WorldWideScience
1

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2

H-alpha Equivalent Width Variations across the Face of a Microlensed K Giant in the Galactic Bulge  

CERN Document Server

We present VLT FORS1 spectroscopy that temporally resolves the second caustic crossing of the Bulge K giant stellar source of microlensing event EROS 2000-BLG-5, the first time this has been accomplished for several phases of a caustic transit. The ~1 angstrom H-alpha equivalent width of the source star increases slightly as the center of the star egresses the caustic and then plummets by 30% during the final limb crossing. These changes are not seen in contemporaneous spectra of control stars in the FORS1 slit, but are consistent with expectations from stellar atmosphere models as the caustic differentially magnifies different portions of the stellar face of the target. Observations such as these in a variety of stellar lines are equivalent to atmospheric tomography and are expected to provide a direct test of stellar models.

Albrow, M; Beaulieu, J P; Caldwell, J A R; Dominik, M; Greenhill, J; Hill, K; Kane, S; Martin, R; Menzies, J; Pollard, K R; Sackett, P D; Sahu, K C; Vermaak, P; Watson, R; Williams, A; Hauschildt, P H

2001-01-01

3

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

International Nuclear Information System (INIS)

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

4

ARES: Automatic Routine for line Equivalent widths in stellar Spectra  

Science.gov (United States)

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

Sousa, Sérgio G.

2012-05-01

5

PACCE: Perl Algorithm to Compute Continuum and Equivalent Widths  

OpenAIRE

We present Perl Algorithm to Compute continuum and Equivalent Widths (pacce). We describe the methods used in the computations and the requirements for its usage. We compare the measurements made with pacce and "manual" ones made using iraf splot task. These tests show that for SSP models the equivalent widths strengths are very similar (differences <0.2A) for both measurements. In real stellar spectra, the correlation between both values is still very good, but with differe...

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

2011-01-01

6

FUNDPAR: A Program for deriving Fundamental Parameters from Equivalent Widths  

CERN Document Server

We implemented a fortran code that determine fundamental parameters of solar type stars from a list of Fe line equivalent widths. The solution should verify 3 conditions in the standard method: ionization equilibrium, excitation equilibrium and independence between metallicity and equivalent widths. We added the condition that the input metallicity of the model atmosphere should be similar to the output metallicity derived with equivalent widths. Solar-scaled Kurucz model atmospheres with NEWODF opacities are calculated with an independent program. Parameter files control different details, such as the mixing-length parameter, the overshooting, the damping of the lines and the weight factors in the definition of the chi2 function. FUNDPAR derive the uncertainties following 2 methods: the criteria of Gonzalez & Vanture (1998) and the dispersion using the chi2 function. The code use the 2009 version of the MOOG program. The results derived with FUNDPAR are in agreement with previous determinations in the li...

Saffe, Carlos

2010-01-01

7

pacce: Perl algorithm to compute continuum and equivalent widths  

Science.gov (United States)

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

Riffel, Rogério; Borges Vale, Tibério

2011-08-01

8

Evidence of $H\\alpha$ periodicities in LS I+61303  

CERN Document Server

We present the results of analyzing H$\\alpha$ spectra of the radio emitting X-ray binary LS I+61303. For the first time, the same 26.5 d radio period is clearly detected in the H$\\alpha$ emission line. Moreover, the equivalent width and the peak separation of the H$\\alpha$ emission line seem also to vary over a time scale of 1600 days. This points towards the $\\sim4$ yr modulation, detected in the radio outburst amplitude, being probably a result of variations in the mass loss rate of the Be star and/or density variability in the circumstellar disk. In addition, the dependence of the peak separation from the equivalent width informs us that the LS I+61303 circumstellar disk is among the densest of Be-stars.

Zamanov, R K; Paredes, J M; Fabregat, J; Ribó, M; Tarasov, A E

1999-01-01

9

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

OpenAIRE

We present a new automatic code (ARES) for determining equivalent widths of the absorption lines present in stellar spectra. We also describe its use for determining fundamental spectroscopic stellar parameters. The code is written in C++ based on the standard method of determining EWs and is available for the community. The code automates the manual procedure that the users normally carry out when using interactive routines such as the splot routine implemented in IRAF. ...

Sousa, S. G.; Santos, N. C.; Israelian, G.; Mayor, M.; Monteiro, M. J. P. F. G.

2007-01-01

10

FUNDPAR: A program for Deriving Fundamental Parameters from Equivalent Widths  

Scientific Electronic Library Online (English)

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

C, Saffe.

2011-04-01

11

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

OpenAIRE

In the first two papers of this series the chemical composition of 20 extreme halo stars was discussed. The abundances of a number of elements were determined using model atmosphere analysis of equivalent widths. In this paper a tabulation of the equivalent width data is presented. A comparison of the measurements with the equivalent widths from different sources is used to assess the quality of the data.

Zhao, G.; Magain, Pierre

1990-01-01

12

The H alpha Galaxy Survey I. The galaxy sample, H alpha narrow-band observations and star formation parameters for 334 galaxies  

OpenAIRE

We discuss the selection and observations of a large sample of nearby galaxies, which we are using to quantify the star formation activity in the local Universe. The sample consists of 334 galaxies across all Hubble types from S0/a to Im and with recession velocities of between 0 and 3000 km/s. The basic data for each galaxy are narrow band H alpha plus [NII] and R-band imaging, from which we derive star formation rates, H alpha plus [NII] equivalent widths and surface brigh...

James, P. A.; Shane, N. S.; Beckman, J. E.; Cardwell, A.; Collins, C. A.; Etherton, J.; Jong, R. S.; Fathi, K.; Knapen, J. H.; Peletier, R. F.; Percival, S. M.; Pollacco, D. L.; Seigar, M. S.; Stedman, S.; Steele, I. A.

2003-01-01

13

Chromospheric Variability in SDSS M Dwarfs. II. Short-Timescale H-alpha Variability  

CERN Document Server

[Abridged] We present the first comprehensive study of short-timescale chromospheric H-alpha variability in M dwarfs using the individual 15 min spectroscopic exposures for 52,392 objects from the Sloan Digital Sky Survey. Our sample contains about 10^3-10^4 objects per spectral type bin in the range M0-M9, with a total of about 206,000 spectra and a typical number of 3 exposures per object (ranging up to a maximum of 30 exposures). Using this extensive data set we find that about 16% of the sources exhibit H-alpha emission in at least one exposure, and of those about 45% exhibit H-alpha emission in all of the available exposures. Within the sample of objects with H-alpha emission, only 26% are consistent with non-variable emission, independent of spectral type. The H-alpha variability, quantified in terms of the ratio of maximum to minimum H-alpha equivalent width (R_EW), and the ratio of the standard deviation to the mean (sigma_EW/), exhibits a rapid rise from M0 to M5, followed by a plateau and a possible...

Kruse, E A; Knapp, G R; Gunn, J E; Loomis, C P; Lupton, R H; Schlegel, D J

2009-01-01

14

Resolving Stellar Atmospheres I: The H alpha line and comparisons to microlensing observations  

CERN Document Server

We present work on H alpha spectral line characteristics in PHOENIX stellar model atmospheres and their comparison to microlensing observations. We examine in detail the H alpha equivalent width (EW) and the line shape characteristics for effective temperatures of 4500K< Teff < 5600K where H alpha is a strong spectral feature. We find that H alpha EW in models calculated under the assumption of local thermodynamic equilibrium (LTE) is up to 15% smaller than in models without this assumption, non-LTE models (NLTE) and that line shapes vary significantly for the two model types. A comparison with available high quality microlensing data, capable of tracing H alpha absorption across the face of one G5III giant, shows that the LTE model that fits the EW best is about 100K hotter than and the best-fitting NLTE model has a similar Teff as predicted by the spectral type analysis of the observed star but agree within the uncertainties of the observationally derived temperature. Neither LTE nor NLTE models fit t...

Thurl, C; Hauschildt, P H; Thurl, Christine; Sackett, Penny D.; Hauschildt, Peter H.

2006-01-01

15

Spectropolarimetry of Venus and Jupiter clouds - Information content of equivalent widths  

Science.gov (United States)

The theory of the curve-of-growth for absorption lines formed in an anisotropically scattering medium, particularly the clouds of Venus and Jupiter, is generalized to the case of polarization. When the photon path-length distributions associated with each of Stokes' parameters (Il, Ir, and Q) are evaluated using Pade's approximations, analytical expressions can be derived for the corresponding equivalent widths. It is found that spectra of Q, derivable from the rotational temperature of the Q-lines, are formed at a level closer to the cloud top than the photopolarimetric level, rendering a more accurate location of the cloud top than possible by photopolarization. It is also demonstrated that simultaneous measurements of the equivalent widths of strong I- and Q-lines can provide analytical relations for retrieving the scale-height ratios of ambient gas-to-cloud particles and minor constituent-to-ambient gas molecules without resorting to any other independent measurement.

Buriez, J. C.; Fouquart, Y.; Fymat, A. L.

1979-01-01

16

The reddening law of Type Ia Supernovae: separating intrinsic variability from dust using equivalent widths  

CERN Document Server

We employ 76 type Ia supernovae with optical spectrophotometry within 2.5 days of B-band maximum light obtained by the Nearby Supernova Factory to derive the impact of Si and Ca features on supernovae intrinsic luminosity and determine a dust reddening law. We use the equivalent width of Si II {\\lambda}4131 in place of light curve stretch to account for first-order intrinsic luminosity variability. The resultant empirical spectral reddening law exhibits strong features associated with Ca II and Si II {\\lambda}6355. After applying a correction based on the Ca II H&K equivalent width we find a reddening law consistent with a Cardelli extinction law. Using the same input data, we compare this result to synthetic rest-frame UBVRI-like photometry in order to mimic literature observations. After corrections for signatures correlated with Si II {\\lambda}4131 and Ca II H&K equivalent widths, and introducing an empirical correlation between colors, we determine the dust component in each band. We find a value ...

Chotard, N; Aldering, G; Antilogus, P; Aragon, C; Bailey, S; Baltay, C; Bongard, S; Buton, C; Canto, A; Childress, M; Copin, Y; Fakhouri, H K; Hsiao, E Y; Kerschhaggl, M; Kowalski, M; Loken, S; Nugent, P; Paech, K; Pain, R; Pecontal, E; Pereira, R; Perlmutter, S; Rabinowitz, D; Runge, K; Scalzo, R; Smadja, G; Tao, C; Thomas, R C; Weaver, B A; Wu, C

2011-01-01

17

Wavelengths and equivalent widths in the spectra of cool barium stars  

International Nuclear Information System (INIS)

During the past several years we have been conducting a program of observation of cool stars with anomalies of the heavy elements. The purpose of the program is to derive abundances of the heavy elements in order to understand the neutron capture chains which very likely are the source of the abundance excesses. Wavelengths, line identifications and equivalent width measurements are presented for seven barium stars and two normal K-giant stars covering the spectral region lambda 5400-6850 A. The data were derived from photographic coude spectra obtained at dispersions of either 10 or 18 A/mm and echelle spectra of 5 A/mm

18

Bayesian Identification of Emission–Line Galaxies with Photometric Equivalent Widths  

Science.gov (United States)

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

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

2015-01-01

19

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

CERN Document Server

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

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

2014-01-01

20

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

International Nuclear Information System (INIS)

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

21

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

DEFF Research Database (Denmark)

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

Laursen, Peter; Duval, F.

2013-01-01

22

Ly{\\alpha} Equivalent Width Distribution at Redshift z $\\sim$ 4.5  

CERN Document Server

Ly{\\alpha} line equivalent widths (EWs) provide important clues to the physical nature of high redshift Lyman alpha emitters (LAEs). However, measuring the Ly{\\alpha} EW distribution of high-z narrowband selected LAEs can be hard because many sources do not have broadband photometry. We investigate the possible biases in measuring the intrinsic Ly{\\alpha} EW distribution for a LAE sample at z $\\sim$ 4.5 in the Extended Chandra Deep Field South (ECDFS). Only weak Malmquist-type bias in both the intrinsic Ly{\\alpha} luminosity function and the Ly{\\alpha} EW distribution were found. However, the observed EW distribution is severely biased if one only considers LAEs with detections in the continuum. Taking the broadband non-detections into account requires fitting the distribution of the broadband-to-narrowband ratio, which then gives a larger EW distribution scale length. Assuming an exponential form of the intrinsic Ly{\\alpha} EW distribution dN/dEW = N exp(-EW/W$_0$), we obtain W$_0$ = 167+/-44{\\AA} (uncorrect...

Zheng, Zhen-Ya; Malhotra, Sangeeta; Rhoads, James E; Finkelstein, Steven L; Finkelstein, Keely

2013-01-01

23

UV/H-alpha Turmoil  

CERN Document Server

A great deal of our understanding of star formation in the local universe has been built upon an extensive foundation of H-alpha observational studies. However, recent work in the ultraviolet (UV) with GALEX has shown that star formation rates (SFRs) inferred from H-alpha in galactic environments characterized by low stellar and gas densities tend to be less than those based on the UV luminosity. The origin of the discrepancy is actively debated because one possible explanation is that the stellar initial mass function is systematically deficient in high mass stars in such environments. In this contribution, we summarize our work on this topic using a dwarf galaxy dominated sample of ~300 late-type galaxies in the 11 Mpc Local Volume. The sample allows us to examine the discrepancy between H-alpha and UV SFRs using a statistical number of galaxies with activities less than 0.1 Msun/yr. A range of potential causes for such an effect are reviewed. We find that while the IMF hypothesis is not inconsistent with o...

Lee, Janice C; Tremonti, Christy; Kennicutt, Robert

2010-01-01

24

Simultaneous H$\\alpha$, NaI D$_{1}$, D$_{2}$, and HeI D$_{3}$ observations of a flare on the RS CVn system UX Ari  

CERN Document Server

We present simultaneous H\\alpha, Na~{\\sc i} D_{1}, D_{2}, and He~{\\sc i} D_{3} spectroscopic observations on the RS CVn system UX Ari. We have found a dramatic increase in the excess H\\alpha emission equivalent width by a factor of 2 in an interval of 1 day that indicates the beginning of a strong flare in this system. The presence of the He~{\\sc i} D_{3} in emission in coincidence with the enhancement of the H\\alpha emission confirms the detection of a flare. The application of the spectral subtraction technique reveals that the core of the Na~{\\sc i} D_{1} and D_{2} lines are also filled-in by chromospheric emission.

Montes, D; Fernández-Figueroa, M J; Lorente, R

1996-01-01

25

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

CERN Document Server

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

Sriram, K; Rao, P Vivekananda

2014-01-01

26

Ly? EMITTERS IN HIERARCHICAL GALAXY FORMATION. II. ULTRAVIOLET CONTINUUM LUMINOSITY FUNCTION AND EQUIVALENT WIDTH DISTRIBUTION  

International Nuclear Information System (INIS)

We present theoretical predictions of the UV continuum luminosity function (UV LF) and Ly? equivalent width (EW) distribution of Ly? emitters (LAEs) in the framework of the hierarchical clustering model of galaxy formation. The model parameters for the LAEs were determined by fitting to the observed Ly? LF at z = 5.7 in our previous study, and the fit indicates that extinction of Ly? photons by dust is significantly less effective than that of UV continuum photons, implying a clumpy dust distribution in the interstellar medium. We then compare the predictions about UV LFs and EW distributions with a variety of observations at z? 3-6, allowing no more free parameters and paying careful attention to the selection conditions of LAEs in each survey. We find that the predicted UV LFs and EW distributions are in nice agreement with observed data, and especially, our model naturally reproduces the existence of large EW LAEs (?> 240 A) without introducing Pop III stars or top-heavy initial mass function. We show that both the stellar population (young age and low metallicity) and extinction by clumpy dust are the keys to reproducing large EW LAEs. The evidence of EW enhancement by clumpy dust is further strengthened by the quantitative agreement between our model and recent observations about a positive correlation between EW and extinction. The observed trend that brighter LAEs in the UV continuum tend to have smaller mean EW is also reproduced, and the clumpy dust p reproduced, and the clumpy dust plays an important role again for this trend. We suggested in our previous study that the transmission of the intergalactic medium for Ly? emission rapidly decreases from z ? 6 to 7 by fitting to Ly? LFs, and this evidence is quantitatively strengthened by the comparison with the UV LF and EW distribution at z ? 6.6.

27

Ly? equivalent width distribution of Ly? emitting galaxies at redshift z ˜ 4.5  

Science.gov (United States)

Ly? line equivalent widths (EWs) provide important clues to the physical nature of high-redshift Lyman alpha emitters (LAEs). However, measuring the Ly? EW distribution of high-z narrow-band-selected LAEs can be hard because many sources do not have well-measured broad-band photometry. We investigate the possible biases in measuring the intrinsic Ly? EW distribution for a LAE sample at z ˜ 4.5 in the Extended Chandra Deep Field South (ECDFS). We show that our source selection procedures produce only weak Eddington type bias in both the intrinsic Ly? luminosity function and the Ly? EW distribution. However, the observed EW distribution is severely biased if one only considers LAEs with detections in the continuum. Taking the broad-band non-detections into account requires fitting the distribution of the broad-band-to-narrow-band ratio, which then gives a larger EW distribution scale length. Assuming an exponential form of the intrinsic Ly? EW distribution {d}N/{dEW} = N exp ^{-EW/W_0}, we obtain W0 = 167^{+44}_{-19} Å (uncorrected for IGM absorption of Ly?, and ?g = 160^{+43}_{-12} Å for a Gaussian EW distribution). We discuss the likely range of IGM absorption effects in light of recent measurements of Ly? line profiles and velocity offsets. Our data are consistent with Ly? EW being independent of UV luminosity (i.e. we do not see evidence for the `Ando' effect). Our simulations also imply that broad-band images should be 0.5-1 mag deeper than narrow-band images for an effective and reasonably complete LAE survey. Comparing with consistent measurements at other redshifts, we see a strong evolution in Ly? EW distribution with redshift which goes as a power-law form of W0 ? (1 + z)?, with ? = 1.1 ± 0.1 (0.6 ± 0.1) if no IGM corrections are applied to the Ly? line; or ? = 1.7 ± 0.1 (1.2 ± 0.1) after applying a maximal IGM-absorption correction to Ly? line for an exponential (a Gaussian) EW distribution from z = 0.3 to 6.5.

Zheng, Zhen-Ya; Wang, Jun-Xian; Malhotra, Sangeeta; Rhoads, James E.; Finkelstein, Steven L.; Finkelstein, Keely

2014-03-01

28

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

CERN Document Server

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...

Aksaker, Naz\\im

2012-01-01

29

Temporal evolution of mottles observed in H_alpha  

CERN Document Server

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.

Bostanci, Z F; Erdogan, Nurol Al

2007-01-01

30

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

CERN Document Server

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

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

2012-01-01

31

On the equivalent width of the Fe K$\\alpha$ line produced by a dusty absorber in active galactic nuclei  

CERN Document Server

Obscured AGNs provide an opportunity to study the material surrounding the central engine. Geometric and physical constraints on the absorber can be deduced from the reprocessed AGN emission. In particular, the obscuring gas may reprocess the nuclear X-ray emission producing a narrow Fe K$\\alpha$ line and a Compton reflection hump. In recent years, models of the X-ray reflection from an obscuring torus have been computed; however, although the reflecting gas may be dusty, the models do not yet take into account the effects of dust on the predicted spectrum. We study this problem by analyzing two sets of models, with and without the presence of dust, using the one dimensional photo-ionization code Cloudy. The calculations are performed for a range of column densities ($22 <{\\rm log}[N_H(\\rm cm^{-2})]< 24.5$ ) and hydrogen densities ( $6 <{\\rm log}[n_H(\\rm cm^{-3})]< 8$). The calculations show the presence of dust can enhance the Fe K$\\alpha$ equivalent width (EW) in the reflected spectrum by factor...

Gohil, Raj

2015-01-01

32

H-alpha variability in Alpha Lyrae  

International Nuclear Information System (INIS)

Observations of Alpha Lyr obtained in a 36-nm band centered on H-alpha using a rapid-scanning spectrophotometer with entrance slit 120 microns, exit slit 250 microns, FWHM resolution 650 pm, and scan duration 4.28 min at the Cassegrain focus of the 61-cm reflecting telescope at Yerkes Observatory over 17.5 h on six nights spanning 43 days in July-August 1984, are reported. A typical scan is presented graphically, and no variability of the type observed by Goraya and Singh (1983) in October 1983, is found

33

The KPNO International Spectroscopic Survey. II. H-alpha Selected Survey List 1  

CERN Document Server

The KPNO International Spectroscopic Survey (KISS) is a new objective-prism survey for 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. Here we present the first list of emission-line galaxy candidates selected from our red spectral data, which cover the spectral range 6400 to 7200 Angstroms. In most cases, the detected emission line is H-alpha. The current survey list covers a one-degree-wide strip located at Dec (1950) = 29.5 degrees and spanning the RA range 12h 15m to 17h 0m. An area of 62.2 sq. degrees is covered. A total of 1128 candidate emission-line objects have been selected for inclusion in the survey list (18.1 per sq. degree). We tabulate accurate coordinates and photometry for each source, as well as estimates of the redshift and emission-line flux and equivalent width based on measurements of the digital o...

Salzer, J J; Lipovetsky, V A; Kniazev, A Yu; Moody, J W; Boroson, T A; Thuan, T X; Izotov, Yu I; Herrero, J L; Frattare, L M

2000-01-01

34

Discovery of H alpha absorption in the unusual broad absorption line quasar SDSS J083942.11+380526.3  

CERN Document Server

We discovered an H alpha absorption in a broad H alpha emission line of an unusual broad absorption line quasar, SDSS J083942.11+380526.3 at z=2.318, by near-infrared spectroscopy with the Cooled Infrared Spectrograph and Camera for OHS (CISCO) on the Subaru telescope. The Presence of non-stellar H alpha absorption is known only in the Seyfert galaxy NGC 4151 to date, thus our discovery is the first case for quasars. The H alpha absorption line is blueshifted by 520 km/s relative to the H alpha emission line, and its redshift almost coincides with those of UV low-ionization metal absorption lines. The width of the H alpha absorption (~ 340 km/s) is similar to those of the UV low-ionization absorption lines. These facts suggest that the H alpha and the low-ionization metal absorption lines are produced by the same low-ionization gas which has a substantial amount of neutral gas. The column density of the neutral hydrogen is estimated to be ~ 10^18 cm^-2 by assuming a gas temperature of 10,000 K from the analys...

Aoki, K; Ohta, K; Ando, M; Akiyama, M; Tamura, N; Aoki, Kentaro; Iwata, Ikuru; Ohta, Kouji; Ando, Masataka; Akiyama, Masayuki; Tamura, Naoyuki

2006-01-01

35

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2012-10-20

36

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

OpenAIRE

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

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

2013-01-01

37

Comparing Ultraviolet and H alpha Star Formation Rates  

CERN Document Server

We have used a sample of 43 star-forming galaxies imaged in the far-ultraviolet (FUV) by the UIT supplemented with 33 galaxies observed by FAUST, to explore the consistency of UV and H alpha derived star formation rates (SFRs). We find, even before correction for dust, that UV and H alpha SFRs are quantitatively consistent for low-luminosity galaxies, and that higher luminosity galaxies have H alpha SFRs a factor of 1.5 higher than their UV SFRs: this reflects the influence of dust. Our results are consistent with a scenario where the UV dust extinction is a factor of less than 2 larger than the H alpha dust extinction in a given galaxy, and that there is over a 4 magnitude range of H alpha dust extinctions which correlate loosely with galaxy luminosity such that low luminosity galaxies tend to have lower extinctions than their higher luminosity counterparts.

Bell, E F

2000-01-01

38

Kelvin--Helmholtz instability in solar H-alpha surges  

CERN Document Server

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...

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

2015-01-01

39

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

CERN Document Server

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

Seon, Kwang-Il

2012-01-01

40

Scattered H-alpha light from Galactic dust clouds  

CERN Document Server

Bright emission nebulae, or HII regions, around hot stars are readily seen in H-alpha light. However, the all-pervasive faint H-alpha emission has only recently been detected and mapped over the whole sky. Mostly the H-alpha emission observed along a line of sight is produced by ionised gas in situ. There are, however, cases where all or most of the H-alpha radiation is due to scattering by electrons or dust particles which are illuminated by an H-alpha emitting source off the line of sight. Here we demonstrate that diffuse, translucent and dark dust clouds at high galactic latitudes are in many cases observed to have an excess of diffuse H-alpha surface brightness, i.e. they are brighter than the surrounding sky. We show that the majority of this excess surface brightness can be understood as light scattered off the interstellar dust grains. The source of incident photons is the general Galactic H-alpha background radiation impinging on the dust clouds from all over the sky.

Mattila, K; Lehtinen, K

2006-01-01

41

Equivalent width, shape and proper motion of the iron fluorescent line emission from molecular clouds as an indicator of the illuminating source X-ray flux history  

Science.gov (United States)

Observations of the diffuse emission in the 8-22 keV energy range, elongated parallel to the Galactic plane, and detection of the strong 6.4-keV fluorescent line with ~1 keV equivalent width from some giant molecular clouds (e.g. Sgr B2) in the Galactic Centre region suggest that the neutral matter of these clouds is (or was) illuminated by powerful X-ray radiation, which gave rise to the reprocessed radiation. The source of this radiation remains unknown. A transient source close to the Sgr B2 cloud, or a short outburst of the X-ray emission from a supermassive black hole at the Galactic Centre are the two prime candidates under consideration. We argue that a new generation of X-ray telescopes combining very high sensitivity and excellent energy and angular resolutions would be able to discriminate between these two possibilities when studying time-dependent changes of the morphology of the surface brightness distribution, the equivalent width and the shape of the fluorescent line in Sgr B2 and other molecular clouds in the region. We note also that detection of broad and complex structures near the 6.4-keV line in the spectra of distant AGNs, which are X-ray weak now, may prove the presence of violent activity in the central engines of these objects in the past. Accurate measurements of the line shape may provide information on the time elapsed since the outburst. Proper motion (super- or subluminal) of the fluorescent radiation wave front can give additional information on the location of the source. Observations of the described effects can provide unique information on the matter distribution inside Sgr B2 and other giant molecular clouds.

Sunyaev, R.; Churazov, E.

1998-07-01

42

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

CERN Document Server

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...

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

2013-01-01

43

The profile and equivalent width of the X-ray iron emission-line from a disk around a Kerr black hole  

CERN Document Server

Recent X-ray observations have shown broad, skewed iron line emission from Seyfert 1 galaxies which is explained by the emission being fluorescence on a disk close to a black hole. During one interval, the line in MCG--6-30-15 was so broad and redshifted that a Kerr black hole is implied. We are therefore studying the effects of the Kerr metric on the line profile, and extending the work by Laor and Kojima which dealt only with extreme values of the spin parameter. Here we report that the spin parameter of the black hole in MCG--6-30-15 is high (a/M>0.94), and invert the line profile to obtain the disk emissivity profile, which approximates a power-law. Continuum radiation returning to the disk because of the Kerr metric does not enhance the equivalent width of the line seen above 3 keV by more than about 20 per cent if the continuum source corotates with the disk.

Dabrowski, Y; Iwasawa, K; Lasenby, A N; Reynolds, C S

1997-01-01

44

H-alpha Spectral diversity of type II supernovae  

DEFF Research Database (Denmark)

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

P. Gutiérrez, Claudia; P. Anderson, Joseph

2014-01-01

45

H\\alpha\\ Emission Variability in Active M Dwarfs  

CERN Document Server

We use ~12,000 spectra of ~3,500 magnetically active M0-M9 dwarfs from the Sloan Digital Sky Survey taken at 10-15 minute intervals, together with ~300 spectra of ~60 M0-M8 stars obtained hourly with the Hydra multi-object spectrometer, to probe H\\alpha\\ variability on timescales of minutes to weeks. With multiple observations for every star examined, we are able to characterize fluctuations in H\\alpha emission as a function of activity strength and spectral type. Stars with greater magnetic activity (as quantified by L_H\\alpha/L_bol) are found to be less variable at all spectral types. We attribute this result to the stronger level of persistent emission in the high activity stars, requiring a larger heating event in order to produce measurable variability. We also construct H\\alpha\\ structure functions to constrain the timescale of variability. The more active objects with lower variability exhibit a characteristic timescale longer than an hour, likely due to larger, longer lasting heating events, while the...

Bell, Keaton J; Davenport, James R A; Hawley, Suzanne L; West, Andrew A; Rogel, Allen B

2011-01-01

46

H-alpha imaging of galaxies in the Bootes void  

Science.gov (United States)

We report H-alpha and continuum imaging of 12 galaxies in the Bootes void. The H-alpha emission in ten galaxies is due to star formation; one galaxy is probably a narrow emission line Active Galactic Nuclei (AGN), and one a Seyfert 1. Star formation rates range from 3-55 solar mass/yr, with the most active galaxies producing stars at almost three times the rate found in normal field disk systems. Eleven galaxies have strong H-alpha emission in the nucleus. The morphology of several of the galaxies is disturbed. There are at least five spirals, three of which are probably one-armed spirals, and three edge-on disk systems. Three galaxies not identifiable as spirals have H-alpha emission from regions outside the nuclear point source. 1510+4727, which has the highest rate of star formation in our sample, does not have the strong far-infrared emission expected from a galaxy experiencing significant star formation. The galaxies are quite luminous M(sub B) = -21 to -23 mag), and are not the type predicted to be found in voids.

Weistrop, D.; Hintzen, P.; Liu, C.; Lowenthal, J.; Cheng, K. -P.; Oliversen, R.; Brown, L.; Woodgate, B.

1995-01-01

47

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

CERN Document Server

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...

Brownsberger, Sasha

2014-01-01

48

Variable H-alpha Line Emission from the Central Star of the Helix Nebula  

CERN Document Server

The central star of the Helix Nebula is a hot white dwarf with unexpected hard X-ray emission. With an effective temperature of ~100,000 K, the star is a powerful source of H-ionizing radiation; the atmosphere of a stellar or planetary companion, if present, will be ionized and emit recombination lines. To probe the origin of hard X-ray emission from the Helix Nebula's central star, we have obtained multi-epoch high-dispersion spectra of the star, and found temporal variation in the H-alpha line profile over a time span of one week. The observed width and strength of the variable H-alpha emission component are consistent with the hypothesized dMe companion proposed to explain the hard X-ray emission. A dMe companion, however, cannot explain the possible detection of variable HeII and [NII] emission. Follow-up spectroscopic monitoring of the Helix Nebula central star is needed to better establish the identification of the spectral lines and their temporal behavior in order to determine the origin of the optica...

Gruendl, R A; O'Dwyer, I J; Guerrero, M A; Gruendl, Robert A.; Chu, You-Hua; Dwyer, Ian J. O'; Guerrero, Martin A.

2001-01-01

49

A Detection Of H-alpha In An Exoplanetary Exosphere  

CERN Document Server

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...

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

2012-01-01

50

The Aao/Ukst Supercosmos H-alpha Survey (SHS)  

CERN Document Server

The UK Schmidt Telescope (UKST) of the Anglo-Australian Observatory completed a narrow-band H-alpha plus [NII] 6548, 6584A survey of the Southern Galactic Plane and Magellanic Clouds in late 2003. The survey, which was the last UKST wide-field photographic survey, and the only one undertaken in a narrow band, is now an on-line digital data product of the Wide-Field Astronomy Unit of the Royal Observatory Edinburgh (ROE). The survey utilised a high specification, monolithic H-alpha interference band-pass filter of exceptional quality. In conjunction with the fine grained Tech-Pan film as a detector it has produced a survey with a powerful combination of area coverage (4000 square degrees), resolution (~1 arcsecond) and sensitivity (<=5 Rayleighs), reaching a depth for continuum point sources of R~20.5. The main survey consists of 233 individual fields on a grid of centres separated by 4 degrees at declinations below +2 degrees and covers a swathe approximately 20 degrees wide about the Southern Galactic Pla...

Parker, Q A; Pierce, M J; Hartley, M; Hambly, N C; Read, M A; MacGillivray, H T; Tritton, S B; Cass, C P; Cannon, R D; Cohen, M; Drew, J E; Frew, D J; Hopewell, E; Mader, S; Malin, D F; Masheder, M R W; Morgan, D H; Morris, R A H; Russeil, D; Russell, K S; Walker, R N F

2005-01-01

51

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

CERN Document Server

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...

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

2007-01-01

52

Observational Tests to Detect Photometric Reverberation in H-alpha  

Science.gov (United States)

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

Joner, Michael D.; Carroll, Carla

2014-06-01

53

Pulsar H(alpha) Bowshocks probe Neutron Star Physics  

Science.gov (United States)

We propose a KOALA/AAOmega study of southern pulsar bow shocks. These rare, Balmer-dominated, non-radiative shocks provide an ideal laboratory to study the interaction of the relativistic pulsar wind with the ISM. We will cover H(alpha) at high spectral resolution to measure the kinematics of the upstream ISM and the post-shock flow, while the blue channel measures the Balmer decrement and probes for a faint cooling component. These data, with MHD models, allow us to extract the 3D flow geometry and the orientation and asymmetry of the pulsar wind. These data can also measure the pulsar spindown power, thus estimating the neutron star moment of inertia and effecting a fundamental test of dense matter physics.

Romani, Roger W.

2014-08-01

54

A Comparison of UIT Far-Ultraviolet and H alpha Star Formation Rates  

OpenAIRE

We have used archival ultraviolet (UV) imaging of 50 nearby star-forming galaxies obtained with the Ultraviolet Imaging Telescope (UIT) to derive integrated near-UV and far-UV magnitudes, and have combined these data with H alpha, far-infrared, and thermal radio continuum measurements to explore the consistency of UV and H alpha star formation rates (SFRs). In agreement with previous studies, we find that the UV and H alpha SFRs are qualitatively consistent, even before corr...

