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Sample records for h-alpha equivalent width

  1. H{alpha} EQUIVALENT WIDTHS FROM THE 3D-HST SURVEY: EVOLUTION WITH REDSHIFT AND DEPENDENCE ON STELLAR MASS

    Energy Technology Data Exchange (ETDEWEB)

    Fumagalli, Mattia; Patel, Shannon G.; Franx, Marijn; Labbe, Ivo [Leiden Observatory, Leiden University, P.O. Box 9513, 2300-RA Leiden (Netherlands); Brammer, Gabriel [European Southern Observatory, Alonso de Cordova 3107, Casilla 19001, Vitacura, Santiago (Chile); Van Dokkum, Pieter; Lundgren, Britt; Momcheva, Ivelina; Skelton, Rosalind E.; Whitaker, Katherine E.; Nelson, Erica [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Da Cunha, Elisabete; Rix, Hans-Walter; Schmidt, Kasper B. [Max Planck Institute for Astronomy (MPIA), Koenigstuhl 17, D-69117 Heidelberg (Germany); Kriek, Mariska [Department of Astronomy, University of California, Berkeley, CA 94720 (United States)

    2012-10-01

    We investigate the evolution of the H{alpha} equivalent width, EW(H{alpha}), with redshift and its dependence on stellar mass, using the first data from the 3D-HST survey, a large spectroscopic Treasury program with the Hubble Space Telescope Wide Field Camera 3. Combining our H{alpha} measurements of 854 galaxies at 0.8 < z < 1.5 with those of ground-based surveys at lower and higher redshift, we can consistently determine the evolution of the EW(H{alpha}) distribution from z = 0 to z = 2.2. We find that at all masses the characteristic EW(H{alpha}) is decreasing toward the present epoch, and that at each redshift the EW(H{alpha}) is lower for high-mass galaxies. We find EW(H{alpha}) {approx}(1 + z){sup 1.8} with little mass dependence. Qualitatively, this measurement is a model-independent confirmation of the evolution of star-forming galaxies with redshift. A quantitative conversion of EW(H{alpha}) to specific star formation rate (sSFR) is model dependent because of differential reddening corrections between the continuum and the Balmer lines. The observed EW(H{alpha}) can be reproduced with the characteristic evolutionary history for galaxies, whose star formation rises with cosmic time to z {approx} 2.5 and then decreases to z = 0. This implies that EW(H{alpha}) rises to 400 A at z = 8. The sSFR evolves faster than EW(H{alpha}), as the mass-to-light ratio also evolves with redshift. We find that the sSFR evolves as (1 + z){sup 3.2}, nearly independent of mass, consistent with previous reddening insensitive estimates. We confirm previous results that the observed slope of the sSFR-z relation is steeper than the one predicted by models, but models and observations agree in finding little mass dependence.

  2. K- and M-type dwarf stars within 25 parsecs of the sun. I. The age-chromospheric activity relations from H-alpha equivalent widths

    International Nuclear Information System (INIS)

    The available equivalent-width measurements of H-alpha in dwarf K and M stars within 25 pc of the sun indicate that, as a chromospheric diagnostic, the H-alpha decay rate is about t exp 0.5. The decay rate of line emission in Mg II h and k (Ca II H and K) is about t exp 0.3. The decay rates are derived from observations of members of a few stellar superclusters and groups, for which the consistency of results argues strongly for the importance of more data. The only major inconsistency encountered is for the unique HR 1614 group which, in the age/chromospheric-activity progression, gives different results from Mg II h and k and from WH-alpha. 63 refs

  3. ROBOSPECT: Automated Equivalent Width Measurement

    CERN Document Server

    Waters, Christopher Z

    2013-01-01

    We present ROBOSPECT, a new code to automatically measure and deblend line equivalent widths for both absorption and emission spectra. We test the accuracy of these measurements against simulated spectra as well as manual equivalent width measurements of five stellar spectra over a range of signal-to-noise values and a set of long slit emission spectra. We find that ROBOSPECT accurately matches both the synthetic and manual measurements, with scatter consistent with the expectations based on the data quality and the results of Cayrel (1988).

  4. PACCE: Perl Algorithm to Compute Continuum and Equivalent Widths

    OpenAIRE

    Riffel, Roge?rio; Vale, Tibe?rio Borges

    2011-01-01

    We present Perl Algorithm to Compute continuum and Equivalent Widths (pacce). We describe the methods used in the computations and the requirements for its usage. We compare the measurements made with pacce and "manual" ones made using iraf splot task. These tests show that for SSP models the equivalent widths strengths are very similar (differences

  5. ARES: Automatic Routine for line Equivalent widths in stellar Spectra

    Science.gov (United States)

    Sousa, Sérgio G.

    2012-05-01

    ARES was developed for the measurement of Equivalent Width of absortion lines in stellar spectra; it can also be used to determine fundamental spectroscopic stellar parameters.The code reads a 1D FITS spectra and fits the requested lines in order to calculate the Equivalent width. The code is written in C++ based on the standard method of determining EWs. It automates the manual procedure that one normally carries out when using interactive routines such as the splot routine implemented in IRAF.

  6. pacce: Perl algorithm to compute continuum and equivalent widths

    Science.gov (United States)

    Riffel, Rogério; Borges Vale, Tibério

    2011-08-01

    We present Perl Algorithm to Compute continuum and Equivalent Widths ( pacce). We describe the methods used in the computations and the requirements for its usage. We compare the measurements made with pacce and "manual" ones made using iraf splot task. These tests show that for synthetic simple stellar population (SSP) models the equivalent widths strengths are very similar (differences ?0.2 Å) for both measurements. In real stellar spectra, the correlation between both values is still very good, but with differences of up to 0.5 Å. pacce is also able to determine mean continuum and continuum at line center values, which are helpful in stellar population studies. In addition, it is also able to compute the uncertainties in the equivalent widths using photon statistics. The code is made available for the community through the web at http://www.if.ufrgs.br/~riffel/software.html .

  7. PACCE: Perl Algorithm to Compute Continuum and Equivalent Widths

    CERN Document Server

    Riffel, Rogério

    2011-01-01

    We present Perl Algorithm to Compute continuum and Equivalent Widths (pacce). We describe the methods used in the computations and the requirements for its usage. We compare the measurements made with pacce and "manual" ones made using iraf splot task. These tests show that for SSP models the equivalent widths strengths are very similar (differences <0.2A) for both measurements. In real stellar spectra, the correlation between both values is still very good, but with differences of up to 0.5A. pacce is also able to determine mean continuum and continuum at line center values, which are helpful in stellar population studies. In addition, it is also able to compute the uncertainties in the equivalent widths using photon statistics. The code is made available for the community through the web at http://www.if.ufrgs.br/~riffel/software.html.

  8. TAME: Tool for Automatic Measurement of Equivalent-width

    Science.gov (United States)

    Kang, Wonseok; Lee, Sang-Gak

    2015-03-01

    TAME measures the equivalent width (EWs) in high-resolution spectra. Written by IDL, TAME provides the EWs of spectral lines by profile fitting in an automatic or interactive mode and is reliable for measuring EWs in a spectrum with a spectral resolution of R â?³ 20000. It offers an interactive mode for more flexible measurement of the EW and a fully automatic mode that can simultaneously measure the EWs for a large set of lines.

  9. Tool for Automatic Measurement of Equivalent width (TAME)

    Science.gov (United States)

    Kang, Wonseok; Lee, Sang-Gak

    2012-10-01

    We present a tool for measuring the equivalent width (EW) in high-resolution spectra. The Tool for Automatic Measurement of Equivalent width (TAME) provides the EWs of spectral lines by profile fitting in an automatic or interactive mode, which can yield a more precise result through the adjustment of the local continuum and fitting parameters. The automatic EW results of TAME have been verified by comparing them with the manual EW measurements by the IRAF splot task using the high-resolution spectrum of the Sun and measuring EWs in the synthetic spectra with different spectral resolutions and signal-to-noise (S/N) ratios. The EWs measured by TAME agree well with the manually measured values, with a dispersion of less than 2 mÅ. By comparing the input EWs for synthetic spectra and EWs measured by TAME, we conclude that it is reliable for measuring the EWs in a spectrum with a spectral resolution of R ? 20 000 and find that the errors in EWs are less than 1 mÅ for an S/N ratio ?100.

  10. Tool for Automatic Measurement of Equivalent width (TAME)

    CERN Document Server

    Kang, Wonseok

    2012-01-01

    We present a tool for measuring the equivalent width (EW) in high-resolution spectra. The Tool for Automatic Measurement of Equivalent width (TAME)provides the EWs of spectral lines by profile fitting in the automatic or the interactive mode, which can yield a more precise result through the adjustment of the local continuum and fitting parameters. The automatic EW results of TAME have been verified by comparing them with the manual EW measurements by IRAF splot task using the high-resolution spectrum of the Sun, and measuring EWs in the synthetic spectra with different spectral resolutions and S/N ratios. The EWs measured by TAME agree well with manually measured values, with a dispersion of less than 2 mA. By comparing the input EWs for synthetic spectra and EWs measured by TAME, we conclude that it is reliable for measuring the EWs in a spectrum with a spectral resolution, R > 20000 and find that the errors in EWs is less than 1 mA for a S/N ratio > 100.

  11. FUNDPAR: A program for Deriving Fundamental Parameters from Equivalent Widths

    Scientific Electronic Library Online (English)

    C, Saffe.

    2011-04-01

    Full Text Available Implementamos un programa en Fortran que determina parámetros fundamentales de estrellas de tipo solar, a partir de anchos equivalentes del Fe. La solución debe verificar tres condiciones en el método estándar: equilibrio de ionización, equilibrio de excitación e independencia entre abundancias y an [...] chos equivalentes. Calculamos modelos de atmósfera de Kurucz con opacidades NEWODF. Detalles como el parámetro de longitud de mezcla, el sobre impulso convectivo, etc. se calculan con un programa independiente. FUNDPAR calcula las incertezas por dos métodos: el criterio de Gonzalez & Vanture (1998) y utilizando la función ?² . Los resultados derivados con FUNDPAR están de acuerdo con determinaciones previas en la literatura. En particular obtuvimos parámetros fundamentales de 58 estrellas con exoplanetas. El programa está disponible en la red1. Abstract in english We implemented a Fortran code that determines fundamental parameters of solar type stars from a list of Fe line equivalent widths. The solution should verify three conditions in the standard method: ionization equilibrium, excitation equilibrium and independence between metallicity and equivalent wi [...] dths. Solarscaled Kurucz model atmospheres with NEWODF opacities are calculated with an independent program. Parameter files control different details, such as the mixinglength parameter and the overshooting. FUNDPAR derives the uncertainties following two methods: the criterion of Gonzalez & Vanture (1998) and the dispersion using the ?2 function. The code uses the 2009 version of the MOOG program. The results derived with FUNDPAR are in agreement with previous determinations in the literature. The program is freely available from the web1.

  12. A new code for automatic determination of equivalent widths: Automatic Routine for line Equivalent widths in stellar Spectra (ARES)

    CERN Document Server

    Sousa, S G; Israelian, G; Mayor, M; Monteiro, M J P F G

    2007-01-01

    We present a new automatic code (ARES) for determining equivalent widths of the absorption lines present in stellar spectra. We also describe its use for determining fundamental spectroscopic stellar parameters. The code is written in C++ based on the standard method of determining EWs and is available for the community. The code automates the manual procedure that the users normally carry out when using interactive routines such as the splot routine implemented in IRAF. We test the code using both simulated and real spectra with different levels of resolution and noise and comparing its measurements to the manual ones obtained in the standard way. The results shows a small systematic difference, always below 1.5m\\AA. This can be explained by errors in the manual measurements caused by subjective continuum determination. The code works better and faster than others tested before.

  13. A New Code for Automatic Determination of Equivalent Widths: Automatic Routine for Line Equivalent Widths in Stellar Spectra (ARES)

    Science.gov (United States)

    Sousa, Sergio A. Gonçalves; Santos, Nuno Cardoso; Monteiro, M. J. P. F. G.; Israelian, Garik; Mayor, Michel

    2007-08-01

    We present a new automatic code (ARES) for the determination of equivalent widths of absorption lines present in stellar spectra. We also describe its use for the determination of fundamental spectroscopic stellar parameters. The code is written in C++ based on the standard method of determining EWs, and is available for the community. The code automates the manual procedure that the users normally carry out when using interactive routines such as the splot routine implemented in IRAF. We test the code using both simulated and real spectra with different levels of resolution and noise comparing its measurements to the manual ones obtained in the standard way. The results shows a small systematic difference, always bellow 1.5mA. This can be explained by errors in the manual measurements due to subjective continuum determination. The code works better and faster than others tested before. This code will be used to analyze spectra from the HARPS sample to search extrasolar planets.

  14. The distribution of equivalent widths in long GRB afterglow spectra

    CERN Document Server

    Postigo, A de Ugarte; Thoene, C C; Christensen, L; Gorosabel, J; Milvang-Jensen, B; Schulze, S; Jakobsson, P; Wiersema, K; Sanchez-Ramirez, R; Leloudas, G; Zafar, T; Malesani, D; Hjorth, J

    2012-01-01

    The extreme brightness of gamma-ray burst (GRB) afterglows and their simple spectral shape make them ideal beacons to study the interstellar medium of their host galaxies through absorption line spectroscopy. Using 69 low-resolution GRB afterglow spectra, we conduct a study of the rest-frame equivalent width (EW) distribution of features with an average rest-frame EW larger than 0.5 A. To compare an individual GRB with the sample, we develop EW diagrams as a graphical tool, and we give a catalogue with diagrams for the 69 spectra. We introduce a line strength parameter (LSP) that allows us to quantify the strength of the absorption features as compared to the sample by a single number. Using the distributions of EWs of single-species features, we derive the distribution of column densities by a curve of growth (CoG) fit. We find correlations between the LSP and the extinction of the GRB, the UV brightness of the host galaxies and the neutral hydrogen column density. However, we see no significant evolution of...

  15. H{\\alpha} photometry of low mass stars in 47 Tucanae: chromospheric activity and exotica

    CERN Document Server

    Beccari, G; Panagia, N; Pasquini, L

    2013-01-01

    We have used archival Hubble Space Telescope observations obtained with the Advanced Camera for Surveys to study the H{\\alpha} emission properties of main sequence stars in the globular cluster 47 Tucanae. Using a combination of multi-band observations in the F606W, F814W and F658N bands, we search for stars showing H{\\alpha} excess emission. An accurate photometric measurement of their H{\\alpha} equivalent width allows us to identify objects with large H{\\alpha} emission, which we attribute to mass accretion rather than enhanced chromospheric activity. The spatial position of some of these stars is coincident with that of known X-ray sources and their location in the colour-magnitude diagram allows us to classify them as active binaries or cataclysmic variables (CVs). We show that this method, commonly adopted to study accreting discs in young stellar objects, can be successfully used to identify and characterise candidate CVs.

  16. The chemical composition of the extreme halo stars. III. Equivalent widths of 20 dwarfs

    International Nuclear Information System (INIS)

    In the first two papers of this series we discussed the chemical composition of 20 extreme halo stars. The abundances of a number of elements were determined using model atmosphere analysis of equivalent widths from the Cassegrain Echelle Spectrograph (CASPEC) attached to the 3.6 m telescope at the European Southern Observatory (La Silla, Chile). In this paper we present a tabulation of the equivalent width data. A comparison of our measurements with the equivalent widths from different sources allows to assess the quality of our data

  17. A modified equivalent-width technique for diode-laser line strength measurements

    Science.gov (United States)

    Strow, L. Larrabee; Zheng, Liu

    1989-01-01

    A modified equivalent-width method is introduced that improves the accuracy of spectral line strength measurements using diode lasers. This method differs from the standard method in that no attempt is made to calculate the true equivalent width in order to determine the line strength. Instead, the line strength is derived directly from a measurement of the area under the line close to the line center and ignore the normal correction terms. Tests with actual spectra and simulations indicate that this method is accurate to better than 1 percent with lines broadened by up to 50 percent by the laser instrument function.

  18. VizieR Online Data Catalog: Pal1-I elemental equivalent widths and abundances (Monaco+, 2011)

    Science.gov (United States)

    Monaco, L.; Saviane, I.; Correnti, M.; Bonifacio, P.; Geisler, D.

    2010-11-01

    Table A1. reports the line list and atomic parameters adopted for the Palomar 1 giant Pal1-I and the Sun. For the Mn and Co lines we adopted the hyperfine structures (HFS) tabulated by Prochaska et al. (2000AJ....120.2513P). The measured equivalent width and the corresponding abundance obtained for each line are also reported. (1 data file).

  19. VizieR Online Data Catalog: Equivalent widths of 5 giants in 47 Tuc (Alves-Brito+, 2005)

    Science.gov (United States)

    Alves-Brito, A.; Barbuy, B.; Ortolani, S.; Momany, I.; Hill, V.; Zoccali, M.; Renzini, A.; Minniti, D.; Pasquini, L.; Bica, E.; Rich, R. M.

    2005-02-01

    Equivalent widths (EW) measured for Fe I and Fe II lines using IRAF task SPLOT and DAOSPEC. Column one gives the wavelength, column two the atomic species. Columns three and four give the excitation potential (EP) and gf-values, respectively. Columns 5-9 give the measured equivalent widths for the five stars of the sample using IRAF, while Columns 10-14 give the equivalent widths obtained using DAOSPEC. (2 data files).

  20. H-alpha observations of the gamma-ray-emitting Be/X-ray binary LSI+61303: orbital modulation, disk truncation, and long-term variability

    CERN Document Server

    Zamanov, R; Marti, J; Tomov, N A; Belcheva, G; Luque-Escamilla, P L; Latev, G

    2013-01-01

    We report 138 spectral observations of the H-alpha emission line of the radio- and gamma-ray-emitting Be/X-ray binary LSI+61303 obtained during the period of September 1998 -- January 2013. From measuring various H-alpha parameters, we found that the orbital modulation of the H-alpha is best visible in the equivalent width ratio EW(B)/EW(R), the equivalent width of the blue hump, and in the radial velocity of the central dip. The periodogram analysis confirmed that the H-alpha emission is modulated with the orbital and superorbital periods. For the past 20 years the radius of the circumstellar disk is similar to the Roche lobe size at the periastron. It is probably truncated by a 6:1 resonance. The orbital maximum of the equivalent width of H-alpha emission peaks after the periastron and coincides on average with the X-ray and gamma-ray maxima. All the spectra are available upon request from the authors and through the CDS.

  1. On the H$\\alpha$ Behaviour of Blue Supergiants: Rise and Fall over the Bi-stability Jump

    CERN Document Server

    Petrov, Blagovest; Gräfener, Götz

    2014-01-01

    The evolutionary state of blue supergiants is still unknown. Stellar wind mass loss is one of the dominant processes determining the evolution of massive stars, and it may provide clues on the evolutionary properties of blue supergiants. As the H$\\alpha$ line is the most oft-used mass-loss tracer in the OB-star regime, we provide a detailed analysis of the H$\\alpha$ line for OB supergiant models over an $T_{\\rm eff}$ range between 30000 and 12500K. We find a maximum in the H$\\alpha$ equivalent width at 22500 K - at the location of the bi-stability jump. The H$\\alpha$ line-profile behaviour is characterised by two branches of $T_{\\rm eff}$: (i) a "hot" branch between 30000 and 22500 K, where H$\\alpha$ emission becomes stronger with decreasing $T_{\\rm eff}$, and (ii) a "cool" branch between 22500 and 12500 K, where the line becomes weaker. Our models show that this non-monotonic H$\\alpha$ behaviour is related to the optical depth of Ly$\\alpha$, finding that at the "cool" branch the population of the 2nd level o...

  2. H$\\alpha$ and EUV observations of a partial CME

    CERN Document Server

    Christian, Damian J; Antolin, Patrick; Mathioudakis, Mihalis

    2015-01-01

    We have obtained H$\\alpha$ high spatial and time resolution observations of the upper solar chromosphere and supplemented these with multi-wavelength observations from the Solar Dynamic Observatory (SDO) and the {\\it Hinode} ExtremeUltraviolet Imaging Spectrometer (EIS). The H$\\alpha$ observations were conducted on 11 February 2012 with the Hydrogen-Alpha Rapid Dynamics Camera (HARDcam) instrument at the National Solar Observatory's Dunn Solar Telescope. Our H$\\alpha$ observations found large downflows of chromospheric material returning from coronal heights following a failed prominence eruption. We have detected several large condensations ("blobs") returning to the solar surface at velocities of $\\approx$200 km s$^{-1}$ in both H$\\alpha$ and several SDO AIA band passes. The average derived size of these "blobs" in H$\\alpha$ is 500 by 3000 km$^2$ in the directions perpendicular and parallel to the direction of travel, respectively. A comparison of our "blob" widths to those found from coronal rain, indicate...

  3. A DEEP, WIDE-FIELD H{alpha} SURVEY OF NEARBY CLUSTERS OF GALAXIES: DATA

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Shoko [Division of Astronomy and Astrophysics, University of California, Los Angeles, Los Angeles, CA 90095-1562 (United States); Kennicutt, Robert C. Jr. [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Moss, Chris [Astrophysics Research Institute, Liverpool John Moores University, Birkenhead CH41 1LD (United Kingdom)

    2012-04-01

    We present the results of a wide-field H{alpha} imaging survey of eight nearby (z = 0.02-0.03) Abell clusters. We have measured H{alpha} fluxes and equivalent widths for 465 galaxies, of which 360 are new detections. The survey was designed to obtain complete emission-line-selected inventories of star-forming galaxies in the inner regions of these clusters, extending to star formation rates below 0.1 M{sub Sun} yr{sup -1}. This paper describes the observations, data processing, and source identification procedures, and presents an H{alpha} and R-band catalog of detected cluster members and other candidates. Future papers in the series will use these data to study the completeness of spectroscopically based star formation surveys, and to quantify the effects of cluster environment on the present-day populations of star-forming galaxies. The data will also provide a valuable foundation for imaging surveys of redshifted H{alpha} emission in more distant clusters.

  4. A principal component analysis of the equivalent widths of spectral lines of star clusters

    Science.gov (United States)

    Li, Cheng; Kong, Xu; Cheng, Fu-zhen

    Using principal component analysis, we have studied the equivalent widths of optical spectral lines of 41 Galactic globular clusters and 22 young stellar clusters. We have discovered that some characteristic spectral lines, such as the CN, Ca IIK, Ca IIH and MgI+MgII lines, are rather sensitive to metallicity. We have also found some lines that may be used as indicators of age, e.g. H?, H?, H? and H?. These lines can help us to disentangle the coupling effects of age and metallicity in the clusters.

  5. UV/H-alpha Turmoil

    OpenAIRE

    Lee, Janice C.; Paz, Armando Gil; Tremonti, Christy; Kennicutt, Robert; Team, The Local Volume Legacy

    2010-01-01

    A great deal of our understanding of star formation in the local universe has been built upon an extensive foundation of H-alpha observational studies. However, recent work in the ultraviolet (UV) with GALEX has shown that star formation rates (SFRs) inferred from H-alpha in galactic environments characterized by low stellar and gas densities tend to be less than those based on the UV luminosity. The origin of the discrepancy is actively debated because one possible explanat...

  6. Bayesian Identification of Emission-Line Galaxies with Photometric Equivalent Widths

    Science.gov (United States)

    Leung, Andrew S.; Gawiser, Eric J.; Acquaviva, Viviana; Hetdex Collaboration

    2015-01-01

    We present a Bayesian approach to the classification of emission-line galaxies as an alternative to the traditional limit of requiring Lyman-alpha emitting (LAE) galaxies to have rest-frame equivalent width (EW) > 20 Angstroms. The Bayesian method relies on known distributions of line luminosities and equivalent widths as prior probabilities and returns the probability that an object is an LAE given the observed characteristics. This will be directly relevant for the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX), which seeks to classify more than a million emission-line galaxies into LAEs and low-redshift [O II] emitters. For a simulated HETDEX catalog with realistic measurement noise, the Bayesian method recovers a majority of the LAEs missed by the EW > 20 Angstroms cutoff over 2 20 Angstroms cut in contamination (false positives) and incompleteness (false negatives). Trade-off between contamination and incompleteness can be achieved by adjusting the stringency of the probability requirement for classifying an observed object as an LAE. A basic implementation of the Bayesian reduces errors in cosmological parameters by ~22%, which is equivalent to obtaining ~40% more data. The inclusion of the color of the galaxies, contingent on the availability of this information, increases the discriminating power of Bayesian separation and results in further reductions in errors. The Bayesian method is also being used to determine which single broadband filter produces the best performance. This method would enable large-scale structure analyses to be performed directly on emission-line objects labeled with probabilities of being LAEs rather than splitting the sample into LAEs and [O II] emitters.We gratefully acknowledge support from NSF through grant AST-1055919.

  7. WINGS-SPE III: Equivalent width measurements, spectral properties and evolution of local cluster galaxies

    CERN Document Server

    Fritz, J; Cava, A; Moretti, A; Varela, J; Bettoni, D; Couch, W J; D'Onofrio, M; Dressler, A; Fasano, G; Kjaergaard, P; Marziani, P; Moles, M; Omizzolo, A

    2014-01-01

    [Abridged] We investigate the frequency of the various spectral types as a function both of the clusters' properties and of the galaxies' characteristics. In this way, using the same classification criteria adopted for higher redshift studies, we can consistently compare the properties of the local cluster population to those of their more distant counterparts. We describe a method we have developed to automatically measure the equivalent width of spectral lines in a robust way even in spectra with a non optimal signal to noise. Like this, we can derive a spectral classification reflecting the stellar content, based on the presence and strength of the [OII] and Hdelta lines. We are able to measure 4381 of the ~6000 originally observed spectra, in the fields of 48 clusters, 2744 of which are spectroscopically confirmed cluster members. The spectral classification is then analyzed as a function of galaxies' luminosity, stellar mass, morphology, local density and host cluster's global properties, and compared to...

  8. VizieR Online Data Catalog: Equivalent width of 21 RR Lyrae stars (Pancino+, 2015)

    Science.gov (United States)

    Pancino, E.; Britavskiy, N.; Romano, D.; Cacciari, C.; Mucciarelli, A.; Clementini, G.

    2015-02-01

    Equivalent widths and atomic data of the absorption lines used in the abundance analysis, for each separate exposure at different phases. Observations of 15 RR Lyrae stars (DR And, X Ari, TW Boo, RZ Cam, RX Cet, U Com, RV CrB, SW CVn, UZ CVn, AE Dra, SZ Gem, VX Her, DH Hya, TU UMa, and RV UMa) and one BL Her star (UY Eri) were carried out with SARG@TNG, operated on the island of La Palma, Spain, during two separate runs in 2009 March and between September and November. Eight stars (SW Aqr, TW Cap, DH Hya, V Ind, SS Leo, V716 Oph, BK Tuc, and UV Vir) were observed with UVES@VLT, between 2009 April and August in service mode. (3 data files).

  9. Spatial resolution in imaging systems: Equivalent width a realistic measure to replace FWHM

    International Nuclear Information System (INIS)

    It was the purpose of the study to discuss and recommend a realistic measure for the spatial resolution in nuclear medicine imaging systems. If the assumption of a gaussian line spread function is fulfilled, the resolution index FWHM describes the associated frequency transfer function as well. In the case of septal penetration and scattering this basic assumption is no longer valid. So FWHM has no relevance with respect to transfer characteristics. Therefore equivalent width (EW) and autocorrelation width (AW), well known parameters in signal theory, are examined concerning a realistic measure of spatial resolution. These parameters are connected to line spread functions (LSF) and modulation transfer functions (MTF) regardless of its analytical form. Two cold spheres (20mm and 30mm phi) in a Tc-99m filled disc phantom were imaged with a gamma camera (LEAP collimator) in a 20 cm source collimator distance, with air and water as a scattering medium. Resolution indices and image contrast, C: = (non target-target)/non target, are summarized. The authors conclude that contrast changes caused by scatter are much better reflected by changes of EW than FWHM. Therefore they recommend EW as a realistic resolution index for imaging quality in nuclear medicine. AW seems by its definition suitable for quantitation purposes

  10. Photometry and H$alpha$ studies of a Low Mass Ratio Overcontact binary ASAS J082243+1927.0

    CERN Document Server

    Sriram, K; Rao, P Vivekananda

    2014-01-01

    Both high precision CCD photometric and H$alpha$ line studies are presented for an overcontact binary ASAS J082243+1927.0. The light curve exhibits a total eclipse at secondary minima along with an O'Connell effect. The light curve was modeled using the Wilson Devinney code and the best solution provides the mass ratio q = 0.106 and fill-out factor f = 72%. These parameters indicate that the system is a low mass ratio overcontact binary with a high degree of geometrical contact. The H alpha line equivalent width varied at different phases and it is found that the line is possibly filled-in at secondary minima. From a small sample of overcontact binaries, we found a correlation between the orbital period and H alpha line equivalent width of the primary component. Based on a sample of high filling factor and low mass ratio contact binaries, a mass ratio cut-off is observed at q = 0.085 in mass ratio - period plane. It was observed that below q $\\le$ 0.085, period decreases with an increase in q and above it, pe...

  11. A Pipeline for the Analysis of APOGEE Spectra Based on Equivalent Widths

    Science.gov (United States)

    Arfon Williams, Rob; Bosley, Corinne; Jones, Hayden; Schiavon, Ricardo P.; Allende-Prieto, Carlos; Bizyaev, Dmitry; Carrera, Ricardo; Cunha, Katia M. L.; Nguyen, Duy; Feuillet, Diane; Frinchaboy, Peter M.; García Pérez, Ana; Hasselquist, Sten; Hayden, Michael R.; Hearty, Fred R.; Holtzman, Jon A.; Johnson, Jennifer; Majewski, Steven R.; Meszaros, Szabolcs; Nidever, David L.; Shetrone, Matthew D.; Smith, Verne V.; Sobeck, Jennifer; Troup, Nicholas William; Wilson, John C.; Zasowski, Gail

    2015-01-01

    The Apache Point Galactic Evolution Experiment (APOGEE) forms part of the third Sloan Digital Sky Survey and has obtained high resolution, high signal-to-noise infrared spectra for ~1.3 x 105 stars across the galactic bulge, disc and halo. From these, stellar parameters are derived together with abundances for various elements using the APOGEE Stellar Parameters and Chemical Abundance Pipeline (ASPCAP). In this poster we report preliminary results from application of an alternative stellar parameters and abundances pipeline, based on measurements of equivalent widths of absorption lines in APOGEE spectra. The method is based on a sequential grid inversion algorithm, originally designed for the derivation of ages and elemental abundances of stellar populations from line indices in their integrated spectra. It allows for the rapid processing of large spectroscopic data sets from both current and future surveys, such as APOGEE and APOGEE 2, and it is easily adaptable for application to other very large data sets that are being/will be generated by other massive surveys of the stellar populations of the Galaxy. It will also allow the cross checking of ASPCAP results using an independent method. In this poster we present preliminary results showing estimates of effective temperature and iron abundance [Fe/H] for a subset of the APOGEE sample, comparing with DR12 numbers produced by the ASPCAP pipeline.

  12. On the (Non-)Enhancement of the Ly? Equivalent Width by a Multiphase Interstellar Medium

    DEFF Research Database (Denmark)

    Laursen, Peter; Duval, F.

    2013-01-01

    It has been suggested that radiative transfer effects may explain the unusually high equivalent widths (EWs) of the Lya line, observed occasionally from starburst galaxies, especially at high redshifts. If the dust is locked up inside high-density clouds dispersed in an empty intercloud medium, the Lya photons could scatter off of the surfaces of the clouds, effectively having their journey confined to the dustless medium. The continuum radiation, on the other hand, does not scatter, and would thus be subject to absorption inside the clouds. This scenario is routinely invoked when Lya EWs higher than what is expected theoretically are observed, although the ideal conditions under which the results are derived usually are not considered. Here we systematically examine the relevant physical parameters in this idealized framework, testing whether any astrophysically realistic scenarios may lead to such an effect. It is found that although clumpiness indeed facilitates the escape of Lya, it is highly unlikely that any real interstellar media should result in a preferential escape of Lya over continuum radiation. Other possible causes are discussed, and it is concluded that the observed high EWs are more likely to be caused by cooling radiation from cold accretion and/or anisotropic escape of the Lya radiation. © 2013. The American Astronomical Society. All rights reserved.

  13. WINGS-SPE. III. Equivalent width measurements, spectral properties, and evolution of local cluster galaxies

    Science.gov (United States)

    Fritz, J.; Poggianti, B. M.; Cava, A.; Moretti, A.; Varela, J.; Bettoni, D.; Couch, W. J.; D'Onofrio D'Onofrio, M.; Dressler, A.; Fasano, G.; Kjærgaard, P.; Marziani, P.; Moles, M.; Omizzolo, A.

    2014-06-01

    Context. Cluster galaxies are the ideal sites to look at when studying the influence of the environment on the various aspects of the evolution of galaxies, such as the changes in their stellar content and morphological transformations. In the framework of wings, the WIde-field Nearby Galaxy-cluster Survey, we have obtained optical spectra for ~6000 galaxies selected in fields centred on 48 local (0.04 classification criteria adopted for studies at higher redshift, we can consistently compare the properties of the local cluster population to those of their more distant counterparts. Methods: We describe a method that we have developed to automatically measure the equivalent width of spectral lines in a robust way, even in spectra with a non optimal signal-to-noise ratio. This way, we can derive a spectral classification reflecting the stellar content, based on the presence and strength of the [Oii] and H? lines. Results: After a quality check, we are able to measure 4381 of the ~6000 originally observed spectra in the fields of 48 clusters, of which 2744 are spectroscopically confirmed cluster members. The spectral classification is then analysed as a function of galaxies' luminosity, stellar mass, morphology, local density, and host cluster's global properties and compared to higher redshift samples (MORPHS and EDisCS). The vast majority of galaxies in the local clusters population are passive objects, being also the most luminous and massive. At a magnitude limit of MV < -18, galaxies in a post-starburst phase represent only ~11% of the cluster population, and this fraction is reduced to ~5% at MV < -19.5, which compares to the 18% at the same magnitude limit for high-z clusters. "Normal" star-forming galaxies (e(c)) are proportionally more common in local clusters. Conclusions: The relative occurrence of post-starbursts suggests a very similar quenching efficiency in clusters at redshifts in the 0 to ~1 range. Furthermore, more important than the global environment, the local density seems to be the main driver of galaxy evolution in local clusters at least with respect to their stellar populations content. Based on observations taken at the Anglo Australian Telescope (3.9 m- AAT) and at the William Herschel Telescope (4.2 m-WHT).Full Table A.1 is available in electronic form at both the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/566/A32 and by querying the wings database at http://web.oapd.inaf.it/wings/new/index.htmlAppendices are available in electronic form at http://www.aanda.org

  14. The H alpha Galaxy Survey. VIII. Close companions and interactions, and the definition of starbursts

    CERN Document Server

    Knapen, Johan H

    2009-01-01

    (Shortened) We consider the massive star formation properties, radial profiles, and atomic gas masses of those galaxies in our H alpha Galaxy Survey, a representative sample of the local Universe of 327 disk galaxies, that have close companion galaxies, in comparison with a matched control sample of galaxies without companions. We find that the presence of a close companion raises the star formation rate by a factor of just under two, while increasing hardly at all the equivalent width of the H alpha emission. This means that although statistically galaxies with close companions form stars at a higher rate, they do this over extended periods of time, and not as bursts. We find no significant increase in the central concentration of the star formation as a result of the presence of a close companion. The fraction of truly interacting or merging galaxies is very small in the local Universe, at around 2%, and possibly 4% of bright galaxies. Most of these interacting galaxies currently have unremarkable star form...

  15. Emission-line stars discovered in the UKST H-alpha survey of the Large Magellanic Cloud; Part 1: Hot stars

    CERN Document Server

    Reid, Warren A

    2012-01-01

    We present new, accurate positions, spectral classifications, radial and rotational velocities, H-alpha fluxes, equivalent widths and B,V,I,R magnitudes for 579 hot emission-line stars (classes B0 - F9) in the Large Magellanic Cloud which include 469 new discoveries. Candidate emission line stars were discovered using a deep, high resolution H-alpha map of the central 25 deg2 of the LMC obtained by median stacking a dozen 2 hour H-alpha exposures taken with the UK Schmidt Telescope. Spectroscopic follow-up observations on the AAT, UKST, VLT, the SAAO 1.9m and the MSSSO 2.3m telescope have established the identity of these faint sources down to magnitude R~23 for H-alpha (4.5 x 10^-17 ergs cm^2 s^-1 Ang). Confirmed emission-line stars have been assigned an underlying spectral classification through cross-correlation against 131 absorption line template spectra covering the range O1 to F8. We confirm 111 previously identified emission line stars and 64 previously known variable stars with spectral types hotter ...

  16. SPATIALLY RESOLVED H{alpha} MAPS AND SIZES OF 57 STRONGLY STAR-FORMING GALAXIES AT z {approx} 1 FROM 3D-HST: EVIDENCE FOR RAPID INSIDE-OUT ASSEMBLY OF DISK GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Erica June; Van Dokkum, Pieter G.; Skelton, Rosalind E.; Bezanson, Rachel; Lundgren, Britt [Astronomy Department, Yale University, New Haven, CT 06511 (United States); Brammer, Gabriel [European Southern Observatory, Alonson de Cordova 3107, Casilla 19001, Vitacura, Santiago (Chile); Foerster Schreiber, Natascha [Max-Planck-Institut fuer extraterrestrische Physik, Giessenbachstrasse, D-85748 Garching (Germany); Franx, Marijn; Fumagalli, Mattia; Patel, Shannon; Labbe, Ivo [Leiden Observatory, Leiden University, Leiden (Netherlands); Rix, Hans-Walter; Da Cunha, Elisabete; Schmidt, Kasper B. [Max Planck Institute for Astronomy (MPIA), Koenigstuhl 17, 69117 Heidelberg (Germany); Kriek, Mariska [Department of Astronomy, University of California, Berkeley, CA 94720 (United States); Quadri, Ryan [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)

    2012-03-10

    We investigate the buildup of galaxies at z {approx} 1 using maps of H{alpha} and stellar continuum emission for a sample of 57 galaxies with rest-frame H{alpha} equivalent widths >100 A in the 3D-HST grism survey. We find that the H{alpha} emission broadly follows the rest-frame R-band light but that it is typically somewhat more extended and clumpy. We quantify the spatial distribution with the half-light radius. The median H{alpha} effective radius r{sub e} (H{alpha}) is 4.2 {+-} 0.1 kpc but the sizes span a large range, from compact objects with r{sub e} (H{alpha}) {approx} 1.0 kpc to extended disks with r{sub e} (H{alpha}) {approx} 15 kpc. Comparing H{alpha} sizes to continuum sizes, we find H{alpha})/r{sub e} (R) > =1.3 {+-} 0.1 for the full sample. That is, star formation, as traced by H{alpha}, typically occurs out to larger radii than the rest-frame R-band stellar continuum; galaxies are growing their radii and building up from the inside out. This effect appears to be somewhat more pronounced for the largest galaxies. Using the measured H{alpha} sizes, we derive star formation rate surface densities, {Sigma}{sub SFR}. We find that {Sigma}{sub SFR} ranges from {approx}0.05 M{sub Sun} yr{sup -1} kpc{sup -2} for the largest galaxies to {approx}5 M{sub Sun} yr{sup -1} kpc{sup -2} for the smallest galaxies, implying a large range in physical conditions in rapidly star-forming z {approx} 1 galaxies. Finally, we infer that all galaxies in the sample have very high gas mass fractions and stellar mass doubling times <500 Myr. Although other explanations are also possible, a straightforward interpretation is that we are simultaneously witnessing the rapid formation of compact bulges and large disks at z {approx} 1.

  17. H-alpha mapping of DDO 53

    International Nuclear Information System (INIS)

    Deep CCD narrow-band H-alpha imaging of the dwarf irregular galaxy DDO 53 has revealed a total of 18 H II regions. Positions, H-alpha luminosities, and sizes of these objects are tabulated. The luminosity function agrees, within its limited statistical significance, with the normal relation found for irregular galaxies. The size distribution has an exponential shape, as for other galaxies, with a size scale of 59 + or - 6 pc. 14 refs

  18. An H-alpha velocity study of S252

    Science.gov (United States)

    Fountain, W. F.; Gary, G. A.; Odell, C. R.

    1983-01-01

    The H II region S252 (NGC 2175) was studied by means of H-alpha radial velocities and line widths. The velocity structure appears to be dominated by the western ionization front, abutting a dense neutral cloud which is a CO source, and by symmetry abut the ionizing star. This data, together with other studies of CO, H167-alpha, and the H II radio continuum, allow construction of a model of S252. The H II model is basically a double blister formed by a luminous hot star being located between two orthogonal, elongated neutral clouds.

  19. Temporal evolution of mottles observed in H_alpha

    CERN Document Server

    Bostanci, Z F; Erdogan, Nurol Al

    2007-01-01

    In April 2002, H_alpha observations of the solar chromosphere with high spatial and spectral resolution were obtained with the Gottingen Fabry-Perot Spectrometer mounted in the Vacuum Tower Telescope (VTT) at the Observatorio del Teide/Tenerife. In this work, we analyze a short time sequence of a quiet region with chains of mottles. Some physical parameters of dark mottles are determined by using Beckers' cloud model which takes the source function, the Doppler width, and the velocity to be constant within the cloud along the line of sight. Here, we present the results of our study.

  20. High-redshift Ly alpha emitters with a large equivalent width: Properties of i-dropout galaxies with an NB921-band depression in the Subaru Deep Field

    CERN Document Server

    Nagao, T; Maiolino, R; Marconi, A; Kashikawa, N; Ajiki, M; Hattori, T; Ly, C; Malkan, M A; Motohara, K; Ohta, K; Sasaki, S S; Shioya, Y; Taniguchi, Y; Nagao, Tohru; Murayama, Takashi; Maiolino, Roberto; Marconi, Alessandro; Kashikawa, Nobunari; Ajiki, Masaru; Hattori, Takashi; Ly, Chun; Malkan, Matthew A.; Motohara, Kentaro; Ohta, Kouji; Sasaki, Shunji S.; Shioya, Yasuhiro; Taniguchi, Yoshiaki

    2007-01-01

    We report new follow-up spectroscopy of i-dropout galaxies with an NB921-band depression found in the Subaru Deep Field. The NB921-depressed i-dropout selection method is expected to select galaxies with large equivalent width Ly alpha emission over a wide redshift range, 6.0equivalent widths are 153A and 114A, which are lower limits on the intrinsic equivalent widths. Through our spectroscopic observations (including previous ones) of NB921-depressed i-dropout galaxies, we identified 5 galaxies in total with a rest-frame equivalent width larger than 100A at 6.0equivalent width, in a wider redshift range than usual narrow-band excess techniques. B...

  1. The stars with H-alpha missing

    Science.gov (United States)

    Downes, Ronald A.

    1987-05-01

    During the course of a survey for ultraviolet-excess objects, a group of objects were found that spectroscopically resemble the subdwarf B stars, except for variable strength H-alpha absorption. The H-alpha line can have the nominal strength predicted from the other Balmer lines, or it can be completely absent. Observations reveal significant changes in the H-alpha profile on both a night-to-night and month-to-month basis. IUE observations of three stars reveal few features in the ultraviolet region and, when combined with optical data, allow a rough determination of photospheric temperatures. A binary model is proposed for these systems, and the ramifications of the objects found here and in the Palomar-Green survey are discussed.

  2. Halpha Equivalent Widths from the 3D-HST survey: evolution with redshift and dependence on stellar mass

    CERN Document Server

    Fumagalli, Mattia; Franx, Marijn; Brammer, Gabriel; van Dokkum, Pieter; da Cunha, Elisabete; Kriek, Mariska; Lundgren, Britt; Momcheva, Ivelina; Rix, Hans-Walter; Schmidt, Kasper B; Skelton, Rosalind E; Whitaker, Katherine E; Labbe, Ivo; Nelson, Erica

    2012-01-01

    We investigate the evolution of the Halpha equivalent width, EW(Halpha), with redshift and its dependence on stellar mass, taking advantage of the first data from the 3D-HST survey, a large spectroscopic Treasury program with the Hubble Space Telescope WFC3. Combining our Halpha measurements of 854 galaxies at 0.8

  3. THE FORMATION OF THE H{alpha} LINE IN THE SOLAR CHROMOSPHERE

    Energy Technology Data Exchange (ETDEWEB)

    Leenaarts, J.; Carlsson, M.; Rouppe van der Voort, L., E-mail: jorritl@astro.uio.no, E-mail: mats.carlsson@astro.uio.no, E-mail: rouppe@astro.uio.no [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, N-0315 Oslo (Norway)

    2012-04-20

    We use state-of-the-art radiation-MHD simulations and three-dimensional (3D) non-LTE radiative transfer computations to investigate H{alpha} line formation in the solar chromosphere and apply the results of this investigation to develop the potential of H{alpha} as a diagnostic of the chromosphere. We show that one can accurately model H{alpha} line formation assuming statistical equilibrium and complete frequency redistribution provided the computation of the model atmosphere included non-equilibrium ionization of hydrogen and the Ly{alpha} and Ly{beta} line profiles are described by Doppler profiles. We find that 3D radiative transfer is essential in modeling hydrogen lines due to the low photon destruction probability in H{alpha}. The H{alpha} opacity in the upper chromosphere is mainly sensitive to the mass density and only weakly sensitive to the temperature. We find that the H{alpha} line-core intensity is correlated with the average formation height: The larger the average formation height is, the lower the intensity will be. The line-core width is a measure of the gas temperature in the line-forming region. The fibril-like dark structures seen in H{alpha} line-core images computed from our model atmosphere are tracing magnetic field lines. These structures are caused by field-aligned ridges of enhanced chromospheric mass density that raise their average formation height, and therefore make them appear dark against their deeper-formed surroundings. We compare with observations, and find that the simulated line-core widths are very similar to the observed ones, without the need for additional microturbulence.

  4. H$\\alpha$ Star Formation Rates of $z$ > 1 Galaxy Clusters in the IRAC Shallow Cluster Survey

    CERN Document Server

    Zeimann, Gregory; Brodwin, Mark; Gonzalez, Anthony H; Mancone, Conor; Snyder, Gregory F; Stern, Daniel; Eisenhardt, Peter; Dey, Arjun; Moustakas, John

    2013-01-01

    We present Hubble Space Telescope near-IR spectroscopy for 18 galaxy clusters at 1.0 < $z$ < 1.5 in the IRAC Shallow Cluster Survey. We use Wide Field Camera 3 grism data to spectroscopically identify H$\\alpha$ emitters in both the cores of galaxy clusters as well as in field galaxies. We find a large cluster-to-cluster scatter in the star formation rates within a projected radius of 500 kpc, and many of our clusters (~60%) have significant levels of star formation within a projected radius of 200 kpc. A stacking analysis reveals that dust reddening in these star-forming galaxies is positively correlated with stellar mass and may be higher in the field than the cluster at a fixed stellar mass. This may indicate a lower amount of gas in star-forming cluster galaxies than in the field population. Also, H$\\alpha$ equivalent widths of star-forming galaxies in the cluster environment are still suppressed below the level of the field. This suppression is most significant for lower mass galaxies (log M$_{*}$ &...

  5. First results of an H-alpha based search of classical Be stars in the Perseus Arm and beyond

    CERN Document Server

    Raddi, R; Fabregat, J; Steeghs, D; Wright, N J; Sale, S E; Farnhill, H J; Barlow, M J; Greimel, R; Sabin, L; Corradi, R M L; Drake, J J

    2013-01-01

    We investigate a region of the Galactic plane, between 120 <= l <= 140 and -1 <= b <= +4, and uncover a population of moderately reddened (E(B-V) \\sim 1) classical Be stars within and beyond the Perseus and Outer Arms. 370 candidate emission line stars (13 <= r <= 16) selected from the INT Photometric H-alpha Survey of the Northern Galactic plane (IPHAS) have been followed up spectroscopically. A subset of these, 67 stars with properties consistent with those of classical Be stars, have been observed at sufficient spectral resolution (Delta_lambda \\sim 2 - 4 Angstrom) at blue wavelengths to narrow down their spectral types. We determine these to a precision estimated to be +/- 1 sub-type and then we measure reddenings via SED fitting with reference to appropriate model atmospheres. Corrections for contribution to colour excess from circumstellar discs are made using an established scaling to H-alpha emission equivalent width. Spectroscopic parallaxes are obtained after luminosity class has b...

  6. High-redshift Ly alpha emitters with a large equivalent width: Properties of i-dropout galaxies with an NB921-band depression in the Subaru Deep Field

    OpenAIRE

    Nagao, Tohru; Murayama, Takashi; Maiolino, Roberto; Marconi, Alessandro; Kashikawa, Nobunari; Ajiki, Masaru; Hattori, Takashi; Ly, Chun; Malkan, Matthew A.; Motohara, Kentaro; Ohta, Kouji; Sasaki, Shunji S.; Shioya, Yasuhiro; Taniguchi, Yoshiaki

    2007-01-01

    We report new follow-up spectroscopy of i-dropout galaxies with an NB921-band depression found in the Subaru Deep Field. The NB921-depressed i-dropout selection method is expected to select galaxies with large equivalent width Ly alpha emission over a wide redshift range, 6.0

  7. Unresolved H-Alpha Enhancements at High Galactic Latitude in the WHAM Sky Survey Maps

    CERN Document Server

    Reynolds, R J; Madsen, G J; Haffner, L M

    2004-01-01

    We have identified 85 regions of enhanced H-Alpha emission at |b| > 10 degrees subtending approximately 1 degree or less on the Wisconsin H-Alpha Mapper (WHAM) sky survey. These high latitude ``WHAM point sources'' have H-Alpha fluxes of 10^{-11} to 10^{-9} erg cm^-2 s^-1, radial velocities within about 70 km/s of the LSR, and line widths that range from less than 20 km/s to about 80 km/s (FWHM). Twenty nine of these enhancements are not identified with either cataloged nebulae or hot stars and appear to have kinematic properties that differ from those observed for planetary nebulae. Another 14 enhancements are near hot evolved low mass stars that had no previously reported detections of associated nebulosity. The remainder of the enhancements are cataloged planetary nebulae and small, high latitude H II regions surrounding massive O and early B stars.

  8. ON THE ORIGINS OF THE DIFFUSE H{alpha} EMISSION: IONIZED GAS OR DUST-SCATTERED H{alpha} HALOS?

    Energy Technology Data Exchange (ETDEWEB)

    Seon, Kwang-Il [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of); Witt, Adolf N., E-mail: kiseon@kasi.re.kr [Ritter Astrophysical Research Center, University of Toledo, Toledo, OH 43606 (United States)

    2012-10-20

    It is known that the diffuse H{alpha} emission outside of bright H II regions not only are very extended, but also can occur in distinct patches or filaments far from H II regions, and the line ratios of [S II] {lambda}6716/H{alpha} and [N II] {lambda}6583/H{alpha} observed far from bright H II regions are generally higher than those in the H II regions. These observations have been regarded as evidence against the dust-scattering origin of the diffuse H{alpha} emission (including other optical lines), and the effect of dust scattering has been neglected in studies on the diffuse H{alpha} emission. In this paper, we reexamine the arguments against dust scattering and find that the dust-scattering origin of the diffuse H{alpha} emission cannot be ruled out. As opposed to the previous contention, the expected dust-scattered H{alpha} halos surrounding H II regions are, in fact, in good agreement with the observed H{alpha} morphology. We calculate an extensive set of photoionization models by varying elemental abundances, ionizing stellar types, and clumpiness of the interstellar medium (ISM) and find that the observed line ratios of [S II]/H{alpha}, [N II]/H{alpha}, and He I {lambda}5876/H{alpha} in the diffuse ISM accord well with the dust-scattered halos around H II regions, which are photoionized by late O- and/or early B-type stars. We also demonstrate that the H{alpha} absorption feature in the underlying continuum from the dust-scattered starlight ({sup d}iffuse galactic light{sup )} and unresolved stars is able to substantially increase the [S II]/H{alpha} and [N II]/H{alpha} line ratios in the diffuse ISM.

  9. Quantitative Fourier transform infrared diagnostics of the gas-phase composition using the HITRAN database and the equivalent width of the spectral features.

    Science.gov (United States)

    Sepman, A V; den Blanken, R; Schepers, R; de Goey, L P H

    2009-11-01

    This paper presents a strategy for quantification of medium resolution Fourier transform infrared (FT-IR) spectra. The approach is based on a comparison of the values of the equivalent width of spectral features determined from the measured FT-IR spectra with those calculated from corresponding molecular spectra simulated using spectroscopic parameters tabulated in the HITRAN database. Although the equivalent-width method is routinely applied in many high-resolution experiments, its potential is often ignored when the spectral resolution of the measurements is bigger than the width of the studied molecular transitions. Here with an eye on application of the method to the study of the biomass thermal decomposition products, we demonstrate the capability of the method for analysis of FT-IR spectra with moderate resolution. The method is validated for a number of molecules (NH3, CO, CH4, C2H2, C2H4, and NO) that are important products of biomass thermal decomposition. Namely, known amounts of gases were placed in a sample cell and their concentrations were determined using the method for different FT-IR settings. The agreement between the concentration values determined using the present method and those found in the sample cell was generally better than 10%. The paper also shows examples of application of the developed methodology for the analysis of FT-IR spectra from biomass pyrolysis. PMID:19891829

  10. Flux calibration of the AAO/UKST SuperCOSMOS H-alpha Survey

    OpenAIRE

    Frew, David J.; Bojicic, Ivan S.; Parker, Quentin A.; Pierce, Mark J.; Gunawardhana, M. L. P.; Reid, W. A.

    2013-01-01

    The AAO/UKST SuperCOSMOS H$\\alpha$ Survey (SHS) was, when completed in 2003, a powerful addition to extant wide-field surveys. The combination of areal coverage, spatial resolution and sensitivity in a narrow imaging band, still marks it out today as an excellent resource for the astronomical community. The 233 separate fields are available online in digital form, with each field covering 25 square degrees. The SHS has been the motivation for equivalent surveys in the north,...

  11. Kelvin--Helmholtz instability in solar H-alpha surges

    CERN Document Server

    Zhelyazkov, I; Chandra, R; Srivastava, A K; Mishonov, T

    2015-01-01

    We study the evolutionary conditions for Kelvin--Helmholtz (KH) instability in a H-alpha solar surge observed in NOAA AR 8227 on 1998 May 30. The jet with speeds in the range of 45--50 km/s, width of 7 Mm, and electron number density of 3.83 x 10^{10} cm^{-3} is assumed to be confined in a twisted magnetic flux tube embedded in a magnetic field of 7 G. The temperature of the plasma flow is of the order of 10^5 K while that of its environment is taken to be 2 x 10^6 K. The electron number density of surrounding magnetized plasma has a typical for the TR/lower corona region value of 2 x 10^{9} cm^{-3}. Under these conditions, the Alfven speed inside the jet is equal to 78.3 km/s. We model the surge as a moving magnetic flux tube for two magnetic field configurations: (i) a twisted tube surrounded by plasma with homogeneous background magnetic field, and (ii) a twisted tube which environment is plasma with also twisted magnetic field. The magnetic field twist in given region is characterized by the ratio of azim...

  12. On the origins of the diffuse H-alpha emission: Ionized gas or dust-scattered H-alpha halos?

    CERN Document Server

    Seon, Kwang-Il

    2012-01-01

    It is known that the diffuse H-alpha emission outside of bright H II regions not only are very extended, but also can occur in distinct patches or filaments far from H II regions, and the line ratios of [S II] 6716/H-alpha and [N II] 6583/H-alpha observed far from bright H II regions are generally higher than those in the H II regions. These observations have been regarded as evidence against the dust-scattering origin of the diffuse H-alpha emission (including other optical lines), and the effect of dust scattering has been neglected in studies on the diffuse H-alpha emission. In this paper, we reexamine the arguments against dust scattering and find that the dust-scattering origin of the diffuse H-alpha emission cannot be ruled out. As opposed to the previous contention, the expected dust- scattered H-alpha halos surrounding H II regions are, in fact, in good agreement with the observed H-alpha morphology. We calculate an extensive set of photoionization models by varying elemental abundances, ionizing stel...

  13. Sensitivity of H alpha profiles to rapid electron beam fluctuations

    International Nuclear Information System (INIS)

    In order to understand the temporal relationship between H alpha and hard x ray emission predicted by the nonthermal electron thick target model of impulsive-phase energy transport the time-dependent theoretical H alpha profiles were computed for the dynamic model atmospheres of Fisher, Canfield, and McClymont, which simulate the effects of an impulsively initiated power-law beam of electrons. On the basis of the physical analysis it was expected that a very rapid H alpha response to an instantaneous increase in the flux of a nonthermal deka-keV electron beam, as compared to the timescale associated with the propagation of these electrons over characteristic flare coronal loop spatial scales. It was concluded that observational efforts to test the thick target nonthermal electron model through detection of impulsive H alpha brightenings associated with impulsive hard x ray or microwave bursts should initially focus attention on the H alpha line center. Additional simultaneous blue-wing measurements will have substantial diagnostic potential

  14. H{alpha} ABSORPTION IN TRANSITING EXOPLANET ATMOSPHERES

    Energy Technology Data Exchange (ETDEWEB)

    Christie, Duncan; Arras, Phil; Li Zhiyun, E-mail: dac5zm@virginia.edu, E-mail: pla7y@virginia.edu, E-mail: zl4h@virginia.edu [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States)

    2013-08-01

    Absorption of stellar H{alpha} by the upper atmosphere of the planet HD 189733b has recently been detected by Jensen et al. Motivated by this observation, we have developed a model for atomic hydrogen in the n = 2 state and compared the resulting H{alpha} line profile to the observations. The model atmosphere is in hydrostatic balance, as well as thermal and photoionization equilibrium. Collisional and radiative transitions are included in the determination of the n = 2 state level population. We find that H{alpha} absorption is dominated by an optical depth {tau} {approx} 1 shell, composed of hydrogen in the metastable 2s state that is located below the hydrogen ionization layer. The number density of the 2s state within the shell is found to vary slowly with radius, while that of the 1s state falls rapidly. Thus while the Ly{alpha} absorption, for a certain wavelength, occurs inside a relatively well defined impact parameter, the contribution to H{alpha} absorption is roughly uniform over the entire atomic hydrogen layer. The model can approximately reproduce the observed Ly{alpha} and H{alpha} integrated transit depths for HD 189733b by using an ionization rate enhanced over that expected for the star by an order of magnitude. For HD 209458b, we are unable to explain the asymmetric H{alpha} line profile observed by Jensen et al., as the model produces a symmetric line profile with transit depth comparable to that of HD 189733b. In an appendix, we study the effect of the stellar Ly{alpha} absorption on the net cooling rate.

  15. H-alpha Spectral diversity of type II supernovae

    DEFF Research Database (Denmark)

    P. Gutiérrez, Claudia; P. Anderson, Joseph

    2014-01-01

    We present a spectroscopic analysis of the H-alpha profiles of hydrogen-rich type II supernovae. A total of 52 type II supernovae having well sampled optical light curves and spectral sequences were analyzed. Concentrating on the H-alpha P-Cygni profile we measure its velocity from the FWHM of emission and the ratio of absorption to emission (a/e) at a common epoch at the start of the recombination phase, and search for correlations between these spectral parameters and photometric properties of the V-band light curves. Testing the strength of various correlations we find that a/e appears to be the dominant spectral parameter in terms of describing the diversity in our measured supernova properties. It is found that supernovae with smaller a/e have higher H-alpha velocities, more rapidly declining light curves from maximum, during the plateau and radioactive tail phase, are brighter at maximum light and have shorter optically thick phase durations. We discuss possible explanations of these results in terms ofphysical properties of type II supernovae, speculating that the most likely parameters which influence the morphologies of H-alpha profiles are the mass and density profile of the hydrogen envelope, together with additional emission components due to circumstellar interaction.

  16. A Survey for H$\\alpha$ Pulsar Bow Shocks

    CERN Document Server

    Brownsberger, Sasha

    2014-01-01

    We report on a survey for H$\\alpha$ bow shock emission around nearby $\\gamma$-detected energetic pulsars. This survey adds three Balmer-dominated neutron star bow shocks to the six previously confirmed examples. In addition to the shock around {\\it Fermi} pulsar PSR J1741$-$2054, we now report H$\\alpha$ structures around two additional $\\gamma$-ray pulsars, PSR J2030+4415 and PSR J1509$-$5850. These are the first known examples of H$\\alpha$ nebulae with pre-ionization halos. With new measurements, we show that a simple analytic model can account for the angular size and flux of the bow shocks' apices. The latter, in particular, provides a new pulsar probe and indicates large moments of inertia and smaller distances than previously assumed, in several cases. In particular we show that the re-measured PSR J0437$-$4715 shock flux implies $I = (1.7\\pm 0.2) \\times 10^{45}/(f_{HI} {\\rm sin}i) {\\rm g\\,cm^2}$. We also derive a distance $d\\approx 0.72$kpc for the $\\gamma$-ray only pulsar PSR J2030+4415 and revised dis...

  17. An imaging survey of northern galactic H-alpha emmission with arcminute resolution

    Science.gov (United States)

    Dennison, B.; Simonetti, J. H.; Topasna, G. A.

    1998-04-01

    We present preliminary results from a high-resolution, high-sensitivity imaging survey of the northern galactic H-alpha emission. The survey is carried out using the Spectral Line Imaging Camera (SLIC) which incorporates a fast (f/1.2) lens attached to a cryogenic CCD in combination with a narrowband interference filter. The pixel size is 1.6 arcminutes and the diameter of each field is 10 degrees. The fast optics, narrow bandpass (1.7 nm) filter, and high quantum-efficiency, low-noise CCD yield a high brightness sensitivity to H-alpha emission on arcminute scales. This gives an equivalent sensitivity to emission measure structure below 1 pc cm^-6^. Some faint features detected include a supershell connected with the star forming region W4 extending 7 degrees above the galactic plane, and filaments possibly related to galactic loops II and III. In addition, we have carried out deep observations of fields in which anisotropies in the cosmic microwave background radiation have been detected. Our observations place stringent limits upon the contribution to the apparent microwave fluctuations from free-free emission in the galactic foreground.

  18. H-alpha response to geomagnetic disturbed activity at Arecibo.

    Science.gov (United States)

    Santos, Pedrina; Kerr, R.; Noto, J.; Brum, Christiano; Gonzalez, Sixto

    Configured with a spectral resolution of 0.0086 nm at 6563A, the low resolution Fabry-Perot Interferometer (FPI) installed at Arecibo Observatory sampled the geocoronal Balmer-alpha emission for sixty nights during new moon periods from September 2006 to September 2007. In this work two of these periods are analyzed according to the variability with the geomagnetic activity. With this purpose, the effect of the shadow height, local time and solar flux depen-dencies were found and isolated and only the possible variations due the geomagnetic activity were evaluated. The residuos of the relative H-alpha intensity and temperature are analyzed.

  19. A Detection Of H-alpha In An Exoplanetary Exosphere

    CERN Document Server

    Jensen, Adam G; Endl, Michael; Cochran, William D; Koesterke, Lars; Barman, Travis S

    2012-01-01

    We report on a search for H-alpha absorption in four exoplanets. Strong features at H-alpha are observed in the transmission spectra of both HD 189733b and HD 209458b. We attempt to characterize and remove the effects of stellar variability in HD 189733b, and along with an empirical Monte Carlo test the results imply a statistically significant transit-dependent feature of (-8.72+/-1.48)x10^-4 integrated over a 16 Angstrom band relative to the adjacent continuum. We interpret this as the first detection of this line in an exoplanetary atmosphere. A previous detection of Ly-alpha in HD 189733b's atmosphere allows us to calculate an excitation temperature for hydrogen, T_exc=2.6x10^4 K. This calculation depends significantly on certain simplifying assumptions. We explore these assumptions and argue that T_exc is very likely much greater than the radiative equilibrium temperature (the temperature the planet is assumed to be at based on stellar radiation and the planetary distance) of HD 189733b. A large T_exc im...

  20. Limits on the star formation rates of z > 2 damped Ly$\\alpha$ systems from H$\\alpha$ spectroscopy

    CERN Document Server

    Bunker, A J; Clements, D L; Williger, G M; Hewett, P C; Bunker, Andrew J.; Warren, Stephen J.; Williger, Gerard M.; Hewett, Paul C.

    1999-01-01

    We present the results of a long-slit K-band spectroscopic search for H-alpha emission from eight damped Ly-alpha absorbers (DLAs) at z>2 with the goal of measuring the star-formation rates in these systems. For each system we searched for compact sources of H-alpha emission within a solid angle 11x2.5arcsec^2 (44x10 kpc^2/h^2, for q_0=0.5, H_0=100 h km/s/Mpc). No H-alpha emission was detected above 3-sigma limits in the range (6.5 - 16)x1E-20 W/m^2, equivalent to star formation rates of (5.6 - 18) M_sun/yr/h^2, for a standard IMF, assuming the lines are spectrally unresolved (<650 km/s FWHM). We compare these results against the predictions of the models of Pei & Fall (1995) of the global history of star formation, under two different simplifying hypotheses: i.) the space density of DLAs at z=2.3 is equal to the space density of spiral galaxies today (implying DLA disks were larger in the past, the `large-disk' hypothesis); ii.) the sizes of DLAs at z=2.3 were the same as the gas sizes of spiral galax...

  1. Observational Tests to Detect Photometric Reverberation in H-alpha

    Science.gov (United States)

    Joner, Michael D.; Carroll, Carla

    2014-06-01

    We present photometric observations of several AGN that were secured with the 0.9-m telescope located at the West Mountain Observatory that is operated by Brigham Young University. The new observations use standard BVR filters along with several custom filters that are part of a red shifted H-alpha set. Light curves are presented for several of the targets along with a summary of the analysis made to detect lag times between the continuum and broad emission line flux as evidence for photometric reverberation. Plans are presented for future research that will continue along these lines.We thank the Department of Physics and Astronomy along with the College of Physical and Mathematical Sciences at Brigham Young University for continued support of the research work being done at the West Mountain Observatory.

  2. H-alpha Filaments and Feedback in NGC4696 at the centre of the Centaurus cluster

    Science.gov (United States)

    Fabian, Andrew

    2014-10-01

    One third of Brightest Cluster Galaxies (BCG) have strong opticalemission lines originating in an extensive filamentary nebula. Theprototype is the spectacular nebula around NGC1275 in the Perseuscluster which we are have imaged in H-alpha and [NII] with HST,spatially resolving the filamentary structure. Here we propose deepobservations of the nebula in NGC4696, the BCG in the Centaurus cluster.NGC4696, at approximately half the distance of NGC1275 is the nearestBCG nebula with molecular filaments, thus affording the highest linearspatial resolution in this type of source.These observations will test the magnetic support model for thefilaments by resolving and measuring the width of the filaments, andtest the particle heating model for the excitation of the filamentsthrough measurement of their surface brightness distribution andmorphology.The relation of the filaments to the dust lanes, and the complex FaradayRotation maps of this source will provide further diagnostics notavailable in NGC1275. The results will have a wide relevance to similarnebulae found around distant radio galaxies and young galaxies.

  3. Properties of the H-alpha-emitting Circumstellar Regions of Be Stars

    CERN Document Server

    Tycner, C; Hajian, A R; Armstrong, J T; Benson, J A; Gilbreath, G C; Hutter, D J; Pauls, T A; White, N M; Tycner, Christopher; Lester, John B.; Hajian, Arsen R.

    2005-01-01

    Long-baseline interferometric observations obtained with the Navy Prototype Optical Interferometer of the H-alpha-emitting envelopes of the Be stars eta Tauri and beta Canis Minoris are presented. For compatibility with the previously published interferometric results in the literature of other Be stars, circularly symmetric and elliptical Gaussian models were fitted to the calibrated H-alpha observations. The models are sufficient in characterizing the angular distribution of the H-alpha-emitting circumstellar material associated with these Be stars. To study the correlations between the various model parameters and the stellar properties, the model parameters for eta Tau and beta CMi were combined with data for other Be stars from the literature. After accounting for the different distances to the sources and stellar continuum flux levels, it was possible to study the relationship between the net H-alpha emission and the physical extent of the H-alpha-emitting circumstellar region. A clear dependence of the...

  4. A Ly{alpha} EMITTER WITH AN EXTREMELY LARGE REST-FRAME EQUIVALENT WIDTH OF {approx}900 A AT z = 6.5: A CANDIDATE POPULATION III-DOMINATED GALAXY?

