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Sample records for spectra elliptic flow

  1. Spectra and elliptic flow for Λ, Ξ, and Ω in 200 A GeV Au+Au collisions

    NASA Astrophysics Data System (ADS)

    Zhu, Xiangrong; Song, Huichao

    2016-01-01

    Using VISHNU hybrid model, we calculate the pT-spectra and elliptic flow of Λ, Ξ, and Ω in 200 A GeV Au+Au collisions. Comparisons with the STAR measurements show that the model generally describes these soft hadron data. We also briefly study and discuss the mass ordering of elliptic flow among π, K, p, Λ, Ξ, and Ω in minimum bias Au+Au collisions.

  2. Spectra and elliptic flow for identified hadrons in 2.76A TeV Pb + Pb collisions

    NASA Astrophysics Data System (ADS)

    Song, Huichao; Bass, Steffen A.; Heinz, Ulrich

    2014-03-01

    Using the vishnu hybrid model that couples (2+1)-dimensional viscous hydrodynamics to a microscopic hadronic transport model, we calculate the multiplicity, pT spectra, and elliptic flow for pions, kaons, and protons in 2.76A TeV Pb+Pb collisions, using mc-kln initializations with smoothed initial conditions, obtained by averaging over a large number of events. The results from our calculations are compared to data from the ALICE Collaboration, showing nice agreement over several centrality bins. Using the same inputs, we predict the pT spectra and elliptic flow for ϕ mesons and explore their flow development in the strong and weak coupling limits through hydrodynamic calculations with different decoupling temperatures. In addition we study the influence of baryon and antibaryon annihilation processes on common observables and demonstrate that, by including annihilation processes below a switching temperature of 165 MeV, vishnu provides a good description of the multiplicity and pT spectra for pions, kaons, and protons measured by PHENIX and ALICE at both the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC).

  3. Systematic parameter study of hadron spectra and elliptic flow from viscous hydrodynamic simulations of Au+Au collisions at {radical}(s{sub NN})=200 GeV

    SciTech Connect

    Shen Chun; Heinz, Ulrich; Huovinen, Pasi; Song, Huichao

    2010-11-15

    Using the (2+1)-dimensional viscous hydrodynamic code vish2+1[H. Song and U. Heinz, Phys. Lett. B 658, 279 (2008); H. Song and U. Heinz, Phys. Rev. C 77, 064901 (2008); H. Song, Ph. D. thesis, The Ohio State University, 2009], we present systematic studies of the dependence of pion and proton transverse-momentum spectra and their elliptic flow in 200A GeV Au+Au collisions on the parameters of the hydrodynamic model (thermalization time, initial entropy density distribution, decoupling temperature, equation of state, and specific shear viscosity {eta}/s). We identify a tension between the slope of the proton spectra, which (within hydrodynamic simulations that assume a constant shear viscosity to entropy density ratio) prefer larger {eta}/s values, and the slope of the p{sub T} dependence of charged hadron elliptic flow, which prefers smaller values of {eta}/s. Changing other model parameters does not appear to permit dissolution of this tension.

  4. Systematic parameter study of hadron spectra and elliptic flow from viscous hydrodynamic simulations of Au+Au collisions at sNN=200 GeV

    NASA Astrophysics Data System (ADS)

    Shen, Chun; Heinz, Ulrich; Huovinen, Pasi; Song, Huichao

    2010-11-01

    Using the (2+1)-dimensional viscous hydrodynamic code vish2+1 [H. Song and U. Heinz, Phys. Lett. BPYLBAJ0370-269310.1016/j.physletb.2007.11.019 658, 279 (2008); H. Song and U. Heinz, Phys. Rev. CPRVCAN0556-281310.1103/PhysRevC.77.064901 77, 064901 (2008); H. Song, Ph. D. thesis, The Ohio State University, 2009], we present systematic studies of the dependence of pion and proton transverse-momentum spectra and their elliptic flow in 200A GeV Au+Au collisions on the parameters of the hydrodynamic model (thermalization time, initial entropy density distribution, decoupling temperature, equation of state, and specific shear viscosity η/s). We identify a tension between the slope of the proton spectra, which (within hydrodynamic simulations that assume a constant shear viscosity to entropy density ratio) prefer larger η/s values, and the slope of the pT dependence of charged hadron elliptic flow, which prefers smaller values of η/s. Changing other model parameters does not appear to permit dissolution of this tension.

  5. Radial and elliptic flow at RHIC: Further predictions

    SciTech Connect

    Huovinen, Pasi; Kolb, Peter F.; Heinz, Ulrich; Ruuskanen, P.V.; Voloshin, Sergei A.

    2001-01-30

    Using a hydrodynamic model, we predict the transverse momentum dependence of the spectra and the elliptic flow for different hadrons in Au+Au collisions at sqrt(s)=130 AGeV. The dependence of the differential and p{_}t-integrated elliptic flow on the hadron mass, equation of state and freeze-out temperature is studied both numerically and analytically.

  6. Event-shape engineering for inclusive spectra and elliptic flow in Pb-Pb collisions at √{sNN}=2.76 TeV

    NASA Astrophysics Data System (ADS)

    Adam, J.; Adamová, D.; Aggarwal, M. M.; Aglieri Rinella, G.; Agnello, M.; Agrawal, N.; Ahammed, Z.; Ahn, S. U.; Aimo, I.; Aiola, S.; Ajaz, M.; Akindinov, A.; Alam, S. N.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Alfaro Molina, R.; Alici, A.; Alkin, A.; Almaraz, J. R. M.; Alme, J.; Alt, T.; Altinpinar, S.; Altsybeev, I.; Alves Garcia Prado, C.; Andrei, C.; Andronic, A.; Anguelov, V.; Anielski, J.; Antičić, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Arcelli, S.; Armesto, N.; Arnaldi, R.; Arsene, I. C.; Arslandok, M.; Audurier, B.; Augustinus, A.; Averbeck, R.; Azmi, M. D.; Bach, M.; Badalà, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bala, R.; Baldisseri, A.; Baltasar Dos Santos Pedrosa, F.; Baral, R. C.; Barbano, A. M.; Barbera, R.; Barile, F.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartalini, P.; Barth, K.; Bartke, J.; Bartsch, E.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Batista Camejo, A.; Batyunya, B.; Batzing, P. C.; Bearden, I. G.; Beck, H.; Bedda, C.; Behera, N. K.; Belikov, I.; Bellini, F.; Bello Martinez, H.; Bellwied, R.; Belmont, R.; Belmont-Moreno, E.; Belyaev, V.; Bencedi, G.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Bertens, R. A.; Berzano, D.; Betev, L.; Bhasin, A.; Bhat, I. R.; Bhati, A. K.; Bhattacharjee, B.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Biswas, R.; Biswas, S.; Bjelogrlic, S.; Blair, J. T.; Blanco, F.; Blau, D.; Blume, C.; Bock, F.; Bogdanov, A.; Bøggild, H.; Boldizsár, L.; Bombara, M.; Book, J.; Borel, H.; Borissov, A.; Borri, M.; Bossú, F.; Botta, E.; Böttger, S.; Braun-Munzinger, P.; Bregant, M.; Breitner, T.; Broker, T. A.; Browning, T. A.; Broz, M.; Brucken, E. J.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buncic, P.; Busch, O.; Buthelezi, Z.; Butt, J. B.; Buxton, J. T.; Caffarri, D.; Cai, X.; Caines, H.; Calero Diaz, L.; Caliva, A.; Calvo Villar, E.; Camerini, P.; Carena, F.; Carena, W.; Carnesecchi, F.; Castillo Castellanos, J.; Castro, A. J.; Casula, E. A. R.; Cavicchioli, C.; Ceballos Sanchez, C.; Cepila, J.; Cerello, P.; Cerkala, J.; Chang, B.; Chapeland, S.; Chartier, M.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Chelnokov, V.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chibante Barroso, V.; Chinellato, D. D.; Chochula, P.; Choi, K.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Chunhui, Z.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Colocci, M.; Conesa Balbastre, G.; Conesa Del Valle, Z.; Connors, M. E.; Contreras, J. G.; Cormier, T. M.; Corrales Morales, Y.; Cortés Maldonado, I.; Cortese, P.; Cosentino, M. R.; Costa, F.; Crochet, P.; Cruz Albino, R.; Cuautle, E.; Cunqueiro, L.; Dahms, T.; Dainese, A.; Danu, A.; Das, D.; Das, I.; Das, S.; Dash, A.; Dash, S.; de, S.; de Caro, A.; de Cataldo, G.; de Cuveland, J.; de Falco, A.; de Gruttola, D.; De Marco, N.; de Pasquale, S.; Deisting, A.; Deloff, A.; Dénes, E.; D'Erasmo, G.; di Bari, D.; di Mauro, A.; di Nezza, P.; Diaz Corchero, M. A.; Dietel, T.; Dillenseger, P.; Divià, R.; Djuvsland, Ø.; Dobrin, A.; Dobrowolski, T.; Domenicis Gimenez, D.; Dönigus, B.; Dordic, O.; Drozhzhova, T.; Dubey, A. K.; Dubla, A.; Ducroux, L.; Dupieux, P.; Ehlers, R. J.; Elia, D.; Engel, H.; Erazmus, B.; Erdemir, I.; Erhardt, F.; Eschweiler, D.; Espagnon, B.; Estienne, M.; Esumi, S.; Eum, J.; Evans, D.; Evdokimov, S.; Eyyubova, G.; Fabbietti, L.; Fabris, D.; Faivre, J.; Fantoni, A.; Fasel, M.; Feldkamp, L.; Felea, D.; Feliciello, A.; Feofilov, G.; Ferencei, J.; Fernández Téllez, A.; Ferreiro, E. G.; Ferretti, A.; Festanti, A.; Feuillard, V. J. G.; Figiel, J.; Figueredo, M. A. S.; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Fleck, M. G.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; Frankenfeld, U.; Fuchs, U.; Furget, C.; Furs, A.; Fusco Girard, M.; Gaardhøje, J. J.; Gagliardi, M.; Gago, A. M.; Gallio, M.; Gangadharan, D. R.; Ganoti, P.; Gao, C.; Garabatos, C.; Garcia-Solis, E.; Gargiulo, C.; Gasik, P.; Germain, M.; Gheata, A.; Gheata, M.; Ghosh, P.; Ghosh, S. K.; Gianotti, P.; Giubellino, P.; Giubilato, P.; Gladysz-Dziadus, E.; Glässel, P.; Goméz Coral, D. M.; Gomez Ramirez, A.; González-Zamora, P.; Gorbunov, S.; Görlich, L.; Gotovac, S.; Grabski, V.; Graczykowski, L. K.; Graham, K. L.; Grelli, A.; Grigoras, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Grosse-Oetringhaus, J. F.; Grossiord, J.-Y.; Grosso, R.; Guber, F.; Guernane, R.; Guerzoni, B.; Gulbrandsen, K.; Gulkanyan, H.; Gunji, T.; Gupta, A.; Gupta, R.

    2016-03-01

    We report on results obtained with the event-shape engineering technique applied to Pb-Pb collisions at √{sNN}=2.76 TeV. By selecting events in the same centrality interval, but with very different average flow, different initial-state conditions can be studied. We find the effect of the event-shape selection on the elliptic flow coefficient v2 to be almost independent of transverse momentum pT, which is as expected if this effect is attributable to fluctuations in the initial geometry of the system. Charged-hadron, -pion, -kaon, and -proton transverse momentum distributions are found to be harder in events with higher-than-average elliptic flow, indicating an interplay between radial and elliptic flow.

  7. ELLIPTIC FLOW FROM COLOR GLASS CONDENSATE.

    SciTech Connect

    KRASNITZ,A.; NARA,Y.; VENUGOPALAN,R.

    2002-07-18

    We show that an observable fraction of the measured elliptic flow may originate in classical gluon fields at the initial stage of a peripheral high-energy nuclear collision. This mechanism complements the contribution of late stage mechanisms, such as those described by hydrodynamics, to the observed elliptic flow.

  8. Elliptic flow: a brief review

    NASA Astrophysics Data System (ADS)

    Snellings, Raimond

    2011-05-01

    One of the fundamental questions in the field of subatomic physics is the question of what happens to matter at extreme densities and temperatures as may have existed in the first microseconds after the Big Bang and exists, perhaps, in the core of dense neutron stars. The aim of heavy-ion physics is to collide nuclei at very high energies and thereby create such a state of matter in the laboratory. The experimental program began in the 1990s with collisions made available at the Brookhaven Alternating Gradient Synchrotron (AGS) and the CERN Super Proton Synchrotron (SPS), and continued at the Brookhaven Relativistic Heavy-Ion Collider (RHIC) with the maximum center-of-mass energies of \\sqrt{s_{NN}} = 4.75 , 17.2 and 200 GeV, respectively. Collisions of heavy ions at the unprecedented energy of 2.76 TeV recently became available at the LHC collider at CERN. In this review, I give a brief introduction to the physics of ultrarelativistic heavy-ion collisions and discuss the current status of elliptic flow measurements.

  9. Three-dimensional instability of elliptical flow

    NASA Astrophysics Data System (ADS)

    Bayly, B. J.

    1986-10-01

    A clarification of the physical and mathematical nature of Pierrhumbert's (1986) three-dimensional short-wave inviscid instability of simple two-dimensional elliptical flow is presented. The instabilities found are independent of length scale, extending Pierrhumbert's conclusion that the structures of the instabilities are independent of length scale in the limit of large wave number. The fundamental modes are exact solutions of the nonlinear equations, and they are plane waves whose wave vector rotates elliptically around the z axis with a period of 2(pi)/Omega. The growth rates are shown to be the exponents of a matrix Floquet problem, and good agreement is found with previous results.

  10. Elliptic Flow, Initial Eccentricity and Elliptic Flow Fluctuations in Heavy Ion Collisions at RHIC

    NASA Astrophysics Data System (ADS)

    Nouicer, Rachid; Alver, B.; Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Busza, W.; Carroll, A.; Chai, Z.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Halliwell, C.; Hamblen, J.; Hauer, M.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Holzman, B.; Iordanova, A.; Kane, J. L.; Khan, N.; Kulinich, P.; Kuo, C. M.; Li, W.; Lin, W. T.; Loizides, C.; Manly, S.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Reed, C.; Roland, C.; Roland, G.; Sagerer, J.; Seals, H.; Sedykh, I.; Smith, C. E.; Stankiewicz, M. A.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tonjes, M. B.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Vaurynovich, S. S.; Verdier, R.; Veres, G. I.; Walters, P.; Wenger, E.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wysłouch, B.

    2008-12-01

    We present measurements of elliptic flow and event-by-event fluctuations established by the PHOBOS experiment. Elliptic flow scaled by participant eccentricity is found to be similar for both systems when collisions with the same number of participants or the same particle area density are compared. The agreement of elliptic flow between Au+Au and Cu+Cu collisions provides evidence that the matter is created in the initial stage of relativistic heavy ion collisions with transverse granularity similar to that of the participant nucleons. The event-by-event fluctuation results reveal that the initial collision geometry is translated into the final state azimuthal particle distribution, leading to an event-by-event proportionality between the observed elliptic flow and initial eccentricity.

  11. Effect of flow fluctuations and nonflow on elliptic flow methods

    SciTech Connect

    Ollitrault, Jean-Yves; Poskanzer, Arthur M.; Voloshin, Sergei A.

    2009-04-16

    We discuss how the different estimates of elliptic flow are influenced by flow fluctuations and nonflow effects. It is explained why the event-plane method yields estimates between the two-particle correlation methods and the multiparticle correlation methods. It is argued that nonflow effects and fluctuations cannot be disentangled without other assumptions. However, we provide equations where, with reasonable assumptions about fluctuations and nonflow, all measured values of elliptic flow converge to a unique mean v_2,PP elliptic flow in the participant plane and, with a Gaussian assumption on eccentricity fluctuations, can be converted to the mean v_2,RP in the reaction plane. Thus, the 20percent spread in observed elliptic flow measurements from different analysis methods is no longer mysterious.

  12. Elliptical instability of compressible flow in ellipsoids

    NASA Astrophysics Data System (ADS)

    Clausen, N.; Tilgner, A.

    2014-02-01

    Context. Elliptical instability is due to a parametric resonance of two inertial modes in a fluid velocity field with elliptical streamlines. This flow is a simple model of the motion in a tidally deformed, rotating body. Elliptical instability typically leads to three-dimensional turbulence. The associated turbulent dissipation together with the dissipation of the large scale mode may be important for the synchronization process in stellar and planetary binary systems. Aims: In order to determine the influence of the compressibility on the stability limits of tidal flows in stars or planets, we calculate the growth rates of perturbations in flows with elliptical streamlines within ellipsoidal boundaries of small ellipticity. In addition, the influence of the orbiting frequency of the tidal perturber ΩP and the viscosity of the fluid are taken into account. Methods: We studied the linear stability of the flow to determine the growth rates. We solved the Euler equation and the continuity equation. The viscosity was introduced heuristically in our calculations. We assumed a power law for the radial dependence of the background density. Together with the use of the anelastic approximation, this enabled us to use semi-analytical methods to solve the equations. Results: It is found that the growth rate of a certain mode combination depends on the compressibility. However, the influence of the compressibility is negligible for the growth rate maximized over all possible modes if viscous bulk damping effects can be neglected. The growth rate maximized over all possible modes determines the stability of the flow. The stability limit for the compressible fluid confined to an ellipsoid is the same as for incompressible fluid in an unbounded domain. Depending on the ratio ΩP/ΩF, with ΩF the spin rate of the central object in the frame of the rotating tidal perturber, certain pairs of modes resonate with each other. The size of the bulk damping term depends on the modes

  13. Flow around a helically twisted elliptic cylinder

    NASA Astrophysics Data System (ADS)

    Kim, Woojin; Lee, Jungil; Choi, Haecheon

    2016-05-01

    In the present study, we conduct unsteady three-dimensional simulations of flows around a helically twisted elliptic (HTE) cylinder at the Reynolds numbers of 100 and 3900, based on the free-stream velocity and square root of the product of the lengths of its major and minor axes. A parametric study is conducted for Re = 100 by varying the aspect ratio (AR) of the elliptic cross section and the helical spanwise wavelength (λ). Depending on the values of AR and λ, the flow in the wake contains the characteristic wavelengths of λ, 2λ, 6λ, or even longer than 60λ, showing a wide diversity of flows in the wake due to the shape change. The drag on the optimal (i.e., having lowest drag) HTE cylinder (AR = 1.3 and λ = 3.5d) is lower by 18% than that of the circular cylinder, and its lift fluctuations are zero owing to complete suppression of vortex shedding in the wake. This optimal HTE configuration reduces the drag by 23% for Re = 3900 where the wake is turbulent, showing that the HTE cylinder reduces the mean drag and lift fluctuations for both laminar and turbulent flows.

  14. Prospects of Elliptic Flow Studies at NICA/MPD

    NASA Astrophysics Data System (ADS)

    Geraksiev, Nikolay

    2016-01-01

    As a key observable, anisotropic flow presents a unique insight into heavy ion collision physics. The presented poster reveals the prospects of studying elliptic flow at the NICA/MPD facility through the UrQMD model. Here, results for the elliptic flow of simulated and reconstructed hadrons at the planned NICA energy range are presented.

  15. Reconfigurable Optical Spectra from Perturbations on Elliptical Whispering Gallery Resonances

    NASA Technical Reports Server (NTRS)

    Mohageg, Makan; Maleki, Lute

    2008-01-01

    Elastic strain, electrical bias, and localized geometric deformations were applied to elliptical whispering-gallery-mode resonators fabricated with lithium niobate. The resultant perturbation of the mode spectrum is highly dependant on the modal indices, resulting in a discretely reconfigurable optical spectrum. Breaking of the spatial degeneracy of the whispering-gallery modes due to perturbation is also observed.

  16. Reconfigurable optical spectra from perturbations on elliptical whispering gallery resonances.

    PubMed

    Mohageg, Makan; Maleki, Lute

    2008-02-01

    Elastic strain, electrical bias, and localized geometric deformations were applied to elliptical whispering-gallery-mode resonators fabricated with lithium niobate. The resultant perturbation of the mode spectrum is highly dependant on the modal indices, resulting in a discretely reconfigurable optical spectrum. Breaking of the spatial degeneracy of the whispering-gallery modes due to perturbation is also observed. PMID:18542283

  17. Event-by-Event Elliptic Flow Fluctuations from PHOBOS

    NASA Astrophysics Data System (ADS)

    Wosiek, B.; Alver, B.; Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Busza, W.; Carroll, A.; Chai, Z.; Chetluru, V.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Halliwell, C.; Hamblen, J.; Harnarine, I.; Hauer, M.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Khan, N.; Kulinich, P.; Kuo, C. M.; Li, W.; Lin, W. T.; Loizides, C.; Manly, S.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Reed, C.; Richardson, E.; Roland, C.; Roland, G.; Sagerer, J.; Seals, H.; Sedykh, I.; Smith, C. E.; Stankiewicz, M. A.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Szostak, A.; Tonjes, M. B.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Vaurynovich, S. S.; Verdier, R.; Veres, G. I.; Walters, P.; Wenger, E.; Willhelm, D.; Wolfs, F. L. H.; Woźniak, K.; Wyngaardt, S.; Wysłouch, B.

    2009-04-01

    Recently PHOBOS has focused on the study of fluctuations and correlations in particle production in heavy-ion collisions at the highest energies delivered by the Relativistic Heavy Ion Collider (RHIC). In this report, we present results on event-by-event elliptic flow fluctuations in (Au+Au) collisions at sqrt {sNN}=200 GeV. A data-driven method was used to estimate the dominant contribution from non-flow correlations. Over the broad range of collision centralities, the observed large elliptic flow fluctuations are in agreement with the fluctuations in the initial source eccentricity.

  18. Elliptic instability in a Rankine vortex with axial flow

    NASA Astrophysics Data System (ADS)

    Lacaze, Laurent; Birbaud, Anne-Laure; Le Dizès, Stéphane

    2005-01-01

    The elliptic instability of a Rankine vortex with axial flow subject to a weak strain field perpendicular to its axis is analyzed by asymptotic methods in the limit of small strain rate. General unstable modes associated with resonant Kelvin modes of arbitrary azimuthal wavenumbers are considered. Both the effects of axial flow and viscosity are analyzed in details.

  19. System Size, Energy, Pseudorapidity, and Centrality Dependence of Elliptic Flow

    NASA Astrophysics Data System (ADS)

    Alver, B.; Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Busza, W.; Carroll, A.; Chai, Z.; Chetluru, V.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Halliwell, C.; Hamblen, J.; Harnarine, I.; Hauer, M.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Khan, N.; Kulinich, P.; Kuo, C. M.; Li, W.; Lin, W. T.; Loizides, C.; Manly, S.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Reed, C.; Richardson, E.; Roland, C.; Roland, G.; Sagerer, J.; Seals, H.; Sedykh, I.; Smith, C. E.; Stankiewicz, M. A.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Szostak, A.; Tonjes, M. B.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Vaurynovich, S. S.; Verdier, R.; Veres, G. I.; Walters, P.; Wenger, E.; Willhelm, D.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wyngaardt, S.; Wysłouch, B.

    2007-06-01

    This Letter presents measurements of the elliptic flow of charged particles as a function of pseudorapidity and centrality from Cu-Cu collisions at 62.4 and 200 GeV using the PHOBOS detector at the Relativistic Heavy Ion Collider. The elliptic flow in Cu-Cu collisions is found to be significant even for the most central events. For comparison with the Au-Au results, it is found that the detailed way in which the collision geometry (eccentricity) is estimated is of critical importance when scaling out system-size effects. A new form of eccentricity, called the participant eccentricity, is introduced which yields a scaled elliptic flow in the Cu-Cu system that has the same relative magnitude and qualitative features as that in the Au-Au system.

  20. Elliptic flow in Au+Au collisions at RHIC

    NASA Astrophysics Data System (ADS)

    Vale, Carla M.; PHOBOS Collaboration; Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Decowski, M. P.; García, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Holynski, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Mignerey, A. C.; Ngyuen, M.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tang, J.-L.; Tonjes, M. B.; Trzupek, A.; van Nieuwenhuizen, G. J.; Verdier, R.; Veres, G.; Wolfs, F. L. H.; Wosiek, B.; Wozniak, K.; Wuosmaa, A. H.; Wyslouch, B.

    2005-04-01

    Elliptic flow is an interesting probe of the dynamical evolution of the dense system formed in the ultrarelativistic heavy ion collisions at the relativistic heavy ion collider (RHIC). The elliptic flow dependences on transverse momentum, centrality and pseudorapidity were measured using data collected by the PHOBOS detector, which offers a unique opportunity to study the azimuthal anisotropies of charged particles over a wide range of pseudorapidity. These measurements are presented, together with an overview of the analysis methods and a discussion of the results.

  1. Homogeneous turbulence subjected to mean flow with elliptic streamlines

    NASA Technical Reports Server (NTRS)

    Blaisdell, G. A.; Shariff, K.

    1994-01-01

    Direct numerical simulations are performed for homogeneous turbulence with a mean flow having elliptic streamlines. This flow combines the effects of rotation and strain on the turbulence. Qualitative comparisons are made with linear theory for cases with high Rossby number. The nonlinear transfer process is monitored using a generalized skewness. In general, rotation turns off the nonlinear cascade; however, for moderate ellipticities and rotation rates the nonlinear cascade is turned off and then reestablished. Turbulence statistics of interest in turbulence modeling are calculated, including full Reynolds stress budgets.

  2. Cooling Flow Spectra in Ginga Galaxy Clusters

    NASA Technical Reports Server (NTRS)

    White, Raymond E., III

    1997-01-01

    The primary focus of this research project has been a joint analysis of Ginga LAC and Einstein SSS X-ray spectra of the hot gas in galaxy clusters with cooling flows is reported. We studied four clusters (A496, A1795, A2142 & A2199) and found their central temperatures to be cooler than in the exterior, which is expected from their having cooling flows. More interestingly, we found central metal abundance enhancements in two of the clusters, A496 and A2142. We have been assessing whether the abundance gradients (or lack thereof) in intracluster gas is correlated with galaxy morphological gradients in the host clusters. In rich, dense galaxy clusters, elliptical and SO galaxies are generally found in the cluster cores, while spiral galaxies are found in the outskirts. If the metals observed in clusters came from proto-ellipticals and proto-S0s blowing winds, then the metal distribution in intracluster gas may still reflect the distribution of their former host galaxies. In a research project which was inspired by the success of the Ginga LAC/Einstein SSS work, we analyzed X-ray spectra from the HEAO-A2 MED and the Einstein SSS to look for temperature gradients in cluster gas. The HEAO-A2 MED was also a non-imaging detector with a large field of view compared to the SSS, so we used the differing fields of view of the two instruments to extract spatial information. We found some evidence of cool gas in the outskirts of clusters, which may indicate that the nominally isothermal mass density distributions in these clusters are steepening in the outer parts of these clusters.

  3. Two-dimensional subsonic compressible flow past elliptic cylinders

    NASA Technical Reports Server (NTRS)

    Kaplan, Carl

    1938-01-01

    The method of Poggi is used to calculate, for perfect fluids, the effect of compressibility upon the flow on the surface of an elliptic cylinder at zero angle of attack and with no circulation. The result is expressed in a closed form and represents a rigorous determination of the velocity of the fluid at the surface of the obstacle insofar as the second approximation is concerned. Comparison is made with Hooker's treatment of the same problem according to the method of Janzen and Rayleight and it is found that, for thick elliptic cylinders, the two methods agree very well. The labor of computation is considerably reduced by the present solution.

  4. Pressure algorithm for elliptic flow calculations with the PDF method

    NASA Technical Reports Server (NTRS)

    Anand, M. S.; Pope, S. B.; Mongia, H. C.

    1991-01-01

    An algorithm to determine the mean pressure field for elliptic flow calculations with the probability density function (PDF) method is developed and applied. The PDF method is a most promising approach for the computation of turbulent reacting flows. Previous computations of elliptic flows with the method were in conjunction with conventional finite volume based calculations that provided the mean pressure field. The algorithm developed and described here permits the mean pressure field to be determined within the PDF calculations. The PDF method incorporating the pressure algorithm is applied to the flow past a backward-facing step. The results are in good agreement with data for the reattachment length, mean velocities, and turbulence quantities including triple correlations.

  5. Symmetry energy from elliptic flow in 197Au + 197Au

    NASA Astrophysics Data System (ADS)

    Russotto, P.; Wu, P. Z.; Zoric, M.; Chartier, M.; Leifels, Y.; Lemmon, R. C.; Li, Q.; Łukasik, J.; Pagano, A.; Pawłowski, P.; Trautmann, W.

    2011-03-01

    The elliptic-flow ratio of neutrons with respect to protons or light complex particles in reactions of neutron-rich systems at relativistic energies is proposed as an observable sensitive to the strength of the symmetry term in the equation of state at supra-normal densities. The results obtained from the existing FOPI/LAND data for 197Au + 197Au collisions at 400 MeV/nucleon in comparison with the UrQMD model favor a moderately soft symmetry term with a density dependence of the potential term proportional to (ρ /ρ0) γ with γ = 0.9 ± 0.4.

  6. Examining the Necessity to Include Event-By-Event Fluctuations in Experimental Evaluations of Elliptical Flow

    SciTech Connect

    Andrade, R.; Grassi, F.; Hama, Y.; Kodama, T.; Socolowski, O. Jr.

    2006-11-17

    Elliptic flow at BNL RHIC is computed event by event with NeXSPheRIO. We show that when symmetry of the particle distribution in relation to the reaction plane is assumed, as usually done in the experimental extraction of elliptic flow, there is a disagreement between the true and reconstructed elliptic flows (15%-30% for {eta}=0, 30% for p{sub perpendicular}=0.5 GeV). We suggest a possible way to take into account the asymmetry and get good agreement between these elliptic flows.

  7. The development of a three-dimensional partially elliptic flow computer program for combustor research

    NASA Technical Reports Server (NTRS)

    Pan, Y. S.

    1978-01-01

    A three dimensional, partially elliptic, computer program was developed. Without requiring three dimensional computer storage locations for all flow variables, the partially elliptic program is capable of predicting three dimensional combustor flow fields with large downstream effects. The program requires only slight increase of computer storage over the parabolic flow program from which it was developed. A finite difference formulation for a three dimensional, fully elliptic, turbulent, reacting, flow field was derived. Because of the negligible diffusion effects in the main flow direction in a supersonic combustor, the set of finite-difference equations can be reduced to a partially elliptic form. Only the pressure field was governed by an elliptic equation and requires three dimensional storage; all other dependent variables are governed by parabolic equations. A numerical procedure which combines a marching integration scheme with an iterative scheme for solving the elliptic pressure was adopted.

  8. Ages and Metallicities of Elliptical Galaxies from Mid-Ultraviolet Spectra

    NASA Astrophysics Data System (ADS)

    Peterson, R. C.; Carney, B. W.; Dorman, B.; Landsman, W. B.; Green, E. M.; Liebert, J.; O'Connell, R. W.; Rood, R. T.; Schiavon, R. P.

    2003-12-01

    We describe our progress on our Hubble Treasury program, aimed at better determining the age and metallicity of old stellar systems. We are calculating mid-ultraviolet and optical spectra from first principles using individual stellar photospheric models, checking them against high-quality observational spectra of standard stars and clusters, and then combining them to match stellar clusters and elliptical galaxies between one and 20 Gyr old. Our first report (Peterson et al. 2003, ApJ, 588, 299) shows a half-dozen stellar spectra calculated at a metallicity one-third solar coadded in various combinations, and compared to the globular cluster G1 in the Andromeda galaxy (M31). The mid-UV reveals the presence of old hot horizontal branch stars. Currently we are generating composite spectra from weights derived from isochrones rather than empirically. The isochrones are created from stellar tracks we are computing for several elemental abundance ratios: scaled solar, oxygen-enhanced, and enhanced in the light elements Mg, Si, Ca, and Ti. We plot several composite spectra of about one-third solar metallicity and compare them to observed spectra, to illustrate their diagnostic potential for establishing the age, metallicity, and light-element abundance ratio.

  9. Directed and elliptic flow in 158GeV/Nucleon Pb+Pb collisions

    NASA Astrophysics Data System (ADS)

    Appelshäuser, H.; Bächler, J.; Bailey, S. J.; Barnby, L. S.; Bartke, J.; Barton, R. A.; Biał Kowska, H.; Blyth, C. O.; Bock, R.; Bormann, C.; Brady, F. P.; Brockmann, R.; Brun, R.; Bunč Ić , P.; Caines, H. L.; Cebra, D.; Cooper, G. E.; Cramer, J. G.; Csato, P.; Dunn, J.; Eckardt, V.; Eckhardt, F.; Ferguson, M. I.; Fischer, H. G.; Flierl, D.; Fodor, Z.; Foka, P.; Freund, P.; Friese, V.; Fuchs, M.; Gabler, F.; Gal, J.; Gaź Dzicki, M.; Gł Adysz, E.; Grebieszkow, J.; Günther, J.; Harris, J. W.; Hegyi, S.; Henkel, T.; Hill, L. A.; Huang, I.; Hümmler, H.; Igo, G.; Irmscher, D.; Jacobs, P.; Jones, P. G.; Kadija, K.; Kolesnikov, V. I.; Kowalski, M.; Lasiuk, B.; Lévai, P.; Malakhov, A. I.; Margetis, S.; Markert, C.; Melkumov, G. L.; Mock, A.; Molnár, J.; Nelson, J. M.; Oldenburg, M.; Odyniec, G.; Palla, G.; Panagiotou, A. D.; Petridis, A.; Piper, A.; Porter, R. J.; Poskanzer, A. M.; Poziombka, S.; Prindle, D. J.; Pühlhofer, F.; Rauch, W.; Reid, J. G.; Renfordt, R.; Retyk, W.; Ritter, H. G.; Röhrich, D.; Roland, C.; Roland, G.; Rudolph, H.; Rybicki, A.; Sandoval, A.; Sann, H.; Semenov, A. Yu.; Schäfer, E.; Schmischke, D.; Schmitz, N.; Schönfelder, S.; Seyboth, P.; Seyerlein, J.; Sikler, F.; Skrzypczak, E.; Squier, G. T. A.; Stock, R.; Ströbele, H.; Szentpetery, I.; Sziklai, J.; Toy, M.; Trainor, T. A.; Trentalange, S.; Ullrich, T.; Vassiliou, M.; Vesztergombi, G.; Voloshin, S.; Vranić , D.; Wang, F.; Weerasundara, D. D.; Wenig, S.; Whitten, C.; Wienold, T.; Wood, L.; Yates, T. A.; Zimanyi, J.; Zybert, R.

    1998-08-01

    The directed and elliptic flow of protons and charged pions has been observed from the semi-central collisions of a 158GeV/nucleon Pb beam with a Pb target. The rapidity and transverse momentum dependence of the flow has been measured. The directed flow of the pions is opposite to that of the protons at high rapidity but both exhibit negative flow at low pt. The elliptic flow of both is fairly independent of rapidity but rises with pt.

  10. Directed and Elliptic Flow in 158 GeV/Nucleon Pb+Pb Collisions

    NASA Astrophysics Data System (ADS)

    Appelshäuser, H.; Bächler, J.; Bailey, S. J.; Barnby, L. S.; Bartke, J.; Barton, R. A.; Bialkowska, H.; Blyth, C. O.; Bock, R.; Bormann, C.; Brady, F. P.; Brockmann, R.; Buncic, N.; Buncic, P.; Caines, H. L.; Cebra, D.; Cooper, G. E.; Cramer, J. G.; Csato, P.; Dunn, J.; Eckardt, V.; Eckhardt, F.; Ferguson, M. I.; Fischer, H. G.; Flierl, D.; Fodor, Z.; Foka, P.; Freund, P.; Friese, V.; Fuchs, M.; Gabler, F.; Gal, J.; Gazdzicki, M.; Gladysz, E.; Grebieszkow, J.; Günther, J.; Harris, J. W.; Hegyi, S.; Henkel, T.; Hill, L. A.; Huang, I.; Hümmler, H.; Igo, G.; Irmscher, D.; Jacobs, P.; Jones, P. G.; Kadija, K.; Kolesnikov, V. I.; Kowalski, M.; Lasiuk, B.; Levai, P.; Malakhov, A. I.; Margetis, S.; Markert, C.; Melkumov, G. L.; Mock, A.; Molnar, J.; Nelson, J. M.; Odyniec, G.; Palla, G.; Panagiotou, A. D.; Petridis, A.; Piper, A.; Porter, R. J.; Poskanzer, A. M.; Poziombka, S.; Prindle, D. J.; Pühlhofer, F.; Rauch, W.; Reid, J. G.; Renfordt, R.; Retyk, W.; Ritter, H. G.; Röhrich, D.; Roland, C.; Roland, G.; Rudolph, H.; Rybicki, A.; Sandoval, A.; Sann, H.; Semenov, A. Yu.; Schäfer, E.; Schmischke, D.; Schmitz, N.; Schönfelder, S.; Seyboth, P.; Seyerlein, J.; Sikler, F.; Skrzypczak, E.; Squier, G. T.; Stock, R.; Ströbele, H.; Szentpetery, I.; Sziklai, J.; Toy, M.; Trainor, T. A.; Trentalange, S.; Ullrich, T.; Vassiliou, M.; Vesztergombi, G.; Voloshin, S.; Vranic, D.; Wang, F.; Weerasundara, D. D.; Wenig, S.; Whitten, C.; Wienold, T.; Wood, L.; Yates, T. A.; Zimanyi, J.; Zybert, R.

    1998-05-01

    The directed and elliptic flow of protons and charged pions has been observed from the semicentral collisions of a 158 GeV/nucleon Pb beam with a Pb target. The rapidity and transverse momentum dependence of the flow has been measured. The directed flow of the pions is opposite to that of the protons but both exhibit negative flow at low pt. The elliptic flow of both is fairly independent of rapidity but rises with pt.

  11. Simulation and modeling of the elliptic streamline flow

    NASA Technical Reports Server (NTRS)

    Blaisdell, G. A.; Shariff, K.

    1996-01-01

    Direct numerical simulations are performed for the elliptic streamline flow, which is a homogeneous turbulent flow that combines the effects of solid body rotation and strain. Simulations are run over a range of parameters in order to determine the effect of changing rotation and strain separately. For early times the nonlinear cascade is suppressed, but then is re-established at later times. The growth rate of turbulent kinetic energy agrees at early times with the trends from linear theory, but at later times the flow seems to approach an asymptotic state that is independent of the ratio of mean flow rotation rate to strain rate. A comparison with standard Reynolds stress turbulence models is made. It is found that for strong rotation rates, the models predict decay of the turbulence, while the simulations show exponential growth. Close examination of the simulation results shows that they are affected by excessively low Reynolds numbers. Suggestions for reducing low Reynolds number effects in future simulations is given.

  12. Exposing the non-collectivity in elliptic flow

    SciTech Connect

    Liao, Jinfeng; Koch, Volker

    2009-02-13

    We show that backward-forward elliptic asymmetry correlations provide an experimentally accessible observable which distinguishes between collective and non-collective contributions to the observed elliptic asymmetry v2 in relativistic heavy ion collisions. The measurement of this observable will reveal the momentum scale at which collective expansion seizes and where the elliptic asymmetry is dominated by (semi)-hard processes. In addition, the knowledge of the actual magnitude of the collective component of the elliptic asymmetry will be essential for the extraction of the viscosity of the matter created in these collisions.

  13. Lateral Migration and Rotational Motion of Elliptic Particles in Planar Poiseuille Flow

    NASA Technical Reports Server (NTRS)

    Qi, Dewei; Luo, Li-Shi; Aravamuthan, Raja; Strieder, William; Bushnell, Dennis M. (Technical Monitor)

    2002-01-01

    Simulations of elliptic particulate suspensions in the planar Poiseuille flow are performed by using the lattice Boltzmann equation. Effects of the multi-particle on the lateral migration and rotational motion of both neutrally and non-neutrally buoyant elliptic particles are investigated. Low and intermediate total particle volume fraction f(sub a) = 13%, 15%, and 40% are considered in this work.

  14. Centrality dependence of multiplicity, transverse energy, and elliptic flow from hydrodynamics

    SciTech Connect

    Kolb, Peter F.; Heinz, Ulrich; Huovinen, Pasi; Eskola, Kari J.; Tuominen, Kimmo

    2001-03-21

    The centrality dependence of the charged multiplicity, transverse energy, and elliptic flow coefficient is studied in a hydrodynamic model, using a variety of different initializations which model the initial energy or entropy production process as a hard or soft process, respectively. While the charged multiplicity depends strongly on the chosen initialization, the p{sub T}-integrated elliptic flow for charged particles as a function of charged particle multiplicity and the p{sub T}-differential elliptic flow for charged particles in minimum bias events turn out to be almost independent of the initialization.

  15. Mass ordering of differential elliptic flow and its violation for {phi} mesons

    SciTech Connect

    Hirano, Tetsufumi; Heinz, Ulrich; Kharzeev, Dmitri; Lacey, Roy; Nara, Yasushi

    2008-04-15

    We simulate the dynamics of Au+Au collisions at the Relativistic Heavy Ion Collider (RHIC) with a hybrid model that treats the dense early quark-gluon plasma (QGP) stage macroscopically as an ideal fluid but models the dilute late hadron resonance gas (HG) microscopically using a hadronic cascade. By comparing with a pure hydrodynamic approach we identify effects of hadronic viscosity on the transverse momentum spectra and differential elliptic flow v{sub 2}(p{sub T}). We investigate the dynamical origins of the observed mass ordering of v{sub 2}(p{sub T}) for identified hadrons, focusing on dissipative effects during the late hadronic stage. Within our approach, we find that, at RHIC energies, much of the finally observed mass splitting is generated during the hadronic stage, due to buildup of additional radial flow. The {phi} meson, having a small interaction cross section, does not fully participate in this additional flow. As a result, it violates the mass-ordering pattern for v{sub 2}(p{sub T}) that is observed for other hadron species. We also show that the early decoupling of the {phi} meson from the hadronic rescattering dynamics leads to interesting and unambiguous features in the p{sub T} dependence of the nuclear suppression factor R{sub AA} and of the {phi}/p ratio.

  16. Effect of free surface on near-wake flow of elliptic cylinders with different aspect ratios

    NASA Astrophysics Data System (ADS)

    Lee, Sang Joon; Daichin, -

    2003-04-01

    The flow fields behind elliptic cylinders with different aspect ratios adjacent to a free surface were investigated experimentally in a circulating water channel. The elliptic cylinders tested in this study have same cross section area. For each elliptic cylinder, the experiments were carried out under different conditions by varying the submergence depth of the cylinder beneath the free surface. The flow fields were measured using a single-frame double-exposure PIV system. For each experimental condition, 350 instantaneous velocity fields were captured and ensemble-averaged to obtain the mean flow field information and spatial distribution of turbulent statistics. The near-wakes can be basically classified into three typical patterns, which are formation of Coanda effect, generation of substantial jet-like flow, and attachment of jet flow to the free surface. The general flow structures behind the elliptic cylinder are similar to previous results for a circular submerged near to a free surface. However, the wake width and the angle of downward deflection of the shear layer developed from the lower surface of the elliptic cylinder are smaller than those for the circular cylinder. These trends are enhance with increasing of the cylinder aspect ratios.

  17. Multifractal spectra in homogeneous shear flow

    NASA Technical Reports Server (NTRS)

    Deane, A. E.; Keefe, L. R.

    1988-01-01

    Employing numerical simulations of 3-D homogeneous shear flow, the associated multifractal spectra of the energy dissipation, scalar dissipation and vorticity fields were calculated. The results for (128) cubed simulations of this flow, and those obtained in recent experiments that analyzed 1- and 2-D intersections of atmospheric and laboratory flows, are in some agreement. A two-scale Cantor set model of the energy cascade process which describes the experimental results from 1-D intersections quite well, describes the 3-D results only marginally.

  18. NeXSPheRIO results on elliptic-flow fluctuations at RHIC

    SciTech Connect

    Hama, Y. Andrade, R. P. G.; Grassi, F.; Qian, W.-L.; Osada, T.; Aguiar, C. E.; Kodama, T.

    2008-09-15

    By using the NeXSPheRIO code, we study the elliptic-flow fluctuations in Au + Au collisions at 200 A GeV. It is shown that, by fixing the parameters of the model to correctly reproduce the charged pseudorapidity and the transverse-momentum distributions, reasonable agreement of with data is obtained, both as function of pseudorapidity as well as of transverse momentum, for charged particles. Our results on elliptic-flow fluctuations are in good agreement with the recently measured data on experiments.

  19. Elliptical flow in relativistic ion collisions at \\sqrt{s}= 200 GeV

    NASA Astrophysics Data System (ADS)

    Kahana, D. E.; Kahana, S. H.

    2008-07-01

    A consistent picture of the Au + Au and D + Au, \\sqrt{s}= 200 A GeV measurements at RHIC obtained with the PHENIX, STAR, PHOBOS and BRAHMS detectors including both the rapidity and transverse momentum spectra was previously developed with the simulation LUCIFER. The approach was modelled on the early production of a fluid of pre-hadrons after the completion of an initial phase of high-energy interactions. The formation of pre-hadrons is discussed here, in a perturbative QCD approach as advocated by Kopeliovich, Nemchik and Schmidt. In the second phase of LUCIFER, a considerably lower energy hadron-like cascade ensues. Since the dominant collisions occurring in this latter phase are meson-meson in character while the initial collisions are between baryons, i.e. both involve hadron-sized interaction cross-sections, there is good reason to suspect that the observed elliptical flow will be produced naturally, and this is indeed found to be the case.

  20. Radial Motions in Disk Stars: Ellipticity or Secular Flows?

    NASA Astrophysics Data System (ADS)

    López-Corredoira, M.; González-Fernández, C.

    2016-06-01

    Average stellar orbits of the Galactic disk may have some small intrinsic ellipticity which breaks the exact axisymmetry and there may also be some migration of stars inwards or outwards. Both phenomena can be detected through kinematic analyses. We use the red clump stars selected spectroscopically from the APO Galactic Evolution Experiment, with known distances and radial velocities, to measure the radial component of the Galactocentric velocities within 5 kpc < R < 16 kpc, | b| \\lt 5^\\circ , and within 20° from the Sun–Galactic center line. The average Galactocentric radial velocity is VR = (1.48 ± 0.35)[R(kpc) ‑ (8.8 ± 2.7)] km s‑1 outwards in the explored range, with a higher contribution from stars below the Galactic plane. Two possible explanations can be given for this result: (i) the mean orbit of the disk stars is intrinsically elliptical with a Galactocentric radial gradient of eccentricity around 0.01 kpc‑1 or (ii) there is a net secular expansion of the disk, in which stars within R ≈ 9–11 kpc are migrating to the region R ≳ 11 kpc at the rate of ∼2 M⊙ yr‑1, and stars with R ≲ 9 kpc are falling toward the center of the Galaxy. This migration ratio would be unattainable for a long time and should decelerate, otherwise the Galaxy would fade away in around 1 Gyr. At present, both hypotheses are speculative and one would need data on the Galactocentric radial velocities for other azimuths different to the center or anticenter in order to confirm one of the scenarios.

  1. Event-by-event hydrodynamics and elliptic flow from fluctuating initial states

    SciTech Connect

    Holopainen, H.; Eskola, K. J.; Niemi, H.

    2011-03-15

    We develop a framework for event-by-event ideal hydrodynamics to study the differential elliptic flow, which is measured at different centralities in Au + Au collisions at the Relativistic Heavy Ion Collider (RHIC). Fluctuating initial energy density profiles, which here are the event-by-event analogs of the wounded nucleon profiles, are created using a Monte Carlo Glauber model. Using the same event plane method for obtaining v{sub 2} as in the data analysis, we can reproduce both the measured centrality dependence and the p{sub T} shape of charged-particle elliptic flow up to p{sub T}{approx}2 GeV. We also consider the relation of elliptic flow to the initial-state eccentricity using different reference planes and discuss the correlation between the physical event plane and the initial participant plane. Our results demonstrate that event-by-event hydrodynamics with initial-state fluctuations must be accounted for before a meaningful lower limit for viscosity can be obtained from elliptic flow data.

  2. Numerical study of boundary layer transition in flowing film evaporation on horizontal elliptical cylinder

    NASA Astrophysics Data System (ADS)

    Asbik, M.; Ansari, O.; Zeghmati, B.

    2005-03-01

    A numerical study of the onset of longitudinal transition between turbulent and laminar regimes during the evaporation of a water film is presented. These water film streams along a horizontal elliptical tube under the simultaneous effects of gravity, pressure gradients, caused by the vapor flow and curvature, and viscous forces. At the interface of water vapor, the shear stress is supposed to be negligible. Outside the boundary layer, the vapor phase velocity is obtained from potential flow. In the analysis Von Karman’s turbulence model is used and the inertia and convection terms are retained. Transfers equations are discretised by using the implicit Keller method. The effects of an initial liquid flow rate per unit of length, Froude number, temperature difference between the wall and the liquid vapor interface and ellipticity on the transition position have been evaluated. The transition criterion has been given in term of the critical film Reynolds number (ReΓ)C.

  3. An elliptic calculation procedure for 3-D viscous flow

    NASA Astrophysics Data System (ADS)

    Moore, J. G.

    1985-05-01

    The computation of 3-D internal transonic flows by means of a 3-D Euler Code is discussed. A multidomain approach for time hyperbolic system is presented. This technique, based on the decomposition of the computational domain into several subdomains which may overlap one another, makes it possible to simplify some mesh generation problems and to fit discontinuities such as shocks and slip surfaces. A description of the 3-D Euler Code is given. The space discretization method and the treatment of boundary conditions are emphasized. Various applications of this code in turbomachinery are discussed.

  4. Understanding pseudorapidity dependence of elliptic flow in heavy-ion collisions using a transport model

    NASA Astrophysics Data System (ADS)

    Nasim, Md.; Esha, Roli; Huang, Huan Zhong

    2016-04-01

    A systematic study of the pseudorapidity dependence of elliptic flow parameter using transport models (e.g., a multiphase transport model, AMPT, and ultrarelativistic quantum molecular dynamics, UrQMD) has been presented. We have observed that while at mid-pseudorapidity the elliptic flow measured using the event-plane method differs significantly from that measured by actual reaction plane method, both the event-plane and reaction-plane methods give the same elliptic flow for far forward and backward pseudorapidity. This indicates that the magnitude of measured v2 around midrapidity strongly depends on the analysis method. Therefore, one should use the same procedure (as used in data analysis) in model calculations while comparing model results and experimental data. We find the shape of v2(η ) measured by the PHOBOS experiment is not reproduced by using actual v2 (i.e., measured with respect to the reaction plane) from AMPT and UrQMD models. The shape and magnitude of measured v2(η ) can be explained by the AMPT model with string-melting mode only if one uses the same procedure as used in data analysis. Magnitude of elliptic flow can be reproduced for all pseudorapidity range by taking the parton-parton interaction cross section to be 3 mb at √{sN N}=62.4 and 200 GeV. This implies that the partonic interactions are necessary to reproduce data at √{sN N}=62.4 and 200 GeV and the strength of partonic interactions at far forward and backward rapidity is as strong as at midrapidity. Both UrQMD and AMPT with default mode fail to explain the data.

  5. Constraining the high-density nuclear symmetry energy with the transverse-momentum-dependent elliptic flow

    NASA Astrophysics Data System (ADS)

    Wang, Yongjia; Guo, Chenchen; Li, Qingfeng; Zhang, Hongfei; Leifels, Y.; Trautmann, W.

    2014-04-01

    Within the newly updated version of the ultrarelativistic quantum molecular dynamics (UrQMD) model, the transverse-velocity dependence of the elliptic flow of free nucleons from Au197+Au197 collisions at the incident energy 400 MeV/nucleon is studied within different windows of the normalized c.m. rapidity y0. It is found that the elliptic flow difference v2n-v2p and ratio v2n/v2p of neutrons versus protons are sensitive to the density dependence of the symmetry energy, especially the ratio v2n/v2p at small transverse velocity in the intermediate rapidity intervals 0.4<|y0|<0.6. By comparing either transverse-momentum-dependent or integrated FOPI/LAND elliptic flow data of nucleons and hydrogen isotopes with calculations using various Skyrme interactions, all exhibiting similar values of isoscalar incompressibility but very different density dependences of the symmetry energy, a moderately soft to linear symmetry energy is extracted, in good agreement with previous UrQMD or Tübingen QMD model calculations but contrast with results obtained with π-/π+ yield ratios in the literature.

  6. Elliptic and triangular flow of heavy flavor in heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Nahrgang, Marlene; Aichelin, Jörg; Bass, Steffen; Gossiaux, Pol Bernard; Werner, Klaus

    2015-01-01

    We investigate the elliptic and the triangular flow of heavy mesons in ultrarelativistic heavy-ion collisions at the BNL Relativistic Heavy-Ion Collider and the CERN Large Hadron Collider (LHC) . The dynamics of heavy quarks is coupled to the locally thermalized and fluid dynamically evolving quark-gluon plasma. The elliptic flow of D mesons and the centrality dependence measured at the LHC is well reproduced for purely collisional and bremsstrahlung interactions. Due to the event-by-event fluctuating initial conditions from the EPOS2 model, the D meson triangular flow is predicted to be nonzero at √{s }=200 GeV and √{s }=2.76 TeV. We study the centrality dependence and quantify the contributions stemming from flow of the light bulk event and the hadronization process. The flow coefficients as responses to the initial eccentricities behave differently for heavy mesons than for light hadrons due to their inertia. Higher-order flow coefficients of heavy flavor become important in order to quantify the degree of thermalization.

  7. A Study of Two-Equation Turbulence Models on the Elliptic Streamline Flow

    NASA Technical Reports Server (NTRS)

    Blaisdell, Gregory A.; Qin, Jim H.; Shariff, Karim; Rai, Man Mohan (Technical Monitor)

    1995-01-01

    Several two-equation turbulence models are compared to data from direct numerical simulations (DNS) of the homogeneous elliptic streamline flow, which combines rotation and strain. The models considered include standard two-equation models and models with corrections for rotational effects. Most of the rotational corrections modify the dissipation rate equation to account for the reduced dissipation rate in rotating turbulent flows, however, the DNS data shows that the production term in the turbulent kinetic energy equation is not modeled correctly by these models. Nonlinear relations for the Reynolds stresses are considered as a means of modifying the production term. Implications for the modeling of turbulent vortices will be discussed.

  8. Local parametric instability near elliptic points in vortex flows under shear deformation.

    PubMed

    Koshel, Konstantin V; Ryzhov, Eugene A

    2016-08-01

    The dynamics of two point vortices embedded in an oscillatory external flow consisted of shear and rotational components is addressed. The region associated with steady-state elliptic points of the vortex motion is established to experience local parametric instability. The instability forces the point vortices with initial positions corresponding to the steady-state elliptic points to move in spiral-like divergent trajectories. This divergent motion continues until the nonlinear effects suppress their motion near the region associated with the steady-state separatrices. The local parametric instability is then demonstrated not to contribute considerably to enhancing the size of the chaotic motion regions. Instead, the size of the chaotic motion region mostly depends on overlaps of the nonlinear resonances emerging in the perturbed system. PMID:27586607

  9. Numerical simulation of vortical flow over an elliptical-body missile at high angles of attack

    NASA Technical Reports Server (NTRS)

    Newsome, R. N.; Adams, M. S.

    1986-01-01

    Numerical solutions to the Reynolds-averaged Navier-Stokes equations are given for the flow about an elliptical body missile (3:1 ellipse) at a Mach number of 2.5 and a unit Reynolds number of 6.56 x 10 to the 6th/m. At high angles of attack, the flow is dominated by large-scale free vortices which occur in the lee-side flow field due to crossflow boundary-layer separation. Emphasis is focused on the accurate prediction of the lee-side vortical flow. Solutions are presented for both symmetric and asymmetric (body rolled 45 deg) configurations at 10 deg and 20 deg angle of attack. The computed results are compared with experimental surface pressure coefficients and vapor-screen photographs. Excellent agreement is obtained in all cases.

  10. CONFIRMATION OF ENHANCED DWARF-SENSITIVE ABSORPTION FEATURES IN THE SPECTRA OF MASSIVE ELLIPTICAL GALAXIES: FURTHER EVIDENCE FOR A NON-UNIVERSAL INITIAL MASS FUNCTION

    SciTech Connect

    Van Dokkum, Pieter G.; Conroy, Charlie

    2011-07-01

    We recently found that massive cluster elliptical galaxies have strong Na I {lambda}8183, 8195 and FeH {lambda}9916 Wing-Ford band absorption, indicating the presence of a very large population of stars with masses {approx}< 0.3 M{sub sun}. Here we test this result by comparing the elliptical galaxy spectra to those of luminous globular clusters associated with M31. These globular clusters have similar metallicities, abundance ratios, and ages as massive elliptical galaxies but their low dynamical mass-to-light ratios rule out steep stellar initial mass functions (IMFs). From high-quality Keck spectra we find that the dwarf-sensitive absorption lines in globular clusters are significantly weaker than in elliptical galaxies and consistent with normal IMFs. The differences in the Na I and Wing-Ford indices are 0.027 {+-} 0.007 mag and 0.017 {+-} 0.006 mag, respectively. We directly compare the two classes of objects by subtracting the averaged globular cluster spectrum from the averaged elliptical galaxy spectrum. The difference spectrum is well fit by the difference between a stellar population synthesis model with a bottom-heavy IMF and one with a bottom-light IMF. We speculate that the slope of the IMF may vary with velocity dispersion, although it is not yet clear what physical mechanism would be responsible for such a relation.

  11. Integrated Ultraviolet Spectra and Line Indices of M31 Globular Clusters and the Cores of Elliptical Galaxies

    NASA Astrophysics Data System (ADS)

    Ponder, Jerry M.; Burstein, David; O'Connell, Robert W.; Rose, James A.; Frogel, Jay A.; Wu, Chi-Chao; Crenshaw, D. Michael; Rieke, Marcia J.; Tripicco, Michael

    1998-11-01

    We present observations of the integrated light of four M31 globular clusters (MIV, MII, K280, and K58) and of the cores of six elliptical galaxies (NGC 3605, 3608, 5018, 5831, 6127, and 7619) made with the Faint Object Spectrograph on the Hubble Space Telescope. The spectra cover the range 2200-4800 Å at a resolution of 8 Å with signal-to-noise ratio of more than 20 and flux accuracy of ~5%. To these data we add from the literature IUE observations of the dwarf elliptical galaxy M32, Galactic globular clusters, and Galactic stars. The stellar populations in these systems are analyzed with the aid of mid-UV and near-UV colors and absorption line strengths. Included in the measured indices is the key NH feature at 3360 Å. We compare these line index measures with the 2600 - 3000 colors of these stars and stellar populations. We find that the M31 globular clusters, Galactic globular clusters/Galactic stars, and elliptical galaxies represent three distinct stellar populations, based on their behavior in color-line strength correlations involving Mg II, NH, CN, and several UV metallic blends. In particular, the M31 globular cluster MIV, as metal-poor as the Galactic globular M92, shows a strong NH 3360 Å feature. Other line indices, including the 3096 Å blend that is dominated by lines of Mg I and Al I, show intrinsic differences as well. We also find that the broadband line indices often employed to measure stellar population differences in faint objects, such as the 4000 Å and the Mg 2800 breaks, are disappointingly insensitive to these stellar population differences. We find that the hot (T > 20,000 K) stellar component responsible for the ``UV upturn'' at shorter wavelengths can have an important influence on the mid-UV spectral range (2400-3200 Å) as well. The hot component can contribute over 50% of the flux at 2600 Å in some cases and affects both continuum colors and line strengths. Mid-UV spectra of galaxies must be corrected for this effect before

  12. Importance of Granular Structure in the Initial Conditions for the Elliptic Flow

    SciTech Connect

    Andrade, R. P. G.; Grassi, F.; Hama, Y.; Qian, W. L.; Kodama, T.

    2008-09-12

    We show the effects of the granular structure of the initial conditions of a hydrodynamic description of high-energy nucleus-nucleus collisions on some observables, especially on the elliptic-flow parameter v{sub 2}. Such a structure enhances production of isotropically distributed high-p{sub T} particles, making v{sub 2} smaller there. Also, it reduces v{sub 2} in the forward and backward regions where the global matter density is smaller and, therefore, where such effects become more efficacious.

  13. Constraints provided by star cluster spectra on the nature of the UV turn-up in giant elliptical galaxies

    NASA Astrophysics Data System (ADS)

    Bica, E.; Alloin, D.

    1988-03-01

    We have linked available ultraviolet observations to the visible and near infrared spectra of some objects from our star cluster and galaxy nucleus samples. We have analyzed the nature of the UV turn-up in giant elliptical galaxies (gE) in the light of our recent population synthesis results which are based upon a library of star cluster integrated spectra in the visible and near infrared. We also investigate how star clusters can provide information on the frequency of occurrence of particular types of stars with respect to the associated populations of a given age and metallicity. We definitely exclude the possibility that the UV turn-up in gE is caused by blue horizontal branch (BHB) stars associated with metal-poor components: even if they were a major contributor to the optical spectrum, their UV turn-up would be unable to account for that observed in gE, simply because it is not steep enough. Furthermore, our previous visible-near infrared synthesis has shown that only 10% of the flux originates from low metallicity components. On the contrary we find strong evidence that this UV turn-up is a result of on-going star formation in gE nuclei. Indeed, young blue clusters and/or H II region spectra match the UV turn-up quite well, without affecting much the optical range where their contribution is less than 2% at 5870 Å. Another possibility would be that the UV turn-up in gE is caused by post AGB stars from metal-rich components: data presently available about their frequency of occurrence in metal-rich galactic clusters, as well as about that of planetary nebulae in the bulge of M31 do not favour this interpretation however.

  14. Flow and Thermal Performance of a Water-Cooled Periodic Transversal Elliptical Microchannel Heat Sink for Chip Cooling.

    PubMed

    Wei, Bo; Yang, Mo; Wang, Zhiyun; Xu, Hongtao; Zhang, Yuwen

    2015-04-01

    Flow and thermal performance of transversal elliptical microchannels were investigated as a passive scheme to enhance the heat transfer performance of laminar fluid flow. The periodic transversal elliptical micro-channel is designed and its pressure drop and heat transfer characteristics in laminar flow are numerically investigated. Based on the comparison with a conventional straight micro- channel having rectangular cross section, it is found that periodic transversal elliptical microchannel not only has great potential to reduce pressure drop but also dramatically enhances heat transfer performance. In addition, when the Reynolds number equals to 192, the pressure drop of the transversal elliptical channel is 36.5% lower than that of the straight channel, while the average Nusselt number is 72.8% higher; this indicates that the overall thermal performance of the periodic transversal elliptical microchannel is superior to the conventional straight microchannel. It is suggested that such transversal elliptical microchannel are attractive candidates for cooling future electronic chips effectively with much lower pressure drop. PMID:26353536

  15. Near-wake flow structure of elliptic cylinders close to a free surface: effect of cylinder aspect ratio

    NASA Astrophysics Data System (ADS)

    Daichin, K. V.; Lee, Sang Joon

    The flow fields behind elliptic cylinders adjacent to a free surface were investigated experimentally in a circulating water channel. A range of cylinder aspect ratios (AR=2, 3, 4) were considered, while the cross-sectional area of the elliptical cylinder was kept constant. The main objective of this study was to investigate the effect of cylinder aspect ratio and a free surface on the flow structure in the near-wake behind elliptic cylinders. For each elliptic cylinder, the flow structure was analyzed for various values of the submergence depth of the cylinder beneath the free surface. The flow fields were measured using a single-frame double-exposure PIV (Particle Image Velocimetry) system. For each experimental condition, 350 instantaneous velocity fields were obtained and ensemble-averaged to obtain the mean velocity field and spatial distribution of the mean vorticity statistics. The results show that near-wake can be classified into three typical flow patterns: formation of a Coanda flow, generation of substantial jet-like flow, and attachment of this jet flow to the free surface. The general flow structure observed behind the elliptic cylinders resembles the structure previously reported for a circular cylinder submerged near a free surface. However, the wake width and the angle of downward deflection of the shear layer developed from the lower surface of the elliptic cylinder differ from those observed for a circular cylinder. These trends are enhanced as cylinder aspect ratio is increased. In addition, the free surface distortion is also discussed in the paper.

  16. Numerical analysis of blood flow through an elliptic stenosis using large eddy simulation.

    PubMed

    Jabir, E; Lal, S Anil

    2016-08-01

    The presence of a stenosis caused by the abnormal narrowing of the lumen in the artery tree can cause significant variations in flow parameters of blood. The original flow, which is believed to be laminar in most situations, may turn out to turbulent by the geometric perturbation created by the stenosis. Flow may evolve to fully turbulent or it may relaminarise back according to the intensity of the perturbation. This article reports the numerical simulation of flow through an eccentrically located asymmetric stenosis having elliptical cross section using computational fluid dynamics. Large eddy simulation technique using dynamic Smagorinsky sub-grid scale model is applied to capture the turbulent features of flow. Analysis is carried out for two situations: steady inflow as ideal condition and pulsatile inflow corresponding to the actual physiological condition in common carotid artery. The spatially varying pulsatile inflow waveforms are mathematically derived from instantaneous mass flow measurements available in the literature. Carreau viscosity model is used to estimate the effect of non-Newtonian nature of blood. The present simulations for steady and pulsatile conditions show that post-stenotic flow field undergoes transition to turbulence in all cases. The characteristics of mean and turbulent flow fields have been presented and discussed in detail. PMID:27146288

  17. Optimization of an inclined elliptic impinging jet with cross flow for enhancing heat transfer

    NASA Astrophysics Data System (ADS)

    Heo, Man-Woong; Lee, Ki-Don; Kim, Kwang-Yong

    2011-06-01

    This work presents a parametric study and optimization of a single impinging jet with cross flow to enhance heat transfer with two design variables. The fluid flow and heat transfer have been analyzed using three-dimensional compressible Reynolds-averaged Navier-Stokes equations with a uniform heat flux condition being applied to the impingement plate. The aspect ratio of the elliptic jet hole and the angle of inclination of the jet nozzle are chosen as the two design variables, and the area-averaged Nusselt number on a limited target plate is set as the objective function. The effects of the design variables on the heat transfer performance have been evaluated, and the objective function has been found to be more sensitive to the angle of inclination of the jet nozzle than to the aspect ratio of the elliptic jet hole. The optimization has been performed by using the radial basis neural network model. Through the optimization, the area-averaged Nusselt number increased by 7.89% compared to that under the reference geometry.

  18. Elliptic flow of identified hadrons in Pb-Pb collisions at TeV

    NASA Astrophysics Data System (ADS)

    Abelev, B.; Adam, J.; Adamová, D.; Aggarwal, M. M.; Agnello, M.; Agostinelli, A.; Agrawal, N.; Ahammed, Z.; Ahmad, N.; Ahmed, I.; Ahn, S. U.; Ahn, S. A.; Aimo, I.; Aiola, S.; Ajaz, M.; Akindinov, A.; Alam, S. N.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Alici, A.; Alkin, A.; Alme, J.; Alt, T.; Altinpinar, S.; Altsybeev, I.; Alves Garcia Prado, C.; Andrei, C.; Andronic, A.; Anguelov, V.; Anielski, J.; Antičić, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Arcelli, S.; Armesto, N.; Arnaldi, R.; Aronsson, T.; Arsene, I. C.; Arslandok, M.; Augustinus, A.; Averbeck, R.; Awes, T. C.; Azmi, M. D.; Bach, M.; Badalà, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bala, R.; Baldisseri, A.; Baltasar Dos Santos Pedrosa, F.; Baral, R. C.; Barbera, R.; Barile, F.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartke, J.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Batista Camejo, A.; Batyunya, B.; Batzing, P. C.; Baumann, C.; Bearden, I. G.; Beck, H.; Bedda, C.; Behera, N. K.; Belikov, I.; Bellini, F.; Bellwied, R.; Belmont-Moreno, E.; Belmont, R.; Belyaev, V.; Bencedi, G.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Berger, M. E.; Bertens, R. A.; Berzano, D.; Betev, L.; Bhasin, A.; Bhat, I. R.; Bhati, A. K.; Bhattacharjee, B.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Bjelogrlic, S.; Blanco, F.; Blau, D.; Blume, C.; Bock, F.; Bogdanov, A.; Bøggild, H.; Bogolyubsky, M.; Böhmer, F. V.; Boldizsár, L.; Bombara, M.; Book, J.; Borel, H.; Borissov, A.; Bossú, F.; Botje, M.; Botta, E.; Böttger, S.; Braun-Munzinger, P.; Bregant, M.; Breitner, T.; Broker, T. A.; Browning, T. A.; Broz, M.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buncic, P.; Busch, O.; Buthelezi, Z.; Caffarri, D.; Cai, X.; Caines, H.; Calero Diaz, L.; Caliva, A.; Calvo Villar, E.; Camerini, P.; Carena, F.; Carena, W.; Castillo Castellanos, J.; Casula, E. A. R.; Catanescu, V.; Cavicchioli, C.; Ceballos Sanchez, C.; Cepila, J.; Cerello, P.; Chang, B.; Chapeland, S.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Chelnokov, V.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chibante Barroso, V.; Chinellato, D. D.; Chochula, P.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Colocci, M.; Conesa Balbastre, G.; Conesa del Valle, Z.; Connors, M. E.; Contreras, J. G.; Cormier, T. M.; Corrales Morales, Y.; Cortese, P.; Cortés Maldonado, I.; Cosentino, M. R.; Costa, F.; Crochet, P.; Cruz Albino, R.; Cuautle, E.; Cunqueiro, L.; Dainese, A.; Dang, R.; Danu, A.; Das, D.; Das, I.; Das, K.; Das, S.; Dash, A.; Dash, S.; De, S.; Delagrange, H.; Deloff, A.; Dénes, E.; D'Erasmo, G.; De Caro, A.; de Cataldo, G.; de Cuveland, J.; De Falco, A.; De Gruttola, D.; De Marco, N.; De Pasquale, S.; de Rooij, R.; Diaz Corchero, M. A.; Dietel, T.; Dillenseger, P.; Divià, R.; Di Bari, D.; Di Liberto, S.; Di Mauro, A.; Di Nezza, P.; Djuvsland, Ø.; Dobrin, A.; Dobrowolski, T.; Domenicis Gimenez, D.; Dönigus, B.; Dordic, O.; Dørheim, S.; Dubey, A. K.; Dubla, A.; Ducroux, L.; Dupieux, P.; Dutta Majumdar, A. K.; Hilden, T. E.; Ehlers, R. J.; Elia, D.; Engel, H.; Erazmus, B.; Erdal, H. A.; Eschweiler, D.; Espagnon, B.; Esposito, M.; Estienne, M.; Esumi, S.; Evans, D.; Evdokimov, S.; Fabris, D.; Faivre, J.; Falchieri, D.; Fantoni, A.; Fasel, M.; Fehlker, D.; Feldkamp, L.; Felea, D.; Feliciello, A.; Feofilov, G.; Ferencei, J.; Fernández Téllez, A.; Ferreiro, E. G.; Ferretti, A.; Festanti, A.; Figiel, J.; Figueredo, M. A. S.; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Floratos, E.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; Frankenfeld, U.; Fuchs, U.; Furget, C.; Fusco Girard, M.; Gaardhøje, J. J.; Gagliardi, M.; Gago, A. M.; Gallio, M.; Gangadharan, D. R.; Ganoti, P.; Garabatos, C.; Garcia-Solis, E.; Gargiulo, C.; Garishvili, I.; Gerhard, J.; Germain, M.; Gheata, A.; Gheata, M.; Ghidini, B.; Ghosh, P.; Ghosh, S. K.; Gianotti, P.; Giubellino, P.; Gladysz-Dziadus, E.; Glässel, P.; Gomez Ramirez, A.; González-Zamora, P.; Gorbunov, S.; Görlich, L.; Gotovac, S.; Graczykowski, L. K.; Grelli, A.; Grigoras, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Grosse-Oetringhaus, J. F.; Grossiord, J.-Y.; Grosso, R.; Guber, F.; Guernane, R.; Guerzoni, B.; Guilbaud, M.; Gulbrandsen, K.; Gulkanyan, H.; Gumbo, M.; Gunji, T.; Gupta, A.; Gupta, R.; Khan, K. H.; Haake, R.; Haaland, Ø.; Hadjidakis, C.; Haiduc, M.; Hamagaki, H.; Hamar, G.; Hanratty, L. D.; Hansen, A.; Harris, J. W.

    2015-06-01

    The elliptic flow coefficient ( v 2) of identified particles in Pb-Pb collisions at TeV was measured with the ALICE detector at the Large Hadron Collider (LHC). The results were obtained with the Scalar Product method, a two-particle correlation technique, using a pseudo-rapidity gap of |Δ η| > 0 .9 between the identified hadron under study and the reference particles. The v 2 is reported for π ±, K±, K{S/0}, , ϕ, , and in several collision centralities. In the low transverse momentum ( p T) region, p T < 3 GeV/ c, v 2( p T) exhibits a particle mass dependence consistent with elliptic flow accompanied by the transverse radial expansion of the system with a common velocity field. The experimental data for π ± and the combined K± and K{S/0} results, are described fairly well by hydrodynamic calculations coupled to a hadronic cascade model (VISHNU) for central collisions. However, the same calculations fail to reproduce the v 2( p T) for , ϕ, and . For transverse momentum values larger than about 3 GeV/ c, particles tend to group according to their type, i.e. mesons and baryons. The present measurements exhibit deviations from the number of constituent quark (NCQ) scaling at the level of ±20% for p T > 3 GeV/ c. [Figure not available: see fulltext.

  19. Elliptic flow and shear viscosity of the shattered color glass condensate

    NASA Astrophysics Data System (ADS)

    Ruggieri, Marco; Scardina, Francesco; Plumari, Salvatore; Greco, Vincenzo

    2014-07-01

    In this contribution, we report on our results about the computation of the elliptic flow of the quark-gluon-plasma produced in relativistic heavy ion collisions, simulating the expansion of the fireball by solving the relativistic Boltzmann equation for the parton distribution function tuned at a fixed shear viscosity to entropy density ratio η/s. We emphasize the role of saturation in the initial gluon spectrum modelling the shattering of the color glass condensate, causing the initial distribution to be out of equilibrium. We find that the saturation reduces the efficiency in building-up the elliptic flow, even if the thermalization process is quite fast τtherm ≈ 0.8fm/c. and the pressure isotropization even faster τisotr ≈ 0.3fm/c. The impact of the initial non-equilibrium manifests for non-central collisions and can modify the estimate of the viscosity respect to the assumption of full thermalization in pT-space.

  20. Elliptic and triangular flow of identified particles from the AMPT model at RHIC energies

    NASA Astrophysics Data System (ADS)

    Sun, Xu; Liu, Jianli; Schmah, Alexander; Shi, Shusu; Zhang, Jingbo; Jiang, Hanzhi; Huo, Lei

    2015-11-01

    The elliptic flow (v2) at \\sqrt{{s}{NN}} = 11.5, 39 and 200 GeV and triangular flow (v3) at \\sqrt{{s}{NN}} = 200 GeV of identified particles ({π }+/- ,{K}+/- ,{K}S0,p,\\bar{p},φ ,{{Λ }} and \\bar{{{Λ }}}) from 0-80% central Au+Au collisions are analyzed using a multiphase transport (AMPT) model. It is shown that the experimental results from the η-sub event plane method can be reproduced with a parton scattering cross-section between 1.5 and 3 mb. We also studied the differential and integrated {v}2/{v}3 ratios and conclude that they are anti-correlated with the parton scattering cross-section.

  1. Viscous flow computations for elliptical two-duct version of the SSME hot gas manifold

    NASA Technical Reports Server (NTRS)

    Roger, R. P.

    1986-01-01

    The objective of the effort was to numerically simulate viscous subsonic flow in a proposed elliptical two-duct version of the fuel side Hot Gas Manifold (HGM) for the Space Shuttle Main Engine (SSME). The numerical results were to complement both water flow and air flow experiments in the two-duct geometry performed at NASA-MSFC and Rocketdyne. The three-dimensional character of the HGM consists of two essentially different geometries. The first part of the construction is a concentric shell duct structure which channels the gases from a turbine exit into the second part comprised of two cylindrically shaped transfer ducts. The initial concentric shell portion can be further subdivided into a turnaround section and a bowl section. The turnaround duct (TAD) changes the direction of the mean flow by 180 degress from a smaller radius to a larger radius duct which discharges into the bowl. The cylindrical transfer ducts are attached to the bowl on one side thus providing a plane of symmetry midway between the two. Centerline flow distance from the TAD inlet to the transfer duct exit is approximately two feet. Details of the approach used to numerically simulate laminar or turbulent flow in the HGM geometry are presented. Computational results are presented and discussed.

  2. Computer program for calculating supersonic flow about circular, elliptic, and bielliptic cones by the method of lines

    NASA Technical Reports Server (NTRS)

    Klunker, E. B.; South, J. C., Jr.; Davis, R. M.

    1972-01-01

    A user's manual for a computer program which calculates the supersonic flow about circular, elliptic, and bielliptic cones at incidence and elliptic cones at yaw by the method of lines is presented. The program is automated to compute a case from known or easily calculated solution by changing the parameters through a sequence of steps. It provides information including the shock shape, flow field, isentropic surface properties, entropy layer, and force coefficients. A description of the program operation, sample computations, and a FORTRAN 4 listing are presented.

  3. Elliptic flow due to charged hadrons for Au+Au collisions at RHIC energy 62.4 GeV

    NASA Astrophysics Data System (ADS)

    Kumar, Somani Ajit; Sudhir, Bhardwaj; Ashish, Agnihotri

    2016-05-01

    Elliptic flow is an important observable in search of Quark Gluon Plasma. The elliptic flow parameter dependence on centrality due to charged hadrons were studied using events generated by event generator AMPT at center of mass energy of 62.4 GeV per nucleon pair for Au+Au collisions. This study performed for pseudorapidity range from -0.35 to 0.35 and transverse momentum bins pt = 0.2 to 1 GeV/c and 1 to 2 GeV/c. We compared the results obtained from simulated data and RHIC-PHENIX data.

  4. A flow cytometer for the measurement of Raman spectra.

    PubMed

    Watson, Dakota A; Brown, Leif O; Gaskill, Daniel F; Naivar, Mark; Graves, Steven W; Doorn, Stephen K; Nolan, John P

    2008-02-01

    Multiparameter measurements in flow cytometry are limited by the broad emission spectra of fluorescent labels. By contrast, Raman spectra are notable for their narrow spectral features. To increase the multiparameter analysis capabilities of flow cytometry, we investigated the possibility of measuring Raman signals in a flow cytometry-based system. We constructed a Raman Spectral Flow Cytometer, substituting a spectrograph and CCD detector for the traditional mirrors, optical filters, and photomultiplier tubes. Excitation at 633 nm was provided by a HeNe laser, and forward-angle light scatter is used to trigger acquisition of complete spectra from individual particles. Microspheres were labeled with nanoparticle surface enhanced Raman scattering (SERS) tags and measured using the RSFC. Fluorescence and Raman spectra from labeled microspheres were acquired using the Raman Spectral Flow Cytometer. SERS spectral intensities were dependent on integration time, laser power, and detector pixel binning. Spectra from particles labeled with one each of four different SERS tags could be distinguished by either a virtual bandpass approach using commercial flow cytometry data analysis software or by principal component analysis. Raman flow cytometry opens up new possibilities for highly multiparameter and multiplexed measurements of cells and other particles using a simple optical design and a single detector and light source. PMID:18189283

  5. Elliptic flow of identified particles in Pb-Pb collisions at the LHC

    NASA Astrophysics Data System (ADS)

    Dobrin, A.

    2014-11-01

    The elliptic flow coefficient, v2, is presented for π±, K±, KS0,p +pbar, ϕ, Λ +Λbar, Ξ- +Ξbar+, Ω- +Ωbar+ in Pb-Pb collisions at √{sNN} = 2.76 TeV with the ALICE detector. Results obtained with the scalar product method are reported as a function of transverse momentum, pT, out to pT = 6 GeV / c at different collision centralities. For pT < 2 GeV / c, v2 exhibits a particle mass dependence. Particles tend to group into mesons and baryons for pT > 3 GeV / c. Deviations from the number of constituent quark scaling at the level of ± 20% are found for pT > 2- 3 GeV / c. The results are compared to hydrodynamic calculations coupled to a hadronic cascade model.

  6. Systematic study of elliptic flow parameter in the relativistic nuclear collisions at RHIC and LHC energies

    NASA Astrophysics Data System (ADS)

    Sa, Ben-Hao; Zhou, Dai-Mei; Yan, Yu-Liang; Cheng, Yun; Dong, Bao-Guo; Cai, Xu

    2014-04-01

    We employed the new issue of a parton and hadron cascade model PACIAE 2.1 to systematically investigate the charged particle elliptic flow parameter v2 in the relativistic nuclear collisions at RHIC and LHC energies. With randomly sampling the transverse momentum x and y components of the particles generated in string fragmentation on the circumference of an ellipse instead of circle as originally, the calculated charged particles v2(η) and v2(pT) fairly reproduce the corresponding experimental data in the Au+Au/Pb+Pb collisions at √{sNN}=0.2/2.76 TeV. In addition, the charged particles v2(η) and v2(pT) in the p+p collisions at √{s}=7 TeV as well as in the p+Au/p+Pb collisions at √{sNN}=0.2/5.02 TeV are predicted.

