WorldWideScience

Sample records for h-alpha equivalent width

  1. Spectroscopy of the roAp star Alpha-Cir 2, The bisector and equivalent-width of the H-$\\alpha$ line

    CERN Document Server

    Baldry, I K; Bedding, T R; Kjeldsen, H; Frandsen, S

    1998-01-01

    We present bisector measurements of the H-alpha line of the rapidly oscillating Ap (roAp) star, Alpha-Cir, obtained from dual-site observations with medium-dispersion spectrographs. The velocity amplitude and phase of the principal pulsation mode vary significantly, depending on the height in the H-alpha line, including a phase reversal between the core and the wings of the line. This supports the theory, suggested in Paper I, of a radial pulsational node in the atmosphere of the star. Blending with metal lines partially affects the H-alpha bisector results but probably not enough to explain the phase reversal. We have also detected changes in the equivalent-width of the line during the pulsation, and measured the oscillatory signal as a function of wavelength across the H-alpha region.

  2. Investigating Starburst Galaxy Emission Line Equivalent Widths

    Science.gov (United States)

    Meskhidze, Helen; Richardson, Chris T.

    2016-01-01

    Modeling star forming galaxies with spectral synthesis codes allows us to study the gas conditions and excitation mechanisms that are necessary to reproduce high ionization emission lines in both local and high-z galaxies. Our study uses the locally optimally-emitting clouds model to develop an atlas of starburst galaxy emission line equivalent widths. Specifically, we address the following question: What physical conditions are necessary to produce strong high ionization emission lines assuming photoionization via starlight? Here we present the results of our photoionization simulations: an atlas spanning 15 orders of magnitude in ionizing flux and 10 orders of magnitude in hydrogen density that tracks over 150 emission lines ranging from the UV to the near IR. Each simulation grid contains ~1.5x104 photoionization models calculated by supplying a spectral energy distribution, grain content, and chemical abundances. Specifically, we will be discussing the effects on the emission line equivalent widths of varying the metallicity of the cloud, Z = 0.2 Z? to Z = 5.0 Z?, and varying the star-formation history, using the instantaneous and continuous evolution tracks and the newly released Starburst99 Geneva rotation tracks.

  3. H_alpha emission line morphologies of Markarian starburst galaxies

    OpenAIRE

    Chitre, A.; Joshi, U.C.

    2001-01-01

    We present broad band R and narrow band H_alpha emission line images of a sample of optically selected starburst galaxies from the Markarian lists. The emission line morphology is studied and global properties like luminosities, equivalent widths and star formation rates are derived. The radial distribution of H_alpha flux and the EW are determined using concentric aperture photometry on the emission line and the continuum images. H_alpha flux is generally found to peak in t...

  4. The Photometric and Kinematic Structure of Face-On Disk Galaxies. I. Sample Definition, H-alpha Integral Field Spectroscopy, and HI Line-Widths

    CERN Document Server

    Andersen, D R; Sparke, L S; Gallagher, J S; Wilcots, E M; Van Driel, W; Monnier-Ragaigne, D; Andersen, David R.; Bershady, Matthew A.; Sparke, Linda S.; Gallagher, John S.; Wilcots, Eric M.; Driel, Wim van; Monnier-Ragaigne, Delphine

    2006-01-01

    We present a survey of the photometric and kinematic properties of 39 nearby, nearly face-on disk galaxies. Our approach exploits echelle-resolution integral-field spectroscopy of the H-alpha regions, obtained with DensePak on the WIYN 3.5m telescope Bench Spectrograph. This data is complemented by HI line-profiles observed with the Nancay radio telescope for 25 of these sample galaxies. Twelve additional line-widths are available for sample galaxies from the literature. In this paper, we introduce the goals of this survey, define the sample selection algorithm, and amass the integral field spectroscopic data and HI line-widths. We establish spatially-integrated H-alpha line-widths for the sample. We test the veracity of these spatially-integrated line profiles by convolving narrow-band imaging data with velocity field information for one of the sample galaxies, PGC 38268, and also by comparing to HI line profiles. We find HI and H-alpha line profiles to be similar in width but different in shape, indicating ...

  5. H I Lyman-alpha equivalent widths of stellar populations

    Energy Technology Data Exchange (ETDEWEB)

    Peña-Guerrero, María A.; Leitherer, Claus, E-mail: pena@stsci.edu, E-mail: leitherer@stsci.edu [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

    2013-12-01

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

  6. Non-LTE Equivalent Widths for NII with Error Estimates

    CERN Document Server

    Ahmed, A

    2015-01-01

    Non-LTE calculations are performed for NII in stellar atmospheric models appropriate to main sequence B-stars to produce new grids of equivalent widths for the strongest NII lines commonly used for abundance analysis. There is reasonable agreement between our calculations and previous results, although we find weaker non-LTE effects in the strongest optical NII transition. We also present a detailed estimation of the uncertainties in the equivalent widths due to inaccuracies in the atomic data via Monte Carlo simulation and investigate the completeness of our model atom in terms of included energy levels. Uncertainties in the basic NII atomic data limit the accuracy of abundance determinations to ~+/-0.10 dex at the peak of the NII optical spectrum near Teff~ 24,000 K.

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

    CERN Document Server

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

    1999-01-01

    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.

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

    Scientific Electronic Library Online (English)

    C, Saffe.

    2011-04-01

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

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

    CERN Document Server

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

    2007-01-01

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

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

    CERN Document Server

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

    2012-01-01

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

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

    CERN Document Server

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

    2015-01-01

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

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

    International Nuclear Information System (INIS)

    Highlights: • We apply the equivalent and autocorrelation widths and variance to XPS narrow scans. • This approach is complementary to traditional peak fitting methods. • It is bias free and responsive to subtle chemical changes in spectra. • It has the potential for machine interpretation of spectra and quality control. • It has the potential for analysis of complex spectra and tracking charging/artifacts. - Abstract: X-ray photoelectron spectroscopy (XPS) is widely used in surface and materials laboratories around the world. It is a near surface technique, providing detailed chemical information about samples in the form of survey and narrow scans. To extract the maximum amount of information about materials it is often necessary to peak fit XPS narrow scans. And while indispensable to XPS data analysis, even experienced practitioners can struggle with their peak fitting. In our previous publication, we introduced the equivalent width (EWXPS) as both a possible machine automated method, one that requires less expert judgment for characterizing XPS narrow scans, and as an approach that may be well suited for the analysis of complex spectra. The EWXPS figure of merit was applied to four different data sets. However, as previously noted, other width functions are also regularly employed for analyzing functions. Here we evaluate two other width functions for XPS narrow scan analysis: the autocorrelation width (AWXPS) and the variance (?XPS2). These widths were applied to the same four sets of spectra studied before: (a) four C 1s narrow scans of ozone-treated carbon nanotubes (CNTs) (EWXPS: ?2.11–2.16 eV, AWXPS: ?3.9–4.1 eV, ?XPS2: ?5.0–5.2 eV, and a modified form of ?XPS2, denoted ?XPS2*: ?6.3–6.8 eV), (b) silicon wafers with different oxide thicknesses (EWXPS: ?1.5–2.9 eV, AWXPS: ?2.28–4.9, and ?XPS2: ?0.7–4.9 eV), (iii) hydrogen-terminated silicon surfaces, before and after modification with pentyl groups, and after annealing of the pentyl-terminated surface (EWXPS: ?0.7–1.0 eV, AWXPS: ?1.2–1.6 eV, and ?XPS2: ?0.12–0.19 eV), and (iv) C 1s narrow scans from five different nanodiamond samples, three of which showed charging (EWXPS: ?2.6–4.8 eV, AWXPS: ?3.8–6.9 eV, and ?XPS2: ?1.6–4.2 eV). All three of the width functions showed similar trends, except in the case of the C 1s spectra of the CNT samples, which were the most complex spectra evaluated, where ?XPS2 showed poor correlation with the corresponding O/C ratios. Accordingly, we favor EWXPS and AWXPS. EWXPS is advantageous because it is conceptually simple, giving the most intuitive results. AWXPS has the advantage of not requiring the user to specify the height of the function at its maximum, which will be affected by noise. Because these functions are based on different mathematical operations/algorithms, best practices may involve the calculation of both widths for a set of narrow scans. The standard deviation, ?XPS, i.e., the square root of the variance, was also examined. As expected, it gave results similar to ?XPS2

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

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Bhupinder [Department of Chemistry and Biochemistry, C-100 BNSN, Brigham Young University, Provo, UT 84602 (United States); Velázquez, Daniel; Terry, Jeff [Department of Physics, Illinois Institute of Technology, Chicago, IL 60616 (United States); Linford, Matthew R., E-mail: mrlinford@chem.byu.edu [Department of Chemistry and Biochemistry, C-100 BNSN, Brigham Young University, Provo, UT 84602 (United States)

    2014-12-15

    Highlights: • We apply the equivalent and autocorrelation widths and variance to XPS narrow scans. • This approach is complementary to traditional peak fitting methods. • It is bias free and responsive to subtle chemical changes in spectra. • It has the potential for machine interpretation of spectra and quality control. • It has the potential for analysis of complex spectra and tracking charging/artifacts. - Abstract: X-ray photoelectron spectroscopy (XPS) is widely used in surface and materials laboratories around the world. It is a near surface technique, providing detailed chemical information about samples in the form of survey and narrow scans. To extract the maximum amount of information about materials it is often necessary to peak fit XPS narrow scans. And while indispensable to XPS data analysis, even experienced practitioners can struggle with their peak fitting. In our previous publication, we introduced the equivalent width (EW{sub XPS}) as both a possible machine automated method, one that requires less expert judgment for characterizing XPS narrow scans, and as an approach that may be well suited for the analysis of complex spectra. The EW{sub XPS} figure of merit was applied to four different data sets. However, as previously noted, other width functions are also regularly employed for analyzing functions. Here we evaluate two other width functions for XPS narrow scan analysis: the autocorrelation width (AW{sub XPS}) and the variance (?{sub XPS}{sup 2}). These widths were applied to the same four sets of spectra studied before: (a) four C 1s narrow scans of ozone-treated carbon nanotubes (CNTs) (EW{sub XPS}: ?2.11–2.16 eV, AW{sub XPS}: ?3.9–4.1 eV, ?{sub XPS}{sup 2}: ?5.0–5.2 eV, and a modified form of ?{sub XPS}{sup 2}, denoted ?{sub XPS}{sup 2*}: ?6.3–6.8 eV), (b) silicon wafers with different oxide thicknesses (EW{sub XPS}: ?1.5–2.9 eV, AW{sub XPS}: ?2.28–4.9, and ?{sub XPS}{sup 2}: ?0.7–4.9 eV), (iii) hydrogen-terminated silicon surfaces, before and after modification with pentyl groups, and after annealing of the pentyl-terminated surface (EW{sub XPS}: ?0.7–1.0 eV, AW{sub XPS}: ?1.2–1.6 eV, and ?{sub XPS}{sup 2}: ?0.12–0.19 eV), and (iv) C 1s narrow scans from five different nanodiamond samples, three of which showed charging (EW{sub XPS}: ?2.6–4.8 eV, AW{sub XPS}: ?3.8–6.9 eV, and ?{sub XPS}{sup 2}: ?1.6–4.2 eV). All three of the width functions showed similar trends, except in the case of the C 1s spectra of the CNT samples, which were the most complex spectra evaluated, where ?{sub XPS}{sup 2} showed poor correlation with the corresponding O/C ratios. Accordingly, we favor EW{sub XPS} and AW{sub XPS}. EW{sub XPS} is advantageous because it is conceptually simple, giving the most intuitive results. AW{sub XPS} has the advantage of not requiring the user to specify the height of the function at its maximum, which will be affected by noise. Because these functions are based on different mathematical operations/algorithms, best practices may involve the calculation of both widths for a set of narrow scans. The standard deviation, ?{sub XPS}, i.e., the square root of the variance, was also examined. As expected, it gave results similar to ?{sub XPS}{sup 2}.

  14. The JCMT Nearby Galaxies Legacy Survey VII: H\\alpha{} imaging and massive star formation properties

    CERN Document Server

    Sánchez-Gallego, J R; Wilson, C D; Barmby, P; Azimlu, M; Courteau, S

    2012-01-01

    We present H\\alpha{} fluxes, star formation rates (SFRs) and equivalent widths (EWs) for a sample of 156 nearby galaxies observed in the 12CO J=3-2 line as part of the James Clerk Maxwell Telescope Nearby Galaxies Legacy Survey. These are derived from images and values in the literature and from new H\\alpha{} images for 72 galaxies which we publish here. We describe the sample, observations and procedures to extract the H\\alpha{} fluxes and related quantities. We discuss the SFR properties of our sample and confirm the well-known correlation with galaxy luminosity, albeit with high dispersion. Our SFRs range from 0.1 to 11 Msun yr-1 with a median SFR value for the complete sample of 0.2 Msun yr-1. This median values is somewhat lower than similar published measurements, which we attribute, in part, to our sample being HI-selected and, thus, not biased towards high SFRs as has frequently been the case in previous studies. Additionally, we calculate internal absorptions for the H\\alpha{} line, A(H\\alpha{}), whi...

  15. Non-LTE equivalent widths for N II with error estimates

    Science.gov (United States)

    Ahmed, A.; Sigut, T. A. A.

    2016-01-01

    Non-local thermodynamic equilibrium (non-LTE) calculations are performed for N II in stellar atmospheric models appropriate to main-sequence B stars to produce new grids of equivalent widths for the strongest N II lines commonly used for abundance analysis. There is reasonable agreement between our calculations and previous results, although we find weaker non-LTE effects in the strongest optical N II transition, ?3995. We also present a detailed estimation of the uncertainties in the equivalent widths due to inaccuracies in the atomic data via Monte Carlo simulation and investigate the completeness of our model atom in terms of included energy levels. Uncertainties in the basic N II atomic data limit the accuracy of abundance determinations to ? ±0.10 dex at the peak of the N II optical spectrum near Teff ? 24 000 K.

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

    OpenAIRE

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

    2015-01-01

    We present a Bayesian approach to the redshift classification of emission-line galaxies when only a single emission line is detected spectroscopically. We consider the case of surveys for high-redshift ${\\rm Ly{\\alpha}}$-emitting galaxies (LAEs), which have traditionally been classified via an inferred rest-frame equivalent width $(W_{\\rm Ly\\alpha})$ greater than $20 {\\rm \\,\\AA}$. Our Bayesian method relies on known prior probabilities in measured emission-line luminosity functions and equiva...

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

    CERN Document Server

    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

    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 ...

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

    CERN Document Server

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

    2015-01-01

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

  19. The reddening law of type Ia supernovae: separating intrinsic variability from dust using equivalent widths

    Science.gov (United States)

    Chotard, N.; Gangler, E.; 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.; Nearby Supernova Factory

    2011-05-01

    We employ 76 type Ia supernovae (SNe Ia) 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 the supernovae intrinsic luminosity and determine a dust reddening law. We use the equivalent width of Si ii ?4131 in place of the light curve stretch to account for first-order intrinsic luminosity variability. The resulting empirical spectral reddening law exhibits strong features that are associated with Ca ii and Si ii ?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 to mimic literature observations. After corrections for signatures correlated with Si ii ?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 of the total-to-selective extinction ratio, RV = 2.8 ± 0.3. This agrees with the Milky Way value, in contrast to the low RV values found in most previous analyses. This result suggests that the long-standing controversy in interpreting SN Ia colors and their compatibility with a classical extinction law, which is critical to their use as cosmological probes, can be explained by the treatment of the dispersion in colors, and by the variability of features apparent in SN Ia spectra. Table 1 is available in electronic form at http://www.aanda.org

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

    CERN Document Server

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

    2015-01-01

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

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

    CERN Document Server

    Jennings, Jeff

    2016-01-01

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

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

    DEFF Research Database (Denmark)

    Laursen, Peter; Duval, F.; Östlin, G.

    2013-01-01

    It has been suggested that radiative transfer effects may explain the unusually high equivalent widths (EWs) of the Lya line, observed occasionally from starburst galaxies, especially at high redshifts. If the dust is locked up inside high-density clouds dispersed in an empty intercloud medium, the...... Lya photons could scatter off of the surfaces of the clouds, effectively having their journey confined to the dustless medium. The continuum radiation, on the other hand, does not scatter, and would thus be subject to absorption inside the clouds. This scenario is routinely invoked when Lya EWs higher...... than what is expected theoretically are observed, although the ideal conditions under which the results are derived usually are not considered. Here we systematically examine the relevant physical parameters in this idealized framework, testing whether any astrophysically realistic scenarios may lead...

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

    Science.gov (United States)

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

    2015-02-01

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

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

    OpenAIRE

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

    2006-01-01

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

  5. Star Formation Indicators and Line Equivalent Width in Lyman Alpha Galaxies

    CERN Document Server

    Dijkstra, Mark

    2009-01-01

    The equivalent width (EW) of the Lyman Alpha (Lya) line is directly related to the ratio of star formation rates determined from Lya flux and UV flux density [SFR(Lya)/SFR(UV)]. We use published data --in the literature EW and SFR(Lya)/SFR(UV) are treated as independent quantities-- to show that the predicted relation holds for the vast majority of observed Lya emitting galaxies (LAEs). We show that the relation between EW and SFR(Lya)/SFR(UV) applies irrespective of a galaxy's `true' underlying star formation rate, and that its only source of scatter is the variation in the spectral slope of the UV continuum between individual galaxies. The derived relation, when combined with the observed EW distribution, implies that the ratio SFR(UV)/SFR(Lya) is described well by a log-normal distribution with a standard deviation of ~0.3-0.35. This result is useful when modelling the statistical properties of LAEs. We further discuss why the relation between EW and SFR(Lya)/SFR(UV) may help identifying galaxies with unus...

  6. The equivalent width as a figure of merit for XPS narrow scans

    International Nuclear Information System (INIS)

    Highlights: • We introduce a new figure of merit for XPS narrow scans: the equivalent width (EWXPS). • EWXPS is less subjective and involves lesser user bias than traditional peak fitting. • EWXPS is responsive to changes in chemical states of materials. • EWXPS could be used for quality control and comparing spectra from similar samples. • EWXPS has the potential to be part of an expert software system for machine interpretation of spectra. - Abstract: X-ray Photoelectron Spectroscopy (XPS) is a widely used surface analytical tool that provides information about the near surface regions of materials. And while indispensable for XPS data analysis, peak fitting of narrow scans is often a fairly subjective exercise. Herein we introduce the equivalent width (EW) as an additional and less subjective figure of merit for XPS narrow scans. We believe that this parameter will prove particularly useful for analyzing series of similar or nominally identical spectra, perhaps as a component of an expert software system for the machine interpretation of spectra. It also appears to be useful, shedding light on the chemical state of materials, when additional information about a sample is known. The EWXPS is simply defined as the area of a narrow scan divided by the height of the maximum of its peak envelope. To limit any ambiguity in EWXPS for a series of spectra, we may also list the peak position of the maximum of the envelope (PEmax). The potential usefulness and limitations of the EWXPS and PEmax parameters are demonstrated by their application to the narrow scans of: (i) four sets of ozone-treated carbon nanotubes (EWXPS ? 2.11–2.16 eV for a Shirley background, and up to 2.88 eV for no background, PEmax ? 284.4–284.5 eV), (ii) a series of silicon wafers with different oxide thicknesses (EWXPS ? 1.5–2.8 eV, PEmax ? 99–103 eV), (iii) hydrogen-terminated silicon before and after derivatization with pentyl groups, and after annealing of the pentyl-modified material (EWXPS ? 0.7–1.0 eV, PEmax ? 25.9–26.1 eV), and (iv) five nanodiamond samples, where three of the spectra showed charging (EWXPS ? 2.6–4.9 eV, PEmax ? 272.7–293.9 eV). In this final example, EWXPS was plotted against PEmax to identify the region corresponding to the materials that showed the least charging. EWXPS and PEmax appear to correlate with the expected chemistries of all the systems studied. We calculate EWXPS using a Shirley baseline and with no baseline at all. In setting the baseline limits for EWXPS, we consider the derivative of C 1s narrow scans. We also show the application of EWXPS to single, fitted components within a narrow scan

  7. The equivalent width as a figure of merit for XPS narrow scans

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Bhupinder [Department of Chemistry and Biochemistry, C-100 BNSN, Brigham Young University, Provo, UT 84602 (United States); Velázquez, Daniel [Department of Physics, Illinois Institute of Technology, Chicago, IL 60616 (United States); Terry, Jeff, E-mail: terryj@iit.edu [Department of Physics, Illinois Institute of Technology, Chicago, IL 60616 (United States); Linford, Matthew R., E-mail: mrlinford@chem.byu.edu [Department of Chemistry and Biochemistry, C-100 BNSN, Brigham Young University, Provo, UT 84602 (United States)

    2014-12-15

    Highlights: • We introduce a new figure of merit for XPS narrow scans: the equivalent width (EW{sub XPS}). • EW{sub XPS} is less subjective and involves lesser user bias than traditional peak fitting. • EW{sub XPS} is responsive to changes in chemical states of materials. • EW{sub XPS} could be used for quality control and comparing spectra from similar samples. • EW{sub XPS} has the potential to be part of an expert software system for machine interpretation of spectra. - Abstract: X-ray Photoelectron Spectroscopy (XPS) is a widely used surface analytical tool that provides information about the near surface regions of materials. And while indispensable for XPS data analysis, peak fitting of narrow scans is often a fairly subjective exercise. Herein we introduce the equivalent width (EW) as an additional and less subjective figure of merit for XPS narrow scans. We believe that this parameter will prove particularly useful for analyzing series of similar or nominally identical spectra, perhaps as a component of an expert software system for the machine interpretation of spectra. It also appears to be useful, shedding light on the chemical state of materials, when additional information about a sample is known. The EW{sub XPS} is simply defined as the area of a narrow scan divided by the height of the maximum of its peak envelope. To limit any ambiguity in EW{sub XPS} for a series of spectra, we may also list the peak position of the maximum of the envelope (PE{sub max}). The potential usefulness and limitations of the EW{sub XPS} and PE{sub max} parameters are demonstrated by their application to the narrow scans of: (i) four sets of ozone-treated carbon nanotubes (EW{sub XPS} ? 2.11–2.16 eV for a Shirley background, and up to 2.88 eV for no background, PE{sub max} ? 284.4–284.5 eV), (ii) a series of silicon wafers with different oxide thicknesses (EW{sub XPS} ? 1.5–2.8 eV, PE{sub max} ? 99–103 eV), (iii) hydrogen-terminated silicon before and after derivatization with pentyl groups, and after annealing of the pentyl-modified material (EW{sub XPS} ? 0.7–1.0 eV, PE{sub max} ? 25.9–26.1 eV), and (iv) five nanodiamond samples, where three of the spectra showed charging (EW{sub XPS} ? 2.6–4.9 eV, PE{sub max} ? 272.7–293.9 eV). In this final example, EW{sub XPS} was plotted against PE{sub max} to identify the region corresponding to the materials that showed the least charging. EW{sub XPS} and PE{sub max} appear to correlate with the expected chemistries of all the systems studied. We calculate EW{sub XPS} using a Shirley baseline and with no baseline at all. In setting the baseline limits for EW{sub XPS}, we consider the derivative of C 1s narrow scans. We also show the application of EW{sub XPS} to single, fitted components within a narrow scan.

  8. UV/H-alpha Turmoil

    CERN Document Server

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

    2010-01-01

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

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

    Science.gov (United States)

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

    1982-01-01

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

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

    CERN Document Server

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

    2015-01-01

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

  11. Cloud Modeling of a Network Region in H-alpha

    OpenAIRE

    Bostanci, Z. F.

    2011-01-01

    In this paper, we analyze the physical properties of dark mottles in the chromospheric network using two dimensional spectroscopic observations in H-alpha obtained with the Gottingen Fabry-Perot Spectrometer in the Vacuum Tower Telescope at the Observatory del Teide, Tenerife. Cloud modeling was applied to measure the mottles' optical thickness, source function, Doppler width, and line of sight velocity. Using these measurements, the number density of hydrogen atoms in level...

  12. Temporal evolution of mottles observed in H_alpha

    OpenAIRE

    Bostanci, Z. Funda; Erdogan, Nurol Al

    2007-01-01

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

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

    CERN Document Server

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

    2015-01-01

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

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

    CERN Document Server

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

    2015-01-01

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

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

    CERN Document Server

    Knapen, Johan H

    2009-01-01

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

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

    Science.gov (United States)

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

    2013-01-01

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

  17. Solar Imagery - Chromosphere - H-Alpha

    Data.gov (United States)

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

  18. H-alpha mapping of DDO 53

    International Nuclear Information System (INIS)

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

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

    CERN Document Server

    Aksaker, Naz\\im

    2012-01-01

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

  20. Temporal evolution of mottles observed in H_alpha

    CERN Document Server

    Bostanci, Z F; Erdogan, Nurol Al

    2007-01-01

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

  1. H-alpha Observations of MKW10

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

    Korotin, S. A.; Andrievsky, S. M.; Hansen, C. J.; Caffau, E.; Bonifacio, P.; Spite, M.; Spite, F.; François, P.

    2015-09-01

    Context. We present a grid of computed non-local thermodynamic equilibrium (NLTE) equivalent widths (EW) and NLTE abundance corrections for four Ba ii lines: 4554, 5853, 6141, and 6496 Å. Aims: The grid can be useful in deriving the NLTE barium abundance in stars having parameters in the following ranges: effective temperature from 4000 K to 6500 K, surface gravity log g from 0 to 5, microturbulent velocity 0 km s-1 to 3 km s-1, metallicity [Fe/H] from -2 to +0.5, and [Ba/Fe] from -0.4 to +0.6. The NLTE abundance can be either derived by EW interpolation (using the observed Ba ii line EW) or by using the NLTE correction applied to a previously determined LTE abundance. Methods: Ba ii line equivalent widths and the NLTE corrections were calculated using the updated MULTI code and the Ba ii atomic model that was previously applied to determine the NLTE barium abundance in different types of stars. Results: The grid is available on-line through the web, and we find that the grid Ba NLTE corrections are almost as accurate as direct NLTE profile fitting (to within 0.05-0.08 dex). For the weakest Ba ii line (5853 Å) the LTE abundances almost agree with the NLTE abundances, whereas the other three Ba ii lines, 4554, 6141, and 6496 Å, need NLTE corrections even at the highest metallicities tested here. The 4554 Å line is extremely strong and should not be used for abundance analysis above [Fe/H] = -1. Furthermore, we tested the impact of different model atmospheres and spectrum synthesis codes and found average differences of 0.06 dex and 0.09 dex, respectively, for all four lines. At these metallicities we find an average ?NLTE of ± 0.1 dex for the three useful Ba lines for subsolar cool dwarfs. Tables 4 and 5 are only available at 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/581/A70Appendix A is available in electronic form at http://www.aanda.org

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

    CERN Document Server

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

    2007-01-01

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

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

    CERN Document Server

    Gohil, Raj

    2015-01-01

    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...

  5. Discovery of Massive, Mostly Star Formation Quenched Galaxies with Extremely Large Ly? Equivalent Widths at z ˜ 3

    Science.gov (United States)

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

    2015-08-01

    We report a discovery of six massive galaxies with both extremely large Ly? equivalent widths (EWs) and evolved stellar populations at z ˜ 3. These MAssive Extremely STrong Ly? emitting Objects (MAESTLOs) have been discovered in our large-volume systematic survey for strong Ly? emitters (LAEs) with 12 optical intermediate-band data taken with Subaru/Suprime-Cam in the COSMOS field. Based on the spectral energy distribution fitting analysis for these LAEs, it is found that these MAESTLOs have (1) large rest-frame EWs of EW0 (Ly?) ˜ 100-300 Å, (2) M? ˜ 1010.5-1011.1 M?, and (3) relatively low specific star formation rates of SFR/M? ˜ 0.03-1 Gyr-1. Three of the six MAESTLOs have extended Ly? emission with a radius of several kiloparsecs, although they show very compact morphology in the HST/ACS images, which correspond to the rest-frame UV continuum. Since the MAESTLOs do not show any evidence for active galactic nuclei, the observed extended Ly? emission is likely to be caused by a star formation process including the superwind activity. We suggest that this new class of LAEs, MAESTLOs, provides a missing link from star-forming to passively evolving galaxies at the peak era of the cosmic star formation history. Based on observations with NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555; also based on data collected at the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan; and also based on data products from observations made with ESO Telescopes at the La Silla Paranal Observatory under ESO programme ID 179.A-2005 and on data products produced by TERAPIX and the Cambridge Astronomy Survey Unit on behalf of the UltraVISTA consortium.

  6. Comparison of the Halpha equivalent width of HII regions in a flocculent and a grand design galaxy: possible evidences for IMF variations

    CERN Document Server

    Cedres, B; Tomita, A; Cedres, Bernabe; Cepa, Jordi; Tomita, Akihiko

    2005-01-01

    We present here a study of the Halpha equivalent widths of the flocculent galaxy NGC 4395 and the grand design galaxy NGC 5457. A difference between the mean values of the Halpha equivalent widths for the two galaxies has been found. Several hypotheses are presented in order to explain this difference: differences in age, metallicity, star formation rate, photon leakage and initial mass function. Various tests and Monte Carlo models are used to find out the most probable cause of this difference. The resultsshow that the possible cause for the difference could be a variation in the initial mass function. This difference is such that it seems to favor a fraction of more massive stars in the grand design galaxy when compared with the flocculent galaxy. This could be due to a change of the environmental conditions due to a density wave.

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

    CERN Document Server

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

    2002-01-01

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

  8. Scattered H-alpha light from Galactic dust clouds

    OpenAIRE

    Mattila, K. (Kimmo); Juvela, M.; K Lehtinen

    2006-01-01

    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. ...

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

    CERN Document Server

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

    2004-01-01

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

  10. A Ly? EMITTER WITH AN EXTREMELY LARGE REST-FRAME EQUIVALENT WIDTH OF ?900 Å AT z = 6.5: A CANDIDATE POPULATION III-DOMINATED GALAXY?

    International Nuclear Information System (INIS)

    We have identified a very interesting Ly? emitter (LAE), whose Ly? emission line has an extremely large observed equivalent width of EW0 = 436+422–149 Å, which corresponds to an extraordinarily large intrinsic rest-frame equivalent width of EWint0 = 872+844–298 Å after the average intergalactic absorption correction. The object was spectroscopically confirmed to be a real LAE by its apparent asymmetric Ly? line profile detected at z = 6.538. The continuum emission of the object was definitely detected in our deep z'-band image; thus, its EW0 was reliably determined. Follow-up deep near-infrared spectroscopy revealed emission lines of neither He II ?1640 as an apparent signature of Population III (Pop III) nor C IV ?1549 as proof of an active nucleus. No detection of the short-lived He II ?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 EW0 of the Ly? emission and the upper limit on the EW0 of the He II ?1640 emission can be explained by population synthesis models favoring a very young age less than 2-4 Myr and massive metal-poor (Z –5) or even metal-free stars. The observed large EW0 of Ly? is insufficiently explained by Population I/II synthesis models with Z ? 10–3. 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? EW0, though its significance is still unclear.

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

    CERN Document Server

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

    2015-01-01

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

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

    CERN Document Server

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

    2013-01-01

    The AAO/UKST SuperCOSMOS H-alpha Survey (SHS) of the southern Galactic plane was, when completed in 2003, a powerful new addition to wide-field surveys. It has a combination of areal coverage, spatial resolution and flux sensitivity in a narrow imaging band which still marks it out today as an excellent resource for the astronomical community. The 233 separate fields are available online in digital form, with each field covering 25 square degrees. The SHS has been the motivation for equivalent surveys in the north, and new digital H-alpha surveys now beginning in the south such as VPHAS+. The SHS has been the foundation of many important follow-up discovery projects in the southern sky with the Macquarie/AAO/Strasbourg H-alpha (MASH) planetary nebula project being a particularly successful example. However, the full astrophysical potential of the SHS has been hampered by lack of a clear route to acceptable flux calibration from the base photographic data. We have determined the calibration factors for 170 sep...

  13. H-alpha observations of four novae in M31

    Science.gov (United States)

    Jacoby, G.; Ciardullo, R.; Ford, H.

    1983-01-01

    On-line off-line H-alpha plates of M31's nucleus revealed four bright stellar objects (m sub R being approximately 14.9, 15.0, 15.8, 16.4) within 1.2 kpc of the galaxy center. Spectrophotometric observations made 10 days later showed the stars were novae in the stage of early decline. In the 10 day interval, the H-alpha emission from these novae faded less than a magnitude, despite the fact that their continua had long since faded from view. The high luminosity and long decay time of the H-alpha emission suggest it might make an excellent standard candle for extragalactic distance measurements.