    Energy Technology Data Exchange (ETDEWEB)

    Kashikawa, Nobunari; Hayashi, Masao; Iye, Masanori [Optical and Infrared Astronomy Division, National Astronomical Observatory, Mitaka, Tokyo 181-8588 (Japan); Nagao, Tohru; Ota, Kazuaki [Department of Astronomy, Graduate School of Science, Kyoto University, Kyoto 606-8502 (Japan); Toshikawa, Jun; Ishizaki, Yoshifumi; Shibuya, Takatoshi [Department of Astronomy, School of Science, Graduate University for Advanced Studies, Mitaka, Tokyo 181-8588 (Japan); Egami, Eiichi; Jiang, Linhua [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Ly, Chun [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Malkan, Matthew A. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095-1547 (United States); Matsuda, Yuichi [Radio Astronomy Division, National Astronomical Observatory, Mitaka, Tokyo 181-8588 (Japan); Shimasaku, Kazuhiro [Department of Astronomy, University of Tokyo, Hongo, Tokyo 113-0033 (Japan); Taniguchi, Yoshiaki; Shioya, Yasuhiro, E-mail: n.kashikawa@nao.ac.jp [Research Center for Space and Cosmic Evolution, Ehime University, Bunkyo-cho, Matsuyama 790-8577 (Japan)

    2012-12-20

    We have identified a very interesting Ly{alpha} emitter (LAE), whose Ly{alpha} emission line has an extremely large observed equivalent width of EW{sub 0} = 436{sup +422}{sub -{sub 149}} A, which corresponds to an extraordinarily large intrinsic rest-frame equivalent width of EW{sup int}{sub 0} = 872{sup +844}{sub -{sub 298}} A after the average intergalactic absorption correction. The object was spectroscopically confirmed to be a real LAE by its apparent asymmetric Ly{alpha} line profile detected at z = 6.538. The continuum emission of the object was definitely detected in our deep z'-band image; thus, its EW{sub 0} was reliably determined. Follow-up deep near-infrared spectroscopy revealed emission lines of neither He II {lambda}1640 as an apparent signature of Population III (Pop III) nor C IV {lambda}1549 as proof of an active nucleus. No detection of the short-lived He II {lambda}1640 line is not necessarily inconsistent with the interpretation that the underlying stellar population of the object is dominated by Pop III. We found that the observed extremely large EW{sub 0} of the Ly{alpha} emission and the upper limit on the EW{sub 0} of the He II {lambda}1640 emission can be explained by population synthesis models favoring a very young age less than 2-4 Myr and massive metal-poor (Z < 10{sup -5}) or even metal-free stars. The observed large EW{sub 0} of Ly{alpha} is insufficiently explained by Population I/II synthesis models with Z {>=} 10{sup -3}. However, we cannot conclusively rule out the possibility that this object is composed of a normal stellar population with a clumpy dust distribution, which could enhance the Ly{alpha} EW{sub 0}, though its significance is still unclear.

  5. The clustering of H-alpha emitters at z=2.23 from HiZELS

    CERN Document Server

    Geach, J E; Hickox, R C; Wake, D A; Smail, Ian; Best, P N; Baugh, C M; Stott, J P

    2012-01-01

    (abridged) We present a clustering analysis of 370 high-confidence H-alpha emitters (HAEs) at z=2.23. The HAEs are detected in the Hi-Z Emission Line Survey (HiZELS), a large-area blank field 2.121um narrowband survey using the United Kingdom Infrared Telescope (UKIRT) Wide Field Camera (WFCAM). Averaging the two-point correlation function of HAEs in two ~1 degree scale fields (United Kingdom Infrared Deep Sky Survey/Ultra Deep Survey [UDS] and Cosmological Evolution Survey [COSMOS] fields) we find a clustering amplitude equivalent to a correlation length of r_0=3.7+/-0.3 Mpc/h for galaxies with star formation rates of >7 M_sun/yr. The data are well-fitted by the expected correlation function of Cold Dark Matter, scaled by a bias factor: omega_HAE=b^2 omega_DM where b=2.4^{+0.1}_{-0.2}. The corresponding 'characteristic' mass for the halos hosting HAEs is log(M_h/[M_sun/h])=11.7+/-0.1. Comparing to the latest semi-analytic GALFORM predictions for the evolution of HAEs in a LCDM cosmology, we find broad agreem...

  6. The H-alpha Luminosity Function and Star-Formation Rate Volume Density at z=0.8 from the NEWFIRM H-alpha Survey

    CERN Document Server

    Ly, Chun; Dale, Daniel A; Momcheva, Ivelina; Salim, Samir; Staudaher, Shawn; Moore, Carolynn A; Finn, Rose

    2010-01-01

    [Abridged] We present new measurements of the H-alpha luminosity function (LF) and SFR volume density for galaxies at z~0.8. Our analysis is based on 1.18$\\mu$m narrowband data from the NEWFIRM H-alpha Survey, a comprehensive program designed to capture deep samples of intermediate redshift emission-line galaxies using narrowband imaging in the near-infrared. The combination of depth ($\\approx1.9\\times10^{-17}$ erg s$^{-1}$ cm$^{-2}$ in H-alpha at 3$\\sigma$) and areal coverage (0.82 deg$^2$) complements other recent H-alpha studies at similar redshifts, and enables us to minimize the impact of cosmic variance and place robust constraints on the shape of the LF. The present sample contains 818 NB118 excess objects, 394 of which are selected as H-alpha emitters. Optical spectroscopy has been obtained for 62% of the NB118 excess objects. Empirical optical broadband color classification is used to sort the remainder of the sample. A comparison of the LFs constructed for the four individual fields reveals signific...

  7. The clustering and evolution of H-alpha emitters at z~1 from HiZELS

    CERN Document Server

    Sobral, David; Geach, James E; Smail, Ian; Cirasuolo, Michele; Garn, Timothy; Dalton, Gavin B; Kurk, Jaron

    2009-01-01

    The clustering properties of a well-defined sample of 734 H-alpha emitters at z=0.84 obtained as part of the Hi-z Emission Line Survey (HiZELS) are investigated. The spatial correlation function is very well-described by (r/r_0)^-1.8, with r_0=2.7+-0.3Mpc/h. The correlation length r_0 increases strongly with H-alpha luminosity, L_H-alpha, from r_0~2Mpc/h for the most quiescent galaxies (star-formation rates of ~4M_sun/yr), up to r_0>5Mpc/h for the brightest galaxies in H-alpha. The correlation length also increases with increasing rest-frame K-band luminosity (M_K), but the r_0-L_H-alpha correlation maintains its full statistical significance at fixed M_K. At z=0.84, star-forming galaxies classified as irregulars or mergers are much more clustered than discs and non-mergers, but once the samples are matched in L_H-alpha and M_K, the differences vanish, implying that the clustering is independent of morphological type at z~1. The typical H-alpha emitters found at z=0.84 reside in dark-matter haloes of ~10^12M_...

  8. Observatons of NGC 3077 Galaxy in Narrow Band [SII] and H_alpha Filters

    CERN Document Server

    Andjelic, M; Arbutina, B; Ilic, D; Urosevic, D

    2011-01-01

    We present observations of the HI tidal arm near dwarf galaxy NGC 3077 (member of the M81 galaxy group) in narrow band [SII] and H_alpha filters. Observations were carried out in March 2011 with the 2m RCC telescope at NAO Rozhen, Bulgaria. Our search for possible supernova remnant candidates (identified as sources with enhanced [SII] emission relative to their H_alpha emission) in this region yielded no sources of this kind. Nevertheless, we found a number of objects with significant H_alpha emission that probably represent uncatalogued, low brightness HII regions.

  9. Constraining Disk Parameters of Be Stars using Narrowband H-alpha Interferometry with the NPOI

    CERN Document Server

    Tycner, C; Benson, J A; Gilbreath, G C; Hajian, A R; Hutter, D J; Jones, C E; Pauls, T A; White, N M; Zavala, R T

    2006-01-01

    Interferometric observations of two well-known Be stars, gamma Cas and phi Per, were collected and analyzed to determine the spatial characteristics of their circumstellar regions. The observations were obtained using the Navy Prototype Optical Interferometer equipped with custom-made narrowband filters. The filters isolate the H-alpha emission line from the nearby continuum radiation, which results in an increased contrast between the interferometric signature due to the H-alpha-emitting circumstellar region and the central star. Because the narrowband filters do not significantly attenuate the continuum radiation at wavelengths 50 nm or more away from the line, the interferometric signal in the H-alpha channel is calibrated with respect to the continuum channels. The observations used in this study represent the highest spatial resolution measurements of the H-alpha-emitting regions of Be stars obtained to date. These observations allow us to demonstrate for the first time that the intensity distribution in...

  10. The Wyoming Survey for H-alpha. III. H-alpha Luminosity Functions at z ~ 0.16, 0.24, 0.32, and 0.40

    CERN Document Server

    Dale, Daniel A; Cohen, Seth A; Cook, David O; Johnson, L Clifton; Kattner, ShiAnne M; Moore, Carolynn A; Schuster, Micah D; Staudaher, Shawn M

    2010-01-01

    The Wyoming Survey for H-alpha, or WySH, is a large-area, ground-based imaging survey for H-alpha-emitting galaxies at redshifts of z ~ 0.16, 0.24, 0.32, and 0.40. The survey spans up to four square degrees in a set of fields of low Galactic cirrus emission, using twin narrowband filters at each epoch for improved stellar continuum subtraction. H-alpha luminosity functions are presented for each Delta(z) ~ 0.02 epoch based on a total of nearly 1200 galaxies. These data clearly show an evolution with lookback time in the volume-averaged cosmic star formation rate. Integrals of Schechter fits to the incompleteness- and extinction-corrected H-alpha luminosity functions indicate star formation rates per co-moving volume of 0.010, 0.013, 0.020, 0.022 h_70 M_sun yr^{-1} Mpc^{-3} at z ~ 0.16, 0.24, 0.32, and 0.40, respectively. Statistical and systematic measurement uncertainties combined are on the order of 25% while the effects of cosmic variance are at the 20% level. The bulk of this evolution is driven by change...

  11. A Correlation between Balmer H-$\\alpha$ Emission and Infrared Cirrus

    CERN Document Server

    McCullough, P R

    1997-01-01

    A 13x13 degree image of Balmer H-alpha emission at galactic latitude -65 degrees is presented. Sensitivity is limited in part by confusion: the peak-to-valley anisotropy of the H-alpha surface brightness is 0.2 Rayleighs on angular scales of 0.1 to 1.0 degrees. The morphology of the H-alpha emission is similar to that of the 100 um emission previously observed by the Infrared Astronomical Satellite (IRAS). A point-by-point comparison of the two shows a marginally detected (3-sigma) positive correlation, rho = +0.14 (+-0.04). The slope of the correlated components of the 100 um and H-alpha emissions is 1.26 (+0.45) (-0.32) MJy/sr/R. Using parameters from the literature, we predict that emission from dust and ionized gas at high latitudes produces 3 times more H-alpha emission per unit 100 um emission than does backscattering of H-alpha emission from Galactic H II regions by dust at high latitude. Observations of this type may allow us to distinguish between Galactic foreground and cosmic background for both th...

  12. An H-alpha survey of the rich cluster A1689

    CERN Document Server

    Balogh, M; Smail, I; Bower, R G; Glazebrook, K; Balogh, Michael; Couch, Warrick J.; Smail, Ian; Bower, Richard G.; Glazebrook, Karl

    2002-01-01

    (Abridged) We present results of an H-alpha survey in the rich cluster A1689 at z=0.18, using the LDSS++ spectrograph on the AAT. We obtained spectra covering redshifted H-alpha for 522 galaxies brighter than I=22.5, covering a field of 8.7'X8.7'. We detect H-alpha emission in 46 of these galaxies; accounting for selection effects due to sampling and cluster membership, we determine that 24% of cluster members brighter than M_R=-16.5+5log(h) are detected with H-alpha flux greater than 4h^{-2}X 10^{38} ergs/s. This corresponds to a limiting star formation rate of 0.008 h^{-2} Msun/yr, assuming 1 magnitude of dust extinction. From a Hubble Space Telescope mosaic covering 7.5' X 10.0', we determine morphologies for 199 galaxies brighter than I=21, and find that 20% of the cluster members are of type Sa or later. More than 90% of cluster spirals show H-alpha emission, compared with less than 10% of E and S0 galaxies. The cluster H-alpha luminosity function has a low normalisation relative to the z~0.2 field, by ~...

  13. The Spatially Resolved H\\alpha-Emitting Wind Structure of P Cygni

    CERN Document Server

    Balan, Aurelian; Zavala, R T; Benson, J A; Hutter, D J; Templeton, M

    2010-01-01

    High spatial resolution observations of the H\\alpha-emitting wind structure associated with the Luminous Blue Variable star P Cygni were obtained with the Navy Prototype Optical Interferometer (NPOI). These observations represent the most comprehensive interferometric data set on P Cyg to date. We demonstrate how the apparent size of the H\\alpha-emitting region of the wind structure of P Cyg compares between the 2005, 2007 and 2008 observing seasons and how this relates to the H\\alpha line spectroscopy. Using the data sets from 2005, 2007 and 2008 observing seasons, we fit a circularly symmetric Gaussian model to the interferometric signature from the H\\alpha-emitting wind structure of P Cyg. Based on our results we conclude that the radial extent of the H\\alpha-emitting wind structure around P Cyg is stable at the 10% level. We also show how the radial distribution of the H\\alpha flux from the wind structure deviates from a Gaussian shape, whereas a two-component Gaussian model is sufficient to fully describ...

  14. Integral field spectroscopy of H-alpha emission in cooling flow cluster cores: disturbing the molecular gas reservoir

    CERN Document Server

    Wilman, R J; Swinbank, A M

    2006-01-01

    We present optical integral field spectroscopy of the H-alpha-luminous (>1E42 erg/s) central cluster galaxies in the cores of the cooling flows A1664, A1835, A2204 and Zw8193. From the [NII]+H-alpha complex we derive 2-D views of the distribution and kinematics of the emission line gas, and further diagnostics from the [SII] and [OI] lines. The H-alpha emission shows a variety of disturbed morphologies with velocity gradients and splittings of several hundred km/s on scales of 20 kpc or more. Despite the small sample size, there are some generic features. The most disturbed H-alpha emission appears to be associated with secondary galaxies within 10-20 kpc (projected) of the central galaxy and close in velocity to the H-alpha. The global H-alpha kinematics match those of CO(1-0) emission in single-dish data. The [NII]/H-alpha, [SII]/H-alpha and [OI]/H-alpha ratios vary little with position, local H-alpha surface brightness or between clusters. We propose that the H-alpha and CO emission arise in molecular clou...

  15. Galaxy And Mass Assembly (GAMA): Bivariate functions of H$\\alpha$ star forming galaxies

    CERN Document Server

    Gunawardhana, M L P; Taylor, E N; Bland-Hawthorn, J; Norberg, P; Baldry, I K; Loveday, J; Owers, M S; Wilkins, S M; Colless, M; Brown, M J I; Driver, S P; Alpaslan, M; Brough, S; Cluver, M; Croom, S; Kelvin, L; Lara-López, M A; Liske, J; López-Sánchez, A R; Robotham, A S G

    2014-01-01

    We present bivariate luminosity and stellar mass functions of H$\\alpha$ star forming galaxies drawn from the Galaxy And Mass Assembly (GAMA) survey. While optically deep spectroscopic observations of GAMA over a wide sky area enable the detection of a large number of $0.001<{SFR}_{H\\alpha}$ (M$_{\\odot}$ yr$^{-1}$)$<100$ galaxies, the requirement for an H$\\alpha$ detection in targets selected from an $r$-band magnitude limited survey leads to an incompleteness due to missing optically faint star forming galaxies. Using $z<0.1$ bivariate distributions as a reference we model the higher-$z$ distributions, thereby approximating a correction for the missing optically faint star forming galaxies to the local SFR and stellar mass densities. Furthermore, we obtain the $r$-band LFs and stellar mass functions of H$\\alpha$ star forming galaxies from the bivariate LFs. As our sample is selected on the basis of detected H$\\alpha$ emission, a direct tracer of on-going star formation, this sample represents a true ...

  16. H-$\\alpha$ Imaging of Early-type(Sa-Sab) Spiral Galaxies, 1

    CERN Document Server

    Hameed, S A; Hameed, Salman; Devereux, Nick

    1999-01-01

    H-alpha and continuum images are presented for 27 nearby early-type(Sa-Sab) spiral galaxies. Contrary to popular perception, the images reveal copious massive star formation in some of these galaxies. A determination of the H-alpha morphology and a measure of the H-alpha luminosity suggests that early-type spirals can be classified into two broad categories based on the luminosity of largest HII region in the disk. The first category includes galaxies for which the individual HII regions have L(H-alpha) 10^(39) erg/s. All category 2 galaxies show either prominent dust lanes or other morphological peculiarities such as tidal tails which suggests that the anomalously luminous HII regions in category 2 galaxies may have formed as a result of a recent interaction. The observations, which are part of an on-going H-alpha survey, reveal early-type spirals to be a heterogeneous class of galaxies that are evolving in the current epoch. We have also identified some systematic differences between the classifications of...

  17. The sensitivity of H alpha profiles to rapid electron beam fluctuations

    Science.gov (United States)

    Canfield, Richard C.; Gayley, Kenneth G.

    In order to understand the temporal relationship between H alpha and hard X-ray emission predicted by the nonthermal electron thick target model of impulsive-phase energy transport the time-dependent theoretical H alpha profiles were computed for the dynamic model atmospheres of Fisher, Canfield, and McClymont, which simulate the effects of an impulsively initiated power-law beam of electrons. On the basis of the physical analysis it was expected that a very rapid H alpha response to an instantaneous increase in the flux of a nonthermal deka-keV electron beam, as compared to the timescale associated with the propagation of these electrons over characteristic flare coronal loop spatial scales. It was concluded that observational efforts to test the thick target nonthermal electron model through detection of impulsive H alpha brightenings associated with impulsive hard X-ray or microwave bursts should initially focus attention on the H alpha line center. Additional simultaneous blue-wing measurements will have substantial diagnostic potential.

  18. Localization of HXR and H-alpha impulsive brightenings during the solar flares

    Science.gov (United States)

    Radziszewski, Krzysztof; Rudawy, Pawel

    We investigated localization of hard X-ray radiation (HXR) and H-alpha impulsive brightenings recorded during solar flares. Using high cadence observations we analysed temporal relation-ships and mutually changes of localizations as well as intensity variations of the non-thermal HXR and thermal H-alpha sources. The visual data (so-called spectra-images) were collected with the Multi-Channel Subtractive Double Pass (MSDP) spectrograph and Solar Eclipse Coro-nal Imaging System (SECIS) in Bialkow Observatory (University of Wroclaw, Poland) in H-alpha line with high time resolution (up to 50 ms). The HXR images were reconstructed from Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) observations, using the PIXON method. Ultraviolet observations from Transition Region and Coronal Explorer (TRACE) satellite were used for localizations of anchors of hot coronal loops within the solar flare regions. We found good conformity of HXR non-thermal sources with H-alpha emission, confirming our earlier results showing very fast radiative response of chromosphere in H-alpha range during impulsive phase of solar flares.

  19. Nebular Attenuation in H\\alpha-selected Star-forming Galaxies at z=0.8 from the NewH\\alpha\\ Survey

    CERN Document Server

    Momcheva, Ivelina; Ly, Chun; Salim, Samir; Dale, Daniel A; Ouchi, Masami; Finn, Rose; Ono, Yoshiaki

    2012-01-01

    We present measurements of the dust attenuation of H\\alpha-selected emission-line galaxies at z=0.8 from the NewH\\alpha\\ narrowband survey. The analysis is based on deep follow-up spectroscopy with Magellan/IMACS, which captures the strong rest-frame optical emission lines from [OII] \\lambda 3727 to [OIII] \\lambda 5007. The spectroscopic sample used in this analysis consists of 341 confirmed H\\alpha\\ emitters. We place constraints on the AGN fraction using diagnostics which can be applied at intermediate redshift. We find that at least 5% of the objects in our spectroscopic sample can be classified as AGN and 2% are composite, i.e. powered by a combination of star-formation and AGN activity. We measure the dust attenuation for individual objects from the ratios of the higher order Balmer lines. The H\\beta\\ and H\\gamma\\ pair of lines is detected with S/N>5 in 55 individual objects and the H\\beta\\ and H\\delta\\ pair is detected in 50 individual objects. We also create stacked spectra to probe the attenuation in ...

  20. A Dual Narrowband Survey for H\\alpha\\ Emitters at z=2.2: Demonstration of the Technique and Constraints on the H\\alpha\\ Luminosity Function

    CERN Document Server

    Lee, Janice C; Spitler, L; Labbe, I; Salim, S; Persson, S E; Ouchi, M; Dale, D; Monson, A; Murphy, D

    2012-01-01

    We present first results from a narrowband imaging program for intermediate redshift emission-line galaxies using the newly commissioned FourStar infrared camera at the 6.5m Magellan telescope. To enable prompt identification of H\\alpha\\ emitters, a pair of custom 1% filters, which sample low-airglow atmospheric windows at 1.19 \\mu m and 2.10 \\mu m, is used to detect both H\\alpha\\ and [OII]\\lambda 3727 emission from the same redshift volume at z=2.2. Initial observations are taken over a 130 arcmin^2 area in the CANDELS-COSMOS field. The exquisite image quality resulting from the combination of the instrument, telescope, and standard site conditions (~0.55" FWHM) allows the 1.19 \\mu m and 2.10 \\mu m data to probe 3\\sigma\\ emission-line depths down to 1.0e-17 erg/s/cm^2 and 1.2e-17 erg/s/cm^2 respectively, in less than 10 hours of integration time in each narrowband. For H\\alpha\\ at z=0.8 and z=2.2, these fluxes correspond to observed star formation rates of ~0.3 and ~4 Msun/yr respectively. We find 122 source...

  1. A study of excess H-alpha emission in chromospherically active M dwarf

    International Nuclear Information System (INIS)

    Spectroscopic observations from three observatories are combined to study the properties of the excess H-alpha emission which characterizes the most chromospherically active subset of the M dwarf stars, known as the dMe stars. It is demonstrated that the excess H-alpha luminosity from these stars is a monotonically decreasing function of their (R-I) color, and evidence is presented which suggests that the product of the mean surface brightness and the mean filling factor of the emissive regions is essentially constant with color. Another significant result of the study is a linear correlation between the excess luminosity in H-alpha and the coronal X-ray luminosity. 39 refs

  2. Far-infrared characteristics of K dwarfs with H-alpha emission

    International Nuclear Information System (INIS)

    A sample of K dwarfs with H-alpha emission have counterparts in the IRAS Point Source Catalog. They show two types of infrared spectral behavior, either net decline of emergent flux density from 0.55 micron to at least 12 microns, approximately like normal K dwarfs without H-alpha emission, or net rise in this spectral range, as though with radiation from cool circumstellar matter. Behavior type is not well associated with H-alpha emission strength. Declining spectra are detectable with IRAS to about 30 pc, but rising spectra are not found in this volume so they must be less abundant. Stars with rising spectra may be associated with nebulosity, but one of them, TW Hya, is an exception to the later dependence. 25 references

  3. The Discovery of a Giant H-alpha Filament in NGC 7213

    CERN Document Server

    Hameed, S A; Young, L; Devereux, N; Hameed, Salman; Blank, David; Young, Lisa; Devereux, Nick

    2000-01-01

    The nearby Seyfert galaxy NGC 7213 has been imaged in H-alpha and HI with the CTIO 1.5 m telescope and with the Australia Telescope Compact Array (ATCA), respectively. Optically NGC 7213 looks undisturbed and relatively featureless but the continuum-subtracted H-alpha image shows a 19 kpc long filament located approximately 18.6 kpc from the nucleus. The H-alpha filament could be neutral gas photo-ionized by the active nucleus, as has been suggested for the Seyfert galaxy NGC 5252, or shock-ionized by a jet interacting with the surrounding HI, as has been suggested for the radio galaxy PKS 2240-41. The HI map reveals NGC 7213 to be a highly disturbed system suggesting a past merging event.

  4. The Properties of H{\\alpha} Emission-Line Galaxies at z = 2.24

    OpenAIRE

    An, F. X.; Zheng, X. Z.; Wang, W. -h; Huang, J. -s; Kong, X.; Wang, J. -x; Fang, G. W.; Zhu, F.; Gu, Q. -s; Wu, H.; Hao, L.; Xia, X. -y

    2014-01-01

    Using deep narrow-band $H_2S1$ and $K_{s}$-band imaging data obtained with CFHT/WIRCam, we identify a sample of 56 H$\\alpha$ emission-line galaxies (ELGs) at $z=2.24$ with the 5$\\sigma$ depths of $H_2S1=22.8$ and $K_{s}=24.8$ (AB) over 383 arcmin$^{2}$ area in the ECDFS. A detailed analysis is carried out with existing multi-wavelength data in this field. Three of the 56 H$\\alpha$ ELGs are detected in Chandra 4 Ms X-ray observation and two of them are classified as AGNs. The...

  5. H-alpha kinematics of a z ~ 1 disc galaxy from near-IR integral field spectroscopy

    OpenAIRE

    Smith, J. K.; Bunker, A. J.; Vogt, N. P.; Abraham, R. G.; Aragon-salamanca, A.; Bower, R. G.; Parry, I. R.; Sharp, R. G.; Swinbank, A. M.

    2004-01-01

    In this letter we present the first 3D spectroscopic study of H-alpha emission in a z ~ 1 field galaxy with an integral field unit. Using the CIRPASS spectrograph on Gemini-South we map the spatial and velocity distribution of H-alpha emission in the z=0.819 galaxy CFRS 22.1313. We detect two H-alpha emitting regions with a velocity separation of 220+/-10 km/s. Combining the 2D map of H-alpha emission with HST F814W imaging, we determine a lower limit of 180+/-20 km/s for th...

  6. A catalogue of integrated H-alpha fluxes for 1,258 Galactic planetary nebulae

    CERN Document Server

    Frew, David J; Parker, Q A

    2012-01-01

    We present a catalogue of new integrated H-alpha fluxes for 1258 Galactic planetary nebulae (PNe), with the majority, totalling 1234, measured from the Southern H-Alpha Sky Survey Atlas (SHASSA) and/or the Virginia Tech Spectral-line Survey (VTSS). Aperture photometry on the continuum-subtracted digital images was performed to extract H-alpha + [NII] fluxes in the case of SHASSA, and H-alpha fluxes from VTSS. The [NII] contribution was then deconvolved from the SHASSA flux using spectrophotometric data taken from the literature or derived by us. Comparison with previous work shows that the flux scale presented here has no significant zero-point error. Our catalogue is the largest compilation of homogeneously derived PN fluxes in any waveband yet measured, and will be an important legacy and fresh benchmark for the community. Amongst its many applications, it can be used to determine statistical distances for these PNe, determine new absolute magnitudes for delineating the faint end of the PN luminosity functi...

  7. The Star-Formation Law in the Ultraviolet and H-alpha

    Science.gov (United States)

    Meurer, G. R.; Thilker, D.; Bianchi, L.; Ferguson, A.; Madore, B.; Gil de Paz, A.; Hameed, S.; GALEX Science Team

    2004-12-01

    Much of what we know about star formation in galaxies comes from the observation of H-alpha, the most easily accessible high mass star formation tracer, which indicates the presence of ionizing O stars (M > ˜20 M? ). The launch of GALEX provides ready access to high quality observations of another important, more direct high mass star formation tracer - the far ultraviolet (FUV). The FUV is sensitive to photospheric emission from both O and B stars (M > ˜8 M? ) and thus to the full mass range of stars with the largest impact on the ISM through ionization, dissociation of H2, stellar winds, and supernovae explosions. Comparison of GALEX FUV and terrestial H-alpha observations of nearby disk galaxies show that typically (but not always) the UV emission extends considerably further than the H-alpha. While the H-alpha distributions often show a marked edge, as originally noted by Kennicutt (1989), the UV distributions do not (Thilker et al., ApJL, in press; Bianchi et al., ApJL in press). This result has enormous implications for galactic evolution, particularly our understanding of the star formation law, the initial mass function, modes of star formation, the stability of extended HI disk galaxies, and star formation surveys. We examine these implications and explore possible explanations for the different distributions of these important star formation tracers.

  8. A long-term study of H(alpha) line variations in FK Comae Berenices

    Science.gov (United States)

    Welty, Alan D.; Ramsey, Lawrence W.; Iyengar, Mrinal; Nations, Harold L.; Buzasi, Derek L.

    1993-01-01

    We present observations of H(alpha) V/R ratio variations in FK Comae Berencies obtained during several observing seasons from 1981 to 1992. The raw H(alpha) emission profile is always observed to be double peaked due to the stellar-absorption component. During the most years the V/R ratio varies regularly with the period of the photometric light curve. The V/R periodicity is most obvious when time spans no longer than several stellar rotations are considered. We propose that the bulk of the emission component of the H(alpha) line arises in corotating circumstellar material that may be similar to that of a quiescent solar prominence. The lifetime of these structures appears to be on the order of weeks. A weak contribution from a circumstellar disk is evident and chromospheric emission may also be present. The appearance or disappearance of circumstellar structures over periods longer than a few weeks, or the total absence of such structures, blurs the more regular variations in H(alpha) seen over short time scales. Other more stochastic activity, such as flares, also clearly occurs. Phase shifts of the V/R ratio from year to year rule out the hypothesis that mass tranfer in a close binary system is responsible for the V/R variations.

  9. H$\\alpha$ and Free-Free Emission from the WIM

    CERN Document Server

    Dong, Ruobing

    2010-01-01

    Recent observations have found the ratio of H$\\alpha$ to free-free radio continuum to be surprisingly high in the diffuse ionized ISM (the so-called WIM), corresponding to an electron temperature of only $\\sim$3000~K. Such low temperatures were unexpected in gas that was presumed to be photoionized. We consider a 3-component model for the observed diffuse emission, consisting of a mix of (1) photoionized gas, (2) gas that is recombining and cooling, and (3) cool H~I gas. This model can successfully reproduce the observed intensities of free-free continuum, H$\\alpha$, and collisionally-excited lines such as [\\ion{N}{2}]6583. To reproduce the low observed value of free-free to H$\\alpha$, the PAH abundance in the photoionized regions must be lowered by a factor $\\sim$3, and $\\sim$15\\% of the diffuse H$\\alpha$ must be reflected from dust grains, as suggested by \\citet{Wood+Reynolds_1999}.

  10. The Properties of H{\\alpha} Emission-Line Galaxies at $z$ = 2.24

    CERN Document Server

    An, F X; Wang, W -H; Huang, J -S; Kong, X; Wang, J -X; Fang, G W; Zhu, F; Gu, Q -S; Wu, H; Hao, L; Xia, X -Y

    2014-01-01

    Using deep narrow-band $H_2S1$ and $K_{s}$-band imaging data obtained with CFHT/WIRCam, we identify a sample of 56 H$\\alpha$ emission-line galaxies (ELGs) at $z=2.24$ with the 5$\\sigma$ depths of $H_2S1=22.8$ and $K_{s}=24.8$ (AB) over 383 arcmin$^{2}$ area in the ECDFS. A detailed analysis is carried out with existing multi-wavelength data in this field. Three of the 56 H$\\alpha$ ELGs are detected in Chandra 4 Ms X-ray observation and two of them are classified as AGNs. The rest-frame UV and optical morphologies revealed by HST/ACS and WFC3 deep images show that nearly half of the H$\\alpha$ ELGs are either merging systems or with a close companion, indicating that the merging/interacting processes play a key role in regulating star formation at cosmic epoch z=2-3; About 14% are too faint to be resolved in the rest-frame UV morphology due to high dust extinction. We estimate dust extinction form SEDs. We find that dust extinction is generally correlated with H$\\alpha$ luminosity and stellar mass (SM). Our res...

  11. H-alpha Spectroscopy of Galaxies at z>2 Kinematics and Star Formation

    CERN Document Server

    Erb, D K; Steidel, C C; Pettini, M; Adelberger, K L; Hunt, M P; Moorwood, A F M; Cuby, J G; Erb, Dawn K.; Shapley, Alice E.; Steidel, Charles C.; Pettini, Max; Adelberger, Kurt L.; Hunt, Matthew P.; Moorwood, Alan F.M.; Cuby, Jean-Gabriel

    2003-01-01

    We present near-infrared spectroscopy of H-alpha emission lines in a sample of 16 star-forming galaxies at redshifts 2.04e10 M_sun. One-dimensional velocity dispersions for the 16 galaxies range from ~50 to ~260 km/s, and in cases where we have both virial masses implied by the velocity dispersions and dynamical masses derived from the spatially extended emission lines, they are in rough agreement. We compare our kinematic results to similar measurements made at z~3, and find that both the observed rotational velocities and velocity dispersions tend to be larger at z~2 than at z~3. We find a mean SFR_H-alpha of 16 M_sun/yr and an average SFR_H-alpha/SFR_UV ratio of 2.4, without correcting for extinction. We see moderate evidence for an inverse correlation between the UV continuum luminosity and the ratio SFR_H-alpha/SFR_UV, such as might be observed if the UV-faint galaxies suffered greater extinction. We discuss the effects of dust and star formation history on the SFRs, and conclude that extinction is the m...

  12. The Virginia Tech H-alpha and [SII] Imaging Survey of the Northern Sky

    Science.gov (United States)

    Dennison, B.; Simonetti, J. H.; Topasna, G. A.

    1999-12-01

    We are conducting a northern hemisphere survey of the Galactic H-alpha and [SII] emission. Our instrument, the Virginia Tech Spectral Line Imaging Camera (SLIC), utilizes a fast objective lens (f/1.2), a cryogenically-cooled TK 512x512 CCD, and narrow-band interference filters. The result is 10-degree diameter images with 1.6-arcminute pixel sizes. Observations in H-alpha are nearly complete over a region within 30 degrees of the Galactic plane between longitudes of 0 and 240 degrees, plus selected regions farther from the plane. [SII] observations have already covered a major fraction of the sky observed in H-alpha. Observations of the entire northern hemisphere in both H-alpha and [SII] are in progress. Processed images are made available to the community on the Web (http://www.phys.vt.edu/halpha). Our survey, with its 1.6 arcminute resolution, is complementary to Reynold's and collaborators' WHAM (Wisconsin H? Mapper) survey which collects detailed spectral information with approximately 1 degree angular resolution. This research is supported by NSF grants AST-9319670 and AST-9800476 and a grant from the Horton Foundation to Virginia Tech.

  13. Using the Tremaine-Weinberg method to measure pattern speeds from H\\alpha velocity maps

    CERN Document Server

    Beckman, John; Piñol, Nuria; Hernandez, Olivier; Carignan, Claude; Pérez, Isabel

    2008-01-01

    The Tremaine-Weinberg method is a well-known model independent technique for measuring density wave pattern speeds in spiral galaxies. Here we show how it can be applied to the data cubes (maps of surface brightness and velocity) obtained in H-alpha emission using a Fabry-Perot spectrometer. One of the main difficulties, the discontinuity of the H-alpha emission, is resolved using the neighbouring stellar continuum delivered by the data cube. We argue from symmetry that the motions not associated with the density wave should cancel. We show that our pattern speeds are reasonable by computing corotation radii, and comparing them to measured bar lengths. Simulations including star forming gas also add credibility to our results. Nevertheless it will be necessary to compare them with results using the spectra of the stellar components to quantify any systematic deviations from valid pattern speed values.

  14. Comparing H-alpha, UV, and Far-IR Star Formation Rates of Galaxies at 2

    Science.gov (United States)

    Shivaei, Irene; Reddy, N.

    2013-01-01

    We use a unique sample of 262 star-forming galaxies selected during the epoch of peak cosmic star formation to infer star-formation rates and dust reddening, and to investigate the validity of the local star-formation calibrations at high redshift. The sample contains galaxies at redshifts 2.08population model fit to the optical and IRAC data, we are able to infer an H-alpha flux for each galaxy. These H-alpha fluxes are combined with UV continuum and Spitzer/MIPS 24 micron measurements in order to examine the bolometric star-formation rates and dust attenuation. We discuss the comparison of these three complementary star-formation rate indicators in the context of the star-formation histories of the galaxies, and the implications for inferring star-formation rates and reddening at high redshift.

  15. H-alpha scans of the intergalactic H I cloud in Leo

    International Nuclear Information System (INIS)

    Scans of H-alpha were obtained for two fields within the large, intergalactic H I cloud in Leo. The data provide a conservative upper limit of 1.7 x 10 to the -7th ergs/sq cm/s/sr on the H-alpha surface brightness of the cloud. This limit corresponds to an emission measure of less than 2 cm exp -6 pc for gas at a temperature of 10,000 K and implies an ionized hydrogen mass of less than 9 x 10 to the 9th f exp 1/2 solar mass within the cloud, where f is the filling fraction of the gas. This intensity may have important implications for possible sources of the ionization. 17 references

  16. H{alpha} DOTS: A CATALOG OF FAINT EMISSION-LINE OBJECTS DISCOVERED IN NARROWBAND IMAGES

    Energy Technology Data Exchange (ETDEWEB)

    Kellar, Jessica A.; Wegner, Gary [Department of Physics and Astronomy, 6127 Wilder Laboratory, Dartmouth College, Hanover, NH 03755 (United States); Salzer, John J.; Williams, Anna [Department of Astronomy, Indiana University, 727 East Third Street, Bloomington, IN 47405 (United States); Gronwall, Caryl, E-mail: jessica.a.kellar@dartmouth.edu, E-mail: gaw@northstar.dartmouth.edu, E-mail: slaz@astro.indiana.edu, E-mail: caryl@astro.psu.edu, E-mail: williams@astro.wisc.edu [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States)

    2012-06-15

    During a wide-field narrowband H{alpha} imaging survey, we noted the presence of numerous isolated emission-line point sources in the data. These objects could represent ultra-low-luminosity galaxies at low-redshift (detection via H{alpha}), isolated extragalactic H II regions associated with the galaxy targeted by the original observation, or background galaxies or QSOs where strong emission lines (most often [O III] {lambda}5007) redshift into our narrowband filter. We have carried out a systematic search for these 'H{alpha} dots' in over 200 15 Multiplication-Sign 15 arcmin fields. To date we have cataloged 61 candidate emission-line sources in roughly 11.7 deg{sup 2}. The sample has a median R magnitude of 19.5, and detects objects as faint as R = 22.6. Follow-up spectroscopy reveals that {approx}85% of the candidates are bona fide emission-line objects, with roughly 60% of the real sources being lower-redshift objects (detection via H{alpha}) and 40% being higher-redshift objects detected via [O III] emission or some other emission line. Here we present the results of our initial survey and follow-up spectroscopy. We use our sample to study the properties (including star-formation rates and metal abundances) of low-luminosity star-forming galaxies in the nearby universe and of low-metallicity star-forming galaxies at z Almost-Equal-To 0.33.

  17. Solar Flare Detection With SWIFT and Real-time GONG H-alpha Images

    Science.gov (United States)

    Henney, Carl John; MacKenzie, D.; Hill, F.; Mills, B.; Pietrzak, J.

    2011-05-01

    The Air Force Weather Agency (AFWA) has begun the process of upgrading the Solar Observing Optical Network (SOON) with an Improved-SOON (ISOON). During the interim period, AFWA is supporting the addition and operation of a solar H-alpha (Hydrogen-alpha, 656.3 nm) full-disk image network utilizing the light feed from the National Solar Observatory's existing GONG (Global Oscillation Network Group) instruments. The H-alpha instruments at the GONG sites have been in operation collectively since the beginning of 2011, providing one to three H-alpha images per minute. Cross-site comparison and calibration of flare detection has begun using an image analysis tool called SWIFT (SWFL/ISOON Flare-cast Tool). SWIFT is a unique and versatile software package, designed originally for ISOON data, that has been attuned to ingest and display GONG H-alpha images in real-time. The SWIFT software allows a user to detect and analyze optical flares from solar active regions. The SWIFT software is in the process of being beta-tested at AFWA in collaboration with the Space Weather Center of Excellence's SWFL (Space Weather Forecasting Laboratory) to better forecast space weather events. Solar flares are of great interest to the Air Force Research Laboratory's Space Vehicles Directorate because they can trigger energetic particle events or coronal mass ejection events that impact the Earth's magnetosphere creating geomagnetic storms. Such events can result in satellite charging damage, increased satellite drag, power grid disruption, navigation system anomalies, and communication fadeouts. An overview of SWIFT, along with preliminary flare detection comparisons between GONG sites and the SOON flare reports, will be presented.

  18. Small-scale H{\\alpha} Jets in the Solar Chromosphere

    CERN Document Server

    Kuridze, D; Jess, D B; Shelyag, S; Christian, D J; Keenan, F P; Balasubramaniam, K S

    2011-01-01

    High temporal and spatial resolution observations from the Rapid Oscillations in the Solar Atmosphere (ROSA) multiwavelength imager on the Dunn Solar Telescope are used to study the velocities of small-scale H{\\alpha} jets in an emerging solar active region. The dataset comprises of simultaneous imaging in the H{\\alpha} core, Ca II K, and G band, together with photo- spheric line-of-sight magnetograms. Time-distance techniques are employed to determine projected plane-of-sky velocities. The H{\\alpha} images are highly dynamic in nature, with estimated jet velocities as high as 45 km s^{-1}. These jets are one-directional, with their origin seemingly linked to underlying Ca II K brightenings and G-band magnetic bright points. It is suggested that the siphon flow model of cool coronal loops is suitable for the interpretation of our observations. The jets are associated with small-scale explosive events, and may provide a mass outflow from the photosphere to the corona.

  19. The star formation properties of disk galaxies H $\\alpha$ imaging of galaxies in the Coma supercluster

    CERN Document Server

    Gavazzi, G; Carrasco, L; Boselli, A; Contursi, A

    1998-01-01

    We present integrated H alpha measurements obtained from imaging observations of 98 late-type galaxies, primarily selected in the Coma supercluster. These data, combined with H alpha photometry from the literature, include a magnitude selected sample of spiral (Sa to Irr) galaxies belonging to the "Great Wall" complete up to mp=15.4, thus composed of galaxies brighter than Mp=-18.8 (H0=100 km Mpc^-1 s^-1). The frequency distribution of the H alpha E.W., determined for the first time from an optically complete sample, is approximately gaussian peaking at E.W. ~25 A. We find that, at the present limiting luminosity, the star formation properties of spiral+Irr galaxies members of the Coma and A1367 clusters do not differ significantly from those of the isolated ones belonging to the Great Wall. The present analysis confirms the well known increase of the current massive star formation rate (SFR) with Hubble type. Moreover perhaps a more fundamental anticorrelation exists between the SFR and the mass of disk gala...

  20. H$\\alpha$ Emission From Active Equal-mass, Wide M Dwarf Binaries

    CERN Document Server

    Gunning, Heather C; Davenport, James R A; Dhital, Saurav; Hawley, Suzanne L; West, Andrew A

    2014-01-01

    We identify a sample of near-equal mass wide binary M dwarf systems from the SLoWPoKES catalog of common proper-motion binaries and obtain follow-up observations of their chromospheric activity as measured by the H$\\alpha$ emission line. We present optical spectra for both components of 48 candidate M dwarf binaries, confirming their mid-M spectral types. Of those 48 coeval pairs, we find eight with H$\\alpha$ emission from both components, three with weak emission in one component and no emission in the other, and 37 with two inactive components. We find that of the eleven pairs with at least one active component, only three follow the net trend of decreasing activity strength $L_{\\rm H\\alpha}/L_{\\rm bol}$ with later spectral type. The difference in quiescent activity strength between the A and B components is larger than what would be expected based on the small differences in color (mass). For five binaries with two active components, we present 47 hours of time-resolved spectroscopy, observed on the ARC 3....

  1. Observations of H-alpha and microwave brightening caused by a distant solar flare

    Science.gov (United States)

    Kundu, M. R.; Bobrowsky, M.; Rust, D. M.

    1983-01-01

    Synthesized maps with integration times of 10 and 30 sec, based on the observation of three subflares at 6 cm and H-alpha 6563 A, indicate that most of the 6 cm burst emission originated in 10-15 arcsec features coincident with, or adjacent to, H-alpha flare kernels. During the onset of one of the subflares, 6 cm emission was discovered in a loop stretching over 100,000 km from the primary flare site in association with H-alpha flare-like brightness at the remote footpoint of the loop. Assuming a primary flare site origin for the energy of the distant brightening, about 4 x 10 to the 24th ergs/sec propagated along the connecting magnetic loop at a velocity of more than 6000 km/sec. It is suggested that the energy may have been carried by electrons originating in the high energy tail of the electron thermal velocity distribution, escaping from the primary flare site.

  2. The H-alpha surface brightness - radius relation: a robust statistical distance indicator for planetary nebulae

    CERN Document Server

    Frew, David J; Bojicic, I S

    2015-01-01

    Measuring the distances to Galactic planetary nebulae (PNe) has been an intractable problem for many decades. We have now established a robust optical statistical distance indicator, the H-alpha surface brightness -radius or S-r relation, which addresses this problem. We developed this relation from a critically evaluated sample of primary calibrating PNe. The robust nature of the method results from our revised calibrating distances with significantly reduced systematic uncertainties, and the recent availability of high-quality data, including updated nebular diameters and integrated H-alpha fluxes. The S-r technique is simple in its application, requiring only an angular size, an integrated H-alpha flux, and the reddening to the PN. From these quantities, an intrinsic radius is calculated, which when combined with the angular size, yields the distance directly. Furthermore, we have found that optically thick PNe tend to populate the upper bound of the trend, while optically-thin PNe fall along the lower bou...

  3. Spatially Resolved Ultraviolet, H-alpha, Infrared, and Radio Star Formation in M81

    CERN Document Server

    Gordon, K D; Appleton, P N; Bendo, G J; Calzetti, D; Dale, D A; Draine, B T; Engelbracht, C W; Frayer, D T; Helou, G; Hines, D C; Hinz, J L; Kelly, D M; Kennicutt, R C; Misselt, K A; Morrison, J E; Murphy, E J; Muzerolle, J; Pérez-González, P G; Regan, M W; Rieke, G H; Smith, J D T; Stansberry, J A; Stolovy, S R; Storrie-Lombardi, L J; Su, K Y L; Thornley, M D; Walter, F; Young, E T

    2004-01-01

    We present Multiband Imaging Photometer for Spitzer (MIPS) observations of M81 at 24, 70, and 160 micron. The grand design nature of M81 is clearly seen, showing two well resolved spiral arms containing numerous bright star forming regions. The MIPS images reveal a significant amount of cold dust associated with the spiral arms. We investigate the variation of the ultraviolet (UV), H-alpha, and infrared (IR) luminosities and star formation rate (SFR) indicators across the face of M81 using the MIPS images and archival UV and H-alpha images. For regions in M81, we find that UV and H-alpha SFRs (uncorrected for dust attenuation) are always lower than the IR SFR. The cause of this behavior is dust attenuation and/or using SFR calibrations appropriate for entire galaxies, not regions in galaxies. The characteristics of the dust attenuation for the regions indicate the dust grains and/or geometry are different from those in starburst galaxies. The behavior of the infrared-radio correlation in M81 is seen to vary f...

  4. H-alpha Distance Constraints for High-Velocity Clouds in the Galactic Halo

    CERN Document Server

    Bland-Hawthorn, J

    2001-01-01

    We present some developments in determining H-alpha distances to high-velocity clouds (HVCs) in the Galactic halo. Until recently, it was difficult to assess the nature and origin of HVCs because so little was known about them. But now several HVCs have reliable distance bounds derived from the stellar absorption technique, and more than a dozen have abundance measurements. In addition, twenty or more HVCs have been detected in H-alpha (and a few in optical forbidden lines). Over the past five years, we have been developing a model of the halo radiation field which includes contributions from the stellar disk, the stellar bulge, the hot corona, and the Magellanic Clouds. In certain instances, the H-alpha flux from an opaque HI cloud can be used to derive a crude distance constraint to the cloud. For a UV escape fraction of f_esc ~ 6% perpendicular to the disk (f_esc ~ 1-2% when averaged over solid angle), the HVCs appear to be broadly consistent with the spiral arm model. We caution that a larger database wit...

  5. Mapping High-velocity H-alpha and Lyman-alpha Emission from Supernova 1987A

    CERN Document Server

    France, Kevin; Fransson, Claes; Larsson, Josefin; Frank, Kari A; Burrows, David N; Challis, Peter; Kirshner, Robert P; Chevalier, Roger A; Garnavich, Peter; Heng, Kevin; Lawrence, Stephen S; Lundqvist, Peter; Smith, Nathan; Sonneborn, George

    2015-01-01

    We present new {\\it Hubble Space Telescope} images of high-velocity H-$\\alpha$ and Lyman-$\\alpha$ emission in the outer debris of SN~1987A. The H-$\\alpha$ images are dominated by emission from hydrogen atoms crossing the reverse shock. For the first time we observe emission from the reverse shock surface well above and below the equatorial ring, suggesting a bipolar or conical structure perpendicular to the ring plane. Using the H$\\alpha$ imaging, we measure the mass flux of hydrogen atoms crossing the reverse shock front, in the velocity intervals ($-$7,500~$<$~$V_{obs}$~$<$~$-$2,800 km s$^{-1}$) and (1,000~$<$~$V_{obs}$~$<$~7,500 km s$^{-1}$), $\\dot{M_{H}}$ = 1.2~$\\times$~10$^{-3}$ M$_{\\odot}$ yr$^{-1}$. We also present the first Lyman-$\\alpha$ imaging of the whole remnant and new $Chandra$ X-ray observations. Comparing the spatial distribution of the Lyman-$\\alpha$ and X-ray emission, we observe that the majority of the high-velocity Lyman-$\\alpha$ emission originates interior to the equatorial...

  6. Herschel reveals the obscured star formation in HiZELS H\\alpha\\ emitters at z=1.47

    CERN Document Server

    Ibar, E; Best, P N; Ivison, R J; Smail, I; Arumugam, V; Berta, S; Béthermin, M; Bock, J; Cava, A; Conley, A; Farrah, D; Floc'h, E Le; Lutz, D; Magdis, G; Magnelli, B; Ikarashi, S; Kohno, K; Marsden, G; Oliver, S J; Page, M J; Pozzi, F; Riguccini, L; Schulz, B; Seymour, N; Smith, A J; Symeonidis, M; Wang, L; Wardlow, J; Zemcov, M

    2013-01-01

    We describe the far-infrared (FIR; rest-frame 8--1000\\mu m) properties of a sample of 443 H\\alpha-selected star-forming galaxies in the COSMOS and UDS fields detected by the HiZELS imaging survey. Sources are identified using narrow-band filters in combination with broad-band photometry to uniformly select H\\alpha\\ (and [OII] if available) emitters in a narrow redshift slice at z = 1.47+/-0.02. We use a stacking approach in Spitzer, Herschel (from PEP and HerMES surveys) and AzTEC images to describe their typical FIR properties. We find that HiZELS galaxies with observed H\\alpha\\ luminosities of ~ 10^{8.1-9.1} Lo have bolometric FIR luminosities of typical LIRGs, L_FIR ~ 10^{11.48+/-0.05} Lo. Combining the H\\alpha\\ and FIR luminosities, we derive median SFR = 32+/-5 Mo/yr and H\\alpha\\ extinctions of A(H\\alpha) = 1.0+/-0.2 mag. Perhaps surprisingly, little difference is seen in typical HiZELS extinction levels compared to local star-forming galaxies. We confirm previous empirical stellar mass (M*) to A(H\\alpha...

  7. Optical Observations of M81 Galaxy Group in Narrow Band [SII] and H_alpha Filters: Holmberg IX

    CERN Document Server

    Arbutina, B; Stavrev, K; Urosevic, D; Vukotic, B; Onic, D; 10.2298/SAJ0979087A

    2009-01-01

    We present observations of the nearby tidal dwarf galaxy Holmberg IX in M81 galaxy group in narrow band [SII] and H$\\alpha$ filters, carried out in March and November 2008 with the 2m RCC telescope at NAO Rozhen, Bulgaria. Our search for resident supernova remnants (identified as sources with enhanced [SII] emission relative to their H$\\alpha$ emission) in this galaxy yielded no sources of this kind, besides M&H 10-11 or HoIX X-1. Nevertheless, we found a number of objects with significant H$\\alpha$ emission that probably represent uncatalogued HII regions.

  8. Optical Observations of M81 Galaxy Group in Narrow Band [SII] and H_alpha Filters: Holmberg IX

    Directory of Open Access Journals (Sweden)

    Arbutina, B.

    2009-12-01

    Full Text Available We present observations of the nearby tidal dwarf galaxy Holmberg IX in M81 galaxy group in narrow band [SII] and H$alpha$ filters, carried out in March and November 2008 with the 2m RCC telescope at NAO Rozhen, Bulgaria. Our search for resident supernova remnants (identified as sources with enhanced [SII] emission relative to their H$alpha$ emission in this galaxy yielded no sources of this kind, besides M&H 10-11 or HoIX X-1. Nevertheless, we found a number of objects with significant H$alpha$ emission that probably represent uncatalogued HII regions.

  9. H-alpha tail, intracluster HII regions and star-formation: ESO137-001 in Abell 3627

    OpenAIRE

    Sun, M.; Donahue, M.; Voit, G. M.

    2007-01-01

    We present the discovery of a 40 kpc H-alpha tail and at least 29 emission-line objects downstream of a star-forming galaxy ESO 137-001 in the rich, nearby cluster A3627. The galaxy is known to possess a dramatic 70 kpc X-ray tail. The detected H-alpha tail coincides positionally with the X-ray tail. The H-alpha emission in the galaxy is sharply truncated on the front and the sides near the nucleus, indicating significant ram pressure stripping. ESO 137-001 is thus the first...

  10. LkH-alpha 101 - the stellar wind, the surrounding nebula, and an associated radio star cluster

    International Nuclear Information System (INIS)

    Radio observations of LkH-alpha 101 have been taken to determine the characteristics of the stellar wind from the central star as well as to image the surrounding nebulosity. They also revealed the presence of a high concentration of weak compact radio sources in the neighborhood of LkH-alpha 101, four of which have optical stellar counterparts. Spectra of three of the stars indicate two T Tauri stars and a highly obscured B star. 15 references

  11. A synoptic of H-alpha line profile in the T Tauri star SU Aurigae

    Science.gov (United States)

    Giampapa, Mark S.; Basri, Gibor S.; Johns, Christopher M.; Imhoff, Catherine

    1993-01-01

    We present a catalog of 106 high spectral resolution observations of the H-alpha line profile in the T Tauri star SU Aurigae, obtained during the period from 1986 October through 1990 November. The spectra were acquired during joint synoptic programs to observe selected T Tauri stars using the Hamilton Echelle Spectrometer of the Lick Observatory and the solar-stellar spectrograph at the McMath telescope of the National Solar Observatory on Kitt Peak. A restricted set of Mg II h and k line profiles was also obtained in a coordinated program involving the International Ultraviolet Explorer (IUE) satellite observatory and the McMath solar-stellar facility. Striking variability is evident on a nightly basis. A key result is that the relative intensity in the blue wing of H-alpha spanning a range of velocities bear -150 km/s is modulated at a period of 2.98 +/- 0.4 days. We identify the 2.98 day period with the rotation period of the star. We also find that the occurrence of the periodic modulation of the mass outflow is episodic and most evident during a 2 week sequence of nightly observations. We find two other intervals where the periodic spectroscopic variability is likely present, although at a lower level of significance at a lower level of significance. The variability is otherwise stochastic in nature. The Mg II resonance lines exhibit clear variability that is most pronounced in the blue wing of the k line. A comparison of the Mg II k line profile with H-alpha profiles obtained nearly simultaneous yields no apparent correlation between the variable features in each line. The profile shapes of the Mg II h and k lines are generally indicative of formation in a wind. An analysis of the principal features that appear in the H-alpha profile set suggests that the line is composed of contributions from an enhanced chromosphere; a relatively slow moving, dense, optically thick component of a stellar wind formed relatively close to the star; and an optically thin, high-velocity, expanding stellar wind located further away from the star. An investigation of possible correlations among the principal features in the series of H-alpha profiles suggests that as the density in the wind increases, the wind may become more unstable to large turbulence. This may lead to a reduction in the wind bulk velocity, thus regulating the mass-loss rate. We also find that the position of the main absorption feature which is always present in the H-alpha profiles is not correlated with its depth, indicating that optical depth and wind velocity are not correlated in the denser portions of the wind.

  12. HH 666: Different kinematics from H{\\alpha} and [Fe II] emission provide a missing link between jets and outflows

    CERN Document Server

    Reiter, Megan; Kiminki, Megan M; Bally, John

    2015-01-01

    HH 666 is an externally irradiated protostellar outflow in the Carina Nebula for which we present new near-IR [Fe II] spectra obtained with the FIRE spectrograph at Magellan Observatory. Earlier H{\\alpha} and near-IR [Fe II] imaging revealed that the two emission lines trace substantially different morphologies in the inner ~40" of the outflow. H{\\alpha} traces a broad cocoon that surrounds the collimated [Fe II] jet that extends throughout the parent dust pillar. New spectra show that this discrepancy extends to their kinematics. Near-IR [Fe II] emission traces steady, fast velocities of +/- 200 km/s from the eastern and western limbs of the jet. We compare this to a previously published H{\\alpha} spectrum that reveals a Hubble-flow velocity structure near the jet-driving source. New, second-epoch HST/ACS H{\\alpha} images reveal the lateral spreading of the H{\\alpha} outflow lobe away from the jet axis. H{\\alpha} proper motions also indicate a sudden increase in the mass-loss rate ~1000 yr ago, while steady ...

  13. Real-time flare detection in ground-based H$\\alpha$ imaging at Kanzelh\\"ohe Observatory

    CERN Document Server

    Pötzi, Werner; Riegler, Gernot; Amerstorfer, Ulrike; Pock, Thomas; Temmer, Manuela; Polanec, Wolfgang; Baumgartner, Dietmar J

    2014-01-01

    Kanzelh\\"ohe Observatory (KSO) regularly performs high-cadence full-disk imaging of the solar chromosphere in the H$\\alpha$ and CaIIK spectrallines as well as the solar photosphere in white-light. In the frame of ESA's Space Situational Awareness (SSA) programme, a new system for real-time H$\\alpha$ data provision and automatic flare detection was developed at KSO. The data and events detected are published in near real-time at ESA's SSA Space Weather portal (http://swe.ssa.esa.int/web/guest/kso-federated). In this paper, we describe the H$\\alpha$ instrument, the image recognition algorithms developed, the implementation into the KSO H$\\alpha$ observing system and present the evaluation results of the real-time data provision and flare detection for a period of five months. The H$\\alpha$ data provision worked in $99.96$% of the images, with a mean time lag between image recording and online provision of 4s. Within the given criteria for the automatic image recognition system (at least three H$\\alpha$ images a...

  14. Comparing the H-alpha Intensity and Radio Wave Scattering on Eight Low-Latitude Lines of Sight

    Science.gov (United States)

    Simonetti, J. H.; Dennison, B.; Topasna, G. A.

    1995-12-01

    Spangler and Reynolds compared H-alpha intensities, measured using the Wisconsin Fabry-Perot interferometer, with radio-wave scattering sizes of eight extragalactic sources along low-latitiude lines of sight. They find that some correlation exists between scattering and H-alpha intensity, as one might expect. However, the H-alpha observations were made with a 50(') beam size; higher resolution observations might provide a more accurate measure of the intensity along the scattering line of sight. We made sensitive, arcminute resolution H-alpha images of the same fields to upgrade the accuracy of their results. We find that many of their measured H-alpha intensities are accurate, but some of the higher intensities are biased upward by the presence of clumped emission. Appropriate reduction of these large intensities increases the degree of correlation between scattering and H-alpha intensity, thus strengthening their original conclusions. This work is a first step towards using our spectral-line imaging system for a more extensive study of the relationship between the warm ionized medium and scattering of radio waves. This research was supported by NSF grant AST-9319670 and a grant from the Horton Foundation to Virginia Tech.

  15. Calibrating [OII] star-formation rates at z>1 from dual H\\alpha-[OII] imaging from HiZELS

    CERN Document Server

    Hayashi, Masao; Best, Philip N; Smail, Ian; Kodama, Tadayuki

    2012-01-01

    We investigate the relationship between H\\alpha\\ and [OII](\\lambda 3727) emission in faint star-forming galaxies at z=1.47 with dust uncorrected star formation rates (SFRs) down to 1.4 Msun/yr, using data in two narrow-bands from WFCAM/UKIRT and Suprime-Cam/Subaru. A stacking analysis allows us to investigate H\\alpha\\ emission flux from bright [OII] emitters as well as faint ones for which H\\alpha\\ is not individually detected, and to compare them with a large sample of local galaxies. We find that there is a clear, positive correlation between the average H\\alpha\\ and [OII] luminosities for [OII] emitters at z=1.47, with its slope being consistent with the local relation. [OII] emitters at z=1.47 have lower mean observed ratios of H\\alpha/[OII] suggesting a small but systematic offset (at 2.8\\sigma\\ significance) towards lower values of dust attenuation, A(H\\alpha)~0.35, than local galaxies. This confirms that [OII] selection tends to pick up galaxies which are significantly less dusty on average than H\\alph...

  16. Near- And Mid-Infrared Imaging Study of Young Stellar Objects around LkH$\\alpha$ 234

    CERN Document Server

    Kato, Eri; Perrin, Marshall D; Shibai, Hiroshi; Itoh, Yusuke; Ootsubo, Takafumi

    2011-01-01

    We present high-resolution ($0\\farcs2$) near-infrared images of the area surrounding the Herbig Be star LkH$\\alpha$ 234 taken with the Coronagraphic Imager with Adaptive Optics (CIAO) and the adaptive optics on the Subaru Telescope. The near-infrared ($J$, $H$, $K$, $L'$ and $M'$ bands) images reveal circumstellar structures around LkH$\\alpha$ 234 in detail. Eight young stellar object (YSO) candidates (Object B, C, D, E, F, G, NW1, and NW2) were detected at 2$\\arcsec$--11$\\arcsec$ from LkH$\\alpha$ 234. Objects B and C are likely variable stars, which is consistent with a young evolutionary status. Three objects (LkH$\\alpha$ 234, NW1, and NW2) were identified in the 11.8 $\\micron$ (SiC) and 17.65 $\\micron$ images obtained with the Long Wavelength Spectrometer (LWS) on the Keck Telescope. NW1 and NW2 are thought to be embedded young stars. We suggest that NW1 and not LkH$\\alpha$ 234 is the source illuminating the reflection nebula west of LkH$\\alpha$ 234, although Object G may be another candidate. In our image...

  17. The Galactic Halo Ionizing Field and H-alpha Distances to HVCs

    OpenAIRE

    Bland-hawthorn, J.; Maloney, P. R.

    1998-01-01

    There has been much debate in recent decades as to what fraction of ionizing photons from star forming regions in the Galactic disk escape into the halo. The recent detection of the Magellanic Stream in optical line emission at the CTIO 4m and the AAT 3.9m telescopes may now provide the strongest evidence that at least some of the radiation escapes the disk completely. While the distance to the Magellanic Stream is uncertain, the observed H-alpha emission is most plausibly e...

  18. H-alpha emission-line survey of the rho Ophiuchi dark cloud complex

    International Nuclear Information System (INIS)

    Our analysis of two H-alpha objective-prism plates covering about 40 square degrees and including most of the nearby rho Ophiuchi cloud complex is presented. These data provide a high-resolution, completely sampled survey of stars in the T Tauri phase of pre-main-sequence evolution in the lower-extinction regions of the dark cloud. Detailed finder charts and accurate positions for 86 sources of definite or probable H-alpha emission are presented, making this survey useful for future studies of global star formation in the rho Oph clouds. In addition, the first Herbig-Haro object candidates in this area has been found. The correspondence of the emission-line stars with the densest molecular gas and known T Tauri stars, X-ray sources, and IRAS point sources suggest that most of the stars in our sample are indeed young stellar objects. Comparing the number of these objects in the main cloud core with the total number of association members suggests that about 25 percent of the association members are currently observed in the T Tauri phase of evolution near the surface of the cloud. The preponderance of emission-line stars in the western regions of the complex may imply a critical density necessary for star formation to occur or perhaps an actual progression of star formation through the complex. 27 references

  19. H{\\alpha} Kinematics of S4G spiral galaxies I. NGC 864

    CERN Document Server

    Erroz-Ferrer, Santiago; Font, Joan; Beckman, John E; Falcón-Barroso, Jesús; Sánchez-Gallego, José Ramón; Athanassoula, E; Bosma, Albert; Gadotti, Dimitri A; Muñoz-Mateos, Juan Carlos; Sheth, Kartik; Buta, Ronald J; Comerón, Sébastien; de Paz, Armando Gil; Hinz, Joannah L; Ho, Luis C; Kim, Taehyun; Laine, Jarkko; Laurikainen, Eija; Madore, Barry F; Menéndez-Delmestre, Karín; Mizusawa, Trisha; Regan, Michael W; Salo, Heikki; Seibert, Mark

    2012-01-01

    We present a study of the kinematics of the isolated spiral galaxy NGC 864, using H{\\alpha} Fabry-Perot data obtained with the GH{\\alpha}FaS instrument at the William Herschel Telescope in La Palma, complemented with images at 3.6 {\\mu}m, in the R band and in H{\\alpha} filter, and integral field spectroscopic data. The resulting data cubes and velocity maps allow the study of the kinematics of the galaxy, including in-depth investigations of the rotation curve, velocity moment maps, velocity residual maps, gradient maps and position-velocity diagrams. We find asymmetries in the velocity field in the bar zone, caused by non-circular motions, probably in response to the potential of the bar. We also find a flat-profile bar, in agreement with the strong bar, with the grand design spiral pattern, and with the gap between the ends of the bar and the start of the spiral arms. We quantify the rate of massive star formation, which is concentrated in the two spiral arms.

  20. Analysis of EUV, UV, and H-alpha Emission from Two Very Different Prominences

    Science.gov (United States)

    Kucera, T.; Landi, E.

    2008-01-01

    We analyze the properties of a pair of prominences observed the UV and EUV in April 2004. One was a generally quiet prominence which exhibited a period of activation. Another was a large "coronal cloud" type prominence. Both were observed by SOHO/SUMER, TRACE, and in H$\\alpha$ by BBSO and MLSO. The quiet prominence was also observed by the SOHO/CDS instrument. TRACE and H$\\alpha$ data provide 2D images on with time cadences on the order of 1 minute. The SUMER data was taken from a single slit location with a 90 second cadence and included a number of lines spanning the temperature range 80,000 to 1.6 million K. This observing program was designed to allow us to study prominence dynamics . CDS raster data was taken with a slower cadence, in lines formed at temperatures from 20,000 - 1 million K. We combine these different data sets to analyze the thermal properties, including differential emission measures (DEMs), of these very different prominences, and compare the results to those of prominences previously analyzed by ourselves and others.

  1. Galaxies with Background QSOs, I: A Search for Strong Galactic H-alpha Lines

    CERN Document Server

    York, Donald G; Bishof, Michael; Kuttruff, Seth; Bowen, David; Kulkarni, Varsha P; Subbarao, Mark; Richards, Gordon; Berk, Daniel Vanden; Hall, Patrick B; Heckman, Timothy; Khare, Pushpa; Quashnock, Jean; Ghering, Lara; Johnson, Sean

    2012-01-01

    A search for emission lines in foreground galaxies in quasar spectra (z(gal) < z(QSO)) of the Sloan Digital Sky Survey (SDSS) data release 5 (DR5) reveals 23 examples of quasars shining through low redshift, foreground galaxies at small impact parameters (< 10 kpc). About 74,000 quasar spectra were examined by searching for narrow H{\\alpha} emission lines at z < 0.38, at a flux level greater than 5 \\times 10^-17 ergs cm^-2 s^-1, then confirming that other expected emission lines of the H II regions in the galaxy are detected. The galaxies were deblended from the quasar images to get colors and morphologies. For cases that allow the galaxy and the quasar to be deblended, the galaxies are blue (0.95 <(u-r)< 1.95). Extinction and reddening through the galaxies is determined from the (g-i) color excesses of the quasars. These reddening values are compared with the flux ratio of H{\\alpha} to H{\\beta}, which reflect the extinction for an undetermined fraction of the sightline through each galaxy. No ...

  2. A view of the M81 galaxy group via the H-alpha window

    CERN Document Server

    Karachentsev, I D; Karachentsev, Igor D.; Kaisin, Serafim S.