  7. Mixed convection boundary layer flow over a horizontal elliptic cylinder with constant heat flux

    NASA Astrophysics Data System (ADS)

    Javed, Tariq; Ahmad, Hussain; Ghaffari, Abuzar

    2015-12-01

    Mixed convection boundary layer flow of a viscous fluid over a horizontal elliptic cylinder with a constant heat flux is investigated numerically. The governing partial differential equations are transformed to non-dimensional form and then are solved by an efficient implicit finite different scheme known as Keller-box method. The solutions are expressed in the form of skin friction and Nusselt number, which are plotted against the eccentric angle. The effect of pertinent parameters such as mixed convection parameter, aspect ratio (ratio of lengths of minor axis to major axis), and Prandtl number on skin friction and Nusselt number are illustrated through graphs for both blunt and slender orientations. The increase in the value of mixed convection parameter results in increase in skin friction coefficient and Nusselt number for blunt as well as slender orientations.

  8. Eccentricity fluctuation effects on elliptic flow in relativistic heavy ion collisions

    SciTech Connect

    Hirano, Tetsufumi; Nara, Yasushi

    2009-06-15

    We study effects of eccentricity fluctuations on the elliptic flow coefficient v{sub 2} at midrapidity in both Au+Au and Cu+Cu collisions at {radical}(s{sub NN})=200 GeV by using a hybrid model that combines ideal hydrodynamics for space-time evolution of the quark gluon plasma phase and a hadronic transport model for the hadronic matter. For initial conditions in hydrodynamic simulations, both the Glauber model and the color glass condensate model are employed to demonstrate the effect of initial eccentricity fluctuations originating from the nucleon position inside a colliding nucleus. The effect of eccentricity fluctuations is modest in semicentral Au+Au collisions, but significantly enhances v{sub 2} in Cu+Cu collisions.

  9. Effect of bulk viscosity on elliptic flow near the QCD phase transition

    SciTech Connect

    Denicol, G. S.; Kodama, T.; Mota, Ph.; Koide, T.

    2009-12-15

    In this work, we examine the effect of bulk viscosity on elliptic flow, taking into account the critical behavior of the equation of state and transport coefficients near the QCD phase transition. We found that the p{sub T} dependence of v{sub 2} is quantitatively changed by the presence of the QCD phase transition. Within reasonable values of the transport coefficients, v{sub 2} decreases by a factor of 15% at small p{sub T} values (<1 GeV). However, for larger values of p{sub T} (>2 GeV), the interplay between the velocity of sound and transport coefficient near the QCD phase transition enhances v{sub 2}. We point out that Grad's 14-moment approximation cannot be applied for the calculation of the one-particle distribution function at the freeze-out.

  10. Onset of laminar separation and vortex shedding in flow past unconfined elliptic cylinders

    NASA Astrophysics Data System (ADS)

    Paul, Immanuvel; Prakash, K. Arul; Vengadesan, S.

    2014-02-01

    This article presents the numerical studies on predicting onset of flow separation and vortex shedding in flow past unconfined two-dimensional elliptical cylinders for various Axis Ratios (AR) and a wide range of Angles of Attack (AOA). An efficient Cartesian grid technique based immersed boundary method is used for numerical simulations. The laminar separation Reynolds number (Res) that marks separation of flow from surface and the critical Reynolds number (Recr) which represents transition from steady to unsteady flow are determined using diverse methods. A stability analysis which uses Stuart-Landau equation is also performed for calculating Recr. The shedding frequency (Stcr) that corresponds to Recr is calculated using Landau constants. The simulated results for circular cylinder are found to be in good agreement with the literature. The effects of AR and AOA on Res, Recr, and Stcr are studied. It is observed that the Res, Recr, and Stcr exhibit a direct/inverse relationship with AR depending upon the given AOA. Correlations of Res, Recr, and Stcr with respect to AR and AOA are proposed with good accuracy.

  11. Sedimentation of an elliptical particle in periodic oscillatory pressure driven flow

    NASA Astrophysics Data System (ADS)

    Yuan, Wenjun; Deng, Jianqiang; Cao, Zheng; Mei, Mei

    2015-12-01

    The sedimentation of a heavy elliptical particle in a two-dimensional channel filled with Newtonian fluid under oscillatory pressure driven flow has been numerically investigated by using the finite element arbitrary Lagrangian-Eulerian method. The effects of particle Reynolds number, initial position, blockage ratio, as well as oscillation frequency and amplitude on the flow patterns during sedimentation have been studied. The results show that there exists an equilibrium position for high frequency flow, and the position of the heavier particle is closer to the centerline. As rotation contributes to non-uniform pressure on particle surface, the further initial position and lower amplitude lead to the larger scale zigzag migration; however, the maximum lateral displacements of these low frequency zigzag motions are nearly the same due to the consistent lubrication limit. Moreover, our simulation results indicate that there are five distinct modes of settling in oscillatory flow: horizontal with offset, oscillating, tumbling throughout channel, tumbling at one side and the special ‘resonance’ phenomenon. The ‘resonance’ induced by the wall is shown to have a close association with the harmonious change of drag and lift on particle surface, and be sensitive to the oscillation in the wake and the periodic discharge of vorticity from behind the body.

  12. Heavy quark diffusion in strong magnetic fields at weak coupling and implications for elliptic flow

    DOE PAGESBeta

    Fukushima, Kenji; Hattori, Koichi; Yee, Ho -Ung; Yin, Yi

    2016-04-20

    In this paper, we compute the momentum diffusion coefficients of heavy quarks, κ∥ and κ⊥, in a strong magnetic field B along the directions parallel and perpendicular to B, respectively, at the leading order in QCD coupling constant αs. We consider a regime relevant for the relativistic heavy ion collisions, αseB << T2 << eB, so that thermal excitations of light quarks are restricted to the lowest Landau level (LLL) states. In the vanishing light-quark mass limit, we find κLO⊥ ∝ α2sTeB in the leading order that arises from screened Coulomb scatterings with (1+1)-dimensional LLL quarks, while κ∥ gets nomore » contribution from the scatterings with LLL quarks due to kinematic restrictions. We show that the first nonzero leading order contributions to κLO∥ come from the two separate effects: 1) the screened Coulomb scatterings with thermal gluons, and 2) a finite light-quark mass mq. The former leads to κLO,gluon∥ ∝ α2sT3 and the latter to κLO,massive∥ ∝ αs(αseB)1/2m2q. Based on our results, we propose a new scenario for the large value of heavy-quark elliptic flow observed in RHIC and LHC. Namely, when κ⊥ >> κ∥, an anisotropy in drag forces gives rise to a sizable amount of the heavy-quark elliptic flow even if heavy quarks do not fully belong to an ellipsoidally expanding background fluid.« less

  13. Heavy quark diffusion in strong magnetic fields at weak coupling and implications for elliptic flow

    NASA Astrophysics Data System (ADS)

    Fukushima, Kenji; Hattori, Koichi; Yee, Ho-Ung; Yin, Yi

    2016-04-01

    We compute the momentum diffusion coefficients of heavy quarks, κ∥ and κ⊥ , in a strong magnetic field B along the directions parallel and perpendicular to B , respectively, at the leading order in QCD coupling constant αs . We consider a regime relevant for the relativistic heavy ion collisions, αse B ≪T2≪e B , so that thermal excitations of light quarks are restricted to the lowest Landau level (LLL) states. In the vanishing light-quark mass limit, we find κ⊥LO∝αs2T e B in the leading order that arises from screened Coulomb scatterings with (1 +1 )-dimensional LLL quarks, while κ∥ gets no contribution from the scatterings with LLL quarks due to kinematic restrictions. We show that the first nonzero leading order contributions to κ∥LO come from the two separate effects: (1) the screened Coulomb scatterings with thermal gluons, and (2) a finite light-quark mass mq . The former leads to κ∥LO ,gluon∝αs2T3 and the latter to κ∥LO ,massive∝αs(αse B )1 /2mq2 . Based on our results, we propose a new scenario for the large value of heavy-quark elliptic flow observed in RHIC and LHC. Namely, when κ⊥≫κ∥, an anisotropy in drag forces gives rise to a sizable amount of the heavy-quark elliptic flow even if heavy quarks do not fully belong to an ellipsoidally expanding background fluid.

  14. The motion of a neutrally buoyant particle of an elliptic shape in two dimensional shear flow: A numerical study

    NASA Astrophysics Data System (ADS)

    Huang, Shih-Lin; Chen, Shih-Di; Pan, Tsorng-Whay; Chang, Chien-Cheng; Chu, Chin-Chou

    2015-08-01

    In this article, we investigate the motion of a neutrally buoyant particle of an elliptic shape freely moving in two dimensional shear flow by direct numerical simulation. An elliptic shape particle in shear flow, when initially being placed at the middle between two walls, either keeps rotating or has a stationary inclination angle depending on the particle Reynolds number R e = G r ra 2 / ν , where Gr is the shear rate, ra is the semi-long axis of the elliptic particle, and ν is the kinetic viscosity of the fluid. The critical particle Reynolds number Recr for the transition from a rotating motion to a stationary orientation depends on the aspect ratio AR = rb/ra and the confined ratio K = 2ra/H, where rb is the semi-short axis of the elliptic particle and H is the distance between two walls. Although the increasing of either parameters makes an increase in Recr, the dynamic mechanism is distinct. The AR variation causes the change of geometry shape; however, the K variation influences the wall effect. The stationary inclination angle of non-rotating slender elliptic particle with smaller confined ratio seems to depend only on the value of Re - Recr. An expected equilibrium position of the particle mass center in shear flow is the centerline between two walls. When placing the particle away from the centerline initially, it migrates either toward an equilibrium height away from the middle between two walls or back to the middle depending on the confined ratio and particle Reynolds number; but for higher particle Reynolds numbers, besides the previous two positions, the elliptic particle placed close to the middle just moves parallel to the wall with a stationary orientation.

  15. Spontaneous angular momentum generation of two-dimensional fluid flow in an elliptic geometry.

    PubMed

    Keetels, G H; Clercx, H J H; van Heijst, G J F

    2008-09-01

    Spontaneous spin-up, i.e., the significant increase of the total angular momentum of a flow that initially has no net angular momentum, is very characteristic for decaying two-dimensional turbulence in square domains bounded by rigid no-slip walls. In contrast, spontaneous spin-up is virtually absent for such flows in a circular domain with a no-slip boundary. In order to acquire an understanding of this strikingly different behavior observed on the square and the circle, we consider a set of elliptic geometries with a gradual increase of the eccentricity. It is shown that a variation of the eccentricity can be used as a control parameter to tune the relative contribution of the pressure and viscous stresses in the angular momentum balance. Direct numerical simulations demonstrate that the magnitude of the torque can be related to the relative contribution of the pressure. As a consequence, the number of spin-up events in an ensemble of slightly different initial conditions depends strongly on the eccentricity. For small eccentricities, strong and rapid spin-up events are observed occasionally, whereas the majority of the runs do not show significant spin-up. Small differences in the initial condition can result in a completely different evolution of the flow and an appearance of the end state of the decay process. For sufficiently large eccentricities, all the runs in the ensemble demonstrate strong and rapid spin-up, which is consistent with the flow development on the square. It is verified that the number of spin-up events for a given eccentricity does not depend on the Reynolds number of the flow. This observation is consistent with the conjecture that it is the pressure on the domain boundaries that drives the spin-up processes. PMID:18851137

  16. Elliptic flow for phi mesons and (anti)deuterons in Au+Au collisions at square root of sNN=200 GeV.

    PubMed

    Afanasiev, S; Aidala, C; Ajitanand, N N; Akiba, Y; Alexander, J; Al-Jamel, A; Aoki, K; Aphecetche, L; Armendariz, R; Aronson, S H; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Baldisseri, A; Barish, K N; Barnes, P D; Bassalleck, B; Bathe, S; Batsouli, S; Baublis, V; Bauer, F; Bazilevsky, A; Belikov, S; Bennett, R; Berdnikov, Y; Bjorndal, M T; Boissevain, J G; Borel, H; Boyle, K; Brooks, M L; Brown, D S; Bucher, D; Buesching, H; Bumazhnov, V; Bunce, G; Burward-Hoy, J M; Butsyk, S; Campbell, S; Chai, J-S; Chernichenko, S; Chiba, J; Chi, C Y; Chiu, M; Choi, I J; Chujo, T; Cianciolo, V; Cleven, C R; Cobigo, Y; Cole, B A; Comets, M P; Constantin, P; Csanád, M; Csörgo, T; Dahms, T; Das, K; David, G; Delagrange, H; Denisov, A; d'Enterria, D; Deshpande, A; Desmond, E J; Dietzsch, O; Dion, A; Drachenberg, J L; Drapier, O; Drees, A; Dubey, A K; Durum, A; Dzhordzhadze, V; Efremenko, Y V; Egdemir, J; Enokizono, A; En'yo, H; Espagnon, B; Esumi, S; Fields, D E; Fleuret, F; Fokin, S L; Forestier, B; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fukao, Y; Fung, S-Y; Gadrat, S; Gastineau, F; Germain, M; Glenn, A; Gonin, M; Gosset, J; Goto, Y; Granier de Cassagnac, R; Grau, N; Greene, S V; Grosse Perdekamp, M; Gunji, T; Gustafsson, H-A; Hachiya, T; Hadj Henni, A; Haggerty, J S; Hagiwara, M N; Hamagaki, H; Harada, H; Hartouni, E P; Haruna, K; Harvey, M; Haslum, E; Hasuko, K; Hayano, R; Heffner, M; Hemmick, T K; Heuser, J M; He, X; Hiejima, H; Hill, J C; Hobbs, R; Holmes, M; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hur, M G; Ichihara, T; Imai, K; Inaba, M; Isenhower, D; Isenhower, L; Ishihara, M; Isobe, T; Issah, M; Isupov, A; Jacak, B V; Jia, J; Jin, J; Jinnouchi, O; Johnson, B M; Joo, K S; Jouan, D; Kajihara, F; Kametani, S; Kamihara, N; Kaneta, M; Kang, J H; Kawagishi, T; Kazantsev, A V; Kelly, S; Khanzadeev, A; Kim, D J; Kim, E; Kim, Y-S; Kinney, E; Kiss, A; Kistenev, E; Kiyomichi, A; Klein-Boesing, C; Kochenda, L; Kochetkov, V; Komkov, B; Konno, M; Kotchetkov, D; Kozlov, A; Kroon, P J; Kunde, G J; Kurihara, N; Kurita, K; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Lajoie, J G; Lebedev, A; Le Bornec, Y; Leckey, S; Lee, D M; Lee, M K; Leitch, M J; Leite, M A L; Lim, H; Litvinenko, A; Liu, M X; Li, X H; Maguire, C F; Makdisi, Y I; Malakhov, A; Malik, M D; Manko, V I; Masui, H; Matathias, F; McCain, M C; McGaughey, P L; Miake, Y; Miller, T E; Milov, A; Mioduszewski, S; Mishra, G C; Mitchell, J T; Morrison, D P; Moss, J M; Moukhanova, T V; Mukhopadhyay, D; Murata, J; Nagamiya, S; Nagata, Y; Nagle, J L; Naglis, M; Nakamura, T; Newby, J; Nguyen, M; Norman, B E; Nyanin, A S; Nystrand, J; O'Brien, E; Ogilvie, C A; Ohnishi, H; Ojha, I D; Okada, H; Okada, K; Omiwade, O O; Oskarsson, A; Otterlund, I; Ozawa, K; Pal, D; Palounek, A P T; Pantuev, V; Papavassiliou, V; Park, J; Park, W J; Pate, S F; Pei, H; Peng, J-C; Pereira, H; Peresedov, V; Peressounko, D Yu; Pinkenburg, C; Pisani, R P; Purschke, M L; Purwar, A K; Qu, H; Rak, J; Ravinovich, I; Read, K F; Reuter, M; Reygers, K; Riabov, V; Riabov, Y; Roche, G; Romana, A; Rosati, M; Rosendahl, S S E; Rosnet, P; Rukoyatkin, P; Rykov, V L; Ryu, S S; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakai, S; Samsonov, V; Sato, H D; Sato, S; Sawada, S; Semenov, V; Seto, R; Sharma, D; Shea, T K; Shein, I; Shibata, T-A; Shigaki, K; Shimomura, M; Shohjoh, T; Shoji, K; Sickles, A; Silva, C L; Silvermyr, D; Sim, K S; Singh, C P; Singh, V; Skutnik, S; Smith, W C; Soldatov, A; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Staley, F; Stankus, P W; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Sugitate, T; Suire, C; Sullivan, J P; Sziklai, J; Tabaru, T; Takagi, S; Takagui, E M; Taketani, A; Tanaka, K H; Tanaka, Y; Tanida, K; Tannenbaum, M J; Taranenko, A; Tarján, P; Thomas, T L; Togawa, M; Tojo, J; Torii, H; Towell, R S; Tram, V-N; Tserruya, I; Tsuchimoto, Y; Tuli, S K; Tydesjö, H; Tyurin, N; Vale, C; Valle, H; vanHecke, H W; Velkovska, J; Vertesi, R; Vinogradov, A A; Vznuzdaev, E; Wagner, M; Wang, X R; Watanabe, Y; Wessels, J; White, S N; Willis, N; Winter, D; Woody, C L; Wysocki, M; Xie, W; Yanovich, A; Yokkaichi, S; Young, G R; Younus, I; Yushmanov, I E; Zajc, W A; Zaudtke, O; Zhang, C; Zimányi, J; Zolin, L

    2007-08-01

    Differential elliptic flow (v(2)) for phi mesons and (anti)deuterons (d)d is measured for Au+Au collisions at square root of sNN=200 GeV. The v(2) for phi mesons follows the trend of lighter pi+/- and K+/- mesons, suggesting that ordinary hadrons interacting with standard hadronic cross sections are not the primary driver for elliptic flow development. The v(2) values for (d)d suggest that elliptic flow is additive for composite particles. This further validation of the universal scaling of v(2) per constituent quark for baryons and mesons suggests that partonic collectivity dominates the transverse expansion dynamics. PMID:17930746

  17. Non-flow correlations and elliptic flow fluctuations in Au+Au collisions at sNN=200 GeV

    NASA Astrophysics Data System (ADS)

    Alver, B.; Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Busza, W.; Carroll, A.; Chai, Z.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Halliwell, C.; Hamblen, J.; Hauer, M.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Khan, N.; Kulinich, P.; Kuo, C. M.; Li, W.; Lin, W. T.; Loizides, C.; Manly, S.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Reed, C.; Roland, C.; Roland, G.; Sagerer, J.; Seals, H.; Sedykh, I.; Smith, C. E.; Stankiewicz, M. A.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tonjes, M. B.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Vaurynovich, S. S.; Verdier, R.; Veres, G. I.; Walters, P.; Wenger, E.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wysłouch, B.

    2010-03-01

    This article presents results on event-by-event elliptic flow fluctuations in Au+Au collisions at sNN= 200 GeV, where the contribution from non-flow correlations has been subtracted. An analysis method is introduced to measure non-flow correlations, relying on the assumption that non-flow correlations are most prominent at short ranges (|Δη|<2). Assuming that non-flow correlations are of the order that is observed in p+p collisions for long-range correlations (|Δη|>2), relative elliptic flow fluctuations of approximately 30-40% are observed. These results are consistent with predictions based on spatial fluctuations of the participating nucleons in the initial nuclear overlap region. It is found that the long-range non-flow correlations in Au+Au collisions would have to be more than an order of magnitude stronger compared to the p+p data to lead to the observed azimuthal anisotropy fluctuations with no intrinsic elliptic flow fluctuations.

  18. Observation of Charge Asymmetry Dependence of Pion Elliptic Flow and the Possible Chiral Magnetic Wave in Heavy-Ion Collisions.

    PubMed

    Adamczyk, L; Adkins, J K; Agakishiev, G; Aggarwal, M M; Ahammed, Z; Alekseev, I; Alford, J; Aparin, A; Arkhipkin, D; Aschenauer, E C; Averichev, G S; Banerjee, A; Bellwied, R; Bhasin, A; Bhati, A K; Bhattarai, P; Bielcik, J; Bielcikova, J; Bland, L C; Bordyuzhin, I G; Bouchet, J; Brandin, A V; Bunzarov, I; Burton, T P; Butterworth, J; Caines, H; Calderón de la Barca Sánchez, M; Campbell, J M; Cebra, D; Cervantes, M C; Chakaberia, I; Chaloupka, P; Chang, Z; Chattopadhyay, S; Chen, J H; Chen, X; Cheng, J; Cherney, M; Christie, W; Contin, G; Crawford, H J; Das, S; De Silva, L C; Debbe, R R; Dedovich, T G; Deng, J; Derevschikov, A A; di Ruzza, B; Didenko, L; Dilks, C; Dong, X; Drachenberg, J L; Draper, J E; Du, C M; Dunkelberger, L E; Dunlop, J C; Efimov, L G; Engelage, J; Eppley, G; Esha, R; Evdokimov, O; Eyser, O; Fatemi, R; Fazio, S; Federic, P; Fedorisin, J; Feng, Z; Filip, P; Fisyak, Y; Flores, C E; Fulek, L; Gagliardi, C A; Garand, D; Geurts, F; Gibson, A; Girard, M; Greiner, L; Grosnick, D; Gunarathne, D S; Guo, Y; Gupta, S; Gupta, A; Guryn, W; Hamad, A; Hamed, A; Haque, R; Harris, J W; He, L; Heppelmann, S; Heppelmann, S; Hirsch, A; Hoffmann, G W; Hofman, D J; Horvat, S; Huang, H Z; Huang, B; Huang, X; Huck, P; Humanic, T J; Igo, G; Jacobs, W W; Jang, H; Jiang, K; Judd, E G; Kabana, S; Kalinkin, D; Kang, K; Kauder, K; Ke, H W; Keane, D; Kechechyan, A; Khan, Z H; Kikola, D P; Kisel, I; Kisiel, A; Koetke, D D; Kollegger, T; Kosarzewski, L K; Kotchenda, L; Kraishan, A F; Kravtsov, P; Krueger, K; Kulakov, I; Kumar, L; Kycia, R A; Lamont, M A C; Landgraf, J M; Landry, K D; Lauret, J; Lebedev, A; Lednicky, R; Lee, J H; Li, W; Li, Y; Li, C; Li, N; Li, Z M; Li, X; Li, X; Lisa, M A; Liu, F; Ljubicic, T; Llope, W J; Lomnitz, M; Longacre, R S; Luo, X; Ma, L; Ma, R; Ma, Y G; Ma, G L; Magdy, N; Majka, R; Manion, A; Margetis, S; Markert, C; Masui, H; Matis, H S; McDonald, D; Meehan, K; Minaev, N G; Mioduszewski, S; Mohanty, B; Mondal, M M; Morozov, D A; Mustafa, M K; Nandi, B K; Nasim, Md; Nayak, T K; Nigmatkulov, G; Nogach, L V; Noh, S Y; Novak, J; Nurushev, S B; Odyniec, G; Ogawa, A; Oh, K; Okorokov, V; Olvitt, D L; Page, B S; Pak, R; Pan, Y X; Pandit, Y; Panebratsev, Y; Pawlik, B; Pei, H; Perkins, C; Peterson, A; Pile, P; Planinic, M; Pluta, J; Poljak, N; Poniatowska, K; Porter, J; Posik, M; Poskanzer, A M; Pruthi, N K; Putschke, J; Qiu, H; Quintero, A; Ramachandran, S; Raniwala, S; Raniwala, R; Ray, R L; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Roy, A; Ruan, L; Rusnak, J; Rusnakova, O; Sahoo, N R; Sahu, P K; Sakrejda, I; Salur, S; Sandweiss, J; Sarkar, A; Schambach, J; Scharenberg, R P; Schmah, A M; Schmidke, W B; Schmitz, N; Seger, J; Seyboth, P; Shah, N; Shahaliev, E; Shanmuganathan, P V; Shao, M; Sharma, B; Sharma, M K; Shen, W Q; Shi, S S; Shou, Q Y; Sichtermann, E P; Sikora, R; Simko, M; Skoby, M J; Smirnov, D; Smirnov, N; Song, L; Sorensen, P; Spinka, H M; Srivastava, B; Stanislaus, T D S; Stepanov, M; Stock, R; Strikhanov, M; Stringfellow, B; Sumbera, M; Summa, B J; Sun, X; Sun, X M; Sun, Z; Sun, Y; Surrow, B; Svirida, D N; Szelezniak, M A; Tang, Z; Tang, A H; Tarnowsky, T; Tawfik, A N; Thomas, J H; Timmins, A R; Tlusty, D; Tokarev, M; Trentalange, S; Tribble, R E; Tribedy, P; Tripathy, S K; Trzeciak, B A; Tsai, O D; Ullrich, T; Underwood, D G; Upsal, I; Van Buren, G; van Nieuwenhuizen, G; Vandenbroucke, M; Varma, R; Vasiliev, A N; Vertesi, R; Videbaek, F; Viyogi, Y P; Vokal, S; Voloshin, S A; Vossen, A; Wang, F; Wang, Y; Wang, H; Wang, J S; Wang, Y; Wang, G; Webb, G; Webb, J C; Wen, L; Westfall, G D; Wieman, H; Wissink, S W; Witt, R; Wu, Y F; Xiao, Z; Xie, W; Xin, K; Xu, Y F; Xu, N; Xu, Z; Xu, Q H; Xu, H; Yang, Y; Yang, Y; Yang, C; Yang, S; Yang, Q; Ye, Z; Yepes, P; Yi, L; Yip, K; Yoo, I-K; Yu, N; Zbroszczyk, H; Zha, W; Zhang, X P; Zhang, J B; Zhang, J; Zhang, Z; Zhang, S; Zhang, Y; Zhang, J L; Zhao, F; Zhao, J; Zhong, C; Zhou, L; Zhu, X; Zoulkarneeva, Y; Zyzak, M

    2015-06-26

    We present measurements of π(-) and π(+) elliptic flow, v(2), at midrapidity in Au+Au collisions at √[s(NN)]=200, 62.4, 39, 27, 19.6, 11.5, and 7.7 GeV, as a function of event-by-event charge asymmetry, A(ch), based on data from the STAR experiment at RHIC. We find that π(-) (π(+)) elliptic flow linearly increases (decreases) with charge asymmetry for most centrality bins at √[s(NN)]=27  GeV and higher. At √[s(NN)]=200  GeV, the slope of the difference of v(2) between π(-) and π(+) as a function of A(ch) exhibits a centrality dependence, which is qualitatively similar to calculations that incorporate a chiral magnetic wave effect. Similar centrality dependence is also observed at lower energies. PMID:26197122

  19. Observation of Charge Asymmetry Dependence of Pion Elliptic Flow and the Possible Chiral Magnetic Wave in Heavy-Ion Collisions

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandin, A. V.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cervantes, M. C.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, J. H.; Chen, X.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, S.; Gupta, A.; Guryn, W.; Hamad, A.; Hamed, A.; Haque, R.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, H. Z.; Huang, B.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Jiang, K.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Kosarzewski, L. K.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, W.; Li, Y.; Li, C.; Li, N.; Li, Z. M.; Li, X.; Li, X.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, L.; Ma, R.; Ma, Y. G.; Ma, G. L.; Magdy, N.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; Meehan, K.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V.; Olvitt, D. L.; Page, B. S.; Pak, R.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Peterson, A.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, S.; Raniwala, R.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Sharma, M. K.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stepanov, M.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B. J.; Sun, X.; Sun, X. M.; Sun, Z.; Sun, Y.; Surrow, B.; Svirida, D. N.; Szelezniak, M. A.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A. N.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasiliev, A. N.; Vertesi, R.; Videbaek, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, F.; Wang, Y.; Wang, H.; Wang, J. S.; Wang, Y.; Wang, G.; Webb, G.; Webb, J. C.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, Y. F.; Xu, N.; Xu, Z.; Xu, Q. H.; Xu, H.; Yang, Y.; Yang, Y.; Yang, C.; Yang, S.; Yang, Q.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, X. P.; Zhang, J. B.; Zhang, J.; Zhang, Z.; Zhang, S.; Zhang, Y.; Zhang, J. L.; Zhao, F.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2015-06-01

    We present measurements of π- and π+ elliptic flow, v2, at midrapidity in Au +Au collisions at √{sNN }=200 , 62.4, 39, 27, 19.6, 11.5, and 7.7 GeV, as a function of event-by-event charge asymmetry, Ach, based on data from the STAR experiment at RHIC. We find that π- (π+) elliptic flow linearly increases (decreases) with charge asymmetry for most centrality bins at √{sNN }=27 GeV and higher. At √{sNN }=200 GeV , the slope of the difference of v2 between π- and π+ as a function of Ach exhibits a centrality dependence, which is qualitatively similar to calculations that incorporate a chiral magnetic wave effect. Similar centrality dependence is also observed at lower energies.

  20. The Numerical Calculation of Flow Past Conical Bodies Supporting Elliptic Conical Shock Waves at Finite Angles of Incidence

    NASA Technical Reports Server (NTRS)

    Briggs, Benjamin R.

    1960-01-01

    The inverse method, with the shock wave prescribed to be an elliptic cone at a finite angle of incidence, is applied to calculate numerically the supersonic perfect-gas flow past conical bodies not having axial symmetry. Two formulations of the problem are employed, one using a pair of stream functions and the other involving entropy and components of velocity. A number of solutions are presented, illustrating the numerical methods employed, and showing the effects of moderate variation of the initial parameters.

  1. Neutron-proton elliptic flow difference as a probe for the high density dependence of the symmetry energy

    NASA Astrophysics Data System (ADS)

    Cozma, M. D.

    2011-06-01

    We employ an isospin dependent version of the QMD transport model to study the influence of the isospin dependent part of the nuclear matter equation of state and in-medium nucleon-nucleon cross-sections on the dynamics of heavy-ion collisions at intermediate energies. We find that the extraction of useful information on the isospin-dependent part of the equation of state of nuclear matter from proton or neutron elliptic flows is obstructed by their sensitivity to model parameters and in-medium values of nucleon-nucleon cross-sections. Opposite to that, neutron-proton elliptic flow difference shows little dependence on those variables while its dependence on the isospin asymmetric EoS is enhanced, making it more suitable for a model independent constraining of the high-density behaviour of asy-EoS. Comparison with existing experimental FOPI-LAND neutron-hydrogen data can be used to set an upper limit to the softness of asy-EoS. Successful constraining of the asy-EoS via neutron-proton elliptic flow difference will require experimental data of higher accuracy than presently available.

  2. Deconvolved spectra of Two Component Advective Flow including jet

    NASA Astrophysics Data System (ADS)

    Mondal, Santanu; Debnath, Dipak; Chakrabarti, Sandip Kumar

    2016-07-01

    Outflows and winds are produced when the accretion flows have positive specific energy. Two Component Advective Flow (TCAF) model suggests that the centrifugal pressure supported region of the flow outside the black hole horizon, acts as the base of this outflow. We study the spectral properties of the TCAF which includes a jet component. We consider the jet as a conical in shape which also up-scatters the soft photons from the Keplerian disc. We see that due to the presence of jet component, spectrum become harder as the jet itself behaves like an another Compton cloud above the inner hot corona. We also see how the jet spectra depends on the flow rates. This gives the direct link in timing properties of the X-rays in CENBOL component and the radiation emitted in the jet component.

  3. Behaviour of a rimmed elliptical inclusion in 2D slow incompressible viscous flow

    NASA Astrophysics Data System (ADS)

    Mancktelow, N. S.

    2012-04-01

    The shape preferred orientation of natural populations of inclusions (or "porphyroclasts") is often inconsistent with predictions from established analytical theory for inclusions with coherent boundaries (e.g., Pennacchioni et al. 2001). A totally incoherent or slipping interface can explain observed stable back-rotated (or antithetic) orientations but not the observed cut-off axial ratio, below which inclusions still rotate. However, this behaviour is reproduced by a rimmed inclusion with a rim viscosity that is not infinitely weak but still weaker than the matrix (e.g., Schmid and Podladchikov 2005; Johnson et al. 2009). In this study, finite-element numerical modelling (FEM) is employed to investigate this system in 2D over a very wide parameter space, from a viscosity ratio (relative to the matrix) of the inclusion from 106 to 1, the rim from 10-6 to 1, the axial ratio from 1.00025 to 20, and the rim thickness from 5% to 20%. Theoretical consideration of a concentric elliptical inclusion and ellipse reduces the number of scalar values to be determined to fully characterize the system to two: one for the rate of stretch of the inclusion and one for the rate of rotation. From these two values, the rotation and stretching rate can be calculated for any orientation and 2D background flow field. For effectively rigid particles, the cut-off axial ratio between rotation and stabilization is determined by the remaining two parameters, namely the rim viscosity and the thickness, with low rim viscosity or thick rims promoting stabilization. The shape fabric of a population of particles in a high strain shear zone, presented as a typical Rf/φ plot, can be forward modelled using an initial value Ordinary Differential Equation (ODE) approach. Because the rim does not remain elliptical to high strain, this method cannot accurately model the behaviour of individual inclusions. However, a statistical approach, allowing variation in rim viscosity, which is also a proxy for

  4. The Compressible Potential Flow Past Elliptic Symmetrical Cylinders at Zero Angle of Attack and with No Circulation

    NASA Technical Reports Server (NTRS)

    Hantzsche, W.; Wendt, H.

    1942-01-01

    For the tunnel corrections of compressible flows those profiles are of interest for which at least the second approximation of the Janzen-Rayleigh method can be applied in closed form. One such case is presented by certain elliptical symmetrical cylinders located in the center of a tunnel with fixed walls and whose maximum velocity, incompressible, is twice the velocity of flow. In the numerical solution the maximum velocity at the profile and the tunnel wall as well as the entry of sonic velocity is computed. The velocity distribution past the contour and in the minimum cross section at various Mach numbers is illustrated on a worked out-example.

  5. Eigenfrequencies of vortex-pair equilibria near an elliptic cylinder or a flat plate in uniform flow.

    PubMed

    de Laat, T W G

    2007-03-01

    The eigenfrequencies of the potential-flow equilibria of a symmetric vortex pair behind an elliptic cylinder in uniform flow are calculated through the use of conformal mapping. These frequencies are shown to have values in agreement with measured Strouhal numbers reported in various papers. The special cases of the potential-flow equilibrium of a symmetric vortex pair behind a circular cylinder and the equilibrium behind a flat plate perpendicular to the uniform flow, are related to the measured Strouhal numbers of about 0.21 and 0.15, respectively. It is suggested that in the range of subcritical Reynolds numbers, 3x10(2) to 5x10(5) for the circular cylinder, a part of the drag is the result of the presence of a mean recirculation region in the near wake, which sheds vortices in the far wake and which is fed by vorticity from the cylinder wall. PMID:17500786

  6. Ideal hydrodynamics and elliptic flow at CERN Super Proton Synchrotron (SPS) energies: Importance of the initial conditions

    SciTech Connect

    Petersen, Hannah; Bleicher, Marcus

    2009-05-15

    The elliptic flow excitation function calculated in a full (3+1) dimensional hybrid Boltzmann approach with an intermediate hydrodynamic stage for heavy ion reactions from GSI Schwerionen Synchrotron to the highest CERN Super Proton Synchrotron (SPS) energies is discussed in the context of the experimental data. In this study, we employ a hadron gas equation of state to investigate the differences in the dynamics and viscosity effects. The specific event-by-event setup with initial conditions and freeze-out from a nonequilibrium transport model allows for a direct comparison between ideal fluid dynamics and transport simulations. At higher SPS energies, where the pure transport calculation cannot account for the high elliptic flow values, the smaller mean free path in the hydrodynamic evolution leads to higher elliptic flow values. In contrast to previous studies within pure hydrodynamics, the more realistic initial conditions employed here and the inclusion of a sequential final state hadronic decoupling provides results that are in line with the experimental data almost over the whole energy range from E{sub lab}=2-160A GeV. Thus, this new approach leads to a substantially different shape of the v{sub 2}/{epsilon} scaling curve as a function of (1/SdN{sub ch}/dy) in line with the experimental data compared to previous ideal hydrodynamic calculations. This hints at a strong influence of the initial conditions for the hydrodynamic evolution on the finally observed v{sub 2} values, thus questioning the standard interpretation that the hydrodynamic limit is only reached at BNL Relativistic Heavy Ion Collider energies.

  7. Blast wave fits to elliptic flow data at √{sNN}=7.7 - 2760 GeV

    NASA Astrophysics Data System (ADS)

    Sun, X.; Masui, H.; Poskanzer, A. M.; Schmah, A.

    2015-02-01

    We present blast wave fits to elliptic flow [v2(pT) ] data in minimum bias collisions from √{sNN}=7.7 - 200 GeV at the BNL Relativistic Heavy Ion Collider, and also at the CERN Large Hadron Collider energy of 2.76 TeV. The fits are performed separately for particles and corresponding antiparticles. The mean transverse velocity parameter β shows an energy-dependent difference between particles and corresponding antiparticles, which increases as the beam energy decreases. Possible effects of feed down, baryon stopping, antiparticle absorption, and early production times for antiparticles are discussed.

  8. Centrality and pseudorapidity dependence of elliptic flow for charged hadrons in Au+Au collisions at √(sNN)=200 GeV

    NASA Astrophysics Data System (ADS)

    Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Decowski, M. P.; García, E.; George, N. K.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Mignerey, A. C.; Nguyen, M.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steinberg, P.; Stephans, G. S.; Sukhanov, A.; Tang, J.-L.; Tonjes, M. B.; Trzupek, A.; Vale, C. M.; Nieuwenhuizen, G. J.; Verdier, R.; Veres, G. I.; Wolfs, F. L.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

    2005-11-01

    This Rapid Communication describes the measurement of elliptic flow for charged particles in Au+Au collisions at √(sNN)=200 GeV using the PHOBOS detector at the Relativistic Heavy Ion Collider. The measured azimuthal anisotropy is presented over a wide range of pseudorapidity for three broad collision centrality classes for the first time at this energy. Two distinct methods of extracting the flow signal were used to reduce systematic uncertainties. The elliptic flow falls sharply with increasing |η| at 200 GeV for all the centralities studied, as observed for minimum-bias collisions at √(sNN)=130 GeV.

  9. Observation of charge asymmetry dependence of pion elliptic flow and the possible chiral magnetic wave in heavy-ion collisions

    SciTech Connect

    Adamczyk, L.

    2015-06-26

    We present measurements of π⁻ and π⁺ elliptic flow, v₂, at midrapidity in Au+Au collisions at √sNN = 200, 62.4, 39, 27, 19.6, 11.5, and 7.7 GeV, as a function of event-by-event charge asymmetry, Ach, based on data from the STAR experiment at RHIC. We find that π⁻ (π⁺) elliptic flow linearly increases (decreases) with charge asymmetry for most centrality bins at √sNN = 27 GeV and higher. At √sNN = 200 GeV, the slope of the difference of v₂ between π⁻ and π⁺ as a function of Ach exhibits a centrality dependence, which is qualitatively similar to calculations that incorporate a chiral magnetic wave effect. In addition, similar centrality dependence is also observed at lower energies.

  10. Observation of charge asymmetry dependence of pion elliptic flow and the possible chiral magnetic wave in heavy-ion collisions

    DOE PAGESBeta

    Adamczyk, L.

    2015-06-26

    We present measurements of π⁻ and π⁺ elliptic flow, v₂, at midrapidity in Au+Au collisions at √sNN = 200, 62.4, 39, 27, 19.6, 11.5, and 7.7 GeV, as a function of event-by-event charge asymmetry, Ach, based on data from the STAR experiment at RHIC. We find that π⁻ (π⁺) elliptic flow linearly increases (decreases) with charge asymmetry for most centrality bins at √sNN = 27 GeV and higher. At √sNN = 200 GeV, the slope of the difference of v₂ between π⁻ and π⁺ as a function of Ach exhibits a centrality dependence, which is qualitatively similar to calculations thatmore » incorporate a chiral magnetic wave effect. In addition, similar centrality dependence is also observed at lower energies.« less

  11. J/ψ Elliptic Flow in Pb-Pb Collisions at sNN=2.76TeV

    NASA Astrophysics Data System (ADS)

    Abbas, E.; Abelev, B.; Adam, J.; Adamová, D.; Adare, A. M.; Aggarwal, M. M.; Aglieri Rinella, G.; Agnello, M.; Agocs, A. G.; Agostinelli, A.; Ahammed, Z.; Ahmad, N.; Ahmad Masoodi, A.; Ahn, S. A.; Ahn, S. U.; Aimo, I.; Ajaz, M.; Akindinov, A.; Aleksandrov, D.; Alessandro, B.; Alici, A.; Alkin, A.; Almaráz Aviña, E.; Alme, J.; Alt, T.; Altini, V.; Altinpinar, S.; Altsybeev, I.; Andrei, C.; Andronic, A.; Anguelov, V.; Anielski, J.; Anson, C.; Antičić, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Arbor, N.; Arcelli, S.; Arend, A.; Armesto, N.; Arnaldi, R.; Aronsson, T.; Arsene, I. C.; Arslandok, M.; Asryan, A.; Augustinus, A.; Averbeck, R.; Awes, T. C.; Äystö, J.; Azmi, M. D.; Bach, M.; Badalà, A.; Baek, Y. W.; Bailhache, R.; Bala, R.; Baldisseri, A.; Baltasar Dos Santos Pedrosa, F.; Bán, J.; Baral, R. C.; Barbera, R.; Barile, F.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartke, J.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Batyunya, B.; Batzing, P. C.; Baumann, C.; Bearden, I. G.; Beck, H.; Behera, N. K.; Belikov, I.; Bellini, F.; Bellwied, R.; Belmont-Moreno, E.; Bencedi, G.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Bergognon, A. A. E.; Bertens, R. A.; Berzano, D.; Betev, L.; Bhasin, A.; Bhati, A. K.; Bhom, J.; Bianchi, N.; Bianchi, L.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Bjelogrlic, S.; Blanco, F.; Blanco, F.; Blau, D.; Blume, C.; Boccioli, M.; Böttger, S.; Bogdanov, A.; Bøggild, H.; Bogolyubsky, M.; Boldizsár, L.; Bombara, M.; Book, J.; Borel, H.; Borissov, A.; Bossú, F.; Botje, M.; Botta, E.; Braidot, E.; Braun-Munzinger, P.; Bregant, M.; Breitner, T.; Broker, T. A.; Browning, T. A.; Broz, M.; Brun, R.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buncic, P.; Busch, O.; Buthelezi, Z.; Caffarri, D.; Cai, X.; Caines, H.; Calvo Villar, E.; Camerini, P.; Canoa Roman, V.; Cara Romeo, G.; Carena, W.; Carena, F.; Carlin Filho, N.; Carminati, F.; Casanova Díaz, A.; Castillo Castellanos, J.; Castillo Hernandez, J. F.; Casula, E. A. R.; Catanescu, V.; Cavicchioli, C.; Ceballos Sanchez, C.; Cepila, J.; Cerello, P.; Chang, B.; Chapeland, S.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chibante Barroso, V.; Chinellato, D. D.; Chochula, P.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Conesa Balbastre, G.; Conesa del Valle, Z.; Connors, M. E.; Contin, G.; Contreras, J. G.; Cormier, T. M.; Corrales Morales, Y.; Cortese, P.; Cortés Maldonado, I.; Cosentino, M. R.; Costa, F.; Cotallo, M. E.; Crescio, E.; Crochet, P.; Cruz Alaniz, E.; Cruz Albino, R.; Cuautle, E.; Cunqueiro, L.; Dainese, A.; Dang, R.; Danu, A.; Das, D.; Das, K.; Das, S.; Das, I.; Dash, A.; Dash, S.; De, S.; de Barros, G. O. V.; De Caro, A.; de Cataldo, G.; de Cuveland, J.; De Falco, A.; De Gruttola, D.; Delagrange, H.; Deloff, A.; De Marco, N.; Dénes, E.; De Pasquale, S.; Deppman, A.; D'Erasmo, G.; de Rooij, R.; Diaz Corchero, M. A.; Di Bari, D.; Dietel, T.; Di Giglio, C.; Di Liberto, S.; Di Mauro, A.; Di Nezza, P.; Divià, R.; Djuvsland, Ø.; Dobrin, A.; Dobrowolski, T.; Dönigus, B.; Dordic, O.; Driga, O.; Dubey, A. K.; Dubla, A.; Ducroux, L.; Dupieux, P.; Dutta Majumdar, A. K.; Elia, D.; Emschermann, D.; Engel, H.; Erazmus, B.; Erdal, H. A.; Eschweiler, D.; Espagnon, B.; Estienne, M.; Esumi, S.; Evans, D.; Evdokimov, S.; Eyyubova, G.; Fabris, D.; Faivre, J.; Falchieri, D.; Fantoni, A.; Fasel, M.; Fehlker, D.; Feldkamp, L.; Felea, D.; Feliciello, A.; Fenton-Olsen, B.; Feofilov, G.; Fernández Téllez, A.; Ferretti, A.; Festanti, A.; Figiel, J.; Figueredo, M. A. S.; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Floratos, E.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; Frankenfeld, U.; Fuchs, U.; Furget, C.; Fusco Girard, M.; Gaardhøje, J. J.; Gagliardi, M.; Gago, A.; Gallio, M.; Gangadharan, D. R.; Ganoti, P.; Garabatos, C.; Garcia-Solis, E.; Gargiulo, C.; Garishvili, I.; Gerhard, J.; Germain, M.; Geuna, C.; Gheata, A.; Gheata, M.; Ghidini, B.; Ghosh, P.; Gianotti, P.; Girard, M. R.; Giubellino, P.; Gladysz-Dziadus, E.; Glässel, P.; Gomez, R.; Ferreiro, E. G.; González-Trueba, L. H.; González-Zamora, P.; Gorbunov, S.; Goswami, A.; Gotovac, S.; Graczykowski, L. K.; Grajcarek, R.; Grelli, A.; Grigoras, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Gros, P.; Grosse-Oetringhaus, J. F.; Grossiord, J.-Y.; Grosso, R.; Guber, F.; Guernane, R.; Guerzoni, B.; Guilbaud, M.; Gulbrandsen, K.

    2013-10-01

    We report on the first measurement of inclusive J/ψ elliptic flow v2 in heavy-ion collisions at the LHC. The measurement is performed with the ALICE detector in Pb-Pb collisions at sNN=2.76TeV in the rapidity range 2.5elliptic flow measurement complements the previously reported ALICE results on the inclusive J/ψ nuclear modification factor and favors the scenario of a significant fraction of J/ψ production from charm quarks in a deconfined partonic phase.

  12. Surface Waves and Flow-Induced Oscillations along an Underground Elliptic Cylinder Filled with a Viscous Fluid

    NASA Astrophysics Data System (ADS)

    Sakuraba, A.

    2015-12-01

    I made a linear analysis of flow-induced oscillations along an underground cylindrical conduit with an elliptical cross section on the basis of the hypothesis that volcanic tremor is a result of magma movement through a conduit. As a first step to understand how the self oscillation occurs because of magma flow, I investigated surface wave propagation and attenuation along an infinitely long fluid-filled elliptic cylinder in an elastic medium. The boundary element method is used to obtain the two-dimensional wave field around the ellipse in the frequency-wavenumber domain. When the major axis is much greater than the minor axis of the ellipse, we obtain the analytic form of the dispersion relation of both the crack-wave mode (Korneev 2008, Lipovsky & Dunham 2015) and the Rayleigh-wave mode with flexural deformation. The crack-wave mode generally has a slower phase speed and a higher attenuation than the Rayleigh-wave mode. In the long-wavelength limit, the crack-wave mode disappears because of fluid viscosity, but the Rayleigh-wave mode exists with a constant Q-value that depends on viscosity. When the aspect ratio of the ellipse is finite, the surface waves can basically be understood as those propagating along a fluid pipe. The flexural mode does exist even when the wavelength is much longer than the major axis, but its phase speed coincides with that of the surrounding S-wave (Randall 1991). As its attenuation is zero in the long-wavelength limit, the flexural mode differs in nature from surface wave. I also obtain a result on linear stability of viscous flow through an elliptic cylinder. In this analysis, I made an assumption that the fluid inertia is so small that the Stokes equation can be used. As suggested by the author's previous study (Sakuraba & Yamauchi 2014), the flexural (Rayleigh-wave) mode is destabilized at a critical flow speed that decreases with the wavelength. However, when the wavelength is much greater than the major axis of the ellipse, the

  13. Calculation of supersonic three-dimensional free-mixing flows using the parabolic-elliptic Navier-Stokes equations

    NASA Technical Reports Server (NTRS)

    Hirsh, R. S.

    1975-01-01

    A numerical method is presented which is valid for integration of the parabolic-elliptic Navier-Stokes equations. The solution procedure is applied to the three-dimensional supersonic flow of a jet issuing into a supersonic free stream. Difficulties associated with the imposition of free-stream boundary conditions are noted, and a coordinate transformation, which maps the point at infinity onto a finite value, is introduced to alleviate these difficulties. Results are presented for calculations of a square jet and varying-aspect-ratio rectangular jets. The solution behavior varies from axisymmetry for the square jet to nearly two-dimensional for the high-aspect-ratio rectangle, although the computation always calculates the flow as though it were truly three-dimensional.

  14. Production and elliptic flow of dileptons and photons in a matrix model of the quark-gluon plasma.

    PubMed

    Gale, Charles; Hidaka, Yoshimasa; Jeon, Sangyong; Lin, Shu; Paquet, Jean-François; Pisarski, Robert D; Satow, Daisuke; Skokov, Vladimir V; Vujanovic, Gojko

    2015-02-20

    We consider a nonperturbative approach to the thermal production of dileptons and photons at temperatures near the critical temperature in QCD. The suppression of colored excitations at low temperature is modeled by including a small value of the Polyakov loop, in a "semi"-quark-gluon plasma (QGP). Comparing the semi-QGP to the perturbative QGP, we find a mild enhancement of thermal dileptons. In contrast, to leading logarithmic order in weak coupling there are far fewer hard photons from the semi-QGP than the usual QGP. To illustrate the possible effects on photon and dilepton production in heavy-ion collisions, we integrate the rate with a simulation using ideal hydrodynamics. Dileptons uniformly exhibit a small flow, but the strong suppression of photons in the semi-QGP tends to weight the elliptical flow of photons to that generated in the hadronic phase. PMID:25763954

  15. D meson elliptic flow in noncentral Pb-Pb collisions at sqrt[sNN]=2.76 Tev.

    PubMed

    Abelev, B; Adam, J; Adamová, D; Adare, A M; Aggarwal, M M; Aglieri Rinella, G; Agnello, M; Agocs, A G; Agostinelli, A; Ahammed, Z; Ahmad, N; Ahmad Masoodi, A; Ahmed, I; Ahn, S U; Ahn, S A; Aimo, I; Ajaz, M; Akindinov, A; Aleksandrov, D; Alessandro, B; Alexandre, D; Alici, A; Alkin, A; Alme, J; Alt, T; Altini, V; Altinpinar, S; Altsybeev, I; Andrei, C; Andronic, A; Anguelov, V; Anielski, J; Anson, C; Antičić, T; Antinori, F; Antonioli, P; Aphecetche, L; Appelshäuser, H; Arbor, N; Arcelli, S; Arend, A; Armesto, N; Arnaldi, R; Aronsson, T; Arsene, I C; Arslandok, M; Asryan, A; Augustinus, A; Averbeck, R; Awes, T C; Äystö, J; Azmi, M D; Bach, M; Badalà, A; Baek, Y W; Bailhache, R; Bala, R; Baldisseri, A; Baltasar Dos Santos Pedrosa, F; Bán, J; Baral, R C; Barbera, R; Barile, F; Barnaföldi, G G; Barnby, L S; Barret, V; Bartke, J; Basile, M; Bastid, N; Basu, S; Bathen, B; Batigne, G; Batyunya, B; Batzing, P C; Baumann, C; Bearden, I G; Beck, H; Behera, N K; Belikov, I; Bellini, F; Bellwied, R; Belmont-Moreno, E; Bencedi, G; Beole, S; Berceanu, I; Bercuci, A; Berdnikov, Y; Berenyi, D; Bergognon, A A E; Bertens, R A; Berzano, D; Betev, L; Bhasin, A; Bhati, A K; Bhom, J; Bianchi, N; Bianchi, L; Bianchin, C; Bielčík, J; Bielčíková, J; Bilandzic, A; Bjelogrlic, S; Blanco, F; Blanco, F; Blau, D; Blume, C; Boccioli, M; Böttger, S; Bogdanov, A; Bøggild, H; Bogolyubsky, M; Boldizsár, L; Bombara, M; Book, J; Borel, H; Borissov, A; Bossú, F; Botje, M; Botta, E; Braidot, E; Braun-Munzinger, P; Bregant, M; Breitner, T; Broker, T A; Browning, T A; Broz, M; Brun, R; Bruna, E; Bruno, G E; Budnikov, D; Buesching, H; Bufalino, S; Buncic, P; Busch, O; Buthelezi, Z; Caffarri, D; Cai, X; Caines, H; Caliva, A; Calvo Villar, E; Camerini, P; Canoa Roman, V; Cara Romeo, G; Carena, F; Carena, W; Carlin Filho, N; Carminati, F; Casanova Díaz, A; Castillo Castellanos, J; Castillo Hernandez, J F; Casula, E A R; Catanescu, V; Cavicchioli, C; Ceballos Sanchez, C; Cepila, J; Cerello, P; Chang, B; Chapeland, S; Charvet, J L; Chattopadhyay, S; Chattopadhyay, S; Cherney, M; Cheshkov, C; Cheynis, B; Chibante Barroso, V; Chinellato, D D; Chochula, P; Chojnacki, M; Choudhury, S; Christakoglou, P; Christensen, C H; Christiansen, P; Chujo, T; Chung, S U; Cicalo, C; Cifarelli, L; Cindolo, F; Cleymans, J; Colamaria, F; Colella, D; Collu, A; Conesa Balbastre, G; Conesa del Valle, Z; Connors, M E; Contin, G; Contreras, J G; Cormier, T M; Corrales Morales, Y; Cortese, P; Cortés Maldonado, I; Cosentino, M R; Costa, F; Cotallo, M E; Crescio, E; Crochet, P; Cruz Alaniz, E; Cruz Albino, R; Cuautle, E; Cunqueiro, L; Dainese, A; Dang, R; Danu, A; Das, S; Das, K; Das, I; Das, D; Dash, S; Dash, A; De, S; de Barros, G O V; De Caro, A; de Cataldo, G; de Cuveland, J; De Falco, A; De Gruttola, D; Delagrange, H; Deloff, A; De Marco, N; Dénes, E; De Pasquale, S; Deppman, A; D'Erasmo, G; de Rooij, R; Diaz Corchero, M A; Di Bari, D; Dietel, T; Di Giglio, C; Di Liberto, S; Di Mauro, A; Di Nezza, P; Divià, R; Djuvsland, Ø; Dobrin, A; Dobrowolski, T; Dönigus, B; Dordic, O; Dubey, A K; Dubla, A; Ducroux, L; Dupieux, P; Dutta Majumdar, A K; Elia, D; Elwood, B G; Emschermann, D; Engel, H; Erazmus, B; Erdal, H A; Eschweiler, D; Espagnon, B; Estienne, M; Esumi, S; Evans, D; Evdokimov, S; Eyyubova, G; Fabris, D; Faivre, J; Falchieri, D; Fantoni, A; Fasel, M; Fehlker, D; Feldkamp, L; Felea, D; Feliciello, A; Fenton-Olsen, B; Feofilov, G; Fernández Téllez, A; Ferretti, A; Festanti, A; Figiel, J; Figueredo, M A S; Filchagin, S; Finogeev, D; Fionda, F M; Fiore, E M; Floratos, E; Floris, M; Foertsch, S; Foka, P; Fokin, S; Fragiacomo, E; Francescon, A; Frankenfeld, U; Fuchs, U; Furget, C; Fusco Girard, M; Gaardhøje, J J; Gagliardi, M; Gago, A; Gallio, M; Gangadharan, D R; Ganoti, P; Garabatos, C; Garcia-Solis, E; Gargiulo, C; Garishvili, I; Gerhard, J; Germain, M; Geuna, C; Gheata, A; Gheata, M; Ghidini, B; Ghosh, P; Gianotti, P; Giubellino, P; Gladysz-Dziadus, E; Glässel, P; Goerlich, L; Gomez, R; Ferreiro, E G; González-Zamora, P; Gorbunov, S; Goswami, A; Gotovac, S; Graczykowski, L K; Grajcarek, R; Grelli, A; Grigoras, C; Grigoras, A; Grigoriev, V; Grigoryan, S; Grigoryan, A; Grinyov, B; Grion, N; Gros, P; Grosse-Oetringhaus, J F; Grossiord, J-Y; Grosso, R; Guber, F; Guernane, R; Guerzoni, B; Guilbaud, M; Gulbrandsen, K; Gulkanyan, H; Gunji, T; Gupta, A; Gupta, R; Haake, R; Haaland, Ø; Hadjidakis, C; Haiduc, M; Hamagaki, H; Hamar, G; Han, B H; Hanratty, L D; Hansen, A; Harris, J W; Harton, A; Hatzifotiadou, D; Hayashi, S; Hayrapetyan, A; Heckel, S T; Heide, M; Helstrup, H; Herghelegiu, A; Herrera Corral, G; Herrmann, N; Hess, B A; Hetland, K F; Hicks, B; Hippolyte, B; Hori, Y; Hristov, P; Hřivnáčová, I; Huang, M; Humanic, T J; Hwang, D S; Ichou, R; Ilkaev, R; Ilkiv, I; Inaba, M; Incani, E; Innocenti, P G; Innocenti, G M; Ionita, C; Ippolitov, M; Irfan, M; Ivan, C; Ivanov, A; Ivanov, M; Ivanov, V; Ivanytskyi, O; Jachołkowski, A; Jacobs, P M; Jahnke, C; Jang, H J; Janik, M A; Jayarathna, P H S Y; Jena, S; Jha, D M; Jimenez Bustamante, R T; Jones, P G; Jung, H; Jusko, A; Kaidalov, A B; Kalcher, S; Kaliňák, P; Kalliokoski, T; Kalweit, A; Kang, J H; Kaplin, V; Kar, S; Karasu Uysal, A; Karavichev, O; Karavicheva, T; Karpechev, E; Kazantsev, A; Kebschull, U; Keidel, R; Ketzer, B; Khan, S A; Khan, M M; Khan, K H; Khan, P; Khanzadeev, A; Kharlov, Y; Kileng, B; Kim, J H; Kim, D W; Kim, T; Kim, S; Kim, B; Kim, M; Kim, M; Kim, J S; Kim, D J; Kirsch, S; Kisel, I; Kiselev, S; Kisiel, A; Klay, J L; Klein, J; Klein-Bösing, C; Kliemant, M; Kluge, A; Knichel, M L; Knospe, A G; Köhler, M K; Kollegger, T; Kolojvari, A; Kompaniets, M; Kondratiev, V; Kondratyeva, N; Konevskikh, A; Kovalenko, V; Kowalski, M; Kox, S; Koyithatta Meethaleveedu, G; Kral, J; Králik, I; Kramer, F; Kravčáková, A; Krelina, M; Kretz, M; Krivda, M; Krizek, F; Krus, M; Kryshen, E; Krzewicki, M; Kucera, V; Kucheriaev, Y; Kugathasan, T; Kuhn, C; Kuijer, P G; Kulakov, I; Kumar, J; Kurashvili, P; Kurepin, A B; Kurepin, A; Kuryakin, A; Kushpil, S; Kushpil, V; Kvaerno, H; Kweon, M J; Kwon, Y; Ladrón de Guevara, P; Lagana Fernandes, C; Lakomov, I; Langoy, R; La Pointe, S L; Lara, C; Lardeux, A; La Rocca, P; Lea, R; Lechman, M; Lee, S C; Lee, G R; Legrand, I; Lehnert, J; Lemmon, R C; Lenhardt, M; Lenti, V; León, H; Leoncino, M; León Monzón, I; Lévai, P; Li, S; Lien, J; Lietava, R; Lindal, S; Lindenstruth, V; Lippmann, C; Lisa, M A; Ljunggren, H M; Lodato, D F; Loenne, P I; Loggins, V R; Loginov, V; Lohner, D; Loizides, C; Loo, K K; Lopez, X; López Torres, E; Løvhøiden, G; Lu, X-G; Luettig, P; Lunardon, M; Luo, J; Luparello, G; Luzzi, C; Ma, R; Ma, K; Madagodahettige-Don, D M; Maevskaya, A; Mager, M; Mahapatra, D P; Maire, A; Malaev, M; Maldonado Cervantes, I; Malinina, L; Mal'Kevich, D; Malzacher, P; Mamonov, A; Manceau, L; Mangotra, L; Manko, V; Manso, F; Manzari, V; Marchisone, M; Mareš, J; Margagliotti, G V; Margotti, A; Marín, A; Markert, C; Marquard, M; Martashvili, I; Martin, N A; Martin Blanco, J; Martinengo, P; Martínez, M I; Martínez García, G; Martynov, Y; Mas, A; Masciocchi, S; Masera, M; Masoni, A; Massacrier, L; Mastroserio, A; Matyja, A; Mayer, C; Mazer, J; Mazumder, R; Mazzoni, M A; Meddi, F; Menchaca-Rocha, A; Mercado Pérez, J; Meres, M; Miake, Y; Mikhaylov, K; Milano, L; Milosevic, J; Mischke, A; Mishra, A N; Miśkowiec, D; Mitu, C; Mizuno, S; Mlynarz, J; Mohanty, B; Molnar, L; Montaño Zetina, L; Monteno, M; Montes, E; Moon, T; Morando, M; Moreira De Godoy, D A; Moretto, S; Morreale, A; Morsch, A; Muccifora, V; Mudnic, E; Muhuri, S; Mukherjee, M; Müller, H; Munhoz, M G; Murray, S; Musa, L; Musinsky, J; Nandi, B K; Nania, R; Nappi, E; Nattrass, C; Nayak, T K; Nazarenko, S; Nedosekin, A; Nicassio, M; Niculescu, M; Nielsen, B S; Niida, T; Nikolaev, S; Nikolic, V; Nikulin, S; Nikulin, V; Nilsen, B S; Nilsson, M S; Noferini, F; Nomokonov, P; Nooren, G; Nyanin, A; Nyatha, A; Nygaard, C; Nystrand, J; Ochirov, A; Oeschler, H; Oh, S K; Oh, S; Oleniacz, J; Oliveira Da Silva, A C; Onderwaater, J; Oppedisano, C; Ortiz Velasquez, A; Ortona, G; Oskarsson, A; Ostrowski, P; Otwinowski, J; Oyama, K; Ozawa, K; Pachmayer, Y; Pachr, M; Padilla, F; Pagano, P; Paić, G; Painke, F; Pajares, C; Pal, S K; Palaha, A; Palmeri, A; Papikyan, V; Pappalardo, G S; Park, W J; Passfeld, A; Patalakha, D I; Paticchio, V; Paul, B; Pavlinov, A; Pawlak, T; Peitzmann, T; Pereira Da Costa, H; Pereira De Oliveira Filho, E; Peresunko, D; Pérez Lara, C E; Perrino, D; Peryt, W; Pesci, A; Pestov, Y; Petráček, V; Petran, M; Petris, M; Petrov, P; Petrovici, M; Petta, C; Piano, S; Pikna, M; Pillot, P; Pinazza, O; Pinsky, L; Pitz, N; Piyarathna, D B; Planinic, M; Płoskoń, M; Pluta, J; Pocheptsov, T; Pochybova, S; Podesta-Lerma, P L M; Poghosyan, M G; Polák, K; Polichtchouk, B; Poljak, N; Pop, A; Porteboeuf-Houssais, S; Pospíšil, V; Potukuchi, B; Prasad, S K; Preghenella, R; Prino, F; Pruneau, C A; Pshenichnov, I; Puddu, G; Punin, V; Putschke, J; Qvigstad, H; Rachevski, A; Rademakers, A; Rak, J; Rakotozafindrabe, A; Ramello, L; Raniwala, S; Raniwala, R; Räsänen, S S; Rascanu, B T; Rathee, D; Rauch, W; Rauf, A W; Razazi, V; Read, K F; Real, J S; Redlich, K; Reed, R J; Rehman, A; Reichelt, P; Reicher, M; Reidt, F; Renfordt, R; Reolon, A R; Reshetin, A; Rettig, F; Revol, J-P; Reygers, K; Riccati, L; Ricci, R A; Richert, T; Richter, M; Riedler, P; Riegler, W; Riggi, F; Rivetti, A; Rodríguez Cahuantzi, M; Rodriguez Manso, A; Røed, K; Rogochaya, E; Rohr, D; Röhrich, D; Romita, R; Ronchetti, F; Rosnet, P; Rossegger, S; Rossi, A; Roy, C; Roy, P; Rubio Montero, A J; Rui, R; Russo, R; Ryabinkin, E; Rybicki, A; Sadovsky, S; Šafařík, K; Sahoo, R; Sahu, P K; Saini, J; Sakaguchi, H; Sakai, S; Sakata, D; Salgado, C A; Salzwedel, J; Sambyal, S; Samsonov, V; Sanchez Castro, X; Šándor, L; Sandoval, A; Sano, M; Santagati, G; Santoro, R; Sarkar, D; Scapparone, E; Scarlassara, F; Scharenberg, R P; Schiaua, C; Schicker, R; Schmidt, C; Schmidt, H R; Schuchmann, S; Schukraft, J; Schuster, T; Schutz, Y; Schwarz, K; Schweda, K; Scioli, G; Scomparin, E; Scott, R; Scott, P A; Segato, G; Selyuzhenkov, I; Senyukov, S; Seo, J; Serci, S; Serradilla, E; Sevcenco, A; Shabetai, A; Shabratova, G; Shahoyan, R; Sharma, S; Sharma, N; Rohni, S; Shigaki, K; Shtejer, K; Sibiriak, Y; Siddhanta, S; Siemiarczuk, T; Silvermyr, D; Silvestre, C; Simatovic, G; Simonetti, G; Singaraju, R; Singh, R; Singha, S; Singhal, V; Sinha, T; Sinha, B C; Sitar, B; Sitta, M; Skaali, T B; Skjerdal, K; Smakal, R; Smirnov, N; Snellings, R J M; Søgaard, C; Soltz, R; Song, M; Song, J; Soos, C; Soramel, F; Sputowska, I; Spyropoulou-Stassinaki, M; Srivastava, B K; Stachel, J; Stan, I; Stefanek, G; Steinpreis, M; Stenlund, E; Steyn, G; Stiller, J H; Stocco, D; Stolpovskiy, M; Strmen, P; Suaide, A A P; Subieta Vásquez, M A; Sugitate, T; Suire, C; Suleymanov, M; Sultanov, R; Šumbera, M; Susa, T; Symons, T J M; Szanto de Toledo, A; Szarka, I; Szczepankiewicz, A; Szymański, M; Takahashi, J; Tangaro, M A; Tapia Takaki, J D; Tarantola Peloni, A; Tarazona Martinez, A; Tauro, A; Tejeda Muñoz, G; Telesca, A; Ter Minasyan, A; Terrevoli, C; Thäder, J; Thomas, D; Tieulent, R; Timmins, A R; Tlusty, D; Toia, A; Torii, H; Toscano, L; Trubnikov, V; Truesdale, D; Trzaska, W H; Tsuji, T; Tumkin, A; Turrisi, R; Tveter, T S; Ulery, J; Ullaland, K; Ulrich, J; Uras, A; Urciuoli, G M; Usai, G L; Vajzer, M; Vala, M; Valencia Palomo, L; Vallero, S; Vande Vyvre, P; Van Hoorne, J W; van Leeuwen, M; Vannucci, L; Vargas, A; Varma, R; Vasileiou, M; Vasiliev, A; Vechernin, V; Veldhoen, M; Venaruzzo, M; Vercellin, E; Vergara, S; Vernet, R; Verweij, M; Vickovic, L; Viesti, G; Viinikainen, J; Vilakazi, Z; Villalobos Baillie, O; Vinogradov, A; Vinogradov, Y; Vinogradov, L; Virgili, T; Viyogi, Y P; Vodopyanov, A; Völkl, M A; Voloshin, S; Voloshin, K; Volpe, G; von Haller, B; Vorobyev, I; Vranic, D; Vrláková, J; Vulpescu, B; Vyushin, A; Wagner, B; Wagner, V; Wang, Y; Wang, M; Wang, Y; Watanabe, K; Weber, M; Wessels, J P; Westerhoff, U; Wiechula, J; Wikne, J; Wilde, M; Wilk, G; Williams, M C S; Windelband, B; Winn, M; Yaldo, C G; Yamaguchi, Y; Yang, S; Yang, H; Yang, P; Yasnopolskiy, S; Yi, J; Yin, Z; Yoo, I-K; Yoon, J; Yuan, X; Yushmanov, I; Zaccolo, V; Zach, C; Zampolli, C; Zaporozhets, S; Zarochentsev, A; Závada, P; Zaviyalov, N; Zbroszczyk, H; Zelnicek, P; Zgura, I S; Zhalov, M; Zhang, Y; Zhang, H; Zhang, X; Zhou, D; Zhou, Y; Zhou, F; Zhu, H; Zhu, J; Zhu, X; Zhu, J; Zichichi, A; Zimmermann, A; Zinovjev, G; Zoccarato, Y; Zynovyev, M; Zyzak, M

    2013-09-01

    Azimuthally anisotropic distributions of D0, D+, and D*+ mesons were studied in the central rapidity region (|y|<0.8) in Pb-Pb collisions at a center-of-mass energy sqrt[sNN]=2.76  TeV per nucleon-nucleon collision, with the ALICE detector at the LHC. The second Fourier coefficient v2 (commonly denoted elliptic flow) was measured in the centrality class 30%-50% as a function of the D meson transverse momentum pT, in the range 2-16  GeV/c. The measured v2 of D mesons is comparable in magnitude to that of light-flavor hadrons. It is positive in the range 2

  16. Numerical solution of supersonic three-dimensional free-mixing flows using the parabolic-elliptic Navier-Stokes equations

    NASA Technical Reports Server (NTRS)

    Hirsh, R. S.

    1976-01-01

    A numerical method is presented for solving the parabolic-elliptic Navier-Stokes equations. The solution procedure is applied to three-dimensional supersonic laminar jet flow issuing parallel with a supersonic free stream. A coordinate transformation is introduced which maps the boundaries at infinity into a finite computational domain in order to eliminate difficulties associated with the imposition of free-stream boundary conditions. Results are presented for an approximate circular jet, a square jet, varying aspect ratio rectangular jets, and interacting square jets. The solution behavior varies from axisymmetric to nearly two-dimensional in character. For cases where comparisons of the present results with those obtained from shear layer calculations could be made, agreement was good.

  17. D Meson Elliptic Flow in Noncentral Pb-Pb Collisions at sNN=2.76TeV

    NASA Astrophysics Data System (ADS)

    Abelev, B.; Adam, J.; Adamová, D.; Adare, A. M.; Aggarwal, M. M.; Aglieri Rinella, G.; Agnello, M.; Agocs, A. G.; Agostinelli, A.; Ahammed, Z.; Ahmad, N.; Ahmad Masoodi, A.; Ahmed, I.; Ahn, S. U.; Ahn, S. A.; Aimo, I.; Ajaz, M.; Akindinov, A.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Alici, A.; Alkin, A.; Alme, J.; Alt, T.; Altini, V.; Altinpinar, S.; Altsybeev, I.; Andrei, C.; Andronic, A.; Anguelov, V.; Anielski, J.; Anson, C.; Antičić, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Arbor, N.; Arcelli, S.; Arend, A.; Armesto, N.; Arnaldi, R.; Aronsson, T.; Arsene, I. C.; Arslandok, M.; Asryan, A.; Augustinus, A.; Averbeck, R.; Awes, T. C.; Äystö, J.; Azmi, M. D.; Bach, M.; Badalà, A.; Baek, Y. W.; Bailhache, R.; Bala, R.; Baldisseri, A.; Baltasar Dos Santos Pedrosa, F.; Bán, J.; Baral, R. C.; Barbera, R.; Barile, F.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartke, J.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Batyunya, B.; Batzing, P. C.; Baumann, C.; Bearden, I. G.; Beck, H.; Behera, N. K.; Belikov, I.; Bellini, F.; Bellwied, R.; Belmont-Moreno, E.; Bencedi, G.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Bergognon, A. A. E.; Bertens, R. A.; Berzano, D.; Betev, L.; Bhasin, A.; Bhati, A. K.; Bhom, J.; Bianchi, N.; Bianchi, L.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Bjelogrlic, S.; Blanco, F.; Blanco, F.; Blau, D.; Blume, C.; Boccioli, M.; Böttger, S.; Bogdanov, A.; Bøggild, H.; Bogolyubsky, M.; Boldizsár, L.; Bombara, M.; Book, J.; Borel, H.; Borissov, A.; Bossú, F.; Botje, M.; Botta, E.; Braidot, E.; Braun-Munzinger, P.; Bregant, M.; Breitner, T.; Broker, T. A.; Browning, T. A.; Broz, M.; Brun, R.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buncic, P.; Busch, O.; Buthelezi, Z.; Caffarri, D.; Cai, X.; Caines, H.; Caliva, A.; Calvo Villar, E.; Camerini, P.; Canoa Roman, V.; Cara Romeo, G.; Carena, F.; Carena, W.; Carlin Filho, N.; Carminati, F.; Casanova Díaz, A.; Castillo Castellanos, J.; Castillo Hernandez, J. F.; Casula, E. A. R.; Catanescu, V.; Cavicchioli, C.; Ceballos Sanchez, C.; Cepila, J.; Cerello, P.; Chang, B.; Chapeland, S.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chibante Barroso, V.; Chinellato, D. D.; Chochula, P.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Conesa Balbastre, G.; Conesa del Valle, Z.; Connors, M. E.; Contin, G.; Contreras, J. G.; Cormier, T. M.; Corrales Morales, Y.; Cortese, P.; Cortés Maldonado, I.; Cosentino, M. R.; Costa, F.; Cotallo, M. E.; Crescio, E.; Crochet, P.; Cruz Alaniz, E.; Cruz Albino, R.; Cuautle, E.; Cunqueiro, L.; Dainese, A.; Dang, R.; Danu, A.; Das, S.; Das, K.; Das, I.; Das, D.; Dash, S.; Dash, A.; De, S.; de Barros, G. O. V.; De Caro, A.; de Cataldo, G.; de Cuveland, J.; De Falco, A.; De Gruttola, D.; Delagrange, H.; Deloff, A.; De Marco, N.; Dénes, E.; De Pasquale, S.; Deppman, A.; D'Erasmo, G.; de Rooij, R.; Diaz Corchero, M. A.; Di Bari, D.; Dietel, T.; Di Giglio, C.; Di Liberto, S.; Di Mauro, A.; Di Nezza, P.; Divià, R.; Djuvsland, Ø.; Dobrin, A.; Dobrowolski, T.; Dönigus, B.; Dordic, O.; Dubey, A. K.; Dubla, A.; Ducroux, L.; Dupieux, P.; Dutta Majumdar, A. K.; Elia, D.; Elwood, B. G.; Emschermann, D.; Engel, H.; Erazmus, B.; Erdal, H. A.; Eschweiler, D.; Espagnon, B.; Estienne, M.; Esumi, S.; Evans, D.; Evdokimov, S.; Eyyubova, G.; Fabris, D.; Faivre, J.; Falchieri, D.; Fantoni, A.; Fasel, M.; Fehlker, D.; Feldkamp, L.; Felea, D.; Feliciello, A.; Fenton-Olsen, B.; Feofilov, G.; Fernández Téllez, A.; Ferretti, A.; Festanti, A.; Figiel, J.; Figueredo, M. A. S.; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Floratos, E.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; Frankenfeld, U.; Fuchs, U.; Furget, C.; Fusco Girard, M.; Gaardhøje, J. J.; Gagliardi, M.; Gago, A.; Gallio, M.; Gangadharan, D. R.; Ganoti, P.; Garabatos, C.; Garcia-Solis, E.; Gargiulo, C.; Garishvili, I.; Gerhard, J.; Germain, M.; Geuna, C.; Gheata, A.; Gheata, M.; Ghidini, B.; Ghosh, P.; Gianotti, P.; Giubellino, P.; Gladysz-Dziadus, E.; Glässel, P.; Goerlich, L.; Gomez, R.; Ferreiro, E. G.; González-Zamora, P.; Gorbunov, S.; Goswami, A.; Gotovac, S.; Graczykowski, L. K.; Grajcarek, R.; Grelli, A.; Grigoras, C.; Grigoras, A.; Grigoriev, V.; Grigoryan, S.; Grigoryan, A.; Grinyov, B.; Grion, N.; Gros, P.; Grosse-Oetringhaus, J. F.; Grossiord, J.-Y.; Grosso, R.; Guber, F.; Guernane, R.; Guerzoni, B.; Guilbaud, M.; Gulbrandsen, K.; Gulkanyan, H.; Gunji, T.

    2013-09-01

    Azimuthally anisotropic distributions of D0, D+, and D*+ mesons were studied in the central rapidity region (|y|<0.8) in Pb-Pb collisions at a center-of-mass energy sNN=2.76TeV per nucleon-nucleon collision, with the ALICE detector at the LHC. The second Fourier coefficient v2 (commonly denoted elliptic flow) was measured in the centrality class 30%-50% as a function of the D meson transverse momentum pT, in the range 2-16GeV/c. The measured v2 of D mesons is comparable in magnitude to that of light-flavor hadrons. It is positive in the range 2

  18. Elliptic flow of charged particles in Pb-Pb collisions at sqrt[S(NN)] = 2.76 TeV.

    PubMed

    Aamodt, K; Abelev, B; Quintana, A Abrahantes; Adamová, D; Adare, A M; Aggarwal, M M; Rinella, G Aglieri; Agocs, A G; Salazar, S Aguilar; Ahammed, Z; Masoodi, A Ahmad; Ahmad, N; Ahn, S U; Akindinov, A; Aleksandrov, D; Alessandro, B; Molina, R Alfaro; Alici, A; Alkin, A; Aviña, E Almaráz; Alt, T; Altini, V; Altinpinar, S; Altsybeev, I; Andrei, C; Andronic, A; Anguelov, V; Anson, C; Antičić, T; Antinori, F; Antonioli, P; Aphecetche, L; Appelshäuser, H; Arbor, N; Arcelli, S; Arend, A; Armesto, N; Arnaldi, R; Aronsson, T; Arsene, I C; Asryan, A; Augustinus, A; Averbeck, R; Awes, T C; Aystö, J; Azmi, M D; Bach, M; Badalà, A; Baek, Y W; Bagnasco, S; Bailhache, R; Bala, R; Ferroli, R Baldini; Baldisseri, A; Baldit, A; Pedrosa, F Baltasar Dos Santos; Bán, J; Barbera, R; Barile, F; Barnaföldi, G G; Barnby, L S; Barret, V; Bartke, J; Basile, M; Bastid, N; Bathen, B; Batigne, G; Batyunya, B; Baumann, C; Bearden, I G; Beck, H; Belikov, I; Bellini, F; Bellwied, R; Belmont-Moreno, E; Beole, S; Berceanu, I; 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Yushmanov, I; Zabrodin, E; Zach, C; Zampolli, C; Zaporozhets, S; Zarochentsev, A; Závada, P; Zaviyalov, N; Zbroszczyk, H; Zelnicek, P; Zenin, A; Zgura, I; Zhalov, M; Zhang, X; Zhou, D; Zichichi, A; Zinovjev, G; Zoccarato, Y; Zynovyev, M

    2010-12-17

    We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at sqrt[S(NN)] =2.76 TeV with the ALICE detector at the CERN Large Hadron Collider. The measurement is performed in the central pseudorapidity region (|η|<0.8) and transverse momentum range 0.2

    elliptic flow signal v₂, measured using the 4-particle correlation method, averaged over transverse momentum and pseudorapidity is 0.087 ± 0.002(stat) ± 0.003(syst) in the 40%-50% centrality class. The differential elliptic flow v₂ p t reaches a maximum of 0.2 near p t =3 GeV/c. Compared to RHIC Au-Au collisions at sqrt[S(NN)] 200 GeV, the elliptic flow increases by about 30%. Some hydrodynamic model predictions which include viscous corrections are in agreement with the observed increase. PMID:21231580

  19. Jet quenching effects on the direct, elliptic, and triangular flow at energies available at the BNL Relativistic Heavy Ion Collider

    NASA Astrophysics Data System (ADS)

    Andrade, R. P. G.; Noronha, J.; Denicol, Gabriel S.

    2014-08-01

    In this paper we investigate how the energy and momentum deposited by partonic dijets in the quark-gluon plasma (QGP) may affect the direct, elliptic, and triangular flow of low (and intermediate) pT hadrons in central Au +Au collisions at the BNL Relativistic Heavy Ion Collider. The dijets are modeled as external sources in the energy-momentum conservation equations for hydrodynamics, which are solved on an event-by-event basis within the ideal-fluid approximation. We focus our investigation at midrapidity and solve the hydrodynamic equations by imposing boost invariance. Differential anisotropic flow coefficients for pT≳1GeV are found to be significantly enhanced if the dijets deposit on average more than 12 GeV in the QGP (or more than 6 GeV per jet). Because this extra energy and momentum added to the medium perturbs the geometry-induced hydrodynamic expansion, the correlation between the v2 and v3 coefficients (for pT≳1GeV) and their corresponding initial eccentricities are considerably weakened. In addition, we argue that the extra amount of direct flow induced by dijets may be quantified by comparing the azimuthal dependence of dihadron correlations in dijet events with the corresponding quantity obtained in events without dijets. This comparison could be used to give a rough estimate of the magnitude of the effective coupling between the jets and the medium.

