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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

    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. H I Lyman-alpha Equivalent Widths of Stellar Populations

    Peña-Guerrero, María A.; Leitherer, Claus

    2013-12-01

    We have compiled a library of stellar Lyman-alpha (Lyα) equivalent widths in O and B stars using the model atmosphere codes CMFGEN and TLUSTY, respectively. The equivalent widths range from about 0 to 30 Å in absorption for early-O to mid-B stars. The purpose of this library is for the prediction of the underlying stellar Lyα absorption in stellar populations of star-forming galaxies with nebular Lyα emission. We implemented the grid of individual equivalent widths into the Starburst99 population synthesis code to generate synthetic Lyα equivalent widths for representative star formation histories. A starburst observed after 10 Myr will produce a stellar Lyα line with an equivalent width of ~ - 10 ± 4 Å in absorption for a Salpeter initial mass function. The lower value (deeper absorption) results from an instantaneous burst, and the higher value (shallower line) from continuous star formation. Depending on the escape fraction of nebular Lyα photons, the effect of stellar Lyα on the total profile ranges from negligible to dominant. If the nebular escape fraction is 10%, the stellar absorption and nebular emission equivalent widths become comparable for continuous star formation at ages of 10-20 Myr.

  3. HI Lyman-alpha equivalent widths of stellar populations

    Pena-Guerrero, Maria A

    2013-01-01

    We have compiled a library of stellar Lyman-alpha equivalent widths in O and B stars using the model atmosphere codes CMFGEN and TLUSTY, respectively. The equivalent widths range from about 0 to 30 \\AA in absorption for early-O to mid-B stars. The purpose of this library is the prediction of the underlying stellar Lyman-alpha absorption in stellar populations of star-forming galaxies with nebular Lyman-alpha emission. We implemented the grid of individual equivalent widths into the Starburst99 population synthesis code to generate synthetic Lyman-alpha equivalent widths for representative star-formation histories. A starburst observed after 10 Myr will produce a stellar Lyman-alpha line with an equivalent width of $\\sim$ -10$\\pm$4 \\AA in absorption for a Salpeter initial mass function. The lower value (deeper absorption) results for an instantaneous burst, and the higher value (shallower line) for continuous star formation. Depending on the escape fraction of nebular Lyman-alpha photons, the effect of stellar...

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

    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...

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

    de Ugarte Postigo, A.; Fynbo, J. P. U.; Thöne, C. C.; Christensen, L.; Gorosabel, J.; Milvang-Jensen, B.; Schulze, S.; Jakobsson, P.; Wiersema, K.; Sánchez-Ramírez, R.; Leloudas, G.; Zafar, T.; Malesani, D.; Hjorth, J.

    2012-12-01

    Context. 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 at almost any redshift. Aims: We describe the distribution of rest-frame equivalent widths (EWs) of the most prominent absorption features in GRB afterglow spectra, providing the means to compare individual spectra to the sample and identify its peculiarities. Methods: Using 69 low-resolution GRB afterglow spectra, we conduct a study of the rest-frame EWs distribution of features with an average rest-frame EW larger than 0.5 Å. 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 in a GRB spectrum as compared to the sample by a single number. Using the distributions of EWs of single-species features, we derive the distribution of their column densities by a curve of growth (CoG) fit. Results: 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 the LSP with the redshift. There is a weak correlation between the ionisation of the absorbers and the energy of the GRB, indicating that, either the GRB event is responsible for part of the ionisation, or that galaxies with high-ionisation media produce more energetic GRBs. Spectral features in GRB spectra are, on average, 2.5 times stronger than those seen in QSO intervening damped Lyman-α (DLA) systems and slightly more ionised. In particular we find a larger excess in the EW of C ivλλ1549 relative to QSO DLAs, which could be related to an excess of Wolf-Rayet stars in the environments of GRBs. From the CoG fitting we obtain an average number of components in the

  6. Predicting dust extinction properties of star-forming galaxies from H-alpha/UV ratio

    Koyama, Yusei; Hayashi, Masao; Shimakawa, Rhythm; Yamamura, Issei; Egusa, Fumi; Oi, Nagisa; Tanaka, Ichi; Tadaki, Ken-ichi; Takita, Satoshi; Makiuti, Sin'itirou

    2015-01-01

    Using star-forming galaxies sample in the nearby Universe (0.02H-alpha-to-FUV flux ratio. We find that the H-alpha dust extinction (A(Ha)) derived with H-alpha/H-beta ratio (Balmer decrement) increases with increasing H-alpha/UV ratio as expected, but there remains a considerable scatter around the relation, which is largely dependent on stellar mass and/or H-alpha equivalent width (EW(Ha)). At fixed H-alpha/UV ratio, galaxies with higher stellar mass (or galaxies with lower EW(Ha)) tend to be more highly obscured by dust. We quantify this trend and establish an empirical calibration for predicting A(Ha) with a combination of H-alpha/UV ratio, stellar mass and EW(Ha), with which we can successfully reduce the systematic uncertainties accompanying the simple H-alpha/UV approach by ~15-30%. The new recipes proposed in this study will provide a conveni...

  7. Comparison of the equivalent width, the autocorrelation width, and the variance as figures of merit for XPS narrow scans

    Highlights: • We apply the equivalent and autocorrelation widths and variance to XPS narrow scans. • This approach is complementary to traditional peak fitting methods. • It is bias free and responsive to subtle chemical changes in spectra. • It has the potential for machine interpretation of spectra and quality control. • It has the potential for analysis of complex spectra and tracking charging/artifacts. - Abstract: X-ray photoelectron spectroscopy (XPS) is widely used in surface and materials laboratories around the world. It is a near surface technique, providing detailed chemical information about samples in the form of survey and narrow scans. To extract the maximum amount of information about materials it is often necessary to peak fit XPS narrow scans. And while indispensable to XPS data analysis, even experienced practitioners can struggle with their peak fitting. In our previous publication, we introduced the equivalent width (EWXPS) as both a possible machine automated method, one that requires less expert judgment for characterizing XPS narrow scans, and as an approach that may be well suited for the analysis of complex spectra. The EWXPS figure of merit was applied to four different data sets. However, as previously noted, other width functions are also regularly employed for analyzing functions. Here we evaluate two other width functions for XPS narrow scan analysis: the autocorrelation width (AWXPS) and the variance (σXPS2). These widths were applied to the same four sets of spectra studied before: (a) four C 1s narrow scans of ozone-treated carbon nanotubes (CNTs) (EWXPS: ∼2.11–2.16 eV, AWXPS: ∼3.9–4.1 eV, σXPS2: ∼5.0–5.2 eV, and a modified form of σXPS2, denoted σXPS2*: ∼6.3–6.8 eV), (b) silicon wafers with different oxide thicknesses (EWXPS: ∼1.5–2.9 eV, AWXPS: ∼2.28–4.9, and σXPS2: ∼0.7–4.9 eV), (iii) hydrogen-terminated silicon surfaces, before and after modification with pentyl groups, and after

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

    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...

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

    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...

  10. EDDINGTON RATIO GOVERNS THE EQUIVALENT WIDTH OF Mg II EMISSION LINE IN ACTIVE GALACTIC NUCLEI

    We have investigated the ensemble regularities of the equivalent widths (EWs) of Mg II λ2800 emission line of active galactic nuclei (AGNs), using a uniformly selected sample of 2092 Seyfert 1 galaxies and quasars at 0.45 ≤ z ≤ 0.8 in the spectroscopic data set of the Sloan Digital Sky Survey Fourth Data Release. We find a strong correlation between the EW of Mg II and the AGN Eddington ratio (L/LEdd): EW(Mg II) ∝ (L/L Edd)-0.4. Furthermore, for AGNs with the same L/LEdd, their EWs of Mg II show no correlation with luminosity, black hole mass, or line width, and the Mg II line luminosity is proportional to continuum luminosity, as expected by photoionization theory. Our result shows that Mg II EW is not dependent on luminosity, but is solely governed by L/LEdd.

  11. Bayesian Redshift Classification of Emission-line Galaxies with Photometric Equivalent Widths

    Leung, Andrew S; Gawiser, Eric; Ciardullo, Robin; Komatsu, Eiichiro; Zeimann, Gregory R; Bridge, Joanna S; Feldmeier, John J; Finkelstein, Steven L; Gebhardt, Karl; Gronwall, Caryl; Hagen, Alex; Hill, Gary J; Schneider, Donald P

    2015-01-01

    We present a Bayesian approach to the redshift classification of emission-line galaxies when only a single emission line is detected spectroscopically. We consider the case of surveys for high-redshift ${\\rm Ly{\\alpha}}$-emitting galaxies (LAEs), which have traditionally been classified via an inferred rest-frame equivalent width $(W_{\\rm Ly\\alpha})$ greater than $20 {\\rm \\,\\AA}$. Our Bayesian method relies on known prior probabilities in measured emission-line luminosity functions and equivalent width distributions for the galaxy populations in question, and it returns the probability that an object is an LAE given the characteristics observed. This approach will be directly relevant for the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX), which seeks to classify $\\sim$$10^6$ emission-line galaxies into LAEs and low-redshift [O II] emitters. For a simulated HETDEX catalog with realistic measurement noise, our Bayesian method recovers $86\\%$ of LAEs missed by the traditional $W_{\\rm Ly\\alpha} > 20 {\\rm...

  12. H-alpha as a Luminosity Class Diagnostic for K- and M-type Stars

    Jennings, Jeff

    2016-01-01

    We have identified the H-alpha absorption feature as a new spectroscopic diagnostic of luminosity class in K- and M-type stars. From high-resolution spectra of 19 stars with well-determined physical properties (including effective temperatures and stellar radii), we measured equivalent widths for H-alpha and the Ca II triplet and examined their dependence on both luminosity class and stellar radius. H-alpha shows a strong relation with both luminosity class and radius that extends down to late M spectral types. This behavior in H-alpha has been predicted as a result of the density-dependent overpopulation of the metastable 2S level in hydrogen, an effect that should become dominant for Balmer line formation in non-LTE conditions. We conclude that this new metallicity-insensitive diagnostic of luminosity class in cool stars could serve as an effective means of discerning between populations such as Milky Way giants and supergiant members of background galaxies.

  13. Calculations of periodicity from H{\\alpha} profiles of Proxima Centauri

    Collins, John M; Barnes, John R

    2016-01-01

    We investigate retrieval of the stellar rotation signal for Proxima Centauri. We make use of high-resolution spectra taken with uves and harps of Proxima Centauri over a 13-year period as well as photometric observations of Proxima Centauri from asas and hst. We measure the H{\\alpha} equivalent width and H{\\alpha} index, skewness and kurtosis and introduce a method that investigates the symmetry of the line, the Peak Ratio, which appears to return better results than the other measurements. Our investigations return a most significant period of 82.6 $\\pm$ 0.1 days, confirming earlier photometric results and ruling out a more recent result of 116.6 days which we conclude to be an alias induced by the specific harps observation times. We conclude that whilst spectroscopic H{\\alpha} measurements can be used for period recovery, in the case of Proxima Centauri the available photometric measurements are more reliable. We make 2D models of Proxima Centauri to generate simulated H{\\alpha}, finding that reasonable di...

  14. Joint H-alpha and X-Ray Observations of Massive X-Ray Binaries. II. The Be X-ray Binary and Microquasar LS I +61 303

    Grundstrom, E. D.; Caballero-Nieves, S. M.; Gies, D. R.; Huang, W.; McSwain, M. V.; Rafter, S. E.; Riddle, R. L.; Williams, S. J.; Wingert, D. W.

    2006-01-01

    We present the results of an H-alpha monitoring campaign on the BeXRB and microquasar system LS I +61 303. We use radial velocity measurements of HeI lines in our spectra to re-evaluate the orbital elements and to better establish the time of periastron. We list equivalent widths and other parameters for the H-alpha emission line and discuss the orbital phase related variations observed. We call attention to a dramatic episode of emission weakening that occurred in less than a day that probab...

  15. The H-alpha/H-beta ratio in solar flares

    Zirin, H.; Liggett, M.; Patterson, A.

    1982-01-01

    The present investigation involves the study of an extensive body of data accumulated of simultaneous H-alpha and H-beta cinematography of flares. The data were obtained with two telescopes simultaneously photographing flares in H-alpha and H-beta. The results of measurements in a number of flares are presented in a table. The flares were selected purely by optical quality of the data. That the measured ratios are not too different from those in stellar flares is suggested by the last two columns of the table. These columns show that a variety of possible line width ratios could give an integrated intensity ratio of less than unity.

  16. From HI to Stars: HI Depletion in Starbursts and Star-Forming Galaxies in the ALFALFA H-alpha Survey

    Jaskot, A E; Salzer, J J; Van Sistine, A; Bell, E F; Haynes, M P

    2015-01-01

    HI in galaxies traces the fuel for future star formation and reveals the effects of feedback on neutral gas. Using a statistically uniform, HI-selected sample of 565 galaxies from the ALFALFA H-alpha survey, we explore HI properties as a function of star formation activity. ALFALFA H-alpha provides R-band and H-alpha imaging for a volume-limited subset of the 21-cm ALFALFA survey. We identify eight starbursts based on H-alpha equivalent width and six with enhanced star formation relative to the main sequence. Both starbursts and non-starbursts have similar HI to stellar mass ratios (MHI/M*), which suggests that feedback is not depleting the starbursts' HI. Consequently, the starbursts do have shorter HI depletion times (t_dep), implying more efficient HI-to-H2 conversion. While major mergers likely drive this enhanced efficiency in some starbursts, the lowest mass starbursts may experience periodic bursts, consistent with enhanced scatter in t_dep at low M*. Two starbursts appear to be pre-coalescence mergers...

  17. Voigt equivalent widths and spectral-bin single-line transmittances: Exact expansions and the MODTRAN®5 implementation

    Berk, Alexander

    2013-03-01

    Exact expansions for Voigt line-shape total, line-tail and spectral bin equivalent widths and for Voigt finite spectral bin single-line transmittances have been derived in terms of optical depth dependent exponentially-scaled modified Bessel functions of integer order and optical depth independent Fourier integral coefficients. The series are convergent for the full range of Voigt line-shapes, from pure Doppler to pure Lorentzian. In the Lorentz limit, the expansion reduces to the Ladenburg and Reiche function for the total equivalent width. Analytic expressions are derived for the first 8 Fourier coefficients for pure Lorentzian lines, for pure Doppler lines and for Voigt lines with at most moderate Doppler dependence. A strong-line limit sum rule on the Fourier coefficients is enforced to define an additional Fourier coefficient and to optimize convergence of the truncated expansion. The moderate Doppler dependence scenario is applicable to and has been implemented in the MODTRAN5 atmospheric band model radiative transfer software. Finite-bin transmittances computed with the truncated expansions reduce transmittance residuals compared to the former Rodgers-Williams equivalent width based approach by ∼2 orders of magnitude.

  18. Equivalent width of copper and potassium resonance lines at 3247.54, 7665 Angst for Voigt profile by atomic absorption measurements

    Habib, A.A.M. E-mail: azhabib@yahoo.com

    2004-03-15

    A simple reliable theoretical approach is developed to calculate the equivalent width of copper and potassium resonance lines at 3247.54 and 7665 Angst using atomic absorption techniques. The calculations have been carried out for the two limiting cases of a pure Doppler (Gaussian) and Lorentzian (dispersion) line profiles. The more general case of a Voigt line profile leads to an efficient analytical formula permits a rapid estimate of the equivalent width with sufficient precision. The reliability of the approach has been verified by providing the curves of growth for the given spectral lines to describe the behavior of the equivalent width as the number of absorbing atoms in the ground state is increased. Allowance is made in the analysis for the dependence of the equivalent width for Voigt profile on the damping constant {alpha}, which is a measure of the half width of Lorentz profile relative to the Doppler profile.

  19. Grid of theoretical NLTE equivalent widths of four Ba II lines and barium abundance in cool stars

    Korotin, S A; Hansen, C J; Caffau, E; Bonifacio, P; Spite, M; Spite, F; Francois, P

    2015-01-01

    We present a grid of computed non-local thermodynamic equilibrium (NLTE) equivalent widths (EW) and NLTE abundance corrections for four Ba II lines: 4554, 5853, 6141, and 6496 A. The grid can be useful in deriving the NLTE barium abundance in stars having parameters in the following ranges: effective temperature from 4000 K to 6500 K, surface gravity log g from 0 to 5, microturbulent velocity 0 km s^-1 to 3 km s^-1, metallicity [Fe/H] from -2 to +0.5, and [Ba/Fe] from -0.4 to +0.6. The NLTE abundance can be either derived by EW interpolation (using the observed Ba II line EW) or by using the NLTE correction applied to a previously determined LTE abundance. Ba II line equivalent widths and the NLTE corrections were calculated using the updated MULTI code and the Ba II atomic model that was previously applied to determine the NLTE barium abundance in different types of stars. The grid is available on-line through the web, and we find that the grid Ba NLTE corrections are almost as accurate as direct NLTE profil...

  20. Discovery of Massive, Mostly Star-formation Quenched Galaxies with Extremely Large Lyman-alpha Equivalent Widths at z ~ 3

    Taniguchi, Yoshiaki; Kobayashi, Masakazu A R; Nagao, Tohru; Shioya, Yasuhiro; Scoville, Nick Z; Sanders, David B; Capak, Peter L; Koekemoer, Anton M; Toft, Sune; McCracken, Henry J; Fevre, Olivier Le; Tasca, Lidia; Sheth, Kartik; Renzini, Alvio; Lilly, Simon; Carollo, Marcella; Kovac, Katarina; Ilbert, Olivier; Schinnerer, Eva; Fu, Hai; Tresse, Laurence; Griffiths, Richard E; Civano, Francesca

    2015-01-01

    We report a discovery of 6 massive galaxies with both extremely large Lya equivalent width and evolved stellar population at z ~ 3. These MAssive Extremely STrong Lya emitting Objects (MAESTLOs) have been discovered in our large-volume systematic survey for strong Lya emitters (LAEs) with twelve optical intermediate-band data taken with Subaru/Suprime-Cam in the COSMOS field. Based on the SED fitting analysis for these LAEs, it is found that these MAESTLOs have (1) large rest-frame equivalent width of EW_0(Lya) ~ 100--300 A, (2) M_star ~ 10^10.5--10^11.1 M_sun, and (3) relatively low specific star formation rates of SFR/M_star ~ 0.03--1 Gyr^-1. Three of the 6 MAESTLOs have extended Ly$\\alpha$ emission with a radius of several kpc although they show very compact morphology in the HST/ACS images, which correspond to the rest-frame UV continuum. Since the MAESTLOs do not show any evidence for AGNs, the observed extended Lya emission is likely to be caused by star formation process including the superwind activit...

  1. Solar Imagery - Chromosphere - H-Alpha

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of H-alpha photographic datasets contributed by a number of national and private solar observatories located worldwide. Solar...

  2. Photometric and H-alpha studies of two extreme mass-ratio short period contact binaries in the direction of open cluster Praesepe

    Rukmini, J

    2016-01-01

    We present the high precession photometric studies in V band and spectroscopic studies centered around H-alpha line for two extreme mass-ratio short period contact binaries ASAS J082243+1927.0 (V1) and ASAS J085710+1856.8 (V2). The variables in study are in the direction of open cluster Praesepe. From the light curve analysis V1 was found to be a low mass-ratio over-contact binary of A-type, with a mass ratio q 0.121 and fill-out factor f 72%, and V2 was found to be a low mass contact binary of W-type, with a mass-ratio q 1.29 and fill-out factor f 11% (marginal contact). The study of H-alpha absorption line profile of both the variables shows variation in equivalent widths (EWs) with orbital phases. The mean EWs of the H-alpha line were obtained as 1.6+or-0.13 A and 1.18+or-0.12 A for V1 and V2 respectively. The variation of H-alpha absorption with respect to phase is explained to be due to chromospheric activity in V1, as evident from the O Connell effect and that due to chromospheric flares, winds or photo...

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

    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 ...

  4. Statistics of equivalent width data and new oscillator strengths for Si II, Fe II, and Mn II. [in interstellar medium

    Van Buren, Dave

    1986-01-01

    Equivalent width data from Copernicus and IUE appear to have an exponential, rather than a Gaussian distribution of errors. This is probably because there is one dominant source of error: the assignment of the background continuum shape. The maximum likelihood method of parameter estimation is presented for the case of exponential statistics, in enough generality for application to many problems. The method is applied to global fitting of Si II, Fe II, and Mn II oscillator strengths and interstellar gas parameters along many lines of sight. The new values agree in general with previous determinations but are usually much more tightly constrained. Finally, it is shown that care must be taken in deriving acceptable regions of parameter space because the probability contours are not generally ellipses whose axes are parallel to the coordinate axes.

  5. High-Resolution Near-Infrared Spectroscopy of an Equivalent Width-Selected Sample of Starbursting Dwarf Galaxies

    Maseda, Michael V.; VanDerWeL, Arjen; DaChuna, Elisabete; Rix, Hans-Walter; Pacafichi, Camilla; Momcheva, Ivelina; Brammer, Gabriel B.; Franx, Marijn; VanDokkum, Pieter; Bell, Eric F.; Ferguson, Harry C.; Fumagalli, Mattia; Grogin, Norman A.; Kocevski, Dale D.; Koekemoer, Anton M.; Lundgren, Britt F.; Marchesini, Danilo; Nelson, Erica J.; Patel, Shannon; Skelton, Rosalind E.; Straughn, Amber N.; Trump, Jonathan R.; Weiner, Benjamin J.; Whitaker, Katherine E.; Wuyts, Stijn

    2013-01-01

    Spectroscopic observations from the Large Binocular Telescope and the Very Large Telescope reveal kinematically narrow lines (approx. 50 km/s) for a sample of 14 Extreme Emission Line Galaxies (EELGs) at redshifts 1.4 < zeta < 2.3. These measurements imply that the total dynamical masses of these systems are low ( 3 × 10(exp 9) M). Their large [O III]5007 equivalent widths (500 - 1100 A) and faint blue continuum emission imply young ages of 10-100 Myr and stellar masses of 10(exp 8)-10(exp 9) M, confirming the presence of a violent starburst. The stellar mass formed in this vigorous starburst phase thus represents a large fraction of the total (dynamical) mass, without a significantly massive underlying population of older stars. The occurrence of such intense events in shallow potentials strongly suggests that supernova-driven winds must be of critical importance in the subsequent evolution of these systems.

  6. DEFPOS H${\\alpha}$ Observations of W80 Complex

    Aksaker, Naz\\im

    2012-01-01

    We present H${\\alpha}$ emission line measurements of the W80 nebular complex. A total of 26 regions have been observed inside the nebula with the Dual Etalon Fabry-Perot Optical Spectrometer (DEFPOS) system at the f/48 Coude focus of 150 cm RTT150 telescope located at TUBITAK National Observatory (TUG) in Antalya/Turkey. The intensities, the local standard of rest (LSR) velocities ($V_{LSR}$), heliocentric radial velocities ($V_{HEL}$) and the linewidths at Full Width at Half Maximum (FWHM) of the H${\\alpha}$ emission lines have been determined from these observations. They lie in the range of 259 to 1159 Rayleigh {1R = 10$^{6}/4\\pi$ photons cm$^{-2}$ sr$^{-1}$ s$^{-1}$ = 2.4110$^{-7}$ erg cm$^{-2}$ sr$^{-1}$ s$^{-1}$ at H${\\alpha}$.} (R), 4 to 12 km s$^{-1}$ and 44 to 55 km s$^{-1}$, respectively. The radial velocity measurements show that there are several maxima and minima inside the W80. The new results confirm the literature that complex seems to be rather a uniform in radial velocity and no seen turbule...

  7. Temporal evolution of mottles observed in H_alpha

    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.

  8. H-alpha Observations of MKW10

    Johnson, Harold; Coble, Kimberly A.; Koopmann, Rebecca A.; Durbala, Adriana; Undergraduate ALFALFA Team

    2016-01-01

    As part of the Undergraduate ALFALFA Team project looking at clusters and groups of galaxies to investigate the effects of environment on star formation, we analyzed H-alpha and R-band observations of the group MKW10 from the WIYN 0.9-m telescope with MOSAIC camera at Kitt Peak. We continuum-subtract the H-alpha images by scaling and subtracting the broadband R images. This process includes: determining the seeing of each image by calculating the FWHM values of several stars in the image; convolving all images to the worst seeing; stacking images for each filter; subtracting sky background; scaling the R image to H-alpha; and subtracting the scaled R from H-alpha. We then use the H-alpha-continuum-subtracted image to perform surface photometry of individual galaxies in MKW10. The data will be used to determine star formation rates and distributions of galaxies in this group environment and will be compared to results for galaxies in other UAT group and cluster environments. Analysis is ongoing.This work has been supported by NSF grant AST-1211005 and the Illinois Space Grant Consortium.

  9. Scale heights and equivalent widths of the iron K-shell lines in the Galactic diffuse X-ray emission

    Yamauchi, Shigeo; Nobukawa, Masayoshi; Uchiyama, Hideki; Koyama, Katsuji

    2016-01-01

    This paper reports the analysis of the X-ray spectra of the Galactic diffuse X-ray emission (GDXE) in the Suzaku archive. The fluxes of the Fe I K alpha (6.4 keV), Fe XXV,He alpha (6.7 keV) and Fe XXVI Ly alpha (6.97 keV) lines are separately determined. From the latitude distributions, we confirm that the GDXE is decomposed into the Galactic center (GCXE), the Galactic bulge (GBXE) and the Galactic ridge (GRXE) X-ray emissions. The scale heights (SHs) of the Fe XXV He alpha line of the GCXE, GBXE and GRXE are determined to be ~40, ~310 and ~140 pc, while those of the Fe I K alpha line are ~30, ~160 and ~70 pc, respectively. The mean equivalent widths (EWs) of the sum of the Fe XXV He alpha and Fe XXVI Ly alpha lines are ~750 eV, ~600 eV and ~550 eV, while those of the Fe I K alpha line are ~150~eV, ~60~eV and ~100~eV for the GCXE, GBXE and GRXE, respectively. The origin of the GBXE, GRXE and GCXE is separately discussed based on the new results of the SHs and EWs, in comparison with those of the Cataclysmic ...

  10. EQUIVALENT WIDTHS FROM THE 3D-HST SURVEY: EVOLUTION WITH REDSHIFT AND DEPENDENCE ON STELLAR MASS

    We investigate the evolution of the Hα equivalent width, EW(Hα), 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 Hα measurements of 854 galaxies at 0.8 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(Hα) to specific star formation rate (sSFR) is model dependent because of differential reddening corrections between the continuum and the Balmer lines. The observed EW(Hα) can be reproduced with the characteristic evolutionary history for galaxies, whose star formation rises with cosmic time to z ∼ 2.5 and then decreases to z = 0. This implies that EW(Hα) rises to 400 Å at z = 8. The sSFR evolves faster than EW(Hα), as the mass-to-light ratio also evolves with redshift. We find that the sSFR evolves as (1 + z)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.

  11. H$\\alpha$ kinematics of KPG 390

    Repetto, P; Fuentes-Carrera, R Gabbasov I

    2009-01-01

    In this work we present scanning Fabry-Perot H$\\alpha$ observations of the isolated interacting galaxy pair NGC 5278/79 obtained with the PUMA Fabry-Perot interferometer. We derived velocity fields, various kinematic parameters and rotation curves for both galaxies. Our kinematical results together with the fact that dust lanes have been detected in both galaxies, as well as the analysis of surface brightness profiles along the minor axis, allowed us to determine that both components of the interacting pair are trailing spirals.

  12. Discovery of a very cool object with extraordinarily strong H(alpha) emission

    Barrado y Navascués, D; Martín, E L; Béjar, V J S; Rebolo, R; Mundt, R; Navascues, David Barrado y; Osorio, Maria Rosa Zapatero; Martin, Eduardo L.; Bejar, Victor J.S.; Rebolo, Rafael; Mundt, Reinhard

    2002-01-01

    We report on the finding of the strongest H(alpha) emission -pseudoequivalent width of 705 Angstrom- known so far in a young, late type dwarf. This object, named as SOri71, is a substellar candidate member of the 1-8 Myr star cluster sigma Orionis. Due to its overluminous location in color-magnitude diagrams, SOri71 might be younger than other cluster members, or a binary of similar components. Its mass is in the range 0.021-0.012 M(sun), depending on evolutionary models and possible binarity. The broad H(alpha) line of SOri71 appears asymmetric, indicative of high velocity mass motions in the H(alpha) forming region. The origin of this emission is unclear at the present time. We discuss three possible scenarios: accretion from a disk, mass exchange between the components of a binary system, and emission from a chromosphere.

  13. The H-alpha Galaxy Survey II. Extinction and NII corrections to H-alpha fluxes

    James, P A; Knapen, J H; Etherton, J; Percival, S M

    2004-01-01

    We study the two main corrections generally applied to narrow-band H-alpha fluxes from galaxies in order to convert them to star formation rates, namely for NII contamination and for extinction internal to the galaxy. From an imaging study using narrow-band filters, we find the NII and H-alpha emission to be differently distributed. In most disk star formation regions the NII fraction is small, whereas some galaxies display a diffuse central component which can be dominated by NII emission. We consider explanations for variations in the NII/H-alpha ratio, including metallicity variations and different excitation mechanisms. We then estimate the extinction towards star formation regions in spiral galaxies, firstly using Br-gamma/H-alpha line ratios. We find that extinction values are larger in galaxy nuclei than in disks, and that there is no evidence for heavily dust-embedded regions emerging in the near-IR. We use optical emission line data from the literature to show only a moderate dependence of extinction...

  14. The Appearance of Spicules in High Resolution Observations of Ca II H and H-alpha

    Pereira, Tiago M D; Carlsson, Mats

    2016-01-01

    Solar spicules are chromospheric fibrils that appear everywhere on the Sun, yet their origin is not understood. Using high resolution observations of spicules obtained with the Swedish 1-m Solar Telescope we aim to understand how spicules appear in filtergrams and Dopplergrams, how they compare in Ca II H and H-alpha, and what can make them appear and disappear. We find spicules display a rich and detailed spatial structure, and show a distribution of transverse velocities that when aligned with the line of sight can make them appear at different H-alpha wing positions. They become more abundant at positions closer to the line core, reflecting a distribution of Doppler shifts and widths. In H-alpha width maps they stand out as bright features both on disk and off-limb, reflecting their large Doppler motions and possibly higher temperatures than in the typical H-alpha formation region. Spicule lifetimes measured from narrowband images at only a few positions will be an underestimate because Doppler shifts can ...

  15. A submillimeter protostar mear LkH-alpha 198

    Sandell, Goran; Weintraub, David A.

    1994-01-01

    We present submillimeter and millimeter line and continuum observations of the region around LkH-alpha 198 and V376 Cas. The continuum data reveal the presence of a very cool object, LkH-alpha 198 MM located approximately 19 sec northwest of LkH-alpha 198. LkH-alpha 198 MM is not visible in the near-IR. The CO maps suggest that the mm-source, rather than LkH-alpha 198 or its IR companion LkH-alpha 198B, may drive the large CO outflow seen in this cloud or that both drive outflows which are roughly aligned with each other. In addition V376 Cas appears to power a small bipolar CO outflow.

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

    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...

  17. Galactic Free-free and H-alpha Emission

    Smoot, George F.

    1998-01-01

    This document provides a brief summary estimate of Galactic free-free emission and H-alpha emission and their relationship. Particular emphasis is placed on estimating the potential free-free emission in the region of significant confusion for CMB anisotropy measurements. Existing x-ray, ultraviolet and H$\\alpha$ emission provide limits on the radio free-free emission and vice versa. These limits are generally somewhat smaller than the observed ``free-free'' (signal proportional to frequency^...

  18. H$\\alpha$ Imaging spectroscopy of Balmer-dominated shocks in Tycho's supernova remnant

    Knežević, Sladjana; van de Ven, Glenn; Font, Joan; Raymond, John C; Ghavamian, Parviz; Beckman, John

    2016-01-01

    We present Fabry-P\\'erot interferometric observations of the narrow H$\\alpha$ component in the shock front of the historical supernova remnant Tycho (SN 1572). Using GH$\\alpha$FaS (Galaxy H$\\alpha$ Fabry-P\\'erot Spectrometer) on the William Herschel Telescope, we observed a great portion of the shock front in the northeastern (NE) region of the remnant. The angular resolution of $\\sim$1$^{\\prime\\prime}$ and spectral resolving power of R$\\sim$21 000 together with the large field-of-view (3.4$^{\\prime}$ $\\times$ 3.4$^{\\prime}$) of the instrument allow us to measure the narrow H$\\alpha$-line width in 73 bins across individual parts of the shock simultaneously and thereby study the indicators of several shock precursors in a large variety of shock front conditions. Compared to previous studies, the detailed spatial resolution of the filament also allows us to mitigate possible artificial broadening of the line from unresolved differential motion and projection. Covering one quarter of the remnant's shell, we conf...

  19. The evolution of the equivalent width of the Ha emission line and specific star-formation rate in star-forming galaxies at 1

    Marmol-Queralto, E; Cullen, F; Dunlop, J S; Fontana, A; McLeod, D J

    2015-01-01

    We present the results of a study which uses spectral energy distribution (SED) fitting to investigate the evolution of the equivalent width (EW) of the Halpha emission line in star-forming galaxies over the redshift interval 1=1 in the CANDELS UDS and GOODS-S fields. Confining our analysis to a constant stellar mass range (9.5

  20. The evolution of the equivalent width of the Hα emission line and specific star formation rate in star-forming galaxies at 1 < z < 5

    Mármol-Queraltó, E.; McLure, R. J.; Cullen, F.; Dunlop, J. S.; Fontana, A.; McLeod, D. J.

    2016-08-01

    We present the results of a study which uses spectral energy distribution (SED) fitting to investigate the evolution of the equivalent width (EW) of the Halpha emission line in star-forming galaxies over the redshift interval 1=1 in the CANDELS UDS and GOODS-S fields. Confining our analysis to a constant stellar mass range (9.5evolution of EW(Ha) and specific star-formation rate (sSFR). Our results indicate that over the redshift range 1evolution displayed by EW(Ha) and sSFR is consistent, and can be adequately parameterized as: propto (1+z)^(1.0+/-0.2). As a consequence, over this redshift range we find that the sSFR and rest-frame EW(Ha) of star-forming galaxies with stellar masses M~10^(10) Msun are related by: EW(Ha)/Ang=(63+/-7)sSFR/Gyr^(-1). Given the current uncertainties in measuring the SFRs of high-redshift galaxies, we conclude that EW(Ha) provides a useful independent tracer of sSFR for star-forming galaxies out to redshifts of z=5.

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

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

    2013-01-01

    The AAO/UKST SuperCOSMOS H-alpha Survey (SHS) of the southern Galactic plane was, when completed in 2003, a powerful new addition to wide-field surveys. It has a combination of areal coverage, spatial resolution and flux sensitivity in a narrow imaging band which 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, and new digital H-alpha surveys now beginning in the south such as VPHAS+. The SHS has been the foundation of many important follow-up discovery projects in the southern sky with the Macquarie/AAO/Strasbourg H-alpha (MASH) planetary nebula project being a particularly successful example. However, the full astrophysical potential of the SHS has been hampered by lack of a clear route to acceptable flux calibration from the base photographic data. We have determined the calibration factors for 170 sep...

  2. Galactic Free-free and H$\\alpha$ Emission

    Smoot, G F

    1998-01-01

    This document provides a brief summary estimate of Galactic free-free emission and H-alpha emission and their relationship. Particular emphasis is placed on estimating the potential free-free emission in the region of significant confusion for CMB anisotropy measurements. Existing x-ray, ultraviolet and H$\\alpha$ emission provide limits on the radio free-free emission and vice versa. These limits are generally somewhat smaller than the observed ``free-free'' (signal proportional to frequency^{-2.15}) microwave signal. If this remains true, then some previously neglected source may be present. Physics argues that H-alpha emission is still the best tracer for Galactic free-free emission and thus a tool for diagnosing if there is previously neglected source.

  3. H-alpha features with hot onsets. I. Ellerman bombs

    Rutten, R J

    2016-01-01

    Ellerman bombs are transient brightenings of the wings of the Balmer lines that uniquely mark reconnection in the solar photosphere. They are also bright in strong Ca II and ultraviolet lines and in ultraviolet continua, but they are not visible in the optical continuum and the Na I D and Mg I b lines. These discordant visibilities invalidate all published Ellerman bomb modeling. I argue that the assumption of Saha-Boltzmann lower-level populations is informative to estimate bomb-onset opacities for these diverse diagnostics, even and especially for H-alpha, and employ such estimates to gauge the visibilities of Ellerman bomb onsets in all of them. They constrain Ellerman bomb formation to temperatures 10,000 - 20,000 K and hydrogen densities around 10^15 cm^-3. Similar arguments likely hold for H-alpha visibility in other transient phenomena with hot and dense onsets.

  4. Galactic Plane H$\\alpha$ Surveys: IPHAS & VPHAS+

    Wright, Nicholas J

    2015-01-01

    The optical Galactic Plane H$\\alpha$ surveys IPHAS and VPHAS+ are dramatically improving our understanding of Galactic stellar populations and stellar evolution by providing large samples of stars in short lived, but important, evolutionary phases, and high quality homogeneous photometry and images over the entire Galactic Plane. Here I summarise some of the contributions these surveys have already made to our understanding of a number of key areas of stellar and Galactic astronomy.

  5. H{\\alpha} Imaging of Nearby Seyfert Host Galaxies

    Theios, R L; Ross, N R

    2016-01-01

    We used narrowband interference filters with the CCD imaging camera on the Nickel 1.0 meter telescope at Lick Observatory to observe 31 nearby (z < 0.03) Seyfert galaxies in the 12 {\\mu}m Active Galaxy Sample. We obtained pure emission line images of each galaxy in order to separate H{\\alpha} emission from the nucleus from that of the host galaxy. The extended H{\\alpha} emission is expected to be powered by newly formed hot stars, and correlates well with other indicators of current star formation in these galaxies: 7.7 {\\mu}m PAH, far-infrared, and radio luminosity. Relative to what would be expected from recent star formation, there is a 0.8 dex excess of radio emission in our Seyfert galaxies. The nuclear H{\\alpha} luminosity is dominated by the AGN, and is correlated with the hard X-ray luminosity. There is an upward offset of 1 dex in this correlation for the Seyfert 1s due to a strong contribution from the Broad Line Region. We found a correlation between star formation rate and AGN luminosity. In sp...

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

    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...

  7. The H alpha Galaxy Survey. III. Constraints on supernova progenitors from spatial correlations with H alpha emission

    James, P A

    2006-01-01

    Aims: We attempt to constrain progenitors of the different types of supernovae from their spatial distributions relative to star formation regions in their host galaxies, as traced by H alpha + NII line emission. Methods: We analyse 63 supernovae which have occurred within galaxies from our H alpha survey of the local Universe. Three statistical tests are used, based on pixel statistics, H alpha radial growth curves, and total galaxy emission-line fluxes. Results: Many more type II supernovae come from regions of low or zero emission line flux than would be expected if the latter accurately traces high-mass star formation. We interpret this excess as a 40% `Runaway' fraction in the progenitor stars. Supernovae of types Ib and Ic do appear to trace star formation activity, with a much higher fraction coming from the centres of bright star formation regions than is the case for the type II supernovae. Type Ia supernovae overall show a weak correlation with locations of current star formation, but there is evide...

  8. Observations of H-alpha Polarization in Flares

    Mickey, D. L.; Metcalf, T. R.; Fletcher, L.

    2000-05-01

    Max Millennium Coordinated Observing Plan #006 has as its goal the measurement of H-alpha linear polarization, a possible signature of low-energy proton beams in solar flares. Such observations have been attempted in the past, but the results were inconclusive. A campaign involving Mees Solar Observatory and Big Bear Solar Observatory, together with Yohkoh, SOHO and TRACE spacecraft, was carried out during the latter half of March 2000. We present preliminary results from the observations with the Imaging Vector Magnetograph at Mees Solar Observatory. The IVM was operated in a standard mode, except that the spectral scan was limited to one point in the core of H-alpha and one in the blue wing. This limited spectral sampling, together with a recently upgraded data acquisition system, permitted a complete measurement of Stokes vectors every 3.5 seconds. The field of view was 280 arc sec square, with one arc sec pixels. A second camera, exposed simultaneously but with a broad-band filter, provides images which allow compensation for relative image motion and stretch between exposures. Approximately two dozen flares were observed by the IVM during the campaign, including one X-class and one M-class flare. We present samples of the observations, including relevant spacecraft observations, and discuss the sensitivity of the IVM to linear polarization under these conditions. This work was supported in part by the SXT project at LMSAL (contract NAS5-38099) and by NASA grant NAG5-4941.

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

    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...

  10. Spectral Properties From Lyman-alpha to H-alpha For An Essentially Complete Sample of Quasars I: Data

    Shang, Z; Wills, D; Brotherton, M S; Shang, Zhaohui; Wills, Beverley J.; Brotherton, Michael S.

    2007-01-01

    We have obtained quasi-simultaneous ultraviolet-optical spectra for 22 out of 23 quasars in the complete PG-X-ray sample with redshift, z<0.4, and M_B<-23. The spectra cover rest-frame wavelengths from at least Lyman-alpha to H-alpha. Here we provide a detailed description of the data, including careful spectrophotometry and redshift determination. We also present direct measurements of the continua, strong emission lines and features, including Lyman-alpha, SiIV+OIV], CIV, CIII], SiIII], MgII, H-beta, [OIII], He5876+NaI5890,5896, H-alpha, and blended iron emission in the UV and optical. The widths, asymmetries and velocity shifts of profiles of strong emission lines show that CIV and Lyman-alpha are very different from H-beta and H-alpha. This suggests that the motion of the broad line region is related to the ionization structure, but the data appears not agree with the radially stratified ionization structure supported by reverberation mapping studies, and therefore suggest that outflows contribute a...

  11. The interacting galaxy pair KPG 390: H$\\alpha$ kinematics

    Repetto, P; Gabbasov, R; Fuentes-Carrera, I

    2010-01-01

    In this work we present scanning Fabry-Perot H$\\alpha$ observations of the isolated interacting galaxy pair NGC 5278/79 obtained with the PUMA Fabry-Perot interferometer. We derived velocity fields and rotation curves for both galaxies. For NGC 5278 we also obtained the residual velocity map to investigate the non-circular motions, and estimated its mass by fitting the rotation curve with a disk+halo components. We test three different types of halo (pseudo-isothermal, Hernquist and Navarro Frenk White) and obtain satisfactory fits to the rotation curve for all profiles. The amount of dark matter required by pseudo-isothermal profile is about ten times smaller than, that for the other two halo distributions. Finally, our kinematical results together with the analysis of dust lanes distribution and of surface brightness profiles along the minor axis allowed us to determine univocally that both components of the interacting pair are trailing spirals.

  12. High spatial resolution optical imaging of the multiple T Tauri system LkH{\\alpha} 262/LkH{\\alpha} 263

    Velasco, S; Oscoz, A; Mackay, C; Labadie, L; Garrido, A Pérez; Crass, J; Díaz-Sánchez, A; Femenía, B; González-Escalera, V; King, D L; López, R L; Puga, M; Rodríguez-Ramos, L F; Zuther, J

    2016-01-01

    We report high spatial resolution i' band imaging of the multiple T Tauri system LkH$\\alpha$ 262/LkH$\\alpha$ 263 obtained during the first commissioning period of the Adaptive Optics Lucky Imager (AOLI) at the 4.2 m William Herschel Telescope, using its Lucky Imaging mode. AOLI images have provided photometry for each of the two components LkH$\\alpha$ 263 A and B (0.41 arcsec separation) and marginal evidence for an unresolved binary or a disc in LkH$\\alpha$ 262. The AOLI data combined with previously available and newly obtained optical and infrared imaging show that the three components of LkH$\\alpha$ 263 are co-moving, that there is orbital motion in the AB pair, and, remarkably, that LkH$\\alpha$ 262-263 is a common proper motion system with less than 1 mas/yr relative motion. We argue that this is a likely five-component gravitationally bounded system. According to BT-settl models the mass of each of the five components is close to 0.4 M$_{\\odot}$ and the age is in the range 1-2 Myr. The presence of discs...