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

    OpenAIRE

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

    2012-01-01

    We report on a search for H-alpha absorption in four exoplanets. Strong features at H-alpha are observed in the transmission spectra of both HD 189733b and HD 209458b. We attempt to characterize and remove the effects of stellar variability in HD 189733b, and along with an empirical Monte Carlo test the results imply a statistically significant transit-dependent feature of (-8.72+/-1.48)x10^-4 integrated over a 16 Angstrom band relative to the adjacent continuum. We interpre...

  15. Broad H$\\alpha$ Wing Formation in the Planetary Nebula IC 4997

    CERN Document Server

    Lee, H W; Lee, Hee-Won; Hyung, Siek

    1999-01-01

    The young and compact planetary nebula IC 4997 is known to exhibit very broad wings with a width exceeding $5000 {\\rm km s^{-1}}$ around H$\\alpha$. We propose that the broad wings are formed through Rayleigh-Raman scattering involving atomic hydrogen, by which Ly$\\beta$ photons with a velocity width of a few $10^2 {\\rm km s^{-1}}$ are converted to optical photons and fill the H$\\alpha$ broad wing region. The conversion efficiency reaches 0.6 near the line center where the scattering optical depth is much larger than 1 and rapidly decreases in the far wings.Assuming that close to the central star there exists an unresolved inner compact core of high density, $n_H\\sim 10^{9-10} {\\rm cm^{-3}}$, we use the photoionization code `CLOUDY' to show that sufficient Ly$\\beta$ photons for scattering are produced. Using a top-hat incident profile for the Ly$\\beta$ flux and a scattering region with a H~I column density $N_{HI}=2\\times 10^{20} {\\rm cm^{-2}}$ and a substantial covering factor, we perform a profile fitting an...

  16. The All-sky Kinematics of Diffuse Galactic H-alpha Emission from WHAM

    Science.gov (United States)

    Eagon, Andrew; Haffner, L. Matthew; Benjamin, Robert A.

    2016-01-01

    WHAM-SS (Wisconsin H-alpha Mapper Sky Survey) is the first all-sky velocity-resolved survey of the faint optical emisison line radiation from the diffuse ionized gas of the Milky Way Galaxy. With an angular resolution of one degree, velocity resolution of 12 km/s, and velocity range of 200 km/s, it allows for the study of the kinematics of the ionized gas across the Galaxy. We present first results on the all-sky velocity distribution of this gas. We show the results of Gaussian decomposition of line profiles as well as first and second moment maps both in the disk and at high latitude, and compare our results with some simple models for the density and velocity field of this gas. As in Haffner et al. (2003), we find that the high-latitude sky is characterized by a low velocity "infall" (toward the plane) in H-alpha, although there are also regions of outflow. We also present the variation in line widths as a function of direction and show how these widths correlate with different structures in the warm ionized medium. This program was supported by NSF Award AST-1108911 (for WHAM) and NSF Award AST-1004881 for the Wisconsin REU program in Astrophysics.

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

    CERN Document Server

    Rutten, R J

    2016-01-01

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

  18. Filament and Flare Detection in H{\\alpha} image sequences

    CERN Document Server

    Riegler, Gernot; Pötzi, Werner; Veronig, Astrid

    2013-01-01

    Solar storms can have a major impact on the infrastructure of the earth. Some of the causing events are observable from ground in the H{\\alpha} spectral line. In this paper we propose a new method for the simultaneous detection of flares and filaments in H{\\alpha} image sequences. Therefore we perform several preprocessing steps to enhance and normalize the images. Based on the intensity values we segment the image by a variational approach. In a final postprecessing step we derive essential properties to classify the events and further demonstrate the performance by comparing our obtained results to the data annotated by an expert. The information produced by our method can be used for near real-time alerts and the statistical analysis of existing data by solar physicists.

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

    CERN Document Server

    Brownsberger, Sasha

    2014-01-01

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

  20. H-alpha emission lines in high-redshift quasars

    International Nuclear Information System (INIS)

    Infrared spectra have been obtained of the H-alpha lines in 18 medium- to high-redshift QSOs and optical spectra taken nearly simultaneously to measure the strong UV line. It is found that the H-alpha line is redshifted by an average of 1000 km/s with respect to the lines from high ionization species such as C IV. Low ionization lines from ions like O I and Mg II are shifted by similar, or slightly smaller, amounts with respect to the high ionization lines. These results are difficult to reconcile with any simple models currently available, including those where dust obscuration is solely responsible for the observed velocity shifts. The similarity between the velocities of H-alpha and Mg II, O I provides some support for models in which the Balmer lines are produced predominantly in a warm H I region, while the Lyman lines arise mainly in a population of optically thin clouds. A velocity separation between the two cloud populations, along with some obscuration, could explain the main features. 25 refs

  1. COMPARISON OF THE DIFFUSE H{alpha} AND FUV CONTINUUM BACKGROUNDS: ON THE ORIGINS OF THE DIFFUSE H{alpha} BACKGROUND

    Energy Technology Data Exchange (ETDEWEB)

    Seon, Kwang-Il; Kim, Il-Joong; Shinn, Jong-Ho; Han, Wonyong [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of); Witt, Adolf [Ritter Astrophysical Research Center, University of Toledo, Toledo, OH 43606 (United States); Edelstein, Jerry [Space Sciences Laboratory, University of California, Berkeley, CA 94702 (United States); Min, Kyoung-Wook, E-mail: kiseon@kasi.re.kr [Korea Advanced Institute of Science and Technology, Daejeon 305-701 (Korea, Republic of)

    2011-12-20

    We compare the diffuse H{alpha} map of our Galaxy with the FUV (1370-1710 A) continuum map. The H{alpha} intensity correlates well with the FUV intensity. The H{alpha}/FUV intensity ratio increases in general with the H{alpha} intensity and the FUV hardness ratio (1370-1520 A to 1560-1710 A), implying that late OB stars may be the main source of the H{alpha} recombination line at high latitudes. The variation of the H{alpha} intensity as a function of the Galactic latitude is also very similar to that of the FUV intensity. The results likely suggest that not only the original radiation sources of the H{alpha} and FUV backgrounds but also the radiative transfer mechanisms responsible for the diffuse backgrounds are largely common. Therefore, we propose a scenario wherein the H{alpha} background at high latitudes is mostly composed of two components, H{alpha} photons produced by in situ recombination at the ionized regions around late OB stars and dust-scattered light of the H{alpha} photons originating from late OB stars.

  2. H-alpha scans of high-velocity clouds

    International Nuclear Information System (INIS)

    No H-alpha emission has been found in a large-aperture Fabry-Perot spectrometer search for spectra toward six high-velocity clouds, down to detection limits of 0.2-0.6 R. The clouds seem to be located in a medium of low density, or high temperature, or both. The data obtained imply an ambient flux of ionizing radiation of less than 0.5-1.3 million photons/sq cm per sec at the clouds; this is less than the estimate of Bregman and Harrington (1986) for the Galactic halo. 30 references

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

    Science.gov (United States)

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

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

  4. Galactic H $\\alpha$ emission and the Cosmic Microwave Background

    CERN Document Server

    Marcelin, M; Bartlett, J G; Valls-Gabaud, D; Blanchard, A

    1998-01-01

    We present observations of Galactic H alpha emission along two declination bands where the South Pole cosmic microwave background experiment reports temperature fluctuations. The high spectral resolution of our Fabry-Perot system allows us to separate the Galactic signal from the much larger local sources of H alpha emission, such as the Earth's geocorona. For the two bands (at declination -62 and -63 degrees), we find a total mean emission of about 1 Rayleigh with variations of about 0.3 R. The variations are within the estimated uncertainty of our total intensity determinations. For an ionized gas at T around 10**4 K, this corresponds to a maximum free-free brightness temperature of less than 10 microK at 30 GHz (K-band). Thus, unless there is a hot gas component with T around 10**6 K, our results imply that there is essentially no free-free contamination of the SP91 (Schuster et al. 1993) and SP94 (Gunderson et al.1995) data sets.

  5. Modeling of hot Jupiter H alpha transmission spectral line

    Science.gov (United States)

    Huang, Chenliang; Arras, Phil; Christie, Duncan

    2016-01-01

    The upper atmosphere of hot Jupiters is subject to the strong stellar radiation field of the host star, which can heat and ionize the gas, as well as excite atoms to higher energy levels. For planets near the parent star, a thick layer of atomic hydrogen may be present, which has now been observed through both Lyman alpha and H alpha absorption of starlight during transit. Motivated by these observations, we revisit the calculations of Christie et al to study the hydrogen level populations in detail, including radiative (de-)excitation, collisional (de-)excitation, collisional ell-mixing processes up to n = 6 states, as well as radiative ionization, recombination and collisional ionization processes. Using theHD 189733b thermal and photoionization equilibrium hydrostatic balance atmosphere model of Christie et al, we find that the 2s state population is dominated by a) creation and destruction channels via np states (n > 2), which was not considered previously, and b) 2s to 2p collisional ?-mixing process, which was treated incorrectly. I will show our modeling of H alpha transit depth observation with new level populations module.

  6. Automatic Selection of H-alpha Emission-Line Galaxies

    Science.gov (United States)

    Lasheras, Oscar Alonso

    1996-06-01

    We have developed a procedure for the automatic selection of emission-line galaxies candidates from the digitization of objective prism plates. This procedure has been applied over two pair of direct and prism plates of the Universidad Complutense de Madrid (UCM) survey, digitized by the fast and high performance microdensitometer MAMA (Machine Automatique a Mesurer pour l'Astronomie) located at the Observatoire de Paris. The plates where obtained with the Schmidt Telescope at Calar Alto Observatory in Almeria (Spain). The instrumental setup used for the acquisition of the prism plates (IIIa-F emulsion and RG630 filter) allows to register the H-alpha +[NII] emission for galaxies up to z <= 0.045. Therefore the criteria developed for the automatic selection of ELGs candidates consist in identifying the H-alpha emission feature in the extracted monodimensional prism spectra. We have noted that there is not a nitid edge to distinguish between the spectra showing the H-alpha line in emission and the rest. Consequently we have studied the residual obtained after the estimation of the continuum and the variation of the slopes calculated over each spectrum in order to identify the line feature. The efficiency of this technique has been tested by comparing the results obtained applying the automatic procedure with those achieved after a careful visual search for the candidates, as performed up to date in the UCM and similar surveys. The results show us that the automatic procedure only ignore very extended and near saturated known galaxies with well resolved emitting regions located at the external regions. Spectroscopic observations of moderate dispersion for the whole set of candidates selected both automatic and visually show that the former has been able, not only to select the 100% of candidates with confirmed emission recognized also by visual means, but also, and what is more important, to identify a 29% more of confirmed ELGs, without lost of efficiency by the increase of spurious identifications. The digitization of the plates has allowed us to measure a set of accurate observational parameters as positions, magnitudes, sizes and redshifts that will permit to perform statistical analysis of this kind of objects before carrying out specific observations with larger telescopes. Since our plates have not sensitometric spots to calculate its characteristic curve, it has been necessary to obtain external calibrations by comparing with calibrated data offered by several catalogs. We have tested that the precision achieved using this method is mainly limited by the accuracy of the different catalog employed. The redshift of the candidates can be derived from the location of the H-alpha line on the prism spectra. Since they have no spectral features to refer the position of the H$\\alpha$ line, the positions of the objects in the direct plate and their transformations to the prism one have been used to provide a reference point which is dependent neither on magnitude, nor on color, nor spatial light distribution. A precision of 0.003 is reached when measuring redshifts by this method. Finally, the comparison of the candidate samples obtained from two plates of our survey covering the same area on the sky allows the study of the selection effects that affects the identification of the H-alpha line in photographic prism plates. The parameter EW X F of the emission H-alpha +[NII] can be used as a threshold that inform us about the unambiguous identification of the emission in the prism spectra, being 10^-13 erg s^-1 cm^-2A the mean value of this parameter for the whole sample of the UCM survey. We have also developed an algorithm to simulate the expected objective-prism spectra for an object by using different instrumental setups. The simulation permits to investigate the different combinations of EW, fluxes and magnitude that allow the detection of the H$\\alpha$ line in the plates and will be used in the near future to predict the expected spectra by the substitution of the photographic emulsion with CCD detectors. (SECTION: D

  7. Flare asymmetry as seen in offband H-alpha filtergrams

    Science.gov (United States)

    Tang, F.

    1983-01-01

    Narrow-band H-alpha filtergrams at + or - 1 A and + or - 2 A from the line center were used to study the asymmetry of flares. Of the 60 flares studied, 92% show red asymmetry while 5% show blue asymmetry. Typically, the filtergrams show a striking dominance of the red wing over the blue wing from onset until late in the decay phase. The difference in intensity of the flare emissions is further augmented by the extensiveness of the emission area in the brighter wing. New kernel-like emissions were often found many minutes after the flare maximum. Spatially, they are displaced from the previous kernels. The late emissions show the same asymmetry as that of the earlier part of the flare.

  8. Solar H-alpha Oscillations from Intensity and Doppler Observations

    CERN Document Server

    Jackiewicz, J

    2013-01-01

    Chromospheric wave activity around flares and filaments has been a research focus for years, and could provide indirect measurements of local conditions that are not otherwise accessible. One interesting observed phenomenon is oscillations in filaments, activated by distant flares and the large-scale waves they produce. Characteristics of these oscillations, such as periods, amplitudes, and lifetimes, can provide unique information about the filament. We measure oscillation properties in flares and filaments from H-alpha chromospheric data using a new method that provides important spatial and frequency content of the dynamics. We apply the method to two flare events where filaments are observed to oscillate and determine their properties. We find strong oscillatory signal in flaring active regions in the chromosphere over a range of frequencies. Two filaments are found to oscillate without any detectable chromospheric wave acting as an activation mechanism. We find that filaments oscillate with periods of te...

  9. The H-alpha light curves of novae in M31

    Science.gov (United States)

    Ciardullo, Robin; Shafter, Allen W.; Ford, Holland C.; Neill, James D.; Shara, Michael M.

    1990-01-01

    H-alpha and B light curves are presented for 11 M31 novae, four of which were well observed near maximum. These data, along with the H-alpha light curves of two Galactic novae, demonstrate that a nova's maximum H-alpha flux occurs days or weeks after its continuum maximum at a monochromatic intensity 1-2 magnitudes above its peak flux in B. Moreover, after this maximum is achieved, a typical nova will radiate a third as many photons in H-alpha as in the entire B bandpass. The most interesting part of a nova's H-alpha light curve, however, is its decline. It is found that, regardless of a nova's speed, its H-alpha decay rate after maximum is almost identical to its decay rate in B. This behavior suggests that most of a nova's optical luminosity during early decline is continuum emission from the nebula, rather than direct radiation from the central source.

  10. Two views of the Andromeda Galaxy H-alpha and far infrared

    Science.gov (United States)

    Devereux, N. A.; Price, R.; Wells, L. A.; Duric, N.

    1994-11-01

    A complete H-alpha image of the Andromeda Galaxy (M31) is presented allowing the first direct measurement of the total H-alpha luminosity which is (7.3 +/- 2.4) x 106 solar luminosity. The H-alpha emission is associated with three morphologically distinct components; a large scale star-forming ring, approximately 1.65 deg in diameter, contributing 66% of the total H-alpha emission, a bright nucleus contributing 6% of the total H-alpha emission with the remaining 28% contributed by a previously unidentified component of extended and filamentary H-alpha emission interior to the star forming ring. The correspondence between the H-alpha image and the Infrared Astronomy Satellite (IRAS) far-infrared high resolution image is striking when both are convolved to a common resolution of 105 arcsec. The close correspondence between the far-infrared and H-alpha images suggests a common origin for the two emissions. The star-forming ring contributes 70% of the far-infrared luminosity of M31. Evidence that the ring emission is energized by high mass stars includes the fact that peaks in the far-infrared emission coincide identically with H II regions in the H-alpha image. In addition, the far-infrared to H-alpha luminosity ratio within the star-forming ring is similar to what one would expect for H II regions powered by stars of spectral types ranging between O9 and B0. The origin of the filamentary H-alpha and far-infrared luminosity interior to the star-forming ring is less clear, but it is almost certainly not produced by high mass stars.

  11. A catalogue of integrated H\\alpha\\ fluxes for ~1100 Galactic planetary nebulae

    CERN Document Server

    Bojicic, I S; Parker, Q A

    2011-01-01

    We present new determinations of the integrated H\\alpha\\ flux for ~1100 Galactic planetary nebulae measured from the Southern H-Alpha Sky Survey Atlas (SHASSA) and its northern counterpart, the Virginia Tech Spectral-Line Survey (VTSS). This catalogue is the largest homogeneous database of its kind, tripling the number of currently available measurements.

  12. The Wisconsin H-Alpha Mapper Sky Survey

    Science.gov (United States)

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

    2016-01-01

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

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

    CERN Document Server

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

    2005-01-01

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

  14. Width issues

    International Nuclear Information System (INIS)

    Current practices at British Columbia Hydro establish right-of-way widths on the basis of Canadian Standards Association (CSA) standards and BC Hydro standards and practices. The CSA sets certain minimum requirements which are increased by BC Hydro engineers to suit local conditions and design or maintenance requirements. As part of a general review of the utility's rights-of-way policies, a task team was established to consider the following issues related to right-of-way width: CSA and BC Hydro standards and practices; future use of rights-of-way by BC Hydro; electromagnetic interference; audible noise; public safety; right-of-way width for underground circuits; incorporation of setbacks in municipal bylaws; legislative approaches; and land use and development. Recommendations for continuation or modification of current practices are made in each of the issue areas. Justifications are provided for the recommendations, along with costs of implementation and alternative options

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

    CERN Document Server

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

    2010-01-01

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

  16. A Correlation between Balmer H-alpha Emission and Infrared Cirrus

    OpenAIRE

    McCullough, Peter R.

    1997-01-01

    A 13x13 degree image of Balmer H-alpha emission at galactic latitude -65 degrees is presented. Sensitivity is limited in part by confusion: the peak-to-valley anisotropy of the H-alpha surface brightness is 0.2 Rayleighs on angular scales of 0.1 to 1.0 degrees. The morphology of the H-alpha emission is similar to that of the 100 um emission previously observed by the Infrared Astronomical Satellite (IRAS). A point-by-point comparison of the two shows a marginally detected (3-sigma) positive c...

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

    CERN Document Server

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

    2011-01-01

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

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

    CERN Document Server

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

    2006-01-01

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

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

    OpenAIRE

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

    2001-01-01

    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.

  20. An H$_\\alpha$ Catalogue of Galaxies in Hickson Compact Groups. I. The Sample

    OpenAIRE

    Severgnini, P .; Garilli, B; Saracco, P.; Chincarini, G.

    1999-01-01

    We present H$_\\alpha$ photometry for a sample of 95 galaxies in Hickson Compact Groups obtained from observations of 31 groups. The Catalogue lists isophotal and adaptive aperture (Kron aperture) flux measurements for about 75% of the accordant galaxies inside the observed HCGs, 22 out of which are upper limits. Non standard data reduction procedures have been used to obtain the continuum subtracted H$_\\alpha$ images for each HCG of the target sample. Flux calibration has al...

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

    CERN Document Server

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

    2015-01-01

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

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

    CERN Document Server

    McCullough, P R

    1997-01-01

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

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

    CERN Document Server

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

    2010-01-01

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

  4. NEBULAR ATTENUATION IN H{alpha}-SELECTED STAR-FORMING GALAXIES AT z = 0.8 FROM THE NewH{alpha} SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Momcheva, Ivelina G. [Astronomy Department, Yale University, New Haven, CT 06511 (United States); Lee, Janice C.; Ouchi, Masami [Carnegie Observatories, Pasadena, CA 91101 (United States); Ly, Chun [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Salim, Samir [Astronomy Department, Indiana University, Bloomington, IN 47405 (United States); Dale, Daniel A. [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States); Finn, Rose [Physics Department, Siena College, Loudonville, NY 12211 (United States); Ono, Yoshiaki, E-mail: ivelina.momcheva@yale.edu [Department of Astronomy, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2013-02-01

    We present measurements of the dust attenuation of H{alpha}-selected emission-line galaxies at z = 0.8 from the NewH{alpha} narrowband survey. The analysis is based on deep follow-up spectroscopy with Magellan/IMACS, which captures the strong rest-frame optical emission lines from [O II] {lambda}3727 to [O III] {lambda}5007. The spectroscopic sample used in this analysis consists of 341 confirmed H{alpha} emitters. We place constraints on the active galactic nucleus (AGN) fraction using diagnostics that can be applied at intermediate redshift. We find that at least 5% of the objects in our spectroscopic sample can be classified as AGNs 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 objects without individual detections. The median attenuation at H{alpha} based on the objects with individually detected lines is A(H{alpha}) = 0.9 {+-} 1.0 mag, in good agreement with the attenuation found in local samples of star-forming galaxies. We find that the z = 0.8 galaxies occupy a similar locus of attenuation as a function of magnitude, mass, and star formation rate (SFR) as a comparison sample drawn from the SDSS DR4. Both the results from the individual z = 0.8 galaxies and from the stacked spectra show consistency with the mass-attenuation and SFR-attenuation relations found in the local universe, indicating that these relations are also applicable at intermediate redshift.

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

    International Nuclear Information System (INIS)

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

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

    CERN Document Server

    Stroe, Andra

    2015-01-01

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

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

    Science.gov (United States)

    Canfield, Richard C.; Gayley, Kenneth G.

    1986-01-01

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

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

    CERN Document Server

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

    2016-01-01

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

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

    CERN Document Server

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

    2015-01-01

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

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

    CERN Document Server

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

    2012-01-01

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

  11. A study of the H-alpha line in X1735 - 444

    Science.gov (United States)

    Smale, Alan P.; Corbet, Robin H. D.

    1991-01-01

    Forty six optical spectra containing the H-alpha line of X1735 - 444, which were obtained over three nights in May 1987, were analyzed. Using a convolution method, a radial velocity curve was derived for the whole H-alpha line. Combining the spectroscopic results with an updated photometric ephemeris, the probable sites for H-alpha emission in X1735 - 444 were determined. Results of the analyses suggest that two distinct regions contribute to the observed profile in X-1735 - 444: (1) the peak emission, which is associated with the accretion stream of material passing between the companion and the compact object; and (2) the base emission, which is produced symmetrically in the outer accretion disk.

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-03-20

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

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

    CERN Document Server

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

    2007-01-01

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

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

    OpenAIRE

    Erroz-Ferrer, Santiago; Knapen, Johan H.; Font, Joan; Beckman, John E.; Falcón-Barroso, Jesús; Sánchez-Gallego, José Ramón; Athanassoula, E.; Bosma, Albert,; Gadotti, Dimitri A.; Muñoz-Mateos, Juan Carlos; Sheth, Kartik; Buta, Ronald J.; Comerón, Sébastien; de Paz, Armando Gil; Hinz, Joannah L.

    2012-01-01

    We present a study of the kinematics of the isolated spiral galaxy NGC 864, using H{\\alpha} Fabry-Perot data obtained with the GH{\\alpha}FaS instrument at the William Herschel Telescope in La Palma, complemented with images at 3.6 {\\mu}m, in the R band and in H{\\alpha} filter, and integral field spectroscopic data. The resulting data cubes and velocity maps allow the study of the kinematics of the galaxy, including in-depth investigations of the rotation curve, velocity mome...

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

    OpenAIRE

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

    2009-01-01

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

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

    OpenAIRE

    Barnes, Joanna E.; Wood,Kenneth; Hill, Alex S.; Haffner, L. Matthew

    2014-01-01

    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 ...

  18. Difference between Spatial Distributions of the H-alpha Kernels and Hard X-Ray Sources in a Solar Flare

    OpenAIRE

    Asai, Ayumi; Masuda, Satoshi; Yokoyama, Takaaki; Shimojo, Masumi; Isobe, Hiroaki; Kurokawa, Hiroki; Shibata, Kazunari

    2002-01-01

    We present the relation of the spatial distribution of H-alpha kernels with the distribution of hard X-ray (HXR) sources seen during the 2001 April 10 solar flare. This flare was observed in H-alpha with the (Sartorius) telescope at Kwasan Observatory, Kyoto University, and in hard X-rays (HXRs) with the Hard X-ray Telescope (HXT) onboard Yohkoh. We compared the spatial distribution of the HXR sources with that of the H-alpha kernels. While many H-alpha kernels are found to brighten successiv...

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

    CERN Document Server

    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

    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...

  20. Anisotropy in broad component of H$\\alpha$ line in the magnetospheric device RT-1

    CERN Document Server

    Kawazura, Yohei; Yoshida, Zensho; Nishiura, Masaki; Nogami, Tomoaki; Kashyap, Ankur; Yano, Yoshihisa; Saitoh, Haruhiko; Yamasaki, Miyuri; Mushiake, Toshiki; Nakatsuka, Masataka

    2016-01-01

    Temperature anisotropy in broad component of H$\\alpha$ line was found in the ring trap 1 (RT-1) device by Doppler spectroscopy. Since hot hydrogen neutrals emitting a broad component are mainly produced by charge exchange between neutrals and protons, the anisotropy in the broad component is the evidence of proton temperature anisotropy generated by betatron acceleration.

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

    CERN Document Server

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

    2014-01-01

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

  2. Giant H$\\alpha$ nebula surrounding the starburst merger NGC 6240

    CERN Document Server

    Yoshida, Michitoshi; Ohyama, Youichi; Komiyama, Yutaka; Kashikawa, Nobunari; Tanaka, Hisashi; Okamura, Sadanori

    2016-01-01

    We revealed the detailed structure of a vastly extended H$\\alpha$-emitting nebula ("H$\\alpha$ nebula") surrounding the starburst/merging galaxy NGC 6240 by deep narrow-band imaging observations with the Subaru Suprime-Cam. The extent of the nebula is $\\sim$90 kpc in diameter and the total H$\\alpha$ luminosity amounts to $\\approx 1.6 \\times 10^{42}$ erg s$^{-1}$. The volume filling factor and the mass of the warm ionized gas are $\\sim$10$^{-4}$--10$^{-5}$ and $\\sim$$5 \\times 10^8$ $M_\\odot$, respectively. The nebula has a complicated structure, which includes numerous filaments, loops, bubbles, and knots. We found that there is a tight spatial correlation between the H$\\alpha$ nebula and the extended soft X-ray-emitting gas, both in large and small scales. The overall morphology of the nebula is dominated by filamentary structures radially extending from the center of the galaxy. A large-scale bi-polar bubble extends along the minor axis of the main stellar disk. The morphology strongly suggests that the nebul...

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

    CERN Document Server

    Dong, Ruobing

    2010-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

  5. Formation of Raman Scattering Wings around H alpha, H beta and Pa alpha in Active Galactic Nuclei

    CERN Document Server

    Chang, Seok-Jun; Di Mille, Francesco; Angeloni, Rodolfo; Palma, Tali; Lee, Hee-Won

    2015-01-01

    Powered by a supermassive black hole with an accretion disk, the spectra of active galactic nuclei (AGNs) are characterized by prominent emission lines including Balmer lines. The unification schemes of AGNs require the existence of a thick molecular torus that may hide the broad emission line region from the view of observers near the equatorial direction. In this configuration, one may expect that the far UV radiation from the central engine can be Raman scattered by neutral hydrogen to reappear around Balmer and Paschen emission lines which can be identified with broad wings. We produce H$\\alpha$, H$\\beta$ and Pa$\\alpha$ wings using a Monte Carlo technique to investigate their properties. The neutral scattering region is assumed to be a cylindrical torus specified by the inner and outer radii and the height. While the covering factor of the scattering region affects the overall strengths of the wings, the wing widths are primarily dependent on the neutral hydrogen column density $N_{\\rm HI}$ being roughly ...

  6. Variations of flaring kernel sizes in various parts of the H-alpha line profile

    CERN Document Server

    Radziszewski, K

    2012-01-01

    We analyze the temporal variations of the sizes and emission intensities of thirtyone flaring kernels in various parts of the H{\\alpha} line profile. We have found that the areas of all kernels decrease systematically when observed in consecutive wavelengths toward the wings of the H{\\alpha} line, but their areas and emission intensity vary in time. Our results are in agreement with the commonly accepted model of the glass-shaped lower parts of the magnetic flaring loops channelling high energy variable particle beams toward the chromospheric plasma. High time resolution spectral-imaging data used in our work were collected using the Large Coronagraph and Horizontal Telescope equipped with the Multi-channel Subtractive Double Pass Spectrograph and the Solar Eclipse Coronal Imaging System (MSDP-SECIS) at the Bia{\\l}k\\'ow Observatory of the University of Wroc{\\l}aw, Poland.

  7. Extending the $h\\alpha$ survey for the local volume galaxies

    CERN Document Server

    Karachentsev, I D; Kaisina, E I

    2015-01-01

    Images in the $H\\alpha$ emission line are presented for 35 nearby objects observed with the 6-m BTA telescope. Three of them, NGC 3377, NGC 3384, and NGC 3390, are bright E and S0 galaxies, one is an edge-on Sd galaxy UGC 7321, two are remote globular clusters associated with M 31, and the rest are dwarf galaxies of morphological types dIr, dTr, dSph, BCD, and Sm. The measured $H\\alpha$ fluxes are used to estimate the integral $(SFR)$ and specific $(sSFR)$ star formation rates for these galaxies. The values of $\\log[sSFR]$ for all these objects lie below a limit of $-0.4$(Gyr$^{-1})$. We note that the emission disk for the nearest superthin edge-on galaxy UGC 7321 has an extremely large axis ratio of $a/b = 38.$

  8. Spectropolarimetry of Broad H_alpha Lines and Geometry of the BLR

    CERN Document Server

    Cohen, M H; Cohen, Marshall H.; Martel, Andre' R.

    2001-01-01

    In a small fraction of Broad Line Radio Galaxies (BLRG) and Seyfert 1 galaxies, the polarization position angle rotates across the broad emission lines, especially at H_alpha. An understanding of this behavior can potentially yield important information on the scattering geometry in the nucleus. We show two examples of this phenomenon, 3C 445, a BLRG, and Mrk 231, a Seyfert 1, and present an equatorial scattering model that explains some of its features in a straightforward way.

  9. Lifetimes of enhanced chromospheric network features near active regions. [from solar centerline H alpha filtergrams

    Science.gov (United States)

    Prata, S. W.

    1973-01-01

    Centerline H alpha filtergrams providing nearly full-day coverage of the sun are used to study the lifetimes of enhanced network features near active regions. In the two cases studied the fraction remaining of those features present at an original epoch remains near unity for 50 hr, then drops exponentially with a 1/e decay time of 30 hr. Histories of representative enhanced network features are discussed.-

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

    OpenAIRE

    Gordon, K. D.; Perez-Gonzalez, P. G.; Misselt, K. A.; Murphy, E. J.; Bendo, G. J.; WALTER, F; Thornley, M. D.; Kennicutt, Jr., R. C.; Rieke, G. H.; Engelbracht, C. W.; Smith, J.-D. T.; Alonso-Herrero, A.; Appleton, P N; Calzetti, D.; Dale, D. A.

    2004-01-01

    We present Multiband Imaging Photometer for Spitzer (MIPS) observations of M81 at 24, 70, and 160 micron. The grand design nature of M81 is clearly seen, showing two well resolved spiral arms containing numerous bright star forming regions. The MIPS images reveal a significant amount of cold dust associated with the spiral arms. We investigate the variation of the ultraviolet (UV), H-alpha, and infrared (IR) luminosities and star formation rate (SFR) indicators across the fa...

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

    CERN Document Server

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

    2006-01-01

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

  12. Impulsive H-alpha diagnostics of electron-beam-heated solar flare model chromospheres

    Science.gov (United States)

    Canfield, Richard C.; Gayley, Kenneth G.

    1987-01-01

    Time-dependent H-alpha profiles were computed for the dynamic model atmospheres of Fisher, Canfield, and McClymont (1985) simulating the effects of an intense impulsively initiated power-law beam of electrons incident on the chromosphere. The temporal response of H-alpha arises from three separate physical mechanisms, whose relative importance varies over the line profile. The fastest variations (typically less than 0.1 s for the explosive heating discussed here) arise from energy imbalance; these are apparent on chromospheric heating and cooling time scales and have their greatest amplitude at line center. Slower variations arise from ionization imbalance and are most apparent in the blue wing. The slowest variations arise from hydrodynamic effects and are related to the formation of a chromospheric condensation; these are most apparent in the red wing. These results provide a basis for the design and analysis of observations of H-alpha, in coordination with hard X-rays or microwaves, to test mechanisms of energy transport in solar flares.