  20. Simulation of 2-dimensional viscous flow through cascades using a semi-elliptic analysis and hybrid C-H grids

    NASA Technical Reports Server (NTRS)

    Ramamurti, R.; Ghia, U.; Ghia, K. N.

    1988-01-01

    A semi-elliptic formulation, termed the interacting parabolized Navier-Stokes (IPNS) formulation, is developed for the analysis of a class of subsonic viscous flows for which streamwise diffusion is neglible but which are significantly influenced by upstream interactions. The IPNS equations are obtained from the Navier-Stokes equations by dropping the streamwise viscous-diffusion terms but retaining upstream influence via the streamwise pressure-gradient. A two-step alternating-direction-explicit numerical scheme is developed to solve these equations. The quasi-linearization and discretization of the equations are carefully examined so that no artificial viscosity is added externally to the scheme. Also, solutions to compressible as well as nearly compressible flows are obtained without any modification either in the analysis or in the solution process. The procedure is applied to constricted channels and cascade passages formed by airfoils of various shapes. These geometries are represented using numerically generated curilinear boundary-oriented coordinates forming an H-grid. A hybrid C-H grid, more appropriate for cascade of airfoils with rounded leading edges, was also developed. Satisfactory results are obtained for flows through cascades of Joukowski airfoils.

  1. Analysis of a parallelized nonlinear elliptic boundary value problem solver with application to reacting flows

    NASA Technical Reports Server (NTRS)

    Keyes, David E.; Smooke, Mitchell D.

    1987-01-01

    A parallelized finite difference code based on the Newton method for systems of nonlinear elliptic boundary value problems in two dimensions is analyzed in terms of computational complexity and parallel efficiency. An approximate cost function depending on 15 dimensionless parameters is derived for algorithms based on stripwise and boxwise decompositions of the domain and a one-to-one assignment of the strip or box subdomains to processors. The sensitivity of the cost functions to the parameters is explored in regions of parameter space corresponding to model small-order systems with inexpensive function evaluations and also a coupled system of nineteen equations with very expensive function evaluations. The algorithm was implemented on the Intel Hypercube, and some experimental results for the model problems with stripwise decompositions are presented and compared with the theory. In the context of computational combustion problems, multiprocessors of either message-passing or shared-memory type may be employed with stripwise decompositions to realize speedup of O(n), where n is mesh resolution in one direction, for reasonable n.

  2. Flow angle dependent photoacoustic Doppler power spectra under intensity-modulated continuous wave laser excitation

    NASA Astrophysics Data System (ADS)

    Tong, Yu; Zhao, Hongcai; Fang, Hui; Zhao, Youquan; Yuan, Xiaocong

    2016-02-01

    Photoacoustic Doppler (PAD) power spectra showing an evident Doppler shift represent the major characteristics of the continuous wave-excited or burst wave-excited versions of PAD flow measurements. In this paper, the flow angle dependences of the PAD power spectra are investigated using an experiment setup that was established based on intensity-modulated continuous wave laser excitation. The setup has an overall configuration that is similar to a previously reported configuration, but is more sophisticated in that it accurately aligns the laser illumination with the ultrasound detection process, and in that it picks up the correct sample position. In the analysis of the power spectra data, we find that the background power spectra can be extracted by combining the output signals from the two channels of the lock-in amplifier, which is very useful for identification of the PAD power spectra. The power spectra are presented and analyzed in opposite flow directions, at different flow speeds, and at different flow angles. The power spectra at a 90° flow angle show the unique properties of symmetrical shapes due to PAD broadening. For the other flow angles, the smoothed power spectra clearly show a flow angle cosine relationship.

  3. Elliptic flow computation by low Reynolds number two-equation turbulence models

    NASA Technical Reports Server (NTRS)

    Michelassi, V.; Shih, T.-H.

    1991-01-01

    A detailed comparison of ten low-Reynolds-number k-epsilon models is carried out. The flow solver, based on an implicit approximate factorization method, is designed for incompressible, steady two-dimensional flows. The conservation of mass is enforced by the artificial compressibility approach and the computational domain is discretized using centered finite differences. The turbulence model predictions of the flow past a hill are compared with experiments at Re = 10 exp 6. The effects of the grid spacing together with the numerical efficiency of the various formulations are investigated. The results show that the models provide a satisfactory prediction of the flow field in the presence of a favorable pressure gradient, while the accuracy rapidly deteriorates when a strong adverse pressure gradient is encountered. A newly proposed model form that does not explicitly depend on the wall distance seems promising for application to complex geometries.

  4. Fully elliptic incompressible flow calculations on regular grid by a new pressure substitution method

    NASA Technical Reports Server (NTRS)

    Hobson, G. V.; Lakshminarayana, B.

    1990-01-01

    A new method is presented for the solution of incompressible flow in generalized coordinates. This method is based on the substitution of the pressure weighted form of the momentum equations into the continuity equation. The algorithm is rigorously derived and a Fourier analysis is used to assess its suitability to act as an error smoother. Linear stability analysis results indicate that the performance of the new pressure substitution method (PSM) and the pressure correction method (PCM) is about the same at low Reynolds numbers, with no significant pressure gradient. At high Reynolds numbers the PSM shows much faster convergence. Likewise prediction of various flows indicate that the PSM has better accuracy for high Reynolds number flows with significant pressure gradients. Since most practical aerodynamic flows have significant pressure gradients, the PSM seems to be attractive for such flows. Solutions for both laminar and turbulent flow are compared with the experimental data. A two-equation low Reynolds number turbulence model is used to resolve the turbulent flowfield.

  5. Elliptic and Hexadecapole Flow of Charged Hadrons in Au+Au Collisions at s_NN = 200 GeV

    SciTech Connect

    Adare, A.; Awes, Terry C; Cianciolo, Vince; Efremenko, Yuri; Enokizono, Akitomo; Read Jr, Kenneth F; Silvermyr, David O; Sorensen, Soren P; Stankus, Paul W; PHENIX, Collaboration

    2010-01-01

    Differential measurements of the elliptic (v{sub 2}) and hexadecapole (v{sub 4}) Fourier flow coefficients are reported for charged hadrons as a function of transverse momentum (p{sub T}) and collision centrality or number of participant nucleons (N{sub part}) for Au+Au collisions at {radical}s{sub NN} = 200 GeV. The v{sub 2,4} measurements at pseudorapidity |{eta}| {le} 0.35, obtained with four separate reaction-plane detectors positioned in the range 1.0 < |{eta}| < 3.9, show good agreement, indicating the absence of significant {Delta}{eta}-dependent nonflow correlations. Sizable values for v{sub 4}(p{sub T}) are observed with a ratio v{sub 4}(p{sub T},N{sub part})/v{sub 2}{sup 2}(p{sub T},N{sub part}) {approx} 0.8 for 50 {le} N{sub part} {le} 200, which is compatible with the combined effects of a finite viscosity and initial eccentricity fluctuations. For N{sub part} {ge} 200 this ratio increases up to 1.7 in the most central collisions.

  6. Elliptic flow and nuclear modification factor in ultrarelativistic heavy-ion collisions within a partonic transport model.

    PubMed

    Uphoff, Jan; Senzel, Florian; Fochler, Oliver; Wesp, Christian; Xu, Zhe; Greiner, Carsten

    2015-03-20

    The quark gluon plasma produced in ultrarelativistic heavy-ion collisions exhibits remarkable features. It behaves like a nearly perfect liquid with a small shear viscosity to entropy density ratio and leads to the quenching of highly energetic particles. We show that both effects can be understood for the first time within one common framework. Employing the parton cascade Boltzmann approach to multiparton scatterings, the microscopic interactions and the space-time evolution of the quark gluon plasma are calculated by solving the relativistic Boltzmann equation. Based on cross sections obtained from perturbative QCD with explicitly taking the running coupling into account, we calculate the nuclear modification factor and elliptic flow in ultrarelativistic heavy-ion collisions. With only one single parameter associated with coherence effects of medium-induced gluon radiation, the experimental data of both observables can be understood on a microscopic level. Furthermore, we show that perturbative QCD interactions with a running coupling lead to a sufficiently small shear viscosity to entropy density ratio of the quark gluon plasma, which provides a microscopic explanation for the observations stated by hydrodynamic calculations. PMID:25839262

  7. Predictions of Elliptic flow and nuclear modification factor from 200 GeV U+U collisions at RHIC

    SciTech Connect

    Masui, Hiroshi; Mohanty, Bedangadas; Xu, Nu

    2010-07-07

    Predictions of elliptic flow (v{sub 2}) and nuclear modification factor (R{sub AA}) are provided as a function of centrality in U + U collisions at {radical}s{sub NN} = 200 GeV. Since the {sup 238}U nucleus is naturally deformed, one could adjust the properties of the fireball, density and duration of the hot and dense system, for example, in high energy nuclear collisions by carefully selecting the colliding geometry. Within our Monte Carlo Glauber based approach, the v{sub 2} with respect to the reaction plane v{sub 2}{sup RP} in U + U collisions is consistent with that in Au + Au collisions, while the v{sub 2} with respect to the participant plane v{sub 2}{sup PP} increases {approx}30-60% at top 10% centrality which is attributed to the larger participant eccentricity at most central U + U collisions. The suppression of R{sub AA} increases and reaches {approx}0.1 at most central U + U collisions that is by a factor of 2 more suppression compared to the central Au + Au collisions due to large size and deformation of Uranium nucleus.

  8. Scaling of elliptic flow in heavy-ion collisions with the number of constituent quarks in a transport model

    NASA Astrophysics Data System (ADS)

    Singha, Subhash; Nasim, Md.

    2016-03-01

    We studied the number of constituent quark scaling (NCQ) behavior of elliptic flow (v2) under the framework of a multiphase transport model (AMPT) at both top-RHIC and LHC energies. The NCQ-scaling in v2 holds at top RHIC energy with AMPT string melting version, while it breaks in Pb+Pb collisions at LHC energy using the same framework. The breaking of NCQ scaling at LHC energy has been studied by varying the magnitude of parton-parton scattering cross sections and lifetime of hadronic cascade as implemented in AMPT. We find that the breaking of NCQ scaling in Pb+Pb collisions at √{sNN}=2.76 TeV is independent of the magnitude of parton-parton cross sections and the later stage hadronic interactions. Further we observed that scaling holds in a small collision system like Si+Si at √{sNN}=2.76 TeV. We discussed that the breaking of NCQ scaling is possibly due to high phase-space density of constituents quarks in Pb+Pb collisions at √{sNN}=2.76 TeV.

  9. Turbulence spectra in the noise source regions of the flow around complex surfaces

    NASA Technical Reports Server (NTRS)

    Olsen, W. A.; Boldman, D. R.

    1983-01-01

    The complex turbulent flow around three complex surfaces was measured in detail with a hot wire. The measured data include extensive spatial surveys of the mean velocity and turbulence intensity and measurements of the turbulence spectra and scale length at many locations. The publication of the turbulence data is completed by reporting a summary of the turbulence spectra that were measured within the noise source locations of the flow. The results suggest some useful simplifications in modeling the very complex turbulent flow around complex surfaces for aeroacoustic predictive models. The turbulence spectra also show that noise data from scale models of moderate size can be accurately scaled up to full size.

  10. Elliptic flow in Pb+Pb collisions at sNN = 2.76 TeV: Hybrid model assessment of the first data

    NASA Astrophysics Data System (ADS)

    Hirano, Tetsufumi; Huovinen, Pasi; Nara, Yasushi

    2011-07-01

    We analyze the elliptic flow parameter v2 in Pb+Pb collisions at sNN = 2.76 TeV and in Au+Au collisions at sNN=200 GeV using a hybrid model in which the evolution of the quark gluon plasma is described by ideal hydrodynamics with a state-of-the-art lattice QCD equation of state, and the subsequent hadronic stage by a hadron cascade model. For initial conditions, we employ Monte Carlo versions of the Glauber and the Kharzeev-Levin-Nardi models and compare results with each other. We demonstrate that the differential elliptic flow v2(pT) hardly changes when the collision energy increases, whereas the integrated v2 increases due to the enhancement of mean transverse momentum. The amount of increase of both v2 and mean pT depends significantly on the model of initialization.

  11. Methods for Determining Elliptic Flow of Isolated Photons and π0's

    NASA Astrophysics Data System (ADS)

    Danley, Tyler; Phenix Collaboration

    2015-04-01

    We present methods for measurements of second order flow coefficients and derivations of reaction plane dependent efficiencies of isolated photons and π0's in Relativistic Heavy Ion Collisions. The method involves isolation cuts similar to those used in direct photon identification where the energy is summed inside an angular cone and cut if greater than a threshold energy. We show that this will result in a reaction plane dependent efficiency. We derive and verify azimuthal single and two particle correlation functions, including this efficiency, up to harmonic second order. We show that the standard v2 extraction method is only sensitive to an effective v2, which includes the sum of true v2 and the v2 of the isolation efficiency, which is generally negative. We will also present the status of applying these methods to PHENIX √{sNN} = 200GeV Au+Au data. for the PHENIX Collaboration.

  12. A Gas-Kinetic Method for Hyperbolic-Elliptic Equations and Its Application in Two-Phase Fluid Flow

    NASA Technical Reports Server (NTRS)

    Xu, Kun

    1999-01-01

    A gas-kinetic method for the hyperbolic-elliptic equations is presented in this paper. In the mixed type system, the co-existence and the phase transition between liquid and gas are described by the van der Waals-type equation of state (EOS). Due to the unstable mechanism for a fluid in the elliptic region, interface between the liquid and gas can be kept sharp through the condensation and evaporation process to remove the "averaged" numerical fluid away from the elliptic region, and the interface thickness depends on the numerical diffusion and stiffness of the phase change. A few examples are presented in this paper for both phase transition and multifluid interface problems.

  13. Turbulence and turbulence spectra in complex fluid flows

    SciTech Connect

    Clark, T.T.; Chen, Shi-Yi; Turner, L.; Zemach, C.

    1997-11-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). Our objective was to develop a theoretical model of fluid turbulence in parallel with a series of direct numerical simulations of increasingly complex test environments to establish limits of error and regimes of applicability, and to guide improvements. The aim is to produce methods of tested accuracy, with tractable numerical approximations, for turbulent fluids of constant density, and then for variable densities and multimaterial flows. We proceed from a recent spectral model that describes turbulent energy and stress densities in terms of a range of length scales. This should lead not only to improved engineering models, but also to a basic conceptual improvement because the spectral approach accounts for the variation of evolution rates with turbulence length scales.

  14. Multi-scale roughness spectra of Mount St. Helens debris flows

    NASA Technical Reports Server (NTRS)

    Austin, Richard T.; England, Anthony W.

    1993-01-01

    A roughness spectrum allows surface structure to be interpreted as a sum of sinusoidal components with differing wavelengths. Knowledge of the roughness spectrum gives insight into the mechanisms responsible for electromagnetic scattering at a given wavelength. Measured spectra from 10-year-old primary debris flow surfaces at Mount St. Helens conform to a power-law spectral model, suggesting that these surfaces are scaling over the measured range of spatial frequencies. Measured spectra from water-deposited surfaces deviate from this model.

  15. Energy Dependence of Elliptic Flow over a Large Pseudorapidity Range in Au+Au Collisions at the BNL Relativistic Heavy Ion Collider

    NASA Astrophysics Data System (ADS)

    Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Chai, Z.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Hauer, M.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Seals, H.; Sedykh, I.; Skulski, W.; Smith, C. E.; Stankiewicz, M. A.; Steinberg, P.; Stephans, G. S.; Sukhanov, A.; Tang, J.-L.; Tonjes, M. B.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Vaurynovich, S. S.; Verdier, R.; Veres, G. I.; Wenger, E.; Wolfs, F. L.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

    2005-04-01

    This Letter describes the measurement of the energy dependence of elliptic flow for charged particles in Au+Au collisions using the PHOBOS detector at the Relativistic Heavy Ion Collider. Data taken at collision energies of √(sNN)=19.6, 62.4, 130, and 200 GeV are shown over a wide range in pseudorapidity. These results, when plotted as a function of η'=|η|-ybeam, scale with approximate linearity throughout η', implying no sharp changes in the dynamics of particle production as a function of pseudorapidity or increasing beam energy.

  16. Charged and strange hadron elliptic flow in Cu+Cu collisions at sqrt sNN = 62.4 and 200 GeV

    SciTech Connect

    STAR Collaboration; Abelev, Betty

    2010-07-05

    We present the results of an elliptic flow, v{sub 2}, analysis of Cu+Cu collisions recorded with the STAR detector at RHIC at {radical}s{sub NN} = 62.4 and 200 GeV. Elliptic flow as a function of transverse momentum, v{sub 2}(p{sub T}), is reported for different collision centralities for charged hadrons h{sup {+-}}, and strangeness containing hadrons K{sub S}{sup 0}, {Lambda}, {Xi}, {phi} in the midrapidity region |{eta}| < 1.0. Significant reduction in systematic uncertainty of the measurement due to non-flow effects has been achieved by correlating particles at midrapidity, |{eta}| < 1.0, with those at forward rapidity, 2.5 < |{eta}| < 4.0. We also present azimuthal correlations in p+p collisions at {radical}s = 200 GeV to help estimating non-flow effects. To study the system-size dependence of elliptic flow, we present a detailed comparison with previously published results from Au+Au collisions at {radical}s{sub NN} = 200 GeV. We observe that v{sub 2}(p{sub T}) of strange hadrons has similar scaling properties as were first observed in Au+Au collisions, i.e.: (i) at low transverse momenta, p{sub T} < 2 GeV/c, v{sub 2} scales with transverse kinetic energy, m{sub T} - m, and (ii) at intermediate p{sub T}, 2 < p{sub T} < 4 GeV/c, it scales with the number of constituent quarks, n{sub q}. We have found that ideal hydrodynamic calculations fail to reproduce the centrality dependence of v{sub 2}(p{sub T}) for K{sub S}{sup 0} and {Lambda}. Eccentricity scaled v{sub 2} values, v{sub 2}/{var_epsilon}, are larger in more central collisions, suggesting stronger collective flow develops in more central collisions. The comparison with Au+Au collisions which go further in density shows v{sub 2}/{var_epsilon} depend on the system size, number of participants N{sub part}. This indicates that the ideal hydrodynamic limit is not reached in Cu+Cu collisions, presumably because the assumption of thermalization is not attained.

  17. Elliptic flow in heavy-ion collisions at energies √{sN N}=2.7 - 39 GeV

    NASA Astrophysics Data System (ADS)

    Ivanov, Yu. B.; Soldatov, A. A.

    2015-02-01

    The transverse-momentum-integrated elliptic flow of charged particles at midrapidity, v2(charged), and that of identified hadrons from Au +Au collisions are computed in a wide range of incident energies 2.7 ≤√{sN N}≤ 39 GeV. The simulations are performed within a three-fluid model by employing three different equations of state (EoSs): a purely hadronic EoS and two versions of the EoS involving the deconfinement transition—a first-order phase transition and a smooth crossover one. The present simulations demonstrate low sensitivity of v2(charged) to the EoS. All considered scenarios equally well reproduce recent STAR data on v2(charged) for mid-central Au +Au collisions and properly describe its change of sign at the incident energy decrease below √{sN N}≈ 3.5 GeV. The predicted integrated elliptic flow of various species exhibits a stronger dependence on the EoS. A noticeable sensitivity to the EoS is found for antibaryons and, to a lesser extent, for K- mesons. In particular, the v2 excitation functions of antibaryons exhibit a nonmonotonicity within the deconfinement scenarios that was predicted by Kolb, Sollfrank, and Heinz. However, low multiplicities of antibaryons at √{sN N}≤ 10 GeV result in large fluctuations of their v2, which may wash out this nonmonotonicity.

  18. Measurements of elliptic and triangular flow in high-multiplicity 3He+Au collisions at √sNN=200 GeV

    DOE PAGESBeta

    Adare, A.

    2015-09-28

    We present the first measurement of elliptic (v2) and triangular (v3) flow in high-multiplicity 3He+Aucollisions at √sNN=200 GeV. Two-particle correlations, where the particles have a large separation in pseudorapidity, are compared in 3He+Au and in p+p collisions and indicate that collective effects dominate the second and third Fourier components for the correlations observed in the 3He+Ausystem. The collective behavior is quantified in terms of elliptic v2 and triangular v3 anisotropy coefficients measured with respect to their corresponding event planes. The v2 values are comparable to those previously measured in d+Au collisions at the same nucleon-nucleon center-of-mass energy. Comparisons with variousmore » theoretical predictions are made, including to models where the hot spots created by the impact of the three 3He nucleons on the Au nucleus expand hydrodynamically to generate the triangular flow. The agreement of these models with data may indicate the formation of low-viscosity quark-gluon plasma even in these small collision systems.« less

  19. Measurements of Elliptic and Triangular Flow in High-Multiplicity 3He+Au Collisions at √(s(NN))=200 GeV.

    PubMed

    Adare, A; Afanasiev, S; Aidala, C; Ajitanand, N N; Akiba, Y; Akimoto, R; Al-Bataineh, H; Alexander, J; Alfred, M; Al-Ta'ani, H; Andrews, K R; Angerami, A; Aoki, K; Apadula, N; Aphecetche, L; Appelt, E; Aramaki, Y; Armendariz, R; Aronson, S H; Asai, J; Asano, H; Aschenauer, E C; Atomssa, E T; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Bai, M; Baksay, G; Baksay, L; Baldisseri, A; Bandara, N S; Bannier, B; Barish, K N; Barnes, P D; Bassalleck, B; Basye, A T; Bathe, S; Batsouli, S; Baublis, V; Baumann, C; Bazilevsky, A; Beaumier, M; Beckman, S; Belikov, S; Belmont, R; Ben-Benjamin, J; Bennett, R; Berdnikov, A; Berdnikov, Y; Bhom, J H; Bickley, A A; Blau, D S; Boissevain, J G; Bok, J S; Borel, H; Boyle, K; Brooks, M L; Broxmeyer, D; Bryslawskyj, J; Buesching, H; Bumazhnov, V; Bunce, G; Butsyk, S; Camacho, C M; Campbell, S; Caringi, A; Castera, P; Chang, B S; Chang, W C; Charvet, J-L; Chen, C-H; Chernichenko, S; Chi, C Y; Chiba, J; Chiu, M; Choi, I J; Choi, J B; Choudhury, R K; Christiansen, P; Chujo, T; Chung, P; Churyn, A; Chvala, O; Cianciolo, V; Citron, Z; Cleven, C R; Cole, B A; Comets, M P; Conesa del Valle, Z; Connors, M; Constantin, P; Csanád, M; Csörgő, T; Dahms, T; Dairaku, S; Danchev, I; Danley, D; Das, K; Datta, A; Daugherity, M S; David, G; Dayananda, M K; Deaton, M B; DeBlasio, K; Dehmelt, K; Delagrange, H; Denisov, A; d'Enterria, D; Deshpande, A; Desmond, E J; Dharmawardane, K V; Dietzsch, O; Dion, A; Diss, P B; Do, J H; Donadelli, M; D'Orazio, L; Drapier, O; Drees, A; Drees, K A; Dubey, A K; Durham, J M; Durum, A; Dutta, D; Dzhordzhadze, V; Edwards, S; Efremenko, Y V; Egdemir, J; Ellinghaus, F; Emam, W S; Engelmore, T; Enokizono, A; En'yo, H; Esumi, S; Eyser, K O; Fadem, B; Feege, N; Fields, D E; Finger, M; Finger, M; Fleuret, F; Fokin, S L; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fujiwara, K; Fukao, Y; Fusayasu, T; Gadrat, S; Gal, C; Gallus, P; Garg, P; Garishvili, I; Ge, H; Giordano, F; Glenn, A; Gong, H; Gong, X; Gonin, M; Gosset, J; Goto, Y; Granier de Cassagnac, R; Grau, N; Greene, S V; Grim, G; Grosse Perdekamp, M; Gu, Y; Gunji, T; Guo, L; Gustafsson, H-Å; Hachiya, T; Hadj Henni, A; Haegemann, C; Haggerty, J S; Hahn, K I; Hamagaki, H; Hamblen, J; Hamilton, H F; Han, R; Han, S Y; Hanks, J; Harada, H; Harper, C; Hartouni, E P; Haruna, K; Hasegawa, S; Haseler, T O S; Hashimoto, K; Haslum, E; Hayano, R; He, X; Heffner, M; Hemmick, T K; Hester, T; Hiejima, H; Hill, J C; Hobbs, R; Hohlmann, M; Hollis, R S; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hori, Y; Hornback, D; Hoshino, T; Hotvedt, N; Huang, J; Huang, S; Ichihara, T; Ichimiya, R; Iinuma, H; Ikeda, Y; Imai, K; Imrek, J; Inaba, M; Inoue, Y; Iordanova, A; Isenhower, D; Isenhower, L; Ishihara, M; Isobe, T; Issah, M; Isupov, A; Ivanishchev, D; Iwanaga, Y; Jacak, B V; Jezghani, M; Jia, J; Jiang, X; Jin, J; Jinnouchi, O; John, D; Johnson, B M; Jones, T; Joo, K S; Jouan, D; Jumper, D S; Kajihara, F; Kametani, S; Kamihara, N; Kamin, J; Kanda, S; Kaneta, M; Kaneti, S; Kang, B H; Kang, J H; Kang, J S; Kanou, H; Kapustinsky, J; Karatsu, K; Kasai, M; Kawall, D; Kawashima, M; Kazantsev, A V; Kempel, T; Key, J A; Khachatryan, V; Khanzadeev, A; Kijima, K M; Kikuchi, J; Kim, A; Kim, B I; Kim, C; Kim, D H; Kim, D J; Kim, E; Kim, E-J; Kim, G W; Kim, M; Kim, S H; Kim, Y-J; Kim, Y K; Kimelman, B; Kinney, E; Kiriluk, K; Kiss, Á; Kistenev, E; Kitamura, R; Kiyomichi, A; Klatsky, J; Klay, J; Klein-Boesing, C; Kleinjan, D; Kline, P; Koblesky, T; Kochenda, L; Kochetkov, V; Komkov, B; Konno, M; Koster, J; Kotchetkov, D; Kotov, D; Kozlov, A; Král, A; Kravitz, A; Kubart, J; Kunde, G J; Kurihara, N; Kurita, K; Kurosawa, M; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y S; Lajoie, J G; Layton, D; Lebedev, A; Lee, D M; Lee, J; Lee, K B; Lee, K S; Lee, M K; Lee, S; Lee, S H; Lee, S R; Lee, T; Leitch, M J; Leite, M A L; Lenzi, B; Li, X; Lichtenwalner, P; Liebing, P; Lim, S H; Linden Levy, L A; Liška, T; Litvinenko, A; Liu, H; Liu, M X; Love, B; Lynch, D; Maguire, C F; Makdisi, Y I; Makek, M; Malakhov, A; Malik, M D; Manion, A; Manko, V I; Mannel, E; Mao, Y; Mašek, L; Masui, H; Matathias, F; McCumber, M; McGaughey, P L; McGlinchey, D; McKinney, C; Means, N; Meles, A; Mendoza, M; Meredith, B; Miake, Y; Mibe, T; Mignerey, A C; Mikeš, P; Miki, K; Miller, T E; Milov, A; Mioduszewski, S; Mishra, D K; Mishra, M; Mitchell, J T; Mitrovski, M; Miyachi, Y; Miyasaka, S; Mizuno, S; Mohanty, A K; Montuenga, P; Moon, H J; Moon, T; Morino, Y; Morreale, A; Morrison, D P; Motschwiller, S; Moukhanova, T V; Mukhopadhyay, D; Murakami, T; Murata, J; Mwai, A; Nagamiya, S; Nagashima, K; Nagata, Y; Nagle, J L; Naglis, M; Nagy, M I; Nakagawa, I; Nakagomi, H; Nakamiya, Y; Nakamura, K R; Nakamura, T; Nakano, K; Nam, S; Nattrass, C; Netrakanti, P K; Newby, J; Nguyen, M; Nihashi, M; Niida, T; Nishimura, S; Norman, B E; Nouicer, R; Novak, T; Novitzky, N; Nyanin, A S; Oakley, C; O'Brien, E; Oda, S X; Ogilvie, C A; Ohnishi, H; Oka, M; Okada, K; Omiwade, O O; Onuki, Y; Orjuela Koop, J D; Osborn, J D; Oskarsson, A; Ouchida, M; Ozawa, K; Pak, R; Pal, D; Palounek, A P T; Pantuev, V; Papavassiliou, V; Park, B H; Park, I H; Park, J; Park, J S; Park, S; Park, S K; Park, W J; Pate, S F; Patel, L; Patel, M; Pei, H; Peng, J-C; Pereira, H; Perepelitsa, D V; Perera, G D N; Peresedov, V; Peressounko, D Yu; Perry, J; Petti, R; Pinkenburg, C; Pinson, R; Pisani, R P; Proissl, M; Purschke, M L; Purwar, A K; Qu, H; Rak, J; Rakotozafindrabe, A; Ramson, B J; Ravinovich, I; Read, K F; Rembeczki, S; Reuter, M; Reygers, K; Reynolds, D; Riabov, V; Riabov, Y; Richardson, E; Rinn, T; Roach, D; Roche, G; Rolnick, S D; Romana, A; Rosati, M; Rosen, C A; Rosendahl, S S E; Rosnet, P; Rowan, Z; Rubin, J G; Rukoyatkin, P; Ružička, P; Rykov, V L; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakai, S; Sakashita, K; Sakata, H; Sako, H; Samsonov, V; Sano, S; Sarsour, M; Sato, S; Sato, T; Savastio, M; Sawada, S; Schaefer, B; Schmoll, B K; Sedgwick, K; Seele, J; Seidl, R; Semenov, A Yu; Semenov, V; Sen, A; Seto, R; Sett, P; Sexton, A; Sharma, D; Shein, I; Shevel, A; Shibata, T-A; Shigaki, K; Shim, H H; Shimomura, M; Shoji, K; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Silvestre, C; Sim, K S; Singh, B K; Singh, C P; Singh, V; Skutnik, S; Slunečka, M; Snowball, M; Sodre, T; Soldatov, A; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Staley, F; Stankus, P W; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Sugitate, T; Suire, C; Sukhanov, A; Sumita, T; Sun, J; Sziklai, J; Tabaru, T; Takagi, S; Takagui, E M; Takahara, A; Taketani, A; Tanabe, R; Tanaka, Y; Taneja, S; Tanida, K; Tannenbaum, M J; Tarafdar, S; Taranenko, A; Tarján, P; Tennant, E; Themann, H; Thomas, D; Thomas, T L; Tieulent, R; Timilsina, A; Todoroki, T; Togawa, M; Toia, A; Tojo, J; Tomášek, L; Tomášek, M; Tomita, Y; Torii, H; Towell, C L; Towell, R; Towell, R S; Tram, V-N; Tserruya, I; Tsuchimoto, Y; Utsunomiya, K; Vale, C; Valle, H; van Hecke, H W; Vazquez-Zambrano, E; Veicht, A; Velkovska, J; Vértesi, R; Vinogradov, A A; Virius, M; Vossen, A; Vrba, V; Vznuzdaev, E; Wagner, M; Walker, D; Wang, X R; Watanabe, D; Watanabe, K; Watanabe, Y; Watanabe, Y S; Wei, F; Wei, R; Wessels, J; White, A S; White, S N; Winter, D; Woody, C L; Wright, R M; Wysocki, M; Xia, B; Xie, W; Xue, L; Yalcin, S; Yamaguchi, Y L; Yamaura, K; Yang, R; Yanovich, A; Yasin, Z; Ying, J; Yokkaichi, S; Yoo, J H; Yoo, J S; Yoon, I; You, Z; Young, G R; Younus, I; Yu, H; Yushmanov, I E; Zajc, W A; Zaudtke, O; Zelenski, A; Zhang, C; Zhou, S; Zimamyi, J; Zolin, L; Zou, L

    2015-10-01

    We present the first measurement of elliptic (v(2)) and triangular (v(3)) flow in high-multiplicity (3)He+Au collisions at √(s(NN))=200  GeV. Two-particle correlations, where the particles have a large separation in pseudorapidity, are compared in (3)He+Au and in p+p collisions and indicate that collective effects dominate the second and third Fourier components for the correlations observed in the (3)He+Au system. The collective behavior is quantified in terms of elliptic v(2) and triangular v(3) anisotropy coefficients measured with respect to their corresponding event planes. The v(2) values are comparable to those previously measured in d+Au collisions at the same nucleon-nucleon center-of-mass energy. Comparisons with various theoretical predictions are made, including to models where the hot spots created by the impact of the three (3)He nucleons on the Au nucleus expand hydrodynamically to generate the triangular flow. The agreement of these models with data may indicate the formation of low-viscosity quark-gluon plasma even in these small collision systems. PMID:26551807

  20. Measurements of Elliptic and Triangular Flow in High-Multiplicity 3He +Au Collisions at √{sN N }=200 GeV

    NASA Astrophysics Data System (ADS)

    Adare, A.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Akimoto, R.; Al-Bataineh, H.; Alexander, J.; Alfred, M.; Al-Ta'Ani, H.; Andrews, K. R.; Angerami, A.; Aoki, K.; Apadula, N.; Aphecetche, L.; Appelt, E.; Aramaki, Y.; Armendariz, R.; Aronson, S. H.; Asai, J.; Asano, H.; Aschenauer, E. C.; Atomssa, E. T.; Averbeck, R.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Bai, M.; Baksay, G.; Baksay, L.; Baldisseri, A.; Bandara, N. S.; Bannier, B.; Barish, K. N.; Barnes, P. D.; Bassalleck, B.; Basye, A. T.; Bathe, S.; Batsouli, S.; Baublis, V.; Baumann, C.; Bazilevsky, A.; Beaumier, M.; Beckman, S.; Belikov, S.; Belmont, R.; Ben-Benjamin, J.; Bennett, R.; Berdnikov, A.; Berdnikov, Y.; Bhom, J. H.; Bickley, A. A.; Blau, D. S.; Boissevain, J. G.; Bok, J. S.; Borel, H.; Boyle, K.; Brooks, M. L.; Broxmeyer, D.; Bryslawskyj, J.; Buesching, H.; Bumazhnov, V.; Bunce, G.; Butsyk, S.; Camacho, C. M.; Campbell, S.; Caringi, A.; Castera, P.; Chang, B. S.; Chang, W. C.; Charvet, J.-L.; Chen, C.-H.; Chernichenko, S.; Chi, C. Y.; Chiba, J.; Chiu, M.; Choi, I. J.; Choi, J. B.; Choudhury, R. K.; Christiansen, P.; Chujo, T.; Chung, P.; Churyn, A.; Chvala, O.; Cianciolo, V.; Citron, Z.; Cleven, C. R.; Cole, B. A.; Comets, M. P.; Conesa Del Valle, Z.; Connors, M.; Constantin, P.; Csanád, M.; Csörgő, T.; Dahms, T.; Dairaku, S.; Danchev, I.; Danley, D.; Das, K.; Datta, A.; Daugherity, M. S.; David, G.; Dayananda, M. K.; Deaton, M. B.; Deblasio, K.; Dehmelt, K.; Delagrange, H.; Denisov, A.; D'Enterria, D.; Deshpande, A.; Desmond, E. J.; Dharmawardane, K. V.; Dietzsch, O.; Dion, A.; Diss, P. B.; Do, J. H.; Donadelli, M.; D'Orazio, L.; Drapier, O.; Drees, A.; Drees, K. A.; Dubey, A. K.; Durham, J. M.; Durum, A.; Dutta, D.; Dzhordzhadze, V.; Edwards, S.; Efremenko, Y. V.; Egdemir, J.; Ellinghaus, F.; Emam, W. S.; Engelmore, T.; Enokizono, A.; En'yo, H.; Esumi, S.; Eyser, K. O.; Fadem, B.; Feege, N.; Fields, D. E.; Finger, M.; Finger, M.; Fleuret, F.; Fokin, S. L.; Fraenkel, Z.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fujiwara, K.; Fukao, Y.; Fusayasu, T.; Gadrat, S.; Gal, C.; Gallus, P.; Garg, P.; Garishvili, I.; Ge, H.; Giordano, F.; Glenn, A.; Gong, H.; Gong, X.; Gonin, M.; Gosset, J.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grim, G.; Grosse Perdekamp, M.; Gu, Y.; Gunji, T.; Guo, L.; Gustafsson, H.-Å.; Hachiya, T.; Hadj Henni, A.; Haegemann, C.; Haggerty, J. S.; Hahn, K. I.; Hamagaki, H.; Hamblen, J.; Hamilton, H. F.; Han, R.; Han, S. Y.; Hanks, J.; Harada, H.; Harper, C.; Hartouni, E. P.; Haruna, K.; Hasegawa, S.; Haseler, T. O. S.; Hashimoto, K.; Haslum, E.; Hayano, R.; He, X.; Heffner, M.; Hemmick, T. K.; Hester, T.; Hiejima, H.; Hill, J. C.; Hobbs, R.; Hohlmann, M.; Hollis, R. S.; Holzmann, W.; Homma, K.; Hong, B.; Horaguchi, T.; Hori, Y.; Hornback, D.; Hoshino, T.; Hotvedt, N.; Huang, J.; Huang, S.; Ichihara, T.; Ichimiya, R.; Iinuma, H.; Ikeda, Y.; Imai, K.; Imrek, J.; Inaba, M.; Inoue, Y.; Iordanova, A.; Isenhower, D.; Isenhower, L.; Ishihara, M.; Isobe, T.; Issah, M.; Isupov, A.; Ivanishchev, D.; Iwanaga, Y.; Jacak, B. V.; Jezghani, M.; Jia, J.; Jiang, X.; Jin, J.; Jinnouchi, O.; John, D.; Johnson, B. M.; Jones, T.; Joo, K. S.; Jouan, D.; Jumper, D. S.; Kajihara, F.; Kametani, S.; Kamihara, N.; Kamin, J.; Kanda, S.; Kaneta, M.; Kaneti, S.; Kang, B. H.; Kang, J. H.; Kang, J. S.; Kanou, H.; Kapustinsky, J.; Karatsu, K.; Kasai, M.; Kawall, D.; Kawashima, M.; Kazantsev, A. V.; Kempel, T.; Key, J. A.; Khachatryan, V.; Khanzadeev, A.; Kijima, K. M.; Kikuchi, J.; Kim, A.; Kim, B. I.; Kim, C.; Kim, D. H.; Kim, D. J.; Kim, E.; Kim, E.-J.; Kim, G. W.; Kim, M.; Kim, S. H.; Kim, Y.-J.; Kim, Y. K.; Kimelman, B.; Kinney, E.; Kiriluk, K.; Kiss, Á.; Kistenev, E.; Kitamura, R.; Kiyomichi, A.; Klatsky, J.; Klay, J.; Klein-Boesing, C.; Kleinjan, D.; Kline, P.; Koblesky, T.; Kochenda, L.; Kochetkov, V.; Komkov, B.; Konno, M.; Koster, J.; Kotchetkov, D.; Kotov, D.; Kozlov, A.; Král, A.; Kravitz, A.; Kubart, J.; Kunde, G. J.; Kurihara, N.; Kurita, K.; Kurosawa, M.; Kweon, M. J.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lai, Y. S.; Lajoie, J. G.; Layton, D.; Lebedev, A.; Lee, D. M.; Lee, J.; Lee, K. B.; Lee, K. S.; Lee, M. K.; Lee, S.; Lee, S. H.; Lee, S. R.; Lee, T.; Leitch, M. J.; Leite, M. A. L.; Lenzi, B.; Li, X.; Lichtenwalner, P.; Liebing, P.; Lim, S. H.; Linden Levy, L. A.; Liška, T.; Litvinenko, A.; Liu, H.; Liu, M. X.; Love, B.; Lynch, D.; Maguire, C. F.; Makdisi, Y. I.; Makek, M.; Malakhov, A.; Malik, M. D.; Manion, A.; Manko, V. I.; Mannel, E.; Mao, Y.; Mašek, L.; Masui, H.; Matathias, F.; McCumber, M.; McGaughey, P. L.; McGlinchey, D.; McKinney, C.; Means, N.; Meles, A.; Mendoza, M.; Meredith, B.; Miake, Y.; Mibe, T.; Mignerey, A. C.; Mikeš, P.; Miki, K.; Miller, T. E.; Milov, A.; Mioduszewski, S.; Mishra, D. K.; Mishra, M.; Mitchell, J. T.; Mitrovski, M.; Miyachi, Y.; Miyasaka, S.; Mizuno, S.; Mohanty, A. K.; Montuenga, P.; Moon, H. J.; Moon, T.; Morino, Y.; Morreale, A.; Morrison, D. P.; Motschwiller, S.; Moukhanova, T. V.; Mukhopadhyay, D.; Murakami, T.; Murata, J.; Mwai, A.; Nagamiya, S.; Nagashima, K.; Nagata, Y.; Nagle, J. L.; Naglis, M.; Nagy, M. I.; Nakagawa, I.; Nakagomi, H.; Nakamiya, Y.; Nakamura, K. R.; Nakamura, T.; Nakano, K.; Nam, S.; Nattrass, C.; Netrakanti, P. K.; Newby, J.; Nguyen, M.; Nihashi, M.; Niida, T.; Nishimura, S.; Norman, B. E.; Nouicer, R.; Novak, T.; Novitzky, N.; Nyanin, A. S.; Oakley, C.; O'Brien, E.; Oda, S. X.; Ogilvie, C. A.; Ohnishi, H.; Oka, M.; Okada, K.; Omiwade, O. O.; Onuki, Y.; Orjuela Koop, J. D.; Osborn, J. D.; Oskarsson, A.; Ouchida, M.; Ozawa, K.; Pak, R.; Pal, D.; Palounek, A. P. T.; Pantuev, V.; Papavassiliou, V.; Park, B. H.; Park, I. H.; Park, J.; Park, J. S.; Park, S.; Park, S. K.; Park, W. J.; Pate, S. F.; Patel, L.; Patel, M.; Pei, H.; Peng, J.-C.; Pereira, H.; Perepelitsa, D. V.; Perera, G. D. N.; Peresedov, V.; Peressounko, D. Yu.; Perry, J.; Petti, R.; Pinkenburg, C.; Pinson, R.; Pisani, R. P.; Proissl, M.; Purschke, M. L.; Purwar, A. K.; Qu, H.; Rak, J.; Rakotozafindrabe, A.; Ramson, B. J.; Ravinovich, I.; Read, K. F.; Rembeczki, S.; Reuter, M.; Reygers, K.; Reynolds, D.; Riabov, V.; Riabov, Y.; Richardson, E.; Rinn, T.; Roach, D.; Roche, G.; Rolnick, S. D.; Romana, A.; Rosati, M.; Rosen, C. A.; Rosendahl, S. S. E.; Rosnet, P.; Rowan, Z.; Rubin, J. G.; Rukoyatkin, P.; Ružička, P.; Rykov, V. L.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sakai, S.; Sakashita, K.; Sakata, H.; Sako, H.; Samsonov, V.; Sano, S.; Sarsour, M.; Sato, S.; Sato, T.; Savastio, M.; Sawada, S.; Schaefer, B.; Schmoll, B. K.; Sedgwick, K.; Seele, J.; Seidl, R.; Semenov, A. Yu.; Semenov, V.; Sen, A.; Seto, R.; Sett, P.; Sexton, A.; Sharma, D.; Shein, I.; Shevel, A.; Shibata, T.-A.; Shigaki, K.; Shim, H. H.; Shimomura, M.; Shoji, K.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Silvestre, C.; Sim, K. S.; Singh, B. K.; Singh, C. P.; Singh, V.; Skutnik, S.; Slunečka, M.; Snowball, M.; Sodre, T.; Soldatov, A.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Staley, F.; Stankus, P. W.; Stenlund, E.; Stepanov, M.; Ster, A.; Stoll, S. P.; Sugitate, T.; Suire, C.; Sukhanov, A.; Sumita, T.; Sun, J.; Sziklai, J.; Tabaru, T.; Takagi, S.; Takagui, E. M.; Takahara, A.; Taketani, A.; Tanabe, R.; Tanaka, Y.; Taneja, S.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tarján, P.; Tennant, E.; Themann, H.; Thomas, D.; Thomas, T. L.; Tieulent, R.; Timilsina, A.; Todoroki, T.; Togawa, M.; Toia, A.; Tojo, J.; Tomášek, L.; Tomášek, M.; Tomita, Y.; Torii, H.; Towell, C. L.; Towell, R.; Towell, R. S.; Tram, V.-N.; Tserruya, I.; Tsuchimoto, Y.; Utsunomiya, K.; Vale, C.; Valle, H.; van Hecke, H. W.; Vazquez-Zambrano, E.; Veicht, A.; Velkovska, J.; Vértesi, R.; Vinogradov, A. A.; Virius, M.; Vossen, A.; Vrba, V.; Vznuzdaev, E.; Wagner, M.; Walker, D.; Wang, X. R.; Watanabe, D.; Watanabe, K.; Watanabe, Y.; Watanabe, Y. S.; Wei, F.; Wei, R.; Wessels, J.; White, A. S.; White, S. N.; Winter, D.; Woody, C. L.; Wright, R. M.; Wysocki, M.; Xia, B.; Xie, W.; Xue, L.; Yalcin, S.; Yamaguchi, Y. L.; Yamaura, K.; Yang, R.; Yanovich, A.; Yasin, Z.; Ying, J.; Yokkaichi, S.; Yoo, J. H.; Yoo, J. S.; Yoon, I.; You, Z.; Young, G. R.; Younus, I.; Yu, H.; Yushmanov, I. E.; Zajc, W. A.; Zaudtke, O.; Zelenski, A.; Zhang, C.; Zhou, S.; Zimamyi, J.; Zolin, L.; Zou, L.; Phenix Collaboration

    2015-10-01

    We present the first measurement of elliptic (v2) and triangular (v3) flow in high-multiplicity 3He +Au collisions at √{sN N }=200 GeV . Two-particle correlations, where the particles have a large separation in pseudorapidity, are compared in 3He +Au and in p +p collisions and indicate that collective effects dominate the second and third Fourier components for the correlations observed in the 3He +Au system. The collective behavior is quantified in terms of elliptic v2 and triangular v3 anisotropy coefficients measured with respect to their corresponding event planes. The v2 values are comparable to those previously measured in d +Au collisions at the same nucleon-nucleon center-of-mass energy. Comparisons with various theoretical predictions are made, including to models where the hot spots created by the impact of the three 3He nucleons on the Au nucleus expand hydrodynamically to generate the triangular flow. The agreement of these models with data may indicate the formation of low-viscosity quark-gluon plasma even in these small collision systems.

  1. Elliptic flow in Pb+Pb collisions at {radical}(s{sub NN}) = 2.76 TeV: Hybrid model assessment of the first data

    SciTech Connect

    Hirano, Tetsufumi; Huovinen, Pasi; Nara, Yasushi

    2011-07-15

    We analyze the elliptic flow parameter v{sub 2} in Pb+Pb collisions at {radical}(s{sub NN}) = 2.76 TeV and in Au+Au collisions at {radical}(s{sub NN})=200 GeV using a hybrid model in which the evolution of the quark gluon plasma is described by ideal hydrodynamics with a state-of-the-art lattice QCD equation of state, and the subsequent hadronic stage by a hadron cascade model. For initial conditions, we employ Monte Carlo versions of the Glauber and the Kharzeev-Levin-Nardi models and compare results with each other. We demonstrate that the differential elliptic flow v{sub 2}(p{sub T}) hardly changes when the collision energy increases, whereas the integrated v{sub 2} increases due to the enhancement of mean transverse momentum. The amount of increase of both v{sub 2} and mean p{sub T} depends significantly on the model of initialization.

  2. J/ψ elliptic flow in Pb-Pb collisions at √(s(NN))=2.76 TeV.

    PubMed

    Abbas, E; Abelev, B; Adam, J; Adamová, D; Adare, A M; Aggarwal, M M; Aglieri Rinella, G; Agnello, M; Agocs, A G; Agostinelli, A; Ahammed, Z; Ahmad, N; Ahmad Masoodi, A; Ahn, S A; Ahn, S U; Aimo, I; Ajaz, M; Akindinov, A; Aleksandrov, D; Alessandro, B; Alici, A; Alkin, A; Almaráz Aviña, E; Alme, J; Alt, T; Altini, V; Altinpinar, S; Altsybeev, I; Andrei, C; Andronic, A; Anguelov, V; Anielski, J; Anson, C; Antičić, T; Antinori, F; Antonioli, P; Aphecetche, L; Appelshäuser, H; Arbor, N; Arcelli, S; Arend, A; Armesto, N; Arnaldi, R; Aronsson, T; Arsene, I C; Arslandok, M; Asryan, A; Augustinus, A; Averbeck, R; Awes, T C; Äystö, J; Azmi, M D; Bach, M; Badalà, A; Baek, Y W; Bailhache, R; Bala, R; Baldisseri, A; Baltasar Dos Santos Pedrosa, F; Bán, J; Baral, R C; Barbera, R; Barile, F; Barnaföldi, G G; Barnby, L S; Barret, V; Bartke, J; Basile, M; Bastid, N; Basu, S; Bathen, B; Batigne, G; Batyunya, B; Batzing, P C; Baumann, C; Bearden, I G; Beck, H; Behera, N K; Belikov, I; Bellini, F; Bellwied, R; Belmont-Moreno, E; Bencedi, G; Beole, S; Berceanu, I; Bercuci, A; Berdnikov, Y; Berenyi, D; Bergognon, A A E; Bertens, R A; Berzano, D; Betev, L; Bhasin, A; Bhati, A K; Bhom, J; Bianchi, N; Bianchi, L; Bianchin, C; Bielčík, J; Bielčíková, J; Bilandzic, A; Bjelogrlic, S; Blanco, F; Blanco, F; Blau, D; Blume, C; Boccioli, M; Böttger, S; Bogdanov, A; Bøggild, H; Bogolyubsky, M; Boldizsár, L; Bombara, M; Book, J; Borel, H; Borissov, A; Bossú, F; Botje, M; Botta, E; Braidot, E; Braun-Munzinger, P; Bregant, M; Breitner, T; Broker, T A; Browning, T A; Broz, M; Brun, R; Bruna, E; Bruno, G E; Budnikov, D; Buesching, H; Bufalino, S; Buncic, P; Busch, O; Buthelezi, Z; Caffarri, D; Cai, X; Caines, H; Calvo Villar, E; Camerini, P; Canoa Roman, V; Cara Romeo, G; Carena, W; Carena, F; Carlin Filho, N; Carminati, F; Casanova Díaz, A; Castillo Castellanos, J; Castillo Hernandez, J F; Casula, E A R; Catanescu, V; Cavicchioli, C; Ceballos Sanchez, C; Cepila, J; Cerello, P; Chang, B; Chapeland, S; Charvet, J L; Chattopadhyay, S; Chattopadhyay, S; Cherney, M; Cheshkov, C; Cheynis, B; Chibante Barroso, V; Chinellato, D D; Chochula, P; Chojnacki, M; Choudhury, S; Christakoglou, P; Christensen, C H; Christiansen, P; Chujo, T; Chung, S U; Cicalo, C; Cifarelli, L; Cindolo, F; Cleymans, J; Colamaria, F; Colella, D; Collu, A; Conesa Balbastre, G; Conesa del Valle, Z; Connors, M E; Contin, G; Contreras, J G; Cormier, T M; Corrales Morales, Y; Cortese, P; Cortés Maldonado, I; Cosentino, M R; Costa, F; Cotallo, M E; Crescio, E; Crochet, P; Cruz Alaniz, E; Cruz Albino, R; Cuautle, E; Cunqueiro, L; Dainese, A; Dang, R; Danu, A; Das, D; Das, K; Das, S; Das, I; Dash, A; Dash, S; De, S; de Barros, G O V; De Caro, A; de Cataldo, G; de Cuveland, J; De Falco, A; De Gruttola, D; Delagrange, H; Deloff, A; De Marco, N; Dénes, E; De Pasquale, S; Deppman, A; D'Erasmo, G; de Rooij, R; Diaz Corchero, M A; Di Bari, D; Dietel, T; Di Giglio, C; Di Liberto, S; Di Mauro, A; Di Nezza, P; Divià, R; Djuvsland, Ø; Dobrin, A; Dobrowolski, T; Dönigus, B; Dordic, O; Driga, O; Dubey, A K; Dubla, A; Ducroux, L; Dupieux, P; Dutta Majumdar, A K; Elia, D; Emschermann, D; Engel, H; Erazmus, B; Erdal, H A; Eschweiler, D; Espagnon, B; Estienne, M; Esumi, S; Evans, D; Evdokimov, S; Eyyubova, G; Fabris, D; Faivre, J; Falchieri, D; Fantoni, A; Fasel, M; Fehlker, D; Feldkamp, L; Felea, D; Feliciello, A; Fenton-Olsen, B; Feofilov, G; Fernández Téllez, A; Ferretti, A; Festanti, A; Figiel, J; Figueredo, M A S; Filchagin, S; Finogeev, D; Fionda, F M; Fiore, E M; Floratos, E; Floris, M; Foertsch, S; Foka, P; Fokin, S; Fragiacomo, E; Francescon, A; Frankenfeld, U; Fuchs, U; Furget, C; Fusco Girard, M; Gaardhøje, J J; Gagliardi, M; Gago, A; Gallio, M; Gangadharan, D R; Ganoti, P; Garabatos, C; Garcia-Solis, E; Gargiulo, C; Garishvili, I; Gerhard, J; Germain, M; Geuna, C; Gheata, A; Gheata, M; Ghidini, B; Ghosh, P; Gianotti, P; Girard, M R; Giubellino, P; Gladysz-Dziadus, E; Glässel, P; Gomez, R; Ferreiro, E G; González-Trueba, L H; González-Zamora, P; Gorbunov, S; Goswami, A; Gotovac, S; Graczykowski, L K; Grajcarek, R; Grelli, A; Grigoras, A; Grigoras, C; Grigoriev, V; Grigoryan, A; Grigoryan, S; Grinyov, B; Grion, N; Gros, P; Grosse-Oetringhaus, J F; Grossiord, J-Y; Grosso, R; Guber, F; Guernane, R; Guerzoni, B; Guilbaud, M; Gulbrandsen, K; Gulkanyan, H; Gunji, T; Gupta, A; Gupta, R; Haake, R; Haaland, Ø; Hadjidakis, C; Haiduc, M; Hamagaki, H; Hamar, G; Han, B H; Hanratty, L D; Hansen, A; Harmanová-Tóthová, Z; Harris, J W; Hartig, M; Harton, A; Hatzifotiadou, D; Hayashi, S; Hayrapetyan, A; Heckel, S T; Heide, M; Helstrup, H; Herghelegiu, A; Herrera Corral, G; Herrmann, N; Hess, B A; Hetland, K F; Hicks, B; Hippolyte, B; Hori, Y; Hristov, P; Hřivnáčová, I; Huang, M; Humanic, T J; Hwang, D S; Ichou, R; Ilkaev, R; Ilkiv, I; Inaba, M; Incani, E; Innocenti, P G; Innocenti, G M; Ippolitov, M; Irfan, M; Ivan, C; Ivanov, M; Ivanov, V; Ivanov, A; Ivanytskyi, O; Jachołkowski, A; Jacobs, P M; Jahnke, C; Jang, H J; Janik, M A; Jayarathna, P H S Y; Jena, S; Jha, D M; Jimenez Bustamante, R T; Jones, P G; Jung, H; Jusko, A; Kaidalov, A B; Kalcher, S; Kaliňák, P; Kalliokoski, T; Kalweit, A; Kang, J H; Kaplin, V; Kar, S; Karasu Uysal, A; Karavichev, O; Karavicheva, T; Karpechev, E; Kazantsev, A; Kebschull, U; Keidel, R; Ketzer, B; Khan, S A; Khan, M M; Khan, P; Khan, K H; Khanzadeev, A; Kharlov, Y; Kileng, B; Kim, M; Kim, S; Kim, M; Kim, J S; Kim, J H; Kim, T; Kim, B; Kim, D J; Kim, D W; Kirsch, S; Kisel, I; Kiselev, S; Kisiel, A; Klay, J L; Klein, J; Klein-Bösing, C; Kliemant, M; Kluge, A; Knichel, M L; Knospe, A G; Köhler, M K; Kollegger, T; Kolojvari, A; Kompaniets, M; Kondratiev, V; Kondratyeva, N; Konevskikh, A; Kovalenko, V; Kowalski, M; Kox, S; Koyithatta Meethaleveedu, G; Kral, J; Králik, I; Kramer, F; Kravčáková, A; Krelina, M; Kretz, M; Krivda, M; Krizek, F; Krus, M; Kryshen, E; Krzewicki, M; Kucera, V; Kucheriaev, Y; Kugathasan, T; Kuhn, C; Kuijer, P G; Kulakov, I; Kumar, J; Kurashvili, P; Kurepin, A; Kurepin, A B; Kuryakin, A; Kushpil, S; Kushpil, V; Kvaerno, H; Kweon, M J; Kwon, Y; Ladrón de Guevara, P; Lakomov, I; Langoy, R; La Pointe, S L; Lara, C; Lardeux, A; La Rocca, P; Lea, R; Lechman, M; Lee, S C; Lee, G R; Legrand, I; Lehnert, J; Lemmon, R C; Lenhardt, M; Lenti, V; León, H; Leoncino, M; León Monzón, I; Lévai, P; Li, S; Lien, J; Lietava, R; Lindal, S; Lindenstruth, V; Lippmann, C; Lisa, M A; Ljunggren, H M; Lodato, D F; Loenne, P I; Loggins, V R; Loginov, V; Lohner, D; Loizides, C; Loo, K K; Lopez, X; López Torres, E; Løvhøiden, G; Lu, X-G; Luettig, P; Lunardon, M; Luo, J; Luparello, G; Luzzi, C; Ma, R; Ma, K; Madagodahettige-Don, D M; Maevskaya, A; Mager, M; Mahapatra, D P; Maire, A; Malaev, M; Maldonado Cervantes, I; Malinina, L; Mal'Kevich, D; Malzacher, P; Mamonov, A; Manceau, L; Mangotra, L; Manko, V; Manso, F; Manukyan, N; Manzari, V; Mao, Y; Marchisone, M; Mareš, J; Margagliotti, G V; Margotti, A; Marín, A; Markert, C; Marquard, M; Martashvili, I; Martin, N A; Martinengo, P; Martínez, M I; Martínez Davalos, A; Martínez García, G; Martynov, Y; Mas, A; Masciocchi, S; Masera, M; Masoni, A; Massacrier, L; Mastroserio, A; Matyja, A; Mayer, C; Mazer, J; Mazzoni, M A; Meddi, F; Menchaca-Rocha, A; Mercado Pérez, J; Meres, M; Miake, Y; Mikhaylov, K; Milano, L; Milosevic, J; Mischke, A; Mishra, A N; Miśkowiec, D; Mitu, C; Mizuno, S; Mlynarz, J; Mohanty, B; Molnar, L; Montaño Zetina, L; Monteno, M; Montes, E; Moon, T; Morando, M; Moreira De Godoy, D A; Moretto, S; Morreale, A; Morsch, A; Muccifora, V; Mudnic, E; Muhuri, S; Mukherjee, M; Müller, H; Munhoz, M G; Murray, S; Musa, L; Musinsky, J; Nandi, B K; Nania, R; Nappi, E; Nattrass, C; Nayak, T K; Nazarenko, S; Nedosekin, A; Nicassio, M; Niculescu, M; Nielsen, B S; Niida, T; Nikolaev, S; Nikolic, V; Nikulin, S; Nikulin, V; Nilsen, B S; Nilsson, M S; Noferini, F; Nomokonov, P; Nooren, G; Nyanin, A; Nyatha, A; Nygaard, C; Nystrand, J; Ochirov, A; Oeschler, H; Oh, S; Oh, S K; Oleniacz, J; Oliveira Da Silva, A C; Oppedisano, C; Ortiz Velasquez, A; Oskarsson, A; Ostrowski, P; Otwinowski, J; Oyama, K; Ozawa, K; Pachmayer, Y; Pachr, M; Padilla, F; Pagano, P; Paić, G; Painke, F; Pajares, C; Pal, S K; Palaha, A; Palmeri, A; Papikyan, V; Pappalardo, G S; Park, W J; Passfeld, A; Patalakha, D I; Paticchio, V; Paul, B; Pavlinov, A; Pawlak, T; Peitzmann, T; Pereira Da Costa, H; Pereira De Oliveira Filho, E; Peresunko, D; Pérez Lara, C E; Perrino, D; Peryt, W; Pesci, A; Pestov, Y; Petráček, V; Petran, M; Petris, M; Petrov, P; Petrovici, M; Petta, C; Piano, S; Pikna, M; Pillot, P; Pinazza, O; Pinsky, L; Pitz, N; Piyarathna, D B; Planinic, M; Płoskoń, M; Pluta, J; Pocheptsov, T; Pochybova, S; Podesta-Lerma, P L M; Poghosyan, M G; Polák, K; Polichtchouk, B; Poljak, N; Pop, A; Porteboeuf-Houssais, S; Pospíšil, V; Potukuchi, B; Prasad, S K; Preghenella, R; Prino, F; Pruneau, C A; Pshenichnov, I; Puddu, G; Punin, V; Putiš, M; Putschke, J; Qvigstad, H; Rachevski, A; Rademakers, A; Räihä, T S; Rak, J; Rakotozafindrabe, A; Ramello, L; Raniwala, S; Raniwala, R; Räsänen, S S; Rascanu, B T; Rathee, D; Rauch, W; Read, K F; Real, J S; Redlich, K; Reed, R J; Rehman, A; Reichelt, P; Reicher, M; Renfordt, R; Reolon, A R; Reshetin, A; Rettig, F; Revol, J-P; Reygers, K; Riccati, L; Ricci, R A; Richert, T; Richter, M; Riedler, P; Riegler, W; Riggi, F; Rodríguez Cahuantzi, M; Rodriguez Manso, A; Røed, K; Rogochaya, E; Rohr, D; Röhrich, D; Romita, R; Ronchetti, F; Rosnet, P; Rossegger, S; Rossi, A; Roy, P; Roy, C; Rubio Montero, A J; Rui, R; Russo, R; Ryabinkin, E; Rybicki, A; Sadovsky, S; Šafařík, K; Sahoo, R; Sahu, P K; Saini, J; Sakaguchi, H; Sakai, S; Sakata, D; Salgado, C A; Salzwedel, J; Sambyal, S; Samsonov, V; Sanchez Castro, X; Šándor, L; Sandoval, A; Sano, M; Santagati, G; Santoro, R; Sarkamo, J; Sarkar, D; Scapparone, E; Scarlassara, F; Scharenberg, R P; Schiaua, C; Schicker, R; Schmidt, H R; Schmidt, C; Schuchmann, S; Schukraft, J; Schuster, T; Schutz, Y; Schwarz, K; Schweda, K; Scioli, G; Scomparin, E; Scott, R; Scott, P A; Segato, G; Selyuzhenkov, I; Senyukov, S; Seo, J; Serci, S; Serradilla, E; Sevcenco, A; Shabetai, A; Shabratova, G; Shahoyan, R; Sharma, N; Sharma, S; Rohni, S; Shigaki, K; Shtejer, K; Sibiriak, Y; Sicking, E; Siddhanta, S; Siemiarczuk, T; Silvermyr, D; Silvestre, C; Simatovic, G; Simonetti, G; Singaraju, R; Singh, R; Singha, S; Singhal, V; Sinha, B C; Sinha, T; Sitar, B; Sitta, M; Skaali, T B; Skjerdal, K; Smakal, R; Smirnov, N; Snellings, R J M; Søgaard, C; Soltz, R; Song, M; Song, J; Soos, C; Soramel, F; Sputowska, I; Spyropoulou-Stassinaki, M; Srivastava, B K; Stachel, J; Stan, I; Stefanek, G; Steinpreis, M; Stenlund, E; Steyn, G; Stiller, J H; Stocco, D; Stolpovskiy, M; Strmen, P; Suaide, A A P; Subieta Vásquez, M A; Sugitate, T; Suire, C; Sultanov, R; Šumbera, M; Susa, T; Symons, T J M; Szanto de Toledo, A; Szarka, I; Szczepankiewicz, A; Szymański, M; Takahashi, J; Tangaro, M A; Tapia Takaki, J D; Tarantola Peloni, A; Tarazona Martinez, A; Tauro, A; Tejeda Muñoz, G; Telesca, A; Ter Minasyan, A; Terrevoli, C; Thäder, J; Thomas, D; Tieulent, R; Timmins, A R; Tlusty, D; Toia, A; Torii, H; Toscano, L; Trubnikov, V; Truesdale, D; Trzaska, W H; Tsuji, T; Tumkin, A; Turrisi, R; Tveter, T S; Ulery, J; Ullaland, K; Ulrich, J; Uras, A; Urciuoli, G M; Usai, G L; Vajzer, M; Vala, M; Valencia Palomo, L; Vande Vyvre, P; Van Hoorne, J W; van Leeuwen, M; Vannucci, L; Vargas, A; Varma, R; Vasileiou, M; Vasiliev, A; Vechernin, V; Veldhoen, M; Venaruzzo, M; Vercellin, E; Vergara, S; Vernet, R; Verweij, M; Vickovic, L; Viesti, G; Viinikainen, J; Vilakazi, Z; Villalobos Baillie, O; Vinogradov, Y; Vinogradov, L; Vinogradov, A; Virgili, T; Viyogi, Y P; Vodopyanov, A; Völkl, M A; Voloshin, S; Voloshin, K; Volpe, G; von Haller, B; Vorobyev, I; Vranic, D; Vrláková, J; Vulpescu, B; Vyushin, A; Wagner, B; Wagner, V; Wan, R; Wang, Y; Wang, M; Wang, Y; Watanabe, K; Weber, M; Wessels, J P; Westerhoff, U; Wiechula, J; Wikne, J; Wilde, M; Wilk, G; Williams, M C S; Windelband, B; Xaplanteris Karampatsos, L; Yaldo, C G; Yamaguchi, Y; Yang, S; Yang, P; Yang, H; Yasnopolskiy, S; Yi, J; Yin, Z; Yoo, I-K; Yoon, J; Yu, W; Yuan, X; Yushmanov, I; Zaccolo, V; Zach, C; Zampolli, C; Zaporozhets, S; Zarochentsev, A; Závada, P; Zaviyalov, N; Zbroszczyk, H; Zelnicek, P; Zgura, I S; Zhalov, M; Zhang, H; Zhang, X; Zhang, Y; Zhou, D; Zhou, F; Zhou, Y; Zhu, H; Zhu, J; Zhu, X; Zhu, J; Zichichi, A; Zimmermann, A; Zinovjev, G; Zoccarato, Y; Zynovyev, M; Zyzak, M

    2013-10-18

    We report on the first measurement of inclusive J/ψ elliptic flow v2 in heavy-ion collisions at the LHC. The measurement is performed with the ALICE detector in Pb-Pb collisions at √(s(NN))=2.76 TeV in the rapidity range 2.5elliptic flow measurement complements the previously reported ALICE results on the inclusive J/ψ nuclear modification factor and favors the scenario of a significant fraction of J/ψ production from charm quarks in a deconfined partonic phase. PMID:24182258

  3. Measurements of elliptic and triangular flow in high-multiplicity 3He+Au collisions at √sNN=200 GeV

    SciTech Connect

    Adare, A.

    2015-09-28

    We present the first measurement of elliptic (v2) and triangular (v3) flow in high-multiplicity 3He+Aucollisions at √sNN=200 GeV. Two-particle correlations, where the particles have a large separation in pseudorapidity, are compared in 3He+Au and in p+p collisions and indicate that collective effects dominate the second and third Fourier components for the correlations observed in the 3He+Ausystem. The collective behavior is quantified in terms of elliptic v2 and triangular v3 anisotropy coefficients measured with respect to their corresponding event planes. The v2 values are comparable to those previously measured in d+Au collisions at the same nucleon-nucleon center-of-mass energy. Comparisons with various theoretical predictions are made, including to models where the hot spots created by the impact of the three 3He nucleons on the Au nucleus expand hydrodynamically to generate the triangular flow. The agreement of these models with data may indicate the formation of low-viscosity quark-gluon plasma even in these small collision systems.

  4. Charge-asymmetry dependence of kaon elliptic flow in Au +Au collisions at √{sNN} = 27 GeV from STAR

    NASA Astrophysics Data System (ADS)

    Cabrera, Keenan; STAR Collaboration

    2015-10-01

    Theory predicts that a chiral magnetic wave (CMW) at finite baryon density can induce a charge-asymmetry dependence of elliptic flow (v2) of particles produced in heavy-ion collisions. In the case of pions, STAR has observed that v2 (π-) -v2 (π+) exhibits a linear dependence on charge asymmetry with a positive slope in Au +Au collisions from 27 to 200 GeV. This is consistent with the CMW picture. At lower collision energies, it was found that the charge-asymmetry integrated v2 for negative pions is higher while for kaons, the positive charge is favored. Therefore, an observation of the same positive linear dependence of kaon v2 difference on charge asymmetry will provide a further test on the CMW predictions in heavy-ion collisions. In this work, we will present the status of our kaon elliptic flow measurements as a function of charge asymmetry for Au +Au collisions at √{sNN} = 27 GeV. For the STAR Collaboration.

  5. Electro-magnetic physics studies at RHIC: Neutral pion production, direct photon HBT, photon elliptic flow in gold-gold collisions at sqrt(s_NN) = 200 GeV and the Muon Telescope Detector simulation

    NASA Astrophysics Data System (ADS)

    Lin, Guoji

    Electro-magnetic (E&M) probes such as direct photons and muons (mu) are important tools to study the properties of the extremely hot and dense matter created in heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC). In this thesis, several topics of E&M physics will be addressed, including neutral pion (pi0) production, direct photon HBT, and photon elliptic flow (v2) in Au+Au collisions at sNN = 200 GeV. A discussion on the simulation study of the new Muon Telescope Detector (MTD) will also be presented. The pi0 production is a fundamental measurement of hadron production and prerequisite for the background study of direct photons. Neutral pions are reconstructed using the photons detected by the STAR Barrel Electro-magnetic Calorimeter (BEMC) and the Time Projection Chamber (TPC). Spectra of pi 0 are measured at transverse momentum 1 < pT < 12 GeV/c near mid-rapidity (0 < eta < 0.8) in 200 GeV Au+Au collisions. The spectra and nuclear modification factors RCP and RAA are compared to earlier pi+/- and pi0 results. Direct photon Hanbury-Brown and Twiss (HBT) correlations can reveal information of the system size throughout the whole collision. A first attempt of direct photon HBT study at RHIC in 200 GeV Au+Au collisions is done using photons detected by the STAR BEMC and TPC. All unknown correlation at small Qinv is observed, whose magnitude is much larger than the expected HBT signal, and possible causes of the correlation will be discussed. Direct photon elliptic flow (v2) at intermediate to high pT is sensitive to the source of direct photon production. Results of inclusive photon v2 in 200 GeV Au+Au collisions are presented. The v2 of pi0 decay photons is calculated from the previously published pi results. The comparison between inclusive and decay photon v 2 indicates that direct photon v2 is small. A new large-area Muon Telescope Detector at mid-rapidity at RHIC is proposed and under investigation, using the Long-strip Multi-Gap Resistive Plate

  6. Centrality dependence of elliptic flow of multi-strange hadrons in Au+Au collisions at √sNN = 200 GeV

    NASA Astrophysics Data System (ADS)

    Shi, Shusu

    2016-01-01

    We present recent results of the mid-rapidity elliptic flow (ν2) for multi-strange hadrons and the ϕ meson as a function of centrality in Au + Au collisions at the center of mass energy √sNN = 200 GeV. The transverse momentum dependence of ϕ and Ω ν2 is similar to that of pion and proton, indicating that the heavier strange (s) quark flows as strongly as the lighter up (u) and down (d) quarks. These observations constitute a clear piece of evidence for the development of partonic collectivity in heavy-ion collisions at the top RHIC energy. In addition, the mass ordering of ν2 breaks between the ϕ and proton at low transverse momenta in the 0-30% centrality bin, possibly due to the effect of late hadronic interactions on the proton ν2.

  7. Cavitation erosion prediction based on analysis of flow dynamics and impact load spectra

    SciTech Connect

    Mihatsch, Michael S. Schmidt, Steffen J.; Adams, Nikolaus A.

    2015-10-15

    Cavitation erosion is the consequence of repeated collapse-induced high pressure-loads on a material surface. The present paper assesses the prediction of impact load spectra of cavitating flows, i.e., the rate and intensity distribution of collapse events based on a detailed analysis of flow dynamics. Data are obtained from a numerical simulation which employs a density-based finite volume method, taking into account the compressibility of both phases, and resolves collapse-induced pressure waves. To determine the spectrum of collapse events in the fluid domain, we detect and quantify the collapse of isolated vapor structures. As reference configuration we consider the expansion of a liquid into a radially divergent gap which exhibits unsteady sheet and cloud cavitation. Analysis of simulation data shows that global cavitation dynamics and dominant flow events are well resolved, even though the spatial resolution is too coarse to resolve individual vapor bubbles. The inviscid flow model recovers increasingly fine-scale vapor structures and collapses with increasing resolution. We demonstrate that frequency and intensity of these collapse events scale with grid resolution. Scaling laws based on two reference lengths are introduced for this purpose. We show that upon applying these laws impact load spectra recorded on experimental and numerical pressure sensors agree with each other. Furthermore, correlation between experimental pitting rates and collapse-event rates is found. Locations of high maximum wall pressures and high densities of collapse events near walls obtained numerically agree well with areas of erosion damage in the experiment. The investigation shows that impact load spectra of cavitating flows can be inferred from flow data that captures the main vapor structures and wave dynamics without the need for resolving all flow scales.

  8. Elliptic and triangular flow in p-Pb and peripheral Pb-Pb collisions from parton scatterings

    SciTech Connect

    Bzdak, Adam; Ma, Guo-Liang

    2014-12-15

    Using a multiphase transport model (AMPT) we calculate the elliptic v₂ and triangular v₃ Fourier coefficients of the two-particle azimuthal correlation function in proton-nucleus (p-Pb) and peripheral nucleus-nucleus (Pb-Pb) collisions. Our results for v₃ are in a good agreement with the CMS data collected at the Large Hadron Collider. The v₂ coefficient is very well described in p-Pb collisions and is underestimated for higher transverse momenta in Pb-Pb interactions. The characteristic mass ordering of v₂ in p-Pb is reproduced, whereas for v₃, this effect is not observed. We further predict the pseudorapidity dependence of v₂ and v₃ in p-Pb and observe that both are increasing when going from a proton side to a Pb-nucleus side. Predictions for the higher-order Fourier coefficients, v₄ and v₅, in p-Pb are also presented.

  9. Elliptic and triangular flow in p-Pb and peripheral Pb-Pb collisions from parton scatterings

    DOE PAGESBeta

    Bzdak, Adam; Ma, Guo-Liang

    2014-12-15

    Using a multiphase transport model (AMPT) we calculate the elliptic v₂ and triangular v₃ Fourier coefficients of the two-particle azimuthal correlation function in proton-nucleus (p-Pb) and peripheral nucleus-nucleus (Pb-Pb) collisions. Our results for v₃ are in a good agreement with the CMS data collected at the Large Hadron Collider. The v₂ coefficient is very well described in p-Pb collisions and is underestimated for higher transverse momenta in Pb-Pb interactions. The characteristic mass ordering of v₂ in p-Pb is reproduced, whereas for v₃, this effect is not observed. We further predict the pseudorapidity dependence of v₂ and v₃ in p-Pb andmore » observe that both are increasing when going from a proton side to a Pb-nucleus side. Predictions for the higher-order Fourier coefficients, v₄ and v₅, in p-Pb are also presented.« less

  10. Multi-strange baryon elliptic flow in Pb-Pb collisions at sqrt {s_{NN} } = 2.76 TeV measured with the ALICE detector

    NASA Astrophysics Data System (ADS)

    Yin, Zhongbao

    2012-12-01

    We present the results on elliptic flow with multi-strange baryons produced in Pb-Pb collisions at sqrt {s_{NN} } = 2.76 TeV. The analysis is performed with the ALICE detector at LHC. Multi-strange baryons are reconstructed via their decay topologies and the v 2 measurements are analyzed with the two-particle scalar product method. The p T differential v 2 values are compared to the viscous hydrodynamical (VISH2+1) model calculation and to the STAR measurements in Au-Au collisions at sqrt {s_{NN} } = 200 GeV. We found that the model describes ≡ and Ωv 2 measurements within uncertainties. The differential v 2 of ≡ and Ω is similar to the STAR measurements at 200 GeV in Au-Au collisions.

  11. Multi-strange baryon elliptic flow in Pb-Pb collisions at sqrt {s_{NN} } = 2.76 TeV measured with the ALICE detector

    NASA Astrophysics Data System (ADS)

    Yin, Zhongbao

    2012-12-01

    We present the results on elliptic flow with multi-strange baryons produced in Pb-Pb collisions at sqrt {s_{NN} } = 2.76 TeV. The analysis is performed with the ALICE detector at LHC. Multi-strange baryons are reconstructed via their decay topologies and the v 2 measurements are analyzed with the two-particle scalar product method. The p T differential v 2 values are compared to the viscous hydrodynamical (VISH2+1) model calculation and to the STAR measurements in Au-Au collisions at sqrt {s_{NN} } = 200 GeV. We found that the model describes ≡ and Ω v 2 measurements within uncertainties. The differential v 2 of ≡ and Ω is similar to the STAR measurements at 200 GeV in Au-Au collisions.

  12. Centrality dependence of identified particle elliptic flow in relativistic heavy ion collisions at √{sN N}=7.7 -62.4 GeV

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Bai, X.; Bairathi, V.; Banerjee, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, D.; Brandin, A. V.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cervantes, M. C.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, X.; Chen, J. H.; Cheng, J.; Cherney, M.; Chisman, O.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Hamad, A.; Hamed, A.; Haque, R.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, H. Z.; Huang, B.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Jiang, K.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikoła, D. P.; Kisel, I.; Kisiel, A.; Kochenda, L.; Koetke, D. D.; Kollegger, T.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, X.; Li, Y.; Li, W.; Li, C.; Li, X.; Li, Z. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, L.; Ma, Y. G.; Ma, G. L.; Ma, R.; Magdy, N.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; Meehan, K.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V.; Olvitt, D.; Page, B. S.; Pak, R.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Peterson, A.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, S.; Raniwala, R.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Salur, S.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Sharma, M. K.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stepanov, M.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B.; Sun, X.; Sun, Z.; Sun, Y.; Sun, X. M.; Surrow, B.; Svirida, N.; Szelezniak, M. A.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A.; Thäder, J.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, F.; Wang, Y.; Wang, G.; Wang, Y.; Wang, J. S.; Wang, H.; Webb, J. C.; Webb, G.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Wu, Y.; Xiao, Z. G.; Xie, W.; Xin, K.; Xu, Z.; Xu, H.; Xu, Y. F.; Xu, Q. H.; Xu, N.; Yang, Y.; Yang, C.; Yang, S.; Yang, Y.; Yang, Q.; Ye, Z.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, Y.; Zhang, S.; Zhang, J.; Zhang, J.; Zhang, Z.; Zhang, X. P.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2016-01-01

    Elliptic flow (v2) values for identified particles at midrapidity in Au + Au collisions measured by the STAR experiment in the Beam Energy Scan at the Relativistic Heavy Ion Collider at √{sN N}= 7.7 -62.4 GeV are presented for three centrality classes. The centrality dependence and the data at √{sN N}= 14.5 GeV are new. Except at the lowest beam energies, we observe a similar relative v2 baryon-meson splitting for all centrality classes which is in agreement within 15% with the number-of-constituent quark scaling. The larger v2 for most particles relative to antiparticles, already observed for minimum bias collisions, shows a clear centrality dependence, with the largest difference for the most central collisions. Also, the results are compared with a multiphase transport (AMPT) model and fit with a blast wave model.

  13. PASSIVE CONTROL OF PARTICLE DISPERSION IN A PARTICLE-LADEN CIRCULAR JET USING ELLIPTIC CO-ANNULAR FLOW: A MEANS FOR IMPROVING UTILIZATION AND EMISSION REDUCTIONS IN PULVERIZED COAL BURNER

    SciTech Connect

    Ahsan R. Choudhuri

    2003-06-01

    A passive control technology utilizing elliptic co-flow to control the particle flinging and particle dispersion in a particle (coal)-laden flow was investigated using experimental and numerical techniques. Preferential concentration of particles occurs in particle-laden jets used in pulverized coal burner and causes uncontrollable NO{sub x} formation due to inhomogeneous local stoichiometry. This particular project was aimed at characterizing the near-field flow behavior of elliptic coaxial jets. The knowledge gained from the project will serve as the basis of further investigation on fluid-particle interactions in an asymmetric coaxial jet flow-field and thus is important to improve the design of pulverized coal burners where non-homogeneity of particle concentration causes increased NO{sub x} formation.

