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Sample records for lmc rr lyrae

  1. Analysis of a selected sample of RR Lyrae stars in the LMC from OGLE-III

    International Nuclear Information System (INIS)

    Chen Bing-Qiu; Jiang Bi-Wei; Yang Ming

    2013-01-01

    A systematic study of RR Lyrae stars is performed using a selected sample of 655 objects in the Large Magellanic Cloud (LMC) with long-term observations and numerous measurements from the Optical Gravitational Lensing Experiment III project. The phase dispersion method and linear superposition of the harmonic oscillations are used to derive the pulsation frequency and properties of light variation. It is found that a dichotomy exists in Oosterhoff Type I and Oosterhoff Type II for RR Lyrae stars in the LMC. Due to our strict criteria for identifying a frequency, a lower limit for the incidence rate of Blazhko modulation in the LMC is estimated in various subclasses of RR Lyrae stars. For fundamental-mode RR Lyrae stars, the rate of 7.5% is smaller than the previous result. In the case of the first-overtone RR Lyrae variables, the rate of 9.1% is relatively high. In addition to the Blazhko variables, 15 objects are identified to pulsate in the fundamental/first-overtone double mode. Furthermore, four objects show a period ratio around 0.6, which makes them very likely to be rare pulsators in the fundamental/second-overtone double mode. (research papers)

  2. NONLINEAR ASTEROSEISMOLOGY OF RR LYRAE

    Energy Technology Data Exchange (ETDEWEB)

    Molnar, L.; Kollath, Z.; Szabo, R. [Konkoly Observatory, MTA CSFK, H-1121 Budapest, Konkoly Thege Miklos ut 15-17 (Hungary); Bryson, S.; Mullally, F.; Thompson, S. E. [NASA Ames Research Center, MS 244-30, Moffet Field, CA 94035 (United States); Kolenberg, K., E-mail: molnar.laszlo@csfk.mta.hu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge MA 02138 (United States)

    2012-09-20

    The observations of the Kepler Space Telescope revealed that fundamental-mode RR Lyrae stars may show various radial overtones. The presence of multiple radial modes may allow us to conduct nonlinear asteroseismology: comparison of mode amplitudes and frequency shifts between observations and models. Here we report the detection of three radial modes in the star RR Lyr, the eponym of the class, using the Kepler short cadence data: besides the fundamental mode, both the first and the ninth overtones can be derived from the data set. RR Lyrae shows period doubling, but switches occasionally to a state where a pattern of six pulsation cycles repeats instead of two. We found hydrodynamic models that show the same three modes and the period-six state, allowing for comparison with the observations.

  3. Exploring M33 Through RR Lyrae Stars

    OpenAIRE

    Pritzl, Barton J.

    2013-01-01

    Recent surveys have detected RR Lyrae stars in M33, the Triangulum Galaxy. These variable stars are excellent tracers of ancient stellar populations. The RR Lyrae stars have been used to estimate metallicities at various locations within M33, as well as determining the distance to the galaxy. A summary of the M33 RR Lyrae stars is presented here as well as an analysis on what their properties imply for the unique M33 galaxy

  4. RR Lyrae Stars in M4

    Science.gov (United States)

    Kuehn, Charles A.; Moskalik, Pawel; Drury, Jason A.

    2017-10-01

    Observations by Kepler/K2 have revolutionized the study of RR Lyrae stars by allowing the detection of new phenomna, such as low amplitude additional modes and period doubling, which had not previously been seen from the ground. During campaign 2, K2 observed the globular cluster M4, providiing the first opportunity to study a sizeable group of RR Lyrae stars that belong to a single population; the other RR Lyrae stars that have been observed from space are field stars in the galactic halo and thus belong to an assortment of populations. In this poster we present the results of our study of the RR Lyrae variables in M4 from K2 photometry. We have identified additional, low amplitude pulsation modes in both observed RRc stars. In 3 RRab stars we have found the Blazhko effect with periods of 16.6d, 22.4d, and 44.5d.

  5. RR Lyrae Stars in M4

    Directory of Open Access Journals (Sweden)

    Kuehn Charles A

    2017-01-01

    Full Text Available Observations by Kepler/K2 have revolutionized the study of RR Lyrae stars by allowing the detection of new phenomna, such as low amplitude additional modes and period doubling, which had not previously been seen from the ground. During campaign 2, K2 observed the globular cluster M4, providiing the first opportunity to study a sizeable group of RR Lyrae stars that belong to a single population; the other RR Lyrae stars that have been observed from space are field stars in the galactic halo and thus belong to an assortment of populations. In this poster we present the results of our study of the RR Lyrae variables in M4 from K2 photometry. We have identified additional, low amplitude pulsation modes in both observed RRc stars. In 3 RRab stars we have found the Blazhko effect with periods of 16.6d, 22.4d, and 44.5d.

  6. First Kepler Results on RR Lyrae Stars

    DEFF Research Database (Denmark)

    Kolenberg, K.; Szabó, R.; Kurtz, D. W.

    2010-01-01

    We present the first results of our analyses of selected RR Lyrae stars for which data have been obtained by the Kepler Mission. As expected, we find a significant fraction of the RRab stars to show the Blazhko effect, a still unexplained phenomenon that manifests itself as periodic amplitude and...

  7. Radial velocities of RR Lyrae stars

    International Nuclear Information System (INIS)

    Hawley, S.L.; Barnes, T.G. III

    1985-01-01

    283 spectra of 57 RR Lyrae stars have been obtained using the 2.1-m telescope at McDonald Observatory. Radial velocities were determined using a software cross-correlation technique. New mean radial velocities were determined for 46 of the stars. 11 references

  8. RR Lyrae star distance scale and kinematics from inner bulge to 50 kpc

    Directory of Open Access Journals (Sweden)

    Dambis Andrei

    2017-01-01

    Full Text Available We use the currently most complete sample of ∼ 3500 type ab RR Lyraes in our Galaxy with available radial-velocity and [Fe/H] measurements to perform a statisticalparallax analysis for a subsample of ∼ 600 type ab RR Lyraes located within 5 kpc from the Sun to refine the parameters of optical and WISE W1-band period-metallicityluminosity relations and adjust our preliminary distances. The new zero point implies the rescaled estimates for the solar Galactocentric distance (RG = 7.99 ± 0.37 kpc and the LMC distance modulus (DMLMC = 18.39 ±0.09. We use the kinematic data for the entire sample to explore the dependence of the halo and thick-disk RR Lyrae velocity ellipsoids on Galactocentric distance from the inner bulge out to R ∼ 50 kpc.

  9. Nonlinear Convective Models of RR Lyrae Stars

    Science.gov (United States)

    Feuchtinger, M.; Dorfi, E. A.

    The nonlinear behavior of RR Lyrae pulsations is investigated using a state-of-the-art numerical technique solving the full time-dependent system of radiation hydrodynamics. Grey radiative transfer is included by a variable Eddington-factor method and we use the time-dependent turbulent convection model according to Kuhfuss (1986, A&A 160, 116) in the version of Wuchterl (1995, Comp. Phys. Comm. 89, 19). OPAL opacities extended by the Alexander molecule opacities at temperatures below 6000 K and an equation of state according to Wuchterl (1990, A&A 238, 83) close the system. The resulting nonlinear system is discretized on an adaptive mesh developed by Dorfi & Drury (1987, J. Comp. Phys. 69, 175), which is important to provide the necessary spatial resolution in critical regions like ionization zones and shock waves. Additionally, we employ a second order advection scheme, a time centered temporal discretizaton and an artificial tensor viscosity in order to treat discontinuities. We compute fundamental as well first overtone models of RR Lyrae stars for a grid of stellar parameters both with and without convective energy transport in order to give a detailed picture of the pulsation-convection interaction. In order to investigate the influence of the different features of the convection model calculations with and without overshooting, turbulent pressure and turbulent viscosity are performed and compared with each other. A standard Fourier decomposition is used to confront the resulting light and radial velocity variations with recent observations and we show that the well known RR Lyrae phase discrepancy problem (Simon 1985, ApJ 299, 723) can be resolved with these stellar pulsation computations.

  10. Studying RR Lyrae Stars in M4 with K2

    Science.gov (United States)

    Kuehn, Charles A.; Drury, Jason; Moskalik, Pawel

    2017-01-01

    Observations by Kepler/K2 have revolutionized the study of RR Lyrae stars by allowing the detection of new phenomena, such as low amplitude additional modes and period doubling, which had not previously been seen from the ground. During its campaign 2, K2 observed the globular cluster M4, providing the first opportunity to study a sizeable group of RR Lyrae stars that belong to a single population; the other RR Lyrae stars that have been observed from space are field stars in the galactic halo and thus belong to an assortment of populations. We present the results of our study of the RR Lyrae variables in M4 from K2 photometry. We have identified additional, low amplitude pulsation modes in the two observed RRc stars. In three RRab stars we have found the Blazhko effect with periods of 16.6 days, 22.4 days, and 44.5 days.

  11. Contamination of RR Lyrae stars from Binary Evolution Pulsators

    Science.gov (United States)

    Karczmarek, Paulina; Pietrzyński, Grzegorz; Belczyński, Krzysztof; Stępień, Kazimierz; Wiktorowicz, Grzegorz; Iłkiewicz, Krystian

    2016-06-01

    Binary Evolution Pulsator (BEP) is an extremely low-mass member of a binary system, which pulsates as a result of a former mass transfer to its companion. BEP mimics RR Lyrae-type pulsations but has different internal structure and evolution history. We present possible evolution channels to produce BEPs, and evaluate the contamination value, i.e. how many objects classified as RR Lyrae stars can be undetected BEPs. In this analysis we use population synthesis code StarTrack.

  12. La Silla quest RR Lyrae star survey: Region I

    International Nuclear Information System (INIS)

    Zinn, R.; Miller, L.; Horowitz, B.; Baltay, C.; Ellman, N.; Hadjiyska, E.; Rabinowitz, D.; Vivas, A. K.

    2014-01-01

    A search for RR Lyrae stars (RRLSs) in ∼840 deg 2 of the sky in right ascension 150°-210° and declination –10° to + 10° yielded 1013 type ab and 359 type c RRLS. This sample is used to study the density profile of the Galactic halo, halo substructures, and the Oosterhoff type of the halo over distances (d ☉ ) from ∼5 to ∼80 kpc. The halo is flattened toward the Galactic plane, and its density profile steepens in slope at galactocentric distances greater than ∼25 kpc. The RRLS in the stellar stream from the Sagittarius dwarf spheroidal (dSph) galaxy match well the model of Law and Majewski for the stars that were stripped 1.3-3.2 Gyr ago, but not for the ones stripped 3.2-5.0 Gyr ago. Over densities are found at the locations of the Virgo Overdensity and the Virgo Stellar Stream. Within 1° of 1220-1, which Jerjen et al. identify as a halo substructure at d ☉ ∼ 24 kpc, there are four RRLS that are possibly members. Away from substructures, the RRLS are a mixture of Oosterhoff types I and II, but mostly OoI (∼73%). The accretion of galaxies resembling in RRLS content the most massive Milky Way satellites (LMC, SMC, For, Sgr) may explain this preponderance of OoI. Six new RRLS and three new anomalous Cepheids were found in the Sextans dSph galaxy.

  13. RR Lyrae and BL Herculis variables

    International Nuclear Information System (INIS)

    Cox, A.N.

    1980-01-01

    The RR Lyrae variables are currently believed to have masses between about 0.5 and 0.8 M/sub solar mass/, effective surface temperatures between 6350 and 7500 0 K, radii from about 4.0 to 6.0 R/sub solar mass/ and luminosities between log L/L/sub solar mass/ of 1.5 and 2.0. Since they are found in population II locations, they generally have Y = 0.3 and Z = 10 -3 , but there are exceptions for both higher Z like the sun and lower Z like 0.0002. In globular clusters the periods range from 0.25 to 0.45 day for the first overtone pulsators and 0.40 to 0.80 day for those in the fundamental mode, depending on their luminosity. At transition lines, discussed in detail, the switch from fundamental to first overtone, or maybe vice versa, involves a period change factor of about 0.74 to 0.75

  14. Gauging the Galactic thick disk with RR Lyrae stars

    Directory of Open Access Journals (Sweden)

    Cruz G.

    2012-02-01

    Full Text Available In this contribution we present results from the QUEST RR Lyrae Survey of the thick disk. The survey spans ~480 sq. deg. at low latitude |b| < 30°, with multi-epoch VRI observations, obtained with the QUEST-I camera at the 1m Jürgen Stock Schmidt telescope located at the National Astronomical Observatory of Venezuela. This constitutes the first deep RR Lyrae survey of the Galactic thick disk conducted at low galactic latitudes, covering simultaneously a large range in radial (8RR Lyrae stars having accurate distances (errors <7% and individual reddenings derived from each star’s color curve at minimum light. Moreover, the use of RR Lyrae stars as tracers ensures negligible contamination from the Galactic thin disk. We find a thick disk mean scale height hZ = 0.94 ± 0.11kpc and scale length hR = 3.2 ± 0.4kpc, derived from the vertical and radial mean density profiles of RR Lyrae stars. We also find evidence of thick disk flaring and results that may suggest the thick disk radial density profile shows signs of antitruncation. We discuss our findings in the context of recent thick disk formation models.

  15. RR lyrae variable pulsations and the Oosterhoff groups

    International Nuclear Information System (INIS)

    Cox, A.N.

    1981-01-01

    It is concluded that Oosterhoff group I clusters have 0.55 M/sub sun/ stars and group II clusters have 0.65 M/sub sun/ stars. The Y value is always about 0.29. Mean log L/L/sub sun/ values are 1.66 and 1.78 giving M/sub bol/ = 0.60 and 0.30 for the RR Lyrae variables in these two groups of clusters. For field RR Lyrae variables at M = approx. 0.5 M/sub sun/ or less, perhaps M/sub bol/ = 0.90 or even larger as Clube and Jones propose. Apparently all evolution is blueward for RR Lyrae variables, and the color overlap of F and 1H pulsators is not real

  16. The globular cluster ω Centauri and its RR Lyrae variables

    International Nuclear Information System (INIS)

    Dickens, R.J.

    1989-07-01

    The significance of some of the unusual characteristics of the globular cluster ωCentauri in various fundamental problems is explored. Interest is centred on the properties of the cluster RR Lyraes, and what they can contribute to studies of early cluster chemical enrichment, stellar pulsation, the distance scale, stellar evolution, stellar ages and the Oosterhoff period-shift problem. This article, which is intended to highlight problems and progress rather than give a comprehensive review, includes new results based on photometry of the RR Lyraes, red giants, subgiants, horizontal-branch and main sequence stars in the cluster. (author)

  17. Period Changes of 23 Field RR Lyrae Stars

    Directory of Open Access Journals (Sweden)

    Soo-Chang Rey

    1994-12-01

    Full Text Available The secular period behavior of 23 field RR Lyrae stars is studied in order to determine if the observed period changes could be attributed, at least in the mean, to stellar evolution. The sample of stars is subdivided into two Oosterhoff groups based on the metallicity and period-shift. Despite the small sample size, we found a distinct bias toward positive period changes in the group variables. The period changes of the group variables in globular clusters. This provides yet another support for the Lee, Demarque, and Zinn(1990 evolutionary models of RR Lyrae stars and their explanation of the Sandage period-shift effect.

  18. La Silla quest RR Lyrae star survey: Region I

    Energy Technology Data Exchange (ETDEWEB)

    Zinn, R.; Miller, L. [Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520-8101 (United States); Horowitz, B.; Baltay, C.; Ellman, N.; Hadjiyska, E.; Rabinowitz, D. [Department of Physics, Yale University, P.O. Box 208120, New Haven, CT 06511-8499 (United States); Vivas, A. K. [Centro de Investigaciones de Astronomía, Apartado Postal 264, Mérida 5101-A (Venezuela, Bolivarian Republic of)

    2014-01-20

    A search for RR Lyrae stars (RRLSs) in ∼840 deg{sup 2} of the sky in right ascension 150°-210° and declination –10° to + 10° yielded 1013 type ab and 359 type c RRLS. This sample is used to study the density profile of the Galactic halo, halo substructures, and the Oosterhoff type of the halo over distances (d {sub ☉}) from ∼5 to ∼80 kpc. The halo is flattened toward the Galactic plane, and its density profile steepens in slope at galactocentric distances greater than ∼25 kpc. The RRLS in the stellar stream from the Sagittarius dwarf spheroidal (dSph) galaxy match well the model of Law and Majewski for the stars that were stripped 1.3-3.2 Gyr ago, but not for the ones stripped 3.2-5.0 Gyr ago. Over densities are found at the locations of the Virgo Overdensity and the Virgo Stellar Stream. Within 1° of 1220-1, which Jerjen et al. identify as a halo substructure at d {sub ☉} ∼ 24 kpc, there are four RRLS that are possibly members. Away from substructures, the RRLS are a mixture of Oosterhoff types I and II, but mostly OoI (∼73%). The accretion of galaxies resembling in RRLS content the most massive Milky Way satellites (LMC, SMC, For, Sgr) may explain this preponderance of OoI. Six new RRLS and three new anomalous Cepheids were found in the Sextans dSph galaxy.

  19. RR LYRAE ATMOSPHERICS: WRINKLES OLD AND NEW. A PREVIEW

    International Nuclear Information System (INIS)

    Preston, George W.

    2011-01-01

    I report some results of an echelle spectroscopic survey of RR Lyrae stars begun in 2006 that I presented in my Henry Norris Lecture of 2010 January 4. Topics include (1) atmospheric velocity gradients, (2) phase-dependent envelope turbulence as it relates to Peterson's discoveries of axial rotation on the horizontal branch and to Stothers' explanation of the Blazhko effect, (3) the three apparitions of hydrogen emission during a pulsation cycle, (4) the occurrence of He I lines in emission and absorption, (5) detection of He II emission and metallic line doubling in Blazhko stars, and finally (6) speculation about what helium observations of RR Lyrae stars in omega Centauri might tell us about the putative helium populations and the horizontal branch of that strange globular cluster.

  20. Measurement and theory of turbulence in RR Lyrae

    International Nuclear Information System (INIS)

    Benz, W.; Stellingwerf, R.F.

    1985-01-01

    CORAVEL observations of time-dependent turbulence in RR Lyrae are presented. Variation in the width of the mean velocity correlation function implies turbulent velocities that peak at 10 to 15 km/sec for a brief interval of phase near minimum radius. Comparison with a nonlinear pulsation model shows that these amplitudes of the turbulent velocity are expected near the hydrogen ionization zone, again only near minimum radius

  1. Unmixing the Galactic halo with RR Lyrae tagging

    Science.gov (United States)

    Belokurov, V.; Deason, A. J.; Koposov, S. E.; Catelan, M.; Erkal, D.; Drake, A. J.; Evans, N. W.

    2018-06-01

    We show that tagging RR Lyrae stars according to their location in the period-amplitude diagram can be used to shed light on the genesis of the Galactic stellar halo. The mixture of RR Lyrae of ab type, separated into classes along the lines suggested by Oosterhoff, displays a strong and coherent evolution with Galactocentric radius. The change in the RR Lyrae composition appears to coincide with the break in the halo's radial density profile at ˜25 kpc. Using simple models of the stellar halo, we establish that at least three different types of accretion events are necessary to explain the observed RRab behaviour. Given that there exists a correlation between the RRab class fraction and the total stellar content of a dwarf satellite, we hypothesize that the field halo RRab composition is controlled by the mass of the progenitor contributing the bulk of the stellar debris at the given radius. This idea is tested against a suite of cosmological zoom-in simulations of Milky Way-like stellar halo formation. Finally, we study some of the most prominent stellar streams in the Milky Way halo and demonstrate that their RRab class fractions follow the trends established previously.

  2. Chemical abundances and physical parameters of RR Lyrae stars

    International Nuclear Information System (INIS)

    Manduca, A.

    1980-01-01

    A grid of model stellar atmospheres has been calculated with a range of physical parameters which effectively cover RR Lyrae stars over all phases of their pulsation cycle. The models, calculated with the computer program MARCS, are flux-constant and include the effects of convection and line blanketing. Synthetic spectra were calculated for these models from 3000 A to 9600 A at 0.1 A resolution using the computer program SSG. These spectra were used directly in the applications below and were also used to computer theoretical colors on the UBVR, Stromgren uvby, and Walraven systems for the models. The uvby colors were used in determinations of effective temperature and surface gravity from photometry by various observers. The models, synthetic spectra, and colors were then applied to the problems detailed below. The data collected by Freeman and Rodgers (1975) for 25 RR Lyrae stars in ω Cen was reanalyzed with an alternative, synthetic spectrum approach to the calibration of their theoretical relations. The results confirm a wide range in calcium abundance for the stars in the cluster but at much lower values than reported by Freeman and Rodgers: a range of [Ca/H] = -1.0 to -1.9 was found. A theoretical calibration was performed for the ΔS system of determining metal abundances for RR Lyrae stars. The results support the existing empirical calibration of Butler in the range [Fe/H] = -0.6 to -2.2 and indicate how the calibration should be extrapolated to even lower metal abundances. For higher metal abundances, however, our calibration yields [Fe/H] values lower than Butler by as much as 0.4. Possible explanations of this discrepancy are investigated and the implications are discussed

  3. Extended Aperture Photometry of K2 RR Lyrae stars

    Directory of Open Access Journals (Sweden)

    Plachy Emese

    2017-01-01

    Full Text Available We present the method of the Extended Aperture Photometry (EAP that we applied on K2 RR Lyrae stars. Our aim is to minimize the instrumental variations of attitude control maneuvers by using apertures that cover the positional changes in the field of view thus contain the stars during the whole observation. We present example light curves that we compared to the light curves from the K2 Systematics Correction (K2SC pipeline applied on the automated Single Aperture Photometry (SAP and on the Pre-search Data Conditioning Simple Aperture Photometry (PDCSAP data.

  4. Reddening and blanketing of RR-Lyrae stars, ch. 3

    International Nuclear Information System (INIS)

    Lub, J.

    1977-01-01

    The effects of metal line blanketing and interstellar reddening upon the colours of the RR-Lyrae Stars are discussed. Due to the faintness of these stars in the ultraviolet W channel (at lambda 3720 A) the photometry is in most cases reduced to a four-colour VBLU photometry, i.e. there are only three colour indices available for the determination of the four quantities: interstellar reddening, effective temperature, atmospheric pressure (or effective gravity), and metal line strength which determine the energy distribution that was measured

  5. Extended Aperture Photometry of K2 RR Lyrae stars

    Science.gov (United States)

    Plachy, Emese; Klagyivik, Péter; Molnár, László; Sódor, Ádám; Szabó, Róbert

    2017-10-01

    We present the method of the Extended Aperture Photometry (EAP) that we applied on K2 RR Lyrae stars. Our aim is to minimize the instrumental variations of attitude control maneuvers by using apertures that cover the positional changes in the field of view thus contain the stars during the whole observation. We present example light curves that we compared to the light curves from the K2 Systematics Correction (K2SC) pipeline applied on the automated Single Aperture Photometry (SAP) and on the Pre-search Data Conditioning Simple Aperture Photometry (PDCSAP) data.

  6. THE RR LYRAE VARIABLES AND HORIZONTAL BRANCH OF NGC 6656 (M22) {sup ,}

    Energy Technology Data Exchange (ETDEWEB)

    Kunder, Andrea; Walker, Alistair R.; Paredes Alvarez, Leonardo [Cerro Tololo Inter-American Observatory, Casilla 603, La Serena (Chile); Stetson, Peter B. [Dominion Astrophysical Observatory, NRC-Herzberg, National Research Council, Victoria BC, V9E 2E7 (Canada); Cassisi, Santi [INAF-Osservatorio Astronomico di Collurania, Via M. Maggini, I-64100 Teramo (Italy); Layden, Andrew [Bowling Green State University, Bowling Green, OH 43403 (United States); Bono, Giuseppe [Dipartimento di Fisica, Universita di Roma Tor Vergata, Rome (Italy); Catelan, Márcio [Pontificia Universidad Católica de Chile, Departamento de Astronomía y Astrofísica, Av. Vicuña Mackenna 4860, 782-0436 Macul, Santiago (Chile); Clem, James L. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803-4001 (United States); Matsunaga, Noriyuki [Department of Astronomy, School of Science, The University of Tokyo (Japan); Salaris, Maurizio [Astrophysics Research Institute, Liverpool John Moores University, Twelve Quays House, Egerton Wharf, Birkenhead CH41 1LD (United Kingdom); Lee, Jae-Woo [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of); Chaboyer, Brian, E-mail: akunder@ctio.noao.edu, E-mail: mcatelan@astro.puc.cl [Department of Physics and Astronomy, Dartmouth College, Hanover, NH 03755 (United States)

    2013-11-01

    The first calibrated broadband UBVI time-series photometry is presented for the RR Lyrae variable stars in NGC 6656 (M22), with observations spanning a range of 22 years. We have also redetermined the variability types and periods for the RR Lyrae stars identified previously by photographic observations, revising the number of fundamental-mode RR Lyrae variables (RR0) to 10 and the number of first-overtone variables (RR1) to 16. The mean periods of the RR0 and RR1 variables are (P) {sub RR0} = 0.66 ± 0.02 days and (P) {sub RR1} = 0.33 ± 0.01 days, respectively, supporting an Oosterhoff II classification for the cluster. The number ratio of RR1-type to all RR-type variables is N {sub 1}/N{sub RR} = 0.61, also consistent with an Oosterhoff II designation. Both the RR Lyrae stars' minimum light colors and the blue edge of the RR Lyrae instability strip suggest E( B – – V) = 0.36 ± 0.02 mag toward M22. Regarding the HB morphology of M22, we find (B-R)/(B+V+R) = +0.97 ± 0.1 and at least one ''gap'' located in an unusual part of the blue HB, in the middle of the so-called hot HB stars.

  7. DISTANCE SCALE ZERO POINTS FROM GALACTIC RR LYRAE STAR PARALLAXES

    Energy Technology Data Exchange (ETDEWEB)

    Benedict, G. Fritz; McArthur, Barbara E.; Barnes, Thomas G. [McDonald Observatory, University of Texas, Austin, TX 78712 (United States); Feast, Michael W. [Centre for Astrophysics, Cosmology and Gravitation, Astronomy Department, University of Cape Town, Rondebosch 7701 (South Africa); Harrison, Thomas E. [Department of Astronomy, New Mexico State University, Las Cruces, NM 88003 (United States); Bean, Jacob L.; Kolenberg, Katrien [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Menzies, John W.; Laney, C. D. [South African Astronomical Observatory, Observatory 7935 (South Africa); Chaboyer, Brian [Department of Physics and Astronomy, Dartmouth College, Hanover, NH 03755 (United States); Fossati, Luca [Department of Physics and Astronomy, Open University, Milton Keynes MK7 6AA (United Kingdom); Nesvacil, Nicole [Institute of Astronomy, University of Vienna, A-1180 Vienna (Austria); Smith, Horace A. [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Kochukhov, Oleg [Department of Physics and Astronomy, Uppsala University, 75120 Uppsala (Sweden); Nelan, Edmund P.; Taylor, Denise [STScI, Baltimore, MD 21218 (United States); Shulyak, D. V. [Institute of Astrophysics, Georg-August-University, Friedrich-Hund-Platz 1, D-37077 Goettingen (Germany); Freedman, Wendy L. [The Observatories, Carnegie Institution of Washington, Pasadena, CA 91101 (United States)

    2011-12-15

    We present new absolute trigonometric parallaxes and proper motions for seven Population II variable stars-five RR Lyr variables: RZ Cep, XZ Cyg, SU Dra, RR Lyr, and UV Oct; and two type 2 Cepheids: VY Pyx and {kappa} Pav. We obtained these results with astrometric data from Fine Guidance Sensors, white-light interferometers on Hubble Space Telescope. We find absolute parallaxes in milliseconds of arc: RZ Cep, 2.12 {+-} 0.16 mas; XZ Cyg, 1.67 {+-} 0.17 mas; SU Dra, 1.42 {+-} 0.16 mas; RR Lyr, 3.77 {+-} 0.13 mas; UV Oct, 1.71 {+-} 0.10 mas; VY Pyx, 6.44 {+-} 0.23 mas; and {kappa} Pav, 5.57 {+-} 0.28 mas; an average {sigma}{sub {pi}}/{pi} = 5.4%. With these parallaxes, we compute absolute magnitudes in V and K bandpasses corrected for interstellar extinction and Lutz-Kelker-Hanson bias. Using these RR Lyrae variable star absolute magnitudes, we then derive zero points for M{sub V} -[Fe/H] and M{sub K} -[Fe/H]-log P relations. The technique of reduced parallaxes corroborates these results. We employ our new results to determine distances and ages of several Galactic globular clusters and the distance of the Large Magellanic Cloud. The latter is close to that previously derived from Classical Cepheids uncorrected for any metallicity effect, indicating that any such effect is small. We also discuss the somewhat puzzling results obtained for our two type 2 Cepheids.

  8. A surface brightness analysis of eight RR Lyrae stars

    International Nuclear Information System (INIS)

    Hawley, S.L.; Barnes, T.G. III; Moffett, T.J.

    1987-01-01

    The authors have used a surface brightness, (V-R) relation to analyze new contemporaneous photometry and radial velocity data for 6 RR-ab type stars and to re-analyze previously published data for RR Lyrae and X Arietis. Systematic effects were found in the surface brightness at phases near minimum radius. Excluding these phases, they determine the slope of the surface brightness relation and the mean radius for each star. They also find a zero point which includes both a distance term and the zero point of the surface brightness relation. The sample includes stars with Preston's metallicity indicator ΔS = 0 to 9, with periods ranging from 0.397 days to 0.651 days. Their results indicate a log(R/R solar ) vs. log P relation in the sense that stars with longer periods have larger radii, in agreement with theoretical predictions. Their radii are consistent with bolometric magnitudes in the range 0.2 - 0.8 magnitude but accurate magnitudes must await a reliable T e - color calibration

  9. VBLUM photometry of RR Lyrae stars in ω Cen and M4

    International Nuclear Information System (INIS)

    DeBruijn, J.W.; Lub, J.

    1987-01-01

    Multicolour VBLUW photometry of RR Lyrae stars in the globular clusters M4 and ω Cen is used to derive information on reddening, blanketing, effective temperatures and gravity of these stars. The methods employed in the literature to determine the reddening of globular clusters from the UBV colours of the RR Lyrae stars are in complete agreement with the results from VBLUW photometry. The most important conclusions of the present work are: the close similarity between the RR Lyrae variables in the field and in globular clusters, and the agreement between the reddenings derived for RR Lyrae in the field and in globular clusters. This means that at least one parameter which normally is taken as a free parameter in studying globular cluster colour magnitude diagrams can be constrained very precisely

  10. Carbon and oxygen abundances of field RR Lyrae stars. I. Carbon abundances

    International Nuclear Information System (INIS)

    Butler, D.; Manduca, A.; Deming, D.; Bell, R.A.

    1982-01-01

    From an analysis of KPNO 4-m echelle plates and simultaneous uvbyβ photometry, we have determined carbon abundances and carbon-to-iron ratios for a large number of field RR Lyrae stars having [Fe/H]> or approx. =-1.2. It is found that these field RR Lyrae stars: stars which are known to be in an advanced evolutionary state: have carbon-to-iron ratios which are similar to those of unevolved stars

  11. The VMC survey - XXVI. Structure of the Small Magellanic Cloud from RR Lyrae stars

    Science.gov (United States)

    Muraveva, T.; Subramanian, S.; Clementini, G.; Cioni, M.-R. L.; Palmer, M.; van Loon, J. Th.; Moretti, M. I.; de Grijs, R.; Molinaro, R.; Ripepi, V.; Marconi, M.; Emerson, J.; Ivanov, V. D.

    2018-01-01

    We present results from the analysis of 2997 fundamental mode RR Lyrae variables located in the Small Magellanic Cloud (SMC). For these objects, near-infrared time series photometry from the VISTA survey of the Magellanic Clouds system (VMC) and visual light curves from the OGLE IV (Optical Gravitational Lensing Experiment IV) survey are available. In this study, the multi-epoch Ks-band VMC photometry was used for the first time to derive intensity-averaged magnitudes of the SMC RR Lyrae stars. We determined individual distances to the RR Lyrae stars from the near-infrared period-absolute magnitude-metallicity (PM_{K_s}Z) relation, which has some advantages in comparison with the visual absolute magnitude-metallicity (MV-[Fe/H]) relation, such as a smaller dependence of the luminosity on interstellar extinction, evolutionary effects and metallicity. The distances we have obtained were used to study the three-dimensional structure of the SMC. The distribution of the SMC RR Lyrae stars is found to be ellipsoidal. The actual line-of-sight depth of the SMC is in the range 1-10 kpc, with an average depth of 4.3 ± 1.0 kpc. We found that RR Lyrae stars in the eastern part of the SMC are affected by interactions of the Magellanic Clouds. However, we do not see a clear bimodality observed for red clump stars, in the distribution of RR Lyrae stars.

  12. The effect of Livermore OPAL opacities on the evolutionary masses of RR Lyrae stars

    Science.gov (United States)

    Yi, Sukyoung; Lee, Young-Wook; Demarque, Pierre

    1993-01-01

    We have investigated the effect of the new Livermore OPAL opacities on the evolution of horizontal-branch (HB) stars. This work was motivated by the recent stellar pulsation calculations using the new Livermore opacities, which suggest that the masses of double-mode RR Lyrae stars are 0.1-0.2 solar mass larger than those based on earlier opacities. Unlike the pulsation calculations, we find that the effect of opacity change on the evolution of HB stars is not significant. In particular, the effect of the mean masses of RR Lyrae stars is very small, showing a decrease of only 0.01-0.02 solar mass compared to the models based on old Cox-Stewart opacities. Consequently, with the new Livermore OPAL opacities, both the stellar pulsation and evolution models now predict approximately the same masses for the RR Lyrae stars. Our evolutionary models suggest that the mean masses of the RR Lyrae stars are about 0.76 and about 0.71 solar mass for M15 (Oosterhoff group II) and M3 (group I), respectively. If (alpha/Fe) = 0.4, these values are decreased by about 0.03 solar mass. Variations of the mean masses of RR Lyrae stars with HB morphology and metallicity are also presented.

  13. VizieR Online Data Catalog: Mid-infrared study of RR Lyrae stars (Gavrilchenko+, 2014)

    Science.gov (United States)

    Gavrilchenko, T.; Klein, C. R.; Bloom, J. S.; Richards, J. W.

    2015-02-01

    The first goal was to find a large sample of WISE-observed RR Lyrae stars. A data base of previously identified RR Lyrae stars was created, combining information from General Catalogue of Variable Stars (GCVS), All Sky Automated Survey (ASAS), SIMBAD, VizieR, and individual papers. For many of the sources in this data base the only available data were the coordinates and RR Lyrae classification. When provided, information about the period, distance, subclass, and magnitude for several different wavebands was also stored. If a single source appeared in multiple surveys or papers, information from all relevant surveys was included, with markers indicating contradicting measurements between surveys. The resulting data base contains about 17000 sources, of which about 5000 sources have documented V-band periods. (3 data files).

  14. The ACS LCID project : RR Lyrae stars as tracers of old population gradients in the isolated dwarf spheroidal galaxy tucana

    NARCIS (Netherlands)

    Bernard, Edouard J.; Gallart, Carme; Monelli, Matteo; Aparicio, Antonio; Cassisi, Santi; Skillman, Evan D.; Stetson, Peter B.; Cole, Andrew A.; Drozdovsky, Igor; Hidalgo, Sebastian L.; Mateo, Mario; Tolstoy, Eline

    2008-01-01

    We present a study of the radial distribution of RR Lyrae variables, which present a range of photometric and pulsational properties, in the dwarf spheroidal galaxy Tucana. We find that the fainter RR Lyrae stars, having a shorter period, are more centrally concentrated than the more luminous,

  15. Does Kepler unveil the mystery of the Blazhko effect? First detection of period doubling in Kepler Blazhko RR Lyrae stars

    DEFF Research Database (Denmark)

    Szabó, R.; Kollath, Z.; Molnár, L.

    2010-01-01

    -doubling bifurcation in our non-linear RR Lyrae models computed by the Florida-Budapest hydrocode. This enabled us to trace the origin of this instability in RR Lyrae stars to a resonance, namely a 9:2 resonance between the fundamental mode and a high-order (ninth) radial overtone showing strange-mode characteristics...

  16. VizieR Online Data Catalog: Type II Cepheid and RR Lyrae variables (Feast+, 2008)

    Science.gov (United States)

    Feast, M. W.; Laney, C. D.; Kinman, T. D.; van Leeuwen, F.; Whitelock, P. A.

    2008-10-01

    Infrared and optical absolute magnitudes are derived for the type II Cepheids kappa Pav and VY Pyx using revised Hipparcos parallaxes and for kappa Pav, V553 Cen and SW Tau from pulsational parallaxes. Revised Hipparcos and HST parallaxes for RR Lyrae agree satisfactorily and are combined in deriving absolute magnitudes. Phase-corrected J, H and Ks mags are given for 142 Hipparcos RR Lyraes based on Two-Micron All-Sky Survey observations. Pulsation and trigonometrical parallaxes for classical Cepheids are compared to establish the best value for the projection factor (p) used in pulsational analyses. (3 data files).

  17. A HIGH-VELOCITY BULGE RR LYRAE VARIABLE ON A HALO-LIKE ORBIT

    International Nuclear Information System (INIS)

    Kunder, Andrea; Storm, J.; Rich, R. M.; Hawkins, K.; Poleski, R.; Johnson, C. I.; Shen, J.; Li, Z.-Y.; Cordero, M. J.; Nataf, D. M.; Bono, G.; Walker, A. R.; Koch, A.; De Propris, R.; Udalski, A.; Szymanski, M. K.; Soszynski, I.; Pietrzynski, G.; Ulaczyk, K.; Wyrzykowski, Ł.

    2015-01-01

    We report on the RR Lyrae variable star, MACHO 176.18833.411, located toward the Galactic bulge and observed within the data from the ongoing Bulge RR Lyrae Radial Velocity Assay, which has the unusual radial velocity of −372 ± 8 km s −1 and true space velocity of −482 ± 22 km s −1 relative to the Galactic rest frame. Located less than 1 kpc from the Galactic center and toward a field at (l, b) = (3, −2.5), this pulsating star has properties suggesting it belongs to the bulge RR Lyrae star population, yet a velocity indicating it is abnormal, at least with respect to bulge giants and red clump stars. We show that this star is most likely a halo interloper and therefore suggest that halo contamination is not insignificant when studying metal-poor stars found within the bulge area, even for stars within 1 kpc of the Galactic center. We discuss the possibility that MACHO 176.18833.411 is on the extreme edge of the bulge RR Lyrae radial velocity distribution, and also consider a more exotic scenario in which it is a runaway star moving through the Galaxy

  18. Characterization of the VVV Survey RR Lyrae Population across the Southern Galactic Plane

    International Nuclear Information System (INIS)

    Minniti, Dante; Palma, Tali; Pullen, Joyce; Tissera, Patricia; Dékány, Istvan; Majaess, Daniel; Rejkuba, Marina; Valenti, Elena; Alonso-García, Javier; Catelan, Marcio; Contreras Ramos, Rodrigo; Zoccali, Manuela; Gonzalez, Oscar A.; Hempel, Maren; Irwin, Mike; Lucas, Philip W.; Saito, Roberto K.

    2017-01-01

    Deep near-IR images from the VISTA Variables in the Vía Láctea (VVV) Survey were used to search for RR Lyrae stars in the Southern Galactic plane. A sizable sample of 404 RR Lyrae of type ab stars was identified across a thin slice of the fourth Galactic quadrant (295° < ℓ < 350°, −2.°24 < b < −1.°05). The sample’s distance distribution exhibits a maximum density that occurs at the bulge tangent point, which implies that this primarily Oosterhoff type I population of RRab stars does not trace the bar delineated by their red clump counterparts. The bulge RR Lyrae population does not extend beyond ℓ  ∼ 340°, and the sample’s spatial distribution presents evidence of density enhancements and substructure that warrants further investigation. Indeed, the sample may be employed to evaluate Galactic evolution models, and is particularly lucrative since half of the discovered RR Lyrae are within reach of Gaia astrometric observations.

  19. Characterization of the VVV Survey RR Lyrae Population across the Southern Galactic Plane

    Energy Technology Data Exchange (ETDEWEB)

    Minniti, Dante; Palma, Tali; Pullen, Joyce; Tissera, Patricia [Departamento de Ciencias Físicas, Facultad de Ciencias Exactas, Universidad Andrés Bello, Av. Fernández Concha 700, Las Condes, Santiago (Chile); Dékány, Istvan [Astronomisches Rechen-Institut, Zentrum fuer Astronomie der Universitaet Heidelberg, Moenchhofstr. 12-14, D-69120 Heidelberg (Germany); Majaess, Daniel [Mount Saint Vincent University, Halifax, Nova Scotia (Canada); Rejkuba, Marina; Valenti, Elena [European Southern Observatory, Karl-Schwarszchild-Str. 2, D-85748 Garching bei Muenchen (Germany); Alonso-García, Javier; Catelan, Marcio; Contreras Ramos, Rodrigo; Zoccali, Manuela [Instituto Milenio de Astrofísica, Santiago (Chile); Gonzalez, Oscar A. [Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh, EH9 3HJ (United Kingdom); Hempel, Maren [Pontificia Universidad Católica de Chile, Instituto de Astrofisica, Av. Vicuna Mackenna 4860, Santiago (Chile); Irwin, Mike [Institute of Astronomy, Cambridge University, Cambridge, CB3 0HA (United Kingdom); Lucas, Philip W. [Department of Astronomy, University of Hertfordshire, Hertfordshire (United Kingdom); Saito, Roberto K. [Departamento de Física, Universidade Federal de Santa Catarina, Trindade 88040-900, Florianópolis, SC (Brazil)

    2017-04-01

    Deep near-IR images from the VISTA Variables in the Vía Láctea (VVV) Survey were used to search for RR Lyrae stars in the Southern Galactic plane. A sizable sample of 404 RR Lyrae of type ab stars was identified across a thin slice of the fourth Galactic quadrant (295° < ℓ < 350°, −2.°24 < b < −1.°05). The sample’s distance distribution exhibits a maximum density that occurs at the bulge tangent point, which implies that this primarily Oosterhoff type I population of RRab stars does not trace the bar delineated by their red clump counterparts. The bulge RR Lyrae population does not extend beyond ℓ  ∼ 340°, and the sample’s spatial distribution presents evidence of density enhancements and substructure that warrants further investigation. Indeed, the sample may be employed to evaluate Galactic evolution models, and is particularly lucrative since half of the discovered RR Lyrae are within reach of Gaia astrometric observations.

  20. A HIGH-VELOCITY BULGE RR LYRAE VARIABLE ON A HALO-LIKE ORBIT

    Energy Technology Data Exchange (ETDEWEB)

    Kunder, Andrea; Storm, J. [Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, D-14482 Potsdam (Germany); Rich, R. M. [Department of Physics and Astronomy, University of California at Los Angeles, Los Angeles, CA 90095-1562 (United States); Hawkins, K. [Institute of Astronomy, Madingley Road, Cambridge CB3 0HA (United Kingdom); Poleski, R. [Department of Astronomy, Ohio State University, 140 W. 18th Avenue, Columbus, OH 43210 (United States); Johnson, C. I. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Shen, J.; Li, Z.-Y. [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030 (China); Cordero, M. J. [Astronomisches Rechen-Institut: Zentrum für Astronomie, Mönchhofstr. 12-14, D-69120 Heidelberg (Germany); Nataf, D. M. [Research School of Astronomy and Astrophysics, The Australian National University, Canberra, ACT 2611 (Australia); Bono, G. [Dipartimento di Fisica, Universita di Roma Tor Vergata, Via della Ricerca Scientifica 1, I-00133 Roma (Italy); Walker, A. R. [Cerro Tololo Inter-American Observatory, National Optical Astronomy Observatory, Casilla 603, La Serena (Chile); Koch, A. [Landessternwarte, Zentrum für Astronomie der Universität Heidelberg, Königstuhl 12, D-69117 Heidelberg (Germany); De Propris, R. [Finnish Centre for Astronomy with ESO (FINCA), University of Turku, Turku (Finland); Udalski, A.; Szymanski, M. K.; Soszynski, I.; Pietrzynski, G.; Ulaczyk, K.; Wyrzykowski, Ł. [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland); and others

    2015-07-20

    We report on the RR Lyrae variable star, MACHO 176.18833.411, located toward the Galactic bulge and observed within the data from the ongoing Bulge RR Lyrae Radial Velocity Assay, which has the unusual radial velocity of −372 ± 8 km s{sup −1} and true space velocity of −482 ± 22 km s{sup −1} relative to the Galactic rest frame. Located less than 1 kpc from the Galactic center and toward a field at (l, b) = (3, −2.5), this pulsating star has properties suggesting it belongs to the bulge RR Lyrae star population, yet a velocity indicating it is abnormal, at least with respect to bulge giants and red clump stars. We show that this star is most likely a halo interloper and therefore suggest that halo contamination is not insignificant when studying metal-poor stars found within the bulge area, even for stars within 1 kpc of the Galactic center. We discuss the possibility that MACHO 176.18833.411 is on the extreme edge of the bulge RR Lyrae radial velocity distribution, and also consider a more exotic scenario in which it is a runaway star moving through the Galaxy.

  1. Gaia Data Release 1. Testing parallaxes with local Cepheids and RR Lyrae stars

    NARCIS (Netherlands)

    Gaia Collaboration, [Unknown; Clementini, G.; Eyer, L.; Ripepi, V.; Marconi, M.; Muraveva, T.; Garofalo, A.; Sarro, L. M.; Palmer, M.; Luri, X.; Molinaro, R.; Rimoldini, L.; Szabados, L.; Musella, I.; Anderson, R. I.; Prusti, T.; de Bruijne, J. H. J.; Brown, A. G. A.; Vallenari, A.; Babusiaux, C.; Bailer-Jones, C. A. L.; Bastian, U.; Biermann, M.; Evans, D. W.; Jansen, F.; Jordi, C.; Klioner, S. A.; Lammers, U.; Lindegren, L.; Mignard, F.; Panem, C.; Pourbaix, D.; Randich, S.; Sartoretti, P.; Siddiqui, H. I.; Soubiran, C.; Valette, V.; van Leeuwen, F.; Walton, N. A.; Aerts, C.; Arenou, F.; Cropper, M.; Drimmel, R.; Høg, E.; Katz, D.; Lattanzi, M. G.; O'Mullane, W.; Grebel, E. K.; Holland, A. D.; Huc, C.; Passot, X.; Perryman, M.; Bramante, L.; Cacciari, C.; Castañeda, J.; Chaoul, L.; Cheek, N.; De Angeli, F.; Fabricius, C.; Guerra, R.; Hernández, J.; Jean-Antoine-Piccolo, A.; Masana, E.; Messineo, R.; Mowlavi, N.; Nienartowicz, K.; Ordóñez-Blanco, D.; Panuzzo, P.; Portell, J.; Richards, P. J.; Riello, M.; Seabroke, G. M.; Tanga, P.; Thévenin, F.; Torra, J.; Els, S. G.; Gracia-Abril, G.; Comoretto, G.; Garcia-Reinaldos, M.; Lock, T.; Mercier, E.; Altmann, M.; Andrae, R.; Astraatmadja, T. L.; Bellas-Velidis, I.; Benson, K.; Berthier, J.; Blomme, R.; Busso, G.; Carry, B.; Cellino, A.; Cowell, S.; Creevey, O.; Cuypers, J.; Davidson, M.; De Ridder, J.; de Torres, A.; Delchambre, L.; Dell'Oro, A.; Ducourant, C.; Frémat, Y.; García-Torres, M.; Gosset, E.; Halbwachs, J.-L.; Hambly, N. C.; Harrison, D. L.; Hauser, M.; Hestroffer, D.; Hodgkin, S. T.; Huckle, H. E.; Hutton, A.; Jasniewicz, G.; Jordan, S.; Kontizas, M.; Korn, A. J.; Lanzafame, A. C.; Manteiga, M.; Moitinho, A.; Muinonen, K.; Osinde, J.; Pancino, E.; Pauwels, T.; Petit, J.-M.; Recio-Blanco, A.; Robin, A. C.; Siopis, C.; Smith, M.; Smith, K. W.; Sozzetti, A.; Thuillot, W.; van Reeven, W.; Viala, Y.; Abbas, U.; Abreu Aramburu, A.; Accart, S.; Aguado, J. J.; Allan, P. M.; Allasia, W.; Altavilla, G.; Álvarez, M. A.; Alves, J.; Andrei, A. H.; Anglada Varela, E.; Antiche, E.; Antoja, T.; Antón, S.; Arcay, B.; Bach, N.; Baker, S. G.; Balaguer-Núñez, L.; Barache, C.; Barata, C.; Barbier, A.; Barblan, F.; Barrado y Navascués, D.; Barros, M.; Barstow, M. A.; Becciani, U.; Bellazzini, M.; Bello García, A.; Belokurov, V.; Bendjoya, P.; Berihuete, A.; Bianchi, L.; Bienaymé, O.; Billebaud, F.; Blagorodnova, N.; Blanco-Cuaresma, S.; Boch, T.; Bombrun, A.; Borrachero, R.; Bouquillon, S.; Bourda, G.; Bragaglia, A.; Breddels, M. A.; Brouillet, N.; Brüsemeister, T.; Bucciarelli, B.; Burgess, P.; Burgon, R.; Burlacu, A.; Busonero, D.; Buzzi, R.; Caffau, E.; Cambras, J.; Campbell, H.; Cancelliere, R.; Cantat-Gaudin, T.; Carlucci, T.; Carrasco, J. M.; Castellani, M.; Charlot, P.; Charnas, J.; Chiavassa, A.; Clotet, M.; Cocozza, G.; Collins, R. S.; Costigan, G.; Crifo, F.; Cross, N. J. G.; Crosta, M.; Crowley, C.; Dafonte, C.; Damerdji, Y.; Dapergolas, A.; David, P.; David, M.; De Cat, P.; de Felice, F.; de Laverny, P.; De Luise, F.; De March, R.; de Souza, R.; Debosscher, J.; del Pozo, E.; Delbo, M.; Delgado, A.; Delgado, H. E.; Di Matteo, P.; Diakite, S.; Distefano, E.; Dolding, C.; Dos Anjos, S.; Drazinos, P.; Durán, J.; Dzigan, Y.; Edvardsson, B.; Enke, H.; Evans, N. W.; Eynard Bontemps, G.; Fabre, C.; Fabrizio, M.; Falcão, A. J.; Farràs Casas, M.; Federici, L.; Fedorets, G.; Fernández-Hernández, J.; Fernique, P.; Fienga, A.; Figueras, F.; Filippi, F.; Findeisen, K.; Fonti, A.; Fouesneau, M.; Fraile, E.; Fraser, M.; Fuchs, J.; Gai, M.; Galleti, S.; Galluccio, L.; Garabato, D.; García-Sedano, F.; Garralda, N.; Gavras, P.; Gerssen, J.; Geyer, R.; Gilmore, G.; Girona, S.; Giuffrida, G.; Gomes, M.; González-Marcos, A.; González-Núñez, J.; González-Vidal, J. J.; Granvik, M.; Guerrier, A.; Guillout, P.; Guiraud, J.; Gúrpide, A.; Gutiérrez-Sánchez, R.; Guy, L. P.; Haigron, R.; Hatzidimitriou, D.; Haywood, M.; Heiter, U.; Helmi, A.; Hobbs, D.; Hofmann, W.; Holl, B.; Holland, G.; Hunt, J. A. S.; Hypki, A.; Icardi, V.; Irwin, M.; Jevardat de Fombelle, G.; Jofré, P.; Jonker, P. G.; Jorissen, A.; Julbe, F.; Karampelas, A.; Kochoska, A.; Kohley, R.; Kolenberg, K.; Kontizas, E.; Koposov, S. E.; Kordopatis, G.; Koubsky, P.; Krone-Martins, A.; Kudryashova, M.; Bachchan, R. K.; Lacoste-Seris, F.; Lanza, A. F.; Lavigne, J.-B.; Le Poncin-Lafitte, C.; Lebreton, Y.; Lebzelter, T.; Leccia, S.; Leclerc, N.; Lecoeur-Taibi, I.; Lemaitre, V.; Lenhardt, H.; Leroux, F.; Liao, S.; Licata, E.; Lindstrøm, H. E. P.; Lister, T. A.; Livanou, E.; Lobel, A.; Löffler, W.; López, M.; Lorenz, D.; MacDonald, I.; Magalhães Fernandes, T.; Managau, S.; Mann, R. G.; Mantelet, G.; Marchal, O.; Marchant, J. M.; Marinoni, S.; Marrese, P. M.; Marschalkó, G.; Marshall, D. J.; Martín-Fleitas, J. M.; Martino, M.; Mary, N.; Matijevič, G.; McMillan, P. J.; Messina, S.; Michalik, D.; Millar, N. R.; Miranda, B. M. H.; Molina, D.; Molinaro, M.; Molnár, L.; Moniez, M.; Montegriffo, P.; Mor, R.; Mora, A.; Morbidelli, R.; Morel, T.; Morgenthaler, S.; Morris, D.; Mulone, A. F.; Narbonne, J.; Nelemans, G.; Nicastro, L.; Noval, L.; Ordénovic, C.; Ordieres-Meré, J.; Osborne, P.; Pagani, C.; Pagano, I.; Pailler, F.; Palacin, H.; Palaversa, L.; Parsons, P.; Pecoraro, M.; Pedrosa, R.; Pentikäinen, H.; Pichon, B.; Piersimoni, A. M.; Pineau, F.-X.; Plachy, E.; Plum, G.; Poujoulet, E.; Prša, A.; Pulone, L.; Ragaini, S.; Rago, S.; Rambaux, N.; Ramos-Lerate, M.; Ranalli, P.; Rauw, G.; Read, A.; Regibo, S.; Reylé, C.; Ribeiro, R. A.; Riva, A.; Rixon, G.; Roelens, M.; Romero-Gómez, M.; Rowell, N.; Royer, F.; Ruiz-Dern, L.; Sadowski, G.; Sagristà Sellés, T.; Sahlmann, J.; Salgado, J.; Salguero, E.; Sarasso, M.; Savietto, H.; Schultheis, M.; Sciacca, E.; Segol, M.; Segovia, J. C.; Segransan, D.; Shih, I.-C.; Smareglia, R.; Smart, R. L.; Solano, E.; Solitro, F.; Sordo, R.; Soria Nieto, S.; Souchay, J.; Spagna, A.; Spoto, F.; Stampa, U.; Steele, I. A.; Steidelmüller, H.; Stephenson, C. A.; Stoev, H.; Suess, F. F.; Süveges, M.; Surdej, J.; Szegedi-Elek, E.; Tapiador, D.; Taris, F.; Tauran, G.; Taylor, M. B.; Teixeira, R.; Terrett, D.; Tingley, B.; Trager, S. C.; Turon, C.; Ulla, A.; Utrilla, E.; Valentini, G.; van Elteren, A.; Van Hemelryck, E.; van Leeuwen, M.; Varadi, M.; Vecchiato, A.; Veljanoski, J.; Via, T.; Vicente, D.; Vogt, S.; Voss, H.; Votruba, V.; Voutsinas, S.; Walmsley, G.; Weiler, M.; Weingrill, K.; Wevers, T.; Wyrzykowski, Ł.; Yoldas, A.; Žerjal, M.; Zucker, S.; Zurbach, C.; Zwitter, T.; Alecu, A.; Allen, M.; Allende Prieto, C.; Amorim, A.; Anglada-Escudé, G.; Arsenijevic, V.; Azaz, S.; Balm, P.; Beck, M.; Bernstein, H.-H.; Bigot, L.; Bijaoui, A.; Blasco, C.; Bonfigli, M.; Bono, G.; Boudreault, S.; Bressan, A.; Brown, S.; Brunet, P.-M.; Bunclark†, P.; Buonanno, R.; Butkevich, A. G.; Carret, C.; Carrion, C.; Chemin, L.; Chéreau, F.; Corcione, L.; Darmigny, E.; de Boer, K. S.; de Teodoro, P.; de Zeeuw, P. T.; Delle Luche, C.; Domingues, C. D.; Dubath, P.; Fodor, F.; Frézouls, B.; Fries, A.; Fustes, D.; Fyfe, D.; Gallardo, E.; Gallegos, J.; Gardiol, D.; Gebran, M.; Gomboc, A.; Gómez, A.; Grux, E.; Gueguen, A.; Heyrovsky, A.; Hoar, J.; Iannicola, G.; Isasi Parache, Y.; Janotto, A.-M.; Joliet, E.; Jonckheere, A.; Keil, R.; Kim, D.-W.; Klagyivik, P.; Klar, J.; Knude, J.; Kochukhov, O.; Kolka, I.; Kos, J.; Kutka, A.; Lainey, V.; LeBouquin, D.; Liu, C.; Loreggia, D.; Makarov, V. V.; Marseille, M. G.; Martayan, C.; Martinez-Rubi, O.; Massart, B.; Meynadier, F.; Mignot, S.; Munari, U.; Nguyen, A.-T.; Nordlander, T.; O'Flaherty, K. S.; Ocvirk, P.; Olias Sanz, A.; Ortiz, P.; Osorio, J.; Oszkiewicz, D.; Ouzounis, A.; Park, P.; Pasquato, E.; Peltzer, C.; Peralta, J.; Péturaud, F.; Pieniluoma, T.; Pigozzi, E.; Poels†, J.; Prat, G.; Prod'homme, T.; Raison, F.; Rebordao, J. M.; Risquez, D.; Rocca-Volmerange, B.; Rosen, S.; Ruiz-Fuertes, M. I.; Russo, F.; Serraller Vizcaino, I.; Short, A.; Siebert, A.; Silva, H.; Sinachopoulos, D.; Slezak, E.; Soffel, M.; Sosnowska, D.; Straižys, V.; ter Linden, M.; Terrell, D.; Theil, S.; Tiede, C.; Troisi, L.; Tsalmantza, P.; Tur, D.; Vaccari, M.; Vachier, F.; Valles, P.; Van Hamme, W.; Veltz, L.; Virtanen, J.; Wallut, J.-M.; Wichmann, R.; Wilkinson, M. I.; Ziaeepour, H.; Zschocke, S.

    2017-01-01

    Context. Parallaxes for 331 classical Cepheids, 31 Type II Cepheids, and 364 RR Lyrae stars in common between Gaia and the Hipparcos and Tycho-2 catalogues are published in Gaia Data Release 1 (DR1) as part of the Tycho-Gaia Astrometric Solution (TGAS). Aims: In order to test these first parallax

  2. THE IMPACT OF CONTAMINATED RR LYRAE/GLOBULAR CLUSTER PHOTOMETRY ON THE DISTANCE SCALE

    Energy Technology Data Exchange (ETDEWEB)

    Majaess, D.; Turner, D.; Lane, D. [Department of Astronomy and Physics, Saint Mary' s University, Halifax, NS B3H 3C3 (Canada); Gieren, W., E-mail: dmajaess@ap.smu.ca [Departamento de Astronomia, Universidad de Concepcion, Casilla 160-C, CL Concepcion (Chile)

    2012-06-10

    RR Lyrae variables and the stellar constituents of globular clusters are employed to establish the cosmic distance scale and age of the universe. However, photometry for RR Lyrae variables in the globular clusters M3, M15, M54, M92, NGC 2419, and NGC 6441 exhibit a dependence on the clustercentric distance. For example, variables and stars positioned near the crowded high-surface brightness cores of the clusters may suffer from photometric contamination, which invariably affects a suite of inferred parameters (e.g., distance, color excess, absolute magnitude, etc.). The impetus for this study is to mitigate the propagation of systematic uncertainties by increasing awareness of the pernicious impact of contaminated and radial-dependent photometry.

  3. Gaia Data Release 1. Testing the parallaxes with local Cepheids and RR Lyrae stars

    OpenAIRE

    Gaia Collaboration; Clementini, G.; Eyer, L.; Ripepi, V.; Marconi, M.; Muraveva, T.; Garofalo, A.; Sarro, L. M.; Palmer, M.; Luri, X.; Molinaro, R.; Rimoldini, L.; Szabados, L.; Musella, I.; Anderson, R. I.

    2017-01-01

    Context. Parallaxes for 331 classical Cepheids, 31 Type II Cepheids, and 364 RR Lyrae stars in common between Gaia and the HIPPARCOS and Tycho-2 catalogues are published in Gaia Data Release 1 (DR1) as part of the Tycho-Gaia Astrometric Solution (TGAS). Aims. In order to test these first parallax measurements of the primary standard candles of the cosmological distance ladder, which involve astrometry collected by Gaia during the initial 14 months of science operation, we compared them with l...

  4. Mapping the Tidal Destruction of the Hercules Dwarf: A Wide-field DECam Imaging Search for RR Lyrae Stars

    Science.gov (United States)

    Garling, Christopher; Willman, Beth; Sand, David J.; Hargis, Jonathan; Crnojević, Denija; Bechtol, Keith; Carlin, Jeffrey L.; Strader, Jay; Zou, Hu; Zhou, Xu; Nie, Jundan; Zhang, Tianmeng; Zhou, Zhimin; Peng, Xiyan

    2018-01-01

    We investigate the hypothesized tidal disruption of the Hercules ultra-faint dwarf galaxy (UFD). Previous tidal disruption studies of the Hercules UFD have been hindered by the high degree of foreground contamination in the direction of the dwarf. We bypass this issue by using RR Lyrae stars, which are standard candles with a very low field-volume density at the distance of Hercules. We use wide-field imaging from the Dark Energy Camera on CTIO to identify candidate RR Lyrae stars, supplemented with observations taken in coordination with the Beijing–Arizona Sky Survey on the Bok Telescope. Combining color, magnitude, and light-curve information, we identify three new RR Lyrae stars associated with Hercules. All three of these new RR Lyrae stars lie outside its published tidal radius. When considered with the nine RR Lyrae stars already known within the tidal radius, these results suggest that a substantial fraction of Hercules’ stellar content has been stripped. With this degree of tidal disruption, Hercules is an interesting case between a visibly disrupted dwarf (such as the Sagittarius dwarf spheroidal galaxy) and one in dynamic equilibrium. The degree of disruption also shows that we must be more careful with the ways we determine object membership when estimating dwarf masses in the future. One of the three discovered RR Lyrae stars sits along the minor axis of Hercules, but over two tidal radii away. This type of debris is consistent with recent models that suggest Hercules’ orbit is aligned with its minor axis.

  5. Calcium abundance of RR Lyrae variables in ω Centaurri and M22

    International Nuclear Information System (INIS)

    Manduca, A.; Bell, R.A.

    1978-01-01

    Freeman and Rodgers observed 25 RR Lyrae variables in ω Cen and reported a range in calcium abundance from [Ca/H] = -0.4 to -1.6. This result, however, has been difficult to reconcile with other recent studies of the giant branch of ω Cen. with a model-atmosphere grid covering the physical parameters expected for RR Lyrae variables, Freeman and Rodgers's data were reanalyzed, by use of their basic method of theoretical relations among the equivalent widths of the K, H4b, and H delta lines and [Ca/H] but with an alternative, synthetic-spectrum approach to the calibration of these relations. When interpreted with the present calibration, the data yield a range in calcium abundance from [Ca/H] = -1.0 to -1.9 for the ω Cen RR Lyrae variables. This calibration applied to the M22 data of Butler et al gives [Ca/H] = -1.25 for M22. 2 figures, 1 table

  6. Exploring the Milky Way halo with SDSS-II SN survey RR Lyrae stars

    Science.gov (United States)

    De Lee, Nathan

    This thesis details the creation of a large catalog of RR Lyrae stars, their lightcurves, and their associated photometric and kinematic parameters. This catalog contains 421 RR Lyrae stars with 305 RRab and 116 RRc. Of these, 241 stars have stellar spectra taken with either the Blanco 4m RC spectrograph or the SDSS/SEGUE survey, and in some cases taken by both. From these spectra and photometric methods derived from them, an analysis is conducted of the RR lyrae's distribution, metallicity, kinematics, and photometric properties within the halo. All of these RR Lyrae originate from the SDSS-II Supernova Survey. The SDSS-II SN Survey covers a 2.5 degree equatorial stripe ranging from -60 to +60 degrees in RA. This corresponds to relatively high southern galactic latitudes in the anti-center direction. The full catalog ranges from g 0 magnitude 13 to 20 which covers a distance of 3 to 95 kpc from the sun. Using this sample, we explore the Oosterhoff dichotomy through the D log P method as a function of | Z | distance from the plane. This results in a clear division of the RRab stars into OoI and OoII groups at lower | Z |, but the population becomes dominated by OoI stars at higher | Z |. The idea of a dual halo is explored primarily in the context of radial velocity distributions as a function of | Z |. In particular, V gsr , the radial velocity in the galactic standard of rest, is used as a proxy for V [straight phi] , the cylindrical rotational velocity. This is then compared against a single halo model galaxy, which results in very similar V gsr histograms for both at low to medium | Z |. However, at high | Z | there is a clear separation into two distinct velocity groups for the data without a corresponding separation in the model, suggesting that at least a two-component model for the halo is necessary. The final part of the analysis involves [Fe/H] measurements from both spectra and photometric relations cut in both | Z | and radial velocity. In this case

  7. DISCOVERY OF RR LYRAE STARS IN THE NUCLEAR BULGE OF THE MILKY WAY

    Energy Technology Data Exchange (ETDEWEB)

    Minniti, Dante; Ramos, Rodrigo Contreras; Zoccali, Manuela; Gran, Felipe [Instituto Milenio de Astrofisica, Santiago (Chile); Rejkuba, Marina; Valenti, Elena [European Southern Observatory, Karl-Schwarszchild-Str. 2, D-85748 Garching bei Muenchen (Germany); Gonzalez, Oscar A., E-mail: dante@astrofisica.cl, E-mail: rcontrer@astro.puc.cl [UK Astronomy Technology Centre, Royal Observatory, Blackford Hill, Edinburgh, EH9 3HJ (United Kingdom)

    2016-10-10

    Galactic nuclei, such as that of the Milky Way, are extreme regions with high stellar densities, and in most cases, the hosts of a supermassive black hole. One of the scenarios proposed for the formation of the Galactic nucleus is merging of primordial globular clusters. An implication of this model is that this region should host stars that are characteristically found in old Milky Way globular clusters. RR Lyrae stars are primary distance indicators, well known representatives of old and metal-poor stellar populations, and therefore are regularly found in globular clusters. Here we report the discovery of a dozen RR Lyrae type ab stars in the vicinity of the Galactic center, i.e., in the so-called nuclear stellar bulge of the Milky Way. This discovery provides the first direct observational evidence that the Galactic nuclear stellar bulge contains ancient stars (>10 Gyr old). Based on this we conclude that merging globular clusters likely contributed to the build-up of the high stellar density in the nuclear stellar bulge of the Milky Way.

  8. Ground-based photometry for 42 Kepler-field RR Lyrae stars

    Science.gov (United States)

    Jeon, Young-Beom; Ngeow, Chow-Choong; Nemec, James M.

    2014-02-01

    Follow-up (U)BVRI photometric observations have been carried out for 42 RR Lyrae stars in the Kepler field. The new magnitude and color information will complement the available extensive high-precision Kepler photometry and recent spectroscopic results. The photometric observations were made with the following telescopes: 1-m and 41-cm telescopes of Lulin Observatory (Taiwan), 81-cm telescope of Tenagra Observatory (Arizona, USA), 1-m telescope at the Mt. Lemmon Optical Astronomy Observatory (LOAO, Arizona, USA), 1.8-m and 15-cm telescopes at the Bohyunsan Optical Astronomy Observatory (BOAO, Korea) and 61-cm telescope at the Sobaeksan Optical Astronomy Observatory (SOAO, Korea). The observations span from 2010 to 2013, with ~200 to ~600 data points per light curve. Preliminary results of the Korean observations were presented at the 5th KASC workshop in Hungary. In this work, we analyze all observations. These observations permit the construction of full light curves for these RR Lyrae stars and can be used to derive multi-filter Fourier parameters.

  9. Machine-learned Identification of RR Lyrae Stars from Sparse, Multi-band Data: The PS1 Sample

    Science.gov (United States)

    Sesar, Branimir; Hernitschek, Nina; Mitrović, Sandra; Ivezić, Željko; Rix, Hans-Walter; Cohen, Judith G.; Bernard, Edouard J.; Grebel, Eva K.; Martin, Nicolas F.; Schlafly, Edward F.; Burgett, William S.; Draper, Peter W.; Flewelling, Heather; Kaiser, Nick; Kudritzki, Rolf P.; Magnier, Eugene A.; Metcalfe, Nigel; Tonry, John L.; Waters, Christopher

    2017-05-01

    RR Lyrae stars may be the best practical tracers of Galactic halo (sub-)structure and kinematics. The PanSTARRS1 (PS1) 3π survey offers multi-band, multi-epoch, precise photometry across much of the sky, but a robust identification of RR Lyrae stars in this data set poses a challenge, given PS1's sparse, asynchronous multi-band light curves (≲ 12 epochs in each of five bands, taken over a 4.5 year period). We present a novel template fitting technique that uses well-defined and physically motivated multi-band light curves of RR Lyrae stars, and demonstrate that we get accurate period estimates, precise to 2 s in > 80 % of cases. We augment these light-curve fits with other features from photometric time-series and provide them to progressively more detailed machine-learned classification models. From these models, we are able to select the widest (three-fourths of the sky) and deepest (reaching 120 kpc) sample of RR Lyrae stars to date. The PS1 sample of ˜45,000 RRab stars is pure (90%) and complete (80% at 80 kpc) at high galactic latitudes. It also provides distances that are precise to 3%, measured with newly derived period-luminosity relations for optical/near-infrared PS1 bands. With the addition of proper motions from Gaia and radial velocity measurements from multi-object spectroscopic surveys, we expect the PS1 sample of RR Lyrae stars to become the premier source for studying the structure, kinematics, and the gravitational potential of the Galactic halo. The techniques presented in this study should translate well to other sparse, multi-band data sets, such as those produced by the Dark Energy Survey and the upcoming Large Synoptic Survey Telescope Galactic plane sub-survey.

  10. Galactic archaeology for amateur astronomers: RR Lyrae stars as tracers of the Milky Way formation

    Science.gov (United States)

    Carballo-Bello, Julio A.; Martínez-Delgado, David; Fliri, Jürgen

    2011-06-01

    Cosmological models predict that large galaxies like the Milky Way formed from the accretion of smaller stellar systems. The most spectacular of these merger events are stellar tidal streams, rivers of stars and dark matter that envelop the discs of spiral galaxies. We present a research project for a collaboration with amateur astronomers in the study of the formation process of our Galaxy. The main objective is the search for RR Lyrae variable stars in the known stellar streams (Sagitarius, Monoceros, Orphan, etc) a project that can be carried out using small telescopes. The catalogue of candidate variable stars were selected from SDSS data based in colour criteria and it will be sent to interested amateur astronomers who wish to participate in scientific research in one of the most active and competitive topics in Galactic astronomy.

  11. Gaia Data Release 1. Testing parallaxes with local Cepheids and RR Lyrae stars

    Science.gov (United States)

    Gaia Collaboration; Clementini, G.; Eyer, L.; Ripepi, V.; Marconi, M.; Muraveva, T.; Garofalo, A.; Sarro, L. M.; Palmer, M.; Luri, X.; Molinaro, R.; Rimoldini, L.; Szabados, L.; Musella, I.; Anderson, R. I.; Prusti, T.; de Bruijne, J. H. J.; Brown, A. G. A.; Vallenari, A.; Babusiaux, C.; Bailer-Jones, C. A. L.; Bastian, U.; Biermann, M.; Evans, D. W.; Jansen, F.; Jordi, C.; Klioner, S. A.; Lammers, U.; Lindegren, L.; Mignard, F.; Panem, C.; Pourbaix, D.; Randich, S.; Sartoretti, P.; Siddiqui, H. I.; Soubiran, C.; Valette, V.; van Leeuwen, F.; Walton, N. A.; Aerts, C.; Arenou, F.; Cropper, M.; Drimmel, R.; Høg, E.; Katz, D.; Lattanzi, M. G.; O'Mullane, W.; Grebel, E. K.; Holland, A. D.; Huc, C.; Passot, X.; Perryman, M.; Bramante, L.; Cacciari, C.; Castañeda, J.; Chaoul, L.; Cheek, N.; De Angeli, F.; Fabricius, C.; Guerra, R.; Hernández, J.; Jean-Antoine-Piccolo, A.; Masana, E.; Messineo, R.; Mowlavi, N.; Nienartowicz, K.; Ordóñez-Blanco, D.; Panuzzo, P.; Portell, J.; Richards, P. J.; Riello, M.; Seabroke, G. M.; Tanga, P.; Thévenin, F.; Torra, J.; Els, S. G.; Gracia-Abril, G.; Comoretto, G.; Garcia-Reinaldos, M.; Lock, T.; Mercier, E.; Altmann, M.; Andrae, R.; Astraatmadja, T. L.; Bellas-Velidis, I.; Benson, K.; Berthier, J.; Blomme, R.; Busso, G.; Carry, B.; Cellino, A.; Cowell, S.; Creevey, O.; Cuypers, J.; Davidson, M.; De Ridder, J.; de Torres, A.; Delchambre, L.; Dell'Oro, A.; Ducourant, C.; Frémat, Y.; García-Torres, M.; Gosset, E.; Halbwachs, J.-L.; Hambly, N. C.; Harrison, D. L.; Hauser, M.; Hestroffer, D.; Hodgkin, S. T.; Huckle, H. E.; Hutton, A.; Jasniewicz, G.; Jordan, S.; Kontizas, M.; Korn, A. J.; Lanzafame, A. C.; Manteiga, M.; Moitinho, A.; Muinonen, K.; Osinde, J.; Pancino, E.; Pauwels, T.; Petit, J.-M.; Recio-Blanco, A.; Robin, A. C.; Siopis, C.; Smith, M.; Smith, K. W.; Sozzetti, A.; Thuillot, W.; van Reeven, W.; Viala, Y.; Abbas, U.; Abreu Aramburu, A.; Accart, S.; Aguado, J. J.; Allan, P. M.; Allasia, W.; Altavilla, G.; Álvarez, M. A.; Alves, J.; Andrei, A. H.; Anglada Varela, E.; Antiche, E.; Antoja, T.; Antón, S.; Arcay, B.; Bach, N.; Baker, S. G.; Balaguer-Núñez, L.; Barache, C.; Barata, C.; Barbier, A.; Barblan, F.; Barrado y Navascués, D.; Barros, M.; Barstow, M. A.; Becciani, U.; Bellazzini, M.; Bello García, A.; Belokurov, V.; Bendjoya, P.; Berihuete, A.; Bianchi, L.; Bienaymé, O.; Billebaud, F.; Blagorodnova, N.; Blanco-Cuaresma, S.; Boch, T.; Bombrun, A.; Borrachero, R.; Bouquillon, S.; Bourda, G.; Bragaglia, A.; Breddels, M. A.; Brouillet, N.; Brüsemeister, T.; Bucciarelli, B.; Burgess, P.; Burgon, R.; Burlacu, A.; Busonero, D.; Buzzi, R.; Caffau, E.; Cambras, J.; Campbell, H.; Cancelliere, R.; Cantat-Gaudin, T.; Carlucci, T.; Carrasco, J. M.; Castellani, M.; Charlot, P.; Charnas, J.; Chiavassa, A.; Clotet, M.; Cocozza, G.; Collins, R. S.; Costigan, G.; Crifo, F.; Cross, N. J. G.; Crosta, M.; Crowley, C.; Dafonte, C.; Damerdji, Y.; Dapergolas, A.; David, P.; David, M.; De Cat, P.; de Felice, F.; de Laverny, P.; De Luise, F.; De March, R.; de Souza, R.; Debosscher, J.; del Pozo, E.; Delbo, M.; Delgado, A.; Delgado, H. E.; Di Matteo, P.; Diakite, S.; Distefano, E.; Dolding, C.; Dos Anjos, S.; Drazinos, P.; Durán, J.; Dzigan, Y.; Edvardsson, B.; Enke, H.; Evans, N. W.; Eynard Bontemps, G.; Fabre, C.; Fabrizio, M.; Falcão, A. J.; Farràs Casas, M.; Federici, L.; Fedorets, G.; Fernández-Hernández, J.; Fernique, P.; Fienga, A.; Figueras, F.; Filippi, F.; Findeisen, K.; Fonti, A.; Fouesneau, M.; Fraile, E.; Fraser, M.; Fuchs, J.; Gai, M.; Galleti, S.; Galluccio, L.; Garabato, D.; García-Sedano, F.; Garralda, N.; Gavras, P.; Gerssen, J.; Geyer, R.; Gilmore, G.; Girona, S.; Giuffrida, G.; Gomes, M.; González-Marcos, A.; González-Núñez, J.; González-Vidal, J. J.; Granvik, M.; Guerrier, A.; Guillout, P.; Guiraud, J.; Gúrpide, A.; Gutiérrez-Sánchez, R.; Guy, L. P.; Haigron, R.; Hatzidimitriou, D.; Haywood, M.; Heiter, U.; Helmi, A.; Hobbs, D.; Hofmann, W.; Holl, B.; Holland, G.; Hunt, J. A. S.; Hypki, A.; Icardi, V.; Irwin, M.; Jevardat de Fombelle, G.; Jofré, P.; Jonker, P. G.; Jorissen, A.; Julbe, F.; Karampelas, A.; Kochoska, A.; Kohley, R.; Kolenberg, K.; Kontizas, E.; Koposov, S. E.; Kordopatis, G.; Koubsky, P.; Krone-Martins, A.; Kudryashova, M.; Bachchan, R. K.; Lacoste-Seris, F.; Lanza, A. F.; Lavigne, J.-B.; Le Poncin-Lafitte, C.; Lebreton, Y.; Lebzelter, T.; Leccia, S.; Leclerc, N.; Lecoeur-Taibi, I.; Lemaitre, V.; Lenhardt, H.; Leroux, F.; Liao, S.; Licata, E.; Lindstrøm, H. E. P.; Lister, T. A.; Livanou, E.; Lobel, A.; Löffler, W.; López, M.; Lorenz, D.; MacDonald, I.; Magalhães Fernandes, T.; Managau, S.; Mann, R. G.; Mantelet, G.; Marchal, O.; Marchant, J. M.; Marinoni, S.; Marrese, P. M.; Marschalkó, G.; Marshall, D. J.; Martín-Fleitas, J. M.; Martino, M.; Mary, N.; Matijevič, G.; McMillan, P. J.; Messina, S.; Michalik, D.; Millar, N. R.; Miranda, B. M. H.; Molina, D.; Molinaro, M.; Molnár, L.; Moniez, M.; Montegriffo, P.; Mor, R.; Mora, A.; Morbidelli, R.; Morel, T.; Morgenthaler, S.; Morris, D.; Mulone, A. F.; Narbonne, J.; Nelemans, G.; Nicastro, L.; Noval, L.; Ordénovic, C.; Ordieres-Meré, J.; Osborne, P.; Pagani, C.; Pagano, I.; Pailler, F.; Palacin, H.; Palaversa, L.; Parsons, P.; Pecoraro, M.; Pedrosa, R.; Pentikäinen, H.; Pichon, B.; Piersimoni, A. M.; Pineau, F.-X.; Plachy, E.; Plum, G.; Poujoulet, E.; Prša, A.; Pulone, L.; Ragaini, S.; Rago, S.; Rambaux, N.; Ramos-Lerate, M.; Ranalli, P.; Rauw, G.; Read, A.; Regibo, S.; Reylé, C.; Ribeiro, R. A.; Riva, A.; Rixon, G.; Roelens, M.; Romero-Gómez, M.; Rowell, N.; Royer, F.; Ruiz-Dern, L.; Sadowski, G.; Sagristà Sellés, T.; Sahlmann, J.; Salgado, J.; Salguero, E.; Sarasso, M.; Savietto, H.; Schultheis, M.; Sciacca, E.; Segol, M.; Segovia, J. C.; Segransan, D.; Shih, I.-C.; Smareglia, R.; Smart, R. L.; Solano, E.; Solitro, F.; Sordo, R.; Soria Nieto, S.; Souchay, J.; Spagna, A.; Spoto, F.; Stampa, U.; Steele, I. A.; Steidelmüller, H.; Stephenson, C. A.; Stoev, H.; Suess, F. F.; Süveges, M.; Surdej, J.; Szegedi-Elek, E.; Tapiador, D.; Taris, F.; Tauran, G.; Taylor, M. B.; Teixeira, R.; Terrett, D.; Tingley, B.; Trager, S. C.; Turon, C.; Ulla, A.; Utrilla, E.; Valentini, G.; van Elteren, A.; Van Hemelryck, E.; van Leeuwen, M.; Varadi, M.; Vecchiato, A.; Veljanoski, J.; Via, T.; Vicente, D.; Vogt, S.; Voss, H.; Votruba, V.; Voutsinas, S.; Walmsley, G.; Weiler, M.; Weingrill, K.; Wevers, T.; Wyrzykowski, Ł.; Yoldas, A.; Žerjal, M.; Zucker, S.; Zurbach, C.; Zwitter, T.; Alecu, A.; Allen, M.; Allende Prieto, C.; Amorim, A.; Anglada-Escudé, G.; Arsenijevic, V.; Azaz, S.; Balm, P.; Beck, M.; Bernstein, H.-H.; Bigot, L.; Bijaoui, A.; Blasco, C.; Bonfigli, M.; Bono, G.; Boudreault, S.; Bressan, A.; Brown, S.; Brunet, P.-M.; Bunclark, P.; Buonanno, R.; Butkevich, A. G.; Carret, C.; Carrion, C.; Chemin, L.; Chéreau, F.; Corcione, L.; Darmigny, E.; de Boer, K. S.; de Teodoro, P.; de Zeeuw, P. T.; Delle Luche, C.; Domingues, C. D.; Dubath, P.; Fodor, F.; Frézouls, B.; Fries, A.; Fustes, D.; Fyfe, D.; Gallardo, E.; Gallegos, J.; Gardiol, D.; Gebran, M.; Gomboc, A.; Gómez, A.; Grux, E.; Gueguen, A.; Heyrovsky, A.; Hoar, J.; Iannicola, G.; Isasi Parache, Y.; Janotto, A.-M.; Joliet, E.; Jonckheere, A.; Keil, R.; Kim, D.-W.; Klagyivik, P.; Klar, J.; Knude, J.; Kochukhov, O.; Kolka, I.; Kos, J.; Kutka, A.; Lainey, V.; LeBouquin, D.; Liu, C.; Loreggia, D.; Makarov, V. V.; Marseille, M. G.; Martayan, C.; Martinez-Rubi, O.; Massart, B.; Meynadier, F.; Mignot, S.; Munari, U.; Nguyen, A.-T.; Nordlander, T.; O'Flaherty, K. S.; Ocvirk, P.; Olias Sanz, A.; Ortiz, P.; Osorio, J.; Oszkiewicz, D.; Ouzounis, A.; Park, P.; Pasquato, E.; Peltzer, C.; Peralta, J.; Péturaud, F.; Pieniluoma, T.; Pigozzi, E.; Poels, J.; Prat, G.; Prod'homme, T.; Raison, F.; Rebordao, J. M.; Risquez, D.; Rocca-Volmerange, B.; Rosen, S.; Ruiz-Fuertes, M. I.; Russo, F.; Serraller Vizcaino, I.; Short, A.; Siebert, A.; Silva, H.; Sinachopoulos, D.; Slezak, E.; Soffel, M.; Sosnowska, D.; Straižys, V.; ter Linden, M.; Terrell, D.; Theil, S.; Tiede, C.; Troisi, L.; Tsalmantza, P.; Tur, D.; Vaccari, M.; Vachier, F.; Valles, P.; Van Hamme, W.; Veltz, L.; Virtanen, J.; Wallut, J.-M.; Wichmann, R.; Wilkinson, M. I.; Ziaeepour, H.; Zschocke, S.