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

    CERN Document Server

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

    1997-01-01

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

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

    CERN Document Server

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

    2015-01-01

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

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

    CERN Document Server

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

    2015-01-01

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

  16. The Gaia-ESO Survey: Catalogue of H$\\alpha$ emission stars

    CERN Document Server

    Traven, Gregor; Van Eck, Sophie; Klutsch, Alexis; Bonito, Rosaria; Lanzafame, Alessandro C; Alfaro, Emilio J; Bayo, Amelia; Bragaglia, Angela; Costado, María Teresa; Damiani, Francesco; Flaccomio, Ettore; Frasca, Antonio; Hourihane, Anna; Jimenez-Esteban, Fran; Lardo, Carmela; Morbidelli, Lorenzo; Pancino, Elena; Prisinzano, Loredana; Sacco, Germano G; Worley, Clare C

    2015-01-01

    We discuss the properties of H$\\alpha$ emission stars across the sample of 22035 spectra from the Gaia-ESO Survey internal data release, observed with the GIRAFFE instrument and largely belonging to stars in young open clusters. Automated fits using two independent Gaussian profiles and a third component that accounts for the nebular emission allow us to discern distinct morphological types of H$\\alpha$ line profiles with the introduction of a simplified classification scheme. All in all we find 3765 stars with intrinsic emission and sort their spectra into eight distinct morphological categories: single--component emission, emission blend, sharp emission peaks, double emission, P-Cygni, inverted P-Cygni, self--absorption, and emission in absorption. We have more than one observation for 1430 stars in our sample, thus allowing a quantitative discussion of the degree of variability of H$\\alpha$ emission profiles, which is expected for young, active objects. We present a catalogue of stars with properties of th...

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

    CERN Document Server

    Frew, David J; Bojicic, I S

    2016-01-01

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

  18. The rank-width of Directed Graphs

    CERN Document Server

    Kante, Mamadou

    2007-01-01

    Clique-width is a complexity measure of directed as well as undirected graphs. Rank-width is an equivalent complexity measure for undirected graphs which has good algorithmic and structural properties. We compare several possible definitions of the rank-width of directed graphs. They turn out to be equivalent. We give for one of them an algebraic characterization in terms of graph operations, similar to the one that we have given for the rank-width of undirected graphs. We also adapt some recognition algorithms of Oum et al. in order to give a polynomial time approximation algorithm for the rank-width of directed graphs, and then, a polynomial time approximation algorithm for the clique-width of directed graphs.

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

    CERN Document Server

    Christlein, Daniel; Bland-Hawthorn, Joss

    2010-01-01

    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...

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

    CERN Document Server

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

    2009-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Arbutina, B.

    2009-12-01

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

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

    OpenAIRE

    Wood, Kenneth; Reynolds, Ron

    1999-01-01

    We present Monte Carlo simulations of the Diffuse H$\\alpha$ Galactic Background. Our models comprise direct and multiply scattered H$\\alpha$ radiation from the kpc scaleheight Warm Ionized Medium and midplane H II regions. The scattering is off dust that is assumed to be well mixed with the gas, with an axisymmetric density distribution taken from the literature. The results of our simulations are all-sky H$\\alpha$ images that enable us to separate out the contributions of direct and scattere...

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

    CERN Document Server

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

    2014-01-01

    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...

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

    Science.gov (United States)

    Joner, M.; Hintz, E.

    2015-12-01

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

  5. Measurement of Star-Formation Rate from H-alpha in field galaxies at z=1

    OpenAIRE

    Glazebrook, Karl; Blake, Chris; Economou, Frossie; Lilly, Simon; Colless, Matthew

    1998-01-01

    We report the results of J-band infrared spectroscopy of a sample of 13 z=1 field galaxies drawn from the Canada-France Redshift Survey, targeting galaxies whose redshifts place the rest frame H-alpha line emission from HII regions in between the bright night sky OH lines. As a result we detect emission down to a flux limit of ~10^{-16} ergs cm^{-2} s^{-1} corresponding to a luminosity limit of ~10^{41} ergs at this redshift for a H_0=50 km s^{-1} Mpc,^{-1} q_0=0.5 cosmology. From these lumin...

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

    OpenAIRE

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

    2008-01-01

    GH$\\alpha$FaS a new Fabry-Perot system, is now available at the William Herschel Telescope. It was mounted, for the first time, at the Nasmyth focus of the 4.2 meter WHT on La Palma in July 2007. Using modern technology, with a spectral resolution of the order R$\\sim$15000, and with a seeing limited spatial resolution, GH$\\alpha$FaS will provide a new look at the H$\\alpha$ -emitting gas over a 4.8 arcminutes circular field in the nearby universe. Many science programs can be done on a 4.2 met...

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

    OpenAIRE

    Hopewell, EC; Barlow, MJ; Drew, JE; Unruh, YC; Parker, QA; Pierce, MJ; Crowther, PA; Knigge, C; Phillipps, S.; Zijlstra, AA

    2005-01-01

    We report the discovery of 5 massive Wolf-Rayet (WR) stars resulting from a programme of follow-up spectroscopy of candidate emission line stars in the AAO/UKST Southern Galactic Plane H-alpha survey. The 6195-6775 angstrom spectra of the stars are presented and discussed. A WC9 class is assigned to all 5 stars through comparison of their spectra with those of known late-type WC stars, bringing the known total number of Galactic WC9 stars to 44. Whilst three of the five WC9 ...

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

    CERN Document Server

    Suyunova, E Z; Osokin, A R

    2015-01-01

    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.

  9. Approximate formulation of redistribution in the Ly-alpha, Ly-beta, H-alpha system

    Science.gov (United States)

    Cooper, J.; Ballagh, R. J.; Hubeny, I.

    1989-01-01

    Simple approximate formulas are given for the coupled redistribution of Ly-alpha, Ly-beta, and H-alpha, by using well-defined approximations to an essentially exact formulation. These formulas incorporate all the essential physics including Raman scattering, lower state radiative decay, and correlated terms representing emission during a collision which must be retained in order that the emission coefficients are properly behaved in the line wings. Approximate expressions for the appropriate line broadening parameters are collected. Finally, practical expressions for the source functions are given. These are formulated through newly introduced nonimpact redistribution functions, which are shown to be reasonably approximated by existing (ordinary and generalized) redistribution functions.

  10. An impulsive solar burst observed in H-alpha, microwaves, and hard X-rays

    Science.gov (United States)

    Gary, D. E.; Tang, F.

    1985-01-01

    H-alpha, microwave, and hard X-ray observations of an unusually short duration impulsive spike burst are presented. The observations are analyzed, and it is found that the single spike is in fact composed of two separate acceleration episodes. The differences found in the time profiles for the two components stress the role of the decay rate and lead to a simple explanation for the often observed delay of the microwave peak. The approximate numbers of electrons responsible for the two types of emission are derived and compared.

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

    OpenAIRE

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

    2001-01-01

    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...

  12. Morita Equivalence

    CERN Document Server

    Barrett, Thomas William

    2015-01-01

    Logicians and philosophers of science have proposed various formal criteria for theoretical equivalence. In this paper, we examine two such proposals: definitional equivalence and categorical equivalence. In order to show precisely how these two well-known criteria are related to one another, we investigate an intermediate criterion called Morita equivalence.

  13. Red Star Forming Galaxies and Their Environment at z=0.4 Revealed by Panoramic H-alpha Imaging

    CERN Document Server

    Koyama, Yusei; Nakata, Fumiaki; Shimasaku, Kazuhiro; Okamura, Sadanori

    2011-01-01

    We present a wide-field H-alpha imaging survey of the rich cluster CL0939+4713 (Abell 851) at z=0.41 with Suprime-Cam on the Subaru Telescope, using the narrow-band filter NB921. The survey is sensitive to active galaxies with star formation rates down to ~0.3Msun/yr throughout the 27'x27' field, and we identified 445 H-alpha emitters along the large-scale structures around the cluster. Using this sample, we find that (1) the fraction of H-alpha emitters is a strong function of environment and shows a clear decline toward the cluster central region. We also find that (2) the color of H-alpha emitters is clearly dependent on environment. The majority of the H-alpha emitters have blue colors with B-I<2, but we find H-alpha emitters with red colors as well. Such red emitters are very rare in the cluster center or its immediate surrounding regions, while they are most frequently found in groups located far away from the cluster center. These groups coincide with the environment where a sharp transition in gala...

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

    CERN Document Server

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

    2014-01-01

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

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

    CERN Document Server

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

    2011-01-01

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

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

    CERN Document Server

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

    2015-01-01

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

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

    CERN Document Server

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

    2013-01-01

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

  18. Deep H{\\alpha} Observations of NGC 253: a Very Extended and Possibly Declining Rotation Curve?

    CERN Document Server

    Hlavacek-Larrondo, J; Daigle, O; de Denus-Baillargeon, M -M; Marcelin, M; Epinat, B; Hernandez, O

    2010-01-01

    This study presents a deep H{\\alpha} kinematical analysis of the Sculptor Group galaxy NGC253. The Fabry-Perot data were taken with the 36-cm Marseille Telescope in La Silla, Chile, using an EMCCD detector. Typical emission measures of ~0.1 cm^-6 pc are reached. The observations allow the detection of the Diffuse Ionized Gas component through [N II] emission at very large radii of 11.5', 12.8' and 19.0', on the receding side of the galaxy. No H{\\alpha} emission is observed at radii larger than the neutral component (11.5'). The very extended rotation curve confirms previous results and shows signs of a significant decline, on the order of 30 per cent vmax . Using the rotation data, mass models are constructed with and without the outer [N II] data points, and similar results are found. The declining part of the rotation curve is very well modeled, and seems to be truly declining.

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

    CERN Document Server

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

    2012-01-01

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

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

    CERN Document Server

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

    2015-01-01

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

  1. Quiet Sun H\\alpha\\ Transients and Corresponding Small-Scale Transition Region and Coronal Heating

    CERN Document Server

    Henriques, V M J; Mathioudakis, M; Keenan, F P

    2016-01-01

    Rapid Blue- and Red-shifted Excursions (RBEs and RREs) are likely to be the on-disk counterparts of Type II spicules. Recently, heating signatures from RBEs/RREs have been detected in IRIS slit-jaw images dominated by transition-region lines around network patches. Additionally, signatures of Type II spicules have been observed in AIA diagnostics. The full-disk, ever-present nature of the AIA diagnostics should provide us with sufficient statistics to directly determine how important RBEs and RREs are to the heating of the transition region and corona. We find, with high statistical significance, that at least 11% of the low-coronal brightenings detected in a quiet-Sun region in 304, can be attributed to either RBEs or RREs as observed in H\\alpha, and a 6% match of 171 detected events to RBEs or RREs with very similar statistics for both types of H\\alpha\\ features. We took a statistical approach that allows for noisy detections in the coronal channels and provides us with a lower, but statistical significant,...

  2. The H alpha Galaxy Survey. IV. Star formation in the local Universe

    CERN Document Server

    James, P A; Shane, N S; Baldry, I K; De Jong, R S

    2008-01-01

    We present an analysis of the star formation properties of field galaxies within the local volume out to a recession velocity limit of 3000 km/s. A parent sample of 863 star-forming galaxies is used to calculate a B-band luminosity function. This is then populated with star formation information from a subsample of 327 galaxies, for which we have H alpha imaging, firstly by calibrating a relationship between galaxy B-band luminosity and star formation rate, and secondly by a Monte Carlo simulation of a representative sample of galaxies, in which star formation information is randomly sampled from the observed subset. The total star formation rate density of the local Universe is found to be between 0.016 and 0.023 MSun/yr/cubic Mpc, with the uncertainties being dominated by the internal extinction correction used in converting measured H alpha fluxes to star formation rates. If our internally derived B-band luminosity function is replaced by one from the Sloan Digital Sky Survey blue sequence, the star format...

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

    CERN Document Server

    Frew, David J; Parker, Quentin A

    2016-01-01

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

  4. Comportamiento de la cromósfera solar en la línea H-alpha durante el ciclo 23

    Science.gov (United States)

    Davoli, D.; Aquilano, R.; Missio, H.

    Using the instrumental of the Observatorio Astronómico Municipal de Rosario (OAMR), we analyze the solar chromospheric activity during an approximate period of 11 years. The instrument is a Carl Zeiss refractor telescope of 150 mm aperture and 2250 mm of focal distance with monochromatic filter in the H-alpha line. We take as proxy for the solar activity the area covered by chromospheric plages. Simultaneously, we determine the relative wolf number from observations of the solar photosphere. We describe our technique and the results obtained. We observe 2 maxima of solar activity in the years 2000 and 2001 respectively, and a later decrease of this activity with low average values starting around 2006 that corresponds to the end of cycle 23. FULL TEXT IN SPANISH

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

    CERN Document Server

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

    2005-01-01

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

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

    Science.gov (United States)

    Kucera, Therese A.; Landi, E.

    2006-01-01

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

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

    CERN Document Server

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

    2014-01-01

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

  8. An atlas of H-alpha-emitting regions in M33: A systematic search for SS433 star candidates

    Science.gov (United States)

    Calzetti, Daniela; Kinney, Anne L.; Ford, Holland; Doggett, Jesse; Long, Knox S.

    1995-01-01

    We report finding charts and accurate positions for 432 compact H-alpha emitting regions in the Local Group galaxy M 33 (NGC 598), in an effort to isolate candidates for an SS433-like stellar system. The objects were extracted from narrow band images, centered in the rest-frame H-alpha (lambda 6563 A) and in the red continuum at 6100 A. The atlas is complete down to V approximately equal to 20 and includes 279 compact HII regions and 153 line emitting point-like sources. The point-like sources undoubtedly include a variety of objects: very small HII regions, early type stars with intense stellar winds, and Wolf-Rayet stars, but should also contain objects with the characteristics of SS433. This extensive survey of compact H-alpha regions in M 33 is a first step towards the identification of peculiar stellar systems like SS433 in external galaxies.

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

    CERN Document Server

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

    2015-01-01

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

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

    CERN Document Server

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

    2013-01-01

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

  11. The Second Data Release of the INT Photometric H-Alpha Survey of the Northern Galactic Plane (IPHAS DR2)

    OpenAIRE

    Barentsen, Geert; H. J. Farnhill; Drew, J E.; González-Solares, E. A.; Greimel, R.; Irwin, M. J.; B. Miszalski; Ruhland, C.; Groot, P.; Mampaso, ; A.; S. E. Sale; Henden, A.A.; Aungwerojwit, A.; Barlow, M. J; Carter, P. J.

    2014-01-01

    The INT/WFC Photometric H-Alpha Survey of the Northern Galactic Plane (IPHAS) is a 1800 square degrees imaging survey covering Galactic latitudes |b| < 5 deg and longitudes l = 30 to 215 deg in the r, i and H-alpha filters using the Wide Field Camera (WFC) on the 2.5-metre Isaac Newton Telescope (INT) in La Palma. We present the first quality-controlled and globally-calibrated source catalogue derived from the survey, providing single-epoch photometry for 219 million unique ...

  12. Nature of H-alpha selected galaxies at z>2. I. Main sequence and dusty star-forming galaxies

    CERN Document Server

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

    2013-01-01

    We present the results from our narrow-band imaging surveys of HAEs at z=2.2 and z=2.5 in the Subaru/XMM-Newton Deep survey Field with near-infrared camera MOIRCS on Subaru Telescope. We have constructed a clean sample of 63 star-forming galaxies at z=2.2 and 46 at z=2.5. For 12 (or ~92%) out of 13 H\\alpha emitters (HAEs) at z=2.2, their H\\alpha emission lines have been successfully detected by the spectroscopy. While about 42% of the red, massive HAEs with M_*>10^{10.8} M_\\odot contain AGNs, most of the blue, less massive ones are likely to be star-forming galaxies. This suggests that the AGN may play an important role in galaxy evolution at the late stage of truncation. For the HAEs excluding possible AGNs, we estimate the gas-phase metallicities on the basis of [N~{\\sc ii}]/H\\alpha ratios, and find that the metallicities of the H\\alpha selected galaxies at z=2.2 are lower than those of local star-forming galaxies at fixed stellar mass, as shown by previous studies. Moreover, we present and discuss the so-c...

  13. Detection of H-alpha emission from z>3.5 submillimetre luminous galaxies with AKARI-FUHYU spectroscopy

    CERN Document Server

    Sedgwick, Chris; Pearson, Chris; Smail, Ian; Im, Myungshin; Oyabu, Shinki; Takagi, Toshinobu; Matsuhara, Hideo; Wada, Takehiko; Lee, Hyung Mok; Jeong, Woong-Seob; White, Glenn J

    2013-01-01

    We present tentative H-alpha emission line detections of four submillimetre-detected galaxies at z>3.5: the radio galaxies 8C1909+722 and 4C60.07 at signal-to-noise ratios (SNRs) of 3.1 and 2.5, and two submillimetre-selected galaxies (SMGs) near the first of these at SNRs of 10.0 and 2.4, made with the AKARI Space Telescope as part of the FUHYU mission program. These are the highest-redshift H-alpha detections in such galaxies, made possible by AKARI's unique near-infrared spectroscopic capability. The two radio galaxies had known redshifts and surrounding structure, and we have detected broad H-alpha components indicating the presence of dust-shrouded quasars. We conclude that powerful AGNs at z>3.5 occur in peaks of the star-formation density fields, supporting a close connection between stellar mass build-up and black hole mass assembly at this redshift. We also show that 4C60.07 is a binary AGN. The H-alpha detections of the two SMGs are the first redshift determinations for these sources, confirming the...

  14. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-02-15

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

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

    CERN Document Server

    Kaisin, S S

    2013-01-01

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

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

    CERN Document Server

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

    2014-01-01

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

  18. Comparison of H-alpha synoptic charts with the large-scale solar magnetic field as observed at Stanford

    Science.gov (United States)

    Duvall, T. L., Jr.; Wilcox, J. M.; Svalgaard, L.; Scherrer, P. H.; Mcintosh, P. S.

    1977-01-01

    Two methods of observing the neutral line of the large-scale photospheric magnetic field are compared: neutral line positions inferred from H-alpha photographs (McIntosh and Nolte, 1975) and observations of the photospheric magnetic field made with low spatial resolution (three minutes) and high sensitivity using the Stanford magnetograph. The comparison is found to be very favorable.

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

    CERN Document Server

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    C. Saffe

    2011-01-01

    Full Text Available Implementamos un programa en Fortran que determina parámetros fundamentales de estrellas de tipo solar, a partir de anchos equivalentes del Fe. La solución debe verificar tres condiciones en el método estándar: equilibrio de ionización, equilibrio de excitación e independencia entre abundancias y anchos equivalentes. Calculamos modelos de atmósfera de Kurucz con opacidades NEWODF. Detalles como el parámetro de longitud de mezcla, el sobre impulso convectivo, etc. se calculan con un programa independiente. FUNDPAR calcula las incertezas por dos métodos: el criterio de Gonzalez & Vanture (1998 y utilizando la función X² . Los resultados derivados con FUNDPAR están de acuerdo con determinaciones previas en la literatura. En particular obtuvimos parámetros fundamentales de 58 estrellas con exoplanetas. El programa está disponible en la red1.

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

    CERN Document Server

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

    2014-01-01

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

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

    CERN Document Server

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

    2005-01-01

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

  3. Improved measurement of (3)J(H(alpha)(i),N(i+1)) coupling constants in H(2)O dissolved proteins.

    Science.gov (United States)

    Löhr, F; Schmidt, J M; Maurer, S; Rüterjans, H

    2001-11-01

    A modification to the recently proposed alpha/beta-HN(CO)CA-J TROSY pulse sequence (P. Permi et al., J. Magn. Reson. 146, 255-259 (2000)) makes it possible to determine (3)J(H(alpha)(i), N(i+1)) coupling constants from a single E.COSY-type cross-peak pattern rather than from two (1)H(alpha) spin-state-edited subspectra. Advantages are increased (15)N resolution, critical to extracting accurate (1)H(alpha)-(15)N coupling constants, and minimized differential relaxation due to nested (13)C(alpha) and (15)N evolution periods. Application of the improved pulse sequence to Desulfovibrio vulgaris flavodoxin results in (3)J(H(alpha)(i), N(i+1)) values being systematically larger than those obtained with the original scheme. Parametrization of the coupling dependence on the protein backbone torsion angle psi yields the Karplus relation (3)J(H(alpha)(i), N(i+1))=-1.00 cos(2)(psi-120 degrees )+0.65 cos(psi-120 degrees )-0.15 Hz, with a residual root-mean-square difference of 0.13 Hz between measured and back-calculated coupling constants. The curve compares with data derived from ubiquitin (A. C. Wang and A. Bax, J. Am. Chem. Soc. 117, 1810-1813 (1995)), although spanning a slightly larger range of J values in flavodoxin. The orientation of the Ala39/Ser40 peptide link, forming a type-II beta-turn in flavodoxin, is twisted against X-ray-derived torsions by approximately 10 degrees in the NMR structure as evident from the analysis of straight phi- and psi-related (3)J coupling constants. The remaining deviation of some experimental values from the prediction is likely to be due to strong hydrogen bonding, substituent effects, or the additional dependence on the adjacent torsions straight phi. PMID:11700083

  4. Relative Strengths of Raman Scattered He II 6545 and H alpha Wings In the Symbiotic Star V1016 Cyg and the Young Planetary Nebulae IC 5117

    Science.gov (United States)

    Lee, H.-W.; Kang, Suna

    2006-08-01

    Many symbiotic stars and some young planetary nebulae are known to exhibit very prominent and broad wings around H alpha emission. Lee (2000) proposed that these H alpha wings are formed from Raman scattering by atomic hydrogen of far UV radiation around Ly beta. However, broad wings may also arise from other mechanisms including fast gas flows around the hot star and Thomson scattering. Furthermore, it is unclear whether continuum around Ly beta or Ly beta line photons themselves are responsible for the broad H alpha wings in the proposal of Lee (2000). In order to confirm the Raman scattering origin of H alpha wings, we present our high resolution spectrum around H alpha of the symbiotic star V1016 Cyg and the young planetary nebula IC 5117 obtained with the Bohyunsan Optical Echelle Spectrograph installed on the 1.8m telescope. The two objects show relatively strong Raman scattered He II 6545 features but H alpha wings are significantly weak in IC 5117 compared with those in V1016 Cyg. In the spectra, we note that the H alpha and He II emission lines in IC 5117 are much narrower than the counterparts in V1016 Cyg. Applying Gaussian fits to these emission lines and inferring the far UV radiation compatible with the recombination theory, we perform Monte Carlo simulations of Raman scattered He II 6545 and H alpha wings in an assumed neutral region with H I column density of 10^22 cm^-2. Our numerical results show relatively weak H alpha wings compared with He II 6545 in IC 5117 and quite strong H alpha wings in V 1016 Cyg, which is consistent with our observational spectra. This result strongly indicates that the broad H alpha wings are originated from the Ly beta line photons not continuum photons around Ly beta.

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

    CERN Document Server

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

    2016-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Suarez, C.

    1984-07-01

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

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

    Science.gov (United States)

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

    1989-01-01

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

  8. H-alpha Imaging of X-ray Sources in Selected Globular Clusters with the SOAR Telescope

    OpenAIRE

    Pietrukowicz, Pawel

    2009-01-01

    We present results of a search for objects with H-alpha excess, such as cataclysmic variables (CVs) and chromospherically active binaries (ABs), as counterparts to X-ray sources detected with Chandra satellite observatory in six Galactic globular clusters (GCs): M4, M28, M30, M71, M80, NGC 6752. Binary systems play a critical role in the evolution of GCs, serving as an internal energy source countering the tendency of GC cores to collapse. Theoretical studies predict dozens ...

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

    CERN Document Server

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

    2014-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-09-01

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

  11. Dust attenuation in z $\\sim$ 1 galaxies from Herschel and 3D-HST H$\\alpha$ measurements

    CERN Document Server

    Puglisi, A; Franceschini, A; Talia, M; Cimatti, A; Baronchelli, I; Daddi, E; Renzini, A; Schawinski, K; Mancini, C; Silverman, J; Gruppioni, C; Lutz, D; Berta, S; Oliver, S J

    2015-01-01

    We combined the spectroscopic information from the 3D-HST survey with the PEP/Herschel data to characterize the H\\alpha dust attenuation properties of a sample of 79 normal star-forming galaxies at $0.7\\leq z\\leq1.5$ in the GOODS-S field. The sample was selected in the far-IR, at \\lambda=100 and/or 160 \\mu m, and only includes galaxies with a secure H\\alpha detection (S/N>3). From the low resolution 3D-HST spectra we measured z and F(H\\alpha) for the whole sample, rescaling the observed flux by a constant factor of 1.2 to remove the contamination by [NII]. The stellar masses, infrared and UV luminosities were derived from the SEDs by fitting multi-band data from GALEX near-UV to SPIRE500 \\mu m. We derived the continuum extinction Estar(B-V) from both the IRX ratio and the UV-slope, and found an excellent agreement among them. Galaxies in the sample have 2.6x10^9$\\leq$M*$\\leq$3.5x10^11 Msun, intense infrared luminosity (L_IR>1.2x10^10 Lsun), high level of dust obscuration (0.1$\\leq$Estar(B-V)$\\leq$1.1) and str...

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

    CERN Document Server

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

    2013-01-01

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

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

    CERN Document Server

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

    2012-01-01

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

  14. 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

  15. Gyrokinetic equivalence

    International Nuclear Information System (INIS)

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

  16. Gyrokinetic equivalence

    Energy Technology Data Exchange (ETDEWEB)

    Parra, Felix I; Catto, Peter J [Plasma Science and Fusion Center, MIT, Cambridge, MA 02139 (United States)], E-mail: fparra@mit.edu, E-mail: catto@psfc.mit.edu

    2009-06-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-12-01

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

  18. Optical observations of the nearby galaxy IC342 with narrow band [SII] and H$\\alpha$ filters. II - Detection of 16 Optically-Identified Supernova Remnant Candidates

    CERN Document Server

    Vucetic, M M; Pavlovic, M Z; Pannuti, T G; Petrov, N; Goker, U D; Ercan, E N

    2015-01-01

    We present the detection of 16 optical supernova remnant (SNR) candidates in the nearby spiral galaxy IC342. The candidates were detected by applying [SII]/H$\\alpha$ ratio criterion on observations made with the 2 m RCC telescope at Rozhen National Astronomical Observatory in Bulgaria. In this paper, we report the coordinates, diameters, H$\\alpha$ and [SII] fluxes for 16 SNRs detected in two fields of view in the IC342 galaxy. Also, we estimate that the contamination of total H$\\alpha$ flux from SNRs in the observed portion of IC342 is 1.4%. This would represent the fractional error when the star formation rate (SFR) for this galaxy is derived from the total galaxy's H$\\alpha$ emission.

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

    Science.gov (United States)

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

    2009-05-01

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

  20. GHASP : an H alpha kinematic survey of spiral and irregular galaxies. V. Dark matter distribution in 36 nearby spiral galaxies

    CERN Document Server

    Spano, M; Amram, P; Carignan, C; Epinat, B; Hernández, O

    2007-01-01

    The results obtained from a study of the mass distribution of 36 spiral galaxies are presented. The galaxies were observed using Fabry-Perot interferometry as part of the GHASP survey. The main aim of obtaining high resolution H alpha 2D velocity fields is to define more accurately the rising part of the rotation curves which should allow to better constrain the parameters of the mass distribution. The H alpha velocities were combined with low resolution HI data from the literature, when available. Combining the kinematical data with photometric data, mass models were derived from these rotation curves using two different functional forms for the halo: an isothermal sphere and an NFW profile. For the galaxies already modeled by other authors, the results tend to agree. Our results point at the existence of a constant density core in the center of the dark matter halos rather than a cuspy core, whatever the type of the galaxy from Sab to Im. This extends to all types the result already obtained by other author...

  1. H{\\alpha} and UV luminosities and star formation rates in a large sample of luminous compact galaxies

    CERN Document Server

    Parnovsky, S L; Izotov, Y I

    2012-01-01

    We present the results of a statistical study of the star formation rates (SFR) derived from the Galaxy Evolution Explorer (GALEX) observations in the ultraviolet continuum and in the H\\alpha emission line for a sample of about 800 luminous compact galaxies (LCGs). Galaxies in this sample have a compact structure and include one or several regions of active star formation. Global galaxy characteristics (metallicity, luminosity, stellar mass) are intermediate between ones of the nearby blue compact dwarf (BCD) galaxies and Lyman-break galaxies (LBGs) at high redshifts z > 2 - 3. SFRs were corrected for interstellar extinction which was derived from the optical Sloan Digital Sky Survey (SDSS) spectra. We find that SFRs derived from the galaxy luminosities in the far ultraviolet (FUV) and near ultraviolet (NUV) ranges vary in a wide range from 0.18 M_Sun/yr to 113 M_Sun/yr with median values of 3.8 M_Sun/yr and 5.2 M_Sun/yr, respectively. Simple regression relations are found for luminosities L(H\\alpha) and L(UV...

  2. On the relationship between soft X-rays and H-alpha-emitting structures during a solar flare

    Science.gov (United States)

    Zirin, H.; Feldman, U.; Doschek, G. A.; Kane, S.

    1981-01-01

    Based on data obtained during a solar flare on March 31, 1979, soft X-ray (SXR) and hard X-ray (HXR) bursts are analyzed and compared with other available data in order to identify structures in H-alpha that may correspond to the SXR-emitting site. Measurements taken with the X-ray telescope and the XUV spectroheliograph flown on Skylab, have shown that the SXR emission from many flares comes from rather small structures of about 10-20 arcsec across. These structures appear to be loops that cross the magnetic neutral line. Understanding of the morphology of SXR was based on data of the solar flare of June 15, 1973, observed from Skylab, and the work of Moore et al., (1980). Dense, highly emissive coronal structures, not suggested to be the X-ray source, were forming, lost energy rapidly by emission and conduction, and finally formed the loops. It is concluded that bright H-alpha loops form rapidly as the SXR emission rises, and the overall decay (cooling rate) of SXR emission is much slower than the formation time of individual loops.

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

    CERN Document Server

    Sadykov, Viacheslav M

    2014-01-01

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

  4. A search for Ejecta Nebulae around Wolf-Rayet Stars using the SHS H$\\alpha$ survey

    CERN Document Server

    Stock, D J

    2010-01-01

    Recent large scale Galactic Plane H$\\alpha$ surveys allow a re-examination of the environs of Wolf-Rayet (WR) stars for the presence of a circumstellar nebula. Using the morphologies of WR nebulae known to be composed of stellar ejecta as a guide, we constructed ejecta nebula criteria similar to those of Chu (1991) and searched for likely WR ejecta nebula in the SHS H$\\alpha$ survey. A new Wolf-Rayet ejecta nebula around WR 8 is found and its morphology discussed. The fraction of WR stars with ejecta type nebulae is roughly consistent between the MilkyWay (MW) and LMC at around 5-6%, with the MW sample dominated by nitrogen rich WR central stars (WN type) and the LMC stars having a higher proportion of carbon rich WR central stars (WC type). We compare our results with those of previous surveys, including those of Marston (1997) and Miller & Chu (1993), and find broad consistency. We investigate several trends in the sample: most of the clear examples of ejecta nebulae have WNh central stars; and very few...

  5. Fluxes in H\\alpha and Ca II H and K for a sample of Southern stars

    CERN Document Server

    Cincunegui, C; Mauas, P J D; Cincunegui, Carolina; D\\'iaz, Rodrigo F.; Mauas, Pablo J. D.

    2007-01-01

    The main chromospheric activity indicator is the S index, which is esentially the ratio of the flux in the core of the Ca II H and K lines to the continuum nearby, and is well studied basically for stars from F to K. Another usual chromospheric proxy is the H\\alpha line, which is beleived to be tightly correlated with the Ca II index. In this work we characterize both chromospheric activity indicators, one associated with the H and K Ca II lines and the other with H\\alpha, for the whole range of late type stars, from F to M. We present periodical medium-resolution echelle observations covering the complete visual range, which were taken at the CASLEO Argentinean Observatory. These observations are distributed along 7 years. We use a total of 917 flux-calibrated spectra for 109 stars which range from F6 to M5. We statistically study these two indicators for stars of different activity levels and spectral types. We directly derive the conversion factor which translate the known S index to flux in the Ca II core...