  14. Inertial Subrange Spectra in the Log-Law Layer of Turbulent Channel Flow

    NASA Astrophysics Data System (ADS)

    Kaneda, Yukio; Morishita, Koji; Ishihara, Takashi

    2013-11-01

    High resolution direct numerical simulations (DNSs) of turbulent channel flows with the friction Reynolds number Reτ up to 5120 show that there exists a layer at y+ being approximately between 200 and 1200, in which the mean velocity profile and the diagonal components of the inertial subrange velocity correlation spectra fit well to the logarithmic law and the k - 5 / 3 law, respectively. Here y+ is the distance from the wall normalized by the wall unit, and k is the wavenumber in the stream wise direction. The DNS data suggest that in the layer (log-law layer), there exists a high wave number range in which the influence of the mean flow on the turbulence statistics may be regarded to be small as compared to that of nonlinear interactions between the small-scale eddies of size ~ 1 / (wave number), so that the former influence may be treated as a perturbation added to the turbulent state determined by the nonlinear turbulence dynamics in the absence of the mean flow. A perturbation analysis on the basis of this idea yields a simple prediction for the anisotropic velocity correlation spectra in the inertial subrange. The DNS data agree fairly well with the prediction.

  15. Centrality and Transverse Momentum Dependence of Elliptic Flow of Multistrange Hadrons and ϕ Meson in Au +Au Collisions at √{sN N}=200 GeV

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Bairathi, V.; Banerjee, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandin, A. V.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cervantes, M. C.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, J. H.; Chen, X.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, S.; Gupta, A.; Guryn, W.; Hamad, A.; Hamed, A.; Haque, R.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, X.; Huang, B.; Huang, H. Z.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Jiang, K.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikoła, D. P.; Kisel, I.; Kisiel, A.; Kochenda, L.; Koetke, D. D.; Kollegger, T.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, Z. M.; Li, W.; Li, X.; Li, X.; Li, C.; Li, Y.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, Y. G.; Ma, G. L.; Ma, L.; Ma, R.; Magdy, N.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; Meehan, K.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V.; Olvitt, D.; Page, B. S.; Pak, R.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Peterson, A.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Sharma, M. K.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stepanov, M.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B.; Sun, X.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, N.; Szelezniak, M. A.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Tawfik, A.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, Y.; Wang, G.; Wang, J. S.; Wang, H.; Wang, Y.; Wang, F.; Webb, J. C.; Webb, G.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Wu, Y.; Xiao, Z. G.; Xie, W.; Xin, K.; Xu, N.; Xu, Z.; Xu, Q. H.; Xu, Y. F.; Xu, H.; Yang, Q.; Yang, Y.; Yang, Y.; Yang, S.; Yang, C.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, Z.; Zhang, Y.; Zhang, J. B.; Zhang, J.; Zhang, S.; Zhang, J.; Zhang, X. P.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2016-02-01

    We present high precision measurements of elliptic flow near midrapidity (|y |<1.0 ) for multistrange hadrons and ϕ meson as a function of centrality and transverse momentum in Au +Au collisions at center of mass energy √{sN N}=200 GeV . We observe that the transverse momentum dependence of ϕ and Ω v2 is similar to that of π and p , respectively, which may indicate that the heavier strange quark flows as strongly as the lighter up and down quarks. This observation constitutes a clear piece of evidence for the development of partonic collectivity in heavy-ion collisions at the top RHIC energy. Number of constituent quark scaling is found to hold within statistical uncertainty for both 0%-30% and 30%-80% collision centrality. There is an indication of the breakdown of previously observed mass ordering between ϕ and proton v2 at low transverse momentum in the 0%-30% centrality range, possibly indicating late hadronic interactions affecting the proton v2.

  16. Centrality dependence of charged hadron and strange hadron elliptic flow from sNN=200 GeV Au+Au collisions

    NASA Astrophysics Data System (ADS)

    Abelev, B. I.; Aggarwal, M. M.; Ahammed, Z.; Anderson, B. D.; Arkhipkin, D.; Averichev, G. S.; Bai, Y.; Balewski, J.; Barannikova, O.; Barnby, L. S.; Baudot, J.; Baumgart, S.; Beavis, D. R.; Bellwied, R.; Benedosso, F.; Betts, R. R.; Bhardwaj, S.; Bhasin, A.; Bhati, A. K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bombara, M.; Bonner, B. E.; Botje, M.; Braidot, E.; Brandin, A. V.; Bueltmann, S.; Burton, T. P.; Bystersky, M.; Cai, X. Z.; Caines, H.; de La Barca Sánchez, M. Calderón; Callner, J.; Catu, O.; Cebra, D.; Cervantes, M. C.; Chajecki, Z.; Chaloupka, P.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, J. Y.; Cheng, J.; Cherney, M.; Chikanian, A.; Choi, K. E.; Christie, W.; Chung, S. U.; Clarke, R. F.; Codrington, M. J. M.; Coffin, J. P.; Cormier, T. M.; Cosentino, M. R.; Cramer, J. G.; Crawford, H. J.; Das, D.; Dash, S.; Daugherity, M.; de Moura, M. M.; Dedovich, T. G.; Dephillips, M.; Derevschikov, A. A.; Souza, R. Derradi De; Didenko, L.; Dietel, T.; Djawotho, P.; Dogra, S. M.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, F.; Dunlop, J. C.; Mazumdar, M. R. Dutta; Edwards, W. R.; Efimov, L. G.; Elhalhuli, E.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Eun, L.; Fachini, P.; Fatemi, R.; Fedorisin, J.; Feng, A.; Filip, P.; Finch, E.; Fine, V.; Fisyak, Y.; Gagliardi, C. A.; Gaillard, L.; Ganti, M. S.; Garcia-Solis, E.; Ghazikhanian, V.; Ghosh, P.; Gorbunov, Y. N.; Gordon, A.; Grebenyuk, O.; Grosnick, D.; Grube, B.; Guertin, S. M.; Gupta, A.; Gupta, N.; Guryn, W.; Haag, B.; Hallman, T. J.; Hamed, A.; Harris, J. W.; He, W.; Heinz, M.; Heppelmann, S.; Hippolyte, B.; Hirsch, A.; Hoffman, A. M.; Hoffmann, G. W.; Hofman, D. J.; Hollis, R. S.; Huang, H. Z.; Hughes, E. W.; Humanic, T. J.; Igo, G.; Iordanova, A.; Jacobs, P.; Jacobs, W. W.; Jakl, P.; Jin, F.; Jones, P. G.; Judd, E. G.; Kabana, S.; Kajimoto, K.; Kang, K.; Kapitan, J.; Kaplan, M.; Keane, D.; Kechechyan, A.; Kettler, D.; Khodyrev, V. Yu.; Kiryluk, J.; Kisiel, A.; Klein, S. R.; Knospe, A. G.; Kocoloski, A.; Koetke, D. D.; Kollegger, T.; Kopytine, M.; Kotchenda, L.; Kouchpil, V.; Kravtsov, P.; Kravtsov, V. I.; Krueger, K.; Kuhn, C.; Kumar, A.; Kumar, L.; Kurnadi, P.; Lamont, M. A. C.; Landgraf, J. M.; Lange, S.; Lapointe, S.; Laue, F.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, C.-H.; Levine, M. J.; Li, C.; Li, Y.; Lin, G.; Lin, X.; Lindenbaum, S. J.; Lisa, M. A.; Liu, F.; Liu, H.; Liu, J.; Liu, L.; Ljubicic, T.; Llope, W. J.; Longacre, R. S.; Love, W. A.; Lu, Y.; Ludlam, T.; Lynn, D.; Ma, G. L.; Ma, J. G.; Ma, Y. G.; Mahapatra, D. P.; Majka, R.; Mangotra, L. K.; Manweiler, R.; Margetis, S.; Markert, C.; Matis, H. S.; Matulenko, Yu. A.; McShane, T. S.; Meschanin, A.; Millane, J.; Miller, M. L.; Minaev, N. G.; Mioduszewski, S.; Mischke, A.; Mitchell, J.; Mohanty, B.; Morozov, D. A.; Munhoz, M. G.; Nandi, B. K.; Nattrass, C.; Nayak, T. K.; Nelson, J. M.; Nepali, C.; Netrakanti, P. K.; Ng, M. J.; Nogach, L. V.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Okada, H.; Okorokov, V.; Oldenburg, M.; Olson, D.; Pachr, M.; Pal, S. K.; Panebratsev, Y.; Pawlak, T.; Peitzmann, T.; Perevoztchikov, V.; Perkins, C.; Peryt, W.; Phatak, S. C.; Planinic, M.; Pluta, J.; Poljak, N.; Porile, N.; Poskanzer, A. M.; Potekhin, M.; Potukuchi, B. V. K. S.; Prindle, D.; Pruneau, C.; Pruthi, N. K.; Putschke, J.; Qattan, I. A.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Relyea, D.; Ridiger, A.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Rose, A.; Roy, C.; Ruan, L.; Russcher, M. J.; Rykov, V.; Sahoo, R.; Sakrejda, I.; Sakuma, T.; Salur, S.; Sandweiss, J.; Sarsour, M.; Schambach, J.; Scharenberg, R. P.; Schmitz, N.; Schweda, K.; Seger, J.; Selyuzhenkov, I.; Seyboth, P.; Shabetai, A.; Shahaliev, E.; Shao, M.; Sharma, M.; Shi, S. S.; Shi, X.-H.; Sichtermann, E. P.; Simon, F.; Singaraju, R. N.; Skoby, M. J.; Smirnov, N.; Snellings, R.; Sorensen, P.; Sowinski, J.; Spinka, H. M.; Srivastava, B.; Stadnik, A.; Stanislaus, T. D. S.; Staszak, D.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Suarez, M. C.; Subba, N. L.; Sumbera, M.; Sun, X. M.; Sun, Z.; Surrow, B.; Symons, T. J. M.; Toledo, A. Szanto De; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thein, D.; Thomas, J. H.; Tian, J.; Timmins, A. R.; Timoshenko, S.; Tokarev, M.; Tram, V. N.; Trattner, A. L.; Trentalange, S.; Tribble, R. E.; Tsai, O. D.; Ulery, J.; Ullrich, T.; Underwood, D. G.; Buren, G. Van; Kolk, N. Van Der; Leeuwen, M. Van; Molen, A. M. Vander; Varma, R.; Vasconcelos, G. M. S.; Vasilevski, I. M.; Vasiliev, A. N.; Videbaek, F.; Vigdor, S. E.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Wada, M.; Waggoner, W. T.; Wang, F.; Wang, G.; Wang, J. S.; Wang, Q.; Wang, X.; Wang, X. L.; Wang, Y.; Webb, J. C.; Westfall, G. D.; , C. Whitten, Jr.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, J.; Wu, Y.; Xu, N.; Xu, Q. H.; Xu, Z.; Yepes, P.; Yoo, I.-K.; Yue, Q.; Zawisza, M.; Zbroszczyk, H.; Zhan, W.; Zhang, H.; Zhang, S.; Zhang, W. M.; Zhang, Y.; Zhang, Z. P.; Zhao, Y.; Zhong, C.; Zhou, J.; Zoulkarneev, R.; Zoulkarneeva, Y.; Zuo, J. X.

    2008-05-01

    We present STAR results on the elliptic flow v2 of charged hadrons, strange and multistrange particles from sNN=200 GeV Au+Au collisions at the BNL Relativistic Heavy Ion Collider (RHIC). The detailed study of the centrality dependence of v2 over a broad transverse momentum range is presented. Comparisons of different analysis methods are made in order to estimate systematic uncertainties. To discuss the nonflow effect, we have performed the first analysis of v2 with the Lee-Yang zero method for KS0 and Λ. In the relatively low pT region, pT⩽2GeV/c, a scaling with mT-m is observed for identified hadrons in each centrality bin studied. However, we do not observe v2(pT) scaled by the participant eccentricity to be independent of centrality. At higher pT,2⩽pT⩽6GeV/c,v2 scales with quark number for all hadrons studied. For the multistrange hadron Ω, which does not suffer appreciable hadronic interactions, the values of v2 are consistent with both mT-m scaling at low pT and number-of-quark scaling at intermediate pT. As a function of collision centrality, an increase of pT-integrated v2 scaled by the participant eccentricity has been observed, indicating a stronger collective flow in more central Au+Au collisions.

  17. On the X-ray spectra of luminous, inhomogeneous accretion flows

    NASA Astrophysics Data System (ADS)

    Merloni, A.; Malzac, J.; Fabian, A. C.; Ross, R. R.

    2006-08-01

    We discuss the expected X-ray spectral and variability properties of black hole accretion discs at high luminosity, under the hypothesis that radiation-pressure-dominated discs are subject to violent clumping instabilities and, as a result, have a highly inhomogeneous two-phase structure. After deriving the full accretion disc solutions explicitly in terms of the parameters of the model, we study their radiative properties both with a simple two-zone model, treatable analytically, and with radiative transfer simulations which account simultaneously for energy balance and Comptonization in the hot phase, together with reflection, reprocessing, ionization and thermal balance in the cold phase. We show that, if not only the density, but also the heating rate within these flows is inhomogeneous, then complex reflection-dominated spectra can be obtained for a high enough covering fraction of the cold phase. In general, large reflection components in the observed X-ray spectra should be associated with strong soft excesses, resulting from the combined emission of ionized atomic emission lines. The variability properties of such systems are such that, even when contributing to a large fraction of the hard X-ray spectrum, the reflection component is less variable than the power-law-like emission originating from the hot Comptonizing phase, in agreement with what is observed in many Narrow Line Seyfert 1 galaxies and bright Seyfert 1. Our model falls within the family of those trying to explain the complex X-ray spectra of bright AGN with ionized reflection, but presents an alternative, specific, physically motivated, geometrical set-up for the complex multiphase structure of the inner regions of near-Eddington accretion flows.

  18. Elliptic and hexadecapole flow of charged hadrons in Au+Au collisions at sq.rt(s(NN))=200  GeV.

    PubMed

    Adare, A; Afanasiev, S; Aidala, C; Ajitanand, N N; Akiba, Y; Al-Bataineh, H; Alexander, J; Aoki, K; Aramaki, Y; Atomssa, E T; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Bai, M; Baksay, G; Baksay, L; Barish, K N; Bassalleck, B; Basye, A T; Bathe, S; Baublis, V; Baumann, C; Bazilevsky, A; Belikov, S; Belmont, R; Bennett, R; Berdnikov, A; Berdnikov, Y; Bickley, A A; Bok, J S; Boyle, K; Brooks, M L; Buesching, H; Bumazhnov, V; Bunce, G; Butsyk, S; Camacho, C M; Campbell, S; Chen, C-H; Chi, C Y; Chiu, M; Choi, I J; Choudhury, R K; Christiansen, P; Chujo, T; Chung, P; Chvala, O; Cianciolo, V; Citron, Z; Cole, B A; Connors, M; Constantin, P; Csanád, M; Csörgo, T; Dahms, T; Dairaku, S; Danchev, I; Das, K; Datta, A; David, G; Denisov, A; Deshpande, A; Desmond, E J; Dietzsch, O; Dion, A; Donadelli, M; Drapier, O; Drees, A; Drees, K A; Durham, J M; Durum, A; Dutta, D; Edwards, S; Efremenko, Y V; Ellinghaus, F; Engelmore, T; Enokizono, A; En'yo, H; Esumi, S; Fadem, B; Fields, D E; Finger, M; Finger, M; Fleuret, F; Fokin, S L; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fujiwara, K; Fukao, Y; Fusayasu, T; Garishvili, I; Glenn, A; Gong, H; Gonin, M; Goto, Y; Granier de Cassagnac, R; Grau, N; Greene, S V; Grosse Perdekamp, M; Gunji, T; Gustafsson, H-A; Haggerty, J S; Hahn, K I; Hamagaki, H; Hamblen, J; Hanks, J; Han, R; Hartouni, E P; Haslum, E; Hayano, R; Heffner, M; Hegyi, S; Hemmick, T K; Hester, T; He, X; Hill, J C; Hohlmann, M; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hornback, D; Huang, S; Ichihara, T; Ichimiya, R; Ide, J; Ikeda, Y; Imai, K; Inaba, M; Isenhower, D; Ishihara, M; Isobe, T; Issah, M; Isupov, A; Ivanischev, D; Jacak, B V; Jia, J; Jin, J; Johnson, B M; Joo, K S; Jouan, D; Jumper, D S; Kajihara, F; Kametani, S; Kamihara, N; Kamin, J; Kang, J H; Kapustinsky, J; Karatsu, K; Kawall, D; Kawashima, M; Kazantsev, A V; Kempel, T; Khanzadeev, A; Kijima, K M; Kim, B I; Kim, D H; Kim, D J; Kim, E J; Kim, E; Kim, S H; Kim, Y J; Kinney, E; Kiriluk, K; Kiss, A; Kistenev, E; Kochenda, L; Komkov, B; Konno, M; Koster, J; Kotchetkov, D; Kozlov, A; Král, A; Kravitz, A; Kunde, G J; Kurita, K; Kurosawa, M; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y S; Lajoie, J G; Lebedev, A; Lee, D M; Lee, J; Lee, K B; Lee, K; Lee, K S; Leitch, M J; Leite, M A L; Leitner, E; Lenzi, B; Liebing, P; Linden Levy, L A; Liska, T; Litvinenko, A; Liu, H; Liu, M X; Li, X; Love, B; Luechtenborg, R; Lynch, D; Maguire, C F; Makdisi, Y I; Malakhov, A; Malik, M D; Manko, V I; Mannel, E; Mao, Y; Masui, H; Matathias, F; McCumber, M; McGaughey, P L; Means, N; Meredith, B; Miake, Y; Mignerey, A C; Mikes, P; Miki, K; Milov, A; Mishra, M; Mitchell, J T; Mohanty, A K; Morino, Y; Morreale, A; Morrison, D P; Moukhanova, T V; Murata, J; Nagamiya, S; Nagle, J L; Naglis, M; Nagy, M I; Nakagawa, I; Nakamiya, Y; Nakamura, T; Nakano, K; Newby, J; Nguyen, M; Nouicer, R; Nyanin, A S; O'Brien, E; Oda, S X; Ogilvie, C A; Okada, K; Oka, M; Onuki, Y; Oskarsson, A; Ouchida, M; Ozawa, K; Pak, R; Pantuev, V; Papavassiliou, V; Park, I H; Park, J; Park, S K; Park, W J; Pate, S F; Pei, H; Peng, J-C; Pereira, H; Peresedov, V; Peressounko, D Yu; Pinkenburg, C; Pisani, R P; Proissl, M; Purschke, M L; Purwar, A K; Qu, H; Rak, J; Rakotozafindrabe, A; Ravinovich, I; Read, K F; Reygers, K; Riabov, V; Riabov, Y; Richardson, E; Roach, D; Roche, G; Rolnick, S D; Rosati, M; Rosen, C A; Rosendahl, S S E; Rosnet, P; Rukoyatkin, P; Ruzicka, P; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakashita, K; Samsonov, V; Sano, S; Sato, T; Sawada, S; Sedgwick, K; Seele, J; Seidl, R; Semenov, A Yu; Seto, R; Sharma, D; Shein, I; Shibata, T-A; Shigaki, K; Shimomura, M; Shoji, K; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Silvestre, C; Sim, K S; Singh, B K; Singh, C P; Singh, V; Slunecka, M; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Sparks, N A; Stankus, P W; Stenlund, E; Stoll, S P; Sugitate, T; Sukhanov, A; Sziklai, J; Takagui, E M; Taketani, A; Tanabe, R; Tanaka, Y; Tanida, K; Tannenbaum, M J; Tarafdar, S; Taranenko, A; Tarján, P; Themann, H; Thomas, T L; Togawa, M; Toia, A; Tomásek, L; Torii, H; Towell, R S; Tserruya, I; Tsuchimoto, Y; Vale, C; Valle, H; van Hecke, H W; Vazquez-Zambrano, E; Veicht, A; Velkovska, J; Vértesi, R; Vinogradov, A A; Virius, M; Vrba, V; Vznuzdaev, E; Wang, X R; Watanabe, D; Watanabe, K; Watanabe, Y; Wei, F; Wei, R; Wessels, J; White, S N; Winter, D; Wood, J P; Woody, C L; Wright, R M; Wysocki, M; Xie, W; Yamaguchi, Y L; Yamaura, K; Yang, R; Yanovich, A; Ying, J; Yokkaichi, S; Young, G R; Younus, I; You, Z; Yushmanov, I E; Zajc, W A; Zhang, C; Zhou, S; Zolin, L

    2010-08-01

    Differential measurements of the elliptic (v(2)) and hexadecapole (v(4)) Fourier flow coefficients are reported for charged hadrons as a function of transverse momentum (p(T)) and collision centrality or number of participant nucleons (N(part)) for Au+Au collisions at sq.rt(s(NN))=200  GeV. The v(2,4) measurements at pseudorapidity |η|≤0.35, obtained with four separate reaction-plane detectors positioned in the range 1.0<|η|<3.9, show good agreement, indicating the absence of significant Δη-dependent nonflow correlations. Sizable values for v(4)(p(T)) are observed with a ratio v(4)(p(T),N(part))/v(2)(2)(p(T),N(part))≈0.8 for 50≲N(part)≲200, which is compatible with the combined effects of a finite viscosity and initial eccentricity fluctuations. For N(part)≳200 this ratio increases up to 1.7 in the most central collisions. PMID:20867976

  19. Elliptic and Hexadecapole Flow of Charged Hadrons in Au+Au Collisions at {radical}(s{sub NN})=200 GeV

    SciTech Connect

    Adare, A.; Bickley, A. A.; Ellinghaus, F.; Glenn, A.; Kinney, E.; Kiriluk, K.; Linden Levy, L. A.; Nagle, J. L.; Rosen, C. A.; Seele, J.; Wysocki, M.; Afanasiev, S.; Isupov, A.; Litvinenko, A.; Malakhov, A.; Peresedov, V.; Rukoyatkin, P.; Zolin, L.; Aidala, C.; Datta, A.

    2010-08-06

    Differential measurements of the elliptic (v{sub 2}) and hexadecapole (v{sub 4}) Fourier flow coefficients are reported for charged hadrons as a function of transverse momentum (p{sub T}) and collision centrality or number of participant nucleons (N{sub part}) for Au+Au collisions at {radical}(s{sub NN})=200 GeV. The v{sub 2,4} measurements at pseudorapidity |{eta}|{<=}0.35, obtained with four separate reaction-plane detectors positioned in the range 1.0<|{eta}|<3.9, show good agreement, indicating the absence of significant {Delta}{eta}-dependent nonflow correlations. Sizable values for v{sub 4}(p{sub T}) are observed with a ratio v{sub 4}(p{sub T},N{sub part})/v{sub 2}{sup 2}(p{sub T},N{sub part}){approx_equal}0.8 for 50 < or approx. IN{sub part} < or approx. 200, which is compatible with the combined effects of a finite viscosity and initial eccentricity fluctuations. For N{sub part} > or approx. 200 this ratio increases up to 1.7 in the most central collisions.

  20. Enhanced Elliptic Grid Generation

    NASA Technical Reports Server (NTRS)

    Kaul, Upender K.

    2007-01-01

    An enhanced method of elliptic grid generation has been invented. Whereas prior methods require user input of certain grid parameters, this method provides for these parameters to be determined automatically. "Elliptic grid generation" signifies generation of generalized curvilinear coordinate grids through solution of elliptic partial differential equations (PDEs). Usually, such grids are fitted to bounding bodies and used in numerical solution of other PDEs like those of fluid flow, heat flow, and electromagnetics. Such a grid is smooth and has continuous first and second derivatives (and possibly also continuous higher-order derivatives), grid lines are appropriately stretched or clustered, and grid lines are orthogonal or nearly so over most of the grid domain. The source terms in the grid-generating PDEs (hereafter called "defining" PDEs) make it possible for the grid to satisfy requirements for clustering and orthogonality properties in the vicinity of specific surfaces in three dimensions or in the vicinity of specific lines in two dimensions. The grid parameters in question are decay parameters that appear in the source terms of the inhomogeneous defining PDEs. The decay parameters are characteristic lengths in exponential- decay factors that express how the influences of the boundaries decrease with distance from the boundaries. These terms govern the rates at which distance between adjacent grid lines change with distance from nearby boundaries. Heretofore, users have arbitrarily specified decay parameters. However, the characteristic lengths are coupled with the strengths of the source terms, such that arbitrary specification could lead to conflicts among parameter values. Moreover, the manual insertion of decay parameters is cumbersome for static grids and infeasible for dynamically changing grids. In the present method, manual insertion and user specification of decay parameters are neither required nor allowed. Instead, the decay parameters are

  1. Hot versus Cold: the Dichotomy in Spherical Accretion of Cooling Flows onto Supermassive Black Holes in Elliptical Galaxies, Galaxy Groups, and Clusters

    NASA Astrophysics Data System (ADS)

    Guo, Fulai; Mathews, William G.

    2014-01-01

    Feedback heating from active galactic nuclei (AGNs) has been commonly invoked to suppress cooling flows predicted in hot gas in elliptical galaxies, galaxy groups, and clusters. Previous studies have focused on if and how AGN feedback heats the gas but have little paid attention to its triggering mechanism. Using spherically symmetric simulations, we investigate how large-scale cooling flows are accreted by central supermassive black holes (SMBHs) in eight well-observed systems and find an interesting dichotomy. In massive clusters, the gas develops a central cooling catastrophe within about the cooling time (typically ~100-300 Myr), resulting in cold-mode accretion onto SMBHs. However, in our four simulated systems on group and galaxy scales at a low metallicity Z = 0.3 Z ⊙, the gas quickly settles into a long-term state that has a cuspy central temperature profile extending to several tens to about 100 pc. At the more realistic solar metallicity, two groups (with R e ~ 4 kpc) still host the long-term, hot-mode accretion. Both accretion modes naturally appear in our idealized calculations where only cooling, gas inflow, and compressional heating are considered. The long-term, hot-mode accretion is maintained by the quickly established closeness between the timescales of these processes, preferably in systems with low gas densities, low gas metallicities, and importantly, compact central galaxies, which result in strong gravitational acceleration and compressional heating at the intermediate radii. Our calculations predict that central cuspy temperature profiles appear more often in smaller systems than galaxy clusters, which instead often host significant cold gas and star formation.

  2. Centrality dependence of charged hadron and strange hadron elliptic flow from {radical}{ovr s} {sub NN} =200 GeV Au+Au collisions.

    SciTech Connect

    Abelev, B. I.; Aggarwal, M. M.; Ahammed, Z.; Anderson, B. D.; Arkhipkin, D.; Krueger, K.; Spinka, H. M.; Underwood, D. G.; High Energy Physics; Univ. of Illinois; Panjab Univ.; Variable Energy Cyclotron; Kent State Univ.; Particle Physic Lab.; STAR Collaboration

    2008-01-01

    We present STAR results on the elliptic flow v{sub 2} of charged hadrons, strange and multistrange particles from {radical}s{sub NN} = 200 GeV Au+Au collisions at the BNL Relativistic Heavy Ion Collider (RHIC). The detailed study of the centrality dependence of v{sub 2} over a broad transverse momentum range is presented. Comparisons of different analysis methods are made in order to estimate systematic uncertainties. To discuss the nonflow effect, we have performed the first analysis of v{sub 2} with the Lee-Yang zero method for KS{sup 0} and {Lambda}. In the relatively low p{sub T} region, p{sub T} {le} 2 GeV/c, a scaling with m{sub T}-m is observed for identified hadrons in each centrality bin studied. However, we do not observe v{sub 2}(p{sub T}) scaled by the participant eccentricity to be independent of centrality. At higher p{sub T},2 {le} p{sub T} {le} 6 GeV/c,v{sub 2} scales with quark number for all hadrons studied. For the multistrange hadron {Omega}, which does not suffer appreciable hadronic interactions, the values of v{sub 2} are consistent with both m{sub T}-m scaling at low p{sub T} and number-of-quark scaling at intermediate p{sub T}. As a function of collision centrality, an increase of p{sub T}-integrated v{sub 2} scaled by the participant eccentricity has been observed, indicating a stronger collective flow in more central Au+Au collisions.

  3. Hot versus cold: The dichotomy in spherical accretion of cooling flows onto supermassive black holes in elliptical galaxies, galaxy groups, and clusters

    SciTech Connect

    Guo, Fulai; Mathews, William G.

    2014-01-10

    Feedback heating from active galactic nuclei (AGNs) has been commonly invoked to suppress cooling flows predicted in hot gas in elliptical galaxies, galaxy groups, and clusters. Previous studies have focused on if and how AGN feedback heats the gas but have little paid attention to its triggering mechanism. Using spherically symmetric simulations, we investigate how large-scale cooling flows are accreted by central supermassive black holes (SMBHs) in eight well-observed systems and find an interesting dichotomy. In massive clusters, the gas develops a central cooling catastrophe within about the cooling time (typically ∼100-300 Myr), resulting in cold-mode accretion onto SMBHs. However, in our four simulated systems on group and galaxy scales at a low metallicity Z = 0.3 Z {sub ☉}, the gas quickly settles into a long-term state that has a cuspy central temperature profile extending to several tens to about 100 pc. At the more realistic solar metallicity, two groups (with R {sub e} ∼ 4 kpc) still host the long-term, hot-mode accretion. Both accretion modes naturally appear in our idealized calculations where only cooling, gas inflow, and compressional heating are considered. The long-term, hot-mode accretion is maintained by the quickly established closeness between the timescales of these processes, preferably in systems with low gas densities, low gas metallicities, and importantly, compact central galaxies, which result in strong gravitational acceleration and compressional heating at the intermediate radii. Our calculations predict that central cuspy temperature profiles appear more often in smaller systems than galaxy clusters, which instead often host significant cold gas and star formation.

  4. Elliptic flow in U+U collisions at sNN=200 GeV and in Pb+Pb collisions at sNN=2.76 TeV: Prediction from a hybrid approach

    NASA Astrophysics Data System (ADS)

    Hirano, Tetsufumi; Huovinen, Pasi; Nara, Yasushi

    2011-02-01

    We predict the elliptic flow parameter v2 in U+U collisions at sNN=200 GeV and in Pb+Pb collisions at sNN=2.76 TeV using a hybrid model in which the evolution of the quark gluon plasma is described by ideal hydrodynamics with a state-of-the-art lattice QCD equation of state and the subsequent hadronic stage is described by a hadron cascade model.

  5. J/ψ elliptic flow measurement in Pb-Pb collisions at √{sNN} = 2.76 TeV at forward rapidity with the ALICE experiment

    NASA Astrophysics Data System (ADS)

    Massacrier, L.

    2013-08-01

    J/ψ suppression induced by color screening of its constituent quarks was proposed 26 years ago as a signature of the formation of a quark gluon plasma in heavy-ion collisions. Recent results from ALICE in Pb-Pb collisions exhibit a smaller suppression with respect to previous measurements at the SPS and RHIC. The study of azimuthal anisotropy in particle production gives information on the collective hydrodynamic expansion at the early stage of the fireball, where the matter created in high-energy nuclear collisions is expected to be in a deconfined state. In particular, J/ψ elliptic flow v2 is important to test the degree of thermalization of heavy quarks. Together with the production yields, the elliptic flow is a powerful observable to address the question of suppression and regeneration of J/ψ in QGP. We present the first inclusive J/ψ elliptic flow measurement performed with the muon spectrometer of ALICE, in Pb-Pb collisions, at forward rapidity. Integrated and pT-differential v2 results are presented and a comparison with recent STAR results and with a parton transport model is also performed.

  6. On the '-1' scaling of air temperature spectra in atmospheric surface layer flows

    NASA Astrophysics Data System (ADS)

    Li, D.; Katul, G. G.; Gentine, P.

    2015-12-01

    The spectral properties of scalar turbulence at high wavenumbers have been extensively studied in turbulent flows, and existing theories explaining the k-5/3 scaling within the inertial subrange appear satisfactory at high Reynolds numbers. Equivalent theories for the low wavenumber range have been comparatively lacking because boundary conditions prohibit attainment of such universal behavior. A number of atmospheric surface layer (ASL) experiments reported a k-1 scaling in air temperature spectra ETT(k) at low wavenumbers but other experiments did not. Here, the occurrence of a k-1 scaling in ETT(k) in an idealized ASL flow across a wide range of atmospheric stability regimes is investigated theoretically and experimentally. Experiments reveal a k-1 scaling persisted across different atmospheric stability parameter values (ζ) ranging from mildly unstable to mildly stable conditions (-0.1< ζ < 0.2). As instability increases, the k-1 scaling vanishes. Based on a combined spectral and co-spectral budget models and upon using a Heisenberg eddy viscosity as a closure to the spectral flux transfer term, conditions promoting a k-1 scaling are identified. Existence of a k-1 scaling is shown to be primarily linked to an imbalance between the production and dissipation rates of half the temperature variance. The role of the imbalance between the production and dissipation rates of half the temperature variance in controlling the existence of a '-1' scaling suggests that the '-1' scaling in ETT(k) does not necessarily concur with the '-1' scaling in the spectra of longitudinal velocity Euu(k). This finding explains why some ASL experiments reported k-1 in Euu(k) but not ETT(k). It also differs from prior arguments derived from directional-dimensional analysis that lead to simultaneous k-1 scaling in Euu(k) and ETT(k) at low wavenumbers in a neutral ASL.

  7. Detection of zonal flow spectra in DIII-D by a dual-channel Doppler backscattering system

    SciTech Connect

    Schmitz, L.; Wang, G.; Hillesheim, J. C.; Rhodes, T. L.; Peebles, W. A.; White, A. E.; Zeng, L.; Carter, T. A.; Solomon, W.

    2008-10-15

    Doppler backscattering (DBS) has been successfully used to measure the ExB flow velocity and local intermediate wavenumber density fluctuation levels in the DIII-D tokamak. Depending on the launch angle and the frequency of the probing beam, the signal backscattered from the plasma cut-off layer is sensitive to density fluctuations at a specific perpendicular wavenumber (1{<=}k{sub perpendicular}{rho}{sub s}{<=}4). Due to the localization and high time resolution for poloidal flow measurements, DBS is well suited to detect stationary and time-dependent shear flows [zonal flows (ZFs)]. We present a novel scheme to measure ZF spectra using a dual-channel DBS system capable of simultaneously probing two minor radii separated by a distance of 0.2 cm<{delta}r<3 cm. Frequency spectra of geodesic acoustic modes and low frequency ZFs (f{<=}10 kHz) have been obtained for 0.6

  8. Non-elliptic wavevector anisotropy for magnetohydrodynamic turbulence

    NASA Astrophysics Data System (ADS)

    Narita, Y.

    2015-11-01

    A model of non-elliptic wavevector anisotropy is developed for the inertial-range spectrum of magnetohydrodynamic turbulence and is presented in the two-dimensional wavevector domain spanning the directions parallel and perpendicular to the mean magnetic field. The non-elliptic model is a variation of the elliptic model with different scalings along the parallel and the perpendicular components of the wavevectors to the mean magnetic field. The non-elliptic anisotropy model reproduces the smooth transition of the power-law spectra from an index of -2 in the parallel projection with respect to the mean magnetic field to an index of -5/3 in the perpendicular projection observed in solar wind turbulence, and is as competitive as the critical balance model to explain the measured frequency spectra in the solar wind. The parameters in the non-elliptic spectrum model are compared with the solar wind observations.

  9. Dynamic susceptibility of onion in ferromagnetic elliptical nanoring

    NASA Astrophysics Data System (ADS)

    Mu, Congpu; Song, Jiefang; Xu, Jianghong; Wen, Fusheng

    2016-06-01

    Micromagnetic simulation was performed to investigate the equilibrium state and dynamic susceptibility spectra of magnetic elliptical nanoring. There are two equilibrium states (onion and vortex) obtained in elliptical nanoring. The onion state can be used to record information in MRAM. And it is important to investigate the dynamic susceptibility spectra of onion state, which is closely related to writing and reading speed of magnetic memory devices. Those results show that two or three resonance peaks are found under different thickness of elliptical nanoring with onion state, respectively. The low resonance frequency of two resonance peaks is increasing with the arm width of the elliptical ring, but is decreasing with the thickness. However, the high frequency of two resonance peaks is decreasing with the arm width of the elliptical ring.

  10. The Stellar Population Histories of Elliptical Galaxies

    NASA Astrophysics Data System (ADS)

    Trager, Scott Charles

    1997-08-01

    This dissertation sets out to probe the stellar population histories of local field and distant cluster elliptical galaxies. Absorption-line strengths of the centers of 381 early-type galaxies and 38 globular clusters measured from the Lick Image Dissector Scanner (Lick/IDS) are presented. Error estimation and corrections for velocity-dispersion broadening are described in detail. Monte Carlo simulations show that the Lick/IDS data are not accurate enough to infer ages and abundances of individual ellipticals with confidence. The excellent data of Gonzalez (1993) are therefore used to infer the stellar population ages and abundances of the centers of local field ellipticals. Elliptical galaxy nuclei follow three relations in this sample. (1) The t-Z relation. Elliptical nuclei have an age-abundance relation at fixed velocity dispersion σ that follows the Worthey (1994) '3/2 rule.' Ellipticals therefore have fixed color and metal-line strengths at fixed σ. (2) The σ-Z relation. The abundance zeropoint of the t-Z relation increases with increasing σ. Taken together, (1) and (2) predict scaling relations like the Mg2-σ and color-magnitude relations. (3) The σ- (Mg/Fe) relation. The abundance ratio (Mg/Fe) increases with increasing σ, as the σ-Z relation for Mg has twice the slope of the σ-Z relation for Fe. Relations (1)-(3) can be expressed as a pair of planes in t-Z-σ space, one for Fe and one for Mg, with similar age dependences but different σ-dependences. Scenarios for the possible origins of these relations are presented. Absorption-line strengths of eighteen early-type galaxies in two rich clusters at z = 0.41 (CL0939 + 4713) and z = 0.76 (CL1322 + 3027) have been measured from Keck LRIS spectra. The Balmer-line strengths of ellipticals at z = 0.41 are consistent with passive evolution of local field ellipticals but seem too metal-rich. Both Balmer- and metal-line strengths of ellipticals at z = 0.76 are consistent with passive evolution of local

  11. Planar elliptic growth

    SciTech Connect

    Mineev, Mark

    2008-01-01

    The planar elliptic extension of the Laplacian growth is, after a proper parametrization, given in a form of a solution to the equation for areapreserving diffeomorphisms. The infinite set of conservation laws associated with such elliptic growth is interpreted in terms of potential theory, and the relations between two major forms of the elliptic growth are analyzed. The constants of integration for closed form solutions are identified as the singularities of the Schwarz function, which are located both inside and outside the moving contour. Well-posedness of the recovery of the elliptic operator governing the process from the continuum of interfaces parametrized by time is addressed and two examples of exact solutions of elliptic growth are presented.

  12. Dependence of Elliptic Flow on Transverse Momentum in √sNN = 200 GeV Au-Au and √sNN = 2.76 TeV Pb-Pb Collisions

    NASA Astrophysics Data System (ADS)

    Li, Bao-Chun; Fu, Yuan-Yuan; Wang, Li-Li; Wang, Er-Qin; Wen, Xin-Jian; Liu, Fu-Hu

    2012-07-01

    We investigate the dependence of elliptic flows v2 on transverse momentum PT for charged hadrons produced in nucleus-nucleus collisions at high energy by using a multi-source thermal model, where the contribution of source interactions is considered. Our calculated results are approximately in agreement with the experimental data over a wider PT range from the PHENIX and ALICE collaborations. It is found that the expansion factor increases linearly with the impact parameter from most central (0-5%) to mid-peripheral (35-40%) collisions.

  13. Elliptic flow in U+U collisions at {radical}(s{sub NN})=200 GeV and in Pb+Pb collisions at {radical}(s{sub NN})=2.76 TeV: Prediction from a hybrid approach

    SciTech Connect

    Hirano, Tetsufumi; Huovinen, Pasi; Nara, Yasushi

    2011-02-15

    We predict the elliptic flow parameter v{sub 2} in U+U collisions at {radical}(s{sub NN})=200 GeV and in Pb+Pb collisions at {radical}(s{sub NN})=2.76 TeV using a hybrid model in which the evolution of the quark gluon plasma is described by ideal hydrodynamics with a state-of-the-art lattice QCD equation of state and the subsequent hadronic stage is described by a hadron cascade model.

  14. A comparison of the Doppler spectra from human blood and artificial blood used in a flow phantom.

    PubMed

    Hoskins, P R; Loupas, T; McDicken, W N

    1990-01-01

    A comparison between the Doppler signals from human blood and artificial blood used in a flow phantom is described. The artificial blood used was a suspension of Sephadex particles in a glycerol solution. The Doppler power was measured as a function of Sephadex concentration and found to peak at a concentration of about 40% by volume. The power from blood was less by a factor of 150-250 than the power from Sephadex of a similar concentration. The first and second order statistics of the Doppler spectra from Sephadex were independent of particle concentration, and were very similar to those of spectra from blood. PMID:1691560

  15. Remote sensing of stream flow rates - Correlation of meander and discharge spectra

    NASA Technical Reports Server (NTRS)

    Lingenfelter, R. E.; Schubert, G.

    1973-01-01

    Results of a study of river meander patterns and discharges, in which attempt was made to correlate the discharge spectrum of a river with the river meander power spectrum determined from aerial and satellite imagery. Some significant characteristics of both the discharge and the meander spectra have been discovered. Discharge frequency spectra based on long-term records of daily streamflow are found to have an inverse power-law dependence on discharge. This is shown to reflect the short-term decay of individual floods which are found to have an inverse power-law dependence on time. Meander power spectra for a number of river reaches, digitized from aerial photography, also show significant structure, the power spectral density having an inverse power-law dependence on wave number over one or more portions of the spectrum with breaks in the spectra at characteristic wave numbers. A number of examples of typical discharge and meander spectra are shown.

  16. Analysis of Doppler flow spectra of the superior vena cava in a canine model of acute thromboembolic pulmonary hypertension.

    PubMed

    Sun, Dan Dan; Chen, Hong Mao; Duan, Yun You; Yuan, Li Jun; Shang, Fu Jun; Liang, Ning Nan; Cao, Wei

    2011-10-01

    We aimed to establish a canine model of acute thromboembolic pulmonary hypertension (ATEPH) and to explore the feasibility of diagnosing pulmonary hypertension (PH) through the Doppler flow spectra of the superior vena cava (SVC). A canine model of ATEPH was developed by infusing thrombus into the right femoral vein. The pulmonary arterial pressure was simultaneously measured via a right heart catheter with the guidance of ultrasound. The maximum systolic peak flow velocity (SPV), ventricular reverse peak flow velocity (VRPV), diastolic peak flow velocity (DPV), and atrial reverse peak flow velocity (ARPV) of the SVC were measured by transthoracic echocardiography. ATEPH was successfully established in 24 dogs (88.9%) with the pulmonary arterial systolic pressure (PASP) greater than 30 mmHg. ARPV increased significantly with the increase of PASP, and was positively correlated with PASP (P<0.001). The ARPV/SPV larger than 0.8 could be better adopted to identify all the subjects with PH in this study. The Doppler flow spectra of the SVC could be employed to assess the severity of ATEPH.  PMID:21916968

  17. Elliptic Functions and Integrals with Real Modulus in Fluid Mechanics

    NASA Technical Reports Server (NTRS)

    Legendre, Robert

    1958-01-01

    Advantage of the elliptic functions and of the more general functions of Schwarz for fluid mechanics. Flows outside and inside polygons. Application to the calculation of an elbow diffuser for a wind tunnel. Properties of the elliptic integrals of the first kind and of the elliptic functions. Properties of the theta functions and decomposition of the elliptic functions into products of theta functions. Properties of the zeta functions. Decomposition of the elliptic functions into sums of zeta functions and calculations of the elliptic integrals. Applications to the calculation of wing profiles, of compressor profiles, and to the study of the vibrations of airplane wings and of compressor vanes. The manuscript of the present paper was checked by Mr. Eichelbrenner who corrected several imperfections and suggested numerous improvements to make reading of the paper easier. However, the limited subject does not permit filling in more than an incomplete knowledge of the properties of analytic functions.

  18. Real-time detection and characterization of individual flowing airborne biological particles: fluorescence spectra and elastic scattering measurements

    NASA Astrophysics Data System (ADS)

    Pan, Yongle; Holler, Stephen; Chang, Richard K.; Hill, Steven C.; Pinnick, Ronald G.; Niles, Stanley; Bottiger, Jerold R.; Bronk, Burt V.

    1999-11-01

    Real-time methods which is reagentless and could detect and partially characterize bioaerosols are of current interest. We present a technique for real-time measurement of UV-excited fluorescence spectra and two-dimensional angular optical scattering (TAOS) from individual flowing biological aerosol particles. The fluorescence spectra have been observed from more than 20 samples including Bacillus subtilis, Escherichia coli, Erwinia herbicola, allergens, dust, and smoke. The S/N and resolution of the spectra are sufficient for observing small lineshape differences among the same type of bioaerosol prepared under different conditions. The additional information from TAOS regarding particle size, shape, and granularity has the potential of aiding in distinguishing bacterial aerosols from other aerosols, such as diesel and cigarette smoke.

  19. The elliptic anomaly

    NASA Technical Reports Server (NTRS)

    Janin, G.; Bond, V. R.

    1980-01-01

    An independent variable different from the time for elliptic orbit integration is used. Such a time transformation provides an analytical step-size regulation along the orbit. An intermediate anomaly (an anomaly intermediate between the eccentric and the true anomaly) is suggested for optimum performances. A particular case of an intermediate anomaly (the elliptic anomaly) is defined, and its relation with the other anomalies is developed.

  20. Global variational approach to elliptic transport barriers in three dimensions

    NASA Astrophysics Data System (ADS)

    Oettinger, David; Blazevski, Daniel; Haller, George

    2016-03-01

    We introduce an approach to identify elliptic transport barriers in three-dimensional, time-aperiodic flows. Obtained as Lagrangian Coherent Structures (LCSs), the barriers are tubular non-filamenting surfaces that form and bound coherent material vortices. This extends a previous theory of elliptic LCSs as uniformly stretching material surfaces from two-dimensional to three-dimensional flows. Specifically, we obtain explicit expressions for the normals of pointwise (near-) uniformly stretching material surfaces over a finite time interval. We use this approach to visualize elliptic LCSs in steady and time-aperiodic ABC-type flows.

  1. Global variational approach to elliptic transport barriers in three dimensions.

    PubMed

    Oettinger, David; Blazevski, Daniel; Haller, George

    2016-03-01

    We introduce an approach to identify elliptic transport barriers in three-dimensional, time-aperiodic flows. Obtained as Lagrangian Coherent Structures (LCSs), the barriers are tubular non-filamenting surfaces that form and bound coherent material vortices. This extends a previous theory of elliptic LCSs as uniformly stretching material surfaces from two-dimensional to three-dimensional flows. Specifically, we obtain explicit expressions for the normals of pointwise (near-) uniformly stretching material surfaces over a finite time interval. We use this approach to visualize elliptic LCSs in steady and time-aperiodic ABC-type flows. PMID:27036192

  2. Young Elliptical Galaxies

    NASA Astrophysics Data System (ADS)

    Kim, Dong-Woo

    2005-10-01

    We propose deep XMM-Newton observations of two young, post-merger elliptical galaxies, NGC 3377 and NGC 5018. Because their X-ray to optical luminosity ratios are the lowest among ellipticals and their stellar populations are significantly metal-enriched, they are the best candidates to address two biggest unsolved problems of the X-ray study of elliptical galaxies: large L_X/L_B scatter and ISM Fe discrepancy. Our XMM-Newton data, in conjunction with the existing Chandra data will allow us to accurately determine Fe and alpha-elements abundances. We will then address the origin of the large L_X/L_B scatter in terms of ISM removal mechanisms by merger-induced galactic winds.

  3. Deconvolution of Stark broadened spectra for multi-point density measurements in a flow Z-pinch

    SciTech Connect

    Vogman, G. V.; Shumlak, U.

    2011-10-13

    Stark broadened emission spectra, once separated from other broadening effects, provide a convenient non-perturbing means of making plasma density measurements. A deconvolution technique has been developed to measure plasma densities in the ZaP flow Z-pinch experiment. The ZaP experiment uses sheared flow to mitigate MHD instabilities. The pinches exhibit Stark broadened emission spectra, which are captured at 20 locations using a multi-chord spectroscopic system. Spectra that are time- and chord-integrated are well approximated by a Voigt function. The proposed method simultaneously resolves plasma electron density and ion temperature by deconvolving the spectral Voigt profile into constituent functions: a Gaussian function associated with instrument effects and Doppler broadening by temperature; and a Lorentzian function associated with Stark broadening by electron density. The method uses analytic Fourier transforms of the constituent functions to fit the Voigt profile in the Fourier domain. The method is discussed and compared to a basic least-squares fit. The Fourier transform fitting routine requires fewer fitting parameters and shows promise in being less susceptible to instrumental noise and to contamination from neighboring spectral lines. The method is evaluated and tested using simulated lines and is applied to experimental data for the 229.69 nm C III line from multiple chords to determine plasma density and temperature across the diameter of the pinch. As a result, these measurements are used to gain a better understanding of Z-pinch equilibria.

  4. Deconvolution of Stark broadened spectra for multi-point density measurements in a flow Z-pinch

    DOE PAGESBeta

    Vogman, G. V.; Shumlak, U.

    2011-10-13

    Stark broadened emission spectra, once separated from other broadening effects, provide a convenient non-perturbing means of making plasma density measurements. A deconvolution technique has been developed to measure plasma densities in the ZaP flow Z-pinch experiment. The ZaP experiment uses sheared flow to mitigate MHD instabilities. The pinches exhibit Stark broadened emission spectra, which are captured at 20 locations using a multi-chord spectroscopic system. Spectra that are time- and chord-integrated are well approximated by a Voigt function. The proposed method simultaneously resolves plasma electron density and ion temperature by deconvolving the spectral Voigt profile into constituent functions: a Gaussian functionmore » associated with instrument effects and Doppler broadening by temperature; and a Lorentzian function associated with Stark broadening by electron density. The method uses analytic Fourier transforms of the constituent functions to fit the Voigt profile in the Fourier domain. The method is discussed and compared to a basic least-squares fit. The Fourier transform fitting routine requires fewer fitting parameters and shows promise in being less susceptible to instrumental noise and to contamination from neighboring spectral lines. The method is evaluated and tested using simulated lines and is applied to experimental data for the 229.69 nm C III line from multiple chords to determine plasma density and temperature across the diameter of the pinch. As a result, these measurements are used to gain a better understanding of Z-pinch equilibria.« less

  5. Multilevel filtering elliptic preconditioners

    NASA Technical Reports Server (NTRS)

    Kuo, C. C. Jay; Chan, Tony F.; Tong, Charles

    1989-01-01

    A class of preconditioners is presented for elliptic problems built on ideas borrowed from the digital filtering theory and implemented on a multilevel grid structure. They are designed to be both rapidly convergent and highly parallelizable. The digital filtering viewpoint allows the use of filter design techniques for constructing elliptic preconditioners and also provides an alternative framework for understanding several other recently proposed multilevel preconditioners. Numerical results are presented to assess the convergence behavior of the new methods and to compare them with other preconditioners of multilevel type, including the usual multigrid method as preconditioner, the hierarchical basis method and a recent method proposed by Bramble-Pasciak-Xu.

  6. Forward-backward elliptic anisotropy correlations in parton cascades

    NASA Astrophysics Data System (ADS)

    Han, L. X.; Ma, G. L.; Ma, Y. G.; Cai, X. Z.; Chen, J. H.; Zhang, S.; Zhong, C.

    2011-04-01

    A potential experimental probe, the forward-backward elliptic anisotropy correlation (CFB), has been proposed by Liao and Koch to distinguish the jet and true elliptic flow contribution to the measured elliptic flow (v2) in relativistic heavy-ion collisions. The jet and flow fluctuation contribution to elliptic flow is investigated within the framework of a multiphase transport model using the CFB probe. We find that the CFB correlation is remarkably different from, and about two times that, proposed by Liao and Koch. It originates from the correlation between fluctuation of forward and that of backward elliptic flow at a low transverse momentum, which is mainly caused by the initial correlation between fluctuation of forward and that of backward eccentricity. This results in an amendment of the CFB by a term related to the correlation between fluctuation of forward and that of backward elliptic flow. Our results suggest that a suitable rapidity gap for CFB correlation studies is about ±3.5.

  7. INFRARED SPECTROSCOPY OF NEARBY RADIO ACTIVE ELLIPTICAL GALAXIES

    SciTech Connect

    Mould, Jeremy; Reynolds, Tristan; Readhead, Tony; Matthews, Keith; Floyd, David; Brown, Michael; Jannuzi, Buell; Atlee, David; Cotter, Garret; Ferrarese, Laura

    2012-11-15

    In preparation for a study of their circumnuclear gas we have surveyed 60% of a complete sample of elliptical galaxies within 75 Mpc that are radio sources. Some 20% of our nuclear spectra have infrared emission lines, mostly Paschen lines, Brackett {gamma}, and [Fe II]. We consider the influence of radio power and black hole mass in relation to the spectra. Access to the spectra is provided here as a community resource.

  8. Elliptic flow at high transverse momentum in Pb-Pb collisions at \\sqrt{s_{NN}} = 2.76 TeV with the ALICE experiment

    NASA Astrophysics Data System (ADS)

    Dobrin, A.; ALICE Collaboration

    2011-12-01

    An observable that can be used to better constrain the mechanism responsible for parton energy loss is the elliptic azimuthal event anisotropy, v2. We report on measurements of v2 for inclusive and identified charged particles in Pb-Pb collisions at \\sqrt{s_{NN}} = 2.76 TeV recorded by the ALICE experiment at the LHC. v2 is presented for a wide range of particle transverse momentum up to pT = 20 GeV/c within the pseudo-rapidity region |η| < 0.8. The particle v2 is finite, positive and approximately constant for pT > 8 GeV/c. The proton v2 is higher than that of the pion up to about pT = 8 GeV/c. The results are compared to the measurements at lower energy reported by RHIC experiments.

  9. Direct control of the grid point distribution in meshes generated by elliptic equations. [for solution of Navier-Stokes nozzle flow

    NASA Technical Reports Server (NTRS)

    Middlecoff, J. F.; Thomas, P. D.

    1979-01-01

    The generation of computational grids suitable for obtaining accurate numerical solutions to the three-dimensional Navier-Stokes equations is the subject of intensive research. For a wide class of nozzle configurations, a three-dimensional grid can be constructed by a sequence of two-dimensional grids in successive cross-sectional planes. The present paper is concerned with numerical generation of two-dimensional grids. An effective method of interior grid control is presented based on a modified elliptic system containing free parameters. For a simply connected region, the free parameters are computed from the Dirichlet boundary values. The resulting interior grid point distribution is controlled entirely by a priori selection of the grid point distribution along the boundaries of the section.

  10. Analysis of surface pressure distributions on two elliptic missile configurations

    NASA Technical Reports Server (NTRS)

    Allen, J. M.; Pittman, J. L.

    1983-01-01

    The state-of-the-art methods for predicting missile aerodynamic characteristics do not accurately predict the loads of missile configurations with bodies of elliptic cross section. An investigation of this problem found significant nonlinear flow disturbance on the windward surface of a 3:1 elliptic body at Mach 2.50 in addition to the nonlinear vortical flows which develop on the leeside. A nonlinear full-potential flow method (NCOREL) was found to provide extremely accurate pressure estimates for attached-flow conditions and the vortex prediction method contained in the state-of-the-art method (NOSEVTX) was shown to accurately calculate body vortices and leeside pressures.

  11. Elliptic scattering equations

    NASA Astrophysics Data System (ADS)

    Cardona, Carlos; Gomez, Humberto

    2016-06-01

    Recently the CHY approach has been extended to one loop level using elliptic functions and modular forms over a Jacobian variety. Due to the difficulty in manipulating these kind of functions, we propose an alternative prescription that is totally algebraic. This new proposal is based on an elliptic algebraic curve embedded in a mathbb{C}{P}^2 space. We show that for the simplest integrand, namely the n - gon, our proposal indeed reproduces the expected result. By using the recently formulated Λ-algorithm, we found a novel recurrence relation expansion in terms of tree level off-shell amplitudes. Our results connect nicely with recent results on the one-loop formulation of the scattering equations. In addition, this new proposal can be easily stretched out to hyperelliptic curves in order to compute higher genus.

  12. Vibration and Noise Characteristics of Elliptical Gears due to Non-Uniform Rotation

    NASA Astrophysics Data System (ADS)

    Liu, Xing; Nagamura, Kazuteru; Ikejo, Kiyotaka

    Elliptical gear is a typical non-circular gear, which transmits a variable-ratio rotation and power simultaneously. Due to the non-uniform rotation, the vibration and noise of elliptical gears demonstrate particular characteristics which should be paid attention to in practical application. In this paper, two elliptical gears, which are a single elliptical gear and a double elliptical gear, have been investigated to analyze the vibration and noise characteristics of elliptical gears. The corresponding circular gears for comparison are also investigated. General factors including the torque, the rotation speed, the gear vibration acceleration and the gear noise of the four test gears are measured by running test. The root mean square of the Circumferential Vibration Acceleration (CVA) and the sound pressure level of the noise of elliptical gears are obtained from the measured results and compared with those of circular gears to clarify the vibration and noise characteristics of elliptical gears. Furthermore, the frequency analysis of the CVA of elliptical gears is conducted by Fast Fourier Transform Algorithm (FFT) and compared with that of circular gears. The main vibration component of elliptical gear is uncovered according to the obtained frequency spectra. In addition, the Critical Rotation Speeds of Tooth Separation (CRSTS) of elliptical gear is obtained and its relation with load torque is unveiled.

  13. Circular and Elliptic Submerged Impinging Water Jets

    NASA Astrophysics Data System (ADS)

    Claudey, Eric; Benedicto, Olivier; Ravier, Emmanuel; Gutmark, Ephraim

    1999-11-01

    Experiments and CFD have been performed to study circular and elliptic jets in a submerged water jet facility. The tests included discharge coefficient measurement to evaluate pressure losses encountered in noncircular nozzles compared to circular ones. Three-dimensional pressure mappings on the impingement surface and PIV measurement of the jet mean and turbulent velocity have been performed at different compound impingement angles relative to the impingement surface and at different stand-off distances. The objective was to investigate the effect of the non-circular geometry on the flow field and on the impact region. The tests were performed in a close loop system in which the water was pumped through the nozzles into a clear Plexiglas tank. The Reynolds numbers were typically in the range of 250000. Discharge coefficients of the elliptic nozzle was somewhat lower than that of the circular jet but spreading rate and turbulence level were higher. Pressure mapping showed that the nozzle exit geometry had an effect on the pressure distribution in the impact region and that high-pressure zones were generated at specific impact points. PIV measurements showed that for a same total exit area, the elliptic jets affected a surface area that is 8the equivalent circular. The turbulence level in the elliptic jet tripled due to the nozzle design. Results of the CFD model were in good agreement with the experimental data.

  14. STELLAR POPULATIONS OF ELLIPTICAL GALAXIES IN THE LOCAL UNIVERSE

    SciTech Connect

    Zhu Guangtun; Blanton, Michael R.; Moustakas, John E-mail: michael.blanton@nyu.ed

    2010-10-10

    We study the stellar populations of 1923 elliptical galaxies at z < 0.05 selected from the Sloan Digital Sky Survey as a function of velocity dispersion, {sigma}, and environment. Our sample constitutes among the largest high-fidelity samples of elliptical galaxies with uniform imaging and optical spectroscopy assembled to date. Confirming previous studies, we find that elliptical galaxies dominate at high luminosities ({approx}>L*), and that the highest-{sigma} ellipticals favor high-density environments. We construct average, high signal-to-noise spectra in bins of {sigma} and environment and find the following: (1) lower-{sigma} galaxies have a bluer optical continuum and stronger (but still weak) emission lines; (2) at fixed {sigma}, field ellipticals have a slightly bluer stellar continuum, especially at wavelengths {approx}<4000 A, and have stronger (but still weak) emission lines compared with their group counterparts, although this environmental dependence is strongest for low-{sigma} ellipticals and the highest-{sigma} ellipticals are much less affected. Based on Lick indices measured from both the individual and average spectra, we find that (1) at a given {sigma}, elliptical galaxies in groups have systematically weaker Balmer absorption than their field counterparts, although this environmental dependence is most pronounced at low {sigma}; (2) there is no clear environmental dependence of (Fe), while the {alpha}-element absorption indices such as Mg b are only slightly stronger in galaxies belonging to rich groups. An analysis based on simple stellar populations (SSPs) reveals that more massive elliptical galaxies are older, more metal-rich, and more strongly {alpha}-enhanced. We also find that (1) the SSP-equivalent ages of galaxies in rich groups are, on average, {approx}1 Gyr older than in the field, although once again this effect is strongest at low {sigma}; (2) galaxies in rich groups have slightly lower [Fe/H] and are marginally more strongly

  15. Spectra and radial flow in relativistic heavy ion collisions with Tsallis statistics in a blast-wave description

    SciTech Connect

    Tang Zebo; Xu Yichun; Ruan Lijuan; Buren, Gene van; Xu Zhangbu; Wang Fuqiang

    2009-05-15

    We have implemented the Tsallis statistics in a Blast-Wave model (TBW) and applied it to midrapidity transverse-momentum spectra of identified particles measured at BNL Relativistic Heavy Ion Collider (RHIC). This new TBW function fits the RHIC data very well for p{sub T}<3 GeV/c. We observed that the collective flow velocity starts from zero in p+p and peripheral Au+Au collisions and grows to 0.470{+-}0.009c in central Au+Au collisions. The resulting (q-1) parameter, which characterizes the degree of nonequilibrium in a system, indicates an evolution from a highly nonequilibrated system in p+p collisions toward an almost thermalized system in central Au+Au collisions. The temperature and collective velocity are well described by a quadratic dependence on (q-1). Two sets of parameters in our TBW are required to describe the meson and baryon groups separately in p+p collisions while one set appears to fit all spectra in central Au+Au collisions.

  16. Centrality and Transverse Momentum Dependence of Elliptic Flow of Multistrange Hadrons and ϕ Meson in Au+Au Collisions at √[sNN]=200  GeV.

    PubMed

    Adamczyk, L; Adkins, J K; Agakishiev, G; Aggarwal, M M; Ahammed, Z; Alekseev, I; Aparin, A; Arkhipkin, D; Aschenauer, E C; Averichev, G S; Bairathi, V; Banerjee, A; Bellwied, R; Bhasin, A; Bhati, A K; Bhattarai, P; Bielcik, J; Bielcikova, J; Bland, L C; Bordyuzhin, I G; Bouchet, J; Brandin, A V; Bunzarov, I; Butterworth, J; Caines, H; Calderón de la Barca Sánchez, M; Campbell, J M; Cebra, D; Cervantes, M C; Chakaberia, I; Chaloupka, P; Chang, Z; Chattopadhyay, S; Chen, J H; Chen, X; Cheng, J; Cherney, M; Christie, W; Contin, G; Crawford, H J; Das, S; De Silva, L C; Debbe, R R; Dedovich, T G; Deng, J; Derevschikov, A A; di Ruzza, B; Didenko, L; Dilks, C; Dong, X; Drachenberg, J L; Draper, J E; Du, C M; Dunkelberger, L E; Dunlop, J C; Efimov, L G; Engelage, J; Eppley, G; Esha, R; Evdokimov, O; Eyser, O; Fatemi, R; Fazio, S; Federic, P; Fedorisin, J; Feng, Z; Filip, P; Fisyak, Y; Flores, C E; Fulek, L; Gagliardi, C A; Garand, D; Geurts, F; Gibson, A; Girard, M; Greiner, L; Grosnick, D; Gunarathne, D S; Guo, Y; Gupta, S; Gupta, A; Guryn, W; Hamad, A; Hamed, A; Haque, R; Harris, J W; He, L; Heppelmann, S; Heppelmann, S; Hirsch, A; Hoffmann, G W; Hofman, D J; Horvat, S; Huang, X; Huang, B; Huang, H Z; Huck, P; Humanic, T J; Igo, G; Jacobs, W W; Jang, H; Jiang, K; Judd, E G; Kabana, S; Kalinkin, D; Kang, K; Kauder, K; Ke, H W; Keane, D; Kechechyan, A; Khan, Z H; Kikoła, D P; Kisel, I; Kisiel, A; Kochenda, L; Koetke, D D; Kollegger, T; Kosarzewski, L K; Kraishan, A F; Kravtsov, P; Krueger, K; Kulakov, I; Kumar, L; Kycia, R A; Lamont, M A C; Landgraf, J M; Landry, K D; Lauret, J; Lebedev, A; Lednicky, R; Lee, J H; Li, Z M; Li, W; Li, X; Li, X; Li, C; Li, Y; Lisa, M A; Liu, F; Ljubicic, T; Llope, W J; Lomnitz, M; Longacre, R S; Luo, X; Ma, Y G; Ma, G L; Ma, L; Ma, R; Magdy, N; Majka, R; Manion, A; Margetis, S; Markert, C; Masui, H; Matis, H S; McDonald, D; Meehan, K; Minaev, N G; Mioduszewski, S; Mishra, D; Mohanty, B; Mondal, M M; Morozov, D A; Mustafa, M K; Nandi, B K; Nasim, Md; Nayak, T K; Nigmatkulov, G; Nogach, L V; Noh, S Y; Novak, J; Nurushev, S B; Odyniec, G; Ogawa, A; Oh, K; Okorokov, V; Olvitt, D; Page, B S; Pak, R; Pan, Y X; Pandit, Y; Panebratsev, Y; Pawlik, B; Pei, H; Perkins, C; Peterson, A; Pile, P; Planinic, M; Pluta, J; Poljak, N; Poniatowska, K; Porter, J; Posik, M; Poskanzer, A M; Putschke, J; Qiu, H; Quintero, A; Ramachandran, S; Raniwala, R; Raniwala, S; Ray, R L; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Roy, A; Ruan, L; Rusnak, J; Rusnakova, O; Sahoo, N R; Sahu, P K; Sakrejda, I; Salur, S; Sandweiss, J; Sarkar, A; Schambach, J; Scharenberg, R P; Schmah, A M; Schmidke, W B; Schmitz, N; Seger, J; Seyboth, P; Shah, N; Shahaliev, E; Shanmuganathan, P V; Shao, M; Sharma, B; Sharma, M K; Shen, W Q; Shi, S S; Shou, Q Y; Sichtermann, E P; Sikora, R; Simko, M; Singha, S; Skoby, M J; Smirnov, D; Smirnov, N; Song, L; Sorensen, P; Spinka, H M; Srivastava, B; Stanislaus, T D S; Stepanov, M; Stock, R; Strikhanov, M; Stringfellow, B; Sumbera, M; Summa, B; Sun, X; Sun, X M; Sun, Y; Sun, Z; Surrow, B; Svirida, N; Szelezniak, M A; Tang, A H; Tang, Z; Tarnowsky, T; Tawfik, A; Thomas, J H; Timmins, A R; Tlusty, D; Tokarev, M; Trentalange, S; Tribble, R E; Tribedy, P; Tripathy, S K; Trzeciak, B A; Tsai, O D; Ullrich, T; Underwood, D G; Upsal, I; Van Buren, G; van Nieuwenhuizen, G; Vandenbroucke, M; Varma, R; Vasiliev, A N; Vertesi, R; Videbæk, F; Viyogi, Y P; Vokal, S; Voloshin, S A; Vossen, A; Wang, Y; Wang, G; Wang, J S; Wang, H; Wang, Y; Wang, F; Webb, J C; Webb, G; Wen, L; Westfall, G D; Wieman, H; Wissink, S W; Witt, R; Wu, Y F; Wu, Y; Xiao, Z G; Xie, W; Xin, K; Xu, N; Xu, Z; Xu, Q H; Xu, Y F; Xu, H; Yang, Q; Yang, Y; Yang, Y; Yang, S; Yang, C; Ye, Z; Yepes, P; Yi, L; Yip, K; Yoo, I-K; Yu, N; Zbroszczyk, H; Zha, W; Zhang, Z; Zhang, Y; Zhang, J B; Zhang, J; Zhang, S; Zhang, J; Zhang, X P; Zhao, J; Zhong, C; Zhou, L; Zhu, X; Zoulkarneeva, Y; Zyzak, M

    2016-02-12

    We present high precision measurements of elliptic flow near midrapidity (|y|<1.0) for multistrange hadrons and ϕ meson as a function of centrality and transverse momentum in Au+Au collisions at center of mass energy √[sNN]=200  GeV. We observe that the transverse momentum dependence of ϕ and Ω v2 is similar to that of π and p, respectively, which may indicate that the heavier strange quark flows as strongly as the lighter up and down quarks. This observation constitutes a clear piece of evidence for the development of partonic collectivity in heavy-ion collisions at the top RHIC energy. Number of constituent quark scaling is found to hold within statistical uncertainty for both 0%-30% and 30%-80% collision centrality. There is an indication of the breakdown of previously observed mass ordering between ϕ and proton v2 at low transverse momentum in the 0%-30% centrality range, possibly indicating late hadronic interactions affecting the proton v2. PMID:26918982

  17. Measurements of the Temperature of Subsonic CO{sub 2} Induction Plasma Flows by Analyzing Their Emission Spectra

    SciTech Connect

    Bykova, N.G.; Kuznetsova, L.A.

    2004-11-15

    Results are presented from measurements of the temperature characteristics of subsonic CO{sub 2} plasma flows generated by a 100-kW induction plasmatron at the Institute for Problems of Mechanics, Russian Academy of Sciences. The atomic excitation temperature T{sub a} and the population temperature T{sub e} of the electronic states of C{sub 2} molecules (both averaged over the jet diameter) were measured from the absolute intensities of the atomic spectral lines and the spectrum of C{sub 2} molecules in different generation regimes at gas pressures of 25-140 hPa and anode supply powers of 29-72 kW. The longitudinal and radial profiles of the temperatures were determined for some of these regimes and compared to those obtained from numerical calculations of equilibrium induction plasma flows in the discharge channel. For some generation regimes, the dependences of the averaged (over the line of sight) rotational and vibrational temperatures (T{sub r} and T{sub v} ) on the discharge parameters, as well as the radial profiles of these temperatures, were determined from the best fit of the measured and calculated spectra of C{sub 2} molecules (Swan bands). The self-absorption of molecular emission was observed at sufficiently high temperatures and gas pressures, and its influence on the measured values of the molecular temperatures T{sub e} , T{sub v} , and T{sub r} was examined.

  18. The Invertible Double of Elliptic Operators

    NASA Astrophysics Data System (ADS)

    Booss-Bavnbek, Bernhelm; Lesch, Matthias

    2009-02-01

    First, we review the Dirac operator folklore about basic analytic and geometrical properties of operators of Dirac type on compact manifolds with smooth boundary and on closed partitioned manifolds and show how these properties depend on the construction of a canonical invertible double and are related to the concept of the Calderón projection. Then we summarize a recent construction of a canonical invertible double for general first order elliptic differential operators over smooth compact manifolds with boundary. We derive a natural formula for the Calderón projection which yields a generalization of the famous Cobordism Theorem. We provide a list of assumptions to obtain a continuous variation of the Calderón projection under smooth variation of the coefficients. That yields various new spectral flow theorems. Finally, we sketch a research program for confining, respectively closing, the last remaining gaps between the geometric Dirac operator type situation and the general linear elliptic case.

  19. Blue ellipticals in compact groups

    NASA Technical Reports Server (NTRS)

    Zepf, Stephen E.; Whitmore, Bradley C.

    1990-01-01

    By studying galaxies in compact groups, the authors examine the hypothesis that mergers of spiral galaxies make elliptical galaxies. The authors combine dynamical models of the merger-rich compact group environment with stellar evolution models and predict that roughly 15 percent of compact group ellipticals should be 0.15 mag bluer in B - R color than normal ellipticals. The published colors of these galaxies suggest the existence of this predicted blue population, but a normal distribution with large random errors can not be ruled out based on these data alone. However, the authors have new ultraviolet blue visual data which confirm the blue color of the two ellipticals with blue B - R colors for which they have their own colors. This confirmation of a population of blue ellipticals indicates that interactions are occurring in compact groups, but a blue color in one index alone does not require that these ellipticals are recent products of the merger of two spirals. The authors demonstrate how optical spectroscopy in the blue may distinguish between a true spiral + spiral merger and the swallowing of a gas-rich system by an already formed elliptical. The authors also show that the sum of the luminosity of the galaxies in each group is consistent with the hypothesis that the final stage in the evolution of compact group is an elliptical galaxy.

  20. Elliptical Orbit Performance Computer Program

    NASA Technical Reports Server (NTRS)

    Myler, T.

    1984-01-01

    Elliptical Orbit Performance (ELOPE) computer program for analyzing orbital performance of space boosters uses orbit insertion data obtained from trajectory simulation to generate parametric data on apogee and perigee altitudes as function of payload data. Data used to generate presentation plots that display elliptical orbit performance capability of space booster.

  1. An explanation of the elliptic flow difference between proton and anti-proton from the UrQMD model with hadron potentials

    NASA Astrophysics Data System (ADS)

    Li, QingFeng; Wang, YongJia; Wang, XiaoBao; Shen, CaiWan

    2016-03-01

    The time evolution of both proton and anti-proton v 2 flows from Au+Au collisions at √{{S_{NN}}} = 7.7 GeV are examined by using both pure cascade and mean-field potential versions of the UrQMD model. Due to a stronger repulsion at the early stage introduced by the repulsive potentials and hence much less annihilation probabilities, anti-protons are frozen out earlier with smaller v 2 values. Therefore, the experimental data of anti-proton v 2 as well as the flow difference between proton and anti-proton can be reasonably described with the potential version of UrQMD.

  2. Light (anti-)nuclei production and flow in relativistic heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Zhu, Lilin; Ko, Che Ming; Yin, Xuejiao

    2015-12-01

    Using the coalescence model based on the phase-space distributions of protons, neutrons, Λ s , and their antiparticles from a multiphase transport (AMPT) model, we study the production of light nuclei (H, H, He, H) and their antinuclei in Pb+Pb collisions at √{sN N}=2.76 TeV. The resulting transverse momentum spectra, elliptic flows, and coalescence parameters for these nuclei are presented and compared with available experimental data. We also show the constituent number scaled elliptic flows of these nuclei and discuss its implications.

  3. Elliptic and hexadecapole flow of charged hadrons in viscous hydrodynamics with Glauber and color glass condensate initial conditions for Pb-Pb collision at \\sqrt{s_{NN}} = 2.76 TeV

    NASA Astrophysics Data System (ADS)

    Roy, Victor; Mohanty, Bedangadas; Chaudhuri, A. K.

    2013-06-01

    The experimentally measured elliptic (v2) and hexadecapole (v4) flow of charged particles as a function of transverse momentum (pT) at midrapidity in Pb-Pb collisions at \\sqrt{s_{{N}N}} = 2.76 TeV is compared with the relativistic viscous hydrodynamic model simulations. The simulations are carried out for two different initial energy density profiles obtained from (i) the Glauber model, and (ii) the color glass condensate (CGC) model. A comparison to experimental data for 10-20% to 40-50% centrality shows that a centrality dependent shear viscosity to entropy density (η/s) ratio with values ranging between 0.0 to 0.12 is needed to explain the v2 data for simulations with the Glauber based initial condition, whereas for the CGC based initial conditions a slightly higher value of η/s is preferred, around 0.08 to 0.16. From the comparison of the v4 simulated results to the corresponding experimental measurements we observe that for the centralities 20-30% to 40-50% the η/s values lie between 0.0 to 0.12 for both the initial conditions studied. The η/s values obtained from our studies for Pb-Pb collisions at \\sqrt{s_{{N}N}} = 2.76 TeV are compared to other studies which use both transport and hydrodynamic approaches.

  4. Elliptic flow of muons from heavy-flavour hadron decays at forward rapidity in Pb-Pb collisions at √{sNN} = 2.76 TeV

    NASA Astrophysics Data System (ADS)

    Adam, J.; Adamová, D.; Aggarwal, M. M.; Aglieri Rinella, G.; Agnello, M.; Agrawal, N.; Ahammed, Z.; Ahn, S. U.; Aiola, S.; Akindinov, A.; Alam, S. N.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Alfaro Molina, R.; Alici, A.; Alkin, A.; Almaraz, J. R. M.; Alme, J.; Alt, T.; Altinpinar, S.; Altsybeev, I.; Alves Garcia Prado, C.; Andrei, C.; Andronic, A.; Anguelov, V.; Anielski, J.; Antičić, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Arcelli, S.; Armesto, N.; Arnaldi, R.; Arsene, I. C.; Arslandok, M.; Audurier, B.; Augustinus, A.; Averbeck, R.; Azmi, M. D.; Bach, M.; Badalà, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bala, R.; Baldisseri, A.; Baltasar Dos Santos Pedrosa, F.; Baral, R. C.; Barbano, A. M.; Barbera, R.; Barile, F.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartalini, P.; Barth, K.; Bartke, J.; Bartsch, E.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Batista Camejo, A.; Batyunya, B.; Batzing, P. C.; Bearden, I. G.; Beck, H.; Bedda, C.; Behera, N. K.; Belikov, I.; Bellini, F.; Bello Martinez, H.; Bellwied, R.; Belmont, R.; Belmont-Moreno, E.; Belyaev, V.; Bencedi, G.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Bertens, R. A.; Berzano, D.; Betev, L.; Bhasin, A.; Bhat, I. R.; Bhati, A. K.; Bhattacharjee, B.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Biswas, R.; Biswas, S.; Bjelogrlic, S.; Blair, J. T.; Blanco, F.; Blau, D.; Blume, C.; Bock, F.; Bogdanov, A.; Bøggild, H.; Boldizsár, L.; Bombara, M.; Book, J.; Borel, H.; Borissov, A.; Borri, M.; Bossú, F.; Botta, E.; Böttger, S.; Braun-Munzinger, P.; Bregant, M.; Breitner, T.; Broker, T. A.; Browning, T. A.; Broz, M.; Brucken, E. J.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buncic, P.; Busch, O.; Buthelezi, Z.; Butt, J. B.; Buxton, J. T.; Caffarri, D.; Cai, X.; Caines, H.; Calero Diaz, L.; Caliva, A.; Calvo Villar, E.; Camerini, P.; Carena, F.; Carena, W.; Carnesecchi, F.; Castillo Castellanos, J.; Castro, A. J.; Casula, E. A. R.; Cavicchioli, C.; Ceballos Sanchez, C.; Cepila, J.; Cerello, P.; Cerkala, J.; Chang, B.; Chapeland, S.; Chartier, M.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Chelnokov, V.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chibante Barroso, V.; Chinellato, D. D.; Chochula, P.; Choi, K.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Chunhui, Z.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Colocci, M.; Conesa Balbastre, G.; Conesa del Valle, Z.; Connors, M. E.; Contreras, J. G.; Cormier, T. M.; Corrales Morales, Y.; Cortés Maldonado, I.; Cortese, P.; Cosentino, M. R.; Costa, F.; Crochet, P.; Cruz Albino, R.; Cuautle, E.; Cunqueiro, L.; Dahms, T.; Dainese, A.; Danu, A.; Das, D.; Das, I.; Das, S.; Dash, A.; Dash, S.; De, S.; De Caro, A.; de Cataldo, G.; de Cuveland, J.; De Falco, A.; De Gruttola, D.; De Marco, N.; De Pasquale, S.; Deisting, A.; Deloff, A.; Dénes, E.; D'Erasmo, G.; Di Bari, D.; Di Mauro, A.; Di Nezza, P.; Diaz Corchero, M. A.; Dietel, T.; Dillenseger, P.; Divià, R.; Djuvsland, Ø.; Dobrin, A.; Dobrowolski, T.; Domenicis Gimenez, D.; Dönigus, B.; Dordic, O.; Drozhzhova, T.; Dubey, A. K.; Dubla, A.; Ducroux, L.; Dupieux, P.; Ehlers, R. J.; Elia, D.; Engel, H.; Epple, E.; Erazmus, B.; Erdemir, I.; Erhardt, F.; Espagnon, B.; Estienne, M.; Esumi, S.; Eum, J.; Evans, D.; Evdokimov, S.; Eyyubova, G.; Fabbietti, L.; Fabris, D.; Faivre, J.; Fantoni, A.; Fasel, M.; Feldkamp, L.; Felea, D.; Feliciello, A.; Feofilov, G.; Ferencei, J.; Fernández Téllez, A.; Ferreiro, E. G.; Ferretti, A.; Festanti, A.; Feuillard, V. J. G.; Figiel, J.; Figueredo, M. A. S.; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Fleck, M. G.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; Frankenfeld, U.; Fuchs, U.; Furget, C.; Furs, A.; Fusco Girard, M.; Gaardhøje, J. J.; Gagliardi, M.; Gago, A. M.; Gallio, M.; Gangadharan, D. R.; Ganoti, P.; Gao, C.; Garabatos, C.; Garcia-Solis, E.; Gargiulo, C.; Gasik, P.; Germain, M.; Gheata, A.; Gheata, M.; Ghosh, P.; Ghosh, S. K.; Gianotti, P.; Giubellino, P.; Giubilato, P.; Gladysz-Dziadus, E.; Glässel, P.; Goméz Coral, D. M.; Gomez Ramirez, A.; González-Zamora, P.; Gorbunov, S.; Görlich, L.; Gotovac, S.; Grabski, V.; Graczykowski, L. K.; Graham, K. L.; Grelli, A.; Grigoras, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Grosse-Oetringhaus, J. F.; Grossiord, J.-Y.; Grosso, R.; Guber, F.; Guernane, R.; Guerzoni, B.; Gulbrandsen, K.; Gulkanyan, H.; Gunji, T.; Gupta, A.; Gupta, R.; Haake, R.; Haaland, Ø.