    2017-09-01

    Context. Parallaxes for 331 classical Cepheids, 31 Type II Cepheids, and 364 RR Lyrae stars in common between Gaia and the Hipparcos and Tycho-2 catalogues are published in Gaia Data Release 1 (DR1) as part of the Tycho-Gaia Astrometric Solution (TGAS). Aims: In order to test these first parallax measurements of the primary standard candles of the cosmological distance ladder, which involve astrometry collected by Gaia during the initial 14 months of science operation, we compared them with literature estimates and derived new period-luminosity (PL), period-Wesenheit (PW) relations for classical and Type II Cepheids and infrared PL, PL-metallicity (PLZ), and optical luminosity-metallicity (MV-[Fe/H]) relations for the RR Lyrae stars, with zero points based on TGAS. Methods: Classical Cepheids were carefully selected in order to discard known or suspected binary systems. The final sample comprises 102 fundamental mode pulsators with periods ranging from 1.68 to 51.66 days (of which 33 with σϖ/ϖimpressive. Conclusions: TGAS parallaxes bring a significant added value to the previous Hipparcos estimates. The relations presented in this paper represent the first Gaia-calibrated relations and form a work-in-progress milestone report in the wait for Gaia-only parallaxes of which a first solution will become available with Gaia Data Release 2 (DR2) in 2018. Full Tables A.1-A.3 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/605/A79

  12. The occurrence of binary evolution pulsators in classical instability strip of RR Lyrae and Cepheid variables

    Science.gov (United States)

    Karczmarek, P.; Wiktorowicz, G.; Iłkiewicz, K.; Smolec, R.; Stępień, K.; Pietrzyński, G.; Gieren, W.; Belczynski, K.

    2017-04-01

    Single star evolution does not allow extremely low-mass stars to cross the classical instability strip (IS) during the Hubble time. However, within binary evolution framework low-mass stars can appear inside the IS once the mass transfer (MT) is taken into account. Triggered by a discovery of low-mass (0.26 M⊙) RR Lyrae-like variable in a binary system, OGLE-BLG-RRLYR-02792, we investigate the occurrence of similar binary components in the IS, which set up a new class of low-mass pulsators. They are referred to as binary evolution pulsators (BEPs) to underline the interaction between components, which is crucial for substantial mass-loss prior to the IS entrance. We simulate a population of 500 000 metal-rich binaries and report that 28 143 components of binary systems experience severe MT (losing up to 90 per cent of mass), followed by at least one IS crossing in luminosity range of RR Lyrae (RRL) or Cepheid variables. A half of these systems enter the IS before the age of 4 Gyr. BEPs display a variety of physical and orbital parameters, with the most important being the BEP mass in range 0.2-0.8 M⊙, and the orbital period in range 10-2 500 d. Based on the light curve only, BEPs can be misclassified as genuine classical pulsators, and as such they would contaminate genuine RRL and classical Cepheid variables at levels of 0.8 and 5 per cent, respectively. We state that the majority of BEPs will remain undetected and we discuss relevant detection limitations.

  13. On the RR Lyrae Stars in Globulars. V. The Complete Near-infrared (JHK s ) Census of ω Centauri RR Lyrae Variables

    Science.gov (United States)

    Braga, V. F.; Stetson, P. B.; Bono, G.; Dall’Ora, M.; Ferraro, I.; Fiorentino, G.; Iannicola, G.; Marconi, M.; Marengo, M.; Monson, A. J.; Neeley, J.; Persson, S. E.; Beaton, R. L.; Buonanno, R.; Calamida, A.; Castellani, M.; Di Carlo, E.; Fabrizio, M.; Freedman, W. L.; Inno, L.; Madore, B. F.; Magurno, D.; Marchetti, E.; Marinoni, S.; Marrese, P.; Matsunaga, N.; Minniti, D.; Monelli, M.; Nonino, M.; Piersimoni, A. M.; Pietrinferni, A.; Prada-Moroni, P.; Pulone, L.; Stellingwerf, R.; Tognelli, E.; Walker, A. R.; Valenti, E.; Zoccali, M.

    2018-03-01

    We present a new complete near-infrared (NIR, JHK s ) census of RR Lyrae stars (RRLs) in the globular ω Cen (NGC 5139). We collected 15,472 JHK s images with 4–8 m class telescopes over 15 years (2000–2015) covering a sky area around the cluster center of 60 × 34 arcmin2. These images provided calibrated photometry for 182 out of the 198 cluster RRL candidates with 10 to 60 measurements per band. We also provide new homogeneous estimates of the photometric amplitude for 180 (J), 176 (H) and 174 (K s ) RRLs. These data were supplemented with single-epoch JK s magnitudes from VHS and with single-epoch H magnitudes from 2MASS. Using proprietary optical and NIR data together with new optical light curves (ASAS-SN) we also updated pulsation periods for 59 candidate RRLs. As a whole, we provide JHK s magnitudes for 90 RRab (fundamentals), 103 RRc (first overtones) and one RRd (mixed-mode pulsator). We found that NIR/optical photometric amplitude ratios increase when moving from first overtone to fundamental and to long-period (P > 0.7 days) fundamental RRLs. Using predicted period–luminosity–metallicity relations, we derive a true distance modulus of 13.674 ± 0.008 ± 0.038 mag (statistical error and standard deviation of the median) based on spectroscopic iron abundances, and of 13.698 ± 0.004 ± 0.048 mag based on photometric iron abundances. We also found evidence of possible systematics at the 5%–10% level in the zero-point of the period–luminosity relations based on the five calibrating RRLs whose parallaxes had been determined with the HST. This publication makes use of data gathered with the Magellan/Baade Telescope at Las Campanas Observatory, the Blanco Telescope at Cerro Tololo Inter-American Observatory, NTT at La Silla (ESO Program IDs: 64.N-0038(A), 66.D-0557(A), 68.D-0545(A), 073.D-0313(A), ID 073.D-0313(A) and 59.A-9004(D)), VISTA at Paranal (ESO Program ID: 179.A-2010) and VLT at Paranal (ESO Program ID: ID96406).

  14. Gaia’s Cepheids and RR Lyrae stars and luminosity calibrations based on Tycho-Gaia Astrometric Solution

    Directory of Open Access Journals (Sweden)

    Clementini Gisella

    2017-01-01

    Full Text Available Gaia Data Release 1 contains parallaxes for more than 700 Galactic Cepheids and RR Lyrae stars, computed as part of the Tycho-Gaia Astrometric Solution (TGAS. We have used TGAS parallaxes, along with literature (V, I, J, Ks, W1 photometry and spectroscopy, to calibrate the zero point of the period-luminosity and period-Wesenheit relations of classical and type II Cepheids, and the near-infrared period-luminosity, period-luminosity-metallicity and optical luminosity-metallicity relations of RR Lyrae stars. In this contribution we briefly summarise results obtained by fitting these basic relations adopting different techniques that operate either in parallax or distance (absolute magnitude space.

  15. VizieR Online Data Catalog: Abundances of 8 RR Lyrae subclass C variable stars (Govea+, 2014)

    Science.gov (United States)

    Govea, J.; Gomez, T.; Preston, G. W.; Sneden, C.

    2016-02-01

    We chose 10 candidate RR Lyrae variable stars of subclass c (RRc) stars for spectroscopic observation. Many of these stars were first identified as RRc variables by the All Sky Automated Survey (ASAS) of Pojmanski 2003 (cat. II/264). The target star list included ASAS 144154-0324.7 and ASAS 204440-2402.7. But our spectroscopic study suggest that these two stars are probably W UMa binaries instead of RR Lyrae stars Our spectra were obtained with the echelle spectrograph of the du Pont 2.5m telescope at the Las Campanas Observatory. Four observing runs during 2009-2010 were partly devoted to this project. The spectrograph was used with the 1.5*4'' entrance slit, which translates to a resolving power of R=λ/Δλ~27000 at the MgI b lines near 5180Å. The total continuous wavelength coverage of the spectra was 3500-9000Å. (6 data files).

  16. CCD time-series photometry of the globular cluster NGC 5053: RR Lyrae, Blue Stragglers and SX Phoenicis stars revisited

    Science.gov (United States)

    Arellano Ferro, A.; Giridhar, Sunetra; Bramich, D. M.

    2010-02-01

    We report the results of CCD V, r and I time-series photometry of the globular cluster NGC 5053. New times of maximum light are given for the eight known RR Lyrae stars in the field of our images, and their periods are revised. Their V light curves were Fourier decomposed to estimate their physical parameters. A discussion on the accuracy of the Fourier-based iron abundances, temperatures, masses and radii is given. New periods are found for the five known SX Phe stars, and a critical discussion of their secular period changes is offered. The mean iron abundance for the RR Lyrae stars is found to be [Fe/H] ~ -1.97 +/- 0.16 and lower values are not supported by the present analysis. The absolute magnitude calibrations of the RR Lyrae stars yield an average true distance modulus of 16.12 +/- 0.04 or a distance of 16.7 +/- 0.3 kpc. Comparison of the observational colour magnitude diagram (CMD) with theoretical isochrones indicates an age of 12.5 +/- 2.0 Gyr for the cluster. A careful identification of all reported blue stragglers (BS) and their V, I magnitudes leads to the conclusion that BS12, BS22, BS23 and BS24 are not BS. On the other hand, three new BS are reported. Variability was found in seven BS, very likely of the SX Phe type in five of them, and in one red giant star. The new SX Phe stars follow established Period-Luminosity relationships and indicate a distance in agreement with the distance from the RR Lyrae stars. Based on observations collected at the Indian Astrophysical Observatory, Hanle, India. E-mail: armando@astroscu.unam.mx (AAF); giridhar@iiap.res.in (SG); dan.bramich@hotmail.co.uk (DMB)

  17. The first all-sky view of the Milky Way stellar halo with Gaia+2MASS RR Lyrae

    Science.gov (United States)

    Iorio, G.; Belokurov, V.; Erkal, D.; Koposov, S. E.; Nipoti, C.; Fraternali, F.

    2018-02-01

    We exploit the first Gaia data release to study the properties of the Galactic stellar halo as traced by RR Lyrae. We demonstrate that it is possible to select a pure sample of RR Lyrae using only photometric information available in the Gaia+2MASS catalogue. The final sample contains about 21 600 RR Lyrae covering an unprecedented fraction ( ˜ 60 per cent) of the volume of the Galactic inner halo (R < 28 kpc). We study the morphology of the stellar halo by analysing the RR Lyrae distribution with parametric and non-parametric techniques. Taking advantage of the uniform all-sky coverage, we test halo models more sophisticated than usually considered in the literature, such as those with varying flattening, tilts and/or offset of the halo with respect to the Galactic disc. A consistent picture emerges: the inner halo is well reproduced by a smooth distribution of stars settled on triaxial density ellipsoids. The shortest axis is perpendicular to the Milky Way's disc, while the longest axis forms an angle of ˜70° with the axis connecting the Sun and the Galactic Centre. The elongation along the major axis is mild (p = 1.27), and the vertical flattening is shown to evolve from a squashed state with q ≈ 0.57 in the centre to a more spherical q ≈ 0.75 at the outer edge of our data set. Within the radial range probed, the density profile of the stellar halo is well approximated by a single power law with exponent α = -2.96. We do not find evidence of tilt or offset of the halo with respect to the Galaxy's disc.

  18. Macho project photometry of RR Lyrae stars in the Sagittarius dwarf galaxy

    Energy Technology Data Exchange (ETDEWEB)

    Alcock, C. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)]|[Center for Particle Astrophysics, University of California, Berkeley, California 94720 (United States); Allsman, R.A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)]|[Mount Stromlo and Siding Spring Observatories, Australian National University, Weston, ACT 2611 (Australia); Alves, D.R. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)]|[Department of Physics, University of California, Davis, California 95616 (United States); Axelrod, T.S. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)]|[Mount Stromlo and Siding Spring Observatories, Australian National University, Weston, ACT 2611 (Australia); Becker, A.C. [Center for Particle Astrophysics, University of California, Berkeley, California 94720 (United States)]|[Department of Astronomy, University of Washington, Seattle, Washington 98195 (United States); Bennett, D.P.; Cook, K.H. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)]|[Center for Particle Astrophysics, University of California, Berkeley, California 94720 (United States); Freeman, K.C. [Mount Stromlo and Siding Spring Observatories, Australian National University, Weston, ACT 2611 (Australia); Griest, K. [Center for Particle Astrophysics, University of California, Berkeley, California 94720 (United States)]|[Department of Physics, University of California, San Diego, California 92093 (United States); Guern, J.A.; Lehner, M.J. [Department of Physics, University of California, San Diego, California 92093 (United States); Marshall, S.L.; Minniti, D. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Peterson, B.A. [Mount Stromlo and Siding Spring Observatories, Australian National University, Weston, ACT 2611 (Australia); Pratt, M.R.

    1997-01-01

    We report the discovery of 30 type a, b RR Lyrae (RRab) stars that are likely members of the Sagittarius dwarf galaxy (Sgr). Accurate positions, periods, amplitudes, and magnitudes are presented. Their distances are determined with respect to RRab stars in the Galactic bulge found also in the MACHO 1993 data. For R{sub {circle_dot}}=8kpc, the mean distance to these stars is D=22{plus_minus}1kpc, smaller than previous determinations for this galaxy. This indicates that Sgr has an elongated main body extending for more than 10 kpc, which is inclined along the line of sight, with its northern part (in Galactic coordinates) closer to us. The size and shape of Sgr give clues about the past history of this galaxy. If the shape of Sgr follows the direction of its orbit, the observed spatial orientation suggests that Sgr is moving away from the Galactic plane. Also, Sgr stars may be the sources of some of the microlensing events seen toward the bulge. {copyright} {ital 1997} {ital The American Astronomical Society}

  19. Dependence of the red edge of the RR Lyrae gap on helium abundance

    International Nuclear Information System (INIS)

    Deupree, R.G.

    1976-01-01

    Calculations have been performed to determine the position of the red edge of the RR Lyrae gap with the chemical compositions (X,Z) = (0.7, 0.001) and (0.8, 0.001). The calculations are composed of the time integration of the conservation equations of mass, momentum, and energy in two spatial dimensions. The calculations allow time-dependent convection to be followed without either arbitrary assumptions regarding time dependence or the application of any theory of convection. The primary assumptions are the restriction to two spatial dimensions and that an ''eddy viscosity'' is employed to mimic the process of turbulent cascade and the conversion of convective kinetic energy into heat. The ability of time dependent convection to stabilize pulsation is shown, and the process by which this is achieved is discussed. The time dependence of convection is found to play a crucial role in the stabilization process. The dependence of the position of the red edge on helium abundance is examined. The results indicate that the color difference between the red and blue edges is a sensitive indicator of helium abundance. Comparison is made with certain globular cluster color differences which indicate that the helium abundance is close to 0.3 by weight

  20. VizieR Online Data Catalog: Standard Galactic field RR Lyrae. I. Photometry (Monson+, 2017)

    Science.gov (United States)

    Monson, A. J.; Beaton, R. L.; Scowcroft, V.; Freedman, W. L.; Madore, B. F.; Rich, J. A.; Seibert, M.; Kollmeier, J. A.; Clementini, G.

    2017-06-01

    The Three-hundred MilliMeter Telescope (TMMT) is a fully robotic, 300mm telescope at Las Campanas Observatory (LCO), for which the nightly operation and data processing have been completely automated. Over the course of two years data were collected on 179 individual nights for our sample of the 55 RR Lyrae in the B, V, and IC broadband filters. Of these nights, 76 were under photometric conditions and calibrated directly. The 103 nonphotometric nights were roughly calibrated by using the default transformation equations, but only provide differential photometry relative to the calibrated frames. This resulted in 59698 final individual observations. Individual data points have a typical photometric precision of 0.02mag. The statistical error falls rapidly with hundreds of observations, with the zero-point uncertainties being the largest source of uncertainty in the final reported mean magnitude. To compare the results of our TMMT campaign to previous studies of these RR Lyrae (RRL) and to fill gaps in our TMMT phase coverage, we have compiled available broadband data from literature published over the past 30 years and spanning our full wavelength coverage (0.4 to 4.5μm) from the optical to mid-infrared. We have homogenized these diverse data sets to the following filter systems: Johnson UBV, Kron-Cousins RI, 2MASS J,H,Ks, and Spitzer [3.6], [4.5]. The All Sky Automated Survey (ASAS; http://www.astrouw.edu.pl/asas/) is a long-term project monitoring all stars brighter than V~14mag. The program covers both hemispheres, with telescopes at Las Campanas Observatory in Chile and Haleakala on Maui, both of which provide simultaneous I and V photometry. The GEOS RR Lyr Survey (http://www.ast.obs-mip.fr/users/leborgne/dbRR/grrs.html) is a long-term program utilizing TAROT (http://tarot.obs-hp.fr/) at Calern Observatory (Nice University, France). Annual data releases from this project add times for maximum light for program stars over the last year of observations. In

  1. PERIOD–COLOR AND AMPLITUDE–COLOR RELATIONS AT MAXIMUM AND MINIMUM LIGHT FOR RR LYRAE STARS IN THE SDSS STRIPE 82 REGION

    Energy Technology Data Exchange (ETDEWEB)

    Ngeow, Chow-Choong [Graduate Institute of Astronomy, National Central University, Jhongli 32001, Taiwan (China); Kanbur, Shashi M.; Schrecengost, Zachariah [Department of Physics, SUNY Oswego, Oswego, NY 13126 (United States); Bhardwaj, Anupam; Singh, Harinder P. [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India)

    2017-01-10

    Investigation of period–color (PC) and amplitude–color (AC) relations at the maximum and minimum light can be used to probe the interaction of the hydrogen ionization front (HIF) with the photosphere and the radiation hydrodynamics of the outer envelopes of Cepheids and RR Lyraes. For example, theoretical calculations indicated that such interactions would occur at minimum light for RR Lyrae and result in a flatter PC relation. In the past, the PC and AC relations have been investigated by using either the ( V − R ){sub MACHO} or ( V − I ) colors. In this work, we extend previous work to other bands by analyzing the RR Lyraes in the Sloan Digital Sky Survey Stripe 82 Region. Multi-epoch data are available for RR Lyraes located within the footprint of the Stripe 82 Region in five ( ugriz ) bands. We present the PC and AC relations at maximum and minimum light in four colors: ( u − g ){sub 0}, ( g − r ){sub 0}, ( r − i ){sub 0}, and ( i − z ){sub 0}, after they are corrected for extinction. We found that the PC and AC relations for this sample of RR Lyraes show a complex nature in the form of flat, linear or quadratic relations. Furthermore, the PC relations at minimum light for fundamental mode RR Lyrae stars are separated according to the Oosterhoff type, especially in the ( g − r ){sub 0} and ( r − i ){sub 0} colors. If only considering the results from linear regressions, our results are quantitatively consistent with the theory of HIF-photosphere interaction for both fundamental and first overtone RR Lyraes.

  2. WEAK GALACTIC HALO-DWARF SPHEROIDAL CONNECTION FROM RR LYRAE STARS

    Energy Technology Data Exchange (ETDEWEB)

    Fiorentino, Giuliana [INAF-Osservatorio Astronomico di Bologna, via Ranzani 1, I-40127 Bologna (Italy); Bono, Giuseppe [Dipartimento di Fisica, Universitá di Roma Tor Vergata, Via della Ricerca Scientifica 1, I-00133 Roma (Italy); Monelli, Matteo; Gallart, Carme; Martínez-Vásquez, Clara E. [Instituto de Astrofísica de Canarias, Calle Via Lactea s/n, E-38205 La Laguna, Tenerife (Spain); Stetson, Peter B. [National Research Council, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Tolstoy, Eline [Kapteyn Astronomical Institute, University of Groningen, Postbus 800, 9700 AV Groningen (Netherlands); Salaris, Maurizio [Astrophysics Research Institute, Liverpool John Moores University IC2, Liverpool Science Park, 146 Brownlow Hill, Liverpool L35RF (United Kingdom); Bernard, Edouard J., E-mail: giuliana.fiorentino@oabo.inaf.it [SUPA, Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom)

    2015-01-01

    We discuss the role that dwarf galaxies may have played in the formation of the Galactic halo (Halo) using RR Lyrae stars (RRL) as tracers of their ancient stellar component. The comparison is performed using two observables (periods, luminosity amplitudes) that are reddening and distance independent. Fundamental mode RRL in 6 dwarf spheroidals (dSphs) and 11 ultra faint dwarf galaxies (∼1300) show a Gaussian period distribution well peaked around a mean period of (Pab) = 0.610 ± 0.001 days (σ = 0.03). The Halo RRL (∼15,000) are characterized by a broader period distribution. The fundamental mode RRL in all the dSphs apart from Sagittarius are completely lacking in High Amplitude Short Period (HASP) variables, defined as those having P ≲ 0.48 days and A{sub V} ≥ 0.75 mag. Such variables are not uncommon in the Halo and among the globular clusters and massive dwarf irregulars. To further interpret this evidence, we considered 18 globulars covering a broad range in metallicity (–2.3 ≲ [Fe/H] ≲ –1.1) and hosting more than 35 RRL each. The metallicity turns out to be the main parameter, since only globulars more metal-rich than [Fe/H] ∼ –1.5 host RRL in the HASP region. This finding suggests that dSphs similar to the surviving ones do not appear to be the major building-blocks of the Halo. Leading physical arguments suggest an extreme upper limit of ∼50% to their contribution. On the other hand, massive dwarfs hosting an old population with a broad metallicity distribution (Large Magellanic Cloud, Sagittarius) may have played a primary role in the formation of the Halo.

  3. ON THE RR LYRAE STARS IN GLOBULARS. IV. ω CENTAURI OPTICAL UBVRI PHOTOMETRY

    Energy Technology Data Exchange (ETDEWEB)

    Braga, V. F.; Bono, G.; Buonanno, R. [Department of Physics, Università di Roma Tor Vergata, via della Ricerca Scientifica 1, I-00133 Roma (Italy); Stetson, P. B. [NRC-Herzberg, Dominion Astrophysical Observatory, 5071 West Saanich Road, Victoria BC V9E 2E7 (Canada); Dall’Ora, M. [INAF-Osservatorio Astronomico di Capodimonte, Salita Moiariello 16, I-80131 Napoli (Italy); Ferraro, I.; Iannicola, G.; Castellani, M. [INAF-Osservatorio Astronomico di Roma, via Frascati 33, I-00040 Monte Porzio Catone (Italy); Fiorentino, G. [INAF-Osservatorio Astronomico di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); Freyhammer, L. M. [Jeremiah Horrocks Institute of Astrophysics, University of Central Lancashire, Preston PR1 2HE (United Kingdom); Marengo, M.; Neeley, J. [Department of Physics and Astronomy, Iowa State University, Ames, IA 50011 (United States); Valenti, E. [European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching bei Munchen (Germany); Calamida, A. [National Optical Astronomy Observatory, 950 N Cherry Avenue, Tucson, AZ 85719 (United States); Da Silva, R.; Fabrizio, M.; Giuffrida, G. [ASDC, via del Politecnico snc, I-00133 Roma (Italy); Degl’Innocenti, S. [INFN, Sezione di Pisa, Largo Pontecorvo 3, I-56127, Pisa (Italy); Di Cecco, A. [INAF-Osservatorio Astronomico di Teramo, Via Mentore Maggini snc, Loc. Collurania, I-64100 Teramo (Italy); Freedman, W. L. [Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); and others

    2016-12-01

    New accurate and homogeneous optical UBVRI photometry has been obtained for variable stars in the Galactic globular cluster ω Cen (NGC 5139). We secured 8202 CCD images covering a time interval of 24 years and a sky area of 84 × 48 arcmin. The current data were complemented with data available in the literature and provided new, homogeneous pulsation parameters (mean magnitudes, luminosity amplitudes, periods) for 187 candidate ω Cen RR Lyrae (RRLs). Among them we have 101 RRc (first overtone) and 85 RRab (fundamental) variables, and a single candidate RRd (double-mode) variable. Candidate Blazhko RRLs show periods and colors that are intermediate between the RRc and RRab variables, suggesting that they are transitional objects. A comparison of the period distribution and the Bailey diagram indicates that RRLs in ω Cen show a long-period tail not present in typical Oosterhoff II (OoII) globulars. The RRLs in dwarf spheroidals and in ultra-faint dwarfs have properties between Oosterhoff intermediate and OoII clusters. Metallicity plays a key role in shaping the above evidence. These findings do not support the hypothesis that ω Cen is the core remnant of a spoiled dwarf galaxy. Using optical period–Wesenheit relations that are reddening-free and minimally dependent on metallicity we find a mean distance to ω Cen of 13.71 ± 0.08 ± 0.01 mag (semi-empirical and theoretical calibrations). Finally, we invert the I -band period–luminosity–metallicity relation to estimate individual RRLs’ metal abundances. The metallicity distribution agrees quite well with spectroscopic and photometric metallicity estimates available in the literature.

  4. RR Lyrae stars in and around NGC 6441: signatures of dissolving cluster stars

    Science.gov (United States)

    Kunder, Andrea

    2018-06-01

    Detailed elemental abundance patterns of metal-poor ([Fe/H]~ -1 dex) stars in the Galactic bulge indicate that a number of them are consistent with globular cluster (GC) stars and may be former members of dissolved GCs. This would indicate that a few per cent of the Galactic bulge was built up from destruction and/or evaporation of globular clusters. Here an attempt is made to identify such presumptive destroyed stars originating from the massive, inner Galaxy globular cluster NGC~6441 using its rich RR Lyrae variable star (RRL) population. We present radial velocities of forty RRLs centered on the globular cluster NGC~6441. All of the 13 RRLs observed within the cluster tidal radius have velocities consistent with cluster membership, with an average radial velocity of 24 +- 5~km/s and a star-to-star scatter of 11~km/s. This includes two new RRLs that were previously not associated with the cluster. Eight RRLs with radial velocities consistent with cluster membership but up to three time the distance from the tidal radius are also reported. These potential extra-tidal RRLs also have exceptionally long periods, which is a curious characteristic of the NGC~6441 RRL population that hosts RRLs with periods longer than seen anywhere else in the Milky Way. As expected of stripped cluster stars, most are inline with the cluster's orbit. Therefore, either the tidal radius of NGC~6441 is underestimated and/or we are seeing dissolving cluster stars stemming from NGC~6441 that are building up the old spheroidal bulge. Both the mean velocity of the cluster as well as the underlying field population is consistent with belonging to an old spheroidal bulge with low rotation and high velocity dispersion that formed before the bar.

  5. Metal-rich RRc Stars in the Carnegie RR Lyrae Survey

    Science.gov (United States)

    Sneden, Christopher; Preston, George W.; Kollmeier, Juna A.; Crane, Jeffrey D.; Morrell, Nidia; Prieto, José L.; Shectman, Stephen A.; Skowron, Dorota M.; Thompson, Ian B.

    2018-01-01

    We describe and employ a stacking procedure to investigate abundances derived from the low signal-to-noise ratio spectra obtained in the Carnegie RR Lyrae Survey (CARRS). We find iron metallicities that extend from [Fe/H] ∼ ‑2.5 to values at least as large as [Fe/H] ∼ ‑0.5 in the 274-spectrum CARRS RRc data set. We consider RRc sample contamination by high amplitude solar metallicity δ Scuti stars (HADS) at periods less than 0.3 days, where photometric discrimination between RRc and δ Scuti stars has proven to be problematic. We offer a spectroscopic discriminant, the well-marked overabundance of heavy elements, principally [Ba/H], that is a common, if not universal, characteristic of HADS of all periods and axial rotations. No bona fide RRc stars known to us have verified heavy-element overabundances. Three out of 34 stars in our sample with [Fe/H] > ‑0.7 exhibit anomalously strong features of Sr, Y, Zr, Ba, and many rare earths. However, carbon is not enhanced in these three stars, and we conclude that their elevated n-capture abundances have not been generated in interior neutron-capture nucleosynthesis. Contamination by HADS appears to be unimportant, and metal-rich RRc stars occur in approximately the same proportion in the Galactic field as do metal-rich RRab stars. An apparent dearth of metal-rich RRc is probably a statistical fluke. Finally, we show that RRc stars have a similar inverse period–metallicity relationship as has been found for RRab stars.

  6. ON A NEW THEORETICAL FRAMEWORK FOR RR LYRAE STARS. I. THE METALLICITY DEPENDENCE

    International Nuclear Information System (INIS)

    Marconi, M.; Coppola, G.; Musella, I.; Ripepi, V.; Bono, G.; Braga, V.; Buonanno, R.; Pietrinferni, A.; Castellani, M.; Stellingwerf, R. F.

    2015-01-01

    We present new nonlinear, time-dependent convective hydrodynamical models of RR Lyrae stars computed assuming a constant helium-to-metal enrichment ratio and a broad range in metal abundances (Z = 0.0001–0.02). The stellar masses and luminosities adopted to construct the pulsation models were fixed according to detailed central He-burning horizontal-branch evolutionary models. The pulsation models cover a broad range in stellar luminosity and effective temperatures and the modal stability is investigated for both fundamental (FU) and first overtone polsators (FOs). We predict the topology of the instability strip (IS) as a function of the metal content and new analytical relations for the edges of the IS in the observational plane. Moreover, a new analytical relation to constrain the pulsation mass of double pulsators as a function of the period ratio and the metal content is provided. We derive new Period–Radius–Metallicity relations for FU and FO pulsators. They agree quite well with similar empirical and theoretical relations in the literature. From the predicted bolometric light curves, transformed into optical (UBVRI) and near-infrared (NIR; JHK) bands, we compute the intensity-averaged mean magnitudes along the entire pulsation cycle and in turn new and homogenous metal-dependent (RIJHK) Period–Luminosity relations. Moreover, we compute new dual and triple-band optical, optical–NIR, and NIR Period–Wesenheit–Metallicity relations. Interestingly, we find that the optical Period-W(V, B–V) is independent of the metal content and that the accuracy of individual distances is a balance between the adopted diagnostics and the precision of photometric and spectroscopic data sets

  7. The occurrence of Binary Evolution Pulsators in the classical instability strip of RR Lyrae and Cepheid variables

    OpenAIRE

    Karczmarek, P.; Wiktorowicz, G.; Iłkiewicz, K.; Smolec, R.; Stępień, K.; Pietrzyński, G.; Gieren, W.; Belczynski, K.

    2016-01-01

    Single star evolution does not allow extremely low-mass stars to cross the classical instability strip (IS) during the Hubble time. However, within binary evolution framework low-mass stars can appear inside the IS once the mass transfer (MT) is taken into account. Triggered by a discovery of low-mass 0.26 Msun RR Lyrae-like variable in a binary system, OGLE-BLG-RRLYR-02792, we investigate the occurrence of similar binary components in the IS, which set up a new class of low-mass pulsators. T...

  8. Variaciones seculares de período en las RR Lyrae de ω~Centauri

    Science.gov (United States)

    Marraco, H. G.; Milesi, G. E.

    Utilizando 689 observaciones de 35 estrellas RR Lyrae del cúmulo globular ω Centauri hemos obtenido nuevas determinaciones de sus períodos y sus correspondientes variaciones seculares. Las observaciones fueron obtenidas de la literatura con la excepción de un grupo 66 determinaciones que se presentan por vez primera aquí. Utilizando el parámetro testigo σ descripto en Marraco & Muzzio (Publ. Astron. Soc. Pacific 92, 700, 1980), hemos realizado un ajuste bidimensional en P y β (donde β es la variación secular del período). Con este fin la totalidad de las 689 observaciones fueron llevadas a un sistema fotométrico común. Para esto se realizó un cuidadoso análisis de los numerosos errores en la identificación de las estrellas de las series de comparación. Los resultados de los ajustes bidimensionales fueron analizados utilizando técnicas de procesamiento de imágenes. Con este fin el parámetro de ajuste σ fue representado como función de P y β. En las imágenes resultantes se buscaron los mínimos y al menor de ellos se lo aceptó como período instantáneo verdadero y su variación secular β. La determinación precisa de cada parámetro se realizó mediante ajuste de gaussianas y se determinaron sus errores. A modo de ejemplo la variable #8 fue analizada en una matriz de 501 × 501 elementos representando el parámetro σ para valores comprendidos entre 0,521034 son P = 0,5212859±0,0000001 días y β 14,012±,010×10-10 días/día respectivamente. Con estos valores el parámetro testigo resulta σ= 0,127 . Si no se tiene en cuenta la variación secular del período y se busca aquél de mejor ajuste para β = 0, se obtiene P = 0,5212960 días, pero entonces el parámetro de ajuste resulta tan alto como σ = 0,23 .

  9. TIME-SERIES PHOTOMETRY OF GLOBULAR CLUSTERS: M62 (NGC 6266), THE MOST RR LYRAE-RICH GLOBULAR CLUSTER IN THE GALAXY?

    International Nuclear Information System (INIS)

    Contreras, R.; Catelan, M.; Smith, H. A.; Kuehn, C. A.; Pritzl, B. J.; Borissova, J.

    2010-01-01

    We present new time-series CCD photometry, in the B and V bands, for the moderately metal-rich ([Fe/H] ≅ -1.3) Galactic globular cluster M62 (NGC 6266). The present data set is the largest obtained so far for this cluster and consists of 168 images per filter, obtained with the Warsaw 1.3 m telescope at the Las Campanas Observatory and the 1.3 m telescope of the Cerro Tololo Inter-American Observatory, in two separate runs over the time span of 3 months. The procedure adopted to detect the variable stars was the optimal image subtraction method (ISIS v2.2), as implemented by Alard. The photometry was performed using both ISIS and Stetson's DAOPHOT/ALLFRAME package. We have identified 245 variable stars in the cluster fields that have been analyzed so far, of which 179 are new discoveries. Of these variables, 133 are fundamental mode RR Lyrae stars (RRab), 76 are first overtone (RRc) pulsators, 4 are type II Cepheids, 25 are long-period variables (LPVs), 1 is an eclipsing binary, and 6 are not yet well classified. Such a large number of RR Lyrae stars places M62 among the top two most RR Lyrae-rich (in the sense of total number of RR Lyrae stars present) globular clusters known in the Galaxy, second only to M3 (NGC 5272) with a total of 230 known RR Lyrae stars. Since this study covers most but not all of the cluster area, it is not unlikely that M62 is in fact the most RR Lyrae-rich globular cluster in the Galaxy. In like vein, thanks to the time coverage of our data sets, we were also able to detect the largest sample of LPVs known so far in a Galactic globular cluster. We analyze a variety of Oosterhoff type indicators for the cluster, including mean periods, period distribution, Bailey diagrams, and Fourier decomposition parameters (as well as the physical parameters derived therefrom). All of these indicators clearly show that M62 is an Oosterhoff type I system. This is in good agreement with the moderately high metallicity of the cluster, in spite of its

  10. The complex case of V445 Lyr observed with Kepler: two Blazhko modulations, a non-radial mode, possible triple mode RR Lyrae pulsation, and more

    DEFF Research Database (Denmark)

    Guggenberger, E.; Kolenberg, K.; Nemec, J. M.

    2012-01-01

    Rapid and strong changes in the Blazhko modulation of RR Lyrae stars, as they have recently been detected in high precision satellite data, have become a crucial topic in finding an explanation of the long-standing mystery of the Blazhko effect. We present here an analysis of the most extreme cas...

  11. A Data-driven Study of RR Lyrae Near-IR Light Curves: Principal Component Analysis, Robust Fits, and Metallicity Estimates

    Science.gov (United States)

    Hajdu, Gergely; Dékány, István; Catelan, Márcio; Grebel, Eva K.; Jurcsik, Johanna

    2018-04-01

    RR Lyrae variables are widely used tracers of Galactic halo structure and kinematics, but they can also serve to constrain the distribution of the old stellar population in the Galactic bulge. With the aim of improving their near-infrared photometric characterization, we investigate their near-infrared light curves, as well as the empirical relationships between their light curve and metallicities using machine learning methods. We introduce a new, robust method for the estimation of the light-curve shapes, hence the average magnitudes of RR Lyrae variables in the K S band, by utilizing the first few principal components (PCs) as basis vectors, obtained from the PC analysis of a training set of light curves. Furthermore, we use the amplitudes of these PCs to predict the light-curve shape of each star in the J-band, allowing us to precisely determine their average magnitudes (hence colors), even in cases where only one J measurement is available. Finally, we demonstrate that the K S-band light-curve parameters of RR Lyrae variables, together with the period, allow the estimation of the metallicity of individual stars with an accuracy of ∼0.2–0.25 dex, providing valuable chemical information about old stellar populations bearing RR Lyrae variables. The methods presented here can be straightforwardly adopted for other classes of variable stars, bands, or for the estimation of other physical quantities.

  12. Pulsations and period changes of the non-Blazhko RR lyrae variable Y oct observed from Dome A, Antarctica

    Energy Technology Data Exchange (ETDEWEB)

    Zhihua, Huang; Jianning, Fu; Weikai, Zong; Lingzhi, Wang; Zonghong, Zhu [Department of Astronomy, Beijing Normal University, Beijing 100875 (China); M, Macri Lucas; Lifan, Wang [Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A and M University, College Station, TX (United States); Ashley, Michael C. B.; S, Lawrence Jon; Daniel, Luong-Van [School of Physics, University of New South Wales, NSW (Australia); Xiangqun, Cui; Long-Long, Feng; Xuefei, Gong; Qiang, Liu; Huigen, Yang; Xiangyan, Yuan; Xu, Zhou; Zhenxi, Zhu [Chinese Center for Antarctic Astronomy, Nanjing (China); R, Pennypacker Carl [Center for Astrophysics, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); G, York Donald, E-mail: jnfu@bnu.edu.cn [Department of Astronomy and Astrophysics and Enrico Fermi Institute, University of Chicago, Chicago, IL (United States)

    2015-01-01

    During the operation of the Chinese Small Telescope Array (CSTAR) in Dome A of Antarctica in the years 2008, 2009, and 2010, large amounts of photometric data have been obtained for variable stars in the CSTAR field. We present here the study of one of six RR Lyrae variables, Y Oct, observed with CSTAR in Dome A, Antarctica. Photometric data in the i band were obtained in 2008 and 2010, with a duty cycle (defined as the fraction of time representing scientifically available data to CSTAR observation time) of about 44% and 52%, respectively. In 2009, photometric data in the g and r bands were gathered for this star, with a duty cycle of 65% and 60%, respectively. Fourier analysis of the data in the three bands only shows the fundamental frequency and its harmonics, which is characteristic of the non-Blazhko RR Lyrae variables. Values of the fundamental frequency and the amplitudes, as well as the total pulsation amplitude, are obtained from the data in the three bands separately. The amplitude of the fundamental frequency and the total pulsation amplitude in the g band are the largest, and those in the i band the smallest. Two-hundred fifty-one times of maximum are obtained from the three seasons of data, which are analyzed together with 38 maximum times provided in the GEOS RR Lyrae database. A period change rate of −0.96 ± 0.07 days Myr{sup −1} is then obtained, which is a surprisingly large negative value. Based on relations available in the literature, the following physical parameters are derived: [Fe/H] = −1.41 ± 0.14, M{sub V} = 0.696 ± 0.014 mag, V−K = 1.182 ± 0.028 mag, logT{sub eff} = 3.802 ± 0.003 K, logg = 2.705 ± 0.004, logL/L{sub ⊙} = 1.625 ± 0.013, and logM/M{sub ⊙} = −0.240 ± 0.019.

  13. Metal Abundances, Radial Velocities, and Other Physical Characteristics for the RR Lyrae Stars in The Kepler Field

    Science.gov (United States)

    Nemec, James M.; Cohen, Judith G.; Ripepi, Vincenzo; Derekas, Aliz; Moskalik, Pawel; Sesar, Branimir; Chadid, Merieme; Bruntt, Hans

    2013-08-01

    Spectroscopic iron-to-hydrogen ratios, radial velocities, atmospheric parameters, and new photometric analyses are presented for 41 RR Lyrae stars (and one probable high-amplitude δ Sct star) located in the field-of-view of the Kepler space telescope. Thirty-seven of the RR Lyrae stars are fundamental-mode pulsators (i.e., RRab stars) of which sixteen exhibit the Blazhko effect. Four of the stars are multiperiodic RRc pulsators oscillating primarily in the first-overtone mode. Spectroscopic [Fe/H] values for the 34 stars for which we were able to derive estimates range from -2.54 ± 0.13 (NR Lyr) to -0.05 ± 0.13 dex (V784 Cyg), and for the 19 Kepler-field non-Blazhko stars studied by Nemec et al. the abundances agree will with their photometric [Fe/H] values. Four non-Blazhko RR Lyrae stars that they identified as metal-rich (KIC 6100702, V2470 Cyg, V782 Cyg and V784 Cyg) are confirmed as such, and four additional stars (V839 Cyg, KIC 5520878, KIC 8832417, KIC 3868420) are also shown here to be metal-rich. Five of the non-Blazhko RRab stars are found to be more metal-rich than [Fe/H] ~-0.9 dex while all of the 16 Blazhko stars are more metal-poor than this value. New P-\\phi _31^s-[Fe/H] relationships are derived based on ~970 days of quasi-continuous high-precision Q0-Q11 long- and short-cadence Kepler photometry. With the exception of some Blazhko stars, the spectroscopic and photometric [Fe/H] values are in good agreement. Several stars with unique photometric characteristics are identified, including a Blazhko variable with the smallest known amplitude and frequency modulations (V838 Cyg). Based in part on observations made at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Keck Observatory was made possible by the generous financial support of the W.M. Keck Foundation. Also, based in part on

  14. VizieR Online Data Catalog: CTIO/DECam photometry of RR Lyrae stars in M5 (Vivas+, 2017)

    Science.gov (United States)

    Vivas, A. K.; Saha, A.; Olsen, K.; Blum, R.; Olszewski, E. W.; Claver, J.; Valdes, F.; Axelrod, T.; Kaleida, C.; Kunder, A.; Narayan, G.; Matheson, T.; Walker, A.

    2017-11-01

    Observations were obtained during 2013 (2013 Jun 7-9, and 2013 Jun 21) and 2014 (2014 Mar 7-9) with the Dark Energy Camera (DECam) imager on the 4m Blanco Telescope at Cerro Tololo Inter-American Observatory (CTIO), Chile. Repeated DECam images of a field centered on M5 (R.A.=15:18:33.2, decl.=+02:04:51.7, J2000.0) were obtained using the u,g,r,i, and z filters. The large field of view (FOV) of DECam (2.2°) easily covers the whole globular cluster with only the central CCDs of the camera. A total of 66 RR Lyrae stars and 1 SX Phe were recognized in the field of M5. The individual measurements for the periodic variable stars are provided in Table2. In Table3, we present the list of periodic variable stars. (3 data files).

  15. High-precision 2MASS JHK{sub s} light curves and other data for RR Lyrae star SDSS J015450 + 001501: Strong constraints for nonlinear pulsation models

    Energy Technology Data Exchange (ETDEWEB)

    Szabó, Róbert; Ivezić, Željko; Kiss, László L.; Kolláth, Zoltán [Konkoly Observatory, MTA CSFK, Konkoly Thege Miklós út 15-17, H-1121 Budapest (Hungary); Jones, Lynne; Becker, Andrew C.; Davenport, James R. A. [Astronomy Department, University of Washington, Box 351580, Seattle, WA 98195-1580 (United States); Sesar, Branimir [Division of Physics, Mathematics and Astronomy, Caltech, Pasadena, CA 91125 (United States); Cutri, Roc M., E-mail: rszabo@konkoly.hu [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States)

    2014-01-01

    We present and discuss an extensive data set for the non-Blazhko ab-type RR Lyrae star SDSS J015450+001501, including optical Sloan Digital Sky Survey ugriz light curves and spectroscopic data, LINEAR and Catalina Sky Survey unfiltered optical light curves, and infrared Two Micron All Sky Survey (2MASS) JHK{sub s} and Wide-field Infrared Survey Explorer W1 and W2 light curves. Most notable is that light curves obtained by 2MASS include close to 9000 photometric measures collected over 3.3 yr and provide an exceedingly precise view of near-infrared variability. These data demonstrate that static atmosphere models are insufficient to explain multiband photometric light-curve behavior and present strong constraints for nonlinear pulsation models for RR Lyrae stars. It is a challenge to modelers to produce theoretical light curves that can explain data presented here, which we make publicly available.

  16. Theoretical red edge of the RR Lyrae Gap. II. Dependence of the red edge on luminosity and composition, and observational consequences

    International Nuclear Information System (INIS)

    Deupree, R.G.

    1977-01-01

    The theoretical location of the red edge of the RR Lyrae Gap is computed for two luminosities and two compositions. An increase in luminosity or an increase in helium abundance decreases the effective temperature of the red edge. A comparison of the width of the instability strip with observations indicates that Yapprox. =0.3. The effects of convection on the light curves, velocity curves, pulsation periods, and overall structure of the models are small

  17. EPIC 201585823, a rare triple-mode RR Lyrae star discovered in K2 mission data

    DEFF Research Database (Denmark)

    Kurtz, Donald W.; Bowman, Dominic M.; Ebo, Simon J.

    2016-01-01

    We have discovered a new, rare triple-mode RR Lyr star, EPIC 201585823, in the Kepler K2 mission Campaign 1 data. This star pulsates primarily in the fundamental and first-overtone radial modes, and, in addition, a third non-radial mode. The ratio of the period of the non-radial mode...... pixels with significant signal for the star, but without correction for pointing changes, is best for frequency analysis of this star, and, by implication, other RR Lyr stars observed by the K2 mission. We compare several pipeline reductions of the K2 mission data for this star....

  18. The Araucaria Project: The Distance to the Fornax Dwarf Galaxy from Near-infrared Photometry of RR Lyrae Stars

    Science.gov (United States)

    Karczmarek, Paulina; Pietrzyński, Grzegorz; Górski, Marek; Gieren, Wolfgang; Bersier, David

    2017-12-01

    We have obtained single-phase near-infrared (NIR) magnitudes in the J and K bands for 77 RR Lyrae (RRL) stars in the Fornax Dwarf Spheroidal Galaxy. We have used different theoretical and empirical NIR period-luminosity-metallicity calibrations for RRL stars to derive their absolute magnitudes, and found a true, reddening-corrected distance modulus of 20.818+/- 0.015{{(statistical)}}+/- 0.116{{(systematic)}} mag. This value is in excellent agreement with the results obtained within the Araucaria Project from the NIR photometry of red clump stars (20.858 ± 0.013 mag), the tip of the red giant branch (20.84+/- 0.04+/- 0.14 mag), as well as with other independent distance determinations to this galaxy. The effect of metallicity and reddening is substantially reduced in the NIR domain, making this method a robust tool for accurate distance determination at the 5% level. This precision is expected to reach the level of 3% once the zero points of distance calibrations are refined thanks to the Gaia mission. NIR period-luminosity-metallicity relations of RRL stars are particularly useful for distance determinations to galaxies and globular clusters up to 300 kpc, that lack young standard candles, like Cepheids. Based on data collected with the VLT/HAWK-I instrument at ESO Paranal Observatory, Chile, as a part of programme 082.D-0123(B).

  19. VizieR Online Data Catalog: RR Lyrae stars from the PS1 3π survey (Sesar+, 2017)

    Science.gov (United States)

    Sesar, B.; Hernitschek, N.; Mitrovic, S.; Ivezic, Z.; Rix, H.-W.; Cohen, J. G.; Bernard, E. J.; Grebel, E. K.; Martin, N. F.; Schlafly, E. F.; Burgett, W. S.; Draper, P. W.; Flewelling, H.; Kaiser, N.; Kudritzki, R. P.; Magnier, E. A.; Metcalfe, N.; Tonry, J. L.; Waters, C.

    2018-04-01

    Building on the work by Hernitschek+ (2016, J/ApJ/817/73), in this paper, we use the final PS1 data release (PV3) to significantly increase the completeness and purity of the PS1 sample of RR Lyrae stars. Pan-STARRS1 (PS1; Kaiser+ 2010, see II/349) is a wide-field optical/near-IR survey telescope system located at the Haleakala Observatory on the island of Maui in Hawai'i. The largest survey undertaken by the telescope, the PS1 3π survey (Chambers K.C. 2011, BAAS, 43, 113.01), has observed the entire sky north of decl. -30° in five filter bands, reaching 5σ single-epoch depths of about 22.0, 22.0, 21.9, 21.0, and 19.8mag in gP1, rP1, iP1, zP1, and yP1 bands, respectively. The uncertainty in photometric calibration of the survey is <~0.01mag, and the astrometric precision of single-epoch detections is 10mas. (4 data files).

  20. The Milky Way's Circular Velocity Curve and Its Constraint on the Galactic Mass with RR Lyrae Stars

    Energy Technology Data Exchange (ETDEWEB)

    Ablimit, Iminhaji; Zhao, Gang, E-mail: iminhaji@nao.cas.cn, E-mail: gzhao@nao.cas.cn [Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

    2017-09-01

    We present a sample of 1148 ab-type RR Lyrae (RRLab) variables identified from Catalina Surveys Data Release 1, combined with SDSS DR8 and LAMOST DR4 spectral data. We first use a large sample of 860 Galactic halo RRLab stars and derive the circular velocity distributions for the stellar halo. With the precise distances and carefully determined radial velocities (the center-of-mass radial velocities) and by considering the pulsation of the RRLab stars in our sample, we can obtain a reliable and comparable stellar halo circular velocity curve. We follow two different prescriptions for the velocity anisotropy parameter β in the Jeans equation to study the circular velocity curve and mass profile. Additionally, we test two different solar peculiar motions in our calculation. The best result we obtained with the adopted solar peculiar motion 1 of ( U , V , W ) = (11.1, 12, 7.2) km s{sup −1} is that the enclosed mass of the Milky Way within 50 kpc is (3.75 ± 1.33) × 10{sup 11} M {sub ⊙} based on β = 0 and the circular velocity 180 ± 31.92 (km s{sup −1}) at 50 kpc. This result is consistent with dynamical model results, and it is also comparable to the results of previous similar works.

  1. THE ARAUCARIA PROJECT: THE DISTANCE TO THE CARINA DWARF GALAXY FROM INFRARED PHOTOMETRY OF RR LYRAE STARS

    Energy Technology Data Exchange (ETDEWEB)

    Karczmarek, Paulina; Pietrzynski, Grzegorz; Suchomska, Ksenia; Konorski, Piotr; Górski, Marek; Pilecki, Bogumił; Wielgórski, Piotr [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478, Warsaw (Poland); Gieren, Wolfgang; Graczyk, Dariusz, E-mail: pkarczmarek@astrouw.edu.pl, E-mail: ksenia@astrouw.edu.pl, E-mail: piokon@astrouw.edu.pl, E-mail: pilecki@astrouw.edu.pl, E-mail: pwielgorski@astrouw.edu.pl, E-mail: pietrzyn@astrouw.edu.pl, E-mail: wgieren@astro-udec.cl, E-mail: mgorski@astrouw.edu.pl, E-mail: darek@astro-udec.cl [Universidad de Concepción, Departamento de Astronomia, Casilla 160-C, Concepción (Chile)

    2015-09-15

    We obtained single-phase near-infrared (NIR) magnitudes in the J- and K-band for a sample of 33 RR Lyrae (RRL) stars in the Carina dSph galaxy. Applying different theoretical and empirical calibrations of the NIR period–luminosity–metallicity relation for RRL stars, we find consistent results and obtain a true, reddening-corrected distance modulus of 20.118 ± 0.017 (statistical) ± 0.11 (systematic) mag. This value is in excellent agreement with the results obtained in the context of the Araucaria Project from NIR photometry of red clump stars (20.165 ± 0.015) and the tip of red giant branch (20.09 ± 0.03 ± 0.12 mag in the J band, 20.14 ± 0.04 ± 0.14 mag in the K band), as well as with most independent distance determinations to this galaxy. The NIR RRL method proved to be a reliable tool for accurate distance determination at the 5% level or better, particularly for galaxies and globular clusters that lack young standard candles, like Cepheids.

  2. Identification and period investigation of pulsation variable star UY Camelopardalis, an RR Lyrae star in binary system

    Science.gov (United States)

    Li, Lin-Jia; Qian, Sheng-Bang; Voloshina, Irina; Metlov, Vladimir G.; Zhu, Li-Ying; Liao, Wen-Ping

    2018-06-01

    We present photometric measurements of the short period variable star UY Cam, which has been classified as a δ Scuti or c-type RR Lyrae (RRc) variable in different catalogs. Based on the analyses on Fourier coefficients and (NUV - V)0, we find that UY Cam is probably an RRc star. We obtain 58 new times of light maximum for UY Cam based on several sky surveys and our observations. Combining these with the times of light maximum in literature, a total of 154 times of light maximum are used to analyze the O - C diagram of UY Cam. The results show that the O - C pattern can be described by a downward parabolic component with a rate of -6.86 ± 0.47 × 10-11 d d-1, and a cyclic variation with a period of 65.7 ± 2.4 yr. We suppose these components are caused by the stellar evolution and the light travel time effect (LiTE) of a companion in elliptical orbit, respectively. By calculation, the minimum mass of the potential companion is about 0.17 M⊙, and its mass should be less than or equal to the pulsation primary star when the inclination i > 22.5°D. Therefore, the companion should be a low-mass star, like a late-type main-sequence star or a white dwarf. Due to the unique property of UY Cam, we suggest that more observations and studies on UY Cam and other RRc stars are needed to check the nature of these stars, including the pulsations and binarities.

  3. Evidence for Distinct Components of the Galactic Stellar Halo from 838 RR Lyrae Stars Discovered in the LONEOS-I Survey

    Energy Technology Data Exchange (ETDEWEB)

    Miceli, A; Rest, A; Stubbs, C W; Hawley, S L; Cook, K H; Magnier, E A; Krisciunas, K; Bowell, E; Koehn, B

    2007-02-23

    We present 838 ab-type RR Lyrae stars from the Lowell Observatory Near Earth Objects Survey Phase I (LONEOS-I). These objects cover 1430 deg{sup 2} and span distances ranging from 3-30kpc from the Galactic Center. Object selection is based on phased, photometric data with 28-50 epochs. We use this large sample to explore the bulk properties of the stellar halo, including the spatial distribution. The period-amplitude distribution of this sample shows that the majority of these RR Lyrae stars resemble Oosterhoff type I, but there is a significant fraction (26%) which have longer periods and appear to be Oosterhoff type II. We find that the radial distributions of these two populations have significantly different profiles ({rho}{sub OoI} {approx} R{sup -2.26{+-}0.07} and {rho}{sub OoII} {approx} R{sup -2.88{+-}0.11}). This suggests that the stellar halo was formed by at least two distinct accretion processes and supports dual-halo models.

  4. The Distance to M54 using Infrared Photometry of RR Lyrae Variable Stars and the Implications of its Relation to the Sagittarius Dwarf Galaxy

    Science.gov (United States)

    Gupta, Arvind F.; Beaton, Rachael L.; Majewski, Steven R.; SMHASH Team

    2018-01-01

    CDM cosmological models predict that dark matter halo density profiles will have central cusps. Yet for many dwarf spheroidal galaxies (dSphs), this expectation is in contrast with observations of cored, rather than cusped, halos. This 'cusp-core problem' is apparent in the Sagittarius Dwarf Galaxy (Sgr), one of the largest satellites of the Milky Way. The globular cluster M54, one of several clusters associated with Sgr, coincides in on-sky position with the center of the main body of Sgr. While several studies find that M54 lies within the center of Sgr, other findings show that M54 is offset from the center by several kiloparsecs along our line of sight. The latter requires Sgr to have a cored dark matter distribution. In the presence of a cuspy halo, the orbit of M54 would have decayed via dynamical friction and the cluster would have fallen to the center of Sgr. A clear determination of the relation of the two bodies may help us better understand the distribution of dark matter in Sgr and other dSphs. Here we present a measurement of the distance modulus to M54 using a set of RR Lyrae variable stars in near-infrared Magellan data mid-infrared Spitzer data. The magnitudes of individual stars are measured using multi-epoch PSF photometry and light curve fitting. From precise RR Lyrae period-luminosity relations at these wavelengths, we then find the mean M54 distance modulus to be 17.126 ± 0.023 (ran) ± 0.080 (sys). Our result is consistent with a distance measurement to Sgr derived via nearly identical methods and thus also consistent with the expectation of a central cusp in the dark matter density profile of Sgr.

  5. VizieR Online Data Catalog: The distance modulus of the LMC (Kovacs, 2000)

    Science.gov (United States)

    Kovacs, G.

    2000-11-01

    This table provides periods, intensity averaged V magnitudes and magnitude averaged V-Rc (Johnson V & Kron-Cousins R) colors of the MACHO LMC double-mode RR Lyrae variables employed in the above paper. For the calculation of the averages, an iterative 3-sigma condition was used to omit outliers. Further references (coordinates, amplitude ratios, etc.) to these variables can be found in Alcock et al. (1997ApJ...482...89A) and in Alcock et al. (2000, Cat. ). Trasformation to the standard system has been performed in accordance with Alcock et al. (1999PASP..111.1539A). (1 data file).

  6. A Near-infrared RR Lyrae Census along the Southern Galactic Plane: The Milky Way’s Stellar Fossil Brought to Light

    Science.gov (United States)

    Dékány, István; Hajdu, Gergely; Grebel, Eva K.; Catelan, Márcio; Elorrieta, Felipe; Eyheramendy, Susana; Majaess, Daniel; Jordán, Andrés

    2018-04-01

    RR Lyrae stars (RRLs) are tracers of the Milky Way’s fossil record, holding valuable information on its formation and early evolution. Owing to the high interstellar extinction endemic to the Galactic plane, distant RRLs lying at low Galactic latitudes have been elusive. We attained a census of 1892 high-confidence RRLs by exploiting the near-infrared photometric database of the VVV survey’s disk footprint spanning ∼70° of Galactic longitude, using a machine-learned classifier. Novel data-driven methods were employed to accurately characterize their spatial distribution using sparsely sampled multi-band photometry. The RRL metallicity distribution function (MDF) was derived from their K s -band light-curve parameters using machine-learning methods. The MDF shows remarkable structural similarities to both the spectroscopic MDF of red clump giants and the MDF of bulge RRLs. We model the MDF with a multi-component density distribution and find that the number density of stars associated with the different model components systematically changes with both the Galactocentric radius and vertical distance from the Galactic plane, equivalent to weak metallicity gradients. Based on the consistency with results from the ARGOS survey, three MDF modes are attributed to the old disk populations, while the most metal-poor RRLs are probably halo interlopers. We propose that the dominant [Fe/H] component with a mean of ‑1 dex might correspond to the outskirts of an ancient Galactic spheroid or classical bulge component residing in the central Milky Way. The physical origins of the RRLs in this study need to be verified by kinematical information.

  7. On a New Theoretical Framework for RR Lyrae Stars. II. Mid-infrared Period–Luminosity–Metallicity Relations

    Energy Technology Data Exchange (ETDEWEB)

    Neeley, Jillian R.; Marengo, Massimo; Trueba, Nicolas [Department of Physics and Astronomy, Iowa State University, Ames, IA 50011 (United States); Bono, Giuseppe; Braga, Vittorio F.; Magurno, Davide [Department of Physics, Università di Roma Tor Vergara, via della Ricerca Scientifica 1, I-00133 Roma (Italy); Dall’Ora, Massimo; Marconi, Marcella [INAF-Osservatorio Astronomico di Capodimonte, Salita Moiarello 16, I-80131 Napoli (Italy); Tognelli, Emanuele; Moroni, Pier G. Prada [Dipartimento di Fisica, Università di Pisa, Lago Bruno Pontecorvo 3, I-56127, Pisa (Italy); Beaton, Rachael L.; Madore, Barry F.; Seibert, Mark [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Freedman, Wendy L. [Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States); Monson, Andrew J. [Department of Astronomy and Astrophysics, The Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Scowcroft, Victoria [Department of Physics, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom); Stetson, Peter B., E-mail: jrneeley@iastate.edu [NRC-Herzberg, Dominion Astrophysical Observatory, 5071 West Saanich Road, Victoria BC V9E 2E7 (Canada)

    2017-06-01

    We present new theoretical period–luminosity–metallicity (PLZ) relations for RR Lyræ stars (RRLs) at Spitzer and WISE wavelengths. The PLZ relations were derived using nonlinear, time-dependent convective hydrodynamical models for a broad range of metal abundances ( Z = 0.0001–0.0198). In deriving the light curves, we tested two sets of atmospheric models and found no significant difference between the resulting mean magnitudes. We also compare our theoretical relations to empirical relations derived from RRLs in both the field and in the globular cluster M4. Our theoretical PLZ relations were combined with multi-wavelength observations to simultaneously fit the distance modulus, μ {sub 0}, and extinction, A {sub V}, of both the individual Galactic RRL and of the cluster M4. The results for the Galactic RRL are consistent with trigonometric parallax measurements from Gaia ’ s first data release. For M4, we find a distance modulus of μ {sub 0} = 11.257 ± 0.035 mag with A {sub V}= 1.45 ± 0.12 mag, which is consistent with measurements from other distance indicators. This analysis has shown that, when considering a sample covering a range of iron abundances, the metallicity spread introduces a dispersion in the PL relation on the order of 0.13 mag. However, if this metallicity component is accounted for in a PLZ relation, the dispersion is reduced to ∼0.02 mag at mid-infrared wavelengths.

  8. The Carnegie-Chicago Hubble Program. II. The Distance to IC 1613: The Tip of the Red Giant Branch and RR Lyrae Period-luminosity Relations

    Science.gov (United States)

    Hatt, Dylan; Beaton, Rachael L.; Freedman, Wendy L.; Madore, Barry F.; Jang, In-Sung; Hoyt, Taylor J.; Lee, Myung Gyoon; Monson, Andrew J.; Rich, Jeffrey A.; Scowcroft, Victoria; Seibert, Mark

    2017-08-01

    IC 1613 is an isolated dwarf galaxy within the Local Group. Low foreground and internal extinction, low metallicity, and low crowding make it an invaluable testbed for the calibration of the local distance ladder. We present new, high-fidelity distance estimates to IC 1613 via its Tip of the Red Giant Branch (TRGB) and its RR Lyrae (RRL) variables as part of the Carnegie-Chicago Hubble Program, which seeks an alternate local route to H 0 using Population II stars. We have measured a TRGB magnitude {I}{ACS}{TRGB}=20.35+/- {0.01}{stat}+/- {0.01}{sys} mag using wide-field observations obtained from the IMACS camera on the Magellan-Baade telescope. We have further constructed optical and near-infrared RRL light curves using archival BI- and new H-band observations from the ACS/WFC and WFC3/IR instruments on board the Hubble Space Telescope (HST). In advance of future Gaia data releases, we set provisional values for the TRGB luminosity via the Large Magellanic Cloud and Galactic RRL zero-points via HST parallaxes. We find corresponding true distance moduli {μ }0{TRGB}=24.30+/- {0.03}{stat}+/- {0.05}{sys} {mag} and =24.28+/- {0.04}{stat+{sys}} mag. We compare our results to a body of recent publications on IC 1613 and find no statistically significant difference between the distances derived from Population I and II stars. Based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs #10505 and #13691. Additional observations are credited to the Observatories of the Carnegie Institution of Washington for the use of Magellan-Baade IMACS. Presented as part of a dissertation to the Department of Astronomy and Astrophysics, The University of Chicago, in partial fulfillment of the requirements for the Ph.D. degree.

  9. Near-infrared variability study of the central 2.3 × 2.3 arcmin2 of the Galactic Centre - II. Identification of RR Lyrae stars in the Milky Way nuclear star cluster

    Science.gov (United States)

    Dong, Hui; Schödel, Rainer; Williams, Benjamin F.; Nogueras-Lara, Francisco; Gallego-Cano, Eulalia; Gallego-Calvente, Teresa; Wang, Q. Daniel; Rich, R. Michael; Morris, Mark R.; Do, Tuan; Ghez, Andrea

    2017-11-01

    Because of strong and spatially highly variable interstellar extinction and extreme source crowding, the faint (K ≥ 15) stellar population in the Milky Way's nuclear star cluster is still poorly studied. RR Lyrae stars provide us with a tool to estimate the mass of the oldest, relative dim stellar population. Recently, we analysed HST/WFC3/IR observations of the central 2.3 × 2.3 arcmin2 of the Milky Way and found 21 variable stars with periods between 0.2 and 1 d. Here, we present a further comprehensive analysis of these stars. The period-luminosity relationship of RR Lyrae is used to derive their extinctions and distances. Using multiple approaches, we classify our sample as 4 RRc stars, 4 RRab stars, 3 RRab candidates and 10 binaries. Especially, the four RRab stars show sawtooth light curves and fall exactly on to the Oosterhoff I division in the Bailey diagram. Compared to the RRab stars reported by Minniti et al., our new RRab stars have higher extinction (AK > 1.8) and should be closer to the Galactic Centre. The extinction and distance of one RRab stars match those for the Milky Way's nuclear star cluster given in previous works. We perform simulations and find that after correcting for incompleteness, there could be not more than 40 RRab stars within the Milky Way's nuclear star cluster and in our field of view. Through comparing with the known globular clusters of the Milky Way, we estimate that if there exists an old, metal-poor (-1.5 < [Fe/H] < -1) stellar population in the Milky Way nuclear star cluster on a scale of 5 × 5 pc, then it contributes at most 4.7 × 105 M⊙, I.e. ˜18 per cent of the stellar mass.

  10. LMC clusters: young

    International Nuclear Information System (INIS)

    Freeman, K.C.

    1980-01-01

    The young globular clusters of the LMC have ages of 10 7 -10 8 y. Their masses and structure are similar to those of the smaller galactic globular clusters. Their stellar mass functions (in the mass range 6 solar masses to 1.2 solar masses) vary greatly from cluster to cluster, although the clusters are similar in total mass, age, structure and chemical composition. It would be very interesting to know why these clusters are forming now in the LMC and not in the Galaxy. The author considers the 'young globular' or 'blue populous' clusters of the LMC. The ages of these objects are 10 7 to 10 8 y, and their masses are 10 4 to 10 5 solar masses, so they are populous enough to be really useful for studying the evolution of massive stars. The author concentrates on the structure and stellar content of these young clusters. (Auth.)

  11. LMC - research group

    DEFF Research Database (Denmark)

    Fisker, Anna Marie

    2012-01-01

    Beskrivelse af Sektionen for Food+Design ved Aalborg Universitet i årsrapport 2011 for LMC, Levnedsmiddel Centeret (Danish Centre for Advanced Food Studies). Herunder beskrivelse af målsætning, fokusområder, forsknings-metoder og eksterne samarbejder....

  12. Infrared analysis of LMC superbubbles

    International Nuclear Information System (INIS)

    Verter, F.; Dwek, E.

    1990-01-01

    Researchers are analyzing three superbubbles in the Large Magellanic Cloud (LMC), cataloged by Meaburn (1980) as LMC-1, LMC-4 (a.k.a. Shapley Constellation III), and LMC-5. Superbubbles are the largest infrared sources in the disks of external galaxies. Their expansion requires multiple supernovae from successive generations of star formation. In LMC superbubbles, the grains swept up by shocks and winds represent an interstellar medium (ISM) whose abundances are quite different from the Galaxy. By applying the Dwek (1986) grain model, we can derive the composition and size spectrum of the grains. The inputs to this model are the dust emission in the four Infrared Astronomy Satellite (IRAS) bands and the interstellar radiation field (ISRF) that provides the heating. The first step in the project is to derive the ISRF for star-forming regions on the periphery of superbubbles. Researchers are doing this by combining observations at several wavelengths to determine the energy budget of the region. They will use a UV image to trace the ionizing stellar radiation that escapes, an H alpha image to trace the ionizing stellar radiation that is absorbed by gas, and the four IRAS images to trace the stellar radiation, both ionizing and non-ionizing, that is absorbed by dust. This multi-wavelength approach has the advantages that we do not have to assume the shape of the IMF or the extinction of the source

  13. Testing parallaxes with local Cepheids and RR Lyrae stars

    Czech Academy of Sciences Publication Activity Database

    Clementini, G.; Eyer, L.; Ripepi, V.; Marconi, M.; Muraveva, T.; Garofalo, A.; Sarro, L.M.; Palmer, M.; Luri, X.; Koubský, Pavel; Votruba, Viktor

    2017-01-01

    Roč. 605, September (2017), A79/1-A79/29 E-ISSN 1432-0746 R&D Projects: GA MŠk(CZ) LG15010 Grant - others:ESA(XE) ESA-PECS project no. 98058 Institutional support: RVO:67985815 Keywords : astrometry * parallaxes * stars Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics OBOR OECD: Astronomy (including astrophysics,space science) Impact factor: 5.014, year: 2016

  14. Dynamical investigation of modulated Kepler RR Lyrae stars

    Directory of Open Access Journals (Sweden)

    Plachy E.

    2015-01-01

    Full Text Available We performed a non-linear dynamical analysis on the Blazhko modulation for the first time. Our results suggest that the detection of chaotic nature behind the phenomenon is limited by the instrumental effects and the data processing problems of the Kepler pipeline concerning high-amplitude variable stars.

  15. PULSATION PERIOD VARIATIONS IN THE RRc LYRAE STAR KIC 5520878

    Energy Technology Data Exchange (ETDEWEB)

    Hippke, Michael [Institute for Data Analysis, Luiter Str. 21b, D-47506 Neukirchen-Vluyn (Germany); Learned, John G. [High Energy Physics Group, Department of Physics and Astronomy, University of Hawaii, Manoa 327 Watanabe Hall, 2505 Correa Road, Honolulu, HI 96822 (United States); Zee, A. [Kavli Institute for Theoretical Physics, University of California, Santa Barbara, CA 93106 (United States); Edmondson, William H. [School of Computer Science, University of Birmingham, Birmingham B15 2TT (United Kingdom); Lindner, John F. [Physics Department, The College of Wooster, Wooster, OH 44691 (United States); Kia, Behnam; Ditto, William L. [Department of Physics and Astronomy, University of Hawai' i at Mānoa, Honolulu, HI 96822 (United States); Stevens, Ian R., E-mail: hippke@ifda.eu, E-mail: jgl@phys.hawaii.edu, E-mail: zee@kitp.ucsb.edu, E-mail: w.h.edmondson@bham.ac.uk, E-mail: jlindner@wooster.edu, E-mail: wditto@hawaii.edu, E-mail: behnam@hawaii.edu, E-mail: irs@star.sr.bham.ac.uk [School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT (United Kingdom)

    2015-01-01

    Learned et al. proposed that a sufficiently advanced extra-terrestrial civilization may tickle Cepheid and RR Lyrae variable stars with a neutrino beam at the right time, thus causing them to trigger early and jogging the otherwise very regular phase of their expansion and contraction. This would turn these stars into beacons to transmit information throughout the galaxy and beyond. The idea is to search for signs of phase modulation (in the regime of short pulse duration) and patterns, which could be indicative of intentional, omnidirectional signaling. We have performed such a search among variable stars using photometric data from the Kepler space telescope. In the RRc Lyrae star KIC 5520878, we have found two such regimes of long and short pulse durations. The sequence of period lengths, expressed as time series data, is strongly autocorrelated, with correlation coefficients of prime numbers being significantly higher (p = 99.8%). Our analysis of this candidate star shows that the prime number oddity originates from two simultaneous pulsation periods and is likely of natural origin. Simple physical models elucidate the frequency content and asymmetries of the KIC 5520878 light curve. Despite this SETI null result, we encourage testing of other archival and future time-series photometry for signs of modulated stars. This can be done as a by-product to the standard analysis, and can even be partly automated.

  16. Carbon stars in lmc clusters revisited

    OpenAIRE

    Marigo, Paola; Girardi, Leo Alberto; Chiosi, Cesare

    1996-01-01

    Examining the available data for AGB stars in the Large Magellanic Cloud (LMC) clusters, we address the question about the mass interval of low- and intermediate-mass stars which eventually evolve into carbon stars (C stars) during the TP-AGB phase. We combine the data compiled by Frogel, Mould & Blanco (1990) - near infrared photometry and spectral classification for luminous AGB stars in clusters - with the ages for individual clusters derived from independent methods. The resulting distrib...

  17. Equilibrium figures for beta Lyrae type disks

    International Nuclear Information System (INIS)

    Wilson, R.E.