  6. Alpha widths from nuclear models

    International Nuclear Information System (INIS)

    Methods to calculate alpha widths from nuclear model wavefunctions are reviewed and the underlying assumptions discussed. Comparison of experimental and calculated reduced widths is made. Some new results on absolute values of alpha transition rates are reported

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-02-20

    Identifying the electromagnetic counterparts of gravitational wave (GW) sources detected by upcoming networks of advanced ground-based interferometers will be challenging, due in part to the large number of unrelated astrophysical transients within the {approx}10-100 deg{sup 2} sky localizations. A potential way to greatly reduce the number of such false positives is to limit detailed follow-up to only those candidates near galaxies within the GW sensitivity range of {approx}200 Mpc for binary neutron star mergers. Such a strategy is currently hindered by the fact that galaxy catalogs are grossly incomplete within this volume. Here, we compare two methods for completing the local galaxy catalog: (1) a narrowband H{alpha} imaging survey and (2) an H I emission line radio survey. Using H{alpha} fluxes, stellar masses (M {sub *}), and star formation rates (SFRs) from galaxies in the Sloan Digital Sky Survey (SDSS), combined with H I data from the GALEX Arecibo SDSS Survey and the Herschel Reference Survey, we estimate that an H{alpha} survey with a luminosity sensitivity of L {sub H{alpha}} = 10{sup 40} erg s{sup -1} at 200 Mpc could achieve a completeness of f {sup H{alpha}} {sub SFR} Almost-Equal-To 75% with respect to total SFR, but only f{sub M* Star-Operator }{sup H{alpha}} approx. 33% with respect to M {sub *} (due to lack of sensitivity to early-type galaxies). These numbers are significantly lower than those achieved by an idealized spectroscopic survey due to the loss of H{alpha} flux resulting from resolving out nearby galaxies and the inability to correct for the underlying stellar continuum. An H I survey with sensitivity similar to the proposed WALLABY survey on ASKAP could achieve f{sub SFR}{sup H{sub I}} Almost-Equal-To 80% and f{sub M Star-Operator }{sup H{sub I}} Almost-Equal-To 50%, somewhat higher than that of the H{alpha} survey. Finally, both H{alpha} and H I surveys should achieve {approx}> 50% completeness with respect to the host galaxies of short-duration gamma-ray bursts, which may trace the population of binary neutron star mergers.

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

    CERN Document Server

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

    2011-01-01

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

  9. Comparison of 30 THz impulsive burst time development to microwaves, H-alpha, EUV, and GOES soft X-rays

    CERN Document Server

    Miteva, R; Cabezas, D P; Cassiano, M M; Fernandes, L O T; Freeland, S L; Karlicky, M; Kerdraon, A; Kudaka, A S; Luoni, M L; Marcon, R; Raulin, J -P; Trottet, G; White, S M

    2015-01-01

    The recent discovery of impulsive solar burst emission in the 30 THz band is raising new interpretation challenges. One event associated with a GOES M2 class flare has been observed simultaneously in microwaves, H-alpha, EUV, and soft X-ray bands. Although these new observations confirm some features found in the two prior known events, they exhibit time profile structure discrepancies between 30 THz, microwaves, and hard X-rays (as inferred from the Neupert effect). These results suggest a more complex relationship between 30 THz emission and radiation produced at other wavelength ranges. The multiple frequency emissions in the impulsive phase are likely to be produced at a common flaring site lower in the chromosphere. The 30 THz burst emission may be either part of a nonthermal radiation mechanism or due to the rapid thermal response to a beam of high-energy particles bombarding the dense solar atmosphere.

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

    CERN Document Server

    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

    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.

  11. Classical T Tauri stars with VPHAS$+$: I: H$\\alpha$ and $u$-band accretion rates in the Lagoon Nebula M8

    CERN Document Server

    Kalari, V M; Drew, J E; Barentsen, G; Drake, J J; Eislöffel, J; Martín, E L; Parker, Q A; Unruh, Y C; Walton, N A; Wright, N J

    2015-01-01

    We estimate the accretion rates of 235 Classical T Tauri star (CTTS) candidates in the Lagoon Nebula using $ugri$H$\\alpha$ photometry from the VPHAS+ survey. Our sample consists of stars displaying H$\\alpha$-excess, the intensity of which is used to derive accretion rates. For a subset of 87 stars, the intensity of the $u$-band excess is also used to estimate accretion rates. We find the mean variation in accretion rates measured using H$\\alpha$ and $u$-band intensities to be $\\sim$ 0.17 dex, agreeing with previous estimates (0.04-0.4 dex) but for a much larger sample. The spatial distribution of CTTS align with the location of protostars and molecular gas suggesting that they retain an imprint of the natal gas fragmentation process. Strong accretors are concentrated spatially, while weak accretors are more distributed. Our results do not support the sequential star forming processes suggested in the literature.

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

    CERN Document Server

    Zhang, XueGuang

    2015-01-01

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

  13. 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

  14. Probabilistic Analysis of Crack Width

    Directory of Open Access Journals (Sweden)

    J. Marková

    2000-01-01

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

  15. A deterministic width function model

    Directory of Open Access Journals (Sweden)

    C. E. Puente

    2003-01-01

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

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

    CERN Document Server

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

    2015-01-01

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

  17. ZFIRE: Galaxy Cluster Kinematics, H$\\alpha$ Star Formation Rates, and Gas-Phase Metallicities of XMM-LSS J02182-05102 at z=1.6233

    CERN Document Server

    Tran, Kim-Vy H; Yuan, Tiantian; Kacprzak, Glenn G; Glazebrook, Karl; Kewley, Lisa J; Momcheva, Ivelina; Papovich, Casey J; Quadri, Ryan; Rudnick, Greg; Saintonge, Amélie; Spitler, Lee R; Straatman, Caroline; Tomczak, Adam

    2015-01-01

    We spectroscopically survey the galaxy cluster XMM-LSS J02182-05102 (hereafter IRC 0218) using LRIS (optical) and MOSFIRE (near-infrared) on Keck I as part of the ZFIRE survey. IRC 0218 has a narrow redshift range of $1.612H$\\alpha$ star formation rates (SFR), gas phase metallicities from [NII]/H$\\alpha$, and stellar masses. We measure an integrated H$\\alpha$ SFR of $\\sim325{\\rm M}_{\\odot}$ yr$^{-1}$ (26 members; R$_{\\rm proj}<2$ Mpc) and show that the elevated star formation in the cluster core (R$_{\\rm proj}<0.25$ Mpc) is driven by the concentration of star-forming members, but the average SFR per H$\\alpha$-detected galaxy is half th...

  18. Structure of the inner R Aquarii nebula in the light of H-alpha and forbidden N II 6584 A emission

    International Nuclear Information System (INIS)

    The structure of the inner R Aqr nebulosity in the light of H-alpha and forbidden N II 6584 A emission was investigated using data obtained on November 28, 1986, by the Space Telescope Science Institute coronograph on the ESO 2.2-m telescope. The results are presented in the form of photometrically accurate contour maps of the region. In addition to the previously established features of the inner nebulosity, a bright new feature was detected at 8.4 arcsec from the nucleus at 20 deg p.a., emitting a total flux of 1.7 x 10 to the -12th and 2.2 x 10 to the -12th ergs/sq cm per sec in the H-alpha and N II lines, respectively, which appeared to be associated with the extended feature at the end of the jet. The N II/H-alpha ratio 1.3 of the new feature is strongly suggestive of shock-wave heating or photoionization by a power-law continuum as the principal excitation mechanism. In addition to the 20-deg p.a. feature, a weaker feature, visible only in H-alpha was detected at 3.8 arcsec, 306 deg p.a. 25 references

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

    CERN Document Server

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

    2013-01-01

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

  20. 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

    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

    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...

  1. Synthesis of H-alpha absorption in old stellar systems: Formation of the cluster red sequence by "Downsizing"

    CERN Document Server

    Smith, R J

    2005-01-01

    We compute population synthesis models for the variation of H-alpha absorption indices (HaA and HaF), as a function of age and metallicity in old stellar systems. The models are based on the STELIB spectral library, and defined at resolution of 3 Angstrom FWHM. The indices are found to be highly sensitive to age variation, with only moderate response to metallicity. For galaxies uncontaminated by nebular emission, our HaA index is more powerful in breaking the age/metallicity degeneracy than H-beta or H-gamma_F. Using a sample of red cluster galaxies carefully selected to exclude objects with emission, we find a steep decline of HaA with velocity dispersion (slope -0.75 +/- 0.07 Angstrom/dex). The slope can be translated to constraints on age and metallicity scaling relations, incorporating measurement and model errors. If the HaA-sigma slope is due only to age, we obtain Age proportional to sigma^{0.95 +/- 0.12}. Because HaA depends quite weakly on [Fe/H], a metallicity interpretation would require Fe/H prop...

  2. HST/ACS H-alpha Imaging of the Carina Nebula: Outflow Activity Traced by Irradiated Herbig-Haro Jets

    CERN Document Server

    Smith, Nathan; Walborn, Nolan R

    2010-01-01

    We report the discovery of new Herbig-Haro (HH) jets in the Carina Nebula, and we discuss the protostellar outflow activity of a young OB association. These are the first results of an HST/ACS H-alpha imaging survey of Carina. Adding to the one previously known example (HH666), we detect 21 new HH jets, plus 17 new candidate jets, ranging in length from 0.005 to 3 pc. We derive jet mass-loss rates ranging from 8e-9 to 1e-6 Msun/yr, but a comparison to the distribution of jet mass-loss rates in Orion suggests that we may be missing a large fraction of the jets below 1e-8 Msun/yr. A key qualitative result is that even some of the smallest dark globules with sizes of 0.01pc are active sites of ongoing star formation because we see HH jets emerging from them, and that these offer potential analogs to the cradle of our Solar System because of their proximity to dozens of imminent supernovae that will enrich them with radioactive nuclides like 60Fe. HST images reveal proplyd structures in the core of the Tr14 clust...

  3. An H $\\alpha$ Survey of 8 Abell Clusters the Dependence of Tidally-Induced Star Formation on Cluster Density

    CERN Document Server

    Moss, C

    2000-01-01

    We have undertaken a survey of H alpha emission in a substantially complete sample of CGCG galaxies of types Sa and later within 1.5 Abell radii of the centres of 8 low-redshift Abell clusters. Some 320 galaxies were surveyed, of which 116 were detected in emission (390f spirals, 75563641f peculiars). Detected emission was classified as `compact' or `diffuse'. From an analysis of the full survey sample, we reconfirm our previous identification of compact and diffuse emission with circumnuclear starburst and disk emission respectively. The circumnuclear emission is associated either with the presence of a bar, or with a disturbed galaxy morphology indicative of on-going tidal interactions. The frequency of such tidally-induced (circumnuclear) starburst emission in spirals increases from regions of lower to higher local galaxy surface density, and from clusters with lower to higher central galaxy space density. We conclude that tidal interactions are likely to be the main mechanism for the transformation of spi...

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

    CERN Document Server

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

    2012-01-01

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

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

    CERN Document Server

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

    2011-01-01

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

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

    CERN Document Server

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

    2014-01-01

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

  7. STAR FORMATION PROPERTIES IN THE LOCAL VOLUME GALAXIES VIA H{alpha} AND FAR-ULTRAVIOLET FLUXES

    Energy Technology Data Exchange (ETDEWEB)

    Karachentsev, Igor D.; Kaisina, Elena I., E-mail: ikar@sao.ru, E-mail: kei@sao.ru [Special Astrophysical Observatory, Russian Academy of Sciences, Nizhnij Arkhyz, Karachai-Cherkessian Republic 369167 (Russian Federation)

    2013-09-15

    A distance-limited sample of 869 objects from the Updated Nearby Galaxy Catalog is used to characterize the star formation status of the Local Volume population. We present a compiled list of 1217 star formation rate (SFR) estimates for 802 galaxies within 11 Mpc, derived from the H{alpha} imaging surveys and the GALEX far-ultraviolet survey. We briefly discuss some basic scaling relations between SFR and luminosity, morphology, H I mass, surface brightness, and the environment of the galaxies. About 3/4 of our sample consist of dwarf galaxies, for which we offer a more refined classification. We note that the specific SFR of nearly all luminous and dwarf galaxies does not exceed the maximum value: log (SFR/L{sub K} ) = -9.4 [yr{sup -1}]. Most spiral and blue dwarf galaxies have enough time to generate their stellar mass during the cosmological time, T{sub 0}, with the observed SFRs. They dispose of a sufficient amount of gas to support their present SFRs over the next T{sub 0} term. We note that only a small fraction of BCD, Im, and Ir galaxies (about 1/20) proceed in a mode of vigorous starburst activity. In general, the star formation history of spiral and blue dwarf galaxies is mainly driven by their internal processes. The present SFRs of E, S0, and dSph galaxies typically have 1/30-1/300 of their former activity.

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

    International Nuclear Information System (INIS)

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

  9. Width difference of ? vector mesons

    International Nuclear Information System (INIS)

    We compute the difference in decay widths between charged and neutral ?(770) vector mesons. The isospin breaking arising from mass differences of neutral and charged ? and ? mesons, radiative corrections to ????, and the ????? decays are taken into account. It is found that the width difference ??? is very sensitive to the isospin breaking in the ? meson mass, ?m?. This result can be useful to test the correlations observed between the values of these parameters extracted from experimental data

  10. Politico-economic equivalence

    DEFF Research Database (Denmark)

    Gonzalez Eiras, Martin; Niepelt, Dirk

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-05-01

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

  12. Facilitation of the equivalence--equivalence responding.

    Science.gov (United States)

    Pérez Fernández, Vicente Jesús; García García, Andrés; Gómez Bujedo, Jesús

    2011-08-01

    Equivalence-Equivalence responding, based on equivalence class formation, is a key concept of the functional-analytic model of analogical reasoning held by RFT theorists. Relational stimulus control is supposed to play an important role in this arbitrary relational response. Previous research showed that mere training of the prerequisites for equivalence class formation is not always enough for the derivation of equivalence-equivalence responding, even in adults. In the first experiment, with 12 adult participants, we designed a matching-to-sample training and testing procedure that, although it provided all necessary conditions, did not lead to Equivalence-Equivalence responding in most participants, so that the efficacy of a facilitation procedure could be assessed. In Experiment 2, with 32 valid participants, a matching-to-sample procedure based on non-arbitrary relations was introduced to assess its efficacy in enhancing stimulus control by the relational properties of sample and comparisons. Results showed a moderate effect: 40.6% of the participants passed the test after being exposed to a non-arbitrary relational matching task (but none without it). This research underlines the importance of non-arbitrary relational responses in the derivation of more complex repertoires. PMID:21774893

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

    CERN Document Server

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

    2015-01-01

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

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

    Science.gov (United States)

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

    1990-01-01

    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.

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

    International Nuclear Information System (INIS)

    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. 63 refs

  16. Width of radiative decay ?(1520)???

    International Nuclear Information System (INIS)

    The radiative decay ?(1520)??? was measured in the study of exclusive reaction p+N??(1520)K++N with the SPHINX spectrometer. The values of branching ratio and partial width of this decay were determined: BR[?(1520)???]=(1.02±0.21)x10-2 and ?[?(1520)???]=159±35 keV (statistical uncertainty; systematic uncertainty is below 15 %)

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

    OpenAIRE

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

    2011-01-01

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

  18. Politico-economic equivalence

    DEFF Research Database (Denmark)

    Gonzalez Eiras, Martin; Niepelt, Dirk

    2015-01-01

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

  19. Politico-economic equivalence

    DEFF Research Database (Denmark)

    Gonzalez Eiras, Martin; Niepelt, Dirk

    2015-01-01

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

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

    CERN Document Server

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

    2000-01-01

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

  1. Equivalence principles and electromagnetism

    Science.gov (United States)

    Ni, W.-T.

    1977-01-01

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

  2. On the maximal diphoton width

    OpenAIRE

    Salvio, Alberto(Departamento de Física Teórica, Universidad Autónoma de Madrid and Instituto de Física Teórica IFT-UAM/CSIC, Madrid, Spain); Staub, Florian; STRUMIA, Alessandro; Urbano, Alfredo(SISSA, via Bonomea 265, Trieste, I-34136 ITALY)

    2016-01-01

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

  3. ?(1520) ? ?? Radiative-Decay Width

    International Nuclear Information System (INIS)

    The radiative decay ?(1520) ? ?? was recorded in the exclusive reaction p + N ? ?(1520)K+ + N at the SPHINX facility. The branching ratio for this decay and the corresponding partial width were found to be, respectively, Br[?(1520) ? ??] = (1.02 ± 0.21) x 10-2 and ?[?(1520) ? ??] = 159 ± 35 keV (the quoted errors are purely statistical, the systematic errors being within 15%)

  4. An Equivalent Gauge and the Equivalence Theorem

    CERN Document Server

    Wulzer, Andrea

    2014-01-01

    I describe a novel covariant formulation of massive gauge theories in which the longitudinal polarization vectors do not grow with the energy. Therefore in the present formalism, differently from the ordinary one, the energy and coupling power-counting is completely transparent at the level of individual Feynman diagrams, with obvious advantages both at the conceptual and practical level. Since power-counting is transparent, the high-energy limit of the amplitudes involving longitudinal particles is immediately taken, and the Equivalence Theorem is easily demonstrated at all orders in perturbation theory. Since the formalism makes the Equivalence Theorem self-evident, and because it is based on a suitable choice of the gauge, we can call it an "Equivalent Gauge".

  5. An Equivalent Gauge and the Equivalence Theorem

    International Nuclear Information System (INIS)

    I describe a novel covariant formulation of massive gauge theories in which the longitudinal polarization vectors do not grow with the energy. Therefore in the present formalism, differently from the ordinary one, the energy and coupling power-counting is completely transparent at the level of individual Feynman diagrams, with obvious advantages both at the conceptual and practical level. Since power-counting is transparent, the high-energy limit of the amplitudes involving longitudinal particles is immediately taken, and the Equivalence Theorem is easily demonstrated at all orders in perturbation theory. Since the formalism makes the Equivalence Theorem self-evident, and because it is based on a suitable choice of the gauge, we can call it an “Equivalent Gauge”

  6. Width of laminar laboratory rivers.

    Science.gov (United States)

    Seizilles, G; Devauchelle, O; Lajeunesse, E; Métivier, F

    2013-05-01

    A viscous fluid flowing over plastic grains spontaneously generates single-thread channels. With time, these laminar analogues of alluvial rivers reach a reproducible steady state, showing a well-defined width and cross section. In the absence of sediment transport, their shape conforms with the threshold hypothesis which states that, at equilibrium, the combined effects of gravity and flow-induced stress maintain the bed surface at the threshold of motion. This theory explains how the channel selects its size and slope for a given discharge. In this light, laboratory rivers illustrate the similarity between the avalanche angle of granular materials and Shields's criterion for sediment transport. PMID:23767527

  7. Formation of Raman Scattering Wings around H alpha, H beta, and Pa alpha in Active Galactic Nuclei

    Science.gov (United States)

    Chang, Seok-Jun; Heo, Jeong-Eun; Di Mille, Francesco; Angeloni, Rodolfo; Palma, Tali; Lee, Hee-Won

    2015-12-01

    Powered by a supermassive black hole with an accretion disk, the spectra of active galactic nuclei (AGNs) are characterized by prominent emission lines including Balmer lines. The unification schemes of AGNs require the existence of a thick molecular torus that may hide the broad emission line region from the view of observers near the equatorial direction. In this configuration, one may expect that the far-UV radiation from the central engine can be Raman scattered by neutral hydrogen to reappear around Balmer and Paschen emission lines, which can be identified with broad wings. We produce H?, H?, and Pa? wings using a Monte Carlo technique to investigate their properties. The neutral scattering region is assumed to be a cylindrical torus specified by the inner and outer radii and the height. While the covering factor of the scattering region affects the overall strengths of the wings, the wing widths are primarily dependent on the neutral hydrogen column density {N}{{H} {{I}}} being roughly proportional to {N}{{H} {{I}}}1/2. In particular, with {N}{{H} {{I}}}={10}23 {{cm}}-2 the H? wings typically show a width ? 2× {10}4 {km} {{{s}}}-1. We also find that H? and Pa? wing profiles are asymmetric with the red part stronger than the blue part and an opposite behavior is seen for H? wings.

  8. Characterization of revenue equivalence

    OpenAIRE

    Heydenreich, Birgit; Müller, Rudolf; Uetz, Marc

    2007-01-01

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

  9. Hydrodynamical and radiative modeling of temporal H{\\alpha} emission V/R variations caused by a discontinuous mass transfer in binaries

    OpenAIRE

    Chadima, Pavel; Firt, Roman; Harmanec, Petr; Wolf, Marek; Ruzdjak, Domagoj; Bozic, Hrvoje; Koubsky, Pavel

    2011-01-01

    H{\\alpha} emission V/R variations caused by a discontinous mass transfer in interacting binaries with a rapidly rotating accreting star are modelled qualititatively for the first time. The program ZEUS-MP was used for a non-linear 3-D hydrodynamical modeling of a development of a blob of gaseous material injected into an orbit around a star. It resulted in the formation of an elongated disk with a slow prograde revolution. The LTE radiative transfer program SHELLSPEC was used to calculate the...

  10. Ultra Low-Frequency Oscillations of a Solar Filament in H{\\alpha} Revealed With the Data of the Global Oscillation Network Group (Gong)

    CERN Document Server

    Efremov, V I; Soloviev, A A

    2016-01-01

    The data of ground-based telescopes of Global Oscillation Network Group (GONG) obtained in the H-alpha line provide an opportunity to study the long-period oscillations of chromospheric filaments (quiescent prominence). For the first time, on the base of time-series of 5 days duration, combined from the observations of three observatories of the GONG, a new ultra-low mode, with period between 20 and 30 hours, was reliably detected in oscillations of a long-lived dark filament on the solar disc.

  11. V, R, I and H$\\alpha$ photometry of circumnuclear star forming regions in four galaxies with different levels of nuclear activity

    CERN Document Server

    Díaz, A I; Terlevich, E; Terlevich, R J; Sánchez-Portál, M; Aretxaga, I; Diaz, Angeles I.; Alvarez, Mar Alvarez; Terlevich, Elena; Terlevich, Roberto; Portal, Miguel Sanchez; Aretxaga, Itziar

    1999-01-01

    V,R,I continuum bands and Halpha + [NII] photometry for circumnuclear star forming regions (CNSFR) is presented, for galaxies with different kinds of nuclear activity: NGC 7469 (Sy 1), NGC 1068 (Sy 2), NGC 7177 (LINER) and NGC 3310 (Starburst). Their Halpha luminosities (0.02 - 7x10**40 erg/s; uncorrected for internal extinction), are comparable to those observed in other galaxies. No systematic differences in the broad band colours are found for the CNSFR in the different galaxies, except for those in NGC 3310 which are considerably bluer, partially due to a younger stellar population. Using theoretical evolutionary synthesis models some colours can be reproduced by single populations (between 7 and 300 Myr) and extinction 0.5-1.5 mag). However, in many cases, the observed equivalent width of Halpha, require a younger population. NGC 1068, 7177 and 7469, are fitted by a two-burst population model at solar metallicity; the age difference between both populations is around 5-7 Myr and the younger burst involve...

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

    CERN Document Server

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

    2015-01-01

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

  13. Heteronuclear relayed E.COSY revisited: determination of 3J(H(alpha),C(gamma)) couplings in Asx and aromatic residues in proteins.

    Science.gov (United States)

    Löhr, F; Pérez, C; Köhler, R; Rüterjans, H; Schmidt, J M

    2000-09-01

    Constant-time 3D heteronuclear relayed E.COSY [Schmidt et al. (1996) J. Biomol. NMR, 7, 142-152], as based on generic 2D small-flip-angle HMQC-COSY [Schmidt et al. (1995) J. Biomol. NMR, 6, 95-105], has been modified to allow for quantitative determination of heteronuclear three-bond 3J(H(alpha),C(gamma)) couplings. The method is applicable to amino acid spin topologies with carbons in the gamma position which lack attached protons, i.e. to asparagine, aspartate, and aromatic residues in uniformly 13C-enriched proteins. The pulse sequence critically exploits heteronuclear triple-quantum coherence (HTQC) of CH2 moieties involving geminal H(beta) proton pairs, taking advantage of improved multiple-quantum relaxation properties, at the same time avoiding scalar couplings between those spins involved in multiple-quantum coherence, thus yielding E.COSY-type multiplets with a splitting structure that is simpler than with the original scheme. Numerical least-squares 2D line-shape simulation is used to extract 3J(H(alpha),C(gamma)) coupling constants which are of relevance to side-chain chi1 dihedral-angle conformations in polypeptides. Methods are demonstrated with recombinant 15N,13C-enriched ribonuclease T1 and Desulfovibrio vulgaris flavodoxin with bound oxidized FMN. PMID:11061224

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

    CERN Document Server

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

    2015-01-01

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

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

    CERN Document Server

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

    2014-01-01

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

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

    CERN Document Server

    Metzger, Brian D; Berger, Edo

    2012-01-01

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

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

    CERN Document Server

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

    2013-01-01

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

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

    CERN Document Server

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

    2016-01-01

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

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

    CERN Document Server

    Ricahrdson, Noel D; Gies, Douglas R; Markova, N; Hesselbach, Erica N; Percy, J R

    2011-01-01

    P Cygni is a prototype of the Luminous Blue Variables (or S Doradus variables), and the star displays photometric and emission line variability on a timescale of years (known as the "short S Doradus phase" variations). Here we present new high resolution H-alpha spectroscopy of P Cyg that we combine with earlier spectra and concurrent V-band photometry to document the emission and continuum flux variations over a 24 y time span. We show that the emission and continuum fluxes vary in concert on timescales of 1.6 y and longer, but differ on shorter timescales. The H-alpha profile shape also varies on the photometric timescales, and we describe the observed co-variations of the emission peak and absorption trough properties. We argue that the episodes of photometric and emission brightening are caused by increases in the size of the emission region that are related to variations in wind mass loss rate and outflow speed. We find evidence of blueward accelerating, Discrete Absorption Components (DACs) in the absor...

  20. On the nature of H$\\alpha$ emitters at $z \\sim 2$ from the HiZELS survey: physical properties, Ly$\\alpha$ escape fraction, and main sequence

    CERN Document Server

    Oteo, I; Ivison, R J; Smail, I; Best, P N; Cepa, J; Pérez-García, A M

    2015-01-01

    We present a detailed multi-wavelength study (from rest-frame UV to far-IR) of narrow-band (NB) selected, star-forming (SF) H$\\alpha$ emitters (HAEs) at $z \\sim 2.23$ taken from the High Redshift(Z) Emission Line Survey (HiZELS). We find that HAEs have similar SED-derived properties and colors to $sBzK$ galaxies and probe a well-defined portion of the SF population at $z \\sim 2$. This is not true for Ly$\\alpha$ emitters (LAEs), which are strongly biased towards blue, less massive galaxies (missing a significant percentage of the SF population). Combining our H$\\alpha$ observations with matched, existing Ly$\\alpha$ data we determine that the Ly$\\alpha$ escape fraction ($f_{\\rm esc}$) is low (only $\\sim$ 4.5\\% of HAEs show Ly$\\alpha$ emission) and decreases with increasing dust attenuation, UV continuum slope, stellar mass, and star formation rate (SFR). This suggests that Ly$\\alpha$ preferentially escapes from blue galaxies with low dust attenuation. However, a small population of red and massive LAEs is also ...

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

    CERN Document Server

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

    2013-01-01

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

  2. Topics in orbit equivalence

    CERN Document Server

    Kechris, Alexander S

    2004-01-01

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

  3. Phage pilH alpha: a phage which adsorbs to IncHI and IncHII plasmid-coded pili.

    Science.gov (United States)

    Coetzee, J N; Bradley, D E; Fleming, J; du Toit, L; Hughes, V M; Hedges, R W

    1985-05-01

    Phage pilH alpha was specific for bacterial strains, of various genera, harbouring plasmids of the HI and HII incompatibility groups. Plaque formation was temperature sensitive in that plaques formed at 26 degrees C but not at 37 degrees C. Plaques were fairly clear, irregular in outline and varied from pin point to about 2 mm in diameter on all hosts where plaques were detected. The phage had an isometric hexagonal outline with a diameter of 25 nm. It contained RNA but differed from all but one other plasmid-dependent RNA phage by being sensitive to chloroform. It adsorbed along the length of the shafts of IncHI and HII plasmid-coded pili. PMID:2862220

  4. A high-precision pulse-width modulator source

    International Nuclear Information System (INIS)

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

  5. Gluing derived equivalences together

    CERN Document Server

    Asashiba, Hideto

    2012-01-01

    The Grothendieck construction of a diagram X of categories can be seen as a process to construct a single category Gr(X) by gluing categories in the diagram together. Here we formulate diagrams of categories as oplax functors from a small category I to the 2-category k-Cat of small k-categories for a fixed commutative ring k. In our previous paper we defined derived equivalences of those oplax functors. Roughly speaking two oplax functors X, X' : I \\to k-Cat are derived equivalent if there exist a family of triangle equivalences F(i) from the derived categories D(Mod X(i)) to D(Mod X'(i)) indexed by the objects i in I such that for each morphism a : i \\to j in I F(j)D(Mod X)(a) is naturally isomorphic to D(Mod X')(a)F(i), where D(Mod X)(a) : D(Mod X(i)) \\to D(Mod X'(i)) is given by the left derived tensor product with an X(i)-X'(i)-bimodule \\bar{X(a)} naturally defined by the functor X(a) : X(i) \\to X(j). In this paper we glue the derived equivalences F(i) together to obtain a derived equivalence between Grot...

  6. Multiscale shape equivalence

    Science.gov (United States)

    Forte, Peter; Greenhill, Darrel

    1996-09-01

    In this paper we define a property applied to contours and 2D shapes we call `shape equivalence', or more strictly, `virtual shape equivalence'. The intuitive idea is that two contours or 2D shapes are `virtually equivalent' (at a given scale of resolution) if they can possibly give rise to identical area sampled images (at the given scale) with respect to a given sampling regime. The word `virtual' is used because the relationship is not a true equivalence relation--in particular it is not strictly transitive. The idea is similar to the psychological notion of `just noticeable difference' (JND). Two stimuli are within a JND threshold if a subject cannot perceptually distinguish them, even though they may in fact be different. Similarly our notion of virtual equivalence of contours corresponds to there being no noticeable difference between them with respect to a certain class of sampling regimes at a particular scale of resolution. The usefulness of the concept is that it can be used to built a formal theory of shape and contour simplification (at various scales) to assist object recognition.

  7. Effects of the $\\gamma-$rays Scattered Backward by Metals on the Nuclear Energy Level Width

    CERN Document Server

    Cheon, I T; Cheon, Il-Tong; Jeong, Moon Taeg

    2006-01-01

    By placing a ${}^{133}Cs$ $\\gamma$-ray source embedded in a solid at the center of a platinum (gold) cylinder, we try to change the width of the 81-keV level. Our results show a narrowed energy level and, equivalently, a prolonged lifetime. With a 0.5-mm-thick, 5-cm-long, 2-mm-diameter platinum cylinder, we obtain a width narrower by $6.1 % $ at $4.2 \\: K$.

  8. Supersymmetric decay widths of weak bosons

    International Nuclear Information System (INIS)

    The partial widths of W and Z decays to supersymmetric particles are evaluated in the simplest N = 1 supergravity model. The total widths can be 50% greater than the standard-model predictions. Measurements of the widths at the p-barp collider can thereby be used either to place improved lower limits on gaugino, scalar-quark, and scalar-lepton masses or to provide indirect evidence for supersymmetry

  9. Variation of Fe Kalpha line equivalent width for orbiting spot around black hole.

    Czech Academy of Sciences Publication Activity Database

    Dov?iak, Michal; Karas, Vladimír; Matt, G.; Goosmann, René

    2008-01-01

    Ro?. 79, ?. 1 (2008), s. 248-249. ISSN 0037-8720 R&D Projects: GA ?R GP205/05/P525 Institutional research plan: CEZ:AV0Z10030501 Keywords : black holes Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

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

    Energy Technology Data Exchange (ETDEWEB)

    Roedal, Jan; Soevik, Aaste; Malinen, Eirik (Dept. of Medical Physics, The Norwegian Radium Hospital, Oslo Univ. Hospital, Oslo (Norway)), E-mail: jan.rodal@radiumhospitalet.no

    2010-10-15

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

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

    International Nuclear Information System (INIS)

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

  12. 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

  13. The principle of equivalence

    International Nuclear Information System (INIS)

    Principle of equivalence was the fundamental guiding principle in the formulation of the general theory of relativity. What are its key elements? What are the empirical observations which establish it? What is its relevance to some new experiments? These questions are discussed in this article. (author). 11 refs., 5 figs

  14. Equivalent Quantum Circuits

    CERN Document Server

    Garcia-Escartin, Juan Carlos

    2011-01-01

    Quantum algorithms and protocols are often presented as quantum circuits for a better understanding. We give a list of equivalence rules which can help in the analysis and design of quantum circuits. As example applications we study quantum teleportation and dense coding protocols in terms of a simple XOR swapping circuit and give an intuitive picture of a basic gate teleportation circuit.

