xylan, one of hemicellulose family, block copolymer was newly developed for wide-range directed self-assembly lithography (DSA). Xylan is higher hydrophilic material because of having many hydroxy groups in one molecule. It means that xylan block copolymer has a possibility of high-chi block copolymer. Generally, DSA is focused on microphase separation for smaller size with high-chi block copolymer and not well known for larger size. In this study, xylan block copolymer was confirmed enabling wider range of patterning size, from smaller size to larger size. The key of xylan block copolymer is a new molecular structure of block copolymer and sugar chain control technology. Sugar content is the important parameter for not only micro-phase separation property but also line edge roughness (LER) and defects. Based on the sugar control technology, wide-range (hp 8.3nm to 26nm L/S and CD 10nm to 51nm hole) DSA patterning was demonstrated. Additionally it was confirmed that xylan block copolymer is suitable for sequential infiltration synthesis (SIS) process.

  11. A multi-wavelength perspective on quasar fundamental properties

    Science.gov (United States)

    Runnoe, Jessie C.

    The goal of this thesis is to use a multi-wavelength perspective to advance the methods used to estimate fundamental properties of quasars. Based on a sample of the 85 most detailed quasar spectral energy distributions (SEDs) observed to date, this work focuses on calculating bolometric luminosity and black hole mass and understanding the role of orientation in determining these properties. Because quasars emit over a broad range of wavelengths, it can be challenging to determine bolometric luminosity and accretion rate (expressed as the Eddington ratio). I determine new bolometric corrections, taking particular care to address the difficulties that arise during the derivation process. Of the bolometric corrections in the infrared, optical, ultraviolet, and X-ray, those in the ultraviolet have the least dispersion and are preferred. X-ray bolometric corrections have very large dispersion and should be avoided. Black hole masses can be estimated for any quasar with a single-epoch spectrum using the single-epoch mass scaling relationships that are calibrated for a variety of emission lines, including Hbeta, Mg II lambda2798, and C IV lambda1549. I identify two sources of scatter, orientation and contamination from emission of non-virialized gas in the C IV line, between masses estimated from different emission lines and determine corrections for these effects. The application of both of these corrections reduces scatter between black hole masses estimated from different emission lines. Orientation plays an important role in determining the observed SEDs of quasars. In order to quantify this effect, I investigate quasar SEDs and their properties as a function of orientation. I find that infrared through X-ray monochromatic luminosities are orientation dependent, although the shape of the SED and estimates of the covering fraction of the circumnuclear dust are not. The sum of these investigations is to motivate the field to use a multi-wavelength approach and multi

  12. Soft x-ray free-electron laser imaging by LiF crystal and film detectors over a wide range of fluences.

    Science.gov (United States)

    Pikuz, Tatiana A; Faenov, Anatoly Ya; Fukuda, Yuji; Kando, Masaki; Bolton, Paul; Mitrofanov, Alexander; Vinogradov, Alexander V; Nagasono, Mitsuru; Ohashi, Haruhiko; Yabashi, Makina; Tono, Kensuke; Senba, Yasunori; Togashi, Tadashi; Ishikawa, Tetsuya

    2013-01-20

    LiF crystal and film detectors were used to measure the far-field fluence profile of a self-amplified spontaneous-emission free-electron laser beam and diffraction imaging with high spatial resolution. In these measurements the photoluminescence (PL) response of LiF crystal and film was compared over a wide range of soft x-ray fluences. It was found that the soft x-ray fluence dependences of LiF crystal and film differ. At low fluence, the LiF crystal shows higher PL response compared to LiF film, while this comparison is the opposite at higher fluence. Accurate measurement of LiF crystal and film PL response is important for precise characterization of the spatial, spectral, and coherence features of x-ray beams across the full profile and in localized areas. For such measurements, crucial LiF detector attributes are high spatial resolution and high dynamic range.

  13. Enhancing the critical current of a superconducting film in a wide range of magnetic fields with a conformal array of nanoscale holes

    Science.gov (United States)

    Wang, Y. L.; Latimer, M. L.; Xiao, Z. L.; Divan, R.; Ocola, L. E.; Crabtree, G. W.; Kwok, W. K.

    2013-06-01

    The maximum current (critical current) a type-II superconductor can transmit without energy loss is limited by the motion of the quantized magnetic flux penetrating into a superconductor. Introducing nanoscale holes into a superconducting film has been long pursued as a promising way to increase the critical current. So far the critical current enhancement was found to be mostly limited to low magnetic fields. Here we experimentally investigate the critical currents of superconducting films with a conformal array of nanoscale holes that have nonuniform density while preserving the local ordering. We find that the conformal array of nanoscale holes provides a more significant critical current enhancement at high magnetic fields. The better performance can be attributed to its arching effect that not only gives rise to the gradient in hole density for pinning vortices with a wide range of densities but also prevents vortex channeling occurring in samples with a regular lattice of holes.

  14. An Alternative Use of Olive Pomace as a Wide-Ranging Bioremediation Strategy to Adsorb and Recover Disperse Orange and Disperse Red Industrial Dyes from Wastewater

    Directory of Open Access Journals (Sweden)

    Vito Rizzi

    2017-09-01

    Full Text Available In this paper, industrial dyes, Disperse Red and Disperse Orange, were studied as model pollutants to show the excellent performance of olive pomace (OP in sequestering and recovering these dangerous dyes from wastewater. The nature of interactions involved between dyes and OP were inferred by changing several parameters: contact time, pomace dosage, pH and temperature values. Visible spectroscopy was mainly used to obtain the percentage of the removed dyes, while SEM (scanning electron microscopy, FTIR-ATR (Fourier transform infra-red spectroscopy in total attenuated reflectance, TG (thermo gravimetric and XPS (X-ray photoelectron spectroscopy analyses were used to carefully investigate the systems. The recovery of dyes was also obtained using glacial acetic acid, the auxiliary solvent used during the dyeing processes, enabling the recycling of both of the adsorbent material and dyes presenting a green and a wide-ranging strategic approach.

  15. MODELING THE EARLY MULTIWAVELENGTH EMISSION IN GRB 130427A

    Energy Technology Data Exchange (ETDEWEB)

    Fraija, N.; Lee, W. [Instituto de Astronomía, Universidad Nacional Autónoma de México, Apdo. Postal 70-264, Cd. Universitaria, DF 04510, México (Mexico); Veres, P., E-mail: nifraija@astro.unam.mx, E-mail: wlee@astro.unam.mx, E-mail: pv0004@uah.edu [Center for Space Plasma and Aeronomic Research (CSPAR), University of Alabama in Huntsville, Huntsville, AL 35899 (United States)

    2016-02-20

    One of the most powerful gamma-ray bursts, GRB 130427A was swiftly detected from GeV γ-rays to optical wavelengths. In the GeV band, the Large Area Telescope (LAT) on board the Fermi Gamma-Ray Space Telescope observed the highest-energy photon ever recorded of 95 GeV and a bright peak in the early phase followed by emission temporally extended for more than 20 hr. In the optical band, a bright flash with a magnitude of 7.03 ± 0.03 in the time interval from 9.31 to 19.31 s after the trigger was reported by RAPTOR in r band. We study the origin of the GeV γ-ray emission, using the multiwavelength observation detected in X-ray and optical bands. The origin of the temporally extended LAT, X-ray, and optical flux is naturally interpreted as synchrotron radiation, and the 95 GeV photon and the integral flux upper limits placed by the high-altitude water Cerenkov observatory are consistent with synchrotron self-Compton from an adiabatic forward shock propagating into the stellar wind of its progenitor. The extreme LAT peak and the bright optical flash are explained through synchrotron self-Compton and synchrotron emission from the reverse shock, respectively, when the ejecta evolves in the thick-shell regime and carries a significant magnetic field.

  16. Modeling the Early Multiwavelength Emission in GRB130427A

    Science.gov (United States)

    Fraija, N.; Lee, W.; Veres, P.

    2016-02-01

    One of the most powerful gamma-ray bursts, GRB 130427A was swiftly detected from GeV γ-rays to optical wavelengths. In the GeV band, the Large Area Telescope (LAT) on board the Fermi Gamma-Ray Space Telescope observed the highest-energy photon ever recorded of 95 GeV and a bright peak in the early phase followed by emission temporally extended for more than 20 hr. In the optical band, a bright flash with a magnitude of 7.03 ± 0.03 in the time interval from 9.31 to 19.31 s after the trigger was reported by RAPTOR in r band. We study the origin of the GeV γ-ray emission, using the multiwavelength observation detected in X-ray and optical bands. The origin of the temporally extended LAT, X-ray, and optical flux is naturally interpreted as synchrotron radiation, and the 95 GeV photon and the integral flux upper limits placed by the high-altitude water Cerenkov observatory are consistent with synchrotron self-Compton from an adiabatic forward shock propagating into the stellar wind of its progenitor. The extreme LAT peak and the bright optical flash are explained through synchrotron self-Compton and synchrotron emission from the reverse shock, respectively, when the ejecta evolves in the thick-shell regime and carries a significant magnetic field.

  17. Individual-level variation and higher-level interpretations of space use in wide-ranging species: An albatross case study of sampling effects

    Directory of Open Access Journals (Sweden)

    Sarah Elizabeth Gutowsky

    2015-11-01

    Full Text Available Marine ecologists and managers need to know the spatial extent of at-sea areas most frequented by the groups of wildlife they study or manage. Defining group-specific ranges and distributions (i.e. space use at the level of species, population, age-class, etc. can help to identify the source or severity of common or distinct threats among different at-risk groups. In biologging studies, this is accomplished by estimating the space use of a group based on a sample of tracked individuals. A major assumption of these studies is consistency in individual movements among members of a group. The implications of scaling up individual-level tracking data to infer higher-level spatial patterns for groups (i.e. size and extent of areas used, overlap or segregation among groups is not well documented for wide-ranging pelagic species with high potential for individual variation in space use. We present a case study exploring the effects of sampling (i.e. number and identity of individuals contributing to an analysis on defining group-specific space use with year-round multi-colony tracking data from two highly vagile species, Laysan (Phoebastria immutabilis and black-footed (P. nigripes albatrosses. The results clearly demonstrate that caution is warranted when defining space use for a specific species-colony-period group based on datasets of small, intermediate, or relatively large sample sizes (ranging from n=3-42 tracked individuals due to a high degree of individual-level variation in movements. Overall, we provide further support to the recommendation that biologging studies aiming to define higher-level patterns in space use exercise restraint in the scope of inference, particularly when pooled Kernel Density Estimation techniques are applied to small datasets for wide-ranging species. Transparent reporting in respect to the potential limitations of the data can in turn better inform both biological interpretations and science-based management

  18. Multiwavelength observations of unidentified high energy gamma ray sources

    Science.gov (United States)

    Halpern, Jules P.

    1993-10-01

    As was the case for COS B, the majority of high-energy (greater than 100 MeV) gamma-ray sources detected by the EGRET instrument on GRO are not immediately identifiable with cataloged objects at other wavelengths. These persistent gamma-ray sources are, next to the gamma-ray bursts, the least understood objects in the universe. Even a rudimentary understanding of their nature awaits identifications and follow-up work at other wavelengths to tell us what they are. The as yet unidentified sources are potentially the most interesting, since they may represent unrecognized new classes of astronomical objects, such as radio-quiet pulsars or new types of active galactic nuclei (AGN's). This two-year investigation is intended to support the analysis, correlation, and theoretical interpretation of data that we are obtaining at x ray, optical, and radio wavelengths in order to render the gamma-ray data interpretable. According to plan, in the first year concentration was on the identification and study of Geminga. The second year will be devoted to studies of similar unidentified gamma-ray sources which will become available in the first EGRET catalogs. The results obtained so far are presented in the two papers which are reproduced in the Appendix. In these papers, we discuss the pulse profiles of Geminga, the geometry and efficiency of the magnetospheric accelerator, the distance to Geminga, the implications for theories of polar cap heating, the effect of the magnetic field on the surface emission and environment of the neutron star, and possible interpretations of a radio-quiet Geminga. The implications of the other gamma-ray pulsars which were discovered to have high gamma-ray efficiency are also discussed, and the remaining unidentified COS B sources are attributed to a population of efficient gamma-ray sources, some of which may be radio quiet.

  19. [Primary age-related tauopathy (PART): a novel term to describe age-related tangle pathology encompassing a wide range from cognitively normal condition to senile dementia of the neurofibrillary tangle type].

    Science.gov (United States)

    Yamada, Masahito

    2016-03-01

    It has been reported that neurofibrillary tangles (NFTs) are commonly observed in older people, and that some of older individuals with dementia have a large amount of NFTs in the medial temporal lobe without amyloid(Aβ) plaques, which have been referred to as senile dementia of the NFT type (SD-NFT), tangle-predominant senile dementia (TPSD), or tangle-only dementia. In 2014, our international collaborative group proposed a new term, "primary age-related tauopathy(PART)", to describe such age-related tangle pathology, clinically encompassing a wide range from normal to cognitive impairment/ dementia (SD-NFT). This nomenclature would provide a conceptual foundation for future studies leading to development of clinical diagnosis for this condition.

  20. Novel Multiwavelength Microscopic Scanner for Mouse Imaging

    Directory of Open Access Journals (Sweden)

    Herlen Alencar

    2005-11-01

    Full Text Available Real-time in vivo imaging of molecular targets at (subcellular resolution is essential in better understanding complex biology. Confocal microscopy and multiphoton microscopy have been used in the past to achieve this goal, but their true capabilities have often been limited by bulky optics and difficult experimental set-ups requiring exteriorized organs. We describe here the development and validation of a unique nearinfrared laser scanning microscope system that uses novel optics with a millimeter footprint. Optimized for use in the far red and near-infrared ranges, the system allows an imaging depth that extends up to 500 Mm from a 1.3-mm-diameter stick objective, which is up to 2 cm in length. We show exceptionally high spatial, temporal, and multiwavelength resolutions of the system and show that it can be applied to virtually any internal organ through a keyhole surgical access. We demonstrate that, when combined with novel far red imaging probes, it is possible to image the cellular details of many organs and disease processes. The new optics, coupled with the use of near-infrared probes, should prove immensely valuable for in vivo cancer imaging.

  1. High-resolution topograms of fingerprints using multiwavelength digital holography

    Science.gov (United States)

    Abeywickrema, Ujitha; Banerjee, Partha; Kota, Akash; Swiontek, Stephen E.; Lakhtakia, Akhlesh

    2017-03-01

    Fingerprint analysis is a popular identification technique due to the uniqueness of fingerprints and the convenience of recording them. The quality of a latent fingerprint on a surface can depend on various conditions, such as the time of the day, temperature, and the composition of sweat. We first developed latent fingerprints on transparent and blackened glass slides by depositing 1000-nm-thick columnar thin films (CTFs) of chalcogenide glass of nominal composition Ge28Sb12Se60. Then, we used transmission-/reflection-mode multiwavelength digital holography to construct the topograms of CTF-developed fingerprints on transparent/blackened glass slides. The two wavelengths chosen were 514.5 and 457.9 nm, yielding a synthetic wavelength of 4.1624 μm, which is sufficient to resolve pores of depths 1 to 2 μm. Thus, our method can be used to measure the level-3 details that are usually difficult to observe with most other techniques applied to latent fingerprints.

  2. DMMW:. A tool for multi-wavelength Dark Matter searches

    Science.gov (United States)

    Gebauer, I.

    2012-08-01

    We present DMMW, a publicly available code, which computes the Dark Matter Multi-Wavelength emission spectrum for generic Dark Matter models. We briefly discusS a few applications to a variety of astrophysical systems within and beyond the Galaxy. In particular we constrain the averaged diffusion in the Cosmic Ray source regions of the Large Magellanic Cloud. DMMW calculates the secondary emission produced during the propagation of DM-induced leptons from the steady state distribution of these particles, as well as the prompt γ-ray emission produced directly during annihilation or decay. We believe it is extremely timely to introduce DMMW: a natural step needed to unveil the possibly exotic nature of some of Fermi unidentified sources will consist of follow-up multi-frequency observational campaigns. DMHW enables users to easily make theoretical predictions for the radio, UV, X-ray and soft γ-ray emissions associated with the relativistic electrons and positrons produced in Dark Matter annihilation or astrophysical sources. The DMMW code can be interfaced to spectral fitting packages relevant to various wave-lengths, e.g. XSPEC for X-rays, and the Fermi Science Tools. The code has been tested by comparison to numerical solutions obtained with the GALPROP code.

  3. Multiwavelength Studies of the Mouse Pulsar Wind Nebula

    Science.gov (United States)

    Klingler, Noel; Kargaltsev, Oleg; Pavlov, George G.; Ng, C.-Y.; Beniamini, Paz; O'Sullivan, Samantha

    2018-01-01

    PSR J1747-2958 is a young and energetic pulsar at an estimated distance of ~5 kpc. It is moving supersonically through the ISM and powers the famous Mouse pulsar wind nebula (PWN; G359.23-0.82): a tail spanning 45" in X-rays and 12' in radio. We discuss the results of our analysis of deep Chandra observations (as well as archival radio and IR data) of the Mouse PWN. We present a spatially-resolved spectral map of the PWN, which displays a photon index which varies strongly with distance from the pulsar over the 45" extent of the X-ray tail as the result of synchrotron cooling. We discuss the shape of the multiwavelength spectrum, the PWN physical properties (e.g., we infer a high magnetic field B~200 μG), and the connection between PWN morphology and radio/gamma-ray light curves which we use to constrain the viewing angle and identify structures in the PWN. We compare the Mouse pulsar with the population of other pulsars with measured (or inferred) velocities.

  4. Multi-wavelength follow-up of ANTARES neutrino alerts

    Science.gov (United States)

    Mathieu, Aurore

    2015-10-01

    Transient sources are often associated with the most violent phenomena in the Universe, where the acceleration of hadrons may occur. Such sources include gamma-ray bursts (GRBs), active galactic nuclei (AGN) or core-collapse supernovae (CCSNe), and are promising candidates for the production of high energy cosmic rays and neutrinos. The ANTARES telescope, located in the Mediterranean sea, aims at detecting these high energy neutrinos, which could reveal the presence of a cosmic ray accelerator. However, to enhance the sensitivity to transient sources, a method based on multi-wavelength follow-up of neutrino alerts has been developed within the ANTARES collaboration. This program, denoted as TAToO, triggers a network of robotic optical telescopes and the Swift-XRT with a delay of only a few seconds after a neutrino detection. The telescopes start an observation program of the corresponding region of the sky in order to detect a possible electromagnetic counterpart to the neutrino event. The work presented in this thesis covers the development and implementation of an optical image analysis pipeline, as well as the analysis of optical and X-ray data to search for fast transient sources, such as GRB afterglows, and slowly varying transient sources, such as CCSNe.

  5. Portable multiwavelength laser diode source for handheld photoacoustic devices

    Science.gov (United States)

    Canal, Celine; Laugustin, Arnaud; Kohl, Andreas; Rabot, Olivier

    2016-04-01

    The ageing population faces today an increase of chronic diseases such as rheumatism/arthritis, cancer and cardio vascular diseases for which appropriate treatments based on a diagnosis at an early-stage of the disease are required. Some imaging techniques are already available in order to get structural information. Within the non-invasive group, ultrasound images are common in these fields of medicine. However, there is a need for a point-of-care device for imaging smaller structures such as blood vessels that cannot be observed with purely ultrasound based devices. Photoacoustics proved to be an attractive candidate. This novel imaging technique combines pulsed laser light for excitation of tissues and an ultrasound transducer as a receptor. Introduction of this technique into the clinic requires to drastically shrink the size and cost of the expensive and bulky nanosecond lasers generally used for light emission. In that context, demonstration of ultra-short pulse emission with highly efficient laser diodes in the near-infrared range has been performed by Quantel, France. A multi-wavelength laser source as small as a hand emitted more than 1 mJ per wavelength with four different wavelengths available in pulses of about 90 ns. Such a laser source can be integrated into high sensitivity photoacoustic handheld systems due to their outstanding electrical-to-optical efficiency of about 25 %. Further work continues to decrease the pulse length as low as 40 ns while increasing the pulse energy to 2 mJ.

  6. Multi-wavelength study of the Seyfert 1 galaxy NGC 3783 with XMM-Newton

    CERN Document Server

    Blustin, A J; Behar, E; Kaastra, J S; Kahn, S M; Page, M J; Sako, M; Steenbrugge, K C

    2002-01-01

    We present the analysis of multi-wavelength XMM-Newton data from the Seyfert galaxy NGC 3783, including UV imaging, X-ray and UV lightcurves, the 0.2-10 keV X-ray continuum, the iron K-alpha emission line, and high-resolution spectroscopy and modelling of the soft X-ray warm absorber. The 0.2-10 keV spectral continuum can be well reproduced by a power-law at higher energies; we detect a prominent Fe K-alpha emission line, with both broad and narrow components, and a weaker emission line at 6.9 keV which is probably a combination of Fe K-beta and Fe XXVI. We interpret the significant deficit of counts in the soft X-ray region as being due to absorption by ionised gas in the line of sight. This is demonstrated by the large number of narrow absorption lines in the RGS spectrum from iron, oxygen, nitrogen, carbon, neon, argon, magnesium, silicon and sulphur. The wide range of iron states present in the spectrum enables us to deduce the ionisation structure of the absorbing medium. We find that our spectrum contai...

  7. The first multi-wavelength campaign of AXP 4U 0142+61 from radio to hard X-rays

    NARCIS (Netherlands)

    den Hartog, P.R.; Kuiper, L.; Hermsen, W.; Rea, N.; Durant, M.; Stappers, B.; Kaspi, V.M.; Dib, R.

    2007-01-01

    For the first time a quasi-simultaneous multi-wavelength campaign has been performed on an Anomalous X-ray Pulsar from the radio to the hard X-ray band. 4U 0142+61 was an INTEGRAL target for 1 Ms in July 2005. During these observations it was also observed in the X-ray band with Swift and RXTE, in

  8. Multi-wavelength characterization of carbonaceous aerosol

    Science.gov (United States)

    Massabò, Dario; Caponi, Lorenzo; Chiara Bove, Maria; Piazzalunga, Andrea; Valli, Gianluigi; Vecchi, Roberta; Prati, Paolo

    2014-05-01

    Carbonaceous aerosol is a major component of the urban PM. It mainly consists of organic carbon (OC) and elemental carbon (EC) although a minor fraction of carbonate carbon could be also present. Elemental carbon is mainly found in the finer PM fractions (PM2.5 and PM1) and it is strongly light absorbing. When determined by optical methods, it is usually called black carbon (BC). The two quantities, EC and BC, even if both related to the refractory components of carbonaceous aerosols, do not exactly define the same PM component (Bond and Bergstrom, 2006; and references therein). Moreover, another fraction of light-absorbing carbon exists which is not black and it is generally called brown carbon (Andreae and Gelencsér, 2006). We introduce a simple, fully automatic, multi-wavelength and non-destructive optical system, actually a Multi-Wavelength Absorbance Analyzer, MWAA, to measure off-line the light absorption in Particulate Matter (PM) collected on filters and hence to derive the black and brown carbon content in the PM This gives the opportunity to measure in the same sample the concentration of total PM by gravimetric analysis, black and brown carbon, metals by, for instance, X Ray Fluorescence, and finally ions by Ion Chromatography. Up to 16 samples can be analyzed in sequence and in an automatic and controlled way within a few hours. The filter absorbance measured by MWAA was successfully validated both against a MAAP, Multi Angle Absorption Photometer (Petzold and Schönlinner, 2004), and the polar photometer of the University of Milan. The measurement of sample absorbance at three wavelengths gives the possibility to apportion different sources of carbonaceous PM, for instance fossil fuels and wood combustion. This can be done following the so called "aethalometer method" (Sandradewi et al., 2008;) but with some significant upgrades that will be discussed together the results of field campaigns in rural and urban sites. Andreae, M.O, and Gelencsér, A

  9. Experimental-numerical evaluation of a new butterfly specimen for fracture characterisation of AHSS in a wide range of stress states

    Science.gov (United States)

    Peshekhodov, I.; Jiang, S.; Vucetic, M.; Bouguecha, A.; Berhens, B.-A.

    2016-11-01

    Results of an experimental-numerical evaluation of a new butterfly specimen for fracture characterisation of AHHS sheets in a wide range of stress states are presented. The test on the new butterfly specimen is performed in a uniaxial tensile machine and provides sufficient data for calibration of common fracture models. In the first part, results of a numerical specimen evaluation are presented, which was performed with a material model of a dual-phase steel DP600 taken from literature with plastic flow and fracture descriptions. In the second part, results of an experimental-numerical specimen evaluation are shown, which was conducted on another dual-phase steel DP600, which was available with a description of plastic flow only and whose fracture behaviour was characterised in the frame of this work. The overall performance of the new butterfly specimen at different load cases with regard to characterisation of the fracture behaviour of AHSS was investigated. The dependency of the fracture strain on the stress triaxiality and Lode angle as well as space resolution is quantified. A parametrised CrachFEM ductile shear fracture model and modified Mohr-Coloumb ductile shear fracture model are presented as a result of this quantification. The test procedure and results analysis are believed to contribute to current discussions on requirements to AHSS fracture characterisation.

  10. The dynamic compressive behavior and constitutive modeling of D1 railway wheel steel over a wide range of strain rates and temperatures

    Science.gov (United States)

    Jing, Lin; Su, Xingya; Zhao, Longmao

    The dynamic compressive behavior of D1 railway wheel steel at high strain rates was investigated using a split Hopkinson pressure bar (SHPB) apparatus. Three types of specimens, which were derived from the different positions (i.e., the rim, web and hub) of a railway wheel, were tested over a wide range of strain rates from 10-3 s-1 to 2.4 × 103 s-1 and temperatures from 213 K to 973 K. Influences of the strain rate and temperature on flow stress were discussed, and rate- and temperature-dependent constitutive relationships were assessed by the Cowper-Symonds model, Johnson-Cook model and a physically-based model, respectively. The experimental results show that the compressive true stress versus true strain response of D1 wheel steel is strain rate-dependent, and the strain hardening rate during the plastic flow stage decreases with the elevation of strain rate. Besides, the D1 wheel steel displays obvious temperature-dependence, and the third-type strain aging (3rd SA) is occurred at the temperature region of 673-973 K at a strain rate of ∼1500 s-1. Comparisons of experimental results with theoretical predictions indicate that the physically-based model has a better prediction capability for the 3rd SA characteristic of the tested D1 wheel steel.

  11. Design and evaluation of wide-range and low-power analog front-end enabling body-implanted devices to monitor charge injection properties

    Science.gov (United States)

    Ito, Keita; Uno, Shoma; Goto, Tatsuya; Takezawa, Yoshiki; Harashima, Takuya; Morikawa, Takumi; Nishino, Satoru; Kino, Hisashi; Kiyoyama, Koji; Tanaka, Tetsu

    2017-04-01

    For safe electrical stimulation with body-implanted devices, the degradation of stimulus electrodes must be considered because it causes the unexpected electrolysis of water and the destruction of tissues. To monitor the charge injection property (CIP) of stimulus electrodes while these devices are implanted, we have proposed a charge injection monitoring system (CIMS). CIMS can safely read out voltages produced by a biphasic current pulse to a stimulus electrode and CIP is calculated from waveforms of the acquired voltages. In this paper, we describe a wide-range and low-power analog front-end (AFE) for CIMS that has variable gain-frequency characteristics and low-power analog-to-digital (A/D) conversion to adjust to the degradation of stimulus electrodes. The designed AFE was fabricated with 0.18 µm CMOS technology and achieved a valuable gain of 20-60 dB, an upper cutoff frequency of 0.2-10 kHz, and low-power interleaving A/D conversion. In addition, we successfully measured the CIP of stimulus electrodes for body-implanted devices using CIMS.

  12. Wide-range screening of anti-inflammatory compounds in tomato using LC-MS and elucidating the mechanism of their functions.

    Directory of Open Access Journals (Sweden)

    Shinsuke Mohri

    Full Text Available Obesity-induced chronic inflammation is a key factor in type 2 diabetes. A vicious cycle involving pro-inflammatory mediators between adipocytes and macrophages is a common cause of chronic inflammation in the adipose tissue. Tomato is one of the most popular vegetables and is associated with a reduced risk of diabetes. However, the molecular mechanism underlying the effect of tomato on diabetes is unclear. In this study, we focused on anti-inflammatory compounds in tomato. We found that the extract of tomato reduced plasma glucose and inflammatory markers in mice. We screened anti-inflammatory fractions in tomato using lipopolysaccharide-stimulated RAW264.7 macrophages, and active compounds were estimated by liquid chromatography-mass spectrometry over a wide range. Surprisingly, a large number of compounds including oxylipin and coumarin derivatives were estimated as anti-inflammatory compounds. Especially, 9-oxo-octadecadienoic acid and daphnetin suppressed pro-inflammatory cytokines in RAW264.7 macrophages inhibiting mitogen-activated protein kinase phosphorylation and inhibitor of kappa B α protein degradation. These findings suggest that tomato containing diverse anti-inflammatory compounds ameliorates chronic inflammation in obese adipose tissue.

  13. Wide-range screening of anti-inflammatory compounds in tomato using LC-MS and elucidating the mechanism of their functions.

    Science.gov (United States)

    Mohri, Shinsuke; Takahashi, Haruya; Sakai, Maiko; Takahashi, Shingo; Waki, Naoko; Aizawa, Koichi; Suganuma, Hiroyuki; Ara, Takeshi; Matsumura, Yasuki; Shibata, Daisuke; Goto, Tsuyoshi; Kawada, Teruo

    2018-01-01

    Obesity-induced chronic inflammation is a key factor in type 2 diabetes. A vicious cycle involving pro-inflammatory mediators between adipocytes and macrophages is a common cause of chronic inflammation in the adipose tissue. Tomato is one of the most popular vegetables and is associated with a reduced risk of diabetes. However, the molecular mechanism underlying the effect of tomato on diabetes is unclear. In this study, we focused on anti-inflammatory compounds in tomato. We found that the extract of tomato reduced plasma glucose and inflammatory markers in mice. We screened anti-inflammatory fractions in tomato using lipopolysaccharide-stimulated RAW264.7 macrophages, and active compounds were estimated by liquid chromatography-mass spectrometry over a wide range. Surprisingly, a large number of compounds including oxylipin and coumarin derivatives were estimated as anti-inflammatory compounds. Especially, 9-oxo-octadecadienoic acid and daphnetin suppressed pro-inflammatory cytokines in RAW264.7 macrophages inhibiting mitogen-activated protein kinase phosphorylation and inhibitor of kappa B α protein degradation. These findings suggest that tomato containing diverse anti-inflammatory compounds ameliorates chronic inflammation in obese adipose tissue.

  14. Flow Patterns Transition Law of Oil-Water Two-Phase Flow under a Wide Range of Oil Phase Viscosity Condition

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2013-01-01

    Full Text Available A systematic work on the prediction of flow patterns transition of the oil-water two-phase flows is carried out under a wide range of oil phase viscosities, where four main flow regimes are considered including stratified, dispersed, core-annular, and intermittent flow. For oil with a relatively low viscosity, VKH criterion is considered for the stability of stratified flow, and critical drop size model is distinguished for the transition of o/w and w/o dispersed flow. For oil with a high viscousity, boundaries of core-annular flow are based on criteria proposed by Bannwart and Strazza et al. and neutral stability law ignoring that the velocity of the viscous phase is introduced for stratified flow. Comparisons between predictions and quantities of available data in both low and high viscosity oil-water flow from literatures show a good agreement. The framework provides extensive information about flow patterns transition of oil-water two-phase flow for industrial application.

  15. Development of advanced low NOx and wide range burner for pulverized coal combustion; Bifunsumiyo choteiNOx {center_dot} waidorenjibana no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Makino, Naoto; Kimoto, Masayoshi [Central Research Institure of Electric Power Inductry, Tokyo (Japan); Kiga, Takashi; Endo, Kiyohiko [Ishikawajima-Harima Heavy Industries Co., Ltd., Tokyo (Japan)

    1999-07-15

    Coal is becoming more and more important as an energy source for thermal power generation. In pulverized coal fired boilers, it is necessary to develop econometrically friendly technology for reducing NOx emission and unburned carbon in fly ash, and stable combustion technology at low flexible operation. An advanced low NOx burner (CI-{alpha} burner) has been developed, this burner is capable of reducing the NOx formation to about 30% lower than conventional burners at the same unburned carbon important to add the ability which the pulverized coal can be concentrated in the burner before ignition. In this paper, two coal particle concentrating methods are investigated for the CI-{alpha} burner. Each method can concentrate the pulverized coal particles greater than 1.5 times in the primary air nozzle. The new burner which combines this concentrating equipment with the CI-{alpha} burner offers stable combustion at 20%, on the same level as oil burners. This advanced low NOx and wide range burner (CI-{alpha} {center_dot} WR burner) has same the NOx and unburned carbon generation characteristics at the standard load as the CI-{alpha} burner and can reduce the unburned carbon in fly ash lower than the CI-{alpha} burner at low loads. (author)

  16. Finding the best combination of numerical schemes for 2-D SPH simulation of wedge water entry for a wide range of deadrise angles

    Directory of Open Access Journals (Sweden)

    Farsi Mohammad

    2014-09-01

    Full Text Available Main aim of this paper is to find the best combination of numerical schemes for 2-D SPH simulation of wedge water entry. Diffusion term is considered as laminar, turbulent, and artificial viscosity. Density filter that seriously affects the pressure distribution is investigated by adopting no filter, first order filter, and second order filter. Validation of the results indicates that turbulent model and first order density filter can lead to more reasonable solutions. This simulation was then conducted for wedge water entry with wide range of deadrise angles including 10 degrees, 20 degrees, 30 degrees, 45 degrees, 60 degrees and 81 degrees, with extreme deadrise angles of 10 degrees, 60 degrees and 81 degrees being considered. Comparison of SPH results with BEM solutions has displayed favorable agreement. In two particular cases where experimental data are available, the SPH results are shown to be closer to the experiments than BEM solution. While, accuracy of the obtained results for moderate deadrise angles is desirable, numerical findings for very small or very large deadrise angles are also very reasonable

  17. Wide-range antifungal antagonism of Paenibacillus ehimensis IB-X-b and its dependence on chitinase and beta-1,3-glucanase production.

    Science.gov (United States)

    Aktuganov, G; Melentjev, A; Galimzianova, N; Khalikova, E; Korpela, T; Susi, P

    2008-07-01

    Previously, we isolated a strain of Bacillus that had antifungal activity and produced lytic enzymes with fungicidal potential. In the present study, we identified the bacterium as Paenibacillus ehimensis and further explored its antifungal properties. In liquid co-cultivation assays, P. ehimensis IB-X-b decreased biomass production of several pathogenic fungi by 45%-75%. The inhibition was accompanied by degradation of fungal cell walls and alterations in hyphal morphology. Residual medium from cultures of P. ehimensis IB-X-b inhibited fungal growth, indicating the inhibitors were secreted into the medium. Of the 2 major lytic enzymes, chitinases were only induced by chitin-containing substrates, whereas beta-1,3-glucanase showed steady levels in all carbon sources. Both purified chitinase and beta-1,3-glucanase degraded cell walls of macerated fungal mycelia, whereas only the latter also degraded cell walls of intact mycelia. The results indicate synergism between the antifungal action mechanisms of these enzymes in which beta-1,3-glucanase is the initiator of the cell wall hydrolysis, whereas the degradation process is reinforced by chitinases. Paenibacillus ehimensis IB-X-b has pronounced antifungal activity with a wide range of fungi and has potential as a biological control agent against plant pathogenic fungi.

  18. Calculation of Friction Coefficient and Analysis of Fluid Flow in a Stepped Micro-Channel for Wide Range of Knudsen Number Using Lattice Boltzmann (MRT Method

    Directory of Open Access Journals (Sweden)

    Y. Bakhshan

    2015-01-01

    Full Text Available Micro scale gas flows has attracted significant research interest in the last two decades. In this research, the fluid flow of gases in the stepped micro-channel at a wide range of Knudsen number has been analyzed with using the Lattice Boltzmann (MRT method. In the model, a modified second-order slip boundary condition and a Bosanquet-type effective viscosity are used to consider the velocity slip at the boundaries and to cover the slip and transition regimes of flow and to gain an accurate simulation of rarefied gases. It includes the slip and transition regimes of flow. The flow specifications such as pressure loss, velocity profile, streamline and friction coefficient at different conditions have been presented. The results show good agreement with available experimental data. The calculation shows that the friction coefficient decreases with increasing the Knudsen number and stepping the micro-channel has an inverse effect on the friction coefficient. Furthermore, a new correlation is suggested for calculation of the friction coefficient in the stepped micro-channel as below: C_f Re  = 3.113+2.915/(1 +2 Kn+ 0.641 exp⁡(3.203/(1 + 2 Kn

  19. Calculation of friction coefficient and analysis of fluid flow in a stepped micro-channel for wide range of Knudsen number using Lattice Boltzmann (MRT) method

    Science.gov (United States)

    Bakhshan, Younes; Omidvar, Alireza

    2015-12-01

    Micro scale gas flows have attracted significant research interest in the last two decades. In this research, the fluid flow of gases in a stepped micro-channel has been conducted. Wide range of Knudsen number has been implemented using the Lattice Boltzmann (MRT) method in this study. A modified second-order slip boundary condition and a Bosanquet-type effective viscosity are used to consider the velocity slip at the boundaries and to cover the slip and transition regimes of flow to obtain an accurate simulation of rarefied gases. The flow specifications such as pressure loss, velocity profile, stream lines and friction coefficient at different conditions have been presented. The results show, good agreement with available experimental data. The calculation shows, that the friction coefficient decreases with increasing the Knudsen number and stepping the micro-channel has an inverse effect on the friction coefficient value. Furthermore, a new correlation is suggested for calculation of the friction coefficient in the stepped micro-channel flows as below;

  20. Multiwavelength Variability Analysis of 3C 279

    Directory of Open Access Journals (Sweden)

    Víctor M. Patiño-Álvarez

    2017-11-01

    Full Text Available We present a multifrequency analysis of the variability in the flat-spectrum radio quasar 3C 279 from 2008 to 2014. Our multiwavelength datasets range from 1 mm to gamma-rays, with additional optical polarimetry. Cross-correlation analysis shows a significant correlation between the UV continuum emission, the optical and NIR bands, at a delay consistent with zero, implying co-spatial emission regions. We also find a correlation between the UV continuum and the 1 mm data, which implies that the dominant process in producing the UV continuum is synchrotron emission. Based on the behavior of the gamma-ray light curve with respect to other bands, we identified three different activity periods. During period A we find a significant correlation at zero delay between the UV continuum and the gamma-rays, implying co-spatial emission regions which points toward synchrotron self-Compton as dominant gamma-ray emission mechanism. During period C we find a delay between the UV continuum and the gamma-rays, as well as a correlation at zero delay between X-rays and gamma-rays, both results implying that external inverse Compton is the dominant gamma-ray emission mechanism. During period B there are multiple flares in the bands from 1 mm to UV, however, none of these show a counterpart in the gamma-rays band. We propose that this is caused by an increase in the gamma-ray opacity due to electron-positron pair production.

  1. The dynamic compressive behavior and constitutive modeling of D1 railway wheel steel over a wide range of strain rates and temperatures

    Directory of Open Access Journals (Sweden)

    Lin Jing

    Full Text Available The dynamic compressive behavior of D1 railway wheel steel at high strain rates was investigated using a split Hopkinson pressure bar (SHPB apparatus. Three types of specimens, which were derived from the different positions (i.e., the rim, web and hub of a railway wheel, were tested over a wide range of strain rates from 10−3 s−1 to 2.4 × 103 s−1 and temperatures from 213 K to 973 K. Influences of the strain rate and temperature on flow stress were discussed, and rate- and temperature-dependent constitutive relationships were assessed by the Cowper-Symonds model, Johnson-Cook model and a physically-based model, respectively. The experimental results show that the compressive true stress versus true strain response of D1 wheel steel is strain rate-dependent, and the strain hardening rate during the plastic flow stage decreases with the elevation of strain rate. Besides, the D1 wheel steel displays obvious temperature-dependence, and the third-type strain aging (3rd SA is occurred at the temperature region of 673–973 K at a strain rate of ∼1500 s−1. Comparisons of experimental results with theoretical predictions indicate that the physically-based model has a better prediction capability for the 3rd SA characteristic of the tested D1 wheel steel. Keywords: Railway wheel steel, SHPB, Strain rate, Temperature effect, Strain aging

  2. Effects of a wide range of dietary nicotinamide riboside (NR) concentrations on metabolic flexibility and white adipose tissue (WAT) of mice fed a mildly obesogenic diet.

    Science.gov (United States)

    Shi, Wenbiao; Hegeman, Maria A; van Dartel, Dorien A M; Tang, Jing; Suarez, Manuel; Swarts, Hans; van der Hee, Bart; Arola, Lluis; Keijer, Jaap

    2017-08-01

    Metabolic flexibility is the ability to switch metabolism between carbohydrate oxidation (CHO) and fatty acid oxidation (FAO) and is a biomarker for metabolic health. The effect on metabolic health of nicotinamide riboside (NR) as an exclusive source of vitamin B3 is unknown and is examined here for a wide range of NR. Nine-week-old male C57BL/6JRcc mice received a semi-purified mildly obesogenic (40 en% fat) diet containing 0.14% L-tryptophan and either 5, 15, 30, 180, or 900 mg NR per kg diet for 15 weeks. Body composition and metabolic parameters were analyzed. Metabolic flexibility was measured using indirect calorimetry. Gene expression in epididymal white adipose tissue (eWAT) was measured using qRT-PCR . The maximum delta respiratory exchange ratio when switching from CHO to FAO (maxΔRER CHO1→FAO ) and when switching from FAO to CHO (maxΔRER FAO→CHO2 ) were largest in 30 mg NR per kg diet (30NR). In eWAT, the gene expression of Pparγ, a master regulator of adipogenesis, and of Sod2 and Prdx3, two antioxidant genes, were significantly upregulated in 30NR compared to 5NR. 30NR is most beneficial for metabolic health, in terms of metabolic flexibility and eWAT gene expression, of mice on an obesogenic diet. © 2017 The Authors. Molecular Nutrition & Food Research published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Solubility Measurements and Predictions of Gypsum, Anhydrite, and Calcite Over Wide Ranges of Temperature, Pressure, and Ionic Strength with Mixed Electrolytes

    Science.gov (United States)

    Dai, Zhaoyi; Kan, Amy T.; Shi, Wei; Zhang, Nan; Zhang, Fangfu; Yan, Fei; Bhandari, Narayan; Zhang, Zhang; Liu, Ya; Ruan, Gedeng; Tomson, Mason B.

    2017-02-01

    Today's oil and gas production from deep reservoirs permits exploitation of more oil and gas reserves but increases risks due to conditions of high temperature and high pressure. Predicting mineral solubility under such extreme conditions is critical for mitigating scaling risks, a common and costly problem. Solubility predictions use solubility products and activity coefficients, commonly from Pitzer theory virial coefficients. However, inaccurate activity coefficients and solubility data have limited accurate mineral solubility predictions and applications of the Pitzer theory. This study measured gypsum solubility under its stable phase conditions up to 1400 bar; it also confirmed the anhydrite solubility reported in the literature. Using a novel method, the virial coefficients for Ca2+ and {{SO}}4^{2 - } (i.e., β_{{{{CaSO}}4 }}^{(0)} ,β_{{{{CaSO}}4 }}^{(2)} ,C_{{{{CaSO}}4 }}^{φ }) were calculated over wide ranges of temperature and pressure (0-250 °C and 1-1400 bar). The determination of this set of virial coefficients widely extends the applicable temperature and pressure ranges of the Pitzer theory in Ca2+ and SO 4 2- systems. These coefficients can be applied to improve the prediction of calcite solubility in the presence of high concentrations of Ca2+ and SO 4 2- ions. These new virial coefficients can also be used to predict the solubilities of gypsum and anhydrite accurately. Moreover, based on the derived β_{{{{CaSO}}4 }}^{(2)} values in this study, the association constants of {{CaSO}}4^{( 0 )} at 1 bar and 25 °C can be estimated by K_{{assoc}} = - 2β_{{{{CaSO}}4 }}^{(2)}. These values match very well with those reported in the literature based on other methods.