    1981-01-01

    Accumulated evidence for a geometrically and optically thick disk in the β Lyrae system has now established the disk's basic external configuration. Since the disk has been constant in its main properties over the historical interval of β Lyrae observations and also seems to have a basically well-defined photosphere, it is now time to being consideration of its sturcture. Here, we compute equilibrium figures for self-gravitating disks around stars in binary systems as a start toward eventual computation of complete disk models. A key role is played by centrifugally limited rotation of the central star, which would naturally arise late in the rapid phase of mass transfer. Beta Lyrae is thus postulated to be a double-contact binary, which makes possible nonarbitrary separation of star and disk into separate structures. The computed equilibrium figures are three-dimensional, as the gravitation of the second star is included. Under the approximation that the gravitational potential of the disk is that of a thin wire and that the local disk angular velocity is proportional to u/sup n/ (u = distance from rotation axis), we comptue the total potential and locate equipotential surfaces. The centrifugal potential is written in a particularly convenient form which permits one to change the rotation law discontinuously (for example, at the star-disk coupling point) while ensuring that centrifugal potential and centrifigual force are continuous functions of position. With such a one-parameter rotation law, one can find equilibrium disk figures with dimensions very similar to those found in β Lyrae, but considerations of internal consistency demand at least a two-parameter law

  18. Dense molecular clumps associated with the Large Magellanic Cloud supergiant shells LMC 4 and LMC 5

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Kosuke; Mizuno, Norikazu [Department of Astronomy, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 133-0033 (Japan); Minamidani, Tetsuhiro [Nobeyama Radio Observatory, 462-2 Nobeyama Minamimaki-mura, Minamisaku-gun, Nagano 384-1305 (Japan); Onishi, Toshikazu; Muraoka, Kazuyuki [Department of Physical Science, Osaka Prefecture University, Gakuen 1-1, Sakai, Osaka 599-8531 (Japan); Kawamura, Akiko; Muller, Erik; Tatematsu, Ken' ichi; Hasegawa, Tetsuo; Miura, Rie E.; Ezawa, Hajime [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Dawson, Joanne [Australia Telescope National Facility, CSIRO Astronomy and Space Science, P.O. Box 76, Epping, NSW 1710 (Australia); Tosaki, Tomoka [Joetsu University of Education, Yamayashiki-machi, Joetsu, Niigata 943-8512 (Japan); Sakai, Takeshi [Graduate School of Informatics and Engineering, The University of Electro-Communications, Chofu, Tokyo 182-8585 (Japan); Tsukagoshi, Takashi [College of Science, Ibaraki University, Bunkyo 2-1-1, Mito 310-8512 (Japan); Tanaka, Kunihiko [Department of Physics, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Yokohama, Kanagawa 223-8522 (Japan); Fukui, Yasuo, E-mail: kosuke.fujii@nao.ac.jp [Department of Astrophysics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan)

    2014-12-01

    We investigate the effects of supergiant shells (SGSs) and their interaction on dense molecular clumps by observing the Large Magellanic Cloud (LMC) star-forming regions N48 and N49, which are located between two SGSs, LMC 4 and LMC 5. {sup 12}CO (J = 3-2, 1-0) and {sup 13}CO(J = 1-0) observations with the ASTE and Mopra telescopes have been carried out toward these regions. A clumpy distribution of dense molecular clumps is revealed with 7 pc spatial resolution. Large velocity gradient analysis shows that the molecular hydrogen densities (n(H{sub 2})) of the clumps are distributed from low to high density (10{sup 3}-10{sup 5} cm{sup –3}) and their kinetic temperatures (T {sub kin}) are typically high (greater than 50 K). These clumps seem to be in the early stages of star formation, as also indicated from the distribution of Hα, young stellar object candidates, and IR emission. We found that the N48 region is located in the high column density H I envelope at the interface of the two SGSs and the star formation is relatively evolved, whereas the N49 region is associated with LMC 5 alone and the star formation is quiet. The clumps in the N48 region typically show high n(H{sub 2}) and T {sub kin}, which are as dense and warm as the clumps in LMC massive cluster-forming areas (30 Dor, N159). These results suggest that the large-scale structure of the SGSs, especially the interaction of two SGSs, works efficiently on the formation of dense molecular clumps and stars.

  19. LYRA, a webserver for lymphocyte receptor structural modeling

    DEFF Research Database (Denmark)

    Klausen, Michael Schantz; Anderson, Mads Valdemar; Jespersen, Martin Closter

    2015-01-01

    the structural class of each hypervariable loop, selects the best templates in an automatic fashion, and provides within minutes a complete 3D model that can be downloaded or inspected online. Experienced users can manually select or exclude template structures according to case specific information. LYRA......The accurate structural modeling of B- and T-cell receptors is fundamental to gain a detailed insight in the mechanisms underlying immunity and in developing new drugs and therapies. The LYRA (LYmphocyte Receptor Automated modeling) web server (http://www.cbs.dtu.dk/services/LYRA/) implements...... a complete and automated method for building of B- and T-cell receptor structural models starting from their amino acid sequence alone. The webserver is freely available and easy to use for non-specialists. Upon submission, LYRA automatically generates alignments using ad hoc profiles, predicts...

  20. Weak Galactic halo-Fornax dSph connection from RR Lyrae stars

    NARCIS (Netherlands)

    Fiorentino, G.; Monelli, M.; Stetson, P. B.; Bono, G.; Gallart, C.; Martínez-Vázquez, C. E.; Bernard, E. J.; Massari, D.; Braga, V. F.; Dall'Ora, M.

    2017-01-01

    Aims: For the first time accurate pulsation properties of the ancient variable stars of the Fornax dwarf spheroidal galaxy (dSph) are discussed in the broad context of galaxy formation and evolution. Methods: Homogeneous multi-band BVI optical photometry of spanning twenty years has allowed us to

  1. An RR Lyrae period shift in terms of the Fourier parameter Phi sub 31

    Science.gov (United States)

    Clement, Christine M.; Jankulak, Michael; Simon, Norman R.

    1992-01-01

    The Fourier phase parameter Phi sub 31 has been determined for RRc stars in five globular clusters, NGC 6171, M5, M3, M53, and M15. The results indicate that the RRc stars in a given cluster show a sequence of Phi sub 31 increasing with period, and that the higher the cluster metallicity, the higher the sequence lies in a plot of Phi sub 31 with period. The Phi sub 31 values for the stars in NGC 6171 and M5 presented here are based on observations made with the University of Toronto 0.61 m telescope at Las Campanas, Chile, while those for M3, M53, and M15 are based on published data. A bootstrap procedure has been used to establish the uncertainties in the Fourier parameters. The physical significance of the relationship among Phi sub 31, period, and metallicity is not yet understood. It will need to be tested with hydrodynamic pulsation models computed with new opacities.

  2. Kepler photometry of the prototypical Blazhko star RR Lyr: an old friend seen in a new light

    DEFF Research Database (Denmark)

    Kolenberg, Katrien; Bryson, S.; Szabó, R.

    2011-01-01

    We present our analysis of the long-cadence Kepler data for the well-studied Blazhko star RR Lyr, gathered during the first two quarters of the satellite's observations and covering a total of 127 d. Besides being of great importance for our understanding of RR Lyrae stars in general, these RR Lyr...... data can be regarded as a case study for observations of bright stars with Kepler. Kepler can perform high-precision photometry on targets like RR Lyr, as the saturated flux is conserved to a very high degree. The Kepler data on RR Lyr are revolutionary in several respects. Even with long......-cadence sampling (one measurement per 29.4 min), the unprecedented precision (star's extreme light-curve variations in detail. The multiplet structures at the main frequency and its harmonics, typical for Blazhko stars, are clearly detected up...

  3. E2 - an intermediate-age LMC cluster

    International Nuclear Information System (INIS)

    Schommer, R.A.; Olszewski, E.W.; Aaronson, M.; Steward Observatory, Tucson, AZ)

    1986-01-01

    A color-magnitude diagram is presented for the faint star cluster E2, located near the tip of the Magellanic Stream. The main-sequence turnoff, a few giants, and a giant clump can be discerned. Comparisons with VandenBerg models show E2 to be a 1.5 Gyr old cluster with abundance Z of about 0.01 at the distance of the LMC, and thus similar to the more populous intermediate-age LMC clusters. The existence of cluster formation at a large distance from the LMC center (E2 is at almost 8 deg radius) is discussed in the context of the star-formation history, structure, and kinematics of the outer halo of the Large Magellanic Cloud. 42 references

  4. Preliminary Results on Irradiance Measurements from Lyra and Swap

    Directory of Open Access Journals (Sweden)

    S. T. Kumara

    2012-01-01

    the period from 01 April 2010 to 15 Mar 2011. We found that there is a good correlation between these parameters. This indicates that the spatial resolution of SWAP complements the high temporal resolution of LYRA. Hence SWAP can be considered as an additional radiometric channel. Also the K emission index is the integrated intensity (or flux over a 1 Å band centered on the K line and is proportional to the total emission from the chromosphere; this comparison clearly explains that the LYRA irradiance variations are due to the various magnetic features, which are contributing significantly. In addition to this we have made an attempt to segregate coronal features from full-disk SWAP images. This will help to understand and determine the actual contribution of the individual coronal feature to LYRA irradiance variations.

  5. Bianchi-IX string cosmological model in Lyra geometry

    Indian Academy of Sciences (India)

    field in Lyra's geometry will either include a creation field and be equal to Hoyle's cre- ation field cosmology or contain a special vacuum field which together with the gauge vector term may be considered as a cosmological term. Subsequent investigations were done by several authors in scalar–tensor theory and cos-.

  6. Redetermination of the luminosity, distance, and reddening of Beta Lyrae

    International Nuclear Information System (INIS)

    Dobias, J.J.; Plavec, M.J.

    1985-01-01

    We have redetermined the distance to β Lyrae and found that it probably lies between 345 and 400 pc, with the most likely value being 370 pc. With the corresponding true distance modulus of 7.8 mag, we find that the eclipsing system of β Lyrae has a maximum absolute visual magnitude of -4.7 mag. Using Wilson's model, we conclude that the average absolute visual magnitude of the primary component is -4.1 mag, so that the star is best classified as B8.5 or B9 II-Ib. The visual absolute magnitude of the secondary component is -3.3 mag, but this figure cannot be used to derive its luminosity, since that object has a nonstellar energy distribution. The color excess is small, E(B-V) = 0.04 mag. These data are based on our optical and IUE scans of the brightest visual companion to β Lyrae, HD 174664, and on an analysis of the hydrogen line profiles in its spectrum. We find that the star is mildly evolved within the main-sequence band. Its effective temperature (14 250 K) and surface gravity (log gapprox. =4.0) correspond most closely to those of stars classified as B6 V. This conclusion creates a certain evolutionary dilemma, since the age of HD 174664 should not exceed 20--30 million years if the basic model of β Lyrae as an Algol-type binary is correct, while our result is 48 x 10 6 yr. We address this problem at the end of the paper and conclude that the discrepancy may well be due to uncertainties in observational data and theoretical models and in the various calibrations involved. Nevertheless, attention should be paid to this potential age dilemma for β Lyrae

  7. OGLE II Eclipsing Binaries In The LMC: Analysis With Class

    Science.gov (United States)

    Devinney, Edward J.; Prsa, A.; Guinan, E. F.; DeGeorge, M.

    2011-01-01

    The Eclipsing Binaries (EBs) via Artificial Intelligence (EBAI) Project is applying machine learning techniques to elucidate the nature of EBs. Previously, Prsa, et al. applied artificial neural networks (ANNs) trained on physically-realistic Wilson-Devinney models to solve the light curves of the 1882 detached EBs in the LMC discovered by the OGLE II Project (Wyrzykowski, et al.) fully automatically, bypassing the need for manually-derived starting solutions. A curious result is the non-monotonic distribution of the temperature ratio parameter T2/T1, featuring a subsidiary peak noted previously by Mazeh, et al. in an independent analysis using the EBOP EB solution code (Tamuz, et al.). To explore this and to gain a fuller understanding of the multivariate EBAI LMC observational plus solutions data, we have employed automatic clustering and advanced visualization (CAV) techniques. Clustering the OGLE II data aggregates objects that are similar with respect to many parameter dimensions. Measures of similarity for example, could include the multidimensional Euclidean Distance between data objects, although other measures may be appropriate. Applying clustering, we find good evidence that the T2/T1 subsidiary peak is due to evolved binaries, in support of Mazeh et al.'s speculation. Further, clustering suggests that the LMC detached EBs occupying the main sequence region belong to two distinct classes. Also identified as a separate cluster in the multivariate data are stars having a Period-I band relation. Derekas et al. had previously found a Period-K band relation for LMC EBs discovered by the MACHO Project (Alcock, et al.). We suggest such CAV techniques will prove increasingly useful for understanding the large, multivariate datasets increasingly being produced in astronomy. We are grateful for the support of this research from NSF/RUI Grant AST-05-75042 f.

  8. Spectrophotometry of RR Telescopii

    International Nuclear Information System (INIS)

    Walker, A.R.

    1977-01-01

    The strongest emission lines in the nova-like variable RR Telescopii were measured during late 1974 using a spectrum scanner. The wavelength range 3350 to 7700 A was scanned with a resolution of 50 A. The results are compared with published spectrophotometry covering the period 1961 to 72, with the conclusion that few changes have taken place in the last 6 yr. No evidence was found that suggested the existence of a cool star, nor was there any indication of night-to-night changes in the emission line intensities. The spectrophotometry of the past 15 yr is consistent with an expanding shell, the emission from this shell being caused by high-energy radiation from an underlying star. (author)

  9. Interacting Quintessence Dark Energy Models in Lyra Manifold

    International Nuclear Information System (INIS)

    Khurshudyan, M.; Myrzakulov, R.; Sadeghi, J.; Farahani, H.; Pasqua, Antonio

    2014-01-01

    We consider two-component dark energy models in Lyra manifold. The first component is assumed to be a quintessence field while the second component may be a viscous polytropic gas, a viscous Van der Waals gas, or a viscous modified Chaplygin gas. We also consider the possibility of interaction between components. By using the numerical analysis, we study some cosmological parameters of the models and compare them with observational data.

  10. Three candidate double clusters in the LMC: truth or dare?

    Science.gov (United States)

    Dalessandro, Emanuele; Zocchi, Alice; Varri, Anna Lisa; Mucciarelli, Alessio; Bellazzini, Michele; Ferraro, Francesco R.; Lanzoni, Barbara; Lapenna, Emilio; Origlia, Livia

    2018-02-01

    The Large Magellanic Cloud (LMC) hosts a large number of candidate stellar cluster pairs. Binary stellar clusters provide important clues about cluster formation processes and the evolutionary history of the host galaxy. However, to properly extract and interpret this information, it is crucial to fully constrain the fraction of real binary systems and their physical properties. Here we present a detailed photometric analysis based on ESO-FORS2 images of three candidate cluster multiplets in the LMC, namely SL349-SL353, SL385-SL387-NGC 1922 and NGC 1836-BRHT4b-NGC 1839. For each cluster, we derived ages, structural parameters and morphological properties. We have also estimated the degree of filling of their Roche lobe, as an approximate tool to measure the strength of the tidal perturbations induced by the LMC. We find that the members of the possible pairs SL349-SL353 and BRHT4b-NGC 1839 have a similar age (t = 1.00 ± 0.12 Gyr and t = 140 ± 15 Myr, respectively), thus possibly hinting at a common origin of their member systems. We also find that all candidate pairs in our sample show evidence of intracluster overdensities that can be a possible indication of real binarity. Particularly interesting is the case of SL349-SL353. In fact, SL353 is relatively close to the condition of critical filling, thus suggesting that these systems might actually constitute an energetically bound pair. It is therefore key to pursue a detailed kinematic screening of such clusters, without which, at present, we do not dare making a conclusive statement about the true nature of this putative pair.

  11. Bright X-ray transient in the LMC

    Science.gov (United States)

    Saxton, R.; Read, A. M.; Li, D. Y.

    2018-01-01

    We report a bright X-ray transient in the LMC from an XMM-Newton slew made on 5th January 2018. The source, XMMSL2 J053629.4-675940, had a soft X-ray (0.2-2 keV) count rate in the EPIC-pn detector, medium filter of 1.82+/-0.56 c/s, equivalent to a flux Fx=2.3+/-0.7E-12 ergs/s/cm2 for a nominal spectrum of a power-law of slope 2 absorbed by a column NH=3E20 cm^-2.

  12. On the problem of the chemical composition of β Lyrae

    International Nuclear Information System (INIS)

    Bahyl, V.

    1982-01-01

    Two determinations of helium abundance in the primary β Lyrae's component existed before 1975. According to Boyarchuk (1959) helium is 631 times overabundant relative to hydrogen and according to Hack and Job (1965) the ratio He/H varies from 1 to 2.25 depending on the effective temperature. The author has examined this problem with the aim of deciding between these extreme results. He started from models of the atmosphere and calculated the theoretical profiles. He has found the best fit for the model Boehm-Vitense (1967), Tsub(eff) = 12,900K, log g = 2 and He/H = 2.72. (Auth.)

  13. Hydrodynamical models of supernova SN 1987 A in the LMC

    International Nuclear Information System (INIS)

    Grassberg, E.K.; Imshennik, V.S.; Nadezhin, D.K.; Utrobin, V.P.

    1987-01-01

    It is shown that the properties of SN 1987A in LMC can be described well by hydrodynamical models of explosions of compact massive stars. In accordance with these models, the mass of the expelled envelope the presupernova radius and the total energy of explosion are evaluated for SN 1987A to be ∼ 16M Sun , ∼ 30R Sun , and ∼ 3.10 51 erg, respectively. The progenitor of supernova remnant Cas A may be considered as the prototype to the SN 1987A in our own Galaxy. In other galaxies, this subtype of supernovae can be represented by SN 1948B in NGC6946. If energy of explosion transfers from collapsed core of the star to the envelope within timescale less than 1 hour, then delay Δt ∼ 3 hours between the neutrino pulse and the steep rise of optical luminosity of SN 1987A does not contradict with scenario of explosions of compact massive stars

  14. Constraining the Mass Loss Geometry of Beta Lyrae

    Directory of Open Access Journals (Sweden)

    Jamie R. Lomax

    2012-03-01

    Full Text Available Massive binary stars lose mass by two mechanisms: jet-driven mass loss during periods of active mass transfer and by wind-driven mass loss. Beta Lyrae is an eclipsing, semi-detached binary whose state of active mass transfer provides a unique opportunity to study how the evolution of binary systems is affected by jet-driven mass loss. Roche lobe overflow from the primary star feeds the thick accretion disk which almost completely obscures the mass-gaining star. A hot spot predicted to be on the edge of the accretion disk may be the source of beta Lyrae’s bipolar outflows. I present results from spectropolarimetric data taken with the University of Wisconsin’s Half-Wave Spectropolarimeter and the Flower and Cook Observatory’s photoelastic modulating polarimeter instrument which have implications for our current understanding of the system’s disk geometry. Using broadband polarimetric analysis, I derive new information about the structure of the disk and the presence and location of a hot spot. These results place constraints on the geometrical distribution of material in beta Lyrae and can help quantify the amount of mass lost from massive interacting binary systems during phases of mass transfer and jet-driven mass loss.

  15. First detection of multi-shocks in RR Lyrae stars from Antarctica : A possible explanation of the Blazhko effect

    International Nuclear Information System (INIS)

    Chadid, M.; Vernin, J.; Zalian, C.; Pouzenc, C.; Abe, L.; Agabi, A.; Aristidi, E.; Mékarnia, D.; Preston, G.; Liu, L.Y.; Trinquet, H.

    2014-01-01

    We present the first detection of multi-shocks propagating through the atmosphere of the Blazhko star S Arae using uninterrupted, accurate optical photometric data collected during one polar night, 150 days from Antarctica at Dome C, with the Photometer AntarctIca eXtinction (PAIX). We acquired 89,736 CCD frames during 323 pulsation cycles and 3 Blazhko cycles. We detected two new light curve properties in the PAIX light curve, jump and rump, which we associated with two new post-maximum shock waves Sh PM1 and Sh PM2 . jump, lump, rump, bump, and hump are induced by five shock waves, with different amplitudes and origins, Sh PM1 , Sh PM , Sh PM2 , Sh PM3 , and the main shock Sh H+He . Correlations between the length of rise time and light amplitude and Sh PM3 are monotonous during three Blazhko cycles, but the pulsation curve is double peaked. We discuss the physical mechanisms driving the modulation of these quantities. Finally, we hypothesize that the origin of the Blazhko effect is a dynamical interaction between a multi-shock structure and an outflowing wind in a coronal structure.

  16. First detection of multi-shocks in RR Lyrae stars from Antarctica : A possible explanation of the Blazhko effect

    Energy Technology Data Exchange (ETDEWEB)

    Chadid, M.; Vernin, J.; Zalian, C.; Pouzenc, C.; Abe, L.; Agabi, A.; Aristidi, E.; Mékarnia, D. [Université Nice Sophia-Antipolis, Observatoire de la Côte d' Azur, UMR 7293, Parc Valrose, F-06108 Nice Cedex 02 (France); Preston, G. [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Liu, L.Y. [National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing (China); Trinquet, H., E-mail: chadid@unice.fr [DGA Matrise de l' Information, BP 7, F-35998 Rennes Armees (France)

    2014-11-01

    We present the first detection of multi-shocks propagating through the atmosphere of the Blazhko star S Arae using uninterrupted, accurate optical photometric data collected during one polar night, 150 days from Antarctica at Dome C, with the Photometer AntarctIca eXtinction (PAIX). We acquired 89,736 CCD frames during 323 pulsation cycles and 3 Blazhko cycles. We detected two new light curve properties in the PAIX light curve, jump and rump, which we associated with two new post-maximum shock waves Sh{sub PM1} and Sh{sub PM2}. jump, lump, rump, bump, and hump are induced by five shock waves, with different amplitudes and origins, Sh{sub PM1}, Sh{sub PM}, Sh{sub PM2}, Sh{sub PM3}, and the main shock Sh{sub H+He}. Correlations between the length of rise time and light amplitude and Sh{sub PM3} are monotonous during three Blazhko cycles, but the pulsation curve is double peaked. We discuss the physical mechanisms driving the modulation of these quantities. Finally, we hypothesize that the origin of the Blazhko effect is a dynamical interaction between a multi-shock structure and an outflowing wind in a coronal structure.

  17. A comparison of LMC and SDL complexity measures on binomial distributions

    Science.gov (United States)

    Piqueira, José Roberto C.

    2016-02-01

    The concept of complexity has been widely discussed in the last forty years, with a lot of thinking contributions coming from all areas of the human knowledge, including Philosophy, Linguistics, History, Biology, Physics, Chemistry and many others, with mathematicians trying to give a rigorous view of it. In this sense, thermodynamics meets information theory and, by using the entropy definition, López-Ruiz, Mancini and Calbet proposed a definition for complexity that is referred as LMC measure. Shiner, Davison and Landsberg, by slightly changing the LMC definition, proposed the SDL measure and the both, LMC and SDL, are satisfactory to measure complexity for a lot of problems. Here, SDL and LMC measures are applied to the case of a binomial probability distribution, trying to clarify how the length of the data set implies complexity and how the success probability of the repeated trials determines how complex the whole set is.

  18. The ROSAT All-Sky Survey view of the Large Magellanic Cloud (LMC)

    Science.gov (United States)

    Pietsch, W.; Denner, K.; Kahabka, P.; Pakull, M.; Schaeidt, S.

    1996-01-01

    During the Rosat all sky survey, centered on the Large Magellanic Cloud (LMC), 516 X-ray sources were detected. The field was covered from July 1990 to January 1991. The X-ray parameters of the sources, involving position, count rates, hardness ratios, extent, and time variability during the observations, are discussed. Identifications with objects from optical, radio and infrared wavelength allow the LMC candidates to be separated from the foreground stars and the background objects.

  19. A cautionary tale of interpreting O-C diagrams: period instability in a classical RR Lyr Star Z CVn mimicking as a distant companion

    Science.gov (United States)

    Skarka, M.; Liška, J.; Dřevěný, R.; Guggenberger, E.; Sódor, Á.; Barnes, T. G.; Kolenberg, K.

    2018-02-01

    We present a comprehensive study of Z CVn, an RR Lyrae star that shows long-term cyclic variations of its pulsation period. A possible explanation suggested from the shape of the O-C diagram is the light travel-time effect, which we thoroughly examine. We used original photometric and spectroscopic measurements and investigated the period evolution using available maximum times spanning more than one century. If the binary hypothesis is valid, Z CVn orbits around a black hole with minimal mass of 56.5 M_{⊙} on a very wide (Porbit = 78.3 yr) and eccentric orbit (e = 0.63). We discuss the probability of the formation of a black hole-RR Lyrae pair, and, although we found it possible, there is no observational evidence of the black hole in the direction to Z CVn. However, the main objection against the binary hypothesis is the comparison of the systemic radial velocity curve model and spectroscopic observations that clearly show that Z CVn cannot be bound in such a binary. Therefore, the variations of pulsation period are likely intrinsic to the star. This finding represents a discovery/confirmation of a new type of cyclic period changes in RR Lyrae stars. By the analysis of our photometric data, we found that the Blazhko modulation with period of 22.931 d is strongly dominant in amplitude. The strength of the phase modulation varies and is currently almost undetectable. We also estimated photometric physical parameters of Z CVn and investigated their variations during the Blazhko cycle using the inverse Baade-Wesselink method.

  20. Physical Properties of the LMC Eclipsing Binary Stars

    Science.gov (United States)

    Prsa, Andrej; Devinney, E. J.; Guinan, E. F.; Engle, S. G.; DeGeorge, M.

    2009-01-01

    To date, three independent studies have devised an automatic procedure to analyse and extract the principal parameters of 2581 detached eclipsing binary stars from the OGLE photometric survey of the Large Magellanic Cloud (LMC): Devor (2005), Tamuz et al. (2006), and Prsa et al. (2008). For time efficiency, Devor used a simple model of two spherical, limb-darkened stars without tidal or reflection physics. Tamuz et al.'s approach employs a more realistic EBOP model, which is still limited in handling proximity physics. Our study used a back-propagating neural network that was trained on the light curves computed by a modern Wilson-Devinney code. The three approaches are confronted and correlations in the results are sought that indicate the degree of reliability of the obtained results. A database of solutions consistent across all three studies is presented. We assess the suitability of each method for other morphology types (i.e. semi-detached and overcontact binaries) and we overview the practical limitations of these methods for the upcoming survey data. This research is supported by NFS/RUI Grant No. AST-05-07542, which we gratefully acknowledge.

  1. Evolution of LMC/M33-mass dwarf galaxies in the EAGLE simulation

    Science.gov (United States)

    Shao, Shi; Cautun, Marius; Deason, Alis J.; Frenk, Carlos S.; Theuns, Tom

    2018-06-01

    We investigate the population of dwarf galaxies with stellar masses similar to the Large Magellanic Cloud (LMC) and M33 in the EAGLE galaxy formation simulation. In the field, galaxies reside in haloes with stellar-to-halo mass ratios of 1.03^{+0.50}_{-0.31}× 10^{-2} (68% confidence level); systems like the LMC, which have an SMC-mass satellite, reside in haloes about 1.3 times more massive, which suggests an LMC halo mass at infall, M_{200}=3.4^{+1.8}_{-1.2}× 10^{11}{ M_⊙ } (68% confidence level). The colour distribution of dwarfs is bimodal, with the red galaxies (g - r > 0.6) being mostly satellites. The fraction of red LMC-mass dwarfs is 15% for centrals, and for satellites this fraction increases rapidly with host mass: from 10% for satellites of Milky Way (MW)-mass haloes to nearly 90% for satellites of groups and clusters. The quenching timescale, defined as the time after infall when half of the satellites have acquired red colours, decreases with host mass from >5 Gyrs for MW-mass hosts to 2.5 Gyrs for cluster mass hosts. The satellites of MW-mass haloes have higher star formation rates and bluer colours than field galaxies. This is due to enhanced star formation triggered by gas compression shortly after accretion. Both the LMC and M33 have enhanced recent star formation that could be a manifestation of this process. After infall into their MW-mass hosts, the g - r colours of LMC-mass dwarfs become bluer for the first 2 Gyrs, after which they rapidly redden. LMC-mass dwarfs fell into their MW-mass hosts only relatively recently, with more than half having an infall time of less than 3.5 Gyrs.

  2. The mass of the black hole in LMC X-3

    Energy Technology Data Exchange (ETDEWEB)

    Orosz, Jerome A. [Department of Astronomy, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-1221 (United States); Steiner, James F.; McClintock, Jeffrey E. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Buxton, Michelle M.; Bailyn, Charles D. [Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520-8101 (United States); Steeghs, Danny [Department of Physics, University of Warwick, Coventry, CV4 7AL, UK and Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Guberman, Alec [Byram Hills High School, 12 Tripp Lane, Armonk, NY 10504 (United States); Torres, Manuel A. P., E-mail: jorosz@mail.sdsu.edu, E-mail: jsteiner@cfa.harvard.edu, E-mail: jem@cfa.harvard.edu, E-mail: michelle.buxton@yale.edu, E-mail: charles.bailyn@yale.edu, E-mail: D.T.H.Steeghs@warwick.ac.uk, E-mail: alec.guberman@stonybrook.edu, E-mail: M.Torres@sron.nl [SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht (Netherlands)

    2014-10-20

    We analyze a large set of new and archival photometric and spectroscopic observations of LMC X-3 to arrive at a self-consistent dynamical model for the system. Using echelle spectra obtained with the Magellan Inamori Kyocera Echelle instrument on the 6.5 m Magellan Clay telescope and the UVES instrument on the second 8.2 m Very Large Telescope, we find a velocity semiamplitude for the secondary star of K {sub 2} = 241.1 ± 6.2 km s{sup –1}, where the uncertainty includes an estimate of the systematic error caused by X-ray heating. Using the spectra, we also find a projected rotational velocity of V {sub rot}sin i = 118.5 ± 6.6 km s{sup –1}. From an analysis of archival B and V light curves as well as new B and V light curves from the SMARTS 1.3 m telescope, we find an inclination of i = 69.°84 ± 0.°37 for models that do not include X-ray heating and an inclination of i = 69.°24 ± 0.°72 for models that incorporate X-ray heating. Adopting the latter inclination measurement, we find masses of 3.63 ± 0.57 M {sub ☉} and 6.98 ± 0.56 M {sub ☉} for the companion star and the black hole, respectively. We briefly compare our results with earlier work and discuss some of their implications.

  3. Near-Field Cosmology with Resolved Stellar Populations Around Local Volume LMC Stellar-Mass Galaxies

    Science.gov (United States)

    Carlin, Jeffrey L.; Sand, David J.; Willman, Beth; Brodie, Jean P.; Crnojevic, Denija; Forbes, Duncan; Hargis, Jonathan R.; Peter, Annika; Pucha, Ragadeepika; Romanowsky, Aaron J.; Spekkens, Kristine; Strader, Jay

    2018-06-01

    We discuss our ongoing observational program to comprehensively map the entire virial volumes of roughly LMC stellar mass galaxies at distances of ~2-4 Mpc. The MADCASH (Magellanic Analog Dwarf Companions And Stellar Halos) survey will deliver the first census of the dwarf satellite populations and stellar halo properties within LMC-like environments in the Local Volume. Our results will inform our understanding of the recent DES discoveries of dwarf satellites tentatively affiliated with the LMC/SMC system. This program has already yielded the discovery of the faintest known dwarf galaxy satellite of an LMC stellar-mass host beyond the Local Group, based on deep Subaru+HyperSuprimeCam imaging reaching ~2 magnitudes below its TRGB, and at least two additional candidate satellites. We will summarize the survey results and status to date, highlighting some challenges encountered and lessons learned as we process the data for this program through a prototype LSST pipeline. Our program will examine whether LMC stellar mass dwarfs have extended stellar halos, allowing us to assess the relative contributions of in-situ stars vs. merger debris to their stellar populations and halo density profiles. We outline the constraints on galaxy formation models that will be provided by our observations of low-mass galaxy halos and their satellites.

  4. Variations in EUV Irradiance: Comparison between LYRA, ESP, and SWAP Integrated Flux

    Directory of Open Access Journals (Sweden)

    Mehmet Sarp Yalim

    2014-01-01

    Full Text Available The Sun Watcher Using Active Pixel System Detector and Image Processing (SWAP telescope and Large Yield Radiometer (LYRA are the two Sun observation instruments on-board PROBA2. SWAP extreme ultraviolet images, if presented in terms of the integrated flux over solar disk, in general, correlate well with LYRA channel 2–4 (zirconium filter and channels QD and 18 of EVE/ESP on-board SDO between 2010 and 2013. Hence, SWAP can be considered as an additional radiometric channel. We compare in detail LYRA channel 2–4 and SWAP integrated flux in July 2010 and in particular during the solar eclipse that occurred on July 11, 2010. During this eclipse, the discrepancy between the two data channels can be explained to be related to the occultation of active region 11087 by the Moon. In the second half of July 2010, LYRA channel 2–4 and SWAP integrated flux deviate from each other, but these differences can also be explained in terms of features appearing on the solar disk such as coronal holes and active regions. By additionally comparing with timeline of EVE/ESP, we can preliminarily interpret these differences in terms of the difference between the broad bandpass of LYRA channel 2–4 and the, relatively speaking, narrower bandpass of SWAP.

  5. Energy and particle control characteristics of the ASDEX Upgrade 'LYRA' divertor

    International Nuclear Information System (INIS)

    Kaufmann, M.; Bosch, H.S.; Herrmann, A.

    1999-01-01

    In 1997 the new 'LYRA' divertor went into operation at ASDEX Upgrade and the neutral beam heating power was increased to 20 MW by installation of a second injector. This leads to the relatively high value of P/R of 12 MW/m. It has been shown that the ASDEX Upgrade LYRA divertor is capable of handling such high heating powers. Measurements presented in this paper reveal a reduction of the maximum heat flux in the LYRA divertor by more than a factor of two compared to the open Divertor I. This reduction is caused by radiative losses inside the divertor region. Carbon radiation cools the divertor plasma down to a few eV where hydrogen radiation losses become significant. They are increased due to an effective reflection of neutrals into the hot separatrix region. B2-Eirene modelling of the performed experiments supports the experimental findings and refines the understanding of loss processes in the divertor region. (author)

  6. Energy and particle control characteristics of the ASDEX Upgrade 'LYRA' divertor

    International Nuclear Information System (INIS)

    Kaufmann, M.; Bosch, H.-S.; Herrmann, A.

    2001-01-01

    In 1997 the new 'LYRA' divertor went into operation at ASDEX Upgrade and the neutral beam heating power was increased to 20 MW by installation of a second injector. This leads to the relatively high value of P/R of 12 MW/m. It has been shown that the ASDEX Upgrade LYRA divertor is capable of handling such high heating powers. Measurements presented in this paper reveal a reduction of the maximum heat flux in the LYRA divertor by more than a factor of two compared to the open Divertor I. This reduction is caused by radiative losses inside the divertor region. Carbon radiation cools the divertor plasma down to a few eV where hydrogen radiation losses become significant. They are increased due to an effective reflection of neutrals into the hot separatrix region. B2-Eirene modelling of the performed experiments supports the experimental findings and refines the understanding of loss processes in the divertor region. (and others)

  7. The LYRA Instrument Onboard PROBA2: Description and In-Flight Performance

    Science.gov (United States)

    Dominique, M.; Hochedez, J.-F.; Schmutz, W.; Dammasch, I. E.; Shapiro, A. I.; Kretzschmar, M.; Zhukov, A. N.; Gillotay, D.; Stockman, Y.; BenMoussa, A.

    2013-08-01

    The Large Yield Radiometer (LYRA) is an XUV-EUV-MUV (soft X-ray to mid-ultraviolet) solar radiometer onboard the European Space Agency Project for On-Board Autonomy 2 (PROBA2) mission, which was launched in November 2009. LYRA acquires solar-irradiance measurements at a high cadence (nominally 20 Hz) in four broad spectral channels, from soft X-ray to MUV, which have been chosen for their relevance to solar physics, space weather, and aeronomy. We briefly review the design of the instrument, give an overview of the data products distributed through the instrument website, and describe how the data are calibrated. We also briefly present a summary of the main fields of research currently under investigation by the LYRA consortium.

  8. Dietary preference and feeding selectivity of common dragonet Callionymus lyra in U.K.

    Science.gov (United States)

    Griffin, R; Pearce, B; Handy, R D

    2012-08-01

    The gut contents of 90 individuals of common dragonet Callionymus lyra were analysed, of which 76 contained prey, along with 100 corresponding benthic grab samples in order to assess the diet of C. lyra in relation to the availability of its prey in the environment. Forty-five prey taxa were identified in the diet from 350 potential prey taxa identified in the environment. Calculation of the index of relative importance (I(RI)) found the main food components were crustaceans (%I(RI) = 86·3), mostly the porcelain crab Pisidia longicornis (%I(RI) = 43) and other decapods (%I(RI) = 18). Polychaetes played only a supplementary role in the overall diet (%I(RI) = 12·5). This study demonstrated that C. lyra is predominantly an opportunistic feeder that can modify its feeding behaviour to exploit alternative, more abundant prey. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

  9. Discovery of a new Wolf-Rayet star using SAGE-LMC

    OpenAIRE

    Gvaramadze, V. V.; Chené, A. -N.; Kniazev, A. Y.; Schnurr, O.

    2011-01-01

    We report the first-ever discovery of an extragalactic Wolf-Rayet (WR)star with Spitzer. A new WR star in the Large Magellanic Cloud (LMC) was revealed via detection of its circumstellar shell using 24 {\\mu}m images obtained in the framework of the Spitzer Survey of the Large Magellanic Cloud (SAGE-LMC). Subsequent spectroscopic bservations with the Gemini South resolved the central star in two components, one of which is a WN3b+abs star, while the second one is a B0V star. We consider the lo...

  10. Spectrophotometric observations of very low ionization HII regions in the LMC

    International Nuclear Information System (INIS)

    Pena, M.; Ruiz, M.T.; Rubio, M.

    1987-01-01

    Optical spectrophotometric observations of 17 very low ionization HII regions of the LMC are reported. Physical conditions and chemical composition of these objects are derived from the emission line intensities. The average chemical abundances obtained are: log O/H=8.49+-0.08, log N/H=6.91+-0.07 and log S/H=6.89+-0.10. We do not find evidence of any composition gradient in the LMC. The HII regions in the vicinity of the detected molecular cloud complexes show higher nebular reddening. (Author)

  11. VizieR Online Data Catalog: Star clusters automatically detected in the LMC (Bitsakis+, 2017)

    Science.gov (United States)

    Bitsakis, T.; Bonfini, P.; Gonzalez-Lopezlira, R. A.; Ramirez-Siordia, V. H.; Bruzual, G.; Charlot, S.; Maravelias, G.; Zaritsky, D.

    2018-03-01

    The archival data used in this work were acquired from several diverse large surveys, which mapped the Magellanic Clouds at various bands. Simons+ (2014AdSpR..53..939S) composed a mosaic using archival data from the Galaxy Evolution Explorer (GALEX) at the near-ultraviolet (NUV) band (λeff=2275Å). The mosaic covers an area of 15deg2 on the LMC. the central ~3x1deg2 of the LMC (the bar-region) was later observed by the Swift Ultraviolet-Optical Telescope (UVOT) Magellanic Clouds Survey (SUMAC; Siegel+ 2014AJ....148..131S). The optical data used here are from the Magellanic Cloud Photometric Survey (MCPS; Zaritsky+ 2004, J/AJ/128/1606). These authors observed the central 64deg2 of the LMC with 3.8-5.2 minute exposures at the Johnson U, B, V, and Gunn i filters of the Las Campanas Swope Telescope. Meixner+ (2006, J/AJ/132/2268) performed a uniform and unbiased imaging survey of the LMC (called Surveying the Agents of a Galaxy's Evolution, or SAGE), covering the central 7deg2 with both the Infrared Array Camera (IRAC) and the Multiband Imaging Photometer (MIPS) on-board the Spitzer Space Telescope. (1 data file).

  12. Spectral Properties of the X-ray Binary Pulsar LMC X-4 during ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    S. Naik & B. Paul Tata Institute of Fundamental Research, Mumbai, 400 005, India. Abstract. ... in the Large Magellanic Cloud. A spin period of 13.5 s ... In this paper we present the spectral variations of LMC X-4 during the 30.5 day long period ...

  13. New polymorphic microsatellite markers in the greater false vampire bat Megaderma lyra (Chiroptera: Megadermatidae)

    Czech Academy of Sciences Publication Activity Database

    Tereba, A.; Čížková, Dagmar; Sundari, A. A.; Rajan, K. E.; Bogdanowicz, W.

    2011-01-01

    Roč. 3, č. 4 (2011), s. 749-751 ISSN 1877-7252 Institutional research plan: CEZ:AV0Z60930519 Keywords : Chiroptera * Megaderma lyra * Microsatellites * Polymorphism Subject RIV: EG - Zoology Impact factor: 0.485, year: 2011

  14. Scrape-off layer radiation and heat load to the ASDEX Upgrade LYRA divertor

    International Nuclear Information System (INIS)

    Kallenbach, A.; Kaufmann, M.; Coster, D.P.

    1999-01-01

    In 1997 the new 'LYRA' divertor went into operation at ASDEX Upgrade and, in parallel, the neutral beam heating power was increased to 20 MW by installation of a second injector leading to a P/R value of 12 MW/m. Experiments have shown that the ASDEX Upgrade LYRA divertor is capable of handling such high heating powers. There is an overall reduction of the maximum heat flux in the LYRA divertor by about a factor of 2 compared with the previous open divertor Div I. This reduction is mainly due to increased radiative losses inside the divertor region, which are caused by an effective reflection of hydrogen neutrals into the hot separatrix region. The main channel of radiative loss is carbon radiation, which cools the divertor plasma down to a few electronvolts, where hydrogen radiation losses become significant. The radiative losses preferentially reduce the power flux at the separatrix, leading to early detachment around the strike point position. With increasing density, the detached region extends upwards on the vertical target. The power fraction radiated in the LYRA divertor is around 45% and nearly independent of the heating power. This value is a factor of 2 higher than the typical radiation fraction in Div I. B2-EIRENE modelling of the performed experiments supports the experimental finding and refines the understanding of loss processes in the divertor region. (author)

  15. VizieR Online Data Catalog: LMC PNe multiwavelength photometry (Reid, 2014)

    Science.gov (United States)

    Reid, W. A.

    2017-07-01

    Using the 2MASS 6x catalogue for the LMC (Cutri et al. 2003, Cat. II/246; 2012, Cat. VII/233), magnitudes were obtained for 274 PNe in J, 269 in H and 263 in Ks. To increase the number of detections available for comparison, magnitudes were also obtained from the InfraRed Survey Facility (IRSF) Magellanic Clouds Point Source Catalogue (Kato et al., 2007, Cat. II/288). The 3.6, 4.5, 5.8 and 8um bands were obtained with the IRAC on board Spitzer. This study used the archival data from the Spitzer legacy programme SAGE (Meixner et al., 2006, Cat. J/AJ/132/2268) which mapped the central 7x7deg2 area of the LMC. The MIPS data were also obtained from both the Hora et al. (2008, Cat. J/AJ/135/726) and Gruendl & Chu (2009, Cat. J/ApJS/184/172) studies. (3 data files).

  16. VizieR Online Data Catalog: LMC NIR Synoptic Survey. II. Wesenheit relations (Bhardwaj+, 2016)

    Science.gov (United States)

    Bhardwaj, A.; Kanbur, S. M.; Macri, L. M.; Singh, H. P.; Ngeow, C.-C.; Wagner-Kaiser, R.; Sarajedini, A.

    2018-03-01

    We make use of NIR mean magnitudes for 775 fundamental-mode and 474 first-overtone Cepheids in the LMC from Macri et al. 2015, J/AJ/149/117 (Paper I). These magnitudes are based on observations from a synoptic survey (average of 16 epochs) of the central region of the LMC using the CPAPIR camera at the Cerro Tololo Interamerican Observatory 1.5-m telescope between 2006 and 2007. Most of these Cepheid variables were previously studied in the optical V and I bands by the third phase of the Optical Gravitational Lensing Experiment (OGLE-III) survey (Soszynski et al. 2008, J/AcA/58/163; Ulaczyk et al. 2013, J/AcA/63/159). The V and I band mean magnitudes are also compiled in Paper I. The calibration into the 2MASS photometric system, extinction corrections, and the adopted reddening law are discussed in detail in Paper I. (4 data files).

  17. Discovery of a New Wolf-Rayet Star Using SAGE-LMC

    Science.gov (United States)

    Gvaramadze, V. V.; Chené, A.-N.; Kniazev, A. Y.; Schnurr, O.

    2012-12-01

    We report the first-ever discovery of an extragalactic Wolf-Rayet (WR) star with Spitzer. A new WR star in the Large Magellanic Cloud (LMC) was revealed via detection of its circumstellar shell using 24 μm images obtained in the framework of the Spitzer Survey of the Large Magellanic Cloud (SAGE-LMC). Subsequent spectroscopic observations with the Gemini South resolved the central star in two components, one of which is a WN3b+abs star, while the second one is a B0 V star. We consider the lopsided brightness distribution over the circumstellar shell as an indication that the WR star is a runaway and use this interpretation to identify a possible parent cluster of the star.

  18. A D'-type symbiotic binary in the planetary nebula SMP LMC 88

    Science.gov (United States)

    Iłkiewicz, Krystian; Mikołajewska, Joanna; Miszalski, Brent; Kozłowski, Szymon; Udalski, Andrzej

    2018-05-01

    SMP LMC 88 is one of the planetary nebulae (PNe) in the Large Magellanic Cloud. We identify in its spectrum Raman scattered O VI lines at 6825 and 7083 Å. This unambiguously classifies the central object of the nebula as a symbiotic star (SySt). We identified the cold component to be a K-type giant, making this the first D'-type (yellow) SySt discovered outside the Galaxy. The photometric variability in SMP LMC 88 resembles the orbital variability of Galactic D'-type SySt with its low amplitude and sinusoidal light-curve shape. The SySt classification is also supported by the He I diagnostic diagram.

  19. H/He ratios for WN stars in the LMC and the galaxy

    International Nuclear Information System (INIS)

    Perry, D.N.; Conti, P.S.

    1982-01-01

    In the visible, most of the He II lines of WR stars are due to the Pickering series (n-4). Though there are significant problems with using the Pickering decrement the authors have utilized it to find H/He ratios for 21 WN stars in the LMC, and 38 stars in the Galaxy. They have additionally extended the analysis to include the derivation of the H/He ratio if the lines are optically thick. (Auth.)

  20. A new ejecta shell surrounding a Wolf-Rayet star in the LMC

    Science.gov (United States)

    Garnett, Donald R.; Chu, You-Hua

    1994-01-01

    We have obtained CCD spectra of newly discovered shell-like nebulae around the WN4 star Breysacher 13 and the WN1 star Breysacher 2 in the Large Magellanic Cloud (LMC). The shell around Br 13 shows definite signs of enrichment in both nitrogen and helium, having much stronger (N II) and He I emission lines than are seen in typical LMC H II regions. From the measured electron temperature of about 17,000 K in the shell, we derive He/H and N/O abundance ratios which are factors of 2 and more than 10 higher, respectively, than the average LMC interstellar values. The derived oxygen abundance in the Br 13 shell is down by a factor of 8 compared to the local LMC interstellar medium (ISM); however, the derived electron temperature is affected by the presence of an incomplete shock arising from the interaction of the stellar wind with photoionized material. This uncertainty does not affect the basic conclusion that the Br 13 shell is enriched by processed material from the Wolf-Rayet star. In contrast, the shell around Br 2 shows no clear evidence of enrichment. The nebular spectrum is characterized by extremely strong (O III) and He II emission and very weak (N II). We derive normal He, O, and N abundances from our spectrum. This object therefore appears to be simply a wind-blown structure associated with a relatively dense cloud near the Wolf-Rayet star, although the very high-ionization state of the gas is unusual for a nebula associated with a Wolf-Rayet star.

  1. Changes in the Long-Term Intensity Variations in Cygnus X-2 and LMC X-3

    Science.gov (United States)

    Paul, B.; Kitamoto, S.; Makino, F.

    2000-01-01

    We report the detection of changes in the long-term intensity variations in two X-ray binaries, Cyg X-2 and LMC X-3. In this work, we have used the long-term light curves obtained with the All-Sky Monitors (ASMs) of the Rossi X-Ray Timing Explorer (RXTE), Ginga, Ariel 5, and Vela 5B and the scanning modulation collimator of HEAO 1. It is found that in the light curves of both the sources, obtained with these instruments at various times over the last 30 years, more than one periodic or quasi-periodic component is always present. The multiple prominent peaks in the periodograms have frequencies unrelated to each other. In Cyg X-2, RXTE-ASM data show strong peaks at 40.4 and 68.8 days, and Ginga-ASM data show strong peaks at 53.7 and 61.3 days. Multiple peaks are also observed in LMC X-3. The various strong peaks in the periodograms of LMC X-3 appear at 104, 169, and 216 days (observed with RXTE-ASM) and 105, 214, and 328 days (observed with Ginga-ASM). The present results, when compared with the earlier observations of periodicities in these two systems, demonstrate the absence of any stable long period. The 78 day periodicity detected earlier in Cyg X-2 was probably due to the short time base in the RXTE data that were used, and the periodicity of 198 days in LMC X-3 was due to a relatively short duration of observation with HEAO 1.

  2. Detection of a Very Bright Source Close to the LMC Supernova SN 1987A: Erratum

    Science.gov (United States)

    Nisenson, P.; Papaliolios, C.; Karovska, M.; Noyes, R.

    1988-01-01

    In the Letter "Detection of a Very Bright Source Close to the LMC Supernova SN 1987A" by P. Nisenson, C. Papaliolios, M. Karovska, and R. Noyes (1987 Ap. J. [Letters], 320, L15), two of the figure labels for Figure 1 were inadvertently transposed in the production process. A corrected version of the figure appears as Plate L4. The Journal regrets the error.

  3. LM1-64: a Newly Reported Lmc-Pn with WR Nucleus

    Science.gov (United States)

    Pena, M.; Olguin, L.; Ruiz, M. T.; Torres-Peimbert, S.

    1993-05-01

    The object LM1-64 was reported by Lindsay & Mullan (1963, Irish Astron. J., 5, 51) as a probable PN in the LMC. Optical and UV spectra taken by us confirm that suggestion. LM1-64 is a high excitation planetary nebulae which shows evidence of having a WC central star. Broad stellar emission at lambda 4650 is detected in the optical spectrum obtained with the CTIO 4m telescope, in 1989. A UV spectrum in the range from 1200 Angstroms to 2000 Angstroms was obtained with IUE in 1990. We have measured all the emission line fluxes available and determined values for the physical conditions and chemical abundances of the nebular ionized gas. The derived values are T(OIII) = 14000K, log He/H = 11.05, log C/H = 9.48, log O/H = 8.55 and log Ne/H = 7.94. LM1-64 shows a large C enhancement in the envelope as result of the central star activity, while He, O and Ne are comparable to the average values reported for the LMC-PNe (Monk, Barlow & Clegg, 1988, MNRAS, 234, 583). We have estimated the He II Zanstra temperature of the central star to be ~ 80,000 K. This temperature is much higher than the values reported for the known LMC-PNe with WR nucleus that Monk et al. have classified as W4 to W8. The only other high temperature WR nucleus in a LMC-PN is N66 which recently showed evidence of undergoing a WR episode (Torres-Peimbert, Ruiz, Peimbert & Pe\\ na, 1993, IAU Symp. 155, eds. A. Acker & R. Weinberger, in press).

  4. NESDIS Blended Rain Rate (RR) Products

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The blended Rain Rate (RR) product is derived from multiple sensors/satellites. The blended products were merged from polar-orbiting and geostationary satellite...

  5. The Outer Halo of the Milky Way as Probed by RR Lyr Variables from the Palomar Transient Facility

    Science.gov (United States)

    Cohen, Judith G.; Sesar, Branimir; Bahnolzer, Sophianna; He, Kevin; Kulkarni, Shrinivas R.; Prince, Thomas A.; Bellm, Eric; Laher, Russ R.

    2017-11-01

    RR Lyrae stars are ideal massless tracers that can be used to study the total mass and dark matter content of the outer halo of the Milky Way (MW). This is because they are easy to find in the light-curve databases of large stellar surveys and their distances can be determined with only knowledge of the light curve. We present here a sample of 112 RR Lyr stars beyond 50 kpc in the outer halo of the MW, excluding the Sgr streams, for which we have obtained moderate-resolution spectra with Deimos on the Keck II Telescope. Four of these have distances exceeding 100 kpc. These were selected from a much larger set of 447 candidate RR Lyr stars that were data-mined using machine-learning techniques applied to the light curves of variable stars in the Palomar Transient Facility database. The observed radial velocities taken at the phase of the variable corresponding to the time of observation were converted to systemic radial velocities in the Galactic standard of rest. From our sample of 112 RR Lyr stars we determine the radial velocity dispersion in the outer halo of the MW to be ˜90 km s-1 at 50 kpc, falling to about 65 km s-1 near 100 kpc once a small number of major outliers are removed. With reasonable estimates of the completeness of our sample of 447 candidates and assuming a spherical halo, we find that the stellar density in the outer halo declines as {r}-4. Based in part on observations obtained at the W. M. Keck Observatory, which is operated jointly by the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration.

  6. CCD photometry in the Vilnius photometric system. I. region in Lyra

    International Nuclear Information System (INIS)

    Boyle, R.P.; Smriglio, F.; Straizys, V.

    1990-01-01

    Three-dimensional photometric classification can be made for stars measured in the Vilnius seven-color intermediate-band system, even if they are reddened by dust. Such classification is important for questions relating to the structure and evolution of our Galaxy. Presented here for general use is CCD photometry of 231 field stars in Lyra observed with the 0.9 meter telescope of Kitt Peak National Observatory. The measurements are of higher accuracy than those of a photographic study in the same direction in Lyra for which they can also be used for a deeper calibration of the photographic photometry. The data sets cover two small fields each about 31 arcmin 2 and are complete to 90% for all stars up to the faint limit of V = 17.5

  7. A preliminary examination of genetic diversity in the Indian false vampire bat Megaderma lyra

    Directory of Open Access Journals (Sweden)

    Emmanuvel Rajan, K.

    2006-12-01

    Full Text Available Habitat loss and fragmentation have serious consequences for species extinction as well as genetic diversity within a species. Random Amplified Polymorphic DNA (RAPD analysis was employed to assess the genetic diversity within and between four natural populations of M. lyra. Our results suggest that the genetic diversity varied from 0.21 to 0.26 with a mean of 0.11 to 0.13 (± SD. The mean Gst value of 0.15 was obtained from all four populations and estimated average Nm (1.41 showing gene flow between the populations. AMOVA analysis showed 88.96% within and 11.04% among the studied populations. Cluster analyses of RAPD phenotypes showed that specimens were not grouped by geographical origin. The genetic diversity found in the M. lyra population may be explained by its breeding behaviors. Though preliminary, the results indicate that all four populations should be considered to maintain the genetic diversity.

  8. Anomalous Low States and Long Term Variability in the Black Hole Binary LMC X-3

    Science.gov (United States)

    Smale, Alan P.; Boyd, Patricia T.

    2012-01-01

    Rossi X-my Timing Explorer observations of the black hole binary LMC X-3 reveal an extended very low X-ray state lasting from 2003 December 13 until 2004 March 18, unprecedented both in terms of its low luminosity (>15 times fainter than ever before seen in this source) and long duration (approx 3 times longer than a typical low/hard state excursion). During this event little to no source variability is observed on timescales of approx hours-weeks, and the X-ray spectrum implies an upper limit of 1.2 x 10(exp 35) erg/s, Five years later another extended low state occurs, lasting from 2008 December 11 until 2009 June 17. This event lasts nearly twice as long as the first, and while significant variability is observed, the source remains reliably in the low/hard spectral state for the approx 188 day duration. These episodes share some characteristics with the "anomalous low states" in the neutron star binary Her X-I. The average period and amplitude of the Variability of LMC X-3 have different values between these episodes. We characterize the long-term variability of LMC X-3 before and after the two events using conventional and nonlinear time series analysis methods, and show that, as is the case in Her X-I, the characteristic amplitude of the variability is related to its characteristic timescale. Furthermore, the relation is in the same direction in both systems. This suggests that a similar mechanism gives rise to the long-term variability, which in the case of Her X-I is reliably modeled with a tilted, warped precessing accretion disk.

  9. Spitzer observations of large amplitude variables in the LMC and IC 1613

    Directory of Open Access Journals (Sweden)

    Whitelock Patricia A.

    2017-01-01

    Full Text Available The 3.6 and 4.5 ìm characteristics of asymptotic giant branch variables in the LMC and IC 1613 are discussed. For C-rich Mira variables there is a very clear periodluminosity-colour relation, where the [3.6] . [4.5] colour is associated with the amount of circumstellar material and correlated with the pulsation amplitude. The [4.5] periodluminosity relation for dusty stars is approximately one mag brighter than for their naked counterparts with comparable periods.

  10. Optical and near-IR study of LMC HII region N11AB

    International Nuclear Information System (INIS)

    Lee, M.G.

    1990-01-01

    N11 (DEM 34), complex HII region located about 4 degrees from the center of the LMC bar, is a very interesting giant interstellar shell. It has a complicated structure and motion. It is located on the edge of an HI concentration. This is the progress report of the study of its two components, A and B at the optical and near-IR wavelengths to investigate stars, dust and ionized gas associated with them. N11A is a compact high-excitation blob and N11B is a bright HII region in this complex, which embeds OB association Lucke-Hodge 10

  11. The mass of the black hole in the X-ray binary LMC X-1

    Science.gov (United States)

    Abubekerov, M. K.; Antokhina, E. A.; Gostev, N. Yu.; Cherepashchuk, A. M.; Shimansky, V. V.

    2016-12-01

    A dynamical estimate of the mass of the black hole in the LMC X-1 binary system is obtained in the framework of a Roche model for the optical star, based on fitting of the He I 4471 Å and He II 4200 Å absorption lines assuming LTE. The mass of the black hole derived from the radial-velocity curve for the He II 4200 Å line is m x = 10.55 M ⊙, close to the value found earlier based on a model with two point bodies [1].

  12. QT/RR Coupling and Gender Differences

    Czech Academy of Sciences Publication Activity Database

    Halámek, Josef; Jurák, Pavel; Lipoldová, J.; Leinveber, Pavel

    2010-01-01

    Roč. 37, - (2010), s. 365-368 ISSN 0276-6574 R&D Projects: GA ČR GA102/08/1129 Institutional research plan: CEZ:AV0Z20650511 Keywords : THEW * QT/RR model * EXPDC Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering http://cinc.mit.edu/archives/2010/pdf/0365.pdf

  13. PROTOTYPING NON-EQUILIBRIUM VISCOUS-TIMESCALE ACCRETION THEORY USING LMC X-3

    Energy Technology Data Exchange (ETDEWEB)

    Cambier, Hal J.; Smith, David M. [Physics Department, University of California, Santa Cruz, CA 95064 (United States)

    2013-04-10

    Explaining variability observed in the accretion flows of black hole X-ray binary systems remains challenging, especially concerning timescales less than, or comparable to, the viscous timescale but much larger than the inner orbital period despite decades of research identifying numerous relevant physical mechanisms. We take a simplified but broad approach to study several mechanisms likely relevant to patterns of variability observed in the persistently high-soft Roche-lobe overflow system LMC X-3. Based on simple estimates and upper bounds, we find that physics beyond varying disk/corona bifurcation at the disk edge, Compton-heated winds, modulation of total supply rate via irradiation of the companion, and the likely extent of the partial hydrogen ionization instability is needed to explain the degree, and especially the pattern, of variability in LMC X-3 largely due to viscous dampening. We then show how evaporation-condensation may resolve or compound the problem given the uncertainties associated with this complex mechanism and our current implementation. We briefly mention our plans to resolve the question, refine and extend our model, and alternatives we have not yet explored.

  14. APSIDAL MOTION AND A LIGHT CURVE SOLUTION FOR 13 LMC ECCENTRIC ECLIPSING BINARIES

    Energy Technology Data Exchange (ETDEWEB)

    Zasche, P.; Wolf, M.; Vraštil, J.; Pilarcik, L. [Astronomical Institute, Charles University in Prague, Faculty of Mathematics and Physics, CZ-180 00 Praha 8, V Holešovičkách 2 (Czech Republic)

    2015-12-15

    New CCD observations for 13 eccentric eclipsing binaries from the Large Magellanic Cloud were carried out using the Danish 1.54 m telescope located at the La Silla Observatory in Chile. These systems were observed for their times of minimum and 56 new minima were obtained. These are needed for accurate determination of the apsidal motion. Besides that, in total 436 times of minimum were derived from the photometric databases OGLE and MACHO. The O – C diagrams of minimum timings for these B-type binaries were analyzed and the parameters of the apsidal motion were computed. The light curves of these systems were fitted using the program PHOEBE, giving the light curve parameters. We derived for the first time relatively short periods of the apsidal motion ranging from 21 to 107 years. The system OGLE-LMC-ECL-07902 was also analyzed using the spectra and radial velocities, resulting in masses of 6.8 and 4.4 M{sub ⊙} for the eclipsing components. For one system (OGLE-LMC-ECL-20112), the third-body hypothesis was also used to describe the residuals after subtraction of the apsidal motion, resulting in a period of about 22 years. For several systems an additional third light was also detected, which makes these systems suspect for triplicity.

  15. The Nature and Cause of Spectral Variability in LMC X-1

    Science.gov (United States)

    Ruhlen, L.; Smith, D. M.; Scank, J. H.

    2011-01-01

    We present the results of a long-term observation campaign of the extragalactic wind-accreting black-hole X-ray binary LMC X-1, using the Proportional Counter Array on the Rossi X-Ray Timing Explorer (RXTE). The observations show that LMC X-1's accretion disk exhibits an anomalous temperature-luminosity relation. We use deep archival RXTE observations to show that large movements across the temperature-luminosity space occupied by the system can take place on time scales as short as half an hour. These changes cannot be adequately explained by perturbations that propagate from the outer disk on a viscous timescale. We propose instead that the apparent disk variations reflect rapid fluctuations within the Compton up-scattering coronal material, which occults the inner parts of the disk. The expected relationship between the observed disk luminosity and apparent disk temperature derived from the variable occultation model is quantitatively shown to be in good agreement with the observations. Two other observations support this picture: an inverse correlation between the flux in the power-law spectral component and the fitted inner disk temperature, and a near-constant total photon flux, suggesting that the inner disk is not ejected when a lower temperature is observed.

  16. LRS Bianchi Type II Massive String Cosmological Models with Magnetic Field in Lyra's Geometry

    Directory of Open Access Journals (Sweden)

    Raj Bali

    2013-01-01

    Full Text Available Bianchi type II massive string cosmological models with magnetic field and time dependent gauge function ( in the frame work of Lyra's geometry are investigated. The magnetic field is in -plane. To get the deterministic solution, we have assumed that the shear ( is proportional to the expansion (. This leads to , where and are metric potentials and is a constant. We find that the models start with a big bang at initial singularity and expansion decreases due to lapse of time. The anisotropy is maintained throughout but the model isotropizes when . The physical and geometrical aspects of the model in the presence and absence of magnetic field are also discussed.

  17. Black Holes with Anisotropic Fluid in Lyra Scalar-Tensor Theory

    Directory of Open Access Journals (Sweden)

    Melis ULU DOĞRU

    2018-02-01

    Full Text Available In this paper, we investigate distribution of anisotropic fluid which is a resource of black holes in regard to Lyra scalar-tensor theory. As part of the theory, we obtain field equations of spherically symmetric space-time with anisotropic fluid. By using field equations, we suggest distribution of anisotropic fluid, responsible for space-time geometries such as Schwarzschild, Reissner-Nordström, Minkowski type, de Sitter type, Anti-de Sitter type, BTZ and charged BTZ black holes. Finally, we discuss obtained pressures and density of the fluid for different values of arbitrary constants, geometrically and physically.

  18. NEW OPTICAL REDDENING MAPS OF THE LARGE AND SMALL MAGELLANIC CLOUDS

    International Nuclear Information System (INIS)

    Haschke, Raoul; Grebel, Eva K.; Duffau, Sonia

    2011-01-01

    We present new reddening maps of the Small Magellanic Cloud (SMC) and Large Magellanic Cloud (LMC) based on the data of the third phase of the Optical Gravitational Lensing Experiment (OGLE III). We have used two different methods to derive optical reddening maps. We adopt a theoretical mean unreddened color for the red clump (RC) in the SMC and LMC, respectively. We subdivide the photometric data for both Clouds into subfields and calculate the difference between the observed RC position and the theoretical value for each field, which provides us with the reddening value in (V - I). Furthermore, reddening values are obtained for 13490 LMC RR Lyrae ab and 1529 SMC RR Lyrae ab stars covering the whole OGLE III region of the Magellanic Clouds (MCs). The observed colors (V - I) of the RR Lyrae stars are compared with the color from the absolute magnitudes. The absolute magnitude of each RR Lyrae star is computed using its period and metallicity derived from Fourier decomposition of its light curve. In general, we find a low and uniform reddening distribution in both MCs. The RC method indicates a mean reddening of the LMC of E(V - I) = 0.09 ± 0.07 mag, while for the SMC E(V - I) = 0.04 ± 0.06 mag is obtained. With RR Lyrae stars a median value of E(V - I) = 0.11 ± 0.06 mag for the LMC and E(V - I) = 0.07 ± 0.06 mag for the SMC is found. The LMC shows very low reddening in the bar region, whereas the reddening in the star-forming leading edge and 30 Doradus is considerably higher. In the SMC, three pronounced regions with higher reddening are visible. Two are located along the bar, while the highest reddening is found in the star-forming wing of the SMC. In general, the regions with higher reddening are in good spatial agreement with infrared reddening maps as well as with reddening estimations of other studies. The position-dependent reddening values from the RC method are available via the German Astrophysical Virtual Observatory interface.

  19. Optical spectrophotometric atlas of Supernova 1987A in the LMC. I. The first 130 days

    International Nuclear Information System (INIS)

    Phillips, M.M.; Heathcote, S.R.; Hamuy, M.; Navarrete, M.

    1988-01-01

    Optical spectrophotometry of SN 1987A in the Large Magellanic Cloud (LMC) covering the first 5 months since outburst is presented. More than 80 spectra were obtained at Cerro Tololo over this period, mostly with the 2D-Frutti two-dimensional photon-counting detector on the 1-m telescope. The spectrophotometric calibration of the 2D-Frutti data is considered in detail. Through a comparison with broadband photometry, it is shown that the accuracy of the 2D-Frutti spectrophotometry is + or - 5 percent in absolute terms, and that the relative calibration for any single spectrum is accurate to + or - 3 percent. CCD spectrophotometry obtained on the first night of observation (Feb. 25, 1987) is also briefly discussed. Radial velocities for several prominent absorption and emission features are measured from these combined data. 13 references

  20. NGC 1866: First Spectroscopic Detection of Fast-rotating Stars in a Young LMC Cluster

    Energy Technology Data Exchange (ETDEWEB)

    Dupree, A. K.; Dotter, A.; Johnson, C. I. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Marino, A. F.; Milone, A. P. [Australian National University, The Research School of Astronomy and Astrophysics, Mount Stromlo Observatory, Weston Creek, ACT 2611 (Australia); Bailey, J. I. III [Leiden Observatory, Niels Bohrweg 2, NL-2333 CA Leiden (Netherlands); Crane, J. D. [The Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Mateo, M. [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States); Olszewski, E. W. [The University of Arizona, 933 N. Cherry Avenue, Tucson, AZ 85721 (United States)

    2017-09-01

    High-resolution spectroscopic observations were taken of 29 extended main-sequence turnoff (eMSTO) stars in the young (∼200 Myr) Large Magellanic Cloud (LMC) cluster, NGC 1866, using the Michigan/ Magellan Fiber System and MSpec spectrograph on the Magellan -Clay 6.5 m telescope. These spectra reveal the first direct detection of rapidly rotating stars whose presence has only been inferred from photometric studies. The eMSTO stars exhibit H α emission (indicative of Be-star decretion disks), others have shallow broad H α absorption (consistent with rotation ≳150 km s{sup −1}), or deep H α core absorption signaling lower rotation velocities (≲150 km s{sup −1}). The spectra appear consistent with two populations of stars—one rapidly rotating, and the other, younger and slowly rotating.

  1. QT/RR hysteresis as a function of RR excitation – implications for risk

    Czech Academy of Sciences Publication Activity Database

    Halámek, Josef; Jurák, Pavel; Somers, V. K.; Nykodým, J.; Leinveber, P.; Fráňa, P.; Eisenberger, M.; Kára, T.

    2005-01-01

    Roč. 4, č. 1 (2005), s. 98 [World Congress on Heart Disease - New Trends in Research, Diagnosis and Treatment /12./. 16.07.2005-19.07.2005, Vancouver] Institutional research plan: CEZ:AV0Z20650511 Keywords : ventricular repolarization * RR intervals Subject RIV: FA - Cardiovascular Disease s incl. Cardiotharic Surgery

  2. Anisotropic Bianchi Type-III Bulk Viscous Fluid Universe in Lyra Geometry

    Directory of Open Access Journals (Sweden)

    Priyanka Kumari

    2013-01-01

    Full Text Available An anisotropic Bianchi type-III cosmological model is investigated in the presence of a bulk viscous fluid within the framework of Lyra geometry with time-dependent displacement vector. It is shown that the field equations are solvable for any arbitrary function of a scale factor. To get the deterministic model of the universe, we have assumed that (i a simple power-law form of a scale factor and (ii the bulk viscosity coefficient are proportional to the energy density of the matter. The exact solutions of the Einstein’s field equations are obtained which represent an expanding, shearing, and decelerating model of the universe. Some physical and kinematical behaviors of the cosmological model are briefly discussed.

  3. Pressure drop in ET-RR-1

    International Nuclear Information System (INIS)

    Khattab, M.; Mina, A.R.

    1990-01-01

    Measurements of pressure drop through a bundle comprising 16 rods and their lower arrangement grid as well as orifices similar to those of ET-RR-1 core have been done. Experiments are carried out under adiabatic turbulent flow conditions at about 35 degree C. Bundle Reynolds number range is 4 x 10 -2 x 10. Orifices of diameters 4.5, 3.25 or 2.5 cm. are mounted underneath the bundle. The bundle and lower grid pressure drop coefficients are 3.75 and 1.8 respectively. Orifices pressure drop coefficients are 2.65, 19.67 and 53.55 respectively. The ratio of bundle pressure drop to that of 4.5 cm. Orifice diameter is 1.415. The pressure drop coefficients are utilizer to calculate flow through bundles. The flow rate per bundle is 39.1, 20.4 or 13.1 m 3 /hr. Depending on orifice diameter

  4. OGLE-LMC-ECL-11893: The discovery of a long-period eclipsing binary with a circumstellar disk

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Subo [Kavli Institute for Astronomy and Astrophysics, Peking University, Yi He Yuan Road 5, Hai Dian District, Beijing 100871 (China); Katz, Boaz [Institute for Advanced Study, 1 Einstein Drive, Princeton, NJ 08544 (United States); Prieto, Jose L. [Department of Astrophysical Sciences, Princeton University, 4 Ivy Lane, Peyton Hall, Princeton, NJ 08544 (United States); Udalski, Andrzej; Kozlowski, Szymon [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland); Street, R. A.; Tsapras, Y. [Las Cumbres Observatory Global Telescope Network, 6740 Cortona Drive, suite 102, Goleta, CA 93117 (United States); Bramich, D. M. [Qatar Environment and Energy Research Institute, Qatar Foundation, Tornado Tower, Floor 19, P.O. Box 5825, Doha (Qatar); Hundertmark, M.; Horne, K.; Dominik, M.; Jaimes, R. Figuera [SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews KY16 9SS (United Kingdom); Snodgrass, C. [Max Planck Institute for Solar System Research, Justus-von-Liebig-Weg 3, D-37077 Göttingen (Germany)

    2014-06-10

    We report the serendipitous discovery of a disk-eclipse system OGLE-LMC-ECL-11893. The eclipse occurs with a period of 468 days, a duration of about 15 days, and a deep (up to Δm{sub I} ≈ 1.5), peculiar, and asymmetric profile. A possible origin of such an eclipse profile involves a circumstellar disk. The presence of the disk is confirmed by the H-α line profile from the follow-up spectroscopic observations, and the star is identified as Be/Ae type. Unlike the previously known disk-eclipse candidates, the eclipses of OGLE-LMC-ECL-11893 retain the same shape throughout the span of ∼17 yr (13 orbital periods), indicating no measurable orbital precession of the disk.

  5. Multifrequency radio observations of a SNR in the LMC: The case of SNR J0527-6549 (DEM l204

    Directory of Open Access Journals (Sweden)

    Bozzetto L.M.

    2010-01-01

    Full Text Available We present a detailed study and results of new Australia Telescope Compact Array (ATCA observations of supernova remnant SNR J0527-6549. This Large Magellanic Cloud (LMC object follows a typical supernova remnant (SNR horseshoe morphology with a diameter of D=(66×58±1 pc which is among the largest SNRs in the LMC. Its relatively large size indicates older age while a steeper than expected radio spectral index of α=-0.92±0.11 is more typical of younger and energetic SNRs. Also, we report detections of regions with a high order of polarization at a peak value of ~54%±17% at 6 cm.

  6. Identification of two new HMXBs in the LMC: an ˜2013 s pulsar and a probable SFXT

    Science.gov (United States)

    Vasilopoulos, G.; Maitra, C.; Haberl, F.; Hatzidimitriou, D.; Petropoulou, M.

    2018-03-01

    We report on the X-ray and optical properties of two high-mass X-ray binary systems located in the Large Magellanic Cloud (LMC). Based on the obtained optical spectra, we classify the massive companion as a supergiant star in both systems. Timing analysis of the X-ray events collected by XMM-Newton revealed the presence of coherent pulsations (spin period ˜2013 s) for XMMU J053108.3-690923 and fast flaring behaviour for XMMU J053320.8-684122. The X-ray spectra of both systems can be modelled sufficiently well by an absorbed power law, yielding hard spectra and high intrinsic absorption from the environment of the systems. Due to their combined X-ray and optical properties, we classify both systems as SgXRBs: the 19th confirmed X-ray pulsar and a probable supergiant fast X-ray transient in the LMC, the second such candidate outside our Galaxy.

  7. Detection of variable VHE γ-ray emission from the extra-galactic γ-ray binary LMC P3

    Science.gov (United States)

    HESS Collaboration; Abdalla, H.; Abramowski, A.; Aharonian, F.; Ait Benkhali, F.; Angüner, E. O.; Arakawa, M.; Armand, C.; Arrieta, M.; Backes, M.; Balzer, A.; Barnard, M.; Becherini, Y.; Becker Tjus, J.; Berge, D.; Bernhard, S.; Bernlöhr, K.; Blackwell, R.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bonnefoy, S.; Bordas, P.; Bregeon, J.; Brun, F.; Brun, P.; Bryan, M.; Büchele, M.; Bulik, T.; Capasso, M.; Caroff, S.; Carosi, A.; Casanova, S.; Cerruti, M.; Chakraborty, N.; Chaves, R. C. G.; Chen, A.; Chevalier, J.; Colafrancesco, S.; Condon, B.; Conrad, J.; Davids, I. D.; Decock, J.; Deil, C.; Devin, J.; deWilt, P.; Dirson, L.; Djannati-Ataï, A.; Donath, A.; Drury, L. O.'C.; Dyks, J.; Edwards, T.; Egberts, K.; Emery, G.; Ernenwein, J.-P.; Eschbach, S.; Farnier, C.; Fegan, S.; Fernandes, M. V.; Fiasson, A.; Fontaine, G.; Funk, S.; Füßling, M.; Gabici, S.; Gallant, Y. A.; Garrigoux, T.; Gaté, F.; Giavitto, G.; Glawion, D.; Glicenstein, J. F.; Gottschall, D.; Grondin, M.-H.; Hahn, J.; Haupt, M.; Hawkes, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hinton, J. A.; Hofmann, W.; Hoischen, C.; Holch, T. L.; Holler, M.; Horns, D.; Ivascenko, A.; Iwasaki, H.; Jacholkowska, A.; Jamrozy, M.; Jankowsky, D.; Jankowsky, F.; Jingo, M.; Jouvin, L.; Jung-Richardt, I.; Kastendieck, M. A.; Katarzyński, K.; Katsuragawa, M.; Katz, U.; Kerszberg, D.; Khangulyan, D.; Khélifi, B.; King, J.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Komin, Nu.; Kosack, K.; Krakau, S.; Kraus, M.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lau, J.; Lefaucheur, J.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Leser, E.; Lohse, T.; Lorentz, M.; Liu, R.; López-Coto, R.; Lypova, I.; Malyshev, D.; Marandon, V.; Marcowith, A.; Mariaud, C.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; Meintjes, P. J.; Meyer, M.; Mitchell, A. M. W.; Moderski, R.; Mohamed, M.; Mohrmann, L.; Morå, K.; Moulin, E.; Murach, T.; Nakashima, S.; de Naurois, M.; Ndiyavala, H.; Niederwanger, F.; Niemiec, J.; Oakes, L.; O'Brien, P.; Odaka, H.; Ohm, S.; Ostrowski, M.; Oya, I.; Padovani, M.; Panter, M.; Parsons, R. D.; Pekeur, N. W.; Pelletier, G.; Perennes, C.; Petrucci, P.-O.; Peyaud, B.; Piel, Q.; Pita, S.; Poireau, V.; Prokhorov, D. A.; Prokoph, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Rauth, R.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Rinchiuso, L.; Romoli, C.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Saito, S.; Sanchez, D. A.; Santangelo, A.; Sasaki, M.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwemmer, S.; Seglar-Arroyo, M.; Seyffert, A. S.; Shafi, N.; Shilon, I.; Shiningayamwe, K.; Simoni, R.; Sol, H.; Spanier, F.; Spir-Jacob, M.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Steppa, C.; Sushch, I.; Takahashi, T.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tibaldo, L.; Tiziani, D.; Tluczykont, M.; Trichard, C.; Tsirou, M.; Tsuji, N.; Tuffs, R.; Uchiyama, Y.; van der Walt, D. J.; van Eldik, C.; van Rensburg, C.; van Soelen, B.; Vasileiadis, G.; Veh, J.; Venter, C.; Viana, A.; Vincent, P.; Vink, J.; Voisin, F.; Völk, H. J.; Vuillaume, T.; Wadiasingh, Z.; Wagner, S. J.; Wagner, P.; Wagner, R. M.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Yang, R.; Zaborov, D.; Zacharias, M.; Zanin, R.; Zdziarski, A. A.; Zech, A.; Zefi, F.; Ziegler, A.; Zorn, J.; Żywucka, N.