  15. Equivalence of Mechanical Systems.

    Czech Academy of Sciences Publication Activity Database

    Moog, C.H.; Zikmund, Ji?í; ?elikovský, S.

    Foz do Iguassu : IFAC, 2007, 1/4-4/4. [SSSC 2007. Foz do Iguassu (BR), 17.10.2007-19.10.2007] Grant ostatní: GA MŠk(CZ) LA298 Institutional research plan: CEZ:AV0Z10750506 Keywords : Mechanical Systems * State Equivalent * Embeded Dynamics Subject RIV: BC - Control Systems Theory

  16. Understanding Equivalent Fractions.

    Science.gov (United States)

    Hunting, Robert P.

    1984-01-01

    Twenty-nine students in grades four, six, and eight were asked to find solutions to fraction equivalence problems and to verify their solutions using discrete material. Discontinuities were observed between strategies students used for producing solutions and supporting knowledge grounded in physical reality. (Author/MNS)

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

    Science.gov (United States)

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

    2015-11-01

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

  18. 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

  19. 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

  20. Alliances and Bisection Width for Planar Graphs

    DEFF Research Database (Denmark)

    Olsen, Martin; Revsbæk, Morten

    polynomial time. We base this on a proof of an upper bound of n on the bisection width for 4-connected planar graphs with an odd number of vertices. This improves a recently published n?+?1 upper bound on the bisection width of planar graphs without separating triangles and supports the folklore conjecture...

  1. Plutonium 239 Equivalency Calculations

    International Nuclear Information System (INIS)

    This document provides the basis for converting actual weapons grade plutonium mass to a plutonium equivalency (PuE) mass of Plutonium 239. The conversion can be accomplished by performing calculations utilizing either: (1) Isotopic conversions factors (CFisotope), or (2) 30-year-old weapons grade conversion factor (CF30yr) Both of these methods are provided in this document. Material mass and isotopic data are needed to calculate PuE using the isotopic conversion factors, which will provide the actual PuE value at the time of calculation. PuE is the summation of the isotopic masses times their associated isotopic conversion factors for plutonium 239. Isotopic conversion factors are calculated by a normalized equation, relative to Plutonium 239, of specific activity (SA) and cumulated dose inhalation affects based on 50-yr committed effective dose equivalent (CEDE). The isotopic conversion factors for converting weapons grade plutonium to PuE are provided in Table-1. The unit for specific activity (SA) is curies per gram (Ci/g) and the isotopic SA values come from reference (1). The cumulated dose inhalation effect values in units of rem/Ci are based on 50-yr committed effective dose equivalent (CEDE). A person irradiated by gamma radiation outside the body will receive a dose only during the period of irradiation. However, following an intake by inhalation, some radionuclides persist in the body and irradiate the various tissues for many years. There are three groups CEDE data representing lengths of time of 0.5 (D), 50 (W) and 500 (Y) days, which are in reference (2). The CEDE values in the (W) group demonstrates the highest dose equivalent value; therefore they are used for the calculation.

  2. On the holographic width of flux tubes

    CERN Document Server

    Giataganas, Dimitrios

    2015-01-01

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

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

    CERN Document Server

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

    2016-01-01

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

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

    CERN Document Server

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

    2015-01-01

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

  5. Equivalences of coisotropic submanifolds

    DEFF Research Database (Denmark)

    Schaetz, Florian; Zambon, Marco

    2014-01-01

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

  6. Line width of Josephson flux flow oscillators

    DEFF Research Database (Denmark)

    Koshelets, V.P.; Dmitriev, P.N.; Sobolev, A.S.; Pankratov, A.L.; Khodos, V.V.; Vaks, V.L.; Baryshev, A.M.; Wesselius, P.R.; Mygind, Jesper

    2002-01-01

    A combination of wide-band electronic tunability and moderate free-running line width makes the Josephson flux flow oscillator (FFO) a perfect on-chip local oscillator for integrated submillimeter-wave SIS receivers. The possibility of FFO phase locking at all frequencies of interest has to be proven before one initiates real FFO applications. To achieve this goal a comprehensive set of line width measurements of the FFO operating in different regimes has been performed. FFOs with tapered shape ...

  7. Infinite-dimensional generalization of Kolmogorov widths

    OpenAIRE

    Kounchev, Ognyan

    2011-01-01

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

  8. Establishing Substantial Equivalence: Proteomics

    Science.gov (United States)

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

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

  9. Stuttering Equivalence for Parity Games

    CERN Document Server

    Cranen, Sjoerd; Willemse, Tim A C

    2011-01-01

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

  10. 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.

  11. Coarse Equivalences of Euclidean Buildings

    OpenAIRE

    Kramer, Linus; Weiss, Richard M; Schillewaert, Jeroen; Struyve, Koen

    2009-01-01

    We prove the following rigidity results. Coarse equivalences between Euclidean buildings preserve spherical buildings at infinity. If all irreducible factors have dimension at least two, then coarsely equivalent Euclidean buildings are isometric (up to scaling factors). If in addition none of the irreducible factors is a Euclidean cone, then the isometry is unique and has finite distance from the coarse equivalence.

  12. Constraints on widths of mixed pentaquark multiplets

    CERN Document Server

    Mohta, V

    2004-01-01

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

  13. Measured, calculated and estimated stark width values

    International Nuclear Information System (INIS)

    The main objective of this study is to compare the recent experimental and theoretical Stark HWHM (half-width at half intensity maximum) results with the values that follow from previously established regularities. This comparison has been done for all Stark widths of spectral lines of ions along the isoelectronic sequence of lithium for 3s 2S-3p 2P0 transition. It has been shown that the Equation (2) can be used for simple, quick and reliable estimation of Stark widths along the lithium isoelectronic sequence for 3s-3p transition. Therefore, Equation (1) is recommended to be applied to the other isoelectronic and iso nuclear sequence for different types of transitions. (author)

  14. The Variable Line Width of Achernar

    CERN Document Server

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

    2016-01-01

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

  15. High Fin Width Mosfet Using Gaa Structure

    Directory of Open Access Journals (Sweden)

    S.L.Tripathi

    2012-10-01

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

  16. High Fin Width Mosfet Using Gaa Structure

    Directory of Open Access Journals (Sweden)

    S.L.Tripathi

    2012-11-01

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

  17. 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)

  18. Semileptonic width ratios among beauty hadrons

    OpenAIRE

    Bigi, I. I.; Mannel, Th.(Theoretische Physik 1, Naturwissenschaftlich-Technische Fakultät, Universität Siegen, Walter-Flex-Straße 3, D-57068, Siegen, Germany); Uraltsev, N.

    2011-01-01

    We present predictions based on the heavy quark expansion in QCD. We find SU(3) breaking in B mesons suppressed in the framework of the HQE. B_s is expected to have the semileptonic width about 1% lower and Lambda_b about 3% higher when compared to Gamma_{sl}(B_d). The largest partial-rate preasymptotic effect is Pauli interference in the b-->u ell nu channel in Lambda_b, about +10%. We point out that the Omega_b semileptonic width is expected not to exceed that of B_d and m...

  19. Effective spectrum width of the synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Bagrov, V.G. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); SB RAS, Institute of High Current Electronics, Tomsk (Russian Federation); Gitman, D.M. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); University of Sao Paulo, Institute of Physics, Sao Paulo (Brazil); P.N. Lebedev Physical Institute, Moscow (Russian Federation); Levin, A.D. [University of Sao Paulo, Institute of Physics, Sao Paulo (Brazil); Loginov, A.S.; Saprykin, A.D. [Tomsk State University, Department of Physics, Tomsk (Russian Federation)

    2015-11-15

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

  20. The Higgs Boson Width is Adjustable

    OpenAIRE

    Chivukula, R. Sekhar; Dugan, Michael J.; Golden, Mitchell

    1994-01-01

    We show that it is possible to construct models in which the width of the Higgs boson is arbitrary - either smaller or larger than a standard model Higgs boson of the same mass. There are no new fields into which the Higgs boson decays. Instead, the coupling of the Higgs boson to the gauge bosons is adjusted. We construct and analyze weakly--coupled models with arbitrary--width Higgs bosons to investigate the phenomenology one might find in a strongly interacting model. In a...

  1. Beyond Hypertree Width: Decomposition Methods Without Decompositions

    CERN Document Server

    Chen, H; Chen, Hubie; Dalmau, Victor

    2005-01-01

    The general intractability of the constraint satisfaction problem has motivated the study of restrictions on this problem that permit polynomial-time solvability. One major line of work has focused on structural restrictions, which arise from restricting the interaction among constraint scopes. In this paper, we engage in a mathematical investigation of generalized hypertree width, a structural measure that has up to recently eluded study. We obtain a number of computational results, including a simple proof of the tractability of CSP instances having bounded generalized hypertree width.

  2. ${^3{\\rm He}}(\\alpha,\\gamma){^7{\\rm Be}}$ and ${^3{\\rm H}}(\\alpha,\\gamma){^7{\\rm Li}}$ astrophysical $S$ factors from the no-core shell model with continuum

    CERN Document Server

    Dohet-Eraly, Jérémy; Quaglioni, Sofia; Horiuchi, Wataru; Hupin, Guillaume; Raimondi, Francesco

    2015-01-01

    The ${^3{\\rm He}}(\\alpha,\\gamma){^7{\\rm Be}}$ and ${^3{\\rm H}}(\\alpha,\\gamma){^7{\\rm Li}}$ astrophysical $S$ factors are calculated within the no-core shell model with continuum using a renormalized chiral nucleon-nucleon interaction. The ${^3{\\rm He}}(\\alpha,\\gamma){^7{\\rm Be}}$ astrophysical $S$ factors agree reasonably well with the experimental data while the ${^3{\\rm H}}(\\alpha,\\gamma){^7{\\rm Li}}$ ones are overestimated. The seven-nucleon bound and resonance states and the $\\alpha+{^3{\\rm He}}/{^3{\\rm H}}$ elastic scattering are also studied and compared with experiment. The low-lying resonance properties are rather well reproduced by our approach. At low energies, the $s$-wave phase shift, which is non-resonant, is overestimated.

  3. Bounding the Higgs boson width through interferometry.

    Science.gov (United States)

    Dixon, Lance J; Li, Ye

    2013-09-13

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

  4. Definition of the ? mass and width

    International Nuclear Information System (INIS)

    In the framework of effective field theory we show that, at two-loop order, the mass and width of the ? resonance defined via the (relativistic) Breit-Wigner parametrization both depend on the choice of field variables. In contrast, the complex-valued position of the pole of the propagator is independent of this choice

  5. Nonlocal potentials and resonances of narrow width

    International Nuclear Information System (INIS)

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

  6. Embedding a pair of graphs in a surface, and the width of 4-dimensional prismatoids

    OpenAIRE

    Santos, Francisco

    2011-01-01

    A prismatoid is a polytope with all its vertices contained in two parallel facets, called its bases. Its width is the number of steps needed to go from one base to the other in the dual graph. The author recently showed in arXiv:1006.2814 that the existence of counter-examples to the Hirsch conjecture is equivalent to that of $d$-prismatoids of width larger than $d$, and constructed such prismatoids in dimension five. Here we show that the same is impossible in dimension fou...

  7. The equivalence principle

    International Nuclear Information System (INIS)

    The prerelativistic history of the equivalence principle (EP) is presented briefly. Its role in history of the general relativity theory (G.R.T.) discovery is elucidated. A modern idea states that the ratio of inert and gravitational masses does not differ from 1 at least up to the 12 sign after comma. Attention is paid to the difference of the gravitational field from electromagnetic one. The difference is as follows, the energy of the gravitational field distributed in space is the source of the field. These fields always interact at superposition. Electromagnetic fields from different sources are put together. On the basis of EP it is established the Sun field interact with the Earth gravitational energy in the same way as with any other one. The latter proves the existence of gravitation of the very gravitational field to a heavy body. A problem on gyroscope movement in the Earth gravitational field is presented as a paradox. The calculation has shown that gyroscope at satellite makes a positive precession, and its axis turns in an angle equal to ? during a turn of the satellite round the Earth, but because of the space curvature - into the angle two times larger than ?. A resulting turn is equal to 3?. It is shown on the EP basis that the polarization plane in any coordinate system does not turn when the ray of light passes in the gravitational field. Together with the historical value of EP noted is the necessity to take into account the requirements claimed by the EP at description of the physical world

  8. Stuttering Equivalence for Parity Games

    OpenAIRE

    Cranen, Sjoerd; Keiren, Jeroen J. A.; Willemse, Tim A. C.

    2011-01-01

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

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

    International Nuclear Information System (INIS)

    We calculate decays of a standard model Higgs boson via a virtual massive particle and discuss how this depends on the massive particle total width. If the partial width for a Higgs boson to decay via a virtual massive particle can be measured, this gives a measurement of that massive particle close-quote s width. We discuss how one would go about measuring these partial widths of a Higgs boson experimentally, and how this could lead to a measurement of the W boson and t quark widths. For the latter, extreme dependence on the Higgs boson mass and the small H?tt* branching ratios mean that little can be learned about the t quark width. For the former there is also a larger dependence on the Higgs boson mass; however, this can be removed by taking the ratio of H?WW* decays to H?ZZ* decays. This ratio also has the advantage of being fairly insensitive to physics beyond the standard model. Unfortunately, for Higgs boson masses of interest the H?ZZ* branching ratio is small enough that we require many thousands of tagged Higgs boson decays before an accurate measurement of the W width can be made. This is likely to be hard experimentally. copyright 1996 The American Physical Society

  10. Testing statistical hypotheses of equivalence

    CERN Document Server

    Wellek, Stefan

    2010-01-01

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

  11. 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

  12. Numerical simulation of distorted crystal Darwin width

    International Nuclear Information System (INIS)

    A new numerical simulation method according to distorted crystal optical theory was used to predict the direct-cooling crystal monochromator optical properties(crystal Darwin width) in this study. The finite element analysis software was used to calculate the deformed displacements of DCM crystal and to get the local reciprocal lattice vector of distorted crystal. The broadening of direct-cooling crystal Darwin width in meridional direction was estimated at 4.12 ?rad. The result agrees well with the experimental data of 5 ?rad, while it was 3.89 ?rad by traditional calculation method of root mean square (RMS) of the slope error in the center line of footprint. The new method provides important theoretical support for designing and processing of monochromator crystal for synchrotron radiation beamline. (authors)

  13. 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

  14. Interface width of immiscible layered elements

    Energy Technology Data Exchange (ETDEWEB)

    Stender, Patrick; Schmitz, Guido; Ene, Constantin; Galinski, Henning [Institute of Material Physics, WWU Muenster (Germany)

    2009-07-01

    Based on the thermodynamics of inhomogeneous systems, it is expected that the chemical transition at an interface between two immiscible components cannot be atomically sharp. Recently, we could demonstrate by atom probe tomography that interfaces of metallic multilayers are indeed of finite chemical width and that this width depends systematically on temperature in thermal equilibrium. Thus, the observed effect becomes especially important for multilayer periodicities in the nanometer range. In the case of GMR devices, it can be made responsible for thermal degradation. In our work, the temperature dependence of the chemical width of layer interfaces of the binary systems Ag/Cu and Fe/Cr and the ternary system Cu/Ni81Fe19 is studied by atom probe tomography. Metallic triple and multilayers were deposited using ion beam sputter deposition technique. For all samples, an isochronal annealing was performed. Owing to the outstanding resolution of the atom probe tomography, a significant broadening of the interface is demonstrated on the depth scale between 1 and 2 nm. Because all three systems are immiscible from a thermodynamic point of view and the derived activation energies are way too small to allow an interpretation by conventional interdiffusion, Cahn-Hilliard theory is used to explain the observed temperature dependence.

  15. Equivalence of multi-norms

    OpenAIRE

    Dales, H. Garth; Daws, Matthew; Pham, Hung Le; Ramsden, Paul

    2013-01-01

    The theory of multi-norms was developed by H.\\ G.\\ Dales and M.\\ E.\\ Polyakov in a memoir that was published in \\emph{Dissertationes Mathematicae}. In that memoir, the notion of `equivalence' of multi-norms was defined. In the present memoir, we make a systematic study of when various pairs of multi-norms are mutually equivalent.

  16. SAPONIFICATION EQUIVALENT OF DASAMULA TAILA

    OpenAIRE

    Saxena, R. B.

    1994-01-01

    Saponification equivalent values of Dasamula taila are very useful for the technical and analytical work. It gives the mean molecular weight of the glycerides and acids present in Dasamula Taila. Saponification equivalent values of Dasamula taila are reported in different packings.

  17. Morita Equivalence of Noncommutative Supertori

    CERN Document Server

    Chang-Young, Ee; Nakajima, Hiroaki

    2009-01-01

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

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

    Science.gov (United States)

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

    2013-01-01

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

  19. Stimulus equivalence and supplemental measures on equivalence relations

    OpenAIRE

    Moksness, Anne-Marie

    2012-01-01

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

  20. On knot Floer width and Turaev genus

    OpenAIRE

    Lowrance, Adam

    2007-01-01

    To each knot $K\\subset S^3$ one can associated its knot Floer homology $\\hat{HFK}(K)$, a finitely generated bigraded abelian group. In general, the nonzero ranks of these homology groups lie on a finite number of slope one lines with respect to the bigrading. The width of the homology is, in essence, the largest horizontal distance between two such lines. Also, for each diagram $D$ of $K$ there is an associated Turaev surface, and the Turaev genus is the minimum genus of all...

  1. Optical spectra line width in quantum dots.

    Czech Academy of Sciences Publication Activity Database

    Král, Karel; Menšík, Miroslav

    2009-01-01

    Ro?. 6, Suppl. (2009), 513/1-513/2. ISSN 1708-5284. [International Conference on Composites or Nano Engineering/17./. Honolulu, 26.07.2009-01.08.2009] R&D Projects: GA MŠk ME 866; GA ?R GA202/07/0643 Institutional research plan: CEZ:AV0Z10100520; CEZ:AV0Z40500505 Keywords : quantum dot s * line width * optical spectra Subject RIV: BM - Solid Matter Physics ; Magnetism http://wjoe.hebeu.edu.cn/ICCE-17%20proceedings%20Hawaii%20USA/Kral,%20K.%20%28Prague,%20Czech%20Rep.%29%20%20513.pdf

  2. Morita equivalence of noncommutative supertori

    International Nuclear Information System (INIS)

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

  3. Pulse width modulation inverter with battery charger

    Science.gov (United States)

    Slicker, James M. (Inventor)

    1985-01-01

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

  4. Pion Decay Widths of D mesons

    CERN Document Server

    Henriksson, K O E; Nyfält, C J; Riska, D O

    2001-01-01

    The pionic decay rates of the excited $L=0,1$ $D$ mesons are calculated with a Hamiltonian model within the framework of the covariant Blankenbecler-Sugar {equation.} The interaction between the light quark and charm antiquark is described by a linear scalar confining and a screened one-gluon exchange interaction. The decay widths of the $D^*$ mesons obtain a contribution from the exchange current that is associated with the linear scalar confining interaction. If this contribution is taken into account along with the single quark approximation, the calculated decay rates of the charged $D^*$ mesons are readily below the current empirical upper limits if the axial coupling constant of the light constituent quarks is taken to be $g_A^q$ = 0.87, but reach the empirical upper limits if $g_A^q$ = 1. With the conventional values for $g_A^q$, the calculated widths of the $D_1$ and $D_2^*$ mesons fall somewhat below the experimental lower limits, leaving room for other decay modes as well, such as $\\pi\\pi$ decay. Th...

  5. Pulse width modulation inverter with battery charger

    Science.gov (United States)

    Slicker, James M. (Union Lake, MI)

    1985-01-01

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

  6. ICD-10 Master Equivalence Map

    Data.gov (United States)

    U.S. Department of Health & Human Services — DISCLAIMER: The Master Equivalence Map includes all existing ICD-9 and ICD-10 codes. It is not intended to be used as an ICD-10 conversion or crosswalk tool. The...

  7. Teleparallel Equivalent of Lovelock Gravity

    OpenAIRE

    Gonzalez, P A; Vasquez, Yerko

    2015-01-01

    There is a growing interest in modified gravity theories based on torsion, due to these theories, prove to exhibit interesting cosmological implications. In this work, inspired by the teleparallel formulation of General Relativity we present its extension to Lovelock Gravity known as the most natural extension of general relativity in higher-dimensional spacetimes. First, we review Teleparallel Equivalent of General Relativity and Teleparallel Equivalent of Gauss-Bonnet Grav...

  8. Stimulus equivalence and rule following

    OpenAIRE

    Hayes, Linda J.; Thompson, Scott; Hayes, Steven C.

    1989-01-01

    The present study examined the occurrence of a novel behavior pattern with respect to a novel configuration of stimuli enabled by the participation of those stimuli in equivalence classes. In Experiment 1, functional substitutabilities were established via equivalence between two independent sets of musical stimuli. Aspects of stimuli from the two sets were then compounded to produce novel stimulus configurations. Behavioral components enabled by each separate class combined to produce novel ...

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

    CERN Document Server

    Kanada-En'yo, Yoshiko; Taniguchi, Yasutaka

    2014-01-01

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

  10. Transient radiation effects of CMOS circuits with different pulse widths

    International Nuclear Information System (INIS)

    Transient radiation response on CMOS circuits were investigated for different pulse widths. CMOS circuits 4007, 4069 and 6264 were irradiated using 'Qiangguang-I' accelerator source. Latchup thresholds of CMOS inverters and upset level of CMOS SRAM with different pulse widths were obtained. The data clearly indicate dose-rate dependency on the pulse widths. The latchup threshold for 4007 and 4069 at 20 ns pulse width is 2 times that at 150 ns. The upset level for 6264 at 20 ns pulse width is 3 times that at 150 ns. The results show that the damage thresholds decrease with the increase of pulse widths. (authors)

  11. Direct measurement of the W boson width

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-09-01

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

  12. Direct measurement of the W boson width.

    Science.gov (United States)

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

    2009-12-01

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

  13. Characterizing Width Uniformity by Wave Propagation

    CERN Document Server

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

    2003-01-01

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

  14. Measurement of radiative widths at COMPASS

    International Nuclear Information System (INIS)

    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 π- beam on lead in the year 2004, about 4 million exclusive π-π-π+ events have been collected. For the 3 million events with low momentum transfer t' 2/c2, 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' 2/c2, the electromagnetic interaction part becomes apparent. The partial-wave analysis of these data leads to the observation of resonances as the a2(1320) dominantly produced by quasi-real photon exchange. The extraction of their radiative widths is presented.

  15. Frequency dependence of pulse width for 150 radio normal pulsars

    CERN Document Server

    Chen, J L

    2014-01-01

    The frequency dependence of pulse width is studied for 150 normal pulsars, mostly selected from the European Pulsar Network, of which the multi-frequency 10% pulse widths can be well fitted with the Thorsett relationship $W_{10}=A\

  16. Lake Basin Fetch and Maximum Length/Width

    Data.gov (United States)

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

  17. 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

    CERN Document Server

    Sorokin, P P

    2001-01-01

    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 make a material system transparent to resonant laser radiation, while still allowing large nonlinear resonant processes to occur with high probability. In EIT terminology, a `Lambda' configuration, involving H-atom levels (1s, 3p, and 2s), is here assumed to be operative. The EIT `coupling beam' is the narrow-band H(alpha) radiation predicted to be coherently generated via a standard `laser without inversion (LWI)' scenario when coherently phased atoms are excited to the 3p level by means of a separate nonlinear excitation process known a...

  18. 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

    CERN Document Server

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

    2007-01-01

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

  19. Teleparallel Equivalent of Lovelock Gravity

    CERN Document Server

    Gonzalez, P A

    2015-01-01

    There is a growing interest in modified gravity theories based on torsion due to these theories prove to exhibit interesting cosmological implications. In this work, inspired by the teleparallel formulation of General Relativity we present its extension to Lovelock Gravity known as the most natural extension of general relativity in higher-dimensional spacetimes. First, we review Teleparallel Equivalent of General Relativity and Teleparallel Equivalent of Gauss-Bonnet Gravity, and then we construct Teleparallel Equivalent of Lovelock Gravity. In order to achieve this goal we use the vielbein and the connection, without imposing the Weitzenb\\"ock connection. Then, we extract the teleparallel formulation of the theory by setting the curvature to be null.

  20. Matching of equivalent field regions

    DEFF Research Database (Denmark)

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

    2005-01-01

    In aperture problems, integral equations for equivalent currents are often found by enforcing matching of equivalent fields. The enforcement is made in the aperture surface region adjoining the two volumes on each side of the aperture. In the case of an aperture in a planar perfectly conducting screen, having the same homogeneous medium on both sides and an impressed current on one aide, an alternative procedure is relevant. We make use of the fact that in the aperture the tangential component of the magnetic field due to the induced currents in the screen is zero. The use of such a procedure shows that equivalent currents can be found by a consideration of only one of the two volumes into which the aperture plane divides the space. Furthermore, from a consideration of an automatic matching at the aperture, additional information about tangential as well as normal field components is obtained. We compare the two procedures in this tutorial article.

  1. Equivalence principle for scalar forces.

    Science.gov (United States)

    Hui, Lam; Nicolis, Alberto

    2010-12-01

    The equivalence of inertial and gravitational masses is a defining feature of general relativity. Here, we clarify the status of the equivalence principle for interactions mediated by a universally coupled scalar, motivated partly by recent attempts to modify gravity at cosmological distances. Although a universal scalar-matter coupling is not mandatory, once postulated, it is stable against classical and quantum renormalizations in the matter sector. The coupling strength itself is subject to renormalization, of course. The scalar equivalence principle is violated only for objects for which either the graviton self-interaction or the scalar self-interaction is important--the first applies to black holes, while the second type of violation is avoided if the scalar is Galilean symmetric. PMID:21231444

  2. Anomalous equivalence of cosmological frames

    CERN Document Server

    Herrero-Valea, Mario

    2016-01-01

    We study the question of whether two frames of a given physical theory are equivalent or not in the presence of quantum corrections. By using field theory arguments we claim that equivalence is broken in the presence of anomalous symmetries in one of the frames. This is particularized to the case of the relation between the Einstein and Jordan frames in scalar-tensor theories used to describe early Universe dynamics. Although a regularization that solves the tension exists, it requires the introduction of non-polynomial counterterms that can spoil other useful properties.

  3. Sievert, gray and dose equivalent.

    Science.gov (United States)

    Pfalzner, P M

    1983-12-01

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

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

    CERN Document Server

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

    2015-01-01

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

  5. Equivalence principle in classical electrodynamics

    CERN Document Server

    Iliev, Bozhidar Z

    2003-01-01

    The principle of equivalence in gravitational physics and its mathematical base are reviewed. It is demonstrated how this principle can be realized in classical electrodynamis. In general, it is valid at any given single point or along a path without selfintersections unless the field considered satisfies some conditions.

  6. Equivalences to the triangulation conjecture

    OpenAIRE

    Randall, Duane

    2002-01-01

    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.

  7. Acquired Equivalence Changes Stimulus Representations

    Science.gov (United States)

    Meeter, M.; Shohamy, D.; Myers, C. E.

    2009-01-01

    Acquired equivalence is a paradigm in which generalization is increased between two superficially dissimilar stimuli (or antecedents) that have previously been associated with similar outcomes (or consequents). Several possible mechanisms have been proposed, including changes in stimulus representations, either in the form of added associations or…

  8. Teaching Spelling via Stimulus Equivalences.

    Science.gov (United States)

    Lazar, Ronald M.; Mackay, Harry A.

    The study, involving two severely retarded adolescents, investigated whether matching to sample is capable of extending equivalence classes with spelling responses. In preliminary training, Ss were taught the matching to sample procedure by having them match color patch samples to identical color patch comparisons. The experimenters then trained…

  9. On graph classes with logarithmic boolean-width

    OpenAIRE

    Belmonte, Rémy; Vatshelle, Martin

    2010-01-01

    Boolean-width is a recently introduced graph parameter. Many problems are fixed parameter tractable when parametrized by boolean-width, for instance "Minimum Weighted Dominating Set" (MWDS) problem can be solved in $O^*(2^{3k})$ time given a boolean-decomposition of width $k$, hence for all graph classes where a boolean-decomposition of width $O(\\log n)$ can be found in polynomial time, MWDS can be solved in polynomial time. We study graph classes having boolean-width $O(\\log n)$ and problems...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-04-02

    A circuit generates a global clock signal with a pulse width modification to synchronize processors in a parallel computing system. The circuit may include a hardware module and a clock splitter. The hardware module may generate a clock signal and performs a pulse width modification on the clock signal. The pulse width modification changes a pulse width within a clock period in the clock signal. The clock splitter may distribute the pulse width modified clock signal to a plurality of processors in the parallel computing system.

  11. GAP WIDTH STUDY IN LASER BUTT-WELDING

    DEFF Research Database (Denmark)

    Gong, Hui; Olsen, Flemming Ove

    In this paper the maximum allowable gap width in laser butt-welding is intensively studied. The gap width study (GWS) is performed on the material of SST of W1.4401 (AISI 316) under various welding conditions, which are the gap width : 0.00-0.50 mm, the welding speed : 0.5-2.0 m/min, the laser...... power : 2 and 2.6 kW and the focal point position : 0 and -1.2 mm. Quality of all the butt welds are destructively tested according to ISO 13919-1.Influences of the variable process parameters to the maximum allowable gap width are observed as (1) the maximum gap width is inversely related to the...... welding speed, (2) the larger laser power leads to the bigger maximum allowable gap width and (3) the focal point position has very little influence on the maximum gap width....

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

    Directory of Open Access Journals (Sweden)

    Ter-Martirosyan Zaven Grigor’evich

    2013-04-01

    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. ??? ????????? ??????????? ??????? ?? ??????????? ???????? ??????????? ???????? ???????? ??? ?????? ??????? ??????? ?? ?????? ?????????? ????????. ??? ??????????? ??????? ???????????? ?????? ?????????? ????? ??????????? ? ???? ????????? ???????????? ??????? ????? ???????? ???????????? ?????????? ? ??????? ????? ???????? ?????????? ? ????????????????? ?????????.? ?????????????? ??????? ?????? ????????? ??????? ?????? ?? ??????????????? ?????? ??????????????? ????????? ? ?????? ?????????

  13. Probing high-equivalent-width nebular emission at z~7 through spectroscopic confirmation of gravitationally lensed galaxies

    Science.gov (United States)

    Clément, Benjamin; Egami, Eiichi; Richard, Johan; Schaerer, Daniel

    2015-08-01

    Gravitationally lensed high-redshift galaxies are powerful for constraining the abundance and properties of lower-luminosity galaxies in the reionization era. Here, I present the results from a spectroscopic survey of strongly lensed galaxies in massive cluster fields that resulted in the detection of the Lyman-? line for galaxies at redshifts 5.5 energy distribution from the rest-frame UV to optical and derive physical properties of this faint and distant galaxy population. However, it is now suspected that IRAC 3.6/4.5 ?m broad-band measurements of z>6 galaxies may be significantly affected by the presence of strong nebular emission lines such as H?, H?, and [O III] 4959/5007Å lines. Most notably, at 6.7free of any strong line emission. I will focus the discussion on two galaxies at z>6.7 with very blue [3.6] - [4.5] colors that cannot be explained by the stellar continuum light. This allows us to provide for the first time a clean measurement of the combined strength of these nebular emission lines at high redshift

  14. VizieR Online Data Catalog: CaII triplet equivalent widths in 30 globulars (Mauro+, 2014)

    Science.gov (United States)

    Mauro, F.; Moni Bidin, C.; Geisler, D.; Saviane, I.; da Costa, G. S.; Gormaz-Matamala, A. C.; Vasquez, S.; Chene, A.-N.; Cohen, R.; Dias, B.