  4. Is a single bioelectrical impedance equation valid for children of wide ranges of age, pubertal status and nutritional status? Evidence from the 4-component model.

    Science.gov (United States)

    Montagnese, C; Williams, J E; Haroun, D; Siervo, M; Fewtrell, M S; Wells, J C K

    2013-01-01

    Bioelectrical impedance analysis (BIA) is widely used to predict body composition in paediatric research and clinical practice. Many equations have been published, but provide inconsistent predictions. To test whether a single equation for lean mass (LM) estimation from BIA is appropriate across wide ranges of age, pubertal status and nutritional status, by testing whether specific groups differ in the slope or intercept of the equation. In 547 healthy individuals aged 4-24 years (240 males), we collected data on body mass (BM) and height (HT), and lean mass (LM) using the 4-component model. Impedance (Z) was measured using TANITA BC418MA instrumentation. LM was regressed on HT(2)/Z. Multiple regression analysis was conducted to investigate whether groups based on gender, age, pubertal status or nutritional status differed in the association of LM with HT(2)/Z. BM ranged from 5 to 128 kg. HT(2)/Z was a strong predictor of LM (r (2)=0.953, s.e.e.=2.9 kg). There was little evidence of a sex difference in this relationship, however, children aged 4-7 years and 16-19 years differed significantly from other age groups in regression slopes and intercepts. Similar variability was encountered for pubertal stage, but not for nutritional status. No single BIA equation applies across the age range 4-24 years. At certain ages or pubertal stages, the slope and intercept of the equation relating LM to HT(2)/Z alters. Failure to address such age effects is likely to result in poor accuracy of BIA (errors of several kg) for longitudinal studies of change in body composition.

  5. Comparability of Icare Pro Rebound Tonometer with Goldmann Applanation and Noncontact Tonometer in a Wide Range of Intraocular Pressure and Central Corneal Thickness.

    Science.gov (United States)

    Tamçelik, Nevbahar; Atalay, Eray; Cicik, Erdogan; Özkök, Ahmet

    2015-01-01

    To evaluate the agreement between the reading values of the Goldmann applanation tonometer (GAT), Icare Pro rebound tonometer (IRT) and noncontact tonometer (NCT) in glaucoma patients. This cross-sectional study comprised 292 eyes of 292 patients selected from a glaucoma outpatient clinic. The intraocular pressure (IOP) was measured sequentially, at a 10-min interval each, in the following order: NCT, IRT and GAT. The central corneal thickness (CCT) was measured using Pentacam HR before the IOP measurements. The mean IOPs measured by the GAT, NCT and IRT were 20.17 ± 6.73 mm Hg (range: 4-48), 19.77 ± 6.88 mm Hg (range: 3-46) and 19.30 ± 5.15 mm Hg (range: 7.30-44.5), respectively. The correlation coefficients of the GAT and IRT, NCT and IRT, and GAT and NCT measurements were r(2) = 0.673, r(2) = 0.663 and r(2) = 0.938 (all p measured IOPs, whereas it underestimates in high GAT-measured IOPs. The measurements of all 3 devices were also correlated with the CCT at a statistically significant level (GAT: r(2) = 0.063, NCT: r(2) = 0.063, IRT: r(2) = 0.058). The agreement between the IRT and GAT measurements is higher in the IOP range of 9-22 mm Hg, whereas significant discrepancies occur as the IOP deviates from normal values. The variability of the IRT and GAT measurements over a wide range of CCT is minimal. © 2015 S. Karger AG, Basel.

  6. Lack of parental rule-setting on eating is associated with a wide range of adolescent unhealthy eating behaviour both for boys and girls.

    Science.gov (United States)

    Holubcikova, Jana; Kolarcik, Peter; Madarasova Geckova, Andrea; van Dijk, Jitse P; Reijneveld, Sijmen A

    2016-04-27

    Unhealthy eating habits in adolescence lead to a wide variety of health problems and disorders. The aim of this study was to assess the prevalence of absence of parental rules on eating and unhealthy eating behaviour and to explore the relationships between parental rules on eating and a wide range of unhealthy eating habits of boys and girls. We also explored the association of sociodemographic characteristics such as gender, family affluence or parental education with eating related parental rules and eating habits of adolescents. The data on 2765 adolescents aged 13-15 years (mean age: 14.4; 50.7 % boys) from the Slovak part of the Health Behaviour in School-Aged Children (HBSC) study 2014 were assessed. The associations between eating-related parental rules and unhealthy eating patterns using logistic regression were assessed using logistic regression. Unhealthy eating habits occurred frequently among adolescents (range: 18.0 % reported skipping breakfast during weekends vs. 75.8 % for low vegetables intake). Of all adolescents, 20.5 % reported a lack of any parental rules on eating (breakfast not mandatory, meal in front of TV allowed, no rules about sweets and soft drinks). These adolescents were more likely to eat unhealthily, i.e. to skip breakfast on weekdays (odds ratio/95 % confidence interval: 5.33/4.15-6.84) and on weekends (2.66/2.12-3.34), to report low consumption of fruits (1.63/1.30-2.04) and vegetables (1.32/1.04-1.68), and the frequent consumption of sweets (1.59/1.30-1.94), soft drinks (1.93/1.56-2.38) and energy drinks (2.15/1.72-2.70). Parental rule-setting on eating is associated with eating behaviours of adolescents. Further research is needed to disentangle causality in this relationship. If causal, parents may be targeted to modify the eating habits of adolescents.

  7. Determination of Germination Response to Temperature and Water Potential for a Wide Range of Cover Crop Species and Related Functional Groups.

    Science.gov (United States)

    Tribouillois, Hélène; Dürr, Carolyne; Demilly, Didier; Wagner, Marie-Hélène; Justes, Eric

    2016-01-01

    A wide range of species can be sown as cover crops during fallow periods to provide various ecosystem services. Plant establishment is a key stage, especially when sowing occurs in summer with high soil temperatures and low water availability. The aim of this study was to determine the response of germination to temperature and water potential for diverse cover crop species. Based on these characteristics, we developed contrasting functional groups that group species with the same germination ability, which may be useful to adapt species choice to climatic sowing conditions. Germination of 36 different species from six botanical families was measured in the laboratory at eight temperatures ranging from 4.5-43°C and at four water potentials. Final germination percentages, germination rate, cardinal temperatures, base temperature and base water potential were calculated for each species. Optimal temperatures varied from 21.3-37.2°C, maximum temperatures at which the species could germinate varied from 27.7-43.0°C and base water potentials varied from -0.1 to -2.6 MPa. Most cover crops were adapted to summer sowing with a relatively high mean optimal temperature for germination, but some Fabaceae species were more sensitive to high temperatures. Species mainly from Poaceae and Brassicaceae were the most resistant to water deficit and germinated under a low base water potential. Species were classified, independent of family, according to their ability to germinate under a range of temperatures and according to their base water potential in order to group species by functional germination groups. These groups may help in choosing the most adapted cover crop species to sow based on climatic conditions in order to favor plant establishment and the services provided by cover crops during fallow periods. Our data can also be useful as germination parameters in crop models to simulate the emergence of cover crops under different pedoclimatic conditions and crop

  8. Not to put too fine a point on it - does increasing precision of geographic referencing improve species distribution models for a wide-ranging migratory bat?

    Science.gov (United States)

    Hayes, Mark A.; Ozenberger, Katharine; Cryan, Paul M.; Wunder, Michael B.

    2015-01-01

    Bat specimens held in natural history museum collections can provide insights into the distribution of species. However, there are several important sources of spatial error associated with natural history specimens that may influence the analysis and mapping of bat species distributions. We analyzed the importance of geographic referencing and error correction in species distribution modeling (SDM) using occurrence records of hoary bats (Lasiurus cinereus). This species is known to migrate long distances and is a species of increasing concern due to fatalities documented at wind energy facilities in North America. We used 3,215 museum occurrence records collected from 1950–2000 for hoary bats in North America. We compared SDM performance using five approaches: generalized linear models, multivariate adaptive regression splines, boosted regression trees, random forest, and maximum entropy models. We evaluated results using three SDM performance metrics (AUC, sensitivity, and specificity) and two data sets: one comprised of the original occurrence data, and a second data set consisting of these same records after the locations were adjusted to correct for identifiable spatial errors. The increase in precision improved the mean estimated spatial error associated with hoary bat records from 5.11 km to 1.58 km, and this reduction in error resulted in a slight increase in all three SDM performance metrics. These results provide insights into the importance of geographic referencing and the value of correcting spatial errors in modeling the distribution of a wide-ranging bat species. We conclude that the considerable time and effort invested in carefully increasing the precision of the occurrence locations in this data set was not worth the marginal gains in improved SDM performance, and it seems likely that gains would be similar for other bat species that range across large areas of the continent, migrate, and are habitat generalists.

  9. Fast fiber-optic multi-wavelength pyrometer.

    Science.gov (United States)

    Fu, Tairan; Tan, Peng; Pang, Chuanhe; Zhao, Huan; Shen, Yi

    2011-06-01

    A fast fiber-optic multi-wavelength pyrometer was developed for the ultraviolet-visible-near infrared spectra from 200 nm to 1700 nm using a CCD detector and an InGaAs detector. The pyrometer system conveniently and quickly provides the sufficient choices of multiple measurement wavelengths using optical diffraction, which avoids the use of narrow-band filters. Flexible optical fibers are used to transmit the radiation so the pyrometer can be used for temperature measurements in harsh environments. The setup and calibrations (wavelength calibration, nonlinearity calibration, and radiation response calibration) of this pyrometer system were described. Development of the multi-wavelength pyrometer involved optimization of the bandwidth and temperature discrimination of the multiple spectra data. The analysis results showed that the wavelength intervals, Δλ(CCD) = 30 nm and Δλ(InGaAs) = 50 nm, are the suitable choices as a tradeoff between the simple emissivity model assumption and the multiple signal discrimination. The temperature discrimination was also quantificationally evaluated for various wavelengths and temperatures. The measurement performance of the fiber-optic multi-wavelength pyrometer was partially verified through measurements with a high-temperature blackbody and actual hot metals. This multi-wavelength pyrometer can be used for remote high-temperature measurements. © 2011 American Institute of Physics

  10. Heterogeneous associations between smoking and a wide range of initial presentations of cardiovascular disease in 1937360 people in England: lifetime risks and implications for risk prediction.

    Science.gov (United States)

    Pujades-Rodriguez, Mar; George, Julie; Shah, Anoop Dinesh; Rapsomaniki, Eleni; Denaxas, Spiros; West, Robert; Smeeth, Liam; Timmis, Adam; Hemingway, Harry

    2015-02-01

    It is not known how smoking affects the initial presentation of a wide range of chronic and acute cardiovascular diseases (CVDs), nor the extent to which associations are heterogeneous. We estimated the lifetime cumulative incidence of 12 CVD presentations, and examined associations with smoking and smoking cessation. Cohort study of 1.93 million people aged ≥30years, with no history of CVD, in 1997-2010. Individuals were drawn from linked electronic health records in England, covering primary care, hospitalizations, myocardial infarction (MI) registry and cause-specific mortality (the CALIBER programme). During 11.6 million person-years of follow-up, 114859 people had an initial non-fatal or fatal CVD presentation. By age 90 years, current vs never smokers' lifetime risks varied from 0.4% vs 0.2% for subarachnoid haemorrhage (SAH), to 8.9% vs 2.6% for peripheral arterial disease (PAD). Current smoking showed no association with cardiac arrest or sudden cardiac death [hazard ratio (HR)=1.04, 95% confidence interval (CI) 0.91-1.19).The strength of association differed markedly according to disease type: stable angina (HR=1.08, 95% CI 1.01-1.15),transient ischaemic attack (HR=1.41, 95% CI 1.28-1.55), unstable angina (HR=1.54, 95% CI 1.38-1.72), intracerebral haemorrhage (HR=1.61, 95% CI 1.37-1.89), heart failure (HR=1.62, 95% CI 1.47-1.79), ischaemic stroke (HR=1.90, 95% CI 1.72-2.10), MI (HR=2.32, 95% CI 2.20-2.45), SAH (HR= 2.70, 95% CI 2.27-3.21), PAD (HR=5.16, 95% CI 4.80-5.54) and abdominal aortic aneurysm (AAA) (HR=5.18, 95% CI 4.61-5.82). Population-attributable fractions were lower for women than men for unheralded coronary death, ischaemic stroke, PAD and AAA. Ten years after quitting smoking, the risks of PAD, AAA (in men) and unheralded coronary death remained increased (HR=1.36, 1.47 and 2.74, respectively). The heterogeneous associations of smoking with different CVD presentations suggests different underlying mechanisms and have important

  11. Lack of parental rule-setting on eating is associated with a wide range of adolescent unhealthy eating behaviour both for boys and girls

    Directory of Open Access Journals (Sweden)

    Jana Holubcikova

    2016-04-01

    Full Text Available Abstract Background Unhealthy eating habits in adolescence lead to a wide variety of health problems and disorders. The aim of this study was to assess the prevalence of absence of parental rules on eating and unhealthy eating behaviour and to explore the relationships between parental rules on eating and a wide range of unhealthy eating habits of boys and girls. We also explored the association of sociodemographic characteristics such as gender, family affluence or parental education with eating related parental rules and eating habits of adolescents. Methods The data on 2765 adolescents aged 13–15 years (mean age: 14.4; 50.7 % boys from the Slovak part of the Health Behaviour in School-Aged Children (HBSC study 2014 were assessed. The associations between eating-related parental rules and unhealthy eating patterns using logistic regression were assessed using logistic regression. Results Unhealthy eating habits occurred frequently among adolescents (range: 18.0 % reported skipping breakfast during weekends vs. 75.8 % for low vegetables intake. Of all adolescents, 20.5 % reported a lack of any parental rules on eating (breakfast not mandatory, meal in front of TV allowed, no rules about sweets and soft drinks. These adolescents were more likely to eat unhealthily, i.e. to skip breakfast on weekdays (odds ratio/95 % confidence interval: 5.33/4.15–6.84 and on weekends (2.66/2.12–3.34, to report low consumption of fruits (1.63/1.30–2.04 and vegetables (1.32/1.04–1.68, and the frequent consumption of sweets (1.59/1.30–1.94, soft drinks (1.93/1.56–2.38 and energy drinks (2.15/1.72–2.70. Conclusions Parental rule-setting on eating is associated with eating behaviours of adolescents. Further research is needed to disentangle causality in this relationship. If causal, parents may be targeted to modify the eating habits of adolescents.

  12. Simultaneous retrieval of aerosol optical thickness and chlorophyll concentration from multiwavelength measurement over East China Sea

    Science.gov (United States)

    Shi, Chong; Nakajima, Teruyuki; Hashimoto, Makiko

    2016-12-01

    A flexible inversion algorithm is proposed for simultaneously retrieving aerosol optical thickness (AOT) and surface chlorophyll a (Chl) concentration from multiwavelength observation over the ocean. In this algorithm, forward radiation calculation is performed by an accurate coupled atmosphere-ocean model with a comprehensive bio-optical ocean module. Then, a full-physical nonlinear optimization approximation approach is used to retrieve AOT and Chl. For AOT retrieval, a global three-dimensional spectral radiation-transport aerosol model is used as the a priori constraint to increase the retrieval accuracy of aerosol. To investigate the algorithm's availability, the retrieval experiment is conducted using simulated radiance data to demonstrate that the relative errors in simultaneously determining AOT and Chl can be mostly controlled to within 10% using multiwavelength and angle covering in and out of sunglint. Furthermore, the inversion results are assessed using the actual satellite observation data obtained from Cloud and Aerosol Imager (CAI)/Greenhouse gas Observation SATellite GOSAT and MODerate resolution Imaging Spectroradiometer (MODIS)/Aqua instruments through comparison to Aerosol Robotic Network (AERONET) aerosol and ocean color (OC) products over East China Sea. Both the retrieved AOT and Chl compare favorably to the reported AERONET values, particularly when using the CASE 2 ocean module in turbid water, even when the retrieval is performed in the presence of high aerosol loading and sunglint. Finally, the CAI and MODIS images are used to jointly retrieve the spatial distribution of AOT and Chl in comparison to the MODIS AOT and OC products.

  13. Study of aerosol hygroscopic events over the Cabauw experimental site for atmospheric research (CESAR) using the multi-wavelength Raman lidar Caeli

    NARCIS (Netherlands)

    Fernández, A.J.; Apituley, A.; Veselovskii, I.; Suvorina, A.; Henzing, J.; Pujadas, M.; Artíñano, B.

    2015-01-01

    This article presents a study of aerosol optical and microphysical properties under different relative humidity (RH) but well mixed layer conditions using optical and microphysical aerosol properties from multi-wavelength (MW) Raman lidar and in-situ aerosol observations collected at the Cabauw

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

    Energy Technology Data Exchange (ETDEWEB)

    Ackermann, M.; Buehler, R. [Deutsches Elektronen Synchrotron DESY, D-15738 Zeuthen (Germany); Ajello, M. [Department of Physics and Astronomy, Clemson University, Kinard Lab of Physics, Clemson, SC 29634-0978 (United States); Albert, A.; Baldini, L.; Blandford, R. D.; Bloom, E. D.; Bottacini, E.; Caliandro, G. A. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Atwood, W. B. [Santa Cruz Institute for Particle Physics, Department of Physics and Department of Astronomy and Astrophysics, University of California at Santa Cruz, Santa Cruz, CA 95064 (United States); Ballet, J. [Laboratoire AIM, CEA-IRFU/CNRS/Université Paris Diderot, Service d’Astrophysique, CEA Saclay, F-91191 Gif sur Yvette (France); Barbiellini, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy); Bastieri, D.; Buson, S. [Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padova (Italy); Becerra Gonzalez, J. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Bellazzini, R. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Bissaldi, E. [Istituto Nazionale di Fisica Nucleare, Sezione di Bari, I-70126 Bari (Italy); Bonino, R. [Istituto Nazionale di Fisica Nucleare, Sezione di Torino, I-10125 Torino (Italy); Bregeon, J. [Laboratoire Univers et Particules de Montpellier, Université Montpellier, CNRS/IN2P3, Montpellier (France); Bruel, P., E-mail: David.J.Thompson@nasa.gov, E-mail: sara.cutini@asdc.asi.it, E-mail: stefano.ciprini@asdc.asi.it, E-mail: stefan@astro.su.se, E-mail: stamerra@oato.inaf.it [Laboratoire Leprince-Ringuet, École polytechnique, CNRS/IN2P3, Palaiseau (France); and others

    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 (E > 100 MeV) from the GeV/TeV BL Lac object PG 1553+113. The marginal significance of the 2.18 ± 0.08 year period γ-ray cycle is strengthened by correlated oscillations observed in radio and optical fluxes, through data collected in the Owens Valley Radio Observatory, Tuorla, Katzman Automatic Imaging Telescope, and Catalina Sky Survey monitoring programs and Swift-UVOT. The optical cycle appearing in ∼10 years of data has a similar period, while the 15 GHz oscillation is less regular than seen in the other bands. Further long-term multiwavelength monitoring of this blazar may discriminate among the possible explanations for this quasi-periodicity.

  15. Multiwavelength Evidence for Quasi-periodic Modulation in the Gamma-Ray Blazar PG 1553+113

    Science.gov (United States)

    Ackermann, M.; Ajello, M.; Albert, A.; Atwood, W. B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Becerra Gonzalez, J.; Bellazzini, R.; Bissaldi, E.; Blandford, R. D.; Bloom, E. D.; Bonino, R.; Bottacini, E.; Bregeon, J.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caputo, R.; Caragiulo, M.; Caraveo, P. A.; Cavazzuti, E.; Cecchi, C.; Chekhtman, A.; Chiang, J.; Chiaro, G.; Ciprini, S.; Cohen-Tanugi, J.; Conrad, J.; Cutini, S.; D'Ammando, F.; de Angelis, A.; de Palma, F.; Desiante, R.; Di Venere, L.; Domínguez, A.; Drell, P. S.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Focke, W. B.; Fuhrmann, L.; Fukazawa, Y.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Godfrey, G.; Green, D.; Grenier, I. A.; Grove, J. E.; Guiriec, S.; Harding, A. K.; Hays, E.; Hewitt, J. W.; Hill, A. B.; Horan, D.; Jogler, T.; Jóhannesson, G.; Johnson, A. S.; Kamae, T.; Kuss, M.; Larsson, S.; Latronico, L.; Li, J.; Li, L.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Magill, J.; Maldera, S.; Manfreda, A.; Max-Moerbeck, W.; Mayer, M.; Mazziotta, M. N.; McEnery, J. E.; Michelson, P. F.; Mizuno, T.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nuss, E.; Ohno, M.; Ohsugi, T.; Ojha, R.; Omodei, N.; Orlando, E.; Ormes, J. F.; Paneque, D.; Pearson, T. J.; Perkins, J. S.; Perri, M.; Pesce-Rollins, M.; Petrosian, V.; Piron, F.; Pivato, G.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Readhead, A.; Reimer, A.; Reimer, O.; Schulz, A.; Sgrò, C.; Siskind, E. J.; Spada, F.; Spandre, G.; Spinelli, P.; Suson, D. J.; Takahashi, H.; Thayer, J. B.; Thompson, D. J.; Tibaldo, L.; Torres, D. F.; Tosti, G.; Troja, E.; Uchiyama, Y.; Vianello, G.; Wood, K. S.; Wood, M.; Zimmer, S.; Berdyugin, A.; Corbet, R. H. D.; Hovatta, T.; Lindfors, E.; Nilsson, K.; Reinthal, R.; Sillanpää, A.; Stamerra, A.; Takalo, L. O.; Valtonen, M. J.

    2015-11-01

    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 (E > 100 MeV) from the GeV/TeV BL Lac object PG 1553+113. The marginal significance of the 2.18 ± 0.08 year period γ-ray cycle is strengthened by correlated oscillations observed in radio and optical fluxes, through data collected in the Owens Valley Radio Observatory, Tuorla, Katzman Automatic Imaging Telescope, and Catalina Sky Survey monitoring programs and Swift-UVOT. The optical cycle appearing in ˜10 years of data has a similar period, while the 15 GHz oscillation is less regular than seen in the other bands. Further long-term multiwavelength monitoring of this blazar may discriminate among the possible explanations for this quasi-periodicity.

  16. Cosmogenic exposure dating of boulders and bedrock in Denmark: wide range in ages reflect strong dependence of post-depositional stability related to specific glacial landforms

    Science.gov (United States)

    Houmark-Nielsen, Michael; Linge, Henriette; Fabel, Derek; Xu, Sheng

    2010-05-01

    The timing of ice-sheet fluctuations, as indicated by glacier advances and retreats, is detected from a wide range of geochronological techniques, including varve counting, and radiocarbon and luminescence dating of proglacial and inter till sediments. A robust Late Weichselian chronology of deglacial ice sheet fluctuations in southwestern Scandinavia indicates that the decline of the Scandinavian Ice Sheet from the Last Glacial Maximum position at c. 23-21 kyr (thousands of years) ago in central Denmark occurred through recessional stages and readvances. Active glaciers withdrew from eastern Denmark 17-16 kyr ago and left the southwestern Baltic basin ice free at the beginning of the Bølling interstade c. 14.5 kyr ago. The withdrawal left behind belts of elongate end moraines and streamlined ground moraine as large ice masses were successively isolated causing massive down wasting until c. 12 - 11 kyr ago. In Eastern Denmark and southernmost Sweden this lead to formation of complex superimposed glacial landscapes originally covered with a wealth of erratic boulders. Hitherto untried cosmogenic nuclide surface exposure dating was applied to sites in Eastern Denmark to test the method against independent chronologies. Samples collected from erratics, moraines and ice-sculpted bedrock were prepared at the Cosmogenic Nuclide Laboratory at the University of Glasgow and AMS measurements were carried out at the Scottish Universities Environmental Research Centre (SUERC) AMS facility. Procedural blank corrected 10Be concentrations were converted to in situ 10Be surface exposure ages using the online CRONUS-Earth 10Be-26Al exposure age calculator Version 2.2. Exposure ages from 35 samples range between 11.5 and 20 kyr, 18 of which lie within the expected age envelope. Two samples show overestimated ages apparently due to cosmogenic nuclide inheritance from previous exposure episodes. The remaining 17, two of which have suffered from exhumation, are younger than predicted

  17. A Multiwavelength Study of the Intracluster Medium and the Characterization of the Multiwavelength Sub/millimeter Inductance Camera

    Science.gov (United States)

    Siegel, Seth Robert

    The first part of this thesis combines Bolocam observations of the thermal Sunyaev-Zel'dovich (SZ) effect at 140 GHz with X-ray observations from Chandra, strong lensing data from the Hubble Space Telescope (HST), and weak lensing data from HST and Subaru to constrain parametric models for the distribution of dark and baryonic matter in a sample of six massive, dynamically relaxed galaxy clusters. For five of the six clusters, the full multiwavelength dataset is well described by a relatively simple model that assumes spherical symmetry, hydrostatic equilibrium, and entirely thermal pressure support. The multiwavelength analysis yields considerably better constraints on the total mass and concentration compared to analysis of any one dataset individually. The subsample of five galaxy clusters is used to place an upper limit on the fraction of pressure support in the intracluster medium (ICM) due to nonthermal processes, such as turbulent and bulk flow of the gas. We constrain the nonthermal pressure fraction at r500c to be less than 0.11 at 95% confidence, where r500c refers to radius at which the average enclosed density is 500 times the critical density of the Universe. This is in tension with state-of-the-art hydrodynamical simulations, which predict a nonthermal pressure fraction of approximately 0.25 at r500c for the clusters in this sample. The second part of this thesis focuses on the characterization of the Multiwavelength Sub/millimeter Inductance Camera (MUSIC), a photometric imaging camera that was commissioned at the Caltech Submillimeter Observatory (CSO) in 2012. MUSIC is designed to have a 14 arcminute, diffraction-limited field of view populated with 576 spatial pixels that are simultaneously sensitive to four bands at 150, 220, 290, and 350 GHz. It is well-suited for studies of dusty star forming galaxies, galaxy clusters via the SZ Effect, and galactic star formation. MUSIC employs a number of novel detector technologies: broadband phased

  18. Wide-range high-resolution transmission electron microscopy reveals morphological and distributional changes of endomembrane compartments during log to stationary transition of growth phase in tobacco BY-2 cells.

    Science.gov (United States)

    Toyooka, Kiminori; Sato, Mayuko; Kutsuna, Natsumaro; Higaki, Takumi; Sawaki, Fumie; Wakazaki, Mayumi; Goto, Yumi; Hasezawa, Seiichiro; Nagata, Noriko; Matsuoka, Ken

    2014-09-01

    Rapid growth of plant cells by cell division and expansion requires an endomembrane trafficking system. The endomembrane compartments, such as the Golgi stacks, endosome and vesicles, are important in the synthesis and trafficking of cell wall materials during cell elongation. However, changes in the morphology, distribution and number of these compartments during the different stages of cell proliferation and differentiation have not yet been clarified. In this study, we examined these changes at the ultrastructural level in tobacco Bright yellow 2 (BY-2) cells during the log and stationary phases of growth. We analyzed images of the BY-2 cells prepared by the high-pressure freezing/freeze substitution technique with the aid of an auto-acquisition transmission electron microscope system. We quantified the distribution of secretory and endosomal compartments in longitudinal sections of whole cells by using wide-range gigapixel-class images obtained by merging thousands of transmission electron micrographs. During the log phase, all Golgi stacks were composed of several thick cisternae. Approximately 20 vesicle clusters (VCs), including the trans-Golgi network and secretory vesicle cluster, were observed throughout the cell. In the stationary-phase cells, Golgi stacks were thin with small cisternae, and only a few VCs were observed. Nearly the same number of multivesicular body and small high-density vesicles were observed in both the stationary and log phases. Results from electron microscopy and live fluorescence imaging indicate that the morphology and distribution of secretory-related compartments dramatically change when cells transition from log to stationary phases of growth. © The Author 2014. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  19. Results from HOPS: A multiwavelength census of Orion protostars

    Science.gov (United States)

    Fischer, W. J.; Megeath, S. T.; Stutz, A. M.; Tobin, J. J.; Ali, B.; Stanke, T.; Osorio, M.; Furlan, E.; HOPS Team; Orion Protostar Survey

    2013-02-01

    Surveys with the Spitzer and Herschel space observatories are now enabling the discovery and characterization of large samples of protostars in nearby molecular clouds, providing the observational basis for a detailed understanding of star formation in diverse environments. We are pursuing this goal with the Herschel Orion Protostar Survey (HOPS), which targets 328 Spitzer-identified protostars in the Orion molecular clouds, the largest star-forming region in the nearest 500 pc. The sample encompasses all phases of protostellar evolution and a wide range of formation environments, from dense clusters to relative isolation. With a grid of radiative transfer models, we fit the 1-870 μm spectral energy distributions (SEDs) of the protostars to estimate their envelope densities, cavity opening angles, inclinations, and total luminosities. After correcting the bolometric luminosities and temperatures of the sources for foreground extinction and inclination, we find a spread of several orders of magnitude in luminosity at all evolutionary states, a constant median luminosity over the more evolved stages, and a possible deficit of high-inclination, rapidly infalling envelopes among the Spitzer-identified sample. We have detected over 100 new sources in the Herschel images; some of them may fill this deficit. We also report results from modeling the pre- and post-outburst 1-870 μm SEDs of V2775 Ori (HOPS 223), a known FU Orionis outburster in the sample. It is the least luminous FU Ori star with a protostellar envelope.

  20. Multiwavelength Picture of the Blazar S5 0716+714 during Its Brightest Outburst

    Directory of Open Access Journals (Sweden)

    Marina Manganaro

    2016-11-01

    Full Text Available S5 0716+714 is a well known BL Lac object, and one of the brightest and most active blazars. The discovery in the Very High Energy band (VHE, E > 100 GeV by MAGIC happened in 2008. In January 2015, the source went through the brightest optical state ever observed, triggering MAGIC follow-up and a VHE detection with ∼ 13 σ significance (ATel ♯ 6999 . Rich multiwavelength coverage of the flare allowed us to construct the broad-band spectral energy distribution of S5 0716+714 during its brightest outburst. In this work, we will present the preliminary analysis of MAGIC and Fermi-LAT data of the flaring activity in January and February 2015 for the HE (0.1 < HE < 300 GeV and VHE band, together with radio (Metsähovi, OVRO, VLBA, Effelsberg, sub-millimeter (SMA, optical (Tuorla, Perkins, Steward, AZT-8+ST7, LX-200, Kanata, X-ray and UV (Swift-XRT and UVOT, in the same time-window and discuss the time variability of the multiwavelength light curves during this impressive outburst.

  1. Multiwavelength classification of Galactic X-ray sources using machine-learning

    Science.gov (United States)

    Hare, Jeremy; Kargaltsev, Oleg; Rangelov, Blagoy; Pavlov, George G.; Posselt, Bettina; Volkov, Igor

    2018-01-01

    Observations with Chandra and XMM-Newton X-ray observatories have detected a large number of Galactic sources serendipitously. The X-ray properties of these sources are extracted and placed into catalogs where they remain largely unexplored. These rich datasets hold excellent potential for population studies of various types of astrophysical sources and may also hide rare source types, which we are yet to discover. However, X-ray data alone is often not enough to classify these sources and multiwavelength data must be used. We have developed a multiwavelength machine-learning pipeline (MUWCLASS), which uses a rich training dataset (of about 10,000 sources of known types) to classify X-ray sources. We describe the pipeline, training dataset, and verification and validation procedures used to build the pipeline. We then present and discuss the results of the classifications of X-ray sources, as well as the code's performance in multiple example environments, including dwarf galaxies, stellar clusters, SNRs, unidentified TeV sources, and a wide Galactic disk field.

  2. A Multi-Wavelength View of Planet Forming Regions: Unleashing the Full Power of ALMA

    Science.gov (United States)

    Tazzari, Marco

    2017-11-01

    Observations at sub-mm/mm wavelengths allow us to probe the solids in the interior of protoplanetary disks, where the bulk of the dust is located and planet formation is expected to occur. However, the actual size of dust grains is still largely unknown due to the limited angular resolution and sensitivity of past observations. The upgraded VLA and, especially, the ALMA observatories provide now powerful tools to resolve grain growth in disks, making the time ripe for developing a multi-wavelength analysis of sub-mm/mm observations of disks. In my contribution I will present a novel analysis method for multi-wavelength ALMA/VLA observations which, based on the self-consistent modelling of the sub-mm/mm disk continuum emission, allows us to constrain simultaneously the size distribution of dust grains and the disk's physical structure (Tazzari et al. 2016, A&A 588 A53). I will also present the recent analysis of spatially resolved ALMA Band 7 observations of a large sample of disks in the Lupus star forming region, from which we obtained a tentative evidence of a disk size-disk mass correlation (Tazzari et al. 2017, arXiv:1707.01499). Finally, I will introduce galario, a GPU Accelerated Library for the Analysis of Radio Interferometry Observations. Fitting the observed visibilities in the uv-plane is computationally demanding: with galario we solve this problem for the current as well as for the full-science ALMA capabilities by leveraging on the computing power of GPUs, providing the computational breakthrough needed to fully exploit the new wealth of information delivered by ALMA.

  3. Tunable multiwavelength mode-locked Tm/Ho-doped fiber laser based on a nonlinear amplified loop mirror.

    Science.gov (United States)

    Jin, Xiaoxi; Wang, Xiong; Wang, Xiaolin; Zhou, Pu

    2015-10-01

    We propose and demonstrate a tunable multiwavelength mode-locked Tm/Ho-doped fiber laser based on a nonlinear amplified loop mirror (NALM). Without using polarization-maintaining fiber, only passive fibers with low birefringence were inserted into the NALM to help overcome mode competition and realize mode-locking. The spacing between adjacent channels was measured to be ∼6  nm. By adjusting the polarization controllers (PCs) to an appropriate position, self-started mode-locking was achieved, which further overcame the mode competition in the fiber laser. A multiwavelength mode-locked fiber laser with at least three available channels were tunable in the widest range of 30 nm (from 1935 to 1965 nm) with a 3 dB channel bandwidth of ∼1.6  nm. This multiwavelength mode-locked fiber laser is quite stable with the maximum peak fluctuation within 0.47 dB in long-term observations.

  4. Temperature Measurement of Ceramic Materials Using a Multiwavelength Pyrometer

    Science.gov (United States)

    Ng, Daniel; Fralick, Gustave

    1999-01-01

    The surface temperatures of several pure ceramic materials (alumina, beryllia, magnesia, yittria and spinel) in the shape of pellets were measured using a multiwavelength pyrometer. In one of the measurements, radiation signal collection is provided simply by an optical fiber. In the other experiments, a 4.75 inch (12 cm) parabolic mirror collects the signal for the spectrometer. Temperature measurement using the traditional one- and two-color pyrometer for these ceramic materials is difficult because of their complex optical properties, such as low emissivity which varies with both temperature and wavelength. In at least one of the materials, yittria, the detected optical emission increased as the temperature was decreased due to such emissivity variation. The reasons for such changes are not known. The multiwavelength pyrometer has demonstrated its ability to measure surface temperatures under such conditions. Platinum electrodes were embedded in the ceramic pellets for resistance measurements as the temperature changed.

  5. Multi-wavelength lasers with suppressed spectral linewidth of 10 kHz.

    Science.gov (United States)

    Wang, Tianhe; Yang, Tianxin; Jia, Dongfang; Wang, Zhaoying; Ge, Chunfeng

    2014-11-03

    High coherent multi-wavelength or multi-tone light source are in high demand for optical density wavelength division multiplexed (DWDM) networks as the telecommunication capacity expands exponentially. However the linewidths of commercial multi-wavelength semiconductor lasers are typically a few MHz which is not acceptable when the frequency spacing of the multi-tones is 10 GHz. In this paper, a novel and simple method to suppress the linewidths of the multi-wavelength from ~6 MHz to ~10 kHz using an all-optical approach is proposed and demonstrated. The linewidths of the multi-wavelength are suppressed by a factor of 600 and the noise level of the multi-wavelength is decreased by nearly 20 dB. Each wavelength of the multi-wavelength operates in single longitudinal mode. Finally, more than 8 wavelengths over 10 nm are suppressed simultaneously through the approach and scheme presented in this work.

  6. Multiwavelength studies of X-ray selected extragalactic sample

    OpenAIRE

    Mickaelian, A. M.; Paronyan, G. M.; Harutyunyan, G. S.; Abrahamyan, H. V.; Gyulzadyan, M. V.

    2015-01-01

    The joint catalogue of Active Galactic Nuclei selected from optical identifications of X-ray sources was created as a combination of two samples: Hamburg-ROSAT Catalogue (HRC) and Byurakan-Hamburg-ROSAT Catalogue (BHRC). Both are based on optical identifications of X-ray sources from ROSAT catalogues using low-dispersion spectra of Hamburg Quasar Survey (HQS). However, HRC and BHRC contain a number of misidentifications and using the recent optical and multiwavelength (MW) catalogues we have ...

  7. Temperature Measurement of a Glass Material Using a Multiwavelength Pyrometer

    Science.gov (United States)

    Ng, Daniel

    1997-01-01

    Temperature measurement of a substance that is transparent using the traditional 1-color, 2-color and other pyrometers has been difficult. The radiation detected by pyrometers do not come from a well defined location in the transparent body. The multiwavelength pyrometer developed at the NASA Lewis Research Center can measure the surface temperature of many materials. We show in this paper that it also measures the surface and a bulk subsurface temperature of transparent materials like glass.

  8. Resolving model parameter values from carbon and nitrogen stock measurements in a wide range of tropical mature forests using nonlinear inversion and regression trees

    Science.gov (United States)

    Shuguang Liua; Pamela Anderson; Guoyi Zhoud; Boone Kauffman; Flint Hughes; David Schimel; Vicente Watson; Joseph. Tosi

    2008-01-01

    Objectively assessing the performance of a model and deriving model parameter values from observations are critical and challenging in landscape to regional modeling. In this paper, we applied a nonlinear inversion technique to calibrate the ecosystem model CENTURY against carbon (C) and nitrogen (N) stock measurements collected from 39 mature tropical forest sites in...

  9. Linear estimation of particle bulk parameters from multi-wavelength lidar measurements

    Directory of Open Access Journals (Sweden)

    I. Veselovskii

    2012-05-01

    Full Text Available An algorithm for linear estimation of aerosol bulk properties such as particle volume, effective radius and complex refractive index from multiwavelength lidar measurements is presented. The approach uses the fact that the total aerosol concentration can well be approximated as a linear combination of aerosol characteristics measured by multi-wavelength lidar. Therefore, the aerosol concentration can be estimated from lidar measurements without the need to derive the size distribution, which entails more sophisticated procedures. The definition of the coefficients required for the linear estimates is based on an expansion of the particle size distribution in terms of the measurement kernels. Once the coefficients are established, the approach permits fast retrieval of aerosol bulk properties when compared with the full regularization technique. In addition, the straightforward estimation of bulk properties stabilizes the inversion making it more resistant to noise in the optical data.

    Numerical tests demonstrate that for data sets containing three aerosol backscattering and two extinction coefficients (so called 3β + 2α the uncertainties in the retrieval of particle volume and surface area are below 45% when input data random uncertainties are below 20%. Moreover, using linear estimates allows reliable retrievals even when the number of input data is reduced. To evaluate the approach, the results obtained using this technique are compared with those based on the previously developed full inversion scheme that relies on the regularization procedure. Both techniques were applied to the data measured by multiwavelength lidar at NASA/GSFC. The results obtained with both methods using the same observations are in good agreement. At the same time, the high speed of the retrieval using linear estimates makes the method preferable for generating aerosol information from extended lidar observations. To demonstrate the efficiency

  10. Multiwavelength Mapping of Galaxy Formation and Evolution

    CERN Document Server

    Renzini, Alvio; ESO Workshop

    2005-01-01

    The possibilities of astronomical observation have dramatically increased over the last decade. Major satellites, like the Hubble Space Telescope, Chandra and XMM Newton, are complemented by numerous large ground-based observatories, from 8m-10m optical telescopes to sub-mm and radio facilities. As a result, observational astronomy has access to virtually the whole electromagnetic spectrum of galaxies, even at high redshifts. Theoretical models of galaxy formation and cosmological evolution now face a serious challenge to match the plethora of observational data. In October 2003, over 170 astronomers from 15 countries met for a 4-day workshop to extensively illustrate and discuss all major observational projects and ongoing theoretical efforts to model galaxy formation and evolution. This volume contains the complete proceedings of this meeting and is therefore a unique and timely overview of the current state of research in this rapidly evolving field.

  11. Multiwavelength light curve parameters of Cepheid variables

    Directory of Open Access Journals (Sweden)

    Bhardwaj Anupam

    2017-01-01

    Full Text Available We present a comparative analysis of theoretical and observed light curves of Cepheid variables using Fourier decomposition. The theoretical light curves at multiple wavelengths are generated using stellar pulsation models for chemical compositions representative of Cepheids in the Galaxy and Magellanic Clouds. The observed light curves at optical (VI, near-infrared (JHKs and mid-infrared (3.6 & 4.5-μm bands are compiled from the literature. We discuss the variation of light curve parameters as a function of period, wavelength and metallicity. Theoretical and observed Fourier amplitude parameters decrease with increase in wavelength while the phase parameters increase with wavelength. We find that theoretical amplitude parameters obtained using canonical mass-luminosity levels exhibit a greater offset with respect to observations when compared to non-canonical relations. We also discuss the impact of variation in convective efficiency on the light curve structure of Cepheid variables. The increase in mixing length parameter results in a zero-point offset in bolometric mean magnitudes and reduces the systematic large difference in theoretical amplitudes with respect to observations.

  12. Target categorization of aerosol and clouds by continuous multiwavelength-polarization lidar measurements

    Science.gov (United States)

    Baars, Holger; Seifert, Patric; Engelmann, Ronny; Wandinger, Ulla

    2017-09-01

    Absolute calibrated signals at 532 and 1064 nm and the depolarization ratio from a multiwavelength lidar are used to categorize primary aerosol but also clouds in high temporal and spatial resolution. Automatically derived particle backscatter coefficient profiles in low temporal resolution (30 min) are applied to calibrate the lidar signals. From these calibrated lidar signals, new atmospheric parameters in temporally high resolution (quasi-particle-backscatter coefficients) are derived. By using thresholds obtained from multiyear, multisite EARLINET (European Aerosol Research Lidar Network) measurements, four aerosol classes (small; large, spherical; large, non-spherical; mixed, partly non-spherical) and several cloud classes (liquid, ice) are defined. Thus, particles are classified by their physical features (shape and size) instead of by source. The methodology is applied to 2 months of continuous observations (24 h a day, 7 days a week) with the multiwavelength-Raman-polarization lidar PollyXT during the High-Definition Clouds and Precipitation for advancing Climate Prediction (HD(CP)2) Observational Prototype Experiment (HOPE) in spring 2013. Cloudnet equipment was operated continuously directly next to the lidar and is used for comparison. By discussing three 24 h case studies, it is shown that the aerosol discrimination is very feasible and informative and gives a good complement to the Cloudnet target categorization. Performing the categorization for the 2-month data set of the entire HOPE campaign, almost 1 million pixel (5 min × 30 m) could be analysed with the newly developed tool. We find that the majority of the aerosol trapped in the planetary boundary layer (PBL) was composed of small particles as expected for a heavily populated and industrialized area. Large, spherical aerosol was observed mostly at the top of the PBL and close to the identified cloud bases, indicating the importance of hygroscopic growth of the particles at high relative

  13. E-cadherin acts as a regulator of transcripts associated with a wide range of cellular processes in mouse embryonic stem cells.