    2018-03-01

    Context. Recently, the high-energy (HE, 0.1-100 GeV) γ-ray emission from the object LMC P3 in the Large Magellanic Cloud (LMC) has been discovered to be modulated with a 10.3-day period, making it the first extra-galactic γ-ray binary. Aim. This work aims at the detection of very-high-energy (VHE, >100 GeV) γ-ray emission and the search for modulation of the VHE signal with the orbital period of the binary system. Methods: LMC P3 has been observed with the High Energy Stereoscopic System (H.E.S.S.); the acceptance-corrected exposure time is 100 h. The data set has been folded with the known orbital period of the system in order to test for variability of the emission. Results: VHE γ-ray emission is detected with a statistical significance of 6.4 σ. The data clearly show variability which is phase-locked to the orbital period of the system. Periodicity cannot be deduced from the H.E.S.S. data set alone. The orbit-averaged luminosity in the 1-10 TeV energy range is (1.4 ± 0.2) × 1035 erg s-1. A luminosity of (5 ± 1) × 1035 erg s-1 is reached during 20% of the orbit. HE and VHE γ-ray emissions are anti-correlated. LMC P3 is the most luminous γ-ray binary known so far.

  8. RR-Interval variance of electrocardiogram for atrial fibrillation detection

    Science.gov (United States)

    Nuryani, N.; Solikhah, M.; Nugoho, A. S.; Afdala, A.; Anzihory, E.

    2016-11-01

    Atrial fibrillation is a serious heart problem originated from the upper chamber of the heart. The common indication of atrial fibrillation is irregularity of R peak-to-R-peak time interval, which is shortly called RR interval. The irregularity could be represented using variance or spread of RR interval. This article presents a system to detect atrial fibrillation using variances. Using clinical data of patients with atrial fibrillation attack, it is shown that the variance of electrocardiographic RR interval are higher during atrial fibrillation, compared to the normal one. Utilizing a simple detection technique and variances of RR intervals, we find a good performance of atrial fibrillation detection.

  9. The Orbital and Physical Parameters, and the Distance of the Eclipsing Binary System OGLE-LMC-ECL-25658 in the Large Magellanic Cloud

    Science.gov (United States)

    Elgueta, S. S.; Graczyk, D.; Gieren, W.; Pietrzyński, G.; Thompson, I. B.; Konorski, P.; Pilecki, B.; Villanova, S.; Udalski, A.; Soszyński, I.; Suchomska, K.; Karczmarek, P.; Górski, M.; Wielgórski, P.

    2016-08-01

    We present an analysis of a new detached eclipsing binary, OGLE-LMC-ECL-25658, in the Large Magellanic Cloud (LMC). The system consists of two late G-type giant stars on an eccentric orbit with an orbital period of ˜200 days. The system shows total eclipses and the components have similar temperatures, making it ideal for a precise distance determination. Using multi-color photometric and high resolution spectroscopic data, we have performed an analysis of light and radial velocity curves simultaneously using the Wilson-Devinney code. We derived orbital and physical parameters of the binary with a high precision of \\lt 1%. The masses and surface metallicities of the components are virtually the same and equal to 2.23+/- 0.02 {M}⊙ and [{Fe}/{{H}}]\\=\\-0.63+/- 0.10 dex. However, their radii and rates of rotation show a distinct trace of differential stellar evolution. The distance to the system was calculated using an infrared calibration between V-band surface brightness and (V-K) color, leading to a distance modulus of (m-M)\\=\\18.452+/- 0.023 (statistical) ± 0.046 (systematic). Because OGLE-LMC-ECL-25658 is located relatively far from the LMC barycenter, we applied a geometrical correction for its position in the LMC disk using the van der Marel et al. model of the LMC. The resulting barycenter distance to the galaxy is {d}{{LMC}}\\=\\50.30+/- 0.53 (stat.) kpc, and is in perfect agreement with the earlier result of Pietrzyński et al.

  10. The Properties of Long Period Variables in the LMC from MACHO

    Energy Technology Data Exchange (ETDEWEB)

    Fraser, O J; Hawley, S L; Cook, K H

    2008-05-06

    We present a new analysis of the long period variables in the Large Magellanic Cloud from the MACHO Variable Star Catalog. Three-quarters of our sample of evolved, variable stars have periodic light curves. We characterize the stars in our sample using the multiple periods found in their frequency spectra. Additionally, we use single-epoch 2MASS measurements to construct the average infrared light curves for different groups of these stars. Comparison with evolutionary models shows that stars on the RGB or the Early AGB often show non-periodic variability, but begin to pulsate with periods on the two shortest period-luminosity sequences (1 & 2) when they brighten to K{sub s} {approx} 13. The stars on the Thermally Pulsing AGB are more likely to pulsate with longer periods that lie on the next two P-L sequences (3 & 4), including the sequence associated with the Miras in the LMC. The Petersen diagram and its variants show that multi-periodic stars on each pair of these sequences (3 & 4, and 1 & 2), typically pulsate with periods associated only with that pair. The periods in these multi-periodic stars become longer and stronger as the star evolves. We further constrain the mechanism behind the long secondary periods (LSPs) seen in half of our sample, and find that there is a close match between the luminosity functions of the LSP stars and all of the stars in our sample, and that these star's pulsation amplitudes are relatively wavelength independent. Although this is characteristic of stellar multiplicity, the large number of these variables is problematic for that explanation.

  11. The Magellanic Analog Dwarf Companions and Stellar Halos (MADCASH) Survey: Near-Field Cosmology with Resolved Stellar Populations Around Local Volume LMC Stellar-Mass Galaxies

    Science.gov (United States)

    Carlin, Jeffrey L.; Sand, David J.; Willman, Beth; Brodie, Jean P.; Crnojevic, Denija; Peter, Annika; Price, Paul A.; Romanowsky, Aaron J.; Spekkens, Kristine; Strader, Jay

    2017-01-01

    We discuss the first results of our observational program to comprehensively map nearly the entire virial volumes of roughly LMC stellar mass galaxies at distances of ~2-4 Mpc. The MADCASH (Magellanic Analog Dwarf Companions And Stellar Halos) survey will deliver the first census of the dwarf satellite populations and stellar halo properties within LMC-like environments in the Local Volume. These will inform our understanding of the recent DES discoveries of dwarf satellites tentatively affiliated with the LMC/SMC system. We will detail our discovery of the faintest known dwarf galaxy satellite of an LMC stellar-mass host beyond the Local Group, based on deep Subaru+HyperSuprimeCam imaging reaching ~2 magnitudes below its TRGB. We will summarize the survey results and status to date, highlighting some challenges encountered and lessons learned as we process the data for this program through a prototype LSST pipeline. Our program will examine whether LMC stellar mass dwarfs have extended stellar halos, allowing us to assess the relative contributions of in-situ stars vs. merger debris to their stellar populations and halo density profiles. We outline the constraints on galaxy formation models that will be provided by our observations of low-mass galaxy halos and their satellites.

  12. Evidence for a perception of prosodic cues in bat communication: contact call classification by Megaderma lyra.

    Science.gov (United States)

    Janssen, Simone; Schmidt, Sabine

    2009-07-01

    The perception of prosodic cues in human speech may be rooted in mechanisms common to mammals. The present study explores to what extent bats use rhythm and frequency, typically carrying prosodic information in human speech, for the classification of communication call series. Using a two-alternative, forced choice procedure, we trained Megaderma lyra to discriminate between synthetic contact call series differing in frequency, rhythm on level of calls and rhythm on level of call series, and measured the classification performance for stimuli differing in only one, or two, of the above parameters. A comparison with predictions from models based on one, combinations of two, or all, parameters revealed that the bats based their decision predominantly on frequency and in addition on rhythm on the level of call series, whereas rhythm on level of calls was not taken into account in this paradigm. Moreover, frequency and rhythm on the level of call series were evaluated independently. Our results show that parameters corresponding to prosodic cues in human languages are perceived and evaluated by bats. Thus, these necessary prerequisites for a communication via prosodic structures in mammals have evolved far before human speech.

  13. LYRA and other projects on RPV steel embrittlement study and mitigation of the AMES network

    International Nuclear Information System (INIS)

    Debarberis, L.; Estorff, U. von; Crutzen, S.; Beers, M.; Stamm, H.; Vries, M.I. de; Tjoa, G.L.

    1998-01-01

    Within the framework of the European Network AMES, Ageing Materials evaluation and Studies, a number of experimental works on RPV materials embrittlement are carried out at the Institute of Advanced Materials (AIM) of the Joint Research Centre (JRC) of the European Commission (EC). The objectives of AMES are mainly the understanding of the property degradation phenomena of RPV western reference steels like JRQ and HSST, eastern RPV steels like 15X2mFA and 15H2X15, and annealing possibilities. In order to conduct a very high quality irradiation rig, LYRA facility, has been designed and developed at the High Flux Reactor (HFR) Petten. An other dedicated rig, named LIMA, has been developed at the HFR Petten in order to irradiate RPV steels, internals and in-core materials under typical BWR/PWR conditions. The samples can be irradiated in pressurised water up to 160 bar, 320 deg. C, and the water chemistry fully controlled. For irradiation of standard or miniaturised LWR related materials samples, another group of well experienced irradiation devices with inert gas or liquid metals environment are employed. These devices are tailored to their various specific applications. This paper is intended to give information about the structure and the objectives of the existing European network AMES, and to present the various AMES main and spin-off projects, including a brief description on he modelling activities related to RPV materials embrittlement. (author)

  14. Hitomi observations of the LMC SNR N 132 D: Highly redshifted X-ray emission from iron ejecta

    Science.gov (United States)

    Hitomi Collaboration; Aharonian, Felix; Akamatsu, Hiroki; Akimoto, Fumie; Allen, Steven W.; Angelini, Lorella; Audard, Marc; Awaki, Hisamitsu; Axelsson, Magnus; Bamba, Aya; Bautz, Marshall W.; Blandford, Roger; Brenneman, Laura W.; Brown, Gregory V.; Bulbul, Esra; Cackett, Edward M.; Chernyakova, Maria; Chiao, Meng P.; Coppi, Paolo S.; Costantini, Elisa; de Plaa, Jelle; de Vries, Cor P.; den Herder, Jan-Willem; Done, Chris; Dotani, Tadayasu; Ebisawa, Ken; Eckart, Megan E.; Enoto, Teruaki; Ezoe, Yuichiro; Fabian, Andrew C.; Ferrigno, Carlo; Foster, Adam R.; Fujimoto, Ryuichi; Fukazawa, Yasushi; Furuzawa, Akihiro; Galeazzi, Massimiliano; Gallo, Luigi C.; Gandhi, Poshak; Giustini, Margherita; Goldwurm, Andrea; Gu, Liyi; Guainazzi, Matteo; Haba, Yoshito; Hagino, Kouichi; Hamaguchi, Kenji; Harrus, Ilana M.; Hatsukade, Isamu; Hayashi, Katsuhiro; Hayashi, Takayuki; Hayashida, Kiyoshi; Hiraga, Junko S.; Hornschemeier, Ann; Hoshino, Akio; Hughes, John P.; Ichinohe, Yuto; Iizuka, Ryo; Inoue, Hajime; Inoue, Yoshiyuki; Ishida, Manabu; Ishikawa, Kumi; Ishisaki, Yoshitaka; Iwai, Masachika; Kaastra, Jelle; Kallman, Tim; Kamae, Tsuneyoshi; Kataoka, Jun; Katsuda, Satoru; Kawai, Nobuyuki; Kelley, Richard L.; Kilbourne, Caroline A.; Kitaguchi, Takao; Kitamoto, Shunji; Kitayama, Tetsu; Kohmura, Takayoshi; Kokubun, Motohide; Koyama, Katsuji; Koyama, Shu; Kretschmar, Peter; Krimm, Hans A.; Kubota, Aya; Kunieda, Hideyo; Laurent, Philippe; Lee, Shiu-Hang; Leutenegger, Maurice A.; Limousin, Olivier; Loewenstein, Michael; Long, Knox S.; Lumb, David; Madejski, Greg; Maeda, Yoshitomo; Maier, Daniel; Makishima, Kazuo; Markevitch, Maxim; Matsumoto, Hironori; Matsushita, Kyoko; McCammon, Dan; McNamara, Brian R.; Mehdipour, Missagh; Miller, Eric D.; Miller, Jon M.; Mineshige, Shin; Mitsuda, Kazuhisa; Mitsuishi, Ikuyuki; Miyazawa, Takuya; Mizuno, Tsunefumi; Mori, Hideyuki; Mori, Koji; Mukai, Koji; Murakami, Hiroshi; Mushotzky, Richard F.; Nakagawa, Takao; Nakajima, Hiroshi; Nakamori, Takeshi; Nakashima, Shinya; Nakazawa, Kazuhiro; Nobukawa, Kumiko K.; Nobukawa, Masayoshi; Noda, Hirofumi; Odaka, Hirokazu; Ohashi, Takaya; Ohno, Masanori; Okajima, Takashi; Ota, Naomi; Ozaki, Masanobu; Paerels, Frits; Paltani, Stéphane; Petre, Robert; Pinto, Ciro; Porter, Frederick S.; Pottschmidt, Katja; Reynolds, Christopher S.; Safi-Harb, Samar; Saito, Shinya; Sakai, Kazuhiro; Sasaki, Toru; Sato, Goro; Sato, Kosuke; Sato, Rie; Sato, Toshiki; Sawada, Makoto; Schartel, Norbert; Serlemtsos, Peter J.; Seta, Hiromi; Shidatsu, Megumi; Simionescu, Aurora; Smith, Randall K.; Soong, Yang; Stawarz, Łukasz; Sugawara, Yasuharu; Sugita, Satoshi; Szymkowiak, Andrew; Tajima, Hiroyasu; Takahashi, Hiromitsu; Takahashi, Tadayuki; Takeda, Shin'ichiro; Takei, Yoh; Tamagawa, Toru; Tamura, Takayuki; Tanaka, Takaaki; Tanaka, Yasuo; Tanaka, Yasuyuki T.; Tashiro, Makoto S.; Tawara, Yuzuru; Terada, Yukikatsu; Terashima, Yuichi; Tombesi, Francesco; Tomida, Hiroshi; Tsuboi, Yohko; Tsujimoto, Masahiro; Tsunemi, Hiroshi; Tsuru, Takeshi Go; Uchida, Hiroyuki; Uchiyama, Hideki; Uchiyama, Yasunobu; Ueda, Shutaro; Ueda, Yoshihiro; Uno, Shin'ichiro; Urry, C. Megan; Ursino, Eugenio; Watanabe, Shin; Werner, Norbert; Wilkins, Dan R.; Williams, Brian J.; Yamada, Shinya; Yamaguchi, Hiroya; Yamaoka, Kazutaka; Yamasaki, Noriko Y.; Yamauchi, Makoto; Yamauchi, Shigeo; Yaqoob, Tahir; Yatsu, Yoichi; Yonetoku, Daisuke; Zhuravleva, Irina; Zoghbi, Abderahmen

    2018-03-01

    We present Hitomi observations of N 132 D, a young, X-ray bright, O-rich core-collapse supernova remnant in the Large Magellanic Cloud (LMC). Despite a very short observation of only 3.7 ks, the Soft X-ray Spectrometer (SXS) easily detects the line complexes of highly ionized S K and Fe K with 16-17 counts in each. The Fe feature is measured for the first time at high spectral resolution. Based on the plausible assumption that the Fe K emission is dominated by He-like ions, we find that the material responsible for this Fe emission is highly redshifted at ˜ 800 km s-1 compared to the local LMC interstellar medium (ISM), with a 90% credible interval of 50-1500 km s-1 if a weakly informative prior is placed on possible line broadening. This indicates (1) that the Fe emission arises from the supernova ejecta, and (2) that these ejecta are highly asymmetric, since no blueshifted component is found. The S K velocity is consistent with the local LMC ISM, and is likely from swept-up ISM material. These results are consistent with spatial mapping that shows the He-like Fe concentrated in the interior of the remnant and the S tracing the outer shell. The results also show that even with a very small number of counts, direct velocity measurements from Doppler-shifted lines detected in extended objects like supernova remnants are now possible. Thanks to the very low SXS background of ˜ 1 event per spectral resolution element per 100 ks, such results are obtainable during short pointed or slew observations with similar instruments. This highlights the power of high-spectral-resolution imaging observations, and demonstrates the new window that has been opened with Hitomi and will be greatly widened with future missions such as the X-ray Astronomy Recovery Mission (XARM) and Athena.

  15. Study of the Correlations and the MAXI Hardness Ratio between the Anomalous and Normal Low States of LMC X-3

    Science.gov (United States)

    Torpin, Trevor; Boyd, Patricia T.; Smale, Alan P.

    2015-01-01

    The bright, unusual black-hole X-ray binary LMC X-3 has been monitored virtually continuously by the Japanese MAXI X-ray All-Sky Monitor aboard the International Space Station (Matsuoka, et al., PASJ, 2009) from August 2009 to the present. Comparison with RXTE PCA and ASM light curves during the ~2.33-year period of overlap demonstrate that despite slight differences in energy-band boundaries both the ASM and MAXI faithfully reproduce characteristics of the high-amplitude, nonperiodic long-term variability, on the order of 100-300 days, clearly seen in the more sensitive PCA monitoring. The mechanism for this variability at a timescale many times longer than the 1.7-day orbital period is still unknown. Models to explain the long-term variability invoke mechanisms such as changes in mass transfer rate, and/or a precessing warped accretion disk. Observations of LMC X-3 have not definitely determined whether wind accretion or Roche-love overflow is the driver of the long-term variability. Recent MAXI monitoring of LMC X-3 includes excellent coverage of a rare anomalous low state (ALS) where the X-ray source cannot be distinguished from the background, as well as several normal low states, in which the source count rate passes smoothly through a low, yet detectable value. Pointed Swift XRT and UVOT observations also sample this ALS and one normal low state well. We combine these data sets to study the correlations between the wavelength regimes observed during the ALS versus the normal low. We also examine the behavior of the X-ray hardness ratios using XRT and MAXI monitoring data during the ALS versus the normal low state.

  16. Dwarf spheroidal satellites of M31. I. Variable stars and stellar populations in Andromeda XIX

    Energy Technology Data Exchange (ETDEWEB)

    Cusano, Felice; Clementini, Gisella; Garofalo, Alessia; Federici, Luciana, E-mail: felice.cusano@oabo.inaf.it, E-mail: gisella.clementini@oabo.inaf.it, E-mail: luciana.federici@oabo.inaf.it, E-mail: alessia.garofalo@studio.unibo.it [INAF-Osservatorio Astronomico di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); and others

    2013-12-10

    We present B, V time-series photometry of Andromeda XIX (And XIX), the most extended (half-light radius of 6.'2) of Andromeda's dwarf spheroidal companions, which we observed with the Large Binocular Cameras at the Large Binocular Telescope. We surveyed a 23' × 23' area centered on And XIX and present the deepest color-magnitude diagram (CMD) ever obtained for this galaxy, reaching, at V ∼ 26.3 mag, about one magnitude below the horizontal branch (HB). The CMD shows a prominent and slightly widened red giant branch, along with a predominantly red HB, which extends to the blue to significantly populate the classical instability strip. We have identified 39 pulsating variable stars, of which 31 are of RR Lyrae type and 8 are Anomalous Cepheids (ACs). Twelve of the RR Lyrae variables and three of the ACs are located within And XIX's half light radius. The average period of the fundamental mode RR Lyrae stars ((P {sub ab}) = 0.62 days, σ = 0.03 days) and the period-amplitude diagram qualify And XIX as an Oosterhoff-Intermediate system. From the average luminosity of the RR Lyrae stars ((V(RR)) = 25.34 mag, σ = 0.10 mag), we determine a distance modulus of (m – M){sub 0} = 24.52 ± 0.23 mag in a scale where the distance to the Large Magellanic Cloud (LMC) is 18.5 ± 0.1 mag. The ACs follow a well-defined Period-Wesenheit (PW) relation that appears to be in very good agreement with the PW relationship defined by the ACs in the LMC.

  17. Spectral of electrocardiographic RR intervals to indicate atrial fibrillation

    Science.gov (United States)

    Nuryani, Nuryani; Satrio Nugroho, Anto

    2017-11-01

    Atrial fibrillation is a serious heart diseases, which is associated on the risk of death, and thus an early detection of atrial fibrillation is necessary. We have investigated spectral pattern of electrocardiogram in relation to atrial fibrillation. The utilized feature of electrocardiogram is RR interval. RR interval is the time interval between a two-consecutive R peaks. A series of RR intervals in a time segment is converted to a signal with a frequency domain. The frequency components are investigated to find the components which significantly associate to atrial fibrillation. A segment is defined as atrial fibrillation or normal segments by considering a defined number of atrial fibrillation RR in the segment. Using clinical data of 23 patients with atrial fibrillation, we find that the frequency components could be used to indicate atrial fibrillation.

  18. Genetic divergence of roundup ready (RR) soybean cultivars ...

    African Journals Online (AJOL)

    The aim of this study was to estimate the genetic diversity in 74 RR soybean cultivars from different Brazilian breeding programs. ... chosen SSR markers were effective in assessing the genetic diversity among genotypes, besides proving to be ...

  19. Production of a conjugated fatty acid by Bifidobacterium breve LMC520 from α-linolenic acid: conjugated linolenic acid (CLnA).

    Science.gov (United States)

    Park, Hui Gyu; Cho, Hyung Taek; Song, Myoung-Chong; Kim, Sang Bum; Kwon, Eung Gi; Choi, Nag Jin; Kim, Young Jun

    2012-03-28

    This study was performed to characterize natural CLnA isomer production by Bifidobacterium breve LMC520 of human origin in comparison to conjugated linoleic acid (CLA) production. B. breve LMC520 was found to be highly active in terms of CLnA production, of which the major portion was identified as cis-9,trans-11,cis-15 CLnA isomer by GC-MS and NMR analysis. B. breve LMC520 was incubated for 48 h using MRS medium (containing 0.05% L-cysteine · HCl) under different environmental conditions such as atmosphere, pH, and substrate concentration. The high conversion rate of α-linolenic acid (α-LNA) to CLnA (99%) was retained up to 2 mM α-LNA, and the production was proportionally increased nearly 7-fold with 8 mM by the 6 h of incubation under anaerobic conditions at a wide range of pH values (between 5 and 9). When α-LNA was compared with linoleic acid (LA) as a substrate for isomerization by B. breve LMC520, the conversion of α-LNA was higher than that of LA. These results demonstrated that specific CLnA isomer could be produced through active bacterial conversion at an optimized condition. Because many conjugated octadecatrienoic acids in nature are shown to play many positive roles, the noble isomer found in this study has potential as a functional source.

  20. A spatially resolved study of photoelectric heating and [C II] cooling in the LMC Comparison with dust emission as seen by SAGE

    NARCIS (Netherlands)

    Rubin, D.; Hony, S.; Madden, S. C.; Tielens, A. G. G. M.; Meixner, M.; Indebetouw, R.; Reach, W.; Ginsburg, A.; Kim, S.; Mochizuki, K.; Babler, B.; Block, M.; Bracker, S. B.; Engelbracht, C. W.; For, B. -Q.; Gordon, K.; Hora, J. L.; Leitherer, C.; Meade, M.; Misselt, K.; Sewilo, M.; Vijh, U.; Whitney, B.

    Context. Photoelectric heating is a dominant heating mechanism for many phases of the interstellar medium. We study this mechanism throughout the Large Magellanic Cloud (LMC). Aims. We aim to quantify the importance of the [C II] cooling line and the photoelectric heating process of various

  1. Unusual Black Hole Binary LMC X-3: A Transient High-Mass X-Ray Binary That Is Almost Always On?

    Science.gov (United States)

    Torpin, Trevor J.; Boyd, Patricia T.; Smale, Alan P.; Valencic, Lynne A.

    2017-01-01

    We have analyzed a rich, multimission, multiwavelength data set from the black hole X-ray binary (BHXB) LMC X-3, covering a new anomalous low state (ALS), during which the source flux falls to an unprecedentedly low and barely detectable level, and a more normal low state. Simultaneous X-ray and UV/optical monitoring data from Swift are combined with pointed observations from the Rossi X-ray Timing Explorer (RXTE) and X-ray Multi- Mirror Mission (XMM-Newton) and light curves from the Monitor of All-Sky X-ray Image (MAXI) instrument to compare the source characteristics during the ALS with those seen during the normal low state. An XMM-Newton spectrum obtained during the ALS can be modeled using an absorbed power law with Gamma = 1.41‚+/- 0.65 and a luminosity of 7.97 x 10(exp 33) erg/s (0.6-5 keV). The Swift X-ray and UV light curves indicate an X-ray lag of approx. 8 days as LMC X-3 abruptly exits the ALS, suggesting that changes in the mass accretion rate from the donor drive the X-ray lag. The normal low state displays an asymmetric profile in which the exit occurs more quickly than the entry, with minimum X-ray flux a factor of approx. 4300 brighter than during the ALS. The UV brightness of LMC X-3 in the ALS is also fainter and less variable than during normal low states. The existence of repeated ALSs in LMC X-3, as well as a comparison with other BHXBs, implies that it is very close to the transient/persistent X-ray source dividing line. We conclude that LMC X-3 is a transient source that is almost always "on."

  2. A search for β Cephei variable stars in the Magellanic Clouds: motivation and first results for the LMC

    International Nuclear Information System (INIS)

    Sterken, C.; Jerzykiewicz, M.

    1988-01-01

    Motivation for starting a programme of detecting and investigating β Cephei variables in the Magellanic Clouds is given. Differential photoelectric observations are then reported of six LMC stars which fall in the instability strip defined by the galactic β Cephei variables. Three programme stars are found to exhibit short-term brightness variations. One of them, showing a sinusoidal light-curve with an amplitude (half-range) equal to 0.0070 ± 0.0011 mag and a period equal to about 5 hr, is a promising β Cephei candidate. In the case of the other two variable programme stars, the interpretation of the results is less straightforward. The remaining three programme stars are shown to be constant on a short time-scale, two to within ± 0.010 mag, and one to within ± 0.005 magn. (author)

  3. Stellar Variability at the Main-sequence Turnoff of the Intermediate-age LMC Cluster NGC 1846

    Science.gov (United States)

    Salinas, R.; Pajkos, M. A.; Vivas, A. K.; Strader, J.; Contreras Ramos, R.

    2018-04-01

    Intermediate-age (IA) star clusters in the Large Magellanic Cloud (LMC) present extended main-sequence turn-offs (MSTO) that have been attributed to either multiple stellar populations or an effect of stellar rotation. Recently it has been proposed that these extended main sequences can also be produced by ill-characterized stellar variability. Here we present Gemini-S/Gemini Multi-Object Spectrometer (GMOS) time series observations of the IA cluster NGC 1846. Using differential image analysis, we identified 73 new variable stars, with 55 of those being of the Delta Scuti type, that is, pulsating variables close the MSTO for the cluster age. Considering completeness and background contamination effects, we estimate the number of δ Sct belonging to the cluster between 40 and 60 members, although this number is based on the detection of a single δ Sct within the cluster half-light radius. This amount of variable stars at the MSTO level will not produce significant broadening of the MSTO, albeit higher-resolution imaging will be needed to rule out variable stars as a major contributor to the extended MSTO phenomenon. Though modest, this amount of δ Sct makes NGC 1846 the star cluster with the highest number of these variables ever discovered. Lastly, our results present a cautionary tale about the adequacy of shallow variability surveys in the LMC (like OGLE) to derive properties of its δ Sct population. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the National Research Council (Canada), CONICYT (Chile), Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina), and Ministério da Ciência, Tecnologia e Inovação (Brazil).

  4. Steam in RR Telescopii and Henize 2-38

    Energy Technology Data Exchange (ETDEWEB)

    Allen, D A [Anglo-Australian Observatory, Epping (Australia); Beattie, D H; Lee, T J; Stewart, J M; Williams, P M

    1978-03-01

    Low-resolution scans in the 1.9-2.6..mu..m atmospheric window reveal steam (H/sub 2/O) and CO adsorption bands in the spectra of the symbiotic stars RR Tel and He 2-38. The steam absorption in RR Tel is particularly intense while the CO is weak, implying the presence in the system of a Mira variable seen near minimum light. In He 2-38 the steam band is weaker while the CO is stronger, as expected for a Mira seen near maximum.

  5. The MACHO Project 9 Million Star Color-Magnitude Diagram of the Large Magellanic Cloud

    International Nuclear Information System (INIS)

    Alcock, C.; Allsman, R. A.; Alves, D. R.; Axelrod, T. S.; Basu, A.; Becker, A. C.; Bennett, D. P.; Cook, K. H.; Drake, A. J.; Freeman, K. C.

    2000-01-01

    We present a 9 million star color-magnitude diagram (9M CMD) of the Large Magellanic Cloud (LMC) bar. The 9M CMD reveals a complex superposition of different-age and -metallicity stellar populations, with important stellar evolutionary phases occurring over 3 orders of magnitude in number density. First, we count the nonvariable red and blue supergiants and the associated Cepheid variables and measure the stellar effective temperatures defining the Cepheid instability strip. Lifetime predictions of stellar evolution theory are tested, with implications for the origin of low-luminosity Cepheids. The highly evolved asymptotic giant branch (AGB) stars in the 9M CMD have a bimodal distribution in brightness, which we interpret as discrete old populations ((greater-or-similar sign)1 Gyr). The faint AGB sequence may be metal-poor and very old. Comparing the mean properties of giant branch and horizontal-branch (HB) stars in the 9M CMD with those of clusters, we identify NGC 411 and M3 as templates for the admixture of old stellar populations in the bar. However, there are several indications that the old and metal-poor field population has a red HB morphology: the RR Lyrae variables lie preferentially on the red edge of the instability strip, the AGB bump is very red, and the ratio of AGB bump stars to RR Lyrae variables is quite large. If the HB second parameter is age, the old and metal-poor field population in the bar likely formed after the oldest LMC clusters. Lifetime predictions of stellar evolution theory lead us to associate a significant fraction of the ∼1 million red HB clump giants in the 9M CMD with the same old and metal-poor population producing the RR Lyrae stars and the AGB bump. In this case, compared with the age-dependent luminosity predictions of stellar evolution theory, the red HB clump is too bright relative to the RR Lyrae stars and AGB bump. Last, we show that the surface density profile of RR Lyrae variables is fitted by an exponential

  6. The MACHO Project 9 Million Star Color-Magnitude Diagram of the Large Magellanic Cloud

    Energy Technology Data Exchange (ETDEWEB)

    Alcock, C.; Allsman, R. A.; Alves, D. R.; Axelrod, T. S.; Basu, A.; Becker, A. C.; Bennett, D. P.; Cook, K. H.; Drake, A. J.; Freeman, K. C. (and others)

    2000-05-01

    We present a 9 million star color-magnitude diagram (9M CMD) of the Large Magellanic Cloud (LMC) bar. The 9M CMD reveals a complex superposition of different-age and -metallicity stellar populations, with important stellar evolutionary phases occurring over 3 orders of magnitude in number density. First, we count the nonvariable red and blue supergiants and the associated Cepheid variables and measure the stellar effective temperatures defining the Cepheid instability strip. Lifetime predictions of stellar evolution theory are tested, with implications for the origin of low-luminosity Cepheids. The highly evolved asymptotic giant branch (AGB) stars in the 9M CMD have a bimodal distribution in brightness, which we interpret as discrete old populations ((greater-or-similar sign)1 Gyr). The faint AGB sequence may be metal-poor and very old. Comparing the mean properties of giant branch and horizontal-branch (HB) stars in the 9M CMD with those of clusters, we identify NGC 411 and M3 as templates for the admixture of old stellar populations in the bar. However, there are several indications that the old and metal-poor field population has a red HB morphology: the RR Lyrae variables lie preferentially on the red edge of the instability strip, the AGB bump is very red, and the ratio of AGB bump stars to RR Lyrae variables is quite large. If the HB second parameter is age, the old and metal-poor field population in the bar likely formed after the oldest LMC clusters. Lifetime predictions of stellar evolution theory lead us to associate a significant fraction of the {approx}1 million red HB clump giants in the 9M CMD with the same old and metal-poor population producing the RR Lyrae stars and the AGB bump. In this case, compared with the age-dependent luminosity predictions of stellar evolution theory, the red HB clump is too bright relative to the RR Lyrae stars and AGB bump. Last, we show that the surface density profile of RR Lyrae variables is fitted by an exponential

  7. Menopause, hormone replacement and RR and QT modulation during sleep

    Czech Academy of Sciences Publication Activity Database

    Lanfranchi, P. A.; Gosselin, N.; Kára, T.; Jurák, Pavel; Somers, V. K.; Denesle, R.; Petit, D.; Carrier, J.; Nadeau, R.; Montplaisir, J.

    2005-01-01

    Roč. 6, č. 6 (2005), s. 561-566 ISSN 1389-9457 R&D Projects: GA ČR(CZ) GA102/05/0402 Keywords : Sleep * Menopause * RR interval * QT interval * Gender * Hormones Subject RIV: FS - Medical Facilities ; Equipment Impact factor: 2.711, year: 2005

  8. Mobility and the Modern Intellectual: Translated Images from Early 20th-Century Literary Works in Spanish by Carmen Lyra and Luisa Luisi

    Directory of Open Access Journals (Sweden)

    Laura Kanost

    2018-02-01

    Full Text Available This essay juxtaposes original translations of contrasting images from the novel En una silla de ruedas [In a Wheelchair] by Costa Rican writer Carmen Lyra and Poemas de la inmovilidad [Poems of Immobility] by Uruguayan writer Luisa Luisi to reveal how representations of intellectuals who are paralyzed might complicate discourses of the artist, social hygiene, and eugenics in early 20th-century Spanish America. Lyra portrays her protagonist's paralysis as a tragedy, but his disability is also the source of social mobility that allows the novel to depict marginalized members of Costa Rican society. Luisi contests modernista aesthetics of perfect forms, countering with a multifaceted exploration of inner space enabled by physical stillness. Through their depictions of hospitals, asylums, and sanitariums, both writers bear witness to bodies the modernizing project would prefer to hide, and imagine alternative forms of progress.

  9. Edu Lobo e Carlos Lyra: O Nacional e o Popular na Canção de Protesto (Os Anos 60

    Directory of Open Access Journals (Sweden)

    Arnaldo Daraya Contier

    1998-01-01

    Full Text Available Trata-se de um estudo sobre as possíveis conexões entre a canção de protesto (Edu Lobo, Carlos Lyra e os discursos do CPC durante os anos 60. As criações artísticas são analisadas com vistas a captar os vínculos entre o nacional-popular na canção brasileira e o impressionismo (C. Debussy, o cool-jazz (Miles Davis, Rodgers and Hart, Heitor Villa-Lobos (modernismo, Waldemar Henrique.This is a study if the possible connections between the protest song (Edu Lobo, Carlos Lyra and the CPC discourses in the 1960s. The artistics creations are analysed with a view to pointing out the ties between the national-popular in Brazilian song and the impressionism (C. Debussy, the cool-jazz (Miles Davis, Rodgers and Hart, Heitor Villa-Lobos (modernism, Waldemar Henrique.

  10. Linear relations between leaf mass per area (LMA) and seasonal climate discovered through Linear Manifold Clustering (LMC)

    Science.gov (United States)

    Kiang, N. Y.; Haralick, R. M.; Diky, A.; Kattge, J.; Su, X.

    2016-12-01

    Leaf mass per area (LMA) is a critical variable in plant carbon allocation, correlates with leaf activity traits (photosynthetic activity, respiration), and is a controller of litterfall mass and hence carbon substrate for soil biogeochemistry. Recent advances in understanding the leaf economics spectrum (LES) show that LMA has a strong correlation with leaf life span, a trait that reflects ecological strategy, whereas physiological traits that control leaf activity scale with each other when mass-normalized (Osnas et al., 2013). These functional relations help reduce the number of independent variables in quantifying leaf traits. However, LMA is an independent variable that remains a challenge to specify in dynamic global vegetation models (DGVMs), when vegetation types are classified into a limited number of plant functional types (PFTs) without clear mechanistic drivers for LMA. LMA can range orders of magnitude across plant species, as well as vary within a single plant, both vertically and seasonally. As climate relations in combination with alternative ecological strategies have yet to be well identified for LMA, we have assembled 22,000 records of LMA spanning 0.004 - 33 mg/m2 from the numerous contributors to the TRY database (Kattge et al., 2011), with observations distributed over several climate zones and plant functional categories (growth form, leaf type, phenology). We present linear relations between LMA and climate variables, including seasonal temperature, precipitation, and radiation, as derived through Linear Manifold Clustering (LMC). LMC is a stochastic search technique for identifying linear dependencies between variables in high dimensional space. We identify a set of parsimonious classes of LMA-climate groups based on a metric of minimum description to identify structure in the data set, akin to data compression. The relations in each group are compared to Köppen-Geiger climate classes, with some groups revealing continuous linear relations

  11. Adsorção dos corantes RO16, RR2 e RR141 utilizando lodo residual da indústria têxtil Adsorption of dyes RO16, RR2 and RR141 using residual sludge of textile industry

    Directory of Open Access Journals (Sweden)

    Andressa Regina Vasques

    2011-09-01

    Full Text Available A adsorção é uma das técnicas empregadas com sucesso para remoção efetiva da cor presente em efluentes têxteis. Com o objetivo de avaliar os diferentes parâmetros adsortivos, bem como determinar a eficiência de um adsorvente alternativo desenvolvido a partir de lodo residual têxtil na remoção de corantes, foram determinadas curvas de cinética de adsorção e isotermas. Por meio dos dados cinéticos e de equilíbrio obtidos, verificou-se que a 25ºC a adsorção foi favorável para todos os corantes, sendo esta a melhor condição para os corantes RO16 e RR2 na ausência de sais. Para o corante RR141, a adição de NaCl aumentou a capacidade de adsorção do adsorvente no equilíbrio e a adição de Na2SO4 favoreceu a adsorção para o corante RO16, ao contrário do que se observou para os outros dois corantes. A quantidade máxima de corante adsorvida por unidade de massa de adsorvente (q max nas melhores condições adsortivas para os corantes RO16, RR2 e RR141 foi de 81,30, 53,48 e 78,74 mg.g-1, respectivamente.The adsorption is one of the techniques that have been successfully used for effective removal of the dyes present in textile effluents. With the objective to evaluate the different adsorptive parameters, as well as determining the efficiency of one alternative adsorbent in the removal of dyes, kinetics and equilibrium data of adsorption were determined. By the kinetic data and of equilibrium, it was verified that the adsorption was favorable for all the dyes in 25ºC, being the best condition for the dye RO16 and RR2 in the total absence of salt. For the dye RR141, the addition of NaCl increased the adsorption capacity of adsorbent in the equilibrium and the addition of Na2SO4 favored the adsorption for the dye RO16, in contrast to what was observed for the two other dyes. The maximum quantity of dye adsorbed per unit mass of adsorbent (q max in the best adsorptive conditions for the dyes RO16, RR2 and RR141 was of 81

  12. A DARK ENERGY CAMERA SEARCH FOR MISSING SUPERGIANTS IN THE LMC AFTER THE ADVANCED LIGO GRAVITATIONAL-WAVE EVENT GW150914

    Energy Technology Data Exchange (ETDEWEB)

    Annis, J.; Soares-Santos, M.; Diehl, H. T.; Drlica-Wagner, A.; Finley, D. A.; Flaugher, B.; Frieman, J.; Herner, K. [Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States); Berger, E.; Cowperthwaite, P. S.; Drout, M. R. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Brout, D. [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104 (United States); Chen, H.; Doctor, Z.; Farr, B.; Holz, D.; Kessler, R. [Kavli Institute for Cosmological Physics, University of Chicago, Chicago, IL 60637 (United States); Chornock, R. [Astrophysical Institute, Department of Physics and Astronomy, Ohio University, 251B Clippinger Lab, Athens, OH 45701 (United States); Foley, R. J.; Gruendl, R. A. [Department of Astronomy, University of Illinois, 1002 W. Green Street, Urbana, IL 61801 (United States); Collaboration: DES Collaboration; and others

    2016-06-01

    The collapse of a stellar core is expected to produce gravitational waves (GWs), neutrinos, and in most cases a luminous supernova. Sometimes, however, the optical event could be significantly less luminous than a supernova and a direct collapse to a black hole, where the star just disappears, is possible. The GW event GW150914 was detected by the LIGO Virgo Collaboration via a burst analysis that gave localization contours enclosing the Large Magellanic Cloud (LMC). Shortly thereafter, we used DECam to observe 102 deg{sup 2} of the localization area, including 38 deg{sup 2} on the LMC for a missing supergiant search. We construct a complete catalog of LMC luminous red supergiants, the best candidates to undergo invisible core collapse, and collected catalogs of other candidates: less luminous red supergiants, yellow supergiants, blue supergiants, luminous blue variable stars, and Wolf–Rayet stars. Of the objects in the imaging region, all are recovered in the images. The timescale for stellar disappearance is set by the free-fall time, which is a function of the stellar radius. Our observations at 4 and 13 days after the event result in a search sensitive to objects of up to about 200 solar radii. We conclude that it is unlikely that GW150914 was caused by the core collapse of a relatively compact supergiant in the LMC, consistent with the LIGO Collaboration analyses of the gravitational waveform as best interpreted as a high mass binary black hole merger. We discuss how to generalize this search for future very nearby core-collapse candidates.

  13. "Antes e depois da LMC": experiências e dimensões da leucemia mieloide crônica como uma ruptura biográfica

    Directory of Open Access Journals (Sweden)

    Yeimi Alexandra Alzate López

    2014-10-01

    Full Text Available O artigo analisa as experiências de enfermidade de pacientes com leucemia mieloide crônica (LMC, centrando nas dimensões que apontam a chegada da doença como uma ruptura biográfica. Este estudo qualitativo baseou-se na análise das narrativas de seis pacientes, com idades entre 23 e 62 anos, usuários do Sistema Único de Saúde (SUS e pacientes de um hospital – centro de referência em atenção hematológica na cidade de Salvador, Bahia, Brasil. Nos resultados apresenta-se a experiência de ruptura com base em três categorias (1 os significados da doença e a LMC como ameaça; (2 rupturas físicas, sociais e as experiências estigmatizantes; (3 a percepção de um “antes” e um “depois” da LMC, apontando para as mudanças no self, nas relações sociais e na vida cotidiana. Concluiu-se que os impactos biográficos, sociais e dos sistemas de saúde (considerando o custo das medicações atualizam e ampliam questões como o acesso a tratamentos, assim como o enfrentamento do certo e do incerto, em que o “conhecido” da LMC encontra-se pouco acessível ao estoque de conhecimento da vida cotidiana.

  14. A Dark Energy Camera Search for Missing Supergiants in the LMC After the Advanced LIGO Gravitational-Wave Event GW150914

    Science.gov (United States)

    Annis, J.; Soares-Santos, M.; Berger, E.; Brout, D.; Chen, H.; Chornock, R.; Cowperthwaite, P. S.; Diehl, H. T.; Doctor, Z.; Cenko, S. B.

    2016-01-01

    The collapse of a stellar core is expected to produce gravitational waves (GWs), neutrinos, and in most cases a luminous supernova. Sometimes, however, the optical event could be significantly less luminous than a supernova and a direct collapse to a black hole, where the star just disappears, is possible. The GW event GW150914 was detected by the LIGO Virgo Collaboration via a burst analysis that gave localization contours enclosing the Large Magellanic Cloud (LMC). Shortly thereafter, we used DECam to observe 102 deg(exp.2) of the localization area,including 38 deg(exp. 2) on the LMC for a missing supergiant search. We construct a complete catalog of LMC luminous red supergiants, the best candidates to undergo invisible core collapse, and collected catalogs of other candidates:less luminous red supergiants, yellow supergiants, blue supergiants, luminous blue variable stars, and Wolf-Rayet stars. Of the objects in the imaging region, all are recovered in the images. The timescale for stellar disappearance is set by the free-fall time, which is a function of the stellar radius. Our observations at 4 and 13 days after the event result in a search sensitive to objects of up to about 200 solar radii. We conclude that it is unlikely that GW150914 was caused by the core collapse of a relatively compact supergiant in the LMC, consistent with the LIGO Collaboration analyses of the gravitational waveform as best interpreted as a high mass binary black hole merger. We discuss how to generalize this search for future very nearby core-collapse candidates.

  15. Flow distribution in ET-RR-1 core

    International Nuclear Information System (INIS)

    Khattab, M.; Mina, A.R.

    1989-01-01

    In nuclear reactors the flow may be arranged through individual bundles by orifices to achieve better thermal performance. A model based on constant pressure drop across different core regions is developed to determine the flow distribution in reactor core. The friction and grids in the bundles as well as the orifices diameters have an influence on modifying the flow distribution. The application of the proposed model on ET-RR-1 gives reasonable prediction of flow distribution

  16. Response of Haloalkaliphilic Archaeon Natronococcus Jeotgali RR17 to Hypergravity

    Science.gov (United States)

    Thombre, Rebecca S.; Bhalerao, Aniruddha R.; Shinde, Vinaya D.; Dhar, Sunil Kumar; Shouche, Yogesh S.

    2017-06-01

    The survival of archaeabacteria in extreme inhabitable environments on earth that challenge organismic survival is ubiquitously known. However, the studies related to the effect of hypergravity on the growth and proliferation of archaea are unprecedented. The survival of organisms in hypergravity and rocks in addition to resistance to cosmic radiations, pressure and other extremities is imperative to study the possibilities of microbial travel between planets and endurance in hyperaccelerative forces faced during ejection of rocks from planets. The current investigation highlights the growth of an extremophilic archaeon isolated from a rocky substrate in hypergravity environment. The haloalkaliphilic archaeon, Natronococcus jeotgali RR17 was isolated from an Indian laterite rock, submerged in the Arabian sea lining Coastal Maharashtra, India. The endolithic haloarchaeon was subjected to hypergravity from 56 - 893 X gusing acceleration generated by centrifugal rotation. The cells of N. jeotgali RR17 proliferated and demonstrated good growth in hypergravity (223 X g). This is the first report on isolation of endolithic haloarchaeon N. jeotgali RR17 from an Indian laterite rock and its ability to proliferate in hypergravity. The present study demonstrates the ability of microbial life to survive and proliferate in hypergravity. Thus the inability of organismic growth in hypergravity may no longer be a limitation for astrobiology studies related to habitability of substellar objects, brown dwarfs and other planetary bodies in the universe besides planet earth.

  17. Identification of atrial fibrillation using electrocardiographic RR-interval difference

    Science.gov (United States)

    Eliana, M.; Nuryani, N.

    2017-11-01

    Automated detection of atrial fibrillation (AF) is an interesting topic. It is an account of very dangerous, not only as a trigger of embolic stroke, but it’s also related to some else chronical disease. In this study, we analyse the presence of AF by determining irregularities of RR-interval. We utilize the interval comparison to measure the degree of irregularities of RR-interval in a defined segment. The series of RR-interval is segmented with the length of 10 of them. In this study, we use interval comparison for the method. We were comparing all of the intervals there each other. Then we put the threshold to define the low difference and high difference (δ). A segment is defined as AF or Normal Sinus by the number of high δ, so we put the tolerance (β) of high δ there. We have used this method to test the 23 patients data from MIT-BIH. Using the approach and the clinical data we find accuracy, sensitivity, and specificity of 84.98%, 91.99%, and 77.85% respectively.

  18. Structural changes in the hot Algol OGLE-LMC-DPV-097 and its disc related to its long cycle

    Science.gov (United States)

    Garcés L, J.; Mennickent, R. E.; Djurašević, G.; Poleski, R.; Soszyński, I.

    2018-06-01

    Double Periodic Variables (DPVs) are hot Algols showing a long photometric cycle of uncertain origin. We report the discovery of changes in the orbital light curve of OGLE-LMC-DPV-097 which depend on the phase of its long photometric cycle. During the ascending branch of the long cycle the brightness at the first quadrature is larger than during the second quadrature, during the maximum of the long cycle the brightness is basically the same at both quadratures, during the descending branch the brightness at the second quadrature is larger than during the first quadrature, and during the minimum of the long cycle the secondary minimum disappears. We model the light curve at different phases of the long cycle and find that the data are consistent with changes in the properties of the accretion disc and two disc spots. The disc's size and temperature change with the long-cycle period. We find a smaller and hotter disc at minimum, and larger and cooler disc at maximum. The spot temperatures, locations, and angular sizes also show variability during the long cycle.

  19. AGAPEROS Searches for microlensing in the LMC with the Pixel Method; 2, Selection of possible microlensing events

    CERN Document Server

    Melchior, A.L.; Ansari, R; Aubourg, E.; Baillon, P.; Bareyre, P.; Bauer, F.; Beaulieu, J.-Ph.; Bouquet, A.; Brehin, S.; Cavalier, F.; Char, S.; Couchot, F.; Coutures, C.; Ferlet, R.; Fernandez, J.; Gaucherel, C.; Giraud-Heraud, Y.; Glicenstein, J.-F.; Goldman, B.; Gondolo, P.; Gros, M.; Guibert, J.; Hardin, D.; Kaplan, J.; de Kat, J.; Lachieze-Rey, M.; Laurent, B; Lesquoy, E; Magneville, Ch.; Mansoux, B.; Marquette, J.-B.; Maurice, E.; Milsztajn, A.; Moniez, M.; Moreau, O.; Moscoso, L.; Palanque-Delabrouille, N.; Perdereau. O.; Prevot, L.; Renault, C.; Queinnec, F.; Rich, J.; Spiro, M.; Vidal-Madjar, A.; Vigroux, L.; Zylberajch, S.; Magneville, Ch.

    1998-01-01

    We apply the pixel method of analysis (sometimes called ``pixel lensing'') to a small subset of the EROS-1 microlensing observations of the bar of the Large Magellanic Cloud (LMC). The pixel method is designed to find microlensing events of unresolved source stars and had heretofore been applied only to M31 where essentially all sources are unresolved. With our analysis optimised for the detection of long-duration microlensing events due to 0.01-1 Mo Machos, we detect no microlensing events and compute the corresponding detection efficiencies. We show that the pixel method should detect 10 to 20 times more microlensing events for M>0.05 Mo Machos compared to a classical analysis of the same data which latter monitors only resolved stars. In particular, we show that for a full halo of Machos in the mass range 0.1 -- 0.5 Mo, a pixel analysis of the three-year EROS-1 data set covering 0.39 deg^2 would yield 4 events.

  20. AGAPEROS Searches for microlensing in the LMC with the Pixel Method; 1, Data treatment and pixel light curves production

    CERN Document Server

    Melchior, A.-L.; Ansari, R.; Aubourg, E.; Baillon, P.; Bareyre, P.; Bauer, F.; Beaulieu, J.-Ph.; Bouquet, A.; Brehin, S.; Cavalier, F.; Char, S.; Couchot, F.; Coutures, C.; Ferlet, R.; Fernandez, J.; Gaucherel, C.; Giraud-Heraud, Y.; Glicenstein, J.-F.; Goldman, B.; Gondolo, P.; Gros, M.; Guibert, J.; Gry, C.; Hardin, D.; Kaplan, J.; de Kat, J.; Lachieze-Rey, M.; Laurent, B.; Lesquoy, E.; Magneville, Ch.; Mansoux, B.; Marquette, J.-B.; Maurice, E.; Milsztajn, A.; Moniez, M.; Moreau, O.; Moscoso, L.; Palanque-Delabrouille, N.; Perdereau, O.; Prevot, L.; Renault, C.; Queinnec, F.; Rich, J.; Spiro, M.; Vigroux, L.; Zylberajch, S.; Vidal-Madjar, A.; Magneville, Ch.

    1999-01-01

    The presence and abundance of MAssive Compact Halo Objects (MACHOs) towards the Large Magellanic Cloud (LMC) can be studied with microlensing searches. The 10 events detected by the EROS and MACHO groups suggest that objects with 0.5 Mo could fill 50% of the dark halo. This preferred mass is quite surprising, and increasing the presently small statistics is a crucial issue. Additional microlensing of stars too dim to be resolved in crowded fields should be detectable using the Pixel Method. We present here an application of this method to the EROS 91-92 data (one tenth of the whole existing data set). We emphasize the data treatment required for monitoring pixel fluxes. Geometric and photometric alignments are performed on each image. Seeing correction and error estimates are discussed. 3.6" x 3.6" super-pixel light curves, thus produced, are very stable over the 120 days time-span. Fluctuations at a level of 1.8% of the flux in blue and 1.3% in red are measured on the pixel light curves. This level of stabil...

  1. 77 FR 27085 - R.R. Donnelley, Inc., Bloomsburg, PA; Notice of Negative Determination on Reconsideration

    Science.gov (United States)

    2012-05-08

    ... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-80,485] R.R. Donnelley, Inc... workers of R.R. Donnelley, Inc., Bloomsburg, Pennsylvania (subject firm). The Department's Notice of... eligibility to apply for worker adjustment assistance for workers and former workers of R.R. Donnelley, Inc...

  2. A NEW CENSUS OF THE VARIABLE STAR POPULATION IN THE GLOBULAR CLUSTER NGC 2419

    International Nuclear Information System (INIS)

    Di Criscienzo, M.; Greco, C.; Ripepi, V.; Dall' Ora, M.; Marconi, M.; Musella, I.; Clementini, G.; Federici, L.; Di Fabrizio, L.

    2011-01-01

    We present B, V, and I CCD light curves for 101 variable stars belonging to the globular cluster NGC 2419, 60 of which are new discoveries, based on data sets obtained at the Telescopio Nazionale Galileo, the Subaru telescope, and the Hubble Space Telescope. The sample includes 75 RR Lyrae stars (38 RRab, 36 RRc, and one RRd), one Population II Cepheid, 12 SX Phoenicis variables, two δ Scuti stars, three binary systems, five long-period variables, and three variables of uncertain classification. The pulsation properties of the RR Lyrae variables are close to those of Oosterhoff type II clusters, consistent with the low metal abundance and the cluster horizontal branch morphology, disfavoring (but not totally ruling out) an extragalactic hypothesis for the origin of NGC 2419. The observed properties of RR Lyrae and SX Phoenicis stars are used to estimate the cluster reddening and distance, using a number of different methods. Our final value is μ 0 (NGC 2419) = 19.71 ± 0.08 mag (D = 87.5 ± 3.3 kpc), with E(B - V) = 0.08 ± 0.01 mag, [Fe/H] = -2.1 dex on the Zinn and West metallicity scale, and a value of M V that sets μ 0 (LMC) = 18.52 mag. This value is in good agreement with the most recent literature estimates of the distance to NGC 2419.

  3. Disk Disruptions and X-ray Intensity Excursions in Cyg X-2, LMC X-3 and Cyg X-3

    Science.gov (United States)

    Boyd, P. T.; Smale, A. P.

    2001-05-01

    The RXTE All Sky Monitor soft X-ray light curves of many X-ray binaries show long-term intensity variations (a.k.a "superorbital periodicities") that have been ascribed to precession of a warped, tilted accretion disk around the X-ray source. We have found that the excursion times between X-ray minima in Cyg X-2 can be characterized as a series of integer multiples of the 9.8 binary orbital period, (as opposed to the previously reported stable 77.7 day single periodicity, or a single modulation whose period changes slowly with time). While the data set is too short for a proper statistical analysis, it is clear that the length of any given intensity excursion cannot be used to predict the next (integer) excursion length in the series. In the black hole candidate system LMC X-3, the excursion times are shown to be related to each other by rational fractions. We find that the long term light curve of the unusual galactic X-ray jet source Cyg X-3 can also be described as a series of intensity excursions related to each other by integer multiples of a fundamental underlying clock. In the latter cases, the clock is apparently not related to the known binary periods. A unified physical model, involving both an inclined accretion disk and a fixed-probability disk disruption mechanism is presented, and compared with three-body scattering results. Each time the disk passes through the orbital plane it experiences a fixed probability P that it will disrupt. This model has testable predictions---the distribution of integers should resemble that of an atomic process with a characteristic half life. Further analysis can support or refute the model, and shed light on what system parameters effectively set the value of P.

  4. LMC X-1: A New Spectral Analysis of the O-star in the Binary and Surrounding Nebula

    Science.gov (United States)

    Hyde, E. A.; Russell, D. M.; Ritter, A.; Filipović, M. D.; Kaper, L.; Grieve, K.; O'Brien, A. N.

    2017-09-01

    We provide new observations of the LMC X-1 O star and its extended nebula structure using spectroscopic data from VLT/UVES as well as Hα imaging from the Wide Field Imager on the Max Planck Gesellschaft/European Southern Observatory 2.2 m telescope and ATCA imaging of the 2.1 GHz radio continuum. This nebula is one of the few known to be energized by an X-ray binary. We use a new spectrum extraction technique that is superior to other methods used to obtain both radial velocities and fluxes. This provides an updated spatial velocity of ≃ 21.0 +/- 4.8 km s-1 for the O star. The slit encompasses both the photo-ionized and shock-ionized regions of the nebula. The imaging shows a clear arc-like structure reminiscent of a wind bow shock in between the ionization cone and shock-ionized nebula. The observed structure can be fit well by the parabolic shape of a wind bow shock. If an interpretation of a wind bow shock system is valid, we investigate the N159-O1 star cluster as a potential parent of the system, suggesting a progenitor mass of ˜60 M ⊙ for the black hole. We further note that the radio emission could be non-thermal emission from the wind bow shock, or synchrotron emission associated with the jet-inflated nebula. For both wind- and jet-powered origins, this would represent one of the first radio detections of such a structure.

  5. Lignification of the plant and seed quality of RR soybeans sprayed with herbicide glyphosate

    Directory of Open Access Journals (Sweden)

    Cristiane Fortes Gris

    2013-04-01

    Full Text Available Differences in levels of lignin in the plant between conventional and transgenic cultivars RR has been reported by several authors, however, there are few studies evaluating the influence of spraying of glyphosate on the lignin in the plant and RR soybean seeds. The aim of this study was to evaluate the physiological quality of RR transgenic soybean seeds and the lignin contents of plants sprayed with the herbicide glyphosate. The assays were conducted both in greenhouse and field in the municipality of Lavras, MG, in the agricultural year 2007/08. The experiment was arranged in a splitplot design with four replicates, considering the treatments hand weeding and herbicide glyphosate as plots, and five RR soybean cultivars (BRS 245 RR, BRS 247 RR, Valiosa RR, Silvânia RR and Baliza RR as splitplots. In the greenhouse, the cultivars tested were BRS 245 RR and Valiosa RR in a randomized block design with four replicates. The sprayings were carried out at stages V3, V7 and early R5 (3L/ha. The 1000 seed weight, mechanical injury, germination and germination velocity index, emergence velocity index, accelerated aging, electrical conductivity and water soaking seed test, lignin content in the seed coat, in the stem and legumes were determined. The spraying of glyphosate herbicide, in greenhouse and field, did not alter the physiological quality of seeds and the lignin contents in the plant.

  6. Detection of soft X-rays from α Lyrae and eta Bootis with an imaging X-ray telescope

    International Nuclear Information System (INIS)

    Topka, K.; Fabricant, D.; Harnden, F.R. Jr.; Gorenstein, P.; Rosner, R.

    1979-01-01

    Two nearby stars have been detected in the soft X-ray band with an imaging X-ray telescope flown aboard two sounding rockets. The exposure times were 4.8 and 4.5 s for the images of the AO V star α Lyrae (Vega) and the GO IV star eta Bootis, respectively. Laboratory measurements rule out the possibility that the observed signals were due to UV contamination. These X-ray observations imply luminosities of L/sub X/(0.2--0.8 keV) approx. =3 x 10 28 ergs s -1 for Vega and L/sub X/(0.15--1.5 keV) approx. =1 x 10 29 ergs s -1 for eta Boo. A coronal interpretation of the X-rays from Vega is in serious conflict with simple convective models for early-type main-sequence stars. Magnetic field activity may be responsible for heating the corona, as has been suggested for the Sun. In the case of eta Boo, a coronal interpretation is also favored; however, if the unseen companion of eta Boo is degenerate, the X-ray emission may instead originate in a stellar wind accreting upon a white dwarf or neutron star

  7. The Globular Cluster NGC 6402 (M14). II. Variable Stars

    DEFF Research Database (Denmark)

    Contreras Peña, C.; Catelan, M.; Grundahl, F.

    2018-01-01

    approaches for the calibration of the absolute magnitudes of RR Lyrae stars. The possible presence of second-overtone RR Lyrae in M14 is critically addressed, with our results arguing against this possibility. By considering all of the RR Lyrae stars as members of the cluster, we derive =0.589 {{d...

  8. Turbulent flow heat transfer in ET-RR-1

    International Nuclear Information System (INIS)

    Khattab, M.; Mina, A.R.

    1990-01-01

    In nuclear reactors the effect of heat transfer coefficient, which depends on the constant C. Is primordial in calculating the clad surface temperatures. To determine the constant C of ET-RR-1 fuel bundles based on in-pile measurements different well known and recommended values of C are verified. A computer program is written to calculate steady thermal core characteristics at different operating conditions. The total flow rate is distributed considering same pressure drop across the core irrespective of bundle location. The total reactor power is readily distributed as Bessel function. The flow and power per bundle are equally distributed among the fuel rods irrespective of their positions inside the bundle. It is found that the constant C equals 0.047 gives acceptable compatibility between measurements and calculations. The maximum clad surface temperature is shifted from the core center

  9. [Heart rate variability study based on a novel RdR RR Intervals Scatter Plot].

    Science.gov (United States)

    Lu, Hongwei; Lu, Xiuyun; Wang, Chunfang; Hua, Youyuan; Tian, Jiajia; Liu, Shihai

    2014-08-01

    On the basis of Poincare scatter plot and first order difference scatter plot, a novel heart rate variability (HRV) analysis method based on scatter plots of RR intervals and first order difference of RR intervals (namely, RdR) was proposed. The abscissa of the RdR scatter plot, the x-axis, is RR intervals and the ordinate, y-axis, is the difference between successive RR intervals. The RdR scatter plot includes the information of RR intervals and the difference between successive RR intervals, which captures more HRV information. By RdR scatter plot analysis of some records of MIT-BIH arrhythmias database, we found that the scatter plot of uncoupled premature ventricular contraction (PVC), coupled ventricular bigeminy and ventricular trigeminy PVC had specific graphic characteristics. The RdR scatter plot method has higher detecting performance than the Poincare scatter plot method, and simpler and more intuitive than the first order difference method.

  10. The MACHO Project LMC Variable Star Inventory. VIII. The Recent Star Formation History of the Large Magellanic Cloud from the Cepheid Period Distribution

    International Nuclear Information System (INIS)

    Alcock, C.; Allsman, R.A.; Alves, D.R.; Axelrod, T.S.; Becker, A.C.; Bennett, D.P.; Bersier, D.F.; Cook, K.H.; Freeman, K.C.; Griest, K.; Guern, J.A.; Lehner, M.; Marshall, S.L.; Minniti, D.; Peterson, B.A.; Pratt, M.R.; Quinn, P.J.; Rodgers, A.W.; Stubbs, C.W.

    1999-01-01

    We present an analysis of the period distribution of about 1800 Cepheids in the LMC, based on data obtained by the MACHO microlensing experiment and on a previous catalog by C. H. Payne Gaposchkin. Using stellar evolution and pulsation models, we construct theoretical period-frequency distributions that are compared with the observations. These models reveal that a significant burst of star formation has occurred recently in the LMC (∼1.15x10 8 yr). We also show that during the last ∼10 8 yr, the main center of star formation has been propagating from southeast to northwest along the bar. We find that the evolutionary masses of Cepheids are still smaller than pulsation masses by ∼7% and that the red edge of the Cepheid instability strip could be slightly bluer than indicated by theory. There are approximately 600 Cepheids with periods below ∼2.5 days that cannot be explained by evolution theory. We suggest that they are anomalous Cepheids and that a number of these stars are double-mode Cepheids. copyright copyright 1999. The American Astronomical Society

  11. The diffuse source at the center of LMC SNR 0509–67.5 is a background galaxy at z = 0.031

    International Nuclear Information System (INIS)

    Pagnotta, Ashley; Walker, Emma S.; Schaefer, Bradley E.

    2014-01-01

    Type Ia supernovae (SNe Ia) are well-known for their use in the measurement of cosmological distances, but our continuing lack of concrete knowledge about their progenitor stars is both a matter of debate and a source of systematic error. In our attempts to answer this question, we presented unambiguous evidence that LMC SNR 0509–67.5, the remnant of an SN Ia that exploded in the Large Magellanic Cloud 400 ± 50 yr ago, did not have any point sources (stars) near the site of the original supernova explosion, from which we concluded that this particular supernova must have had a progenitor system consisting of two white dwarfs. There is, however, evidence of nebulosity near the center of the remnant, which could have been left over detritus from the less massive WD, or could have been a background galaxy unrelated to the supernova explosion. We obtained long-slit spectra of the central nebulous region using GMOS on Gemini South to determine which of these two possibilities is correct. The spectra show Hα emission at a redshift of z = 0.031, which implies that the nebulosity in the center of LMC SNR 0509–67.5 is a background galaxy, unrelated to the supernova.

  12. Lignification of the plant and seed quality of RR soybeans sprayed with herbicide glyphosate

    OpenAIRE

    Gris,Cristiane Fortes; Pinho,Edila Vilela de Resende Von; Carvalho,Maria Laene de Moreira; Diniz,Rafael Parreira; Andrade,Thaís de

    2013-01-01

    Differences in levels of lignin in the plant between conventional and transgenic cultivars RR has been reported by several authors, however, there are few studies evaluating the influence of spraying of glyphosate on the lignin in the plant and RR soybean seeds. The aim of this study was to evaluate the physiological quality of RR transgenic soybean seeds and the lignin contents of plants sprayed with the herbicide glyphosate. The assays were conducted both in greenhouse and field in the muni...

  13. Ventricular Cycle Length Characteristics Estimative of Prolonged RR Interval during Atrial Fibrillation

    Science.gov (United States)

    CIACCIO, EDWARD J.; BIVIANO, ANGELO B.; GAMBHIR, ALOK; EINSTEIN, ANDREW J.; GARAN, HASAN

    2014-01-01

    Background When atrial fibrillation (AF) is incessant, imaging during a prolonged ventricular RR interval may improve image quality. It was hypothesized that long RR intervals could be predicted from preceding RR values. Methods From the PhysioNet database, electrocardiogram RR intervals were obtained from 74 persistent AF patients. An RR interval lengthened by at least 250 ms beyond the immediately preceding RR interval (termed T0 and T1, respectively) was considered prolonged. A two-parameter scatterplot was used to predict the occurrence of a prolonged interval T0. The scatterplot parameters were: (1) RR variability (RRv) estimated as the average second derivative from 10 previous pairs of RR differences, T13–T2, and (2) Tm–T1, the difference between Tm, the mean from T13 to T2, and T1. For each patient, scatterplots were constructed using preliminary data from the first hour. The ranges of parameters 1 and 2 were adjusted to maximize the proportion of prolonged RR intervals within range. These constraints were used for prediction of prolonged RR in test data collected during the second hour. Results The mean prolonged event was 1.0 seconds in duration. Actual prolonged events were identified with a mean positive predictive value (PPV) of 80% in the test set. PPV was >80% in 36 of 74 patients. An average of 10.8 prolonged RR intervals per 60 minutes was correctly identified. Conclusions A method was developed to predict prolonged RR intervals using two parameters and prior statistical sampling for each patient. This or similar methodology may help improve cardiac imaging in many longstanding persistent AF patients. PMID:23998759

  14. RR Tel: Getting Under the Flux Limit: An Observation with FUSE

    Science.gov (United States)

    Sonnenborn, George (Technical Monitor); Kenyon, Scott J.

    2004-01-01

    The goal of this program is to acquire a FUSE spectrum of the symbiotic binary RR Tel. With these data, we plan to derive improved constraints on the hot component, the nebula, and perhaps the red giant wind. Based on results from AG Dra, we should also be able to use some line detections to improve atomic parameters for high ionization emission lines. This results would benefit the general FUSE community. As of this writing, the FUSE observation of RR Tel has not been made. Because RR Tel is a very bright UV source, the FUSE team is assessing the likelihood that RR Tel will have an adverse affect on the instrument.

  15. Thermo-Mechanical Fatigue Crack Growth of RR1000.

    Science.gov (United States)

    Pretty, Christopher John; Whitaker, Mark Thomas; Williams, Steve John

    2017-01-04

    Non-isothermal conditions during flight cycles have long led to the requirement for thermo-mechanical fatigue (TMF) evaluation of aerospace materials. However, the increased temperatures within the gas turbine engine have meant that the requirements for TMF testing now extend to disc alloys along with blade materials. As such, fatigue crack growth rates are required to be evaluated under non-isothermal conditions along with the development of a detailed understanding of related failure mechanisms. In the current work, a TMF crack growth testing method has been developed utilising induction heating and direct current potential drop techniques for polycrystalline nickel-based superalloys, such as RR1000. Results have shown that in-phase (IP) testing produces accelerated crack growth rates compared with out-of-phase (OOP) due to increased temperature at peak stress and therefore increased time dependent crack growth. The ordering of the crack growth rates is supported by detailed fractographic analysis which shows intergranular crack growth in IP test specimens, and transgranular crack growth in 90° OOP and 180° OOP tests. Isothermal tests have also been carried out for comparison of crack growth rates at the point of peak stress in the TMF cycles.

  16. Thermo-Mechanical Fatigue Crack Growth of RR1000

    Directory of Open Access Journals (Sweden)

    Christopher John Pretty

    2017-01-01

    Full Text Available Non-isothermal conditions during flight cycles have long led to the requirement for thermo-mechanical fatigue (TMF evaluation of aerospace materials. However, the increased temperatures within the gas turbine engine have meant that the requirements for TMF testing now extend to disc alloys along with blade materials. As such, fatigue crack growth rates are required to be evaluated under non-isothermal conditions along with the development of a detailed understanding of related failure mechanisms. In the current work, a TMF crack growth testing method has been developed utilising induction heating and direct current potential drop techniques for polycrystalline nickel-based superalloys, such as RR1000. Results have shown that in-phase (IP testing produces accelerated crack growth rates compared with out-of-phase (OOP due to increased temperature at peak stress and therefore increased time dependent crack growth. The ordering of the crack growth rates is supported by detailed fractographic analysis which shows intergranular crack growth in IP test specimens, and transgranular crack growth in 90° OOP and 180° OOP tests. Isothermal tests have also been carried out for comparison of crack growth rates at the point of peak stress in the TMF cycles.

  17. RR Tel: Determination of Dust Properties During Minimum Obscuration

    Directory of Open Access Journals (Sweden)

    Jurkić T.

    2012-06-01

    Full Text Available the ISO infrared spectra and the SAAO long-term JHKL photometry of RR Tel in the epochs during minimum obscuration are studied in order to construct a circumstellar dust model. the spectral energy distribution in the near- and the mid-IR spectral range (1–15 μm was obtained for an epoch without the pronounced dust obscuration. the DUSTY code was used to solve the radiative transfer through the dust and to determine the circumstellar dust properties of the inner dust regions around the Mira component. Dust temperature, maximum grain size, dust density distribution, mass-loss rate, terminal wind velocity and optical depth are determined. the spectral energy distribution and the long-term JHKL photometry during an epoch of minimum obscuration show almost unattenuated stellar source and strong dust emission which cannot be explained by a single dust shell model. We propose a two-component model consisting of an optically thin circmustellar dust shell and optically thick dust outside the line of sight in some kind of a flattened geometry, which is responsible for most of the observed dust thermal emission.

  18. Computer control of ET-RR-1 hot cell manipulators

    International Nuclear Information System (INIS)

    Effat, A.M.; Rahman, F.A.

    1990-01-01

    The hot cell designed for remote handling of radioactive materials are, in effect, integral systems of safety devices for attaining adequate radiological protection for the operating personnel. Their operation involve potential hazards that are sometimes of great magnitude. The effect of an incident or accident could thus be fatal. some of these incident are due to the collision of the manipulator slave side with the radioactive objectives. Therefore in order to minimize the probability of such type of incidents, the movement of the manipulators is suggested (in the present investigation) to be kept under computer control. A model have been developed to control the movement of the hot cell manipulators in the slave side for Egypt first research reactor ET-RR-1, specially in the hidden sectors. The model is based on the use of a microprocessor and some accessories fixed to the manipulators slave side in a special manner such that it prevents the manipulator from colliding with radioactive objects. This is achieved by a signal transmitted to a specially designed brake which controls the movement of the upper arm of the manipulator master side. The hardware design of the model as well as the software are presented in details

  19. AIREKMOD-RR, Reactivity Transients in Nuclear Research Reactors

    International Nuclear Information System (INIS)

    Baggoura, B.; Mazrou, H.

    2001-01-01

    1 - Description of program or function: AIREMOD-RR is a point kinetics code which can simulate fast transients in nuclear research reactor cores. It can also be used for theoretical reactor dynamics studies. It is used for research reactor kinetic analysis and provides a point neutron kinetic capability. The thermal hydraulic behavior is governed by a one-dimensional heat balance equation. The calculations are restricted to a single equivalent unit cell which consists of fuel, clad and coolant. 2 - Method of solution: For transient reactor kinetic calculations a modified Runge Kutta numerical method is used. The external reactivity insertion, specified as a function of time, is converted in dollar ($) unit. The neutron density, energy release and feedback variables are given at each time step. The two types of reactivity feedback considered are: Doppler effect and moderator effect. A new expression for the reactivity dependence on the feedback variables has been introduced in the present version of the code. The feedback reactivities are fitted in power series expression. 3 - Restrictions on the complexity of the problem: The number of delayed neutron groups and the total number of equations are limited only by computer storage capabilities. - Coolant is always in liquid phase. - Void reactivity feedback is not considered

  20. A NOVEL APPROACH TO ARRHYTHMIA CLASSIFICATION USING RR INTERVAL AND TEAGER ENERGY

    Directory of Open Access Journals (Sweden)

    CHANDRAKAR KAMATH

    2012-12-01

    Full Text Available It is hypothesized that a key characteristic of electrocardiogram (ECG signal is its nonlinear dynamic behaviour and that the nonlinear component changes more significantly between normal and arrhythmia conditions than the linear component. The usual statistical descriptors used in RR (R to R interval analysis do not capture the nonlinear disposition of RR interval variability. In this paper we explore a novel approach to extract the features from nonlinear component of the RR interval signal using Teager energy operator (TEO. The key feature of Teager energy is that it models the energy of the source that generated the signal rather than the energy of the signal itself. Hence any deviations in regular rhythmic activity of the heart get reflected in the Teager energy function. The classification evaluated on MIT-BIH database, with RR interval and mean of Teager energy computed over RR interval as features, exhibits an average accuracy that exceeds 99.79%.

  1. IDAS-RR: an incident data base system for research reactors

    International Nuclear Information System (INIS)

    Matsumoto, Kiyoshi; Kohsaka, Atsuo; Kaminaga, Masanori; Murayama, Youji; Ohnishi, Nobuaki; Maniwa, Masaki.

    1990-03-01

    An Incident Data Base System for Research Reactors, IDAS-RR, has been developed. IDAS-RR has information about abnormal incidents (failures, transients, accidents, etc.) of research reactors in the world. Data reference, input, editing and other functions of IDAS-RR are menu driven. The routine processing and data base management functions are performed by the system software and hardware. PC-9801 equipment was selected as the hardware because of its portability and popularity. IDAS-RR provides effective reference information for the following activities. 1) Analysis of abnormal incident of research reactors, 2) Detail analysis of research reactor behavior in the abnormal incident for building the knowledge base of the reactor emergency diagnostic system for research reactor, 3) Planning counter-measure for emergency situation in the research reactor. This report is a user's manual of IDAS-RR. (author)

  2. The OGLE view of microlensing towards the Magellanic Clouds - I. A trickle of events in the OGLE-II LMC data

    Science.gov (United States)

    Wyrzykowski, Ł.; Kozłowski, S.; Skowron, J.; Belokurov, V.; Smith, M. C.; Udalski, A.; Szymański, M. K.; Kubiak, M.; Pietrzyński, G.; Soszyński, I.; Szewczyk, O.; Żebruń, K.

    2009-08-01

    We present the results from the Optical Gravitational Lensing Experiment II (OGLE-II) survey (1996-2000) towards the Large Magellanic Cloud (LMC), which has the aim of detecting the microlensing phenomena caused by dark matter compact objects in the Galactic halo [massive compact halo objects (MACHOs)]. We use high-resolution Hubble Space Telescope images of the OGLE fields and derive the correction for the number of monitored stars in each field. This also yields blending distributions which we use in `catalogue-level' Monte Carlo simulations of the microlensing events in order to calculate the detection efficiency of the events. We detect two candidates for microlensing events in the All Stars Sample, which translates into an optical depth of 0.43 +/- 0.33 × 10-7. If both events were due to MACHO, the fraction of mass of compact dark matter objects in the Galactic halo would be 8 +/- 6 per cent. This optical depth, however, along with the characteristics of the events seems to be consistent with the self-lensing scenario, i.e. self-lensing alone is sufficient to explain the observed microlensing signal. Our results indicate the non-detection of MACHOs lensing towards the LMC with an upper limit on their abundance in the Galactic halo of 19 per cent for M = 0.4Msolar and 10 per cent for masses between 0.01 and 0.2Msolar. Based on observations obtained with the 1.3-m Warsaw Telescope at the Las Campanas Observatory of the Carnegie Institution of Washington. E-mail: wyrzykow@ast.cam.ac.uk ‡ Name pronunciation: Woocash Vizhikovsky.

  3. The coefficient of rolling resistance (CoRR) of some pharmaceutical tablets.

    Science.gov (United States)

    Ketterhagen, William R; Bharadwaj, Rahul; Hancock, Bruno C

    2010-06-15

    Experiments have been conducted to measure the coefficient of rolling resistance (CoRR) of some pharmaceutical tablets and several common materials, such as glass beads and steel ball bearings. CoRR values are required as inputs for discrete element method (DEM) models which can be used to model particulate flows and solid dosage form manufacturing processes. Until now there have been no CoRR data reported for pharmaceutical materials, and thus these new data will help to facilitate more accurate modeling of pharmaceutical systems. Copyright 2010 Elsevier B.V. All rights reserved.