  13. The Wisconsin H-Alpha Mapper Sky Survey

    Haffner, L. Matthew; Reynolds, Ronald J.; Babler, Brian L.; Madsen, Gregory J.; Hill, Alex S.; Barger, Kathleen; Jaehnig, Kurt P.; Mierkiewicz, Edwin J.; Percival, Jeffrey W.; Chopra, Nitish; Pingel, Nickolas; Reese, Daniel T.; Gostisha, Martin; Wunderlin, Jennifer

    2016-01-01

    We present the first all-sky, kinematic survey of Hα from the Milky Way, combining survey observations taken with the Wisconsin H-Alpha Mapper (WHAM) from Kitt Peak (1997-2007) and Cerro Tololo (2009-present). The WHAM Sky Survey (WHAM-SS) reaches sensitivity levels of about 0.1 R (EM ~ 0.2 pc cm^-6) with emission detected toward every direction in the sky. Each pointing of the survey comprises a spatially integrated spectrum from a one-degree beam on the sky covering at least 200 km/s around the Local Standard of Rest with 12 km/s spectral resolution. WHAM was designed primarily to study the pervasive warm ionized medium (WIM) component of the interstellar medium (ISM) but also reveals many large-scale, locally-ionized regions throughout the Galaxy. The WIM is a diffuse but thick component of the ISM that extends several kiloparsecs into the Galactic halo with a kinematic signature that traces the gaseous spiral arms of the Galaxy. In addition to this fairly smooth global emission, the Hα sky contains many individual H II regions and supernova remnants, a few revealed in the WHAM-SS for the first time. Some locations are dominated by complex filamentary network of diffuse ionized gas where the ISM has been shaped by past winds and supernovae and is now powered by a new wave of star formation. At high latitudes, faint emission from intermediate-velocity clouds is also regularly present. The success of WHAM as a fully remote observing facility for nearly two decades is due in no small part to the excellent and responsive support staff at KPNO in Arizona and CTIO in Chile. WHAM has been designed, built, and operated primarily through support of the National Science Foundation. The current research presented here is funded by award AST-1108911.

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

    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...

  15. Dust Attenuation and H(alpha) Star Formation Rates of Z Approx. 0.5 Galaxies

    Ly, Chun; Malkan, Matthew A.; Kashikawa, Nobunari; Ota, Kazuaki; Shimasaku, Kazuhiro; Iye, Masanori; Currie, Thayne

    2012-01-01

    Using deep narrow-band and broad-band imaging, we identify 401 z approximately 0.40 and 249 z approximately 0.49 H-alpha line-emitting galaxies in the Subaru Deep Field. Compared to other H-alpha surveys at similar redshifts, our samples are unique since they probe lower H-alpha luminosities, are augmented with multi-wavelength (rest-frame 1000AA--1.5 microns) coverage, and a large fraction (20%) of our samples has already been spectroscopically confirmed. Our spectra allow us to measure the Balmer decrement for nearly 60 galaxies with H-beta detected above 5-sigma. The Balmer decrements indicate an average extinction of A(H-alpha)=0.7(uparrow){+1.4}_{-0.7} mag. We find that the Balmer decrement systematically increases with higher H-alpha luminosities and with larger stellar masses, in agreement with previous studies with sparser samples. We find that the SFRs estimated from modeling the spectral energy distribution (SED) is reliable---we derived an "intrinsic" H-alpha luminosity which is then reddened assuming the color excess from SED modeling. The SED-predicted H-alpha luminosity agrees with H-alpha narrow-band measurements over 3 dex (rms of 0.25 dex). We then use the SED SFRs to test different statistically-based dust corrections for H-alpha and find that adopting one magnitude of extinction is inappropriate: galaxies with lower luminosities are less reddened. We find that the luminosity-dependent dust correction of Hopkins et al. yields consistent results over 3 dex (rms of 0.3 dex). Our comparisons are only possible by assuming that stellar reddening is roughly half of nebular reddening. The strong correspondence argue that with SED modeling, we can derive reliable intrinsic SFRs even in the absence of H-alpha measurements at z approximately 0.5.

  16. Chromospheric features of LQ Hydrae from H-alpha line profiles

    Frasca, A; Strassmeier, K G; Biazzo, K

    2008-01-01

    We analyze the H-alpha spectral variability of the rapidly-rotating K1-dwarf LQ Hya using high-resolution H-alpha spectra recorded during April-May 2000. Chromospheric parameters were computed from the H-alpha profile as a function of rotational phase. We find that all these parameters vary in phase, with a higher chromospheric electron density coinciding with the maximum H-alpha emission. We find a clear rotational modulation of the H-alpha emission that is better emphasized by subtracting a reference photospheric template built up with a spectrum of a non-active star of the same spectral type. A geometrical plage model applied to the H-alpha variation curve allows us to derive the location of the active regions that come out to be close in longitude to the most pronounced photospheric spots found with Doppler imaging applied to the photospheric lines in the same spectra. Our analysis suggests that the H-alpha features observed in LQ Hya in 2000 are a scaled-up version of the solar plages as regards dimensio...

  17. H-alpha features with hot onsets III. Fibrils in Lyman-alpha and with ALMA

    Rutten, Robert J

    2016-01-01

    In H-alpha most of the solar surface is covered by a dense canopy of long opaque fibrils, but predictions for quiet-Sun observations with ALMA have ignored this fact. Comparison with Ly-alpha suggests that the large opacity of H-alpha fibrils is caused by hot precursor events. Application of a recipe that assumes momentary Saha-Boltzmann extinction during their hot onset to millimeter wavelengths suggests that ALMA will observe the H-alpha fibril canopy, not acoustic shocks underneath, and will yield data more interesting than if this canopy were transparent.

  18. Extracting H$\\alpha$ flux from photometric data in the J-PLUS survey

    Vilella-Rojo, G; López-Sanjuan, C; Cenarro, A J; Varela, J; Díaz-García, L A; Cristóbal-Hornillos, D; Ederoclite, A; Marín-Franch, A; Moles, M

    2015-01-01

    We present the main steps that will be taken to extract H$\\alpha$ emission flux from Javalambre Photometric Local Universe Survey (J-PLUS) photometric data. For galaxies with $z\\lesssim0.015$, the H$\\alpha$+[NII] emission is covered by the J-PLUS narrow-band filter $F660$. We explore three different methods to extract the H$\\alpha$ + [NII] flux from J-PLUS photometric data: a combination of a broad-band and a narrow-band filter ($r'$ and $F660$), two broad-band and a narrow-band one ($r'$, $i'$ and $F660$), and a SED-fitting based method using 8 photometric points. To test these methodologies, we simulated J-PLUS data from a sample of 7511 SDSS spectra with measured H$\\alpha$ flux. Based on the same sample, we derive two empirical relations to correct the derived H$\\alpha$+[NII] flux from dust extinction and [NII] contamination. We find that the only unbiased method is the SED fitting based one. The combination of two filters underestimates the measurements of the H$\\alpha$ + [NII] flux by a 28%, while the th...

  19. A large narrow band H$\\alpha$ survey at $z\\sim0.2$: the bright end of the luminosity function, cosmic variance and clustering across cosmic time

    Stroe, Andra

    2015-01-01

    We carried out the largest ($>3.5\\times10^5$ Mpc$^3$, 26 deg$^2$) H$\\alpha$ narrow band survey to date at $z\\sim0.2$ in the SA22, W2 and XMMLSS extragalactic fields. Our survey covers a large enough volume to overcome cosmic variance and to sample bright and rare H$\\alpha$ emitters up to an observed luminosity of $\\sim10^{42.4}$ erg s$^{-1}$, equivalent to $\\sim11 M_\\odot$ yr$^{-1}$. Using our sample of $220$ sources brighter than $>10^{41.4}$ erg s$^{-1}$ ($>1 M_\\odot$ yr$^{-1}$), we derive H$\\alpha$ luminosity functions, which are well described by a Schechter function with $\\phi^* = 10^{-2.85\\pm0.03}$ Mpc$^{-3}$ and $L^*_{H\\alpha} = 10^{41.71\\pm0.02}$ erg s$^{-1}$ (with a fixed faint end slope $\\alpha=-1.35$). We find that surveys probing smaller volumes ($\\sim3\\times10^4$ Mpc$^3$) are heavily affected by cosmic variance, which can lead to errors of over $100$ per cent in the characteristic density and luminosity of the H$\\alpha$ luminosity function. We derive a star formation rate density of $\\rho_\\mathrm...

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

    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 ...

  1. A Deeper Look at Faint H$\\alpha$ Emission in Nearby Dwarf Galaxies

    Lee, Janice C; McDonald, Michael; Hilbert, Bryan

    2016-01-01

    We present deep H$\\alpha$ imaging of three nearby dwarf galaxies, carefully selected to optimize observations with the Maryland-Magellan Tunable Filter (MMTF) on the Magellan 6.5m telescope. An effective bandpass of $\\sim$13\\AA\\ is used, and the images reach 3$\\sigma$ flux limits of $\\sim$8$\\times10^{-18}$ ergs s$^{-1}$ cm$^{-2}$, which is about an order of magnitude lower than standard narrowband observations obtained by the most recent generation of local H$\\alpha$ galaxy surveys. The observations were originally motivated by the finding that the H$\\alpha$/FUV flux ratio of galaxies systematically declines as global galactic properties such as the star formation rate and stellar mass decrease. The three dwarf galaxies selected for study have star formation rates, that when calculated from their H$\\alpha$ luminosities using standard conversion recipes, are $\\sim$50\\% of those based on the FUV. Follow-up studies of many of the potential causes for the trends in the H$\\alpha$/FUV flux ratio have been performed...

  2. Supernova-Driven Outflows in NGC 7552: A Comparison of H-alpha and UV Tracers

    Wood, Corey M; Calzetti, Daniela; Leitherer, Claus; Chisholm, John; Gallagher, John S

    2015-01-01

    We investigate the supernova-driven galactic wind of the barred spiral galaxy NGC 7552, using both ground-based optical nebular emission lines and far-ultraviolet absorption lines measured with the Hubble Space Telescope Cosmic Origins Spectrograph. We detect broad (~300 km/s) blueshifted (-40 km/s) optical emission lines associated with the galaxy's kpc-scale star-forming ring. The broad line kinematics and diagnostic line ratios suggest that the H-alpha emission comes from clouds of high density gas entrained in a turbulent outflow. We compare the H-alpha emission line profile to the UV absorption line profile measured along a coincident sight line and find significant differences. The maximum blueshift of the H-alpha-emitting gas is ~290 km/s, whereas the UV line profile extends to blueshifts upwards of 1000 km/s. The mass outflow rate estimated from the UV is roughly nine times greater than that estimated from H-alpha. We argue that the H-alpha emission traces a cluster-scale outflow of dense, low velocit...

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

    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...

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

    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...

  5. A Model for the Scattered Light Contribution and Polarization of the Diffuse $H\\alpha$ Galactic Background

    Wood, K; Wood, Kenneth; Reynolds, Ron

    1999-01-01

    We present Monte Carlo simulations of the Diffuse H$\\alpha$ Galactic Background. Our models comprise direct and multiply scattered H$\\alpha$ radiation from the kpc scaleheight Warm Ionized Medium and midplane H II regions. The scattering is off dust that is assumed to be well mixed with the gas, with an axisymmetric density distribution taken from the literature. The results of our simulations are all-sky H$\\alpha$ images that enable us to separate out the contributions of direct and scattered radiation. We also determine how far the model H$\\alpha$ photons have traveled, i.e., how far we see into the Galaxy at H$\\alpha$. Our models reproduce the overall characteristics of the observed H$\\alpha$ background and predict the scattered H$\\alpha$ intensity at high latitudes is in the range 5% to 20% of the total intensity, in agreement with estimations based on [S II]/H$\\alpha$ and [O III]/H$\\alpha$ line ratio measurements. The polarization arising from dust scattering of H$\\alpha$ from midplane H II regions is pr...

  6. H-alpha Imaging Survey of Low-Redshift Cluster Dwarf Galaxies

    Barkhouse, Wayne; Kalawila, Sandanuwan; Rude, Cody; Sultanova, Madina; Archer, Haylee Nichole; Foote, Gregory

    2016-01-01

    We describe our on-going H-alpha imaging survey to measure the star formation activity of dwarf galaxies selected from a sample of low-redshift (0.02 environment can be quantified using radial-dependent measures of the star formation rate within individual clusters, and by comparing clusters within our sample on a cluster-to-cluster basis. Comparison of our H-alpha measurements to CFHT u-band imaging data of our cluster sample, permits us to explore the correlation between the UV continuum and H-alpha emission of the dwarf galaxy population. The goal of our survey is to further understand the mechanism that is responsible for the enhancement/quenching of star formation as dwarf galaxies fall into the galaxy cluster environment.

  7. Mapping the Galactic Free-Free Foreground via Interstellar H-Alpha Emission

    Reynolds, R J

    2000-01-01

    Recently completed H-Alpha surveys of large portions of the sky can be used to create maps of the free-free intensity distribution at high Galactic latitude that are independent of the spectral fits to the CMB data. This provides an opportunity to test the accuracy of the spectral fitting procedures and to search for other sources of Galactic forground contamination that could be confused spectrally with the free-free, such as spinning dust grains. The Wisconsin H-Alpha Mapper (WHAM) survey has sampled the sky north of declination -30 deg at about one degree angular resolution and has revealed that, except for a few isolated regions of enhanced emission, \\Delta T_{ff} (30 GHz) < 30 micro-K at Galactic latitudes near 15 deg, decreasing to \\Delta T_{ff} (30 GHz) < 4 mircro-K at latitudes above 50 deg. Also in progress are H-Alpha surveys that sample the sky at higher angular resolution.

  8. The Wisconsin H-Alpha Mapper Northern Sky Survey of Galactic Ionized Hydrogen

    Madsen, G J; Reynolds, R J

    2001-01-01

    The Wisconsin H-Alpha Mapper (WHAM) has completed a one-degree resolution, velocity-resolved northern sky survey of H-alpha emission from our Galaxy. The unprecedented sensitivity of the instrument and accurate spectral subtraction of atmospheric features allow us to detect Galactic features as faint as 0.1 Rayleighs (EM ~ 0.25 cm^{-6} pc). This survey allows a direct comparison of the ionized and neutral components of the ISM on a global scale for the first time. All-sky maps of H-alpha emission in select velocity bands highlight the rich kinematic structure of the Galaxy's ionized gas. The full set of data from the WHAM survey is now available at http://www.astro.wisc.edu/wham/. (abridged)

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

    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.

  10. Predicting the Redshift 2 H-Alpha Luminosity Function Using [OIII] Emission Line Galaxies

    Mehta, Vihang; Scarlata, Claudia; Colbert, James W.; Dai, Y. S.; Dressler, Alan; Henry, Alaina; Malkan, Matt; Rafelski, Marc; Siana, Brian; Teplitz, Harry I.; Bagley, Micaela; Beck, Melanie; Ross, Nathaniel R.; Rutkowski, Michael; Wang, Yun

    2015-01-01

    Upcoming space-based surveys such as Euclid and WFIRST-AFTA plan to measure Baryonic Acoustic Oscillations (BAOs) in order to study dark energy. These surveys will use IR slitless grism spectroscopy to measure redshifts of a large number of galaxies over a significant redshift range. In this paper, we use the WFC3 Infrared Spectroscopic Parallel Survey (WISP) to estimate the expected number of H-alpha emitters observable by these future surveys. WISP is an ongoing Hubble Space Telescope slitless spectroscopic survey, covering the 0.8 - 1.65 micrometers wavelength range and allowing the detection of H-alpha emitters up to z approximately equal to 1.5 and [OIII] emitters to z approximately equal to 2.3. We derive the H-alpha-[OIII] bivariate line luminosity function for WISP galaxies at z approximately equal to 1 using a maximum likelihood estimator that properly accounts for uncertainties in line luminosity measurement, and demonstrate how it can be used to derive the H-alpha luminosity function from exclusively fitting [OIII] data. Using the z approximately equal to 2 [OIII] line luminosity function, and assuming that the relation between H-alpha and [OIII] luminosity does not change significantly over the redshift range, we predict the H-alpha number counts at z approximately equal to 2 - the upper end of the redshift range of interest for the future surveys. For the redshift range 0.7 less than z less than 2, we expect approximately 3000 galaxies per sq deg for a flux limit of 3 x 10(exp -16) ergs per sec per sq cm (the proposed depth of Euclid galaxy redshift survey) and approximately 20,000 galaxies per sq deg for a flux limit of approximately 10(exp -16) ergs per sec per sq cm (the baseline depth of WFIRST galaxy redshift survey).

  11. Narrow H-alpha emission profiles in tokamaks: molecular origin and observational effects

    The narrow hydrogen Balmer alpha profiles observed in tokamaks are explained in terms of the slow (approx. 0.3 eV) and fast (2 to 6 eV) excited atoms formed by dissociation of molecular hydrogen at the plasma edge. Extra widening of the spectrum in the wings can be explaind by Zeeman split H-alpha that is reflected from the vacuum vessel. This interpretation is consistent with available high-resolution data. The use of H-alpha as a diagnostic is discussed briefly

  12. H-alpha Survey of the Local Volume: Isolated Southern Galaxies

    Kaisin, S S; Knyazev, A Yu; Karachentsev, I D

    2007-01-01

    We present our H-alpha observations of 11 isolated southern galaxies: SDIG, PGC 51659, E 222-010, E 272-025, E 137-018, IC 4662, Sag DIG, IC 5052, IC 5152, UGCA 438, and E149-003, with distances from 1 to 7 Mpc. We have determined the total H-alpha fluxes from these galaxies. The star formation rates in these galaxies range from 10^{-1} (IC 4662) to 10^{-4}_{\\odot}/yr (SDIG) and the gas depletion time at the observed star formation rates lies within the range from 1/6 to 24 Hubble times H_0^{-1} .

  13. H-alpha Survey of the Local Volume: Isolated Southern Galaxies

    Kaisin, S. S.; Kasparova, A. V.; Knyazev, A. Yu.; Karachentsev, I. D.

    2007-01-01

    We present our H-alpha observations of 11 isolated southern galaxies: SDIG, PGC 51659, E 222-010, E 272-025, E 137-018, IC 4662, Sag DIG, IC 5052, IC 5152, UGCA 438, and E149-003, with distances from 1 to 7 Mpc. We have determined the total H-alpha fluxes from these galaxies. The star formation rates in these galaxies range from 10^{-1} (IC 4662) to 10^{-4}_{\\odot}/yr (SDIG) and the gas depletion time at the observed star formation rates lies within the range from 1/6 to 24 Hubble times H_0^{...

  14. Observational and theoretical constraints for an H$\\alpha$-halo around the Crab Nebula

    Tziamtzis, A.; M. Schirmer; Lundqvist, P.; Sollerman, J

    2009-01-01

    We searched for a fast moving H$\\alpha$ shell around the Crab nebula. Such a shell could account for this supernova remnant's missing mass, and carry enough kinetic energy to make SN 1054 a normal Type II event. Deep H$\\alpha$ images were obtained with WFI at the 2.2m MPG/ESO telescope and with MOSCA at the 2.56m NOT. The data are compared with theoretical expectations derived from shell models with ballistic gas motion, constant temperature, constant degree of ionisation and a power law for ...

  15. Evidence for ubiquitous high-equivalent-width nebular emission in z ∼ 7 galaxies: toward a clean measurement of the specific star-formation rate using a sample of bright, magnified galaxies

    Smit, R.; Bouwens, R. J.; Labbé, I. [Leiden Observatory, Leiden University, NL-2300 RA Leiden (Netherlands); Zheng, W.; Lemze, D.; Ford, H. [Department of Physics and Astronomy, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Bradley, L.; Coe, D.; Postman, M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21208 (United States); Donahue, M. [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Moustakas, J. [Siena College, 515 Loudon Road, Loudonville, NY 12211 (United States); Umetsu, K. [Institute of Astronomy and Astrophysics, Academia Sinica, P. O. Box 23-141, Taipei 10617, Taiwan (China); Zitrin, A.; Bartelmann, M. [Institut fur Theoretische Astrophysik, ZAH, Albert-Ueberle-Straß e 2, 69120 Heidelberg (Germany); Gonzalez, V. [Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States); Benítez, N.; Jimenez-Teja, Y. [Instituto de Astrofisica de Andalucia (CSIC), C/Camino Bajo de Huetor 24, Granada 18008 (Spain); Broadhurst, T. [Department of Theoretical Physics, University of the Basque Country, P. O. Box 644, 48080 Bilbao (Spain); Grillo, C. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Infante, L. [Departamento de Astronoia y Astrofisica, Pontificia Universidad Catolica de Chile, V. Mackenna 4860, Santiago 22 (Chile); and others

    2014-03-20

    Growing observational evidence indicates that nebular line emission has a significant impact on the rest-frame optical fluxes of z ∼ 5-7 galaxies. This line emission makes z ∼ 5-7 galaxies appear more massive, with lower specific star-formation rates (sSFRs). However, corrections for this line emission have been difficult to perform reliably because of huge uncertainties on the strength of such emission at z ≳ 5.5. In this paper, we present the most direct observational evidence thus far for ubiquitous high-equivalent-width (EW) [O III] + Hβ line emission in Lyman-break galaxies at z ∼ 7, and we present a strategy for an improved measurement of the sSFR at z ∼ 7. We accomplish this through the selection of bright galaxies in the narrow redshift window z ∼ 6.6-7.0 where the Spitzer/Infrared Array Camera (IRAC) 4.5 μm flux provides a clean measurement of the stellar continuum light, in contrast with the 3.6 μm flux, which is contaminated by the prominent [O III] + Hβ lines. To ensure a high signal-to-noise ratio for our IRAC flux measurements, we consider only the brightest (H {sub 160} < 26 mag) magnified galaxies we have identified behind galaxy clusters. It is remarkable that the mean rest-frame optical color for our bright seven-source sample is very blue, [3.6]-[4.5] = –0.9 ± 0.3. Such blue colors cannot be explained by the stellar continuum light and require that the rest-frame EW of [O III] + Hβ is greater than 637 Å for the average source. The four bluest sources from our seven-source sample require an even more extreme EW of 1582 Å. We can also set a robust lower limit of ≳ 4 Gyr{sup –1} on the sSFR of our sample based on the mean spectral energy distribution.

  16. Interstellar H-Alpha Line Profiles toward HD 93521 and the Lockman Window

    Hausen, N R; Haffner, L M; Tufte, S L

    2001-01-01

    We have used the Wisconsin H-Alpha Mapper (WHAM) facility to measure the interstellar H-Alpha emission toward the high Galactic latitude O star HD 93521 (l = 183.1, b = +62.2). Three emission components were detected having radial velocities of -10 km s^{-1}, -51 km s^{-1}, and -90 km s^{-1} with respect to the local standard of rest (LSR) and H-Alpha intensities of 0.20 R, 0.15 R, and 0.023 R, respectively, corresponding to emission measures of 0.55 cm^{-6} pc, 0.42 cm^{-6} pc, and 0.06 cm^{-6} pc. We have also detected an H-Alpha emission component at -1 km s^{-1} (LSR) with an intensity of 0.20 R (0.55 cm^{-6} pc) toward the direction l = 148.5, b = +53.0, which lies in the region of exceptionally low H I column density known as the Lockman Window. In addition, we studied the direction l = 163.5, b = +53.5. Upper limits on the possible intensity of Galactic emission toward this direction are 0.11 R at the LSR and 0.06 R at -50 km s^{-1}. We also detected and characterized twelve faint (~0.03-0.15 R), unide...

  17. The Gaseous ISM Observations with the Wisconsin $H-\\alpha$ Mapper (WHAM)

    Reynolds, R J; Tufte, S L

    1998-01-01

    The Wisconsin H-Alpha Mapper (WHAM) is a new facility dedicated to the study of faint optical emission lines from diffuse interstellar gas. During its first 18 months of operation, WHAM carried out a survey of the interstellar H-alpha emission associated with the warm, ionized component of the interstellar medium. The observations consisted of 37,000 spectra obtained with a one degree diameter beam on a 0.98 X 0.85 degree grid (lxb), covering the sky above declination -30 degrees. This survey provides for the first time a detailed picture of the distribution and kinematics of the diffuse ionized hydrogen through the H-alpha line comparable to surveys of the neutral hydrogen obtained through the 21 cm line. Preliminary reduction of the data from selected portions of the sky reveal that the interstellar H II has a complex distribution, with long filaments and loop-like structures extending to high Galactic latitudes and superposed on a more diffuse background. Apart from the H-alpha sky survey, WHAM has also de...

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

    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...

  19. H$_\\alpha$-activity and ages for stars in the SARG survey

    Sissa, E; Desidera, S; Fiorenzano, A F Martinez; Bonfanti, A; Carolo, E; Vassallo, D; Claudi, R U; Endl, M; Cosentino, R

    2016-01-01

    Stellar activity influences radial velocity (RV) measurements and can also mimic the presence of orbiting planets. As part of the search for planets around the components of wide binaries performed with the SARG High Resolution Spectrograph at the TNG, it was discovered that HD 200466A shows strong variation in RV that is well correlated with the activity index based on H$_\\alpha$. We used SARG to study the H$_\\alpha$ line variations in each component of the binaries and a few bright stars to test the capability of the H$_\\alpha$ index of revealing the rotation period or activity cycle. We also analysed the relations between the average activity level and other physical properties of the stars. We finally tried to reveal signals in the RVs that are due to the activity. At least in some cases the variation in the observed RVs is due to the stellar activity. We confirm that H$_\\alpha$ can be used as an activity indicator for solar-type stars and as an age indicator for stars younger than 1.5 Gyr.

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

    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...

  1. Canes Venatici I cloud of galaxies seen in the H-alpha line

    Kaisin, S S

    2007-01-01

    We present results of H-alpha imaging for 42 galaxies in the nearby low-density cloud Canes Venatici I populated mainly by late-type objects. Estimates of the H-alpha flux and integrated star formation rate (SFR) are now available for all 78 known members of this scattered system, spanning a large range in luminosity, surface brightness, HI content and SFR. Distributions of the CVnI galaxies versus their SFR, blue absolute magnitude and total hydrogen mass are given in comparison with those for a population of the nearby virialized group around M81. We found no essential correlation between star formation activity in a galaxy and its density environment. A bulk of CVnI galaxies had enough time to generate their baryon mass with the observed SFR. Most of them possess also a supply of gas sufficient to maintain their observed SFR's during the next Hubble time.

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

    Reynolds, R. J.; Magee, K.; Roesler, F. L.; Scherb, F.; Harlander, J.

    1986-01-01

    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.

  3. Properties of white light flares. I - Association with H-alpha flares and sudden frequency deviations.

    Mcintosh, P. S.; Donnelly, R. F.

    1972-01-01

    All four large EUV bursts for which there were available concurrent white light observations of at least fair quality, were detected as white light flares. The rise times and maxima of the white light emissions coincided with rise times and maxima of the EUV bursts. The frequency of strong EUV bursts suggests that white light flares may occur at the rate of five or six per year near sunspot maximum. All of the white light flare areas coincided with intense bright areas of the H-alpha flares. These small areas appeared to be sources of high velocity ejecta in H-alpha. The white light flares occurred as several knots or patches of 2 to 15 arc-sec diameter, with bright cores perhaps less than 2 arc-sec diameter (1500 km). They preferred the outer penumbral borders of strong sunspots within 10 arc-sec of a longitudinal neutral line in the magnetic field.

  4. WHAM Observations of H-alpha from High-Velocity Clouds Are They Galactic or Extragalactic?

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

    2002-01-01

    It has been suggested that high velocity clouds may be distributed throughout the Local Group and are therefore not in general associated with the Milky Way galaxy. With the aim of testing this hypothesis, we have made observations in the H-alpha line of high velocity clouds selected as the most likely candidates for being at larger than average distances. We have found H-alpha emission from 4 out of 5 of the observed clouds, suggesting that the clouds under study are being illuminated by a Lyman continuum flux greater than that of the metagalactic ionizing radiation. Therefore, it appears likely that these clouds are in the Galactic halo and not distributed throughout the Local Group.

  5. Using H-alpha as a Tracer of the Emission Region of LS I +61 303

    McSwain, M Virginia

    2011-01-01

    The gamma-ray binary LS I +61 303 is one of the brightest Fermi sources, with orbitally modulated emission across the electromagnetic spectrum. Here we present H-alpha spectra of LS I +61 303 that exhibit a dramatic emission burst shortly before apastron, observed as a redshifted shoulder in the line profile. A correlated burst in radio, X-ray, and GeV emission is observed at the same orbital phase. We interpret the source of the emission as a compact pulsar wind nebula that forms when a tidal mass stream from the Be circumstellar disk interacts with the relativistic pulsar wind. The H-alpha emission offers an important probe of the high energy emission morphology in this system.

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

    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....

  7. A Search for "Dwarf" Seyfert Nuclei; 4, Nuclei with Broad H-$\\alpha$ Emission

    Ho, L C; Sargent, W L W; Peng, C Y; Ho, Luis C.; Filippenko, Alexei V.; Sargent, Wallace L. W.; Peng, Chien Y.

    1997-01-01

    We present the results of an optical spectroscopic survey designed to search for low-luminosity, "dwarf" Seyfert nuclei in a magnitude-limited sample of 486 bright, northern galaxies. Moderate-resolution spectra of exceptionally high quality were obtained in part to detect broad H-alpha emission, similar in character to, but much weaker than, the broad permitted lines that define type 1 Seyfert nuclei. One of the primary goals of the survey is to better quantify the faint end of the luminosity function of active galactic nuclei. This paper describes the subset of nuclei showing definite or probable evidence of broad H-alpha emission. We outline the procedures for determining the presence of this elusive spectral feature, steps for its quantitative measurement, and the associated systematic errors. Of the 211 emission-line galaxies classified as having Seyfert or LINER nuclei in our survey, the broad H-alpha line was detected with confidence in 34 objects, and with less certainty in another 12. Most of the det...

  8. The Lyman alpha reference sample. VII. Spatially resolved H$\\alpha$ kinematics

    Herenz, Edmund Christian; Orlitova, Ivana; Hayes, Matthew; Östlin, Göran; Cannon, John M; Roth, Martin M; Bik, Arjan; Pardy, Stephen; Otí-Floranes, Héctor; Mas-Hesse, J Miguel; Adamo, Angela; Atek, Hakim; Duval, Florent; Guaita, Lucia; Kunth, Daniel; Laursen, Peter; Melinder, Jens; Puschnig, Johannes; Rivera-Thorsen, Thøger E; Schaerer, Daniel; Verhamme, Anne

    2015-01-01

    We present integral field spectroscopic observations with the Potsdam Multi Aperture Spectrophotometer of all 14 galaxies in the $z\\sim 0.1$ Lyman Alpha Reference Sample (LARS). We produce 2D line of sight velocity maps and velocity dispersion maps from the Balmer $\\alpha$ (H$\\alpha$) emission in our data cubes. These maps trace the spectral and spatial properties of the LARS galaxies' intrinsic Ly$\\alpha$ radiation field. We show our kinematic maps spatially registered onto the Hubble Space Telescope H$\\alpha$ and Lyman $\\alpha$ (Ly$\\alpha$) images. Only for individual galaxies a causal connection between spatially resolved H$\\alpha$ kinematics and Ly$\\alpha$ photometry can be conjectured. However, no general trend can be established for the whole sample. Furthermore, we compute non-parametric global kinematical statistics -- intrinsic velocity dispersion $\\sigma_0$, shearing velocity $v_\\mathrm{shear}$, and the $v_\\mathrm{shear}/\\sigma_0$ ratio -- from our kinematic maps. In general LARS galaxies are charac...

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

    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...

  10. On the H$\\alpha$ emission from the $\\beta$ Cephei system

    Schnerr, R S; Oudmaijer, R D; Telting, J H

    2006-01-01

    Be stars, which are characterised by intermittent emission in their hydrogen lines, are known to be fast rotators. This fast rotation is a requirement for the formation of a Keplerian disk, which in turn gives rise to the emission. However, the pulsating, magnetic B1IV star $\\beta$ Cephei is a very slow rotator that still shows H$\\alpha$ emission episodes like in other Be stars, contradicting current theories. We investigate the hypothesis that the H$\\alpha$ emission stems from the spectroscopically unresolved companion of $\\beta$ Cep. Spectra of the two unresolved components have been separated in the 6350-6850\\AA range with spectro-astrometric techniques, using 11 longslit spectra obtained with ALFOSC at the Nordic Optical Telescope, La Palma. We find that the H$\\alpha$ emission is not related to the primary in $\\beta$ Cep, but is due to its 3.4 magnitudes fainter companion. This companion has been resolved by speckle techniques, but it remains unresolved by traditional spectroscopy. The emission extends fr...

  11. Observational and theoretical constraints for an H$\\alpha$-halo around the Crab Nebula

    Tziamtzis, A; Lundqvist, P; Sollerman, J

    2009-01-01

    We searched for a fast moving H$\\alpha$ shell around the Crab nebula. Such a shell could account for this supernova remnant's missing mass, and carry enough kinetic energy to make SN 1054 a normal Type II event. Deep H$\\alpha$ images were obtained with WFI at the 2.2m MPG/ESO telescope and with MOSCA at the 2.56m NOT. The data are compared with theoretical expectations derived from shell models with ballistic gas motion, constant temperature, constant degree of ionisation and a power law for the density profile. We reach a surface brightness limit of $5\\times10^{-8} ergs s^{-1} cm^{-2} sr^{-1}$. A halo is detected, but at a much higher surface brightness than our models of recombination emission and dust scattering predict. Only collisional excitation of Ly$\\beta$ with partial de-excitation to H$\\alpha$ could explain such amplitudes. We show that the halo seen is due to PSF scattering and thus not related to a real shell. We also investigated the feasibility of a spectroscopic detection of high-velocity H$\\al...

  12. Spatial Correlation Between Dust and H$\\alpha$ Emission in Dwarf Irregular Galaxies

    Jimmy,; Saintonge, Amélie; Accurso, Gioacchino; Brough, Sarah; Oliva-Altamirano, Paola; Salmon, Brett; Forrest, Ben

    2016-01-01

    Using a sample of dwarf irregular galaxies selected from the ALFALFA blind HI-survey and observed using the VIMOS IFU, we investigate the relationship between H$\\alpha$ emission and Balmer optical depth ($\\tau_{\\text{b}}$). We find a positive correlation between H$\\alpha$ luminosity surface density and Balmer optical depth in 8 of 11 at $\\geq$ 0.8$\\sigma$ significance (6 of 11 at $\\geq$ 1.0$\\sigma$) galaxies. Our spaxels have physical scales ranging from 30 to 80 pc, demonstrating that the correlation between these two variables continues to hold down to spatial scales as low as 30 pc. Using the Spearman's rank correlation coefficient to test for correlation between $\\Sigma_{\\text{H}\\alpha}$ and $\\tau_{\\text{b}}$ in all the galaxies combined, we find $\\rho = 0.39$, indicating a positive correlation at 4$\\sigma$ significance. Our low stellar-mass galaxy results are in agreement with observations of emission line regions in larger spiral galaxies, indicating that this relationship is independent of the size of ...

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

    Frew, David J; Bojicic, I S

    2016-01-01

    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...

  14. Star-formation properties of Hickson Compact Groups based on deep H{\\alpha} imaging

    Eigenthaler, Paul; Verdugo, Miguel; Ziegler, Bodo

    2015-01-01

    We present deep H{\\alpha} imaging of seven Hickson Compact Groups (HCGs) using the 4.1m Southern Astrophysics Research (SOAR) Telescope. The high spatial resolution of the observations allow us to study both the integrated star-formation properties of the main galaxies as well as the 2D distribution of star-forming knots in the faint tidal arms that form during interactions between the individual galaxies. We derive star-formation rates and stellar masses for group members and discuss their position relative to the main sequence of star-forming galaxies. Despite the existence of tidal features within the galaxy groups, we do not find any indication for enhanced star-formation in the selected sample of HCGs. We study azimuthally averaged H{\\alpha} profiles of the galaxy disks and compare them with the g' and r' surface-brightness profiles. We do not find any truncated galaxy disks but reveal that more massive galaxies show a higher light concentration in H{\\alpha} than less massive ones. We also see that galax...

  15. Is the Broad-Line Region Clumped or Smooth? Constraints from the H alpha Profile in NGC 4395, the Least Luminous Seyfert 1 Galaxy

    Laor, A; Ho, L C; Filippenko, A V; Laor, Ari; Barth, Aaron J.; Ho, Luis C.; Filippenko, Alexei V.

    2005-01-01

    The origin and configuration of the gas which emits broad lines in Type I active galactic nuclei is not established yet. The lack of small-scale structure in the broad emission-line profiles is consistent with a smooth gas flow, or a clumped flow with many small clouds. An attractive possibility for the origin of many small clouds is the atmospheres of bloated stars, an origin which also provides a natural mechanism for the cloud confinement. Earlier studies of the broad-line profiles have already put strong lower limits on the minimum number of such stars, but these limits are sensitive to the assumed width of the lines produced by each cloud. Here we revisit this problem using high-resolution Keck spectra of the H alpha line in NGC 4395, which has the smallest known broad-line region (~10^14 cm). Only a handful of the required bloated stars (each having r~10^14 cm) could fit into the broad-line region of NGC 4395, yet the observed smoothness of the H alpha line implies a lower limit of ~10^4-10^5 on the num...

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

    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...

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

    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.

  18. Standard Stars for the BYU H-alpha Photometric System (Abstract)

    Joner, M.; Hintz, E.

    2015-12-01

    (Abstract only) We present primary standard stars for the BYU H-alpha photometric system. This system is similar to the H-beta photometric system that is often used with the intermediate band uvby system. Both systems use the difference between magnitudes measured in a wide (15-20-nm) and narrow (3-nm) bandpass centered on one of the strong Balmer lines of hydrogen to establish a color index. Line indices formed in this manner are independent of atmospheric extinction and interstellar reddening. These indices provide intrinsic measures of effective temperature for stars with spectral types between B and G. The present primary standard stars for the BYU system as established using spectroscopic observations that cover the region between the H-alpha and H-beta lines. The indices were formed using synthetic photometry reductions to convolve ideal filter profiles with the observed spectra. The number of observations per star is generally in excess of 25. Some stars have been observed more than 100 times over a period of 7 years. The typical error per observation for these stars is on the order of 1-3 mmag. In addition to the standard field stars, we present H-alpha and H-beta observations of individual stars that are members of selected open clusters. These include the Hyades, Pleiades, Coma, and NGC 752 clusters. Additional stars that exhibit varying degrees of hydrogen emission are easily distinguished in a plot of the alpha-beta plane. We have found that candidates for emission line objects, high mass x-ray binaries, and young stellar objects are readily identified in our alpha-beta plots. We acknowledge continued support from the BYU College of Physical and Mathematical Sciences as well as support from NSF Grant AST #0618209. We also thank the Dominion Astrophysical Observatory for continued allocation of robotic observing time for spectroscopy on the 1.2-m telescope.

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

    Becker, Robert H.; White, Richard L.

    1988-01-01

    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.

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

    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

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

    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...

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

    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 ...

  3. Amalgam width of matroids

    Mach, Lukas; Toufar, Tomas

    2013-01-01

    We introduce a new matroid width parameter based on the operation of matroid amalgamation, which we call amalgam-width. The parameter is linearly related to branch-width on finitely representable matroids (which is not possible for branch-width). In particular, any property expressible in the monadic second order logic can be decided in linear time for matroids with bounded amalgam-width. We also prove that the Tutte polynomial can be computed in polynomial time for matroids with bounded amal...

  4. Modelling the orientation of accretion disks in quasars using H-alpha emission

    Down, E J; Sivia, D S; Baker, J C

    2009-01-01

    Infrared spectroscopy of the H-alpha emission lines of a sub-sample of 19 high-redshift (0.8 < z < 2.3) Molonglo quasars, selected at 408 MHz, is presented. These emission lines are fitted with composite models of broad and narrow emission, which include combinations of classical broad-line regions of fast-moving gas clouds lying outside the quasar nucleus, and/or a theoretical model of emission from an optically-thick, flattened, rotating accretion disk. All bar one of the nineteen sources are found to have emission consistent with the presence of an optically-emitting accretion disk, with the exception appearing to display complex emission including at least three broad components. Ten of the quasars have strong Bayesian evidence for broad-line emission arising from an accretion disk together with a standard broad-line region, selected in preference to a model with two simple broad lines. Thus the best explanation for the complexity required to fit the broad H-alpha lines in this sample is optical emi...

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

    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...

  6. Boxy H$\\alpha$ Emission Profiles in Star-Forming Galaxies

    Chen, Yan-Mei; Tremonti, Christy A; Shi, Yong; Jin, Yi-Fei

    2016-01-01

    We assemble a sample of disk star-forming galaxies from the Sloan Digital Sky Survey Data Release 7, studying the structure of H$\\alpha$ emission lines, finding a large fraction of this sample contains boxy H$\\alpha$ line profiles. This fraction depends on galaxy physical and geometric parameters in the following way: (1) it increases monotonically with star formation rate per unit area ($\\Sigma_{\\rm SFR}$), and stellar mass ($M_*$), with the trend being much stronger with $M_*$, from $\\sim$0% at $M_*=10^{10}M_{\\odot}$ to about 50% at $M_*=10^{11}M_\\odot$; (2) the fraction is much smaller in face-on systems than in edge-on systems. It increases with galaxy inclination ($i$) while $i < 60\\,^{\\circ}$ and is roughly a constant of 25% beyond this range; (3) for the sources which can be modeled well with two velocity components, blueshifted and redshifted from the systemic velocity, these is a positive correlation between the velocity difference of these two components and the stellar mass, with a slope similar...

  7. Infrared studies of pre-main-sequence intermediate-mass stars - LkH-Alpha 198

    Natta, Antonella; Palla, Francesco; Butner, Harold M.; Evans, Neal J., II; Harvey, Paul M.

    1992-01-01

    The paper presents FIR scans of LkH-Alpha 198 at 50 and 100 microns along several directions; the observations reveal an extended, roughly spherical source diameter of 33 arcsec, or 20,000 AU, at 100 microns and not more than 10 arcsec, or 15,000 AU, at 50 microns. A luminosity of 250 solar luminosities at a distance of 600 pc is estimated on the basis of a comparison of the observed properties at optical, IR, and millimeter wavelengths with the predictions of radiation transfer models. The optical depth at 100 microns is 0.004-0.006, implying a mass of about 2 solar masses with a radius of 10,000 AU. It is argued that the inner radius of the dusty envelope is rather small, less than about 300 AU (0.5 arcsec), and it may be as small as the dust destruction front: in LkH-Alpha 198 there is no evidence of a large region devoid of grains.

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

    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 ...

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

    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.

  10. The Galactic Halo Ionizing Field and $H-\\alpha$ Distances to HVCs

    Bland-Hawthorn, J

    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 explained by photoionization due to hot, young stars. Our model requires that the mean Lyman-limit opacity perpendicular to the disk is tau close to unity. Within the context of this model, it now becomes possible to determine distances to high velocity clouds, and the 3D orientation of the Magellanic Stream. Here, we discuss complications of the model (e.g., porosity, topology), future tests, ongoing improvements, and the importance of H-alpha limb brightening from surface ionization. More speculatively, we propose a direct experiment for ...