    Directory of Open Access Journals (Sweden)

    Francesca Soncin

    Full Text Available We have recently shown that expression of the cell adhesion molecule E-cadherin is required for LIF-dependent pluripotency of mouse embryonic stem (ES cells.In this study, we have assessed global transcript expression in E-cadherin null (Ecad-/- ES cells cultured in either the presence or absence of LIF and compared these to the parental cell line wtD3.We show that LIF has little effect on the transcript profile of Ecad-/- ES cells, with statistically significant transcript alterations observed only for Sp8 and Stat3. Comparison of Ecad-/- and wtD3 ES cells cultured in LIF demonstrated significant alterations in the transcript profile, with effects not only confined to cell adhesion and motility but also affecting, for example, primary metabolic processes, catabolism and genes associated with apoptosis. Ecad-/- ES cells share similar, although not identical, gene expression profiles to epiblast-derived pluripotent stem cells, suggesting that E-cadherin expression may inhibit inner cell mass to epiblast transition. We further show that Ecad-/- ES cells maintain a functional β-catenin pool that is able to induce β-catenin/TCF-mediated transactivation but, contrary to previous findings, do not display endogenous β-catenin/TCF-mediated transactivation. We conclude that loss of E-cadherin in mouse ES cells leads to significant transcript alterations independently of β-catenin/TCF transactivation.

  14. DustPedia: Multiwavelength photometry and imagery of 875 nearby galaxies in 42 ultraviolet-microwave bands

    Science.gov (United States)

    Clark, C. J. R.; Verstocken, S.; Bianchi, S.; Fritz, J.; Viaene, S.; Smith, M. W. L.; Baes, M.; Casasola, V.; Cassara, L. P.; Davies, J. I.; De Looze, I.; De Vis, P.; Evans, R.; Galametz, M.; Jones, A. P.; Lianou, S.; Madden, S.; Mosenkov, A. V.; Xilouris, M.

    2018-01-01

    Aims: The DustPedia project is capitalising on the legacy of the Herschel Space Observatory, using cutting-edge modelling techniques to study dust in the 875 DustPedia galaxies - representing the vast majority of extended galaxies within 3000 km s-1 that were observed by Herschel. This work requires a database of multiwavelength imagery and photometry that greatly exceeds the scope (in terms of wavelength coverage and number of galaxies) of any previous local-Universe survey. Methods: We constructed a database containing our own custom Herschel reductions, along with standardised archival observations from GALEX, SDSS, DSS, 2MASS, WISE, Spitzer, and Planck. Using these data, we performed consistent aperture-matched photometry, which we combined with external supplementary photometry from IRAS and Planck. Results: We present our multiwavelength imagery and photometry across 42 UV-microwave bands for the 875 DustPedia galaxies. Our aperture-matched photometry, combined with the external supplementary photometry, represents a total of 21 857 photometric measurements. A typical DustPedia galaxy has multiwavelength photometry spanning 25 bands. We also present the Comprehensive & Adaptable Aperture Photometry Routine (CAAPR), the pipeline we developed to carry out our aperture-matched photometry. CAAPR is designed to produce consistent photometry for the enormous range of galaxy and observation types in our data. In particular, CAAPR is able to determine robust cross-compatible uncertainties, thanks to a novel method for reliably extrapolating the aperture noise for observations that cover a very limited amount of background. Our rich database of imagery and photometry is being made available to the community. Photometry data tables are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/609/A37

  15. Long-Term Outcomes Associated with Traumatic Brain Injury in Childhood and Adolescence: A Nationwide Swedish Cohort Study of a Wide Range of Medical and Social Outcomes.

    Directory of Open Access Journals (Sweden)

    Amir Sariaslan

    2016-08-01

    psychiatric inpatient hospitalisation (adjusted relative risk [aRR] = 2.0; 95% CI: 1.9-2.0; 6,632 versus 37,095 events, disability pension (aRR = 1.8; 95% CI: 1.7-1.8; 4,691 versus 29,778 events, and premature mortality (aRR = 1.7; 95% CI: 1.6-1.9; 799 versus 4,695 events. These risks were only marginally attenuated when the comparisons were made with their unaffected siblings, which implies that the effects of TBI were consistent with a causal inference. A dose-response relationship was observed with injury severity. Injury recurrence was also associated with higher risks-in particular, for disability pension we found that recurrent TBI was associated with a 3-fold risk increase (aRR = 2.6; 95% CI: 2.4-2.8 compared to a single-episode TBI. Higher risks for all outcomes were observed for those who had sustained their first injury at an older age (ages 20-24 y with more than 25% increase in relative risk across all outcomes compared to the youngest age group (ages 0-4 y. On the population level, TBI explained between 2%-6% of the variance in the examined outcomes. Using hospital data underestimates milder forms of TBI, but such misclassification bias suggests that the reported estimates are likely conservative. The sibling-comparison design accounts for unmeasured familial confounders shared by siblings, including half of their genes. Thus, residual genetic confounding remains a possibility but will unlikely alter our main findings, as associations were only marginally attenuated within families.Given our findings, which indicate potentially causal effects between TBI exposure in childhood and later impairments across a range of health and social outcomes, age-sensitive clinical guidelines should be considered and preventive strategies should be targeted at children and adolescents.

  16. Solvation molar enthalpies and heat capacities of n-alkanes and n-alkylbenzenes on stationary phases of wide-ranging polarity.

    Science.gov (United States)

    Lebrón-Aguilar, Rosa; Quintanilla-López, Jesús Eduardo; Santiuste, José María

    2010-12-03

    A comparison of the most usual gas chromatographic methods for the calculation of partial molar enthalpies of solvation (Δ(sol)H(o)) has been carried out. Those methods based on the fitting of lnV(g) or ln(k/T) vs. 1/T and ln(k/T) vs. (1/T and the temperature arrangement, T(a)) are the most adequate ones for obtaining Δ(sol)H(o) values. However, the latter is the only reliable option for Δ(sol)H(o) estimation when commercial WCOT capillary columns are used, since in this case the estimation of some variables involved in the V(g) determination is less accurate or even impossible. Consequently, in this paper, Δ(sol)H(o) obtained from ln(k/T) vs. (1/T+T(a)) fitting at 373.15 and 298.15K for n-alkanes and n-alkylbenzenes on 12 commercial capillary columns coated with stationary phases covering the 203-3608 McReynolds polarity range are reported. Moreover, molar heat capacities of solvation at constant pressure (Δ(sol)C(p)(o)) have also been calculated using this method. A clear influence on Δ(sol)H(o) of the type and content of the substitution group in the stationary phase was observed. In addition, a linear relationship of Δ(sol)C(p)(o) with the van der Waals volume of the n-alkanes and the temperature gradient of density of the stationary phase was found. The effect of the size of the hydrocarbon on both thermodynamic variables was also investigated. Copyright © 2010 Elsevier B.V. All rights reserved.

  17. Dye@bio-MOF-1 Composite as a Dual-Emitting Platform for Enhanced Detection of a Wide Range of Explosive Molecules.

    Science.gov (United States)

    Wang, Chen; Tian, Li; Zhu, Wei; Wang, Shiqiang; Wang, Peng; Liang, Yun; Zhang, Wanlin; Zhao, Hongwei; Li, Guangtao

    2017-06-14

    By incorporating a cationic dye within a metal-organic framework (MOF) through an ion-exchange process, a responsive dye@bio-MOF-1 composite has been synthesized, serving as a dual-emitting platform for enhanced detection of different kinds of nitro-explosives, especially nitroalkanes, nitramines, and nitrate esters. The dye@bio-MOF-1 composite was constructed with free amines on their well-defined cavities, which is essential for the capture of explosives into their confined nanospace. It was observed that the encapsulation of explosives into the constructed dye@bio-MOF-1 composite could dramatically alter the luminescent properties of the dyes as well as the MOF skeletons owing to the size exclusivity and confinement-induced effect. For nitroaromatics, the dye@bio-MOF-1 composite exhibits turn-off responses via fluorescence quenching. Unexpectedly, the composite shows unique turn-on responses for aliphatic nitro-organics via confinement-induced enhancement, demonstrating enhanced ability to detecting different kinds of explosives selectively in aqueous solution. Furthermore, the dye@bio-MOF-1 film was facilely fabricated, making the chemical sensing more convenient and easier to realize the discrimination of the targeted explosives. The dual tunable responses indicate that dye@bio-MOF-1 composites are favorable materials for molecular sensing. On the basis of the host-guest properties of the constructed dye@bio-MOF-1 composite, our work can be further extended to sensing specific analytes with remarkable turn-on sensing properties, in particular those difficult to recognize with conventional methods.

  18. Reversible amorphous-crystalline phase changes in a wide range of Se(1-x)Te(x) alloys studied using ultrafast differential scanning calorimetry.

    Science.gov (United States)

    Vermeulen, Paul A; Momand, Jamo; Kooi, Bart J

    2014-07-14

    The reversible amorphous-crystalline phase change in a chalcogenide material, specifically the Se1-xTex alloy, has been investigated for the first time using ultrafast differential scanning calorimetry. Heating rates and cooling rates up to 5000 K/s were used. Repeated reversible amorphous-crystalline phase switching was achieved by consecutively melting, melt-quenching, and recrystallizing upon heating. Using a well-conditioned method, the composition of a single sample was allowed to shift slowly from 15 at. %Te to 60 at. %Te, eliminating sample-to-sample variability from the measurements. Using Energy Dispersive X-ray Spectroscopy composition analysis, the onset of melting for different Te-concentrations was confirmed to coincide with the literature solidus line, validating the use of the onset of melting Tm as a composition indicator. The glass transition Tg and crystallization temperature Tc could be determined accurately, allowing the construction of extended phase diagrams. It was found that Tm and Tg increase (but Tg/Tm decrease slightly) with increasing Te-concentration. Contrarily, the Tc decreases substantially, indicating that the amorphous phase becomes progressively unfavorable. This coincides well with the observation that the critical quench rate to prevent crystallization increases about three orders of magnitude with increasing Te concentration. Due to the employment of a large range of heating rates, non-Arrhenius behavior was detected, indicating that the undercooled liquid SeTe is a fragile liquid. The activation energy of crystallization was found to increase 0.5-0.6 eV when the Te concentration increases from 15 to 30 at. % Te, but it ceases to increase when approaching 50 at. % Te.

  19. The Kepler Mission: A Mission to Determine the Frequency of Inner Planets Neat the Habitable Zone of a Wide Range of Stars

    Science.gov (United States)

    Borucki, W. J.; Koch, D. G.; Dunham, E. W.; Jenkins, J. M.; Young, Richard E. (Technical Monitor)

    1997-01-01

    The surprising discovery of giant planets in inner orbits around solar-like stars has brought into question our understanding of the development and evolution of planetary systems, including our solar system. To make further progress, it is critical to detect and obtain data on the frequency and characteristics of Earth-class planets. The Kepler Mission is designed to be a quick, low-cost approach to accomplish that objective. Transits by Earth-class planets produce a fractional change in stellar brightness of 5 x 10(exp -5) to 40 x 10(exp -5) lasting for 4 to 16 hours, From the period and depth of the transits, the orbit and size of the planets can be calculated. The proposed instrument is a one-meter aperture photometer with a 12 deg field-of-view (FOV). To obtain the required precision and to avoid interruptions caused by day-night and seasonal cycles, the photometer will be launched into a heliocentric orbit. It will continuously and simultaneously monitor the flux from 80,000 dwarf stars brighter than 14th magnitude in the Cygnus constellation. The mission tests the hypothesis that the formation of most stars produces Earth-class planets in inner orbits. Based on this assumption and the recent observations that 2% of the stars have giant planets in inner orbits, several types of results are expected from the mission: 1. From transits of Earth-class planets, about 480 planet detections and 60 cases where two or more planets are found in the same system. 2. From transits of giant planets, about 160 detections of inner-orbit planets and 24 detections of outer-orbit planets. 3. From the phase modulation of the reflected light from giant planets, about 1400 planet detections with periods less than a week, albedos for 160 of these giant planets, and densities for seven planets.

  20. The Kepler Mission: A Mission to Determine the Frequency of Inner Planets Near the Habitable Zone of a Wide Range of Stars

    Science.gov (United States)

    Borucki, W. J.; Koch, D. G.; Dunham, E. W.; Jenkins, J. M.

    1997-01-01

    The surprising discovery of giant planets in inner orbits around solar-like stars has brought into question our understanding of the development and evolution of planetary systems, including our solar system. To make further progress, it is critical to detect and obtain data on the frequency and characteristics of Earth-class planets. The Kepler Mission is designed to be a quick, low-cost approach to accomplish that objective. Transits by Earth-class planets produce a fractional change. in stellar brightness of 5 x 10(exp -5) to 40 x 10(exp -5) lasting for 4 to 16 hours. From the period and depth of the transits, the orbit and size of the planets can be calculated. The proposed instrument is a one-meter aperture photometer with a 12 deg. field-of-view (FOV). To obtain the required precision and to avoid interruptions caused by day-night and seasonal cycles, the photometer will be launched into a heliocentric orbit. It will continuously and simultaneously monitor the flux from 80,000 dwarf stars brighter than 14th magnitude in the Cygnus constellation. The mission tests the hypothesis that the formation of most stars produces Earth-class planets in inner orbits. Based on this assumption and the recent observations that 2% of the stars have giant planets in inner orbits, several types of results are expected from the mission: 1. From transits of Earth-class planets, about 480 planet detections and 60 cases where two or more planets are found in the same system. 2. From transits of giant planets, about 160 detections of inner-orbit planets and 24 detections of outer-orbit planets. 3. From the phase modulation of the reflected light from giant planets, about 1400 planet detections with periods less than a week, albedos for 160 of these giant planets, and densities for seven planets.

  1. Monitoring metal contamination of silicon by multiwavelength room temperature photoluminescence spectroscopy

    Directory of Open Access Journals (Sweden)

    Shiu-Ko Jang Jian

    2012-12-01

    Full Text Available Thin thermal oxide film (∼36 nm was grown on p--Si (100 wafers in a vertical furnace at 950 °C for 90 min in 1 atm dry O2 as a vehicle for monitoring metal contamination. They are annealed in separate vertical furnaces at 1100°C for 120 min in N2 and tested for metal contamination using multiwavelength room temperature photoluminescence (RTPL, inductively coupled plasma mass spectroscopy (ICP-MS and secondary ion mass spectroscopy (SIMS. Significant RTPL intensity and spectral variations, corresponding to the degree of metal contamination, were observed. Nondestructive wafer mapping and virtual depth profiling capabilities of RTPL is a very attractive metal contamination monitoring technique.

  2. A novel C-type lectin, Nattectin-like protein, with a wide range of bacterial agglutination activity in large yellow croaker Larimichthys crocea.

    Science.gov (United States)

    Lv, Changhuan; Zhang, Dongling; Wang, Zhiyong

    2016-03-01

    C-type lectins (CTLs) are generally recognized as a superfamily of Ca(2+)-dependent carbohydrate-binding proteins, which serve as pattern recognition receptors (PRRs) in innate immunity of vertebrates. In this study, the molecular characterization and immune roles of a novel CTL from Larimichthys crocea (designated as LcNTC) were investigated. LcNTC is a novel protein that shared 33%-49% homology with other teleosts CTLs. The full-length cDNA of LcNTC was composed of 859 bp with a 465 bp open reading frame encoding a putative protein of 154 residues. LcNTC contained a single CRD with four conserved disulfide-bonded cysteine residues (Cys(57)-Cys(148), Cys(126)-Cys(140)) and EPN/AND motifs instead of invariant EPN/WND motifs required for carbohydrate-binding specificity and constructing Ca(2+)-binding sites. LcNTC mRNA was detected in all examined tissues with the most abundant in the gill. After challenged with poly I:C and Vibrio parahaemolyticus, the temporal expression of LcNTC was significantly up-regulated in the liver, spleen and head-kidney. LcNTC transcripts were also induced in the gill, skin, spleen and head-kidney post-infection with Cryptocaryon irritans. The recombinant LcNTC (rLcNTC) purified from Escherichia coli BL21 (DE3) exhibited strong agglutination activity against erythrocytes from human, rabbit and large yellow croaker in a Ca(2+)-dependent manner, and the agglutination could be inhibited by D-Mannose, D-Glucose, D-Fructose, α-Lactose, D-Maltose and LPS. Positive microbial agglutination activities of rLcNTC were observed against all tested bacteria in the presence of Ca(2+), including Gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus and Micrococcus lysoleikticus) and Gram-negative bacteria (E. coli, V. parahaemolyticus, Vibrio alginolyticus and Aeromonas hydrophila). These findings collectively indicated that LcNTC might be involved in the innate immunity of L. crocea as a PRR. Copyright © 2016 Elsevier Ltd. All rights

  3. Study of a large scale powdered activated carbon pilot: Removals of a wide range of emerging and priority micropollutants from wastewater treatment plant effluents.

    Science.gov (United States)

    Mailler, R; Gasperi, J; Coquet, Y; Deshayes, S; Zedek, S; Cren-Olivé, C; Cartiser, N; Eudes, V; Bressy, A; Caupos, E; Moilleron, R; Chebbo, G; Rocher, V

    2015-04-01

    The efficacy of a fluidized powdered activated carbon (PAC) pilot (CarboPlus(®)) was studied in both nominal (total nitrification + post denitrification) and degraded (partial nitrification + no denitrification) configuration of the Seine Centre WWTP (Colombes, France). In addition to conventional wastewater parameters 54 pharmaceuticals and hormones (PhPHs) and 59 other emerging pollutants were monitored in influents and effluents of the pilot. Thus, the impacts of the WWTP configuration, the process operation and the physico-chemical properties of the studied compounds were assessed in this article. Among the 26 PhPHs quantified in nominal WWTP configuration influents, 8 have high dissolved concentrations (>100 ng/L), 11 have an intermediary concentration (10-100 ng/L) and 7 are quantified below 10 ng/L. Sulfamethoxazole is predominant (about 30% of the sum of the PhPHs). Overall, 6 PhPHs are poorly to moderately removed (80%), i.e. beta blockers, carbamazepine or trimethoprim, and 11 are well eliminated (60-80%), i.e. diclofenac, naproxen or sulfamethoxazole. In degraded WWTP configuration, higher levels of organic matter and higher concentrations of most pollutants are observed. Consequently, most PhPHs are substantially less removed in percentages but the removed flux is higher. Thus, the PAC dose required to achieve a given removal percentage is higher in degraded WWTP configuration. For the other micropollutants (34 quantified), artificial sweeteners and phthalates are found at particularly high concentrations in degraded WWTP configuration influents, up to μg/L range. Only pesticides, bisphenol A and parabens are largely eliminated (50-95%), while perfluorinated acids, PAHs, triclosan and sweeteners are not or weakly removed (<50%). The remaining compounds exhibit a very variable fate from campaign to campaign. The fresh PAC dose was identified as the most influencing operation parameter and is strongly correlated to performances. Charge and

  4. Design of the multiwavelength Scophony infrared scene projector

    Science.gov (United States)

    Thompson, Kevin P.; Kircher, James R.; Marlow, Steven A.; Korniski, Ronald J.; Richwine, Robert A.

    1993-11-01

    An all acousto-optic infrared scene projector (IRSP) has been developed for use in evaluating thermal-imaging guidance systems at the Kinetic Kill Vehicle Hardware-in-the-Loop Simulator (KHILS) facility located at Elgin AFB, Florida. The IRSP is a laser source based projector incorporating Scophony illumination and scanning methods to produce 96 X 96 pixel multi-wavelength images at very high frame rates (400 Hz). The IRSP is composed of five functionally similar optical trains, four of which are fed with a different `color' infrared laser. The separate scenes from each optical train are then combined and projected simultaneously into the imaging guidance system.

  5. A unified multiwavelength model of galaxy formation

    Science.gov (United States)

    Lacey, Cedric G.; Baugh, Carlton M.; Frenk, Carlos S.; Benson, Andrew J.; Bower, Richard G.; Cole, Shaun; Gonzalez-Perez, Violeta; Helly, John C.; Lagos, Claudia D. P.; Mitchell, Peter D.

    2016-11-01

    We present a new version of the GALFORM semi-analytical model of galaxy formation. This brings together several previous developments of GALFORM into a single unified model, including a different initial mass function (IMF) in quiescent star formation and in starbursts, feedback from active galactic nuclei suppressing gas cooling in massive haloes, and a new empirical star formation law in galaxy discs based on their molecular gas content. In addition, we have updated the cosmology, introduced a more accurate treatment of dynamical friction acting on satellite galaxies, and updated the stellar population model. The new model is able to simultaneously explain both the observed evolution of the K-band luminosity function and stellar mass function, and the number counts and redshift distribution of sub-mm galaxies selected at 850 μm. This was not previously achieved by a single physical model within the Λcold dark matter framework, but requires having an IMF in starbursts that is somewhat top-heavy. The new model is tested against a wide variety of observational data covering wavelengths from the far-UV to sub-mm, and redshifts from z = 0 to 6, and is found to be generally successful. These observations include the optical and near-infrared (IR) luminosity functions, H I mass function, fraction of early type galaxies, Tully-Fisher, metallicity-luminosity and size-luminosity relations at z = 0, as well as far-IR number counts, and far-UV luminosity functions at z ˜ 3-6. Discrepancies are, however, found in galaxy sizes and metallicities at low luminosities, and in the abundance of low-mass galaxies at high-z, suggesting the need for a more sophisticated model of supernova feedback.

  6. Seasonality in cholera dynamics : a rainfall-driven model explains the wide range of patterns of an infectious disease in endemic areas

    Science.gov (United States)

    Baracchini, Theo; Pascual, Mercedes; King, Aaron A.; Bouma, Menno J.; Bertuzzo, Enrico; Rinaldo, Andrea

    2015-04-01

    An explanation for the spatial variability of seasonal cholera patterns has remained an unresolved problem in tropical medicine te{pascual_2002}. Previous studies addressing the role of climate drivers in disease dynamics have focused on interannual variability and modelled seasonality as given te{king_nature}. Explanations for seasonality have relied on complex environmental interactions that vary with spatial location (involving regional hydrological models te{bertuzzo_2012}, river discharge, sea surface temperature, and plankton blooms). Thus, no simple and unified theory based on local climate variables has been formulated te{emch_2008}, leaving our understanding of seasonal variations of cholera outbreaks in different regions of the world incomplete. Through the analysis of a unique historical dataset containing 50 years of monthly meteorological, demographic and epidemiological records, we propose a mechanistic, SIR-based stochastic model for the population dynamics of cholera driven by local rainfall and temperature that is able to capture the full range of seasonal patterns in this large estuarine region, which encompasses the variety of patterns worldwide. Parameter inference was implemented via new statistical methods that allow the computation of maximum-likelihood estimates for partially observed Markov processes through sequential Monte-Carlo te{ionides_2011}. Such a model may provide a unprecedented opportunity to gain insights on the conditions and factors responsible for endemicity around the globe, and therefore, to also revise our understanding of the ecology of Vibrio cholerae. Results indicate that the hydrological regime is a decisive driver determining the seasonal dynamics of cholera. It was found that rainfall and longer water residence times tend to buffer the propagation of the disease in wet regions due to a dilution effect, while also enhancing cholera incidence in dry regions. This indicates that overall water levels matter and appear

  7. Multiwavelength FLIM: new applications and algorithms

    Science.gov (United States)

    Rück, A.; Strat, D.; Dolp, F.; von Einem, B.; von Arnim, C. A. F.

    2011-03-01

    The combination of time-resolved and spectral resolved techniques as achieved by SLIM (spectrally resolved fluorescence lifetime imaging) improves the analysis of complex situations, when different fluorophores have to be distinguished. This could be the case when endogenous fluorophores of living cells and tissues are observed to identify the redox state and oxidative metabolic changes of the mitochondria. Other examples are FRET (resonant energy transfer) measurements, when different donor/acceptor pairs are observed simultaneously. SLIM is working in the time domain employing excitation with short light pulses and detection of the fluorescence intensity decay in many cases with time-correlated single photon counting (TCSPC). Spectral resolved detection is achieved by a polychromator in the detection path and a 16-channel multianode photomultiplier tube with the appropriate routing electronics. Within this paper special attention will be focused on FRET measurements with respect to protein interactions in Alzheimers disease. Using global analysis as the phasor plot approach or integration of the kinetic equations taking into account the multidimensional datasets in every spectral channel we could demonstrate considerable improvement of our calculations.

  8. Convolution kernels for multi-wavelength imaging

    Science.gov (United States)

    Boucaud, A.; Bocchio, M.; Abergel, A.; Orieux, F.; Dole, H.; Hadj-Youcef, M. A.

    2016-12-01

    Astrophysical images issued from different instruments and/or spectral bands often require to be processed together, either for fitting or comparison purposes. However each image is affected by an instrumental response, also known as point-spread function (PSF), that depends on the characteristics of the instrument as well as the wavelength and the observing strategy. Given the knowledge of the PSF in each band, a straightforward way of processing images is to homogenise them all to a target PSF using convolution kernels, so that they appear as if they had been acquired by the same instrument. We propose an algorithm that generates such PSF-matching kernels, based on Wiener filtering with a tunable regularisation parameter. This method ensures all anisotropic features in the PSFs to be taken into account. We compare our method to existing procedures using measured Herschel/PACS and SPIRE PSFs and simulated JWST/MIRI PSFs. Significant gains up to two orders of magnitude are obtained with respect to the use of kernels computed assuming Gaussian or circularised PSFs. A software to compute these kernels is available at https://github.com/aboucaud/pypher

  9. Multi-wavelength fluorometry for anaerobic digestion process monitoring.

    Science.gov (United States)

    Morel, E; Santamaria, K; Perrier, M; Guiot, S R; Tartakovsky, B

    2005-01-01

    Applicability of multi-wavelength fluorometry for anaerobic digestion process monitoring was investigated in a 3.5 L upflow anaerobic sludge bed (UASB) lab-scale reactor. Both off-line and on-line monitoring of key process parameters was tested. Off-line emission spectra were measured at an angle of 90 degrees to the excitation beam using a cuvette. On-line measurements were carried out using a fiber optic probe in the external recirculation line of the digester. Fluorescence spectra were correlated to available analytical measurements to obtain partial least square regression models. An independent set of measurements was used to validate the regression models. Model estimations showed reasonable agreement with analytical measurements with multiple determination coefficients (R2) between 0.6 and 0.95. Results showed that offline fluorescence measurements can be used for fast estimation of anaerobic digestor effluent quality. At the same time, the on-line implementation of multi-wavelength fluorescence measurements can be used for realtime process monitoring and, potentially, for on-line process control.

  10. Jet evolution in Steep Spectrum Radio Quasars: a multiwavelength study

    Directory of Open Access Journals (Sweden)

    Torresi Eleonora

    2013-12-01

    Full Text Available Thanks to the Fermi γ-ray satellite, it is now confirmed that Misaligned Active Galactic Nuclei (MAGN, i.e. radio galaxies and steep spectrum radio quasars, are a new class of GeV emitters. In this work we present the first γ-ray and multiwavelength study of the two steep spectrum radio quasars, i.e. 3C 207 and 3C 380, belonging to the MAGN sample. From the γ -ray variability study we estimate the physical size of the zone where high-energy photons are dissipated: for both sources this region should be very compact, not larger than 0.05 pc. As a successive step, we build multiwavelength light curves of 3C 207 and 3C 380 to search for possible simultaneous outbursts in different wavebands with the aim of localizing the compact emitting region. This is an important issue with strong impact on theoretical models: indeed, knowing where highenergy photons are dissipated (at sub-pc or pc-scale provides information on the nature of the seed photons involved in the production of the GeV radiation.

  11. Controlling a wide range of flow rates

    Science.gov (United States)

    Perkins, G. S.

    1979-01-01

    Servo-operated valve and two flowmeters allow accurate control over 1,900:1 flow-rate range. It was developed as part of laboratory instrument for measuring properties of confined fluids under conditions analogous to those encountered in deep drilling operations.

  12. Multi-wavelength photoacoustic imaging for monitoring lesion formation during high-intensity focused ultrasound therapy

    Science.gov (United States)

    Wu, Xun; Sanders, Jean; Dundar, Murat; Oralkan, Ömer

    2017-03-01

    Photoacoustic imaging (PAI) can be used to monitor lesion formation during high-intensity focused ultrasound (HIFU) therapy because HIFU changes the optical absorption spectrum (OAS) of the tissue. However, in traditional PAI, the change could be too subtle to be observed either because the OAS does not change very significantly at the imaging wavelength or due to low signal-to-noise ratio in general. We propose a machine-learning-based method for lesion monitoring with multi-wavelength PAI (MWPAI), where PAI is repeated at a sequence of wavelengths and a stack of multi-wavelength photoacoustic (MWPA) images is acquired. Each pixel is represented by a vector and each element in the vector reflects the optical absorption at the corresponding wavelength. Based on the MWPA images, a classifier is trained to classify pixels into two categories: ablated and non-ablated. In our experiment, we create a lesion on a block of bovine tissue with a HIFU transducer, followed by MWPAI in the 690 nm to 950 nm wavelength range, with a step size of 5 nm. In the MWPA images, some of the ablated and non-ablated pixels are cropped and fed to a neural network (NN) as training examples. The NN is then applied to several groups of MWPA images and the results show that the lesions can be identified clearly. To apply MWPAI in/near real-time, sequential feature selection is performed and the number of wavelengths is decreased from 53 to 5 while retaining adequate performance. With a fast-switching tunable laser, the method can be implemented in/near real-time.

  13. Observation

    Science.gov (United States)

    Kripalani, Lakshmi A.

    2016-01-01

    The adult who is inexperienced in the art of observation may, even with the best intentions, react to a child's behavior in a way that hinders instead of helping the child's development. Kripalani outlines the need for training and practice in observation in order to "understand the needs of the children and...to understand how to remove…

  14. First multi-wavelength campaign on the gamma-ray-loud active galaxy IC 310

    Science.gov (United States)

    Ahnen, M. L.; Ansoldi, S.; Antonelli, L. A.; Arcaro, C.; Babić, A.; Banerjee, B.; Bangale, P.; Barres de Almeida, U.; Barrio, J. A.; Becerra González, J.; Bednarek, W.; Bernardini, E.; Berti, A.; Biasuzzi, B.; Biland, A.; Blanch, O.; Bonnefoy, S.; Bonnoli, G.; Borracci, F.; Bretz, T.; Carosi, R.; Carosi, A.; Chatterjee, A.; Colin, P.; Colombo, E.; Contreras, J. L.; Cortina, J.; Covino, S.; Cumani, P.; Da Vela, P.; Dazzi, F.; De Angelis, A.; De Lotto, B.; de Oña Wilhelmi, E.; Di Pierro, F.; Doert, M.; Domínguez, A.; Dominis Prester, D.; Dorner, D.; Doro, M.; Einecke, S.; Eisenacher Glawion, D.; Elsaesser, D.; Engelkemeier, M.; Fallah Ramazani, V.; Fernández-Barral, A.; Fidalgo, D.; Fonseca, M. V.; Font, L.; Fruck, C.; Galindo, D.; García López, R. J.; Garczarczyk, M.; Gaug, M.; Giammaria, P.; Godinović, N.; Gora, D.; Guberman, D.; Hadasch, D.; Hahn, A.; Hassan, T.; Hayashida, M.; Herrera, J.; Hose, J.; Hrupec, D.; Hughes, G.; Idec, W.; Ishio, K.; Kodani, K.; Konno, Y.; Kubo, H.; Kushida, J.; Lelas, D.; Lindfors, E.; Lombardi, S.; Longo, F.; López, M.; Majumdar, P.; Makariev, M.; Mallot, K.; Maneva, G.; Manganaro, M.; Mannheim, K.; Maraschi, L.; Mariotti, M.; Martínez, M.; Mazin, D.; Menzel, U.; Mirzoyan, R.; Moralejo, A.; Moretti, E.; Nakajima, D.; Neustroev, V.; Niedzwiecki, A.; Nievas Rosillo, M.; Nilsson, K.; Nishijima, K.; Noda, K.; Nogués, L.; Nöthe, M.; Paiano, S.; Palacio, J.; Palatiello, M.; Paneque, D.; Paoletti, R.; Paredes, J. M.; Paredes-Fortuny, X.; Pedaletti, G.; Peresano, M.; Perri, L.; Persic, M.; Poutanen, J.; Prada Moroni, P. G.; Prandini, E.; Puljak, I.; Garcia, J. R.; Reichardt, I.; Rhode, W.; Ribó, M.; Rico, J.; Saito, T.; Satalecka, K.; Schroeder, S.; Schweizer, T.; Shore, S. N.; Sillanpää, A.; Sitarek, J.; Snidaric, I.; Sobczynska, D.; Stamerra, A.; Strzys, M.; Surić, T.; Takalo, L.; Tavecchio, F.; Temnikov, P.; Terzić, T.; Tescaro, D.; Teshima, M.; Torres, D. F.; Torres-Albà, N.; Toyama, T.; Treves, A.; Vanzo, G.; Vazquez Acosta, M.; Vovk, I.; Ward, J. E.; Will, M.; Wu, M. H.; Krauß, F.; Schulz, R.; Kadler, M.; Wilms, J.; Ros, E.; Bach, U.; Beuchert, T.; Langejahn, M.; Wendel, C.; Gehrels, N.; Baumgartner, W. H.; Markwardt, C. B.; Müller, C.; Grinberg, V.; Hovatta, T.; Magill, J.

    2017-07-01

    Context. The extragalactic very-high-energy gamma-ray sky is rich in blazars. These are jetted active galactic nuclei that are viewed at a small angle to the line-of-sight. Only a handful of objects viewed at a larger angle are so far known to emit above 100 GeV. Multi-wavelength studies of such objects up to the highest energies provide new insights into the particle and radiation processes of active galactic nuclei. Aims: We aim to report the results from the first multi-wavelength campaign observing the TeV detected nucleus of the active galaxy IC 310, whose jet is observed at a moderate viewing angle of 10°-20°. Methods: The multi-instrument campaign was conducted between 2012 November and 2013 January, and involved observations with MAGIC, Fermi, INTEGRAL, Swift, OVRO, MOJAVE and EVN. These observations were complemented with archival data from the AllWISE and 2MASS catalogs. A one-zone synchrotron self-Compton model was applied to describe the broadband spectral energy distribution. Results: IC 310 showed an extraordinary TeV flare at the beginning of the campaign, followed by a low, but still detectable TeV flux. Compared to previous measurements in this energy range, the spectral shape was found to be steeper during the low emission state. Simultaneous observations in the soft X-ray band showed an enhanced energy flux state and a harder-when-brighter spectral shape behavior. No strong correlated flux variability was found in other frequency regimes. The broadband spectral energy distribution obtained from these observations supports the hypothesis of a double-hump structure. Conclusions: The harder-when-brighter trend in the X-ray and VHE emission, observed for the first time during this campaign, is consistent with the behavior expected from a synchrotron self-Compton scenario. The contemporaneous broadband spectral energy distribution is well described with a one-zone synchrotron self-Compton model using parameters that are comparable to those found for

  15. Multi-wavelength studies of accretion phenomena with SALT and ASTROSAT

    Science.gov (United States)

    Buckley, David A. H.; Pal Singh, Kulinder

    The Southern African Large Telescope (SALT) is a 10-m ground-based optical-IR telescope which has a range of instrumentation ideally suited to observe a variety of phenomena in astrophysical objects powered by accretion, from binary stellar systems (involving white dwarfs, neutron stars and black holes), to Active Galactic Nuclei. SALT's observational capabilities include time resolved optical photometry, spectroscopy and polarimetry, down to sub-second time resolution. ASTROSAT will be India's first astronomy satellite and will carry an array of instruments capable of simultaneous observations in a broad range of wavelengths: from the visible, near ultraviolet (NUV), far-UV (FUV), soft X-rays to hard X-rays. We plan to harness the capabilities of both observatories to undertake contemporaneous multi-wavelength observations of the various classes of accretion driven variable X-ray sources. By observing in both the optical (SALT), ultraviolet and X-ray regimes (ASTROSAT), we will correlate the spectral energy distributions, fluxes and spectral variations for a variety of objects.

  16. The status of MUSIC: the multiwavelength sub-millimeter inductance camera

    Science.gov (United States)

    Sayers, Jack; Bockstiegel, Clint; Brugger, Spencer; Czakon, Nicole G.; Day, Peter K.; Downes, Thomas P.; Duan, Ran P.; Gao, Jiansong; Gill, Amandeep K.; Glenn, Jason; Golwala, Sunil R.; Hollister, Matthew I.; Lam, Albert; LeDuc, Henry G.; Maloney, Philip R.; Mazin, Benjamin A.; McHugh, Sean G.; Miller, David A.; Mroczkowski, Anthony K.; Noroozian, Omid; Nguyen, Hien Trong; Schlaerth, James A.; Siegel, Seth R.; Vayonakis, Anastasios; Wilson, Philip R.; Zmuidzinas, Jonas

    2014-08-01

    The Multiwavelength Sub/millimeter Inductance Camera (MUSIC) is a four-band photometric imaging camera operating from the Caltech Submillimeter Observatory (CSO). MUSIC is designed to utilize 2304 microwave kinetic inductance detectors (MKIDs), with 576 MKIDs for each observing band centered on 150, 230, 290, and 350 GHz. MUSIC's field of view (FOV) is 14' square, and the point-spread functions (PSFs) in the four observing bands have 45'', 31'', 25'', and 22'' full-widths at half maximum (FWHM). The camera was installed in April 2012 with 25% of its nominal detector count in each band, and has subsequently completed three short sets of engineering observations and one longer duration set of early science observations. Recent results from on-sky characterization of the instrument during these observing runs are presented, including achieved map- based sensitivities from deep integrations, along with results from lab-based measurements made during the same period. In addition, recent upgrades to MUSIC, which are expected to significantly improve the sensitivity of the camera, are described.

  17. On-sky results of the ZEUS phasing sensor, closed-loop precision in the context of multi-wavelength measurements

    Science.gov (United States)

    Vigan, A.; Dohlen, K.; Surdej, I.; Yaitskova, N.; Gonte, F.

    2010-07-01

    The Active Phasing Experiment (APE) was designed to test four different phasing techniques and to validate wavefront control concepts for Extremely Large Telescopes. One of the sensors is the ZErnike Unit for Segment phasing (ZEUS), which was successfully tested on-sky along with the rest of the APE experiment at one of the Nasmyth platforms of the Very Large Telescope (VLT) in 2009. During the four observing campaigns, multiple results were obtained in open-loop and in closed-loop at different wavelengths. We present in this paper an analysis of the multi-wavelength data in terms of piston measurement precision at the edges of the segments and on the reconstructed wavefront, and an analysis of the evolution of these errors in successive closed-loop runs at different wavelengths. This work demonstrates how the applied multi-wavelength algorithm leads to convergence, allowing phasing of segments with piston errors of several microns.

  18. Multi-wavelength VCSEL arrays using high-contrast gratings

    Science.gov (United States)

    Haglund, Erik; Gustavsson, Johan S.; Sorin, Wayne V.; Bengtsson, Jörgen; Fattal, David; Haglund, Àsa; Tan, Michael; Larsson, Anders

    2017-02-01

    The use of a high-contrast grating (HCG) as the top mirror in a vertical-cavity surface-emitting laser (VCSEL) allows for setting the resonance wavelength by the grating parameters in a post-epitaxial growth fabrication process. Using this technique, we demonstrate electrically driven multi-wavelength VCSEL arrays at 980 nm wavelength. The VCSELs are GaAs-based and the suspended GaAs HCGs were fabricated using electron-beam lithography, dry etching and selective removal of an InGaP sacrificial layer. The air-coupled cavity design enabled 4-channel arrays with 5 nm wavelength spacing and sub-mA threshold currents thanks to the high HCG reflectance.

  19. Compact, Wavelength Stabilized Seed Source for Multi-Wavelength Lidar Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA LaRC is developing a compact, multi-wavelength High Spectral resolution Lidar (HSRL) system designed to measure various optical and microphysical properties of...

  20. Electron-impact rotationally elastic total cross sections for H{sub 2}CO and HCOOH over a wide range of incident energy (0.01-2000 eV)

    Energy Technology Data Exchange (ETDEWEB)

    Vinodkumar, Minaxi [V P and R P T P Science College, Vallabh Vidyanagar 388 120, Gujarat (India); Bhutadia, Harshad [Government Engineering College, Patan 384265, Gujarat (India); Antony, Bobby [Department of Applied Physics, Indian School of Mines, Dhanbad JH-826004 (India); Mason, Nigel [Department of Physics and Astronomy, Open University, Milton Keynes MK7 6AA (United Kingdom)

    2011-11-15

    This paper reports computational results of the total cross sections for electron impact on H{sub 2}CO and HCOOH over a wide range of electron impact energies from 0.01 eV to 2 keV. The total cross section is presented as sum of the elastic and electronic excitation cross sections for incident energies. The calculation uses two different methodologies, below the ionization threshold of the target the cross section is calculated using the UK molecular R-matrix code through the Quantemol-N software package while cross sections at higher energies are evaluated using the spherical complex optical potential formalism. The two methods are found to be consistent at the transition energy ({approx}15 eV). The present results are, in general, found to be in good agreement with previous experimental and theoretical results (wherever available) and, thus, the present results can serve as a benchmark for the cross section over a wide range of energy.

  1. Constitutive modelling of CK45N, AlZnMgCu1.5 and Ti-6Al-4V in a wide range of strain rate and temperature

    Science.gov (United States)

    El-Magd, E.; Treppmann, C.; Korthäuer, M.

    2003-09-01

    Continuous constitutive equations for wide ranges of strain rates and temperatures are gaining increasing importance for adequate simulation of dynamic deformation processes. The flow behaviour of the carbon steel CK45N, the Aluminium Alloy AIZnMgCul.5 and the Titanium Alloy Ti6A14V is studied at different strain rates between 0.001 s^{-1} and 10000 s^{-1} with temperatures varying between 23^{circ}C and 1000^{circ}C at CK45N and Ti6A14V. AIZnMgCul.5 was investigated in a temperature range from 23^{circ}C up to 500^{circ}C. The mechanical behaviour of the three materials over this wide range needs the consideration of different physical deformation mechanisms. In the range of high temperatures and low strain rates stress relaxation due to creep deformation processes are superimposed to the plastic deformation process with a relatively low strain rate sensitivity and temperature dependence. In the range of high strain rates, the damping controlled deformation mechanism is additionally active leading to a high increase of the strain rate sensitivity. In case of steel, a dynamic age hardening mechanism is superimposed causing a stress increase between 300^{circ}C and 600^{circ}C according to strain rate. The correlation between the material parameters and the instability, localisation and damage is studied on the bases of simple models.