    2007-01-01

    We present images for 36 galaxies of the M81 group obtained in the H-alpha line. Estimates of the H-alpha flux and star formation rate, SFR, are avialable now for all the known members of the group with absolute magnitudes down to M_B = -10^m. The character of distribution of the galaxies over three paremeters: M_B, SFR, and total hydrogen mass permits us to draw the following conclusions as to evolution status of the group population. a) Spiral and irregular type galaxies would have time to generate their luminosity (baryon mass) during the cosmological time T_0=13.7 Gyr, but dwarf spheroidal objects are capable of reproducing only ~5% of their observed luminosity. b) S and Im,BCD galaxies possess the supply of gas sufficient to maintain their observed SFRs during only next (1/4 - 1/3)T_0 years, while dIr and dSph populations have the mean gas depletion time about 3 T_0. c) There is indirect evidence that the star formation in Im, BCD and dIr galaxies proceeds in a mode of vigorous burst activity rather than...

  3. Shocks and Star Formation in Stephan's Quintet. I. Gemini Spectroscopy of H{\\alpha}-bright knots

    CERN Document Server

    Konstantopoulos, I S; Guillard, P; Trancho, G; Cluver, M E; Bastian, N; Charlton, J C; Fedotov, K; Gallagher, S C; Smith, L J; Struck, C J

    2013-01-01

    We present a Gemini-GMOS spectroscopic study of HST-selected H{\\alpha}-emitting regions in Stephan's Quintet (HCG 92), a nearby compact galaxy group, with the aim of disentangling the processes of shock-induced heating and star formation in its intra-group medium. The $\\approx$40 sources are distributed across the system, but most densely concentrated in the $\\sim$kpc-long shock region. Their spectra neatly divide them into narrow- and and broad-line emitters, and we decompose the latter into three or more emission peaks corresponding to spatial elements discernible in HST imaging. The emission line ratios of the two populations of H{\\alpha}-emitters confirm their nature as H II regions (90% of the sample) or molecular gas heated by a shock-front propagating at $\\lesssim$300 km/s. Their redshift distribution reveals interesting three-dimensional structure with respect to gas-phase baryons, with no H II regions associated with shocked gas, no shocked regions in the intruder galaxy NGC 7318B, and a sharp bounda...

  4. An H-alpha search for over-dense regions at z=2.23

    CERN Document Server

    Matsuda, Y; Geach, J E; Best, P N; Sobral, D; Tanaka, I; Ohta, K; Kurk, J; Iwata, I; Bielby, Rich; Wardlow, J L; Bower, R G; Fanidakis, N; Ivison, R J; Kodama, T; Yamada, T; Mawatari, K; Casali, M

    2011-01-01

    We present the results of a narrow-band (H2S1, 2.121/0.021um) imaging search with WFCAM/UKIRT for H-alpha emitters around several potential signposts of rare (10^-7-10^-8 Mpc^-3) over-dense regions at z=2.23: an over-density of QSOs (2QZ cluster), a powerful, high-redshift radio galaxy (HzRG), and a concentration of submillimetre galaxies (SMGs) and optically faint radio galaxies (OFRGs). In total, we detect 137 narrow-band emitter candidates down to emission-line fluxes of 0.5-1 x 10^-16 erg s^-1 cm^-2, across a total area of 0.56 sq. degrees (2.1 x 10^5 comoving Mpc at z=2.23) in these fields. The BzK colours of the emitters suggest that at least 80% of our sample are likely to be H-alpha emitters (HAEs) at z=2.23. This is one of the largest HAE samples known at z>2. We find modest (~3-sigma) local over-densities of emitters associated with all the three targets. In the 2QZ cluster field, the emitters show a striking filamentary structure connecting four of the z=2.23 QSOs extending over 30Mpc (comoving). I...

  5. H_alpha emission fluxes and lithium abundances of low mass stars in the young open cluster IC 4665

    OpenAIRE

    Martin, E. L.; Montes, D.

    1996-01-01

    As part of a long term effort to understand pre-main sequence Li burning, we have obtained high resolution spectroscopic observations of 14 late type stars (G0--M1) in the young open cluster IC~4665. Most of the stars have \\ha filled-in and \\li absorption, as expected for their young age. From the equivalent widths of \\ha emission excess (obtained using the spectral subtraction technique) and the \\lii feature, we have derived \\ha emission fluxes and photospheric Li abundance...

  6. A study of solar flare energy transport based on coordinated H-alpha and X-ray observations

    International Nuclear Information System (INIS)

    The temporal evolution of the ratio between H-alpha to nonthermal hard X-ray emission was investigated using coordinated H-alpha and hard- and soft-X-ray observations of five solar flares (on May 7, June 23, June 24, and June 25, 1980 and on April 30, 1985). These observations were used to estimate the emitted flare energy flux F(H-alpha) in H-alpha, the flux of F(2O) energy deposited by nonthermal electrons with energies above 20 keV, and the pressure p(c) of soft X-ray-emitting plasma as functions of time during the impulsive phase of each flare. It was found that the F(H-alpha)/F(2O) ratio shows a power-law dependence on F(2O), with a slope that differs slightly from that predicted by the static thick-target model of solar transport. Results also indicate that the power-law dependence is modified by hydrostatic pressure effects. 25 refs

  7. H-alpha emitters in z~2 proto-clusters: evidence for faster evolution in dense environments

    CERN Document Server

    Hatch, N A; Pentericci, L; Venemans, B P; Kuiper, E; Miley, G K; Röttgering, H J A

    2011-01-01

    This is a study of H-alpha emitters in two dense galaxy proto-clusters surrounding radio galaxies at z~2. We show that the proto-cluster surrounding MRC 1138-262 contains 14+/-2 times more H-alpha candidates than the average field (9 sigma significance), and the z=2.35 radio galaxy 4C+10.48 is surrounded by 12+/-2 times more emitters than the field (5 sigma), so it is also likely to reside in a dense proto-cluster environment. We compared these H-alpha emitters, situated in dense environments, to a control field sample selected from 3 separate fields forming a total area of 172 arcmin^2. We constructed and compared H-alpha and rest-frame R continuum luminosity functions of the emitters in both environments. The star formation density is on average 13 times greater in the proto-clusters than the field at z~2, so the total star formation rate within the central 1.5Mpc of the proto-clusters exceeds 3000Msun/yr. However, we found no significant difference in the shape of the H-alpha luminosity functions, implying...

  8. Broad H-alpha wings from the optically thin stellar wind of the hot components in symbiotic binaries

    CERN Document Server

    Skopal, A

    2006-01-01

    Aims: To model broad H-alpha wings observed in symbiotic binaries by an optically thin, bipolar stellar wind from their hot components as an alternative to that considering the Raman scattering of Ly-beta photons on atomic hydrogen. Methods: Profile-fitting analysis. Comparison of the observed broad H-alpha wings and their luminosity with those predicted by the model. Results: Synthetic H-alpha profiles fit excellently the observed wings for |RV| > 200 km/s in our sample of 10 symbiotic stars during the quiescent as well as active phases. The wing profile formed in the stellar wind can be approximated by a function f(RV) proportional to RVexp-2, which is of the same type as that arising from the Raman scattering. Therefore it is not possible to distinguish between these two processes only by modeling the line profile. Some observational characteristics of the H-alpha emission suggest the ionized stellar wind from the hot component to be the dominant source contributing to the H-alpha wings during active phase...

  9. H$\\alpha$ tail, intracluster HII regions and star-formation: ESO137-001 in Abell 3627

    CERN Document Server

    Sun, M; Voit, G M

    2007-01-01

    We present the discovery of a 40 kpc H-alpha tail and at least 29 emission-line objects downstream of a star-forming galaxy ESO 137-001 in a rich, nearby cluster A3627. The galaxy is known to possess a dramatic 70 kpc X-ray tail. The detected H-alpha tail coincides positionally with the X-ray tail. The H-alpha emission in the galaxy is sharply truncated on the front and the sides near the nucleus, indicating significant ram pressure stripping. ESO 137-001 is thus the first cluster late-type galaxy known with both an X-ray tail and an H-alpha tail. The emission-line objects are all distributed downstream of the galaxy, with projected distance up to 39 kpc from the galaxy. From the analysis on the H-alpha_{off} frame and the estimate of the background emission-line objects, we conclude that it is very likely all these 29 emission-line objects are HII regions associated with ESO 137-001. The high surface number density and luminosities of these HII regions (up to 10^40 ergs/s) largely dwarf the previously known ...

  10. Chromospheric Sunspot Oscillations in H-alpha and Ca II 8542A

    CERN Document Server

    Maurya, Ram Ajor; Park, Hyungmin; Yang, Heesu; Song, Donguk; Cho, Kyuhyoun

    2013-01-01

    We study chromospheric oscillations including umbral flashes and running penumbral waves in a sunspot of active region (AR) using scanning spectroscopy in H-alpha and Ca II 8542A, with the Fast Imaging Solar Spectrograph (FISS) at the 1.6 meter New Solar Telescope at Big Bear Solar Observatory. A bisector method is applied to spectral observations to construct chromospheric Doppler velocity maps. Temporal sequence analysis of these shows enhanced high-frequency oscillations inside the sunspot umbra in both lines. Their peak frequency gradually decreases outward from the umbra. The oscillation power is found to be associated with magnetic-field strength and inclination, with different relationships in different frequency bands.

  11. Prominence and Cool Loop Energetics Measured in the UV, EUV, and H-alpha

    Science.gov (United States)

    Kucera, Therese A.; Landi, E.

    2006-01-01

    We investigate the thermal and dynamic properties of moving features in a prominence jet, a approx. 10(exp 5)K loop near a prominence channel, and an erupting prominence. In order to make measurements of the quickly moving features seen in prominences in the UV we use the SOHO/SUMER spectrograph to take a time series of exposures from a single pointing position, providing a measurement of spectral line properties as a function of time and position along the slit. The lines observed cover a broad range of temperatures from 80,000 - 1.6 million K. These measurements are combined with TRACE movies in transition region and coronal temperature bands and with ground based H-alpha data to obtain more complete information concerning prominence structure and motions. The resulting observations allow us perform DEM analysis and to calculate limits on densities, pressures, and the thermal and kinetic energies of the moving sources.

  12. Fine structure of the chromospheric activity in Solar-type star - The H-alpha Line

    CERN Document Server

    Lyra, W

    2004-01-01

    A calibration of H-alpha as both a chromospheric diagnostic and an age indicator is presented, complementing the works previously done on this subject (Herbig 1985, Pasquini & Pallavicini 1991. The chromospheric diagnostic was built with a statistically significant sample, covering nine years of observations, and including 175 solar neighborhood stars. Regarding the age indicator, the presence of stars for which very accurate ages are determined, such as those belonging to clusters and kinematic groups, lends confidence to our analysis. We also investigate the possibility that stars of the same age might have gone through different tracks of chromospheric decay, identifying - within the same age range - effects of metallicity and mass. These parameters, however, as well as age, seem to be significant only for dwarf stars, losing their meaning when we analyze stars in the subgiant branch. This result suggests that, in these evolved stars, the emission mechanism cannot be magnetohydrodynamical in nature, in...

  13. Five WC9 stars discovered in the AAO/UKST H-alpha Survey

    CERN Document Server

    Hopewell, E C; Drew, J E; Unruh, Y C; Parker, Q A; Pierce, M J; Crowther, P A; Knigge, C; Phillipps, S; Zijlstra, A A

    2005-01-01

    We report the discovery of 5 massive Wolf-Rayet (WR) stars resulting from a programme of follow-up spectroscopy of candidate emission line stars in the AAO/UKST Southern Galactic Plane H-alpha survey. The 6195-6775 angstrom spectra of the stars are presented and discussed. A WC9 class is assigned to all 5 stars through comparison of their spectra with those of known late-type WC stars, bringing the known total number of Galactic WC9 stars to 44. Whilst three of the five WC9 stars exhibit near infrared (NIR) excesses characteristic of hot dust emission -- as seen in the great majority of known WC9 stars -- we find that two of the stars show no discernible evidence of such excesses. This increases the number of known WC9 stars without NIR excesses to 7. Reddenings and distances for all 5 stars are estimated.

  14. The L-alpha/H-alpha intensity ratio in PKS 0237-23. [quasar

    Science.gov (United States)

    Hyland, A. R.; Becklin, E. E.; Neugebauer, G.

    1978-01-01

    The ratio I(L-alpha)/I(H-alpha) has been measured to be 1.7 plus or minus 0.6 in the quasar PKS 0237-23. The measured ratio is similar to that measured in 3C 273 by Davidsen et al. and to that inferred by Baldwin from a study of a large number of quasars; it is a factor of 5 to 14 smaller than expected from recombination theory. If the L-alpha radiation is resonantly scattered and there are modest amounts of dust within the ionized region, the measured ratio may be interpreted in terms of recombination theory, with L-alpha being depleted by absorption by the dust.

  15. Collisionally excited filaments in HST H$\\alpha$ and H$\\beta$ images of HH~1/2

    CERN Document Server

    Raga, A C; Castellanos-Ramírez, A; Chiang, Hsin-Fang; Bally, J

    2014-01-01

    We present new H$\\alpha$ and H$\\beta$ images of the HH~1/2 system, and we find that the H$\\alpha$/H$\\beta$ ratio has high values in ridges along the leading edges of the HH~1 bow shock and of the brighter condensations of HH~2. These ridges have H$\\alpha$/H$\\beta=4\\to 6$, which is consistent with collisional excitation from the $n=1$ to the $n=3$ and 4 levels of hydrogen in a gas of temperatures $T=1.5\\to 10\\times 10^4$~K. This is therefore the first direct proof that the collisional excitation/ionization region of hydrogen right behind Herbig-Haro shock fronts is detected.

  16. Real-time flare detection in ground-based H$\\alpha$ imaging at Kanzelh\\"ohe Observatory

    OpenAIRE

    Po?tzi, Werner; Veronig, Astrid M.; Riegler, Gernot; Amerstorfer, Ute; Pock, Thomas; Temmer, Manuela; Polanec, Wolfgang; Baumgartner, Dietmar J.

    2014-01-01

    Kanzelh\\"ohe Observatory (KSO) regularly performs high-cadence full-disk imaging of the solar chromosphere in the H$\\alpha$ and CaIIK spectrallines as well as the solar photosphere in white-light. In the frame of ESA's Space Situational Awareness (SSA) programme, a new system for real-time H$\\alpha$ data provision and automatic flare detection was developed at KSO. The data and events detected are published in near real-time at ESA's SSA Space Weather portal (http://swe.ssa....

  17. H-alpha synoptic charts of solar activity during the first year of Solar Cycle 20, October 1964--August 1965

    International Nuclear Information System (INIS)

    Solar activity during the period October 28, 1964 through August 27, 1965 is presented in the form of charts for each solar rotation constructed from observations made with the chromospheric H-alpha spectra line. These H-alpha synoptic charts are identical in format and method of construction to those published for the period of Skylab observations. The sunspot minimum marking the start of Solar Cycle 20 occurred in October, 1964; therefore, charts represent solar activity during the first year of this solar cycle

  18. Optical observations of the nearby galaxy IC342 with narrow band [SII] and H$\\alpha$ filters. I

    CERN Document Server

    Vucetic, M M; Urosevic, D; Dobardzic, A; Pavlovic, M Z; Pannuti, T G; Petrov, N

    2013-01-01

    We present observations of the portion of the nearby spiral galaxy IC342 using narrow band [SII] and H$\\alpha$ filters. These observations were carried out in November 2011 with the 2m RCC telescope at Rozhen National Astronomical Observatory in Bulgaria. In this paper we report coordinates, diameters, H$\\alpha$ and [SII] fluxes for 203 HII regions detected in two fields of view in IC342 galaxy. The number of detected HII regions is 2.5 times higher than previously known in these two parts of the galaxy.

  19. H-Alpha and Hard X-Ray Observations of a Two-Ribbon Flare Associated with a Filament Eruption

    OpenAIRE

    Ding, M. D.; Chen, Q. R.; Li, J. P.; Chen, P. F.

    2003-01-01

    We perform a multi-wavelength study of a two-ribbon flare on 2002 September 29 and its associated filament eruption, observed simultaneously in the H-alpha line by a ground-based imaging spectrograph and in hard X-rays by RHESSI. The flare ribbons contain several H-alpha bright kernels that show different evolutional behaviors. In particular, we find two kernels that may be the footpoints of a loop. A single hard X-ray source appears to cover these two kernels and to move ac...

  20. Equivalent Fractions!

    Science.gov (United States)

    Ms. Pearce

    2011-11-06

    How good at determining equivalent fractions are you? Test your skills with these various fraction games to find out! You have recently been learning about fractions and their equivalency. Try this game to test your knowledge of Equivalent Fractions!! Be sure to notice the "hints" under some of the questions to help you get the correct answer. Good Luck! Continue to master your skills by playing the Dirt Bike Proportions! game. How quickly you ...

  1. H-alpha survey of low-mass satellites of the neighbouring galaxies M31 and M81

    CERN Document Server

    Kaisin, S S

    2013-01-01

    Images have been obtained at the 6-m telescope at the Special Astrophysical Observatory (SAO) of the Russian Academy of Sciences in the H-alpha line and in the continuum for 20 dwarf spheroidal satellites of M31: And XI-And XXX, plus the distant Globular cluster Bol 520. Their star formation rates (FR) are estimated using the H-alpha flux and the ultraviolet FUV flux measured with the GALEX space telescope. Most of the dSph satellites of M31 have extremely low star formation rates with a characteristic upper limit of SFR~5x10^{-7}. We have made similar estimates of SFR from the H-alpha and FUV fluxes for 13 galaxies with low surface brightness recently discovered in the neighborhood of M81. Eleven of them are physical satellites of M81 with typical SFR< 5x10^{-5}. The median stellar masses of these satellites of M31 and M81 are 0.9 and 1.9 million solar masses, respectively. Our H-alpha observations place a 2-3 times stricter limit on the value of SFR than the data from the GALEX satellite, with a substant...

  2. Investigating H$\\alpha$, UV, and IR star-formation rate diagnostics for a large sample of z ~ 2 galaxies

    CERN Document Server

    Shivaei, Irene; Steidel, Charles C; Shapley, Alice E

    2015-01-01

    We use a sample of 262 spectroscopically confirmed star-forming galaxies at redshifts $2.08\\leq z\\leq 2.51$ to compare H$\\alpha$, UV, and IR star-formation-rate diagnostics and to investigate the dust properties of the galaxies. At these redshifts, the H$\\alpha$ line shifts to the $K_{s}$-band. By comparing $K_{s}$-band photometry to underlying stellar population model fits to other UV, optical, and near-infrared data, we infer the H$\\alpha$ flux for each galaxy. We obtain the best agreement between H$\\alpha$- and UV-based SFRs if we assume that the ionized gas and stellar continuum are reddened by the same value and that the Calzetti attenuation curve is applied to both. Aided with MIPS 24$\\mu$m data, we find that an attenuation curve steeper than the Calzetti curve is needed to reproduce the observed IR/UV ratios of galaxies younger than 100 Myr. Furthermore, using the bolometric star-formation rate inferred from the UV and mid-IR data (SFR$_{IR}$+SFR$_{UV}$), we calculated the conversion between the H$\\alp...

  3. Discovery of H-alpha Emission from the Close Companion Inside the Gap of Transitional Disk HD142527

    CERN Document Server

    Close, L M; Males, J R; Puglisi, A; Xompero, M; Apai, D; Najita, J; Weinberger, A J; Morzinski, K; Rodigas, T J; Hinz, P; Bailey, V; Briguglio, R

    2014-01-01

    We utilized the new high-order 585 actuator Magellan Adaptive Optics system (MagAO) to obtain very high-resolution visible light images of HD142527 with MagAO's VisAO science camera. In the median seeing conditions of the 6.5m Magellan telescope (0.5-0.7"), we find MagAO delivers 24-19% Strehl at H-alpha (0.656 microns). We detect a faint companion (HD142527B) embedded in this young transitional disk system at just 86.3+/-1.9 mas (~12 AU) from the star. The companion is detected in both H-alpha and a continuum filter (Delta_mag=6.33+/-0.20 mag at H-alpha and 7.50+/-0.25 mag in the continuum filter). This provides confirmation of the tentative companion discovered by Biller and co-workers with sparse aperture masking at the 8m VLT. The H-alpha emission from the ~0.25 solar mass companion (EW=180 Angstroms) implies a mass accretion rate of ~5.9x10^-10 Msun/yr, and a total accretion luminosity of 1.2% Lsun. Assuming a similar accretion rate, we estimate that a 1 Jupiter mass gas giant could have considerably bet...

  4. Comparison of H-alpha and UV Star Formation Rates in the Local Volume: Systematic Discrepancies for Dwarf Galaxies

    CERN Document Server

    Lee, Janice C; Tremonti, Christy; Kennicutt, Robert C; Salim, Samir; Bothwell, Matthew; Calzetti, Daniela; Dalcanton, Julianne; Dale, Daniel; Engelbracht, Chad; J., Jose G Funes S; Johnson, Benjamin; Sakai, Shoko; Skillman, Evan; van Zee, Liese; Walter, Fabian; Weisz, Daniel

    2009-01-01

    (abridged) Using a complete sample of ~300 star-forming galaxies within 11 Mpc, we evaluate the consistency between star formation rates (SFRs) inferred from the far ultraviolet (FUV) non-ionizing continuum and H-alpha nebular emission, assuming standard conversion recipes in which the SFR scales linearly with luminosity at a given wavelength. Our analysis probes SFRs over 5 orders of magnitude, down to ultra-low activities on the order of ~0.0001 M_sun/yr. The data are drawn from the 11 Mpc H-alpha and Ultraviolet Galaxy Survey (11HUGS), which has obtained H-alpha fluxes from ground-based narrowband imaging, and UV fluxes from imaging with GALEX. For normal spiral galaxies (SFR~1 M_sun/yr), our results are consistent with previous work which has shown that FUV SFRs tend to be lower than H-alpha SFRs before accounting for internal dust attenuation, but that there is relative consistency between the two tracers after proper corrections are applied. However, a puzzle is encountered at the faint end of the lumin...

  5. Strong H-alpha Emission Detected in the M33 Nova Candidate PNV J01340288+3035111

    Science.gov (United States)

    Hornoch, K.; Vaduvescu, O.; Tudor, V.

    2014-07-01

    We obtained four 240-s narrow-band H-alpha and four 120-s R-band CCD frames of M33 on 2014 July 29.206 and 29.222 UT, respectively, with the 2.5-m Isaac Newton Telescope (INT) + WFC at La Palma under ~1.1" seeing.

  6. Discovery of an Apparent Nova in M81 and H-alpha Confirmation of Three M81 Nova Candidates

    Science.gov (United States)

    Hornoch, K.; Vaduvescu, O.; Tudor, V.

    2014-06-01

    We report the discovery of an apparent nova in M81 on a co-added 2000-s narrow-band H-alpha CCD image taken with the 2.5-m Isaac Newton Telescope (INT) + WFC at La Palma under ~1.6" seeing on 2014 Jun. ...

  7. H-alpha kinematics of a z ~ 1 disc galaxy from near-IR integral field spectroscopy

    CERN Document Server

    Smith, J K; Vogt, N P; Abraham, R G; Aragón-Salamanca, A; Bower, R G; Parry, I R; Sharp, R G; Swinbank, A M

    2004-01-01

    In this letter we present the first 3D spectroscopic study of H-alpha emission in a z ~ 1 field galaxy with an integral field unit. Using the CIRPASS spectrograph on Gemini-South we map the spatial and velocity distribution of H-alpha emission in the z=0.819 galaxy CFRS 22.1313. We detect two H-alpha emitting regions with a velocity separation of 220+/-10 km/s. Combining the 2D map of H-alpha emission with HST F814W imaging, we determine a lower limit of 180+/-20 km/s for the rotation velocity of this M_B(rest) ~ -21 galaxy. We note that our value is significantly higher than the rotation velocity of 120+/-10km/s reported by Barden et al. (2003) for their long-slit spectroscopic study of this galaxy. Our lower limit on the rotation velocity is entirely consistent with no evolution of the rest B-band Tully-Fisher relation. The position of this galaxy relative to the mean rest B-band Tully-Fisher relation of Tully & Pierce (2000) is consistent with brightening of no more than ~ 1mag at z=0.8. A larger integ...

  8. FIRST SIMULTANEOUS OBSERVATION OF AN H{alpha} MORETON WAVE, EUV WAVE, AND FILAMENT/PROMINENCE OSCILLATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Asai, Ayumi; Isobe, Hiroaki [Unit of Synergetic Studies for Space, Kyoto University, Yamashina, Kyoto 607-8471 (Japan); Ishii, Takako T.; Kitai, Reizaburo; Ichimoto, Kiyoshi; UeNo, Satoru; Nagata, Shin' ichi; Morita, Satoshi; Nishida, Keisuke; Shibata, Kazunari [Kwasan and Hida Observatories, Kyoto University, Yamashina, Kyoto 607-8471 (Japan); Shiota, Daikou [Advanced Science Institute, RIKEN, Wako, Saitama 351-0198 (Japan); Oi, Akihito [College of Science, Ibaraki University, Mito, Ibaraki 310-8512 (Japan); Akioka, Maki, E-mail: asai@kwasan.kyoto-u.ac.jp [Hiraiso Solar Observatory, National Institute of Information and Communications Technology, Hitachinaka, Ibaraki 311-1202 (Japan)

    2012-02-15

    We report on the first simultaneous observation of an H{alpha} Moreton wave, the corresponding EUV fast coronal waves, and a slow and bright EUV wave (typical EIT wave). We observed a Moreton wave, associated with an X6.9 flare that occurred on 2011 August 9 at the active region NOAA 11263, in the H{alpha} images taken by the Solar Magnetic Activity Research Telescope at Hida Observatory of Kyoto University. In the EUV images obtained by the Atmospheric Imaging Assembly on board the Solar Dynamic Observatory we found not only the corresponding EUV fast 'bright' coronal wave, but also the EUV fast 'faint' wave that is not associated with the H{alpha} Moreton wave. We also found a slow EUV wave, which corresponds to a typical EIT wave. Furthermore, we observed, for the first time, the oscillations of a prominence and a filament, simultaneously, both in the H{alpha} and EUV images. To trigger the oscillations by the flare-associated coronal disturbance, we expect a coronal wave as fast as the fast-mode MHD wave with the velocity of about 570-800 km s{sup -1}. These velocities are consistent with those of the observed Moreton wave and the EUV fast coronal wave.

  9. H$\\alpha$ spectroscopy and multi-wavelength imaging of a solar flare caused by filament eruption

    CERN Document Server

    Huang, Z; Koleva, K; Doyle, J G; Duchlev, P; Dechev, M; Reardon, K

    2014-01-01

    We study a sequence of eruptive events including filament eruption, a GOES C4.3 flare and a coronal mass ejection. We aim to identify the possible trigger(s) and precursor(s) of the filament destabilisation; investigate flare kernel characteristics; flare ribbons/kernels formation and evolution; study the interrelation of the filament-eruption/flare/coronal-mass-ejection phenomena as part of the integral active-region magnetic field configuration; determine H alpha line profile evolution during the eruptive phenomena. Multi-instrument observations are analysed including H$\\alpha$ line profiles, speckle images at H$\\alpha$-0.8 \\AA\\ and H$\\alpha$+0.8 \\AA\\ from IBIS at DST/NSO, EUV images and magnetograms from the SDO, coronagraph images from STEREO and the X-ray flux observations from FERMI and GOES. We establish that the filament destabilisation and eruption are the main trigger for the flaring activity. A surge-like event with a circular ribbon in one of the filament footpoints is determined as the possible t...

  10. An Atlas of H-alpha and R Images and Radial Profiles of 29 Bright Isolated Spiral Galaxies

    CERN Document Server

    Koopmann, R A

    2005-01-01

    Narrow-band H-alpha+[NII] and broadband R images and surface photometry are presented for a sample of 29 bright (M_B < -18) isolated S0-Scd galaxies within a distance of 48 Mpc. These galaxies are among the most isolated nearby spiral galaxies of their Hubble classifications as determined from the Nearby Galaxies Catalog (Tully 1987a).

  11. Development of a high-speed H-alpha camera system for the observation of rapid fluctuations in solar flares

    International Nuclear Information System (INIS)

    A solid-state digital camera was developed for obtaining H alpha images of solar flares with 0.1 s time resolution. Beginning in the summer of 1988, this system will be operated in conjunction with SMM's hard X-ray burst spectrometer (HXRBS). Important electron time-of-flight effects that are crucial for determining the flare energy release processes should be detectable with these combined H alpha and hard X-ray observations. Charge-injection device (CID) cameras provide 128 x 128 pixel images simultaneously in the H alpha blue wing, line center, and red wing, or other wavelength of interest. The data recording system employs a microprocessor-controlled, electronic interface between each camera and a digital processor board that encodes the data into a serial bitstream for continuous recording by a standard video cassette recorder. Only a small fraction of the data will be permanently archived through utilization of a direct memory access interface onto a VAX-750 computer. In addition to correlations with hard X-ray data, observations from the high speed H alpha camera will also be correlated and optical and microwave data and data from future MAX 1991 campaigns. Whether the recorded optical flashes are simultaneous with X-ray peaks to within 0.1 s, are delayed by tenths of seconds or are even undetectable, the results will have implications on the validity of both thermal and nonthermal models of hard X-ray production

  12. Development of a high-speed H-alpha camera system for the observation of rapid fluctuations in solar flares

    Science.gov (United States)

    Kiplinger, Alan L.; Dennis, Brian R.; Orwig, Larry E.; Chen, P. C.

    1988-01-01

    A solid-state digital camera was developed for obtaining H alpha images of solar flares with 0.1 s time resolution. Beginning in the summer of 1988, this system will be operated in conjunction with SMM's hard X-ray burst spectrometer (HXRBS). Important electron time-of-flight effects that are crucial for determining the flare energy release processes should be detectable with these combined H alpha and hard X-ray observations. Charge-injection device (CID) cameras provide 128 x 128 pixel images simultaneously in the H alpha blue wing, line center, and red wing, or other wavelength of interest. The data recording system employs a microprocessor-controlled, electronic interface between each camera and a digital processor board that encodes the data into a serial bitstream for continuous recording by a standard video cassette recorder. Only a small fraction of the data will be permanently archived through utilization of a direct memory access interface onto a VAX-750 computer. In addition to correlations with hard X-ray data, observations from the high speed H alpha camera will also be correlated and optical and microwave data and data from future MAX 1991 campaigns. Whether the recorded optical flashes are simultaneous with X-ray peaks to within 0.1 s, are delayed by tenths of seconds or are even undetectable, the results will have implications on the validity of both thermal and nonthermal models of hard X-ray production.

  13. Natural widths of hypersatellite K-X-ray lines and lifetimes of double K-hole states in mid-Z atoms

    Energy Technology Data Exchange (ETDEWEB)

    Rzadkiewicz, J. [Andrzej Soltan Institute for Nuclear Studies, 05-400 Swierk (Poland)]. E-mail: jacek@iriss.ipj.gov.pl; Chmielewska, D. [Andrzej Soltan Institute for Nuclear Studies, 05-400 Swierk (Poland); Sujkowski, Z. [Andrzej Soltan Institute for Nuclear Studies, 05-400 Swierk (Poland); Berset, M. [Physics Department, University of Fribourg, CH-1700 Fribourg (Switzerland); Dousse, J.-Cl. [Physics Department, University of Fribourg, CH-1700 Fribourg (Switzerland); Maillard, Y.-P. [Physics Department, University of Fribourg, CH-1700 Fribourg (Switzerland); Mauron, O. [Physics Department, University of Fribourg, CH-1700 Fribourg (Switzerland); Raboud, P.-A. [Physics Department, University of Fribourg, CH-1700 Fribourg (Switzerland); Polasik, M. [Faculty of Chemistry, Nicholas Copernicus University, 87-100 Torun (Poland); SIabkowska, K. [Faculty of Chemistry, Nicholas Copernicus University, 87-100 Torun (Poland); Hoszowska, J. [European Synchrotron Radiation Facility ESRF, F-38043 Grenoble (France); Pajek, M. [Institute of Physics, Akademia Swietokrzyska, 25-406 Kielce (Poland)

    2005-07-01

    K-X-ray spectra of Zr, Nb, Mo and Pd targets bombarded with 250 MeV carbon and 360 MeV oxygen ions are studied with high resolution diffraction spectrometry. Relative yields and natural widths of the K{sup h}{alpha}{sub 1,2} hypersatellite lines are determined and compared with those of the diagram lines. The widths of K{sup h}{alpha}{sub 1,2} lines are compared with the new phenomenological formula which takes into account the retardation of the K{sup h}{alpha}{sub 1} transition in the LS coupling scheme. The data significantly exceed the expected values. Deduced lifetimes of the double K-hole states are shorter than expected.

  14. Effects of metal cations on [3H]alpha,beta-methylene ATP binding in rat vas deferens.

    Science.gov (United States)

    Michel, A D; Humphrey, P P

    1994-08-01

    In this study we have examined the effect of metal cations (as their chloride salts) on the binding of [3H]alpha,beta-methylene ATP ([3H]alpha beta meATP) to rat vas deferens membranes using a vacuum filtration receptor binding assay. Whereas NaCl and KCl (0.01 and 30 mM) did not affect total binding of 1 nM [3H]alpha beta meATP, several divalent and trivalent cation salts markedly increased binding. The trivalent cation salts, FeCl3 and AlCl3 (0.1 to 100 microM), produced the greatest increases in total binding of [3H]alpha beta meATP, however, their effects were most probably due to precipitation of the radioligand. In contrast, several divalent cations, at concentrations between 1 microM and 1-10 mM, increased total binding of [3H]alpha beta meATP to rat vas deferens by between 87% and 215% while having no effect on either filter binding or non specific binding. The following pEC50 values for potentiating binding of the radioligand were obtained: ZnCl2 (5.44), MnCl2 (4.52), CaCl2 (4.17), CoCl2 (4.06), MgCl2 (3.67) and BaCl2 (3.10). Both EDTA and EGTA (0.01-1 mM) inhibited the binding of the radioligand. The effects of ZnCl2, CaCl2 and MgCl2 were examined in saturation studies. In the absence of added divalent cations, [3H]alpha beta meATP labelled both high (pKd = 9.15) and low (pKd = 7.06) affinity binding sites. The affinity of the radioligand for its high affinity sites was increased by 3 mM CaCl2 (pKd = 9.56) and by 30 microM ZnCl2 (pKd = 9.46) but not by 3 mM MgCl2. The Bmax of the low affinity site for [3H]alpha beta meATP was increased (approximately 4 fold) by both 3 mM MgCl2 and 30 microM ZnCl2 but not by 3 mM CaCl2. The selective effect of CaCl2 on the high affinity binding sites enabled these sites to be labelled in the presence of 3 mM CaCl2 using a low concentration of [3H]alpha beta meATP (1 nM); the sites exhibited the binding characteristics expected of the P2x purinoceptor. The selective effect of MgCl2 on the low affinity binding sites enabled these sites to be labelled in the presence of 3 mM MgCl2 and using a high concentration of [3H]alpha beta meATP (100 nM). A comparison of the binding characteristics of the high and low affinity sites for [3H]alpha beta meATP revealed several other differences, in addition to their cation selectivity.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:7990967

  15. The Tremaine-Weinberg method for pattern speeds using H-alpha emission from ionized gas

    CERN Document Server

    Beckman, John E; Piñol, Núria; Toonen, Silvia; Hernandez, Olivier; Carignan, Claude

    2007-01-01

    The Fabry-Perot interferometer FaNTOmM was used at the 3.6m Canada France Hawaii Telescope and the 1.6m Mont Megantic Telescope to obtain data cubes in H-alpha of 9 nearby spiral galaxies from which maps in integrated intensity, velocity, and velocity dispersion were derived. We then applied the Tremaine-Weinberg method, in which the pattern speed can be deduced from its velocity field, by finding the integrated value of the mean velocity along a slit parallel to the major axis weighted by the intensity and divided by the weighted mean distance of the velocity points from the tangent point measured along the slit. The measured variables can be used either to make separate calculations of the pattern speed and derive a mean, or in a plot of one against the other for all the points on all slits, from which a best fit value can be derived. Linear fits were found for all the galaxies in the sample. For two galaxies a clearly separate inner pattern speed with a higher value, was also identified and measured.

  16. GH $\\alpha$ FaS : Galaxy H-alpha Fabry-Perot System for the WHT

    CERN Document Server

    Hernández, O; Carignan, C; Beckman, J; Gach, J L; Balard, P; Amram, P; Boulesteix, J; Corradi, R L M; de Denus-Baillargeon, M-M; Epinat, B; Relaño, M; Thibault, S; Vallée, P

    2008-01-01

    GH$\\alpha$FaS a new Fabry-Perot system, is now available at the William Herschel Telescope. It was mounted, for the first time, at the Nasmyth focus of the 4.2 meter WHT on La Palma in July 2007. Using modern technology, with a spectral resolution of the order R$\\sim$15000, and with a seeing limited spatial resolution, GH$\\alpha$FaS will provide a new look at the H$\\alpha$ -emitting gas over a 4.8 arcminutes circular field in the nearby universe. Many science programs can be done on a 4.2 metre class telescope in world class seeing conditions with a scanning Fabry-Perot. Not only galaxies but HII regions, planetary nebulae, supernova remnants and the diffuse interstellar medium are subjects for which unique data can be aquired rapidly. Astronomers from the Laboratoire d'Astrophysique Exp\\'erimentale (LAE) in Montr\\'eal, the Laboratoire d'Astrophysique de Marseille (LAM-OAMP), and the Instituto de Astrof\\'isica de Canarias (IAC), have inaugurated GH$\\alpha$FaS by studying in detail the dynamics of some nearby ...

  17. Pattern Speeds of Bars and Spiral Arms From H-alpha Velocity Fields

    CERN Document Server

    Fathi, Kambiz; Piñol-Ferrer, Nuria; Hernandez, Olivier; Martinez-Valpuesta, Inma; Carignan, Claude

    2009-01-01

    We have applied the Tremaine-Weinberg method to 10 late-type barred spiral galaxies using data cubes, in H-alpha emission, from the GHAFAS and FANTOMM Fabry-Perot spectrometers. We have combined the derived bar (and/or spiral) pattern speeds with angular frequency plots to measure the corotation radii for the bars in these galaxies. We base our results on a combination of this method with a morphological analysis designed to estimate the corotation radius to bar-length ratio using two independent techniques on archival near infrared images, and although we are aware of the limitation of the application of the Tremaine-Weinberg method using ionised gas observations, we find consistently excellent agreement between bar and spiral arm parameters derived using different methods. In general, the corotation radius, measured using the Tremaine-Weinberg method, is closely related to the bar length, measured independently from photometry and consistent with previous studies. Our corotation/bar-length ratios and patter...

  18. Proper Motions of H-alpha filaments in the Supernova Remnant RCW 86

    CERN Document Server

    Helder, E A; Bamba, A; Bleeker, J A M; Burrows, D N; Ghavamian, P; Yamazaki, R

    2013-01-01

    We present a proper motion study of the eastern shock-region of the supernova remnant RCW 86 (MSH 14-63, G315.4-2.3), based on optical observations carried out with VLT/FORS2 in 2007 and 2010. For both the northeastern and southeastern regions, we measure an average proper motion of H-alpha filaments of 0.10 +/- 0.02 arcsec/yr, corresponding to 1200 +/- 200 km/s at 2.5kpc. There is substantial variation in the derived proper motions, indicating shock velocities ranging from just below 700 km/s to above 2200 km/s. The optical proper motion is lower than the previously measured X-ray proper motion of northeastern region. The new measurements are consistent with the previously measured proton temperature of 2.3 +/- 0.3 keV, assuming no cosmic-ray acceleration. However, within the uncertainties, moderately efficient (< 27 per cent) shock acceleration is still possible. The combination of optical proper motion and proton temperature rule out the possibility that RCW 86 has a distance less than 1.5kpc. The simil...

  19. A census of H$\\alpha$ emitters in the intergalactic medium of the NGC 2865 system

    CERN Document Server

    Urrutia-Viscarra, F; de Oliveira, C Mendes; Gerhard, O; Torres-Flores, S; Carrasco, E R; de Mello, D

    2014-01-01

    Tidal debris which are rich in HI gas, formed in interacting and merging systems, are suitable laboratories to study star formation outside galaxies. Recently, several such systems were observed, which contained many young star forming regions outside the galaxies. In previous works, we have studied young star forming regions outside galaxies in different systems with optical and/or gaseous tidal debris, all of them with available archive GALEX/UV images, in order to understand how often they occur and in which type of environments. In this paper we searched for star forming regions around the galaxy NGC2865, a shell galaxy which is circled by a ring of HI, with a total mass of 1.2 x 10$^9$ M$_\\odot$. Using the Multi-Slit Imaging Spectroscopy Technique with the Gemini telescope, we detected all H$\\alpha$ emitting sources in the surroundings of the galaxy NGC2865, down to a flux limit of 10$^{-18}$ erg cm$^{-2}$ s$^{-1}$ \\AA$^{-1}$. Together with Near and Far-Ultraviolet flux information we characterize the st...

  20. The H$\\alpha$ kinematics of interacting galaxies in 12 compact groups

    CERN Document Server

    Torres-Flores, S; de Oliveira, C Mendes; Plana, H; Balkowski, C; Marcelin, M; Olave-Rojas, D

    2014-01-01

    We present new Fabry-Perot observations for a sample of 42 galaxies located in twelve compact groups of galaxies: HCG 1, HCG 14, HCG 25, HCG 44, HCG 53, HCG 57, HCG 61, HCG 69, HCG 93, VV 304, LGG 455 and Arp 314. From the 42 observed galaxies, a total of 26 objects are spiral galaxies, which range from Sa to Im morphological types. The remaining 16 objects are E, S0 and S0a galaxies. Using these observations, we have derived velocity maps, monochromatic and velocity dispersion maps for 24 galaxies, where 18 are spiral, three are S0a, two are S0 and one is an Im galaxy. From the 24 velocity fields obtained, we could derive rotation curves for 15 galaxies; only two of them exhibit rotation curves without any clear signature of interactions. Based on kinematic information, we have evaluated the evolutionary stage of the different groups of the current sample. We identify groups that range from having no H$\\alpha$ emission to displaying an extremely complex kinematics, where their members display strongly pertur...

  1. Miocrowave spectral imaging, H-alpha and hard X-ray observations of a solar limb flare

    Science.gov (United States)

    Wang, H.; Gary, D. E.; Lim, J.; Schwartz, R. A.

    1994-01-01

    We compare the microwave, H-alpha, and hard X-ray observations for a west limb C7.3 flare that occurred at 17:10 UT, 1992 June 26. H-alpha movies were obtained at Big Bear Solar Observatory. Before the onset of the flare, overexposed H-alpha images show the complicated flux loop structure above the limb. Material was observed to descend along the loops toward the site where the flare occurred hours later. Using the five-antenna solar array at Owens Valley Radio Observatory, we obtain two-dimensional maps of flare emission from 1.4 to 14 GHz. In all three temporal peaks of the microwave bursts, the maps show the same characteristics. The peak low-frequency emission comes from the top of one bundle of the H-alpha loops and gradually shifts to the foot-point of the loops (the location of H-alpha flare) as the frequency increases. The location of the emission peak shifts 88 sec between 1 and 14 GHz. Seventy percent of the shift occurs between 1 and 5 GHz. The locus of the shift of the emission peak follows the shape of an H-alpha surge that occurred after the flare. For each point along the locus, we create the microwave brightness temperature spectrum and compare the radio-derived electron distribution with that derived from the high-resolution hard X-ray spectra measured with Burst and Transient Source Experiment (BATSE) on board the Compton Gamma Ray Observatory (CGRO). We find that the peak frequency changes from approximately 3 GHz at the loop top to approximately 7 GHz at the footprint, presumably due to the increase of the magnetic field from approximately 160 GHz at the loop top to approximately 300 G at the footpoint. The high-frequency slope of the microwave power-law spectrum decreases from approximately 10 at the loop top to approximately 5 at the footprint due to a change in the energy distribution of the dominant electrons. The microwave brightness temperature spectral index predicted by the BATSE power-law hard X-ray spectra agrees with the measured value only at the footpoint. At the loop top, the emission may be thermal gyrosynchrotron with a temperature of 3.5 x 10(exp 7) K, which is likely to correspond to the superhot component seen in the hard X-ray emission.

  2. High specific activity N-Acetyl-3{sup H}-{alpha}-Aspartyl- L-Glutamic at micro mole scale; Sintesis de N-Acetil-3{sup H}- {alpha} -Aspartil-Glutamico a escala de Micromoles

    Energy Technology Data Exchange (ETDEWEB)

    Suarez, C.

    1984-07-01

    High specific activity N-Acetyl-3{sup H}- {alpha} -Aspartyl-I-Glutamic acid at micro mole scale in prepared acetylating L- {alpha} -Aspartyl-L-glutamic with 3{sup H}-acetic anhydride in re distilled toluene. The product le purified through cationic and anionic columns. The radiochemical purity as determined by thin-layer chromatography is greater then 99% at the time preparation. (Author) 5 refs.

  3. FUNDPAR: A program for Deriving Fundamental Parameters from Equivalent Widths

    Directory of Open Access Journals (Sweden)

    C. Saffe

    2011-01-01

    Full Text Available Implementamos un programa en Fortran que determina parámetros fundamentales de estrellas de tipo solar, a partir de anchos equivalentes del Fe. La solución debe verificar tres condiciones en el método estándar: equilibrio de ionización, equilibrio de excitación e independencia entre abundancias y anchos equivalentes. Calculamos modelos de atmósfera de Kurucz con opacidades NEWODF. Detalles como el parámetro de longitud de mezcla, el sobre impulso convectivo, etc. se calculan con un programa independiente. FUNDPAR calcula las incertezas por dos métodos: el criterio de Gonzalez & Vanture (1998 y utilizando la función ?² . Los resultados derivados con FUNDPAR están de acuerdo con determinaciones previas en la literatura. En particular obtuvimos parámetros fundamentales de 58 estrellas con exoplanetas. El programa está disponible en la red1.

  4. Ionized gas in elliptical and S0 galaxies. I. A survey for H-alpha and forbidden N II emission

    International Nuclear Information System (INIS)

    A spectroscopic survey of a large sample of southern E and S0 galaxies in order to detect ionized gas in the nuclei is reported. The strongest line in the 6000-7000 A range was nearly always forbidden N II 6584 A, followed by H-alpha and forbidden S II 6716, 6731 A. Identical detection rates of about 50 percent were obtained for the forbidden N II line in both E and S0 galaxies. The mass of ionized gas in early-type galaxies was very small, with values typically in the range 1000-10,000 solar masses. The relative emission-line strengths in virtually every case were indistinguishable from those of LINER nuclei. The observed values of the forbidden N II 6584 A/H-alpha ratios fell mostly between one and three and seem correlated with galaxy absolute magnitude. The existence of such a correlation may be indicative of metallicity differences. 58 references

  5. A high-speed digital camera system for the observation of rapid H-alpha fluctuations in solar flares

    International Nuclear Information System (INIS)

    Researchers developed a prototype digital camera system for obtaining H-alpha images of solar flares with 0.1 s time resolution. They intend to operate this system in conjunction with SMM's Hard X Ray Burst Spectrometer, with x ray instruments which will be available on the Gamma Ray Observatory and eventually with the Gamma Ray Imaging Device (GRID), and with the High Resolution Gamma-Ray and Hard X Ray Spectrometer (HIREGS) which are being developed for the Max '91 program. The digital camera has recently proven to be successful as a one camera system operating in the blue wing of H-alpha during the first Max '91 campaign. Construction and procurement of a second and possibly a third camera for simultaneous observations at other wavelengths are underway as are analyses of the campaign data

  6. A high-speed digital camera system for the observation of rapid H-alpha fluctuations in solar flares

    Science.gov (United States)

    Kiplinger, Alan L.; Dennis, Brian R.; Orwig, Larry E.

    1989-01-01

    Researchers developed a prototype digital camera system for obtaining H-alpha images of solar flares with 0.1 s time resolution. They intend to operate this system in conjunction with SMM's Hard X Ray Burst Spectrometer, with x ray instruments which will be available on the Gamma Ray Observatory and eventually with the Gamma Ray Imaging Device (GRID), and with the High Resolution Gamma-Ray and Hard X Ray Spectrometer (HIREGS) which are being developed for the Max '91 program. The digital camera has recently proven to be successful as a one camera system operating in the blue wing of H-alpha during the first Max '91 campaign. Construction and procurement of a second and possibly a third camera for simultaneous observations at other wavelengths are underway as are analyses of the campaign data.

  7. M/L, H-alpha Rotation Curves, and HI Measurements for 329 Nearby Cluster and Field Spirals: I. Data

    OpenAIRE

    Vogt, Nicole P.; Haynes, Martha P.; Herter, Terry; Giovanelli, Riccardo

    2004-01-01

    A survey of 329 nearby galaxies (redshift z < 0.045) has been conducted to study the distribution of mass and light within spiral galaxies over a range of environments. The 18 observed clusters and groups span a range of richness, density, and X-ray temperature, and are supplemented by a set of 30 isolated field galaxies. Optical spectroscopy taken with the 200-inch Hale Telescope provides separately resolved H-alpha and [NII] major axis rotation curves for the complete set ...

  8. High spatial resolution continuum and H-alpha imaging of the high-redshift IRAS source FSC 10214+4724

    Science.gov (United States)

    Soifer, B. T.; Neugebauer, G.; Matthews, K.; Lawrence, C.; Mazzarella, J.

    1992-01-01

    New observations are reported which support the view that the high-redshift IRAS source FSC 10214+4724 is a rare extreme example of the class of ultraluminous infrared galaxies observed in the local universe. The presence of two continuum components and a compact H-alpha source suggests that a merger between two or more gas-rich systems has triggered the production of a powerful dust-enshrouded quasar which is responsible for the bulk of the luminosity.

  9. The 1640.4 A H-alpha line of He II observed from Skylab. [solar spectra

    Science.gov (United States)

    Feldman, U.; Doschek, G. A.; Vanhoosier, M. E.; Tousey, R.

    1975-01-01

    Profiles obtained from NRL Skylab solar spectra of the 1640.4 A feature identified as the H-alpha line of He II are discussed and compared with theoretical profiles derived assuming (1) collisional excitation and (2) radiative recombination as the dominant excitation mechanism. Relative intensities of this line as a function of altitude above and below the solar white-light limb are also given for a representative quiet sun region and for a polar coronal hole.

  10. The Second Data Release of the INT Photometric H\\alpha\\ Survey of the Northern Galactic Plane (IPHAS DR2)

    CERN Document Server

    Barentsen, Geert; Drew, J E; González-Solares, E A; Greimel, R; Irwin, M J; Miszalski, B; Ruhland, C; Groot, P; Mampaso, A; Sale, S E; Henden, A A; Aungwerojwit, A; Barlow, M J; Carter, P J; Corradi, R L M; Drake, J J; Eislöffel, J; Fabregat, J; Gänsicke, B T; Fusillo, N P Gentile; Greiss, S; Hales, A S; Hodgkin, S; Huckvale, L; Irwin, J; King, R; Knigge, C; Kupfer, T; Lagadec, E; Lennon, D J; Lewis, J R; Mohr-Smith, M; Morris, R A H; Naylor, T; Parker, Q A; Phillipps, S; Pyrzas, S; Raddi, R; Roelofs, G H A; Rodríguez-Gil, P; Sabin, L; Scaringi, S; Steeghs, D; Suso, J; Tata, R; Unruh, Y C; van Roestel, J; Viironen, K; Vink, J S; Walton, N A; Wright, N J; Zijlstra, A A

    2014-01-01

    The INT/WFC Photometric H-Alpha Survey of the Northern Galactic Plane (IPHAS) is a 1800 square degrees imaging survey covering Galactic latitudes |b| < 5 deg and longitudes l = 30 to 215 deg in the r, i and H\\alpha\\ filters using the Wide Field Camera (WFC) on the 2.5-metre Isaac Newton Telescope (INT) in La Palma. We present the first quality-controlled and globally-calibrated source catalogue derived from the survey, providing single-epoch photometry for 219 million unique sources across 92% of the footprint. The observations were carried out between 2003 and 2012 at a median seeing of 1.1 arcsec (sampled at 0.33 arcsec/pixel) and to a mean 5\\sigma-depth of 21.2 (r), 20.0 (i) and 20.3 (H\\alpha) in the Vega magnitude system. We explain the data reduction and quality control procedures, describe and test the global re-calibration, and detail the construction of the new catalogue. We show that the new calibration is accurate to 0.03 mag (rms) and recommend a series of quality criteria to select the most rel...

  11. H-Alpha and Hard X-Ray Observations of a Two-Ribbon Flare Associated with a Filament Eruption

    CERN Document Server

    Ding, M D; Li, J P; Chen, P F

    2003-01-01

    We perform a multi-wavelength study of a two-ribbon flare on 2002 September 29 and its associated filament eruption, observed simultaneously in the H-alpha line by a ground-based imaging spectrograph and in hard X-rays by RHESSI. The flare ribbons contain several H-alpha bright kernels that show different evolutional behaviors. In particular, we find two kernels that may be the footpoints of a loop. A single hard X-ray source appears to cover these two kernels and to move across the magnetic neutral line. We explain this as a result of the merging of two footpoint sources that show gradually asymmetric emission owing to an asymmetric magnetic topology of the newly reconnected loops. In one of the H-alpha kernels, we detect a continuum enhancement at the visible wavelength. By checking its spatial and temporal relationship with the hard X-ray emission, we ascribe it as being caused by electron beam precipitation. In addition, we derive the line-of-sight velocity of the filament plasma based on the Doppler shif...

  12. Star-forming regions in gas-rich lenticulars. I. H-alpha imaging of an initial sample of galaxies

    International Nuclear Information System (INIS)

    The first results of an H-alpha imaging survey of H I rich S0 and S0/a galaxies are presented. Analysis of CCD H-alpha interference-filter images of 16 galaxies is reported. Eight of these galaxies show evidence for ongoing star formation, one has nuclear emission but no H II regions, and the remaining seven have no emission detected with well-defined upper limits. A few of the galaxies with H II regions exhibit global peculiarities, while the others have essentially normal appearances. In the peculiar galaxies, the emission from H II regions appears pervasive, while in the apparently normal galaxies the H II regions are either organized into inner-disk rings or randomly distributed throughout the disk. A few of the galaxies are found to be clearly not S0s, or peculiar objects atypical of the S0 class. Using simple models, star-formation rates are derived from the observed H-alpha fluxes, and an estimate of gas-depletion time scales is made. 80 references

  13. KPNO 0.9m H(alpha) Imaging Survey of ``Transforming Galaxies'' in Local Galaxy Groups

    Science.gov (United States)

    Haines, Christopher; O'Sullivan, Ewan; Raychaudhury, Somak; Egami, Eiichi; Campusano, Luis

    2012-08-01

    We propose to use the KPNO 0.9-m telescope to obtain panoramic H(alpha) imaging of ~135 galaxies in ten nearby galaxy groups (60- 80 Mpc) from the Complete Local-Volume Groups Sample (CLoGS). In rich clusters ram-pressure stripping has been shown to be very effective at removing the gas contents and quenching star formation in infalling spiral galaxies. It is much less clear how galaxies are affected by the much lower ram pressures found in galaxy groups, or if other environmental processes begin to dominate. Given that >50% of galaxies in the local volume reside in groups, it is vital that we gain new insights into which mechanisms drive the SFR-density relation in groups. The proposed H(alpha) imaging will allow us to resolve where star-formation is occurring in each galaxy. This can effectively discriminate between ram-pressure stripping characterized by truncated H(alpha) disks, the much gentler starvation mechanism which produces anemic spirals, and nuclear starbursts triggered by low-velocity encounters and mergers which should be most frequent in groups.

  14. KPNO 0.9m H(alpha) Imaging Survey of ``Transforming Galaxies" in Local Galaxy Groups

    Science.gov (United States)

    Haines, Christopher; O'Sullivan, Ewan; Raychaudhury, Somak; Gargiulo, Adriana; Campusano, Luis

    2012-02-01

    We propose to use the KPNO 0.9-m telescope to obtain panoramic H(alpha) imaging of ~200 galaxies in two nearby (32, 35 Mpc) galaxy groups NGC 4261 and NGC 5353 from the CLoGS local group survey. In rich clusters ram-pressure stripping has been shown to be very effective at removing the gas contents and quenching star formation in infalling spiral galaxies. It is much less clear how galaxies are affected by the much lower ram pressures found in galaxy groups, or if other environmental processes begin to dominate. Given that >50% of galaxies in the local volume reside in groups, it is vital we gain new insights into which mechanisms drive the SFR-density relation in groups. The proposed H(alpha) imaging will allow us to resolve where star-formation is occuring in each galaxy. This can effectively discriminate between ram-pressure stripping characterized by truncated H(alpha) disks, the much gentler starvation mechanism which produces anemic spirals, and nuclear star-bursts triggered by low-velocity encounters which should be most frequent in groups.

  15. Limits on the star formation rates of z > 2 damped $Ly\\alpha$ systems from $H\\alpha$ spectroscopy

    CERN Document Server

    Bunker, A J; Clements, D L; Williger, G M; Hewett, P C; Bunker, Andrew J.; Warren, Stephen J.; Williger, Gerard M.

    1998-01-01

    We present the results of a long-slit K-band spectroscopic search with CGS4 on UKIRT for H-alpha emission from the objects responsible for high-redshift (z > 2) damped Ly-alpha absorption systems. The objective was to measure the star-formation rates in these systems. However, no H-alpha emission was detected above our 3-sigma limits of f < 10E-19 W/m**2, corresponding to star formation rates < 10 M_sun/yr/h**2 (q_0=0.5). These upper limits are more meaningful than those from searches for Ly-alpha emission because the H-alpha line is unaffected by resonant scattering. For q_0=0.5 our limits are in conflict with the star formation rates predicted under the assumption that the high-z DLAs are the fully-formed galactic-disk counterparts of today's massive spiral galaxies. Deeper spectroscopy is needed to test this picture for q_0=0.0. A programme of NICMOS imaging observations currently underway, combined with VLT spectroscopy, will provide a detailed picture of the link between DLAs and young galaxies.

  16. The Wyoming Survey for H-alpha. I. Initial Results at z ~ 0.16 and 0.24

    CERN Document Server

    Dale, Daniel A; Cohen, Seth A; Johnson, L Clifton; Kattner, ShiAnne M; Lamanna, Christine A; Moore, Carolynn A; Schuster, Micah D; Thatcher, Jacob W

    2008-01-01

    The Wyoming Survey for H-alpha, or WySH, is a large-area, ground-based, narrowband imaging survey for H-alpha-emitting galaxies over the latter half of the age of the Universe. The survey spans several square degrees in a set of fields of low Galactic cirrus emission. The observing program focuses on multiple dz~0.02 epochs from z~0.16 to z~0.81 down to a uniform (continuum+line) luminosity at each epoch of ~10^33 W uncorrected for extinction (3sigma for a 3" diameter aperture). First results are presented here for 98+208 galaxies observed over approximately 2 square degrees at redshifts z~0.16 and 0.24, including preliminary luminosity functions at these two epochs. These data clearly show an evolution with lookback time in the volume-averaged cosmic star formation rate. Integrals of Schechter fits to the extinction-corrected H-alpha luminosity functions indicate star formation rates per co-moving volume of 0.009 and 0.014 h_70 M_sun/yr/Mpc^3 at z~0.16 and 0.24, respectively. The formal uncertainties in the ...

  17. Stellar Populations and the Star Formation Histories of LSB Galaxies: I. Optical and H-alpha Imaging

    CERN Document Server

    Schombert, James; McGaugh, Stacy

    2011-01-01

    This paper presents optical and H-alpha imaging for a large sample of LSB galaxies selected from the PSS-II catalogs (Schombert et. al 1992). As noted in previous work, LSB galaxies span a range of luminosities (-10 > M_V > -20) and sizes (0.3 kpc < R_V25 < 10 kpc), although they are consistent in their irregular morphology. Their H-alpha luminosities (L(H-alpha) range from 10^36 to 10^41 ergs s^-1 (corresponding to a range in star formation, using canonical prescriptions, from 10^-5 to 1 M_solar yr^-1). Although their optical colors are at the extreme blue edge for galaxies, they are similar to the colors of dwarf galaxies (van Zee 2001) and gas-rich irregulars (Hunter & Elmegreen 2006). However, their star formation rates per unit stellar mass are a factor of ten less than other galaxies of the same baryonic mass, indicating that they are not simply quiescent versions of more active star forming galaxies. This paper presents the data, reduction techniques and new philosophy of data storage and pre...

  18. Evidence of Environmental Dependencies of Type Ia Supernovae from the Nearby Supernova Factory indicated by Local H{\\alpha}

    CERN Document Server

    Rigault, M; Aldering, G; Antilogus, P; Aragon, C; Bailey, S; Baltay, C; Bongard, S; Buton, C; Canto, A; Cellier-Holzem, F; Childress, M; Chotard, N; Fakhouri, H K; Feindt, U; Fleury, M; Gangler, E; Greskovic, P; Guy, J; Kim, A G; Kowalski, M; Lombardo, S; Nordin, J; Nugent, P; Pain, R; Pécontal, E; Pereira, R; Perlmutter, S; Rabinowitz, D; Runge, K; Saunders, C; Scalzo, R; Smadja, G; Tao, C; Thomas, R C; Weaver, B A

    2013-01-01

    (Abridged) We study the host galaxy regions in close proximity to Type Ia supernovae (SNe Ia) to analyze relations between the properties of SN Ia events and environments most similar to where their progenitors formed. We focus on local H\\alpha\\ emission as an indicator of young environments. The Nearby Supernova Factory has obtained flux-calibrated spectral timeseries for SNe Ia using integral field spectroscopy, allowing the simultaneous measurement of the SN and its immediate vicinity. For 89 SNe Ia we measure H\\alpha\\ emission tracing ongoing star formation within a 1 kpc radius around each SN. This constitutes the first direct study of the local environment for a large sample of SNe Ia also having accurate luminosity, color and stretch measurements. We find that SNe Ia with local H\\alpha\\ emission are redder by 0.036+/-0.017 mag, and that the previously-noted correlation between stretch and host mass is entirely driven by the SNe Ia coming from passive regions. Most importantly, the mean standardized bri...

  19. Integral Field Spectroscopy based H\\alpha\\ sizes of local Luminous and Ultraluminous Infrared Galaxies. A Direct Comparison with high-z Massive Star Forming Galaxies

    CERN Document Server

    Arribas, S; Alonso-Herrero, A; Rosales-Ortega, F F; Monreal-Ibero, A; García-Marín, M; García-Burillo, S; Rodríguez-Zaurín, J

    2012-01-01

    Aims. We study the analogy between local U/LIRGs and high-z massive SFGs by comparing basic H{\\alpha} structural characteristics, like size, luminosity and Star Formation Rate (SFR) surface density, in an homogeneous way (i.e. same tracer and size definition, similar physical scales). Methods. We use Integral Field Spectroscopy based H{\\alpha} emission maps for a representative sample of 54 local U/LIRGs (66 galaxies). From this initial sample we select 26 objects with H{\\alpha} luminosities (L(H{\\alpha})) similar to those of massive (i.e. M\\ast \\sim 10^10 M\\odot or larger) SFGs at z \\sim 2, and probing similar physical scales. Results. The sizes of the H{\\alpha} emitting region in the sample of local U/LIRGs span a large range, with r1/2(H{\\alpha}) from 0.2 to 7 kpc. However, about 2/3 of local U/LIRGs with Lir > 10^11.4 L\\odot have compact H{\\alpha} emission (i.e. r1/2 2 kpc). These are systems showing pre-coalescence merger activity and they are indistinguishable from the massive high-z SFGs galaxies in t...

  20. A surprise at the bottom of the main sequence: Rapid rotation and NO H-alpha emission

    Science.gov (United States)

    Basri, Gibor; Marcy, Geoffrey W.

    1995-02-01

    We report Kech Observatory high-resolution echelle spectra from 640-850 nm for eight stars near the faint end of the main sequence. These spectra are the highest resolution spectra of such late-type stars, and clearly resolve the TiO, VO, and atomic lines. The sample includes the field brown-dwarf candidate, BRI 0021-0214 (M9.5+). Very unexpectedly, it shows the most rapid rotation in the entire samples, v sin i approximately 40 km/s, which is 20x faster than typical field nonemission M stars. Equally surprising is that BRI 0021 exhibits no emission or absorptionat H-alpha. We argue that this absence is not simply due to its cool photosphere, but that stellar activity declines in a fundamental way at the end of the main sequence. As it is the first very late M dwarf observed at high spectral resolution, BRI 0021 may be signaling a qualitative change in the angular momentum loss rate among the lowest mass stars. Conventionally, its rapid rotation would have marked BRI 0021 as very young, consistent with the selection effect which arises if the latest-type dwarfs are really brown dwarfs on cooling curves. In any case, it is unprecedented to find no sign of stellar activity in such a rapidly rotating convective star. We also discuss the possible conflict between this observation and the extremely strong H-alpha seen in another very cool star, PC 0025+0447. Extrapolation of M-L relations for BRI 0021 yields M approximately 0.065 solar mass, and the other sample objects have expected masses near the H-burning limit. These include two Pleiades brown-dwarf candidates, four field M6 dwarfs and one late-type T Tauri star. The two Pleiades M6 dwarfs have v sin i of 26 and 37 km/s, H-alpha in emission, and radial velocities consistent with Pleiades M6 dwarfs have v sin i of 26 and 37 km/s, H-alpha in emission, and radial velocities consistent with Pleiades membership. Similarly, the late-type T Tauri star has v sin i approximately 30 km/s and H alpha emission indicate of its youth. Two of the four late-type field dMe star also exhibit rotation above 5 km/s, consistent with expectations. BRI 0021 has no measurable absoprtion due to lithium, indicating that it is likely to be more massive than 0.065 solar mass.

  1. Obscured star formation at z = 0.84 with HiZELS: the relationship between star formation rate and H-alpha or ultra-violet dust extinction

    OpenAIRE

    Garn, Timothy; Sobral, David; Best, Philip N.; Geach, James E.; Smail, Ian; Cirasuolo, Michele; Dalton, Gavin B.; Dunlop, James S.; Mclure, Ross J.; Farrah, Duncan

    2009-01-01

    [Abridged] We compare H-alpha, ultraviolet (UV) and infrared (IR) indicators of star formation rate (SFR) for a sample of z = 0.84 galaxies from the High-z Emission Line Survey (HiZELS). Using multi-wavelength diagnostics, we estimate that 5 - 11 per cent of H-alpha emitters at this redshift are active galactic nuclei. We detect 35 per cent of the H-alpha emitters individually at 24 microns, and stack the star-forming emitters on deep 24-micron images in order to calculate t...

  2. Sub-THz and H{\\alpha} activity during the preflare and main phases of a GOES class M2 event

    CERN Document Server

    Kaufmann, Pierre; de Castro, C Guillermo Giménez; White, Stephen M; Raulin, Jean-Pierre; Correia, Emilia; Fernandes, Luis Olavo; de Souza, Rodney V; Godoy, Rodolfo; Marun, Adolfo; Pereyra, Pablo

    2011-01-01

    Radio and optical observations of the evolution of flare-associated phenomena have shown an initial and rapid burst at 0.4 THz only followed subsequently by a localized chromospheric heating producing an H{\\alpha} brightening with later heating of the whole active region. A major instability occurred several minutes later producing one impulsive burst at microwaves only, associated with an M2.0 GOES X-ray flare that exhibited the main H{\\alpha} brightening at the same site as the first flash. The possible association between long-enduring time profiles at soft X-rays, microwaves, H{\\alpha} and sub-THz wavelengths is discussed. In the decay phase the H{\\alpha} movie shows a disrupting magnetic arch structure ejecting dark, presumably chromospheric, material upwards. The time sequence of events suggests genuine interdependent and possibly non-thermal instabilities triggering phenomena, with concurrent active region plasma heating and material ejection.

