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Sample records for cluster survey ii

  1. The Extended Northern ROSAT Galaxy Cluster Survey (NORAS II). I. Survey Construction and First Results

    Energy Technology Data Exchange (ETDEWEB)

    Böhringer, Hans; Chon, Gayoung; Trümper, Joachim [Max-Planck-Institut für Extraterrestrische Physik, D-85748 Garching (Germany); Retzlaff, Jörg [ESO, D-85748 Garching (Germany); Meisenheimer, Klaus [Max-Planck-Institut für Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Schartel, Norbert [ESAC, Camino Bajo del Castillo, Villanueva de la Cañada, E-28692 Madrid (Spain)

    2017-05-01

    As the largest, clearly defined building blocks of our universe, galaxy clusters are interesting astrophysical laboratories and important probes for cosmology. X-ray surveys for galaxy clusters provide one of the best ways to characterize the population of galaxy clusters. We provide a description of the construction of the NORAS II galaxy cluster survey based on X-ray data from the northern part of the ROSAT All-Sky Survey. NORAS II extends the NORAS survey down to a flux limit of 1.8 × 10{sup −12} erg s{sup −1} cm{sup −2} (0.1–2.4 keV), increasing the sample size by about a factor of two. The NORAS II cluster survey now reaches the same quality and depth as its counterpart, the southern REFLEX II survey, allowing us to combine the two complementary surveys. The paper provides information on the determination of the cluster X-ray parameters, the identification process of the X-ray sources, the statistics of the survey, and the construction of the survey selection function, which we provide in numerical format. Currently NORAS II contains 860 clusters with a median redshift of z  = 0.102. We provide a number of statistical functions, including the log N –log S and the X-ray luminosity function and compare these to the results from the complementary REFLEX II survey. Using the NORAS II sample to constrain the cosmological parameters, σ {sub 8} and Ω{sub m}, yields results perfectly consistent with those of REFLEX II. Overall, the results show that the two hemisphere samples, NORAS II and REFLEX II, can be combined without problems into an all-sky sample, just excluding the zone of avoidance.

  2. The STREGA survey - II. Globular cluster Palomar 12★

    Science.gov (United States)

    Musella, I.; Di Criscienzo, M.; Marconi, M.; Raimondo, G.; Ripepi, V.; Cignoni, M.; Bono, G.; Brocato, E.; Dall'Ora, M.; Ferraro, I.; Grado, A.; Iannicola, G.; Limatola, L.; Molinaro, R.; Moretti, M. I.; Stetson, P. B.; Capaccioli, M.; Cioni, M.-R. L.; Getman, F.; Schipani, P.

    2018-01-01

    In the framework of the STREGA (STRucture and Evolution of the GAlaxy) survey, two fields around the globular cluster Pal 12 were observed with the aim of detecting the possible presence of streams and/or an extended halo. The adopted stellar tracers are the main sequence, turn-off and red giant branch stars. We discuss the luminosity function and the star counts in the observed region covering about 2 tidal radii, confirming that Pal 12 appears to be embedded in the Sagittarius Stream. Adopting an original approach to separate cluster and field stars, we do not find any evidence of significant extra-tidal Pal 12 stellar populations. The presence of the Sagittarius stream seems to have mimicked a larger tidal radius in previous studies. Indeed, adopting a King model, a redetermination of this value gives rT = 0.22 ± 0.1 deg.

  3. THE SWIFT AGN AND CLUSTER SURVEY. II. CLUSTER CONFIRMATION WITH SDSS DATA

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, Rhiannon D.; Dai, Xinyu [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, OK 73019 (United States); Kochanek, Christopher S. [Department of Astronomy, Ohio State University, Columbus, OH 43210 (United States); Bregman, Joel N., E-mail: Rhiannon.D.Griffin-1@ou.edu, E-mail: xdai@ou.edu, E-mail: ckochanek@astronomy.ohio-state.edu, E-mail: jbregman@umich.edu [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States)

    2016-01-15

    We study 203 (of 442) Swift AGN and Cluster Survey extended X-ray sources located in the SDSS DR8 footprint to search for galaxy over-densities in three-dimensional space using SDSS galaxy photometric redshifts and positions near the Swift cluster candidates. We find 104 Swift clusters with a >3σ galaxy over-density. The remaining targets are potentially located at higher redshifts and require deeper optical follow-up observations for confirmation as galaxy clusters. We present a series of cluster properties including the redshift, brightest cluster galaxy (BCG) magnitude, BCG-to-X-ray center offset, optical richness, and X-ray luminosity. We also detect red sequences in ∼85% of the 104 confirmed clusters. The X-ray luminosity and optical richness for the SDSS confirmed Swift clusters are correlated and follow previously established relations. The distribution of the separations between the X-ray centroids and the most likely BCG is also consistent with expectation. We compare the observed redshift distribution of the sample with a theoretical model, and find that our sample is complete for z ≲ 0.3 and is still 80% complete up to z ≃ 0.4, consistent with the SDSS survey depth. These analysis results suggest that our Swift cluster selection algorithm has yielded a statistically well-defined cluster sample for further study of cluster evolution and cosmology. We also match our SDSS confirmed Swift clusters to existing cluster catalogs, and find 42, 23, and 1 matches in optical, X-ray, and Sunyaev–Zel’dovich catalogs, respectively, and so the majority of these clusters are new detections.

  4. ALMA Survey of Class II Disks in the Young Stellar Cluster IC 348

    Science.gov (United States)

    Ruiz, Dary; Cieza, Lucas; Williams, Jonathan; Andrews, Sean; Principe, David

    2018-01-01

    We present a 1.3 mm continuum survey of the young (2-3 Myr) stellar cluster IC 348 at a distance of 270 pc, which is dominated by low-mass stars. We observed 146 Class II sources (disks that are optically thick in the infrared) at 0.8 '' (200 au) resolution with a 3σ sensitivity of 0.2 MEarth. We detect 46 of the targets and construct a disk luminosity function. We compare the disk mass distribution in IC 348 to those of younger and older regions, taking into account the dependence on stellar mass. We find a clear evolution in disk masses from 1 to 5-10 Myr. The disk masses in IC 348 are significantly lower than those in Taurus (1-2 Myr) and Lupus (1-3 Myr), similar to those of Chamaleon I, (2-3 Myr) and σ-Ori (3-5 Myr) and significantly higher than in Upper Scorpius (5-10 Myr). About 20 disks in our sample (~5% of the cluster members) have estimated masses (dust + gas) of >1 MJUP. and might be the precursors of giant planets in the cluster. Some of the most massive disks include transition objects with inner opacity holes based on their infrared SEDs. From an stacking analysis of the 90 non-detections, we find that these disks have a typical dust mass of just ≤ 0.1 MEarth, even though the vast majority of their infrared SEDs remain optically thick and show little signs of evolution. Such low-mass disks are likely to be the precursors of the small rocky planets found by Kepler around M-type stars.

  5. The Hubble Space Telescope Cluster Supernova Survey. II. The Type Ia Supernova Rate in High-redshift Galaxy Clusters

    Science.gov (United States)

    Barbary, K.; Aldering, G.; Amanullah, R.; Brodwin, M.; Connolly, N.; Dawson, K. S.; Doi, M.; Eisenhardt, P.; Faccioli, L.; Fadeyev, V.; Fakhouri, H. K.; Fruchter, A. S.; Gilbank, D. G.; Gladders, M. D.; Goldhaber, G.; Goobar, A.; Hattori, T.; Hsiao, E.; Huang, X.; Ihara, Y.; Kashikawa, N.; Koester, B.; Konishi, K.; Kowalski, M.; Lidman, C.; Lubin, L.; Meyers, J.; Morokuma, T.; Oda, T.; Panagia, N.; Perlmutter, S.; Postman, M.; Ripoche, P.; Rosati, P.; Rubin, D.; Schlegel, D. J.; Spadafora, A. L.; Stanford, S. A.; Strovink, M.; Suzuki, N.; Takanashi, N.; Tokita, K.; Yasuda, N.; Supernova Cosmology Project

    2012-01-01

    We report a measurement of the Type Ia supernova (SN Ia) rate in galaxy clusters at 0.9 z z > 0.9 SNe. Finding 8 ± 1 cluster SNe Ia, we determine an SN Ia rate of 0.50+0.23 -0.19 (stat) +0.10 -0.09 (sys) h 2 70 SNuB (SNuB ≡ 10-12 SNe L -1 ⊙, B yr-1). In units of stellar mass, this translates to 0.36+0.16 -0.13 (stat) +0.07 -0.06 (sys) h 2 70 SNuM (SNuM ≡ 10-12 SNe M -1 ⊙ yr-1). This represents a factor of ≈5 ± 2 increase over measurements of the cluster rate at z influence of younger stellar populations by calculating the rate specifically in cluster red-sequence galaxies and in morphologically early-type galaxies, finding results similar to the full cluster rate. Finally, the upper limit of one hostless cluster SN Ia detected in the survey implies that the fraction of stars in the intra-cluster medium is less than 0.47 (95% confidence), consistent with measurements at lower redshifts. Based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the Space Telescope Institute. STScI is operated by the association of Universities for Research in Astronomy, Inc., under the NASA contract NAS 5-26555. The observations are associated with program GO-10496.

  6. Cosmology with cluster surveys

    Indian Academy of Sciences (India)

    Surveys of clusters of galaxies provide us with a powerful probe of the density and nature of the dark energy. The red-shift distribution of detected clusters is highly sensitive to the dark energy equation of state parameter . Upcoming Sunyaev–Zel'dovich (SZ) surveys would provide us large yields of clusters to very high ...

  7. Cosmology with cluster surveys

    Indian Academy of Sciences (India)

    Cosmology with cluster surveys. SUBHABRATA MAJUMDAR. CITA, University of Toronto, Toronto, ON, M5S 3H8, Canada. E-mail: subha@cita.utoronto.ca. Abstract. Surveys of clusters of galaxies provide us with a powerful probe of the den- sity and nature of the dark energy. The red-shift distribution of detected clusters is.

  8. A Measurement of the Rate of Type Ia Supernovae in Galaxy Clusters from the SDSS-II Supernova Survey

    Energy Technology Data Exchange (ETDEWEB)

    Dilday, Benjamin; /Rutgers U., Piscataway /Chicago U. /KICP, Chicago; Bassett, Bruce; /Cape Town U., Dept. Math. /South African Astron. Observ.; Becker, Andrew; /Washington U., Seattle, Astron. Dept.; Bender, Ralf; /Munich, Tech. U. /Munich U. Observ.; Castander, Francisco; /Barcelona, IEEC; Cinabro, David; /Wayne State U.; Frieman, Joshua A.; /Chicago U. /Fermilab; Galbany, Lluis; /Barcelona, IFAE; Garnavich, Peter; /Notre Dame U.; Goobar, Ariel; /Stockholm U., OKC /Stockholm U.; Hopp, Ulrich; /Munich, Tech. U. /Munich U. Observ. /Tokyo U.

    2010-03-01

    We present measurements of the Type Ia supernova (SN) rate in galaxy clusters based on data from the Sloan Digital Sky Survey-II (SDSS-II) Supernova Survey. The cluster SN Ia rate is determined from 9 SN events in a set of 71 C4 clusters at z {le} 0.17 and 27 SN events in 492 maxBCG clusters at 0.1 {le} z {le} 0.3. We find values for the cluster SN Ia rate of (0.37{sub -0.12-0.01}{sup +0.17+0.01}) SNur h{sup 2} and (0.55{sub -0.11-0.01}{sup +0.13+0.02}) SNur h{sup 2} (SNux = 10{sup -12}L{sub x{circle_dot}}{sup -1} yr{sup -1}) in C4 and maxBCG clusters, respectively, where the quoted errors are statistical and systematic, respectively. The SN rate for early-type galaxies is found to be (0.31{sub -0.12-0.01}{sup +0.18+0.01}) SNur h{sup 2} and (0.49{sub -0.11-0.01}{sup +0.15+0.02}) SNur h{sup 2} in C4 and maxBCG clusters, respectively. The SN rate for the brightest cluster galaxies (BCG) is found to be (2.04{sub -1.11-0.04}{sup +1.99+0.07}) SNur h{sup 2} and (0.36{sub -0.30-0.01}{sup +0.84+0.01}) SNur h{sup 2} in C4 and maxBCG clusters, respectively. The ratio of the SN Ia rate in cluster early-type galaxies to that of the SN Ia rate in field early-type galaxies is 1.94{sub -0.91-0.015}{sup +1.31+0.043} and 3.02{sub -1.03-0.048}{sup +1.31+0.062}, for C4 and maxBCG clusters, respectively. The SN rate in galaxy clusters as a function of redshift, which probes the late time SN Ia delay distribution, shows only weak dependence on redshift. Combining our current measurements with previous measurements, we fit the cluster SN Ia rate data to a linear function of redshift, and find r{sub L} = [(0.49{sub -0.14}{sup +0.15}) + (0.91{sub -0.81}{sup +0.85}) x z] SNuB h{sup 2}. A comparison of the radial distribution of SNe in cluster to field early-type galaxies shows possible evidence for an enhancement of the SN rate in the cores of cluster early-type galaxies. With an observation of at most 3 hostless, intra-cluster SNe Ia, we estimate the fraction of cluster SNe that are

  9. The HST/ACS Coma Cluster Survey. II. Data Description and Source Catalogs

    Science.gov (United States)

    Hammer, Derek; Kleijn, Gijs Verdoes; Hoyos, Carlos; Den Brok, Mark; Balcells, Marc; Ferguson, Henry C.; Goudfrooij, Paul; Carter, David; Guzman, Rafael; Peletier, Reynier F.; hide

    2010-01-01

    The Coma cluster, Abell 1656, was the target of a HST-ACS Treasury program designed for deep imaging in the F475W and F814W passbands. Although our survey was interrupted by the ACS instrument failure in early 2007, the partially-completed survey still covers approximately 50% of the core high density region in Coma. Observations were performed for twenty-five fields with a total coverage area of 274 aremin(sup 2), and extend over a wide range of cluster-centric radii (approximately 1.75 Mpe or 1 deg). The majority of the fields are located near the core region of Coma (19/25 pointings) with six additional fields in the south-west region of the cluster. In this paper we present SEXTRACTOR source catalogs generated from the processed images, including a detailed description of the methodology used for object detection and photometry, the subtraction of bright galaxies to measure faint underlying objects, and the use of simulations to assess the photometric accuracy and completeness of our catalogs. We also use simulations to perform aperture corrections for the SEXTRACTOR Kron magnitudes based only on the measured source flux and its half-light radius. We have performed photometry for 76,000 objects that consist of roughly equal numbers of extended galaxies and unresolved objects. Approximately two-thirds of all detections are brighter than F814W=26.5 mag (AB), which corresponds to the 10sigma, point-source detection limit. We estimate that Coma members are 5-10% of the source detections, including a large population of compact objects (primarily GCs, but also cEs and UCDs), and a wide variety of extended galaxies from cD galaxies to dwarf low surface brightness galaxies. The initial data release for the HST-ACS Coma Treasury program was made available to the public in August 2008. The images and catalogs described in this study relate to our second data release.

  10. A CFH12k lensing survey of X-ray luminous galaxy clusters - II. Weak lensing analysis and global correlations

    NARCIS (Netherlands)

    Bardeau, S.; Soucail, G.; Kneib, J.-P.; Czoske, O.; Ebeling, H.; Hudelot, P.; Smail, I.; Smith, G. P.

    Aims. We present a wide-field multi-color survey of a homogeneous sample of eleven clusters of galaxies for which we measure total masses and mass distributions from weak lensing. This sample, spanning a small range in both X-ray luminosity and redshift, is ideally suited to determining the

  11. The extended ROSAT-ESO Flux-Limited X-ray Galaxy Cluster Survey (REFLEX II). VII. The mass function of galaxy clusters

    Science.gov (United States)

    Böhringer, Hans; Chon, Gayoung; Fukugita, Masataka

    2017-12-01

    The mass function of galaxy clusters is a sensitive tracer of the gravitational evolution of the cosmic large-scale structure and serves as an important census of the fraction of matter bound in large structures. We obtain the mass function by fitting the observed cluster X-ray luminosity distribution from the REFLEX galaxy cluster survey to models of cosmological structure formation. We marginalise over uncertainties in the cosmological parameters as well as those of the relevant galaxy cluster scaling relations. The mass function is determined with an uncertainty of less than 10% in the mass range 3 × 1012 to 5 × 1014M⊙. For the cumulative mass function we find a slope at the low-mass end consistent with a value of - 1, while the mass-rich end cut-off is milder than a Schechter function with an exponential term exp( - Mδ) with δ smaller than 1. Changing the Hubble parameter in the range H0 = 67 - 73 km s-1 Mpc-1 or allowing the total neutrino mass to have a value in the range 0 - 0.4 eV causes variations less than the uncertainties. We estimate the fraction of mass locked up in galaxy clusters: about 4.4% of the matter in the Universe is bound in clusters (inside r200) with a mass larger than 1014M⊙ and 14% to clusters and groups with a mass larger than 1013M⊙ at the present Universe. We also discuss the evolution of the galaxy cluster population with redshift. Our results imply that there is hardly any clusters with a mass ≥1015M⊙ above a redshift of z = 1.

  12. Surveying Lab II site

    CERN Document Server

    1974-01-01

    The network of survey reference points on the Lab II site was extended to meet the geodetic needs of the SPS and its North Experimental Area. The work was greatly eased by a geodolite, a measuring instrument on loan from the Fermi Laboratory, which uses a modulated laser beam. (See CERN Courier 14 (1974) p. 247.)

  13. Imaging of star clusters in unperturbed spiral galaxies with the Advanced Camera for Surveys. II. A comparison of star cluster systems in five late type spirals

    NARCIS (Netherlands)

    Mora, M.D.; Larsen, S.S.; Kissler-Patig, M.; Brodie, J.P.; Richtler, T.

    2009-01-01

    Aims. Our goal is to investigate the formation of star clusters in relatively unperturbed environments. To do this, we studied the five nearby spiral galaxies: NGC 45, NGC 1313, NGC 4395, NGC 5236, and NGC 7793. Methods. We obtained images of the galaxies and their star cluster systems in using the

  14. FORS2/VLT survey of Milky Way globular clusters. II. Fe and Mg abundances of 51 Milky Way globular clusters on a homogeneous scale

    Science.gov (United States)

    Dias, B.; Barbuy, B.; Saviane, I.; Held, E. V.; Da Costa, G. S.; Ortolani, S.; Gullieuszik, M.; Vásquez, S.

    2016-05-01

    Context. Globular clusters trace the formation and evolution of the Milky Way and surrounding galaxies, and outline their chemical enrichment history. To accomplish these tasks it is important to have large samples of clusters with homogeneous data and analysis to derive kinematics, chemical abundances, ages and locations. Aims: We obtain homogeneous metallicities and α-element enhancement for 51 Galactic bulge, disc, and halo globular clusters that are among the most distant and/or highly reddened in the Galaxy's globular cluster system. We also provide membership selection based on stellar radial velocities and atmospheric parameters. The implications of our results are discussed. Methods: We observed R ~ 2000 spectra in the wavelength interval 456-586 nm for over 800 red giant stars in 51 Galactic globular clusters. We applied full spectrum fitting with the code ETOILE together with libraries of observed and synthetic spectra. We compared the mean abundances of all clusters with previous work and with field stars. We used the relation between mean metallicity and horizontal branch morphology defined by all clusters to select outliers for discussion. Results: [Fe/H], [Mg/Fe], and [α/Fe] were derived in a consistent way for almost one-third of all Galactic globular clusters. We find our metallicities are comparable to those derived from high-resolution data to within σ = 0.08 dex over the interval -2.5integrated spectroscopy and photometry. Two other clusters, HP 1 and NGC 6558, are confirmed as candidates for the oldest globular clusters in the Milky Way. Conclusions: Stellar spectroscopy in the visible at R ~ 2000 for a large sample of globular clusters is a robust and efficient way to trace the chemical evolution of the host galaxy and to detect interesting objects for follow-up at higher resolution and with forthcoming giant telescopes. The technique used here can also be applied to globular cluster systems in nearby galaxies with current instruments and to

  15. The cosmological analysis of X-ray cluster surveys - II. Application of the CR-HR method to the XMM archive

    Science.gov (United States)

    Clerc, N.; Sadibekova, T.; Pierre, M.; Pacaud, F.; Le Fèvre, J.-P.; Adami, C.; Altieri, B.; Valtchanov, I.

    2012-07-01

    We have processed 2774 high galactic observations from the XMM archive (as of 2010 May) and extracted a serendipitous catalogue of some 850 clusters of galaxies based on purely X-ray criteria, following the methodology developed for the XMM-Large-Scale Survey. Restricting the sample to the highest signal-to-noise ratio objects (347 clusters), we perform a cosmological analysis using only the X-ray information. The analysis consists in the modelling of the observed colour-magnitude [count rate and hardness ratio (CR-HR)] diagram constructed from cluster instrumental count rates measured in the [0.5-2], [1-2] and [0.5-1] keV bands. A Monte Carlo Markov chain procedure simultaneously fits the cosmological parameters, the evolution of the cluster scaling laws and the selection effects. Our results are consistent with the σ8 and Ωm values obtained by the 5-year Wilkinson Microwave Anisotropy Probe (WMAP5) and point towards a negative evolution of the cluster scaling relations with respect to the self-similar expectation. We are further able to constrain the cluster fractional radius xc,0=rc/R500c to xc, 0= 0.24 ± 0.04. This study stresses again the critical role of selection effects in deriving cluster scaling relations, even in the local universe. Finally, we show that the CR-HR method applied to the eRosita all-sky survey - provided that cluster photometric redshifts are available - will enable the determination of the equation of state of the dark energy at the level of the Dark Energy Task Force (DETF) stage IV predictions; simultaneously, the evolution of the cluster scaling relations will be unambiguously determined. The XMM CLuster Archive Super Survey (X-CLASS) serendipitous cluster catalogue is available online at http://xmm-lss.in2p3.fr:8080/l4sdb/ .

  16. Photometric Survey of Galactic Open Clusters (C)

    Science.gov (United States)

    Lee, M. G.; Ann, H. B.; Chun, M. Y.; Kim, S.-L.; Jeon, Y.-B.; Park, B.-G.; Yuk, I.-S.; Sung, H.

    Open clusters are ideal targets with which to investigate the structure and evolution of of the Galatic disk. There are about 1,200 known open clusters in the present catalog of open clusters (Lund Catalog of Open Clusters). To date only one third of them have been studied in detail with photometry. We have started a long-term project to obtain UBVI CCD photometry of open clusters which were little studied before, using the Doyak 1.8 m telescope of the Bohyunsan Observatory in Korea. The size of the field covered with the attached 2K CCD camera is 12'x12'. The primary goals of this project are (1) to make an atlas of open clusters, (2) to make a catalog of UBVI photometry of open clusters, and (3) to survey and monitor variable stars in selected open clusters. When completed, these results will be released to the astronomical community. These results will be very useful (1) for determining basic parameters of the clusters (reddening, distance, metallicity, age, number and types of variable stars), (2) for studying the properties of open cluster variable stars, (3) for investigating the structure and evolution of the Galactic disk, and (4) for understanding the formation, evolution and destruction of open clusters. A progress report of this project will be presented.

  17. SPITZER ULTRA FAINT SURVEY PROGRAM (SURFS UP). II. IRAC-DETECTED LYMAN-BREAK GALAXIES AT 6 ≲ z ≲ 10 BEHIND STRONG-LENSING CLUSTERS

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Kuang-Han; Bradač, Maruša; Hoag, Austin; Cain, Benjamin; Lubin, L. M.; Knight, Robert I. [University of California Davis, 1 Shields Avenue, Davis, CA 95616 (United States); Lemaux, Brian C. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Ryan, R. E. Jr.; Brammer, Gabriel B. [Aix Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, F-13388 Marseille (France); Castellano, Marco; Amorin, Ricardo; Fontana, Adriano; Merlin, Emiliano [INAF—Osservatorio Astronomico di Roma Via Frascati 33, I-00040 Monte Porzio Catone (Italy); Schmidt, Kasper B. [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Schrabback, Tim [Argelander-Institut für Astronomie, Auf Dem Hügel 71, D-53121 Bonn (Germany); Treu, Tommaso [Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095 (United States); Gonzalez, Anthony H. [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611 (United States); Linden, Anja von der, E-mail: khhuang@ucdavis.edu, E-mail: astrokuang@gmail.com [Department of Physics, Stanford University, 382 Via Pueblo Mall, Stanford, CA 94305 (United States)

    2016-01-20

    We study the stellar population properties of the IRAC-detected 6 ≲ z ≲ 10 galaxy candidates from the Spitzer UltRa Faint SUrvey Program. Using the Lyman Break selection technique, we find a total of 17 galaxy candidates at 6 ≲ z ≲ 10 from Hubble Space Telescope images (including the full-depth images from the Hubble Frontier Fields program for MACS 1149 and MACS 0717) that have detections at signal-to-noise ratios  ≥ 3 in at least one of the IRAC 3.6 and 4.5 μm channels. According to the best mass models available for the surveyed galaxy clusters, these IRAC-detected galaxy candidates are magnified by factors of ∼1.2–5.5. Due to the magnification of the foreground galaxy clusters, the rest-frame UV absolute magnitudes M{sub 1600} are between −21.2 and −18.9 mag, while their intrinsic stellar masses are between 2 × 10{sup 8}M{sub ⊙} and 2.9 × 10{sup 9}M{sub ⊙}. We identify two Lyα emitters in our sample from the Keck DEIMOS spectra, one at z{sub Lyα} = 6.76 (in RXJ 1347) and one at z{sub Lyα} = 6.32 (in MACS 0454). We find that 4 out of 17 z ≳ 6 galaxy candidates are favored by z ≲ 1 solutions when IRAC fluxes are included in photometric redshift fitting. We also show that IRAC [3.6]–[4.5] color, when combined with photometric redshift, can be used to identify galaxies which likely have strong nebular emission lines or obscured active galactic nucleus contributions within certain redshift windows.