  2. Multi-wavelength polarimetric studies of relativistic jets in active galactic nuclei

    Science.gov (United States)

    Casadio, Carolina

    This Thesis is focussed on the study of relativistic jets, commonly present in multiple astrophysical sites, from active galactic nuclei (AGN), to micro- quasars or gamma-ray bursts (GRBs). In the case of AGN, huge amounts of energy across the whole electromagnetic spectrum are released as a conse- quence of the accretion of material onto a supermassive back hole (SMBH) lurking at their centers. The accretion leads to the formation of a pair of very powerful and highly collimated jets extending far beyond the size of the host galaxy. We analyzed the correlation between the multi-wavelength emission and the radio jet in three powerful AGN, the radio galaxies 3C 120 and M 87, and the quasar CTA 102. The main goal of this Thesis is to obtain a better understanding of the jet dynamics and the role played by the magnetic field, and to determine what are the sites and mechanisms for the production of the γ-ray emission observed in these sources. We have performed multi-wavelength studies of the radio galaxy 3C 120 and the blazar CTA 102 during unprecedented γ-ray flares for both sources. The NASA satellite Fermi registered in September-October 2012 a bright γ-ray flare in CTA 102, and between December 2012 and October 2014 a prolonged γ-ray activity in the radio galaxy 3C 120. In both studies, to determine where the γ-ray emission is produced, the analysis of Fermi data has been compared with a detailed study of the morphology and evolution of the parsec scale jet through a series of extremely-high angular resolution Very Long Baseline Array (VLBA) images at 43 GHz from the Boston University blazar monitoring program, in which our research group is actively participating. In the case of 3C 120 we have also collected 15 GHz VLBA data from the MOJAVE monitoring program, extending our study of the radio jet from June 2008 to May 2014. For the study of CTA 102 a total of 80 VLBA images at 43 GHz have been analyzed and compared with observations across the whole

  3. Target categorization of aerosol and clouds by continuous multiwavelength-polarization lidar measurements

    Directory of Open Access Journals (Sweden)

    H. Baars

    2017-09-01

    Full Text Available Absolute calibrated signals at 532 and 1064 nm and the depolarization ratio from a multiwavelength lidar are used to categorize primary aerosol but also clouds in high temporal and spatial resolution. Automatically derived particle backscatter coefficient profiles in low temporal resolution (30 min are applied to calibrate the lidar signals. From these calibrated lidar signals, new atmospheric parameters in temporally high resolution (quasi-particle-backscatter coefficients are derived. By using thresholds obtained from multiyear, multisite EARLINET (European Aerosol Research Lidar Network measurements, four aerosol classes (small; large, spherical; large, non-spherical; mixed, partly non-spherical and several cloud classes (liquid, ice are defined. Thus, particles are classified by their physical features (shape and size instead of by source. The methodology is applied to 2 months of continuous observations (24 h a day, 7 days a week with the multiwavelength-Raman-polarization lidar PollyXT during the High-Definition Clouds and Precipitation for advancing Climate Prediction (HD(CP2 Observational Prototype Experiment (HOPE in spring 2013. Cloudnet equipment was operated continuously directly next to the lidar and is used for comparison. By discussing three 24 h case studies, it is shown that the aerosol discrimination is very feasible and informative and gives a good complement to the Cloudnet target categorization. Performing the categorization for the 2-month data set of the entire HOPE campaign, almost 1 million pixel (5 min  ×  30 m could be analysed with the newly developed tool. We find that the majority of the aerosol trapped in the planetary boundary layer (PBL was composed of small particles as expected for a heavily populated and industrialized area. Large, spherical aerosol was observed mostly at the top of the PBL and close to the identified cloud bases, indicating the importance of hygroscopic growth of the

  4. Multiwavelength modeling the SED of supersoft X-ray sources. II. RS Ophiuchi: From the explosion to the SSS phase

    Science.gov (United States)

    Skopal, A.

    2015-04-01

    RS Oph is a recurrent symbiotic nova that undergoes nova-like outbursts on a time scale of 20 yr. Its two last eruptions (1985 and 2006) were subject of intensive multiwavelengths observational campaign from the X-rays to the radio. This contribution aims to determine physical parameters and the ionization structure of the nova from its explosion to the first emergence of the supersoft X-rays (day 26) by using the method of multiwavelength modeling the SED. From the very beginning of the eruption, the model SED revealed the presence of both a strong stellar and nebular component of radiation in the spectrum. During the first 4 days, the nova evinced a biconical ionization structure. The ∼8200 K warm and 160-200 R⊙ extended pseudophotosphere encompassed the white dwarf (WD) around its equator to the latitude > 40 ° . The remaining space around the WD's poles was ionized, producing a strong nebular continuum with the emission measure EM ∼ 2.3 ×1062 cm-3 via the fast wind from the WD. The luminosity of the burning WD was highly super-Eddington for the whole investigated period. The wind mass loss at rates of 10-4-10-5M⊙yr-1 and the presence of jets suggest an accretion throughout a disk at a high rate, which can help to sustain the super-Eddington luminosity of the accretor for a long time.

  5. Retrieval of spatio-temporal distributions of particle parameters from multiwavelength lidar measurements using the linear estimation technique and comparison with AERONET

    Directory of Open Access Journals (Sweden)

    I. Veselovskii

    2013-10-01

    Full Text Available The results of the application of the linear estimation technique to multiwavelength Raman lidar measurements performed during the summer of 2011 in Greenbelt, MD, USA, are presented. We demonstrate that multiwavelength lidars are capable not only of providing vertical profiles of particle properties but also of revealing the spatio-temporal evolution of aerosol features. The nighttime 3β + 1α lidar measurements on 21 and 22 July were inverted to spatio-temporal distributions of particle microphysical parameters, such as volume, number density, effective radius and the complex refractive index. The particle volume and number density show strong variation during the night, while the effective radius remains approximately constant. The real part of the refractive index demonstrates a slight decreasing tendency in a region of enhanced extinction coefficient. The linear estimation retrievals are stable and provide time series of particle parameters as a function of height at 4 min resolution. AERONET observations are compared with multiwavelength lidar retrievals showing good agreement.

  6. The Peculiar Binary System AE Aquarii from its Characteristic Multi-wavelength Emission

    Directory of Open Access Journals (Sweden)

    Oruru B.

    2014-01-01

    Full Text Available The multi-wavelength properties of the novalike variable system AE Aquarii are discussed in terms of the interaction between the accretion inflow from a late-type main sequence star and the magnetosphere of a fast rotating white dwarf. This results in an efficient magnetospheric propeller process and particle acceleration. The spin-down of the white dwarf at a period rate of 5.64×10−14 s s−1 results in a huge spin-down luminosity of Ls−d ≃ 6 10×33 erg s−1. Hence, the observed non-thermal hard X-ray emission and VHE and TeV gamma-ray emission may suggest that AE Aquarii can be placed in the category of spin-powered pulsars. Besides, observed hard X-ray luminosity of LX,hard ≤ 5 × 1030 erg s−1 constitutes 0.1 % of the total spin-down luminosity of the white dwarf. This paper will discuss some recent theoretical studies and data analysis of the system.

  7. Use of a Multiwavelength Pyrometer in Several Elevated Temperature Aerospace Applications

    Science.gov (United States)

    Ng, Daniel; Fralick, Gustave

    2001-01-01

    A multiwavelength pyrometer was developed for applications unique to aerospace environments. It was shown to be a useful and versatile technique for measuring temperature, even when the emissivity is unknown. It has also been used to measure the surface temperatures of ceramic zircomia thermal barrier coatings and alumina. The close agreement between pyrometer and thin film thermocouple temperatures provided an independent check. Other applications of the multiwavelength pyrometer are simultaneous surface and bulk temperature measurements of a transparent material, and combustion gas temperature measurement using a special probe interfaced to the multiwavelength pyrometer via an optical fiber. The multiwavelength pyrometer determined temperature by transforming the radiation spectrum in a broad wavelength region to produce a straight line (in a certain spectral region), whose intercept in the vertical axis gives the temperature. Implicit in a two-color pyrometer is the assumption of wavelength independent emissivity. Though the two data points of a two-color pyrometer similarly processed would result immediately in a similar straight line to give the unknown temperature, the two-color pyrometer lacks the greater data redundancy of the multiwavelength pyrometer, which enables it to do so with improved accuracy. It also confirms that emissivity is indeed wavelength independent, as evidenced by a multitude of the data lying on a simple straight line. The multiwavelength pyrometer was also used to study the optical transmission properties of a nanostructured material from which a quadratic exponential functional frequency dependence of its spectral transmission was determined. Finally, by operating the multiwavelength pyrometer in a very wide field of view mode, the surface temperature distribution of a large hot surface was obtained through measurement of just a single radiation spectrum.

  8. Multi-wavelength Polarimetry and Spectral Study of the M87 Jet During 2002-2008

    Science.gov (United States)

    Avachat, Sayali S.; Perlman, Eric S.; Adams, Steven C.; Cara, Mihai; Owen, Frazer; Sparks, William B.; Georganopoulos, Markos

    2016-11-01

    We present a multi-wavelength polarimetric and spectral study of the M87 jet obtained at sub-arcsecond resolution between 2002 and 2008. The observations include multi-band archival VLA polarimetry data sets along with Hubble Space Telescope (HST) imaging polarimetry. These observations have better angular resolution than previous work by factors of 2-3 and in addition, allow us to explore the time domain. These observations envelop the huge flare in HST-1 located 0.″86 from the nucleus. The increased resolution enables us to view more structure in each knot, showing several resolved sub-components. We also see apparent helical structure in the polarization vectors in several knots, with polarization vectors turning either clockwise or counterclockwise near the flux maxima in various places as well as showing filamentary undulations. Some of these characteristics are correlated with flux and polarization maxima while others are not. We also examine the total flux and fractional polarization and look for changes in both radio and optical since the observations of Perlman et al. (1999) and test them against various models based on shocks and instabilities in the jet. Our results are broadly consistent with previous spine-sheath models and recollimation shock models; however, they require additional combinations of features to explain the observed complexity, e.g., shearing of magnetic field lines near the jet surface and compression of the toroidal component near shocks. In particular, in many regions we find apparently helical features both in total flux and polarization. We discuss the physical interpretation of these features. Based on the observations made with the Karl G. Jansky Very Large Array (VLA), operated by the National Radio Astronomy Observatory (NRAO), and Hubble Sapce Telescope (HST), obtained at the Space Telescope Science Institute (STScI), which is operated by the Association of Universities for Research in Astronomy, Inc.

  9. Characterization of Red Blood Cells with Multiwavelength Transmission Spectroscopy

    Directory of Open Access Journals (Sweden)

    Yulia M. Serebrennikova

    2015-01-01

    Full Text Available Multiwavelength transmission (MWT spectroscopy was applied to the investigation of the morphological parameters and composition of red blood cells (RBCs. The MWT spectra were quantitatively analyzed with a Mie theory based interpretation model modified to incorporate the effects of the nonsphericity and orientation of RBCs. The MWT spectra of the healthy and anemic samples were investigated for the RBC indices in open and blinded studies. When MWT performance was evaluated against a standard reference system, very good agreement between two methods, with R2>0.85 for all indices studied, was demonstrated. The RBC morphological parameters were used to characterize three types of anemia and to draw an association between RBC morphology and anemia severity. The MWT spectra of RBCs infected with malaria parasite Plasmodium falciparum at different life cycle stages were analyzed for RBC morphological parameters. The changes in the RBC volume, surface area, aspect ratio, and hemoglobin composition were used to trace the morphological and compositional alterations in the infected RBCs occurring with parasites’ development and to provide insights into parasite-host interactions. The MWT method was shown to be reliable for determination of the RBC morphological parameters and to be valuable for identification of the RBC pathologic changes and disease states.

  10. A Multi-wavelength Ozone Lidar for the EASOE Experiment

    Science.gov (United States)

    Godin, S.; Ancellet, G.; David, C.; Porteneuve, J.; Leroy, C.; Mitev, V.; Emery, Y.; Flesia, C.; Rizi, V.; Visconti, G.

    1992-01-01

    The study of the ozone layer during winter and springtime in high latitude regions is a major issue in atmospheric research. For a better understanding of these problems, an important experimental campaign called EASOE (European Arctic Stratospheric Ozone Experiment) was organized by the European Community during the winter 1991-1992. Its main objective was to establish a budget of the ozone destruction processes on the whole northern hemisphere. This implied the simultaneous operation of different types of instruments located in both high and mid-latitude regions in order to study the destruction processes as well as the evolution of the ozone layer during the period of the campaign. A description will be given here of a mobile ozone lidar instrument specially designed for operation during the EASOE campaign. This system, which performs ozone measurements in the 5 to 40 km altitude range was located in Sodankyla, Finland as part of the ELSA experiment which also includes operation of another multi-wavelength lidar designed for polar stratospheric cloud measurements.

  11. Multi-wavelength high efficiency laser system for lidar applications

    Science.gov (United States)

    Willis, Christina C. C.; Culpepper, Charles; Burnham, Ralph

    2015-09-01

    Motivated by the growing need for more efficient, high output power laser transmitters, we demonstrate a multi-wavelength laser system for lidar-based applications. The demonstration is performed in two stages, proving energy scaling and nonlinear conversion independently for later combination. Energy scaling is demonstrated using a 1064 nm MOPA system which employs two novel ceramic Nd:YAG slab amplifiers, the structure of which is designed to improve the amplifier's thermal performance and energy extraction via three progressive doping stages. This structure improved the extraction efficiency by 19% over previous single-stage dopant designs. A maximum energy of 34 mJ was produced at 500 Hz with a 10.8 ns pulse duration. High efficiency non-linear conversion from 1064 nm to 452 nm is demonstrated using a KTP ring OPO with a BBO intra-cavity doubler pumped with 50 Hz, 16 ns 1064 nm pulses. The OPO generates 1571 nm signal which is frequency doubled to 756 nm by the BBO. Output 786 nm pulses are mixed with the 1064 nm pump pulses to generate 452 nm. A conversion efficiency of 17.1% was achieved, generating 3 mJ of 452 nm pulses of 7.8 ns duration. Pump power was limited by intra-cavity damage thresholds, and in future experiments we anticipate >20% conversion efficiency.

  12. A multiwavelength study of Swift GRB 060111B constraining the origin of its prompt optical emission

    Science.gov (United States)

    Stratta, G.; Pozanenko, A.; Atteia, J.-L.; Klotz, A.; Basa, S.; Gendre, B.; Verrecchia, F.; Boër, M.; Cutini, S.; Henze, M.; Holland, S.; Ibrahimov, M.; Ienna, F.; Khamitov, I.; Klose, S.; Rumyantsev, V.; Biryukov, V.; Sharapov, D.; Vachier, F.; Arnouts, S.; Perley, D. A.

    2009-09-01

    Context: The detection of bright optical emission measured with good temporal resolution during the prompt phase of GRB 060111Bmakes this GRB a rare event that is especially useful for constraining theories of the prompt emission. Aims: For this reason an extended multi-wavelength campaign was performed to further constrain the physical interpretation of the observations. Methods: In this work, we present the results obtained from our multi-wavelength campaign, as well as from the public Swift/BAT, XRT, and UVOT data. Results: We identified the host galaxy at R˜25 mag from deep R-band exposures taken 5 months after the trigger. Its featureless spectrum and brightness, as well as the non-detection of any associated supernova 16 days after the trigger, enabled us to constrain the distance scale of GRB 060111B11 within 0.4≤ z ≤3 in the most conservative case. The host galaxy spectral continuum is best fit with a redshift of z˜2, and other independent estimates converge to z˜1-2. From the analysis of the early afterglow SED, we find that non-negligible host galaxy dust extinction, in addition to the Galactic one, affects the observed flux in the optical regime. The extinction-corrected optical-to-gamma-ray SED during the prompt emission shows a flux density ratio Fγ/F_opt=10-2-10-4 with spectral index βγ,opt > βγ, strongly suggesting a separate origin of the optical and gamma-ray components. This result is supported by the lack of correlated behavior in the prompt emission light curves observed in the two energy domains. The temporal properties of the prompt optical emission observed during GRB 060111B11 and their similarities to other rapidly-observed events favor interpretation of this optical light as radiation from the reverse shock. Observations are in good agreement with theoretical expectations for a thick shell limit in slow cooling regime. The expected peak flux is consistent with the observed one corrected for the host extinction, likely

  13. Connections Between Jet Formation and Multiwavelength Spectral Evolution in Black Hole Transients

    Science.gov (United States)

    Kakemci, Emrah; Chun, Yoon-Young; Dincer, Tolga; Buxton, Michelle; Tomsick, John A.; Corbel, Stephane; Kaaret, Philip

    2011-01-01

    Multiwavelength observations are the key to understand conditions of jet formation in Galactic black hole transient (GBHT) systems. By studying radio and optical-infrared evolution of such systems during outburst decays, the compact jet formation can be traced. Comparing this with X-ray spectral and timing evolution we can obtain physical and geometrical conditions for jet formation, and study the contribution of jets to X-ray emission. In this work, first X-ray evolution - jet relation for XTE J1752-223 will be discussed. This source had very good coverage in X-rays, optical, infrared and radio. A long exposure with INTEGRAL also allowed us to study gamma-ray behavior after the jet turns on. We will also show results from the analysis of data from GX 339-4 in the hard state with SUZAKU at low flux levels. The fits to iron line fluorescence emission show that the inner disk radius increases by a factor of greater than 27 with respect to radii in bright states. This result, along with other disk radius measurements in the hard state will be discussed within the context of conditions for launching and sustaining jets.

  14. The multi-wavelength properties of faint submillimeter galaxies at 450 and 850um

    Science.gov (United States)

    Zavala, Jorge; Aretxaga, Itziar; Hughes, David; Dunlop, James; Michalowski, Michal; SCUBA-2 Cosmology Legacy Survey

    2017-01-01

    We present a multi-wavelength analysis for galaxies selected at 450 and 850um from the deepest SCUBA-2 observations in the EGS field. The median redshifts for the 450 and 850um samples are z~1.6 and z~2.2, respectively. However, the two populations have similar IR luminosities, SFR, and stellar masses, with mean values of ~1.5x10^12 L_sun, 150 M_sun/yr, and 9x10^10 M_sun, respectively. We find that most of our sources (>80%) lie in the high-mass end of the `main sequence' of star-forming galaxies. Exploring the IRX-beta relation we find that the most luminous galaxies are consistent with the Muerer law, while the less luminous galaxies are in better agreement with the SMC relation. Using the results of a two-dimensinal modelling of the HST H_160-band, we derive a median Sersic index of n=1.4 and a median half-light radius of ~4.8kpc for the whole sample. Based on a visual-like classification in the same band we find that the dominant component for most of the galaxies at all redshift is a disk, although there is a transition from irregular disks to disks with a spheroidal component from high to low redshift, which supports the scenario of SMGs as progenitors of present-day massive elliptical galaxies.

  15. Multi-wavelength injection seeded mid-infrared optical parametric oscillator for DIAL

    Energy Technology Data Exchange (ETDEWEB)

    Webb, M.S.; Stanion, K.B.; Deane, D.J. [and others

    1996-01-27

    We have constructed and fielded a multi-wavelength injection seeded mid-IR OPO source for DIAL. This OPO system was built for ground based remote sensing measurements of species with both broad (300 cm{sup -1}) and narrow absorption bandwidths (0.07 cm{sup -1} FWHM). The OPO utilizes a single frequency tunable diode laser for the injection seeded signal wavelength in the region from 6400 to 6700 cm{sup -1} and an angle phase-matched 5 cm LiNbO3 crystal to provide large tuning excursions on a slow time scale. The pump was a diode pumped Nd:YAG MOPA (9398 cm{sup -1}) running at 180 Hz. This pump source was repeatedly injection seeded with a different wavelength on each of film sequential shots forming a set of three pulses having wavelength separations on the order of 0.4 cm{sup -1} at a three color set repetition rate of 60 Hz. This combination of OPO signal and pump source produced a set of three time staggered idler wavelengths separated by 0.4 cm{sup -1} with the center wavelength tunable from 2700 to 3000 cm{sup -1}. This OPO system was used in field test experiments to detect the release of chemicals from a standoff distance of 3.3 Km. We present key OPO design criteria, performance data, and numerical simulations that agree with our observations of pump induced spectral impurities in the OPO output.

  16. HST/WFC3 Imaging and Multi-Wavelength Characterization of Edge-On Protoplanetary Disks

    Science.gov (United States)

    Gould, Carolina; Williams, Hayley; Duchene, Gaspard

    2017-10-01

    In recent years, the imaging detail in resolved protoplanetary disks has vastly improved and created a critical mass of objects to survey and compare properties, leading us to better understandings of system formation. In particular, disks with an edge-on inclination offer an important perspective, not only for the imaging convenience since the disk blocks stellar light, but scientifically an edge-on disk provides an otherwise impossible opportunity to observe vertical dust structure of a protoplanetary system. In this contribution, we compare seven HST-imaged edge-on protoplanetary disks in the Taurus, Chamaeleon and Ophiuchus star-forming regions, making note the variation in morphology (settled vs flared), dust properties revealed by multiwavelength color mapping, brightness variability over years timescales, and the presence in some systems of a blue-colored atmosphere far above the disk midplane. By using a uniform approach for their analysis, together these seven edge-on protoplanetary disk systems can give insights on evolutionary processes and inform future projects that explore this critical stage of planet formation.

  17. MULTI-WAVELENGTH POLARIMETRY AND SPECTRAL STUDY OF THE M87 JET DURING 2002–2008

    Energy Technology Data Exchange (ETDEWEB)

    Avachat, Sayali S.; Perlman, Eric S. [Department of Physics and Space Sciences, 150 W. University Boulevard, Florida Institute of Technology, Melbourne, FL 32901 (United States); Adams, Steven C. [Department of Physics and Astronomy, University of Georgia, Athens, GA, 30605 (United States); Cara, Mihai; Sparks, William B. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Owen, Frazer [National Radio Astronomy Observatory, Array Operations Center, P.O. Box O, 1003 Lopezville Road, Socorro, NM 87801-0387 (United States); Georganopoulos, Markos [Department of Physics, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250 (United States)

    2016-11-20

    We present a multi-wavelength polarimetric and spectral study of the M87 jet obtained at sub-arcsecond resolution between 2002 and 2008. The observations include multi-band archival VLA polarimetry data sets along with Hubble Space Telescope ( HST ) imaging polarimetry. These observations have better angular resolution than previous work by factors of 2–3 and in addition, allow us to explore the time domain. These observations envelop the huge flare in HST-1 located 0.″86 from the nucleus. The increased resolution enables us to view more structure in each knot, showing several resolved sub-components. We also see apparent helical structure in the polarization vectors in several knots, with polarization vectors turning either clockwise or counterclockwise near the flux maxima in various places as well as showing filamentary undulations. Some of these characteristics are correlated with flux and polarization maxima while others are not. We also examine the total flux and fractional polarization and look for changes in both radio and optical since the observations of Perlman et al. (1999) and test them against various models based on shocks and instabilities in the jet. Our results are broadly consistent with previous spine-sheath models and recollimation shock models; however, they require additional combinations of features to explain the observed complexity, e.g., shearing of magnetic field lines near the jet surface and compression of the toroidal component near shocks. In particular, in many regions we find apparently helical features both in total flux and polarization. We discuss the physical interpretation of these features.

  18. Silicon nanowire and carbon nanotube hybrid for room temperature multiwavelength light source.

    Science.gov (United States)

    Lo Faro, Maria Josè; D'Andrea, Cristiano; Messina, Elena; Fazio, Barbara; Musumeci, Paolo; Reitano, Riccardo; Franzò, Giorgia; Gucciardi, Pietro Giuseppe; Vasi, Cirino; Priolo, Francesco; Iacona, Fabio; Irrera, Alessia

    2015-11-23

    The realization of an innovative hybrid light source operating at room temperature, obtained by embedding a carbon nanotube (CNT) dispersion inside a Si nanowire (NW) array is reported. The NW/CNT system exhibits a peculiar photoluminescence spectrum, consisting of a wide peak, mainly observed in the visible range, due to quantum confined Si NWs, and of several narrower IR peaks, due to the different CNT chiralities present in the dispersion. The detailed study of the optical properties of the hybrid system evidences that the ratio between the intensity of the visible and the IR emissions can be varied within a wide range by changing the excitation wavelength or the CNT concentration; the conditions leading to the prevalence of one signal with respect to the other are identified. The multiplicity of emission spectra obtainable from this composite material opens new perspectives for Si nanostructures as active medium in light sources for Si photonics applications.

  19. Steady-State Equilibrium Phase Inversion Recovery ON-resonant Water Suppression (IRON) Magnetic Resonance Angiography in Conjunction with Superparamagnetic Nanoparticles. A Robust Technique for Imaging within a Wide Range of Contrast Agent Dosages

    Science.gov (United States)

    Gitsioudis, Gitsios; Stuber, Matthias; Arend, Ingolf; Thomas, Moritz; Yu, Jing; Hilbel, Thomas; Giannitsis, Evangelos; Katus, Hugo A.; Korosoglou, Grigorios

    2012-01-01

    Objectives To investigate the ability of inversion recovery ON-resonant water suppression (IRON) in conjunction with P904 (superparamagnetic nanoparticles which consisting of a maghemite core coated with a low-molecular-weight amino-alcohol derivative of glucose) to perform steady-state equilibrium phase magnetic resonance angiography (MRA) over a wide dose range. Materials and Methods Experiments were approved by the institutional animal care committee. Rabbits (n=12) were imaged at baseline and serially after the administration of 10 incremental dosages of 0.57–5.7 mgFe/Kg P904. Conventional T1-weighted and IRON MRA were obtained on a clinical 1.5-T scanner to image the thoracic and abdominal aorta, and peripheral vessels. Contrast-to-noise ratios (CNR) and vessel sharpness were quantified. Results Using IRON MRA, CNR and vessel sharpness progressively increased with incremental dosages of the contrast agent P904, exhibiting constantly higher contrast values than T1-weighted MRA over a very wide range of contrast agent doses (CNR of 18.8±5.6 for IRON versus 11.1±2.8 for T1-weighted MRA at 1.71 mgFe/kg, p=0.02 and 19.8±5.9 for IRON versus −0.8±1.4 for T1-weighted MRA at 3.99 mgFe/kg, p=0.0002). Similar results were obtained for vessel sharpness in peripheral vessels, (Vessel sharpness of 46.76±6.48% for IRON versus 33.20±3.53% for T1-weighted MRA at 1.71 mgFe/Kg, p=0.002, and of 48.66±5.50% for IRON versus 19.00±7.41% for T1-weighted MRA at 3.99 mgFe/Kg, p=0.003). Conclusion Our study suggests that quantitative CNR and vessel sharpness after the injection of P904 are consistently higher for IRON MRA when compared to conventional T1-weighted MRA. These findings apply for a wide range of contrast agent dosages. PMID:23418107

  20. Spitzer ToO observations of a short gamma-ray burst

    Science.gov (United States)

    Hurley, Kevin; Bloom, Joshua; Butler, Nathaniel; Falco, Emilio; Foley, Ryan; Granot, Jonathan; Kocevski, Daniel; Lee, William; Li, Weidong; Mahoney, William; Pahre, Michael; Panaitescu, Alin; Perley, Daniel; Prochaska, Jason; Ramirez-Ruiz, Enrico; Smith, Ian; Squires, Gordon

    2008-03-01

    An understanding of the origin of the short gamma-ray bursts remains an elusive and exciting pursuit. A great leap forward has been made over the past three years with the first rapid localizations and afterglow detections of such events, but follow-up has yet to reveal a detailed understanding of the progenitors and the nature of the afterglow light. We propose an ambitious multiwavelength approach to the problem, leveraging Spitzer with Chandra as well as numerous ground-based telescopes. By measuring the broad-band spectrum of the afterglow and any concurrent 'mini-supernova ' over a wide range of wavelengths at several epochs, we can distinguish between models proposed to explain this type of burst. We will constrain the energetics of the explosion and the short GRB bursting rate (an important number for gravitational wave observatories), and measure with unprecedented detail the stellar content of a short burst host galaxy. Given the high impact nature of these observations and the rarity of short bursts, we are requesting multiepoch Target of Opportunity observations on a single event in Cycle 5. The wavelengths observed by Spitzer, when used in coordination with these other instruments, can make a crucial contribution to understanding the nature of short duration GRBs, particularly by removing the degeneracies among the models due to dust extinction. This is a resubmission of our AO-4 ToO proposal, which has not been called yet. However, even if that observation is carried out, we are requesting an AO-5 observation, because so little is known about the short bursts that each new detection adds a very significant amount of information. Harvey Tananbaum has agreed to grant us Chandra ToO time through November 2008 (the end of Chandra AO-9) if Spitzer observations are carried out. Following that, we will submit a Chandra AO-10 proposal for ToO time; if warranted, we will request Chandra Director's Discretionary Time to support our Spitzer observations.

  1. A Large Catalog of Multiwavelength GRB Afterglows. I. Color Evolution and Its Physical Implication

    Science.gov (United States)

    Li, Liang; Wang, Yu; Shao, Lang; Wu, Xue-Feng; Huang, Yong-Feng; Zhang, Bing; Ryde, Felix; Yu, Hoi-Fung

    2018-02-01

    The spectrum of gamma-ray burst (GRB) afterglows can be studied with color indices. Here, we present a large comprehensive catalog of 70 GRBs with multiwavelength optical transient data on which we perform a systematic study to find the temporal evolution of color indices. We categorize them into two samples based on how well the color indices are evaluated. The Golden sample includes 25 bursts mostly observed by GROND, and the Silver sample includes 45 bursts observed by other telescopes. For the Golden sample, we find that 96% of the color indices do not vary over time. However, the color indices do vary during short periods in most bursts. The observed variations are consistent with effects of (i) the cooling frequency crossing the studied energy bands in a wind medium (43%) and in a constant-density medium (30%), (ii) early dust extinction (12%), (iii) transition from reverse-shock to forward-shock emission (5%), or (iv) an emergent SN emission (10%). We also study the evolutionary properties of the mean color indices for different emission episodes. We find that 86% of the color indices in the 70 bursts show constancy between consecutive ones. The color index variations occur mainly during the late GRB–SN bump, the flare, and early reverse-shock emission components. We further perform a statistical analysis of various observational properties and model parameters (spectral index {β }o{CI}, electron spectral indices p CI, etc.) using color indices. Overall, we conclude that ∼90% of colors are constant in time and can be accounted for by the simplest external forward-shock model, while the varying color indices call for more detailed modeling.

  2. iPTF15eqv: Multiwavelength Exposé of a Peculiar Calcium-rich Transient

    Science.gov (United States)

    Milisavljevic, Dan; Patnaude, Daniel J.; Raymond, John C.; Drout, Maria R.; Margutti, Raffaella; Kamble, Atish; Chornock, Ryan; Guillochon, James; Sanders, Nathan E.; Parrent, Jerod T.; Lovisari, Lorenzo; Chilingarian, Igor V.; Challis, Peter; Kirshner, Robert P.; Penny, Matthew T.; Itagaki, Koichi; Eldridge, J. J.; Moriya, Takashi J.

    2017-09-01

    The progenitor systems of the class of “Ca-rich transients” is a key open issue in time domain astrophysics. These intriguing objects exhibit unusually strong calcium line emissions months after explosion, fall within an intermediate luminosity range, are often found at large projected distances from their host galaxies, and may play a vital role in enriching galaxies and the intergalactic medium. Here we present multiwavelength observations of iPTF15eqv in NGC 3430, which exhibits a unique combination of properties that bridge those observed in Ca-rich transients and SNe Ib/c. iPTF15eqv has among the highest [Ca II]/[O I] emission line ratios observed to date, yet is more luminous and decays more slowly than other Ca-rich transients. Optical and near-infrared photometry and spectroscopy reveal signatures consistent with the supernova explosion of a ≲ 10 {M}⊙ star that was stripped of its H-rich envelope via binary interaction. Distinct chemical abundances and ejecta kinematics suggest that the core collapse occurred through electron-capture processes. Deep limits on possible radio emission made with the Jansky Very Large Array imply a clean environment (n ≲ 0.1 cm-3) within a radius of ˜ {10}17 cm. Chandra X-ray Observatory observations rule out alternative scenarios involving the tidal disruption of a white dwarf (WD) by a black hole, for masses >100 M ⊙. Our results challenge the notion that spectroscopically classified Ca-rich transients only originate from WD progenitor systems, complicate the view that they are all associated with large ejection velocities, and indicate that their chemical abundances may vary widely between events.

  3. Status of MUSIC, the MUltiwavelength Sub/millimeter Inductance Camera

    Science.gov (United States)

    Golwala, Sunil R.; Bockstiegel, Clint; Brugger, Spencer; Czakon, Nicole G.; Day, Peter K.; Downes, Thomas P.; Duan, Ran; Gao, Jiansong; Gill, Amandeep K.; Glenn, Jason; Hollister, Matthew I.; LeDuc, Henry G.; Maloney, Philip R.; Mazin, Benjamin A.; McHugh, Sean G.; Miller, David; Noroozian, Omid; Nguyen, Hien T.; Sayers, Jack; Schlaerth, James A.; Siegel, Seth; Vayonakis, Anastasios K.; Wilson, Philip R.; Zmuidzinas, Jonas

    2012-09-01

    We present the status of MUSIC, the MUltiwavelength Sub/millimeter Inductance Camera, a new instrument for the Caltech Submillimeter Observatory. MUSIC is designed to have a 14', diffraction-limited field-of-view instrumented with 2304 detectors in 576 spatial pixels and four spectral bands at 0.87, 1.04, 1.33, and 1.98 mm. MUSIC will be used to study dusty star-forming galaxies, galaxy clusters via the Sunyaev-Zeldovich effect, and star formation in our own and nearby galaxies. MUSIC uses broadband superconducting phased-array slot-dipole antennas to form beams, lumpedelement on-chip bandpass filters to define spectral bands, and microwave kinetic inductance detectors to sense incoming light. The focal plane is fabricated in 8 tiles consisting of 72 spatial pixels each. It is coupled to the telescope via an ambient-temperature ellipsoidal mirror and a cold reimaging lens. A cold Lyot stop sits at the image of the primary mirror formed by the ellipsoidal mirror. Dielectric and metal-mesh filters are used to block thermal infrared and out-ofband radiation. The instrument uses a pulse tube cooler and 3He/ 3He/4He closed-cycle cooler to cool the focal plane to below 250 mK. A multilayer shield attenuates Earth's magnetic field. Each focal plane tile is read out by a single pair of coaxes and a HEMT amplifier. The readout system consists of 16 copies of custom-designed ADC/DAC and IF boards coupled to the CASPER ROACH platform. We focus on recent updates on the instrument design and results from the commissioning of the full camera in 2012.

  4. Implementation of Rotational Raman Channel in Multiwavelength Aerosol Lidar to Improve Measurements of Particle Extinction and Backscattering at 532 NM

    Directory of Open Access Journals (Sweden)

    Veselovskii Igor

    2016-01-01

    Full Text Available We describe a practical implementation of rotational Raman (RR measurements in an existing Mie-Raman lidar to obtain measurements of aerosol extinction and backscattering at 532 nm. A 2.3 nm width interference filter was used to select a spectral range characterized by low temperature sensitivity within the anti-Stokes branch of the RR spectrum. Simulations demonstrate that the temperature dependence of the scattering cross section does not exceed 1.0% in the 230-300K range making accurate correction for this dependence quite easy. With this upgrade, the NASA/GSFC multiwavelength Raman lidar has demonstrated useful α532 measurements and was used for regular observations. Examples of lidar measurements and inversion of optical data to the particle microphysics will be given in presentation.

  5. Multiwavelength mode-locked cylindrical vector beam fiber laser based on mode selective coupler

    Science.gov (United States)

    Huang, Ping; Cai, Yu; Wang, Jie; Wan, Hongdan; Zhang, Zuxing; Zhang, Lin

    2017-10-01

    We propose and demonstrate a multiwavelength mode-locked fiber laser with cylindrical vector beam generation for the first time, to the best of our knowledge. The mode-locking mechanism is based on a nonlinear polarization rotation effect in fiber, and the multiwavelength operation is contributed to by an in-line birefringence fiber filter with periodic multiple passbands, formed by incorporating a section of polarization maintaining fiber into the laser cavity with a fiber polarizer. Furthermore, by using a home-made mode selective coupler, which acts as both a mode converter from fundamental mode to higher-order mode and an output coupler, multiwavelength mode-locked cylindrical vector beams have been obtained. This may have potential applications in mode-division multiplexing optical fiber communication and material processing.

  6. Multiwavelength digital holography with wavelength-multiplexed holograms and arbitrary symmetric phase shifts.

    Science.gov (United States)

    Tahara, Tatsuki; Otani, Reo; Omae, Kaito; Gotohda, Takuya; Arai, Yasuhiko; Takaki, Yasuhiro

    2017-05-15

    We propose multiwavelength in-line digital holography with wavelength-multiplexed phase-shifted holograms and arbitrary symmetric phase shifts. We use phase-shifting interferometry selectively extracting wavelength information to reconstruct multiwavelength object waves separately from wavelength-multiplexed monochromatic images. The proposed technique obtains systems of equations for real and imaginary parts of multiwavelength object waves from the holograms by introducing arbitrary symmetric phase shifts. Then, the technique derives each complex amplitude distribution of each object wave selectively and analytically by solving the two systems of equations. We formulate the algorithm in the case of an arbitrary number of wavelengths and confirm its validity numerically and experimentally in the cases where the number of wavelengths is two and three.

  7. On the Frequency and Voltage-Dependent Profiles of the Surface States and Series Resistance of Au/ZnO/n-Si Structures in a Wide Range of Frequency and Voltage

    Science.gov (United States)

    Nikravan, Afsoun; Badali, Yosef; Altındal, Şemsettin; Uslu, İbrahim; Orak, İkram

    2017-10-01

    In order to interpret the electrical characteristics of fabricated Au/ZnO/n-Si structures as a function of frequency and voltage well, their capacitance-voltage ( C- V) and conductance-voltage ( G/ ω- V) measurements were carried out in a wide range of frequencies (0.7 kHz-2 MHz) and voltages (± 6 V) by 50 mV steps at room temperature. Both the C- V and G/ ω- V plots have reverse, depletion, and accumulation regions such as a metal-insulator/oxide semiconductor (MIS or MOS) structures. The values of doped-donor atoms ( N D), Fermi energy level ( E F), barrier height (ΦB), and series resistance ( R s) of the structure were obtained as a function of frequency and voltage. While the value of N D decreases with increasing frequency almost as exponentially, the value of depletion width ( W D) increases. The values of C and G/ ω increase with decreasing frequency because the surface states ( N ss) are able to follow the alternating current (AC) signal, resulting in excess capacitance ( C ex) and conductance ( G ex/ ω), which depends on their relaxation time and the frequency of the AC signal. The voltage-dependent profiles of N ss were obtained from both the high-low frequency capacitance and Hill-Colleman methods. The other important parameter R s of the structure was also obtained from the Nicollian and Brews methods as a function of voltage.

  8. Long-term Optical Polarization Variability and Multiwavelength Analysis of Blazar Mrk 421

    Science.gov (United States)

    Fraija, N.; Benítez, E.; Hiriart, D.; Sorcia, M.; López, J. M.; Mújica, R.; Cabrera, J. I.; de Diego, J. A.; Rojas-Luis, M.; Salazar-Vázquez, F. A.; Galván-Gámez, A.

    2017-09-01

    The results of 8 yr R-band photopolarimetric data of blazar Mrk 421 collected from 2008 February to 2016 May are presented, along with extensive multiwavelength observations covering radio to TeV γ-rays around the flares observed in 2008 May, 2010 March, and 2013 April. The most important results are found in 2013, when the source displayed in the R band a very high brightness state of 11.29 ± 0.03 mag (93.60 ± 1.53 mJy) on April 10 and a polarization degree of 11.00% ± 0.44% on May 13. The analysis of the optical data shows that the polarization variability is due to the superposition of two polarized components that might be produced in two distinct emitting regions. An intranight photopolarimetric variability study carried out over seven nights after the 2013 April maximum found flux and polarization variations on the nights of April 14, 15, 16, and 19. In addition, the flux shows a minimum variability timescale of Δt = 2.34 ± 0.12 hr, and the polarization degree presents variations of ˜1%-2% on a timescale of Δ t ˜ minutes. Also, a detailed analysis of the intranight data shows a coherence length of the large-scale magnetic field of {l}B≃ 0.3 pc, which is the same order of magnitude as the distance traveled by the relativistic shocks. This result suggests that there is a connection between the intranight polarimetric variations and spatial changes of the magnetic field. Analysis of the complete R-band data along with the historical optical light curve found for this object shows that Mrk 421 varies with a period of 16.26 ± 1.78 yr.

  9. Multiwavelength behaviour of the blazar OJ 248 from radio to γ-rays

    Science.gov (United States)

    Carnerero, M. I.; Raiteri, C. M.; Villata, M.; Acosta-Pulido, J. A.; D'Ammando, F.; Smith, P. S.; Larionov, V. M.; Agudo, I.; Arévalo, M. J.; Arkharov, A. A.; Bach, U.; Bachev, R.; Benítez, E.; Blinov, D. A.; Bozhilov, V.; Buemi, C. S.; Bueno Bueno, A.; Carosati, D.; Casadio, C.; Chen, W. P.; Damljanovic, G.; di Paola, A.; Efimova, N. V.; Ehgamberdiev, Sh. A.; Giroletti, M.; Gómez, J. L.; González-Morales, P. A.; Grinon-Marin, A. B.; Grishina, T. S.; Gurwell, M. A.; Hiriart, D.; Hsiao, H. Y.; Ibryamov, S.; Jorstad, S. G.; Joshi, M.; Kopatskaya, E. N.; Kurtanidze, O. M.; Kurtanidze, S. O.; Lähteenmäki, A.; Larionova, E. G.; Larionova, L. V.; Lázaro, C.; Leto, P.; Lin, C. S.; Lin, H. C.; Manilla-Robles, A. I.; Marscher, A. P.; McHardy, I. M.; Metodieva, Y.; Mirzaqulov, D. O.; Mokrushina, A. A.; Molina, S. N.; Morozova, D. A.; Nikolashvili, M. G.; Orienti, M.; Ovcharov, E.; Panwar, N.; Pastor Yabar, A.; Puerto Giménez, I.; Ramakrishnan, V.; Richter, G. M.; Rossini, M.; Sigua, L. A.; Strigachev, A.; Taylor, B.; Tornikoski, M.; Trigilio, C.; Troitskaya, Yu. V.; Troitsky, I. S.; Umana, G.; Valcheva, A.; Velasco, S.; Vince, O.; Wehrle, A. E.; Wiesemeyer, H.

    2015-07-01

    We present an analysis of the multiwavelength behaviour of the blazar OJ 248 at z = 0.939 in the period 2006-2013. We use low-energy data (optical, near-infrared, and radio) obtained by 21 observatories participating in the Gamma-Ray Large Area Space Telescope (GLAST)-AGILE Support Program of the Whole Earth Blazar Telescope, as well as data from the Swift (optical-UV and X-rays) and Fermi (γ-rays) satellites, to study flux and spectral variability and correlations among emissions in different bands. We take into account the effect of absorption by the Damped Lyman α intervening system at z = 0.525. Two major outbursts were observed in 2006-2007 and in 2012-2013 at optical and near-IR wavelengths, while in the high-frequency radio light curves prominent radio outbursts are visible peaking at the end of 2010 and beginning of 2013, revealing a complex radio-optical correlation. Cross-correlation analysis suggests a delay of the optical variations after the γ-ray ones of about a month, which is a peculiar behaviour in blazars. We also analyse optical polarimetric and spectroscopic data. The average polarization percentage P is less than 3 per cent, but it reaches ˜19 per cent during the early stage of the 2012-2013 outburst. A vague correlation of P with brightness is observed. There is no preferred electric vector polarization angle and during the outburst the linear polarization vector shows wide rotations in both directions, suggesting a complex behaviour/structure of the jet and possible turbulence. The analysis of 140 optical spectra acquired at the Steward Observatory reveals a strong Mg II broad emission line with an essentially stable flux of 6.2 × 10- 15 erg cm- 2 s- 1 and a full width at half-maximum of 2053 km s- 1.