  11. A Survey for H-alpha Emission from Late L dwarfs and T dwarfs

    Pineda, J Sebastian; Kirkpatrick, J Davy; Cotter, Garret; Kao, Melodie M; Mooley, Kunal

    2016-01-01

    Recently, studies of brown dwarfs have demonstrated that they possess strong magnetic fields and have the potential to produce radio and optical auroral emissions powered by magnetospheric currents. This emission provides the only window on magnetic fields in the coolest brown dwarfs and identifying additional benchmark objects is key to constraining dynamo theory in this regime. To this end, we conducted a new red optical (6300 - 9700 Angstrom) survey with the Keck telescopes looking for H-alpha emission from a sample of late L dwarfs and T dwarfs. Our survey gathered optical spectra for 29 targets, 18 of which did not have previous optical spectra in the literature, greatly expanding the number of moderate resolution (R~2000) spectra available at these spectral types. Combining our sample with previous surveys, we confirm an H-alpha detection rate of 9.2 (+3.5/-2.1) % for L and T dwarfs in the optical spectral range of L4 - T8. This detection rate is consistent with the recently measured detection rate for ...

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

    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...

  13. Limits on Lyman Continuum escape from z=2.2 H-alpha emitting galaxies

    Sandberg, A; Melinder, J; Bik, A; Guaita, L

    2015-01-01

    The leakage of Lyman continuum photons from star forming galaxies is an elusive parameter. When observed, it provides a wealth of information on star formation in galaxies and the geometry of the interstellar medium, and puts constraints on the role of star forming galaxies in the reionization of the universe. H-alpha-selected galaxies at z~2 trace the highest star formation population at the peak of cosmic star formation history, providing a base for directly measuring Lyman continuum escape. Here we present this method, and highlight its benefits as well as caveats. We also use the method on 10 H-alpha emitters in the Chandra Deep Field South at z=2.2, also imaged with the Hubble Space Telescope in the ultraviolet. We find no individual Lyman continuum detections, and our stack puts a 5 sigma upper limit on the average absolute escape fraction of <24%, consistent with similar studies. With future planned observations, the sample sizes would rapidly increase and the method presented here would provide ver...

  14. The H$\\alpha$ surface brightness $-$ radius plane as a diagnostic tool for photoionized nebulae

    Frew, David J; Parker, Quentin A

    2016-01-01

    The H$\\alpha$ surface brightness $-$ radius ($S-r$) relation is a robust distance indicator for planetary nebulae (PNe), further enhanced by different populations of PNe having distinct loci in $S-r$ space. Other types of photoionized nebulae also plot in quite distinct regions in the $S-r$ plane, allowing its use as a diagnostic tool. In particular, the nova shells and massive star ejecta (MSE) plot on relatively tight loci illustrating their evolutionary sequences. For the MSE, there is potential to develop a distance indicator for these objects, based on their trend in $S-r$ space. As high-resolution, narrowband surveys of the nearest galaxies become more commonplace, the $S-r$ plane is a potentially useful diagnostic tool to help identify the various ionized nebulae in these systems.

  15. Large-scale solar magnetic fields and H-alpha patterns

    Mcintosh, P. S.

    1972-01-01

    Coronal and interplanetary magnetic fields computed from measurements of large-scale photospheric magnetic fields suffer from interruptions in day-to-day observations and the limitation of using only measurements made near the solar central meridian. Procedures were devised for inferring the lines of polarity reversal from H-alpha solar patrol photographs that map the same large-scale features found on Mt. Wilson magnetograms. These features may be monitored without interruption by combining observations from the global network of observatories associated with NOAA's Space Environment Services Center. The patterns of inferred magnetic fields may be followed accurately as far as 60 deg from central meridian. Such patterns will be used to improve predictions of coronal features during the next solar eclipse.

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

    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.

  17. H$_{\\alpha}$ line as an indicator of envelope presence around the Cepheid Polaris Aa ($\\alpha~ UMi$)

    Usenko, I A; Klochkova, V G; Tavolzhanskaya, N S

    2015-01-01

    We present the results of the radial velocity ($RV$) measurements of metallic lines as well as H$_{\\alpha}$ (H$_{\\beta}$) obtained in 55 high-resolution spectra of the Cepheid $\\alpha$ UMi (Polaris Aa) in 1994-2010. While the $RV$ amplitudes of these lines are roughly equal, their mean $RV$ begin to differ essentially with growth of the Polaris Aa pulsational activity. This difference is accompanied by the H$_{\\alpha}$ line core asymmetries on the red side mainly (so-called knife-like profiles) and reaches 8-12 km/s in 2003 with a subsequent decrease to 1.5-2 km/s. We interpret a so unusual behaviour of the H$_{\\alpha}$ line core as dynamical changes in the envelope around Polaris Aa.

  18. The critical velocity effect as a cause for the H\\alpha emission from the Magellanic stream

    Konz, C.; Lesch, H.; Birk, G. T.; Wiechen, H.

    2000-01-01

    Observations show significant H\\alpha-emissions in the Galactic halo near the edges of cold gas clouds of the Magellanic Stream. The source for the ionization of the cold gas is still a widely open question. In our paper we discuss the critical velocity effect as a possible explanation for the observed H\\alpha-emission. The critical velocity effect can yield a fast ionization of cold gas if this neutral gas passes through a magnetized plasma under suitable conditions. We show that for paramet...

  19. The critical velocity effect as a cause for the H\\alpha emission from the Magellanic stream

    Konz, C; Birk, G T; Wiechen, H

    2001-01-01

    Observations show significant H\\alpha-emissions in the Galactic halo near the edges of cold gas clouds of the Magellanic Stream. The source for the ionization of the cold gas is still a widely open question. In our paper we discuss the critical velocity effect as a possible explanation for the observed H\\alpha-emission. The critical velocity effect can yield a fast ionization of cold gas if this neutral gas passes through a magnetized plasma under suitable conditions. We show that for parameters that are typical for the Magellanic Stream the critical velocity effect has to be considered as a possible ionization source of high relevance.

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

    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...

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

    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...

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

    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...

  3. Evidence of Planetesimal infall on to the very young Herbig Be star LkH$_\\alpha$234

    Chakraborty, A; Mahadevan, S

    2004-01-01

    We report here the first evidence for planetesimal infall onto the very young Herbig Be star LkH$_\\alpha$234. These results are based on observations acquired over 31 days using spectroscopy of the sodium D lines, the He I 5876\\AA, and hydrogen H$_\\alpha$ lines. We find Redshifted Absorption Components (RAC) with velocities up to 200 km/s and very mild Blueshifted Absorption Components (BEC) up to 100 km/s in the Na I lines. No correlation is observed between the appearance of the Na I RAC & BEC and the H$_\\alpha$ and He I line variability, which suggests that these (Na I RAC & BEC) are formed in a process unrelated to the circumstellar gas accretion. We interpret the Na I RAC as evidence for an infalling evaporating body, greater than 100 km in diameter, which is able to survive at distances between 2.0 to 0.1 AU from the star. The dramatic appearance of the sodium RAC and mild BEC is readily explained by the dynamics of this infalling body making LkH$_\\alpha$234 the youngest (age $\\sim$ 0.1 Myr) sys...

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

    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...

  5. The KPNO International Spectroscopic Survey. V. H-alpha-selected Survey List 3

    Jangren, A; Sarajedini, V L; Gronwall, C; Werk, J K; Chomiuk, L; Moody, J W; Boroson, T A; Jangren, Anna; Salzer, John J.; Sarajedini, Vicki L.; Gronwall, Caryl; Werk, Jessica K.; Chomiuk, Laura; Boroson, Todd A.

    2005-01-01

    The KPNO International Spectroscopic Survey (KISS) is an objective-prism survey designed to detect extragalactic emission-line objects. It combines many of the features of previous slitless spectroscopic surveys with the advantages of modern CCD detectors, and is the first purely digital objective-prism survey for emission-line galaxies (ELGs). Here we present the third list of ELG candidates selected from our red spectral data, which cover the wavelength range 6400 to 7200 A. In most cases, the detected emission line is H-alpha. The current survey list covers the region of the NOAO Deep Wide-Field Survey (NDWFS). This survey covers two fields; the first is 3 x 3 degrees square and located at RA = 14h 30m, DEC = 34.5 deg (B1950), the second is 2.3 x 4.0 degrees and centered at RA = 2h 7.5m, DEC = -4.75 deg. A total area of 19.65 deg^2 is covered by the KISS data. A total of 261 candidate emission-line objects have been selected for inclusion in the survey list (13.3 per deg^2). We tabulate accurate coordinate...

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

    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...

  7. Star formation properties in the Local Volume galaxies via $H\\alpha$ and FUV fluxes

    Karachentsev, Igor D

    2013-01-01

    A distance-limited sample of 869 objects from the Updated Nearby Galaxy Catalog is used to characterize the star formation status of the Local Volume population. We present a compiled list of 1217 star formation rate (SFR) estimates for 802 galaxies within 11 Mpc from us, derived from the H-alpha imaging surveys and GALEX far-ultraviolet survey. We briefly discuss some basic scaling relations between SFR and luminosity, morphology, HI-mass, surface brightness, as well as environment of the galaxies. About 3/4 of our sample consist of dwarf galaxies, for which we offer a more refined classification. We note that the specific star formation rate of nearly all luminous and dwarf galaxies does not exceed the maximum value: $\\log(SFR/L_K) = -9.4$ [yr$^{-1}$]. The bulk of spiral and blue dwarf galaxies have enough time to generate their stellar mass during the cosmological time, $T_0$, with the observed SFRs. They dispose of a sufficient amount of gas to support their present SFRs over the next $T_0$ term. We note ...

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

    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 X² . 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.

  9. Graphs of Small Rank-width are Pivot-minors of Graphs of Small Tree-width

    Kwon, O-joung

    2012-01-01

    We prove that every graph of rank-width $k$ is a pivot-minor of a graph of tree-width at most $2k$. We also prove that graphs of rank-width at most 1, equivalently distance-hereditary graphs, are exactly vertex-minors of trees, and graphs of linear rank-width at most 1 are precisely vertex-minors of paths. In addition, we show that bipartite graphs of rank-width at most 1 are exactly pivot-minors of trees and bipartite graphs of linear rank-width at most 1 are precisely pivot-minors of paths.

  10. The most luminous H$\\alpha$ emitters at z~0.8-2.23 from HiZELS: evolution of AGN and star-forming galaxies

    Sobral, David; Best, Philip N; Smail, Ian; Harrison, Chris M; Stott, John; Calhau, João; Matthee, Jorryt

    2016-01-01

    We use new near-infrared spectroscopic observations to investigate the nature and evolution of the most luminous H\\alpha (Ha) emitters at z~0.8-2.23, which evolve strongly in number density over this period, and compare them to more typical Ha emitters. We study 59 luminous Ha emitters with $L_{H\\alpha}>L_{H\\alpha}^*$, roughly equally split per redshift slice at z~0.8, 1.47 and 2.23 from the HiZELS and CF-HiZELS surveys. We find that, overall, 30$\\pm$8% are AGN (80$\\pm$30% of these AGN are broad-line AGN, BL-AGN), and we find little to no evolution in the AGN fraction with redshift, within the errors. However, the AGN fraction increases strongly with Ha luminosity and correlates best with $L_{H\\alpha}/L_{H\\alpha}^*(z)$. While $L_{H\\alpha}80%), the most luminous Ha emitters ($L_{H\\alpha}>10L_{H\\alpha}^*(z)$) at any cosmic time are essentially all BL-AGN. Using our AGN-decontaminated sample of luminous star-forming galaxies, and integrating down to a fixed Ha luminosity, we find a factor of ~1300x evolution in ...

  11. Estimation of {sup 3}J{sub HN-H{alpha}} and {sup 3}J{sub H}{alpha}{sub -H{beta}} coupling constants from heteronuclear TOCSY spectra

    Pagano, Katiuscia; Fogolari, Federico, E-mail: ffogolari@mail.dstb.uniud.it; Corazza, Alessandra; Viglino, Paolo; Esposito, Gennaro [Universita di Udine, Dipartimento di Scienze e Tecnologie Biomediche (Italy)

    2007-11-15

    {sup 3}J proton-proton coupling constants bear information on the intervening dihedral angles. Methods have been developed to derive this information from NMR spectra of proteins. Using series expansion of the time dependent density matrix, and exploiting the simple topology of amino acid spin-systems, formulae for estimation of {sup 3}J{sub HN-H{alpha}} and {sup 3}J{sub H}{alpha}{sub -H{beta}} from HSQC-TOCSY spectra are derived. The results obtained on a protein entailing both {alpha}-helix and {beta}-sheet secondary structure elements agree very well with J-coupling constants computed from the X-ray structure. The method compares well with existing methods and requires only 2D spectra which would be typically otherwise recorded for structural studies.

  12. 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

    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.

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

    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...

  14. Cosmic Star Formation Activity at z=2.2 Probed by H-alpha Emission Line Galaxies

    Tadaki, Ken-ichi; Koyama, Yusei; Hayashi, Masao; Tanaka, Ichi; Tokoku, Chihiro

    2010-01-01

    We present a pilot narrow-band survey of H-alpha emitters at z=2.2 in the Great Observatories Origins Deep Survey North (GOODS-N) field with MOIRCS instrument on the Subaru telescope. The survey reached a 3 sigma limiting magnitude of 23.6 (NB209) which corresponds to a 3 sigma limiting line flux of 2.5 x 10^-17 erg s^-1 cm^-2 over a 56 arcmnin^2 contiguous area (excluding a shallower area). From this survey, we have identified 11 H-alpha emitters and one AGN at z=2.2 on the basis of narrow-band excesses and photometric redshifts. We obtained spectra for seven new objects among them, including one AGN, and an emission line above 3 sigma is detected from all of them. We have estimated star formation rates (SFR) and stellar masses (M_star) for individual galaxies. The average SFR and M_star is 27.8M_solar yr^-1 and 4.0 x 10^10M_solar, respectivly. Their specific star formation rates are inversely correlated with their stellar masses. Fitting to a Schechter function yields the H-alpha luminosity function with lo...

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

    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...

  16. A catalogue of early-type emission-line stars and H{\\alpha} line profiles from LAMOST DR2

    Hou, Wen; Hu, Jingyao; Yang, Haifeng; Du, Changde; Liu, Chao; Lee, Chien-De; Lin, Chien-Cheng; Wang, Yuefei; Zhang, Yong; Cao, Zihuang; Hou, Yonghui

    2016-01-01

    We present a catalogue including 11,204 spectra for 10,436 early-type emission-line stars from LAMOST DR2, among which 9,752 early-type emission-line spectra are newly discovered. For these early-type emission-line stars, we discuss the morphological and physical properties from their low-resolution spectra. In this spectral sample, the H$\\alpha$ emission profiles display a wide variety of shapes. Based on the H$\\alpha$ line profiles, these spectra are categorized into five distinct classes: single-peak emission, single-peak emission in absorption, double-peak emission, double-peak emission in absorption, and P-Cygni profiles. To better understand what causes the H$\\alpha$ line profiles, we divide these objects into four types from the view of physical classification, which include classical Be stars, Herbig Ae/Be stars, close binaries and spectra contaminated by HII regions. The majority of Herbig Ae/Be stars and classical Be stars are identified and separated using the (H-K, K-W1) color-color diagram. We al...

  17. Nature of H-alpha selected galaxies at z>2. II. Clumpy galaxies and compact star-forming galaxies

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

    2013-01-01

    We present the morphological properties of 109 H\\alpha-selected galaxies at z>2 in SXDF-UDS-CANDELS field. With high-resolution optical/near-infrared images obtained by Hubble Space Telescope, we identify giant clumps within the H\\alpha emitters (HAEs). We find that at least 41% of our sample show clumpy structures in the underlying disks. The color gradient of clumps is commonly seen in the sense that the clumps near the galactic center tend to be redder than those in the outer regions. The mid-infrared detection in galaxies with red clumps and the spatial distribution of H\\alpha emission suggest that dusty star-formation activity is probably occurring in the nuclear red clumps. A gas supply to a bulge component through the clump migration is one of the most potent physical processes to produce such dusty star-forming clumps and form massive bulges in local early-type galaxies. They would become large quiescent galaxies at later times just by consumption or blowout of remaining gas. Also, while most of the H...

  18. HIGH RESOLUTION H{alpha} IMAGES OF THE BINARY LOW-MASS PROPLYD LV 1 WITH THE MAGELLAN AO SYSTEM

    Wu, Y.-L.; Close, L. M.; Males, J. R.; Follette, K.; Morzinski, K.; Kopon, D.; Rodigas, T. J.; Hinz, P. [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Puglisi, A.; Esposito, S.; Pinna, E.; Riccardi, A.; Xompero, M.; Briguglio, R., E-mail: yalinwu@email.arizona.edu [INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Firenze (Italy)

    2013-09-01

    We utilize the new Magellan adaptive optics system (MagAO) to image the binary proplyd LV 1 in the Orion Trapezium at H{alpha}. This is among the first AO results in visible wavelengths. The H{alpha} image clearly shows the ionization fronts, the interproplyd shell, and the cometary tails. Our astrometric measurements find no significant relative motion between components over {approx}18 yr, implying that LV 1 is a low-mass system. We also analyze Large Binocular Telescope AO observations, and find a point source which may be the embedded protostar's photosphere in the continuum. Converting the H magnitudes to mass, we show that the LV 1 binary may consist of one very-low-mass star with a likely brown dwarf secondary, or even plausibly a double brown dwarf. Finally, the magnetopause of the minor proplyd is estimated to have a radius of 110 AU, consistent with the location of the bow shock seen in H{alpha}.

  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

    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. Equivalent Equilibria.

    Kandori, Michihiro

    1988-01-01

    This paper provides a way to formulate a general equilibrium model with both infinite time horizon and continuous uncertainty by 2.space, and provides a si mple proof of the equiva-lence of equilibria in complete markets, inc omplete markets with sequential trading, and incomplete markets with one-shot trades in single consumer economies. The proof is general in the sense that it does not assume time-homogeneous structure nor smo othness of preferences. The result guarantees that one can avoi...

  1. Resonances and resonance widths

    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

  2. Narrow Width Pentaquarks

    Buccella, F.; Sorba, P.

    A general study of pentaquarks built with four quarks in a L=1 state and an antiquark in S-wave shows that several of such states are forbidden by a selection rule, which holds in the limit of flavor symmetry, to decay into a baryon and a meson final state. We identify the most promising /line{10} multiplet for the classification of the Θ+ and Ξ-- particles recently discovered with the prediction of a narrow width for both of them.

  3. Narrow width pentaquarks

    Buccella, F

    2004-01-01

    A general study of pentaquarks built with four quarks in a L=1 state and an antiquark in S-wave shows that several of such states are forbidden by a selection rule, which holds in the limit of flavour symmetry, to decay into a baryon and a meson final state. We identify the most promising \\bar{10} multiplet for the classification of the Theta^+ and Xi^{--} particles recently discovered with the prediction of a narrow width for both of them.

  4. Laser-induced breakdown spectroscopy for in-cylinder equivalence ratio measurements in laser-ignited natural gas engines.

    Joshi, Sachin; Olsen, Daniel B; Dumitrescu, Cosmin; Puzinauskas, Paulius V; Yalin, Azer P

    2009-05-01

    In this contribution we present the first demonstration of simultaneous use of laser sparks for engine ignition and laser-induced breakdown spectroscopy (LIBS) measurements of in-cylinder equivalence ratios. A 1064 nm neodynium yttrium aluminum garnet (Nd:YAG) laser beam is used with an optical spark plug to ignite a single cylinder natural gas engine. The optical emission from the combustion initiating laser spark is collected through the optical spark plug and cycle-by-cycle spectra are analyzed for H(alpha)(656 nm), O(777 nm), and N(742 nm, 744 nm, and 746 nm) neutral atomic lines. The line area ratios of H(alpha)/O(777), H(alpha)/N(746), and H(alpha)/N(tot) (where N(tot) is the sum of areas of the aforementioned N lines) are correlated with equivalence ratios measured by a wide band universal exhaust gas oxygen (UEGO) sensor. Experiments are performed for input laser energy levels of 21 mJ and 26 mJ, compression ratios of 9 and 11, and equivalence ratios between 0.6 and 0.95. The results show a linear correlation (R(2) > 0.99) of line intensity ratio with equivalence ratio, thereby suggesting an engine diagnostic method for cylinder resolved equivalence ratio measurements. PMID:19470212

  5. Multiwavelength Signatures of Magnetic Activity from Young Stellar Objects in the LkH\\alpha101 Cluster

    Osten, R. A.; Wolk, S. J.

    2008-01-01

    [abridged] We describe the results of our multi-wavelength observing campaign on the young stellar objects in the LkH$\\alpha$101 cluster. Our simultaneous X-ray and multi-frequency radio observations are unique in providing simultaneous constraints on short-timescale variability at both wavelengths as well as constraints on the thermal or nonthermal nature of radio emission from young stars. Focussing in on radio-emitting objects and the multi-wavelength data obtained for them, we find that m...

  6. WHAM Observations of $H-\\alpha$, [S II], and [N II] toward the Orion and Perseus Arms Probing the Physical Conditions of the Warm Ionized Medium

    Haffner, L M; Tufte, S L

    1999-01-01

    A large portion of the Galaxy (l = 123 deg to 164 deg, b = -6 deg to -35 deg), which samples regions of the Local (Orion) spiral arm and the more distant Perseus arm, has been mapped with the Wisconsin H-Alpha Mapper (WHAM) in the H-Alpha, [S II] 6716, and [N II] 6583 lines. Several trends noticed in emission-line investigations of diffuse gas in other galaxies are confirmed in the Milky Way and extended to much fainter emission. We find that the [S II]/H-Alpha and [N II]/H-Alpha ratios increase as absolute H-Alpha intensities decrease. For the more distant Perseus arm emission, the increase in these ratios is a strong function of Galactic latitude and thus, of height above the Galactic plane. The [S II]/[N II] ratio is relatively independent of H-Alpha intensity. Scatter in this ratio appears to be physically significant, and maps of it suggest regions with similar ratios are spatially correlated. The Perseus arm [S II]/[N II] ratio is systematically lower than Local emission by 10%--20%. With [S II]/[N II] ...

  7. Level Width Broaden Effect

    ZHANG Jing-Shang

    2004-01-01

    In fitting the double-differential measurements thelevelwidth broadening effect should be taken into account properly due to Heisenberg uncertainty.Besides level width broadening effect the energy resolution in the measurements is also needed in this procedure.In general,the traditional normal Gaussian expansion is employed.However,the research indicates that to do so in this way the energy balance could not hold.For this reason,the deformed Gaussian expansion functions with exponential form for both the single energy point and continuous spectrum are introduced,with which the normalization and energy balance conditions could hold exactly in the analytical form.

  8. Multi-epoch Spectroscopy of Dwarf Galaxies with AGN Signatures: Identifying Sources with Persistent Broad H-alpha Emission

    Baldassare, Vivienne F; Gallo, Elena; Greene, Jenny E; Graur, Or; Geha, Marla; Hainline, Kevin; Carroll, Christopher M; Hickox, Ryan C

    2016-01-01

    We use time-domain optical spectroscopy to distinguish between broad emission lines powered by accreting black holes (BHs) or stellar processes (i.e., supernovae) for 16 galaxies identified as AGN candidates by Reines et al. (2013). 14 of these have star-formation--dominated narrow-line emission ratios, one is a narrow-line AGN, and the last is a star-forming--AGN composite. We find that broad H$\\alpha$ emission has faded for 11/16 targets, based on spectra taken with the Magellan Echellette Spectrograph (MagE), the Dual Imaging Spectrograph, and the Ohio State Multi-Object Spectrograph with baselines ranging from 5 to 14 years. The 11 faded systems all have narrow-line ratios consistent with recent star formation, suggesting the broad emission for those targets was produced by a transient stellar process. The two objects with narrow-line AGN signatures (RGG 9 and RGG 119) have persistent broad H$\\alpha$ emission consistent with previous SDSS observations. The final three star-forming objects are classified a...

  9. Full-disk Synoptic Observations of the Chromosphere Using H$_{\\alpha}$ Telescope at the Kodaikanal Observatory

    Ravindra, B; Rangarajan, K E; Bagare, S P; Jagdev, Singh; Kemkar, P M M; Lancelot, J P; Thulasidharen, K C; Gabriel, F; Selvendran, R

    2016-01-01

    This paper reports on the installation and observations of a new solar telescope installed on 7th October, 2014 at the Kodaikanal Observatory. The telescope is a refractive type equipped with a tunable Lyot H$_{\\alpha}$ filter. A CCD camera of 2k$\\times$2k size makes the image of the Sun with a pixel size of 1.21$^{\\prime\\prime}$ pixel$^{-1}$ with a full field-of-view of 41$^{\\prime}$. The telescope is equipped with a guiding system which keeps the image of the Sun within a few pixels throughout the observations. The FWHM of the Lyot filter is 0.4\\AA~and the filter is motorized, capable of scanning the H$_{\\alpha}$ line profile at a smaller step size of 0.01\\AA. Partial-disk imaging covering about 10$^{\\prime}$, is also possible with the help of a relay lens kept in front of the CCD camera. In this paper, we report the detailed specifications of the telescope, filter unit, its installation, observations and the procedures we have followed to calibrate and align the data. We also present preliminary results wi...

  10. Artificial neural network based calibrations for the prediction of galactic [NII] $\\lambda$ 6584 and H$\\alpha$ line luminosities

    Teimoorinia, Hossein

    2014-01-01

    The artificial neural network (ANN) is a well-established mathematical technique for data prediction, based on the identification of correlations and pattern recognition in input training sets. We present the application of ANNs to predict the emission line luminosities of H$\\alpha$ and [NII] $\\lambda$6584 in galaxies. These important spectral diagnostics are used for metallicities, active galactic nuclei (AGN) classification and star formation rates, yet are shifted into the infra-red for galaxies above $z \\sim 0.5$, or may not be covered in spectra with limited wavelength coverage. The ANN is trained with a large sample of emission line galaxies selected from the Sloan Digital Sky Survey using various combinations of emission lines and stellar mass. The ANN is tested for galaxies dominated by both star formation and AGN; in both cases the H$\\alpha$ and [NII] $\\lambda$6584 line luminosities can be predicted with a scatter $\\sigma <$ 0.1 dex. We also show that the performance of the ANN does not depend sig...

  11. Heavily Reddened z~2 Type 1 Quasars II: H-alpha Star Formation Constraints from SINFONI IFU Observations

    Alaghband-Zadeh, Susannah; Hewett, Paul C; McMahon, Richard G

    2016-01-01

    We use near infrared integral field unit (IFU) spectroscopy to search for H$\\alpha$ emission associated with star formation in a sample of 28 heavily reddened ($E(B-V)\\simeq$0.5-1.9), hyperluminous ($log(L_{bol}/ergs^{-1})\\simeq$47-48) broad-line quasars at $z\\simeq$1.4-2.7. Sixteen of the 28 quasars show evidence for star formation with an average extinction-corrected star formation rate (SFR) of 320$\\pm$70M$_\\odot$yr$^{-1}$. A stacked spectrum of the detections shows weak [NII], consistent with star formation as the origin of the narrow H$\\alpha$ emission. The star-forming regions are spatially unresolved in 11 of the 16 detections and constrained to lie within $\\sim$6kpc of the quasar emission. In the five resolved detections we find the star-forming regions are extended on scales of $\\sim$8kpc around the quasar emission. The prevalence of high SFRs is consistent with the identification of the heavily reddened quasar population as representing a transitional phase from apparent `starburst galaxies' to opti...

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

    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...

  13. COMPARING H{alpha} AND H I SURVEYS AS MEANS TO A COMPLETE LOCAL GALAXY CATALOG IN THE ADVANCED LIGO/VIRGO ERA

    Metzger, Brian D. [Department of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08542 (United States); Kaplan, David L. [Physics Department, University of Wisconsin-Milwaukee, Milwaukee, WI 53211 (United States); Berger, Edo, E-mail: bmetzger@astro.princeton.edu, E-mail: kaplan@uwm.edu, E-mail: eberger@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2013-02-20

    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 {approx}10-100 deg{sup 2} 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 {approx}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 narrowband H{alpha} imaging survey and (2) an H I emission line radio survey. Using H{alpha} fluxes, stellar masses (M {sub *}), and star formation rates (SFRs) from galaxies in the Sloan Digital Sky Survey (SDSS), combined with H I data from the GALEX Arecibo SDSS Survey and the Herschel Reference Survey, we estimate that an H{alpha} survey with a luminosity sensitivity of L {sub H{alpha}} = 10{sup 40} erg s{sup -1} at 200 Mpc could achieve a completeness of f {sup H{alpha}} {sub SFR} Almost-Equal-To 75% with respect to total SFR, but only f{sub M* Star-Operator }{sup H{alpha}} approx. 33% with respect to M {sub *} (due to lack of sensitivity to early-type galaxies). These numbers are significantly lower than those achieved by an idealized spectroscopic survey due to the loss of H{alpha} flux resulting from resolving out nearby galaxies and the inability to correct for the underlying stellar continuum. An H I survey with sensitivity similar to the proposed WALLABY survey on ASKAP could achieve f{sub SFR}{sup H{sub I}} Almost-Equal-To 80% and f{sub M Star-Operator }{sup H{sub I}} Almost-Equal-To 50%, somewhat higher than that of the H{alpha} survey. Finally, both H{alpha} and H I surveys should achieve {approx}> 50% completeness with respect to the host galaxies of

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

    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$^{-1}$.

  15. SDSS J083253.18+064316.7: one strange object with double-peaked narrow H\\alpha but single-peaked narrow H\\beta

    Zhang, XueGuang

    2015-01-01

    In this letter, we firstly report one unique object SDSS J0832+0643 with particular features of narrow balmer emission lines: double-peaked narrow H\\alpha but single-peaked narrow H\\beta. The particular features can not be expected by currently proposed kinematic models for double-peaked narrow emission lines, because the proposed kinematic models lead to similar line profiles of narrow balmer emission lines. However, due to radiative transfer effects, the non-kinematic model can be naturally applied to well explain the particular features of narrow balmer emission lines: larger optical depth in H\\alpha than 10 leads to observed double-peaked narrow H\\alpha, but smaller optical depth in H\\beta around 2 leads to observed single-peaked narrow H\\beta. Therefore, SDSS J0832+0643 can be used as strong evidence to support the non-kinematic model for double-peaked narrow emission lines.

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

    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...

  17. The MOSDEF Survey: Dissecting the star-formation rate vs. stellar mass relation using H$\\alpha$ and H$\\beta$ emission lines at z ~ 2

    Shivaei, Irene; Shapley, Alice E; Kriek, Mariska; Siana, Brian; Mobasher, Bahram; Coil, Alison L; Freeman, William R; Sanders, Ryan; Price, Sedona H; de Groot, Laura; Azadi, Mojegan

    2015-01-01

    We present results on the SFR-$M_*$ relation (i.e., the "main sequence") among star-forming galaxies at $1.37\\leq z \\leq2.61$ using the MOSFIRE Deep Evolution Field (MOSDEF) survey. Based on a sample of 261 star-forming galaxies with observations of H$\\alpha$ and H$\\beta$ emission lines, we have estimated robust dust-corrected instantaneous star-formation rates (SFRs) over a large dynamic range in stellar mass ($\\sim 10^{9.0}-10^{11.5}M_\\odot$). We find a tight correlation between SFR(H$\\alpha$) and $M_*$ with an intrinsic scatter of 0.36 dex, 0.05 dex larger than that of UV-based SFRs. This increased scatter is consistent with predictions from numerical simulations of 0.03 - 0.1 dex, and is attributed to H$\\alpha$ more accurately tracing SFR variations. The slope of the $\\log(\\text{SFR})-\\log(M_*)$ relation, using SFR(H$\\alpha$), at $1.4< z<2.6$ and over the stellar mass range of $10^{9.5}$ to $10^{11.5}M_\\odot$ is $0.65\\pm 0.09$. We find that different assumptions for the dust correction, such as usin...

  18. H$\\alpha$ Velocity Fields and Galaxy Interaction in the Quartet of Galaxies NGC 7769, 7770, 7771 and 7771A

    A. A. Yeghiazaryan; T. A. Nazaryan; A. A. Hakobyan

    2016-03-01

    The quartet of galaxies NGC 7769, 7770, 7771 and 7771A is a system of interacting galaxies. Close interaction between galaxies caused characteristic morphological features: tidal arms and bars, as well as an induced star formation. In this study, we performed the Fabry–Perot scanning interferometry of the system in H\\alpha line and studied the velocity fields of the galaxies. We found that the rotation curve of NGC 7769 is weakly distorted. The rotation curve of NGC 7771 is strongly distorted with the tidal arms caused by direct flyby of NGC 7769 and flyby of a smaller neighbor NGC 7770. The rotation curve of NGC 7770 is significantly skewed because of the interaction with the much massive NGC 7771. The rotation curves and morphological disturbances suggest that the NGC 7769 and NGC 7771 have passed the first pericenter stage, however, probably the second encounter has not happened yet. Profiles of surface brightness of NGC 7769 have a characteristic break, and profiles of color indices have a minimum at a radius of intensive star formation induced by the interaction with NGC 7771.

  19. SMA observations towards the compact, short-lived bipolar water maser outflow in the LkH{\\alpha} 234 region

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

    2016-01-01

    We present Submillimeter Array (SMA) 1.35 mm subarcsecond angular resolution observations toward the LkH{\\alpha} 234 intermediate-mass star-forming region. The dust emission arises from a filamentary structure of $\\sim$5 arcsec ($\\sim$4500 au) enclosing VLA 1-3 and MM 1, perpendicular to the different outflows detected in the region. The most evolved objects are located at the southeastern edge of the dust filamentary structure and the youngest ones at the northeastern edge. The circumstellar structures around VLA 1, VLA 3, and MM 1 have radii between $\\sim$200 and $\\sim$375 au and masses in the $\\sim$0.08-0.3 M$_{\\odot}$ range. The 1.35 mm emission of VLA 2 arises from an unresolved (r$< 135$ au) circumstellar disk with a mass of $\\sim$0.02 M$_{\\odot}$. This source is powering a compact ($\\sim$4000 au), low radial velocity ($\\sim$7 km s$^{-1}$) SiO bipolar outflow, close to the plane of the sky. We conclude that this outflow is the "large-scale" counterpart of the short-lived, episodic, bipolar outflow ob...

  20. Probabilistic Analysis of Crack Width

    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.

  1. A deterministic width function model

    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.

  2. THE PHOTOMETRIC AND KINEMATIC STRUCTURE OF FACE-ON DISK GALAXIES. III. KINEMATIC INCLINATIONS FROM H{alpha} VELOCITY FIELDS

    Andersen, David R. [NRC Herzberg Institute of Astrophysics, 5071 W Saanich Road, Victoria, BC V9E 2E7 (Canada); Bershady, Matthew A., E-mail: david.andersen@nrc-cnrc.gc.ca, E-mail: mab@astro.wisc.edu [Department of Astronomy, University of Wisconsin, 475 N Charter Street, Madison, WI 53706 (United States)

    2013-05-01

    Using the integral field unit DensePak on the WIYN 3.5 m telescope we have obtained H{alpha} velocity fields of 39 nearly face-on disks at echelle resolutions. High-quality, uniform kinematic data and a new modeling technique enabled us to derive accurate and precise kinematic inclinations with mean i{sub kin} = 23 Degree-Sign for 90% of these galaxies. Modeling the kinematic data as single, inclined disks in circular rotation improves upon the traditional tilted-ring method. We measure kinematic inclinations with a precision in sin i of 25% at 20 Degree-Sign and 6% at 30 Degree-Sign . Kinematic inclinations are consistent with photometric and inverse Tully-Fisher inclinations when the sample is culled of galaxies with kinematic asymmetries, for which we give two specific prescriptions. Kinematic inclinations can therefore be used in statistical ''face-on'' Tully-Fisher studies. A weighted combination of multiple, independent inclination measurements yield the most precise and accurate inclination. Combining inverse Tully-Fisher inclinations with kinematic inclinations yields joint probability inclinations with a precision in sin i of 10% at 15 Degree-Sign and 5% at 30 Degree-Sign . This level of precision makes accurate mass decompositions of galaxies possible even at low inclination. We find scaling relations between rotation speed and disk-scale length identical to results from more inclined samples. We also observe the trend of more steeply rising rotation curves with increased rotation speed and light concentration. This trend appears to be uncorrelated with disk surface brightness.

  3. H-alpha Variability in PTFO8-8695 and the Possible Direct Detection of Emission from a 2 Million Year Old Evaporating Hot Jupiter

    Johns-Krull, Christopher M; McLane, Jacob N; Ciardi, David R; van Eyken, Julian C; Chen, Wei; Stauffer, John R; Beichman, Charles A; Frazier, Sarah A; Boden, Andrew F; Morales-Calderon, Maria; Rebull, Luisa M

    2016-01-01

    We use high time cadence, high spectral resolution optical observations to detect excess H-alpha emission from the 2 - 3 Myr old weak lined T Tauri star PTFO8-8695. This excess emission appears to move in velocity as expected if it were produced by the suspected planetary companion to this young star. The excess emission is not always present, but when it is, the predicted velocity motion is often observed. We have considered the possibility that the observed excess emission is produced by stellar activity (flares), accretion from a disk, or a planetary companion; we find the planetary companion to be the most likely explanation. If this is the case, the strength of the H-alpha line indicates that the emission comes from an extended volume around the planet, likely fed by mass loss from the planet which is expected to be overflowing its Roche lobe.

  4. The RINGS Survey: High-Resolution H-alpha Velocity Fields of Nearby Spiral Galaxies with the SALT Fabry-Perot

    Mitchell, Carl J; Williams, T B; Spekkens, Kristine; Lee-Waddell, K; de Naray, Rachel Kuzio

    2015-01-01

    We have obtained high-spatial-resolution spectrophotometric data on several nearby spiral galaxies with the Southern African Large Telescope (SALT) Fabry-P\\'erot interferometer on the Robert Stobie Spectrograph (RSS) as a part of the RSS Imaging spectroscopy Nearby Galaxy Survey (RINGS). We have successfully reduced two tracks of Fabry-P\\'erot data for the galaxy NGC 2280 to produce a velocity field of the H-alpha line of excited hydrogen. We have modeled these data with the DiskFit modeling software and found these models to be in excellent agreement both with previous measurements in the literature and with our lower-resolution HI velocity field of the same galaxy. Despite this good agreement, small regions exist where the difference between the H-alpha and HI velocities is larger than would be expected from typical dispersions. We investigate these regions of high velocity difference and offer possible explanations for their existence.

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

    Hao, Qi; Fang, Cheng; 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, fila...

  6. Star formation, extinction and metallicity at 0.7H-alpha fluxes and sizes from a grism survey of GOODS-N

    Weiner, Benjamin

    2009-07-01

    The global star formation rate {SFR} is 10x higher at z=1 than today. This could be due to drastically elevated SFR in some fraction of galaxies, such as mergers with central bursts, or a higher SFR across the board. Either means that the conditions in z=1 star forming galaxies could be quite different from local objects. The next step beyond measuring the global SFR is to determine the dependence of SFR, obscuration, metallicity, and size of the star-forming region on galaxy mass and redshift. However, SFR indicators at z=1 typically apply local calibrations for UV, [O II] and far-IR, and do not agree with each other on a galaxy-by-galaxy basis. Extinction, metallicity, and dust properties cause uncontrolled offsets in SFR calibrations. The great missing link is Balmer H-alpha, the most sensitive probe of SFR. We propose a slitless WFC3/G141 IR grism survey of GOODS-N, at 2 orbits/pointing. It will detect Ha+[N II] emission from 0.7 600 galaxies, and a small number of higher-redshift emitters. This will produce: an emission-line redshift survey unbiased by magnitude and color selection; star formation rates as a function of galaxy properties, e.g. stellar mass and morphology/mergers measured by ACS; comparisons of SFRs from H-alpha to UV and far-IR indicators; calibrations of line ratios of H-alpha to important nebular lines such as [O II] and H-beta, measuring variations in metallicity and extinction and their effect on SFR estimates; and the first measurement of scale lengths of the H-alpha emitting, star-forming region in a large sample of z 1 sources.

  7. Politico-economic equivalence

    Gonzalez Eiras, Martin; Niepelt, Dirk

    2015-01-01

    Traditional "economic equivalence'' results, like the Ricardian equivalence proposition, define equivalence classes over exogenous policies. We derive "politico-economic equivalence" conditions that apply in environments where policy is endogenous and chosen sequentially. A policy regime and a...... state are equivalent to another such pair if both pairs give rise to the same allocation in politico-economic equilibrium. The equivalence conditions help to identify factors that render institutional change non-neutral and to construct politico-economic equilibria in new policy regimes. We exemplify...

  8. Biological width: No violation zone

    Ashu Sharma

    2012-01-01

    Full Text Available Maintenance of gingival health is one of the keys for the longevity of teeth, as well as for the longevity of restorations. The concept of Biologic width has been widely described by periodontists and restorative dentists. An adequate understanding of relationship between periodontal tissues and restorative dentistry is paramount to ensure adequate form, function and esthetics, and comfort of the dentition. While most clinicians are aware of this important relationship, uncertainty remains regarding specific concepts such as biologic width and indications and applications of surgical crown lengthening. These violations lead to complications like gingival inflammation, alveolar bone loss and improper fit of the restorative component. This review gives the wide aspect of the complex question of biologic width and represents an attempt to answer some of the demands in relation to it. The article also discusses the possible methods to assess biologic width, problems that occur after improper margin placement in the periodontium and the alternative procedures for prevention of biological width violation.

  9. On the properties of galaxies at the faint-end of the H$\\alpha$ luminosity function at $z\\sim0.62$

    Gómez-Guijarro, Carlos; Villar, Víctor; Rodríguez-Muñoz, Lucía; Clément, Benjamin; Cuby, Jean-Gabriel

    2016-01-01

    Studies measuring the star formation rate density, luminosity function and properties of star-forming galaxies are numerous. However, it exists a gap at $0.5H$\\alpha$-based studies. Our main goal is to study the properties of a sample of faint H$\\alpha$ emitters at $z\\sim0.62$. We focus on their contribution to the faint-end of the luminosity function and derived star formation rate density, characterising their morphologies and basic photometric and spectroscopic properties. We use a narrow-band technique in the near-infrared, with a filter centered at 1.06 $\\mu$m. The data come from ultra-deep VLT/HAWK-I observations in the GOODS-S field with a total of 31.9 h in the narrow-band filter. We perform a visual classification of the sample and study their morphologies from structural parameters available in CANDELS. Our 28 H$\\alpha$-selected sample of faint star-forming galaxies reveals a robust faint-end slope of the luminosity function $\\alpha=-1.46_{-0.08}^{+0.16}$. The derived star formation...

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

    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...

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

    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.

  12. Equivalence principles and electromagnetism

    Ni, W.-T.

    1977-01-01

    The implications of the weak equivalence principles are investigated in detail for electromagnetic systems in a general framework. In particular, it is shown that the universality of free-fall trajectories (Galileo weak equivalence principle) does not imply the validity of the Einstein equivalence principle. However, the Galileo principle plus the universality of free-fall rotation states does imply the Einstein principle.

  13. Equivalence in Translation

    李良杰

    2013-01-01

    There are many researches about translation theories and methods in western translation history. Equivalence in transla⁃tion has always been the central issue for discussion. This paper gives a general review and comment on equivalence in translation in terms of three representative translation theorists and their views about equivalence in translation.

  14. On the maximal diphoton width

    Salvio, Alberto; Staub, Florian; Strumia, Alessandro; Urbano, Alfredo

    2016-03-01

    Motivated by the 750 GeV diphoton excess found at LHC, we compute the maximal width into γγ that a neutral scalar can acquire through a loop of charged fermions or scalars as function of the maximal scale at which the theory holds, taking into account vacuum (meta)stability bounds. We show how an extra gauge symmetry can qualitatively weaken such bounds, and explore collider probes and connections with Dark Matter.