Bell, Eric F.; Kennicutt Jr, Robert C.

2000-01-01

55

A Ly-alpha Emitter with an Extremely Large Rest-frame Equivalent Width of ~900A at z=6.5: A Candidate of Population III-dominated Galaxy?  

CERN Document Server

We have identified a very interesting Ly-alpha emitter, whose Ly-alpha emission line has an extremely large observed equivalent width of EW_0=436^{+422}_{-149}A, which corresponds to an extraordinarily large intrinsic rest-frame equivalent width of EW_0^{int}=872^{+844}_{-298}A after the average intergalactic absorption correction. The object was spectroscopically confirmed to be a real Ly-alpha emitter by its apparent asymmetric Ly-alpha line profile detected at z=6.538. The continuum emission of the object was definitely detected in our deep z'-band image; thus, its EW_0 was reliably determined. Follow-up deep near-infrared spectroscopy revealed emission lines of neither He II lambda1640 as an apparent signature of Population III, nor C IV lambda1549 as a proof of active nucleus. No detection of short-lived He II lambda1640 line is not necessarily inconsistent with the interpretation that the underlying stellar population of the object is dominated by Population III. We found that the observed extremely lar...

Kashikawa, Nobunari; Toshikawa, Jun; Ishizaki, Yoshifumi; Egami, Eiichi; Hayashi, Masao; Ly, Chun; Malkan, Matthew A; Matsuda, Yuichi; Shimasaku, Kazuhiro; Iye, Masanori; Ota, Kazuaki; Shibuya, Takatoshi; Jiang, Linhua; Taniguchi, Yoshiaki; Shioya, Yasuhiro

2012-01-01

56

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

Science.gov (United States)

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.

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

2012-01-01

57

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2012-12-20

58

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

CERN Document Server

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

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

2010-01-01

59

Coordinated soft X-ray and H-alpha observation of solar flares  

Science.gov (United States)

Soft X-ray, Ca XIX, and H-alpha observations obtained for a set of four solar flares in the impulsive phase are analyzed. A blue asymmetry was observed in the coronal Ca XIX line during the soft-Xray rise phase in all of the events. A red asymmetry was observed simultaneously in chromospheric H-alpha at spatial locations associated with enhanced flare heating. It is shown that the impulsive phase momentum of upflowing soft X-ray plasma equalled that of the downflowing H-alpha plasma to within an order of magnitude. This supports the explosive chromospheric evaporation model of solar flares.

Zarro, D. M.; Canfield, R. C.; Metcalf, T. R.; Lemen, J. R.

1988-01-01

60

Luminosities of H alpha emitting regions in a pair of interacting galaxies in the Bootes void  

Science.gov (United States)

Luminosities of H alpha emission from a pair of interacting galaxies in the low density environment of the Bootes void are presented. CG 692 (IRAS 1519+5050) has an H alpha luminosity of 2 x 10(exp 42) ergs s(exp -1), indicating a star formation rate of 18.4 solar mass yr(exp -1). Individual extranuclear H alpha regions have luminosities of approximately 10(exp 40) ergs s(exp -1). These luminosities are similar to those found for H II regions in bright, late-type galaxies in more densely populated parts of the Universe.

Weistrop, D.; Hintzen, P.; Kennicutt, R.; Liu, C.; Lowenthal, J.; Cheng, K.-P.; Oliversen, R.; Woodgate, B.

1993-01-01

61

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

CERN Document Server

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

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

2011-01-01

62

H[alpha]-stability of modified Runge-Kutta methods for nonlinear neutral pantograph equations  

Science.gov (United States)

In this paper, we investigate H[alpha]-stability of algebraically stable Runge-Kutta methods with a variable stepsize for nonlinear neutral pantograph equations. As a result, the Radau IA, Radau IIA, Lobatto IIIC method, the odd-stage Gauss-Legendre methods and the one-leg [theta]-method with are H[alpha]-stable for nonlinear neutral pantograph equations. Some experiments are given.

Ma, S. F.; Yang, Z. W.; Liu, M. Z.

2007-11-01

63

Soft Cores in Late-Type Dwarf and LSB Galaxies from H\\alpha Observations  

OpenAIRE

We present high spatial resolution H\\alpha rotation curves of late-type dwarf and LSB galaxies. From our analysis we find good agreement between our H\\alpha data and the HI observations taken from the literature, concluding that the HI rotation curves for these galaxies suffer very little from beam smearing. A preliminary analysis of our data rules out the CDM model in the inner regions of these galaxies.

Marchesini, D.; D Onghia, E.; Chincarini, G.; Firmani, C.; Conconi, P.; Molinari, E.; Zacchei, A.

2001-01-01

64

H-alpha variability of the recurrent nova T Coronae Borealis  

CERN Document Server

We analyze H-alpha observations of the recurrent nova T CrB obtained during the last decade. For the first time the H-alpha emission profile is analyzed after subtraction of the red giant contribution. Based on our new radial velocity measurements of the H-alpha emission line we estimate the component masses of T CrB. It is found that the hot component is most likely a massive white dwarf. We estimate the inclination and the component masses to be i~67 deg, Mwd = 1.37 +/-0.13 Msun and Msec=1.12 +/-0.23 Msun, respectively. The radial velocity of the central dip in the H-alpha profile changes nearly in phase with that of the red giant's absorption lines. This suggests that the dip is most likely produced by absorption in the giant's wind. Our observations cover an interval when the H-alpha and the U-band flux vary by a factor of ~6, while the variability in B and V is much smaller. Based on our observations, and archival ultraviolet and optical data we show that the optical, ultraviolet and H-alpha fluxes stron...

Stanishev, V; Tomov, N; Marziani, P

2003-01-01

65

Dust Attenuation and H-alpha Star Formation Rates of z~0.5 Galaxies  

CERN Document Server

Using deep narrow-band and broad-band imaging, we identify 401 z~0.40 and 249 z~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^{+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 modeli...

Ly, Chun; Kashikawa, Nobunari; Ota, Kazuaki; Shimasaku, Kazuhiro; Iye, Masanori; Currie, Thayne

2012-01-01

66

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

CERN Document Server

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...

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

1999-01-01

67

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

Science.gov (United States)

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

Radziszewski, Krzysztof; Rudawy, Pawel

68

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

CERN Document Server

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 ...

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

69

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

CERN Document Server

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

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

2012-01-01

70

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

CERN Document Server

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...

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

2012-01-01

71

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

CERN Document Server

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.

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

2000-01-01

72

MONITORING H{alpha} EMISSION AND CONTINUUM OF UXORs: RR Tauri  

Energy Technology Data Exchange (ETDEWEB)

The Maria Mitchell Observatory, in collaboration with the Astrokolkhoz Observatory, started a program of photometric monitoring of UX Ori-type stars (UXORs) with narrowband interference filters (IFs; augmented with the traditional broadband filters) aimed at separating the H{alpha} emission variations from those of the continuum. We present the method of separation and the first results for RR Tau obtained in two seasons, each roughly 100 days long (2010 Winter-Spring and 2010 Fall-2011 Spring). We confirm the conclusion from previous studies that the H{alpha} emission in this star is less variable than the continuum. Although some correlation between the two is not excluded, the amplitude of H{alpha} variations is much smaller (factors of 3-5) than that of the continuum. These results are compatible with Grinin's model of UXORs, which postulates the presence of small obscuring circumstellar clouds as the cause of the continuum fading, as well as the presence of a circumstellar reflection/emission nebula, larger than the star and the obscuring clouds, which is responsible for H{alpha} emission and the effect of the 'color reversal' in deep minima. However, the results of both our broadband and narrowband photometry indicate that the obscuration model may be insufficient to explain all of the observations. Disk accretion, the presence of stellar or (proto) planetary companion(s), as well as the intrinsic variations of the star, may contribute to the observed light variations. We argue, in particular, that the H{alpha} emission may be more closely correlated with the intrinsic variations of the star than with the much stronger observed variations caused by the cloud obscuration. If this hypothesis is correct, the close monitoring of H{alpha} emission with IFs, accessible to small-size telescopes, may become an important tool in studying the physical nature of the UXORs' central stars.

Bedell, Megan; Villaume, Alexa; Weiss, Lauren; Sliski, David; Strelnitski, Vladimir; Walker, Gary; Williams, Jedediyah [Maria Mitchell Observatory, 4 Vestal Street, Nantucket, MA 02554 (United States); Henden, Arne [AAVSO, 49 Bay State Road, Cambridge, MA 02138 (United States); Krajci, Tom [Astrokolkhoz Observatory, P.O. Box 1351, Cloudcroft, NM 88317 (United States)

2011-11-15

73

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

CERN Document Server

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} .

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

2007-01-01

74

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

OpenAIRE

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

Andjelic, M.; Stavrev, K.; Arbutina, B.; Ilic, D.; Urosevic, D.

2011-01-01

75

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

OpenAIRE

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...

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

2014-01-01

76

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

CERN Document Server

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...

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

77

First Simultaneous Observation of H-alpha Moreton Wave, EUV Wave, and Filament/Prominence Oscillations  

CERN Document Server

We report on the first simultaneous observation of an H-alpha Moreton wave, the corresponding EUV fast coronal waves, and a slow and bright EUV wave (typical EIT wave). Associated with an X6.9 flare that occurred on 2011 August 9 at the active region NOAA 11263, we observed a Moreton wave in the H-alpha images taken by the Solar Magnetic Activity Research Telescope (SMART) at Hida Observatory of Kyoto University. In the EUV images obtained by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamic Observatory (SDO) we found not only the corresponding EUV fast "bright" coronal wave, but also the EUV fast "faint" wave that is not associated with the H-alpha Moreton wave. We also found a slow EUV wave, which corresponds to a typical EIT wave. Furthermore, we observed, for the first time, the oscillations of a prominence and a filament, simultaneously, both in the H-alpha and EUV images. To trigger the oscillations by the flare-associated coronal disturbance, we expect a coronal wave as fast as the fast...

Asai, Ayumi; Isobe, Hiroaki; Kitai, Reizaburo; UeNo, Satoru; Nagata, Shin'ichi; Morita, Satoshi; Nishida, Keisuke; Shiota, Daikou; Oi, Akihito; Akioka, Maki; Shibata, Kazunari

2011-01-01

78

DISCOVERY OF AN H{alpha} EMITTING DISK AROUND THE SUPERMASSIVE BLACK HOLE OF M31  

Energy Technology Data Exchange (ETDEWEB)

Due to its proximity, the mass of the supermassive black hole in the nucleus of the Andromeda galaxy (M31), the most massive black hole in the Local Group of galaxies, has been measured by several methods involving the kinematics of a stellar disk which surrounds it. We report here the discovery of an eccentric H{alpha} emitting disk around the black hole at the center of M31 and show how modeling this disk can provide an independent determination of the mass of the black hole. Our model implies a mass of 5.0{sup +0.8}{sub -1.0} Multiplication-Sign 10{sup 7} M{sub Sun} for the central black hole, consistent with the average of determinations by methods involving stellar dynamics, and compatible (at 1{sigma} level) with measurements obtained from the most detailed models of the stellar disk around the central black hole. This value is also consistent with the M-{sigma} relation. In order to make a comparison, we applied our simulation on the stellar kinematics in the nucleus of M31 and concluded that the parameters obtained for the stellar disk are not formally compatible with the parameters obtained for the H{alpha} emitting disk. This result suggests that the stellar and the H{alpha} emitting disks are intrinsically different from each other. A plausible explanation is that the H{alpha} emission is associated with a gaseous disk. This hypothesis is supported by the detection of traces of weaker nebular lines in the nuclear region of M31. However, we cannot exclude the possibility that the H{alpha} emission is, at least partially, generated by stars.

Menezes, R. B.; Steiner, J. E.; Ricci, T. V., E-mail: robertobm@astro.iag.usp.br [Instituto de Astronomia Geofisica e Ciencias Atmosfericas, Universidade de Sao Paulo, Rua do Matao 1226, Cidade Universitaria, Sao Paulo, SP CEP 05508-090 (Brazil)

2013-01-10

79

Morphology of flaring kernels with asymmetrically-broadened H-alpha emission  

International Nuclear Information System (INIS)

The emission of two flares of the two-ribbon type, without filament eruptions, is concentrated in small kernels which are preferentially brighter at wavelengths that are displaced towards the H-alpha red wing. The evolution of the kernels in space and time implies that the energy of both flares is released in a succession of isolated bursts which increase rapidly in number during the impulsive phase. In a highly resolved medium-intensity limb flare, most of the H-alpha core is obscured by foreground features of average chromospheric height. For all three events considered, the energy dissipated in the low atmosphere is initially confined in closely packed kernels which are understood to be the footprints of low, stationary magnetic loops that straddle polarity-reversal lines. 11 references

80

H-alpha Emission Variability in the gamma-ray Binary LS I +61 303  

CERN Document Server

LS I +61 303 is an exceptionally rare example of a high mass X-ray binary (HMXB) that also exhibits MeV-TeV emission, making it one of only a handful of "gamma-ray binaries". Here we present H-alpha spectra that show strong variability during the 26.5 day orbital period and over decadal time scales. We detect evidence of a spiral density wave in the Be circumstellar disk over part of the orbit. The H-alpha line profile also exhibits a dramatic emission burst shortly before apastron, observed as a redshifted shoulder in the line profile, as the compact source moves almost directly away from the observer. We investigate several possible origins for this red shoulder, including an accretion disk, mass transfer stream, and a compact pulsar wind nebula that forms via a shock between the Be star's wind and the relativistic pulsar wind.

McSwain, M Virginia; Gies, Douglas R; Ray, Paul S

2010-01-01

81

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

OpenAIRE

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 ...

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

2013-01-01

82

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2012-06-15

83

Constraints on core-collapse supernova progenitors from correlations with H-alpha emission  

CERN Document Server

We present observational constraints on the nature of the different core-collapse supernova types through an investigation of the association of their explosion sites with recent star formation, as traced by H-alpha +[NII] line emission. We discuss results on the analysed data of the positions of 168 core-collapse supernovae with respect to the H-alpha emission within their host galaxies. From our analysis we find that overall the type II progenitor population does not trace the underlying star formation. Our results are consistent with a significant fraction of SNII arising from progenitor stars of less than 10 solar masses. We find that the supernovae of type Ib show a higher degree of association with HII regions than those of type II (without accurately tracing the emission), while the type Ic population accurately traces the H-alpha emission. This implies that the main core-collapse supernova types form a sequence of increasing progenitor mass, from the type II, to Ib and finally Ic. We find that the typ...

Anderson, J P

2008-01-01

84

Ultra-deep H-alpha Imaging of Nearby Dwarf Galaxies  

Science.gov (United States)

I will present new results on diffuse H-alpha emission in nearby dwarf galaxies. Observations have been obtained with the Magellan Maryland Tunable Filter, and are 8-10 times deeper in surface brightness than previous standard narrowband imaging of local galaxies. The new observations were initially motivated by the finding that the H-alpha flux from dwarf and low surface brightness galaxies systematically under-predicts the star formation rate relative to expectations based on the far ultraviolet flux. While detailed follow-up studies of many of the potential causes of the-lower-than-expected H-alpha fluxes have been performed, the possibility that previous imaging has missed a non-negligible fraction of the diffuse flux has not been addressed. I will show what the new observations reveal, and discuss implications for the measurement of the star formation rate, the propagation of ionizing photons into the halos of dwarf galaxies, and the properties of low-luminosity HII regions.

Lee, Janice C.

2015-01-01

85

The H alpha Luminosity Function of Morphologically Classified Galaxies in the Sloan Digital Sky Survey  

CERN Document Server

We present a study of the H$\\alpha$ line emission from a sample of 1482 optically-selected, morphologically-classified bright galaxies (median redshift of 0.05) derived from the Sloan Digital Sky Survey. The luminosity function is calculated for each morphological class and for the total sample. The luminosity function fitted with the Schechter form gives a slope $\\alpha=-1.43\\pm 0.10$ for the total sample and the H$\\alpha$ luminosity density is $10^{39.31\\pm 0.04{+0.10\\atop-0.07}}h$ erg s$^{-1}$Mpc$^{-3}$, where the first error is statistical and the second is systematic. This value is consistent with that derived by Gallego et al. (1995), but this agreement is caused by a fortuitous cancellation of their neglect of stellar absorption that affects the estimate of extinction corrections and a significant sample incompleteness of emission line galaxies. The fraction of H$\\alpha$ emitters monotonically increases from early (a few % for ellipticals) to late types (100% for irregular galaxies), whereas strong emi...

Nakamura, O; Brinkmann, J; Schneider, D P; Nakamura, Osamu; Fukugita, Masataka; Brinkmann, Jon; Schneider, Donald P.

2003-01-01

86

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

CERN Document Server

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

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

1998-01-01

87

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

CERN Document Server

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...

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

2006-01-01

88

The H-alpha stellar and interstellar emission in the open cluster NGC 6910  

CERN Document Server

We verify the nature of emission-line stars in the field of the open cluster NGC 6910. % Spectroscopy in the H-alpha region was obtained. Raw CCD frames of spectra of all stars fainter than V = 9 mag observed by us are significantly affected by nebular emission originating in the surrounding HII region IC 1318. After careful data reduction and subtraction of the nebular radiation we succeeded in obtaining reliable stellar spectra. We confirm that the star NGC 6910 37 is a Be star, and we have corrected the classification of V1973 Cyg from an Ae star to a normal A type star. Since the diffuse interstellar bands do not appear in the spectrum of this star while being present in the other stars we observed, we confirm that V1973 Cyg is a foreground object with respect to IC 1318 and NGC 6910. We also find that the H-alpha line in HD 194279 has a P Cygni profile and the H-alpha line profile is variable in HD 229196.

Kubat, J; Kawka, A; Pigulski, A; Slechta, M; Skoda, P

2007-01-01

89

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

CERN Document Server

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....

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

2014-01-01

90

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

CERN Document Server

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

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

2004-01-01

91

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

CERN Document Server

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...

Tziamtzis, A; Lundqvist, P; Sollerman, J

2009-01-01

92

Line polarization observed in chromospheric flares - Calculations for electron impact excitation of H-alpha  

Science.gov (United States)

The observation of chromospheric flares accompanying coronal flares in the sun indicates fast energy transfer between the two layers. Polarization observed in the H-alpha and S I lines can help to explain the nature of this energy transfer if accurate atomic data for the line polarization is available. Calculations for H-alpha line polarization by low-energy electron impact are presented, using the most sophisticated collision data available to date. The theoretical results compare well with polarization measurements dating from 1968. Low-energy electrons with anisotropic velocity distributions could be present in solar flares. They could be associated either with proton bombardment or with the existence of large temperature gradients. Assuming that the polarization of H-alpha observed in chromospheric flares is due only to electron impact, the ratio of the two even moments J2 and J0 of the electron velocity distribution is inferred. Further, under the hypothesis that the anisotropy is due to a high temperature gradient, a velocity distribution function for electrons carrying a conductive heat flux is linked to the observed polarization.

Aboudarham, J.; Berrington, K.; Callaway, J.; Feautrier, N.; Henoux, J. C.; Peach, G.; Saraph, H. E.

1992-08-01

93

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

CERN Document Server

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...

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

94

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

CERN Document Server

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...

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

95

A Spectroscopic Study of the H-alpha Surface Brightness Profiles in the Outer Disks of Galaxies  

CERN Document Server

The surface brightness profile of H-alpha emission in galaxies is generally thought to be confined by a sharp truncation, sometimes speculated to coincide with a star formation threshold. Over the past years, observational evidence for both old and young stellar populations, as well as individual H II regions, has demonstrated that the outer disk is an actively evolving part of a galaxy. To provide constraints on the origin of the aforementioned H-alpha truncation and the relation of H-alpha emission in the outer disk to the underlying stellar population, we measure the shape of the outer H-alpha surface brightness profile of 15 isolated, edge-on late-type disk galaxies using deep, long-slit spectroscopy. Tracing H-alpha emission up to 50% beyond the optical radius, R_25, we find a composite H-alpha surface brightness profile, well described by a broken-exponential law, that drops more steeply in the outer disk, but which is not truncated. The stellar continuum and H-alpha surface brightness both exhibit a br...

Christlein, Daniel; Bland-Hawthorn, Joss

2010-01-01

96

High time resolution observations of solar H-alpha flares - II. Search for signatures of electron beam heating  

OpenAIRE

Aims. The H-alpha emission of solar flare kernels and associated hard X-ray (HXR) emission often show similar time variations but their light curves are shifted in time by energy transfer mechanisms. We searched for fast radiative response of the chromosphere in the H-alpha line as a signature of electron beam heating. Methods. We investigate the time differences with sub-second resolution between the H-alpha line emission observed with a Multi-channel Subtractive Double Pas...

Radziszewski, K.; Rudawy, P.; Phillips, K. J. H.

2011-01-01

97

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

Directory of Open Access Journals (Sweden)

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.

Arbutina, B.

2009-12-01

98

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

OpenAIRE

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, f...

Schombert, James; Maciel, Tamela; Mcgaugh, Stacy

2011-01-01

99

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

CERN Document Server

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.

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

2009-01-01

100

Models of Diffuse H{\\alpha} in the Interstellar Medium: The Relative Contributions from In Situ Ionisation and Dust Scattering  

CERN Document Server

Using three dimensional Monte Carlo radiation transfer models of photoionisation and dust scattering, we explore different components of the widespread diffuse H$\\alpha$ emission observed in the interstellar medium of the Milky Way and other galaxies. We investigate the relative contributions of H$\\alpha$ from recombination emission in ionised gas and H$\\alpha$ that originates in H{\\sc ii} regions near the Galactic midplane and scatters off high altitude dust in the diffuse interstellar medium. For the radiation transfer simulations we consider two geometries for the interstellar medium: a three dimensional fractal geometry that reproduces the average density structure inferred for hydrogen in the Milky Way, and a density structure from a magneto hydrodynamic simulation of a supernovae driven turbulent interstellar medium. Although some sight lines that are close to H{\\sc ii} regions can be dominated by scattered light, overall we find that less than $\\sim 20\\%$ of the total H$\\alpha$ intensity in our simulat...

Barnes, Joanna E; Hill, Alex S; Haffner, L Matthew

2014-01-01

101

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

CERN Document Server

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

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

2011-01-01

102

High time resolution observations of solar H-alpha flares - II. Search for signatures of electron beam heating  

CERN Document Server

Aims. The H-alpha emission of solar flare kernels and associated hard X-ray (HXR) emission often show similar time variations but their light curves are shifted in time by energy transfer mechanisms. We searched for fast radiative response of the chromosphere in the H-alpha line as a signature of electron beam heating. Methods. We investigate the time differences with sub-second resolution between the H-alpha line emission observed with a Multi-channel Subtractive Double Pass (MSDP) spectrograph on the Large Coronagraph and Horizontal Telescope at Bialkow Observatory, Poland, and HXR emission recorded by the RHESSI spacecraft during several flares, greatly extending our earlier analysis (Paper I) to flares between 2003 and 2005. Results. For 16 H-alpha flaring kernels, observed in 12 solar flares, we made 72 measurements of time delays between local maxima of the RHESSI X-ray and H-alpha emissions. For most kernels, there is an excellent correlation between time variations in the H-alpha line emission (at lin...

Radziszewski, K; Phillips, K J H

2011-01-01

103

Orientation of the linear polarization plane of H-alpha emission in prominences  

CERN Document Server

2D distributions of deviations of the polarization plane from the direction tangential to the solar limb (angle \\chi) and the sign of \\chi are presented for H{\\alpha} prominences of March 29, 2006. The obtained values of \\chi are in agreement with non-eclipse coronagraphic measurements and indicate the existence of longitudinal magnetic fields. The 2D distributions of the sign of \\chi show the existence of both {\\guillemotleft}+{\\guillemotright} and {\\guillemotleft}-{\\guillemotright} polarities for each prominence. An interpretation in the frame of the existence of oppositely directed magnetic fields is noted.

Suyunova, E Z; Osokin, A R

2015-01-01

104

An unusual H-alpha nebula around RX J1856.5-3754  

OpenAIRE

We present spectroscopy and H alpha imaging of a faint nebula surrounding the X-ray bright, nearby neutron star RX J1856.5-3754. The nebula shows no strong lines other than the Hydrogen Balmer lines and has a cometary-like morphology, with the apex being approximately 1 arcsec ahead of the neutron star, and the tail extending up to at least 25 arcsec behind it. We find that the current observations can be satisfactorily accounted for by two different models. In the first, th...

Kerkwijk, M. H.; Kulkarni, S. R.

2001-01-01

105

The H-alpha stellar and interstellar emission in the open cluster NGC 6910  

OpenAIRE

We verify the nature of emission-line stars in the field of the open cluster NGC 6910. % Spectroscopy in the H-alpha region was obtained. Raw CCD frames of spectra of all stars fainter than V = 9 mag observed by us are significantly affected by nebular emission originating in the surrounding HII region IC 1318. After careful data reduction and subtraction of the nebular radiation we succeeded in obtaining reliable stellar spectra. We confirm that the star NGC 6910 37 is a Be...

Kubat, J.; Korcakova, D.; Kawka, A.; Pigulski, A.; Slechta, M.; Skoda, P.

2007-01-01

106

Connected tree-width  

OpenAIRE

The connected tree-width of a graph is the minimum width of a tree-decomposition whose parts induce connected subgraphs. Long cycles are examples of graphs that have small tree-width but large connected tree-width. We show that a graph has small connected tree-width if and only if it has small tree-width and contains no long geodesic cycle. We further prove a connected analogue of the duality theorem for tree-width: a finite graph has small connected tree-width if and only...

Diestel, Reinhard; Mu?ller, Malte

2012-01-01

107

H{\\alpha} to FUV ratios in resolved star forming region populations of nearby spiral galaxies  

CERN Document Server

We present a new study of H{\\alpha}/FUV flux ratios of star forming regions within a sample of nearby spiral galaxies. We search for evidence of the existence of a cluster mass dependent truncation in the underlying stellar initial mass function (IMF). We use an automated approach to identification of extended objects based on the SExtractor algorithm to catalogue resolved Hii regions within a set of nearby spiral galaxies. Corrections due to dust attenuation effects are applied to avoid artificially boosted H{\\alpha}/FUV values. We use the BPASS stellar population synthesis code of Eldridge & Stanway (2009) to create a benchmark population of star forming regions to act as a reference for our observations. Based on those models, we identify a zone of parameter space populated by regions that cannot be obtained with a cluster mass dependent truncation in the stellar IMF imposed. We find that the investigated galaxies display small subpopulations of star forming regions falling within our zone of interest,...

Hermanowicz, Maciej T; Eldridge, John J

2013-01-01

108

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

CERN Document Server

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 ...

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

109

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

CERN Document Server

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 ...

Bland-Hawthorn, J

1998-01-01

110

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

Science.gov (United States)

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

Canfield, Richard C.; Wulser, Jean-Pierre; Zarro, Dominic M.; Dennis, Brian R.

1991-01-01

111

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

Science.gov (United States)

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

Kucera, Therese A.; Landi, E.

2006-01-01

112

A Time-Series Analysis of the H-alpha Emission Line in V3885 Sagitarii  

CERN Document Server

Flickering is a phenomenon related to the mass accretion observed among many classes of astrophysical objects. In this paper we present a study of the flickering emission lines and continuum of the Cataclysmic Variable V3885 Sgr. The flickering behavior is first analyzed through statistical analysis and lightcurves power spectra. Autocorrelation techniques are then employed to estimate the flickering flares timescales. A cross correlation study between the line and its underlying continuum variability is presented. The cross correlation between the photometric and spectroscopic data is also discussed. The periodograms, calculated using emission line data, show a behavior that is similar to those obtained from photometric datasets found in the literature, with a plateau at lower frequencies and a power law at higher frequencies. The power law index is consistent with stochastic events. The cross-correlation study indicates the presence of a correlation between the variability on H-alpha and its underlying cont...

Ribeiro, Fabiola M A

2009-01-01

113

Light curve variations and H-alpha flaring of FK Comae  

International Nuclear Information System (INIS)

Multiband photoelectric observations reveal that the rapidly rotating giant FK Com's light curve is rapidly changing with respect to amplitude, shape, and light minimum phase. Analysis of the light curves indicates that these variations are due to rotational modulation by two large, subluminous regions on the star's surface, which appear to be about 800 + or - 150 K cooler than the star's photosphere. Flaring activity in the H-alpha emission is also noted, but there is no modulation of this emission with the 2.4-day photometric period or with any other period. This behavior is contrasted with the mechanisms suggested in the Walter and Basri (1982) model for the light variations. 28 references

114

Template RR Lyrae H alpha, H beta, and H gamma Velocity Curves  

CERN Document Server

We present template radial velocity curves of $ab$-type RR Lyrae stars constructed from high-precision measurements of ${\\rm H\\alpha}$, ${\\rm H\\beta}$, and ${\\rm H\\gamma}$ lines. Amplitude correlations between the Balmer line velocity curves, Johnson $V$-band, and SDSS $g$- and $r$-band light curves are also derived. Compared to previous methods, these templates and derived correlations reduce the uncertainty in measured systemic (center-of-mass) velocities of RR Lyrae stars by up to 15 {\\kms}, and will be of particular interest to wide-area spectroscopic surveys such as the Sloan Digital Sky Survey (SDSS) and LAMOST Experiment for Galactic Understanding and Exploration (LEGUE).

Sesar, Branimir

2012-01-01

115

STAR FORMATION IN THE OUTER DISKS OF SPIRAL GALAXIES: ULTRAVIOLET AND H{alpha} PHOTOMETRY  

Energy Technology Data Exchange (ETDEWEB)

We present an analysis of ultradeep UV and H{alpha} imaging of five nearby spiral galaxies to study the recent star formation in the outer disk. Using azimuthally averaged ellipse photometry as well as aperture photometry of individual young stellar complexes, we measure how star formation rates (SFRs) and UV and H{alpha} colors vary with radius. We detect azimuthally averaged UV flux to {approx}1.2-1.4 R{sub 25} in most galaxies; at the edge of the detected UV disk, the surface brightnesses are 28-29 mag arcsec{sup -2}, corresponding to SFR surface densities of {approx}3 Multiplication-Sign 10{sup -4} M{sub Sun} yr{sup -1} kpc{sup -2}. Additionally, we detect between 120 and 410 young stellar complexes per galaxy, with a significant number of detections out to {approx}1.5 R{sub 25}. We measure radial FUV-NUV profiles, and find that the dispersion in the UV colors of individual young stellar complexes increases with radius. We investigate how radial variations in the frequency of star formation episodes can create color gradients and increasing dispersion in the UV colors of star-forming regions, like those observed in our study. Specifically, we use recently published, high spatial and temporal resolution measurements of {Sigma}{sub SFR} throughout the disk of M33 to estimate the frequency of star formation episodes throughout the disk of a typical spiral galaxy. We use stellar synthesis models of these star formation histories (SFHs) to measure the variations in UV colors and find that we can replicate large dispersions in UV colors based on episodic SFHs.

Barnes, Kate L.; Van Zee, Liese [Department of Astronomy, Indiana University, Bloomington, IN 47405 (United States); Skillman, Evan D., E-mail: barneskl@astro.indiana.edu, E-mail: vanzee@astro.indiana.edu, E-mail: skillman@astro.umn.edu [Department of Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)

2011-12-20

116

High Resolution H alpha Images of the Binary Low-mass Proplyd LV 1 with the Magellan AO System  

CERN Document Server

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 ~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.

Wu, Y -L; Males, J R; Follette, K; Morzinski, K; Kopon, D; Rodigas, T J; Hinz, P; Puglisi, A; Esposito, S; Pinna, E; Riccardi, A; Xompero, M; Briguglio, R

2013-01-01

117

Newly Discovered Cataclysmic Variables from the INT/WFC Photometric H alpha Survey of the Northern Galactic Plane  

OpenAIRE

We report the discovery of 11 new cataclysmic variable (CV) candidates by the Isaac Newton Telescope (INT) Photometric H alpha Survey of the northern Galactic plane (IPHAS). Three of the systems have been the subject of further follow-up observations. For the CV candidates IPHAS J013031.90+622132.4 and IPHAS J051814.34+294113.2, time-resolved optical spectroscopy has been obtained and radial-velocity measurements of the H alpha emission-line have been used to estimate their ...

Witham, A. R.; Knigge, C.; Aungwerojwit, A.; Drew, J. E.; Gaensicke, B. T.; Greimel, R.; Groot, P. J.; Roelofs, G. H. A.; Steeghs, D.; Woudt, P. A.

2007-01-01

118

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

OpenAIRE

We present observations of the portion of the nearby spiral galaxy IC342 using narrow band [SII] and H$\\alpha$ filters. These observations were carried out in November 2011 with the 2m RCC telescope at Rozhen National Astronomical Observatory in Bulgaria. In this paper we report coordinates, diameters, H$\\alpha$ and [SII] fluxes for 203 HII regions detected in two fields of view in IC342 galaxy. The number of detected HII regions is 5 times higher than previously known in th...

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

2013-01-01

119

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

OpenAIRE

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 w...

Arbutina, B.; Ilic?, D.; Stavrev, K.; Uros?evic?, D.; Vukotic?, B.; Onic?, D.