  10. Synthetic 3D modeling of active regions and simulation of their multi-wavelength emission

    Science.gov (United States)

    Nita, Gelu M.; Fleishman, Gregory; Kuznetsov, Alexey A.; Loukitcheva, Maria A.; Viall, Nicholeen M.; Klimchuk, James A.; Gary, Dale E.

    2015-04-01

    To facilitate the study of solar active regions, we have created a synthetic modeling framework that combines 3D magnetic structures obtained from magnetic extrapolations with simplified 1D thermal models of the chromosphere, transition region, and corona. To handle, visualize, and use such synthetic data cubes to compute multi-wavelength emission maps and compare them with observations, we have undertaken a major enhancement of our simulation tools, GX_Simulator (ftp://sohoftp.nascom.nasa.gov/solarsoft/packages/gx_simulator/), developed earlier for modeling emission from flaring loops. The greatly enhanced, object-based architecture, which now runs on Windows, Mac, and UNIX platform, offers important new capabilities that include the ability to either import 3D density and temperature distribution models, or to assign to each individual voxel numerically defined coronal or chromospheric temperature and densities, or coronal Differential Emission Measure distributions. Due to these new capabilities, the GX_Simulator can now apply parametric heating models involving average properties of the magnetic field lines crossing a given voxel volume, as well as compute and investigate the spatial and spectral properties of radio (to be compared with VLA or EOVSA data), (sub-)millimeter (ALMA), EUV (AIA/SDO), and X-ray (RHESSI) emission calculated from the model. The application integrates shared-object libraries containing fast free-free, gyrosynchrotron, and gyroresonance emission codes developed in FORTRAN and C++, and soft and hard X-ray and EUV codes developed in IDL. We use this tool to model and analyze an active region and compare the synthetic emission maps obtained in different wavelengths with observations.This work was partially supported by NSF grants AGS-1250374, AGS-1262772, NASA grant NNX14AC87G, the Marie Curie International Research Staff Exchange Scheme "Radiosun" (PEOPLE-2011-IRSES-295272), RFBR grants 14-02-91157, 15-02-01089, 15-02-03717, 15

  11. VizieR Online Data Catalog: S2CLS: multiwavelength counterparts to SMGs (Chen+, 2016)

    Science.gov (United States)

    Chen, C.-C.; Smail, I.; Ivison, R. J.; Arumugam, V.; Almaini, O.; Conselice, C. J.; Geach, J. E.; Hartley, W. G.; Ma, C.-J.; Mortlock, A.; Simpson, C.; Simpson, J. M.; Swinbank, A. M.; Aretxaga, I.; Blain, A.; Chapman, S. C.; Dunlop, J. S.; Farrah, D.; Halpern, M.; Michalowski, M. J.; van der Werf, P.; Wilkinson, A.; Zavala, J. A.

    2016-05-01

    The SCUBA-2 data at 850um in the UDS field were taken as part of the SCUBA-2 Cosmology Legacy Survey (S2CLS). The full data reduction steps are described fully in J. E. Geach et al. (2016, in preparation). In total we detect 1088 submillimeter sources at >=3.5σ within the region where rms noise is =4.0σ, for which we expect a false detection rate of ~1% based on simulations and source extractions on negative signals. We also define a supplementary sample of 372 submillimeter sources that are detected at 3.5-4.0σ and have a false detection rate of ~10%. In this paper, we provide counterpart candidates for both main and supplementary samples; however, the scientific analyses were performed on the main sample. We have carried out ALMA follow-up observations at 870um on 30 of the brighter SCUBA-2 sources in a Cycle 1 project 2012.1.00090.S (Simpson et al. 2015ApJ...807..128S, 2015ApJ...799...81S). The K-band-based multiwavelength photometry adopted in this paper is based on the UDS data release 8 (DR8) of the UKIRT Infrared Deep Sky Survey (UKIDSS; Lawrence et al. 2007, see II/319). The VLA radio observations at 1.4GHz (20cm) were carried out by the project UDS20 (V. Arumugam et al. 2016, in preparation), which comprises a mosaic of 14 pointings covering a total area of ~1.3deg2 centered on the UDS. The ~1 square degree UDS field contains a rich set of ancillary data (see section 2 for further details). (2 data files).

  12. Beneficial effects of reading aloud and solving simple arithmetic calculations (learning therapy) on a wide range of cognitive functions in the healthy elderly: study protocol for a randomized controlled trial

    Science.gov (United States)

    2012-01-01

    Background Almost all cognitive functions decline with age. Results of previous studies have shown that cognitive training related to everyday life (reading aloud and solving simple arithmetic calculations), namely learning therapy, can improve two cognitive function (executive functions and processing speed) in elderly people. However, it remains unclear whether learning therapy engenders improvement of various cognitive functions or not. We investigate the impact of learning therapy on various cognitive functions (executive functions, episodic memory, short-term memory, working memory, attention, reading ability, and processing speed) in healthy older adults. Methods We use a single-blinded intervention with two parallel groups (a learning therapy group and a waiting list control group). Testers are blind to the study hypothesis and the group membership of participants. Through an advertisement in local newspaper, 64 healthy older adults are recruited. They will be assigned randomly to a learning therapy group or a waiting list control group. In the learning therapy group, participants are required to perform two cognitive tasks for 6 months: reading Japanese aloud and solving simple calculations. The waiting list group does not participate in the intervention. The primary outcome measure is the Stroop test score: a measure of executive function. Secondary outcome measures are assessments including the following: verbal fluency task, logical memory, first and second names, digit span forward, digit span backward, Japanese reading test, digit cancellation task, digit symbol coding, and symbol search. We assess these outcome measures before and after the intervention. Discussion This report is the first study which investigates the beneficial effects of learning therapy on a wide range of cognitive functions of elderly people. Our study provides sufficient evidence of learning therapy effectiveness. Most cognitive functions, which are correlated strongly with daily

  13. Beneficial effects of reading aloud and solving simple arithmetic calculations (learning therapy) on a wide range of cognitive functions in the healthy elderly: study protocol for a randomized controlled trial.

    Science.gov (United States)

    Nouchi, Rui; Taki, Yasuyuki; Takeuchi, Hikaru; Hashizume, Hiroshi; Nozawa, Takayuki; Sekiguchi, Atsushi; Nouchi, Haruka; Kawashima, Ryuta

    2012-04-06

    Almost all cognitive functions decline with age. Results of previous studies have shown that cognitive training related to everyday life (reading aloud and solving simple arithmetic calculations), namely learning therapy, can improve two cognitive function (executive functions and processing speed) in elderly people. However, it remains unclear whether learning therapy engenders improvement of various cognitive functions or not. We investigate the impact of learning therapy on various cognitive functions (executive functions, episodic memory, short-term memory, working memory, attention, reading ability, and processing speed) in healthy older adults. We use a single-blinded intervention with two parallel groups (a learning therapy group and a waiting list control group). Testers are blind to the study hypothesis and the group membership of participants. Through an advertisement in local newspaper, 64 healthy older adults are recruited. They will be assigned randomly to a learning therapy group or a waiting list control group. In the learning therapy group, participants are required to perform two cognitive tasks for 6 months: reading Japanese aloud and solving simple calculations. The waiting list group does not participate in the intervention. The primary outcome measure is the Stroop test score: a measure of executive function. Secondary outcome measures are assessments including the following: verbal fluency task, logical memory, first and second names, digit span forward, digit span backward, Japanese reading test, digit cancellation task, digit symbol coding, and symbol search. We assess these outcome measures before and after the intervention. This report is the first study which investigates the beneficial effects of learning therapy on a wide range of cognitive functions of elderly people. Our study provides sufficient evidence of learning therapy effectiveness. Most cognitive functions, which are correlated strongly with daily life activities, decrease

  14. Beneficial effects of reading aloud and solving simple arithmetic calculations (learning therapy on a wide range of cognitive functions in the healthy elderly: study protocol for a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Nouchi Rui

    2012-04-01

    Full Text Available Abstract Background Almost all cognitive functions decline with age. Results of previous studies have shown that cognitive training related to everyday life (reading aloud and solving simple arithmetic calculations, namely learning therapy, can improve two cognitive function (executive functions and processing speed in elderly people. However, it remains unclear whether learning therapy engenders improvement of various cognitive functions or not. We investigate the impact of learning therapy on various cognitive functions (executive functions, episodic memory, short-term memory, working memory, attention, reading ability, and processing speed in healthy older adults. Methods We use a single-blinded intervention with two parallel groups (a learning therapy group and a waiting list control group. Testers are blind to the study hypothesis and the group membership of participants. Through an advertisement in local newspaper, 64 healthy older adults are recruited. They will be assigned randomly to a learning therapy group or a waiting list control group. In the learning therapy group, participants are required to perform two cognitive tasks for 6 months: reading Japanese aloud and solving simple calculations. The waiting list group does not participate in the intervention. The primary outcome measure is the Stroop test score: a measure of executive function. Secondary outcome measures are assessments including the following: verbal fluency task, logical memory, first and second names, digit span forward, digit span backward, Japanese reading test, digit cancellation task, digit symbol coding, and symbol search. We assess these outcome measures before and after the intervention. Discussion This report is the first study which investigates the beneficial effects of learning therapy on a wide range of cognitive functions of elderly people. Our study provides sufficient evidence of learning therapy effectiveness. Most cognitive functions, which are

  15. Continuous Bulk FeCuC Aerogel with Ultradispersed Metal Nanoparticles: An Efficient 3D Heterogeneous Electro-Fenton Cathode over a Wide Range of pH 3-9.

    Science.gov (United States)

    Zhao, Hongying; Qian, Lin; Guan, Xiaohong; Wu, Deli; Zhao, Guohua

    2016-05-17

    Novel iron-copper-carbon (FeCuC) aerogel was fabricated through a one-step process from metal-resin precursors and then activated with CO2 and N2 in environmentally friendly way. The activated FeCuC aerogel was applied in a heterogeneous electro-Fenton (EF) process and exhibited higher mineralization efficiency than homogeneous EF technology. High total organic carbon (TOC) removal of organic pollutants with activated FeCuC aerogel was achieved at a wide range of pH values (3-9). The chemical oxygen demand (COD) of real dyeing wastewater was below China's discharge standard after 30 min of treatment, and the specific energy consumption was low (9.2 kW·h·kg(-1)COD(-1)), corresponding to a power consumption of only ∼0.34 kW·h per ton of wastewater. The enhanced mineralization efficiency of FeCuC aerogel was mostly attributable to ultradispersed metallic Fe-Cu nanoparticles embedded in 3D carbon matrix and the CO2-N2 treatment. The CO2 activation enhanced the accessibility of the aerogel's pores, and the secondary N2 activation enlarged the porosity and regenerated the ultradispersed zerovalent iron (Fe(0)) with reductive carbon. Cu(0) acted as a reduction promoter for interfacial electron transfer. Moreover, activated FeCuC aerogel presented low iron leaching (<0.1 ppm) in acidic solution and can be molded into different sizes with high flexibility. Thus, this material could be used as a low-cost cathode and efficient heterogeneous EF technology for actual wastewater treatment.

  16. Multiwavelength and Polarimetric Analysis of the Flat Spectrum Radio Quasars 3C 273 and 3C 279

    Science.gov (United States)

    Fernandes, Sunil; Patiño-Álvarez, Victor; Chavushyan, Vahram; Schlegel, Eric M.; Lopez-Rodriguez, Enrique; León-Tavares, Jonathan; Carrasco, Luis; Valdés, José; Carramiñana, Alberto

    2017-01-01

    This poster presents results of multiwavelength analyses of 3C 273 and 3C 279. The main goals were to identify the gamma-ray emission region and dominant high-energy emission processes. Our methodology consisted of analyzing light curves from radio to gamma-rays over 6 - 8 years and polarimetric, spectral and line emission behavior.In 3C 279, we found that the emission from millimeter to ultraviolet was simultaneous and therefore co-spatial. We identified two active states where different high-energy emission processes were dominant. We found multiwavelength flaring events consistent with component ejections and shocks. We proposed that the gamma-ray emission region changed over time based on observations of both simultaneous and delayed gamma-rays emission with respect to low-energy emission during different time-frames.In 3C 273, we identified a non-thermal flare related to a component ejection and a thermal flare related to accretion. From reverberation mapping we found that the broad line region dynamical behavior over time possibly affects the derived supermassive black hole mass.In both objects we found that the gamma-ray spectral index was variable, and a trend of harder spectral index with higher gamma-ray luminosity. From the identification of different dominant high-energy emission processes, we concluded that the dominant high-energy emission mechanism changes with time. Overall, we concluded that similar results from both objects points to behavior that is potentially common to flat spectrum radio quasars. Increasing the sample size of objects analyzed with similar methodologies will provide more results to confirm or refine our conclusions.

  17. Early BHs: simulations and observations

    Science.gov (United States)

    Cappelluti, Nico; di-Matteo, Tiziana; Schawinski, Kevin; Fragos, Tassos

    We report recent investigations in the field of Early Black Holes. We summarize recent theoretical and observational efforts to understand how Black Holes formed and eventually evolved into Super Massive Black Holes at high-z. This paper makes use of state of the art computer simulations and multiwavelength surveys. Although non conclusive, we present results and hypothesis that pose exciting challenges to modern astrophysics and to future facilities.

  18. Pulse-Shape Control in an All Fiber Multi-Wavelength Doppler Lidar

    Directory of Open Access Journals (Sweden)

    Töws Albert

    2016-01-01

    Full Text Available Pulse distortion during amplification in fiber amplifiers due to gain saturation and cross talk in a multi-wavelength Doppler lidar are discussed. We present a feedback control technique which is capable of adjusting any predefined pulse shape and show some examples of feedback controlled pulse shapes.

  19. Temperature Sensor Using a Multiwavelength Erbium-Doped Fiber Ring Laser

    Directory of Open Access Journals (Sweden)

    Silvia Diaz

    2017-01-01

    Full Text Available A novel temperature sensor is presented based on a multiwavelength erbium-doped fiber ring laser. The laser is comprised of fiber Bragg grating reflectors as the oscillation wavelength selecting filters. The performance of the temperature sensor in terms of both wavelength and laser output power was investigated, as well as the application of this system for remote temperature measurements.

  20. Multi-Wavelength Variability Properties of Fermi Blazar S5 0716+ 714

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... The multi-wavelength variability behaviours can be naturally explained by the classic leptonic model. We model the average SED of S5 0716 + 714 by leptonic model. The SSC+ERC model using the external seed photons from hot dust or Broad Line Region (BLR) emission is probably favourable avoiding ...

  1. THE zCOSMOS-SINFONI PROJECT. I. SAMPLE SELECTION AND NATURAL-SEEING OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Mancini, C.; Renzini, A. [INAF-OAPD, Osservatorio Astronomico di Padova, Vicolo Osservatorio 5, I-35122 Padova (Italy); Foerster Schreiber, N. M.; Hicks, E. K. S.; Genzel, R.; Tacconi, L.; Davies, R. [Max-Planck-Institut fuer Extraterrestrische Physik, Giessenbachstrasse, D-85748 Garching (Germany); Cresci, G. [Osservatorio Astrofisico di Arcetri (OAF), INAF-Firenze, Largo E. Fermi 5, I-50125 Firenze (Italy); Peng, Y.; Lilly, S.; Carollo, M.; Oesch, P. [Institute of Astronomy, Department of Physics, Eidgenossische Technische Hochschule, ETH Zurich CH-8093 (Switzerland); Vergani, D.; Pozzetti, L.; Zamorani, G. [INAF-Bologna, Via Ranzani, I-40127 Bologna (Italy); Daddi, E. [CEA-Saclay, DSM/DAPNIA/Service d' Astrophysique, F-91191 Gif-Sur Yvette Cedex (France); Maraston, C. [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Burnaby Road, PO1 3HE Portsmouth (United Kingdom); McCracken, H. J. [IAP, 98bis bd Arago, F-75014 Paris (France); Bouche, N. [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Shapiro, K. [Aerospace Research Laboratories, Northrop Grumman Aerospace Systems, Redondo Beach, CA 90278 (United States); and others

    2011-12-10

    The zCOSMOS-SINFONI project is aimed at studying the physical and kinematical properties of a sample of massive z {approx} 1.4-2.5 star-forming galaxies, through SINFONI near-infrared integral field spectroscopy (IFS), combined with the multiwavelength information from the zCOSMOS (COSMOS) survey. The project is based on one hour of natural-seeing observations per target, and adaptive optics (AO) follow-up for a major part of the sample, which includes 30 galaxies selected from the zCOSMOS/VIMOS spectroscopic survey. This first paper presents the sample selection, and the global physical characterization of the target galaxies from multicolor photometry, i.e., star formation rate (SFR), stellar mass, age, etc. The H{alpha} integrated properties, such as, flux, velocity dispersion, and size, are derived from the natural-seeing observations, while the follow-up AO observations will be presented in the next paper of this series. Our sample appears to be well representative of star-forming galaxies at z {approx} 2, covering a wide range in mass and SFR. The H{alpha} integrated properties of the 25 H{alpha} detected galaxies are similar to those of other IFS samples at the same redshifts. Good agreement is found among the SFRs derived from H{alpha} luminosity and other diagnostic methods, provided the extinction affecting the H{alpha} luminosity is about twice that affecting the continuum. A preliminary kinematic analysis, based on the maximum observed velocity difference across the source and on the integrated velocity dispersion, indicates that the sample splits nearly 50-50 into rotation-dominated and velocity-dispersion-dominated galaxies, in good agreement with previous surveys.

  2. Feasibility Study of Multi-Wavelength Differential Absorption LIDAR for CO2 Monitoring

    Directory of Open Access Journals (Sweden)

    Chengzhi Xiang

    2016-06-01

    Full Text Available To obtain a better understanding of carbon cycle and accurate climate prediction models, highly accurate and temporal resolution observation of atmospheric CO2 is necessary. Differential absorption LIDAR (DIAL remote sensing is a promising technology to detect atmospheric CO2. However, the traditional DIAL system is the dual-wavelength DIAL (DW-DIAL, which has strict requirements for wavelength accuracy and stability. Moreover, for on-line and off-line wavelengths, the system’s optical efficiency and the change of atmospheric parameters are assumed to be the same in the DW-DIAL system. This assumption inevitably produces measurement errors, especially under rapid aerosol changes. In this study, a multi-wavelength DIAL (MW-DIAL is proposed to map atmospheric CO2 concentration. The MW-DIAL conducts inversion with one on-line and multiple off-line wavelengths. Multiple concentrations of CO2 are then obtained through difference processing between the single on-line and each of the off-line wavelengths. In addition, the least square method is adopted to optimize inversion results. Consequently, the inversion concentration of CO2 in the MW-DIAL system is found to be the weighted average of the multiple concentrations. Simulation analysis and laboratory experiments were conducted to evaluate the inversion precision of MW-DIAL. For comparison, traditional DW-DIAL simulations were also conducted. Simulation analysis demonstrated that, given the drifting wavelengths of the laser, the detection accuracy of CO2 when using MW-DIAL is higher than that when using DW-DIAL, especially when the drift is large. A laboratory experiment was also performed to verify the simulation analysis.

  3. A MULTI-WAVELENGTH STUDY OF STAR FORMATION ACTIVITY IN THE S235 COMPLEX

    Energy Technology Data Exchange (ETDEWEB)

    Dewangan, L. K.; Luna, A.; Mayya, Y. D. [Instituto Nacional de Astrofísica, Óptica y Electrónica, Luis Enrique Erro # 1, Tonantzintla, Puebla, C.P. 72840, México (Mexico); Ojha, D. K.; Ninan, J. P.; Mallick, K. K. [Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005 (India); Anandarao, B. G., E-mail: lokeshd@prl.res.in [Physical Research Laboratory, Navrangpura, Ahmedabad—380 009 (India)

    2016-03-01

    We have carried out an extensive multi-wavelength study to investigate the star formation process in the S235 complex. The S235 complex has a spherelike shell appearance at wavelengths longer than 2 μm and harbors an O9.5V type star approximately at its center. A near-infrared extinction map of the complex traces eight subregions (having A{sub V} > 8 mag), and five of them appear to be distributed in an almost regularly spaced manner along the spherelike shell surrounding the ionized emission. This picture is also supported by the integrated {sup 12}CO and {sup 13}CO intensity maps and by Bolocam 1.1 mm continuum emission. The position–velocity analysis of CO reveals an almost semi-ringlike structure, suggesting an expanding H ii region. We find that the Bolocam clump masses increase as we move away from the location of the ionizing star. This correlation is seen only for those clumps that are distributed near the edges of the shell. Photometric analysis reveals 435 young stellar objects (YSOs), 59% of which are found in clusters. Six subregions (including five located near the edges of the shell) are very well correlated with the dust clumps, CO gas, and YSOs. The average values of Mach numbers derived using NH{sub 3} data for three (East 1, East 2, and Central E) out of these six subregions are 2.9, 2.3, and 2.9, indicating these subregions are supersonic. The molecular outflows are detected in these three subregions, further confirming the ongoing star formation activity. Together, all these results are interpreted as observational evidence of positive feedback of a massive star.

  4. Multi-wavelength study of triggered star formation around the mid-infrared bubble N14

    Science.gov (United States)

    Dewangan, L. K.; Ojha, D. K.

    2013-02-01

    We present multi-wavelength analysis around the mid-infrared (MIR) bubble N14 to probe the signature of triggered star formation as well as the formation of new massive star(s) and/or cluster(s) at the borders of the bubble by the expansion of the H II region. Spitzer Infrared Array Camera ratio maps reveal that the bubble is traced by the polycyclic aromatic hydrocarbon emission following an almost circular morphology except in the south-west direction towards the low molecular density environment. The observational signatures of the collected molecular and cold dust material have been found around the bubble. We have detected 418 young stellar objects (YSOs) in the selected region around the bubble N14. Interestingly, the detected YSO clusters are associated with the collected molecular and cold dust material at the borders of the bubble. One of the clusters is found with deeply embedded intermediate mass and massive Class I YSOs associated with one of the dense dust clumps in the east of the bubble N14. We do not find good agreement between the dynamical age of the H II region and the fragmentation time of the accumulated molecular materials to explain the possible `collect-and-collapse' process around the bubble N14. Therefore, we suggest the possibility of triggered star formation by compression of the pre-existing dense clumps by the shock wave and/or small-scale Jeans gravitational instabilities in the collected materials. We have also investigated 5 young massive embedded protostars (8-10 M⊙) and 15 intermediate mass (3-7 M⊙) Class I YSOs which are associated with the dust and molecular fragmented clumps at the borders of the bubble. We conclude that the expansion of the H II region is also leading to the formation of these intermediate and massive Class I YSOs around the bubble N14.

  5. Star formation and AGN activity in a sample of local luminous infrared galaxies through multiwavelength characterization

    Science.gov (United States)

    Herrero-Illana, Rubén; Pérez-Torres, Miguel Á.; Randriamanakoto, Zara; Alberdi, Antxon; Efstathiou, Andreas; Väisänen, Petri; Kankare, Erkki; Kool, Erik; Mattila, Seppo; Ramphul, Rajin; Ryder, Stuart

    2017-10-01

    Nuclear starbursts and active galactic nucleus (AGN) activity are the main heating processes in luminous infrared galaxies (LIRGs) and their relationship is fundamental to understand galaxy evolution. In this paper, we study the star formation and AGN activity of a sample of 11 local LIRGs imaged with subarcsecond angular resolution at radio (8.4 GHz) and near-infrared (2.2 μm) wavelengths. This allows us to characterize the central kpc of these galaxies with a spatial resolution of ≃100 pc. In general, we find a good spatial correlation between the radio and the near-IR emission, although radio emission tends to be more concentrated in the nuclear regions. Additionally, we use an Markov Chain Monte Carlo code to model their multiwavelength spectral energy distribution (SED) using template libraries of starburst, AGN and spheroidal/cirrus models, determining the luminosity contribution of each component, and finding that all sources in our sample are starburst-dominated, except for NGC 6926 with an AGN contribution of ≃64 per cent. Our sources show high star formation rates (40-167 M⊙ yr-1), supernova rates (0.4-2.0 SN yr-1) and similar starburst ages (13-29 Myr), except for the young starburst (9 Myr) in NGC 6926. A comparison of our derived star-forming parameters with estimates obtained from different IR and radio tracers shows an overall consistency among the different star formation tracers. AGN tracers based on mid-IR, high-ionization line ratios also show an overall agreement with our SED model fit estimates for the AGN. Finally, we use our wide-band Very Large Array observations to determine pixel-by-pixel radio spectral indices for all galaxies in our sample, finding a typical median value (α ≃ -0.8) for synchrotron-powered LIRGs.

  6. A multiwavelength study of the massive GLIMPSE-C01 cluster with the Hubble Space Telescope and Chandra X-ray Observatory

    Science.gov (United States)

    Hare, Jeremy; Kargaltsev, Oleg; Rangelov, Blagoy

    2018-01-01

    GLIMPSE-C01 is a heavily obscured, intermediate-age cluster that has been suggested to be one of the most massive clusters in the Milky Way. We observed GLIMPSE-C01 with both HST WFC3 IR and UVIS to look for NIR/Optical counterparts to the X-ray sources discovered by the Chandra X-ray Observatory. We present the results of the HST observations, analyze the stellar population of the cluster, and classify X-ray sources using multiwavelength information. We identify several X-ray binary candidates including one likely CV and one likely LMXB. The multi-band HST data also constrain the somewhat controversial distance and age of the cluster. The impact of confusion, affecting the WFC3/IR images of the cluster's core, is also evaluated. The presented observations and their analyses demonstrate the limitations of current instruments and the potential of JWST's superior angular resolution and sensitivety in crowded fields. We also discuss the potential of HST and JWST for multiwavelength X-ray source classification.

  7. Application of the Self Calibrating Emissivity and/or Transmissivity Independent Multiwavelength Pyrometer in an Intense Ambient Radiation Environment

    Science.gov (United States)

    Ng, Daniel

    1996-01-01

    The NASA self calibrating multiwavelength pyrometer is a recent addition to the list of pyrometers used in remote temperature measurement in research and development. The older one-color, two-color, and the disappearing filament pyrometers, as well as the multicolor and early multiwavelength pyrometers, all do not operate successfully in situations in which strong ambient radiation coexists with radiation originating from the measured surface. In such situations radiation departing from the target surface arrives at the pyrometer together with radiation coming from another source either directly or through reflection. Unlike the other pyrometers, the self calibrating multiwavelength pyrometer can still calibrate itself and measure the temperatures in this adverse environment.

  8. The 999th Swift gamma-ray burst: Some like it thermal. A multiwavelength study of GRB 151027A

    Science.gov (United States)

    Nappo, F.; Pescalli, A.; Oganesyan, G.; Ghirlanda, G.; Giroletti, M.; Melandri, A.; Campana, S.; Ghisellini, G.; Salafia, O. S.; D'Avanzo, P.; Bernardini, M. G.; Covino, S.; Carretti, E.; Celotti, A.; D'Elia, V.; Nava, L.; Palazzi, E.; Poppi, S.; Prandoni, I.; Righini, S.; Rossi, A.; Salvaterra, R.; Tagliaferri, G.; Testa, V.; Venturi, T.; Vergani, S. D.

    2017-02-01

    We present a multiwavelength study of GRB 151027A. This is the 999th gamma-ray burst detected by the Swift satellite and it has a densely sampled emission in the X-ray and optical band and has been observed and detected in the radio up to 140 days after the prompt. The multiwavelength light curve from 500 s to 140 days can be modelled through a standard forward shock afterglow, but it requires an additional emission component to reproduce the early X-ray and optical emission. We present optical observations performed with the Telescopio Nazionale Galileo (TNG) and the Large Binocular Telescope (LBT) 19.6, 33.9, and 92.3 days after the trigger which show a bump with respect to a standard afterglow flux decay and are interpreted as possibly due to the underlying supernova and host galaxy (at a level of 0.4 μJy in the optical R band, RAB 25). Radio observations, performed with the Sardinia Radio Telescope (SRT) and Medicina in single-dish mode and with the European Very Long Baseline Interferometer (VLBI) Network and the Very Long Baseline Array (VLBA), between day 4 and 140 suggest that the burst exploded in an environment characterized by a density profile scaling with the distance from the source (wind profile). A remarkable feature of the prompt emission is the presence of a bright flare 100 s after the trigger, lasting 70 s in the soft X-ray band, which was simultaneously detected from the optical band up to the MeV energy range. By combining Swift-BAT/XRT and Fermi-GBM data, the broadband (0.3-1000 keV) time resolved spectral analysis of the flare reveals the coexistence of a non-thermal (power law) and thermal blackbody components. The blackbody component contributes up to 35% of the luminosity in the 0.3-1000 keV band. The γ-ray emission observed in Swift-BAT and Fermi-GBM anticipates and lasts less than the soft X-ray emission as observed by Swift-XRT, arguing against a Comptonization origin. The blackbody component could either be produced by an outflow

  9. Multiwavelength observations of active galactic nuclei : Using current facilities and development of enabling technologies

    NARCIS (Netherlands)

    Janssen, R.M.J.

    2017-01-01

    At the center of every galaxy there is a super-massive black hole of a million or more solar masses. In most galaxies the presence of this black hole can only be detected through its gravitational attraction, which affects the motion of nearby stars. However, in about 10% of the galaxies the

  10. Multiwavelength Observations of an Eruptive Flare: Evidence for Blast Waves and Break-Out

    Science.gov (United States)

    Kumar, Pankaj; Innes, D. E.

    2013-11-01

    Images of an east-limb flare on 3 November 2010 taken in the 131 Å channel of the Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory provide a convincing example of a long current sheet below an erupting plasmoid, as predicted by the standard magnetic reconnection model of eruptive flares. However, the 171 Å and 193 Å channel images hint at an alternative scenario. These images reveal that large-scale waves with velocity greater than 1000 km s-1 propagated alongside and ahead of the erupting plasmoid. Just south of the plasmoid, the waves coincided with type-II radio emission, and to the north, where the waves propagated along plume-like structures, there was increased decimetric emission. Initially, the cavity around the hot plasmoid expanded. Later, when the erupting plasmoid reached the height of an overlying arcade system, the plasmoid structure changed, and the lower parts of the cavity collapsed inwards. Hot loops appeared alongside and below the erupting plasmoid. We consider a scenario in which the fast waves and the type-II emission were a consequence of a flare blast wave, and the cavity collapse and the hot loops resulted from the break-out of the flux rope through an overlying coronal arcade.

  11. Multi-wavelength Observations of Two Explosive Events and Their Effects on the Solar Atmosphere

    Directory of Open Access Journals (Sweden)

    Agustinus G. Admiranto

    2016-09-01

    Full Text Available We investigated two flares in the solar atmosphere that occurred on June 3, 2012 and July 6, 2012 and caused propagation of Moreton and EIT waves. In the June 3 event, we noticed a filament winking which presumably was caused by the wave propagation from the flare. An interesting feature of this event is that there was a reflection of this wave by a coronal hole located alongside the wave propagation, but not all of this wave was transmitted by the coronal hole. Using the running difference method, we calculated the speed of Moreton and EIT waves and we found values of 926 km/s before the reflection and 276 km/s after the reflection (Moreton wave and 1,127 km/s before the reflection and 46 km/s after the reflection (EIT wave. In the July 6 event, this phenomenon was accompanied by type II and type III solar radio bursts, and we also performed a running difference analysis to find the speed of the Moreton wave, obtaining a value of 988 km/s. The speed derived from the analysis of the solar radio burst was 1,200 km/s, and we assume that this difference was caused by the different nature of the motions in these phenomena, where the solar radio burst was caused by the propagating particles, not waves.

  12. Multiwavelength observations of the energetic GRB 080810: detailed mapping of the broad-band spectral evolution

    NARCIS (Netherlands)

    Page, K.L.; Willingale, R.; Bissaldi, E.; de Ugarte Postigo, A.; Holland, S.T.; McBreen, S.; O'Brien, P.T.; Osborne, J.P.; Prochaska, J.X.; Rol, E.; Rykoff, E.S.; Starling, R.L.C.; Tanvir, N.R.; van der Horst, A.J.; Wiersema, K.; Zhang, B.; Aceituno, F.J.; Akerlof, C.; Beardmore, A.P.; Briggs, M.S.; Burrows, D.N.; Castro-Tirado, A.J.; Connaughton, V.; Evans, P.A.; Fynbo, J.P.U.; Gehrels, N.; Guidorzi, C.; Howard, A.W.; Kennea, J.A.; Kouveliotou, C.; Pagani, C.; Preece, R.; Perley, D.; Steele, I.A.; Yuan, F.

    2009-01-01

    GRB 080810 was one of the first bursts to trigger both Swift and the Fermi Gamma-ray Space Telescope. It was subsequently monitored over the X-ray and UV/optical bands by Swift, in the optical by Robotic Optical Transient Search Experiment (ROTSE) and a host of other telescopes, and was detected in

  13. Effective nonlinearities and multi-wavelength second-harmonic generation in modulated quasi-phase-matching gratings

    DEFF Research Database (Denmark)

    Bang, Ole; Graversen, T. W.; Clausen, Carl A. Balslev

    2000-01-01

    Quasi-phase-matching gratings induces Kerr effects in quadratic nonlinear materials. We show analytically and confirm numerically how modulating the grating changes the effective quadratic and cubic nonlinearities and allows for multi-wavelength second-harmonic generation.......Quasi-phase-matching gratings induces Kerr effects in quadratic nonlinear materials. We show analytically and confirm numerically how modulating the grating changes the effective quadratic and cubic nonlinearities and allows for multi-wavelength second-harmonic generation....

  14. Photonic crystal fibers used in a multi-wavelength source and as transmission fiber in a WDM system

    DEFF Research Database (Denmark)

    Andersen, Peter Andreas; Zsigri, Beata; Peucheret, Christophe

    2004-01-01

    We present a WDM system based entirely on photonic crystal fibers. It includes a novel dispersion flattened highly nonlinear PCF to generate supercontinuum used in a multiwavelength pulse source and a 5.6 km transmission PCF.......We present a WDM system based entirely on photonic crystal fibers. It includes a novel dispersion flattened highly nonlinear PCF to generate supercontinuum used in a multiwavelength pulse source and a 5.6 km transmission PCF....

  15. Multiwavelength Monitoring of the Enigmatic Narrow-Line Seyfert 1 PMN J0948 0022 in March-July 2009

    Energy Technology Data Exchange (ETDEWEB)

    Abdo, A.A.; /Naval Research Lab, Wash., D.C. /Federal City Coll.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Ajello, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Axelsson, M.; /Stockholm U. /Stockholm U., OKC; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, G.; /INFN, Trieste /Trieste U.; Bastieri, D.; /INFN, Padua /Padua U.; Baughman, B.M.; /Ohio State U.; Bechtol, K.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bellazzini, R. /INFN, Pisa; Berenji, B.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bloom, E.D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bonamente, E. /INFN, Perugia /Perugia U.; Borgland, A.W.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bregeon, J.; /INFN, Pisa; Brez, A.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari; Bruel, P.; /Ecole Polytechnique; Burnett, T.H.; /Washington U., Seattle; Caliandro, G.A.; /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /IASF, Milan /Milan Polytechnic /DAPNIA, Saclay /ASDC, Frascati /INFN, Perugia /Perugia U. /NASA, Goddard /NASA, Goddard /CSST, Baltimore /SISSA, Trieste /Naval Research Lab, Wash., D.C. /George Mason U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Montpellier U. /Garching, Max Planck Inst., MPE /Stockholm U. /Stockholm U., OKC /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /ASDC, Frascati /INFN, Trieste /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /CENBG, Gradignan /CENBG, Gradignan /Montpellier U. /Bari U. /INFN, Bari /Ecole Polytechnique /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Ecole Polytechnique /Brera Observ. /INFN, Trieste /Bonn, Max Planck Inst., Radioastron. /Hiroshima U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; /more authors..

    2012-03-29

    Following the recent discovery of {gamma} rays from the radio-loud narrow-line Seyfert 1 galaxy PMN J0948+0022 (z = 0.5846), we started a multiwavelength campaign from radio to {gamma} rays, which was carried out between the end of 2009 March and the beginning of July. The source displayed activity at all the observed wavelengths: a general decreasing trend from optical to {gamma}-ray frequencies was followed by an increase of radio emission after less than two months from the peak of the {gamma}-ray emission. The largest flux change, about a factor of about 4, occurred in the X-ray band. The smallest was at ultraviolet and near-infrared frequencies, where the rate of the detected photons dropped by a factor 1.6-1.9. At optical wavelengths, where the sampling rate was the highest, it was possible to observe day scale variability, with flux variations up to a factor of about 3. The behavior of PMN J0948+0022 observed in this campaign and the calculated power carried out by its jet in the form of protons, electrons, radiation, and magnetic field are quite similar to that of blazars, specifically of flat-spectrum radio quasars. These results confirm the idea that radio-loud narrow-line Seyfert 1 galaxies host relativistic jets with power similar to that of average blazars.

  16. All-fiber multi-wavelength passive Q-switched Er/Yb fiber laser based on a Tm-doped fiber saturable absorber

    Science.gov (United States)

    Posada-Ramírez, B.; Durán-Sánchez, M.; Álvarez-Tamayo, R. I.; Alaniz-Baylón, J.; Ibarra-Escamilla, B.; López-Estopier, R.; Kuzin, E. A.

    2017-03-01

    We report on a ring cavity, multi-wavelength, passive Q-switched erbium-ytterbium double cladding fiber laser based on the use of an unpumped segment of Tm-doped fiber acting as a saturable absorber for passive Q-switched pulse generation and a wavelength filter for multi-wavelength laser generation. By performing pump power variations from 1.6 to 9.8 W, stable Q-switched laser pulses are observed in a repetition rate from 135.8 to 27.5 kHz at room temperature. With a maximal repetition rate of 135.8 kHz, the minimum pulse duration of 430 ns is obtained. The maximal average output power of 2.2 W is reached with a pump power of 9.8 W. The maximum pulse energy was 16.4 µJ and the average output power slope efficiency is ~24.8%. The obtained results demonstrate a laser performance with extended range of high repetition rate and improved stability.

  17. Multi-wavelength campaign on NGC 7469. I. The rich 640 ks RGS spectrum

    Science.gov (United States)

    Behar, Ehud; Peretz, Uria; Kriss, Gerard A.; Kaastra, Jelle; Arav, Nahum; Bianchi, Stefano; Branduardi-Raymont, Graziella; Cappi, Massimo; Costantini, Elisa; De Marco, Barbara; Di Gesu, Laura; Ebrero, Jacobo; Kaspi, Shai; Mehdipour, Missagh; Paltani, Stéphane; Petrucci, Pierre-Olivier; Ponti, Gabriele; Ursini, Francesco

    2017-05-01

    Aims: Outflows in active galaxies (AGNs) are common, although their launching mechanism, location, and physical impact on the host galaxy remain controversial. We conducted a multi-wavelength six-month campaign to observe the nearby Seyfert galaxy NGC 7469 with several observatories in order to better understand and quantify the outflow in this AGN. Methods: We report on the time-integrated line-resolved X-ray spectrum of NGC 7469 obtained with the Reflection Grating Spectrometer (RGS) on board XMM-Newton. We used the RGS spectrum to discern the many AGN outflow components and applied a global fit to obtain their physical parameters. Results: We find that the AGN wind can be well described by three narrow velocity components at -650, -950, and -2050 km s-1. The RGS clearly resolves the -2050 km s-1 component in C5+ Ly α, while the -650 km s-1 and -950 km s-1 velocities are blended. Similar velocities (±200 km s-1) are resolved in the UV. The H-equivalent column densities of these components are, respectively, NH 7 × 1020, 2.2 × 1021, and 1020 cm-2, for a total of 3 × 1021 cm-2, which was also measured in 2004, indicating the absorber did not significantly change. The -650 km s-1 component shows a broad ionization distribution (-1 ≲ log ξ ≲ 2,ξ being the ionization parameter in erg s-1 cm). We identify a photo-ionized emission component blue-shifted by -450 km s-1, somewhat broad (FWHM = 1400 km s-1), and with -1 ≲ log ξ ≲ 1 erg s-1 cm, which we ascribe to the same outflow that produces the absorption lines. We also find a collisionally ionized component at kT = 0.35 keV that we associate with the circum-nuclear star-formation activity of NGC 7469, as it follows the LFIR/LX ≈ 104 relation found in star forming galaxies. The elemental abundance ratios of C, N, Ne, S, and Fe to O in the outflow tend to be between one and two times solar. Preliminary estimates of the absorber distance from the AGN center suggest it is at least a few pc away from the

  18. High energy optical parametric source for multi-wavelength CO2 dial

    Science.gov (United States)

    Barrientos-Barria, Jessica; Dherbecourt, Jean-Baptiste; Raybaut, Myriam; Godard, Antoine; Melkonian, Jean-Michel; Lefebvre, Michel

    2017-11-01

    In the scope of the preparation of spaceborne lidar missions to measure the concentration of greenhouse gases with differential absorption LIDAR techniques, we report on the development of a high energy 2.05 μm optical parametric source based on a versatile architecture enabling multiple wavelengths generation in the vicinity of the R30 absorption line of CO2. The multi-wavelength configuration is under study for a few greenhouse gas active detection missions, such as Ascend.

  19. The Multiwavelength Study of Two Unique Radio Galaxies Nectaria ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Abstract. We present the usage of multi-frequency and multi-band radio, VLA, observations as well as X-ray observations in order to study the environment around two powerful radio galaxies, namely Hercules A and 3 C310. We study their environment both in pc- and kpc-scales. We have chosen these two radio galaxies ...

  20. The Multiwavelength Study of Two Unique Radio Galaxies

    Indian Academy of Sciences (India)

    We present the usage of multi-frequency and multi-band radio, VLA, observations as well as X-ray observations in order to study the environment around two powerful radio galaxies, namely Hercules A and 3 C310. We study their environment both in pc- and kpc-scales. We have chosen these two radio galaxies as they ...

  1. EUV and Coronagraphic Observations of Coronal Mass Ejections

    Indian Academy of Sciences (India)

    The Large Angle Spectrometric Coronagraph (LASCO) and Extreme-ultraviolet Imaging Telescope (EIT) onboard Solar and Heliospheric Observatory (SOHO) provide us with unprecedented multi-wavelength observations helping us to understand different dynamic phenomena on the Sun and in the corona. In this paper ...

  2. T-PHOT: A new code for PSF-matched, prior-based, multiwavelength extragalactic deconfusion photometry

    Science.gov (United States)

    Merlin, E.; Fontana, A.; Ferguson, H. C.; Dunlop, J. S.; Elbaz, D.; Bourne, N.; Bruce, V. A.; Buitrago, F.; Castellano, M.; Schreiber, C.; Grazian, A.; McLure, R. J.; Okumura, K.; Shu, X.; Wang, T.; Amorín, R.; Boutsia, K.; Cappelluti, N.; Comastri, A.; Derriere, S.; Faber, S. M.; Santini, P.