  4. Rodent Research-1 (RR1) NASA Validation Flight: Mouse liver transcriptomic proteomic and epigenomic data

    Data.gov (United States)

    National Aeronautics and Space Administration — RR-1 is a validation flight to evaluate the hardware operational and science capabilities of the Rodent Research Project on the ISS. RNA DNA and protein were...

  5. Rodent Research-1 (RR1) NASA Validation Flight: Mouse soleus muscle transcriptomic and epigenomic data

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA s Rodent Research (RR) project is playing a critical role in advancing biomedical research on the physiological effects of space environments. Due to the...

  6. Rodent Research-1 (RR1) NASA Validation Flight: Mouse kidney transcriptomic proteomic and epigenomic data

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA s Rodent Research (RR) project is playing a critical role in advancing biomedical research on the physiological effects of space environments. Due to the...

  7. Rodent Research-1 (RR1) NASA Validation Flight: Mouse quadriceps muscle transcriptomic proteomic and epigenomic data

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA s Rodent Research (RR) project is playing a critical role in advancing biomedical research on the physiological effects of space environments. Due to the...

  8. Rodent Research-1 (RR1) NASA Validation Flight: Mouse gastrocnemius muscle transcriptomic proteomic and epigenomic data

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA s Rodent Research (RR) project is playing a critical role in advancing biomedical research on the physiological effects of space environments. Due to the...

  9. Rodent Research-1 (RR1) NASA Validation Flight: Mouse eye transcriptomic and epigenomic data

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA s Rodent Research (RR) project is playing a critical role in advancing biomedical research on the physiological effects of space environments. Due to the...

  10. Rodent Research-1 (RR1) NASA Validation Flight: Mouse adrenal gland transcriptomic proteomic and epigenomic data

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA s Rodent Research (RR) project is playing a critical role in advancing biomedical research on the physiological effects of space environments. Due to the...

  11. Mechanism of blood pressure and R-R variability: insights from ganglion blockade in humans

    Science.gov (United States)

    Zhang, Rong; Iwasaki, Kenichi; Zuckerman, Julie H.; Behbehani, Khosrow; Crandall, Craig G.; Levine, Benjamin D.; Blomqvist, C. G. (Principal Investigator)

    2002-01-01

    Spontaneous blood pressure (BP) and R-R variability are used frequently as 'windows' into cardiovascular control mechanisms. However, the origin of these rhythmic fluctuations is not completely understood. In this study, with ganglion blockade, we evaluated the role of autonomic neural activity versus other 'non-neural' factors in the origin of BP and R-R variability in humans. Beat-to-beat BP, R-R interval and respiratory excursions were recorded in ten healthy subjects (aged 30 +/- 6 years) before and after ganglion blockade with trimethaphan. The spectral power of these variables was calculated in the very low (0.0078-0.05 Hz), low (0.05-0.15 Hz) and high (0.15-0.35 Hz) frequency ranges. The relationship between systolic BP and R-R variability was examined by cross-spectral analysis. After blockade, R-R variability was virtually abolished at all frequencies; however, respiration and high frequency BP variability remained unchanged. Very low and low frequency BP variability was reduced substantially by 84 and 69 %, respectively, but still persisted. Transfer function gain between systolic BP and R-R interval variability decreased by 92 and 88 % at low and high frequencies, respectively, while the phase changed from negative to positive values at the high frequencies. These data suggest that under supine resting conditions with spontaneous breathing: (1) R-R variability at all measured frequencies is predominantly controlled by autonomic neural activity; (2) BP variability at high frequencies (> 0.15 Hz) is mediated largely, if not exclusively, by mechanical effects of respiration on intrathoracic pressure and/or cardiac filling; (3) BP variability at very low and low frequencies (rhythmicity; and (4) the dynamic relationship between BP and R-R variability as quantified by transfer function analysis is determined predominantly by autonomic neural activity rather than other, non-neural factors.

  12. DNA aptamer selection and aptamer-based fluorometric displacement assay for the hepatotoxin microcystin-RR

    International Nuclear Information System (INIS)

    Wu, Shijia; Li, Qi; Duan, Nuo; Wang, Zhouping; Ma, Haile

    2016-01-01

    Microcystin-RR (MC-RR) is a highly acute hepatotoxin produced by cyanobacteria. It is harmful to both humans and the environment. A novel aptamer was identified by the systemic evolution of ligands by exponential enrichment (SELEX) method as a recognition element for determination of MC-RR in aquatic products. The graphene oxide (GO) SELEX strategy was adopted to generate aptamers with high affinity and specificity. Of the 50 aptamer candidates tested, sequence RR-33 was found to display high affinity and selectivity, with a dissociation constant of 45.7 ± 6.8 nM. Aptamer RR-33 therefore was used as the recognition element in a fluorometric assay that proceeds as follows: (1) Biotinylated aptamer RR-33 is immobilized on the streptavidinylated wells of a microtiterplate, and carboxyfluorescein (FAM) labelled complementary DNA is then allowed to hybridize. (2) After removal of excess (unbound) cDNA, sample containing MC-RR is added and incubated at 37 °C for 2 h. (3) Displaced free cDNA is washed away and fluorescence intensity measured at excitation/emission wavelengths of 490/515 nm. The calibration plot is linear in the 0.20 to 2.5 ng·mL −1 concentration range, and the limit of detection is 80 pg·mL −1 . The results indicate that the GO-SELEX technology is appropriate for the screening of aptamers against small-molecule toxins. The detection scheme was applied to the determination of MC-RR in (spiked) water, mussel and fish and gave recoveries between 91 and 98 %. The method compares favorably to a known ELISA. Conceivably, this kind of assay is applicable to other toxins for which appropriate aptamers are available. (author)

  13. THE ARAUCARIA PROJECT: A STUDY OF THE CLASSICAL CEPHEID IN THE ECLIPSING BINARY SYSTEM OGLE LMC562.05.9009 IN THE LARGE MAGELLANIC CLOUD

    Energy Technology Data Exchange (ETDEWEB)

    Gieren, Wolfgang; Pilecki, Bogumił; Pietrzyński, Grzegorz; Graczyk, Dariusz; Górski, Marek; Taormina, Mónica; Gallenne, Alexandre, E-mail: wgieren@astro-udec.cl, E-mail: pilecki@astrouw.edu.pl, E-mail: pietrzyn@astrouw.edu.pl [Universidad de Concepción, Departamento de Astronomía, Casilla 160-C, Concepción (Chile); and others

    2015-12-10

    We present a detailed study of the classical Cepheid in the double-lined, highly eccentric eclipsing binary system OGLE-LMC562.05.9009. The Cepheid is a fundamental mode pulsator with a period of 2.988 days. The orbital period of the system is 1550 days. Using spectroscopic data from three 4–8-m telescopes and photometry spanning 22 years, we were able to derive the dynamical masses and radii of both stars with exquisite accuracy. Both stars in the system are very similar in mass, radius, and color, but the companion is a stable, non-pulsating star. The Cepheid is slightly more massive and bigger (M{sub 1} = 3.70 ± 0.03 M{sub ⊙}, R{sub 1} = 28.6 ± 0.2 R{sub ⊙}) than its companion (M{sub 2} = 3.60 ± 0.03 M{sub ⊙}, R{sub 2} = 26.6 ± 0.2 R{sub ⊙}). Within the observational uncertainties both stars have the same effective temperature of 6030 ± 150 K. Evolutionary tracks place both stars inside the classical Cepheid instability strip, but it is likely that future improved temperature estimates will move the stable giant companion just beyond the red edge of the instability strip. Within current observational and theoretical uncertainties, both stars fit on a 205 Myr isochrone arguing for their common age. From our model, we determine a value of the projection factor of p = 1.37 ± 0.07 for the Cepheid in the OGLE-LMC562.05.9009 system. This is the second Cepheid for which we could measure its p-factor with high precision directly from the analysis of an eclipsing binary system, which represents an important contribution toward a better calibration of Baade-Wesselink methods of distance determination for Cepheids.

  14. Ridge Regression and Other Kernels for Genomic Selection with R Package rrBLUP

    Directory of Open Access Journals (Sweden)

    Jeffrey B. Endelman

    2011-11-01

    Full Text Available Many important traits in plant breeding are polygenic and therefore recalcitrant to traditional marker-assisted selection. Genomic selection addresses this complexity by including all markers in the prediction model. A key method for the genomic prediction of breeding values is ridge regression (RR, which is equivalent to best linear unbiased prediction (BLUP when the genetic covariance between lines is proportional to their similarity in genotype space. This additive model can be broadened to include epistatic effects by using other kernels, such as the Gaussian, which represent inner products in a complex feature space. To facilitate the use of RR and nonadditive kernels in plant breeding, a new software package for R called rrBLUP has been developed. At its core is a fast maximum-likelihood algorithm for mixed models with a single variance component besides the residual error, which allows for efficient prediction with unreplicated training data. Use of the rrBLUP software is demonstrated through several examples, including the identification of optimal crosses based on superior progeny value. In cross-validation tests, the prediction accuracy with nonadditive kernels was significantly higher than RR for wheat ( L. grain yield but equivalent for several maize ( L. traits.

  15. Mitochondrial electron transport chain is involved in microcystin-RR induced tobacco BY-2 cells apoptosis.

    Science.gov (United States)

    Huang, Wenmin; Li, Dunhai; Liu, Yongding

    2014-09-01

    Microcystin-RR (MC-RR) has been suggested to induce apoptosis in tobacco BY-2 cells through mitochondrial dysfunction including the loss of mitochondrial membrane potential (ΔΨm). To further elucidate the mechanisms involved in MC-RR induced apoptosis in tobacco BY-2 cells, we have investigated the role of mitochondrial electron transport chain (ETC) as a potential source for reactive oxygen species (ROS). Tobacco BY-2 cells after exposure to MC-RR (60mg/L) displayed apoptotic changes in association with an increased production of ROS and loss of ΔΨm. All of these adverse effects were significantly attenuated by ETC inhibitors including Rotenone (2μmol/L, complex I inhibitor) and antimycin A (0.01μmol/L, complex III inhibitor), but not by thenoyltrifluoroacetone (5μmol/L, complex II inhibitor). These results suggest that mitochondrial ETC plays a key role in mediating MC-RR induced apoptosis in tobacco BY-2 cells through an increased mitochondrial production of ROS. Copyright © 2014. Published by Elsevier B.V.

  16. Build-up of actinides in irradiated fuel rods of the ET-RR-1 reactor

    Energy Technology Data Exchange (ETDEWEB)

    Adib, M.; Naguib, K.; Morcos, H.N

    2001-09-01

    The content concentrations of actinides are calculated as a function of operating reactor regime and cooling time at different percentage of fuel burn-up. The build-up transmutation equations of actinides content in an irradiated fuel are solved numerically .A computer code BAC was written to operate on a PC computer to provide the required calculations. The fuel element of 10% {sup 235}U enrichment of ET-RR-1 reactor was taken as an example for calculations using the BAC code. The results are compared with other calculations for the ET-RR-1 fuel rod. An estimation of fissile build-up content of a proposed new fuel of 20% {sup 235}U enrichment for ET-RR-1 reactor is given. The sensitivity coefficients of build-up plutonium concentrations as a function of cross-section data uncertainties are also calculated.

  17. Entropy Analysis of RR and QT Interval Variability during Orthostatic and Mental Stress in Healthy Subjects

    Directory of Open Access Journals (Sweden)

    Mathias Baumert

    2014-12-01

    Full Text Available Autonomic activity affects beat-to-beat variability of heart rate and QT interval. The aim of this study was to explore whether entropy measures are suitable to detect changes in neural outflow to the heart elicited by two different stress paradigms. We recorded short-term ECG in 11 normal subjects during an experimental protocol that involved head-up tilt and mental arithmetic stress and computed sample entropy, cross-sample entropy and causal interactions based on conditional entropy from RR and QT interval time series. Head-up tilt resulted in a significant reduction in sample entropy of RR intervals and cross-sample entropy, while mental arithmetic stress resulted in a significant reduction in coupling directed from RR to QT. In conclusion, measures of entropy are suitable to detect changes in neural outflow to the heart and decoupling of repolarisation variability from heart rate variability elicited by orthostatic or mental arithmetic stress.

  18. Degradation of microcystin-RR using boron-doped diamond electrode

    International Nuclear Information System (INIS)

    Zhang Chunyong; Fu Degang; Gu Zhongze

    2009-01-01

    Microcystins (MCs), produced by blue-green algae, are one of the most common naturally occurring toxins found in natural environment. The presence of MCs in drinking water sources poses a great threat to people's health. In this study, the degradation behavior of microcystin-RR on boron-doped diamond (BDD) electrode was investigated under galvanostatic conditions. Such parameters as reaction time, supporting electrolyte and applied current density were varied in order to determine their effects on this oxidation process. The experimental results revealed the suitability of electrochemical processes employing BDD electrode for removing MC-RR from the solution. However, the efficient removal of MC-RR only occurred in the presence of sodium chloride that acted as redox mediators and the reaction was mainly affected by the chloride concentration (c NaCl ) and applied current density (I appl ). Full and quick removal of 0.50 μg/ml MC-RR in solution was achieved when the operating conditions of c NaCl and I appl were 20 mM and 46.3 mA/cm 2 , or 35 mM and 18.2 mA/cm 2 respectively. The kinetics for MC-RR degradation followed a pesudo-first order reaction in most cases, indicating the process was under mass transfer control. As a result of its excellent performance, the BDD technology could be considered as a promising alternative to promote the degradation of MC-RR than chlorination in drinking water supplies.

  19. Adipose tissue (P)RR regulates insulin sensitivity, fat mass and body weight.

    Science.gov (United States)

    Shamansurova, Zulaykho; Tan, Paul; Ahmed, Basma; Pepin, Emilie; Seda, Ondrej; Lavoie, Julie L

    2016-10-01

    We previously demonstrated that the handle-region peptide, a prorenin/renin receptor [(P)RR] blocker, reduces body weight and fat mass and may improve insulin sensitivity in high-fat fed mice. We hypothesized that knocking out the adipose tissue (P)RR gene would prevent weight gain and insulin resistance. An adipose tissue-specific (P)RR knockout (KO) mouse was created by Cre-loxP technology using AP2-Cre recombinase mice. Because the (P)RR gene is located on the X chromosome, hemizygous males were complete KO and had a more pronounced phenotype on a normal diet (ND) diet compared to heterozygous KO females. Therefore, we challenged the female mice with a high-fat diet (HFD) to uncover certain phenotypes. Mice were maintained on either diet for 9 weeks. KO mice had lower body weights compared to wild-types (WT). Only hemizygous male KO mice presented with lower total fat mass, higher total lean mass as well as smaller adipocytes compared to WT mice. Although food intake was similar between genotypes, locomotor activity during the active period was increased in both male and female KO mice. Interestingly, only male KO mice had increased O2 consumption and CO2 production during the entire 24-hour period, suggesting an increased basal metabolic rate. Although glycemia during a glucose tolerance test was similar, KO males as well as HFD-fed females had lower plasma insulin and C-peptide levels compared to WT mice, suggesting improved insulin sensitivity. Remarkably, all KO animals exhibited higher circulating adiponectin levels, suggesting that this phenotype can occur even in the absence of a significant reduction in adipose tissue weight, as observed in females and, thus, may be a specific effect related to the (P)RR. (P)RR may be an important therapeutic target for the treatment of obesity and its associated complications such as type 2 diabetes.

  20. Nahid Sırrı Örik’in Romanlarında Aile

    OpenAIRE

    Sayar, Feyza

    2013-01-01

    In this study, The six novels of Nahid Sırrı Örik Kıskanmak, Yıldız Olmak Kolay mı?, Tersine Giden Yol, Gece Olmadan, Sultan Hamid Düşerken, Kozmopolitler were examined in terms of family approach. In the first section of the study, Nahid Sırrı Örik's life, art and works were mentioned. In the second section, generally novels in Turkish Literature which are on the subject of family were mentioned. In the third section, the plot is studied. In the fourth section family and in the fifth sect...

  1. Probabilistic safety analysis for control rod drive system of ET-RR-1

    International Nuclear Information System (INIS)

    Nasr, M.; Nasser, O.

    1988-01-01

    The International Atomic Energy Agency (IAEA) co-ordinated a Research programme on Probabilistic Safety Analysis (PSA) for research reactors; with the participation of several countries. In the framework of this project (Project Int. 9/063) the Egyptian Atomic Energy Authority decided to perform a PSA study on the ET-RR-1 (Egypt Thermal Research Reactor). The study is conducted in collaboration between the nuclear regulatory and safety centre (NRSC) and the reactor department of the nuclear research centre at Inchass. The present work is a part of the PSA study on ET-RR- it is concerning a probabilistic safety analysis of the control rod drive mechanism

  2. Lignification of the plant and seed quality of RR soybeans sprayed with herbicide glyphosate Lignificação da planta e qualidade de sementes de soja RR pulverizadas com herbicida glifosato

    Directory of Open Access Journals (Sweden)

    Cristiane Fortes Gris

    2013-04-01

    Full Text Available Differences in levels of lignin in the plant between conventional and transgenic cultivars RR has been reported by several authors, however, there are few studies evaluating the influence of spraying of glyphosate on the lignin in the plant and RR soybean seeds. The aim of this study was to evaluate the physiological quality of RR transgenic soybean seeds and the lignin contents of plants sprayed with the herbicide glyphosate. The assays were conducted both in greenhouse and field in the municipality of Lavras, MG, in the agricultural year 2007/08. The experiment was arranged in a splitplot design with four replicates, considering the treatments hand weeding and herbicide glyphosate as plots, and five RR soybean cultivars (BRS 245 RR, BRS 247 RR, Valiosa RR, Silvânia RR and Baliza RR as splitplots. In the greenhouse, the cultivars tested were BRS 245 RR and Valiosa RR in a randomized block design with four replicates. The sprayings were carried out at stages V3, V7 and early R5 (3L/ha. The 1000 seed weight, mechanical injury, germination and germination velocity index, emergence velocity index, accelerated aging, electrical conductivity and water soaking seed test, lignin content in the seed coat, in the stem and legumes were determined. The spraying of glyphosate herbicide, in greenhouse and field, did not alter the physiological quality of seeds and the lignin contents in the plant.Diferenças nos teores de lignina na planta entre cultivares transgênicos RR e convencionais, tem sido relatadas, por vários autores, no entanto, são escassos os trabalhos avaliando a influência da aplicação do glifosato sobre os teores de lignina na planta e em sementes de soja RR. Neste sentido, objetivou-se, com este trabalho, avaliar a qualidade fisiológica de sementes de soja transgênica RR e os teores de lignina de plantas submetidas à pulverização com o herbicida glifosato. Os ensaios foram conduzidos em casa de vegetação e em campo, no munic

  3. Mass and p-factor of the Type II Cepheid OGLE-LMC-T2CEP-098 in a Binary System

    Science.gov (United States)

    Pilecki, Bogumił; Gieren, Wolfgang; Smolec, Radosław; Pietrzyński, Grzegorz; Thompson, Ian B.; Anderson, Richard I.; Bono, Giuseppe; Soszyński, Igor; Kervella, Pierre; Nardetto, Nicolas; Taormina, Mónica; Stȩpień, Kazimierz; Wielgórski, Piotr

    2017-06-01

    We present the results of a study of the type II Cepheid (P puls = 4.974 days) in the eclipsing binary system OGLE-LMC-T2CEP-098 (P orb = 397.2 days). The Cepheid belongs to the peculiar W Vir group, for which the evolutionary status is virtually unknown. It is the first single-lined system with a pulsating component analyzed using the method developed by Pilecki et al. We show that the presence of a pulsator makes it possible to derive accurate physical parameters of the stars even if radial velocities can be measured for only one of the components. We have used four different methods to limit and estimate the physical parameters, eventually obtaining precise results by combining pulsation theory with the spectroscopic and photometric solutions. The Cepheid radius, mass, and temperature are 25.3+/- 0.2 {R}⊙ , 1.51+/- 0.09 {M}⊙ , and 5300+/- 100 {{K}}, respectively, while its companion has a similar size (26.3 {R}⊙ ), but is more massive (6.8 {M}⊙ ) and hotter (9500 K). Our best estimate for the p-factor of the Cepheid is 1.30+/- 0.03. The mass, position on the period-luminosity diagram, and pulsation amplitude indicate that the pulsating component is very similar to the Anomalous Cepheids, although it has a much longer period and is redder in color. The very unusual combination of the components suggest that the system has passed through a mass-transfer phase in its evolution. More complicated internal structure would then explain its peculiarity. This paper includes data gathered with the 6.5 m Magellan Clay Telescope at Las Campanas Observatory, Chile.

  4. Stability of UV exposed RR-P3BT films by spectroscopic ellipsometry

    International Nuclear Information System (INIS)

    Diware, Mangesh S.; Byun, J. S.; Hwang, S. Y.; Kim, T. J.; Kim, Y. D.

    2013-01-01

    Stability of regioregular poly(3-butylthiophene) (RR-P3BT) films under irradiation of ultra-violet (UV) light has been studied by spectroscopic ellipsometry at room temperature. Consistent decrease in dielectric function with UV exposure time showed the degree of degradation of polymer. This work suggests that, protective methods are mandatory to use this kind of material in optical devices.

  5. 78 FR 54149 - Airworthiness Directives; Rolls-Royce plc (RR) Turbofan Engines

    Science.gov (United States)

    2013-09-03

    ... Airworthiness Directives; Rolls-Royce plc (RR) Turbofan Engines AGENCY: Federal Aviation Administration (FAA... service information identified in this AD, contact Rolls-Royce plc, Corporate Communications, P.O. Box 31... per hour. Replacement parts are estimated to cost about $2,271 per engine. Based on these figures, we...

  6. 76 FR 65136 - Airworthiness Directives; Rolls-Royce plc (RR) Turbofan Engines

    Science.gov (United States)

    2011-10-20

    ... Airworthiness Directives; Rolls-Royce plc (RR) Turbofan Engines AGENCY: Federal Aviation Administration (FAA... information identified in this AD, contact Rolls-Royce plc, Corporate Communications, P.O. Box 31, Derby... 8, 2011, to perform the inspection. Costs of Compliance Based on the service information, we...

  7. 76 FR 52288 - Airworthiness Directives; Rolls-Royce plc (RR) Trent 800 Series Turbofan Engines

    Science.gov (United States)

    2011-08-22

    ...-0836; Directorate Identifier 2010-NE-38-AD] RIN 2120-AA64 Airworthiness Directives; Rolls-Royce plc (RR... plc, P.O. Box 31, Derby, DE24 8BJ, United Kingdom: telephone 44 (0) 1332 242424; fax 44 (0) 1332... based on those comments. We will post all comments we receive, without change, to http://www.regulations...

  8. Analysis of R-R intervals in patients with atrial fibrillation at rest and during exercise

    NARCIS (Netherlands)

    Bootsma, B.K.; Hoelen, A.J.; Strackee, J.; Meijler, F.L.

    Serial autocorrelation functions and histograms of R-R intervals in patients with atrial fibrillation, with and without digitalis, at rest and during exercise, were produced by a computer. At rest with and without digitalis the first and higher order coefficients did not differ from zero. During

  9. Measure of the QT-RR Dynamic Coupling in Patients with the Long QT Syndrome

    Czech Academy of Sciences Publication Activity Database

    Halámek, Josef; Couderc, J. P.; Jurák, Pavel; Vondra, Vlastimil; Zareba, W.; Viščor, Ivo; Leinveber, P.

    2012-01-01

    Roč. 17, č. 4 (2012), s. 323-330 ISSN 1082-720X R&D Projects: GA MŠk ME09050 Institutional support: RVO:68081731 Keywords : Long QT syndrome * Dynamic QT-RR coupling * Holter recording * QT adaptation * QT parameters Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 1.084, year: 2012

  10. Influence of Age and Aerobic Fitness on the Multifractal Characteristics of Electrocardiographic RR Time-Series

    Directory of Open Access Journals (Sweden)

    Michael James Lewis

    2013-05-01

    Full Text Available Multifractal properties of electrocardiographic inter-beat (RR time-series offer insight into its long-term correlation structure, independently of RR variability. Here we quantify multifractal characteristics of RR data during 24-hour diurnal-nocturnal activity in healthy participants. We tested the hypotheses that (1 age, gender and aerobic fitness influence RR multifractal properties, and that (2 these are influenced by circadian variation.Seventy adults (39 males aged 19-58 years and of various fitness levels were monitored using 24-hour ECG. Participants were dichotomised by median age and fitness for sub-group analysis. Gender and fitness were independent of age (p=0.1, p>0.5. Younger/older group ages were substantially different (p<0.0005 and were independent of gender and fitness. Multifractality was quantified using the probability spectrum of Hölder exponents (h, from which modal h (h* and the full-width and half-widths at half-maximum measures (FWHM, HWHM+ and HWHM- were derived. FWHM decreased (p=0.004 and h* increased (p=0.011 in older people, indicating diminished long-range RR correlations and weaker anti-persistent behavior. Anti-persistent correlation (h* was strongest in the youngest/fittest individuals and weakest in the oldest/least fit individuals (p=0.015. Long-range correlation (HWHM+/FWHM was strongest in the fittest males and weakest in the least fit females (p=0.007-0.033.Multifractal RR characteristics in our healthy participants showed strong age-dependence with diminished long-range anti-persistent correlation in older people. Circadian variation of these characteristics was influenced by fitness and gender: fitter males and females of all ages had the greatest degree of multifractality or long-range order. Multifractal characterisation appears to be a useful method for exploring the physiological basis of long-term correlation structure in RR time-series as well as the benefits thereon of physical fitness training.

  11. QT-RR relationships and suitable QT correction formulas for halothane-anesthetized dogs.

    Science.gov (United States)

    Tabo, Mitsuyasu; Nakamura, Mikiko; Kimura, Kazuya; Ito, Shigeo

    2006-10-01

    Several QT correction (QTc) formulas have been used for assessing the QT liability of drugs. However, they are known to under- and over-correct the QT interval and tend to be specific to species and experimental conditions. The purpose of this study was to determine a suitable formula for halothane-anesthetized dogs highly sensitive to drug-induced QT interval prolongation. Twenty dogs were anesthetized with 1.5% halothane and the relationship between the QT and RR intervals were obtained by changing the heart rate under atrial pacing conditions. The QT interval was corrected for the RR interval by applying 4 published formulas (Bazett, Fridericia, Van de Water, and Matsunaga); Fridericia's formula (QTcF = QT/RR(0.33)) showed the least slope and lowest R(2) value for the linear regression of QTc intervals against RR intervals, indicating that it dissociated changes in heart rate most effectively. An optimized formula (QTcX = QT/RR(0.3879)) is defined by analysis of covariance and represents a correction algorithm superior to Fridericia's formula. For both Fridericia's and the optimized formula, QT-prolonging drugs (d,l-sotalol, astemizole) showed QTc interval prolongation. A non-QT-prolonging drug (d,l-propranolol) failed to prolong the QTc interval. In addition, drug-induced changes in QTcF and QTcX intervals were highly correlated with those of the QT interval paced at a cycle length of 500 msec. These findings suggest that Fridericia's and the optimized formula, although the optimized is a little bit better, are suitable for correcting the QT interval in halothane-anesthetized dogs and help to evaluate the potential QT prolongation of drugs with high accuracy.

  12. A COMPREHENSIVE, WIDE-FIELD STUDY OF PULSATING STARS IN THE CARINA DWARF SPHEROIDAL GALAXY

    Energy Technology Data Exchange (ETDEWEB)

    Vivas, A. Katherina [Centro de Investigaciones de Astronomía (CIDA), Apartado Postal 264, Mérida 5101-A (Venezuela, Bolivarian Republic of); Mateo, Mario, E-mail: akvivas@cida.ve, E-mail: mmateo@umich.edu [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States)

    2013-12-01

    We report the detection of 388 pulsating variable stars (and some additional miscellaneous variables) in the Carina dwarf spheroidal galaxy over an area covering the full visible extent of the galaxy and extending a few times beyond its photometric (King) tidal radius along the direction of its major axis. Included in this total are 340 newly discovered dwarf Cepheids (DCs), which are mostly located ∼2.5 mag below the horizontal branch and have very short periods (<0.1 days), typical of their class and consistent with their location on the upper part of the extended main sequence of the younger populations of the galaxy. Several extra-tidal DCs were found in our survey up to a distance of ∼1° from the center of Carina. Our sample also includes RR Lyrae stars and anomalous Cepheids, some of which were found outside the galaxy's tidal radius as well. This supports past works that suggest that Carina is undergoing tidal disruption. We use the period-luminosity relationship for DCs to estimate a distance modulus of μ{sub 0} = 20.17 ± 0.10 mag, in very good agreement with the estimate from RR Lyrae stars. We find some important differences in the properties of the DCs of Carina and those in Fornax and the LMC, the only extragalactic samples of DCs currently known. These differences may reflect a metallicity spread, depth along the line of sight, and/or different evolutionary paths of the DC stars.

  13. Globular clusters - Fads and fallacies

    International Nuclear Information System (INIS)

    White, R.E.

    1991-01-01

    The types of globular clusters observed in the Milky Way Galaxy are described together with their known characteristics, with special attention given to correcting the erroneous statements made earlier about globular clusters. Among these are the following statements: the Galaxy is surrounded by many hundreds of globular clusters; all globular clusters are located toward the Galactic center, all globular clusters are metal poor and move about the Galaxy in highly elliptical paths; all globular clusters contain RR Lyrae-type variable stars, and the RR Lyrae stars found outside of globulars have come from cluster dissolution or ejection; all of the stars in a given cluster were born at the same time and have the same chemical composition; X-ray globulars are powered by central black holes; and the luminosity functions for globular clusters are well defined and well determined. Consideration is given to the fact that globular clusters in the Magellanic Clouds differ from those in the Milky Way by their age distribution and that the globulars of the SMC differ from those of the LMC

  14. [The characteristics of RR-Lorenz plot in persistent atrial fibrillation patients complicating with escape beats and rhythm].

    Science.gov (United States)

    Pan, Yunping; Zhang, Fangfang; Liu, Ru; Jing, Yan; Shen, Jihong; Li, Zhongjian; Zhu, Huaijie

    2014-06-01

    To explore the characteristics of RR-Lorenz plot in persistent atrial fibrillation (AF) patients complicating with escape beats and rhythm though ambulatory electrocardiogram. The 24-hour ambulatory electrocardiogram of 291 persistent AF patients in second affiliated hospital of Zhengzhou university from July 2005 to April 2013 were retrospectively analyzed and the RR interval and the QRS wave were measured. Patients were divided into two groups according to the distribution of the RR-Lorenz point [AF without escape beats and rhythm group (Group A, n = 259) and AF with escape beats and rhythm group (Group B, n = 32)]. The characteristics of RR-Lorenz plot between the two groups were compared. (1) Fan-shaped RR-Lorenz plots were evidenced in Group A. (2)In Group B, 30 cases showed fan-shaped with L-shaped and a short dense rods along 45° line. The proportion of escape beats and rhythm was 0.28% (275/98 369) -14.06% (11 263/80 112) . The other 2 cases in group B showed no typical RR-Lorenz plots features. RR-Lorenz plot could help to quickly diagnose persistent AF complicating with escape beats and rhythm according to the typical RR-Lorenz plot characteristics in 24-hour ambulatory electrocardiogram.

  15. 76 FR 78805 - Airworthiness Directives; Rolls-Royce plc (RR) RB211-Trent 800 Series Turbofan Engines

    Science.gov (United States)

    2011-12-20

    ... Airworthiness Directives; Rolls-Royce plc (RR) RB211-Trent 800 Series Turbofan Engines AGENCY: Federal Aviation... all Rolls-Royce plc (RR) RB211-Trent 800 Series Turbofan Engines. This AD results from mandatory... inspection of the FOHE mounts. We did not change the AD based on this comment. Request To Add Requirement To...

  16. Biofuel and Biochemical Analysis of Amphora coffeaeformis RR03, a Novel Marine Diatom, Cultivated in an Open Raceway Pond

    Directory of Open Access Journals (Sweden)

    Muthu Ganesan Rajaram

    2018-05-01

    Full Text Available (1 Background: To increase the biochemical productivity and to reduce the production cost of microalgal biodiesel, this study aimed to investigate the effects of CO2 on biomass, fatty acids, carbon-hydrogen, and biochemical accumulation of the marine diatom, Amphora coffeaeformis RR03 (A. coffeaeformis RR03. (2 Methods: Fatty acid composition of the dry biomass of A. coffeaeformis RR03 was analysed using Gas chromatography-mass spectrometry (GC-MS. (3 Results: The results showed that A. coffeaeformis RR03 contained high biomass productivity and biochemical composition in different cultivation conditions. A. coffeaeformis RR03 showed maximum growth of 5.2 × 106/mL on 21st day cultivation under CO2 supply. The bio-crude oil production from A. coffeaeformis RR03 was 36.19 megajoule (MJ. GC-MS analysis found that the dry biomass of A. coffeaeformis RR03 contained maximum of 47.72% fatty acids of 16-octadecanoic acid methyl ester (10:12 and 19.58% pentadecanoic acid, 13-methyl-, and methyl ester (9.24. (4 Conclusion: The results of this study may suggest that a novel diatom of A. coffeaeformis RR03 could be a suitable candidate for biocrude production in order to meet the future demand of energy.

  17. Similar uptake profiles of microcystin-LR and -RR in an in vitro human intestinal model

    International Nuclear Information System (INIS)

    Zeller, P.; Clement, M.; Fessard, V.

    2011-01-01

    Highlights: → First description of in vitro cellular uptake of MCs into intestinal cells. → OATP 3A1 and OATP 4A1 are expressed in Caco-2 cell membranes. → MC-LR and MC-RR show similar uptake in Caco-2 cells. → MCs are probably excreted from Caco-2 cells by an active mechanism. -- Abstract: Microcystins (MCs) are cyclic hepatotoxins produced by various species of cyanobacteria. Their structure includes two variable amino acids (AA) leading to more than 80 MC variants. In this study, we focused on the most common variant, microcystin-LR (MC-LR), and microcystin-RR (MC-RR), a variant differing by only one AA. Despite their structural similarity, MC-LR elicits higher liver toxicity than MC-RR partly due to a discrepancy in their uptake by hepatic organic anion transporters (OATP 1B1 and 1B3). However, even though ingestion is the major pathway of human exposure to MCs, intestinal absorption of MCs has been poorly addressed. Consequently, we investigated the cellular uptake of the two MC variants in the human intestinal cell line Caco-2 by immunolocalization using an anti-MC antibody. Caco-2 cells were treated for 30 min to 24 h with several concentrations (1-50 μM) of both variants. We first confirmed the localization of OATP 3A1 and 4A1 at the cell membrane of Caco-2 cells. Our study also revealed a rapid uptake of both variants in less than 1 h. The uptake profiles of the two variants did not differ in our immunostaining study neither with respect to concentration nor the time of exposure. Furthermore, we have demonstrated for the first time the nuclear localization of MC-RR and confirmed that of MC-LR. Finally, our results suggest a facilitated uptake and an active excretion of MC-LR and MC-RR in Caco-2 cells. Further investigation on the role of OATP 3A1 and 4A1 in MC uptake should be useful to clarify the mechanism of intestinal absorption of MCs and contribute in risk assessment of cyanotoxin exposure.

  18. The Carnegie Hubble Program: The Distance and Structure of the SMC as Revealed by Mid-Infrared Observations of Cepheids

    Science.gov (United States)

    Scowcroft, Victoria; Freedman, Wendy L.; Madore, Barry F.; Monson, Andy; Persson, S. E.; Rich, Jeff; Seibert, Mark; Rigby, Jane R.

    2016-01-01

    Using Spitzer observations of classical Cepheids we have measured the true average distance modulus of the Small Magellanic Cloud (SMC) to be18.96 +/- 0.01 stat +/- 0.03sys mag (corresponding to 62+/- 0.3kpc), which is 0.48 +/- 0.01 mag more distant than the LMC. This is in agreement with previous results from Cepheid observations, as well as with measurements from other indicators such as RR Lyrae stars and the tip of the red giant branch. Utilizing the properties of the mid-infrared Leavitt Law we measured precise distances to individual Cepheids in the SMC, and have confirmed that the galaxy is tilted and elongated such that its eastern side is up to20 kpc closer than its western side. This is in agreement with the results from red clump stars and dynamical simulations of the Magellanic Clouds and Stream.

  19. Annotation and analysis of a large cuticular protein family with the R&R Consensus in Anopheles gambiae

    Directory of Open Access Journals (Sweden)

    He Ningjia

    2008-01-01

    Full Text Available Abstract Background The most abundant family of insect cuticular proteins, the CPR family, is recognized by the R&R Consensus, a domain of about 64 amino acids that binds to chitin and is present throughout arthropods. Several species have now been shown to have more than 100 CPR genes, inviting speculation as to the functional importance of this large number and diversity. Results We have identified 156 genes in Anopheles gambiae that code for putative cuticular proteins in this CPR family, over 1% of the total number of predicted genes in this species. Annotation was verified using several criteria including identification of TATA boxes, INRs, and DPEs plus support from proteomic and gene expression analyses. Two previously recognized CPR classes, RR-1 and RR-2, form separate, well-supported clades with the exception of a small set of genes with long branches whose relationships are poorly resolved. Several of these outliers have clear orthologs in other species. Although both clades are under purifying selection, the RR-1 variant of the R&R Consensus is evolving at twice the rate of the RR-2 variant and is structurally more labile. In contrast, the regions flanking the R&R Consensus have diversified in amino-acid composition to a much greater extent in RR-2 genes compared with RR-1 genes. Many genes are found in compact tandem arrays that may include similar or dissimilar genes but always include just one of the two classes. Tandem arrays of RR-2 genes frequently contain subsets of genes coding for highly similar proteins (sequence clusters. Properties of the proteins indicated that each cluster may serve a distinct function in the cuticle. Conclusion The complete annotation of this large gene family provides insight on the mechanisms of gene family evolution and clues about the need for so many CPR genes. These data also should assist annotation of other Anopheles genes.

  20. The use of Wavelight® Contoura to create a uniform cornea: the LYRA protocol. Part 3: the results of 50 treated eyes

    Directory of Open Access Journals (Sweden)

    Motwani M

    2017-05-01

    Full Text Available Manoj Motwani Motwani LASIK Institute, San Diego, CA, USA Purpose: To demonstrate how using the Wavelight Contoura measured astigmatism and axis eliminates corneal astigmatism and creates uniformly shaped corneas. Patients and methods: A retrospective analysis was conducted of the first 50 eyes to have bilateral full WaveLight® Contoura LASIK correction of measured astigmatism and axis (vs conventional manifest refraction, using the Layer Yolked Reduction of Astigmatism Protocol in all cases. All patients had astigmatism corrected, and had at least 1 week of follow-up. Accuracy to desired refractive goal was assessed by postoperative refraction, aberration reduction via calculation of polynomials, and postoperative visions were analyzed as a secondary goal. Results: The average difference of astigmatic power from manifest to measured was 0.5462D (with a range of 0–1.69D, and the average difference of axis was 14.94° (with a range of 0°–89°. Forty-seven of 50 eyes had a goal of plano, 3 had a monovision goal. Astigmatism was fully eliminated from all but 2 eyes, and 1 eye had regression with astigmatism. Of the eyes with plano as the goal, 80.85% were 20/15 or better, and 100% were 20/20 or better. Polynomial analysis postoperatively showed that at 6.5 mm, the average C3 was reduced by 86.5% and the average C5 by 85.14%. Conclusions: Using WaveLight® Contoura measured astigmatism and axis removes higher order aberrations and allows for the creation of a more uniform cornea with accurate removal of astigmatism, and reduction of aberration polynomials. WaveLight® Contoura successfully links the refractive correction layer and aberration repair layer using the Layer Yolked Reduction of Astigmatism Protocol to demonstrate how aberration removal can affect refractive correction. Keywords: WaveLight Contoura, topographic guided ablation, LASIK, PRK, uniform cornea, Contoura with LYRA Protocol, measured astigmatism

  1. VARIABLE O VI AND N V EMISSION FROM THE X-RAY BINARY LMC X-3: HEATING OF THE BLACK HOLE COMPANION

    International Nuclear Information System (INIS)

    Song Limin; Tripp, Todd M.; Wang, Q. Daniel; Yao Yangsen; Cui Wei; Xue Yongquan; Orosz, Jerome A.; Steeghs, Danny; Steiner, James F.; Torres, Manuel A. P.; McClintock, Jeffrey E.

    2010-01-01

    Based on high-resolution ultraviolet spectroscopy obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE) and the Cosmic Origins Spectrograph, we present new detections of O VI and N V emission from the black hole X-ray binary (XRB) system LMC X-3. We also update the ephemeris of the XRB using recent radial velocity measurements obtained with the echelle spectrograph on the Magellan-Clay telescope. We observe significant velocity variability of the UV emission, and we find that the O VI and N V emission velocities follow the optical velocity curve of the XRB. Moreover, the O VI and N V intensities regularly decrease between binary phase = 0.5 and 1.0, which suggests that the source of the UV emission is increasingly occulted as the B star in the XRB moves from superior to inferior conjunction. These trends suggest that illumination of the B star atmosphere by the intense X-ray emission from the accreting black hole creates a hot spot on one side of the B star, and this hot spot is the origin of the O VI and N V emission. However, the velocity semiamplitude of the ultraviolet emission, K UV ∼ 180 km s -1 , is lower than the optical semiamplitude; this difference could be due to rotation of the B star. Comparison of the FUSE observations taken in 2001 November and 2004 April shows a significant change in the O VI emission characteristics: in the 2001 data, the O VI region shows both broad and narrow emission features, while in 2004 only the narrow O VI emission is clearly present. Rossi X-ray Timing Explorer data show that the XRB was in a high/soft state in the 2001 November epoch but was in a transitional state in 2004 April, so the shape of the X-ray spectrum might change the properties of the region illuminated on the B star and thus change the broad versus narrow characteristics of the UV emission. If our hypothesis about the origin of the highly ionized emission is correct, then careful analysis of the emission occultation could, in principle

  2. Research performed at the ET-RR-1 reactor using the neutron scattering equipment

    International Nuclear Information System (INIS)

    Adib, M.; Maayouf, R.M.A.; Abdel-Kawy, A.

    1990-02-01

    This report represents the results of studies and measurements, performed at the ET-RR-1 reactor, using the neutron scattering equipment supplied by the IAEA according to the technical assistance project EGY/1/11/10. The results of these studies, starting in 1980 and continuing to date, are discussed; the use of the equipment, both as a neutron monochromator and fixed scattering angle spectrometer, is also assessed. (author). 19 refs, 17 figs

  3. Gated current integrator for the beam in the RR barrier buckets

    Energy Technology Data Exchange (ETDEWEB)

    A. Cadorn; C. Bhat; J. Crisp

    2003-06-10

    At the Fermilab Recycler Ring (RR), the antiproton (pbar) beam will be stored azimuthally in different segments created by barrier buckets. The beam in each segment may have widely varying intensities. They have developed a gated integrator system to measure the beam intensity in each of the barrier bucket. Here they discuss the design of the system and the results of beam measurements using the integrator.

  4. GAUGE R&R FOR AN OPTICAL MICROMETER INDUSTRIAL TYPE MACHINE

    Directory of Open Access Journals (Sweden)

    Georgia A. Louka

    2010-12-01

    Full Text Available The measurement of the uncertainty of a metric system, as 'Gauge R&R' and the collation of results between the Xbar & R and the ANOVA method, are extended in this essay. In an academic school laboratory we accomplished a sequence of measurements with the use of an Optical Micrometer Industrial Type Machine (MUL 300. This paper analyzes the measurement system that used in the laboratory and checks the reasons of the variability's provocation that observed in the machine, between the theoretical calculations and measurements. In order to find out this problem, we will use the 'Gage Repeatability and Reproducibility' technique of Measurement System Analysis (M.S.A.. This technique uses analysis of variance. In addition, will use Minitab program in order to find out the factors that we have in the whole experiment as enlarge the problem of measurements. In this paper, a statistical method using the correlation between Gage R&R and process capability indices is proposed for evaluating the adequacy of the acceptance criteria of P/T ratio. Finally, a comparative analysis has also been performed for evaluating the accuracy of Gage R&R between two methods (ANOVA and R- Xbar method. Hopefully, the results of this research can provide a useful reference for quality practitioners in various industries.

  5. Studies for the radiation levels and shielding in RR73, RR77 and UJ76 in IR7 for collimation phase 1 - 035

    CERN Document Server

    Tsoulou, A; Ferrari, A; CERN. Geneva. AB Department

    2005-01-01

    The Collimation project is one of the most crucial for the LHC performance. 54 movable, two-sided collimators will be placed in two insertions, i.e. IR3 and IR7, which will be among the most radioactive in the LHC. For a normal machine operation, it is essential that the electronics do not degrade or fail â€" at least very often â€" due to irradiation. The radiation levels initially estimated in IR7 (RR73/77 and UJ76) were too high for the electronics to tolerate. A shielding study was necessary to be done, in parallel with the study for the absorber positions. This article summarizes the shielding proposed and the radiation levels calculated for the final collimator and absorber positions as indicated by the FLUKA team.

  6. Studies for the radiation levels and shielding in RR73, RR77 and UJ76 in IR7 for collimation phase 1 - 372

    CERN Document Server

    Tsoulou, A; Ferrari, A

    2005-01-01

    The Collimation project is one of the most crucial for the LHC performance. 54 movable, two-sided collimators will be placed in two insertions, i.e. IR3 and IR7, which will be among the most radioactive in the LHC. For a normal machine operation, it is essential that the electronics do not degrade or fail â€" at least very often â€" due to irradiation. The radiation levels initially estimated in IR7 (RR73/77 and UJ76) were too high for the electronics to tolerate. A shielding study was necessary to be done, in parallel with the study for the absorber positions. This article summarizes the shielding proposed and the radiation levels calculated for the final collimator and absorber positions as indicated by the FLUKA team.

  7. PODAAC-TEMSC-LMC01

    Data.gov (United States)

    National Aeronautics and Space Administration — The monthly mass grids provided here contain global water storage anomalies relative to a time-mean as derived from GRACE time-variable gravity data. This dataset...

  8. Rodent Research-1 (RR1) NASA Validation Flight: Mouse extensor digitorum longus muscle transcriptomic and epigenomic data

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA s Rodent Research (RR) project is playing a critical role in advancing biomedical research on the physiological effects of space environments. Due to the...

  9. Rodent Research-1 (RR1) NASA Validation Flight: Mouse tibialis anterior muscle transcriptomic proteomic and epigenomic data

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA s Rodent Research (RR) project is playing a critical role in advancing biomedical research on the physiological effects of space environments. Due to the...

  10. Comparison of spontaneous vs. metronome-guided breathing on assessment of vagal modulation using RR variability.

    Science.gov (United States)

    Bloomfield, D M; Magnano, A; Bigger, J T; Rivadeneira, H; Parides, M; Steinman, R C

    2001-03-01

    R-R interval variability (RR variability) is increasingly being used as an index of autonomic activity. High-frequency (HF) power reflects vagal modulation of the sinus node. Since vagal modulation occurs at the respiratory frequency, some investigators have suggested that HF power cannot be interpreted unless the breathing rate is controlled. We hypothesized that HF power during spontaneous breathing would not differ significantly from HF power during metronome-guided breathing. We measured HF power during spontaneous breathing in 20 healthy subjects and 19 patients with heart disease. Each subject's spontaneous breathing rate was determined, and the calculation of HF power was repeated with a metronome set to his or her average spontaneous breathing rate. There was no significant difference between the logarithm of HF power measured during spontaneous and metronome-guided breathing [4.88 +/- 0.29 vs. 5.29 +/- 0.30 ln(ms(2)), P = 0.32] in the group as a whole and when patients and healthy subjects were examined separately. We did observe a small (9.9%) decrease in HF power with increasing metronome-guided breathing rates (from 9 to 20 breaths/min). These data indicate that HF power during spontaneous and metronome-guided breathing differs at most by very small amounts. This variability is several logarithmic units less than the wide discrepancies observed between healthy subjects and cardiac patients with a heterogeneous group of cardiovascular disorders. In addition, HF power is relatively constant across the range of typical breathing rates. These data indicate that there is no need to control breathing rate to interpret HF power when RR variability (and specifically HF power) is used to identify high-risk cardiac patients.

  11. Multipurpose RTOF Fourier diffractometer at the ET-RR-1 reactor

    International Nuclear Information System (INIS)

    Maayouf, R.M.A.; Tiitta, A.T.

    1993-09-01

    The present work represents a further study of the basic RTOF Fourier multipurpose diffractometer, to start with, at the ET-RR-1 reactor. The functions of the suggested arrangement are thoroughly discussed and the possibilities if its expansion are also assessed. The flexibility of the arrangement allows its further expansion both for stress measurement at 90 deg. scattering angle with two detector banks at opposite sides of the incident beam and for operation in the transmission diffraction mode. (orig.). (19 refs., 10 figs., 1 tab.)

  12. A low background pulsed neutron polyenergetic beam at the ET-RR-1 reactor

    International Nuclear Information System (INIS)

    Adib, M.; Abdel-Kawy, A.; Habib, N.; Abu-El-Ela, M.; Wahba, M.; Kilany, M.

    1991-12-01

    A low background pulsed neutron polyenergetic thermal beam at ET-RR-1 is produced by a rotor and rotating collimator suspended in magnetic fields. Each of them is mounted on its mobile platform and whose centres are 66 cm apart, rotating synchronously at speeds up to 16000 rpm. It was found that the neutron burst produced by the rotor with almost 100% transmission passes through the collimator, when the rotation phase between them is 28.8 deg. Moreover the background level achieved at the detector position is low, constant and free from peaks due to gamma rays and fast neutrons accompanying the reactor thermal beam. (author). 12 refs, 3 figs

  13. Detailed evaluation of ET-RR-2 neutronic design: approach to criticality

    International Nuclear Information System (INIS)

    Ashoub, N.; Amin, E.

    2000-01-01

    The ET-RR-2 safety analysis evaluation effort included the assessment of the reactor core nuclear design parameters. The present work complements the previous effort of neutronic calculations using NCNSRC computer code packages. This paper is the first in comprehensive neutronic calculation assessment up to the equilibrium core. It deals with evaluation of neutronic calculation submitted during the early phase of the licensing process; namely the proposal to assemble the first critical core, calculation of power peaking factor and determination of detailed energy group flux distribution in the core particularly in the cobalt irradiation position. The neutronic design criteria are examined qualitatively and quantitatively in the present paper

  14. Ageing problems and renovation programme of ET-RR-1 reactor

    International Nuclear Information System (INIS)

    Khattab, M.S.; Sultan, M.A.

    1995-01-01

    Based on Practical Experience gained from interfacing ageing systems in addition to operating new systems, current problems could be deduced whenever in-service inspection are carried out. This paper summarizes the in-service inspection made, and the proposed programme of rehabilitation of mechanical system in the ET-RR-1 research reactor at Inshass. Exchangeable experience in solving common problems in similar reactors play an important role in the effectiveness of such rehabilitation programme. The paper summarizes also the modernization of control, measuring and radiation monitoring system already carried out at the reactor. (orig.)

  15. Influence of foliar fertilization with manganese on germination, vigor and storage time of RR soybean seeds

    Directory of Open Access Journals (Sweden)

    Vanessa Leonardo Ignácio

    2015-10-01

    Full Text Available ABSTRACTThis study aimed to evaluate the influence of foliar fertilizer doses containing Mn of phenological stages of suggested application in RR soybeans, to recover management damages with glyphosate at postemergence application on seed vigor in post-harvest and post six months storage. The seeds originated from a field experiment conducted , which included two applications of glyphosate, concomitant with foliar fertilizer in growth stages V4 and V6, with 0.00, 113.50 and 227.00 mg ha-1doses of Mn2+. Germination, GSI (Germination Speed Index, electrical conductivity tests and the first count of seeds were conducted. The application of Mn did not affect the physiological quality of RR soy in postharvest. However, in post-storage, higher doses of Mn had a negative effect on tests of abnormal seedlings, GSI and electrical conductivity. The applications of Mn, regardless of the developmental stage, did not interfere in the germination and first count tests, with and without storage. The electrical conductivity test showed a higher correlation with the seed germination test in the post-harvest treatment.

  16. Toothpick test: a methodology for the detection of RR soybean plants1

    Directory of Open Access Journals (Sweden)

    Fabiana Mota da Silva

    Full Text Available Due to the large increase in the area cultivated with genetically modified soybean in Brazil, it has become necessary to determine methods that are fast and efficient for detecting these cultivars. The aim of this work was to test the efficiency of the toothpick method in the detection of RR soybean plants, as well as to distinguish between cultivars, for sensitivity caused by herbicide. Ten transgenic soybean cultivars, resistant to the active ingredient glyphosate, and ten conventional soybean cultivars were used. Toothpicks soaked in glyphosate were applied to all the plants at stage V6 and evaluations were made at 2, 4, 6, 8 and 10 days after application (DAA. The effects of the glyphosate on the cultivars, and the symptoms of phytotoxicity caused in the transgenic plants were evaluated by means of grading scales. The toothpick test is effective in identifying RR soybean cultivars and also in separating them into groups by sensitivity to the symptoms caused by the glyphosate.

  17. Dysregulated Homeostasis of Acetylcholine Levels in Immune Cells of RR-Multiple Sclerosis Patients

    Directory of Open Access Journals (Sweden)

    Maria Di Bari

    2016-11-01

    Full Text Available Multiple sclerosis (MS is characterized by pro-inflammatory cytokine production. Acetylcholine (ACh contributes to the modulation of central and peripheral inflammation. We studied the homeostasis of the cholinergic system in relation to cytokine levels in immune cells and sera of relapsing remitting-MS (RR-MS patients. We demonstrated that lower ACh levels in serum of RR-MS patients were inversely correlated with the increased activity of the hydrolyzing enzymes acetylcholinesterase (AChE and butyrylcholinesterase (BuChE. Interestingly, the expression of the ACh biosynthetic enzyme and the protein carriers involved in non-vesicular ACh release were found overexpressed in peripheral blood mononuclear cells of MS patients. The inflammatory state of the MS patients was confirmed by increased levels of TNFα, IL-12/IL-23p40, IL-18. The lower circulating ACh levels in sera of MS patients are dependent on the higher activity of cholinergic hydrolyzing enzymes. The smaller ratio of ACh to TNFα, IL-12/IL-23p40 and IL-18 in MS patients, with respect to healthy donors (HD, is indicative of an inflammatory environment probably related to the alteration of cholinergic system homeostasis.

  18. Thermal neutron flux distribution in ET-RR-2 reactor thermal column

    Directory of Open Access Journals (Sweden)

    Imam Mahmoud M.

    2002-01-01

    Full Text Available The thermal column in the ET-RR-2 reactor is intended to promote a thermal neutron field of high intensity and purity to be used for following tasks: (a to provide a thermal neutron flux in the neutron transmutation silicon doping, (b to provide a thermal flux in the neutron activation analysis position, and (c to provide a thermal neutron flux of high intensity to the head of one of the beam tubes leading to the room specified for boron thermal neutron capture therapy. It was, therefore, necessary to determine the thermal neutron flux at above mentioned positions. In the present work, the neutron flux in the ET-RR-2 reactor system was calculated by applying the three dimensional diffusion depletion code TRITON. According to these calculations, the reactor system is composed of the core, surrounding external irradiation grid, beryllium block, thermal column and the water reflector in the reactor tank next to the tank wall. As a result of these calculations, the thermal neutron fluxes within the thermal column and at irradiation positions within the thermal column were obtained. Apart from this, the burn up results for the start up core calculated according to the TRITION code were compared with those given by the reactor designer.

  19. Properties of Asymmetric Detrended Fluctuation Analysis in the time series of RR intervals

    Science.gov (United States)

    Piskorski, J.; Kosmider, M.; Mieszkowski, D.; Krauze, T.; Wykretowicz, A.; Guzik, P.

    2018-02-01

    Heart rate asymmetry is a phenomenon by which the accelerations and decelerations of heart rate behave differently, and this difference is consistent and unidirectional, i.e. in most of the analyzed recordings the inequalities have the same directions. So far, it has been established for variance and runs based types of descriptors of RR intervals time series. In this paper we apply the newly developed method of Asymmetric Detrended Fluctuation Analysis, which so far has mainly been used with economic time series, to the set of 420 stationary 30 min time series of RR intervals from young, healthy individuals aged between 20 and 40. This asymmetric approach introduces separate scaling exponents for rising and falling trends. We systematically study the presence of asymmetry in both global and local versions of this method. In this study global means "applying to the whole time series" and local means "applying to windows jumping along the recording". It is found that the correlation structure of the fluctuations left over after detrending in physiological time series shows strong asymmetric features in both magnitude, with α+ physiological data after shuffling or with a group of symmetric synthetic time series.

  20. A study for providing additional storage spaces to ET-RR-1 spent fuel

    International Nuclear Information System (INIS)

    El-Kady, A.; Ashoub, N.; Saleh, H.G.

    1995-01-01

    The ET-RR-1 reactor spent fuel storage pool is a trapezoidal aluminum tank concrete shield and of capacity 10 m 3 . It can hold up to 60 fuel assemblies. The long operation history of the ET-RR-1 reactor resulted in a partially filled spent fuel storage with the remaining spaces not enough to host a complete load from the reactor. This work have been initiated to evaluate possible alternative solutions for providing additional storage spaces to host the available EK-10 fuel elements after irradiation and any foreseen fuel in case of reactor upgrading. Several alternate solutions have been reviewed and decision on the most suitable one is under study. These studies include criticality calculation of some suggested alternatives like reracking the present spent fuel storage pool and double tiering by the addition of a second level storage rack above the existing rack. The two levels may have different factor. Criticality calculation of the double tiering possible accident was also studied. (author)

  1. Thermal performance of Egypt's research reactor core (ET-RR-1)

    International Nuclear Information System (INIS)

    Khattab, M.; Mariy, A.

    1986-01-01

    The steady state thermal performance of the ET-RR-1 core system is theoretically investigated by different models describing the heat flux and the coolant mass flow rate. The magnitude of the heat generated by a fuel element depends upon its position in the core. Normal and uniform distributions for heat flux and coolant mass flow rate are considered. The clad and coolant temperatures at different core positions are evaluated and compared with the experimental measurements at different operating conditions. The results indicated large discrepancy between the predicted and the experimental results. Therefore, the previous models and the experimental results are evaluated in order to develop the best model that describes the thermal performance of the ET-RR-1 core. The adapted model gives 99.5% significant confidence limit. The effect of increasing the heat flux or decreasing the mass flow rate by 20% from its maximum recommended operating condition is tested and discussed. Also, the thermal behaviour towards increasing the reactor power more than its maximum operating condition is discussed. The present work could also be used in extending the investigation to other PWR reactor operating conditions

  2. Optimization of Exopolysaccharide Production by Lactobacillus delbrueckii subsp. bulgaricus RR Grown in a Semidefined Medium

    Science.gov (United States)

    Kimmel, Stacy A.; Roberts, Robert F.; Ziegler, Gregory R.

    1998-01-01

    The optimal fermentation temperature, pH, and Bacto-casitone (Difco Laboratories, Detroit, Mich.) concentration for production of exopolysaccharide by Lactobacillus delbrueckii subsp. bulgaricus RR in a semidefined medium were determined by using response surface methods. The design consisted of 20 experiments, 15 unique combinations, and five replications. All fermentations were conducted in a fermentor with a 2.5-liter working volume and were terminated when 90% of the glucose in the medium had been consumed. The population of L. delbrueckii subsp. bulgaricus RR and exopolysaccharide content were measured at the end of each fermentation. The optimum temperature, pH, and Bacto-casitone concentration for exopolysaccharide production were 38°C, 5, and 30 g/liter, respectively, with a predicted yield of 295 mg of exopolysaccharide/liter. The actual yield under these conditions was 354 mg of exopolysaccharide/liter, which was within the 95% confidence interval (217 to 374 mg of exopolysaccharide/liter). An additional experiment conducted under optimum conditions showed that exopolysaccharide production was growth associated, with a specific production at the endpoint of 101.4 mg/g of dry cells. Finally, to obtain material for further characterization, a 100-liter fermentation was conducted under optimum conditions. Twenty-nine grams of exopolysaccharide was isolated from centrifuged, ultrafiltered fermentation broth by ethanol precipitation. PMID:9464404

  3. Estimated long lived isotope activities in ET-RR-1 reactor structural materials for decommissioning study

    International Nuclear Information System (INIS)

    Ashoub, N.; Saleh, H.

    1995-01-01

    The first Egyptian research reactor, ET-RR-1 is tank type with light water as a moderator, coolant and reflector. Its nominal power is 2MWt and the average thermal neutron flux is 10 13 n/cm 2 sec -1 . Its criticality was on the fall of 1961. The reactor went through several modifications and updating and is still utilized for experimental research. A plan for decommissioning of ET-RR-1 reactor should include estimation of radioactivity in structural materials. The inventory will help in assessing the radiological consequences of decommissioning. This paper presents a conservative calculation to estimate the activity of the long lived isotopes which can be produced by neutron activation. The materials which are presented in significant quantities in the reactor structural materials are aluminum, cast iron, graphite, ordinary and iron shot concrete. The radioactivity of each component is dependent not only upon the major elements, but also on the concentration of the trace elements. The main radioactive inventory are expected to be from 60 Co and 55 Fe which are presented in aluminium as trace elements and in large quantities in other construction materials. (author)

  4. O desflorestamento ao longo da rodovia BR-174 (Manaus/Am - Boa Vista/Rr / The deforestation along the BR-174 road (Manaus / Am - Boa Vista / Rr

    Directory of Open Access Journals (Sweden)

    Eduardo Paschoal Rodrigues,

    2011-12-01

    Full Text Available Pesquisas indicam que o processo de desflorestamento na Amazônia está associado à abertura de estradas, uma vez que favorece o fluxo migratório, a ocupação de terras e a exploração de madeiras. O objetivo deste trabalho foi analisar o desflorestamento no entorno (20 km da rodovia BR-174 para um período de 30 anos (1978-2008. Foram utilizadas imagens LANDSAT, dados do INPE/PRODES, dados cartográficos e econômicos e trabalhos de campo. Os resultados demonstraram um crescimento do desflorestamento, passando de 622,15 km2 em 1978 para 2.618,58 km2 em 2008. As principais atividades econômicas dos municípios por onde passa a BR-174, exceto Manaus, estão associadas à agropecuária. Em Manaus, o desflorestamento ocorre principalmente na área urbana. Ainda que a construção da BR-174 esteja associada a processos de desflorestamento, a rodovia possui grande importância para a região, pois foi responsável pela ligação terrestre entre duas capitais do norte do país (Manaus/AM e Boa Vista/RR e possibilitou formar comunidades onde são desenvolvidas atividades econômicas e sociais. A criação de projetos de desenvolvimento sustentável é o grande desafio dos governos locais, para agregar valor aos empreendimentos existentes e desenvolver novos modelos de uso e ocupação na região.

  5. Human action contribution to ET-RR-II reactor systems unstems unavailability

    International Nuclear Information System (INIS)

    Sabek, M.G.

    2001-01-01

    This paper gives a study on the human action contribution to the systems unavailability of ET-RR-II reactor as a result of the test and maintenance procedures. The human contribution is expressed in terms of Fussel-Vesely importance which is defined by the probability that event is contributing to system failure (unavailability). The human error basic events contribution was analyzed for all initiating events and systems fault trees. The calculations result shows a high contribution value (61%) for the human error to systems unavailability. This means that the operator and the maintenance people should be highly qualified trained. Moreover, there should be programs for continuous training. Also, the procedures of tests and maintenance should be in a simple way and clear in order to minimize the contribution of the human errors. The calculations were done using the IRRAS cods

  6. The double rotor neutron monochromator facility at the ET-RR-1 reactor

    International Nuclear Information System (INIS)

    Adib, M.; Maayouf, R.M.A.; Abdel-Kawy, A.; Gwaily, S.E.; Hamouda, I.

    1983-01-01

    A double rotor neutron monochromator recently installed in front of one of the ET-RR-1 reactor horizontal channels is described. The system consists of two rotors, suspended in magnetic field, spinning at speeds up to 16000 rpm with a constant phase angle relative to each producing bursts of monochromatic neutrons at the sample. Each of the rotors, 32 cm in diameter and 27 Kg in weight, has two slits to produce two neutron bursts per revolution. The slits are with radius of curvature 65.65 cm and 7 x 10 sq.mm cross-sectional area. The jitters of the phase between the rotors were measured at different rotation rates and were found not to exceed +- 1.5 μsec. The transmission function of one rotor system was measured and found to be in agreement with that theoretically predicted. (Auth.)

  7. Optimization of a neutron guide facility for the ET-RR-1 reactor. Vol. 2

    Energy Technology Data Exchange (ETDEWEB)

    Maayouf, R M.A.; El-Kady, A S [Reactor and Nutron Physics Department, Nuclear Research Center, Atomic Energy Authority, Cairo, (Egypt)

    1996-03-01

    This work deals with the optimization calculations carried out for a neutron guide facility at the ET-RR-1 reactor. The facility is intended for delivering slow neutrons, emitted from one of the ET-RR-1 reactor horizontal channels, to a Fourier RTOF diffractometer. Accordingly, wavelength-dependent neutron reflectivity calculations were carried out for Cu, Ge, natural Ni, and {sup 58} Ni; materials which are usually used as reflecting surfaces of the neutron guide mirror channel walls. The results of calculations were in favour of {sup 58} Ni as the best coating of the neutron guide mirror channel walls. {sup 58} Ni gives a characteristic wavelength {lambda}{sup *}=1.36 A degree of the neutron guide. This also leads to a value of the neutron flux, at the neutron guide output, 1.4 times more than that one resulting from coating the mirror channel walls with natural nickel. The optimized neutron guide, for effective luminosity value 2.4 x 10{sup 6}, was found to be 22 m in length with mirror channel walls coated with {sup 58} Ni. Such optimization of the neutron guide length, along which a curvature 3345 m in radius, leads to a strong suppression of the background of gamma quanta and fast neutrons. Besides, the neutron wavelength range, 1.O{Alpha} degree -4.O{Alpha} degree, produced by the optimized neutron guide facility allows for neutron diffraction measurements at D values between 0.71{Alpha} degree -2.33 {Alpha} degree. 5 figs., 1 tab.

  8. R-R interval variations influence the degree of mitral regurgitation in dogs with myxomatous mitral valve disease

    DEFF Research Database (Denmark)

    Reimann, M. J.; Moller, J. E.; Haggstrom, J.

    2014-01-01

    of congestive heart failure due to MMVD. The severity of MR was evaluated in apical four-chamber view using colour Doppler flow mapping (maximum % of the left atrium area) and colour Doppler M-mode (duration in ms). The influence of the ratio between present and preceding R-R interval on MR severity......Mitral regurgitation (MR) due to myxomatous mitral valve disease (MMVD) is a frequent finding in Cavalier King Charles Spaniels (CKCSs). Sinus arrhythmia and atrial premature complexes leading to R-R interval variations occur in dogs. The aim of the study was to evaluate whether the duration...... of the RR interval immediately influences the degree of MR assessed by echocardiography in dogs. Clinical examination including echocardiography was performed in 103 privately-owned dogs: 16 control Beagles, 70 CKCSs with different degree of MR and 17 dogs of different breeds with clinical signs...

  9. The Half RR Rule: A Poor Rule of Thumb and Not a Risk Assessment Tool for QT Interval Prolongation.

    Science.gov (United States)

    Berling, Ingrid; Isbister, Geoffrey K

    2015-10-01

    Measuring the QT interval on an electrocardiogram (ECG) is integral to risk assessment of Torsade de Pointes (TdP). This study aimed to investigate the accuracy of the 1/2 RR rule as a risk assessment tool for drug-induced TdP, comparing it to the QT nomogram, Bazett's corrected QT (QTcB), and Fridericia's corrected QT (QTcF). The authors calculated sensitivity and specificity of the 1/2 RR rule using a published data set of 129 cases of drug-induced TdP and 316 controls (noncardiotoxic overdoses), compared to the QT nomogram, QTcB > 500 msec and QTcF > 500 msec. To further determine the value of the 1/2 RR rule, its observed positive, and negative agreement were calculated when compared to the QT nomogram for determining an abnormal QT in eight samples of different drugs in overdose. The sensitivity and specificity of the 1/2 RR rule were 88% (95% confidence interval [CI] = 80% to 93%) and 53% (95% CI = 47% to 58%), respectively, compared to the QT nomogram (sensitivity = 97%, 95% CI = 92% to 99%; specificity = 99%, 95% CI = 97% to 100%). It was also less sensitive than QTcB > 500 msec and had a lower specificity than QTcB > 500 msec and QTcF > 500 msec. In drug overdose patients, the 1/2 RR rule had poor observed agreement averaging 41%, which was mainly due to poor positive agreement, except for amisulpride where there was good agreement. The 1/2 RR rule was not as sensitive as the QT nomogram or QTcB > 500 msec for drug-induced TdP. It had poor positive agreement in almost all overdose patients, resulting in over half of patients receiving unnecessary cardiac monitoring and repeat ECGs. © 2015 by the Society for Academic Emergency Medicine.

  10. Polimorfismo do gene tp53 no códon 72 em pacientes com suspeita de LMC Codon 72 polymorphism of the TP53 gene in patients suspected to have CML

    Directory of Open Access Journals (Sweden)

    Camila S. Hamú

    2007-12-01

    Full Text Available A leucemia mielóide crônica (LMC é uma doença proliferativa do sistema hematopoiético, caracterizada pela expansão clonal de uma célula-tronco primitiva e pluripotente denominada stem cell. Este tipo de leucemia está associado, em 90% dos casos, à translocação t(9;22(q34;q11. Essa alteração cromossômica estrutural codifica para uma proteína quimérica BCR-ABL, que confere às células leucêmicas uma alta resistência à morte, independente do agente indutor desse processo. A proteína p53 é uma reguladora transcricional induzida por danos no DNA, fato que resulta na parada do ciclo celular com conseqüente ativação de mecanismos de reparo ou mesmo na indução à apoptose. As mutações no gene TP53 são as alterações genéticas mais comuns em tumores malignos humanos. O presente estudo teve como objetivo genotipar e determinar a freqüência alélica do polimorfismo do TP53 no códon 72 (arginina - Arg e prolina - Pro, em pacientes com suspeita de LMC, pela Reação em Cadeia da Polimerase. Desta forma, os resultados indicaram que 73,4% (23/30 dos pacientes apresentaram homozigose para arginina (Arg/Arg e 26,6% (7/30 heterozigose (Arg/Pro. Não foi encontrado nenhum paciente homozigoto para prolina (Pro/Pro. Os resultados obtidos sugerem que o polimorfismo do gene TP53 no códon 72 não é um fator de risco importante para a iniciação, promoção e progressão da LMC.Chronic myeloid leukemia (CML is a proliferative disorder of the hematopoietic system characterized by clonal expansion of a primitive and pluripotent stem cell. In this type of leukemia, up to 90% of all cases is associated to a specific chromosomal translocation, t(9;22(q34;q11. The genomic alteration results in a chimeric protein, BCR-ABL, that confers a high resistance leukemia cells to death, independent of the induction mechanism of this process. Protein p53 is a transcriptional factor expressed after DNA damage which ceases cell cycle progression and

  11. Structural characterisation of the exopolysaccharide produced by Lactobacillus delbrückii subspecies bulgaricus rr grown in skimmed milk

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Gruter, M.; Leeflang, B.R.; Kuiper, J.; Kamerling, J.P.

    1993-01-01

    The exopolysaccharide of Lactobacillus delbrückii subsp. bulgaricus rr. isolated from skimmed milk, is a heteropolymer of D-galactopyranosyl, D-glucopyranosyl, and L-rhamnopyranosyl residues in the molar ratio 5:1:1. The structure was established by linkage analysis and 1D and 2D NMR spectroscopy of

  12. Vasyl' Danylenko, ed. Ukrains'ka intelihentsiia i vlada: Zvedennia sekretnoho viddilu DPU USRR 1927–1929 rr.

    Directory of Open Access Journals (Sweden)

    Olena Palko

    2015-01-01

    Full Text Available Vasyl' Danylenko, ed. Ukrains'ka intelihentsiia i vlada: Zvedennia sekretnoho viddilu DPU USRR 1927–1929 rr. [The Ukrainian Intelligentsia and State Power. Summaries of the Secret Department of State Political Administration of the Ukrainian SSR for 1927–1929]. Kyiv: Tempora, 2012. 756 pp. Illustrations. Appendix. Indexes. 70 UAH, cloth.

  13. 75 FR 61361 - Airworthiness Directives; Rolls-Royce plc (RR) RB211-535 Series Turbofan Engines

    Science.gov (United States)

    2010-10-05

    ...-0994; Directorate Identifier 2009-NE-39-AD] RIN 2120-AA64 Airworthiness Directives; Rolls-Royce plc (RR...-Royce plc., P.O. Box 31, Derby, DE24 8BJ, United Kingdom; Telephone: 011 44 1332 242424, Fax: 011 44... based on those comments. We will post all comments we receive, without change, to http://www.regulations...

  14. 76 FR 65997 - Airworthiness Directives; Rolls-Royce plc (RR) RB211-535 Series Turbofan Engines

    Science.gov (United States)

    2011-10-25

    ...-0994; Directorate Identifier 2009-NE-39-AD] RIN 2120-AA64 Airworthiness Directives; Rolls-Royce plc (RR... Friday, except Federal holidays. For service information identified in this AD, contact Rolls-Royce plc.... Based on these figures, we estimate the cost of this proposed AD on U.S. operators to be $1,499,400. FAA...

  15. 75 FR 45560 - Airworthiness Directives; Rolls-Royce plc (RR) RB211-Trent 800 Series Turbofan Engines

    Science.gov (United States)

    2010-08-03

    ...-0755; Directorate Identifier 2010-NE-12-AD] RIN 2120-AA64 Airworthiness Directives; Rolls-Royce plc (RR... based on engine thrust rating but now based on operating shaft speeds) introduced by Rolls- Royce. The...-Royce plc, P.O. Box 31, Derby, DE24 8BJ, United Kingdom: Telephone 44 (0) 1332 242424; fax 44 (0) 1332...

  16. 77 FR 10355 - Airworthiness Directives; Rolls-Royce plc (RR) RB211-Trent 800 Series Turbofan Engines

    Science.gov (United States)

    2012-02-22

    ... Airworthiness Directives; Rolls-Royce plc (RR) RB211-Trent 800 Series Turbofan Engines AGENCY: Federal Aviation... service of certain critical engine parts based on reduced life limits. This new AD reduces the life limits... effective March 28, 2012. ADDRESSES: For service information identified in this AD, contact Rolls-Royce plc...

  17. 77 FR 4648 - Airworthiness Directives; Rolls-Royce plc (RR) RB211-535 Series Turbofan Engine

    Science.gov (United States)

    2012-01-31

    ... Airworthiness Directives; Rolls-Royce plc (RR) RB211-535 Series Turbofan Engine AGENCY: Federal Aviation... identified in this AD, contact Rolls-Royce plc, P.O. Box 31, Derby, DE24 8BJ, United Kingdom; phone: 011 44... parts are required. Based on these figures, we estimate the cost of this AD on U.S. operators to be $1...

  18. 75 FR 63727 - Airworthiness Directives; Rolls-Royce plc (RR) RB211-524 Series Turbofan Engines

    Science.gov (United States)

    2010-10-18

    ...-0162; Directorate Identifier 2004-NE-19-AD] RIN 2120-AA64 Airworthiness Directives; Rolls-Royce plc (RR...-2251. Contact Rolls-Royce plc, P.O. Box 31, Derby, DE24 8BJ, United Kingdom; telephone: 011-44-1332... would cost $0. Based on these figures, we estimate the total cost of the AD to U.S. operators would be...

  19. 76 FR 68663 - Airworthiness Directives; Rolls-Royce plc (RR) RB211-Trent 800 Series Turbofan Engines

    Science.gov (United States)

    2011-11-07

    ...-0755; Directorate Identifier 2010-NE-12-AD] RIN 2120-AA64 Airworthiness Directives; Rolls-Royce plc (RR... Rolls-Royce plc, Corporate Communications, P.O. Box 31, Derby, England, DE248BJ; phone: 011-44-1332... date and may amend this proposed AD based on those comments. We will post all comments we receive...

  20. 77 FR 1009 - Airworthiness Directives; Rolls-Royce plc (RR) RB211-524 Series Turbofan Engines

    Science.gov (United States)

    2012-01-09

    ... Airworthiness Directives; Rolls-Royce plc (RR) RB211-524 Series Turbofan Engines AGENCY: Federal Aviation... 5, 2005). ADDRESSES: For service information identified in this AD, contact Rolls-Royce plc, P.O...,000. Based on these figures, we estimate the total cost of the AD to U.S. operators to be $4,206,960...

  1. 76 FR 72650 - Airworthiness Directives; Rolls-Royce plc (RR) RB211 Trent 800 Series Turbofan Engines

    Science.gov (United States)

    2011-11-25

    ...-0959; Directorate Identifier 2011-NE-25-AD] RIN 2120-AA64 Airworthiness Directives; Rolls-Royce plc (RR... holidays. Fax: (202) 493-2251. Contact Rolls-Royce plc, P.O. Box 31, Derby, DE24 8BJ, United Kingdom; phone... AD. We will consider all comments received by the closing date and may amend this proposed AD based...

  2. Comparative Studies on the pH Dependence of DOW of Microcystin-RR and -LR Using LC-MS

    Directory of Open Access Journals (Sweden)

    Gaodao Liang

    2011-01-01

    Full Text Available Microcystins (MCs are well known worldwide as hepatotoxins produced by cyanobacteria, but little is known about the physicochemical properties of these compounds. The dependence of the n-octanol/water distribution ratio (DOW of MC-RR and -LR to pH was measured by high-performance liquid chromatography combined with mass spectrometry (LC-MS. There was a remarkable difference in such relationships between MC-RR and -LR. The log DOW of MC-LR decreased from 1.63 at pH 1.0 to -1.26 at pH 6.5, and stabilized between -1.04 and -1.56 at a pH of 6.5~12.0; log DOW of MC-RR varied between -1.24 and -0.67 at a pH of 1.00~4.00, and stabilized between -1.20 and -1.54 at a pH of 4.00~12.00. The difference of hydrophobicity in acidic condition between MC-RR and -LR is important, not only for the analytical method of both toxins, but perhaps also for understanding the difference of toxicity to animals between the two toxins.