  18. Cluster II quartet take the stage together

    Science.gov (United States)

    1999-11-01

    This is the only occasion on which all four of ESA's Cluster II spacecraft will be on display together in Europe. Four Spacecraft, One Mission The unique event takes place near the end of the lengthy assembly and test programme, during which each individual spacecraft is being assembled in sequence, one after the other. Two have already completed their assembly and systems testing and are about to be stored in special containers at IABG prior to shipment to the Baikonur launch site in Kazakhstan next spring. In the case of the other two, flight models 5 and 8, installation of the science payloads has finished, but their exhaustive series of environmental tests at IABG have yet to begin. Following delivery to the launch site next April, the satellites will be launched in pairs in June and July 2000. Two Soyuz rockets, each with a newly designed Fregat upper stage, are being provided by the Russian-French Starsem company. This will be the first time ESA satellites have been launched from the former Soviet Union. Cluster II is a replacement for the original Cluster mission, which was lost during the maiden launch of Ariane 5 in June 1996. ESA, given the mission's importance in its overall strategy in the area of the Sun-Earth connection, decided to rebuild this unique project. ESA member states supported that proposal. On 3 April 1997, the Agency's Science Programme Committee agreed. Cluster II was born. European Teamwork Scientific institutions and industrial enterprises in almost all the 14 ESA member states and the United States are taking part in the Cluster II project. Construction of the eight Cluster / Cluster II spacecraft has been a major undertaking for European industry. Built into each 1200 kg satellite are six propellant tanks, two pressure tanks, eight thrusters, 80 metres of pipework, about 5 km of wiring, 380 connectors and more than 14 000 electrical contacts. All the spacecraft were assembled in the giant clean room at the Friedrichshafen plant of

  19. Cluster cosmology with next-generation surveys.

    Science.gov (United States)

    Ascaso, B.

    2017-03-01

    The advent of next-generation surveys will provide a large number of cluster detections that will serve the basis for constraining cos mological parameters using cluster counts. The main two observational ingredients needed are the cluster selection function and the calibration of the mass-observable relation. In this talk, we present the methodology designed to obtain robust predictions of both ingredients based on realistic cosmological simulations mimicking the following next-generation surveys: J-PAS, LSST and Euclid. We display recent results on the selection functions for these mentioned surveys together with others coming from other next-generation surveys such as eROSITA, ACTpol and SPTpol. We notice that the optical and IR surveys will reach the lowest masses between 0.3surveys and introduce very preliminary results.

  20. ChaMP Serendipitous Galaxy Cluster Survey

    Energy Technology Data Exchange (ETDEWEB)

    Barkhouse, Wayne A.; Green, P.J.; Vikhlinin, A.; Kim, D.-W.; Perley, D.; Cameron, R.; Silverman, J.; Mossman, A.; Burenin, R.; Jannuzi, B.T.; Kim, M.; Smith, M.G.; Smith,; Tananbaum, H.; Wilkes, B.J.; /Harvard-Smithsonian Ctr. Astrophys. /UC, Berkeley, Astron. Dept. /SLAC /Garching, Max Planck Inst., MPE /Moscow, Space Res. Inst. /NOAO, Tucson

    2006-04-03

    We present a survey of serendipitous extended X-ray sources and optical cluster candidates from the Chandra Multi-wavelength Project (ChaMP). Our main goal is to make an unbiased comparison of X-ray and optical cluster detection methods. In 130 archival Chandra pointings covering 13 square degrees, we use a wavelet decomposition technique to detect 55 extended sources, of which 6 are nearby single galaxies. Our X-ray cluster catalog reaches a typical flux limit of about {approx} 10{sup -14} erg s{sup -1} cm{sup -2}, with a median cluster core radius of 21''. For 56 of the 130 X-ray fields, we use the ChaMP's deep NOAO/4m MOSAIC g', r', and i' imaging to independently detect cluster candidates using a Voronoi tessellation and percolation (VTP) method. Red-sequence filtering decreases the galaxy fore/background contamination and provides photometric redshifts to z {approx} 0.7. From the overlapping 6.1 square degree X-ray/optical imaging, we find 115 optical clusters (of which 11% are in the X-ray catalog) and 28 X-ray clusters (of which 46% are in the optical VTP catalog). The median redshift of the 13 X-ray/optical clusters is 0.41, and their median X-ray luminosity (0.5-2 keV) is L{sub X} = (2.65 {+-} 0.19) x 10{sup 43} ergs s{sup -1}. The clusters in our sample that are only detected in our optical data are poorer on average ({approx} 4{sigma}) than the X-ray/optically matched clusters, which may partially explain the difference in the detection fractions.

  1. The CAnadian NIRISS Unbiased Cluster Survey (CANUCS)

    Science.gov (United States)

    Ravindranath, Swara; NIRISS GTO Team

    2017-06-01

    CANUCS GTO program is a JWST spectroscopy and imaging survey of five massive galaxy clusters and ten parallel fields using the NIRISS low-resolution grisms, NIRCam imaging and NIRSpec multi-object spectroscopy. The primary goal is to understand the evolution of low mass galaxies across cosmic time. The resolved emission line maps and line ratios for many galaxies, with some at resolution of 100pc via the magnification by gravitational lensing will enable determining the spatial distribution of star formation, dust and metals. Other science goals include the detection and characterization of galaxies within the reionization epoch, using multiply-imaged lensed galaxies to constrain cluster mass distributions and dark matter substructure, and understanding star-formation suppression in the most massive galaxy clusters. In this talk I will describe the science goals of the CANUCS program. The proposed prime and parallel observations will be presented with details of the implementation of the observation strategy using JWST proposal planning tools.

  2. The Open Cluster Chemical Abundances and Mapping (OCCAM) Survey: Optical Extension for Neutron Capture Elements

    Science.gov (United States)

    Melendez, Matthew; O'Connell, Julia; Frinchaboy, Peter M.; Donor, John; Cunha, Katia M. L.; Shetrone, Matthew D.; Majewski, Steven R.; Zasowski, Gail; Pinsonneault, Marc H.; Roman-Lopes, Alexandre; Stassun, Keivan G.; APOGEE Team

    2017-01-01

    The Open Cluster Chemical Abundance & Mapping (OCCAM) survey is a systematic survey of Galactic open clusters using data primarily from the SDSS-III/APOGEE-1 survey. However, neutron capture elements are very limited in the IR region covered by APOGEE. In an effort to fully study detailed Galactic chemical evolution, we are conducting a high resolution (R~60,000) spectroscopic abundance analysis of neutron capture elements for OCCAM clusters in the optical regime to complement the APOGEE results. As part of this effort, we present Ba II, La II, Ce II and Eu II results for a few open clusters without previous abundance measurements using data obtained at McDonald Observatory with the 2.1m Otto Struve telescope and Sandiford Echelle Spectrograph.This work is supported by an NSF AAG grant AST-1311835.

  3. The Survey of Centaurus A's Baryonic Structures (SCABS) - II. The extended globular cluster system of NGC 5128 and its nearby environment

    Science.gov (United States)

    Taylor, Matthew A.; Puzia, Thomas H.; Muñoz, Roberto P.; Mieske, Steffen; Lançon, Ariane; Zhang, Hongxin; Eigenthaler, Paul; Bovill, Mia Sauda

    2017-08-01

    New wide-field u΄g΄r΄I΄z΄ Dark Energy Camera observations centred on the nearby giant elliptical galaxy NGC 5128 covering ˜21 deg2 are used to compile a new catalogue of ˜3200 globular clusters (GCs). We report 2404 newly identified candidates, including the vast majority within ˜140 kpc of NGC 5128. We find evidence for a transition at a galactocentric radius of Rgc ≈ 55 kpc from GCs 'intrinsic' to NGC 5128 to those likely to have been accreted from dwarf galaxies or that may transition to the intragroup medium of the Centaurus A galaxy group. We fit power-law surface number density profiles of the form Σ _{N, R_gc}∝ R_gc^Γ and find that inside the transition radius, the red GCs are more centrally concentrated than the blue, with Γinner, red ≈ -1.78 and Γinner, blue ≈ -1.40, respectively. Outside this region both profiles flatten, more dramatically for the red GCs (Γouter, red ≈ -0.33) compared to the blue (Γouter, blue ≈ -0.61), although the former is more likely to suffer contamination by background sources. The median (g΄ - z΄)0 = 1.27 mag colour of the inner red population is consistent with arising from the amalgamation of two giant galaxies each less luminous than present-day NGC 5128. Both inwards and outwards of the transition radius, we find the fraction of blue GCs to dominate over the red GCs, indicating a lively history of minor mergers. Assuming the blue GCs to originate primarily in dwarf galaxies, we model the population required to explain them, while remaining consistent with NGC 5128's present-day spheroid luminosity. We find that several dozen dwarfs of luminosities Ldw, V ≃ 106-9.3 LV, ⊙, following a Schechter luminosity function with a faint-end slope of -1.50 ≲ α ≲ -1.25 is favoured, many of which may have already been disrupted in NGC 5128's tidal field.

  4. Deep spectroscopy of nearby galaxy clusters - II. The Hercules cluster

    Science.gov (United States)

    Agulli, I.; Aguerri, J. A. L.; Diaferio, A.; Dominguez Palmero, L.; Sánchez-Janssen, R.

    2017-06-01

    We carried out the deep spectroscopic observations of the nearby cluster A 2151 with AF2/WYFFOS@WHT. The caustic technique enables us to identify 360 members brighter than Mr = -16 and within 1.3R200. We separated the members into subsamples according to photometrical and dynamical properties such as colour, local environment and infall time. The completeness of the catalogue and our large sample allow us to analyse the velocity dispersion and the luminosity functions (LFs) of the identified populations. We found evidence of a cluster still in its collapsing phase. The LF of the red population of A 2151 shows a deficit of dwarf red galaxies. Moreover, the normalized LFs of the red and blue populations of A 2151 are comparable to the red and blue LFs of the field, even if the blue galaxies start dominating 1 mag fainter and the red LF is well represented by a single Schechter function rather than a double Schechter function. We discuss how the evolution of cluster galaxies depends on their mass: bright and intermediate galaxies are mainly affected by dynamical friction and internal/mass quenching, while the evolution of dwarfs is driven by environmental processes that need time and a hostile cluster environment to remove the gas reservoirs and halt the star formation.

  5. Stellar Kinematics and Structural Properties of Virgo Cluster Dwarf Early-type Galaxies from the SMAKCED Project. II. The Survey and a Systematic Analysis of Kinematic Anomalies and Asymmetries

    NARCIS (Netherlands)

    Toloba, E.; Guhathakurta, P.; Peletier, R. F.; Boselli, A.; Lisker, T.; Falcón-Barroso, J.; Simon, J. D.; van de Ven, G.; Paudel, S.; Emsellem, E.; Janz, J.; den Brok, M.; Gorgas, J.; Hensler, G.; Laurikainen, E.; Niemi, S.-M.; Ryś, A.; Salo, H.

    2014-01-01

    We present spatially resolved kinematics and global stellar populations and mass-to-light ratios for a sample of 39 dwarf early-type (dE) galaxies in the Virgo cluster studied as part of the SMAKCED stellar absorption-line spectroscopy and imaging survey. This sample is representative of the

  6. Nearby Spiral Galaxy Globular Cluster Systems. II. Globular Cluster Metallicities in NGC 300

    Science.gov (United States)

    Nantais, Julie B.; Huchra, John P.; Barmby, Pauline; Olsen, Knut A. G.

    2010-03-01

    We present new metallicity estimates for globular cluster (GC) candidates in the Sd spiral NGC 300, one of the nearest spiral galaxies outside the Local Group. We have obtained optical spectroscopy for 44 Sculptor Group GC candidates with the Boller and Chivens (B&C) spectrograph on the Baade Telescope at Las Campanas Observatory. There are two GCs in NGC 253 and 12 objects in NGC 300 with globular-cluster-like spectral features, nine of which have radial velocities above 0 km s-1. The remaining three, due to their radial velocities being below the expected 95% confidence limit for velocities of NGC 300 halo objects, are flagged as possible foreground stars. The non-cluster-like candidates included 13 stars, 15 galaxies, and an H II region. One GC, four galaxies, two stars, and the H II region from our sample were identified in archival Hubble Space Telescope images. For the GCs, we measure spectral indices and estimate metallicities using an empirical calibration based on Milky Way GCs. The GCs of NGC 300 appear similar to those of the Milky Way. Excluding possible stars and including clusters from the literature, the GC system (GCS) has a velocity dispersion of 68 km s-1 and has no clear evidence of rotation. The mean metallicity for our full cluster sample plus one literature object is [Fe/H] = -0.94, lying above the relationship between mean GC metallicity and overall galaxy luminosity. Excluding the three low-velocity candidates, we obtain a mean [Fe/H] = -0.98, still higher than expected, raising the possibility of significant foreground star contamination even in this sample. Visual confirmation of genuine GCs using high-resolution space-based imagery could greatly reduce the potential problem of interlopers in small samples of GCSs in low-radial-velocity galaxies. Data for this project were obtained at the Baade 6.5 m telescope, Las Campanas Observatory, Chile. This publication makes use of data products from the Two Micron All Sky Survey, which is a joint

  7. EPR spectroscopy of the manganese cluster of photosystem II.

    Science.gov (United States)

    Haddy, Alice

    2007-06-01

    Electron paramagnetic resonance (EPR) spectroscopy is a valuable tool for understanding the oxidation state and chemical environment of the Mn4Ca cluster of photosystem II. Since the discovery of the multiline signal from the S2 state, EPR spectroscopy has continued to reveal details about the catalytic center of oxygen evolution. At present EPR signals from nearly all of the S-states of the Mn4Ca cluster, as well as from modified and intermediate states, have been observed. This review article describes the various EPR signals obtained from the Mn4Ca cluster, including the metalloradical signals due to interaction of the cluster with a nearby organic radical.

  8. The design effect and cluster samples: optimising tuberculosis prevalence surveys

    NARCIS (Netherlands)

    Williams, B.; Gopi, P. G.; Borgdorff, M. W.; Yamada, N.; Dye, C.

    2008-01-01

    Cross-sectional surveys of disease prevalence, including for tuberculosis (TB), often use a two (or more) stage sampling procedure. By choosing clusters of people randomly from all possible clusters, the logistic costs of doing the survey can be reduced. However, this increases the statistical

  9. Spitzer Survey of the Karin Cluster Asteroids

    NARCIS (Netherlands)

    Harris, Alan W.; Mueller, M.; Lisse, C.; Cheng, A.; Osip, D.

    2007-01-01

    The Karin cluster is one of the youngest known families of main-belt asteroids, dating back to a collisional event only 5.8 Myr ago. Using the Spitzer Space Telescope we have sampled the thermal continua of 17 Karin cluster asteroids, down to the smallest members discovered so far, in order to

  10. Cluster analysis of the hot subdwarfs in the PG survey

    Science.gov (United States)

    Thejll, Peter; Charache, Darryl; Shipman, Harry L.

    1989-01-01

    Application of cluster analysis to the hot subdwarfs in the Palomar Green (PG) survey of faint blue high-Galactic-latitude objects is assessed, with emphasis on data noise and the number of clusters to subdivide the data into. The data used in the study are presented, and cluster analysis, using the CLUSTAN program, is applied to it. Distances are calculated using the Euclidean formula, and clustering is done by Ward's method. The results are discussed, and five groups representing natural divisions of the subdwarfs in the PG survey are presented.

  11. An HI Survey of Clusters in the Local Universe:

    NARCIS (Netherlands)

    van Gorkom, J. H.; Bravo-Alfaro, H.; Dwarakanath, K. S.; Guhathakurta, P.; Poggianti, B. M.; Schiminovich, D.; Valluri, M.; Verheijen, M.; Wilcots, E.; Zabludoff, A.

    2003-01-01

    We outline the project of multifrequency observation of five clusters of galaxies spanning a redshift between 0.05 and 0.2. The core of the project is an HI survey of clusters accomplished with the VLA in its C configuration, and complemented with GMRT data. The 21 cm imaging is being combined with

  12. Galaxy clustering dependence on the [O II] emission line luminosity in the local Universe

    Science.gov (United States)

    Favole, Ginevra; Rodríguez-Torres, Sergio A.; Comparat, Johan; Prada, Francisco; Guo, Hong; Klypin, Anatoly; Montero-Dorta, Antonio D.

    2017-11-01

    We study the galaxy clustering dependence on the [O II] emission line luminosity in the SDSS DR7 Main galaxy sample at mean redshift z ˜ 0.1. We select volume-limited samples of galaxies with different [O II] luminosity thresholds and measure their projected, monopole and quadrupole two-point correlation functions. We model these observations using the 1 h-1 Gpc MultiDark-Planck cosmological simulation and generate light cones with the SUrvey GenerAtoR algorithm. To interpret our results, we adopt a modified (Sub)Halo Abundance Matching scheme, accounting for the stellar mass incompleteness of the emission line galaxies. The satellite fraction constitutes an extra parameter in this model and allows to optimize the clustering fit on both small and intermediate scales (I.e. rp ≲ 30 h-1 Mpc), with no need of any velocity bias correction. We find that, in the local Universe, the [O II] luminosity correlates with all the clustering statistics explored and with the galaxy bias. This latter quantity correlates more strongly with the SDSS r-band magnitude than [O II] luminosity. In conclusion, we propose a straightforward method to produce reliable clustering models, entirely built on the simulation products, which provides robust predictions of the typical ELG host halo masses and satellite fraction values. The SDSS galaxy data, MultiDark mock catalogues and clustering results are made publicly available.

  13. Unsupervised Clustering on Astrophysics Data: Asteroids Reflectance Spectra Surveys and Hyperspectral Images

    Science.gov (United States)

    Galluccio, L.; Michel, O.; Bendjoya, P.; Slezak, E.

    2008-12-01

    We present an original approach to cluster multi-component datasets, in the frame of two applications: taxonomic classification of asteroids and clustering of chemical species on a Mars hyperspectral image. The method is based on an estimation of the number of clusters and an initialization of clusters centroids in order to partition the data with a popular clustering algorithm: K-means. These information are extracted from the construction of a minimal spanning tree (MST) and under the assumption that the vertices are approximately distributed according to a Poisson distribution. We also introduce some recents populars clustering algorithms based on spectral graph theory: spectral clustering methods. Metrics used for measuring similarity between multidimensional data points are based on symmetrical divergences (e.g Kullback-Leibler and RO˝nyi). The use of these informational divergences together with the proposed method leads to better results than some other clustering methods applied to astrophysical data such as: popular reflectance spectra surveys such as Eight Color Asteroid Survey and Small Main Belt Asteroid Spectroscopic Survey II, and hyper-spectral images.

  14. A survey on clustering routing protocols in wireless sensor networks.

    Science.gov (United States)

    Liu, Xuxun

    2012-01-01

    The past few years have witnessed increased interest in the potential use of wireless sensor networks (WSNs) in a wide range of applications and it has become a hot research area. Based on network structure, routing protocols in WSNs can be divided into two categories: flat routing and hierarchical or clustering routing. Owing to a variety of advantages, clustering is becoming an active branch of routing technology in WSNs. In this paper, we present a comprehensive and fine grained survey on clustering routing protocols proposed in the literature for WSNs. We outline the advantages and objectives of clustering for WSNs, and develop a novel taxonomy of WSN clustering routing methods based on complete and detailed clustering attributes. In particular, we systematically analyze a few prominent WSN clustering routing protocols and compare these different approaches according to our taxonomy and several significant metrics. Finally, we summarize and conclude the paper with some future directions.

  15. A Survey on Clustering Routing Protocols in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Xuxun Liu

    2012-08-01

    Full Text Available The past few years have witnessed increased interest in the potential use of wireless sensor networks (WSNs in a wide range of applications and it has become a hot research area. Based on network structure, routing protocols in WSNs can be divided into two categories: flat routing and hierarchical or clustering routing. Owing to a variety of advantages, clustering is becoming an active branch of routing technology in WSNs. In this paper, we present a comprehensive and fine grained survey on clustering routing protocols proposed in the literature for WSNs. We outline the advantages and objectives of clustering for WSNs, and develop a novel taxonomy of WSN clustering routing methods based on complete and detailed clustering attributes. In particular, we systematically analyze a few prominent WSN clustering routing protocols and compare these different approaches according to our taxonomy and several significant metrics. Finally, we summarize and conclude the paper with some future directions.

  16. SPT-GMOS: A Gemini/GMOS-South Spectroscopic Survey of Galaxy Clusters in the SPT-SZ Survey

    Science.gov (United States)

    Bayliss, M. B.; Ruel, J.; Stubbs, C. W.; Allen, S. W.; Applegate, D. E.; Ashby, M. L. N.; Bautz, M.; Benson, B. A.; Bleem, L. E.; Bocquet, S.; Brodwin, M.; Capasso, R.; Carlstrom, J. E.; Chang, C. L.; Chiu, I.; Cho, H.-M.; Clocchiatti, A.; Crawford, T. M.; Crites, A. T.; de Haan, T.; Desai, S.; Dietrich, J. P.; Dobbs, M. A.; Doucouliagos, A. N.; Foley, R. J.; Forman, W. R.; Garmire, G. P.; George, E. M.; Gladders, M. D.; Gonzalez, A. H.; Gupta, N.; Halverson, N. W.; Hlavacek-Larrondo, J.; Hoekstra, H.; Holder, G. P.; Holzapfel, W. L.; Hou, Z.; Hrubes, J. D.; Huang, N.; Jones, C.; Keisler, R.; Knox, L.; Lee, A. T.; Leitch, E. M.; von der Linden, A.; Luong-Van, D.; Mantz, A.; Marrone, D. P.; McDonald, M.; McMahon, J. J.; Meyer, S. S.; Mocanu, L. M.; Mohr, J. J.; Murray, S. S.; Padin, S.; Pryke, C.; Rapetti, D.; Reichardt, C. L.; Rest, A.; Ruhl, J. E.; Saliwanchik, B. R.; Saro, A.; Sayre, J. T.; Schaffer, K. K.; Schrabback, T.; Shirokoff, E.; Song, J.; Spieler, H. G.; Stalder, B.; Stanford, S. A.; Staniszewski, Z.; Stark, A. A.; Story, K. T.; Vanderlinde, K.; Vieira, J. D.; Vikhlinin, A.; Williamson, R.; Zenteno, A.

    2016-11-01

    We present the results of SPT-GMOS, a spectroscopic survey with the Gemini Multi-Object Spectrograph (GMOS) on Gemini South. The targets of SPT-GMOS are galaxy clusters identified in the SPT-SZ survey, a millimeter-wave survey of 2500 deg2 of the southern sky using the South Pole Telescope (SPT). Multi-object spectroscopic observations of 62 SPT-selected galaxy clusters were performed between 2011 January and 2015 December, yielding spectra with radial velocity measurements for 2595 sources. We identify 2243 of these sources as galaxies, and 352 as stars. Of the galaxies, we identify 1579 as members of SPT-SZ galaxy clusters. The primary goal of these observations was to obtain spectra of cluster member galaxies to estimate cluster redshifts and velocity dispersions. We describe the full spectroscopic data set and resulting data products, including galaxy redshifts, cluster redshifts, and velocity dispersions, and measurements of several well-known spectral indices for each galaxy: the equivalent width, W, of [O ii] λλ3727, 3729 and H-δ, and the 4000 Å break strength, D4000. We use the spectral indices to classify galaxies by spectral type (i.e., passive, post-starburst, star-forming), and we match the spectra against photometric catalogs to characterize spectroscopically observed cluster members as a function of brightness (relative to m ⋆). Finally, we report several new measurements of redshifts for ten bright, strongly lensed background galaxies in the cores of eight galaxy clusters. Combining the SPT-GMOS data set with previous spectroscopic follow-up of SPT-SZ galaxy clusters results in spectroscopic measurements for >100 clusters, or ˜20% of the full SPT-SZ sample.

  17. Fuzzy logic based clustering in wireless sensor networks: a survey

    Science.gov (United States)

    Singh, Ashutosh Kumar; Purohit, N.; Varma, S.

    2013-01-01

    Wireless sensor networks (WSNs) have limited resources, thus extending the lifetime has always been an issue of great interest. Recent developments in WSNs have led to various new fuzzy systems, specifically designed for WSNs where energy awareness is an essential consideration. In several applications, the clustered WSN are known to perform better than flat WSN, if the energy consumption in clustering operation itself could be minimised. Routing in clustered WSN is very efficient, especially when the challenge of finding the optimum number of intermediate cluster heads can be resolved. Fortunately, several fuzzy logic based solutions have been proposed for these jobs. Both single- and two-level fuzzy logic approaches are being used for cluster head election in which several distinguished features of WSN have been considered in making a decision. This article surveys the recent fuzzy applications for cluster head selection in WSNs and presents a comparative study for the various approaches pursued.

  18. Optical study of the DAFT/FADA galaxy cluster survey

    Science.gov (United States)

    Martinet, N.; Durret, F.; Clowe, D.; Adami, C.

    2013-11-01

    DAFT/FADA (Dark energy American French Team) is a large survey of ˜90 high redshift (0.42×10^{14} M_{⊙}) clusters with HST weak lensing oriented data, plus BVRIZJ 4m ground based follow up to compute photometric redshifts. The main goals of this survey are to constrain dark energy parameters using weak lensing tomography and to study a large homogeneous sample of high redshift massive clusters. We will briefly review the latest results of this optical survey, focusing on two ongoing works: the calculation of galaxy luminosity functions from photometric redshift catalogs and the weak lensing analysis of ground based data.