    2015-10-01

    Context. The advent of deep multiwavelength extragalactic surveys has led to the necessity for advanced and fast methods for photometric analysis. In fact, codes which allow analyses of the same regions of the sky observed at different wavelengths and resolutions are becoming essential to thoroughly exploit current and future data. In this context, a key issue is the confusion (i.e. blending) of sources in low-resolution images. Aims: We present t-phot, a publicly available software package developed within the astrodeep project. t-phot is aimed at extracting accurate photometry from low-resolution images, where the blending of sources can be a serious problem for the accurate and unbiased measurement of fluxes and colours. Methods: t-phot can be considered as the next generation to tfit, providing significant improvements over and above it and other similar codes (e.g. convphot). t-phot gathers data from a high-resolution image of a region of the sky, and uses this information (source positions and morphologies) to obtain priors for the photometric analysis of the lower resolution image of the same field. t-phot can handle different types of datasets as input priors, namely i) a list of objects that will be used to obtain cutouts from the real high-resolution image; ii) a set of analytical models (as .fits stamps); iii) a list of unresolved, point-like sources, useful for example for far-infrared (FIR) wavelength domains. Results: By means of simulations and analysis of real datasets, we show that t-phot yields accurate estimations of fluxes within the intrinsic uncertainties of the method, when systematic errors are taken into account (which can be done thanks to a flagging code given in the output). t-phot is many times faster than similar codes like tfit and convphot (up to hundreds, depending on the problem and the method adopted), whilst at the same time being more robust and more versatile. This makes it an excellent choice for the analysis of large datasets

  3. Gemini Observations of Galaxies in Rich Early Environments (GOGREEN) I: survey description

    Science.gov (United States)

    Balogh, Michael L.; Gilbank, David G.; Muzzin, Adam; Rudnick, Gregory; Cooper, Michael C.; Lidman, Chris; Biviano, Andrea; Demarco, Ricardo; McGee, Sean L.; Nantais, Julie B.; Noble, Allison; Old, Lyndsay; Wilson, Gillian; Yee, Howard K. C.; Bellhouse, Callum; Cerulo, Pierluigi; Chan, Jeffrey; Pintos-Castro, Irene; Simpson, Rane; van der Burg, Remco F. J.; Zaritsky, Dennis; Ziparo, Felicia; Alonso, María Victoria; Bower, Richard G.; De Lucia, Gabriella; Finoguenov, Alexis; Lambas, Diego Garcia; Muriel, Hernan; Parker, Laura C.; Rettura, Alessandro; Valotto, Carlos; Wetzel, Andrew

    2017-10-01

    We describe a new Large Program in progress on the Gemini North and South telescopes: Gemini Observations of Galaxies in Rich Early Environments (GOGREEN). This is an imaging and deep spectroscopic survey of 21 galaxy systems at 1 10 in halo mass. The scientific objectives include measuring the role of environment in the evolution of low-mass galaxies, and measuring the dynamics and stellar contents of their host haloes. The targets are selected from the SpARCS, SPT, COSMOS, and SXDS surveys, to be the evolutionary counterparts of today's clusters and groups. The new red-sensitive Hamamatsu detectors on GMOS, coupled with the nod-and-shuffle sky subtraction, allow simultaneous wavelength coverage over λ ˜ 0.6-1.05 μm, and this enables a homogeneous and statistically complete redshift survey of galaxies of all types. The spectroscopic sample targets galaxies with AB magnitudes z΄ < 24.25 and [3.6] μm < 22.5, and is therefore statistically complete for stellar masses M* ≳ 1010.3 M⊙, for all galaxy types and over the entire redshift range. Deep, multiwavelength imaging has been acquired over larger fields for most systems, spanning u through K, in addition to deep IRAC imaging at 3.6 μm. The spectroscopy is ˜50 per cent complete as of semester 17A, and we anticipate a final sample of ˜500 new cluster members. Combined with existing spectroscopy on the brighter galaxies from GCLASS, SPT, and other sources, GOGREEN will be a large legacy cluster and field galaxy sample at this redshift that spectroscopically covers a wide range in stellar mass, halo mass, and clustercentric radius.

  4. Multiwavelength study of 20 jets that emanate from the periphery of active regions

    Science.gov (United States)

    Mulay, Sargam M.; Tripathi, Durgesh; Del Zanna, Giulio; Mason, Helen

    2016-05-01

    Aims: We present a multiwavelength analysis of 20 EUV jets which occurred at the periphery of active regions close to sunspots. We discuss the physical parameters of the jets and their relation with other phenomena such as Hα surges, nonthermal type-III radio bursts and hard X-ray (HXR) emission. Methods: These jets were observed between August 2010 and June 2013 by the Atmospheric Imaging Assembly (AIA) instrument that is onboard the Solar Dynamic Observatory (SDO). We selected events that were observed on the solar disk within +/-60° latitude. Using AIA wavelength channels that are sensitive to coronal temperatures, we studied the temperature distribution in the jets using the line of sight (LOS) differential emission measure (DEM) technique. We also investigated the role of the photospheric magnetic field using the LOS magnetogram data from the Helioseismic and Magnetic Imager (HMI) onboard SDO. Results: It has been observed that most of the jets originated from the western periphery of active regions. Their lifetimes range from 5 to 39 min with an average of 18 min and their velocities range from 87 to 532 km s-1 with an average of 271 km s-1. All the jets are co-temporally associated with Hα surges. Most of the jets are co-temporal with nonthermal type-III radio bursts observed by the Wind/WAVES spacecraft in the frequency range from 20 kHz to 13 MHz. We confirm the source region of these bursts using the potential field source surface (PFSS) technique. Using Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) observations, we found that half of the jets produced HXR emission and they often shared the same source region as the HXR emission (6-12 keV). Ten out of 20 events showed that the jets originated in a region of flux cancellation and six jets in a region of flux emergence. Four events showed flux emergence and then cancellation during the jet evolution. DEM analyses showed that for most of the spires of the jets, the DEM peaked at around log

  5. Studying the multi-wavelength signals from short GRBs

    NARCIS (Netherlands)

    Rowlinson, A.

    2013-01-01

    Since the first host galaxies and afterglows of short GRBs were identified, they have remained very difficult to study: their multiwavelenth afterglows are notoriously faint and host galaxy identification often relies upon minimalising a chance alignment probability. Despite these observational

  6. Probing the Massive Star-forming Environment: A Multiwavelength Investigation of the Filamentary IRDC G333.73+0.37

    Science.gov (United States)

    Veena, V. S.; Vig, S.; Mookerjea, B.; Sánchez-Monge, Á.; Tej, A.; Ishwara-Chandra, C. H.

    2018-01-01

    We present a multiwavelength study of the filamentary infrared dark cloud (IRDC) G333.73+0.37. The region contains two distinct mid-infrared sources S1 and S2 connected by dark lanes of gas and dust. Cold dust emission from the IRDC is detected at seven wavelength bands, and we have identified 10 high-density clumps in the region. The physical properties of the clumps such as temperature (14.3–22.3 K) and mass (87–1530 M ⊙) are determined by fitting a modified blackbody to the spectral energy distribution of each clump between 160 μm and 1.2 mm. The total mass of the IRDC is estimated to be ∼4700 M ⊙. The molecular line emission toward S1 reveals signatures of protostellar activity. Low-frequency radio emission at 1300 and 610 MHz is detected toward S1 (shell-like) and S2 (compact morphology), confirming the presence of newly formed massive stars in the IRDC. Photometric analysis of near- and mid-infrared point sources unveils the young stellar object population associated with the cloud. Fragmentation analysis indicates that the filament is supercritical. We observe a velocity gradient along the filament, which is likely to be associated with accretion flows within the filament rather than rotation. Based on various age estimates obtained for objects in different evolutionary stages, we attempt to set a limit to the current age of this cloud.

  7. Tunable and switchable Brillouin multi-wavelength thulium fluoride fiber laser in S/S+ band region

    Science.gov (United States)

    Ahmad, H.; Ooi, S. I.; Samion, M. Z.; Jasim, A. A.; Tiu, Z. C.

    2017-08-01

    In this work, a multi-wavelength fiber laser with a channel spacing of 0.17 nm operating in the S-band region is proposed and demonstrated. The proposed laser exploits the stimulated Brillouin scattering (SBS) effect to generate the desired output using a 6.9 km long dispersion shifted fiber. A Thulium-Fluoride fiber (TFF) pumped at 1400 nm enables gain and operation in the S-band region. With a Brillouin pump (BP) wavelength of 1503.6 nm and power of 12 dBm, up to 3 well defined even Stokes lines are obtained at the maximum pump power of 250 mW. Furthermore, more even Stokes lines and anti-Stokes lines are also observed at the afore-mentioned setting, although they are less well defined as the first 3 even Stokes. The laser has an operating range of 1470-1515 nm, with tunability enabled by changing the BP wavelength. Furthermore, the spacing between the lasing wavelengths can be switched from 0.17 nm to 0.08 nm by adjusting the integrated air gap in the laser cavity, making the proposed laser highly suitable for applications such as communications and sensing. This is, the first time to the author's knowledge that such a system has been demonstrated.

  8. Real-time imaging for cerebral ischemia in rats using the multi-wavelength handheld photoacoustic system

    Science.gov (United States)

    Liu, Yu-Hang; Xu, Yu; Chan, Kim Chuan; Mehta, Kalpesh; Thakor, Nitish; Liao, Lun-De

    2017-02-01

    Stroke is the second leading cause of death worldwide. Rapid and precise diagnosis is essential to expedite clinical decision and improve functional outcomes in stroke patients; therefore, real-time imaging plays an important role to provide crucial information for post-stroke recovery analysis. In this study, based on the multi-wavelength laser and 18.5 MHz array-based ultrasound platform, a real-time handheld photoacoustic (PA) system was developed to evaluate cerebrovascular functions pre- and post-stroke in rats. Using this system, hemodynamic information such as cerebral blood volume (CBV) can be acquired for assessment. One rat stroke model (i.e., photothrombotic ischemia (PTI)) was employed for evaluating the effect of local ischemia. For achieving better intrinsic PA contrast, Vantage and COMSOL simulations were applied to optimize the light delivery (e.g., interval between two arms) from customized fiber bundle, while phantom experiment was conducted to evaluate the imaging performance of this system. Results of phantom experiment showed that hairs ( 150 μm diameter) and pencil lead (500 μm diameter) can be imaged clearly. On the other hand, results of in vivo experiments also demonstrated that stroke symptoms can be observed in PTI model poststroke. In the near future, with the help of PA specific contrast agent, the system would be able to achieve blood-brain barrier leakage imaging post-stroke. Overall, the real-time handheld PA system holds great potential in disease models involving impairments in cerebrovascular functions.

  9. Optical outburst of 4C 38.41 (1633+382) observed by the GASP

    Science.gov (United States)

    Raiteri, C. M.; Villata, M.; Ehgamberdiev, Sh. A.; Mirzaqulov, D. O.; Holikov, Sh.

    2011-07-01

    The GLAST-AGILE Support Program (GASP) of the Whole Earth Blazar Telescope (WEBT) reports on the recent observation of a strong optical brightening of the gamma-loud quasar 4C 38.41. This is one of the 28 blazars for which the GASP performs a long-term, multiwavelength monitoring. In the current optical observing season, the source has shown multiwavelength activity (see also ATels #3238, #3333, #3335, #3360), so that the GASP has intensified the observations with a dedicated campaign (contact person: C.

  10. The 2009 multiwavelength campaign on Mrk 421: Variability and correlation studies

    Science.gov (United States)

    Aleksić, J.; Ansoldi, S.; Antonelli, L. A.; Antoranz, P.; Babic, A.; Bangale, P.; Barres de Almeida, U.; Barrio, J. A.; Becerra González, J.; Bednarek, W.; Berger, K.; Bernardini, E.; Biland, A.; Blanch, O.; Bock, R. K.; Bonnefoy, S.; Bonnoli, G.; Borracci, F.; Bretz, T.; Carmona, E.; Carosi, A.; Carreto Fidalgo, D.; Colin, P.; Colombo, E.; Contreras, J. L.; Cortina, J.; Covino, S.; Da Vela, P.; Dazzi, F.; De Angelis, A.; De Caneva, G.; De Lotto, B.; Delgado Mendez, C.; Doert, M.; Domínguez, A.; Dominis Prester, D.; Dorner, D.; Doro, M.; Einecke, S.; Eisenacher, D.; Elsaesser, D.; Farina, E.; Ferenc, D.; Fonseca, M. V.; Font, L.; Frantzen, K.; Fruck, C.; García López, R. J.; Garczarczyk, M.; Garrido Terrats, D.; Gaug, M.; Giavitto, G.; Godinović, N.; González Muñoz, A.; Gozzini, S. R.; Hadamek, A.; Hadasch, D.; Herrero, A.; Hildebrand, D.; Hose, J.; Hrupec, D.; Idec, W.; Kadenius, V.; Kellermann, H.; Knoetig, M. L.; Krause, J.; Kushida, J.; La Barbera, A.; Lelas, D.; Lewandowska, N.; Lindfors, E.; Longo, F.; Lombardi, S.; López, M.; López-Coto, R.; López-Oramas, A.; Lorenz, E.; Lozano, I.; Makariev, M.; Mallot, K.; Maneva, G.; Mankuzhiyil, N.; Mannheim, K.; Maraschi, L.; Marcote, B.; Mariotti, M.; Martínez, M.; Mazin, D.; Menzel, U.; Meucci, M.; Miranda, J. M.; Mirzoyan, R.; Moralejo, A.; Munar-Adrover, P.; Nakajima, D.; Niedzwiecki, A.; Nilsson, K.; Nowak, N.; Orito, R.; Overkemping, A.; Paiano, S.; Palatiello, M.; Paneque, D.; Paoletti, R.; Paredes, J. M.; Paredes-Fortuny, X.; Partini, S.; Persic, M.; Prada, F.; Prada Moroni, P. G.; Prandini, E.; Preziuso, S.; Puljak, I.; Reinthal, R.; Rhode, W.; Ribó, M.; Rico, J.; RodriguezGarcia, J.; Rügamer, S.; Saggion, A.; Saito, K.; Salvati, M.; Satalecka, K.; Scalzotto, V.; Scapin, V.; Schultz, C.; Schweizer, T.; Shore, S. N.; Sillanpää, A.; Sitarek, J.; Snidaric, I.; Sobczynska, D.; Spanier, F.; Stamatescu, V.; Stamerra, A.; Steinbring, T.; Storz, J.; Sun, S.; Surić, T.; Takalo, L.; Tavecchio, F.; Temnikov, P.; Terzić, T.; Tescaro, D.; Teshima, M.; Thaele, J.; Tibolla, O.; Torres, D. F.; Toyama, T.; Treves, A.; Uellenbeck, M.; Vogler, P.; Wagner, R. M.; Zandanel, F.; Zanin, R.; MAGIC Collaboration; Archambault, S.; Behera, B.; Beilicke, M.; Benbow, W.; Bird, R.; Buckley, J. H.; Bugaev, V.; Cerruti, M.; Chen, X.; Ciupik, L.; Collins-Hughes, E.; Cui, W.; Dumm, J.; Eisch, J. D.; Falcone, A.; Federici, S.; Feng, Q.; Finley, J. P.; Fleischhack, H.; Fortin, P.; Fortson, L.; Furniss, A.; Griffin, S.; Griffiths, S. T.; Grube, J.; Gyuk, G.; Hanna, D.; Holder, J.; Hughes, G.; Humensky, T. B.; Johnson, C. A.; Kaaret, P.; Kertzman, M.; Khassen, Y.; Kieda, D.; Krawczynski, H.; Krennrich, F.; Kumar, S.; Lang, M. J.; Maier, G.; McArthur, S.; Meagher, K.; Moriarty, P.; Mukherjee, R.; Ong, R. A.; Otte, A. N.; Park, N.; Pichel, A.; Pohl, M.; Popkow, A.; Prokoph, H.; Quinn, J.; Ragan, K.; Rajotte, J.; Reynolds, P. T.; Richards, G. T.; Roache, E.; Rovero, A. C.; Sembroski, G. H.; Shahinyan, K.; Staszak, D.; Telezhinsky, I.; Theiling, M.; Tucci, J. V.; Tyler, J.; Varlotta, A.; Wakely, S. P.; Weekes, T. C.; Weinstein, A.; Welsing, R.; Wilhelm, A.; Williams, D. A.; Zitzer, B.; VERITAS Collaboration; Villata, M.; Raiteri, C.; Aller, H. D.; Aller, M. F.; Chen, W. P.; Jordan, B.; Koptelova, E.; Kurtanidze, O. M.; Lähteenmäki, A.; McBreen, B.; Larionov, V. M.; Lin, C. S.; Nikolashvili, M. G.; Angelakis, E.; Capalbi, M.; Carramiñana, A.; Carrasco, L.; Cassaro, P.; Cesarini, A.; Fuhrmann, L.; Giroletti, M.; Hovatta, T.; Krichbaum, T. P.; Krimm, H. A.; Max-Moerbeck, W.; Moody, J. W.; Maccaferri, G.; Mori, Y.; Nestoras, I.; Orlati, A.; Pace, C.; Pearson, R.; Perri, M.; Readhead, A. C. S.; Richards, J. L.; Sadun, A. C.; Sakamoto, T.; Tammi, J.; Tornikoski, M.; Yatsu, Y.; Zook, A.

    2015-04-01

    Aims: We perform an extensive characterization of the broadband emission of Mrk 421, as well as its temporal evolution, during the non-flaring (low) state. The high brightness and nearby location (z = 0.031) of Mrk 421 make it an excellent laboratory to study blazar emission. The goal is to learn about the physical processes responsible for the typical emission of Mrk 421, which might also be extended to other blazars that are located farther away and hence are more difficult to study. Methods: We performed a 4.5-month multi-instrument campaign on Mrk 421 between January 2009 and June 2009, which included VLBA, F-GAMMA, GASP-WEBT, Swift, RXTE, Fermi-LAT, MAGIC, and Whipple, among other instruments and collaborations. This extensive radio to very-high-energy (VHE; E> 100 GeV) γ-ray dataset provides excellent temporal and energy coverage, which allows detailed studies of the evolution of the broadband spectral energy distribution. Results: Mrk421 was found in its typical (non-flaring) activity state, with a VHE flux of about half that of the Crab Nebula, yet the light curves show significant variability at all wavelengths, the highest variability being in the X-rays. We determined the power spectral densities (PSD) at most wavelengths and found that all PSDs can be described by power-laws without a break, and with indices consistent with pink/red-noise behavior. We observed a harder-when-brighter behavior in the X-ray spectra and measured a positive correlation between VHE and X-ray fluxes with zero time lag. Such characteristics have been reported many times during flaring activity, but here they are reported for the first time in the non-flaring state. We also observed an overall anti-correlation between optical/UV and X-rays extending over the duration of the campaign. Conclusions: The harder-when-brighter behavior in the X-ray spectra and the measured positive X-ray/VHE correlation during the 2009 multi-wavelength campaign suggests that the physical processes

  11. Calibrating the Near-Infrared Tip of the Red Giant Branch with Multiwavelength Photometry

    Science.gov (United States)

    Durbin, Meredith

    2017-08-01

    The near-infrared (NIR) tip of the red giant branch (TRGB) shows outstanding promise as a distance indicator. In the JWST era, the NIR-TRGB will bridge the gap from local geometric parallax (with Gaia) out to the low-velocity Hubble flow in a single step, in all types of galaxies. However, there currently exist several impediments to JWST's using the TRGB to full advantage. Dalcanton et al. (2012) presented the most comprehensive dataset available for calibrating the TRGB absolute magnitude, with optical and NIR coverage of 23 nearby dwarf and spiral galaxies spanning a wide range of ages and metallicities. However, subtle offsets between this dataset, theoretical models, and globular clusters raise concerns about the calibration.We propose to perform a complete re-reduction and re-analysis of this dataset. We have developed a pipeline that leverages simultaneous fitting of optical and NIR data to produce NIR photometry of higher quality and completeness, with up to 1.5 mag greater depth than can be achieved with the NIR alone. With this added depth, improvements in photometric precision, and updated WFC3/IR PSFs and flux calibration, we will derive uniform, precise, and accurate NIR TRGB measurements, with which we will be able to resolve standing issues with the TRGB color-absolute magnitude relation and its behavior with changing star-formation histories. This work will lay the groundwork for extending the TRGB distance scale out to at least 37 Mpc with JWST. We will release the resulting 4-filter optical-NIR photometry as HLSPs for use by the community before the launch of JWST, to serve as a resource for proposing for stellar population observations in the NIR.

  12. Multi-Wavelength Variability in PKS 2155-304

    Indian Academy of Sciences (India)

    In this model, a homogeneously and isotropically spherical structure is assumed, the Fokker–Planck type equation which describes the evolution of the particles energy is numerically solved, and the synchrotron and self-Compton components from the spherical blob are calculated. Our results can reproduce observed ...

  13. Dark matter indirect searches: Multi-wavelength and anisotropies

    NARCIS (Netherlands)

    Ando, S.

    2016-01-01

    If dark matter is made of particles governed by weak-scale physics, they may annihilate or decay to leave observable signatures in high-energy gamma-ray sky. In addition, any charged particles produced by the same process will also give low-frequency photons through successive electromagnetic

  14. 2005–2010 Multiwavelength Campaing of OJ287

    Directory of Open Access Journals (Sweden)

    M. Valtonen

    2011-01-01

    Full Text Available The light curve of quasar OJ287 extends from 1891 up today without major gaps. This is partly due to extensive studies of historical plate archives by Rene Hudec and associates, and partly due to several observing campaigns in recent times. Here we summarize the results of the 2005–2010 observing campaign, in which several hundred scientists and amateur astronomers took part. The main results are the following: (1 The 2005 October optical outburst came at the expected time, thus confirming the General Relativistic precession in the binary black hole system, as was originally proposed bySillanp¨a¨a et al. (1988. At the same time, this result disproved the model of a single black hole system with accretion disk oscillations, as well as several toy models of binaries without relativistic precession. In the latter models the main outburst would have been a year later. No particular activity was seen in OJ287 in 2006 October. (2 The nature of the radiation of the 2005 October outburst was expected to be bremsstrahlung from hot gas at a temperature of 3 × 105 K. The reason for the outburst is a collision of the secondary on the accretion disk of the primary, which heats the gas to this temperature. This was confirmed by combined ground based and ultraviolet observations using the XMM-Newton X-ray telescope. (3 A secondary outburst of the same nature was expected at 2007 September 13. Within the accuracy of the observations (about 6 hours, it started at the correct time. Thus the prediction was accurate at the same level as the prediction of the return of Halley’s comet in 1986. Due to the bremsstrahlung nature of the outburst, the radiation was unpolarised, as expected. (4 Further synchrotron outbursts were expected following the two bremsstrahlung outbursts.They came as scheduled between 2007 October and 2009 December. (5 Due to the effect of the secondary on the overall direction of the jet, the parsec scale jet was expected to rotate in the

  15. Multiwavelength Pyrometer Developed for Use at Elevated Temperatures in Aerospace Applications

    Science.gov (United States)

    Ng, Daniel L.

    2003-01-01

    Researchers at the NASA Glenn Research Center have developed a unique multiwavelength pyrometer for aerospace applications. It has been shown to be a useful and versatile instrument for measuring the surface temperatures of ceramic zirconia thermal barrier coatings (TBCs) and alumina, even when their emissivity is unknown. The introduction of fiber optics into the pyrometer has greatly increased the ease of using this instrument. Direct comparison of measurements obtained using the pyrometer and thin film thermocouples on a sample provided independent verification of pyrometry temperature measurement. Application of the pyrometer has also included simultaneous surface and bulk temperature measurement in a transparent material, the measurement of combustion gas temperatures in the flames of an atmospheric burner, the measurement of the temperature distribution appearing on a large surface from the recording of just a single radiation spectrum emitted from this nonuniform temperature surface, and the measurement of some optical properties for special aeronautical materials-such as nanostructured layers. The multiwavelength pyrometer temperature is obtained from a radiation spectrum recorded over a broad wavelength region by transforming it into a straight line segment(s) in part or all of the spectral region. The intercept of the line segment(s) with the vertical axis at zero wavelength gives the inverse of the temperature. In a two-color pyrometer, the two data points are also amenable to this analysis to determine the unknown temperature. Implicit in a two-color pyrometer is the assumption of wavelength-independent emissivity. Its two (and minimum) pieces of data are sufficient to determine this straight line. However, a multiwavelength pyrometer not only has improved accuracy but also confirms that the wavelength-independent emissivity assumption is valid when a multitude of data points are shown to lie on a simple straight line.

  16. A multi-wavelength fiber laser based on superimposed fiber grating and chirp fiber Bragg grating for wavelength selection

    Science.gov (United States)

    Wang, Feng; Bi, Wei-hong; Fu, Xing-hu; Jiang, Peng; Wu, Yang

    2015-11-01

    In this paper, a new type of multi-wavelength fiber laser is proposed and demonstrated experimentally. Superimposed fiber grating (SIFG) and chirp fiber Bragg grating (CFBG) are used for wavelength selection. Based on gain equalization technology, by finely adjusting the stress device in the cavity, the gain and loss are equal, so as to suppress the modal competition and achieve multi-wavelength lasing at room temperature. The experimental results show that the laser can output stable multi-wavelength lasers simultaneously. The laser coupling loss is small, the structure is simple, and it is convenient for integration, so it can be widely used in dense wavelength division multiplexing (DWDM) system and optical fiber sensors.

  17. A linearly frequency-swept high-speed-rate multi-wavelength laser for optical coherence tomography

    Science.gov (United States)

    Wang, Qiyu; Wang, Zhaoying; Yuan, Quan; Ma, Rui; Du, Tao; Yang, Tianxin

    2017-02-01

    We proposed and demonstrated a linearly frequency-swept multi-wavelength laser source for optical coherence tomography (OCT) eliminating the need of wavenumber space resampling in the postprocessing progress. The source consists of a multi-wavelength fiber laser source (MFS) and an optical sweeping loop. In this novel laser source, an equally spaced multi-wavelength laser is swept simultaneously by a certain step each time in the frequency domain in the optical sweeping loop. The sweeping step is determined by radio frequency (RF) signal which can be precisely controlled. Thus the sweeping behavior strictly maintains a linear relationship between time and frequency. We experimentally achieved linear time-frequency sweeping at a sweeping rate of 400 kHz with our laser source.

  18. ArylexTM active – new herbicide active and base for new cereals herbicides: ZyparTM and Pixxaro™ EC to control wide range of broadleaf weeds in cereals in Europe

    Directory of Open Access Journals (Sweden)

    Dzikowski, Marcin

    2016-02-01

    Full Text Available Arylex™ active is a new auxinic herbicide for postemergence control of a range of important broadleaf weeds in cereals. It has been discovered and developed by Dow AgroSciences globally as a first member of the new ‘arylpicolinate‘ structural class. Arylex applied together with safener brings excellent crop safety and due to the rapid degradation in soil and plant tissue it does not limit the following crop choice. In Europe the first two herbicides containing this active are Zypar™ and Pixxaro™ EC. Zypar is a premix of Arylex and florasulam, delivering at the 1 L/ha maximum use rate 6 g ae/ha of Arylex and 5 g/ha of florasulam. It can be applied to all cereals, apart from oats, in autumn and spring. Spring application is allowed from BBCH 13 till BBCH 45, however the best performance is reached up to BBCH 32. Zypar’s spectrum of controlled weeds is very wide. Pixxaro EC is a combination of Arylex and fluroxypyr and at 0.5 l/ha dose rate delivers 6 g ae/ha of Arylex and 140 g ae/ha of fluroxypyr. It can be applied in all cereals, apart from oats, in spring from BBCH 13 till BBCH 45, while the best performance is observed between BBCH 30 and 45. Pixxaro EC shows excellent efficacy against key weeds, especially Galium aparine and at all growth stages. This herbicide brings a novel non-ALS solution and will be a key component of anti-resistance strategies for broadleaf weeds in cereals.

  19. Reliability of temperature determination from curve-fitting in multi-wavelength pyrometery

    Energy Technology Data Exchange (ETDEWEB)

    Ni, P. A.; More, R. M.; Bieniosek, F. M.

    2013-08-04

    Abstract This paper examines the reliability of a widely used method for temperature determination by multi-wavelength pyrometry. In recent WDM experiments with ion-beam heated metal foils, we found that the statistical quality of the fit to the measured data is not necessarily a measure of the accuracy of the inferred temperature. We found a specific example where a second-best fit leads to a more realistic temperature value. The physics issue is the wavelength-dependent emissivity of the hot surface. We discuss improvements of the multi-frequency pyrometry technique, which will give a more reliable determination of the temperature from emission data.

  20. Multi-wavelengths digital holography: reconstruction, synthesis and display of holograms using adaptive transformation.

    Science.gov (United States)

    Memmolo, P; Finizio, A; Paturzo, M; Ferraro, P; Javidi, B

    2012-05-01

    A method based on spatial transformations of multiwavelength digital holograms and the correlation matching of their numerical reconstructions is proposed, with the aim to improve superimposition of different color reconstructed images. This method is based on an adaptive affine transform of the hologram that permits management of the physical parameters of numerical reconstruction. In addition, we present a procedure to synthesize a single digital hologram in which three different colors are multiplexed. The optical reconstruction of the synthetic hologram by a spatial light modulator at one wavelength allows us to display all color features of the object, avoiding loss of details.

  1. Switchable multi-wavelength Tm-doped mode-locked fiber laser.

    Science.gov (United States)

    Yan, Zhiyu; Tang, Yulong; Sun, Biao; Liu, Tao; Li, Xiaohui; Ping, Perry Shum; Yu, Xia; Zhang, Ying; Wang, Qi Jie

    2015-05-01

    We propose and demonstrate for the first time a switchable tri-wavelength Tm-doped ultra-fast fiber laser based on nonlinear polarization evolution (NPE) technique. The NPE effect induces wavelength-dependent loss in the cavity that changes the homogeneous broadening of the effective gain to become inhomogeneous. This inhomogeneous effective gain spectral profile enables the multi-wavelength mode locking. Binary control of three bits can be realized by controlling the polarization in the compact fiber ring cavity. Such switchable laser has potential applications in optical signal processing and communication.

  2. Remote Heat Flux Using a Self Calibration Multiwavelength Pyrometer and a Transparent Material

    Science.gov (United States)

    Ng, Daniel

    1998-01-01

    A self calibrating multiwavelength pyrometer was used to conduct remote heat flux measurements using a transparent sapphire disk by determining the sapphire disk's front and back surface temperatures. Front surface temperature (Tfs) was obtained from detection of surface emitted radiation at long wavelengths (k = 6 gm). Back surface temperature (Tbs) was obtained from short wavelength (1 to 5 gm) radiation transmitted through the sapphire disk. The thermal conductivity of the sapphire disk and the heat transfer coefficients h, and h2 of its surfaces are determined experimentally. An analysis of the heat flux measurement is presented.

  3. Remote Heat Flux Measurement Using a Self Calibration Multiwavelength Pyrometer and a Transparent Material

    Science.gov (United States)

    Ng, Daniel

    1998-01-01

    A self calibrating multiwavelength pyrometer was used to conduct remote heat flux measurements using a transparent sapphire disk by determining the sapphire disk's front and back surface temperatures. Front surface temperature (Tfs) was obtained from detection of surface emitted radiation at long wavelengths (lambda > 6 micrometers). Back surface temperature (Tbs) was obtained from short wavelength (1 to 5 micrometers) radiation transmitted through the sapphire disk. The thermal conductivity k of the sapphire disk and the heat transfer coefficients h(sub 1) and h(sub 2) of its surfaces are determined experimentally. An analysis of the heat flux measurement is presented.

  4. Monolithically integrated multi-wavelength VCSEL arrays using high-contrast gratings.

    Science.gov (United States)

    Karagodsky, Vadim; Pesala, Bala; Chase, Christopher; Hofmann, Werner; Koyama, Fumio; Chang-Hasnain, Connie J

    2010-01-18

    We propose a novel design for multi-wavelength arrays of vertical cavity surface-emitting lasers (VCSELs) using high-contrast gratings (HCGs) as top mirrors. A range of VCSEL cavity wavelengths in excess of 100 nm is predicted by modifying only the period and duty-cycle of the high-contrast gratings, while leaving the epitaxial layer thickness unchanged. VCSEL arrays fabricated with this novel design can easily accommodate the entire Er-doped fiber amplifier bandwidth with emission wavelengths defined solely by lithography with no restrictions in physical layout. Further, the entire process is identical to that of solitary VCSELs, facilitating cost-effective manufacturing.

  5. Principal component analysis applied to multiwavelength lidar aerosol backscatter and extinction measurements.

    Science.gov (United States)

    Donovan, D P; Carswell, A I

    1997-12-20

    The use of powerful Raman backscatter lidars enables one to measure the stratospheric aerosol extinction profile independently of the backscatter, thereby obtaining additional information to aid in retrieving the physical characteristics of the sampled aerosol. We used principal component analysis to construct a self-consistent method for the retrieval of aerosol bulk physical and optical properties from multiwavelength elastic and/or inelastic Raman backscatter lidar signals. The procedure is applied to synthetic and actual lidar signals. We found that aerosol surface area and volume can be usefully estimated and that the use of Raman-derived extinction data leads to a notable improvement in the accuracy of the estimations.

  6. Multi-wavelength mid-IR light source for gas sensing

    Science.gov (United States)

    Karioja, Pentti; Alajoki, Teemu; Cherchi, Matteo; Ollila, Jyrki; Harjanne, Mikko; Heinilehto, Noora; Suomalainen, Soile; Viheriälä, Jukka; Zia, Nouman; Guina, Mircea; Buczyński, Ryszard; Kasztelanic, Rafał; Kujawa, Ireneusz; Salo, Tomi; Virtanen, Sami; Kluczyński, Paweł; Sagberg, Hâkon; Ratajczyk, Marcin; Kalinowski, Przemyslaw

    2017-02-01

    Cost effective multi-wavelength light sources are key enablers for wide-scale penetration of gas sensors at Mid-IR wavelength range. Utilizing novel Mid-IR Si-based photonic integrated circuits (PICs) filter and wide-band Mid-IR Super Luminescent Light Emitting Diodes (SLEDs), we show the concept of a light source that covers 2.5…3.5 μm wavelength range with a resolution of market impact is expected to be disruptive, since the devices currently in the market are either complicated, expensive and heavy instruments, or the applied measurement principles are inadequate in terms of stability and selectivity.

  7. TW Hydrae: multi-wavelength interferometry of a transition disk

    Science.gov (United States)

    Menu, J.; van Boekel, R.; Henning, T.; Benisty, M.; Chandler, C. J.; Linz, H.; Waelkens, C.; Andrews, S. M.; Calvet, N.; Carpenter, J. M.; Corder, S. A.; Deller, A. T.; Dullemond, C. P.; Greaves, J. S.; Harris, R. J.; Isella, A.; Kwon, W.; Lazio, J.; Mundy, L. G.; Perez, L. M.; Ricci, L.; Sargent, A. I.; Storm, S.; Testi, L.; Wilner, D. J.

    2014-01-01

    For over a decade, the structure of the inner ``hole'' in the transition disk around TW Hydrae has been a subject of debate. To probe the innermost regions of the protoplanetary disk, observations at the highest possible spatial resolution are required. We present new interferometric data of TW Hya from near-infrared to millimeter wavelengths. We confront existing models of the disk structure with the complete data set and develop a new, detailed radiative-transfer model. This model is characterized by: 1) a spatial separation of the largest grains from the small disk grains; and 2) a smooth inner rim structure, rather than a sharp disk edge.

  8. Multiwavelength temporal and spectral variability of the blazar OJ 287 during and after the 2015 December flare: a major accretion disc contribution

    Science.gov (United States)

    Kushwaha, Pankaj; Gupta, Alok C.; Wiita, Paul J.; Gaur, Haritma; de Gouveia Dal Pino, E. M.; Bhagwan, Jai; Kurtanidze, O. M.; Larionov, V. M.; Damljanovic, G.; Uemura, M.; Semkov, E.; Strigachev, A.; Bachev, R.; Vince, O.; Gu, Minfeng; Zhang, Z.; Abe, T.; Agarwal, A.; Borman, G. A.; Fan, J. H.; Grishina, T. S.; Hirochi, J.; Itoh, R.; Kawabata, M.; Kopatskaya, E. N.; Kurtanidze, S. O.; Larionova, E. G.; Larionova, L. V.; Mishra, A.; Morozova, D. A.; Nakaoka, T.; Nikolashvili, M. G.; Savchenko, S. S.; Troitskaya, Yu. V.; Troitsky, I. S.; Vasilyev, A. A.

    2018-01-01

    We present a multiwavelength spectral and temporal analysis of the blazar OJ 287 during its recent activity between 2015 December and 2016 May, showing strong variability in the near-infrared (NIR) to X-ray energies with detection at γ-ray energies as well. Most of the optical flux variations exhibit strong changes in polarization angle and degree. All the interband time lags are consistent with simultaneous emissions. Interestingly, on days with excellent data coverage in the NIR-UV bands, the spectral energy distributions (SEDs) show signatures of bumps in the visible-UV bands, never seen before in this source. The optical bump can be explained as accretion-disc emission associated with the primary black hole of mass ∼ 1.8 × 1010 M⊙ while the little bump feature in the optical-UV appears consistent with line emission. Further, the broad-band SEDs extracted during the first flare and during a quiescent period during this span show very different γ-ray spectra compared to previously observed flare or quiescent spectra. The probable thermal bump in the visible seems to have been clearly present since 2013 May, as found by examining all available NIR-optical observations, and favours the binary supermassive black hole model. The simultaneous multiwavelength variability and relatively weak γ-ray emission that shows a shift in the SED peak is consistent with γ-ray emission originating from inverse Compton scattering of photons from the line emission that apparently contributes to the little blue bump.

  9. Magnetism Matters: Coronal Magnetometry Using Multi-Wavelength Polarimetry

    Science.gov (United States)

    Gibson, Sarah E.

    2015-08-01

    The solar coronal magnetic field is key both to solving fundamental problems in solar physics such as coronal heating and solar wind acceleration, and to predicting the internal magnetic structure and thus space-weather impact of coronal mass ejections. I will describe the current state of the art in coronal magnetometry, and present results from the Coronal Multichannel Polarimeter (CoMP) at Mauna Loa Solar Observatory (MLSO), which since 2011 has taken polarimetric observations of the solar corona in the near-infrared on a near-daily basis. I will discuss work in progress that utilizes forward modeling to synthesize polarimetric data at multiple heights and vantage points, and at wavelengths from radio to infrared to visible to ultraviolet. The goal is to use such synthetic testbeds to determine the ideal set of observations for constraining the coronal magnetic field, and to establish a Data-Optimized Coronal Field Model (DOC-FM) that efficiently incorporates these data into global magnetic models. This work will provide essential tools and motivation for the planning and implementation of future coronal polarimetric projects and missions spanning a broad range of wavelengths.

  10. Removal of a wide range of emerging pollutants from wastewater treatment plant discharges by micro-grain activated carbon in fluidized bed as tertiary treatment at large pilot scale

    Energy Technology Data Exchange (ETDEWEB)

    Mailler, R., E-mail: romain.mailler@siaap.fr [LEESU (UMR MA 102, Université Paris-Est, AgroParisTech), Université Paris-Est Créteil, 61 avenue du Général de Gaulle, 94010 Créteil Cedex (France); Gasperi, J., E-mail: gasperi@u-pec.fr [LEESU (UMR MA 102, Université Paris-Est, AgroParisTech), Université Paris-Est Créteil, 61 avenue du Général de Gaulle, 94010 Créteil Cedex (France); Coquet, Y. [SAUR, Direction de la Recherche et du Développement, 1 rue Antoine Lavoisier, 78064 Guyancourt (France); Buleté, A.; Vulliet, E. [Université de Lyon, Institut des Sciences Analytiques, UMR5280 CNRS, Université Lyon 1, ENS-Lyon, 5 rue de la Doua, 69100 Villeurbanne (France); Deshayes, S. [LEESU (UMR MA 102, Université Paris-Est, AgroParisTech), Université Paris-Est Créteil, 61 avenue du Général de Gaulle, 94010 Créteil Cedex (France); LCPP (Laboratoire Central de la Préfecture de Police), 39 bis rue de Dantzig, 75015 Paris (France); Zedek, S. [LEESU (UMR MA 102, Université Paris-Est, AgroParisTech), Université Paris-Est Créteil, 61 avenue du Général de Gaulle, 94010 Créteil Cedex (France); and others

    2016-01-15

    Among the solutions to reduce micropollutant discharges into the aquatic environment, activated carbon adsorption is a promising technique and a large scale pilot has been tested at the Seine Centre (240,000 m{sup 3}/d — Paris, France) wastewater treatment plant (WWTP). While most of available works studied fixed bed or contact reactors with a separated separation step, this study assesses a new type of tertiary treatment based on a fluidized bed containing a high mass of activated carbon, continuously renewed. For the first time in the literature, micro-grain activated carbon (μGAC) was studied. The aims were (1) to determine the performances of fluidized bed operating with μCAG on both emerging micropollutants and conventional wastewater quality parameters, and (2) to compare its efficiency and applicability to wastewater to former results obtained with PAC. Thus, conventional wastewater quality parameters (n = 11), pharmaceuticals and hormones (PPHs; n = 62) and other emerging pollutants (n = 57) have been monitored in μGAC configuration during 13 campaigns. A significant correlation has been established between dissolved organic carbon (DOC), PPHs and UV absorbance at 254 nm (UV-254) removals. This confirms that UV-254 could be used as a tertiary treatment performance indicator to monitor the process. This parameter allowed identifying that the removals of UV-254 and DOC reach a plateau from a μGAC retention time (SRT) of 90–100 days. The μGAC configuration substantially improves the overall quality of the WWTP discharges by reducing biological (38–45%) and chemical oxygen demands (21–48%), DOC (13–44%) and UV-254 (22–48%). In addition, total suspended solids (TSS) are retained by the μGAC bed and a biological activity (nitratation) leads to a total elimination of NO{sub 2}{sup −}. For micropollutants, PPHs have a good affinity for μGAC and high (> 60%) or very high (> 80%) removals are observed for most of the quantified compounds (n = 22

  11. Removal of a wide range of emerging pollutants from wastewater treatment plant discharges by micro-grain activated carbon in fluidized bed as tertiary treatment at large pilot scale.

    Science.gov (United States)

    Mailler, R; Gasperi, J; Coquet, Y; Buleté, A; Vulliet, E; Deshayes, S; Zedek, S; Mirande-Bret, C; Eudes, V; Bressy, A; Caupos, E; Moilleron, R; Chebbo, G; Rocher, V

    2016-01-15

    Among the solutions to reduce micropollutant discharges into the aquatic environment, activated carbon adsorption is a promising technique and a large scale pilot has been tested at the Seine Centre (240,000 m(3)/d - Paris, France) wastewater treatment plant (WWTP). While most of available works studied fixed bed or contact reactors with a separated separation step, this study assesses a new type of tertiary treatment based on a fluidized bed containing a high mass of activated carbon, continuously renewed. For the first time in the literature, micro-grain activated carbon (μGAC) was studied. The aims were (1) to determine the performances of fluidized bed operating with μCAG on both emerging micropollutants and conventional wastewater quality parameters, and (2) to compare its efficiency and applicability to wastewater to former results obtained with PAC. Thus, conventional wastewater quality parameters (n=11), pharmaceuticals and hormones (PPHs; n=62) and other emerging pollutants (n=57) have been monitored in μGAC configuration during 13 campaigns. A significant correlation has been established between dissolved organic carbon (DOC), PPHs and UV absorbance at 254 nm (UV-254) removals. This confirms that UV-254 could be used as a tertiary treatment performance indicator to monitor the process. This parameter allowed identifying that the removals of UV-254 and DOC reach a plateau from a μGAC retention time (SRT) of 90-100 days. The μGAC configuration substantially improves the overall quality of the WWTP discharges by reducing biological (38-45%) and chemical oxygen demands (21-48%), DOC (13-44%) and UV-254 (22-48%). In addition, total suspended solids (TSS) are retained by the μGAC bed and a biological activity (nitratation) leads to a total elimination of NO2(-). For micropollutants, PPHs have a good affinity for μGAC and high (>60%) or very high (>80%) removals are observed for most of the quantified compounds (n=22/32), i.e. atenolol (92

  12. Multi-wavelength and multiband RE-doped optical fiber source array for WDM-GPON applications

    Science.gov (United States)

    Perez-Sanchez, G. G.; Bertoldi-Martins, I.; Gallion, P.; Gosset, C.; Álvarez-Chávez, J. A.