2009-01-01

120

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

CERN Document Server

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

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

2013-01-01

121

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

International Nuclear Information System (INIS)

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

122

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

Science.gov (United States)

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

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

2014-07-01

123

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

Science.gov (United States)

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

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

2014-06-01

124

Dust-Corrected Star Formation Rates of Galaxies. I. Combinations of H-alpha and Infrared Tracers  

CERN Document Server

We combine H-alpha emission-line and infrared continuum measurements of two samples of nearby galaxies to derive dust attenuation-corrected star formation rates (SFRs). We use a simple energy balance based method that has been applied previously to HII regions in the Spitzer Infrared Nearby Galaxies Survey (SINGS), and extend the methodology to integrated measurements of galaxies. We find that our composite H-alpha+IR based SFRs are in excellent agreement with attenuation-corrected SFRs derived from integrated spectrophotometry, over the full range of SFRs (0.01 -- 80 solar mass per year) and attenuations (0 -- 2.5 mag) studied. We find that the combination of H-alpha and total infrared luminosities provides the most robust SFR measurements, but combinations of H-alpha measurements with monochromatic luminosities at 24 micron and 8 micron perform nearly as well. The calibrations differ significantly from those obtained for HII regions (Calzetti et al. 2007), with the difference attributable to a more evolved ...

Kennicutt, Robert C Jr; Calzetti, Daniela; Moustakas, John; Dale, Daniel A; Bendo, George; Engelbracht, Charles W; Johnson, Benjamin D; Lee, Janice C

2009-01-01

125

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

CERN Document Server

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

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

2004-01-01

126

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

CERN Document Server

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

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

2009-01-01

127

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

CERN Document Server

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...

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

2014-01-01

128

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

CERN Document Server

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...

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

129

Equivalent Lagrangians  

International Nuclear Information System (INIS)

We present a review of the inverse problem of the Calculus of Variations, emphasizing the ambiguities which appear due to the existence of equivalent Lagrangians for a given classical system. In particular, we analyze the properties of equivalent Lagrangians in the multidimensional case, we study the conditions for the existence of a variational principle for (second as well as first order) equations of motion and their solutions, we consider the inverse problem of the Calculus of Variations for singular systems, we state the ambiguities which emerge in the relationship between symmetries and conserved quantities in the case of equivalent Lagrangians, we discuss the problems which appear in trying to quantize classical systems which have different equivalent Lagrangians, we describe the situation which arises in the study of equivalent Lagrangians in field theory and finally, we present some unsolved problems and discussion topics related to the content of this article. (author)

130

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

CERN Document Server

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...

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

2013-01-01

131

The KPNO International Spectroscopic Survey. IV. H-alpha-selected Survey List 2  

CERN Document Server

The KPNO International Spectroscopic Survey (KISS) is an objective-prism survey for 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. Here we present the second list of emission-line galaxy 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 a 1.6-degree-wide strip located at Dec(1950) = 43d 30' and spans the RA range 11h 55m to 16h 15m. The survey strip runs through the center of the Bootes Void, and has enough depth to adequately sample the far side of the void. An area of 65.8 sq. deg. is covered. A total of 1029 candidate emission-line objects have been selected for inclusion in the survey list (15.6 per sq. deg.). We tabulate accurate coordinates and photometry for each source, as well as ...

Gronwall, C; Sarajedini, V L; Jangren, A; Chomiuk, L; Moody, J; Frattare, L; Boroson, T A

2004-01-01

132

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

CERN Document Server

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...

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

133

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

CERN Document Server

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

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

2014-01-01

134

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

CERN Document Server

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

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

2009-01-01

135

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2005-07-01

136

FUNDPAR: A program for Deriving Fundamental Parameters from Equivalent Widths  

Directory of Open Access Journals (Sweden)

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

C. Saffe

2011-01-01

137

MODELING THE EFFECTS OF STAR FORMATION HISTORIES ON H{alpha} AND ULTRAVIOLET FLUXES IN NEARBY DWARF GALAXIES  

Energy Technology Data Exchange (ETDEWEB)

We consider the effects of non-constant star formation histories (SFHs) on H{alpha} and GALEX far-ultraviolet (FUV) star formation rate (SFR) indicators. Under the assumption of a fully populated Chabrier initial mass function (IMF), we compare the distribution of H{alpha}-to-FUV flux ratios from {approx}1500 simple, periodic model SFHs with observations of 185 galaxies from the Spitzer Local Volume Legacy survey. We find a set of SFH models that are well matched to the data, such that more massive galaxies are best characterized by nearly constant SFHs, while low-mass systems experience burst amplitudes of {approx}30 (i.e., an increase in the SFR by a factor of 30 over the SFR during the inter-burst period), burst durations of tens of Myr, and periods of {approx}250 Myr; these SFHs are broadly consistent with the increased stochastic star formation expected in systems with lower SFRs. We analyze the predicted temporal evolution of galaxy stellar mass, R-band surface brightness, H{alpha}-derived SFR, and blue luminosity, and find that they provide a reasonable match to observed flux distributions. We find that our model SFHs are generally able to reproduce both the observed systematic decline and increased scatter in H{alpha}-to-FUV ratios toward low-mass systems, without invoking other physical mechanisms. We also compare our predictions with those from the Integrated Galactic IMF theory with a constant SFR. We find that while both predict a systematic decline in the observed ratios, only the time variable SFH models are capable of producing the observed population of low-mass galaxies (M{sub *} {approx}< 10{sup 7} M{sub Sun }) with normal H{alpha}-to-FUV ratios. These results demonstrate that a variable IMF alone has difficulty explaining the observed scatter in the H{alpha}-to-FUV ratios. We conclude by considering the limitations of the model SFHs and discuss the use of additional empirical constraints to improve future SFH modeling efforts.

Weisz, Daniel R.; Johnson, L. Clifton; Dalcanton, Julianne J.; Williams, Benjamin F. [Department of Astronomy, Box 351580, University of Washington, Seattle, WA 98195 (United States); and others

2012-01-01

138

The broad H-alpha, [O III] line wings in stellar supercluster A of NGC2363 and the turbulent mixing layer hypothesis  

CERN Document Server

Context. SuperclusterA in the extragalactic HII region NGC2363 is remarkable for the hypersonic gas seen as faint extended broad emission lines with a full width zero intensity of 7000km/s. Aims. We explore the possibility that the observed broad profiles are the result of the interaction of a high velocity cluster wind with dense photoionized clumps. Methods. The geometry considered is that of near static photoionized condensations at the surface of which turbulent mixing layers arise as a result of the interaction with the hot wind. The approximative treatment of turbulence is carried out using the mixing length approach of Canto & Raga. The code mappings Ic is used to derive the mean quantities describing the flow and to compute the line emissivities within the turbulent layers. The velocity projection in three dimensions of the line sources is carried out analytically. Results. A fast entraining wind of up to ~4300km/s appears to be required to reproduce the faint wings of the broad H-alpha and [O III...

Binette, Luc; Ubeda, Leonardo; Raga, Alejandro C; Robert, Carmelle; Krongold, Yair

2009-01-01

139

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

Energy Technology Data Exchange (ETDEWEB)

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.

Suarez, C.

1984-07-01

140

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

International Nuclear Information System (INIS)

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

141

New Hubble Space Telescope Observations of High-Velocity Ly(alpha) and H(alpha) in SNR 1987A  

Science.gov (United States)

We describe and model high-velocity (approximately 15,000 km S(exp -1)) Ly Alpha and H Alpha emission from the supernova remnant SNR 1987A seen in 1997 September and October with the Space Telescope Imaging Spectrograph. Part of this emission comes from a reverse shock located at approximately 75% of the radius of the inner boundary ofthe innercircumstellar ring and confined within + or - 30 degrees of the equatorial plane. Departure from axisymmetry in the Ly Alpha and H Alpha emission correlates with that seen in nonthermal radio emission and reveals an asymmetry in the circumstellar gas distribution. We also see diffuse high-velocity Ly-Alpha emission from supernova debris inside the reverse shock that may be due to excitation by nonthermal particles accelerated by the shock.

Michael, Eli; McCray, Richard; Pun, C. S. J.; Borkowski, Kazimierz; Garnavich, Peter; Challis, Peter; Kirshner, Robert P.; Chevalier, Roger; Filippenko, Alexei V.; Fransson, Claes; Panagia, Nino; Phillips, Mark; Schmidt, Brian; Suntzef, Nicholas

1998-01-01

142

Star Formation Triggering Mechanisms in Dwarf Galaxies: The Far-Ultraviolet, H-alpha, and HI Morphology of Holmberg II  

OpenAIRE

Far-UV (FUV), H-alpha, and HI observations of dwarf galaxy Holmberg II are used to trace the interaction between sites of massive star formation and the neutral and ionized components of the surrounding ISM. The data emphasize the importance of local conditions in regulating star formation from evidence such as massive stars inside ionized shells, compact HII regions surrounding aging clusters, and stars formed in chains of progressing age. Large-scale triggering by HI shell...

Stewart, S. G.; Fanelli, M. N.; Byrd, G. G.; Hill, J. K.; Westpfahl, D. J.; Cheng, K. P.; O Connell, R. W.; Roberts, M. S.; Neff, S. G.; Smith, A. M.; Stecher, T. P.

1999-01-01

143

Large-scale wind structures in OB supergiants: a search for rotationally modulated H\\alpha variability  

CERN Document Server

We present the results of a long-term monitoring campaign of the H\\alpha line in a sample of bright OB-supergiants (O7.5-B9) that aims at detecting rotationally modulated changes potentially related to the existence of large-scale wind structures. A total of 22 objects were monitor ed during 36 nights spread over 6 months in 2001-2002. Coordinated broad-band photometric observations were also obtained for some targets. Conspicuous evidence for variability in H\\alpha is found for the stars displaying a feature contaminated by wind emission. Most changes take place on a daily time-scale, although hourly variations are also occasionally detected. Convincing evidence for a cyclical pattern of variability in H\\alpha has been found in 2 stars: HD 14134 and HD 42087 (periodic signals are also detected in other stars, but independent confirmation is required). Rotational modulation is suggested from the similarity between the observed recurrence time-scales (in the range 13-25 days) and estimated periods of stellar r...

Morel, T; Pati, A K; Kuppuswamy, K; Carini, M T; Wood, E; Zimmerman, R

2004-01-01

144

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

CERN Document Server

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

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

2013-01-01

145

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

Energy Technology Data Exchange (ETDEWEB)

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}.

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

146

Bright OB stars in the Galaxy.II. Wind variability in O supergiants as traced by H-alpha  

CERN Document Server

We investigate the line-profile variability (lpv) of H-alpha for a large sample of O-type supergiants. We used the Temporal Variance Spectrum (TVS) analysis, developed by Fullerton et al 1996 and modified by us to take into account the effects of wind emission. By means of a comparative analysis we put a number of constraints on the properties of the variability as a function of stellar and wind parameters. The results of our analysis show that all the stars in the sample show evidence of significant lpv in H-alpha, mostly dominated by processes in the wind. The variations occur between zero and 0.3 v_inf (i.e., below ~1.5 R_star), in good agreement with the results from similar studies. A comparison between observations and line-profile simulations indicates that for stars with intermediate wind densities the H-alpha variability can be explained by simple models, consisting of coherent or broken shells (blobs) uniformly distributed over the wind volume, with an intrinsic scatter in the maximum density contra...

Markova, N; Scuderi, S; Markov, H

2005-01-01

147

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

CERN Document Server

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...

Schombert, James; McGaugh, Stacy

2011-01-01

148

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

CERN Document Server

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...

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

2010-01-01

149

Equivalent Fractions  

Science.gov (United States)

This interactive Java applet presents an array of common fractions sometimes referred to as a wall. Fractions less than one with denominators from 2 through 16 are placed to scale horizontally. The learner then moves a mouse to highlight equivalent sets of fractions vertically. Links to related topics are included.

2012-01-01

150

Evidence that [3H]-alpha,beta-methylene ATP may label an endothelial-derived cell line 5'-nucleotidase with high affinity.  

OpenAIRE

1. In membranes prepared from a permanent cell line of endothelial origin (WEC cells), [3H]-alpha, beta-methylene ATP ([3H]-alpha, beta-meATP) labelled high (pKd = 9.5; Bmax = 3.75 pmol mg-1 protein) and low (pKd = 7.2; Bmax = 23.3 pmol mg-1 protein) affinity binding sites. The high affinity [3H]-alpha, beta-meATP binding sites in the WEC cell membranes could be selectively labelled with a low concentration of the radioligand (1 nM). In competition studies performed at a radioligand concentra...

Michel, A. D.; Chau, N. M.; Fan, T. P.; Frost, E. E.; Humphrey, P. P.

1995-01-01

151

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2011-12-01

152

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

CERN Document Server

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

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

2011-01-01

153

Resonances and resonance widths  

International Nuclear Information System (INIS)

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

154

H$_{\\alpha}$ emission fluxes and lithium abundances of low mass stars in the young open cluster IC 4665  

CERN Document Server

As part of a long term effort to understand pre-main sequence Li burning, we have obtained high resolution spectroscopic observations of 14 late type stars (G0--M1) in the young open cluster IC~4665. Most of the stars have \\ha filled-in and \\li absorption, as expected for their young age. From the equivalent widths of \\ha emission excess (obtained using the spectral subtraction technique) and the \\lii feature, we have derived \\ha emission fluxes and photospheric Li abundances. The mean Li abundance of IC~4665 solar-type stars is log N(Li)=3.1; the same as in other young clusters (\\alpha~Per, Pleiades) and T Tauri stars. Our results support the conclusions from previous works that PMS Li depletion is very small for masses \\sim 1 \\msun . Among the IC 4665 late-G and early K-type stars, there is a spread in Li abundances of about one order of magnitude. The Li-poor IC~4665 members have low \\ha excess and vsin{\\it i}\\le10. Hence, the Li-activity-rotation connection which has been clearly established in the Pleiad...

Martín, E L

1996-01-01

155

Initial Data Release from the INT Photometric H-alpha Survey of the Northern Galactic Plane (IPHAS)  

CERN Document Server

The INT/WFC Photometric H-alpha Survey of the Northern Galactic Plane (IPHAS) is an imaging survey being carried out in H-alpha, r' and i' filters, with the Wide Field Camera (WFC) on the 2.5-metre Isaac Newton Telescope (INT) to a depth of r'=20 (10 sigma). The survey is aimed at revealing large scale structure in our local galaxy, and also the properties of key early and late populations making up the Milky Way. Mapping emission line objects enables a particular focus on objects in the young and old stages of stellar evolution ranging from early T-Tauri stars to late planetary nebulae. In this paper we present the IPHAS Initial Data Release, primarily a photometric catalogue of about 200 million unique objects, coupled with associated image data covering about 1600 square degrees in three passbands. We note how access to the primary data products has been implemented through use of standard virtual observatory publishing interfaces. Simple traditional web access is provided to the main IPHAS photometric cat...

González-Solares, E A; Greimel, R; Drew, J E; Irwin, M J; Sale, S E; Andrews, K; Aungwerojwit, A; Barlow, M J; Besselaar, E van den; Corradi, R L M; Gänsicke, B T; Groot, P J; Hales, A S; Hopewell, E C; Hu, H; Irwin, J; Knigge, C; Lagadec, E; Leisy, P; Lewis, J R; Mampaso, A; Matsuura, M; Moont, B; Morales-Rueda, L; Morris, R A H; Naylor, T; Parker, Q A; Prema, P; Pyrzas, S; Rixon, G T; Rodríguez-Gil, P; Roelofs, G; Sabin, L; Skillen, I; Suso, J; Tata, R; Viironen, K; Vink, J S; Witham, A; Wright, N J; Zijlstra, A A; Zurita, A; Drake, J; Fabregat, J; Lennon, D J; Lucas, P W; Martín, E L; Steeghs, D; Unruh, Y C

2007-01-01

156

Diatomic predissociation line widths  

Science.gov (United States)

Predissociation by rotation and curve crossing in diatomic molecules is discussed. The pattern of predissociation line widths is seen as providing a highly sensitive yardstick for the determination of unknown potential curves. In addition, the computation of such a pattern for given potential curves is considered a matter of routine, unless the predissociation happens to occur from an adiabatic potential curve. Analytic formulas are used to provide physical insight into the details of the predissociation pattern, to the extent that a direct inversion procedure is developed for determination of the repulsive potential curves for Type 1 predissociations.

Child, M. S.

1973-01-01

157

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

CERN Document Server

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

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

2002-01-01

158

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

International Nuclear Information System (INIS)

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

159

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

CERN Document Server

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.

Zhang, XueGuang

2015-01-01

160

Detection of an H-alpha Emission Line on a Quasar, RX J1759.4+6638, at z=4.3 with AKARI  

CERN Document Server

We report the detection of an H-alpha emission line in the low resolution spectrum of a quasar, RX J1759.4+6638, at a redshift of 4.3 with the InfraRed Camera (IRC) onboard the AKARI. This is the first spectroscopic detection of an H-alpha emission line in a quasar beyond z=4. The overall spectral energy distribution (SED) of RX J1759.4+6638 in the near- and mid-infrared wavelengths agrees with a median SED of the nearby quasars and the flux ratio of F(Ly-alpha)/F(H-alpha) is consistent with those of previous reports for lower-redshift quasars.

Oyabu, Shinki; Ohyama, Youichi; Matsuhara, Hideo; Takagi, Toshinobu; Nakagawa, Takao; Onaka, Takashi; Fujishiro, Naofumi; Ishihara, Daisuke; Ita, Yoshifusa; Kataza, Hirokazu; Kim, Woojung; Matsumoto, Toshio; Murakami, Hiroshi; Sakon, Itsuki; Tanabe, Toshihiko; Uemizu, Kazunori; Ueno, Munetaka; Usui, Fumihiko; Watarai, Hidenori; Haze, Kanae

2007-01-01

161

Virtual 5 mm-width multileaf collimation  

International Nuclear Information System (INIS)

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

162

Multiwavelength optical observations of chromospherically active binary systems; 1, Simultaneous $H{\\alpha}, NaI D_{1}, D_{2}$, and $HeI D_{3}$ observations  

CERN Document Server

This is the first paper of a series aimed at studying the chromosphere of active binary systems using the information provided for several optical spectroscopic features. Simultaneous H{alpha}, Na I D{1}, D{2}, and He I D{3} spectroscopic observations are reported here for 18 systems. The chromospheric contribution in these lines have been determined using the spectral subtraction technique. Very broad wings have been found in the subtracted H{alpha} profile of some of the more active stars. These profiles are well matched using a two-components Gaussian fit (narrow and broad) and the broad component could be interpreted as arising from microflaring. Prominence-like extended material have been detected in a near-eclipse H{alpha} observation of the system AR Lac. The excess emission found in the Na I D{1} and D{2} lines by application of the spectral subtraction technique and the behaviour of the H{alpha} line in the corresponding simultaneous observations indicate that the filling-in of the core of these line...

Montes, D; De Castro, E; Sanz-Forcada, J

1997-01-01

163

Discovery of an Apparent Nova in M81 and an Increase of H-alpha Emission from PNV J09553488+6910194  

Science.gov (United States)

We report the discovery of an apparent nova in M81 on a co-added 2000-s narrow-band H-alpha CCD image taken with the 2.5-m Isaac Newton Telescope (INT) + WFC at La Palma under ~1.5" seeing on 2014 Mar. ...

Hornoch, K.; Vaduvescu, O.; Stoev, H.

2014-03-01

164

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

Science.gov (United States)

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

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

2014-05-01

165

A search for clusters at high redshift - IV. Spectroscopy of H-alpha emitters in a proto-cluster at z=2.16  

CERN Document Server

Radio galaxy PKS 1138-262 is a massive galaxy at z=2.16, located in a dense environment. We have found an overdensity of Ly-alpha emitting galaxies in this field, consistent with a proto-cluster structure associated with the radio galaxy. Recently, we have discovered forty candidate H-alpha emitters by their excess near infrared narrow band flux. Here, we present infrared spectroscopy of nine of the brightest candidate H-alpha emitters. All these candidates show an emission line at the expected wavelength. The identification of three of these lines with H-alpha is confirmed by accompanying [NII] emission. The spectra of the other candidates are consistent with H-alpha emission at z~2.15, one being a QSO as indicated by the broadness of its emission line. The velocity dispersion of the emitters (360 km/s) is significantly smaller than that of the narrow band filter used for their selection (1600 km/s). We therefore conclude that the emitters are associated with the radio galaxy. The star formation rates (SFRs)...

Kurk, J D; Overzier, R A; Röttgering, H J A; Miley, G K

2004-01-01

166

The Wyoming Survey for H-alpha. III. A Multi-wavelength Look at Attenuation by Dust in Galaxies out to z~0.4  

CERN Document Server

We report results from the Wyoming Survey for H-alpha (WySH), a comprehensive four-square degree survey to probe the evolution of star-forming galaxies over the latter half of the age of the Universe. We have supplemented the H-alpha data from WySH with infrared data from the Spitzer Wide-area Infrared Extragalactic (SWIRE) Survey and ultraviolet data from the Galaxy Evolution Explorer (GALEX) Deep Imaging Survey. This dataset provides a multi-wavelength look at the evolution of the attenuation by dust, and here we compare a traditional measure of dust attenuation (L(TIR)/L(FUV)) to a diagnostic based on a recently-developed robust star formation rate (SFR) indicator, [H-alpha_obs+24-micron]/H-alpha_obs. With such data over multiple epochs, the evolution in the attenuation by dust with redshift can be assessed. We present results from the ELAIS-N1 and Lockman Hole regions at z~0.16, 0.24, 0.32 and 0.40. While the ensemble averages of both diagnostics are relatively constant from epoch to epoch, each epoch ind...

Moore, Carolynn A; Barlow, Rebecca J; Cohen, Seth A; Cook, David O; Johnson, L C; Kattner, ShiAnne M; Lee, Janice C; Staudaher, Shawn M

2010-01-01

167

Damping width of double resonances  

International Nuclear Information System (INIS)

Damping width of the double giant dipole resonance of 136Xe excited in relativistic heavy ion collisions is calculated by diagonalizing a microscopic Hamiltonian in a basis containing one-, two- and three-phonon states. The coupling between these states is determined making use of the fermion structure of the phonons. The resulting width of the double giant dipole resonance is close to ?(2) times the width of the single giant dipole resonance. (orig.)

168

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

CERN Document Server

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

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

2011-01-01

169

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

CERN Document Server

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

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

2012-01-01

170

CAIRNS: The Cluster And Infall Region Nearby Survey III. Environmental Dependence of H-alpha Properties of Galaxies  

CERN Document Server

We investigate the environmental dependence of star formation in cluster virial regions and infall regions as part of CAIRNS (Cluster And Infall Region Nearby Survey), a large spectroscopic survey of the infall regions surrounding nine nearby rich clusters of galaxies. Our long-slit spectroscopy yields estimates of star formation rates in environments from cluster cores to the general large-scale structure. The fraction of galaxies with current star formation in their inner disks as traced by H-alpha emission increases with distance from the cluster and converges to the ``field'' value only at 2-3 virial radii, in agreement with other investigations. However, among galaxies with significant current star formation (EW[Ha]geq2\\AA), there is no difference in the distribution of EW[Ha] inside and outside the virial radius. This surprising result, first seen by Carter et al., suggests that (1) star formation is truncated on either very short timescales or only at moderate and high redshifts or (2) that projection ...

Rines, K; Kurtz, M J; Diaferio, A; Rines, Kenneth; Geller, Margaret J.; Kurtz, Michael J.; Diaferio, Antonaldo

2005-01-01

171

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

CERN Document Server

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

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

2014-01-01

172

Phase width reduction project summary  

International Nuclear Information System (INIS)

The purpose of the phase width reduction project, 1993--96, was to reduce the phase width of the 88-Inch Cyclotron beam on target from 5--10 ns to 1--2 ns for certain experiments, such as Gammasphere, which use time-of-flight identification. Since reducing the phase width also reduces beam intensity, tuning should be done to also optimize the transmission. The Multi-turn Collimator slits in the cyclotron center region were used to collimate the early turns radially, thus reducing the phase width from about 5 ns to 1--2 ns FWHM for a Gammasphere beam. The effect of the slits on phase width was verified with a Fast Faraday Cup and with particle and gamma-ray detectors in the external beamline

173

Phase width reduction project summary  

Energy Technology Data Exchange (ETDEWEB)

The purpose of the phase width reduction project, 1993--96, was to reduce the phase width of the 88-Inch Cyclotron beam on target from 5--10 ns to 1--2 ns for certain experiments, such as Gammasphere, which use time-of-flight identification. Since reducing the phase width also reduces beam intensity, tuning should be done to also optimize the transmission. The Multi-turn Collimator slits in the cyclotron center region were used to collimate the early turns radially, thus reducing the phase width from about 5 ns to 1--2 ns FWHM for a Gammasphere beam. The effect of the slits on phase width was verified with a Fast Faraday Cup and with particle and gamma-ray detectors in the external beamline.

Clark, D.J.; Xie, Z.Q.; McMahan, M. A.

1999-11-01

174

A deterministic width function model  

Directory of Open Access Journals (Sweden)

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.

C. E. Puente

2003-01-01

175

Probabilistic Analysis of Crack Width  

Directory of Open Access Journals (Sweden)

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.

J. Marková

2000-01-01

176

On Tree-Partition-Width  

OpenAIRE

A \\emph{tree-partition} of a graph $G$ is a proper partition of its vertex set into `bags', such that identifying the vertices in each bag produces a forest. The \\emph{tree-partition-width} of $G$ is the minimum number of vertices in a bag in a tree-partition of $G$. An anonymous referee of the paper by Ding and Oporowski [\\emph{J. Graph Theory}, 1995] proved that every graph with tree-width $k\\geq3$ and maximum degree $\\Delta\\geq1$ has tree-partition-width at most $24k\\Delt...

Wood, David R.

2006-01-01

177

The width of a proof  

Directory of Open Access Journals (Sweden)

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

Gila Hanna

2014-09-01

178

A deterministic width function model  

OpenAIRE

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 natur...

Puente, C. E.

2003-01-01

179

Widths of magnetic twistor resonances  

International Nuclear Information System (INIS)

Evaluation of widths of magnetic twistor resonances, conditioned by long-wave torsion-type spherical nucleus oscillations is given within the framework of dissipative nuclear fluid-dynamics. It is assumed that dissipation of collective transverse oscillation energy is generated by nucleon-nucleon collisions leading finaly to nuclear Fermi-continuum viscosity. Analytic expressions for collision widths is given depending on the mass number, multipolarity and energy. 21 refs., 2 figs

180

H-alpha images of the Cygnus Loop - A new look at shock-wave dynamics in an old supernova remnant  

Science.gov (United States)

Attention is given to deep H-alpha images of portions of the east, west, and southwest limbs of the Cygnus Loop which illustrate several aspects of shock dynamics in a multiphase interstellar medium. An H-alpha image of the isolated eastern shocked cloud reveals cloud deformation and gas stripping along the cloud's edges, shock front diffraction and reflection around the rear of the cloud, and interior remnant emission due to upstream shock reflection. A faint Balmer-dominated filament is identified 30 arcmin further west of the remnant's bright line of western radiative filaments. This detection indicates a far more westerly intercloud shock front position than previously realized, and resolves the nature of the weak X-ray, optical, and nonthermal radio emission observed west of NGC 6960. Strongly curved Balmer-dominated filaments along the remnant's west and southwest edge may indicate shock diffraction caused by shock wave passage in between clouds.

Fesen, Robert A.; Kwitter, Karen B.; Downes, Ronald A.

1992-01-01

181

Chromospheric Ca II H and K and H-alpha emission in single and binary stars of spectral types F6-M2  

Science.gov (United States)

New observations of the Ca II H and K and H-epsilon region and/or the Balmer H-alpha line are presented for 100 mostly very active stars but also for weak or inactive stars with suspected activity. Correlations between chromospheric activity at Ca II H and K and H-alpha and effective surface temperature and rotation are identified, and several new stars with chromospheric Ca II H and K emission are discovered. No single activity-rotation relation can be derived for all luminosity classes, and there is clear evidence that evolved stars are generally more active than main-sequence stars of the same rotation period. Binary within the evolved stars appears to play no role, while main-sequence binary stars show generally higher levels of activity than their single counterparts. Chromospheric emission in the Ca II H and K lines depends on surface temperature in that flux declines with cooler temperature.

Strassmeier, Klaus G.; Fekel, Francis C.; Bopp, Bernard W.; Dempsey, Robert C.; Henry, Gregory W.

1990-01-01

182

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

OpenAIRE

In this article we introduce a technique for finding resonance radii in a disk galaxy. We use a two-dimensional velocity field in H{\\alpha} emission obtained with Fabry-Perot interferometry, derive the classical rotation curve, and subtract it off, leaving a residual velocity map. As the streaming motions should reverse sign at corotation, we detect these reversals, and plot them in a histogram against galactocentric radius, excluding points where the amplitude of the revers...

Font, Joan; Beckman, John E.; Epinat, Benoi?t; Fathi, Kambiz; Gutie?rrez, Leonel; Hernandez, Olivier

2011-01-01

183

Variation in quadrupole couplings of alpha deuterons in ubiquitin suggests the presence of C(alpha)-H(alpha)...O=C hydrogen bonds.  

Science.gov (United States)

Nuclear quadrupolar couplings are sensitive probes of hydrogen bonding. Experimental quadrupolar coupling constants of alpha deuterons (D(alpha) QCC) are reported for the residues of human ubiquitin that do not experience large-amplitude internal dynamics on the pico- to nanosecond time scale. Two different methods for D(alpha) QCC estimation are employed: (i) direct estimation of D(alpha) QCC values from R(1) and R(2) (2)H D(alpha) rates using the dynamics parameters (S(C(alpha)-H(alpha))(2)) derived from 1 micros molecular dynamics simulations as well as from (13)C(alpha) relaxation measurements and (ii) indirect measurements via scalar relaxation of the second kind that affects (13)C(alpha) relaxation rates in (13)C(alpha)-D(alpha) spin systems. A relatively large variability of D(alpha) QCC values is produced by both methods. The average value of 170.6 +/- 3 kHz is derived from the combined data set, with D(alpha) QCC values ranging from 159.2 to 177.2 kHz. The set of lowest quadrupolar couplings in all data sets corresponds to the residues that are likely to form weak C(alpha)-H(alpha)...O=C hydrogen bonds as predicted from the analysis of short H(alpha)...O distances in three-dimensional structures of ubiquitin. These D(alpha) nuclei show up to 10 kHz reduction in their QCC values, which is in agreement with earlier solid-state NMR measurements in alpha deuterons of glycine. A statistically significant correlation is observed between the QCC values of alpha-deuterons and the inverse cube of C(alpha)-H(alpha)...O=C distances in ubiquitin. PMID:20476744

Sheppard, Devon; Li, Da-Wei; Godoy-Ruiz, Raquel; Brüschweiler, Rafael; Tugarinov, Vitali

2010-06-01

184

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

CERN Document Server

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

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

2007-01-01

185

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

CERN Document Server

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

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

2004-01-01

186

Width and structure of ? hypernuclei  

International Nuclear Information System (INIS)

The width of ? single-particle states in nuclei, due to the ?N??N conversion, is estimated from the optical-model expression GAMMA = ??sub(c)rho. A link between this expression and the underlying meson-exchange description of the conversion process is established. The estimated widths are not small. It is shown that the selectivity of the low-energy conversion to the spin and isospin of the ?N pair leads to substantial reduction of these widths for some ? hypernuclear states, coherently excited in (K-,?) low momentum transfer reactions on light nuclei, to a level below 10 MeV. Such states have probably been observed in 7Li, 9Be and 12C and their structure is here discussed. It is pointed out that whether or not sub(SIGMA)16Osup(*) exhibits prominent peak structure depends strongly on the strength of the ? on-body spin-orbit nuclear potential. (author)

187

Equivalence principles and electromagnetism  

Science.gov (United States)

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.

Ni, W.-T.

1977-01-01

188

Identifying Equivalent Fractions  

Science.gov (United States)

This site helps students understand how to identify equivalent fractions by explaining what equivalent fractions are and how to compare two fractions to see if they are equivalent. There is also a list of fractions equivalent to 1/2, 1/3, 1/4, 1/5, and 2/5 so students can begin to see the pattern that emerges. Finally, the site presents an interactive game in which students can practice by naming the equivalent fraction to a given fraction.

2010-07-02

189

Comparing fixed and variable-width Gaussian networks.  

Science.gov (United States)

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

K?rková, V?ra; Kainen, Paul C

2014-09-01

190

Hybrid Exotic Meson Decay Width  

CERN Document Server

We present results of a decay width calculation for a hybrid exotic meson(h, JPC=1-+) in the decay channel h to pi+a1. This calculation uses quenched lattice QCD and Luescher's finite box method. Operators for the h and pi+a1 states are used in a correlation matrix which was expanded by varying the smearing and fuzzing levels at source and sink points. Scattering phase shifts for a discrete set of relative pi+a1 momenta are determined using eigenvalues of the correlation matrix and formulae derived by Luescher. The phase shift data is very sparse, but fits to a Breit-Wigner model are made, resulting in a decay width of about 80 MeV.

Cook, M S

2005-01-01

191

Widths of isovector monopole resonances  

International Nuclear Information System (INIS)

The widths of the isovector monopole ?Tsub(z) = 1 component in 208Tl, 140La, 120In and 90Y are evaluated within the self-consistent Hartree-Fock + charge-exchange RPA using the Skyrme interaction. The coupling of 1p-1h states to 2p-2h configurations is microscopically calculated. The results are compared with those of recent pion charge-exchange reactions. (author)

192

Two Photon Width of ?c  

International Nuclear Information System (INIS)

We discuss the measured partial width of the pseudoscalar charmonium state, ?c , into two photons. Predictions from potential models are examined and compared with experimental values. Including radiative corrections, it is found that present measurements are compatible both with a QCD type potential and with a static Coulomb potential, with ?s evaluated at two loops. Results are also compared with those from J/? data through the NRQCD model. (author)

193

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

OpenAIRE

We present the spatially resolved H-alpha (Ha) dynamics of sixteen star-forming galaxies at z~0.81 using the new KMOS multi-object integral field spectrograph on the ESO VLT. These galaxies were selected using 1.18 um narrow-band imaging from the 10 deg^2 CFHT-HiZELS survey of the SA22hr field, are found in a ~4Mpc over-density of Ha emitters and likely reside in a group/intermediate environment, but not a cluster. We confirm and identify a rich group of star-forming galaxie...