  3. A pulsed neutron monochromatic beam at the ET-RR-1 reactor

    International Nuclear Information System (INIS)

    Adib, M.; Abdel-Kawy, A.; Eid, Y.; Maayouf, R.M.A.

    1985-01-01

    A pulsed neutron monochromatic beam, at the ET-RR-1 reactor, is produced by two 32 cm diameter rotors suspended in magnetic fields, whose centres are 126 cm apart rotating at speeds up to 16,000 rev/min. Each of the rotors has two slots, which are of constant cross-section in area - 7x10mm 2 , and are curved so that they have a maximum transmission for neutrons whose speed is 8.2 times that of the rotor tip. The jitter of the phase between the rotors at different rotation rates is found not to exceed +-1 μs. It has been found that both the observed time distribution and the TOF distribution of the neutrons at different rotation rates are in good agreement with the calculated ones. The observed intensity of the monochromatic neutrons of wavelength 2.74+-0.09 A, obtained by the rotors rotating at a speed of 10,500 rev/min with 864+-1 μs difference in phase between them, is 66.8 n/s. This value is found to be less than the predicted one by a factor of 5.5. (author)

  4. Chemical Composition of RR Lyn - an Eclipsing Binary System with Am and λ Boo Type Components

    Science.gov (United States)

    Jeong, Yeuncheol; Yushchenko, Alexander V.; Doikov, Dmytry N.; Gopka, Vira F.; Yushchenko, Volodymyr O.

    2017-06-01

    High-resolution spectroscopic observations of the eclipsing binary system RR Lyn were made using the 1.8 m telescope at the Bohuynsan Optical Astronomical Observatory in Korea. The spectral resolving power was R = 82,000, with a signal to noise ratio of S/N > 150. We found the effective temperatures and surface gravities of the primary and secondary components to be equal to Teff = 7,920 & 7,210 K and log(g) = 3.80 & 4.16, respectively. The abundances of 34 and 17 different chemical elements were found in the atmospheric components. Correlations between the derived abundances with condensation temperatures and the second ionization potentials of these elements are discussed. The primary component is a typical metallic line star with the abundances of light and iron group elements close to solar values, while elements with atomic numbers Z > 30 are overabundant by 0.5-1.5 dex with respect to solar values. The secondary component is a λ Boo type star. In this type of stars, CNO abundances are close to solar values, while the abundance pattern shows a negative correlation with condensation temperatures.

  5. Sympathetic skin response and R-R interval variation in cases with rheumatoid arthritis.

    Science.gov (United States)

    Gozke, E; Erdogan, N; Akyuz, G; Turan, B; Akyuz, E; Us, O

    2003-03-01

    To investigate the autonomic nervus system involvement in cases with rheumatoid arthritis (RA) by assesing sympathetic skin response (SSR) and R-R interval variation (RRIV), 14 healthy women and 10 women with RA, all of them without clinic dysautonomies were examined. SSR's were recorded palmar surface of both hands and soles of both feet, after stimulating median and tibial nerves individually. RRIV's were assessed at rest and during six deep breathing in one minute with electrodes placed on dorsal surfaces of both hands. SSR could not be obtained from lower extremities of one case with RA. We could not find any significant difference between two groups in terms of SSR latencies. RRIV values obtained during deep breathing to those recorded at rest (D%/R%) was found to be significantly lower in RA cases than healthy controls. RRIV values increased with deep breathing in healthy subjects, while they decreased in 50% of the RA cases. We conclude that assessment of SSR and RRIV are valuble methods for revelation of subclinical autonomic involvement in cases with RA.

  6. POPULARIZING EPIC NARRATIVE IN GEORGE R.R. MARTIN'S A GAME OF THRONES

    Directory of Open Access Journals (Sweden)

    Ida Rochani Adi

    2012-11-01

    Full Text Available This research is intended to show the sustainability of epic in latest years of human history through the most phenomenal fantasy in American literature, A Game of Thrones. Along with the capability of human beings in thinking dearly and sensibly, it is commonsensical that people tend to free themselves from irrationality. The reality shows, however, that the existence of epic fantasy still has power in appealing audiences or readers. This is the case with A Game of Thrones written by George RR Martin who was given the award of One of The Most Influential People in 2011 by Time magazine. This qualitative march, using genre approach, finds out that in order to be compatible with today's society, an epic seen in A Game of Thrones, which is commonly known as a story centering on the legendary hero and his heroic deed in oral folk tradition, keeps its power as an epic fantasy narrative through certain archetypes and formulas. Through genre analysis using semiotic approach, the research brings about conclusions that the elements of high fantasy, elements built through rational representation, and a smart combination of convention and invention brings about its popularity. It is also concluded that there is a close relationship between the myth and the mode of people living even in the most modern context.

  7. Expanding the storage capability at ET-RR-1 research reactor at Inshass

    International Nuclear Information System (INIS)

    Sultan, Mariy M.; Khattab, M.

    1999-01-01

    Storing of spent fuel from Test Reactor in developing countries has become a big dilemma for the following reasons: The transportation of spent fuel is very expensive; There are no reprocessing plants in most developing countries; The expanding of existing storage facilities in reactor building require experience that most of developing countries lack; Some political motivations from Nuclear Developed countries intervene which makes the transportation procedures and logistics to those countries difficult. This paper gives the conceptual design of a new spent fuel storage now under construction at Inshass research reactor (ET-RR-1). The location of the new storage facility is chosen to be within the premises of the reactor facility so that both reactor and the new storage are one Material Balance Area. The paper also proposes some ideas that can enhance the transportation and storage of spent fuel of test reactors, such as: Intensifying the role of IAEA in helping countries to get rid of the spent fuel; The initiation of regional spent fuel storage facilities in some developing countries. (author)

  8. 76 FR 20229 - Airworthiness Directives; Rolls-Royce plc (RR) RB211-Trent 768-60 and Trent 772-60 Turbofan Engines

    Science.gov (United States)

    2011-04-12

    ... inspections of the MCD. We are issuing this AD to prevent in-flight engine shutdowns caused by step aside... Airworthiness Directives; Rolls-Royce plc (RR) RB211-Trent 768-60 and Trent 772-60 Turbofan Engines AGENCY... superseding an existing airworthiness directive (AD) for RR RB211-Trent 700 series turbofan engines. That AD...

  9. Dynamics of microcystins-LR and -RR in the phytoplanktivorous silver carp in a sub-chronic toxicity experiment

    International Nuclear Information System (INIS)

    Xie Liqiang; Xie Ping; Ozawa, Kazuhiko; Honma, Takamitsu; Yokoyama, Atsushi; Park, Ho-Dong

    2004-01-01

    A sub-chronic toxicity experiment was conducted to examine tissue distribution and depuration of two microcystins (microcystin-LR and microcystin -RR) in the phytoplanktivorous filter-feeding silver carp during a course of 80 days. Two large tanks (A, B) were used, and in Tank A, the fish were fed naturally with fresh Microcystis viridis cells (collected from a eutrophic pond) throughout the experiment, while in Tank B, the food of the fish were M. viridis cells for the first 40 days and then changed to artificial carp feed. High Performance Liquid Chromatography (HPLC) was used to measure MC-LR and MC-RR in the M. viridis cells, the seston, and the intestine, blood, liver and muscle tissue of silver carp at an interval of 20 days. MC-RR and MC-LR in the collected Microcystis cells varied between 268-580 and 110-292 μg g -1 DW, respectively. In Tank A, MC-RR and MC-LR varied between 41.5-99.5 and 6.9-15.8 μg g -1 DW in the seston, respectively. The maximum MC-RR in the blood, liver and muscle of the fish was 49.7, 17.8 and 1.77 μg g -1 DW, respectively. No MC-LR was detectable in the muscle and blood samples of the silver carp in spite of the abundant presence of this toxin in the intestines (for the liver, there was only one case when a relatively minor quantity was detected). These findings contrast with previous experimental results on rainbow trout. Perhaps silver carp has a mechanism to degrade MC-LR actively and to inhibit MC-LR transportation across the intestines. The depuration of MC-RR concentrations occurred slowly than uptakes in blood, liver and muscle, and the depuration rate was in the order of blood>liver>muscle. The grazing ability of silver carp on toxic cyanobacteria suggests an applicability of using phytoplanktivorous fish to counteract cyanotoxin contamination in eutrophic waters. - Silver carp are tolerant of cyanobacterial toxins, and might be used to control toxic algal blooms in highly eutrophic lakes

  10. Non-linear properties of R-R distributions as a measure of heart rate variability

    International Nuclear Information System (INIS)

    Irurzun, I.M.; Bergero, P.; Cordero, M.C.; Defeo, M.M.; Vicente, J.L.; Mola, E.E.

    2003-01-01

    We analyze the dynamic quality of the R-R interbeat intervals of electrocardiographic signals from healthy people and from patients with premature ventricular contractions (PVCs) by applying different measure algorithms to standardised public domain data sets of heart rate variability. Our aim is to assess the utility of these algorithms for the above mentioned purposes. Long and short time series, 24 and 0.50 h respectively, of interbeat intervals of healthy and PVC subjects were compared with the aim of developing a fast method to investigate their temporal organization. Two different methods were used: power spectral analysis and the integral correlation method. Power spectral analysis has proven to be a powerful tool for detecting long-range correlations. If it is applied in a short time series, power spectra of healthy and PVC subjects show a similar behavior, which disqualifies power spectral analysis as a fast method to distinguish healthy from PVC subjects. The integral correlation method allows us to study the fractal properties of interbeat intervals of electrocardiographic signals. The cardiac activity of healthy and PVC people stems from dynamics of chaotic nature characterized by correlation dimensions d f equal to 3.40±0.50 and 5.00±0.80 for healthy and PVC subjects respectively. The methodology presented in this article bridges the gap between theoretical and experimental studies of non-linear phenomena. From our results we conclude that the minimum number of coupled differential equations to describe cardiac activity must be six and seven for healthy and PVC individuals respectively. From the present analysis we conclude that the correlation integral method is particularly suitable, in comparison with the power spectral analysis, for the early detection of arrhythmias on short time (0.5 h) series

  11. [Primary Study on Predicting the Termination of Paroxysmal Atrial Fibrillation Based on a Novel RdR RR Intervals Scatter Plot].

    Science.gov (United States)

    Lu, Hongwei; Zhang, Chenxi; Sun, Ying; Hao, Zhidong; Wang, Chunfang; Tian, Jiajia

    2015-08-01

    Predicting the termination of paroxysmal atrial fibrillation (AF) may provide a signal to decide whether there is a need to intervene the AF timely. We proposed a novel RdR RR intervals scatter plot in our study. The abscissa of the RdR scatter plot was set to RR intervals and the ordinate was set as the difference between successive RR intervals. The RdR scatter plot includes information of RR intervals and difference between successive RR intervals, which captures more heart rate variability (HRV) information. By RdR scatter plot analysis of one minute RR intervals for 50 segments with non-terminating AF and immediately terminating AF, it was found that the points in RdR scatter plot of non-terminating AF were more decentralized than the ones of immediately terminating AF. By dividing the RdR scatter plot into uniform grids and counting the number of non-empty grids, non-terminating AF and immediately terminating AF segments were differentiated. By utilizing 49 RR intervals, for 20 segments of learning set, 17 segments were correctly detected, and for 30 segments of test set, 20 segments were detected. While utilizing 66 RR intervals, for 18 segments of learning set, 16 segments were correctly detected, and for 28 segments of test set, 20 segments were detected. The results demonstrated that during the last one minute before the termination of paroxysmal AF, the variance of the RR intervals and the difference of the neighboring two RR intervals became smaller. The termination of paroxysmal AF could be successfully predicted by utilizing the RdR scatter plot, while the predicting accuracy should be further improved.

  12. Um exemplo de análise contrastiva: o grafema r/rr em português e italiano

    Directory of Open Access Journals (Sweden)

    Lúcia Fulgêncio

    2011-10-01

    Full Text Available Neste trabalho é apresentado um exemplo de análise contrastiva entre a língua italiana e o português falado no Brasil, do ponto de vista fonético. Tomam-se os sons grafados ou <rr> e examinam-se as suas possibilidades re realização fonética em cada língua, individualmente, identificando o contexto de produção de cada realização fonológica. Posteriormente, comparam-se os sistemas fonológicos das duas línguas quanto a esse aspecto, indicando os ambientes de simetria ou dissimetria estrutural. A evidência dos ambientes onde ocorre dissimetria na realização de /<rr> pode ser útil para o professor de italiano para brasileiros (ou vice-versa, já que provavelmente esses ambientes constituirão pontos de maior dificuldade na aprendizagem da produção.In questo studio si presenta un essempio di analisi contrastiva a livello fonetico tra la ligua italiana e quella portoghese parlata in Brasile. Per ognuna delle due lingue vengono analizzate le possibilità di realizzazione fonetica dei grafemi o <rr> definendo il contesto di ogni realizzazione fonologica. In seguito sono comparati i sistemi fonologici dell’italiano e del portoghese per quanto concerne il tema proposto, e vengono indicati gli ambienti di simmetria e asimmetria strutturale. Mettere in risalto gli ambienti di asimmetria nella realizzazione di /<rr> può riverlarsi di grande utilità al professore di italiano a brasiliani o viceversa, dato che l’apprendimento dei suoni che ne risulta costituisce, probabilmente, non poca difficoltà.

  13. Cloning and expression analysis of transcription factor RrTTG1 related to prickle development in rose (Rosa Rugosa

    Directory of Open Access Journals (Sweden)

    Feng Li-Guo

    2015-01-01

    Full Text Available A prickle is an acuminate protuberance formed by the deformation of plant trichomes together with a few cortical cells. It is a type of multicellular eglandular trichome with special morphology, which originates from the phloem but is not connected to the xylem. Rosa rugosa is an important ornamental/commercial plant and an important raw material in the food and perfume industries. However, the firm prickles on its stems are inconvenient to field management, the harvesting of flowers and garden management. The TTG1 transcription factor related to the development of prickle was isolated from R. rugosa in the present study. Its expression patterns in different tissues and varieties were analyzed. Results showed the expression level of the RrTTG1 gene was highest in the leaves, followed by the stems, but was lower in the pericarps and petals. Moreover, the higher expression level of the RrTTG1 gene in all tissues of the ‘Ciguo rose’, as compared with that of the ‘Weihai wild rose’, follows the results of field morphological observation. Therefore, the RrTTG1 transcription factor is likely to regulate the development of rose prickles. This study allows for further discussion on the molecular mechanisms of prickle formation and development in R. rugosa and provides a molecular basis for the cultivation of roses with fewer or no prickles via genetic engineering.

  14. Spectral Variability of the UXOR Star RR Tau Over 2.5 Magnitudes in V

    Science.gov (United States)

    Rodgers, B.; Wooden, D. H.; Grinin, V. P.; Shakhovskoy, D.

    2000-12-01

    We present moderate resolution optical spectra of the highly variable Herbig Ae star RR Tau over 12 epochs spanning 2.5 magnitudes in V. The data cover most of the optical spectrum from the CaII K line in the blue to the CaII infrared triplet in the far red. Using contemporaneous photometric measurements from two sources, we have reliable estimates of the visual magnitude of the system at each spectral epoch. We find some spectral activity to be closely correlated with photometric variability, while other features are remarkably stable. Significant variability is common in the cores of Hα and Hβ , but is not well correlated with photometric variability. On the other hand, the wings (Δ v>400km/s) of the Balmer lines are quite stable, showing no change in spectral type when compared to Kurucz line profiles. This, along with the constant equivalent width seen in several weak metal lines, suggest that the physical conditions of the underlying continuum source are not changing significantly, despite a factor of ten change in brightness. In contrast, strong low-ionization permitted lines, such as FeII, CaII and NaI, are seen in deep absorption when the star is bright (V <= 12), but disappear during photometric minima to reveal weak emission lines. These absorption lines are not being filled in by the emission but rather are physically disappearing from the system. This could occur, for example, if an obscuring screen moved between the continuum source and the absorbing gas. The [OI]6300 line, a common wind diagnostic, is seen in emission at all epochs, with flux which is roughly constant except increasing slightly when the system is faint. We discuss these data in the context of different scenarios for the photometric variability and find them to be more consistent with the obscuration hypothesis, than changing accretion luminosity. This work is part of the dissertation research of B. Rodgers, which has been funded in large part by a NASA Graduate Student Research

  15. Qualidade fisiológica e teor de lignina no tegumento de sementes de soja convencional e transgênica RR submetidas a diferentes épocas de colheita Physiological quality and lignin content in the coat seeds of conventional and RR transgenic soybean submitted to different harvest periods

    Directory of Open Access Journals (Sweden)

    Cristiane Fortes Gris

    2010-04-01

    Full Text Available Têm-se levantado à hipótese de que cultivares de soja RR possuem teores de lignina superiores aos convencionais, o que proporciona maior resistência a danos mecânicos e maior impermeabilidade do tegumento das sementes. Objetivou-se avaliar a qualidade fisiológica e o teor de lignina no tegumento das sementes de soja convencional e RR colhidas em três épocas, em Lavras-MG. Para tanto, as sementes colhidas nos estádios R7, R8 e após 20 dias de retardamento da colheita (R8+20, foram submetidas aos testes para avaliação da qualidade fisiológica e teor de lignina. As cultivares convencionais e RR avaliadas foram: BRS 133 vs BRS 245 RR, BRS 134 vs BRS 247 RR, Conquista vs Valiosa RR, Celeste vs Baliza RR e Jataí vs Silvânia RR. Foram realizados os testes de peso de mil sementes, germinação, envelhecimento acelerado, condutividade elétrica, dano mecânico, índice de velocidade de emergência, germinação após a imersão das sementes em água e teor de lignina no tegumento de sementes. Com exceção do teor de lignina no tegumento de sementes para o contraste Jataí vs Silvânia RR, não foram observadas diferenças entre os materiais RR e convencional, tendo, neste caso, a cv Silvânia RR apresentado resultados superiores aos da convencional. No entanto, houve diferença de comportamento entre os cultivares quanto à tolerância ao retardamento da colheita. Observou-se redução significativa na porcentagem de germinação e vigor das sementes avaliadas com o retardamento da colheita.One has raised the hypothesis that the RR soybean cultivars posses lignin contents higher than those of the conventional ones. The present work was conducted with the purpose of evaluating the physiological quality and lignin content in the coat of the conventional and RR soybean seeds collected in three times in Lavras-MG. To that end, the seeds collected at stages R7, R8 and after 20 days of collection delay (R8+20 were submitted to the tests for

  16. 76 FR 24793 - Airworthiness Directives; Rolls-Royce plc (RR) RB211-524 Series and RB211 Trent 500, 700, and 800...

    Science.gov (United States)

    2011-05-03

    ... Airworthiness Directives; Rolls-Royce plc (RR) RB211-524 Series and RB211 Trent 500, 700, and 800 Series... the AD. Costs of Compliance Based on the service information, we estimate that this AD would affect...

  17. Processed CTD and Water Sample Data from Research Vessel Roger Revelle, Expedition RR1214, in the NE Pacific in November 2012 (NCEI Accession 0156228)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Expedition RR1214 by research vessel Roger Revelle was primarily a transit from French Polynesia to the US mainland. However, a small scientific program was...

  18. The crystal structure of the AhRR-ARNT heterodimer reveals the structural basis of the repression of AhR-mediated transcription.

    Science.gov (United States)

    Sakurai, Shunya; Shimizu, Toshiyuki; Ohto, Umeharu

    2017-10-27

    2,3,7,8-Tetrachlorodibenzo- p -dioxin and related compounds are extraordinarily potent environmental toxic pollutants. Most of the 2,3,7,8-tetrachlorodibenzo- p -dioxin toxicities are mediated by aryl hydrocarbon receptor (AhR), a ligand-dependent transcription factor belonging to the basic helix-loop-helix (bHLH) Per-ARNT-Sim (PAS) family. Upon ligand binding, AhR forms a heterodimer with AhR nuclear translocator (ARNT) and induces the expression of genes involved in various biological responses. One of the genes induced by AhR encodes AhR repressor (AhRR), which also forms a heterodimer with ARNT and represses the activation of AhR-dependent transcription. The control of AhR activation is critical for managing AhR-mediated diseases, but the mechanisms by which AhRR represses AhR activation remain poorly understood, because of the lack of structural information. Here, we determined the structure of the AhRR-ARNT heterodimer by X-ray crystallography, which revealed an asymmetric intertwined domain organization presenting structural features that are both conserved and distinct among bHLH-PAS family members. The structures of AhRR-ARNT and AhR-ARNT were similar in the bHLH-PAS-A region, whereas the PAS-B of ARNT in the AhRR-ARNT complex exhibited a different domain arrangement in this family reported so far. The structure clearly disclosed that AhRR competitively represses AhR binding to ARNT and target DNA and further suggested the existence of an AhRR-ARNT-specific repression mechanism. This study provides a structural basis for understanding the mechanism by which AhRR represses AhR-mediated gene transcription. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. Prediction of paroxysmal atrial fibrillation using recurrence plot-based features of the RR-interval signal

    International Nuclear Information System (INIS)

    Mohebbi, Maryam; Ghassemian, Hassan

    2011-01-01

    Atrial fibrillation (AF) is the most common cardiac arrhythmia and increases the risk of stroke. Predicting the onset of paroxysmal AF (PAF), based on noninvasive techniques, is clinically important and can be invaluable in order to avoid useless therapeutic intervention and to minimize risks for the patients. In this paper, we propose an effective PAF predictor which is based on the analysis of the RR-interval signal. This method consists of three steps: preprocessing, feature extraction and classification. In the first step, the QRS complexes are detected from the electrocardiogram (ECG) signal and then the RR-interval signal is extracted. In the next step, the recurrence plot (RP) of the RR-interval signal is obtained and five statistically significant features are extracted to characterize the basic patterns of the RP. These features consist of the recurrence rate, length of longest diagonal segments (L max  ), average length of the diagonal lines (L mean ), entropy, and trapping time. Recurrence quantification analysis can reveal subtle aspects of dynamics not easily appreciated by other methods and exhibits characteristic patterns which are caused by the typical dynamical behavior. In the final step, a support vector machine (SVM)-based classifier is used for PAF prediction. The performance of the proposed method in prediction of PAF episodes was evaluated using the Atrial Fibrillation Prediction Database (AFPDB) which consists of both 30 min ECG recordings that end just prior to the onset of PAF and segments at least 45 min distant from any PAF events. The obtained sensitivity, specificity, positive predictivity and negative predictivity were 97%, 100%, 100%, and 96%, respectively. The proposed methodology presents better results than other existing approaches

  20. Mid-Infrared Interferometric Monitoring of Evolved Stars: The Dust Shell Around the Mira Variable RR Aquilae at 13 Epochs

    Science.gov (United States)

    2011-01-01

    photometric and interferometric data. 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT Same as Report (SAR) 18. NUMBER OF...λ = 2.2 μm, Δλ = 0.4 μm) angular size with the Infrared Optical Telescope Array ( IOTA ). The uniform disk diameter (UD) of θUD = 10.73 ± 0.66 mas at...with IOTA in the H-band, and classified RR Aql as a target with no detectable asymmetries. The IRAS flux at 12 μm is 332 Jy. The light curve in the V

  1. The optimum operating conditions of the phased double-rotor facility at the ET-RR-1 reactor

    Energy Technology Data Exchange (ETDEWEB)

    Naguib, K.; Habib, N.; Wahba, M.; Kilany, M.; Adib, M. [National Research Centre, Cairo (Egypt). Reactor and Neutron Physics Dept.

    1997-02-07

    A pulsed neutron polyenergetic thermal beam at ET-RR-1 is produced by a phased double-rotor facility. One of the rotors has two diametrically opposite curved slots, while the second is designed to operate as a rotating collimator. The dimensions of the phased rotating collimator are selected to match the curved slot rotor. The calculated collimator transmissions at different operating conditions are found to be in good agreement with the experimental ones. The optimum operating conditions of the double-rotor facility are deduced. The calculations were carried out using a computer program RCOL. The RCOL was designed in FORTRAN-77 to operate on PCs. (author).

  2. A review on research activities using the SANS spectrometer in transmission geometry at ET-RR-1 reactor

    International Nuclear Information System (INIS)

    Adib, M.

    1999-01-01

    The phased double rotor facility operating at ET-RR-1 reactor (2MW) was rearranged to operate as SANS spectrometer in transmission geometry. The rotors are suspended in magnetic fields and are spinning up to 16,000 rpm producing bursts of polyenergetic neutrons with wavelengths from 0.2 nm to 6.5 nm and beam divergence of 17' on the sample. The review on research activities using the SANS spectrometer and its applications for powder particle size determination and the long wavelength fluctuation of magnetization of the Fe-Ni alloys are discussed. (author)

  3. The optimum operating conditions of the phased double-rotor facility at the ET-RR-1 reactor

    International Nuclear Information System (INIS)

    Naguib, K.; Habib, N.; Wahba, M.; Kilany, M.; Adib, M.

    1997-01-01

    A pulsed neutron polyenergetic thermal beam at ET-RR-1 is produced by a phased double-rotor facility. One of the rotors has two diametrically opposite curved slots, while the second is designed to operate as a rotating collimator. The dimensions of the phased rotating collimator are selected to match the curved slot rotor. The calculated collimator transmissions at different operating conditions are found to be in good agreement with the experimental ones. The optimum operating conditions of the double-rotor facility are deduced. The calculations were carried out using a computer program RCOL. The RCOL was designed in FORTRAN-77 to operate on PCs. (author)

  4. Research on the Solid State Fermentation of Jerusalem Artichoke Pomace for Producing R,R-2,3-Butanediol by Paenibacillus polymyxa ZJ-9.

    Science.gov (United States)

    Cao, Can; Zhang, Li; Gao, Jian; Xu, Hong; Xue, Feng; Huang, Weiwei; Li, Yan

    2017-06-01

    R,R-2,3-butanediol (R,R-2,3-BD) was produced by Paenibacillus polymyxa ZJ-9, which was capable of utilizing inulin without previous hydrolysis. The Jerusalem artichoke pomace (JAP) derived from the conversion of Jerusalem artichoke powder into inulin extract, which was usually used for biorefinery by submerged fermentation (SMF), was utilized in solid state fermentation (SSF) to produce R,R-2,3-BD. In this study, the fermentation parameters of SSF were optimized and determined in flasks. A novel bioreactor was designed and assembled for the laboratory scale-up of SSF, with a maximum yield of R,R-2,3-BD (67.90 g/kg (JAP)). This result is a 36.3% improvement compared with the flasks. Based on the same bath of Jerusalem artichoke powder, the total output of R,R-2,3-BD increased by 38.8% for the SSF of JAP combined with the SMF of inulin extraction. Overall, the utilization of JAP for R,R-2,3-BD production was beneficial to the comprehensive utilization of Jerusalem artichoke tuber.

  5. Degradation efficiency and mechanism of azo dye RR2 by a novel ozone aerated internal micro-electrolysis filter.

    Science.gov (United States)

    Zhang, Xian-Bing; Dong, Wen-Yi; Sun, Fei-Yun; Yang, Wei; Dong, Jiao

    2014-07-15

    A newly designed ozone aerated internal micro-electrolysis filter (OIEF) was developed to investigate its degradation efficiencies and correlated reaction mechanisms of RR2 dye. Complete decolorization and 82% TOC removal efficiency were stably achieved in OIEF process. Based on the comprehensive experimental results, an empirical equation was proposed to illustrate the effects of initial dye concentration and ozone dosage rate on color removal. The results indicated that OIEF process could be operated at wide pH range without significant treatment efficiencies change, while the optimum pH for RR2 dye degradation was 9.0. There were 15, 8 and 6 kinds of identified intermediates during ozonation, IE and OIEF treatment processes, respectively. Less identified intermediates and their lower concentrations in OIEF may attribute to its rather excellent mineralization performance. It was found that ozonation, Fe(2+)/Fe(3+) catalyzed ozonation, the redox reactions of electro-reduction and electro-oxidation are the most important mechanisms in OIEF process. The catalytic effect of Fe(2+)/Fe(3+) would induce mutual conversion between dissolved Fe(2+) and Fe(3+), and then decrease the dissolution rate of ZVI. The excellent treatment performance proved that the OIEF process is one promising technology applied for reactive azo dyes and other refractory wastewater treatment. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. The period-luminosity and period-radius relations of Type II and anomalous Cepheids in the Large and Small Magellanic Clouds

    Science.gov (United States)

    Groenewegen, M. A. T.; Jurkovic, M. I.

    2017-07-01

    Context. Type II Cepheids (T2Cs) and anomalous Cepheids (ACs) are pulsating stars that follow separate period-luminosity relations. Aims: We study the period-luminosity (PL) and period-radius (PR) relations for T2Cs and ACs in the Magellanic Clouds. Methods: In an accompanying paper we determined the luminosities and effective temperatures for the 335 T2Cs and ACs in the LMC and SMC discovered in the OGLE-III survey, by constructing the spectral energy distribution (SED) and fitting this with model atmospheres and a dust radiative transfer model (in the case of dust excess). Building on these results we studied the PL and PR relations of these sources. Using existing pulsation models for RR Lyrae and classical Cepheids we derive the period-luminosity-mass-temperature-metallicity relations and then estimate the pulsation mass. Results: The PL relation for the T2Cs does not appear to depend on metallicity and is Mbol = + 0.12-1.78log P (for P R = 0.846 + 0.521log P. Relations for fundamental and first overtone LMC ACs are also presented. The pulsation masses from the RR Lyrae and classical Cepheid pulsation models agree well for the short period T2Cs, the BL Her subtype, and ACs, and are consistent with estimates in the literature, I.e. MBLH 0.49M⊙ and MAC 1.3M⊙, respectively. The masses of the W Vir appear similar to the BL Her. The situation for the pWVir and RV Tau stars is less clear. For many RV Tau the masses are in conflict with the standard picture of (single-star) post-AGB evolution, where the masses are either too large (≳1 M⊙) or too small (≲0.4 M⊙). Full Table 3 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/604/A29

  7. Poincaré plot analysis of autocorrelation function of RR intervals in patients with acute myocardial infarction.

    Science.gov (United States)

    Chuang, Shin-Shin; Wu, Kung-Tai; Lin, Chen-Yang; Lee, Steven; Chen, Gau-Yang; Kuo, Cheng-Deng

    2014-08-01

    The Poincaré plot of RR intervals (RRI) is obtained by plotting RRIn+1 against RRIn. The Pearson correlation coefficient (ρRRI), slope (SRRI), Y-intercept (YRRI), standard deviation of instantaneous beat-to-beat RRI variability (SD1RR), and standard deviation of continuous long-term RRI variability (SD2RR) can be defined to characterize the plot. Similarly, the Poincaré plot of autocorrelation function (ACF) of RRI can be obtained by plotting ACFk+1 against ACFk. The corresponding Pearson correlation coefficient (ρACF), slope (SACF), Y-intercept (YACF), SD1ACF, and SD2ACF can be defined similarly to characterize the plot. By comparing the indices of Poincaré plots of RRI and ACF between patients with acute myocardial infarction (AMI) and patients with patent coronary artery (PCA), we found that the ρACF and SACF were significantly larger, whereas the RMSSDACF/SDACF and SD1ACF/SD2ACF were significantly smaller in AMI patients. The ρACF and SACF correlated significantly and negatively with normalized high-frequency power (nHFP), and significantly and positively with normalized very low-frequency power (nVLFP) of heart rate variability in both groups of patients. On the contrary, the RMSSDACF/SDACF and SD1ACF/SD2ACF correlated significantly and positively with nHFP, and significantly and negatively with nVLFP and low-/high-frequency power ratio (LHR) in both groups of patients. We concluded that the ρACF, SACF, RMSSDACF/SDACF, and SD1ACF/SD2ACF, among many other indices of ACF Poincaré plot, can be used to differentiate between patients with AMI and patients with PCA, and that the increase in ρACF and SACF and the decrease in RMSSDACF/SDACF and SD1ACF/SD2ACF suggest an increased sympathetic and decreased vagal modulations in both groups of patients.

  8. Interval ridge regression (iRR) as a fast and robust method for quantitative prediction and variable selection applied to edible oil adulteration.

    Science.gov (United States)

    Jović, Ozren; Smrečki, Neven; Popović, Zora

    2016-04-01

    A novel quantitative prediction and variable selection method called interval ridge regression (iRR) is studied in this work. The method is performed on six data sets of FTIR, two data sets of UV-vis and one data set of DSC. The obtained results show that models built with ridge regression on optimal variables selected with iRR significantly outperfom models built with ridge regression on all variables in both calibration (6 out of 9 cases) and validation (2 out of 9 cases). In this study, iRR is also compared with interval partial least squares regression (iPLS). iRR outperfomed iPLS in validation (insignificantly in 6 out of 9 cases and significantly in one out of 9 cases for poil, a well known health beneficial nutrient, is studied in this work by mixing it with cheap and widely used oils such as soybean (So) oil, rapeseed (R) oil and sunflower (Su) oil. Binary mixture sets of hempseed oil with these three oils (HSo, HR and HSu) and a ternary mixture set of H oil, R oil and Su oil (HRSu) were considered. The obtained accuracy indicates that using iRR on FTIR and UV-vis data, each particular oil can be very successfully quantified (in all 8 cases RMSEPoil (R(2)>0.99). Copyright © 2015 Elsevier B.V. All rights reserved.

  9. [The influence of age and illness duration on cognitive impairment in aging patients with relapsing-remitting multiple sclerosis (RR-MS)].

    Science.gov (United States)

    Leclercq, Eugénie; Cabaret, Maryline; Guilbert, Alma; Jougleux, Caroline; Vermersch, Patrick; Moroni, Christine

    2014-09-01

    The aim of this study was to dissociate age and duration of illness effects on cognitive impairment of patients with relapsing-remitting multiple sclerosis. Cognitive impairment among patients with multiple sclerosis (MS) is well known. However, few studies were devoted to assess the respective role of disease duration and age on cognitive functions in MS patients. Therefore, two studies were carried out on relapsing-remitting MS (RR-MS) patients using some tests of the BCcogSEP--a French test battery evaluating cognitive functions in MS. The cognitive deficits of RR-MS patients aged 50 years and over and whose symptoms had been present for more than 20 years were more severe than those of MS patients with a shorter illness duration (less than 10 years) or matched-age control participants. The more impaired cognitive functions were information-processing speed, episodic memory, verbal fluency and attention. On the other hand, cognitive performances of young RR-MS patients were similar to those of older RR-MS patients when all patients had the same illness duration (8 years in this study). Older patients even achieved better performance than younger ones on verbal fluency. This can be partly explained by the theory of cognitive reserve, as reported in previous cognitive aging studies. In RR-MS patients, the influence of illness duration seems to be a predominant factor in the development of cognitive impairment.

  10. Microstructural characterisation and constitutive behaviour of alloy RR1000 under fatigue and creep-fatigue loading conditions

    International Nuclear Information System (INIS)

    Stoecker, C.; Zimmermann, M.; Christ, H.-J.; Zhan, Z.-L.; Cornet, C.; Zhao, L.G.; Hardy, M.C.; Tong, J.

    2009-01-01

    Mechanical behaviour of a nickel-based superalloy, RR1000, has been investigated at 650 deg. C under cyclic and dwell loading conditions. The microstructural characteristics of the alloy have been studied using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and the distribution patterns of the dislocations and slip planes have been compared between samples tested under fatigue and creep-fatigue loading conditions. Constitutive behaviour of the alloy was described by a unified constitutive model, where both cyclic plastic and viscoplastic strains were represented by one inelastic strain. The results show that the precipitation state is very stable at 650 deg. C and only minor differences exist in the dislocation arrangements formed under pure fatigue and combined creep and fatigue conditions. Hence, a unified constitutive model seems to be justified in describing and predicting the constitutive behaviour in both cases.

  11. Stability of cyanotoxins, microcystin-LR, microcystin-RR and nodularin in seawater and BG-11 medium of different salinity

    Directory of Open Access Journals (Sweden)

    Hanna Mazur

    2001-09-01

    Full Text Available Microcystins and nodularin are potent hepatotoxins produced by fresh and seawater cyanobacteria. The persistence of three hepatotoxins - microcystin-LR, microcystin-RR and nodularin - was investigated in sterile BG-11 medium of different salinity and in water collected from the Gulf of Gdansk. After 21 days of incubation at 17 ± 1oC and constant illumination of about 40 µmol photon m-2 s-1 the concentration of toxins decreased by about 30-37%. No significant changes in toxin concentration in the BG-11 media of different salinity were observed. When toxins were incubated in non-sterile seawater, their concentrations decreased markedly. It is likely that some strains of bacteria are responsible for the breakdown of the toxins. Nodularin turned out to be more resistant to biodegradation than the two microcystins. The influence of certain components of cyanobacteria cells on the accelerated rate of toxin degradation was also considered.

  12. On new bulk singularity structures, RR couplings in the asymmetric picture and their all order α{sup '} corrections

    Energy Technology Data Exchange (ETDEWEB)

    Hatefi, Ehsan [Queen Mary University of London, Centre for Research in String Theory, School of Physics and Astronomy, London (United Kingdom); TU Wien, Institute for Theoretical Physics, Vienna (Austria)

    2017-08-15

    We have analyzed in detail four and five point functions of the string theory amplitudes, including a closed string Ramond-Ramond (RR) in an asymmetric picture and either two or three transverse scalar fields in both IIA and IIB. The complete forms of these S-matrices are derived and these asymmetric S-matrices are also compared with their own symmetric results. This leads us to explore two different kinds of bulk singularity structures as well as various new couplings in the asymmetric picture of the amplitude in type II string theory. All order α{sup '} higher derivative corrections to these new couplings have been discovered as well. Several remarks for these two new bulk singularity structures and for contact interactions of the S-matrix have also been made. (orig.)

  13. Inverse correlation between the standard deviation of R-R intervals in supine position and the simplified menopausal index in women with climacteric symptoms.

    Science.gov (United States)

    Yanagihara, Nobuyuki; Seki, Meikan; Nakano, Masahiro; Hachisuga, Toru; Goto, Yukio

    2014-06-01

    Disturbance of autonomic nervous activity has been thought to play a role in the climacteric symptoms of postmenopausal women. This study was therefore designed to investigate the relationship between autonomic nervous activity and climacteric symptoms in postmenopausal Japanese women. The autonomic nervous activity of 40 Japanese women with climacteric symptoms and 40 Japanese women without climacteric symptoms was measured by power spectral analysis of heart rate variability using a standard hexagonal radar chart. The scores for climacteric symptoms were determined using the simplified menopausal index. Sympathetic excitability and irritability, as well as the standard deviation of mean R-R intervals in supine position, were significantly (P standard deviation of mean R-R intervals in supine position and the simplified menopausal index score. The lack of control for potential confounding variables was a limitation of this study. In climacteric women, the standard deviation of mean R-R intervals in supine position is negatively correlated with the simplified menopausal index score.

  14. Relationship among RR interval, optimal reconstruction phase, temporal resolution, and image quality of end-systolic reconstruction of coronary CT angiography in patients with high heart rates. In search of the optimal acquisition protocol

    International Nuclear Information System (INIS)

    Sano, Tomonari; Matsutani, Hideyuki; Kondo, Takeshi; Fujimoto, Shinichiro; Sekine, Takako; Arai, Takehiro; Morita, Hitomi; Takase, Shinichi

    2011-01-01

    The purpose of this study is to elucidate the relationship among RR interval (RR), the optimal reconstruction phase, and adequate temporal resolution (TR) to obtain coronary CT angiography images of acceptable quality using 64-multi detector-row CT (MDCT) (Aquilion 64) of end-systolic reconstruction in 407 patients with high heart rates. Image quality was classified into 3 groups [rank A (excellent): 161, rank B (acceptable): 207, and rank C (unacceptable): 39 patients]. The optimal absolute phase (OAP) significantly correlated with RR [OAP (ms)=119-0.286 RR (ms), r=0.832, p<0.0001], and the optimal relative phase (ORP) also significantly correlated with RR [ORP (%)=62-0.023 RR (ms), r=0.656, p<0.0001], and the correlation coefficient of OAP was significantly (p<0.0001) higher than that of ORP. The OAP range (±2 standard deviation (SD)) in which it is highly possible to get a static image was from [119-0.286 RR (ms)-46] to [119-0.286 RR (ms)+46]. The TR was significantly different among ranks A (97±22 ms), B (111±31 ms) and C (135±34 ms). The TR significantly correlated with RR in ranks A (TR=-16+0.149 RR, r=0.767, p<0.0001), B (TR=-15+0.166 RR, r=0.646, p<0.0001), and C (TR=52+0.117 RR, r=0.425, p=0.0069). Rank C was distinguished from ranks A or B by linear discriminate analysis (TR=-46+0.21 RR), and the discriminate rate was 82.6%. In conclusion, both the OAP and adequate TR depend on RR, and the OAP range (±2 SD) can be calculated using the formula [119-0.286 RR (ms)-46] to [119-0.286 RR (ms) +46], and an adequate TR value would be less than (-46+0.21 RR). (author)

  15. Variations in weed population densities, rate of change and community diversity in RR-soybeans and RR-maize strip crops under two herbicide strategies Ação de herbicidas sobre as plantas daninhas na soja e milho RR em plantio consorciado

    Directory of Open Access Journals (Sweden)

    E.S. Leguizamón

    2012-12-01

    Full Text Available Concerns about the sustainability of large-scale, direct-drilled RR-soybeans (Glycine max, and RR-maize (Zea mays under monoculture in central Argentina are growing steadily. An experiment was conducted during three consecutive years to determine the effects of crops and systems (monocultures and strips and herbicide strategy on weed density, population rate of change (l, b community diversity (H´, crop yields and Land Equivalent Ratio (LER. Not only crops but also crop systems differentially influenced weed densities along their growth and development. For crop harvests, weed densities increased in both maize crop systems as compared to in the one for soybeans, but the lowest increase occurred in soybean strips. Differences were leveled by both herbicide strategies, which achieved 73% efficacy during the critical periods in both crops. l of annual monocotyledonous increased, thus shifting the weed community composition. Species richness and H´ were not affected by crop systems, but both herbicide strategies, particularly POST, either in soybeans in monoculture or in maize strips, significantly enhanced H´. Crop yields significantly increased in the maize-strip system with POST (Year 1 or PRE (Years 2 and 3 strategies, thus increasing LER above 1. Herbicide Environmental Load treatments fall within very low or low field use rating.A preocupação com a sustentabilidade do plantio direto da monocultura e do consórcio de soja e milho RR plantados em grande escala na região central da Argentina cresce continuamente. Durante três anos consecutivos, foram determinados os efeitos das culturas de soja e de milho RR, dos sistemas de plantio (monoculturas e consorciado, e a ação de herbicidas sobre a densidade de plantas daninhas, a taxa de mudança da população, a diversidade da comunidade, as safras e a razão de área equivalente. Não apenas as culturas, mas também os sistemas de plantio, influenciaram as densidades de plantas daninhas ao

  16. The history and development of nonlinear stellar pulsation codes

    International Nuclear Information System (INIS)

    Davis, C.G.

    1987-01-01

    This review is limited to the history and development of nonlinear stellar pulsation codes and methods. The narrative includes examples of practical interest in the application of these numerical methods to problems in stellar pulsation such as Cepheid mass discrepancy, the delineation of the RR Lyrae instability strip, and the question of the development of double-mode pulsation as observed in Cepheids, RR Lyrae and other variable stars. 15 refs

  17. R-matrix and RR-matrix calculations for cross sections for photoionization of outermost subshell in nobile gas atoms

    International Nuclear Information System (INIS)

    Tiwary, S.N.

    2000-02-01

    Photon impact integral ionization cross section (σ) as well as photoelectron asymmetry parameter (β) for the reactions hν+Ne(1s 2 2s 2 2p 6 ) → Ne + (1s 2 2s 2 2p 5 ) + e - , hν+Ar(1s 2 2s 2 2p 6 3s 2 3p 6 ) → Ar + (1s 2 2s 2 2p 6 3s 2 3p 5 ) + e - , hν+Kr(1s 2 2s 2 2p 6 3s 2 3p 6 3d 10 4s 2 4p 6 ) → Kr + (1s 2 2s 2 2p 6 3s 2 3p 6 3d 10 4s 2 4p 5 ) + e - and hν+Xe(1s 2 2s 2 2p 6 3s 2 3p 6 3d 10 4s 2 4p 6 4d 10 5s 2 5p 6 ) → Xe + (1s 2 2s 2 2p 6 3s 2 3p 6 3d 10 4s 2 4p 6 4d 10 5s 2 5p 5 ) + e - have been calculated in the L-S and j-j coupling schemes using Hartree-Fock (HF) wavefunctions within the reliable non-relativistic R-matrix as well as relativistic R-matrix (RR-matrix) methods in both the length and velocity gauges in the energy range of experimental data available. Comparison is made with all available experimental data as well as other theoretical results. Our present theoretical investigation clearly demonstrates that there is a good agreement between our present R-matrix results and RR-matrix results as well as with other results in the case of neon which reflects that the correlation and relativity are not important in this case, in the energy range of present consideration. Whereas in the case of xenon (Z=54), the independent-particle approximation completely breaks down, i.e., HF cross sections are both qualitatively as well as quantitatively incorrect in the entire energy range which exhibit that the multielectron correlation as well as relativity are both important but interchannel interactions are more important than the intrachannel interaction and relativity for obtaining high precision results. (author)

  18. 75 FR 33738 - Airworthiness Directives; Rolls-Royce plc (RR) RB211-524 Series and RB211 Trent 500, 700, and 800...

    Science.gov (United States)

    2010-06-15

    ...-0562; Directorate Identifier 2009-NE-29-AD] RIN 2120-AA64 Airworthiness Directives; Rolls-Royce plc (RR...-2251. Contact Rolls-Royce plc, P.O. Box 31, Derby, DE24 8BJ, United Kingdom; phone: 011 44 1332 242424... amend this proposed AD based on those comments. We will post all comments we receive, without change, to...

  19. 75 FR 27964 - Airworthiness Directives; Rolls-Royce plc (RR) RB211-22B and RB211-524 Series Turbofan Engines

    Science.gov (United States)

    2010-05-19

    ...-1157; Directorate Identifier 2009-NE-26-AD] RIN 2120-AA64 Airworthiness Directives; Rolls-Royce plc (RR... p.m., Monday through Friday, except Federal holidays. Fax: (202) 493-2251. Contact Rolls-Royce plc... received by the closing date and may amend this proposed AD based on those comments. We will post all...

  20. 75 FR 51654 - Airworthiness Directives; Rolls-Royce plc (RR) RB211-22B and RB211-524 Series Turbofan Engines

    Science.gov (United States)

    2010-08-23

    ... Airworthiness Directives; Rolls-Royce plc (RR) RB211-22B and RB211-524 Series Turbofan Engines AGENCY: Federal... that air safety and the public interest require adopting the AD as proposed. Costs of Compliance Based... labor rate is $85 per work-hour. Required parts will cost about $15,000 per product. Based on these...

  1. Analysis of shot-peening and residual stress relaxation in the nickel-based superalloy RR1000

    International Nuclear Information System (INIS)

    Foss, B.J.; Gray, S.; Hardy, M.C.; Stekovic, S.; McPhail, D.S.; Shollock, B.A.

    2013-01-01

    This work assesses the residual stress relaxation of the nickel-based alloy RR1000 due to thermal exposure and dwell-fatigue loading. A number of different characterization methods, including X-ray residual stress analysis, electron back-scattered diffraction, microhardness testing and focused ion beam secondary electron imaging, contributed to a detailed study of the shot-peened region. Thermal exposure at 700 °C resulted in a large reduction in the residual stresses and work-hardening effects in the alloy, but the subsurface remained in a beneficial compressive state. Oxidizing environments caused recrystallization in the near surface, but did not affect the residual stress-relaxation behaviour. Dwell-fatigue loading caused the residual stresses to return to approximately zero at nearly all depths. This work forms part of an ongoing investigation to determine the effects of shot-peening in this alloy with the motivation to improve the fatigue and oxidation resistance at 700 °C

  2. The recursive combination filter approach of pre-processing for the estimation of standard deviation of RR series.

    Science.gov (United States)

    Mishra, Alok; Swati, D

    2015-09-01

    Variation in the interval between the R-R peaks of the electrocardiogram represents the modulation of the cardiac oscillations by the autonomic nervous system. This variation is contaminated by anomalous signals called ectopic beats, artefacts or noise which mask the true behaviour of heart rate variability. In this paper, we have proposed a combination filter of recursive impulse rejection filter and recursive 20% filter, with recursive application and preference of replacement over removal of abnormal beats to improve the pre-processing of the inter-beat intervals. We have tested this novel recursive combinational method with median method replacement to estimate the standard deviation of normal to normal (SDNN) beat intervals of congestive heart failure (CHF) and normal sinus rhythm subjects. This work discusses the improvement in pre-processing over single use of impulse rejection filter and removal of abnormal beats for heart rate variability for the estimation of SDNN and Poncaré plot descriptors (SD1, SD2, and SD1/SD2) in detail. We have found the 22 ms value of SDNN and 36 ms value of SD2 descriptor of Poincaré plot as clinical indicators in discriminating the normal cases from CHF cases. The pre-processing is also useful in calculation of Lyapunov exponent which is a nonlinear index as Lyapunov exponents calculated after proposed pre-processing modified in a way that it start following the notion of less complex behaviour of diseased states.

  3. Solid-solution stability and preferential site-occupancy in (R-R')2Fe14B compounds

    Science.gov (United States)

    Colin, C. V.; Ito, M.; Yano, M.; Dempsey, N. M.; Suard, E.; Givord, D.

    2016-06-01

    The rare-earth (R) uniaxial anisotropy of R2Fe14B compounds with magnetic R atoms (e.g., Nd or Pr) is at the origin of the exceptional hard magnetic properties achieved in magnets based on these compounds. The uniaxial anisotropy found in Ce2Fe14B is attributed mainly to the magnetism of Fe. Ce is the most abundant R element and there has been much recent effort to fabricate magnets in which Ce is partially substituted for Nd. In the present neutron study of (R1-xCex)2Fe14B (R = La or Nd), Ce is found to enter the R2Fe14B phase over the entire composition range. The crystallographic parameters decrease with increasing Ce content and the Ce atoms preferentially occupy the smaller 4f sites. It is concluded that Ce in these (RR')2Fe14B compounds essentially maintains the intermediate valence character found in Ce2Fe14B. It is proposed that, in this intermediate valence state, Ce weakly contributes to uniaxial anisotropy, thus making a link with the fact that significant coercivity is preserved in Ce-substituted NdFeB magnets.

  4. Chemical Composition of RR Lyn – an Eclipsing Binary System with Am and λ Boo Type Components

    Directory of Open Access Journals (Sweden)

    Yeuncheol Jeong

    2017-06-01

    Full Text Available High-resolution spectroscopic observations of the eclipsing binary system RR Lyn were made using the 1.8 m telescope at the Bohuynsan Optical Astronomical Observatory in Korea. The spectral resolving power was R = 82,000, with a signal to noise ratio of S/N > 150. We found the effective temperatures and surface gravities of the primary and secondary components to be equal to Teff = 7,920 & 7,210 K and log(g = 3.80 & 4.16, respectively. The abundances of 34 and 17 different chemical elements were found in the atmospheric components. Correlations between the derived abundances with condensation temperatures and the second ionization potentials of these elements are discussed. The primary component is a typical metallic line star with the abundances of light and iron group elements close to solar values, while elements with atomic numbers Z > 30 are overabundant by 0.5–1.5 dex with respect to solar values. The secondary component is a λ Boo type star. In this type of stars, CNO abundances are close to solar values, while the abundance pattern shows a negative correlation with condensation temperatures.

  5. Increasing sensitivity in the measurement of heart rate variability: the method of non-stationary RR time-frequency analysis.

    Science.gov (United States)

    Melkonian, D; Korner, A; Meares, R; Bahramali, H

    2012-10-01

    A novel method of the time-frequency analysis of non-stationary heart rate variability (HRV) is developed which introduces the fragmentary spectrum as a measure that brings together the frequency content, timing and duration of HRV segments. The fragmentary spectrum is calculated by the similar basis function algorithm. This numerical tool of the time to frequency and frequency to time Fourier transformations accepts both uniform and non-uniform sampling intervals, and is applicable to signal segments of arbitrary length. Once the fragmentary spectrum is calculated, the inverse transform recovers the original signal and reveals accuracy of spectral estimates. Numerical experiments show that discontinuities at the boundaries of the succession of inter-beat intervals can cause unacceptable distortions of the spectral estimates. We have developed a measure that we call the "RR deltagram" as a form of the HRV data that minimises spectral errors. The analysis of the experimental HRV data from real-life and controlled breathing conditions suggests transient oscillatory components as functionally meaningful elements of highly complex and irregular patterns of HRV. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  6. Quality assessment of fruit pulps industrialized and commercialized in the city of Boa Vista – RR = Avaliação da qualidade de polpas de frutos industrializadas e comercializadas no município de Boa Vista – RR

    Directory of Open Access Journals (Sweden)

    Cássia Rejane Nascimento

    2012-12-01

    Full Text Available This work aimed to study the quality of frozen pulp, manufactured and marketed in Boa Vista - RR, through physico-chemical analysis. It were selected six Agroindustries that produce and market pulp in establishments located in Fair Passarão, supermarkets and home of juices, identified by the letters A, B, C, D, E and F. The variables studied were: soluble solids, titratable acidity and vitamin C, of the flavors: acerola, caja, cupuaçu, guava, soursop and passion fruit. The experiment was conducted in completely randomized design, being analyzed six brands of fruits pulps and six different fruits, with three replicates. The observed results demonstrate that none of the companies processing fruit pulp detail their identification inaccordance with the legislation. In the variables studied, only the cupuaçu pulp brands C and D and soursop brands B, C, D and E were in accordance with the technical regulation for fixing the identity and quality standard. Considering the variables in question, it was found that variations in the levels encountered and not adequacy of these standards could be minimized by the standardization of raw materials and processes used. =Objetivou-se com o presente trabalho estudar a qualidade de polpas congeladas, fabricadas e comercializadas no município de Boa Vista – RR, por meio de análises físico-químicas. Foram selecionadas seis Agroindústrias que produzem polpa e comercializam em estabelecimentos próprios localizados na Feira do Passarão, supermercados e casa de sucos, sendo identificadas pelas letras A, B, C, D, E e F. As variáveis estudadas foram: sólidos solúveis, acidez titulável e vitamina C, dos sabores: acerola, cajá, cupuaçu, goiaba, graviola e maracujá. O experimento foi conduzido em delineamento inteiramentecasualizado, sendo analisadas seis marcas de polpas e seis frutos diferentes, com três repetições. Os resultados observadosdemonstram que nenhuma das empresas de processamento de polpa

  7. Qualidade fisiológica de sementes de soja convencional e transgênica RR produzidas sob aplicação foliar de manganês

    Directory of Open Access Journals (Sweden)

    Everson Reis Carvalho

    2014-09-01

    Full Text Available Sementes de soja com alta qualidade fisiológica são essenciais à obtenção de produtividade elevada e um dos fatores que afetam a produção de sementes é a nutrição mineral. O objetivo neste trabalho foi avaliar o efeito da aplicação foliar de manganês, em diferentes doses e estádios de aplicação, na qualidade fisiológica de sementes de soja, em cultivares convencionais e em suas derivadas transgênicas RR, com distintos teores de lignina do tegumento. O ensaio foi conduzido em blocos casualizados, com três repetições e esquema fatorial 4 x 4 x 2, sendo quatro cultivares de soja, duas convencionais e suas derivadas transgênicas RR (BRS Celeste e BRS Baliza RR; BRSGO Jataí e BRS Silvânia RR, quatro doses de Mn via foliar (0; 200; 400 e 600 g Mn ha-1 e dois estádios de aplicação (R1 e R3. A qualidade fisiológica das sementes foi estimada, antes e após seis meses de armazenamento, por meio dos testes: Germinação, Envelhecimento acelerado, Emergência de plântulas, Condutividade elétrica e Tetrazólio (Viabilidade, vigor e danos mecânicos. Realizou-se também a quantificação de lignina no tegumento das sementes. A aplicação foliar de Mn proporciona incrementos na qualidade fisiológica nas sementes de soja produzidas. Sementes das cultivares de soja Celeste e Baliza RR apresentam melhor qualidade fisiológica quando comparadas às de Jataí e Silvânia RR. Sementes de cultivares de soja com maior teor de lignina no tegumento não apresentam necessariamente melhor qualidade fisiológica, sendo a qualidade das sementes relacionada a outros fatores intrínsecos ao genótipo.

  8. SPET imaging of central muscarinic receptors with (R,R)[123I]-I-QNB: methodological considerations

    International Nuclear Information System (INIS)

    Norbury, R.; Travis, M.J.; Erlandsson, K.; Waddington, W.; Owens, J.; Ell, P.J.; Murphy, D.G.

    2004-01-01

    Investigations on the effect of normal healthy ageing on the muscarinic system have shown conflicting results. Also, in vivo determination of muscarinic receptor binding has been hampered by a lack of subtype selective ligands and differences in methods used for quantification of receptor densities. Recent in vitro and in vivo work with the muscarinic antagonist (R,R)-I-QNB indicates this ligand has selectivity for m 1 and m 4 muscarinic receptor subtypes. Therefore, we used (R,R)[ 123 I]-I-QNB and single photon emission tomography to study brain m 1 and m 4 muscarinic receptors in 25 healthy female subjects (11 younger subjects, age range 26-32 years and 14 older subjects, age range 57-82 years). Our aims were to ascertain the viability of tracer administration and imaging within the same day, and to evaluate whether normalization to whole brain, compared to normalization to cerebellum, could alter the clinical interpretation of results. Images were analyzed using the simplified reference tissue model and by two ratio methods: normalization to whole brain and normalization to cerebellum. Significant correlations were observed between kinetic analysis and normalization to cerebellum, but not to whole brain. Both the kinetic analysis and normalization to cerebellum showed age-related reductions in muscarinic binding in frontal, orbitofrontal, and parietal regions. Normalization to whole brain, however, failed to detect age-related changes in any region. Here we show that, for this radiotracer, normalizing to a region of negligible specific binding (cerebellum) significantly improves sensitivity when compared to global normalization

  9. Higher dimensional homogeneous cosmology in Lyra geometry

    Indian Academy of Sciences (India)

    1Department of Mathematics, Jadavpur University, Kolkata 700 032, India. 2Khodar ... 1. Introduction. The idea of higher dimensional theory was originated in super string and super gravity .... Equation (7) can easily be integrated to obtain.

  10. Production of R,R-2,3-butanediol of ultra-high optical purity from Paenibacillus polymyxa ZJ-9 using homologous recombination.

    Science.gov (United States)

    Zhang, Li; Cao, Can; Jiang, Ruifan; Xu, Hong; Xue, Feng; Huang, Weiwei; Ni, Hao; Gao, Jian

    2018-08-01

    The present study describes the use of metabolic engineering to achieve the production of R,R-2,3-butanediol (R,R-2,3-BD) of ultra-high optical purity (>99.99%). To this end, the diacetyl reductase (DAR) gene (dud A) of Paenibacillus polymyxa ZJ-9 was knocked out via homologous recombination between the genome and the previously constructed targeting vector pRN5101-L'C in a process based on homologous single-crossover. PCR verification confirmed the successful isolation of the dud A gene disruption mutant P. polymyxa ZJ-9-△dud A. Moreover, fermentation results indicated that the optical purity of R,R-2,3-BD increased from about 98% to over 99.99%, with a titer of 21.62 g/L in Erlenmeyer flasks. The latter was further increased to 25.88 g/L by fed-batch fermentation in a 5-L bioreactor. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. Effect of oscillatory breathing on the variability of the RR Intervals and its prognostic importance in individuals with left ventricular global systolic dysfunction

    Directory of Open Access Journals (Sweden)

    Barbosa Paulo Roberto Benchimol

    2003-01-01

    Full Text Available OBJECTIVE: To assess the effect of the oscillatory breathing on the variability of RR intervals (VRR and on prognostic significance after one year follow-up in subjects with left ventricular global systolic dysfunction. METHODS: We studied 76 subjects, whose age ranged from 40 to 80 years, paired for age and gender, divided into two groups: group I - 34 healthy subjects; group II - 42 subjects with left ventricular global systolic dysfunction (ejection fraction < 0.40. The ECG signals were acquired during 600s in supine position, and analyzed the variation of the thoracic amplitude and the VRR. Clinical and V-RR variables were applied into a logistic multivariate model to foretell survival after one year follow-up. RESULTS: Oscillatory breathing was detected in 35.7% of subjects in vigil state of group II, with a concentration of the spectral power in the very low frequency band, and was independent of the presence of diabetes, functional class, ejection fraction, cause of ventricular dysfunction and survival after one year follow-up. In the logistic regression model, ejection fraction was the only independent variable to predict survival. CONCLUSION: 1 Oscillatory breathing pattern is frequent during wakefulness in the left ventricular global systolic dysfunction and concentrates spectral power in the very low band of V-RR; 2 it does not relate to severity and cause of left ventricular dysfunction; 3 ejection fraction is the only independent predictive variable for survival in this group of subjects.

  12. On The Possible Leakage of ET-RR1 Liquid Waste Tank: Hydrological and Migration Modes Studies

    Directory of Open Access Journals (Sweden)

    N. S. Mahmoud

    2005-01-01

    Full Text Available The first Egyptian (ET-RR1 research reactor has been in operation since 1961 at the Egyptian Atomic Energy Authority (EAEA Inshas site. Therefore, at present, it faces a serious problem due to aging equipment, especially those directly in contact with the environment such as the underground settling tanks of nuclear and radioactive waste. The possible leakage of radionuclides from these aging tanks and their migration to the aquifer was studied using instantaneous release.This study was done based on the geological and hydrological characteristics of the site, which were obtained from the hydrogeological data of 25 wells previously drilled at the site of the reactor[1]. These data were used to calculate the trend of water levels, hydraulic gradient, and formulation of water table maps from 1993–2002. This information was utilized to determine water velocity in the unsaturated zone.Radionuclides released from the settling tank to the aquifer were screened according to the radionuclides that have high migration ability and high activity. The amount of fission and activation products of the burned fuels that contaminated the water content of the reactor pool were considered as 10% of the original spent fuel. The radionuclides considered in this case were H-3, Sr-90, Zr-93, Tc-99, Cd-113, Cs-135, Cs-137, Sm-151, Pu-238, Pu-240, Pu-241, and Am-241.The instantaneous release was analyzed by theoretical calculations, taking into consideration the migration mechanism of the various radionuclides through the soil space between the tank bottom and the aquifer. The migration mechanism through the unsaturated zone was considered depending on soil type, thickness of the unsaturated zone, water velocity, and other factors that are specific for each radionuclide, namely retardation factor, which is the function of the specific distribution coefficient of each radionuclide. This was considered collectively as delay time. Meanwhile, the mechanism of

  13. The Globular Cluster NGC 6402 (M14). II. Variable Stars

    Science.gov (United States)

    Contreras Peña, C.; Catelan, M.; Grundahl, F.; Stephens, A. W.; Smith, H. A.

    2018-03-01

    We present time-series BVI photometry for the Galactic globular cluster NGC 6402 (M14). The data consist of ∼137 images per filter, obtained using the 0.9 and 1.0 m SMARTS telescopes at the Cerro Tololo Inter-American Observatory. The images were obtained during two observing runs in 2006–2007. The image-subtraction package ISIS, along with DAOPHOT II/ALLFRAME, was used to perform crowded-field photometry and search for variable stars. We identified 130 variables, eight of which are new discoveries. The variable star population is comprised of 56 ab-type RR Lyrae stars, 54 c-type RR Lyrae, 6 type II Cepheids, 1 W UMa star, 1 detached eclipsing binary, and 12 long-period variables. We provide Fourier decomposition parameters for the RR Lyrae, and discuss the physical parameters and photometric metallicity derived therefrom. The M14 distance modulus is also discussed, based on different approaches for the calibration of the absolute magnitudes of RR Lyrae stars. The possible presence of second-overtone RR Lyrae in M14 is critically addressed, with our results arguing against this possibility. By considering all of the RR Lyrae stars as members of the cluster, we derive =0.589 {{d}}{{a}}{{y}}{{s}}. This, together with the position of the RR Lyrae stars of both Bailey types in the period–amplitude diagram, suggests an Oosterhoff-intermediate classification for the cluster. Such an intermediate Oosterhoff type is much more commonly found in nearby extragalactic systems, and we critically discuss several other possible indications that may point to an extragalactic origin for this cluster. Based on observations obtained with the 0.9 m and 1 m telescopes at the Cerro Tololo Inter-American Observatory, Chile, operated by the SMARTS consortium.

  14. Critical effects of alkyl chain length on fibril structures in benzene-trans(RR)- or (SS)-N,N'-alkanoyl-1,2-diaminocyclohexane gels.

    Science.gov (United States)

    Sato, Hisako; Nakae, Takahiro; Morimoto, Kazuya; Tamura, Kenji

    2012-02-28

    Vibrational circular dichroism (VCD) spectra were recorded on benzene-d(6) gels formed by chiral low molecular mass gelators (LMGs), trans(RR)- or trans(SS)-N,N'-alkanoyl-1,2-diaminocyclohexane (denoted by RR-C(n) or SS-C(n), respectively; n = the number of carbon atoms in an introduced alkanoyl group). Attention was focused on the effects of alkyl chain length on the structures of the gels. When n was changed from 6 to 12, the signs of the coupled peaks around 1550 cm(-1) in the VCD spectra, which were assigned to the symmetric and asymmetric C=O stretching vibrations from the higher to lower wavenumber, respectively, critically depended on the alkyl chain length. In the case of RR-C(n), for example, the signs of the couplet were plus and minus for n = 8, 9, 10 and 12, while the signs of the same couplet were reversed for n = 6 and 7. The conformations of LMGs in fibrils were determined by comparing the observed IR and VCD spectra with those calculated for a monomeric molecule. The observed reversal of signs in the C=O couplet was rationalized in terms of the different modes of hydrogen bonding. In the case of C(8), C(9), C(10) and C(12), gelator molecules were stacked with their cyclohexyl rings in parallel, forming double anti-parallel chains of intermolecular hydrogen bonds using two pairs of >NH and >C=O groups. In case of C(6) and C(7), gelator molecules were stacked through a single chain of intermolecular hydrogen bonds using a pair of >NH and >C=O groups. The remaining pair of >NH and >C=O groups formed an intramolecular hydrogen bond.

  15. A survey of HK, HPt, and RR domains and their organization in two-component systems and phosphorelay proteins of organisms with fully sequenced genomes

    Directory of Open Access Journals (Sweden)

    Baldiri Salvado

    2015-08-01

    Full Text Available Two Component Systems and Phosphorelays (TCS/PR are environmental signal transduction cascades in prokaryotes and, less frequently, in eukaryotes. The internal domain organization of proteins and the topology of TCS/PR cascades play an important role in shaping the responses of the circuits. It is thus important to maintain updated censuses of TCS/PR proteins in order to identify the various topologies used by nature and enable a systematic study of the dynamics associated with those topologies. To create such a census, we analyzed the proteomes of 7,609 organisms from all domains of life with fully sequenced and annotated genomes. To begin, we survey each proteome searching for proteins containing domains that are associated with internal signal transmission within TCS/PR: Histidine Kinase (HK, Response Regulator (RR and Histidine Phosphotranfer (HPt domains, and analyze how these domains are arranged in the individual proteins. Then, we find all types of operon organization and calculate how much more likely are proteins that contain TCS/PR domains to be coded by neighboring genes than one would expect from the genome background of each organism. Finally, we analyze if the fusion of domains into single TCS/PR proteins is more frequently observed than one might expect from the background of each proteome. We find 50 alternative ways in which the HK, HPt, and RR domains are observed to organize into single proteins. In prokaryotes, TCS/PR coding genes tend to be clustered in operons. 90% of all proteins identified in this study contain just one of the three domains, while 8% of the remaining proteins combine one copy of an HK, a RR, and/or an HPt domain. In eukaryotes, 25% of all TCS/PR proteins have more than one domain. These results might have implications for how signals are internally transmitted within TCS/PR cascades. These implications could explain the selection of the various designs in alternative circumstances.

  16. Simulation of the gamma dose rate in a loss of pool water accident of the second Egyptian research reactor ET-RR-2

    International Nuclear Information System (INIS)

    Amin, E.; Saleh, H.G.; Ashoub, N.

    2002-01-01

    The second Egyptian research reactor ET-RR-2, is a pool type reactor. A sudden loss of pool water would leave the core region uncovered. The reactor core is surrounded by chimney chambers with water isolated from the pool water. This accident would lead to significant external doses. A model is developed and used to calculate the dose rates for key access-areas and traffic plans from indirect line of sight of the core which have a maximum dose rate. The model developed uses the discrete ordinate method as implemented in the code DOT3.5. (orig.) [de

  17. Standard operating procedures for collection of soil and sediment samples for the Sediment-bound Contaminant Resiliency and Response (SCoRR) strategy pilot study

    Science.gov (United States)

    Fisher, Shawn C.; Reilly, Timothy J.; Jones, Daniel K.; Benzel, William M.; Griffin, Dale W.; Loftin, Keith A.; Iwanowicz, Luke R.; Cohl, Jonathan A.

    2015-12-17

    An understanding of the effects on human and ecological health brought by major coastal storms or flooding events is typically limited because of a lack of regionally consistent baseline and trends data in locations proximal to potential contaminant sources and mitigation activities, sensitive ecosystems, and recreational facilities where exposures are probable. In an attempt to close this gap, the U.S. Geological Survey (USGS) has implemented the Sediment-bound Contaminant Resiliency and Response (SCoRR) strategy pilot study to collect regional sediment-quality data prior to and in response to future coastal storms. The standard operating procedure (SOP) detailed in this document serves as the sample-collection protocol for the SCoRR strategy by providing step-by-step instructions for site preparation, sample collection and processing, and shipping of soil and surficial sediment (for example, bed sediment, marsh sediment, or beach material). The objectives of the SCoRR strategy pilot study are (1) to create a baseline of soil-, sand-, marsh sediment-, and bed-sediment-quality data from sites located in the coastal counties from Maine to Virginia based on their potential risk of being contaminated in the event of a major coastal storm or flooding (defined as Resiliency mode); and (2) respond to major coastal storms and flooding by reoccupying select baseline sites and sampling within days of the event (defined as Response mode). For both modes, samples are collected in a consistent manner to minimize bias and maximize quality control by ensuring that all sampling personnel across the region collect, document, and process soil and sediment samples following the procedures outlined in this SOP. Samples are analyzed using four USGS-developed screening methods—inorganic geochemistry, organic geochemistry, pathogens, and biological assays—which are also outlined in this SOP. Because the SCoRR strategy employs a multi-metric approach for sample analyses, this

  18. The Origin of Stellar Species: constraining stellar evolution scenarios with Local Group galaxy surveys

    Science.gov (United States)

    Sarbadhicary, Sumit; Badenes, Carles; Chomiuk, Laura; Maldonado, Jessica; Caprioli, Damiano; Heger, Mairead; Huizenga, Daniel

    2018-01-01

    Our understanding of the progenitors of many stellar species, such as supernovae, massive and low-mass He-burning stars, is limited because of many poorly constrained aspects of stellar evolution theory. For my dissertation, I have focused on using Local Group galaxy surveys to constrain stellar evolution scenarios by measuring delay-time distributions (DTD). The DTD is the hypothetical occurrence rate of a stellar object per elapsed time after a brief burst of star formation. It is the measured distribution of timescales on which stars evolve, and therefore serves as a powerful observational constraint on theoretical progenitor models. The DTD can be measured from a survey of stellar objects and a set of star-formation histories of the host galaxy, and is particularly effective in the Local Group, where high-quality star-formation histories are available from resolved stellar populations. I am currently calculating a SN DTD with supernova remnants (SNRs) in order to provide the strongest constraints on the progenitors of thermonuclear and core-collapse supernovae. However, most SNRs do not have reliable age measurements and their evolution depends on the ambient environment. For this reason, I wrote a radio light curve model of an SNR population to extract the visibility times and rates of supernovae - crucial ingredients for the DTD - from an SNR survey. The model uses observational constraints on the local environments from multi-wavelength surveys, accounts for missing SNRs and employs the latest models of shock-driven particle acceleration. The final calculation of the SN DTD in the Local Group is awaiting completion of a systematic SNR catalog from deep radio-continuum images, now in preparation by a group led by Dr. Laura Chomiuk. I have also calculated DTDs for the LMC population of RR Lyrae and Cepheid variables, which serve as important distance calibrators and stellar population tracers. We find that Cepheids can have delay-times between 10 Myrs - 1 Gyr

  19. A multi-site controlled trial of the R&R2MHP cognitive skills program for mentally disordered female offenders.

    Science.gov (United States)

    Jotangia, Amit; Rees-Jones, Angharad; Gudjonsson, Gisli H; Young, Susan

    2015-05-01

    This study aimed to evaluate the acceptability and efficacy of delivering the Reasoning and Rehabilitation Mental Health Program (R&R2MHP) to female mentally disordered offenders detained in medium and low secure hospital settings. Group treatment participants (N = 18) and control participants receiving treatment as usual (N = 20) completed self-report measures pre- and post-group. An informant measure of ward behavior was also completed by staff. Violent attitudes and locus of control were assessed at 3-month follow-up. Program completion was excellent (89%). A conservative intention-to-treat analysis found significant treatment effects post-group for positive problem-solving orientation, rational problem-solving style, and locus of control (medium-large effect), but no treatment effect for violent attitudes, anger, and ward behavior. At follow-up, a large treatment effect was found for locus of control. Ad hoc per protocol analyses found a large treatment effect for ward behavior. The findings provide preliminary support for the feasibility and utility of delivering R&R2MHP to females in secure psychiatric settings. © The Author(s) 2013.

  20. A non-randomised controlled trial of the R&R2MHP cognitive skills program in high risk male offenders with severe mental illness.

    Science.gov (United States)

    C-Y Yip, Vivienne; Gudjonsson, Gisli H; Perkins, Derek; Doidge, Amie; Hopkin, Gareth; Young, Susan

    2013-10-18

    The growing popularity of offending behavior programs has led to the interest of whether such programs are effective with mentally disordered offenders. This study aimed to evaluate the effectiveness of the Reasoning and Rehabilitation program adapted for offenders with severe mental illness (R&R2 MHP). A sample of 59 adult high risk males detained in a high secure hospital completed questionnaires at baseline and post treatment to assess violent attitudes, anger, coping processes and social problem-solving. An informant measure of social and psychological functioning, including disruptive behavior, was completed by staff at the same time. The data of 30 patients who participated in the group condition were compared using intention to treat analysis with 29 controls who received treatment as usual. 80% of group participants completed the program. In contrast to controls, significant medium-large treatment effects were found at outcome on self-reported measures of violent attitudes, social problem-solving and coping processes. Improvements were endorsed by informant ratings of disruptive behavior, social and psychological functioning. The R&R2MHP had a comparatively low dropout rate and was effective in a sample of high risk mentally disordered offenders requiring detention in high security. Future research should use a randomized controlled design. Current Controlled Trials ACTRN12613000216718.

  1. A new method based on fractal variance function for analysis and quantification of sympathetic and vagal activity in variability of R-R time series in ECG signals

    Energy Technology Data Exchange (ETDEWEB)

    Conte, Elio [Department of Pharmacology and Human Physiology and Tires, Center for Innovative Technologies for Signal Detection and Processing, University of Bari, Bari (Italy); School of Advanced International Studies on Nuclear, Theoretical and Nonlinear Methodologies-Bari (Italy)], E-mail: fisio2@fisiol.uniba.it; Federici, Antonio [Department of Pharmacology and Human Physiology and Tires, Center for Innovative Technologies for Signal Detection and Processing, University of Bari, Bari (Italy); Zbilut, Joseph P. [Department of Molecular Biophysics and Physiology, Rush University Medical Center, 1653W Congress, Chicago, IL 60612 (United States)

    2009-08-15

    It is known that R-R time series calculated from a recorded ECG, are strongly correlated to sympathetic and vagal regulation of the sinus pacemaker activity. In human physiology it is a crucial question to estimate such components with accuracy. Fourier analysis dominates still to day the data analysis efforts of such data ignoring that FFT is valid under some crucial restrictions that results largely violated in R-R time series data as linearity and stationarity. In order to go over such approach, we introduce a new method, called CZF. It is based on variogram analysis. It is aimed from a profound link with Recurrence Quantification Analysis that is a basic tool for investigation of non linear and non stationary time series. Therefore, a relevant feature of the method is that it finally may be applied also in cases of non linear and non stationary time series analysis. In addition, the method enables also to analyze the fractal variance function, the Generalized Fractal Dimension and, finally, the relative probability density function of the data. The CZF gives very satisfactory results. In the present paper it has been applied to direct experimental cases of normal subjects, patients with hypertension before and after therapy and in children under some different conditions of experimentation.

  2. In vitro genotoxicity of microcystin-RR on primary cultured rat hepatocites and Hep G2 cell line detected by Comet assay

    International Nuclear Information System (INIS)

    Zegura, B.; Filipic, M.; Lah Turnsek, T.; Sedmak, B.; Suput, D.

    2002-01-01

    Microcystins are hepatotoxic cyclic heptapeptides produced by different species of bloom forming cyanobacteria (Microcystis, Anabaena, Nostoc Oscillatoria). The primary target of the toxin is the liver. The uptake of microcystins into the hepatocites occurs via carrier-mediated transport system. Microcystins cause cytoskeletal damage, necrosis and pooling of blood in the liver, with a consequent increase in the liver weight. The cause of death is a massive hepatic haemorrhage. Microcystins are inhibitors of serine/threonine protein phosphatases 1 and 2A and act as tumor-promoters. Ito and coworkers demonstrated that microcystins induced neoplastic nodules in the liver after repeated injections without an initiator, which indicates that they might act also as tumor initiators. The aim of our studies was to elucidate possible genotoxic effects of microcystin-RR (MCYST-RR) at molecular level using Comet assay. The Comet assay is a sensitive method for detection of DNA strand breaks at the level of a single cell. DNA single-strand breaks can lead to mutations, which are the first step in carcinogensis. (author)

  3. A new method based on fractal variance function for analysis and quantification of sympathetic and vagal activity in variability of R-R time series in ECG signals

    International Nuclear Information System (INIS)

    Conte, Elio; Federici, Antonio; Zbilut, Joseph P.