  19. The C4 clustering algorithm: Clusters of galaxies in the Sloan Digital Sky Survey

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Christopher J.; Nichol, Robert; Reichart, Dan; Wechsler, Risa H.; Evrard, August; Annis, James; McKay, Timothy; Bahcall, Neta; Bernardi, Mariangela; Boehringer,; Connolly, Andrew; Goto, Tomo; Kniazev, Alexie; Lamb, Donald; Postman, Marc; Schneider, Donald; Sheth, Ravi; Voges, Wolfgang; /Cerro-Tololo InterAmerican Obs. /Portsmouth U.,

    2005-03-01

    We present the ''C4 Cluster Catalog'', a new sample of 748 clusters of galaxies identified in the spectroscopic sample of the Second Data Release (DR2) of the Sloan Digital Sky Survey (SDSS). The C4 cluster-finding algorithm identifies clusters as overdensities in a seven-dimensional position and color space, thus minimizing projection effects that have plagued previous optical cluster selection. The present C4 catalog covers {approx}2600 square degrees of sky and ranges in redshift from z = 0.02 to z = 0.17. The mean cluster membership is 36 galaxies (with redshifts) brighter than r = 17.7, but the catalog includes a range of systems, from groups containing 10 members to massive clusters with over 200 cluster members with redshifts. The catalog provides a large number of measured cluster properties including sky location, mean redshift, galaxy membership, summed r-band optical luminosity (L{sub r}), velocity dispersion, as well as quantitative measures of substructure and the surrounding large-scale environment. We use new, multi-color mock SDSS galaxy catalogs, empirically constructed from the {Lambda}CDM Hubble Volume (HV) Sky Survey output, to investigate the sensitivity of the C4 catalog to the various algorithm parameters (detection threshold, choice of passbands and search aperture), as well as to quantify the purity and completeness of the C4 cluster catalog. These mock catalogs indicate that the C4 catalog is {approx_equal}90% complete and 95% pure above M{sub 200} = 1 x 10{sup 14} h{sup -1}M{sub {circle_dot}} and within 0.03 {le} z {le} 0.12. Using the SDSS DR2 data, we show that the C4 algorithm finds 98% of X-ray identified clusters and 90% of Abell clusters within 0.03 {le} z {le} 0.12. Using the mock galaxy catalogs and the full HV dark matter simulations, we show that the L{sub r} of a cluster is a more robust estimator of the halo mass (M{sub 200}) than the galaxy line-of-sight velocity dispersion or the richness of the cluster

  20. The sloan digital sky survey-II supernova survey

    DEFF Research Database (Denmark)

    Frieman, Joshua A.; Bassett, Bruce; Becker, Andrew

    2008-01-01

    The Sloan Digital Sky Survey-II (SDSS-II) has embarked on a multi-year project to identify and measure light curves for intermediate-redshift (0.05 Type Ia supernovae (SNe Ia) using repeated five-band (ugriz) imaging over an area of 300 sq. deg. The survey region is a stripe 2.5° wide...... the first two seasons, each region was imaged on average every five nights. Spectroscopic follow-up observations to determine supernova type and redshift are carried out on a large number of telescopes. In its first two three-month seasons, the survey has discovered and measured light curves for 327...... spectroscopically confirmed SNe Ia, 30 probable SNe Ia, 14 confirmed SNe Ib/c, 32 confirmed SNe II, plus a large number of photometrically identified SNe Ia, 94 of which have host-galaxy spectra taken so far. This paper provides an overview of the project and briefly describes the observations completed during...

  1. Hα star formation rates of z > 1 galaxy clusters in the IRAC shallow cluster survey

    Energy Technology Data Exchange (ETDEWEB)

    Zeimann, Gregory R.; Stanford, S. A. [Department of Physics, University of California, One Shields Avenue, Davis, CA 95616 (United States); Brodwin, Mark [University of Missouri-Kansas City, Kansas City, MO 64110 (United States); Gonzalez, Anthony H.; Mancone, Conor [Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States); Snyder, Gregory F. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Stern, Daniel; Eisenhardt, Peter [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Dey, Arjun [NOAO, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Moustakas, John [Department of Physics and Astronomy, Siena College, 515 Loudon Road, Loudonville, NY 12211 (United States)

    2013-12-20

    We present Hubble Space Telescope near-IR spectroscopy for 18 galaxy clusters at 1.0 Cluster Survey. We use Wide Field Camera 3 grism data to spectroscopically identify Hα emitters in both the cores of galaxy clusters as well as in field galaxies. We find a large cluster-to-cluster scatter in the star formation rates within a projected radius of 500 kpc, and many of our clusters (∼60%) have significant levels of star formation within a projected radius of 200 kpc. A stacking analysis reveals that dust reddening in these star-forming galaxies is positively correlated with stellar mass and may be higher in the field than the cluster at a fixed stellar mass. This may indicate a lower amount of gas in star-forming cluster galaxies than in the field population. Also, Hα equivalent widths of star-forming galaxies in the cluster environment are still suppressed below the level of the field. This suppression is most significant for lower mass galaxies (log M {sub *} < 10.0 M {sub ☉}). We therefore conclude that environmental effects are still important at 1.0 clusters with log M {sub *} ≲ 10.0 M {sub ☉}.

  2. Intracluster light at the Frontier - II. The Frontier Fields Clusters

    Science.gov (United States)

    Montes, Mireia; Trujillo, Ignacio

    2018-02-01

    Multiwavelength deep observations are a key tool to understand the origin of the diffuse light in clusters of galaxies: the intracluster light (ICL). For this reason, we take advantage of the Hubble Frontier Fields (HFF) survey to investigate the properties of the stellar populations of the ICL of its six massive intermediate redshift (0.3 1015 M⊙) clusters is formed by the stripping of MW-like objects that have been accreted at z < 1, in agreement with current simulations. We do not find any significant increase in the fraction of light of the ICL with cosmic time, although the redshift range explored is narrow to derive any strong conclusion. When exploring the slope of the stellar mass density profile, we found that the ICL of the HFF clusters follows the shape of their underlying dark matter haloes, in agreement with the idea that the ICL is the result of the stripping of galaxies at recent times.

  3. Intrinsic alignment in redMaPPer clusters - II. Radial alignment of satellites towards cluster centres

    Science.gov (United States)

    Huang, Hung-Jin; Mandelbaum, Rachel; Freeman, Peter E.; Chen, Yen-Chi; Rozo, Eduardo; Rykoff, Eli

    2018-03-01

    We study the orientations of satellite galaxies in redMaPPer clusters constructed from the Sloan Digital Sky Survey at 0.1 statistically significant level when limiting to a subsample of higher luminosity satellites. We further investigate the impact of noise, systematics, and real physical isophotal twisting effects in the comparison between the SA signal detected via different shape measurement methods. Unlike previous studies, which only consider the dependence of SA on a few parameters, here we explore a total of 17 galaxy and cluster properties, using a statistical model averaging technique to naturally account for parameter correlations and identify significant SA predictors. We find that the measured SA signal is strongest for satellites with the following characteristics: higher luminosity, smaller distance to the cluster centre, rounder in shape, higher bulge fraction, and distributed preferentially along the major axis directions of their centrals. Finally, we provide physical explanations for the identified dependences and discuss the connection to theories of SA.

  4. A SURVEY FOR PLANETARY NEBULAE IN M31 GLOBULAR CLUSTERS

    Energy Technology Data Exchange (ETDEWEB)

    Jacoby, George H. [Giant Magellan Telescope/Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Ciardullo, Robin [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); De Marco, Orsola [Department of Physics and Astronomy, Macquarie University, Sydney, NSW 2109 (Australia); Lee, Myung Gyoon [Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of); Herrmann, Kimberly A. [Lowell Observatory, Flagstaff, AZ 86001 (United States); Hwang, Ho Seong; Davies, James E. [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Kaplan, Evan, E-mail: gjacoby@gmto.org, E-mail: rbc@astro.psu.edu, E-mail: orsola.demarco@mq.edu.au, E-mail: mglee@astrog.snu.ac.kr, E-mail: herrmann@lowell.edu, E-mail: hhwang@cfa.harvard.edu, E-mail: jdavies@cfa.harvard.edu, E-mail: evanskaplan@gmail.com [Vassar College, 124 Raymond Ave., Poughkeepsie, NY 12604 (United States)

    2013-05-20

    We report the results of an [O III] {lambda}5007 spectroscopic survey for planetary nebulae (PNe) located within the star clusters of M31. By examining R {approx} 5000 spectra taken with the WIYN+Hydra spectrograph, we identify 3 PN candidates in a sample of 274 likely globular clusters, 2 candidates in objects which may be globular clusters, and 5 candidates in a set of 85 younger systems. The possible PNe are all faint, between {approx}2.5 and {approx}6.8 mag down the PN luminosity function, and, partly as a consequence of our selection criteria, have high excitation, with [O III] {lambda}5007 to H{beta} ratios ranging from 2 to {approx}> 12. We discuss the individual candidates, their likelihood of cluster membership, and the possibility that they were formed via binary interactions within the clusters. Our data are consistent with the suggestion that PN formation within globular clusters correlates with binary encounter frequency, though, due to the small numbers and large uncertainties in the candidate list, this study does not provide sufficient evidence to confirm the hypothesis.

  5. STELLAR KINEMATICS AND STRUCTURAL PROPERTIES OF VIRGO CLUSTER DWARF EARLY-TYPE GALAXIES FROM THE SMAKCED PROJECT. II. THE SURVEY AND A SYSTEMATIC ANALYSIS OF KINEMATIC ANOMALIES AND ASYMMETRIES

    Energy Technology Data Exchange (ETDEWEB)

    Toloba, E.; Guhathakurta, P. [UCO/Lick Observatory, University of California, Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States); Peletier, R. F. [Kapteyn Astronomical Institute, Postbus 800, 9700 AV Groningen (Netherlands); Boselli, A. [Laboratoire d' Astrophysique de Marseille-LAM, Université d' Aix-Marseille and CNRS, UMR 7326, 38 rue F. Joliot-Curie, 13388 Marseille Cedex 13 (France); Lisker, T. [Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Mönchhofstraße 12-14, D-69120 Heidelberg (Germany); Falcón-Barroso, J.; Ryś, A. [Instituto de Astrofísica de Canarias, Vía Láctea s/n, La Laguna, Tenerife (Spain); Simon, J. D. [Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Van de Ven, G. [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Paudel, S. [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of); Emsellem, E. [European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748, Garching (Germany); Janz, J. [Centre for Astrophysics and Supercomputing, Swinburne University, Hawthorn, VIC 3122 (Australia); Den Brok, M. [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States); Gorgas, J. [Departamento de Astrofísica y Física de la Atmósfera, Universidad Complutense de Madrid, E-28040, Madrid (Spain); Hensler, G. [Department of Astrophysics, University of Vienna, Türkenschanzstraße 17, 1180 Vienna (Austria); Laurikainen, E.; Salo, H. [Division of Astronomy, Department of Physics, PO Box 3000, FI-90014 University of Oulu (Finland); Niemi, S.-M., E-mail: toloba@ucolick.org [Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey RH5 6NT (United Kingdom)

    2015-01-01

    We present spatially resolved kinematics and global stellar populations and mass-to-light ratios for a sample of 39 dwarf early-type (dE) galaxies in the Virgo cluster studied as part of the SMAKCED stellar absorption-line spectroscopy and imaging survey. This sample is representative of the early-type population in the Virgo cluster in the absolute magnitude range –19.0 < M{sub r} < –16.0 and of all morphological subclasses found in this galaxy population. For each dE, we measure the rotation curve and velocity dispersion profile and fit an analytic function to the rotation curve. We study the significance of the departure of the rotation curve from the best-fit analytic function (poorly fit) and of the difference between the approaching and receding sides of the rotation curve (asymmetry). Our sample includes two dEs with kinematically decoupled cores that have been previously reported. We find that 62 ± 8% (23 out of the 39) of the dEs have a significant anomaly in their rotation curve. Analysis of the images reveals photometric anomalies for most galaxies. However, there is no clear correlation between the significance of the photometric and kinematic anomalies. We measure age-sensitive (H{sub β} and H{sub γA}) and metallicity sensitive (Fe4668 and Mgb) Lick spectral indices in the LIS-5 Å system. This population of galaxies exhibits a wide range of ages and metallicities; we also find that 4 dEs show clear evidence of emission partially filling in the Balmer absorption lines. Finally, we estimate the total masses and dark matter fractions of the dEs and plot them in the mass-size, the mass-velocity dispersion, and the fundamental plane scaling relations. The dEs seem to be the bridge between massive early-type galaxies and dSphs, and have a median total mass within the R{sub e} of log M{sub e} = 9.1 ± 0.2 and a median dark matter fraction within the R{sub e} of f {sub DM} = 46 ± 18%. Any formation model for the dE galaxy class must account for this

  6. Clustering and community detection in directed networks: A survey

    Science.gov (United States)

    Malliaros, Fragkiskos D.; Vazirgiannis, Michalis

    2013-12-01

    Networks (or graphs) appear as dominant structures in diverse domains, including sociology, biology, neuroscience and computer science. In most of the aforementioned cases graphs are directed - in the sense that there is directionality on the edges, making the semantics of the edges nonsymmetric as the source node transmits some property to the target one but not vice versa. An interesting feature that real networks present is the clustering or community structure property, under which the graph topology is organized into modules commonly called communities or clusters. The essence here is that nodes of the same community are highly similar while on the contrary, nodes across communities present low similarity. Revealing the underlying community structure of directed complex networks has become a crucial and interdisciplinary topic with a plethora of relevant application domains. Therefore, naturally there is a recent wealth of research production in the area of mining directed graphs - with clustering being the primary method sought and the primary tool for community detection and evaluation. The goal of this paper is to offer an in-depth comparative review of the methods presented so far for clustering directed networks along with the relevant necessary methodological background and also related applications. The survey commences by offering a concise review of the fundamental concepts and methodological base on which graph clustering algorithms capitalize on. Then we present the relevant work along two orthogonal classifications. The first one is mostly concerned with the methodological principles of the clustering algorithms, while the second one approaches the methods from the viewpoint regarding the properties of a good cluster in a directed network. Further, we present methods and metrics for evaluating graph clustering results, demonstrate interesting application domains and provide promising future research directions.

  7. The Richness Dependence of Galaxy Cluster Correlations: Results From A Redshift Survey Of Rich APM Clusters

    Science.gov (United States)

    Croft, R. A. C.; Dalton, G. B.; Efstathiou, G.; Sutherland, W. J.; Maddox, S. J.

    1997-01-01

    We analyze the spatial clustering properties of a new catalog of very rich galaxy clusters selected from the APM Galaxy Survey. These clusters are of comparable richness and space density to Abell Richness Class greater than or equal to 1 clusters, but selected using an objective algorithm from a catalog demonstrably free of artificial inhomogeneities. Evaluation of the two-point correlation function xi(sub cc)(r) for the full sample and for richer subsamples reveals that the correlation amplitude is consistent with that measured for lower richness APM clusters and X-ray selected clusters. We apply a maximum likelihood estimator to find the best fitting slope and amplitude of a power law fit to x(sub cc)(r), and to estimate the correlation length r(sub 0) (the value of r at which xi(sub cc)(r) is equal to unity). For clusters with a mean space density of 1.6 x 10(exp -6) h(exp 3) MpC(exp -3) (equivalent to the space density of Abell Richness greater than or equal to 2 clusters), we find r(sub 0) = 21.3(+11.1/-9.3) h(exp -1) Mpc (95% confidence limits). This is consistent with the weak richness dependence of xi(sub cc)(r) expected in Gaussian models of structure formation. In particular, the amplitude of xi(sub cc)(r) at all richnesses matches that of xi(sub cc)(r) for clusters selected in N-Body simulations of a low density Cold Dark Matter model.

  8. The SEGUE Stellar Parameter Pipeline. II. Validation with Galactic Globular and Open Clusters

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Y.S.; Beers, T.C.; Sivarani, T.; Johnson, J.A.; An, D.; Wilhelm, R.; Prieto, C.Allende; Koesterke, L.; Re Fiorentin, P.; Bailer-Jones, C.A.L.; Norris, J.E.

    2007-10-01

    The authors validate the performance and accuracy of the current SEGUE (Sloan Extension for Galactic Understanding and Exploration) Stellar Parameter Pipeline (SSPP), which determines stellar atmospheric parameters (effective temperature, surface gravity, and metallicity) by comparing derived overall metallicities and radial velocities from selected likely members of three globular clusters (M 13, M 15, and M 2) and two open clusters (NGC 2420 and M 67) to the literature values. Spectroscopic and photometric data obtained during the course of the original Sloan Digital Sky Survey (SDSS-1) and its first extension (SDSS-II/SEGUE) are used to determine stellar radial velocities and atmospheric parameter estimates for stars in these clusters. Based on the scatter in the metallicities derived for the members of each cluster, they quantify the typical uncertainty of the SSPP values, {sigma}([Fe/H]) = 0.13 dex for stars in the range of 4500 K {le} T{sub eff} {le} 7500 K and 2.0 {le} log g {le} 5.0, at least over the metallicity interval spanned by the clusters studied (-2.3 {le} [Fe/H] < 0). The surface gravities and effective temperatures derived by the SSPP are also compared with those estimated from the comparison of the color-magnitude diagrams with stellar evolution models; they find satisfactory agreement. At present, the SSPP underestimates [Fe/H] for near-solar-metallicity stars, represented by members of M 67 in this study, by {approx} 0.3 dex.

  9. The XMM Cluster Survey: A Massive Galaxy Cluster at z = 1.45

    Energy Technology Data Exchange (ETDEWEB)

    Stanford, S A; Romer, A K; Sabirli, K; Davidson, M; Hilton, M; Viana, P P; Collins, C A; Kay, S T; Liddle, A R; Mann, R G; Miller, C J; Nichol, R C; West, M J; Conselice, C J; Spinrad, H; Stern, D; Bundy, K

    2006-05-24

    We report the discovery of XMMXCS J2215.9-1738, a massive galaxy cluster at z = 1.45, which was found in the XMM Cluster Survey. The cluster candidate was initially identified as an extended X-ray source in archival XMM data. Optical spectroscopy shows that 6 galaxies within a {approx}60 arcsec diameter region lie at z = 1.45 {+-} 0.01. Model fits to the X-ray spectra of the extended emission yield kT = 7.4{sub -1.8}{sup +2.7} keV (90% confidence); if there is an undetected central X-ray point source then kT = 6.5{sub -1.8}{sup +2.6} keV. The bolometric X-ray luminosity is L{sub x} = 4.4{sub -0.6}{sup +0.8} x 10{sup 44} ergs s{sup -1} over a 2 Mpc radial region. The measured T{sub x}, which is the highest for any known cluster at z > 1, suggests that this cluster is relatively massive for such a high redshift. The redshift of XMMXCS J2215.9-1738 is the highest currently known for a spectroscopically-confirmed cluster of galaxies.

  10. AMICO: optimized detection of galaxy clusters in photometric surveys

    Science.gov (United States)

    Bellagamba, Fabio; Roncarelli, Mauro; Maturi, Matteo; Moscardini, Lauro

    2018-02-01

    We present Adaptive Matched Identifier of Clustered Objects (AMICO), a new algorithm for the detection of galaxy clusters in photometric surveys. AMICO is based on the Optimal Filtering technique, which allows to maximize the signal-to-noise ratio (S/N) of the clusters. In this work, we focus on the new iterative approach to the extraction of cluster candidates from the map produced by the filter. In particular, we provide a definition of membership probability for the galaxies close to any cluster candidate, which allows us to remove its imprint from the map, allowing the detection of smaller structures. As demonstrated in our tests, this method allows the deblending of close-by and aligned structures in more than 50 per cent of the cases for objects at radial distance equal to 0.5 × R200 or redshift distance equal to 2 × σz, being σz the typical uncertainty of photometric redshifts. Running AMICO on mocks derived from N-body simulations and semi-analytical modelling of the galaxy evolution, we obtain a consistent mass-amplitude relation through the redshift range of 0.3 slope of ∼0.55 and a logarithmic scatter of ∼0.14. The fraction of false detections is steeply decreasing with S/N and negligible at S/N > 5.

  11. SURVEY ON CLUSTERING ALGORITHM AND SIMILARITY MEASURE FOR CATEGORICAL DATA

    Directory of Open Access Journals (Sweden)

    S. Anitha Elavarasi

    2014-01-01

    Full Text Available Learning is the process of generating useful information from a huge volume of data. Learning can be either supervised learning (e.g. classification or unsupervised learning (e.g. Clustering Clustering is the process of grouping a set of physical objects into classes of similar object. Objects in real world consist of both numerical and categorical data. Categorical data are not analyzed as numerical data because of the absence of inherit ordering. This paper describes about ten different clustering algorithms, its methodology and the factors influencing its performance. Each algorithm is evaluated using real world datasets and its pro and cons are specified. The various similarity / dissimilarity measure applied to categorical data and its performance is also discussed. The time complexity defines the amount of time taken by an algorithm to perform the elementary operation. The time complexity of various algorithms are discussed and its performance on real world data such as mushroom, zoo, soya bean, cancer, vote, car and iris are measured. In this survey Cluster Accuracy and Error rate for four different clustering algorithm (K-modes, fuzzy K-modes, ROCK and Squeezer, two different similarity measure (DISC and Overlap and DILCA applied for hierarchy and partition algorithm are evaluated.

  12. The ATLASGAL survey: The sample of young massive cluster progenitors

    Science.gov (United States)

    Csengeri, T.; Bontemps, S.; Wyrowski, F.; Megeath, S. T.; Motte, F.; Sanna, A.; Wienen, M.; Menten, K. M.

    2017-05-01

    Context. The progenitors of high-mass stars and clusters are still challenging to recognise. Only unbiased surveys, sensitive to compact regions of high dust column density, can unambiguously reveal such a small population of particularly massive and cold clumps. Aims: Here we use the ATLASGAL survey to identify a sample of candidate progenitors of massive clusters in the inner Galaxy. Methods: We characterise a flux limited sample of compact sources selected from the ATLASGAL survey. Sensitive mid-infrared data at 21-24μm from the WISE and MIPSGAL surveys were explored to search for embedded objects, and complementary spectroscopic data were used to investigate their stability and their star formation activity. Results: We identify an unbiased sample of infrared-quiet massive clumps in the Galaxy that potentially represent the earliest stages of massive cluster formation. An important fraction of this sample consists of sources that have not been studied in detail before. We first find that clumps hosting more evolved embedded objects and infrared-quiet clumps exhibit similar physical properties in terms of mass and size, suggesting that the sources are not only capable of forming high-mass stars, but likely also follow a single evolutionary track leading to the formation of massive clusters. The majority of the clumps are likely not in virial-equilibrium, suggesting collapse on the clump scale. Conclusions: We identify the precursors of the most massive clusters in the Galaxy within our completeness limit, and argue that these objects are undergoing large-scale collapse. This is in line with the low number of infrared-quiet massive clumps and earlier findings that star formation, in particular for high-mass objects is a fast, dynamic process. We propose a scenario in which massive clumps start to fragment and collapse before their final mass is accumulated indicating that strong self-gravity and global collapse is needed to build up rich clusters and the most

  13. The next generation Virgo cluster survey. VIII. The spatial distribution of globular clusters in the Virgo cluster

    Energy Technology Data Exchange (ETDEWEB)

    Durrell, Patrick R.; Accetta, Katharine [Department of Physics and Astronomy, Youngstown State University, Youngstown, OH 44555 (United States); Côté, Patrick; Blakeslee, John P.; Ferrarese, Laura; McConnachie, Alan; Gwyn, Stephen [Herzberg Astronomy and Astrophysics, National Research Council, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Peng, Eric W.; Zhang, Hongxin [Department of Astronomy, Peking University, Beijing 100871 (China); Mihos, J. Christopher [Department of Astronomy, Case Western Reserve University, Cleveland, OH 44106 (United States); Puzia, Thomas H.; Jordán, Andrés [Institute of Astrophysics, Pontificia Universidad Catolica, Av. Vicu' a Mackenna 4860, Macul 7820436, Santiago (Chile); Lançon, Ariane [Observatoire astronomique de Strasbourg, Université de Strasbourg, CNRS, UMR 7550, 11 rue de l' Université, F-67000 Strasbourg (France); Liu, Chengze [Center for Astronomy and Astrophysics, Department of Physics and Astronomy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Cuillandre, Jean-Charles [Canada-France-Hawaii Telescope Corporation, Kamuela, HI 96743 (United States); Boissier, Samuel; Boselli, Alessandro [Aix Marseille Université, CNRS, LAM (Laboratoire d' Astrophysique de Marseille) UMR 7326, F-13388 Marseille (France); Courteau, Stéphane [Department of Physics, Engineering Physics and Astronomy, Queen' s University, Kingston, ON K7L 3N6 (Canada); Duc, Pierre-Alain [AIM Paris Saclay, CNRS/INSU, CEA/Irfu, Université Paris Diderot, Orme des Merisiers, F-91191 Gif sur Yvette cedex (France); Emsellem, Eric [Université de Lyon 1, CRAL, Observatoire de Lyon, 9 av. Charles André, F-69230 Saint-Genis Laval (France); CNRS, UMR 5574, ENS de Lyon (France); and others

    2014-10-20

    We report on a large-scale study of the distribution of globular clusters (GCs) throughout the Virgo cluster, based on photometry from the Next Generation Virgo Cluster Survey (NGVS), a large imaging survey covering Virgo's primary subclusters (Virgo A = M87 and Virgo B = M49) out to their virial radii. Using the g{sub o}{sup ′}, (g' – i') {sub o} color-magnitude diagram of unresolved and marginally resolved sources within the NGVS, we have constructed two-dimensional maps of the (irregular) GC distribution over 100 deg{sup 2} to a depth of g{sub o}{sup ′} = 24. We present the clearest evidence to date showing the difference in concentration between red and blue GCs over the full extent of the cluster, where the red (more metal-rich) GCs are largely located around the massive early-type galaxies in Virgo, while the blue (metal-poor) GCs have a much more extended spatial distribution with significant populations still present beyond 83' (∼215 kpc) along the major axes of both M49 and M87. A comparison of our GC maps to the diffuse light in the outermost regions of M49 and M87 show remarkable agreement in the shape, ellipticity, and boxiness of both luminous systems. We also find evidence for spatial enhancements of GCs surrounding M87 that may be indicative of recent interactions or an ongoing merger history. We compare the GC map to that of the locations of Virgo galaxies and the X-ray intracluster gas, and find generally good agreement between these various baryonic structures. We calculate the Virgo cluster contains a total population of N {sub GC} = 67, 300 ± 14, 400, of which 35% are located in M87 and M49 alone. For the first time, we compute a cluster-wide specific frequency S {sub N,} {sub CL} = 2.8 ± 0.7, after correcting for Virgo's diffuse light. We also find a GC-to-baryonic mass fraction ε {sub b} = 5.7 ± 1.1 × 10{sup –4} and a GC-to-total cluster mass formation efficiency ε {sub t} = 2.9 ± 0.5 × 10{sup –5

  14. Redshift-space correlation functions in large galaxy cluster surveys

    Science.gov (United States)

    Valageas, P.; Clerc, N.