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

2013-01-01

194

Equivalent Fractions Finder  

Science.gov (United States)

This activity allows students to visually experiment with the relationship between the values of equivalent fractions and areas within a square or a circle. The activity provides the user with a fraction, its equivalent representation as a shaded portion of a square or circle, and a number line. Also displayed are two empty squares or circles. The user can add and color sections to the blank shapes to create a fraction equivalent to the computer generated fraction.

2007-12-12

195

On the operator equivalents  

International Nuclear Information System (INIS)

A closed polynomial formula for the qth component of the diagonal operator equivalent of order k is derived in terms of angular momentum operators. The interest in various fields of molecular and solid state physics of using such a formula in connection with symmetry adapted operator equivalents is outlined

196

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

CERN Document Server

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...

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

197

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

CERN Document Server

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...

Hao, Qi; Chen, P F

2013-01-01

198

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

CERN Document Server

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

Wang, Wei-Hao; Prochaska, J Xavier

2015-01-01

199

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

CERN Document Server

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

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

2013-01-01

200

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

CERN Document Server

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

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

2013-01-01

201

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

CERN Document Server

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...

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

2012-01-01

202

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

CERN Document Server

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

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

2014-01-01

203

Nonequivalence of equivalence principles  

Science.gov (United States)

Equivalence principles played a central role in the development of general relativity. Furthermore, they have provided operative procedures for testing the validity of general relativity, or constraining competing theories of gravitation. This has led to a flourishing of different, and inequivalent, formulations of these principles, with the undesired consequence that often the same name, "equivalence principle," is associated with statements having a quite different physical meaning. In this paper, we provide a precise formulation of the several incarnations of the equivalence principle, clarifying their uses and reciprocal relations. We also discuss their possible role as selecting principles in the design and classification of viable theories of gravitation.

Di Casola, Eolo; Liberati, Stefano; Sonego, Sebastiano

2015-01-01

204

Topics in orbit equivalence  

CERN Document Server

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

Kechris, Alexander S

2004-01-01

205

Migraine equivalents in childhood.  

Science.gov (United States)

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

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

2014-10-01

206

Weak arithmetic equivalence  

OpenAIRE

Inspired by the invariant of a number field given by its zeta function, we define the notion of {\\it weak arithmetic equivalence}, and show that under certain ramification hypothesis, this equivalence determines the local root numbers of the number field. This is analogous to a result of Rohrlich on the local root numbers of a rational elliptic curve. Additionally, we prove that for tame non-totally real number fields, the integral trace form is invariant under weak arithmet...

Mantilla-soler, Guillermo

2013-01-01

207

Exact calculation of alpha decay widths by the two body model and comparison with experimental widths  

International Nuclear Information System (INIS)

The alpha decay widths are computed exactly using two body model. The computed and experimental widths are compared and a very satisfactory agreement is obtained in both the absolute values and the dispersion of the widths

208

Palindromic width of free nilpotent groups  

OpenAIRE

In this paper we consider the palindromic width of free nilpotent groups. In particular, we prove that the palindromic width of a finitely generated free nilpotent group is finite. We also prove that the palindromic width of a free abelian-by-nilpotent group is finite.

Bardakov, Valeriy G.; Gongopadhyay, Krishnendu

2013-01-01

209

Equivalence Testing Mobile Apps  

Directory of Open Access Journals (Sweden)

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

Denzler Christoph

2012-01-01

210

Orbifold equivalent potentials  

CERN Document Server

To a graded finite-rank matrix factorisation of the difference of two homogeneous potentials one can assign two numbers, the left and right quantum dimension. The existence of such a matrix factorisation with non-zero quantum dimensions defines an equivalence relation between potentials, giving rise to non-obvious equivalences of categories. Restricted to ADE singularities, the resulting equivalence classes of potentials are those of type {A_{d-1}} for d odd, {A_{d-1},D_{d/2+1}} for d even but not in {12,18,30}, and {A_{11}, D_7, E_6}, {A_{17}, D_{10}, E_7} and {A_{29}, D_{16}, E_8}. This is the result expected from two-dimensional rational conformal field theory, and it directly leads to new descriptions of and relations between the associated (derived) categories of matrix factorisations and Dynkin quiver representations.

Carqueville, Nils; Runkel, Ingo

2013-01-01

211

DAG-width is PSPACE-complete  

OpenAIRE

Berwanger et al. show that for every graph $G$ of size $n$ and DAG-width $k$ there is a DAG decomposition of width $k$ and size $n^{O(k)}$. This gives a polynomial time algorithm for determining the DAG-width of a graph for any fixed $k$. However, if the DAG-width of the graphs from a class is not bounded, such algorithms become exponential. This raises the question whether we can always find a DAG decomposition of size polynomial in $n$ as it is the case for tree width and ...

Amiri, Saeed Akhoondian; Kreutzer, Stephan; Rabinovich, Roman

2014-01-01

212

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  

OpenAIRE

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

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

2007-01-01

213

Spreading width of giant resonances and the attenuation of zero sound  

International Nuclear Information System (INIS)

It is shown that the RPA plus perturbation approach which is commonly used to calculate microscopically the spreading width of Giant Resonances is equivalent to Landau's suggestion that the damping width of zero sound at temperature T=O can be obtained by multiplying the classical collision result with an energy ?- and T-dependent correction factor [1+(?/2?kT)2] with T->O. (orig.)

214

Radioactive waste equivalence  

International Nuclear Information System (INIS)

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

215

Correspondences. Equivalence relations  

International Nuclear Information System (INIS)

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

216

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

Science.gov (United States)

Context. Cluster galaxies are the ideal sites to look at when studying the influence of the environment on the various aspects of the evolution of galaxies, such as the changes in their stellar content and morphological transformations. In the framework of wings, the WIde-field Nearby Galaxy-cluster Survey, we have obtained optical spectra for ~6000 galaxies selected in fields centred on 48 local (0.04 noise ratio. This way, we can derive a spectral classification reflecting the stellar content, based on the presence and strength of the [Oii] and H? lines. Results: After a quality check, we are able to measure 4381 of the ~6000 originally observed spectra in the fields of 48 clusters, of which 2744 are spectroscopically confirmed cluster members. The spectral classification is then analysed as a function of galaxies' luminosity, stellar mass, morphology, local density, and host cluster's global properties and compared to higher redshift samples (MORPHS and EDisCS). The vast majority of galaxies in the local clusters population are passive objects, being also the most luminous and massive. At a magnitude limit of MV quenching efficiency in clusters at redshifts in the 0 to ~1 range. Furthermore, more important than the global environment, the local density seems to be the main driver of galaxy evolution in local clusters at least with respect to their stellar populations content. Based on observations taken at the Anglo Australian Telescope (3.9 m- AAT) and at the William Herschel Telescope (4.2 m-WHT).Full Table A.1 is available in electronic form at both the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/566/A32 and by querying the wings database at http://web.oapd.inaf.it/wings/new/index.htmlAppendices are available in electronic form at http://www.aanda.org

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

2014-06-01

217

VizieR Online Data Catalog: Equivalent widths of 6 NGC5694 stars (Mucciarelli+, 2013)  

Science.gov (United States)

The data have been acquired with the FLAMES@VLT spectrograph in the combined MEDUSA+UVES mode, allowing the simultaneous allocation of eight UVES high-resolution fibres (discussed in this paper) and 132 MEDUSA mid-resolution fibres (discussed in a forthcoming paper, mainly devoted to the internal kinematics of the cluster). The employed spectral configuration for the UVES targets discussed in this paper is the 580 Red Arm, with a spectral resolution of ~40000 and covering the range ~4800-6800Å. A total of eight exposures of 46min each for the same targets configuration has been secured in Service Mode during the period between 2012 April and July. (2 data files).

Mucciarelli, A.; Bellazzini, M.; Catelan, M.; Dalessandro, E.; Amigo, P.; Correnti, M.; Cortes, C.; D'Orazi, V.

2014-10-01

218

Red cell distribution width and nonalcoholic steatohepatitis  

OpenAIRE

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

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

2014-01-01

219

The equivalence theorem  

International Nuclear Information System (INIS)

The equivalence theorem states that, at an energy E much larger than the vector-boson mass M, the leading order of the amplitude with longitudinally polarized vector bosons on mass shell is given by the amplitude in which these vector bosons are replaced by the corresponding Higgs ghosts. We prove the equivalence theorem and show its validity in every order in perturbation theory. We first derive the renormalized Ward identities by using the diagrammatic method. Only the Feynman-- 't Hooft gauge is discussed. The last step of the proof includes the power-counting method evaluated in the large-Higgs-boson-mass limit, needed to estimate the leading energy behavior of the amplitudes involved. We derive expressions for the amplitudes involving longitudinally polarized vector bosons for all orders in perturbation theory. The fermion mass has not been neglected and everything is evaluated in the region mf?M much-lt E much-lt mHiggs

220

Quantum Equivalence Principle  

CERN Document Server

A simple mapping procedure is presented by which classical orbits and path integrals for the motion of a point particle in flat space can be transformed directly into those in curved space with torsion. Our procedure evolved from well-established methods in the theory of plastic deformations, where crystals with defects are described mathematically as images of ideal crystals under active nonholonomic coordinate transformations. Our mapping procedure may be viewed as a natural extension of Einstein's famous equivalence principle. When applied to time-sliced path integrals, it gives rise to a new quantum equivalence principle which determines short-time action and measure of fluctuating orbits in spaces with curvature and torsion. The nonholonomic transformations possesses a nontrivial Jacobian in the path measure which produces in a curved space an additional term proportional to the curvature scalar R, thus canceling a similar term found earlier by DeWitt. This cancelation is important for correctly describi...

Kleinert, H

1996-01-01

221

A Window Width Optimized S-Transform  

OpenAIRE

Energy concentration of the S-transform in the time-frequency domain has been addressed in this paper by optimizing the width of the window function used. A new scheme is developed and referred to as a window width optimized S-transform. Two optimization schemes have been proposed, one for a constant window width, the other for time-varying window width. The former is intended for signals with constant or slowly varying frequencies, while the latter can d...

Jin Jiang; Igor Djurovi?; Ervin Sejdi?

2008-01-01

222

The width of 5-dimensional prismatoids  

CERN Document Server

Santos' construction of counter-examples to the Hirsch conjecture is based on the existence of prismatoids of dimension d of width greater than d. The case d=5 being the smallest one in which this can possibly occur, we here study the width of 5-dimensional prismatoids, obtaining the following results: - There are 5-prismatoids of width six with only 25 vertices, versus the 48 vertices in Santos' original construction. This leads to lowering the dimension of the non-Hirsch polytopes from 43 to only 20. - There are 5-prismatoids with n vertices and width \\Omega(n^(1/2)) for arbitrarily large n.

Matschke, Benjamin; Weibel, Christophe

2012-01-01

223

Statistical properties of H-alpha and HXR flares in the cycle 23 in relation to sunspots and active regions detected from the Solar Feature Catalogues  

Science.gov (United States)

The statistical properties of H-alpha and hard X-ray solar flares are investigated in relation to the cycle variations in 1996-2006 of sunspots and active regions (plages) obtained from the automated Soar Feature Catalogues (SFC, http://solar.inf.brad.ac.uk). Cross-correlation analysis is carried out between flare sizes, locations, significance and active region/sunspot parameters including magnetic field extracted in SFC. Sunspot and plage area distributions reveals a strong North-South asymmetry of about 0.2 and the period of about 7-8 years for sunspots and of 0.5 and period of 9 years for plages with both asymmetries decreasing towards the next cycle minimum. The temporal distribution of solar flare occurrences in Northern and Southern hemispheres, at different latitudes and longitudes are compared with those of plage and sunspot areas and LOS magnetic fields. The spectral indices of HXR and gamma-ray emission wer used to estimate magnetic field components and their variations with the cycle. The application of these results to the solar activity forecast is discussed.

Zharkova, V.; Zharkov, S.

2006-12-01

224

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

CERN Document Server

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

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

2013-01-01

225

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

CERN Document Server

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...

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

2007-01-01

226

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

CERN Document Server

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

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

2007-01-01

227

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

CERN Document Server

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

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

2011-01-01

228

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

International Nuclear Information System (INIS)

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

229

Direct measurement of the W boson width  

International Nuclear Information System (INIS)

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

230

Upper Limits on the Higgs Width  

CERN Document Server

Slides for BSM-HW@LPC on: Direct and indirect measurements of the Higgs boson width from ATLAS and CMS. Direct limits on the Higgs boson width are approximately $<2.4$ GeV and indirect limits using the combination of on- and off-shell measurements are approximately $<5\\cdot$ SM expectation.

Long, Jonathan; The ATLAS collaboration

2014-01-01

231

Neural Networks with Finite Width Action Potentials  

CERN Document Server

The significance of having finite widths of action potentials in integrate and fire neural networks is investigated. Models suggested by Hopfield and Herz [1] with zero action potential has been generalized to include pulse shapes of arbitrary widths and shapes. The convergence to limit cycle is examined both analytically and in simulation experiments. Hopfield's proof for nonleaking models has been extended nontrivially to the case of finite widths. It is pointed out that the concept of simultaneity in such networks maybe subject to bin widths in simulation experiments. The effects of varying the shape of the action potential and its width are examined. The roles of the magnitude of a leaking resistance connected to the neurons, a common external current and synaptic currents between neighbors are also examined and found to bear important consequences to the dynamical development of the network.

Shafee, F

2001-01-01

232

Comments on TNT Equivalence  

Energy Technology Data Exchange (ETDEWEB)

The term ``TNT Equivalence`` is used throughout the explosives and related industries to compare the effects of the output of a given explosive to that of TNT. This is done for technical design reasons in scaling calculation such as for the prediction of blast waves, craters, and structural response, and is also used as a basis for government regulations controlling the shipping, handling and storage of explosive materials, as well as for the siting and design of explosive facilities. TNT equivalence is determined experimentally by several different types of tests, the most common of which include: plate dent, ballistic mortar, trauzl, sand crush, and air blast. All of these tests do not necessarily measure the same output property of the sample explosive. As examples of this, some tests depend simply upon the CJ pressure, some depend upon the PV work in the CJ zone and in the Taylor wave behind the CJ plane, some are functions of the total work which includes that from secondary combustion in the air mixing region of the fireball and are acutely effected by the shape of the pressure-time profile of the wave. Some of the tests incorporate systematic errors which are not readily apparent, and which have a profound effect upon skewing the resultant data. Further, some of the tests produce different TNT Equivalents for the same explosive which are a function of the conditions at which the test is run. This paper describes the various tests used, discusses the results of each test and makes detailed commentary on what the test is actually measuring, how the results may be interpreted, and if and how these results can be predicted by first principals based calculations. Extensive data bases are referred to throughout the paper and used in examples for each point in the commentaries.

Cooper, P.W.

1994-07-01

233

Equivalences of coisotropic submanifolds  

DEFF Research Database (Denmark)

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

Schaetz, Florian; Zambon, Marco

2014-01-01

234

Equivalence Principle in Cosmology  

CERN Document Server

We analyse the Einstein equivalence principle (EEP) for a Hubble observer in Friedmann-Lemaitre-Robertson-Walker spacetime. We show that the affine structure of light cone in the FLRW spacetime should be treated locally in terms of the optical metric which is not reduced to the Minkowski metric due to the non-uniform parametrization of the local equations of light propagation with the proper time of the observer's clock. The physical consequence of this difference is that the Doppler shift of radio waves measured locally, is affected by the Hubble expansion.

Kopeikin, Sergei

2013-01-01

235

Equivalence of Dual Graphs  

Directory of Open Access Journals (Sweden)

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

M. Azram

2013-07-01

236

On the holographic width of flux tubes  

CERN Document Server

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

Giataganas, Dimitrios

2015-01-01

237

Thermal width of quarkonium from holography  

Energy Technology Data Exchange (ETDEWEB)

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

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

2014-04-15

238

Testing statistical hypotheses of equivalence  

CERN Document Server

The statistical concept of equivalence has gained considerable importance since the 1980s, with applications in medical & biopharmaceutical research. This book gives an account of equivalence assessment through statistical testing procedures.

Wellek, Stefan

2002-01-01

239

Stuttering Equivalence for Parity Games  

CERN Document Server

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

Cranen, Sjoerd; Willemse, Tim A C

2011-01-01

240

Establishing Substantial Equivalence: Proteomics  

Science.gov (United States)

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.

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

241

Free products, Orbit Equivalence and Measure Equivalence Rigidity  

CERN Document Server

We study the analogue in orbit equivalence of free product decomposition and free indecomposability for countable groups. We introduce the (orbit equivalence invariant) notion of freely indecomposable ({\\FI}) standard probability measure preserving equivalence relations and establish a criterion to check it, namely non-hyperfiniteness and vanishing of the first $L^2$-Betti number. We obtain Bass-Serre rigidity results, \\textit{i.e.} forms of uniqueness in free product decompositions of equivalence relations with ({\\FI}) components. The main features of our work are weak algebraic assumptions and no ergodicity hypothesis for the components. We deduce, for instance, that a measure equivalence between two free products of non-amenable groups with vanishing first $\\ell^2$-Betti numbers is induced by measure equivalences of the components. We also deduce new classification results in Orbit Equivalence and II$_1$ factors.

Alvarez, Aurélien

2008-01-01

242

7 CFR 29.1085 - Width.  

Science.gov (United States)

...COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Official Standard Grades for Flue-Cured...expressed in relation to its length. Width, as an element... Stringy Narrow Normal Spready Length...

2010-01-01

243

The widths of magnetic twist modes  

International Nuclear Information System (INIS)

Within the dissipative nuclear fluid-dynamics the predictions are presented for the widths of magnetic twist resonances associated with the long wavelength torsion like vibrations of a spherical nucleus. 25 refs.; 2 figs.; 1 tab

244

Curves of Constant Width and Reuleaux Polygons  

Science.gov (United States)

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

245

Width of Rough Interfaces on Asymmetric Lattices  

OpenAIRE

I present a calculation of the interfacial width within the capillary wave (Gaussian) approximation. The calculation is done on rectangular lattices of size L_1 times L_2, with periodic boundary conditions.

Pinn, K.

1999-01-01

246

Evolution of GDR width with angular momentum  

International Nuclear Information System (INIS)

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

247

Rho decay width from the lattice  

CERN Document Server

While the masses of light hadrons have been extensively studied in lattice QCD simulations, there exist only a few exploratory calculations of the strong decay widths of hadronic resonances. We will present preliminary results of a computation of the rho meson width obtained using $N_f=2+1$ flavor simulations. The work is based on L\\"uscher's formalism and its extension to moving frames.

Frison, J; Fodor, Z; Hoelbling, C; Katz, S D; Krieg, S; Kurth, T; Lellouch, L; Lippert, T; Portelli, A; Ramos, A; Szabo, K K

2010-01-01

248

Neutron beam compressors for pulse width reduction  

International Nuclear Information System (INIS)

In the context of intensity and resolution optimization of a neutron time-of-flight spectrometer several methods of beam width reduction at the chopper are considered aiming at a reduction of the neutron pulse width at minimum loss of intensity. The most advantageous technique discussed uses a double-trumpet arrangement in which the chopper is placed in between converging and diverging neutron guide sections. 7 refs., 1 fig

249

Neutron beam compressors for pulse width reduction  

International Nuclear Information System (INIS)

In the context of intensity and resolution optimization of a neutron time-of-flight spectrometer several methods of beam width reduction at the chopper are considered aiming at a reduction of the neutron pulse width at minimum loss of intensity. The most advantageous technique discussed uses a ''double-trumpet'' arrangement in which the chopper is placed between converging and diverging neutron guide sections. (author)

250

H-atom laser without inversion (LWI) in space: a possible explanation for the intense, narrow-band, H(alpha) emission frequently observed in reddened early-type stars  

OpenAIRE

A model is suggested to explain the frequently observed presence of intense, narrow-band, H(alpha) emission lines in the optical spectra of reddened, early-type stars (e.g. HD 44179, IRAS 18179-1346, IRAS 20298+4011). It is proposed that hydrogen atoms surrounding compact H II regions enveloping such stars become coherently phased via a nonlinear photonic mechanism that leads to `electromagnetically induced transparency (EIT)'. EIT is a powerful technique that can be used to...

Sorokin, P. P.; Glownia, J. H.

2001-01-01

251

Appropriate energy window width for gamma camera  

Directory of Open Access Journals (Sweden)

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

Jabbari N

2004-06-01

252

Improved V-shaped microcantilever width profile for sensing applications  

International Nuclear Information System (INIS)

In this work we have proposed an improvement in the shape of the V-shaped microcantilever by varying the width profile. In this paper we have studied the variation of resonant frequency as a function of changes in profile determined by the length of the microcantilever, keeping constant the active area for binding. It is observed that for the optimized nonlinear profile the angle at the tip is 91.410, more than twice the angle at the tip of the linear profile cantilever. The variation of the equivalent spring constant with changes in the profile is also studied. It is proposed that the optimum nonlinear profile cantilever has a spring constant of ?0.39 ?N ?m-1. The resonant frequency is obtained by using the Rayleigh-Ritz method, the deflection model and the SUGAR simulator. The results are compared and an improvement in the performance of the cantilever is observed.

253

Line width of Josephson flux flow oscillators  

DEFF Research Database (Denmark)

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

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

2002-01-01

254

Biomonitoring Equivalents for selenium.  

Science.gov (United States)

Selenium is an essential nutrient for human health with a narrow range between essentiality and toxicity. Selenium is incorporated into several proteins that perform important functions in the body. With insufficient selenium intake, the most notable effect is Keshan disease, an endemic cardiomyopathy in children. Conversely, excessive selenium intake can result in selenosis, manifested as brittle nails and hair and gastro-intestinal disorders. As such, guidance values have been established to protect against both insufficient and excessive selenium exposures. Dietary Reference Intakes (DRIs) have been established as standard reference values for nutritional adequacy in North America. To protect against selenosis resulting from exposure to excessive amounts of selenium, several government and non-governmental agencies have established a range of guidance values. Exposure to selenium is primarily through the diet, but monitoring selenium intake is difficult. Biomonitoring is a useful means of assessing and monitoring selenium status for both insufficient and excessive exposures. However, to be able to interpret selenium biomonitoring data, levels associated with both DRIs and toxicity guidance values are required. Biomonitoring Equivalents (BEs) were developed for selenium in whole blood, plasma and urine. The BEs associated with assuring adequate selenium intake (Estimated Average Requirements - EAR) are 100, 80 and 10?g/L in whole blood, plasma and urine, respectively. The BEs associated with protection against selenosis range from 400 to 480?g/L in whole blood, 180-230?g/L in plasma, and 90-110?g/L in urine. These BE values can be used by both regulatory agencies and public health officials to interpret selenium biomonitoring data in a health risk context. PMID:25068883

Hays, Sean M; Macey, Kristin; Nong, Andy; Aylward, Lesa L

2014-10-01

255

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

International Nuclear Information System (INIS)

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

256

Constraints on widths of mixed pentaquark multiplets  

CERN Document Server

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.

Mohta, V

2004-01-01

257

Device equivalence in integrated optics  

OpenAIRE

The concept of device equivalence is introduced. In equivalent devices, the light propagation can be described by identically evolving modal expansions, resulting in identical power transfer ratios. By first applying this concept to a z-invariant structure with a low refractive-index contrast it is shown how a normalized coordinate space can be defined in which equivalent structures have exactly the same geometry. Subsequently it is shown how this normalized coordinate space can be defined fo...

Berends, Johan H.; Veldhuis, Gerrit J.; Lambeck, Paul V.; Popma, Theo J. A.

1995-01-01

258

Measurement of the invisible W width  

International Nuclear Information System (INIS)

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)

259

Ambient dose equivalent and directional dose equivalent instruments  

International Nuclear Information System (INIS)

According to definitions of the new operational radiation quantities for environmental (area) monitoring recommended by the International Commission of Radiation Units and Measurements (ICRU) report 39, a spherical ambient dose equivalent meter and a parallel-plane directional dose equivalent meter were designed and developed. Experimental measurements for main performances and calibrations for response factors were made

260

Radiative width of the rho- meson  

International Nuclear Information System (INIS)

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 ?-?0 systems, yield a decay width for rho- ? ?-? of 67 +- 7 keV

261

A Window Width Optimized S-Transform  

Directory of Open Access Journals (Sweden)

Full Text Available Energy concentration of the S-transform in the time-frequency domain has been addressed in this paper by optimizing the width of the window function used. A new scheme is developed and referred to as a window width optimized S-transform. Two optimization schemes have been proposed, one for a constant window width, the other for time-varying window width. The former is intended for signals with constant or slowly varying frequencies, while the latter can deal with signals with fast changing frequency components. The proposed scheme has been evaluated using a set of test signals. The results have indicated that the new scheme can provide much improved energy concentration in the time-frequency domain in comparison with the standard S-transform. It is also shown using the test signals that the proposed scheme can lead to higher energy concentration in comparison with other standard linear techniques, such as short-time Fourier transform and its adaptive forms. Finally, the method has been demonstrated on engine knock signal analysis to show its effectiveness.

Jin Jiang

2008-02-01

262

Theoretical determination of etab's electromagnetic decay width  

CERN Document Server

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.

Fabiano, N

2003-01-01

263

Theoretical determination of ?b's electromagnetic decay width  

International Nuclear Information System (INIS)

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

264

Bounding the Higgs boson width through interferometry.  

Science.gov (United States)

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

Dixon, Lance J; Li, Ye

2013-09-13

265

Radiative Width of the a2 Meson  

OpenAIRE

We present data on coherent production of the pi-pi-pi+ system by 600 GeV pion beam for the C, Cu and Pb targets. The Primakoff formalism was used for extracting the radiatve width of the a2 meson. We obtain a preliminary value \\Gamma(a2->pi+gamma)=225+/-25(stat)+/-45(syst) keV.

Selex, Collaboration; Kubarovsky, V.

1999-01-01

266

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2013-03-10

267

Exotic Meson Decay Widths using Lattice QCD  

CERN Document Server

A decay width calculation for a hybrid exotic meson h, with JPC=1-+, is presented for the channel h->pi+a1. This quenched lattice QCD simulation employs Luescher's finite box method. Operators coupling to the h and pi+a1 states are used at various levels of smearing and fuzzing, and at four quark masses. Eigenvalues of the corresponding correlation matrices yield energy spectra that determine scattering phase shifts for a discrete set of relative pi+a1 momenta. Although the phase shift data is sparse, fits to a Breit-Wigner model are attempted, resulting in a decay width of about 60 MeV when averaged over two lattice sizes.

Cook, M S

2006-01-01

268

Power flux widths in the ASDEX divertor  

International Nuclear Information System (INIS)

The reciprocating Langmuir probe on ASDEX is located in the upper outer divertor and is capable of delivering a maximum of four radial profiles of plasma parameters during a discharge. The power flux profiles allow a direct evaluation of the effective power channel width which apart from offering a direct estimate of target plate power loading, it is also fundamental in understanding SOL transport processes. The evolution of power flux profiles and systematic trends of the corresponding widths for ohmically and NI heated discharges are presented for parametric scans in ne, Ip, Bt and injected neutral power. Langmuir probe data are compared and correlated with data from the Lithium beam probe which delivers density profiles in the outer midplane and the YAG Thomson scattering system which yields density and temperature near the separatrix at the lower plasma. (author) 6 refs., 4 figs

269

CMS presents new boundary of Higgs width  

CERN Multimedia

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

Katarina Anthony

2014-01-01

270

Determination of the ?(1s) leptonic width  

International Nuclear Information System (INIS)

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

271

Width of homoclinic zone for quadratic maps  

OpenAIRE

We study several families of planar quadratic diffeomorphisms near a Bogdanov-Takens bifurcation. For each family, the associate bifurcation diagram can be deduced from the interpolating flow. However, a zone of chaos confined between two lines of homoclinic bifurcation that are exponentially close to one-another is observed. The goal of this paper is to test numerically an accurate asymptotic expansion for the width of this chaotic zone for different families.

Gelfreich, Vassili; Naudot, Vincent

2008-01-01

272

Hyperfine splitting and leptonic decay width  

International Nuclear Information System (INIS)

In the mass spectroscopy of heavy quarkonia, the properties hyperfine splitting and leptonic decay width are directly related to the value of square of the modulus of the wave function at the origin. The study of these quantities can throw light on the short range part of spin spin interaction of the potential. In the present work we have used a new class of energy dependent potential to calculate the mass spectroscopy of charmonium and bottonium in the non-relativistic framework

273

QCD analysis of the tau hadronic width  

International Nuclear Information System (INIS)

The total ? hadronic width can be accurately calculated using analyticity and the operator product expansion. The theoretical analysis of this observable is updated to include all available perturbative and non-perturbative corrections. Experimental measurements of ? decay rates are used to determine with high precision the QCD running coupling constant at the scale of the ? mass. The analysis is also used to study the present discrepancy between the experimental measurements of the leptonic branching fractions of the ? and its total lifetime. (orig.)

274

Two photon width of eta_c  

CERN Document Server

We discuss the measured partial width of the pseudoscalar charmonium state, $\\eta_c$, into two photons. Predictions from potential models are examined and compared with experimental values. Including radiative corrections, it is found that present measurements are compatible both with a QCD type potential and with a static Coulomb potential, with $\\alpha_s$ evaluated at two loops. Results are also compared with those from $\\jpsi$ data through the NRQCD model.

Fabiano, N; Fabiano, Nicola; Pancheri, Giulia

2002-01-01

275

Two photon width of heavy pseudoscalar mesons  

CERN Document Server

We discuss the partial width of the pseudoscalar charmonium state eta_c and bottomonium state eta_b into two photons. Predictions from potential models are examined and compared with experimental values for the eta_c case. Through the NRQCD factorisation procedure results for eta_c are also compared with those from J/psi data, and results for eta_b to the Upsilon decay data.

Fabiano, N; Fabiano, Nicola; Pancheri, Giulia

2002-01-01

276

First Digit Distribution of Hadron Full Width  

OpenAIRE

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

Shao, Lijing; Ma, Bo-qiang

2010-01-01

277

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

International Nuclear Information System (INIS)

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)

278

Tissue Engineered Human Skin Equivalents  

Directory of Open Access Journals (Sweden)

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

Zheng Zhang

2012-01-01

279

Measurement of the total width, the electronic width, and the mass of the ?(10580) resonance  

Science.gov (United States)

We present a measurement of the parameters of the ?(10580) resonance based on a dataset collected with the BABAR detector at the SLAC PEP-II asymmetric B factory. We measure the total width ?tot=(20.7±1.6±2.5) MeV, the electronic partial width ?ee=(0.321±0.017±0.029) keV and the mass M=(10579.3±0.4±1.2) MeV/c2.

Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Gaillard, J.-M.; Hicheur, A.; Karyotakis, Y.; 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.; Leclerc, C.; Lynch, G.; Merchant, A. M.; Mir, L. M.; Oddone, P. J.; Orimoto, T. J.; Pripstein, M.; Roe, N. A.; Ronan, M. 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.; Cuhadar-Donszelmann, 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.; Mommsen, R. K.; Roethel, 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, Sh.; 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.; 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, K. R.; Schwierz, R.; Spaan, B.; Sundermann, J. E.; Bernard, D.; Bonneaud, G. R.; Brochard, F.; Grenier, P.; Schrenk, S.; Thiebaux, Ch.; 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.; Vetere, M. Lo; 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.; 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, E.; 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.; Flaecher, 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.; Staengle, H.; Willocq, S.; Cowan, R.; Sciolla, G.; Taylor, F.; Yamamoto, R. K.; Mangeol, D. J.; Patel, P. M.; Robertson, S. H.; Lazzaro, A.; Palombo, F.; Bauer, J. M.; Cremaldi, L.; 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.

2005-08-01

280

Model equivalence of PRISM programs  

OpenAIRE

The problem of deciding the probability model equivalence of two PRISM programs is addressed. In the finite case this problem can be solved (albeit slowly) using techniques from emph{algebraic statistics}, specifically the computation of elimination ideals and Gr"{o}bner bases. A very brief introduction to algebraic statistics is given. Consideration is given to cases where shortcuts to proving/disproving model equivalence are available.

Cussens, James

2008-01-01

281

Equivalence Principle and Gravitational Redshift  

CERN Document Server

We investigate leading order deviations from general relativity that violate the Einstein equivalence principle (EEP) in the gravitational standard model extension (SME). We show that redshift experiments based on matter waves and clock comparisons are equivalent to one another. Consideration of torsion balance tests, along with matter wave, microwave, optical, and M\\"ossbauer clock tests yields comprehensive limits on spin-independent EEP-violating SME terms at the $10^{-6}$ level.