  3. SUB-THz AND H{alpha} ACTIVITY DURING THE PREFLARE AND MAIN PHASES OF A GOES CLASS M2 EVENT

    Energy Technology Data Exchange (ETDEWEB)

    Kaufmann, Pierre; Gimenez de Castro, C. Guillermo; Raulin, Jean-Pierre; Correia, Emilia; Fernandes, Luis Olavo; De Souza, Rodney V. [CRAAM, Escola de Engenharia, Universidade Presbiteriana Mackenzie, Sao Paulo (Brazil); Marcon, Rogerio [IFGW, Universidade Estadual de Campinas (Brazil); White, Stephen M. [AFRL, Space Vehicles Directorate, Albuquerque, NM (United States); Godoy, Rodolfo; Marun, Adolfo; Pereyra, Pablo [Complejo Astronomico El Leoncito, CONICET, San Juan (Argentina)

    2011-12-01

    Radio and optical observations of the evolution of flare-associated phenomena have shown an initial and rapid burst at 0.4 THz only followed subsequently by a localized chromospheric heating producing an H{alpha} brightening with later heating of the whole active region. A major instability occurred several minutes later producing one impulsive burst at microwaves only, associated with an M2.0 GOES X-ray flare that exhibited the main H{alpha} brightening at the same site as the first flash.The possible association between long-enduring time profiles at soft X-rays, microwaves, H{alpha}, and sub-THz wavelengths is discussed. In the decay phase, the H{alpha} movie shows a disrupting magnetic arch structure ejecting dark, presumably chromospheric, material upward. The time sequence of events suggests genuine interdependent and possibly non-thermal instabilities triggering phenomena, with concurrent active region plasma heating and material ejection.

  4. Gyrokinetic equivalence

    International Nuclear Information System (INIS)

    We compare two different derivations of the gyrokinetic equation: the Hamiltonian approach in Dubin D H E et al (1983 Phys. Fluids 26 3524) and the recursive methodology in Parra F I and Catto P J (2008 Plasma Phys. Control. Fusion 50 065014). We prove that both approaches yield the same result at least to second order in a Larmor radius over macroscopic length expansion. There are subtle differences in the definitions of some of the functions that need to be taken into account to prove the equivalence.

  5. Tree-width for first order formulae

    CERN Document Server

    Adler, Isolde

    2012-01-01

    We introduce tree-width for first order formulae phi, fotw(phi). We show that computing fotw is fixed-parameter tractable with parameter fotw. Moreover, we show that on classes of formulae of bounded fotw, model checking is fixed parameter tractable, with parameter the length of the formula. This is done by translating a formula phi with fotw(phi)equivalent to an L^k formula is undecidable. In contrast, the classes of first order formulae with bounded fotw are fragments of first order logic for which the equivalence is decidable. Our notion of tree-width generalises tree-width of conjunctive queries to arbitrary formulae of first order logic by taking into account the quantifier interaction in a formula. Moreover, it is more powerful than the notion of elimination-width of quantified constraint formulae, defined by Chen and Dalmau (CSL 2005): for quantified constraint form...

  6. H(alpha) Proxies for EIT Crinkles: Further Evidence for Preflare "Breakout"-Type Activity in an Ejective Solar Eruption

    Science.gov (United States)

    Sterling, Alphonse C.; Qiu, Jiong; Wang, Haimin; Moore, Ronald L.

    2001-01-01

    We present H(alpha) observations from Big Bear Solar Observatory of an eruptive flare in NOAA Active Region 8210, occurring near 22:30 UT on 1998 May 1. Previously, using the Extreme Ultraviolet Imaging Telescope (EIT) on the Solar and Heliospheric Observatory (SOHO) spacecraft, we found that a pattern of transient, localized brightenings, which we call 'EIT crinkles,' appears in the neighborhood of the eruption near the time of flare onset. These EIT crinkles occur at a location in the active region well separated from the sheared core magnetic fields, which is where the most intense features of the eruption are concentrated. We also previously found that high-cadence images from the Soft X-ray Telescope (SXT) on Yohkoh indicate that soft X-ray intensity enhancements in the core begin after the start of the EIT crinkles. With the H(alpha) data, we find remote flare brightening counterparts to the EIT crinkles. Light curves as functions of time of various areas of the active region show that several of the remote flare brightenings undergo intensity increases prior to the onset of principal brightenings in the core region, consistent with our earlier findings from EIT and SXT data. These timing relationships are consistent with the eruption onset mechanism known as the breakout model, introduced by Antiochos and colleagues, which proposes that eruptions begin with reconnection at a magnetic null high above the core region. Our observations are also consistent with other proposed mechanisms that do not involve early reconnection in the core region. As a corollary, our observations are not consistent with the so-called tether-cutting models, which say that the eruption begins with reconnection in the core. The H(alpha) data further show that a filament in the core region becomes activated near the time of EIT crinkle onset, but little if any of the filament actually erupts, despite the presence of a halo coronal mass ejection (CME) associated with this event.

  7. Scattering polarization and the Hanle effect in H-alpha as a probe of chromospheric magnetism: Modeling vs. Observations

    CERN Document Server

    Stepan, Jiri; Ramelli, Renzo; Bianda, Michele

    2011-01-01

    The Hanle effect in strong spectral lines is the physical mechanism that should be increasingly exploited for quantitative explorations of the magnetism of the quiet solar chromospheric plasma. Here we show, by means of multilevel radiative transfer calculations and new spectropolarimetric observations, that the amplitude and shape of the scattering polarization profiles of the H-alpha line is very sensitive to the strength and structure of the chromospheric magnetic field. The interpretation of the observations in terms of one-dimensional radiative transfer modeling suggests that there is an abrupt magnetization in the upper chromosphere of the quiet Sun.

  8. SBS 0335-052 E and W: implications of new broad-band and H-alpha photometry

    OpenAIRE

    Pustilnik, S. A.; Pramskij, A. G.; Kniazev, A. Y.

    2004-01-01

    We present the results of deep multicolour CCD imaging with the 6-m telescope of the pair of extremely metal-deficient gas-rich dwarf galaxies SBS 0335-052 E and W. The total magnitudes in U,B,V,R,I bands and the integrated fluxes of H-alpha emission are measured for both galaxies, and their integrated colours are derived. The analysis of their surface brightness (SB) distributions is performed with the use of the azimuthally-averaged SB profiles. The latter were modeled by ...

  9. Resonances and resonance widths

    International Nuclear Information System (INIS)

    Two-dimensional betatron resonances are much more important than their simple one-dimensional counterparts and exhibit a strong dependence on the betatron phase advance per cell. A practical definition of ''width'' is expanded upon in order to display these relations in tables. A primarily pedagogical introduction is given to explain the tables, and also to encourage a wider capability for deriving resonance behavior and wider use of ''designer'' resonances

  10. The $H\\alpha$ Luminosity Function and Global Star Formation Rate From Redshifts of One to Two

    CERN Document Server

    Yan, L; Freudling, W; Teplitz, H I; Malumuth, E M; Weymann, R J; Malkan, M A; Yan, Lin; Carthy, Patrick J. Mc; Freudling, Wolfram; Teplitz, Harry I.; Malumuth, Eliot M.; Weymann, Ray J.; Malkan, Matthew A.

    1999-01-01

    We present a luminosity function for H$\\alpha$ emission from galaxies at redshifts between 0.7 and 1.9 based on slitless spectroscopy with NICMOS on HST. The luminosity function is well fit by a Schechter function over the range $6 \\times 10^{41} < L(H\\alpha) < 2 \\times 10^{43} erg/sec$ with $L^* = 7 \\times 10^{42} erg/sec$ and $\\phi^* = 1.7 \\times 10^{-3} Mpc^{-3}$ for $H_0=50 km/s Mpc^{-1}$ and $q_0=0.5$. We derive a volume averaged star formation rate at $z = 1.3 \\pm 0.5$ of 0.13 M_{ødot} yr^{-1} Mpc^{-3} without correction for extinction. The SFR that we derive at $\\sim 6500 \\AA is a factor of 3 higher than that deduced from 2800 \\AA continua. If this difference is due entirely to reddening, the extinction correction at 2800 \\AA is quite significant. The precise magnitude of the total extinction correction at rest-frame UV wavelengths (e.g. 2800 \\AA and 1500 \\AA) is sensitive to the relative spatial distribution of the stars, gas and dust, as well as on the extinction law. In the extreme case of a ...

  11. Using MHD simulations to model H-alpha and UV spectral lines for interpretation of IRIS and NST data

    CERN Document Server

    Sadykov, Viacheslav M

    2014-01-01

    We present results of non-LTE modeling of H-alpha 6563 A and Mg II k&h 2796 A and 2803 A lines. This modeling is important for interpretation of coordinated observations from the recently launched NASA's IRIS mission and from the New Solar Telescope at Big Bear Solar Observatory. Among available codes for the non-LTE modeling, the RH code is chosen as the most appropriate for modeling of the line profiles. The most suitable Hydrogen and Magnesium atomic models are selected by performing several tests of the code. The influence of the ionization degree on the line profiles is also studied. Radiative-MHD simulations of the solar atmosphere, obtained with the Bifrost code, are used as input data for calculation of synthetic spectra of the H-alpha and Mg II h&k lines for particular locations evolving with time. The spectral line variations reveal the presence of MHD waves in the simulation results. We construct oscillation power spectra of the line intensity for different wavelength, and compare these wit...

  12. Star Formation Rates and Stellar Masses of H-alpha Selected Star-Forming Galaxies at z=0.84: A Quantification of the Downsizing

    CERN Document Server

    Villar, V; Pérez-González, P-G; Barro, G; Zamorano, J; Noeske, K G; Koo, D C

    2011-01-01

    In this work we analyze the physical properties of a sample of 153 star forming galaxies at z~0.84, selected by their H-alpha flux with a NB filter. B-band luminosities of the objects are higher than those of local star forming galaxies. Most of the galaxies are located in the blue cloud, though some objects are detected in the green valley and in the red sequence. After the extinction correction is applied virtually all these red galaxies move to the blue sequence, unveiling their dusty nature. A check on the extinction law reveals that the typical extinction law for local starbursts is well suited for our sample but with E(B-V)_stars=0.55 E(B-V)_gas. We compare star formation rates (SFR) measured with different tracers (H-alpha, UV and IR) finding that they agree within a factor of three after extinction correction. We find a correlation between the ratios SFR_FUV/SFR_H-alpha, SFR_IR/SFR_H-alpha and the EW(H-alpha) (i.e. weighted age) which accounts for part of the scatter. We obtain stellar mass estimation...

  13. Virtual 5 mm-width multileaf collimation

    International Nuclear Information System (INIS)

    Purpose/Objective: The use of multileaf collimators (MLC) in place of standard cerrobend blocks has many advantages in static radiotherapy treatments. However, limitations still exist due to the increased effective penumbra and stepped isodose lines produced by conventional MLC, which may not be acceptable in certain clinical situations. These limitations are mainly attributed to the 1 cm leaf widths currently available on commercial MLC. We have implemented a virtual 5 mm-width MLC technique in an attempt to improve these limitations. Materials and Methods: Using the MLC on a Varian 2100C linear accelerator in clinical use, dose distributions were obtained with film dosimetry for 6 and 18 MV photon beams in a water phantom system over a range of block orientations at different depths for conventional MLC, virtual 5 mm-width MLC and cerrobend blocks. The MLC leaf widths on this system are 1 cm at the isocentre. The virtual 5 mm-width MLC technique uses two superimposed MLC fields to irradiate a field. The first field is the standard MLC field with the collimator centre aligned with the field centre. The other MLC field has the centre of the collimator shifted away from the field centre by 5 mm in the direction perpendicular to the leaf movement direction. The composite of these two MLC fields is equivalent to that of a 5 mm-leaf-width MLC. Results: The virtual 5 mm-width MLC resulted in an improvement of the effective penumbra by approximately 1 mm. A more significant by approximately 1 mm. A more significant effect was found with the 'peak' to 'trough' distances of specified isodose lines which reflects the 'smoothness' of an isodose line. This effect was most pronounced when maximal stepped isodose lines (ie. 45 degree block orientation) occurred. A much smoother field edge was obtained with this technique as compared to conventional MLC. 'Peak' to 'trough' distances were measured to be as great as 4 to 5 mm using conventional MLC blocks, whereas the corresponding 'peak' to 'trough' distances with virtual 5 mm-width MLC were 1 mm or less. This was comparable to the distances measured with cerrobend blocks of 0.5 mm or less. Conclusion: We have demonstrated a method of improving the dose distribution of MLC fields using a virtual 5 mm-width MLC technique. The effective penumbra can be decreased and the stepped isodose lines can be virtually eliminated. This would allow MLC to be used more frequently in place of cerrobend blocks especially when the MLC blocks are near critical normal structures. We have implemented this technique in our clinic and our preliminary experience has found it to be a practical approach

  14. A study of H-alpha velocities in NGC 1499, NGC 7000, and IC 1318B/C

    Science.gov (United States)

    Fountain, W. F.; Gary, G. A.; Odell, C. R.

    1983-01-01

    Multiple slit echelle spectrograph observations of the H-alpha emission line are used to map the radial velocities of the California Nebula (NGC 1499), the North American Nebula complex (NGC 7000 and IC 5070), and IC 1318B/C. The California Nebula is singularly constant in velocity, considering its geometry. The North American Nebula complex reflects a very simple, classical dynamical picture. The expansion discovered earlier in IC 1318B/C is confirmed, detailed, and the model refined. The new data, along with that in earlier papers of this series, show that stellar wind acceleration and champagne flow mechanisms both play important roles in determining the evolution of H II regions.

  15. A test of arm-induced star formation in spiral galaxies from near-IR and H$\\alpha$ imaging

    CERN Document Server

    Seigar, M S; Seigar, Marc S.; James, Phil A.

    2002-01-01

    We have imaged a sample of 20 spiral galaxies in H$\\alpha$ and in the near-infrared K band (2.2 um), in order to determine the location and strength of star formation in these objects with respect to perturbations in the old stellar population. We have found that star formation rates are significantly enhanced in the vicinity of K band arms. We have also found that this enhancement in star formation rate in arm regions correlates well with a quantity that measures the relative strengths of shocks in arms. Assuming that the K band light is dominated by emission from the old stellar population, this shows that density waves trigger star formation in the vicinity of spiral arms.

  16. H-alpha solar flare activity in Bou 2030 and 2032, SERF interval, October 6-8, 1979

    International Nuclear Information System (INIS)

    During the SERF interval of the SMY, October 4 to 9, 1979, the observations of regions Bou 2030 and 2032 were coordinated. An analysis of H-alpha observations indicates that, contrary to expectations, flares initiated in the magnetically simpler sunspot group Bou 2030 (Hale 16 341) occurred north off Bou 2032. The enhanced occurrence of flares in Bou 2030 on October 6, 1979 was located in an area with pronounced changes in polarity and structure of the background field in the neighbourhood of Bou 2030. The new positive large-scale field interacted with the negative field of the following spot B. Emission flare structures developed homologously along the new neutral line of the large-scale field. In analysing the pre-flare situation in a particular active region, it is therefore also necessary to know the characteristics of the large-scale field. (author)

  17. Protoplanetary Disks in the Orion Nebula An H$\\alpha$ Fabry-Perot study and Astrobiological Aspects

    CERN Document Server

    De la Fuente-Acosta, E; Arias, L; Throop, H B; Ambrocio-Cruz, P; Fuente, Eduardo de la; Rosado, Margarita; Arias, Lorena; Throop, Patricia Ambrocio-Cruz & Henry B.

    2002-01-01

    In this paper, we present a briefly overview of the protoplanetary disks in the Orion Nebula, incluiding some astrobiological aspects and an H$\\alpha$ Fabry-Perot study of 16 of them. We found that Fabry-Perot interferometry constitutes an effective technique for the detection of proplyds. We also report heliocentric systemic velocities for the proplyds 82-336, 158-323, 158-326, 159-350, 161-314, 161-324, 163-317, 166-316, 167-317, 168-326, 170-337, 176-325, 177-341, 180-331, 197-427 and 244-440. The velocities were measured between 22-38 km s$^{-1}$.

  18. Hydrogen H$\\alpha$ line polarization in solar flares. Theoretical investigation of atomic polarization by proton beams considering self-consistent NLTE polarized radiative transfer

    CERN Document Server

    Stepan, J; Sahal-Bréchot, S; Stepan, Jiri; Heinzel, Petr; Sahal-Brechot, Sylvie

    2007-01-01

    Context. We present a theoretical review of the effect of impact polarization of a hydrogen H$\\alpha$ line due to an expected proton beam bombardment in solar flares. Aims. Several observations indicate the presence of the linear polarization of the hydrogen H$\\alpha$ line observed near the solar limb above 5% and preferentially in the radial direction. We theoretically review the problem of deceleration of the beam originating in the coronal reconnection site due to its interaction with the chromospheric plasma, and describe the formalism of the density matrix used in our description of the atomic processes and the treatment of collisional rates. Methods. We solve the self-consistent NLTE radiation transfer problem for the particular semiempirical chromosphere models for both intensity and linear polarization components of the radiation field. Results. In contrast to recent calculations, our results show that the energy distribution of the proton beam at H$\\alpha$ formation levels and depolarizing collisions...

  19. Width of nonlinear resonance

    International Nuclear Information System (INIS)

    Two approximations are made, one essential and the other not so essential but convenient to keep the analytical treatment manageable: (1) Only one nonlinear resonance is considered at a time so that the treatment is best suited when the tune is close to one resonance only. To improve this approximation, one must go to the next order which involves a canonical transformation of dynamical variables. Analytical treatment of more than one resonance is not possible for general cases. (2) In the formalism using the action-angle variables, the Hamiltonian can have terms which are independent of the angle variables. These terms are called phase-independent terms or shear terms. The tune is then a function of the oscillation amplitudes. In the lowest-order treatment, the (4N)-pole components but not the (4N + 2)-pole components contribute to this dependence. In deriving the resonance width analytically, one ignores these terms in the Hamiltonian for the sake of simplicity. If these are retained, one needs at least three extra parameters and the analytical treatment becomes rather unwieldy

  20. Discovery of an Apparent Nova in M81 and H-alpha Confirmation of PNV J09560160+6903126 and PNV J09553945+6905557

    Science.gov (United States)

    Hornoch, K.; Stoev, H.; Tudor, V.; Vaduvescu, O.; Frigo, M.

    2014-05-01

    We report the discovery of an apparent nova in M81 galaxy on a co-added 2000-s narrow-band H-alpha CCD image taken with the 2.5-m Isaac Newton Telescope (INT) + WFC at La Palma under ~1.2" seeing on 2014 May 26.923 UT. ...

  1. A Spectacular H$\\alpha$ Complex in Virgo: Evidence for a Collision Between M86 and NGC 4438 and Implications for Collisional ISM Heating of Ellipticals

    CERN Document Server

    Kenney, J D P; Crowl, H H; Feldmeier, J; Jacoby, G H

    2008-01-01

    Deep wide-field H$\\alpha$+[NII] imaging around the Virgo cluster giant elliptical galaxy M86 reveals a highly complex and disturbed ISM/ICM. The most striking feature is a set of H$\\alpha$ filaments which clearly connect M86 with the nearby disturbed spiral NGC 4438 (23$'$=120 kpc projected away), providing strong evidence for a previously unrecognized collision between them. Spectroscopy of selected regions show a fairly smooth velocity gradient between M86 and NGC 4438, consistent with the collision scenario. Such a collision would impart significant energy into the ISM of M86, probably heating the gas and acting to prevent the gas from cooling to form stars. We propose that cool gas stripped from NGC 4438 during the collision and deposited in its wake is heated by shocks, ram pressure drag, or thermal conduction, producing most of the H$\\alpha$ filaments. Some H$\\alpha$ filaments are associated with the well-known ridge of bright X-ray emission to the NW of the nucleus, suggesting that the collision is res...

  2. HiZELS: a high redshift survey of H-alpha emitters. I: the cosmic star-formation rate and clustering at z=2.23

    CERN Document Server

    Geach, J E; Best, P N; Kurk, J; Casali, M; Ivison, R J; Coppin, K

    2008-01-01

    We present results from a near-infrared narrow-band survey of emission-line galaxies at z=2.23, using the Wide Field Camera on the United Kingdom Infrared Telescope. The H2S1 narrow-band filter (lambda_c=2.121um) we employ selects the H-alpha emission line redshifted to z=2.23, and is thus suitable for selecting 'typical' star forming galaxies and active galactic nuclei at this epoch. The pilot study was undertaken in the well studied Cosmological Evolution Survey field (COSMOS) and is already the largest near-infrared narrow-band survey at this depth, with a line flux limit of F(H-alpha)~10^-16 erg/s/cm^2 over 0.60 square degrees, probing ~220x10^3 Mpc^3 (co-moving) down to a limiting star formation rate of 30 M_sun/yr (3sigma). In this paper we present the results from our pilot survey and evaluate the H-alpha luminosity function and estimate the clustering properties of H-alpha emitters at z=2.23 from 55 detected galaxies. The integrated luminosity function is used to estimate the volume averaged star form...

  3. Obscured star formation at z = 0.84 with HiZELS: the relationship between star formation rate and H-alpha or ultra-violet dust extinction

    CERN Document Server

    Garn, Timothy; Best, Philip N; Geach, James E; Smail, Ian; Cirasuolo, Michele; Dalton, Gavin B; Dunlop, James S; McLure, Ross J; Farrah, Duncan

    2009-01-01

    [Abridged] We compare H-alpha, ultraviolet (UV) and infrared (IR) indicators of star formation rate (SFR) for a sample of z = 0.84 galaxies from the High-z Emission Line Survey (HiZELS). Using multi-wavelength diagnostics, we estimate that 5 - 11 per cent of H-alpha emitters at this redshift are active galactic nuclei. We detect 35 per cent of the H-alpha emitters individually at 24 microns, and stack the star-forming emitters on deep 24-micron images in order to calculate the typical SFRs of our galaxies. These are compared to the observed H-alpha line fluxes in order to estimate the extinction at z = 0.84, and we find a significant increase in dust extinction for galaxies with higher SFRs. We demonstrate that the local relationship between SFR and extinction is suitable for our sample, and attribute the overall increase in dust extinction for z = 0.84 galaxies to an increase in the average SFR, rather than to a change in dust properties. We calculate the UV extinction, and find a similar dependence on SFR, ...

  4. HiZELS: a high redshift survey of H-alpha emitters. II: the nature of star-forming galaxies at z=0.84

    CERN Document Server

    Sobral, D; Geach, J E; Smail, Ian; Kurk, J; Cirasuolo, M; Casali, M; Ivison, R J; Coppin, K; Dalton, G B

    2009-01-01

    New results from a large survey of H-alpha emission-line galaxies at z=0.84 using WFCAM/UKIRT and a custom narrow-band filter in the J band are presented as part of the HiZELS survey. Reaching an effective flux limit of 1e-16 erg/s/cm^2 in a comoving volume of 1.8e5 Mpc^3, this represents the largest and deepest survey of its kind ever done at z~1. There are 1517 potential line emitters detected across 1.4 sq.deg of the COSMOS and UKIDSS UDS fields, of which 743 are selected as H-alpha emitters. These are used to calculate the H-alpha luminosity function, which is well-fitted by a Schechter function with phi*=10^(-1.92+-0.10) Mpc^-3, L*=10^(42.26+-0.05)erg/s, and alpha=-1.65+-0.15. The integrated star formation rate density (SFRD) at z=0.845 is 0.15+-0.01 M_sun/yr/Mpc^3. The results robustly confirm a strong evolution of SFRD from the present day out to z~1 and then flattening to z~2, using a single star-formation indicator. Out to z~1, both the characteristic luminosity and space density of the H-alpha emitt...

  5. The role of cluster mergers and travelling shocks in shaping the H$\\alpha$ luminosity function at $\\bf z\\sim0.2$: `sausage' and `toothbrush' clusters

    CERN Document Server

    Stroe, Andra; Röttgering, Huub J A; van Weeren, Reinout J

    2013-01-01

    The most extreme cluster mergers can lead to massive cluster-wide travelling shock waves. The CIZA J2242.8+5301 ('sausage') and 1RXS J0603.3+4213 (`toothbrush') clusters ($z\\sim0.2$) host enormous radio-emitting shocks with simple geometry. We investigate the role of mergers and shocks in shaping the H$\\alpha$ luminosity function, using custom-made narrow-band filters matching the cluster redshifts mounted on the INT. We surveyed $\\sim0.28$ deg$^2$ for each cluster and found $181$ line emitters in the `sausage' (volume of $3.371\\times10^3$ Mpc$^3$ for H$\\alpha$ at $z=0.1945$) and $141$ in the `toothbrush' ($4.546\\times10^3$ Mpc$^3$ for H$\\alpha$ at $z=0.225$), out of which $49$ (`sausage') and $30$ (`toothbrush') are expected to be H$\\alpha$. We build luminosity functions for the field-of-view down to an average limiting star formation rate of $0.14$ M$_{\\odot}$ yr$^{-1}$, find good agreement with field luminosity functions at $z=0.2$, but significant differences between the shapes of the luminosity functions...

  6. Galaxy interactions and star formation: Results of a survey of global H-alpha emission in spiral galaxies in 8 clusters

    International Nuclear Information System (INIS)

    Kennicutt and Kent (1983) have shown that the global H alpha emission from a spiral galaxy is an indicator of the formation rate of massive stars. Moss, Whittle and Irwin (1988) have surveyed two clusters (Abell 347 and 1367) for galaxies with H alpha emission using a high dispersion objective prism technique. The purpose of the survey is to investigate environmental effects on star formation in spiral galaxies, and in particular to ascertain whether star formation is enhanced in cluster spirals. Approximately 20 percent of CGCG galaxies were detected in emission. Two plates of excellent quality were obtained for each of the two clusters. The results of this survey have been discussed by Moss (1987). The detected galaxies are of types SO-a and later. The frequency with which galaxies are detected in emission increases towards later morphological type as expected (cf. Kennicutt and Kent 1983). There is no evidence of any dependence of the frequency of detected emission on the absolute magnitude of the galaxy (cf. Moss and Whittle 1990), but there is a strong correlation between a disturbed morphological appearance of the galaxy and the detection of emission. Furthermore it is found that the emission is more centrally concentrated in those galaxies which show a disturbed morphology. It may be noted that the objective prism plate gives a spectrum of a 400 A region around rest wavelength H alpha, but superposed on this is the H alpha emission from the galaxy which, becauspha emission from the galaxy which, because the light is essentially monochromatic, results in a true two-dimensional image of the H alpha distribution

  7. The extended H-alpha emitting filaments surrounding NGC4696, the central galaxy of the Centaurus cluster

    CERN Document Server

    Crawford, C S; Fabian, A C; Sanders, J S

    2005-01-01

    We present images of NGC4696, the central galaxy in the Centaurus cluster, showing the large extent of cool filaments which are bright in H-alpha line emission. These filaments share the detailed structure of both the central dust lane and the inner regions of the arc-like plumes seen in soft X-ray emission. The X-ray gas is at its coolest, and most absorbed in this same region. The smoothness of the features implies that the local environment is not strongly turbulent. We suggest that these filaments are either shaped by confinement due to a strong magnetic field, or by bulk flows within the intracluster medium. We propose that like similar filamentary systems in the core of clusters, these cooler components have been drawn out of the central galaxy behind buoyant gas bubbles from previous episodes of radio activity. We find a spur of low-frequency radio emission leading to a region of low X-ray pressure within the intracluster medium supporting this interpretation.

  8. ESO-H$\\alpha$~574 and Par-Lup3-4 Jets: Exploring the spectral, kinematical and physical properties

    CERN Document Server

    Whelan, E T; Antoniucci, S; Alcalá, J M; Giannini, T; Nisini, B; Bacciotti, F; Podio, L; Stelzer, B; Comerón, F

    2014-01-01

    In this paper a comprehensive analysis of VLT / X-Shooter observations of two jet systems, namely ESO-H$\\alpha$ 574 a K8 classical T Tauri star and Par-Lup 3-4 a very low mass (0.13~\\Msun) M5 star, is presented. Both stars are known to have near-edge on accretion disks. A summary of these first X-shooter observations of jets was given in a 2011 letter. The new results outlined here include flux tables of identified emission lines, information on the morphology, kinematics and physical conditions of both jets and, updated estimates of $\\dot{M}_{out}$ / $\\dot{M}_{acc}$. Asymmetries in the \\eso flow are investigated while the \\para jet is much more symmetric. The density, temperature, and therefore origin of the gas traced by the Balmer lines are investigated from the Balmer decrements and results suggest an origin in a jet for \\eso while for \\para the temperature and density are consistent with an accretion flow. $\\dot{M}_{acc}$ is estimated from the luminosity of various accretion tracers. For both targets, ne...

  9. Short timescale variations of the H{\\alpha} double-peaked profile of the nucleus of NGC 1097

    CERN Document Server

    Schimoia, Jaderson S; Nemmen, Rodrigo S; Winge, Cláudia; Eracleous, Michael; 10.1088/0004-637X/748/2/145

    2012-01-01

    The broad (FWHM ~ 10,000 km/s) double-peaked H{\\alpha} profile from the LINER/Seyfert 1 nucleus of NGC 1097 was discovered in 1991, and monitored for the following 11 years. The profile showed variations attributed to the rotation of gas in a non-axisymmetric Keplerian accretion disk, ionized by a varying radiatively inefficient accretion flow (RIAF) located in the inner parts of the disk. We present and model 11 new spectroscopic observations of the double-peaked profile taken between 2010 March and 2011 March. This series of observations was motivated by the finding that in 2010 March the flux in the double-peaked line was again strong, becoming, in 2010 December, even stronger than in the observations of a decade ago. We also discovered shorter timescale variations than in the previous observations: (1) the first, of ~7 days, is interpreted as due to "reverberation" of the variation of the ionizing source luminosity, and the timescale of 7 days as the light crossing time between the source and the accretio...

  10. Large-Amplitude Oscillation of an Erupting Filament as Seen in EUV, H-alpha and Microwave Observations

    CERN Document Server

    Isobe, H; Asai, A; Jain, R

    2007-01-01

    We present multiwavelength observations of a large-amplitude oscillation of a polar crown filament on 15 October 2002. The oscillation occurred during the slow rise (about 1 km/s) of the filament. It completed three cycles before sudden acceleration and eruption. The oscillation and following eruption were clearly seen in observations recorded by the Extreme-Ultraviolet Imaging Telescope onboard SOHO. The oscillation was seen only in a part of the filament, and it appears to be a standing oscillation rather than a propagating wave. The period of oscillation was about two hours and did not change significantly during the oscillation. We also identified the oscillation as a "winking filament" in the H-alpha images taken by the Flare Monitoring Telescope, and as a spatial displacement in 17 GHz microwave images from Nobeyama Radio Heliograph (NoRH). The filament oscillation seems to be triggered by magnetic reconnection between a filament barb and nearby emerging magnetic flux as was evident from the MDI magneto...

  11. Star formation at z=1.47 from HiZELS: An H{\\alpha}+[OII] double-blind study

    CERN Document Server

    Sobral, David; Matsuda, Yuichi; Smail, Ian; Geach, James; Cirasuolo, Michele

    2011-01-01

    This paper presents the results from the first wide and deep dual narrow-band survey to select H-alpha (Ha) and [OII] line emitters at z=1.47\\pm0.02 (using matched narrow-band filters in the H and z' bands), exploiting synergies between the UKIRT and Subaru telescopes. The Ha survey at z=1.47 reaches a flux limit of ~7x10^-17 erg/s/cm^2 and detects ~200 Ha emitters over 0.7deg^2, while the much deeper [OII] survey reaches an effective flux of ~7x10^-18 erg/s/cm^2, detecting ~1400 z=1.47 [OII] emitters in a matched co-moving volume of ~2.5x10^5 Mpc^3. The combined survey results in the identification of 190 simultaneous Ha and [OII] emitters at z=1.47. Ha and [OII] luminosity functions are derived and both are shown to evolve significantly from z~0 in a consistent way. The star formation rate density of the Universe at z=1.47 is evaluated, with the Ha analysis yielding 0.16\\pm0.05 M_sun/yr/Mpc^3 and the [OII] analysis 0.17\\pm0.04 M_sun/yr/Mpc^3. The measurements are combined with other studies, providing a sel...

  12. Tree-width and dimension

    OpenAIRE

    Joret, Gwenae?l; Micek, Piotr; Milans, Kevin G.; Trotter, William T.; Walczak, Bartosz; Wang, Ruidong

    2013-01-01

    Over the last 30 years, researchers have investigated connections between dimension for posets and planarity for graphs. Here we extend this line of research to the structural graph theory parameter tree-width by proving that the dimension of a finite poset is bounded in terms of its height and the tree-width of its cover graph.

  13. Probabilistic Analysis of Crack Width

    Directory of Open Access Journals (Sweden)

    J. Marková

    2000-01-01

    Full Text Available Probabilistic analysis of crack width of a reinforced concrete element is based on the formulas accepted in Eurocode 2 and European Model Code 90. Obtained values of reliability index b seem to be satisfactory for the reinforced concrete slab that fulfils requirements for the crack width specified in Eurocode 2. However, the reliability of the slab seems to be insufficient when the European Model Code 90 is considered; reliability index is less than recommended value 1.5 for serviceability limit states indicated in Eurocode 1. Analysis of sensitivity factors of basic variables enables to find out variables significantly affecting the total crack width.

  14. A deterministic width function model

    Directory of Open Access Journals (Sweden)

    C. E. Puente

    2003-01-01

    Full Text Available Use of a deterministic fractal-multifractal (FM geometric method to model width functions of natural river networks, as derived distributions of simple multifractal measures via fractal interpolating functions, is reported. It is first demonstrated that the FM procedure may be used to simulate natural width functions, preserving their most relevant features like their overall shape and texture and their observed power-law scaling on their power spectra. It is then shown, via two natural river networks (Racoon and Brushy creeks in the United States, that the FM approach may also be used to closely approximate existing width functions.

  15. SHORT TIMESCALE VARIATIONS OF THE H{alpha} DOUBLE-PEAKED PROFILE OF THE NUCLEUS OF NGC 1097

    Energy Technology Data Exchange (ETDEWEB)

    Schimoia, Jaderson S.; Storchi-Bergmann, Thaisa [Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Campus do Vale, Porto Alegre, RS (Brazil); Nemmen, Rodrigo S. [NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, Maryland (United States); Winge, Claudia [Gemini South Observatory, c/o AURA Inc., Casilla 603, La Serena (Chile); Eracleous, Michael, E-mail: silva.schimoia@ufrgs.br [Department of Astronomy and Astrophysics, the Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States)

    2012-04-01

    The broad (FWHM {approx} 10,000 km s{sup -1}) double-peaked H{alpha} profile from the LINER/Seyfert 1 nucleus of NGC 1097 was discovered in 1991 and monitored for the following 11 years. The profile showed variations attributed to the rotation of gas in a non-axisymmetric Keplerian accretion disk, ionized by a varying radiatively inefficient accretion flow (RIAF) located in the inner parts of the disk. We present and model 11 new spectroscopic observations of the double-peaked profile taken between 2010 March and 2011 March. This series of observations was motivated by the finding that in 2010 March the flux in the double-peaked line was again strong, indeed, in 2010 December, even stronger than in the observations of a decade ago. We also discovered shorter timescale variations than in the previous observations: (1) the first, of {approx}7 days, is interpreted as due to 'reverberation' of the variation of the ionizing source luminosity, and the timescale of 7 days as the light crossing time between the source and the accretion disk; this new timescale and its interpretation provides a distance between the emitting gas and the supermassive black hole and as such introduces a new constraint on its mass; (2) the second, of Almost-Equal-To 5 months, was attributed to the rotation of a spiral arm in the disk, which was found to occur on the dynamical timescale. We use two accretion disk models to fit theoretical profiles to the new data, both having non-axisymmetric emissivities produced by the presence of an one-armed spiral. Our modeling constrains the rotation period for the spiral to be Almost-Equal-To 18 months. This work supports our previous conclusion that the broad double-peaked Balmer emission lines in NGC 1097-and probably also in other low-luminosity active nuclei-originate from an accretion disk ionized by a central RIAF.

  16. THE WIDTH OF A PROOF

    Directory of Open Access Journals (Sweden)

    Gila Hanna

    2014-09-01

    Full Text Available This paper’s aim is to discuss the concept of width of a proof put forward by Timothy Gowers. It explains what this concept means and attempts to show how it relates to other concepts discussed in the existing literature on proof and proving. It also explores how the concept of width of a proof might be used productively in the mathematics curriculum and how it might fit with the various perspectives on learning to prove.

  17. H{alpha} ACTIVITY OF OLD M DWARFS: STELLAR CYCLES AND MEAN ACTIVITY LEVELS FOR 93 LOW-MASS STARS IN THE SOLAR NEIGHBORHOOD

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, Paul; Endl, Michael; Cochran, William D.; Dodson-Robinson, Sarah E., E-mail: paul@astro.as.utexas.edu [Department of Astronomy and McDonald Observatory, University of Texas at Austin, Austin, TX 78712 (United States)

    2013-02-10

    Through the McDonald Observatory M Dwarf Planet Search, we have acquired nearly 3000 high-resolution spectra of 93 late-type (K5-M5) stars over more than a decade using the High Resolution Spectrograph on the Hobby-Eberly Telescope. This sample provides a unique opportunity to investigate the occurrence of long-term stellar activity cycles for low-mass stars. In this paper, we examine the stellar activity of our targets as reflected in the H{alpha} feature. We have identified periodic signals for six stars, with periods ranging from days to more than 10 years, and find long-term trends for seven others. Stellar cycles with P {>=} 1 year are present for at least 5% of our targets. Additionally, we present an analysis of the time-averaged activity levels of our sample, and search for correlations with other stellar properties. In particular, we find that more massive, earlier type (M0-M2) stars tend to be more active than later type dwarfs. Furthermore, high-metallicity stars tend to be more active at a given stellar mass. We also evaluate H{alpha} variability as a tracer of activity-induced radial velocity (RV) variation. For the M dwarf GJ 1170, H{alpha} variation reveals stellar activity patterns matching those seen in the RVs, mimicking the signal of a giant planet, and we find evidence that the previously identified stellar activity cycle of GJ 581 may be responsible for the recently retracted planet f in that system. In general, though, we find that H{alpha} is not frequently correlated with RV at the precision (typically 6-7 m s{sup -1}) of our measurements.

  18. The H-alpha Variations of the Luminous Blue Variable P Cygni: Discrete Absorption Components and the Short S Doradus Phase

    OpenAIRE

    Richardson, Noel D.; Morrison, Nancy D.; Gies, Douglas R.; Markova, N.; Hesselbach, Erica N.; Percy, J. R.

    2011-01-01

    P Cygni is a prototype of the Luminous Blue Variables (or S Doradus variables), and the star displays photometric and emission line variability on a timescale of years (known as the "short S Doradus phase" variations). Here we present new high resolution H-alpha spectroscopy of P Cyg that we combine with earlier spectra and concurrent V-band photometry to document the emission and continuum flux variations over a 24 y time span. We show that the emission and continuum fluxes...

  19. The Subaru FMOS Galaxy Redshift Survey (FastSound). I. Overview of the Survey Targeting on H$\\alpha$ Emitters at $z \\sim 1.4$

    CERN Document Server

    Tonegawa, Motonari; Okada, Hiroyuki; Akiyama, Masayuki; Dalton, Gavin; Glazebrook, Karl; Iwamuro, Fumihide; Maihara, Toshinori; Ohta, Kouji; Shimizu, Ikkoh; Takato, Naruhisa; Tamura, Naoyuki; Yabe, Kiyoto; Bunker, Andrew J; Coupon, Jean; Ferreira, Pedro G; Frenk, Carlos S; Goto, Tomotsugu; Hikage, Chiaki; Ishikawa, Takashi; Matsubara, Takahiko; More, Surhud; Okumura, Teppei; Percival, Will J; Spitler, Lee R; Szapudi, Istvan

    2015-01-01

    FastSound is a galaxy redshift survey using the near-infrared Fiber Multi-Object Spectrograph (FMOS) mounted on the Subaru Telescope, targeting H$\\alpha$ emitters at $z \\sim 1.18$--$1.54$ down to the sensitivity limit of H$\\alpha$ flux $\\sim 2 \\times 10^{-16} \\ \\rm erg \\ cm^{-2} s^{-1}$. The primary goal of the survey is to detect redshift space distortions (RSD), to test General Relativity by measuring the growth rate of large scale structure and to constrain modified gravity models for the origin of the accelerated expansion of the universe. The target galaxies were selected based on photometric redshifts and H$\\alpha$ flux estimates calculated by fitting spectral energy distribution (SED) models to the five optical magnitudes of the Canada France Hawaii Telescope Legacy Survey (CFHTLS) Wide catalog. The survey started in March 2012, and all the observations were completed in July 2014. In total, we achieved $121$ pointings of FMOS (each pointing has a $30$ arcmin diameter circular footprint) covering $20.6...

  20. X-radiation /E greater than 10 keV/, H-alpha and microwave emission during the impulsive phase of solar flares.

    Science.gov (United States)

    Vorpahl, J. A.

    1972-01-01

    A study has been made of the variation in hard (E greater than 10 keV) X-radiation, H-alpha and microwave emission during the impulsive phase of solar flares. Analysis shows that the rise-time in the 20-30-keV X-ray spike depends on the electron hardness. The impulsive phase is also marked by an abrupt, very intense increase in H-alpha emission in one or more knots of the flare. Properties of these H-alpha kernels include: (1) a luminosity several times greater than the surrounding flare, (2) an intensity rise starting about 20-30 sec before, peaking about 20-25 sec after, and lasting about twice as long as the hard spike, (3) a location lower in the chromosphere than the remaining flare, (4) essentially no expansion prior to the hard spike, and (5) a position within 6000 km of the boundary separating polarities, usually forming on both sides of the neutral line near both feet of the same tube of force. Correspondingly, impulsive microwave events are characterized by: (1) great similarity in burst structure with 20-32 keV X-rays but only above 5000 MHz, (2) typical low frequency burst cutoff between 1400-3800 MHz, and (3) maximum emission above 7500 MHz.

  1. Multi-Object Near-IR H-alpha Spectroscopy of z~1 star-forming galaxies in the HDF-N

    CERN Document Server

    Doherty, M; Sharp, R; Dalton, G B; Parry, I; Lewis, I; MacDonald, E; Wolf, C; Hippelein, H; Doherty, Michelle; Bunker, Andrew; Sharp, Robert; Dalton, Gavin; Parry, Ian; Lewis, Ian; Donald, Emily Mac; Wolf, Christian; Hippelein, Hans

    2004-01-01

    We present preliminary results from a programme to obtain multi-object near-infrared spectroscopy of galaxies at redshifts $0.7H-alpha in galaxies at $z\\sim1$. We aim to address the true star formation history of the universe at this epoch: potentially the peak period of star formation activity. H-alpha is the same star formation measure used at low redshift, and hence we can trace star formation without the systematic uncertainties of using different calibrators in different redshift bins, or the extreme dust extinction in the rest-UV. CIRPASS has been successfully demonstrated in multi-object mode on the AAT and WHT. Here we present preliminary results from one of our fields, the Hubble Deep Field North, observed with the WHT. With 150 fibres deployed over an unvignetted field of $\\sim15$arcmin, we have several detections of H-alpha from star forming galaxies at $0.8<...

  2. Spitzer IRAC observations of newly-discovered planetary nebulae from the Macquarie-AAO-Strasbourg H-alpha Planetary Nebula Project

    CERN Document Server

    Cohen, Martin; Green, Anne J; Murphy, Tara; Miszalski, Brent; Frew, David J; Meade, Marilyn R; Babler, Brian; Indebetouw, Remy; Whitney, Barbara A; Watson, Christer; Churchwell, Edward B; Watson, Douglas F

    2007-01-01

    We compare H-alpha, radio continuum, and Spitzer Space Telescope (SST) images of 58 planetary nebulae (PNe) recently discovered by the Macquarie-AAO-Strasbo- urg H-alpha PN Project (MASH) of the SuperCOSMOS H-alpha Survey. Using InfraRed Array Camera (IRAC) data we define the IR colors of PNe and demonstrate good isolation between these colors and those of many other types of astronomical object. The only substantive contamination of PNe in the color-color plane we illustrate is due to YSOs. However, this ambiguity is readily resolved by the unique optical characteristics of PNe and their environs. We also examine the relationships between optical and MIR morphologies from 3.6 to 8.0um and explore the ratio of mid-infrared (MIR) to radio nebular fluxes, which is a valuable discriminant between thermal and nonthermal emission. MASH emphasizes late evolutionary stages of PNe compared with previous catalogs, enabling study of the changes in MIR and radio flux that attend the aging process. Spatially integrated M...

  3. H-alpha Imaging with HST+NICMOS of An Elusive Damped Ly-alpha Cloud at z=0.6

    CERN Document Server

    Bouche, N; Charlton, J C; Bershady, M A; Churchill, C W; Steidel, C C; Bouche, Nicolas; Lowenthal, James D.; Charlton, Jane C.; Bershady, Matthew A.; Churchill, Christopher W.; Steidel, Charles C.

    2000-01-01

    Despite previous intensive ground--based imaging and spectroscopic campaigns and wide-band HST imaging of the z=0.927 QSO 3C336 field, the galaxy that hosts the damped Ly-alpha system along this line--of--sight has eluded detection. We present a deep narrow-band H-alpha image of the field of this z=0.656 damped Ly-alpha absorber, obtained through the F108N filter of NICMOS 1 onboard the Hubble Space Telescope. The goal of this project was to detect any H-alpha emission 10 times closer than previous studies to unveil the damped absorber. We do not detect H-alpha emission between 0.05'' and 6'' (0.24 and 30 $h^{-1}$ kpc) from the QSO, with a 3-sigma flux limit of $3.70 \\times 10^{-17} h^{-2}$ erg/s/cm^2 for an unresolved source, corresponding to a star formation rate (SFR) of $0.3 h^{-2}$ M_sun/yr. This leads to a 3-sigma upper limit of 0.15 M_sun/yr/kpc^2 on the SFR density, or a maximum SFR of 1.87 M_sun/yr assuming a disk of 4 kpc in diameter. This result adds to the number of low redshift damped Ly-alpha ab...

  4. STATISTICAL PROPERTIES OF THE DISK COUNTERPARTS OF TYPE II SPICULES FROM SIMULTANEOUS OBSERVATIONS OF RAPID BLUESHIFTED EXCURSIONS IN Ca II 8542 AND H{alpha}

    Energy Technology Data Exchange (ETDEWEB)

    Sekse, D. H.; Rouppe van der Voort, L. [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, N-0315 Oslo (Norway); De Pontieu, B. [Lockheed Martin Solar and Astrophysics Lab, Org. A021S, Bldg. 252, 3251 Hanover Street Palo Alto, CA 94304 (United States)

    2012-06-20

    Spicules were recently found to exist as two different types when a new class of so-called type II spicules was discovered at the solar limb with the Solar Optical Telescope on board the Hinode spacecraft. These type II spicules have been linked with on-disk observations of rapid blueshifted excursions (RBEs) in the H{alpha} and Ca II 8542 lines. Here we analyze observations optimized for the detection of RBEs in both H{alpha} and Ca II 8542 lines simultaneously at a high temporal cadence taken with the Crisp Imaging Spectropolarimeter at the Swedish Solar Telescope on La Palma. In this study, we used a high-quality time sequence for RBEs at different blueshifts and employed an automated detection routine to detect a large number of RBEs in order to expand on the statistics of RBEs. We find that the number of detected RBEs is strongly dependent on the associated Doppler velocity of the images on which the search is performed. Automatic detection of RBEs at lower velocities increases the estimated number of RBEs to the same order of magnitude expected from limb spicules. This shows that RBEs and type II spicules are indeed exponents of the same phenomenon. Furthermore, we provide solid evidence that Ca II 8542 RBEs are connected to H{alpha} RBEs and are located closer to the network regions with the H{alpha} RBEs being a continuation of the Ca II 8542 RBEs. Our results show that RBEs have an average lifetime of 83.9 s when observed in both spectral lines and that the Doppler velocities of RBEs range from 10 to 25 km s{sup -1} in Ca II 8542 and 30 to 50 km s{sup -1} in H{alpha}. In addition, we automatically determine the transverse motion of a much larger sample of RBEs than previous studies, and find that, just like type II spicules, RBEs undergo significant transverse motions of the order of 5-10 km s{sup -1}. Finally, we find that the intergranular jets discovered at Big Bear Solar Observatory are a subset of RBEs.

  5. Comparing fixed and variable-width Gaussian networks.

    Science.gov (United States)

    K?rková, V?ra; Kainen, Paul C

    2014-09-01

    The role of width of Gaussians in two types of computational models is investigated: Gaussian radial-basis-functions (RBFs) where both widths and centers vary and Gaussian kernel networks which have fixed widths but varying centers. The effect of width on functional equivalence, universal approximation property, and form of norms in reproducing kernel Hilbert spaces (RKHS) is explored. It is proven that if two Gaussian RBF networks have the same input-output functions, then they must have the same numbers of units with the same centers and widths. Further, it is shown that while sets of input-output functions of Gaussian kernel networks with two different widths are disjoint, each such set is large enough to be a universal approximator. Embedding of RKHSs induced by "flatter" Gaussians into RKHSs induced by "sharper" Gaussians is described and growth of the ratios of norms on these spaces with increasing input dimension is estimated. Finally, large sets of argminima of error functionals in sets of input-output functions of Gaussian RBFs are described. PMID:24892273

  6. Optimizing rod window width in positron emission tomography

    International Nuclear Information System (INIS)

    A technique determines the optimal window width for orbiting rod transmission studies in positron emission tomography (PET). Windowing reduces noise in orbiting rod transmission studies. Lines-of-response (LOR) which intersect the rods generate primarily true coincidence events. LOR which pass far from the rods generate random and scatter events. Since the angular position of the orbiting rods is known in real-time, LOR which produce mostly noise are gated off. When optimally determined, the rod window width maximizes the noise equivalent counts (NEC) collected in the transmission study. Transaxial rod projection profiles of trues, randoms, and scatter produce NEC versus window width plots. For the ECAT reg-sign EXACT line of PET systems and a 20-cm water cylinder, optimal is five LOR wide

  7. The narrow X-ray tail and double H-alpha tails of ESO 137-002 in Abell 3627

    OpenAIRE

    Zhang, B.; Sun, M.; Ji, L.; Sarazin, C.; Lin, X. B.; Nulsen, P. E. J.; Roediger, E.; Donahue, M.; Forman, W.; Jones, C.; Voit, G. M.; Kong, X.

    2013-01-01

    We present the analysis of a deep Chandra observation of a ~2L_* late-type galaxy, ESO 137-002, in the closest rich cluster A3627. The Chandra data reveal a long (>40 kpc) and narrow tail with a nearly constant width (~3 kpc) to the southeast of the galaxy, and a leading edge ~1.5 kpc from the galaxy center on the upstream side of the tail. The tail is most likely caused by the nearly edge-on stripping of ESO 137-002's ISM by ram pressure, compared to the nearly face-on stri...

  8. High-energy break-up of 6Li as a tool to study the Big-Bang nucleosynthesis reaction 2H(alpha,gamma)6Li

    OpenAIRE

    Hammache, F.; Heil, M.; Typel, S.; Galaviz, D.; Su?mmerer, K.; Coc, A.; Uhlig, F.; Attallah, F.; Caamano, M.; Cortina, D.; Geissel, H.; Hellstro?m, M.; Iwasa, N.; Kiener, J.; Koczon, P.

    2010-01-01

    The recently claimed observations of non-negligible amounts of 6Li in old halo stars have renewed interest in the Big-Bang Nucleosynthesis (BBN) of 6Li. One important ingredient in the predicted BBN abundance of 6Li is the low-energy 2H(alpha,gamma)6Li cross section. Up to now, the only available experimental result for this cross section showed an almost constant astrophysical S-factor below 400 keV, contrary to theoretical expectations. We report on a new measurement of th...

  9. A Study of Selection Methods for H alpha Emitting Galaxies at z~1.3 for the Subaru/FMOS Galaxy Redshift Survey for Cosmology (FastSound)

    OpenAIRE

    Tonegawa, Motonari; Totani, Tomonori; Akiyama, Masayuki; Dalton, Gavin; Glazebrook, Karl; Iwamuro, Fumihide; Sumiyoshi, Masanao; Tamura, Naoyuki; Yabe, Kiyoto; Coupon, Jean; Goto, Tomotsugu; Spitler, Lee R.

    2013-01-01

    The efficient selection of high-redshift emission galaxies is important for future large galaxy redshift surveys for cosmology. Here we describe the target selection methods for the FastSound project, a redshift survey for H alpha emitting galaxies at z=1.2-1.5 using Subaru/FMOS to measure the linear growth rate f\\sigma 8 via Redshift Space Distortion (RSD) and constrain the theory of gravity. To select ~400 target galaxies in the 0.2 deg^2 FMOS field-of-view from photometri...

  10. M/L, H-alpha Rotation Curves, and HI Measurements for 329 Nearby Cluster and Field Spirals: II. Evidence for Galaxy Infall

    CERN Document Server

    Vogt, N P; Giovanelli, R; Herter, T; Vogt, Nicole P.; Haynes, Martha P.; Giovanelli, Riccardo; Herter, Terry

    2004-01-01

    We have conducted a study of optical and HI properties of spiral galaxies (size, luminosity, H-alpha flux distribution, circular velocity, HI gas mass) to explore the role of gas stripping as a driver of morphological evolution in clusters. We find a strong correlation between the spiral and S0 fractions within clusters, and the spiral fraction scales tightly with cluster X-ray gas luminosity. We explore young star formation and identify spirals that are (1) asymmetric, with truncated H-alpha emission and HI gas reservoirs on the leading edge of the disk, on a first pass through the dense intracluster medium in the cores of rich clusters; (2) strongly HI deficient and stripped, with star formation confined to the inner 5 kpc/h and 3 disk scale lengths; (3) reddened, extremely HI deficient and quenched, where star formation has been halted across the entire disk. We propose that these spirals are in successive stages of morphological transformation, between infalling field spirals and cluster S0s, and that the...

  11. A Study of Selection Methods for H alpha Emitting Galaxies at z~1.3 for the Subaru/FMOS Galaxy Redshift Survey for Cosmology (FastSound)

    CERN Document Server

    Tonegawa, Motonari; Akiyama, Masayuki; Dalton, Gavin; Glazebrook, Karl; Iwamuro, Fumihide; Sumiyoshi, Masanao; Tamura, Naoyuki; Yabe, Kiyoto; Coupon, Jean; Goto, Tomotsugu; Spitler, Lee R

    2013-01-01

    The efficient selection of high-redshift emission galaxies is important for future large galaxy redshift surveys for cosmology. Here we describe the target selection methods for the FastSound project, a redshift survey for H alpha emitting galaxies at z=1.2-1.5 using Subaru/FMOS to measure the linear growth rate f\\sigma 8 via Redshift Space Distortion (RSD) and constrain the theory of gravity. To select ~400 target galaxies in the 0.2 deg^2 FMOS field-of-view from photometric data of CFHTLS-Wide (u*g'r'i'z'), we test several different methods based on color-color diagrams or photometric redshift estimates from spectral energy distribution (SED) fitting. We also test the improvement in selection efficiency that can be achieved by adding near-infrared data from the UKIDSS DXS (J). The success rates of H alpha detection with FMOS averaged over two observed fields using these methods are 11.3% (color-color, optical), 13.6% (color-color, optical+NIR), 17.3% (photo-z, optical), and 15.1% (photo-z, optical+NIR). Sel...

  12. The environmental impacts on the star formation main sequence: an H-alpha study of the newly discovered rich cluster at z=1.52

    CERN Document Server

    Koyama, Yusei; Tadaki, Ken-ichi; Hayashi, Masao; Tanaka, Ichi; Shimakawa, Rhythm

    2014-01-01

    We report the discovery of a strong over-density of galaxies in the field of a radio galaxy at z=1.52 (4C65.22) based on our broad-band and narrow-band (H-alpha) photometry with Subaru Telescope. We find that H-alpha emitters are located in the outskirts of the density peak (cluster core) dominated by passive red-sequence galaxies. This resembles the situation in lower-redshift clusters, suggesting that the newly discovered structure is a well-evolved rich galaxy cluster at z=1.5. Our data suggest that the color-density and stellar mass-density relations are already in place at z~1.5, mostly driven by the passive red massive galaxies residing within Rc<200 kpc from the cluster core. These environmental trends almost disappear when we consider only star-forming (SF) galaxies. We do not find SFR-density or SSFR-density relations amongst SF galaxies, and the location of the SF main sequence does not significantly change with environment. Nevertheless, we find a tentative hint that star-bursting galaxies (up-s...

  13. Development of an Advanced Automated Method for Solar Filament Recognition and Its Scientific Application to a Solar Cycle of MLSO H\\alpha\\ Data

    CERN Document Server

    Hao, Qi; Chen, P F

    2013-01-01

    We developed a method to automatically detect and trace solar filaments in H\\alpha\\ full-disk images. The program is able not only to recognize filaments and determine their properties, such as the position, the area, the spine, and other relevant parameters, but also to trace the daily evolution of the filaments. The program consists of three steps: First, preprocessing is applied to correct the original images; Second, the Canny edge-detection method is used to detect filaments; Third, filament properties are recognized through the morphological operators. To test the algorithm, we applied it to the observations from the Mauna Loa Solar Observatory (MLSO), and the program is demonstrated to be robust and efficient. H\\alpha\\ images obtained by MLSO from 1998 to 2009 are analyzed, and a butterfly diagram of filaments is obtained. It shows that the latitudinal migration of solar filaments has three trends in the Solar Cycle 23: The drift velocity was fast from 1998 to the solar maximum; After the solar maximum...

  14. A very young, compact bipolar H$_2$O maser outflow in the intermediate-mass star-forming LkH$\\alpha$ 234 region

    CERN Document Server

    Torrelles, J M; Estalella, R; Anglada, G; Gómez, J F; Cantó, J; Patel, N A; Trinidad, M A; Girart, J M; Carrasco-González, C; Rodríguez, L F

    2014-01-01

    We report multi-epoch VLBI H$_2$O maser observations towards the compact cluster of YSOs close to the Herbig Be star LkH$\\alpha$ 234. This cluster includes LkH$\\alpha$ 234 and at least nine more YSOs that are formed within projected distances of $\\sim$10 arcsec ($\\sim$9,000 au). We detect H$_2$O maser emission towards four of these YSOs. In particular, our VLBI observations (including proper motion measurements) reveal a remarkable very compact ($\\sim$0.2 arcsec = $\\sim$180 au), bipolar H$_2$O maser outflow emerging from the embedded YSO VLA 2. We estimate a kinematic age of $\\sim$40 yr for this bipolar outflow, with expanding velocities of $\\sim$20 km s$^{-1}$ and momentum rate $\\dot M_w V_w$ $\\simeq$ $10^{-4}-10^{-3}$ M$_{\\odot}$ yr$^{-1}$ km s$^{-1}$$\\times (\\Omega$/$4\\pi)$, powered by a YSO of a few solar masses. We propose that the outflow is produced by recurrent episodic jet ejections associated with the formation of this YSO. Short-lived episodic ejection events have previously been found towards high...

  15. A search for H$\\alpha$ emission in high-metallicity damped Lyman-$\\alpha$ systems at $z \\sim 2.4$

    CERN Document Server

    Wang, Wei-Hao; Prochaska, J Xavier

    2015-01-01

    We report on a sensitive search for redshifted H$\\alpha$ line-emission from three high-metallicity damped Ly$\\alpha$ absorbers (DLAs) at $z \\approx 2.4$ with the Near-infrared Integral Field Spectrometer (NIFS) on the Gemini-North telescope, assisted by the ALTtitude conjugate Adaptive optics for the InfraRed (ALTAIR) system with a laser guide star. Within the NIFS field-of-view, $\\approx 3.22" \\times 2.92"$ corresponding to $\\approx 25$ kpc $ \\times 23$ kpc at $z=2.4$, we detect no statistically significant line-emission at the expected redshifted H$\\alpha$ wavelengths. The measured root-mean-square noise fluctuations in $0.4"$ apertures are $1-3\\times10^{-18}$ erg s$^{-1}$ cm$^{-2}$. Our analysis of simulated, compact, line-emitting sources yields stringent limits on the star-formation rates (SFRs) of the three DLAs, $< 2.2$~M$_{\\odot}$ yr$^{-1}$ ($3\\sigma$) for two absorbers, and $< 11$~M$_{\\odot}$ yr$^{-1}$ ($3\\sigma$) for the third, at all impact parameters within $\\approx 12.5$~kpc to the quasar s...

  16. Comparing H-alpha and HI Surveys as Means to a Complete Local Galaxy Catalog in the Advanced LIGO/Virgo Era

    CERN Document Server

    Metzger, Brian D; Berger, Edo

    2012-01-01

    Identifying the electromagnetic counterparts of gravitational wave (GW) sources detected by upcoming networks of advanced ground-based interferometers will be challenging due in part to the large number of unrelated astrophysical transients within the ~10-100 square degree sky localizations. A potential way to greatly reduce the number of such false positives is to limit detailed follow-up to only those candidates near galaxies within the GW sensitivity range of ~200 Mpc for binary neutron star mergers. Such a strategy is currently hindered by the fact that galaxy catalogs are grossly incomplete within this volume. Here we compare two methods for completing the local galaxy catalog: (1) a narrow-band H-alpha imaging survey; and (2) an HI emission line radio survey. Using H-alpha fluxes, stellar masses (M_star), and star formation rates (SFR) from galaxies in the Sloan Digital Sky Survey (SDSS), combined with HI data from the GALEX Arecibo SDSS Survey and the Herschel Reference Survey, we estimate that a H-alp...

  17. High-energy break-up of 6Li as a tool to study the Big-Bang nucleosynthesis reaction 2H(alpha,gamma)6Li

    CERN Document Server

    Hammache, F; Typel, S; Galaviz, D; Sümmerer, K; Coc, A; Uhlig, F; Attallah, F; Caamano, M; Cortina, D; Geissel, H; Hellström, M; Iwasa, N; Kiener, J; Koczon, P; Kohlmeyer, B; Mohr, P; Schwab, E; Schwarz, K; Schümann, F; Senger, P; Sorlin, O; Tatischeff, V; Thibaud, J P; Vangioni, E; Wagner, A; Walus, W

    2010-01-01

    The recently claimed observations of non-negligible amounts of 6Li in old halo stars have renewed interest in the Big-Bang Nucleosynthesis (BBN) of 6Li. One important ingredient in the predicted BBN abundance of 6Li is the low-energy 2H(alpha,gamma)6Li cross section. Up to now, the only available experimental result for this cross section showed an almost constant astrophysical S-factor below 400 keV, contrary to theoretical expectations. We report on a new measurement of the 2H(alpha,gamma)6Li reaction using the break-up of 6Li at 150 A MeV. Even though we cannot separate experimentally the Coulomb contribution from the nuclear one, we find clear evidence for Coulomb-nuclear interference by analyzing the scattering-angular distributions. This is in-line with our theoretical description which indicates a drop of the S_24-factor at low energies as predicted also by most other models. Consequently, we find even lower upper limits for the calculated primordial 6Li abundance than before.

  18. Macroclumping as solution of the discrepancy between H{\\alpha} and P v mass loss diagnostics for O-type stars

    CERN Document Server

    Šurlan, B; Aret, A; Kubát, J; Oskinova, L M; Torres, A F

    2013-01-01

    Recent studies of O-type stars demonstrated that discrepant mass-loss rates are obtained when different diagnostic methods are employed - fitting the unsaturated UV resonance lines (e.g. P v) gives drastically lower values than obtained from the H{\\alpha} emission. Wind clumping may be the main cause for this discrepancy. In a previous paper, we have presented 3-D Monte-Carlo calculations for the formation of scattering lines in a clumped stellar wind. In the present paper we select five O-type supergiants (from O4 to O7) and test whether the reported discrepancies can be resolved this way. In the first step, the analyses start with simulating the observed spectra with Potsdam Wolf-Rayet (PoWR) non-LTE model atmospheres. The mass-loss rates are adjusted to fit best to the observed H{\\alpha} emission lines. For the unsaturated UV resonance lines (i.e. P v) we then apply our 3-D Monte-Carlo code, which can account for wind clumps of any optical depths, a non-void inter-clump medium, and a velocity dispersion in...

  19. Spreading Widths of Doorway States

    CERN Document Server

    De Pace, A; Weidenmueller, H A

    2010-01-01

    As a function of energy E, the average strength function S(E) of a doorway state is commonly assumed to be Lorentzian in shape and characterized by two parameters, the peak energy E_0 and the spreading width Gamma. The simple picture is modified when the density of background states that couple to the doorway state changes significantly in an energy interval of size Gamma. For that case we derive an approximate analytical expression for S(E). We test our result successfully against numerical simulations. Our result may have important implications for shell--model calculations.

  20. Spreading widths of doorway states

    Energy Technology Data Exchange (ETDEWEB)

    De Pace, A., E-mail: depace@to.infn.i [Istituto Nazionale di Fisica Nucleare, Sezione di Torino, via P. Giuria 1, I-10125 Torino (Italy); Molinari, A. [Dipartimento di Fisica Teorica dell' Universita di Torino, via P. Giuria 1, I-10125 Torino (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Torino, via P. Giuria 1, I-10125 Torino (Italy); Weidenmueller, H.A. [Max-Planck-Institut fuer Kernphysik, D-69029 Heidelberg (Germany)

    2011-01-01

    As a function of energy E, the average doorway strength function S(E)-bar of a doorway state is commonly assumed to be Lorentzian in shape and characterized by two parameters, the peak energy E{sub 0} and the spreading width {Gamma}{sup {down_arrow}}. The simple picture is modified when the density of background states that couple to the doorway state changes significantly in an energy interval of size {Gamma}{sup {down_arrow}}. For that case we derive an approximate analytical expression for S(E)-bar. We test our result successfully against numerical simulations. Our result may have important implications for shell-model calculations.

  1. Measured Cd III Stark widths

    International Nuclear Information System (INIS)

    The Stark FWHM (Full-Width at Half of the Maximal line intensity, W) have been measured for 16 doubly ionized cadmium (Cd III) spectral lines in a pulsed helium discharge in the wavelength interval between 200 nm and 304 nm. The helium discharge was created in the linear low pressure pulsed arc operated at 19 000 K electron temperature and 5.0x1022 m-3 electron density. The cadmium atoms were sputtered from the cadmium (99.9% purity) cylindrical plates located in the linear part of the discharge tube. The high density of the Cd III ions is boosted by cascade ionization processes via the well populated Cd II energy levels due to the Penning and charge exchange effects. The shapes of the Cd III lines are recorded using a spectrograph (McPherson model 209, 1.33 m focal-length with 2400 grooves/mm holographic grating) and intensified CCD camera (Andor DH740-18F-03) as a high-sensitive detection system. The Stark parameters introduced in this Letter are the first published experimental Cd III Stark widths.

  2. Measured Cd III Stark widths

    Energy Technology Data Exchange (ETDEWEB)

    Bukvic, S., E-mail: ebukvic@ff.bg.ac.r [Faculty of Physics, University of Belgrade, P.O.B. 368, Studentski trg 14-16, 11001 Belgrade (Serbia); Djenize, S.; Sreckovic, A.; Nikolic, Z. [Faculty of Physics, University of Belgrade, P.O.B. 368, Studentski trg 14-16, 11001 Belgrade (Serbia)

    2009-07-20

    The Stark FWHM (Full-Width at Half of the Maximal line intensity, W) have been measured for 16 doubly ionized cadmium (Cd III) spectral lines in a pulsed helium discharge in the wavelength interval between 200 nm and 304 nm. The helium discharge was created in the linear low pressure pulsed arc operated at 19 000 K electron temperature and 5.0x10{sup 22} m{sup -3} electron density. The cadmium atoms were sputtered from the cadmium (99.9% purity) cylindrical plates located in the linear part of the discharge tube. The high density of the Cd III ions is boosted by cascade ionization processes via the well populated Cd II energy levels due to the Penning and charge exchange effects. The shapes of the Cd III lines are recorded using a spectrograph (McPherson model 209, 1.33 m focal-length with 2400 grooves/mm holographic grating) and intensified CCD camera (Andor DH740-18F-03) as a high-sensitive detection system. The Stark parameters introduced in this Letter are the first published experimental Cd III Stark widths.