    2009-01-01

    It is known that R-R time series calculated from a recorded ECG, are strongly correlated to sympathetic and vagal regulation of the sinus pacemaker activity. In human physiology it is a crucial question to estimate such components with accuracy. Fourier analysis dominates still to day the data analysis efforts of such data ignoring that FFT is valid under some crucial restrictions that results largely violated in R-R time series data as linearity and stationarity. In order to go over such approach, we introduce a new method, called CZF. It is based on variogram analysis. It is aimed from a profound link with Recurrence Quantification Analysis that is a basic tool for investigation of non linear and non stationary time series. Therefore, a relevant feature of the method is that it finally may be applied also in cases of non linear and non stationary time series analysis. In addition, the method enables also to analyze the fractal variance function, the Generalized Fractal Dimension and, finally, the relative probability density function of the data. The CZF gives very satisfactory results. In the present paper it has been applied to direct experimental cases of normal subjects, patients with hypertension before and after therapy and in children under some different conditions of experimentation.

  4. Teores de Elementos Minerais e Caracterização Física da Uva Isabel (Vitis labrusca L. Produzida em Boa Vista/RR

    Directory of Open Access Journals (Sweden)

    Magda Márcia Becker

    2014-07-01

    Full Text Available The Roraima viticulture began in 2003 with the creation of the Vale do Rio Branco project, in which the cultivation of grapes was enlarged for a commercial production. However, no information has been found in literature  about the mineral content of grapes produced. Considering the essentiality and importance of this information for human nutrition, quantification of species K by flame photometry and Ca, Fe and Zn by flame atomic absorption spectrometry in pulps of grapes of the Isabel, Vitis labrusca L. variety, cultivated in Boa Vista/RR has been realized, as well as determination of the physical characteristics of the grape bunches and berries. The determinations´ results indicate that K had the highest concentration, followed by Ca, Fe and Zn, being similar to the data, described in other literature sources, except for Ca, which showed smaller, indicating an intervention demand of culture methods employed to optimize the absorption of this species by vines. The consumption of Isabel grape can contribute to the achievement of the adequate intake recommendations of mineral elements. The results of the physical characterization let us classify Isabel grape bunches to very small, loose and green stalks. Overall, this study reveals new data about the physical characteristics and mineral composition present in Isabel grape grown in Boa Vista/RR.

  5. Two-color photographic photometry of variables in the globular cluster M28

    International Nuclear Information System (INIS)

    Wehlau, A.; Butterworth, S.

    1990-01-01

    Visual magnitudes have been measured for 20 variables on 32 plates of M28. These have been combined with previously published as well as newly determined blue magnitudes in order to obtain colors for the variables. Blue and visual light curves are presented for 15 of the the variables, including one W Virginis star V4, one RV Tauri star V17, one field Mira variable V7, nine cluster RR Lyrae stars, and three field RR Lyrae stars. It is shown that V14, previously thought to be a c type RR Lyrae star, is to the red of the instability strip. The visual light curve of V9 suggests that the star may be a member of a binary or a very close optical double. Possible evidence for differential reddening in the vicinity of M28 is presented. The bimodal distribution of the periods of the RR Lyrae stars in M28 may indicate a spread in metallicity among the RR Lyrae variables. 16 refs

  6. CCR5Δ32 Polymorphism Associated with a Slower Rate Disease Progression in a Cohort of RR-MS Sicilian Patients

    Directory of Open Access Journals (Sweden)

    Rosalia D'Angelo

    2011-01-01

    Full Text Available Multiple sclerosis (MS disease is carried through inflammatory and degenerative stages. Based on clinical feaures, it can be subdivided into three groups: relapsing-remitting MS, secondary progressive MS, and primary progressive MS. Multiple sclerosis has a multifactorial etiology with an interplay of genetic predisposition, environmental factors, and autoimmune inflammatory mechanism in which play a key role CC-chemokines and its receptors. In this paper, we studied the frequency of CCR5 gene Δ32 allele in a cohort of Sicilian RR-MS patients comparing with general Sicilian population. Also, we evaluate the association between this commonly polymorphism and disability development and age of disease onset in the same cohort. Our results show that presence of CCR5Δ32 is significantly associated with expanded disability status scale score (EDSS but not with age of disease onset.

  7. VARIABLE STARS IN THE GLOBULAR CLUSTER NGC 2808

    International Nuclear Information System (INIS)

    Kunder, Andrea; Walker, Alistair R.; Stetson, Peter B.; Catelan, Márcio; Amigo, Pía

    2013-01-01

    The first calibrated broadband BVI time-series photometry is presented for the variable stars in NGC 2808, with observations spanning a range of 28 years. We have also redetermined the variability types and periods for the variable stars identified previously by Corwin et al., revising the number of probable fundamental-mode RR Lyrae variables (RR0) to 11 and the number of first-overtone variables (RR1) to five. Our observations were insufficient to discern the nature of the previously identified RR1 star, V24, and the tentatively identified RR1 star, V13. These two variables are ∼0.8 mag brighter than the RR Lyrae variables, appear to have somewhat erratic period and/or luminosity changes, and lie inside the RR Lyrae instability strip. Curiously, all but one of the RR Lyrae stars studied in this relatively metal-rich cluster exhibit the Blazhko phenomenon, an effect thought to occur with higher frequency in metal-poor environments. The mean periods of the RR0 and RR1 variables are (P) RR0 = 0.56 ± 0.01 d and RR1 = 0.30 ± 0.02 d, respectively, supporting an Oosterhoff I classification of the cluster. On the other hand, the number ratio of RR1-to-RR0-type variables is high, though not unprecedented, for an Oosterhoff I cluster. The RR Lyrae variables have no period shifts at a given amplitude compared to the M3 variables, making it unlikely that these variables are He enhanced. Using the recent recalibration of the RR Lyrae luminosity scale by Catelan and Cortés, a mean distance modulus of (m – M) V = 15.57 ± 0.13 mag for NGC 2808 is obtained, in good agreement with that determined here from its type II Cepheid and SX Phoenicis population. Our data have also allowed the discovery of two new candidate SX Phoenicis stars and an eclipsing binary in the blue straggler region of the NGC 2808 color-magnitude diagram.

  8. Little Bear’s pulsating stars: Variable star census of UMi dSph Galaxy

    Directory of Open Access Journals (Sweden)

    Kinemuchi K.

    2017-01-01

    Full Text Available Recent observations and a photometric search for variable stars in the Ursa Minor dwarf spheroidal galaxy (UMi dSph are presented. Our observations were taken at Apache Point Observatory in 2014 and 2016 using the 0.5m ARCSAT telescope and the West Mountain Observatory (WMO 0.9m telescope of Brigham Young University in 2016. Previously known RR Lyrae stars in our field of view of the UMi dSph are identified, and we also catalog new variable star candidates. Tentative classifications are given for some of the new variable stars. We have conducted period searches with the data collected with the WMO telescope. Our ultimate goal is to create an updated catalog of variable stars in the UMi dSph and to compare the RR Lyrae stellar characteristics to other RR Lyrae stars found in the Local Group dSph galaxies.

  9. Double-mode pulsation

    International Nuclear Information System (INIS)

    Cox, A.N.

    1982-01-01

    Double mode pulsation is a very pervasive phenomenon in stars all over the Hertzsprung-Russell diagram. In order of increasing radius, examples are: ZZ Ceti stars, the sun, the delta Scuti stars, RR Lyrae variables, the β Cephei variables and those related to them, Cepheids, and maybe even the Mira stars. These many modes have been interpreted as both radial and nonradial modes, but in many cases the actual mode has not been clearly identified. Yellow giants seem to be the most simple pulsators with a large majority of the RR Lyrae variables and Cepheids showing only one pulsation period. We limit this review to those very few cases for classical Cepheids and RR Lyrae variables which display two modes. For these we know many facts about these stars, but the actual cause of the pulsation in two modes simultaneously remains unknown

  10. Power law behavior of RR-interval variability in healthy middle-aged persons, patients with recent acute myocardial infarction, and patients with heart transplants

    Science.gov (United States)

    Bigger, J. T. Jr; Steinman, R. C.; Rolnitzky, L. M.; Fleiss, J. L.; Albrecht, P.; Cohen, R. J.

    1996-01-01

    BACKGROUND. The purposes of the present study were (1) to establish normal values for the regression of log(power) on log(frequency) for, RR-interval fluctuations in healthy middle-aged persons, (2) to determine the effects of myocardial infarction on the regression of log(power) on log(frequency), (3) to determine the effect of cardiac denervation on the regression of log(power) on log(frequency), and (4) to assess the ability of power law regression parameters to predict death after myocardial infarction. METHODS AND RESULTS. We studied three groups: (1) 715 patients with recent myocardial infarction; (2) 274 healthy persons age and sex matched to the infarct sample; and (3) 19 patients with heart transplants. Twenty-four-hour RR-interval power spectra were computed using fast Fourier transforms and log(power) was regressed on log(frequency) between 10(-4) and 10(-2) Hz. There was a power law relation between log(power) and log(frequency). That is, the function described a descending straight line that had a slope of approximately -1 in healthy subjects. For the myocardial infarction group, the regression line for log(power) on log(frequency) was shifted downward and had a steeper negative slope (-1.15). The transplant (denervated) group showed a larger downward shift in the regression line and a much steeper negative slope (-2.08). The correlation between traditional power spectral bands and slope was weak, and that with log(power) at 10(-4) Hz was only moderate. Slope and log(power) at 10(-4) Hz were used to predict mortality and were compared with the predictive value of traditional power spectral bands. Slope and log(power) at 10(-4) Hz were excellent predictors of all-cause mortality or arrhythmic death. To optimize the prediction of death, we calculated a log(power) intercept that was uncorrelated with the slope of the power law regression line. We found that the combination of slope and zero-correlation log(power) was an outstanding predictor, with a

  11. Investigating the limitations of single breath-hold renal artery blood flow measurements using spiral phase contrast MR with R-R interval averaging.

    Science.gov (United States)

    Steeden, Jennifer A; Muthurangu, Vivek

    2015-04-01

    1) To validate an R-R interval averaged golden angle spiral phase contrast magnetic resonance (RAGS PCMR) sequence against conventional cine PCMR for assessment of renal blood flow (RBF) in normal volunteers; and 2) To investigate the effects of motion and heart rate on the accuracy of flow measurements using an in silico simulation. In 20 healthy volunteers RAGS (∼6 sec breath-hold) and respiratory-navigated cine (∼5 min) PCMR were performed in both renal arteries to assess RBF. A simulation of RAGS PCMR was used to assess the effect of heart rate (30-105 bpm), vessel expandability (0-150%) and translational motion (x1.0-4.0) on the accuracy of RBF measurements. There was good agreement between RAGS and cine PCMR in the volunteer study (bias: 0.01 L/min, limits of agreement: -0.04 to +0.06 L/min, P = 0.0001). The simulation demonstrated a positive linear relationship between heart rate and error (r = 0.9894, P 100 bpm), or when there is significant motion (vessel expandability: >80%, vessel translation: >x2.2). © 2014 Wiley Periodicals, Inc.

  12. Antecipação e retardamento de colheita nos teores de óleo e proteína das sementes de soja, cultivar Valiosa RR

    Directory of Open Access Journals (Sweden)

    Everton Luis Finoto

    2017-01-01

    Full Text Available The objective of this work was to evaluate the physiological quality and oil and prote in content of soybean seeds harvested in different stages of plant development and different periods of harvest delay. The cultivar studied was BRS Valiosa RR and the experimental design was of randomized blocks with three replications. Eleven treatments w ere established, constituting different times of harvest in the following stages: R 5,1 , R 5,3 , R 5,5 , R 6 , R 7,1 , R 7,3 , R 8,1 , R 9 , R 9+10days , R 9+20 days and R 9+30 days . The anticipation of the harvest was made possible through the application in predetermined s tages, of herbicide Diquat (400 g ha - 1 with manual coastal spray with nozzle "type fan" set to volume of 300 L ha - 1 . After the harvest it was done the evaluation of physiological quality of seeds and the determination of the levels of oil and protein. It was noted that the stadium R 7.1 was the harvest season that showed the highest percentage in the germination test, demonstrating that the anticipation of the harvest did not caused significant loss in seed vigor. At the grain filling stage, oil levels were lower and protein larger. Both stabilized from R 7.1 to the R 9 stadium and showed downward trend with the harvest delay.

  13. Cepheid pulsation theory and multiperiodic cepheid variables

    International Nuclear Information System (INIS)

    Cox, A.N.; Cox, J.P.

    1975-01-01

    In this review of the multiperiodic Cepheid variables, the subject matter is divided into four parts. The first discusses general causes of pulsation of Cepheids and other variable stars, and their locations on the H-R diagram. In the second section, the linear adiabatic and nonadiabatic theory calculation of radial pulsation periods and their application to the problem of masses and double-mode Cepheids are reviewed. Periodic solutions, and their stability, of the nonlinear radial pulsation equations for Cepheids and RR Lyrae stars are considered in the third section. The last section provides the latest results on nonlinear, nonperiodic, radial pulsations for Cepheids and RR Lyrae stars. (BJG)

  14. Stellar population of NGC 1850 in the LMC

    Science.gov (United States)

    Gilmozzi, Roberto; Panagia, Nino

    1992-01-01

    Observations of the globular cluster NGC 1850 taken with the HST Wide Field Camera are used to constrain the stellar population of this member of the Large Magellanic Cloud. Three exposures were obtained for each band at exposure times of 10, 100, and 1100 seconds, and the longest exposure was halved to minimize the effects of cosmic noise and the saturation of bright objects. A total of about 12,000 stars with magnitudes of 14-24 and masses of 0.8-13 solar mass are measured, and the age of NGC 1850 is given at approximately 25 million years.

  15. Interconversion of η3-H2SiRR' σ-complexes and 16-electron silylene complexes via reversible H-H or C-H elimination.

    Science.gov (United States)

    Lipke, Mark C; Neumeyer, Felix; Tilley, T Don

    2014-04-23

    Solid samples of η(3)-silane complexes [PhBP(Ph)3]RuH(η(3)-H2SiRR') (R,R' = Et2, 1a; PhMe, 1b; Ph2, 1c, MeMes, 1d) decompose when exposed to dynamic vacuum. Gas-phase H2/D2 exchange between isolated, solid samples of 1c-d3 and 1c indicate that a reversible elimination of H2 is the first step in the irreversible decomposition. An efficient solution-phase trap for hydrogen, the 16-electron ruthenium benzyl complex [PhBP(Ph)3]Ru[η(3)-CH2(3,5-Me2C6H3)] (3) reacts quantitatively with H2 in benzene via elimination of mesitylene to form the η(5)-cyclohexadienyl complex [PhBP(Ph)3]Ru(η(5)-C6H7) (4). This H2 trapping reaction was utilized to drive forward and quantify the elimination of H2 from 1b,d in solution, which resulted in the decomposition of 1b,d to form 4 and several organosilicon products that could not be identified. Reaction of {[PhBP(Ph)3]Ru(μ-Cl)}2 (2) with (THF)2Li(SiHMes2) forms a new η(3)-H2Si species [PhBP(Ph)3]Ru[CH2(2-(η(3)-H2SiMes)-3,5-Me2C6H2)] (5) which reacts with H2 to form the η(3)-H2SiMes2 complex [PhBP(Ph)3]RuH(η(3)-H2SiMes2) (1e). Complex 1e was identified by NMR spectroscopy prior to its decomposition by elimination of Mes2SiH2 to form 4. DFT calculations indicate that an isomer of 5, the 16-electron silylene complex [PhBP(Ph)3]Ru(μ-H)(═SiMes2), is only 2 kcal/mol higher in energy than 5. Treatment of 5 with XylNC (Xyl = 2,6-dimethylphenyl) resulted in trapping of [PhBP(Ph)3]Ru(μ-H)(═SiMes2) to form the 18-electron silylene complex [PhBP(Ph)3]Ru(CNXyl)(μ-H)(═SiMes2) (6). A closely related germylene complex [PhBP(Ph)3]Ru[CN(2,6-diphenyl-4-MeC6H2)](H)(═GeH(t)Bu) (8) was prepared from reaction of (t)BuGeH3 with the benzyl complex [PhBP(Ph)3]Ru[CN(2,6-diphenyl-4-MeC6H2)][η(1)-CH2(3,5-Me2C6H3)] (7). Single crystal XRD analysis indicated that unlike for 6, the hydride ligand in 8 is a terminal hydride that does not engage in 3c-2e Ru-H → Ge bonding. Complex 1b is an effective precatalyst for the catalytic Ge-H dehydrocoupling

  16. 研究炉事故・故障データベースシステム,IDAS-RR; 使用手引書

    OpenAIRE

    松本 潔; 鴻坂 厚夫; 神永 雅紀; 村山 洋二; 大西 信秋; 間庭 正樹

    1990-01-01

    国内外の研究炉の事故・故障に関する情報を収録した研究炉事故・故障データベースシステムIDAS-RR(Incident Data Base System for Research Reactors)を開発した。IDAS-RRは、メニュー形式によってデータの入力、検索、更新、集計処理等、様々な形態の利用が可能なデータベースシステムであり、パーソナルコンピュータPC-9801上で作動する。IDAS-RRは、現在の目的も含め、研究炉を所有する機関に有用なデータベースと考えられる。1)研究炉における事故・故障分析の対象もしくは参考データ、2)研究炉異常診断システムの知識ベース構築のための解析用起因事象参考データ、3)研究炉における緊急時計画の策定の参考データ、本報告書はIDAS-RRの使用手引書である。...

  17. A quantitative approach to study the effect of local texture and heterogeneous plastic strain on the deformation micromechanism in RR1000 nickel-based superalloy

    International Nuclear Information System (INIS)

    Birosca, S.; Di Gioacchino, F.; Stekovic, S.; Hardy, M.

    2014-01-01

    In a weakly textured material with relatively pore-free and homogeneous microstructure, the local texture can influence primary crack propagation and secondary crack initiation, depending on specific microtexture cluster size. Moreover, the plastic strain assessment and strain quantity within individual grains are essential for understanding the material susceptibility to crack initiation and propagation at various loading conditions and temperature ranges. In the current study, electron backscatter diffraction (EBSD) is applied to measure the plastic strain present in RR1000 nickel-based superalloy microstructure following thermo-mechanical fatigue tests. The EBSD plastic strain measurements are evaluated to identify the distinctive deformation mode within individual grains. It was evident from the overall statistical analyses carried out for over 2000 grains that cube (〈0 0 1〉//loading direction) and near cube orientations (φ 1 , Φ, φ 2 : 0, 0–15, 0) behaved as “soft” grains with a high Schmid factor and contained low geometrically necessary dislocation (GND) density as a result of low strain hardening at the early stage of deformation for such grains. The near cube orientation (typically φ 1 , Φ, φ 2 : 0, 9, 0) was the softest orientation among the cube family. While the brass grains (〈1 1 1〉//loading direction) acted as “hard” grains that have the lowest Schmid factor with the highest Taylor factor and GND density compared with other oriented grains. A high GND content was found in the vicinity of the grain boundaries in the soft grains and on slip plane traces within the hard grains. It is concluded that GND absolute value for each grain can vary, as it is interrelated with deformation degree, but the GND locations within the grains give indications of the strain hardening state and deformation stages in hard and soft grains. Furthermore, the areas with random local texture contained high strain incompatibilities between neighbouring

  18. Gemcitabine-Based Chemogene Therapy for Pancreatic Cancer Using Ad-dCK::UMK GDEPT and TS/RR siRNA Strategies

    Directory of Open Access Journals (Sweden)

    Soukaina Réjiba

    2009-07-01

    Full Text Available Gemcitabine is a first-line agent for advanced pancreatic cancer therapy. However, its efficacy is often limited by its poor intracellular metabolism and chemoresistance. To exert its antitumor activity, gemcitabine requires to be converted to its active triphosphate form. Thus, our aim was to improve gemcitabine activation using gene-directed enzyme prodrug therapy based on gemcitabine association with the deoxycytidine kinase::uridine monophosphate kinase fusion gene (dCK::UMK and small interference RNA directed against ribonucleotide reductase (RRM2 and thymidylate synthase (TS. In vitro, cytotoxicity was assessed by 3-[4,5-dimethylthiazol-2-yl]-3,5-diphenyl tetrazolium bromide and [3H]thymidine assays. Apoptosis-related gene expression and activity were analyzed by reverse transcription-polymerase chain reaction, Western blot, and ELISA. For in vivo studies, the treatment efficacy was evaluated on subcutaneous and orthotopic pancreatic tumor models. Our data indicated that cell exposure to gemcitabine induced a down-regulation of dCK expression and up-regulation of TS and RR expression in Panc1-resistant cells when compared with BxPc3- and HA-hpc2-sensitive cells. The combination of TS/RRM2 small interference RNA with Ad-dCK::UMK induced a 40-fold decrease of gemcitabine IC50 in Panc1 cells. This strong sensitization was associated to apoptosis induction with a remarkable increase in TRAIL expression and a diminution of gemcitabine-induced nuclear factor-κB activity. In vivo, the gemcitabine-based tritherapy strongly reduced tumor volumes and significantly prolonged mice survival. Moreover, we observed an obvious increase of apoptosis and decrease of cell proliferation in tumors receiving the tritherapy regimens. Together, these findings suggest that simultaneous TS/RRM2-gene silencing and dCK::UMK gene overexpression markedly improved gemcitabine's therapeutic activity. Clearly, this combined strategy warrants further investigation.

  19. Ships Passing in the Night: Spectroscopic Analysis of Two Ultra-faint Satellites in the Constellation Carina

    Science.gov (United States)

    Li, T. S.; Simon, J. D.; Pace, A. B.; Torrealba, G.; Kuehn, K.; Drlica-Wagner, A.; Bechtol, K.; Vivas, A. K.; van der Marel, R. P.; Wood, M.; Yanny, B.; Belokurov, V.; Jethwa, P.; Zucker, D. B.; Lewis, G.; Kron, R.; Nidever, D. L.; Sánchez-Conde, M. A.; Ji, A. P.; Conn, B. C.; James, D. J.; Martin, N. F.; Martinez-Delgado, D.; Noël, N. E. D.; MagLiteS Collaboration

    2018-04-01

    We present Magellan/IMACS, Anglo-Australian Telescope/AAOmega+2dF, and Very Large Telescope/GIRAFFE+FLAMES spectroscopy of the Carina II (Car II) and Carina III (Car III) dwarf galaxy candidates, recently discovered in the Magellanic Satellites Survey (MagLiteS). We identify 18 member stars in Car II, including two binaries with variable radial velocities and two RR Lyrae stars. The other 14 members have a mean heliocentric velocity {v}hel}=477.2+/- 1.2 {km} {{{s}}}-1 and a velocity dispersion of {σ }v={3.4}-0.8+1.2 {km} {{{s}}}-1. Assuming Car II is in dynamical equilibrium, we derive a total mass within the half-light radius of {1.0}-0.4+0.8× {10}6 {M}ȯ , indicating a mass-to-light ratio of {369}-161+309 {M}ȯ /{L}ȯ . From equivalent width measurements of the calcium triplet lines of nine red giant branch (RGB) stars, we derive a mean metallicity of {{[Fe/H]}}=-2.44+/- 0.09 with dispersion {σ }{{[Fe/H]}}={0.22}-0.07+0.10. Considering both the kinematic and chemical properties, we conclude that Car II is a dark-matter-dominated dwarf galaxy. For Car III, we identify four member stars, from which we calculate a systemic velocity of {v}hel}={284.6}-3.1+3.4 {km} {{{s}}}-1. The brightest RGB member of Car III has a metallicity of {{[Fe/H]}} =-1.97+/- 0.12. Due to the small size of the Car III spectroscopic sample, we cannot conclusively determine its nature. Although these two systems have the smallest known physical separation ({{Δ }}d∼ 10 {kpc}) among Local Group satellites, the large difference in their systemic velocities, ∼ 200 {km} {{{s}}}-1, indicates that they are unlikely to be a bound pair. One or both systems are likely associated with the Large Magellanic Cloud (LMC), and may remain LMC satellites today. No statistically significant excess of γ-ray emission is found at the locations of Car II and Car III in eight years of Fermi-LAT data.

  20. THE LEO IV DWARF SPHEROIDAL GALAXY: COLOR-MAGNITUDE DIAGRAM AND PULSATING STARS

    International Nuclear Information System (INIS)

    Moretti, Maria Ida; Dall'Ora, Massimo; Ripepi, Vincenzo

    2009-01-01

    We present the first V, B - V color-magnitude diagram of the Leo IV dwarf spheroidal galaxy, a faint Milky Way satellite recently discovered by the Sloan Digital Sky Survey. We have obtained B, V time-series photometry reaching about half a magnitude below the Leo IV turnoff, which we detect at V = 24.7 mag, and have performed the first study of the variable star population. We have identified three RR Lyrae stars (all fundamental-mode pulsators, RRab) and one SX Phoenicis variable in the galaxy. In the period-amplitude diagram the Leo IV RR Lyrae stars are located close to the loci of Oosterhoff type I systems and the evolved fundamental-mode RR Lyrae stars in the Galactic globular cluster M3. However, their mean pulsation period, (Pab) = 0.655 days, would suggest an Oosterhoff type II classification for this galaxy. The RR Lyrae stars trace very well the galaxy's horizontal branch, setting its average magnitude at (V RR ) = 21.48 ± 0.03 mag (standard deviation of the mean). This leads to a distance modulus of μ 0 = 20.94 ± 0.07 mag, corresponding to a distance of 154 ± 5 kpc, by adopting for the Leo IV dSph a reddening E(B - V) = 0.04 ± 0.01 mag and a metallicity of [Fe/H] = -2.31 ± 0.10.

  1. A Percepção dos Visitantes quanto as Informações Turísticas na Rodoviária Internacional de Boa Vista, RR

    Directory of Open Access Journals (Sweden)

    Rita Michelin

    2014-04-01

    Full Text Available Normal 0 false false false PT-BR JA X-NONE Considerando o Turismo como um fenômeno social de grande importância, a presente pesquisa teve por objetivo principal analisar a percepção dos visitantes acerca da hospitalidade pública de recepção na Rodoviária Internacional de Boa Vista (RBV, em Roraima, através da disponibilização de informações turísticas. Atualmente, a Rodoviária recebe um grande fluxo de visitantes, no entanto, não existe ali um local que preste as informações básicas quanto ao Turismo e aos serviços locais, para quem chega a cidade. Tendo por premissa que o viés da hospitalidade deve ser considerado desde o primeiro momento em que o visitante chega a um destino turístico, a hospitalidade pública representada pelas informações turística faz-se de fundamental importância para bem receber o turista e, consequentemente, levá-lo a perceber o município como um destino turístico hospitaleiro.Perception of visitors on the Tourist Office at the International Bus Station Boa Vista, RR - Considering tourism as a social phenomenon of great importance, the research objective was to analyze the perception of the visitors about public hospitality on International Bus Station of Boa Vista (RBV through the availability of tourist information. Currently the bus station receives a large number of visitors; however, there isn’t a place that provides basic information about the tourism and local services. Having premised that the hospitality must be considered from the first moment the visitor arrives at a destination, the public hospitality represented by the tourist information make it crucial for welcoming tourists and charm you aiming your satisfaction.

  2. Field #3 of the Palomar-Groningen Survey; 1, Variable stars at the edge of the Sagittarius dwarf galaxy

    NARCIS (Netherlands)

    Schultheis, M.

    1996-01-01

    Submitted to: Astron. Astrophys. Abstract: A catalogue is presented with variable (RR Lyrae, semiregular and Mira) stars located inside field #3 of the Palomar-Groningen Survey, at the outer edge of the Sagittarius dwarf galaxy. One of the semiregular variables is a carbon star, comparable with

  3. Variable Stars in (Not Only) Dwarf Galaxies : Key Tools to Constrain Distances and Stellar Content

    NARCIS (Netherlands)

    Fiorentino, G.; Koleva, M; Prugniel, P; Vauglin,

    2011-01-01

    The important role of Cepheid and RR Lyrae variable stars and what they teach us about dwarf galaxies is discussed. Despite ever improving star formation histories of Local Group dwarf galaxies uncertainties remain, in particular in the identification and characterisation of the oldest stellar

  4. Halo star streams in the solar neighborhood

    NARCIS (Netherlands)

    Kepley, Amanda A.; Morrison, Heather L.; Helmi, Amina; Kinman, T. D.; Van Duyne, Jeffrey; Martin, John C.; Harding, Paul; Norris, John E.; Freeman, Kenneth C.

    2007-01-01

    We have assembled a sample of halo stars in the solar neighborhood to look for halo substructure in velocity and angular momentum space. Our sample ( 231 stars) includes red giants, RR Lyrae variable stars, and red horizontal branch stars within 2.5 kpc of the Sun with [Fe/H] less than -1.0. It was

  5. Period--luminosity--color relations and pulsation modes of pulsating variable stars

    International Nuclear Information System (INIS)

    Breger, M.; Bregman, J.N.

    1975-01-01

    The periods of delta Scuti, RR Lyrae, dwarf Cepheid, and W Virginis variables have been investigated for their dependence on luminosity, color, mass, and pulsation modes. A maximum-likelihood method, which includes consideration of the observational errors in each coordinate, has been applied to obtain observational period-luminosity-color (P-L-C) relations

  6. Direct evidence for a massive galactic halo

    International Nuclear Information System (INIS)

    Hawkins, M.R.S.

    1983-01-01

    The discovery of a very distant galactic RR Lyrae star, R15 is reported. Spectroscopic observations of the object show that it has a high negative radial velocity, implying a lower limit to the mass of the galaxy of 1.4 x 10 12 Msun. (author)

  7. Classical variables in the era of space photometric missions

    Directory of Open Access Journals (Sweden)

    Molnár L.

    2015-01-01

    Full Text Available The space photometric missions like CoRoT and Kepler transformed our view of pulsating stars, including the well-known RR Lyrae and Cepheid classes. The K2, TESS and PLATO missions will expand these investigations to larger sample sizes and to specific stellar populations.

  8. Mass of AC Andromedae

    International Nuclear Information System (INIS)

    King, D.S.; Cox, A.N.; Hodson, S.W.

    1975-01-01

    Calculations indicate that AC Andromedae is population I rather than population II. A mass and radius for this star are calculated using a new set of opacities for the Kippenhahn Ia mixture. It is concluded that the mass is too high for an ordinary RR Lyrae star. (BJG)

  9. A Probabilistic Approach to Fitting Period–luminosity Relations and Validating Gaia Parallaxes

    Energy Technology Data Exchange (ETDEWEB)

    Sesar, Branimir; Fouesneau, Morgan; Bailer-Jones, Coryn A. L.; Gould, Andy; Rix, Hans-Walter [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Price-Whelan, Adrian M., E-mail: bsesar@mpia.de [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)

    2017-04-01

    Pulsating stars, such as Cepheids, Miras, and RR Lyrae stars, are important distance indicators and calibrators of the “cosmic distance ladder,” and yet their period–luminosity–metallicity (PLZ) relations are still constrained using simple statistical methods that cannot take full advantage of available data. To enable optimal usage of data provided by the Gaia mission, we present a probabilistic approach that simultaneously constrains parameters of PLZ relations and uncertainties in Gaia parallax measurements. We demonstrate this approach by constraining PLZ relations of type ab RR Lyrae stars in near-infrared W 1 and W 2 bands, using Tycho- Gaia Astrometric Solution (TGAS) parallax measurements for a sample of ≈100 type ab RR Lyrae stars located within 2.5 kpc of the Sun. The fitted PLZ relations are consistent with previous studies, and in combination with other data, deliver distances precise to 6% (once various sources of uncertainty are taken into account). To a precision of 0.05 mas (1 σ ), we do not find a statistically significant offset in TGAS parallaxes for this sample of distant RR Lyrae stars (median parallax of 0.8 mas and distance of 1.4 kpc). With only minor modifications, our probabilistic approach can be used to constrain PLZ relations of other pulsating stars, and we intend to apply it to Cepheid and Mira stars in the near future.

  10. New results from synthetic horizontal branches (SHBs)

    International Nuclear Information System (INIS)

    Quarta, M.L.; Catelan, M.

    1990-01-01

    A preliminary study of an SHB grid is presented. The investigation follows Caputo et al. (1987) and, in addition, introduces the new grid of HB evolutionary tracks devised by Sweigart (1987). The general constraints for theoretical HB stars and RR Lyrae pulsators are examined, with emphasis on the HB morphology, luminosity, and variable mean period. 14 refs

  11. A cautionary tale of interpreting O-C diagrams

    DEFF Research Database (Denmark)

    Skarka, M.; Liska, J.; Dreveny, R.

    2018-01-01

    We present a comprehensive study of Z CVn, an RR Lyrae star that shows long-term cyclic variations of its pulsation period. A possible explanation suggested from the shape of the O-C diagram is the light travel-time effect, which we thoroughly examine. We used original photometric and spectroscop...

  12. Statistical parallaxes and the fundamental distance scale

    International Nuclear Information System (INIS)

    Clube, S.V.M.; Dawe, J.A.

    1980-01-01

    The statistical parallax technique of Paper I is used to derive an absolute magnitude of = 1.0 +- 0.25 mag for the set of 59 high ΔS RR Lyrae stars of Clube and Jones. Taken in conjunction with the kinematical properties of RR Lyrae variables and other field stars, this magnitude leads to the following values for the principal galactic constants: R 0 = approximately 7 +- 1 kpc, A = approximately 16 +- 3 km s -1 kpc -1 , B = approximately -20 +- 5 km s -1 kpc -1 and theta 0 = approximately 250 +- 40 km s -1 . The technique is also applied to Wielen's set of 45 Cepheids and no correction of the galactic Cepheid distance scale based on cluster members is found to be necessary. These sets of results are consistent if, as has been shown elsewhere, the kinematic model used to analyse the motions of young stars takes account of radial motions in the Galaxy. The distances to the Magellanic Clouds given by RR Lyraes and Cepheids are in conflict however. Although the evidence suggesting a general similarity of halo RR Lyraes in our Galaxy and the Magellanic Clouds is not absolutely conclusive, it is suggested that the conflict may be resolved by use of a colour term in the P-L-C relation for Cepheids which is much less than that adopted by Sandage and Tammann. The conclusions are in general accord with recent proposals seeking to increase the Hubble constant to around 80 km s -1 Mpc -1 . (author)

  13. Vakıf Kurumunun Dayandığı Temel Referanslar Ve Zürrî Vakıfların Vakıf Sistemindeki Yeri

    Directory of Open Access Journals (Sweden)

    Yasin Yılmaz

    2014-06-01

    Full Text Available Bu çalışmada İslam’da kurumsal yardımlaşmayı temsil eden vakıf kurumunun, Kitap ve Sünnetteki referansları ile Allah rızası hedeflenerek kurulan vakıflara Hz. Peygamber, Raşit halifeler ve sahabenin bakışı ile daha sonraki yüzyıllarda özellikle Osmanlı uygulaması üzerinde durulmuş, özelde de aile vakıflarının genel durumları açıklanmıştır. Vakıf kurumunun özellikle de zürrî vakıfların serencamını ortaya çıkarabilmek için vakfiyeler, vakıfla ilgili kronikler ve konuyla ilgili ikincil çalışmalar ele alınarak incelenmiştir. Ebu Yusuf’un fetvası doğrultusunda kurulan, aile vakıflarının lehinde ve aleyhinde ortaya çıkan görüşler doğrultusunda ortak bir noktaya ulaşılmaya çalışılmıştır. Çalışmanın sonunda da, bazı zürrî vakıfların vakfiyelerin incelenmesi sonucunda elde edilen bilgilerle, evlatlık-zürrî vakıfların genel özellikleri örneklerle ortaya konulmuştur

  14. Higher-dimensional string theory in Lyra geometry

    Indian Academy of Sciences (India)

    Cosmic strings as source of gravitational field in general relativity was discussed by ... tensor theory of gravitation and constructed an analog of Einstein field ... As string concept is useful before the particle creation and can explain galaxy for-.

  15. Evolutionary changes in the eclipsing binary .beta. Lyrae

    Czech Academy of Sciences Publication Activity Database

    Harmanec, Petr

    1999-01-01

    Roč. 43, 6-7 (1999), s. 491-497 ISSN 1387-6473. [ General Assembly of the International Astronomical Union /23./. Kyoto, 18.08.1997-30.08.1997] Institutional research plan: CEZ:AV0Z1003909 Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  16. Selections from 2017: Computers Help Us Map Our Home

    Science.gov (United States)

    Kohler, Susanna

    2017-12-01

    Editors note:In these last two weeks of 2017, well be looking at a few selections that we havent yet discussed on AAS Nova from among the most-downloaded paperspublished in AAS journals this year. The usual posting schedule will resume in January.Machine-Learned Identification of RR Lyrae Stars from Sparse, Multi-Band Data: The PS1 SamplePublished April2017Main takeaway:A sample of RR Lyrae variable stars was built from thePan-STARRS1 (PS1) survey by a team led byBranimir Sesar (Max Planck Institute for Astronomy, Germany). The sample of45,000 starsrepresentsthe widest (three-fourthsof the sky) and deepest (reaching 120 kpc) sample of RR Lyrae stars to date.Why its interesting:Its challengingto understand the overall shape and behaviorof our galaxy because were stuck on the inside of it. RR Lyrae stars are a useful tool for this purpose: they can be used as tracers to map out the Milky Ways halo. The authors large sample of RR Lyrae stars from PS1 combined withproper-motion measurements from Gaia and radial-velocity measurements from multi-object spectroscopic surveys could become thepremier source for studying the structure, kinematics, and the gravitational potential of our galaxys outskirts.How they were found:The black dots show the distribution of the 45,000 probable RR Lyrae stars in the authors sample. [Sesar et al. 2017]The 45,000 stars in this sample were selected not by humans, but by computer.The authors used machine-learning algorithms to examine the light curvesin the Pan-STARRS1 sample and identify the characteristic brightness variations of RR Lyrae stars lying in the galactic halo. These techniques resulted in a very pure and complete sample, and the authors suggest that this approachmay translate well to othersparse,multi-band data sets such asthat from the upcomingLarge Synoptic Survey Telescope (LSST) galactic plane sub-survey.CitationBranimir Sesar et al 2017 AJ 153 204. doi:10.3847/1538-3881/aa661b

  17. Review: Tasos Zembylas & Claudia Dürr (2009. Wissen, Können und literarisches Schreiben. Eine Epistemologie der künstlerischen Praxis [Knowledge, Mastery, and literate Writing. An Epistemology of Artistic Practice

    Directory of Open Access Journals (Sweden)

    Stefan Fothe

    2010-08-01

    Full Text Available Tasos ZEMBYLAS and Claudia DÜRR trace the emergence of prose texts. By analyzing three case studies of young writers, they map a central domain of artistic practice. Their particular focus is on practical knowledge, which they assume to be highly important. However, as it is intimately intermingled with relevant performance, its empirical "capture" is both challenging and attracting. Practical knowledge is often not only implicit, but does not share many of the characteristics of propositional knowledge. The authors reconstruct its relevance, externalization and nature, as well as its individual and cultural shape. This paper focuses on the analysis of the study's theoretical background, the so-called Tacit Knowing View. After an introduction, this framework is applied onto itself. Hence, it can be asked if practical knowledge—as conceptualized within this view—can be empirically captured. It is only then that the study of ZEMBYLAS and DÜRR can be properly valued. The conclusion is drawn that their book represents an important first step on a longer road towards the intended epistemology of artistic practice. Based upon the Tacit Knowing View framework, further steps along this road are suggested. URN: urn:nbn:de:0114-fqs1003298

  18. Identification of novel splice site mutation IVS9 + 1(G > A) and novel complex allele G355R/R359X in Type 1 Gaucher patients heterozygous for mutation N370S.

    Science.gov (United States)

    Hoitsema, Kourtnee; Amato, Dominick; Khan, Aneal; Sirrs, Sandra; Choy, Francis Y M

    2016-09-01

    Gaucher disease is an autosomal recessive lysosomal storage disorder resulting from deficient glucocerebrosidase activity. More than 350 mutations that cause Gaucher disease have been described to date. Novel mutations can potentially provide insight into the glucocerebrosidase structure-function relationship and biochemical basis of the disease. Here, we report the identification of two novel mutations in two unrelated patients with type I (non-neuronopathic) Gaucher disease: 1) a splice site mutation IVS9 + 1G > A; and (2) a complex allele (cis) G355R/R359X. Both patients have a common N370S mutation in the other allele. The splice site mutation results from an intronic base substitution (G to A, c.1328 + 1, g.5005) at the donor splice site of exon and intron 9. The complex allele results from two point mutations in exon 8 of glucocerebrosidase (G to C at c.1180, g.4396, and T to C at c. 1192, g.4408) substituting glycine by arginine (G355R) and arginine by a premature termination (R359X), respectively. In order to demonstrate that G355R/R359X are in cis arrangement, PCR-amplified glucocerebrosidase exon 8 genomic DNA from the patient was cloned into the vector pJET1.2 in Escherichia coli TOP10® strain. Out of the 15 clones that were sequence analyzed, 10 contained the normal allele sequence and 5 contained the complex allele G355R/R359X sequence showing both mutations in cis arrangement. Restriction fragment length polymorphism analysis using Hph1 restriction endonuclease digest was established for the IVS9 + 1G > A mutation for confirmation and efficient identification of this mutation in future patients. Past literature suggests that mutations affecting splicing patterns of the glucocerebrosidase transcript as well as mutations in Gaucher complex alleles are detrimental to enzyme activity. However, compound heterozygosity with N370S, a mild mutation, will lead to a mild phenotype. The cases reported here support these past findings.

  19. Tissue distributions and seasonal dynamics of the hepatotoxic microcystins-LR and -RR in a freshwater snail (Bellamya aeruginosa) from a large shallow, eutrophic lake of the subtropical China

    International Nuclear Information System (INIS)

    Chen Jun; Xie Ping; Guo Longgen; Zheng Li; Ni Leyi

    2005-01-01

    Tissue distributions and seasonal dynamics of the hepatotoxic microcystins-LR and -RR in a freshwater snail (Bellamya aeruginosa) were studied monthly in a large shallow, eutrophic lake of the subtropical China during June-November, 2003. Microcystins (MCs) were quantitatively determined by High-Performance Liquid Chromatography (HPLC) with a qualitative analysis by a Finnigan LC-MS system. On the average of the study period, hepatopancreas was the highest in MC contents (mean 4.14 and range 1.06-7.42 μg g -1 DW), followed by digestive tracts (mean 1.69 and range 0.8-4.54 μg g -1 DW) and gonad (mean 0.715 and range 0-2.62 μg g -1 DW), whereas foot was the least (mean 0.01 and range 0-0.06 μg g -1 DW). There was a positive correlation in MC contents between digestive tracts and hepatopancreas. A constantly higher MC content in hepatopancreas than in digestive tracts indicates a substantial bioaccumulation of MCs in the hepatopancreas of the snail. The average ratio of MC-LR/MC-RR showed a steady increase from digestive tracts (0.44) to hepatopancreas (0.63) and to gonad (0.96), suggesting that MC-LR was more resistant to degradation in the snail. Since most MCs were present in the hepatopancreas, digestive tracts and gonad with only a very small amount in the edible foot, the risk to human health may not be significant if these toxic parts are removed prior to snail consumption. However, the possible transference of toxins along food chains should not be a negligible concern. - Snails bioaccumulate microcystins in their hepatopancreas, gut and gonad, posing a risk to human consumers

  20. QT Interval Adaption to RR Interval Changes and Correlation Analysis between Heart Rate Variability and QT Interval Variability%QT间期对RR间期变化的响应及HRV与QTV的关联性分析

    Institute of Scientific and Technical Information of China (English)

    朱逸; 杨啸林; 彭屹

    2013-01-01

    体表心电图作为无创和连续的监测手段,在心脏安全评测方面具有重要而不可替代的位置.心电图中的间期时间序列包含着重要信息,其中以反映心动周期的RR间期序列,以及以QT间期为代表的反映心室复极化时程的间期序列,在临床上最为基础,相关的研究具有更为重要的意义.文中从应用基础研究的角度,就QT间期对于RR间期变化的响应,以及心率变异性(HRV)和QT间期变异性(QTV)关联性分析,分别介绍了其分析方法和研究进展,并且展望了可能的应用前景.%As a noninvasive and continuous monitoring method, surface electrocardiogram is significant in evaluating cardiac safety. The time interval series extracted from surface electrocardiogran contain important information. The RR and QT interval series, representing the cardiac cycle and the duration of ventricular repolarization, are with more research value. From the perspective of applied basic research, the methods and progress, concerning the QT interval adaption to RR interval changes and correlation analysis between heart rale variability (HRV) and QT interval variability (QTV) , were introduced here. And their potential applications were discussed as well.

  1. Do We Really Have an Age/H_0 Conflict?

    Science.gov (United States)

    Baum, W. A.

    1997-12-01

    Two independent methods for estimating the age of the universe can both be linked to the absolute magnitudes of the RR Lyrae stars, one based on stellar evolution in globular clusters and the other based on the Hubble Constant derived from globular clusters as distance indicators. The latter has recently been extracted from HST-WFPC2 data for globular clusters in the Coma Cluster galaxy IC 4051 (Baum et al. 1997, AJ, 113, 1483). If RR Lyrae stars are brighter than we have previously thought, the stellar-evolution age estimate is shortened whereas the Hubble age is increased, so we can ask a very simple question: For what RR Lyrae magnitude zero point would the stellar-evolution age coincide with the Hubble age, and is it a reasonable value? Allowing 1 Gyr for globular clusters to have formed, and assuming a classical Einstein-deSitter universe with Lambda = 0, I find the two ages to coincide if M_V(RR) ~ 0.16[Fe/H] + 0.46, which (among other things) puts the Large Magellanic Cloud at (m-M) = 18.78 +/- 0.17 mag. The implied age of the universe is 11.0 +/- 1.4 Gyr, and the corresponding H_0 = 59 +/- 8 km/s per Mpc.

  2. Radio Controlled Fish Robot RR-9

    OpenAIRE

    Cifanskis, S; Vība, J; Jakuševičs, V

    2015-01-01

    A remote-controlled underwater robot fish is described. For motion control three actuator drives are used: one actuator is for tail frequency exchange, the second actuator is for the left or right turnings and the third actuator provides neutral swimming or up and down diving. From the robot's center of mass motion theorem (according to the given total mass of robot) the proportional distribution of massesof structural elements is found. Experimental indoor and out...

  3. Management of construction safety at RR site

    International Nuclear Information System (INIS)

    Pathak, B.C.; Khatsuriya, J.R.

    2016-01-01

    Construction industries are one of the most hazardous industries and hence, promotion of safety remains one of the greatest challenges facing construction industry today. According to ILO estimates: Each year at least 60,000 fatal accidents occur on construction sites around the world or one fatal accident every ten minutes. One in six fatal accidents at work occurs on a construction site. In industrialized countries, as many as 25-40 per cent of work related deaths occur on construction sites, even though the sector employs only 6-10 per cent of the workforce. The number of fatalities occurring from construction work in India is also quite disturbing. Though, the fall of person from height and through openings were the major causes for fatal /serious accidents, the risk of fatal accident involving material handling equipment, either during handling or its maintenance is also significantly high due to use of large number of material handling equipments during construction work. (author)

  4. (RR) soybean cultivars estimated by phenotypic characteristics

    African Journals Online (AJOL)

    SAM

    2014-06-25

    Jun 25, 2014 ... phenotypic characteristics and microsatellite molecular markers (SSR). ... discriminatory analysis, principal components, coordinate and cluster analysis .... were employed with 10.000 simulations to attribute significance values to ...... association analysis of protein and oil content in food-grade soybeans ...

  5. Germinação e desenvolvimento inicial de plântulas de soja convencional e sua derivada transgênica RR em condições de estresse salino Germination and initial development of soybean seedlings and their transgenic derivatives in salt stress condition

    Directory of Open Access Journals (Sweden)

    Tereza Cristina de Carvalho

    2012-08-01

    Full Text Available O Brasil destaca-se como um dos maiores produtores mundiais de soja transgênica, sendo sua produção estendida principalmente a regiões com solos salinos, onde há acúmulo de sais que interferem na germinação da semente e no desenvolvimento das plântulas. O objetivo da pesquisa foi avaliar o efeito do estresse salino sobre a germinação e o desenvolvimento inicial de plântulas de soja convencional e sua derivada transgênica Roundup Ready (RR, submetidas a diferentes condições de salinidade. Para tanto, utilizaram-se dois lotes de sementes de soja (CD 206 e CD 206 RR, sendo que os tratamentos constaram dos seguintes níveis de NaCl: zero; 5; 15; 30; 60 e 120mmol L-1. A avaliação da qualidade fisiológica das sementes foi obtida pelos testes de germinação, comprimento de raiz e plântulas, massa seca de plântulas e volume radicular. O estresse salino reduz a germinação das sementes de ambos os genótipos, sendo que o desenvolvimento de plântulas do genótipo transgênico RR é menos sensível em condições de maior salinidade (60 a 120mmol L-1 de NaCl.Brazil stands out as the largest worldwide producer of transgenic soybeans and has extended its production mainly to regions with saline soils, where there is accumulation of salts that interferes in seed germination and seedling development. The object of this research was to evaluate the effect of saline stress on the germination and initial development of soybean conventional seedling and its transgenic derivatives Roundup Ready (RR submitted to different salinity conditions. For that purpose two lots of soybean seeds were used (CD 206 and CD 206 RR, the treatments consisted of the following levels of NaCl: 0, 5, 15, 30, 60 and 120mmol L-1. The evaluation of physiological seed quality was obtained by germination test, root and seedling length, seedling dry mass and volume of roots. The salt stress reduced germination of seeds of both genotypes, and the development of seedling

  6. Mevlana'nın Ölümsüzlüğünün Sırrı / The Mystery of Eternality of Mowlana(His Relations With Shams

    Directory of Open Access Journals (Sweden)

    Tuğberk Uğurlu

    2016-01-01

    Full Text Available The Mystery of Eternality of Mowlana (His Relations With Shams Although, religion is a guide for humanity which is sent to promote humans mundane life and keep balance of society prosperity and social relationships besides helps persons to accomplish their spritual progress and the journey to their creator, unfortunately it also went on one of the main reasons of wars that had occured during the human history and its still going on. During this long human history, humanity extremely witnessed to a lot of falsifier scholars and mystics who abused their goodwills. And thousands of intellectuals and men of religion  has forgotten. However  after over seven centuries Mowlana is still alive as one of the most famous Sufis and as a great leaders for eternal peace, friendship and happiness. What is the secret that in spite of all changes and progress in the ways of life and thinking, in science and technology and in the world of today his many centuries old ideas and thoughts are still valid and shining like the polar star? This article tries to answer this question. Mevlana’nın Ölümsüzlüğünün Sırrı (Şems ile ilişkisi Din, şahısların manevi gelişimini ve kendi yaratıcılarına olan yolculuklarını tamamlayabilmelerinin yanı sıra insanların dünya hayatlarını düzenlemek, toplum refahını ve sosyal ilişkileri dengede tutmak için insanlığa gönderilmiş bir rehber olmasına rağmen maalesef uzun insanlık tarihi boyunca çıkmış savaşların temel sebeplerinden biri de olagelmiştir ve hala da devam etmektedir.  Bu uzun insanlık tarihi boyunca insanlık, sahte sufilerin ve âlimlerin kendilerinin iyi niyetlerini suiistimal etmelerine fazlasıyla şahitlik etmiş ve binlerce düşünürün ve din adamlarının isimleri hafızlardan silinmişken,  yedi asrı aşkın bir sürenin ardından Mevlana, en meşhur sufilerden ve ebedi huzur, dostluk ve mutluluğun ulu önderlerinden biri olarak hala hayattadır. Peki; ya

  7. Co-crystal of (R,R)-1,2-cyclohexanediol with (R,R)-tartaric acid, a key structure in resolution of the ({+-})-trans-diol by supercritical extraction, and the related ternary phase system

    Energy Technology Data Exchange (ETDEWEB)

    Thorey, Paul [Department of Chemical and Environmental Process Engineering, Budapest University of Technology and Economics, H-1521 Budapest (Hungary); Bombicz, Petra [Institute of Structural Chemistry, Chemical Research Center, Hungarian Academy of Science, H-1525 Budapest (Hungary); Szilagyi, Imre Miklos [Material Structure and Modeling Research Group, Hungarian Academy of Sciences, H-1111 Budapest (Hungary); Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, H-1521 Budapest (Hungary); Molnar, Peter; Bansaghi, Gyoergy; Szekely, Edit; Simandi, Bela [Department of Chemical and Environmental Process Engineering, Budapest University of Technology and Economics, H-1521 Budapest (Hungary); Parkanyi, Laszlo [Institute of Structural Chemistry, Chemical Research Center, Hungarian Academy of Science, H-1525 Budapest (Hungary); Pokol, Gyoergy [Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, H-1521 Budapest (Hungary); Madarasz, Janos, E-mail: madarasz@mail.bme.hu [Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, H-1521 Budapest (Hungary)

    2010-01-10

    A novel co-crystal of trans-(R,R)-1,2-cyclohexanediol and (R,R)-tartaric acid (with 1:1 molar ratio, 1) has been found to be a key crystalline compound in the improved resolution of ({+-})-trans-1,2-cyclohexanediol by supercritical fluid extraction. The molecular and crystal structure of this co-crystal, which crystallizes in orthorhombic crystal system (space group P2{sub 1}2{sub 1}2{sub 1}, a = 6.7033(13) A, b = 7.2643(16), c = 24.863(5), Z = 4), has been solved by single crystal X-ray diffraction (R = 0.064). The packing arrangement consists of two dimensional layers of sandwich-like sheets, where the inner part is constructed by double layers of tartaric acids which hydrophilicity is 'covered' on both upper and bottom side by cyclohexanediols with the hydrophobic cyclohexane rings pointing outward. Thus, a rather complex hydrogen bonding pattern is constructed. The relatively high melting point (133 {sup o}C) observed by both simultaneous TG/DTA and DSC, and the main features of FTIR-spectrum of 1 are explained by the increased stability of this crystal structure. DSC studies on binary mixtures of co-crystal 1 with (R,R)-1,2-cyclohexanediol or (R,R)-tartaric acid, revealed eutectic temperatures of T{sub eu} = 100 or 131 {sup o}C, respectively. Between (S,S)-1,2-cyclohexanediol and (R,R)-tartaric acid a eutectic temperature of T{sub eu} = 85 {sup o}C have also been observed. The phase relations have been confirmed by powder X-ray diffraction, as well.

  8. On the building blocks of the M31 and Milky Way halos

    Directory of Open Access Journals (Sweden)

    Monelli Matteo

    2017-01-01

    Full Text Available We discuss the formation of the halo of M31 and the Milky Way as traced by the population of RR Lyrae stars, in comparison with the population of such stars preent in satellite dwarf galaxies. We find that both halos and the massive dwarf host a population of high amplitude short period RRab stars, absent in low-mass dwarfs. These stars are explained as the metal-rich tail of the RR Lyrae distribution ([Fe/H] ∼ - 1.5, and thus their existence imply fast chemical enrichment in the host system. Their presence in both halos implies that massive building blocks had an important role in their formation.

  9. An LBT view of the Andromeda’s satellite galaxies

    Directory of Open Access Journals (Sweden)

    Cusano Felice

    2017-01-01

    Full Text Available Results are presented on deep (V ∼ 26.5 mag time series observations of four dwarf spheroidal galaxies (dSphs in the Andromeda (M31 complex, namely, And XIX, And XXI, And XXV and And XXVII, that we have observed with the Large Binocular Telescope (LBT. We discovered in these galaxies a total of over 200 RR Lyrae stars and 19 Anomalous Cepheids. We also characterised the stellar populations and the spatial distributions of these dSphs.

  10. Stellar candles for the extragalactic distance scale

    CERN Document Server

    Gieren, Wolfgang

    2003-01-01

    This volume reviews the current status with respect to both theory and observation of the extragalactic distance scale. A sufficient accuracy is required both for a precise determination of the cosmological parameters and also in order to achieve a better understanding of physical processes in extragalactic systems. The "standard candles", used to set up the extragalactic distance scale, reviewed in this book include cepheid variables, RR Lyrae variables, novae, Type Ia and Type II supernovae as well as globular clusters and planetary nebulae.

  11. STELLAR ARCHEOLOGY IN THE GALACTIC HALO WITH ULTRA-FAINT DWARFS. VII. HERCULES

    Energy Technology Data Exchange (ETDEWEB)

    Musella, Ilaria; Ripepi, Vincenzo; Marconi, Marcella, E-mail: ilaria@na.astro.it, E-mail: ripepi@na.astro.it, E-mail: marcella@na.astro.it [INAF, Osservatorio Astronomico di Capodimonte, I-8013 Napoli (Italy); and others

    2012-09-10

    We present the first time-series study of the ultra-faint dwarf galaxy Hercules. Using a variety of telescope/instrument facilities we secured about 50 V and 80 B epochs. These data allowed us to detect and characterize 10 pulsating variable stars in Hercules. Our final sample includes six fundamental-mode (ab-type) and three first-overtone (c-type) RR Lyrae stars, and one Anomalous Cepheid. The average period of the ab-type RR Lyrae stars, (P{sub ab}) = 0.68 days ({sigma} = 0.03 days), places Hercules in the Oosterhoff II group, as found for almost the totality of the ultra-faint dwarf galaxies investigated so far for variability. The RR Lyrae stars were used to obtain independent estimates of the metallicity, reddening, and distance to Hercules, for which we find [Fe/H] = -2.30 {+-} 0.15 dex, E(B - V) = 0.09 {+-} 0.02 mag, and (m - M){sub 0} = 20.6 {+-} 0.1 mag, in good agreement with the literature values. We have obtained a V, B - V color-magnitude diagram (CMD) of Hercules that reaches V {approx} 25 mag and extends beyond the galaxy's half-light radius over a total area of 40' Multiplication-Sign 36'. The CMD and the RR Lyrae stars indicate the presence of a population as old and metal-poor as (at least) the Galactic globular cluster M68.

  12. Gaia Data Release 1. Open cluster astrometry: performance, limitations, and future prospects

    OpenAIRE

    Gaia Collaboration; van Leeuwen, F.; Vallenari, A.; Jordi, C.; Lindegren, L.; Bastian, U.; Prusti, T.; de Bruijne, J. H. J.; Brown, A. G. A.; Babusiaux, C.; Bailer-Jones, C. A. L.; Biermann, M.; Evans, D. W.; Eyer, L.; Jansen, F.

    2017-01-01

    Context. Parallaxes for 331 classical Cepheids, 31 Type II Cepheids, and 364 RR Lyrae stars in common between Gaia and the Hipparcos and Tycho-2 catalogues are published in Gaia Data Release 1 (DR1) as part of the Tycho-Gaia Astrometric Solution (TGAS). \\ud Aims. In order to test these first parallax measurements of the primary standard candles of the cosmological distance ladder, which involve astrometry collected by Gaia during the initial 14 months of science operation, we compared them wi...

  13. THE BHB STARS IN THE SURVEY FIELDS OF RODGERS ET AL. (1993): NEW OBSERVATIONS AND COMPARISONS WITH OTHER RECENT SURVEYS

    International Nuclear Information System (INIS)

    Kinman, T. D.; Brown, Warren R.

    2011-01-01

    We study blue horizontal branch (BHB) and RR Lyrae stars in the Rodgers et al. fields and compare their velocity and density distributions with other surveys in the same part of the sky. Photometric data are given for 176 early-type stars in the northern field. We identify fourteen BHB stars and four possible BHB stars, and determine the selection efficiency of the Century survey, the HK survey, and the SDSS survey for BHB stars. We give light curves and γ radial velocities for three type ab RR Lyrae stars in the northern field; comparison with the nearby LONEOS survey shows that there is likely to be an equal number of lower-amplitude type ab RR Lyrae stars that we do not find. There are therefore at least twice as many BHB stars as type ab RR Lyrae stars in the northern field-similar to the ratio in the solar neighborhood. The velocity distribution of the southern field shows no evidence for an anomalous thick disk that was found by Gilmore et al.; the halo velocity peaks at a slightly prograde rotational velocity but there is also a significant retrograde halo component in this field. The velocity distribution in the northern field shows no evidence of Galactic rotation for |Z| ≥ 4 kpc and a slight prograde motion for |Z| < 4 kpc. The space densities of BHB stars in the northern field agree with an extrapolation of the power-law distribution recently derived by de Propris et al. For |Z| < 4 kpc, however, we observe an excess of BHB stars compared with this power law. We conclude that these BHB stars mostly belong to a spatially flattened, non-rotating inner halo component of the Milky Way in confirmation of the Kinman et al. analysis of Century survey BHB stars.

  14. The chemical inhomogeneity of omega Centauri

    International Nuclear Information System (INIS)

    Freeman, K.C.; Rodgers, A.W.

    1975-01-01

    Observations of 25 RR Lyrae stars in ω Cen have revealed a diversity in the composition of these stars. The composition spread explains the ill-defined giant branch and the existence of M stars in the cluster. The diversity may be due either to variable amounts of giant-branch mixing or to metal enrichment of protostellar gas during the cluster collapse. Among other consideractions, the uniqueness of ω Cen leads us to prefer the latter hypothesis

  15. Pulsating variables

    International Nuclear Information System (INIS)

    1989-01-01

    The study of stellar pulsations is a major route to the understanding of stellar structure and evolution. At the South African Astronomical Observatory (SAAO) the following stellar pulsation studies were undertaken: rapidly oscillating Ap stars; solar-like oscillations in stars; 8-Scuti type variability in a classical Am star; Beta Cephei variables; a pulsating white dwarf and its companion; RR Lyrae variables and galactic Cepheids. 4 figs

  16. VARIABLE STARS IN LARGE MAGELLANIC CLOUD GLOBULAR CLUSTERS. II. NGC 1786

    International Nuclear Information System (INIS)

    Kuehn, Charles A.; Smith, Horace A.; De Lee, Nathan; Catelan, Márcio; Pritzl, Barton J.; Borissova, Jura

    2012-01-01

    This is the second in a series of papers studying the variable stars in Large Magellanic Cloud globular clusters. The primary goal of this series is to study how RR Lyrae stars in Oosterhoff-intermediate systems compare to their counterparts in Oosterhoff I/II systems. In this paper, we present the results of our new time-series B–V photometric study of the globular cluster NGC 1786. A total of 65 variable stars were identified in our field of view. These variables include 53 RR Lyraes (27 RRab, 18 RRc, and 8 RRd), 3 classical Cepheids, 1 Type II Cepheid, 1 Anomalous Cepheid, 2 eclipsing binaries, 3 Delta Scuti/SX Phoenicis variables, and 2 variables of undetermined type. Photometric parameters for these variables are presented. We present physical properties for some of the RR Lyrae stars, derived from Fourier analysis of their light curves. We discuss several different indicators of Oosterhoff type which indicate that the Oosterhoff classification of NGC 1786 is not as clear cut as what is seen in most globular clusters.

  17. VARIABILITY AND STAR FORMATION IN LEO T, THE LOWEST LUMINOSITY STAR-FORMING GALAXY KNOWN TODAY

    Energy Technology Data Exchange (ETDEWEB)

    Clementini, Gisella; Cignoni, Michele; Ramos, Rodrigo Contreras; Federici, Luciana; Tosi, Monica [INAF, Osservatorio Astronomico di Bologna, I-40127 Bologna (Italy); Ripepi, Vincenzo; Marconi, Marcella; Musella, Ilaria, E-mail: gisella.clementini@oabo.inaf.it, E-mail: rodrigo.contreras@oabo.inaf.it, E-mail: luciana.federici@oabo.inaf.it, E-mail: monica.tosi@oabo.inaf.it, E-mail: michele.cignoni@unibo.it, E-mail: ripepi@na.astro.it, E-mail: marcella@na.astro.it, E-mail: ilaria@na.astro.it [INAF, Osservatorio Astronomico di Capodimonte, I-80131 Napoli (Italy)

    2012-09-10

    We present results from the first combined study of variable stars and star formation history (SFH) of the Milky Way 'ultra-faint' dwarf (UFD) galaxy Leo T, based on F606W and F814W multi-epoch archive observations obtained with the Wide Field Planetary Camera 2 on board the Hubble Space Telescope. We have detected 14 variable stars in the galaxy. They include one fundamental-mode RR Lyrae star and 11 Anomalous Cepheids with periods shorter than 1 day, thus suggesting the occurrence of multiple star formation episodes in this UFD, of which one about 10 Gyr ago produced the RR Lyrae star. A new estimate of the distance to Leo T of 409{sup +29}{sub -27} kpc (distance modulus of 23.06 {+-} 0.15 mag) was derived from the galaxy's RR Lyrae star. Our V, V - I color-magnitude diagram (CMD) of Leo T reaches V {approx} 29 mag and shows features typical of a galaxy in transition between dwarf irregular and dwarf spheroidal types. A quantitative analysis of the SFH, based on the comparison of the observed V, V - I CMD with the expected distribution of stars for different evolutionary scenarios, confirms that Leo T has a complex SFH dominated by two enhanced periods about 1.5 and 9 Gyr ago, respectively. The distribution of stars and gas shows that the galaxy has a fairly asymmetric structure.

  18. The Metallicity Gradient of the Old Galactic Bulge Population

    Science.gov (United States)

    Sans Fuentes, Sara Alejandra; De Ridder, Joris

    Understanding the structure, formation and evolution of the Galactic Bulge requires the proper determination of spatial metallicity gradients in both the radial and vertical directions. RR Lyrae pulsators, known to be excellent distance indicators, may hold the key to determining these gradients. Jurcsik and Kovacs (A&A 312:111, 1996) has shown that RR Lyrae light curves and the phase difference of their Fourier decomposition, ϕ 31, can be used to estimate photometric metallicities. The existence of galactic bulge metallicity gradients is a currently debated topic that would help pinpoint the Galaxy's formation and evolution. A recent study of the OGLE-III Galactic Bulge RR Lyrae Population by Pietrukowicz et al. (ApJ 750:169, 2012) suggests that the spatial distribution is uniform. We investigate how small a gradient would be detectable within the current S/N levels of the present data set, given the random and systematic errors associated with the derivation of a photometric metallicity versus spatial position relationship.

  19. Testing slim-disk models on the thermal spectra of LMC X-3

    Czech Academy of Sciences Publication Activity Database

    Straub, O.; Bursa, Michal; Sądowski, A.; Steiner, J.F.; Abramowicz, M. A.; Kluzniak, W.; McClintock, J.E.; Narayan, R.; Remillard, R.A.

    2011-01-01

    Roč. 533, September (2011), A67/1-A67/6 ISSN 0004-6361 R&D Projects: GA MŠk(CZ) LC06014; GA MŠk ME09036 Institutional research plan: CEZ:AV0Z10030501 Keywords : accretion * accretion disks * black hole physics Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.587, year: 2011

  20. Superorbital Period Variations in the X-ray Pulsar LMC X-4 B. Paul ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    RXTE-ASM data alone. The second solution requires a period of 30.31 d, close to the value obtained with the RXTE-ASM light curve. The second solution gives large residuals for the GINGA and EXOSAT arrival times. To account for the residuals, we introduced a period derivative and fitted a quadratic function to the arrival ...

  1. MASSIVE STAR FORMATION IN THE LMC. I. N159 AND N160 COMPLEXES

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, Michael S.; Jones, Terry J.; Gehrz, Robert D. [Minnesota Institute for Astrophysics, School of Physics and Astronomy 116 Church St SE, University of Minnesota, Minneapolis, MN 55455 (United States); Helton, L. Andrew [USRA–SOFIA Science Center, NASA Ames Research Center, Moffett Field, CA 94035 (United States)

    2017-01-10

    We present images and spectral energy distributions (SEDs) of massive young stellar objects (YSOs) in three star-forming H ii regions of the Large Magellanic Cloud: N159A, N159 Papillon, and N160. We use photometry from SOFIA/FORCAST at 25.3–37.1 μ m to constrain model fits to the SEDs and determine luminosities, ages, and dust content of the embedded YSOs and their local environments. By placing these sources on mid-infrared color–magnitude and color–color diagrams, we analyze their dust properties and consider their evolutionary status. Since each object in the FORCAST images has an obvious bright near-infrared counterpart in Spitzer Space Telescope images, we do not find any evidence for new, very cool, previously undiscovered Class 0 YSOs. Additionally, based on its mid-infrared colors and model parameters, N159A is younger than N160 and the Papillon. The nature of the first extragalactic protostars in N159, P1, and P2, is also discussed.

  2. A NEW, LOW BRAKING INDEX FOR THE LMC PULSAR B0540–69

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, F. E.; Harding, A. K. [Astrophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Guillemot, L. [Laboratoire de Physique et Chimie de l’Environnement et de l’Espace (LPC2E), CNRS-Université d’Orléans, F-45071 Orléans (France); Martin, P. [Institut de Recherche en Astrophysique et Planétologie, UPS/CNRS, UMR5277, F-31028 Toulouse Cedex 4 (France); Smith, D. A., E-mail: frank.marshall@nasa.gov [Centre d’Études Nucléaires de Bordeaux Gradignan, IN2P3/CNRS, Université de Bordeaux 1, BP120, F-33175, Gradignan Cedex (France)

    2016-08-20

    We report the results of a 16 month monitoring campaign using the Swift satellite of PSR B0540–69, a young pulsar in the Large Magellanic Cloud. Phase connection was maintained throughout the campaign so that a reliable ephemeris could be determined, and the length of the campaign is adequate to accurately determine the spin frequency ν and its first and second derivatives. The braking index n is 0.031 ± 0.013 (90% confidence), a value much lower than previously reported for B0540–69 and almost all other young pulsars. We use data from the extensive monitoring campaign with Rossi X-ray Timing Explorer to show that timing noise is unlikely to significantly affect the measurement. This is the first measurement of the braking index in the pulsar's recently discovered high spin-down state. We discuss possible mechanisms for producing the low braking index.

  3. VizieR Online Data Catalog: LMC OGLE-III Shallow Survey variable stars (Ulaczyk+, 2013)

    Science.gov (United States)

    Ulaczyk, K.; Szymanski, M. K.; Udalski, A.; Kubiak, M.; Pietrzynski, G.; Soszynski, I.; Wyrzykowski, L.; Poleski, R.; Gieren, W.; Walker, A. R.; Garcia-Varela, A.

    2017-07-01

    Photometric data were collected using the 1.3-m Warsaw Telescope located at Las Campanas Observatory, operated by the Carnegie Institution for Science. We used exactly the same photometric system as in the OGLE-III main survey. Detailed information about whole instrumentation can be found in Udalski (2003AcA....53..291U). (5 data files).

  4. VizieR Online Data Catalog: Variable stars in LMC MACHO fields 1 & 79 (Szulagyi+, 2009)

    Science.gov (United States)

    Szulagyi, J.; Kovacs, G.; Welch, D. L.

    2009-06-01

    Tables 1 and 2 give the brief summary of the variables found in the course of the analysis. Main properties are listed and preliminary classifications are given (this latter is ambiguous in some cases, as indicated by question marks). Time series (original, published by the MACHO project and TFA-filtered) can be accessed at: http://www.konkoly.hu/staff/kovacs/macho_tfa/ (2 data files).

  5. VizieR Online Data Catalog: Integrated spectroscopy of 6 LMC clusters (Minniti+, 2014)

    Science.gov (United States)

    Minniti, J. H.; Ahumada, A. V.; Claria, J. J.; Benitez-Llambay, A.

    2014-03-01

    The observations were carried out with the Jorge Sahade 2.15m telescope at Complejo Astronomico El Leoncito (CASLEO, San Juan Argentina) during eight nights in December 2009 and 2012. We employed the REOSC spectrograph (simple mode). The slit was set in the East-West direction, and the observations were performed by scanning the slit across the objects in the North-South direction. We used a grating of 300 grooves/mm, which produces an average dispersion in the observed region of ~140Å/mm (3.46Å/pix). The useful spectral coverage was λ=3700-6800Å. Here we present the integrated spectra for the six SCs, corrected by radial velocity, and the new created template. (2 data files).

  6. Detection of a very bright source close to the LMC supernova SN 1987A

    Science.gov (United States)

    Nisenson, P.; Papaliolios, C.; Karovska, M.; Noyes, R.

    1987-01-01

    High angular resolution observations of the supernova in the Large Magellanic Cloud, SN 1987A, have revealed a bright source separated from the SN by approximately 60 mas with a magnitude difference of 2.7 at 656 nm (H-alpha). Speckle imaging techniques were applied to data recorded with the CfA two-dimensional photon counting detector on the CTIO 4 m telescope on March 25 and April 2 to allow measurements in H-alpha on both nights and at 533 nm and 450 nm on the second night. The nature of this object is as yet unknown, though it is almost certainly a phenomenon related to the SN.

  7. A New, Low Braking Index for the LMC Pulsar B0540-69

    Science.gov (United States)

    Marshall, F. E.; Guillemot, L.; Harding, A. K.; Martin, P.; Smith, D. A.

    2016-01-01

    We report the results of a 16-month monitoring campaign using the Swift satellite of PSR 0540, a young pulsar in the Large Magellanic Cloud. Phase connection was maintained throughout the campaign so that a reliable ephemeris could be determined, and the length of the campaign is adequate to accurately determine the spin frequency and its first and second derivatives. The braking index n is 0.031 +/- 0.013 (90% confidence), a value much lower than previously reported for 0 540 and almost all other young pulsars. We use data from the extensive monitoring campaign with RXTE to showt hat timing noise is unlikely to significantly affect the measurement. This is the first measurement of the braking index in the pulsars recently discovered high spin-down state. We discuss possible mechanisms for producing the low braking index.

  8. FASHIONABLY LATE? BUILDING UP THE MILKY WAY'S INNER HALO

    International Nuclear Information System (INIS)

    Morrison, Heather L.; Harding, Paul; Helmi, Amina

    2009-01-01

    Using a sample of 246 metal-poor stars (RR Lyraes, red giants, and red horizontal branch stars) which is remarkable for the accuracy of its six-dimensional kinematical data, we find, by examining the distribution of stellar orbital angular momenta, a new component for the local halo which has an axial ratio c/a ∼ 0.2, a similar flattening to the thick disk. It has a small prograde rotation but is supported by velocity anisotropy, and contains more intermediate-metallicity stars (with -1.5 < [Fe/H] < -1.0) than the rest of our sample. We suggest that this component was formed quite late, during or after the formation of the disk. It formed either from the gas that was accreted by the last major mergers experienced by the Galaxy, or by dynamical friction of massive infalling satellite(s) with the halo and possibly the stellar disk or thick disk. The remainder of the halo stars in our sample, which are less closely confined to the disk plane, exhibit a clumpy distribution in energy and angular momentum, suggesting that the early, chaotic conditions under which the inner halo formed were not violent enough to erase the record of their origins. The clumpy structure suggests that a relatively small number of progenitors were responsible for building up the inner halo, in line with theoretical expectations. We find a difference in mean binding energy between the RR Lyrae variables and the red giants in our sample, suggesting that more of the RR Lyraes in the sample belong to the outer halo, and that the outer halo may be somewhat younger, as first suggested by Searle and Zinn. We also find that the RR Lyrae mean rotation is more negative than the red giants, which is consistent with the recent result of Carollo et al. that the outer halo has a retrograde rotation and with the difference in kinematics seen between RR Lyraes and blue horizontal branch stars by Kinman et al. (2007).

  9. The continuous UV flux of alpha lyrae: NON-LTE results

    International Nuclear Information System (INIS)

    Snijders, M.A.J.

    1977-01-01

    Non--LTE calculations for the ultraviolet C I and Si I continuous opacity show that LTE results overestimate the importance of these sources of opacity and underestimate the emergent flux in α Lyr. The largest errors occur between 1100 and 1160 A where the predicted flux in non--LTE is as much as 50 times larger than in LTE, in reasonable accord with Copernicus observations.The discrepancy between LTE models and observations has been interpreted by Praderie et al. to result from the existence of a chromosphere. Until a self--consistent non-LTE model atmosphere becomes available, such an interpretation is premature

  10. The continuous UV flux of Alpha Lyrae - Non-LTE results

    Science.gov (United States)

    Snijders, M. A. J.

    1977-01-01

    Non-LTE calculations for the ultraviolet C I and Si I continuous opacity show that LTE results overestimate the importance of these sources of opacity and underestimate the emergent flux in Alpha Lyr. The largest errors occur between 1100 and 1160 A, where the predicted flux in non-LTE is as much as 50 times larger than in LTE, in reasonable accord with Copernicus observations. The discrepancy between LTE models and observations has been interpreted to result from the existence of a chromosphere. Until a self-consistent non-LTE model atmosphere becomes available, such an interpretation is premature.

  11. CCD photometry in the Vilnius photometric systems. II. Analysis of a region in Lyra

    International Nuclear Information System (INIS)

    Smriglio, F.; Dasgupta, A.K.; Boyle, R.P.; Straizys, V.; Janulis, R.

    1991-01-01

    Two-dimensional classification of 216 stars down to 17 mag based on their seven color photoelectric and CCD photometry in the Vilnius system is presented. Except for normal stars, several subdwarfs, metal-deficient giants, and stars of other peculiarities are suspected. Interstellar extinction is determined for normal stars in two areas north and south of globular cluster M56, as well as for a 1 square degree area around M56. The mean value of A v outside the galactic dust layer is ∼ 0.75 mag

  12. CCD photometry in the Vilnius photometric systems. II. Analysis of a region in Lyra

    Energy Technology Data Exchange (ETDEWEB)

    Smriglio, F.; Dasgupta, A.K. (Rome Univ. (IT). Ist. Astronomico); Nandy, K. (Royal Observatory, Edinburgh (UK)); Boyle, R.P. (Vatican Observatory, Rome (IT)); Straizys, V.; Janulis, R. (AN Litovskoj SSR, Vilnius (SU). Inst. Fiziki)

    1991-04-01

    Two-dimensional classification of 216 stars down to 17 mag based on their seven color photoelectric and CCD photometry in the Vilnius system is presented. Except for normal stars, several subdwarfs, metal-deficient giants, and stars of other peculiarities are suspected. Interstellar extinction is determined for normal stars in two areas north and south of globular cluster M56, as well as for a 1 square degree area around M56. The mean value of A{sub v} outside the galactic dust layer is {similar to} 0.75 mag.