    2012-11-01

    Context. Large ongoing and upcoming galaxy cluster surveys in the optical, X-ray and millimetric wavelengths will provide rich samples of galaxy clusters at unprecedented depths. One key observable for constraining cosmological models is the correlation function of these objects, measured through their spectroscopic redshift. Aims: We study the redshift-space correlation functions of clusters of galaxies, averaged over finite redshift intervals, and their covariance matrices. Expanding as usual the angular anisotropy of the redshift-space correlation on Legendre polynomials, we consider the redshift-space distortions of the monopole as well as the next two multipoles, 2ℓ = 2 and 4. Methods: Taking into account the Kaiser effect, we developed an analytical formalism to obtain explicit expressions of all contributions to these mean correlations and covariance matrices. We include shot-noise and sample-variance effects as well as Gaussian and non-Gaussian contributions. Results: We obtain a reasonable agreement with numerical simulations for the mean correlations and covariance matrices on large scales (r > 10 h-1 Mpc). Redshift-space distortions amplify the monopole correlation by about 10-20%, depending on the halo mass, but the signal-to-noise ratio remains of the same order as for the real-space correlation. This distortion will be significant for surveys such as DES, Erosita, and Euclid, which should also measure the quadrupole 2ℓ = 2. The third multipole, 2ℓ = 4, may only be marginally detected by Euclid.

  15. Dynamics of cD clusters of galaxies. II: Analysis of seven Abell clusters

    Science.gov (United States)

    Oegerle, William R.; Hill, John M.

    1994-01-01

    We have investigated the dynamics of the seven Abell clusters A193, A399, A401, A1795, A1809, A2063, and A2124, based on redshift data reported previously by us (Hill & Oegerle, (1993)). These papers present the initial results of a survey of cD cluster kinematics, with an emphasis on studying the nature of peculiar velocity cD galaxies and their parent clusters. In the current sample, we find no evidence for significant peculiar cD velocities, with respect to the global velocity distribution. However, the cD in A2063 has a significant (3 sigma) peculiar velocity with respect to galaxies in the inner 1.5 Mpc/h, which is likely due to the merger of a subcluster with A2063. We also find significant evidence for subclustering in A1795, and a marginally peculiar cD velocity with respect to galaxies within approximately 200 kpc/h of the cD. The available x-ray, optical, and galaxy redshift data strongly suggest that a subcluster has merged with A1795. We propose that the subclusters which merged with A1795 and A2063 were relatively small, with shallow potential wells, so that the cooling flows in these clusters were not disrupted. Two-body gravitational models of the A399/401 and A2063/MKW3S systems indicate that A399/401 is a bound pair with a total virial mass of approximately 4 x 10(exp 15) solar mass/h, while A2063 and MKW3S are very unlikely to be bound.

  16. THE NEXT GENERATION VIRGO CLUSTER SURVEY (NGVS). I. INTRODUCTION TO THE SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Ferrarese, Laura; Cote, Patrick; Gwyn, S. D. J.; MacArthur, Lauren A.; McConnachie, Alan W.; Blakeslee, John P. [Herzberg Institute of Astrophysics, National Research Council of Canada, Victoria, BC, V9E 2E7 (Canada); Cuillandre, Jean-Charles [Canada-France-Hawaii Telescope Corporation, Kamuela, HI 96743 (United States); Peng, Eric W. [Department of Astronomy, Peking University, Beijing 100871 (China); Duc, Pierre-Alain [AIM Paris Saclay, CNRS/INSU, CEA/Irfu, Universite Paris Diderot, Orme des Merisiers, F-91191 Gif sur Yvette cedex (France); Boselli, A. [Laboratoire d' Astrophysique de Marseille, UMR 6110 CNRS, 38 rue F. Joliot-Curie, F-13388 Marseille (France); Mei, Simona [GEPI, Observatoire de Paris, CNRS, 5 Place Jules Jannssen, F-92195 Meudon (France); Erben, Thomas [Argelander-Institut fuer Astronomie, University of Bonn, Auf dem Huegel 71, D-53121 Bonn (Germany); Durrell, Patrick R. [Department of Physics and Astronomy, Youngstown State University, Youngstown, OH (United States); Christopher Mihos, J. [Department of Astronomy, Case Western Reserve University, Cleveland, OH (United States); Jordan, Andres; Puzia, Thomas H. [Departamento de Astronomia y Astrofisica, Pontificia Universidad Catolica de Chile, 7820436 Macul, Santiago (Chile); Lancon, Ariane [Observatoire Astronomique, Universite de Strasbourg and CNRS UMR 7550, 11 rue de l' Universite, F-67000 Strasbourg (France); Emsellem, Eric [Universite de Lyon 1, CRAL, Observatoire de Lyon, 9 av. Charles Andre, F-69230 Saint-Genis Laval (France); CNRS, UMR 5574, ENS de Lyon (France); Balogh, Michael L. [Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada); Van Waerbeke, Ludovic [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, B.C., V6T 1Z1 (Canada); and others

    2012-05-01

    The Next Generation Virgo Cluster Survey (NGVS) is a program that uses the 1 deg{sup 2} MegaCam instrument on the Canada-France-Hawaii Telescope to carry out a comprehensive optical imaging survey of the Virgo cluster, from its core to its virial radius-covering a total area of 104 deg{sup 2}-in the u*griz bandpasses. Thanks to a dedicated data acquisition strategy and processing pipeline, the NGVS reaches a point-source depth of g Almost-Equal-To 25.9 mag (10{sigma}) and a surface brightness limit of {mu}{sub g} {approx} 29 mag arcsec{sup -2} (2{sigma} above the mean sky level), thus superseding all previous optical studies of this benchmark galaxy cluster. In this paper, we give an overview of the technical aspects of the survey, such as areal coverage, field placement, choice of filters, limiting magnitudes, observing strategies, data processing and calibration pipelines, survey timeline, and data products. We also describe the primary scientific topics of the NGVS, which include: the galaxy luminosity and mass functions; the color-magnitude relation; galaxy scaling relations; compact stellar systems; galactic nuclei; the extragalactic distance scale; the large-scale environment of the cluster and its relationship to the Local Supercluster; diffuse light and the intracluster medium; galaxy interactions and evolutionary processes; and extragalactic star clusters. In addition, we describe a number of ancillary programs dealing with 'foreground' and 'background' science topics, including the study of high-inclination trans-Neptunian objects; the structure of the Galactic halo in the direction of the Virgo Overdensity and Sagittarius Stream; the measurement of cosmic shear, galaxy-galaxy, and cluster lensing; and the identification of distant galaxy clusters, and strong-lensing events.

  17. Survey of Clustering based Financial Fraud Detection Research

    Directory of Open Access Journals (Sweden)

    Andrei Sorin SABAU

    2012-01-01

    Full Text Available Given the current global economic context, increasing efforts are being made to both prevent and detect fraud. This is a natural response to the ascendant trend in fraud activities recorded in the last couple of years, with a 13% increase only in 2011. Due to ever increasing volumes of data needed to be analyzed, data mining methods and techniques are being used more and more often. One domain data mining can excel at, suspicious transaction monitoring, has emerged for the first time as the most effective fraud detection method in 2011. Out of the available data mining techniques, clustering has proven itself a constant applied solution for detecting fraud. This paper surveys clustering techniques used in fraud detection over the last ten years, shortly reviewing each one.

  18. Cross-correlation Weak Lensing of SDSS galaxy Clusters II: Cluster Density Profiles and the Mass--Richness Relation

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, David E.; Sheldon, Erin S.; Wechsler, Risa H.; Rozo, Eduardo; Koester, Benjamin P.; Frieman, Joshua A.; McKay, Timothy A.; Evrard, August E.; Becker, Matthew; Annis, James

    2007-09-28

    We interpret and model the statistical weak lensing measurements around 130,000 groups and clusters of galaxies in the Sloan Digital Sky Survey presented by Sheldon et al. (2007). We present non-parametric inversions of the 2D shear profiles to the mean 3D cluster density and mass profiles in bins of both optical richness and cluster i-band luminosity. Since the mean cluster density profile is proportional to the cluster-mass correlation function, the mean profile is spherically symmetric by the assumptions of large-scale homogeneity and isotropy. We correct the inferred 3D profiles for systematic effects, including non-linear shear and the fact that cluster halos are not all precisely centered on their brightest galaxies. We also model the measured cluster shear profile as a sum of contributions from the brightest central galaxy, the cluster dark matter halo, and neighboring halos. We infer the relations between mean cluster virial mass and optical richness and luminosity over two orders of magnitude in cluster mass; the virial mass at fixed richness or luminosity is determined with a precision of {approx} 13% including both statistical and systematic errors. We also constrain the halo concentration parameter and halo bias as a function of cluster mass; both are in good agreement with predictions from N-body simulations of LCDM models. The methods employed here will be applicable to deeper, wide-area optical surveys that aim to constrain the nature of the dark energy, such as the Dark Energy Survey, the Large Synoptic Survey Telescope and space-based surveys.

  19. In vivo cluster formation of nisin and Lipid II is correlated with membrane depolarization

    NARCIS (Netherlands)

    Tol, Menno B; Angeles, Danae Morales; Scheffers, Dirk-Jan

    2015-01-01

    Nisin and related lantibiotics kill bacteria by pore formation, or by sequestering Lipid II. Some lantibiotics sequester Lipid II into clusters, which were suggested to kill cells through delocalized peptidoglycan synthesis. Here, we show that cluster formation is always concomitant with (i)

  20. Calix[4]arene supported clusters: a dimer of [Mn(III)Mn(II)] dimers

    DEFF Research Database (Denmark)

    Taylor, Stephanie M; McIntosh, Ruaraidh D; Beavers, Christine M

    2011-01-01

    Phosphinate ligands allow for the transformation of a calix[4]arene supported [Mn(III)(2)Mn(II)(2)] tetramer cluster motif into an unusual [Mn(III)Mn(II)](2) dimer of dimers; the clusters self-assemble in the crystal to form bi-layer arrays reminiscent of the typical packing of calixarene solvates....

  1. Measuring the Ultimate Halo Mass of Galaxy Clusters: Redshifts and Mass Profiles from the Hectospec Cluster Survey (HeCS)

    Science.gov (United States)

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

    2013-04-01

    The infall regions of galaxy clusters represent the largest gravitationally bound structures in a ΛCDM universe. Measuring cluster mass profiles into the infall regions provides an estimate of the ultimate mass of these halos. We use the caustic technique to measure cluster mass profiles from galaxy redshifts obtained with the Hectospec Cluster Survey (HeCS), an extensive spectroscopic survey of galaxy clusters with MMT/Hectospec. We survey 58 clusters selected by X-ray flux at 0.1 noise spectra for ~200 cluster members and a comparable number of foreground/background galaxies. The cluster members trace out infall patterns around the clusters. The members define a very narrow red sequence. We demonstrate that the determination of velocity dispersion is insensitive to the inclusion of bluer members (a small fraction of the cluster population). We apply the caustic technique to define membership and estimate the mass profiles to large radii. The ultimate halo mass of clusters (the mass that remains bound in the far future of a ΛCDM universe) is on average (1.99 ± 0.11)M 200, a new observational cosmological test in essential agreement with simulations. Summed profiles binned in M 200 and in LX demonstrate that the predicted Navarro-Frenk-White form of the density profile is a remarkably good representation of the data in agreement with weak lensing results extending to large radius. The concentration of these summed profiles is also consistent with theoretical predictions.

  2. A faint galaxy redshift survey behind massive clusters

    Energy Technology Data Exchange (ETDEWEB)

    Frye, Brenda Louise [Univ. of California, Berkeley, CA (United States)

    1999-05-01

    This thesis is concerned with the gravitational lensing effect by massive galaxy clusters. We have explored a new technique for measuring galaxy masses and for detecting high-z galaxies by their optical colors. A redshift survey has been obtained at the Keck for a magnitude limited sample of objects (I<23) behind three clusters, A1689, A2390, and A2218 within a radius of 0.5M pc. For each cluster we see both a clear trend of increasing flux and redshift towards the center. This behavior is the result of image magnifications, such that at fixed redshift one sees further down the luminosity function. The gradient of this magnification is, unlike measurements of image distortion, sensitive to the mass profile, and found to depart strongly from a pure isothermal halo. We have found that V RI color selection can be used effectively as a discriminant for finding high-z galaxies behind clusters and present five 4.1 < z < 5.1 spectra which are of very high quality due to their high mean magnification of ~20, showing strong, visibly-saturated interstellar metal lines in some cases. We have also investigated the radio ring lens PKS 1830-211, locating the source and multiple images and detected molecular absorption at mm wavelengths. Broad molecular absorption of width 1/40kms is found toward the southwest component only, where surprisingly it does not reach the base of the continuum, which implies incomplete coverage of the SW component by molecular gas, despite the small projected size of the source, less than 1/8h pc at the absorption redshift.

  3. Extragalactic jets as probes of distant clusters of galaxies and the clusters occupied by bent radio AGN (COBRA) survey

    Science.gov (United States)

    Blanton, Elizabeth L.; Paterno-Mahler, Rachel; Wing, Joshua D.; Ashby, M. L. N.; Golden-Marx, Emmet; Brodwin, Mark; Douglass, E. M.; Randall, Scott W.; Clarke, T. E.

    2015-03-01

    We are conducting a large survey of distant clusters of galaxies using radio sources with bent jets and lobes as tracers. These radio sources are driven by AGN and achieve their bent morphologies through interaction with the surrounding gas found in clusters of galaxies. Based on low-redshift studies, these types of sources can be used to identify clusters very efficiently. We present initial results from our survey of 653 bent-double radio sources with optical hosts too faint to appear in the SDSS. The sample was observed in the infrared with Spitzer, and it has revealed ~200 distant clusters or proto-clusters in the redshift range z ~ 0.7 - 3.0. The sample of bent-doubles contains both quasars and radio galaxies enabling us to study both radiative and kinetic mode feedback in cluster and group environments at a wide range of redshifts.

  4. Radio AGN in 13,240 galaxy clusters from the Sloan Digital Sky Survey

    Energy Technology Data Exchange (ETDEWEB)

    Croft, S; de Vries, W; Becker, R

    2007-05-30

    We correlate the positions of 13,240 Brightest Cluster Galaxies (BCGs) with 0.1 {le} z {le} 0.3 from the maxBCG catalog with radio sources from the FIRST survey to study the sizes and distributions of radio AGN in galaxy clusters. We find that 19.7% of our BCGs are radio-loud, and this fraction depends on the stellar mass of the BCG, and to a lesser extent on the richness of the parent cluster (in the sense of increasing radio loudness with increasing mass). The intrinsic size of the radio emission associated with the BCGs peaks at 55 kpc, with a tail extending to 200 kpc. The radio power of the extended sources places them on the divide between FR I and FR II type sources, while sources compact in the radio tend to be somewhat less radio-luminous. We also detect an excess of radio sources associated with the cluster, instead of with the BCG itself, extending out to {approx} 1.4 kpc.

  5. Characterization of the galactic white dwarf population in the next generation Virgo Cluster survey

    Science.gov (United States)

    Fantin, Nicholas

    Halo white dwarfs remain one of the least studied stellar populations in the Milky Way because of their faint luminosities. Recent work has uncovered a population of hot white dwarfs which are thought to be remnants of low-mass Population II stars. This thesis uses optical data from the Next Generation Virgo Cluster Survey (NGVS) and ultravoilet data from the GALEX Ultraviolet Virgo Cluster Survey (GUViCS) to select candidates which may belong to this population of recently formed halo white dwarfs. A colour selection was used to separate white dwarfs from QSOs and main-sequence stars. Photometric distances are calculated using model colour-absolute magnitude relations. Proper motions are calculated by using the difference in positions between objects from the Sloan Digital Sky Survey and the NGVS. The proper motions are combined with the calculated photometric distances to calculate tangential velocities, as well as approximate Galactic space velocities. White dwarf candidates are characterized as belonging to either the disk or the halo using a variety of methods, including calculated scale heights (z> 1 kpc), tangential velocities (vt >200 km/s), and their location in (V,U) space. The 20 halo white dwarf candidates which were selected using Galactic space velocities are analyzed, and their colours and temperatures suggest that these objects represent some of the youngest white dwarfs in the Galactic halo.

  6. Galaxy Clusters in the Swift/BAT era II: 10 more Clusters detected above 15 keV

    Energy Technology Data Exchange (ETDEWEB)

    Ajello, M.; /SLAC /KIPAC, Menlo Park; Rebusco, P.; /KIPAC, Menlo Park; Cappelluti, N.; /Garching, Max Planck Inst., MPE /Maryland U., Baltimore County; Reimer, O.; /SLAC /Palermo Observ.; Boehringer, H.; /Garching, Max Planck Inst., MPE; La Parola, V.; Cusumano, G.; /Palermo Observ.

    2010-10-27

    We report on the discovery of 10 additional galaxy clusters detected in the ongoing Swift/BAT all-sky survey. Among the newly BAT-discovered clusters there are: Bullet, Abell 85, Norma, and PKS 0745-19. Norma is the only cluster, among those presented here, which is resolved by BAT. For all the clusters we perform a detailed spectral analysis using XMM-Newton and Swift/BAT data to investigate the presence of a hard (non-thermal) X-ray excess. We find that in most cases the clusters emission in the 0.3-200 keV band can be explained by a multi-temperature thermal model confirming our previous results. For two clusters (Bullet and Abell 3667) we find evidence for the presence of a hard X-ray excess. In the case of the Bullet cluster, our analysis confirms the presence of a non-thermal, power-law like, component with a 20-100 keV flux of 3.4 x 10{sup -12} erg cm{sup -2} s{sup -1} as detected in previous studies. For Abell 3667 the excess emission can be successfully modeled as a hot component (kT = {approx}13 keV). We thus conclude that the hard X-ray emission from galaxy clusters (except the Bullet) has most likely thermal origin.

  7. Comparison of nano-sized Mn oxides with the Mn cluster of photosystem II as catalysts for water oxidation.

    Science.gov (United States)

    Najafpour, Mohammad Mahdi; Ghobadi, Mohadeseh Zarei; Haghighi, Behzad; Tomo, Tatsuya; Shen, Jian-Ren; Allakhverdiev, Suleyman I

    2015-02-01

    "Back to Nature" is a promising way to solve the problems that we face today, such as air pollution and shortage of energy supply based on conventional fossil fuels. A Mn cluster inside photosystem II catalyzes light-induced water-splitting leading to the generation of protons, electrons and oxygen in photosynthetic organisms, and has been considered as a good model for the synthesis of new artificial water-oxidizing catalysts. Herein, we surveyed the structural and functional details of this cluster and its surrounding environment. Then, we review the mechanistic findings concerning the cluster and compare this biological catalyst with nano-sized Mn oxides, which are among the best artificial Mn-based water-oxidizing catalysts. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. The CLASS blazar survey - II. Optical properties

    NARCIS (Netherlands)

    Caccianiga, A; Marcha, MJ; Anton, S; Mack, KH; Neeser, MJ

    2002-01-01

    This paper presents the optical properties of the objects selected in the CLASS blazar survey. Because an optical spectrum is now available for 70 per cent of the 325 sources present in the sample, a spectral classification, based on the appearance of the emission/absorption lines, is possible. A

  9. The ACS survey of Galactic globular clusters - XIV. Bayesian single-population analysis of 69 globular clusters

    Science.gov (United States)

    Wagner-Kaiser, R.; Sarajedini, A.; von Hippel, T.; Stenning, D. C.; van Dyk, D. A.; Jeffery, E.; Robinson, E.; Stein, N.; Anderson, J.; Jefferys, W. H.

    2017-06-01

    We use Hubble Space Telescope (HST) imaging from the ACS Treasury Survey to determine fits for single population isochrones of 69 Galactic globular clusters. Using robust Bayesian analysis techniques, we simultaneously determine ages, distances, absorptions and helium values for each cluster under the scenario of a 'single' stellar population on model grids with solar ratio heavy element abundances. The set of cluster parameters is determined in a consistent and reproducible manner for all clusters using the Bayesian analysis suite BASE-9. Our results are used to re-visit the age-metallicity relation. We find correlations with helium and several other parameters such as metallicity, binary fraction and proxies for cluster mass. The helium abundances of the clusters are also considered in the context of carbon, nitrogen, and oxygen abundances and the multiple population scenario.

  10. Characterizing the W40 Cluster Region with the UKIDSS Galactic Plane Survey

    Science.gov (United States)

    Yu, Ka Chun; Shuping, Ralph

    2018-01-01

    W40 is a region of thermal radio continuum emission in the Aquila Rift, and is one of only a few high-mass star forming regions within 1 kpc of the Sun. We use the Galactic Plane Survey from the UKIDDS Data Release 10 in JHK to study the stellar population in a 30' x 30' field centered on the W40 star-forming region. With imaging deeper than previous surveys (down to a depth of K=18), we identify ~1500 stars with K-band excess that are likely young stars with protostellar disks (Class II-III), more than has been found in previous surveys of this region. We use the NIR photometry of ~50,000 stars to create a high resolution 0.5' optical extinction map, which is used in conjunction with nearby control fields to assess contamination by background sources. Like in previous studies, we find an embedded cluster of reddened sources centered on the handful of late-O/early-B type stars at the center of W40. We fit their spatial distribution using a 2D gaussian profile with $\\sigma$ ~ 1' (0.37 pc at a distance of 440 pc), and a central stellar density of 510 stars/pc^2. After removing foreground stars, we identify 217 total stars within $3\\sigma$ of the cluster center, of which ~100 have K-band excess indicative of Class II-III YSOs, consistent with previous work. We discuss possible background contamination as well as the spatial distribution of young stars throughout the region.

  11. Investigating Faculty Familiarity with Assessment Terminology by Applying Cluster Analysis to Interpret Survey Data

    Science.gov (United States)

    Raker, Jeffrey R.; Holme, Thomas A.

    2014-01-01

    A cluster analysis was conducted with a set of survey data on chemistry faculty familiarity with 13 assessment terms. Cluster groupings suggest a high, middle, and low overall familiarity with the terminology and an independent high and low familiarity with terms related to fundamental statistics. The six resultant clusters were found to be…

  12. Exploring the expansion dynamics of the universe from galaxy cluster surveys

    Science.gov (United States)

    Wang, Deng; Meng, Xin-He

    2017-12-01

    To understand the expansion dynamics of the universe from galaxy cluster scales, using the angular diameter distance (ADD) data from two different galaxy cluster surveys, we constrain four cosmological models to explore the underlying value of H0 and employ the model-independent Gaussian Processes to investigate the evolution of the equation of state of dark energy. The ADD data in the X-ray bands consists of two samples covering the redshift ranges [0.023, 0.784] and [0.14, 0.89], respectively. We find that: (i) For these two samples, the obtained values of H0 are more consistent with the recent local observation by Riess et al. than the global measurement by the Planck Collaboration, and the ΛCDM model is still preferred utilizing the information criterions; (ii) For the first sample, there is no evidence of dynamical dark energy (DDE) at the 2 σ confidence level (CL); (iii) For the second one, the reconstructed equation of state of dark energy exhibits a phantom-crossing behavior in the relatively low redshift range over the 2 σ CL, which gives a hint that the late-time universe may be actually dominated by the DDE from galaxy cluster scales; (iv) By adding a combination of Type Ia Supernovae, cosmic chronometers and Planck-2015 shift parameter and HII galaxy measurements into both ADD samples, the DDE exists evidently over the 2 σ CL.

  13. Coupled Cluster in Condensed Phase. Part II: Liquid Hydrogen Fluoride from Quantum Cluster Equilibrium Theory.

    Science.gov (United States)

    Spickermann, Christian; Perlt, Eva; von Domaros, Michael; Roatsch, Martin; Friedrich, Joachim; Kirchner, Barbara

    2011-04-12

    Treating the bulk phase with high-level ab initio methods, such as coupled cluster, is a nontrivial task because of the computational costs of these electronic structure methods. In this part of our hydrogen fluoride study we make use of the quantum cluster equilibrium method, which employs electronic structure input of small clusters and combines it with simple statistical mechanics in order to describe condensed phase phenomena. If no parameter adjustment is applied, then the lower quantum chemical methods, such as density functional theory in conjunction with the generalized gradient approximation, provide wrong results in accordance with the description of the strength of the interaction in the clusters. While density functional theory describes the liquid phase too dense due to overbinding of the clusters, the coupled cluster method and the perturbation theory at the complete basis set limit agree well with experimental observations. If we allow the two parameters in the quantum cluster equilibrium method to vary, then these are able to compensate the overbinding, thereby leading to very good agreement with experiment. Correlated methods in combination with small basis sets giving rise to too weakly bound clusters cannot reach this accuracy even if the parameters are flexible. Only at the complete basis set limit, the performance of the correlated methods is again excellent.

  14. Pajarito Plateau archaeological surveys and excavations. II

    Energy Technology Data Exchange (ETDEWEB)

    Steen, C R

    1982-04-01

    Los Alamos National Laboratory continues its archaeological program of data gathering and salvage excavations. Sites recently added to the archaeological survey are described, as well as the results of five excavations. Among the more interesting and important discoveries are (1) the apparently well-established local use of anhydrous lime, and (2) a late pre-Columbian use of earlier house sites and middens for garden plots. Evidence indicated that the local puebloan population was the result of an expansion of upper Rio Grande peoples, not an influx of migrants.

  15. Type ia Supernovae Rates and Galaxy Clustering from the CFHT Supernova Legacy Survey

    Science.gov (United States)

    Graham, M. L.; Pritchet, C. J.; Sullivan, M.; Gwyn, S. D. J.; Neill, J. D.; Hsiao, E. Y.; Astier, P.; Balam, D.; Balland, C.; Basa, S.; Carlberg, R. G.; Conley, A.; Fouchez, D.; Guy, J.; Hardin, D.; Hook, I. M.; Howell, D. A.; Pain, R.; Perrett, K.; Regnault, N.; Baumont, S.; LeDu, J.; Lidman, C.; Perlmutter, S.; Ripoche, P.; Suzuki, N.; Walker, E. S.; Zhang, T.