  15. On the maximal diphoton width

    Salvio, Alberto; Strumia, Alessandro; Urbano, Alfredo

    2016-01-01

    Motivated by the 750 GeV diphoton excess found at LHC, we compute the maximal width into $\\gamma\\gamma$ that a neutral scalar can acquire through a loop of charged fermions or scalars as function of the maximal scale at which the theory holds, taking into account vacuum (meta)stability bounds. We show how an extra gauge symmetry can qualitatively weaken such bounds, and explore collider probes and connections with Dark Matter.

  16. Characterization of revenue equivalence

    Heydenreich, Birgit; Müller, Rudolf; Uetz, Marc

    2007-01-01

    The property of an allocation rule to be implementable in dominant strategies by a unique payment scheme is called revenue equivalence. In this paper we give a characterization of revenue equivalence based on a graph theoretic interpretation of the incentive compatibility constraints. The characterization holds for any (possibly in¯nite) outcome space and many of the known results about revenue equivalence are immediate consequences.

  17. Characterization of Revenue Equivalence

    Heydenreich, B.; Müller, R.J.; Uetz, M.J.; R. Vohra

    2008-01-01

    The property of an allocation rule to be implementable in dominant strategies by a unique payment scheme is called \\emph{revenue equivalence}. In this paper we give a characterization of revenue equivalence based on a graph theoretic interpretation of the incentive compatibility constraints. The characterization holds for any (possibly infinite) outcome space and many of the known results are immediate consequences. Moreover, revenue equivalence can be identified in cases where existing theor...

  18. Measurement of effective sheath width around the cutoff probe based on electromagnetic simulation

    Kim, D. W.; You, S. J.; Kim, J. H.; Chang, H. Y.; Yoon, J.-S.; Oh, W. Y.

    2016-05-01

    We inferred the effective sheath width using the cutoff probe and incorporating a full-wave three-dimensional electromagnetic (EM) simulation. The EM simulation reproduced the experimentally obtained plasma-sheath resonance (PSR) on the microwave transmission (S21) spectrum well. The PSR frequency has a one-to-one correspondence with the width of the vacuum layer assumed to be the effective sheath in the EM simulation model. The sheath width was estimated by matching the S21 spectra of the experiment and the EM simulation for different widths of the sheath. We found that the inferred sheath widths quantitatively and qualitatively agree with the sheath width measured by incorporating an equivalent circuit model. These results demonstrate the excellent potential of the cutoff probe for inferring the effective sheath width from its experimental spectrum data.

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

    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 photometric data of CFHTLS-W...

  20. Inferred H{\\alpha} Flux as a Star-Formation Rate Indicator at z ~ 4-5: Implications for Dust Properties, Burstiness, and the z = 4-8 Star-Formation-Rate Functions

    Smit, Renske; Labbé, Ivo; Franx, Marijn; Wilkins, Stephen M; Oesch, Pascal A

    2015-01-01

    We derive H{\\alpha} fluxes for a large spectroscopic and photometric-redshift-selected sample of sources over GOODS-North and South in the redshift range z = 3.8-5.0 with deep HST, Spitzer/IRAC, and ground-based observations. The H{\\alpha} flux is inferred based on the offset between the IRAC 3.6 {\\mu}m flux and that predicted from the best-fit SED. We demonstrate that the H{\\alpha} flux correlates well with dust- corrected UV star-formation rate (SFR) and therefore can serve as an independent SFR indicator. However, we also find a systematic offset in the SFR_H{\\alpha}/SFR_UV ratios for z ~ 4-5 galaxies relative to local relations (assuming the same dust corrections for nebular regions and stellar light). We show that we can resolve the modest tension in the inferred SFRs by assuming bluer intrinsic UV slopes (increasing the dust correction), a rising star-formation history or assuming a low metallicity stellar population with a hard ionizing spectrum (increasing the L_H{\\alpha}/SFR ratio). Using H{\\alpha} a...

  1. Characterization of revenue equivalence

    Heydenreich, B.; Müller, R.; Uetz, M.J.; Vohra, R.

    2009-01-01

    The property of an allocation rule to be implementable in dominant strategies by a unique payment scheme is called revenue equivalence. We give a characterization of revenue equivalence based on a graph theoretic interpretation of the incentive compatibility constraints. The characterization holds f

  2. Characterization of revenue equivalence

    Heydenreich, Birgit; Müller, Rudolf; Uetz, Marc; Vohra, Rakesh

    2008-01-01

    The property of an allocation rule to be implementable in dominant strategies by a unique payment scheme is called \\emph{revenue equivalence}. In this paper we give a characterization of revenue equivalence based on a graph theoretic interpretation of the incentive compatibility constraints. The cha

  3. Constraining the Age and Distance of the Galactic Supernova Remnant G156.2+5.7 by H-alpha Expansion Measurements

    Katsuda, Satoru; Morokuma, Tomoki; Fesen, Robert; Milisavljevic, Dan

    2016-01-01

    We present deep H-alpha images of portions of the X-ray bright but optically faint Galactic supernova remnant G156.2+5.7, revealing numerous and delicately thin nonradiative filaments which mark the location of the remnant's forward shock. These new images show that these filaments have a complex structure not visible on previous lower resolution optical images. By comparing H-alpha images taken in 2004 at the McDonald Observatory and in 2015-2016 at the Kiso Observatory, we set a stringent 1-sigma upper limit of expansion to be 0.06 arcsec/yr. This proper motion, combined with a shock speed of 500 km/s inferred from X-ray spectral analyses, gives a distance of > 1.7 kpc. In addition, a simple comparison of expansion indices of several SNRs allows us to infer the age of the remnant to be a few 10,000 yr old. These estimates are more straightforward and reliable than any other previous studies, and clearly rule out a possibility that G156.2+5.7 is physically associated with part of the Taurus-Auriga cloud and ...

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

    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...

  5. The H$\\alpha$ line forming region of AB Aur spatially resolved at sub-AU with the VEGA/CHARA spectro-interferometer

    Perraut, K; Mourard, D; Rajabi, S; Bacciotti, F; Bério, Ph; Bonneau, D; Chesneau, O; Clausse, J M; Delaa, O; Marcotto, A; Roussel, A; Spang, A; Stee, Ph; Tallon-Bosc, I; McAlister, H; Brummelaar, T ten; Sturmann, J; Sturmann, L; Turner, N; Farrington, C; Goldfinger, P J

    2010-01-01

    A crucial issue in star formation is to understand the physical mechanism by which mass is accreted onto and ejected by a young star. The visible spectrometer VEGA on the CHARA array can be an efficient means of probing the structure and the kinematics of the hot circumstellar gas at sub-AU. For the first time, we observed the Herbig Ae star AB Aur in the H$\\alpha$ emission line, using the VEGA low spectral resolution on two baselines of the array. We computed and calibrated the spectral visibilities between 610 nm and 700 nm. To simultaneously reproduce the line profile and the visibility, we used a 1-D radiative transfer code that calculates level populations for hydrogen atoms in a spherical geometry and synthetic spectro-interferometric observables. We clearly resolved AB Aur in the H$\\alpha$ line and in a part of the continuum, even at the smallest baseline of 34 m. The small P-Cygni absorption feature is indicative of an outflow but could not be explained by a spherical stellar wind model. Instead, it f...

  6. GHASP: an H$\\alpha$ kinematic survey of spiral galaxies - X. Surface photometry, decompositions and the Tully-Fisher relation in the Rc-band

    Barbosa, C E; Amram, P; Ferrari, F; Russeil, D; Epinat, B; Perret, V; Adami, C; Marcelin, M

    2015-01-01

    We present Rc-band surface photometry for 170 of the 203 galaxies in GHASP, Gassendi H-Alpha survey of SPirals, a sample of late-type galaxies for which high-resolution Fabry-Perot H{\\alpha} maps have previously been obtained. Our data set is constructed by new Rc-band observations taken at the Observatoire de Haute-Provence (OHP), supplemented with Sloan Digital Sky Survey (SDSS) archival data, obtained with the purpose of deriving homogeneous photometric profiles and parameters. Our results include Rc-band surface brightness profiles for 170 galaxies and $ugriz$ profiles for 108 of these objects. We catalogue several parameters of general interest for further reference, such as total magnitude, effective radius and isophotal parameters -- magnitude, position angle, ellipticity and inclination. We also perform a structural decomposition of the surface brightness profiles using a multi-component method in order to separate disks from bulges and bars, and to observe the main scaling relations involving luminos...

  7. H-alpha Activity of Old M Dwarfs: Stellar Cycles and Mean Activity Levels For 93 Low-Mass Stars in the Solar Neighborhood

    Robertson, Paul; Cochran, William D; Dodson-Robinson, Sarah E

    2012-01-01

    Through the McDonald Observatory M Dwarf Planet Search, we have acquired nearly 3,000 high-resolution spectra of 93 late-type (K5-M5) stars over more than a decade using HET/HRS. 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 6 stars, with periods ranging from days to more than 10 years, and find long-term trends for 7 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...

  8. The MOSDEF Survey: The strong agreement between H-alpha and UV-to-FIR star formation rates for z~2 star-forming galaxies

    Shivaei, Irene; Reddy, Naveen A; Shapley, Alice E; Barro, Guillermo; Conroy, Charlie; Coil, Alison L; Freeman, William R; Mobasher, Bahram; Siana, Brian; Sanders, Ryan; Price, Sedona H; Azadi, Mojegan; Pasha, Imad; Inami, Hanae

    2016-01-01

    We present the first direct comparison between Balmer line and panchromatic SED-based SFRs for z~2 galaxies. For this comparison we used 17 star-forming galaxies selected from the MOSFIRE Deep Evolution Field (MOSDEF) survey, with $3\\sigma$ detections for H$\\alpha$ and at least two IR bands (Spitzer/MIPS 24$\\mu$m and Herschel/PACS 100 and 160$\\mu$m, and in some cases Herschel/SPIRE 250, 350, and 500$\\mu$m). The galaxies have total IR (8-1000$\\mu$m) luminosities of $\\sim10^{11.4}-10^{12.4}\\,\\textrm{L}_\\odot$ and star-formation rates (SFRs) of $\\sim30-250\\,\\textrm{M}_\\odot\\,\\mathrm{yr^{-1}}$. We fit the UV-to-far-IR SEDs with flexible stellar population synthesis (FSPS) models - which include both stellar and dust emission - and compare the inferred SFRs with the SFR(H$\\alpha$,H$\\beta$) values corrected for dust attenuation using Balmer decrements. The two SFRs agree with a scatter of 0.17 dex. Our results imply that the Balmer decrement accurately predicts the obscuration of the nebular lines and can be used t...

  9. Narrow-width approximation accuracy

    A study of general properties of the narrow-width approximation (NWA) with polarization/spin decorrelation is presented. We prove for sufficiently inclusive differential rates of arbitrary resonant decay or scattering processes with an on-shell intermediate state decaying via a cubic or quartic vertex that decorrelation effects vanish and the NWA is of order Γ. Its accuracy is then determined numerically for all resonant 3-body decays involving scalars, spin-1/2 fermions or vector bosons. We specialize the general results to MSSM benchmark scenarios. Significant off-shell corrections can occur - similar in size to QCD corrections. We qualify the configurations in which a combined consideration is advisable. For this purpose, we also investigate process-independent methods to improve the NWA

  10. On U-equivalence spaces

    Omidi Farshad; Molaei MohammadReza

    2015-01-01

    In this paper induced U-equivalence spaces are introduced and discussed. Also the notion of U- equivalently open subsets of a U-equivalence space and U-equivalently open functions are studied. Finally, equivalently uniformisable topological spaces are considered.

  11. Correspondences. Equivalence relations

    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

  12. A high-precision pulse-width modulator source

    A novel high-resolution pulse-width modulator (PWM) is being developed for a new digital regulator for the Advanced Photon Source power converters. The circuit features 82-ps setability over an 80-(micro)s range. Our application requires a 50-(micro)s fill-scale range; therefore the 82-ps setability is equivalent to better than 19 bits. The circuit is presently implemented as a VME module and is an integral part of the digital regulator prototype. The design concept and performance results will be presented

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

    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 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.

  14. Optically thick line widths in pyrotechnic flares

    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.

  15. Establishing Substantial Equivalence: Metabolomics

    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.

  16. Computational study on reliability of sheath width measurement by the cutoff probe in low pressure plasmas

    Recently, the technique for measurement of the sheath width by using the cutoff probe and its equivalent circuit model was proposed and conducted experimentally. In this study, we investigate the reliability of this technique based on the computational simulation. The simulation of three-dimensional Finite-Difference Time-Domain reproduces the transmission spectrum of the cutoff probe with an input parameter of sheath width. We measure the sheath width by using the circuit model and calculate the discrepancy between them under various input plasma densities and sheath widths. The results show the acceptable discrepancy under all of the conditions we studied (the largest discrepancy is about  45%). This indicates that the technique for measurement of sheath width around the floating tip of cutoff probe is robust and reliable. A shorter version of this contribution is due to be published in PoS at: 1st EPS conference on Plasma Diagnostics

  17. Equivalence Relations of -Algebra Extensions

    Changguo Wei

    2010-04-01

    In this paper, we consider equivalence relations of *-algebra extensions and describe the relationship between the isomorphism equivalence and the unitary equivalence. We also show that a certain group homomorphism is the obstruction for these equivalence relations to be the same.

  18. EFFECTS OF LEAD WIDTHS AND PITCHES ON RELIABILITY OF QUAD FLAT PACKAGE (QFP) SOLDERED JOINTS

    XUE Songbai; WU Yuxiu; HAN Zongjie; WANG Jianxin

    2007-01-01

    The finite element method(FEM) is used to analyze the effects of lead widths and pitches on reliability of soldered joints. The optimum Simulation for QFP devices is also researched. The results indicate that when the lead pitches are the same, the maximum equivalent stress of the soldered joints increases with the increasing of lead widths, while the reliability of the soldered joints reduces. When the lead widths are the same, the maximum equivalent stress of the soldered joints doesn't decrease completely with the increasing of lead pitches, a minimum value of the maximum equivalent stress values exists in all the curves. Under this condition the maximum equivalent stress of the soldered joints is relatively the least, the reliability of soldered joints is high and the assembly is excellent. The simulating results indicate the best parameter: The lead width is 0.2 mm and lead pitch is 0.3 mm (the distance between two leads is 0.1 mm), which are benefited for the micromation of QFP devices now. The minimum value of the maximum equivalent stress of soldered joints exists while lead width is 0.25 mm and lead pitch is 0.35 mm (the distance between two leads is 0.1 mm), the devices can serve for a long time and the reliability is the highest, the assembly is excellent. The simulating results also indicate the fact that the lead width is 0.15 mm and lead pitch is 0.2 mm maybe the limit of QFP, which is significant for the high lead count and micromation of assembly.

  19. [OIII] emission line as a tracer of star-forming galaxies at high redshifts: Comparison between H$\\alpha$ and [OIII] emitters at $z$=2.23 in HiZELS

    Suzuki, T L; Sobral, D; Khostovan, A A; Hayashi, M; Shimakawa, R; Koyama, Y; Tadaki, K -i; Tanaka, I; Minowa, Y; Yamamoto, M; Smail, I; Best, P N

    2016-01-01

    We investigate the properties of $z$=2.23 H$\\alpha$ and [OIII]$\\lambda$5007 emitters using the narrow-band-selected samples obtained from the High-$z$ Emission Line Survey (HiZELS: Sobral et al. 2013). We construct two samples of the H$\\alpha$ and [OIII] emitters and compare their integrated physical properties. We find that the distribution of stellar masses, dust extinction, star formation rates (SFRs), and specific SFRs, is not statistically different between the two samples. When we separate the full galaxy sample into three subsamples according to the detections of the H$\\alpha$ and/or [OIII] emission lines, most of the sources detected with both H$\\alpha$ and [OIII] show ${\\rm log(sSFR_{UV})}$$\\gtrsim$-9.5. The comparison of the three subsamples suggests that sources with strong [OIII] line emission tend to have the highest star-forming activity out all galaxies that we study. We argue that the [OIII] emission line can be used as a tracer of star-forming galaxies at high redshift, and that it is especia...

  20. A Survey of Local Group Galaxies Currently Forming Stars: III. A Search for Luminous Blue Variables and Other H-alpha Emission-Lined Stars

    Massey, Philip; Olsen, K A G; Hodge, Paul W; Blaha, Cynthia; Jacoby, George H; Smith, R C; Strong, Shay B

    2007-01-01

    We describe a search for H-alpha emission-lined stars in M31, M33, and seven dwarfs in or near the Local Group (IC 10, NGC 6822, WLM, Sextans B, Sextans A, Pegasus and the Phoenix dwarf) using interference filter imaging with the KPNO and CTIO 4-m telescope and Mosaic cameras. The survey is aimed primarily at identifying new Luminous Blue Variables (LBVs) from their spectroscopic similarity to known LBVs, avoiding the bias towards photometric variability, which may require centuries to manifest itself if LBVs go through long quiescent periods. Followup spectroscopy with WIYN confirms that our survey detected a wealth of stars whose spectra are similar to the known LBVs. We "classify" the spectra of known LBVs, and compare these to the spectra of the new LBV candidates. We demonstrate spectacular spectral variability for several of the new LBV candidates, such as AM2, previously classified as a Wolf-Rayet star, which now shows FeI, FeII and Balmer emission lines but neither the NIII 4634,42 nor HeII 4686 emiss...

  1. Statistical Analysis of Filament Features Based on the H{\\alpha} Solar Images from 1988 to 2013 by Computer Automated Detection Method

    Hao, Q; Cao, W; Chen, P F

    2015-01-01

    We improve our filament automated detection method which was proposed in our previous works. It is then applied to process the full disk H$\\alpha$ data mainly obtained by Big Bear Solar Observatory (BBSO) from 1988 to 2013, spanning nearly 3 solar cycles. The butterfly diagrams of the filaments, showing the information of the filament area, spine length, tilt angle, and the barb number, are obtained. The variations of these features with the calendar year and the latitude band are analyzed. The drift velocities of the filaments in different latitude bands are calculated and studied. We also investigate the north-south (N-S) asymmetries of the filament numbers in total and in each subclass classified according to the filament area, spine length, and tilt angle. The latitudinal distribution of the filament number is found to be bimodal. About 80% of all the filaments have tilt angles within [0{\\deg}, 60{\\deg}]. For the filaments within latitudes lower (higher) than 50{\\deg} the northeast (northwest) direction i...

  2. The nature of H-alpha star-forming galaxies at z~0.4 in and around Cl 0939+4713: the environment matters

    Sobral, David; Koyama, Yusei; Darvish, Behnam; Calhau, João; Afonso, Ana; Kodama, Tadayuki; Nakata, Fumiaki

    2016-01-01

    Cluster star-forming galaxies are found to have an excess of Far-Infrared emission relative to H-alpha (Ha), when compared to those in the field, which could be caused by intense AGN activity, dust and/or declining star formation histories. Here we present spectroscopic observations of Ha emitters in the Cl 0939+4713 (Abell 851) super-cluster at z=0.41, using AF2+WYFFOS on the WHT. We measure [OII], Hbeta (Hb), [OIII], Ha and [NII] for a sample of 119 Ha emitters in and around the cluster. We find that 17+-5% of the Ha emitters are AGN, irrespective of environment. For star-forming galaxies, we obtain Balmer decrements, metallicities and ionisation parameters with different methods, individually and by stacking. We find a strong mass-metallicity relation at all environments, with no significant dependence on environment. The ionisation parameter declines with increasing stellar mass for low-mass galaxies. Ha emitters residing in intermediate environments show the highest ionisation parameters (along with high...

  3. Assessment of Pharmaceutical Equivalence: Difference Test or Equivalence Test?

    Lourenço, Felipe R.; Pinto, Terezinha J. A.

    2012-01-01

    Pharmaceutical equivalence is an important step towards the confirmation of similarity and interchangeability among pharmaceutical products, particularly regarding those that will not be tested for bioequivalence. The aim of this paper is to compare traditional difference testing to two one-side equivalence tests in the assessment of pharmaceutical equivalence, by means of equivalence studies between similar, generic and reference products of acyclovir cream, atropine sulfate injection, merop...

  4. Waste Determination Equivalency - 12172

    Freeman, Rebecca D. [Savannah River Remediation (United States)

    2012-07-01

    by the Secretary of Energy in January of 2006 based on proposed processing techniques with the expectation that it could be revised as new processing capabilities became viable. Once signed, however, it became evident that any changes would require lengthy review and another determination signed by the Secretary of Energy. With the maturation of additional salt removal technologies and the extension of the SWPF start-up date, it becomes necessary to define 'equivalency' to the processes laid out in the original determination. For the purposes of SRS, any waste not processed through Interim Salt Processing must be processed through SWPF or an equivalent process, and therefore a clear statement of the requirements for a process to be equivalent to SWPF becomes necessary. (authors)

  5. Spin gated GDR widths at moderate temperatures

    Mukul Ish

    2015-01-01

    Full Text Available We present the evolution of giant dipole resonance (GDR width as a function of angular momentum in the compound nucleus 144Sm in the temperature range of 1.5-2.0 MeV. The high energy γ rays emitted from the decay of excited 144Sm were measured using large NaI detector in coincidence with 4π sum spin spectrometer. GDR widths were found to comply with thermal shape fluctuation model in this temperature range over a wide range of spin. Experimental widths tend to increase rapidly at high angular momentum values.

  6. Establishing Substantial Equivalence: Proteomics

    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.

  7. Bipartite Graphs of Large Clique-Width

    Korpelainen, Nicholas; Lozin, Vadim V.

    Recently, several constructions of bipartite graphs of large clique-width have been discovered in the literature. In the present paper, we propose a general framework for developing such constructions and use it to obtain new results on this topic.

  8. On the Spectrum Width of Wind Waves

    李陆平; 黄培基

    2001-01-01

    Based on the universal expression of wind wave spectra, four commonly used definitions of the spectrum width arere-examined. The results show that the non-dimensional spectrum width can measure the width of non-dimensionalspectra but it does not reflect the developing state of the spectra. The dimensional spectrum width expresses the degree ofconcentration of wave energy of the spectrum in the process of wind wave growth. Tests show that the spectrum widthpresented by Wen et al. can objectively measure the degree of concentration of wave energy of the spectrum, reflect thestate of wind wave growth, and provides a better result for practical application. The rules for definition of the spectrumwidth are discussed.

  9. Equivalent Linkages of Compressor Mechanisms

    Bukac, Hubert

    2014-01-01

    Frequently, the dynamics of a compressor’s mechanism can be simplified and better understood by analyzing compressor’s equivalent linkage. Although the equivalent linkage of a reciprocating piston compressor is well known, the equivalent linkages of other types of compressors are not. For example, it is not well understood that the equivalent linkage of a rolling piston compressor is also the same slider-crank mechanism as the one of a reciprocating piston compressor. The difference between r...

  10. Direct measurement of the W boson width

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

  11. Liesegang patterns : Studies on the width law

    Droz, M.; Magnin, J.; Zrinyi, M.

    1999-01-01

    The so-called "width law" for Liesegang patterns, which states that the positions x_n and widths w_n of bands verify the relation x_n \\sim w_n^{\\alpha} for some \\alpha>0, is investigated both experimentally and theoretically. We provide experimental data exhibiting good evidence for values of \\alpha close to 1. The value \\alpha=1 is supported by theoretical arguments based on a generic model of reaction-diffusion.

  12. Why scalar-tensor equivalent theories are not physically equivalent?

    Sk., Nayem

    2016-01-01

    Whether Jordan's and Einstein's frame descriptions of F(R) theory of gravity are physically equivalent, is a long standing debate. However, none questioned on true mathematical equivalence, since classical field equations may be translated from one frame to the other following a transformation relation. Nevertheless, true mathematical equivalence is only established, if all the mathematical results derived from one frame may be translated to the other. Here we show that, neither Noether equations, nor quantum equations may be translated from one frame to the other. The reason being the momenta can't be translated. This appears to be the cause for dynamical in-equivalence.

  13. The Variable Line Width of Achernar

    Rivinius, Th; Baade, D; Carciofi, A C; Leister, N; Štefl, S

    2016-01-01

    Spectroscopic observations of Achernar over the past decades, have shown the photospheric line width, as measured by the rotational parameter $v \\sin i$, to vary in correlation with the emission activity. Here we present new observations, covering the most recent activity phase, and further archival data collected from the archives. The $v \\sin i$ variation is confirmed. On the basis of the available data it cannot be decided with certainty whether the increased line width precedes the emission activity, i.e. is a signature of the ejection mechanism, or postdates is, which would make it a signature of re-accretion of some of the disk-material. However, the observed evidence leans towards the re-accretion hypothesis. Two further stars showing the effect of variable line width in correlation with emission activity, namely 66 Oph and $\\pi$ Aqr, are presented as well.

  14. Constraints on widths of mixed pentaquark multiplets

    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.

  15. Finite width effects in top quark decays

    Mahlon, G; Mahlon, Gregory; Parke, Stephen

    1994-01-01

    Motivated by evidence that the top quark mass lies near the bWZ threshold, we compute the decay rate for t\\rightarrow bWZ in the Standard Model, including the effects of the finite widths of the W and Z bosons. In the limit where the width effects are negligible, our results disagree with previously published calculations. We also examine the decay t\\rightarrow bWH. Although the widths induce a sizable enhancement near threshold for both decays, we find that the rates are still too small to be observed in the present generation of experiments. This means that detection of either mode in one of these experiments would be a signal of new physics.

  16. 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

    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 ...

  17. Measurement of the invisible W width

    The results of the W pair production cross section measurements at the LEP II experiments are used to obtain a measurement of the invisible decay width of the W boson. Such an invisible decay width, resulting from W decay channels that have event signatures that are not consistent with any Standard Model decay, would lower the observed cross section compared to that of the Standard Model. From the LEP combined result from the 183 GeV data gathered in 1997, we obtain an upper limit of 45 MeV at 95% CL. (author)

  18. Effective spectrum width of the synchrotron radiation

    Bagrov, V. G., E-mail: bagrov@phys.tsu.ru [Department of Physics, Tomsk State University, Tomsk (Russian Federation); Institute of High Current Electronics, SB RAS, Tomsk (Russian Federation); Gitman, D. M., E-mail: gitman@if.usp.br [Department of Physics, Tomsk State University, Tomsk (Russian Federation); Institute of Physics, University of São Paulo, São Paulo (Brazil); P.N.Lebedev Physical Institute, Moscow (Russian Federation); Levin, A. D., E-mail: alevin@if.usp.br [Institute of Physics, University of São Paulo, São Paulo (Brazil); Loginov, A. S.; Saprykin, A. D. [Department of Physics, Tomsk State University, Tomsk (Russian Federation)

    2015-11-25

    For an exact quantitative description of spectral properties of synchrotron radiation (SR), the concept of effective width of the spectrum is introduced. In the most interesting case, which corresponds to the ultrarelativistic limit of SR, the effective width of the spectrum is calculated for the polarization components, and new physically important quantitative information on the structure of spectral distributions is obtained. For the first time, the spectral distribution for the circular polarization component of the SR for the upper half-space is obtained within classical theory.

  19. High Fin Width Mosfet Using Gaa Structure

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

    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 sub threshold 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 ...

  20. High Fin Width Mosfet Using Gaa Structure

    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.

  1. High Fin Width Mosfet Using Gaa Structure

    S.L.Tripathi

    2012-10-01

    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 sub threshold 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.

  2. On equivalence and bioequivalence testing

    Ocaña, Jordi; Sánchez, M. Pilar; Sánchez, Álex; Carrasco, Josep Lluís

    2008-01-01

    Equivalence testing is the natural approach to many statistical problems. First, its main application, bioequivalence testing, is reviewed. The basic concepts of bioequivalence testing (2×2 crossover designs, TOST, interval inclusion principle, etc.) and its problems (TOST biased character, the carryover problem, etc.) are considered. Next, equivalence testing is discussed more generally. Some applications and methods are reviewed and the relation of equivalence testing and distance-based...

  3. Testing statistical hypotheses of equivalence

    Wellek, Stefan

    2010-01-01

    Equivalence testing has grown significantly in importance over the last two decades, especially as its relevance to a variety of applications has become understood. Yet published work on the general methodology remains scattered in specialists' journals, and for the most part, it focuses on the relatively narrow topic of bioequivalence assessment.With a far broader perspective, Testing Statistical Hypotheses of Equivalence provides the first comprehensive treatment of statistical equivalence testing. The author addresses a spectrum of specific, two-sided equivalence testing problems, from the

  4. Radiative width of the rho- meson

    The excitation of high-energy pions in the nuclear Coulomb field has been investigated. The data, analyzed assuming the presence of both electromagnetic and strong contributions to coherent production of π-π0 systems, yield a decay width for rho- → π-γ of 67 +- 7 keV

  5. Theoretical determination of etab's electromagnetic decay width

    Fabiano, N

    2003-01-01

    We discuss the theoretical predictions for the two photon decay width of the pseudoscalar etab meson. Predictions from potential models are examined. It is found that various models are in good agreement with each other. Results for etab are also compared with those from Upsilon data through the NRQCD procedure.

  6. Reflections on Equivalence in Translation

    王皓

    2011-01-01

    The comparison of texts in different languages inevitably involves a theory of equivalence.To shed as much as possible light on theories and writings that have dealt with the notion of equivalence,this essay attempts to present a few in-depth reflections

  7. Matching of equivalent field regions

    Appel-Hansen, Jørgen; Rengarajan, S.B.

    2005-01-01

    In aperture problems, integral equations for equivalent currents are often found by enforcing matching of equivalent fields. The enforcement is made in the aperture surface region adjoining the two volumes on each side of the aperture. In the case of an aperture in a planar perfectly conducting s...

  8. Unitary equivalence of quantum walks

    Highlights: • We have found unitary equivalent classes in coined quantum walks. • A single parameter family of coin operators is sufficient to realize all simple one-dimensional quantum walks. • Electric quantum walks are unitarily equivalent to time dependent quantum walks. - Abstract: A simple coined quantum walk in one dimension can be characterized by a SU(2) operator with three parameters which represents the coin toss. However, different such coin toss operators lead to equivalent dynamics of the quantum walker. In this manuscript we present the unitary equivalence classes of quantum walks and show that all the nonequivalent quantum walks can be distinguished by a single parameter. Moreover, we argue that the electric quantum walks are equivalent to quantum walks with time dependent coin toss operator

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

    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

  10. Accurate valence band width of diamond

    An accurate width is determined for the valence band of diamond by imaging photoelectron momentum distributions for a variety of initial- and final-state energies. The experimental result of 23.0±0.2 eV2 agrees well with first-principles quasiparticle calculations (23.0 and 22.88 eV) and significantly exceeds the local-density-functional width, 21.5±0.2 eV2. This difference quantifies effects of creating an excited hole state (with associated many-body effects) in a band measurement vs studying ground-state properties treated by local-density-functional calculations. copyright 1997 The American Physical Society

  11. The Width of the Colour Flux Tube

    Caselle, M.; F. Gliozzi; Magnea, U.; Vinti, S.

    1994-01-01

    We discuss and rederive in a general way the logarithmic growth of the mean squared width of the colour flux tube as a function of the interquark separation. Recent data on 3D $Z_2$ gauge theory, combined with high precision data on the interface physics of the 3D Ising model fit nicely this behaviour over a range of more than two orders of magnitude.

  12. Radiative widths of K and rho mesons

    The dissociation of K and π mesons in the nuclear Coulomb field has been studied. Results are: GAMMA(rho→πγ) = 67 +- 7 KeV., GAMMA(K*(890)→Kπ) = 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

  13. LEP hadronic Z0 partial widths

    The experimental situation on hadronic Z0 partial widths at LEP is reviewed. In the absence of recent results on light quarks, only new data concerning Z0 → b b bar and Z0 → cc bar are considered. A LEP average value of Rb (with a 1% precision) implying low top quark mass or new phenomena within the Standard Model framework is presented. A slight deviation of Rb from the Standard Model value is observed. 6 figs., 18 refs

  14. Are There Any Good Digraph Width Measures?

    Ganian, Robert; Hliněný, Petr; Kneis, Joachim; Meister, Daniel; Obdržálek, Jan; Rossmanith, Peter; Sikdar, Somnath

    Several width measures for digraphs have been proposed in the last few years. However, none of them possess all the "nice" properties of treewidth, namely, (1) being algorithmically useful, that is, admitting polynomial-time algorithms for a large class of problems on digraphs of bounded width; and (2) having nice structural properties such as being monotone under taking subdigraphs and some form of arc contractions. As for (1), MSO1 is the least common denominator of all reasonably expressive logical languages that can speak about the edge/arc relation on the vertex set, and so it is quite natural to demand efficient solvability of all MSO1-definable problems in this context. (2) is a necessary condition for a width measure to be characterizable by some version of the cops-and-robber game characterizing treewidth. More specifically, we introduce a notion of a directed topological minor and argue that it is the weakest useful notion of minors for digraphs in this context. Our main result states that any reasonable digraph measure that is algorithmically useful and structurally nice cannot be substantially different from the treewidth of the underlying undirected graph.

  15. Aptitude test and classification of materials with class width of statistically evaluated distinction

    Classification into classes of statistically evaluated distinction is an appropriate means of assigning various materials properties simply and quickly into the relevant groups of being equivalent or different. This information, however, is subject to statistical uncertainties due to the relatively small number of samples used for materials properties testing; the large variety of materials properties modify the information on possible differences. One factor to be taken into account in determining the class width is a sufficient probability by which a difference between two materials properties can be stated when the average sample data are differing by one or more class widths. For this case, formulas for determining the required class widths, derived by a test well-known in statistical mathematics, are presented in this paper and described by numerical examples. (orig./RW)

  16. Aptitude test and classification of materials with class width of statistically evaluated distinction

    Struck, W.

    1982-08-01

    Classification into classes of statistically evaluated distinction is an appropriate means of assigning various materials properties simply and quickly into the relevant groups of being equivalent or different. This information, however, is subject to statistical uncertainties due to the relatively small number of samples used for materials properties testing; the large variety of materials properties modify the information on possible differences. One factor to be taken into account in determining the class width is a sufficient probability by which a difference between two materials properties can be stated when the average sample data are differing by one or more class widths. For this case, formulas for determining the required class widths, derived by a test well-known in statistical mathematics, are presented in this paper and described by numerical examples.

  17. ECC water spreading width for flat plate

    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 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

  18. Tissue Engineered Human Skin Equivalents

    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...

  19. Egalitarian Equivalence under Asymmetric Information

    Geoffroy de Clippel; David Pérez-Castrillo and David Wettstein

    2015-01-01

    We propose a definition of egalitarian equivalence that extends Pazner and Schmeidler's (1978) concept to environments with incomplete information. If every feasible allocation rule can be implemented by an incentive compatible mechanism (as, for instance, in the case of non-exclusive information), then interim egalitarian equivalence and interim incentive efficiency remain compatible, as they were under complete information. When incentive constraints are more restrictive, on the other hand,...

  20. Egalitarian equivalence under asymmetric information

    DE CLIPPEL, Geoffroy; Pérez-Castrillo, David; WETTSTEIN, David

    2010-01-01

    We propose a definition of egalitarian equivalence that extends Pazner and Schmeidler's (1978) concept to environments with incomplete information. If every feasible allocation rule can be implemented by an incentive compatible mechanism (as, for instance, in the case of non-exclusive information), then interim egalitarian equivalence and interim incentive efficiency remain compatible, as they were under complete information. When incentive constraints are more restrictive, on the other hand,...

  1. Equivalence translation of phraseological synonyms.

    Yashchuk, Olena

    2014-01-01

    This article is devoted to phraseological English synonyms, interchangeability and translation equivalence. This paper examines the state of the phenomenon of synonymy in phraseology at present, classifies phraseological units and phraseological synonyms in particular, common translation techniques of idiomatic synonyms, according to different levels of equivalence. The scientific relevance of the work is a synthesis of the linguistic nature of phraseological synonyms, as well as organizing m...

  2. Using tissue equivalent proportional counters to determine dose equivalent

    Tissue equivalent proportional counters (TEPCs) have been used in the laboratory for over 30 years to determine neutron dose in mixed radiation fields, but they are seldom used by operational health physicists. But a number of TEPC-based instruments are being developed in Europe and in the United States. The purpose of this paper is: to introduce operational health physicists to tissue equivalent proportional counters, to examine some of the algorithms used to convert data from TEPCs into dose equivalent, to examine how TEPC measurements meet the requirements of DOE Order 5480.11 (DOE 1988) and 10CFR20, and to examine some of the TEPC-based instruments that are available. Many operational health physicists are not familiar with the concept of microdosimetry and the specialized terms that are used in analyzing the data from TEPCs, so a brief discussion is included. At present, quality factors are defined in terms of linear energy transfer, but TEPCs measure lineal energy

  3. Morita Equivalence for Factorisable Semigroups

    Yu Qun CHEN; K. P. SHUM

    2001-01-01

    Recall that the semigroups S and R are said to be strongly Morita equivalent if there exists a unitary Morita context (S,R,S PR,RQs, <, []) with < and [] surjective. For a factorisable semigroup S, we denote s = {(s1, s2) ∈ S× S | ss1 =ss2,s ∈ S}, S' = S/s and US-FAct= {sM ∈S- Act|SM = M and SHoms(S, M) ≌ M}. We show that, for factorisable semigroups S and R, the categories US-FAct and UR-FAct are equivalent if and only if the semigroups S' and R' are strongly Morita equivalent. Some conditions for a factorisable semigroup to be strongly Morita equivalent to a sandwich semigroup, local units semigroup, monoid and group separately are also given. Moreover, we show that a semigroup S is completely simple if and only if S is strongly Morita equivalent to a group and for any index set I, S SHoms(S,Ⅱi∈ S)→Ⅱi∈S, s t·f→(st)f is an S-isomorphism.

  4. Joint H-alpha and X-ray Observations of Massive X-ray Binaries. I. The B-Supergiant System LS I +65 010 = 2S 0114+650

    Grundstrom, E D; Gies, D R; Huang, W; McSwain, M V; Raghavan, D; Riddle, R L; Subasavage, J P; Wingert, D W; Levine, A M; Remillard, R A

    2006-01-01

    We report on a three year spectroscopic monitoring program of the H-alpha emission in the massive X-ray binary LS I +65 010 = 2S 0114+650, which consists of a B-supergiant and a slowly rotating X-ray pulsar. We present revised orbital elements that yield a period of P=11.5983 +/- 0.0006 d and confirm that the orbit has a non-zero eccentricity e=0.18 +/- 0.05. The H-alpha emission profile is formed in the base of the wind of the B-supergiant primary, and we show how this spectral feature varies on timescales that are probably related to the rotational period of the B-supergiant. We also examine the X-ray fluxes from the Rossi X-ray Timing Explorer All-Sky Monitor instrument, and we show that the X-ray orbital light curve has a maximum at periastron and a minimum at the inferior conjunction of the B-supergiant. We also show that the wind emission strength and the high energy X-ray flux appear to vary in tandem on timescales of approximately a year.

  5. Multi-Wavelength Constraints on the Cosmic Star Formation History from Spectroscopy: the Rest-Frame UV, H-alpha, and Infrared Luminosity Functions at Redshifts 1.9

    Reddy, Naveen A; Pettini, Max; Adelberger, Kurt L; Shapley, Alice E; Erb, Dawn K; Dickinson, Mark

    2007-01-01

    We use a sample of rest-frame UV selected and spectroscopically observed galaxies at redshifts 1.9H-alpha and Spitzer MIPS 24 micron data, to derive the most robust measurements of the rest-frame UV, H-alpha, and infrared (IR) luminosity functions (LFs) at these redshifts. Our sample is by far the largest of its kind, with over 2000 spectroscopic redshifts in the range 1.9

  6. Sievert, gray and dose equivalent.

    Pfalzner, P M

    1983-12-01

    The concepts of physical quantity and physical units of measurement are presented. The relations between quantities, the names and symbols for SI (International System) base units, derived units and special names of SI units are illustrated. From the definition of the radiation quantity dose equivalent, the SI unit for this quantity is shown to be dimensionally identical with the joule per kilogram. The sievert (Sv) is the special (restricted) name for the SI unit of the quantity dose equivalent, with 1 Sv = 1 J/kg. PMID:6668293

  7. Affine varieties with equivalent cylinders

    Yu, JT; Shpilrain, V

    2001-01-01

    A well-known cancellation problem asks when, for two algebraic varieties $V_1, V_2 \\subseteq {\\bf C}^n$, the isomorphism of the cylinders $V_1 \\times {\\bf C}$ and $V_2 \\times {\\bf C}$ implies the isomorphism of $V_1$ and $V_2$. In this paper, we address a related problem: when the equivalence (under an automorphism of ${\\bf C}^{n+1}$) of two cylinders $V_1 \\times {\\bf C}$ and $V_2 \\times {\\bf C}$ implies the equivalence of their bases $V_1$ and $V_2$ under an automorphism of ${\\bf C}^n$? We c...

  8. Detection of Broad H$\\alpha$ Emission Lines in the Late-time Spectra of a Hydrogen-poor Superluminous Supernova

    Yan, Lin; Ofek, E; Gal-Yam, A; Mazzali, P; Perley, D; Vreeswijk, P; Leloudas, G; de Cia, A; Masci, F; Cenko, S B; Cao, Y; Kulkarni, S R; Nugent, P E; Rebbapragada, Umaa D; Woźniak, P R; Yaron, O

    2015-01-01

    iPTF13ehe is a hydrogen-poor superluminous supernova (SLSN) at z=0.3434, with properties similar to SN2007bi. It rises within (83-148)days (rest-frame) to reach a peak bolometric luminosity of 1.3x$10^{44}$erg/s, then decays very slowly at 0.015mag. per day. The measured ejecta velocity is 13000km/s. The inferred explosion characteristics, such as the ejecta mass (67-220$M_\\odot$), the total radiative and kinetic energy ($10^{51}$ & 2x$10^{53}$erg respectively), is typical of SLSN-R events. However, the late-time spectrum taken at +251days reveals a Balmer Halpha emission feature with broad and narrow components, which has never been detected before among other H-poor SLSNe. The broad component has a velocity width of ~4500km/s and has a ~300km/s blue-ward shift relative to the narrow component. We interpret this broad Halpha emission line as the interaction between the supernova ejecta and a H-rich circumstellar medium (CSM) shell, located at a distance of ~4x$10^{16}$cm from the explosion site. This eje...

  9. Direct measurement of the W boson width

    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.

  10. Morita "equivalences" of equivariant torus spectral triples

    Venselaar, Jan Jitse

    2011-01-01

    In general, Morita equivalence of spectral triples need not be a symmetric relation. In this paper, we show that Morita equivalence of spectral triples is an equivalence relation for equivariant torus spectral triples.

  11. Dynamic Wavelet and Equivalent Models

    Boaghe, O.M.; Billings, S A

    1998-01-01

    The representation of nonlinear dynamic wavelet models in the form of an equivalent global model which is valid over the operating range of the system is investigated. The results are used to analyse and interpret the nonlinear wavelet models using non-linear frequency response functions.

  12. Comments on field equivalence principles

    Appel-Hansen, Jørgen

    1987-01-01

    It is pointed Out that often-used arguments based on a short-circuit concept in presentations of field equivalence principles are not correct. An alternative presentation based on the uniqueness theorem is given. It does not contradict the results obtained by using the short-circuit concept but...

  13. Lake Basin Fetch and Maximum Length/Width

    Minnesota Department of Natural Resources — Linear features representing the Fetch, Maximum Length and Maximum Width of a lake basin. Fetch, maximum length and average width are calcuated from the lake...

  14. Pulse-Width Jitter Measurement for Laser Diode Pulses

    TANG Jun-Hua; WANG Yun-Cai

    2006-01-01

    @@ Theoretical analysis and experimental measurement of pulse-width jitter of diode laser pulses are presented. The expression of pulse power spectra with all amplitude jitter, timing jitter and pulse-width jitter is deduced.