    2016-02-01

    The elliptic flow, v2, of muons from heavy-flavour hadron decays at forward rapidity (2.5 < y < 4) is measured in Pb-Pb collisions at √{sNN} = 2.76 TeV with the ALICE detector at the LHC. The scalar product, two- and four-particle Q cumulants and Lee-Yang zeros methods are used. The dependence of the v2 of muons from heavy-flavour hadron decays on the collision centrality, in the range 0-40%, and on transverse momentum, pT, is studied in the interval 3

  5. Modulated Elliptical Slot

    NASA Technical Reports Server (NTRS)

    Abou-Khousa, M. A.

    2009-01-01

    A novel modulated slot design has been proposed and tested. The proposed slot is aimed to replace the inefficient small dipoles used in conventional MST-based imaging systems. The developed slot is very attractive as MST array element due to its small size and high efficiency/modulation depth. In fact, the developed slot has been successfully used to implement the first prototype of a microwave camera operating at 24 GHZ. It is also being used in the design of the second generation of the camera. Finally, the designed elliptical slot can be used as an electronically controlled waveguide iris for many other purposes (for instance in constructing waveguide reflective phase shifters and multiplexers/switches).

  6. Rotating convection in elliptical geometries

    NASA Astrophysics Data System (ADS)

    Evonuk, M.

    2014-12-01

    Tidal interactions between hot jupiter planets and their host stars are likely to result in non-spherical geometries. These elliptical instabilities may have interesting effects on interior fluid convective patterns, which in turn influence the nature of the magnetic dynamo within these planets. Simulations of thermal convection in the 2D rotating equatorial plane are conducted to determine to first order the effect of ellipticity on convection for varying density contrasts with differing convective vigor and rotation rate. This survey is conducted in two dimensions in order to simulate a broad range of ellipticities and to maximize the parameter space explored.

  7. Numerical calculations of flow fields

    NASA Technical Reports Server (NTRS)

    Anderson, D.; Vogel, J. M.

    1973-01-01

    Numerical calculations were made of flow fields generated by various aerodynamic configurations. Data cover flow fields generated by a finitely thick lifting three dimensional wing with subsonic tips moving at supersonic speeds, cross flow instability associated with lifting delta wing configurations such as space shuttles, and flow fields produced by a lifting elliptic cone. Finite difference techniques were used to determine elliptic cone flow.

  8. Bounding the elliptic Mahler measure

    NASA Astrophysics Data System (ADS)

    Pinner, Christopher

    1998-11-01

    We give a simple inequality relating the elliptic Mahler measure of a polynomial to the traditional Mahler measure (via the length of the polynomial). These bounds are essentially sharp. We also give the corresponding result for polynomials in several variables.

  9. Heavy-quark production and elliptic flow in Au + Au collisions at √{sN N}=62.4 GeV

    NASA Astrophysics Data System (ADS)

    Adare, A.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Akimoto, R.; Al-Ta'Ani, H.; Alexander, J.; Angerami, A.; Aoki, K.; Apadula, N.; Aramaki, Y.; Asano, H.; Aschenauer, E. C.; Atomssa, E. T.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Bai, M.; Bannier, B.; Barish, K. N.; Bassalleck, B.; Bathe, S.; Baublis, V.; Baumgart, S.; Bazilevsky, A.; Belmont, R.; Berdnikov, A.; Berdnikov, Y.; Bing, X.; Blau, D. S.; Bok, J. S.; Boyle, K.; Brooks, M. L.; Buesching, H.; Bumazhnov, V.; Butsyk, S.; Campbell, S.; Castera, P.; Chen, C.-H.; Chi, C. Y.; Chiu, M.; Choi, I. J.; Choi, J. B.; Choi, S.; Choudhury, R. K.; Christiansen, P.; Chujo, T.; Chvala, O.; Cianciolo, V.; Citron, Z.; Cole, B. A.; Connors, M.; Csanád, M.; Csörgő, T.; Dairaku, S.; Datta, A.; Daugherity, M. S.; David, G.; Denisov, A.; Deshpande, A.; Desmond, E. J.; Dharmawardane, K. V.; Dietzsch, O.; Ding, L.; Dion, A.; Donadelli, M.; Drapier, O.; Drees, A.; Drees, K. A.; Durham, J. M.; Durum, A.; D'Orazio, L.; Edwards, S.; Efremenko, Y. V.; Engelmore, T.; Enokizono, A.; Esumi, S.; Eyser, K. O.; Fadem, B.; Fields, D. E.; Finger, M.; Finger, M.; Fleuret, F.; Fokin, S. L.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fukao, Y.; Fusayasu, T.; Gainey, K.; Gal, C.; Garishvili, A.; Garishvili, I.; Glenn, A.; Gong, X.; Gonin, M.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grosse Perdekamp, M.; Gunji, T.; Guo, L.; Gustafsson, H.-Å.; Hachiya, T.; Haggerty, J. S.; Hahn, K. I.; Hamagaki, H.; Hanks, J.; Hashimoto, K.; Haslum, E.; Hayano, R.; He, X.; Hemmick, T. K.; Hester, T.; Hill, J. C.; Hollis, R. S.; Homma, K.; Hong, B.; Horaguchi, T.; Hori, Y.; Huang, S.; Ichihara, T.; Iinuma, H.; Ikeda, Y.; Imrek, J.; Inaba, M.; Iordanova, A.; Isenhower, D.; Issah, M.; Ivanishchev, D.; Jacak, B. V.; Javani, M.; Jia, J.; Jiang, X.; Johnson, B. M.; Joo, K. S.; Jouan, D.; Jumper, D. S.; Kamin, J.; Kaneti, S.; Kang, B. H.; Kang, J. H.; Kang, J. S.; Kapustinsky, J.; Karatsu, K.; Kasai, M.; Kawall, D.; Kazantsev, A. V.; Kempel, T.; Khanzadeev, A.; Kijima, K. M.; Kim, B. I.; Kim, C.; Kim, D. J.; Kim, E.-J.; Kim, H. J.; Kim, K.-B.; Kim, Y.-J.; Kim, Y. K.; Kinney, E.; Kiss, Á.; Kistenev, E.; Klatsky, J.; Kleinjan, D.; Kline, P.; Komatsu, Y.; Komkov, B.; Koster, J.; Kotchetkov, D.; Kotov, D.; Král, A.; Krizek, F.; Kunde, G. J.; Kurita, K.; Kurosawa, M.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lai, Y. S.; Lajoie, J. G.; Lebedev, A.; Lee, B.; Lee, D. M.; Lee, J.; Lee, K. B.; Lee, K. S.; Lee, S. H.; Lee, S. R.; Leitch, M. J.; Leite, M. A. L.; Leitgab, M.; Lewis, B.; Lim, S. H.; Linden Levy, L. A.; Liu, M. X.; Love, B.; Maguire, C. F.; Makdisi, Y. I.; Makek, M.; Manion, A.; Manko, V. I.; Mannel, E.; Masumoto, S.; McCumber, M.; McGaughey, P. L.; McGlinchey, D.; McKinney, C.; Mendoza, M.; Meredith, B.; Miake, Y.; Mibe, T.; Mignerey, A. C.; Milov, A.; Mishra, D. K.; Mitchell, J. T.; Miyachi, Y.; Miyasaka, S.; Mohanty, A. K.; Moon, H. J.; Morrison, D. P.; Motschwiller, S.; Moukhanova, T. V.; Murakami, T.; Murata, J.; Nagae, T.; Nagamiya, S.; Nagle, J. L.; Nagy, M. I.; Nakagawa, I.; Nakamiya, Y.; Nakamura, K. R.; Nakamura, T.; Nakano, K.; Nattrass, C.; Nederlof, A.; Nihashi, M.; Nouicer, R.; Novitzky, N.; Nyanin, A. S.; O'Brien, E.; Ogilvie, C. A.; Okada, K.; Oskarsson, A.; Ouchida, M.; Ozawa, K.; Pak, R.; Pantuev, V.; Papavassiliou, V.; Park, B. H.; Park, I. H.; Park, S. K.; Pate, S. F.; Patel, L.; Pei, H.; Peng, J.-C.; Pereira, H.; Peressounko, D. Yu.; Petti, R.; Pinkenburg, C.; Pisani, R. P.; Proissl, M.; Purschke, M. L.; Qu, H.; Rak, J.; Ravinovich, I.; Read, K. F.; Reynolds, D.; Riabov, V.; Riabov, Y.; Richardson, E.; Riveli, N.; Roach, D.; Roche, G.; Rolnick, S. D.; Rosati, M.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Samsonov, V.; Sano, M.; Sarsour, M.; Sawada, S.; Sedgwick, K.; Seidl, R.; Sen, A.; Seto, R.; Sharma, D.; Shein, I.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shoji, K.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Sim, K. S.; Singh, B. K.; Singh, C. P.; Singh, V.; Slunečka, M.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Soumya, M.; Sourikova, I. V.; Stankus, P. W.; Stenlund, E.; Stepanov, M.; Ster, A.; Stoll, S. P.; Sugitate, T.; Sukhanov, A.; Sun, J.; Sziklai, J.; Takagui, E. M.; Takahara, A.; Taketani, A.; Tanaka, Y.; Taneja, S.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tennant, E.; Themann, H.; Todoroki, T.; Tomášek, L.; Tomášek, M.; Torii, H.; Towell, R. S.; Tserruya, I.; Tsuchimoto, Y.; Tsuji, T.; Vale, C.; van Hecke, H. W.; Vargyas, M.; Vazquez-Zambrano, E.; Veicht, A.; Velkovska, J.; Vértesi, R.; Virius, M.; Vossen, A.; Vrba, V.; Vznuzdaev, E.; Wang, X. R.; Watanabe, D.; Watanabe, K.; Watanabe, Y.; Watanabe, Y. S.; Wei, F.; Wei, R.; Whitaker, S.; White, S. N.; Winter, D.; Wolin, S.; Woody, C. L.; Wysocki, M.; Yamaguchi, Y. L.; Yang, R.; Yanovich, A.; Ying, J.; Yokkaichi, S.; You, Z.; Younus, I.; Yushmanov, I. E.; Zajc, W. A.; Zelenski, A.; Phenix Collaboration

    2015-04-01

    We present measurements of electrons and positrons from the semileptonic decays of heavy-flavor hadrons at midrapidity (|y |< 0.35) in Au +Au collisions at √{sN N}=62.4 GeV. The data were collected in 2010 by the PHENIX experiment that included the new hadron-blind detector. The invariant yield of electrons from heavy-flavor decays is measured as a function of transverse momentum in the range 1 flow, and energy loss in medium. The v2 of electrons from heavy-flavor decays is nonzero when averaged between 1.3

  10. Heavy-quark production and elliptic flow in Au+Au collisions at √sNN=62.4 GeV

    SciTech Connect

    Adare, A.

    2015-04-28

    In this study, we present measurements of electrons and positrons from the semileptonic decays of heavy-flavor hadrons at midrapidity (|y|< 0.35) in Au+Au collisions at √sNN = 62.4 GeV. The data were collected in 2010 by the PHENIX experiment that included the new hadron-blind detector. The invariant yield of electrons from heavy-flavor decays is measured as a function of transverse momentum in the range 1 < peT < 5 GeV/c. The invariant yield per binary collision is slightly enhanced above the p+p reference in Au+Au 0%–20%, 20%–40%, and 40%–60% centralities at a comparable level. At this low beam energy this may be a result of the interplay between initial-state Cronin effects, final-state flow, and energy loss in medium. The v₂ of electrons from heavy-flavor decays is nonzero when averaged between 1.3 < peT < 2.5 GeV/c for 0%–40% centrality collisions at √sNN = 62.4 GeV. For 20%–40% centrality collisions, the v₂ at √sNN = 62.4 GeV is smaller than that for heavy-flavor decays at √sNN = 200 GeV. The v₂ of the electrons from heavy-flavor decay at the lower beam energy is also smaller than v₂ for pions. Both results indicate that the heavy-quarks interact with the medium formed in these collisions, but they may not be at the same level of thermalization with the medium as observed at √sNN = 200 GeV.

  11. Heavy-quark production and elliptic flow in Au+Au collisions at √sNN=62.4 GeV

    DOE PAGESBeta

    Adare, A.

    2015-04-28

    In this study, we present measurements of electrons and positrons from the semileptonic decays of heavy-flavor hadrons at midrapidity (|y|< 0.35) in Au+Au collisions at √sNN = 62.4 GeV. The data were collected in 2010 by the PHENIX experiment that included the new hadron-blind detector. The invariant yield of electrons from heavy-flavor decays is measured as a function of transverse momentum in the range 1 < peT < 5 GeV/c. The invariant yield per binary collision is slightly enhanced above the p+p reference in Au+Au 0%–20%, 20%–40%, and 40%–60% centralities at a comparable level. At this low beam energy thismore » may be a result of the interplay between initial-state Cronin effects, final-state flow, and energy loss in medium. The v₂ of electrons from heavy-flavor decays is nonzero when averaged between 1.3 < peT < 2.5 GeV/c for 0%–40% centrality collisions at √sNN = 62.4 GeV. For 20%–40% centrality collisions, the v₂ at √sNN = 62.4 GeV is smaller than that for heavy-flavor decays at √sNN = 200 GeV. The v₂ of the electrons from heavy-flavor decay at the lower beam energy is also smaller than v₂ for pions. Both results indicate that the heavy-quarks interact with the medium formed in these collisions, but they may not be at the same level of thermalization with the medium as observed at √sNN = 200 GeV.« less

  12. An experimental study on jets issuing from elliptic inclined nozzles

    NASA Astrophysics Data System (ADS)

    New, T. H.

    2009-06-01

    This paper reports on an experimental flow visualisation and digital particle image velocimetry investigation on forced jets exhausting from aspect ratio equal to three elliptic nozzles with exits inclined at 30° and 60°. Flow images show that shear layer instabilities and subsequent vortex roll-ups are formed parallel to the inclined nozzle exits at 30° incline and that rapid re-orientation of the vortex roll-ups occurs at 60° incline. Flow observations also show that strong axis-switching occurs in a non-inclined elliptic nozzle. However, 30° and 60° elliptic inclined nozzles produce significant distortions to and suppression of the axis-switching behaviour, respectively. As a result, flow stresses and turbulent kinetic energy distributions become increasingly asymmetric. Their coherency and magnitudes along the shorter nozzle lengths also vary significantly. This can be attributed to the dissimilar formations of vortex roll-ups and rib structures, as well as unequal mutual interactions between them as the incline-angle increases. Lastly, results also show that unlike circular inclined nozzles, elliptic inclined nozzles do not produce serpentine-shaped jet columns nor lead to significant lateral jet-spread at large incline-angles.

  13. The elliptic wing based on the potential theory

    NASA Technical Reports Server (NTRS)

    Krienes, Klaus

    1941-01-01

    This article is intended as a contribution to the theory of the lifting surface. The aerodynamics of the elliptic wing in straight and oblique flow are explored on the basis of potential theory. The foundation of the calculation is the linearized theory of the acceleration potential in which all small quantities of higher order are disregarded.

  14. Dynamic separation of nanomagnet sublattices by orientation of elliptical elements

    NASA Astrophysics Data System (ADS)

    Yahagi, Y.; Berk, C. R.; Harteneck, B. D.; Cabrini, S. D.; Schmidt, H.

    2014-04-01

    We report the separation of the magnetization dynamics of densely packed nanomagnets depending on their orientation. The arrays consist of interleaved sublattices of identical nickel elliptical disks. By controlling the orientation of the elliptic disks relative to the external field in each sublattice, we simultaneously analyzed the magnetization dynamics in each sublattice using a time-resolved magnetooptic Kerr effect (TR-MOKE) microscopy system. The Fourier spectra showed clearly separated precession modes for sublattices with different orientations. The spectra were shown to be robust against the error in applied field orientation. The sublattice response can be tuned to a single collective frequency by choosing a symmetric field orientation. We analyzed the effect of the interelement coupling with various spacing between nanomagnets and found a relatively weak dependence on dipolar interactions in good agreement with micromagnetic simulations.

  15. Image Ellipticity from Atmospheric Aberrations

    SciTech Connect

    de Vries, W H; Olivier, S S; Asztalos, S J; Rosenberg, L J; Baker, K L

    2007-03-06

    We investigate the ellipticity of the point-spread function (PSF) produced by imaging an unresolved source with a telescope, subject to the effects of atmospheric turbulence. It is important to quantify these effects in order to understand the errors in shape measurements of astronomical objects, such as those used to study weak gravitational lensing of field galaxies. The PSF modeling involves either a Fourier transform of the phase information in the pupil plane or a ray-tracing approach, which has the advantage of requiring fewer computations than the Fourier transform. Using a standard method, involving the Gaussian weighted second moments of intensity, we then calculate the ellipticity of the PSF patterns. We find significant ellipticity for the instantaneous patterns (up to more than 10%). Longer exposures, which we approximate by combining multiple (N) images from uncorrelated atmospheric realizations, yield progressively lower ellipticity (as 1/{radical}N). We also verify that the measured ellipticity does not depend on the sampling interval in the pupil plane using the Fourier method. However, we find that the results using the ray-tracing technique do depend on the pupil sampling interval, representing a gradual breakdown of the geometric approximation at high spatial frequencies. Therefore, ray tracing is generally not an accurate method of modeling PSF ellipticity induced by atmospheric turbulence unless some additional procedure is implemented to correctly account for the effects of high spatial frequency aberrations. The Fourier method, however, can be used directly to accurately model PSF ellipticity, which can give insights into errors in the statistics of field galaxy shapes used in studies of weak gravitational lensing.

  16. Variational elliptic solver for atmospheric applications

    SciTech Connect

    Smolarkiewicz, P.K.; Margolin, L.G.

    1994-03-01

    We discuss a conjugate gradient type method -- the conjugate residual -- suitable for solving linear elliptic equations that result from discretization of complex atmospheric dynamical problems. Rotation and irregular boundaries typically lead to nonself-adjoint elliptic operators whose matrix representation on the grid is definite but not symmetric. On the other hand, most established methods for solving large sparse matrix equations depend on the symmetry and definiteness of the matrix. Furthermore, the explicit construction of the matrix can be both difficult and computationally expensive. An attractive feature of conjugate gradient methods in general is that they do not require any knowledge of the matrix; and in particular, convergence of conjugate residual algorithms do not rely on symmetry for definite operators. We begin by reviewing some basic concepts of variational algorithms from the perspective of a physical analogy to the damped wave equation, which is a simple alternative to the traditional abstract framework of the Krylov subspace methods. We derive two conjugate residual schemes from variational principles, and prove that either definiteness or symmetry ensures their convergence. We discuss issues related to computational efficiency and illustrate our theoretical considerations with a test problem of the potential flow of a Boussinesq fluid flow past a steep, three-dimensional obstacle.

  17. Elliptical flux vortices in YBa2Cu3O7

    NASA Technical Reports Server (NTRS)

    Hickman, H.; Dekker, A. J.; Chen, T. M.

    1991-01-01

    The most energetically favorable vortex in YBa2Cu3O7 forms perpendicular to an anisotropic plane. This vortex is elliptical in shape and is distinguished by an effective interchange of London penetration depths from one axis of the ellipse to another. By generalizing qualitatively from the isotropic to the anisotropic case, we suggest that the flux flow resistivity for the vortex that forms perpendicular to an anistropic plane should have a preferred direction. Similar reasoning indicates that the Kosterlitz-Thouless transition temperature for a vortex mediated transition should be lower if the vortex is elliptical in shape.

  18. Implementation of Elliptic Curve Cryptography in Binary Field

    NASA Astrophysics Data System (ADS)

    Susantio, D. R.; Muchtadi-Alamsyah, I.

    2016-04-01

    Currently, there is a steadily increasing demand of information security, caused by a surge in information flow. There are many ways to create a secure information channel, one of which is to use cryptography. In this paper, we discuss the implementation of elliptic curves over the binary field for cryptography. We use the simplified version of the ECIES (Elliptic Curve Integrated Encryption Scheme). The ECIES encrypts a plaintext by masking the original message using specified points on the curve. The encryption process is done by separating the plaintext into blocks. Each block is then separately encrypted using the encryption scheme.

  19. Elliptic jets, part 2. Dynamics of coherent structures: Pairing

    NASA Technical Reports Server (NTRS)

    Husain, Hyder S.; Hussain, Fazle

    1992-01-01

    The dynamics of the jet column mode of vortex pairing in the near field of an elliptic jet was investigated. Hot-wire measurements and flow visualization were used to examine the details of the pairing mechanism of nonplanar vortical elliptic structures and its effect on such turbulence measures as coherent velocities, incoherent turbulence intensities, incoherent and coherent Reynolds, stresses, turbulence production, and mass entrainment. It was found that pairing of elliptic vortices in the jet column does not occur uniformly around the entire perimeter, unlike in a circular jet. Merger occurs only in the initial major-axis plane. In the initial minor-axis plane, the trailing vortex rushes through the leading vortex without pairing and then breaks down violently, producing considerably greater entrainment and mixing than in circular or plane jets.

  20. Evolution of a barotropic shear layer into elliptical vortices.

    PubMed

    Guha, Anirban; Rahmani, Mona; Lawrence, Gregory A

    2013-01-01

    When a barotropic shear layer becomes unstable, it produces the well-known Kelvin-Helmholtz instability (KHI). The nonlinear manifestation of the KHI is usually in the form of spiral billows. However, a piecewise linear shear layer produces a different type of KHI characterized by elliptical vortices of constant vorticity connected via thin braids. Using direct numerical simulation and contour dynamics, we show that the interaction between two counterpropagating vorticity waves is solely responsible for this KHI formation. We investigate the oscillation of the vorticity wave amplitude, the rotation and nutation of the elliptical vortex, and straining of the braids. Our analysis also provides a possible explanation for the formation and evolution of elliptical vortices appearing in geophysical and astrophysical flows, e.g., meddies, stratospheric polar vortices, Jovian vortices, Neptune's Great Dark Spot, and coherent vortices in the wind belts of Uranus. PMID:23410439

  1. Numerical Investigation of Viscous Dissipation in Elliptic Microducts

    NASA Astrophysics Data System (ADS)

    Vocale, P.; Puccetti, G.; Morini, G. L.; Spiga, M.

    2014-11-01

    In this work a numerical analysis of heat transfer in elliptical microchannels heated at constant and uniform heat flux is presented. A gaseous flow has been considered, in laminar steady state condition, in hydrodynamically and thermally fully developed forced convection, accounting for the rarefaction effects. The velocity and temperature distributions have been determined in the elliptic cross section, for different values of aspect ratio, Knudsen number and Brinkman number, solving the Navier-Stokes and energy equations within the Comsol Multiphysics® environment. The numerical procedure has been validated resorting to data available in literature for slip flow in elliptic cross sections with Br =0 and for slip flow in circular ducts with Br > 0. The comparison between numerical results and data available in literature shows a perfect agreement. The velocity and temperature distributions thus found have been used to calculate the average Nusselt number in the cross section. The numerical results for Nusselt number are presented in terms of rarefaction degree (Knudsen number), of viscous dissipation (Brinkman number), and of the aspect ratio. The results point out that the thermal fluid behavior is significantly affected by the viscous dissipation for low rarefaction degrees and for aspect ratios of the elliptic cross-section higher than 0.2.

  2. Evolution of an elliptic vortex ring in a viscous fluid

    NASA Astrophysics Data System (ADS)

    Cheng, M.; Lou, J.; Lim, T. T.

    2016-03-01

    The evolution of a viscous elliptic vortex ring in an initially quiescent fluid or a linear shear flow is numerically simulated using a lattice Boltzmann method. A wide range of parameters are considered, namely, aspect ratios (AR) (1 ≤ AR ≤ 8), core radius to ring radius ratios (σ0) (0.1 ≤ σ0 ≤ 0.3), Reynolds number (Re) (500 ≤ Re ≤ 3000), and shear rate (K) (0 ≤ K ≤ 0.12). The study aims to fill the gap in the current knowledge of the dynamics of an elliptic vortex ring in a viscous fluid and also to address the issue of whether an elliptic ring undergoes vortex stretching and compression during axis-switching. In a quiescent fluid, results show that for fixed Re and σ0, there exists a critical aspect ratio (ARc), below which an elliptic ring undergoes oscillatory deformation with the period that increases with increasing AR. Above ARc, the vortex ring breaks up into two or three sub-rings after the first half-cycle of oscillation. While higher Reynolds number enhances vortex ring breakup, larger core size has the opposite effect. Contrary to an inviscid theory, an elliptic ring does undergo vortex stretching and compression during oscillatory deformation. In the presence of a linear shear flow, the vortex ring undergoes not only oscillatory deformation and stretching but also tilting as it propagates downstream. The tilting angle increases with the shear rate K and is responsible for inducing a "tail" that consists of a counter-rotating vortex pair (CVP) near the upstream end of the initial major axis after the first half-cycle of oscillation. For a high shear rate, the CVP wraps around the ring and transforms its topological structure from a simple elliptic geometry to a complicated structure that eventually leads to the generation of turbulence.

  3. Energy and the Elliptical Orbit

    NASA Astrophysics Data System (ADS)

    Nettles, Bill

    2009-03-01

    In the January 2007 issue of The Physics Teacher, Prentis, Fulton, Hesse, and Mazzino describe a laboratory exercise in which students use a geometrical analysis inspired by Newton to show that an elliptical orbit and an inverse-square law force go hand in hand. The historical, geometrical, and teamwork aspects of the exercise are useful and important. This paper presents an exercise which uses an energy/angular momentum conservation model for elliptical orbits. This exercise can be done easily by an individual student and on regular notebook-sized paper.

  4. The Initial Flow of Classical Gluon Fields in Heavy Ion Collisions

    NASA Astrophysics Data System (ADS)

    Fries, Rainer J.; Chen, Guangyao

    2015-03-01

    Using analytic solutions of the Yang-Mills equations we calculate the initial flow of energy of the classical gluon field created in collisions of large nuclei at high energies. We find radial and elliptic flow which follows gradients in the initial energy density, similar to a simple hydrodynamic behavior. In addition we find a rapidity-odd transverse flow field which implies the presence of angular momentum and should lead to directed flow in final particle spectra. We trace those energy flow terms to transverse fields from the non-abelian generalization of Gauss' Law and Ampere's and Faraday's Laws.

  5. Constructing massive blue elliptical galaxies in the local universe

    NASA Astrophysics Data System (ADS)

    Haines, Tim

    Over cosmic time, galaxy mass assembly has transitioned from low-mass, star-forming disk galaxies to massive, quiescent elliptical galaxies. The merger hypothesis for the formation of new elliptical galaxies provides one physical explanation to the observed buildup of this population, a key prediction of which is a brief phase of morphological transformation from highly-disturbed remnant to blue elliptical. We study 12 plausible new ellipticals with varying degrees of morphological peculiarities visually selected from a larger parent sample of nearby (0.01 ≤ z ≤ 0.04), massive (M* ≥ 10 10 M⊙ ), concentrated (Petrosian R90/R50 ≥ 2.6), and optically blue galaxies from the SDSS DR4 catalog. Using integral field spectroscopy, we construct two-dimensional spectra of the stellar populations and azimuthally bin them into concentric annuli to determine the relative ages of the stellar populations as a function of radius. Using this data and conclusions from simulations, we seek to distinguish post-mergers from galaxies undergoing other modes of mass assembly. We find that 1/3 of our sample is consistent with having undergone a recent, gas-rich major merger. Another 1/3 of our sample is consistent with having undergone a 'frosting' of recent star formation. The final 1/3 of our sample is either inconsistent with or inconclusive of having undergone a recent, gas-rich major merger.

  6. Wavelength meter having elliptical wedge

    DOEpatents

    Hackel, Richard P.; Feldman, Mark

    1992-01-01

    A wavelength meter is disclosed which can determine the wavelength of a laser beam from a laser source within an accuracy range of two parts in 10.sup.8. The wavelength meter has wedge having an elliptically shaped face to the optical path of the laser source and includes interferometer plates which form a vacuum housing.

  7. Energy and the Elliptical Orbit

    ERIC Educational Resources Information Center

    Nettles, Bill

    2009-01-01

    In the January 2007 issue of "The Physics Teacher," Prentis, Fulton, Hesse, and Mazzino describe a laboratory exercise in which students use a geometrical analysis inspired by Newton to show that an elliptical orbit and an inverse-square law force go hand in hand. The historical, geometrical, and teamwork aspects of the exercise are useful and…

  8. Wavelength meter having elliptical wedge

    DOEpatents

    Hackel, R.P.; Feldman, M.

    1992-12-01

    A wavelength meter is disclosed which can determine the wavelength of a laser beam from a laser source within an accuracy range of two parts in 10[sup 8]. The wavelength meter has wedge having an elliptically shaped face to the optical path of the laser source and includes interferometer plates which form a vacuum housing. 7 figs.

  9. Liouville Theory and Elliptic Genera

    NASA Astrophysics Data System (ADS)

    Taormina, A.

    The structure and modular properties of N = 4 superconformal characters are reviewed and exploited, in an attempt to construct elliptic genera-like functions by decompactifying K_3. The construction is tested against expressions obtained in the context of strings propagating in background ALE spaces of type A_{N-1}, using the underlying superconformal theory N = 2 minimal ⊗ N = 2 Liouville.

  10. Fourier Series and Elliptic Functions

    ERIC Educational Resources Information Center

    Fay, Temple H.

    2003-01-01

    Non-linear second-order differential equations whose solutions are the elliptic functions "sn"("t, k"), "cn"("t, k") and "dn"("t, k") are investigated. Using "Mathematica", high precision numerical solutions are generated. From these data, Fourier coefficients are determined yielding approximate formulas for these non-elementary functions that are…

  11. The ESS elliptical cavity cryomodules

    NASA Astrophysics Data System (ADS)

    Darve, Christine; Bosland, Pierre; Devanz, Guillaume; Olivier, Gilles; Renard, Bertrand; Thermeau, Jean-Pierre

    2014-01-01

    The European Spallation Source (ESS) is a multi-disciplinary research centre under design and construction in Lund, Sweden. This new facility is funded by a collaboration of 17 European countries and is expected to be up to 30 times brighter than today's leading facilities and neutron sources. The ESS will enable new opportunities for researchers in the fields of life sciences, energy, environmental technology, cultural heritage and fundamental physics. A 5 MW long pulse proton accelerator is used to reach this goal. The pulsed length is 2.86 ms, the repetition frequency is 14 Hz (4 % duty cycle), and the beam current is 62.5 mA. The superconducting section of the Linac accelerates the beam from 80 MeV to 2.0 GeV. It is composed of one string of spoke cavity cryomodule and two strings of elliptical cavity cryomodules. These cryomodules contain four elliptical Niobium cavities operating at 2 K and at a frequency of 704.42 MHz. This paper introduces the thermo-mechanical design, the prototyping and the expected operation of the ESS elliptical cavity cryomodules. An Elliptical Cavity Cryomodule Technology Demonstrator (ECCTD) will be built and tested in order to validate the ESS series production.

  12. The ESS elliptical cavity cryomodules

    SciTech Connect

    Darve, Christine; Bosland, Pierre; Devanz, Guillaume; Renard, Bertrand; Olivier, Gilles; Thermeau, Jean-Pierre

    2014-01-29

    The European Spallation Source (ESS) is a multi-disciplinary research centre under design and construction in Lund, Sweden. This new facility is funded by a collaboration of 17 European countries and is expected to be up to 30 times brighter than today’s leading facilities and neutron sources. The ESS will enable new opportunities for researchers in the fields of life sciences, energy, environmental technology, cultural heritage and fundamental physics. A 5 MW long pulse proton accelerator is used to reach this goal. The pulsed length is 2.86 ms, the repetition frequency is 14 Hz (4 % duty cycle), and the beam current is 62.5 mA. The superconducting section of the Linac accelerates the beam from 80 MeV to 2.0 GeV. It is composed of one string of spoke cavity cryomodule and two strings of elliptical cavity cryomodules. These cryomodules contain four elliptical Niobium cavities operating at 2 K and at a frequency of 704.42 MHz. This paper introduces the thermo-mechanical design, the prototyping and the expected operation of the ESS elliptical cavity cryomodules. An Elliptical Cavity Cryomodule Technology Demonstrator (ECCTD) will be built and tested in order to validate the ESS series production.

  13. Age and metallicity gradients in fossil ellipticals

    NASA Astrophysics Data System (ADS)

    Eigenthaler, P.; Zeilinger, W. W.

    2013-05-01

    Context. Fossil galaxy groups are speculated to be old and highly evolved systems of galaxies that formed early in the universe and had enough time to deplete their L∗ galaxies through successive mergers of member galaxies, building up one massive central elliptical, but retaining the group X-ray halo. Aims: Considering that fossils are the remnants of mergers in ordinary groups, the merger history of the progenitor group is expected to be imprinted in the fossil central galaxy (FCG). We present for the first time radial gradients of single-stellar population (SSP) ages and metallicites in a sample of FCGs to constrain their formation scenario. We also measure line-strength gradients for the strongest absorption features in these galaxies. Methods: We took deep spectra with the long-slit spectrograph ISIS at the William Herschel Telescope (WHT) for six FCGs. The obtained spectra are fit with Pegase HR SSP models within the full-spectrum fitting package ULySS yielding SSP ages and metallicities of the stellar populations. We measure radial gradients of SSP ages and metallicities along the major axes. Lick indices are measured for the strongest absorption features to determine line-strength gradients and compare with the full-spectrum fitting results. Results: Our sample comprises some of the most massive galaxies in the universe exhibiting an average central velocity dispersion of σ0 = 271 ± 28 km s-1. Metallicity gradients are throughout negative with comparatively flat slopes of ∇[Fe/H] = -0.19 ± 0.08 while age gradients are found to be insignificant (∇age = 0.00 ± 0.05). All FCGs lie on the fundamental plane, suggesting that they are virialised systems. We find that gradient strengths and central metallicities are similar to those found in cluster ellipticals of similar mass. Conclusions: The comparatively flat metallicity gradients with respect to those predicted by monolithic collapse (∇Z = -0.5) suggest that fossils are indeed the result of

  14. Splitting of Forced Elliptic Jets and Flames

    NASA Technical Reports Server (NTRS)

    Hertzberg, J.; Carlton, J.; Schwieterman, M.; Davis, E.; Bradley, E.; Linne, M.

    1997-01-01

    The objective of this work is to understand the fluid dynamics in the interaction of large scale, three-dimensional vortex structures and transitional diffusion flames in a microgravity environment. The vortex structures are used to provide a known perturbation of the type used in passive and active shear layer control techniques. 'Passive techniques' refers to manipulation of the system geometry to influence the three dimensional dynamics of vortex structures, and 'active' refers to any technique which adds energy (acoustic or kinetic) to the flow to influence the shear layer vortex dynamics. In this work the passive forcing is provided by an elliptic jet cross-section, and the active forcing is incorporated by perturbing the jet velocity using a loudspeaker in the plenum section.

  15. Spectral multigrid methods for elliptic equations

    NASA Technical Reports Server (NTRS)

    Zang, T. A.; Wong, Y. S.; Hussaini, M. Y.

    1981-01-01

    An alternative approach which employs multigrid concepts in the iterative solution of spectral equations was examined. Spectral multigrid methods are described for self adjoint elliptic equations with either periodic or Dirichlet boundary conditions. For realistic fluid calculations the relevant boundary conditions are periodic in at least one (angular) coordinate and Dirichlet (or Neumann) in the remaining coordinates. Spectral methods are always effective for flows in strictly rectangular geometries since corners generally introduce singularities into the solution. If the boundary is smooth, then mapping techniques are used to transform the problem into one with a combination of periodic and Dirichlet boundary conditions. It is suggested that spectral multigrid methods in these geometries can be devised by combining the techniques.

  16. Elliptic integrals: Symmetry and symbolic integration

    SciTech Connect

    Carlson, B.C. |

    1997-12-31

    Computation of elliptic integrals, whether numerical or symbolic, has been aided by the contributions of Italian mathematicians. Tricomi had a strong interest in iterative algorithms for computing elliptic integrals and other special functions, and his writings on elliptic functions and elliptic integrals have taught these subjects to many modern readers (including the author). The theory of elliptic integrals began with Fagnano`s duplication theorem, a generalization of which is now used iteratively for numerical computation in major software libraries. One of Lauricella`s multivariate hypergeometric functions has been found to contain all elliptic integrals as special cases and has led to the introduction of symmetric canonical forms. These forms provide major economies in new integral tables and offer a significant advantage also for symbolic integration of elliptic integrals. Although partly expository the present paper includes some new proofs and proposes a new procedure for symbolic integration.

  17. Hydroforming of elliptical cavities

    DOE PAGESBeta

    Singer, W.; Singer, X.; Jelezov, I.; Kneisel, Peter

    2015-02-27

    Activities of the past several years in developing the technique of forming seamless (weldless) cavity cells by hydroforming are summarized. An overview of the technique developed at DESY for the fabrication of single cells and multicells of the TESLA cavity shape is given and the major rf results are presented. The forming is performed by expanding a seamless tube with internal water pressure while simultaneously swaging it axially. Prior to the expansion the tube is necked at the iris area and at the ends. Tube radii and axial displacements are computer controlled during the forming process in accordance with resultsmore » of finite element method simulations for necking and expansion using the experimentally obtained strain-stress relationship of tube material. In cooperation with industry different methods of niobium seamless tube production have been explored. The most appropriate and successful method is a combination of spinning or deep drawing with flow forming. Several single-cell niobium cavities of the 1.3 GHz TESLA shape were produced by hydroforming. They reached accelerating gradients Eacc up to 35 MV/m after buffered chemical polishing (BCP) and up to 42 MV/m after electropolishing (EP). More recent work concentrated on fabrication and testing of multicell and nine-cell cavities. Several seamless two- and three-cell units were explored. Accelerating gradients Eacc of 30–35 MV/m were measured after BCP and Eacc up to 40 MV/m were reached after EP. Nine-cell niobium cavities combining three three-cell units were completed at the company E. Zanon. These cavities reached accelerating gradients of Eacc = 30–35 MV/m. One cavity is successfully integrated in an XFEL cryomodule and is used in the operation of the FLASH linear accelerator at DESY. Additionally the fabrication of bimetallic single-cell and multicell NbCu cavities by hydroforming was successfully developed. Several NbCu clad single-cell and double-cell cavities of the TESLA shape have

  18. Hydroforming of elliptical cavities

    NASA Astrophysics Data System (ADS)

    Singer, W.; Singer, X.; Jelezov, I.; Kneisel, P.

    2015-02-01

    Activities of the past several years in developing the technique of forming seamless (weldless) cavity cells by hydroforming are summarized. An overview of the technique developed at DESY for the fabrication of single cells and multicells of the TESLA cavity shape is given and the major rf results are presented. The forming is performed by expanding a seamless tube with internal water pressure while simultaneously swaging it axially. Prior to the expansion the tube is necked at the iris area and at the ends. Tube radii and axial displacements are computer controlled during the forming process in accordance with results of finite element method simulations for necking and expansion using the experimentally obtained strain-stress relationship of tube material. In cooperation with industry different methods of niobium seamless tube production have been explored. The most appropriate and successful method is a combination of spinning or deep drawing with flow forming. Several single-cell niobium cavities of the 1.3 GHz TESLA shape were produced by hydroforming. They reached accelerating gradients Eacc up to 35 MV /m after buffered chemical polishing (BCP) and up to 42 MV /m after electropolishing (EP). More recent work concentrated on fabrication and testing of multicell and nine-cell cavities. Several seamless two- and three-cell units were explored. Accelerating gradients Eacc of 30 - 35 MV /m were measured after BCP and Eacc up to 40 MV /m were reached after EP. Nine-cell niobium cavities combining three three-cell units were completed at the company E. Zanon. These cavities reached accelerating gradients of Eacc=30 - 35 MV /m . One cavity is successfully integrated in an XFEL cryomodule and is used in the operation of the FLASH linear accelerator at DESY. Additionally the fabrication of bimetallic single-cell and multicell NbCu cavities by hydroforming was successfully developed. Several NbCu clad single-cell and double-cell cavities of the TESLA shape have been

  19. Hydroforming of elliptical cavities

    SciTech Connect

    Singer, W.; Singer, X.; Jelezov, I.; Kneisel, Peter

    2015-02-27

    Activities of the past several years in developing the technique of forming seamless (weldless) cavity cells by hydroforming are summarized. An overview of the technique developed at DESY for the fabrication of single cells and multicells of the TESLA cavity shape is given and the major rf results are presented. The forming is performed by expanding a seamless tube with internal water pressure while simultaneously swaging it axially. Prior to the expansion the tube is necked at the iris area and at the ends. Tube radii and axial displacements are computer controlled during the forming process in accordance with results of finite element method simulations for necking and expansion using the experimentally obtained strain-stress relationship of tube material. In cooperation with industry different methods of niobium seamless tube production have been explored. The most appropriate and successful method is a combination of spinning or deep drawing with flow forming. Several single-cell niobium cavities of the 1.3 GHz TESLA shape were produced by hydroforming. They reached accelerating gradients Eacc up to 35 MV/m after buffered chemical polishing (BCP) and up to 42 MV/m after electropolishing (EP). More recent work concentrated on fabrication and testing of multicell and nine-cell cavities. Several seamless two- and three-cell units were explored. Accelerating gradients Eacc of 30–35 MV/m were measured after BCP and Eacc up to 40 MV/m were reached after EP. Nine-cell niobium cavities combining three three-cell units were completed at the company E. Zanon. These cavities reached accelerating gradients of Eacc = 30–35 MV/m. One cavity is successfully integrated in an XFEL cryomodule and is used in the operation of the FLASH linear accelerator at DESY. Additionally the fabrication of bimetallic single-cell and multicell NbCu cavities by hydroforming was successfully developed. Several NbCu clad single-cell and double

  20. Atmospheric Pressure Plasma Jet in Organic Solution: Spectra, Degradation Effects of Solution Flow Rate and Initial pH Value

    NASA Astrophysics Data System (ADS)

    Chen, Bingyan; Zhu, Changping; Chen, Longwei; Fei, Juntao; Gao, Ying; Wen, Wen; Shan, Minglei; Ren, Zhaoxing

    2014-12-01

    The organic compounds of p-nitrophenol (PNP) solution was treated by the active species generated in a stirred reactor by an atmospheric pressure plasma jet (APPJ). The emission intensities of hydroxyl (OH), oxygen (O), nitric oxide (NO), hydrogen (H) and molecular (N2) were measured by optical emission spectroscopy (OES). The relations between the flow rates of the PNP solution and degradation, the degradation effects and initial pH value of the solution were also investigated. Experimental results show that there exist intense emissions of O (777.1 nm), N2 (337.1 nm), OH (306-310 nm) and NO band (200-290 nm) in the region of plasma. Given the treatment time and gas flow rate, the degradation increased as a function of discharge energy and solution flow rate, respectively. The solution flow rate for the most efficient degradation ranged from 1.414 m/s to 1.702 m/s, and contributed very little when it exceeded 2.199 m/s. This indicates the existence of diffusion-controlled reactions at a low solution flow rate and activation-controlled reactions at a high solution flow rate. Moreover, increasing or decreasing the initial pH value of neutral PNP solution (pH=5.95) could improve the degradation efficiency. Treated by APPJ, the PNP solutions with different initial pH values of 5.95, 7.47 and 2.78 turned more acidic in the end, while the neutral solution had the lowest degradation efficiency. This work clearly demonstrates the close coupling of active species, photolysis of ultraviolet, the organic solution flow rate and the initial pH value, and thus is helpful in the study of the mechanism and application of plasma in wastewater treatment.

  1. Resolved difference spectra of redox centers involved in photosynthetic electron flow in Rhodopseudomonas capsulata and Rhodopseudomonas sphaeroides.

    PubMed

    Bowyer, J R; Meinhardt, S W; Tierney, G V; Crofts, A R

    1981-03-12

    1. In Rhodopseudomonas sphaeroides the Qx absorption band of the reaction center bacteriochlorophyll dimer which bleaches on photo-oxidation is both blue-shifted and has an increased extinction coefficient on solubilisation of the chromatophore membrane with lauryldimethylamine-N-oxide. These effects may be attributable in part to the particle flattening effect. 2. The difference spectrum of photo-oxidisable c type cytochrome in the chromatophore was found to have a slightly variable peak position in the alpha-band (lambda max at 551--551.25 nm); this position was always red-shifted in comparison to that of isolated cytochrome c2 (lambda max at 549.5 +/- 0.5 nm). The shift in wavelength maximum was not due to association with the reaction center protein. A possible heterogeneity in the c-type cytochromes of chromatophores is discussed. 3. Flash-induced difference spectra attributed to cytochrome b were resolved at several different redox potentials and in the presence and absence of antimycin. Under most conditions, one major component, cytochrome b50 appeared to be involved. However, in some circumstances, reduction of a component with the spectral characteristics of cytochrome b-90 was observed. 4. Difference spectra attributed to (BChl)2, (Formula: see text), c type cytochrome and cytochrome b50 were resolved in the Soret region for Rhodopseudomonas capsulata. 5. A computer-linked kinetic spectrophotometer for obtaining automatically the difference spectra of components functioning in photosynthetic electron transfer chains is described. The system incorporates a novel method for automatically adjusting and holding the photomultiplier supply voltage. PMID:6260162

  2. Effects of Photon Bending on the Monte-Carlo Comptonized Spectra of Two Component Advective Flow : A Catalogue of Images

    NASA Astrophysics Data System (ADS)

    Chatterjee, Arka; Chakrabarti, Sandip Kumar; Ghosh, Himadri

    2016-07-01

    In a black hole accretion process, Comptonization of photons is a very important phenomenon. Photons generated from the Keplerian disk are intercepted by the hot thick disk which represents CENtrifugal pressure supported BOundary Layer or CENBOL. First, we construct generalized relativistic thick disks for different thermodynamical parameters. Inside the thick disk, we compute comptonization including the trajectory correction for photons due to space-time geometry of the black hole. Spectral difference between null geodesic comptonization and flat space-time comptonization are studied for different scenarios. In the next step, we connect the Comptonized photons to the observer to obtain energy dependent images of the system. We vary the inclination angle of the observer to study the spectral differences of emergent photons. We provide a catalogue of energy dependent images and spectra for future observations.

  3. Do elliptical galaxies have thick disks?

    NASA Technical Reports Server (NTRS)

    Thomson, R. C.; Wright, A. E.

    1990-01-01

    The authors discuss new evidence which supports the existence of thick disks in elliptical/SO galaxies. Numerical simulations of weak interactions with thick disk systems produce shell structures very similar in appearance to those observed in many shell galaxies. The authors think this model presents a more plausible explanation for the formation of shell structures in elliptical/SO galaxies than does the merger model and, if correct, supports the existence of thick disks in elliptical/SO galaxies.

  4. Differential Spectral Synthesis of Low-Luminosity Elliptical Galaxies

    NASA Astrophysics Data System (ADS)

    Jones, Lewis Alexander

    In this thesis, a study of the spectral variations in the integrated light of eight low-luminosity elliptical galaxies is presented. The unique opportunity provided by low-luminosity elliptical galaxies to study integrated spectra at high line definition is the motivation behind the observational approach for this study. A long wavelength baseline is sacrificed in favor of working at high resolution (~2 Å FWHM) with a large variety of narrow absorption features in a smaller wave-length window. A new spectral library has been developed with this approach in mind. The library consists of spectra of 684 stars all observed with the Coudé Feed Telescope and Spectrograph at the Kitt Peak National Observatory, covering the spectral ranges 3820-4500 Å and 4780-5450 Å and at a spectral resolution of ~2 Å FWHM. The coverage of the library is complete for spectral types A-K and luminosity classes I-V, in the range -2.5 <= FeH; <= +0.5, while the O, B, and M stars are near solar. The empirical investigation of the galaxy spectra in reference to the stellar sequences of the spectral library yields several key results. (1) There is a spread in the mean spectral types of the low-luminosity ellliptical galaxies. (2) The galaxies are similar in evolved star content, Fe line strengths, and their evolved star light is dominated by solar type giants. (3) Five of the eight galaxies are shown to contain less than a 5% hot star contribution, which is inconsistent with the prediction of ~10% from the simple model of chemical evolution (Worthey, Dorman, and Jones 1996). (4) From variations in the balance of dwarf and giant light in the galaxy spectra it is claimed that there is a spread in the mean stellar ages of the low-luminosity elliptical galaxies. These results are interpreted in the context of the evolutionary synthesis models of Worthey (1994). The main result from the comparison of the galaxies and models is that the low-luminosity elliptical galaxies show a large spread in

  5. Kinetic freeze-out temperature and flow velocity extracted from transverse momentum spectra of final-state light flavor particles produced in collisions at RHIC and LHC

    NASA Astrophysics Data System (ADS)

    Wei, Hua-Rong; Liu, Fu-Hu; Lacey, Roy A.

    2016-04-01

    The transverse momentum spectra of final-state light flavor particles produced in proton-proton ( p - p , copper-copper (Cu-Cu), gold-gold (Au-Au), lead-lead (Pb-Pb), and proton-lead ( p -Pb) collisions for different centralities at relativistic heavy ion collider (RHIC) and large hadron collider (LHC) energies are studied in the framework of a multisource thermal model. The experimental data measured by the STAR, CMS, and ALICE Collaborations are consistent with the results calculated by the multi-component Erlang distribution and Tsallis Statistics. The effective temperature and real temperature (kinetic freeze-out temperature) of the interacting system at the stage of kinetic freeze-out, the mean transverse flow velocity and mean flow velocity of particles, and the relationships between them are extracted. The dependences of effective temperature and mean (transverse) momentum on rest mass, moving mass, centrality, and center-of-mass energy, and the dependences of kinetic freeze-out temperature and mean (transverse) flow velocity on centrality, center-of-mass energy, and system size are obtained.

  6. Formation and Evolution of Dwarf Elliptical Galaxies

    NASA Astrophysics Data System (ADS)

    Chilingarian, Igor

    2006-11-01

    This thesis presents observational studies of evolution of dwarf elliptical galaxies. dE's are numerically dominant population in clusters of galaxies, but their origin and evolution is a matter of debate. Several scenarios of gas removal from dE's exist: galactic winds, ram pressure stripping, gravitaional harassment. We present new method to estimate stellar population parameters and internal kinematics, based on fitting observed spectra in the pixel space by PEGASE.HR synthetic populations. We apply this technique to 3D-spectroscopic observations of dE galaxies in the Virgo cluster and nearby groups and multiobject spectroscopy of several dozens of dE's in the Abell 496 cluster. We present discovery of young nuclei in bright dE galaxies in the Virgo cluster. Based on the analysis of observational data we conclude that: (1) there is an evolutionary connection between dE's and dIrr's, (2) the most probable scenario of gas removal is ram pressure stripping by the intergalactic medium.

  7. Terahertz electromagnetic wave generation and amplification by an electron beam in the elliptical plasma waveguides with dielectric rod

    SciTech Connect

    Rahmani, Z. Jazi, B.; Heidari-Semiromi, E.

    2014-09-15

    The propagation of electromagnetic waves in an elliptical plasma waveguide including strongly magnetized plasma column and a dielectric rod is investigated. The dispersion relation of guided hybrid electromagnetic waves is obtained. Excitation of the waves by a thin annular relativistic elliptical electron beam will be studied. The time growth rate of electromagnetic waves is obtained. The effects of relative permittivity constant of dielectric rod, radius of dielectric rod, accelerating voltage, and current density of the annular elliptical beam on the growth rate and the frequency spectra are numerically presented.

  8. Elliptical polarization favors long quantum orbits in high-order above-threshold ionization of noble gases.

    PubMed

    Lai, XuanYang; Wang, ChuanLiang; Chen, YongJu; Hu, ZiLong; Quan, Wei; Liu, XiaoJun; Chen, Jing; Cheng, Ya; Xu, ZhiZhan; Becker, Wilhelm

    2013-01-25

    We demonstrate the significant role of long quantum orbits in strong-field atomic processes by investigating experimentally and theoretically the above-threshold ionization spectra of noble gases in intense elliptically polarized laser pulses. With increasing laser ellipticity, the yields of different energy regions of the measured electron spectrum in high-order above-threshold ionization drop at different rates. The experimental features can be reproduced by a theoretical simulation based on quantum-orbit theory, revealing that increasing ellipticity favors the contributions of the long quantum orbits in the high-order above-threshold ionization process. PMID:25166161

  9. Dark matter in elliptical galaxies

    NASA Technical Reports Server (NTRS)

    Carollo, C. M.; Zeeuw, P. T. DE; Marel, R. P. Van Der; Danziger, I. J.; Qian, E. E.

    1995-01-01

    We present measurements of the shape of the stellar line-of-sight velocity distribution out to two effective radii along the major axes of the four elliptical galaxies NGC 2434, 2663, 3706, and 5018. The velocity dispersion profiles are flat or decline gently with radius. We compare the data to the predictions of f = f(E, L(sub z)) axisymmetric models with and without dark matter. Strong tangential anisotropy is ruled out at large radii. We conclude from our measurements that massive dark halos must be present in three of the four galaxies, while for the fourth galaxy (NGC 2663) the case is inconclusive.

  10. Abundance gradients in cooling flow clusters: Ginga Large Area Counters and Einstein Solid State Spectrometer spectra of A496, A1795, A2142, and A2199

    NASA Technical Reports Server (NTRS)

    White, Raymond E., III; Day, C. S. R.; Hatsukade, Isamu; Hughes, John P.

    1994-01-01

    We analyze the Ginga Large Area Counters (LAC) and Einstein Solid State Spectrometer (SSS) spectra of four cooling flow clusters, A496, A1795, A2142, and A2199, each of which shows firm evidence of a relatively cool component. The inclusion of such cool spectral components in joint fits of SSS and LAC data leads to somewhat higher global temperatures than are derived from the high-energy LAC data alone. We find little evidence of cool emission outside the SSS field of view. Metal abundances appear to be centrally enhanced in all four clusters, with varying degrees of model dependence and statistical significance: the evidence is statistically strongest for A496 and A2142, somewhat weaker for A2199 and weakest for A1795. We also explore the model dependence in the amount of cold, X-ray-absorbing matter discovered in these clusters by White et al.

  11. Isolated elliptical galaxies in the local Universe

    NASA Astrophysics Data System (ADS)

    Lacerna, I.; Hernández-Toledo, H. M.; Avila-Reese, V.; Abonza-Sane, J.; del Olmo, A.

    2016-04-01

    Context. We have studied a sample of 89 very isolated, elliptical galaxies at z < 0.08 and compared their properties with elliptical galaxies located in a high-density environment such as the Coma supercluster. Aims: Our aim is to probe the role of environment on the morphological transformation and quenching of elliptical galaxies as a function of mass. In addition, we elucidate the nature of a particular set of blue and star-forming isolated ellipticals identified here. Methods: We studied physical properties of ellipticals, such as color, specific star formation rate, galaxy size, and stellar age, as a function of stellar mass and environment based on SDSS data. We analyzed the blue and star-forming isolated ellipticals in more detail, through photometric characterization using GALFIT, and infer their star formation history using STARLIGHT. Results: Among the isolated ellipticals ≈20% are blue, ≲8% are star forming, and ≈10% are recently quenched, while among the Coma ellipticals ≈8% are blue and just ≲1% are star forming or recently quenched. There are four isolated galaxies (≈4.5%) that are blue and star forming at the same time. These galaxies, with masses between 7 × 109 and 2 × 1010 h-2 M⊙, are also the youngest galaxies with light-weighted stellar ages ≲1 Gyr and exhibit bluer colors toward the galaxy center. Around 30-60% of their present-day luminosity, but only <5% of their present-day mass, is due to star formation in the last 1 Gyr. Conclusions: The processes of morphological transformation and quenching seem to be in general independent of environment since most of elliptical galaxies are "red and dead", although the transition to the red sequence should be faster for isolated ellipticals. In some cases, the isolated environment seems to propitiate the rejuvenation of ellipticals by recent (<1 Gyr) cold gas accretion.

  12. Matrix factorizations and elliptic fibrations

    NASA Astrophysics Data System (ADS)

    Omer, Harun

    2016-09-01

    I use matrix factorizations to describe branes at simple singularities of elliptic fibrations. Each node of the corresponding Dynkin diagrams of the ADE-type singularities is associated with one indecomposable matrix factorization which can be deformed into one or more factorizations of lower rank. Branes with internal fluxes arise naturally as bound states of the indecomposable factorizations. Describing branes in such a way avoids the need to resolve singularities. This paper looks at gauge group breaking from E8 fibers down to SU (5) fibers due to the relevance of such fibrations for local F-theory GUT models. A purpose of this paper is to understand how the deformations of the singularity are understood in terms of its matrix factorizations. By systematically factorizing the elliptic fiber equation, this paper discusses geometries which are relevant for building semi-realistic local models. In the process it becomes evident that breaking patterns which are identical at the level of the Kodaira type of the fibers can be inequivalent at the level of matrix factorizations. Therefore the matrix factorization picture supplements information which the conventional less detailed descriptions lack.

  13. Advanced Light Source elliptical wiggler

    SciTech Connect

    Hoyer, E.; Akre, J.; Humphries, D.; Marks, S.; Minamihara, Y.; Pipersky, P.

    1994-07-01

    A 3.5m long elliptical wiggler, optimized to produce elliptically polarized light in the 50 eV to 10 keV range, is currently under design and construction at the Advanced Light Source (ALS) at Lawrence Berkeley Laboratory. Calculations of spectral performance show that the flux of circularly polarized photons exceeds 10{sup 13} photons/sec over the 50 eV to 10 keV operating range for current of 0.4 amps and 1.5 GeV electron energy. This device features vertical and horizontal magnetic structures of 14 and 14{1/2} periods respectively. The period length is 20.0 cm. The vertical structure is a hybrid permanent magnet design with tapered pole tips that produce a peak field of 2.0 T. The horizontal structure is an iron core electromagnetic design, shifted longitudinally {1/4} period, that is tucked between the upper and lower vertical magnetic structure sections. A maximum peak oscillating field of 0.095 T at a frequency up to 1 Hz will be achieved by excitation of the horizontal poles with a trapezoidal current waveform. The vacuum chamber is an unconventional design that is removable from the magnetic structure, after magnetic measurements, for UHV processing. The chamber is fabricated from non-magnetic stainless steel to minimize the effects of eddy currents. Device design is presented.

  14. Shaping the beam profile of an elliptical Gaussian beam by an elliptical phase aperture

    NASA Astrophysics Data System (ADS)

    Wen, Wei; Wu, Gaofeng; Song, Kehui; Dong, Yiming

    2013-03-01

    Based on the generalized Collins integral formula, an analytical paraxial propagation formula for an elliptical Gaussian beam (EGB) passing through an astigmatic ABCD optical system with an elliptical phase aperture is derived by use of a tensor method. As an application example, we study the propagation properties of an EGB passing through an elliptical aperture in free space. It is found that the elliptical phase aperture can be used for shaping the beam profile of an EGB, which is useful in many applications, such as free space optical communication and material thermal processing. The elliptical phase aperture induced changes of the propagation factors of an EGB are also analyzed.

  15. Simultaneous measurement of x-ray absorption spectra and kinetics : a fixed-bed, plug-flow operando reactor.

    SciTech Connect

    Fingland, B. R.; Ribeiro, F. H.; Miller, J. T.; Purdue Univ.

    2009-08-01

    An inexpensive fixed-bed, plug-flow operando reactor is described in which X-ray absorbance and kinetic data can be measured simultaneously. Pt L3 (11.56 keV) XANES and EXAFS data were obtained on a 1.5% Pt/silica catalyst in borosilicate glass reactors of different diameters, 3-6 mm, and thicknesses, 0.3-1.2 mm, some of which are capable of operation at pressures up to about 40 atm. Additionally, polyimide tubular reactors with low absorbance can be used for lower energy edges of the 3d transition metals, or fluorescence detection for low concentration or highly absorbing supports. With the polyimide reactor, however, the pressure is limited to {approx}3.5 atm and the reaction temperature to about 300 C. To validate the reactor, the rate and activation energies for the water-gas shift reaction on 2% Pd, 13.7% Zn on Al2O3 catalyst were within 15% of those obtained in a standard laboratory reactor, which is within laboratory reproducibility. In addition, the Pd K edge (24.35 keV) XANES and EXAFS data on pre-reduced catalyst were identical to that previously determined on a regular cell. The EXAFS data show that the degree of Pd-Zn alloy formation changes with reaction temperature demonstrating the importance of characterizing the catalyst under reaction conditions.

  16. Photoelectron momentum distributions of the hydrogen atom driven by multicycle elliptically polarized laser pulses

    NASA Astrophysics Data System (ADS)

    Murakami, Mitsuko; Chu, Shih-I.

    2016-02-01

    Photoelectron momentum distributions (PMDs) of the hydrogen atom driven by multicycle elliptically polarized strong laser fields are studied in detail, based on the numerical solution of the time-dependent Schrödinger equation and the Volkov wave propagation. Both short and long driving pulses of the 800-nm field are considered, as well as the ellipticity dependence, to describe the mechanism of symmetry breaking in the hydrogen-atom PMD. Moreover, we demonstrate that the value of a retardation angle in the longitudinal PMD can depend on the order of above-threshold ionization spectra.

  17. Metallicity and the level of the ultraviolet rising branch in elliptical galaxies

    NASA Technical Reports Server (NTRS)

    Faber, S. M.

    1986-01-01

    This final report concerns a project to study the systematics of the ultraviolet flux level in elliptical galaxies. Prior to the inception of this work, the systematic behavior of the ultraviolet flux level was basically unknown and ultraviolet fluxes were observed to vary greatly from galaxy to galaxy. There was a suggestion, however, that there might be a dependence of ultraviolet flux on galaxy metallicity, but the correlation was based on just six galaxies. IUE spectra of elliptical galaxies have been reanalyzed and placed on a consistent, homogenous flux system. The major conclusion is a confirmation of the original hypothesis: galaxies with stronger Mg2 lines show enhanced ultraviolet flux.

  18. Euler characteristics and elliptic curves.

    PubMed

    Coates, J; Howson, S

    1997-10-14

    Let E be a modular elliptic curve over [symbol, see text], without complex multiplication; let p be a prime number where E has good ordinary reduction; and let Finfinity be the field obtained by adjoining [symbol, see text] to all p-power division points on E. Write Ginfinity for the Galois group of Finfinity over [symbol, see text]. Assume that the complex L-series of E over [symbol, see text] does not vanish at s = 1. If p >/= 5, we make a precise conjecture about the value of the Ginfinity-Euler characteristic of the Selmer group of E over Finfinity. If one makes a standard conjecture about the behavior of this Selmer group as a module over the Iwasawa algebra, we are able to prove our conjecture. The crucial local calculations in the proof depend on recent joint work of the first author with R. Greenberg. PMID:11607752

  19. Elliptical orbit performance computer program

    NASA Technical Reports Server (NTRS)

    Myler, T. R.

    1981-01-01

    A FORTRAN coded computer program which generates and plots elliptical orbit performance capability of space boosters for presentation purposes is described. Orbital performance capability of space boosters is typically presented as payload weight as a function of perigee and apogee altitudes. The parameters are derived from a parametric computer simulation of the booster flight which yields the payload weight as a function of velocity and altitude at insertion. The process of converting from velocity and altitude to apogee and perigee altitude and plotting the results as a function of payload weight is mechanized with the ELOPE program. The program theory, user instruction, input/output definitions, subroutine descriptions and detailed FORTRAN coding information are included.

  20. The elliptical multipole wiggler project

    SciTech Connect

    Gluskin, E.; Frachon, D.; Ivanov, P.M.

    1995-06-01

    The elliptical multipole wiggler (EMW) has been designed, constructed, and installed in the X13 straight section of the NSLS X-ray Ring. The EMW generates circularly polarized photons in the energy range of 0.1-10 keV with AC modulation of polarization helicity. The vertical magnetic field of 0.8 T is produced by a hybrid permanent magnet structure with a period of 16 cm. The horizontal magnetic field of 0.22 T is generated by an electromagnet, the core of which is fabricated from laminated iron to operate with a switching frequency up to 100 Hz. There are dynamic compensation trim magnets at the wiggler ends to control the first and second field integrals with very high accuracy throughout the AC cycle. The residual closed orbit motion due to the electromagnet AC operation is discussed.

  1. Elliptic Functions with Disconnected Julia Sets

    NASA Astrophysics Data System (ADS)

    Koss, Lorelei

    2016-06-01

    In this paper, we investigate elliptic functions of the form fΛ = 1/(1 + (℘Λ)2), where ℘Λ is the Weierstrass elliptic function on a real rhombic lattice. We show that a typical function in this family has a superattracting fixed point at the origin and five other equivalence classes of critical points. We investigate conditions on the lattice which guarantee that fΛ has a double toral band, and we show that this family contains the first known examples of elliptic functions for which the Julia set is disconnected but not Cantor.

  2. Mapping Elliptical Orbits Around Europa

    NASA Astrophysics Data System (ADS)

    Vilhena de Moraes, Rodolpho; Prado, Antonio; Carvalho, Jean Paulo; Cardoso dos Santos, Josué

    Due to specifics scientific purposes space missions has been proposed to explore natural satellites, comets and asteroids sending artificial satellites orbiting around these bodies. The planning of such missions must be taken into account a good choice for the orbits that reduces the cost related to station-keeping and the increasing the duration of the mission. The present research has the objective of using a new concept to map with respect the station-keeping maneuvers to study elliptical orbits around Europa. This concept is based in the integral of the perturbing forces over the time. This value can estimate the total variation of velocity received by the spacecraft from the perturbations forces acting on it. The value of this integral is a characteristic of the perturbations considered and the orbit chosen for the spacecraft. Numerical simulations are made showing the value of this integral for orbits around Europa as a function of the eccentricity and semi-major axis of the orbits. An important application of the present research is in the search for frozen orbits.

  3. Elliptical lobe shape gerotor pump design to minimize wear

    NASA Astrophysics Data System (ADS)

    Karamooz Ravari, Mohammad Reza

    2011-12-01

    The gerotor pumps are the most important parts of mechanical equipment that have a vast number of applications in industries and automobiles. Because the gerotor pumps cannot be adjusted for wear so it is important to reduce the wear as much as possible. In this paper first mathematical equations for elliptical lobe shape rotors profile and curvature of them have been derived and then Specific flow and wear rate proportional factor (WRPF) have been formulated. To reach the minimum wear in rotors teeth, the ellipse shape factor is changed for each value of number of outer rotor teeth in a feasible range and wear rate proportional factor has been resulted. Also in order to have better comparison specific flow has been presented. The obtained results have been compared with circular pumps with similar geometrical parameters and show the significant improvement in wear of the rotors with negligible changes in the specific flow.

  4. Slender body treatment of some specialized problems associated with elliptic-cross-section missile configurations

    NASA Technical Reports Server (NTRS)

    Barger, R. L.

    1977-01-01

    Slender body methods were applied to some specialized problems associated with missile configurations with elliptic cross sections. Expressions are derived for computing the velocity distribution on the nose section when the ellipse eccentricity is varying longitudinally on the missile. The cross flow velocity on a triform fin section is also studied.

  5. A halo model for intrinsic alignments of galaxy ellipticities

    NASA Astrophysics Data System (ADS)

    Schneider, Michael D.; Bridle, Sarah

    2010-03-01

    Correlations between intrinsic ellipticities of galaxies are a potentially important systematic error when constraining dark energy properties from weak gravitational lensing (cosmic shear) surveys. In the absence of perfectly known galaxy redshifts, some modelling of the galaxy intrinsic alignments is likely to be required to extract the lensing signal to sufficient accuracy. We present a new model based on the placement of galaxies into dark matter haloes. The central galaxy ellipticity follows the large-scale potential and, in the simplest case, the satellite galaxies point at the halo centre. The two-halo term is then dominated by the linear-alignment model and the one-halo term provides a motivated extension of intrinsic alignment models to small scales. We provide fitting formulae for the spatial projected source power spectra for both intrinsic-intrinsic (II) and gravitational-intrinsic (GI) correlations. We illustrate the potential impact of ignoring intrinsic alignments on cosmological parameter constraints from non-tomographic surveys, finding that σ8 could be underestimated by up to the size of the current 1σ error bar from cosmic shear if very small scales are included in the analysis. Finally, we highlight areas of interest for numerical simulations of dark matter clustering and galaxy formation that can further constrain the intrinsic alignment signal.

  6. Energy shell structure in a dielectric elliptic microcavity.

    PubMed

    Yi, Chang-Hwan; Yu, Hyeon-Hye; Lee, Ji-Won; Kim, Ji-Hwan; Kim, Chil-Min

    2016-01-01

    An energy shell structure depending on eccentricity is analyzed in a dielectric elliptic microcavity. Through the analysis, it is explicated that the energy shell structure is governed by classical constant actions of periodic orbits. For clarification, the relation between dominances of the periodic orbits and bifurcation behaviors are obtained and the length spectra based on eigenvalues computed by a numerical method are compared with the exact lengths of the periodic orbits obtained by analytic calculations. By matching effective wave numbers obtained from the periodic orbit lengths to exact wave numbers of stationary states in closed and open cavities, we find deviations provoked from the openness. We show that these deviations are caused by additional phase factors in the Einstein-Brillouin-Keller quantization. PMID:26871069

  7. Energy shell structure in a dielectric elliptic microcavity

    NASA Astrophysics Data System (ADS)

    Yi, Chang-Hwan; Yu, Hyeon-Hye; Lee, Ji-Won; Kim, Ji-Hwan; Kim, Chil-Min

    2016-01-01

    An energy shell structure depending on eccentricity is analyzed in a dielectric elliptic microcavity. Through the analysis, it is explicated that the energy shell structure is governed by classical constant actions of periodic orbits. For clarification, the relation between dominances of the periodic orbits and bifurcation behaviors are obtained and the length spectra based on eigenvalues computed by a numerical method are compared with the exact lengths of the periodic orbits obtained by analytic calculations. By matching effective wave numbers obtained from the periodic orbit lengths to exact wave numbers of stationary states in closed and open cavities, we find deviations provoked from the openness. We show that these deviations are caused by additional phase factors in the Einstein-Brillouin-Keller quantization.

  8. Ultraluminous Infrared Mergers: Elliptical Galaxies in Formation?

    NASA Astrophysics Data System (ADS)

    Genzel, R.; Tacconi, L. J.; Rigopoulou, D.; Lutz, D.; Tecza, M.

    2001-12-01

    We report high-quality near-IR spectroscopy of 12 ultraluminous infrared galaxy mergers (ULIRGs). Our new VLT and Keck data provide ~0.5" resolution, stellar and gas kinematics of these galaxies, most of which are compact systems in the last merger stages. We confirm that ULIRG mergers are ``ellipticals in formation.'' Random motions dominate their stellar dynamics, but significant rotation is common. Gasdynamics and stellar dynamics are decoupled in most systems. ULIRGs fall on or near the fundamental plane of hot stellar systems, and especially on its less evolution-sensitive, reff-σ projection. The ULIRG velocity dispersion distribution, their location in the fundamental plane, and their distribution of vrotsini/σ closely resemble those of intermediate-mass (~L*), elliptical galaxies with moderate rotation. As a group ULIRGs do not resemble giant ellipticals with large cores and little rotation. Our results are in good agreement with other recent studies indicating that disky ellipticals with compact cores or cusps can form through dissipative mergers of gas-rich disk galaxies while giant ellipticals with large cores have a different formation history. Based on observations at the European Southern Observatory, Chile (ESO 65.N-0266, 65.N-0289), and on observations at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, The University of California, and the National Aeronautics and Space Administration. The Keck Observatory was made possible by the general financial support by the W. M. Keck Foundation.

  9. Vortex dynamics in thin elliptic ferromagnetic nanodisks

    NASA Astrophysics Data System (ADS)

    Wysin, G. M.

    2015-10-01

    Vortex gyrotropic motion in thin ferromagnetic nanodisks of elliptical shape is described here for a pure vortex state and for a situation with thermal fluctuations. The system is analyzed using numerical simulations of the Landau-Lifshitz-Gilbert (LLG) equations, including the demagnetization field calculated with a Green's function approach for thin film problems. At finite temperature the thermalized dynamics is found using a second order Heun algorithm for a magnetic Langevin equation based on the LLG equations. The vortex state is stable only within a limited range of ellipticity, outside of which a quasi-single-domain becomes the preferred minimum energy state. A vortex is found to move in an elliptical potential, whose force constants along the principal axes are determined numerically. The eccentricity of vortex motion is directly related to the force constants. Elliptical vortex motion is produced spontaneously by thermal fluctuations. The vortex position and velocity distributions in thermal equilibrium are Boltzmann distributions. The results show that vortex motion in elliptical disks can be described by a Thiele equation.

  10. Elastodynamics and resonances in elliptical geometry

    NASA Astrophysics Data System (ADS)

    Ancey, S.; Bazzali, E.; Gabrielli, P.; Mercier, M.

    2013-11-01

    The resonant modes of two-dimensional elastic elliptical objects are studied from a modal formalism by emphasizing the role of the symmetries of the objects. More precisely, as the symmetry is broken in the transition from the circular disc to the elliptical one, the splitting up of resonances and level crossings are observed. From the mathematical point of view, this observation can be explained by the broken invariance of the continuous symmetry group { {O}(2)} associated with the circular disc. The elliptical disc is however invariant under the finite group { {C}}_{2v} and the resonances are classified and associated with a given irreducible representation of this group. The main difficulty arises in the application of the group theory in elastodynamics where the vectorial formalism is used to express the physical quantities (elastic displacement and stress) involved in the boundary conditions. However, this method significantly simplifies the numerical treatment of the problem which is uncoupled over the four irreducible representations of { {C} }_{2v}. This provides a full classification of the resonances. They are tagged and tracked as the eccentricity of the elliptical disc increases. Then, the splitting up of resonances, which occurs in the transition from the circular disc to the elliptic one, is emphasized. The computation of displacement normal modes also highlights the mode splittings. A physical interpretation of resonances in terms of geometrical paths is provided.

  11. Large Eddy Simulation of AN Elliptic Jet Injected Into a Supersonic Crossflow

    NASA Astrophysics Data System (ADS)

    Wang, Guo-Lei; Lu, Xi-Yun

    A transverse jet issuing from an elliptic injector into a supersonic crossflow has been investigated using large eddy simulation. The complex flow structures and the relevant flow features are analyzed to exhibit the evolution of shock structures, vertical structures and jet shear layer. A horseshoe vortex is formed in the upstream of the jet and the shock structures exhibit small fluctuations due to the flow interaction. The kidney-shaped counter-rotating vortex pair dominates the flow field in the downstream of the jet. The elliptic jet spreads rapidly in the spanwise direction and then the axis-switching phenomenon occurs. Intense turbulent fluctuations are identified behind the Mach disk because of the large velocity gradients.

  12. Magnetic flux studies in horizontally cooled elliptical superconducting cavities

    SciTech Connect

    Martinello, M. Checchin, M.; Grassellino, A. Crawford, A. C.; Melnychuk, O.; Romanenko, A.; Sergatskov, D. A.

    2015-07-28

    Previous studies on magnetic flux expulsion as a function of cooldown procedures for elliptical superconducting radio frequency (SRF) niobium cavities showed that when the cavity beam axis is placed parallel to the helium cooling flow and sufficiently large thermal gradients are achieved, all magnetic flux could be expelled and very low residual resistance could be achieved. In this paper, we investigate flux trapping for the case of resonators positioned perpendicularly to the helium cooling flow, which is more representative of how SRF cavities are cooled in accelerators and for different directions of the applied magnetic field surrounding the resonator. We show that different field components have a different impact on the surface resistance, and several parameters have to be considered to fully understand the flux dynamics. A newly discovered phenomenon of concentration of flux lines at the cavity top leading to temperature rise at the cavity equator is presented.

  13. Far-infrared emission from dusty ellipticals

    NASA Technical Reports Server (NTRS)

    Walsh, Duncan; Knapp, Jill

    1990-01-01

    The incidence of dust lanes in elliptical galaxies has been estimated at approx. 40 percent by Sadler and Gerhard (1985), although the observed fraction is lower because of inclination effects. A similar percentage of ellipticals has been detected by the Infrared Astronomy Satellite (IRAS) at 100 microns (Knapp et al. 1989); these have far-infrared colors expected for emission from cool dust (S sub 60 micron/S sub 100 micron approx. 1/3). For the far-infrared detected galaxies, neither L sub 100 microns/L sub B nor L sub 60 microns/L sub 100 microns are very dependent on dust content, suggesting that the source of the infrared luminosity is the same in both cases; and hence that dust is responsible even when not detected optically. Despite this indication, L sub 100 microns does not prove to be a good indicator of the quantity of cool interstellar matter in elliptical galaxies, as measured by the mass of neutral hydrogen. There even exist several examples of ellipticals with dust, strong 100 micron flux density and sensitive limits on HI mass (Walsh et al. in preparation). Chief reasons for the lack of correlation include the existence of other important sources of far-IR power in ellipticals, such as nonthermal continuum emission extending from longer wavelengths in flat spectrum radio sources (Golombek, Miley and Neugebauer 1988); and the fact that far-infrared luminosity per unit dust mass is extremely sensitive to the temperature of the ambient radiation field, which is not accurately known. In addition to having their appearance distorted by dust, several ellipticals also show such features as shells, box-shaped isophotes or inner disks. These may be signatures of past mergers, which could also add to the ISM content of the system.

  14. Elliptically polarized bursty radio emissions from Jupiter

    NASA Technical Reports Server (NTRS)

    Reiner, M. J.; Desch, M. D.; Kaiser, M. L.; Manning, R.; Fainberg, J.; Stone, R. G.

    1995-01-01

    We report a new component of Jovian radio emission observed by the Ulysses spacecraft when Ulysses was at high Jovigraphic latitudes (greater than or approximately = 30 deg north or south of the Jovian magnetic equator). This bursty high-latitude emission is elliptically polarized in the right-hand sense when observed from northern latitudes and in the left-hand sense when observed from southern latitudes, consistent with extraordinary mode. The orientation of the polarization ellipse is observed to systematically vary with time relative to the observer. It is argued that the elliptically-polarized nature of the emission is intrinsic to the source region.

  15. Spontaneous motion of an elliptic camphor particle

    NASA Astrophysics Data System (ADS)

    Kitahata, Hiroyuki; Iida, Keita; Nagayama, Masaharu

    2013-01-01

    The coupling between deformation and motion in a self-propelled system has attracted broader interest. In the present study, we consider an elliptic camphor particle for investigating the effect of particle shape on spontaneous motion. It is concluded that the symmetric spatial distribution of camphor molecules at the water surface becomes unstable first in the direction of a short axis, which induces the camphor disk motion in this direction. Experimental results also support the theoretical analysis. From the present results, we suggest that when an elliptic particle supplies surface-active molecules to the water surface, the particle can exhibit translational motion only in the short-axis direction.

  16. Buckling of elliptical rings under uniform external pressure

    SciTech Connect

    Tang, Y.

    1991-04-03

    A thin, elastic elliptical ring is subjected to uniform external pressure. The lowest critical pressure is computed and presented for various ratio of the major axis to the minor axis of the elliptical ring. It is found that the critical pressure for an elliptical ring is higher than that for the circular ring whose diameter is equal to the major axis of the elliptical ring. It can be shown that under the same external pressure, the axial force developed in the elliptical ring is less than that developed in the corresponding circular ring. Thus, a higher pressure is required to buckle the elliptical rings. Therefore, by changing the shape of the ring from circular to elliptical, the capability of the ring to sustain the external pressure can be increased substantially. The results of this study can be useful in the design of elliptical reinforcing rings and thin-walled tubes subjected to external pressure.

  17. How Does Abundance Affect the Strength of UV Emission in Elliptical Galaxies?

    NASA Technical Reports Server (NTRS)

    Sonneborn, George (Technical Monitor); Brown, Thomas

    2005-01-01

    This program used the Far Ultraviolet Spectroscopic Explorer (FUSE) to observe elliptical galaxies with the intention of measuring the chemical abundances in their hot stellar populations. It was designed to complement an earlier FUSE program that observed elliptical galaxies with strong UV emission. The current program originally planned observations of two ellipticals with weak UV emission (M32 and M49). Once FUSE encountered pointing control problems in certain regions of the sky (particularly Virgo, which is very unfortunate for the study of ellipticals in general), M49 was replaced with the bulge of M31, which has a similar UV-to-optical flux ratio as the center of M49. As the closest elliptical galaxy and the one with the weakest UV-to-optical flux ratio, M32 was an obvious choice of target, but M49 was the ideal complementary target, because it has a very low reddening (unlike M32). With the inability of FUSE to point at Virgo, nearly all of the best elliptical galaxies (bright galaxies with low foreground extinction) were also lost, and this severely hampered three FUSE programs of the PI, all focused on the hot stellar populations of ellipticals. M31 was the best replacement for M49, but like M32, it suffers from significant foreground reddening. Strong Galactic ISM lines heavily contaminate the FUSE spectra of M31 and M32. These ISM lines are coincident with the photospheric lines from the stellar populations (whereas M49, with little foreground ISM and significant redshift, would not have suffered from this problem). We have reduced the faint (and thus difficult) data for M31 and M32, producing final co-added spectra representing all of the exposures, but we have not yet finished our analysis, due to the complication of the contaminating ISM. The silver lining here is the set of CHI lines at 1175 Angstroms, which are not significantly contaminated by the ISM. A comparison of the M31 spectrum with other galaxies observed by FEE showed a surprising result

  18. Elliptic genera from multi-centers

    NASA Astrophysics Data System (ADS)

    Gaddam, Nava

    2016-05-01

    I show how elliptic genera for various Calabi-Yau threefolds may be understood from supergravity localization using the quantization of the phase space of certain multi-center configurations. I present a simple procedure that allows for the enumeration of all multi-center configurations contributing to the polar sector of the elliptic genera — explicitly verifying this in the cases of the quintic in {P} 4, the sextic in {W}{P} (2,1,1,1,1), the octic in {W}{P} (4,1,1,1,1) and the dectic in {W}{P} (5,2,1,1,1). With an input of the corresponding `single-center' indices (Donaldson-Thomas invariants), the polar terms have been known to determine the elliptic genera completely. I argue that this multi-center approach to the low-lying spectrum of the elliptic genera is a stepping stone towards an understanding of the exact microscopic states that contribute to supersymmetric single center black hole entropy in {N} = 2 supergravity.