  3. The narrow X-ray tail and double H-alpha tails of ESO 137-002 in Abell 3627

    CERN Document Server

    Zhang, B; Ji, L; Sarazin, C; Lin, X B; Nulsen, P E J; Roediger, E; Donahue, M; Forman, W; Jones, C; Voit, G M; Kong, X

    2013-01-01

    We present the analysis of a deep Chandra observation of a ~2L_* late-type galaxy, ESO 137-002, in the closest rich cluster A3627. The Chandra data reveal a long (>40 kpc) and narrow tail with a nearly constant width (~3 kpc) to the southeast of the galaxy, and a leading edge ~1.5 kpc from the galaxy center on the upstream side of the tail. The tail is most likely caused by the nearly edge-on stripping of ESO 137-002's ISM by ram pressure, compared to the nearly face-on stripping of ESO 137-001 discussed in our previous work. Spectral analysis of individual regions along the tail shows that the gas throughout it has a rather constant temperature, ~1 keV, very close to the temperature of the tails of ESO 137-001, if the same atomic database is used. The derived gas abundance is low (~0.2 solar with the single-kT model), an indication of the multiphase nature of the gas in the tail. The mass of the X-ray tail is only a small fraction (<5%) of the initial ISM mass of the galaxy, suggesting that the stripping ...

  4. Infrared Imaging of z=2.43 Radio Galaxy B3 0731+438 with the Subaru Telescope - Detection of H$\\alpha$ Ionization Cones of a Powerful Radio Galaxy

    OpenAIRE

    Motohara, Kentaro; Iwamuro, Fumihide; Terada, Hiroshi; Goto, Miwa; Iwai, Jun Ichi; Tanabe, Hirohisa; Taguchi, Tomoyuki; Hata, Ryuji; Maihara, Toshinori; Oya, Shin; Iye, Masanori; Kosugi, George; Noumaru, Jun Ichi; Ogasawara, Ryusuke; Sasaki, Toshinori

    2000-01-01

    We report on infrared imaging observations of the z=2.429 radio galaxy B3 0731+438 with the Subaru telescope. The images were taken with the K'-band filter and the 2.25 um narrow-band filter to examine the structure and properties of the Ha+[N II] 6548,6583 emission-line components. The Ha+[N II] emission-line image shows biconical lobes with an extent of 40 kpc, which are aligned with the radio axis. The rest-frame equivalent widths of the emission lines at these cones are ...

  5. Migraine equivalents in childhood.

    Science.gov (United States)

    Teixeira, Karine C S; Montenegro, Maria Augusta; Guerreiro, Marilisa M

    2014-10-01

    Migraine equivalents are a group of periodic and paroxysmal neurologic diseases. Because headache is not a prominent symptom, the diagnosis might be challenging. The objective of the study was to evaluate the frequency and outcome of migraine equivalents. This was a retrospective study. We included benign paroxysmal torticollis of infancy, benign paroxysmal vertigo of infancy, abdominal migraine, cyclic vomiting, aura without migraine, and confusional migraine. We evaluated the frequency of events, treatment, and outcome. Out of 674 children with headache, 38 (5.6%) presented with migraine equivalents. Twenty-one were boys and the mean age was 6.1 years. Fifteen had abdominal migraine, 12 benign paroxysmal vertigo, 5 confusional migraine, 3 aura without migraine, 2 paroxysmal torticollis, and 1 cyclic vomiting. Prophylactic treatment was introduced in 23 patients; 4 lost follow-up and 19 had significant improvement. We conclude that the correct diagnosis of migraine equivalents enables an effective treatment with an excellent outcome. PMID:24092892

  6. Topics in orbit equivalence

    CERN Document Server

    Kechris, Alexander S

    2004-01-01

    This volume provides a self-contained introduction to some topics in orbit equivalence theory, a branch of ergodic theory. The first two chapters focus on hyperfiniteness and amenability. Included here are proofs of Dye's theorem that probability measure-preserving, ergodic actions of the integers are orbit equivalent and of the theorem of Connes-Feldman-Weiss identifying amenability and hyperfiniteness for non-singular equivalence relations. The presentation here is often influenced by descriptive set theory, and Borel and generic analogs of various results are discussed. The final chapter is a detailed account of Gaboriau's recent results on the theory of costs for equivalence relations and groups and its applications to proving rigidity theorems for actions of free groups.

  7. Differential pulse-width pair BOTDA for high spatial resolution sensing.

    Science.gov (United States)

    Li, Wenhai; Bao, Xiaoyi; Li, Yun; Chen, Liang

    2008-12-22

    A differential pulse-width pair Brillouin optical time domain analysis (DPP-BOTDA) for centimeter spatial resolution sensing using meter equivalent pulses is proposed. This scheme uses the time domain waveform subtraction at the same scanned Brillouin frequency obtained from pulse lights with different pulse-widths (e.g. 50ns and 49ns) to form the differential Brillouin gain spectrum (BGS) at each fiber location. The spatial resolution is defined by the average of the rise and fall time equivalent fiber length for a small stress section rather than the pulse-width difference equivalent length. The spatial resolution of 0.18m for the 50/49ns pulse pair and 0.15m for 20/19ns pulse pair over 1km sensing length with Brillouin frequency shift accuracy of 2.6MHz are demonstrated. PMID:19104593

  8. Resonant structure in the disks of spiral galaxies, using phase-reversals in streaming motions from 2D H{\\alpha} Fabry-Perot spectroscopy

    CERN Document Server

    Font, Joan; Epinat, Benoît; Fathi, Kambiz; Gutiérrez, Leonel; Hernandez, Olivier

    2011-01-01

    In this article we introduce a technique for finding resonance radii in a disk galaxy. We use a two-dimensional velocity field in H{\\alpha} emission obtained with Fabry-Perot interferometry, derive the classical rotation curve, and subtract it off, leaving a residual velocity map. As the streaming motions should reverse sign at corotation, we detect these reversals, and plot them in a histogram against galactocentric radius, excluding points where the amplitude of the reversal is smaller than the measurement uncertainty. The histograms show well-defined peaks which we assume to occur at resonance radii, identifying corotations as the most prominent peaks corresponding to the relevant morphological features of the galaxy (notably bars and spiral arm systems). We compare our results with published measurements on the same galaxies using other methods and different types of data.

  9. High-dispersion observations of H-alpha in the suspected brown dwarf, white dwarf binary system G29-38

    International Nuclear Information System (INIS)

    High-dispersion spectroscopy of the H-alpha absorption line of the cool DA white dwarf G29-38 is reported. This is the star for which a recently detected IR excess has been suggested to be due to a possible brown dwarf companion. Three echelle spectra show no evidence for radial-velocity variations larger than about 1.1 + or - 8.7 km/s and are used to derive a weighted heliocentric radial velocity of 33.7 + or - 4.3 kms/s for the white dwarf. The observations of a sharp absorption-line core restricts the possible rotation of the white dwarf to 40 km/s or less and ensures that any surface magnetic field has a strength of 100,000 G or less. These results make it unlikely that the DA white dwarf has previously been in a cataclysmic variable accretion phase. 18 references

  10. The effect of change in width on stress distribution along the curved segments of stents

    International Nuclear Information System (INIS)

    Curved structural members are widely seen in our surroundings, such as railway supports in playgrounds resembling a c-ring structure. The common geometry of the curved member consists of a segment of a circular ring with a uniform width. The curved section is of constant width in most cardiovascular stents. This study focuses on curved strut members whose width changes along the curved segment. The location of the maximum equivalent stress varies depending on the manner in which the width changes. When the width is constant or larger toward the top, the maximum equivalent stress is developed at the top. Meanwhile, when the area is reduced toward the bottom, the largest equivalent stress is developed some distance from the top. Simple equations, based on the mechanics of materials and the theory of elasticity, were compared favorably with the results from finite element analysis. Included are elaborations of the distribution of the change of stress. The suggested strategy of changing the width, with refinements, could be applied to the optimal design of structural members, including pipes and medical devices such as stents

  11. Hadron widths in mixed-phase matter

    International Nuclear Information System (INIS)

    We derive classically an expression for a hadron width in a two-phase region of hadron gas and quark-gluon plasma (QGP). The presence of QGP gives hadrons larger widths than they would have in a pure hadron gas. We find that the ? width observed in a central Au+Au collision at ?s=200 GeV/nucleon is a few MeV greater than the width in a pure hadron gas. The part of observed hadron widths due to QGP is approximately proportional to (dN/dy)-1/3

  12. Morphodynamic response of meandering channels to width variations

    Science.gov (United States)

    Luchi, R.; Bolla Pittaluga, M.; Seminara, G.

    2010-12-01

    Classification schemes of river patterns suggest that, besides the degree of channel sinuosity, an important criterion for the classification of different meandering behaviors is the presence of regular or irregular spatial variations of channel width. Width variations along meander bends are often linked with the occurrence of mid-channel bars and vegetated islands and the consequent bifurcation of the stream into an outer and an inner branch displays the tendency of the reach to deviate towards a multi channel behavior, at least over short temporal and/or spatial scales. Modeling spatial width variations in meandering channels thus appears to be a crucial further step to improve our understanding of the above processes. Recent theoretical studies [Luchi et al., 2010, Zolezzi et al., this conference] have clarified how nonlinear interactions between the effects of width variations and channel curvature determine the morphodynamic response of such rivers. In the present work we extend the recent 3D fully non linear analytical model of flow and bed topography in meandering rivers [Bolla Pittaluga et al., 2009] to include the effect of spatial oscillations of channel width. The model, originally formulated to describe finite amplitude perturbations of bottom topography in channels characterized by arbitrary, yet slow, variations of channel curvature, is now able to model arbitrary, yet slow, variations of channel width. Some substantiation of the model is achieved applying it to a reach of the Magra River (Italy). The present extension also allows us to find the equilibrium configurations of flow and bed topography in two distinct cases that we term “forced” and “autogenic” width respectively. In the former case (“forced” width) the model assumes that the average free surface slope of the curved reach differs from the slope of the equivalent straight reach in order to accommodate the sediment flux supplied from the upstream straight reach. In the latter case (“autogenic” width) we assume that the stream may achieve the same goal by simply allowing the width to vary along the longitudinal direction. This case addresses the intriguing question of how a curved channel proves able to maintain a constant width. In both cases, the analysis of the predicted bed topography underlines the relative importance of the central bar component triggered by spatial width variations and flow nonlinearities with respect to the point bar pattern that dominates in meanders with constant width. Results allow us to understand the conditions under which the meander shifts the regular point bar pattern towards more complex patterns. Bolla Pittaluga, M., Nobile, G., Seminara, G. A non linear model for river meandering. Water Resources Research, 45, W04432, 1-22, doi:10.1029/2008WR007298, 2009. Luchi, R., Zolezzi, G., Tubino, M. Modelling mid-channel bars in meandering channels, Earth Surface Processes and Landforms, 35 (8), 902 - 917, doi: 10.1002/esp.1947, 2010.

  13. Equivalence Testing Mobile Apps

    Directory of Open Access Journals (Sweden)

    Denzler Christoph

    2012-01-01

    Full Text Available Mobile apps are often developed and then evolved on more than one mobile operating system. For the publisher of such apps, the problem is how to ensure equivalence of the product on the various platforms, in the sense of acting equivalently with respect to a test set. In this paper we present an approach that tackles this problem from two directions: architecture and testing. First we will explain the role and pitfalls of reference architectures. Then we will present our equivalence testing framework. It is based on mocking components of the target implementation. Instead of implementing mock components for all platforms, our approach is to implement these mocks only once and run them on a central server. On the tested target device, stub components are injected that forward to their server-based counterparts. Thus the exactly same test code is applied to all platform specific implementations.

  14. Influence of MLC leaf width on biologically adapted IMRT plans

    International Nuclear Information System (INIS)

    Introduction. High resolution beam delivery may be required for optimal biology-guided adaptive therapy. In this work, we have studied the influence of multi leaf collimator (MLC) leaf widths on the treatment outcome following adapted IMRT of a hypoxic tumour. Material and methods. Dynamic contrast enhanced MR images of a dog with a spontaneous tumour in the nasal region were used to create a tentative hypoxia map following a previously published procedure. The hypoxia map was used as a basis for generating compartmental gross tumour volumes, which were utilised as planning structures in biologically adapted IMRT. Three different MLCs were employed in inverse treatment planning, with leaf widths of 2.5 mm, 5 mm and 10 mm. The number of treatment beams and the degree of step-and-shoot beam modulation were varied. By optimising the tumour control probability (TCP) function, optimal compartmental doses were derived and used as target doses in the inverse planning. Resulting IMRT dose distributions and dose volume histograms (DVHs) were exported and analysed, giving estimates of TCP and compartmental equivalent uniform doses (EUDs). The impact of patient setup accuracy was simulated. Results. The MLC with the smallest leaf width (2.5 mm) consistently gave the highest TCPs and compartmental EUDs, assuming no setup error. The difference between this MLC and the 5 mm MLC was rather small, while the MLC with 10 mm leaf width gave considerably lower TCPs. When including randomiderably lower TCPs. When including random and systematic setup errors, errors larger than 5 mm gave only small differences between the MLC types. For setup errors larger than 7 mm no differences were found between non-uniform and uniform dose distributions. Conclusions. Biologically adapted radiotherapy may require MLCs with leaf widths smaller than 10 mm. However, for a high probability of cure it is crucial that accurate patient setup is ensured.

  15. Radioactive waste equivalence

    International Nuclear Information System (INIS)

    The report reviews, for the Member States of the European Community, possible situations in which an equivalence concept for radioactive waste may be used, analyses the various factors involved, and suggests guidelines for the implementation of such a concept. Only safety and technical aspects are covered. Other aspects such as commercial ones are excluded. Situations where the need for an equivalence concept has been identified are processes where impurities are added as a consequence of the treatment and conditioning process, the substitution of wastes from similar waste streams due to the treatment process, and exchange of waste belonging to different waste categories. The analysis of factors involved and possible ways for equivalence evaluation, taking into account in particular the chemical, physical and radiological characteristics of the waste package, and the potential risks of the waste form, shows that no simple all-encompassing equivalence formula may be derived. Consequently, a step-by-step approach is suggested, which avoids complex evaluations in the case of simple exchanges

  16. Correspondences. Equivalence relations

    International Nuclear Information System (INIS)

    We comment on sections paragraph 3 'Correspondences' and paragraph 6 'Equivalence Relations' in chapter II of 'Elements de mathematique' by N. Bourbaki in order to simplify their comprehension. Paragraph 3 exposes the ideas of a graph, correspondence and map or of function, and their composition laws. We draw attention to the following points: 1) Adopting the convention of writting from left to right, the composition law for two correspondences (A,F,B), (U,G,V) of graphs F, G is written in full generality (A,F,B)o(U,G,V) = (A,FoG,V). It is not therefore assumed that the co-domain B of the first correspondence is identical to the domain U of the second (EII.13 D.7), (1970). 2) The axiom of choice consists of creating the Hilbert terms from the only relations admitting a graph. 3) The statement of the existence theorem of a function h such that f = goh, where f and g are two given maps having the same domain (of definition), is completed if h is more precisely an injection. Paragraph 6 considers the generalisation of equality: First, by 'the equivalence relation associated with a map f of a set E identical to (x is a member of the set E and y is a member of the set E and x:f = y:f). Consequently, every relation R(x,y) which is equivalent to this is an equivalence relation in E (symmetrical, transitive, reflexive); then R admits a graph included in E x E, etc. Secondly, by means of the Hilbert term of a relation R submitted to the equivalence. In this last case, if R(x,y) is separately collectivizing in x and y, theta(x) is not the class of objects equivalent to x for R (EII.47.9), (1970). The interest of bringing together these two subjects, apart from this logical order, resides also in the fact that the theorem mentioned in 3) can be expressed by means of the equivalence relations associated with the functions f and g. The solutions of the examples proposed reveal their simplicity

  17. Optically thick line widths in pyrotechnic flares

    Science.gov (United States)

    Douda, B. E.; Exton, R. J.

    1975-01-01

    Experimentally determined sodium line widths for pyrotechnic flares are compared with simple analytical, optically-thick-line-shape calculations. Three ambient pressure levels are considered (760, 150 and 30 torr) for three different flare compositions. The measured line widths range from 1.3 to 481 A. The analytic procedure emphasizes the Lorentz line shape as observed under optically-thick conditions. Calculated widths are in good agreement with the measured values over the entire range.

  18. Red cell distribution width and nonalcoholic steatohepatitis

    OpenAIRE

    Gulcan Kurt, Yasemin; Cayci, Tuncer; Aydin, Fevzi Nuri; Agilli, Mehmet

    2014-01-01

    Red cell distribution width is a measure of deviation of the volume of red blood cells. It is a marker of anisocytosis and often used to evaluate the possible causes of anemia. Elevated red cell distribution width levels are also associated with acute and chronic inflammatory responses. In nonalcoholic steatohepatitis, inflammation is accompanied with steatosis. For assuming red cell distribution width as a marker of nonalcoholic steatohepatitis, intervening factors such as levels of inflamma...

  19. Approximation Algorithms for Digraph Width Parameters

    OpenAIRE

    Kintali, Shiva; Kothari, Nishad; Kumar, Akash

    2011-01-01

    Several problems that are NP-hard on general graphs are efficiently solvable on graphs with bounded treewidth. Efforts have been made to generalize treewidth and the related notion of pathwidth to digraphs. Directed treewidth, DAG-width and Kelly-width are some such notions which generalize treewidth, whereas directed pathwidth generalizes pathwidth. Each of these digraph width measures have an associated decomposition structure. In this paper, we present approximation alg...

  20. Width Distributions for Convex Regular Polyhedra

    CERN Document Server

    Finch, Steven R

    2011-01-01

    The mean width is a measure on three-dimensional convex bodies that enjoys equal status with volume and surface area [Rota]. As the phrase suggests, it is the mean of a probability density f. We verify formulas for mean widths of the regular tetrahedron and the cube. Higher-order moments of f_tetra and f_cube have not been examined until now. Assume that each polyhedron has edges of unit length. We deduce that the mean square width of the regular tetrahedron is 1/3+(3+sqrt(3))/(3*pi) and the mean square width of the cube is 1+4/pi.

  1. Approximation Algorithms for Directed Width Parameters

    CERN Document Server

    Kintali, Shiva; Kumar, Akash

    2011-01-01

    Treewidth of an undirected graph measures how close the graph is to being a tree. Several problems that are NP-hard on general graphs are solvable in polynomial time on graphs with bounded treewidth. Motivated by the success of treewidth, several directed analogues of treewidth have been introduced to measure the similarity of a directed graph to a directed acyclic graph (DAG). Directed treewidth, D-width, DAG-width, Kelly-width and directed pathwidth are some such parameters. In this paper, we present the first approximation algorithms for all these five directed width parameters. For directed treewidth and D-width we achieve an approximation factor of O(sqrt{logn}). For DAG-width, Kelly-width and directed pathwidth we achieve an O({\\log}^{3/2}{n}) approximation factor. Our algorithms are constructive, i.e., they construct the decompositions associated with these parameters. The width of these decompositions are within the above mentioned factor of the corresponding optimal width.

  2. VizieR Online Data Catalog: Equivalent widths of 11 NGC 3680 stars (Mitschang+, 2012)

    Science.gov (United States)

    Mitschang, A. W.; de Silva, G. M.; Zucker, D. B.

    2013-01-01

    Observations were carried out using the Fibre Large Array Multi Element Spectrograph (FLAMES) multi-object fibre system feeding the Ultraviolet and Visual Echelle Spectrograph (UVES; R~45000) at the Very Large Telescope (VLT) as a part of service programme 072.B-0331B over nine nights in 2004. (2 data files).

  3. Occupational dose equivalent limits

    International Nuclear Information System (INIS)

    Methods of limiting individual occupational radiation risks are considered by recognizing the variation of risk with age at exposure. Both somatic and genetic risks are taken into account and a simple formula is proposed for controlling individual cumulative exposure and hence risk. On the basis that the current dose equivalent limit of 50 mSv has been shown to give an average dose equivalent of 5 mSv within a large group of workers, the individual risk within such a group can be limited to no more than three times the average if a cumulative individual limit of 0.5 (N-16)2mSv is applied or to five times the average if a limit of (N-16)2mSv with an over-riding annual limit of 50 mSv is applied where N is the age of the individual. (UK)

  4. Establishing Substantial Equivalence: Metabolomics

    Science.gov (United States)

    Beale, Michael H.; Ward, Jane L.; Baker, John M.

    Modern ‘metabolomic’ methods allow us to compare levels of many structurally diverse compounds in an automated fashion across a large number of samples. This technology is ideally suited to screening of populations of plants, including trials where the aim is the determination of unintended effects introduced by GM. A number of metabolomic methods have been devised for the determination of substantial equivalence. We have developed a methodology, using [1H]-NMR fingerprinting, for metabolomic screening of plants and have applied it to the study of substantial equivalence of field-grown GM wheat. We describe here the principles and detail of that protocol as applied to the analysis of flour generated from field plots of wheat. Particular emphasis is given to the downstream data processing and comparison of spectra by multivariate analysis, from which conclusions regarding metabolome changes due to the GM can be assessed against the background of natural variation due to environment.

  5. Equivalence of Wilson Actions

    CERN Document Server

    Sonoda, H

    2015-01-01

    We introduce the concept of equivalence among Wilson actions. Applying the concept to a real scalar theory on a euclidean space, we derive the exact renormalization group transformation of K. G. Wilson, and give a simple proof of universality of the critical exponents at any fixed point of the exact renormalization group transformation. We also show how to reduce the original formalism of Wilson to the simplified formalism by J. Polchinski.

  6. Plutonium 239 Equivalency Calculations

    International Nuclear Information System (INIS)

    This document provides the basis for converting actual weapons grade plutonium mass to a plutonium equivalency (PuE) mass of Plutonium 239. The conversion can be accomplished by performing calculations utilizing either: (1) Isotopic conversions factors (CFisotope), or (2) 30-year-old weapons grade conversion factor (CF30 yr) Both of these methods are provided in this document. Material mass and isotopic data are needed to calculate PuE using the isotopic conversion factors, which will provide the actual PuE value at the time of calculation. PuE is the summation of the isotopic masses times their associated isotopic conversion factors for plutonium 239. Isotopic conversion factors are calculated by a normalized equation, relative to Plutonium 239, of specific activity (SA) and cumulated dose inhalation affects based on 50-yr committed effective dose equivalent (CEDE). The isotopic conversion factors for converting weapons grade plutonium to PuE are provided in Table-1. The unit for specific activity (SA) is curies per gram (Ci/g) and the isotopic SA values come from reference (1). The cumulated dose inhalation effect values in units of rem/Ci are based on 50-yr committed effective dose equivalent (CEDE). A person irradiated by gamma radiation outside the body will receive a dose only during the period of irradiation. However, following an intake by inhalation, some radionuclides persist in the body and irradiate the various tissues for ody and irradiate the various tissues for many years. There are three groups CEDE data representing lengths of time of 0.5 (D), 50 (W) and 500 (Y) days, which are in reference (2). The CEDE values in the (W) group demonstrates the highest dose equivalent value; therefore they are used for the calculation.

  7. The Equivalence Principle Revisited

    OpenAIRE

    Aldrovandi, R.; Barros, P. B.; Pereira, J. G.

    2002-01-01

    A precise formulation of the strong Equivalence Principle is essential to the understanding of the relationship between gravitation and quantum mechanics. The relevant aspects are reviewed in a context including General Relativity, but allowing for the presence of torsion. For the sake of brevity, a concise statement is proposed for the Principle: "An ideal observer immersed in a gravitational field can choose a reference frame in which gravitation goes unnoticed". This stat...

  8. Finite size scaling study of percolation on the honeycomb lattice with various length to width ratios

    Science.gov (United States)

    Vicsek, T.; Kertész, J.

    1981-01-01

    A Monte Carlo method based on finite size scaling of samples with various length to width ratios is proposed to determine the critical point of percolation. For the honeycomb site problem the ratio 0.6973 ± 0.0008 is found in contradiction with Kondor's result {1}/{?2} which in equivalent to Wu's conjecture.

  9. Direct measurement of the W boson width

    International Nuclear Information System (INIS)

    This Letter describes a direct measurement of the W boson decay width, ?(W), using the high-mass tail of the transverse mass spectrum of W?e? decays recorded by the Collider Detector at Fermilab. We find ?(W)=2.11±0.28(stat) ± 0.16(syst) GeV and compare this direct measurement with indirect means of obtaining the width

  10. Radiative width of the Ksup(*+)(1430)

    International Nuclear Information System (INIS)

    Using the Primakoff formalism, we have extracted the radiative decay width of the Ksup(*)+(1430) produced in coherent interactions of 200 GeV/c K+ mesons in nuclear targets. The width obtained is 240 +- 45 keV, a value reasonably consistent with quark-model predictions. (orig.)

  11. Spiral inflow feeding the nuclear starburst in M83, observed in H-alpha emission with the GHAFAS Fabry-Perot interferometer

    CERN Document Server

    Fathi, Kambiz; Lundgren, Andreas A; Carignan, Claude; Hernandez, Olivier; Amram, Philippe; Balard, Philippe; Boulesteix, Jacques; Gach, Jean-Luc; Knapen, Johan H; Relaño, Monica

    2007-01-01

    We present observations of the nearby barred starburst galaxy, M83 (NGC5236), with the new Fabry-Perot interferometer GHAFAS mounted on the 4.2 meter William Herschel Telescope on La Palma. The unprecedented high resolution observations, of 16 pc/FWHM, of the H-alpha-emitting gas cover the central two kpc of the galaxy. The velocity field displays the dominant disk rotation with signatures of gas inflow from kpc scales down to the nuclear regions. At the inner Inner Lindblad Resonance radius of the main bar and centerd at the dynamical center of the main galaxy disk, a nuclear $5.5 (\\pm 0.9) \\times 10^8 M_\\odot$ rapidly rotating disk with scale length of $60 \\pm 20$ pc has formed. The nuclear starburst is found in the vicinity as well as inside this nuclear disk, and our observations confirm that gas spirals in from the outer parts to feed the nuclear starburst, giving rise to several star formation events at different epochs, within the central 100 pc radius of M83.

  12. Study of LINER sources with broad H(alpha) emission. X-ray properties and comparision to luminous AGN and X-ray binaries

    CERN Document Server

    George, Younes; Sabra, B; Reeves, J N

    2011-01-01

    [Abridged]We study the X-ray properties of LINER sources with definite detection of a broad H(alpha) emission line in their optical spectra, LINER 1s from Ho et al. sample. These objects preferentially harbor a low luminosity active nucleus at the center and show small or no intrinsic absorption (<10^(22) cm^(-1)). We analyzed all available X-ray archived XMM-Newton and Chandra observations of 13 LINER 1s satisfying the above criterion in a systematic homogeneous way. We looked for any correlations between the X-ray properties and the intrinsic parameters of our sample of LINER 1s. An absorbed power-law gave a good fit to the spectra of 9 out of the 13 sources. A thermal component and an absorbed power-law were required in the remaining 4 sources. We found a photon index between 1.3\\pm0.2 for the hardest source and 2.4^(+0.2)_(-0.3) for the softest one with a mean value of 1.9\\pm0.2 and a dispersion sigma=0.3. The thermal component had a mean temperature kT~0.6 keV. Significant short (hours to days) time-s...

  13. The dynamics of z=0.8 H-alpha-selected star-forming galaxies from KMOS/CF-HiZELS

    CERN Document Server

    Sobral, David; Stott, John; Matthee, Jorryt; Bower, Richard G; Smail, Ian; Best, Philip N; Geach, James E; Sharples, Ray M

    2013-01-01

    We present the spatially resolved H-alpha (Ha) dynamics of sixteen star-forming galaxies at z~0.81 using the new KMOS multi-object integral field spectrograph on the ESO VLT. These galaxies were selected using 1.18 um narrow-band imaging from the 10 deg^2 CFHT-HiZELS survey of the SA22hr field, are found in a ~4Mpc over-density of Ha emitters and likely reside in a group/intermediate environment, but not a cluster. We confirm and identify a rich group of star-forming galaxies at z=0.813+-0.003, with thirteen galaxies within 1000 km/s of each other, and 7 within a diameter of 3Mpc. All our galaxies are "typical" star-forming galaxies at their redshift, 0.8+-0.4 SFR*(z=0.8), spanning a range of specific star formation rate of sSFR=0.2-1.1 Gyr^-1 and have a median metallicity very close to solar of 12+log(O/H)=8.62+-0.06. We measure the spatially resolved Ha dynamics of the galaxies in our sample and show that thirteen out of sixteen galaxies can be described by rotating disks and use the data to derive inclinat...

  14. Equivalences of coisotropic submanifolds

    DEFF Research Database (Denmark)

    Schaetz, Florian; Zambon, Marco

    2014-01-01

    We study the role that Hamiltonian and symplectic diffeomorphisms play in the deformation problem of coisotropic submanifolds. We prove that the action by Hamiltonian diffeomorphisms corresponds to the gauge-action of the $L_\\infty$-algebra of Oh and Park. Moreover we introduce the notion of extended gauge-equivalence and show that in the case of Oh and Park's $L_\\infty$-algebra one recovers the action of symplectic isotopies on coisotropic submanifolds. Finally, we consider the transversally integrable case in detail.

  15. 7.EE Equivalent Expressions?

    Science.gov (United States)

    This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: If we multiply $\\frac{x}{2} + \\frac34$ by 4, we get $2x+3$. Is $2x+3$ an equivalent expression to $\\frac{x}{2} + \\frac34$?...

  16. Equivalence of Dual Graphs

    Directory of Open Access Journals (Sweden)

    M. Azram

    2013-07-01

    Full Text Available Because of interesting and useful geometric as well as topological properties, alternating knots (links were regarded to have an important role in knot theory and 3-manifold theory. Many knots with crossing number less than 10 are alternating. It was the properties of alternating knots that enable the earlier knot tabulators to construct tables with relatively few mistakes or omissions. Graphs of knots (links have been repeatedly employed in knot theory. This article is devoted to establish relationship between knots and planar graphs. This relationship not only enables us see the equivalence of the graphs corresponding to black regions and the dual graph corresponding to white regions.

  17. Response of a position-sensitive tissue equivalent proportional counter to heavy ions

    International Nuclear Information System (INIS)

    We have been developing a new space dosimeter named ''Position Sensitive Tissue Equivalent Proportional Counter (PS-TEPC)'' with tissue equivalency and position sensitivity. The detector with the conductive tissue-equivalent plastics as a drift cage was irradiated using Iron ions with the energies of 500 MeV/n. The energy resolution of 9.9% Full Width Half Maximum (FWHM) was obtained from the distribution of energy deposited in the detector. (author)

  18. Thermal width of quarkonium from holography

    Energy Technology Data Exchange (ETDEWEB)

    Fadafan, Kazem Bitaghsir; Tabatabaei, Seyed Kamal [Shahrood University, Physics Department, Shahrood (Iran, Islamic Republic of)

    2014-04-15

    From the AdS/CFT correspondence, the effects of charge and finite 't Hooft coupling correction on the thermal width of a heavy quarkonium are investigated. To study the charge effect,we consider Maxwell charge which is interpreted as quarkmedium. In the case of finite 't Hooft coupling corrections, R{sup 4} terms and Gauss-Bonnet gravity have been considered, respectively. It is shown that these corrections affect the thermal width. It is also argued that by decreasing the 't Hooft coupling, the thermal width becomes effectively smaller. Interestingly, this is similar to analogous calculations in a weakly coupled plasma. (orig.)

  19. On the holographic width of flux tubes

    CERN Document Server

    Giataganas, Dimitrios

    2015-01-01

    We investigate the width of the flux tube between heavy static quark charges. Using the gauge/gravity duality, we find the properties of the minimal connected surface related to the width of the bound state. We show that in the confining phase, the logarithmic broadening predicted by the effective string description and observed in lattice simulations is a generic property of all confining backgrounds. We also study the transverse fluctuations of the string connecting two static quarks in curved backgrounds. Our formalism is applied to AdS space where we compute the expectation value of the square of transverse deviations of the string, a quantity related to the width.

  20. Finite width effects in Higgs decays as a means of measuring massive particle widths

    OpenAIRE

    Summers, D. J.

    1995-01-01

    We calculate decays of a Standard Model Higgs boson to a virtual massive particle and discuss how this depends on the massive particle total width. If the partial width of Higgs to a virtual massive particle can be measured this gives a measurement of that massive particle's width. We discuss how one would go about measuring these partial widths of a Higgs experimentally, and how this could lead to a measurement of the $W$ boson and $t$ quark width. For the latter extreme de...

  1. Stuttering Equivalence for Parity Games

    CERN Document Server

    Cranen, Sjoerd; Willemse, Tim A C

    2011-01-01

    We study the process theoretic notion of stuttering equivalence in the setting of parity games. We demonstrate that stuttering equivalent vertices have the same winner in the parity game. This means that solving a parity game can be accelerated by minimising the game graph with respect to stuttering equivalence. While, at the outset, it might not be clear that this strategy should pay off, our experiments using typical verification problems illustrate that stuttering equivalence speeds up solving parity games in many cases.

  2. Influence of film width and magnetic field orientation on AC loss in YBCO thin film

    Energy Technology Data Exchange (ETDEWEB)

    Amemiya, Naoyuki [Faculty of Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya, Yokohama 240-8501 (Japan); Nishioka, Takamasa [Faculty of Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya, Yokohama 240-8501 (Japan); Jiang, Zhenan [Faculty of Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya, Yokohama 240-8501 (Japan); Yasuda, Kenji [Super-GM, 5-14-10 Nishi Tenma, Kita, Osaka 530-0047 (Japan)

    2004-03-01

    Three YBCO thin films on sapphire substrate with widths of 3, 5, and 10 mm were prepared, and their AC loss characteristics were studied experimentally. The total AC loss dissipated in samples carrying AC transport current in an AC transverse magnetic field was measured by an electromagnetic method. The total AC loss in YBCO film is proportional to the film width and the perpendicular magnetic field component, a component of the transverse magnetic field that is perpendicular to the film wide face. Reduction of the film width and/or the perpendicular magnetic field component is an essential means of decreasing the total AC loss. When plotting the total AC loss divided by film width against the perpendicular magnetic field component, curves for various film widths and field angles almost agree with each other. The total AC loss can be estimated by analytical expressions except in an intermediate range of the perpendicular magnetic field component. The experimental results indicate two engineering approaches for reducing the total AC loss in YBCO film: decreasing the film width and decreasing the perpendicular magnetic field component. Findings have shown empirically that decreasing the film width and decreasing sin{alpha}, where {alpha} is the field angle, are equivalently effective in reducing the total AC loss.

  3. Influence of film width and magnetic field orientation on AC loss in YBCO thin film

    International Nuclear Information System (INIS)

    Three YBCO thin films on sapphire substrate with widths of 3, 5, and 10 mm were prepared, and their AC loss characteristics were studied experimentally. The total AC loss dissipated in samples carrying AC transport current in an AC transverse magnetic field was measured by an electromagnetic method. The total AC loss in YBCO film is proportional to the film width and the perpendicular magnetic field component, a component of the transverse magnetic field that is perpendicular to the film wide face. Reduction of the film width and/or the perpendicular magnetic field component is an essential means of decreasing the total AC loss. When plotting the total AC loss divided by film width against the perpendicular magnetic field component, curves for various film widths and field angles almost agree with each other. The total AC loss can be estimated by analytical expressions except in an intermediate range of the perpendicular magnetic field component. The experimental results indicate two engineering approaches for reducing the total AC loss in YBCO film: decreasing the film width and decreasing the perpendicular magnetic field component. Findings have shown empirically that decreasing the film width and decreasing sin?, where ? is the field angle, are equivalently effective in reducing the total AC loss

  4. Establishing Substantial Equivalence: Proteomics

    Science.gov (United States)

    Lovegrove, Alison; Salt, Louise; Shewry, Peter R.

    Wheat is a major crop in world agriculture and is consumed after processing into a range of food products. It is therefore of great importance to determine the consequences (intended and unintended) of transgenesis in wheat and whether genetically modified lines are substantially equivalent to those produced by conventional plant breeding. Proteomic analysis is one of several approaches which can be used to address these questions. Two-dimensional PAGE (2D PAGE) remains the most widely available method for proteomic analysis, but is notoriously difficult to reproduce between laboratories. We therefore describe methods which have been developed as standard operating procedures in our laboratory to ensure the reproducibility of proteomic analyses of wheat using 2D PAGE analysis of grain proteins.

  5. Curves of Constant Width and Reuleaux Polygons

    Science.gov (United States)

    This page features information on constant width curves, also known as Orbiform Curves or Reuleaux Polygons. One application is to the Wankel Engine. The page contains animations, plots, an historical sketch, and links to Mathematica code.

  6. Infinite-dimensional generalization of Kolmogorov widths

    OpenAIRE

    Kounchev, Ognyan

    2011-01-01

    Recently the theory of widths of Kolmogorov-Gelfand has received a great deal of interest due to its close relationship with the newly born area of Compressive Sensing in Signal Processing. However fundamental problems of the theory of widths in multidimensional Theory of Functions remain untouched, as well as analogous problems in the theory of multidimensional Signal Analysis. In the present paper we provide a multidimensional generalization of the original result of Kolmo...

  7. Evolution of GDR width with angular momentum

    International Nuclear Information System (INIS)

    The phenomenon of giant dipole resonance (GDR) built on excited states in nuclei continues to be a subject of active research by many groups. Experiments have been carried out to study the dependence of temperature and angular momentum on GDR observables like centroid, width and strength. With a need to study the evolution of GDR width and nuclear deformation as a function of angular momentum and temperature, we initiated a program to study 144Sm at different excitation energies

  8. Optimizing leaf widths for a multileaf collimator

    International Nuclear Information System (INIS)

    The multileaf collimator (MLC) is becoming a standard accessory of modern linac in shaping radiation fields. However, for a given target (projection), the radiation field shaped by an MLC has a stepwise boundary and is not identical to the desired field that exactly conforms to the target. That means there are always under-blocked and/or over-blocked areas. The total area of discrepancy depends on MLC leaf widths. The purpose of this study is to develop an optimization model for determining leaf widths so that the total area of discrepancy between MLC-shaped fields and the desired ones can be minimized. The optimization model regards leaf widths as variables, the total area of discrepancy between MLC-shaped fields and the desired fields as an objective function, and the total width of all leaves as a constraint. A problem described by the model is solved with the hybrid of a simulated annealing technique (ASA, Lester Ingber, 1993) and a gradient technique (DONLP2, P Spellucci, 2001). The performance of the optimization model was evaluated on 634 target fields continuously selected from the patient database of a treatment planning system. The lengths of these fields ranged from 3.9 to 38.7 cm and had an average of 15.3 cm. The total area of discrepancy was compared between an MLC with optimal leaf widths and a conventional MLC with the same number of leaf pairs. Optimal leaf widths were obtained for an MLC with total leaf pairs of 28, 40 and 60, respectively, which cor of 28, 40 and 60, respectively, which corresponded to three types of conventional MLCs. The optimal leaf width first decreases slightly and then nonlinearly increases with the distance away from the central line. Compared with the MLC with conventional leaf width arrangement, the MLCs with optimal leaf width arrangement reduced the total area of discrepancy by 11.1%, 28.6% and 25.0%, respectively. Optimizing leaf widths can either improve the conformity of MLC-shaped fields to the treatment targets when the number of leaf pairs does not change, or reduce the number of leaf pairs without sacrifice of field conformity.

  9. Appropriate energy window width for gamma camera

    Directory of Open Access Journals (Sweden)

    Jabbari N

    2004-06-01

    Full Text Available Introduction: Scatter radiation is one of the major sources of error in nuclear medicine data processing. Different methods of scatter correction have been introduced in order to improve the quality of data. However the best method is to avoid recording of scatter photons in acquisition. The only difference between scattered and non-scattered photons is the energy. Pulse height analyzer is the only option available to discriminate primary photons from scattered ones. Energy resolution of the gamma camera is gradually improving consequently the energy window width has to be decreased accordingly. In this study we tried to determine the most appropriate energy window width for present gamma camera systems. Methods and Materials: Since it is not possible to retrieve the data spectrum from the most of the gamma camera systems, a simple method was developed to extract the data from the image of the energy spectrum. Using a scatter phantom different level of scatter and count rate were generated and corresponding energy spectrum data were analyzed. It was assumed that around the peak of the spectrum, the primary photons obey a Gaussian distribution. Results: The data were analyzed using three different methods. All methods prove that the optimum window width regarding the present gamma camera energy resolution is 15%. At this level, the scattered radiation is decreased to 5%. In comparison to the conventional widow width of 20%, the sensitivity does not change dramatically. Conclusion: At the present, for most gamma camera, the energy window width of 20% is recommended. However occasionally energy window width of 15% and 25% are also used. In this study the energy spectrum at different levels of scatter were analyzed and the most suitable energy window width was found to be 15% for the gamma camera having approximate energy resolution of 11%. At this window setting the scatter decreases to 5% of the total counts recorded. Visually the quality of the images dose not improves significantly. However accuracy of data quantification improve significantly.

  10. CF-HiZELS, a 10 deg$^2$ emission-line survey with spectroscopic follow-up: H\\alpha, [OIII]+H\\beta\\ and [OII] luminosity functions at z=0.8, 1.4 and 2.2

    CERN Document Server

    Sobral, David; Best, Philip N; Smail, Ian; Khostovan, Ali A; Milvang-Jensen, Bo; Kim, Jae-Woo; Stott, John; Calhau, João; Nayyeri, Hooshang; Mobasher, Bahram

    2015-01-01

    We present results from the largest contiguous narrow-band survey in the near-infrared. We have used WIRCam/CFHT and the lowOH2 filter (1.187$\\pm$0.005 \\mu m) to survey ~10 deg$^2$ of contiguous extragalactic sky in the SA22 field. A total of ~6000 candidate emission-line galaxies are found. We use deep CFHTLS $ugriz$ and UKIDSS DXS $J$ and $K$ data to obtain robust photometric redshifts. We combine our data with HiZELS (COSMOS+UDS) and explore VVDS, VIPERS, KMOS and obtain our own spectroscopic follow-up with FMOS and MOSFIRE to derive large samples of high-redshift emission-line selected galaxies: 3471 H\\alpha\\ emitters at z=0.8, 1343 [OIII]+H\\beta\\ emitters at z=1.4 and 572 [OII] emitters at z=2.2. We probe co-moving volumes of >10$^6$ Mpc$^3$ and find significant over-densities, including an 8.5\\sigma\\ (spectroscopically confirmed) over-density of H\\alpha\\ emitters at z=0.81. We derive H\\alpha, [OIII]+H\\beta\\ and [OII] luminosity functions at z=0.8, 1.4 and 2.2, respectively, and present implications for ...

  11. Radiative width of the K*+(1430) and radiative width of the A2(1310)

    International Nuclear Information System (INIS)

    Using the Primakoff formalism, we have extracted the radiative decay width of the K*+(1430) produced in coherent interactions of 200 GeV/c K+ mesons in nuclear targets and the radiative decay width of the A2+(1310) produced in coherent interactions of 200 GeV/c ?+ mesons in nuclear targets. The widths obtained are 240 +- 45 keV and 295 +- 60 keV, respectively, values reasonably consistent with quark-model predictions

  12. Coastal dune behaviour at different beach widths

    Science.gov (United States)

    Keijsers, Joep; Poortinga, Ate; De Groot, Alma; Riksen, Michel

    2013-04-01

    Along the Dutch coastline, sand dunes form a natural defence against the sea. Together with the size of the beach, dune dimensions determine whether coastal safety requirements are met. Dunes grow via onshore transport of sediment by wind and erode mainly through the impact of sea waves during storms. Previous studies show that both dune growth and erosion are influenced by beach dimensions. A wide beach (500 m) is expected to provide more sediment for onshore transport and to dissipate more wave energy than a narrow beach (50 m). Hence, all other factors being equal, dune growth is likely to be higher on wide beaches than on narrow beaches. This study quantifies the relation between dune behaviour and beach width. Results will be used to improve and test predictive modelling of shoreline development. The combined effect of beach dimensions on dune behaviour was studied by comparing changes in dune volume at beaches of different widths. These volume changes represent the net effect of sediment accumulation and sediment loss of the dune. Yearly elevation measurements of 200 locations along the Dutch coastline were used, taken between 1960 and 2010. From these elevation measurements, beach width and yearly changes in dune volume were derived. Subsequently, measurements were grouped in beach width classes, each containing 100 paired observations of dune volume change and beach width. For these classes, the average and variability of volume changes were calculated. The results show a clear relation between beach width and dune behaviour. Going from narrow to wide beaches, average volume changes increase to a maximum. The beach width at which maximum growth is reached, differs per study area. For extremely wide beaches, average rates are lower. These cases are associated with development of transport inhibiting beach-topography. Inverse to the trend in volume changes, the variability of dune behaviour is highest on narrow beaches and decreases for wider beach classes. The positive relation between dune growth and beach width can be explained by both increased sediment input and reduced dune erosion at wider beaches. Further research is required to separate the effect of beach width on dune accretion from the effect on dune erosion.

  13. Line width of Josephson flux flow oscillators

    DEFF Research Database (Denmark)

    Koshelets, V.P.; Dmitriev, P.N.

    2002-01-01

    A combination of wide-band electronic tunability and moderate free-running line width makes the Josephson flux flow oscillator (FFO) a perfect on-chip local oscillator for integrated submillimeter-wave SIS receivers. The possibility of FFO phase locking at all frequencies of interest has to be proven before one initiates real FFO applications. To achieve this goal a comprehensive set of line width measurements of the FFO operating in different regimes has been performed. FFOs with tapered shape have been successfully implemented in order to avoid the superfine resonant structure with voltage spacing of about 20 nV and extremely low differential resistance, recently observed in the IVC of the standard rectangular geometry. The obtained results have been compared with existing theories and FFO models in order to understand and possibly eliminate excess noise in the FFO. The intrinsic line width increases considerably at voltages above the boundary voltage because of the abrupt increase of the internal damping due to Josephson self-coupling. The influence of FFO parameters, in particular the differential resistances associated both with the bias current and with the applied magnetic field on the radiation line width, has been studied. Possible means of decreasing the free-running FFO line width will be discussed.

  14. Logic Petri Nets and Equivalency

    OpenAIRE

    Du, Y. Y.; Guo, B. Q.

    2009-01-01

    Logic Petri nets (LPN) can describe and analyze batch processing function and passing value indeterminacy in cooperative systems and its practical applications are shown with some nontrivial examples. This study focuses on the analysis of the modeling power of LPNs and the equivalency between LPNs and Petri nets with inhibitor arcs (IPN). The equivalency is proved formally and a constructing algorithm of equivalent IPNs from LPNs is proposed based on the disjunctive normal forms of logi...

  15. Model-Checking Process Equivalences

    OpenAIRE

    Martin Lange; Etienne Lozes; Manuel Vargas Guzmán

    2012-01-01

    Process equivalences are formal methods that relate programs and system which, informally, behave in the same way. Since there is no unique notion of what it means for two dynamic systems to display the same behaviour there are a multitude of formal process equivalences, ranging from bisimulation to trace equivalence, categorised in the linear-time branching-time spectrum. We present a logical framework based on an expressive modal fixpoint logic which is capable of defini...

  16. Constraints on widths of mixed pentaquark multiplets

    CERN Document Server

    Mohta, V

    2004-01-01

    We determine constraints on the partial widths of mixed pentaquark multiplets in the framework of heavy baryon chiral perturbation theory (HB$\\chi$PT). The partial widths satisfy a GMO-type relation at leading order in HB$\\chi$PT, for arbitrary mixing. The widths of N(1440), N(1710), and $\\Theta(1540)$ are not consistent with ideal mixing, $\\theta_{N} = 35.3^{\\circ}$, but are consistent with $\\theta_{N} \\lesssim 25^{\\circ}$. Furthermore, there are parameter values in HB$\\chi$PT that produce such a mixing angle while allowing the identification of the mass spectrum above. As an alternative to non-ideal mixing, we also suggest reasons for giving up on N(1440) as a pure pentaquark state.

  17. Alliances and Bisection Width for Planar Graphs

    DEFF Research Database (Denmark)

    Olsen, Martin; Revsbæk, Morten

    2013-01-01

    An alliance in a graph is a set of vertices (allies) such that each vertex in the alliance has at least as many allies (counting the vertex itself) as non-allies in its neighborhood of the graph. We show that any planar graph with minimum degree at least 4 can be split into two alliances in polynomial time. We base this on a proof of an upper bound of n on the bisection width for 4-connected planar graphs with an odd number of vertices. This improves a recently published n?+?1 upper bound on the bisection width of planar graphs without separating triangles and supports the folklore conjecture that a general upper bound of n exists for the bisection width of planar graphs.

  18. Preequilibrium escape widths of giant resonances

    Science.gov (United States)

    Roos, M. O.; Dias, H.; Rodriguez, O.; Teruya, N.; Hussein, M. S.

    2002-08-01

    In this work we present a calculation of the 2p-2h preequilibrium escape width of giant resonances for the nuclei 40Ca, 90Zr, and 208Pb. The problem studied here involves an excited nucleus in the 1p-1h configuration, evolving to the 2p-2h configuration with the 1p in the continuum. The theoretical approach used for our calculations is based on the statistical multistep compound theory of Feshbach, Kerman, and Koonin (FKK) and on the particle-hole state densities given by Obložinský. Our calculations show that although different state densities supply a similar result for the damping width, the escape width is strongly dependent on the nuclei, on the binding energy of the emitted nucleon, and the excitation energy of the giant resonance.

  19. Logic Petri Nets and Equivalency

    Directory of Open Access Journals (Sweden)

    Y.Y. Du

    2009-01-01

    Full Text Available Logic Petri nets (LPN can describe and analyze batch processing function and passing value indeterminacy in cooperative systems and its practical applications are shown with some nontrivial examples. This study focuses on the analysis of the modeling power of LPNs and the equivalency between LPNs and Petri nets with inhibitor arcs (IPN. The equivalency is proved formally and a constructing algorithm of equivalent IPNs from LPNs is proposed based on the disjunctive normal forms of logic input/output expressions. Moreover, the size of an LPN model is smaller than that of the equivalent IPN model.

  20. Model-Checking Process Equivalences

    Directory of Open Access Journals (Sweden)

    Martin Lange

    2012-10-01

    Full Text Available Process equivalences are formal methods that relate programs and system which, informally, behave in the same way. Since there is no unique notion of what it means for two dynamic systems to display the same behaviour there are a multitude of formal process equivalences, ranging from bisimulation to trace equivalence, categorised in the linear-time branching-time spectrum. We present a logical framework based on an expressive modal fixpoint logic which is capable of defining many process equivalence relations: for each such equivalence there is a fixed formula which is satisfied by a pair of processes if and only if they are equivalent with respect to this relation. We explain how to do model checking, even symbolically, for a significant fragment of this logic that captures many process equivalences. This allows model checking technology to be used for process equivalence checking. We show how partial evaluation can be used to obtain decision procedures for process equivalences from the generic model checking scheme.

  1. Fixed-Width Group CSD Multiplier Design

    Science.gov (United States)

    Kim, Yong-Eun; Cho, Kyung-Ju; Chung, Jin-Gyun; Huang, Xinming

    This paper presents an error compensation method for fixed-width group canonic signed digit (GCSD) multipliers that receive a W-bit input and generate a W-bit product. To efficiently compensate for the truncation error, the encoded signals from the GCSD multiplier are used for the generation of the error compensation bias. By Synopsys simulations, it is shown that the proposed method leads to up to 84% reduction in power consumption and up to 78% reduction in area compared with the fixed-width modified Booth multipliers.

  2. High Fin Width Mosfet Using Gaa Structure

    OpenAIRE

    Tripathi, S. L.; Ramanuj Mishra; Mishra, R. A.

    2012-01-01

    This paper describes the design and optimization of gate-all-around (GAA) MOSFETs structures. The optimum value of Fin width and Fin height are investigated for superior subthreshold behavior. Also the performance of Fin shaped GAA with gate oxide HfO2 are simulated and compared with conventional gate oxide SiO2 for the same structure. As a result, it was observed that the GAA with high K dielectric gate oxide has more possibility to optimize the Fin width with improved performance. All the s...

  3. High Fin Width Mosfet Using Gaa Structure

    Directory of Open Access Journals (Sweden)

    S.L.Tripathi

    2012-11-01

    Full Text Available This paper describes the design and optimization of gate-all-around (GAA MOSFETs structures. The optimum value of Fin width and Fin height are investigated for superior subthreshold behavior. Also the performance of Fin shaped GAA with gate oxide HfO2 are simulated and compared with conventional gate oxide SiO2 for the same structure. As a result, it was observed that the GAA with high K dielectric gate oxide has more possibility to optimize the Fin width with improved performance. All the simulations are performed on 3-D TCAD device simulator.

  4. Nonlocal potentials and resonances of narrow width

    International Nuclear Information System (INIS)

    This paper discusses resonances of narrow width in the context of bound states embedded in the continuum spectrum of nonlocal potentials. Feshbach's theory of nuclear reactions leads directly to resonance theory, and we base our discussion here on the techniques he developed for shifting nuclear many-body aspects into effective single-particle nonlocal potentials. In our formulation, the many-body state of the compound nucleus is represented by a single-particle state. The basis for our discussion is a two channel model of a resonance of zero width, with a continuum bound state originating from the coupling of a bound state to the single-particle scattering state. We give a specific example of a model which leads to an arbitrarily narrow (nonzero width) resonance, and demonstrate that the width of the resonance produced by breaking the continuum bound state is proportional to (?-1)2, where the parameter ? is such that ? = 1 corresponds to the condition necessary for the existence of a continuum bound state

  5. Bounding the Higgs boson width through interferometry.

    Science.gov (United States)

    Dixon, Lance J; Li, Ye

    2013-09-13

    We study the change in the diphoton-invariant-mass distribution for Higgs boson decays to two photons, due to interference between the Higgs resonance in gluon fusion and the continuum background amplitude for gg???. Previously, the apparent Higgs mass was found to shift by around 100 MeV in the standard model in the leading-order approximation, which may potentially be experimentally observable. We compute the next-to-leading-order QCD corrections to the apparent mass shift, which reduce it by about 40%. The apparent mass shift may provide a way to measure, or at least bound, the Higgs boson width at the Large Hadron Collider through "interferometry." We investigate how the shift depends on the Higgs width, in a model that maintains constant Higgs boson signal yields. At Higgs widths above 30 MeV, the mass shift is over 200 MeV and increases with the square root of the width. The apparent mass shift could be measured by comparing with the ZZ* channel, where the shift is much smaller. It might be possible to measure the shift more accurately by exploiting its strong dependence on the Higgs transverse momentum. PMID:24074073

  6. Width of the ? meson in nuclear matter

    International Nuclear Information System (INIS)

    The ratios of the cross sections for ?-meson production induced by 2.83-GeV protons on Cu, Ag, and Au nuclei to the respective cross section for C nuclei were measured at the ANKE-COSY facility in the momentum range of 0.6-1.6 GeV/c and the angular range of 0°-8°. The product ? mesons were identified by their decay ? ? K+K-. The procedure used to separate kaon pairs was described in detail, and all sources of the background and their contribution to the resulting error in the values found for the above cross-section ratios were analyzed. The A dependence of the cross section for ?-meson production was shown to obey the A0.56±0.03 law. The total width of the ? meson at a normal nuclear density was extracted from a comparison of the measured cross-section ratios with the results of calculations based on two theoretical models. The resulting width value exceeds substantially both the vacuum width and the width expected in the absence of the nuclear-matter effect on the properties of the ? meson.

  7. Morita Equivalence of Noncommutative Supertori

    CERN Document Server

    Chang-Young, Ee; Nakajima, Hiroaki

    2009-01-01

    In this paper we study an extension of the Morita equivalence of noncommutative tori to the supersymmetric case. We restrict our investigation mainly to the two dimensional case in which noncommutative supertori have been constructed recently. Our main focus is to know how the supersymmetry affect the symmetry relations giving the Morita equivalence in the bosonic noncommutative tori case. It turns out that the structure of the symmetry group acting on the noncommutativity parameters yielding the Morita equivalence remains intact but its field become supersymmetric having both body and soul parts. The extension of the Morita equivalence to the higher dimensional case could not be carried out due to lack of complete understanding of the classification and construction of all possible higher dimensional noncommutative supertori. However, even in the higher dimensional case there seems to be a certain indication that the structure of the symmetry group yielding Morita equivalence remains unchanged from the boson...

  8. Singular Equivalence of Morita Type with Level

    OpenAIRE

    Wang, Zhengfang

    2014-01-01

    We generalize the notion of stable equivalence of Morita type and define what is called "singular equivalence of Morita type with level". Such an equivalence of induces an equivalence between singular categories. We will also prove that a derived equivalence of standard type induces a singular equivalence of Morita type with level.

  9. Concurrent Supermassive Black Hole and Galazy Growth: Linking Environment and Nuclear Activity in Zeta Equals 2.23 H Alpha Emitters

    Science.gov (United States)

    Lehmer, B. D.; Lucy, A. B.; Alexander, D. M.; Best, P. N.; Geach, J. E.; Harrison, C. M.; Hornschemeier, A. E.; Matsuda, Y.; Mullaney, J. R.; Smail, Ian; Sobral, D.; Swinbank, A. M.

    2013-01-01

    We present results from an approximately equal 100 ks Chandra observation of the 2QZ Cluster 1004+00 structure at z = 2.23 (hereafter 2QZ Clus). 2QZ Clus was originally identified as an overdensity of four optically-selected QSOs at z = 2.23 within a 15 × 15 arcmin square region. Narrow-band imaging in the near-IR (within the K band) revealed that the structure contains an additional overdensity of 22 z = 2.23 H alpha-emitting galaxies (HAEs), resulting in 23 unique z = 2.23 HAEs/QSOs (22 within the Chandra field of view). Our Chandra observations reveal that three HAEs in addition to the four QSOs harbor powerfully accreting supermassive black holes (SMBHs), with 2-10 keV luminosities of approximately equal (8-60) × 10(exp 43) erg s(exp-1) and X-ray spectral slopes consistent with unobscured active galactic nucleus (AGN). Using a large comparison sample of 210 z = 2.23 HAEs in the Chandra-COSMOS field (C-COSMOS), we find suggestive evidence that the AGN fraction increases with local HAE galaxy density. The 2QZ Clus HAEs reside in a moderately overdense environment (a factor of approximately equal 2 times over the field), and after excluding optically-selected QSOs, we find that the AGN fraction is a factor of approximately equal 3.5(+3.8/ -2.2) times higher than C-COSMOS HAEs in similar environments. Using stacking analyses of the Chandra data and Herschel SPIRE observations at 250micrometers, we respectively estimate mean SMBH accretion rates ( M(BH)) and star formation rates (SFRs) for the 2QZ Clus and C-COSMOS samples. We find that the mean 2QZ Clus HAE stacked X-ray luminosity is QSO-like (L(2-10 keV) approximately equal [6-10] × 10(exp 43) erg s(exp -1)), and the implied M(BH)/SFR approximately equal (1.6-3.2) × 10(exp -3) is broadly consistent with the local M(BH)/Stellar Mass relation and z approximately equal 2 X-ray selected AGN. In contrast, the C-COSMOS HAEs are on average an order of magnitude less X-ray luminous and have M(BH)/SFR approximately equal (0.2-0.4) × 10(exp -3), somewhat lower than the local MBH/M relation, but comparable to that found for z approximately equal 1-2 star-forming galaxies with similar mean X-ray luminosities. We estimate that a periodic QSO phase with duty cycle approximately 2%-8% would be sufficient to bring star-forming galaxies onto the local M(BH)/Stellar Mass relation. This duty cycle is broadly consistent with the observed C-COSMOS HAE AGN fraction (Approximately equal 0.4%-2.3%) for powerful AGN with LX approximately greater than 10(exp 44) erg s(exp -1). Future observations of 2QZ Clus will be needed to identify key factors responsible for driving the mutual growth of the SMBHs and galaxies.

  10. CONCURRENT SUPERMASSIVE BLACK HOLE AND GALAXY GROWTH: LINKING ENVIRONMENT AND NUCLEAR ACTIVITY IN z = 2.23 H{alpha} EMITTERS

    Energy Technology Data Exchange (ETDEWEB)

    Lehmer, B. D.; Hornschemeier, A. E. [Department of Physics and Astronomy, Johns Hopkins University, Homewood Campus, Baltimore, MD 21218 (United States); Lucy, A. B. [NASA Goddard Space Flight Centre, Code 662, Greenbelt, MD 20771 (United States); Alexander, D. M.; Harrison, C. M.; Mullaney, J. R.; Swinbank, A. M. [Department of Physics, Durham University, South Road, Durham DH1 3LE (United Kingdom); Best, P. N. [SUPA, Institute for Astronomy, Royal Observatory of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Geach, J. E. [Department of Physics, McGill University, 3600 rue University, Montreal, Quebec H3A 2T8 (Canada); Matsuda, Y. [Chile Observatory, National Astronomical Observatory of Japan, Tokyo 181-8588 (Japan); Smail, Ian [Institute for Computational Cosmology, Durham University, South Road, Durham DH1 3LE (United Kingdom); Sobral, D. [Leiden Observatory, Leiden University, P.O. Box 9513, NL-2300 RA Leiden (Netherlands)

    2013-03-10

    We present results from a Almost-Equal-To 100 ks Chandra observation of the 2QZ Cluster 1004+00 structure at z = 2.23 (hereafter 2QZ Clus). 2QZ Clus was originally identified as an overdensity of four optically-selected QSOs at z = 2.23 within a 15 Multiplication-Sign 15 arcmin{sup 2} region. Narrow-band imaging in the near-IR (within the K band) revealed that the structure contains an additional overdensity of 22 z = 2.23 H{alpha}-emitting galaxies (HAEs), resulting in 23 unique z = 2.23 HAEs/QSOs (22 within the Chandra field of view). Our Chandra observations reveal that three HAEs in addition to the four QSOs harbor powerfully accreting supermassive black holes (SMBHs), with 2-10 keV luminosities of Almost-Equal-To (8-60) Multiplication-Sign 10{sup 43} erg s{sup -1} and X-ray spectral slopes consistent with unobscured active galactic nucleus (AGN). Using a large comparison sample of 210 z = 2.23 HAEs in the Chandra-COSMOS field (C-COSMOS), we find suggestive evidence that the AGN fraction increases with local HAE galaxy density. The 2QZ Clus HAEs reside in a moderately overdense environment (a factor of Almost-Equal-To 2 times over the field), and after excluding optically-selected QSOs, we find that the AGN fraction is a factor of Almost-Equal-To 3.5{sup +3.8}{sub -2.2} times higher than C-COSMOS HAEs in similar environments. Using stacking analyses of the Chandra data and Herschel SPIRE observations at 250 {mu}m, we respectively estimate mean SMBH accretion rates ( M-dot{sub BH}) and star formation rates (SFRs) for the 2QZ Clus and C-COSMOS samples. We find that the mean 2QZ Clus HAE stacked X-ray luminosity is QSO-like (L{sub 2-10{sub keV}} Almost-Equal-To [6-10] Multiplication-Sign 10{sup 43} erg s{sup -1}), and the implied M-dot{sub BH}/SFR Almost-Equal-To (1.6-3.2) Multiplication-Sign 10{sup -3} is broadly consistent with the local M{sub BH}/M{sub *} relation and z Almost-Equal-To 2 X-ray selected AGN. In contrast, the C-COSMOS HAEs are on average an order of magnitude less X-ray luminous and have M-dot{sub BH}/SFR Almost-Equal-To (0.2-0.4) Multiplication-Sign 10{sup -3}, somewhat lower than the local M{sub BH}/M{sub *} relation, but comparable to that found for z Almost-Equal-To 1-2 star-forming galaxies with similar mean X-ray luminosities. We estimate that a periodic QSO phase with duty cycle Almost-Equal-To 2%-8% would be sufficient to bring star-forming galaxies onto the local M{sub BH}/M{sub *} relation. This duty cycle is broadly consistent with the observed C-COSMOS HAE AGN fraction ( Almost-Equal-To 0.4%-2.3%) for powerful AGN with L{sub X} {approx}> 10{sup 44} erg s{sup -1}. Future observations of 2QZ Clus will be needed to identify key factors responsible for driving the mutual growth of the SMBHs and galaxies.

  11. Stimulus equivalence and supplemental measures on equivalence relations

    OpenAIRE

    Moksness, Anne-marie

    2012-01-01

    The present article introduces stimulus equivalence research as an experimental analysis on how previously unrelated stimuli can generate a specific pattern of responding without being directly taught. Murray Sidman and colleagues set forth that stimulus equivalence should be considered as a basic process in line with other behavioral processes such as reinforcement, discrimination, or generalization. In specific, a direct outcome of the reinforcement contingencies that have previously been i...

  12. What is correct: equivalent dose or dose equivalent

    International Nuclear Information System (INIS)

    In Croatian language some physical quantities in radiation protection dosimetry have not precise names. Consequently, in practice either terms in English or mathematical formulas are used. The situation is even worse since the Croatian language only a limited number of textbooks, reference books and other papers are available. This paper compares the concept of ''dose equivalent'' as outlined in International Commission on Radiological Protection (ICRP) recommendations No. 26 and newest, conceptually different concept of ''equivalent dose'' which is introduced in ICRP 60. It was found out that Croatian terminology is both not uniform and unprecise. For the term ''dose equivalent'' was, under influence of Russian and Serbian languages, often used as term ''equivalent dose'' even from the point of view of ICRP 26 recommendations, which was not justified. Unfortunately, even now, in Croatia the legal unit still ''dose equivalent'' defined as in ICRP 26, but the term used for it is ''equivalent dose''. Therefore, in Croatian legislation a modified set of quantities introduced in ICRP 60, should be incorporated as soon as possible

  13. Morita equivalence of noncommutative supertori

    International Nuclear Information System (INIS)

    In this paper we study the extension of Morita equivalence of noncommutative tori to the supersymmetric case. The structure of the symmetry group yielding Morita equivalence appears to be intact but its parameter field becomes supersymmetrized having both body and soul parts. Our result is mainly in the two dimensional case in which noncommutative supertori have been constructed recently: The group SO(2,2,VZ0), where VZ0 denotes Grassmann even number whose body part belongs to Z, yields Morita equivalent noncommutative supertori in two dimensions.

  14. CMS presents new boundary of Higgs width

    CERN Multimedia

    Katarina Anthony

    2014-01-01

    At last year's Moriond conference, CERN physicists announced the retirement of the "Higgs-like" particle and the arrival of "boson, Higgs boson". Now, one year later, at the same session in the same conference, physicists are back with more exciting news about the famed particle. This time: the best constraint yet of the Higgs Boson “width”, a parameter that determines the particle’s lifetime.   Rencontres de Moriond 2014. As a key indicator for new physics, the Higgs “width” has long been on the LHC "to-do" list. Now less than two years post-discovery, the CMS experiment has gotten the closest yet to pinning it down, constraining the parameter to < 17 MeV with 95% confidence. This result is some two orders of magnitude better than previous limits: stronger evidence that this boson looks like the Standard Model Higgs boson. "It's been exciting to see how wel...

  15. Circumscribing constant-width bodies with polytopes

    CERN Document Server

    Kuperberg, G

    1999-01-01

    Makeev conjectured that every constant-width body is inscribed in the dual difference body of a regular simplex. We prove that homologically, there are an odd number of such circumscribing bodies in dimension 3, and therefore geometrically there is at least one. We show that the homological answer is zero in higher dimensions, a result which is inconclusive for the geometric question. We also give a partial generalization involving affine circumscription of strictly convex bodies.

  16. Habitat width along a latitudinal gradient

    OpenAIRE

    Stauffer, D.; Schulze, C.; Rohde, K.

    2006-01-01

    We use the Chowdhury ecosystem model, one of the most complex agent-based ecological models, to test the latitude-niche breadth hypothesis, with regard to habitat width, i.e., whether tropical species generally have narrower habitats than high latitude ones. Application of the model has given realistic results in previous studies on latitudinal gradients in species diversity and Rapoport's rule. Here we show that tropical species with sufficient vagility and time to spread i...

  17. Determination of the ?(1S) leptonic width

    International Nuclear Information System (INIS)

    Analyzing the data recorded with the MD-1 detector operated at the VEPP-4 storage ring we have determined the ?(1S) resonance leptonic partial width and mass. We find ?ee=1.29±0.03±0.03 keV, M=9460.59±0.09±0.05 MeV/c2. This new value of the ?(1S) mass should supersede the previously published value [11] based on almost the same statistics. (orig.)

  18. Pion Decay Widths of D mesons

    OpenAIRE

    Henriksson, K. O. E.; Lahde, T. A.; Nyfalt, C. J.; Riska, D. O.

    2000-01-01

    The pionic decay rates of the excited $L=0,1$ $D$ mesons are calculated with a Hamiltonian model within the framework of the covariant Blankenbecler-Sugar {equation.} The interaction between the light quark and charm antiquark is described by a linear scalar confining and a screened one-gluon exchange interaction. The decay widths of the $D^*$ mesons obtain a contribution from the exchange current that is associated with the linear scalar confining interaction. If this contr...