  15. EQUIVALENCE VERSUS NON-EQUIVALENCE IN ECONOMIC TRANSLATION

    Cristina, Chifane

    2012-01-01

    Full Text Available This paper aims at highlighting the fact that “equivalence” represents a concept worth revisiting and detailing upon when tackling the translation process of economic texts both from English into Romanian and from Romanian into English. Far from being exhaustive, our analysis will focus upon the problems arising from the lack of equivalence at the word level. Consequently, relevant examples from the economic field will be provided to account for the following types of non-equivalence at word level: culturespecific concepts; the source language concept is not lexicalised in the target language; the source language word is semantically complex; differences in physical and interpersonal perspective; differences in expressive meaning; differences in form; differences in frequency and purpose of using specific forms and the use of loan words in the source text. Likewise, we shall illustrate a number of translation strategies necessary to deal with the afore-mentioned cases of non-equivalence: translation by a more general word (superordinate; translation by a more neutral/less expressive word; translation by cultural substitution; translation using a loan word or loan word plus explanation; translation by paraphrase using a related word; translation by paraphrase using unrelated words; translation by omission and translation by illustration.

  16. Tooth width ratios in crowded and non-crowded dentitions

    Bernabé, E.; Villanueva, KM; Flores-Mir, C

    2004-01-01

    Discrepancies in tooth width ratios could affect the excellence in the finishing of orthodontic cases. This study compares tooth width ratios in crowded and noncrowded dental arches. Tooth widths were measured from 143 dental casts (40 crowded and 33 spaced in male individuals and 43 crowded and 27 spaced in female individuals). Simultaneous crowded or spaced arches were selected. Tooth width measurements were made with a sliding caliper with a Vernier scale neared 0.1 mm. Inter- (0.990) and ...

  17. Influence of γ irradiation on band width of optical fibers

    The effect of band width of the multimode step index fibers under γ irradiation has been investigated. It was found that band width of the optical fibers decreased as irradiation dose increased, and the decrease of band width reached to 60%. The possible cause for the result is discussed

  18. Correlation between Line Width and Line Flux of Double-Peaked Broad Halpha of 3C390.3

    Zhang, XueGuang

    2012-01-01

    In this manuscript, we carefully check the correlation between the line width and the line flux of the double-peaked broad H$\\alpha$ of the well-known mapped AGN 3C390.3, in order to show some further distinctions between double-peaked emitters and normal broad line AGN. Based on the Virialization assumption and the empirical relation about $R_{BLR}$, one strong negative correlation of line parameters of the double-peaked broad lines should be expected for 3C390.3, such as the negative correlation confirmed for the mapped broad line object NGC5548. But, based on the public spectra around 1995 from the AGNWATCH project for 3C390.3, one reliable positive correlation is found. In the context of the proposed theoretical accretion disk model for double-peaked emitters, the unexpected positive correlation can be naturally explained, due to different time delays for inner parts and outer parts of disk-like BLR of 3C390.3. Moreover, the Virialization assumption is checked and found to be still available for 3C390.3. ...

  19. Equivalent Imperfections In Arched Structures

    Dallemule Marian

    2015-09-01

    Full Text Available There are currently three design methods to verify the in-plane buckling of an arched structure: substitute member method, the method of equivalent imperfection with recommendations for arched bridges, and the equivalent unique global and local initial imperfection method (EUGLI, which uses the critical elastic buckling mode as an imperfection. The latter method is included in the EN 1993-1-1 cl. 5.3.2 (11 since 2002; however, to this day it is neither utilized in the design practice nor is it incorporated in ordinary structural analysis software. The main purpose of this article is to show the application of the proposed methods in a step-by-step manner to the numerical example considered and to compare these design methods for various arched structures. Verification of the in-plane buckling of an arch is explained in detail.

  20. Equivalent circuit analysis of sled

    A direct application of equivalent circuit concepts leads to: (1) confirmation of Perry Wilson's SLED (SLAC Linac Energy Doubler) equation; (2) an equation that applies to a SLED device with input and output waveguides of different characteristic impedances; and (3) an equation that results if we demand that no power be lost by reflection from SLED. If the incident voltage is tailored as prescribed by this equation, the cavity voltage tracks the incident voltage and the reflected voltage is zero

  1. Relative exchangeability with equivalence relations

    Crane, Harry; Towsner, Henry

    2016-01-01

    We describe an Aldous--Hoover-type characterization of random relational structures that are exchangeable relative to a fixed structure which may have various equivalence relations. Our main theorem gives the common generalization of the results on relative exchangeability due to Ackerman \\cite{Ackerman2015} and Crane and Towsner \\cite{CraneTowsner2015} and hierarchical exchangeability results due to Austin and Panchenko \\cite{AustinPanchenko2014}.

  2. The Source Equivalence Acceleration Method

    Highlights: • We present a new acceleration method, the Source Equivalence Acceleration Method. • SEAM forms an equivalent coarse group problem for any spatial method. • Equivalence is also formed across different spatial methods and angular quadratures. • Testing is conducted using OpenMOC and performance is compared with CMFD. • Results show that SEAM is preferable for very expensive transport calculations. - Abstract: Fine-group whole-core reactor analysis remains one of the long sought goals of the reactor physics community. Such a detailed analysis is typically too computationally expensive to be realized on anything except the largest of supercomputers. Recondensation using the Discrete Generalized Multigroup (DGM) method, though, offers a relatively cheap alternative to solving the fine group transport problem. DGM, however, suffered from inconsistencies when applied to high-order spatial methods. While an exact spatial recondensation method was developed and provided full spatial consistency with the fine group problem, this approach substantially increased memory requirements for realistic problems. The method described in this paper, called the Source Equivalence Acceleration Method (SEAM), forms a coarse-group problem which preserves the fine-group problem even when using higher order spatial methods. SEAM allows recondensation to converge to the fine-group solution with minimal memory requirements and little additional overhead. This method also provides for consistency when using different spatial methods and angular quadratures between the coarse group and fine group problems. SEAM was implemented in OpenMOC, a 2D MOC code developed at MIT, and its performance tested against Coarse Mesh Finite Difference (CMFD) acceleration on the C5G7 benchmark problem and on a 361 group version of the problem. For extremely expensive transport calculations, SEAM was able to outperform CMFD, resulting in speed-ups of 20–45 relative to the normal power

  3. Motor Equivalence in Speech Production

    Perrier, Pascal; Fuchs, Susanne

    2015-01-01

    International audience The first section provides a description of the concepts of “motor equivalence” and “degrees of freedom”. It is illustrated with a few examples of motor tasks in general and of speech production tasks in particular. In the second section, the methodology used to investigate experimentally motor equivalence phenomena in speech production is presented. It is mainly based on paradigms that perturb the perception-action loop during on-going speech, either by limiting the...

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

    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.

  5. GAP WIDTH STUDY IN LASER BUTT-WELDING

    Gong, Hui; Olsen, Flemming Ove

    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....

  6. Equivalence in Bilingual Lexicography: Criticism and Suggestions*

    Herbert Ernst Wiegand

    2011-01-01

    Abstract: A reminder of general problems in the formation of terminology, as illustrated by theGerman Äquivalence (Eng. equivalence) and äquivalent (Eng. equivalent), is followed by a critical discussionof the concept of equivalence in contrastive lexicology. It is shown that especially the conceptof partial equivalence is contradictory in its different manifestations. Consequently attemptsare made to give a more precise indication of the concept of equivalence in the metalexicograph...

  7. On the Translation Equivalence of Literature Works

    吴娟

    2013-01-01

    As for translation principle,people have different opinions.The principle of equivalent translation maybe is one of the most reasonable ones in today’s translation world in my eyes.This paper focuses on the possibility and the condition to be achieved the biggest equivalence of the semantic,pragmatic and culture in order to get the conclusion that the translation equivalence is the proper principle.Besides,this paper has also discussed the pragmatic equivalence and cultural equivalence.

  8. Blast Wave Characteristics and Equivalency

    Sochet, Isabelle; Schneider, Helmut

    2010-01-01

    The characteristics of blast waves generated by detonation of gas clouds are studies theoretically and validated by both small-scale and large-scale experiments with ethylene-air mixtures of different equivalence ratio. The mixtures were confined in hemispherical or spherical balloons made from thin polyethylene foils of 0.75 m³ and 15 m³ in volume. The detonation of gas mixtures was initiated by a solid explosive. The characteristics of the blast wave in terms of overpressure, impulse and du...

  9. Therapeutic equivalents in clinical practice.

    Benson, M D

    2001-01-01

    With increasing debate over the rising expenses of health care, a variety of cost-saving measures has been attempted over the years. Use of primary care physicians as "gate keepers," reduction in the length of hospital stays, and pushing women toward vaginal birth after Cesarean section have all been utilized despite on going issues with patient satisfaction and even safety. One remarkable success in stretching health-care dollars that has often been overlooked is the prescription of therapeutic equivalents, or generic drugs. Although available on a limited basis for decades, off-brand manufacture of pharmaceuticals with identical active ingredients as those of the branded drug received a large boost through Congressional legislation in 1984 with the Hatch-Waxman Act. "Fast-track" FDA approval was initiated by Congress to introduce competition into the marketplace for drugs whose patients had expired. While giving close scrutiny to the manufacturing process and requiring the same level of regulatory supervision for factors such as bioavailability and shelf life, the Hatch-Waxman Act removed the burden and expense from generic manufacturers of proving the safety and efficacy all over again of a previously FDA-approved drug. With less than a 20% market share of all prescribed drugs in 1984, the generic drug industry has captured roughly 44% of the market in recent years while accounting for only 8% of expenditures on prescription medication. The prescription of therapeutic equivalents is one method of keeping health care costs down without compromising patient satisfaction or safety. PMID:11374660

  10. Width effects on hydrodynamics of pendulum wave energy converter

    王冬姣; 邱守强; 叶家玮

    2014-01-01

    Based on two- and three-dimensional potential flow theories, the width effects on the hydrodynamics of a bottom-hinged trapezoidal pendulum wave energy converter are discussed. The two-dimensional eigenfunction expansion method is used to obtain the diffraction and radiation solutions when the converter width tends to be infinity. The trapezoidal section of the converter is approximated by a rectangular section for simplification. The nonlinear viscous damping effects are accounted for by including a drag term in the two- and three-dimensional methods. It is found that the three-dimensional results are in good agreement with the two-dimensional results when the converter width becomes larger, especially when the converter width is infinity, which shows that both of the methods are reasonable. Meantime, it is also found that the peak value of the conversion efficiency decreases as the converter width increases in short wave periods while increases when the converter width increases in long wave periods.

  11. Biologic width and its importance in periodontal and restorative dentistry

    Babitha Nugala; B B Santosh Kumar; S Sahitya; P Mohana Krishna

    2012-01-01

    An adequate understanding of the relationship between periodontal tissues and restorative dentistry is paramount to ensure adequate form, function, esthetics and comfort of the dentition. While most clinicians are aware of this important relationship, uncertainty remains regarding specific concepts such as biologic width, its maintenance and applications of crown lengthening in cases of biologic width violation. Relevant publications regarding biologic width, its violation and management were...

  12. Crack Width Analysis of Steel Fiber Reinforced Concrete Elements

    Darius Ulbinas

    2011-04-01

    Full Text Available The article investigates the effectiveness of steel fiber reinforcement in RC concrete members in regard to ordinary reinforcement. The advantages and disadvantages of different shapes of steel fibers are discussed. The algorithm for calculating crack width based on EC2 and Rilem methodologies is presented. A comparison of theoretical and experimental crack widths has been performed. The relative errors of crack width predictions at different load levels were defined.Article in Lithuanian

  13. Crack Width Analysis of Steel Fiber Reinforced Concrete Elements

    Darius Ulbinas; Gintaris Kaklauskas

    2011-01-01

    The article investigates the effectiveness of steel fiber reinforcement in RC concrete members in regard to ordinary reinforcement. The advantages and disadvantages of different shapes of steel fibers are discussed. The algorithm for calculating crack width based on EC2 and Rilem methodologies is presented. A comparison of theoretical and experimental crack widths has been performed. The relative errors of crack width predictions at different load levels were defined.Article in Lithuanian

  14. The significance of biometric parameters in determining anterior teeth width

    Strajnić 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.

  15. A Statistical Approach for Obtaining the Controlled Woven Fabric Width

    Shaker Khubab

    2015-12-01

    Full Text Available A common problem faced in fabric manufacturing is the production of inconsistent fabric width on shuttleless looms in spite of the same fabric specifications. Weft-wise crimp controls the fabric width and it depends on a number of factors, including warp tension, temple type, fabric take-up pressing tension and loom working width. The aim of this study is to investigate the effect of these parameters on the fabric width produced. Taguchi’s orthogonal design was used to optimise the weaving parameters for obtaining controlled fabric width. On the basis of signal to noise ratios, it could be concluded that controlled fabric width could be produced using medium temple type and intense take-up pressing tension at relatively lower warp tension and smaller loom working width. The analysis of variance revealed that temple needle size was the most significant factor affecting the fabric width, followed by loom working width and warp tension, whereas take-up pressing tension was least significant of all the factors investigated in the study.

  16. Biologic width and its importance in periodontal and restorative dentistry

    Babitha Nugala

    2012-01-01

    Full Text Available An adequate understanding of the relationship between periodontal tissues and restorative dentistry is paramount to ensure adequate form, function, esthetics and comfort of the dentition. While most clinicians are aware of this important relationship, uncertainty remains regarding specific concepts such as biologic width, its maintenance and applications of crown lengthening in cases of biologic width violation. Relevant publications regarding biologic width, its violation and management were identified up to August 2011 using manual and electronic database search in Medline, Embase, Directory of Open Access Journals and Google Scholar. This review discusses the concept of biologic width around tooth and its relationship to periodontal health and restorative dentistry.

  17. Biologic width and its importance in periodontal and restorative dentistry.

    Nugala, Babitha; Kumar, Bb Santosh; Sahitya, S; Krishna, P Mohana

    2012-01-01

    An adequate understanding of the relationship between periodontal tissues and restorative dentistry is paramount to ensure adequate form, function, esthetics and comfort of the dentition. While most clinicians are aware of this important relationship, uncertainty remains regarding specific concepts such as biologic width, its maintenance and applications of crown lengthening in cases of biologic width violation. Relevant publications regarding biologic width, its violation and management were identified up to August 2011 using manual and electronic database search in Medline, Embase, Directory of Open Access Journals and Google Scholar. This review discusses the concept of biologic width around tooth and its relationship to periodontal health and restorative dentistry. PMID:22368328

  18. Einstein's equivalence principle in cosmology

    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...

  19. Ensemble Equivalence for Distinguishable Particles

    Antonio Fernández-Peralta

    2016-07-01

    Full Text Available Statistics of distinguishable particles has become relevant in systems of colloidal particles and in the context of applications of statistical mechanics to complex networks. In this paper, we present evidence that a commonly used expression for the partition function of a system of distinguishable particles leads to huge fluctuations of the number of particles in the grand canonical ensemble and, consequently, to nonequivalence of statistical ensembles. We will show that the alternative definition of the partition function including, naturally, Boltzmann’s correct counting factor for distinguishable particles solves the problem and restores ensemble equivalence. Finally, we also show that this choice for the partition function does not produce any inconsistency for a system of distinguishable localized particles, where the monoparticular partition function is not extensive.

  20. Expanding the Interaction Equivalency Theorem

    Brenda Cecilia Padilla Rodriguez

    2015-06-01

    Full Text Available Although interaction is recognised as a key element for learning, its incorporation in online courses can be challenging. The interaction equivalency theorem provides guidelines: Meaningful learning can be supported as long as one of three types of interactions (learner-content, learner-teacher and learner-learner is present at a high level. This study sought to apply this theorem to the corporate sector, and to expand it to include other indicators of course effectiveness: satisfaction, knowledge transfer, business results and return on expectations. A large Mexican organisation participated in this research, with 146 learners, 30 teachers and 3 academic assistants. Three versions of an online course were designed, each emphasising a different type of interaction. Data were collected through surveys, exams, observations, activity logs, think aloud protocols and sales records. All course versions yielded high levels of effectiveness, in terms of satisfaction, learning and return on expectations. Yet, course design did not dictate the types of interactions in which students engaged within the courses. Findings suggest that the interaction equivalency theorem can be reformulated as follows: In corporate settings, an online course can be effective in terms of satisfaction, learning, knowledge transfer, business results and return on expectations, as long as (a at least one of three types of interaction (learner-content, learner-teacher or learner-learner features prominently in the design of the course, and (b course delivery is consistent with the chosen type of interaction. Focusing on only one type of interaction carries a high risk of confusion, disengagement or missed learning opportunities, which can be managed by incorporating other forms of interactions.

  1. From body burden to effective dose equivalent

    The necessary data to calculate the effective committed dose equivalent and the effective dose-equivalent rate from measured body burdens are presented. Both ingestion and inhalation intakes are considered, for single intake as well as for continuous exposure

  2. 20 CFR 404.1526 - Medical equivalence.

    2010-04-01

    ... medical equivalence. For cases in the disability hearing process or otherwise decided by a disability hearing officer, the responsibility for determining medical equivalence rests with either the disability hearing officer or, if the disability hearing officer's reconsideration determination is changed...

  3. Equivalence in Logic-Based Argumentation

    Amgoud, Leila; Besnard, Philippe; Vesic, Srdjan

    2014-01-01

    International audience This paper investigates when two abstract logic-based argumentation systems are equivalent. It defines various equivalence criteria, investigates the links between them, and identifies cases where two systems are equivalent with respect to each of the proposed criteria. In particular, it shows that under some reasonable conditions on the logic underlying an argumentation system, the latter has an equivalent finite subsystem, called core. This core constitutes a thres...

  4. Measuring Slit Width and Separation in a Diffraction Experiment

    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…

  5. Quantifying River Widths of North America from Satellite Imagery

    Allen, G. H.; Pavelsky, T.; Miller, Z.

    2013-12-01

    River width is a fundamental predictor variable in many hydrologic, geomorphic, and biogeochemical models, yet current large-scale models rely on theoretical hydraulic geometry relationships that do not fully capture natural variability in river form. Here we present the first high-resolution dataset of long-term mean width of North American rivers wider than 30 m. The dataset contains 7.93 million georeferenced width measurements derived from Landsat TM and ETM+ imagery that were acquired when rivers were most likely to be at mean discharge. We built the dataset by developing an automated procedure that selects and downloads raw imagery, creates cloud-free normalized difference water index images, histogram balances and mosaics them together, and produces a water mask using a dynamic water-land threshold technique. We then visually inspected and corrected the mask for errors and used RivWidth software to calculate river width at each river centerline pixel. We validated our dataset using >1000 United States Geological Survey and Water Survey of Canada in situ gauge station measurements. Error analysis shows a robust relationship between the remotely sensed widths and in situ gauge measurements with an r 2 = 0.86 (Spearman's = 0.81) and a mean absolute error of 27.5 m. We find that North American river widths lie on logarithmic frequency curve with some notable exceptions at widths SWOT) satellite mission.

  6. Crack widths in concrete with fibers and main reinforcement

    Christensen, Frede; Ulfkjær, Jens Peder; Brincker, Rune

    The main object of the research work presented in this paper is to establish design tools for concrete structures where main reinforcement is combined with addition of short discrete steel fibers. The work is concerned with calculating and measuring crack widths in structural elements subjected to...... bending load. Thus, the aim of the work is to enable engineers to calculate crack widths for flexural concrete members and analyze how different combinations of amounts of fibers and amounts of main reinforcement can meet a given maximum crack width requirement. A mathematical model including the...... ductility of the fiber reinforced concrete (FRC) is set up and experimental work is conducted in order to verify the crack width model. The ductility of the FRC is taken into account by using the stress crack width relation. The constitutive model for the FRC is based on the idea that the initial part of...

  7. Research on Fairway Width Design in Curved Bridge Waters Channel

    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.

  8. Violation of the gauge equivalence

    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...

  9. Equivalence Principle in Chameleon Models

    Kraiselburd, Lucila; Salgado, Marcelo; Sudarsky, Daniel; Vucetich, Héctor

    2015-01-01

    Most theories that predict time and(or) space variation of fundamental constants also predict violations of the Weak Equivalence Principle (WEP). Khoury and Weltman proposed the chameleon model in 2004 and claimed that this model avoids experimental bounds on the WEP. In this paper we present a contrasting view based on the analysis of the force between two bodies induced by the chameleon field using a particular approach in which the field due to both the large and the small bodies is obtained by appropriate series expansions in the various regions of interest and the corresponding matching conditions. We found that resulting force depends on the test body\\'{}s composition even when the chameleon coupling constants $\\beta_{i}$ are universal. In particular, we compared the resulting differential acceleration of test bodies made of Be and Al with the corresponding bounds obtained from E\\"otv\\"os type experiments and find that the predictions of the chameleon model are, in general, various orders of magnitude a...

  10. Behavioural equivalence for infinite systems - Partially decidable!

    Sunesen, Kim; Nielsen, Mogens

    1996-01-01

    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......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...

  11. Equivalent Simplification Method of Micro-Grid

    Cai Changchun

    2013-09-01

    Full Text Available 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 performed for the test of the equivalent model of micro-grid. The simulation results show that the equivalent model of micro-grid is effective, and the dynamic of equivalent model is similar with the detailed model of micro-grid. The equivalent simplification method for the micro-grid network and distributed components is suitable for the study of micro-grid.  

  12. 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

    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....

  13. Solar Imagery - GONG (H-alpha)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Global Oscillation Network Group (GONG) is a network of 6 globally-spaced solar observatories that the NOAA Space Weather Prediction Center uses to monitor the...

  14. Calculations of a wideband metamaterial absorber using equivalent medium theory

    Huang, Xiaojun; Yang, Helin; Wang, Danqi; Yu, Shengqing; Lou, Yanchao; Guo, Ling

    2016-08-01

    Metamaterial absorbers (MMAs) have drawn increasing attention in many areas due to the fact that they can achieve electromagnetic (EM) waves with unity absorptivity. We demonstrate the design, simulation, experiment and calculation of a wideband MMA based on a loaded double-square-loop (DSL) array of chip resisters. For a normal incidence EM wave, the simulated results show that the absorption of the full width at half maximum is about 9.1 GHz, and the relative bandwidth is 87.1%. Experimental results are in agreement with the simulations. More importantly, equivalent medium theory (EMT) is utilized to calculate the absorptions of the DSL MMA, and the calculated absorptions based on EMT agree with the simulated and measured results. The method based on EMT provides a new way to analysis the mechanism of MMAs.

  15. The effect of buffer zone width on biodiversity

    Navntoft, Søren; Sigsgaard, Lene; Kristensen, Kristian; Esbjerg, P

    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...

  16. Nightside studies of coherent HF Radar spectral width behaviour

    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

  17. In-medium width of the η' meson

    Niblaeus, Carl

    2013-01-01

    In this master’s thesis the width of the  meson is studied as a function of temperature. We consider a background medium consisting of a pion gas and assume a vanishing net baryon chemical potential. The width is obtained in the framework of large  chiral perturbation theory and we consider terms up to next-to-leading order in the effective Lagrangian. We use a low-density approximation to calculate the width increase due to scattering with pions from the heat bath. The results suggest that t...

  18. Pulse-width compression based on photonic crystal fiber

    WANG Jing; WANG Zhen-li; SHI Yan-mei

    2006-01-01

    According to the characteristics of high-order solitons,compressed picosecond pulses are numerically simulated in the photonic crystal fiber (PCF),by means of split-step Fourier method. The results show that,PCF enables input pulse with lower peak power to form high-order solitons for the purpose of femtosecond pulse-width compression. For example,60- femtosecond pulse width was made for 1-ps initial pulse width only over the distance of 2.2 m.Besides,shorter optimum fiber length for compression and higher compression ratio could be obtained on the premise of pre-chirp technique.

  19. Equivalence in Bilingual Lexicography: Criticism and Suggestions*

    Herbert Ernst Wiegand

    2011-10-01

    Full Text Available

    Abstract: A reminder of general problems in the formation of terminology, as illustrated by theGerman Äquivalence (Eng. equivalence and äquivalent (Eng. equivalent, is followed by a critical discussionof the concept of equivalence in contrastive lexicology. It is shown that especially the conceptof partial equivalence is contradictory in its different manifestations. Consequently attemptsare made to give a more precise indication of the concept of equivalence in the metalexicography,with regard to the domain of the nominal lexicon. The problems of especially the metalexicographicconcept of partial equivalence as well as that of divergence are fundamentally expounded.In conclusion the direction is indicated to find more appropriate metalexicographic versions of theconcept of equivalence.

    Keywords: EQUIVALENCE, LEXICOGRAPHIC EQUIVALENT, PARTIAL EQUIVALENCE,CONGRUENCE, DIVERGENCE, CONVERGENCE, POLYDIVERGENCE, SYNTAGM-EQUIVALENCE,ZERO EQUIVALENCE, CORRESPONDENCE

    Abstrakt: Äquivalenz in der zweisprachigen Lexikographie: Kritik und Vorschläge.Nachdem an allgemeine Probleme der Begriffsbildung am Beispiel von dt. Äquivalenzund dt. äquivalent erinnert wurde, wird zunächst auf Äquivalenzbegriffe in der kontrastiven Lexikologiekritisch eingegangen. Es wird gezeigt, dass insbesondere der Begriff der partiellen Äquivalenzin seinen verschiedenen Ausprägungen widersprüchlich ist. Sodann werden Präzisierungenzu den Äquivalenzbegriffen in der Metalexikographie versucht, die sich auf den Bereich der Nennlexikbeziehen. Insbesondere der metalexikographische Begriff der partiellen Äquivalenz sowie derder Divergenz werden grundsätzlich problematisiert. In welche Richtung man gehen kann, umangemessenere metalexikographische Fassungen des Äquivalenzbegriffs zu finden, wird abschließendangedeutet.

    Stichwörter: ÄQUIVALENZ, LEXIKOGRAPHISCHES ÄQUIVALENT, PARTIELLE ÄQUIVALENZ,KONGRUENZ, DIVERGENZ, KONVERGENZ, POLYDIVERGENZ

  20. The Complexity of Identifying Large Equivalence Classes

    Skyum, Sven; Frandsen, Gudmund Skovbjerg; Miltersen, Peter Bro;

    1999-01-01

    We prove that at least 3k−4/k(2k−3)(n/2) – O(k)equivalence tests and no more than 2/k (n/2) + O(n) equivalence tests are needed in the worst case to identify the equivalence classes with at least k members in set of n elements. The upper bound is an improvement by a factor 2 compared to known res...

  1. Better Polynomial Algorithms on Graphs of Bounded Rank-Width

    Ganian, Robert; Hliněný, Petr

    Although there exist many polynomial algorithms for NP-hard problems running on a bounded clique-width expression of the input graph, there exists only little comparable work on such algorithms for rank-width. We believe that one reason for this is the somewhat obscure and hard-to-grasp nature of rank-decompositions. Nevertheless, strong arguments for using the rank-width parameter have been given by recent formalisms independently developed by Courcelle and Kanté, by the authors, and by Bui-Xuan et al. This article focuses on designing formally clean and understandable "pseudopolynomial" (XP) algorithms solving "hard" problems (non-FPT) on graphs of bounded rank-width. Those include computing the chromatic number and polynomial or testing the Hamiltonicity of a graph and are extendable to many other problems.

  2. Possible Gigantic Variations on the Width of Viscoelastic Fingers

    Poire, E C; Poire, Eugenia Corvera

    2002-01-01

    We analyze the effect of frequency on the width of a single finger displacing a viscoelastic fluid. We derive a generalized Darcy's law in the frequency domain for a linear viscoelastic fluid flowing in a Hele Shaw cell. This leads to an analytic expression for the dynamic permeability that has maxima which are several orders of magnitude larger than the static permeability. We then follow an argument of de Gennes to obtain the smallest possible finger width when viscoelasticity is important. Using this, and a conservation law, we obtain a lowest bound for the width of a single finger displacing a viscoelastic fluid. Our results indicate that when a small amplitude signal of the frequency that maximizes the permeability is overimposed to a constant pressure drop, gigantic variations are obtained for the finger width.

  3. Systematics of oscillatory behavior in hadronic masses and widths

    Tatischeff, Boris

    2016-01-01

    A systematic study of hadron masses and widths shows regular oscillations that can be fitted by a simple cosine function. This property can be observed when the difference between adjacent masses of each family is plotted versus the mean mass.

  4. Calculation of the decay width of decuplet baryons

    Alexandrou, Constantia; Petschlies, Marcus; Pochinsky, Andrew V; Syritsyn, Sergey S

    2015-01-01

    We calculate the coupling constant and decay width of the decuplet to octet baryon transitions in lattice QCD using the transfer matrix method. The transition amplitude is related to the coupling constant and via the Fermi's Golden Rule to the decay width. The method is applicable for near-degeneracy of the energy levels of initial and final states and, when this condition is fulfilled, yields a good estimate of the decay width. We present results using a hybrid action with domain wall valence quarks on a staggered sea with $350$ MeV pion mass as well as for a domain wall fermion action with $180$ MeV pion mass. We find $\\Gamma\\left( \\Delta \\to \\pi\\,N \\right) = 119\\,( 8)\\,( 8)$ MeV for the transition of Delta to pion-nucleon within the unitary domain wall setup. We also report values for the decay widths of the $\\Sigma^*$ and $\\Xi*$ baryons.

  5. Optical waveguide device with an adiabatically-varying width

    Watts; Michael R. , Nielson; Gregory N.

    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.

  6. The effective theory of Borel equivalence relations

    Fokina, E.B.; Friedman, S.-D.; Törnquist, Asger Dag

    2010-01-01

    The study of Borel equivalence relations under Borel reducibility has developed into an important area of descriptive set theory. The dichotomies of Silver [20] and Harrington, Kechris and Louveau [6] show that with respect to Borel reducibility, any Borel equivalence relation strictly above...... equality on ω is above equality on P (ω), the power set of ω, and any Borel equivalence relation strictly above equality on the reals is above equality modulo finite on P (ω). In this article we examine the effective content of these and related results by studying effectively Borel equivalence relations...

  7. Approximate equivalence in von Neumann algebras

    DING Huiru; Don Hadwin

    2005-01-01

    One formulation of D. Voiculescu's theorem on approximate unitary equivalence is that two unital representations π and ρ of a separable C*-algebra are approximately unitarily equivalent if and only if rank o π = rank o ρ. We study the analog when the ranges of π and ρ are contained in a von Neumann algebra R, the unitaries inducing the approximate equivalence must come from R, and "rank" is replaced with "R-rank" (defined as the Murray-von Neumann equivalence of the range projection).

  8. 21 CFR 26.9 - Equivalence determination.

    2010-04-01

    ... RECOGNITION OF PHARMACEUTICAL GOOD MANUFACTURING PRACTICE REPORTS, MEDICAL DEVICE QUALITY SYSTEM AUDIT REPORTS... Specific Sector Provisions for Pharmaceutical Good Manufacturing Practices § 26.9 Equivalence...

  9. 21 CFR 26.6 - Equivalence assessment.

    2010-04-01

    ... OF PHARMACEUTICAL GOOD MANUFACTURING PRACTICE REPORTS, MEDICAL DEVICE QUALITY SYSTEM AUDIT REPORTS... Specific Sector Provisions for Pharmaceutical Good Manufacturing Practices § 26.6 Equivalence...

  10. Unprecedented grain size effect on stacking fault width

    A. Hunter

    2013-09-01

    Full Text Available Using an atomistic-phase field dislocation dynamics model, we isolate and investigate grain size and stress effects on the stacking fault width created by partial dislocation emission from a boundary. We show that the nucleation stress for a Shockley partial is governed by size of the boundary defect and insensitive to grain size. We reveal a grain size regime in which the maximum value the stacking fault width attains increases with grain size.

  11. Width of the plasmon resonance in metal clusters

    Montag, B.; Reinhard, P.-G.

    1995-05-01

    The width of the plasmon resonance in the clusters Na+9, Na+21, and Na+41 is investigated in the framework of the structure-averaged jellium model and compared with recent experimental data. The two leading mechanisms for the line broadening are fragmentation of the resonance into nearby 1ph states and splitting through thermal quadrupole fluctuations. The fragmentation becomes activated mainly through octupole fluctuations and it gives the dominating contribution to the width.

  12. Correlations for reduced-width amplitudes in 49V

    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

  13. Crack width monitoring of concrete structures based on smart film

    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. (paper)

  14. Crack width monitoring of concrete structures based on smart film

    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.

  15. Pooling Morphometric Estimates: A Statistical Equivalence Approach.

    Pardoe, Heath R; Cutter, Gary R; Alter, Rachel; Hiess, Rebecca Kucharsky; Semmelroch, Mira; Parker, Donna; Farquharson, Shawna; Jackson, Graeme D; Kuzniecky, Ruben

    2016-01-01

    Changes in hardware or image-processing settings are a common issue for large multicenter studies. To pool MRI data acquired under these changed conditions, it is necessary to demonstrate that the changes do not affect MRI-based measurements. In these circumstances, classical inference testing is inappropriate because it is designed to detect differences, not prove similarity. We used a method known as statistical equivalence testing to address this limitation. Equivalence testing was carried out on 3 datasets: (1) cortical thickness and automated hippocampal volume estimates obtained from healthy individuals imaged using different multichannel head coils; (2) manual hippocampal volumetry obtained using two readers; and (3) corpus callosum area estimates obtained using an automated method with manual cleanup carried out by two readers. Equivalence testing was carried out using the "two one-sided tests" (TOST) approach. Power analyses of the TOST were used to estimate sample sizes required for well-powered equivalence testing analyses. Mean and standard deviation estimates from the automated hippocampal volume dataset were used to carry out an example power analysis. Cortical thickness values were found to be equivalent over 61% of the cortex when different head coils were used (q coils were statistically equivalent (TOST P = 4.28 × 10(-15) ). Manual hippocampal volume estimates obtained using two readers were not statistically equivalent (TOST P = .97). The use of different readers to carry out limited correction of automated corpus callosum segmentations yielded equivalent area estimates (TOST P = 1.28 × 10(-14) ). Power analysis of simulated and automated hippocampal volume data demonstrated that the equivalence margin affects the number of subjects required for well-powered equivalence tests. We have presented a statistical method for determining if morphometric measures obtained under variable conditions can be pooled. The equivalence testing technique is

  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

    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. 46 CFR 175.540 - Equivalents.

    2010-10-01

    ... corporate structure of a vessel's company when determining the acceptability of an equivalent system... lifesaving appliance or arrangement as an equivalent if it has performance characteristics at least... IMO Resolution A. 520(13) (incorporated by reference, see 46 CFR 175.600); or (2) Has...

  18. Arithmetic Operand Ordering for Equivalence Checking

    WENG Yanling; GE Haitong; YAN Xiaolang; Ren Kun

    2007-01-01

    An information extraction-based technique is proposed for RTL-to-gate equivalence checking. Distances are calculated on directed acyclic graph (AIG). Multiplier and multiplicand are distinguished on multiplications with different coding methods, with which the operand ordering/grouping information could be extracted from a given implementation gate netlist, helping the RTL synthesis engine generate a gate netlist with great similarity. This technique has been implemented in an internal equivalence checking tool, ZD_VIS. Compared with the simple equivalence checking, the speed is accelerated by at least 40% in its application to a class of arithmetic designs, addition and multiplication trees. The method can be easily incorporated into existing RTL-to-gate equivalence checking frameworks, increasing the robustness of equivalence checking for arithmetic circuits.

  19. Equivalence in Ventilation and Indoor Air Quality

    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.

  20. Statistical significance of spreading widths for doorway states

    The strength function constructed as the Lorentz-weighted average of the reduced widths of the Wigner-Eisenbud R matrix (or of a reactance K matrix) is a continuous and well-defined function of energy for a fragmented doorway state (isobaric analog resonance, fission isomer, etc.) in both weak and strong coupling. If the half-width I of the Lorentz weighting function is chosen appropriately, this strength function itself approximates a Lorentzian whose width is the spreading width GAMMA/sup arrow-down//sub I/ of Feshbach, Kerman, and Lemmer. An ensemble of 400 doorway systems characterized by coupling strengths ranging from strong to weak is used to study properties of GAMMA/sup arrow-down//sub I/ and to determine the accuracy with which it can be determined for a particular doorway by a least-squares fit to the strength function. The results of this numerical study show that (1) GAMMA/sup arrow-down//sub I/ is a characteristic of each doorway state system, and that (2) its value can be determined from experimentally measured resonance energies and widths with an uncertainty which is less than the fluctuations in its value from one system to another and which decreases as the coupling strength decreases

  1. Surface roughness from MOLA backscatter pulse-widths

    Poole, W. D.; Muller, J.-P.; Gupta, S.; Grindrod, P. M.

    2013-09-01

    The time-spread of backscatter laser altimeter pulses, known as pulse-widths, are thought to be capable of being used to infer variations in topography within the footprint of the laser pulse. Here, Mars Orbiter Laser Altimeter (MOLA) pulse-widths have been compared to surface roughness and slope, as measured from high-resolution digital terrain models (DTMs), over different terrains in order to understand how this dataset can be used in the selection of landing and roving sites, and in inferring surface formation and evolution. The results are varied, and suggest that pulsewidths do not respond consistently to variations in terrain. The results show that over Mars Science Laboratory (MSL) candidate landing sites, the pulse-widths can be used as a rough estimate of surface roughness at baselines much larger than the footprint of the pulse. Over much rougher terrain, these pulse-widths respond best to footprint scale slope, which suggests that an additional slope correction for 75 m baselines slopes is required to infer finer scale roughness. However, this is shown not to be the case, as correcting the pulse-widths for 75 m slopes at the MSL candidate sites, and detrending the DTM data, produced poorer results.

  2. Symphysis pubis width and unaffected hip joint width in patients with slipped upper femoral epiphysis: widening compared with normal values

    Tins, Bernhard; Cassar-Pullicino, Victor; Haddaway, Mike [RJAH Orthopaedic Hospital, Department of Radiology, Shropshire (United Kingdom)

    2010-04-15

    The exact pathomechanism of slipped upper femoral epiphysis (SUFE) remains elusive. This paper suggests a generalised abnormality of the development or maturation of cartilage as a possible cause. It is proposed that SUFE is part of a generalised abnormality of the cartilage formation or maturation resulting in abnormal measurements of cartilaginous joint structures. Radiographs of SUFE patients were assessed for the width of the unaffected hip joint and the symphysis pubis. Comparison with previously published normal values was made. Fifty-one patients were assessed, 35 male, 16 female. The average age was 12 years and 11 months combined for both sexes, 13 years 8 months for boys, 11 years 4 months for girls. Width of the symphysis pubis was assessed on 46 datasets, and comparison with normal values was performed using the Wilcoxon paired rank test. Statistical significance was set as p < 0.05. The average expected width was 5.8 mm (5.4-6.2 mm), the average measured width was 7.3 mm (3.5-12 mm), median value 7.0 mm, and the difference is statistically significant. Cartilage thickness of the uninvolved hip joint could be assessed in 46 cases, and comparison using the Wilcoxon paired rank test resulted in a statistically significant difference (significance set as p < 0.05). The average expected width was 4.9 mm (3.6-6.5 mm), the average measured width was 5.5 mm (4-8 mm), and median 5.3 mm. The results indicate that SUFE patients display a generalised increased width of joint cartilage for their age. This could be due to increased cartilage formation or decreased maturation or a combination of the two, and could explain the increased mechanical vulnerability of these children to normal or abnormal stresses, despite histologically normal organisation of the physis as shown in previous studies. (orig.)

  3. 78 FR 67360 - Ambient Air Monitoring Reference and Equivalent Methods: Designation of Five New Equivalent Methods

    2013-11-12

    ... 31, 2011 (76 FR 54326-54341). Two of the new equivalent methods for PM are automated monitoring... AGENCY Ambient Air Monitoring Reference and Equivalent Methods: Designation of Five New Equivalent Methods AGENCY: Office of Research and Development; Environmental Protection Agency (EPA). ACTION:...

  4. 77 FR 32632 - Ambient Air Monitoring Reference and Equivalent Methods: Designation of Three New Equivalent Methods

    2012-06-01

    ... of 40 CFR Part 53, as amended on August 31, 2011 (76 FR 54326- 54341). The new equivalent method for... AGENCY Ambient Air Monitoring Reference and Equivalent Methods: Designation of Three New Equivalent Methods AGENCY: Environmental Protection Agency. ACTION: Notice. SUMMARY: Notice is hereby given that...

  5. 77 FR 60985 - Ambient Air Monitoring Reference and Equivalent Methods: Designation of Three New Equivalent Methods

    2012-10-05

    ... 53, as amended on August 31, 2011 (76 FR 54326-54341). The new equivalent methods are automated... AGENCY Ambient Air Monitoring Reference and Equivalent Methods: Designation of Three New Equivalent Methods AGENCY: Environmental Protection Agency. ACTION: Notice of the designation of three new...

  6. On Equivalence and Non-equivalence of Words and Phrases In Different Cultures

    高新霞

    2008-01-01

    This paper is mainly focused on the study of the relationship among three concepts, namely, culture,psychological association and equivalence or non-equivalence of words and phrases with combination of Problems posed by my students and discuss three patterns of the relationship with an attempt to describe the importance of culture to equivalence.

  7. Equivalence-Equivalence Responding: Training Conditions Involved in Obtaining a Stable Baseline Performance

    Garcia, Andres; Bohorquez, Cristobal; Perez, Vicente; Gutierrez, Maria Teresa; Gomez, Jesus; Luciano, Carmen; Wilson, Kelly

    2008-01-01

    Recent research has focused on the variables associated with equivalence-equivalence responding, in which participants match pairs of equivalent or nonequivalent stimuli. One such variable is the presence of response competition from nonarbitrary (physical) relational response options. In the current analysis, the experimenters examined the effect…

  8. Fast Width Detection in Corridor Using Hough Transform

    Mehrdad Javadi

    2012-11-01

    Full Text Available For many robotics and smart car applications it is vitally important to calculate the width. The present paper proposes a new approach for finding the width of a corridor within a constructed image frame that would keep a robot on a safe track away from walls. The main advantage of this approach is less computation time and hence faster response for path recognition. In this new approach, the Hugh Transform technique is also used as the basis of the provided algorithm. Within the determination of corridor width, in order to avoid the accident in the future researches, some approaches such as identify open space, modeling and reconstruction of three-dimensional space, can also be used.

  9. Modelling the widths of fission observables in GEF

    Schmidt K.-H.

    2013-03-01

    Full Text Available The widths of the mass distributions of the different fission channels are traced back to the probability distributions of the corresponding quantum oscillators that are coupled to the heat bath, which is formed by the intrinsic degrees of freedom of the fissioning system under the influence of pairing correlations and shell effects. Following conclusion from stochastic calculations of Adeev and Pashkevich, an early freezing due to dynamical effects is assumed. It is shown that the mass width of the fission channels in low-energy fission is strongly influenced by the zero-point motion of the corresponding quantum oscillator. The observed variation of the mass widths of the asymmetric fission channels with excitation energy is attributed to the energy-dependent properties of the heat bath and not to the population of excited states of the corresponding quantum oscillator.

  10. Interatomic Coulombic decay widths of helium trimer: Ab initio calculations

    Kolorenč, Přemysl, E-mail: kolorenc@mbox.troja.mff.cuni.cz [Charles University in Prague, Faculty of Mathematics and Physics, Institute of Theoretical Physics, V Holešovičkách 2, 180 00 Prague (Czech Republic); Sisourat, Nicolas [Sorbonne Universités, UPMC Univ Paris 06, UMR 7614, Laboratoire de Chimie Physique Matière et Rayonnement, F-75005 Paris (France); CNRS, UMR 7614, Laboratoire de Chimie Physique Matière et Rayonnement, F-75005 Paris (France)

    2015-12-14

    We report on an extensive study of interatomic Coulombic decay (ICD) widths in helium trimer computed using a fully ab initio method based on the Fano theory of resonances. Algebraic diagrammatic construction for one-particle Green’s function is utilized for the solution of the many-electron problem. An advanced and universal approach to partitioning of the configuration space into discrete states and continuum subspaces is described and employed. Total decay widths are presented for all ICD-active states of the trimer characterized by one-site ionization and additional excitation of an electron into the second shell. Selected partial decay widths are analyzed in detail, showing how three-body effects can qualitatively change the character of certain relaxation transitions. Previously unreported type of three-electron decay processes is identified in one class of the metastable states.