  19. Body tides on an elliptical rotating earth

    NASA Technical Reports Server (NTRS)

    Wahr, J. M.

    1978-01-01

    The complete tidal response of an elliptical, rotating, elastic Earth is found to contain small displacements which do not fit into the conventional Love number framework. Corresponding observable tidal quantities (gravity, tilt, strain, Eulerian potential, etc.) are modified by the addition of small latitude dependent terms.

  20. Transverse Mercator Projection Via Elliptic Integrals

    NASA Technical Reports Server (NTRS)

    Wallis, David E.

    1992-01-01

    Improved method of construction of U.S. Army's universal transverse Mercator grid system based on Gauss-Kruger transverse Mercator projection and on use of elliptic integrals of second kind. Method can be used to map entire northern or southern hemisphere with respect to single principal meridian.

  1. On the rotation of elliptical galaxies

    NASA Technical Reports Server (NTRS)

    Binney, J.

    1978-01-01

    The tensor virial theorem is applied to models of early-type galaxies. First the theorem is applied to rotating elliptical galaxies whose constant-density surfaces are similar ellipsoids. A relationship is obtained between the observed rotations and the forms of generally triaxial galaxies. By applying the results of Robert (1962) to the evaluation of the components of the Chandrasekhar tensor which occurs in this relationship, it is found that the form of a galaxy that lacks global velocity anisotropy uniquely determines the ratio of its rotational and random kinetic energies independently of the radial density profile of that galaxy. A distribution of three-dimensional prolate spheroids is derived which accounts for the observed distribution of ellipticities reported by Sandage, Freeman, and Stokes (1970). This is then used to derive curves giving the expected frequency of occurrence of galaxies of given rotational velocities for each of a number of different apparent elongations on the sky. It is found that if elliptical galaxies are prolate, there should be little correlation between apparent ellipticity and rotation velocity.

  2. Application of rectangular and elliptical dielcore feed horns to elliptical reflector antennas

    NASA Astrophysics Data System (ADS)

    Lier, Erik; Rahmat-Samii, Yahya; Rengarajan, Sembiam R.

    1991-11-01

    The pattern characteristics of elliptical reflector antennas are investigated when they are fed by rectangular and elliptical horns partially filled with a dielectric. The bandwidth characteristics of these dielcore horns are superior to those of their corrugated horn counterparts. Representative reflector patterns are computed to properly demonstrate the utility of these feeds for reflector antennas with elliptical apertures. This reflector antenna exhibits high efficiency and low cross polarization, and may be suitable for radar and satellite antenna applications. The antenna configuration may become useful in relatively small antennas where more than 10 percent cross-polar bandwidth is required. The efficient dielcore horns may also be used as feeds for elliptical nonshaped dual-reflector antennas.

  3. Aspect ratio effect on shock-accelerated elliptic gas cylinders

    NASA Astrophysics Data System (ADS)

    Zou, Liyong; Liao, Shenfei; Liu, Cangli; Wang, Yanping; Zhai, Zhigang

    2016-03-01

    The evolution of an elliptic heavy-gas (SF6) cylinder accelerated by a planar weak shock wave is investigated experimentally using particle image velocimetry (PIV) diagnostics, and the emphasis is on the aspect ratio effect on shock-elliptic cylinder interaction. Experiments are conducted at five different aspect ratios (the ratio of length in streamwise and spanwise directions) varied from 0.25 to 4.0. PIV raw images and quantitative flow field data are obtained at t = 0.6 ms after the shock impact. As the aspect ratio increases, the interface morphology develops faster owing to more vorticity produced along the interface and smaller vortex spacing between the two vortex cores. For each case in this study, the maximal fluctuating velocity locates at the middle point of the two counter-vortices. The histograms of fluctuating velocity reveal that a distinct double-peak structure appears in the largest aspect ratio case in comparison with a single-peak structure in the smallest aspect ratio case. The vortex velocities predicted by the theoretical model [G. Rudinger and L. M. Somers, "Behaviour of small regions of different gases carried in accelerated gas flows," J. Fluid Mech. 7, 161-176 (1960)] agree well with the experimental ones. With the increase of aspect ratio, the maximal value of vorticity increases as well as the circulation, and more low-magnitude quantities are generated, which indicates the formation of multi-scale flow structure in the late mixing process. It is found that the experimental circulation of the vortex motion is reasonably estimated by the ideal point vortex-pair model.

  4. Performances study of UWB monopole antennas using half-elliptic radiator conformed on elliptical surface

    NASA Astrophysics Data System (ADS)

    Djidel, S.; Bouamar, M.; Khedrouche, D.

    2016-04-01

    This paper presents a performances study of UWB monopole antenna using half-elliptic radiator conformed on elliptical surface. The proposed antenna, simulated using microwave studio computer CST and High frequency simulator structure HFSS, is designed to operate in frequency interval over 3.1 to 40 GHz. Good return loss and radiation pattern characteristics are obtained in the frequency band of interest. The proposed antenna structure is suitable for ultra-wideband applications, which is, required for many wearable electronics applications.

  5. Data processing of absorption spectra from photoionized plasma experiments at Za)

    NASA Astrophysics Data System (ADS)

    Hall, I. M.; Durmaz, T.; Mancini, R. C.; Bailey, J. E.; Rochau, G. A.

    2010-10-01

    We discuss the processing of x-ray absorption spectra from photoionized plasma experiments at Z. The data was recorded with an imaging spectrometer equipped with two elliptically bent potassium acid phthalate (KAP) crystals. Both time-integrated and time-resolved data were recorded. In both cases, the goal is to obtain the transmission spectra for quantitative analysis of plasma conditions.

  6. The Ellipticity Distribution of Ambiguously Blended Objects

    NASA Astrophysics Data System (ADS)

    Dawson, William A.; Schneider, Michael D.; Tyson, J. Anthony; Jee, M. James

    2016-01-01

    Using overlapping fields with space-based Hubble Space Telescope and ground-based Subaru Telescope imaging we identify a population of blended galaxies that are blended to such a large degree that they are detected as single objects in the ground-based monochromatic imaging, which we label “ambiguous blends.” For deep imaging data, such as the depth targeted with the Large Synoptic Survey Telescope (LSST), the ambiguous blend population is both large (∼14%) and has a distribution of ellipticities that is different from that of unblended objects in a way that will likely be important for weak lensing measurements. Most notably, for a limiting magnitude of i ∼ 27 we find that ambiguous blending results in a ∼14% increase in shear noise (or an ∼12% decrease in the effective projected number density of lensed galaxies; neff) due to (1) larger intrinsic ellipticity dispersion, and (2) a scaling with the galaxy number density Ngal that is shallower than 1/\\sqrt{{N}{gal}}. For the LSST Gold Sample (i < 25.3) there is a ∼7% increase in shear noise (or ∼7% decrease in neff). More importantly than these increases in the shear noise, we find that the ellipticity distribution of ambiguous blends has an rms that is 13% larger than that of non-blended galaxies. Given the need of future weak lensing surveys to constrain the ellipticity distribution of galaxies to better than a percent in order to mitigate cosmic shear multiplicative biases, if it is unaccounted for, the different ellipticity distribution of ambiguous blends could be a dominant systematic.

  7. Elliptic Genus of Phases of N = 2 Theories

    NASA Astrophysics Data System (ADS)

    Libgober, Anatoly

    2015-12-01

    We discuss an algebro-geometric description of Witten's phases of N = 2 theories and propose a definition of their elliptic genus provided some conditions on singularities of the phases are met. For Landau-Ginzburg phase one recovers elliptic genus of LG models proposed in physics literature in early 1990s. For certain transitions between phases we derive invariance of elliptic genus from an equivariant form of McKay correspondence for elliptic genus. As special cases one obtains Landau-Giznburg/Calabi-Yau correspondence for elliptic genus of weighted homogeneous potentials as well as certain hybrid/CY correspondences.

  8. Multilevel elliptic smoothing of large three-dimensional grids

    NASA Technical Reports Server (NTRS)

    Mastin, C. Wayne

    1995-01-01

    Elliptic grid generation methods have been used for many years to smooth and improve grids generated by algebraic interpolation schemes. However, the elliptic system that must be solved is nonlinear and convergence is generally very slow for large grids. In an attempt to make elliptic methods practical for large three-dimensional grids, a two-stage implementation is developed where the overall grid point locations are set using a coarse grid generated by the elliptic system. The coarse grid is then interpolated to generate a finer grid which is smoothed using only a few iterations of the elliptic system.

  9. Jacobi-Bessel Analysis Of Antennas With Elliptical Apertures.

    NASA Technical Reports Server (NTRS)

    Rahmat-Samii, Y.

    1989-01-01

    Coordinate transformation improves convergence pattern analysis of elliptical-aperture antennas. Modified version of Jacobi-Bessel expansion for vector diffraction analysis of reflector antennas uses coordinate transformation to improve convergence with elliptical apertures. Expansion converges rapidly for antennas with circular apertures, but less rapidly for elliptical apertures. Difference in convergence behavior between circular and elliptical Jacobi-Bessel algorithms indicated by highest values of indices m, n, and p required to achieve same accuracy in computed radiation pattern of offset paraboloidal antenna with elliptical aperture.

  10. Dark matter deprivation in the field elliptical galaxy NGC 7507

    NASA Astrophysics Data System (ADS)

    Lane, Richard R.; Salinas, Ricardo; Richtler, Tom

    2015-02-01

    Context. Previous studies have shown that the kinematics of the field elliptical galaxy NGC 7507 do not necessarily require dark matter. This is troubling because, in the context of ΛCDM cosmologies, all galaxies should have a large dark matter component. Aims: Our aims are to determine the rotation and velocity dispersion profile out to larger radii than do previous studies, and, therefore, more accurately estimate of the dark matter content of the galaxy. Methods: We use penalised pixel-fitting software to extract velocities and velocity dispersions from GMOS slit mask spectra. Using Jeans and MONDian modelling, we then produce models with the goal of fitting the velocity dispersion data. Results: NGC 7507 has a two-component stellar halo, with the outer halo counter rotating with respect to the inner halo, with a kinematic boundary at a radius of ~110'' (~12.4 kpc). The velocity dispersion profile exhibits an increase at ~70'' (~7.9 kpc), reminiscent of several other elliptical galaxies. Our best fit models are those under mild anisotropy, which include ~100 times less dark matter than predicted by ΛCDM, although mildly anisotropic models that are completely dark matter free fit the measured dynamics almost equally well. Our MONDian models, both isotropic and anisotropic, systematically fail to reproduce the measured velocity dispersions at almost all radii. Conclusions: The counter-rotating outer halo implies a merger remnant, as does the increase in velocity dispersion at ~70''. From simulations it seems plausible that the merger that caused the increase in velocity dispersion was a spiral-spiral merger. Our Jeans models are completely consistent with a no dark matter scenario, however, some dark matter can be accommodated, although at much lower concentrations than predicted by ΛCDM simulations. This indicates that NGC 7507 may be a dark matter free elliptical galaxy. Regardless of whether NGC 7507 is completely dark matter free or very dark matter poor

  11. Blue star-forming isolated elliptical galaxies

    NASA Astrophysics Data System (ADS)

    Lacerna, I.; Hernández-Toledo, H. M.; Avila-Reese, V.; Abonza-Sane, J.; del Olmo, A.

    2016-06-01

    The isolated environment seems to favor the formation of blue, star-forming galaxies that are not observed in a high-density environment such as the Coma supercluster. These galaxies, with masses between 7 × 10^9 and 2 × 10^10 h‑2 Msun, are also the youngest galaxies from a sample of isolated elliptical galaxies with light-weighted stellar ages ˜1 < Gyr and exhibit bluer colors toward the galaxy center. Around 30-60% of their present-day luminosity, but only <5% of their present-day mass, is due to star formation in the last 1 Gyr. The color and star-formation activity in these galaxies could be explained by rejuvenation of ellipticals by recent (<1 Gyr) cold gas accretion.

  12. Modelling elliptically polarised free electron lasers

    NASA Astrophysics Data System (ADS)

    Henderson, J. R.; Campbell, L. T.; Freund, H. P.; McNeil, B. W. J.

    2016-06-01

    A model of a free electron laser (FEL) operating with an elliptically polarised undulator is presented. The equations describing the FEL interaction, including resonant harmonic radiation fields, are averaged over an undulator period and generate a generalised Bessel function scaling factor, similar to that of planar undulator FEL theory. Comparison between simulations of the averaged model with those of an unaveraged model show very good agreement in the linear regime. Two unexpected results were found. Firstly, an increased coupling to harmonics for elliptical rather than planar polarisarised undulators. Secondly, and thought to be unrelated to the undulator polarisation, a significantly different evolution between the averaged and unaveraged simulations of the harmonic radiation evolution approaching FEL saturation.

  13. MIB Galerkin method for elliptic interface problems.

    PubMed

    Xia, Kelin; Zhan, Meng; Wei, Guo-Wei

    2014-12-15

    Material interfaces are omnipresent in the real-world structures and devices. Mathematical modeling of material interfaces often leads to elliptic partial differential equations (PDEs) with discontinuous coefficients and singular sources, which are commonly called elliptic interface problems. The development of high-order numerical schemes for elliptic interface problems has become a well defined field in applied and computational mathematics and attracted much attention in the past decades. Despite of significant advances, challenges remain in the construction of high-order schemes for nonsmooth interfaces, i.e., interfaces with geometric singularities, such as tips, cusps and sharp edges. The challenge of geometric singularities is amplified when they are associated with low solution regularities, e.g., tip-geometry effects in many fields. The present work introduces a matched interface and boundary (MIB) Galerkin method for solving two-dimensional (2D) elliptic PDEs with complex interfaces, geometric singularities and low solution regularities. The Cartesian grid based triangular elements are employed to avoid the time consuming mesh generation procedure. Consequently, the interface cuts through elements. To ensure the continuity of classic basis functions across the interface, two sets of overlapping elements, called MIB elements, are defined near the interface. As a result, differentiation can be computed near the interface as if there is no interface. Interpolation functions are constructed on MIB element spaces to smoothly extend function values across the interface. A set of lowest order interface jump conditions is enforced on the interface, which in turn, determines the interpolation functions. The performance of the proposed MIB Galerkin finite element method is validated by numerical experiments with a wide range of interface geometries, geometric singularities, low regularity solutions and grid resolutions. Extensive numerical studies confirm the

  14. THE STELLAR HALOS OF MASSIVE ELLIPTICAL GALAXIES

    SciTech Connect

    Greene, Jenny E.; Murphy, Jeremy D.; Comerford, Julia M.; Gebhardt, Karl; Adams, Joshua J.

    2012-05-01

    We use the Mitchell Spectrograph (formerly VIRUS-P) on the McDonald Observatory 2.7 m Harlan J. Smith Telescope to search for the chemical signatures of massive elliptical galaxy assembly. The Mitchell Spectrograph is an integral-field spectrograph with a uniquely wide field of view (107'' Multiplication-Sign 107''), allowing us to achieve remarkably high signal-to-noise ratios of {approx}20-70 pixel{sup -1} in radial bins of 2-2.5 times the effective radii of the eight galaxies in our sample. Focusing on a sample of massive elliptical galaxies with stellar velocity dispersions {sigma}{sub *} > 150 km s{sup -1}, we study the radial dependence in the equivalent widths (EW) of key metal absorption lines. By twice the effective radius, the Mgb EWs have dropped by {approx}50%, and only a weak correlation between {sigma}{sub *} and Mgb EW remains. The Mgb EWs at large radii are comparable to those seen in the centers of elliptical galaxies that are {approx} an order of magnitude less massive. We find that the well-known metallicity gradients often observed within an effective radius continue smoothly to 2.5 R{sub e} , while the abundance ratio gradients remain flat. Much like the halo of the Milky Way, the stellar halos of our galaxies have low metallicities and high {alpha}-abundance ratios, as expected for very old stars formed in small stellar systems. Our observations support a picture in which the outer parts of massive elliptical galaxies are built by the accretion of much smaller systems whose star formation history was truncated at early times.

  15. A Jacobian elliptic single-field inflation

    NASA Astrophysics Data System (ADS)

    Villanueva, J. R.; Gallo, Emanuel

    2015-06-01

    In the scenario of single-field inflation, this field is described in terms of Jacobian elliptic functions. This approach provides, when constrained to particular cases, analytic solutions already known in the past, generalizing them to a bigger family of analytical solutions. The emergent cosmology is analyzed using the Hamilton-Jacobi approach and then the main results are contrasted with the recent measurements obtained from the Planck 2015 data.

  16. Fluxon Dynamics in Elliptic Annular Josephson Junctions

    NASA Astrophysics Data System (ADS)

    Monaco, Roberto; Mygind, Jesper

    2016-04-01

    We analyze the dynamics of a magnetic flux quantum (current vortex) trapped in a current-biased long planar elliptic annular Josephson tunnel junction. The system is modeled by a perturbed sine-Gordon equation that determines the spatial and temporal behavior of the phase difference across the tunnel barrier separating the two superconducting electrodes. In the absence of an external magnetic field, the fluxon dynamics in an elliptic annulus does not differ from that of a circular annulus where the stationary fluxon speed merely is determined by the system losses. The interaction between the vortex magnetic moment and a spatially homogeneous in-plane magnetic field gives rise to a tunable periodic non-sinusoidal potential which is strongly dependent on the annulus aspect ratio. We study the escape of the vortex from a well in the tilted potential when the bias current exceeds the depinning current. The smallest depinning current as well as the lowest sensitivity of the annulus to the external field is achieved when the axes ratio is equal to √{2}. The presented extensive numerical results are in good agreement with the findings of the perturbative approach. We also probe the rectifying properties of an asymmetric potential implemented with an egg-shaped annulus formed by two semi-elliptic arcs.

  17. Elliptic Solvers for Adaptive Mesh Refinement Grids

    SciTech Connect

    Quinlan, D.J.; Dendy, J.E., Jr.; Shapira, Y.

    1999-06-03

    We are developing multigrid methods that will efficiently solve elliptic problems with anisotropic and discontinuous coefficients on adaptive grids. The final product will be a library that provides for the simplified solution of such problems. This library will directly benefit the efforts of other Laboratory groups. The focus of this work is research on serial and parallel elliptic algorithms and the inclusion of our black-box multigrid techniques into this new setting. The approach applies the Los Alamos object-oriented class libraries that greatly simplify the development of serial and parallel adaptive mesh refinement applications. In the final year of this LDRD, we focused on putting the software together; in particular we completed the final AMR++ library, we wrote tutorials and manuals, and we built example applications. We implemented the Fast Adaptive Composite Grid method as the principal elliptic solver. We presented results at the Overset Grid Conference and other more AMR specific conferences. We worked on optimization of serial and parallel performance and published several papers on the details of this work. Performance remains an important issue and is the subject of continuing research work.

  18. The elliptic model for communication fluxes

    NASA Astrophysics Data System (ADS)

    Herrera-Yagüe, C.; Schneider, C. M.; Smoreda, Z.; Couronné, T.; Zufiria, P. J.; González, M. C.

    2014-04-01

    In this paper, a model (called the elliptic model) is proposed to estimate the number of social ties between two locations using population data in a similar manner to how transportation research deals with trips. To overcome the asymmetry of transportation models, the new model considers that the number of relationships between two locations is inversely proportional to the population in the ellipse whose foci are in these two locations. The elliptic model is evaluated by considering the anonymous communications patterns of 25 million users from three different countries, where a location has been assigned to each user based on their most used phone tower or billing zip code. With this information, spatial social networks are built at three levels of resolution: tower, city and region for each of the three countries. The elliptic model achieves a similar performance when predicting communication fluxes as transportation models do when predicting trips. This shows that human relationships are influenced at least as much by geography as is human mobility.

  19. Modeling near wall effects in second moment closures by elliptic relaxation

    NASA Technical Reports Server (NTRS)

    Laurence, D.; Durbin, P.

    1994-01-01

    The elliptic relaxation model of Durbin (1993) for modeling near-wall turbulence using second moment closures (SMC) is compared to DNS data for a channel flow at Re(sub t) = 395. The agreement for second order statistics and even the terms in their balance equation is quite satisfactory, confirming that very little viscous effects (via Kolmogoroff scales) need to be added to the high Reynolds versions of SMC for near-wall-turbulence. The essential near-wall feature is thus the kinematic blocking effect that a solid wall exerts on the turbulence through the fluctuating pressure, which is best modeled by an elliptic operator. Above the transition layer, the effect of the original elliptic operator decays rapidly, and it is suggested that the log-layer is better reproduced by adding a non-homogeneous reduction of the return to isotropy, the gradient of the turbulent length scale being used as a measure of the inhomogeneity of the log-layer. The elliptic operator was quite easily applied to the non-linear Craft & Launder pressure-strain model yielding an improved distinction between the spanwise and wall normal stresses, although at higher Reynolds number (Re) and away from the wall, the streamwise component is severely underpredicted, as well as the transition in the mean velocity from the log to the wake profiles. In this area a significant change of behavior was observed in the DNS pressure-strain term, entirely ignored in the models.

  20. Cool infalling gas and its interaction with the hot ISM of elliptical galaxies

    NASA Technical Reports Server (NTRS)

    Sparks, W. B.; Macchetto, F. D.

    1990-01-01

    The authors describe work leading to the suggestion that interaction between infalling cool gas and ambient hot, coronal plasma in elliptical galaxies is responsible for emission filaments, and might remove the need for large mass depositions in cooling flows. A test of the hypothesis is undertaken - the run of surface brightness with radius for the emission lines - and the prediction agrees well with the data.

  1. Cloaking of single and multiple elliptical cylinders and strips with confocal elliptical nanostructured graphene metasurface.

    PubMed

    Bernety, Hossein M; Yakovlev, Alexander B

    2015-05-13

    In this paper, we present a novel analytical approach for cloaking of dielectric and metallic elliptical cylinders with a graphene monolayer and a nanostructured graphene metasurface at low-terahertz frequencies. The analytical approach is based on the solution of the electromagnetic scattering problem in terms of elliptical waves represented by the radial and angular even and odd Mathieu functions, with the use of sheet impedance boundary conditions at the metasurface. It is shown that scattering cancellation occurs for all incident and observation angles. A special case concerns cloaking of a 2D metallic strip represented by a degenerated ellipse, wherein the focal points of the cloak metasurface correspond to the edges of the strip. The analytical approach has been extended in order to cloak a cluster of elliptical objects for different cases of closely spaced, merging, and overlapping configurations. The results obtained by our analytical approach are validated with full-wave numerical simulations. PMID:25894518

  2. X-RAY ISOPHOTES IN A RAPIDLY ROTATING ELLIPTICAL GALAXY: EVIDENCE OF INFLOWING GAS

    SciTech Connect

    Brighenti, Fabrizio; Mathews, William G.

    2009-11-10

    We describe two-dimensional gasdynamical computations of the X-ray emitting gas in the rotating elliptical galaxy NGC 4649 that indicate an inflow of approx1 M{sub sun} yr{sup -1} at every radius. Such a large instantaneous inflow cannot have persisted over a Hubble time. The central constant-entropy temperature peak recently observed in the innermost 150 pc is explained by compressive heating as gas flows toward the central massive black hole. Since the cooling time of this gas is only a few million years, NGC 4649 provides the most acutely concentrated known example of the cooling flow problem in which the time-integrated apparent mass that has flowed into the galactic core exceeds the total mass observed there. This paradox can be resolved by intermittent outflows of energy or mass driven by accretion energy released near the black hole. Inflowing gas is also required at intermediate kpc radii to explain the ellipticity of X-ray isophotes due to spin-up by mass ejected by stars that rotate with the galaxy and to explain local density and temperature profiles. We provide evidence that many luminous elliptical galaxies undergo similar inflow spin-up. A small turbulent viscosity is required in NGC 4649 to avoid forming large X-ray luminous disks that are not observed, but the turbulent pressure is small and does not interfere with mass determinations that assume hydrostatic equilibrium.

  3. Quantifying the Age Spectra of Particulate Organic Carbon in the Lower Mississippi River and Atchafalaya Outflow during the Great Flood of 2011 - How Does a High-Flow Event Effect Carbon Transport?

    NASA Astrophysics Data System (ADS)

    Rosenheim, B. E.; Roberts, B. J.; Allison, M. A.

    2011-12-01

    Biogeochemically, the role of rivers in transporting carbon to long-term sedimentary reservoirs is important to regulating atmospheric CO2 on several geologic time scales. Physically, sediment transport processes link carbon transport and depositional potential at different flow regimes. In the deltaic depositional setting, both types of processes dictate what carbon is stored, what is transported through the system, and what is reconverted to atmospheric CO2. To constrain first order relationships between sediment processes, biogeochemistry, and age spectra of transported carbon, we employ ramped pyrolysis radiocarbon analysis to samples taken in conjunction with bedload and suspended sediment surveys in the Mississippi River and with bioavailability data from the Atchafalaya River. Samples of particulate organic carbon (POC) were filtered from the Mississippi River and Atchafalaya outflow during the rising limb, crest, and falling limb of the 2011 Great Flood event. These samples were analyzed by ramped pyrolysis radiocarbon determination, whereby different temperature intervals of the bulk POC are pyrolyzed, collected, and measured for radiocarbon content. Past sampling of different flow regimes have shown older carbon being transported by both rivers during higher flow events, as well as increasing age of POC toward both river outflows. Deltaic deposits are constructed largely from high flow events, thus previous data indicate an attenuation of young carbon storage in such deposits with progressively larger flow events. Data from these samples will be compared to past sampled flow regimes to further assess the relationship between flow regime and age spectrum of POC. Ramped pyrolysis data from the Mississippi River will be compared to bedload and suspended sediment transport, and data from the Atchafalaya will be compared to bioavailability data from both the water column and the underlying sediments. These approaches will provide information about the

  4. Storm Spectra

    NASA Technical Reports Server (NTRS)

    2007-01-01

    portion is defined by the day/night boundary (known as the terminator).

    These two images illustrate only a small fraction of the information contained in a single LEISA scan, highlighting just one aspect of the power of infrared spectra for atmospheric studies.

  5. Approximate factorization with an elliptic pressure solver for incompressible flow

    NASA Technical Reports Server (NTRS)

    Bernard, R. S.; Thompson, J. F.

    1982-01-01

    Two-dimensional curvilinear coordinates are used to solve the incompressible Navier-Stokes equations, in conjunction with approximate factorization for the solution of the momentum equation and the successive overrelaxation by lines method for the solution of a Poisson equation for the pressure. The combined algorithm, although not fully explicit, is marginally stable at Reynolds numbers lower than 10,000 and time increments of 0.01. Pressure distributions calculated for attack angles of zero and 6 deg are of the same shape as the experimental curves, but are shifted to one side.

  6. Numerical calculations of flow fields

    NASA Technical Reports Server (NTRS)

    Anderson, D. M.; Vogel, J. M.

    1972-01-01

    The solutions to the equations of motion for inviscid fluid flow around a pointed elliptic cone at incidence are presented. The numerical method used, MacCormack's second order preferential predictor-corrector finite difference approximation, is applied to the fluid flow equations derived in conservation-law form. The entropy boundary condition, hitherto unused for elliptic cone problems, is investigated and compared to reflection boundary condition solutions. The stagnation streamline movement of the inclined elliptic cone is noted and surface pressure coefficients are plotted. Also presented are solutions for an elliptic cone and a circular cone at zero incidence and a circular cone at a small angle of attack. Comparisons are made between these present solutions and previously published theory.

  7. Magnetic design of the advanced light source elliptical wiggler

    SciTech Connect

    Marks, S.; Akre, J.; Hoyer, E.; Humphries, D.; Jackson, T.; Minamihara, Y.; Pipersky, P.; Plate, D.; Schlueter, R.

    1995-06-01

    An elliptical wiggler has been designed for installation in the Advanced Light Source at the Lawrence Berkeley Laboratory. The design has been optimized for the production of circularly polarized light in the 50 eV to 10 KeV energy range. The device will be 3.4 m long consisting of vertical and horizontal periodic structures. The period length for both is 20 cm. The vertical structure is a hybrid permanent magnet design which produces a peak field of 2.0 T. The horizontal magnetic structure is an iron core electromagnetic design shifted longitudinally by one-quarter period relative to the vertical structure; it has a peak field of 0.095 T. The polarity of the horizontal field can be switched at a rate of up to 1 Hz, which results in a modulation of the chirality of the circularly polarized radiation on-axis. This paper discusses the magnetic design and presents the results of radiation spectra calculations used for determining optimal field parameter settings.

  8. Evolution of Hot Gas in Elliptical Galaxies

    NASA Technical Reports Server (NTRS)

    Mathews, William G.

    2004-01-01

    This theory grant was awarded to study the curious nature, origin and evolution of hot gas in elliptical galaxies and their surrounding groups. Understanding the properties of this X-ray emitting gas has profound implications over the broad landscape of modern astrophysics: cosmology, galaxy formation, star formation, cosmic metal enrichment, galactic structure and dynamics, and the physics of hot gases containing dust and magnetic fields. One of our principal specific objectives was to interpret the marvelous new observations from the XMM and Chandru satellite X-ray telescopes.

  9. Liouville field, modular forms and elliptic genera

    NASA Astrophysics Data System (ADS)

    Eguchi, Tohru; Sugawara, Yuji; Taormina, Anne

    2007-03-01

    When we describe non-compact or singular Calabi-Yau manifolds by CFT, continuous as well as discrete representations appear in the theory. These representations mix in an intricate way under the modular transformations. In this article, we propose a method of combining discrete and continuous representations so that the resulting combinations have a simpler modular behavior and can be used as conformal blocks of the theory. We compute elliptic genera of ALE spaces and obtain results which agree with those suggested from the decompactification of K3 surface. Consistency of our approach is assured by some remarkable identity of theta functions whose proof, by D. Zagier, is included in an appendix.

  10. Life and Times of the X-Ray Gas in Elliptical Galaxies

    NASA Astrophysics Data System (ADS)

    Renzini, Alvio

    2000-09-01

    The global gas flows in elliptical galaxies are initiated by stellar mass loss and their diagnostics rely on X-ray observations. The flows are controlled by a number of factors, including supernova heating, the depth and shape of the potential well as determined by the amount and distribution of bright and dark matter, AGN fueling and its feedback effects, interaction with the intracluster medium, and star formation. As a result no steady-state solution can satisfactorily describe the complex, evolutionary behavior of the gas flows, which can experience supersonic wind, subsonic outflow, and inflow phases, and transitions between one such flow regime to another. Having identified heating by Type Ia SN's as one of the key factors controlling the flows, constraints on its evolution with cosmological time are derived by considering the total amount of iron contained in whole clusters of galaxies, while the iron abundance in individual galaxy flows can set constraints on the present rate of SNIa's in ellipticals. The central issue of the problem remains the fate of the gas. It is argued that in one way or another, via SN-driven winds, ram pressure stripping, or AGN violent ejection, most of the gas is ultimately expelled from galaxies thus joining the intracluster medium.

  11. Modeling spatially and spectrally resolved observations to diagnose the formation of elliptical galaxies

    NASA Astrophysics Data System (ADS)

    Snyder, Gregory Frantz

    2013-03-01

    In extragalactic astronomy, a central challenge is that we cannot directly watch what happens to galaxies before and after they are observed. This dissertation focuses on linking predictions of galaxy time-evolution directly with observations, evaluating how interactions, mergers, and other processes affect the appearance of elliptical galaxies. The primary approach is to combine hydrodynamical simulations of galaxy formation, including all major components, with dust radiative transfer to predict their observational signatures The current paradigm implies that a quiescent elliptical emerges following a formative starburst event. These trigger accretion onto the central supermassive black hole (SMBH), which then radiates as an active galactic nucleus (AGN). However, it is not clear the extent to which SMBH growth is fueled by these events nor how important is their energy input at setting the appearance of the remnant. This thesis presents results drawing from three phases in the formation of a typical elliptical: 1) I evaluate how to disentangle AGN from star formation signatures in mid-infrared spectra during a dust-enshrouded starburst, making testable predictions for robustly tracing SMBH growth with the James Webb Space Telescope; 2) I develop a model for the rate of merger-induced post-starburst galaxies selected from optical spectra, resolving tension between their observed rarity and merger rates from other estimates; and 3) I present results from Hubble Space Telescope imaging of elliptical galaxies in galaxy clusters at 1 < z < 2, the precursors of present-day massive clusters with M ~ 1015 solar masses, demonstrating that their stars formed over an extended period and ruling out the simplest model for their formation history. These results lend support to a stochastic formation history for ellipticals driven by mergers or interactions. However, significant uncertainties remain in how to evaluate the implications of galaxy appearance, in particular their

  12. A study of thin liquid sheet flows

    NASA Technical Reports Server (NTRS)

    Chubb, Donald L.; Calfo, Frederick D.; Mcconley, Marc W.; Mcmaster, Matthew S.; Afjeh, Abdollah A.

    1993-01-01

    This study was a theoretical and experimental investigation of thin liquid sheet flows in vacuum. A sheet flow created by a narrow slit of width, W, coalesces to a point at a distance, L, as a result of surface tension forces acting at the sheet edges. As the flow coalesces, the fluid accumulates in the sheet edges. The observed triangular shape of the sheet agrees with the calculated triangular result. Experimental results for L/W as a function of Weber number, We, agree with the calculated result, L/W = the sq. root of 8We. The edge cross sectional shape is found to oscillate from elliptic to 'cigar' like to 'peanut' like and then back to elliptic in the flow direction. A theoretical one-dimensional model was developed that yielded only elliptic solutions for the edge cross section. At the points where the elliptic shapes occur, there is agreement between theory and experiment.

  13. Aerodynamic Comparison of Hyper-Elliptic Cambered Span (HECS) Wings with Conventional Configurations

    NASA Technical Reports Server (NTRS)

    Lazos, Barry S.; Visser, Kenneth D.

    2006-01-01

    An experimental study was conducted to examine the aerodynamic and flow field characteristics of hyper-elliptic cambered span (HECS) wings and compare results with more conventional configurations used for induced drag reduction. Previous preliminary studies, indicating improved L/D characteristics when compared to an elliptical planform prompted this more detailed experimental investigation. Balance data were acquired on a series of swept and un-swept HECS wings, a baseline elliptic planform, two winglet designs and a raked tip configuration. Seven-hole probe wake surveys were also conducted downstream of a number of the configurations. Wind tunnel results indicated aerodynamic performance levels of all but one of the HECS wings exceeded that of the other configurations. The flow field data surveys indicate the HECS configurations displaced the tip vortex farther outboard of the wing than the Baseline configuration. Minimum drag was observed on the raked tip configuration and it was noted that the winglet wake lacked the cohesive vortex structure present in the wakes of the other configurations.

  14. Linear instability in the wake of an elliptic wing

    NASA Astrophysics Data System (ADS)

    He, Wei; Tendero, Juan Ángel; Paredes, Pedro; Theofilis, Vassilis

    2016-07-01

    Linear global instability analysis has been performed in the wake of a low aspect ratio three-dimensional wing of elliptic cross section, constructed with appropriately scaled Eppler E387 airfoils. The flow field over the airfoil and in its wake has been computed by full three-dimensional direct numerical simulation at a chord Reynolds number of Rec=1750 and two angles of attack, {AoA}=0° and 5°. Point-vortex methods have been employed to predict the inviscid counterpart of this flow. The spatial BiGlobal eigenvalue problem governing linear small-amplitude perturbations superposed upon the viscous three-dimensional wake has been solved at several axial locations, and results were used to initialize linear PSE-3D analyses without any simplifying assumptions regarding the form of the trailing vortex system, other than weak dependence of all flow quantities on the axial spatial direction. Two classes of linearly unstable perturbations were identified, namely stronger-amplified symmetric modes and weaker-amplified antisymmetric disturbances, both peaking at the vortex sheet which connects the trailing vortices. The amplitude functions of both classes of modes were documented, and their characteristics were compared with those delivered by local linear stability analysis in the wake near the symmetry plane and in the vicinity of the vortex core. While all linear instability analysis approaches employed have delivered qualitatively consistent predictions, only PSE-3D is free from assumptions regarding the underlying base flow and should thus be employed to obtain quantitative information on amplification rates and amplitude functions in this class of configurations.

  15. Thermodynamics of Inozemtsev's elliptic spin chain

    NASA Astrophysics Data System (ADS)

    Klabbers, Rob

    2016-06-01

    We study the thermodynamic behaviour of Inozemtsev's long-range elliptic spin chain using the Bethe ansatz equations describing the spectrum of the model in the infinite-length limit. We classify all solutions of these equations in that limit and argue which of these solutions determine the spectrum in the thermodynamic limit. Interestingly, some of the solutions are not selfconjugate, which puts the model in sharp contrast to one of the model's limiting cases, the Heisenberg XXX spin chain. Invoking the string hypothesis we derive the thermodynamic Bethe ansatz equations (TBA-equations) from which we determine the Helmholtz free energy in thermodynamic equilibrium and derive the associated Y-system. We corroborate our results by comparing numerical solutions of the TBA-equations to a direct computation of the free energy for the finite-length hamiltonian. In addition we confirm numerically the interesting conjecture put forward by Finkel and González-López that the original and supersymmetric versions of Inozemtsev's elliptic spin chain are equivalent in the thermodynamic limit.

  16. The acetabular component: an elliptical monoblock alternative.

    PubMed

    Sculco, Thomas P

    2002-06-01

    The major failure mode of cemented or noncemented acetabular fixation is osteolysis produced by biologic reaction to polyethylene and metallic debris. A monoblock acetabular noncemented component offers advantages in reducing the failure mechanism of acetabular cups. First, there is no extra-articular back surface polyethylene wear. Second, locking rings that may generate metallic debris are eliminated. Third, screw-holes, which decrease the surface area for ingrowth, are not needed, and pelvic entrance points for wear debris are eliminated. Fourth, an elliptical configuration allows better coaptation of the shell to the dome of the acetabulum. I have implanted >2,400 elliptical monoblock acetabular cups with a short-term follow-up of 6.5 years, with >4 years of follow-up in 840 hips. There have been no mechanical failures requiring revision. Four patients have been revised for recurrent hip instability, and one has been revised for infection. The need to convert to an acetabular component with screw fixation because of poor press-fit is <1%. PMID:12068420

  17. Working charts for the stress analysis of elliptic rings

    NASA Technical Reports Server (NTRS)

    Burke, Walter F

    1933-01-01

    This report presents charts which reduce the stress analysis of circular and elliptic rings of uniform cross section subjected to balanced systems of concentrated loads from a statically indeterminate problem to a statically determinate one. To demonstrate the use of the charts in the stress analysis of elliptic rings, an illustrative problem is included.

  18. Elliptical Orbit [arrow right] 1/r[superscript 2] Force

    ERIC Educational Resources Information Center

    Prentis, Jeffrey; Fulton, Bryan; Hesse, Carol; Mazzino, Laura

    2007-01-01

    Newton's proof of the connection between elliptical orbits and inverse-square forces ranks among the "top ten" calculations in the history of science. This time-honored calculation is a highlight in an upper-level mechanics course. It would be worthwhile if students in introductory physics could prove the relation "elliptical orbit" [arrow right]…

  19. Elliptic cylinder geometry for distinguishability analysis in impedance tomography.

    PubMed

    Saka, Birsen; Yilmaz, Atila

    2004-01-01

    Electrical impedance tomography (EIT) is a technique that computes the cross-sectional impedance distribution within the body by using current and voltage measurements made on the body surface. It has been reported that the image reconstruction is distorted considerably when the boundary shape is considered to be more elliptical than circular as a more realistic shape for the measurement boundary. This paper describes an alternative framework for determining the distinguishability region with a finite measurement precision for different conductivity distributions in a body modeled by elliptic cylinder geometry. The distinguishable regions are compared in terms of modeling error for predefined inhomogeneities with elliptical and circular approaches for a noncircular measurement boundary at the body surface. Since most objects investigated by EIT are noncircular in shape, the analytical solution for the forward problem for the elliptical cross section approach is shown to be useful in order to reach a better assessment of the distinguishability region defined in a noncircular boundary. This paper is concentrated on centered elliptic inhomogeneity in the elliptical boundary and an analytic solution for this type of forward problem. The distinguishability performance of elliptical cross section with cosine injected current patterns is examined for different parameters of elliptical geometry. PMID:14723501

  20. The size-frequency distribution of elliptical impact craters

    NASA Astrophysics Data System (ADS)

    Collins, G. S.; Elbeshausen, D.; Davison, T. M.; Robbins, S. J.; Hynek, B. M.

    2011-10-01

    Impact craters are elliptical in planform if the impactor's trajectory is below a threshold angle of incidence. Laboratory experiments and 3D numerical simulations demonstrate that this threshold angle decreases as the ratio of crater size to impactor size increases. According to impact cratering scaling laws, this implies that elliptical craters occur at steeper impact angles as crater size or target strength increases. Using a standard size-frequency distribution for asteroids impacting the terrestrial planets we estimate the fraction of elliptical craters as a function of crater size on the Moon, Mars, Earth, Venus and Mercury. In general, the expected fraction of elliptical craters is ~ 2-4% for craters between 5 and 100-km in diameter, consistent with the observed population of elliptical craters on Mars. At larger crater sizes both our model and observations suggest a dramatic increase in the fraction of elliptical craters with increasing crater diameter. The observed fraction of elliptical craters larger than 100-km diameter is significantly greater than our model predictions, which may suggest that there is an additional source of large elliptical craters other than oblique impact.

  1. Modified Elliptic Gamma Functions and 6d Superconformal Indices

    NASA Astrophysics Data System (ADS)

    Spiridonov, Vyacheslav P.

    2014-04-01

    We construct a modified double elliptic gamma function which is well defined when one of the base parameters lies on the unit circle. A model consisting of 6d hypermultiplets coupled to a gauge field theory living on a 4d defect is proposed whose superconformal index uses the double elliptic gamma function and obeys W( E 7)-group symmetry.

  2. Elliptic-blending second-moment turbulence closure using an algebraic anisotropic dissipation rate tensor model

    NASA Astrophysics Data System (ADS)

    Shin, Jong-Keun; Seo, Jeong-Sik; Choi, Young-Don

    2009-06-01

    This study describes the amendment of an algebraic anisotropic dissipation rate model (ADRM) and its application to various turbulent flows to test the model's performance. Modeling anisotropies for the turbulence dissipation rate is considered by an analysis of the exact transport equation for the dissipation rate tensor. The second-moment closure, which is based on the explicit amended ADRM, is proposed and it is closely linked to the elliptic-blending model that is used for the prediction of Reynolds stresses. To develop and calibrate the present elliptic-blending second-moment closure that uses the amended ADRM, firstly, the distributions of both the mean velocity and Reynolds stress are solved for flows in a fully developed non-rotating channel and a straight square duct. And then, the fully developed turbulent flows in a rotating channel and a rotating straight square duct are predicted to test the ability of the explicit amended ADRM that is combined with the rotation effect. The prediction results are directly compared with the DNS and the large-eddy simulation (LES) to assess the performance of the new model predictions and to show their reasonable agreement with the DNS and LES data for all the flow fields that are analyzed for the present study. This paper is a modified version of the original article from the Proceedings of the 5th International Symposium on Turbulence and Shear Flow Phenomena held in Munich, Germany on 27-29 August 2007.

  3. Excitation of THz hybrid modes in an elliptical dielectric rod waveguide with a cold collisionless unmagnetized plasma column by an annular electron beam

    NASA Astrophysics Data System (ADS)

    Rahmani, Z.; Heidari-Semiromi, E.; Safari, S.

    2016-06-01

    The dispersion relation of electromagnetic waves propagating in an elliptical plasma waveguide with a cold collisionless unmagnetized plasma column and a dielectric rod is studied analytically. The frequency spectrum of the hybrid waves and the growth rate for excitation of the waves by a thin annular relativistic elliptical electron beam (TAREEB) is obtained. The effects of relative permittivity constant of dielectric rod, geometrical dimensions, plasma frequency, accelerating voltage, and current density of TAREEB on the growth rate and frequency spectra of the waveguide will be investigated.

  4. Subregions of Motion and Elliptic Halo Orbits in the Elliptic Restricted Three-Body Problem

    NASA Technical Reports Server (NTRS)

    Campagnola, Stefano; Lo, Martin; Newton, Paul

    2008-01-01

    In this paper we present regions of motion and periodic orbits in the spatial elliptic restricted three body problem (ER3BP). Periodic orbits and regions of motion are fundamental keys to understand any dynamical system; for this reason the Hill's surfaces or the families of halo orbits have been extensively studied in the frame of the circular restricted three body problem. It is our opinion that their natural extensions to the ER3BP have not been studied enough. We divide the position space into forbidden subregions, subregions of motion and low-velocity subregions.We use these notions to define necessary condition for a transfer trajectory in the ER3BP. Also we compute branches of elliptic halo orbits bifurcating from halo orbits in the circular restricted three body problem. The new periodic orbits have principal periods and stability properties different from those of the originating halo orbit.

  5. Crack-face displacements for embedded elliptic and semi-elliptical surface cracks

    NASA Technical Reports Server (NTRS)

    Raju, I. S.

    1989-01-01

    Analytical expressions for the crack-face displacements of an embedded elliptic crack in infinite solid subjected to arbitrary tractions are obtained. The tractions on the crack faces are assumed to be expressed in a polynomial form. These displacements expressions complete the exact solution of Vijayakumar and Atluri, and Nishioki and Atluri. For the special case of an embedded crack in an infinite solid subjected to uniform pressure loading, the present displacements agree with those by Green and Sneddon. The displacement equations derived were used with the finite-element alternating method (FEAM) for the analysis of a semi-elliptic surface crack in a finite solid subjected to remote tensile loading. The maximum opening displacements obtained with FEAM are compared to those with the finite-element method with singularity elements. The maximum crack opening displacements by the two methods showed good agreement.

  6. The elliptic billiard: subtleties of separability

    NASA Astrophysics Data System (ADS)

    van Zon, R.; Ruijgrok, Th W.

    1998-01-01

    Some of the subtleties of the integrability of the elliptic quantum billiard are discussed. Considering a well known classical constant of the motion in the quantum case, we find that a naive calculation of the commutator with the Hamiltonian does not show whether or not it is zero. It is shown how this problem can be solved. A geometric picture is given that reveals why levels of a separable system cross. It is shown that the repulsions found by Ayant and Arvieu are computational effects and that the method used by Traiber et al is related to the present picture which explains the crossings they find. An asymptotic formula for the energy levels is derived and it is found that the statistical quantities of the spectrum P(s) and 0143-0807/19/1/011/img1 have the form expected for an integrable system.

  7. Theoretical results for starved elliptical contacts

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.; Dowson, D.

    1983-01-01

    Eighteen cases were used in the theoretical study of the influence of lubricant starvation on film thickness and pressure in elliptical elastohydrodynamic conjunctions. From the results a simple and important critical dimensionless inlet boundary distance at which lubricant starvation becomes significant was specified. This inlet boundary distance defines whether a fully flooded or a starved condition exists in the contact. Furthermore, it was found that the film thickness for a starved condition is written in dimensionless terms as a function of the inlet distance parameter and the film thickness for a fully flooded condition. Contour plots of pressure and film thickness in and around the contact are shown for fully flooded and starved conditions.

  8. Winding light beams along elliptical helical trajectories

    NASA Astrophysics Data System (ADS)

    Wen, Yuanhui; Chen, Yujie; Zhang, Yanfeng; Chen, Hui; Yu, Siyuan

    2016-07-01

    Conventional caustic methods in real or Fourier space produced accelerating optical beams only with convex trajectories. We developed a superposition caustic method capable of winding light beams along nonconvex trajectories. We ascertain this method by constructing a one-dimensional (1D) accelerating beam moving along a sinusoidal trajectory, and subsequently extending to two-dimensional (2D) accelerating beams along arbitrarily elliptical helical trajectories. We experimentally implemented the method with a compact and robust integrated optics approach by fabricating micro-optical structures on quartz glass plates to perform the spatial phase and amplitude modulation to the incident light, generating beam trajectories highly consistent with prediction. The theoretical and implementation methods can in principle be extended to the construction of accelerating beams with a wide variety of nonconvex trajectories, thereby opening up a route of manipulating light beams for fundamental research and practical applications.

  9. Interior models of Mercury with equatorial ellipticity

    NASA Astrophysics Data System (ADS)

    Dumberry, M.

    2012-09-01

    The combination of planetary rotation observations and gravity field measurements by the MESSENGER spacecraft can be used to constrain the internal structure of Mercury. A recently published model suggests a mean mantle density of ρm = 3650 ± 225 kg m-3, substantially larger than that expected of a silicate mantle (3300 kg m-3) and possibly hinting at the presence of an FeS-rich layer at the base of the mantle. Here, we show that a large ρm is only required if the core-mantle boundary (CMB) of the planet is assumed axially-symmetric. An equatorial ellipticity of CMB of the order of 2 · 10-5 allows to satisfy gravity and rotation constraints with a mean mantle density typical of silicate material. Possible origin of such topography include past mantle convection, aspherical planetary shrinking, remnant tidal deformation, or a combination thereof.

  10. Products of Independent Elliptic Random Matrices

    NASA Astrophysics Data System (ADS)

    O'Rourke, Sean; Renfrew, David; Soshnikov, Alexander; Vu, Van

    2015-07-01

    For fixed , we study the product of independent elliptic random matrices as tends to infinity. Our main result shows that the empirical spectral distribution of the product converges, with probability , to the -th power of the circular law, regardless of the joint distribution of the mirror entries in each matrix. This leads to a new kind of universality phenomenon: the limit law for the product of independent random matrices is independent of the limit laws for the individual matrices themselves. Our result also generalizes earlier results of Götze-Tikhomirov (On the asymptotic spectrum of products of independent random matrices, available at http://arxiv.org/abs/1012.2710) and O'Rourke-Soshnikov (J Probab 16(81):2219-2245, 2011) concerning the product of independent iid random matrices.

  11. Horizon complementarity in elliptic de Sitter space

    NASA Astrophysics Data System (ADS)

    Hackl, Lucas; Neiman, Yasha

    2015-02-01

    We study a quantum field in elliptic de Sitter space dS4/Z2—the spacetime obtained from identifying antipodal points in dS4. We find that the operator algebra and Hilbert space cannot be defined for the entire space, but only for observable causal patches. This makes the system into an explicit realization of the horizon complementarity principle. In the absence of a global quantum theory, we propose a recipe for translating operators and states between observers. This translation involves information loss, in accordance with the fact that two observers see different patches of the spacetime. As a check, we recover the thermal state at the de Sitter temperature as a state that appears the same to all observers. This thermal state arises from the same functional that, in ordinary dS4, describes the Bunch-Davies vacuum.

  12. Magnetic elliptical polarization of Schumann resonances

    SciTech Connect

    Sentman, D.D.

    1987-08-01

    Measurements of orthogonal, horizontal components of the magnetic field in the ELF range obtained during September 1985 show that the Schumann resonance eigenfrequencies determined separately for the north-south and east-west magnetic components differ by as much as 0.5 Hz, suggesting that the underlying magnetic signal is not linearly polarized at such times. The high degree of magnetic ellipticity found suggests that the side multiplets of the Schumann resonances corresponding to azimuthally inhomogeneous normal modes are strongly excited in the highly asymmetric earth-ionosphere cavity. The dominant sense of polarization over the measurement passband is found to be right-handed during local daylight hours, and to be left-handed during local nighttime hours. 16 references.

  13. Magnetic elliptical polarization of Schumann resonances

    NASA Technical Reports Server (NTRS)

    Sentman, D. D.

    1987-01-01

    Measurements of orthogonal, horizontal components of the magnetic field in the ELF range obtained during September 1985 show that the Schumann resonance eigenfrequencies determined separately for the north-south and east-west magnetic components differ by as much as 0.5 Hz, suggesting that the underlying magnetic signal is not linearly polarized at such times. The high degree of magnetic ellipticity found suggests that the side multiplets of the Schumann resonances corresponding to azimuthally inhomogeneous normal modes are strongly excited in the highly asymmetric earth-ionosphere cavity. The dominant sense of polarization over the measurement passband is found to be right-handed during local daylight hours, and to be left-handed during local nighttime hours.

  14. Ultrasonic guided waves in elliptical annular cylinders.

    PubMed

    Rajagopal, Prabhu; Pattanayak, Roson Kumar

    2015-09-01

    This paper studies the influence of cross-section ovalness or ellipticity on lower order axisymmetric guided wave modes in thin pipes. The second longitudinal mode L(0,2) and the fundamental torsional mode T(0,1) are studied, as these are of interest to current pipe inspection. The semi-analytical finite element (FE) method is mainly used, with three-dimensional FE simulations for visualization and cross-validation of results. The studies reveal that even a small degree of ovalness can affect mode shapes and velocities. The effect is more pronounced on the L(0,2) mode than on T(0,1) and this may be important for practical inspection applications. PMID:26428836

  15. Nonlinear, dispersive, elliptically polarized Alfven wavaes

    NASA Technical Reports Server (NTRS)

    Kennel, C. F.; Buti, B.; Hada, T.; Pellat, R.

    1988-01-01

    The derivative nonlinear Schroedinger (DNLS) equation is derived by an efficient means that employs Lagrangian variables. An expression for the stationary wave solutions of the DNLS that contains vanishing and nonvanishing and modulated and nonmodulated boundary conditions as subcases is then obtained. The solitary wave solutions for elliptically polarized quasiparallel Alfven waves in the magnetohydrodynamic limit (nonvanishing, unmodulated boundary conditions) are obtained. These converge to the Korteweg-de Vries and the modified Korteweg-de Vries solitons obtained previously for oblique propagation, but are more general. It is shown that there are no envelope solitary waves if the point at infinity is unstable to the modulational instability. The periodic solutions of the DNLS are characterized.

  16. Elliptical Undulators HU256 for Synchrotron SOLEIL

    SciTech Connect

    Batrakov, A.; Churkin, I.; Ilyin, I.; Kolokolnikov, Yu.; Rouvinski, E.; Semenov, E.; Steshov, A.; Vobly, P.; Briquez, F.; Chubar, O.; Dael, A.; Marcouile, O.; Marteau, F.; Roux, G.; Valleau, M.

    2007-01-19

    Three elliptical undulators HU256 of electromagnetic type were produced, tested and magnetically measured by the Budker Institute of Nuclear Physics (Russia) for Synchrotron Soleil (France). The undulators have a new design of a Bx and Bz closed structure for insertion vacuum chamber. In the elliptical undulator HU256 with period of the magnetic fields of 256 mm, the vertical magnetic field (Bzmax=0.44 T) formed by 27 Bz laminated dipole magnets is symmetric, and the horizontal magnetic field (Bxmax=0.33 T) formed by 28 Bx laminated dipole magnets is asymmetric. The undulator can work in standard mode as well as in a quasi-periodical mode. The vertical magnetic field may be modulated by switching on the modulation coils placed on the Bz dipoles. Two power supply systems allow us to modulate the horizontal magnetic field, and change the radiation spectrum. The magnetic calculations of the individual dipoles and dipoles in ''undulator'' environment were executed by means of Mermaid 3D Code. The magnetic measurements of the individual dipoles had confirmed the magnetic calculations. On basis of semiempirical dependences from the mechanical characteristics the estimates of the magnetic parameters for all dipoles were calculated. Sorting of dipoles in the undulators have been done, and it has improved the magnetic parameters of the assembled undulators in comparison with the statistical estimations. The magnetic measurements of the undulators HU256 were carried out at Budker INP by Hall probes and at Soleil by Hall probes and Stretched Wire. Now the 1st undulator HU256 is installed at Soleil Storage Ring.

  17. Elliptical Undulators HU256 for Synchrotron SOLEIL

    NASA Astrophysics Data System (ADS)

    Batrakov, A.; Briquez, F.; Chubar, O.; Churkin, I.; Dael, A.; Ilyin, I.; Kolokolnikov, Yu.; Marcouile, O.; Marteau, F.; Roux, G.; Rouvinski, E.; Semenov, E.; Steshov, A.; Valleau, M.; Vobly, P.

    2007-01-01

    Three elliptical undulators HU256 of electromagnetic type were produced, tested and magnetically measured by the Budker Institute of Nuclear Physics (Russia) for Synchrotron Soleil (France). The undulators have a new design of a Bx & Bz closed structure for insertion vacuum chamber. In the elliptical undulator HU256 with period of the magnetic fields of 256 mm, the vertical magnetic field (Bzmax=0.44 T) formed by 27 Bz laminated dipole magnets is symmetric, and the horizontal magnetic field (Bxmax=0.33 T) formed by 28 Bx laminated dipole magnets is asymmetric. The undulator can work in standard mode as well as in a quasi-periodical mode. The vertical magnetic field may be modulated by switching on the modulation coils placed on the Bz dipoles. Two power supply systems allow us to modulate the horizontal magnetic field, and change the radiation spectrum. The magnetic calculations of the individual dipoles and dipoles in "undulator" environment were executed by means of Mermaid 3D Code. The magnetic measurements of the individual dipoles had confirmed the magnetic calculations. On basis of semiempirical dependences from the mechanical characteristics the estimates of the magnetic parameters for all dipoles were calculated. Sorting of dipoles in the undulators have been done, and it has improved the magnetic parameters of the assembled undulators in comparison with the statistical estimations. The magnetic measurements of the undulators HU256 were carried out at Budker INP by Hall probes and at Soleil by Hall probes and Stretched Wire. Now the 1st undulator HU256 is installed at Soleil Storage Ring.

  18. Elliptic solitons in optical fiber media

    NASA Astrophysics Data System (ADS)

    Fandio Jubgang, Défi, Jr.; Dikandé, Alain M.; Sunda-Meya, A.

    2015-11-01

    We examine the evolution of a time-varying perturbation signal pumped into a monomode fiber in the anomalous dispersion regime. We establish analytically that the perturbation evolves into a conservative pattern of periodic pulses whose structures and profiles share a close similarity with the so-called soliton-crystal states recently observed in fiber media [see, e.g., A. Haboucha et al., Phys. Rev. A 78, 043806 (2008), 10.1103/PhysRevA.78.043806; D. Y. Tang et al., Phys. Rev. Lett. 101, 153904 (2008), 10.1103/PhysRevLett.101.153904; F. Amrani et al., Opt. Express 19, 13134 (2011), 10.1364/OE.19.013134]. We derive mathematically and generate numerically a crystal of solitons using time-division multiplexing of identical pulses. We suggest that at very fast pumping rates, the pulse signals overlap and create an unstable signal that is modulated by the fiber nonlinearity to become a periodic lattice of pulse solitons that can be described by elliptic functions. We carry out a linear stability analysis of the soliton-crystal structure and establish that the correlation of centers of mass of interacting pulses broadens their internal-mode spectrum, some modes of which are mutually degenerate. While it has long been known that high-intensity periodic pulse trains in optical fibers are generated from the phenomenon of modulational instability of continuous waves, the present study provides evidence that they can also be generated via temporal multiplexing of an infinitely large number of equal-intensity single pulses to give rise to stable elliptic solitons.

  19. Strong-field approximation for ionization of a diatomic molecule by a strong laser field. III. High-order above-threshold ionization by an elliptically polarized field

    SciTech Connect

    Busuladzic, M.; Gazibegovic-Busuladzic, A.; Milosevic, D. B.

    2009-07-15

    We investigate high-order above-threshold ionization (HATI) of diatomic molecules having different symmetries by an elliptically polarized laser field using the modified molecular strong-field approximation. The yields of high-energy electrons contributing to the plateau region of the photoelectron spectra strongly depend on the employed ellipticity. This is more pronounced if the major axis of the polarization ellipse is parallel or perpendicular to the molecular axis and at the end of the high-energy plateau. For the O{sub 2} molecule (characterized by {pi}{sub g} symmetry) the maximum yield is observed for some value of the ellipticity {epsilon} different from zero. On the other hand, in the same circumstances, the N{sub 2} molecule ({sigma}{sub g}) behaves as an atom, i.e., the yield is maximum for {epsilon}=0. These characteristics of the photoelectron spectra remain valid in a wide region of the molecular orientations and laser peak intensities. The symmetry properties of the molecular HATI spectra are considered in detail: by changing the molecular orientation one or other type of the symmetry emerges or disappears. Presenting differential ionization spectra in the ionized electron energy-emission angle plane we have observed similar interference effects as in the HATI spectra governed by a linearly polarized field.

  20. Strong-field approximation for ionization of a diatomic molecule by a strong laser field. III. High-order above-threshold ionization by an elliptically polarized field

    NASA Astrophysics Data System (ADS)

    Busuladžić, M.; Gazibegović-Busuladžić, A.; Milošević, D. B.

    2009-07-01

    We investigate high-order above-threshold ionization (HATI) of diatomic molecules having different symmetries by an elliptically polarized laser field using the modified molecular strong-field approximation. The yields of high-energy electrons contributing to the plateau region of the photoelectron spectra strongly depend on the employed ellipticity. This is more pronounced if the major axis of the polarization ellipse is parallel or perpendicular to the molecular axis and at the end of the high-energy plateau. For the O2 molecule (characterized by πg symmetry) the maximum yield is observed for some value of the ellipticity ɛ different from zero. On the other hand, in the same circumstances, the N2 molecule (σg) behaves as an atom, i.e., the yield is maximum for ɛ=0 . These characteristics of the photoelectron spectra remain valid in a wide region of the molecular orientations and laser peak intensities. The symmetry properties of the molecular HATI spectra are considered in detail: by changing the molecular orientation one or other type of the symmetry emerges or disappears. Presenting differential ionization spectra in the ionized electron energy-emission angle plane we have observed similar interference effects as in the HATI spectra governed by a linearly polarized field.

  1. Origin of the mass splitting of elliptic anisotropy in a multiphase transport model

    NASA Astrophysics Data System (ADS)

    Li, Hanlin; He, Liang; Lin, Zi-Wei; Molnar, Denes; Wang, Fuqiang; Xie, Wei

    2016-05-01

    The mass splitting of elliptic anisotropy (v2) at low transverse momentum is considered as a hallmark of hydrodynamic collective flow. We investigate a multiphase transport (AMPT) model where the v2 is mainly generated by an anisotropic escape mechanism, not of the hydrodynamic flow nature, and where mass splitting is also observed. We demonstrate that the v2 mass splitting in AMPT is small right after hadronization (especially when resonance decays are included); the mass splitting mainly comes from hadronic rescatterings, even though their contribution to the overall charged hadron v2 is small. These findings are qualitatively the same as those from hybrid models that combine hydrodynamics with a hadron cascade. We further show that there is no qualitative difference between heavy ion collisions and small system collisions. Our results indicate that the v2 mass splitting is not a unique signature of hydrodynamic collective flow and thus cannot distinguish whether the elliptic flow is generated mainly from hydrodynamics or the anisotropic parton escape.

  2. Laplacian growth, elliptic growth, and singularities of the Schwarz potential

    NASA Astrophysics Data System (ADS)

    Lundberg, Erik

    2011-04-01

    The Schwarz function has played an elegant role in understanding and in generating new examples of exact solutions to the Laplacian growth (or 'Hele-Shaw') problem in the plane. The guiding principle in this connection is the fact that 'non-physical' singularities in the 'oil domain' of the Schwarz function are stationary, and the 'physical' singularities obey simple dynamics. We give an elementary proof that the same holds in any number of dimensions for the Schwarz potential, introduced by Khavinson and Shapiro (1989 Technical Report TRITA-MAT-1989-36 Royal Institute of Technology, Stockholm). An extension is also given for the so-called elliptic growth problem by defining a generalized Schwarz potential. New exact solutions are constructed, and we solve inverse problems of describing the driving singularities of a given flow. We demonstrate, by example, how {C}^n-techniques can be used to locate the singularity set of the Schwarz potential. One of our methods is to prolong available local extension theorems by constructing 'globalizing families'.

  3. Elliptic Volume Grid Generation for Viscous CFD Parametric Design Studies

    NASA Technical Reports Server (NTRS)

    Alter, Stephen J.; Cheatwood, F. McNeil

    1996-01-01

    This paper presents a robust method for the generation of zonal volume grids of design parametrics for aerodynamic configurations. The process utilizes simple algebraic techniques with parametric splines coupled with elliptic volume grid generation to generate isolated zonal grids for changes in body configuration needed to perform parametric design studies. Speed of the algorithm is maximized through the algebraic methods and reduced number of grid points to be regenerated for each design parametric without sacrificing grid quality and continuity within the volume domain. The method is directly applicable to grid reusability, because it modifies existing ow adapted volume grids and enables the user to restart the CFD solution process with an established flow field. Use of this zonal approach reduces computer usage time to create new volume grids for design parametric studies by an order of magnitude, as compared to current methods which require the regeneration of an entire volume grid. A sample configuration of a proposed Single Stage-to-Orbit Vehicle is used to illustrate an application of this method.

  4. An Elliptical Crystal Spectrometer Suitable for EXAFS Studies of Laser Compressed Materials and for High Resolution X-Ray Spectroscopy.

    PubMed

    Ridgeley, A; Goodman, D; Hall, T A

    1995-01-01

    Using an x-ray spectrometer with an elliptically curved crystal it is possible to study absorption spectra from a target placed at one focus of the ellipse using a backlighting source placed at the other focus. This principle has been used to develop a spectrometer for EXAFS studies of laser compressed materials. The backlighting source is placed at one focus of the ellipse and the laser compressed EXAFS sample at the other. Using this technique a small area of the EXAFS target can be probed, thereby minimizing any spatial variations in the compressed plasma due to nonuniformities in the laser beams. Also, the dispersive nature of the crystal ensures that it acts as a bandpass filter, so that the EXAFS sample is not probed by other x-ray wavelengths which may cause unwanted heating. Another advantage is that compressed and uncompressed EXAFS spectra can be compared on a single shot. The optical properties of the spectrometer are discussed analytically and using a computer ray-tracing program. The development and alignment of the elliptical spectrometer are discussed, and its performance using both x-ray film and a CCD detector is evaluated. The use of the elliptical spectrometer as a high-resolution x-ray instrument is presented. PMID:21307480

  5. From X- to O-shaped spatiotemporal spectra of light filaments in water.

    PubMed

    Porras, Miguel A; Dubietis, Audrius; Kucinskas, Ernestas; Bragheri, Francesca; Degiorgio, Vittorio; Couairon, Arnaud; Faccio, Daniele; Di Trapani, Paolo

    2005-12-15

    We show that the angle-wavelength spectra of light filaments excited by ultrashort pulses experience a transition from X- to O-like structures when their carrier wavelengths are switched from normal to anomalous dispersion. Calculations confirm that the O-shaped conical emission follows the elliptic geometry of the nonlinear Schrödinger equation with anomalous dispersion. PMID:16389844

  6. Dusty Feedback from Massive Black Holes in Two Elliptical Galaxies

    NASA Technical Reports Server (NTRS)

    Temi, P.; Brighenti, F.; Mathews, W. G.; Amblard, A.; Riguccini, L.

    2013-01-01

    Far-infrared dust emission from elliptical galaxies informs us about galaxy mergers, feedback energy outbursts from supermassive black holes and the age of galactic stars. We report on the role of AGN feedback observationally by looking for its signatures in elliptical galaxies at recent epochs in the nearby universe. We present Herschel observations of two elliptical galaxies with strong and spatially extended FIR emission from colder grains 5-10 kpc distant from the galaxy cores. Extended excess cold dust emission is interpreted as evidence of recent feedback-generated AGN energy outbursts in these galaxies, visible only in the FIR, from buoyant gaseous outflows from the galaxy cores.

  7. New Elliptic Solutions of the Yang-Baxter Equation

    NASA Astrophysics Data System (ADS)

    Chicherin, D.; Derkachov, S. E.; Spiridonov, V. P.

    2016-07-01

    We consider finite-dimensional reductions of an integral operator with the elliptic hypergeometric kernel describing the most general known solution of the Yang-Baxter equation with a rank 1 symmetry algebra. The reduced R-operators reproduce at their bottom the standard Baxter's R-matrix for the 8-vertex model and Sklyanin's L-operator. The general formula has a remarkably compact form and yields new elliptic solutions of the Yang-Baxter equation based on the finite-dimensional representations of the elliptic modular double. The same result is also derived using the fusion formalism.

  8. New Elliptic Solutions of the Yang-Baxter Equation

    NASA Astrophysics Data System (ADS)

    Chicherin, D.; Derkachov, S. E.; Spiridonov, V. P.

    2016-02-01

    We consider finite-dimensional reductions of an integral operator with the elliptic hypergeometric kernel describing the most general known solution of the Yang-Baxter equation with a rank 1 symmetry algebra. The reduced R-operators reproduce at their bottom the standard Baxter's R-matrix for the 8-vertex model and Sklyanin's L-operator. The general formula has a remarkably compact form and yields new elliptic solutions of the Yang-Baxter equation based on the finite-dimensional representations of the elliptic modular double. The same result is also derived using the fusion formalism.

  9. Single optical tweezers based on elliptical core fiber

    NASA Astrophysics Data System (ADS)

    Zhang, Yu; Zhao, Li; Chen, Yunhao; Liu, Zhihai; Zhang, Yaxun; Zhao, Enming; Yang, Jun; Yuan, Libo

    2016-04-01

    We propose and demonstrate a new single optical tweezers based on an elliptical core fiber, which can realize the trapped yeast cell rotation with a precise and simple control. Due to the elliptical shape of the fiber core, the LP11 mode beam can propagate stably. When we rotate the fiber tip, the LP11 mode beam will also rotate along with the fiber tip, which helps to realize the trapped micro-particle rotation. By using this method, we can easily realize the rotation of the trapped yeast cells, the rotating angle of the yeast cell is same as the elliptical core fiber tip.

  10. Jacobi-Bessel analysis of reflector antennas with elliptical apertures

    NASA Technical Reports Server (NTRS)

    Rahmat-Samii, Yahya

    1987-01-01

    Although many reflector antennas possess circular projected apertures, there are recent satellite and ground antenna applications for which it is desirable to employ reflectors with elliptical apertures. Here a modification of the Jacobi-Bessel expansion is presented for the diffraction analysis of reflectors with elliptical apertures. A comparative study is also performed between this modified Jacobi-Bessel algorithm and the one which uses the Jacobi-Bessel expansion over a circumscribing circular region. Numerical results are presented for offset reflectors with elliptical and circular apertures and the improved convergence properties of the modified algorithm are highlighted.

  11. Non-linear tides in a homogeneous rotating planet or star: global simulations of the elliptical instability

    NASA Astrophysics Data System (ADS)

    Barker, Adrian J.

    2016-06-01

    I present results from the first global hydrodynamical simulations of the elliptical instability in a tidally deformed gaseous planet (or star) with a free surface. The elliptical instability is potentially important for tidal evolution of the shortest-period hot Jupiters. I model the planet as a spin-orbit aligned or anti-aligned, and non-synchronously rotating, tidally deformed, homogeneous fluid body. A companion paper presented an analysis of the global modes and instabilities of such a planet. Here I focus on the non-linear evolution of the elliptical instability. This is observed to produce bursts of turbulence that drive the planet towards synchronism with its orbit in an erratic manner. If the planetary spin is initially anti-aligned, the elliptical instability also drives spin-orbit alignment on a similar time-scale as the spin synchronization. The instability generates differential rotation inside the planet in the form of zonal flows, which play an important role in the saturation of the instability, and in producing the observed burstiness. These results are broadly consistent with the picture obtained using a local Cartesian model (where columnar vortices played the role of zonal flows). I also simulate the instability in a container that is rigid (but stress-free) rather than free, finding broad quantitative agreement. The dissipation resulting from the elliptical instability could explain why the shortest-period hot Jupiters tend to have circular orbits inside about 2-3 d, and predicts spin synchronization (and spin-orbit alignment) out to about 10-15 d. However, other mechanisms must be invoked to explain tidal circularization for longer orbital periods.

  12. Elliptic Relaxation of a Tensor Representation for the Redistribution Terms in a Reynolds Stress Turbulence Model

    NASA Technical Reports Server (NTRS)

    Carlson, J. R.; Gatski, T. B.

    2002-01-01

    A formulation to include the effects of wall proximity in a second-moment closure model that utilizes a tensor representation for the redistribution terms in the Reynolds stress equations is presented. The wall-proximity effects are modeled through an elliptic relaxation process of the tensor expansion coefficients that properly accounts for both correlation length and time scales as the wall is approached. Direct numerical simulation data and Reynolds stress solutions using a full differential approach are compared for the case of fully developed channel flow.

  13. Elliptic Solvers with Adaptive Mesh Refinement on Complex Geometries

    SciTech Connect

    Phillip, B.

    2000-07-24

    Adaptive Mesh Refinement (AMR) is a numerical technique for locally tailoring the resolution computational grids. Multilevel algorithms for solving elliptic problems on adaptive grids include the Fast Adaptive Composite grid method (FAC) and its parallel variants (AFAC and AFACx). Theory that confirms the independence of the convergence rates of FAC and AFAC on the number of refinement levels exists under certain ellipticity and approximation property conditions. Similar theory needs to be developed for AFACx. The effectiveness of multigrid-based elliptic solvers such as FAC, AFAC, and AFACx on adaptively refined overlapping grids is not clearly understood. Finally, a non-trivial eye model problem will be solved by combining the power of using overlapping grids for complex moving geometries, AMR, and multilevel elliptic solvers.

  14. Design and fabrication of embedded two elliptical cores hollow fiber

    NASA Astrophysics Data System (ADS)

    Tian, Fengjun; Yuan, Libo; Dai, Qian; Liu, Zhihai

    2011-11-01

    We propose a novel embedded two elliptical cores fiber with a hollow air hole, and demonstrate the fabrication of the embedded two elliptical cores hollow fiber (EECHF). By using a suspended core-in-tube technique, the fibers are drawn from the preform utilizing a fiber drawing system with a pressure controller. The fiber have a 60μm diameter hollow air hole centrally, a 125μm diameter cladding, two 7.2μm /3.0μm (major axis/minor axis) elliptical cores, and a 3μm thickness silica cladding between core layer and air hole. The EECHF has a great potential for PMFs, high sensitivity in-fiber interferometers, poling fiber and Bio-sensor based on evanescent wave field. The fabrication technology is simple and versatile, and can be easily utilized to fabricate multi-core fiber with any desired aspect ratio elliptical core.

  15. C1,1 regularity for degenerate elliptic obstacle problems

    NASA Astrophysics Data System (ADS)

    Daskalopoulos, Panagiota; Feehan, Paul M. N.

    2016-03-01

    The Heston stochastic volatility process is a degenerate diffusion process where the degeneracy in the diffusion coefficient is proportional to the square root of the distance to the boundary of the half-plane. The generator of this process with killing, called the elliptic Heston operator, is a second-order, degenerate-elliptic partial differential operator, where the degeneracy in the operator symbol is proportional to the distance to the boundary of the half-plane. In mathematical finance, solutions to the obstacle problem for the elliptic Heston operator correspond to value functions for perpetual American-style options on the underlying asset. With the aid of weighted Sobolev spaces and weighted Hölder spaces, we establish the optimal C 1 , 1 regularity (up to the boundary of the half-plane) for solutions to obstacle problems for the elliptic Heston operator when the obstacle functions are sufficiently smooth.

  16. Iterative methods for elliptic finite element equations on general meshes

    NASA Technical Reports Server (NTRS)

    Nicolaides, R. A.; Choudhury, Shenaz

    1986-01-01

    Iterative methods for arbitrary mesh discretizations of elliptic partial differential equations are surveyed. The methods discussed are preconditioned conjugate gradients, algebraic multigrid, deflated conjugate gradients, an element-by-element techniques, and domain decomposition. Computational results are included.

  17. New Observations Deepen Mystery Surrounding Water Masers in Elliptical Galaxy

    NASA Astrophysics Data System (ADS)

    New observations with the National Science Foundation's Very Long Baseline Array (VLBA) radio telescope have deepened the mystery surrounding water molecules in a galaxy 65 million light- years away. The water molecules are acting as natural masers -- amplifiers of microwave radio emissions -- and these cosmic masers within the galaxy NGC 1052 are raising difficult questions for astronomers trying to explain them. Results of the new observations, which pinpoint the location of water masers in NGC 1052, were announced today at the American Astronomical Society meeting in Toronto, Ontario. The researchers are: Jim Braatz of Harvard University in Cambridge, Massachusetts, Mark Claussen and Phil Diamond of the National Radio Astronomy Observatory in Socorro, New Mexico, Andrew Wilson of the University of Maryland in College Park, Maryland, and Christian Henkel of the Max Planck Institute fur Radioastronomie in Bonn, Germany. Water masers have been detected in several other galaxies. However, most galaxies containing water "megamasers" such as those in NGC 1052 are spiral galaxies. NGC 1052 is one of only two elliptical galaxies in which water megamasers have been detected. Because ellipticals tend to have much less gas and dust than spirals, the existence of the water masers in NGC 1052 is surprising by itself, though that galaxy does have more gas and dust than the typical elliptical. Located in the constellation Cetus, NGC 1052 also has an active nucleus, believed to be powered by the gravitational energy of a supermassive black hole at its core. The new VLBA observations produced an additional mystery. In other galaxies with water megamasers, the masers are believed to lie within a disk of molecules orbiting the galaxy's central black hole. This is the case, for example, in the now-famous galaxy NGC 4258, where the movement of the orbiting disk can be traced by measuring both the Doppler shift of radio emission from the masers and by tracking the motion of

  18. High angle-of-attack aerodynamic characteristics of crescent and elliptic wings

    NASA Technical Reports Server (NTRS)

    Vandam, C. P.

    1989-01-01

    Static longitudinal and lateral-directional forces and moments were measured for elliptic- and crescent-wing models at high angles-of-attack in the NASA Langley 14 by 22-Ft Subsonic Tunnel. The forces and moments were obtained for an angle-of-attack range including stall and post-stall conditions at a Reynolds number based on the average wing chord of about 1.8 million. Flow-visualization photographs using a mixture of oil and titanium-dioxide were also taken for several incidence angles. The force and moment data and the flow-visualization results indicated that the crescent wing model with its highly swept tips produced much better high angle-of-attack aerodynamic characteristics than the elliptic model. Leading-edge separation-induced vortex flow over the highly swept tips of the crescent wing is thought to produce this improved behavior at high angles-of-attack. The unique planform design could result in safer and more efficient low-speed airplanes.

  19. Numerical study of hydrogen-air supersonic combustion by using elliptic and parabolized equations

    NASA Technical Reports Server (NTRS)

    Chitsomboon, T.; Tiwari, S. N.

    1986-01-01

    The two-dimensional Navier-Stokes and species continuity equations are used to investigate supersonic chemically reacting flow problems which are related to scramjet-engine configurations. A global two-step finite-rate chemistry model is employed to represent the hydrogen-air combustion in the flow. An algebraic turbulent model is adopted for turbulent flow calculations. The explicit unsplit MacCormack finite-difference algorithm is used to develop a computer program suitable for a vector processing computer. The computer program developed is then used to integrate the system of the governing equations in time until convergence is attained. The chemistry source terms in the species continuity equations are evaluated implicitly to alleviate stiffness associated with fast chemical reactions. The problems solved by the elliptic code are re-investigated by using a set of two-dimensional parabolized Navier-Stokes and species equations. A linearized fully-coupled fully-implicit finite difference algorithm is used to develop a second computer code which solves the governing equations by marching in spce rather than time, resulting in a considerable saving in computer resources. Results obtained by using the parabolized formulation are compared with the results obtained by using the fully-elliptic equations. The comparisons indicate fairly good agreement of the results of the two formulations.

  20. Elliptical varied line-space (EVLS) gratings

    NASA Astrophysics Data System (ADS)

    Thomas, Roger J.

    2004-10-01

    Imaging spectroscopy at wavelengths below 2000 Å offers an especially powerful method for studying many extended high-temperature astronomical objects, like the Sun and its outer layers. But the technology to make such measurements is also especially challenging, because of the poor reflectance of all standard materials at these wavelengths, and because the observation must be made from above the absorbing effects of the Earth's atmosphere. To solve these problems, single-reflection stigmatic spectrographs for XUV wavelengths have bee flown on several space missions based on designs with toroidal uniform line-space (TULS) or spherical varied line-space (SVLS) gratings that operate at near normal-incidence. More recently, three solar EUV/UV instruments have been selected that use toroidal varied line-space (TVLS) gratings; these are SUMI and RAISE, both sounding rocket payloads, and NEXUS, a SMEX satellite-mission. The next logical extension to such designs is the use of elliptical surfaces for varied line-space (EVLS) rulings. In fact, EVLS designs are found to provide superior imaging even at very large spectrograph magnifications and beam-speeds, permitting extremely high-quality performance in remarkably compact instrument packages. In some cases, such designs may be optimized even further by using a hyperbolic surface for the feeding telescope. The optical characteristics of two solar EUV spectrometers based on these concepts are described: EUS and EUI, both being developed as possible instruments for ESA's Solar Orbiter mission by consortia led by RAL and by MSSL, respectively.