  13. Bianchi Type-I cosmological mesonic stiff fluid models in Lyra's ...

    Indian Academy of Sciences (India)

    Some physical and kinematical properties of the models are also discussed. Keywords. Cosmology; Bianchi-I ... Here ρ, p and ui are respectively the energy density, equilibrium pressure and four-velocity vector of the .... In order to obtain an explicit form of physical parameters, we consider here stiff fluid distribution given by ...

  14. VARIABLE STARS IN THE ULTRA-FAINT DWARF SPHEROIDAL GALAXY URSA MAJOR I

    Energy Technology Data Exchange (ETDEWEB)

    Garofalo, Alessia; Moretti, Maria Ida [Dipartimento di Astronomia, Universita di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); Cusano, Felice; Clementini, Gisella [INAF-Osservatorio Astronomico di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); Ripepi, Vincenzo; Dall' Ora, Massimo; Coppola, Giuseppina; Musella, Ilaria; Marconi, Marcella, E-mail: alessia.garofalo@studio.unibo.it, E-mail: fcusano@na.astro.it, E-mail: gisella.clementini@oabo.inaf.it, E-mail: ripepi@na.astro.it, E-mail: dallora@na.astro.it, E-mail: imoretti@na.astro.it, E-mail: coppola@na.astro.it, E-mail: ilaria@na.astro.it, E-mail: marcella@na.astro.it [INAF-Osservatorio Astronomico di Capodimonte, Salita Moiariello 16, I-80131 Napoli (Italy)

    2013-04-10

    We have performed the first study of the variable star population of Ursa Major I (UMa I), an ultra-faint dwarf satellite recently discovered around the Milky Way (MW) by the Sloan Digital Sky Survey. Combining time series observations in the B and V bands from four different telescopes, we have identified seven RR Lyrae stars in UMa I, of which five are fundamental-mode (RRab) and two are first-overtone pulsators (RRc). Our V, B - V color-magnitude diagram of UMa I reaches V {approx} 23 mag (at a signal-to-noise ratio of {approx}6) and shows features typical of a single old stellar population. The mean pulsation period of the RRab stars (P{sub ab}) = 0.628, {sigma} = 0.071 days (or (P{sub ab}) = 0.599, {sigma} = 0.032 days, if V4, the longest period and brightest variable, is discarded) and the position on the period-amplitude diagram suggest an Oosterhoff-intermediate classification for the galaxy. The RR Lyrae stars trace the galaxy horizontal branch (HB) at an average apparent magnitude of (V(RR)) = 20.43 {+-} 0.02 mag (average on six stars and discarding V4), giving in turn a distance modulus for UMa I of (m - M){sub 0} = 19.94 {+-} 0.13 mag, distance d = 97.3{sup +6.0}{sub -5.7} kpc, in the scale where the distance modulus of the Large Magellanic Cloud is 18.5 {+-} 0.1 mag. Isodensity contours of UMa I red giants and HB stars (including the RR Lyrae stars identified in this study) show that the galaxy has an S-shaped structure, which is likely caused by the tidal interaction with the MW. Photometric metallicities were derived for six of the UMa I RR Lyrae stars from the parameters of the Fourier decomposition of the V-band light curves, leading to an average metal abundance of [Fe/H] = -2.29 dex ({sigma} = 0.06 dex, average on six stars) on the Carretta et al. metallicity scale.

  15. Variable stars in the VVV globular clusters. I. 2MASS-GC 02 and Terzan 10

    Energy Technology Data Exchange (ETDEWEB)

    Alonso-García, Javier; Dékány, István; Catelan, Márcio; Ramos, Rodrigo Contreras; Gran, Felipe; Leyton, Paul; Minniti, Dante [Instituto de Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, 782-0436 Macul, Santiago (Chile); Amigo, Pía, E-mail: jalonso@astro.puc.cl, E-mail: idekany@astro.puc.cl, E-mail: mcatelan@astro.puc.cl, E-mail: rcontrer@astro.puc.cl, E-mail: fgran@astro.puc.cl, E-mail: pia.amigo@uv.cl, E-mail: pleyton@astro.puc.cl, E-mail: dante@astrofisica.cl [Millennium Institute of Astrophysics, Av. Vicuña Mackenna 4860, 782-0436 Macul, Santiago (Chile)

    2015-03-01

    The VISTA Variables in the Vía Láctea (VVV) ESO Public Survey is opening a new window to study inner Galactic globular clusters (GCs) using their variable stars. These GCs have been neglected in the past due to the difficulties caused by the presence of elevated extinction and high field stellar densities in their lines of sight. However, the discovery and study of any present variables in these clusters, especially RR Lyrae stars, can help to greatly improve the accuracy of their physical parameters. It can also help to shed some light on the questions raised by the intriguing Oosterhoff dichotomy in the Galactic GC system. In a series of papers we plan to explore variable stars in the GCs falling inside the field of the VVV survey. In this first paper, we search for and study the variables present in two highly reddened, moderately metal-poor, faint, inner Galactic GCs: 2MASS-GC 02 and Terzan 10. We report the discovery of sizable populations of RR Lyrae stars in both GCs. We use near-infrared period–luminosity relations to determine the color excess of each RR Lyrae star, from which we obtain both accurate distances to the GCs and the ratios of the selective-to-total extinction in their directions. We find the extinction toward both clusters to be elevated, non-standard, and highly differential. We also find both clusters to be closer to the Galactic center than previously thought, with Terzan 10 being on the far side of the Galactic bulge. Finally, we discuss their Oosterhoff properties, and conclude that both clusters stand out from the dichotomy followed by most Galactic GCs.

  16. The Carnegie-Chicago Hubble Program. I. An Independent Approach to the Extragalactic Distance Scale Using Only Population II Distance Indicators

    Science.gov (United States)

    Beaton, Rachael L.; Freedman, Wendy L.; Madore, Barry F.; Bono, Giuseppe; Carlson, Erika K.; Clementini, Gisella; Durbin, Meredith J.; Garofalo, Alessia; Hatt, Dylan; Jang, In Sung; Kollmeier, Juna A.; Lee, Myung Gyoon; Monson, Andrew J.; Rich, Jeffrey A.; Scowcroft, Victoria; Seibert, Mark; Sturch, Laura; Yang, Soung-Chul

    2016-12-01

    We present an overview of the Carnegie-Chicago Hubble Program, an ongoing program to obtain a 3% measurement of the Hubble constant (H 0) using alternative methods to the traditional Cepheid distance scale. We aim to establish a completely independent route to H 0 using RR Lyrae variables, the tip of the red giant branch (TRGB), and Type Ia supernovae (SNe Ia). This alternative distance ladder can be applied to galaxies of any Hubble type, of any inclination, and, using old stars in low-density environments, is robust to the degenerate effects of metallicity and interstellar extinction. Given the relatively small number of SNe Ia host galaxies with independently measured distances, these properties provide a great systematic advantage in the measurement of H 0 via the distance ladder. Initially, the accuracy of our value of H 0 will be set by the five Galactic RR Lyrae calibrators with Hubble Space Telescope Fine-Guidance Sensor parallaxes. With Gaia, both the RR Lyrae zero-point and TRGB method will be independently calibrated, the former with at least an order of magnitude more calibrators and the latter directly through parallax measurement of tip red giants. As the first end-to-end “distance ladder” completely independent of both Cepheid variables and the Large Magellanic Cloud, this path to H 0 will allow for the high-precision comparison at each rung of the traditional distance ladder that is necessary to understand tensions between this and other routes to H 0. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs #13472 and #13691.

  17. Variable Stars in Large Magellanic Cloud Globular Clusters. II. NGC 1786

    Science.gov (United States)

    Kuehn, Charles A.; Smith, Horace A.; Catelan, Márcio; Pritzl, Barton J.; De Lee, Nathan; Borissova, Jura

    2012-12-01

    This is the second in a series of papers studying the variable stars in Large Magellanic Cloud globular clusters. The primary goal of this series is to study how RR Lyrae stars in Oosterhoff-intermediate systems compare to their counterparts in Oosterhoff I/II systems. In this paper, we present the results of our new time-series B-V photometric study of the globular cluster NGC 1786. A total of 65 variable stars were identified in our field of view. These variables include 53 RR Lyraes (27 RRab, 18 RRc, and 8 RRd), 3 classical Cepheids, 1 Type II Cepheid, 1 Anomalous Cepheid, 2 eclipsing binaries, 3 Delta Scuti/SX Phoenicis variables, and 2 variables of undetermined type. Photometric parameters for these variables are presented. We present physical properties for some of the RR Lyrae stars, derived from Fourier analysis of their light curves. We discuss several different indicators of Oosterhoff type which indicate that the Oosterhoff classification of NGC 1786 is not as clear cut as what is seen in most globular clusters. Based on observations taken with the SMARTS 1.3 m telescope operated by the SMARTS Consortium and observations taken at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia, e Inovação (MCTI) da República Federativa do Brasil, the U.S. National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU).

  18. R.R. Wilson prize lecture: Adventures with accelerators

    International Nuclear Information System (INIS)

    Blewett, J.P.

    1993-01-01

    This paper is a very concise history of the authors experiences with particle accelerators, spanning his first experiences as a graduate student, through his professional career. His first experiences were visiting labs in Washington DC, and seeing equipment delivered to his school so large walls had to be moved for access. He saw larger machines in England, and was at GE when early betatrons were built, and when the first functional synchrotron was built

  19. Query Storage and Relay in Research Root (LACREND RR)

    Science.gov (United States)

    2017-05-30

    evaluated that our configuration management software in Puppet needed major revision. We decided to switch tools as part of this process to ansible, a more...packet collection software we developed; also the prior project funding the work: Los Angeles Network Data Exchange and Approved for Public Release...system that allows manipulation and replay of DNS data for experimental purposes. 15. SUBJECT TERMS DNS, datasets, network security research 16

  20. Thermo-Mechanical Fatigue Crack Growth of RR1000

    OpenAIRE

    Christopher John Pretty; Mark Thomas Whitaker; Steve John Williams

    2017-01-01

    Non-isothermal conditions during flight cycles have long led to the requirement for thermo-mechanical fatigue (TMF) evaluation of aerospace materials. However, the increased temperatures within the gas turbine engine have meant that the requirements for TMF testing now extend to disc alloys along with blade materials. As such, fatigue crack growth rates are required to be evaluated under non-isothermal conditions along with the development of a detailed understanding of related failure mechan...

  1. Environmental Control for Regional Library Facilities. RR-80-3.

    Science.gov (United States)

    King, Richard G., Jr.

    This report presents an overview of the damage to library materials caused by uncontrollable environmental variables. The control of atmospheric pollutants, temperature, and humidity are discussed with regard to damage, standards, and the costs of deterioration due to these factors. Twelve references are listed. (FM)

  2. Thirty years experience in ET-RR-1 operation

    International Nuclear Information System (INIS)

    Khattab, M.

    1993-01-01

    Egypt research reactor (ET-R R-1) got critical in 27 Th. July 1961. Since that time many technical problems in system manipulation were raised. The present paper demonstrates the famous events that were initiated and the procedures that were taken for their recovery or mitigation. Maintenance problems are discussed. Reactor parameters measuring systems and control have been modernized. The reactor is investigated by in-service inspection program, (ISI). The results show that reactor vessels surface conditions are in good status. experience obtained from these activities and some proposals for future development are summarized. 6 figs., 1 tab

  3. PSQM-based RR and NR video quality metrics

    Science.gov (United States)

    Lu, Zhongkang; Lin, Weisi; Ong, Eeping; Yang, Xiaokang; Yao, Susu

    2003-06-01

    This paper presents a new and general concept, PQSM (Perceptual Quality Significance Map), to be used in measuring the visual distortion. It makes use of the selectivity characteristic of HVS (Human Visual System) that it pays more attention to certain area/regions of visual signal due to one or more of the following factors: salient features in image/video, cues from domain knowledge, and association of other media (e.g., speech or audio). PQSM is an array whose elements represent the relative perceptual-quality significance levels for the corresponding area/regions for images or video. Due to its generality, PQSM can be incorporated into any visual distortion metrics: to improve effectiveness or/and efficiency of perceptual metrics; or even to enhance a PSNR-based metric. A three-stage PQSM estimation method is also proposed in this paper, with an implementation of motion, texture, luminance, skin-color and face mapping. Experimental results show the scheme can improve the performance of current image/video distortion metrics.

  4. Ridgefield Complex - Invasive Plant ED/RR Search 2015

    Data.gov (United States)

    Department of the Interior — The proposed project is a part of the Gorge NWRs’ invasives management program and will help achieve goals and improve targeted habitats identified in the Refuges’...

  5. Ages of Globular Clusters from HIPPARCOS Parallaxes of Local Subdwarfs

    Science.gov (United States)

    Gratton, Raffaele G.; Fusi Pecci, Flavio; Carretta, Eugenio; Clementini, Gisella; Corsi, Carlo E.; Lattanzi, Mario

    1997-12-01

    ) analysis of RR Lyrae stars by Fernley and Clementini et al., while it is somewhat shallower than the relation given by Sandage. The zero-point is 0.2 to 0.3 mag brighter than that obtained with BW, while it agrees fairly well with that given by Sandage. A comparison with alternative relationships is briefly discussed. 4. The corresponding LMC distance modulus is (m - M)0 = 18.60 +/- 0.07, in good agreement with the recent values of 18.70 +/- 0.10 and 18.54 +/- 0.2 derived by Feast & Catchpole and van Leeuwen et al., respectively, from HIPPARCOS parallaxes of Galactic Cepheid and Mira variables. 5. The age of the bona fide old globular clusters (Oosterhoff II and BHB), based on the absolute magnitude of the turnoff (a theoretically robust indicator) is Age=11.8+2.1-2.5 Gyr , where the error bar is the 95% confidence range. The rms scatter of individual ages around the mean value is ~10%, in agreement with expectations from observational errors alone (that is, we do not find it necessary to introduce a real age scatter among these clusters). A reliable study of the relative ages requires the use of age indicators better suited to this purpose and data for a larger sample of GGCs. 6. Allowing for a minimum delay of 0.5 Gyr from the birth of the universe until the formation of globular clusters, our age estimate is compatible with an Einstein-de Sitter model if H0 confidence range of most determinations of H0, we conclude that the present age of globular clusters does not conflict with standard inflationary models of the universe. Based on data from the HIPPARCOS astrometry satellite and from Asiago and McDonald Observatories.

  6. Flavours of variability

    DEFF Research Database (Denmark)

    Benkö, J.M.; Kolenberg, Katrien; Szabó, R.

    2010-01-01

    frequencies beyond the well-known harmonics and Blazhko multiplets have been found. These frequencies are located around the half-integer multiples of the main pulsation frequency for at least three stars. In four stars, these frequencies are close to the first and/or second overtone modes. The amplitudes...... of these periodicities seem to vary over the Blazhko cycle. V350 Lyr, a non-Blazhko star in our sample, is the first example of a double-mode RR Lyrae star that pulsates in its fundamental and second overtone modes....

  7. Variable star research at Los Alamos

    International Nuclear Information System (INIS)

    Davis, C.G.; Cox, A.N.; Adams, T.F.

    1978-01-01

    Three major areas of variable star research at Los Alamos are carried out: (1) a study using improved Cepheid light curves in order to define more precisely the Hertzsprung sequence, in collaboration with John Castor and John Cox; (2) the suggestion by A. Cox that helium enrichment occurs in the stellar envelope, by a stellar wind, which may explain many of the mass anomalies, this work being with G. Michaud, D. King, R. Deupree, and S. Hodson; and (3) the study of Cepheid and RR Lyrae colors to compare directly to the observations. A brief discussion of the present status of each of these research programs will be given. 25 references

  8. Z CVn - Still mysterious

    Science.gov (United States)

    Skarka, M.; Liška, J.; Dřevěný, R.; Sódor, Á.; Barnes, T.; Kolenberg, K.

    2018-04-01

    We comment on short- and long-term pulsation period variations of Z CVn, a classical RR Lyrae star with the Blazhko effect. Z CVn shows cyclic-like O-C diagram that can be interpreted as a consequence of binarity throught the light travel time effect. We show that this hypothesis is false and that the observed long-term period variations must be caused by some effect that is intrinsic to the star. We also show that the Blazhko period is not simply anti-correlated with the long-term period variations as was suggested by previous authors.

  9. Is there a composition gradient in the halo

    International Nuclear Information System (INIS)

    Kraft, R.P.; Trefzger, C.F.; Suntzeff, N.

    1979-01-01

    In the inner halo (galactocentric distance R < approximately 8 kpc), the Basel RGU photometry should allow the derivation of the shapes and dimensions of the iso-abundance contours. For the outer halo to R approximately 30 kpc, the authors review techniques based on Δs-measurements of RR Lyraes (Lick) and intermediate band-pass photometry of globular-cluster giants (Searle and Zinn, Palomar). Both methods suggest little change in mean [Fe/H] between 10 and 30 kpc; however, both may be biased against the discovery of very metal-poor objects. The conclusion that the outer halo has no abundance gradient may be somewhat premature. (Auth.)

  10. VizieR Online Data Catalog: NIR polarimetric study in the LMC N159/N160 field (Kim+, 2017)

    Science.gov (United States)

    Kim, J.; Jeong, W.-S.; Pyo, J.; Pak, S.; Park, W.-K.; Kwon, J.; Tamura, M.

    2018-04-01

    Simultaneous JHKs polarimetric observations of the N159/N160 c were performed on 2007 February 3 and 5. We used the near-infrared camera SIRIUS (Nagayama et al. 2003SPIE.4841..459N) and the polarimeter SIRPOL (Kandori et al. 2006SPIE.6269E..51K) of the Infrared Survey Facility (IRSF) 1.4 m telescope at the South African Astronomical Observatory in Sutherland, South Africa. The camera has a field of view of 7.7"x7.7" and a pixel scale of 0.45"/pixel. One set of observations for a target field consisted of 20 s exposures at 10 dithered positions for four wave-plate angles (0°, 45°, 22.5°, and 67.5°) in the J, H, and Ks bands, and the whole sequence is repeated 10 and 9 times for the N159 and N160 fields centered at (α, δ)2000=(5h39m37.1s, -69°43'45.1") and (5h40m05.6s, -69°36'25.8"), respectively. (2 data files).

  11. Masha - Lilleaida uus nägu / Lylian Meister

    Index Scriptorium Estoniae

    Meister, Lylian, 1966-

    2007-01-01

    Tallinna lillesalongi Masha sisekujundus. Kujundamisel oli omanikele abiks sisekujundaja Kristina Lõuk. Ühe omaniku, florist Ahty Lyra kodus rõdu lillekastis kasvavatest lilledest. A. Lyra kommentaarid

  12. Age of M92 and M15

    International Nuclear Information System (INIS)

    Sandage, A.

    1983-01-01

    Comparison of VandenBerg's isochrones for globular clusters with the photometry of many main-sequence stars in M92 and M15 gives an age of T = 18 +- 2 x 10 9 years for both clusters, using a vertical fit to the turn-off luminosity, together with distance modulii found from the period-color-luminosity relation of their RR Lyrae stars. Comparison of the systematics of the composite CM diagram for clusters of different metallicity with that predicted from VandenBerg's isochrones, all for T = 18 x 10 9 years, shows good agreement. Justification of the adopted zero-point value of M/sub v/ (RR,M92) = +0.63 is made by comparing the main sequences of M92, M3, and M5 with that defined by 11 field subdwarfs whose metallicities lie between [Fe/H] of -2.2 and -1.2 for which adequate astrometric distances exist

  13. Method of LSD profile asymmetry for estimating the center of mass velocities of pulsating stars

    Science.gov (United States)

    Britavskiy, N.; Pancino, E.; Tsymbal, V.; Romano, D.; Cacciari, C.; Clementini, C.

    2016-05-01

    We present radial velocity analysis for 20 solar neighborhood RR Lyrae and 3 Population II Cepheids. High-resolution spectra were observed with either TNG/SARG or VLT/UVES over varying phases. To estimate the center of mass (barycentric) velocities of the program stars, we utilized two independent methods. First, the 'classic' method was employed, which is based on RR Lyrae radial velocity curve templates. Second, we provide the new method that used absorption line profile asymmetry to determine both the pulsation and the barycentric velocities even with a low number of high-resolution spectra and in cases where the phase of the observations is uncertain. This new method is based on a least squares deconvolution (LSD) of the line profiles in order to an- alyze line asymmetry that occurs in the spectra of pulsating stars. By applying this method to our sample stars we attain accurate measurements (+- 2 kms^-1) of the pulsation component of the radial velocity. This results in determination of the barycentric velocity to within 5 kms^-1 even with a low number of high- resolution spectra. A detailed investigation of LSD profile asymmetry shows the variable nature of the project factor at different pulsation phases, which should be taken into account in the detailed spectroscopic analysis of pulsating stars.

  14. A Look at the Milky Way's Outskirts

    Science.gov (United States)

    Kohler, Susanna

    2017-11-01

    Studying the large-scale structure of the Milky Way is difficult given that were stuck in its interior which means we cant step back for a broad overview of our home. Instead, a recent study uses distant variable stars to map out a picture of whats happening in the outskirts of our galaxy.Mapping with TracersPhase-folded light curve for two of the RR Lyrae stars in the authors sample, each with hundreds of observations over 7 years. [Cohen et al. 2017]Since observing the Milky Way from the outside isnt an option, we have to take creative approaches to mapping its outer regions and measuring its total mass and dark matter content. One tool used by astronomers is tracers: easily identifiable stars that can be treated as massless markers moving only as a result of the galactic potential. Mapping the locations and motions of tracers allows us to measure the larger properties of the galaxy.RR Lyrae stars are low-mass, variable stars that make especially good tracers. They pulsate predictably on timescales of less than a day, creating distinctive light curves that can easily be distinguished and tracked in wide-field optical imaging surveys over long periods of time. Their brightness makes them detectable out to large distances, and their blue color helps to separate them from contaminating stars in the foreground.Best of all, RR Lyrae stars are very nearly standard candles: their distances can be determined precisely with only knowledge of their measured light curves.Locations on the sky of the several hundred outer-halo RR Lyrae stars in the authors original sample. The red curve shows the location of the Sagittarius stream, an ordered structure the authors avoided so as to only have unassociated stars in their sample. [Cohen et al. 2017]Distant VariablesIn a new study led by Judith Cohen (California Institute of Technology), the signals of hundreds of distant RR Lyrae stars were identified in observations of transient objects made with the Palomar Transient Factory

  15. Spectroscopic follow-up of the Hercules-Aquila Cloud

    Science.gov (United States)

    Simion, Iulia T.; Belokurov, Vasily; Koposov, Sergey E.; Sheffield, Allyson; Johnston, Kathryn V.

    2018-05-01

    We designed a follow-up program to find the spectroscopic properties of the Hercules-Aquila Cloud (HAC) and test scenarios for its formation. We measured the radial velocities (RVs) of 45 RR Lyrae in the southern portion of the HAC using the facilities at the MDM observatory, producing the first large sample of velocities in the HAC. We found a double-peaked distribution in RVs, skewed slightly to negative velocities. We compared both the morphology of HAC projected on to the plane of the sky and the distribution of velocities in this structure outlined by RR Lyrae and other tracer populations at different distances to N-body simulations. We found that the behaviour is characteristic of an old, well-mixed accretion event with small apo-galactic radius. We cannot yet rule out other formation mechanisms for the HAC. However, if our interpretation is correct, HAC represents just a small portion of a much larger debris structure spread throughout the inner Galaxy whose distinct kinematic structure should be apparent in RV studies along many lines of sight.

  16. Constraints on helium enhancement in the globular cluster M4 (NGC 6121): The horizontal branch test

    Energy Technology Data Exchange (ETDEWEB)

    Valcarce, A. A. R.; De Medeiros, J. R. [Universidade Federal do Rio Grande do Norte, Departamento de Física, 59072-970 Natal, RN (Brazil); Catelan, M. [Pontificia Universidad Católica de Chile, Centro de Astroingeniería, Av. Vicuña Mackena 4860, 782-0436 Macul, Santiago (Chile); Alonso-García, J. [Pontificia Universidad Católica de Chile, Instituto de Astrofísica, Facultad de Física, Av. Vicuña Mackena 4860, 782-0436 Macul, Santiago (Chile); Cortés, C. [Universidad Metropolitana de Ciencias de la Educación, Facultad de Ciencias Básicas, Departamento de Física, Av. José Pedro Alessandri 774, Santiago (Chile)

    2014-02-20

    Recent pieces of evidence have revealed that most, and possibly all, globular star clusters are composed of groups of stars that formed in multiple episodes with different chemical compositions. In this sense, it has also been argued that variations in the initial helium abundance (Y) from one population to the next are also the rule, rather than the exception. In the case of the metal-intermediate globular cluster M4 (NGC 6121), recent high-resolution spectroscopic observations of blue horizontal branch (HB) stars (i.e., HB stars hotter than the RR Lyrae instability strip) suggest that a large fraction of blue HB stars are second-generation stars formed with high helium abundances. In this paper, we test this scenario by using recent photometric and spectroscopic data together with theoretical evolutionary computations for different Y values. Comparing the photometric data with the theoretically derived color-magnitude diagrams, we find that the bulk of the blue HB stars in M4 have ΔY ≲ 0.01 with respect to the cluster's red HB stars (i.e., HB stars cooler than the RR Lyrae strip)—a result which is corroborated by comparison with spectroscopically derived gravities and temperatures, which also favor little He enhancement. However, the possible existence of a minority population on the blue HB of the cluster with a significant He enhancement level is also discussed.

  17. Variable Stars in Large Magellanic Cloud Globular Clusters. III. Reticulum

    Science.gov (United States)

    Kuehn, Charles A.; Dame, Kyra; Smith, Horace A.; Catelan, Márcio; Jeon, Young-Beom; Nemec, James M.; Walker, Alistair R.; Kunder, Andrea; Pritzl, Barton J.; De Lee, Nathan; Borissova, Jura

    2013-06-01

    This is the third in a series of papers studying the variable stars in old globular clusters in the Large Magellanic Cloud. The primary goal of this series is to look at how the characteristics and behavior of RR Lyrae stars in Oosterhoff-intermediate systems compare to those of their counterparts in Oosterhoff-I/II systems. In this paper we present the results of our new time-series BVI photometric study of the globular cluster Reticulum. We found a total of 32 variables stars (22 RRab, 4 RRc, and 6 RRd stars) in our field of view. We present photometric parameters and light curves for these stars. We also present physical properties, derived from Fourier analysis of light curves, for some of the RR Lyrae stars. We discuss the Oosterhoff classification of Reticulum and use our results to re-derive the distance modulus and age of the cluster. Based on observations taken with the SMARTS 1.3 m telescope operated by the SMARTS Consortium and observations taken at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia, e Inovação (MCTI) da República Federativa do Brasil, the U.S. National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU).

  18. The giant branch of Omega Centauri. II. Mixing versus primordial abundance variations

    International Nuclear Information System (INIS)

    Norris, J.; Bessell, M.S.

    1977-01-01

    The lower giant branch of ω Centauri in the magnitude range 13< V<14 contains weak-G-band stars, CH stars, and CN stars; five stars from a sample of 20 members are clearly peculiar. There is also a positive correlation between the strength of the CN band at lambda3883 and the Ca II H and K lines in this sample, with the calcium lines being strongest in the CH and CN stars. All available BVRI data show that while the wide giant branch of ω Cen in the (V, B--V) -plane extends redward almost to that of 47 Tuc, there is a clear separation of ω Cen from 47 Tuc in the (V, R--I) -plane. This suggests that there are no stars on the giant branch of ω Cen with metal abundance as high as that in 47 Tuc. We obtain an upper limit [Fe/H]approx.-1.0 for a sample of approx.60 ω Cen giants brighter than V=14. This is surprising in view of the result of Freeman and Rodgers that there exist strong-lined RR Lyrae stars on the horizontal branch of ω Cen which are most easily understood in terms of 47 Tucanae-like abundances. While we offer no explanation for the strong-lined RR Lyrae stars, we suggest that the mixed stars on the giant branch of ω Cen are stronger lined than normal because of the effect of CN opacity on their atmospheric structure

  19. Constraints on helium enhancement in the globular cluster M4 (NGC 6121): The horizontal branch test

    International Nuclear Information System (INIS)

    Valcarce, A. A. R.; De Medeiros, J. R.; Catelan, M.; Alonso-García, J.; Cortés, C.

    2014-01-01

    Recent pieces of evidence have revealed that most, and possibly all, globular star clusters are composed of groups of stars that formed in multiple episodes with different chemical compositions. In this sense, it has also been argued that variations in the initial helium abundance (Y) from one population to the next are also the rule, rather than the exception. In the case of the metal-intermediate globular cluster M4 (NGC 6121), recent high-resolution spectroscopic observations of blue horizontal branch (HB) stars (i.e., HB stars hotter than the RR Lyrae instability strip) suggest that a large fraction of blue HB stars are second-generation stars formed with high helium abundances. In this paper, we test this scenario by using recent photometric and spectroscopic data together with theoretical evolutionary computations for different Y values. Comparing the photometric data with the theoretically derived color-magnitude diagrams, we find that the bulk of the blue HB stars in M4 have ΔY ≲ 0.01 with respect to the cluster's red HB stars (i.e., HB stars cooler than the RR Lyrae strip)—a result which is corroborated by comparison with spectroscopically derived gravities and temperatures, which also favor little He enhancement. However, the possible existence of a minority population on the blue HB of the cluster with a significant He enhancement level is also discussed.

  20. Spatially Discordant Alternans and Arrhythmias in Tachypacing-Induced Cardiac Myopathy in Transgenic LQT1 Rabbits: The Importance of IKs and Ca2+ Cycling.

    Directory of Open Access Journals (Sweden)

    Emily Lau

    Full Text Available Remodeling of cardiac repolarizing currents, such as the downregulation of slowly activating K+ channels (IKs, could underlie ventricular fibrillation (VF in heart failure (HF. We evaluated the role of Iks remodeling in VF susceptibility using a tachypacing HF model of transgenic rabbits with Long QT Type 1 (LQT1 syndrome.LQT1 and littermate control (LMC rabbits underwent three weeks of tachypacing to induce cardiac myopathy (TICM. In vivo telemetry demonstrated steepening of the QT/RR slope in LQT1 with TICM (LQT1-TICM; pre: 0.26±0.04, post: 0.52±0.01, P<0.05. In vivo electrophysiology showed that LQT1-TICM had higher incidence of VF than LMC-TICM (6 of 11 vs. 3 of 11, respectively. Optical mapping revealed larger APD dispersion (16±4 vs. 38±6 ms, p<0.05 and steep APD restitution in LQT1-TICM compared to LQT1-sham (0.53±0.12 vs. 1.17±0.13, p<0.05. LQT1-TICM developed spatially discordant alternans (DA, which caused conduction block and higher-frequency VF (15±1 Hz in LQT1-TICM vs. 13±1 Hz in LMC-TICM, p<0.05. Ca2+ DA was highly dynamic and preceded voltage DA in LQT1-TICM. Ryanodine abolished DA in 5 out of 8 LQT1-TICM rabbits, demonstrating the importance of Ca2+ in complex DA formation. Computer simulations suggested that HF remodeling caused Ca2+-driven alternans, which was further potentiated in LQT1-TICM due to the lack of IKs.Compared with LMC-TICM, LQT1-TICM rabbits exhibit steepened APD restitution and complex DA modulated by Ca2+. Our results strongly support the contention that the downregulation of IKs in HF increases Ca2+ dependent alternans and thereby the risk of VF.

  1. A new method of measuring centre-of-mass velocities of radially pulsating stars from high-resolution spectroscopy

    Science.gov (United States)

    Britavskiy, N.; Pancino, E.; Tsymbal, V.; Romano, D.; Fossati, L.

    2018-03-01

    We present a radial velocity analysis of 20 solar neighbourhood RR Lyrae and three Population II Cepheid variables. We obtained high-resolution, moderate-to-high signal-to-noise ratio spectra for most stars; these spectra covered different pulsation phases for each star. To estimate the gamma (centre-of-mass) velocities of the programme stars, we use two independent methods. The first, `classic' method is based on RR Lyrae radial velocity curve templates. The second method is based on the analysis of absorption-line profile asymmetry to determine both pulsational and gamma velocities. This second method is based on the least-squares deconvolution (LSD) technique applied to analyse the line asymmetry that occurs in the spectra. We obtain measurements of the pulsation component of the radial velocity with an accuracy of ±3.5 km s-1. The gamma velocity was determined with an accuracy of ±10 km s-1, even for those stars having a small number of spectra. The main advantage of this method is the possibility of obtaining an estimation of gamma velocity even from one spectroscopic observation with uncertain pulsation phase. A detailed investigation of LSD profile asymmetry shows that the projection factor p varies as a function of the pulsation phase - this is a key parameter, which converts observed spectral line radial velocity variations into photospheric pulsation velocities. As a by-product of our study, we present 41 densely spaced synthetic grids of LSD profile bisectors based on atmospheric models of RR Lyr covering all pulsation phases.

  2. THE ACS LCID PROJECT. I. SHORT-PERIOD VARIABLES IN THE ISOLATED DWARF SPHEROIDAL GALAXIES CETUS AND TUCANA

    International Nuclear Information System (INIS)

    Bernard, Edouard J.; Monelli, Matteo; Gallart, Carme

    2009-01-01

    We present the first study of the variable star populations in the isolated dwarf spheroidal galaxies (dSphs) Cetus and Tucana. Based on Hubble Space Telescope images obtained with the Advanced Camera for Surveys in the F475W and F814W bands, we identified 180 and 371 variables in Cetus and Tucana, respectively. The vast majority are RR Lyrae stars. In Cetus, we also found three anomalous Cepheids (ACs), four candidate binaries and one candidate long-period variable (LPV), while six ACs and seven LPV candidates were found in Tucana. Of the RR Lyrae stars, 147 were identified as fundamental mode (RRab) and only eight as first-overtone mode (RRc) in Cetus, with mean periods of 0.614 and 0.363 day, respectively. In Tucana, we found 216 RRab and 82 RRc giving mean periods of 0.604 and 0.353 day. These values place both galaxies in the so-called Oosterhoff Gap, as is generally the case for dSph. We calculated the distance modulus to both galaxies using different approaches based on the properties of RRab and RRc, namely, the luminosity-metallicity and period-luminosity-metallicity relations, and found values in excellent agreement with previous estimates using independent methods: (m - M) 0,Cet = 24.46 ± 0.12 and (m - M) 0,Tuc = 24.74 ± 0.12, corresponding to 780 ± 40 kpc and 890 ± 50 kpc. We also found numerous RR Lyrae variables pulsating in both modes simultaneously (RRd): 17 in Cetus and 60 in Tucana. Tucana is, after Fornax, the second dSph in which such a large fraction of RRd (∼17%) has been observed. We provide the photometry and pulsation parameters for all the variables, and compare the latter with values from the literature for well studied dSph of the Local Group and Galactic globular clusters. The parallel WFPC2 fields were also searched for variables, as they lie well within the tidal radius of Cetus, and at its limit in the case of Tucana. No variables were found in the latter, while 15 were discovered in the outer field of Cetus (11 RRab, three RRc

  3. GROUP FINDING IN THE STELLAR HALO USING PHOTOMETRIC SURVEYS: CURRENT SENSITIVITY AND FUTURE PROSPECTS

    International Nuclear Information System (INIS)

    Sharma, Sanjib; Johnston, Kathryn V.; Majewski, Steven R.; Bullock, James; Munoz, Ricardo R.

    2011-01-01

    The Sloan Digital Sky Survey (SDSS) and the Two Micron All Sky Survey (2MASS) provided the first deep and global photometric catalogs of stars in our halo and not only clearly mapped its structure but also demonstrated the ubiquity of substructure within it. Future surveys promise to push such catalogs to ever increasing depths and larger numbers of stars. This paper examines what can be learned from current and future photometric databases using group-finding techniques. We compare groups recovered from a sample of M-giants from 2MASS with those found in synthetic surveys of simulated ΛCDM stellar halos that were built entirely from satellite accretion events and demonstrate broad consistency between the properties of the two sets. We also find that these recovered groups are likely to represent the majority of high-luminosity (L > 5 x 10 6 L sun ) satellites accreted within the last 10 Gyr and on orbits with apocenters within 100 kpc. However, the sensitivity of the M-giant survey to accretion events that were either ancient from low-luminosity objects or those on radial orbits is limited because of the low number of stars, bias toward high-metallicity stars, and the shallow depth (distance explored only out to 100 kpc from the Sun). We examine the extent to which these limitations are addressed by current and future surveys, in particular catalogs of main-sequence turnoff (MSTO) stars from SDSS and the Large Synoptic Survey Telescope (LSST), and of RR Lyrae stars from LSST or PanSTARRS. The MSTO and RR Lyrae surveys are more sensitive to low-luminosity events (L ∼ 10 5 L sun or less) than the 2MASS M-giant sample. Additionally, RR Lyrae surveys, with superior depth, are also good at detecting events on highly eccentric orbits whose debris tends to lie beyond 100 kpc. When combined we expect these photometric surveys to provide a comprehensive picture of the last 10 Gyr of Galactic accretion. Events older than this are too phase mixed to be discovered. Pushing

  4. THE VLT-FLAMES TARANTULA SURVEY: THE FASTEST ROTATING O-TYPE STAR AND SHORTEST PERIOD LMC PULSAR-REMNANTS OF A SUPERNOVA DISRUPTED BINARY?

    Energy Technology Data Exchange (ETDEWEB)

    Dufton, P. L.; Dunstall, P. R.; Fraser, M. [Astrophysics Research Centre, School of Mathematics and Physics, Queen' s University Belfast, Belfast BT7 1NN (United Kingdom); Evans, C. J. [UK Astronomy Technology Centre, Royal Observatory Edinburgh, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Brott, I. [University of Vienna, Department of Astronomy, Tuerkenschanzstr. 17, A-1180 Vienna (Austria); Cantiello, M.; Langer, N. [Argelander Institut fuer Astronomie der Universitaet Bonn, Auf dem Huegel 71, 53121 Bonn (Germany); De Koter, A.; Sana, H. [Astronomical Institute ' Anton Pannekoek' , University of Amsterdam, Postbus 94249, 1090 GE Amsterdam (Netherlands); De Mink, S. E. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Henault-Brunet, V.; Taylor, W. D. [Scottish Universities Physics Alliance, Institute for Astronomy, University of Edinburgh, Royal Observatory Edinburgh, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Howarth, I. D. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Lennon, D. J. [ESA, Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Markova, N., E-mail: p.dufton@qub.ac.uk [Institute of Astronomy with NAO, Bulgarian Academy of Sciences, P.O. Box 136, 4700 Smoljan (Bulgaria)

    2011-12-10

    We present a spectroscopic analysis of an extremely rapidly rotating late O-type star, VFTS102, observed during a spectroscopic survey of 30 Doradus. VFTS102 has a projected rotational velocity larger than 500 km s{sup -1} and probably as large as 600 km s{sup -1}; as such it would appear to be the most rapidly rotating massive star currently identified. Its radial velocity differs by 40 km s{sup -1} from the mean for 30 Doradus, suggesting that it is a runaway. VFTS102 lies 12 pc from the X-ray pulsar PSR J0537-6910 in the tail of its X-ray diffuse emission. We suggest that these objects originated from a binary system with the rotational and radial velocities of VFTS102 resulting from mass transfer from the progenitor of PSR J0537-691 and the supernova explosion, respectively.

  5. Investigating light curve modulation via kernel smoothing. I. Application to 53 fundamental mode and first-overtone Cepheids in the LMC

    Science.gov (United States)

    Süveges, Maria; Anderson, Richard I.

    2018-03-01

    Context. Recent studies have revealed a hitherto unknown complexity of Cepheid pulsations by discovering irregular modulated variability using photometry, radial velocities, and interferometry. Aim. We aim to perform a statistically rigorous search and characterization of such phenomena in continuous time, applying it to 53 classical Cepheids from the OGLE-III catalog. Methods: We have used local kernel regression to search for both period and amplitude modulations simultaneously in continuous time and to investigate their detectability. We determined confidence intervals using parametric and non-parametric bootstrap sampling to estimate significance, and investigated multi-periodicity using a modified pre-whitening approach that relies on time-dependent light curve parameters. Results: We find a wide variety of period and amplitude modulations and confirm that first overtone pulsators are less stable than fundamental mode Cepheids. Significant temporal variations in period are more frequently detected than those in amplitude. We find a range of modulation intensities, suggesting that both amplitude and period modulations are ubiquitous among Cepheids. Over the 12-year baseline offered by OGLE-III, we find that period changes are often nonlinear, sometimes cyclic, suggesting physical origins beyond secular evolution. Our method detects modulations (period and amplitude) more efficiently than conventional methods that are reliant on certain features in the Fourier spectrum, and pre-whitens time series more accurately than using constant light curve parameters, removing spurious secondary peaks effectively. Conclusions: Period and amplitude modulations appear to be ubiquitous among Cepheids. Current detectability is limited by observational cadence and photometric precision: detection of amplitude modulation below 3 mmag requires space-based facilities. Recent and ongoing space missions (K2, BRITE, MOST, CoRoT) as well as upcoming ones (TESS, PLATO) will significantly improve detectability of fast modulations, such as cycle-to-cycle variations, by providing high-cadence high-precision photometry. High-quality long-term ground-based photometric time series will remain crucial to study longer-term modulations and to disentangle random fluctuations from secular evolution.

  6. On the of classification of BL Her subtype of the Type II Cepheids

    Directory of Open Access Journals (Sweden)

    Jurkovic Monika I.

    2015-01-01

    Full Text Available The initial reason for studying Type II Cepheids (CWB was for period changes, binarity or any other signs of change other than the pulsation. The GCVS contained 71 objects of this kind in 2012 when the wok started, and that list is now extended to 100 CWB and 26 CWB: objects. The photometric data for the 71 objects was collected from ASAS, AAVSO, CATALINA, LINEAR, SuperWASP, NSVS surveys. Surprisingly, there is a discrepancy in the classification of the stars in this list. A large percentage of these objects might not be not Type II Cepheids, some of them are classical Cepheids, RR Lyrae, some eclipsing binaries, there is even a dwarf novae.

  7. Faint (and bright variable stars in the satellites of the Milky Way

    Directory of Open Access Journals (Sweden)

    Vivas A. Katherina

    2017-01-01

    Full Text Available I describe two ongoing projects related with variable stars in the satellites of the MilkyWay. In the first project, we are searching for dwarf Cepheid stars (a.k.a δ Scuti and/or SX Phe in some of the classical dwarf spheroidal galaxies. Our goal is to characterize the population of these variable stars under different environments (age, metallicity in order to study their use as standard candles in systems for which the metallicity is not necessarily known. In the second project we search for RR Lyrae stars in the new ultra-faint satellite galaxies that have been discovered around the Milky Way in recent years.

  8. Variable Stars in the M31 Dwarf Spheroidal Companion Cassiopeia

    Science.gov (United States)

    Pritzl, Barton J.; Armandroff, T. E.; Jacoby, G. H.; Da Costa, G. S.

    2007-12-01

    Dwarf spheroidal galaxies show very diverse star formation histories. For the Galactic dwarf spheroidal galaxies, a correlation exists between Galactocentric distance and the prominence of intermediate-age ( 2 - 10 Gyr) populations. To test whether this correlation exists for the M31 dwarf spheroidal galaxies, we observed the Cassiopeia (And VII) dwarf galaxy, which is one of the most distant M31 dwarf spheroidal galaxies. We will present the results of a variable star search using HST/ACS data, along with a preliminary color-magnitude diagram. From the RR Lyrae stars we can obtain an independent distance and metallicity estimate for the dwarf galaxy. These results will be compared to those found for the other M31 dwarf spheroidal galaxies.This research is supported in part by NASA through grant number GO-11081.11 from the Space Telescope Science Institute.

  9. Galactic Astronomy in the Ultraviolet

    Science.gov (United States)

    Rastorguev, A. S.; Sachkov, M. E.; Zabolotskikh, M. V.

    2017-12-01

    We propose a number of prospective observational programs for the ultraviolet space observatory WSO-UV, which seem to be of great importance to modern galactic astronomy. The programs include the search for binary Cepheids; the search and detailed photometric study and the analysis of radial distribution of UV-bright stars in globular clusters ("blue stragglers", blue horizontal-branch stars, RR Lyrae variables, white dwarfs, and stars with UV excesses); the investigation of stellar content and kinematics of young open clusters and associations; the study of spectral energy distribution in hot stars, including calculation of the extinction curves in the UV, optical and NIR; and accurate definition of the relations between the UV-colors and effective temperature. The high angular resolution of the observatory allows accurate astrometric measurements of stellar proper motions and their kinematic analysis.

  10. Target Selection for the SDSS-IV APOGEE-2 Survey

    Energy Technology Data Exchange (ETDEWEB)

    Zasowski, G. [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States); Cohen, R. E.; Carlberg, J. K.; Fleming, Scott W. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Chojnowski, S. D.; Holtzman, J. [Department of Astronomy, New Mexico State University, Las Cruces, NM 88001 (United States); Santana, F. [Departamento de Astronomía, Universidad de Chile, Santiago (Chile); Oelkers, R. J.; Bird, J. C. [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States); Andrews, B. [PITT PACC, Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Beaton, R. L. [The Observatories of the Carnegie Institution for Science, Pasadena, CA 91101 (United States); Bender, C.; Cunha, K. [Steward Observatory, The University of Arizona, Tucson, AZ 85719 (United States); Bovy, J. [Department of Astronomy and Astrophysics and Dunlap Institute for Astronomy and Astrophysics, University of Toronto, Toronto, ON M5S 3H4 (Canada); Covey, K. [Department of Physics and Astronomy, Western Washington University, Bellingham, WA 98225 (United States); Dell’Agli, F.; García-Hernández, D. A. [Departamento de Astrofísica, Universidad de La Laguna, and Instituto de Astrofísica de Canarias, La Laguna, Tenerife (Spain); Frinchaboy, P. M. [Department of Physics and Astronomy, Texas Christian University, Fort Worth, TX 76129 (United States); Harding, P. [Department of Astronomy, Case Western Reserve University, Cleveland, OH 44106 (United States); Johnson, J. A., E-mail: gail.zasowski@gmail.com [Department of Astronomy, The Ohio State University, Columbus, OH 43210 (United States); and others

    2017-11-01

    APOGEE-2 is a high-resolution, near-infrared spectroscopic survey observing ∼3 × 10{sup 5} stars across the entire sky. It is the successor to APOGEE and is part of the Sloan Digital Sky Survey IV (SDSS-IV). APOGEE-2 is expanding on APOGEE’s goals of addressing critical questions of stellar astrophysics, stellar populations, and Galactic chemodynamical evolution using (1) an enhanced set of target types and (2) a second spectrograph at Las Campanas Observatory in Chile. APOGEE-2 is targeting red giant branch and red clump stars, RR Lyrae, low-mass dwarf stars, young stellar objects, and numerous other Milky Way and Local Group sources across the entire sky from both hemispheres. In this paper, we describe the APOGEE-2 observational design, target selection catalogs and algorithms, and the targeting-related documentation included in the SDSS data releases.

  11. Constraints on stellar evolution from pulsations

    International Nuclear Information System (INIS)

    Cox, A.N.

    1984-01-01

    Consideration of the many types of intrinsic variable stars, that is, those that pulsate, reveals that perhaps a dozen classes can indicate some constraints that affect the results of stellar evolution calculations, or some interpretations of observations. Many of these constraints are not very strong or may not even be well defined yet. The author discusses the case for six classes: classical Cepheids with their measured Wesselink radii, the observed surface effective temperatures of the known eleven double-mode Cepheids, the pulsation periods and measured surface effective temperatures of three R CrB variables, the delta Scuti variable VZ Cnc with a very large ratio of its two observed periods, the nonradial oscillations of the Sun, and the period ratios of the newly discovered double-mode RR Lyrae variables. (Auth.)

  12. Target Selection for the SDSS-IV APOGEE-2 Survey

    International Nuclear Information System (INIS)

    Zasowski, G.; Cohen, R. E.; Carlberg, J. K.; Fleming, Scott W.; Chojnowski, S. D.; Holtzman, J.; Santana, F.; Oelkers, R. J.; Bird, J. C.; Andrews, B.; Beaton, R. L.; Bender, C.; Cunha, K.; Bovy, J.; Covey, K.; Dell’Agli, F.; García-Hernández, D. A.; Frinchaboy, P. M.; Harding, P.; Johnson, J. A.

    2017-01-01

    APOGEE-2 is a high-resolution, near-infrared spectroscopic survey observing ∼3 × 10 5 stars across the entire sky. It is the successor to APOGEE and is part of the Sloan Digital Sky Survey IV (SDSS-IV). APOGEE-2 is expanding on APOGEE’s goals of addressing critical questions of stellar astrophysics, stellar populations, and Galactic chemodynamical evolution using (1) an enhanced set of target types and (2) a second spectrograph at Las Campanas Observatory in Chile. APOGEE-2 is targeting red giant branch and red clump stars, RR Lyrae, low-mass dwarf stars, young stellar objects, and numerous other Milky Way and Local Group sources across the entire sky from both hemispheres. In this paper, we describe the APOGEE-2 observational design, target selection catalogs and algorithms, and the targeting-related documentation included in the SDSS data releases.

  13. V 1343 aquilae (SS 433) as a double-periodic star

    International Nuclear Information System (INIS)

    Goranskij, V.P.

    1983-01-01

    The new computer method of double periodicity search earlier tested on the Blazhko effect in RR Lyrae type variable stars is applied to define more precise periods of brightness variability of the binary V 1343 Aql (SS 433). Computer program was used in the two-parameter search regime. The obtained periods are P 1 = 13sup(d).074+-0sup(d).008 and P 2 = 163sup(d).8+-1sup(d).2. The periodically repeating brithness curve deeps treated as primary minima (the accretion disc eclipsed by the star) vary their shape with the phase of period P 2 . The expected eclipse at 1979 October 16 did nor occur

  14. Pulsating star research and the Gaia revolution

    Directory of Open Access Journals (Sweden)

    Eyer Laurent

    2017-01-01

    Full Text Available In this article we present an overview of the ESA Gaia mission and of the unprecedented impact that Gaia will have on the field of variable star research. We summarise the contents and impact of the first Gaia data release on the description of variability phenomena, with particular emphasis on pulsating star research. The Tycho-Gaia astrometric solution, although limited to 2.1 million stars, has been used in many studies related to pulsating stars. Furthermore a set of 3,194 Cepheids and RR Lyrae stars with their times series have been released. Finally we present the plans for the ongoing study of variable phenomena with Gaia and highlight some of the possible impacts of the second data release on variable, and specifically, pulsating stars.

  15. Comparative pulsation calculations with OP and OPAL opacities

    Science.gov (United States)

    Kanbur, Shashi M.; Simon, Norman R.

    1994-01-01

    Comparative linear nonadiabatic pulsation calculations are presented using the OPAL and Opacity Project opacities. The two sets of opacities include effects due to intermediate coupling and fine structure as well as new abundances. We used two mass luminosity (M-L) relations, one standard (BIT), and one employing substantial convective core overshoot (COV). The two sets of opacities cannot be differentiated on the basis of the stellar pulsation calculations presented here. The BIT relation can model the beat and bump Cepheids with masses between 4 and 7 solar mass, while if the overshoot relation is used, masses between 2 and 6 solar mass are required. In the RR Lyrae regime, we find the inferred masses of globular cluster RRd stars to be little influenced by the choice of OPAL or OP. Finally, the limited modeling we have done is not able to constrain the Cepheid M-L relation based upon period ratios observed in the beat and bump stars.

  16. Pulsating star research and the Gaia revolution

    Science.gov (United States)

    Eyer, Laurent; Clementini, Gisella; Guy, Leanne P.; Rimoldini, Lorenzo; Glass, Florian; Audard, Marc; Holl, Berry; Charnas, Jonathan; Cuypers, Jan; Ridder, Joris De; Evans, Dafydd W.; de Fombelle, Gregory Jevardat; Lanzafame, Alessandro; Lecoeur-Taibi, Isabelle; Mowlavi, Nami; Nienartowicz, Krzysztof; Riello, Marco; Ripepi, Vincenzo; Sarro, Luis; Süveges, Maria

    2017-09-01

    In this article we present an overview of the ESA Gaia mission and of the unprecedented impact that Gaia will have on the field of variable star research. We summarise the contents and impact of the first Gaia data release on the description of variability phenomena, with particular emphasis on pulsating star research. The Tycho-Gaia astrometric solution, although limited to 2.1 million stars, has been used in many studies related to pulsating stars. Furthermore a set of 3,194 Cepheids and RR Lyrae stars with their times series have been released. Finally we present the plans for the ongoing study of variable phenomena with Gaia and highlight some of the possible impacts of the second data release on variable, and specifically, pulsating stars.

  17. Variability search in M 31 using principal component analysis and the Hubble Source Catalogue

    Science.gov (United States)

    Moretti, M. I.; Hatzidimitriou, D.; Karampelas, A.; Sokolovsky, K. V.; Bonanos, A. Z.; Gavras, P.; Yang, M.

    2018-06-01

    Principal component analysis (PCA) is being extensively used in Astronomy but not yet exhaustively exploited for variability search. The aim of this work is to investigate the effectiveness of using the PCA as a method to search for variable stars in large photometric data sets. We apply PCA to variability indices computed for light curves of 18 152 stars in three fields in M 31 extracted from the Hubble Source Catalogue. The projection of the data into the principal components is used as a stellar variability detection and classification tool, capable of distinguishing between RR Lyrae stars, long-period variables (LPVs) and non-variables. This projection recovered more than 90 per cent of the known variables and revealed 38 previously unknown variable stars (about 30 per cent more), all LPVs except for one object of uncertain variability type. We conclude that this methodology can indeed successfully identify candidate variable stars.

  18. The Taiwanese-American occultation survey project stellar variability. III. Detection of 58 new variable stars

    Energy Technology Data Exchange (ETDEWEB)

    Ishioka, R.; Wang, S.-Y.; Zhang, Z.-W.; Lehner, M. J.; Cook, K. H.; King, S.-K.; Lee, T.; Marshall, S. L.; Schwamb, M. E.; Wang, J.-H.; Wen, C.-Y. [Institute of Astronomy and Astrophysics, Academia Sinica, 11F of Astronomy-Mathematics Building, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan (China); Alcock, C.; Protopapas, P. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Axelrod, T. [Steward Observatory, 933 North Cherry Avenue, Room N204, Tucson, AZ 85721 (United States); Bianco, F. B. [Center for Cosmology and Particle Physics, New York University, 4 Washington Place, New York, NY 10003 (United States); Byun, Y.-I. [Department of Astronomy and University Observatory, Yonsei University, 134 Shinchon, Seoul 120-749 (Korea, Republic of); Chen, W. P.; Ngeow, C.-C. [Institute of Astronomy, National Central University, No. 300, Jhongda Road, Jhongli City, Taoyuan County 320, Taiwan (China); Kim, D.-W. [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Rice, J. A., E-mail: ishioka@asiaa.sinica.edu.tw [Department of Statistics, University of California Berkeley, 367 Evans Hall, Berkeley, CA 94720 (United States)

    2014-04-01

    The Taiwanese-American Occultation Survey project is designed for the detection of stellar occultations by small-size Kuiper Belt Objects, and it has monitored selected fields along the ecliptic plane by using four telescopes with a 3 deg{sup 2} field of view on the sky since 2005. We have analyzed data accumulated during 2005-2012 to detect variable stars. Sixteen fields with observations of more than 100 epochs were examined. We recovered 85 variables among a total of 158 known variable stars in these 16 fields. Most of the unrecovered variables are located in the fields observed less frequently. We also detected 58 variable stars which are not listed in the International Variable Star Index of the American Association of Variable Star Observers. These variable stars are classified as 3 RR Lyrae, 4 Cepheid, 1 δ Scuti, 5 Mira, 15 semi-regular, and 27 eclipsing binaries based on the periodicity and the profile of the light curves.

  19. HIDE AND SEEK BETWEEN ANDROMEDA'S HALO, DISK, AND GIANT STREAM

    Energy Technology Data Exchange (ETDEWEB)

    Clementini, Gisella; Contreras Ramos, Rodrigo; Federici, Luciana; Macario, Giulia; Tosi, Monica; Bellazzini, Michele; Fusi Pecci, Flavio; Diolaiti, Emiliano; Cacciari, Carla [INAF, Osservatorio Astronomico di Bologna, Bologna (Italy); Beccari, Giacomo [European Southern Observatory, 85748 Garching bei Munchen (Germany); Testa, Vincenzo; Giallongo, Emanuele; Di Paola, Andrea; Gallozzi, Stefano [INAF, Osservatorio Astronomico di Roma, Monteporzio (Italy); Cignoni, Michele; Marano, Bruno [Dipartimento di Astronomia, Universita di Bologna, Bologna (Italy); Marconi, Marcella; Ripepi, Vincenzo [INAF, Osservatorio Astronomico di Capodimonte, Napoli (Italy); Ragazzoni, Roberto [INAF, Osservatorio Astronomico di Padova, Padova (Italy); Smareglia, Riccardo, E-mail: gisella.clementini@oabo.inaf.it [INAF, Osservatorio Astronomico di Trieste, Trieste (Italy)

    2011-12-10

    Photometry in B, V (down to V {approx} 26 mag) is presented for two 23' Multiplication-Sign 23' fields of the Andromeda galaxy (M31) that were observed with the blue channel camera of the Large Binocular Telescope during the Science Demonstration Time. Each field covers an area of about 5.1 Multiplication-Sign 5.1 kpc{sup 2} at the distance of M31 ({mu}{sub M31} {approx} 24.4 mag), sampling, respectively, a northeast region close to the M31 giant stream (field S2) and an eastern portion of the halo in the direction of the galaxy minor axis (field H1). The stream field spans a region that includes Andromeda's disk and giant stream, and this is reflected in the complexity of the color-magnitude diagram of the field. One corner of the halo field also includes a portion of the giant stream. Even though these demonstration time data were obtained under non-optimal observing conditions, the B photometry, which was acquired in time-series mode, allowed us to identify 274 variable stars (among which 96 are bona fide and 31 are candidate RR Lyrae stars, 71 are Cepheids, and 16 are binary systems) by applying the image subtraction technique to the selected portions of the observed fields. Differential flux light curves were obtained for the vast majority of these variables. Our sample mainly includes pulsating stars that populate the instability strip from the Classical Cepheids down to the RR Lyrae stars, thus tracing the different stellar generations in these regions of M31 down to the horizontal branch of the oldest (t {approx} 10 Gyr) component.

  20. Ages of the Bulge Globular Clusters NGC 6522 and NGC 6626 (M28) from HST Proper-motion-cleaned Color–Magnitude Diagrams

    Science.gov (United States)

    Kerber, L. O.; Nardiello, D.; Ortolani, S.; Barbuy, B.; Bica, E.; Cassisi, S.; Libralato, M.; Vieira, R. G.

    2018-01-01

    Bulge globular clusters (GCs) with metallicities [Fe/H] ≲ ‑1.0 and blue horizontal branches are candidates to harbor the oldest populations in the Galaxy. Based on the analysis of HST proper-motion-cleaned color–magnitude diagrams in filters F435W and F625W, we determine physical parameters for the old bulge GCs NGC 6522 and NGC 6626 (M28), both with well-defined blue horizontal branches. We compare these results with similar data for the inner halo cluster NGC 6362. These clusters have similar metallicities (‑1.3 ≤ [Fe/H] ≤ ‑1.0) obtained from high-resolution spectroscopy. We derive ages, distance moduli, and reddening values by means of statistical comparisons between observed and synthetic fiducial lines employing likelihood statistics and the Markov chain Monte Carlo method. The synthetic fiducial lines were generated using α-enhanced BaSTI and Dartmouth stellar evolutionary models, adopting both canonical (Y ∼ 0.25) and enhanced (Y ∼ 0.30–0.33) helium abundances. RR Lyrae stars were employed to determine the HB magnitude level, providing an independent indicator to constrain the apparent distance modulus and the helium enhancement. The shape of the observed fiducial line could be compatible with some helium enhancement for NGC 6522 and NGC 6626, but the average magnitudes of RR Lyrae stars tend to rule out this hypothesis. Assuming canonical helium abundances, BaSTI and Dartmouth models indicate that all three clusters are coeval, with ages between ∼12.5 and 13.0 Gyr. The present study also reveals that NGC 6522 has at least two stellar populations, since its CMD shows a significantly wide subgiant branch compatible with 14% ± 2% and 86% ± 5% for first and second generations, respectively. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute.

  1. THE ABSOLUTE MAGNITUDE OF RRc VARIABLES FROM STATISTICAL PARALLAX

    International Nuclear Information System (INIS)

    Kollmeier, Juna A.; Burns, Christopher R.; Thompson, Ian B.; Preston, George W.; Crane, Jeffrey D.; Madore, Barry F.; Morrell, Nidia; Prieto, José L.; Shectman, Stephen; Simon, Joshua D.; Villanueva, Edward; Szczygieł, Dorota M.; Gould, Andrew; Sneden, Christopher; Dong, Subo

    2013-01-01

    We present the first definitive measurement of the absolute magnitude of RR Lyrae c-type variable stars (RRc) determined purely from statistical parallax. We use a sample of 242 RRc variables selected from the All Sky Automated Survey for which high-quality light curves, photometry, and proper motions are available. We obtain high-resolution echelle spectra for these objects to determine radial velocities and abundances as part of the Carnegie RR Lyrae Survey. We find that M V,RRc = 0.59 ± 0.10 at a mean metallicity of [Fe/H] = –1.59. This is to be compared with previous estimates for RRab stars (M V,RRab = 0.76 ± 0.12) and the only direct measurement of an RRc absolute magnitude (RZ Cephei, M V,RRc = 0.27 ± 0.17). We find the bulk velocity of the halo relative to the Sun to be (W π , W θ , W z ) = (12.0, –209.9, 3.0) km s –1 in the radial, rotational, and vertical directions with dispersions (σ W π ,σ W θ ,σ W z ) = (150.4, 106.1, 96.0) km s -1 . For the disk, we find (W π , W θ , W z ) = (13.0, –42.0, –27.3) km s –1 relative to the Sun with dispersions (σ W π ,σ W θ ,σ W z ) = (67.7,59.2,54.9) km s -1 . Finally, as a byproduct of our statistical framework, we are able to demonstrate that UCAC2 proper-motion errors are significantly overestimated as verified by UCAC4

  2. Near-IR period-luminosity relations for pulsating stars in ω Centauri (NGC 5139)

    Science.gov (United States)

    Navarrete, C.; Catelan, M.; Contreras Ramos, R.; Alonso-García, J.; Gran, F.; Dékány, I.; Minniti, D.

    2017-08-01

    Aims: The globular cluster ω Centauri (NGC 5139) hosts hundreds of pulsating variable stars of different types, thus representing a treasure trove for studies of their corresponding period-luminosity (PL) relations. Our goal in this study is to obtain the PL relations for RR Lyrae and SX Phoenicis stars in the field of the cluster, based on high-quality, well-sampled light curves in the near-infrared (IR). Methods: Observations were carried out using the VISTA InfraRed CAMera (VIRCAM) mounted on the Visible and Infrared Survey Telescope for Astronomy (VISTA). A total of 42 epochs in J and 100 epochs in KS were obtained, spanning 352 days. Point-spread function photometry was performed using DoPhot and DAOPHOT crowded-field photometry packages in the outer and inner regions of the cluster, respectively. Results: Based on the comprehensive catalog of near-IR light curves thus secured, PL relations were obtained for the different types of pulsators in the cluster, both in the J and KS bands. This includes the first PL relations in the near-IR for fundamental-mode SX Phoenicis stars. The near-IR magnitudes and periods of Type II Cepheids and RR Lyrae stars were used to derive an updated true distance modulus to the cluster, with a resulting value of (m - M)0 = 13.708 ± 0.035 ± 0.10 mag, where the error bars correspond to the adopted statistical and systematic errors, respectively. Adding the errors in quadrature, this is equivalent to a heliocentric distance of 5.52 ± 0.27 kpc. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile, with the VISTA telescope (project ID 087.D-0472, PI R. Angeloni).

  3. Estimating the parameters of globular cluster M 30 (NGC 7099) from time-series photometry

    DEFF Research Database (Denmark)

    Kains, N.; Bramich, D.M.; Figuera Jaimes, R.

    2013-01-01

    Aims. We present the analysis of 26 nights of V and I time-series observations from 2011 and 2012 of the globular cluster M 30 (NGC 7099). We used our data to search for variable stars in this cluster and refine the periods of known variables; we then used our variable star light curves to derive...... values for the cluster's parameters. Methods. We used difference image analysis to reduce our data to obtain high-precision light curves of variable stars. We then estimated the cluster parameters by performing a Fourier decomposition of the light curves of RR Lyrae stars for which a good period estimate...... stars to derive cluster parameters using empirical relations. We find a cluster metallicity [Fe/H]ZW =-2.01 ± 0.04, or [Fe/H]UVES =-2.11 ± 0.06, and a distance of 8.32 ± 0.20 kpc (using RR0 variables), 8.10 kpc (using one RR1 variable), and 8.35 ± 0.42 kpc (using our SX Phoenicis star detection in M 30...

  4. Bent CNN bond of diazo compounds, RR'(Cdbnd N+dbnd N-)

    Science.gov (United States)

    Akita, Motoko; Takahashi, Mai; Kobayashi, Keiji; Hayashi, Naoto; Tukada, Hideyuki

    2013-02-01

    The reaction of ninhydrin with benzophenone hydrazone afforded 2-diazo-3-diphenylmethylenehydrazono-1-indanone 1 and 2-diazo-1,3-bis(diphenylmethylenehydrazono)indan 2. X-ray crystal structure analyses of these products showed that the diazo functional group Cdbnd N+dbnd N- of 1 is bent by 172.9°, while that of 2 has a linear geometry. The crystal structure data of diazo compounds have been retrieved from the Cambridge Structural Database (CSD), which hit 177 entries to indicate that the angle of 172.9° in 1 lies in one of the most bent structures. The CSD search also indicated that diazo compounds consisting of a distorted diazo carbon tend to bend the Cdbnd N+dbnd N- bond. On the basis of DFT calculations (B3LYP/6-311++G(d,p)) of model compounds, it was revealed that the bending of the CNN bond is principally induced by steric factors and that the neighboring carbonyl group also plays a role in bending toward the carbonyl side owing to an electrostatic attractive interaction. The potential surface along the path of Cdbnd N+dbnd N- bending in 2-diazopropane shows a significantly shallow profile with only 4 kcal/mol needed to bend the Cdbnd N+dbnd N- bond from 180° to 160°. Thus, the bending of the diazo group in 1 is reasonable as it is provided with all of the factors for facile bending disclosed in this investigation.

  5. First experience in international air transportation of RR SFA in Russian-made TUK-19 casks

    International Nuclear Information System (INIS)

    Kanashov, B.A.; Barinkov, O.P.; Dorofeev, A.N.; Komarov, S.V.; Smirnov, A.V.; Biro, L.; Budu, M.; Ciocanescu, M.

    2010-01-01

    Traditionally, spent fuel assemblies (SFA) have been transported across the Russian Federation by rail in special railcars. New conditions required SFA shipments by other conveyance, i.e. road, sea and even air transport. The air shipment of the VVR-S research reactor SNF in TUK-19 casks from Magurele, Romania in June 2009 was the first experience after new Russian and international regulations for the safe transport of radioactive material came into effect. The preparatory stage of the shipment focused on the issues associated with radiation and nuclear safety both during the loading and transport operations. The project covered development of a technology and equipment for SFA loading into TUK-19 casks and that for the air shipment. The SFAs were loaded into the TUK-19 casks with a specially designed transfer cask, and the SFA-containing packages were transported in specialized freight 20-foot ISO-containers. The safety of the loading and transport operations was ensured both by reliable engineering solutions, and selected conveyances and routes. The paper shows that the loading and the air shipment of the Romanian SFAs in TUK-19 casks does not contradict Romanian, Russian and international regulations for the safe transport of radioactive material. The outcomes of the SNF shipment from Romania confirmed correctness of the solutions and demonstrated high environmental safety. (author)

  6. Conceptualizing Accessibility for English Language Proficiency Assessments. Research Report. ETS RR-16-07

    Science.gov (United States)

    Guzman-Orth, Danielle; Laitusis, Cara; Thurlow, Martha; Christensen, Laurene

    2016-01-01

    This paper is the second in a series from Educational Testing Service (ETS) that conceptualizes next-generation English language proficiency (ELP) assessment systems for K-12 English learners (ELs) in the United States.The first paper articulated a high-level conceptualization of next-generation ELP assessment systems (Hauck, Wolf, & Mislevy,…

  7. Work space optimization of a r-r planar manipulator using particle ...

    African Journals Online (AJOL)

    *Corresponding Author (1) E-Mail:chaitanyagoteti16@gmail.com ... presented the variable structure theory for planning and trajectory control of planar ..... Rao S.S., 2009, Engineering Optimization Theory and Practice, 4th edition, Ed., John ...

  8. Measuring Motivation in Low-Stakes Assessments. Research Report. ETS RR-15-19

    Science.gov (United States)

    Finn, Bridgid

    2015-01-01

    There is a growing concern that when scores from low-stakes assessments are reported without considering student motivation as a construct of interest, biased conclusions about how much students know will result. Low motivation is a problem particularly relevant to low-stakes testing scenarios, which may be low stakes for the test taker but have…

  9. Bias Correction for the Maximum Likelihood Estimate of Ability. Research Report. ETS RR-05-15

    Science.gov (United States)

    Zhang, Jinming

    2005-01-01

    Lord's bias function and the weighted likelihood estimation method are effective in reducing the bias of the maximum likelihood estimate of an examinee's ability under the assumption that the true item parameters are known. This paper presents simulation studies to determine the effectiveness of these two methods in reducing the bias when the item…

  10. Management system quality of service radio physics and RR. ISO 9001

    International Nuclear Information System (INIS)

    Gil Agudo, A.; Torres Donaire, J.; Jimenez, J. C.; Carrascosa Fernandez, C.; Arjona Gutierrez, J.

    2011-01-01

    One of the tool increasingly deployed for the optimization of the procedures is the process management system according to a Quality Management. Likewise, for specific areas, such as central services within large institutions such as the General Hospitals of the systems of quality management is the most widely used ISO 9001. We describe in this paper our experience in implementing the system ISO 9001 in our Department of Radio physics and Radiation Protection (SRFPR).

  11. In-service inspection of ET-RR-1 reactor vessels and spent fuel storage tank

    International Nuclear Information System (INIS)

    Khattab, M.; Shafy, M.; Konoplev, K.; Samodurve, YU.; Orlov, S.; Didenko, V.; Jackorev, O.

    1993-01-01

    Technical survey included in-service inspection are needed in order to investigate the structural integrity and to insure safe operation of the ET-R R-1 reactor after thirty years aging. An intensive work for the inspection of the inspection of the central tank, shield tank, horizontal channels, primary coolant circuit and spent fuel storage tank have been carried out. The inspection procedures were visual method using video camera and magnification optical as well as thickness measurements using ultrasonic gauge meter and replica for determining defect depth. Water chemical analysis of the primary cooling circuit and spent fuel storage were helpful in results explanation. The results showed that the reactor vessels have good surface conditions. The observed pitting did not affect the structural integrity. The majority of the defects were pits having maximum surface area of about 50 mm. Their depth does not exceed 2 mm. The pits depth rate penetration is of the order of 0.5% per year. Thickness measurements showed insignificant variation. Water status and its chemical properties are very important in controlling corrosion rate. 18 figs., 14 tabs

  12. Conformal blocks related to the R-R states in the c^=1 superconformal field theories

    Science.gov (United States)

    Hadasz, Leszek; Jaskólski, Zbigniew; Suchanek, Paulina

    2008-01-01

    We derive an explicit form of the family of four-point Neveu-Schwarz blocks with c^=1, external weights Δi=(1)/(8) and arbitrary intermediate weight Δ. The derivation is based on analytic properties of correlation functions of Ramond fields in the free superscalar theory.

  13. 77 FR 2932 - Airworthiness Directives; Rolls-Royce plc (RR) Turbofan Engines

    Science.gov (United States)

    2012-01-20

    ...-pressure (IP) compressor rotor shaft rear balance land for cracks, which could lead to engine failure. This...; fax: 011-44-1332-245418 or email from http://www.rolls-royce.com/contact/civil_team.jsp . You may..., 12 New England Executive Park, Burlington, MA; phone: (781) 238-7143; fax: (781) 238-7199; email...

  14. Work space optimization of a r-r planar manipulator using particle ...

    African Journals Online (AJOL)

    A two link revolute planar robotic manipulator is optimized for maximization of work space covered by its end effector. A mathematical model for optimization is built considering singularities which control the range of design variables. Condition number which is the measure of change in output value (End effector position) ...

  15. Using Complexity Metrics With R-R Intervals and BPM Heart Rate Measures

    DEFF Research Database (Denmark)

    Wallot, Sebastian; Fusaroli, Riccardo; Tylén, Kristian

    2013-01-01

    Lately, growing attention in the health sciences has been paid to the dynamics of heart rate as indicator of impending failures and for prognoses. Likewise, in social and cognitive sciences, heart rate is increasingly employed as a measure of arousal, emotional engagement and as a marker of inter......Lately, growing attention in the health sciences has been paid to the dynamics of heart rate as indicator of impending failures and for prognoses. Likewise, in social and cognitive sciences, heart rate is increasingly employed as a measure of arousal, emotional engagement and as a marker...... of interpersonal coordination. However, there is no consensus about which measurements and analytical tools are most appropriate in mapping the temporal dynamics of heart rate and quite different metrics are reported in the literature. As complexity metrics of heart rate variability depend critically...

  16. EPCAL: ETS Platform for Collaborative Assessment and Learning. Research Report. ETS RR-17-49

    Science.gov (United States)

    Hao, Jiangang; Liu, Lei; von Davier, Alina A.; Lederer, Nathan; Zapata-Rivera, Diego; Jaki, Peter; Bakkenson, Michael

    2017-01-01

    Most existing software tools for online collaboration are designed to support the collaboration itself instead of the study of collaboration with a systematic team and task management system. In this report, we identify six important features for a platform to facilitate the study of online collaboration. We then introduce the Educational Testing…

  17. 50 CFR 679.5 - Recordkeeping and reporting (R&R).

    Science.gov (United States)

    2010-10-01

    ...) Whether gear is fixed hook (conventional or tub), autoline, or snap (optional, but may be required by IPHC... the daily weight of groundfish, daily weight of herring PSC, and daily number of PSC animals. If no... of groundfish weights and number of PSC animals separately by reporting area, management program, and...

  18. Case02: BIM hos større ingeniørrådgiver

    DEFF Research Database (Denmark)

    Vestergaard, Flemming; Karlshøj, Jan; Hauch, Peter

    IKT-konceptet Casen repræsenterer et fuldt faseforløb for et byggeprojekt fra programmeringsfasen over projektering og udførelse til start af driften. Der er eksempler på anvendelse af modelbaserede metoder og værktø-jer fra projekteringsfasens start til drift og ombygning. IKT-konceptet repræsen...

  19. Corporate Child Care Options. A Position Paper by Catalyst. RR#1.

    Science.gov (United States)

    Catalyst, New York, NY.

    Described are principal options through which employers may address the child care concerns of their employees. Options fall into four general categories: financial assistance, time availability, direct care services, and provision of information. The principal options in the category of financial assistance are dependent care assistance plans and…

  20. Change in Mouse Bone Turnover in Response to Microgravity on RR-1

    Science.gov (United States)

    Cheng-Campbell, Margareth A.; Blaber, Elizabeth A.; Almeida, Eduardo A. C.

    2016-01-01

    Mechanical unloading during spaceflight is known to adversely affect mammalian physiology. Our previous studies using the Animal Enclosure Module on short duration Shuttle missions enabled us to identify a deficit in stem cell based-tissue regeneration as being a significant concern for long-duration spaceflight. Specifically, we found that mechanical unloading in microgravity resulted in inhibition of differentiation of mesenchymal and hematopoietic stem cells in the bone marrow compartment. Also, we observed overexpression of a cell cycle arrest molecule, CDKN1ap21, in osteoprecursor cells on the bone surface, chondroprogenitors in the articular cartilage, and in myofibers attached to bone tissue. Specifically in bone tissue during both short (15-day) and long (30-day) microgravity experiments, we observed significant loss of bone tissue and structure in both the pelvis and the femur. After 15-days of microgravity on STS-131, pelvic ischium displayed a 6.23 decrease in bone fraction (p0.005) and 11.91 decrease in bone thickness (p0.002). Furthermore, during long-duration spaceflight we observed onset of an accelerated aging-like phenotype and osteoarthritic disease state indicating that stem cells within the bone tissue fail to repair and regenerate tissues in a normal manner, leading to drastic tissue alterations in response to microgravity. The Rodent Research Hardware System provides the capability to investigate these effects during long-duration experiments on the International Space Station. During the Rodent Research-1 mission 10 16-week-old female C57Bl6J mice were exposed to 37-days of microgravity. All flight animals were euthanized and frozen on orbit for future dissection. Ground (n10) and vivarium controls (n10) were housed and processed to match the flight animal timeline. During this study we collected pelvis, femur, and tibia from all animal groups to test the hypothesis that stem cell-based tissue regeneration is significantly altered after 37-days of spaceflight. To do this, we will analyze differences in bone morphometric parameters using MicroCT. The pelvis, femur, and tibia are key in supporting and distributing weight under normal conditions. Therefore, we expect to see altered remodeling in flight animals in response to microgravity with respect to ground controls. In combination with histomorphometry, these results will help elucidate the complex mechanisms underlying bone tissue maintenance and stem cell regeneration.