  11. Conditions on Ramsey non-equivalence

    Axenovich, Maria; Rollin, Jonathan; Ueckerdt, Torsten

    2015-01-01

    Given a graph H, a graph G is called a Ramsey graph of H if there is a monochromatic copy of H in every coloring of the edges of G with two colors. Two graphs G, H are called Ramsey equivalent if they have the same set of Ramsey graphs. Fox et al. [J. Combin. Theory Ser. B 109 (2014), 120--133] asked whether there are two non-isomorphic connected graphs that are Ramsey equivalent. They proved that a clique is not Ramsey equivalent to any other connected graph. Results of Nesetril et al. showe...

  12. Equivalences of twisted K3 surfaces

    Huybrechts, Daniel; Stellari, Paolo

    2004-01-01

    We prove that two derived equivalent twisted K3 surfaces have isomorphic periods. The converse is shown for K3 surfaces with large Picard number. It is also shown that all possible twisted derived equivalences between arbitrary twisted K3 surfaces form a subgroup of the group of all orthogonal transformations of the cohomology of a K3 surface. The passage from twisted derived equivalences to an action on the cohomology is made possible by twisted Chern characters that will be introduced for a...

  13. Shift adn width of HeII lines

    Based on a quantum statistical many-particle theory, the shift and the width of some He II lines have been evaluated. Ion dynamics have been treated within the model microfield method. Furthermore, fine structure splitting has been taken into account in order to check whether this effect is the cause for the existing large discrepancies between theoretical and experimental line widths. Besides the electronic contributions to the line shift, the shift due to the inhomogeneities of the ionic microfield as well as that due to the quadratic Stark effect has been included. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  14. Planar waveguide with "twisted" boundary conditions: small width

    Borisov, D

    2011-01-01

    We consider a planar waveguide with "twisted" boundary conditions. By twisting we mean a special combination of Dirichlet and Neumann boundary conditions. Assuming that the width of the waveguide goes to zero, we identify the effective (limiting) operator as the width of the waveguide tends to zero, establish the uniform resolvent convergence in various possible operator norm, and give the estimates for the rates of convergence. We show that studying the resolvent convergence can be treated as a certain threshold effect and we present an elegant technique which justifies such point of view.

  15. On the Path-Width of Integer Linear Programming

    Constantin ENEA; Habermehl, Peter; Inverso, Omar; Parlato, Gennaro

    2016-01-01

    We consider the feasibility problem of integer linear programming (ILP). We show that solutions of any ILP instance can be naturally represented by an FO-definable class of graphs. For each solution, there may be many graphs representing it. However, one of these graphs is of path-width at most 2n, where n is the number of variables in the instance. Since FO is decidable on graphs of bounded path-width, we obtain an alternative decidability result for ILP. The technique we use underlines a co...

  16. Widths of the isobaric analog state of 208Pb

    Both escape and spreading widths are evaluated microscopically in a consistent framework for the isobaric analog of the 206Pb ground state. A TDA Green function is obtained within the space of discretized J=0+ proton-particle neutron-hole configurations using the Skyrme interaction. Couplings of these configurations with continuum and more complicated configurations are included into TDA matrix elements with a form of energy dependent terms. The energy and the widths of the isobaric analog resonance are obtained as a result of the matrix diagonalization. Comparison is made of the results with the former theoretical calculations as well as experimental data. (orig.)

  17. Energy and decay width of the pi-K atom

    Jallouli, H.; Sazdjian, H.

    2006-01-01

    The energy and 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 ...

  18. Energy and decay width of the pi-K atom

    Jallouli, H

    2006-01-01

    The energy and 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.

  19. Domain wall width of lithium niobate poled during growth

    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.

  20. Statistical analysis of s-wave neutron reduced widths

    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 ν = 1) for most of the cases. However there are apparent deviations from ν = 1 and possible explanation and significance of this deviation is given. These considerations are likely to modify the evaluation of neutron cross section. (author)

  1. Fjords in viscous fingering: selection of width and opening scale

    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.

  2. Equivalent circuit with complex physical constants and equivalent-parameters-expressed dissipation factors of piezoelectric materials

    Chen Yu; Wen Yu-Mei; Li Ping

    2006-01-01

    The equivalent circuit with complex physical constants for a piezoelectric ceramic in thickness mode is established.In the equivalent circuit, electric components (equivalent circuit parameters) are connected to real and imaginary parts of complex physical coefficients of piezoelectric materials. Based on definitions of dissipation factors, three of them (dielectric, elastic and piezoelectric dissipation factors) are represented by equivalent circuit parameters. Since the equivalent circuit parameters are detectable, the dissipation factors can be easily obtained. In the experiments, the temperature and the stress responses of the three dissipation factors are measured.

  3. Be Stars in the Open Cluster NGC 6830

    Yu, Po-Chieh; Lin, Hsing-Wen; Lee, Chien-De; Konidaris, Nick; Ngeow, Chow-Choong; Ip, Wing-Huen; Chen, Wen-Ping; Chen, Hui-Chen; Malkan, Matthew A; Chang, Chan-Kao; Laher, Russ; Huang, Li-Ching; Cheng, Yu-Chi; Edelson, Rick; Ritter, Andreas; Quimby, Robert; Ben-Ami, Sagi; Ofek, Eran O; Surace, Jason; Kulkarni, Shrinivas R

    2016-01-01

    We report the discovery of 2 new Be stars, and re-identify one known Be star in the open cluster NGC 6830. Eleven H-alpha emitters were discovered using the H-alpha imaging photometry of the Palomar Transient Factory Survey. Stellar membership of the candidates was verified with photometric and kinematic information using 2MASS data and proper motions. The spectroscopic confirmation was carried out by using the Shane 3-m telescope at Lick observatory. Based on their spectral types, three H-alpha emitters were confirmed as Be stars with H-alpha equivalent widths > -10 Angstrom. Two objects were also observed by the new spectrograph SED-Machine on the Palomar 60 inch Telescope. The SED-Machine results show strong H-alpha emission lines, which are consistent with the results of the Lick observations. The high efficiency of the SED-Machine can provide rapid observations for Be stars in a comprehensive survey in the future.

  4. Nuclear Regulatory Commission equivalency evaluation report

    This paper provides the basis for concluding that using the seismic design criteria, defined in DOE order 4580.28, Natural Phenomena Hazards Mitigation, and its implementing standards provides safety equivalent to NRC criteria

  5. Nuclear Regulatory Commission equivalency evaluation report

    Garvin, L.J.

    1995-10-01

    This paper provides the basis for concluding that using the seismic design criteria, defined in DOE order 4580.28, Natural Phenomena Hazards Mitigation, and its implementing standards provides safety equivalent to NRC criteria.

  6. Equivalence Principle, Higgs Boson and Cosmology

    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.

  7. [Therapeutic equivalence of the new oral anticoagulants].

    Moreno Villar, A; Nacle López, I; Barbero Hernández, M J; Lizan Tudela, L

    2015-10-01

    In an attempt to minimize the economic impact due to the incorporation of innovative drugs, health authorities have promoted and supported the evaluation and market positioning of drugs, as equivalent therapeutic alternatives. This issue has recently gained importance, possibly due to the current economic crisis. The equivalent therapeutic alternatives are justified by the need to compete on price, and by the authorities recommendation to establish therapeutic equivalence, price and financing of medicinal products at the same time. The establishment of the new oral anticoagulants and the equivalent therapeutic alternatives is a problematic issue if it is based on the absence of direct comparisons between different drugs and the questionable methodology used in the current indirect comparisons. Currently, it is difficult to determine when a new oral anticoagulant is more recommendable than others, but efforts are being made in order to propose alternatives for the decision based on patient characteristics. PMID:26146035

  8. Integral equivalence of multidimensional differential systems

    Gorbuzov, V. N.

    2009-01-01

    The bases of the theory of integrals for multidimensional differential systems are stated. The integral equivalence of total differential systems, linear homogeneous systems of partial differential equations, and Pfaff systems of equations is established.

  9. Lexical Equivalence in Business English Translation

    王淼

    2009-01-01

    Business English is English used in business contexts.It is a combination of knowledge in both business and language.Being faithful is ofprimary importance in business English Iranslation,but a translation only faithful to the original is far from adequate if it is not appropriate to the original in style.Therefore,in doing business translation,the translators should always keep in mind the specific purposes and functions ofthe original texts and make attempts to render the closet natural equivalent in the target language.This atticle focuses on equivalence at lexical level in this chapter.Several major tendencies toward word choice arc put forward and stylistic equivalence in each case is analyzed at some length.Three criteria are proposed here for choosing suitable words:preciseness,concise-ness and gracefulness.1fthe three criteria are satisfied,stylistic equivalence will also be established.

  10. Lexical Equivalence in Business English Translation

    王淼

    2009-01-01

    Business English is English used in business contexts.It is a combination of knowledge in both business and language.Being faithful is of primary importance in business English translation,but a translation only faithful to the original is far from adequate if it is not appropriate to the original in style.Therefore,in doing business translation,the translators should always keep in mind the specific purposes and functions of the original texts and make attempts to render the closet natural equivalent in the target language.This article focuses on equivalence at lexical level in this chapter.Several major tendencies toward word choice are put forward and stylistic equivalence in each case is analyzed at some length.Three criteria are proposed here for choosing suitable words:preciseness,conciseness and gracefulness.If the three criteria are satisfied,stylistic equivalence will also be established.

  11. Agency Full Time Equivalency Reporting System

    US Agency for International Development — AFTERS provides an automated means for the Agency to report its full time equivalency work years to the Office of Management and Budget (OMB) and Office of...

  12. Quantum equivalence principle without mass superselection

    Hernandez-Coronado, H., E-mail: hcoronado@nucleares.unam.mx [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Av. Universidad, Del. Coyoacán, México (Mexico); Okon, E., E-mail: eokon@filosoficas.unam.mx [Instituto de Investigaciones Filosóficas, Universidad Nacional Autónoma de México, Av. Universidad, Del. Coyoacán, México (Mexico)

    2013-11-08

    The standard argument for the validity of Einstein's equivalence principle in a non-relativistic quantum context involves the application of a mass superselection rule. The objective of this work is to show that, contrary to widespread opinion, the compatibility between the equivalence principle and quantum mechanics does not depend on the introduction of such a restriction. For this purpose, we develop a formalism based on the extended Galileo group, which allows for a consistent handling of superpositions of different masses, and show that, within such scheme, mass superpositions behave as they should in order to obey the equivalence principle. - Highlights: • We propose a formalism for consistently handling, within a non-relativistic quantum context, superpositions of states with different masses. • The formalism utilizes the extended Galileo group, in which mass is a generator. • The proposed formalism allows for the equivalence principle to be satisfied without the need of imposing a mass superselection rule.

  13. ON THE EQUIVALENCE OF THE ABEL EQUATION

    2006-01-01

    This article uses the reflecting function of Mironenko to study some complicated differential equations which are equivalent to the Abel equation. The results are applied to discuss the behavior of solutions of these complicated differential equations.

  14. Distinguishing Provenance Equivalence of Earth Science Data

    Tilmes, Curt; Yesha, Ye; Halem, M.

    2010-01-01

    Reproducibility of scientific research relies on accurate and precise citation of data and the provenance of that data. Earth science data are often the result of applying complex data transformation and analysis workflows to vast quantities of data. Provenance information of data processing is used for a variety of purposes, including understanding the process and auditing as well as reproducibility. Certain provenance information is essential for producing scientifically equivalent data. Capturing and representing that provenance information and assigning identifiers suitable for precisely distinguishing data granules and datasets is needed for accurate comparisons. This paper discusses scientific equivalence and essential provenance for scientific reproducibility. We use the example of an operational earth science data processing system to illustrate the application of the technique of cascading digital signatures or hash chains to precisely identify sets of granules and as provenance equivalence identifiers to distinguish data made in an an equivalent manner.

  15. The Nonequivalence of High School Equivalents

    Stephen V. Cameron; Heckman, James J.

    1991-01-01

    This paper analyzes the causes and consequences of the growing proportion of high-school-certified persons who achieve that status by exam certification rather than through high school graduation. Exam-certified high school equivalents are statistically indistinguishable from high school dropouts. Both dropouts and exam-certified equivalents have comparably poor wages, earnings, hours of work, unemployment experiences and job tenure. This is so whether or not ability measures are used to cont...

  16. On the generation of equivalent hamiltonians

    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)

  17. Fucoidan Promotes the Reconstruction of Skin Equivalents

    Song, Yu Seok; Li, Hailan; Balcos, Marie Carmel; Yun, Hye-Young; Baek, Kwang Jin; Kwon, Nyoun Soo; Choi, Hye-Ryung; Park, Kyoung-Chan; Kim, Dong-Seok

    2014-01-01

    In this study we investigated the effects of fucoidan on the proliferation of fibroblasts and the reconstruction of a skin equivalent (SE). Fucoidan significantly stimulated the proliferation of CCD-25Sk human fibroblasts and Western blot analysis demonstrated that fucoidan markedly increased the expression of cyclin D1 and decreased the expression of p27. Fucoidan was used to reconstruct SE. Immunohistochemical staining showed that the addition of fucoidan to dermal equivalents increased exp...

  18. Dark matter and the equivalence principle

    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.

  19. On Equivalence Results in Business Cycle Accounting

    NUTAHARA Kengo; Inaba, Masaru

    2008-01-01

    Business cycle accounting rests on the insight that the prototype neoclassical growth model with time-varying wedges can achieve the same allocation generated by a large class of frictional models: equivalence results. Equivalence results are shown under general conditions about the process of wedges while it is often specified to be the first order vector autoregressive when one applies business cycle accounting to actual data. In this paper, we characterize the class of models covered by th...

  20. Notions of Equivalence in Software Design

    King, David; Kimble, Chris

    2004-01-01

    Design methods in information systems frequently create software descriptions using formal languages. Nonetheless, most software designers prefer to describe software using natural languages. This distinction is not simply a matter of convenience. Natural languages are not the same as formal languages; in particular, natural languages do not follow the notions of equivalence used by formal languages. In this paper, we show both the existence and coexistence of different notions of equivalence...

  1. The equivalence principle and spatial curvature

    An examination is made of the connection between the equivalence principle of general relativity and the non-Euclidean properties of space. The arguments commonly advanced to suggest a necessary connection between these two features of general relativity are reviewed and critically discussed. It is shown that although gravitational time dilation is an immediate consequence of the equivalence principle the corresponding effects on space are not such immediate or logically necessary consequences of this principle. (author)

  2. Explicit Homotopy Equivalences Between Some Operads

    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.

  3. Equivalence relations and the reinforcement contingency.

    Sidman, M

    2000-01-01

    Where do equivalence relations come from? One possible answer is that they arise directly from the reinforcement contingency. That is to say, a reinforcement contingency produces two types of outcome: (a) 2-, 3-, 4-, 5-, or n-term units of analysis that are known, respectively, as operant reinforcement, simple discrimination, conditional discrimination, second-order conditional discrimination, and so on; and (b) equivalence relations that consist of ordered pairs of all positive elements that...

  4. A Measurement of the Total Width, the Electronic Width, and the Mass of the Upsilon(10580) Resonance

    Aubert, B; Boutigny, D; Couderc, F; Gaillard, J M; Hicheur, A; Karyotakis, Yu; Lees, J P; Tisserand, V; Zghiche, A; Palano, A; Pompili, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Borgland, A W; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Le Clerc, C; Lynch, G; Merchant, A M; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, Michael T; Shelkov, V G; Telnov, A V; Wenzel, W A; Ford, K; Harrison, T J; Hawkes, C M; Morgan, S E; Watson, A T; Fritsch, M; Goetzen, K; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Steinke, M; Boyd, J T; Chevalier, N; Cottingham, W N; Kelly, M P; Latham, T E; Wilson, F F; Çuhadar-Dönszelmann, T; Hearty, C; Mattison, T S; McKenna, J A; Thiessen, D; Kyberd, P; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Ivanchenko, V N; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Yushkov, A N; Best, D; Bruinsma, M; Chao, M; Eschrich, I; Kirkby, D; Lankford, A J; Mandelkern, M A; Mommsen, R K; Röthel, W; Stoker, D P; Buchanan, C; Hartfiel, B L; Gary, J W; Shen, B C; Wang, K; Del Re, D; Hadavand, H K; Hill, E J; MacFarlane, D B; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Dahmes, B; Levy, S L; Long, O; Lu, A; Mazur, M A; Richman, J D; Verkerke, W; Beck, T W; Eisner, A M; Heusch, C A; Lockman, W S; Schalk, T; Schmitz, R E; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dubois-Felsmann, G P; Dvoretskii, A; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Yang, S; Jayatilleke, S M; Mancinelli, G; Meadows, B T; Sokoloff, M D; Abe, T; Blanc, F; Bloom, P; Chen, S; Clark, P J; Ford, W T; Nauenberg, U; Olivas, A; Rankin, P; Smith, J G; Zhang, L; Chen, A; Harton, J L; Soffer, A; Toki, W H; Wilson, R J; Zeng, Q L; Altenburg, D; Brandt, T; Brose, J; Colberg, T; Dickopp, M; Feltresi, E; Hauke, A; Lacker, H M; Maly, E; Müller-Pfefferkorn, R; Nogowski, R; Otto, S; Petzold, A; Schubert, J; Schubert, Klaus R; Schwierz, R; Spaan, B; Sundermann, J E; Bernard, D; Bonneaud, G R; Brochard, F; Grenier, P; Schrenk, S; Thiebaux, C; Vasileiadis, G; Verderi, M; Bard, D J; Khan, A; Lavin, D; Muheim, F; Playfer, S; Andreotti, M; Azzolini, V; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Piemontese, L; Sarti, A; Treadwell, E; Baldini-Ferroli, R; Calcaterra, A; De Sangro, R; Finocchiaro, G; Patteri, P; Piccolo, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Crosetti, G; Lo Vetere, M; Macri, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Bailey, S; Brandenburg, G; Morii, M; Won, E; Dubitzky, R S; Langenegger, U; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Gaillard, J R; Morton, G W; Nash, J A; Taylor, G P; Grenier, G J; Mallik, U; Cochran, J; Crawley, H B; Lamsa, J; Meyer, W T; Prell, S; Rosenberg, E I; Yi, J; Davier, M; Grosdidier, G; Höcker, A; Laplace, S; Le Diberder, F R; Lepeltier, V; Lutz, A M; Petersen, T C; Plaszczynski, S; Schune, M H; Tantot, L; Wormser, G; Cheng, C H; Lange, D J; Simani, M C; Wright, D M; Bevan, A J; Coleman, J P; Fry, J R; Gabathuler, Erwin; Gamet, R; Parry, R J; Payne, D J; Sloane, R J; Touramanis, C; Back, J J; Cormack, C M; Harrison, P F; Mohanty, G B; Brown, C L; Cowan, G; Flack, R L; Flächer, H U; Green, M G; Marker, C E; McMahon, T R; Ricciardi, S; Salvatore, F; Vaitsas, G; Winter, M A; Brown, D; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Hart, P A; Hodgkinson, M C; Lafferty, G D; Lyon, A J; Williams, J C; Farbin, A; Hulsbergen, W D; Jawahery, A; Kovalskyi, D; Lae, C K; Lillard, V; Roberts, D A; Blaylock, G; Dallapiccola, C; Flood, K T; Hertzbach, S S; Kofler, R; Koptchev, V B; Moore, T B; Saremi, S; Stängle, H; Willocq, S; Cowan, R; Sciolla, G; Taylor, F; Yamamoto, R K; Mangeol, D J J; Patel, P M; Robertson, S H; Lazzaro, A; Palombo, F; Bauer, J M; Cremaldi, L M; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Taras, P; Nicholson, H; Cavallo, N; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M; Bulten, H; Raven, G; Wilden, L; Jessop, C P; LoSecco, J M; Gabriel, T A; Allmendinger, T; Brau, B; Gan, K K; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Pulliam, T; Rahimi, A M; Ter-Antonian, R; Wong, Q K; Brau, J E; Frey, R; Igonkina, O; Potter, C T; Sinev, N B; Strom, D; Torrence, E; Colecchia, F; Dorigo, A; Galeazzi, F; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Tiozzo, G; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; La Vaissière, C de; Del Buono, L; Hamon, O; John, M J J; Leruste, P; Ocariz, J; Pivk, M; Roos, L; T'Jampens, S; Therin, G; Manfredi, P F; Re, V; Behera, P K; Gladney, L; Guo, Q H; Panetta, J; Anulli, F; Biasini, M; Peruzzi, I M; Pioppi, M; Angelini, C; Batignani, G; Bettarini, S; Bondioli, M; Bucci, F; Calderini, G; Carpinelli, M; Del Gamba, V; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Martínez-Vidal, F; Morganti, M; Neri, N; Paoloni, E; Rama, M; Rizzo, G; Sandrelli, F; Walsh, J; Haire, M; Judd, D; Paick, K; Wagoner, D E; Danielson, N; Elmer, P; Lü, C; Miftakov, V; Olsen, J; Smith, A J S; Bellini, F; Cavoto, G; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Pierini, M; Piredda, G; Safai-Tehrani, F; Voena, C; Christ, S; Wagner, G; Waldi, R; Adye, T; De Groot, N; Franek, B J; Geddes, N I; Gopal, G P; Olaiya, E O; Aleksan, Roy; Emery, S; Gaidot, A; Ganzhur, S F; Giraud, P F; Hamel de Monchenault, G; Kozanecki, Witold; Langer, M; Legendre, M; London, G W; Mayer, B; Schott, G; Vasseur, G; Yéche, C; Zito, M; Purohit, M V; Weidemann, A W; Yumiceva, F X; Aston, D; Bartoldus, R; Berger, N; Boyarski, A M; Buchmüller, O L; Convery, M R; Cristinziani, M; De Nardo, Gallieno; Donald, M; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W M; Elsen, E E; Fan, S; Field, R C; Fisher, A; Glanzman, T; Gowdy, S J; Hadig, T; Halyo, V; Hast, C; Hrynóva, T; Innes, W R; Kelsey, M H; Kim, P; Kocian, M L; Leith, D W G S; Libby, J; Luitz, S; Lüth, V; Lynch, H L; Marsiske, H; Messner, R; Müller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Petrak, S; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Seeman, J; Simi, G; Snyder, A; Soha, A; Stelzer, J; Su, D; Sullivan, M K; Vavra, J; Wagner, S R; Weaver, M; Weinstein, A J R; Wienands, U; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Young, C C; Burchat, Patricia R; Edwards, A J; Meyer, T I; Petersen, B A; Roat, C; Ahmed, S; Alam, M S; Ernst, J A; Saeed, M A; Saleem, M; Wappler, F R; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Kim, H; Ritchie, J L; Satpathy, A; Schwitters, R F; Izen, J M; Kitayama, I; Lou, X C; Ye, S; Bianchi, F; Bóna, M; Gallo, F; Gamba, D; Borean, C; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Dittongo, S; Grancagnolo, S; Lanceri, L; Poropat, P; Vitale, L; Vuagnin, G; Panvini, R S; Banerjee, Sw; Brown, C M; Fortin, D; Jackson, P D; Kowalewski, R V; Roney, J M; Band, H R; Dasu, S; Datta, M; Eichenbaum, A M; Hollar, J J; Johnson, J R; Kutter, P E; Li, H; Liu, R; Di Lodovico, F; Mihályi, A; Mohapatra, A K; Pan, Y; Prepost, R; Sekula, S J; Tan, P; Von Wimmersperg-Töller, J H; Wu, J; Wu, S L; Yu, Z; Neal, H

    2004-01-01

    We present a measurement of the parameters of the $\\Upsilon(10580)$ resonance based on a dataset collected with the BABAR detector at the SLAC PEP-II asymmetric $B$ factory. We measure the total width $\\Gamma_{\\rm tot}$ to be $(20.7\\pm1.6\\pm2.5) {\\rm MeV}$, the electronic partial width $\\Gamma_{ee} = (0.321\\pm0.017\\pm0.029) {\\rm keV}$ and the mass $M = (10579.3\\pm0.4\\pm1.2) {\\rm MeV/c^2}$.

  5. Surface width of the Solid-On-Solid models

    Arisue, H

    1998-01-01

    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.

  6. Directed path-width and monotonicity in digraph searching

    Barat, Janos

    2006-01-01

    Directed path-width was defined by Reed, Thomas and Seymour around 1995. The author and P. Hajnal defined a cops-and-robber game on digraphs in 2000. We prove that the two notions are closely related and for any digraph D, the corresponding graph parameters differ by at most one. The result is ac...

  7. Echo width of foam supports used in scattering measurements

    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...

  8. The width of gamma-ray burst spectra

    Axelsson, Magnus

    2014-01-01

    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 $EF_E$ 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/GBM and CGRO/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% of long GRBs and 85% of short GRBs are incompatible wi...

  9. Width-parameterized SAT: Time-Space Tradeoffs

    Chen, Shiteng; Papakonstantinou, Periklis; Tang, Bangsheng

    2011-01-01

    Width parameterizations of SAT, such as tree-width and path-width, enable the study of computationally more tractable and practical SAT instances. We give two simple algorithms. One that runs simultaneously in time-space $(O^*(2^{2tw(\\phi)}), O^*(2^{tw(\\phi)}))$ and another that runs in time-space $(O^*(3^{tw(\\phi)\\log{|\\phi|}}),|\\phi|^{O(1)})$, where $tw(\\phi)$ is the tree-width of a formula $\\phi$ with $|\\phi|$ many clauses and variables. This partially answers the question of Alekhnovitch and Razborov, who also gave algorithms exponential both in time and space, and asked whether the space can be made smaller. We conjecture that every algorithm for this problem that runs in time $2^{tw(\\phi)\\mathbf{o(\\log{|\\phi|})}}$ necessarily blows up the space to exponential in $tw(\\phi)$. We introduce a novel way to combine the two simple algorithms that allows us to trade \\emph{constant} factors in the exponents between running time and space. Our technique gives rise to a family of algorithms controlled by two param...

  10. Spreading width of Gamow-Teller resonances in 208Bi

    The spreading width of the Gamow-Teller resonance in 208Bi is studied in the self-consistent TDA with the Skyrme interaction. Coupling between 1p1h states and 2p2h states are included in the TDA linear response function. (orig.)

  11. Visualizing the Mass and Width Spectrum of Unstable Particles

    Harshman, N. L.

    2003-01-01

    Several graphical representations of the mass and width spectrum of unstable subatomic particles are presented. Such plots are useful tools for introducing students to the particle zoo and provide students an alternate way to organize conceptually what can seem like an overwhelming amount of data. In particular, such graphs highlight phenomenological features of unstable particles characteristic of different energy and time scales.

  12. Estimation of the Beam Width in Magnetic Mass Spectrometer

    O.N. Peregudov

    2010-01-01

    Full Text Available A method for estimation of the beam width in magnetic sector mass spectrometers is proposed. This method consists in the restoration of the initial ion density distribution function in a beam cross-section before the receiving collector slit and can be used for the qualitative estimation of the mass spectrometer ion-optical scheme.

  13. Lithologic controls on valley width and strath terrace formation

    Schanz, Sarah A.; Montgomery, David R.

    2016-04-01

    Valley width and the degree of bedrock river terrace development vary with lithology in the Willapa and Nehalem river basins, Pacific Northwest, USA. Here, we present field-based evidence for the mechanisms by which lithology controls floodplain width and bedrock terrace formation in erosion-resistant and easily friable lithologies. We mapped valley surfaces in both basins, dated straths using radiocarbon, compared valley width versus drainage area for basalt and sedimentary bedrock valleys, and constructed slope-area plots. In the friable sedimentary bedrock, valleys are 2 to 3 times wider, host flights of strath terraces, and have concavity values near 1; whereas the erosion-resistant basalt bedrock forms narrow valleys with poorly developed, localized, or no bedrock terraces and a channel steepness index half that of the friable bedrock and an average channel concavity of about 0.5. The oldest dated strath terrace on the Willapa River, T2, was active for nearly 10,000 years, from 11,265 to 2862 calibrated years before present (cal YBP), whereas the youngest terrace, T1, is Anthropocene in age and recently abandoned. Incision rates derived from terrace ages average 0.32 mm y- 1 for T2 and 11.47 mm y- 1 for T1. Our results indicate bedrock weathering properties influence valley width through the creation of a dense fracture network in the friable bedrock that results in high rates of lateral erosion of exposed bedrock banks. Conversely, the erosion-resistant bedrock has concavity values more typical of detachment-limited streams, exhibits a sparse fracture network, and displays evidence for infrequent episodic block erosion and plucking. Lithology thereby plays a direct role on the rates of lateral erosion, influencing valley width and the potential for strath terrace planation and preservation.

  14. Intrinsic propagation of magnetic island with finite width

    Full text: The modified Rutherford equation is used as a model equation which is describing temporal evolution of the neoclassical tearing mode (NTM). The often-used polarization term plays a stabilizing role on the NTM when the magnetic island rotates in the direction of the ion diamagnetic drift, therefore it is important to determine the direction of island propagation to estimate the threshold of island width for the NTM onset. The NTM is essentially the nonlinear instability, hence it is useful to perform numerical calculations for determining the propagation direction of island with finite width where nonlinearity becomes to be important. In this work, the dependence of island width on the direction of island propagation is investigated in two dimensional slab geometry by using a two-fluid model including both diamagnetic drifts of ions and electrons. When equilibrium current profile is unstable for the tearing mode, it is found that the magnetic island rotates toward the direction of the electron diamagnetic drift in so far as the island width is small comparable to the ion Larmor radius ρi. The threshold where the propagation direction turns into the direction of ion diamagnetic drift is found to large comparable to the island saturation width. We also found that the threshold becomes lower as the temperature ratio between ion and electron fluid becomes large or the poloidal beta becomes lower. The island is found to rotate toward the direction of the ion diamagnetic drift as the viscosity becomes small. The physical mechanism of determining the propagation direction is discussed in the presentation. (author)

  15. Markov Equivalences for Subclasses of Loopless Mixed Graphs

    Sadeghi, Kayvan

    2011-01-01

    In this paper we discuss four problems regarding Markov equivalences for subclasses of loopless mixed graphs. We classify these four problems as finding conditions for internal Markov equivalence, which is Markov equivalence within a subclass, for external Markov equivalence, which is Markov equivalence between subclasses, for representational Markov equivalence, which is the possibility of a graph from a subclass being Markov equivalent to a graph from another subclass, and finding algorithm...

  16. a Linear Model for Meandering Rivers with Arbitrarily Varying Width

    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

  17. Pressure equivalents in industrial gas pipelines

    Metel' kov, V.P.

    1980-01-01

    Pressure equivalence is a mathematical concept used to explain action and load parameters for pipelines. These two parameters are congruent to pressures encountered in pipelines. The research examined pressure equivalence in 820 by 8 millimeter pipelines in the Samotlor region and took into account the influence of support jams during first and second category jamming. It was determined that the absolute dimensions to pressure pulsations were significantly larger than plus or minus ten percent from (Prab) and even exceeded (Prab) in certain instances. The ratios at which (Prab) can be exceeded vary with relation to the jam supports and the maximum variations stem from yield in the metal pipelines themselves. The above concepts can be used to study the effects of pressure equivalence upon loads and pressures of Samotlor field pipelines and to select appropriate pipeline planning and construction methods. The conclusions drawn are valid for industrial surface pipelines used at below limit pressures. Annular and daily temperature variations in the outside air are considered with regard to their effect upon the pressure equivalence within the lower sections of the pipeline. Deviations here have been noted to exceed (formula). It was observed that in the case of underground pipelines, operated at below limit pressures, pressure equivalence occured in the upper section of the pipeline.

  18. Equivalent magnetization over the World Ocean

    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

  19. Quantum mechanics and the equivalence principle

    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

  20. Water equivalence of polymer gel dosimeters

    To evaluate the water equivalence and radiation transport properties of polymer gel dosimeters over the wide range of photon and electron energies 14 different types of polymer gels were considered. Their water equivalence was evaluated in terms of effective atomic number (Zeff), electron density (ρe), photon mass attenuation coefficient (μ/ρ), photon mass energy absorption coefficient (μen/ρ) and total stopping power (S/ρ)tot of electrons using the XCOM and the ESTAR database. The study showed that the effective atomic number of polymer gels were very close (en/ρ for all polymer gels were in close agreement (tot of electrons in polymer gel dosimeters were within 1% agreement with that of water. From the study we conclude that at lower energy (<80keV) the polymer gel dosimeters cannot be considered water equivalent and study has to be carried out before using the polymer gel for clinical application

  1. On the Equivalence of Quadratic APN Functions

    Byrne, Eimear; McGuire, Gary; Nebe, Gabriele

    2011-01-01

    Establishing the CCZ-equivalence of a pair of APN functions is generally quite difficult. In some cases, when seeking to show that a putative new infinite family of APN functions is CCZ inequivalent to an already known family, we rely on computer calculation for small values of n. In this paper we present a method to prove the inequivalence of quadratic APN functions with the Gold functions. Our main result is that a quadratic function is CCZ-equivalent to an APN Gold function if and only if it is EA-equivalent to that Gold function. As an application of this result, we prove that a trinomial family of APN functions that exist on finite fields of order 2^n where n = 2 mod 4 are CCZ inequivalent to the Gold functions. The proof relies on some knowledge of the automorphism group of a code associated with such a function.

  2. Determination of the width of the top quark

    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; Vertogradov, L S; Verzocchi, M; Vesterinen, M; Vilanova, D; Vint, P; Vokac, P; Wahl, H D; Wang, M H L S; Warchol, J; Watts, G; Wayne, M; Weberg, M; Welty-Rieger, L; Wetstein, M; White, A; Williams, D Wicke M R J; Wilson, G W; Wimpenny, S J; Wobisch, M; Wood, D R; Wyatt, T R; Xie, Y; Xu, C; Yacoob, S; Yamada, R; Yang, W -C; Yasuda, T; Yatsunenko, Y A; Ye, Z; Yin, H; Yip, K; Yoo, H D; Youn, S W; Yu, J; Zelitch, S; Zhao, T; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zivkovic, L

    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.

  3. Joint space width in dysplasia of the hip

    Jacobsen, Steffen; Sonne-Holm, Stig; Søballe, K;

    2005-01-01

    In a longitudinal case-control study, we followed 81 subjects with dysplasia of the hip and 136 control subjects without dysplasia for ten years assessing radiological evidence of degeneration of the hip at admission and follow-up. There were no cases of subluxation in the group with dysplasia....... Neither subjects with dysplasia nor controls had radiological signs of ongoing degenerative disease at admission. The primary radiological discriminator of degeneration of the hip was a change in the minimum joint space width over time. There were no significant differences between these with dysplasia...... and controls in regard to age, body mass index or occupational exposure to daily repeated lifting at admission.We found no significant differences in the reduction of the joint space width at follow-up between subjects with dysplasia and the control subjects nor in self-reported pain in the hip. The...

  4. Mass and width of a composite Higgs boson

    The scalar Higgs boson mass in a Technicolor model was obtained by Elias and Scadron with the analysis of an homogeneous Bethe-Salpeter equation (BSE), however it was performed before the most recent developments of walking gauge theories. It was not observed in their work that dynamically generated technifermion mass may vary according to the theory dynamics that forms the scalar bound state. This will be done in this work and we also call attention that their calculation must change to take into account the normalization condition of the BSE. We compute the width of the composite boson and show how the gauge group and fermion content of a technicolor theory can be inferred from the measurement of the mass and width of the scalar boson.

  5. The excision width in surgical treatment of basal cell carcinoma

    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. .

  6. Tunable plasmonic Bragg reflector with different graphene nanoribbon widths

    Zhuang, Huawei; Kong, Fanmin; Li, Kang; Sheng, Shiwei

    2015-09-01

    We propose and numerically analyze a Bragg reflector composed of periodically arranged graphene nanoribbon waveguides with different widths. Because of the unique property of the graphene edge mode, the effective index contrast used for the reflector can be obtained by designing graphene nanoribbons with different widths without changing the dielectric substrate structure. Good band stop filtering characteristics are shown at the band gap of the transmission spectrum by numerical simulation. The performance of the proposed Bragg reflector is analyzed in terms of different parameters, such as the chemical potential, the number of periods, and the size of the unit cell. The proposed Bragg reflector will be expected to have important potential applications in the highly integrated SPP-based photonic devices.

  7. The SOL width and the MHD interchange instability in tokamaks

    Kerner, W. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Pogutse, O. [Kurchatov institute, Moscow (Russian Federation)

    1994-07-01

    Instabilities in the SOL plasma can strongly influence the SOL plasma behaviour and in particular the SOL width. The SOL stability analysis shows that there exists a critical ratio of the thermal energy and the magnetic energy. If the SOL beta is greater than this critical value, the magnetic field cannot prevent the plasma displacement and a strong MHD instability in the SOL occurs. In the opposite case only slower resistive instabilities can develop. A theoretical investigation of the SOL plasma stability is presented for JET single-null and double-null divertor configurations. The dependence of the stability threshold on the SOL beta and on the sheath resistance is established. Applying a simple mixing length argument gives the scaling of the SOL width. 5 refs., 2 figs.

  8. A Direct Measurement of the $W$ Decay Width

    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.

  9. Determination of the width of the top quark

    Abazov, V.; B. Abbott; Abolins, M.; Acharya, B.; M. Adams; Adams, T.; Alexeev, G.; Alkhazov, G.; Altona, A.; Alverson, G.; Alves, G.(Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, Brazil); Ancu, L.; Aoki, M.; Arnoud, Y.; Arov, M.

    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...

  10. The complexity of the fermionant, and immanants of constant width

    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.

  11. Statistical analysis of P-wave neutron reduced widths

    The fluctuations of the p-wave neutron reduced widths for fifty one 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 p-wave neutron reduced widths of even-even nuclei fallow single channel Porter Thomas distribution (χ2-distribution with degree of freedom ν=1) for most of the cases where there are no intermediate structure. It is emphasized that the distribution in nuclei other than even-even may differ from a χ2-distribution with one degree of freedom. Possible explanation and significance of this deviation from ν=1 is given. (author)

  12. A Direct Measurement of the $W$ Decay Width

    Vine, Troy [Univ. of College, London (United Kingdom)

    2008-08-01

    A direct measurement of the W boson total decay width is presented in proton-antiproton collisions at √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-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.

  13. Width of Long Colour Flux Tubes in Lattice Gauge Systems

    Caselle, M.; F. Gliozzi; Magnea, U.; Vinti, S.

    1995-01-01

    In the confining phase of any gauge system the mean squared width of the colour flux tube joining a pair of quarks should grow logarithmically as a function of their distance, according to the effective string description of its infrared properties. New data on 3D Z_2 gauge theory, combined with high precision data on the interface physics of the 3D Ising model fit nicely this behaviour over a range of more than two orders of magnitude.

  14. Determination of the Υ(1s) leptonic width

    The data recorded with the MD-1 detector operated at the VEPP-4 storage ring were analyzed and the Υ(1s) resonance leptonic partial width and mass are determined. Γee=1.29+-0.03+-0.03 keV, M=9460.59+-0.09+-0.05 MeV/c2 are find. Thies new value of the Υ(1s) nass should superside the previously published value. 26 refs.; 6 figs.; 1 tab

  15. Pulse-Width-Modulating Driver for Brushless dc Motor

    Salomon, Phil M.

    1991-01-01

    High-current pulse-width-modulating driver for brushless dc motor features optical coupling of timing signals from low-current control circuitry to high-current motor-driving circuitry. Provides high electrical isolation of motor-power supply, helping to prevent fast, high-current motor-driving pulses from being coupled through power supplies into control circuitry, where they interfere with low-current control signals.

  16. W mass and width measurements at the Tevatron

    Nurse, Emily

    2007-01-01

    I present a measurement of the W boson mass (M_W) and width (G_W) using 200 and 350 pb-1 of CDF Run II data respectively. The measurements, performed in both the electron and muon decay channels, rely on a fit to the W transverse mass distribution. We measure M_W = 80413 +/- 48 MeV and G_W = 2032 +/- 71 MeV which represent the world's single most precise measurements to date.

  17. Compact Pulse Width Modulation Circuitry for Silicon Photomultiplier Readout

    Bieniosek, M F; Olcott, P D; Levin, C. S.

    2013-01-01

    The adoption of solid state photo-detectors for positron emission tomography (PET) system design and the interest in 3D interaction information from PET detectors has lead to an increasing number of readout channels in PET systems. To handle these additional readout channels, PET readout electronics should be simplified to reduce the power consumption, cost, and size of the electronics for a single channel. Pulse width modulation (PWM), where detector pulses are converted to digital pulses wi...

  18. Do coralline red algal growth increment widths archive paleoenvironmental information?

    Halfar, J.; Winsborough, C.; Omar, A.; Hetzinger, S.; Steneck, R. S.; Lebednik, P. A.

    2009-04-01

    Over the past decade coralline red algae have received increased attention as archives of paleoclimate information. Encrusting coralline red algae, which deposit annual growth increments in a High-Mg calcite skeleton, are amongst the longest-lived marine organisms. In fact, a live-collected plant has recently been shown to have lived for at least 850 years based on radiometric dating. While a number of investigations have successfully utilized geochemical information obtained from coralline red algal skeletons to reconstruct climate, no study has yet examined the potential of using growth increment widths as a proxy for past water temperatures. Here we explore the relationship between growth and environmental parameters in Clathromorphum nereostratum from the Bering Sea. A 120-year long annual growth record shows a significant but weak correlation to regional sea surface temperature data (r=0.24), which requires much of the observed annual growth increment width variability to be explained by other factors. We therefore examined coralline red algal growth for a 20-year period in multiple specimens collected along a depth transect from 10 to 35 m water depth. Results demonstrate a significant decrease in average annual growth increment widths with increasing water depth. Due to intense wind-induced mixing in the region the upper water column exhibits near uniform temperatures and salinities, leaving the decreasing amount of light with depth as the dominant variable influencing vertical extension. This was further tested by examining specimens collected at 10 m water depth at different locations receiving distinct amounts of shading provided by 100%, 50%, and 0% kelp canopy coverage. Results indicate a negative relationship between percent kelp canopy coverage and annual growth increment width. It can therefore be concluded that the dominant factor controlling vertical growth in C. nereostratum is light, with temperature only accounting for a small portion of growth

  19. Soft-switching techniques for pulse-width-modulated converters

    Hua, Guichao

    1994-01-01

    The concept of soft-switching pulse-width-modulated (PWM) technique was proposed aimed at combining the advantages of both the conventional PWM technique and the resonant technique. This work presents four new families of soft-switching PWM converters: the zero-voltage-switched (ZVS) PWM converters, the zero-current-switched (ZCS) PWM converters, the zerovoltage- transition (ZVT) PWM converters, and the zero-current-transition (ZCT) PWM converters. The family of ZVS- and ...

  20. Temperature Dependence of Spreading Width of Giant Dipole Resonance

    Storozhenko, A N; Ventura, A; Blokhin, A I

    2002-01-01

    The Quasiparticle-Phonon Nuclear Model extended to finite temperature within the framework of Thermo Field Dynamics is applied to calculate a temperature dependence of the spreading width Gamma^{\\downarrow} of a giant dipole resonance. Numerical calculations are made for ^{120}Sn and ^{208}Pb nuclei. It is found that Gamma^{\\downarrow} increases with T. The reason of this effect is discussed as well as a relation of the present approach to other ones, existing in the literature.