    2014-03-01

    Our main target list consists of the GCs analyzed by S12 (Saviane et al., 2012, Cat. J/A+A/540/A27). The NIR imaging collected in the context of the VVV Survey was used for all clusters included in the survey area. We also checked whether any of the GCs in the dataset not observed by the VVV Survey had useful 2MASS photometry, that would permit us to determine the RHB position. We similarly selected GCs from the R97 (Rutledge et al., 1997PASP..109..907R) catalog to determine a calibration for this dataset as well (2 data files).

  15. Equivalent Imperfections In Arched Structures

    Directory of Open Access Journals (Sweden)

    Dallemule Marian

    2015-09-01

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

  16. Equivalent Imperfections In Arched Structures

    Science.gov (United States)

    Dallemule, Marian

    2015-09-01

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

  17. Equivalence Principle in Chameleon Models

    OpenAIRE

    Kraiselburd, Lucila; Landau, Susana. J.; Salgado, Marcelo; Sudarsky, Daniel

    2013-01-01

    Most theories that predict time and/or space variation of fundamental constants also predict violations of the Weak Equivalence Principle (WEP). Khoury and Weltmann proposed the chameleon model in 2004 and claimed that this model avoids experimental bounds on WEP. We present a contrasting view based on an approximate calculation of the two body problem for the chameleon field and show that the force depends on the test body composition. Furthermore, we compare the prediction of the force on a...

  18. The Stanford equivalence principle program

    Science.gov (United States)

    Worden, Paul W., Jr.; Everitt, C. W. Francis; Bye, M.

    1989-01-01

    The Stanford Equivalence Principle Program (Worden, Jr. 1983) is intended to test the uniqueness of free fall to the ultimate possible accuracy. The program is being conducted in two phases: first, a ground-based version of the experiment, which should have a sensitivity to differences in rate of fall of one part in 10(exp 12); followed by an orbital experiment with a sensitivity of one part in 10(exp 17) or better. The ground-based experiment, although a sensitive equivalence principle test in its own right, is being used for technology development for the orbital experiment. A secondary goal of the experiment is a search for exotic forces. The instrument is very well suited for this search, which would be conducted mostly with the ground-based apparatus. The short range predicted for these forces means that forces originating in the Earth would not be detectable in orbit. But detection of Yukawa-type exotic forces from a nearby large satellite (such as Space Station) is feasible, and gives a very sensitive and controllable test for little more effort than the orbiting equivalence principle test itself.

  19. The statistical distributions of level widths and conductance peaks in irregularly shaped quantum dots

    CERN Document Server

    Alhassid, Y

    1995-01-01

    Analytical expressions for width and conductance peak distributions for quantum dots with multi-channel leads in the Coulomb blockade regime are presented for both limits of conserved and broken time-reversal symmetry. The results are valid for any number of non-equivalent and correlated channels, and the distributions are expressed in terms of the channel correlation matrix M in each lead. The matrix M is also given in closed form. A chaotic billiard is used as a model to test numerically the theoretical predictions.

  20. Equivalence Relations of $AF$-Algebra Extensions

    Indian Academy of Sciences (India)

    Changguo Wei

    2010-04-01

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

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

    OpenAIRE

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

    2014-01-01

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

  2. Chemical widths at composite interfaces: Relationships to structural widths and methods for measurement

    International Nuclear Information System (INIS)

    Energy selected imaging with a Zeiss 912 ?-filter TEM was used to examine grain boundary solute distributions in an Si3N4/SiC(w) ceramic densified with Y2O3 + Al2O3 sintering aid. These results are compared to boundary region solute distributions in the same materials determined by field emission small probe electron energy loss spectroscopy and related methods. The intrinsic higher incident flux of the FEG small probe methods renders them the most useful for high spatial resolution local chemical width measurement. Energy selected imaging is fast and relatively simple for determining elemental distributions in boundaries at low magnifications. The methods are complementary

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

    OpenAIRE

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

    2012-01-01

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

  4. The Khovanov width of twisted links and closed 3-braids

    OpenAIRE

    Lowrance, Adam

    2009-01-01

    Khovanov homology is a bigraded Z-module that categorifies the Jones polynomial. The support of Khovanov homology lies on a finite number of slope two lines with respect to the bigrading. The Khovanov width is essentially the largest horizontal distance between two such lines. We show that it is possible to generate infinite families of links with the same Khovanov width from link diagrams satisfying certain conditions. Consequently, we compute the Khovanov width for all clo...

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

    Directory of Open Access Journals (Sweden)

    Strajni? Ljiljana

    2013-01-01

    Full Text Available Background/Aim. An important element of prosthetic treatment of edentulous patients is selecting the size of anterior artificial teeth that will restore the natural harmony of one’s dentolabial structure as well as the whole face. The main objective of this study was to determine the correlation between the inner canthal distance (ICD and interalar width (IAW on one side and the width of both central incisors (CIW, the width of central and lateral incisors (CLIW, the width of anterior teeth (ATW, the width between the canine cusps (CCW, which may be useful in clinical practice. Methods. A total of 89 subjects comprising 23 male and 66 female were studied. Their age ranged from 19 to 34 years with the mean of 25 years. Only the subjects with the preserved natural dentition were included in the sample. All facial and intraoral tooth measurements were made with a Boley Gauge (Buffalo Dental Manufacturing Co., Brooklyn NY, USA having a resolution of 0.1mm. Results. A moderate correlation was established between the interalar width and combined width of anterior teeth and canine cusp width (r = 0.439, r = 0.374. A low correlation was established between the inner canthal distance and the width of anterior teeth and canine cusp width (r = 0.335, r = 0.303. The differences between the two genders were highly significant for all the parameters (p < 0.01. The measured facial distances and width of anterior teeth were higher in men than in women. Conclusion. The results of this study suggest that the examined interalar width and inner canthal distance cannot be considered reliable guidelines in the selection of artificial upper anterior teeth. However, they may be used as a useful additional factor combined with other methods for objective tooth selection. The final decision should be made while working on dentures fitting models with the patient’s consent.

  6. Crack Width Analysis of Steel Fiber Reinforced Concrete Elements

    Directory of Open Access Journals (Sweden)

    Darius Ulbinas

    2011-04-01

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

  7. Nonhumans have not yet shown stimulus equivalence

    OpenAIRE

    Hayes, Steven C.

    1989-01-01

    Recently, two published articles have reported finding stimulus equivalence in nonhumans. One suggested that equivalence was due to the mediation of names. The procedure used trained all components of all tested relations. Because nothing was derived, the defining characteristics of equivalence were not achieved. In the second study a definition of equivalence was proposed that fails to distinguish functional stimulus classes from equivalence classes. The resulting data are not clearly releva...

  8. On Lower Bounds for Constant Width Arithmetic Circuits

    OpenAIRE

    Arvind, V.; Joglekar, Pushkar S.; Srinivasan, Srikanth

    2009-01-01

    The motivation for this paper is to study the complexity of constant-width arithmetic circuits. Our main results are the following. 1. For every k > 1, we provide an explicit polynomial that can be computed by a linear-sized monotone circuit of width 2k but has no subexponential-sized monotone circuit of width k. It follows, from the definition of the polynomial, that the constant-width and the constant-depth hierarchies of monotone arithmetic circuits are infinite, both in the commutative an...

  9. Upper limit on the D*(2010) decay width

    International Nuclear Information System (INIS)

    We report a measurement of the upper limit of the decay width for the D*+(2010) meson using the High Resolution Spectrometer at PEP. We observed the charged D* production in the decay mode of D*+ ? D0?+ with the D0 decaying into the K-?+ mode. The peak in the mass difference distribution M(K-?+?+)-M(K-?+) was used to directly measure the decay width. The width is dominated by the detector resolution and the preliminary result is an upper limit on the full width of ?/sub D*/ 2 at 90% C.L. 7 refs., 2 figs

  10. Temperature and spin dependence of the giant dipole resonance width

    International Nuclear Information System (INIS)

    The dependence of the GDR width on temperature and spin was investigated in Sn nuclei, by using the reactions 17O + 100Mo and 18O + 100Mo to form 117Sn and 118Sn, respectively. Widths of ?=6.9+/-0.5 MeV and ?=8.2+/-0.5 MeV were extracted for temperatures of 1.74 and 1.84 MeV, respectively. The large increase of the width over this relatively small temperature range is inconsistent with the thermal shape fluctuation model. However, the spin dependence of the width is well reproduced by the model

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

    Directory of Open Access Journals (Sweden)

    Shaker Khubab

    2015-12-01

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

  12. Blast Wave Characteristics and Equivalency

    OpenAIRE

    Sochet, Isabelle; Schneider, Helmut

    2010-01-01

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

  13. Motor Equivalence in Speech Production

    OpenAIRE

    Perrier, Pascal; Fuchs, Susanne

    2015-01-01

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

  14. Equivalence Principle in Chameleon Models

    OpenAIRE

    Kraiselburd, Lucila; Landau, Susana. J.; Salgado, Marcelo; Sudarsky, Daniel; Vucetich, Héctor

    2015-01-01

    Most theories that predict time and(or) space variation of fundamental constants also predict violations of the Weak Equivalence Principle (WEP). Khoury and Weltman proposed the chameleon model in 2004 and claimed that this model avoids experimental bounds on the WEP. In this paper we present a contrasting view based on the analysis of the force between two bodies induced by the chameleon field using a particular approach in which the field due to both the large and the small bodies is obtain...

  15. Light WIMPs And Equivalent Neutrinos

    CERN Document Server

    Steigman, Gary

    2014-01-01

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

  16. A Theory of Network Equivalence

    CERN Document Server

    Koetter, Ralf; Medard, Muriel

    2010-01-01

    A family of equivalence tools for bounding network capacities is introduced. For networks of point-to-point channels, the main result is roughly as follows. Given a network of noisy, independent, memoryless point-to-point channels, a collection of demands can be met on the given network if and only if it can be met on another network where each noisy channel is replaced by a noiseless bit pipe with throughput equal to the noisy channel capacity. This result was known previously for the case of a single-source multicast demand. The result given here treats general demands -- including, for example, multiple unicast demands -- and applies even when the achievable rate region for the corresponding demands is unknown in both the noisy network and its noiseless counterpart. The equivalence tools are also used to bound the capacity of networks containing independent channels with multiple transmitters, multiple receivers, or both. In this case, upper and lower bounding models for broadcast, multiple access, and int...

  17. Measuring Slit Width and Separation in a Diffraction Experiment

    Science.gov (United States)

    Gan, K. K.; Law, A. T.

    2009-01-01

    We present a procedure for measuring slit width and separation in single- and double-slit diffraction experiments. Intensity spectra of diffracted laser light are measured with an optical sensor (PIN diode). Slit widths and separations are extracted by fitting to the measured spectra. We present a simple fitting procedure to account for the…

  18. Quantifying River Widths of North America from Satellite Imagery

    Science.gov (United States)

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

    2013-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Chi Hong-Fu

    2013-01-01

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

  20. Crack widths in concrete with fibers and main reinforcement

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  1. Einstein's equivalence principle in cosmology

    CERN Document Server

    Kopeikin, Sergei M

    2013-01-01

    We study physical consequences of the Einstein equivalence principle (EEP) for a Hubble observer in FLRW universe. We introduce the local inertial coordinates with the help of a special conformal transformation. The local inertial metric is Minkowski flat and materialized by a congruence of time-like geodesics of static observers. The static observers are equipped with the ideal clocks measuring the proper time that is synchronized with the clocks of the Hubble observer. The local inertial metric is used for physical measurements of spacetime intervals with the ideal clocks and rulers. The special conformal transformation preserves null geodesics but does not keep invariant time-like geodesics. Moreover, it makes the rate of the local time coordinate dependent on velocity of the particle which makes impossible to rich the uniform parameterization of the world lines of static observers and light geodesics with a single parameter - they differ by the conformal factor of FLRW metric. The most convenient way to s...

  2. Expanding the Interaction Equivalency Theorem

    Directory of Open Access Journals (Sweden)

    Brenda Cecilia Padilla Rodriguez

    2015-06-01

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

  3. 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

  4. Discovering Classes of Strongly Equivalent Logic Programs

    OpenAIRE

    Chen, Y; F. Lin

    2011-01-01

    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 two rules, between t...

  5. Beyond Language Equivalence on Visibly Pushdown Automata

    DEFF Research Database (Denmark)

    Srba, Jiri

    2009-01-01

    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 all the mentioned equ...

  6. An equivalent sample circuit based on DSP

    International Nuclear Information System (INIS)

    The author introduced an equivalent sample circuit which is based on DSP. With the technology of equivalent sample this circuit can sample signal with maximum 10 GHz equivalent sample rate under the condition of 40 MHz single-shot sample rate. The author describes the design theory and its advantage

  7. Classroom Activities for Introducing Equivalence Relations

    Science.gov (United States)

    Brandt, Jim

    2013-01-01

    Equivalence relations and partitions are two interconnected ideas that play important roles in advanced mathematics. While students encounter the informal notion of equivalence in many courses, the formal definition of an equivalence relation is typically introduced in a junior level transition-to-proof course. This paper reports the results of a…

  8. Equivalence in Bilingual Lexicography: Criticism and Suggestions*

    Directory of Open Access Journals (Sweden)

    Herbert Ernst Wiegand

    2011-10-01

    Full Text Available

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

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

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

    Stichwörter: ÄQUIVALENZ, LEXIKOGRAPHISCHES ÄQUIVALENT, PARTIELLE ÄQUIVALENZ,KONGRUENZ, DIVERGENZ, KONVERGENZ, POLYDIVERGENZ, SYNTAGMENÄQUIVALENZ,NULLÄQUIVALENZ, KORRESPONDENZ

  9. Stimulus Equivalence: Testing Sidman's (2000) Theory

    Science.gov (United States)

    Minster, Sara Tepaeru; Jones, Max; Elliffe, Douglas; Muthukumaraswamy, Suresh D.

    2006-01-01

    Sidman's (2000) theory regarding the origin of equivalence relations predicts that a reinforcing stimulus common to distinct equivalence classes must drop out of the equivalence relations. This prediction was tested in the present study by arranging class-specific reinforcers, R1 and R2, following correct responding on the prerequisite conditional…

  10. Behavioural equivalence for infinite systems - Partially decidable!

    DEFF Research Database (Denmark)

    Sunesen, Kim; Nielsen, Mogens

    For finite-state systems non-interleaving equivalences are computationally at least as hard as interleaving equivalences. In this paper we show that when moving to infinite-state systems, this situation may change dramatically. We compare standard language equivalence for process description...

  11. The definition of the individual dose equivalent

    International Nuclear Information System (INIS)

    A brief note examines the choice of the present definition of the individual dose equivalent, the new operational dosimetry quantity for external exposure. The consequences of the use of the individual dose equivalent and the danger facing the individual dose equivalent, as currently defined, are briefly discussed. (UK)

  12. On the unidimensional fuzzy equivalence relations

    OpenAIRE

    Boixader Ibáñez, Dionís

    1999-01-01

    The dimension of a fuzzy equivalence relation is the minimum number of fuzzy sets needed to generate it. A general theorem is proved that characterizes unidimensional fuzzy equivalence relations. The multidimensional case is also studied under some restrictive conditions (regular fuzzy equivalence relations).

  13. Probing eigenfunction nonorthogonality by parametric shifts of resonance widths

    CERN Document Server

    Savin, D V

    2013-01-01

    Recently, it has been shown that the change of resonance widths in an open system under a perturbation of its interior is a sensitive indicator of the nonorthogonality of resonance states. We apply this measure to quantify parametric motion of the resonances. In particular, a strong redistribution of the widths is linked with the maximal degree of nonorthogonality. Then for weakly open chaotic systems we discuss the role of spectral rigidity on the statistical properties of the parametric width shifts, and derive the distribution of the latter in a picket-fence model with equidistant spectrum.

  14. Nightside studies of coherent HF Radar spectral width behaviour

    Directory of Open Access Journals (Sweden)

    E. E. Woodfield

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

    Key words. Ionosphere (auroral ionosphere; ionospheric irregularities

  15. Influence of pulse width and detuning on coherent phonon generation

    CERN Document Server

    Nakamura, Kazutaka G; Kayanuma, Yosuke

    2015-01-01

    We investigated the coherent phonon generation mechanism by irradiation of an ultrashort pulse with a simple two-level model. Our derived formulation shows that both impulsive stimulated Raman scattering (ISRS) and impulsive absorption (IA) simultaneously occur, and phonon wave packets are generated in the electronic ground and excited states by ISRS and IA, respectively. We identify the dominant process from the amplitude of the phonon oscillation. For short pulse widths, ISRS is very small and becomes larger as the pulse width increases. We also show that the initial phase is dependent on the pulse width and the detuning.

  16. Finite-width plasmonic waveguides with hyperbolic multilayer cladding

    DEFF Research Database (Denmark)

    Babicheva, Viktoriia; Shalaginov, Mikhail Y.

    2015-01-01

    Engineering plasmonic metamaterials with anisotropic optical dispersion enables us to tailor the properties of metamaterial-based waveguides. We investigate plasmonic waveguides with dielectric cores and multilayer metal-dielectric claddings with hyperbolic dispersion. Without using any homogenization, we calculate the resonant eigenmodes of the finite-width cladding layers, and find agreement with the resonant features in the dispersion of the cladded waveguides. We show that at the resonant widths, the propagating modes of the waveguides are coupled to the cladding eigenmodes and hence, are strongly absorbed. By avoiding the resonant widths in the design of the actual waveguides, the strong absorption can be eliminated. (C) 2015 Optical Society of America

  17. Nuclear widths and level shifts of a dt? mesic molecule

    International Nuclear Information System (INIS)

    Nuclear widths GITAsup(Jv) and shifts ?Esup(Jv) of dt? mesic molecule levels (Jv) due to dt s-wave resonant interaction are expressed through the d+t ? n+4He reaction cross section. It is established that the nuclear resonance 5He*(3+/2) weakly influences the spectrum of mesic molecule because of the small probability of dt being inside the range of nuclear forces in the dt?-molecule and the big inelastic width of the resonance. The nuclear widths and shifts calculated agree well with the results obtained with the generalized optical potential corresponding to the two coupled channels (dt-n4He) problem

  18. Equivalence Principle in Chameleon Models

    CERN Document Server

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

    2015-01-01

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

  19. Equivalent Simplification Method of Micro-Grid

    Directory of Open Access Journals (Sweden)

    Cai Changchun

    2013-09-01

    Full Text Available The paper concentrates on the equivalent simplification method for the micro-grid system connection into distributed network. The equivalent simplification method proposed for interaction study between micro-grid and distributed network. Micro-grid network, composite load, gas turbine synchronous generation, wind generation are equivalent simplification and parallel connect into the point of common coupling. A micro-grid system is built and three phase and single phase grounded faults are performed for the test of the equivalent model of micro-grid. The simulation results show that the equivalent model of micro-grid is effective, and the dynamic of equivalent model is similar with the detailed model of micro-grid. The equivalent simplification method for the micro-grid network and distributed components is suitable for the study of micro-grid.  

  20. 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

  1. Intraresidue 1H-15N-13C' and 1H alpha-13C alpha-13C' dipole-CSA relaxation interference as a source of constraints for structural refinement of metal-binding sites in zinc-finger proteins.

    Science.gov (United States)

    Kloiber, K; Schüler, W; Konrat, R

    2001-04-01

    1H(i)-15 N(i)-13C'(i) dipole-chemical shift anisotropy (CSA) relaxation interference was quantified for the 13C,15N labeled zinc-finger protein qCRP2(LIM2). The cross-correlation rates obtained for residues located in the metal coordination sites of qCRP2(LIM2) show a high degree of correlation with the peptide plane torsion angles phi and psi taken from the solution structure. 1H(i)-15N(i)-13C'(i) as well as 13C alpha(i)-1H alpha(i)-13C'(i) dipole-CSA cross-correlation rates were subsequently used to improve the geometry of the metal binding site. The optimized dihedral angles of the two zinc-binding sites in qCRP2(LIM2) are in better agreement with values obtained from crystal structures of other zinc-finger proteins and thus establish the utility of this approach to improve the metal-binding site geometry of zinc-finger proteins studied by NMR spectroscopy in solution. PMID:11370780

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

    CERN Document Server

    Anders, M; Bellini, A; Aliotta, M; Bemmerer, D; Broggini, C; Caciolli, A; Costantini, H; Corvisiero, P; Davinson, T; Elekes, Z; Erhard, M; Formicola, A; Fülöp, Zs; Gervino, G; Guglielmetti, A; Gustavino, C; Gyürky, Gy; Junker, M; Lemut, A; Marta, M; Mazzocchi, C; Menegazzo, R; Prati, P; Alvarez, C Rossi; Scott, D; Somorjai, E; Straniero, O; Szücs, T

    2013-01-01

    The production of the stable isotope Li-6 in standard Big Bang nucleosynthesis has recently attracted much interest. Recent observations in metal-poor stars suggest that a cosmological Li-6 plateau may exist. If true, this plateau would come in addition to the well-known Spite plateau of Li-7 abundances and would point to a predominantly primordial origin of Li-6, contrary to the results of standard Big Bang nucleosynthesis calculations. Therefore, the nuclear physics underlying Big Bang Li-6 production must be revisited. The main production channel for Li-6 in the Big Bang is the 2H(alpha,gamma)6Li reaction. The present work reports on neutron-induced effects in a high-purity germanium detector that were encountered in a new study of this reaction. In the experiment, an {\\alpha}-beam from the underground accelerator LUNA in Gran Sasso, Italy, and a windowless deuterium gas target are used. A low neutron flux is induced by energetic deuterons from elastic scattering and, subsequently, the 2H(d,n)3He reaction....

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

    CERN Document Server

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

    2015-01-01

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

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

    CERN Document Server

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

    2012-01-01

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

  5. Systematics of oscillatory behavior in hadronic masses and widths

    CERN Document Server

    Tatischeff, Boris

    2016-01-01

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

  6. Calculation of the decay width of decuplet baryons

    CERN Document Server

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

    2015-01-01

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

  7. Unprecedented grain size effect on stacking fault width

    Directory of Open Access Journals (Sweden)

    A. Hunter

    2013-09-01

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

  8. Quantum numbers and decay widths of the psi (3684)

    International Nuclear Information System (INIS)

    Cross sections for e+e-?hadrons, e+e-, and ?+?- near 3684 MeV are presented. The psi(3684) resonance is established as having the assignment J/sup PC/=1--. The mass is 3684+-5 MeV. The partial width for decay to electrons is GAMMA/sube/=2.1+-0.3 keV and the total width is GAMMA=228+-56 keV

  9. Bone Mineral Density Value Dependence on Bone Width

    Directory of Open Access Journals (Sweden)

    M. Mokhtari-Dizaji

    2006-05-01

    Full Text Available Dual x-ray absorptiometry (DXA is the most widely used measurement for the assessment of bone mass in osteoporosis. In clinical measurement, bone width can affect bone mineral parameters. The purpose of this study was to examine the dependence of bone mineral pa-rameters on bone width. In this study, DXA measurements were conducted on rabbit bone in vivo using clinical instruments. We have selected rabbit’s bones that have low BMD and more collagen tissue to predict structure not only measures BMD, but is also sensitive to the structure of the bone. To investigate the effect of bone width on the measured parameters, three regions of femur and tibia bones (N=132 were processed: upper (1/3 of length, middle (1/2 of length and lower (2/3 of length for BMC, areal BMD and volumetric BMD. The ANOVA analysis of bone mineral extracted by DXA showed significant differences (P<0.05 between BMC, BMDa and BMDv of six groups of upper, middle and lower parts of the femur and the tibia. It shows that BMC and BMD correlate well with the bone width, but BMDv inversely correlates with bone width. Linear and nonlinear regression analyses were used to examine the relationship between DXA characteristics with bone width and the regression function for each parameter is given. We concluded that BMC, areal BMD, and volumetric BMD in rabbit's bone with collagen fibers more than bone mineral are dependent on bone width. This result may be at least in part due to large precision error measurement of the bone width, in vivo.

  10. Laryngeal air column width ratio in predicting post extubation stridor

    Directory of Open Access Journals (Sweden)

    Pradeep M Venkategowda

    2015-01-01

    Full Text Available Aim: Correlation of upper air column width ratio in postextubation stridor patients. Materials and Methods: A prospective observational study was conducted in a tertiary hospital between January and December 2013. Patients who were admitted in Intensive Care Unit and intubated for >24 h were included (72 patients. The upper airway air column width ratio (air column width before extubation/air column width after intubation was calculated and compared in patient with or without postextubation stridor. Results: The incidence of stridor was 6.9% (5/72. The duration of mechanical ventilation was 5.60 ± 1.14 days and 3.91 ± 1.45 days in stridor and nonstridor group respectively. In all 5 patients who had stridor, the upper airway air column width ratio was 0.8 or less. Conclusion: Air column width ratio of 0.8 or less may be helpful in predicting postextubation stridor, which should be confirmed by large observational studies.

  11. Solar Imagery - GONG (H-alpha)

    Data.gov (United States)

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

  12. A comparison of equivalent moldable glasses

    Science.gov (United States)

    Symmons, Alan

    2013-09-01

    There are over one hundred types of glass that are sold as moldable grades. These moldable glasses are manufactured by a limited number of suppliers; each manufacturer with their own grade and designation. Many of these grades can be found to have groupings across the manufacturers, indicating possible equivalency. Equivalency of materials is an important consideration for an optical system as it would eliminate dependency on a single source, and generate cost competition. In order to establish optical equivalency it is necessary to establish significant similarity between materials. This paper compares moldable glass grades from several equivalent glass types from different manufacturers both theoretically and experimentally. Experimental data is based on precision glass molding of the same lens using different but equivalent grades of glass and using standard lens criteria for comparison. Conclusions on whether specific glass types are truly equivalent are then established.

  13. Enhanced effects of the Lorentz invariance and Einstein equivalence principle violation in 229Th nuclear transition

    CERN Document Server

    Flambaum, V V

    2015-01-01

    The Lorentz invariance and Einstein equivalence principle violating effects in the narrow 7.8 eV transition in 229Th nucleus may be 100 000 times larger than in atoms. This transition may be investigated using high precision laser spectroscopy methods, has a very small width, and suppressed systematic effects. Similar values of the effects are expected in 73 eV 235U nuclear transition which is coming within the reach of the laser spectroscopy. Mossbauer transitions give another possibility.

  14. The Complexity of Identifying Large Equivalence Classes

    DEFF Research Database (Denmark)

    Skyum, Sven; Frandsen, Gudmund Skovbjerg; Miltersen, Peter Bro; Binderup, Peter G.

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

  15. Is the principle of equivalence a principle?

    OpenAIRE

    Iliev, Bozhidar Z.

    1998-01-01

    The work argues the principle of equivalence to be a theorem and not a principle (in a sense of an axiom). It contains a detailed analysis of the concepts of normal and inertial frame of reference. The equivalence principle is proved to be valid (at every point and along every path) in any gravitational theory based on linear connections. Possible generalizations of the equivalence principle are pointed out.

  16. Equivalent Simplification Method of Micro-Grid

    OpenAIRE

    Cai Changchun; Cao Xiangqin

    2013-01-01

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

  17. Relations of equivalence of conditioned radioactive waste

    International Nuclear Information System (INIS)

    A compensation for the wastes remaining with the operator of a waste management center, to be given by the agent having caused the waste, may be assured by effecting a financial valuation (equivalence) of wastes. Technically and logically, this equivalence between wastes (or specifically between different waste categories) and financial valuation has been established as reasonable. In this paper, the possibility of establishing such equivalences are developed, and their suitability for waste management concepts is quantitatively expressed

  18. Dose equivalent measurements on board civil aircraft

    International Nuclear Information System (INIS)

    The ambient dose equivalent in the mixed radiation field on board civil aircraft was determined with a total relative uncertainty of 20%, using a tissue-equivalent proportional counter. The measured dose equivalent rates for flight levels 330 to 410 (corresponding to flight altitudes from 9.9 km to 12.3 km) range from 4 to 8 ?Sv/h. Information on the components of the radiation fields was obtained and special investigations with various absorber materials were performed. (orig.)

  19. The effective theory of Borel equivalence relations

    DEFF Research Database (Denmark)

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

    2010-01-01

    The study of Borel equivalence relations under Borel reducibility has developed into an important area of descriptive set theory. The dichotomies of Silver [20] and Harrington, Kechris and Louveau [6] show that with respect to Borel reducibility, any Borel equivalence relation strictly above equality on ? 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 ...

  20. Tropical rational equivalence on R^r

    OpenAIRE

    Allermann, Lars; Rau, Johannes

    2008-01-01

    We introduce an improved version of rational equivalence in tropical intersection theory which can be seen as a replacement of chapter 8 of our previous article arXiv:0709.3705v2. Using this new definition, rational equivalence is compatible with push-forwards of cycles. Moreover, we prove that every tropical cycle in R^r is equivalent to a uniquely determined affine cycle, called its degree.

  1. Bisimulations meet PCTL equivalences for probabilistic automata

    DEFF Research Database (Denmark)

    Song, Lei; Zhang, Lijun; Godskesen, Jens Chr.; Nielson, Flemming

    2013-01-01

    extension PCTL*. Various behavioral equivalences are proposed, as a powerful tool for abstraction and compositional minimization for PAs. Unfortunately, the equivalences are well-known to be sound, but not complete with respect to the logical equivalences induced by PCTL or PCTL*. The desire of a both sound...... and complete behavioral equivalence has been pointed out by Segala in [34], but remains open throughout the years. In this paper we introduce novel notions of strong bisimulation relations, which characterize PCTL and PCTL* exactly. We extend weak bisimulations that characterize PCTL and PCTL* without...

  2. The effective theory of Borel equivalence relations

    DEFF Research Database (Denmark)

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

    2010-01-01

    The study of Borel equivalence relations under Borel reducibility has developed into an important area of descriptive set theory. The dichotomies of Silver [20] and Harrington, Kechris and Louveau [6] show that with respect to Borel reducibility, any Borel equivalence relation strictly above...... 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...

  3. Micro-cavities based on width modulated SOI waveguides

    Science.gov (United States)

    Meister, Stefan; Al-Saadi, Aws; Franke, Bülent A.; Mahdi, Shaimaa; Szczambura, Miroslaw; Kuhlow, Berndt; Woggon, Ulrike; Zimmermann, Lars; Richter, Harald H.; Stolarek, David; Schrader, Sigurd K.; Eichler, Hans J.

    2011-01-01

    We have designed, fabricated and investigated one-dimensional (1D) micro-cavities in Silicon-on-Insulator (SOI) waveguides. The single mode waveguides are fabricated in a 220 nm silicon device layer. The 1D micro-cavities in Fabry-Perot structure consist of two Bragg-mirror regions formed by a sinusoidal modulation of the waveguide width. The mirror regions are separated by a sub-micron spacer. The SOI photonic structures are produced in a CMOS environment using 248 nm DUV lithography. The waveguides as well as the width modulated mirror regions are designed using a single mask and are fabricated in a shallow trench process. The transmission spectra of these width modulated micro-cavities with different mirror reflectivities and cavity lengths are investigated. Q-factors up to 855 could be observed at 1550 nm wavelength with low insertion loss of 1.9 dB. The width modulated micro-cavities, including the mirror regions, have lengths of less than 20 microns and widths of maximum 450 nm. These small foot-print cavities act as band pass filters and can be used as resonators for laser or electro-optic modulation of light.

  4. 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 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.)

  5. String-junction model and width of baryonium

    International Nuclear Information System (INIS)

    The string-junction model incorporates a selection rule (covalence rule) as a natural extension of the OZI and FWR rules. This rule forbids meson cascade decay among the different kinds of baryonium, M42, M22 and S02, where the lower (upper) index denotes the total number of quarks (junctions). Consequences of the covalence rule for variation in width of baryonium candidates in the mass range 1.4 -- 2.2 GeV are examined. A possibility is pointed out that above 2 GeV candidates with narrow width contain one or more strange quark pairs with small production cross sections (psi like baryonium), while baryonium states without strange quark pairs above 2 GeV have width broad enough and are expected to account for B anti B duality. A brief comparison is made between the string-junction model with models in the bag picture. (author)

  6. Modelling the widths of fission observables in GEF

    Directory of Open Access Journals (Sweden)

    Schmidt K.-H.

    2013-03-01

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

  7. The hadronic off-shell width of meson resonances

    CERN Document Server

    Dumm, D G; Portolés, J

    2000-01-01

    Within the resonance chiral effective theory we study the dressed propagators of the spin-1 fields, as arise from a Dyson-Schwinger resummation perturbatively constructed from loop diagrams with absorptive contributions in the s-channel. We apply the procedure to the vector pion form factor and the elastic pion-pion scattering to obtain the off-shell width of the rho_0 meson. We adopt a definition of the off-shell width of spin-1 meson resonances that satisfies the requirements of analyticity, unitarity, chiral symmetry and asymptotic behaviour ruled by QCD. To fulfil these constraints the resummation procedure cannot consist only of self-energy diagrams. Our width definition is shown to be independent of the formulation used to describe the spin-1 meson resonances.