    2013-12-01

    In this paper, a multiband, multi-wavelength, all-fibre source array consisting of an 810nm pump laser diode, thretwo fiber splitters and three segments of Er-, Tm- and Nd-doped fiber is proposed for PON applications. In the set-up, cascaded pairs of standard fiber gratings are used for extracting the required multiple wavelengths within their corresponding bands. A thorough design parameter description, optical array details and full simulation results, such as: full multi-wavelength spectrum, peak and average powers for each generated wavelength, linewidth at FWHM for each generated signal, and individual and overall conversion efficiency, will be included in the manuscript.

  13. Dental pulp vitality measurement based on multiwavelength photoplethysmography

    Science.gov (United States)

    Sarkela, Ville; Kopola, Harri K.; Oikarinen, Kyosti; Herrala, Esko

    1995-01-01

    Observation of the intradental blood supply is important in cases of dental trauma, but difficult. As the methods used by dentists to measure pulp vitality are not very reliable, a dental pulp vitalometer based on fiberoptic reflectance measurement and measurement of the absorption of blood has been designed and built. In addition to the fiber optic probe and reflectance sensor electronics, the vitalometer includes a data acquisition card, a PC and data processing programs. The thick dentin and enamel layers and the small amount of blood in a tooth are major problems for optical measurement of its vitality, and scattered light from the enamel and the dentin surrounding the pulpa also causes a problem in measurements based on reflectance. These problems are assessed here by means of theoretical models and calculations. The advantage of reflectance measurement is that only one probe is used, which is easy to put against the tooth. Thus measurements are simple to make. Three wavelengths (560 nm, 650 nm, 850 nm) are used to measure photoplethysmographic signals, and these should allow the oxygen saturation of the blood in a tooth to be measured as well in the future. Series of measurements have been performed on vital and non-vital teeth by recording photoplethysmographic signals, using the vitalometer and using a commercial laser-Doppler instrument. Verifications of the laser-Doppler and vitalometer results are presented and deduced here.

  14. Multi-wavelength studies of Redback and Black Widow pulsars

    Science.gov (United States)

    Mignani, Roberto; Salvetti, David; Pallanca, Cristina; Marelli, Martino; De Luca, Andrea; Belfiore, Andrea Mario

    2016-07-01

    The unexpected Fermi discovery of more than 70 gamma-ray milli-second pulsars (MSPs) outside globular clusters, spurred the scientific interest on these objects, and opened new horizons in MSP astronomy and on the study of the evolution of neutron stars in compact binary systems, including the ablation process of the companion star in the so-called Black Widow (BW) and Redback (RB) systems. It is thought that an important fraction of the tens of unidentified pulsar-like Fermi sources at high latitude are MSPs, yet unidentified, owing to their extremely elusive radio emission. As shown in a few recent cases, optical observations have been instrumental to spot binary MSP candidates through the discovery of periodic modulations in the flux of their putative companions. In this contribution, we report on the recent follow-ups of several candidate binary MSPs carried out with optical and X-ray facilities, e.g. GROND and XMM-Newton, Swift. This program already lead to identification of the Fermi source 3FGL 2036.6-5618 as candidate RB system, through the detection of periodic (orbital) modulation of its X/optical flux (Salvetti et al. 2015).

  15. Continuous vertical aerosol profiling with a multi-wavelength Raman polarization lidar over the Pearl River Delta, China

    Science.gov (United States)

    Heese, Birgit; Baars, Holger; Bohlmann, Stephanie; Althausen, Dietrich; Deng, Ruru

    2017-06-01

    A dataset of particle optical properties of the highly polluted atmosphere over the Pearl River Delta (PRD), Guangzhou, China, is presented in this paper. The data were derived from the measurements of a multi-wavelength Raman and depolarization lidar PollyXT and a co-located AERONET sun photometer. The measurement campaign was conducted from November 2011 to mid-June 2012. These are the first Raman lidar measurements in the PRD that lasted for several months. A mean value of aerosol optical depth (AOD) of 0.54 ± 0.33 was observed by the sun photometer at 500 nm in the polluted atmosphere over this megacity for the whole measurement period. The lidar profiles frequently show lofted aerosol layers, which reach altitudes of up to 2 to 3 km and, especially during the spring season, up to 5 km. These layers contain between 12 and 56 % of the total AOD, with the highest values in spring. The aerosol types in these lofted layers are classified by their optical properties. The observed lidar ratio values range from 30 to 80 sr with a mean value of 48.0 ± 10.7 sr at 532 nm. The linear particle depolarization ratio at 532 nm lies mostly below 5 %, with a mean value of 3.6 ± 3.7 %. The majority of the Ångström exponents lie between 0.5 and 1.5, indicating a mixture of fine- and coarse-mode aerosols. These results reveal that mostly urban pollution particles mixed with particles produced from biomass and industrial burning are present in the atmosphere above the Pearl River Delta. Trajectory analyses show that these pollution mixtures arise mainly from local and regional sources.

  16. Multiwavelength detectability of Pop III GRBs from afterglow simulations

    Science.gov (United States)

    Macpherson, D.; Coward, D.

    2017-05-01

    Afterglows of gamma-ray bursts (GRBs) from Population III (Pop III) stars could reveal the formation history and properties of these first generation stars. Through detailed simulation, we predict the prospects of detecting these afterglows with a range of established, existing and upcoming telescopes across the spectrum from radio waves to X-rays. The simulations show that the afterglow light curves of Pop III GRBs at high redshift (≳8) are very similar to those of Pop I/II GRBs at lower redshift (˜2), with the distinction that Lyα absorption at Pop III redshifts removes any optical [and some near-infrared (NIR)] component. We calculate that within a single field of view (FOV) of the Australian Square Kilometre Array Pathfinder (ASKAP) telescope there will be on average four detectable Pop III GRB afterglows. This is the product of ASKAP's large FOV and excellent sensitivity at wavelengths where the afterglows are very long-lasting. We show that the exceptional sensitivity of the James Webb Space Telescope (JWST) Near-InfraRed Camera will make this the optimal instrument for afterglow follow-up and redshift measurement, while JWST Near-InfraRed Spectrograph will be able to detect the absorption features of Pop III-enriched environments in 70 per cent of directed Pop III GRB afterglows. We also find that the Atacama Large Millimetre Array is very poorly suited to observe these afterglows, and that the Spectrum-Roentgen-Gamma 4 yr all-sky X-ray survey has a 12 per cent chance of detecting an orphan Pop III GRB afterglow. The optimal strategy for detecting, identifying and studying Pop III GRB afterglows is to have JWST attempt NIR photometry of afterglows with a detected radio component but no detected optical component.

  17. MODELING MULTI-WAVELENGTH PULSE PROFILES OF THE MILLISECOND PULSAR PSR B1821–24

    Energy Technology Data Exchange (ETDEWEB)

    Du, Yuanjie; Shuai, Ping; Bei, Xiaomin; Chen, Shaolong; Fu, Linzhong; Huang, Liangwei; Lin, Qingqing; Meng, Jing; Wu, Yaojun; Zhang, Hengbin; Zhang, Qian; Zhang, Xinyuan [Qian Xuesen Laboratory of Space Technology, NO. 104, Youyi Road, Haidian District, Beijing 100094 (China); Qiao, Guojun, E-mail: dyj@nao.cas.cn [School of Physics, Peking University, Beijing 100871 (China)

    2015-03-10

    PSR B1821–24 is a solitary millisecond pulsar that radiates multi-wavelength pulsed photons. It has complex radio, X-ray, and γ-ray pulse profiles with distinct peak phase separations that challenge the traditional caustic emission models. Using the single-pole annular gap model with a suitable magnetic inclination angle (α = 40°) and viewing angle (ζ = 75°), we managed to reproduce its pulse profiles of three wavebands. It is found that the middle radio peak originated from the core gap region at high altitudes, and the other two radio peaks originated from the annular gap region at relatively low altitudes. Two peaks of both X-ray and γ-ray wavebands basically originated from the annular gap region, while the γ-ray emission generated from the core gap region contributes somewhat to the first γ-ray peak. Precisely reproducing the multi-wavelength pulse profiles of PSR B1821–24 enables us to understand emission regions of distinct wavebands and justify pulsar emission models.

  18. Compact and autonomous multiwavelength microanalyzer for in-line and in situ colorimetric determinations.

    Science.gov (United States)

    da Rocha, Zaira M; Martinez-Cisneros, Cynthia S; Seabra, Antonio C; Valdés, Francisco; Gongora-Rubio, Mario R; Alonso-Chamarro, Julian

    2012-01-07

    Nowadays, the attainment of microsystems that integrate most of the stages involved in an analytical process has raised an enormous interest in several research fields. This approach provides experimental set-ups of increased robustness and reliability, which simplify their application to in-line and continuous biomedical and environmental monitoring. In this work, a novel, compact and autonomous microanalyzer aimed at multiwavelength colorimetric determinations is presented. It integrates the microfluidics (a three-dimensional mixer and a 25 mm length "Z-shape" optical flow-cell), a highly versatile multiwavelength optical detection system and the associated electronics for signal processing and drive, all in the same device. The flexibility provided by its design allows the microanalyzer to be operated either in single fixed mode to provide a dedicated photometer or in multiple wavelength mode to obtain discrete pseudospectra. To increase its reliability, automate its operation and allow it to work under unattended conditions, a multicommutation sub-system was developed and integrated with the experimental set-up. The device was initially evaluated in the absence of chemical reactions using four acidochromic dyes and later applied to determine some key environmental parameters such as phenol index, chromium(VI) and nitrite ions. Results were comparable with those obtained with commercial instrumentation and allowed to demonstrate the versatility of the proposed microanalyzer as an autonomous and portable device able to be applied to other analytical methodologies based on colorimetric determinations.

  19. Reagentless Bacterial Identification Using a Combination of Multiwavelength Transmission and Angular Scattering Spectroscopy

    Directory of Open Access Journals (Sweden)

    Debra E. Huffman

    2016-01-01

    Full Text Available Optics based technologies are being advanced by many diagnostic companies around the globe. This resurgence is being driven by several factors including novel materials, enhanced computer power, nonlinear optics, and advances in algorithmic and statistical analysis. This study expands on a previous paper that evaluated the capability of a reagent-free optical profiling platform technology that used multiwavelength transmission spectroscopy to identify bacterial pathogens from pure culture. This study combines multiwavelength angular scattering with transmission based analysis into a single algorithm that will identify bacterial pathogens. Six predominant organisms, S. aureus, E. coli, K. pneumoniae and P. aeruginosa, E. faecalis, and coagulase negative Staphylococcus, were analyzed from a total of 753 clinical isolates received from three large community hospital systems. The bacterial identification method used for comparison in this study was the Vitek-2 (bioMerieux which utilizes a biochemically based identification system. All of the clinical isolates received were blinded as to their identification until completion of the optical analysis. Sensitivities ranged from 87.7 to 94.6% with specificities ranging from 97.2 to 99.9% indicating that optical profiling is a powerful and exciting new technology that could be developed for the rapid identification of pathogens without the use of chemical reagents.

  20. Multiwavelength variability study and search for periodicity of PKS 1510-089

    Science.gov (United States)

    Castignani, G.; Pian, E.; Belloni, T. M.; D'Ammando, F.; Foschini, L.; Ghisellini, G.; Pursimo, T.; Bazzano, A.; Beckmann, V.; Bianchin, V.; Fiocchi, M. T.; Impiombato, D.; Raiteri, C. M.; Soldi, S.; Tagliaferri, G.; Treves, A.; Türler, M.

    2017-05-01

    Context. Blazars are the most luminous and variable active galactic nuclei (AGNs). They are thus excellent probes of accretion and emission processes close to the central engine. Aims: We concentrate here on PKS 1510-089 (z = 0.36), a blazar belonging to the flat-spectrum radio quasar subclass, an extremely powerful gamma-ray source and one of the brightest in the Fermi-LAT catalog. We aim to study the complex variability of this blazar's bright multiwavelength spectrum, to identify the physical parameters responsible for the variations and the timescales of possible recurrence and quasi-periodicity at high energies. Methods: The blazar PKS 1510-089 was observed twice in hard X-rays with the IBIS instrument onboard INTEGRAL during the flares of Jan. 2009 and Jan. 2010, and simultaneously with Swift and the Nordic Optical Telescope (NOT), in addition to the constant Fermi monitoring. We also measured the optical polarization in several bands on 18 Jan. 2010 at the NOT.Using these and archival data we constructed historical light curves at gamma-to-radio wavelengths covering nearly 20 yr and applied tests of fractional and correlated variability. We assembled spectral energy distributions (SEDs) based on these data and compared them with those at two previous epochs, by applying a model based on synchrotron and inverse Compton radiation from blazars. Results: The modeling of the SEDs suggests that the physical quantities that undergo the largest variations are the total power injected into the emitting region and the random Lorentz factor of the electron distribution cooling break, that are higher in the higher gamma-ray states. This suggests a correlation of the injected power with enhanced activity of the acceleration mechanism. The cooling likely takes place at a distance of 1000 Schwarzschild radii( 0.03 pc) from the central engine - a distance muchsmaller than the broad line region (BLR) radius.The emission at a few hundred GeV can be reproduced with inverse

  1. First-Light Galaxies or Intrahalo Stars: Multi-Wavelength Measurements of the Infrared Background Anisotropies

    Science.gov (United States)

    Cooray, Asantha

    The research program described in this proposal can be broadly described as data analysis, measurement, and interpretation of the spatial fluctuations of the unresolved cosmic IR background. We will focus primarily on the background at optical and near-IR wavelengths as probed by Hubble and Spitzer. As absolute background intensity measurements are challenging, the focus is on the spatial fluctuations similar to the anisotropiesof the cosmic microwave background (CMB). Measurements of the unresolved Spitzer fluctuations by two independent teams on multiple fields agree within the measurement errors. However, there are now two interpretations on the origin of the unresolved IRAC fluctuations. One involves a population of faint sources at very high redshifts (z > 6) during the epoch of reionization. The second interpretation involves the integrated emission from intrahalo light associated with diffuse stars in the outskirts of z of 1 to 3 dark matter halos of galaxies. We now propose to further test these two interpretations with a new set of measurements at shorter IR and optical wavelengths with HST/ACS and WFC3 overlapping with deep IRAC surveys. A multi-wavelength study from 0.5 to 4.5 micron will allow us to independently determine the relative contribution of intrahalo light and z > 8 faint galaxies to the unresolved IR fluctuations. We will also place strong limits on the surface density of faint sources at z > 8. Such a limit will be useful for planning deep surveys with JWST. Moving to the recent wide IRAC fields with the warm mission, we propose to study fluctuations at tens of degree angular scales. At such large angular scales IRAC fluctuations should trace diffuse Galactic light (DGL), ISM dust-scattered starlight in our Galaxy. We will measure the amplitude and slope of the DGL power spectrum and compare them to measurements of the Galactic dust power spectrum from IRAS and Planck and study if the large degree-scale fluctuations seen in CIBER can be

  2. X-shooter, NACO, and AMBER observations of the LBV Pistol Star

    NARCIS (Netherlands)

    Martayan, C.; Blomme, R.; Bouquin, J.-B; Merand, A.; Montagnier, G.; Selman, F.; Girard, J.; Fox, A.; Baade, D.; Frémat, Y.; Lobel, A.; Martins, F.; Patru, F.; Rivinius, T.; Sana, H.A.A.; Stefl, S.; Zorec, J.; Semaan, T.

    2011-01-01

    We present multi-instrument and multi-wavelength observations of the famous LBV star Pistol Star. These observations are part of a larger program on early O stars at different metallicities. The Pistol Star has been claimed to be one of the most massive star known, with 250 solar masses. We present

  3. A Multiwavelength Study of the Segue 3 Cluster

    Science.gov (United States)

    Hughes, Joanne; Lacy, Brianna; Sakari, Charli; Wallerstein, George; Davis, Christoper Evan; Schiefelbein, Spencer; Corrin, Olivia; Joudi, Hanah; Le, Donna; Haynes, Rose Marie

    2017-08-01

    We present new SDSS and Washington photometry of the young outer-halo stellar system Segue 3. Combined with archival VI-observations, our most consistent results yield Z=0.006+/- 0.001, {log}({Age})=9.42+/- 0.08, {(m-M)}0=17.35+/- 0.08, and E(B-V)=0.09+/- 0.01, with a high binary fraction of 0.39 ± 0.05 derived using the Padova models. We confirm that mass-segregation has occurred, supporting the hypothesis that this cluster is being tidally disrupted. A three-parameter King model yields a cluster radius of {r}{cl}=0\\mathop{.}\\limits^\\circ 017+/- 0\\mathop{.}\\limits^\\circ 007, a core radius of {r}{{c}}=0\\mathop{.}\\limits^\\circ 003+/- 0\\mathop{.}\\limits^\\circ 001, and a tidal radius of {r}{{t}}=0\\mathop{.}\\limits^\\circ 04+/- 0\\mathop{.}\\limits^\\circ 02. A comparison of Padova and Dartmouth model-grids indicates that the cluster is not significantly α-enhanced, with a mean [{Fe}/{{H}}]=-{0.55}-0.12+0.15 dex, and a population age of only 2.6 ± 0.4 Gyr. We rule out a statistically significant age spread at the main-sequence turnoff because of a narrow subgiant branch, and discuss the role of stellar rotation and cluster age, using Dartmouth and Geneva models: approximately 70% of the Seg 3 stars at or below the main-sequence turnoff have enhanced rotation. Our results for Segue 3 indicate that it is younger and more metal-rich than all previous studies have reported to date. From colors involving Washington C and SDSS-u filters, we identify several giants and a possible blue straggler for future follow-up spectroscopic studies, and we produce spectral energy distributions of previously known members and potential Segue 3 sources with Washington (CT 1), Sloan (ugri), and VI-filters. Segue 3 shares the characteristics of unusual stellar systems that have likely been stripped from external dwarf galaxies as they are being accreted by the Milky Way, or that have been formed during such an event. Its youth, metallicity, and location are all inconsistent

  4. Modeling Brain Circuitry over a Wide Range of Scales

    Directory of Open Access Journals (Sweden)

    Pascal eFua

    2015-04-01

    Full Text Available If we are ever to unravel the mysteries of brain function at its most fundamental level, we will need a precise understanding of how its component neurons connect to each other. Electron Microscopes (EM can now provide the nanometer resolution that is needed to image synapses, and therefore connections, while Light Microscopes (LM see at the micrometer resolution required to model the 3D structure of the dendritic network. Since both the topology and the connection strength are integral parts of the brain's wiring diagram, being able to combine these two modalities is critically important.In fact, these microscopes now routinely produce high-resolution imagery in such large quantities that the bottleneck becomes automated processing and interpretation, which is needed for such data to be exploited to its full potential. In this paper, we briefly review the Computer Vision techniques we have developed at EPFL to address this need. They include delineating dendritic arbors from LM imagery, segmenting organelles from EM, and combining the two into a consistent representation.

  5. Wide-ranging Online Data for Epidemiologic Research (WONDER)

    Data.gov (United States)

    U.S. Department of Health & Human Services — WONDER online databases include county-level Compressed Mortality (death certificates) since 1979; county-level Multiple Cause of Death (death certificates) since...

  6. MGP : a tool for wide range temperature modelling

    Energy Technology Data Exchange (ETDEWEB)

    Morales, A.F. [Inst. Tecnologico Autonomo de Mexico, Mexico City (Mexico); Seisdedos, L.V. [Univ. de Oriente, Santiago de Cuba (Cuba). Dept. de Control Automatico

    2006-07-01

    This paper proposed a practical temperature modelling tool that used genetic multivariate polynomials to determine polynomial expressions of enthalpy and empirical heat transfer equations in superheaters. The model was designed to transform static parameter estimations from distributed into lumped parameter systems. Two dynamic regimes were explored: (1) a power dynamics regime containing major inputs and outputs needed for overall plant control; and (2) a steam temperature dynamics scheme that considered consecutive superheater sections considered in terms of cooling water mass flow and steam mass flow. The single lumped parameters model was developed to provide temperature control for a fossil fuel-fired power plant. The design procedure used enthalpy to determine the plant's energy balance. The enthalpy curve was seen as a function of either temperature and steam pressure. A graphic simulation tool was used to optimize the model by comparing real and simulated plant data. The study showed that the amount of energy taken by the steam mass flow per time unit can be calculated by measuring temperatures and pressures at both ends of the superheater. An algorithm was then developed to determine the polynomial's coefficients according to best curve fitting over the training set and best maximum errors. It was concluded that a unified approach is now being developed to simulate and emulate the dynamics of steam temperature for each section's attemporator-superheater. 14 refs., 3 tabs., 5 figs.

  7. Musa germplasm diversity status across a wide range of agro ...

    African Journals Online (AJOL)

    SARAH

    2014-01-31

    Jan 31, 2014 ... programme leading to loss of archived information and a complete staff .... index of diversity 1–D was used as the measure of ..... Progress Report 5. pp. 8-9. Colwell RK, 2009. Biodiversity: concepts, patterns, and measurement. Levin SA, Carpenter SR,. Godfray HCJ, Kinzig AP, Loreau M, Losos JB,.

  8. Capacitive MEMS accelerometer wide range modeling using artificial neural network

    OpenAIRE

    A. Baharodimehr; A. Abolfazl Suratgar; H. Sadeghi

    2009-01-01

    This paper presents a nonlinear model for a capacitive microelectromechanical accelerometer (MEMA). System parameters ofthe accelerometer are developed using the effect of cubic term of the folded‐flexure spring. To solve this equation, we use theFEA method. The neural network (NN) uses the Levenberg‐Marquardt (LM) method for training the system to have a moreaccurate response. The designed NN can identify and predict the displacement of the movable mass of accelerometer. Thesimulation result...

  9. Capacitive MEMS accelerometer wide range modeling using artificial neural network

    Directory of Open Access Journals (Sweden)

    A. Baharodimehr

    2009-08-01

    Full Text Available This paper presents a nonlinear model for a capacitive microelectromechanical accelerometer (MEMA. System parameters ofthe accelerometer are developed using the effect of cubic term of the folded‐flexure spring. To solve this equation, we use theFEA method. The neural network (NN uses the Levenberg‐Marquardt (LM method for training the system to have a moreaccurate response. The designed NN can identify and predict the displacement of the movable mass of accelerometer. Thesimulation results are very promising.

  10. Musa germplasm diversity status across a wide range of agro ...

    African Journals Online (AJOL)

    SARAH

    org on 31st January 2014. .... data in this study. Across all sites, 118 farmers were sampled along the transect using a random systematic method. Sampling was done on farms that had at least ..... marketing in Rwanda, Burundi and South. Kivu.

  11. A Wide Range Temperature Sensor Using SOI Technology

    Science.gov (United States)

    Patterson, Richard L.; Elbuluk, Malik E.; Hammoud, Ahmad

    2009-01-01

    Silicon-on-insulator (SOI) technology is becoming widely used in integrated circuit chips for its advantages over the conventional silicon counterpart. The decrease in leakage current combined with lower power consumption allows electronics to operate in a broader temperature range. This paper describes the performance of an SOIbased temperature sensor under extreme temperatures and thermal cycling. The sensor comprised of a temperature-to-frequency relaxation oscillator circuit utilizing an SOI precision timer chip. The circuit was evaluated under extreme temperature exposure and thermal cycling between -190 C and +210 C. The results indicate that the sensor performed well over the entire test temperature range and it was able to re-start at extreme temperatures.

  12. Wide range pressure sensor based on a piezoelectric bimorph microcantilever

    Science.gov (United States)

    Mortet, V.; Petersen, R.; Haenen, K.; D'Olieslaeger, M.

    2006-03-01

    Since the development of the atomic force microscope, interest in microfabricated cantilevers has grown. Cantilevers are excellent micromechanical sensors. In this work, we use a commercially available piezoelectric bimorph cantilever as pressure and temperature sensor. The piezoelectric layer acts as both sensor and actuator. The sensor detects the change in the resonance frequencies due to the drag force of the surrounding gas. The frequency shift of the resonant modes is measured as a function of the pressure and the temperature. The results show that both pressure and temperature can be measured simultaneously using the piezoelectric bimorph cantilever's resonant frequencies.

  13. Wide range pressure sensor based on a piezoelectric bimorph microcantilever

    OpenAIRE

    MORTET, Vincent; PETERSEN, Rainer; HAENEN, Ken; D'OLIESLAEGER, Marc

    2006-01-01

    Since the development of the atomic force microscope, interest in microfabricated cantilevers has grown. Cantilevers are excellent micromechanical sensors. In this work, we use a commercially available piezoelectric bimorph cantilever as pressure and temperature sensor. The piezoelectric layer acts as both sensor and actuator. The sensor detects the change in the resonance frequencies due to the drag force of the surrounding gas. The frequency shift of the resonant modes is measured as a func...

  14. Musa germplasm diversity status across a wide range of agro ...

    African Journals Online (AJOL)

    Cooking cultivars only dominate in the district of Kirehe, while beer cultivars dominate the banana production landscape in the other districts. Taste/flavor, bunch size and market demand were the most important criteria for banana cultivar selection and thus greatly influenced cultivar conservation and distribution on-farm.

  15. Carbonaceous Meteorites Contain a Wide Range of Extraterrestrial Nucleobases

    Science.gov (United States)

    Callahan, Michael P.; Smith, Karen E.; Cleaves, H. James, II; Ruzicka, Josef; Stern, Jennifer C.; Glavin, Daniel P.; House, Christopher H.; Dworkin, Jason P.

    2011-01-01

    All terrestrial organisms depend on nucleic acids (RNA and DNA), which use pyrimidine and purine nucleobases to encode genetic information. Carbon-rich meteorites may have been important sources of organic compounds required for the emergence of life on the early Earth; however, the origin and formation of nuc1eobases in meteorites has been debated for over 50 y. So far, the few nuc1eobases reported in meteorites are biologically common and lacked the structural diversity typical of other indigenous meteoritic organics. Here, we investigated the abundance and distribution of nucleobases and nucleobase analogs in formic acid extracts of 12 different meteorites by liquid chromatography-mass spectrometry. The Murchison and Lonewolf Nunataks 94102 meteorites contained a diverse suite of nucleobases, which included three unusual and terrestrially rare nucleobase analogs; purine, 2,6-diminopurine, and 6,8-diaminopurine. In a parallel experiment, we found an identical suite of nucleobases and nucleobase analogs generated in reactions of ammonium cyanide. Additionally, these nucleobase analoge were not detected above our parts-per-billion detection limits in any of the procedural blanks, control samples, a terrestrial soil sample, and an Antarctic ice sample. Our results demonstrate that the purines detected in meteorites are consistent with products of ammonium cyanide chemistry, which provides a plausible mechanism for their synthesis in the asteroid parent bodies, and strongly supports an extraterrestrial origin. The discovery of new nucleobase analogs in meteorites also expands the prebiotic molecular inventory available for constructing the first genetic molecules.

  16. Autonomous Vehicles Have a Wide Range of Possible Energy Impacts

    Energy Technology Data Exchange (ETDEWEB)

    Austin Brown, Brittany Repac, Jeff Gonder

    2013-07-15

    Self-driving or “autonomous” vehicles (AVs) have leapt from science fiction into the forefront of transportation technology news. The technology is likely still years away from widespread commercial adoption, but the recent progress makes it worth considering the potential national impacts of widespread implementation. This poster makes an initial assessment of the energy impacts of AV adoptionon a per-vehicle basis and on total personal vehicle fuel use. While AVs offer numerous potential advantages in energy use, there are significant factors that could decrease or even eliminate the energy benefits under some circumstances. This analysis attempts to describe, quantify, and combine many of the possible effects. The nature and magnitude of these effects remain highly uncertain. This set of effects is very unlikely to be exhaustive, but this analysis approach can serve as a base for future estimates.

  17. America: History and Life--A Wide Ranging Database.

    Science.gov (United States)

    Sweetland, James H.

    1983-01-01

    Description of America: History and Life (AHL)--database including references from over 2,000 periodicals in literature, philosophy, religion, art, sociology, other disciplines of historical value--highlights structure; document treatment; access points; comparison of dissertation coverage between AHL and Comprehensive Dissertation Abstracts;…

  18. The SCUBA-2 Cosmology Legacy Survey: Multi-wavelength Properties of ALMA-identified Submillimeter Galaxies in UKIDSS UDS

    NARCIS (Netherlands)

    Simpson, J. M.; Smail, Ian; Swinbank, A. M.; Ivison, R. J.; Dunlop, J. S.; Geach, J. E.; Almaini, O.; Arumugam, V.; Bremer, M. N.; Chen, Chian-Chou; Conselice, C.; Coppin, K. E. K.; Farrah, D.; Ibar, E.; Hartley, W. G.; Ma, C. J.; Michałowski, M. J.; Scott, D.; Spaans, M.; Thomson, A. P.; van der Werf, P. P.

    2017-01-01

    We present a multi-wavelength analysis of 52 submillimeter galaxies (SMGs), identified using ALMA 870 μm continuum imaging in a pilot program to precisely locate bright SCUBA-2-selected submillimeter sources in the UKIDSS Ultra Deep Survey (UDS) field. Using the available deep (especially

  19. A MULTI-WAVELENGTH POLARIMETRIC STUDY OF THE BLAZAR CTA 102 DURING A GAMMA-RAY FLARE IN 2012

    Energy Technology Data Exchange (ETDEWEB)

    Casadio, Carolina; Gómez, José L.; Agudo, Iván; Molina, Sol N. [Instituto de Astrofísica de Andalucía, CSIC, Apartado 3004, E-18080 Granada (Spain); Jorstad, Svetlana G.; Marscher, Alan P.; Bala, Vishal; Joshi, Manasvita; Taylor, Brian; Williamson, Karen E. [Institute for Astrophysical Research, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States); Larionov, Valeri M.; Blinov, Dmitry A.; Grishina, Tatiana S.; Hagen-Thorn, Vladimir A. [Astronomical Institute, St. Petersburg State University, Universitetskij Pr. 28, Petrodvorets, 198504 St. Petersburg (Russian Federation); Smith, Paul S. [Steward Observatory, University of Arizona, Tucson, AZ 85716 (United States); Gurwell, Mark A. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Lähteenmäki, Anne [Aalto University Metsähovi Radio Observatory, Metsähovintie 114, FI-02540 Kylmälä (Finland); Arkharov, Arkady A. [Pulkovo Observatory, St. Petersburg (Russian Federation); Borman, George A. [Crimean Astrophysical Observatory, Nauchnij (Ukraine); Paola, Andrea Di [INAF, Osservatorio Astronomico di Roma, Roma (Italy); and others

    2015-11-01

    We perform a multi-wavelength polarimetric study of the quasar CTA 102 during an extraordinarily bright γ-ray outburst detected by the Fermi Large Area Telescope in 2012 September–October when the source reached a flux of F{sub >100} {sub MeV} = 5.2 ± 0.4 × 10{sup −6} photons cm{sup −2} s{sup −1}. At the same time, the source displayed an unprecedented optical and near-infrared (near-IR) outburst. We study the evolution of the parsec-scale jet with ultra-high angular resolution through a sequence of 80 total and polarized intensity Very Long Baseline Array images at 43 GHz, covering the observing period from 2007 June to 2014 June. We find that the γ-ray outburst is coincident with flares at all the other frequencies and is related to the passage of a new superluminal knot through the radio core. The powerful γ-ray emission is associated with a change in direction of the jet, which became oriented more closely to our line of sight (θ ∼ 1.°2) during the ejection of the knot and the γ-ray outburst. During the flare, the optical polarized emission displays intra-day variability and a clear clockwise rotation of electric vector position angles (EVPAs), which we associate with the path followed by the knot as it moves along helical magnetic field lines, although a random walk of the EVPA caused by a turbulent magnetic field cannot be ruled out. We locate the γ-ray outburst a short distance downstream of the radio core, parsecs from the black hole. This suggests that synchrotron self-Compton scattering of NIR to ultraviolet photons is the probable mechanism for the γ-ray production.

  20. Multiwavelength shearography for quantitative measurements of two-dimensional strain distributions.

    Science.gov (United States)

    Kästle, R; Hack, E; Sennhauser, U

    1999-01-01

    We report on the development of a multiwavelength speckle pattern shearing interferometer for the determination of two-dimensional strain distributions. This system is based on simultaneous illumination of the object with three diode lasers that emit at different wavelengths between 800 and 850 nm. Wavelength separation and image acquisition were performed with a special optical arrangement, including narrow-bandpass filters and three black-and-white cameras. The shearographic camera with a variable shearing element, in combination with the appropriate illumination geometry, permitted us to isolate all six displacement derivatives from phase-stepped fringe patterns. The optical system and the measurement procedure were validated with two different experiments. First, the shearographic sensor head was used for the determination of in-plane displacements, and, second, in-plane strain distributions of an aluminum block caused by temperature expansion were measured.

  1. Efficient and Accurate Modeling of Multiwavelength Propagation in SOAs: A Generalized Coupled-Mode Approach

    Science.gov (United States)

    Antonelli, Cristian; Mecozzi, Antonio; Li, Wangzhe; Coldren, Larry A.

    2016-05-01

    We present a model for multi-wavelength mixing in semiconductor optical amplifiers (SOAs) based on coupled-mode equations. The proposed model applies to all kinds of SOA structures, takes into account the longitudinal dependence of carrier density caused by saturation, it accommodates an arbitrary functional dependencies of the material gain and carrier recombination rate on the local value of carrier density, and is computationally more efficient by orders of magnitude as compared with the standard full model based on space-time equations. We apply the coupled-mode equations model to a recently demonstrated phase-sensitive amplifier based on an integrated SOA and prove its results to be consistent with the experimental data. The accuracy of the proposed model is certified by means of a meticulous comparison with the results obtained by integrating the space-time equations.

  2. Measurements of aerosol and cloud layers using a multi-wavelength Elastic-Raman lidar

    Science.gov (United States)

    Arapi, A.

    2016-12-01

    Aerosols and clouds play an important role in air-quality, weather and climate relevant studies. The discrimination of aerosol and cloud and their subtype classification are critical in the remote sensing measurements from ground and space. In this presentation, we first present the visual measurements of aloft aerosol and cloud layers from a multi-wavelength Elastic-Raman lidar this summer in New York City. Then, we implement an algorithm and Matlab codes for discriminating aerosol and cloud based on spectral dependence or attenuated color-ratio of aerosols and clouds. The color-ratios at the three-wavelength pairs and the different thresholds are examined for improving the detection sensitivity or capability. Furthermore, a wavelet-analysis technique with different scales parameter is refined to estimate the heights of aerosol and clouds. Finally, a few cases studies are shown for the algorithm evaluation.

  3. Multi-Wavelength Intra-Day Variability and Quasi-Periodic Oscillation in Blazars

    Science.gov (United States)

    Gupta, Alok

    2018-01-01

    We reviewed multi-wavelength blazars variability and detection of quasi-periodic oscillations on intra-day timescales. The variability timescale from few minutes to up to less than a days is commonly known as intra-day variability. These fast variations are extremely useful to constrain the size of emitting region, black hole mass estimation, etc. It is noticed that in general blazars show intra-day variability in the complete electromagnetic spectrum. But some class of blazars either do not show or show very little intra-day variability in a specific band of electromagnetic spectrum. Blazars show rarely quasi-periodic oscillations in time series data in optical and X-ray bands. Other properties and emission mechanism of blazars are also briefly discussed.

  4. Multi-wavelength mid-infrared plasmonic antennas with single nanoscale focal point.

    Science.gov (United States)

    Blanchard, Romain; Boriskina, Svetlana V; Genevet, Patrice; Kats, Mikhail A; Tetienne, Jean-Philippe; Yu, Nanfang; Scully, Marlan O; Dal Negro, Luca; Capasso, Federico

    2011-10-24

    We propose and demonstrate a novel photonic-plasmonic antenna capable of confining electromagnetic radiation at several mid-infrared wavelengths to a single sub-wavelength spot. The structure relies on the coupling between the localized surface plasmon resonance of a bow-tie nanoantenna with the photonic modes of surrounding multi-periodic particle arrays. Far-field measurements of the transmission through the central bow-tie demonstrate the presence of Fano-like interference effects resulting from the interaction of the bow-tie antenna with the surrounding nanoparticle arrays. The near-field of the multi-wavelength antenna is imaged using an aperture-less near-field scanning optical microscope. This antenna is relevant for the development of near-field probes for nanoimaging, spectroscopy and biosensing. © 2011 Optical Society of America

  5. Multi-wavelength imaging with the adaptive optics scanning laser Ophthalmoscope

    Science.gov (United States)

    Grieve, Kate; Tiruveedhula, Pavan; Zhang, Yuhua; Roorda, Austin

    2006-12-01

    The adaptive optics scanning laser ophthalmoscope has been fitted with three light sources of different wavelengths to allow simultaneous or separate imaging with one, two or three wavelength combinations. The source wavelengths used are 532 nm, 658 nm and 840 nm. Typically the instrument is used in dual-frame mode, performing imaging at 840 nm and precisely coincident retinal stimulation in one of the visible wavelengths. Instrument set-up and single-detector image capture are described. Simultaneous multi-wavelength imaging in the living human retina is demonstrated. The chromatic aberrations of the human eye lead to lateral and axial shifts, as well as magnification differences in the image, from one wavelength to another. Measurement of these chromatic effects is described for instrument characterization purposes.

  6. Application of multi-wavelength fluorometry for on-line monitoring of an anaerobic digestion process.

    Science.gov (United States)

    Morel, E; Santamaria, K; Perrier, M; Guiot, S R; Tartakovsky, B

    2004-01-01

    This work examined the use of multi-wavelength fluorometry for on-line monitoring of an anaerobic digestion process. Experiments were carried out in a laboratory-scale anaerobic digestor fed with either synthetic or agricultural (cheese factory) wastewater. An in-line fiber optic probe installed in the external recirculation loop of the reactor was used to acquire fluorescence spectra with an interval of 5-10 min. The spectra were compared with analytical measurements taken at the same time to develop regression models, which were then used to predict concentrations of chemical oxygen demand, volatile fatty acids, and other key process parameters. A comparison of partial least squares (PLS), nonlinear principal components regression, and step-wise regression models on an independent set of data showed that the PLS model gave the best prediction accuracy.

  7. Noctilucent cloud particle size determination based on multi-wavelength all-sky analysis

    Science.gov (United States)

    Ugolnikov, Oleg S.; Galkin, Alexey A.; Pilgaev, Sergey V.; Roldugin, Alexey V.

    2017-10-01

    The article deals with the analysis of color distribution in noctilucent clouds (NLC) in the sky based on multi-wavelength (RGB) CCD-photometry provided with the all-sky camera in Lovozero in the north of Russia (68.0°N, 35.1°E) during the bright expanded NLC performance in the night of August 12, 2016. Small changes in the NLC color across the sky are interpreted as the atmospheric absorption and extinction effects combined with the difference in the Mie scattering functions of NLC particles for the three color channels of the camera. The method described in this paper is used to find the effective monodisperse radius of particles about 55 nm. The result of these simple and cost-effective measurements is in good agreement with previous estimations of comparable accuracy. Non-spherical particles, Gaussian and lognormal distribution of the particle size are also considered.

  8. Noctilucent Cloud Particle Size Determination based on Multi-Wavelength All-Sky Analysis

    CERN Document Server

    Ugolnikov, Oleg S; Pilgaev, Sergey V; Roldugin, Alexey V

    2016-01-01

    The article deals with the analysis of color distribution in noctilucent clouds (NLC) in the sky based on multi-wavelength (RGB) CCD-photometry provided with the all-sky camera in Lovozero in the north of Russia (68.0 deg N, 35.1 deg E) during the bright expanded NLC performance in the night of August 12, 2016. Insignificant changes in the NLC color across the sky are interpreted as the atmospheric extinction effect combined with the difference in the Mie scattering functions of NLC particles for the three color channels of the camera. The method described in this paper is used to find the effective radius of particles about 56 nm. The result of these simple and cost-effective measurements is in good agreement with previous estimations of comparable accuracy. Non-spherical particles and lognormal distribution of the particle size are also considered.

  9. A 12 GHz wavelength spacing multi-wavelength laser source for wireless communication systems

    Science.gov (United States)

    Peng, P. C.; Shiu, R. K.; Bitew, M. A.; Chang, T. L.; Lai, C. H.; Junior, J. I.

    2017-08-01

    This paper presents a multi-wavelength laser source with 12 GHz wavelength spacing based on a single distributed feedback laser. A light wave generated from the distributed feedback laser is fed into a frequency shifter loop consisting of 50:50 coupler, dual-parallel Mach-Zehnder modulator, optical amplifier, optical filter, and polarization controller. The frequency of the input wavelength is shifted and then re-injected into the frequency shifter loop. By re-injecting the shifted wavelengths multiple times, we have generated 84 optical carriers with 12 GHz wavelength spacing and stable output power. For each channel, two wavelengths are modulated by a wireless data using the phase modulator and transmitted through a 25 km single mode fiber. In contrast to previously developed schemes, the proposed laser source does not incur DC bias drift problem. Moreover, it is a good candidate for radio-over-fiber systems to support multiple users using a single distributed feedback laser.

  10. Multiwavelength 25-GHz picosecond pulse generation with phase modulation and double-side Mamyshev reshaping.

    Science.gov (United States)

    Huo, Li; Li, Hongfeng; Wang, Dong; Wang, Qiang; Lou, Caiyun

    2015-06-20

    We demonstrate a simple, robust, and cost-effective method of generating high-speed multiwavelength picosecond optical pulses. This method is based on chirp compression of phase-modulated light, followed by nonlinear pulse compression and reshaping with a double-side Mamyshev reshaper. We show that this method becomes power efficient when the repetition rate is increased to 25 GHz. Wavelength-tunable optical pulses with a repetition rate of 25 GHz and pulse width of ∼2  ps, which can be temporally multiplexed to 100 GHz, are experimentally obtained over a large spectral range with moderate electrical and optical power. Simultaneous pulse generation on four wavelengths is demonstrated.

  11. Development of a Thermal/Optical Carbon Analyzer with Multi-Wavelength Capabilities

    Science.gov (United States)

    Sumlin, B.; Chow, J. C.; Watson, J. G.; Wang, X.; Gronstal, S.; Chen, L. W. A. A.; Trimble, D.

    2014-12-01

    A thermal/optical carbon analyzer (DRI Model 2015) equipped with a novel seven-wavelength light source (405, 445, 532, 635, 780, 808, and 980 nm) was developed to analyze chemical and optical properties of particles collected on quartz-fiber filters. Based on the DRI Model 2001 carbon analyzer at 633 nm, major modifications were made on mechanical and electrical components, flow control, and the carbon detector to adopt modern technologies, increase instrument reliability, and reduce costs and maintenance. The correlation between wavelength-dependent light attenuation and organic and elemental carbon (OC and EC, respectively) content allows estimation of the amount of brown and black carbon (BrC and BC, respectively) on filters. Continuous monitoring of the light reflected from and transmitted through the filter along with carbon evolved from the filter when heated to different temperatures under either inert or oxidizing gas environments provides insights into the optical properties of the carbon released from the filter; it also allows examination of the charring process as pyrolyzed char has been one of the major uncertainties in quantifying OC and EC. The objectives of this study are: 1) establish performance equivalency between the Model 2015 and Model 2001 DRI carbon analyzers when comparing similar laser wavelength to maintain consistency for long-term network sample analysis; and 2) analyze the multi-wavelength signal to quantify BrC and BC, and to optimize char correction. A selection of samples, including standard chemicals, rural and urban ambient filters, and emission sources from biomass burning, diesel and gasoline engine exhaust, and resuspended dust were measured by both the Model 2015 and Model 2001 analyzers. The instrument design, calibration, comparison with legacy analyzer, and interpretation of the multi-wavelengths measurement will be presented.