  1. Porous Alumina Films with Width-Controllable Alumina Stripes

    Huang Shi-Ming

    2010-01-01

    Full Text Available Abstract Porous alumina films had been fabricated by anodizing from aluminum films after an electropolishing procedure. Alumina stripes without pores can be distinguished on the surface of the porous alumina films. The width of the alumina stripes increases proportionally with the anodizing voltage. And the pores tend to be initiated close to the alumina stripes. These phenomena can be ascribed to the electric field distribution in the alumina barrier layer caused by the geometric structure of the aluminum surface.

  2. Conjugacy Growth and Conjugacy Width of Certain Branch Groups

    Fink, Elisabeth

    2014-01-01

    The conjugacy growth function counts the number of distinct conjugacy classes in a ball of radius $n$. We give a lower bound for the conjugacy growth of certain branch groups, among them the Grigorchuk group. This bound is a function of intermediate growth. We further proof that certain branch groups have the property that every element can be expressed as a product of uniformly boundedly many conjugates of the generators. We call this property bounded conjugacy width. We also show how bounde...

  3. Porous Alumina Films with Width-Controllable Alumina Stripes

    Huang Shi-Ming; Pu Lin; Shi Yi; Huang Kai; Wu Zhi-Ming; Ji Li; Kang Jun-Yong

    2010-01-01

    Abstract Porous alumina films had been fabricated by anodizing from aluminum films after an electropolishing procedure. Alumina stripes without pores can be distinguished on the surface of the porous alumina films. The width of the alumina stripes increases proportionally with the anodizing voltage. And the pores tend to be initiated close to the alumina stripes. These phenomena can be ascribed to the electric field distribution in the alumina barrier layer caused by the geometric structure o...

  4. Characterizing the width of amphibian movements during postbreeding migration.

    Coster, Stephanie S; Veysey Powell, Jessica S; Babbitt, Kimberly J

    2014-06-01

    Habitat linkages can help maintain connectivity of animal populations in developed landscapes. However, the lack of empirical data on the width of lateral movements (i.e., the zigzagging of individuals as they move from one point to point another) makes determining the width of such linkages challenging. We used radiotracking data from wood frogs (Lithobates sylvaticus) and spotted salamanders (Ambystoma maculatum) in a managed forest in Maine (U.S.A.) to characterize movement patterns of populations and thus inform planning for the width of wildlife corridors. For each individual, we calculated the polar coordinates of all locations, estimated the vector sum of the polar coordinates, and measured the distance from each location to the vector sum. By fitting a Gaussian distribution over a histogram of these distances, we created a population-level probability density function and estimated the 50th and 95th percentiles to determine the width of lateral movement as individuals progressed from the pond to upland habitat. For spotted salamanders 50% of lateral movements were ≤13 m wide and 95% of movements were ≤39 m wide. For wood frogs, 50% of lateral movements were ≤17 m wide and 95% of movements were ≤ 51 m wide. For both species, those individuals that traveled the farthest from the pond also displayed the greatest lateral movement. Our results serve as a foundation for spatially explicit conservation planning for pond-breeding amphibians in areas undergoing development. Our technique can also be applied to movement data from other taxa to aid in designing habitat linkages. PMID:24423254

  5. Topological equivalence of nonlinear autonomous dynamical systems

    We show in this paper that the autonomous nonlinear dynamical system Σ(A,B,F): x' = Ax+Bu+F(x) is topologically equivalent to the linear dynamical system Σ(A,B,O): x' = Ax+Bu if the projection of A on the complement in Rn of the controllable vectorial subspace is hyperbolic and if lipschitz constant of F is sufficiently small (*) and F(x) = 0 when parallel x parallel is sufficiently large (**). In particular, if Σ(A,B,O) is controllable, it is topologically equivalent to Σ(A,B,F) when it is only that F satisfy (**). (author). 18 refs

  6. Equivalence between XY and dimerized models

    Campos Venuti, Lorenzo; Roncaglia, Marco

    2010-06-01

    The spin-1/2 chain with XY anisotropic coupling in the plane and the XX isotropic dimerized chain are shown to be equivalent in the bulk. For finite systems, we prove that the equivalence is exact in given parity sectors, after taking care of the precise boundary conditions. The proof is given constructively by finding unitary transformations that map the models onto each other. Moreover, we considerably generalized our mapping and showed that even in the case of fully site-dependent couplings the XY chain can be mapped onto an XX model. This result has potential application in the study of disordered systems.

  7. Equivalence between XY and dimerized models

    The spin-1/2 chain with XY anisotropic coupling in the plane and the XX isotropic dimerized chain are shown to be equivalent in the bulk. For finite systems, we prove that the equivalence is exact in given parity sectors, after taking care of the precise boundary conditions. The proof is given constructively by finding unitary transformations that map the models onto each other. Moreover, we considerably generalized our mapping and showed that even in the case of fully site-dependent couplings the XY chain can be mapped onto an XX model. This result has potential application in the study of disordered systems.

  8. Atom interferometry and the Einstein equivalence principle

    Wolf, Peter; Bordé, Christian J; Reynaud, Serge; Salomon, Christophe; Cohen-Tannoudji, Clande

    2011-01-01

    The computation of the phase shift in a symmetric atom interferometer in the presence of a gravitational field is reviewed. The difference of action-phase integrals between the two paths of the interferometer is zero for any Lagrangian which is at most quadratic in position and velocity. We emphasize that in a large class of theories of gravity the atom interferometer permits a test of the weak version of the equivalence principle (or universality of free fall) by comparing the acceleration of atoms with that of ordinary bodies, but is insensitive to that aspect of the equivalence principle known as the gravitational redshift or universality of clock rates.

  9. Equivalent circuit analysis of terahertz metamaterial filters

    Zhang, Xueqian

    2011-01-01

    An equivalent circuit model for the analysis and design of terahertz (THz) metamaterial filters is presented. The proposed model, derived based on LMC equivalent circuits, takes into account the detailed geometrical parameters and the presence of a dielectric substrate with the existing analytic expressions for self-inductance, mutual inductance, and capacitance. The model is in good agreement with the experimental measurements and full-wave simulations. Exploiting the circuit model has made it possible to predict accurately the resonance frequency of the proposed structures and thus, quick and accurate process of designing THz device from artificial metamaterials is offered. ©2011 Chinese Optics Letters.

  10. Fiscal adjustments in Europe and Ricardian equivalence

    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. Relative Derived Equivalences and Relative Homological Dimensions

    Sheng Yong PAN

    2016-01-01

    Let A be a small abelian category. For a closed subbifunctor F of Ext1A (−,−), Buan has generalized the construction of Verdier’s quotient category to get a relative derived category, where he localized with respect to F-acyclic complexes. In this paper, the homological properties of relative derived categories are discussed, and the relation with derived categories is given. For Artin algebras, using relative derived categories, we give a relative version on derived equivalences induced by F-tilting complexes. We discuss the relationships between relative homological dimensions and relative derived equivalences.

  12. Two-Pion Decay Widths of Excited Charm Mesons

    Lähde, T A

    2001-01-01

    The widths for $\\pi\\pi$ decay of the L=1 charm mesons are calculated by describing the pion coupling to light constituents quarks by the lowest order chiral interaction. The wavefunctions of the charm mesons are obtained as solutions to the covariant Blankenbecler-Sugar equation. These solutions correspond to an interaction Hamiltonian modeled as the sum of a linear scalar confining and a screened one-gluon exchange (OGE) interaction. This interaction induces a two-quark contribution to the amplitude for two-pion decay, which is found to interfere destructively with the single quark amplitude. For the currently known L=1 $D$ mesons, the total $\\pi\\pi$ decay widths are found to be $\\sim 1$ MeV for the $D_1(2420)$ and $\\sim 3$ MeV for the $D^*_2(2460)$ if the axial coupling of the constituent quark is taken to be $g_A^q=1$. The as yet undiscovered spin singlet $D_1^*$ state is predicted to have a larger width of 7 - 10 MeV for $\\pi\\pi$ decay.

  13. Evolution and diversity of subduction zones controlled by slab width.

    Schellart, W P; Freeman, J; Stegman, D R; Moresi, L; May, D

    2007-03-15

    Subducting slabs provide the main driving force for plate motion and flow in the Earth's mantle, and geodynamic, seismic and geochemical studies offer insight into slab dynamics and subduction-induced flow. Most previous geodynamic studies treat subduction zones as either infinite in trench-parallel extent (that is, two-dimensional) or finite in width but fixed in space. Subduction zones and their associated slabs are, however, limited in lateral extent (250-7,400 km) and their three-dimensional geometry evolves over time. Here we show that slab width controls two first-order features of plate tectonics-the curvature of subduction zones and their tendency to retreat backwards with time. Using three-dimensional numerical simulations of free subduction, we show that trench migration rate is inversely related to slab width and depends on proximity to a lateral slab edge. These results are consistent with retreat velocities observed globally, with maximum velocities (6-16 cm yr(-1)) only observed close to slab edges (2,000 km) retreat velocities are always slow ( or =4,000 km) are nearly stationary in the centre and develop a convex geometry, whereas trench retreat increases towards concave-shaped edges. Additionally, we identify periods (5-10 Myr) of slow trench advance at the centre of wide slabs. Such wide-slab behaviour may explain mountain building in the central Andes, as being a consequence of its tectonic setting, far from slab edges. PMID:17361181

  14. Combining LEP and LHC to bound the Higgs width

    Englert, Christoph; McCullough, Matthew; Spannowsky, Michael

    2016-01-01

    The correlation of on- and off-shell Higgs boson production at the LHC in gg →h* → ZZ has been used to bound the Higgs width. We propose an alternative complementary constraint which is only possible through the combination of LEP and LHC measurements. Precision electroweak measurements at LEP allow for the determination of indirect constraints on Higgs couplings to vector bosons by considering one-loop processes involving virtual Higgs exchange. As the indirect constraint is model dependent we will consider two specific models which modify the Higgs couplings and width, and our results will apply specifically to these models. By combining these LEP constraints with current LHC 8 TeV Higgs measurements a stronger limit on the Higgs width can be achieved than with LHC data alone. Looking to the future, a more robust constraint can be achieved by correlating LEP measurements with WBF Higgs production followed by Higgs decays to WW and ZZ. We will discuss the model dependence of this method in comparison to other proposed methods.

  15. The lineshape problem in Doppler-width thermometry

    Domenica De Vizia, Maria; Moretti, Luigi; Castrillo, Antonio; Fasci, Eugenio; Gianfrani, Livio

    2011-09-01

    Typically eliminated in any experiment of time and frequency metrology, the Doppler broadening effect can be regarded as a gift of nature for the purpose of measuring the thermodynamic temperature of a gaseous sample. Nevertheless, Doppler-width retrieval from highly-accurate absorption spectra is surely not an easy task as it requires an adequate knowledge of the lineshape function, accounting for the different mechanisms that contribute to the overall linewidth. Semiclassical theories provide several possibilities, more or less accurate in reproducing the observed profiles. Here, the influence of the choice of the lineshape model in Doppler-width thermometry is investigated in the physical situation of self-colliding ? O molecules. A large number of absorption profiles were simulated, using the uncorrelated version of the speed-dependent Galatry profile and setting different values for the gas pressure, the signal-to-noise ratio and the Dicke-narrowing parameter. Spectral analysis was performed by means of different models, in order to retrieve the zero-pressure value of the Doppler width. It turned out that precision and accuracy can be pushed to extreme levels provided that the signal-to-noise ratio is sufficiently high (namely, larger than 50,000) and that a speed-dependent lineshape model is used.

  16. Measurement of the mass and width of the W boson

    Abbiendi, G; Åkesson, P F; Alexander, G; Allison, J; Amaral, P; Anagnostou, G; Anderson, K J; Asai, S; Axen, D A; Bailey, I; Barberio, E; Barillari, T; Barlow, R J; Batley, J Richard; Bechtle, P; Behnke, T; Bell, K W; Bell, P J; Bella, G; Bellerive, A; Benelli, G; Bethke, Siegfried; Biebel, O; Boeriu, O; Bock, P; Boutemeur, M; Braibant, S; Brown, R M; Burckhart, H J; Campana, S; Carnegie, R K; Carter, A A; Carter, J R; Chang, C Y; Charlton, D G; Ciocca, C; Csilling, A; Cuffiani, M; Dado, S; de Roeck, A; De Wolf, E A; Desch, Klaus; Dienes, B; Donkers, M; Dubbert, J; Duchovni, E; Duckeck, G; Duerdoth, I P; Etzion, E; Fabbri, Franco Luigi; Fanfani, A; Ferrari, P; Fiedler, F; Fleck, I; Ford, M; Frey, A; Gagnon, P; Gary, J W; Geich-Gimbel, C; Giacomelli, G; Giacomelli, P; Giunta, M; Goldberg, J; Gross, E; Grunhaus, Jacob; Gruwé, M; Günther, P O; Sen-Gupta, A; Hajdu, C; Hamann, M; Hanson, G G; Harel, A; Hauschild, M; Hawkes, C M; Hawkings, R; Hemingway, R J; Herten, G; Heuer, R D; Hill, J C; Hoffman, K; Horváth, D; Igo-Kemenes, P; Ishii, K; Jeremie, H; Jovanovic, P; Junk, T R; Kanzaki, J; Karlen, Dean A; Kawagoe, K; Kawamoto, T; Keeler, R K; Kellogg, R G; Kennedy, B W; Kluth, S; Kobayashi, T; Kobel, M; Komamiya, S; Kramer, T; Krieger, P; Von Krogh, J; Kühl, T; Kupper, M; Lafferty, G D; Landsman, Hagar Yaël; Lanske, D; Lellouch, D; Letts, J; Levinson, L; Lillich, J; Lloyd, S L; Loebinger, F K; Lü, J; Ludwig, A; Ludwig, J; Mader, W; Marcellini, S; Martin, A J; Masetti, G; Mashimo, T; Mättig, P; McKenna, J A; McPherson, R A; Meijers, F; Menges, W; Merritt, F S; Mes, H; Meyer, N; Michelini, A; Mihara, S; Mikenberg, G; Miller, D J; Mohr, W; Montanari, A; Mori, T; Mutter, A; Nagai, K; Nakamura, I; Nanjo, H; Neal, H A; Nisius, R; O'Neale, S W; Oh, A; Oreglia, M J; Orito, S; Pahl, C; Pásztor, G; Pater, J R; Pilcher, J E; Pinfold, J L; Plane, D E; Pooth, O; Przybycien, M B; Quadt, A; Rabbertz, K; Rembser, C; Renkel, P; Roney, J M; Rozen, Y; Runge, K; Sachs, K; Saeki, T; Sarkisyan-Grinbaum, E; Schaile, A D; Schaile, O; Scharff-Hansen, P; Schieck, J; Schörner-Sadenius, T; Schröder, M; Schumacher, M; Seuster, R; Shears, T G; Shen, B C; Sherwood, P; Skuja, A; Smith, A M; Sobie, R J; Söldner-Rembold, S; Spanó, F; Stahl, A; Strom, D; Ströhmer, R; Tarem, S; Tasevsky, M; Teuscher, R; Thomson, M A; Torrence, E; Toya, D; Tran, P; Trigger, I; Trócsányi, Z L; Tsur, E; Turner-Watson, M F; Ueda, I; Ujvári, B; Vollmer, C F; Vannerem, P; Vertesi, R; Verzocchi, M; Voss, H; Vossebeld, Joost Herman; Ward, C P; Ward, D R; Watkins, P M; Watson, A T; Watson, N K; Wells, P S; Wengler, T; Wermes, N; Wilson, G W; Wilson, J A; Wolf, G; Wyatt, T R; Yamashita, S; Zer-Zion, D; Zivkovic, L

    2006-01-01

    The mass and width of the W boson are measured using e+e- -> W+W- events from the data sample collected by the OPAL experiment at LEP at centre-of-mass energies between 170 GeV and 209 GeV. The mass (mw) and width (gw) are determined using direct reconstruction of the kinematics of W+W- -> qqbarlv and W+W- -> qqbarqqbar events. When combined with previous OPAL measurements using W+W- -> lvlv events and the dependence on mw of the WW production cross-section at threshold, the results are determined to be mw = 80.415 +- 0.042 +- 0.030 +- 0.009 GeV gw = 1.996 +- 0.096 +- 0.102 +- 0.003 GeV where the first error is statistical, the second systematic and the third due to uncertainties in the value of the LEP beam energy. By measuring mw with several different jet algorithms in the qqbarqqbar channel, a limit is also obtained on possible final-state interactions due to colour reconnection effects in W+W- -> qqbarqqbar events. The consistency of the results for the W mass and width with those inferred from other ele...

  17. A New Measurement of the Pi0 Radiative Decay Width

    Larin, I; Clinton, E; Ambrozewicz, P; Lawrence, D; Nakagawa, I; Prok, Y; Teymurazyan, A; Ahmidouch, A; Baker, K; Benton, L; Bernstein, A M; Burkert, V; Cole, P; Collins, P; Dale, D; Danagoulian, S; Davidenko, G; Demirchyan, R; Deur, A; Dolgolenko, A; Dzyubenko, Georgiy; Ent, R; Evdokimov, A; Feng, J; Gabrielyan, M; Gan, L; Gasparian, A; Gevorkyan, S; Glamazdin, A; Goryachev, V; Gyurjyan, V; Hardy, K; He, J; Ito, M; Jiang, L; Kashy, D; Khandaker, M; Kingsberry, P; Kolarkar, A; Konchatnyi, M; Korsch, W; Kowalski, S; Kubantsev, M; Kubarovsky, V; Li, X; Martel, P; Mecking, B; Milbrath, B; Minehart, R; Miskimen, R; Mochalov, V; Mtingwa, S; Overby, S; Pasyuk, E; Payen, M; Pedroni, R; Ritchie, B; Rodrigues, T E; Salgado, C; Shahinyan, A; Sitnikov, A; Sober, D; Stepanyan, S; Stephens, W; Underwood, J; Vishnyakov, V; Wood, M

    2011-04-01

    High precision measurements of the differential cross sections for $\\pi^0$ photoproduction at forward angles for two nuclei, $^{12}$C and $^{208}$Pb, have been performed for incident photon energies of 4.9 - 5.5 GeV to extract the ${\\pi^0 \\to \\gamma\\gamma}$ decay width. The experiment was done at Jefferson Lab using the Hall~B photon tagger and a high-resolution multichannel calorimeter. The ${\\pi^0 \\to \\gamma\\gamma}$ decay width was extracted by fitting the measured cross sections using recently updated theoretical models for the process. The resulting value for the decay width is $\\Gamma{(\\pi^0 \\to \\gamma\\gamma)} = 7.82 \\pm 0.14 ~({\\rm stat.}) \\pm 0.17 ~({\\rm syst.}) ~{\\rm eV}$. With the 2.8\\% total uncertainty, this result is a factor of 2.5 more precise than the current PDG average of this fundamental quantity and it is consistent with current theoretical predictions.

  18. Pulse width control loop as a duty cycle corrector

    Jovanović Goran

    2004-01-01

    Full Text Available The clock distribution and generation circuitry forms a critical component of current synchronous digital systems. A digital system’s clocks must have not only low jitter, low skew, but also well-controlled duty cycle in order to facilitate versatile clocking techniques. In high-speed CMOS clock buffer design, the duty cycle of a clock is liable to be changed when the clock passes through a multistage buffer because the circuit is not pure digital [8]. In this paper, we propose a pulse width control loop referred as MPWCL (modified pulse width control loop that adopts the same architecture as the conventional PWCL, but with a new pulse generator and new charge pump circuit as a constituent of the duty cycle detector. Thanks to using new building blocks the proposed pulse width control loop can control the duty cycle in a wide range, and what is more important it becomes operative in saturation region too, what provides conditional for fast locking time. For 1.2 µm double-metal double-poly CMOS process with Vdd = 5 V and operating frequency of 133 MHz, results of SPICE simulation show that the duty cycle can be well controlled in the range from 20 % up to 80 % if the loop parameters are properly chosen.

  19. Maxillary and mandibular anterior crown width/height ratio and its relation to various arch perimeters, arch length, and arch width groups

    Shahid, Fazal; Alam, Mohammad Khursheed; Khamis, Mohd Fadhli

    2015-01-01

    Objective: To investigate the maxillary and mandibular anterior crown width/height ratio and its relation to various arch perimeters, arch length, and arch width (intercanine, interpremolar, and intermolar) groups. Materials and Methods: The calculated sample size was 128 subjects. The crown width/height, arch length, arch perimeter, and arch width of the maxilla and mandible were obtained via digital calliper (Mitutoyo, Japan). A total of 4325 variables were measured. The sex differences in the crown width and height were evaluated. Analysis of variance was applied to evaluate the differences between arch length, arch perimeter, and arch width groups. Results: Males had significantly larger mean values for crown width and height than females (P ≤ 0.05) for maxillary and mandibular arches, both. There were no significant differences observed for the crown width/height ratio in various arch length, arch perimeter, and arch width (intercanine, interpremolar, and intermolar) groups (P ≤ 0.05) in maxilla and mandible, both. Conclusions: Our results indicate sexual disparities in the crown width and height. Crown width and height has no significant relation to various arch length, arch perimeter, and arch width groups of maxilla and mandible. Thus, it may be helpful for orthodontic and prosthodontic case investigations and comprehensive management. PMID:26929686

  20. Comparing Fixed and Variable-Width Gaussian Networks

    Kůrková, Věra; Kainen, P.C.

    2014-01-01

    Roč. 57, September (2014), s. 23-28. ISSN 0893-6080 R&D Projects: GA MŠk(CZ) LD13002 Institutional support: RVO:67985807 Keywords : Gaussian radial and kernel networks * Functionally equivalent networks * Universal approximators * Stabilizers defined by Gaussian kernels * Argminima of error functionals Subject RIV: IN - Informatics, Computer Science Impact factor: 2.708, year: 2014

  1. Are Aryabhata's and Galilean Relativity Equivalent?

    Narayan, R. H.

    2008-01-01

    This paper considers the question of whether Aryabhata's direct and indirect references to relativity of motion are equivalent to Galilean Relativity. Examining verses fom different sections of the text Aryabhatiya, we show that there is explicit mention of relativity of space and motion, although there is no explicit reference to the motion being uniform.

  2. Reading adn Auditory-Visual Equivalences

    Sidman, Murray

    1971-01-01

    A retarded boy, unable to read orally or with comprehension, was taught to match spoken to printed words and was then capable of reading comprehension (matching printed words to picture) and oral reading (naming printed words aloud), demonstrating that certain learned auditory-visual equivalences are sufficient prerequisites for reading…

  3. Structural Equivalence in a Journal Network.

    Doreian, Patrick; Fararo, Thomas J.

    1985-01-01

    Techniques used in contemporary social network analysis are applied to citation data for a network of journals from three time periods--1970/71, 1975/76, 1980/81. Blocks or positions in journal network based on structural equivalence correspond closely to categorization by aims and objectives. Hypotheses concerning journal networks are advanced.…

  4. GIT-equivalence and diagonal actions

    Kotenkova, Polina Yu.

    2010-01-01

    We describe the GIT-equivalence classes of linearized ample line bundles for the diagonal actions of the linear algebraic groups $SL(V)$ and $SO(V)$ on ${\\mathbb{P}(V)^{m_1}\\times \\mathbb{P}(V^*)^{m_2}}$ and $\\mathbb{P}(V)^m$ respectively.

  5. Equivalence of energy methods in stability theory

    Birtea, Petre; Puta, Mircea

    2006-01-01

    We will prove the equivalence of three methods, the so called energy methods, for establishing the stability of an equilibrium point for a dynamical system. We will illustrate by examples that this result simplifies enormously the amount of computations especially when the stability can not be decided with one of the three methods.

  6. Equivalent substitution in the control theory

    Proudnikov, Igor

    2012-01-01

    A system of differential equations with control is considered. A rule for equivalent substitution of this system is given. The system of differential equations is changed for two systems with upper and lower approximation functions of a function on the right side of the initial system in a region of attainability.

  7. THE EQUIVALENCE THEORY OF NATIVE SPACES

    Lin-Tian Luh

    2001-01-01

    In this paper some equivalence definitions are given for native spaces which were introduced by Madych and Nelson and have become influential in the theory of radial basis functions. The abstract elements in na tive spaces are interpreted. Moreaver, Weinrich and Iske's theonies are unified.

  8. Equivalence Scales for the Former West Germany

    Charlier, E.

    1997-01-01

    Equivalence scales provide answers to questions like how much a household with four children needs to spend compared to a household with two children or how much a childless couple needs to spend compared to a single person household to attain the same welfare level. These are important questions fo

  9. An Equivalent Circuit for Landau Damping

    Pécseli, Hans

    1976-01-01

    An equivalent circuit simulating the effect of Landau damping in a stable plasma‐loaded parallel‐plate capacitor is presented. The circuit contains a double infinity of LC components. The transition from stable to unstable plasmas is simulated by the introduction of active elements into the circuit....

  10. Pseudo-Equivalent Groups and Linking

    Haberman, Shelby J.

    2015-01-01

    Adjustment by minimum discriminant information provides an approach to linking test forms in the case of a nonequivalent groups design with no satisfactory common items. This approach employs background information on individual examinees in each administration so that weighted samples of examinees form pseudo-equivalent groups in the sense that…

  11. On the Equivalence of Regularization Schemes

    YANG Ji-Feng

    2002-01-01

    We illustrate via the sunset diagram that dimensional regularization ‘deforms' the nonlocal contentsof multi-loop diagrams with its equivalence to cutoff regularization scheme recovered only after sub-divergence wassubtracted. Then we employed a differential equation approach for calculating loop diagrams to verify that dimensionalare argued especially in nonperturbativc perspective.

  12. Confluence Modulo Equivalence in Constraint Handling Rules

    Christiansen, Henning; Kirkeby, Maja Hanne

    2014-01-01

    Previous results on confluence for Constraint Handling Rules, CHR, are generalized to take into account user-defined state equivalence relations. This allows a much larger class of programs to enjoy the ad- vantages of confluence, which include various optimization techniques and simplified corre...

  13. Equivalent thermal conductivity of heat pipes

    Zesheng LU; Binghui MA

    2008-01-01

    In precision machining, the machining error from thermal distortion carries a high proportion of the total errors. If a precision machining tool can transfer heat fast, the thermal distortion will be reduced and the machining precision will be improved. A heat pipe working based on phase transitions of the inner working liquid transfers heat with high efficiency and is widely applied in spaceflight and chemical industries. In mechanics, applications of heat pipes are correspondingly less. When a heat pipe is applied to a hydrostatic motor-ized spindle, the thermal distortion cannot be solved dur-ing the heat transfer process because thermal conductivity or equivalent thermal conductivity should be provided first for special application in mechanics. An equivalent thermal conductivity model based on equivalent thermal resistances is established. Performance tests for a screen wick pipe, gravity pipe, and rotation heat pipe are done to validate the efficiency of the equivalent thermal conduc-tivity model. The proposed model provides a calculation method for the thermal distortion analysis of heat pipes applied in the motorized spindle.

  14. Confluence Modulo Equivalence in Constraint Handling Rules

    Christiansen, Henning; Kirkeby, Maja Hanne

    2015-01-01

    Previous results on confluence for Constraint Handling Rules, CHR, are generalized to take into account user-defined state equivalence relations. This allows a much larger class of programs to enjoy the advantages of confluence, which include various optimization techniques and simplified...

  15. Average Equivalent Diameter of A Particulate Material

    AL-MAGHRABI, Mohammed-Noor N. H.

    2010-01-01

    In the field of mineral processing, it is important to determine the size of a particle. A method of defining an average diameter for a collection of particles is presented. The theoretical basis developed for the purpose is verified by a specially designed experimental technique.  Key words: mineral processing, particle size, equivalent diameter

  16. CP Violation, Neutral Currents, and Weak Equivalence

    Fitch, V. L.

    1972-03-23

    Within the past few months two excellent summaries of the state of our knowledge of the weak interactions have been presented. Correspondingly, we will not attempt a comprehensive review but instead concentrate this discussion on the status of CP violation, the question of the neutral currents, and the weak equivalence principle.

  17. Equivalent weight of humic acid from peat

    Pommer, A.M.; Breger, I.A.

    1960-01-01

    By means of discontinuous titration, the equivalent weight of humic acid isolated from a peat was found to increase from 144 to 183 between the third and fifty-second day after the humic acid was dissolved. Infra-red studies showed that the material had probably condensed with loss of carbonyl groups. ?? 1960.

  18. Covering line graphs with equivalence relations

    Esperet, L; King, A

    2010-01-01

    An equivalence graph is a disjoint union of cliques, and the equivalence number $\\mathit{eq}(G)$ of a graph $G$ is the minimum number of equivalence subgraphs needed to cover the edges of $G$. We consider the equivalence number of a line graph, giving improved upper and lower bounds: $\\frac 13 \\log_2\\log_2 \\chi(G) < \\mathit{eq}(L(G)) \\leq 2\\log_2\\log_2 \\chi(G) + 2$. This disproves a recent conjecture that $\\mathit{eq}(L(G))$ is at most three for triangle-free $G$; indeed it can be arbitrarily large. To bound $\\mathit{eq}(L(G))$ we bound the closely-related invariant $\\sigma(G)$, which is the minimum number of orientations of $G$ such that for any two edges $e,f$ incident to some vertex $v$, both $e$ and $f$ are oriented out of $v$ in some orientation. When $G$ is triangle-free, $\\sigma(G)=\\mathit{eq}(L(G))$. We prove that even when $G$ is triangle-free, it is NP-complete to decide whether or not $\\sigma(G)\\leq 3$.

  19. Analysis and Minimization of Output Current Ripple for Discontinuous Pulse-Width Modulation Techniques in Three-Phase Inverters

    Gabriele Grandi

    2016-05-01

    Full Text Available This paper gives the complete analysis of the output current ripple in three-phase voltage source inverters considering the different discontinuous pulse-width modulation (DPWM strategies. In particular, peak-to-peak current ripple amplitude is analytically evaluated over the fundamental period and compared among the most used DPWMs, including positive and negative clamped (DPWM+ and DPWM−, and the four possible combinations between them, usually named as DPWM0, DPWM1, DPWM2, and DPWM3. The maximum and the average values of peak-to-peak current ripple are estimated, and a simple method to correlate the ripple envelope with the ripple rms is proposed and verified. Furthermore, all the results obtained by DPWMs are compared to the centered pulse-width modulation (CPWM, equivalent to the space vector modulation to identify the optimal pulse-width modulation (PWM strategy as a function of the modulation index, taking into account the different average switching frequency. In this way, the PWM technique providing for the minimum output current ripple is identified over the whole modulation range. The analytical developments and the main results are experimentally verified by current ripple measurements with a three-phase PWM inverter prototype supplying an induction motor load.

  20. Beam width evolution of astigmatic hollow Gaussian beams in highly nonlocal nonlinear media

    Yang, Zhen-Feng; Jiang, Xue-Song; Yang, Zhen-Jun; Li, Jian-Xing; Zhang, Shu-Min

    We investigate the beam width evolution of astigmatic hollow Gaussian beams propagating in highly nonlocal nonlinear media. The input-power-induced different evolutions of the beam width are illustrated: (i) the beam widths in two transverse directions are compressed or broadened at the same time; (ii) the beam width in one transverse direction keeps invariant, and the other is compressed or broadened; (iii) furthermore, the beam width in one transverse direction is compressed, whereas it in the other transverse direction is broadened.

  1. Analysis Of The Effect Of Flow Channel Width On The Performance Of PEMFC

    Elif Eker

    2013-08-01

    Full Text Available In this work, it was analysed the effect of different channel width on performance of PEM fuel cell. Current density were measured on the single cells of parallel flow fields that has 25 cm² active layer, using three different kinds of channel width. The cell width and the channel height remain constant.The results show that increasing the channel width while the cell width remains constant decreases the current density.

  2. Size of the intracranial optic nerve and optic tract in neonates at term-equivalent age at magnetic resonance imaging

    The expected MRI-based dimensions of the intracranial optic nerve and optic tract in neonates are unknown. To evaluate the sizes of the intracranial optic nerve and optic tract in neonates at term-equivalent age using MRI. We retrospectively analyzed brain MRI examinations in 62 infants (28 boys) without intracranial abnormalities. The images were obtained in infants at term-equivalent age with a 1.5-tesla MRI scanner. We measured the widths and heights of the intracranial optic nerve and optic tract and calculated the cross-sectional areas using the formula for an ellipse. The means ± standard deviation of the width, height and cross-sectional area of the intracranial optic nerve were 2.7 ± 0.2 mm, 1.7 ± 0.2 mm and 3.5 ± 0.5 mm2, respectively. The width, height and cross-sectional area of the optic tract were 1.5 ± 0.1 mm, 1.6 ± 0.1 mm and 2.0 ± 0.2 mm2, respectively. Using univariate and multivariate analyses, we found that postmenstrual age showed independent intermediate positive correlations with the width (r = 0.48, P < 0.01) and cross-sectional area (r = 0.40, P < 0.01) of the intracranial optic nerve. The lower bounds of the 95% prediction intervals for the width and cross-sectional area of the intracranial optic nerve were 0.07 x (postmenstrual age in weeks) - 0.46 mm, and 0.17 x (postmenstrual age in weeks) - 4.0 mm2, respectively. We identified the sizes of the intracranial optic nerve and optic tract in neonates at term-equivalent age. The postmenstrual age at MRI independently positively correlated with the sizes. (orig.)

  3. Size of the intracranial optic nerve and optic tract in neonates at term-equivalent age at magnetic resonance imaging

    Oyama, Jun; Mori, Kouichi [Tsuchiura Kyodo General Hospital, Department of Radiology, Tsuchiura, Ibaraki (Japan); Imamura, Masatoshi [Tsuchiura Kyodo General Hospital, Department of Neonatology, Tsuchiura, Ibaraki (Japan); Mizushima, Yukiko [Tsuchiura Kyodo General Hospital, Department of Ophthalmology, Tsuchiura, Ibaraki (Japan); Tateishi, Ukihide [Tokyo Medical and Dental University, Departments of Diagnostic Radiology and Nuclear Medicine, Tokyo (Japan)

    2016-04-15

    The expected MRI-based dimensions of the intracranial optic nerve and optic tract in neonates are unknown. To evaluate the sizes of the intracranial optic nerve and optic tract in neonates at term-equivalent age using MRI. We retrospectively analyzed brain MRI examinations in 62 infants (28 boys) without intracranial abnormalities. The images were obtained in infants at term-equivalent age with a 1.5-tesla MRI scanner. We measured the widths and heights of the intracranial optic nerve and optic tract and calculated the cross-sectional areas using the formula for an ellipse. The means ± standard deviation of the width, height and cross-sectional area of the intracranial optic nerve were 2.7 ± 0.2 mm, 1.7 ± 0.2 mm and 3.5 ± 0.5 mm{sup 2}, respectively. The width, height and cross-sectional area of the optic tract were 1.5 ± 0.1 mm, 1.6 ± 0.1 mm and 2.0 ± 0.2 mm{sup 2}, respectively. Using univariate and multivariate analyses, we found that postmenstrual age showed independent intermediate positive correlations with the width (r = 0.48, P < 0.01) and cross-sectional area (r = 0.40, P < 0.01) of the intracranial optic nerve. The lower bounds of the 95% prediction intervals for the width and cross-sectional area of the intracranial optic nerve were 0.07 x (postmenstrual age in weeks) - 0.46 mm, and 0.17 x (postmenstrual age in weeks) - 4.0 mm{sup 2}, respectively. We identified the sizes of the intracranial optic nerve and optic tract in neonates at term-equivalent age. The postmenstrual age at MRI independently positively correlated with the sizes. (orig.)

  4. Development and characterisation of a new line width reference material

    A new critical dimension (CD, often synonymously used for line width) reference material with improved vertical parallel sidewalls (IVPSs) has been developed and characterised. The sample has a size of 6 mm  ×  6 mm, consisting of 4 groups of 5  ×  5 feature patterns. Each feature pattern has a group of five reference line features with a nominal CD of 50 nm, 70 nm, 90 nm, 110 nm and 130 nm, respectively. Each feature pattern includes a pair of triangular alignment marks, applicable for precisely identifying the target measurement position, e.g. for comparison or calibration between different tools. The geometry of line features has been investigated thoroughly using a high-resolution transmission electron microscope and a CD atomic force microscope (CD-AFM). Their results indicate the high quality of the line features: the top corner radius of  <7 nm, vertical sidewall (slope mostly within 90°  ±  0.5°) and very small line width variation (LWR down to 0.36 nm). The application of the developed sample for calibrating the scaling factor and effective tip geometry of the CD-AFM are demonstrated. The scaling factor of the CD-AFM is calibrated to be 0.9988, coinciding well with the theoretical value 1 as the tool was calibrated to a traceable metrological atomic force microscope. The effective width of a CDR120-EBD tip is calibrated as 128.32 nm. Finally, a strategy for the non-destructive calibration of the developed sample is introduced, which enables the application of the reference material in practice. (paper)

  5. Radial Regge trajectories and leptonic widths of the isovector mesons

    Badalian, A. M.; Bakker, B. L. G.

    2016-04-01

    It is shown that two physical phenomena are important for high excitations: (i) the screening of the universal gluon-exchange potential and (ii) the flattening of the confining potential owing to creation of quark loops, and both effects are determined quantitatively. Taking the first effect into account, we predict the masses of the ground states with l =0 , 1, 2 in agreement with experiment. The flattening effect ensures the observed linear behavior of the radial Regge trajectories M2(n )=m02+nrμ2 GeV2, where the slope μ2 is very sensitive to the parameter γ , which determines the weakening of the string tension σ (r ) at large distances. For the ρ trajectory the linear behavior starts with nr=1 and the values μ2=1.40 (2 ) GeV2 for γ =0.40 and μ2=1.34 (1 ) GeV2 for γ =0.45 are obtained. For the excited states the leptonic widths Γee(ρ (775 ))=7.0 (3 ) keV , Γee(ρ (1450 ))=1.7 (1 ) keV , Γee(ρ (1900 ))=1.0 (1 ) keV , Γee(ρ (2150 ))=0.7 (1 ) keV , and Γee(1 3D1)=0.26 (5 ) keV are calculated, if these states are considered as purely q q ¯ states. The width Γee(ρ (1700 )) increases if ρ (1700 ) is mixed with the 2 3S1 state, giving for a mixing angle θ =21 ° almost equal widths: Γee(ρ (1700 ))=0.75 (6 ) keV and Γee(1450 )=1.0 (1 ) keV .

  6. Influence of diffusion on the Moessbauer line width

    We have analytically calculated the change of the Moessbauerline due to diffusion of Moessbaueratoms. The correlation effects due to diffusion via the vacancy mechanism have been taken into account. Starting from kinetic equations for single-particle and two-particle densities we have derived an effective equation for the diffusion of Moessbaueratoms using a superposition approximation valid for small vacancy concentrations. This yields the well-known 'encounter-model' which describes the motion of a Moessbaueratom as the result of the action of single vacancies which induce jumps of the Moessbaueratom independently and (due to the small vacancy concentration) consecutively in time. The jumps of the Moessbaueratoms are described by an effective jump frequency matrix whose range extends beyond nearest neighbours because a single vacancy can induce more than one jump of a Moessbaueratom. Due to the correlation of all jumps induced by a single vacancy the effective jump frequency matrix is time dependent. Since the probability for more than one jump of a Moessbaueratom with a single vacancy decreases exponentially with the number of jumps one can use an iteration procedure with respect to the number of Moessbaueratom jumps to calculate the jump frequency matrix. Using an iteration to the second jump we have calculated the self-correlation function of a Moessbaueratom and the resulting change of the Moessbauerline in a single crystal. The result is approximately a broadened Lorentzian line. For the large wave numbers relevant to Moessbauereffect the width varies strongly with the direction of the emission of the Moessbauer quanta relative to the crystal axes. The correlation of the jumps of the Moessbaueratom results in a reduction of the jump frequency and thus of the width, but it also changes the anisotropy of the width and its dependence on the wavenumber. The results are compared with existing theories used to interprete experimental results. (orig.)

  7. Behavior of Li abundances in solar-analog stars. Evidence for line-width dependence

    Takeda, Y.; Kawanomoto, S.; Honda, S.; Ando, H.; Sakurai, T.

    2007-06-01

    Context: It is known that the surface lithium abundances of field solar-analog G dwarfs show a large dispersion of ⪆2 dex (among which our Sun is located at the lower end) despite the similarity of stellar parameters, and planet-host stars tend to show comparatively lower Li abundances in the narrow T_eff range. Aims: To investigate the reason for these phenomena, an extensive study of Li abundances and their dependence on stellar parameters was carried out for a homogeneous sample of 118 selected solar analogs based on high-dispersion spectra obtained at Okayama Astrophysical Observatory. Methods: The atmospheric parameters were spectroscopically determined by using the equivalent widths of Fe i and Fe ii lines, the ages/masses were estimated from stellar evolutionary tracks, and the width of the macrobroadening (rotation plus macroturbulence) function as well as Li abundances (A_Li) were established by spectrum-fitting analyses. Results: The resulting A_Li vs. T_eff relation revealed a characteristic inverse-triangle-like distribution enclosed by two clear-cut boundaries (the slanted one running from ~5900 K to ~5800 K and the vertical one at ~5700 K), while the Sun is located around its lowest apex. More significantly, A_Li in this region of large dispersion was found to closely correlate with the macrobroadening width (v_r+m), which is considered to be the most important parameter. Conclusions: With a reasonable assumption that the difference of rotational velocity is mainly responsible for the variety of v_r+m, we may conclude that the stellar angular momentum plays the decisive role in determining the surface Li abundances of solar-analog stars in the T_eff range of ~5900-5700 K. The low-Li tendency of planet-host stars may thus be interpreted in terms of rotational characteristics. Based on observations carried out at Okayama Astrophysical Observatory (Okayama, Japan). Tables 2-6 are only available in electronic form at the CDS via anonymous ftp to cdsarc

  8. Pulse-width modulated DC-DC power converters

    Kazimierczuk, Marian K

    2008-01-01

    This book studies switch-mode power supplies (SMPS) in great detail. This type of converter changes an unregulated DC voltage into a high-frequency pulse-width modulated (PWM) voltage controlled by varying the duty cycle, then changes the PWM AC voltage to a regulated DC voltage at a high efficiency by rectification and filtering. Used to supply electronic circuits, this converter saves energy and space in the overall system. With concept-orientated explanations, this book offers state-of-the-art SMPS technology and promotes an understanding of the principle operations of PWM converters,

  9. Josephson effect in mesoscopic graphene strips with finite width

    Moghaddam, Ali G.; Zareyan, Malek

    2006-01-01

    We study Josephson effect in a ballistic graphene strip of length $L$ smaller than the superconducting coherence length and arbitrary width $W$. We find that the dependence of the critical supercurrent $I_{c}$ on $W$ is drastically different for different types of the edges. For \\textit{smooth} and \\textit{armchair} edges at low concentration of the carriers $I_{c}$ decreases monotonically with decreasing $W/L$ and tends to a constant minimum for a narrow strip $W/L\\lesssim1$. The minimum sup...

  10. Orbit width scaling of TAE instability growth rate

    The growth rate of Toroidal Alfven Eigenmodes (TAE) driven unstable by resonant coupling of energetic charged particles is evaluated in the ballooning limit over a wide range of parameters. All damping effects are ignored. Variations in orbit width, aspect ratio, and the ratio of alfven velocity to energetic particle birth velocity, are explored. The relative contribution of passing and trapped particles, and finite Larmor radius effects, are also examined. The phase space location of resonant particles with interact strongly with the modes is described. The accuracy of the analytic results with respect to growth rate magnitude and parametric dependence is investigated by comparison with numerical results

  11. Strong-interaction shifts and widths of kaonic helium isotopes

    The kaonic 3He and 4He 3d→2p transitions in gaseous targets were observed by the SIDDHARTA experiment. The X-ray energies of these transitions were measured with large-area silicon-drift detectors using the timing information of the K+K− pairs produced by the DAΦNE e+e− collider. The strong-interaction shifts and widths both of the kaonic 3He and 4He 2p states were determined, which are much smaller than the results obtained by the previous experiments. The “kaonic helium puzzle” (a discrepancy between theory and experiment) was now resolved

  12. Representing Identity and Equivalence for Scientific Data

    Wickett, K. M.; Sacchi, S.; Dubin, D.; Renear, A. H.