  1. Elliptical acoustic particle motion in underwater waveguides.

    PubMed

    Dall'Osto, David R; Dahl, Peter H

    2013-07-01

    Elliptical particle motion, often encountered in acoustic fields containing interference between a source signal and its reflections, can be quantified by the degree of circularity, a vector quantity formulated from acoustic particle velocity, or vector intensity measurements. Acoustic analysis based on the degree of circularity is expected to find application in ocean waveguides as its spatial dependence relates to the acquisition geometry, water column sound speed, surface conditions, and bottom properties. Vector sensor measurements from a laboratory experiment are presented to demonstrate the depth dependence of both the degree of circularity and an approximate formulation based on vertical intensity measurements. The approximation is applied to vertical intensity field measurements made in a 2006 experiment off the New Jersey coast (in waters 80 m deep) to demonstrate the effect of sediment structure on the range dependence of the degree of circularity. The mathematical formulation presented here establishes the framework to readily compute the degree of circularity from experimental measurements; the experimental examples are provided as evidence of the spatial and frequency dependence of this fundamental vector property. PMID:23862789

  2. Anomaly cancelling terms from the elliptic genus

    NASA Astrophysics Data System (ADS)

    Lerche, W.; Nilsson, B. E. W.; Schellekens, A. N.; Warner, N. P.

    1988-03-01

    We calculate the heterotic string one-loop diagram in 2n + 2 dimensions with one external Bμν and n external gravitons and/or gauge bosons. The result is a modular integral over the weight zero terms of the character valued partition function (or elliptic genus) of the theory, and can be directly expressed in terms of the factor which multiplies TrF2 - TrR2 in the field theory anomaly. The integrands have a non-trivial dependence on the modular parameter τ, reflecting contributions not only from the physical massless states but also from an infinity of ``unphysical'' modes. Some of them are identical to integrands which have been discussed recently in relation with Atkin-Lehner symmetry and the cosmological constant. As a corollary we find a method to compute these integrals without using Atkin-Lehner transformations. On leave of absence from: Department of Mathematics, Massachusetts Institute of Technology, Cambridge MA 02139, USA. Work supported in part by National Science Foundation Grant #84-07109.

  3. Banana orbits in elliptic tokamaks with hole currents

    NASA Astrophysics Data System (ADS)

    Martin, P.; Castro, E.; Puerta, J.

    2015-03-01

    Ware Pinch is a consequence of breaking of up-down symmetry due to the inductive electric field. This symmetry breaking happens, though up-down symmetry for magnetic surface is assumed. In previous work Ware Pinch and banana orbits were studied for tokamak magnetic surface with ellipticity and triangularity, but up-down symmetry. Hole currents appear in large tokamaks and their influence in Ware Pinch and banana orbits are now considered here for tokamaks magnetic surfaces with ellipticity and triangularity.

  4. Elliptical dichroism: operating principle of planar chiral metamaterials.

    PubMed

    Zhukovsky, Sergei V; Novitsky, Andrey V; Galynsky, Vladimir M

    2009-07-01

    We employ a homogenization technique based on the Lorentz electronic theory to show that planar chiral structures (PCSs) can be described by an effective dielectric tensor similar to that of biaxial elliptically dichroic crystals. Such a crystal is shown to behave like a PCS insofar as it exhibits its characteristic optical properties, namely, corotating elliptical polarization eigenstates and asymmetric, direction-dependent transmission for left- or right-handed incident wave polarization. PMID:19571975

  5. Depth-resolved measurements with elliptically polarized reflectance spectroscopy

    PubMed Central

    Bailey, Maria J.; Sokolov, Konstantin

    2016-01-01

    The ability of elliptical polarized reflectance spectroscopy (EPRS) to detect spectroscopic alterations in tissue mimicking phantoms and in biological tissue in situ is demonstrated. It is shown that there is a linear relationship between light penetration depth and ellipticity. This dependence is used to demonstrate the feasibility of a depth-resolved spectroscopic imaging using EPRS. The advantages and drawbacks of EPRS in evaluation of biological tissue are analyzed and discussed. PMID:27446712

  6. Interference of multiplane wings having elliptical lift distribution

    NASA Technical Reports Server (NTRS)

    Von Sanden, H

    1924-01-01

    In calculating the self-induction of a wing surface, elliptical lift distribution is assumed, while in calculating the mutual induction or interference of two wing surfaces, a uniform distribution of the lift along the wing has hitherto been assumed. Whether the results of these calculations are substantially altered by assuming an elliptical lift distribution (which is just as probable as uniform distribution) is examined here.

  7. Bifurcations in elliptical, asymmetric non-neutral plasmas

    NASA Astrophysics Data System (ADS)

    Fajans, Joel; Gilson, Erik

    1999-11-01

    When subjected to a stationary, l=2 potential perturbation on the wall, a pure electron plasma will deform into an elliptical shape. At first, the plasma's ellipticity is proportional to the strength of the potential perturbation. Once the perturbation is increased beyond a critical value, the plasma equilibrium bifurcates into two off-axis states. This bifurcation has been observed experimentally and will be described in this poster. (see http://socrates.berkeley.edu/ fajans/EquilStab/EllipseBifurcation.avi)

  8. Beam-beam deflection and signature curves for elliptic beams

    SciTech Connect

    Ziemann, V.

    1990-10-22

    In this note we will present closed expressions for the beam-beam deflection angle for arbitrary elliptic beams including tilt. From these expressions signature curves, i.e., systematic deviations from the round beam deflection curve due to ellipticity or tilt are derived. In the course of the presentation we will prove that it is generally impossible to infer individual beam sizes from beam-beam deflection scans. 3 refs., 2 figs.

  9. Production decline analysis for a multi-fractured horizontal well considering elliptical reservoir stimulated volumes in shale gas reservoirs

    NASA Astrophysics Data System (ADS)

    Wei, Mingqiang; Duan, Yonggang; Fang, Quantang; Zhang, Tiantian

    2016-06-01

    Multi-fractured horizontal wells (MFHWs) are an effective technique for developing shale gas reservoirs. After fracturing, stimulated reservoir volumes (SRVs) invariably exist around the wellbore. In this paper, a composite elliptical SRV model for each hydraulic fracturing stage is established, based on micro-seismic events. Both the SRV and the outer regions are assumed as single-porosity media with different formation physical parameters. Based on unstructured perpendicular bisection (PEBI) grids, a mathematical model considering Darcy flow, diffusion and adsorption/desorption in shale gas reservoirs is presented. The numerical solution is obtained by combining the control volume finite element method with the fully implicit method. The model is verified by a simplified model solution. The MFHW Blasingame production decline curves, which consider elliptical SRVs in shale gas reservoirs, are plotted by computer programming. The flow regions can be divided into five flow regimes: early formation linear flow, radial flow in the SRV region, transient flow, pseudo radial flow and boundary dominated flow. Finally, the effect of six related parameters, including the SRV area size, outer region permeability, SRV region permeability, Langmuir pressure, Langmuir volume and diffusion coefficient, are analyzed on type curves. The model presented in this paper can expand our understanding of MFHW production decline behaviors in shale gas reservoirs and can be applied to estimate reservoir properties, the SRV area, and reserves in these types of reservoirs by type curve matching.

  10. ELLIPT2D: A Flexible Finite Element Code Written Python

    SciTech Connect

    Pletzer, A.; Mollis, J.C.

    2001-03-22

    The use of the Python scripting language for scientific applications and in particular to solve partial differential equations is explored. It is shown that Python's rich data structure and object-oriented features can be exploited to write programs that are not only significantly more concise than their counter parts written in Fortran, C or C++, but are also numerically efficient. To illustrate this, a two-dimensional finite element code (ELLIPT2D) has been written. ELLIPT2D provides a flexible and easy-to-use framework for solving a large class of second-order elliptic problems. The program allows for structured or unstructured meshes. All functions defining the elliptic operator are user supplied and so are the boundary conditions, which can be of Dirichlet, Neumann or Robbins type. ELLIPT2D makes extensive use of dictionaries (hash tables) as a way to represent sparse matrices.Other key features of the Python language that have been widely used include: operator over loading, error handling, array slicing, and the Tkinter module for building graphical use interfaces. As an example of the utility of ELLIPT2D, a nonlinear solution of the Grad-Shafranov equation is computed using a Newton iterative scheme. A second application focuses on a solution of the toroidal Laplace equation coupled to a magnetohydrodynamic stability code, a problem arising in the context of magnetic fusion research.

  11. Quasar Radio-Loudness and the Elliptical Core Problem

    NASA Astrophysics Data System (ADS)

    Hamilton, Timothy S.

    2010-01-01

    The dichotomy between radio-loud and radio-quiet QSOs is not simply one of host morphology. While radio-louds are almost always found in elliptical hosts, radio-quiets are known to reside in both elliptical and spiral galaxies. We find that what determines whether a given elliptical galaxy will host either a radio-loud or radio-quiet QSO is a combination of accretion rate and host scale. QSOs with high x-ray luminosities (above 10e44.9 erg/s at 0.5 keV) are nearly all found to be radio-loud. But those with low luminosities divide fairly neatly along the Kormendy law, the correlation between re and μe. Those larger than about 10 kpc are radio-loud, while smaller ones are radio-quiet. It has recently been found that core and coreless ellipticals are also divided at about this limit. This implies that for low-luminosity QSOs, radio-louds are found in core ellipticals, while radio-quiets are in coreless ellipticals and spirals. This segregation shows up particularly strongly for low-redshift objects. Since the presence or absence of a core may be tied to the galactic merger history, we have an evolutionary explanation for the differences between radio-loud and radio-quiet QSOs.

  12. Grid generation by elliptic partial differential equations for a tri-element Augmentor-Wing airfoil

    NASA Technical Reports Server (NTRS)

    Sorenson, R. L.

    1982-01-01

    Two efforts to numerically simulate the flow about the Augmentor-Wing airfoil in the cruise configuration using the GRAPE elliptic partial differential equation grid generator algorithm are discussed. The Augmentor-Wing consists of a main airfoil with a slotted trailing edge for blowing and two smaller airfoils shrouding the blowing jet. The airfoil and the algorithm are described, and the application of GRAPE to an unsteady viscous flow simulation and a transonic full-potential approach is considered. The procedure involves dividing a complicated flow region into an arbitrary number of zones and ensuring continuity of grid lines, their slopes, and their point distributions across the zonal boundaries. The method for distributing the body-surface grid points is discussed.

  13. Night Spectra Quest.

    ERIC Educational Resources Information Center

    Jacobs, Stephen

    1995-01-01

    Presents the Night Spectra Quest, a pocket-sized chart that identifies in color the spectra of all the common night lights and has an integrally mounted, holographic diffraction grating to look through. (JRH)

  14. Formation, evolution and properties of isolated field elliptical galaxies

    NASA Astrophysics Data System (ADS)

    Niemi, Sami-Matias; Heinämäki, Pekka; Nurmi, Pasi; Saar, Enn

    2010-06-01

    We study the properties, evolution and formation mechanisms of isolated field elliptical (IfE) galaxies. We create a `mock' catalogue of IfE galaxies from the Millennium Simulation Galaxy Catalogue, and trace their merging histories. The formation, identity and assembly redshifts of simulated isolated and non-isolated elliptical galaxies are studied and compared. Observational and numerical data are used to compare age, mass and the colour-magnitude relation. Our results, based on simulation data, show that almost 7 per cent of all elliptical galaxies brighter than -19mag in B band can be classified as IfE galaxies. Results also show that isolated elliptical galaxies have a rather flat luminosity function; a number density of ~3 × 10-6h3Mpc-3mag-1, throughout their B-band magnitudes. IfE galaxies show bluer colours than non-isolated elliptical galaxies and they appear younger, in a statistical sense, according to their mass-weighted age. IfE galaxies also form and assemble at lower redshifts compared to non-isolated elliptical galaxies. About 46 per cent of IfE galaxies have undergone at least one major merging event in their formation history, while the same fraction is only ~33 per cent for non-isolated ellipticals. Almost all (~98 per cent) isolated elliptical galaxies show merging activity during their evolution, pointing towards the importance of mergers in the formation of IfE galaxies. The mean time of the last major merging is at z ~ 0.6 or 6Gyr ago for isolated ellipticals, while non-isolated ellipticals experience their last major merging significantly earlier at z ~ 1.1 or 8Gyr ago. After inspecting merger trees of simulated IfE galaxies, we conclude that three different, yet typical, formation mechanisms can be identified: solitude, coupling and cannibalism. Our results also predict a previously unobserved population of blue, dim and light galaxies that fulfil observational criteria to be classified as IfE galaxies. This separate population comprises

  15. Elliptical accretion disks in active galactic nuclei

    NASA Technical Reports Server (NTRS)

    Eracleous, Michael; Livio, Mario; Halpern, Jules P.; Storchi-Bergmann, Thaisa

    1995-01-01

    We present a calculation of the profiles of emission lines originating in a relativistic, eccentric disk, and show examples of the resulting model profiles. Our calculations are motivated by the fact that in about one-quarter of the double-peaked emission lines observed in radio-loud active galactic nuclei (and in the mildly active nucleus of NGC 1097), the red peak is stronger than the blue peak, which is contrary to the prediction of relativistic, circular disk models. Using the eccentric disk model we fit some of the observed profiles that cannot be fitted with a circular disk model. We propose two possible scenarios for the formation of an eccentric disk in an active galactic nucleus: (a) tidal perturbation of the disk around a supermassive black hole by a smaller binary companion, and (b) formation of an elliptical disk from the debris resulting from the tidal disruption of a star by the central black hole. In the former case we show that the eccentricity can be long-lived because of the presence of the binary companion. In the latter case, although the inner parts of the disk may circularize quickly, we estimate that the outer parts will maintain their eccentricity for times much longer than the local viscous time. We suggest that it may be possible to detect profile variability on much shorter timescales than those ranging from a decade to several centuries by comparing the evolution of the line profile with detailed model predictions. We argue that line-profile variability may also be the most promising discriminant among competing models for the origin of asymmetric, double-peaked emission lines.

  16. A massive star origin for an unusual helium-rich supernova in an elliptical galaxy.

    PubMed

    Kawabata, K S; Maeda, K; Nomoto, K; Taubenberger, S; Tanaka, M; Deng, J; Pian, E; Hattori, T; Itagaki, K

    2010-05-20

    The unusual helium-rich (type Ib) supernova SN 2005E is distinguished from all supernovae hitherto observed by its faint and rapidly fading light curve, prominent calcium lines in late-phase spectra and lack of any mark of recent star formation near the supernova location. These properties are claimed to be explained by a helium detonation in a thin surface layer of an accreting white dwarf. Here we report that the observed properties of SN 2005cz, which appeared in an elliptical galaxy, resemble those of SN 2005E. We argue that these properties are best explained by a core-collapse supernova at the low-mass end (8-12 solar masses) of the range of massive stars that explode. Such a low-mass progenitor lost its hydrogen-rich envelope through binary interaction, had very thin oxygen-rich and silicon-rich layers above the collapsing core, and accordingly ejected a very small amount of radioactive (56)Ni and oxygen. Although the host galaxy NGC 4589 is an elliptical, some studies have revealed evidence of recent star-formation activity, consistent with the core-collapse model. PMID:20485430

  17. Theoretical Predictions for Surface Brightness Fluctuations and Implications for Stellar Populations of Elliptical Galaxies

    NASA Astrophysics Data System (ADS)

    Liu, Michael C.; Charlot, Stéphane; Graham, James R.

    2000-11-01

    We compute theoretical predictions for surface brightness fluctuations (SBFs) of single-burst stellar populations (SSPs) using models optimized for this purpose. We present results over a wide range of ages (from 1 to 17 Gyr) and metallicities (from 1/200 to 2.5 times solar) and for a comprehensive set of ground-based and space-based optical and infrared bandpasses. Our models agree well with existing SBF observations of Milky Way globular clusters and elliptical galaxies. Our results also provide refined theoretical calibrations and k-corrections that are needed to use SBFs as standard candles. We suggest that SBF distance measurements can be improved by (1) using a filter around 1 μm to minimize the influence of stellar population variations, and (2) using the integrated V-K galaxy color instead of V-Ic to calibrate I-band SBF distances. In addition, we show that available SBF observations set useful constraints on current population synthesis models, and we suggest SBF-based tests for future models. The existing SBF data favor particular choices of stellar evolutionary tracks and spectral libraries among the several choices allowed by comparisons based on only the integrated properties of galaxies. Also, the tightness of the empirical I-band SBF calibration as a function of V-Ic galaxy color is a useful constraint. It suggests that the model uncertainties in the lifetimes of the post-main-sequence evolutionary phases are probably less than +/-50% and that the initial mass function in elliptical galaxies is probably not much steeper than that in the solar neighborhood. Finally, we analyze the potential of SBFs for probing unresolved stellar populations in elliptical galaxies. Since SBFs depend on the second moment of the stellar luminosity function, they are sensitive to the brightest giant stars and provide complementary information to commonly used integrated light and spectra. In particular, we find that optical/near-infrared SBFs are much more sensitive to

  18. Elliptic Cones Alone and with Wings at Supersonic Speed

    NASA Technical Reports Server (NTRS)

    Jorgensen, Leland H

    1958-01-01

    To help fill the gap in the knowledge of aerodynamics of shapes intermediate between bodies of revolution and flat triangular wings, force and moment characteristics for elliptic cones have been experimentally determined for Mach numbers of 1.97 and 2.94. Elliptic cones having cross-sectional axis ratios from 1 through 6 and with lengths and base areas equal to circular cones of fineness ratios 3.67 and 5 have been studied for angles of bank of 0 degree and 90 degrees. Elliptic and circular cones in combination with triangular wings of aspect ratios 1 and 1.5 also have been considered. The angle-of-attack range was from 0 degree to about 16 degrees, and the Reynolds number was 8 x 10(6), based on model length. In addition to the forces and moments at angle of attack, pressure distributions for elliptic cones at zero angle of attack have been determined. The results of this investigation indicate that there are distinct aerodynamic advantages to the use of elliptic cones.

  19. Applications of Elliptically Polarized, Few-Cycle Attosecond Pulses

    NASA Astrophysics Data System (ADS)

    Starace, Anthony F.

    2016-05-01

    Use of elliptically-polarized light opens the possibility of investigating effects that are not accessible with linearly-polarized pulses. This talk presents two new physical effects that are predicted for ionization of the helium atom by few-cycle, elliptically polarized attosecond pulses. For double ionization of He by an intense elliptically polarized attosecond pulse, we predict a nonlinear dichroic effect (i.e., the difference of the two-electron angular distributions in the polarization plane for opposite helicities of the ionizing pulse) that is sensitive to the carrier-envelope phase, ellipticity, peak intensity I, and temporal duration of the pulse. For single ionization of He by two oppositely circularly polarized, time-delayed attosecond pulses we predict that the photoelectron momentum distributions in the polarization plane have helical vortex structures that are exquisitely sensitive to the time-delay between the pulses, their relative phase, and their handedness. Both of these effects manifest the ability to control the angular distributions of the ionized electrons by means of the attosecond pulse parameters. Our predictions are obtained numerically by solving the six-dimensional two-electron time-dependent Schrödinger equation for the case of elliptically polarized attosecond pulses. They are interpreted analytically by means of perturbation theory analyses of the two ionization processes. This work is supported in part by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), Award No. DE-FG03-96ER14646.

  20. Broadband time-resolved elliptical crystal spectrometer for X-ray spectroscopic measurements in laser-produced plasmas

    NASA Astrophysics Data System (ADS)

    Wang, Rui-Rong; Jia, Guo; Fang, Zhi-Heng; Wang, Wei; Meng, Xiang-Fu; Xie, Zhi-Yong; Zhang, Fan

    2014-11-01

    The X-ray spectrometer used in high-energy-density plasma experiments generally requires both broad X-ray energy coverage and high temporal, spatial, and spectral resolutions for overcoming the difficulties imposed by the X-ray background, debris, and mechanical shocks. By using an elliptical crystal together with a streak camera, we resolve this issue at the SG-II laser facility. The carefully designed elliptical crystal has a broad spectral coverage with high resolution, strong rejection of the diffuse and/or fluorescent background radiation, and negligible source broadening for extended sources. The spectra that are Bragg reflected (23° < θ < 38°) from the crystal are focused onto a streak camera slit 18 mm long and about 80 μm wide, to obtain a time-resolved spectrum. With experimental measurements, we demonstrate that the quartz(1011) elliptical analyzer at the SG-II laser facility has a single-shot spectral range of (4.64-6.45) keV, a typical spectral resolution of E/ΔE = 560, and an enhanced focusing power in the spectral dimension. For titanium (Ti) data, the lines of interest show a distribution as a function of time and the temporal variations of the He-α and Li-like Ti satellite lines and their spatial profiles show intensity peak red shifts. The spectrometer sensitivity is illustrated with a temporal resolution of better than 25 ps, which satisfies the near-term requirements of high-energy-density physics experiments.

  1. Transition to turbulence in an elliptic vortex

    NASA Technical Reports Server (NTRS)

    Lundgren, Thomas S.; Mansour, N. N.

    1993-01-01

    We study the three dimensional instability and nonlinear growth of the two dimensional flow described by the stream function Psi = (A sin b1 x sin b2 y)/(b1(exp 2) + b2(exp 2)) where b1 = pi/L1, b2 = pi/L2. This is a swirling flow in a box which is bounded by 0 less than x less than L1, 0 less than y less than L2 and is infinite in the z direction. This flow is a solution of the Navier-Stokes equation with A = exp(-v(b1(exp 2) + b2(exp 2))t) which slowly decays. We seek a viscous solution which starts near this one and slips along but does not penetrate the bounding walls. The vorticity of the basic flow is w(sub z) = A sin b1 x sin b2 y which has maximum value A at the center of the box and drops to zero at the boundaries. We can think of the resulting flow as that of a captive vortex.

  2. Searching for FUV line emission from 107 K gas in massive elliptical galaxies and galaxy clusters as a tracer of turbulent velocities

    NASA Astrophysics Data System (ADS)

    Anderson, Michael E.; Sunyaev, Rashid

    2016-07-01

    Non-thermal pressure from turbulence and bulk flows is a fundamental ingredient in hot gaseous haloes, and in the intracluster medium, it will be measured through emission line kinematics with calorimeters on future X-ray spacecraft. In this paper, we present a complementary method for measuring these effects, using forbidden FUV emission lines of highly ionized Iron which trace 107 K gas. The brightest of these is [Fe XXI] λ1354.1. We search for these lines in archival Hubble Space Telescope (HST)-Cosmic Origins Spectrograph (COS) spectra from the well-known elliptical galaxies M87 and NGC4696, which harbor large reservoirs of 107 K gas. We report a 2.2σ feature which we attribute to [Fe XXI] from a filament in M87, and positive residuals in the nuclei of M87 and NGC4696, for which the 90 per cent upper limits on the line flux are close to the predicted fluxes based on X-ray observations. In a newer reduction of the data from the Hubble Spectroscopic Legacy Archive, these limits become tighter and the [Fe XXI] feature reaches a formal significance of 5.3σ, neglecting uncertainty in fitting the continuum. Using our constraints, we perform emission measure analysis, constraining the characteristic path length and column density of the ˜107 K gas. We also examine several sightlines towards filaments or cooling flows in other galaxy clusters, for which the fraction of gas at 107 K is unknown, and place upper limits on its emission measure in each case. A medium-resolution HST-COS observation of the M87 filament for ˜10 orbits would confirm our detection of [Fe XXI] and measure its width.

  3. Photographic spectra of fireballs

    NASA Astrophysics Data System (ADS)

    Borovička, J.

    2016-01-01

    Two methods of spectroscopy of meteors using image intensified video cameras and classical photographic film cameras are compared. Video cameras provide large number of low resolution spectra of meteors of normal brightness, which can be used for statistical studies. Large format film cameras have been used through the history and provide high resolution spectra, which can be used to derive temperature, density and absolute abundances of various elements in the radiating plasma. The sensitivity of films is, however, low and only spectra of bright meteors (fireballs) can be studied. Examples of photographic fireball spectra are provided.

  4. Crack spectra analysis

    SciTech Connect

    Tiernan, M.

    1980-09-01

    Crack spectra derived from velocity data have been shown to exhibit systematics which reflect microstructural and textural differences between samples (Warren and Tiernan, 1980). Further research into both properties and information content of crack spectra have yielded the following: Spectral features are reproducible even at low pressures; certain observed spectral features may correspond to non-in-situ crack populations created during sample retrieval; the functional form of a crack spectra may be diagnostic of the sample's grain texture; hysteresis is observed in crack spectra between up and down pressure runs - it may be due to friction between the faces of closed crack populations.

  5. Dynamical properties of the soft-wall elliptical billiard.

    PubMed

    Kroetz, Tiago; Oliveira, Hércules A; Portela, Jefferson S E; Viana, Ricardo L

    2016-08-01

    Physical systems such as optical traps and microwave cavities are realistically modeled by billiards with soft walls. In order to investigate the influence of the wall softness on the billiard dynamics, we study numerically a smooth two-dimensional potential well that has the elliptical (hard-wall) billiard as a limiting case. Considering two parameters, the eccentricity of the elliptical equipotential curves and the wall hardness, which defines the steepness of the well, we show that (1) whereas the hard-wall limit is integrable and thus completely regular, the soft wall elliptical billiard exhibits chaos, (2) the chaotic fraction of the phase space depends nonmonotonically on the hardness of the wall, and (3) the effect of the hardness on the dynamics depends strongly on the eccentricity of the billiard. We further show that the limaçon billiard can exhibit enhanced chaos induced by wall softness, which suggests that our findings generalize to quasi-integrable systems. PMID:27627309

  6. Cluster flight control for fractionated spacecraft on an elliptic orbit

    NASA Astrophysics Data System (ADS)

    Xu, Ming; Liang, Yuying; Tan, Tian; Wei, Lixin

    2016-08-01

    This paper deals with the stabilization of cluster flight on an elliptic reference orbit by the Hamiltonian structure-preserving control using the relative position measurement only. The linearized Melton's relative equation is utilized to derive the controller and then the full nonlinear relative dynamics are employed to numerically evaluate the controller's performance. In this paper, the hyperbolic and elliptic eigenvalues and their manifolds are treated without distinction notations. This new treatment not only contributes to solving the difficulty in feedback of the unfixed-dimensional manifolds, but also allows more opportunities to set the controlled frequencies of foundational motions or to optimize control gains. Any initial condition can be stabilized on a Kolmogorov-Arnold-Moser torus near a controlled elliptic equilibrium. The motions are stabilized around the natural relative trajectories rather than track a reference relative configuration. In addition, the bounded quasi-periodic trajectories generated by the controller have advantages in rapid reconfiguration and unpredictable evolution.

  7. Elliptic surface grid generation on minimal and parametrized surfaces

    NASA Technical Reports Server (NTRS)

    Spekreijse, S. P.; Nijhuis, G. H.; Boerstoel, J. W.

    1995-01-01

    An elliptic grid generation method, which generates boundary conforming grids in a two dimensional physical space, is presented. The method is based on the composition of an algebraic and elliptic transformation. The composite mapping obeys the Poisson grid generation system with control functions specified by the algebraic transformation. It is shown that the grid generation on a minimal surface in a three dimensional space is equivalent to the grid generation in a two dimensional domain in physical space. A second elliptic grid generation method, which generates boundary conforming grids on smooth surfaces, is presented. Concerning surface modeling, it is shown that bicubic Hermit interpolation is an excellent method to generate a smooth surface crossing a discrete set of control points.

  8. Ball bearing lubrication: The elastohydrodynamics of elliptical contacts

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.; Dowson, D.

    1981-01-01

    The history of ball bearings is examined, taking into account rollers and the wheel in the early civilizations, the development of early forms of rolling-element bearings in the classical civilizations, the Middle Ages, the Industrial Revolution, the emergence of the precision ball bearing, scientific studies of contact mechanics and rolling friction, and the past fifty years. An introduction to ball bearings is presented, and aspects of ball bearing mechanics are explored. Basic characteristics of lubrication are considered along with lubrication equations, the lubrication of rigid ellipsoidal solids, and elastohydrodynamic lubrication theory. Attention is given to the theoretical results for fully flooded elliptical hydrodynamic contacts, the theoretical results for starved elliptical contacts, experimental investigations, the elastohydrodynamics of elliptical contacts for materials of low elastic modulus, the film thickness for different regimes of fluid-film lubrication, and applications.

  9. Precession and circularization of elliptical space-tether motion

    NASA Technical Reports Server (NTRS)

    Chapel, Jim D.; Grosserode, Patrick

    1993-01-01

    In this paper, we present a simplified analytic model for predicting motion of long space tethers. The perturbation model developed here addresses skip rope motion, where each end of the tether is held in place and the middle of the tether swings with a motion similar to that of a child's skip rope. If the motion of the tether midpoint is elliptical rather than circular, precession of the ellipse complicates the procedures required to damp this motion. The simplified analytic model developed in this paper parametrically predicts the precession of elliptical skip rope motion. Furthermore, the model shows that elliptic skip rope motion will circularize when damping is present in the longitudinal direction. Compared with high-fidelity simulation results, this simplified model provides excellent predictions of these phenomena.

  10. Magnetohydrodynamics equilibrium of a self-confined elliptical plasma ball

    SciTech Connect

    Wu, H. P. O. Box 8730, Beijing 100080 and Institute of Mechanics, Academia Sinica, Beijing, People's Republic of China ); Oakes, M.E. )

    1991-08-01

    A variational principle is applied to the problem of magnetohydrodynamics (MHD) equilibrium of a self-contained elliptical plasma ball, such as elliptical ball lightning. The principle is appropriate for an approximate solution of partial differential equations with arbitrary boundary shape. The method reduces the partial differential equation to a series of ordinary differential equations and is especially valuable for treating boundaries with nonlinear deformations. The calculations conclude that the pressure distribution and the poloidal current are more uniform in an oblate self-confined plasma ball than that of an elongated plasma ball. The ellipticity of the plasma ball is obviously restricted by its internal pressure, magnetic field, and ambient pressure. Qualitative evidence is presented for the absence of sighting of elongated ball lightning.

  11. Cluster flight control for fractionated spacecraft on an elliptic orbit

    NASA Astrophysics Data System (ADS)

    Xu, Ming; Liang, Yuying; Tan, Tian; Wei, Lixin

    2016-04-01

    This paper deals with the stabilization of cluster flight on an elliptic reference orbit by the Hamiltonian structure-preserving control using the relative position measurement only. The linearized Melton's relative equation is utilized to derive the controller and then the full nonlinear relative dynamics are employed to numerically evaluate the controller's performance. In this paper, the hyperbolic and elliptic eigenvalues and their manifolds are treated without distinction notations. This new treatment not only contributes to solving the difficulty in feedback of the unfixed-dimensional manifolds, but also allows more opportunities to set the controlled frequencies of foundational motions or to optimize control gains. Any initial condition can be stabilized on a Kolmogorov-Arnold-Moser torus near a controlled elliptic equilibrium. The motions are stabilized around the natural relative trajectories rather than track a reference relative configuration. In addition, the bounded quasi-periodic trajectories generated by the controller have advantages in rapid reconfiguration and unpredictable evolution.

  12. Systematic differences between the field and cluster elliptical galaxies

    NASA Technical Reports Server (NTRS)

    De Carvalho, R. R.; Djorgovski, S.

    1992-01-01

    Multivariate statistical techniques and fundamental plane fits are used here to study possible systematic differences between field ellipticals (FEs) and cluster ellipticals (CEs). The FEs show more intrinsic scatter in their properties, especially when stellar population variables are included. Pairwise correlations for the two samples are different; the correlations are systematically better for the cluster sample, meaning that ellipticals in the two samples populate their fundamental planes in different ways. Bivariate correlations are different for the two samples, implying that they have different fundamental planes. This is especially true for the correlations which include the population variables Mg2 and (B-V), which are sensitive both to the enrichment history and the storm formation history.

  13. Questions on Pure Luminosity Evolution for Elliptical Galaxies

    NASA Astrophysics Data System (ADS)

    He, Ping; Zhang, Yuan-Zhong

    1999-02-01

    The explanation for the existence of an excess population of faint blue galaxies (FBGs) has been a mystery for nearly two decades and remains one of the grand astronomical issues to date. Existing models cannot explain all of the observational data, such as galaxy number counts in the optical and infrared passbands and the redshift distributions of galaxies. Here, by modeling the morphological number counts derived from the Hubble Space Telescope, as well as the number counts in optical and infrared passbands and the redshift and color distributions of galaxies obtained from ground-based observations, we show that the ``FBG problem'' cannot be resolved if elliptical galaxies are assumed to have formed in an instantaneous burst of star formation at high redshift with no subsequent star formation events, which is the conventional scenario for formation and evolution of ellipticals. There exist great discrepancies between the observed B-K color distribution and the predicted distribution for ellipticals by such a pure luminosity evolution (PLE) model in the context of the conventional scenario. Neither can the mild evolution (i.e., the star formation events have lasted for a longer time than those of the instantaneous burst and passive evolution since the formation of galaxies) for ellipticals be accepted in the context of PLE assumption. The introduction of dust extinction also cannot save the PLE models. This conclusion holds for each of the three cosmological models under consideration: flat, open, and Λ-dominated. Hence, our investigation suggests that PLE assumption for elliptical galaxies is questionable, and number evolution may be essential for ellipticals.

  14. Effects of Forsterite Grain Shape on Infrared Spectra

    NASA Astrophysics Data System (ADS)

    Koike, C.; Imai, Y.; Chihara, H.; Suto, H.; Murata, K.; Tsuchiyama, A.; Tachibana, S.; Ohara, S.

    2010-02-01

    The Infrared Space Observatory (ISO) detected several sharp infrared features around young stars, comets, and evolved stars. These sharp features were identified as Mg-rich crystalline silicates of forsterite and enstatite by comparison with spectra from laboratory data. However, certain infrared emission bands in the observed spectra cannot be identified because they appear at slightly shorter wavelengths than the peaks in forsterite laboratory spectra, where the shapes of forsterite particles are irregular. To solve this problem, we measured infrared spectra of forsterite grains of various shapes (irregular, plate-like with no sharp edges, elliptical, cauliflower, and spherical) in the infrared spectral region between 5 and 100 μm. The spectra depend on particle shape. The spectra of the 11, 19, 23, and 33 μm bands, in particular, are extremely sensitive to particle shape, whereas some peaks such as the 11.9, 49, and 69 μm bands remained almost unchanged despite different particle shapes. This becomes most evident from the spectra of near-spherical particles produced by annealing an originally amorphous silicate sample at temperature from 600 to 1150°C. The spectra of these samples differ strongly from those of other ones, showing peaks at much shorter wavelengths. At a higher annealing temperature of 1200°C, the particle shapes changed drastically from spherical to irregular and the spectra became similar to those of forsterite particles with irregular shapes. Based on ISO data and other observational data, the spectra of outflow sources and disk sources may correspond to differences in forsterite shape, and further some unidentified peaks, such as those at 32.8 or 32.5 μm, may be due to spherical or spherical-like forsterite.

  15. EFFECTS OF FORSTERITE GRAIN SHAPE ON INFRARED SPECTRA

    SciTech Connect

    Koike, C.; Imai, Y.; Chihara, H.; Murata, K.; Tsuchiyama, A.; Suto, H.; Tachibana, S.; Ohara, S.

    2010-02-01

    The Infrared Space Observatory (ISO) detected several sharp infrared features around young stars, comets, and evolved stars. These sharp features were identified as Mg-rich crystalline silicates of forsterite and enstatite by comparison with spectra from laboratory data. However, certain infrared emission bands in the observed spectra cannot be identified because they appear at slightly shorter wavelengths than the peaks in forsterite laboratory spectra, where the shapes of forsterite particles are irregular. To solve this problem, we measured infrared spectra of forsterite grains of various shapes (irregular, plate-like with no sharp edges, elliptical, cauliflower, and spherical) in the infrared spectral region between 5 and 100 mum. The spectra depend on particle shape. The spectra of the 11, 19, 23, and 33 mum bands, in particular, are extremely sensitive to particle shape, whereas some peaks such as the 11.9, 49, and 69 mum bands remained almost unchanged despite different particle shapes. This becomes most evident from the spectra of near-spherical particles produced by annealing an originally amorphous silicate sample at temperature from 600 to 1150 deg. C. The spectra of these samples differ strongly from those of other ones, showing peaks at much shorter wavelengths. At a higher annealing temperature of 1200 deg. C, the particle shapes changed drastically from spherical to irregular and the spectra became similar to those of forsterite particles with irregular shapes. Based on ISO data and other observational data, the spectra of outflow sources and disk sources may correspond to differences in forsterite shape, and further some unidentified peaks, such as those at 32.8 or 32.5 mum, may be due to spherical or spherical-like forsterite.

  16. A numerical study of magneto-hydrodynamic free convection in a square cavity with heated elliptic block

    NASA Astrophysics Data System (ADS)

    Munshi, M. Jahirul Haque; Alim, M. A.; Bhuiyan, A. H.

    2016-07-01

    The problem of Magneto-hydrodynamic (MHD) field on buoyancy-driven free convection heat transfer in a square cavity with heated elliptic block at the centre has been investigated in this work. The governing differential equations are solved by using finite element method (Galerkin weighted residual method). The lower wall is adiabatic. The left wall is kept at heated Th. The right and upper wall is kept at cold Tc respectively. Also all the wall are assumed to be no-slip condition. The study is performed for different Rayleigh and Hartmann numbers. A heated elliptic block is located at the centre of the cavity. The object of this study is to describe the effects of MHD on the field of buoyancy-driven and flow in presence of such heated block by visualization of graph. The results are illustrated with the streamlines, isotherms, velocity and temperature fields as well as local Nusselt number.

  17. Non-linear tides in a homogeneous rotating planet or star: global modes and elliptical instability

    NASA Astrophysics Data System (ADS)

    Barker, Adrian J.; Braviner, Harry J.; Ogilvie, Gordon I.

    2016-06-01

    We revisit the global modes and instabilities of homogeneous rotating ellipsoidal fluid masses, which are the simplest global models of rotationally and tidally deformed gaseous planets or stars. The tidal flow in a short-period planet may be unstable to the elliptical instability, a hydrodynamic instability that can drive tidal evolution. We perform a global (and local WKB) analysis to study this instability using the elegant formalism of Lebovitz & Lifschitz. We survey the parameter space of global instabilities with harmonic orders ℓ ≤ 5, for planets with spins that are purely aligned (prograde) or anti-aligned (retrograde) with their orbits. In general, the instability has a much larger growth rate if the planetary spin and orbit are anti-aligned rather than aligned. We have identified a violent instability for anti-aligned spins outside of the usual frequency range for the elliptical instability (when n/Ω ≲ -1, where n and Ω are the orbital and spin angular frequencies, respectively) if the tidal amplitude is sufficiently large. We also explore the instability in a rigid ellipsoidal container, which is found to be quantitatively similar to that with a realistic free surface. Finally, we study the effect of rotation and tidal deformation on mode frequencies. We find that larger rotation rates and larger tidal deformations both decrease the frequencies of the prograde sectoral surface gravity modes. This increases the prospect of their tidal excitation, potentially enhancing the tidal response over expectations from linear theory. In a companion paper, we use our results to interpret global simulations of the elliptical instability.

  18. Modifications of bundles, elliptic integrable systems, and related problems

    NASA Astrophysics Data System (ADS)

    Zotov, A. V.; Smirnov, A. V.

    2013-10-01

    We describe a construction of elliptic integrable systems based on bundles with nontrivial characteristic classes, especially attending to the bundle-modification procedure, which relates models corresponding to different characteristic classes. We discuss applications and related problems such as the Knizhnik-Zamolodchikov-Bernard equations, classical and quantum R-matrices, monopoles, spectral duality, Painlevé equations, and the classical-quantum correspondence. For an SL(N,ℂ)-bundle on an elliptic curve with nontrivial characteristic classes, we obtain equations of isomonodromy deformations.

  19. Study of medium beta elliptical cavities for CADS

    NASA Astrophysics Data System (ADS)

    Wen, Liangjian; Zhang, Shenghu; Li, Yongming; Wang, Ruoxu; Guo, Hao; Zhang, Cong; Jia, Huan; Jiang, Tiancai; Li, Chunlong; He, Yuan

    2016-02-01

    The China Accelerator-Driven Sub-critical System (CADS) is a high intensity proton facility to dispose of nuclear waste and generate electric power. CADS is based on a 1.5 GeV, 10 mA CW superconducting (SC) linac as a driver. The high energy section of the linac is composed of two families of SC elliptical cavities which are designed with geometrical beta 0.63 and 0.82. In this paper, the 650 MHz β=0.63 SC elliptical cavity is studied, including cavity optimization, multipacting, high order modes (HOMs) and generator RF power calculation. Supported by National Natural Science Foundation of China (91426303)

  20. Plastic Deformation in Profile-Coated Elliptical KB Mirrors

    DOE PAGESBeta

    Liu, Chian; Conley, R.; Qian, J.; Kewish, C. M.; Liu, W.; Assoufid, L.; Macrander, A. T.; Ice, G. E.; Tischler, J. Z.

    2012-01-01

    Profile coating has been successfully applied to produce elliptical Kirkpatrick-Baez (KB) mirrors using both cylindrical and flat Si substrates. Previously, focusing widths of 70 nm with 15-keV monochromatic and 80 nm with white beam were achieved using a flat Si substrate. Now, precision elliptical KB mirrors with sub-nm figure errors are produced with both Au and Pt coatings on flat substrates. Recent studies of bare Si-, Au-, and Pt-coated KB mirrors under prolonged synchrotron X-ray radiation and low-temperature vacuum annealing will be discussed in terms of film stress relaxation and Si plastic deformation.

  1. On the Dirichlet problem for a nonlinear elliptic equation

    NASA Astrophysics Data System (ADS)

    Egorov, Yu V.

    2015-04-01

    We prove the existence of an infinite set of solutions to the Dirichlet problem for a nonlinear elliptic equation of the second order. Such a problem for a nonlinear elliptic equation with Laplace operator was studied earlier by Krasnosel'skii, Bahri, Berestycki, Lions, Rabinowitz, Struwe and others. We study the spectrum of this problem and prove the weak convergence to 0 of the sequence of normed eigenfunctions. Moreover, we obtain some estimates for the 'Fourier coefficients' of functions in W^1p,0(Ω). This allows us to improve the preceding results. Bibliography: 8 titles.

  2. Plastic deformation in profile-coated elliptical KB mirrors

    SciTech Connect

    Liu, Chian; Conley, R.; Qian, J; Kewish, C. M.; Liu, Wenjun; Assoufid, Lahsen; Macrander, Albert T.; Ice, Gene E; Tischler, Jonathan

    2012-01-01

    Profile coating has been successfully applied to produce elliptical Kirkpatrick-Baez (KB) mirrors using both cylindrical and flat Si substrates. Previously, focusing widths of 70 nm with 15-keV monochromatic and 80 nm with white beam were achieved using a flat Si substrate. Now precision elliptical KB mirrors with sub-nm figure errors are produced with both Au and Pt coatings on flat substrates. Recent studies of bare Si, Au-, and Pt-coated KB mirrors under prolonged synchrotron x-ray radiation and low-temperature vacuum annealing will be discussed in terms of film-stress relaxation and Si plastic deformation.

  3. Centaurus A galaxy, type EO peculiar elliptical, also radio source

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Centaurus A galaxy, type EO peculiar elliptical, also radio source. CTIO 4-meter telescope, 1975. NGC 5128, a Type EO peculiar elliptical galaxy in the constellation Centaurus. This galaxy is one of the most luminous and massive galaxies known and is a strong source of both radio and X-ray radiation. Current theories suggest that the nucleus is experiencing giant explosions involving millions of stars and that the dark band across the galactic disk is material being ejected outward. Cerro Toloto 4-meter telescope photo. Photo credit: National Optical Astronomy Observatories

  4. Energy spectra in bubbly turbulence

    NASA Astrophysics Data System (ADS)

    Luther, Stefan; van den Berg, Thomas H.; Rensen, Judith; Lohse, Detlef

    2004-11-01

    The energy spectrum of single phase turbulent flow - apart from intermittency corrections - has been known since Kolomogorov 1941, E(k) ∝ k-5/3. How do bubbles modify this spectrum? To answer this question, we inject micro bubbles (radius 100 μm) in fully turbulent flow (Re_λ=200) up to volume concentrations of 0.3 %. Energy spectra and velocity structure functions are measured with hot-film anemometry. Under our experimental conditions, we find an enhancement of energy on small scales confirming numerical predictions by Mazzitelli, Lohse, and Toschi [Phys. Fluids 15, L5 (2003)]. They propose a mechanism in which bubbles are clustering most likely in downflow regions. This clustering is a lift force effect suppressing large vortical structures, while enhancing energy input on small scales.

  5. Optics ellipticity performance of an unobscured off-axis space telescope.

    PubMed

    Zeng, Fei; Zhang, Xin; Zhang, Jianping; Shi, Guangwei; Wu, Hongbo

    2014-10-20

    With the development of astronomy, more and more attention is paid to the survey of dark matter. Dark matter cannot be seen directly but can be detected by weak gravitational lensing measurement. Ellipticity is an important parameter used to define the shape of a galaxy. Galaxy ellipticity changes with weak gravitational lensing and nonideal optics. With our design of an unobscured off-axis telescope, we implement the simulation and calculation of optics ellipticity. With an accurate model of optics PSF, the characteristic of ellipticity is modeled and analyzed. It is shown that with good optical design, the full field ellipticity can be quite small. The spatial ellipticity change can be modeled by cubic interpolation with very high accuracy. We also modeled the ellipticity variance with time and analyzed the tolerance. It is shown that the unobscured off-axis telescope has good ellipticity performance and fulfills the requirement of dark matter survey. PMID:25401561

  6. A new weak lensing shear analysis method using ellipticity defined by 0th order moments

    NASA Astrophysics Data System (ADS)

    Okura, Yuki; Futamase, Toshifumi

    2015-04-01

    We developed a new method that uses ellipticity defined by 0th order moments (0th-ellipticity) for weak gravitational lensing shear analysis. Although there is a strong correlation between the ellipticity calculated using this approach and the usual ellipticity defined by the 2nd order moment, the ellipticity calculated here has a higher signal-to-noise ratio because it is weighted to the central region of the image. These results were confirmed using data for Abell 1689 from the Subaru telescope. For shear analysis, we adopted the ellipticity of re-smeared artificial image method for point spread function correction, and we tested the precision of this 0th-ellipticity with simple simulation, then we obtained the same level of precision with the results of ellipticity defined by quadrupole moments. Thus, we can expect that weak lensing analysis using 0 shear will be improved in proportion to the statistical error.

  7. Action spectra again?

    PubMed

    Coohill, T P

    1991-11-01

    Action spectroscopy has a long history and is of central importance to photobiological studies. Action spectra were among the first assays to point to chlorophyll as the molecule most responsible for plant growth and to DNA as the genetic material. It is useful to construct action spectra early in the investigation of new areas of photobiological research in an attempt to determine the wavelength limits of the radiation region causing the studied response. But due to the severe absorption of ultraviolet (UV) radiation by biological samples, UV action spectra were first limited to small cells (bacteria and fungi). Advances in techniques (e.g. single cell culture) and analysis allowed accurate action spectra to be reported even for mammalian cells. But precise analytical action spectra are often difficult to obtain when large, pigmented, or groups of cells are investigated. Here some action spectra are limited in interpretation and merely supply a wavelength vs effect curve. When polychromatic sources are employed, the interpretation of action spectra is even more complex and formidable. But such polychromatic action spectra can be more directly related to ambient responses. Since precise action spectra usually require the completion of a relatively large number of careful experiments using somewhat sophisticated equipment over a range of at least six wavelengths, they are often not pursued. But they remain central to the elucidation of the effect being studied. The worldwide community has agreed that stratospheric ozone is depleting, with the possibility of a consequent rise in the amount of UV-B (290-320 nm) reaching the earth's surface. It is therefore essential that new action spectra be completed for UV-B effects on a large variety of responses of human, animal, and aquatic plant systems. Combining these action spectra with the known amounts of UV-B reaching the biosphere can give rise to solar UV effectiveness spectra that, in turn, can give rise to estimates

  8. On the spectral accuracy of a fictitious domain method for elliptic operators in multi-dimensions

    NASA Astrophysics Data System (ADS)

    Le Penven, Lionel; Buffat, Marc

    2012-10-01

    This work is a continuation of the authors efforts to develop high-order numerical methods for solving elliptic problems with complex boundaries using a fictitious domain approach. In a previous paper, a new method was proposed, based on the use of smooth forcing functions with identical shapes, mutually disjoint supports inside the fictitious domain and whose amplitudes play the role of Lagrange multipliers in relation to a discrete set of boundary constraints. For one-dimensional elliptic problems, this method shows spectral accuracy but its implementation in two dimensions seems to be limited to a fourth-order algebraic convergence rate. In this paper, a spectrally accurate formulation is presented for multi-dimensional applications. Instead of being specified locally, the forcing function is defined as a convolution of a mollifier (smooth bump function) and a Lagrange multiplier function (the amplitude of the bump). The multiplier function is then approximated by Fourier series. Using a Fourier Galerkin approximation, the spectral accuracy is demonstrated on a two-dimensional Laplacian problem and on a Stokes flow around a periodic array of cylinders. In the latter, the numerical solution achieves the same high-order accuracy as a Stokes eigenfunction expansion and is much more accurate than the solution obtained with a classical third order finite element approximation using the same number of degrees of freedom.

  9. Heat transfer enhancement of PCM melting in 2D horizontal elliptical tube using metallic porous matrix

    NASA Astrophysics Data System (ADS)

    Jourabian, Mahmoud; Farhadi, Mousa; Rabienataj Darzi, Ahmad Ali

    2016-07-01

    In this study, the melting process of ice as a phase-change material (PCM) saturated with a nickel-steel porous matrix inside a horizontal elliptical tube is investigated. Due to the low thermal conductivity of the PCM, it is motivated to augment the heat transfer performance of the system simultaneously by finding an optimum value of the aspect ratio and impregnating a metallic porous matrix into the base PCM. The lattice Boltzmann method with a double distribution function formulated based on the enthalpy method, is applied at the representative elementary volume scale under the local thermal equilibrium assumption between the PCM and porous matrix in the composite. While reducing or increasing the aspect ratio of the circular tubes leads to the expedited melting, the 90° inclination of each elliptical tube in the case of the pure PCM melting does not affect the melting rate. With the reduction in the porosity, the effective thermal conductivity and melting rate in all tubes promoted. Although the natural convection is fully suppressed due to the significant flow blockage in the porous structure, the melting rates are generally increased in all cases.

  10. Lagrangian coherent structures in the planar elliptic restricted three-body problem

    NASA Astrophysics Data System (ADS)

    Gawlik, Evan S.; Marsden, Jerrold E.; Du Toit, Philip C.; Campagnola, Stefano

    2009-03-01

    This study investigates Lagrangian coherent structures (LCS) in the planar elliptic restricted three-body problem (ER3BP), a generalization of the circular restricted three-body problem (CR3BP) that asks for the motion of a test particle in the presence of two elliptically orbiting point masses. Previous studies demonstrate that an understanding of transport phenomena in the CR3BP, an autonomous dynamical system (when viewed in a rotating frame), can be obtained through analysis of the stable and unstable manifolds of certain periodic solutions to the CR3BP equations of motion. These invariant manifolds form cylindrical tubes within surfaces of constant energy that act as separatrices between orbits with qualitatively different behaviors. The computation of LCS, a technique typically applied to fluid flows to identify transport barriers in the domains of time-dependent velocity fields, provides a convenient means of determining the time-dependent analogues of these invariant manifolds for the ER3BP, whose equations of motion contain an explicit dependency on the independent variable. As a direct application, this study uncovers the contribution of the planet Mercury to the Interplanetary Transport Network, a network of tubes through the solar system that can be exploited for the construction of low-fuel spacecraft mission trajectories.

  11. Hot gas metallicity and the history of supernova activity in elliptical galaxies

    NASA Technical Reports Server (NTRS)

    Loewenstein, Michael; Mathews, William G.

    1991-01-01

    Calculations of the dynamical evolution of the hot interstellar medium (ISM) in a massive elliptical galaxy are described, with a variety of past variations of the SN rate being assumed. The investigation focuses on iron enrichment in the ISM. The equivalent widths of the 6.7-keV iron line are calculated as a function of redshift and of galactic projected radius. The present-day interstellar gas in elliptical galaxies contains a fossil record of past SN activity that can be determined from measurements of iron line equivalent widths at several projected radii in the galaxy. It is proposed that the ISM iron abundance is likely to be quite inhomogeneous. The hydrogen-free ejecta of type Ia SN also result in pronounced ISM abundance inhomogeneities that probably eventually cool and move in pressure equilibrium with the local ISM flow velocity. The 6.7-keV iron line emission is greater if the iron is confined to ionized regions of pure iron.

  12. Spectroscopic ellipsometer based on direct measurement of polarization ellipticity

    SciTech Connect

    Watkins, Lionel R.

    2011-06-20

    A polarizer-sample-Wollaston prism analyzer ellipsometer is described in which the ellipsometric angles {psi} and {Delta} are determined by direct measurement of the elliptically polarized light reflected from the sample. With the Wollaston prism initially set to transmit p- and s-polarized light, the azimuthal angle P of the polarizer is adjusted until the two beams have equal intensity. This condition yields {psi}={+-}P and ensures that the reflected elliptically polarized light has an azimuthal angle of {+-}45 deg. and maximum ellipticity. Rotating the Wollaston prism through 45 deg. and adjusting the analyzer azimuth until the two beams again have equal intensity yields the ellipticity that allows {Delta} to be determined via a simple linear relationship. The errors produced by nonideal components are analyzed. We show that the polarizer dominates these errors but that for most practical purposes, the error in {psi} is negligible and the error in {Delta} may be corrected exactly. A native oxide layer on a silicon substrate was measured at a single wavelength and multiple angles of incidence and spectroscopically at a single angle of incidence. The best fit film thicknesses obtained were in excellent agreement with those determined using a traditional null ellipsometer.

  13. Ellipticity of Rayleigh waves and crustal structure in northern Italy

    NASA Astrophysics Data System (ADS)

    Berbellini, Andrea; Morelli, Andrea; Ferreira, Ana M. G.

    2016-04-01

    Horizontal-to-vertical amplitude ratio of elliptically-polarised ground motion of Rayleigh waves depends on the local crustal structure. Its measurement therefore adds another, seldom used, tool to image shallow earth structure. Frequency-dependent sensitivity kernels are dominated by shear-wave velocity and are rather shallow, so they are a convenient tool to model sedimentary layers that nicely complement surface wave studies. We perform extensive measurements, in the period range between 10 and 110 s, on traces from about 500 globally-distributed earthquakes, occurred in years 2008 ÷ 2014, recorded by 95 stations in northern Italy - - a region including the wide basin of the Po Plain and encircling Alps and northern Apennines. The observations are well correlated with known strucure: high ellipticity correlates well with low seismic velocity (such as in the Po Plain), and low ellipticity corresponds to fast seismic velocity in hard rock environments in correspondence of Alps and Apennines. Comparison between observations and predicted ellipticity from a reference crustal model of the region (Molinari et al., 2015) shows substantial fit. Sensitivity to vS is quite non linear, but inversion is possible and may provide very useful complementary information to, e.g., surface wave phase or group velocity or receiver functions.

  14. Molecular gas in elliptical galaxies with dust lanes

    NASA Technical Reports Server (NTRS)

    Wang, Zhong; Kenney, Jeffrey D. P.; Ishizuki, Sumio

    1992-01-01

    We have searched for CO(1-0) line emission in eight dust lane elliptical and lenticular galaxies using the Nobeyama 45 m telescope. Five of the eight galaxies, including the well-studied elliptical NGC 1052, have CO emission at above the 5-sigma level, with inferred molecular gas masses ranging from 10 exp 8 to a few times 10 exp 9 solar masses. Our selection criterion differs from previous surveys in that it does not depend on the FIR fluxes, and thus is less sensitive to the sizes and distances of the host galaxies or to the degree to which dust is heated. The relatively high detection rate of CO in these ellipticals suggests a close correlation between molecular mass and cold dust. Compared with previously studied samples of FIR selected early-type galaxies, our sample has on average four times more CO emission per unit FIR (40-120 microns) luminosity. If the intrinsic gas-to-dust ratio of these galaxies as similar to that of the Milky Way, then only about 5 percent of the dust mass in dust lane ellipticals radiates substantially at 60 and 100 microns, and the remaining dust must be colder than about 30 K.

  15. The dynamical fingerprint of core scouring in massive elliptical galaxies

    SciTech Connect

    Thomas, J.; Saglia, R. P.; Bender, R.; Erwin, P.; Fabricius, M.

    2014-02-10

    The most massive elliptical galaxies have low-density centers or cores that differ dramatically from the high-density centers of less massive ellipticals and bulges of disk galaxies. These cores have been interpreted as the result of mergers of supermassive black hole binaries, which depopulate galaxy centers by gravitationally slingshotting central stars toward large radii. Such binaries naturally form in mergers of luminous galaxies. Here, we analyze the population of central stellar orbits in 11 massive elliptical galaxies that we observed with the integral field spectrograph SINFONI at the European Southern Observatory Very Large Telescope. Our dynamical analysis is orbit-based and includes the effects of a central black hole, the mass distribution of the stars, and a dark matter halo. We show that the use of integral field kinematics and the inclusion of dark matter is important to conclude on the distribution of stellar orbits in galaxy centers. Six of our galaxies are core galaxies. In these six galaxies, but not in the galaxies without cores, we detect a coherent lack of stars on radial orbits in the core region and a uniform excess of radial orbits outside of it: when scaled by the core radius r{sub b} , the radial profiles of the classical anisotropy parameter β(r) are nearly identical in core galaxies. Moreover, they quantitatively match the predictions of black hole binary simulations, providing the first convincing dynamical evidence for core scouring in the most massive elliptical galaxies.

  16. Elliptical galaxies kinematics within general relativity with renormalization group effects

    SciTech Connect

    Rodrigues, Davi C.

    2012-09-01

    The renormalization group framework can be applied to Quantum Field Theory on curved space-time, but there is no proof whether the beta-function of the gravitational coupling indeed goes to zero in the far infrared or not. In a recent paper [1] we have shown that the amount of dark matter inside spiral galaxies may be negligible if a small running of the General Relativity coupling G is present (δG/G{sub 0}∼<10{sup −7} across a galaxy). Here we extend the proposed model to elliptical galaxies and present a detailed analysis on the modeling of NGC 4494 (an ordinary elliptical) and NGC 4374 (a giant elliptical). In order to compare our results to a well known alternative model to the standard dark matter picture, we also evaluate NGC 4374 with MOND. In this galaxy MOND leads to a significative discrepancy with the observed velocity dispersion curve and has a significative tendency towards tangential anisotropy. On the other hand, the approach based on the renormalization group and general relativity (RGGR) could be applied with good results to these elliptical galaxies and is compatible with lower mass-to-light ratios (of about the Kroupa IMF type)

  17. Towards a cladistics of double Yangians and elliptic algebras*

    NASA Astrophysics Data System (ADS)

    Arnaudon, D.; Avan, J.; Frappat, L.; Ragoucy, E.; Rossi, M.

    2000-09-01

    A self-contained description of algebraic structures, obtained by combinations of various limit procedures applied to vertex and face sl(2) elliptic quantum affine algebras, is given. New double Yangian structures of dynamical type are defined. Connections between these structures are established. A number of them take the form of twist-like actions. These are conjectured to be evaluations of universal twists.

  18. Triangularity effects on the collisional diffusion for elliptic tokamaks

    NASA Astrophysics Data System (ADS)

    Martín, Pablo; Castro, Enrique

    2015-09-01

    The effect of ellipticity and triangularity will be analyzed for axisymmetric tokamak in the collisional regime. Analytic forms for the magnetic field cross sections are taken from those derived recently by other authors. Analytic results can be obtained in elliptic plasmas with triangularity by using an special system of tokamak coordinates previously published. Our results show that triangularities smaller than 0.6 increase confinement for ellipticities in the range 1.2-2. This behavior happens for negative and positive triangularities, however this effect is stronger for negative than for positive triangularities. The maximum diffusion velocity is not obtained for zero triangularity, but for small negative triangularities. Ellipticity is also very important in confinement, but the effect of triangularity seems to be more important. High electric inductive fields increase confinement, though this field is difficult to modify once the tokamak has been built. The analytic form of the current produced by this field is like that of a weak Ware pinch with an additional factor, which weakens the effect by an order of magnitude. The dependence of the triangularity effect with the Shafranov shift is also analyzed.

  19. The infrared emission from the elliptical galaxy NGC 1052

    NASA Technical Reports Server (NTRS)

    Becklin, E. E.; Tokunaga, A. T.; Wynn-Williams, C. G.

    1982-01-01

    Multi-aperture IR photometry of the elliptical galaxy NGC 1052 shows that its IR excess is confined to a region smaller than 2 arc sec (300 pc) in diameter coincident with the visible nucleus. It is suggested that the emission in the 5-20 micron range arises from dust heated by the nonthermal source seen at other wavelengths.

  20. Shielding of elliptic guides with direct sight to the moderator

    NASA Astrophysics Data System (ADS)

    Böni, P.; Grünauer, F.; Schanzer, C.

    2010-12-01

    With the invention of elliptic guides, the neutron flux at instruments can be increased significantly even without sacrificing resolution. In addition, the phase space homogeneity of the delivered neutrons is improved. Using superpolished metal substrates that are coated with supermirror, it is now possible to install neutron guides close to the moderator thus decreasing the illumination losses of the guide and reducing the background because the entrance window of the elliptic guide can be decreased significantly. We have performed Monte Carlo simulations using the program package MCNP5 to calculate the shielding requirements for an elliptic guide geometry assuming that the initial guide section elements are composed of Al substrates. We show that shielding made from heavy concrete shields the neutron and γ-radiation effectively to levels below 1 μSv/h. It is shown that the elliptic geometry allows to match the phase space of the transported neutrons easily to the needs of the instruments to be installed. In particular it is possible to maintain a compact phase space during the transport of the neutrons because the reflection losses are strongly reduced.

  1. A Primer on Elliptic Functions with Applications in Classical Mechanics

    ERIC Educational Resources Information Center

    Brizard, Alain J.

    2009-01-01

    The Jacobi and Weierstrass elliptic functions used to be part of the standard mathematical arsenal of physics students. They appear as solutions of many important problems in classical mechanics: the motion of a planar pendulum (Jacobi), the motion of a force-free asymmetric top (Jacobi), the motion of a spherical pendulum (Weierstrass) and the…

  2. Exploring Strange Nonchaotic Attractors through Jacobian Elliptic Functions

    ERIC Educational Resources Information Center

    Garcia-Hoz, A. Martinez; Chacon, R.

    2011-01-01

    We demonstrate the effectiveness of Jacobian elliptic functions (JEFs) for inquiring into the reshaping effect of quasiperiodic forces in nonlinear nonautonomous systems exhibiting strange nonchaotic attractors (SNAs). Specifically, we characterize analytically and numerically some reshaping-induced transitions starting from SNAs in the context of…

  3. The use of MACSYMA for solving elliptic boundary value problems

    NASA Technical Reports Server (NTRS)

    Thejll, Peter; Gilbert, Robert P.

    1990-01-01

    A boundary method is presented for the solution of elliptic boundary value problems. An approach based on the use of complete systems of solutions is emphasized. The discussion is limited to the Dirichlet problem, even though the present method can possibly be adapted to treat other boundary value problems.

  4. Buckling characteristic of multi-laminated composite elliptical cylindrical shells

    NASA Astrophysics Data System (ADS)

    Kassegne, Samuel Kinde; Chun, Kyoung-Sik

    2015-03-01

    Fiber-reinforced composite materials continue to experience increased adoption in aerospace, marine, automobile, and civil structures due to their high specific strength, high stiffness, and light weight. This increased use has been accompanied by applications involving non-traditional configurations such as compression members with elliptical cross-sections. To model such shapes, we develop and report an improved generalized shell element called 4EAS-FS through a combination of enhanced assumed strain and the substitute shear strain fields. A flat shell element has been developed by combining a membrane element with drilling degree-of-freedom and a plate bending element. We use the element developed to determine specifically buckling loads and mode shapes of composite laminates with elliptical cross-section including transverse shear deformations. The combined influence of shell geometry and elliptical cross-sectional parameters, fiber angle, and lay-up on the buckling loads of an elliptical cylinder is examined. It is hoped that the critical buckling loads and mode shapes presented here will serve as a benchmark for future investigations.

  5. Instability of low viscosity elliptic jets with varying aspect ratio

    NASA Astrophysics Data System (ADS)

    Kulkarni, Varun

    2011-11-01

    In this work an analytical description of capillary instability of liquid elliptic jets with varying aspect ratio is presented. Linear stability analysis in the long wave approximation with negligible gravitational effects is employed. Elliptic cylindrical coordinate system is used and perturbation velocity potential substituted in the Laplace equation to yield Mathieu and Modified Mathieu differential equations. The dispersion relation for elliptical orifices of any aspect ratio is derived and validated for axisymmetric disturbances with m = 0, in the limit of aspect ratio, μ = 1 , i.e. the case of a circular jet. As Mathieu functions and Modified Mathieu function solutions converge to Bessel's functions in this limit the Rayleigh-Plateau instability criterion is met. Also, stability of solutions corresponding to asymmetric disturbances for the kink mode, m = 1 and flute modes corresponding to m >= 2 is discussed. Experimental data from earlier works is used to compare observations made for elliptical orifices with μ ≠ 1 . This novel approach aims at generalizing the results pertaining to cylindrical jets with circular cross section leading to better understanding of breakup in liquid jets of various geometries.

  6. Elastohydrodynamics of elliptical contacts for materials of low elastic modulus

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.; Dowson, D.

    1983-01-01

    The influence of the ellipticity parameter k and the dimensionless speed U, load W, and materials G parameters on minimum film thickness for materials of low elastic modulus was investigated. The ellipticity parameter was varied from 1 (a ball-on-plane configuration) to 12 (a configuration approaching a line contact); U and W were each varied by one order of magnitude. Seventeen cases were used to generate the minimum- and central-film-thickness relations. The influence of lubricant starvation on minimum film thickness in starved elliptical, elastohydrodynamic configurations was also investigated for materials of low elastic modulus. Lubricant starvation was studied simply by moving the inlet boundary closer to the center of the conjunction in the numerical solutions. Contour plots of pressure and film thickness in and around the contact were presented for both fully flooded and starved lubrication conditions. It is evident from these figures that the inlet pressure contours become less circular and closer to the edge of the Hertzian contact zone and that the film thickness decreases substantially as the serverity of starvation increases. The results presented reveal the essential features of both fully flooded and starved, elliptical, elastohydrodynamic conjunctions for materials of low elastic modulus.

  7. Elliptic cylindrical silicon nanowire hybrid surface plasmon polariton waveguide.

    PubMed

    Zhang, Li; Xiong, Qiulin; Li, Xiaopeng; Ma, Junxian

    2015-08-10

    We researched an elliptic cylindrical silicon nanowire hybrid surface plasmon polariton waveguide and evaluated its mode characteristics using the finite element method software COMSOL. The waveguide consists of three parts: an elliptic cylindrical silicon nanowire, a silver film layer, and a silica covering layer between them. All of the components are surrounded by air. After optimizing the geometrical parameters of the waveguide, we can achieve the waveguide's strong field confinement (ranging from λ2/270 to λ2/27) and long propagation distances (119-485 μm). In order to further understand the impact of the waveguide's architecture on its performance, we also studied the ridge hybrid waveguide. The results show that the ridge waveguide has moderate local field confinement ranging from λ2/190 to λ2/20 and its maximum propagation distance is about 340 μm. We compared the elliptic cylindrical and ridge nanowire hybrid waveguides with the cylindrical hybrid waveguide that we studied before. The elliptic cylindrical waveguide achieves a better trade-off between reasonable mode confinement and maximum propagation length in the three waveguides. The researched hybrid surface plasmon polaritons waveguides are useful to construct devices such as a directional coupler and may find potential applications in photonic integrated circuits or other novel SPP devices. PMID:26368373

  8. Convection in deformed bodies: The effect of equatorial ellipticity on convective behavior

    NASA Astrophysics Data System (ADS)

    Evonuk, M.

    2015-11-01

    Tidal interactions between bodies such as hot jupiter planets and their host stars are likely to result in non-spherical geometries. These elliptical instabilities may have interesting effects on interior fluid convective patterns, which in turn could influence the nature of the magnetic dynamo within these planets. Simulations of thermal convection in the 2D rotating equatorial plane are conducted to determine to first order the effect of equatorial eccentricity on convection for varying density contrasts with differing convective vigor and rotation rates. This survey is conducted in two dimensions in order to simulate a broad range of eccentricities and to maximize the parameter space explored. The location of the three regimes documented in previous work (Evonuk and Samuel, 2012), dipolar flow, transitional flow, and differential flow, are found to be offset by the introduction of equatorial eccentricity to the system. The introduction of equatorial eccentricity changes the fluid behavior such that bodies with high amounts of deformation are likely to have weaker differential flows shifting their behavior towards transitional and dipolar flow structures. A scaling law based on the convective Rossby number, density contrast, and the eccentricity of the equatorial plane can therefore provide a way to estimate which regime a given body lies in.

  9. Line Strength Gradients in Elliptical and Brightest Cluster Galaxies

    NASA Astrophysics Data System (ADS)

    Fisher, David; Franx, Marijn; Illingworth, Garth

    1995-07-01

    Line strengths and their gradients in Mg, Fe, and Hβ have been determined for seven elliptical and nine brightest cluster galaxies (BCGs) in order to study their stellar populations and investigate their relationship to one another. We find that BCGs follow the same relationship between central Mg b line strength and central velocity dispersion found for elliptical galaxies. Brightest cluster galaxies are in agreement with the known trend toward more massive elliptical galaxies having larger [Mg/Fe] ratios, while the internal gradients within our BCG and E galaxies are consistent with a roughly constant [Mg/Fe] ratio. We find that a correlation exists between the central [Mg/Fe] ratio and average Hβ line strength in the sense that both BCG and elliptical galaxies with larger [Mg/Fe] ratios have lower strengths. For our sample, Hβ is the best predictor of [Mg/Fe] ratio. If the dominant contribution to the Hβ feature is from turnoff stars then this relation predicts that more massive elliptical galaxies are older than less massive ones. If, however, the main source of the H index is from horizontal-branch stars, then the observed {[Mg/Fe],HP} relation could be the result of more massive elliptical galaxies having flatter IMFs for high-mass stars than less massive elliptical galaxies. The line strengths of the objects in our sample span a range of values. The BCGs generally have low global Hβ line strengths, which, under the assumption that the Hβ feature can be used as an age discriminant, indicates that the bulk of these systems underwent their last major episode of star formation ≳ 8-10 Gyr ago. For both the elliptical galaxies and BCGs we find that within a galaxy, the Hβ profile is flat for objects whose Hβ absorption can be reliably measured. In the presence of a declining metallicity gradient this suggests that the centers of elliptical galaxies and BCGs are ˜1-3 Gyr younger than their outer regions. The metal line strength gradients for

  10. MIB method for elliptic equations with multi-material interfaces.

    PubMed

    Xia, Kelin; Zhan, Meng; Wei, Guo-Wei

    2011-06-01

    Elliptic partial differential equations (PDEs) are widely used to model real-world problems. Due to the heterogeneous characteristics of many naturally occurring materials and man-made structures, devices, and equipments, one frequently needs to solve elliptic PDEs with discontinuous coefficients and singular sources. The development of high-order elliptic interface schemes has been an active research field for decades. However, challenges remain in the construction of high-order schemes and particularly, for nonsmooth interfaces, i.e., interfaces with geometric singularities. The challenge of geometric singularities is amplified when they are originated from two or more material interfaces joining together or crossing each other. High-order methods for elliptic equations with multi-material interfaces have not been reported in the literature to our knowledge. The present work develops matched interface and boundary (MIB) method based schemes for solving two-dimensional (2D) elliptic PDEs with geometric singularities of multi-material interfaces. A number of new MIB schemes are constructed to account for all possible topological variations due to two-material interfaces. The geometric singularities of three-material interfaces are significantly more difficult to handle. Three new MIB schemes are designed to handle a variety of geometric situations and topological variations, although not all of them. The performance of the proposed new MIB schemes is validated by numerical experiments with a wide range of coefficient contrasts, geometric singularities, and solution types. Extensive numerical studies confirm the designed second order accuracy of the MIB method for multi-material interfaces, including a case where the derivative of the solution diverges. PMID:21691433

  11. From Flat Substrate to Elliptical KB Mirror by Profile Coating

    SciTech Connect

    Liu Chian; Conley, R.; Assoufid, L.; Cai, Z.; Qian, J.; Macrander, A.T.

    2004-05-12

    For microfocusing x-ray mirrors, an elliptical shape is essential for aberration-free optics. However, it is difficult to polish elliptical mirrors to x-ray-quality smoothness. Profile coatings have been applied on both cylindrical and flat Si substrates to make the desired elliptical shape. In a profile-coating process, the sputter source power is kept constant, while the substrate is passed over a contoured mask at a constant speed to obtain a desired profile along the direction perpendicular to the substrate-moving direction. The shape of the contour was derived from a desired profile and the thickness distribution of the coating material at the substrate level. The thickness distribution was measured on films coated on Si wafers using a spectroscopic ellipsometer with computer-controlled X-Y translation stages. The mirror coating profile is determined from the difference between the ideal surface figure of a focusing ellipse and the surface figure obtained from a long trace profiler measurement on the substrate. The number of passes and the moving speed of the substrate are determined according to the required thickness and the growth-rate calibration of a test run. A KB mirror pair was made using Au as a coating material and cylindrically polished mirrors as substrates. Synchrotron x-ray results using this KB mirror pair showed a focused spot size of 0.4 x 0.4 {mu}m2. This technique has also been applied for making elliptical KB mirrors from flat Si substrates. The challenges and solutions associated with elliptical profile coating on flat substrates will be discussed.

  12. Structure and Formation of Elliptical and Spheroidal Galaxies

    NASA Astrophysics Data System (ADS)

    Kormendy, John; Fisher, David B.; Cornell, Mark E.; Bender, Ralf

    2009-05-01

    New surface photometry of all known elliptical galaxies in the Virgo cluster is combined with published data to derive composite profiles of brightness, ellipticity, position angle, isophote shape, and color over large radius ranges. These provide enough leverage to show that Sérsic log I vprop r 1/n functions fit the brightness profiles I(r) of nearly all ellipticals remarkably well over large dynamic ranges. Therefore, we can confidently identify departures from these profiles that are diagnostic of galaxy formation. Two kinds of departures are seen at small radii. All 10 of our ellipticals with total absolute magnitudes MVT <= -21.66 have cuspy cores—"missing light"—at small radii. Cores are well known and naturally scoured by binary black holes (BHs) formed in dissipationless ("dry") mergers. All 17 ellipticals with -21.54 <= MVT <= -15.53 do not have cores. We find a new distinct component in these galaxies: all coreless ellipticals in our sample have extra light at the center above the inward extrapolation of the outer Sérsic profile. In large ellipticals, the excess light is spatially resolved and resembles the central components predicted in numerical simulations of mergers of galaxies that contain gas. In the simulations, the gas dissipates, falls toward the center, undergoes a starburst, and builds a compact stellar component that, as in our observations, is distinct from the Sérsic-function main body of the elliptical. But ellipticals with extra light also contain supermassive BHs. We suggest that the starburst has swamped core scouring by binary BHs. That is, we interpret extra light components as a signature of formation in dissipative ("wet") mergers. Besides extra light, we find three new aspects to the ("E-E") dichotomy into two types of elliptical galaxies. Core galaxies are known to be slowly rotating, to have relatively anisotropic velocity distributions, and to have boxy isophotes. We show that they have Sérsic indices n > 4 uncorrelated

  13. Thermodynamic analysis of spectra

    SciTech Connect

    Mitchell, G. E.; Shriner, J. F. Jr.

    2008-04-04

    Although random matrix theory had its initial application to neutron resonances, there is a relative scarcity of suitable nuclear data. The primary reason for this is the sensitivity of the standard measures used to evaluate spectra--the spectra must be essential pure (no state with a different symmetry) and complete (no states missing). Additional measures that are less sensitive to these experimental limitations are of significant value. The standard measure for long range order is the {delta}{sub 3} statistic. In the original paper that introduced this statistic, Dyson and Mehta also attempted to evaluate spectra with thermodynamic variables obtained from the circular orthogonal ensemble. We consider the thermodynamic 'internal energy' and evaluate its sensitivity to experimental limitations such as missing and spurious levels. Monte Carlo simulations suggest that the internal energy is less sensitive to mistakes than is {delta}{sub 3}, and thus the internal energy can serve as a addition to the tool kit for evaluating experimental spectra.

  14. Wind-tunnel investigation of aerodynamic efficiency of three planar elliptical wings with curvature of quarter-chord line

    NASA Technical Reports Server (NTRS)

    Mineck, Raymond E.; Vijgen, Paul M. H. W.

    1993-01-01

    Three planar, untwisted wings with the same elliptical chord distribution but with different curvatures of the quarter-chord line were tested in the Langley 8-Foot Transonic Pressure Tunnel (8-ft TPT) and the Langley 7- by 10-Foot High-Speed Tunnel (7 x 10 HST). A fourth wing with a rectangular planform and the same projected area and span was also tested. Force and moment measurements from the 8-ft TPT tests are presented for Mach numbers from 0.3 to 0.5 and angles of attack from -4 degrees to 7 degrees. Sketches of the oil-flow patterns on the upper surfaces of the wings and some force and moment measurements from the 7 x 10 HST tests are presented at a Mach number of 0.5. Increasing the curvature of the quarter-chord line makes the angle of zero lift more negative but has little effect on the drag coefficient at zero lift. The changes in lift-curve slope and in the Oswald efficiency factor with the change in curvature of the quarter-chord line (wingtip location) indicate that the elliptical wing with the unswept quarter-chord line has the lowest lifting efficiency and the elliptical wing with the unswept trailing edge has the highest lifting efficiency; the crescent-shaped planform wing has an efficiency in between.

  15. ANISOTROPIC FLOW AT RHIC.

    SciTech Connect

    TANG,A.H.

    2004-03-15

    We present the first measurement of directed flow (v{sub 1}) at the Relativistic Heavy Ion Collider (RHIC). v{sub 1} is found to be consistent with zero at pseudorapidities {eta} from -1.2 to 1.2, then rises to the level of a couple of percent over the range 2.4 < |{eta}| < 4. The latter observation is similar to that from NA49 if the SPS rapidities are shifted by the difference in beam rapidity between RHIC and SPS. We studied the evolution of elliptic flow from p + p collisions through d + Au collision, and onto Au + Au collisions. Measurements of higher harmonics are presented and discussed.

  16. Near-field structure of underexpanded elliptic jets

    NASA Astrophysics Data System (ADS)

    Mitchell, Daniel M.; Honnery, Damon R.; Soria, Julio

    2013-07-01

    Quantitative measurements of velocity for a low aspect ratio underexpanded elliptical jet are presented. Four jets at nozzle pressure ratios NPR = [2.2, 2.6, 3.4, 4.2] are studied for a smoothly contoured elliptical nozzle with an aspect ratio a/ b = 2. High-resolution planar particle image velocimetry is used to extract information about the velocity fields and turbulent statistics. All four jets display the expected axis switching phenomenon, with the axis switching gaining strength with increasing pressure ratio. Evidence of regular reflection is seen for jets at pressure ratios of 2.6 and above. Measurements of fluctuating velocity indicate an oscillatory flapping mode in the minor axis plane for all but the highest pressure ratio. At the highest pressure ratio of NPR = 4.2, there is evidence of a cut-and-connect vortex bifurcation previously only observed for jets with higher aspect ratio.

  17. A New Elliptical Model for Device-Free Localization.

    PubMed

    Lei, Qian; Zhang, Haijian; Sun, Hong; Tang, Linling

    2016-01-01

    Device-free localization (DFL) based on wireless sensor networks (WSNs) is expected to detect and locate a person without the need for any wireless devices. Radio tomographic imaging (RTI) has attracted wide attention from researchers as an emerging important technology in WSNs. However, there is much room for improvement in localization estimation accuracy. In this paper, we propose a geometry-based elliptical model and adopt the orthogonal matching pursuit (OMP) algorithm. The new elliptical model uses not only line-of-sight information, but also non-line-of-sight information, which divides one ellipse into several areas with different weights. Meanwhile the OMP, which can eliminate extra bright spots in image reconstruction, is used to derive an image estimator. The experimental results demonstrate that the proposed algorithm could improve the accuracy of positioning by up to 23.8% for one person and 33.3% for two persons over some state-of-the-art RTI methods. PMID:27110788

  18. Establishing the Metallicity Distribution in Normal Giant Ellipticals

    NASA Astrophysics Data System (ADS)

    Harris, William

    2003-07-01

    NGC 3377 and 3379, the Leo Group ellipticals at d=11 Mpc, are the nearest E galaxies commonly regarded to be structually"normal", and as such, they are keystone objects for understanding the evolution and early star formation history of large ellipticals. The ACS/WFC camera now gives us the ability to obtain the metallicity distribution function {MDF} of their stellar population by direct resolution and photometry of their halo stars. To do this, we will follow the same highly successful techniques we have previously used for NGC 5128 with WFPC2 {V, I} imaging: the {V-I} colors of the brightest red-giant stars are highly sensitive to metallicity, and their locations in the color-magnitude diagram can be used for direct construction of the MDF. This will be a major step forward to understanding the formation history of these cosmologically dominant galaxies.