    2008-04-01

    The Canada-France-Hawaii Telescope Supernova Legacy Survey (CFHT SNLS) has created a large homogeneous database of intermediate redshift (0.2 z influence of galaxy clustering on the SN Ia rate, over and above the expected effect due to the dependence of SFR on clustering through the morphology-density relation. We identify three cluster SNe Ia, plus three additional possible cluster SNe Ia, and find the SN Ia rate per unit mass in clusters at intermediate redshifts is consistent with the rate per unit mass in field early-type galaxies and the SN Ia cluster rate from low-redshift cluster targeted surveys. We also find the number of SNe Ia in cluster environments to be within a factor of 2 of expectations from the two-component SN Ia rate model.

  16. PHAT STELLAR CLUSTER SURVEY. I. YEAR 1 CATALOG AND INTEGRATED PHOTOMETRY

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, L. Clifton; Dalcanton, Julianne J.; Fouesneau, Morgan; Hodge, Paul W.; Weisz, Daniel R.; Williams, Benjamin F.; Beerman, Lori C. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Seth, Anil C. [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States); Caldwell, Nelson [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Gouliermis, Dimitrios A. [Institut fuer Theoretische Astrophysik, Zentrum fuer Astronomie der Universitaet Heidelberg, Albert-Ueberle-Strasse 2, D-69120 Heidelberg (Germany); Larsen, Soren S. [Department of Astrophysics, IMAPP, Radboud University Nijmegen, P.O. Box 9010, 6500 GL Nijmegen (Netherlands); Olsen, Knut A. G. [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); San Roman, Izaskun; Sarajedini, Ata [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611-2055 (United States); Bianchi, Luciana [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Dolphin, Andrew E. [Raytheon Company, 1151 East Hermans Road, Tucson, AZ 85756 (United States); Girardi, Leo [Osservatorio Astronomico di Padova-INAF, Vicolo dell' Osservatorio 5, I-35122 Padova (Italy); Guhathakurta, Puragra [Department of Astronomy and Astrophysics, University of California Observatories/Lick Observatory, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States); Kalirai, Jason [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Lang, Dustin, E-mail: lcjohnso@astro.washington.edu [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); and others

    2012-06-20

    The Panchromatic Hubble Andromeda Treasury (PHAT) survey is an ongoing Hubble Space Telescope (HST) multi-cycle program to obtain high spatial resolution imaging of one-third of the M31 disk at ultraviolet through near-infrared wavelengths. In this paper, we present the first installment of the PHAT stellar cluster catalog. When completed, the PHAT cluster catalog will be among the largest and most comprehensive surveys of resolved star clusters in any galaxy. The exquisite spatial resolution achieved with HST has allowed us to identify hundreds of new clusters that were previously inaccessible with existing ground-based surveys. We identify 601 clusters in the Year 1 sample, representing more than a factor of four increase over previous catalogs within the current survey area (390 arcmin{sup 2}). This work presents results derived from the first {approx}25% of the survey data; we estimate that the final sample will include {approx}2500 clusters. For the Year 1 objects, we present a catalog with positions, radii, and six-band integrated photometry. Along with a general characterization of the cluster luminosities and colors, we discuss the cluster luminosity function, the cluster size distributions, and highlight a number of individually interesting clusters found in the Year 1 search.

  17. The CfA-Rosat Survey of Distant Clusters of Galaxies

    Science.gov (United States)

    McNamara, Brian

    1998-01-01

    We (Vikhlinin, McNamara, Forman, Jones, Hornstrup, Quintana) have completed a new survey of distant clusters of galaxies, which we use to to study cluster evolution over cosmological timescales. The clusters were identified as extended X-ray sources in 650 ROSAT PSPC images of high Galactic latitude fields. Our catalog of approximately 230 extended X-ray sources covers 160 square degrees on the sky. Ours is the largest of the several ROSAT serendipitous cluster surveys in progress (e.g. SHARC, Rosati, WARPS etc.). Using V,R,I imagery obtained at several observatories, we find that greater than 90% of the X-ray sources are associated with distant clusters of galaxies. We have obtained spectroscopic redshifts for nearly 80 clusters in our catalog, and we have measured photometric redshifts for the remaining clusters. Our sample contains more than 20 clusters at z > 0.5. I will discuss the logN-logS relationship for our clusters. Because our large survey area, we are able to confirm the evolution of the most luminous distant clusters first seen in the Einstein Extended Medium Sensitivity Survey. In addition, I will discuss the relationships between optical richness, core radius, and X-ray luminosity for distant, X-ray-selected clusters.

  18. nIFTy galaxy cluster simulations II: radiative models

    CSIR Research Space (South Africa)

    Sembolini, F

    2016-04-01

    Full Text Available We have simulated the formation of a massive galaxy cluster (M(supcrit)(sub200) = 1.1×10(sup15)h(sup-1)M) in a CDM universe using 10 different codes (RAMSES, 2 incarnations of AREPO and 7 of GADGET), modeling hydrodynamics with full radiative...

  19. The Two-Point Correlation Function of Rich Clusters of Galaxies: Results from an Extended APM Cluster Redshift Survey

    OpenAIRE

    G. B. Dalton; Croft, R. A. C.; Efstathiou, G.; Sutherland, W.J.; Maddox, S. J.; Davis, M.

    1994-01-01

    We present new estimates of the spatial two-point correlation function of rich clusters of galaxies selected from the APM Galaxy Survey. We have measured redshifts for a sample of $364$ clusters out to a depth of $\\sim 450\\hmpc$. The clusters have a mean space density of $\\bar{n} = 3.4\\times 10^{-5}\\hmpccc$. The two-point correlation function, $\\xi_{cc}$, for this sample is equal to unity at a pair-separation of $r_0 = 14.3\\pm1.75\\hmpc$ (2$\\sigma$ errors), consistent with our earlier results ...

  20. Choosing a Cluster Sampling Design for Lot Quality Assurance Sampling Surveys.

    Science.gov (United States)

    Hund, Lauren; Bedrick, Edward J; Pagano, Marcello

    2015-01-01

    Lot quality assurance sampling (LQAS) surveys are commonly used for monitoring and evaluation in resource-limited settings. Recently several methods have been proposed to combine LQAS with cluster sampling for more timely and cost-effective data collection. For some of these methods, the standard binomial model can be used for constructing decision rules as the clustering can be ignored. For other designs, considered here, clustering is accommodated in the design phase. In this paper, we compare these latter cluster LQAS methodologies and provide recommendations for choosing a cluster LQAS design. We compare technical differences in the three methods and determine situations in which the choice of method results in a substantively different design. We consider two different aspects of the methods: the distributional assumptions and the clustering parameterization. Further, we provide software tools for implementing each method and clarify misconceptions about these designs in the literature. We illustrate the differences in these methods using vaccination and nutrition cluster LQAS surveys as example designs. The cluster methods are not sensitive to the distributional assumptions but can result in substantially different designs (sample sizes) depending on the clustering parameterization. However, none of the clustering parameterizations used in the existing methods appears to be consistent with the observed data, and, consequently, choice between the cluster LQAS methods is not straightforward. Further research should attempt to characterize clustering patterns in specific applications and provide suggestions for best-practice cluster LQAS designs on a setting-specific basis.

  1. Cluster randomised trials in the medical literature: two bibliometric surveys

    Directory of Open Access Journals (Sweden)

    Bland J Martin

    2004-08-01

    Full Text Available Abstract Background Several reviews of published cluster randomised trials have reported that about half did not take clustering into account in the analysis, which was thus incorrect and potentially misleading. In this paper I ask whether cluster randomised trials are increasing in both number and quality of reporting. Methods Computer search for papers on cluster randomised trials since 1980, hand search of trial reports published in selected volumes of the British Medical Journal over 20 years. Results There has been a large increase in the numbers of methodological papers and of trial reports using the term 'cluster random' in recent years, with about equal numbers of each type of paper. The British Medical Journal contained more such reports than any other journal. In this journal there was a corresponding increase over time in the number of trials where subjects were randomised in clusters. In 2003 all reports showed awareness of the need to allow for clustering in the analysis. In 1993 and before clustering was ignored in most such trials. Conclusion Cluster trials are becoming more frequent and reporting is of higher quality. Perhaps statistician pressure works.

  2. The High-Redshift Clusters Occupied by Bent Radio AGN (COBRA) Survey

    Science.gov (United States)

    Paterno-Mahler, Rachel; Blanton, Elizabeth L.; Wing, Joshua; Ashby, M. L. N.; Brodwin, Mark; Golden-Marx, Emmet

    The number of confirmed, high-redshift galaxy clusters is very low compared to the number of well-studied clusters nearby. Bent, double-lobed radio sources are frequently found in galaxy clusters, and thus can be used as tracers for efficiently locating high-redshift clusters. Using our Spitzer Snapshot Survey, we have identified approximately 300 potential new clusters with redshifts 0.7 COBRA) survey. We have created color-magnitude diagrams using infrared and optical data. Using the colors of the radio source host and the red sequence we can estimate redshifts for our clusters, as well as examine the evolution of the cluster galaxies over a large range of cosmic time.

  3. RASS-SDSS Galaxy cluster survey. IV. A ubiquitous dwarf galaxy population in clusters

    Science.gov (United States)

    Popesso, P.; Biviano, A.; Böhringer, H.; Romaniello, M.

    2006-01-01

    We analyze the Luminosity Functions (LFs) of a subsample of 69 clusters from the RASS-SDSS galaxy cluster catalog. When calculated within the cluster physical sizes, given by r200 or r500, all the cluster LFs appear to have the same shape, well fitted by a composite of two Schechter functions with a marked upturn and a steepening at the faint-end. Previously reported cluster-to-cluster variations of the LF faint-end slope are due to the use of a metric cluster aperture for computing the LF of clusters of different masses. We determine the composite LF for early- and late-type galaxies, where the typing is based on the galaxy u-r colors. The late-type LF is well fitted by a single Schechter function with a steep slope (α=-2.0 in the r band, within r200). The early-type LF instead cannot be fitted by a single Schechter function, and a composite of two Schechter functions is needed. The faint-end upturn of the global cluster LF is due to the early-type cluster galaxies. The shape of the bright-end tail of the early-type LF does not seem to depend upon the local galaxy density or the distance from the cluster center. The late-type LF shows a significant variation only very near the cluster center. On the other hand, the faint-end tail of the early-type LF shows a significant and continuous variation with the environment. We provide evidence that the process responsible for creating the excess population of dwarf early type galaxies in clusters is a threshold process that occurs when the density exceeds ˜ 500 times the critical density of the Universe. We interpret our results in the context of the "harassment" scenario, where faint early-type cluster galaxies are predicted to be the descendants of tidally-stripped late-type galaxies.

  4. Confronting the sound speed of dark energy with future cluster surveys

    DEFF Research Database (Denmark)

    Basse, Tobias; Eggers Bjaelde, Ole; Hannestad, Steen

    2012-01-01

    Future cluster surveys will observe galaxy clusters numbering in the hundred thousands. We consider this work how these surveys can be used to constrain dark energy parameters: in particular, the equation of state parameter w and the non-adiabatic sound speed c_s^2. We demonstrate that, in combin......Future cluster surveys will observe galaxy clusters numbering in the hundred thousands. We consider this work how these surveys can be used to constrain dark energy parameters: in particular, the equation of state parameter w and the non-adiabatic sound speed c_s^2. We demonstrate that......, then c_s^2 can be pinned down to within an order of magnitude. In the course of this work, we also investigate the process of dark energy virialisation in the presence of an arbitrary sound speed. We find that dark energy clustering and virialisation can lead to dark energy contributing to the total...

  5. A Survey of Popular R Packages for Cluster Analysis

    Science.gov (United States)

    Flynt, Abby; Dean, Nema

    2016-01-01

    Cluster analysis is a set of statistical methods for discovering new group/class structure when exploring data sets. This article reviews the following popular libraries/commands in the R software language for applying different types of cluster analysis: from the stats library, the kmeans, and hclust functions; the mclust library; the poLCA…

  6. SURVEY OF GROSS ALPHA AND BETA RADIOACTIVITY ii WELL ...

    African Journals Online (AJOL)

    2005-07-03

    Jul 3, 2005 ... SURVEY OF GROSS ALPHA AND BETA RADIOACTIVITY ii. WELL WATER FROM ZARIA AND ITS ENVIRONS. R. A. Onoja, T. C. Akpa", S. P. Mallam and l. G. E. lbeanu, . Health Physics and Radiation Biophysics Section,. Centre for Energy Research and Training, Ahmadu Bel/o University, Zaria, Nigeria.

  7. A Near-infrared Survey of the Rosette Complex: Clues of Early Cluster Evolution

    Science.gov (United States)

    Román-Zúñiga, Carlos G.; Lada, Elizabeth A.; Ferreira, Bruno

    2008-05-01

    The majority of stars in our galaxy are born in embedded clusters, which can be considered the fundamental units of star formation. We have recently surveyed the star forming content of the Rosette Complex using FLAMINGOS in order to investigate the properties of its embedded clusters. We discuss the results of our near-infrared imaging survey. In particular, we on the first evidence for the early evolution and expansion of the embedded clusters. In addition we present data suggesting a temporal sequence of cluster formation across the cloud and discuss the influence of the HII region on the star forming history of the Rosette.

  8. A Survey on Node Clustering in Cognitive Radio Wireless Sensor Networks.

    Science.gov (United States)

    Joshi, Gyanendra Prasad; Kim, Sung Won

    2016-09-10

    Cognitive radio wireless sensor networks (CR-WSNs) have attracted a great deal of attention recently due to the emerging spectrum scarcity issue. This work attempts to provide a detailed analysis of the role of node clustering in CR-WSNs. We outline the objectives, requirements, and advantages of node clustering in CR-WSNs. We describe how a CR-WSN with node clustering differs from conventional wireless sensor networks, and we discuss its characteristics, architecture, and topologies. We survey the existing clustering algorithms and compare their objectives and features. We suggest how clustering issues and challenges can be handled.

  9. The Effects of Halo Assembly Bias on Self-Calibration in Galaxy Cluster Surveys

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Hao-Yi; Rozo, Eduardo; Wechsler, Risa H.

    2008-08-07

    Self-calibration techniques for analyzing galaxy cluster counts utilize the abundance and the clustering amplitude of dark matter halos. These properties simultaneously constrain cosmological parameters and the cluster observable-mass relation. It was recently discovered that the clustering amplitude of halos depends not only on the halo mass, but also on various secondary variables, such as the halo formation time and the concentration; these dependences are collectively termed 'assembly bias'. Applying modified Fisher matrix formalism, we explore whether these secondary variables have a significant impact on the study of dark energy properties using the self-calibration technique in current (SDSS) and the near future (DES, SPT, and LSST) cluster surveys. The impact of the secondary dependence is determined by (1) the scatter in the observable-mass relation and (2) the correlation between observable and secondary variables. We find that for optical surveys, the secondary dependence does not significantly influence an SDSS-like survey; however, it may affect a DES-like survey (given the high scatter currently expected from optical clusters) and an LSST-like survey (even for low scatter values and low correlations). For an SZ survey such as SPT, the impact of secondary dependence is insignificant if the scatter is 20% or lower but can be enhanced by the potential high scatter values introduced by a highly-correlated background. Accurate modeling of the assembly bias is necessary for cluster self-calibration in the era of precision cosmology.

  10. SURVEY ON CLUSTERING ALGORITHM AND SIMILARITY MEASURE FOR CATEGORICAL DATA

    OpenAIRE

    S. Anitha Elavarasi; J. Akilandeswari

    2014-01-01

    Learning is the process of generating useful information from a huge volume of data. Learning can be either supervised learning (e.g. classification) or unsupervised learning (e.g. Clustering) Clustering is the process of grouping a set of physical objects into classes of similar object. Objects in real world consist of both numerical and categorical data. Categorical data are not analyzed as numerical data because of the absence of inherit ordering. This paper describes about ten different c...

  11. Proximity of the manganese cluster of photosystem II to the redox-active tyrosine YZ.

    OpenAIRE

    Gilchrist, M L; Ball, J. A.; Randall, D W; Britt, R. D.

    1995-01-01

    Electron spin echo electron-nuclear double resonance (ESE-ENDOR) experiments performed on a broad radical electron paramagnetic resonance (EPR) signal observed in photosystem II particles depleted of Ca2+ indicate that this signal arises from the redox-active tyrosine YZ. The tyrosine EPR signal width is increased relative to that observed in a manganese-depleted preparation due to a magnetic interaction between the photosystem II manganese cluster and the tyrosine radical. The manganese clus...

  12. Clusters of galaxies in the HST Medium Deep Survey database

    Science.gov (United States)

    Ratnatunga, K. U.; Ostrander, E. J.; Griffiths, R. E.; Nichol, R. C.

    1997-12-01

    Quantitative morphological and structural parameters estimated for galaxies detected in the HST WFPC2 observations are now available on a set of CDROMS and is searchable via a web-interface at http://archive.stsci.edu/mds/ . A modeling approach based on maximum likelihood is used for the 2-dimensional Disk + Bulge decomposition of the faint undersampled galaxy images. We present a new objectively selected sample of galaxy overdensites found using the MDS database. These galaxy clusters represent some of the most distant systems ever detected and will facilitate more detailed studies of cluster and galaxy evolution.

  13. The Data Release of the Sloan Digital Sky Survey-II Supernova Survey

    DEFF Research Database (Denmark)

    Sako, Masao; Bassett, Bruce; C. Becker, Andrew

    2014-01-01

    This paper describes the data release of the Sloan Digital Sky Survey-II (SDSS-II) Supernova Survey conducted between 2005 and 2007. Light curves, spectra, classifications, and ancillary data are presented for 10,258 variable and transient sources discovered through repeat ugriz imaging of SDSS......, making this the largest sample of supernova candidates ever compiled. We present a new method for SN host-galaxy identification and derive host-galaxy properties including stellar masses, star-formation rates, and the average stellar population ages from our SDSS multi-band photometry. We derive SALT2...

  14. MOCCA-SURVEY Database I: Is NGC 6535 a Dark Star Cluster Harboring an IMBH?

    OpenAIRE

    Askar, Abbas; Bianchini, Paolo; de Vita, Ruggero; Giersz, Mirek; Hypki, Arkadiusz; Kamann, Sebastian

    2016-01-01

    We describe the dynamical evolution of a unique type of dark star cluster model in which the majority of the cluster mass at Hubble time is dominated by an intermediate-mass black hole (IMBH). We analyzed results from about 2000 star cluster models (Survey Database I) simulated using the Monte-Carlo code MOCCA and identified these dark star cluster models. Taking one of these models, we apply the method of simulating realistic "mock observations" by utilizing the COCOA and SISCO codes to obta...

  15. THE SWIFT X-RAY TELESCOPE CLUSTER SURVEY. III. CLUSTER CATALOG FROM 2005-2012 ARCHIVAL DATA

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Teng; Wang, Jun-Xian [CAS Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China, 230026 Hefei, Anhui (China); Tozzi, Paolo; Tundo, Elena [INAF, Osservatorio Astrofisico di Firenze, Largo Enrico Fermi 5, I-50125 Firenze (Italy); Moretti, Alberto [INAF, Osservatorio Astronomico di Brera, Via Brera 28, I-20121 Milano (Italy); Rosati, Piero [Università degli Studi di Ferrara, Dipartimento di Fisica e Scienze della Terra, Via Saragat 1, I-44121 Ferrara (Italy); Tagliaferri, Gianpiero; Campana, Sergio [INAF, Osservatorio Astronomico di Brera, Via Bianchi 46, I-23807 Merate (Italy); Giavalisco, Mauro, E-mail: liuteng@ustc.edu.cn [Department of Astronomy, University of Massachusetts, LGRT-B 619E, 710 North Pleasant Street, Amherst, MA (United States)

    2015-02-01

    We present the Swift X-ray Cluster Survey (SWXCS) catalog obtained using archival data from the X-ray telescope (XRT) on board the Swift satellite acquired from 2005 February to 2012 November, extending the first release of the SWXCS. The catalog provides positions, soft fluxes, and, when possible, optical counterparts for a flux-limited sample of X-ray group and cluster candidates. We consider the fields with Galactic latitude |b| > 20° to avoid high H I column densities. We discard all of the observations targeted at groups or clusters of galaxies, as well as particular extragalactic fields not suitable to search for faint extended sources. We finally select ∼3000 useful fields covering a total solid angle of ∼400 deg{sup 2}. We identify extended source candidates in the soft-band (0.5-2 keV) images of these fields using the software EXSdetect, which is specifically calibrated for the XRT data. Extensive simulations are used to evaluate contamination and completeness as a function of the source signal, allowing us to minimize the number of spurious detections and to robustly assess the selection function. Our catalog includes 263 candidate galaxy clusters and groups down to a flux limit of 7 × 10{sup –15} erg cm{sup –2} s{sup –1} in the soft band, and the logN-logS is in very good agreement with previous deep X-ray surveys. The final list of sources is cross-correlated with published optical, X-ray, and Sunyaev-Zeldovich catalogs of clusters. We find that 137 sources have been previously identified as clusters in the literature in independent surveys, while 126 are new detections. Currently, we have collected redshift information for 158 sources (60% of the entire sample). Once the optical follow-up and the X-ray spectral analysis of the sources are complete, the SWXCS will provide a large and well-defined catalog of groups and clusters of galaxies to perform statistical studies of cluster properties and tests of cosmological models.

  16. Status of the Transneptunian Automated Occultation Survey (TAOS II)

    Science.gov (United States)

    Lehner, Matthew; Wang, Shiang-Yu; Reyes-Ruiz, Mauricio; Alcock, Charles; Castro Chacón, Joel; Chen, Wen-Ping; Chu, You-Hua; Cook, Kem H.; Figueroa, Liliana; Geary, John C.; Hernandez, Benjamin; Huang, Chung-Kai; Norton, Timothy; Szentgyorgyi, Andrew; Yen, Wei-Ling; Zhang, Zhi-Wei

    2017-10-01

    The Transneptunian Automated Occultation Survey (TAOS II) will aim to detect occultations of stars by small (~1 km diameter) objects in the Kuiper Belt and beyond. Such events are very rare (<0.001 events per star per year) and short in duration (~200 ms), so many stars must be monitored at a high readout cadence. TAOS II will operate three 1.3 meter telescopes at the Observatorio Astronómico Nacional at San Pedro Mártir in Baja California, México. With a 2.3 square degree field of view and a high speed camera comprising CMOS imagers, the survey will monitor 10,000 stars simultaneously with all three telescopes at a readout cadence of 20 Hz. Construction of the site began in the fall of 2013 and was completed this summer. Telescope installation began in August 2017. This poster will provide an update on the status of the survey development and the schedule leading to the beginning of survey operations.

  17. Organization of the human keratin type II gene cluster at 12q13

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, S.J.; LeBlanc-Straceski, J.; Krauter, K. [Albert Einstein College of Medicine, Bronx, NY (United States)] [and others

    1994-12-01

    Keratin proteins constitute intermediate filaments and are the major differentiation products of mammalian epithelial cells. The epithelial keratins are classified into two groups, type I and type II, and one member of each group is expressed in a given epithelial cell differentiation stage. Mutations in type I and type II keratin genes have now been implicated in three different human genetic disorders, epidermolysis bullosa simplex, epidermolytic hyperkeratosis, and epidermolytic palmoplantar keratoderma. Members of the type I keratins are mapped to human chromosome 17, and the type II keratin genes are mapped to chromosome 12. To understand the organization of the type II keratin genes on chromosome 12, we isolated several yeast artificial chromosomes carrying these keratin genes and examined them in detail. We show that eight already known type II keratin genes are located in a cluster at 12q13, and their relative organization reflects their evolutionary relationship. We also determined that a type I keratin gene, KRT8, is located next to its partner, KRT18, in this cluster. Careful examination of the cluster also revealed that there may be a number of additional keratin genes at this locus that have not been described previously. 41 refs., 3 figs., 1 tab.

  18. A one-dimensional chain structure based on unusual tetranuclear manganese(II) clusters.

    Science.gov (United States)

    Che, Guang Bo; Wang, Jian; Liu, Chun Bo; Li, Xiu Ying; Liu, Bo

    2008-11-01

    The title coordination polymer, poly[bis(mu(4)-biphenyl-2,2'-dicarboxylato)(dipyrido[3,2-a:2',3'-c]phenazine)manganese(II)], [Mn(2)(C(14)H(8)O(4))(2)(C(18)H(10)N(4))](n), was obtained through the reaction of MnCl(2).4H(2)O, biphenyl-2,2'-dicarboxylic acid (H(2)dpdc) and dipyrido[3,2-a:2',3'-c]phenazine (L) under hydrothermal conditions. The asymmetric unit contains two crystallographically unique Mn(II) ions, one unique L ligand and two unique dpdc ligands. One Mn ion is six-coordinated by four O atoms from three different dpdc ligands and two N atoms from one L ligand, adopting a distorted octahedral coordination geometry. The distortions from ideal octahedral geometry are largely due to the presence of chelating ligands and the resulting acute N-Mn-N and O-Mn-O angles. The second Mn ion is coordinated in a distorted trigonal bipyramidal fashion by five O atoms from four distinct dpdc ligands. Four Mn(II) ions are bridged by the carboxylate groups of the dpdc ligands to form an unusual tetranuclear Mn(II) cluster. Clusters are further connected by the aromatic backbone of the dicarboxylate ligands, forming a one-dimensional chain structure along the b axis. The title compound is the first example of a chain structure based on a tetranuclear Mn(II) cluster.

  19. Primordial non-Gaussianity and Dark Energy constraints from Cluster Surveys

    Energy Technology Data Exchange (ETDEWEB)

    Sefusatti, Emiliano; Vale, Chris; /Fermilab; Kadota, Kenji; /Fermilab /Minnesota U., Theor. Phys. Inst.; Frieman, Joshua; /Fermilab /KICP, Chicago /Chicago U., Astron.