  12. Development, characterization, and application of the DRI model 2015 multiwavelength thermal-optical carbon analyzer

    Science.gov (United States)

    Sumlin, Benjamin J.

    A multiwavelength thermal/optical carbon analyzer (DRI Model 2015) equipped with a novel seven-wavelength light source (405, 445, 532, 635, 780, 808, and 980 nm) was developed to analyze chemical and optical properties of carbonaceous particles collected on quartz-fiber filters. Built upon on the DRI Model 2001 carbon analyzer at 633 nm, major modifications were made to mechanical and electrical components, flow control, and the carbon detector to adopt modern technologies, increase instrument reliability, and reduce costs and maintenance. This instrument quantifies organic and elemental carbon (OC and EC, respectively) and their thermal fractions. It also allows estimation of the amount of brown and black carbon (BrC and BC, respectively) on filters. Continuous monitoring of the light reflected from and transmitted through the filter along with carbon evolved from the filter when heated to different temperatures under either inert or oxidizing gas environments provides insights into the optical properties of the carbon released from the filter; it also allows examination of the charring process as pyrolyzed char has been one of the major uncertainties in quantifying OC and EC. The objectives of this study are: 1) characterize the Model 2015's performance parameters including detection limits, and optical behavior; 2) establish performance equivalence between the Model 2015 and Model 2001 DRI carbon analyzers when comparing similar laser wavelength to maintain consistency for long-term network sample analysis; and 3) conduct a preliminary analysis of the multiwavelength signal to estimate BrC and BC, and to optimize char correction. A selection of samples, including standard chemicals, as well as rural and urban ambient filter samples were measured by both the Model 2015 and Model 2001 analyzers. The design and construction experience will be discussed, as well as recommended future scientific research and engineering development.

  13. NuSTAR observations of heavily obscured quasars at z ~ 0.5

    DEFF Research Database (Denmark)

    Lansbury, G. B.; Alexander, D. M.; Del Moro, A.

    2014-01-01

    We present NuSTAR hard X-ray observations of three Type 2 quasars at z ≈ 0.4-0.5, optically selected from the Sloan Digital Sky Survey. Although the quasars show evidence for being heavily obscured, Compton-thick systems on the basis of the 2-10 keV to [O III] luminosity ratio and multiwavelength...

  14. FBQS J1644+2619: multiwavelength properties and its place in the class of γ-ray emitting Narrow Line Seyfert 1s★

    Science.gov (United States)

    Larsson, J.; D'Ammando, F.; Falocco, S.; Giroletti, M.; Orienti, M.; Piconcelli, E.; Righini, S.

    2018-01-01

    A small fraction of Narrow Line Seyfert 1s (NLSy1s) are observed to be γ-ray emitters. Understanding the properties of these sources is of interest since the majority of NLSy1s are very different from typical blazars. Here, we present a multi-frequency analysis of FBQS J1644+2619, one of the most recently discovered γ-ray emitting NLSy1s. We analyse an ˜80 ks XMM-Newton observation obtained in 2017, as well as quasi-simultaneous multi-wavelength observations covering the radio - γ-ray range. The spectral energy distribution of the source is similar to the other γ-ray NLSy1s, confirming its blazar-like nature. The X-ray spectrum is characterised by a hard photon index (Γ = 1.66) above 2 keV and a soft excess at lower energies.The hard photon index provides clear evidence that inverse Compton emission from the jet dominates the spectrum, while the soft excess can be explained by a contribution from the underlying Seyfert emission. This contribution can be fitted by reflection of emission from the base of the jet, as well as by Comptonisation in a warm, optically thick corona. We discuss our results in the context of the other γ-ray NLSy1s and note that the majority of them have similar X-ray spectra, with properties intermediate between blazars and radio-quiet NLSy1s.

  15. A multi-wavelength scattered light analysis of the dust grain population in the GG Tau circumbinary ring

    Energy Technology Data Exchange (ETDEWEB)

    Duchene, G; McCabe, C; Ghez, A; Macintosh, B

    2004-02-04

    We present the first 3.8 {micro}m image of the dusty ring surrounding the young binary system GG Tau, obtained with the W. M. Keck II 10m telescope's adaptive optics system. THis is the longest wavelength at which the ring has been detected in scattered light so far, allowing a multi-wavelength analysis of the scattering proiperties of the dust grains present in this protoplanetary disk in combination with previous, shorter wavelengths, HST images. We find that the scattering phase function of the dust grains in the disk is only weakly dependent on the wavelength. This is inconsistent with dust models inferred from observations of the interstellar medium or dense molecular clouds. In particular, the strongly forward-throwing scattering phase function observed at 3.8 {micro}m implies a significant increase in the population of large ({approx}> 1 {micro}m) grains, which provides direct evidence for grain growth in the ring. However, the grain size distribution required to match the 3.8 {micro}m image of the ring is incompatible with its published 1 {micro}m polarization map, implying that the dust population is not uniform throughout the ring. We also show that our 3.8 {micro}m image of the ring is incompatible with its published 1 {micro}m polarization map, implying that the dust population is not uniform throughout the ring. We also show that our 3.8 {micro}m scattered light image probes a deeper layer of the ring than previous shorter wavelength images, as demonstrated by a shift in the location of the inner edge of the disk's scattered light distribution between 1 and 3.8 {micro}m. We therefore propose a stratified structure for the ring in which the surface layers, located {approx} 50 AU above the ring midplane, contain dust grains that are very similar to those found in dense molecular clouds, while the region of the ring located {approx} 25 AU from the midplane contains significantly larger grains. This stratified structure is likely the result of

  16. INTERACT-II campaign:comparison of commercial lidars and ceilometers with advanced multi-wavelength Raman lidars

    Science.gov (United States)

    Rosoldi, Marco; Madonna, Fabio; Pappalardo, Gelsomina; Vande Hey, Joshua; Zheng, Yunhui; Vaisala Team

    2017-04-01

    Knowledge of aerosol spatio-temporal distribution in troposphere is essential for the study of climate and air quality. For this purpose, global scale high resolution continuous measurements of tropospheric aerosols are needed. Global coverage high resolution networks of ground-based low-cost and low-maintenance remote sensing instruments, such as commercial automatic lidars and ceilometers, can strongly contribute to this scientific mission. Therefore, it is very interesting for scientific community to understand to which extent these instruments are able to provide reliable aerosol measurements and fill in the geographical gaps of existing networks of the advanced lidars, like EARLINET (European Aerosol Research LIdar NETwork). The INTERACT-II (INTERcomparison of Aerosol and Cloud Tracking) campaign, carried out at CIAO (CNR-IMAA Atmospheric Observatory) in Tito Scalo, Potenza, Italy (760m a.s.l., 40.60°N, 15.72°E), aims to evaluate the performances of commercial automatic lidars and ceilometers for tropospheric aerosol profiling. The campaign has been performed in the period from July 2016 to January 2017 in the framework of ACTRIS-2 (Aerosol Clouds Trace gases Research InfraStructure) H2020 research infrastructure project. Besides the commercial ceilometers operational at CIAO (VAISALA CT25K and Luftt CHM15k), the performance of a CL51 VAISALA ceilometer, a Campbell CS135 ceilometer and a mini-Micro Pulse Lidar (MPL) have been assessed using the EARLINET multi-wavelengths Raman lidars operative at CIAO as reference. Following a similar approach used in the first INTERACT campaign (Madonna et al., AMT 2015), attenuated backscatter coefficient profiles and signals obtained from all the instruments have been compared, over a vertical resolution of 60 meters and a temporal integration ranging between 1 and 2 hours, depending on the observed atmospheric scenario. CIAO lidars signals have been processed using the EARLINET Single Calculus Chain (SCC) also with the

  17. A novel hybrid three-band transport system based on a DFB LD with multi-wavelength output characteristic

    Science.gov (United States)

    Lu, Hai-Han; Peng, Peng-Chun; Peng, Hsiang-Chun; Li, Chung-Yi; Su, Heng-Sheng

    2011-01-01

    A potentially cost-effective radio-over-fiber (ROF)/fiber-to-the-X (FTTX)/CATV hybrid three-band transport system based on direct modulation of a distributed feedback laser diode (DFB LD) with multi-wavelength output characteristic is proposed and experimentally demonstrated. Directly modulated radio-frequency (RF) (1.25Gbps/6GHz), externally remodulated baseband (BB) (622 Mbps), and externally remodulated CATV (channels 2-78) signals are successfully transmitted simultaneously. Over an 80-km single-mode fiber (SMF) transmission, low bit error rate (BER) and clear eye diagram were achieved for ROF and FTTX applications; and good performances of carrier-to-noise ratio (CNR), composite second-order (CSO) and composite triple beat (CTB) were obtained for CATV signals. Since our proposed systems use only a directly modulated DFB LD to achieve multi-wavelength transmission, it reveals an outstanding one with simpler and more economic advantages.

  18. Model based multi-wavelength spectrophotometric method for calculation of formation constants of phenanthrenequinone thiosemicarbazone complexes with some metallic cations

    Directory of Open Access Journals (Sweden)

    Naser Samadi

    2013-04-01

    Full Text Available In traditional spectrophotometric determination of stability constants of complexation, it is necessary to find a wavelength at which only one of the components has absorbance without any spectroscopic interference of the other reaction components. In the present work, a simple multi-wavelength model-based method has been developed to determine stability constants for complexation reaction regardless of the spectra overlapping of components. Also, pure spectra and concentration profiles of all components are extracted using multi-wavelength model based method. In the present work spectrophotometric titration of several cationic metal ions with new synthetic ligand were studied in order to calculate the formation constant(s. In order to estimate the formation constants a chemometrics method, model based analysis was applied.

  19. Performance enhancement of multi-wavelength generations based on SOAs with a microfiber Mach-Zehnder interferometer

    Science.gov (United States)

    Kharraz, Osayd M.; Mohammad, Abu Bakar B.; Ahmad, Harith; Jasim, Ali A.

    2017-07-01

    Functionality improvement of a non-linear semiconductor optical amplifier for multi-wavelength generation is reported. A microfiber Mach-Zehnder interferometer (MMZI) is incorporated to enhance the multi-wavelength generation performance in terms of optical signal-to-noise ratio (OSNR) and full-width-half-maximum linewidth. The proposed scheme offers better dynamic functionality, with flexible tunable and switchable properties. Incorporating the MMZI causes spatial mode beating interference, resulting in narrow bands and power-efficient modes. Tunable and switchable octuple wavelength is demonstrated using non-linear polarization rotation (NPR), with frequency separation with respect to the free spectral range of the implemented MMZI over a greater than 30 nm span. The NPR effect is induced to suppress mode competition within the homogeneous broadening linewidth of the employed semiconductor optical amplifier.

  20. A multiwavelength study of star formation in the vicinity of Galactic HII region Sh2-100

    OpenAIRE

    Samal, M. R.; Pandey, A. K.; Ojha, D. K.; Ghosh, S.K.; Kulkarni, V. K.; Kusakabe, N.; Tamura, M; Bhatt, B. C.; Thompson, M.A.; Sagar, R

    2010-01-01

    We present multiwavelength investigation of morphology, physical-environment, stellar contents and star formation activity in the vicinity of star-forming region Sh 2-100. It is found that the Sh 2-100 region contains seven HII regions of ultracompact and compact nature. The present estimation of distance for three HII regions, along with the kinematic distance for others, suggests that all of them belong to the same molecular cloud complex. Using NIR photometry, we identified the most probab...

  1. Reconstructing the Gamma-Ray Photon Optical Depth of the Universe To Z Approx. 4 from Multiwavelength Galaxy Survey Data

    Science.gov (United States)

    Helgason, Kari; Kashlinsky, Alexander

    2012-01-01

    Reconstructing the Gamma-Ray Photon Optical Depth of the Universe To Z Approx. 4fFrom Multiwavelength Galaxy Survey Data We reconstruct the gamma-ray opacity of the universe out to z approx. photons already at z approx. < 0.2 and reaching tau approx 10 at z = 1. Comparing with the currently available Fermi/LAT gamma-ray burst and blazar data shows that there is room for significant emissions originating in the first stars era.

  2. A widely tunable microwave photonic notch filter with adjustable bandwidth based on multi-wavelength fiber laser

    Science.gov (United States)

    Li, Xin-yang; Cao, Ye; Xu, Dong; Tong, Zheng-rong; Yang, Jing-peng

    2017-07-01

    A widely tunable microwave photonic notch filter with adjustable bandwidth based on multi-wavelength fiber laser is proposed and demonstrated. The multi-wavelength fiber laser generates the multi-taps of the microwave photonic filter (MPF). In order to obtain notch frequency response, a Fourier-domain optical processor (FD-OP) is introduced to control the amplitude and phase of the optical carrier and phase modulation sidebands. By adjusting the polarization controller (PC), different numbers of taps are got, such as 6, 8, 10 and 12. And the wavelength spacing of the multi-wavelength laser is 0.4 nm. The bandwidth of the notch filter is changed by adjusting the number of taps and the corresponding bandwidths are 4.41 GHz, 3.30 GHz, 2.64 GHz and 2.19 GHz, respectively. With the additional phase shift introduced by FD-OP, the notch position is continuously tuned in the whole free spectral range ( FSR) of 27.94 GHz. The center frequency of the notch filter can be continuously tuned from 13.97 GHz to 41.91 GHz.

  3. Multi-wavelength HPLC fingerprints from complex substances: An exploratory chemometrics study of the Cassia seed example.

    Science.gov (United States)

    Ni, Yongnian; Lai, Yanhua; Brandes, Sarina; Kokot, Serge

    2009-08-11

    Multi-wavelength fingerprints of Cassia seed, a traditional Chinese medicine (TCM), were collected by high-performance liquid chromatography (HPLC) at two wavelengths with the use of diode array detection. The two data sets of chromatograms were combined by the data fusion-based method. This data set of fingerprints was compared separately with the two data sets collected at each of the two wavelengths. It was demonstrated with the use of principal component analysis (PCA), that multi-wavelength fingerprints provided a much improved representation of the differences in the samples. Thereafter, the multi-wavelength fingerprint data set was submitted for classification to a suite of chemometrics methods viz. fuzzy clustering (FC), SIMCA and the rank ordering MCDM PROMETHEE and GAIA. Each method highlighted different properties of the data matrix according to the fingerprints from different types of Cassia seeds. In general, the PROMETHEE and GAIA MCDM methods provided the most comprehensive information for matching and discrimination of the fingerprints, and appeared to be best suited for quality assurance purposes for these and similar types of sample.

  4. Multi-wavelength HPLC fingerprints from complex substances: An exploratory chemometrics study of the Cassia seed example

    Energy Technology Data Exchange (ETDEWEB)

    Ni Yongnian, E-mail: ynni@ncu.edu.cn [Stake Laboratory of Food Science and Technology, Nanchang University, Nanchang, Jiangxi 330047 (China); Department of Chemistry, Nanchang University, Nanchang, Jiangxi 330047 (China); Lai Yanhua [Department of Chemistry, Nanchang University, Nanchang, Jiangxi 330047 (China); Brandes, Sarina; Kokot, Serge [Applied Chemistry Cluster, School of Physical and Chemical Sciences, Queensland University of Technology, Brisbane, Queensland 4001 (Australia)

    2009-08-11

    Multi-wavelength fingerprints of Cassia seed, a traditional Chinese medicine (TCM), were collected by high-performance liquid chromatography (HPLC) at two wavelengths with the use of diode array detection. The two data sets of chromatograms were combined by the data fusion-based method. This data set of fingerprints was compared separately with the two data sets collected at each of the two wavelengths. It was demonstrated with the use of principal component analysis (PCA), that multi-wavelength fingerprints provided a much improved representation of the differences in the samples. Thereafter, the multi-wavelength fingerprint data set was submitted for classification to a suite of chemometrics methods viz. fuzzy clustering (FC), SIMCA and the rank ordering MCDM PROMETHEE and GAIA. Each method highlighted different properties of the data matrix according to the fingerprints from different types of Cassia seeds. In general, the PROMETHEE and GAIA MCDM methods provided the most comprehensive information for matching and discrimination of the fingerprints, and appeared to be best suited for quality assurance purposes for these and similar types of sample.

  5. Multiwavelength Study of Quiescent States of Mrk 421 with Unprecedented Hard X-Ray Coverage Provided by NuSTAR in 2013

    CERN Document Server

    Baloković, M.; Madejski, G.; Furniss, A.; Chiang, J.; Ajello, M.; Alexander, D.M.; Barret, D.; Blandford, R.; Boggs, S.E.; Christensen, F.E.; Craig, W.W.; Forster, K.; Giommi, P.; Grefenstette, B.W.; Hailey, C.J.; Harrison, F.A.; Hornstrup, A.; Kitaguchi, T.; Koglin, J.E.; Madsen, K.K.; Mao, P.H.; Miyasaka, H.; Mori, K.; Perri, M.; Pivovaroff, M.J.; Puccetti, S.; Rana, V.; Stern, D.; Tagliaferri, G.; Urry, C.M.; Westergaard, N.J.; Zhang, W.W.; Zoglauer, A.; Archambault, S.; Archer, A.A.; Barnacka, A.; Benbow, W.; Bird, R.; Buckley, J.; Bugaev, V.; Cerruti, M.; Chen, X.; Ciupik, L.; Connolly, M.P.; Cui, W.; Dickinson, H.J.; Dumm, J.; Eisch, J.D.; Falcone, A.; Feng, Q.; Finley, J.P.; Fleischhack, H.; Fortson, L.; Griffin, S.; Griffiths, S.T.; Grube, J.; Gyuk, G.; Huetten, M.; Haakansson, N.; Holder, J.; Humensky, T.B.; Johnson, C.A.; Kaaret, P.; Kertzman, M.; Khassen, Y.; Kieda, D.; Krause, M.; Krennrich, F.; Lang, M.J.; Maier, G.; McArthur, S.; Meagher, K.; Moriarty, P.; Nelson, T.; Nieto, D.; Ong, R.A.; Park, N.; Pohl, M.; Popkow, A.; Pueschel, E.; Reynolds, P.T.; Richards, G.T.; Roache, E.; Santander, M.; Sembroski, G.H.; Shahinyan, K.; Smith, A.W.; Staszak, D.; Telezhinsky, I.; Todd, N.W.; Tucci, J.V.; Tyler, J.; Vincent, S.; Weinstein, A.; Wilhelm, A.; Williams, D.A.; Zitzer, B.; Ahnen, M.L.; Ansoldi, S.; Antonelli, L.A.; Antoranz, P.; Babic, A.; Banerjee, B.; Bangale, P.; Barres de Almeida, U.; Barrio, J.; Becerra González, J.; Bednarek, W.; Bernardini, E.; Biasuzzi, B.; Biland, A.; Blanch, O.; Bonnefoy, S.; Bonnoli, G.; Borracci, F.; Bretz, T.; Carmona, E.; Carosi, A.; Chatterjee, A.; Clavero, R.; Colin, P.; Colombo, E.; Contreras, J.L.; Cortina, J.; Covino, S.; Da Vela, P.; Dazzi, F.; de Angelis, A.; De Lotto, B.; Wilhelmi, E. D. de Oña; Delgado Mendez, C.; Di Pierro, F.; Dominis Prester, D.; Dorner, D.; Doro, M.; Einecke, S.; Elsaesser, D.; Fernández-Barral, A.; Fidalgo, D.; Fonseca, M.V.; Font, L.; Frantzen, K.; Fruck, C.; Galindo, D.; López, R. J. García; Garczarczyk, M.; Garrido Terrats, D.; Gaug, M.; Giammaria, P.; Eisenacher, D.; Godinović, N.; González Muñoz, A.; Guberman, D.; Hahn, A.; Hanabata, Y.; Hayashida, M.; Herrera, J.; Hose, J.; Hrupec, D.; Hughes, G.; Idec, W.; Kodani, K.; Konno, Y.; Kubo, H.; Kushida, J.; La Barbera, A.; Lelas, D.; Lindfors, E.; Lombardi, S.; Longo, F.; López, M.; López-Coto, R.; López-Oramas, A.; Lorenz, E.; Majumdar, P.; Makariev, M.; Mallot, K.; Maneva, G.; Manganaro, M.; Mannheim, K.; Maraschi, L.; Marcote, B.; Mariotti, M.; Martínez, M.; Mazin, D.; Menzel, U.; Miranda, J.M.; Mirzoyan, R.; Moralejo, A.; Moretti, E.; Nakajima, D.; Neustroev, V.; Niedzwiecki, A.; Nievas-Rosillo, M.; Nilsson, K.; Nishijima, K.; Noda, K.; Orito, R.; Overkemping, A.; Paiano, S.; Palacio, S.; Palatiello, M.; Paoletti, R.; Paredes, J.M.; Paredes-Fortuny, X.; Persic, M.; Poutanen, J.; Prada Moroni, P. G.; Prandini, E.; Puljak, I.; Rhode, W.; Ribó, M.; Rico, J.; Garcia, J. Rodriguez; Saito, T.; Satalecka, K.; Scapin, V.; Schultz, C.; Schweizer, T.; Shore, S.N.; Sillanpää, A.; Sitarek, J.; Snidaric, I.; Sobczynska, D.; Stamerra, A.; Steinbring, T.; Strzys, M.; Takalo, L.O.; Takami, H.; Tavecchio, F.; Temnikov, P.; Terzić, T.; Tescaro, D.; Teshima, M.; Thaele, J.; Torres, D.F.; Toyama, T.; Treves, A.; Verguilov, V.; Vovk, I.; Ward, J.E.; Will, M.; Wu, M.H.; Zanin, R.; Perkins, J.; Verrecchia, F.; Leto, C.; Böttcher, M.; Villata, M.; Raiteri, C.M.; Acosta-Pulido, J.A.; Bachev, R.; Berdyugin, A.; Blinov, D.A.; Carnerero, M.I.; Chen, W.P.; Chinchilla, P.; Damljanovic, G.; Eswaraiah, C.; Grishina, T.S.; Ibryamov, S.; Jordan, B.; Jorstad, S.G.; Joshi, M.; Kopatskaya, E.N.; Kurtanidze, O.M.; Kurtanidze, S.O.; Larionova, E.G.; Larionova, L.V.; Larionov, V.M.; Latev, G.; Lin, H.C.; Marscher, A.P.; Mokrushina, A.A.; Morozova, D.A.; Nikolashvili, M.G.; Semkov, E.; Strigachev, A.; Troitskaya, Yu. V.; Troitsky, I.S.; Vince, O.; Barnes, J.; Güver, T.; Moody, J.W.; Sadun, A.C.; Sun, S.; Hovatta, T.; Richards, J.L.; Max-Moerbeck, W.; Readhead, A.C.; Lähteenmäki, A.; Tornikoski, M.; Tammi, J.; Ramakrishnan, V.; Reinthal, R.; Angelakis, E.; Fuhrmann, L.; Myserlis, I.; Karamanavis, V.; Sievers, A.; Ungerechts, H.; Zensus, J.A.

    2016-01-01

    We present coordinated multiwavelength observations of the bright, nearby BL Lac object Mrk 421 taken in 2013 January-March, involving GASP-WEBT, Swift, NuSTAR, Fermi-LAT, MAGIC, VERITAS, and other collaborations and instruments, providing data from radio to very-high-energy (VHE) gamma-ray bands. NuSTAR yielded previously unattainable sensitivity in the 3-79 keV range, revealing that the spectrum softens when the source is dimmer until the X-ray spectral shape saturates into a steep power law with a photon index of approximately 3, with no evidence for an exponential cutoff or additional hard components up to about 80 keV. For the first time, we observed both the synchrotron and the inverse-Compton peaks of the spectral energy distribution (SED) simultaneously shifted to frequencies below the typical quiescent state by an order of magnitude. The fractional variability as a function of photon energy shows a double-bump structure which relates to the two bumps of the broadband SED. In each bump, the variabilit...

  6. Detection of GeV Gamma-Rays from HESS J1534-571 and Multiwavelength Implications for the Origin of the Nonthermal Emission

    Science.gov (United States)

    Araya, Miguel

    2017-07-01

    HESS J1534-571 is a very high-energy gamma-ray source that was discovered by the H.E.S.S. observatory and reported as one of several new sources with a shell-like morphology at TeV energies, matching in size and location with the supernova remnant (SNR) G323.7-1.0 discovered in radio observations by the Molonglo Galactic Plane Survey. Many known TeV shells also show X-ray emission however, no X-ray counterpart has been seen for HESS J1534-571. The detection of a new GeV source using data from the Fermi satellite that is compatible in extension with the radio SNR and shows a very hard power-law spectrum ≤ft(\\tfrac{{dN}}{{dE}}\\propto {E}-1.35\\right) is presented here, together with the first broadband modeling of the nonthermal emission from this source. It is shown that leptonic emission is compatible with the known multiwavelength data and a corresponding set of physical source parameters is given. The required total energy budget in leptons is reasonable, ˜1.5 × 1048 erg for a distance to the object of 5 kpc. The new GeV observations imply that a hadronic scenario, on the other hand, requires a cosmic-ray spectrum that deviates considerably from theoretical expectations of particle acceleration.

  7. De-blending deep Herschel surveys: A multi-wavelength approach

    Science.gov (United States)

    Pearson, W. J.; Wang, L.; van der Tak, F. F. S.; Hurley, P. D.; Burgarella, D.; Oliver, S. J.

    2017-07-01

    Aims: Cosmological surveys in the far-infrared are known to suffer from confusion. The Bayesian de-blending tool, XID+, currently provides one of the best ways to de-confuse deep Herschel SPIRE images, using a flat flux density prior. This work is to demonstrate that existing multi-wavelength data sets can be exploited to improve XID+ by providing an informed prior, resulting in more accurate and precise extracted flux densities. Methods: Photometric data for galaxies in the COSMOS field were used to constrain spectral energy distributions (SEDs) using the fitting tool CIGALE. These SEDs were used to create Gaussian prior estimates in the SPIRE bands for XID+. The multi-wavelength photometry and the extracted SPIRE flux densities were run through CIGALE again to allow us to compare the performance of the two priors. Inferred ALMA flux densities (FinferALMA), at 870 μm and 1250 μm, from the best fitting SEDs from the second CIGALE run were compared with measured ALMA flux densities (FmeasALMA) as an independent performance validation. Similar validations were conducted with the SED modelling and fitting tool MAGPHYS and modified black-body functions to test for model dependency. Results: We demonstrate a clear improvement in agreement between the flux densities extracted with XID+ and existing data at other wavelengths when using the new informed Gaussian prior over the original uninformed prior. The residuals between FmeasALMA and FinferALMA were calculated. For the Gaussian priors these residuals, expressed as a multiple of the ALMA error (σ), have a smaller standard deviation, 7.95σ for the Gaussian prior compared to 12.21σ for the flat prior; reduced mean, 1.83σ compared to 3.44σ; and have reduced skew to positive values, 7.97 compared to 11.50. These results were determined to not be significantly model dependent. This results in statistically more reliable SPIRE flux densities and hence statistically more reliable infrared luminosity estimates. Herschel

  8. THE SCUBA-2 COSMOLOGY LEGACY SURVEY: MULTIWAVELENGTH COUNTERPARTS TO 10{sup 3} SUBMILLIMETER GALAXIES IN THE UKIDSS-UDS FIELD

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chian-Chou; Smail, Ian; Ma, Cheng-Jiun; Simpson, James M.; Swinbank, A. Mark [Centre for Extragalactic Astronomy, Department of Physics, Durham University, South Road, Durham DH1 3LE (United Kingdom); Ivison, Rob J.; Arumugam, Vinodiran; Mortlock, Alice; Dunlop, James S.; Michałowski, Michał J. [Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Almaini, Omar; Conselice, Christopher J.; Hartley, Will G. [University of Nottingham, School of Physics and Astronomy, Nottingham, NG7 2RD (United Kingdom); Geach, James E. [Center for Astrophysics Research, Science and Technology Research Institute, University of Hertfordshire, Hatfield AL10 9AB (United Kingdom); Simpson, Chris [Astrophysics Research Institute, Liverpool John Moores University, Liverpool Science Park, 146 Brownlow Hill, Liverpool L3 5RF (United Kingdom); Aretxaga, Itziar [Instituto Nacional de Astrofísica, Óptica y Electrónica (INAOE), Luis Enrique Erro 1, Sta. Ma. Tonantzintla, Puebla (Mexico); Blain, Andrew [Physics and Astronomy, University of Leicester, Leicester, LE1 7RH (United Kingdom); Chapman, Scott C. [Department of Physics and Atmospheric Science, Dalhousie University, 6310 Coburg Road, Halifax, NS B3H 4R2 (Canada); Farrah, Duncan [Department of Physics, Virginia Tech, Blacksburg, VA 24061 (United States); Halpern, Mark [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada); and others

    2016-04-01

    We present multiwavelength identifications for the counterparts of 1088 submillimeter sources detected at 850 μm in the SCUBA-2 Cosmology Legacy Survey study of the UKIRT Infrared Deep Sky Survey-Ultra-Deep Survey (UDS) field. By utilizing an Atacama Large Millimeter Array (ALMA) pilot study on a subset of our bright SCUBA-2 sample as a training set, along with the deep optical–near-infrared (OIR) data available in this field, we develop a novel technique, Optical–IR Triple Color (OIRTC), using z − K, K − [3.6], [3.6] − [4.5] colors to select the candidate submillimeter galaxy (SMG) counterparts. By combining radio identification and the OIRTC technique, we find counterpart candidates for 80% of the Class = 1 ≥ 4σ SCUBA-2 sample, defined as those that are covered by both radio and OIR imaging and the base sample for our scientific analyses. Based on the ALMA training set, we expect the accuracy of these identifications to be 82% ± 20%, with a completeness of 69% ± 16%, essentially as accurate as the traditional p-value technique but with higher completeness. We find that the fraction of SCUBA-2 sources having candidate counterparts is lower for fainter 850 μm sources, and we argue that for follow-up observations sensitive to SMGs with S{sub 850} ≳ 1 mJy across the whole ALMA beam, the fraction with multiple counterparts is likely to be >40% for SCUBA-2 sources at S{sub 850} ≳ 4 mJy. We find that the photometric redshift distribution for the SMGs is well fit by a lognormal distribution, with a median redshift of z = 2.3 ± 0.1. After accounting for the sources without any radio and/or OIRTC counterpart, we estimate the median redshift to be z = 2.6 ± 0.1 for SMGs with S{sub 850} > 1 mJy. We also use this new large sample to study the clustering of SMGs and the far-infrared properties of the unidentified submillimeter sources by stacking their Herschel SPIRE far-infrared emission.

  9. Precision interferometry for measuring wavefronts of multi-wavelength optical pickups.

    Science.gov (United States)

    Ge, Zongtao; Saito, Takayuki; Kurose, Minoru; Kanda, Hideo; Arakawa, Kazuhisa; Takeda, Mitsuo

    2008-01-07

    A novel wavefront measurement interferometer is developed that enables the user to evaluate the wavefronts of multi-wavelength optical pickups. In this interferometer, instead of transparent pinholes used in Mach-Zehnder interferometers, reflection dot pinhole mirrors are used to generate reference wavefronts for different wavelengths which make the optical system very flexible and simple compared with those using transparent pinholes. The interferometer is designed to operate at wavelengths of 405 nm, 650 nm and 780 nm over an NA range of up to 0.95, which is very difficult to realize when transparent pinholes are used for generating reference wavefronts. The three-beam problem is solved and the optics of the interferometer is simplified by employing a software filter instead of using spatial filters in the optics of the interferometer. The instrument has an equal optical path length that enables the user to measure pickups with a very short coherence length. A new method by which asymmetric aberration components, such as astigmatic and coma aberrations, can be calibrated by rotating the measured lens with 90 and 180 degrees is proposed and the calibration results are verified by using a high precision reference point source. System accuracy is also evaluated by comparing with the measurement results obtained by commercial Fizeau type interferometer and a good agreement is achieved.

  10. Characterization of female breast lesions from multi-wavelength time-resolved optical mammography

    Energy Technology Data Exchange (ETDEWEB)

    Spinelli, Lorenzo [INFM-Dipartimento di Fisica and IFN-CNR, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milan (Italy); Torricelli, Alessandro [INFM-Dipartimento di Fisica and IFN-CNR, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milan (Italy); Pifferi, Antonio [INFM-Dipartimento di Fisica and IFN-CNR, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milan (Italy); Taroni, Paola [INFM-Dipartimento di Fisica and IFN-CNR, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milan (Italy); Danesini, Gianmaria [Dipartimento di Radiologia, Casa di Cura S. Pio X, via Francesco Nava 31, I-20159 Milan (Italy); Cubeddu, Rinaldo [INFM-Dipartimento di Fisica and IFN-CNR, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milan (Italy)

    2005-06-07

    Characterization of both malignant and benign lesions in the female breast is presented as the result of a clinical study that involved more than 190 subjects in the framework of the OPTIMAMM European project. All the subjects underwent optical mammography, by means of a multi-wavelength time-resolved mammograph, in the range 637-985 nm. Optical images were processed by applying a perturbation model, relying on a nonlinear approximation of time-resolved transmittance curves in the presence of an inclusion, with the aim of estimating the major tissue constituents (i.e. oxy- and deoxy-haemoglobin, lipid and water) and structural parameters (linked to dimension and density of the scatterer centres) for both the lesion area and the surrounding tissue. The critical factors for the application of the perturbation model on in vivo data are also discussed. Forty-six malignant and 68 benign lesions were analysed. A subset of 32 cancers, 40 cysts and 14 fibroadenomas were found reliable for the perturbation analysis. For cancers, we show a higher blood content with respect to the surrounding tissue, while cysts are characterized by a lower concentration of scattering centres with respect to the surrounding tissue. For fibroadenomas, the low number of cases does not allow any definite conclusions.

  11. Noninvasive cerebral blood oxygenation monitoring: clinical test of multiwavelength optoacoustic system

    Science.gov (United States)

    Petrov, Y. Y.; Prough, D. S.; Petrova, I.; Patrikeev, I. A.; Cicenaite, I.; Esenaliev, R. O.

    2007-02-01

    Continuous monitoring of cerebral blood oxygenation is critically important for treatment of patients with life-threatening conditions like severe brain injury or during cardiac surgery. We designed and built a novel multiwavelength optoacoustic system for noninvasive, continuous, and accurate monitoring of cerebral blood oxygenation. We use an Optical Parametric Oscillator as a light source. We successfully tested the system in vitro as well as in vivo in large animals (sheep) through thick tissues overlying blood vessels which drain venous blood out of the brain (e.g., superior sagittal sinus or jugular vein). Here we present the results of clinical tests of the system for continuous noninvasive cerebral blood oxygenation monitoring in the internal jugular vein of healthy volunteers. We applied our custom-built optoacoustic probe (which incorporated a wide-band acoustic transducer and an optical fiber) to the neck area overlying the internal jugular vein. We performed measurements with volunteers at 18 wavelengths in the near-infrared spectral range. Despite a thick layer of overlying connective tissue and low energy used in the experiments, we recorded signals with high signal-to-noise ratios for all volunteers. We found that the temporal (independent of signal amplitude) parameters of recorded profiles for different levels of blood oxygenation correlated well with the spectrum of effective attenuation coefficients of blood.

  12. Tunable multiwavelength Tm-doped fiber laser based on the multimode interference effect.

    Science.gov (United States)

    Zhang, Peng; Wang, Tianshu; Ma, Wanzhuo; Dong, Keyan; Jiang, Huilin

    2015-05-20

    A simple multiwavelength Tm-doped fiber laser at the 2 μm band based on multimode interference (MMI) is proposed and experimentally demonstrated. In this scheme, a 4 m Tm-doped single-mode fiber is pumped by a 1568 nm laser, and a single-mode-multimode-single-mode (SMS) fiber structure is used as an MMI filter in which the multimode fiber is used to tune the laser. Laser operation of up to three wavelengths is obtained based on the MMI filter. The wavelengths can be tuned by adjusting the polarization controller and rotating the multimode fiber in the SMS structure, and the tuning region is about 24 nm, i.e., 1892-1916 nm. The side-mode suppression ratio of the laser is about 54 dB. The 3 dB linewidth is less than 0.04 nm. Peak fluctuation at each wavelength is analyzed, and the results show that the power fluctuation is less than 3 dB around the average power.

  13. Color correction for chromatic distortion in a multi-wavelength digital holographic system

    Science.gov (United States)

    Lin, Li-Chien; Tu, Han-Yen; Lai, Xin-Ji; Huang, Yi-Lun; Cheng, Chau-Jern

    2011-05-01

    A multi-wavelength digital holographic (MWDH) system has been developed to record and reconstruct color images. In comparison to working with digital cameras, however, high-quality color reproduction is difficult to achieve, because of the imperfections from the light sources, optical components, optical recording devices and recording processes. Thus, we face the problem of correcting the colors altered during the digital holographic process. We therefore propose a color correction scheme to correct the chromatic distortion caused by the MWDH system. The scheme consists of two steps: (1) creating a color correction profile and (2) applying it to the correction of the distorted colors. To create the color correction profile, we generate two algorithms: the sequential algorithm and the integrated algorithm. The ColorChecker is used to generate the distorted colors and their desired corrected colors. The relationship between these two color patches is fixed into a specific mathematical model, the parameters of which are estimated, creating the profile. Next, the profile is used to correct the color distortion of images, capturing and preserving the original vibrancy of the reproduced colors for different reconstructed images.

  14. Surface roughness prediction model and experimental results based on multi-wavelength fiber optic sensors.

    Science.gov (United States)

    Zhu, Nan-Nan; Zhang, Jun

    2016-10-31

    The surface roughness prediction model based on a support vector machine was proposed and the multi-wavelength fiber optic sensor was established. The specimens with different surface roughness selected as the test samples were analyzed by using the prediction model when the incident wavelengths were 650 nm and 1310 nm, respectively. The working distance of 2.5 mm ~3.5 mm was chosen as the optimum measurement distance. The experimental results indicate that the error range of surface roughness is 0.74% ~7.56% at 650 nm, and the error range of surface roughness is 1.03% ~5.92% at 1310 nm. The average relative error is about 2.669% at 650 nm, while it is about 2.431% at 1310 nm. The error of roughness measurement is less than 3% by using the model, which is acceptable. The error of surface roughness based on the prediction model is smaller than that by using the characteristic curves between surface roughness and the scattering intensity ratio.

  15. Multiwavelength diode-laser absorption spectroscopy using external intensity modulation by semiconductor optical amplifiers.

    Science.gov (United States)

    Karagiannopoulos, Solon; Cheadle, Edward; Wright, Paul; Tsekenis, Stylianos; McCann, Hugh

    2012-12-01

    A novel opto-electronic scheme for line-of-sight Near-IR gas absorption measurement based on direct absorption spectroscopy (DAS) is reported. A diode-laser-based, multiwavelength system is designed for future application in nonintrusive, high temporal resolution tomographic imaging of H2O in internal combustion engines. DAS is implemented with semiconductor optical amplifiers (SOAs) to enable wavelength multiplexing and to induce external intensity modulation for phase-sensitive detection. Two overtone water transitions in the Near-IR have been selected for ratiometric temperature compensation to enable concentration measurements, and an additional wavelength is used to account for nonabsorbing attenuation. A wavelength scanning approach was used to evaluate the new modulation technique, and showed excellent absorption line recovery. Fixed-wavelength, time-division-multiplexing operation with SOAs has also been demonstrated. To the best of our knowledge this is the first time SOAs have been used for modulation and switching in a spectroscopic application. With appropriate diode laser selection this scheme can be also used for other chemical species absorption measurements.

  16. Two-Step Calibration of a Multiwavelength Pyrometer for High Temperature Measurement Using a Quartz Lamp

    Science.gov (United States)

    Ng, Daniel

    2001-01-01

    There is no theoretical upper temperature limit for pyrometer application in temperature measurements. NASA Glenn's multiwavelength pyrometer can make measurements over wide temperature ranges. However, the radiation spectral response of the pyrometer's detector must be calibrated before any temperature measurement is attempted, and it is recommended that calibration be done at temperatures close to those for which measurements will be made. Calibration is a determination of the constants of proportionality at all wavelengths between the detector's output (voltage) and its input signals (usually from a blackbody radiation source) in order to convert detector output into radiation intensity. To measure high temperatures, the detectors are chosen to be sensitive in the spectral range from 0.4 to 2.5 micrometers. A blackbody furnace equilibrated at around 1000 C is often used for this calibration. Though the detector may respond sensitively to short wavelengths radiation, a blackbody furnace at 1000 C emits only feebly at very short wavelengths. As a consequence, the calibration constants that result may not be the most accurate. For pyrometry calibration, a radiation source emitting strongly at the short wavelengths is preferred. We have chosen a quartz halogen lamp for this purpose.

  17. Cobinamide-Based Cyanide Analysis by Multiwavelength Spectrometry in a Liquid Core Waveguide

    Science.gov (United States)

    Ma, Jian; Dasgupta, Purnendu K.; Blackledge, William; Boss, Gerry R.

    2010-01-01

    A novel cyanide analyzer based on sensitive cobinamide chemistry relies on simultaneous reagent and sample injection and detection in a 50 cm liquid core waveguide (LCW) flow cell illuminated by a white light emitting diode. The transmitted light is read by a fiber-optic charge coupled device (CCD) spectrometer. Alkaline cobinamide (orange, λmax = 510 nm) changes to violet (λmax = 583 nm) upon reaction with cyanide. Multiwavelength detection permits built-in correction for artifact responses intrinsic to a single-line flow injection system and corrects for drift. With optimum choice of the reaction medium, flow rate, and mixing coil length, the limit of detection (LOD, S/N = 3) is 30 nM and the linear dynamic range extends to 10 μM. The response base width for 1% carryover is cyanide. The sulfide product actually has a different characteristic absorption, and in those samples where significant presence is likely, this can be corrected for. We demonstrate applicability by analyzing the hydrolytic cyanide extract of apple and pear seeds with orange seeds as control and also measure HCN in breath air samples. Spike recoveries in these sample extracts ranged from 91 to 108%. PMID:20560532

  18. Multi-Wavelength Based Optical Density Sensor for Autonomous Monitoring of Microalgae

    Science.gov (United States)

    Jia, Fei; Kacira, Murat; Ogden, Kimberly L.

    2015-01-01

    A multi-wavelength based optical density sensor unit was designed, developed, and evaluated to monitor microalgae growth in real time. The system consisted of five main components including: (1) laser diode modules as light sources; (2) photodiodes as detectors; (3) driver circuit; (4) flow cell; and (5) sensor housing temperature controller. The sensor unit was designed to be integrated into any microalgae culture system for both real time and non-real time optical density measurements and algae growth monitoring applications. It was shown that the sensor unit was capable of monitoring the dynamics and physiological changes of the microalgae culture in real-time. Algae biomass concentration was accurately estimated with optical density measurements at 650, 685 and 780 nm wavelengths used by the sensor unit. The sensor unit was able to monitor cell concentration as high as 1.05 g·L−1 (1.51 × 108 cells·mL−1) during the culture growth without any sample preparation for the measurements. Since high cell concentrations do not need to be diluted using the sensor unit, the system has the potential to be used in industrial microalgae cultivation systems for real time monitoring and control applications th