Hohensee, Michael A; Peters, Achim; Mueller, Holger

2011-01-01

282

Modified model of neutron resonance widths distribution. Results of total gamma-widths approximation  

International Nuclear Information System (INIS)

Functional dependences of probability to observe given ?n0 value and algorithms for determination of the most probable magnitudes of the modified model of resonance parameter distributions were used for analysis of the experimental data on the total radiative widths of neutron resonances. As in the case of neutron widths, precise description of the ?? spectra requires a superposition of three and more probability distributions for squares of the random normally distributed values with different nonzero average and nonunit dispersion. This result confirms the preliminary conclusion obtained earlier at analysis of ?n0 that practically in all 56 tested sets of total gamma widths there are several groups noticeably differing from each other by the structure of their wave functions. In addition, it was determined that radiative widths are much more sensitive than the neutron ones to resonance wave functions structure. Analysis of early obtained neutron reduced widths distribution parameters for 157 resonance sets in the mass region of nuclei 35 ? A ? 249 was also performed. It was shown that the experimental values of widths can correspond with high probability to superposition of several expected independent distributions with their nonzero mean values and nonunit dispersion

283

Evidence for IMF Variations from the Integrated Light of SDSS Galaxies  

OpenAIRE

The H alpha equivalent width (EW) is the ratio of the H alpha flux to the continuum at 6565{\\AA}. In normal star forming galaxies the H alpha flux is dominated by reprocessed photons from stars with masses greater than 10 M_o and the 6565{\\AA} continuum is predominantly due to 0.7-3.0 M_o red giant stars. In these galaxies the H alpha EW is effectively the ratio of high mass to low mass stars and is thus sensitive to the stellar initial mass function (IMF). In Hoversten & Gl...

Hoversten, Erik A.; Glazebrook, Karl

2010-01-01

284

Artifacts for Calibration of Submicron Width Measurements  

Science.gov (United States)

Artifacts that are fabricated with the help of molecular-beam epitaxy (MBE) are undergoing development for use as dimensional calibration standards with submicron widths. Such standards are needed for calibrating instruments (principally, scanning electron microscopes and scanning probe microscopes) for measuring the widths of features in advanced integrated circuits. Dimensional calibration standards fabricated by an older process that involves lithography and etching of trenches in (110) surfaces of single-crystal silicon are generally reproducible to within dimensional tolerances of about 15 nm. It is anticipated that when the artifacts of the present type are fully developed, their critical dimensions will be reproducible to within 1 nm. These artifacts are expected to find increasing use in the semiconductor-device and integrated- circuit industries as the width tolerances on semiconductor devices shrink to a few nanometers during the next few years. Unlike in the older process, one does not rely on lithography and etching to define the critical dimensions. Instead, one relies on the inherent smoothness and flatness of MBE layers deposited under controlled conditions and defines the critical dimensions as the thicknesses of such layers. An artifact of the present type is fabricated in two stages (see figure): In the first stage, a multilayer epitaxial wafer is grown on a very flat substrate. In the second stage, the wafer is cleaved to expose the layers, then the exposed layers are differentially etched (taking advantage of large differences between the etch rates of the different epitaxial layer materials). The resulting structure includes narrow and well-defined trenches and a shelf with thicknesses determined by the thicknesses of the epitaxial layers from which they were etched. Eventually, it should be possible to add a third fabrication stage in which durable, electronically inert artifacts could be replicated in diamondlike carbon from a master made by MBE and etching as described above.

Grunthaner, Frank; Grunthaner, Paula; Bryson, Charles, III

2003-01-01

285

Correlation Widths in Quantum--Chaotic Scattering  

CERN Document Server

An important parameter to characterize the scattering matrix S for quantum-chaotic scattering is the width Gamma_{corr} of the S-matrix autocorrelation function. We show that the "Weisskopf estimate" d/(2pi) sum_c T_c (where d is the mean resonance spacing, T_c with 0 <= T_c <= 1 the "transmission coefficient" in channel c and where the sum runs over all channels) provides a very good approximation to Gamma_{corr} even when the number of channels is small. That same conclusion applies also to the cross-section correlation function.

Dietz, B; Weidenmueller, H A

2010-01-01

286

Leptonic partial widths of the excited ? states  

International Nuclear Information System (INIS)

The resonance parameters of the excited ?-family resonances, namely, the ?(4040), ?(4160), and ?(4415), were determined by fitting the R values measured by experiments. It is found that the previously reported leptonic partial widths of these states were merely one possible solution among a four-fold ambiguity. By fitting the most precise experimental data on the R values measured by the BES collaboration, this work presents all four sets of solutions. These results may affect the interpretation of the charmonium and charmonium-like states above 4 GeV/c2.

287

Leptonic partial widths of the excited ? states  

Science.gov (United States)

The resonance parameters of the excited ?-family resonances, namely, the ?(4040), ?(4160), and ?(4415), were determined by fitting the R values measured by experiments. It is found that the previously reported leptonic partial widths of these states were merely one possible solution among a four-fold ambiguity. By fitting the most precise experimental data on the R values measured by the BES collaboration, this work presents all four sets of solutions. These results may affect the interpretation of the charmonium and charmonium-like states above 4GeV/c2.

Mo, X. H.; Yuan, C. Z.; Wang, P.

2010-10-01

288

Correlation widths in quantum-chaotic scattering  

International Nuclear Information System (INIS)

An important parameter to characterize the scattering matrix S for quantum-chaotic scattering is the width ?corr of the S-matrix autocorrelation function. We show that the 'Weisskopf estimate' d/(2?)?cTc (where d is the mean resonance spacing, Tc with 0?Tc?1 the 'transmission coefficient' in channel c and where the sum runs over all channels) provides a good approximation to ?corr even when the number of channels is small. That same conclusion applies also to the cross-section correlation function.

289

Histograms, Bin Widths, and Cross Validation  

Science.gov (United States)

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

Lane, David M.

2009-03-03

290

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

CERN Document Server

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

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

2012-01-01

291

Pulse width modulation inverter with battery charger  

Science.gov (United States)

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

Slicker, James M. (Inventor)

1985-01-01

292

Translation equivalence in free groups  

CERN Document Server

Motivated by the work of Leininger on hyperbolic equivalence of homotopy classes of closed curves on surfaces, we investigate a similar phenomenon for free groups. Namely, we study the situation when two elements $g,h$ in a free group $F$ have the property that for every free isometric action of $F$ on an $\\mathbb{R}$-tree $X$ the translation lengths of $g$ and $h$ on $X$ are equal. We give a combinatorial characterization of this phenomenon, called translation equivalence, in terms of Whitehead graphs and exhibit two difference sources of it. The first source of translation equivalence comes from representation theory and the so-called $SL_2$ "trace identities". The second source comes from geometric properties of groups acting on real trees and a certain power redistribution trick. We also analyze to what extent these are applicable to the tree actions of surface groups that occur in the Thurston compactification of the Teichmuller space.

Kapovich, I; Schupp, P; Shpilrain, V; Kapovich, Ilya; Levitt, Gilbert; Schupp, Paul; Shpilrain, Vladimir

2004-01-01

293

An evaluation of equivalent models for design of rectangular microstrip antennas  

Science.gov (United States)

Simple models for rectangular microstrip antennas are described. The discontinuities in microstrip width are represented in terms of equivalent reactances and radiation conductances. The reactances were calculated by means of quasi-static methods. A number of linearly fed broadside antenna arrays, of lesser than 10 elements, were constructed, and agreement between theory and experiment is good. The influence of the equivalent inductances is small at 5 GHz.

Svedin, Jan

1987-06-01

294

REI EQUIVALENTS WITH SYNCHROPHASOR MEASUREMENTS  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents a new static network equivalencing technique that take in to consideration the influence of changes occurring in the reduced system based on voltage phasor measurements from this system. The method was developed around the REI equivalent, but in principle it can be used with any other equivalencing technique. Numerical simulations have shown that real-time measurements provided by PMUs installed on the buses of the external system can considerably improve simulation results produced by traditional REI equivalents for the operating conditions in the internal, obser ved power system.

Mihai Gavrilas

2009-11-01

295

Sievert, gray and dose equivalent.  

Science.gov (United States)

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

Pfalzner, P M

1983-12-01

296

Width distribution for random-walk interfaces  

International Nuclear Information System (INIS)

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

297

Correlation widths in quantum-chaotic scattering  

Energy Technology Data Exchange (ETDEWEB)

An important parameter to characterize the scattering matrix S for quantum-chaotic scattering is the width {Gamma}{sub corr} of the S-matrix autocorrelation function. We show that the 'Weisskopf estimate' d/(2{pi}){Sigma}{sub c}T{sub c} (where d is the mean resonance spacing, T{sub c} with 0{<=}T{sub c{<=}}1 the 'transmission coefficient' in channel c and where the sum runs over all channels) provides a good approximation to {Gamma}{sub corr} even when the number of channels is small. That same conclusion applies also to the cross-section correlation function.

Dietz, B. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany); Richter, A., E-mail: richter@ikp.tu-darmstadt.d [Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany); ECT, Villa Tambosi, I-38123 Villazzano (Trento) (Italy); Weidenmueller, H.A. [Max-Planck-Institut fuer Kernphysik, D-69029 Heidelberg (Germany)

2011-03-14

298

First Digit Distribution of Hadron Full Width  

CERN Document Server

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

Shao, Lijing; 10.1142/S0217732309031223

2010-01-01

299

First Digit Distribution of Hadron Full Width  

Science.gov (United States)

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

Shao, Lijing; Ma, Bo-Qiang

300

Direct measurement of the W boson width.  

Science.gov (United States)

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

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

2009-12-01

301

Optimal testing of equivalence hypotheses  

CERN Document Server

In this paper we consider the construction of optimal tests of equivalence hypotheses. Specifically, assume X_1,..., X_n are i.i.d. with distribution P_{\\theta}, with \\theta \\in R^k. Let g(\\theta) be some real-valued parameter of interest. The null hypothesis asserts g(\\theta)\

Romano, J P

2005-01-01

302

Equivalences to the triangulation conjecture  

OpenAIRE

We utilize the obstruction theory of Galewski-Matumoto-Stern to derive equivalent formulations of the Triangulation Conjecture. For example, every closed topological manifold M^n with n > 4 can be simplicially triangulated if and only if the two distinct combinatorial triangulations of RP^5 are simplicially concordant.

Randall, Duane

2002-01-01

303

Quantum Equivalent Magnetic Fields that Are Not Classically Equivalent  

CERN Document Server

We construct pairs of compact K\\"ahler-Einstein manifolds $(M_i,g_i,\\omega_i)$ ($i=1,2)$ of complex dimension $n$ with the following properties: The canonical line bundle $L_i=\\bigwedge^n T^*M_i$ has Chern class $[\\omega_i/2\\pi]$, and for each integer $k$ the tensor powers $L_1^{\\otimes k}$ and $L_2^{\\otimes k}$ are isospectral for the bundle Laplacian associated with the canonical connection, while $M_1$ and $M_2$ -- and hence $T^*M_1$ and $T^*M_2$ -- are not homeomorphic. In the context of geometric quantization, we interpret these examples as magnetic fields which are quantum equivalent but not classically equivalent. Moreover, we construct many examples of line bundles $L$, pairs of potentials $Q_1$, $Q_2$ on the base manifold, and pairs of connections $\

Gordon, Carolyn; Schueth, Dorothee; Webb, David

2010-01-01

304

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

Science.gov (United States)

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

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

2014-12-01

305

The attenuation of the neutron dose equivalent in a labyrinth through an accelerator shield  

International Nuclear Information System (INIS)

The attenuation of neutron dose equivalent in concrete labyrinths with rectangular bends was studied by means of neutron sources and rem counters. The number of bends, the length of each section, and the width of the labyrinth could be varied. The results of these measurements were compared with the dose equivalent attenuation found in a labyrinth at the DESY 7-GeV electron synchrotron, with published data from a proton accelerator and from a nuclear reactor. An empirical formula describing the neutron dose equivalent is presented. (author)

306

Scaling of the Divertor Heat Flux Width in the DIII-D Tokamak; Scaling of the Divertor Heat Flux Width in the DIII-D Tokamak  

International Nuclear Information System (INIS)

Full text: DIII-D measurements indicate a systematic narrowing of the divertor heat flux width ?q with plasma current in H-mode plasmas and significantly weaker dependence on other parameters. Comparisons of ?q with upstream SOL profiles indicate a similar variation, consistent with expectations from flux-limited transport. The inverse dependence of ?q on plasma current suggests that physics solutions for heat flux control may be more essential in next step devices to reduce the local heat flux below the maximum steady-state heat load sustainable by material surfaces of ? 10 MW/m2. We find that the heat flux profile is well fit by a two-parameter function with one parameter (?pvt) characterizing the profile in the private flux region and the second (?sol) characterizing the SOL. The heat flux integral width (integral of the profile divided by its peak value) of this function is a weighted linear sum of these two parameters. The integral width scales inversely with Ip, and has weaker dependencies on other parameters. However, ?sol is found to have a much simpler scaling, depending only on Ip (or equivalently, the poloidal magnetic field Bp). Measurements of upstream ne and Te profiles with an upgraded Thomson scattering diagnostic has made it possible to test parallel and radial transport models. The SOL profiles exhibit a narrowinhe SOL profiles exhibit a narrowing ne with increasing Ip consistent with the measured divertor heat flux and a flux-limited parallel transport model. The strong dependence of ?q on Bp suggests two possible physics mechanisms setting the heat flux width. A semi-empirical model based on ion orbit drifts is consistent with the measured heat flux width and the dependence of the SOL ne profile. A critical pressure gradient model was also tested finding the SOL pressure profile width scaling consistently with a calculation of the ideal ballooning stability limit. A density scan from a low density attached state to a high density detached divertor state revealed SOL profile scale lengths related to the heat flux width for attached conditions. This suggests that the upstream profiles can be used to make inferences about radial transport under detached conditions where the divertor heat flux profile no longer represents the upstream SOL transport. (author)

307

Formulae for partial widths derived from the Lindblad equation  

CERN Document Server

A method for calculating partial widths of auto-ionizing states is proposed. It combines either a complex absorbing potential or exterior complex scaling with the Lindblad equation. The corresponding classical rate equations are reproduced, and the trace conservation inherent in the Lindblad equation ensures that the partial widths sums up to the total width of the initial auto-ionizing state.

Selstø, Sølve

2012-01-01

308

Measurement of radiative widths at COMPASS  

Energy Technology Data Exchange (ETDEWEB)

COMPASS is a multi-purpose fixed-target experiment at CERN SPS, that investigates the structure and spectroscopy of hadrons. Dissociation of pions on nuclear or hydrogen targets provides clean access to the light meson spectrum. During a short run with ?{sup -} beam on lead in the year 2004, about 4 million exclusive ?{sup -}?{sup -}?{sup +} events have been collected. For the 3 million events with low momentum transfer t' < 0.01 GeV{sup 2}/c{sup 2}, coherent scattering off the nucleus as a whole can be assumed, with contributions from Reggeon (Pomeron) and quasi-real photon exchange. For the lowest t' < 0.001 GeV{sup 2}/c{sup 2}, the electromagnetic interaction part becomes apparent. The partial-wave analysis of these data leads to the observation of resonances as the a{sub 2}(1320) dominantly produced by quasi-real photon exchange. The extraction of their radiative widths is presented.

Grabmueller, Stefanie [Technische Universitaet Muenchen, Physik-Department E18, 85748 Garching (Germany)

2013-07-01

309

A rapidly fabricated dermal equivalent  

OpenAIRE

Cell encapsulation in collagen hydrogels affords the ability to rapidly create living yet mechanically weak tissue equivalents. A previously developed compression technique that removes the interstitial fluid from these hydrogels allows for a rapid improvement of the mechanical strength with adequate cell survival. However, although the UTS of the resulting compressed collagen-rich tissue sheets approach those found in vivo, the break strength, due to the small size of these sh...

Ananta, M.

2011-01-01

310

On computing minimal equivalent subformulas  

OpenAIRE

A propositional formula in Conjunctive Normal Form (CNF) may contain redundant clauses | clauses whose removal from the for- mula does not a ect the set of its models. Identi cation of redundant clauses is important because redundancy often leads to unnecessary com- putation, wasted storage, and may obscure the structure of the problem. A formula obtained by the removal of all redundant clauses from a given CNF formula F is called a Minimal Equivalent Subformula (MES) of F. ...

Belov, Anton; Janota, Mikolas; Lynce, Ine?s; Marques-silva, Joao

2012-01-01

311

Blast Wave Characteristics and Equivalency  

OpenAIRE

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 ...

Sochet, Isabelle; Schneider, Helmut

2010-01-01

312

Narrow-width mechanism of a=5 ?-state  

International Nuclear Information System (INIS)

Narrow-width mechanism of ?5H is discussed by calculating conversion widths to all its possible decay channels. Since the conversion processes have small reaction Q values, the three- and four- body decays are strongly suppressed owing to small phase volumes available. Decay widths to the two-body channels are significantly reduced by the distortion of emitted-particle waves. This mechanism brings about a narrow width of ?5H. The total width is estimated to be 0.87 MeV, in which the largest contribution comes from the decay into the ?4H*+? channel. (author)

313

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

Science.gov (United States)

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 potentials strongly suggests that supernova-driven winds must be of critical importance in the subsequent evolution of these systems.

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

314

Equivalence in Bilingual Lexicography: Criticism and Suggestions*  

OpenAIRE

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 metalexicogra...

Herbert Ernst Wiegand

2011-01-01

315

Pulse widths effects on scintillator saturation  

International Nuclear Information System (INIS)

A test was performed over an extensive range of irrradiance (approximately five orders of magnitude) to see to what extent organic scintillators responded linearly with x-ray input. At the highest levels of irradiance achievable with the experimental configuration, but only for pulses in the region of 4.0 ns or wider, a degree of nonlinear response was observed for some of the scintillators. The data suggest that at levels below 1 mJ/cm2-ns it is safe to asume that for pulses 6.5 ns and shorter there is no significant level of nonlinearity to x rays with spectrum. For the cases of undoped NE111 and NE111 doped with 10 percent benzophenone, experimental conditions were such that it was possible to accumulate data significantly above the 1 mJ/cm2-ns level of irradiance. It is with these cases that a nonlinear response was observed. It is assumed that the same nonlinearity would have also been noticed had experimental conditions been such that equivalent levels of irradiance could have been achieved at the time the other samples were studied

316

GAP WIDTH STUDY IN LASER BUTT-WELDING  

DEFF Research Database (Denmark)

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.

Gong, Hui; Olsen, Flemming Ove

1999-01-01

317

?onsolidation and creepof subfoundations having finite widths ???????????? ? ?????????? ????????? ??????????? ???????? ??????  

Directory of Open Access Journals (Sweden)

Full Text Available The authors formulate and solve the problem of consolidation and creep of saturated clay subfoundations exposed to localized loads (the two-dimensional problem formulation. The findings have proven that, if the two-dimensional problem is considered, any excessive pore pressure is concentrated immediately under the area exposed to the localized loading, and it penetrates into the depth equal to 1/2 of the strength of the compressed width. Subfoundation subsidence is caused by both shear and 3D deformations of soil. Besides, the ratio of shear-to-3D deformations reaches 10. Therefore, the authors propose to represent the subfoundation subsidence as the sum of shear and 3D deformations.The differential equation of the filter consolidation, if considered as the 2D problem, is solved using the Mathcad software. The software is used to analyze the isolines of excessive pore pressure at any moment following the loading application. New depen- dence representing the ratio of the changing area of the diagram of the average effective tension to the area of the diagram of the average tension in the stabilized condition is proposed by the authors.In the final section of the article, the authors solve the problem of prognostication of the subsidence pattern for the water saturated subfoundation with account for the shear creep of the soil skeleton. The authors employ the visco-elastic Bingham model characterized by time-dependent viscosity ratios. The authors have proven that in this case the subsidence following the shear load will develop as of the moment of application of the external load pro rata the logarithm of time irrespectively of the process of filtration consolidation.????????? ?????????? ? ??????? ????? ???????????? ? ?????????? ?????????????? ????????? ?? ????????? ??????? ??? ???????????? ??????? ???????? (??????? ??????. ????????, ??? ? ???????? ??????? ?????? ?????????? ??????? ???????? ? ????????? ?????? ?????????? ???????????? ??????????????? ??? ??????? ????????? ?? ??????? 1/2 ?? ???????? ????????? ????? ? ????? ????????? ???? ?? ??????? ? ??? ?????? ????????? ??????????? ??? ??????????, ??? ? ????????? ???????????? ??????. ????? ????, ??????????? ????????? ? ???????? ?????? ????????? 10. ??????? ?????????? ?????? ????????? ?????????? ? ???? ????? ?? ???????? ? ????????? ?????????? ? ???????????.??? ??????? ????????????????? ????????? ?????????????? ???????????? ? ???????? ?????????? ?????? ???????????? ??????????? ???????? Mathcad. ??? ????????? ??????????? ??????? ?? ??????????? ???????? ??????????? ???????? ???????? ??? ?????? ??????? ??????? ?? ?????? ?????????? ????????. ??? ??????????? ??????? ???????????? ?????? ?????????? ????? ??????????? ? ???? ????????? ???????????? ??????? ????? ???????? ???????????? ?????????? ? ??????? ????? ???????? ?????????? ? ????????????????? ?????????.? ?????????????? ??????? ?????? ????????? ??????? ?????? ?? ??????????????? ?????? ??????????????? ????????? ? ?????? ?????????

Ter-Martirosyan Zaven Grigor’evich

2013-04-01

318

Nanosecond pulse width dependence of nonphotochemical laser-induced nucleation of potassium chloride  

Science.gov (United States)

The effect of laser pulse width on the efficiency of nonphotochemical laser-induced nucleation (NPLIN) of supersaturated aqueous solutions of KCl has been studied. At equivalent peak-power densities it was observed that the same fractions of samples were nucleated for both short (6 ns) and long (200 ns) near-infrared laser pulses. The results show that the efficiency depends on the peak-power density and not on the duration, or total energy, of the laser pulses. It is concluded that the mechanism is unlikely to be based solely on diffusion of solute to a sub-critical cluster.

Ward, Martin R.; Ballingall, Iain; Costen, Matthew L.; McKendrick, Kenneth G.; Alexander, Andrew J.

2009-10-01

319

EVIDENCE FOR A CORRELATION BETWEEN THE Si II ?4000 WIDTH AND TYPE Ia SUPERNOVA COLOR  

International Nuclear Information System (INIS)

We study the pseudo-equivalent width of the Si II ?4000 feature of Type Ia supernovae (SNe Ia) in the redshift range 0.0024 ? z ? 0.634. We find that this spectral indicator correlates with the light curve color excess (SALT2c) as well as previously defined spectroscopic subclasses (Branch types) and the evolution of the Si II ?6150 velocity, i.e., the so-called velocity gradient. Based on our study of 55 objects from different surveys, we find indications that the Si II ?4000 spectral indicator could provide important information to improve cosmological distance measurements with SNe Ia.

320

Conformal dynamical equivalence and applications  

Energy Technology Data Exchange (ETDEWEB)

The 'Conformal Dynamical Equivalence' (CDE) approach is briefly reviewed, and some of its applications, at various astrophysical levels (Sun, Solar System, Stars, Galaxies, Clusters of Galaxies, Universe as a whole), are presented. According to the CDE approach, in both the Newtonian and general-relativistic theories of gravity, the isentropic hydrodynamic flows in the interior of a bounded gravitating perfect-fluid source are dynamically equivalent to geodesic motions in a virtual, fully defined fluid source. Equivalently, the equations of hydrodynamic motion in the former source are functionally similar to those of the geodesic motions in the latter, physically, fully defined source. The CDE approach is followed for the dynamical description of the motions in the fluid source. After an observational introduction, taking into account all the internal physical characteristics of the corresponding perfect-fluid source, and based on the property of the isentropic hydrodynamic flows (quite reasonable for an isolated physical system), we examine a number of issues, namely, (i) the classical Newtonian explanation of the celebrated Pioneer-Anomaly effect in the Solar System, (ii) the possibility of both the attractive gravity and the repulsive gravity in a non-quantum Newtonian framework, (iii) the evaluation of the masses - theoretical, dynamical, and missing - and of the linear dimensions of non-magnetized and magnetized large-scale cosmological structures, (iv) the explanation of the flat-rotation curves of disc galaxies, (v) possible formation mechanisms of winds and jets, and (vi) a brief presentation of a conventional approach - toy model to the dynamics of the Universe, characterized by the dominant collisional dark matter (with its subdominant luminous baryonic 'contamination'), correctly interpreting the cosmological observational data without the need of the notions dark energy, cosmological constant, and universal accelerating expansion.

Spyrou, N K, E-mail: spyrou@astro.auth.gr [Astronomy Department, Aristoteleion University of Thessaloniki, 541.24 Thessaloniki, Macedonia, Hellas (Greece)

2011-02-01

321

Conformal dynamical equivalence and applications  

Science.gov (United States)

The "Conformal Dynamical Equivalence" (CDE) approach is briefly reviewed, and some of its applications, at various astrophysical levels (Sun, Solar System, Stars, Galaxies, Clusters of Galaxies, Universe as a whole), are presented. According to the CDE approach, in both the Newtonian and general-relativistic theories of gravity, the isentropic hydrodynamic flows in the interior of a bounded gravitating perfect-fluid source are dynamically equivalent to geodesic motions in a virtual, fully defined fluid source. Equivalently, the equations of hydrodynamic motion in the former source are functionally similar to those of the geodesic motions in the latter, physically, fully defined source. The CDE approach is followed for the dynamical description of the motions in the fluid source. After an observational introduction, taking into account all the internal physical characteristics of the corresponding perfect-fluid source, and based on the property of the isentropic hydrodynamic flows (quite reasonable for an isolated physical system), we examine a number of issues, namely, (i) the classical Newtonian explanation of the celebrated Pioneer-Anomaly effect in the Solar System, (ii) the possibility of both the attractive gravity and the repulsive gravity in a non-quantum Newtonian framework, (iii) the evaluation of the masses - theoretical, dynamical, and missing - and of the linear dimensions of non-magnetized and magnetized large-scale cosmological structures, (iv) the explanation of the flat-rotation curves of disc galaxies, (v) possible formation mechanisms of winds and jets, and (vi) a brief presentation of a conventional approach - toy model to the dynamics of the Universe, characterized by the dominant collisional dark matter (with its subdominant luminous baryonic "contamination"), correctly interpreting the cosmological observational data without the need of the notions dark energy, cosmological constant, and universal accelerating expansion.

Spyrou, N. K.

2011-02-01

322

Calculation methods for determining dose equivalent  

International Nuclear Information System (INIS)

A series of calculations of neutron fluence as a function of energy in an anthropomorphic phantom was performed to develop a system for determining effective dose equivalent for external radiation sources. Critical organ dose equivalents are calculated and effective dose equivalents are determined using ICRP-26 [1] methods. Quality factors based on both present definitions and ICRP-40 definitions are used in the analysis. The results of these calculations are presented and discussed. The effective dose equivalent determined using ICRP-26 methods is significantly smaller than the dose equivalent determined by traditional methods. No existing personnel dosimeter or health physics instrument can determine effective dose equivalent. At the present time, the conversion of dosimeter response to dose equivalent is based on calculations for maximal or ''cap'' values using homogeneous spherical or cylindrical phantoms. The evaluated dose equivalent is, therefore, a poor approximation of the effective dose equivalent as defined by ICRP Publication 26. 3 refs., 2 figs., 1 tab

323

Equivalence Principle in Chameleon Models  

CERN Document Server

Most theories that predict time and/or space variation of fundamental constants also predict violations of the Weak Equivalence Principle (WEP). Khoury and Weltmann proposed the chameleon model in 2004 and claimed that this model avoids experimental bounds on WEP. We present a contrasting view based on an approximate calculation of the two body problem for the chameleon field and show that the force depends on the test body composition. Furthermore, we compare the prediction of the force on a test body with E\\"otv\\"os type experiments and find that the chameleon field effect cannot account for current bounds.

Kraiselburd, Lucila; Salgado, Marcelo; Sudarsky, Daniel

2013-01-01

324

Equivalence principle in Chameleon models .  

Science.gov (United States)

Most theories that predict time and/or space variation of fundamental constants also predict violations of the Weak Equivalence Principle (WEP). Khoury and Weltmann proposed the chameleon model in 2004 and claimed that this model avoids experimental bounds on WEP. We present a contrasting view based on an approximate calculation of the two body problem for the chameleon field and show that the force depends on the test body composition. Furthermore, we compare the prediction of the force on a test body with Eötvös type experiments and find that the chameleon field effect cannot account for current bounds.

Kraiselburd, L.; Landau, S.; Salgado, M.; Sudarsky, D.

325

Therapeutic equivalents in clinical practice.  

Science.gov (United States)

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

Benson, M D

2001-01-01

326

Light WIMPs And Equivalent Neutrinos  

CERN Document Server

Very light WIMPs (chi), thermal relics that annihilate late in the early Universe, change the energy and entropy densities at BBN and at recombination. BBN, in combination with the CMB, can remove some of the degeneracies among light WIMPs and equivalent neutrinos, constraining the existence and properties of each. Depending on the nature of the light WIMP (Majorana or Dirac fermion, real or complex scalar) the joint BBN + CMB analyses set lower bounds to m_chi in the range 0.5 - 5 MeV (m_chi/m_e > 1 - 10), and they identify best fit values for m_chi in the range 5 - 10 MeV. The joint BBN + CMB analysis finds a best fit value for the number of equivalent neutrinos, Delta N_nu ~ 0.65, nearly independent of the nature of the WIMP. In the absence of a light WIMP (m_chi > 20 MeV), N_eff = 3.05(1 + Delta N_nu /3). In this case, there is excellent agreement between BBN and the CMB, but the joint fit reveals Delta N_nu = 0.40+-0.17, disfavoring standard big bang nucleosynthesis (SBBN) (Delta N_nu = 0) at ~ 2.4 sigma...

Steigman, Gary

2014-01-01

327

Ronchi test with equivalent wavelength  

Science.gov (United States)

The Ronchi test has been consolidated as one of the most successful and powerful techniques applied to determine the quality of optical surfaces.5 In recent years, the development and availability of LCD's (Liquid Crystal Displays) have allowed the incorporation of LCD's instead of the traditional static ruling. The easy change of the characteristics of the fringes in the ruling, such as frequency, position, and geometrical form, transformed this technique into a dynamic test.1, 8 Its physical interpretation fully connected with a lateral sheared interferometer 5, 6 and some concepts and results associated with the interferometric concept of equivalent wavelenght have been applied in this proposal for the evaluation of optical surfaces. The procedure described here to evaluate an optical surface uses the Ronchi test with the equivalent wavelenght.6, 10 This is achieved by registering and computing Ronchigrams obtained by employing, separately, two distinct wavelengths. For a particular mirror, some results are shown in order to demonstrate the enhancement of the test with this proposal.

García-A., Anmi; Granados-A., Fermín Solomon; Cornejo-R., Alejandro

2010-02-01

328

Level widths in 9He and 10He  

International Nuclear Information System (INIS)

The lowest observed resonance in each of 9He and 10He is narrow, with widths 0.10±0.06 MeV and 0.3±0.2 MeV, respectively. For 9He, the calculated width is an order of magnitude larger. For 10He, the calculated width is appreciably larger if the observed resonance is the ground state, but consistency seems possible if it is an excited state with the ground state unobserved

329

Crack Width Analysis of Steel Fiber Reinforced Concrete Elements  

OpenAIRE

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 Lith...

Darius Ulbinas; Gintaris Kaklauskas

2011-01-01

330

An investigation of bridge width measurement and processing capabilities (1985)  

Energy Technology Data Exchange (ETDEWEB)

An investigation of Mound`s ability to measure and process bridges was conducted in 1985. Prior to improvements in the measuring system and technique, bridge width was found to have a sigma of 0.00019 in. After improvements were made, a sigma of 0.000047 was realized. Bridge length was found to be more erratic than width, although most of the inaccuracy was caused by measurement uncertainty. Length and width were found to have little or no correlation.

Armstrong, K.P. [comp.

1989-05-15

331

The significance of biometric parameters in determining anterior teeth width  

Directory of Open Access Journals (Sweden)

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.

Strajni? Ljiljana

2013-01-01

332

On absolute values of ?-widths for heavy spherical nuclei  

International Nuclear Information System (INIS)

On the basis of the ordinary ?-particle Saxon-Woods shell-model formfactors with configuration mixing the absolute values of ?-widths are calculated for heavy spherical nuclei. The importance of the pairing and superfluid correlations is demonstrated for all favourable and semi-favourable ?-transitions, including the same ?-transitions in Po210, Po211, Bi211 and Po212. The calculate ?-widths are close to the corresponding experimental ?-widths. (orig.)

333

Beam width of highly-focused radially-polarized fields  

OpenAIRE

On the basis of a formal analogy with the irradiance moments, analytical definitions are proposed for the width of both the transverse and the longitudinal component of rotationally-symmetric radially-polarized fields at the focal plane of a high-focusing optical system. The beam width of the whole field is also introduced. The transverse beam size is thus associated with the overall spatial structure of the field. The beam-width definitions are applied to an illustrative example, which enabl...

Marti?nez Herrero, R.; Meji?as, P. M.; Manjavacas, Alejandro

2010-01-01

334

Research on Fairway Width Design in Curved Bridge Waters Channel  

OpenAIRE

Bridge construction can promote economic development but if the bridge layout is unreasonable, it would hinder ship’s safety navigation in the bridge area. There is little reference for fairway width design about curved bridge channel in ??inland river navigation standards?? of China. In this study, a fairway width design method in curved bridge channel was put forward by taking into account the scope of turbulent scope of pier, ship’s track width, drifting distance due to wind, d...

Chi Hong-Fu; Wang Yuan-Jiao

2013-01-01

335

Biologic width and its importance in periodontal and restorative dentistry  

OpenAIRE

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...

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

2012-01-01

336

From body burden to effective dose equivalent  

International Nuclear Information System (INIS)

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

337

Congruences of strongly Morita equivalent posemigroups  

Directory of Open Access Journals (Sweden)

Full Text Available We prove that congruence lattices of strongly Morita equivalent posemigroupswith common joint weak local units are isomorphic. Moreover, the quotientposemigroups by the congruences that correspond to each other under this isomorphism are also strongly Morita equivalent.