    2006-09-01

    Galaxy cluster surveys will be a powerful probe of dark energy. At the same time, cluster abundances is sensitive to any non-Gaussianity of the primordial density field. It is therefore possible that non-Gaussian initial conditions might be misinterpreted as a sign of dark energy or at least degrade the expected constraints on dark energy parameters. To address this issue, we perform a likelihood analysis of an ideal cluster survey similar in size and depth to the upcoming South Pole Telescope/Dark Energy Survey (SPT-DES).We analyze a model in which the strength of the non-Gaussianity is parameterized by the constant f{sub NL}; this model has been used extensively to derive Cosmic Microwave Background (CMB) anisotropy constraints on non-Gaussianity, allowing us to make contact with those works. We find that the constraining power of the cluster survey on dark energy observables is not significantly diminished by non-Gaussianity provided that cluster redshift information is included in the analysis. We also find that even an ideal cluster survey is unlikely to improve significantly current and future CMB constraints on non-Gaussianity. However, when all systematics are under control, it could constitute a valuable cross check to CMB observations.

  20. Parameter Estimation in Stratified Cluster Sampling under Randomized Response Models for Sensitive Question Survey.

    Science.gov (United States)

    Pu, Xiangke; Gao, Ge; Fan, Yubo; Wang, Mian

    2016-01-01

    Randomized response is a research method to get accurate answers to sensitive questions in structured sample survey. Simple random sampling is widely used in surveys of sensitive questions but hard to apply on large targeted populations. On the other side, more sophisticated sampling regimes and corresponding formulas are seldom employed to sensitive question surveys. In this work, we developed a series of formulas for parameter estimation in cluster sampling and stratified cluster sampling under two kinds of randomized response models by using classic sampling theories and total probability formulas. The performances of the sampling methods and formulas in the survey of premarital sex and cheating on exams at Soochow University were also provided. The reliability of the survey methods and formulas for sensitive question survey was found to be high.

  1. Parameter Estimation in Stratified Cluster Sampling under Randomized Response Models for Sensitive Question Survey.

    Directory of Open Access Journals (Sweden)

    Xiangke Pu

    Full Text Available Randomized response is a research method to get accurate answers to sensitive questions in structured sample survey. Simple random sampling is widely used in surveys of sensitive questions but hard to apply on large targeted populations. On the other side, more sophisticated sampling regimes and corresponding formulas are seldom employed to sensitive question surveys. In this work, we developed a series of formulas for parameter estimation in cluster sampling and stratified cluster sampling under two kinds of randomized response models by using classic sampling theories and total probability formulas. The performances of the sampling methods and formulas in the survey of premarital sex and cheating on exams at Soochow University were also provided. The reliability of the survey methods and formulas for sensitive question survey was found to be high.

  2. The Structure of the Young Star Cluster NGC 6231. II. Structure, Formation, and Fate

    Science.gov (United States)

    Kuhn, Michael A.; Getman, Konstantin V.; Feigelson, Eric D.; Sills, Alison; Gromadzki, Mariusz; Medina, Nicolás; Borissova, Jordanka; Kurtev, Radostin

    2017-12-01

    The young cluster NGC 6231 (stellar ages ˜2-7 Myr) is observed shortly after star formation activity has ceased. Using the catalog of 2148 probable cluster members obtained from Chandra, VVV, and optical surveys (Paper I), we examine the cluster’s spatial structure and dynamical state. The spatial distribution of stars is remarkably well fit by an isothermal sphere with moderate elongation, while other commonly used models like Plummer spheres, multivariate normal distributions, or power-law models are poor fits. The cluster has a core radius of 1.2 ± 0.1 pc and a central density of ˜200 stars pc-3. The distribution of stars is mildly mass segregated. However, there is no radial stratification of the stars by age. Although most of the stars belong to a single cluster, a small subcluster of stars is found superimposed on the main cluster, and there are clumpy non-isotropic distributions of stars outside ˜4 core radii. When the size, mass, and age of NGC 6231 are compared to other young star clusters and subclusters in nearby active star-forming regions, it lies at the high-mass end of the distribution but along the same trend line. This could result from similar formation processes, possibly hierarchical cluster assembly. We argue that NGC 6231 has expanded from its initial size but that it remains gravitationally bound.

  3. New variable stars discovered in the fields of three Galactic open clusters using the VVV survey

    Science.gov (United States)

    Palma, T.; Minniti, D.; Dékány, I.; Clariá, J. J.; Alonso-García, J.; Gramajo, L. V.; Ramírez Alegría, S.; Bonatto, C.

    2016-11-01

    This project is a massive near-infrared (NIR) search for variable stars in highly reddened and obscured open cluster (OC) fields projected on regions of the Galactic bulge and disk. The search is performed using photometric NIR data in the J-, H- and Ks- bands obtained from the Vista Variables in the Vía Láctea (VVV) Survey. We performed in each cluster field a variability search using Stetson's variability statistics to select the variable candidates. Later, those candidates were subjected to a frequency analysis using the Generalized Lomb-Scargle and the Phase Dispersion Minimization algorithms. The number of independent observations range between 63 and 73. The newly discovered variables in this study, 157 in total in three different known OCs, are classified based on their light curve shapes, periods, amplitudes and their location in the corresponding color-magnitude (J -Ks ,Ks) and color-color (H -Ks , J - H) diagrams. We found 5 possible Cepheid stars which, based on the period-luminosity relation, are very likely type II Cepheids located behind the bulge. Among the newly discovered variables, there are eclipsing binaries, δ Scuti, as well as background RR Lyrae stars. Using the new version of the Wilson & Devinney code as well as the "Physics Of Eclipsing Binaries" (PHOEBE) code, we analyzed some of the best eclipsing binaries we discovered. Our results show that these studied systems turn out to be ranging from detached to double-contact binaries, with low eccentricities and high inclinations of approximately 80°. Their surface temperatures range between 3500 K and 8000 K.

  4. New VVV Survey Globular Cluster Candidates in the Milky Way Bulge

    Energy Technology Data Exchange (ETDEWEB)

    Minniti, Dante; Gómez, Matías [Departamento de Física, Facultad de Ciencias Exactas, Universidad Andrés Bello, Av. Fernandez Concha 700, Las Condes, Santiago (Chile); Geisler, Douglas; Fernández-Trincado, Jose G. [Departamento de Astronomía, Casilla 160-C, Universidad de Concepción, Casilla 160-C, Concepción (Chile); Alonso-García, Javier; Beamín, Juan Carlos; Borissova, Jura; Catelan, Marcio; Ramos, Rodrigo Contreras; Kurtev, Radostin; Pullen, Joyce [Instituto Milenio de Astrofísica, Santiago (Chile); Palma, Tali; Clariá, Juan J. [Observatorio Astronómico, Universidad Nacional de Córdoba, Laprida 854, Córdoba (Argentina); Cohen, Roger E. [Space Telescope Science Institute, 2700 San Martin Drive, Baltimore (United States); Dias, Bruno [European Southern Observatory, Alonso de Cordova 3107, Vitacura, Santiago (Chile); Hempel, Maren [Pontificia Universidad Católica de Chile, Instituto de Astrofísica, Av. Vicuña Mackenna 4860, Santiago (Chile); Ivanov, Valentin D. [European Southern Observatory, Karl-Schwarszchild-Str. 2, D-85748 Garching bei Muenchen (Germany); Lucas, Phillip W. [Dept. of Astronomy, University of Hertfordshire, Hertfordshire (United Kingdom); Moni-Bidin, Christian; Alegría, Sebastian Ramírez [Instituto de Astronomía, Universidad Católica del Norte, Antofagasta (Chile); and others

    2017-11-10

    It is likely that a number of Galactic globular clusters remain to be discovered, especially toward the Galactic bulge. High stellar density combined with high and differential interstellar reddening are the two major problems for finding globular clusters located toward the bulge. We use the deep near-IR photometry of the VISTA Variables in the Vía Láctea (VVV) Survey to search for globular clusters projected toward the Galactic bulge, and hereby report the discovery of 22 new candidate globular clusters. These objects, detected as high density regions in our maps of bulge red giants, are confirmed as globular cluster candidates by their color–magnitude diagrams. We provide their coordinates as well as their near-IR color–magnitude diagrams, from which some basic parameters are derived, such as reddenings and heliocentric distances. The color–magnitude diagrams reveal well defined red giant branches in all cases, often including a prominent red clump. The new globular cluster candidates exhibit a variety of extinctions (0.06 < A {sub Ks} < 2.77) and distances (5.3 < D < 9.5 kpc). We also classify the globular cluster candidates into 10 metal-poor and 12 metal-rich clusters, based on the comparison of their color–magnitude diagrams with those of known globular clusters also observed by the VVV Survey. Finally, we argue that the census for Galactic globular clusters still remains incomplete, and that many more candidate globular clusters (particularly the low luminosity ones) await to be found and studied in detail in the central regions of the Milky Way.

  5. X-ray and optical substructures of the DAFT/FADA survey clusters

    Science.gov (United States)

    Guennou, L.; Durret, F.; Adami, C.; Lima Neto, G. B.

    2013-04-01

    We have undertaken the DAFT/FADA survey with the double aim of setting constraints on dark energy based on weak lensing tomography and of obtaining homogeneous and high quality data for a sample of 91 massive clusters in the redshift range 0.4-0.9 for which there were HST archive data. We have analysed the XMM-Newton data available for 42 of these clusters to derive their X-ray temperatures and luminosities and search for substructures. Out of these, a spatial analysis was possible for 30 clusters, but only 23 had deep enough X-ray data for a really robust analysis. This study was coupled with a dynamical analysis for the 26 clusters having at least 30 spectroscopic galaxy redshifts in the cluster range. Altogether, the X-ray sample of 23 clusters and the optical sample of 26 clusters have 14 clusters in common. We present preliminary results on the coupled X-ray and dynamical analyses of these 14 clusters.

  6. Too Little, Too Late: How the Tidal Evolution of Hot Jupiters Affects Transit Surveys of Clusters

    Science.gov (United States)

    Debes, John H.; Jackson, Brian

    2010-01-01

    The tidal evolution of hot Jupiters may change the efficiency of transit surveys of stellar clusters. The orbital decay that hot Jupiters suffer may result in their destruction, leaving fewer transiting planets in older clusters. We calculate the impact tidal evolution has for different assumed stellar populations, including that of 47 Tuc, a globular cluster that was the focus of an intense HST search for transits. We find that in older clusters one expects to detect fewer transiting planets by a factor of two for surveys sensitive to Jupiter-like planets in orbits out to 0.5 AU, and up to a factor of 25 for surveys sensitive to Jupiter-like planets in orbits out to 0.08 AU. Additionally, tidal evolution affects the distribution of transiting planets as a function of semi-major axis, producing larger orbital period gaps for transiting planets as the age of the cluster increases. Tidal evolution can explain the lack of detected exoplanets in 47 Tuc without invoking other mechanisms. Four open clusters residing within the Kepler fields of view have ages that span 0.4-8 Gyr-if Kepler can observe a significant number of planets in these clusters, it will provide key tests for our tidal evolution hypothesis. Finally, our results suggest that observers wishing to discover transiting planets in clusters must have sufficient accuracy to detect lower mass planets, search larger numbers of cluster members, or have longer observation windows to be confident that a significant number of transits will occur for a population of stars.

  7. The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. VIII. Preliminary Public Catalog Release

    Science.gov (United States)

    Soto, M.; Bellini, A.; Anderson, J.; Piotto, G.; Bedin, L. R.; van der Marel, R. P.; Milone, A. P.; Brown, T. M.; Cool, A. M.; King, I. R.; Sarajedini, A.; Granata, V.; Cassisi, S.; Aparicio, A.; Hidalgo, S.; Ortolani, S.; Nardiello, D.

    2017-01-01

    The Hubble Space Telescope (HST) UV Legacy Survey of Galactic Globular Clusters (GO-13297) has been specifically designed to complement the existing F606W and F814W observations of the Advanced Camera for Surveys (ACS) Globular Cluster Survey (GO-10775) by observing the most accessible 47 of the previous survey’s 65 clusters in three WFC3/UVIS filters F275W, F336W, and F438W. The new survey also adds super-solar metallicity open cluster NGC 6791 to increase the metallicity diversity. The combined survey provides a homogeneous 5-band data set that can be used to pursue a broad range of scientific investigations. In particular, the chosen UV filters allow the identification of multiple stellar populations by targeting the regions of the spectrum that are sensitive to abundance variations in C, N, and O. In order to provide the community with uniform preliminary catalogs, we have devised an automated procedure that performs high-quality photometry on the new UV observations (along with similar observations of seven other programs in the archive). This procedure finds and measures the potential sources on each individual exposure using library point-spread functions and cross-correlates these observations with the original ACS-Survey catalog. The catalog of 57 clusters we publish here will be useful to identify stars in the different stellar populations, in particular for spectroscopic follow-up. Eventually, we will construct a more sophisticated catalog and artificial-star tests based on an optimal reduction of the UV survey data, but the catalogs presented here give the community the chance to make early use of this HST Treasury survey.

  8. The JCMT Gould Belt Survey: Dense Core Clusters in Orion A

    Science.gov (United States)

    Lane, J.; Kirk, H.; Johnstone, D.; Mairs, S.; Di Francesco, J.; Sadavoy, S.; Hatchell, J.; Berry, D. S.; Jenness, T.; Hogerheijde, M. R.; Ward-Thompson, D.; The JCMT Gould Belt Survey Team

    2016-12-01

    The Orion A molecular cloud is one of the most well-studied nearby star-forming regions, and includes regions of both highly clustered and more dispersed star formation across its full extent. Here, we analyze dense, star-forming cores identified in the 850 and 450 μm SCUBA-2 maps from the JCMT Gould Belt Legacy Survey. We identify dense cores in a uniform manner across the Orion A cloud and analyze their clustering properties. Using two independent lines of analysis, we find evidence that clusters of dense cores tend to be mass segregated, suggesting that stellar clusters may have some amount of primordial mass segregation already imprinted in them at an early stage. We also demonstrate that the dense core clusters have a tendency to be elongated, perhaps indicating a formation mechanism linked to the filamentary structure within molecular clouds.

  9. The JCMT Gould Belt Survey: Dense Core Clusters in Orion B

    Science.gov (United States)

    Kirk, H.; Johnstone, D.; Di Francesco, J.; Lane, J.; Buckle, J.; Berry, D. S.; Broekhoven-Fiene, H.; Currie, M. J.; Fich, M.; Hatchell, J.; Jenness, T.; Mottram, J. C.; Nutter, D.; Pattle, K.; Pineda, J. E.; Quinn, C.; Salji, C.; Tisi, S.; Hogerheijde, M. R.; Ward-Thompson, D.; The JCMT Gould Belt Survey Team

    2016-04-01

    The James Clerk Maxwell Telescope Gould Belt Legacy Survey obtained SCUBA-2 observations of dense cores within three sub-regions of Orion B: LDN 1622, NGC 2023/2024, and NGC 2068/2071, all of which contain clusters of cores. We present an analysis of the clustering properties of these cores, including the two-point correlation function and Cartwright’s Q parameter. We identify individual clusters of dense cores across all three regions using a minimal spanning tree technique, and find that in each cluster, the most massive cores tend to be centrally located. We also apply the independent M-Σ technique and find a strong correlation between core mass and the local surface density of cores. These two lines of evidence jointly suggest that some amount of mass segregation in clusters has happened already at the dense core stage.

  10. A New Method for the Detection of Galaxy Clusters in X-Ray Surveys

    Energy Technology Data Exchange (ETDEWEB)

    Piacentine, J.M.; Marshall, P.J.; Peterson, J.R.; Andersson, K.E.

    2005-01-01

    For many years the power of counting clusters of galaxies as a function of their mass has been recognized as a powerful cosmological probe; however, we are only now beginning to acquire data from dedicated surveys with sufcient sky coverage and sensitivity to measure the cluster population out to distances where the dark energy came to dominate the Universe’s evolution. One such survey uses the XMM X-ray telescope to scan a large area of sky, detecting the X-ray photons from the hot plasma that lies in the deep potential wells of massive clusters of galaxies. These clusters appear as extended (not point-like) objects, each providing just a few hundred photons in a typical observation. The detection of extended sources in such a low signal-to-noise situation is an important problem in astrophysics: we attempt to solve it by using as much prior information as possible, translating our experience with wellmeasured clusters to define a “template” cluster that can be varied and matched to the features seen in the XMM images. In this work we adapt an existing Monte Carlo analysis code for this problem. Two detection templates were dened and their suitability explored using simulated data; the method was then applied to a publically avalable XMM observation of a “blank” field. Presented are the encouraging results of this series of experiments, suggesting that this approach continue to be developed for future cluster-identication endeavours.

  11. The VMC survey. XI. Radial stellar population gradients in the galactic globular cluster 47 Tucanae

    Energy Technology Data Exchange (ETDEWEB)

    Li, Chengyuan; De Grijs, Richard [Kavli Institute for Astronomy and Astrophysics, Peking University, Yi He Yuan Lu 5, Hai Dian District, Beijing 100871 (China); Deng, Licai [Key Laboratory for Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012 (China); Rubele, Stefano; Girardi, Leo; Gullieuszik, Marco [INAF-Osservatorio Astronomico di Padova, vicolo dell' Osservatorio 5, I-35122 Padova (Italy); Wang, Chuchu [Department of Astronomy, Peking University, Yi He Yuan Lu 5, Hai Dian District, Beijing 100871 (China); Bekki, Kenji; For, Bi-Qing [ICRAR M468, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 (Australia); Cioni, Maria-Rosa L. [Department of Physics, Astronomy, and Mathematics, University of Hertfordshire, Hatfield AL10 9AB (United Kingdom); Clementini, Gisella [INAF-Osservatorio Astronomico di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); Emerson, Jim [Astronomy Unit, School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Groenewegen, Martin A. T. [Royal Observatory of Belgium, Ringlaan 3, 1180 Ukkel (Belgium); Guandalini, Roald [Instituut voor Sterrenkunde, KU Leuven, Celestijnenlaan 200D 2401, 3001 Leuven (Belgium); Marconi, Marcella; Ripepi, Vincenzo [INAF-Osservatorio Astronomico di Capodimonte, via Moiariello 16, I-80131 Naples (Italy); Piatti, Andrés E. [Observatorio Astrońomico, Universidad Nacional de Córdoba, Laprida 854, 5000 Córdoba (Argentina); Van Loon, Jacco Th., E-mail: joshuali@pku.edu.cn, E-mail: grijs@pku.edu.cn [Astrophysics Group, Lennard-Jones Laboratories, Keele University, Staffordshire ST5 5BG (United Kingdom)

    2014-07-20

    We present a deep near-infrared color-magnitude diagram of the Galactic globular cluster 47 Tucanae, obtained with the Visible and Infrared Survey Telescope for Astronomy (VISTA) as part of the VISTA near-infrared Y, J, K{sub s} survey of the Magellanic System (VMC). The cluster stars comprising both the subgiant and red giant branches exhibit apparent, continuous variations in color-magnitude space as a function of radius. Subgiant branch stars at larger radii are systematically brighter than their counterparts closer to the cluster core; similarly, red-giant-branch stars in the cluster's periphery are bluer than their more centrally located cousins. The observations can very well be described by adopting an age spread of ∼0.5 Gyr as well as radial gradients in both the cluster's helium abundance (Y) and metallicity (Z), which change gradually from (Y = 0.28, Z = 0.005) in the cluster core to (Y = 0.25, Z = 0.003) in its periphery. We conclude that the cluster's inner regions host a significant fraction of second-generation stars, which decreases with increasing radius; the stellar population in the 47 Tuc periphery is well approximated by a simple stellar population.

  12. The Gaia-ESO Survey: the inner disk, intermediate-age open cluster Trumpler 23

    Science.gov (United States)

    Overbeek, J. C.; Friel, E. D.; Donati, P.; Smiljanic, R.; Jacobson, H. R.; Hatzidimitriou, D.; Held, E. V.; Magrini, L.; Bragaglia, A.; Randich, S.; Vallenari, A.; Cantat-Gaudin, T.; Tautvaišienė, G.; Jiménez-Esteban, F.; Frasca, A.; Geisler, D.; Villanova, S.; Tang, B.; Muñoz, C.; Marconi, G.; Carraro, G.; San Roman, I.; Drazdauskas, A.; Ženovienė, R.; Gilmore, G.; Jeffries, R. D.; Flaccomio, E.; Pancino, E.; Bayo, A.; Costado, M. T.; Damiani, F.; Jofré, P.; Monaco, L.; Prisinzano, L.; Sousa, S. G.; Zaggia, S.

    2017-02-01

    Context. Trumpler 23 is a moderately populated, intermediate-age open cluster within the solar circle at a RGC 6 kpc. It is in a crowded field very close to the Galactic plane and the color-magnitude diagram shows significant field contamination and possible differential reddening; it is a relatively understudied cluster for these reasons, but its location makes it a key object for determining Galactic abundance distributions. Aims: New data from the Gaia-ESO Survey enable the first ever radial velocity and spectroscopic metallicity measurements for this cluster. We aim to use velocities to isolate cluster members, providing more leverage for determining cluster parameters. Methods: Gaia-ESO Survey data for 167 potential members have yielded radial velocity measurements, which were used to determine the systemic velocity of the cluster and membership of individual stars. Atmospheric parameters were also used as a check on membership when available. Literature photometry was used to re-determine cluster parameters based on radial velocity member stars only; theoretical isochrones are fit in the V, V-I diagram. Cluster abundance measurements of ten radial-velocity member stars with high-resolution spectroscopy are presented for 24 elements. These abundances have been compared to local disk stars, and where possible placed within the context of literature gradient studies. Results: We find Trumpler 23 to have an age of 0.80 ± 0.10 Gyr, significant differential reddening with an estimated mean cluster E(V-I) of 1.02, and an apparent distance modulus of 14.15 ± 0.20. We find an average cluster metallicity of [Fe/H] = 0.14 ± 0.03 dex, a solar [α/Fe] abundance, and notably subsolar [s-process/Fe] abundances.

  13. The High-Z Clusters Occupied by Bent Radio AGN (COBRA) Survey

    Science.gov (United States)

    Golden-Marx, Emmet; Blanton, Elizabeth; Paterno-Mahler, Rachel; Brodwin, Mark; Ashby, Matthew; Wing, Joshua; Anand, Gagandeep; Decker, Bandon

    2017-07-01

    To probe the earliest eras of cluster formation, we need to find clusters with a variety of morphological states and masses across redshift space. Here, we present results from the Clusters Occupied by Bent Radio AGN (COBRA) Survey. The COBRA survey includes 646 bent, double-lobed radio sources selected from the VLA FIRST Survey, infrared observations from Spitzer, and optical observations from the Discovery Channel Telescope. The COBRA survey spans the redshift range 0.5 < z < 3.0 and includes objects with a wide range of masses and dynamical states. The bent radio morphology results from interactions between the AGN host galaxy and the surrounding intracluster medium; the relative motion results in ram pressure acting on the lobes, bending them. Using our IR and optical data, we measure galaxy excesses, locate red sequence galaxies, and determine photometric redshifts. We find that at least 30% of our high-z the bent radio sources are found in clusters or protoclusters. Additionally, we measure galaxy surface densities to trace out the large-scale cluster morphologies.

  14. Real-time dynamics of RNA Polymerase II clustering in live human cells

    Science.gov (United States)

    Cisse, Ibrahim

    2014-03-01

    Transcription is the first step in the central dogma of molecular biology, when genetic information encoded on DNA is made into messenger RNA. How this fundamental process occurs within living cells (in vivo) is poorly understood,[1] despite extensive biochemical characterizations with isolated biomolecules (in vitro). For high-order organisms, like humans, transcription is reported to be spatially compartmentalized in nuclear foci consisting of clusters of RNA Polymerase II, the enzyme responsible for synthesizing all messenger RNAs. However, little is known of when these foci assemble or their relative stability. We developed an approach based on photo-activation localization microscopy (PALM) combined with a temporal correlation analysis, which we refer to as tcPALM. The tcPALM method enables the real-time characterization of biomolecular spatiotemporal organization, with single-molecule sensitivity, directly in living cells.[2] Using tcPALM, we observed that RNA Polymerase II clusters form transiently, with an average lifetime of 5.1 (+/- 0.4) seconds. Stimuli affecting transcription regulation yielded orders of magnitude changes in the dynamics of the polymerase clusters, implying that clustering is regulated and plays a role in the cells ability to effect rapid response to external signals. Our results suggest that the transient crowding of enzymes may aid in rate-limiting steps of genome regulation.

  15. Evidence that azide occupies the chloride binding site near the manganese cluster in photosystem II.

    Science.gov (United States)

    Yu, Hui; Aznar, Constantino P; Xu, Xianzhong; Britt, R David

    2005-09-13

    The effect of adding azide to photosystem II (PS II) membrane samples (BBY preparation), with or without chloride, has been investigated using continuous wave (CW) and pulsed EPR spectroscopy. In the BBY samples with 25 mM chloride, we observed that the inhibition induced by azide is partly recovered by the addition of bicarbonate. Electron spin-echo envelope modulation (ESEEM) was used to search for spin transitions of 15N nuclei magnetically coupled to the S2 state Mn cluster (multiline EPR signal form) in 15N (single terminal label) azide-treated samples with negative results. However, an 15N ESEEM peak was observed in parallel chloride-depleted PS II samples when the 15N-labeled azide is added. However, this peak is absent in chloride-depleted samples incubated in buffer containing both chloride and [15N]azide. Thus these results demonstrate an azide binding site in the immediate vicinity of the Mn cluster, and since this site appears to be competitive with chloride, these results provide further evidence that chloride is bound proximal to the Mn cluster as well. Discussion on the possible interplay between azide, chloride, and bicarbonate is provided.

  16. Substructures in DAFT/FADA survey clusters based on XMM and optical data

    Science.gov (United States)

    Durret, F.; DAFT/FADA Team

    2014-07-01

    The DAFT/FADA survey was initiated to perform weak lensing tomography on a sample of 90 massive clusters in the redshift range [0.4,0.9] with HST imaging available. The complementary deep multiband imaging constitutes a high quality imaging data base for these clusters. In X-rays, we have analysed the XMM-Newton and/or Chandra data available for 32 clusters, and for 23 clusters we fit the X-ray emissivity with a beta-model and subtract it to search for substructures in the X-ray gas. This study was coupled with a dynamical analysis for the 18 clusters with at least 15 spectroscopic galaxy redshifts in the cluster range, based on a Serna & Gerbal (SG) analysis. We detected ten substructures in eight clusters by both methods (X-rays and SG). The percentage of mass included in substructures is found to be roughly constant with redshift, with values of 5-15%. Most of the substructures detected both in X-rays and with the SG method are found to be relatively recent infalls, probably at their first cluster pericenter approach.