  19. Radiative widths of K and rho mesons

    International Nuclear Information System (INIS)

    The dissociation of K and ? mesons in the nuclear Coulomb field has been studied. Results are: GAMMA(rho???) = 67 +- 7 KeV., GAMMA(K*(890)?K?) = 60 +- 15 KeV; and the observation of Coulomb excitation of the following states: K*(1420,1700),A2,A1,B. The measured widths are in rough agreement with a simple quark model

  20. First Digit Distribution of Hadron Full Width

    OpenAIRE

    Shao, Lijing; Ma, Bo-qiang

    2010-01-01

    A phenomenological law, called Benford's law, states that the occurrence of the first digit, i.e., $1,2,...,9$, of numbers from many real world sources is not uniformly distributed, but instead favors smaller ones according to a logarithmic distribution. We investigate, for the first time, the first digit distribution of the full widths of mesons and baryons in the well defined science domain of particle physics systematically, and find that they agree excellently with the B...

  1. Tissue Engineered Human Skin Equivalents

    Directory of Open Access Journals (Sweden)

    Zheng Zhang

    2012-01-01

    Full Text Available Human skin not only serves as an important barrier against the penetration of exogenous substances into the body, but also provides a potential avenue for the transport of functional active drugs/reagents/ingredients into the skin (topical delivery and/or the body (transdermal delivery. In the past three decades, research and development in human skin equivalents have advanced in parallel with those in tissue engineering and regenerative medicine. The human skin equivalents are used commercially as clinical skin substitutes and as models for permeation and toxicity screening. Several academic laboratories have developed their own human skin equivalent models and applied these models for studying skin permeation, corrosivity and irritation, compound toxicity, biochemistry, metabolism and cellular pharmacology. Various aspects of the state of the art of human skin equivalents are reviewed and discussed.

  2. Tissue Engineered Human Skin Equivalents

    OpenAIRE

    Zheng Zhang; Michniak-kohn, Bozena B.

    2012-01-01

    Human skin not only serves as an important barrier against the penetration of exogenous substances into the body, but also provides a potential avenue for the transport of functional active drugs/reagents/ingredients into the skin (topical delivery) and/or the body (transdermal delivery). In the past three decades, research and development in human skin equivalents have advanced in parallel with those in tissue engineering and regenerative medicine. The human skin equivalents are used commerc...

  3. Equivalence in Answer Set Programming

    OpenAIRE

    Osorio, M.; Pe?rez, J. A. N.; Arrazola, J.

    2002-01-01

    We study the notion of strong equivalence between two Answer Set programs and we show how some particular cases of testing strong equivalence between programs can be reduced to verify if a formula is a theorem in intuitionistic or classical logic. We present some program transformations for disjunctive programs, which can be used to simplify the structure of programs and reduce their size. These transformations are shown to be of interest for both computational and theoretical reasons. Then w...

  4. ECC water spreading width for flat plate

    International Nuclear Information System (INIS)

    To investigate the characteristics of water jet spreading width induced by Direct Vessel Injection(DVI), a steady state and separate effect test focusing on the effect of the downcomer curvature was performed using a rectangular flat-plate air-water open channel test facility. Comparative tests using various scaled diameter(D) of water jet nozzle, channel gap(W), water jet velocity(VJET), and forced cross air-flow(Vc) on the water film are performed for the Korean Next Generation Reactor(KNGR) during the late reflood phase of LBLOCA. A simplified and visible thin acryl plates were used. The air-water channel has a nearly full height in height between DVI and coldleg. The channel gap and the diameter of water injection nozzle have scaled ratios of 1/50 ? 1/10 by volume scaling method. The cross flow is introduced in the airwater channel to investigate the cross flow effects on the ECC water jet spreading width. The major parameters measured in the experiments are the film width of ECC water, the shifted degree of water film boundary by the cross air flow, and the attachment liquid fraction to total injected water in the region of front plate against water injected wall plate. It was found out that (1) If the test scale is increased, for the typical film spreading width without any cross flow, the film width is linearly increased at the bottom of air-water channel except at the top of film. (2) If the cross flow is induced on the liquid film for flow is induced on the liquid film for the test scale of 1:51.68, the highly shifted film shape is formed (3) If the test scale and the water injection velocity are increased, the attachment ratio of liquid on the front plate is sharply increased. (4) The attachment ratio of liquid on the front plate is strongly increased by cross flow. In the case of 9.52 scaled test, the attachment ratio of liquid is affected by both the cross flow and the water injection velocity

  5. A high spatial resolution X-ray and H-alpha study of hot gas in the halos of star-forming disk galaxies. I. Spatial and spectral properties of the diffuse X-ray emission

    CERN Document Server

    Strickland, D K; Colbert, E J M; Hoopes, C G; Weaver, K A

    2003-01-01

    We present arcsecond resolution Chandra X-ray and ground-based optical H-alpha imaging of a sample of ten edge-on star-forming disk galaxies (seven starburst and three ``normal'' spiral galaxies), a sample which covers the full range of star-formation intensity found in disk galaxies. We use the unprecedented spatial resolution of the Chandra X-ray observatory to robustly remove point sources, and hence obtain the X-ray properties of the diffuse thermal emission alone. The X-ray observations are combined with comparable-resolution H-alpha and R-band imaging, and presented as a mini-atlas of images on a common spatial and surface brightness scale. The vertical distribution of the halo-region X-ray surface brightness is best described as an exponential, with the observed scale heights lying in the range H_eff = 2 -- 4 kpc. The ACIS X-ray spectra of extra-planar emission from all these galaxies can be fit with a common two-temperature spectral model with an enhanced alpha-to-iron element ratio. This is consisten...

  6. Complex Variability of the H$\\alpha$ Emission Line Profile of the T Tauri Binary System KH 15D: The Influence of Orbital Phase, Occultation by the Circumbinary Disk, and Accretion Phenomenae

    CERN Document Server

    Hamilton, Catrina M; Mundt, Reinhard; Herbst, William; Winn, Joshua N

    2012-01-01

    We have obtained 48 high resolution echelle spectra of the pre-main sequence eclipsing binary system KH~15D (V582 Mon, P = 48.37 d, $e$ $\\sim$ 0.6, M$_{A}$ = 0.6 M$_{\\odot}$, M$_{B}$ = 0.7 M$_{\\odot}$). The eclipses are caused by a circumbinary disk seen nearly edge on, which at the epoch of these observations completely obscured the orbit of star B and a large portion of the orbit of star A. The spectra were obtained over five contiguous observing seasons from 2001/2002 to 2005/2006 while star A was fully visible, fully occulted, and during several ingress and egress events. The H$\\alpha$ line profile shows dramatic changes in these time series data over timescales ranging from days to years. A fraction of the variations are due to "edge effects" and depend only on the height of star A above or below the razor sharp edge of the occulting disk. Other observed variations depend on the orbital phase: the H$\\alpha$ emission line profile changes from an inverse P Cygni type profile during ingress to an enhanced d...

  7. Seismology of solar oscillation line widths

    International Nuclear Information System (INIS)

    Recent measurements of line widths of solar p-modes are compared with damping rates computed under several different assumptions. There is reasonable agreement with a calculation taking some account of perturbations in the convective fluxes induced by the oscillations, whereas calculations neglecting these flux perturbations are further from the observations. This opens up the prospect of using observations of solar oscillations to test theories of time-dependent convection. The results should be of importance to studies of other types of pulsating stars. 26 refs

  8. Histograms, Bin Widths, and Cross Validation

    Science.gov (United States)

    Lane, David M.

    Created by David Lane of Rice University, this applet demonstrates how a histogram is affected by bin width and starting point of first bin. It also illustrates cross-validation criterion for assessing histograms. The author structures the lesson in this fashion: instruction, descriptions of datasets and finally, exercises. Additionally, the applet works with six different data sets. These consist of: Old Faithful, Sosa home, Sosa away, arm strength, grip strength and a choice of entering your own data. Overall, this is a nice hands-on approach to learning this statistical method.

  9. Equivalent linearization of nonlinear forces

    Science.gov (United States)

    Meng, Guang; Xue, Zhongqing

    1987-07-01

    A method used for equivalent linearization of the two orthogonal squeeze-film forces is extended here to the general case of n degrees of freedom and n components of nonlinear forces, and the expressions for equivalent linear coefficients are derived. Nonlinear forces can be linearized by the methods of Fourier expansion, active and reactive powers, or mean-square error. The n components of nonlinear forces can all be expressed formally as the sum of an average force, a linear spring force, and a linear damping force. This paper also gives a flow chart for calculating the steady-state responses of a nonlinear system with many degrees of freedom, using the method of equivalent linearization. The resulting saving in computation time is demonstrated by a numerical example of a flexible rotor-bearing system with a noncentralized squeeze-film damper.

  10. Equivalent linearization of impacting structures

    International Nuclear Information System (INIS)

    Complex industrial structures are generally divided in several substructures. Even if the global behavior of the structure may by considered as linear, some substructures present local nonlinearities like impacts, sliding, or plasticity. To study the response of the whole structure the usual method consists of replacing the nonlinear substructures by linear models. The effect of the substructure is made equivalent to the nonlinear effect of the real substructure. Such equivalent models are called Linear Equivalent Models (LEM). This paper is mainly focused on the seismic behaviour of structures impacting on supports with gaps (for example pipes, steam generator etc...). Classical approaches to determine LEM consist generally in replacing the nonlinear support by a spring which stiffness is a function of the gap value and the excitation level. The limitations of such method will be identified in the case of a 1 degree of freedom (DOF) nonlinear oscillator. A new principle of LEM will be proposed and applied to this lDOF structure

  11. The first measured Mn I Stark widths

    Energy Technology Data Exchange (ETDEWEB)

    Sreckovic, A. [Faculty of Physics, University of Belgrade, Studentski trg 12-16, P.O. Box 368, 11000 Belgrade (Serbia); Nikolic, Z. [Faculty of Physics, University of Belgrade, Studentski trg 12-16, P.O. Box 368, 11000 Belgrade (Serbia); Bukvic, S. [Faculty of Physics, University of Belgrade, Studentski trg 12-16, P.O. Box 368, 11000 Belgrade (Serbia); Djenize, S. [Faculty of Physics, University of Belgrade, Studentski trg 12-16, P.O. Box 368, 11000 Belgrade (Serbia)]. E-mail: steva@ff.bg.ac.yu

    2007-07-15

    The shapes of the astrophysically interesting neutral manganese (Mn I) resonance spectral lines (403.075, 403.306, 403.448, 279.481, 279.826 and 280.108nm) have been observed together with six other prominent Mn I lines in the laboratory helium plasma at a 47000K electron temperature and 6.6x10{sup 22}m{sup -3} electron density. With these plasma parameters the Stark broadening has been found to be an important mechanism in the Mn I line shape formation. Our measured Mn I Stark widths (W) are the first data in the literature. Stark widths are compared with line hyperfine structure splittings ({delta}{sub hfs}). At above mentioned helium plasma conditions the line broadening due to hyperfine structure splitting of the lines is less than that of the Stark and Doppler broadening for the case of the Mn I lines under investigation. We estimate that at electron densities below 10{sup 20}m{sup -3} and electron temperatures below 4000K the components in the hyperfine structure play an important role in the mentioned Mn I line shape formation.

  12. The first measured Mn I Stark widths

    International Nuclear Information System (INIS)

    The shapes of the astrophysically interesting neutral manganese (Mn I) resonance spectral lines (403.075, 403.306, 403.448, 279.481, 279.826 and 280.108nm) have been observed together with six other prominent Mn I lines in the laboratory helium plasma at a 47000K electron temperature and 6.6x1022m-3 electron density. With these plasma parameters the Stark broadening has been found to be an important mechanism in the Mn I line shape formation. Our measured Mn I Stark widths (W) are the first data in the literature. Stark widths are compared with line hyperfine structure splittings (?hfs). At above mentioned helium plasma conditions the line broadening due to hyperfine structure splitting of the lines is less than that of the Stark and Doppler broadening for the case of the Mn I lines under investigation. We estimate that at electron densities below 1020m-3 and electron temperatures below 4000K the components in the hyperfine structure play an important role in the mentioned Mn I line shape formation

  13. Pulse width modulation inverter with battery charger

    Science.gov (United States)

    Slicker, James M. (Union Lake, MI)

    1985-01-01

    An inverter is connected between a source of DC power and a three-phase AC induction motor, and a microprocessor-based circuit controls the inverter using pulse width modulation techniques. In the disclosed method of pulse width modulation, both edges of each pulse of a carrier pulse train are equally modulated by a time proportional to sin .theta., where .theta. is the angular displacement of the pulse center at the motor stator frequency from a fixed reference point on the carrier waveform. The carrier waveform frequency is a multiple of the motor stator frequency. The modulated pulse train is then applied to each of the motor phase inputs with respective phase shifts of 120.degree. at the stator frequency. Switching control commands for electronic switches in the inverter are stored in a random access memory (RAM) and the locations of the RAM are successively read out in a cyclic manner, each bit of a given RAM location controlling a respective phase input of the motor. The DC power source preferably comprises rechargeable batteries and all but one of the electronic switches in the inverter can be disabled, the remaining electronic switch being part of a "flyback" DC-DC converter circuit for recharging the battery.

  14. Pulse width modulation inverter with battery charger

    Science.gov (United States)

    Slicker, James M. (Inventor)

    1985-01-01

    An inverter is connected between a source of DC power and a three-phase AC induction motor, and a microprocessor-based circuit controls the inverter using pulse width modulation techniques. In the disclosed method of pulse width modulation, both edges of each pulse of a carrier pulse train are equally modulated by a time proportional to sin .theta., where .theta. is the angular displacement of the pulse center at the motor stator frequency from a fixed reference point on the carrier waveform. The carrier waveform frequency is a multiple of the motor stator frequency. The modulated pulse train is then applied to each of the motor phase inputs with respective phase shifts of 120.degree. at the stator frequency. Switching control commands for electronic switches in the inverter are stored in a random access memory (RAM) and the locations of the RAM are successively read out in a cyclic manner, each bit of a given RAM location controlling a respective phase input of the motor. The DC power source preferably comprises rechargeable batteries and all but one of the electronic switches in the inverter can be disabled, the remaining electronic switch being part of a flyback DC-DC converter circuit for recharging the battery.

  15. Approximation of reduced width amplitude and application to cluster decay width

    Science.gov (United States)

    Kanada-En'yo, Yoshiko; Suhara, Tadahiro; Taniguchi, Yasutaka

    2014-07-01

    We propose a simple method to approximately evaluate the reduced width amplitude (RWA) of a two-body spinless cluster channel using the norm overlap with the Brink-Bloch cluster wave function at the channel radius. The applicability of the present approximation is tested for the ^{16}{O} + ? channel in ^{20}Ne as well as the ? + ? channel in ^8Be. The approximation is found to be reasonable for evaluating the RWA for states near the threshold energy and it is useful to estimate the ? -decay width of resonance states. The approximation is also applied to ^9Li, and the partial decay width of the ^6{He}(0^+_1)+t channel is discussed.

  16. Approximation of reduced width amplitude and application to cluster decay width

    CERN Document Server

    Kanada-En'yo, Yoshiko; Taniguchi, Yasutaka

    2014-01-01

    We propose a simple method to approximately evaluate reduced width amplitude (RWA) of a two-body spinless cluster channel using the norm overlap with the Brink-Bloch cluster wave function at the channel radius. The applicability of the present approximation is tested for the $^{16}$O+$\\alpha$ channel in $^{20}$Ne as well as the $\\alpha$+$\\alpha$ channel in $^8$Be. The approximation is found to be reasonable to evaluate the RWA for states near the threshold energy and it is useful to estimate the $\\alpha$-decay width of resonance states. The approximation is also applied to $^9$Li, and the partial decay width of the $^6$He($0^+_1$)+$t$ channel is discussed.

  17. A characterization of covering equivalence

    OpenAIRE

    Pan, Hao; Sun, Zhi-wei

    2004-01-01

    Let A={a_s(mod n_s)}_{s=1}^k and B={b_t(mod m_t)}_{t=1}^l be two systems of residue classes. If |{1\\le s\\le k: x=a_s (mod n_s)}| and |{1\\le t\\le l: x=b_t (mod m_t)}| are equal for all integers x, then A and B are said to be covering equivalent. In this paper we characterize the covering equivalence in a simple and new way. Using the characterization we partially confirm a conjecture of R. L. Graham and K. O'Bryant.

  18. Expanding shell and P Cygni profiles of 27 Canis Majoris

    International Nuclear Information System (INIS)

    H-alpha and He I profiles of 27 CMa obtained between January 1985 and February 1989 are presented. Velocities of blue absorption and red emission components of H-alpha were different from that of He I, suggesting that the regions of formation of H-alpha and He I were different in the expanding shell of 27 CMa. Velocities of all the components of H-alpha were variable between April 16 and 18, 1989. But, from April 18, when the blue emission velocities were almost unchanged, the blue absorption and red emission velocities were decreasing and those for He I components were increasing. Equivalent widths of blue emission components of He I lines were almost constant during the observational interval, while red emission strengths of H-alpha profile displayed weak variations between April 16 and 26. He I and H-alpha profiles clearly show that 27 CMa has entered into a new shell phase. 22 refs

  19. Equivalence classes for gauge theories

    OpenAIRE

    Gomes, M. A. M.; Landim, R. R.

    2006-01-01

    In this paper we go deep into the connection between duality and fields redefinition for general bilinear models involving the 1-form gauge field $A$. A duality operator is fixed based on "gauge embedding" procedure. Dual models are shown to fit in equivalence classes of models with same fields redefinitions.

  20. Equivalence classes for gauge theories

    CERN Document Server

    Gomes, M A M

    2005-01-01

    In this paper we go deep into the connection between duality and fields redefinition for general bilinear models involving the 1-form gauge field $A$. A duality operator is fixed based on "gauge embedding" procedure. Dual models are shown to fit in equivalence classes of models with same fields redefinitions.

  1. Equivalence classes for gauge theories

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, M.A.M.; Landim, R.R. [Universidade Federal do Ceara, Dept. de Fisica, Ceara (Brazil)

    2005-06-01

    In this paper we go deep into the connection between duality and fields redefinition for general bilinear models involving the 1-form gauge field A. A duality operator is fixed based on a 'gauge embedding' procedure. Dual models are shown to fit in equivalence classes of models with the same fields re-definitions. (authors)

  2. Equivalence classes for gauge theories

    International Nuclear Information System (INIS)

    In this paper we go deep into the connection between duality and fields redefinition for general bilinear models involving the 1-form gauge field A. A duality operator is fixed based on a 'gauge embedding' procedure. Dual models are shown to fit in equivalence classes of models with the same fields re-definitions. (authors)

  3. Band Width Selection for High Dimensional Covariance Matrix Estimation

    OpenAIRE

    Qiu, Yumou; Chen, Song Xi

    2014-01-01

    The banding estimator of Bickel and Levina (2008a) and its tapering version of Cai, Zhang and Zhou (2010), are important high dimensional covariance estimators. Both estimators require choosing a band width parameter. We propose a band width selector for the banding covariance estimator by minimizing an empirical estimate of the expected squared Frobenius norms of the estimation error matrix. The ratio consistency of the band width selector to the underlying band width is esta...

  4. A comparative study on the relationship between inter alar width, and inter commissural width on circumferential arc width of maxillary anterior teeth in different age groups.

    Science.gov (United States)

    Kurien, Anjana; Cherian, K P; Mhatre, Shirley; Tharakan, Renji George

    2014-12-01

    This study was done to determine the relationship between interalar width and inter commissural width on circumferential arc width of maxillary anterior teeth in dentulous subjects between the age groups of 20-50 years. The study involved 300 subjects, in whom measurements were made from the distal aspect of each maxillary canine, across the facial surfaces of the six anterior teeth, using brass wire and a Vernier calliper. Interalar and inter commissural width were recorded after placing two points and measured with a Vernier calliper. Results were statistically analyzed using unpaired t test, Kolmogorov-Smirnov and Pearson's correlation coefficient test. This study confirmed the reliability of interalar width to determine the circumferential arc width which can be used as a reference in edentulous patients. PMID:25489157

  5. Direct measurement of the W boson width

    Energy Technology Data Exchange (ETDEWEB)

    Abazov, V.M.; /Dubna, JINR; Abbott, B.; /Oklahoma U.; Abolins, M.; /Michigan State U.; Acharya, B.S.; /Tata Inst.; Adams, M.; /Illinois U., Chicago; Adams, T.; /Florida State U.; Aguilo, E.; /Alberta U. /Simon Fraser U. /McGill U.; Ahsan, M.; /Kansas State U.; Alexeev, G.D.; /Dubna, JINR; Alkhazov, G.; /St. Petersburg, INP; Alton, A.; /Michigan U. /Northeastern U.

    2009-09-01

    We present a direct measurement of the width of the W boson using the shape of the transverse mass distribution of W {yields} e{nu} candidates selected in 1 fb{sup -1} of data collected with the D0 detector at the Fermilab Tevatron collider in p{bar p} collisions at {radical}s = 1.96 TeV. We use the same methods and data sample that were used for our recently published W boson mass measurement, except for the modeling of the recoil, which is done with a new method based on a recoil library. Our result, 2.028 {+-} 0.072 GeV, is in agreement with the predictions of the standard model and is the most precise direct measurement result from a single experiment to date.

  6. Direct measurement of the W boson width.

    Science.gov (United States)

    Abazov, V M; Abbott, B; Abolins, M; Acharya, B S; Adams, M; Adams, T; Aguilo, E; Ahsan, M; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Ancu, L S; Andeen, T; Anzelc, M S; Aoki, M; Arnoud, Y; Arov, M; Arthaud, M; Askew, A; Asman, B; Atramentov, O; Avila, C; BackusMayes, J; Badaud, F; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, S; Barberis, E; Barfuss, A-F; Bargassa, P; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Beale, S; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Benitez, J A; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Blazey, G; Blessing, S; Bloom, K; Boehnlein, A; Boline, D; Bolton, T A; Boos, E E; Borissov, G; Bose, T; Brandt, A; Brock, R; Brooijmans, G; Bross, A; Brown, D; Bu, X B; Buchholz, D; Buehler, M; Buescher, V; Bunichev, V; Burdin, S; Burnett, T H; Buszello, C P; Calfayan, P; Calpas, B; Calvet, S; Cammin, J; Carrasco-Lizarraga, M A; Carrera, E; Carvalho, W; Casey, B C K; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chandra, A; Cheu, E; Cho, D K; Cho, S W; Choi, S; Choudhary, B; Christoudias, T; Cihangir, S; Claes, D; Clutter, J; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M-C; Cutts, D; Cwiok, M; Das, A; Davies, G; De, K; de Jong, S J; De La Cruz-Burelo, E; DeVaughan, K; Déliot, F; Demarteau, M; Demina, R; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Dominguez, A; Dorland, T; Dubey, A; Dudko, L V; Duflot, L; Duggan, D; Duperrin, A; Dutt, S; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Eno, S; Escalier, M; Evans, H; Evdokimov, A; Evdokimov, V N; Facini, G; Ferapontov, A V; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fortner, M; Fox, H; Fuess, S; Gadfort, T; Galea, C F; Garcia-Bellido, A; Gavrilov, V; Gay, P; Geist, W; Geng, W; Gerber, C E; Gershtein, Y; Gillberg, D; Ginther, G; Golovanov, G; Gómez, B; Goussiou, A; Grannis, P D; Greder, S; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, Ph; Grivaz, J-F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guo, F; Guo, J; Gutierrez, G; Gutierrez, P; Haas, A; Haefner, P; Hagopian, S; Haley, J; Hall, I; Hall, R E; Han, L; Harder, K; Harel, A; Hauptman, J M; Hays, J; Hebbeker, T; Hedin, D; Hegeman, J G; Heinson, A P; Heintz, U; Hensel, C; Heredia-De La Cruz, I; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hoang, T; Hobbs, J D; Hoeneisen, B; Hohlfeld, M; Hossain, S; Houben, P; Hu, Y; Hubacek, Z; Huske, N; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jakobs, K; Jamin, D; Jesik, R; Johns, K; Johnson, C; Johnson, M; Johnston, D; Jonckheere, A; Jonsson, P; Juste, A; Kajfasz, E; Karmanov, D; Kasper, P A; Katsanos, I; Kaushik, V; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Y N; Khatidze, D; Kirby, M H; Kirsch, M; Klima, B; Kohli, J M; Konrath, J-P; Kozelov, A V; Kraus, J; Kuhl, T; Kumar, A; Kupco, A; Kurca, T; Kuzmin, V A; Kvita, J; Lacroix, F; Lam, D; Lammers, S; Landsberg, G; Lebrun, P; Lee, H S; Lee, W M; Leflat, A; Lellouch, J; Li, L; Li, Q Z; Lietti, S M; Lim, J K; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Y; Liu, Z; Lobodenko, A; Lokajicek, M; Love, P; Lubatti, H J; Luna-Garcia, R; Lyon, A L; Maciel, A K A; Mackin, D; Mättig, P; Magaña-Villalba, R; Mal, P K; Malik, S; Malyshev, V L; Maravin, Y; Martin, B; McCarthy, R; McGivern, C L; Meijer, M M; Melnitchouk, A; Mendoza, L; Menezes, D; Mercadante, P G; Merkin, M; Meyer, A; Meyer, J; Mondal, N K; Montgomery, H E; Moore, R W; Moulik, T; Muanza, G S; Mulhearn, M; Mundal, O; Mundim, L; Nagy, E; Naimuddin, M; Narain, M; Neal, H A; Negret, J P; Neustroev, P; Nilsen, H; Nogima, H; Novaes, S F; Nunnemann, T; Obrant, G; Ochando, C; Onoprienko, D; Orduna, J; Oshima, N; Osman, N; Osta, J; Otec, R; Otero y Garzón, G J; Owen, M; Padilla, M; Padley, P; Pangilinan, M; Parashar, N; Park, S-J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Penning, B; Perfilov, M; Peters, K; Peters, Y; Pétroff, P; Piegaia, R; Piper, J; Pleier, M-A; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pol, M-E; Polozov, P; Popov, A V; Prewitt, M; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rakitine, A; Rangel, M S; Ranjan, K; Ratoff, P N; Renkel, P; Rich, P; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Robinson, S; Rominsky, M; Royon, C; Rubinov, P; Ruchti, R; Safronov, G; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Sanghi, B; Savage, G; Sawyer, L; Scanlon, T; Schaile, D; Schamberger, R D; Scheglov, Y; Schellman, H; Schliephake, T; Schlobohm, S; Schwanenberger, C; Schwienhorst, R; Sekaric, J; Severini, H; Shabalina, E; Shamim, M; Shary, V; Shchukin, A A; Shivpuri, R K; Siccardi, V; Simak, V; Sirotenko, V; Skubic, P; Slattery, P; Smirnov, D; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S

    2009-12-01

    We present a direct measurement of the width of the W boson using the shape of the transverse mass distribution of W --> enu candidate events. Data from approximately 1 fb(-1) of integrated luminosity recorded at square root of s = 1.96 TeV by the D0 detector at the Fermilab Tevatron pp collider are analyzed. We use the same methods and data sample that were used for our recently published W boson mass measurement, except for the modeling of the recoil, which is done with a new method based on a recoil library. Our result, 2.028 +/- 0.072 GeV, is in agreement with the predictions of the standard model. PMID:20366142

  7. Characterizing Width Uniformity by Wave Propagation

    CERN Document Server

    Costa, L F; Schubert, D; Costa, Luciano da F.; Mutinari, Giancarlo; Schubert, David

    2003-01-01

    This work describes a novel image analysis approach to characterize the uniformity of objects in agglomerates by using the propagation of normal wavefronts. The problem of width uniformity is discussed and its importance for the characterization of composite structures normally found in physics and biology highlighted. The methodology involves identifying each cluster (i.e. connected component) of interest, which can correspond to objects or voids, and estimating the respective medial axes by using a recently proposed wavefront propagation approach, which is briefly reviewed. The distance values along such axes are identified and their mean and standard deviation values obtained. As illustrated with respect to synthetic and real objects (in vitro cultures of neuronal cells), the combined use of these two features provide a powerful description of the uniformity of the separation between the objects, presenting potential for several applications in material sciences and biology.

  8. Characterizing width uniformity by wave propagation

    Science.gov (United States)

    Costa, Luciano Da; Mutinari, Giancarlo; Schubert, David

    2003-11-01

    This work describes a different image analysis approach to characterize the uniformity of objects in agglomerates by using the propagation of normal wave fronts. The problem of width uniformity is discussed and its importance for the characterization of composite structures normally found in physics and biology highlighted. The methodology involves identifying each cluster (i.e., connected component) of interest, which can correspond to objects or voids, and estimating the respective medial axes by using a recently proposed wave front propagation approach, which is briefly reviewed. The distance values along such axes are identified and their mean and standard deviation values obtained. As illustrated with respect to synthetic and real objects (in vitro cultures of neuronal cells), the combined use of these two features provides a powerful description of the uniformity of the separation between the objects, presenting potential for several applications in material sciences and biology.

  9. Width distribution for random-walk interfaces

    International Nuclear Information System (INIS)

    Roughening of a one-dimensional interface is studied under the assumption that the interface configurations are continuous, periodic random walks. The distribution of the square of the width of interface, w2, is found to scale as P(w2)=left-angle w2 right-angle -1?(w2/left-angle w2 right-angle) where left-angle w2 right-angle is the average of w2. We calculate the scaling function ?(x) exactly and compare it both to exact enumerations for a discrete-slope surface evolution model and to ?'s obtained in Monte Carlo simulations of equilibrium and driven interfaces of chemically reacting systems

  10. First Digit Distribution of Hadron Full Width

    CERN Document Server

    Shao, Lijing; 10.1142/S0217732309031223

    2010-01-01

    A phenomenological law, called Benford's law, states that the occurrence of the first digit, i.e., $1,2,...,9$, of numbers from many real world sources is not uniformly distributed, but instead favors smaller ones according to a logarithmic distribution. We investigate, for the first time, the first digit distribution of the full widths of mesons and baryons in the well defined science domain of particle physics systematically, and find that they agree excellently with the Benford distribution. We also discuss several general properties of Benford's law, i.e., the law is scale-invariant, base-invariant, and power-invariant. This means that the lifetimes of hadrons follow also Benford's law.

  11. First Digit Distribution of Hadron Full Width

    Science.gov (United States)

    Shao, Lijing; Ma, Bo-Qiang

    A phenomenological law, called Benford's law, states that the occurrence of the first digit, i.e. 1, 2,…, 9, of numbers from many real world sources is not uniformly distributed, but instead favors smaller ones according to a logarithmic distribution. We investigate, for the first time, the first digit distribution of the full widths of mesons and baryons in the well-defined science domain of particle physics systematically, and find that they agree excellently with the Benford distribution. We also discuss several general properties of Benford's law, i.e. the law is scale-invariant, base-invariant and power-invariant. This means that the lifetimes of hadrons also follow Benford's law.

  12. The ?N? coupling and the ?(1232) resonance width

    International Nuclear Information System (INIS)

    We calculate higher order mesonic effects contributing to the ?(1232) width and show that the quark model value for fsub(?N?) can be consistent with the experimental width. These contributions are very sensitive to the vertex form factors and to avoid drastic exaggeration of the ? width we need very long range cutoffs even for the p meson. (orig.)

  13. Global synchronization of parallel processors using clock pulse width modulation

    Science.gov (United States)

    Chen, Dong; Ellavsky, Matthew R.; Franke, Ross L.; Gara, Alan; Gooding, Thomas M.; Haring, Rudolf A.; Jeanson, Mark J.; Kopcsay, Gerard V.; Liebsch, Thomas A.; Littrell, Daniel; Ohmacht, Martin; Reed, Don D.; Schenck, Brandon E.; Swetz, Richard A.

    2013-04-02

    A circuit generates a global clock signal with a pulse width modification to synchronize processors in a parallel computing system. The circuit may include a hardware module and a clock splitter. The hardware module may generate a clock signal and performs a pulse width modification on the clock signal. The pulse width modification changes a pulse width within a clock period in the clock signal. The clock splitter may distribute the pulse width modified clock signal to a plurality of processors in the parallel computing system.

  14. Narrow-width mechanism of a=5 ?-state

    International Nuclear Information System (INIS)

    Narrow-width mechanism of ?5H is discussed by calculating conversion widths to all its possible decay channels. Since the conversion processes have small reaction Q values, the three- and four- body decays are strongly suppressed owing to small phase volumes available. Decay widths to the two-body channels are significantly reduced by the distortion of emitted-particle waves. This mechanism brings about a narrow width of ?5H. The total width is estimated to be 0.87 MeV, in which the largest contribution comes from the decay into the ?4H*+? channel. (author)

  15. Equivalences of Higher Derived Brackets

    OpenAIRE

    Cattaneo, A. S.; Scha?tz, F.

    2007-01-01

    This note elaborates on Th. Voronov’s construction [Th. Voronov, Higher derived brackets and homotopy algebras, J. Pure Appl. Algebra 202 (1–3) (2005) 133–153; Th. Voronov, Higher derived brackets for arbitrary derivations, Travaux Math. XVI (2005) 163–186] of L?-structures via higher derived brackets with a Maurer–Cartan element. It is shown that gauge equivalent Maurer–Cartan elements induce L?-isomorphic structures. Applications in symplectic, Poisson and Dirac geometry are...

  16. Speed analyses of stimulus equivalence.

    OpenAIRE

    Spencer, T. J.; Chase, P. N.

    1996-01-01

    The functional substitutability of stimuli in equivalence classes was examined through analyses of the speed of college students' accurate responding. After training subjects to respond to 18 conditional relations, subjects' accuracy and speed of accurate responding were compared across trial types (baseline, symmetry, transitivity, and combined transitivity and symmetry) and nodal distance (one- through five-node transitive and combined transitive and symmetric relations). Differences in acc...

  17. Equivalence of TBA and QTM

    CERN Document Server

    Takahashi, M; Klümper, A; Takahashi, Minoru; Shiroishi, Masahiro; Klumper, Andreas

    2001-01-01

    The traditional thermodynamic Bethe ansatz (TBA) equations for the XXZ model at $|\\Delta|\\ge 1$ are derived within the quantum transfer matrix (QTM) method. This provides further evidence of the equivalence of both methods. Most importantly, we derive an integral equation for the free energy formulated for just one unknown function. This integral equation is different in physical and mathematical aspects from the established ones. The single integral equation is analytically continued to the regime $|\\Delta|<1$.

  18. COMPLEX VARIABILITY OF THE H{alpha} EMISSION LINE PROFILE OF THE T TAURI BINARY SYSTEM KH 15D: THE INFLUENCE OF ORBITAL PHASE, OCCULTATION BY THE CIRCUMBINARY DISK, AND ACCRETION PHENOMENA

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, Catrina M. [Department of Physics and Astronomy, Dickinson College, Carlisle, PA 17013 (United States); Johns-Krull, Christopher M. [Department of Physics and Astronomy, Rice University, Houston, TX 77005 (United States); Mundt, Reinhard [Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany); Herbst, William [Astronomy Department, Wesleyan University, Middletown, CT 06459 (United States); Winn, Joshua N., E-mail: hamiltoc@dickinson.edu, E-mail: cmj@rice.edu, E-mail: mundt@mpia.de, E-mail: wherbst@wesleyan.edu, E-mail: jwinn@mit.edu [Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2012-06-01

    We have obtained 48 high-resolution echelle spectra of the pre-main-sequence eclipsing binary system KH 15D (V582 Mon, P = 48.37 days, e {approx} 0.6, M{sub A} = 0.6 M{sub Sun }, M{sub B} = 0.7 M{sub Sun }). The eclipses are caused by a circumbinary disk (CBD) seen nearly edge on, which at the epoch of these observations completely obscured the orbit of star B and a large portion of the orbit of star A. The spectra were obtained over five contiguous observing seasons from 2001/2002 to 2005/2006 while star A was fully visible, fully occulted, and during several ingress and egress events. The H{alpha} line profile shows dramatic changes in these time series data over timescales ranging from days to years. A fraction of the variations are due to 'edge effects' and depend only on the height of star A above or below the razor sharp edge of the occulting disk. Other observed variations depend on the orbital phase: the H{alpha} emission line profile changes from an inverse P-Cygni-type profile during ingress to an enhanced double-peaked profile, with both a blue and a red emission component, during egress. Each of these interpreted variations are complicated by the fact that there is also a chaotic, irregular component present in these profiles. We find that the complex data set can be largely understood in the context of accretion onto the stars from a CBD with gas flows as predicted by the models of eccentric T Tauri binaries put forward by Artymowicz and Lubow, Guenther and Kley, and de Val-Borro et al. In particular, our data provide strong support for the pulsed accretion phenomenon, in which enhanced accretion occurs during and after perihelion passage.

  19. GAP WIDTH STUDY IN LASER BUTT-WELDING

    DEFF Research Database (Denmark)

    Gong, Hui; Olsen, Flemming Ove

    1999-01-01

    In this paper the maximum allowable gap width in laser butt-welding is intensively studied. The gap width study (GWS) is performed on the material of SST of W1.4401 (AISI 316) under various welding conditions, which are the gap width : 0.00-0.50 mm, the welding speed : 0.5-2.0 m/min, the laser power : 2 and 2.6 kW and the focal point position : 0 and -1.2 mm. Quality of all the butt welds are destructively tested according to ISO 13919-1.Influences of the variable process parameters to the maximum allowable gap width are observed as (1) the maximum gap width is inversely related to the welding speed, (2) the larger laser power leads to the bigger maximum allowable gap width and (3) the focal point position has very little influence on the maximum gap width.

  20. Spatial width oscillations in meandering rivers at equilibrium

    Science.gov (United States)

    Luchi, R.; Bolla Pittaluga, M.; Seminara, G.

    2012-05-01

    In canaliform rivers channel width at bankfull stage is fairly uniform though, at bend apexes, it is typically smaller than at crossings. Conversely, in sinuous point bar rivers bankfull width peaks at bend apexes. Why? Is there any mechanistic constraint that forces this different behavior? We provide an answer to these questions investigating how bankfull width must vary in a sequence of sine-generated meanders in order for the constraints of equilibrium (constant flow discharge and sediment flux) to be satisfied. With the help of a 3-D fully nonlinear analytical model of flow and bed topography in meandering rivers with variable width, we show that, in a meandering channel characterized by a constant longitudinal free-surface slope, the equilibrium width thus obtained oscillates with a frequency twice the frequency of channel curvature and experiences the maximum width close to inflection points. This pattern is typically observed in canaliform rivers. We then show that a similar pattern is observed in sinuous point bar rivers, provided the hydrodynamic width (width of the free surface) is replaced by the active width, namely the width of the portion of the cross section where transport occurs at formative conditions. Theoretical results are substantiated by a satisfactory comparison with field observations referring to the Mississippi River (United States) and to the Bollin River (United Kingdom).

  1. Equivalence Principle in Chameleon Models

    CERN Document Server

    Kraiselburd, Lucila; Salgado, Marcelo; Sudarsky, Daniel

    2013-01-01

    Most theories that predict time and/or space variation of fundamental constants also predict violations of the Weak Equivalence Principle (WEP). Khoury and Weltmann proposed the chameleon model in 2004 and claimed that this model avoids experimental bounds on WEP. We present a contrasting view based on an approximate calculation of the two body problem for the chameleon field and show that the force depends on the test body composition. Furthermore, we compare the prediction of the force on a test body with E\\"otv\\"os type experiments and find that the chameleon field effect cannot account for current bounds.

  2. Pulse widths effects on scintillator saturation

    International Nuclear Information System (INIS)

    A test was performed over an extensive range of irrradiance (approximately five orders of magnitude) to see to what extent organic scintillators responded linearly with x-ray input. At the highest levels of irradiance achievable with the experimental configuration, but only for pulses in the region of 4.0 ns or wider, a degree of nonlinear response was observed for some of the scintillators. The data suggest that at levels below 1 mJ/cm2-ns it is safe to asume that for pulses 6.5 ns and shorter there is no significant level of nonlinearity to x rays with spectrum. For the cases of undoped NE111 and NE111 doped with 10 percent benzophenone, experimental conditions were such that it was possible to accumulate data significantly above the 1 mJ/cm2-ns level of irradiance. It is with these cases that a nonlinear response was observed. It is assumed that the same nonlinearity would have also been noticed had experimental conditions been such that equivalent levels of irradiance could have been achieved at the time the other samples were studied

  3. Laryngeal air column width ratio in predicting post extubation stridor

    Science.gov (United States)

    Venkategowda, Pradeep M.; Mahendrakar, Kranthi; Rao, S. Manimala; Mutkule, Dnyaneshwar P.; Shirodkar, Chetan G.; Yogesh, H.

    2015-01-01

    Aim: Correlation of upper air column width ratio in postextubation stridor patients. Materials and Methods: A prospective observational study was conducted in a tertiary hospital between January and December 2013. Patients who were admitted in Intensive Care Unit and intubated for >24 h were included (72 patients). The upper airway air column width ratio (air column width before extubation/air column width after intubation) was calculated and compared in patient with or without postextubation stridor. Results: The incidence of stridor was 6.9% (5/72). The duration of mechanical ventilation was 5.60 ± 1.14 days and 3.91 ± 1.45 days in stridor and nonstridor group respectively. In all 5 patients who had stridor, the upper airway air column width ratio was 0.8 or less. Conclusion: Air column width ratio of 0.8 or less may be helpful in predicting postextubation stridor, which should be confirmed by large observational studies.

  4. Characterization and modeling of a piezoelectric micromachined ultrasonic transducer with a very large length/width aspect ratio

    International Nuclear Information System (INIS)

    The objective of the current study was to characterize and model the performance of piezoelectric micromachined ultrasonic transducers (pMUTs) with large length/width aspect ratios. Single-element pMUTs with 20 different dimensions corresponding to aspect ratios ranging from 5:1 to 23:1 were designed. Multiple samples were fabricated for each design so that statistically meaningful data could be obtained. The pMUTs were characterized by the impedance measurement combined with an equivalent circuit analysis. A one-dimensional composite beam model was also used to correlate the equivalent circuit components with the structural parameters, and gain insight into the performance characteristics of pMUTs. The resonant frequencies were observed to decrease with the width of the membrane, but have no appreciable length dependence. With the correction of parasitic capacitance, the effective coupling coefficients were observed to increase with the width up to around 150 µm and then decrease. However, they did not show clear and consistent length dependence. The variation of the coupling coefficient as a function of width of the membrane was shown to be mainly due to the relative ratios between the electrode and membrane widths rather than membrane width itself. Although the model presented in this study was a simple one-dimensional electro-mechanical model, it did seem to offer both good qualitative and quantitative insights into the performance of pMUTs and provide a convenierformance of pMUTs and provide a convenient tool for designing thin membrane transducers with a large aspect ratio. The model can also take into consideration the residual stress effect and offer an even more realistic prediction

  5. The significance of biometric parameters in determining anterior teeth width

    Directory of Open Access Journals (Sweden)

    Strajni? Ljiljana

    2013-01-01

    Full Text Available Background/Aim. An important element of prosthetic treatment of edentulous patients is selecting the size of anterior artificial teeth that will restore the natural harmony of one’s dentolabial structure as well as the whole face. The main objective of this study was to determine the correlation between the inner canthal distance (ICD and interalar width (IAW on one side and the width of both central incisors (CIW, the width of central and lateral incisors (CLIW, the width of anterior teeth (ATW, the width between the canine cusps (CCW, which may be useful in clinical practice. Methods. A total of 89 subjects comprising 23 male and 66 female were studied. Their age ranged from 19 to 34 years with the mean of 25 years. Only the subjects with the preserved natural dentition were included in the sample. All facial and intraoral tooth measurements were made with a Boley Gauge (Buffalo Dental Manufacturing Co., Brooklyn NY, USA having a resolution of 0.1mm. Results. A moderate correlation was established between the interalar width and combined width of anterior teeth and canine cusp width (r = 0.439, r = 0.374. A low correlation was established between the inner canthal distance and the width of anterior teeth and canine cusp width (r = 0.335, r = 0.303. The differences between the two genders were highly significant for all the parameters (p < 0.01. The measured facial distances and width of anterior teeth were higher in men than in women. Conclusion. The results of this study suggest that the examined interalar width and inner canthal distance cannot be considered reliable guidelines in the selection of artificial upper anterior teeth. However, they may be used as a useful additional factor combined with other methods for objective tooth selection. The final decision should be made while working on dentures fitting models with the patient’s consent.

  6. Research on Fairway Width Design in Curved Bridge Waters Channel

    OpenAIRE

    Chi Hong-Fu; Wang Yuan-Jiao

    2013-01-01

    Bridge construction can promote economic development but if the bridge layout is unreasonable, it would hinder ship’s safety navigation in the bridge area. There is little reference for fairway width design about curved bridge channel in ??inland river navigation standards?? of China. In this study, a fairway width design method in curved bridge channel was put forward by taking into account the scope of turbulent scope of pier, ship’s track width, drifting distance due to wind, d...

  7. Light WIMPs And Equivalent Neutrinos

    CERN Document Server

    Steigman, Gary

    2014-01-01

    Very light WIMPs (chi), thermal relics that annihilate late in the early Universe, change the energy and entropy densities at BBN and at recombination. BBN, in combination with the CMB, can remove some of the degeneracies among light WIMPs and equivalent neutrinos, constraining the existence and properties of each. Depending on the nature of the light WIMP (Majorana or Dirac fermion, real or complex scalar) the joint BBN + CMB analyses set lower bounds to m_chi in the range 0.5 - 5 MeV (m_chi/m_e > 1 - 10), and they identify best fit values for m_chi in the range 5 - 10 MeV. The joint BBN + CMB analysis finds a best fit value for the number of equivalent neutrinos, Delta N_nu ~ 0.65, nearly independent of the nature of the WIMP. In the absence of a light WIMP (m_chi > 20 MeV), N_eff = 3.05(1 + Delta N_nu /3). In this case, there is excellent agreement between BBN and the CMB, but the joint fit reveals Delta N_nu = 0.40+-0.17, disfavoring standard big bang nucleosynthesis (SBBN) (Delta N_nu = 0) at ~ 2.4 sigma...

  8. A Theory of Network Equivalence

    CERN Document Server

    Koetter, Ralf; Medard, Muriel

    2010-01-01

    A family of equivalence tools for bounding network capacities is introduced. For networks of point-to-point channels, the main result is roughly as follows. Given a network of noisy, independent, memoryless point-to-point channels, a collection of demands can be met on the given network if and only if it can be met on another network where each noisy channel is replaced by a noiseless bit pipe with throughput equal to the noisy channel capacity. This result was known previously for the case of a single-source multicast demand. The result given here treats general demands -- including, for example, multiple unicast demands -- and applies even when the achievable rate region for the corresponding demands is unknown in both the noisy network and its noiseless counterpart. The equivalence tools are also used to bound the capacity of networks containing independent channels with multiple transmitters, multiple receivers, or both. In this case, upper and lower bounding models for broadcast, multiple access, and int...

  9. Sequential Decay Distortion of Goldhaber Model Widths for Spectator Fragments

    CERN Document Server

    Ma, Y G; Hagel, K; Murray, M; Ono, A; Wang, J S; Qin, L J; Makeev, A G; Smith, P; Natowitz, J B

    2002-01-01

    Momentum widths of the primary fragments and observed final fragments have been investigated within the framework of an Antisymmetrized Molecular Dynamics transport model code (AMD-V) with a sequential decay afterburner (GEMINI). It is found that the secondary evaporation effects cause the values of a reduced momentum width, $\\sigma_0$, derived from momentum widths of the final fragments to be significantly less than those appropriate to the primary fragment but close to those observed in many experiments. Therefore, a new interpretation for experiemental momentum widths of projectile-like fragments is presented.

  10. The Exact Bounds of Randomized Widths for Generalized Besov Classes

    Directory of Open Access Journals (Sweden)

    Duan Liqin

    2014-01-01

    Full Text Available We reformulate the widths problem in the framework of information-based complexity theory and study the Kolmogorov width and linear width for the generalized Besov classes in the randomized setting. Applying the discretization technique and some properties of pseudo-s-scale, we determine the exact asymptotic orders of these widths on these classes for certain values of the parameters p, q, ?. Our results show that the Monte Carlo methods lead to a better convergence rate than that of the deterministic ones for some parameters p, q. The maximal gain can reach a factor n-1/2 roughly.

  11. Asymptotic estimation of widths of the quasistationary states

    International Nuclear Information System (INIS)

    The new integral formalism for the calculation of the width of the quasistationary states without using smallness of the barrier penetration factor is proposed. Asymptotic formula for the width of the short-living quasistationary states on the base of saddle-point approximation is derived. On the base of our approach the widths of ?-decay of the Pb isotopes, baryon resonances and dibaryon resonances were calculated. A good agreement of the theory and experiment was demonstrated. The natural explanation of the small widths of low lying dibaryon resonances was argued. (author). 23 refs., 1 fig., 4 tabs

  12. 46 CFR 133.09 - Equivalents.

    Science.gov (United States)

    2010-10-01

    ...General § 133.09 Equivalents. When this part...particular fitting, material, or lifesaving appliance...any other fitting, material, or lifesaving...tests to determine the equivalent effectiveness of the substitute fitting, material, or lifesaving...

  13. 46 CFR 199.09 - Equivalents.

    Science.gov (United States)

    2010-10-01

    ...General § 199.09 Equivalents. When this part...particular fitting, material, or lifesaving appliance...any other fitting, material, or lifesaving...tests to determine the equivalent effectiveness of the substitute fitting, material, or lifesaving...

  14. 33 CFR 155.120 - Equivalents.

    Science.gov (United States)

    2010-07-01

    ...2010-07-01 2010-07-01 false Equivalents. 155.120 Section 155.120 Navigation and Navigable Waters COAST GUARD...POLLUTION PREVENTION REGULATIONS FOR VESSELS General § 155.120 Equivalents. (a) For ships...

  15. 7 CFR 1131.54 - Equivalent price.

    Science.gov (United States)

    2010-01-01

    ...2010-01-01 2009-01-01 true Equivalent price. 1131.54 Section 1131.54 Agriculture Regulations of the Department...AREA Order Regulating Handling Class Prices § 1131.54 Equivalent price. See § 1000.54....

  16. A Discrete Equivalent of the Logistic Equation

    OpenAIRE

    Petropoulou EugeniaN

    2010-01-01

    A discrete equivalent and not analogue of the well-known logistic differential equation is proposed. This discrete equivalent logistic equation is of the Volterra convolution type, is obtained by use of a functional-analytic method, and is explicitly solved using the -transform method. The connection of the solution of the discrete equivalent logistic equation with the solution of the logistic differential equation is discussed. Also, some differences of the discrete equivalent logistic equa...

  17. An equivalent sample circuit based on DSP

    International Nuclear Information System (INIS)

    The author introduced an equivalent sample circuit which is based on DSP. With the technology of equivalent sample this circuit can sample signal with maximum 10 GHz equivalent sample rate under the condition of 40 MHz single-shot sample rate. The author describes the design theory and its advantage

  18. Equivalent networks for SAW gratings.

    Science.gov (United States)

    Koshiba, M; Mitobe, S

    1988-01-01

    An equivalent-network approach is described for the analysis of surface-acoustic-wave gratings. Circuit parameters can be theoretically determined by applying the finite-element method to an infinite array. In this approach, all of the effects of piezoelectric perturbation, mechanical perturbation, and energy storage are taken into account. To show the validity and usefulness of this approach, examples are computed for groove and metallic gratings. Both short and open circuited metallic gratings are treated. For grooves on isotropic and Y-Z LiNbO(3) substrates, the dependence of reflection characteristics on groove depth is investigated. For aluminum strips on X-112 degrees Y LiTaO(3) 34 degrees Y-X quartz, Y-Z LiNbO(3), and 128 degrees Y -X LiNbO(3) substrates, the dependence on metallization ratio is investigated in detail. PMID:18290184

  19. Einstein's equivalence principle in cosmology

    CERN Document Server

    Kopeikin, Sergei M

    2013-01-01

    We study physical consequences of the Einstein equivalence principle (EEP) for a Hubble observer in FLRW universe. We introduce the local inertial coordinates with the help of a special conformal transformation. The local inertial metric is Minkowski flat and materialized by a congruence of time-like geodesics of static observers. The static observers are equipped with the ideal clocks measuring the proper time that is synchronized with the clocks of the Hubble observer. The local inertial metric is used for physical measurements of spacetime intervals with the ideal clocks and rulers. The special conformal transformation preserves null geodesics but does not keep invariant time-like geodesics. Moreover, it makes the rate of the local time coordinate dependent on velocity of the particle which makes impossible to rich the uniform parameterization of the world lines of static observers and light geodesics with a single parameter - they differ by the conformal factor of FLRW metric. The most convenient way to s...

  20. Sparsity Equivalence of Anisotropic Decompositions

    CERN Document Server

    Kutyniok, Gitta

    2011-01-01

    Anisotropic decompositions using representation systems such as curvelets, contourlet, or shearlets have recently attracted significantly increased attention due to the fact that they were shown to provide optimally sparse approximations of functions exhibiting singularities on lower dimensional embedded manifolds. The literature now contains various direct proofs of this fact and of related sparse approximation results. However, it seems quite cumbersome to prove such a canon of results for each system separately, while many of the systems exhibit certain similarities. In this paper, with the introduction of the concept of sparsity equivalence, we aim to provide a framework which allows categorization of the ability for sparse approximations of representation systems. This framework, in particular, enables transferring results on sparse approximations from one system to another. We demonstrate this concept for the example of curvelets and shearlets, and discuss how this viewpoint immediately leads to novel r...

  1. Measurement of the mass, full width, and radiative width of the B+ (1237) meson

    International Nuclear Information System (INIS)

    An experiment was performed at Fermi National Accelerator Laboratory to investigate the coherent production of mesons on nuclear targets (lead and copper). The experiment used 200 GeV/c incident meson beam and a high resolution forward spectrometer consisting of proportional and drift chambers plus a liquid argon photon calorimeter. This thesis reports the results of the process ?+ + A ? ?+ omega + A. The ?+ omega spectrum was found to be dominated by the B+ (1237) meson. A fit was performed on the line shape of the ?+ omega mass spectrum and values of 1.271 +/- 0.011 GeV and 0.232 +/- 0.029 GeV were found for the mass and total width. The helicity zero decay probability of the omega, absolute value F02, was measured to be absolute value F02 = 0.15 +/- 0.035. The t distributions were analyzed allowing the electromagnetic and hadronic production processes to interfer. From these distributions a radiative width of 230 +/- 61 was extracted

  2. Measuring Slit Width and Separation in a Diffraction Experiment

    Science.gov (United States)

    Gan, K. K.; Law, A. T.

    2009-01-01

    We present a procedure for measuring slit width and separation in single- and double-slit diffraction experiments. Intensity spectra of diffracted laser light are measured with an optical sensor (PIN diode). Slit widths and separations are extracted by fitting to the measured spectra. We present a simple fitting procedure to account for the…

  3. Spreading width of nuclear excitations at finite temperature

    International Nuclear Information System (INIS)

    In this paper the damping of single-particle states and giant vibrations in heavy nuclei are calculated as a function of the nuclear excitation energy. The single-particle width increases almost linearly with temperature. The width of giant vibrations remains essentially constant in the interval O?T?3 MeV

  4. ?-clustering and absolute ?-decay width in Po isotopes

    International Nuclear Information System (INIS)

    The absolute alpha-decay widths in Po isotopes are calculated using a shell-model description of the alpha-particle formation. It is found that high-lying shell-model configurations greatly enchance both the alpha-clustering features and the calculated absolute alpha-decay widths. (author)

  5. On the band width of resonant gravitational-wave antennas

    International Nuclear Information System (INIS)

    The band width of a resonant gravitational-wave antenna depends on the ratio GAMMA of the wide-band noise to the narrow-band noise. For GAMMA ? 0 the band width becomes infinitely large, even if the coupling parameter between bar and transducer is small

  6. Research on Fairway Width Design in Curved Bridge Waters Channel

    Directory of Open Access Journals (Sweden)

    Chi Hong-Fu

    2013-01-01

    Full Text Available Bridge construction can promote economic development but if the bridge layout is unreasonable, it would hinder ship’s safety navigation in the bridge area. There is little reference for fairway width design about curved bridge channel in ??inland river navigation standards?? of China. In this study, a fairway width design method in curved bridge channel was put forward by taking into account the scope of turbulent scope of pier, ship’s track width, drifting distance due to wind, drifting distance due to current, the scope of ship’s safety field and additional width in curved channel. The fairway width design concept for curved bridge channel presented in this studyit may provide reference for bridge design and other fairway layout.

  7. Neutron-induced background by an alpha-beam incident on a deuterium gas target and its implications for the study of the 2H(alpha,gamma)6Li reaction at LUNA

    CERN Document Server

    Anders, M; Bellini, A; Aliotta, M; Bemmerer, D; Broggini, C; Caciolli, A; Costantini, H; Corvisiero, P; Davinson, T; Elekes, Z; Erhard, M; Formicola, A; Fülöp, Zs; Gervino, G; Guglielmetti, A; Gustavino, C; Gyürky, Gy; Junker, M; Lemut, A; Marta, M; Mazzocchi, C; Menegazzo, R; Prati, P; Alvarez, C Rossi; Scott, D; Somorjai, E; Straniero, O; Szücs, T

    2013-01-01

    The production of the stable isotope Li-6 in standard Big Bang nucleosynthesis has recently attracted much interest. Recent observations in metal-poor stars suggest that a cosmological Li-6 plateau may exist. If true, this plateau would come in addition to the well-known Spite plateau of Li-7 abundances and would point to a predominantly primordial origin of Li-6, contrary to the results of standard Big Bang nucleosynthesis calculations. Therefore, the nuclear physics underlying Big Bang Li-6 production must be revisited. The main production channel for Li-6 in the Big Bang is the 2H(alpha,gamma)6Li reaction. The present work reports on neutron-induced effects in a high-purity germanium detector that were encountered in a new study of this reaction. In the experiment, an {\\alpha}-beam from the underground accelerator LUNA in Gran Sasso, Italy, and a windowless deuterium gas target are used. A low neutron flux is induced by energetic deuterons from elastic scattering and, subsequently, the 2H(d,n)3He reaction....

  8. GLACE survey: OSIRIS/GTC Tuneable Filter H$\\alpha$ imaging of the rich galaxy cluster ZwCl 0024.0+1652 at z = 0.395. Part I -- Survey presentation, TF data reduction techniques and catalogue

    CERN Document Server

    Sánchez-Portal, Miguel; Pérez-Martínez, Ricardo; Cepa, Jordi; García, Ana M Pérez; Domínguez-Sánchez, Helena; Bongiovanni, Ángel; Serra, Ana L; Alfaro, Emilio; Altieri, Bruno; Aragón-Salamanca, Alfonso; Balkowski, Chantal; Biviano, Andrea; Bremer, Malcom; Castander, Francisco; Castañeda, Héctor; Castro-Rodríguez, Nieves; Chies-Santos, Ana L; Coia, Daniela; Diaferio, Antonaldo; Duc, Pierre-Alain; Ederoclite, Alessandro; Geach, James; González-Serrano, Ignacio; Haines, Chris P; McBreen, Brian; Metcalfe, Leo; Oteo, Iván; Pérez-Fournón, Ismael; Poggianti, Bianca; Polednikova, Jana; Ramón-Pérez, Marina; Rodríguez-Espinosa, José M; Santos, Joana S; Smail, Ian; Smith, Graham P; Temporin, Sonia; Valtchanov, Ivan

    2015-01-01

    The cores of clusters at 0 $\\lesssim$ z $\\lesssim$ 1 are dominated by quiescent early-type galaxies, whereas the field is dominated by star-forming late-type ones. Galaxy properties, notably the star formation (SF) ability, are altered as they fall into overdense regions. The critical issues to understand this evolution are how the truncation of SF is connected to the morphological transformation and the responsible physical mechanism. The GaLAxy Cluster Evolution Survey (GLACE) is conducting a study on the variation of galaxy properties (SF, AGN, morphology) as a function of environment in a representative sample of clusters. A deep survey of emission line galaxies (ELG) is being performed, mapping a set of optical lines ([OII], [OIII], H$\\beta$ and H$\\alpha$/[NII]) in several clusters at z $\\sim$ 0.40, 0.63 and 0.86. Using the Tunable Filters (TF) of OSIRIS/GTC, GLACE applies the technique of TF tomography: for each line, a set of images at different wavelengths are taken through the TF, to cover a rest fra...

  9. A large, multi-epoch H{\\alpha} survey at z=2.23, 1.47, 0.84 & 0.40: the 11 Gyr evolution of star-forming galaxies from HiZELS

    CERN Document Server

    Sobral, David; Best, Philip N; Geach, James E; Matsuda, Yuichi; Stott, John P; Cirasuolo, Michele; Kurk, Jaron

    2012-01-01

    This paper presents new deep and wide narrow-band surveys undertaken with UKIRT, Subaru and the VLT; a unique combined effort to select large, robust samples of H-alpha (Ha) emitters at z=0.40, 0.84, 1.47 and 2.23 (corresponding to look-back times of 4.2, 7.0, 9.2 and 10.6 Gyrs) in a uniform manner over ~2 deg^2 in the COSMOS and UDS fields. The deep multi-epoch Ha surveys reach ~3M_sun/yr out to z=2.2 for the first time, while the wide area and the coverage over two independent fields allow to greatly overcome cosmic variance. A total of 1742, 637, 515 and 556 Ha emitters are homogeneously selected at z=0.40, 0.84, 1.47 and 2.23, respectively, and used to determine the Ha luminosity function and its evolution. The faint-end slope is found to be -1.60+-0.08 over z=0-2.23, showing no evolution. The characteristic luminosity of SF galaxies, L*, evolves significantly as log[L*(z)]=0.45z+log[L*(z=0)]. This is the first time Ha has been used to trace SF activity with a single homogeneous survey at z=0.4-2.23. Over...

  10. DO QUASAR BROAD-LINE VELOCITY WIDTHS ADD ANY INFORMATION TO VIRIAL BLACK HOLE MASS ESTIMATES?

    International Nuclear Information System (INIS)

    We examine how much information measured broad-line widths add to virial black hole (BH) mass estimates for flux-limited samples of quasars. We do this by comparing the BH mass estimates to those derived by randomly reassigning the quasar broad-line widths to different objects and re-calculating the BH mass. For 9000 BH masses derived from the H? line we find that the distributions of original and randomized BH masses in the MBH-redshift plane and the MBH-luminosity plane are formally identical. A two-dimensional Kolmogorov-Smirnov test does not find a difference at >90% confidence. For the Mg II line (32,000 quasars) we do find very significant differences between the randomized and original BH masses, but the amplitude of the difference is still small. The difference for the C IV line (14,000 quasars) is 2?-3? and again the amplitude of the difference is small. Subdividing the data into redshift and luminosity bins we find that the median absolute difference in BH mass between the original and randomized data is 0.025, 0.01, and 0.04 dex for H?, Mg II, and C IV, respectively. The maximum absolute difference is always ?0.1 dex. We investigate whether our results are sensitive to corrections to Mg II virial masses, such as those suggested by Onken and Kollmeier. These corrections do not influence our results, other than to reduce the significance of the difference between original and randomized BH masses to only 1?-2? for Mg II. Moreover to only 1?-2? for Mg II. Moreover, we demonstrate that the correlation between mass residuals and Eddington ratio discussed by Onken and Kollmeier is more directly attributable to the slope of the relation between H? and Mg II line width. The implication is that the measured quasar broad-line velocity widths provide little extra information, after allowing for the mean velocity width. In this case virial estimates are equivalent to MBH?L?, with L/LEdd?L1-? (with ? ? 0.5). This leaves an unanswered question of why the accretion efficiency changes with luminosity in just the right way to keep the mean broad-line widths fixed as a function of luminosity.

  11. Violation of the gauge equivalence

    CERN Document Server

    Khrapko, R I

    2001-01-01

    F. V. Gubarev et al. (``On the significance of the vector potential squared'', Phys. Rev. Lett. 86, 2220) have argued that the minimum value of the volume integral of the vector potential squared may have physical meaning, in defiance of the gauge equivalence of potentials. Earlier, R. I. Khrapko proposed a gauge noninvariant electrodynamics spin tensor (``Spin density of electromagnetic waves'', [1]). The standard electrodynamics spin tensor is zero. Here we point out that the Biot-Savarat formula uniquely results in a preferred, "true" vector potential field which is generated from a given magnetic field. A similar integral formula uniquely permits to find a "true" scalar potential field generated from a given electric field even in the case of a nonpotential electric field. We say that an exterior derivative of a differential form is the boundary of this form and the integration of a form results in a new form named the generation. Generating from a generation yields zero. A boundary is closed. A generatio...

  12. Low-temperature measurement of the giant dipole resonance width

    Energy Technology Data Exchange (ETDEWEB)

    Heckman, P.; Bazin, D.; Beene, J.R.; Blumenfeld, Y.; Chromik, M.J.; Halbert, M.L.; Liang, J.F.; Mohrmann, E.; Nakamura, T.; Navin, A.; Sherrill, B.M.; Snover, K.A.; Thoennessen, M.; Tryggestad, E.; Varner, R.L

    2003-02-27

    The width of the giant dipole resonance (GDR) built on excited states was determined from a measurement of {gamma}-decays in coincidence with {sup 17}O particles scattered inelastically from {sup 120}Sn. The bombarding energy was 80 MeV/u. A width of 4{+-}1 MeV, consistent with the width of the GDR built on the ground state, was found at a temperature T=1 MeV. This result is in disagreement with adiabatic thermal shape fluctuation calculations, indicating an overestimation of the influence of thermal shape fluctuations at low temperature.

  13. Influence of electrical sheet width on dynamic magnetic properties

    CERN Document Server

    Chevalier, T; Cornut, B

    2000-01-01

    Effects of the width of electrical steel sheets on dynamic magnetic properties are investigated by solving diffusion equation on the cross-section of the sheet. Linear and non-linear cases are studied, and are compared with measurement on Epstein frame. For the first one an analytical solution is found, while for the second, a 2D finite element simulation is achieved. The influence of width is highlighted for a width thickness ratio lower than 10. It is shown that the behaviour modification in such cases is conditioned by the excitation signal waveform, amplitude and also frequency.

  14. Nightside studies of coherent HF Radar spectral width behaviour

    Directory of Open Access Journals (Sweden)

    E. E. Woodfield

    Full Text Available A previous case study found a relationship between high spectral width measured by the CUTLASS Finland HF radar and elevated electron temperatures observed by the EISCAT and ESR incoherent scatter radars in the post-midnight sector of magnetic local time. This paper expands that work by briefly re-examining that interval and looking in depth at two further case studies. In all three cases a region of high HF spectral width (>200 ms-1 exists poleward of a region of low HF spectral width (<200 ms-1. Each case, however, occurs under quite different geomagnetic conditions. The original case study occurred during an interval with no observed electrojet activity, the second study during a transition from quiet to active conditions with a clear band of ion frictional heating indicating the location of the flow reversal boundary, and the third during an isolated sub-storm. These case studies indicate that the relationship between elevated electron temperature and high HF radar spectral width appears on closed field lines after 03:00 magnetic local time (MLT on the nightside. It is not clear whether the same relationship would hold on open field lines, since our analysis of this relationship is restricted in latitude. We find two important properties of high spectral width data on the nightside. Firstly the high spectral width values occur on both open and closed field lines, and secondly that the power spectra which exhibit high widths are both single-peak and multiple-peak. In general the regions of high spectral width (>200 ms-1 have more multiple-peak spectra than the regions of low spectral widths whilst still maintaining a majority of single-peak spectra. We also find that the region of ion frictional heating is collocated with many multiple-peak HF spectra. Several mechanisms for the generation of high spectral width have been proposed which would produce multiple-peak spectra, these are discussed in relation to the data presented here. Since the regions of high spectral width are observed both on closed and open field lines the use of the boundary between low and high spectral width as an ionospheric proxy for the open/closed field line boundary is not a simple matter, if indeed it is possible at all.