T. Tärgla

2012-09-01

338

33 CFR 155.120 - Equivalents.  

Science.gov (United States)

...2010-07-01 2010-07-01 false Equivalents. 155.120 Section 155.120 Navigation and Navigable Waters COAST GUARD...POLLUTION PREVENTION REGULATIONS FOR VESSELS General § 155.120 Equivalents. (a) For ships...

2010-07-01

339

Factors determining spectral width of HF echoes from high latitudes  

OpenAIRE

Spectral width is one of the standard data types produced by the Super Dual Auroral Radar Network (SuperDARN). A pronounced latitudinal gradient in spectral width has been reported in the literature and is used as an empirical proxy for the ionospheric footprint of the open-closed field-line boundary. In this work we investigated the daytime radar echo properties near the spectral width boundary using a multi-frequency sounding regime. We have found that the relatively large spectral width va...

Ponomarenko, P. V.; Waters, C. L.; Menk, F. W.

2007-01-01

340

Beyond Language Equivalence on Visibly Pushdown Automata  

OpenAIRE

We study (bi)simulation-like preorder/equivalence checking on the class of visibly pushdown automata and its natural subclasses visibly BPA (Basic Process Algebra) and visibly one-counter automata. We describe generic methods for proving complexity upper and lower bounds for a number of studied preorders and equivalences like simulation, completed simulation, ready simulation, 2-nested simulation preorders/equivalences and bisimulation equivalence. Our main results are that ...

Srba, Jir?i?

2009-01-01

341

Topological equivalences for differential graded algebras  

CERN Document Server

We investigate the relationship between differential graded algebras (dgas) and topological ring spectra. Every dga C gives rise to an Eilenberg-Mac Lane ring spectrum denoted HC. If HC and HD are weakly equivalent, then we say C and D are topologically equivalent. Quasi-isomorphic dgas are topologically equivalent, but we produce explicit counter-examples of the converse. We also develop an associated notion of topological Morita equivalence using a homotopical version of tilting.

Dugger, D; Dugger, Daniel; Shipley, Brooke

2006-01-01

342

Auto-equivalences of stable module categories  

OpenAIRE

We construct nontrivial auto-equivalences of stable module categories for elementary, local symmetric algebras over a field k. These auto-equivalences are modeled after the spherical twists of Seidel and Thomas and the $\\mathbb{P}^n$-twists of Huybrechts and Thomas, which yield auto-equivalences of the derived category of coherent sheaves on a variety. For group algebras of p-groups in characteristic p we recover many of the auto-equivalences corresponding to endo-trivial mo...

Dugas, Alex

2014-01-01

343

Discovering Classes of Strongly Equivalent Logic Programs  

OpenAIRE

In this paper we apply computer-aided theorem discovery technique to discover theorems about strongly equivalent logic programs under the answer set semantics. Our discovered theorems capture new classes of strongly equivalent logic programs that can lead to new program simplification rules that preserve strong equivalence. Specifically, with the help of computers, we discovered exact conditions that capture the strong equivalence between a rule and the empty set, between tw...

Chen, Y.; Lin, F.

2011-01-01

344

Images Identification Based on Equivalence Classes  

OpenAIRE

The image identification problem consists in identifying all the equivalent forms of a given reference image. An image is equivalent to the reference image, if the former results from the application of an image operator (or a composition of image operators) to the latter. Depending on the application, different sets of image operators are considered. The equivalence quantification is done in three levels. In the first level, we construct the set of equivalent images which is composed of the ...

Maret, Y.; Garcia Molina, G.; Ebrahimi, T.

2005-01-01

345

Tissue equivalence in neutron dosimetry  

International Nuclear Information System (INIS)

A brief review is presented of the essential features of neutron tissue equivalence for radiotherapy and gives the results of a computation of relative absorbed dose for 14 MeV neutrons, using various tissue models. It is concluded that for the Bragg-Gray equation for ionometric dosimetry it is not sufficient to define the value of W to high accuracy and that it is essential that, for dosimetric measurements to be applicable to real body tissue to an accuracy of better than several per cent, a correction to the total absorbed dose must be made according to the test and tissue atomic composition, although variations in patient anatomy and other radiotherapy parameters will often limit the benefits of such detailed dosimetry. (U.K.)

346

Equivalent velocity spectroscopy for development of femtosecond pulse radiolysis system  

International Nuclear Information System (INIS)

For studies of electron beam induced ultra-fast reaction process, femtosecond (fs) pulse radiolysis is under construction. To realize fs time resolution, fs electron and analyzing light pulses and their jitter compensation system are needed. About a 100fs electron pulse was generated by a photocathode RF gun LINAC and a magnetic pulse compressor. Synchronized Ti: Sapphire laser have a pulse width about 160fs. And, it is significant to avoid degradation of time resolution caused by velocity difference between electron and analyzing light in a sample. In the 'Equivalent velocity spectroscopy' method, incident analyzing light is slant toward electron beam with an angle associated with refractive index of sample. Then, to overlap light wave front and electron pulse shape, electron pulse shape is slanted toward the direction of travel. As a result of the equivalent velocity spectroscopy for hydrated electrons, using slanted electron pulse shape, optical absorption rise time was about 1.4ps faster than normal electron pulse shape. Thus, the 'Equivalent velocity spectroscopy' is effective for femtosecond pulse radiolysis. (author)

347

Note on equivalent states of particles  

International Nuclear Information System (INIS)

Two states are defined as equivalent if they have the same total energy and set of quantum numbers, but have different number of particles. The binding energy of a two-particle system can be due to the time-average mass defect of its equivalent states. The normalization of the wave function relates some coefficients and limits the contribution of each equivalent state

348

Equivalence in Bilingual Lexicography: Criticism and Suggestions*  

Directory of Open Access Journals (Sweden)

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, SYNTAGMENÄQUIVALENZ,NULLÄQUIVALENZ, KORRESPONDENZ

Herbert Ernst Wiegand

2011-10-01

349

The Local Lyman-$\\alpha$ Forest; 1, Distribution of HI Absorbers, Doppler Widths, and Baryon Content  

CERN Document Server

In Paper I of this series (astro-ph/9911117) we described observations of 15 extragalactic targets taken with the Hubble Space Telescope GHRS/G160M grating for studies of the low-z Lya forest. We reported the detection of 110 Lya absorbers at significance level >3 sigma in the redshift range z=0.002-0.069, over a total pathlength of 116,000 km/s. In this second paper, we evaluate the physical properties of these Lya absorbers and compare them to their high-z counterparts. The distribution of Doppler parameters is similar to that at high redshift, with mean b = 35.0 +- 16.6 km/s. The true Doppler parameter may be somewhat lower, owing to component blends and non-thermal velocities. The distribution of equivalent widths exhibits a significant break at W~133mA, with an increasing number of weak absorbers (10mA-100mA). Adopting a curve of growth with b = 25 +- 5km/s and applying a sensitivity correction as a function of equivalent width and wavelength, we derive the distribution in column density, Nh^{-1.80+-0.05...

Penton, S V; Stocke, J T; Penton, Steven V.; Stocke, John T.

1999-01-01

350

Characterization and modeling of a piezoelectric micromachined ultrasonic transducer with a very large length/width aspect ratio  

International Nuclear Information System (INIS)

The objective of the current study was to characterize and model the performance of piezoelectric micromachined ultrasonic transducers (pMUTs) with large length/width aspect ratios. Single-element pMUTs with 20 different dimensions corresponding to aspect ratios ranging from 5:1 to 23:1 were designed. Multiple samples were fabricated for each design so that statistically meaningful data could be obtained. The pMUTs were characterized by the impedance measurement combined with an equivalent circuit analysis. A one-dimensional composite beam model was also used to correlate the equivalent circuit components with the structural parameters, and gain insight into the performance characteristics of pMUTs. The resonant frequencies were observed to decrease with the width of the membrane, but have no appreciable length dependence. With the correction of parasitic capacitance, the effective coupling coefficients were observed to increase with the width up to around 150 µm and then decrease. However, they did not show clear and consistent length dependence. The variation of the coupling coefficient as a function of width of the membrane was shown to be mainly due to the relative ratios between the electrode and membrane widths rather than membrane width itself. Although the model presented in this study was a simple one-dimensional electro-mechanical model, it did seem to offer both good qualitative and quantitative insights into the performance of pMUTs and provide a convenierformance of pMUTs and provide a convenient tool for designing thin membrane transducers with a large aspect ratio. The model can also take into consideration the residual stress effect and offer an even more realistic prediction

351

Radiative width of the A2(1310)  

International Nuclear Information System (INIS)

Using the Primakoff formalism, we have extracted the radiative decay width of the A2+(1310) produced in coherent interactions of 200 GeV/c ?+ mesons in nuclear targets. The width obtained is 295 +- 60 keV, a value consistent with quark-model predictions. (orig.)

352

Spreading width of nuclear excitations at finite temperature  

International Nuclear Information System (INIS)

In this paper the damping of single-particle states and giant vibrations in heavy nuclei are calculated as a function of the nuclear excitation energy. The single-particle width increases almost linearly with temperature. The width of giant vibrations remains essentially constant in the interval O?T?3 MeV

353

Convex Bodies of Constant Width and Constant Brightness  

OpenAIRE

In 1926 S. Nakajima (= A. Matsumura) showed that any convex body in $\\R^3$ with constant width, constant brightness, and boundary of class $C^2$ is a ball. We show that the regularity assumption on the boundary is unnecessary, so that balls are the only convex bodies of constant width and brightness.

Howard, Ralph

2003-01-01

354

An H-alpha survey aiming at the detection of extraplanar diffuse ionized gas in halos of edge-on spiral galaxies. I. How common are gaseous halos among non-starburst galaxies?  

CERN Document Server

In a series of two papers we present results of a new H-alpha imaging survey, aiming at the detection of extraplanar diffuse ionized gas in halos of late-type spiral galaxies. We have investigated a sample of 74 nearby edge-on spirals, covering the northern and southern hemisphere. In 30 galaxies we detected extraplanar diffuse emission at mean distances of |z|~1-2 kpc. Individual filaments can be traced out to |z|<= 6 kpc in a few cases. We find a good correlation between the FIR flux ratio (S_60/S_100) and the SFR per unit area (L_FIR/D^2_25), based on the detections/non-detections. This is actually valid for starburst, normal and for quiescent galaxies. A minimal SFR per unit area for the lowest S_60/S_100 values, at which extended emission has been detected, was derived, which amounts to (dE/dt)_A25^thres = (3.2+-0.5)x10E+40 erg/s/kpc^2. There are galaxies where extraplanar emission was detected at smaller values of L_FIR/D^2_25, however, only in combination with a significantly enhanced dust temperatu...

Rossa, J; Rossa, Joern; Dettmar, Ralf-Juergen

2003-01-01

355

Video digitizer (real time-frame grabber) with region of interest suitable for quantitative data analysis used on the infrared and H alpha cameras installed on the DIII-D experiment  

International Nuclear Information System (INIS)

This paper describes a CAMAC based video digitizer with region of interest (ROI) capability that was designed for use with the infrared and H alpha cameras installed by Lawrence Livermore Laboratory on the DIII-D experiment at G.A. Technologies in San Diego, California. The video digitizer uses a custom built CAMAC video synchronizer module to clock data into a CAMAC transient recorder on a line-by-line basis starting at the beginning of a field. The number of fields that are recorded is limited only by the available transient recorder memory. In order to conserve memory, the CAMAC video synchronizer module provides for the alternative selection of a specific region of interest in each successive field to be recorded. Memory conservation can be optimized by specifying lines in the field, start time, stop time, and the number of data samples per line. This video frame grabber has proved versatile for capturing video in such diverse applications as recording video fields from a video tape recorder played in slow motion or recording video fields in real time during a DIII-D shot. In other cases, one or more lines of video are recorded per frame to give a cross sectional slice of the plasma. Since all the data in the digitizer memory is synchronized to video fields and lines, the data can be read directly into the control computer in the proper matrix format to facilitate rapid processing, display, and permanent storage

356

A large, multi-epoch H{\\alpha} survey at z=2.23, 1.47, 0.84 & 0.40: the 11 Gyr evolution of star-forming galaxies from HiZELS  

CERN Document Server

This paper presents new deep and wide narrow-band surveys undertaken with UKIRT, Subaru and the VLT; a unique combined effort to select large, robust samples of H-alpha (Ha) emitters at z=0.40, 0.84, 1.47 and 2.23 (corresponding to look-back times of 4.2, 7.0, 9.2 and 10.6 Gyrs) in a uniform manner over ~2 deg^2 in the COSMOS and UDS fields. The deep multi-epoch Ha surveys reach ~3M_sun/yr out to z=2.2 for the first time, while the wide area and the coverage over two independent fields allow to greatly overcome cosmic variance. A total of 1742, 637, 515 and 556 Ha emitters are homogeneously selected at z=0.40, 0.84, 1.47 and 2.23, respectively, and used to determine the Ha luminosity function and its evolution. The faint-end slope is found to be -1.60+-0.08 over z=0-2.23, showing no evolution. The characteristic luminosity of SF galaxies, L*, evolves significantly as log[L*(z)]=0.45z+log[L*(z=0)]. This is the first time Ha has been used to trace SF activity with a single homogeneous survey at z=0.4-2.23. Over...

Sobral, David; Best, Philip N; Geach, James E; Matsuda, Yuichi; Stott, John P; Cirasuolo, Michele; Kurk, Jaron

2012-01-01

357

Neutron-induced background by an alpha-beam incident on a deuterium gas target and its implications for the study of the 2H(alpha,gamma)6Li reaction at LUNA  

CERN Document Server

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....

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

358

GLACE survey: OSIRIS/GTC Tuneable Filter H$\\alpha$ imaging of the rich galaxy cluster ZwCl 0024.0+1652 at z = 0.395. Part I -- Survey presentation, TF data reduction techniques and catalogue  

CERN Document Server

The cores of clusters at 0 $\\lesssim$ z $\\lesssim$ 1 are dominated by quiescent early-type galaxies, whereas the field is dominated by star-forming late-type ones. Galaxy properties, notably the star formation (SF) ability, are altered as they fall into overdense regions. The critical issues to understand this evolution are how the truncation of SF is connected to the morphological transformation and the responsible physical mechanism. The GaLAxy Cluster Evolution Survey (GLACE) is conducting a study on the variation of galaxy properties (SF, AGN, morphology) as a function of environment in a representative sample of clusters. A deep survey of emission line galaxies (ELG) is being performed, mapping a set of optical lines ([OII], [OIII], H$\\beta$ and H$\\alpha$/[NII]) in several clusters at z $\\sim$ 0.40, 0.63 and 0.86. Using the Tunable Filters (TF) of OSIRIS/GTC, GLACE applies the technique of TF tomography: for each line, a set of images at different wavelengths are taken through the TF, to cover a rest fra...

Sánchez-Portal, Miguel; Pérez-Martínez, Ricardo; Cepa, Jordi; García, Ana M Pérez; Domínguez-Sánchez, Helena; Bongiovanni, Ángel; Serra, Ana L; Alfaro, Emilio; Altieri, Bruno; Aragón-Salamanca, Alfonso; Balkowski, Chantal; Biviano, Andrea; Bremer, Malcom; Castander, Francisco; Castañeda, Héctor; Castro-Rodríguez, Nieves; Chies-Santos, Ana L; Coia, Daniela; Diaferio, Antonaldo; Duc, Pierre-Alain; Ederoclite, Alessandro; Geach, James; González-Serrano, Ignacio; Haines, Chris P; McBreen, Brian; Metcalfe, Leo; Oteo, Iván; Pérez-Fournón, Ismael; Poggianti, Bianca; Polednikova, Jana; Ramón-Pérez, Marina; Rodríguez-Espinosa, José M; Santos, Joana S; Smail, Ian; Smith, Graham P; Temporin, Sonia; Valtchanov, Ivan

2015-01-01

359

Equivalent Simplification Method of Micro-Grid  

Directory of Open Access Journals (Sweden)

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.  

Cai Changchun

2013-09-01

360

Equivalence classes of permutations avoiding a pattern  

CERN Document Server

Given a permutation pattern p and an equivalence relation on permutations, we study the corresponding equivalence classes all of whose members avoid p. Four relations are studied: Conjugacy, order isomorphism, Knuth-equivalence and toric equivalence. Each of these produces a known class of permutations or a known counting sequence. For example, involutions correspond to conjugacy, and permutations whose insertion tableau is hook-shaped with 2 in the first row correspond to Knuth-equivalence. These permutations are equinumerous with certain congruence classes of graph endomorphisms. In the case of toric equivalence we find a class of permutations that are counted by the Euler totient function, with a subclass counted by the number-of-divisors function. We also provide a new symmetry for bivincular patterns that produces some new non-trivial Wilf-equivalences

Ulfarsson, Henning

2010-01-01

361

Research on Fairway Width Design in Curved Bridge Waters Channel  

Directory of Open Access Journals (Sweden)

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.

Chi Hong-Fu

2013-01-01

362

The attenuation of the neutron dose equivalent in a labyrinth through an accelerator shielding  

International Nuclear Information System (INIS)

The attenuation of the neutron dose equivalent in concrete labyrinths with rectangular bends is studied by means of neutron sources and rem counters; the number of bends, the length of each section and the width of the labyrinth could be varied. The results of these measurements were compared with the dose attenuation in a labyrinth at the 7-GeV electron synchrotron and with published data from a proton accelerator. An empirical formula for the attenuation of the neutron dose equivalent is presented. (author)

363

Nightside studies of coherent HF Radar spectral width behaviour  

Directory of Open Access Journals (Sweden)

Full Text Available A previous case study found a relationship between high spectral width measured by the CUTLASS Finland HF radar and elevated electron temperatures observed by the EISCAT and ESR incoherent scatter radars in the post-midnight sector of magnetic local time. This paper expands that work by briefly re-examining that interval and looking in depth at two further case studies. In all three cases a region of high HF spectral width (>200 ms-1 exists poleward of a region of low HF spectral width (<200 ms-1. Each case, however, occurs under quite different geomagnetic conditions. The original case study occurred during an interval with no observed electrojet activity, the second study during a transition from quiet to active conditions with a clear band of ion frictional heating indicating the location of the flow reversal boundary, and the third during an isolated sub-storm. These case studies indicate that the relationship between elevated electron temperature and high HF radar spectral width appears on closed field lines after 03:00 magnetic local time (MLT on the nightside. It is not clear whether the same relationship would hold on open field lines, since our analysis of this relationship is restricted in latitude. We find two important properties of high spectral width data on the nightside. Firstly the high spectral width values occur on both open and closed field lines, and secondly that the power spectra which exhibit high widths are both single-peak and multiple-peak. In general the regions of high spectral width (>200 ms-1 have more multiple-peak spectra than the regions of low spectral widths whilst still maintaining a majority of single-peak spectra. We also find that the region of ion frictional heating is collocated with many multiple-peak HF spectra. Several mechanisms for the generation of high spectral width have been proposed which would produce multiple-peak spectra, these are discussed in relation to the data presented here. Since the regions of high spectral width are observed both on closed and open field lines the use of the boundary between low and high spectral width as an ionospheric proxy for the open/closed field line boundary is not a simple matter, if indeed it is possible at all.

Key words. Ionosphere (auroral ionosphere; ionospheric irregularities

E. E. Woodfield

364

Zeta functions and Blow-Nash equivalence  

OpenAIRE

We propose a refinement of the notion of blow-Nash equivalence between Nash function germs, which is an analog in the Nash setting of the blow-analytic equivalence defined by T.-C. Kuo. The new definition is more natural and geometric. Moreover, this equivalence relation still does not admit moduli for a Nash family of isolated singularities. Some previous invariants are no longer invariants for this new relation, however, thanks to a Denef & Loeser formula coming from motiv...

Fichou, Goulwen

2005-01-01

365

Calculation methods for determining dose equivalent  

International Nuclear Information System (INIS)

A series of calculations of neutron fluence as a function of energy in an anthropomorphic phantom was performed to develop a system for determining effective dose equivalent for external radiation sources. critical organ dose equivalents are calculated and effective dose equivalents are determined using ICRP-26 methods. Quality factors based on both present definitions and ICRP-40 definitions are used in the analysis. The results of these calculations are presented and discussed

366

Equivalent Simplification Method of Micro-Grid  

OpenAIRE

The paper concentrates on the equivalent simplification method for the micro-grid system connection into distributed network. The equivalent simplification method proposed for interaction study between micro-grid and distributed network. Micro-grid network, composite load, gas turbine synchronous generation, wind generation are equivalent simplification and parallel connect into the point of common coupling. A micro-grid system is built and three phase and single phase grounded faults are per...

Cai Changchun; Cao Xiangqin

2013-01-01

367

Analytical approach for improving damage equivalence factors  

OpenAIRE

The fatigue design of bridges under variable amplitude traffic loads is not straightforward. To simplify the task, the current Eurocode provisions apply fatigue load model 3 and damage equivalence factors (lambda). However, the fatigue load model and the damage equivalence factors have several shortcomings: (1) the critical span length is defined for limited bridge influence lines, (2) the damage equivalence factors neglect simultaneous presence of several heavy vehicles on bridges, and (3) t...

Maddah, N.; Nussbaumer, A.

2014-01-01

368

Calculation methods for determining dose equivalent  

Energy Technology Data Exchange (ETDEWEB)

A series of calculations of neutron fluence as a function of energy in an anthropomorphic phantom was performed to develop a system for determining effective dose equivalent for external radiation sources. Critical organ dose equivalents are calculated and effective dose equivalents are determined using ICRP-26 (1) methods. Quality factors based on both present definitions and ICRP-40 definitions are used in the analysis. The results of these calculations are presented and discussed. The effective dose equivalent determined using ICRP-26 methods is significantly smaller than the dose equivalent determined by traditional methods. No existing personnel dosimeter or health physics instrument can determine effective dose equivalent. At the present time, the conversion of dosimeter response to dose equivalent is based on calculations for maximal or ''cap'' values using homogeneous spherical or cylindrical phantoms. The evaluated dose equivalent is, therefore, a poor approximation of the effective dose equivalent as defined by ICRP Publication 26. 3 refs., 2 figs., 1 tab.

Endres, G.W.R.; Tanner, J.E.; Scherpelz, R.I.; Hadlock, D.E.

1987-11-01

369

The effect of buffer zone width on biodiversity  

DEFF Research Database (Denmark)

Field margin management for conservation purposes is a way to protect both functional biodiversity and biodiversity per se without considerable economical loss as field margins are less productive. However, the effect of width of the buffer zone on achievable biodiversity gains has received little attention in previous studies. In this paper we report on finding for syrphids, spiders and carabids, three taxonomic groups with different mobility, all important for conservation biological control. For all groups we found an effect of buffer zone width on their density. A buffer width of 6m was the narrowest that consistently promoted a higher abundance or activity of arthropods within the field area (outside the hedge bottom). However, a further increase in buffer width always increased the abundance and activity of arthropods a little more.

Navntoft, SØren; Sigsgaard, Lene

2012-01-01

370

Optical waveguide device with an adiabatically-varying width  

Science.gov (United States)

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.

Watts; Michael R. (Albuquerque, NM), Nielson; Gregory N. (Albuquerque, NM)

2011-05-10

371

Widths of some classes of convex functions and bodies  

International Nuclear Information System (INIS)

We consider classes of uniformly bounded convex functions defined on convex compact bodies in Rd and satisfying a Lipschitz condition and establish the exact orders of their Kolmogorov, entropy, and pseudo-dimension widths in the L1-metric. We also introduce the notions of pseudo-dimension and pseudo-dimension widths for classes of sets and determine the exact orders of the entropy and pseudo-dimension widths of some classes of convex bodies in Rdrelative to the pseudo-metric defined as the d-dimensional Lebesgue volume of the symmetric difference of two sets. We also find the exact orders of the entropy and pseudo-dimension widths of the corresponding classes of characteristic functions in Lp-spaces, 1?p??.

372

Leptonic widths of high excitations in heavy quarkonia  

International Nuclear Information System (INIS)

Agreement with the measured electronic widths of the resonances ?(4040), ?(4415) and ?(11 019) is shown to be obtained if two effects are taken into account: (i) a flattening of the confining potential at distances r ?> 1.2 fm, which gives a drop in the leptonic widths of high excitations of about 10-20%, but does not affect low-lying states, and (ii) switching off the gluon-exchange (GE) interaction for those nS states which have a rms radius rn ?> 1.4 fm. We also show that an exponential type of screening of the GE interaction barely changes the leptonic widths, ?(nS), for n ? 5. The leptonic widths of ?e+e-(?(7S))=0.11 keV and ?(?(5S)) ? 0.54 keV are predicted

373

Possible Gigantic Variations on the Width of Viscoelastic Fingers  

CERN Document Server

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.

Poire, E C; Poire, Eugenia Corvera

2002-01-01

374

Measurement of the two-photon width of the ?'(958)  

International Nuclear Information System (INIS)

Using 203 pb-1 of data collected by the Mark II detector at the SLAC storage ring PEP, we have measured the radiative width of the ?' for quasireal photons. The width is separately measured in the three reactions e+e-?e+e-?0?+?-, ?0???; e+e-?e+e-?0?+?-; ?0??+?-(?0,?); and e+e-?e+e-?0?, giving a statistically weighted average two-photon width of ??'???=4.57±0.25±0.44 keV. As a byproduct of the study of the decay mode ?'???, we also measured the two-photon decay width of the a2(1320) as ?a2(1320)???=1.03±0.13±0.21 keV

375

Estimates for the widths of weighted Sobolev classes  

International Nuclear Information System (INIS)

Estimates for the Kolmogorov widths in the Lq,v-metric of weighted Sobolev classes as well as for the approximation numbers of the corresponding embedding operators are found. Bibliography: 33 titles.

376

SM Higgs decay branching ratios and total Higgs width  

CERN Multimedia

Upper: Higgs decay ratios as a function of Higgs mass. The largest branching ratio is not necessarily the most usefull one. The most usefull ones are gamma gamma bbar ZZ and WW as in those modes latter signal to background ratios can be achieved. Lower: Total Higgs decay width versus Higgs mass. At low masses the natural width is extremely small, thus observability depends on instrumental resolution primarily.

Daniel Denegri

2001-01-01

377

Kinematic Edges with Flavor Oscillation and Non-Zero Widths  

OpenAIRE

Kinematic edges in cascade decays provide a probe of the masses of new particles. In some new physics scenarios the decay chain involves intermediate particles of different flavors that can mix and oscillate. We discuss the implication of such oscillation, and in particular its interplay with the non-zero widths of the particles. We derive explicit formulae for differential decay rates involving both non-zero widths and oscillation, and show that in the case where the mass d...

Grossman, Yuval; Martone, Mario; Robinson, Dean J.

2011-01-01

378

Continuous cast width control using a data mining approach  

OpenAIRE

Twelve per cent chrome ferritic (non-stabilised) stainless steel cast at the continuous caster at Columbus Stainless exhibited notable differences in the width change between consecutive heats. The reason for these differences is related to the fact that the steel is in a dual phase region between austenite and ferrite during the solidification stages of the continuous casting process. A model was developed and is currently used as a production tool to predict the width change of a 12% chr...

Beer, P. G.; Craig, K. J.

2008-01-01

379

Determination of the radiative decay width of the ?c meson  

International Nuclear Information System (INIS)

An analysis of the reaction ????c was performed in five different decay channels of the ?c: KS0K±?F, K+K-?+?-, 2?+2?-, ?? and 2K+2K-. A value ???(?c)=(11.3±4.2) keV was obtained for the radiative decay width by combining the results from the first four channels. Using our result on the two-photon width we also determined the branching ratio for the decay ?c?2K+2K-. (orig.)

380

A direct measurement of W boson decay width  

CERN Document Server

Based on 85 pb$^{-1}$ data of \\ppbar collisions at $\\sqrt{s}=1.8$ \\tev\\ collected using the D{\\O}detector at Fermilab during the 1994-1995 run of the Tevatron, we present a direct measurement of the total decay width of the \\wb\\ boson, $\\Gamma_W$. The width is determined from the transverse mass spectrum in the $W \\to e+\

Abazov, V M; Abdesselam, A; Abolins, M; Abramov, V; Acharya, B S; Adams, D L; Adams, M; Ahmed, S N; Alexeev, G D; Alton, A; Alves, G A; Anderson, E W; Arnoud, Y; Avila, C; Baarmand, M M; Babintsev, V V; Babukhadia, L; Bacon, Trevor C; Baden, A; Baldin, B Yu; Balm, P W; Banerjee, S; Barberis, E; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Bean, A; Beaudette, F; Begel, M; Belyaev, A; Beri, S B; Bernardi, G; Bertram, I; Besson, A; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Bhattacharjee, M; Blazey, G; Blekman, F; Blessing, S; Böhnlein, A; Bozhko, N; Bolton, T A; Borcherding, F; Bos, K; Bose, T; Brandt, A; Breedon, R; Briskin, G; Brock, R; Brooijmans, G; Bross, A; Buchholz, D; Bühler, M; Büscher, V; Burtovoi, V S; Butler, J M; Canelli, F; Carvalho, W; Casey, D; Casilum, Z; Castilla-Valdez, H; Chakraborty, D; Chan, K M; Chekulaev, S V; Cho, D K; Choi, S; Chopra, S; Christenson, J H; Chung, M; Claes, D; Clark, A R; Coney, L; Connolly, B; Cooper, W E; Coppage, D; Crepe-Renaudin, S; Cummings, M A C; Cutts, D; Davis, G A; De, K; De Jong, S J; Demarteau, M; Demina, R; Demine, P; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Doulas, S; Ducros, Y; Dudko, L V; Duensing, S; Duflot, L; Dugad, S R; Duperrin, A; Dyshkant, A; Edmunds, D; Ellison, J; Eltzroth, J T; Elvira, V D; Engelmann, R; Eno, S; Eppley, G; Ermolov, P; Eroshin, O V; Estrada, J; Evans, H; Evdokimov, V N; Fahland, T; Fein, D; Ferbel, T; Filthaut, Frank; Fisk, H E; Fisyak, Yu; Flattum, E; Fleuret, F; Fortner, M; Fox, H; Frame, K C; Fu, S; Fuess, S; Gallas, E; Galjaev, A N; Gao, M; Gavrilov, V; Genik, R J; Genser, K; Gerber, C E; Gershtein, Yu; Gilmartin, R; Ginther, G; Gómez, B; Goncharov, P I; Gordon, H; Goss, L T; Gounder, K; Goussiou, A; Graf, N; Grannis, P D; Green, J A; Greenlee, H; Greenwood, Z D; Grinstein, S; Groer, L; Grünendahl, S; Sen-Gupta, A; Gurzhev, S N; Gutíerrez, G; Gutíerrez, P; Hadley, N J; Haggerty, H; Hagopian, S; Hagopian, V; Hall, R E; Hansen, S; Hauptman, J M; Hays, C; Hebert, C; Hedin, D; Heinmiller, J M; Heinson, A P; Heintz, U; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Huang, Y; Iashvili, I; Illingworth, R; Ito, A S; Jaffré, M; Jain, S; Jesik, R; Johns, K; Johnson, M; Jonckheere, A; Jöstlein, H; Juste, A; Kahl, W; Kahn, S; Kajfasz, E; Kalinin, A M; Karmanov, D; Karmgard, D; Kehoe, R; Khanov, A; Kharchilava, A I; Kim, S K; Klima, B; Knuteson, B; Ko, W; Kohli, J M; Kostritskii, A V; Kotcher, J; Kothari, B; Kotwal, A V; Kozelov, A V; Kozlovskii, E A; Krane, J; Krishnaswamy, M R; Krivkova, P; Krzywdzinski, S; Kubantsev, M A; Kuleshov, S; Kulik, Y; Kunori, S; Kupco, A; Kuznetsov, V E; Landsberg, G L; Lee, W M; Leflat, A; Leggett, C; Lehner, F; Leonidopoulos, C; Li, J; Li, Q Z; Lima, J G R; Lincoln, D; Linn, S L; Linnemann, J; Lipton, R; Lucotte, A; Lueking, L; Lundstedt, C; Luo, C; Maciel, A K A; Madaras, R J; Malyshev, V L; Manankov, V; Mao, H S; Marshall, T; Martin, M I; Mayorov, A A; McCarthy, R; McMahon, T; Melanson, H L; Merkin, M; Merritt, K W; Miao, C; Miettinen, H; Mihalcea, D; Mishra, C S; Mokhov, N V; Mondal, N K; Montgomery, H E; Moore, R W; Mostafa, M; Da Motta, H; Mutaf, Y; Nagy, E; Nang, F; Narain, M; Narasimham, V S; Naumann, N A; Neal, H A; Negret, J P; Nomerotski, A; Nunnemann, T; O'Neil, D; Oguri, V; Olivier, B; Oshima, N; Padley, P; Pan, L J; Papageorgiou, K; Parashar, N; Partridge, R; Parua, N; Paterno, M; Patwa, A; Pawlik, B; Peters, O; Petroff, P; Piegaia, R; Pope, B G; Popkov, E; Prosper, H B; Protopopescu, S D; Przybycien, M B; Qian, J; Raja, R; Rajagopalan, S; Ramberg, E; Rapidis, P A; Reay, N W; Reucroft, S; Ridel, M; Rijssenbeek, M; Rizatdinova, F K; Rockwell, T; Roco, M T; Royon, C; Rubinov, P; Ruchti, R; Rutherfoord, J; Sabirov, B M; Sajot, G; Santoro, A F S; Sawyer, L; Schamberger, R D; Schellman, H; Schwartzman, A; Sen, N; Shabalina, E; Shivpuri, R K; Shpakov, D; Shupe, M; Sidwell, R A; Simák, V; Singh, H; Sirotenko, V I; Slattery, P F; Smith, E; Smith, R P; Snihur, R; Snow, G R; Snow, J; Snyder, S; Solomon, J; Song, Y; Sorin, V; Sosebee, M; Sotnikova, N; Soustruznik, K; Souza, M; Stanton, N R; Steinbruck, G; Stephens, R W; Stoker, D; Stolin, V; Stone, A; Stoyanova, D A; Strang, M A; Strauss, M; Strovink, M; Stutte, L; Sznajder, A; Talby, M; Taylor, W; Tentindo-Repond, S; Tripathi, S M; Trippe, T G; Turcot, A S; Tuts, P M; Vaniev, V; Van Kooten, R; Varelas, N; Vertogradov, L S; Villeneuve-Séguier, F; Volkov, A A; Vorobev, A P; Wahl, H D; Wang, H; Wang, Z M; Warchol, J; Watts, G; Wayne, M; Weerts, H; White, A; White, J T; Whiteson, D; Wijngaarden, D A; Willis, S; Wimpenny, S J; Womersley, J; Wood, D R; Xu, Q; Yamada, R; Yamin, P; Yasuda, T; Yatsunenko, Y A; Yip, K; Youssef, S; Yu, J; Zanabria, M; Zhang, X; Zheng, H; Zhou, B; Zhou, Z; Zielinski, M; Zieminska, D; Zieminski, A; Zutshi, V; Zverev, E G; Zylberstejn, A

2002-01-01

381

Planar waveguide with "twisted" boundary conditions: small width  

OpenAIRE

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 norms, and give the estimates for the rates of convergence. We show that studying the resolvent convergen...