  17. The Hubble Space Telescope Medium Deep Survey Cluster Sample: Methodology and Data

    Science.gov (United States)

    Ostrander, E. J.; Nichol, R. C.; Ratnatunga, K. U.; Griffiths, R. E.

    1998-12-01

    We present a new, objectively selected, sample of galaxy overdensities detected in the Hubble Space Telescope Medium Deep Survey (MDS). These clusters/groups were found using an automated procedure that involved searching for statistically significant galaxy overdensities. The contrast of the clusters against the field galaxy population is increased when morphological data are used to search around bulge-dominated galaxies. In total, we present 92 overdensities above a probability threshold of 99.5%. We show, via extensive Monte Carlo simulations, that at least 60% of these overdensities are likely to be real clusters and groups and not random line-of-sight superpositions of galaxies. For each overdensity in the MDS cluster sample, we provide a richness and the average of the bulge-to-total ratio of galaxies within each system. This MDS cluster sample potentially contains some of the most distant clusters/groups ever detected, with about 25% of the overdensities having estimated redshifts z > ~0.9. We have made this sample publicly available to facilitate spectroscopic confirmation of these clusters and help more detailed studies of cluster and galaxy evolution. We also report the serendipitous discovery of a new cluster close on the sky to the rich optical cluster Cl l0016+16 at z = 0.546. This new overdensity, HST 001831+16208, may be coincident with both an X-ray source and a radio source. HST 001831+16208 is the third cluster/group discovered near to Cl 0016+16 and appears to strengthen the claims of Connolly et al. of superclustering at high redshift.

  18. The Sloan Digital Sky Survey-II Supernova Survey: Technical Summary

    Energy Technology Data Exchange (ETDEWEB)

    Frieman, Joshua A.; /Fermilab /KICP, Chicago /Chicago U., Astron. Astrophys. Ctr.; Bassett, Bruce; /Cape Town U. /South African Astron. Observ.; Becker, Andrew; /Washington; Choi, Changsu; /Seoul Natl. U.; Cinabro, David; /Wayne State U.; DeJongh, Don Frederic; /Fermilab; Depoy, Darren L.; /Ohio State U.; Doi, Mamoru; /Tokyo U.; Garnavich, Peter M.; /Notre Dame U.; Hogan, Craig J.; /Washington U., Seattle, Astron. Dept.; Holtzman, Jon; /New Mexico State U.; Im, Myungshin; /Seoul Natl. U.; Jha, Saurabh; /Stanford U., Phys. Dept.; Konishi, Kohki; /Tokyo U.; Lampeitl, Hubert; /Baltimore, Space Telescope Sci.; Marriner, John; /Fermilab; Marshall, Jennifer L.; /Ohio State U.; McGinnis,; /Fermilab; Miknaitis, Gajus; /Fermilab; Nichol, Robert C.; /Portsmouth U.; Prieto, Jose Luis; /Ohio State U. /Rochester Inst. Tech. /Stanford U., Phys. Dept. /Pennsylvania U.

    2007-09-14

    The Sloan Digital Sky Survey-II (SDSS-II) has embarked on a multi-year project to identify and measure light curves for intermediate-redshift (0.05 < z < 0.35) Type Ia supernovae (SNe Ia) using repeated five-band (ugriz) imaging over an area of 300 sq. deg. The survey region is a stripe 2.5 degrees wide centered on the celestial equator in the Southern Galactic Cap that has been imaged numerous times in earlier years, enabling construction of a deep reference image for discovery of new objects. Supernova imaging observations are being acquired between 1 September and 30 November of 2005-7. During the first two seasons, each region was imaged on average every five nights. Spectroscopic follow-up observations to determine supernova type and redshift are carried out on a large number of telescopes. In its first two three-month seasons, the survey has discovered and measured light curves for 327 spectroscopically confirmed SNe Ia, 30 probable SNe Ia, 14 confirmed SNe Ib/c, 32 confirmed SNe II, plus a large number of photometrically identified SNe Ia, 94 of which have host-galaxy spectra taken so far. This paper provides an overview of the project and briefly describes the observations completed during the first two seasons of operation.

  19. The XMM-BCS galaxy cluster survey: I. The X-ray selected cluster catalog from the initial 6 deg$^2$

    Energy Technology Data Exchange (ETDEWEB)

    Suhada, R.; /Munich, Tech. U. /Munich U.; Song, J.; /Michigan U.; Bohringer, H.; /Munich, Tech. U.; Mohr, J.J.; /Munich, Tech. U. /Munich U. /Munich, Tech. U., Universe; Chon, G.; /Munich, Tech. U.; Finoguenov, A.; /Munich, Tech. U. /CSST, Baltimore; Fassbender, R.; /Munich, Tech. U. /CSST, Baltimore; Desai, S.; /Munich U. /Illinois U., Urbana; Armstrong, R.; /Illinois U., Urbana; Zenteno, A.; /Munich U. /Munich, Tech. U., Universe; Barkhouse, W.A.; /North Dakota U. /Paris, Inst. Astrophys.

    2011-11-01

    The XMM-Newton - Blanco Cosmology Survey project (XMM-BCS) is a coordinated X-ray, optical and mid-infrared cluster survey in a field also covered by Sunyaev-Zel dovich effect (SZE) surveys by the South Pole Telescope and the Atacama Cosmology Telescope. The aim of the project is to study the cluster population in a 14 deg{sup 2} field (center: {alpha} {approx} 23:29:18.4, {delta} {approx} -54:40:33.6). The uniform multi-wavelength coverage will also allow us for the first time to comprehensively compare the selection function of the different cluster detection approaches in a single test field and perform a cross-calibration of cluster scaling relations. In this work, we present a catalog of 46 X-ray selected clusters from the initial 6 deg{sup 2} survey core.We describe the XMM-BCS source detection pipeline and derive physical properties of the clusters. We provide photometric redshift estimates derived from the BCS imaging data and spectroscopic redshift measurements for a low redshift subset of the clusters. The photometric redshift estimates are found to be unbiased and in good agreement with the spectroscopic values. Our multi-wavelength approach gives us a comprehensive look at the cluster and group population up to redshifts z {approx} 1. The median redshift of the sample is 0.47 and the median mass M{sub 500} {approx} 1 x 10{sup 14} M{sub {circle_dot}} ({approx} 2 keV). From the sample, we derive the cluster log N - log S using an approximation to the survey selection function and find it in good agreement with previous studies. We compare optical mass estimates from the Southern Cosmology Survey available for part of our cluster sample with our estimates derived from the X-ray luminosity. Weak lensing masses available for a subset of the cluster sample are in agreement with our estimates. Optical masses based on cluster richness and total optical luminosity are found to be significantly higher than the X-ray values. The present results illustrate the

  20. COMPARING DENSE GALAXY CLUSTER REDSHIFT SURVEYS WITH WEAK-LENSING MAPS

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Ho Seong; Geller, Margaret J.; Zahid, H. Jabran [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Diaferio, Antonaldo [Dipartimento di Fisica, Università degli Studi di Torino, V. Pietro Giuria 1, I-10125 Torino (Italy); Rines, Kenneth J., E-mail: hhwang@cfa.harvard.edu, E-mail: mgeller@cfa.harvard.edu, E-mail: harus.zahid@cfa.harvard.edu, E-mail: diaferio@ph.unito.it, E-mail: kenneth.rines@wwu.edu [Department of Physics and Astronomy, Western Washington University, Bellingham, WA 98225 (United States)

    2014-12-20

    We use dense redshift surveys of nine galaxy clusters at z ∼ 0.2 to compare the galaxy distribution in each system with the projected matter distribution from weak lensing. By combining 2087 new MMT/Hectospec redshifts and the data in the literature, we construct spectroscopic samples within the region of weak-lensing maps of high (70%-89%) and uniform completeness. With these dense redshift surveys, we construct galaxy number density maps using several galaxy subsamples. The shape of the main cluster concentration in the weak-lensing maps is similar to the global morphology of the number density maps based on cluster members alone, mainly dominated by red members. We cross-correlate the galaxy number density maps with the weak-lensing maps. The cross-correlation signal when we include foreground and background galaxies at 0.5z {sub cl} < z < 2z {sub cl} is 10%-23% larger than for cluster members alone at the cluster virial radius. The excess can be as high as 30% depending on the cluster. Cross-correlating the galaxy number density and weak-lensing maps suggests that superimposed structures close to the cluster in redshift space contribute more significantly to the excess cross-correlation signal than unrelated large-scale structure along the line of sight. Interestingly, the weak-lensing mass profiles are not well constrained for the clusters with the largest cross-correlation signal excesses (>20% for A383, A689, and A750). The fractional excess in the cross-correlation signal including foreground and background structures could be a useful proxy for assessing the reliability of weak-lensing cluster mass estimates.

  1. [C II] 158-micrometer Observations of a Sample of Late-type Galaxies from the Virgo Cluster

    Science.gov (United States)

    Leech, K. J.; Volk, H. J.; Heinrichsen, I.; Hippelein, H.; Metcalfe, L.; Pierini, D.; Popescu, C. C.; Tuffs, R. J.; Xu, C.

    1998-01-01

    We have observed 19 Virgo cluster spiral galaxies with the Long Wavelength Spectrometer (LWS) onboard ESAs Infrared Space Observatory (ISO) obtaining spectral around the (C II) 157.741-micrometer fine structure line.

  2. The HST survey of Magellanic-Cloud clusters and of their stellar populations

    Science.gov (United States)

    Milone, A. P.

    2017-03-01

    A large number of intermediate-age (~1-2-Gyr old) globular clusters (GCs) in the Large and the Small Magellanic Cloud (MC) exhibit either bimodal or extended main-sequence (MS) turn off and dual red clump (RC). Moreover, recent papers have shown that the MS of the young clusters NGC 1844 and NGC 1856 is either broadened or split. These features of the color-magnitude diagram (CMD) are not consistent with a single isochrone and suggest that star clusters in MCs have experienced a prolonged star formation, in close analogy with Milky-Way GCs with multiple stellar populations. As an alternative, stellar rotation or interacting binaries can be responsible of the CMD morphology. In the following I will summarize the observational scenario and provide constraints on the nature of the complex CMD of young and intermediate-age MC clusters from our ongoing photometric survey with the Hubble Space Telescope (HST).

  3. XMM-Newton Observations of the DLS Shear-Selected Cluster Survey

    Science.gov (United States)

    DellAntonio, Ian

    2005-01-01

    The goal of this project continues to be to test the selection effects in cluster surveys by investigating the X-ray properties of the first shear-selected sample of galaxy clusters, the Deep Lens Survey (DLS). Because lensing signal is only sensitive to mass (albeit with projection effects), lensing signal can be used to select a sample that is independent of its X-ray properties. If a lensing-selected sample has very different X-ray properties from an X-ray selected sample, it would have important consequences for evolutionary studies based on existing cluster samples was aimed at refining the lensing-selected sample as part of this continuing study The grant supported a KPNO run to obtain data on another region of the sky to extend the cluster sample, and also the purchase of a disk array for archiving the optical mosaic data (Two terabytes worth) from which the lensing maps are derived As a result of the grant, we have extended the lensing cluster sample to another 4-square degree patch of the sky, adding another three clusters to our sample to be observed While the sample of X-ray observed clusters is too small to derive a firm conclusion yet, our preliminary finding is that the X-ray properties of the observed sample do not differ from those of X-ray selected surveys A paper discussing the first results has been published, and a second paper on the mass differences is still in preparation (with J Hughes as first author)

  4. Survey of biomass gasification. Volume II. Principles of gasification

    Energy Technology Data Exchange (ETDEWEB)

    Reed, T.B. (comp.)

    1979-07-01

    Biomass can be converted by gasification into a clean-burning gaseous fuel that can be used to retrofit existing gas/oil boilers, to power engines, to generate electricity, and as a base for synthesis of methanol, gasoline, ammonia, or methane. This survey describes biomass gasification, associated technologies, and issues in three volumes. Volume I contains the synopsis and executive summary, giving highlights of the findings of the other volumes. In Volume II the technical background necessary for understanding the science, engineering, and commercialization of biomass is presented. In Volume III the present status of gasification processes is described in detail, followed by chapters on economics, gas conditioning, fuel synthesis, the institutional role to be played by the federal government, and recommendations for future research and development.

  5. The ACS Virgo Cluster Survey XV. The Formation Efficiencies of Globular Clusters in Early-Type Galaxies: The Effects of Mass and Environment

    OpenAIRE

    Peng, Eric W.; Jordan, Andres; Cote, Patrick; Takamiya, Marianne; West, Michael J.; Blakeslee, John P.; Chen, Chin-Wei; Ferrarese, Laura; Mei, Simona; Tonry, John L.; West, Andrew A.

    2008-01-01

    The fraction of stellar mass contained in globular clusters (GCs), also measured by number as the specific frequency, is a fundamental quantity that reflects both a galaxy's early star formation and its entire merging history. We present specific frequencies, luminosities, and mass fractions for the globular cluster systems of 100 early-type galaxies in the ACS Virgo Cluster Survey, the largest homogeneous catalog of its kind. We find that 1) GC mass fractions can be high in both giants and d...

  6. Legacy ExtraGalactic UV Survey with The Hubble Space Telescope: Stellar Cluster Catalogs and First Insights Into Cluster Formation and Evolution in NGC 628

    NARCIS (Netherlands)

    Adamo, A.; Ryon, J.E.; Messa, M.; Kim, H.; Grasha, K.; Cook, D.O.; Calzetti, D.; Lee, J.C.; Whitmore, B.C.; Elmegreen, B.G.; Ubeda, L.; Smith, L.J.; Bright, S.N.; Runnholm, A.; Andrews, J.E.; Fumagalli, M.; Gouliermis, D.A.; Kahre, L.; Nair, P.; Thilker, D.; Walterbos, R.; Wofford, A.; Aloisi, A.; Ashworth, G.; Brown, T.M.; Chandar, R.; Christian, C.; Cignoni, M.; Clayton, G.C.; Dale, D.A.; de Mink, S.E.; Dobbs, C.; Elmegreen, D.M.; Evans, A.S.; Gallagher III, J.S.; Grebel, E.K.; Herrero, A.; Hunter, D.A.; Johnson, K.E.; Kennicutt, R.C.; Krumholz, M.R.; Lennon, D.; Levay, K.; Martin, C.; Nota, A.; Östlin, G.; Pellerin, A.; Prieto, J.; Regan, M.W.; Sabbi, E.; Sacchi, E.; Schaerer, D.; Schiminovich, D.; Shabani, F.; Tosi, M.; Van Dyk, S.D.; Zackrisson, E.

    2017-01-01

    We report the large effort that is producing comprehensive high-level young star cluster (YSC) catalogs for a significant fraction of galaxies observed with the Legacy ExtraGalactic UV Survey (LEGUS) Hubble treasury program. We present the methodology developed to extract cluster positions, verify

  7. THE HST/ACS COMA CLUSTER SURVEY. VIII. BARRED DISK GALAXIES IN THE CORE OF THE COMA CLUSTER

    Energy Technology Data Exchange (ETDEWEB)

    Marinova, Irina; Jogee, Shardha; Weinzirl, Tim [Department of Astronomy, University of Texas at Austin, Austin, TX (United States); Erwin, Peter [Max-Planck-Insitut fuer extraterrestrische Physik, Giessenbachstrasse, 85748 Garching (Germany); Trentham, Neil [Institute of Astronomy, Madingley Road, Cambridge, CB3 0HA (United Kingdom); Ferguson, Henry C.; Goudfrooij, Paul [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Hammer, Derek [Department of Physics and Astronomy, Johns Hopkins, Baltimore, MD 21218 (United States); Den Brok, Mark; Peletier, Reynier F.; Kleijn, Gijs V. [Kapteyn Astronomical Institute, University of Groningen, Groningen (Netherlands); Graham, Alister W. [Centre for Astrophysics and Supercomputing, Swinburne University, Hawthorn (Australia); Carter, David; Mouhcine, Mustapha [Astrophysics Research Institute, Liverpool John Moores University, Birkenhead (United Kingdom); Balcells, Marc [Instituto de Astrofisica de Canarias, 38200 La Laguna, Tenerife (Spain); Guzman, Rafael; Hoyos, Carlos [Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States); Mobasher, Bahram [Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States); Peng, Eric W., E-mail: marinova@astro.as.utexas.edu, E-mail: sj@astro.as.utexas.edu [Department of Astronomy, Peking University, Beijing 100871 (China)

    2012-02-20

    We use high-resolution ({approx}0.''1) F814W Advanced Camera for Surveys (ACS) images from the Hubble Space Telescope ACS Treasury survey of the Coma cluster at z {approx} 0.02 to study bars in massive disk galaxies (S0s), as well as low-mass dwarf galaxies in the core of the Coma cluster, the densest environment in the nearby universe. Our study helps to constrain the evolution of bars and disks in dense environments and provides a comparison point for studies in lower density environments and at higher redshifts. Our results are: (1) we characterize the fraction and properties of bars in a sample of 32 bright (M{sub V} {approx}< -18, M{sub *} > 10{sup 9.5} M{sub Sun }) S0 galaxies, which dominate the population of massive disk galaxies in the Coma core. We find that the measurement of a bar fraction among S0 galaxies must be handled with special care due to the difficulty in separating unbarred S0s from ellipticals, and the potential dilution of the bar signature by light from a relatively large, bright bulge. The results depend sensitively on the method used: the bar fraction for bright S0s in the Coma core is 50% {+-} 11%, 65% {+-} 11%, and 60% {+-} 11% based on three methods of bar detection, namely, strict ellipse fit criteria, relaxed ellipse fit criteria, and visual classification. (2) We compare the S0 bar fraction across different environments (the Coma core, A901/902, and Virgo) adopting the critical step of using matched samples and matched methods in order to ensure robust comparisons. We find that the bar fraction among bright S0 galaxies does not show a statistically significant variation (within the error bars of {+-}11%) across environments which span two orders of magnitude in galaxy number density (n {approx} 300-10,000 galaxies Mpc{sup -3}) and include rich and poor clusters, such as the core of Coma, the A901/902 cluster, and Virgo. We speculate that the bar fraction among S0s is not significantly enhanced in rich clusters compared to

  8. The Gaia-ESO survey: the inner disk intermediate-age open cluster NGC 6802

    Science.gov (United States)

    Tang, B.; Geisler, D.; Friel, E.; Villanova, S.; Smiljanic, R.; Casey, A. R.; Randich, S.; Magrini, L.; San Roman, I.; Muñoz, C.; Cohen, R. E.; Mauro, F.; Bragaglia, A.; Donati, P.; Tautvaišien*error*ė, G.; Drazdauskas, A.; Ženovienė, R.; Snaith, O.; Sousa, S.; Adibekyan, V.; Costado, M. T.; Blanco-Cuaresma, S.; Jiménez-Esteban, F.; Carraro, G.; Zwitter, T.; François, P.; Jofrè, P.; Sordo, R.; Gilmore, G.; Flaccomio, E.; Koposov, S.; Korn, A. J.; Lanzafame, A. C.; Pancino, E.; Bayo, A.; Damiani, F.; Franciosini, E.; Hourihane, A.; Lardo, C.; Lewis, J.; Monaco, L.; Morbidelli, L.; Prisinzano, L.; Sacco, G.; Worley, C. C.; Zaggia, S.

    2017-05-01

    Milky Way open clusters are very diverse in terms of age, chemical composition, and kinematic properties. Intermediate-age and old open clusters are less common, and it is even harder to find them inside the solar Galactocentric radius, due to the high mortality rate and strong extinction inside this region. NGC 6802 is one of the inner disk open clusters (IOCs) observed by the Gaia-ESO survey (GES). This cluster is an important target for calibrating the abundances derived in the survey due to the kinematic and chemical homogeneity of the members in open clusters. Using the measurements from Gaia-ESO internal data release 4 (iDR4), we identify 95 main-sequence dwarfs as cluster members from the GIRAFFE target list, and eight giants as cluster members from the UVES target list. The dwarf cluster members have a median radial velocity of 13.6 ± 1.9 km s-1, while the giant cluster members have a median radial velocity of 12.0 ± 0.9 km s-1 and a median [Fe/H] of 0.10 ± 0.02 dex. The color-magnitude diagram of these cluster members suggests an age of 0.9 ± 0.1 Gyr, with (m-M)0 = 11.4 and E(B-V) = 0.86. We perform the first detailed chemical abundance analysis of NGC 6802, including 27 elemental species. To gain a more general picture about IOCs, the measurements of NGC 6802 are compared with those of other IOCs previously studied by GES, that is, NGC 4815, Trumpler 20, NGC 6705, and Berkeley 81. NGC 6802 shows similar C, N, Na, and Al abundances as other IOCs. These elements are compared with nucleosynthetic models as a function of cluster turn-off mass. The α, iron-peak, and neutron-capture elements are also explored in a self-consistent way. Full Tables A.3-A.6 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/601/A56

  9. Initial results from the Arecibo Galaxy Environment Survey in the Pegasus Cluster

    Science.gov (United States)

    Minchin, Robert; Taylor, Rhys; AGES Collaboration

    2018-01-01

    As part of the Arecibo Galaxy Environment Survey (AGES), we have covered a 5deg x 4deg region centered on the Pegasus Cluster and its principal member, the elliptical galaxy NGC 7619, in the 21-cm line of neutral hydrogen. The survey takes in the full redshift range of the cluster and the volume behind it out to 18,000 km/s. In the cluster and the volume we detect over 500 sources, many of which are previously uncataloged. These include five sources without obvious optical counterparts (three within the redshift range of the cluster, which are assumed to be members); of these, four (two within the cluster) have possible low surface-brightness counterparts identified on stacked and/or smoothed SDSS images, while the third remains without an optical counterpart. We also detect three low surface-brightness ultra-diffuse galaxies from the catalog of Shi et al. (2017) in HI for the first time, and find fourteen other HI sources where both a UDG and other potential counterparts are present in the beam, making an unambiguous association with the UDG not possible on the basis of this data alone. In addition to these, we detect N objects with HI and stellar streams.

  10. The Open Cluster Chemical Abundances and Mapping (OCCAM) Survey: Galactic Neutron CaptureAbundance Gradients

    Science.gov (United States)

    O'Connell, Julia; Frinchaboy, Peter M.; Shetrone, Matthew D.; Melendez, Matthew; Cunha, Katia; Majewski, Steven R.; Zasowski, Gail; APOGEE Team

    2017-06-01

    The evolution of elements, as a function or age, throughout the Milky Way disk provides a key constraint for galaxy evolution models. In an effort to provide these constraints, we have conducted an investigation into the r- and s- process elemental abundances for a large sample of open clusters as part of an optical follow-up to the SDSS-III/APOGEE-1 survey. Stars were identified as cluster members by the Open Cluster Chemical Abundance & Mapping (OCCAM) survey, which culls member candidates by radial velocity, metallicity and proper motion from the observed APOGEE sample. To obtain data for neutron capture elements in these clusters, we conducted a long-term observing campaign covering three years (2013-2016) using the McDonald Observatory Otto Struve 2.1-m telescope and Sandiford Cass Echelle Spectrograph (R ~ 60,000). We present Galactic neutron capture abundance gradients using 30+ clusters, within 6 kpc of the Sun, covering a range of ages from ~80 Myr to ~10 Gyr .

  11. The scaling relation of early-type galaxies in clusters II. Spectroscopic data for galaxies in eight nearby clusters

    DEFF Research Database (Denmark)

    Bettoni, D.; Moles, M.; Fasano, G.

    2006-01-01

    Galaxies: elliptical and lenticulars, cD, distances and redshifts - clusters: general Udgivelsesdato: June......Galaxies: elliptical and lenticulars, cD, distances and redshifts - clusters: general Udgivelsesdato: June...

  12. The High-redshift Clusters Occupied by Bent Radio AGN (COBRA) Survey: The Spitzer Catalog

    Science.gov (United States)

    Paterno-Mahler, R.; Blanton, E. L.; Brodwin, M.; Ashby, M. L. N.; Golden-Marx, E.; Decker, B.; Wing, J. D.; Anand, G.

    2017-07-01

    We present 190 galaxy cluster candidates (most at high redshift) based on galaxy overdensity measurements in the Spitzer/IRAC imaging of the fields surrounding 646 bent, double-lobed radio sources drawn from the Clusters Occupied by Bent Radio AGN (COBRA) Survey. The COBRA sources were chosen as objects in the Very Large Array FIRST survey that lack optical counterparts in the Sloan Digital Sky Survey to a limit of m r = 22, making them likely to lie at high redshift. This is confirmed by our observations: the redshift distribution of COBRA sources with estimated redshifts peaks near z = 1 and extends out to z≈ 3. Cluster candidates were identified by comparing our target fields to a background field and searching for statistically significant (≥slant 2σ ) excesses in the galaxy number counts surrounding the radio sources; 190 fields satisfy the ≥slant 2σ limit. We find that 530 fields (82.0%) have a net positive excess of galaxies surrounding the radio source. Many of the fields with positive excesses but below the 2σ cutoff are likely to be galaxy groups. Forty-one COBRA sources are quasars with known spectroscopic redshifts, which may be tracers of some of the most distant clusters known.

  13. Randomised trial on episodic cluster headache with an angiotensin II receptor blocker

    DEFF Research Database (Denmark)

    Tronvik, Erling; Wienecke, Troels; Monstad, Inge

    2013-01-01

    OBJECTIVES: The aim of this study was to evaluate the angiotensin II receptor antagonist candesartan as prophylactic medication in patients with episodic cluster headache. METHODS: This study comprised a prospective, placebo-controlled, double-blind, parallel-designed trial performed in seven...... the candesartan and placebo group was not significant with the pre-planned non-parametric ranking test, but a post-hoc exact Poisson test, which takes into account the temporal properties of the data, revealed a significant result ( P  ...

  14. Automated search for galactic star clusters in large multiband surveys: I. Discovery of 15 new open clusters in the Galactic anticenter region

    OpenAIRE

    Koposov, S. E.; Glushkova, E. V.; Zolotukhin, I. Yu.