    Key words. Ionosphere (auroral ionosphere; ionospheric irregularities

  15. Qualitative Logics and Equivalences for Probabilistic Systems

    CERN Document Server

    Chatterjee, Krishnendu; Faella, Marco; Legay, Axel

    2009-01-01

    We investigate logics and equivalence relations that capture the qualitative behavior of Markov Decision Processes (MDPs). We present Qualitative Randomized CTL (QRCTL): formulas of this logic can express the fact that certain temporal properties hold over all paths, or with probability 0 or 1, but they do not distinguish among intermediate probability values. We present a symbolic, polynomial time model-checking algorithm for QRCTL on MDPs. The logic QRCTL induces an equivalence relation over states of an MDP that we call qualitative equivalence: informally, two states are qualitatively equivalent if the sets of formulas that hold with probability 0 or 1 at the two states are the same. We show that for finite alternating MDPs, where nondeterministic and probabilistic choices occur in different states, qualitative equivalence coincides with alternating bisimulation, and can thus be computed via efficient partition-refinement algorithms. On the other hand, in non-alternating MDPs the equivalence relations cann...

  16. Once again on the equivalence theorem

    International Nuclear Information System (INIS)

    The equivalence theorem in quantum field theory is proven on the basis of the field-antifield formalism. It is shown that the equivalence theorem does not contradict the well-known fact that, in quantum theory, some symmetries of the classical action functional are broken (anomalous). By way of example, a model is considered where natural finite counterterms can be chosen in different ways leading to physically nonequivalent quantum theories, but where the equivalence theorem remains valid

  17. Equivalent Simplification Method of Micro-Grid

    OpenAIRE

    Cai Changchun; Cao Xiangqin

    2013-01-01

    The paper concentrates on the equivalent simplification method for the micro-grid system connection into distributed network. The equivalent simplification method proposed for interaction study between micro-grid and distributed network. Micro-grid network, composite load, gas turbine synchronous generation, wind generation are equivalent simplification and parallel connect into the point of common coupling. A micro-grid system is built and three phase and single phase grounded faults are per...

  18. The relation between incurvated nail plate width and the transverse width of distal phalanx. A CT scan study

    International Nuclear Information System (INIS)

    To clarify the cause of incurvated nail, the relation between the nail plate and the distal phalanx of the patient of incurvated/ingrown nail and normal subjects was compared, by measuring CT scan images. The investigation was made on 12 incurvated nails, 8 ingrown nails and 8 normal nails of the first toes which were clinically diagnosed as such. Each toe was scanned at 1 mm intervals with the same CT scanner under the same conditions. The pictures taken on the film were scanned and input into a computer. The transverse width of the distal phalanx and the width of the nail plate were measured on each slice. The minimum transverse width of the distal phalanx in both stages of slightly and intensively incurvated nail was smaller as compared to that in the stages of normal nail and ingrown nail. The ratios of the width of the nail plate to the minimum transverse width of the distal phalanx in the stages of normal nail, ingrown nail and intensively incurvated nail were nearly equal, while the ratio in the stage of slightly incurvated nail was outstandingly large. Based on the results of this investigation, it can be considered that the transverse width of the distal phalanx is reduced first, and consequently, the incurvation of the nail plate occurs, then the width of the nail plate is reduced as the incurvation becomes more intense. (author)

  19. Behavioural equivalence for infinite systems - Partially decidable!

    DEFF Research Database (Denmark)

    Sunesen, Kim; Nielsen, Mogens

    1996-01-01

    For finite-state systems non-interleaving equivalences are computationally at least as hard as interleaving equivalences. In this paper we show that when moving to infinite-state systems, this situation may change dramatically. We compare standard language equivalence for process description languages with two generalizations based on traditional approaches capturing non-interleaving behaviour, pomsets representing global causal dependency, and locality representing spatial distribution of events. We first study equivalences on Basic Parallel Processes, BPP, a process calculus equivalent to communication free Petri nets. For this simple process language our two notions of non-interleaving equivalences agree. More interestingly, we show that they are decidable, contrasting a result of Hirshfeld that standard interleaving language equivalence is undecidable. Our result is inspired by a recent result of Esparza and Kiehn, showing the same phenomenon in the setting of model checking. We follow up investigating towhich extent the result extends to larger subsets of CCS and TCSP. We discover a significant difference between our non-interleaving equivalences. We show that for a certain non-trivial subclass of processes between BPP and TCSP, not only are the two equivalences different, but one (locality) is decidable whereas the other (pomsets) is not. The decidability result for locality is proved by a reduction to the reachability problem for Petri nets.

  20. Viscous finger width dependence on channel aspect ratio

    Science.gov (United States)

    Moore, Mitchell G.; Juel, Anne; Burgess, John M.; Swift, J. B.; McCormick, W. D.; Swinney, Harry L.

    2000-11-01

    Viscous finger patterns develop when a less viscous fluid is driven into a more viscous fluid in a Hele-Shaw channel. An initially flat interface develops into the finger pattern; at low flow rates, a single finger forms. Past studies of single fingers indicate that the asymptotic finger width varies with the driving parameter according to a -2/3 power law. However, we find a significant deviation from this relation for wide channels (where the ratio of channel width to gap thickness is greater than approximately 250). At low velocities, the finger growth is unsteady, and mean finger widths become phnarrower. As the finger velocity is increased, tip instabilities occur before finger growth becomes steady. The theoretically described steady state is thus not observed. In the low finger velocity regime, power law scaling of the standard deviation of the finger widths is observed.

  1. Improved determination of the width of the top quark

    Science.gov (United States)

    Abazov, V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Alverson, G.; Aoki, M.; Askew, A.; Åsman, B.; Atkins, S.; Atramentov, O.; Augsten, K.; Avila, C.; BackusMayes, J.; Badaud, F.; Bagby, L.; Baldin, B.; Bandurin, D. V.; Banerjee, S.; Barberis, E.; Baringer, P.; Barreto, J.; Bartlett, J. F.; Bassler, U.; Bazterra, V.; Bean, A.; Begalli, M.; Belanger-Champagne, C.; Bellantoni, L.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Bertram, I.; Besançon, M.; Beuselinck, R.; Bezzubov, V. A.; Bhat, P. C.; Bhatia, S.; Bhatnagar, V.; Blazey, G.; Blessing, S.; Bloom, K.; Boehnlein, A.; Boline, D.; Boos, E. E.; Borissov, G.; Bose, T.; Brandt, A.; Brandt, O.; Brock, R.; Brooijmans, G.; Bross, A.; Brown, D.; Brown, J.; Bu, X. B.; Buehler, M.; Buescher, V.; Bunichev, V.; Burdin, S.; Burnett, T. H.; Buszello, C. P.; Calpas, B.; Camacho-Pérez, E.; Carrasco-Lizarraga, M. A.; Casey, B. C. K.; Castilla-Valdez, H.; Chakrabarti, S.; Chakraborty, D.; Chan, K. M.; Chandra, A.; Chapon, E.; Chen, G.; Chevalier-Théry, S.; Cho, D. K.; Cho, S. W.; Choi, S.; Choudhary, B.; Cihangir, S.; Claes, D.; Clutter, J.; Cooke, M.; Cooper, W. E.; Corcoran, M.; Couderc, F.; Cousinou, M.-C.; Croc, A.; Cutts, D.; Das, A.; Davies, G.; de Jong, S. J.; De La Cruz-Burelo, E.; Déliot, F.; Demina, R.; Denisov, D.; Denisov, S. P.; Desai, S.; Deterre, C.; DeVaughan, K.; Diehl, H. T.; Diesburg, M.; Ding, P. F.; Dominguez, A.; Dorland, T.; Dubey, A.; Dudko, L. V.; Duggan, D.; Duperrin, A.; Dutt, S.; Dyshkant, A.; Eads, M.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Enari, Y.; Evans, H.; Evdokimov, A.; Evdokimov, V. N.; Facini, G.; Ferbel, T.; Fiedler, F.; Filthaut, F.; Fisher, W.; Fisk, H. E.; Fortner, M.; Fox, H.; Fuess, S.; Garcia-Bellido, A.; García-Guerra, G. A.; Gavrilov, V.; Gay, P.; Geng, W.; Gerbaudo, D.; Gerber, C. E.; Gershtein, Y.; Ginther, G.; Golovanov, G.; Goussiou, A.; Graf, C. P.; Grannis, P. D.; Greder, S.; Greenlee, H.; Greenwood, Z. D.; Gregores, E. M.; Grenier, G.; Gris, Ph.; Grivaz, J.-F.; Grohsjean, A.; Grünendahl, S.; Grünewald, M. W.; Guillemin, T.; Gutierrez, G.; Gutierrez, P.; Haas, A.; Hagopian, S.; Haley, J.; Han, L.; Harder, K.; Harel, A.; Hauptman, J. M.; Hays, J.; Head, T.; Hebbeker, T.; Hedin, D.; Hegab, H.; Heinson, A. P.; Heintz, U.; Hensel, C.; Heredia-De La Cruz, I.; Herner, K.; Hesketh, G.; Hildreth, M. D.; Hirosky, R.; Hoang, T.; Hobbs, J. D.; Hoeneisen, B.; Hohlfeld, M.; Hubacek, Z.; Hynek, V.; Iashvili, I.; Ilchenko, Y.; Illingworth, R.; Ito, A. S.; Jabeen, S.; Jaffré, M.; Jamin, D.; Jayasinghe, A.; Jesik, R.; Johns, K.; Johnson, M.; Jonckheere, A.; Jonsson, P.; Joshi, J.; Jung, A. W.; Juste, A.; Kaadze, K.; Kajfasz, E.; Karmanov, D.; Kasper, P. A.; Katsanos, I.; Kehoe, R.; Kermiche, S.; Khalatyan, N.; Khanov, A.; Kharchilava, A.; Kharzheev, Y. N.; Kohli, J. M.; Kozelov, A. V.; Kraus, J.; Kulikov, S.; Kumar, A.; Kupco, A.; Kur?a, T.; Kuzmin, V. A.; Lammers, S.; Landsberg, G.; Lebrun, P.; Lee, H. S.; Lee, S. W.; Lee, W. M.; Lellouch, J.; Li, H.; Li, L.; Li, Q. Z.; Lietti, S. M.; Lim, J. K.; Lincoln, D.; Linnemann, J.; Lipaev, V. V.; Lipton, R.; Liu, Y.; Lobodenko, A.; Lokajicek, M.; Lopes de Sa, R.; Lubatti, H. J.; Luna-Garcia, R.; Lyon, A. L.; Maciel, A. K. A.; Mackin, D.; Madar, R.; Magaña-Villalba, R.; Malik, S.; Malyshev, V. L.; Maravin, Y.; Martínez-Ortega, J.; McCarthy, R.; McGivern, C. L.; Meijer, M. M.; Melnitchouk, A.; Menezes, D.; Mercadante, P. G.; Merkin, M.; Meyer, A.; Meyer, J.; Miconi, F.; Mondal, N. K.; Muanza, G. S.; Mulhearn, M.; Nagy, E.; Naimuddin, M.; Narain, M.; Nayyar, R.; Neal, H. A.; Negret, J. P.; Neustroev, P.; Novaes, S. F.; Nunnemann, T.; Obrant, G.; Orduna, J.; Osman, N.; Osta, J.; Otero y Garzón, G. J.; Padilla, M.; Pal, A.; Parashar, N.; Parihar, V.; Park, S. K.; Partridge, R.; Parua, N.; Patwa, A.; Penning, B.; Perfilov, M.; Peters, Y.; Petridis, K.; Petrillo, G.; Pétroff, P.; Piegaia, R.; Pleier, M.-A.; Podesta-Lerma, P. L. M.; Podstavkov, V. M.; Polozov, P.; Popov, A. V.; Prewitt, M.; Price, D.; Prokopenko, N.; Qian, J.; Quadt, A.; Quinn, B.; Rangel, M. S.; Ranjan, K.; Ratoff, P. N.; Razumov, I.; Renkel, P.; Rijssenbeek, M.; Ripp-Baudot, I.; Rizatdinova, F.; Rominsky, M.; Ross, A.; Royon, C.; Rubinov, P.; Ruchti, R.; Safronov, G.; Sajot, G.; Salcido, P.; Sánchez-Hernández, A.; Sanders, M. P.; Sanghi, B.; Santos, A. S.; Savage, G.; Sawyer, L.; Scanlon, T.; Schamberger, R. D.; Scheglov, Y.; Schellman, H.; Schliephake, T.; Schlobohm, S.; Schwanenberger, C.; Schwienhorst, R.; Sekaric, J.; Severini, H.; Shabalina, E.; Shary, V.; Shchukin, A. A.; Shivpuri, R. K.; Simak, V.; Sirotenko, V.; Skubic, P.; Slattery, P.; Smirnov, D.; Smith, K. J.; Snow, G. R.; Snow, J.; Snyder, S.; Söldner-Rembold, S.; Sonnenschein, L.

    2012-05-01

    We present an improved determination of the total width of the top quark, ?t, using 5.4fb-1 of integrated luminosity collected by the D0 Collaboration at the Tevatron pp¯ Collider. The total width ?t is extracted from the partial decay width ?(t?Wb) and the branching fraction B(t?Wb). ?(t?Wb) is obtained from the t-channel single top-quark production cross section and B(t?Wb) is measured in tt¯ events. For a top mass of 172.5 GeV, the resulting width is ?t=2.00-0.43+0.47GeV. This translates to a top-quark lifetime of ?t=(3.29-0.63+0.90)×10-25s. We also extract an improved direct limit on the Cabibbo-Kobayashi-Maskawa quark-mixing matrix element 0.81matrix.

  2. Optical waveguide device with an adiabatically-varying width

    Science.gov (United States)

    Watts; Michael R. (Albuquerque, NM), Nielson; Gregory N. (Albuquerque, NM)

    2011-05-10

    Optical waveguide devices are disclosed which utilize an optical waveguide having a waveguide bend therein with a width that varies adiabatically between a minimum value and a maximum value of the width. One or more connecting members can be attached to the waveguide bend near the maximum value of the width thereof to support the waveguide bend or to supply electrical power to an impurity-doped region located within the waveguide bend near the maximum value of the width. The impurity-doped region can form an electrical heater or a semiconductor junction which can be activated with a voltage to provide a variable optical path length in the optical waveguide. The optical waveguide devices can be used to form a tunable interferometer (e.g. a Mach-Zehnder interferometer) which can be used for optical modulation or switching. The optical waveguide devices can also be used to form an optical delay line.

  3. Statistical uncertainty in line shift and width interpretation

    OpenAIRE

    Hutchinson, I. H.

    2012-01-01

    Elementary but general statistical analyses determine the uncertainty arising from photon statistics in measuring a line shift and width. Account is taken of a background as well as the required signal.

  4. On the Stark Width Regularities Along the Argon Isonuclear Sequence

    Science.gov (United States)

    Djenize, S.; Sreckovic, A.

    Recent values of the measured spectral lines Stark widths (since 1988) for neutral and ionized argon atoms, have been compared to the values previously predicted by us. These were found from the established regularities of the Stark widths along the argon isonuclear sequence for 4s-4p and 4s'-4p' types of transitions. Using new experimental Stark width values we have established trends for 4p-4d, 4p'-4d' and 4p-5s type of transitions which enables predictions of the Stark width values for the Ar III and Ar VIII spectral lines, that have not been calculated or measured before, but are of a considerable astrophysical interest.

  5. The effect of buffer zone width on biodiversity

    DEFF Research Database (Denmark)

    Navntoft, SØren; Sigsgaard, Lene

    2012-01-01

    Field margin management for conservation purposes is a way to protect both functional biodiversity and biodiversity per se without considerable economical loss as field margins are less productive. However, the effect of width of the buffer zone on achievable biodiversity gains has received little attention in previous studies. In this paper we report on finding for syrphids, spiders and carabids, three taxonomic groups with different mobility, all important for conservation biological control. For all groups we found an effect of buffer zone width on their density. A buffer width of 6m was the narrowest that consistently promoted a higher abundance or activity of arthropods within the field area (outside the hedge bottom). However, a further increase in buffer width always increased the abundance and activity of arthropods a little more.

  6. Determination of the radiative decay width of the ?c meson

    International Nuclear Information System (INIS)

    An analysis of the reaction ????c was performed in five different decay channels of the ?c: KS0K±?F, K+K-?+?-, 2?+2?-, ?? and 2K+2K-. A value ???(?c)=(11.3±4.2) keV was obtained for the radiative decay width by combining the results from the first four channels. Using our result on the two-photon width we also determined the branching ratio for the decay ?c?2K+2K-. (orig.)

  7. SM Higgs decay branching ratios and total Higgs width

    CERN Multimedia

    Daniel Denegri

    2001-01-01

    Upper: Higgs decay ratios as a function of Higgs mass. The largest branching ratio is not necessarily the most usefull one. The most usefull ones are gamma gamma bbar ZZ and WW as in those modes latter signal to background ratios can be achieved. Lower: Total Higgs decay width versus Higgs mass. At low masses the natural width is extremely small, thus observability depends on instrumental resolution primarily.

  8. Correlations for reduced-width amplitudes in 49V

    International Nuclear Information System (INIS)

    Measurement of the relative sign of inelastic proton-channel amplitudes permits the determination of amplitude correlations. Data were obtained for 45 5/2+ resonances in 49V. Although the reduced widths in each channel followed a Porter-Thomas distribution, large amplitude correlations were observed. The results are compared with the reduced-width--amplitude distribution of Krieger and Porter. This is the first direct test of the Krieger-Porter distribution

  9. Domain Wall Width in Different Ferroelectrics via Perturbation Route

    OpenAIRE

    Ray, Pratap C.; Bandyopadhyay, Asis K.; Kamal Choudhary; Arnab Sengupta; Anik Bandyopadhyay

    2012-01-01

    The domains are of fundamental interest for engineering a ferroelectric material. The domain wall and its width control the ferroelectric behavior to a great extent. The stability of polarization in the context of Landau-Ginzburg free energy functional has been worked out in a previous work by a perturbation approach, where two limits of domain wall width were estimated within the stability zone and they were also found to correspond well with the data on lithium niobate and lithium tantalate...

  10. A direct measurement of W boson decay width

    CERN Document Server

    Abazov, V M; Abdesselam, A; Abolins, M; Abramov, V; Acharya, B S; Adams, D L; Adams, M; Ahmed, S N; Alexeev, G D; Alton, A; Alves, G A; Anderson, E W; Arnoud, Y; Avila, C; Baarmand, M M; Babintsev, V V; Babukhadia, L; Bacon, Trevor C; Baden, A; Baldin, B Yu; Balm, P W; Banerjee, S; Barberis, E; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Bean, A; Beaudette, F; Begel, M; Belyaev, A; Beri, S B; Bernardi, G; Bertram, I; Besson, A; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Bhattacharjee, M; Blazey, G; Blekman, F; Blessing, S; Böhnlein, A; Bozhko, N; Bolton, T A; Borcherding, F; Bos, K; Bose, T; Brandt, A; Breedon, R; Briskin, G; Brock, R; Brooijmans, G; Bross, A; Buchholz, D; Bühler, M; Büscher, V; Burtovoi, V S; Butler, J M; Canelli, F; Carvalho, W; Casey, D; Casilum, Z; Castilla-Valdez, H; Chakraborty, D; Chan, K M; Chekulaev, S V; Cho, D K; Choi, S; Chopra, S; Christenson, J H; Chung, M; Claes, D; Clark, A R; Coney, L; Connolly, B; Cooper, W E; Coppage, D; Crepe-Renaudin, S; Cummings, M A C; Cutts, D; Davis, G A; De, K; De Jong, S J; Demarteau, M; Demina, R; Demine, P; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Doulas, S; Ducros, Y; Dudko, L V; Duensing, S; Duflot, L; Dugad, S R; Duperrin, A; Dyshkant, A; Edmunds, D; Ellison, J; Eltzroth, J T; Elvira, V D; Engelmann, R; Eno, S; Eppley, G; Ermolov, P; Eroshin, O V; Estrada, J; Evans, H; Evdokimov, V N; Fahland, T; Fein, D; Ferbel, T; Filthaut, Frank; Fisk, H E; Fisyak, Yu; Flattum, E; Fleuret, F; Fortner, M; Fox, H; Frame, K C; Fu, S; Fuess, S; Gallas, E; Galjaev, A N; Gao, M; Gavrilov, V; Genik, R J; Genser, K; Gerber, C E; Gershtein, Yu; Gilmartin, R; Ginther, G; Gómez, B; Goncharov, P I; Gordon, H; Goss, L T; Gounder, K; Goussiou, A; Graf, N; Grannis, P D; Green, J A; Greenlee, H; Greenwood, Z D; Grinstein, S; Groer, L; Grünendahl, S; Sen-Gupta, A; Gurzhev, S N; Gutíerrez, G; Gutíerrez, P; Hadley, N J; Haggerty, H; Hagopian, S; Hagopian, V; Hall, R E; Hansen, S; Hauptman, J M; Hays, C; Hebert, C; Hedin, D; Heinmiller, J M; Heinson, A P; Heintz, U; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Huang, Y; Iashvili, I; Illingworth, R; Ito, A S; Jaffré, M; Jain, S; Jesik, R; Johns, K; Johnson, M; Jonckheere, A; Jöstlein, H; Juste, A; Kahl, W; Kahn, S; Kajfasz, E; Kalinin, A M; Karmanov, D; Karmgard, D; Kehoe, R; Khanov, A; Kharchilava, A I; Kim, S K; Klima, B; Knuteson, B; Ko, W; Kohli, J M; Kostritskii, A V; Kotcher, J; Kothari, B; Kotwal, A V; Kozelov, A V; Kozlovskii, E A; Krane, J; Krishnaswamy, M R; Krivkova, P; Krzywdzinski, S; Kubantsev, M A; Kuleshov, S; Kulik, Y; Kunori, S; Kupco, A; Kuznetsov, V E; Landsberg, G L; Lee, W M; Leflat, A; Leggett, C; Lehner, F; Leonidopoulos, C; Li, J; Li, Q Z; Lima, J G R; Lincoln, D; Linn, S L; Linnemann, J; Lipton, R; Lucotte, A; Lueking, L; Lundstedt, C; Luo, C; Maciel, A K A; Madaras, R J; Malyshev, V L; Manankov, V; Mao, H S; Marshall, T; Martin, M I; Mayorov, A A; McCarthy, R; McMahon, T; Melanson, H L; Merkin, M; Merritt, K W; Miao, C; Miettinen, H; Mihalcea, D; Mishra, C S; Mokhov, N V; Mondal, N K; Montgomery, H E; Moore, R W; Mostafa, M; Da Motta, H; Mutaf, Y; Nagy, E; Nang, F; Narain, M; Narasimham, V S; Naumann, N A; Neal, H A; Negret, J P; Nomerotski, A; Nunnemann, T; O'Neil, D; Oguri, V; Olivier, B; Oshima, N; Padley, P; Pan, L J; Papageorgiou, K; Parashar, N; Partridge, R; Parua, N; Paterno, M; Patwa, A; Pawlik, B; Peters, O; Petroff, P; Piegaia, R; Pope, B G; Popkov, E; Prosper, H B; Protopopescu, S D; Przybycien, M B; Qian, J; Raja, R; Rajagopalan, S; Ramberg, E; Rapidis, P A; Reay, N W; Reucroft, S; Ridel, M; Rijssenbeek, M; Rizatdinova, F K; Rockwell, T; Roco, M T; Royon, C; Rubinov, P; Ruchti, R; Rutherfoord, J; Sabirov, B M; Sajot, G; Santoro, A F S; Sawyer, L; Schamberger, R D; Schellman, H; Schwartzman, A; Sen, N; Shabalina, E; Shivpuri, R K; Shpakov, D; Shupe, M; Sidwell, R A; Simák, V; Singh, H; Sirotenko, V I; Slattery, P F; Smith, E; Smith, R P; Snihur, R; Snow, G R; Snow, J; Snyder, S; Solomon, J; Song, Y; Sorin, V; Sosebee, M; Sotnikova, N; Soustruznik, K; Souza, M; Stanton, N R; Steinbruck, G; Stephens, R W; Stoker, D; Stolin, V; Stone, A; Stoyanova, D A; Strang, M A; Strauss, M; Strovink, M; Stutte, L; Sznajder, A; Talby, M; Taylor, W; Tentindo-Repond, S; Tripathi, S M; Trippe, T G; Turcot, A S; Tuts, P M; Vaniev, V; Van Kooten, R; Varelas, N; Vertogradov, L S; Villeneuve-Séguier, F; Volkov, A A; Vorobev, A P; Wahl, H D; Wang, H; Wang, Z M; Warchol, J; Watts, G; Wayne, M; Weerts, H; White, A; White, J T; Whiteson, D; Wijngaarden, D A; Willis, S; Wimpenny, S J; Womersley, J; Wood, D R; Xu, Q; Yamada, R; Yamin, P; Yasuda, T; Yatsunenko, Y A; Yip, K; Youssef, S; Yu, J; Zanabria, M; Zhang, X; Zheng, H; Zhou, B; Zhou, Z; Zielinski, M; Zieminska, D; Zieminski, A; Zutshi, V; Zverev, E G; Zylberstejn, A

    2002-01-01

    Based on 85 pb$^{-1}$ data of \\ppbar collisions at $\\sqrt{s}=1.8$ \\tev\\ collected using the D{\\O}detector at Fermilab during the 1994-1995 run of the Tevatron, we present a direct measurement of the total decay width of the \\wb\\ boson, $\\Gamma_W$. The width is determined from the transverse mass spectrum in the $W \\to e+\

  11. Echo width of foam supports used in scattering measurements

    DEFF Research Database (Denmark)

    Appel-Hansen, JØrgen; Solodukhov, V. V.

    1979-01-01

    Theoretically and experimentally determined echo widths of dielectric cylinders having circular, triangular, and quadratic cross sections have been compared. The cylinders were made of foam material having a relative dielectric constant of about 1.035. The purpose of the investigation was to find a cross section with a small echo width. The result can be used in selecting a proper support for test objects in backscattering measurement studies.

  12. Bone Mineral Density Value Dependence on Bone Width

    Directory of Open Access Journals (Sweden)

    M. Mokhtari-Dizaji

    2006-05-01

    Full Text Available Dual x-ray absorptiometry (DXA is the most widely used measurement for the assessment of bone mass in osteoporosis. In clinical measurement, bone width can affect bone mineral parameters. The purpose of this study was to examine the dependence of bone mineral pa-rameters on bone width. In this study, DXA measurements were conducted on rabbit bone in vivo using clinical instruments. We have selected rabbit’s bones that have low BMD and more collagen tissue to predict structure not only measures BMD, but is also sensitive to the structure of the bone. To investigate the effect of bone width on the measured parameters, three regions of femur and tibia bones (N=132 were processed: upper (1/3 of length, middle (1/2 of length and lower (2/3 of length for BMC, areal BMD and volumetric BMD. The ANOVA analysis of bone mineral extracted by DXA showed significant differences (P<0.05 between BMC, BMDa and BMDv of six groups of upper, middle and lower parts of the femur and the tibia. It shows that BMC and BMD correlate well with the bone width, but BMDv inversely correlates with bone width. Linear and nonlinear regression analyses were used to examine the relationship between DXA characteristics with bone width and the regression function for each parameter is given. We concluded that BMC, areal BMD, and volumetric BMD in rabbit's bone with collagen fibers more than bone mineral are dependent on bone width. This result may be at least in part due to large precision error measurement of the bone width, in vivo.

  13. Modeling morphodynamic processes in meandering rivers with spatial width variations

    Science.gov (United States)

    Zolezzi, G.; Luchi, R.; Tubino, M.

    2012-12-01

    Most morphodynamic models of river meandering assume spatially constant width; depending on the intensity of spatial width variations, different meandering styles actually exist, often associated with midchannel bars and islands. When intense enough, width oscillations characterize transitional planforms between meandering and braiding. We investigate, on a modeling basis, morphodynamic feedbacks between spatial curvature and width oscillations in river meanders and related bedform patterns. Our review of existing mathematical models suggests that width-curvature interactions can be comprehensively analyzed by a hierarchy of models that descend from a two-parameter perturbation solution of the governing depth-averaged morphodynamic model. The focus is on in-stream, autogenic hydromorphodynamic processes, and not explicitly on bank processes. Curvature-width interactions are fundamentally nonlinear: the perturbation approach allows us to investigate the key effects at the first nonlinear interaction. In meanders with initially constant width, curvature nonlinearly forces midchannel bar growth, promoting symmetrical bank erosion further downstream, possibly triggering width oscillations. These in turn can significantly affect the process of bend stability and therefore condition the curvature dynamics. Wider-at-bends meanders develop shorter bends and are morphologically more active compared to equiwidth meanders, coherently with the few available field observations. River evolution models aiming to separately simulate bank erosion and accretion processes should incorporate these autogenic flow-bed nonlinearities. Because of its focus on meandering morphologies close to the transition with braiding, the proposed approach can be taken as a novel, physically based viewpoint to the long-debated subject of channel pattern selection.

  14. Simulation studies on strip width dimension for ICAL

    International Nuclear Information System (INIS)

    The aim of this study is to see the influence of strip width on the physics studies for ICAL through its effect on momentum resolution, angle resolution, reconstruction efficiency, charge identification efficiency and shift in the mean of reconstructed energy of the muon and neutrinos. This will also have implications for the quantum of electronics required for the detector. The study has been carried out for single muons and pions considering different strip width dimensions and 5.6 cm iron plate thickness using GEANT4 and the complete ICAL detector geometry. In principle decreasing the strip width should result in an improvement in the resolution for a fixed iron plate thickness. But due to the straggling in moderately thick absorbers the improvement is very small for strip widths between 1.6 cm and 4 cm. However the angle resolution improves marginally for the lower strip width. Hence for an iron plate thickness of 5.6 cm decreasing the strip width does not cause a significant improvement in momentum response

  15. Crack width monitoring of concrete structures based on smart film

    Science.gov (United States)

    Zhang, Benniu; Wang, Shuliang; Li, Xingxing; Zhang, Xu; Yang, Guang; Qiu, Minfeng

    2014-04-01

    Due to its direct link to structural security, crack width is thought to be one of the most important parameters reflecting damage conditions of concrete structures. However, the width problem is difficult to solve with the existing structural health monitoring methods. In this paper, crack width monitoring by means of adhering enameled copper wires with different ultimate strains on the surface of structures is proposed, based on smart film crack monitoring put forward by the present authors. The basic idea of the proposed method is related to a proportional relationship between the crack width and ultimate strain of the broken wire. Namely, when a certain width of crack passes through the wire, some low ultimate strain wires will be broken and higher ultimate strain wires may stay non-broken until the crack extends to a larger scale. Detection of the copper wire condition as broken or non-broken may indicate the width of the structural crack. Thereafter, a multi-layered stress transfer model and specimen experiment are performed to quantify the relationship. A practical smart film is then redesigned with this idea and applied to Chongqing Jiangjin Yangtze River Bridge.

  16. Neutron-induced background by an {alpha}-beam incident on a deuterium gas target and its implications for the study of the {sup 2}H({alpha},{gamma}){sup 6}Li reaction at LUNA

    Energy Technology Data Exchange (ETDEWEB)

    Anders, M.; Bemmerer, D.; Elekes, Z.; Marta, M. [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden (Germany); Trezzi, D.; Mazzocchi, C. [INFN, Sezione di Milano, Milano (Italy); Bellini, A.; Costantini, H.; Corvisiero, P.; Lemut, A.; Prati, P. [Universita di Genova (Italy); INFN, Sezione di Genova, Dipartimento di Fisica, Genova (Italy); Aliotta, M.; Davinson, T.; Scott, D. [University of Edinburgh, SUPA, School of Physics and Astronomy, Edinburgh (United Kingdom); Broggini, C.; Caciolli, A.; Erhard, M.; Menegazzo, R.; Rossi Alvarez, C. [INFN, Sezione di Padova, Padova (Italy); Formicola, A.; Junker, M. [Laboratori Nazionali del Gran Sasso, INFN, Assergi (Italy); Fueloep, Zs.; Gyuerky, G.; Somorjai, E.; Szuecs, T. [Institute of Nuclear Research (ATOMKI), Debrecen (Hungary); Gervino, G. [Universita di Torino (Italy); INFN, Dipartimento di Fisica Sperimentale, Torino (Italy); Guglielmetti, A. [INFN, Sezione di Milano, Milano (Italy); Universita degli Studi di Milano, Milano (Italy); Gustavino, C. [INFN, Sezione di Roma ' ' La Sapienza' ' , Roma (Italy); Straniero, O. [INFN, Sezione di Napoli, Napoli (Italy); Osservatorio Astronomico di Collurania, Teramo (Italy); Collaboration: LUNA Collaboration

    2013-02-15

    The production of the stable isotope {sup 6}Li in standard Big Bang nucleosynthesis has recently attracted much interest. Recent observations in metal-poor stars suggest that a cosmological {sup 6}Li plateau may exist. If true, this plateau would come in addition to the well-known Spite plateau of {sup 7}Li abundances and would point to a predominantly primordial origin of {sup 6}Li, contrary to the results of standard Big Bang nucleosynthesis calculations. Therefore, the nuclear physics underlying Big Bang {sup 6}Li production must be revisited. The main production channel for {sup 6}Li in the Big Bang is the {sup 2}H({alpha},{gamma}){sup 6}Li reaction. The present work reports on neutron-induced effects in a high-purity germanium detector that were encountered in a new study of this reaction. In the experiment, an {alpha}-beam from the underground accelerator LUNA in Gran Sasso, Italy, and a windowless deuterium gas target are used. A low neutron flux is induced by energetic deuterons from elastic scattering and, subsequently, the {sup 2}H(d,n){sup 3}He reaction. Due to the ultra-low laboratory neutron background at LUNA, the effect of this weak flux of 2-3 MeV neutrons on well-shielded high-purity germanium detectors has been studied in detail. Data have been taken at 280 and 400keV {alpha}-beam energy and for comparison also using an americium-beryllium neutron source. (orig.)

  17. On uncertainties in definition of dose equivalent

    International Nuclear Information System (INIS)

    The author has entertained always the doubt that in a neutron field, if the measured value of the absorbed dose with a tissue equivalent ionization chamber is 1.02±0.01 mGy, may the dose equivalent be taken as 10.2±0.1 mSv. Should it be 10.2 or 11, but the author considers it is 10 or 20. Even if effort is exerted for the precision measurement of absorbed dose, if the coefficient being multiplied to it is not precise, it is meaningless. [Absorbed dose] x [Radiation quality fctor] = [Dose equivalent] seems peculiar. How accurately can dose equivalent be evaluated ? The descriptions related to uncertainties in the publications of ICRU and ICRP are introduced, which are related to radiation quality factor, the accuracy of measuring dose equivalent and so on. Dose equivalent shows the criterion for the degree of risk, or it is considered only as a controlling quantity. The description in the ICRU report 1973 related to dose equivalent and its unit is cited. It was concluded that dose equivalent can be considered only as the absorbed dose being multiplied by a dimensionless factor. The author presented the questions. (K.I.)

  18. Bisimulations meet PCTL equivalences for probabilistic automata

    OpenAIRE

    Song, Lei; Zhang, Lijun; Godskesen, Jens Chr; Nielson, Flemming

    2013-01-01

    Probabilistic automata (PAs) have been successfully applied in formal verification of concurrent and stochastic systems. Efficient model checking algorithms have been studied, where the most often used logics for expressing properties are based on probabilistic computation tree logic (PCTL) and its extension PCTL^*. Various behavioral equivalences are proposed, as a powerful tool for abstraction and compositional minimization for PAs. Unfortunately, the equivalences are well...

  19. A Measurement of the Total Width, the Electronic Width and the Mass of the Upsilon(10580) Resonance

    CERN Document Server

    Aubert, Bernard; Abe, T; Abrams, G S; Adye, T; Ahmed, S; Alam, M S; Albert, J; Aleksan, Roy; Allison, J; Altenburg, D; Andreotti, M; Angelini, C; Anulli, F; Aston, D; Azzolini, V; Baak, M A; Back, J J; Bailey, S; Baldini-Ferroli, R; Band, H R; Banerjee, Sw; Barate, R; Barlow, N R; Barlow, R J; Bartoldus, R; Batignani, G; Bauer, J M; Beck, T W; Behera, P K; Bellini, F; Benayoun, M; Berger, N; Beringer, J; Bernard, D; Berryhill, J W; Best, D; Bettarini, S; Bettoni, D; Bevan, A J; Bhimji, W; Bianchi, F; Biasini, M; Blanc, F; Blaylock, G; Blinov, V E; Bloom, P; Bondioli, M; Bonneaud, G R; Borean, C; Borgland, A W; Bosisio, L; Boutigny, D; Bowerman, D A; Boyarski, A M; Boyd, J T; Bozzi, C; Brandt, T; Brau, B; Brau, J E; Breon, A B; Briand, H; Brigljevic, V; Brochard, F; Brose, J; Brown, C L; Brown, C M; Brown, D; Brown, D N; Bruinsma, M; Brunet, S; Bucci, F; Buchanan, C; Buchmüller, O L; Bugg, W; Bukin, A D; Burchat, Patricia R; Button-Shafer, J; Buzzo, A; Bóna, M; Cahn, R N; Calabrese, R; Calcaterra, A; Calderini, G; Campagnari, C; Capra, R; Carpinelli, M; Cartaro, C; Cavallo, N; Cavoto, G; Chao, M; Charles, E; Chauveau, J; Chen, E; Chen, J C; Chen, S; Cheng, C H; Chevalier, N; Christ, S; Cibinetto, G; Clark, P J; Cochran, J; Cohen-Tanugi, J; Colberg, T; Colecchia, F; Coleman, J P; Contri, R; Convery, M R; Cote-Ahern, D; Cottingham, W N; Coupal, D P; Cowan, G; Cowan, R; Crawley, H B; Cremaldi, L M; Crosetti, G; Dahmes, B; Dallapiccola, C; Danielson, N; Dasu, S; Datta, M; Dauncey, P D; David, P; Davier, M; Davis, C L; Day, C T; De Groot, N; De Nardo, Gallieno; De Sangro, R; Del Buono, L; Del Gamba, V; Del Re, D; Della Ricca, G; Di Lodovico, F; Dickopp, M; Dittongo, S; Donald, M; Dong, D; Dorfan, J; Dorigo, A; Dubitzky, R S; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W M; Dvoretskii, A; Eckmann, R; Edwards, A J; Egede, U; Eichenbaum, A M; Eigen, G; Eisner, A M; Elmer, P; Emery, S; Ernst, J A; Eschenburg, V; Eschrich, I; Fabozzi, F; Faccini, R; Falciai, D; Farbin, A; Ferrarotto, F; Ferroni, F; Field, R C; Finocchiaro, G; Fisher, A; Flack, R L; Flächer, H U; Flood, K T; Ford, K; Ford, W T; Forti, A C; Forti, F; Fortin, D; Franek, B J; Frey, R; Fry, J R; Gabathuler, Erwin; Gabriel, T A; Gaidot, A; Gaillard, J M; Gaillard, J R; Galeazzi, F; Gallo, F; Gamba, D; Gamet, R; Gan, K K; Ganzhur, S F; Gaspero, M; Gatto, C; Geddes, N I; George, S; Gill, M S; Giorgi, M A; Giraud, P F; Gladney, L; Glanzman, T; Godang, R; Goetzen, K; Golubev, V B; Gopal, G P; Gowdy, S J; Grancagnolo, S; Graugès-Pous, E; Green, M G; Grenier, G J; Grenier, P; Gritsan, A V; Grosdidier, G; Groysman, Y; Guo, Q H; Hadavand, H K; Hadig, T; Haire, M; Halyo, V; Hamel de Monchenault, G; Hamon, O; Harrison, P F; Harrison, T J; Hart, P A; Hartfiel, B L; Harton, J L; Hast, C; Hauke, A; Hawkes, C M; Hearty, C; Held, T; Hertzbach, S S; Heusch, C A; Hicheur, A; Hill, E J; Hitlin, D G; Hodgkinson, M C; Honscheid, K; Hrynóva, T; Hu, T; Hufnagel, D; Höcker, A; Innes, W R; Ivanchenko, V N; Izen, J M; Jackson, F; Jackson, P D; Jacobsen, R G; Jawahery, A; Jayatilleke, S M; Jessop, C P; John, M J J; Johnson, J R; Judd, D; Kadel, R W; Kadyk, J; Kagan, H; Karyotakis, Yu; Kass, R; Kay, M; Kelly, M P; Kelsey, M H; Kerth, L T; Khan, A; Kim, H; Kim, P; Kirkby, D; Kitayama, I; Knowles, D J; Koch, H; Kocian, M L; Kofler, R; Kolomensky, Yu G; Koptchev, V B; Kovalskyi, D; Kowalewski, R V; Kozanecki, Witold; Kral, J F; Kravchenko, E A; Krishnamurthy, M; Kroeger, R; Kukartsev, G; Kurup, A; Kutter, P E; Kuznetsova, N; Kyberd, P; La Vaissière, C de; Lacker, H M; Lae, C K; Lafferty, G D; Lamsa, J; Lanceri, L; Lange, D J; Langenegger, U; Langer, M; Lankford, A J; Laplace, S; Latham, T E; Lavin, D; Lazzaro, A; Le Clerc, C; Le Diberder, F R; Lee, S J; Lees, J P; Legendre, M; Leith, D W G S; Lepeltier, V; Leruste, P; Levesque, J A; Levi, M E; Levy, S L; Lewandowski, B; Li, H; Lillard, V; Lista, L; Liu, R; Lo Vetere, M; LoSecco, J M; Lockman, W S; London, G W; Long, O; Lou, X C; Lu, A; Luitz, S; Luppi, E; Lusiani, A; Lutz, A M; Lynch, G; Lynch, H L; Lyon, A J; Lü, C; Lüth, V; MacFarlane, D B; MacKay, C; Macri, M; Mallik, U; Maly, E; Mancinelli, G; Mandelkern, M A; Manfredi, P F; Mangeol, D J J; Marchiori, G; Margoni, M; Marker, C E; Marsiske, H; Martínez-Vidal, F; Mattison, T S; Mayer, B; Mazur, M A; Mazzoni, M A; McKemey, A K; McKenna, J A; McMahon, T R; Meadows, B T; Messner, R; Meyer, T I; Meyer, W T; Miftakov, V; Mihályi, A; Mir, L M; Mohapatra, A K; Mommsen, R K; Monge, M R; Moore, T B; Morandin, M; Morgan, S E; Morganti, M; Morganti, S; Morii, M; Morton, G W; Muheim, F; Müller, D R; Müller-Pfefferkorn, R; Narsky, I; Nash, J A; Nauenberg, U; Neal, H; Negrini, M; Neri, N; Nicholson, H; Nogowski, R; O'Grady, C P; Ocariz, J; Oddone, P J; Ofte, I; Olaiya, E O; Olivas, A; Olsen, J; Onuchin, A P; Orimoto, T J; Otto, S; Ozcan, V E; Paar, H P

    2003-01-01

    We present a preliminary measurement of the resonance parameters of the Upsilon(10580) resonance with the BABAR detector at the SLAC PEP-II asymmetric B factory. We measure the total decay width to be (20.7 +- 1.6 +- 2.5) MeV, the partial electronic width to be (0.321 +- 0.017 +- 0.029) kev and the mass to be (10.5793 +- 0.0004 +- 0.0012) GeV.

  20. Renault's Equivalence Theorem for Reduced Groupoid C*-algebras

    OpenAIRE

    Sims, Aidan; Williams, Dana P.

    2010-01-01

    We use the technology of linking groupoids to show that equivalent groupoids have Morita equivalent reduced C*-algebras. This equivalence is compatible in a natural way in with the Equivalence Theorem for full groupoid C*-algebras.

  1. Equivalency relations in magnetic space groups

    International Nuclear Information System (INIS)

    The set of all possible magnetic space groups, belonging to the same crystallographic space group is generally redundant, many magnetic groups being equivalent by a change of axes and/or a shift of origin. The equivalency relations are established for each admissible k-vector in space groups with primitive and non primitive lattices. In turn a family of non equivalent magnetic space groups is entirely specified by giving for each crystallographic space group the admissible k-vectors and the coresponding equivalency relations. Their tabulation given here is equivalent to the complete enumeration of the 1421 magnetic space groups and, although more informative, does not take more space than the classical enumerations of Belov et al. and Opechowski et al

  2. Equivalence in Ventilation and Indoor Air Quality

    Energy Technology Data Exchange (ETDEWEB)

    Sherman, Max; Walker, Iain; Logue, Jennifer

    2011-08-01

    We ventilate buildings to provide acceptable indoor air quality (IAQ). Ventilation standards (such as American Society of Heating, Refrigerating, and Air-Conditioning Enginners [ASHRAE] Standard 62) specify minimum ventilation rates without taking into account the impact of those rates on IAQ. Innovative ventilation management is often a desirable element of reducing energy consumption or improving IAQ or comfort. Variable ventilation is one innovative strategy. To use variable ventilation in a way that meets standards, it is necessary to have a method for determining equivalence in terms of either ventilation or indoor air quality. This study develops methods to calculate either equivalent ventilation or equivalent IAQ. We demonstrate that equivalent ventilation can be used as the basis for dynamic ventilation control, reducing peak load and infiltration of outdoor contaminants. We also show that equivalent IAQ could allow some contaminants to exceed current standards if other contaminants are more stringently controlled.

  3. Bisimulations meet PCTL equivalences for probabilistic automata

    DEFF Research Database (Denmark)

    Song, Lei; Zhang, Lijun

    2013-01-01

    Probabilistic automata (PAs) have been successfully applied in formal verification of concurrent and stochastic systems. Efficient model checking algorithms have been studied, where the most often used logics for expressing properties are based on probabilistic computation tree logic (PCTL) and its extension PCTL*. Various behavioral equivalences are proposed, as a powerful tool for abstraction and compositional minimization for PAs. Unfortunately, the equivalences are well-known to be sound, but not complete with respect to the logical equivalences induced by PCTL or PCTL*. The desire of a both sound and complete behavioral equivalence has been pointed out by Segala in [34], but remains open throughout the years. In this paper we introduce novel notions of strong bisimulation relations, which characterize PCTL and PCTL* exactly. We extend weak bisimulations that characterize PCTL and PCTL* without next operator, respectively. Further, we also extend the framework to simulation preorders. Thus, our paper bridges the gap between logical and behavioral equivalences and preorders in this setting.

  4. ??????–???????Kolmogorov??????????????? The Beam-Width Spread and Directionality of Partially Coherent Hermite-Ganssian Beams Propagating through Non-Kolmogorov Atmospheric Turbulence*

    Directory of Open Access Journals (Sweden)

    ???

    2013-05-01

    Full Text Available ???????–???????Kolmogorov????????????–??(H-G?????Kolmogorov????????????????????????????H-G??????????????????????????????????????????????????????0???????m?n???????H-G???????????????????????0????????????z??????????????????0???????H-G?????????????????????H-G???????Kolmogorov???????????????????????????????H-G?????????H-G???????–????(GSM????????????????Kolmogorov?????????????????????????????????? Based on the extended Huygens-Fresnel principle and non-Kolmogorov spectrum, analytical expressions for the beam-width spread of partially coherent Hermite-Ganssian (H-G beams propagating through non-Kolmogorov atmospheric turbulence are derived, and used to study the beam-width spreading and directionality of partially coherent H-G beams propagating through non-Kolmogorov atmospheric turbulence. The relative width is introduced to quantitatively describe the resistance of a beam to atmospheric turbulence. It is shown that the smaller the spatial correlation length ?0, and the larger the beam order m, n, and the less the beam-width spreading of partially coherent H-G beams is affected by non-Kolmogorov atmospheric turbulence. The influence of turbulence on beam-width spreading depends on the waist width ?0 and propagation distance z, when the propagation distance is sufficiently long, the smaller the waist width ?0, the less the beam-width spreading of partially coherent H-G beams is affected by non-Kolmogorov atmospheric turbulence. The beam width of partially coherent H-G beams through non-Kolmogorov atmospheric turbulence increase with the increasing exponent parameter ?, then decrease with increasing ?. There exist equivalent partially coherent and fully coherent H-G beams, GSM beams, which have the same directionality as a fully coherent Gaussian laser beam in free space and in non-Kolmogorov atmospheric turbulence. The results are interpreted physically.  

  5. Capacitor charging FET switcher with controller to adjust pulse width

    Science.gov (United States)

    Mihalka, Alex M. (Livermore, CA)

    1986-01-01

    A switching power supply includes an FET full bridge, a controller to drive the FETs, a programmable controller to dynamically control final output current by adjusting pulse width, and a variety of protective systems, including an overcurrent latch for current control. Power MOSFETS are switched at a variable frequency from 20-50 kHz to charge a capacitor load from 0 to 6 kV. A ferrite transformer steps up the DC input. The transformer primary is a full bridge configuration with the FET switches and the secondary is fed into a high voltage full wave rectifier whose output is connected directly to the energy storage capacitor. The peak current is held constant by varying the pulse width using predetermined timing resistors and counting pulses. The pulse width is increased as the capacitor charges to maintain peak current. A digital ripple counter counts pulses, and after the desired number is reached, an up-counter is clocked. The up-counter output is decoded to choose among different resistors used to discharge a timing capacitor, thereby determining the pulse width. A current latch shuts down the supply on overcurrent due to either excessive pulse width causing transformer saturation or a major bridge fault, i.e., FET or transformer failure, or failure of the drive circuitry.

  6. The width of gamma-ray burst spectra

    Science.gov (United States)

    Axelsson, Magnus; Borgonovo, Luis

    2015-03-01

    The emission processes active in the highly relativistic jets of gamma-ray bursts (GRBs) remain unknown. In this paper, we propose a new measure to describe spectra: the width of the EFE spectrum, a quantity dependent only on finding a good fit to the data. We apply this to the full sample of GRBs observed by Fermi/Gamma-ray Burst Monitor (GBM) and Compton Gamma-ray Observatory/Burst and Transient Source Experiment (BATSE). The results from the two instruments are fully consistent. We find that the median widths of spectra from long and short GRBs are significantly different (chance probability <10-6). The width does not correlate with either duration or hardness, and this is thus a new, independent distinction between the two classes. Comparing the measured spectra with widths of spectra from fundamental emission processes - synchrotron and blackbody radiation - the results indicate that a large fraction of GRB spectra are too narrow to be explained by synchrotron radiation from a distribution of electron energies: for example, 78 per cent of long GRBs and 85 per cent of short GRBs are incompatible with the minimum width of standard slow cooling synchrotron emission from a Maxwellian distribution of electrons, with fast cooling spectra predicting even wider spectra. Photospheric emission can explain the spectra if mechanisms are invoked to give a spectrum much broader than a blackbody.

  7. Thévenin equivalence in disorderless quantum networks

    Science.gov (United States)

    Cain, C. A.; Wu, C. H.

    2015-01-01

    We outline the procedure of extending the Thévenin equivalence principle for classical electric circuits to reducing Aharonov-Bohm-based quantum networks into equivalent models. With examples, we show from first principles how the requirements are related to the electron band structure's Fermi level and the lattice spacing of the network. Quantum networks of varying degrees of coupling strength from four basic classifications of single and double entangled loops sharing symmetry and highly correlated band structures are used to demonstrate the concept. We show the limitations of how the principle may be applied. Several classes of examples are given and their equivalent forms are shown.

  8. The dosimetric impact of leaf interdigitation and leaf width on VMAT treatment planning in Pinnacle: comparing Pareto fronts

    Science.gov (United States)

    van Kesteren, Z.; Janssen, T. M.; Damen, E.; van Vliet-Vroegindeweij, C.

    2012-05-01

    To evaluate in an objective way the effect of leaf interdigitation and leaf width on volumetric modulated arc therapy plans in Pinnacle. Three multileaf collimators (MLCs) were modeled: two 10 mm leaf width MLCs, with and without interdigitating leafs, and a 5 mm leaf width MLC with interdigitating leafs. Three rectum patients and three prostate patients were used for the planning study. In order to compare treatment techniques in an objective way, a Pareto front comparison was carried out. 200 plans were generated in an automated way, per patient per MLC model, resulting in a total of 3600 plans. From these plans, Pareto-optimal plans were selected which were evaluated for various dosimetric variables. The capability of leaf interdigitation showed little dosimetric impact on the treatment plans, when comparing the 10 mm leaf width MLC with and without leaf interdigitation. When comparing the 10 mm leaf width MLC with the 5 mm leaf width MLC, both with interdigitating leafs, improvement in plan quality was observed. For both patient groups, the integral dose was reduced by 0.6 J for the thin MLC. For the prostate patients, the mean dose to the anal sphincter was reduced by 1.8 Gy and the conformity of the V95% was reduced by 0.02 using the thin MLC. The V65% of the rectum was reduced by 0.1% and the dose homogeneity with 1.5%. For rectum patients, the mean dose to the bowel was reduced by 1.4 Gy and the mean dose to the bladder with 0.8 Gy for the thin MLC. The conformity of the V95% was equivalent for the 10 and 5 mm leaf width MLCs for the rectum patients. We have objectively compared three types of MLCs in a planning study for prostate and rectum patients by analyzing Pareto-optimal plans which were generated in an automated way. Interdigitation of MLC leafs does not generate better plans using the SmartArc algorithm in Pinnacle. Changing the MLC leaf width from 10 to 5 mm generates better treatment plans although the clinical relevance remains to be proven.

  9. The dosimetric impact of leaf interdigitation and leaf width on VMAT treatment planning in Pinnacle: comparing Pareto fronts

    International Nuclear Information System (INIS)

    To evaluate in an objective way the effect of leaf interdigitation and leaf width on volumetric modulated arc therapy plans in Pinnacle. Three multileaf collimators (MLCs) were modeled: two 10 mm leaf width MLCs, with and without interdigitating leafs, and a 5 mm leaf width MLC with interdigitating leafs. Three rectum patients and three prostate patients were used for the planning study. In order to compare treatment techniques in an objective way, a Pareto front comparison was carried out. 200 plans were generated in an automated way, per patient per MLC model, resulting in a total of 3600 plans. From these plans, Pareto-optimal plans were selected which were evaluated for various dosimetric variables. The capability of leaf interdigitation showed little dosimetric impact on the treatment plans, when comparing the 10 mm leaf width MLC with and without leaf interdigitation. When comparing the 10 mm leaf width MLC with the 5 mm leaf width MLC, both with interdigitating leafs, improvement in plan quality was observed. For both patient groups, the integral dose was reduced by 0.6 J for the thin MLC. For the prostate patients, the mean dose to the anal sphincter was reduced by 1.8 Gy and the conformity of the V95% was reduced by 0.02 using the thin MLC. The V65% of the rectum was reduced by 0.1% and the dose homogeneity with 1.5%. For rectum patients, the mean dose to the bowel was reduced by 1.4 Gy and the mean dose to the bladder with 0.8 Gy for thean dose to the bladder with 0.8 Gy for the thin MLC. The conformity of the V95% was equivalent for the 10 and 5 mm leaf width MLCs for the rectum patients. We have objectively compared three types of MLCs in a planning study for prostate and rectum patients by analyzing Pareto-optimal plans which were generated in an automated way. Interdigitation of MLC leafs does not generate better plans using the SmartArc algorithm in Pinnacle. Changing the MLC leaf width from 10 to 5 mm generates better treatment plans although the clinical relevance remains to be proven. (paper)

  10. Why momentum width matters for atom interferometry with Bragg pulses

    International Nuclear Information System (INIS)

    We theoretically consider the effect of the atomic source's momentum width on the efficiency of Bragg mirrors and beamsplitters and, more generally, on the phase sensitivity of Bragg pulse atom interferometers. By numerical optimization, we show that an atomic cloud's momentum width places a fundamental upper bound on the maximum transfer efficiency of a Bragg mirror pulse, and furthermore limits the phase sensitivity of a Bragg pulse atom interferometer. We quantify these momentum width effects, and precisely compute how mirror efficiencies and interferometer phase sensitivities vary as functions of Bragg order and source type. Our results and methodology allow for an efficient optimization of Bragg pulses and the comparison of different atomic sources, and will help in the design of large momentum transfer Bragg mirrors and beamsplitters for use in atom-based inertial sensors. (paper)

  11. Steganography in Arabic Text Using Zero Width and Kashidha Letters

    Directory of Open Access Journals (Sweden)

    Ammar Odeh

    2012-07-01

    Full Text Available The need for secure communication methods has significantly increased with the explosive growth of theinternet and mobile communications. The usage of text documents has doubled several times over the pastyears especially with mobile devices. In this paper we propose a new steganography algorithm for Arabictext. The algorithm employs some letters that can be joined with other letters. These letters are theextension letter, Kashida and Zero width character. The extension letter, Kashida, does not have anychange in the word meaning if joined to other letters. Also, the Zero width character (Ctrl+ Shift +1 doesnot change the meaning. The new proposed algorithm, Zero Width and Kashidha Letters (ZKS, mitigatethe possibility to be discovered by steganoanalysis through using parallel connection and permutationfunction.

  12. Morphodynamics structures induced by variations of the channel width

    Science.gov (United States)

    Duro, Gonzalo; Crosato, Alessandra; Tassi, Pablo

    2014-05-01

    In alluvial channels, forcing effects, such as a longitudinally varying width, can induce the formation of steady bars (Olesen, 1984). The type of bars that form, such as alternate, central or multiple, will mainly depend on the local flow width-to-depth ratio and on upstream conditions (Struiksma et al., 1985). The effects on bar formation of varying the channel width received attention only recently and investigations, based on flume experiments and mathematical modelling, are mostly restricted to small longitudinal sinusoidal variations of the channel width (e.g. Repetto et al., 2002; Wu and Yeh, 2005, Zolezzi et al., 2012; Frascati and Lanzoni, 2013). In this work, we analyze the variations in equilibrium bed topography in a longitudinal width-varying channel with characteristic scales of the Waal River (The Netherlands) using two different 2D depth-averaged morphodynamic models, one based on the Delft3D code and one on Telemac-Mascaret system. In particular, we explore the effects of changing the wavelength of sinusoidal width variations in a straight channel, focusing on the effects of the spatial lag between bar formation and forcing that is observed in numerical models and laboratory experiments (e.g. Crosato et al, 2011). We extend the investigations to finite width variations in which longitudinal changes of the width-to-depth ratio are such that they may affect the type of bars that become unstable (alternate, central or multiple bars). Numerical results are qualitatively validated with field observations and the resulting morphodynamic pattern is compared with the physics-based predictor of river bar modes by Crosato and Mosselman (2009). The numerical models are finally used to analyse the experimental conditions of Wu and Yeh (2005). The study should be seen as merely exploratory. The aim is to investigate possible approaches for future research aiming at assessing the effects of artificial river widening and narrowing to control bar formation in alluvial rivers. References Crosato A. and Mosselman E., 2009. Simple physics-based predictor for the number of river bars and the transition between meandering and braiding. Water Resources Research, 45, W03424, doi: 10.1029/2008WR007242. Crosato A., Mosselman E., Desta F.B. and Uijttewaal W.S.J., 2011. Experimental and numerical evidence for intrinsic nonmigrating bars in alluvial channels. Water Resources Research, AGU, 47(3), W03511, doi 10.1029/2010WR009714. Frascati A. and Lanzoni S., 2013. A mathematical model for meandering rivers with varying width. J. Geophys. Res.Earth Surf., 118, doi:10.1002/jgrf.20084. Olesen K.W., 1984. Alternate bars in and meandering of alluvial rivers. In: River Meandering, Proc. of the Conf. Rivers '83, 24-26 Oct. 1983, New Orleans, Louisiana, U.S.A., ed. Elliott C.M., pp. 873-884, ASCE, New York. ISBN 0-87262-393-9. Repetto R., Tubino, M. and Paola C., 2002. Planimetric instability of channels with variable width. J. Fluid Mech., 457, 79-109. Struiksma N., Olesen K.W., Flokstra C. and De Vriend H.J., 1985. Bed deformation in curved alluvial channels. J. Hydraul. Res., 23(1), 57- 79. Wu F.-C. and Yeh T.-H., 2005. Forced bars induced by variations of channel width: Implications for incipient bifurcation. J. Geophys. Res., 110, F02009, doi:10.1029/2004JF000160. Zolezzi, G., R. Luchi, and M. Tubino (2012), Modeling morphodynamic processes in meandering rivers with spatial width variations, Rev. Geophys., 50, RG4005, doi:10.1029/2012RG000392.

  13. Domain Wall Width in Different Ferroelectrics via Perturbation Route

    Directory of Open Access Journals (Sweden)

    Pratap C. Ray

    2012-05-01

    Full Text Available The domains are of fundamental interest for engineering a ferroelectric material. The domain wall and its width control the ferroelectric behavior to a great extent. The stability of polarization in the context of Landau-Ginzburg free energy functional has been worked out in a previous work by a perturbation approach, where two limits of domain wall width were estimated within the stability zone and they were also found to correspond well with the data on lithium niobate and lithium tantalate. In the present work, it is shown that this model is valid for a wide range of ferroelectric materials and also for a given ferroelectric, such as lithium niobate with different levels of impurities, which are known to affect the domain wall width.

  14. The width of the $\\omega$ meson in dense matter

    CERN Document Server

    Tolos, Laura; Oset, Eulogio; Ramos, Angels

    2014-01-01

    We obtain the width of the $\\omega$ meson in dense nuclear matter by taking into account (i) the free decay of the $\\omega$ into three pions, which is dominated by $\\rho \\pi$ mode, (ii) the processes induced by a vector-baryon interaction dominated by vector meson exchange, and (iii) the $\\omega \\to K \\bar K$ mechanism in matter. The $\\omega$ meson develops an important width in matter, coming from the dominant $\\omega \\to \\rho\\pi$ decay mode, with a value of $121 \\pm 10$ MeV at normal nuclear matter density for an $\\omega$ at rest. At finite momentum, the width of the $\\omega$ meson increases moderately with values of 200 MeV at 600 MeV/c.

  15. Analysis on Longitudinal Dose according to Change of Field Width

    International Nuclear Information System (INIS)

    To analyze the accuracy of tumor volume dose following field width change, to check the difference of dose change by using self-made moving car, and to evaluate practical delivery tumor dose when tomotherapy in the treatment of organ influenced by breathing. By using self-made moving car, the difference of longitudinal movement (0.0 cm, 1.0 cm, 1.5 cm, 2.0 cm) was applied and compared calculated dose with measured dose according to change of field width (1.05 cm, 2.50 cm, 5.02 cm) and apprehended margin of error. Then done comparative analysis in degree of photosensitivity of DQA film measured by using Gafchromic EBT film. Dose profile and Gamma histogram were used to measure degree of photosensitivity of DQA film. When field width were 1.05 cm, 2.50 cm, 5.02 cm, margin of error of dose delivery coefficient was -2.00%, -0.39%, -2.55%. In dose profile of Gafchromic EBT film's analysis, the movement of moving car had greater motion toward longitudinal direction and as field width was narrower, big error increased considerably at high dose part compared to calculated dose. The more field width was narrowed, gamma index had a large considerable influence of moving at gamma histogram. We could check the difference of longitudinal dose of moving organ. In order to small field width and minimize organ moving due to breathing, it is thought to be needed to develop breathing control unit and fixation tool.

  16. Analysis on Longitudinal Dose according to Change of Field Width

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Won Seok; Shin, Ryung Mi; Oh, Byung Cheon; Jo, Jun Young; Kim, Gi Chul; Choi, Tae Gu [Dept. of Radiation Oncology, Kyunghee University Hospital, Seoul (Korea, Republic of); Back, Jong Geal [Dept. of Radiation Oncology, Yensei Caner Center, Seoul (Korea, Republic of)

    2011-09-15

    To analyze the accuracy of tumor volume dose following field width change, to check the difference of dose change by using self-made moving car, and to evaluate practical delivery tumor dose when tomotherapy in the treatment of organ influenced by breathing. By using self-made moving car, the difference of longitudinal movement (0.0 cm, 1.0 cm, 1.5 cm, 2.0 cm) was applied and compared calculated dose with measured dose according to change of field width (1.05 cm, 2.50 cm, 5.02 cm) and apprehended margin of error. Then done comparative analysis in degree of photosensitivity of DQA film measured by using Gafchromic EBT film. Dose profile and Gamma histogram were used to measure degree of photosensitivity of DQA film. When field width were 1.05 cm, 2.50 cm, 5.02 cm, margin of error of dose delivery coefficient was -2.00%, -0.39%, -2.55%. In dose profile of Gafchromic EBT film's analysis, the movement of moving car had greater motion toward longitudinal direction and as field width was narrower, big error increased considerably at high dose part compared to calculated dose. The more field width was narrowed, gamma index had a large considerable influence of moving at gamma histogram. We could check the difference of longitudinal dose of moving organ. In order to small field width and minimize organ moving due to breathing, it is thought to be needed to develop breathing control unit and fixation tool.

  17. Fjords in viscous fingering: selection of width and opening scale

    Energy Technology Data Exchange (ETDEWEB)

    Mineev-weinstein, Mark [Los Alamos National Laboratory; Ristroph, Leif [UT-AUSTIN; Thrasher, Matthew [UT-AUSTIN; Swinney, Harry [UT-AUSTIN

    2008-01-01

    Our experiments on viscous fingering of air into oil contained between closely spaced plates reveal two selection rules for the fjords of oil that separate fingers of air. (Fjords are the building blocks of solutions of the zero-surface-tension Laplacian growth equation.) Experiments in rectangular and circular geometries yield fjords with base widths {lambda}{sub c}/2, where {lambda}{sub c} is the most unstable wavelength from a linear stability analysis. Further, fjords open at an angle of 8.0{sup o}{+-}1.0{sup o}. These selection rules hold for a wide range of pumping rates and fjord lengths, widths, and directions.

  18. Experimental research methodology crack opening width of reinforced concrete elements

    Directory of Open Access Journals (Sweden)

    ?.?. ????????

    2006-01-01

    Full Text Available  The tasks of experimental researches have been formulated, basic of which are: definition of width  disclosing  cracks at a level of the working fixture and in several levels above the stretched fixture; changes of distance between cracks and length of cracks in process of increase of loading with check of multilevel process of formation cracks; definition of deformations of the fixture and concrete with deformation account of effect in a vicinity of a two-console element. The technique of experimental researches of width of disclosing cracks of ferro-concrete designs from a position of the mechanics destruction is developed which has allowed to decide the put tasks.

  19. Energy and decay width of the {pi}K atom

    Energy Technology Data Exchange (ETDEWEB)

    Jallouli, H. [Centre National des Sciences et Technologies Nucleaires, Technopole Sidi Thabet (Tunisia); Sazdjian, H. [Universite Paris XI, Institut de Physique Nucleaire, Groupe de Physique Theorique, Orsay Cedex (France)

    2006-11-15

    The energy and the decay width of the {pi}K atom are evaluated in the framework of the quasipotential-constraint theory approach. The main electromagnetic and isospin symmetry breaking corrections to the lowest-order formulas for the energy shift from the Coulomb binding energy and for the decay width are calculated. They are estimated to be of the order of a few per cent. We display formulas to extract the strong interaction S-wave {pi}K scattering lengths from future experimental data concerning the {pi}K atom. (orig.)

  20. Measuring slit width and separation in a diffraction experiment

    Energy Technology Data Exchange (ETDEWEB)

    Gan, K K; Law, A T [Department of Physics, Ohio State University, Columbus, OH 43210 (United States)], E-mail: gan@mps.ohio-state.edu

    2009-11-15

    We present a procedure for measuring slit width and separation in single- and double-slit diffraction experiments. Intensity spectra of diffracted laser light are measured with an optical sensor (PIN diode). Slit widths and separations are extracted by fitting to the measured spectra. We present a simple fitting procedure to account for the integration (averaging) of light across the finite sensor aperture. This experiment provides students with a quantitative, in-depth verification of diffraction theory, as well as hands-on experience in sophisticated fitting methods.

  1. Influence of weather on cork-ring width.

    Science.gov (United States)

    Caritat, A; Gutiérrez, E; Molinas, M

    2000-07-01

    Ring-width series of cork from Quercus suber L. trees growing at two sites in Extremadura (southwestern Spain) were analyzed in relation to monthly precipitation and temperature, and to climatic indices combining both variables. Ring width of cork showed strong positive correlations with precipitation, especially during the fall and winter. Moderately low temperatures were favorable for cork growth, except in winter and during the onset of phellogen activity. We conclude that drought or temperature, or both, can limit cork growth during the annual drought period. PMID:11303579

  2. Fjords in viscous fingering: selection of width and opening angle

    CERN Document Server

    Ristroph, L; Mineev-Weinstein, M B; Swinney, H L; Ristroph, Leif; Thrasher, Matthew; Mineev-Weinstein, Mark B.; Swinney, Harry L.