Borisov, D.; Cardone, G.

2011-01-01

382

Correlations for reduced-width amplitudes in 49V  

International Nuclear Information System (INIS)

Measurement of the relative sign of inelastic proton-channel amplitudes permits the determination of amplitude correlations. Data were obtained for 45 5/2+ resonances in 49V. Although the reduced widths in each channel followed a Porter-Thomas distribution, large amplitude correlations were observed. The results are compared with the reduced-width--amplitude distribution of Krieger and Porter. This is the first direct test of the Krieger-Porter distribution

383

Echo width of foam supports used in scattering measurements  

DEFF Research Database (Denmark)

Theoretically and experimentally determined echo widths of dielectric cylinders having circular, triangular, and quadratic cross sections have been compared. The cylinders were made of foam material having a relative dielectric constant of about 1.035. The purpose of the investigation was to find a cross section with a small echo width. The result can be used in selecting a proper support for test objects in backscattering measurement studies.

Appel-Hansen, JØrgen; Solodukhov, V. V.

1979-01-01

384

The width of the giant dipole resonance at finite temperature  

International Nuclear Information System (INIS)

A method is proposed to evaluate the effect of the change of the Fermi sea on the width of the giant dipole resonance at finite temperature. In a schematic model it is found that, indeed, in 208Pb the width increases very sharply up to about T=4 MeV but shows a much weaker variation for higher temperature. (author) 26 refs., 7 figs., 2 tabs

385

Calculation of the Higgs boson decay widths into boson pairs  

International Nuclear Information System (INIS)

The decay widths of the Higgs boson into ??,Z?,ZZ and W+W- are calculated on the one-loop level of the electroweak theory. Exact analytic formulae in terms of complex-valued dilogarithms are obtained. The dependence of the decay widths on the Higgs boson mass and on the top-quark mass are investigated. 12 refs.; 10 figs.; 1 tab

386

Basis-set calculation of Siegert eigenvalues: Partial resonance widths  

International Nuclear Information System (INIS)

The calculation of complex resonance eigenvalues for electron-atom and electron-molecule scattering by discrete-basis-set methods yields total resonance widths directly. The authors show that, as a consequence of the separable nature of the S matrix near a resonance, discrete-basis-set methods may also be used to compute partial widths for resonances in a multichannel problem. The procedure is applied to a model three-channel problem to demonstrate its numerical effectiveness

387

Rossman/Chance Applet Collection: Selecting Histogram Bin-Width  

Science.gov (United States)

This applet demonstrates the impact of data bin width on the display of information in histograms. The user is able to control the bin width and the axes of the histogram with the resultant changes shown immediately. There are two data sets available for use, and the user can edit the data or create new data sets. This is part of a larger collection of applets on statistics from the California Poly San Luis Obispo.

Rossman, Allan; Chance, Beth

2008-09-04

388

Simulation studies on strip width dimension for ICAL  

International Nuclear Information System (INIS)

The aim of this study is to see the influence of strip width on the physics studies for ICAL through its effect on momentum resolution, angle resolution, reconstruction efficiency, charge identification efficiency and shift in the mean of reconstructed energy of the muon and neutrinos. This will also have implications for the quantum of electronics required for the detector. The study has been carried out for single muons and pions considering different strip width dimensions and 5.6 cm iron plate thickness using GEANT4 and the complete ICAL detector geometry. In principle decreasing the strip width should result in an improvement in the resolution for a fixed iron plate thickness. But due to the straggling in moderately thick absorbers the improvement is very small for strip widths between 1.6 cm and 4 cm. However the angle resolution improves marginally for the lower strip width. Hence for an iron plate thickness of 5.6 cm decreasing the strip width does not cause a significant improvement in momentum response

389

Stieltjes-moment-theory technique for calculating resonance width's  

International Nuclear Information System (INIS)

A recently developed method for calculating the widths of atomic and molecular resonances is reviewed. The method is based on the golden-rule definition of the resonance width, GAMMA(E). The method uses only square-integrable, L2, basis functions to describe both the resonant and the non-resonant parts of the scattering wave function. It employs Stieltjes-moment-theory techniques to extract a continuous approximation for the width discrete representation of the background continuum. Its implementation requires only existing atomic and molecular structure codes. Many-electron effects, such as correlation and polarization, are easily incorporated into the calculation of the width via configuration interaction techniques. Once the width, GAMMA(E), has been determined, the energy shift can be computed by a straightforward evaluation of the required principal-value integral. The main disadvantage of the method is that it provides only the total width of a resonance which decays into more than one channel in a multichannel problem. A review of the various aspects of the theory is given first, and then representative results that have been obtained with this method for several atomic and molecular resonances are discussed. 28 references, 3 figures, 4 tables

390

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

CERN Document Server

We present a preliminary measurement of the resonance parameters of the Upsilon(10580) resonance with the BABAR detector at the SLAC PEP-II asymmetric B factory. We measure the total decay width to be (20.7 +- 1.6 +- 2.5) MeV, the partial electronic width to be (0.321 +- 0.017 +- 0.029) kev and the mass to be (10.5793 +- 0.0004 +- 0.0012) GeV.

Aubert, Bernard; Abe, T; Abrams, G S; Adye, T; Ahmed, S; Alam, M S; Albert, J; Aleksan, Roy; Allison, J; Altenburg, D; Andreotti, M; Angelini, C; Anulli, F; Aston, D; Azzolini, V; Baak, M A; Back, J J; Bailey, S; Baldini-Ferroli, R; Band, H R; Banerjee, Sw; Barate, R; Barlow, N R; Barlow, R J; Bartoldus, R; Batignani, G; Bauer, J M; Beck, T W; Behera, P K; Bellini, F; Benayoun, M; Berger, N; Beringer, J; Bernard, D; Berryhill, J W; Best, D; Bettarini, S; Bettoni, D; Bevan, A J; Bhimji, W; Bianchi, F; Biasini, M; Blanc, F; Blaylock, G; Blinov, V E; Bloom, P; Bondioli, M; Bonneaud, G R; Borean, C; Borgland, A W; Bosisio, L; Boutigny, D; Bowerman, D A; Boyarski, A M; Boyd, J T; Bozzi, C; Brandt, T; Brau, B; Brau, J E; Breon, A B; Briand, H; Brigljevic, V; Brochard, F; Brose, J; Brown, C L; Brown, C M; Brown, D; Brown, D N; Bruinsma, M; Brunet, S; Bucci, F; Buchanan, C; Buchmüller, O L; Bugg, W; Bukin, A D; Burchat, Patricia R; Button-Shafer, J; Buzzo, A; Bóna, M; Cahn, R N; Calabrese, R; Calcaterra, A; Calderini, G; Campagnari, C; Capra, R; Carpinelli, M; Cartaro, C; Cavallo, N; Cavoto, G; Chao, M; Charles, E; Chauveau, J; Chen, E; Chen, J C; Chen, S; Cheng, C H; Chevalier, N; Christ, S; Cibinetto, G; Clark, P J; Cochran, J; Cohen-Tanugi, J; Colberg, T; Colecchia, F; Coleman, J P; Contri, R; Convery, M R; Cote-Ahern, D; Cottingham, W N; Coupal, D P; Cowan, G; Cowan, R; Crawley, H B; Cremaldi, L M; Crosetti, G; Dahmes, B; Dallapiccola, C; Danielson, N; Dasu, S; Datta, M; Dauncey, P D; David, P; Davier, M; Davis, C L; Day, C T; De Groot, N; De Nardo, Gallieno; De Sangro, R; Del Buono, L; Del Gamba, V; Del Re, D; Della Ricca, G; Di Lodovico, F; Dickopp, M; Dittongo, S; Donald, M; Dong, D; Dorfan, J; Dorigo, A; Dubitzky, R S; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W M; Dvoretskii, A; Eckmann, R; Edwards, A J; Egede, U; Eichenbaum, A M; Eigen, G; Eisner, A M; Elmer, P; Emery, S; Ernst, J A; Eschenburg, V; Eschrich, I; Fabozzi, F; Faccini, R; Falciai, D; Farbin, A; Ferrarotto, F; Ferroni, F; Field, R C; Finocchiaro, G; Fisher, A; Flack, R L; Flächer, H U; Flood, K T; Ford, K; Ford, W T; Forti, A C; Forti, F; Fortin, D; Franek, B J; Frey, R; Fry, J R; Gabathuler, Erwin; Gabriel, T A; Gaidot, A; Gaillard, J M; Gaillard, J R; Galeazzi, F; Gallo, F; Gamba, D; Gamet, R; Gan, K K; Ganzhur, S F; Gaspero, M; Gatto, C; Geddes, N I; George, S; Gill, M S; Giorgi, M A; Giraud, P F; Gladney, L; Glanzman, T; Godang, R; Goetzen, K; Golubev, V B; Gopal, G P; Gowdy, S J; Grancagnolo, S; Graugès-Pous, E; Green, M G; Grenier, G J; Grenier, P; Gritsan, A V; Grosdidier, G; Groysman, Y; Guo, Q H; Hadavand, H K; Hadig, T; Haire, M; Halyo, V; Hamel de Monchenault, G; Hamon, O; Harrison, P F; Harrison, T J; Hart, P A; Hartfiel, B L; Harton, J L; Hast, C; Hauke, A; Hawkes, C M; Hearty, C; Held, T; Hertzbach, S S; Heusch, C A; Hicheur, A; Hill, E J; Hitlin, D G; Hodgkinson, M C; Honscheid, K; Hrynóva, T; Hu, T; Hufnagel, D; Höcker, A; Innes, W R; Ivanchenko, V N; Izen, J M; Jackson, F; Jackson, P D; Jacobsen, R G; Jawahery, A; Jayatilleke, S M; Jessop, C P; John, M J J; Johnson, J R; Judd, D; Kadel, R W; Kadyk, J; Kagan, H; Karyotakis, Yu; Kass, R; Kay, M; Kelly, M P; Kelsey, M H; Kerth, L T; Khan, A; Kim, H; Kim, P; Kirkby, D; Kitayama, I; Knowles, D J; Koch, H; Kocian, M L; Kofler, R; Kolomensky, Yu G; Koptchev, V B; Kovalskyi, D; Kowalewski, R V; Kozanecki, Witold; Kral, J F; Kravchenko, E A; Krishnamurthy, M; Kroeger, R; Kukartsev, G; Kurup, A; Kutter, P E; Kuznetsova, N; Kyberd, P; La Vaissière, C de; Lacker, H M; Lae, C K; Lafferty, G D; Lamsa, J; Lanceri, L; Lange, D J; Langenegger, U; Langer, M; Lankford, A J; Laplace, S; Latham, T E; Lavin, D; Lazzaro, A; Le Clerc, C; Le Diberder, F R; Lee, S J; Lees, J P; Legendre, M; Leith, D W G S; Lepeltier, V; Leruste, P; Levesque, J A; Levi, M E; Levy, S L; Lewandowski, B; Li, H; Lillard, V; Lista, L; Liu, R; Lo Vetere, M; LoSecco, J M; Lockman, W S; London, G W; Long, O; Lou, X C; Lu, A; Luitz, S; Luppi, E; Lusiani, A; Lutz, A M; Lynch, G; Lynch, H L; Lyon, A J; Lü, C; Lüth, V; MacFarlane, D B; MacKay, C; Macri, M; Mallik, U; Maly, E; Mancinelli, G; Mandelkern, M A; Manfredi, P F; Mangeol, D J J; Marchiori, G; Margoni, M; Marker, C E; Marsiske, H; Martínez-Vidal, F; Mattison, T S; Mayer, B; Mazur, M A; Mazzoni, M A; McKemey, A K; McKenna, J A; McMahon, T R; Meadows, B T; Messner, R; Meyer, T I; Meyer, W T; Miftakov, V; Mihályi, A; Mir, L M; Mohapatra, A K; Mommsen, R K; Monge, M R; Moore, T B; Morandin, M; Morgan, S E; Morganti, M; Morganti, S; Morii, M; Morton, G W; Muheim, F; Müller, D R; Müller-Pfefferkorn, R; Narsky, I; Nash, J A; Nauenberg, U; Neal, H; Negrini, M; Neri, N; Nicholson, H; Nogowski, R; O'Grady, C P; Ocariz, J; Oddone, P J; Ofte, I; Olaiya, E O; Olivas, A; Olsen, J; Onuchin, A P; Orimoto, T J; Otto, S; Ozcan, V E; Paar, H P

2003-01-01

391

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

International Nuclear Information System (INIS)

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 nts 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.)

392

Equivalence in Ventilation and Indoor Air Quality  

Energy Technology Data Exchange (ETDEWEB)

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.

Sherman, Max; Walker, Iain; Logue, Jennifer

2011-08-01

393

Infinite time decidable equivalence relation theory  

CERN Document Server

We introduce an analog of the theory of Borel equivalence relations in which we study equivalence relations that are decidable by an infinite time Turing machine. The Borel reductions are replaced by the more general class of infinite time computable functions. Many basic aspects of the classical theory remain intact, with the added bonus that it becomes sensible to study some special equivalence relations whose complexity is beyond Borel or even analytic. We also introduce an infinite time generalization of the countable Borel equivalence relations, a key subclass of the Borel equivalence relations, and again show that several key properties carry over to the larger class. Lastly, we collect together several results from the literature regarding Borel reducibility which apply also to absolutely Delta_1^2 reductions, and hence to the infinite time computable reductions.

Coskey, Samuel

2009-01-01

394

Overtraining increases the strength of equivalence relations  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english The present study investigated whether overtraining of the conditional discriminations that are the prerequisites of equivalence class formation strengthens the relations among stimuli in an equivalence class. Two groups of college students formed equivalence classes that consisted of faces that exp [...] ressed emotions (A) and arbitrary stimuli (B, C, D, and E). The overtraining group had twice as many training trials as the regular training group. For participants who formed equivalence classes, relational strength was evaluated by the generalization of expressed emotions from the A to the D stimuli, which was measured using a semantic differential. An untrained control group showed semantic differential scores that were positive for happy faces, negative for angry faces, and neutral for the D stimuli. For the experimental groups, the D stimuli, when included in equivalence classes, produced scores that were similar to those produced by the equivalent faces. The overtraining group, however, had average values closer to the values of the faces than the regular training group. These results indicate that the amount of training is an experimental parameter that influences the strength of relations between stimuli that are found to be equivalent in matching-to-sample tests.

Renato, Bortoloti; Naomi Cristina, Rodrigues; Mariéle Diniz, Cortez; Naiene, Pimentel; Julio C. de, Rose.

2013-12-01

395

Geometry of the local equivalence of states  

Energy Technology Data Exchange (ETDEWEB)

We present a description of locally equivalent states in terms of symplectic geometry. Using the moment map between local orbits in the space of states and coadjoint orbits of the local unitary group, we reduce the problem of local unitary equivalence to an easy part consisting of identifying the proper coadjoint orbit and a harder problem of the geometry of fibers of the moment map. We give a detailed analysis of the properties of orbits of 'equally entangled states'. In particular, we show connections between certain symplectic properties of orbits such as their isotropy and coisotropy with effective criteria of local unitary equivalence. (paper)

Sawicki, A; Kus, M, E-mail: assawi@cft.edu.pl, E-mail: marek.kus@cft.edu.pl [Center for Theoretical Physics, Polish Academy of Sciences, Al Lotnikow 32/46, 02-668 Warszawa (Poland)

2011-12-09

396

Geometry of the local equivalence of states  

International Nuclear Information System (INIS)

We present a description of locally equivalent states in terms of symplectic geometry. Using the moment map between local orbits in the space of states and coadjoint orbits of the local unitary group, we reduce the problem of local unitary equivalence to an easy part consisting of identifying the proper coadjoint orbit and a harder problem of the geometry of fibers of the moment map. We give a detailed analysis of the properties of orbits of ‘equally entangled states’. In particular, we show connections between certain symplectic properties of orbits such as their isotropy and coisotropy with effective criteria of local unitary equivalence. (paper)

397

Domain Wall Width in Different Ferroelectrics via Perturbation Route  

Directory of Open Access Journals (Sweden)

Full Text Available The domains are of fundamental interest for engineering a ferroelectric material. The domain wall and its width control the ferroelectric behavior to a great extent. The stability of polarization in the context of Landau-Ginzburg free energy functional has been worked out in a previous work by a perturbation approach, where two limits of domain wall width were estimated within the stability zone and they were also found to correspond well with the data on lithium niobate and lithium tantalate. In the present work, it is shown that this model is valid for a wide range of ferroelectric materials and also for a given ferroelectric, such as lithium niobate with different levels of impurities, which are known to affect the domain wall width.

Pratap C. Ray

2012-05-01

398

Fast Width Detection in Corridor Using Hough Transform  

Directory of Open Access Journals (Sweden)

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.

Mehrdad Javadi

2012-11-01

399

New Measurement of the ?0 radiative decay width.  

Science.gov (United States)

High precision measurements of the differential cross sections for ?0 photoproduction at forward angles for two nuclei, 12C and 208Pb, have been performed for incident photon energies of 4.9-5.5 GeV to extract the ?0??? decay width. The experiment was done at Jefferson Lab using the Hall B photon tagger and a high-resolution multichannel calorimeter. The ?0??? 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 ?(?0???)=7.82±0.14(stat)±0.17(syst)??eV. With the 2.8% total uncertainty, this result is a factor of 2.5 more precise than the current Particle Data Group average of this fundamental quantity, and it is consistent with current theoretical predictions. PMID:21599360

Larin, I; McNulty, D; Clinton, E; Ambrozewicz, P; Lawrence, D; Nakagawa, I; Prok, Y; Teymurazyan, A; Ahmidouch, A; Asratyan, 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, G; 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; Korchin, A; Korsch, W; Kowalski, S; Kubantsev, M; Kubarovsky, V; Li, X; Martel, P; Matveev, V; 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; Vasiliev, A; Vishnyakov, V; Wood, M; Zhou, S

2011-04-22

400

A Diffusive Model for Halo Width Growth During VDEs  

International Nuclear Information System (INIS)

Full text: The electromagnetic loads produced by halo currents during vertical disruption events (VDEs) impose stringent requirements on the strength of ITER in-vessel components. A predictive understanding of halo current evolution is essential for ensuring the robust design of those components. That evolution is primarily governed by two quantities: the halo region width and resistivity. A diffusive model of halo width growth during VDEs has been developed that provides one part of a physics basis for predictive halo current simulations. The diffusive model was motivated by DIII-D observations that VDEs with cold post-thermal quench plasma and a current decay time much faster than the vertical motion (Type I VDE) possess much wider halo region widths than warmer plasma VDEs where the current decay is much slower than the vertical motion (Type II). A 2D finite element code is used to model current diffusion during selected Type I and Type II DIII-D VDEs. The model assumes a core plasma region within the LCFS diffusing current into a halo plasma filling the vessel outside the LCFS. LCFS motion and plasma temperature are prescribed from experimental observations. The halo width evolution produced by this model compares favorably with the experimental measurements of Type I and Type II halo width evolution. A closed-form, 1D model of diffusive halo width growth, which can be more simply integrated into complex simulation codes, is also presented. This work was supportedis also presented. This work was supported by the US Department of Energy under DE-FC02-04ER54698. (author)

401

New parameter in diagnosis of acute appendicitis: Platelet distribution width  

Science.gov (United States)

AIM: To investigate the diagnostic accuracy of the mean platelet volume and platelet distribution width in acute appendicitis. METHODS: This retrospective, case-controlled study compared 295 patients with acute appendicitis (Group?I), 100 patients with other intra-abdominal infections (Group II), and 100 healthy individuals (Group III) between January 2012 and January 2013. The age, gender, and white blood cell count, neutrophil percentage, mean platelet volume, and platelet distribution width values from blood samples were compared among the groups. Statistical analyses were performed using SPSS for Windows 21.0 software. In addition, the sensitivity, specificity, positive and negative predictive values and likelihood ratios, and diagnostic accuracy were calculated. RESULTS: The mean ages of patients were 29.9 ± 12.0 years for Group?I, 31.5 ± 14.0 years for Group II, and 30.4 ± 13.0 years for Group III. Demographic features such as age and gender were not significantly different among the groups. White blood cell count, neutrophil percentage and platelet distribution width were significantly higher in Group?I?compared to groups II and III (P Diagnostically, the sensitivity, specificity and diagnostic accuracy were 73.1%, 94.0%, and 78% for white blood cell count, 70.0%, 96.0%, and 76.0% for neutrophil percentage, 29.5%, 49.0%, and 34.0% for mean platelet volume, and 97.1%, 93.0%, and 96.0% for platelet distribution width, respectively. The highest diagnostic accuracy detected was for platelet distribution width between Group?I?and Group III (P < 0.01). CONCLUSION: Platelet distribution width analysis can be used for diagnosis of acute appendicitis without requiring additional tests, thus reducing the cost and loss of time.

Dinc, Bulent; Oskay, Alten; Dinc, Selcan Enver; Bas, Bilge; Tekin, Sabri

2015-01-01

402

Comprehensive intermaxillary tooth width proportion of Bangkok residents  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Proper occlusion depends on the correct width ratio between upper and lower teeth, known as Bolton's ratio. In fact, this ratio can be calculated for each pair of teeth from the central incisor to the first permanent molar. This set of ratios, known as comprehensive cumulative percentage ratios (CPR [...] s), can be used not only to determine which tooth or teeth have a tooth width discrepancy, but can also enable the partial graphical analysis of tooth width discrepancy when there is agenesis of certain permanent teeth. Although CPRs have been calculated for Caucasians, tooth width is known to vary depending on racial origin. Therefore, a test of differences between racial groups should be carried out. If these ratios of the Caucasians and Bangkokians are significantly different, the ratio of the Bangkokians is recommended. The objective of this study was to measure tooth size disproportion for Thai patients and to calculate a corresponding set of CPRs. Thirty-seven pairs of dental models were made from a group of Bangkok residents with normal occlusion. Mesiodistal tooth width was measured for each model. The intra- and inter-examiner measurement errors were ascertained as insignificant (p > 0.05). CPRs were then calculated and compared to those derived from other studies. Ten of thirteen CPRs were significantly different from corresponding values derived from Caucasians. We conclude that tooth width ratios vary between different racial groups, and therefore that these should be calculated specifically for each patient racial group.

Somchai, Manopatanakul; Narumon, Watanawirun.

2011-04-01

403

Quantum molecular dynamics method with dynamical wavepacket widths  

International Nuclear Information System (INIS)

To extend the quantum molecular dynamics (QMD) to the low energy region, the wavepacket widths were described by the time-dependance variables by introducing variables by introducing the phenomenological Public potential in order to take in approximately the properties of fermion. The properties of the ground state of nucleus (the bond energy and the density distribution) could be reproduced by the extended QMD (EQMD). The results of applying it to the calculation of collision of nucleon with nucleon showed that the wavepacket widths of nucleon expressed by time-dependance variable made increase the reproducibility of the experiments because it was easy to produce nuclear emission and fusion. (S.Y.)

404

Coherent bremsstrahlung and GDR width from 252Cf cold fission  

CERN Document Server

The energy spectrum of the high energy gamma-rays in coincidence with the prompt gamma rays has been measured for the spontaneous fission of 252Cf. The nucleus-nucleus coherent bremsstrahlung of the accelerating fission fragments is observed and the result has been substantiated with a theoretical calculation based on the coulomb acceleration model. The width of the giant dipole resonance (GDR) decay from the excited fission fragments has been extracted for the first time and compared with the thermal shape fluctuation model (TSFM) in the liquid drop formalism. The extracted GDR width is significantly smaller than the predictions of TSFM.

Pandit, Deepak; Bhattacharya, Srijit; Pal, Surajit; De, A; Banerjee, S R

2009-01-01

405

Varying Vector Pulse Width Modulation for Three Phase Inverter  

OpenAIRE

This paper mainly deals with designing a control scheme to eliminate the OFF STATE (T0 state) present in a Space Vector Pulse-Width Modulation; this has been achieved by redesigning the equations for calculating the reference vector of modulating signal (Vref). In widely used Space Vector Pulse Width Modulation Vmax of carrier signal is greater than Vref of modulating signal (except when Vref = Vmax). Thus during this state the drive goes into the OFF STATE (T0 state). T0 States are simila...

Raju J; Kowsalya M

2014-01-01

406

On collisional emission line widths in electron channeling  

International Nuclear Information System (INIS)

Expression for collisional widths of cross section energy levels are obtained withing the frames of study of relativistic electron emission characteristics diring plane channeling. Attention is paid to the necessity of summarizing by finite states and averaging by initial ones. The necessity of potential modification by application of the Doyle-Terner approximation for low r during calculations is shown. The data on emission line widths by axial channeling with an account of influence of crystal atom heat shift correlations and detector response function are presented Numerical calculations and comparison with experimental results are carried out. Fair agreement with the experimental data is achieved

407

Fast Width Detection in Corridor Using Hough Transform  

OpenAIRE

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 determinatio...

Mehrdad Javadi; Mehdi Ebrahimi

2012-01-01

408

Direct measurement of the W boson decay width  

Science.gov (United States)

Based on 85 pb-1 data of pp¯ collisions at (s)=1.8 TeV collected using the DØ detector at Fermilab during the 1994-1995 run of the Tevatron, we present a direct measurement of the total decay width of the W boson ?W. The width is determined from the transverse mass spectrum in the W-->e+?e decay channel and found to be ?W=2.23+0.15- 0.14(stat)+/-0.10(syst) GeV, consistent with the expectation from the standard model.

Abazov, V. M.; Abbott, B.; Abdesselam, A.; Abolins, M.; Abramov, V.; Acharya, B. S.; Adams, D. L.; Adams, M.; Ahmed, S. N.; Alexeev, G. D.; Alton, A.; Alves, G. A.; Anderson, E. W.; Arnoud, Y.; Avila, C.; Baarmand, M. M.; Babintsev, V. V.; Babukhadia, L.; Bacon, T. C.; Baden, A.; Baldin, B.; Balm, P. W.; Banerjee, S.; Barberis, E.; Baringer, P.; Barreto, J.; Bartlett, J. F.; Bassler, U.; Bauer, D.; Bean, A.; Beaudette, F.; Begel, M.; Belyaev, A.; Beri, S. B.; Bernardi, G.; Bertram, I.; Besson, A.; Beuselinck, R.; Bezzubov, V. A.; Bhat, P. C.; Bhatnagar, V.; Bhattacharjee, M.; Blazey, G.; Blekman, F.; Blessing, S.; Boehnlein, A.; Bojko, N. I.; Bolton, T. A.; Borcherding, F.; Bos, K.; Bose, T.; Brandt, A.; Breedon, R.; Briskin, G.; Brock, R.; Brooijmans, G.; Bross, A.; Buchholz, D.; Buehler, M.; Buescher, V.; Burtovoi, V. S.; Butler, J. M.; Canelli, F.; Carvalho, W.; Casey, D.; Casilum, Z.; Castilla-Valdez, H.; Chakraborty, D.; Chan, K. M.; Chekulaev, S. V.; Cho, D. K.; Choi, S.; Chopra, S.; Christenson, J. H.; Chung, M.; Claes, D.; Clark, A. R.; Coney, L.; Connolly, B.; Cooper, W. E.; Coppage, D.; Crépé-Renaudin, S.; Cummings, M. A.; Cutts, D.; Davis, G. A.; de, K.; de Jong, S. J.; Demarteau, M.; Demina, R.; Demine, P.; Denisov, D.; Denisov, S. P.; Desai, S.; Diehl, H. T.; Diesburg, M.; Doulas, S.; Ducros, Y.; Dudko, L. V.; Duensing, S.; Duflot, L.; Dugad, S. R.; Duperrin, A.; Dyshkant, A.; Edmunds, D.; Ellison, J.; Eltzroth, J. T.; Elvira, V. D.; Engelmann, R.; Eno, S.; Eppley, G.; Ermolov, P.; Eroshin, O. V.; Estrada, J.; Evans, H.; Evdokimov, V. N.; Fahland, T.; Fein, D.; Ferbel, T.; Filthaut, F.; Fisk, H. E.; Fisyak, Y.; Flattum, E.; Fleuret, F.; Fortner, M.; Fox, H.; Frame, K. C.; Fu, S.; Fuess, S.; Gallas, E.; Galyaev, A. N.; Gao, M.; Gavrilov, V.; Genik, R. J.; Genser, K.; Gerber, C. E.; Gershtein, Y.; Gilmartin, R.; Ginther, G.; Gómez, B.; Goncharov, P. I.; González Solís, J. L.; Gordon, H.; Goss, L. T.; Gounder, K.; Goussiou, A.; Graf, N.; Grannis, P. D.; Green, J. A.; Greenlee, H.; Greenwood, Z. D.; Grinstein, S.; Groer, L.; Grünendahl, S.; Gupta, A.; Gurzhiev, S. N.; Gutierrez, G.; Gutierrez, P.; Hadley, N. J.; Haggerty, H.; Hagopian, S.; Hagopian, V.; Hall, R. E.; Hansen, S.; Hauptman, J. M.; Hays, C.; Hebert, C.; Hedin, D.; Heinmiller, J. M.; Heinson, A. P.; Heintz, U.; Hildreth, M. D.; Hirosky, R.; Hobbs, J. D.; Hoeneisen, B.; Huang, Y.; Iashvili, I.; Illingworth, R.; Ito, A. S.; Jaffré, M.; Jain, S.; Jesik, R.; Johns, K.; Johnson, M.; Jonckheere, A.; Jöstlein, H.; Juste, A.; Kahl, W.; Kahn, S.; Kajfasz, E.; Kalinin, A. M.; Karmanov, D.; Karmgard, D.; Kehoe, R.; Khanov, A.; Kharchilava, A.; Kim, S. K.; Klima, B.; Knuteson, B.; Ko, W.; Kohli, J. M.; Kostritskiy, A. V.; Kotcher, J.; Kothari, B.; Kotwal, A. V.; Kozelov, A. V.; Kozlovsky, E. A.; Krane, J.; Krishnaswamy, M. R.; Krivkova, P.; Krzywdzinski, S.; Kubantsev, M.; Kuleshov, S.; Kulik, Y.; Kunori, S.; Kupco, A.; Kuznetsov, V. E.; Landsberg, G.; Lee, W. M.; Leflat, A.; Leggett, C.; Lehner, F.; Leonidopoulos, C.; Li, J.; Li, Q. Z.; Lima, J. G.; Lincoln, D.; Linn, S. L.; Linnemann, J.; Lipton, R.; Lucotte, A.; Lueking, L.; Lundstedt, C.; Luo, C.; Maciel, A. K.; Madaras, R. J.; Malyshev, V. L.; Manankov, V.; Mao, H. S.; Marshall, T.; Martin, M. I.; Mayorov, A. A.; McCarthy, R.; McMahon, T.; Melanson, H. L.; Merkin, M.; Merritt, K. W.; Miao, C.; Miettinen, H.; Mihalcea, D.; Mishra, C. S.; Mokhov, N.; Mondal, N. K.; Montgomery, H. E.; Moore, R. W.; Mostafa, M.; da Motta, H.; Mutaf, Y.; Nagy, E.; Nang, F.; Narain, M.; Narasimham, V. S.; Naumann, N. A.; Neal, H. A.; Negret, J. P.; Nomerotski, A.; Nunnemann, T.; O'Neil, D.; Oguri, V.; Olivier, B.; Oshima, N.; Padley, P.; Pan, L. J.; Papageorgiou, K.; Parashar, N.; Partridge, R.; Parua, N.; Paterno, M.; Patwa, A.; Pawlik, B.; Peters, O.; Pétroff, P.; Piegaia, R.; Pope, B. G.; Popkov, E.; Prosper, H. B.; Protopopescu, S.; Przybycien, M. B.; Qian, J.; Raja, R.; Rajagopalan, S.; Ramberg, E.; Rapidis, P. A.; Reay, N. W.; Reucroft, S.; Ridel, M.; Rijssenbeek, M.; Rizatdinova, F.; Rockwell, T.; Roco, M.; Royon, C.; Rubinov, P.; Ruchti, R.; Rutherfoord, J.; Sabirov, B. M.; Sajot, G.; Santoro, A.; Sawyer, L.; Schamberger, R. D.; Schellman, H.; Schwartzman, A.; Sen, N.; Shabalina, E.; Shivpuri, R. K.; Shpakov, D.; Shupe, M.; Sidwell, R. A.; Simak, V.; Singh, H.; Sirotenko, V.; Slattery, P.; Smith, E.; Smith, R. P.; Snihur, R.; Snow, G. R.; Snow, J.; Snyder, S.; Solomon, J.; Song, Y.; Sorín, V.; Sosebee, M.; Sotnikova, N.; Soustruznik, K.; Souza, M.; Stanton, N. R.; Steinbrück, G.; Stephens, R. W.; Stoker, D.; Stolin, V.; Stone, A.; Stoyanova, D. A.; Strang, M. A.; Strauss, M.; Strovink, M.; Stutte, L.; Sznajder, A.; Talby, M.; Taylor, W.; Tentindo-Repond, S.; Tripathi, S. M.; Trippe, T. G.