    2012-12-01

    Matters of equivalence and identity are central to the stewardship of scientific data. In order to properly prepare for and manage the curation, preservation and sharing of digitally-encoded data, data stewards must be able to characterize and assess the relationships holding between data-carrying digital resources. However, identity-related questions about resources and their information content may not be straightforward to answer: for example, what exactly does it mean to say that two files contain the same data, but in different formats? Information content is frequently distinguished from particular representations, but there is no adequately developed shared understanding of what this really means and how the relationship between content and its representations hold. The Data Concepts group at the Center for Informatics Research in Science and Scholarship (CIRSS), University of Illinois at Urbana Champaign, is developing a logic-based framework of fundamental concepts related to scientific data to support curation and integration. One project goal is to develop precise accounts of information resources carrying the same data. We present two complementary conceptual models for information representation: the Basic Representation Model (BRM) and the Systematic Assertion Model (SAM). We show how these models provide an analytical account of digitally-encoded scientific data and a precise understanding of identity and equivalence. The Basic Representation Model identifies the core entities and relationships involved in representing information carried by digital objects. In BRM, digital objects are symbol structures that express propositional content, and stand in layered encoding relationships. For example, an RDF description may be serialized as either XML or N3, and those expressions in turn may be encoded as either UTF-8 or UTF-16 sequences. Defining this encoding stack reveals distinctions necessary for a precise account of identity and equivalence

  13. Modified Equivalent Circuit for Organic Solar Cells

    Hossain, Nazmul

    In this work a newly fabricated organic solar cell based on a composite of fullerene derivative [6,6]-phenyl-C61 butyric acid methyl ester (PCBM) and regioregular poly (3-hexylthiophene) (P3HT) with an added interfacial layer of AgOx in between the PEDOT:PSS layer and the ITO layer is investigated. Previous equivalent circuit models are discussed and an equivalent circuit model is proposed for the fabricated device. Incorporation of the AgOx interfacial layer shows an increase in fill factor (by 33%) and power conversion efficiency (by 28%). Moreover proper correlation has been achieved between the experimental and simulated I-V plots. The simulation shows that device characteristics can be explained with accuracy by the proposed model.

  14. On the equivalence of GPD representations

    Müller, Dieter

    2016-01-01

    Phenomenological representations of generalized parton distributions (GPDs) implementing the non-trivial field theoretical requirements are employed in the present day strategies for extracting of hadron structure information encoded in GPDs from the observables of hard exclusive reactions. Showing out the equivalence of various GPD representations can help to get more insight into GPD properties and allow to build up flexible GPD models capable of satisfactory description of the whole set of available experimental data. We review the mathematical aspects of establishing equivalence between the the double partial wave expansion of GPDs in the conformal partial waves and in the $t$-channel ${\\rm SO}(3)$ partial waves and the double distribution representation of GPDs.

  15. Are All Wrong FCI Answers Equivalent?

    Dedic, Helena; Rosenfield, Steven; Lasry, Nathaniel

    2010-10-01

    The Force Concept Inventory (FCI) has been efficiently used to assess conceptual learning in mechanics. Each FCI question has one Newtonian answer and four wrong answers (distracters). Researchers and practitioners most frequently use measures of total score to assess learning. Yet, are all wrong answers equivalent? We conducted Latent Markov Chain Modeling (LMCM) analyses of all choices (right and wrong) on a subset of four FCI questions. LMCM assesses whether there are groups of students sharing similar patterns of responses. We infer that students sharing similar patterns also share similar reasoning. Our results show seven reasoning-groups. LMCM also computes probabilities of transition from one reasoning-group to another after instruction. Examining transitions between groups, we note a clear hierarchy. Groups at the top of the hierarchy are comprised of students that use Newtonian thinking more consistently but also choose certain wrong answers more frequently; suggesting that not all wrong answers are equivalent.

  16. Orbit equivalent substitution dynamical systems and complexity

    Bezuglyi, S

    2012-01-01

    For any primitive proper substitution \\sigma, we give explicit constructions of countably many pairwise non-isomorphic substitution dynamical systems {(X_{\\zeta_n}, T_{\\zeta_n})}_{n=1}^{\\infty} such that they all are (strong) orbit equivalent to (X_{\\sigma}, T_{\\sigma}). We show that the complexity of the substitution dynamical systems {(X_{\\zeta_n}, T_{\\zeta_n})} is essentially different that prevents them from being isomorphic. Given a primitive (not necessarily proper) substitution \\tau, we find a stationary simple properly ordered Bratteli diagram with the least possible number of vertices such that the corresponding Bratteli-Vershik system is orbit equivalent to (X_{\\tau}, T_{\\tau}).

  17. Equivalent dynamic model of DEMES rotary joint

    Zhao, Jianwen; Wang, Shu; Xing, Zhiguang; McCoul, David; Niu, Junyang; Huang, Bo; Liu, Liwu; Leng, Jinsong

    2016-07-01

    The dielectric elastomer minimum energy structure (DEMES) can realize large angular deformations by a small voltage-induced strain of the dielectric elastomer (DE), so it is a suitable candidate to make a rotary joint for a soft robot. Dynamic analysis is necessary for some applications, but the dynamic response of DEMESs is difficult to model because of the complicated morphology and viscoelasticity of the DE film. In this paper, a method composed of theoretical analysis and experimental measurement is presented to model the dynamic response of a DEMES rotary joint under an alternating voltage. Based on measurements of equivalent driving force and damping of the DEMES, the model can be derived. Some experiments were carried out to validate the equivalent dynamic model. The maximum angle error between model and experiment is greater than ten degrees, but it is acceptable to predict angular velocity of the DEMES, therefore, it can be applied in feedforward–feedback compound control.

  18. Galilean Equivalence for Galactic Dark Matter

    Kesden, M; Kesden, Michael; Kamionkowski, Marc

    2006-01-01

    Satellite galaxies of the Milky Way experience a tidal disruption as they orbit in the Milky Way's dark halo. While the bound core of the satellite remains dominated by dark matter, the tidally disrupted stars behave like purely baryonic tracers of the Milky Way's potential well. If dark matter experiences a stronger self attraction than visible matter, stars will preferentially gain rather than lose energy during tidal disruption. This leads to a relative enhancement in the trailing as compared to the leading tidal stream. We show that the absence of a strong asymmetry in the surface brightness of the leading and trailing tidal streams already constrains the equivalence of acceleration of dark matter and baryons in a gravitational field to less than ten percent--thus ruling out a recently proposed mechanism to clear dwarf galaxies from voids. Future observations should be sensitive at the percent level to departures from the equivalence of dark matter and baryons.

  19. Scaling Laws for Hydrodynamically Equivalent Implosions

    Murakami, Masakatsu

    2001-10-01

    The EPOC (equivalent physics of confinement) scenario for the proof of principle of high gain inertial confinement fusion is presented, where the key concept "hydrodynamically equivalent implosions" plays a crucial role. Scaling laws on the target and confinement parameters are derived by applying the Lie group analysis to the PDE (partially differential equations) chain of the hydrodynamic system. It turns out that the conventional scaling law based on adiabatic approximation significantly differs from one which takes such energy transport effect as electron heat conduction into account. Confinement plasma parameters of the hot spot such as the central temperature and the areal mass density at peak compression are obtained with a self-similar solution for spherical implosions.

  20. Probing Quantum Violations of the Equivalence Principle

    Adunas, G Z; Ahluwalia, D V

    2001-01-01

    The joint realm of quantum mechanics and the general-relativistic description of gravitation is becoming increasingly accessible to terrestrial experiments and observations. In this essay we study the emerging indications of the violation of equivalence principle (VEP). While the solar neutrino anomaly may find its natural explanation in a VEP, the statistically significant discrepancy observed in the gravitationally induced phases of neutron interferometry seems to be the first indication of a VEP. However, such a view would seem immediately challenged by the atomic interferometry results. The latter experiments see no indications of VEP, in apparent contradiction to the neutron interferometry results. Here we present arguments that support the view that these, and related torsion pendulum experiments, probe different aspects of gravity; and that current experimental techniques, when coupled to the solar-neutrino data, may be able to explore quantum mechanically induced violations of the equivalence principl...

  1. Equivalent functions for the Fresnel integral.

    Umul, Yusuf

    2005-10-17

    Fresnel integral is modeled with three equivalent functions. The first function is derived by considering the sum of the first term of the Fresnel integral's asymptotic expansion {F(x)} and an exponential function which approaches to infinity at the zero of the Fresnel function's argument and has the properties of a unit step function. The second one is the sum of a unit step function and the transition function defined for the simplified uniform theory of diffraction. The third function considers directly eliminating the infinity coming from F(x). The amplitude and the phase of Fresnel integral and its equivalent functions are compared numerically. The result is applied to the modified theory of physical optics solution of the diffraction of edge waves from a half plane problem. PMID:19498877

  2. Thevenin Equivalent Method for Dynamic Contingency Assessment

    Møller, Jakob Glarbo; Jóhannsson, Hjörtur; Østergaard, Jacob

    2015-01-01

    A method that exploits Thevenin equivalent representation for obtaining post-contingency steady-state nodal voltages is integrated with a method of detecting post-contingency aperiodic small-signal instability. The task of integrating stability assessment with contingency assessment is challenged...... by the cases of unstable post-contingency conditions. For unstable postcontingency conditions there exists no credible steady-state which can be used for basis of a stability assessment. This paper demonstrates how Thevenin Equivalent methods can be applied in algebraic representation of such...... bifurcation points which may be used in assessment of post-contingency aperiodic small-signal stability. The assessment method is introduced with a numeric example....

  3. Equivalency of two-dimensional algebras

    Santos, Gildemar Carneiro dos; Pomponet Filho, Balbino Jose S. [Universidade Federal da Bahia (UFBA), BA (Brazil). Inst. de Fisica

    2011-07-01

    Full text: Let us consider a vector z = xi + yj over the field of real numbers, whose basis (i,j) satisfy a given algebra. Any property of this algebra will be reflected in any function of z, so we can state that the knowledge of the properties of an algebra leads to more general conclusions than the knowledge of the properties of a function. However structural properties of an algebra do not change when this algebra suffers a linear transformation, though the structural constants defining this algebra do change. We say that two algebras are equivalent to each other whenever they are related by a linear transformation. In this case, we have found that some relations between the structural constants are sufficient to recognize whether or not an algebra is equivalent to another. In spite that the basis transform linearly, the structural constants change like a third order tensor, but some combinations of these tensors result in a linear transformation, allowing to write the entries of the transformation matrix as function of the structural constants. Eventually, a systematic way to find the transformation matrix between these equivalent algebras is obtained. In this sense, we have performed the thorough classification of associative commutative two-dimensional algebras, and find that even non-division algebra may be helpful in solving non-linear dynamic systems. The Mandelbrot set was used to have a pictorial view of each algebra, since equivalent algebras result in the same pattern. Presently we have succeeded in classifying some non-associative two-dimensional algebras, a task more difficult than for associative one. (author)

  4. Extended equivalent dipole model for radiated emissions

    Obiekezie, Chijioke S.

    2016-01-01

    This work is on the characterisation of radiated fields from electronic devices. An equivalent dipole approach is used. Previous work showed that this was an effective approach for single layer printed circuit boards where an infinite ground plane can be assumed. In this work, this approach is extended for the characterisation of more complex circuit boards or electronic systems. For complex electronic radiators with finite ground planes, the main challenge is characterising field diffract...

  5. Capacitors with low equivalent series resistance

    Fleig, Patrick Franz (Inventor); Lakeman, Charles D. E. (Inventor); Fuge, Mark (Inventor)

    2011-01-01

    An electric double layer capacitor (EDLC) in a coin or button cell configuration having low equivalent series resistance (ESR). The capacitor comprises mesh or other porous metal that is attached via conducting adhesive to one or both the current collectors. The mesh is embedded into the surface of the adjacent electrode, thereby reducing the interfacial resistance between the electrode and the current collector, thus reducing the ESR of the capacitor.

  6. The Otto-engine-equivalent vehicle concept

    Dowdy, M. W.; Couch, M. D.

    1978-01-01

    A vehicle comparison methodology based on the Otto-Engine Equivalent (OEE) vehicle concept is described. As an illustration of this methodology, the concept is used to make projections of the fuel economy potential of passenger cars using various alternative power systems. Sensitivities of OEE vehicle results to assumptions made in the calculational procedure are discussed. Factors considered include engine torque boundary, rear axle ratio, performance criteria, engine transient response, and transmission shift logic.

  7. Equivalence of polynomial conjectures in additive combinatorics

    Lovett, Shachar

    2010-01-01

    We study two conjectures in additive combinatorics. The first is the polynomial Freiman-Ruzsa conjecture, which relates to the structure of sets with small doubling. The second is the inverse Gowers conjecture for $U^3$, which relates to functions which locally look like quadratics. In both cases a weak form, with exponential decay of parameters is known, and a strong form with only a polynomial loss of parameters is conjectured. Our main result is that the two conjectures are in fact equivalent.

  8. Adaptive passive equivalence of uncertain Lü system

    Qi Dong-Lian

    2006-01-01

    An adaptive passive strategy for controlling uncertain Lü system is proposed. Since the uncertain Lü system is minimum phase and the uncertain parameters are from a bounded compact set, the essential conditions are studied by which uncertain Lü system could be equivalent to a passive system, and the adaptive control law is given. Using passive theory, the uncertain Lü system could be globally asymptotically stabilized at different equilibria by the smooth state feedback.

  9. Quantum Mechanics from an Equivalence Principle

    Faraggi, A E; Faraggi, Alon E.; Matone, Marco

    1999-01-01

    We show that requiring diffeomorphic equivalence for one-dimensional stationary states implies that the reduced action $\\S_0$ satisfies the quantum Hamilton-Jacobi equation with the Planck constant playing the role of a covariantizing parameter. The construction shows the existence of a fundamental initial condition which is strictly related to the Möbius symmetry of the Legendre transform and to its involutive character. The universal nature of the initial condition implies the Schrödinger equation in any dimension.

  10. Electromagnetic Boundaries with PEC/PMC Equivalence

    Lindell, Ismo V

    2016-01-01

    The most general electromagnetic boundary, defined by linear and local boundary conditions, is defined in terms of conditions which can be called generalized impedance boundary conditions. Requiring that the boundary be equivalent to PEC and PMC boundaries for its two eigen-plane waves, which property is known to exist for many of its special cases, it is shown that the recently introduced Generalized Soft-and-Hard/DB (GSHDB) boundary is the most general boundary satisfying this property.

  11. Quantum mechanics from an equivalence principle

    The authors show that requiring diffeomorphic equivalence for one-dimensional stationary states implies that the reduced action S0 satisfies the quantum Hamilton-Jacobi equation with the Planck constant playing the role of a covariantizing parameter. The construction shows the existence of a fundamental initial condition which is strictly related to the Moebius symmetry of the Legendre transform and to its involutive character. The universal nature of the initial condition implies the Schroedinger equation in any dimension

  12. Equivalence Scales for the Former West Germany

    Charlier, E.

    1997-01-01

    Equivalence scales provide answers to questions like how much a household with four children needs to spend compared to a household with two children or how much a childless couple needs to spend compared to a single person household to attain the same welfare level. These are important questions for child allowances, social benefits and to assess the cost of children over the life-cycle for example. The latter is also interesting from a theoretical point of view, especially if future events ...

  13. Cryogenic test of the equivalence principle

    The weak equivalence principle is the hypothesis that the ratio of internal and passive gravitational mass is the same for all bodies. A greatly improved test of this principle is possible in an orbiting satellite. The most promising experiments for an orbital test are adaptations of the Galilean free-fall experiment and the Eotvos balance. Sensitivity to gravity gradient noise, both from the earth and from the spacecraft, defines a limit to the sensitivity in each case. This limit is generally much worse for an Eotvos balance than for a properly designed free-fall experiment. The difference is related to the difficulty of making a balance sufficiently isoinertial. Cryogenic technology is desirable to take full advantage of the potential sensitivity, but tides in the liquid helium refrigerant may produce a gravity gradient that seriously degrades the ultimate sensitivity. The Eotvos balance appears to have a limiting sensitivity to relative difference of rate of fall of about 2 x 10-14 in orbit. The free-fall experiment is limited by helium tide to about 10-15; if the tide can be controlled or eliminated the limit may approach 10-18. Other limitations to equivalence principle experiments are discussed. An experimental test of some of the concepts involved in the orbital free-fall experiment is continuing. The experiment consists in comparing the motions of test masses levitated in a superconducting magnetic bearing, and is itself a sensitive test of the equivalence principle. At present the levitation magnets, position monitors and control coils have been tested and major noise sources identified. A measurement of the equivalence principle is postponed pending development of a system for digitizing data. The experiment and preliminary results are described

  14. Equivalence of the Einstein and Jordan frames

    Postma, Marieke; Volponi, Marco

    2014-01-01

    No experiment can measure an absolute scale: every dimensionfull quantity has to be compared to some fixed unit scale in order to be measured, and thus only dimensionless quantities are really physical. The Einstein and Jordan frame are related by a conformal transformation of the metric, which amounts to rescaling all length scales. Since the absolute scale cannot be measured, both frames describe the same physics, and are equivalent. In this article we make this explicit by rewriting the ac...

  15. Quantum mechanics from an equivalence principle

    Faraggi, A.E. [Univ. of Florida, Gainesville, FL (United States). Inst. for Fundamental Theory; Matone, M. [Univ. of Padova (Italy)

    1997-05-15

    The authors show that requiring diffeomorphic equivalence for one-dimensional stationary states implies that the reduced action S{sub 0} satisfies the quantum Hamilton-Jacobi equation with the Planck constant playing the role of a covariantizing parameter. The construction shows the existence of a fundamental initial condition which is strictly related to the Moebius symmetry of the Legendre transform and to its involutive character. The universal nature of the initial condition implies the Schroedinger equation in any dimension.

  16. On the equivalence of GPD representations

    Müller, Dieter; Semenov-Tian-Shansky, Kirill

    2016-01-01

    Phenomenological representations of generalized parton distributions (GPDs) implementing the non-trivial field theoretical requirements are employed in the present day strategies for extracting of hadron structure information encoded in GPDs from the observables of hard exclusive reactions. Showing out the equivalence of various GPD representations can help to get more insight into GPD properties and allow to build up flexible GPD models capable of satisfactory description of the whole set of...

  17. Higgs Physics and the Equivalence Theorem

    Riesselmann, Kurt

    1995-01-01

    The equivalence theorem is an extremely useful tool to calculate heavy Higgs {\\it and} top-quark effects for processes that have center-of-mass-energies (much) larger than the $W$ boson mass. After an explanation of the renormalization procedures involved, the results for one- and two-loop radiative corrections to the fermionic Higgs decay, $H\\rightarrow f\\bar f$, are given and discussed. Finally, the renormalization scheme dependence is examined, and the reliability of the perturbative serie...

  18. The Equivalence Theorem and Effective Lagrangians

    Grosse-Knetter, Carsten; Kuss, Ingolf

    1994-01-01

    We point out that the equivalence theorem, which relates the amplitude for a process with external longitudinally polarized vector bosons to the amplitude in which the longitudinal vector bosons are replaced by the corresponding pseudo-Goldstone bosons, is not valid for effective Lagrangians. However, a more general formulation of this theorem also holds for effective interactions. The generalized theorem can be utilized to determine the high-energy behaviour of scattering processes just by p...

  19. Dibaryon Mass and Width Calculation with Tensor Interaction

    PANG Hou-Rong; PING Jia-Lun; CHEN Ling-Zhi; WANG Fan

    2004-01-01

    @@ The effect of tensor interaction due to gluon and Goldstone boson exchange on the dibaryon mass and decay width has been studied in the framework of the quark delocalization and colour screening model. The effective S-D wave transition interactions induced by gluon and Goldstone boson exchanges decrease quickly with the increasing channel strangeness, and there is no six-quark state in the light flavour world, which can become a bound one by the help of these tensor interactions, except for the deuteron. The K and η meson exchange effect has been shown to be negligible after a short-range truncation in this model approach. The partial D-wave decay widths, from the NΩ state to the A final states of spins 0 and 1, are 20. 7keV and 63.1 kev respectively. This is a very narrow dibaryon resonance, that might be detected in the relativistic heavy ion reaction by the existing RHIC detectors through the reconstruction of the A vertex mass and by the future COMPAS detector at CERNand the FAIR project in Germany.

  20. Constraining the mass and width of the $N^*(1685)$ resonance

    Mart, T

    2013-01-01

    We have examined the existence of the $N^*(1685)$ resonance, which is recently listed by the Particle Data Group as a one-star nucleon resonance, by using a covariant isobar model for kaon photoproduction and assuming that the resonance has $J^p=1/2^+$, in accordance with our previous finding. After the inclusion of this resonance the changes in the total $\\chi^2$ show two clear minima at $M_{N^*}=1650$ and 1696 MeV, which correspond to two different resonance states. The former corresponds to the narrow nucleon resonance found in our previous investigation, whereas the latter corresponds to a new resonance found as we increase the resonance width. From the latter we derive the mass and width relation of the $N^*(1685)$ resonance. We observe that the properties of both the $N^*(1685)$ and $N^*(1710)P_{11}$ resonances are strongly correlated. Although the best fit of the present work yields $M_{N^*}=1696$ MeV and $\\Gamma_{N^*}=76$ MeV, the apparently small $N^*(1710)P_{11}$ coupling constant to the $K^+\\Lambda...

  1. Thumbnail with Integrated Blur Based on Edge Width Analysis

    Boon Tatt Koik

    2016-01-01

    Full Text Available Thumbnail image is widely used in electronic devices to help the user to scan through original high resolution images. Hence, it is essential to represent the thumbnail image correspondingly to the original image. A blur image should not appear to be a clear image in thumbnail form, where this situation might mislead the perceptual analysis of user. The main purpose of this research work is to develop a downsampling algorithm to create a thumbnail image which includes blur information. The proposed method has three stages involved to obtain the proposed output thumbnail, which are preliminary processes, blur detection, and lastly image downsampling. For preliminary processes, Sobel first-order derivatives, gradient magnitude, and gradient orientation are determined. In blur detection stage, local maximum, local minimum, and gradient orientation are ultilized to calculate the edge width. The thumbnail image with blur information is generated using the average edge width map as a weightage to integrate blur information. This proposed method has achieved satisfying results and has high potential to be applied as one of the thumbnail generation options for photo viewing.

  2. Is biologic width of anterior and posterior teeth similar?

    Amir Alireza Rasouli Ghahroudi

    2014-09-01

    Full Text Available The biologic width (BW includes attached epithelial cells and connective tissue attachment complex being very important in the periodontal health during prosthetic treatments as invading this zone can cause bone resorption and gingival recession. The present study investigated biologic width values in the normal periodontium in anterior and posterior teeth. 30 patients that referred from restorative department to periodontics department of Tehran University of medical sciences who need crown lengthening procedure on their teeth with no history of orthodontic, prosthodontic and periodontal treatment were randomly enrolled in this cross-sectional trial. Sulcus depths (SD as well as the distance between free gingival margin and the bone crest (FB of anterior and posterior teeth were measured by UNC-15 probe and compared. periodontium thickness was also assessed. The data were subjected to Student t test. Mean BW in the 43 anterior and 47 posterior teeth was measured and not significantly different (1.4651±0.39 mm vs. 1.6312±0.49 mm was observed; however, BW was significantly more in the teeth with thick periodontium compared to those with thin periodontium (1.703±0.5 vs. 1.408±0.35; P=0.002. BW not only is different in individuals but also could be dissimilar in different teeth and should be calculated independently prior to restorative treatments.

  3. Is biologic width of anterior and posterior teeth similar?

    Rasouli Ghahroudi, Amir Alireza; Khorsand, Afshin; Yaghobee, Siamak; Haghighati, Farideh

    2014-01-01

    The biologic width (BW) includes attached epithelial cells and connective tissue attachment complex being very important in the periodontal health during prosthetic treatments as invading this zone can cause bone resorption and gingival recession. The present study investigated biologic width values in the normal periodontium in anterior and posterior teeth. 30 patients that referred from restorative department to periodontics department of Tehran University of medical sciences who need crown lengthening procedure on their teeth with no history of orthodontic, prosthodontic and periodontal treatment were randomly enrolled in this cross-sectional trial. Sulcus depths (SD) as well as the distance between free gingival margin and the bone crest (FB) of anterior and posterior teeth were measured by UNC-15 probe and compared. periodontium thickness was also assessed. The data were subjected to Student t test. Mean BW in the 43 anterior and 47 posterior teeth was measured and not significantly different (1.4651±0.39 mm vs. 1.6312±0.49 mm) was observed; however, BW was significantly more in the teeth with thick periodontium compared to those with thin periodontium (1.703±0.5 vs. 1.408±0.35; P=0.002). BW not only is different in individuals but also could be dissimilar in different teeth and should be calculated independently prior to restorative treatments. PMID:25325207

  4. Potential dominance of oscillating crescent waves in finite width tanks

    Fuhrman, David R.; Madsen, Per A.

    2005-01-01

    Recently, it has been proposed that the emergence of previously observed oscillating crescent water wave patterns, created by class II (three-dimensional) instabilities which are in principle not dominant, could in fact be explained as an artifact of a finite width tank, combined with a suppressi...... dominant is surprisingly large, particularly for low to moderate wave steepness. This is an important realization for both experimentalists and numerical modelers currently studying these phenomena......Recently, it has been proposed that the emergence of previously observed oscillating crescent water wave patterns, created by class II (three-dimensional) instabilities which are in principle not dominant, could in fact be explained as an artifact of a finite width tank, combined with a suppression...... of the class I (Benjamin-Feir) instability. Within this context, we investigate quantitatively the dominance of class II deep water wave instabilities for particular transversal wavenumbers, and it is shown that the regions where non-phase-locked (oscillating) crescent wave patterns are locally...

  5. Determination of the width of the top quark

    Abazov, Victor Mukhamedovich; /Dubna, JINR; Abbott, Braden Keim; /Oklahoma U.; Abolins, Maris A.; /Michigan State 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.; Alves, Gilvan Augusto; /Rio de Janeiro, CBPF /Nijmegen U.

    2010-09-01

    We extract the total width of the top quark, {Lambda}{sub t}, from the partial decay width {Lambda}(t {yields} Wb) measured using the t-channel cross section for single top quark production and from the branching fraction B(t {yields} Wb) measured in t{bar t} events using up to 2.3 fb{sup -1} of integrated luminosity collected by the D0 Collaboration at the Tevatron p{bar p} Collider. The result is {Lambda}{sub t} = 1.99{sub -0.55}{sup +0.69} GeV, which translates to a top-quark lifetime of {tau}{sub t} = (3.3{sub -0.9}{sup +1.3}) x 10{sup -25} s. Assuming a high mass fourth generation b{prime} quark and unitarity of the four-generation quark-mixing matrix, we set the first upper limit on |V{sub tb{prime}}| < 0.63 at 95% C.L.

  6. Combining LEP and LHC to bound the Higgs Width

    Englert, Christoph; Spannowsky, Michael

    2016-01-01

    The correlation of on- and off-shell Higgs boson production at the LHC in $gg \\to h^* \\to ZZ$ to bound the Higgs width, under specific model-dependent assumptions, has recently received a lot of attention. As off-shell cross section measurements in this channel suffer from a small signal yield, large backgrounds, and theoretical uncertainties, we propose an alternative complementary constraint which is only possible through the combination of LEP and LHC measurements. Previous precision electroweak measurements at LEP allow for the determination of indirect constraints on Higgs couplings to vector bosons by considering one-loop processes involving virtual Higgs exchange. As the Higgs is off-shell in these diagrams we venture that LEP can be interpreted as an off-shell `Higgs Factory'. By combining these LEP constraints with current LHC 8 TeV Higgs measurements a stronger limit on the Higgs width can be achieved than with LHC data alone for models with rescaled Higgs couplings. Looking to the future, avoiding ...

  7. Superstring field theory equivalence: Ramond sector

    Kroyter, Michael

    2009-01-01

    We extend the classical equivalence between the cubic and the non-polynomial open superstring field theories to the Ramond sector. To that end we find mappings between the string fields (NS and Ramond, including Chan-Paton factors and the various GSO sectors) of the two theories that send solutions to solutions in a way that respects the gauge symmetries in both sides and keeps the action of the solutions invariant. The perturbative spectrum around equivalent solutions is also isomorphic. We show that the gauge symmetry of the Ramond sector of the modified cubic theory suffers from collisions of picture changing operators. Our mapping works at the level of the linearized gauge transformation, which is well-defined. Nonetheless, the familiar form of the cubic theory is inconsistent and should be modified. Hence, at this level, our equivalence is only formal, since it relates a consistent theory to an inconsistent one. At the non-polynomial theory the Ramond sector is described using two constrained string fiel...

  8. Dioxin equivalency: Challenge to dose extrapolation

    Brown, J.F. Jr.; Silkworth, J.B. [GE Corporate Research and Development, Schenectady, NY (United States)

    1995-12-31

    Extensive research has shown that all biological effects of dioxin-like agents are mediated via a single biochemical target, the Ah receptor (AhR), and that the relative biologic potencies of such agents in any given system, coupled with their exposure levels, may be described in terms of toxic equivalents (TEQ). It has also shown that the TEQ sources include not only chlorinated species such as the dioxins (PCDDs), PCDFs, and coplanar PCBs, but also non-chlorinated substances such as the PAHs of wood smoke, the AhR agonists of cooked meat, and the indolocarbazol (ICZ) derived from cruciferous vegetables. Humans have probably had elevated exposures to these non-chlorinated TEQ sources ever since the discoveries of fire, cooking, and the culinary use of Brassica spp. Recent assays of CYP1A2 induction show that these ``natural`` or ``traditional`` AhR agonists are contributing 50--100 times as much to average human TEQ exposures as do the chlorinated xenobiotics. Currently, the safe doses of the xenobiotic TEQ sources are estimated from their NOAELs and large extrapolation factors, derived from arbitrary mathematical models, whereas the NOAELs themselves are regarded as the safe doses for the TEQs of traditional dietary components. Available scientific data can neither support nor refute either approach to assessing the health risk of an individual chemical substance. However, if two substances be toxicologically equivalent, then their TEQ-adjusted health risks must also be equivalent, and the same dose extrapolation procedure should be used for both.

  9. TNT equivalency of M10 propellant

    Mcintyre, F. L.; Price, P.

    1978-01-01

    Peak, side-on blast overpressure and scaled, positive impulse have been measured for M10 single-perforated propellant, web size 0.018 inches, using configurations that simulate the handling of bulk material during processing and shipment. Quantities of 11.34, 22.7, 45.4, and 65.8 kg were tested in orthorhombic shipping containers and fiberboard boxes. High explosive equivalency values for each test series were obtained as a function of scaled distance by comparison to known pressure, arrival time and impulse characteristics for hemispherical TNT surface bursts. The equivalencies were found to depend significantly on scaled distance, with higher values of 150-100 percent (pressure) and 350-125 percent (positive impulse) for the extremes within the range from 1.19 to 3.57 m/cube root of kg. Equivalencies as low as 60-140 percent (pressure) and 30-75 percent (positive impulse) were obtained in the range of 7.14 to 15.8 m/cube root of kg. Within experimental error, both peak pressure and positive impulse scaled as a function of charge weight for all quantities tested in the orthorhombic configuration.

  10. Water equivalence of polymer gel dosimeters

    Sellakumar, P. [Bangalore Institute of Oncology, 44-45/2, II Cross, RRMR Extension, Bangalore-560 027 (India)]. E-mail: psellakumar@rediffmail.com; James Jebaseelan Samuel, E. [School of Science and Humanities, Vellore Institute of Technology, Vellore-632 014 (India); Supe, Sanjay S. [Kidwai Memorial Institute of Oncology, Hosur Road, Bangalore-560 027 (India)

    2007-07-15

    To evaluate the water equivalence and radiation transport properties of polymer gel dosimeters over the wide range of photon and electron energies 14 different types of polymer gels were considered. Their water equivalence was evaluated in terms of effective atomic number (Z{sub eff}), electron density ({rho}{sub e}), photon mass attenuation coefficient ({mu}/{rho}), photon mass energy absorption coefficient ({mu}{sub en}/{rho}) and total stopping power (S/{rho}){sub tot} of electrons using the XCOM and the ESTAR database. The study showed that the effective atomic number of polymer gels were very close (<1%) to that of water except PAGAT, MAGAT and NIPAM which had the variation of 3%, 2% and 3%, respectively. The value of {mu}/{rho} and {mu}{sub en}/{rho} for all polymer gels were in close agreement (<1%) with that of water beyond 80keV. The value of (S/{rho}){sub tot} of electrons in polymer gel dosimeters were within 1% agreement with that of water. From the study we conclude that at lower energy (<80keV) the polymer gel dosimeters cannot be considered water equivalent and study has to be carried out before using the polymer gel for clinical application.

  11. Equivalent models of wind farms by using aggregated wind turbines and equivalent winds

    Fernandez, L.M.; Garcia, C.A.; Saenz, J.R. [Department of Electrical Engineering, EPS Algeciras, University of Cadiz, Avda. Ramon Puyol, s/n. 11202 Algeciras, Cadiz (Spain); Jurado, F. [Department of Electrical Engineering, EPS Linares, University of Jaen, C/ Alfonso X, n 28. 23700 Linares, Jaen (Spain)

    2009-03-15

    As a result of the increasing wind farms penetration on power systems, the wind farms begin to influence power system, and therefore the modeling of wind farms has become an interesting research topic. In this paper, new equivalent models of wind farms equipped with wind turbines based on squirrel-cage induction generators and doubly-fed induction generators are proposed to represent the collective behavior on large power systems simulations, instead of using a complete model of wind farms where all the wind turbines are modeled. The models proposed here are based on aggregating wind turbines into an equivalent wind turbine which receives an equivalent wind of the ones incident on the aggregated wind turbines. The equivalent wind turbine presents re-scaled power capacity and the same complete model as the individual wind turbines, which supposes the main feature of the present equivalent models. Two equivalent winds are evaluated in this work: (1) the average wind from the ones incident on the aggregated wind turbines with similar winds, and (2) an equivalent incoming wind derived from the power curve and the wind incident on each wind turbine. The effectiveness of the equivalent models to represent the collective response of the wind farm at the point of common coupling to grid is demonstrated by comparison with the wind farm response obtained from the detailed model during power system dynamic simulations, such as wind fluctuations and a grid disturbance. The present models can be used for grid integration studies of large power system with an important reduction of the model order and the computation time. (author)

  12. Equivalent models of wind farms by using aggregated wind turbines and equivalent winds

    As a result of the increasing wind farms penetration on power systems, the wind farms begin to influence power system, and therefore the modeling of wind farms has become an interesting research topic. In this paper, new equivalent models of wind farms equipped with wind turbines based on squirrel-cage induction generators and doubly-fed induction generators are proposed to represent the collective behavior on large power systems simulations, instead of using a complete model of wind farms where all the wind turbines are modeled. The models proposed here are based on aggregating wind turbines into an equivalent wind turbine which receives an equivalent wind of the ones incident on the aggregated wind turbines. The equivalent wind turbine presents re-scaled power capacity and the same complete model as the individual wind turbines, which supposes the main feature of the present equivalent models. Two equivalent winds are evaluated in this work: (1) the average wind from the ones incident on the aggregated wind turbines with similar winds, and (2) an equivalent incoming wind derived from the power curve and the wind incident on each wind turbine. The effectiveness of the equivalent models to represent the collective response of the wind farm at the point of common coupling to grid is demonstrated by comparison with the wind farm response obtained from the detailed model during power system dynamic simulations, such as wind fluctuations and a grid disturbance. The present models can be used for grid integration studies of large power system with an important reduction of the model order and the computation time

  13. Theoretical analysis of surface stress for a microcantilever with varying widths

    A theoretical model of surface stress is developed in this paper for a microcantilever with varying widths, and a method for calculating the surface stress via static deflection, slope angle or radius at curvature of the cantilever beam is presented. This model assumes that surface stresses are uniformly distributed on one surface of the cantilever beam. Based on this stressor model and using the small deformation Euler-Bernoulli beam theory, a fourth-order ordinary differential governing equation with varying coefficients or an equivalent second-order integro-differential equation is derived. A simple approach is then proposed to determine the solution of the resulting equation, and a closed-form approximate solution with high accuracy can be obtained. For rectangular and V-shaped microfabricated cantilevers, the dependences of transverse deflection, slope and curvature of the beam on the surface stresses are given explicitly. The obtained results indicate that the zeroth order approximation of the stressor model reduces to the end force model with a linear curvature for a rectangular cantilever. For larger surface stresses, the curvature exhibits a non-linear behaviour. The predictions through the stressor model give higher accuracy than those from the end moment and end force models and satisfactorily agree with experimental data. The derived closed-form solution can serve as a theoretical benchmark for verifying numerically obtained results for microcantilevers as atomic force microscopy and micromechanical sensors

  14. Approximate trace and singleton failures equivalences for transition systems

    Chao Wang; Jinzhao Wu; Hongyan Tan

    2015-01-01

    Established system equivalences for transition systems, such as trace equivalence and failures equivalence, require the ob-servations to be exactly identical. However, an accurate measure-ment is impossible when interacting with the physical world, hence exact equivalence is restrictive and not robust. Using Baire met-ric, a generalized framework of transition system approximation is proposed by developing the notions of approximate language equivalence and approximate singleton failures (SF) equivalence. The framework takes the traditional exact equivalence as a special case. The approximate language equivalence is coarser than the approximate SF equivalence, just like the hierarchy of the exact ones. The main conclusion is that the two approximate equiva-lences satisfy the transitive property, consequently, they can be successively used in transition system approximation.

  15. Invariantly propagating dissolution fingers in finite-width systems

    Dutka, Filip; Szymczak, Piotr

    2016-04-01

    Dissolution fingers are formed in porous medium due to positive feedback between transport of reactant and chemical reactions [1-4]. We investigate two-dimensional semi-infinite systems, with constant width W in one direction. In numerical simulations we solve the Darcy flow problem combined with advection-dispersion-reaction equation for the solute transport to track the evolving shapes of the fingers and concentration of reactant in the system. We find the stationary, invariantly propagating finger shapes for different widths of the system, flow and reaction rates. Shape of the reaction front, turns out to be controlled by two dimensionless numbers - the (width-based) Péclet number PeW = vW/Dφ0 and Damköhler number DaW = ksW/v, where k is the reaction rate, s - specific reactive surface area, v - characteristic flow rate, D - diffusion coefficient of the solute, and φ0 - initial porosity of the rock matrix. Depending on PeW and DaW stationary shapes can be divided into seperate classes, e.g. parabolic-like and needle-like structures, which can be inferred from theoretical predictions. In addition we determine velocity of propagating fingers in time and concentration of reagent in the system. Our simulations are compared with natural forms (solution pipes). P. Ortoleva, J. Chadam, E. Merino, and A. Sen, Geochemical self-organization II: the reactive-infiltration instability, Am. J. Sci, 287, 1008-1040 (1987). M. L. Hoefner, and H. S. Fogler. Pore evolution and channel formation during flow and reaction in porous media, AIChE Journal 34, 45-54 (1988). C. E. Cohen, D. Ding, M. Quintard, and B. Bazin, From pore scale to wellbore scale: impact of geometry on wormhole growth in carbonate acidization, Chemical Engineering Science 63, 3088-3099 (2008). P. Szymczak and A. J. C. Ladd, Reactive-infiltration nstabilities in rocks. Part II: Dissolution of a porous matrix, J. Fluid Mech. 738, 591-630 (2014).

  16. Gaussian Radial and Kernel Networks with Varying and Fixed Widths

    Kůrková, Věra

    Vol. 2. Prague : Institute of Computer Science AS CR, 2013 - (van Emde Boas, P.; Groen, F.; Italiano, G.; Nawrocki, J.; Sack, H.), s. 95-102 ISBN 978-80-87136-15-7. [SOFSEM 2013. Conference on Current Trends in Theory and Practice of Computer Science /39./. Špindlerův Mlýn (CZ), 26.01.2013-31.01.2013] R&D Projects: GA ČR GAP202/11/1368 Institutional support: RVO:67985807 Keywords : Gaussian radial and kernel networks * functionally equivalent networks * universal approximators * stabilizers defined by Gaussian kernels Subject RIV: IN - Informatics, Computer Science

  17. Exotic vector charmonium and its leptonic decay width

    Chen, Ying; Gong, Ming; Gui, Long-Cheng; Liu, Zhaofeng

    2016-01-01

    We propose a novel type of interpolating field operators, which manifests the hybrid-like configuration that the charm quark-antiquark pair recoils against gluonic degrees of freedom. A heavy vector charmonium-like state with a mass of $4.33(2)\\,{\\rm GeV}$ is disentangled from the conventional charmonium states in the quenched approximation. This state has affinity for the hybrid-like operators but couples less to the relevant quark bilinear operator. We also try to extract its leptonic decay constant and give a tentative upper limit that it is less than one tenth of that of $J/\\psi$, which corresponds to a leptonic decay width about dozens of eV. The connection of this state with $X(4260)$ is also discussed.

  18. Width spreading and tests of wave packet molecular dynamics

    Complete text of publication follows. We examine three aspects of wave packet molecular dynamics (WPMD): wave packet spreading, the versatility of the isotropic Gaussian basis, and the interpretation of WPMD data. It is commonly known in the WPMD community that at large temperatures isotropic Gaussian wave packets have divergent widths. We quantify the unphysicality of this behavior by calculating radial distribution functions at many temperatures and densities, and compare to quantum statistical potential and path integral Monte Carlo results. We also make direct comparisons with a numerically exact time-dependent Schroedinger equation solver to determine deficiencies in the basis by studying a single quantum electron traveling through a static classical dense plasma. Another aspect is the validity of standard calculation methods. Central to these quantum computations are the ensemble explored by WPMD and its ergodic properties.

  19. Electron tunnelling through a quantifiable barrier of variable width

    Wyatt, A F G [School of Physics, University of Exeter, Exeter, EX4 4QL (United Kingdom); Bromberger, H; Klier, J; Leiderer, P; Zech, M [Faculty of Physics, University of Konstanz, Konstanz 78457 (Germany)], E-mail: a.f.g.wyatt@exeter.ac.uk

    2009-02-01

    This is the first study of electron tunnelling through a quantifiable barrier of adjustable width. We find quantitative agreement between the measured and calculated tunnelling probability with no adjustable constants. The tunnel barrier is a thin film of {sup 3}He on Cs{sub 1} which it wets. We excite photoelectrons which have to tunnel through the barrier to escape. The image potential must be included in calculating the barrier and hence the tunnelling current. This has been a debatable point until now. We confirm that an electron has a potential of 1.0 eV in liquid 3He for short times before a bubble forms. We show that the thickness of the {sup 3}He is given by thermodynamics for films of thickness at least down to 3 monolayers.

  20. Electron tunnelling through a quantifiable barrier of variable width

    Wyatt, A. F. G.; Bromberger, H.; Klier, J.; Leiderer, P.; Zech, M.

    2009-02-01

    This is the first study of electron tunnelling through a quantifiable barrier of adjustable width. We find quantitative agreement between the measured and calculated tunnelling probability with no adjustable constants. The tunnel barrier is a thin film of 3He on Cs1 which it wets. We excite photoelectrons which have to tunnel through the barrier to escape. The image potential must be included in calculating the barrier and hence the tunnelling current. This has been a debatable point until now. We confirm that an electron has a potential of 1.0 eV in liquid 3He for short times before a bubble forms. We show that the thickness of the 3He is given by thermodynamics for films of thickness at least down to 3 monolayers.