    2005-01-01

    Our experiments on viscous fingering of air into oil contained between closely spaced plates reveal two selection rules for the fjords of oil that separate fingers of air. (Fjords are the building blocks of solutions of the zero surface tension Laplacian growth equation.) Experiments in rectangular and circular geometries yield fjords with base widths 1/2 lambda_c, where lambda_c is the most unstable wavelength from a linear stability analysis. Further, fjords open at an angle of 8.0 degrees plus or minus 1.0 degree. These selection rules hold for a wide range of pumping rates and fjord lengths, widths, and directions.

  3. Fjords in viscous fingering: selection of width and opening angle.

    Science.gov (United States)

    Ristroph, Leif; Thrasher, Matthew; Mineev-Weinstein, Mark B; Swinney, Harry L

    2006-07-01

    Our experiments on viscous fingering of air into oil contained between closely spaced plates reveal two selection rules for the fjords of oil that separate fingers of air. (Fjords are the building blocks of solutions of the zero-surface-tension Laplacian growth equation.) Experiments in rectangular and circular geometries yield fjords with base widths lambda(c)/2, where lambda(c) is the most unstable wavelength from a linear stability analysis. Further, fjords open at an angle of 8.0 degrees +/- 1.0 degree. These selection rules hold for a wide range of pumping rates and fjord lengths, widths, and directions. PMID:16907143

  4. Statistical analysis of s-wave neutron reduced widths

    International Nuclear Information System (INIS)

    The fluctuations of the s-wave neutron reduced widths for many nuclei have been analyzed with emphasis on recent measurements by a statistical procedure which is based on the method of maximum likelihood. It is shown that the s-wave neutron reduced widths of nuclei follow single channel Porter Thomas distribution (x2-distribution with degree of freedom ? = 1) for most of the cases. However there are apparent deviations from ? = 1 and possible explanation and significance of this deviation is given. These considerations are likely to modify the evaluation of neutron cross section. (author)

  5. CP violation and the width Z --> b$\\overline{b}$

    CERN Document Server

    Bernreuther, W; Bruss, D; Haberl, P; Nachtmann, O; Bernreuther, W; Botz, G W; Bruß, D; Haberl, P; Nachtmann, O

    1994-01-01

    We discuss the effect of CP-violating Zb\\bar{b}, Zb\\bar{b}G and Zb\\bar{b}\\gamma couplings on the width \\Gamma(Z\\rightarrow b\\bar bX). The presence of such couplings leads in a natural way to an increase of this width relative to the prediction of the standard model. Various strategies of a direct search for such CP-violating couplings by using CP-odd observables are outlined. The number of Z bosons required to obtain significant information on the couplings in this way is well within the reach of present LEP experiments.

  6. Domain wall width of lithium niobate poled during growth

    CERN Document Server

    Brooks, R; Hole, D E; Callejo, D; Bermudez, V; Diéguez, E

    2003-01-01

    Good quality crystals of periodically poled lithium niobate can be generated directly during growth. However, the temperature gradients at the zone boundaries define the width of the regions where the polarity is reversed. Hence, the region influenced the domain transition may be a significant fraction of the overall poling period for material poled during growth. Evidence for the scale of this feature is reported both by chemical etching and by the less common method of ion beam luminescence and the 'domain wall' width approximately 1 mu m for these analyses. The influence of the reversal region may differ for alternative techniques but the relevance to device design for second harmonic generation is noted.

  7. Analyzing crack width to predict corrosion in reinforced concrete

    International Nuclear Information System (INIS)

    Our aim in this paper is to introduce a set of relationships linking the distribution of reinforcement corrosion and the width of cover crack that results from such corrosion. This work is based on experimental results obtained on the longitudinal reinforcements of two beams naturally corroded over periods of 14 and 17 years. We first compared these experimental results with existing models linking crack width and attack penetration. Noting that such models only partially predict actual experimental data, we put forward a new model using the parameter of reinforcement cross-section loss

  8. Direct measurement of the W boson decay width

    Science.gov (United States)

    Abazov, V. M.; Abbott, B.; Abdesselam, A.; Abolins, M.; Abramov, V.; Acharya, B. S.; Adams, D. L.; Adams, M.; Ahmed, S. N.; Alexeev, G. D.; Alton, A.; Alves, G. A.; Anderson, E. W.; Arnoud, Y.; Avila, C.; Baarmand, M. M.; Babintsev, V. V.; Babukhadia, L.; Bacon, T. C.; Baden, A.; Baldin, B.; Balm, P. W.; Banerjee, S.; Barberis, E.; Baringer, P.; Barreto, J.; Bartlett, J. F.; Bassler, U.; Bauer, D.; Bean, A.; Beaudette, F.; Begel, M.; Belyaev, A.; Beri, S. B.; Bernardi, G.; Bertram, I.; Besson, A.; Beuselinck, R.; Bezzubov, V. A.; Bhat, P. C.; Bhatnagar, V.; Bhattacharjee, M.; Blazey, G.; Blekman, F.; Blessing, S.; Boehnlein, A.; Bojko, N. I.; Bolton, T. A.; Borcherding, F.; Bos, K.; Bose, T.; Brandt, A.; Breedon, R.; Briskin, G.; Brock, R.; Brooijmans, G.; Bross, A.; Buchholz, D.; Buehler, M.; Buescher, V.; Burtovoi, V. S.; Butler, J. M.; Canelli, F.; Carvalho, W.; Casey, D.; Casilum, Z.; Castilla-Valdez, H.; Chakraborty, D.; Chan, K. M.; Chekulaev, S. V.; Cho, D. K.; Choi, S.; Chopra, S.; Christenson, J. H.; Chung, M.; Claes, D.; Clark, A. R.; Coney, L.; Connolly, B.; Cooper, W. E.; Coppage, D.; Crépé-Renaudin, S.; Cummings, M. A.; Cutts, D.; Davis, G. A.; de, K.; de Jong, S. J.; Demarteau, M.; Demina, R.; Demine, P.; Denisov, D.; Denisov, S. P.; Desai, S.; Diehl, H. T.; Diesburg, M.; Doulas, S.; Ducros, Y.; Dudko, L. V.; Duensing, S.; Duflot, L.; Dugad, S. R.; Duperrin, A.; Dyshkant, A.; Edmunds, D.; Ellison, J.; Eltzroth, J. T.; Elvira, V. D.; Engelmann, R.; Eno, S.; Eppley, G.; Ermolov, P.; Eroshin, O. V.; Estrada, J.; Evans, H.; Evdokimov, V. N.; Fahland, T.; Fein, D.; Ferbel, T.; Filthaut, F.; Fisk, H. E.; Fisyak, Y.; Flattum, E.; Fleuret, F.; Fortner, M.; Fox, H.; Frame, K. C.; Fu, S.; Fuess, S.; Gallas, E.; Galyaev, A. N.; Gao, M.; Gavrilov, V.; Genik, R. J.; Genser, K.; Gerber, C. E.; Gershtein, Y.; Gilmartin, R.; Ginther, G.; Gómez, B.; Goncharov, P. I.; González Solís, J. L.; Gordon, H.; Goss, L. T.; Gounder, K.; Goussiou, A.; Graf, N.; Grannis, P. D.; Green, J. A.; Greenlee, H.; Greenwood, Z. D.; Grinstein, S.; Groer, L.; Grünendahl, S.; Gupta, A.; Gurzhiev, S. N.; Gutierrez, G.; Gutierrez, P.; Hadley, N. J.; Haggerty, H.; Hagopian, S.; Hagopian, V.; Hall, R. E.; Hansen, S.; Hauptman, J. M.; Hays, C.; Hebert, C.; Hedin, D.; Heinmiller, J. M.; Heinson, A. P.; Heintz, U.; Hildreth, M. D.; Hirosky, R.; Hobbs, J. D.; Hoeneisen, B.; Huang, Y.; Iashvili, I.; Illingworth, R.; Ito, A. S.; Jaffré, M.; Jain, S.; Jesik, R.; Johns, K.; Johnson, M.; Jonckheere, A.; Jöstlein, H.; Juste, A.; Kahl, W.; Kahn, S.; Kajfasz, E.; Kalinin, A. M.; Karmanov, D.; Karmgard, D.; Kehoe, R.; Khanov, A.; Kharchilava, A.; Kim, S. K.; Klima, B.; Knuteson, B.; Ko, W.; Kohli, J. M.; Kostritskiy, A. V.; Kotcher, J.; Kothari, B.; Kotwal, A. V.; Kozelov, A. V.; Kozlovsky, E. A.; Krane, J.; Krishnaswamy, M. R.; Krivkova, P.; Krzywdzinski, S.; Kubantsev, M.; Kuleshov, S.; Kulik, Y.; Kunori, S.; Kupco, A.; Kuznetsov, V. E.; Landsberg, G.; Lee, W. M.; Leflat, A.; Leggett, C.; Lehner, F.; Leonidopoulos, C.; Li, J.; Li, Q. Z.; Lima, J. G.; Lincoln, D.; Linn, S. L.; Linnemann, J.; Lipton, R.; Lucotte, A.; Lueking, L.; Lundstedt, C.; Luo, C.; Maciel, A. K.; Madaras, R. J.; Malyshev, V. L.; Manankov, V.; Mao, H. S.; Marshall, T.; Martin, M. I.; Mayorov, A. A.; McCarthy, R.; McMahon, T.; Melanson, H. L.; Merkin, M.; Merritt, K. W.; Miao, C.; Miettinen, H.; Mihalcea, D.; Mishra, C. S.; Mokhov, N.; Mondal, N. K.; Montgomery, H. E.; Moore, R. W.; Mostafa, M.; da Motta, H.; Mutaf, Y.; Nagy, E.; Nang, F.; Narain, M.; Narasimham, V. S.; Naumann, N. A.; Neal, H. A.; Negret, J. P.; Nomerotski, A.; Nunnemann, T.; O'Neil, D.; Oguri, V.; Olivier, B.; Oshima, N.; Padley, P.; Pan, L. J.; Papageorgiou, K.; Parashar, N.; Partridge, R.; Parua, N.; Paterno, M.; Patwa, A.; Pawlik, B.; Peters, O.; Pétroff, P.; Piegaia, R.; Pope, B. G.; Popkov, E.; Prosper, H. B.; Protopopescu, S.; Przybycien, M. B.; Qian, J.; Raja, R.; Rajagopalan, S.; Ramberg, E.; Rapidis, P. A.; Reay, N. W.; Reucroft, S.; Ridel, M.; Rijssenbeek, M.; Rizatdinova, F.; Rockwell, T.; Roco, M.; Royon, C.; Rubinov, P.; Ruchti, R.; Rutherfoord, J.; Sabirov, B. M.; Sajot, G.; Santoro, A.; Sawyer, L.; Schamberger, R. D.; Schellman, H.; Schwartzman, A.; Sen, N.; Shabalina, E.; Shivpuri, R. K.; Shpakov, D.; Shupe, M.; Sidwell, R. A.; Simak, V.; Singh, H.; Sirotenko, V.; Slattery, P.; Smith, E.; Smith, R. P.; Snihur, R.; Snow, G. R.; Snow, J.; Snyder, S.; Solomon, J.; Song, Y.; Sorín, V.; Sosebee, M.; Sotnikova, N.; Soustruznik, K.; Souza, M.; Stanton, N. R.; Steinbrück, G.; Stephens, R. W.; Stoker, D.; Stolin, V.; Stone, A.; Stoyanova, D. A.; Strang, M. A.; Strauss, M.; Strovink, M.; Stutte, L.; Sznajder, A.; Talby, M.; Taylor, W.; Tentindo-Repond, S.; Tripathi, S. M.; Trippe, T. G.

    2002-08-01

    Based on 85 pb-1 data of pp¯ collisions at (s)=1.8 TeV collected using the DØ detector at Fermilab during the 1994-1995 run of the Tevatron, we present a direct measurement of the total decay width of the W boson ?W. The width is determined from the transverse mass spectrum in the W-->e+?e decay channel and found to be ?W=2.23+0.15- 0.14(stat)+/-0.10(syst) GeV, consistent with the expectation from the standard model.

  9. Influence of downcomer volume and gap width on blowdown

    International Nuclear Information System (INIS)

    Experimental results from two LOBI large break blowdown/refill tests, with different downcomer volumes and gap widths, have been analysed. Both tests, which simulated a 2A offset shear break in the cold leg pipe of a PWR, were performed with nearly the same initial and boundary conditions. The experimental data show a strong influence of the downcomer volume and gap width on the thermo-hydraulic behaviour of the system during the blowdown and refill period of the transient. The analysis of the reasons for this different behaviour is supported by results from RELAP4/Mod 6 test predictions which, in general, agree well with the measured data

  10. Measurements of neutron dose equivalent for a proton therapy center using uniform scanning proton beams

    Energy Technology Data Exchange (ETDEWEB)

    Zheng Yuanshui; Liu Yaxi; Zeidan, Omar; Schreuder, Andries Niek; Keole, Sameer [ProCure Proton Therapy Center, 5901 West Memorial Road, Oklahoma City, Oklahoma 73142 (United States); INTEGRIS Cancer Insititute, 5911 West Memorial Road, Oklahoma City, Oklahoma 73142 (United States); ProCure Proton Therapy Center, 5901 West Memorial Road, Oklahoma City, Oklahoma 73142 (United States); ProCure Treatment Centers, 420 North Walnut Street, Bloomington, Indiana 47404 (United States); ProCure Proton Therapy Center, 5901 West Memorial Road, Oklahoma City, Oklahoma 73142 (United States)

    2012-06-15

    Purpose: Neutron exposure is of concern in proton therapy, and varies with beam delivery technique, nozzle design, and treatment conditions. Uniform scanning is an emerging treatment technique in proton therapy, but neutron exposure for this technique has not been fully studied. The purpose of this study is to investigate the neutron dose equivalent per therapeutic dose, H/D, under various treatment conditions for uniform scanning beams employed at our proton therapy center. Methods: Using a wide energy neutron dose equivalent detector (SWENDI-II, ThermoScientific, MA), the authors measured H/D at 50 cm lateral to the isocenter as a function of proton range, modulation width, beam scanning area, collimated field size, and snout position. They also studied the influence of other factors on neutron dose equivalent, such as aperture material, the presence of a compensator, and measurement locations. They measured H/D for various treatment sites using patient-specific treatment parameters. Finally, they compared H/D values for various beam delivery techniques at various facilities under similar conditions. Results: H/D increased rapidly with proton range and modulation width, varying from about 0.2 mSv/Gy for a 5 cm range and 2 cm modulation width beam to 2.7 mSv/Gy for a 30 cm range and 30 cm modulation width beam when 18 Multiplication-Sign 18 cm{sup 2} uniform scanning beams were used. H/D increased linearly with the beam scanning area, and decreased slowly with aperture size and snout retraction. The presence of a compensator reduced the H/D slightly compared with that without a compensator present. Aperture material and compensator material also have an influence on neutron dose equivalent, but the influence is relatively small. H/D varied from about 0.5 mSv/Gy for a brain tumor treatment to about 3.5 mSv/Gy for a pelvic case. Conclusions: This study presents H/D as a function of various treatment parameters for uniform scanning proton beams. For similar treatment conditions, the H/D value per uncollimated beam size for uniform scanning beams was slightly lower than that from a passive scattering beam and higher than that from a pencil beam scanning beam, within a factor of 2. Minimizing beam scanning area could effectively reduce neutron dose equivalent for uniform scanning beams, down to the level close to pencil beam scanning.

  11. Equivalence Principle, Higgs Boson and Cosmology

    Directory of Open Access Journals (Sweden)

    Mauro Francaviglia

    2013-05-01

    Full Text Available We discuss here possible tests for Palatini f(R-theories together with their implications for different formulations of the Equivalence Principle. We shall show that Palatini f(R-theories obey the Weak Equivalence Principle and violate the Strong Equivalence Principle. The violations of the Strong Equivalence Principle vanish in vacuum (and purely electromagnetic solutions as well as on short time scales with respect to the age of the universe. However, we suggest that a framework based on Palatini f(R-theories is more general than standard General Relativity (GR and it sheds light on the interpretation of data and results in a way which is more model independent than standard GR itself.

  12. The Economist Interactive: Equivalent Country Comparisons

    Science.gov (United States)

    This interactive tools allows the user to learn which countries parallel the states, provinces or territories of the United States, China, India and Brazil and  presents country equivalent data for both GDP and population.

  13. 21 CFR 26.6 - Equivalence assessment.

    Science.gov (United States)

    2010-04-01

    ...REPORTS, MEDICAL DEVICE QUALITY SYSTEM AUDIT REPORTS, AND CERTAIN MEDICAL...equivalence of the respective regulatory systems in terms of quality assurance...purpose of assessing regulatory systems and the authorities'...

  14. Fluctuation of Dirac operator and equivalence principle

    OpenAIRE

    Marciante, Mathieu; Schu?cker, Thomas

    2012-01-01

    General Relativity formulated with Noncommutative geometry allows one to obtain, via the fluctuation of Dirac operator, an exact equivalence principle: generation of curvature and torsion from flat space. The fluctuation method presented in this report is applied on two examples.

  15. S-equivalents lagrangians in generalized mechanics

    International Nuclear Information System (INIS)

    The problem of s-equivalent lagrangians is considered in the realm of generalized mechanics. Some results corresponding to the ordinary (non-generalized) mechanics are extended to the generalized case. A theorem for the reduction of the higher order lagrangian description to the usual order is found to be useful for the analysis of generalized mechanical systems and leads to a new class of equivalence between lagrangian functions. Some new perspectives are pointed out. (Author)

  16. AF-equivalence relations and their cocycles

    OpenAIRE

    Renault, Jean

    2001-01-01

    After a review of some of the main results about hyperfinite equivalence relations and their cocycles in the measured setting, we give a definition of a topological AF-equivalence relation. We show that every cocycle is cohomologous to a quasi-product cocycle. We then study the problem of determining the quasi-invariant probability measures admitting a given cocycle as their Radon-Nikodym derivative.

  17. Nielsen equivalence in Gupta-Sidki groups

    OpenAIRE

    Myropolska, Aglaia

    2014-01-01

    For a group $G$ generated by $k$ elements, the Nielsen equivalence classes are defined as orbits of the action of $\\operatorname{Aut} F_k$, the automorphism group of the free group of rank $k$, on the set of generating $k$-tuples of $G$. Let $p\\geq 3$ be prime and $G_p$ the Gupta-Sidki $p$-group. We prove that there are infinitely many Nielsen equivalence classes on generating pairs of $G_p$.

  18. On the generation of equivalent hamiltonians

    International Nuclear Information System (INIS)

    A new approach to the equivalence problem (in phase space) is presented. Given a Hamiltonian describing a system of particles with two degrees of freedom (and the corresponding Hamilton-Jacobi equation), it is shown how to find the most general family of Hamiltonian functions that generates new Hamilton-Jacobi equation with the following (and essential) characteristic, here defined as equivalence: every new solution is also a solution of the original Hamilton-Jacobi equation and vice-versa. (Author)

  19. Equivalent circuit model of radiative heat transfer

    OpenAIRE

    Maslovski, Stanislav I.; Simovski, Constantin R.; Tretyakov, Sergei A.

    2012-01-01

    Here, we develop a theory of radiative heat transfer based on an equivalent electrical network representation for the hot material slabs in an arbitrary multilayered environment with arbitrary distribution of temperatures and electromagnetic properties among the layers. Our approach is fully equivalent to the known theories operating with the fluctuating current density, while being significantly simpler in analysis and applications. A practical example of the near-infrared ...

  20. Some new equivalences of Anderson's paving conjectures

    OpenAIRE

    Paulsen, Vern I.; Raghupathi, Mrinal

    2007-01-01

    Anderson's paving conjectures are known to be equivalent to the Kadison-Singer problem. We prove some new equivalences of Anderson's conjectures that require the paving of smaller sets of matrices. We prove that if the strictly upper triangular operatorss are pavable, then every 0 diagonal operator is pavable. This result follows from a new paving condition for positive operators. In addition, we prove that if the upper triangular Toeplitz operators are paveable, then all To...

  1. Mimicking Meaningfulness:stimulus equivalence and meaning

    OpenAIRE

    Nartey, Richard Korley

    2010-01-01

    The current paper reflects on some of the basic issues in the concept of stimulus equivalence as proposed by Murray Sidman. The paired-associate paradigm was the predominant method being employed to demonstrate how organisms come to treat dissimilar events that had not been related before as if they were the same. Several papers by Murray Sidman after the demise of the pair-associates methodology brought a paradigm shift in stimulus equivalence research from the paired-associates realm to the...

  2. Automorphic equivalence of one-sorted algebras

    OpenAIRE

    Tsurkov, A.

    2005-01-01

    One of the central questions of universal algebraic geometry is: when two algebras have the same algebraic geometry? There are various interpretations of the sentence "Two algebras have the same algebraic geometry". One of these is automorphic equivalence of algebras, which is discussed in this paper, and the other interpretation is geometric equivalence of algebras. In this paper we consider very wide and natural class of algebras: one sorted algebras from IBN variety. The ...

  3. Explicit Homotopy Equivalences Between Some Operads

    CERN Document Server

    Hoefel, Eduardo

    2011-01-01

    In this work we present an explicit operad morphism that is also a homotopy equivalence between the operad given by the real Fulton MacPherson compactification of configuration spaces and the little $n$-disks operad. In particular, the construction gives an operadic homotopy equivalence between the associahedra and the little intervals explicitly. It can also be extended to the case of Kontsevich compactification and Voronov swiss-cheese operad.

  4. Dark matter and the equivalence principle

    Science.gov (United States)

    Frieman, Joshua A.; Gradwohl, Ben-Ami

    1993-01-01

    A survey is presented of the current understanding of dark matter invoked by astrophysical theory and cosmology. Einstein's equivalence principle asserts that local measurements cannot distinguish a system at rest in a gravitational field from one that is in uniform acceleration in empty space. Recent test-methods for the equivalence principle are presently discussed as bases for testing of dark matter scenarios involving the long-range forces between either baryonic or nonbaryonic dark matter and ordinary matter.

  5. Using Constraints for Equivalent Mutant Detection

    OpenAIRE

    Simona Nica; Franz Wotawa

    2012-01-01

    In mutation testing the question whether a mutant is equivalent to its program is important in order to compute the correct mutation score. Unfortunately, answering this question is not always possible and can hardly be obtained just by having a look at the program's structure. In this paper we introduce a method for solving the equivalent mutant problem using a constraint representation of the program and its mutant. In particularly the approach is based on distinguishing t...

  6. Multiresolution weighted norm equivalences and applications

    OpenAIRE

    Beuchler, Sven; Schneider, Reinhold; Schwab, Christoph

    2006-01-01

    We establish multiresolution norm equivalences in weighted spaces L2w((0,1)) with possibly singular weight functions w(x)?0 in (0,1). Our analysis exploits the locality of the biorthogonal wavelet basis and its dual basis functions. The discrete norms are sums of wavelet coefficients which are weighted with respect to the collocated weight function w(x) within each scale. Since norm equivalences for Sobolev norms are by now well-known, our result can...

  7. Personnel monitors utilizing tissue equivalent proportional counters

    International Nuclear Information System (INIS)

    The U.S. Department of Energy has established a program to improve neutron dosimetry at facilities where a significant number of workers are exposed to fast neutrons from handling isotopic neutron sources. One facet of this program is the development of small, lightweight personnel monitors to determine dose equivalent as the workers are exposed. These instruments use small cylindrical tissue equivalent proportional counters to detect neutrons, and a microprocessor to determine absorbed dose and dose equivalent. A Pocket REM Meter containing three cylindrical tissue equivalent proportional counters 1.9-cm in diameter and 13-cm long is developed. The instrument utilizes hybrid circuitry and a 256 channel analog to digital converter to supply signals to a CMOS microprocessor, which calculates absorbed dose and dose equivalent for neutrons and displays the results on a liquid crystal display. Independent measurements at the Pacific Northwest Laboratory verified that the Pocket REM Meter is accurate within 20% for determining neutron dose equivalent when exposed to unmoderated or slightly moderated Cf-252 sources, which have been calibrated by the U.S. National Bureau of Standards. The Laboratory is developing a Total Dose Meter to measure absorbed dose and determine dose equivalent from mixed radiation fields of neutrons and gamma rays. Using a single tissue equivalent proportional counter with two amplifiers operated at different gains. Using empirical algorithms derived from exposures to monoenergetic neutrons, it is possible to determine quality factors within about 7% for neutrons with energies between 200 KeV and 7.5 MeV

  8. Personnel monitors utilizing tissue equivalent proportional counters

    International Nuclear Information System (INIS)

    In the United States, the Department of Energy has established a program to improve neutron dosimetry at facilities where a significant number of workers are exposed to fast neutrons from handling isotopic neutron sources. One facet of this program is the development of small, lightweight personnel monitors to determine dose equivalent as the workers are exposed. These instruments use small cylindrical tissue equivalent proportional counters to detect neutrons, and a microprocessor to determine absorbed dose and dose equivalent. A ''Pocket REM Meter'' has been developed containing three cylindrical tissue equivalent proportional counters 1.9-cm in diameter and 13-cm long. The instrument utilizes hybrid circuitry and a 256 channel analog to digital converter to supply signals to a CMOS microprocessor, which calculates absorbed dose and dose equivalent for neutrons and displays the results on a liquid crystal display. The instrument weighs 630 grams, is 15-cm by 7.6 cm by 20-cm in size, and operates 40 hours on a 9-volt battery. Independent measurements verified that the ''Pocket REM Meter'' is accurate within 20% for determining neutron dose equivalent when exposed to unmoderated or slightly moderated Cf-252 sources, which have been calibrated by the US National Bureau of Standards. A ''Total Dose Meter'' is being developed to measure absorbed dose and determine dose equivalent from mixed radiation fields of neutrons and gamma rays. Using a single tissue equivalent proportional counter with two amplifiers operated at different gains, it is possible to measure the wide range of event sizes from mixed fields and determine absorbed dose. Using empirical algorithms derived from exposures to monoenergetic neutrons, it is possible to determine quality factors within about 7% for neutrons with energies btween 200 keV and 7.5 MeV

  9. Dose equivalent rate calculation tool for FBFC

    International Nuclear Information System (INIS)

    The authors present the results obtained by a software designed to compute dose equivalent rate for the critical workstations of the FBFC plant in Romans, France, which will have to deal with an uranium more heavily loaded with U232. The uranium spectrum and the ageing time can be varied in order to visualize the evolution of the dose equivalent rate in different locations with respect to the ageing time

  10. Fiscal adjustments in Europe and Ricardian equivalence

    OpenAIRE

    Bonis, V.; Paladini, R.

    1998-01-01

    According to the ‘Ricardian’ equivalence hypothesis, consumption is dependent on permanent disposable income and current deficits are equivalent to future tax payments. This hypothesis is tested on 14 European countries in the 1990s. The relationships between private sector savings and general government deficit, and the GDP growth rate and the unemployment rate are determined. The results show the change in consumers' behaviour with respect to government deficit, and that expectations of...

  11. Measured Stark widths and shifts of neutral silicon spectral lines

    International Nuclear Information System (INIS)

    Stark widths and shifts of five Si I line were measured at 28 500 K electron temperature and 1.9 x 1023 m-3 electron density in a linear, low-pressure, pulsed arc operated in argon-helium mixture. Our data are compared with values calculated on the basis of quasistatic approximation. (orig.)

  12. Measured Stark widths and shifts of neutral silicon spectral lines

    Energy Technology Data Exchange (ETDEWEB)

    Sreckovic, A.; Bukvic, S.; Djenize, S. [Belgrade Univ. (Yugoslavia). Faculty of Physics

    1998-02-01

    Stark widths and shifts of five Si I line were measured at 28 500 K electron temperature and 1.9 x 10{sup 23} m{sup -3} electron density in a linear, low-pressure, pulsed arc operated in argon-helium mixture. Our data are compared with values calculated on the basis of quasistatic approximation. (orig.). 9 refs.

  13. Surface width of the Solid-On-Solid models

    OpenAIRE

    Arisue, H.

    1997-01-01

    The low-temperature series for the surface width of the Absolute value Solid-On-Solid model and the Discrete Gaussian model both on the square lattice and on the triangular lattice are generated to high orders using the improved finite-lattice method. The series are analyzed to give the critical points of the roughening phase transition for each model.

  14. Measurement of two-photon widths of the ?2, ?', ?

    International Nuclear Information System (INIS)

    Results of a measurement of the two-photon widths of the ?2,?', ? mesons with the detector MD-1 at e+e-collider VEPP-4 are presented. The specific feature of this experiments is tagging of at least one scattered electron

  15. Widths of the atomic K-N7 levels

    CERN Document Server

    Campbell, J L

    2001-01-01

    Atomic level widths obtained from experimental measurements are collected in Table I, along with the corresponding theoretical widths derived from the Evaluated Atomic Data Library (EADL) of Lawrence Livermore National Laboratory; these EADL values are based upon the Dirac-Hartree-Slater version of the independent-particle model. In a minority of cases, many-body theory predictions are also provided. A brief discussion of the manner in which the experimental widths were deduced from spectroscopic data is included. The bulk of the data are for elements in the solid state, but a few data for gases and simple compounds are included. For the K, L2, L3, and M5 levels, where Coster-Kronig contributions do not contribute or contribute only to a small extent to the overall widths, the EADL predictions appear satisfactory for elements in the solid state. For other levels, where Coster-Kronig and super-Coster-Kronig transitions have large probabilities within the independent-particle model, this model is not satisfacto...

  16. Influence of nuclear structure on widths of ?-atomic terms

    International Nuclear Information System (INIS)

    The widths of 2p and 3d ?-atomic states in the nuclei 12C, 16O, 32S,40Ar,40-48Ca,46-50Ti and 52Cr assuming the 'two-nucleon' mechanism to be the doorway process for nuclear pion absorption. The results are in good agreement with experiment. (author)

  17. Improved determination of the width of the top quark

    Energy Technology Data Exchange (ETDEWEB)

    Abazov V. M.; Abbott B.; Acharya B. S.; Adams M.; Adams T.; Alexeev G. D.; Alkhazov G.; Alton A.; Alverson G.; Aoki M.; Askew A.; Asman B.; Atkins S.; Atramentov O.; Augsten K.; Avila C.; BackusMayes J.; Badaud F.; Bagby L.; Baldin B.; Bandurin D. V.; Banerjee S.; Barberis E.; Baringer P.; Barreto J.; Bartlett J. F.; Bassler U.; Bazterra V.; Bean A.; Begalli M.; Belanger-Champagne C.; Bellantoni L.; Beri S. B.; Bernardi G.; Bernhard R.; Bertram I.; Besancon M.; Beuselinck R.; Bezzubov V. A.; Bhat P. C.; Bhatia S.; Bhatnagar V.; Blazey G.; Blessing S.; Bloom K.; Boehnlein A.; Boline D.; Boos E. E.; Borissov G.; Bose T.; Brandt A.; Brandt O.; Brock R.; Brooijmans G.; Bross A.; Brown D.; Brown J.; Bu X. B.; Buehler M.; Buescher V.; Bunichev V.; Burdin S.; Burnett T. H.; Buszello C. P.; Calpas B.; Camacho-Perez E.; Carrasco-Lizarraga M. A.; Casey C. K.; Castilla-Valdez H.; Chakrabarti S.; Chakraborty D.; Chan M.; Chandra A.; Chapon E.; Chen G.; Chevalier-Thery S.; Cho D. K.; Cho S. W.; Choi S.; Choudhary B.; Cihangir S.; Claes D.; Clutter J.; Cooke M.; Cooper W. E.; Corcoran M.; Couderc F.; Cousinou M. -C.; Croc A.; Cutts D.; Das A.; Davies G.; de Jong S. J.; De La Cruz-Burelo E.; Deliot F.; Demina R.; Denisov D.; Denisov S. P.; Desai S.; Deterre C.; DeVaughan K.; Diehl H. T.; Diesburg M.; Ding P. F.; Dominguez A.; Dorland T.; Dubey A.; Dudko L. V.; Duggan D.; Duperrin A.; Dutt S.; Dyshkant A.; Eads M.; Edmunds D.; Ellison J.; Elvira V. D.; Enari Y.; Evans H.; Evdokimov A.; Evdokimov V. N.; Facini G.; Ferbel T.; Fiedler F.; Filthaut F.; Fisher W.; Fisk H. E.; Fortner M.; Fox H.; Fuess S.; Garcia-Bellido A.; Garcia-Guerra G. A.; Gavrilov V.; Gay P.; Geng W.; Gerbaudo D.; Gerber C. E.; Gershtein Y.; Ginther G.; Golovanov G.; Goussiou A.; Graf C. P.; Grannis P. D.; Greder S.; Greenlee H.; Greenwood Z. D.; Gregores E. M.; Grenier G.; Gris Ph.; Grivaz J. -F.; Grohsjean A.; Gruenendahl S.; Gruenewald M. W.; Guillemin T.; Gutierrez G.; Gutierrez P.; Haas A.; Hagopian S.; Haley J.; Han L.; Harder K.; Harel A.; Hauptman J. M.; Hays J.; Head T.; Hebbeker T.; Hedin D.; Hegab H.; Heinson A. P.; Heintz U.; Hensel C.; La Cruz I. Heredia-De; Herner K.; Hesketh G.; Hildreth M. D.; Hirosky R.; Hoang T.; Hobbs J. D.; Hoeneisen B.; Hohlfeld M.; Hubacek Z.; Hynek V.; Iashvili I.; Ilchenko Y.; Illingworth R.; Ito A. S.; Jabeen S.; Jaffre M.; Jamin D.; Jayasinghe A.; Jesik R.; Johns K.; Johnson M.; Jonckheere A.; Jonsson P.; Joshi J.; Jung A. W.; Juste A.; Kaadze K.; Kajfasz E.; Karmanov D.; Kasper P. A.; Katsanos I.; Kehoe R.; Kermiche S.; Khalatyan N.; Khanov A.; Kharchilava A.; Kharzheev Y. N.; Kohli J. M.; Kozelov A. V.; Kraus J.; Kulikov S.; Kumar A.; Kupco A.; Kurca T.; Kuzmin V. A.; Lammers S.; Landsberg G.; Lebrun P.; Lee H. S.; Lee S. W.; Lee W. M.; Lellouch J.; Li H.; Li L.; Li Q. Z.; Lietti S. M.; Lim J. K.; Lincoln D.; Linnemann J.; Lipaev V. V.; Lipton R.; Liu Y.; Lobodenko A.; Lokajicek M.; de Sa R. Lopes; Lubatti H. J.; Luna-Garcia R.; Lyon A. L.; Maciel A. K. A.; Mackin D.; Madar R.; Magana-Villalba R.; Malik S.; Malyshev V. L.; Maravin Y.; Martinez-Ortega J.; McCarthy R.; McGivern C. L.; Meijer M. M.; Melnitchouk A.; Menezes D.; Mercadante P. G.; Merkin M.; et al.

    2012-05-04

    We present an improved determination of the total width of the top quark, {Gamma}{sub t}, using 5.4 fb{sup -1} of integrated luminosity collected by the D0 Collaboration at the Tevatron p{bar p} Collider. The total width {Gamma}{sub t} is extracted from the partial decay width {Gamma}(t {yields} Wb) and the branching fraction {Beta}(t {yields} Wb). {Gamma}(t {yields} Wb) is obtained from the t-channel single top-quark production cross section and {Beta}(t {yields} Wb) is measured in t{bar t} events. For a top mass of 172.5 GeV, the resulting width is {Gamma}{sub t} = 2.00{sub -0.43}{sup +0.47} GeV. This translates to a top-quark lifetime of {tau}{sub t} = (3.29{sub -0.63}{sup +0.90}) x 10{sup -25} s. We also extract an improved direct limit on the Cabibbo-Kobayashi-Maskawa quark-mixing matrix element 0.81 < |V{sub tb}| {le} 1 at 95% C.L. and a limit of |V{sub tb}| < 0.59 for a high-mass fourth-generation bottom quark assuming unitarity of the fourth-generation quark-mixing matrix.

  18. Sinusoidal and Space Vector Pulse Width Modulation for Inverter

    Directory of Open Access Journals (Sweden)

    K. Mounika#1 , B. Kiran Babu

    2013-04-01

    Full Text Available Inverters inherently have the property of controlling output frequency but the output voltage can’t be varied. Usually to vary output voltage we have to vary supply voltage which is not always possible for this reason PWM techniques gained momentum. Basic aim of PWM technique is to control output voltage and harmonic reduction. Pulse-width modulation (PWM, or pulseduration modulation (PDM, is a commonly used technique for controlling power to inertial electrical devices, made practical by modern electronic power switches. Here we apply PWM techniques like Sinusoidal pulse width modulation (SPWM and Space Vector Pulse width Modulation (SVPWM to inverter and study its performance. In Sinusoidal Pulse width modulation (SPWM we generate the gating signals by comparing a sinusoidal reference signal with a triangular carrier wave. In Space vector Modulation (SVPWM we consider a rotating phased which is obtained by adding all the three voltages. Modulation is accomplished by switching state of an inverter. Thus by comparing these two techniques we study the performance of our inverter.

  19. An Improved determination of the width of the top quark

    Energy Technology Data Exchange (ETDEWEB)

    Abazov, Victor Mukhamedovich; /Dubna, JINR; Abbott, Braden Keim; /Oklahoma U.; Acharya, Bannanje Sripath; /Tata Inst.; Adams, Mark Raymond; /Illinois U., Chicago; Adams, Todd; /Florida State U.; Alexeev, Guennadi D.; /Dubna, JINR; Alkhazov, Georgiy D.; /St. Petersburg, INP; Alton, Andrew K.; /Michigan U. /Augustana Coll., Sioux Falls; Alverson, George O.; /Northeastern U.; Aoki, Masato; /Fermilab; Askew, Andrew Warren; /Florida State U. /Stockholm U.

    2012-01-01

    We present an improved determination of the total width of the top quark, {Lambda}{sub t}, using 5.4 fb{sup -1} of integrated luminosity collected by the D0 Collaboration at the Tevatron p{bar p} Collider. The total width {Lambda}{sub t} is extracted from the partial decay width {Lambda}(t {yields} Wb) and the branching fraction {Beta}(t {yields} Wb). {Lambda}(t {yields} Wb) is obtained from the t-channel single top quark production cross section and {Beta}(t {yields} Wb) is measured in t{bar t} events. For a top mass of 172.5 GeV, the resulting width is {Lambda}{sub t} = 2.00{sub -0.43}{sup +0.47} GeV. This translates to a top-quark lifetime of {tau}{sub t} = (3.29{sub -0.63}{sup +0.90}) x 10{sup -25} s. We also extract an improved direct limit on the CKM matrix element 0.81 < |V{sub tb}| {le} 1 at 95% C.L. and a limit of |V{sub tb'}| < 0.59 for a high mass fourth generation bottom quark assuming unitarity of the fourth generation quark mixing matrix.

  20. Scaling of divertor power footprint width in RF-heated type-III ELMy H-mode on the EAST superconducting tokamak

    International Nuclear Information System (INIS)

    Dedicated experiments for the scaling of divertor power footprint width have been performed in the ITER-relevant radio-frequency (RF)-heated H-mode scheme under the lower single null, double null and upper single null divertor configurations in the Experimental Advanced Superconducting Tokamak (EAST) under lithium wall coating conditioning. A strong inverse scaling of the edge localized mode (ELM)-averaged power fall-off width with the plasma current (equivalently the poloidal field) has been demonstrated for the attached type-III ELMy H-mode as ?q?Ip?1.05 by various heat flux diagnostics including the divertor Langmuir probes (LPs), infra-red (IR) thermograph and reciprocating LPs on the low-field side. The IR camera and divertor LP measurements show that ?q,IR??q,div-LPs/1.3=1.15Bp,omp?1.25, in good agreement with the multi-machine scaling trend during the inter-ELM phase between type-I ELMs or ELM-free enhanced D? (EDA). H-mode. However, the magnitude is nearly doubled, which may be attributed to the different operation scenarios or heating schemes in EAST, i.e., dominated by electron heating. It is also shown that the type-III ELMs only broaden the power fall-off width slightly, and the ELM-averaged width is representative for the inter-ELM period. Furthermore, the inverse Ip (Bp) scaling appears to be independent of the divertor configurations in EAST. The divertor power footprint integral width, fall-off width and dissipation width derived from EAST IR camera measurements follow the relation, ?int ? ?q + 1.64S, yielding ?intEAST=(1.39±0.03)?qEAST+(0.97±0.35) mm. Detailed analysis of these three characteristic widths was carried out to shed more light on their extrapolation to ITER. (paper)

  1. Scaling of divertor power footprint width in RF-heated type-III ELMy H-mode on the EAST superconducting tokamak

    Science.gov (United States)

    Wang, L.; Guo, H. Y.; Xu, G. S.; Liu, S. C.; Gan, K. F.; Wang, H. Q.; Gong, X. Z.; Liang, Y.; Zou, X. L.; Hu, J. S.; Chen, L.; Xu, J. C.; Liu, J. B.; Yan, N.; Zhang, W.; Chen, R.; Shao, L. M.; Ding, S.; Hu, G. H.; Feng, W.; Zhao, N.; Xiang, L. Y.; Liu, Y. L.; Li, Y. L.; Sang, C. F.; Sun, J. Z.; Wang, D. Z.; Ding, H. B.; Luo, G. N.; Chen, J. L.; Gao, X.; Hu, L. Q.; Wan, B. N.; Li, J.; the EAST Team

    2014-11-01

    Dedicated experiments for the scaling of divertor power footprint width have been performed in the ITER-relevant radio-frequency (RF)-heated H-mode scheme under the lower single null, double null and upper single null divertor configurations in the Experimental Advanced Superconducting Tokamak (EAST) under lithium wall coating conditioning. A strong inverse scaling of the edge localized mode (ELM)-averaged power fall-off width with the plasma current (equivalently the poloidal field) has been demonstrated for the attached type-III ELMy H-mode as ?q \\propto Ip-1.05 by various heat flux diagnostics including the divertor Langmuir probes (LPs), infra-red (IR) thermograph and reciprocating LPs on the low-field side. The IR camera and divertor LP measurements show that ?q,IR ? {?q,div{-LPs}}/{1.3}=1.15Bp,omp-1.25 , in good agreement with the multi-machine scaling trend during the inter-ELM phase between type-I ELMs or ELM-free enhanced D? (EDA). H-mode. However, the magnitude is nearly doubled, which may be attributed to the different operation scenarios or heating schemes in EAST, i.e., dominated by electron heating. It is also shown that the type-III ELMs only broaden the power fall-off width slightly, and the ELM-averaged width is representative for the inter-ELM period. Furthermore, the inverse Ip (Bp) scaling appears to be independent of the divertor configurations in EAST. The divertor power footprint integral width, fall-off width and dissipation width derived from EAST IR camera measurements follow the relation, ?int ? ?q + 1.64S, yielding ?_intEAST =(1.39+/- 0.03)?qEAST +(0.97+/- 0.35) mm . Detailed analysis of these three characteristic widths was carried out to shed more light on their extrapolation to ITER.

  2. DUST EXTINCTION FROM BALMER DECREMENTS OF STAR-FORMING GALAXIES AT 0.75 {<=} z {<=} 1.5 WITH HUBBLE SPACE TELESCOPE/WIDE-FIELD-CAMERA 3 SPECTROSCOPY FROM THE WFC3 INFRARED SPECTROSCOPIC PARALLEL SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez, A.; Siana, B.; Masters, D. [Department of Physics and Astronomy, University of California Riverside, Riverside, CA 92521 (United States); Henry, A. L.; Martin, C. L. [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Scarlata, C.; Bedregal, A. G. [Minnesota Institute for Astrophysics, University of Minnesota, Minneapolis, MN 55455 (United States); Malkan, M.; Ross, N. R. [Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, CA 90095 (United States); Atek, H.; Colbert, J. W. [Spitzer Science Center, Caltech, Pasadena, CA 91125 (United States); Teplitz, H. I.; Rafelski, M. [Infrared Processing and Analysis Center, Caltech, Pasadena, CA 91125 (United States); McCarthy, P.; Hathi, N. P.; Dressler, A. [Observatories of the Carnegie Institution for Science, Pasadena, CA 91101 (United States); Bunker, A., E-mail: albertod@ucr.edu [Department of Physics, Oxford University, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom)

    2013-02-15

    Spectroscopic observations of H{alpha} and H{beta} emission lines of 128 star-forming galaxies in the redshift range 0.75 {<=} z {<=} 1.5 are presented. These data were taken with slitless spectroscopy using the G102 and G141 grisms of the Wide-Field-Camera 3 (WFC3) on board the Hubble Space Telescope as part of the WFC3 Infrared Spectroscopic Parallel survey. Interstellar dust extinction is measured from stacked spectra that cover the Balmer decrement (H{alpha}/H{beta}). We present dust extinction as a function of H{alpha} luminosity (down to 3 Multiplication-Sign 10{sup 41} erg s{sup -1}), galaxy stellar mass (reaching 4 Multiplication-Sign 10{sup 8} M {sub Sun }), and rest-frame H{alpha} equivalent width. The faintest galaxies are two times fainter in H{alpha} luminosity than galaxies previously studied at z {approx} 1.5. An evolution is observed where galaxies of the same H{alpha} luminosity have lower extinction at higher redshifts, whereas no evolution is found within our error bars with stellar mass. The lower H{alpha} luminosity galaxies in our sample are found to be consistent with no dust extinction. We find an anti-correlation of the [O III] {lambda}5007/H{alpha} flux ratio as a function of luminosity where galaxies with L {sub H{alpha}} < 5 Multiplication-Sign 10{sup 41} erg s{sup -1} are brighter in [O III] {lambda}5007 than H{alpha}. This trend is evident even after extinction correction, suggesting that the increased [O III] {lambda}5007/H{alpha} ratio in low-luminosity galaxies is likely due to lower metallicity and/or higher ionization parameters.

  3. a Linear Model for Meandering Rivers with Arbitrarily Varying Width

    Science.gov (United States)

    Frascati, A.; Lanzoni, S.

    2011-12-01

    Alluvial rivers usually exhibit quite complex planforms, characterized by a wide variety of alternating bends, that have attracted the interest of a large number of researchers. Much less attention has been paid to another striking feature observed in alluvial rivers, namely the relatively regular spatial variations attained by the channel width. Actively meandering channels, in fact, generally undergo spatial oscillations systematically correlated with channel curvature, with cross sections wider at bends than at crossings. Some other streams have been observed to exhibit irregular width variations. Conversely, rivers flowing in highly vegetated flood plains, i.e. canaliform rivers, may exhibit an opposite behavior, owing to the combined effects of bank erodibility and floodplain depositional processes which, in turn, are strictly linked to vegetation cover. Similarly to streamline curvatures induced by bends, the presence of along channel width variations may have remarkable effects on the flow field and sediment dynamics and, thereby, on the equilibrium river bed configuration. In particular, spatial distribution of channel curvature typically determines the formation of a rhythmic bar-pool pattern in the channel bed strictly associated with the development of river meanders. Channel width variations are on the contrary characterized by a sequence of narrowing, yielding a central scour, alternated to the downstream development of a widening associated with the formation of a central bar. Here we present a morphodynamic model that predict at a linear level the spatial distribution of the flow field and the equilibrium bed configuration of an alluvial river characterized by arbitrary along channel distributions of both the channel axis curvature and the channel width. The mathematical model is averaged over the depth and describes the steady, non-uniform flow and sediment transport in sinuous channels with a noncohesive bed. The governing two-dimensional equations are derived by depth-averaging the three-dimensional conservation equations and accounting for the dynamic effects of secondary flows. A two-parameter perturbation expansion technique, considering perturbations induced by curvature and spatial channel width variations, is adopted to linearize the governing equations. The model predictions are then tested by a direct application to a test case. We show that the present model provides a further step towards the development of a computationally sustainable and robust framework to simulate the long term evolution of alluvial rivers.

  4. Quantum mechanics and the equivalence principle

    International Nuclear Information System (INIS)

    A quantum particle moving in a gravitational field may penetrate the classically forbidden region of the gravitational potential. This raises the question of whether the time of flight of a quantum particle in a gravitational field might deviate systematically from that of a classical particle due to tunnelling delay, representing a violation of the weak equivalence principle. I investigate this using a model quantum clock to measure the time of flight of a quantum particle in a uniform gravitational field, and show that a violation of the equivalence principle does not occur when the measurement is made far from the turning point of the classical trajectory. The results are then confirmed using the so-called dwell time definition of quantum tunnelling. I conclude with some remarks about the strong equivalence principle in quantum mechanics

  5. Equivalent magnetization over the World Ocean

    Science.gov (United States)

    Dyment, J.; Hamoudi, M.; Choi, Y.; Thebault, E.; Quesnel, Y.; Roest, W. R.; Lesur, V.

    2012-12-01

    In another presentation (Hamoudi et al., this meeting), we present the construction of a new candidate for the World Digital Magnetic Anomaly Map (WDMAM) over oceanic areas. This map is based on: (a) a more realistic forward modeling of the marine magnetic anomalies which includes remanent magnetization vectors taking into account the age and motion of the oceanic lithosphere; (b) evaluation of the equivalent magnetization by comparison of the synthetic and observed anomalies along ship tracks; and (c) adjustment of the synthetic anomaly maps using this equivalent magnetization prior to merging with the observed anomalies. A by-product of this approach is a global distribution of equivalent magnetization over the World's Ocean. Note that, because no global basement map exists for the oceanic areas, we assume a uniform, 5 km-deep and 1 km-thick magnetized layer for the forward model. The resulting equivalent magnetization is therefore relative to this over-simplistic magnetic source. A first observation is that, within the hypotheses of the forward model, the average equivalent magnetization is about 3 A/m, a value which compares well with the Natural Remanent Magnetization (NRM) measured on ancient basalt samples. As expected, the mid-ocean ridges are marked by stronger equivalent magnetizations, an observation which reflects both the stronger NRM measured at ridge axes and their shallower bathymetry (not taken into account in our forward model). More interesting is the observation of significant along-axis variations. In the North Atlantic Ocean, the Kolbeinsey and Reykjanes ridges around Iceland are marked by a very strong equivalent magnetization and the Azores Plateau by a strong one as well.. Again this may reflect the combined effect of shallower seafloor, thicker and/or more magnetized basaltic layer at hotspots. In contrast, the areas between 45 and 55°N and between 0 and 10°N (Equatorial FZ) correspond to a weak equivalent magnetization. Further south, the Mid-Atlantic Ridge displays a more uniform signature, although off-axis variations seem associated to the Tristan and St Helena hotspots. In the Indian Ocean, a strong equivalent magnetization characterizes areas of hotspot-ridge interaction such as the Gulf of Aden, the Central Indian Ridge near Rodrigues Island, the Southwest Indian Ridge near Marion Island, and the Southeast Indian Ridge near St Paul and Amsterdam Islands. A weaker one is observed in colder area, at the Australian-Antarctic Discordance and around the Rodrigues Triple Junction. The Pacific Ocean is characterized by a generally stronger equivalent magnetization, both near ridges and in abyssal plains. Time variations, i.e. along seafloor spreading flowlines, are apparent across the Mid-Atlantic and Pacific-Antarctic ridges, with highs near the ridge axis (younger than 10 Ma) and between ~83 and 60 Ma, just after the Cretaceous Normal Superchron and lows between ~60 and 10 Ma. The Mesozoic basins of the Pacific and Atlantic oceans show a weaker equivalent magnetization before ~155 Ma and a stronger one after. Basins covered by thick sediments such as the Bengal Bay, Great Australian Bight, Nova Scotia Basin, and Western Somali Basin show a very weak equivalent magnetization, reflecting both a deeper basement and a possible thermal demagnetization. Some of these variations coincide with satellite magnetic anomalies.

  6. Visual masking by translation equivalents in bilinguals.

    Science.gov (United States)

    O'Neill, W

    1977-12-01

    Masking thresholds for common words as a function of the relationship between target and mask were assessed using French-English bilingual subjects. Five target-mask combinations were employed. Two control conditions involved unrelated pairs presented in either the same or both languages. The experimental conditions employed masks that were subordinate to the target, e.g., animal-horse, masks that were thr translation equivalents of the targets, and masks which were homophones of the target. Homophones were superior masks compared to same-language, unrelated masks which were in turn superior to subordinately related masks. Translation equivalents were less effective masks than different-language, unrelated masks but were similar to subordinate same-language masks. The results suggest that the relationship between the representations of translation equivalents is similar to that between same-language superordinate and subordinate words. PMID:604918

  7. Bisimulations Meet PCTL Equivalences for Probabilistic Automata

    DEFF Research Database (Denmark)

    Song, Lei; Zhang, Lijun

    2011-01-01

    Probabilistic automata (PA) have beensuccessfully applied in the formal verification of concurrent andstochastic systems. Efficient model checking algorithms have beenstudied, where the most often used logics for expressing propertiesare based on PCTL and its extensionPCTL*. Variousbehavioral equivalences are proposed for PAs, asa powerful tool for abstraction and compositional minimization forPAs. Unfortunately, the behavioral equivalencesare well-known to be strictly stronger than the logical equivalences inducedby PCTL or PCTL*. This paper introduces novel notions of strongbisimulation relations, which characterizes PCTL and PCTL*exactly. We also extend weak bisimulations characterizingPCTL and PCTL* without next operator, respectively. Thus, ourpaper bridges the gap between logical and behavioral equivalences inthis setting.

  8. Nondeterministic automata: equivalence, bisimulations, and uniform relations

    CERN Document Server

    ?iri?, Miroslav; Baši?, Milan; Jan?i?, Ivana

    2011-01-01

    In this paper we study the equivalence of nondeterministic automata pairing the concept of a bisimulation with the recently introduced concept of a uniform relation. In this symbiosis, uniform relations serve as equivalence relations which relate states of two possibly different nondeterministic automata, and bisimulations ensure compatibility with the transitions, initial and terminal states of these automata. We define six types of bisimulations, but due to the duality we discuss three of them: forward, backward-forward, and weak forward bisimulations. For each od these three types of bisimulations we provide a procedure which decides whether there is a bisimulation of this type between two automata, and when it exists, the same procedure computes the greatest one. We also show that there is a uniform forward bisimulation between two automata if and only if the factor automata with respect to the greatest forward bisimulation equivalences on these automata are isomorphic. We prove a similar theorem for weak...

  9. Equivalent circuit model of radiative heat transfer

    CERN Document Server

    Maslovski, Stanislav I; Tretyakov, Sergei A

    2012-01-01

    Here, we develop a theory of radiative heat transfer based on an equivalent electrical network representation for the hot material slabs in an arbitrary multilayered environment with arbitrary distribution of temperatures and electromagnetic properties among the layers. Our approach is fully equivalent to the known theories operating with the fluctuating current density, while being significantly simpler in analysis and applications. A practical example of the near-infrared heat transfer through the micron gap filled with an indefinite metmaterial is considered using the suggested method. The giant enhancement of the transferred heat compared to the case of the empty gap is shown.

  10. Fiscal adjustments in Europe and Ricardian equivalence

    Directory of Open Access Journals (Sweden)

    V. DE BONIS

    1998-09-01

    Full Text Available According to the ‘Ricardian’ equivalence hypothesis, consumption is dependent on permanent disposable income and current deficits are equivalent to future tax payments. This hypothesis is tested on 14 European countries in the 1990s. The relationships between private sector savings and general government deficit, and the GDP growth rate and the unemployment rate are determined. The results show the change in consumers' behaviour with respect to government deficit, and that expectations of an increase in future wealth are no longer associated with a decrease in deficit.

  11. Direct Top-Quark Width Measurement at CDF

    International Nuclear Information System (INIS)

    We present a measurement of the top-quark width in the lepton+jets decay channel of tt events produced in pp collisions at Fermilab's Tevatron collider and collected by the CDF II detector. From a data sample corresponding to 4.3 fb-1 of integrated luminosity, we identify 756 candidate events. The top-quark mass and the mass of the hadronically decaying W boson that comes from the top-quark decay are reconstructed for each event and compared with templates of different top-quark widths (?t) and deviations from nominal jet energy scale (?JES) to perform a simultaneous fit for both parameters, where ?JES is used for the in situ calibration of the jet energy scale. By applying a Feldman-Cousins approach, we establish an upper limit at 95% confidence level (CL) of ?tt2, which are consistent with the standard model prediction.

  12. The complexity of the fermionant, and immanants of constant width

    CERN Document Server

    Mertens, Stephan

    2011-01-01

    In the context of statistical physics, Chandrasekharan and Wiese recently introduced the \\emph{fermionant} $\\Ferm_k$, a determinant-like quantity where each permutation $\\pi$ is weighted by $-k$ raised to the number of cycles in $\\pi$. We show that computing $\\Ferm_k$ is #P-hard under Turing reductions for any constant $k > 2$, and is $\\oplusP$-hard for $k=2$, even for the adjacency matrices of planar graphs. As a consequence, unless the polynomial hierarchy collapses, it is impossible to compute the immanant $\\Imm_\\lambda \\,A$ as a function of the Young diagram $\\lambda$ in polynomial time, even if the width of $\\lambda$ is restricted to be at most 2. In particular, if $\\Ferm_2$ is in P, or if $\\Imm_\\lambda$ is in P for all $\\lambda$ of width 2, then $\\NP \\subseteq \\RP$ and there are randomized polynomial-time algorithms for NP-complete problems.

  13. Determination of the width of the top quark

    CERN Document Server

    Abazov, V M; Abolins, M; Acharya, B S; Adams, M; Adams, T; Alexeev, G D; Alkhazov, G; Altona, A; Alverson, G; Alves, G A; Ancu, L S; Aoki, M; Arnoud, Y; Arov, M; Askew, A; \\degAsman, B; Atramentov, O; Avila, C; BackusMayes, J; Badaud, F; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, S; Barberis, E; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bazterra, V; Beale, S; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besan?con, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Blazey, G; Blessing, S; Bloom, K; Boehnlein, A; Boline, D; Bolton, T A; Boos, E E; Borissov, G; Bose, T; Brandt, A; Brandt, O; Brock, R; Brooijmans, G; Bross, A; Brown, D; Brown, J; Bu, X B; Buchholz, D; Buehler, M; Buescher, V; Bunichev, V; Burdinb, S; Burnett, T H; Buszello, C P; Calpas, B; Camacho-P?erez, E; Carrasco-Lizarraga, M A; Casey, B C K; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chandra, A; Chen, G; Chevalier-Th?ery, S; Cho, D K; Cho, S W; Choi, S; Choudhary, B; Christoudias, T; Cihangir, S; Claes, D; Clutter, J; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M -C; Croc, A; Cutts, D; ?Cwiok, M; Das, A; Davies, G; De, K; de Jong, S J; De La Cruz-Burelo, E; D?eliot, F; Demarteau, M; Demina, 47 R; Denisov, D; Denisov, S P; Desai, S; DeVaughan, K; Diehl, H T; Diesburg, M; Dominguez, A; Dorland, T; Dubey, A; Dudko, L V; Duggan, D; Duperrin, A; Dutt, S; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Eno, S; Evans, H; Evdokimov, A; Evdokimov, V N; Facini, G; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fortner, M; Fox, H; Fuess, S; Gadfort, T; Garcia-Bellido, A; Gavrilov, V; Gay, P; Geist, W; Geng, W; Gerbaudo, D; Gerber, C E; Gershtein, Y; Ginther, G; Golovanov, G; Goussiou, A; Grannis, P D; Greder, S; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, Ph; Grivaz, J -F; Grohsjean, A; Gr?unendahl, S; Gr?unewald, M W; Guo, F; Guo, J; Gutierrez, G; Gutierrez, P; Haasc, A; Hagopian, S; Haley, J; Han, L; Harder, K; Harel, A; Hauptman, J M; Hays, J; Head, T; Hebbeker, T; Hedin, D; Hegab, H; Heinson, A P; Heintz, U; Hensel, C; La Cruz, I Heredia-De; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hoang, T; Hobbs, J D; Hoeneisen, B; Hohlfeld, M; Hossain, S; Hubacek, Z; Huske, N; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffr?e, M; Jain, S; Jamin, D; Jesik, R; Johns, K; Johnson, M; Johnston, D; Jonckheere, A; Jonsson, P; Joshi, J; Justed, A; Kaadze, K; Kajfasz, E; Karmanov, D; Kasper, P A; Katsanos, I; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Y N; Khatidze, D; Kirby, M H; Kohli, J M; Kozelov, A V; Kraus, J; Kumar, A; Kupco, A; Kur?ca, T; Kuzmin, V A; Kvita, J; Lammers, S; Landsberg, G; Lebrun, P; Lee, H S; Lee, S W; Lee, W M; Lellouch, J; Li, L; Li, Q Z; Lietti, S M; Lim, J K; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Y; Liu, Z; Lobodenko, A; Lokajicek, M; Love, P; Lubatti, H J; Luna-Garciae, R; Lyon, A L; Maciel, A K A; Mackin, D; Madar, R; Maga?na-Villalba, R; Malik, S; Malyshev, V L; Maravin, Y; Mart?\\inez-Ortega, J; McCarthy, R; McGivern, C L; Meijer, M M; Melnitchouk, A; Menezes, D; Mercadante, P G; Merkin, M; Meyer, A; Meyer, J; Mondal, N K; Muanza, G S; Mulhearn, M; Nagy, E; Naimuddin, M; Narain, M; Nayyar, R; Neal, H A; Negret, J P; Neustroev, P; Novaes, S F; Nunnemann, T; Obrant, G; Orduna, J; Osman, N; Osta, J; Garz?on, G J Otero y; Owen, 1 M; Padilla, M; Pangilinan, M; Parashar, N; Parihar, V; Park, S K; Parsons, J; Partridgec, R; Parua, N; Patwa, A; Penning, B; Perfilov, M; Peters, K; Peters, Y; Petrillo, G; P?etroff, P; Piegaia, R; Piper, J; Pleier, M -A; Podesta-Lermaf, P L M; Podstavkov, V M; Pol, M -E; Polozov, P; Popov, A V; Prewitt, M; Price, D; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rangel, M S; Ranjan, K; Ratoff, P N; Razumov, I; Renkel, P; Rich, P; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Rominsky, M; Royon, C; Rubinov, P; Ruchti, R; Safronov, G; Sajot, G; S?anchez-Hern?andez, A; Sanders, M P; Sanghi, B; Santos, A S; Savage, G; Sawyer, L; Scanlon, T; Schamberger, R D; Scheglov, Y; Schellman, H; Schliephake, T; Schlobohm, S; Schwanenberger, C; Schwienhorst, R; Sekaric, J; Severini, H; Shabalina, E; Shary, V; Shchukin, A A; Shivpuri, R K; Simak, V; Sirotenko, V; Skubic, P; Slattery, P; Smirnov, D; Smith, K J; Snow, G R; Snow, J; Snyder, S; S?oldner-Rembold, S; Sonnenschein, L; Sopczak, A; Sosebee, M; Soustruznik, K; Spurlock, B; Stark, J; Stolin, V; Stoyanova, D A; Strauss, E; Strauss, M; Strom, D; Stutte, L; Svoisky, P; Takahashi, M; Tanasijczuk, A; Taylor, W; Titov, M; Tokmenin, V V; Tsybychev, D; Tuchming, B; Tully, C; Tuts, P M; Uvarov, L; Uzunyan, S Uvarov S; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vasilyev, I A; Verdier, P

    2010-01-01

    We extract the total width of the top quark, Gamma_t, from the partial decay width Gamma(t -> W b) measured using the t-channel cross section for single top quark production and from the branching fraction B(t -> W b) measured in ttbar events using up to 2.3 fb^-1 of integrated luminosity collected by the D0 Collaboration at the Tevatron ppbar Collider. The result is Gamma_t = 1.99 +0.69 -0.55 GeV, which translates to a top-quark lifetime of tau_t = (3.3 +1.3 -0.9) x 10^-25 s. Assuming a high mass fourth generation b' quark and unitarity of the four-generation quark-mixing matrix, we set the first upper limit on |Vtb'| < 0.63 at 95% C.L.

  14. A Direct Measurement of the $W$ Decay Width

    Energy Technology Data Exchange (ETDEWEB)

    Vine, Troy; /University Coll. London

    2008-08-01

    A direct measurement of the W boson total decay width is presented in proton-antiproton collisions at {radical}s = 1.96 TeV using data collected by the CDF II detector. The measurement is made by fitting a simulated signal to the tail of the transverse mass distribution in the electron and muon decay channels. An integrated luminosity of 350 pb{sup -1} is used, collected between February 2002 and August 2004. Combining the results from the separate decay channels gives the decay width as 2.038 {+-} 0.072 GeV in agreement with the theoretical prediction of 2.093 {+-} 0.002 GeV. A system is presented for the management of detector calibrations using a relational database schema. A description of the implementation and monitoring of a procedure to provide general users with a simple interface to the complete set of calibrations is also given.

  15. The excision width in surgical treatment of basal cell carcinoma

    Directory of Open Access Journals (Sweden)

    Mališ M.

    2006-01-01

    Full Text Available Basal cell carcinoma originates from pluripotent cells of basal layer of epiderm, external covering of hair follicles, sebaceous glands or other skin adnexa. It is characterized by local infiltrating and sometimes destructive growth. There are several types of basal cell carcinomas that may be manifested in over 12 clinical forms. Surgical treatment depends to a large extent on the histological type, localization and its clinical manifestation. The analysis included 250 patients of both gender and different age, operated for basal cell carcinoma. Clinical characteristics of basal cell carcinoma and the width of the excision were described. It was concluded that the width of the excision of basal cell cancer was in relation to histological type. .

  16. Equivalent circuit model of an ultra-thin polarization-independent triple band metamaterial absorber

    Science.gov (United States)

    Bhattacharyya, Somak; Ghosh, Saptarshi; Srivastava, Kumar Vaibhav

    2014-09-01

    This paper presents equivalent circuit modeling of an ultra-thin polarization-independent metamaterial microwave absorber consisting of three concentric closed ring resonators (CRR). The unit cell size as well as the other geometrical dimensions like radii and widths of the rings are optimized so that absorptions take place at three distinct frequencies near to the middle of the FCC defined radar spectrum eg., at 5.50 GHz, 9.52 GHz and 13.80 GHz with peak absorptivities of 94.1%, 99.6% and 99.4% respectively. The equivalent circuit model of the triple band absorber has been developed sequentially considering the single band and double band absorber models. The circuit simulation of the final model agrees well with the full-wave simulation, thus validating the modeling technique. The structure is also fabricated and experimental absorption peaks are found close to the simulated values.

  17. The Width of Galton- Watson Trees Conditioned by the Size

    OpenAIRE

    Michael Drmota; Bernhard Gittenberger

    2004-01-01

    It is proved that the moments of the width of Galton-Watson trees of size n and with offspring variance ? 2 are asymptotically given by (?? n) p m p where m p are the moments of the maximum of the local time of a standard scaled Brownian excursion. This is done by combining a weak limit theorem and a tightness estimate. The method is quite general and we state some further applications.

  18. Verbal subgroups of hyperbolic groups have infinite width

    OpenAIRE

    Myasnikov, Alexei; Nikolaev, Andrey

    2011-01-01

    Let $G$ be a non-elementary hyperbolic group. Let $w$ be a group word such that the set $w[G]$ of all its values in $G$ does not coincide with $G$ or 1. We show that the width of verbal subgroup $w(G)=$ is infinite. That is, there is no such $l\\in\\mathbb Z$ that any $g\\in w(G)$ can be represented as a product of $\\le l$ values of $w$ and their inverses.

  19. Mesiodistal width and proximal enamel thickness of maxillary first bicuspids

    OpenAIRE

    Aurélio de Carvalho Macha; Flávio Vellini-Ferreira; Helio Scavone-Junior; Rívea Inês Ferreira

    2010-01-01

    This study aimed at evaluating measurements relative to the mesiodistal crown width and enamel thickness of maxillary first bicuspids. The sample consisted of 40 extracted sound bicuspids (20 right and 20 left), selected from white patients (mean age: 23.7 ± 4.2 years), who were treated orthodontically with tooth extraction at a private clinic in São Paulo, SP, Brazil. All teeth were embedded in acrylic resin and cut along their long axis through the proximal surfaces, parallel to the bucca...

  20. Sinusoidal and Space Vector Pulse Width Modulation for Inverter

    OpenAIRE

    K Mounika, B. Kiran Babu

    2013-01-01

    Inverters inherently have the property of controlling output frequency but the output voltage can’t be varied. Usually to vary output voltage we have to vary supply voltage which is not always possible for this reason PWM techniques gained momentum. Basic aim of PWM technique is to control output voltage and harmonic reduction. Pulse-width modulation (PWM), or pulseduration modulation (PDM), is a commonly used technique for controlling power to inertial electrical devices, made practical by...