  19. Parallel computation with adaptive methods for elliptic and hyperbolic systems

    SciTech Connect

    Benantar, M.; Biswas, R.; Flaherty, J.E.; Shephard, M.S.

    1990-01-01

    We consider the solution of two dimensional vector systems of elliptic and hyperbolic partial differential equations on a shared memory parallel computer. For elliptic problems, the spatial domain is discretized using a finite quadtree mesh generation procedure and the differential system is discretized by a finite element-Galerkin technique with a piecewise linear polynomial basis. Resulting linear algebraic systems are solved using the conjugate gradient technique with element-by-element and symmetric successive over-relaxation preconditioners. Stiffness matrix assembly and linear system solutions are processed in parallel with computations scheduled on noncontiguous quadrants of the tree in order to minimize process synchronization. Determining noncontiguous regions by coloring the regular finite quadtree structure is far simpler than coloring elements of the unstructured mesh that the finite quadtree procedure generates. We describe linear-time complexity coloring procedures that use six and eight colors.

  20. Isothermal elastohydrodynamic lubrication of point contacts. II - Ellipticity parameter results

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.; Dowson, D.

    1975-01-01

    A numerical solution of the isothermal elastohydrodynamic problem for point contacts has been presented which reproduces all the essential features of the previously reported experimental observations based upon optical interferometry. In particular, the two 'side lobes' in which minimum film thickness regions occur are shown to emerge in the theoretical solutions. The influence of the ellipticity parameter upon solutions to the point contact problem has been explored in the present paper. The ellipticity parameter (k) was varied from one (a ball on a plate) to eight (a configuration approaching line contact), and it has been shown that both the central and minimum film thicknesses can be related to the well known line contact solutions by remarkably simple expressions involving either (k) or the effective radius of curvature ratio (Ry/Rx).

  1. The Multi-Talented Elliptical Galaxy NGC1052

    NASA Astrophysics Data System (ADS)

    Irwin, Jimmy

    2004-09-01

    We propose to observe the nearby elliptical galaxy NGC1052 for 60 ksec with Chandra to address a variety of issues. First, we will study the interaction between the hot X-ray gas and radio jets/lobes present in this galaxy. A previous short (2 ksec) Chandra observation indicated extended soft emission at the location of the radio emission. Second, NGC1052 is the prototypical LINER galaxy, and this Chandra observation will constrain competing spectral models for the origin of LINER X-ray emission. Finally, we will constrain the X-ray binary--globular cluster connection in elliptical galaxies. NGC1052 contains a large number of globular clusters per unit light, and will be quite useful for determining if all X-ray binaries are formed within globular clusters.

  2. Artist concept of Magellan spacecraft in elliptical orbit around Venus

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Magellan spacecraft is shown in elliptical orbit around Venus, collecting data (radar mapping), and then transmitting data back to Earth in this artist concept. When the spacecraft orbit is close to Venus the synthetic aperature radar (SAR) will image a swath between 9 and 15 nautical miles (10 and 17 statute miles), beginning at or near the north pole and continuing to the southern hemisphere. Subsequent swaths will slightly overlap and, during its primary mission, the spacecraft will map most of the planet. When the spacecraft moves into the part of its elliptical orbit farthest from Venus, the spacecraft high-gain antenna will be turned toward Earth and will send the data collected during the imaging to Earth. Magellan, named after the 16th century Portuguese explorer, will orbit Venus about once every three hours, acquiring radar data for 37 minutes of each orbit. Magellan is managed by the Jet Propulsion Laboratory (JPL); Martin Marietta is developing the spacecraft and Hughes Air

  3. Artist concept of Magellan spacecraft in elliptical orbit around Venus

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Magellan spacecraft is shown in elliptical orbit around Venus, collecting data (radar mapping), and then transmitting data back to Earth in this artist concept. When the spacecraft orbit is close to Venus the synthetic aperature radar (SAR) will image a swath between 9 and 15 nautical miles (10 and 17 statute miles) (highlighted in image), beginning at or near the north pole and continuing to the southern hemisphere. Subsequent swaths will slightly overlap and, during its primary mission, the spacecraft will map most of the planet. When the spacecraft moves into the part of its elliptical orbit farthest from Venus, the spacecraft high-gain antenna will be turned toward Earth and will send the data collected during the imaging to Earth. Magellan, named after the 16th century Portuguese explorer, will orbit Venus about once every three hours, acquiring radar data for 37 minutes of each orbit. Magellan is managed by the Jet Propulsion Laboratory (JPL); Martin Marietta is developing the sp

  4. Is the Capsular Bag Perimeter Round or Elliptical?

    PubMed Central

    Amigó, Alfredo; Bonaque-González, Sergio

    2016-01-01

    Purpose: To report findings that could suggest an elliptical shape of the capsular bag. Methods: Five eyes of three patients with axial length greater than 24 mm underwent phacoemulsification cataract surgery with plate-haptic multifocal toric intraocular lens (IOL) implantation oriented in the vertical meridian. Results: In all cases, correct orientation of the IOLs was verified 30 minutes after surgery. After 24 hours, all eyes demonstrated unwanted rotation of the IOLs ranging from 15 to 45 degrees. The IOLs remained stable in the new position in all cases until adhesion of the capsular bag took place. Conclusion: These observations could suggest that the perimeter of the capsular bag has an elliptical shape. Therefore, the IOL tends to become fixated in a meridian of the capsular bag that best fits the diagonal diameter of the IOL. PMID:27413495

  5. The missing mass in clusters of galaxies and elliptical galaxies

    NASA Technical Reports Server (NTRS)

    Mushotzky, Richard F.

    1991-01-01

    We review the available data for the existence of dark matter in clusters of galaxies and elliptical galaxies. While the amount of dark matter in clusters is not well determined, both the X-ray and optical data show that more than 50 percent of the total mass must be dark. There is in general fair agreement in the binding mass estimates between the X-ray and optical techniques, but there is not detailed agreement on the form of the potential or the distribution of dark matter. The X-ray spectral and spatial observations of elliptical galaxies demonstrate that dark matter is also required in these objects and that it must be considerably more extended than the stellar distribution.

  6. Sole Inversion Precomputation for Elliptic Curve Scalar Multiplications

    NASA Astrophysics Data System (ADS)

    Dahmen, Erik; Okeya, Katsuyuki

    This paper presents a new approach to precompute points [3]P, [5]P, ..., [2k-1]P, for some k ≥ 2 on an elliptic curve over \\mathbb{F}_p. Those points are required for the efficient evaluation of a scalar multiplication, the most important operation in elliptic curve cryptography. The proposed method precomputes the points in affine coordinates and needs only one single field inversion for the computation. The new method is superior to all known methods that also use one field inversion, if the required memory is taken into consideration. Compared to methods that require several field inversions for the precomputation, the proposed method is faster for a broad range of ratios of field inversions and field multiplications. The proposed method benefits especially from ratios as they occur on smart cards.

  7. Decoupling antennas in printed technology using elliptical metasurface cloaks

    NASA Astrophysics Data System (ADS)

    M. Bernety, Hossein; Yakovlev, Alexander B.

    2016-01-01

    In this paper, we extend the idea of reducing the electromagnetic interactions between transmitting radiators to the case of widely used planar antennas in printed technology based on the concept of mantle cloaking. Here, we show that how lightweight elliptical metasurface cloaks can be engineered to restore the intrinsic properties of printed antennas with strip inclusions. In order to present the novel approach, we consider two microstrip-fed monopole antennas resonating at slightly different frequencies cloaked by confocal elliptical metasurfaces formed by arrays of sub-wavelength periodic elements, partially embedded in the substrate. The presence of the metasurfaces leads to the drastic suppression of mutual near-field and far-field couplings between the antennas, and thus, their radiation patterns are restored as if they were isolated. Moreover, it is worth noting that this approach is not limited to printed radiators and can be applied to other planar structures as well.

  8. Wireless OAM transmission system based on elliptical microstrip patch antenna.

    PubMed

    Chen, Jia Jia; Lu, Qian Nan; Dong, Fei Fei; Yang, Jing Jing; Huang, Ming

    2016-05-30

    The multiplexing transmission has always been a focus of attention for communication technology. In this paper, the radiation characteristics of circular microstrip patch antenna was firstly analyzed based on cavity model theory, and then spiral beams carrying orbital angular momentum (OAM) were generated, using elliptical microstrip patch antenna, with a single feed probe instead of a standard circular patch with two feedpoints. Moreover, by combining the proposed elliptic microstrip patch antenna with Universal Software Radio Peripheral (USRP), a wireless OAM transmission system was established and the real-time transmission of text, image and video in a real channel environment was realized. Since the wireless OAM transmission has the advantage of good safety and high spectrum utilization efficiency, this work has theoretical significance and potential application. PMID:27410080

  9. A New Elliptical Model for Device-Free Localization

    PubMed Central

    Lei, Qian; Zhang, Haijian; Sun, Hong; Tang, Linling

    2016-01-01

    Device-free localization (DFL) based on wireless sensor networks (WSNs) is expected to detect and locate a person without the need for any wireless devices. Radio tomographic imaging (RTI) has attracted wide attention from researchers as an emerging important technology in WSNs. However, there is much room for improvement in localization estimation accuracy. In this paper, we propose a geometry-based elliptical model and adopt the orthogonal matching pursuit (OMP) algorithm. The new elliptical model uses not only line-of-sight information, but also non-line-of-sight information, which divides one ellipse into several areas with different weights. Meanwhile the OMP, which can eliminate extra bright spots in image reconstruction, is used to derive an image estimator. The experimental results demonstrate that the proposed algorithm could improve the accuracy of positioning by up to 23.8% for one person and 33.3% for two persons over some state-of-the-art RTI methods. PMID:27110788

  10. Two-center black holes, qubits, and elliptic curves

    NASA Astrophysics Data System (ADS)

    Lévay, Péter

    2011-07-01

    We relate the U-duality invariants characterizing two-center extremal black-hole solutions in the stu, st2, and t3 models of N=2, d=4 supergravity to the basic invariants used to characterize entanglement classes of four-qubit systems. For the elementary example of a D0D4-D2D6 composite in the t3 model we illustrate how these entanglement invariants are related to some of the physical properties of the two-center solution. Next we show that it is possible to associate elliptic curves to charge configurations of two-center composites. The hyperdeterminant of the hypercube, a four-qubit polynomial invariant of order 24 with 2 894 276 terms, is featuring the j invariant of the elliptic curve. We present some evidence that this quantity and its straightforward generalization should play an important role in the physics of two-center solutions.

  11. Elliptical x-ray microprobe mirrors by differential deposition

    SciTech Connect

    Ice, Gene E.; Chung, Jin-Seok; Tischler, Jonathan Z.; Lunt, Andrew; Assoufid, Lahsen

    2000-07-01

    A differential coating method is described for fabricating high-performance x-ray microfocusing mirrors. With this method, the figure of ultrasmooth spherical mirrors can be modified to produce elliptical surfaces with low roughness and low figure errors. Submicron focusing is demonstrated with prototype mirrors. The differential deposition method creates stiff monolithic mirrors which are compact, robust, and easy to cool and align. Prototype mirrors have demonstrated gains of more than 10{sup 4} in beam intensity while maintaining submilliradian divergence on the sample. This method of producing elliptical mirrors is well matched to the requirements of an x-ray microdiffraction Kirkpatrick-Baez focusing system. (c) 2000 American Institute of Physics.

  12. Analysis of multigrid algorithms for nonsymmetric and indefinite elliptic problems

    SciTech Connect

    Bramble, J.H.; Pasciak, J.E.; Xu, J.

    1988-10-01

    We prove some new estimates for the convergence of multigrid algorithms applied to nonsymmetric and indefinite elliptic boundary value problems. We provide results for the so-called 'symmetric' multigrid schemes. We show that for the variable V-script-cycle and the W-script-cycle schemes, multigrid algorithms with any amount of smoothing on the finest grid converge at a rate that is independent of the number of levels or unknowns, provided that the initial grid is sufficiently fine. We show that the V-script-cycle algorithm also converges (under appropriate assumptions on the coarsest grid) but at a rate which may deteriorate as the number of levels increases. This deterioration for the V-script-cycle may occur even in the case of full elliptic regularity. Finally, the results of numerical experiments are given which illustrate the convergence behavior suggested by the theory.

  13. Mott scattering in an elliptically polarized laser field

    SciTech Connect

    Attaourti, Y.; Manaut, B.; Taj, S.

    2004-08-01

    We study Mott scattering in the presence of a strong elliptically polarized field. Using the first Born approximation and the Dirac-Volkov states for the electron, we obtain an analytic formula for the unpolarized differential cross section. This generalizes the results found for the linearly polarized field by Li et al. [ 67, 063409 (2003)] and for the circularly polarized field by Attaourti and Manaut [ 68, 067401 (2003)].

  14. Nonexistence results for elliptic equations with gradient terms

    NASA Astrophysics Data System (ADS)

    Alarcón, S.; Burgos-Pérez, M. Á.; García-Melián, J.; Quaas, A.

    2016-01-01

    We consider the elliptic problem - Δu +| ∇u | q = λf (u) in exterior domains of RN. Here q > 1, f is a nondecreasing, continuous and positive nonlinearity defined in (0, + ∞) and λ > 0 is a parameter. Under suitable assumptions on f near zero or infinity, we obtain some nonexistence results for positive supersolutions, depending on the relative values of q and N/N-1 and on the parameter λ.

  15. Two elliptic closed geodesics on positively curved Finsler spheres

    NASA Astrophysics Data System (ADS)

    Duan, Huagui

    2016-06-01

    In this paper, we prove that for every Finsler n-dimensional sphere (Sn , F) with reversibility λ and flag curvature K satisfying (λ/1+λ) 2 < K ≤ 1, either there exist infinitely many closed geodesics, or there exist at least two elliptic closed geodesics and each linearized Poincaré map has at least one eigenvalue of the form e √{ - 1 } θ with θ being an irrational multiple of π.

  16. The augmented Lagrangian method for parameter estimation in elliptic systems

    NASA Technical Reports Server (NTRS)

    Ito, Kazufumi; Kunisch, Karl

    1990-01-01

    In this paper a new technique for the estimation of parameters in elliptic partial differential equations is developed. It is a hybrid method combining the output-least-squares and the equation error method. The new method is realized by an augmented Lagrangian formulation, and convergence as well as rate of convergence proofs are provided. Technically the critical step is the verification of a coercivity estimate of an appropriately defined Lagrangian functional. To obtain this coercivity estimate a seminorm regularization technique is used.

  17. Towards a theory of automated elliptic mesh generation

    NASA Technical Reports Server (NTRS)

    Cordova, J. Q.

    1992-01-01

    The theory of elliptic mesh generation is reviewed and the fundamental problem of constructing computational space is discussed. It is argued that the construction of computational space is an NP-Complete problem and therefore requires a nonstandard approach for its solution. This leads to the development of graph-theoretic, combinatorial optimization and integer programming algorithms. Methods for the construction of two dimensional computational space are presented.

  18. Fast algorithms for computing isogenies between elliptic curves

    NASA Astrophysics Data System (ADS)

    Bostan, A.; Morain, F.; Salvy, B.; Schost, E.

    2008-09-01

    We survey algorithms for computing isogenies between elliptic curves defined over a field of characteristic either 0 or a large prime. We introduce a new algorithm that computes an isogeny of degree ell ( ell different from the characteristic) in time quasi-linear with respect to ell E This is based in particular on fast algorithms for power series expansion of the Weierstrass wp -function and related functions.

  19. Intrinsic shapes of elliptical galaxy: NGC 1052 using modified prior

    NASA Astrophysics Data System (ADS)

    Kumar Singh, Arun; Chakraborty, D. K.

    Determination of intrinsic shapes of the individual elliptical galaxies using photometry is an important problem because the number of galaxies with good photometry is many more than those with good kinematics. We determine the intrinsic shapes of the light distribution of elliptical galaxies by combining the profiles of photometric data from the literature with triaxial models. We use ensembles of models so that the shape estimates are largely model independent. We follow the methodology as described in Statler (1994) which is modified to suit our requirements. We find that short to long axial ratios at very small radii and at very large radii, and the absolute value of the triaxiality difference are the best constrained shape parameters. Using a flat prior, the shapes of elliptical galaxies are reported by Chakraborty et al (2008) and Singh & Chakraborty (2009). The flat prior of 20 galaxies are superimposed over EAC-Ph other to obtain the distribution. This distribution is regarded as a prior (a modified prior) and shapes of 20 galaxies are again recalculated by using such modified prior. We determine the intrinsic shapes of the elliptical galaxy NGC 1052 using modified prior should be more reliable. These results are compared with the previous estimates which are determined by using flat prior. The plot shows the intrinsic shapes of the NGC 1052 as a function of (q0,q∞) for two dimensional shapes and (q0,q∞, |Td|) for three dimensional shapes, where q0 and q∞(=q) are the short to long axial ratios at small and at large radii and |Td| is the absolute values of the triaxiality difference, defined as |Td|= |T∞ - T0|. The probability is shown in the dark gray region: darker is the region higher is the probability. We find that the galaxy NGC 1052 is flatter inside and flatter outside.

  20. Particle Deposition in Human Lungs due to Varying Cross-Sectional Ellipticity of Left and Right Main Bronchi

    NASA Astrophysics Data System (ADS)

    Roth, Steven; Oakes, Jessica; Shadden, Shawn

    2015-11-01

    Particle deposition in the human lungs can occur with every breathe. Airbourne particles can range from toxic constituents (e.g. tobacco smoke and air pollution) to aerosolized particles designed for drug treatment (e.g. insulin to treat diabetes). The effect of various realistic airway geometries on complex flow structures, and thus particle deposition sites, has yet to be extensively investigated using computational fluid dynamics (CFD). In this work, we created an image-based geometric airway model of the human lung and performed CFD simulations by employing multi-domain methods. Following the flow simulations, Lagrangian particle tracking was used to study the effect of cross-sectional shape on deposition sites in the conducting airways. From a single human lung model, the cross-sectional ellipticity (the ratio of major and minor diameters) of the left and right main bronchi was varied systematically from 2:1 to 1:1. The influence of the airway ellipticity on the surrounding flow field and particle deposition was determined.

  1. Instability of a supersonic shock free elliptic jet

    NASA Technical Reports Server (NTRS)

    Baty, Roy S.; Seiner, John M.; Ponton, Michael K.

    1990-01-01

    This paper presents a comparison of the measured and the computed spatial stability properties of an aspect ratio 2 supersonic shock free elliptic jet. The shock free nature of the elliptic jet provides an ideal test of validity of modeling the large scale coherent structures in the initial mixing region of noncircular supersonic jets with linear hydrodynamic stability theory. Both aerodynamic and acoustic data were measured. The data are used to compute the mean velocity profiles and to provide a description of the spatial composition of pressure waves in the elliptic jet. A hybrid numerical scheme is applied to solve the Rayleigh problem governing the inviscid linear spatial stability of the jet. The measured mean velocity profiles are used to provide a qualitative model for the cross sectional geometry and the smooth velocity profiles used in the stability analysis. Computational results are presented for several modes of instability at two jet cross sections. The acoustic measurements show that a varicose instability is the jet's perferred mode of motion. The stability analysis predicts that the Strouhal number varies linearly as a function of axial distance in the jet's initial mixing region, which is in good qualitative agreement with previous measurements.

  2. Anisotropic elliptic optical fibers. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Kang, Soon Ahm

    1991-01-01

    The exact characteristic equation for an anisotropic elliptic optical fiber is obtained for odd and even hybrid modes in terms of infinite determinants utilizing Mathieu and modified Mathieu functions. A simplified characteristic equation is obtained by applying the weakly guiding approximation such that the difference in the refractive indices of the core and the cladding is small. The simplified characteristic equation is used to compute the normalized guide wavelength for an elliptical fiber. When the anisotropic parameter is equal to unity, the results are compared with the previous research and they are in close agreement. For a fixed value normalized cross-section area or major axis, the normalized guide wavelength lambda/lambda(sub 0) for an anisotropic elliptic fiber is small for the larger value of anisotropy. This condition indicates that more energy is carried inside of the fiber. However, the geometry and anisotropy of the fiber have a smaller effect when the normalized cross-section area is very small or very large.

  3. Major and minor axis kinematics of 22 ellipticals

    NASA Astrophysics Data System (ADS)

    Franx, Marijn; Illingworth, Garth; Heckman, Timothy

    1989-09-01

    Rotation curves and velocity dispersion profiles have been determined for the major and the minor axes of 22 elliptical galaxies. Rotation was detected in all but one galaxy, even though the sample was biased toward round ellipticals. Minor axis rotation larger than major axis rotation was measured in two galaxies, NGC 4406 and NGC 7507. Roughly 10 percent of ellipticals may show large minor axis velocities relative to those on the major axis. A simple model is used to derive a rotational axis from the observed minor and major axis velocities to a typical accuracy of 6 deg. The rotational and photometric minor axes aligned to better than 10 deg for 60 percent of the sample, implying that the direction of the angular momentum is related to the orientation of the figure of the galaxy. IC 1459 has a kinematically distinct core with its angular momentum opposite to the angular momentum of the outer parts, and NGC 4406 has a core with its angular momentum perpendicular to that of the outer parts.

  4. Instability of a supersonic shock free elliptic jet

    SciTech Connect

    Baty, R.S. ); Seiner, J.M.; Ponton, M.K. . Langley Research Center)

    1990-01-01

    This paper presents a comparison of the measured and the computed spatial stability properties of an aspect ratio 2 supersonic shock free elliptic jet. The shock free nature of the elliptic jet provides an ideal test of validity of modeling the large scale coherent structures in the initial mixing region of noncircular supersonic jets with linear hydrodynamic stability theory. Both aerodynamic and acoustic data were measured. The data are used to compute the mean velocity profiles and to provide a description of the spatial composition of pressure waves in the elliptic jet. A hybrid numerical scheme is applied to solve the Rayleigh problem governing the inviscid linear spatial stability of the jet. The measured mean velocity profiles are used to provide a qualitative model for the cross sectional geometry and the smooth velocity profiles used in the stability analysis. Computational results are presented for several modes of instability at two jet cross sections. The acoustic measurements show that a varicose instability is the jet's perferred mode of motion. The stability analysis predicts that the Strouhal number varies linearly as a function of axial distance in the jet's initial mixing region, which is in good qualitative agreement with previous measurements. 18 refs., 18 figs., 1 tab.

  5. On the distribution of scalar k for elliptic scalar multiplication

    NASA Astrophysics Data System (ADS)

    Ajeena, Ruma Kareem K.; Kamarulhaili, Hailiza

    2015-10-01

    In this study, we introduce the probability distribution of the elliptic curve scalar multiplication through finding the probability distribution of the secret key, namely, the scalar k of the scalar multiplication kP of a point P which has a large prime order n lying on elliptic curve group E(Fp) over a finite prime field Fp. To determine this distribution of k, we use the integer sub-decomposition (ISD) approach that inspired from Gallant, Lambert and Vanstone (GLV) idea. In ISD approach, the distribution of the values of scalars k lie outside the range ±√{n } on the interval [1, n - 1]. This distribution determines the successful rate to compute a scalar multiplication kP, on ISD approach, in comparison with the original GLV method. The conception of the ISD approach depends on the sub- decomposition of the scalar k to compute the scalar multiplication kP which uses efficiently computable endomorphisms Ψ1 and Ψ2 of elliptic curve E over Fp. The ISD sub-decomposition can be defined by k P =k11P +k12ψ1(P )+k21P +k22ψ2(P ), with max{ | k11 | ,| k12 | } and max{ | k21 | ,| k22 | } ≤C √{n }, for some explicit constant C > 0. Furthermore, this study compares between the GLV and ISD approaches on the basis of the probability distribution of the scalar k in the interval [1, n - 1], where n is a large prime number.

  6. Shape measurement biases from underfitting and ellipticity gradients

    SciTech Connect

    Bernstein, Gary M.

    2010-08-21

    With this study, precision weak gravitational lensing experiments require measurements of galaxy shapes accurate to <1 part in 1000. We investigate measurement biases, noted by Voigt and Bridle (2009) and Melchior et al. (2009), that are common to shape measurement methodologies that rely upon fitting elliptical-isophote galaxy models to observed data. The first bias arises when the true galaxy shapes do not match the models being fit. We show that this "underfitting bias" is due, at root, to these methods' attempts to use information at high spatial frequencies that has been destroyed by the convolution with the point-spread function (PSF) and/or by sampling. We propose a new shape-measurement technique that is explicitly confined to observable regions of k-space. A second bias arises for galaxies whose ellipticity varies with radius. For most shape-measurement methods, such galaxies are subject to "ellipticity gradient bias". We show how to reduce such biases by factors of 20–100 within the new shape-measurement method. The resulting shear estimator has multiplicative errors < 1 part in 103 for high-S/N images, even for highly asymmetric galaxies. Without any training or recalibration, the new method obtains Q = 3000 in the GREAT08 Challenge of blind shear reconstruction on low-noise galaxies, several times better than any previous method.

  7. Shape measurement biases from underfitting and ellipticity gradients

    DOE PAGESBeta

    Bernstein, Gary M.

    2010-08-21

    With this study, precision weak gravitational lensing experiments require measurements of galaxy shapes accurate to <1 part in 1000. We investigate measurement biases, noted by Voigt and Bridle (2009) and Melchior et al. (2009), that are common to shape measurement methodologies that rely upon fitting elliptical-isophote galaxy models to observed data. The first bias arises when the true galaxy shapes do not match the models being fit. We show that this "underfitting bias" is due, at root, to these methods' attempts to use information at high spatial frequencies that has been destroyed by the convolution with the point-spread function (PSF)more » and/or by sampling. We propose a new shape-measurement technique that is explicitly confined to observable regions of k-space. A second bias arises for galaxies whose ellipticity varies with radius. For most shape-measurement methods, such galaxies are subject to "ellipticity gradient bias". We show how to reduce such biases by factors of 20–100 within the new shape-measurement method. The resulting shear estimator has multiplicative errors < 1 part in 103 for high-S/N images, even for highly asymmetric galaxies. Without any training or recalibration, the new method obtains Q = 3000 in the GREAT08 Challenge of blind shear reconstruction on low-noise galaxies, several times better than any previous method.« less

  8. Determining spatial orientation of axes of elliptical magnetic field

    NASA Astrophysics Data System (ADS)

    Rudnitskiy, L. M.; Frumin, V. L.; Guyetskiy, B. A.; Klimov, N. Z.

    1984-11-01

    The rotating magnetic field in induction motors is often elliptical, because of asymmetry of the polyphase line voltages or structural asymmetry in the machine. For an accurate analysis of electromechanical energy conversion in such a machine, one must then take into account the ellipticity of the magnetic field with the attendant nonuniformity of saturation. A generalized two field model of an induction motor is proposed for this purpose, with superposition of two mutually orthogonal elliptical pulsating fields in stator coordinates. The self inductances and the mutual inductances can be subsequently calculated on this basis. The spatial orientation of the two ellipses, specifically of their axes, needs to be determined first and this is done here for the most general case of an asymmetric machine with m stator phases and n rotor phases under asymmetric input voltages. The magnetizing force of any stator phase and any rotor phase is calculated accordingly, then the resultant magnetizing force and its space distribution. The major axis and the minor axis of the resultant ellipse correspond to the direction of the respectively maximum and minimum magnetizing force. Numerical results converging after six iterations are shown for a machine with m 3 stator phases and n = 2 rotor phases.

  9. Properties of Ellipticity Correlation with Atmospheric Structure From Gemini South

    SciTech Connect

    Asztalos, Stephen J.; de Vries, W.H.; Rosenberg, L.J; Treadway, T.; Burke, D.; Claver, C.; Saha, A.; Puxley, P.; /Gemini Observ., La Serena

    2007-01-17

    Cosmic shear holds great promise for a precision independent measurement of {Omega}{sub m}, the mass density of the universe relative to the critical density. The signal is expected to be weak, so a thorough understanding of systematic effects is crucial. An important systematic effect is the atmosphere: shear power introduced by the atmosphere is larger than the expected signal. Algorithms exist to extract the cosmic shear from the atmospheric component, though a measure of their success applied to a range of seeing conditions is lacking. To gain insight into atmospheric shear, Gemini South imaging in conjunction with ground condition and satellite wind data were obtained. We find that under good seeing conditions Point-Spread-Function (PSF) correlations persist well beyond the separation typical of high-latitude stars. Under these conditions, ellipticity residuals based on a simple PSF interpolation can be reduced to within a factor of a few of the shot-noise induced ellipticity floor. We also find that the ellipticity residuals are highly correlated with wind direction. Finally, we correct stellar shapes using a more sophisticated procedure and generate shear statistics from stars. Under all seeing conditions in our data set the residual correlations lie everywhere below the target signal level. For good seeing we find that the systematic error attributable to atmospheric turbulence is comparable in magnitude to the statistical error (shape noise) over angular scales relevant to present lensing surveys.

  10. Properties of Ellipticity Correlation with Atmospheric Structure from Gemini South

    SciTech Connect

    Asztalos, S J; Treadway, T; de Vries, W H; Rosenberg, L J; Burke, D; Claver, C; Saha, A; Puxley, P

    2006-12-21

    Cosmic shear holds great promise for a precision independent measurement of {Omega}{sub m}, the mass density of the universe relative to the critical density. The signal is expected to be weak, so a thorough understanding of systematic effects is crucial. An important systematic effect is the atmosphere: shear power introduced by the atmosphere is larger than the expected signal. Algorithms exist to extract the cosmic shear from the atmospheric component, though a measure of their success applied to a range of seeing conditions is lacking. To gain insight into atmospheric shear, Gemini South imaging in conjunction with ground condition and satellite wind data were obtained. We find that under good seeing conditions Point-Spread-Function (PSF) correlations persist well beyond the separation typical of high-latitude stars. Under these conditions, ellipticity residuals based on a simple PSF interpolation can be reduced to within a factor of a few of the shot-noise induced ellipticity floor. We also find that the ellipticity residuals are highly correlated with wind direction. Finally, we correct stellar shapes using a more sophisticated procedure and generate shear statistics from stars. Under all seeing conditions in our data set the residual correlations lie everywhere below the target signal level. For good seeing we find that the systematic error attributable to atmospheric turbulence is comparable in magnitude to the statistical error (shape noise) over angular scales relevant to present lensing surveys.

  11. Intrinsic momentum transport in tokamaks with tilted elliptical flux surfaces

    NASA Astrophysics Data System (ADS)

    Ball, Justin; Parra, Felix; Barnes, Michael; Dorland, William; Hammett, Gregory; Rodrigues, Paulo; Loureiro, Nuno

    2014-10-01

    Recent work demonstrated that breaking the up-down symmetry of tokamaks removes a constraint limiting intrinsic momentum transport, and hence toroidal rotation, to be small. We show, through MHD analysis, that ellipticity is most effective at introducing up-down asymmetry throughout the plasma. Using GS2, a local δf gyrokinetic code that self-consistently calculates momentum transport, we simulate tokamaks with tilted elliptical poloidal cross-sections and a Shafranov shift. These simulations show both the magnitude and poloidal dependence of nonlinear momentum transport. The results are consistent with TCV experimental measurements and suggest that this mechanism can generate rotation with an Alfven Mach number of several percent in a tilted elliptical ITER-like machine. It appears that rotation generated with up-down asymmetry may be sufficient to stabilize the resistive wall mode in reactor-sized devices. J.R.B. and F.I.P. were partially supported by the RCUK Energy Programme (grant number EP/I501045) and the European Unions Horizon 2020 research and innovation programme.

  12. Elliptic surface grid generation on minimal and parmetrized surfaces

    NASA Technical Reports Server (NTRS)

    Spekreijse, S. P.; Nijhuis, G. H.; Boerstoel, J. W.

    1995-01-01

    An elliptic grid generation method is presented which generates excellent boundary conforming grids in domains in 2D physical space. The method is based on the composition of an algebraic and elliptic transformation. The composite mapping obeys the familiar Poisson grid generation system with control functions specified by the algebraic transformation. New expressions are given for the control functions. Grid orthogonality at the boundary is achieved by modification of the algebraic transformation. It is shown that grid generation on a minimal surface in 3D physical space is in fact equivalent to grid generation in a domain in 2D physical space. A second elliptic grid generation method is presented which generates excellent boundary conforming grids on smooth surfaces. It is assumed that the surfaces are parametrized and that the grid only depends on the shape of the surface and is independent of the parametrization. Concerning surface modeling, it is shown that bicubic Hermite interpolation is an excellent method to generate a smooth surface which is passing through a given discrete set of control points. In contrast to bicubic spline interpolation, there is extra freedom to model the tangent and twist vectors such that spurious oscillations are prevented.

  13. Theoretical results for fully flooded, elliptical hydrodynamic contacts

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.; Dowson, D.

    1982-01-01

    The influence of the ellipticity parameter and the dimensionless speed, load, and materials parameters on minimum film thickness was investigated. The ellipticity parameter was varied from 1 (a ball-on-plate configuration) to 8 (a configuration approaching a line contact). The dimensionless speed parameter was varied over a range of nearly two orders of magnitude. Conditions corresponding to the use of solid materials of bronze, steel, and silicon nitride and lubricants of praffinic and naphthemic mineral oils were considered in obtaining the exponent in the dimensionless materials parameter. Thirty-four different cases were used in obtaining the minimum film thickness formula H min = 3.63U to the 0.68 power G to the 0.49 power W to the -0.073 power 1-e to the 0.68K power). A simplified expression for the ellipticity parameter was found where k = 1.03 (r(y)/r(x)) to the 0.64 power. Contour plots were also shown which indicate in detail the pressure spike and two side lobes in which the minimum film thickness occurs. These theoretical solutions of film thickness have all the essential features of the previously reported experimental observations based upon optical interferometry.

  14. Tunnel Point Cloud Filtering Method Based on Elliptic Cylindrical Model

    NASA Astrophysics Data System (ADS)

    Zhua, Ningning; Jiaa, Yonghong; Luo, Lun

    2016-06-01

    The large number of bolts and screws that attached to the subway shield ring plates, along with the great amount of accessories of metal stents and electrical equipments mounted on the tunnel walls, make the laser point cloud data include lots of non-tunnel section points (hereinafter referred to as non-points), therefore affecting the accuracy for modeling and deformation monitoring. This paper proposed a filtering method for the point cloud based on the elliptic cylindrical model. The original laser point cloud data was firstly projected onto a horizontal plane, and a searching algorithm was given to extract the edging points of both sides, which were used further to fit the tunnel central axis. Along the axis the point cloud was segmented regionally, and then fitted as smooth elliptic cylindrical surface by means of iteration. This processing enabled the automatic filtering of those inner wall non-points. Experiments of two groups showed coincident results, that the elliptic cylindrical model based method could effectively filter out the non-points, and meet the accuracy requirements for subway deformation monitoring. The method provides a new mode for the periodic monitoring of tunnel sections all-around deformation in subways routine operation and maintenance.

  15. Elliptically polarized terahertz radiation from a chiral oxide

    SciTech Connect

    Takeda, R.; Kida, N. Sotome, M.; Okamoto, H.

    2015-09-28

    Polarization control of terahertz wave is a challenging subject in terahertz science and technology. Here, we report a simple method to control polarization state of the terahertz wave in terahertz generation process. At room temperature, terahertz radiation from a noncentrosymmetric and chiral oxide, sillenite Bi{sub 12}GeO{sub 20}, is observed by the irradiation of linearly polarized femtosecond laser pulses at 800 nm. The polarization state of the emitted terahertz wave is found to be elliptic with an ellipticity of ∼0.37 ± 0.10. Furthermore, the ellipticity was altered to a nearly zero (∼0.01 ± 0.01) by changing the polarization of the incident linearly polarized femtosecond laser pulses. Such a terahertz radiation characteristic is attributable to variation of the polarization state of the emitted terahertz waves, which is induced by retardation due to the velocity mismatch between the incident femtosecond laser pulse and generated terahertz wave and by the polarization tilting due to the optical activity at 800 nm.

  16. Eccentricity Fluctuations Make Flow Measurable in High Multiplicity p-p Collisions

    SciTech Connect

    Casalderrey-Solana, Jorge; Wiedemann, Urs Achim

    2010-03-12

    Elliptic flow is a hallmark of collectivity in hadronic collisions. Its measurement relies on analysis techniques which require high event multiplicity and so far can only be applied to heavy ion collisions. Here, we delineate the conditions under which elliptic flow becomes measurable in the samples of high-multiplicity (dN{sub ch}/dy>=50) p-p collisions, which will soon be collected at the LHC. We observe that fluctuations in the p-p interaction region can result in a sizable spatial eccentricity even for the most central p-p collisions. Under relatively mild assumptions on the nature of such fluctuations and on the eccentricity scaling of elliptic flow, we find that the resulting elliptic flow signal in high-multiplicity p-p collisions at the LHC becomes measurable with standard techniques.

  17. Atomic Spectra Database (ASD)

    National Institute of Standards and Technology Data Gateway

    SRD 78 NIST Atomic Spectra Database (ASD) (Web, free access)   This database provides access and search capability for NIST critically evaluated data on atomic energy levels, wavelengths, and transition probabilities that are reasonably up-to-date. The NIST Atomic Spectroscopy Data Center has carried out these critical compilations.

  18. BINARY COMPACT OBJECT COALESCENCE RATES: THE ROLE OF ELLIPTICAL GALAXIES

    SciTech Connect

    O'Shaughnessy, R.; Kalogera, V.; Belczynski, Krzysztof E-mail: vicky@northwestern.ed

    2010-06-10

    In this paper, we estimate binary compact object merger detection rates for LIGO, including the potentially significant contribution from binaries that are produced in elliptical galaxies near the epoch of peak star formation. Specifically, we convolve hundreds of model realizations of elliptical- and spiral-galaxy population syntheses with a model for elliptical- and spiral-galaxy star formation history as a function of redshift. Our results favor local merger rate densities of 4 x 10{sup -3} Mpc{sup -3} Myr{sup -1} for binary black holes (BHs), 3 x 10{sup -2} Mpc{sup -3} Myr{sup -1} for binary neutron stars (NSs), and 10{sup -2} Mpc{sup -3} Myr{sup -1} for BH-NS binaries. We find that mergers in elliptical galaxies are a significant fraction of our total estimate for BH-BH and BH-NS detection rates; NS-NS detection rates are likely dominated by the contribution from spiral galaxies. Limiting attention to elliptical-galaxy plus only those spiral-galaxy models that reproduce current observations of Galactic NS-NS, we find slightly higher rates for NS-NS and largely similar ranges for BH-NS and BH-BH binaries. Assuming a detection signal-to-noise ratio threshold of 8 for a single detector (in practice as part of a network, to reduce its noise), corresponding to radii D {sub bns} of the effective volume inside of which a single LIGO detector could observe the inspiral of two 1.4 M {sub sun} NSs of 14 Mpc and 197 Mpc, for initial and advanced LIGO, we find event rates of any merger type of 2.9 x 10{sup -2}-0.46 and 25-400 yr{sup -1} (at 90% confidence level), respectively. We also find that the probability P {sub detect} of detecting one or more mergers with this single detector can be approximated by (1) P {sub detect} {approx_equal} 0.4 + 0.5 log(T/0.01 yr), assuming D {sub bns} = 197 Mpc and it operates for T yr, for T between 2 days and 0.1 yr, or by (2) P {sub detect} {approx_equal} 0.5 + 1.5 log(D {sub bns}/32 Mpc), for 1 yr of operation and for D {sub bns

  19. Arcjet Semi-Elliptic Nozzle Simulations and Validation in Support of TPS Testing

    NASA Technical Reports Server (NTRS)

    Loomis, Mark; Polsky, Susan; Venkatapaty, Ethiraj; Bailboni, John; Terrazas-Salinas, Imelda

    1998-01-01

    Much of the ground based testing of advanced thermal protection system (TPS) components for the X33 program is done in arc-heated wind tunnels such as those located in the Arc-Jet Complex at NASA Ames Research Center. These facilities are capable of simulating the high temperature, chemically reacting flow environment experienced by the vehicle during flight. This allows one to test critical design issues such as maximum reuse temperatures, seals, gaps, and increases in heating due to interfaces between different materials. Computational fluid dynamics (CFD) has evolved to the point where it now can be used in the vehicle design process for accurate and timely prediction of trajectory based aerothermal heating environments for re-entry vehicles. It can also be used for simulation of the flow environments in ground based facilities such as arcjets. By utilization of the same CFD code and solution methodology, the important differences between ground test and flight may be quantified. The goal of this paper is to utilize CFD to provide validated simulations of the flow environment in the NASA-Ames semi elliptic nozzle arcjet facilities. The validation of the ground simulations will come From comparison to existing calibration data. Specific tests in support of the X33 TPS test program will ilso be simulated. In this manner, the differences between the ground test simulation and the flight environment can be identified for a measure of ground test to flight traceability.

  20. Increased heat transfer to elliptical leading edges due to spanwise variations in the freestream momentum: Numerical and experimental results

    NASA Technical Reports Server (NTRS)

    Rigby, D. L.; Vanfossen, G. J.

    1992-01-01

    A study of the effect of spanwise variation in momentum on leading edge heat transfer is discussed. Numerical and experimental results are presented for both a circular leading edge and a 3:1 elliptical leading edge. Reynolds numbers in the range of 10,000 to 240,000 based on leading edge diameter are investigated. The surface of the body is held at a constant uniform temperature. Numerical and experimental results with and without spanwise variations are presented. Direct comparison of the two-dimensional results, that is, with no spanwise variations, to the analytical results of Frossling is very good. The numerical calculation, which uses the PARC3D code, solves the three-dimensional Navier-Stokes equations, assuming steady laminar flow on the leading edge region. Experimentally, increases in the spanwise-averaged heat transfer coefficient as high as 50 percent above the two-dimensional value were observed. Numerically, the heat transfer coefficient was seen to increase by as much as 25 percent. In general, under the same flow conditions, the circular leading edge produced a higher heat transfer rate than the elliptical leading edge. As a percentage of the respective two-dimensional values, the circular and elliptical leading edges showed similar sensitivity to span wise variations in momentum. By equating the root mean square of the amplitude of the spanwise variation in momentum to the turbulence intensity, a qualitative comparison between the present work and turbulent results was possible. It is shown that increases in leading edge heat transfer due to spanwise variations in freestream momentum are comparable to those due to freestream turbulence.

  1. Anisotropic flow at the SPS and RHIC

    SciTech Connect

    Poskanzer, Arthur M.

    2001-10-19

    The results on directed and elliptic flow for Pb + Pb at the full energy of the SPS (158 GeV/A) and from the first year of Au + Au at RHIC ({radical}s{sub NN} = 130 GeV) are reviewed. The different experiments agree well and a consistent picture has emerged indicating early time thermalization at RHIC.

  2. Rotation and conversion of transmission mode based on a rotatable elliptical core ring resonator

    NASA Astrophysics Data System (ADS)

    Liu, Bin; Liu, Yun-Feng; Li, Shu-Jing; He, Xing-Dao

    2016-06-01

    A compact plasmonic waveguide system consisting of a rotating elliptical core ring (ECR) coupled two metal-insulator-metal (MIM) waveguides is proposed. Influences of the eccentricity and rotation angle of the elliptical core on the transmission characteristics are studied in detail, by using Finite-Difference Time-Domain (FDTD) method. Compared with circular core in ring resonator, the elliptical core will lead to the asymmetric field distributions of intrinsic mode. Based on this, a 1×2 splitter is designed, in which the beam-splitting ratio can be adjusted by changing the eccentricity of the elliptical core. In addition, we find that the intrinsic mode of ECR rotate with elliptical core and gradually convert to its orthogonal mode. Separation of the pair orthogonal modes increases with growth of the eccentricity of the elliptical core. And, the higher order intrinsic mode corresponds to the shorter rotation angle of mode conversion.

  3. Stars and their Spectra

    NASA Astrophysics Data System (ADS)

    Kaler, James B.

    1997-03-01

    This unique and informative text describes how stars are classified according to their spectral qualities and temperature. James Kaler explains the alphabet of stellar astronomy, running from cool M stars to hot O stars, and tells the story of their evolution. Before embarking on a voyage of cosmic discovery, the author discusses the fundamental properties of stars, their atomic structure and the formation of spectra. Then, Kaler considers each star type individually and explores its spectra in detail. A review of unusual, hard-to-classify stars, and a discussion of data related to the birth, life and death of stars round out the text. This book is an important resource for all amateur astronomers and students of astronomy. Professionals will find it a refreshing read as well.

  4. Parmeterization of spectra

    NASA Technical Reports Server (NTRS)

    Cornish, C. R.

    1983-01-01

    Following reception and analog to digital conversion (A/D) conversion, atmospheric radar backscatter echoes need to be processed so as to obtain desired information about atmospheric processes and to eliminate or minimize contaminating contributions from other sources. Various signal processing techniques have been implemented at mesosphere-stratosphere-troposphere (MST) radar facilities to estimate parameters of interest from received spectra. Such estimation techniques need to be both accurate and sufficiently efficient to be within the capabilities of the particular data-processing system. The various techniques used to parameterize the spectra of received signals are reviewed herein. Noise estimation, electromagnetic interference, data smoothing, correlation, and the Doppler effect are among the specific points addressed.

  5. Barnacle Bill Spectra

    NASA Technical Reports Server (NTRS)

    1997-01-01

    These IMP spectra show the characteristics of the rock surface measured by the Alpha Proton X-Ray Spectrometer (blue), the soil trapped in pits on the rock surface (red), and the deposit of bright drift on the top of the rock. The area measured by the APXS has the properties expected for nearly unweathered igneous rock, and the soil trapped in the pits is intermediate to the unweathered rock and the highly weathered drift material.

  6. Multispectral processing without spectra

    NASA Astrophysics Data System (ADS)

    Drew, Mark S.; Finlayson, Graham D.

    2003-07-01

    It is often the case that multiplications of whole spectra, component by component, must be carried out, for example when light reflects from or is transmitted through materials. This leads to particularly taxing calculations, especially in spectrally based ray tracing or radiosity in graphics, making a full-spectrum method prohibitively expensive. Nevertheless, using full spectra is attractive because of the many important phenomena that can be modeled only by using all the physics at hand. We apply to the task of spectral multiplication a method previously used in modeling RGB-based light propagation. We show that we can often multiply spectra without carrying out spectral multiplication. In previous work J. Opt. Soc. Am. A 11 , 1553 (1994) we developed a method called spectral sharpening, which took camera RGBs to a special sharp basis that was designed to render illuminant change simple to model. Specifically, in the new basis, one can effectively model illuminant change by using a diagonal matrix rather than the 33 linear transform that results from a three-component finite-dimensional model G. Healey and D. Slater, J. Opt. Soc. Am. A 11 , 3003 (1994). We apply this idea of sharpening to the set of principal components vectors derived from a representative set of spectra that might reasonably be encountered in a given application. With respect to the sharp spectral basis, we show that spectral multiplications can be modeled as the multiplication of the basis coefficients. These new product coefficients applied to the sharp basis serve to accurately reconstruct the spectral product. Although the method is quite general, we show how to use spectral modeling by taking advantage of metameric surfaces, ones that match under one light but not another, for tasks such as volume rendering. The use of metamers allows a user to pick out or merge different volume structures in real time simply by changing the lighting. 2003 Optical Society of America

  7. Multispectral processing without spectra.

    PubMed

    Drew, Mark S; Finlayson, Graham D

    2003-07-01

    It is often the case that multiplications of whole spectra, component by component, must be carried out,for example when light reflects from or is transmitted through materials. This leads to particularly taxing calculations, especially in spectrally based ray tracing or radiosity in graphics, making a full-spectrum method prohibitively expensive. Nevertheless, using full spectra is attractive because of the many important phenomena that can be modeled only by using all the physics at hand. We apply to the task of spectral multiplication a method previously used in modeling RGB-based light propagation. We show that we can often multiply spectra without carrying out spectral multiplication. In previous work [J. Opt. Soc. Am. A 11, 1553 (1994)] we developed a method called spectral sharpening, which took camera RGBs to a special sharp basis that was designed to render illuminant change simple to model. Specifically, in the new basis, one can effectively model illuminant change by using a diagonal matrix rather than the 3 x 3 linear transform that results from a three-component finite-dimensional model [G. Healey and D. Slater, J. Opt. Soc. Am. A 11, 3003 (1994)]. We apply this idea of sharpening to the set of principal components vectors derived from a representative set of spectra that might reasonably be encountered in a given application. With respect to the sharp spectral basis, we show that spectral multiplications can be modeled as the multiplication of the basis coefficients. These new product coefficients applied to the sharp basis serve to accurately reconstruct the spectral product. Although the method is quite general, we show how to use spectral modeling by taking advantage of metameric surfaces, ones that match under one light but not another, for tasks such as volume rendering. The use of metamers allows a user to pick out or merge different volume structures in real time simply by changing the lighting. PMID:12868625

  8. Spectra of electron oscillations in magnetoplasmadynamic thruster

    NASA Astrophysics Data System (ADS)

    Kirdyashev, K. P.; Kubarev, Yu. V.

    2012-03-01

    The intensity and spectra of electron oscillations in magnetoplasmadynamic (MPD) thruster have been experimentally studied. Oscillatory regimes corresponding to various relations between the relative gradients of magnetic field, electron concentration, and residual gas pressure in the vacuum chamber of the experimental setup have been determined. Relationship between the regimes of excitation of electron oscillations, the formation of an azimuthal current, and a change in the plasma flow potential is revealed. Model notions about the instability of plasma flow on low- and high-frequency branches of electron oscillations are developed.

  9. Flows of X-ray gas reveal the disruption of a star by a massive black hole.

    PubMed

    Miller, Jon M; Kaastra, Jelle S; Miller, M Coleman; Reynolds, Mark T; Brown, Gregory; Cenko, S Bradley; Drake, Jeremy J; Gezari, Suvi; Guillochon, James; Gultekin, Kayhan; Irwin, Jimmy; Levan, Andrew; Maitra, Dipankar; Maksym, W Peter; Mushotzky, Richard; O'Brien, Paul; Paerels, Frits; de Plaa, Jelle; Ramirez-Ruiz, Enrico; Strohmayer, Tod; Tanvir, Nial

    2015-10-22

    Tidal forces close to massive black holes can violently disrupt stars that make a close approach. These extreme events are discovered via bright X-ray and optical/ultraviolet flares in galactic centres. Prior studies based on modelling decaying flux trends have been able to estimate broad properties, such as the mass accretion rate. Here we report the detection of flows of hot, ionized gas in high-resolution X-ray spectra of a nearby tidal disruption event, ASASSN-14li in the galaxy PGC 043234. Variability within the absorption-dominated spectra indicates that the gas is relatively close to the black hole. Narrow linewidths indicate that the gas does not stretch over a large range of radii, giving a low volume filling factor. Modest outflow speeds of a few hundred kilometres per second are observed; these are below the escape speed from the radius set by variability. The gas flow is consistent with a rotating wind from the inner, super-Eddington region of a nascent accretion disk, or with a filament of disrupted stellar gas near to the apocentre of an elliptical orbit. Flows of this sort are predicted by fundamental analytical theory and more recent numerical simulations. PMID:26490619

  10. Wake potential in a semi-elliptic pill-box cavity

    NASA Astrophysics Data System (ADS)

    Yang, J. S.; Chen, K. W.

    1989-10-01

    In this article we compared the wake potential in a cavity of semi-elliptic cross section and elliptic cross section. The semi-elliptic cavity is considered to have an advantage that we can experimentally simulate an elliptic cavity with one beam line. It is found that we can produce considerably strong accelerating fields inside this cavity. We calculate the resonant modes of this cavity using previous analytical mode analysis1. Also the wake field inside this cavity is derived analytically and numerical results are presented to determine the usefulness of this cavity.

  11. Excess ellipticity of hot and cold spots in the WMAP data?

    SciTech Connect

    Berntsen, Eirik; Hansen, Frode K. E-mail: frodekh@astro.uio.no

    2013-12-10

    We investigate claims of excess ellipticity of hot and cold spots in the Wilkinson Microwave Anisotropy Probe (WMAP) data. Using the cosmic microwave background (CMB) data from 7 yr of observations by the WMAP satellite, we find, contrary to previous claims of a 10σ detection of excess ellipticity in the 3 yr data, that the ellipticity of hot and cold spots is perfectly consistent with simulated CMB maps based on the concordance cosmology. We further test for excess obliquity and excess skewness/kurtosis of ellipticity and obliquity and find the WMAP7 data consistent with Gaussian simulated maps.

  12. Multigrid lattice Boltzmann method for accelerated solution of elliptic equations

    NASA Astrophysics Data System (ADS)

    Patil, Dhiraj V.; Premnath, Kannan N.; Banerjee, Sanjoy

    2014-05-01

    A new solver for second-order elliptic partial differential equations (PDEs) based on the lattice Boltzmann method (LBM) and the multigrid (MG) technique is presented. Several benchmark elliptic equations are solved numerically with the inclusion of multiple grid-levels in two-dimensional domains at an optimal computational cost within the LB framework. The results are compared with the corresponding analytical solutions and numerical solutions obtained using the Stone's strongly implicit procedure. The classical PDEs considered in this article include the Laplace and Poisson equations with Dirichlet boundary conditions, with the latter involving both constant and variable coefficients. A detailed analysis of solution accuracy, convergence and computational efficiency of the proposed solver is given. It is observed that the use of a high-order stencil (for smoothing) improves convergence and accuracy for an equivalent number of smoothing sweeps. The effect of the type of scheduling cycle (V- or W-cycle) on the performance of the MG-LBM is analyzed. Next, a parallel algorithm for the MG-LBM solver is presented and then its parallel performance on a multi-core cluster is analyzed. Lastly, a practical example is provided wherein the proposed elliptic PDE solver is used to compute the electro-static potential encountered in an electro-chemical cell, which demonstrates the effectiveness of this new solver in complex coupled systems. Several orders of magnitude gains in convergence and parallel scaling for the canonical problems, and a factor of 5 reduction for the multiphysics problem are achieved using the MG-LBM.

  13. Rayleigh wave ellipticity across the Iberian Peninsula and Morocco

    NASA Astrophysics Data System (ADS)

    Gómez García, Clara; Villaseñor, Antonio

    2015-04-01

    Spectral amplitude ratios between horizontal and vertical components (H/V ratios) from seismic records are useful to evaluate site effects, predict ground motion and invert for S velocity in the top several hundred meters. These spectral ratios can be obtained from both ambient noise and earthquakes. H/V ratios from ambient noise depend on the content and predominant wave types: body waves, Rayleigh waves, a mixture of different waves, etc. The H/V ratio computed in this way is assumed to measure Rayleigh wave ellipticity since ambient vibrations are dominated by Rayleigh waves. H/V ratios from earthquakes are able to determine the local crustal structure at the vicinity of the recording station. These ratios obtained from earthquakes are based on surface wave ellipticity measurements. Although long period (>20 seconds) Rayleigh H/V ratio is not currently used because of large scatter has been reported and uncertainly about whether these measurements are compatible with traditional phase and group velocity measurements, we will investigate whether it is possible to obtain stable estimates after collecting statistics for many earthquakes. We will use teleseismic events from shallow earthquakes (depth ≤ 40 km) between 2007 January 1 and 2012 December 31 with M ≥ 6 and we will compute H/V ratios for more than 400 stations from several seismic networks across the Iberian Peninsula and Morocco for periods between 20 and 100 seconds. Also H/V ratios from cross-correlations of ambient noise in different components for each station pair will be computed. Shorter period H/V ratio measurements based on ambient noise cross-correlations are strongly sensitive to near-surface structure, rather than longer period earthquake Rayleigh waves. The combination of ellipticity measurements based on earthquakes and ambient noise will allow us to perform a joint inversion with Rayleigh wave phase velocity. Upper crustal structure is better constrained by the joint inversion compared

  14. Two-dimensional gap solitons in elliptic-lattice potentials

    SciTech Connect

    He Yingji; Malomed, Boris A.; Hu Bambi

    2010-03-15

    We study two-dimensional (2D) matter-wave gap solitons trapped in an elliptically deformed concentric lattice potential, within the framework of the Gross-Pitaevskii equation (GPE) with self-attraction or self-repulsion. For a fixed eccentricity of the lattice, soliton families are found in both the repulsive and attractive models. In the former case, the analysis reveals two kinds of gap solitons trapped in the first oval trough (the ring-shaped potential minimum closest to the center): elliptic annular solitons (EASs), and double solitons (DSs), which are formed by two tightly localized density peaks located at diametrically opposite points of the trough, with zero phase difference between them. With the decrease of the norm, the density distribution in the EAS along the azimuthal direction changes from nearly uniform to double-peaked and, eventually, to the DS. In the attractive model, there exist only DSs in the oval trough, while EASs are not found. All such solitons without the angular momentum (l=0) are fully stable. For l{ne}0, vortical solitons--both EASs with a sufficiently large norm (in the repulsive model) and DSs (in models with both signs of the nonlinearity)--are quasistable, exhibiting rocking motion in the elliptic trough (we consider the cases of l=1 and l=2). At smaller values of the norm, the vortical annular solitons (in the repulsive model) are unstable. Stable fundamental solitons trapped in the central potential well are investigated, too, in both the attractive and repulsive models, by means of the variational approximation and numerical methods.

  15. Orbital structure and mass distribution in elliptical galaxies

    NASA Astrophysics Data System (ADS)

    Kronawitter, Andi; Saglia, R. P.; Gerhard, Ortwin; Bender, Ralf

    2000-05-01

    We report on a homogeneous dynamical analysis of a sample of 21 round (17 E0/E1, 4 E2) elliptical galaxies. We present new kinematic data for eight of these galaxies and new photometry for one object. The remaining kinematic and photometric data and the required distance information are taken from the literature. The analysis uses non-parametric spherical models and takes into account line profile information as well as velocity dispersions. We present model fits to the kinematic data and the derived radial profiles of orbital anisotropy and B-band mass-to-light ratio, including confidence intervals. The circular velocity curves resulting from our model fits are all consistent with being flat outside R~ 0.3 R_e. Generally, the M/L ratio profiles show an outward increase, although models based on luminous matter are ruled out at 95% confidence only for three galaxies (NGC 2434, NGC 7507, NGC 7626). For NGC 1399, NGC 4472, NGC 4486, and NGC 4636, where X-ray observations are available, the mass profiles of the best fit models match the ones derived from the X-ray analysis. The best models for most galaxies are isotropic to slightly radially anisotropic, with typical beta <~0.3, in a few cases beta <~0 .5 at R_e/2. We discuss the generally small effects of flattening along the line-of-sight (the expected = 0.79 for this sample of luminous ellipticals) and of small embedded disks. Our results suggest that elliptical galaxies have surprisingly uniform dynamical properties.

  16. Direct Detections of Young Stars in Nearby Elliptical Galaxies

    NASA Astrophysics Data System (ADS)

    Ford, H. Alyson; Bregman, Joel N.

    2013-06-01

    Small amounts of star formation in elliptical galaxies are suggested by several results: surprisingly young ages from optical line indices, cooling X-ray gas, and mid-infrared dust emission. Such star formation has previously been difficult to directly detect, but using ultraviolet Hubble Space Telescope Wide Field Camera 3 imaging, we have identified individual young stars and star clusters in four nearby ellipticals. Ongoing star formation is detected in all galaxies, including three ellipticals that have previously exhibited potential signposts of star-forming conditions (NGC 4636, NGC 4697, and NGC 4374), as well as the typical "red and dead" NGC 3379. The current star formation in our closest targets, where we are most complete, is between 2.0 and 9.8 × 10-5 M ⊙ yr-1. The star formation history was roughly constant from 0.5 to 1.5 Gyr (at (3-5) × 10-4 M ⊙ yr-1), but decreased by a factor of several in the past 0.3 Gyr. Most star clusters have a mass between 102 and 104 M ⊙. The specific star formation rates of ~10-16 yr-1 (at the present day) or ~10-14 yr-1 (when averaging over the past Gyr) imply that a fraction 10-8 of the stellar mass is younger than 100 Myr and 10-5 is younger than 1 Gyr, quantifying the level of frosting of recent star formation over the otherwise passive stellar population. There is no obvious correlation between either the presence or spatial distribution of postulated star formation indicators and the star formation we detect. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program 11583.

  17. Optical proximity correction challenges with highly elliptical contacts

    NASA Astrophysics Data System (ADS)

    Cork, Chris; Barnes, Levi; Ping, Yang; Li, Xiaohai; Jang, Stephen

    2010-09-01

    The steady march of Moore's law demands ever smaller feature sizes to be printed and Optical Proximity Correction to correct to ever tighter dimensional tolerances. Recently pitch doubling techniques has relieved the pressure on CD reduction, which instead of being achieved lithographically are reduced by subsequent etching or chemical interaction with spin-on layers. CD tolerance reductions, however, still need to match the overall design rule shrinkage. The move to immersion lithography, where effective Numerical Apertures now reach 1.35, has been accompanied by a significantly reduction in depth of focus, especially on isolated contacts. To remedy this, RET techniques such as assist feature placement, have been implemented. Certain local placements of assist features and neighboring contacts are observed to result in highly elliptical contacts being printed. In some layouts small changes in the aspect ratio of the contact on the mask leads to strong changes in the aspect ratio of the printed contact, whereas in other layouts the response is very weak. This effect can be described as an aspect ratio MEEF. The latter type of contact can pose a significant challenge to the OPC recipe which is driven by the need to place the printed contour within a small range of distance from target points placed on the midpoint of edges of a nominally square contact. The OPC challenge naturally will be compounded when the target layout is rectangular in the opposite sense to the natural elliptical shape of the printed contact. Approaches to solving this can vary from intervening at the assist feature placement stage, at the possible loss of depth of focus, to accepting a certain degree of ellipticity in the final contour and making the OPC recipe concentrate on minimizing any residual errors. This paper investigates which contact layouts are most challenging, discusses the compromises associated with achieving the correction target and results are shown from a few different

  18. DIRECT DETECTIONS OF YOUNG STARS IN NEARBY ELLIPTICAL GALAXIES

    SciTech Connect

    Ford, H. Alyson; Bregman, Joel N.

    2013-06-20

    Small amounts of star formation in elliptical galaxies are suggested by several results: surprisingly young ages from optical line indices, cooling X-ray gas, and mid-infrared dust emission. Such star formation has previously been difficult to directly detect, but using ultraviolet Hubble Space Telescope Wide Field Camera 3 imaging, we have identified individual young stars and star clusters in four nearby ellipticals. Ongoing star formation is detected in all galaxies, including three ellipticals that have previously exhibited potential signposts of star-forming conditions (NGC 4636, NGC 4697, and NGC 4374), as well as the typical ''red and dead'' NGC 3379. The current star formation in our closest targets, where we are most complete, is between 2.0 and 9.8 Multiplication-Sign 10{sup -5} M{sub Sun} yr{sup -1}. The star formation history was roughly constant from 0.5 to 1.5 Gyr (at (3-5) Multiplication-Sign 10{sup -4} M{sub Sun} yr{sup -1}), but decreased by a factor of several in the past 0.3 Gyr. Most star clusters have a mass between 10{sup 2} and 10{sup 4} M{sub Sun }. The specific star formation rates of {approx}10{sup -16} yr{sup -1} (at the present day) or {approx}10{sup -14} yr{sup -1} (when averaging over the past Gyr) imply that a fraction 10{sup -8} of the stellar mass is younger than 100 Myr and 10{sup -5} is younger than 1 Gyr, quantifying the level of frosting of recent star formation over the otherwise passive stellar population. There is no obvious correlation between either the presence or spatial distribution of postulated star formation indicators and the star formation we detect.

  19. A doubly curved elliptical crystal spectrometer for the study of localized x-ray absorption in hot plasmas

    NASA Astrophysics Data System (ADS)

    Cahill, Adam D.; Hoyt, Cad L.; Pikuz, Sergei A.; Shelkovenko, Tania; Hammer, David A.

    2014-10-01

    X-ray absorption spectroscopy is a powerful tool for the diagnosis of plasmas over a wide range of both temperature and density. However, such a measurement is often limited to probing plasmas with temperatures well below that of the x-ray source in order to avoid object plasma emission lines from obscuring important features of the absorption spectrum. This has excluded many plasmas from being investigated by this technique. We have developed an x-ray spectrometer that provides the ability to record absorption spectra from higher temperature plasmas than the usual approach allows without the risk of data contamination by line radiation emitted by the plasma under study. This is accomplished using a doubly curved mica crystal which is bent both elliptically and cylindrically. We present here the foundational work in the design and development of this spectrometer along with initial results obtained with an aluminum x-pinch as the object plasma.

  20. A doubly curved elliptical crystal spectrometer for the study of localized x-ray absorption in hot plasmas

    SciTech Connect

    Cahill, Adam D. Hoyt, Cad L.; Pikuz, Sergei A.; Shelkovenko, Tania; Hammer, David A.

    2014-10-15

    X-ray absorption spectroscopy is a powerful tool for the diagnosis of plasmas over a wide range of both temperature and density. However, such a measurement is often limited to probing plasmas with temperatures well below that of the x-ray source in order to avoid object plasma emission lines from obscuring important features of the absorption spectrum. This has excluded many plasmas from being investigated by this technique. We have developed an x-ray spectrometer that provides the ability to record absorption spectra from higher temperature plasmas than the usual approach allows without the risk of data contamination by line radiation emitted by the plasma under study. This is accomplished using a doubly curved mica crystal which is bent both elliptically and cylindrically. We present here the foundational work in the design and development of this spectrometer along with initial results obtained with an aluminum x-pinch as the object plasma.

  1. On finiteness of type IIB compactifications: magnetized branes on elliptic Calabi-Yau threefolds

    NASA Astrophysics Data System (ADS)

    Cvetič, Mirjam; Halverson, James; Klevers, Denis; Song, Peng

    2014-06-01

    The string landscape satisfies interesting finiteness properties imposed by supersymmetry and string-theoretical consistency conditions. We study = 1 supersymmetric compactifications of Type IIB string theory on smooth elliptically fibered Calabi-Yau threefolds at large volume with magnetized D9-branes and D5-branes. We prove that supersymmetry and tadpole cancellation conditions imply that there is a finite number of such configurations. In particular, we derive an explicitly computable bound on the number of magnetic flux quanta, as well as the number of D5-branes, which is independent of the continuous moduli of the setup. The proof applies if a number of easy to check geometric conditions of the twofold base are met. We show that these geometric conditions are satisfied for the almost Fano twofold bases given by each toric variety associated to a reflexive two-dimensional polytope as well as by the generic del Pezzo surfaces dP n with n = 0 ,…,8. Physically, this finiteness proof shows that there exist a finite collection of four-dimensional gauge groups and chiral matter spectra in the 4D supergravity theories realized by these compactifications. As a by-product we explicitly construct all generators of the Kähler cones of dP n and work out their relation to representation theory.

  2. Incomplete block factorization preconditioning for indefinite elliptic problems

    SciTech Connect

    Guo, Chun-Hua

    1996-12-31

    The application of the finite difference method to approximate the solution of an indefinite elliptic problem produces a linear system whose coefficient matrix is block tridiagonal and symmetric indefinite. Such a linear system can be solved efficiently by a conjugate residual method, particularly when combined with a good preconditioner. We show that specific incomplete block factorization exists for the indefinite matrix if the mesh size is reasonably small. And this factorization can serve as an efficient preconditioner. Some efforts are made to estimate the eigenvalues of the preconditioned matrix. Numerical results are also given.

  3. On an Elliptic Equation Arising from Composite Materials

    NASA Astrophysics Data System (ADS)

    Dong, Hongjie; Zhang, Hong

    2016-03-01

    In this paper, we derive an interior Schauder estimate for the divergence form elliptic equation D_i (a(x)D_iu) = D_i f_i in R^2 ,where {a(x)} and {f_i (x)} are piecewise Hölder continuous in a domain containing two touching balls as subdomains. When {f_i ≡ 0} and a is piecewise constant, we prove that u is piecewise smoothwith bounded derivatives.This completely answers a question raised by Li andVogelius (Arch Ration Mech Anal 153(2):91-151, 2000) in dimension 2.

  4. Some new addition formulae for Weierstrass elliptic functions

    PubMed Central

    Eilbeck, J. Chris; England, Matthew; Ônishi, Yoshihiro

    2014-01-01

    We present new addition formulae for the Weierstrass functions associated with a general elliptic curve. We prove the structure of the formulae in n-variables and give the explicit addition formulae for the 2- and 3-variable cases. These new results were inspired by new addition formulae found in the case of an equianharmonic curve, which we can now observe as a specialization of the results here. The new formulae, and the techniques used to find them, also follow the recent work for the generalization of Weierstrass functions to curves of higher genus. PMID:25383018

  5. Dynamical models of elliptical galaxies - I. Simple methods

    NASA Astrophysics Data System (ADS)

    Agnello, A.; Evans, N. W.; Romanowsky, A. J.

    2014-08-01

    We study dynamical models for elliptical galaxies, deriving the projected kinematic profiles in a form that is valid for general surface brightness laws and (spherical) total mass profiles, without the need for any explicit deprojection. We provide accurate approximations of the line of sight and aperture-averaged velocity dispersion profiles for galaxies with total mass density profiles with slope near -2 and with modest velocity anisotropy using only single or double integrals, respectively. This is already sufficient to recover many of the kinematic properties of nearby ellipticals. As an application, we provide two different sets of mass estimators for elliptical galaxies, based on either the velocity dispersion at a location at or near the effective radius, or the aperture-averaged velocity dispersion. In the large aperture (virial) limit, mass estimators are naturally independent of anisotropy. The spherical mass enclosed within the effective radius Re can be estimated as 2.4 R_e < σ 2_p > / G, where < σ ^2_p > is the average of the squared velocity dispersion over a finite aperture. This formula does not depend on assumptions such as mass-follows-light, and is a compromise between the cases of small and large aperture sizes. Its general agreement with results from other methods in the literature makes it a reliable means to infer masses in the absence of detailed kinematic information. If on the other hand the velocity dispersion profile is available, tight mass estimates can be found that are independent of the mass-model and anisotropy profile. In particular, for a de Vaucouleurs surface brightness, the velocity dispersion measured at ≈1Re yields a tight mass estimate (with 10 per cent accuracy) at ≈3Re that is independent of the mass model and the anisotropy profile. This allows us to probe the importance of dark matter at radii where it dominates the mass budget of galaxies. Explicit formulae are given for small anisotropy, large radii and/or power

  6. Effective material properties of thermoelectric composites with elliptical fibers

    NASA Astrophysics Data System (ADS)

    Wang, Yi-Ze

    2015-06-01

    In the present work, the effective material properties of thermoelectric composites with elliptical fibers are studied. Explicit solutions are derived by the conformal mapping function and Mori-Tanaka method. Numerical simulations are performed to present the behaviors of normalized effective material constants. From the results, it can be observed that both the effective electric and thermal conductivities can be reduced by increasing the filling ratio and a/ b. Such influences can also be found for the effective thermoelectric figure of merit. But they are different from those on the effective Seebeck and Peltier coefficients.

  7. Metallicity Gradients in the Halos of Elliptical Galaxies

    NASA Astrophysics Data System (ADS)

    Greene, Jenny E.; Ma, Chung-Pei; Goulding, Andrew; McConnell, Nicholas J.; Blakeslee, John P.; Davis, Timothy; Thomas, Jens

    2016-08-01

    We discuss the stellar halos of massive elliptical galaxies, as revealed by our ambitious integral-field spectroscopic survey MASSIVE. We show that metallicity drops smoothly as a function of radius out to ~ 2.5 Re , while the [α/Fe] abundance ratios stay flat. The stars in the outskirts likely formed rapidly (to explain the high ratio of alpha to Fe) but in a relatively shallow potential (to explain the low metallicities). This is consistent with expectations for a two-phase growth of massive galaxies, in which the second phase involves accretion of small satellites. We also show some preliminary study of the gas content of these most MASSIVE galaxies.

  8. Cavity modes and their excitations in elliptical plasmonic patch nanoantennas.

    PubMed

    Chakrabarty, Ayan; Wang, Feng; Minkowski, Fred; Sun, Kai; Wei, Qi-Huo

    2012-05-21

    We present experimental and theoretical studies of two dimensional periodic arrays of elliptical plasmonic patch nanoantennas. Experimental and simulation results demonstrate that the azimuthal symmetry breaking of the metal patches leads to the occurrence of even and odd resonant cavity modes and the excitation geometries dependent on their modal symmetries. We show that the cavity modes can be described by the product of radial and angular Mathieu functions with excellent agreements with both simulations and experiments. The effects of the patch periodicity on the excitation of the surface plasmon and its coupling with the cavity modes are also discussed. PMID:22714147

  9. Using elliptical best fits to characterize dental shapes.

    PubMed

    Bauer, Catherine C; Bons, Paul D; Benazzi, Stefano; Harvati, Katerina

    2016-02-01

    A variety of geometric morphometric methods have recently been used to describe dental shape variation in human evolutionary studies. However, the applicability of these methods is limited when teeth are worn or are difficult to orient accurately. Here we show that elliptical best fits on outlines of dental tissues below the crown provide basic size- and orientation-free shape descriptors. Using the dm(2) and M(3) as examples, we demonstrate that these descriptors can be used for taxonomic purposes, such as distinguishing between Neanderthal and recent modern human teeth. We propose that this approach can be a useful alternative to existing methodology. PMID:26381860

  10. The motion of elliptic cylinder under free surface

    NASA Astrophysics Data System (ADS)

    Kostikov, V. K.; Makarenko, N. I.

    2016-06-01

    A problem on generation of unsteady nonlinear waves on the surface of an infinitely deep ideal fluid due to the motion of a submerged elliptical cylinder is considered. It is supposed that the cylinder can rotate in addition to translational two-dimensional motion. The initial formulation of the problem is reduced to an integrodifferential system of equations for the functions defining the free surface shape, the normal and tangential components of velocity on the free boundary. The small-time asymptotics of the solution is constructed in the case of the cylinder that moves with a constant acceleration from rest.

  11. Conceptual design of a hybrid-type elliptically polarizing undulator

    NASA Astrophysics Data System (ADS)

    Sasaki, Shigemi

    2002-03-01

    A hybrid-type planar undulator was designed to generate circularly polarized radiation. It is an APPLE-type design consisting of four rows of hybrid structures that can be shifted with respect to each other. The magnetic field on axis can thus be adjusted so it can have linear or circular polarization including intermediate (elliptical polarization) positions. A short-period device of this kind can provide 100% circularly polarized radiation in a hard x-ray region when it is installed in a high-energy storage ring, such as the Advanced Photon Source.

  12. Chopper z-scan technique for elliptic Gaussian beams.

    PubMed

    Dávila-Pintle, J A; Reynoso-Lara, E; Bravo-García, Y E

    2016-09-01

    This paper reports an improvement to the chopper z-scan technique for elliptic Gaussian beams. This improvement results in a higher sensitivity by measuring the ratio of eclipsing time to rotating period (duty cycle) of a chopper that eclipses the beam along the main axis. It is shown that the z-scan curve of the major axis is compressed along the z-axis. This compression factor is equal to the ratio between the minor and major axes. It was found that the normalized peak-valley difference with respect to the linear value does not depend on the axis along which eclipsing occurs. PMID:27607713

  13. The origin of magnetic fields in elliptical galaxies

    NASA Astrophysics Data System (ADS)

    Shukurov, Anvar

    We argue that interstellar gas in elliptical galaxies can be turbulent, with turbulent scale and velocity of 400 pc and 20 km s-1 respectively. An upper limit on turbulent velocity, ~=50 km s-1, follows from the requirement that the turbulence dissipation rate does not exceed the X-ray gas luminosity. The turbulence can generate random magnetic fields of 0.3 μG strength at the above scale via fluctuation dynamo action. The resulting Faraday rotation is random, with a typical value of 5-30 rad m-2, consistent with observational evidence available.

  14. Protein phase diagrams: The physics behind their elliptic shape

    NASA Astrophysics Data System (ADS)

    Lesch, Harald; Hecht, Christoph; Friedrich, Josef

    2004-12-01

    We relate the condition for the elliptic shape of the phase diagram of proteins to the degree of correlation in the fluctuations of the changes of enthalpy and volume at the denaturing-refolding transition. Since this degree cannot be larger than 1, hyperbolically shaped diagrams are not likely to exist. Experiments show that the correlation factor is actually quite low for proteins implying that one-order parameter is not enough to describe the folding-denaturing transition. These findings seem to be the thermodynamic manifestation of the glasslike properties of proteins despite the fact that the transition itself is of first order.

  15. The construction of preconditioners for elliptic problems by substructuring, IV

    SciTech Connect

    Bramble, J.H.; Pasciak, J.E.; Schatz, A.H.

    1987-06-01

    We consider the problem of solving the algebraic system of equations which result from the discretization of elliptic boundary value problems defined on three dimensional Euclidean space. We develop preconditioners for such systems based on substructuring (also known as domain decomposition). The resulting algorithms are well suited to emerging parallel computing architectures. We describe two techniques for developing these precondictioners. A theory for the analysis of the condition number for the resulting preconditioned system is given and the results of supporting numerical experiments are presented. 16 refs., 2 tabs.

  16. Iterative schemes for nonsymmetric and indefinite elliptic boundary value problems

    SciTech Connect

    Bramble, J.H.; Leyk, Z.; Pasciak, J.E.

    1993-01-01

    The purpose of this paper is twofold. The first is to describe some simple and robust iterative schemes for nonsymmetric and indefinite elliptic boundary value problems. The schemes are based in the Sobolev space H ([Omega]) and require minimal hypotheses. The second is to develop algorithms utilizing a coarse-grid approximation. This leads to iteration matrices whose eigenvalues lie in the right half of the complex plane. In fact, for symmetric indefinite problems, the iteration is reduced to a well-conditioned symmetric positive definite system which can be solved by conjugate gradient interation. Applications of the general theory as well as numerical examples are given. 20 refs., 8 tabs.

  17. The construction of preconditioners for elliptic problems by substructuring, IV

    SciTech Connect

    Bramble, J.H.; Pasciak, J.E.; Schatz, A.H.

    1989-07-01

    We consider the problem of solving the algebraic system of equations which result from the discretization of elliptic boundary value problems defined on three-dimensional Euclidean space. We develop preconditioners for such systems based on substructuring (also known as domain decomposition). The resulting algorithms are well suited to emerging parallel computing architectures. We describe two techniques for developing these preconditioners. A theory for the analysis of the condition number for the resulting preconditioned system is given and the results of supporting numerical experiments are presented.

  18. Construction of preconditioners for elliptic problems by substructuring. II

    SciTech Connect

    Bramble, J.H.; Pasciak, J.E.; Schatz, A.H.

    1987-07-01

    We give a method for constructing preconditioners for the discrete systems arising in the approximation of solutions of elliptic boundary value problems. These preconditioners are based on domain decomposition techniques and lead to algorithms which are well suited for parallel computing environments. The method presented in this paper leads to a preconditioned system with condition number proportional to d/h where d is the subdomain size and h is the mesh size. These techniques are applied to singularly perturbed problems and problems in the three dimensions. The results of numerical experiments illustrating the performance of the method on problems in two and three dimensions are given.

  19. Iterative method for elliptic problems on regions partitioned into substructures

    SciTech Connect

    Bramble, J.H.; Pasciak, J.E.; Schatz, A.H.

    1986-04-01

    Some new preconditioners for discretizations of elliptic boundary problems are studied. With these preconditioners, the domain under consideration is broken into subdomains and preconditioners are defined which only require the solution of matrix problems on the subdomains. Analytic estimates are given which guarantee that under appropriate hypotheses, the preconditioned iterative procedure converges to the solution of the discrete equations with a rate per iteration that is independent of the number of unknowns. Numerical examples are presented which illustrate the theoretically predicted iterative convergence rates.

  20. Elliptic grid generation with orthogonality and spacing control on an arbitrary number of boundaries

    NASA Technical Reports Server (NTRS)

    White, J. A.

    1990-01-01

    A procedure for the generation of two and quasi-three-dimensional grids with control of orthogonality and spacing with respect to any and/or all boundaries of the domain is described. The elliptic grid generation equations of Thompson are solved implicitly. Control of the grid behavior is achieved through the introduction of forcing functions terms in the manner of Steger and Sorenson or in a modification of the method of Hilgenstock. The forcing function terms are constructed on the boundaries and propagated into the domain using transfinite Lagrangian bivariate interpolation. An anisotropic transfinite stencil is introduced and is shown to produce excellent grid behavior particularly in the vicinity of corner singularities. Emphasis is placed on the generation of viscous grids and the method is shown to be suited for use in the generation of grids for internal as well as external flow geometries. A FORTRAN program named PISCES has been written to implement the algorithm. Examples of grids for internal and external flows are given that highlight the characteristics and behavior of the algorithm.