  8. Fast Width Detection in Corridor Using Hough Transform

    Directory of Open Access Journals (Sweden)

    Mehrdad Javadi

    2012-11-01

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

  9. The width of the ? meson in the nuclear medium

    International Nuclear Information System (INIS)

    We evaluate the width of the ? meson in nuclear matter. We consider the free decay mode of the ? into three pions, which is dominated by ?? decay, and replace the ? and ? propagators by their medium-modified ones. We also take into account the quasielastic and inelastic processes induced by a vector-baryon interaction dominated by vector meson exchange, as well as the contributions coming from the ??K anti K mechanism with medium-modified K, anti K propagators. We obtain a substantial increase of the ? width in the medium, reaching a value of 121 ± 10 MeV at normal nuclear matter density for an ? at rest, which comes mainly from ?N ? ??N, ?NN ? ?NN processes associated to the dominant ? ? ?? decay mode. The value of the width increases moderately with momentum, reaching values of around 200MeV at 600MeV/c. (orig.)

  10. Steganography in Arabic Text Using Zero Width and Kashidha Letters

    Directory of Open Access Journals (Sweden)

    Ammar Odeh

    2012-07-01

    Full Text Available The need for secure communication methods has significantly increased with the explosive growth of theinternet and mobile communications. The usage of text documents has doubled several times over the pastyears especially with mobile devices. In this paper we propose a new steganography algorithm for Arabictext. The algorithm employs some letters that can be joined with other letters. These letters are theextension letter, Kashida and Zero width character. The extension letter, Kashida, does not have anychange in the word meaning if joined to other letters. Also, the Zero width character (Ctrl+ Shift +1 doesnot change the meaning. The new proposed algorithm, Zero Width and Kashidha Letters (ZKS, mitigatethe possibility to be discovered by steganoanalysis through using parallel connection and permutationfunction.

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

    Science.gov (United States)

    Koloren?, P?emysl; Sisourat, Nicolas

    2015-12-01

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

  12. Pulse Width Evolution in GRBs Evidence for Internal Shocks

    CERN Document Server

    Ramirez-Ruiz, E

    2000-01-01

    Many cosmological models of GRBs envision the energy source to be a cataclysmic stellar event leading to a relativistically expanding fireball. Particles are thought to be accelerated at shocks and produce nonthermal radiation. The highly variable temporal structure observed in most GRBs has significantly constrained models. By using different methods of statistical analysis in the time domain we find that the width of the large amplitude pulses in GRB time histories remain remarkably constant throughout the classic GRB phase. This is also true for small amplitude pulses. However, small and large pulses do not have the same pulse width within a single time history. We find a quantitative relationship between pulse amplitude and pulse width: the smaller amplitude peaks tend to be wider, with amplitude following a power law with an index of about -2.8. Internal shocks simulated by randomly selecting the Lorentz factor and energy per shell are consistent with a power law relationship. This is strong quantitative...

  13. How large is the spreading width of a superdeformed band?

    CERN Document Server

    Wilson, A N; Davidson, P M; Hussein, M S

    2005-01-01

    Recent models of the decay out of superdeformed bands can broadly be divided into two categories. One approach is based on the similarity between the tunneling process involved in the decay and that involved in the fusion of heavy ions, and builds on the formalism of nuclear reaction theory. The other arises from an analogy between the superdeformed decay and transport between coupled quantum dots. These models suggest conflicting values for the spreading width of the decaying superdeformed states. In this paper, the decay of superdeformed bands in the five even-even nuclei in which the SD excitation energies have been determined experimentally is considered in the framework of both approaches, and the significance of the difference in the resulting spreading widths is considered. The results of the two models are also compared to tunneling widths estimated from previous barrier height predictions and a parabolic approximation to the barrier shape.

  14. How large is the spreading width of a superdeformed band?

    Science.gov (United States)

    Wilson, A. N.; Sargeant, A. J.; Davidson, P. M.; Hussein, M. S.

    2005-03-01

    Recent models of the decay out of superdeformed (SD) bands can broadly be divided into two categories. One approach is based on the similarity between the tunneling process involved in the decay and that involved in the fusion of heavy ions, and it builds on the formalism of nuclear reaction theory. The other arises from an analogy between the superdeformed decay and transport between coupled quantum dots. These models suggest conflicting values for the spreading width of the decaying superdeformed states. In this paper, the decay of superdeformed bands in the five even-even nuclei in which the SD excitation energies have been determined experimentally is considered in the framework of both approaches, and the significance of the difference in the resulting spreading widths is considered. The results of the two models are also compared to tunneling widths estimated from previous barrier height predictions and a parabolic approximation to the barrier shape.

  15. Morphodynamics structures induced by variations of the channel width

    Science.gov (United States)

    Duro, Gonzalo; Crosato, Alessandra; Tassi, Pablo

    2014-05-01

    In alluvial channels, forcing effects, such as a longitudinally varying width, can induce the formation of steady bars (Olesen, 1984). The type of bars that form, such as alternate, central or multiple, will mainly depend on the local flow width-to-depth ratio and on upstream conditions (Struiksma et al., 1985). The effects on bar formation of varying the channel width received attention only recently and investigations, based on flume experiments and mathematical modelling, are mostly restricted to small longitudinal sinusoidal variations of the channel width (e.g. Repetto et al., 2002; Wu and Yeh, 2005, Zolezzi et al., 2012; Frascati and Lanzoni, 2013). In this work, we analyze the variations in equilibrium bed topography in a longitudinal width-varying channel with characteristic scales of the Waal River (The Netherlands) using two different 2D depth-averaged morphodynamic models, one based on the Delft3D code and one on Telemac-Mascaret system. In particular, we explore the effects of changing the wavelength of sinusoidal width variations in a straight channel, focusing on the effects of the spatial lag between bar formation and forcing that is observed in numerical models and laboratory experiments (e.g. Crosato et al, 2011). We extend the investigations to finite width variations in which longitudinal changes of the width-to-depth ratio are such that they may affect the type of bars that become unstable (alternate, central or multiple bars). Numerical results are qualitatively validated with field observations and the resulting morphodynamic pattern is compared with the physics-based predictor of river bar modes by Crosato and Mosselman (2009). The numerical models are finally used to analyse the experimental conditions of Wu and Yeh (2005). The study should be seen as merely exploratory. The aim is to investigate possible approaches for future research aiming at assessing the effects of artificial river widening and narrowing to control bar formation in alluvial rivers. References Crosato A. and Mosselman E., 2009. Simple physics-based predictor for the number of river bars and the transition between meandering and braiding. Water Resources Research, 45, W03424, doi: 10.1029/2008WR007242. Crosato A., Mosselman E., Desta F.B. and Uijttewaal W.S.J., 2011. Experimental and numerical evidence for intrinsic nonmigrating bars in alluvial channels. Water Resources Research, AGU, 47(3), W03511, doi 10.1029/2010WR009714. Frascati A. and Lanzoni S., 2013. A mathematical model for meandering rivers with varying width. J. Geophys. Res.Earth Surf., 118, doi:10.1002/jgrf.20084. Olesen K.W., 1984. Alternate bars in and meandering of alluvial rivers. In: River Meandering, Proc. of the Conf. Rivers '83, 24-26 Oct. 1983, New Orleans, Louisiana, U.S.A., ed. Elliott C.M., pp. 873-884, ASCE, New York. ISBN 0-87262-393-9. Repetto R., Tubino, M. and Paola C., 2002. Planimetric instability of channels with variable width. J. Fluid Mech., 457, 79-109. Struiksma N., Olesen K.W., Flokstra C. and De Vriend H.J., 1985. Bed deformation in curved alluvial channels. J. Hydraul. Res., 23(1), 57- 79. Wu F.-C. and Yeh T.-H., 2005. Forced bars induced by variations of channel width: Implications for incipient bifurcation. J. Geophys. Res., 110, F02009, doi:10.1029/2004JF000160. Zolezzi, G., R. Luchi, and M. Tubino (2012), Modeling morphodynamic processes in meandering rivers with spatial width variations, Rev. Geophys., 50, RG4005, doi:10.1029/2012RG000392.

  16. Analysis on Longitudinal Dose according to Change of Field Width

    International Nuclear Information System (INIS)

    To analyze the accuracy of tumor volume dose following field width change, to check the difference of dose change by using self-made moving car, and to evaluate practical delivery tumor dose when tomotherapy in the treatment of organ influenced by breathing. By using self-made moving car, the difference of longitudinal movement (0.0 cm, 1.0 cm, 1.5 cm, 2.0 cm) was applied and compared calculated dose with measured dose according to change of field width (1.05 cm, 2.50 cm, 5.02 cm) and apprehended margin of error. Then done comparative analysis in degree of photosensitivity of DQA film measured by using Gafchromic EBT film. Dose profile and Gamma histogram were used to measure degree of photosensitivity of DQA film. When field width were 1.05 cm, 2.50 cm, 5.02 cm, margin of error of dose delivery coefficient was -2.00%, -0.39%, -2.55%. In dose profile of Gafchromic EBT film's analysis, the movement of moving car had greater motion toward longitudinal direction and as field width was narrower, big error increased considerably at high dose part compared to calculated dose. The more field width was narrowed, gamma index had a large considerable influence of moving at gamma histogram. We could check the difference of longitudinal dose of moving organ. In order to small field width and minimize organ moving due to breathing, it is thought to be needed to develop breathing control unit and fixation tool.

  17. Analysis on Longitudinal Dose according to Change of Field Width

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Won Seok; Shin, Ryung Mi; Oh, Byung Cheon; Jo, Jun Young; Kim, Gi Chul; Choi, Tae Gu [Dept. of Radiation Oncology, Kyunghee University Hospital, Seoul (Korea, Republic of); Back, Jong Geal [Dept. of Radiation Oncology, Yensei Caner Center, Seoul (Korea, Republic of)

    2011-09-15

    To analyze the accuracy of tumor volume dose following field width change, to check the difference of dose change by using self-made moving car, and to evaluate practical delivery tumor dose when tomotherapy in the treatment of organ influenced by breathing. By using self-made moving car, the difference of longitudinal movement (0.0 cm, 1.0 cm, 1.5 cm, 2.0 cm) was applied and compared calculated dose with measured dose according to change of field width (1.05 cm, 2.50 cm, 5.02 cm) and apprehended margin of error. Then done comparative analysis in degree of photosensitivity of DQA film measured by using Gafchromic EBT film. Dose profile and Gamma histogram were used to measure degree of photosensitivity of DQA film. When field width were 1.05 cm, 2.50 cm, 5.02 cm, margin of error of dose delivery coefficient was -2.00%, -0.39%, -2.55%. In dose profile of Gafchromic EBT film's analysis, the movement of moving car had greater motion toward longitudinal direction and as field width was narrower, big error increased considerably at high dose part compared to calculated dose. The more field width was narrowed, gamma index had a large considerable influence of moving at gamma histogram. We could check the difference of longitudinal dose of moving organ. In order to small field width and minimize organ moving due to breathing, it is thought to be needed to develop breathing control unit and fixation tool.

  18. Statistical analysis of s-wave neutron reduced widths

    International Nuclear Information System (INIS)

    The fluctuations of the s-wave neutron reduced widths for many nuclei have been analyzed with emphasis on recent measurements by a statistical procedure which is based on the method of maximum likelihood. It is shown that the s-wave neutron reduced widths of nuclei follow single channel Porter Thomas distribution (x2-distribution with degree of freedom ? = 1) for most of the cases. However there are apparent deviations from ? = 1 and possible explanation and significance of this deviation is given. These considerations are likely to modify the evaluation of neutron cross section. (author)

  19. 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.)

  20. 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.)

  1. Breakdown of the Narrow Width Approximation for New Physics

    CERN Document Server

    Berdine, D; Rainwater, D L

    2007-01-01

    The narrow width approximation is used in high energy physics to reduce the complexity of scattering calculations. It is a fortunate accident that it works so well for the Standard Model, but in general it will fail in the context of new physics. We find numerous examples of significant corrections when the calculation is performed fully off-shell including a finite width, notably from effects from the decay matrix elements. If not taken into account, attempts to reconstruct the Lagrangian of a new physics discovery from data would result in considerable inaccuracies and likely inconsistencies.

  2. Experimental research methodology crack opening width of reinforced concrete elements

    Directory of Open Access Journals (Sweden)

    ?.?. ????????

    2006-01-01

    Full Text Available  The tasks of experimental researches have been formulated, basic of which are: definition of width  disclosing  cracks at a level of the working fixture and in several levels above the stretched fixture; changes of distance between cracks and length of cracks in process of increase of loading with check of multilevel process of formation cracks; definition of deformations of the fixture and concrete with deformation account of effect in a vicinity of a two-console element. The technique of experimental researches of width of disclosing cracks of ferro-concrete designs from a position of the mechanics destruction is developed which has allowed to decide the put tasks.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-01-01

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

  4. 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.)

  5. Quantum numbers and decay widths of the psi (3095)

    International Nuclear Information System (INIS)

    We present cross sections for e+e-? hadrons, e+e-, and ?+?- near 3095 MeV. The psi (3095) resonance is established as having an assignment J/supP//supC/=1--. The mass is 3095 plus-or-minus4 MeV. The partial width to electrons is GAMMA/sube/=4.8plus-or-minus0.6 keV and the total width GAMMA=69plus-or-minus15 keV. Total rates and interference measurements for the lepton channels are in accord with ?-e universality

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

    OpenAIRE

    Larin, I.; McNulty, D.; Clinton, E.; Ambrozewicz, P.; Lawrence, D.; Nakagawa, I.; Y. Prok(Old Dominion University); Teymurazyan, A.; Ahmidouch, A.; A. Asratyan; Baker, K; Benton, L.; Bernstein, A. M.; Burkert, V.; Cole, P.

    2010-01-01

    High precision measurements of the differential cross sections for $\\pi^0$ photoproduction at forward angles for two nuclei, $^{12}$C and $^{208}$Pb, have been performed for incident photon energies of 4.9 - 5.5 GeV to extract the ${\\pi^0 \\to \\gamma\\gamma}$ decay width. The experiment was done at Jefferson Lab using the Hall B photon tagger and a high-resolution multichannel calorimeter. The ${\\pi^0 \\to \\gamma\\gamma}$ decay width was extracted by fitting the measured cross sections using rece...

  7. Bisimulations Meet PCTL Equivalences for Probabilistic Automata

    DEFF Research Database (Denmark)

    Song, Lei; Zhang, Lijun; Godskesen, Jens Christian

    equivalences are proposed for PAs, asa powerful tool for abstraction and compositional minimization forPAs. Unfortunately, the behavioral equivalencesare well-known to be strictly stronger than the logical equivalences inducedby PCTL or PCTL*. This paper introduces novel notions of strongbisimulation relations...

  8. 7 CFR 1032.54 - Equivalent price.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Equivalent price. 1032.54 Section 1032.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Class Prices § 1032.54 Equivalent price. See § 1000.54. Producer Price Differential...

  9. 7 CFR 1006.54 - Equivalent price.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Equivalent price. 1006.54 Section 1006.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Class Prices § 1006.54 Equivalent price. See § 1000.54. Uniform Prices...

  10. 7 CFR 1030.54 - Equivalent price.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Equivalent price. 1030.54 Section 1030.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Class Prices § 1030.54 Equivalent price. See § 1000.54....

  11. 7 CFR 1124.54 - Equivalent price.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Equivalent price. 1124.54 Section 1124.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Regulating Handling Class Prices § 1124.54 Equivalent price. See § 1000.54. Producer Price Differential...

  12. 7 CFR 1005.54 - Equivalent price.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Equivalent price. 1005.54 Section 1005.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Class Prices § 1005.54 Equivalent price. See § 1000.54. Uniform Prices...

  13. 7 CFR 1007.54 - Equivalent price.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Equivalent price. 1007.54 Section 1007.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Class Prices § 1007.54 Equivalent price. See § 1000.54. Uniform Prices...

  14. 7 CFR 1131.54 - Equivalent price.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Equivalent price. 1131.54 Section 1131.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Class Prices § 1131.54 Equivalent price. See § 1000.54. Uniform Prices...

  15. 7 CFR 1033.54 - Equivalent price.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Equivalent price. 1033.54 Section 1033.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Class Prices § 1033.54 Equivalent price. See § 1000.54. Producer Price Differential...

  16. 7 CFR 1000.54 - Equivalent price.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Equivalent price. 1000.54 Section 1000.54 Agriculture... Prices § 1000.54 Equivalent price. If for any reason a price or pricing constituent required for computing the prices described in § 1000.50 is not available, the market administrator shall use a price...

  17. 7 CFR 1126.54 - Equivalent price.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Equivalent price. 1126.54 Section 1126.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Class Prices § 1126.54 Equivalent price. See § 1000.54. Producer Price Differential...

  18. 7 CFR 1001.54 - Equivalent price.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Equivalent price. 1001.54 Section 1001.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Class Prices § 1001.54 Equivalent price. See § 1000.54. Producer Price Differential...

  19. Mania and Behavioral Equivalents: A Preliminary Study

    Science.gov (United States)

    Sturmey, Peter; Laud, Rinita B.; Cooper, Christopher L.; Matson, Johnny L.; Fodstad, Jill C.

    2010-01-01

    Previous research has failed to address the possibility of behavioral equivalents in people with ID and mania. The relationship between a measure of mania and possible behavioral equivalents was assessed in 693 adults, most with severe or profound ID, living in a large residential setting. The mania subscale of the DASH-II proved to be a…

  20. Equivalence in Ventilation and Indoor Air Quality

    Energy Technology Data Exchange (ETDEWEB)

    Sherman, Max; Walker, Iain; Logue, Jennifer

    2011-08-01

    We ventilate buildings to provide acceptable indoor air quality (IAQ). Ventilation standards (such as American Society of Heating, Refrigerating, and Air-Conditioning Enginners [ASHRAE] Standard 62) specify minimum ventilation rates without taking into account the impact of those rates on IAQ. Innovative ventilation management is often a desirable element of reducing energy consumption or improving IAQ or comfort. Variable ventilation is one innovative strategy. To use variable ventilation in a way that meets standards, it is necessary to have a method for determining equivalence in terms of either ventilation or indoor air quality. This study develops methods to calculate either equivalent ventilation or equivalent IAQ. We demonstrate that equivalent ventilation can be used as the basis for dynamic ventilation control, reducing peak load and infiltration of outdoor contaminants. We also show that equivalent IAQ could allow some contaminants to exceed current standards if other contaminants are more stringently controlled.

  1. Calabi-Yau completions and orbifold equivalences

    CERN Document Server

    Carqueville, Nils

    2015-01-01

    Calabi-Yau algebras are particularly symmetric differential graded algebras. There is a construction due to Keller called `Calabi-Yau completion' which produces a canonical Calabi-Yau algebra from any homologically smooth dg algebra. Homologically smooth dg algebras also form a 2-category to which the construction of `equivariant completion' can be applied. In this theory two objects are called `orbifold equivalent' if there is a 1-morphism with invertible quantum dimensions between them. Any such relation entails a whole family of equivalences between categories. We show that Calabi-Yau completion and equivariant completion are compatible. More precisely, we prove that any orbifold equivalence between two homologically smooth and proper dg algebras lifts to an orbifold equivalence between their Calabi-Yau completions. As a corollary we obtain orbifold equivalences between Ginzburg algebras of Dynkin quivers.

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

    CERN Document Server

    Aubert, B; Boutigny, D; Couderc, F; Gaillard, J M; Hicheur, A; Karyotakis, Yu; Lees, J P; Tisserand, V; Zghiche, A; Palano, A; Pompili, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Borgland, A W; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Le Clerc, C; Lynch, G; Merchant, A M; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, Michael T; Shelkov, V G; Telnov, A V; Wenzel, W A; Ford, K; Harrison, T J; Hawkes, C M; Morgan, S E; Watson, A T; Fritsch, M; Goetzen, K; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Steinke, M; Boyd, J T; Chevalier, N; Cottingham, W N; Kelly, M P; Latham, T E; Wilson, F F; Çuhadar-Dönszelmann, T; Hearty, C; Mattison, T S; McKenna, J A; Thiessen, D; Kyberd, P; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Ivanchenko, V N; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Yushkov, A N; Best, D; Bruinsma, M; Chao, M; Eschrich, I; Kirkby, D; Lankford, A J; Mandelkern, M A; Mommsen, R K; Röthel, W; Stoker, D P; Buchanan, C; Hartfiel, B L; Gary, J W; Shen, B C; Wang, K; Del Re, D; Hadavand, H K; Hill, E J; MacFarlane, D B; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Dahmes, B; Levy, S L; Long, O; Lu, A; Mazur, M A; Richman, J D; Verkerke, W; Beck, T W; Eisner, A M; Heusch, C A; Lockman, W S; Schalk, T; Schmitz, R E; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dubois-Felsmann, G P; Dvoretskii, A; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Yang, S; Jayatilleke, S M; Mancinelli, G; Meadows, B T; Sokoloff, M D; Abe, T; Blanc, F; Bloom, P; Chen, S; Clark, P J; Ford, W T; Nauenberg, U; Olivas, A; Rankin, P; Smith, J G; Zhang, L; Chen, A; Harton, J L; Soffer, A; Toki, W H; Wilson, R J; Zeng, Q L; Altenburg, D; Brandt, T; Brose, J; Colberg, T; Dickopp, M; Feltresi, E; Hauke, A; Lacker, H M; Maly, E; Müller-Pfefferkorn, R; Nogowski, R; Otto, S; Petzold, A; Schubert, J; Schubert, Klaus R; Schwierz, R; Spaan, B; Sundermann, J E; Bernard, D; Bonneaud, G R; Brochard, F; Grenier, P; Schrenk, S; Thiebaux, C; Vasileiadis, G; Verderi, M; Bard, D J; Khan, A; Lavin, D; Muheim, F; Playfer, S; Andreotti, M; Azzolini, V; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Piemontese, L; Sarti, A; Treadwell, E; Baldini-Ferroli, R; Calcaterra, A; De Sangro, R; Finocchiaro, G; Patteri, P; Piccolo, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Crosetti, G; Lo Vetere, M; Macri, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Bailey, S; Brandenburg, G; Morii, M; Won, E; Dubitzky, R S; Langenegger, U; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Gaillard, J R; Morton, G W; Nash, J A; Taylor, G P; Grenier, G J; Mallik, U; Cochran, J; Crawley, H B; Lamsa, J; Meyer, W T; Prell, S; Rosenberg, E I; Yi, J; Davier, M; Grosdidier, G; Höcker, A; Laplace, S; Le Diberder, F R; Lepeltier, V; Lutz, A M; Petersen, T C; Plaszczynski, S; Schune, M H; Tantot, L; Wormser, G; Cheng, C H; Lange, D J; Simani, M C; Wright, D M; Bevan, A J; Coleman, J P; Fry, J R; Gabathuler, Erwin; Gamet, R; Parry, R J; Payne, D J; Sloane, R J; Touramanis, C; Back, J J; Cormack, C M; Harrison, P F; Mohanty, G B; Brown, C L; Cowan, G; Flack, R L; Flächer, H U; Green, M G; Marker, C E; McMahon, T R; Ricciardi, S; Salvatore, F; Vaitsas, G; Winter, M A; Brown, D; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Hart, P A; Hodgkinson, M C; Lafferty, G D; Lyon, A J; Williams, J C; Farbin, A; Hulsbergen, W D; Jawahery, A; Kovalskyi, D; Lae, C K; Lillard, V; Roberts, D A; Blaylock, G; Dallapiccola, C; Flood, K T; Hertzbach, S S; Kofler, R; Koptchev, V B; Moore, T B; Saremi, S; Stängle, H; Willocq, S; Cowan, R; Sciolla, G; Taylor, F; Yamamoto, R K; Mangeol, D J J; Patel, P M; Robertson, S H; Lazzaro, A; Palombo, F; Bauer, J M; Cremaldi, L M; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Taras, P; Nicholson, H; Cavallo, N; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M; Bulten, H; Raven, G; Wilden, L; Jessop, C P; LoSecco, J M; Gabriel, T A; Allmendinger, T; Brau, B; Gan, K K; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Pulliam, T; Rahimi, A M; Ter-Antonian, R; Wong, Q K; Brau, J E; Frey, R; Igonkina, O; Potter, C T; Sinev, N B; Strom, D; Torrence, E; Colecchia, F; Dorigo, A; Galeazzi, F; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Tiozzo, G; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; La Vaissière, C de; Del Buono, L; Hamon, O; John, M J J; Leruste, P; Ocariz, J; Pivk, M

    2004-01-01

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

  3. Pulse-width-modulated servo valve for autopilot system

    Science.gov (United States)

    Garner, H. D.

    1974-01-01

    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.

  4. Sinusoidal and Space Vector Pulse Width Modulation for Inverter

    Directory of Open Access Journals (Sweden)

    K. Mounika#1 , B. Kiran Babu

    2013-04-01

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

  5. Two-loop light quark corrections to the top width

    International Nuclear Information System (INIS)

    A method of computing two-loop fermionic contributions to the width of a heavy quark is described. An analytical formula for this effect in the limit of mass of the quark much larger than the decay products is obtained for the first time. The result confirms previous numerical studies. (author). 6 refs, 1 fig

  6. Width of the Darwin Table for Forbidden Reflections

    International Nuclear Information System (INIS)

    It is shown that reflections with structure factor equal to zero are not absent, but have very small Darwin table width, which is determined by a shift of the Bragg point and by structure factors of another type. It is pointed out that this effect cannot be obtained within the Ewald theory of dynamical diffraction on single crystals. copyright 1996 The American Physical Society

  7. Improved determination of the width of the top quark

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-05-04

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

  8. Optical line width in quantum dot or nanotransistor.

    Czech Academy of Sciences Publication Activity Database

    Král, Karel; Menšík, Miroslav

    2010-01-01

    Ro?. 8, - (2010), s. 136-140. ISSN 1348-0391 R&D Projects: GA MŠk ME 866; GA ?R GA202/07/0643 Institutional research plan: CEZ:AV0Z10100520; CEZ:AV0Z40500505 Keywords : quantum dot s * line width * optical spectra * nanotransistor Subject RIV: BM - Solid Matter Physics ; Magnetism

  9. Width of giant dipole resonance in hot nuclei

    International Nuclear Information System (INIS)

    An approach describing the width of the giant dipole resonance in hot nuclei is proposed. The numerical calculations in the schematic model with equally degenerate equidistant shells for a hot nucleus of mass A=110 carrying no angular momentum are performed which provide a good agreement with the behavior of the recent experimental data. (author). 30 refs., 5 figs

  10. The Height + Width Rule in Children's Judgments of Quantity.

    Science.gov (United States)

    Anderson, Norman H.; Cuneo, Diane O.

    1978-01-01

    In eight experiments, judgments of rectangle area by five-year-olds followed a reliable adding rule: height + width. In collateral work, the children judged the amount of liquid in a glass by a height-only rule. Implications for the Piagetian theories of centration and compensation are drawn. (SJL)

  11. On the width of collective excitations in chiral soliton models

    International Nuclear Information System (INIS)

    In chiral soliton models for baryons the computation of hadronic decay widths of baryon resonances is a long standing problem. For the three flavor Skyrme model I present a solution to this problem that satisfies large-NC consistency conditions. As an application I focus on the hadronic decay of the ? and ?* pentaquarks. (author)

  12. Harmonic orientation of pulse width modulation technique in multilevel inverters

    OpenAIRE

    Urmila Bandaru; Subba D Rayudu

    2011-01-01

    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.

  13. Dynamical Screening of Atom Confined by Finite-Width Fullerene

    OpenAIRE

    Lo, S; Korol, A. V.; Solov'yov, A V

    2007-01-01

    This is an investigation on the dynamical screening of an atom confined within a fullerene of finite width. The two surfaces of the fullerene lead to the presence of two surface plasmon eigenmodes. It is shown that, in the vicinity of these two eigenfrequencies, there is a large enhancement of the confined atom's photoabsorption rate.

  14. Estimation of the Beam Width in Magnetic Mass Spectrometer

    Directory of Open Access Journals (Sweden)

    O.N. Peregudov

    2010-01-01

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

  15. Improved determination of the width of the top quark

    Science.gov (United States)

    Abazov, V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Alverson, G.; Aoki, M.; Askew, A.; Åsman, B.; Atkins, S.; Atramentov, O.; Augsten, K.; Avila, C.; BackusMayes, J.; Badaud, F.; Bagby, L.; Baldin, B.; Bandurin, D. V.; Banerjee, S.; Barberis, E.; Baringer, P.; Barreto, J.; Bartlett, J. F.; Bassler, U.; Bazterra, V.; Bean, A.; Begalli, M.; Belanger-Champagne, C.; Bellantoni, L.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Bertram, I.; Besançon, M.; Beuselinck, R.; Bezzubov, V. A.; Bhat, P. C.; Bhatia, S.; Bhatnagar, V.; Blazey, G.; Blessing, S.; Bloom, K.; Boehnlein, A.; Boline, D.; Boos, E. E.; Borissov, G.; Bose, T.; Brandt, A.; Brandt, O.; Brock, R.; Brooijmans, G.; Bross, A.; Brown, D.; Brown, J.; Bu, X. B.; Buehler, M.; Buescher, V.; Bunichev, V.; Burdin, S.; Burnett, T. H.; Buszello, C. P.; Calpas, B.; Camacho-Pérez, E.; Carrasco-Lizarraga, M. A.; Casey, B. C. K.; Castilla-Valdez, H.; Chakrabarti, S.; Chakraborty, D.; Chan, K. M.; Chandra, A.; Chapon, E.; Chen, G.; Chevalier-Théry, S.; Cho, D. K.; Cho, S. W.; Choi, S.; Choudhary, B.; Cihangir, S.; Claes, D.; Clutter, J.; Cooke, M.; Cooper, W. E.; Corcoran, M.; Couderc, F.; Cousinou, M.-C.; Croc, A.; Cutts, D.; Das, A.; Davies, G.; de Jong, S. J.; De La Cruz-Burelo, E.; Déliot, F.; Demina, R.; Denisov, D.; Denisov, S. P.; Desai, S.; Deterre, C.; DeVaughan, K.; Diehl, H. T.; Diesburg, M.; Ding, P. F.; Dominguez, A.; Dorland, T.; Dubey, A.; Dudko, L. V.; Duggan, D.; Duperrin, A.; Dutt, S.; Dyshkant, A.; Eads, M.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Enari, Y.; Evans, H.; Evdokimov, A.; Evdokimov, V. N.; Facini, G.; Ferbel, T.; Fiedler, F.; Filthaut, F.; Fisher, W.; Fisk, H. E.; Fortner, M.; Fox, H.; Fuess, S.; Garcia-Bellido, A.; García-Guerra, G. A.; Gavrilov, V.; Gay, P.; Geng, W.; Gerbaudo, D.; Gerber, C. E.; Gershtein, Y.; Ginther, G.; Golovanov, G.; Goussiou, A.; Graf, C. P.; Grannis, P. D.; Greder, S.; Greenlee, H.; Greenwood, Z. D.; Gregores, E. M.; Grenier, G.; Gris, Ph.; Grivaz, J.-F.; Grohsjean, A.; Grünendahl, S.; Grünewald, M. W.; Guillemin, T.; Gutierrez, G.; Gutierrez, P.; Haas, A.; Hagopian, S.; Haley, J.; Han, L.; Harder, K.; Harel, A.; Hauptman, J. M.; Hays, J.; Head, T.; Hebbeker, T.; Hedin, D.; Hegab, H.; Heinson, A. P.; Heintz, U.; Hensel, C.; Heredia-De La Cruz, I.; Herner, K.; Hesketh, G.; Hildreth, M. D.; Hirosky, R.; Hoang, T.; Hobbs, J. D.; Hoeneisen, B.; Hohlfeld, M.; Hubacek, Z.; Hynek, V.; Iashvili, I.; Ilchenko, Y.; Illingworth, R.; Ito, A. S.; Jabeen, S.; Jaffré, M.; Jamin, D.; Jayasinghe, A.; Jesik, R.; Johns, K.; Johnson, M.; Jonckheere, A.; Jonsson, P.; Joshi, J.; Jung, A. W.; Juste, A.; Kaadze, K.; Kajfasz, E.; Karmanov, D.; Kasper, P. A.; Katsanos, I.; Kehoe, R.; Kermiche, S.; Khalatyan, N.; Khanov, A.; Kharchilava, A.; Kharzheev, Y. N.; Kohli, J. M.; Kozelov, A. V.; Kraus, J.; Kulikov, S.; Kumar, A.; Kupco, A.; Kur?a, T.; Kuzmin, V. A.; Lammers, S.; Landsberg, G.; Lebrun, P.; Lee, H. S.; Lee, S. W.; Lee, W. M.; Lellouch, J.; Li, H.; Li, L.; Li, Q. Z.; Lietti, S. M.; Lim, J. K.; Lincoln, D.; Linnemann, J.; Lipaev, V. V.; Lipton, R.; Liu, Y.; Lobodenko, A.; Lokajicek, M.; Lopes de Sa, R.; Lubatti, H. J.; Luna-Garcia, R.; Lyon, A. L.; Maciel, A. K. A.; Mackin, D.; Madar, R.; Magaña-Villalba, R.; Malik, S.; Malyshev, V. L.; Maravin, Y.; Martínez-Ortega, J.; McCarthy, R.; McGivern, C. L.; Meijer, M. M.; Melnitchouk, A.; Menezes, D.; Mercadante, P. G.; Merkin, M.; Meyer, A.; Meyer, J.; Miconi, F.; Mondal, N. K.; Muanza, G. S.; Mulhearn, M.; Nagy, E.; Naimuddin, M.; Narain, M.; Nayyar, R.; Neal, H. A.; Negret, J. P.; Neustroev, P.; Novaes, S. F.; Nunnemann, T.; Obrant, G.; Orduna, J.; Osman, N.; Osta, J.; Otero y Garzón, G. J.; Padilla, M.; Pal, A.; Parashar, N.; Parihar, V.; Park, S. K.; Partridge, R.; Parua, N.; Patwa, A.; Penning, B.; Perfilov, M.; Peters, Y.; Petridis, K.; Petrillo, G.; Pétroff, P.; Piegaia, R.; Pleier, M.-A.; Podesta-Lerma, P. L. M.; Podstavkov, V. M.; Polozov, P.; Popov, A. V.; Prewitt, M.; Price, D.; Prokopenko, N.; Qian, J.; Quadt, A.; Quinn, B.; Rangel, M. S.; Ranjan, K.; Ratoff, P. N.; Razumov, I.; Renkel, P.; Rijssenbeek, M.; Ripp-Baudot, I.; Rizatdinova, F.; Rominsky, M.; Ross, A.; Royon, C.; Rubinov, P.; Ruchti, R.; Safronov, G.; Sajot, G.; Salcido, P.; Sánchez-Hernández, A.; Sanders, M. P.; Sanghi, B.; Santos, A. S.; Savage, G.; Sawyer, L.; Scanlon, T.; Schamberger, R. D.; Scheglov, Y.; Schellman, H.; Schliephake, T.; Schlobohm, S.; Schwanenberger, C.; Schwienhorst, R.; Sekaric, J.; Severini, H.; Shabalina, E.; Shary, V.; Shchukin, A. A.; Shivpuri, R. K.; Simak, V.; Sirotenko, V.; Skubic, P.; Slattery, P.; Smirnov, D.; Smith, K. J.; Snow, G. R.; Snow, J.; Snyder, S.; Söldner-Rembold, S.; Sonnenschein, L.