2002-08-01

409

The width of verbal subgroups in profinite groups  

OpenAIRE

The main result of this thesis is an original proof that every word has finite width in a compact $p$-adic analytic group. The proof we give here is an alternative to Andrei Jaikin-Zapirain's recent proof of the same result, and utilises entirely group-theoretical ideas. We accomplish this by reducing the problem to a proof that every word has finite width in a profinite group which is virtually a polycyclic pro-$p$ group. To obtain this latter result we first establish that such a group...

Simons, Nicholas James; Segal, Daniel

2009-01-01

410

Planar waveguide with ``twisted'' boundary conditions: Small width  

Science.gov (United States)

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, establishes the uniform resolvent convergence in various possible operator norms, and gives 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.

Borisov, Denis; Cardone, Giuseppe

2012-02-01

411

Planar waveguide with "twisted" boundary conditions: small width  

CERN Document Server

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.

Borisov, D

2011-01-01

412

Minor-minimal planar graphs of even branch-width  

CERN Document Server

Let k>0 be an integer, let H be a minor-minimal graph in the projective plane such that every homotopically non-trivial closed curve intersects H at least k times, and let G be the planar double cover of H obtained by lifting G into the universal covering space of the projective plane, the sphere. We prove that G is minor-minimal of branch-width 2k. We also exhibit examples of minor-minimal planar graphs of branch-width 6 that do not arise this way.

Inkmann, Torsten

2010-01-01

413

Efficient algorithms for estimating the width of nearly normal distributions  

International Nuclear Information System (INIS)

Typical physics data samples often conform to Gaussian distributions with admixtures of more slowly varying backgrounds. Under such circumstances the standard deviation is known to be a poor statistical measure of distribution width. As an alternative, the performance of Gini's mean difference is compared with the standard deviation and the mean deviation. Variants which sum over subsets of all possible pairs are shown to have statistical efficiencies comparable to the mean difference and mean deviation but do not require extensive data storage or a priori knowledge of the sample mean. These statistics are reasonable candidates for monitoring the distribution width of a real time data stream. (orig.)

414

Leptonic widths of high excitations in heavy quarkonia  

CERN Document Server

Agreement with the measured electronic widths of the $\\psi(4040)$, $\\psi(4415)$, and $\\Upsilon (11019)$ resonances is shown to be reached if two effects are taken into account: a flattening of the confining potential at large distances and a total screening of the gluon-exchange interaction at $r\\ga 1.2$ fm. The leptonic widths of the unobserved $\\Upsilon(7S)$ and $\\psi(5S)$ resonances: $\\Gamma_{e^+e^-}(\\Upsilon (7S))=0.11$ keV and $\\Gamma(\\psi(5S))\\approx 0.54$ keV are predicted.

Badalian, A M; Bakker, B L G

2004-01-01

415

A New Measurement of the $\\pi^0$ Radiative Decay Width  

OpenAIRE

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 s...

Larin, I.; Mcnulty, D.; Clinton, E.; Ambrozewicz, P.; Lawrence, D.; Nakagawa, I.; Prok, Y.; Teymurazyan, A.; Ahmidouch, A.; Asratyan, A.; Baker, K.; Benton, L.; Bernstein, A. M.; Burkert, V.; Cole, P.

2010-01-01

416

Coherent bremsstrahlung and GDR width from 252Cf cold fission  

International Nuclear Information System (INIS)

The energy spectrum of the high energy ?-rays in coincidence with the prompt ?-rays has been measured for the spontaneous fission of 252Cf. The nucleus-nucleus coherent bremsstrahlung of the accelerating fission fragments is observed and the result has been substantiated with a theoretical calculation based on the Coulomb acceleration model. The width of the giant dipole resonance (GDR) decay from the excited fission fragments has been extracted for the first time and compared with the thermal shape fluctuation model (TSFM) in the liquid drop formalism. The extracted GDR width is significantly smaller than the predictions of TSFM.

417

Fjords in viscous fingering: selection of width and opening angle  

CERN Document Server

Our experiments on viscous fingering of air into oil contained between closely spaced plates reveal two selection rules for the fjords of oil that separate fingers of air. (Fjords are the building blocks of solutions of the zero surface tension Laplacian growth equation.) Experiments in rectangular and circular geometries yield fjords with base widths 1/2 lambda_c, where lambda_c is the most unstable wavelength from a linear stability analysis. Further, fjords open at an angle of 8.0 degrees plus or minus 1.0 degree. These selection rules hold for a wide range of pumping rates and fjord lengths, widths, and directions.

Ristroph, L; Mineev-Weinstein, M B; Swinney, H L; Ristroph, Leif; Thrasher, Matthew; Mineev-Weinstein, Mark B.; Swinney, Harry L.

2005-01-01

418

X-ray line widths and coronal heating  

International Nuclear Information System (INIS)

We present preliminary results of spectroscopy and imaging of a solar active region and flare plasma in soft X-ray emission lines. Observed X-ray line widths in a nonflaring active region are broader than the Doppler width corresponding to the local electron temperature. An analysis of 41 soft X-ray flares within a single active region reveals a preference for flares to occur at locations that already show enhanced X-ray emission and to favor magnetic complexity over high gradient. However, flares do not appear to be directly responsible for the heating and X-ray production of the active regions

419

X-ray line widths and coronal heating  

Science.gov (United States)

Preliminary results of spectroscopy and imaging of a solar active region and flare plasma in soft X-ray emission lines are presented. Observed X-ray line widths in a nonflaring active region are broader than the Doppler width corresponding to the local electron temperature. An analysis of 41 soft X-ray flares within a single active region reveals a preference for flares to occur at locations that already show enhanced X-ray emission and to favor magnetic complexity over high gradient. However, flares do not appear to be directly responsible for the heating and X-ray production of the active regions.

Acton, L. W.; Wolfson, C. J.; Joki, E. G.; Culhane, J. L.; Rapley, C. G.; Bentley, R. D.; Gabriel, A. H.; Phillips, K. J. H.; Hayes, R. W.; Antonucci, E.

1981-01-01

420

X-ray line widths and coronal heating  

Energy Technology Data Exchange (ETDEWEB)

We present preliminary results of spectroscopy and imaging of a solar active region and flare plasma in soft X-ray emission lines. Observed X-ray line widths in a nonflaring active region are broader than the Doppler width corresponding to the local electron temperature. An analysis of 41 soft X-ray flares within a single active region reveals a preference for flares to occur at locations that already show enhanced X-ray emission and to favor magnetic complexity over high gradient. However, flares do not appear to be directly responsible for the heating and X-ray production of the active regions.

Action, L.W.; Culhane, J.L.; Gabriel, A.H.; Wolfson, C.J.; Rapley, C.G.; Phillips, K.J.H.; Antonucci, E.; Bentley, R.D.; Hayes, R.W.; Joki, E.G.; Jordan, C.; Kayat, M.A.; Kent, B.; Leibacher, J.W.; Nobles, R.A.; Parmar, A.N.; Strong, K.T.; Veck, N.J.

1981-03-15

421

Shift adn width of HeII lines  

International Nuclear Information System (INIS)

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.)

422

Fjords in viscous fingering: selection of width and opening scale  

Energy Technology Data Exchange (ETDEWEB)

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.

Mineev-weinstein, Mark [Los Alamos National Laboratory; Ristroph, Leif [UT-AUSTIN; Thrasher, Matthew [UT-AUSTIN; Swinney, Harry [UT-AUSTIN

2008-01-01

423

Dose equivalent index for fast electrons  

International Nuclear Information System (INIS)

Monte Carlo calculations of the deep and shallow dose equivalent index produced by electron beams in the energy region 5-22 MeV have been performed for unidirectional, opposing, rotating and isotropic irradiations of the spherical tissue equivalent phantom. The observed dose maxima are attributed to multiple scattering and range effects and occur in the outer 10 mm shell. The isotropy factor varies from 2.48 at 5 MeV to 1.89 at 22 MeV. The signal of a detector with isotropic response and wall thickness 0.5 g/cm2 is shown to be a suitable measure of dose equivalent index for fast electrons. The average dose equivalent in the spherical phantom is discussed as an alternative concept. (author)

424

Topological equivalence in families of complex polynomials  

CERN Document Server

We show that two polynomials, joined by a continuous family of polynomial functions $f_s \\colon \\mathbb{C}^n \\to \\mathbb{C}$ of constant degree and with isolated singularities, are topologically equivalent if $n\

Bodin, A; Bodin, Arnaud; Tibar, Mihai

2003-01-01

425

Nuclear Regulatory Commission equivalency evaluation report  

International Nuclear Information System (INIS)

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

426

The Economist Interactive: Equivalent Country Comparisons  

Science.gov (United States)

This interactive tools allows the user to learn which countries parallel the states, provinces or territories of the United States, China, India and Brazil and  presents country equivalent data for both GDP and population.

427

Equivalence Principle, Higgs Boson and Cosmology  

Directory of Open Access Journals (Sweden)

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.

Mauro Francaviglia

2013-05-01

428

Bisimulations Meet PCTL Equivalences for Probabilistic Automata  

CERN Document Server

Probabilistic automata (PA) have been successfully applied in the formal verification of concurrent and stochastic systems. Efficient model checking algorithms have been studied, where the most often used logics for expressing properties are based on PCTL and its extension PCTL*. Various behavioral equivalences are proposed for PAs, as a powerful tool for abstraction and compositional minimization for PAs. Unfortunately, the behavioral equivalences are well-known to be strictly stronger than the logical equivalences induced by PCTL or PCTL*. This paper introduces novel notions of strong bisimulation relations, which characterizes PCTL and PCTL* exactly. We also extend weak bisimulations characterizing PCTL and PCTL* without next operator, respectively. Thus, our paper bridges the gap between logical and behavioral equivalences in this setting.

Song, Lei; Godskesen, Jens Chr

2011-01-01

429

Quantum equivalence principle without mass superselection  

International Nuclear Information System (INIS)

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

430

On the equivalence of nonadiabatic fluids  

OpenAIRE

Here we show how an anisotropic fluid in the diffusion limit can be equivalent to an isotropic fluid in the streaming out limit, in spherical symmetry. For a particular equation of state this equivalence is total, from one fluid we can obtain the other and vice versa. A numerical master model is presented, based on a generic equation of state, in which only quantitative differences are displayed between both nonadiabatic fluids. From a deeper view, other difference between f...

Barreto, W.

2010-01-01

431

The teleparallel equivalent of general relativity  

OpenAIRE

A review of the teleparallel equivalent of general relativity is presented. It is emphasized that general relativity may be formulated in terms of the tetrad fields and of the torsion tensor, and that this geometrical formulation leads to alternative insights into the theory. The equivalence with the standard formulation in terms of the metric and curvature tensors takes place at the level of field equations. The review starts with a brief account of the history of teleparal...

Maluf, J. W.

2013-01-01

432

Equivalence of path dependence and gauge dependence  

International Nuclear Information System (INIS)

The equivalence of path dependence and gauge dependence is established by showing that, for every set of the path dependent expansion coefficients of a wavefunction, there exists one identical set of the conventional, gauge dependent expansion coefficients of a wavefunction in another gauge. This equivalence is further demonstrated through simple examples of a quantum particle interacting with a classical radiation field in the dipole approximation. (author)

433

Dark matter and the equivalence principle  

Science.gov (United States)

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.

Frieman, Joshua A.; Gradwohl, Ben-Ami

1993-01-01

434

Dose equivalent rate calculation tool for FBFC  

International Nuclear Information System (INIS)

The authors present the results obtained by a software designed to compute dose equivalent rate for the critical workstations of the FBFC plant in Romans, France, which will have to deal with an uranium more heavily loaded with U232. The uranium spectrum and the ageing time can be varied in order to visualize the evolution of the dose equivalent rate in different locations with respect to the ageing time

435

Ad-nilpotent Ideals and Equivalence Relations  

CERN Document Server

In this paper we study ad-nilpotent ideals of a complex simple Lie algebra $\\ccg$ and their connections with affine Weyl groups and nilpotent orbits. We define a left equivalence relation for ad-nilpotent ideals based on their normalizer and generators, and prove that the equivalence relation is compatible with the left cell structure of affine Weyl group of $\\ccg$ and Lusztig's star operator for type $\\tilde A_{n-1}$.

Fang, Chuying

2008-01-01

436

Gravitational Equivalent Frequency and the Planck Length  

OpenAIRE

The mass equivalency [m*c^2 = h*f] applies to gravitational mass just as to inertial mass. From that, the gravitational mass has a corresponding, associated, equivalent frequency, f. Using that frequency a new result is obtained in which the significance of the Planck Length is clarified. The Planck Length is fundamental to gravitation and in effect supercedes G in that role because it is found that there is operational or mechanical significance to the role of the Planck Le...

Ellman, Roger

2001-01-01

437

Multilingual energy dictionary. [Equivalents in 6 languages  

Energy Technology Data Exchange (ETDEWEB)

This dictionary covers 1600 entries - ranging from oil well to synthetic natural gas and waste heat recovery - that cover both concepts and equipment, providing the equivalents of the most-important energy terms in six languages: English, French, German, Italian, Portuguese, and Spanish. Each term is listed six times - under each language, with all five foreign equivalents - permitting easy translation among all six languages. Separate entries are also given for British and American English where usage differs in the two countries.

Isaacs, A. (ed.)

1981-01-01

438

On the generation of equivalent hamiltonians  

International Nuclear Information System (INIS)

A new approach to the equivalence problem (in phase space) is presented. Given a Hamiltonian describing a system of particles with two degrees of freedom (and the corresponding Hamilton-Jacobi equation), it is shown how to find the most general family of Hamiltonian functions that generates new Hamilton-Jacobi equation with the following (and essential) characteristic, here defined as equivalence: every new solution is also a solution of the original Hamilton-Jacobi equation and vice-versa. (Author)

439

Quantitative and methodological aspects of stimulus equivalence  

OpenAIRE

The number of different ways of linking stimuli in the training phase of a conditional discrimination procedure designed to teach equivalence relations has hitherto been underestimated. An algorithm from graph theory that produces the correct number of such different ways is given. The establishment of equivalence relations requires transitive stimulus control. A misconception in a previous analysis of the conditions necessary for demonstrating transitive stimulus control is indicated. This m...

O Mara, Henry

1991-01-01

440

Equivalent circuit model of radiative heat transfer  

OpenAIRE

Here, we develop a theory of radiative heat transfer based on an equivalent electrical network representation for the hot material slabs in an arbitrary multilayered environment with arbitrary distribution of temperatures and electromagnetic properties among the layers. Our approach is fully equivalent to the known theories operating with the fluctuating current density, while being significantly simpler in analysis and applications. A practical example of the near-infrared ...

Maslovski, Stanislav I.; Simovski, Constantin R.; Tretyakov, Sergei A.

2012-01-01

441

Equivalent Strain in Simple Shear Deformations  

OpenAIRE

We show that simple shear and pure shear form two groups of transformations with different properties. The equivalent strain is viewed as an external control parameter of the deformation process at low homologous temperatures. The von Mises strain satisfies group-theoretic properties of both groups, supporting its use for measuring the equivalent strain. The Hencky strain, on the other hand, does not satisfy the simple shear group properties, implying that it is not appropri...

Beygelzimer, Yan

2013-01-01

442

The Physical Mirror Equivalence for the Local  

Science.gov (United States)

In this paper we consider the total space of the canonical bundle of and we use a proposal by Hosono, together with results of Seidel and Auroux-Katzarkov-Orlov, to deduce the physical mirror equivalence between and the derived Fukaya category of its mirror which assigns the expected central charge to BPS states. By construction, our equivalence is compatible with the mirror map relating the complex and the Kähler moduli spaces and with the computation of Gromov-Witten invariants.

Cacciatori, Sergio Luigi; Compagnoni, Marco; Guerra, Stefano

2015-01-01

443

Wilf Equivalence for the Charge Statistic  

OpenAIRE

Savage and Sagan have recently defined a notion of st-Wilf equivalence for any permutation statistic st and any two sets of permutations $\\Pi$ and $\\Pi'$. In this paper we give a thorough investigation of st-Wilf equivalence for the charge statistic on permutations and use a bijection between the charge statistic and the major index to prove a conjecture of Dokos, Dwyer, Johnson, Sagan and Selsor regarding powers of 2 and the major index.

Killpatrick, Kendra

2012-01-01

444

The effective theory of Borel equivalence relations  

DEFF Research Database (Denmark)

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 ? is above equality on P (?), the power set of ?, and any Borel equivalence relation strictly above equality on the reals is above equality modulo finite on P (?). In this article we examine the effective content of these and related results by studying effectively Borel equivalence relations under effectively Borel reducibility. The resulting structure is complex, even for equivalence relations with finitely many equivalence classes. However use of Kleene's O as a parameter is sufficient to restore the picture from the noneffective setting. A key lemma is that of the existence of two effectively Borel sets of reals, neither of which contains the range of the other under any effectively Borel function; the proof of this result applies Barwise compactness to a deep theorem of Harrington (see [5,16]) establishing for any recursive ordinal ? the existence of ? singletons whose ?-jumps are Turing incomparable. © 2009 Elsevier B.V. All rights reserved.

Fokina, E.B.; Friedman, S.-D.

2010-01-01

445

On Electrical Equivalence of Aperture-Body and Transmission-Cavity Resonance Phenomena in Subwavelength Conducting Aperture Systems from an Equivalent Circuit Point of View  

CERN Document Server

For a narrow slit structure backed by a conducting strip which is taken as a representative example of an aperture-body resonance (ABR) problem, the transmission resonance condition (i.e., condition for maximum power transmission) and the transmission width (i.e., normalized maximum transmitted power through the slit) are found to be the same as those for narrow slit coupling problem in a thick conducting screen, which is designated as a transmission-cavity resonance (TCR) problem. From a viewpoint of equivalent circuit representation for the transmission resonance condition and the funneling mechanism, the ABR and the TCR problems are thought to be essentially of the same nature.

Cho, Young Ki; Kim, Ki Young

2009-01-01

446

Intense AC field driven superlattices with barrier width dimerization  

CERN Document Server

The evolution of two coupled mini-bands, generated by alternating barrier widths dimerization of a superlattice, driven by intense AC fields is investigated. The present model delivers a useful framework for the transition between the analytical high frequency regime and the extreme low frequency limit described by models based on Fukuyama's {\\it et al.} (Phys. Rev. B {\\bf 8}, 5579 (1973)) proposal.

Rivera, P H; Schulz, P A

1999-01-01

447

Pulse-width-modulated servo valve for autopilot system  

Science.gov (United States)

Valve was developed for autopilot wing-lever system and is to be used in light, single-engine aircraft. Valve is controlled by electronic circuit which feeds pulse-width-modulated correction signals to two solenoids. Valve housing is cast from plastic, making it very economical to fabricate.

Garner, H. D.

1974-01-01

448

Track widths of low energy heavy fragments in nuclear emulsion  

International Nuclear Information System (INIS)

At investigations of nucleus-nucleus collisions in nuclear emulsions the charges of the fragments are often needed. In this report charge determinations on stopping fragments are shortly described. The determinations are made using width measurement technique with optical filar micrometer. Some results are discussed. (author)

449

Surface width of the Solid-On-Solid models  

OpenAIRE

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.

Arisue, H.

1997-01-01

450

Leptonic and hadronic decay widths of next quarkonium (ttbar)  

International Nuclear Information System (INIS)

Predictions for the energy spectrum, leptonic and hadronic decay widths of a new heavy quarkonium family zeta(ttbar) of quark mass Msub(Q) approximately equal to 15 GeV, have been made within the context of a plausible universal potential model. (auth.)

451

Sinusoidal and Space Vector Pulse Width Modulation for Inverter  

Directory of Open Access Journals (Sweden)

Full Text Available Inverters inherently have the property of controlling output frequency but the output voltage can’t be varied. Usually to vary output voltage we have to vary supply voltage which is not always possible for this reason PWM techniques gained momentum. Basic aim of PWM technique is to control output voltage and harmonic reduction. Pulse-width modulation (PWM, or pulseduration modulation (PDM, is a commonly used technique for controlling power to inertial electrical devices, made practical by modern electronic power switches. Here we apply PWM techniques like Sinusoidal pulse width modulation (SPWM and Space Vector Pulse width Modulation (SVPWM to inverter and study its performance. In Sinusoidal Pulse width modulation (SPWM we generate the gating signals by comparing a sinusoidal reference signal with a triangular carrier wave. In Space vector Modulation (SVPWM we consider a rotating phased which is obtained by adding all the three voltages. Modulation is accomplished by switching state of an inverter. Thus by comparing these two techniques we study the performance of our inverter.

K. Mounika#1 , B. Kiran Babu

2013-04-01

452

Harmonic Orientation of Pulse Width Modulation Technique in Multilevel Inverters  

Directory of Open Access Journals (Sweden)

Full Text Available The Multilevel Inverter topology gives the advantages of usage in high power and high voltage application with reduced harmonic distortion without a transformer. This paper presents a comparative study of orientation of higher ordered harmonics with increase in switching frequency around the frequency modulation index of nine level diode clamped inverter for different Switching frequency Multicarrier Pulse width Modulation.

Urmila Bandaru

2011-01-01

453

Harmonic Orientation of Pulse Width Modulation Technique in Multilevel Inverters  

OpenAIRE

The Multilevel Inverter topology gives the advantages of usage in high power and high voltage application with reduced harmonic distortion without a transformer. This paper presents a comparative study of orientation of higher ordered harmonics with increase in switching frequency around the frequency modulation index of nine level diode clamped inverter for different Switching frequency Multicarrier Pulse width Modulation.

Urmila Bandaru; Rayudu, Subba D.

2011-01-01

454

Measurement of the radiative width of the K+(890)  

International Nuclear Information System (INIS)

Coherent production of K? systems observed in excitation of 200-GeV/c positive kaons on nuclear targets has been analyzed, including both electromagnetic and strong contributions, to yield a new value for the radiative width for the process K/sup asterisk+/(890)?K+#betta# of 51 +- 5 keV

455

The width of gamma-ray burst spectra  

CERN Document Server

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...

Axelsson, Magnus

2014-01-01

456

Frequency Dependence of Pulse Width for 150 Radio Normal Pulsars  

Science.gov (United States)

The frequency dependence of the pulse width is studied for 150 normal pulsars, mostly selected from the European Pulsar Network, for which the 10% multifrequency pulse widths can be well fit with the Thorsett relationship W 10 = A?? + W 10, min. The relative fraction of pulse width change between 0.4 GHz and 4.85 GHz, ? = (W 4.85 - W 0.4)/W 0.4, is calculated in terms of the best-fit relationship for each pulsar. It is found that 81 pulsars (54%) have ? 10% (group C), showing a remarkable profile broadening at high frequencies. The fractions of the group-A and group-C pulsars suggest that the profile narrowing phenomenon at high frequencies is more common than the profile broadening phenomenon, but a large fraction of the group-B and group-C pulsars (a total of 46%) is also revealed. The group-C pulsars, together with a portion of group-B pulsars with slight pulse broadening, can hardly be explained using the conventional radius-to-frequency mapping, which only applies to the profile narrowing phenomenon. Based on a recent version of the fan beam model, a type of broadband emission model, we propose that the diverse frequency dependence of pulse width is a consequence of different types of distribution of emission spectra across the emission region. The geometrical effect predicting a link between the emission beam shrinkage and spectrum steepening is tested but disfavored.

Chen, J. L.; Wang, H. G.

2014-11-01

457

Quark mass differences, magnetic moments, and radiative decay widths  

International Nuclear Information System (INIS)

Magnetic moments and transition moments of charmed hadrons and radiative decay widths of ordinary and charmed vector mesons have been calculated using quark masses consistent with the gauge model of weak, electromagnetic, and strong interactions of De Rujula, Georgi, and Glashow

458

Masses and widths of strange baryon resonances in QCD  

International Nuclear Information System (INIS)

An analytic calculation of masses and widths of light quark baryonic resonances based on QCD is highly desirable. QCD sum rule method, having close contact with the basic premise of QCD and having a minimal model dependence with well-understood limitations, can serve as a complement to lattice QCD

459

Improved determination of the width of the top quark  

Energy Technology Data Exchange (ETDEWEB)

We present an improved determination of the total width of the top quark, {Gamma}{sub t}, using 5.4 fb{sup -1} of integrated luminosity collected by the D0 Collaboration at the Tevatron p{bar p} Collider. The total width {Gamma}{sub t} is extracted from the partial decay width {Gamma}(t {yields} Wb) and the branching fraction {Beta}(t {yields} Wb). {Gamma}(t {yields} Wb) is obtained from the t-channel single top-quark production cross section and {Beta}(t {yields} Wb) is measured in t{bar t} events. For a top mass of 172.5 GeV, the resulting width is {Gamma}{sub t} = 2.00{sub -0.43}{sup +0.47} GeV. This translates to a top-quark lifetime of {tau}{sub t} = (3.29{sub -0.63}{sup +0.90}) x 10{sup -25} s. We also extract an improved direct limit on the Cabibbo-Kobayashi-Maskawa quark-mixing matrix element 0.81 < |V{sub tb}| {le} 1 at 95% C.L. and a limit of |V{sub tb}| < 0.59 for a high-mass fourth-generation bottom quark assuming unitarity of the fourth-generation quark-mixing matrix.

Abazov V. M.; Abbott B.; Acharya B. S.; Adams M.; Adams T.; Alexeev G. D.; Alkhazov G.; Alton A.; Alverson G.; Aoki M.; Askew A.; Asman B.; Atkins S.; Atramentov O.; Augsten K.; Avila C.; BackusMayes J.; Badaud F.; Bagby L.; Baldin B.; Bandurin D. V.; Banerjee S.; Barberis E.; Baringer P.; Barreto J.; Bartlett J. F.; Bassler U.; Bazterra V.; Bean A.; Begalli M.; Belanger-Champagne C.; Bellantoni L.; Beri S. B.; Bernardi G.; Bernhard R.; Bertram I.; Besancon M.; Beuselinck R.; Bezzubov V. A.; Bhat P. C.; Bhatia S.; Bhatnagar V.; Blazey G.; Blessing S.; Bloom K.; Boehnlein A.; Boline D.; Boos E. E.; Borissov G.; Bose T.; Brandt A.; Brandt O.; Brock R.; Brooijmans G.; Bross A.; Brown D.; Brown J.; Bu X. B.; Buehler M.; Buescher V.; Bunichev V.; Burdin S.; Burnett T. H.; Buszello C. P.; Calpas B.; Camacho-Perez E.; Carrasco-Lizarraga M. A.; Casey C. K.; Castilla-Valdez H.; Chakrabarti S.; Chakraborty D.; Chan M.; Chandra A.; Chapon E.; Chen G.; Chevalier-Thery S.; Cho D. K.; Cho S. W.; Choi S.; Choudhary B.; Cihangir S.; Claes D.; Clutter J.; Cooke M.; Cooper W. E.; Corcoran M.; Couderc F.; Cousinou M. -C.; Croc A.; Cutts D.; Das A.; Davies G.; de Jong S. J.; De La Cruz-Burelo E.; Deliot F.; Demina R.; Denisov D.; Denisov S. P.; Desai S.; Deterre C.; DeVaughan K.; Diehl H. T.; Diesburg M.; Ding P. F.; Dominguez A.; Dorland T.; Dubey A.; Dudko L. V.; Duggan D.; Duperrin A.; Dutt S.; Dyshkant A.; Eads M.; Edmunds D.; Ellison J.; Elvira V. D.; Enari Y.; Evans H.; Evdokimov A.; Evdokimov V. N.; Facini G.; Ferbel T.; Fiedler F.; Filthaut F.; Fisher W.; Fisk H. E.; Fortner M.; Fox H.; Fuess S.; Garcia-Bellido A.; Garcia-Guerra G. A.; Gavrilov V.; Gay P.; Geng W.; Gerbaudo D.; Gerber C. E.; Gershtein Y.; Ginther G.; Golovanov G.; Goussiou A.; Graf C. P.; Grannis P. D.; Greder S.; Greenlee H.; Greenwood Z. D.; Gregores E. M.; Grenier G.; Gris Ph.; Grivaz J. -F.; Grohsjean A.; Gruenendahl S.; Gruenewald M. W.; Guillemin T.; Gutierrez G.; Gutierrez P.; Haas A.; Hagopian S.; Haley J.; Han L.; Harder K.; Harel A.; Hauptman J. M.; Hays J.; Head T.; Hebbeker T.; Hedin D.; Hegab H.; Heinson A. P.; Heintz U.; Hensel C.; La Cruz I. Heredia-De; Herner K.; Hesketh G.; Hildreth M. D.; Hirosky R.; Hoang T.; Hobbs J. D.; Hoeneisen B.; Hohlfeld M.; Hubacek Z.; Hynek V.; Iashvili I.; Ilchenko Y.; Illingworth R.; Ito A. S.; Jabeen S.; Jaffre M.; Jamin D.; Jayasinghe A.; Jesik R.; Johns K.; Johnson M.; Jonckheere A.; Jonsson P.; Joshi J.; Jung A. W.; Juste A.; Kaadze K.; Kajfasz E.; Karmanov D.; Kasper P. A.; Katsanos I.; Kehoe R.; Kermiche S.; Khalatyan N.; Khanov A.; Kharchilava A.; Kharzheev Y. N.; Kohli J. M.; Kozelov A. V.; Kraus J.; Kulikov S.; Kumar A.; Kupco A.; Kurca T.; Kuzmin V. A.; Lammers S.; Landsberg G.; Lebrun P.; Lee H. S.; Lee S. W.; Lee W. M.; Lellouch J.; Li H.; Li L.; Li Q. Z.; Lietti S. M.; Lim J. K.; Lincoln D.; Linnemann J.; Lipaev V. V.; Lipton R.; Liu Y.; Lobodenko A.; Lokajicek M.; de Sa R. Lopes; Lubatti H. J.; Luna-Garcia R.; Lyon A. L.; Maciel A. K. A.; Mackin D.; Madar R.; Magana-Villalba R.; Malik S.; Malyshev V. L.; Maravin Y.; Martinez-Ortega J.; McCarthy R.; McGivern C. L.; Meijer M. M.; Melnitchouk A.; Menezes D.; Mercadante P. G.; Merkin M.; et al.

2012-05-04

460

Estimation of the Beam Width in Magnetic Mass Spectrometer  

Directory of Open Access Journals (Sweden)

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.

O.N. Peregudov

2010-01-01

461

Estimation of the Beam Width in Magnetic Mass Spectrometer  

OpenAIRE

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.

Peregudov, O. N.; Mironetz, E. A.

2010-01-01

462

Relativistic Resonances: their Masses, Widths, Lifetimes, Superposition, and Causal Evolution  

CERN Document Server

Whether one starts form the analytic S-matrix definition or the requirement of gauge parameter independence in renormalization theory, a relativistic resonance is given by a pole at a complex value s of energy squared. The complex number s does not define the mass and width separately and this definition does not lead to interfering Breit-Wigner if two or more resonances are involved. To accomplish both we invoke the decaying particle aspect of a resonance and associate to each pole a space of relativistic Gamow kets which transform irreducibly under causal Poincare transformations. A Gamow state has an exponential time evolution and one can choose of the many possible width parameters, that parameter as the width of the relativistic resonance which equals the inverse lifetime. This uniquely defines the mass and width parameters for a relativistic resonance. Two or more poles in the same partial wave are given by the sum of Breit-Wigners in the scattering amplitude and by a superposition of Gamow vectors with...

Bohm, A R; Bohm, Arno R.; Sato, Yoshihiro

2004-01-01

463

Shifts and widths of Feshbach resonances in atomic waveguides  

CERN Document Server

We develop and analyze a theoretical model which yields the shifts and widths of Feshbach resonances in an atomic waveguide. It is based on a multichannel approach for confinement-induced resonances (CIRs) and atomic transitions in the waveguides in the multimode regime. We replace in this scheme the single-channel scalar interatomic interaction by the four-channel tensorial potential modeling resonances of broad, narrow and overlapping character according to the two-channel parametrization of A.D.Lange et. al. \\cite{Lange}. As an input the experimentally known parameters of Feshbach resonances in the absence of the waveguide are used. We calculate the shifts and widths of s-, d- and g-wave magnetic Feshbach resonances of Cs atoms emerging in harmonic waveguides as CIRs and resonant enhancement of the transmission at zeros of the free space scattering length. We have found the linear dependence of the width of the resonance on the longitudinal atomic momentum and quadratic dependence on the waiveguide width. ...

Saeidian, Shahpoor; Schmelcher, Peter

2012-01-01

464

Backscattering patterns of step index optical fibers: angular width.  

Science.gov (United States)

Angular widths of laser backscattering patterns from optical fibers with thin claddings due to rays reflected by core-cladding interface are investigated. Calculated and measured values are presented and found to be in good agreement. A summary of different backscattering patterns from clad fibers is given. PMID:20155071

Ho, P S; Marhic, M E; Epstein, M

1975-11-01

465

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

CERN Document Server

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 $M = (10579.3\\pm0.4\\pm1.2) {\\rm MeV/c^2}$.

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; S