    2012-05-01

    We present an improved determination of the total width of the top quark, ?t, using 5.4fb-1 of integrated luminosity collected by the D0 Collaboration at the Tevatron pp¯ Collider. The total width ?t is extracted from the partial decay width ?(t?Wb) and the branching fraction B(t?Wb). ?(t?Wb) is obtained from the t-channel single top-quark production cross section and B(t?Wb) is measured in tt¯ events. For a top mass of 172.5 GeV, the resulting width is ?t=2.00-0.43+0.47GeV. This translates to a top-quark lifetime of ?t=(3.29-0.63+0.90)×10-25s. We also extract an improved direct limit on the Cabibbo-Kobayashi-Maskawa quark-mixing matrix element 0.81<|Vtb|?1 at 95% C.L. and a limit of |Vtb'|<0.59 for a high-mass fourth-generation bottom quark assuming unitarity of the fourth-generation quark-mixing matrix.

  16. An Improved determination of the width of the top quark

    Energy Technology Data Exchange (ETDEWEB)

    Abazov, Victor Mukhamedovich; /Dubna, JINR; Abbott, Braden Keim; /Oklahoma U.; Acharya, Bannanje Sripath; /Tata Inst.; Adams, Mark Raymond; /Illinois U., Chicago; Adams, Todd; /Florida State U.; Alexeev, Guennadi D.; /Dubna, JINR; Alkhazov, Georgiy D.; /St. Petersburg, INP; Alton, Andrew K.; /Michigan U. /Augustana Coll., Sioux Falls; Alverson, George O.; /Northeastern U.; Aoki, Masato; /Fermilab; Askew, Andrew Warren; /Florida State U. /Stockholm U.

    2012-01-01

    We present an improved determination of the total width of the top quark, {Lambda}{sub t}, using 5.4 fb{sup -1} of integrated luminosity collected by the D0 Collaboration at the Tevatron p{bar p} Collider. The total width {Lambda}{sub t} is extracted from the partial decay width {Lambda}(t {yields} Wb) and the branching fraction {Beta}(t {yields} Wb). {Lambda}(t {yields} Wb) is obtained from the t-channel single top quark production cross section and {Beta}(t {yields} Wb) is measured in t{bar t} events. For a top mass of 172.5 GeV, the resulting width is {Lambda}{sub t} = 2.00{sub -0.43}{sup +0.47} GeV. This translates to a top-quark lifetime of {tau}{sub t} = (3.29{sub -0.63}{sup +0.90}) x 10{sup -25} s. We also extract an improved direct limit on the CKM matrix element 0.81 < |V{sub tb}| {le} 1 at 95% C.L. and a limit of |V{sub tb'}| < 0.59 for a high mass fourth generation bottom quark assuming unitarity of the fourth generation quark mixing matrix.

  17. Matching Derived Functionally-Same Stimulus Relations: Equivalence-Equivalence and Classical Analogies

    Science.gov (United States)

    Carpentier, Franck; Smeets, Paul M.; Barnes-Holmes, Dermot; Stewart, Ian

    2004-01-01

    Previous studies have shown that, after being trained on A-B and A-C matching tasks, subjects match not only functionally-same B and C stimuli (stimulus equivalence), but also BC compounds with same-class elements and BC compounds with different-class elements (equivalence-equivalence). Similar performances are required in classical analogies (a :…

  18. Overtraining increases the strength of equivalence relations

    Directory of Open Access Journals (Sweden)

    Renato Bortoloti

    2014-07-01

    Full Text Available 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 expressed 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-tosample tests.

  19. Overtraining increases the strength of equivalence relations

    Scientific Electronic Library Online (English)

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

    2013-12-01

    Full Text Available 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.

  20. FREQUENCY DEPENDENCE OF PULSE WIDTH FOR 150 RADIO NORMAL PULSARS

    Energy Technology Data Exchange (ETDEWEB)

    Chen, J. L. [Department of Physics and Electronic Engineering, Yuncheng University, 044000, Yuncheng, Shanxi (China); Wang, H. G., E-mail: hgwang.gz@gmail.com [Center for Astrophysics, Guangzhou University, 510006, Guangzhou (China)

    2014-11-01

    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 {sub 10} = A?{sup ?} + W {sub 10,} {sub min}. The relative fraction of pulse width change between 0.4 GHz and 4.85 GHz, ? = (W {sub 4.85} – W {sub 0.4})/W {sub 0.4}, is calculated in terms of the best-fit relationship for each pulsar. It is found that 81 pulsars (54%) have ? < –10% (group A), showing considerable profile narrowing at high frequencies, 40 pulsars (27%) have –10% ?? ? 10% (group B), meaning a marginal change in pulse width, and 29 pulsars (19%) 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.

  1. On the width of the full-critical region for thermal fluctuations around the superconducting transition in layered superconductors

    International Nuclear Information System (INIS)

    The crossover temperature between the mean-field and the full-critical regions for the thermal fluctuations around the superconducting transition is calculated for the first time in single-layered and bilayered (with two different distances and tunneling couplings between adjacent layers) superconductors at zero applied magnetic field. These results show, in particular, that the width of the full-critical region is somewhat smaller in layered superconductors than in equivalent bulk materials. These results are then discussed in connection with the superconducting transition of the high-Tc copper oxide superconductors. (orig.)

  2. Stimulus Equivalence: Testing Sidman's (2000) Theory

    OpenAIRE

    Minster, Sara Tepaeru; Jones, Max; Elliffe, Douglas; Muthukumaraswamy, Suresh D.

    2006-01-01

    Sidman's (2000) theory regarding the origin of equivalence relations predicts that a reinforcing stimulus common to distinct equivalence classes must drop out of the equivalence relations. This prediction was tested in the present study by arranging class-specific reinforcers, R1 and R2, following correct responding on the prerequisite conditional discriminations (Ax–Bx, Cx–Bx) for two stimulus classes, A1B1C1 and A2B2C2. A class-common reinforcer, R3, was presented following correct respondi...

  3. The equivalent ellipsoid of a magnetized body

    International Nuclear Information System (INIS)

    The equivalent ellipsoid for magnetized bodies of arbitrary shape can be determined by imposing the equality between the demagnetization factors of the two shapes of equal volume. It is shown that the 'commonsense' criterion for mapping two different shapes by imposing the equality of the demagnetization factors for equal aspect ratios often results in large errors. We propose a general method for the rigorous determination of the equivalent ellipsoid. The cases of the exact equivalent ellipsoids for discs, cylinders with elliptical cross section and prisms are worked out and discussed

  4. Thévenin equivalence in disorderless quantum networks

    International Nuclear Information System (INIS)

    We outline the procedure of extending the Thévenin equivalence principle for classical electric circuits to reducing Aharonov-Bohm-based quantum networks into equivalent models. With examples, we show from first principles how the requirements are related to the electron band structure's Fermi level and the lattice spacing of the network. Quantum networks of varying degrees of coupling strength from four basic classifications of single and double entangled loops sharing symmetry and highly correlated band structures are used to demonstrate the concept. We show the limitations of how the principle may be applied. Several classes of examples are given and their equivalent forms are shown

  5. On the off-diagonal operator equivalents

    International Nuclear Information System (INIS)

    A closed polynomial formula for the qth component of any off-diagonal operator equivalent of order k (integer or half-integer) is derived in terms of two-dimensional harmonic oscillator creation and annihilation operators. (Auth.)

  6. Agency Full Time Equivalency Reporting System

    Data.gov (United States)

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

  7. 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)

  8. Equivalence Principle, Higgs Boson and Cosmology

    Directory of Open Access Journals (Sweden)

    Mauro Francaviglia

    2013-05-01

    Full Text Available We discuss here possible tests for Palatini f(R-theories together with their implications for different formulations of the Equivalence Principle. We shall show that Palatini f(R-theories obey the Weak Equivalence Principle and violate the Strong Equivalence Principle. The violations of the Strong Equivalence Principle vanish in vacuum (and purely electromagnetic solutions as well as on short time scales with respect to the age of the universe. However, we suggest that a framework based on Palatini f(R-theories is more general than standard General Relativity (GR and it sheds light on the interpretation of data and results in a way which is more model independent than standard GR itself.

  9. Dosimetry with tissue equivalent plastic ionization chamber

    International Nuclear Information System (INIS)

    Tissue equivalent plastics have been widely used as the materials for radiation detectors and phantoms, and their muscle equivalency is reasonable for the radiation beam for radiotherapy. As the kerma factor for light elements is not known well above 30 MeV, it is desirable to make a tissue equivalent plastic, in which oxygen content is improved rather than that in present tissue equivalent plastics. One of the difficulties in the standardization of neutron dosimetry arised from that the different dosimetric constants have been used at respective institutions, and this is clear from the results of intercomparison of some neutron doses. The pair chamber method is valid for mixed fields, bacause neutron and ?-ray doses can be measured separately. However, the saturation characteristic of carbon chambers is very poor, therefore the correction factor must be determined experimentally for each individual ionization chamber. (Kobatake, H.)

  10. The Field Of Equivalent Some Numeral Methods

    Directory of Open Access Journals (Sweden)

    I. S. Kashirsky

    2008-05-01

    Full Text Available This paper describes some properties of methods for numeral solving partial differential equations. A number of identities are proved to show there are regions of equivalency for finite differences methods and finite elements Ritz-method.

  11. ICD-10 Oregon-Specific Equivalence Map

    Data.gov (United States)

    U.S. Department of Health & Human Services — DISCLAIMER: The Oregon-Specific Equivalence Map includes ICD-9 codes translated to ICD-10 based on a clinical and policy analysis of each code. It is not intended...

  12. Equivalence relations and the reinforcement contingency.

    Science.gov (United States)

    Sidman, M

    2000-07-01

    Where do equivalence relations come from? One possible answer is that they arise directly from the reinforcement contingency. That is to say, a reinforcement contingency produces two types of outcome: (a) 2-, 3-, 4-, 5-, or n-term units of analysis that are known, respectively, as operant reinforcement, simple discrimination, conditional discrimination, second-order conditional discrimination, and so on; and (b) equivalence relations that consist of ordered pairs of all positive elements that participate in the contingency. This conception of the origin of equivalence relations leads to a number of new and verifiable ways of conceptualizing equivalence relations and, more generally, the stimulus control of operant behavior. The theory is also capable of experimental disproof. PMID:10966100

  13. Interferometers: equivalent sine condition and pseudoholographic properties.

    Science.gov (United States)

    Simon, J M; Lemmi, C C

    1990-05-01

    We show experimentally how an interferometer, which in its current use does not have pseudoholographic properties, acquires them when the working conditions lead to the nonfulfillment of the equivalent sine condition. PMID:20563099

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

    Science.gov (United States)

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

    2015-10-01

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

  15. The principle of equivalence at finite temperature

    International Nuclear Information System (INIS)

    It is demonstrated that the equivalence principle is violated by radiative corrections to the gravitational and inertial masses at finite temperature. It is argued that this result can be attributed to the Lorentz noninvariance of the finite temperature vacuum. (author)

  16. Topological equivalence in families of complex polynomials

    CERN Document Server

    Bodin, A; Bodin, Arnaud; Tibar, Mihai

    2003-01-01

    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\

  17. Quantum equivalence principle without mass superselection

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-11-08

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

  18. The first spectra for the RX J0440.9+4431 from 2m Terskol telescope

    OpenAIRE

    Simon, Andrew; Bondar, A. V.; Reshetnyk, V. M.

    2012-01-01

    We present the first results on the spectra of Be/X-ray binary RX J0440.9+4431 obtained with the 2m Ritchey-Cretein-Coude telescope with Cassegrain Multi Mode Spectrograph (CMMS) (with R = 14000) at Terskol observatory. The H-alpha line profile indicates that the new episode of the V/R variability is occuring in the system. The profiles of the H-alpha, H-beta and HeI 7065.71, 6678.15, 5875.97 lines were analyzed and equivalent width were determined. We compared our H-alpha line profile parame...

  19. Dark matter and the equivalence principle

    Science.gov (United States)

    Frieman, Joshua A.; Gradwohl, Ben-Ami

    1993-01-01

    A survey is presented of the current understanding of dark matter invoked by astrophysical theory and cosmology. Einstein's equivalence principle asserts that local measurements cannot distinguish a system at rest in a gravitational field from one that is in uniform acceleration in empty space. Recent test-methods for the equivalence principle are presently discussed as bases for testing of dark matter scenarios involving the long-range forces between either baryonic or nonbaryonic dark matter and ordinary matter.

  20. Refining the Proof of Planar Equivalence

    CERN Document Server

    Armoni, A; Veneziano, Gabriele

    2005-01-01

    We outline a full non-perturbative proof of planar (large-N) equivalence between bosonic correlators in a theory with Majorana fermions in the adjoint representation and one with Dirac fermions in the two-index (anti)symmetric representation. In a particular case (one flavor), this reduces to our previous result - planar equivalence between super-Yang--Mills theory and a non-supersymmetric ``orientifold field theory.'' The latter theory becomes one-flavor massless QCD at N=3.

  1. Equivalence relations and the reinforcement contingency.

    OpenAIRE

    Sidman, M

    2000-01-01

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

  2. Bisimulations Meet PCTL Equivalences for Probabilistic Automata

    DEFF Research Database (Denmark)

    Song, Lei; Zhang, Lijun; Godskesen, Jens Chr.

    2011-01-01

    Probabilistic automata (PA) [20] 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 [11] and its extension PCTL? [4]. 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 str...

  3. GIT-equivalence beyond the ample cone

    OpenAIRE

    Berchtold, Florian; Hausen, Juergen

    2005-01-01

    Given an algebraic torus action on a normal projective variety with finitely generated total coordinate ring, we study the GIT-equivalence for not necessarily ample linearized divisors, and we provide a combinatorial description of the partially ordered set of GIT-equivalence classes. As an application, we extend in the $\\QQ$-factorial case a basic feature of the collection of ample GIT-classes to the partially ordered collection of maximal subsets with a quasiprojective quo...

  4. Personnel monitors utilizing tissue equivalent proportional counters

    International Nuclear Information System (INIS)

    The U.S. Department of Energy has established a program to improve neutron dosimetry at facilities where a significant number of workers are exposed to fast neutrons from handling isotopic neutron sources. One facet of this program is the development of small, lightweight personnel monitors to determine dose equivalent as the workers are exposed. These instruments use small cylindrical tissue equivalent proportional counters to detect neutrons, and a microprocessor to determine absorbed dose and dose equivalent. A Pocket REM Meter containing three cylindrical tissue equivalent proportional counters 1.9-cm in diameter and 13-cm long is developed. The instrument utilizes hybrid circuitry and a 256 channel analog to digital converter to supply signals to a CMOS microprocessor, which calculates absorbed dose and dose equivalent for neutrons and displays the results on a liquid crystal display. Independent measurements at the Pacific Northwest Laboratory verified that the Pocket REM Meter is accurate within 20% for determining neutron dose equivalent when exposed to unmoderated or slightly moderated Cf-252 sources, which have been calibrated by the U.S. National Bureau of Standards. The Laboratory is developing a Total Dose Meter to measure absorbed dose and determine dose equivalent from mixed radiation fields of neutrons and gamma rays. Using a single tissue equivalent proportional counter with two amplifiers operated at different gains. Using empirical algorithms derived from exposures to monoenergetic neutrons, it is possible to determine quality factors within about 7% for neutrons with energies between 200 KeV and 7.5 MeV

  5. The endotopism semigroups of an equivalence relation

    Energy Technology Data Exchange (ETDEWEB)

    Zhuchok, Yu V [National Taras Shevchenko University of Kiev (Ukraine); Toichkina, E A [Lugansk Taras Shevchenko National University, Lugansk (Ukraine)

    2014-05-31

    In this work we investigate six types of endotopism semigroups for a given equivalence relation. Necessary and sufficient conditions for the existence of all such endotopisms are presented. Conditions for the regularity and coregularity of each of the endotopism semigroups of a given type are established. The notion of the endotype of a binary relation with respect to its endotopisms is introduced and the endotype of an arbitrary equivalence relation is calculated. Bibliography: 26 titles.

  6. Fucoidan Promotes the Reconstruction of Skin Equivalents

    OpenAIRE

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

    2014-01-01

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

  7. Equivalent Scale on Food Consumption in Turkey

    OpenAIRE

    Haydar Sengul

    2006-01-01

    This study investigates effect of household composition and size on food consumption in the rural and urban areas of Turkey through equivalence scales that vary by household member age. Food consumption studies on Turkey have tended to ignore the impact of household composition in consumption traditionally analyses of food consumption are conducted on a per capita basis. Equivalence scales were estimated by Engel method using Household Consumption Expenditure Survey (HCES) data of the State I...

  8. Mimicking Meaningfulness:stimulus equivalence and meaning

    OpenAIRE

    Nartey, Richard Korley

    2010-01-01

    The current paper reflects on some of the basic issues in the concept of stimulus equivalence as proposed by Murray Sidman. The paired-associate paradigm was the predominant method being employed to demonstrate how organisms come to treat dissimilar events that had not been related before as if they were the same. Several papers by Murray Sidman after the demise of the pair-associates methodology brought a paradigm shift in stimulus equivalence research from the paired-associates realm to the...

  9. The nonequivalence of behavioral and mathematical equivalence.

    OpenAIRE

    Saunders, R. R.; Green, G

    1992-01-01

    Sidman and his colleagues derived behavioral tests for stimulus equivalence from the axiom in logic and mathematics that defines a relation of equivalence. The analogy has generated abundant research in which match-to-sample methods have been used almost exclusively to study interesting and complex stimulus control phenomena. It has also stimulated considerable discussion regarding interpretation of the analogy and speculation as to its validity and generality. This article reexamines the Sid...

  10. Quantitative and methodological aspects of stimulus equivalence

    OpenAIRE

    O'Mara, Henry

    1991-01-01

    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...

  11. Income Dependent Equivalence Scales, Inequality, and Poverty

    OpenAIRE

    Dudel, Christian; Garbuszus, Jan Marvin; Ott, Notburga; Werding, Martin

    2015-01-01

    Most equivalence scales which are applied in research on poverty and inequality do not depend on income, although there is strong empirical evidence that equivalence scales in fact are income dependent. This paper explores the consistency of results derived from income independent and income dependent scales. It is shown that scales of both types inevitably lead to differing assessments of poverty and inequality under quite general conditions. German microdata will be used to demonstrate and ...

  12. Fiscal adjustments in Europe and Ricardian equivalence

    OpenAIRE

    V. DE BONIS; Paladini, R.

    1998-01-01

    According to the ‘Ricardian’ equivalence hypothesis, consumption is dependent on permanent disposable income and current deficits are equivalent to future tax payments. This hypothesis is tested on 14 European countries in the 1990s. The relationships between private sector savings and general government deficit, and the GDP growth rate and the unemployment rate are determined. The results show the change in consumers' behaviour with respect to government deficit, and that expectations of an ...

  13. 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)

  14. Stark widths and oscillator strengths of Xe III lines

    International Nuclear Information System (INIS)

    In order to test the reliability of the configuration interaction (CI) method to predict the atomic parameters viz oscillator strengths of complex ions, we measured the profiles of forty (40) strong 6s-6p transitions of Xe III emitted by a pulsed capillary discharge. After deconvoluting the experimental shapes, Stark widths and relative oscillator strengths were obtained. When least square fitted (LSF) parameters were used in addition to extensive CI (CI + LSF), the agreement between theory and experiment for the gf's is within a factor two for the whole of the lines. Concerning the widths, the semiempirical approach provides values also within a factor two when the Gaunt factor is taken to be g(x) ? 0.30. (orig.)

  15. The Definition of Mass and Width of Relativistic Resonances

    International Nuclear Information System (INIS)

    For relativistic resonances, the lineshape alone does not uniquely determine the resonance parameters, namely the mass (M) and width (?). A unique definition of the resonance parameters is given if one uses a broader theory of quasistable particles, i.e. which unifies resonances and decaying states. The theory of quasistable particles is developed in analogy to that of stable particles: Wigner's Unitary Irreducible representations of the Poincare group characterize stable particles by mass (M) and spin (j), whereas quasistable particles will be characterized by mass squared sR = (MR - i?R/2) and spin (j). It follows that the resonance width ?R is related to the lifetime of the state by ?R = 1/?. The Z-boson is used as an example

  16. Direct Measurement Of W Boson Decay Width At Do

    CERN Document Server

    Xu, Q

    2001-01-01

    This thesis presents the first direct measurement of the W boson decay width, ?W, with the W decay into an electron and neutrino final state using data collected by the DØ detector at the Tevatran collider. This analysis has used the W event sample collected in the Run I physics program. Backgrounds that contaminate the W sample are estimated using additional DØ data samples. Detailed Monte Carlo samples are used to template the transverse mass spectrum of the W events to extract the W decay width. Various sources of the systematic uncertainties of this measurement are investigated. The direct measurement result obtained in this thesis work is ?W = 2.231+0.145?0.138(stat) ± 0.092(sys) GeV. This result is consistent with the prediction of the Standard Model and the result from the indirect measurement from the DØ experiment.

  17. Determination of the width of the top quark.

    Science.gov (United States)

    Abazov, V M; Abbott, B; Abolins, M; Acharya, B S; Adams, M; Adams, T; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Ancu, L S; Aoki, M; Arnoud, Y; Arov, M; Askew, A; Åsman, B; Atramentov, O; Avila, C; BackusMayes, J; Badaud, F; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, S; Barberis, E; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bazterra, V; Beale, S; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; 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; Brandt, O; Brock, R; Brooijmans, G; Bross, A; Brown, D; Brown, J; Bu, X B; Buchholz, D; Buehler, M; Buescher, V; Bunichev, V; Burdin, S; Burnett, T H; Buszello, C P; Calpas, B; Camacho-Pérez, E; Carrasco-Lizarraga, M A; Casey, B C K; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chandra, A; Chen, G; Chevalier-Théry, S; Cho, D K; Cho, S W; Choi, S; Choudhary, B; Christoudias, T; Cihangir, S; Claes, D; Clutter, J; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M-C; Croc, A; Cutts, D; Ćwiok, M; Das, A; Davies, G; De, K; de Jong, S J; De la Cruz-Burelo, E; Déliot, F; Demarteau, M; Demina, R; Denisov, D; Denisov, S P; Desai, S; DeVaughan, K; Diehl, H T; Diesburg, M; Dominguez, A; Dorland, T; Dubey, A; Dudko, L V; Duggan, D; Duperrin, A; Dutt, S; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Eno, S; Evans, H; Evdokimov, A; Evdokimov, V N; Facini, G; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fortner, M; Fox, H; Fuess, S; Gadfort, T; Garcia-Bellido, A; Gavrilov, V; Gay, P; Geist, W; Geng, W; Gerbaudo, D; Gerber, C E; Gershtein, Y; Ginther, G; Golovanov, G; Goussiou, A; Grannis, P D; Greder, S; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, Ph; Grivaz, J-F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guo, F; Guo, J; Gutierrez, G; Gutierrez, P; Haas, A; Hagopian, S; Haley, J; Han, L; Harder, K; Harel, A; Hauptman, J M; Hays, J; Head, T; Hebbeker, T; Hedin, D; Hegab, H; Heinson, A P; Heintz, U; Hensel, C; Heredia-De la Cruz, I; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hoang, T; Hobbs, J D; Hoeneisen, B; Hohlfeld, M; Hossain, S; Hubacek, Z; Huske, N; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jamin, D; Jesik, R; Johns, K; Johnson, M; Johnston, D; Jonckheere, A; Jonsson, P; Joshi, J; 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; Khatidze, D; Kirby, M H; Kohli, J M; Kozelov, A V; Kraus, J; Kumar, A; Kupco, A; Kurča, T; Kuzmin, V A; Kvita, J; Lammers, S; Landsberg, G; Lebrun, P; Lee, H S; Lee, S W; Lee, W M; Lellouch, J; Li, L; Li, Q Z; Lietti, S M; Lim, J K; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Y; Liu, Z; Lobodenko, A; Lokajicek, M; Love, P; Lubatti, H J; Luna-Garcia, R; Lyon, A L; Maciel, A K A; Mackin, D; Madar, R; Magaña-Villalba, R; Malik, S; Malyshev, V L; Maravin, Y; Martínez-Ortega, J; McCarthy, R; McGivern, C L; Meijer, M M; Melnitchouk, A; Menezes, D; Mercadante, P G; Merkin, M; Meyer, A; Meyer, J; Mondal, N K; Muanza, G S; Mulhearn, M; Nagy, E; Naimuddin, M; Narain, M; Nayyar, R; Neal, H A; Negret, J P; Neustroev, P; Novaes, S F; Nunnemann, T; Obrant, G; Orduna, J; Osman, N; Osta, J; Otero y Garzón, G J; Owen, M; Padilla, M; Pangilinan, M; Parashar, N; Parihar, V; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Penning, B; Perfilov, M; Peters, K; Peters, Y; Petrillo, G; Pétroff, P; Piegaia, R; Piper, J; Pleier, M-A; Podesta-Lerma, P L M; Podstavkov, V M; Pol, M-E; Polozov, P; Popov, A V; Prewitt, M; Price, D; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rangel, M S; Ranjan, K; Ratoff, P N; Razumov, I; Renkel, P; Rich, P; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Rominsky, M; Royon, C; Rubinov, P; Ruchti, R; Safronov, G; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Sanghi, B; Santos, A S; Savage, G; Sawyer, L; Scanlon, T; Schamberger, R D; Scheglov, Y; Schellman, H; Schliephake, T; Schlobohm, S; Schwanenberger, C; Schwienhorst, R; Sekaric, J; Severini, H; Shabalina, E; Shary, V; Shchukin, A A; Shivpuri, R K; Simak, V; Sirotenko, V; Skubic, P; Slattery, P; Smirnov, D; Smith, K J; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Sonnenschein, L; Sopczak, A; Sosebee, M; Soustruznik, K; Spurlock, B; Stark, J; Stolin, V; Stoyanova, D A; Strauss, E; Strauss, M; Strom, D; Stutte, L; Svoisky, P; Takahashi, M; Tanasijczuk, A; Taylor, W; Titov, M; Tokmenin, V V; Tsybychev, D; Tuchming, B; Tully, C; Tuts, P M; Uvarov, L; Uvarov, S; Uzunyan, S; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vasilyev, I A; Verdier, P; Vertogradov, L S; Verzocchi, M; Vesterinen, M; Vilanova, D; Vint, P; Vokac, P; Wahl, H D; Wang, M H L S; Warchol, J; Watts, G; Wayne, M; Weber, M; Welty-Rieger, L; Wetstein, M; White, A; Wicke, D; Williams, M R J; Wilson, G W; Wimpenny, S J; Wobisch, M; Wood, D R; Wyatt, T R; Xie, Y; Xu, C; Yacoob, S; Yamada, R; Yang, W-C; Yasuda, T; Yatsunenko, Y A; Ye, Z; Yin, H; Yip, K; Yoo, H D; Youn, S W; Yu, J; Zelitch, S; Zhao, T; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zivkovic, L

    2011-01-14

    We extract the total width of the top quark, Γ(t), from the partial decay width Γ(t → Wb) measured using the t-channel cross section for single top-quark production and from the branching fraction B(t → Wb) measured in tt events using up to 2.3  fb(-1) of integrated luminosity collected by the D0 Collaboration at the Tevatron pp Collider. The result is Γ(t) = 1.99(-0.55)(+0.69)  GeV, which translates to a top-quark lifetime of τ(t) = (3.3(-0.9)(+1.3)) × 10(-25)   s. Assuming a high mass fourth generation b' quark and unitarity of the four-generation quark-mixing matrix, we set the first upper limit on |V(tb')| < 0.63 at 95% C.L. PMID:21405220

  18. Determination of total and partial widths of unbound states

    International Nuclear Information System (INIS)

    Observations of the ?-ray decay between unbound states and the subsequent decay of the lower state have enabled the determination of the relative proton and ?-radiation widths of the lower state. These measurements together with a determination of the resonance strength of the lower state make it possible, in some cases, to deduce the total and all partial decay widths of this state. These measurements are clearly restricted in application to nuclei with low lying states which are unbound against proton decay. Nevertheless there are several nuclei in particular those with 2n neutrons and 2n+1 protons for which useful information can be extracted by this method. Applications of this method to states in the nuclei 59Cu, 41Sc and 29P are discussed

  19. Spectral properties and dynamical tunneling in constant-width billiards.

    Science.gov (United States)

    Dietz, B; Guhr, T; Gutkin, B; Miski-Oglu, M; Richter, A

    2014-08-01

    We determine with unprecedented accuracy the lowest 900 eigenvalues of two quantum constant-width billiards from resonance spectra measured with flat, superconducting microwave resonators. While the classical dynamics of the constant-width billiards is unidirectional, a change of the direction of motion is possible in the corresponding quantum system via dynamical tunneling. This becomes manifest in a splitting of the vast majority of resonances into doublets of nearly degenerate ones. The fluctuation properties of the two respective spectra are demonstrated to coincide with those of a random-matrix model for systems with violated time-reversal invariance and a mixed dynamics. Furthermore, we investigate tunneling in terms of the splittings of the doublet partners. On the basis of the random-matrix model we derive an analytical expression for the splitting distribution which is generally applicable to systems exhibiting dynamical tunneling between two regions with (predominantly) chaotic dynamics. PMID:25215795

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-07-01

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