    2007-01-01

    Aims: According to some estimations, there are as many as 100000 open clusters in the Galaxy, but less than 2000 of them have been discovered, measured, and cataloged. We plan to undertake data mining of multiwavelength surveys to find new star clusters. Methods: We have developed a new method to search automatically for star clusters in very large stellar catalogs, which is based on convolution with density functions. We have applied this method to a subset of the Two Micron All Sky Survey c...

  15. Cosmological constraints from Galaxy Clusters in 2500 square-degree SPT-SZ survey

    Energy Technology Data Exchange (ETDEWEB)

    Haan, T. de; Benson, B. A.; Bleem, L. E.; Allen, S. W.; Applegate, D. E.; Ashby, M. L. N.; Bautz, M.; Bayliss, M.; Bocquet, S.; Brodwin, M.; Carlstrom, J. E.; Chang, C. L.; Chiu, I.; Cho, H-M.; Clocchiatti, A.; Crawford, T. M.; Crites, A. T.; Desai, S.; Dietrich, J. P.; Dobbs, M. A.; Doucouliagos, A. N.; Foley, R. J.; Forman, W. R.; Garmire, G. P.; George, E. M.; Gladders, M. D.; Gonzalez, A. H.; Gupta, N.; Halverson, N. W.; Hlavacek-Larrondo, J.; Hoekstra, H.; Holder, G. P.; Holzapfel, W. L.; Hou, Z.; Hrubes, J. D.; Huang, N.; Jones, C.; Keisler, R.; Knox, L.; Lee, A. T.; Leitch, E. M.; Linden, A. von der; Luong-Van, D.; Mantz, A.; Marrone, D. P.; McDonald, M.; McMahon, J. J.; Meyer, S. S.; Mocanu, L. M.; Mohr, J. J.; Murray, S. S.; Padin, S.; Pryke, C.; Rapetti, D.; Reichardt, C. L.; Rest, A.; Ruel, J.; Ruhl, J. E.; Saliwanchik, B. R.; Saro, A.; Sayre, J. T.; Schaffer, K. K.; Schrabback, T.; Shirokoff, E.; Song, J.; Spieler, H. G.; Stalder, B.; Stanford, S. A.; Staniszewski, Z.; Stark, A. A.; Story, K. T.; Stubbs, C. W.; Vanderlinde, K.; Vieira, J. D.; Vikhlinin, A.; Williamson, R.; Zenteno, A.

    2016-11-18

    We present cosmological parameter constraints obtained from galaxy clusters identified by their SunyaevZel'dovich effect signature in the 2500 square-degree South Pole Telescope Sunyaev Zel'dovich (SPT-SZ) survey. We consider the 377 cluster candidates identified at z > 0.25 with a detection significance greater than five, corresponding to the 95% purity threshold for the survey. We compute constraints on cosmological models using the measured cluster abundance as a function of mass and redshift. We include additional constraints from multi-wavelength observations, including Chandra X-ray data for 82 clusters and a weak lensing-based prior on the normalization of the mass-observable scaling relations. Assuming a spatially flat Lambda CDM cosmology, we combine the cluster data with a prior on H-0 and find sigma(8)= 0.784. +/- 0.039 and Omega(m) = 0.289. +/- 0.042, with the parameter combination sigma(8) (Omega(m)/0.27)(0.3) = 0.797 +/- 0.031. These results are in good agreement with constraints from the cosmic microwave background (CMB) from SPT, WMAP, and Planck, as well as with constraints from other cluster data sets. We also consider several extensions to Lambda CDM, including models in which the equation of state of dark energy w, the species-summed neutrino mass, and/or the effective number of relativistic species (N-eff) are free parameters. When combined with constraints from the Planck CMB, H-0, baryon acoustic oscillation, and SNe, adding the SPT cluster data improves the w constraint by 14%, to w = -1.023 +/- 0.042.

  16. The JCMT Gould Belt Survey: Dense Core Clusters in Orion A

    OpenAIRE

    Lane, J; Kirk, H; Johnstone, D.; Mairs, S.; Francesco, J. Di; Sadavoy, S.; Hatchell, J.; Berry, D. S.; Jenness, T.; Hogerheijde, M. R.; Ward-Thompson, Derek

    2016-01-01

    The Orion A molecular cloud is one of the most well-studied nearby star-forming regions, and includes regions of both highly clustered and more dispersed star formation across its full extent. Here, we analyze dense, star-forming cores identified in the 850 {\\mu}m and 450 {\\mu}m SCUBA-2 maps from the JCMT Gould Belt Legacy Survey. We identify dense cores in a uniform manner across the Orion A cloud and analyze their clustering properties. Using two independent lines of analysis, we find evide...

  17. Investigation of open clusters based on IPHAS and APASS survey data

    Science.gov (United States)

    Dambis, A. K.; Glushkova, E. V.; Berdnikov, L. N.; Joshi, Y. C.; Pandey, A. K.

    2017-02-01

    We adapt the classical Q-method based on a reddening-free parameter constructed from three passband magnitudes to the filter set of Isaac Newton Telescope Photometric Hα Survey and combine it with the maximum-likelihood-based cluster parameter estimator by Naylor & Jeffries (2006) to determine the extinction, heliocentric distances, and ages of young open clusters using Hαri data. The method is also adapted for the case of significant variations of extinction across the cluster field. Our technique is validated by comparing the colour excesses, distances, and ages determined in this study with the most bona fide values reported for the 18 well-studied young open clusters in the past and a fairly good agreement is found between our extinction and distance estimates and earlier published results, although our age estimates are not very consistent with those published by other authors. We also show that individual extinction values can be determined rather accurately for stars with (r - i) > 0.1. Our results open up a prospect for determining a uniform set of parameters for northern clusters based on homogeneous photometric data, and for searching for new, hitherto undiscovered open clusters.

  18. THE ACS VIRGO CLUSTER SURVEY. XVII. THE SPATIAL ALIGNMENT OF GLOBULAR CLUSTER SYSTEMS WITH EARLY-TYPE HOST GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Wang Qiushi; Peng, Eric W. [Department of Astronomy, Peking University, Beijing 100871 (China); Blakeslee, John P.; Cote, Patrick; Ferrarese, Laura [Herzberg Institute of Astrophysics, National Research Council of Canada, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Jordan, Andres [Departamento de Astronomia y Astrofisica, Pontificia Universidad Catolica de Chile, Casilla 306, Santiago 22 (Chile); Mei, Simona [University of Paris 7 Denis Diderot, F-75205 Paris Cedex 13 (France); West, Michael J., E-mail: peng@pku.edu.cn [Maria Mitchell Observatory, 4 Vestal Street, Nantucket, MA 02554 (United States)

    2013-06-01

    We study the azimuthal distribution of globular clusters (GCs) in early-type galaxies and compare them to their host galaxies using data from the ACS Virgo Cluster Survey. We find that in host galaxies with visible elongation ({epsilon} > 0.2) and intermediate to high luminosities (M{sub z} < -19), the GCs are preferentially aligned along the major axis of the stellar light. The red (metal-rich) GC subpopulations show strong alignment with the major axis of the host galaxy, which supports the notion that these GCs are associated with metal-rich field stars. The metal-rich GCs in lenticular galaxies show signs of being more strongly associated with disks rather than bulges. Surprisingly, we also find that the blue (metal-poor) GCs can also show the same correlation. If the metal-poor GCs are part of the early formation of the halo and built up through mergers, then our results support a picture where halo formation and merging occur anisotropically, and that the present-day major axis is an indicator of the preferred merging axis.

  19. The Next Generation Virgo Cluster Survey (NGVS). XXVI. The Issues of Photometric Age and Metallicity Estimates for Globular Clusters

    Science.gov (United States)

    Powalka, Mathieu; Lançon, Ariane; Puzia, Thomas H.; Peng, Eric W.; Liu, Chengze; Muñoz, Roberto P.; Blakeslee, John P.; Côté, Patrick; Ferrarese, Laura; Roediger, Joel; Sánchez-Janssen, Rúben; Zhang, Hongxin; Durrell, Patrick R.; Cuillandre, Jean-Charles; Duc, Pierre-Alain; Guhathakurta, Puragra; Gwyn, S. D. J.; Hudelot, Patrick; Mei, Simona; Toloba, Elisa

    2017-08-01

    Large samples of globular clusters (GC) with precise multi-wavelength photometry are becoming increasingly available and can be used to constrain the formation history of galaxies. We present the results of an analysis of Milky Way (MW) and Virgo core GCs based on 5 optical-near-infrared colors and 10 synthetic stellar population models. For the MW GCs, the models tend to agree on photometric ages and metallicities, with values similar to those obtained with previous studies. When used with Virgo core GCs, for which photometry is provided by the Next Generation Virgo cluster Survey (NGVS), the same models generically return younger ages. This is a consequence of the systematic differences observed between the locus occupied by Virgo core GCs and models in panchromatic color space. Only extreme fine-tuning of the adjustable parameters available to us can make the majority of the best-fit ages old. Although we cannot exclude that the formation history of the Virgo core may lead to more conspicuous populations of relatively young GCs than in other environments, we emphasize that the intrinsic properties of the Virgo GCs are likely to differ systematically from those assumed in the models. Thus, the large wavelength coverage and photometric quality of modern GC samples, such as those used here, is not by itself sufficient to better constrain the GC formation histories. Models matching the environment-dependent characteristics of GCs in multi-dimensional color space are needed to improve the situation.

  20. Weighing galaxy clusters with gas. II. On the origin of hydrostatic mass bias in ΛCDM galaxy clusters

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Kaylea; Nagai, Daisuke; Yu, Liang [Department of Astronomy, Yale University, New Haven, CT 06520 (United States); Lau, Erwin T.; Rudd, Douglas H., E-mail: kaylea.nelson@yale.edu [Department of Physics, Yale University, New Haven, CT 06520 (United States)

    2014-02-20

    The use of galaxy clusters as cosmological probes hinges on our ability to measure their masses accurately and with high precision. Hydrostatic mass is one of the most common methods for estimating the masses of individual galaxy clusters, which suffer from biases due to departures from hydrostatic equilibrium. Using a large, mass-limited sample of massive galaxy clusters from a high-resolution hydrodynamical cosmological simulation, in this work we show that in addition to turbulent and bulk gas velocities, acceleration of gas introduces biases in the hydrostatic mass estimate of galaxy clusters. In unrelaxed clusters, the acceleration bias is comparable to the bias due to non-thermal pressure associated with merger-induced turbulent and bulk gas motions. In relaxed clusters, the mean mass bias due to acceleration is small (≲ 3%), but the scatter in the mass bias can be reduced by accounting for gas acceleration. Additionally, this acceleration bias is greater in the outskirts of higher redshift clusters where mergers are more frequent and clusters are accreting more rapidly. Since gas acceleration cannot be observed directly, it introduces an irreducible bias for hydrostatic mass estimates. This acceleration bias places limits on how well we can recover cluster masses from future X-ray and microwave observations. We discuss implications for cluster mass estimates based on X-ray, Sunyaev-Zel'dovich effect, and gravitational lensing observations and their impact on cluster cosmology.

  1. The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. XIII. ACS/WFC Parallel-Field Catalogues★

    Science.gov (United States)

    Simioni, M.; Bedin, L. R.; Aparicio, A.; Piotto, G.; Milone, A. P.; Nardiello, D.; Anderson, J.; Bellini, A.; Brown, T. M.; Cassisi, S.; Cunial, A.; Granata, V.; Ortolani, S.; van der Marel, R. P.; Vesperini, E.

    2018-01-01

    As part of the Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters, 110 parallel fields were observed with the Wide Field Channel of the Advanced Camera for Surveys, in the outskirts of 48 globular clusters, plus the open cluster NGC 6791. Totalling about 0.3 square degrees of observed sky, this is the largest homogeneous Hubble Space Telescope photometric survey of Galalctic globular clusters outskirts to date. In particular, two distinct pointings have been obtained for each target on average, all centred at about 6.5 arcmin from the cluster centre, thus covering a mean area of about 23 arcmin2 for each globular cluster. For each field, at least one exposure in both F475W and F814W filters was collected. In this work, we publicly release the astrometric and photometric catalogues and the astrometrised atlases for each of these fields.

  2. Clustering of far-infrared galaxies in the AKARI All-Sky Survey North

    Science.gov (United States)

    Pollo, A.; Takeuchi, T. T.; Solarz, A.; Rybka, P.; Suzuki, T. L.; Pȩpiak, A.; Oyabu, S.

    2013-10-01

    We present the measurements of the angular two-point correlation function for AKARI 90-μm point sources, detected outside the Milky Way plane and other regions characterized by high Galactic extinction in the northern Galactic hemisphere, and categorized as extragalactic sources according to our far-infrared-color based criterion. Together with our previous work (Pollo et al., 2013) this is the first measurement of the large-scale angular clustering of galaxies selected in the far-infrared after IRAS. We present the first attempt to estimate the spatial clustering properties of AKARI All-Sky galaxies and we conclude that they are mostly a very nearby ( z ≤ 0.1) population of moderately clustered galaxies. We measure their correlation length r 0 ~ 4.5 h -1 Mpc, which is consistent with the assumption that the FIS AKARI All-Sky surveys observes mostly a nearby star-forming population of galaxies.

  3. Metallothionein-like multinuclear clusters of mercury(II) and sulfur in peat

    Science.gov (United States)

    Nagy, K.L.; Manceau, A.; Gasper, J.D.; Ryan, J.N.; Aiken, G.R.

    2011-01-01

    Strong mercury(II)-sulfur (Hg-SR) bonds in natural organic matter, which influence mercury bioavailability, are difficult to characterize. We report evidence for two new Hg-SR structures using X-ray absorption spectroscopy in peats from the Florida Everglades with added Hg. The first, observed at a mole ratio of organic reduced S to Hg (Sred/Hg) between 220 and 1140, is a Hg4Sx type of cluster with each Hg atom bonded to two S atoms at 2.34 ?? and one S at 2.53 ??, and all Hg atoms 4.12 ?? apart. This model structure matches those of metal-thiolate clusters in metallothioneins, but not those of HgS minerals. The second, with one S atom at 2.34 ?? and about six C atoms at 2.97 to 3.28 ??, occurred at S red/Hg between 0.80 and 4.3 and suggests Hg binding to a thiolated aromatic unit. The multinuclear Hg cluster indicates a strong binding environment to cysteinyl sulfur that might impede methylation. Along with a linear Hg(SR)2 unit with Hg - S bond lengths of 2.34 ?? at Sred/Hg of about 10 to 20, the new structures support a continuum in Hg-SR binding strength in natural organic matter. ?? 2011 American Chemical Society.

  4. The Data Release of the Sloan Digital Sky Survey-II Supernova Survey

    Energy Technology Data Exchange (ETDEWEB)

    Sako, Masao; et al.

    2014-01-14

    This paper describes the data release of the Sloan Digital Sky Survey-II (SDSS-II) Supernova Survey conducted between 2005 and 2007. Light curves, spectra, classifications, and ancillary data are presented for 10,258 variable and transient sources discovered through repeat ugriz imaging of SDSS Stripe 82, a 300 deg2 area along the celestial equator. This data release is comprised of all transient sources brighter than r~22.5 mag with no history of variability prior to 2004. Dedicated spectroscopic observations were performed on a subset of 889 transients, as well as spectra for thousands of transient host galaxies using the SDSS-III BOSS spectrographs. Photometric classifications are provided for the candidates with good multi-color light curves that were not observed spectroscopically. From these observations, 4607 transients are either spectroscopically confirmed, or likely to be, supernovae, making this the largest sample of supernova candidates ever compiled. We present a new method for SN host-galaxy identification and derive host-galaxy properties including stellar masses, star-formation rates, and the average stellar population ages from our SDSS multi-band photometry. We derive SALT2 distance moduli for a total of 1443 SN Ia with spectroscopic redshifts as well as photometric redshifts for a further 677 purely-photometric SN Ia candidates. Using the spectroscopically confirmed subset of the three-year SDSS-II SN Ia sample and assuming a flat Lambda-CDM cosmology, we determine Omega_M = 0.315 +/- 0.093 (statistical error only) and detect a non-zero cosmological constant at 5.7 sigmas.

  5. VizieR Online Data Catalog: HST/ACS Coma Cluster Survey. X. (den Brok+, 2014)

    NARCIS (Netherlands)

    den Brok, M.; Peletier, R. F.; Seth, A.; Balcells, M.; Dominguez, L.; Graham, A. W.; Carter, D.; Erwin, P.; Ferguson, H. C.; Goudfrooij, P.; Guzman, R.; Hoyos, C.; Jogee, S.; Lucey, J.; Phillipps, S.; Puzia, T.; Valentijn, E.; Kleijn, G. V.; Weinzirl, T.

    2014-01-01

    The Coma ACS Survey (Carter et al., 2008ApJS..176..424C) provides data in two passbands for 25 fields pointed at the core of the Coma cluster and at the outskirts. The exposure times in the two passbands, F814W and F475W (which are roughly equivalent to the IC and g band) were ~1400 and ~2600s. The

  6. Mass and galaxy distributions of four massive galaxy clusters from Dark Energy Survey Science Verification data

    Energy Technology Data Exchange (ETDEWEB)

    Melchior, P.; Suchyta, E.; Huff, E.; Hirsch, M.; Kacprzak, T.; Rykoff, E.; Gruen, D.; Armstrong, R.; Bacon, D.; Bechtol, K.; Bernstein, G. M.; Bridle, S.; Clampitt, J.; Honscheid, K.; Jain, B.; Jouvel, S.; Krause, E.; Lin, H.; MacCrann, N.; Patton, K.; Plazas, A.; Rowe, B.; Vikram, V.; Wilcox, H.; Young, J.; Zuntz, J.; Abbott, T.; Abdalla, F. B.; Allam, S. S.; Banerji, M.; Bernstein, J. P.; Bernstein, R. A.; Bertin, E.; Buckley-Geer, E.; Burke, D. L.; Castander, F. J.; da Costa, L. N.; Cunha, C. E.; Depoy, D. L.; Desai, S.; Diehl, H. T.; Doel, P.; Estrada, J.; Evrard, A. E.; Neto, A. F.; Fernandez, E.; Finley, D. A.; Flaugher, B.; Frieman, J. A.; Gaztanaga, E.; Gerdes, D.; Gruendl, R. A.; Gutierrez, G. R.; Jarvis, M.; Karliner, I.; Kent, S.; Kuehn, K.; Kuropatkin, N.; Lahav, O.; Maia, M. A. G.; Makler, M.; Marriner, J.; Marshall, J. L.; Merritt, K. W.; Miller, C. J.; Miquel, R.; Mohr, J.; Neilsen, E.; Nichol, R. C.; Nord, B. D.; Reil, K.; Roe, N. A.; Roodman, A.; Sako, M.; Sanchez, E.; Santiago, B. X.; Schindler, R.; Schubnell, M.; Sevilla-Noarbe, I.; Sheldon, E.; Smith, C.; Soares-Santos, M.; Swanson, M. E. C.; Sypniewski, A. J.; Tarle, G.; Thaler, J.; Thomas, D.; Tucker, D. L.; Walker, A.; Wechsler, R.; Weller, J.; Wester, W.

    2015-03-31

    We measure the weak lensing masses and galaxy distributions of four massive galaxy clusters observed during the Science Verification phase of the Dark Energy Survey (DES). This pathfinder study is meant to (1) validate the Dark Energy Camera (DECam) imager for the task of measuring weak lensing shapes, and (2) utilize DECam's large field of view to map out the clusters and their environments over 90 arcmin. We conduct a series of rigorous tests on astrometry, photometry, image quality, point spread function (PSF) modelling, and shear measurement accuracy to single out flaws in the data and also to identify the optimal data processing steps and parameters. We find Science Verification data from DECam to be suitable for the lensing analysis described in this paper. The PSF is generally well behaved, but the modelling is rendered difficult by a flux-dependent PSF width and ellipticity. We employ photometric redshifts to distinguish between foreground and background galaxies, and a red-sequence cluster finder to provide cluster richness estimates and cluster-galaxy distributions. By fitting Navarro-Frenk-White profiles to the clusters in this study, we determine weak lensing masses that are in agreement with previous work. For Abell 3261, we provide the first estimates of redshift, weak lensing mass, and richness. In addition, the cluster-galaxy distributions indicate the presence of filamentary structures attached to 1E 0657-56 and RXC J2248.7-4431, stretching out as far as 1. (approximately 20 Mpc), showcasing the potential of DECam and DES for detailed studies of degree-scale features on the sky.

  7. Mass and galaxy distributions of four massive galaxy clusters from Dark Energy Survey Science Verification data

    Energy Technology Data Exchange (ETDEWEB)

    Melchior, P.; Suchyta, E.; Huff, E.; Hirsch, M.; Kacprzak, T.; Rykoff, E.; Gruen, D.; Armstrong, R.; Bacon, D.; Bechtol, K.; Bernstein, G. M.; Bridle, S.; Clampitt, J.; Honscheid, K.; Jain, B.; Jouvel, S.; Krause, E.; Lin, H.; MacCrann, N.; Patton, K.; Plazas, A.; Rowe, B.; Vikram, V.; Wilcox, H.; Young, J.; Zuntz, J.; Abbott, T.; Abdalla, F. B.; Allam, S. S.; Banerji, M.; Bernstein, J. P.; Bernstein, R. A.; Bertin, E.; Buckley-Geer, E.; Burke, D. L.; Castander, F. J.; da Costa, L. N.; Cunha, C. E.; Depoy, D. L.; Desai, S.; Diehl, H. T.; Doel, P.; Estrada, J.; Evrard, A. E.; Neto, A. F.; Fernandez, E.; Finley, D. A.; Flaugher, B.; Frieman, J. A.; Gaztanaga, E.; Gerdes, D.; Gruendl, R. A.; Gutierrez, G. R.; Jarvis, M.; Karliner, I.; Kent, S.; Kuehn, K.; Kuropatkin, N.; Lahav, O.; Maia, M. A. G.; Makler, M.; Marriner, J.; Marshall, J. L.; Merritt, K. W.; Miller, C. J.; Miquel, R.; Mohr, J.; Neilsen, E.; Nichol, R. C.; Nord, B. D.; Reil, K.; Roe, N. A.; Roodman, A.; Sako, M.; Sanchez, E.; Santiago, B. X.; Schindler, R.; Schubnell, M.; Sevilla-Noarbe, I.; Sheldon, E.; Smith, C.; Soares-Santos, M.; Swanson, M. E. C.; Sypniewski, A. J.; Tarle, G.; Thaler, J.; Thomas, D.; Tucker, D. L.; Walker, A.; Wechsler, R.; Weller, J.; Wester, W.

    2015-03-31

    We measure the weak-lensing masses and galaxy distributions of four massive galaxy clusters observed during the Science Verification phase of the Dark Energy Survey. This pathfinder study is meant to 1) validate the DECam imager for the task of measuring weak-lensing shapes, and 2) utilize DECam's large field of view to map out the clusters and their environments over 90 arcmin. We conduct a series of rigorous tests on astrometry, photometry, image quality, PSF modeling, and shear measurement accuracy to single out flaws in the data and also to identify the optimal data processing steps and parameters. We find Science Verification data from DECam to be suitable for the lensing analysis described in this paper. The PSF is generally well-behaved, but the modeling is rendered difficult by a flux-dependent PSF width and ellipticity. We employ photometric redshifts to distinguish between foreground and background galaxies, and a red-sequence cluster finder to provide cluster richness estimates and cluster-galaxy distributions. By fitting NFW profiles to the clusters in this study, we determine weak-lensing masses that are in agreement with previous work. For Abell 3261, we provide the first estimates of redshift, weak-lensing mass, and richness. In addition, the cluster-galaxy distributions indicate the presence of filamentary structures attached to 1E 0657-56 and RXC J2248.7-4431, stretching out as far as 1 degree (approximately 20 Mpc), showcasing the potential of DECam and DES for detailed studies of degree-scale features on the sky.

  8. Searching for globular cluster-like abundance patterns in young massive clusters - II. Results from the Antennae galaxies

    Science.gov (United States)

    Lardo, C.; Cabrera-Ziri, I.; Davies, B.; Bastian, N.

    2017-06-01

    The presence of multiple populations (MPs) with distinctive light element abundances is a widespread phenomenon in clusters older than 6 Gyr. Clusters with masses, luminosities, and sizes comparable to those of ancient globulars are still forming today. None the less, the presence of light element variations has been poorly investigated in such young systems, even if the knowledge of the age at which this phenomenon develops is crucial for theoretical models on MPs. We use J-band integrated spectra of three young (7-40 Myr) clusters in NGC 4038 to look for Al variations indicative of MPs. Assuming that the large majority (≥70 per cent) of stars are characterized by high Al content - as observed in Galactic clusters with comparable mass; we find that none of the studied clusters show significant Al variations. Small Al spreads have been measured in all the six young clusters observed in the near-infrared. While it is unlikely that young clusters only show low Al whereas old ones display different levels of Al variations; this suggests the possibility that MPs are not present at such young ages at least among the high-mass stellar component. Alternatively, the fraction of stars with field-like chemistry could be extremely large, mimicking low Al abundances in the integrated spectrum. Finally, since the near-infrared stellar continuum of young clusters is almost entirely due to luminous red supergiants, we can also speculate that MPs only manifest themselves in low-mass stars due to some evolutionary mechanism.

  9. The outer envelopes of globular clusters. II. NGC 1851, NGC 5824 and NGC 1261*

    Science.gov (United States)

    Kuzma, P. B.; Da Costa, G. S.; Mackey, A. D.

    2018-01-01

    We present a second set of results from a wide-field photometric survey of the environs of Milky Way globular clusters. The clusters studied are NGC 1261, NGC 1851 and NGC 5824: all have data from the Dark Energy Camera on the Blanco 4 m telescope. NGC 5824 also has data from the Magellan Clay telescope with MegaCam. We confirm the existence of a large diffuse stellar envelope surrounding NGC 1851 of size at least 240 pc in radius. The radial density profile of the envelope follows a power-law decline with index γ = -1.5 ± 0.2 and the projected shape is slightly elliptical. For NGC 5824, there is no strong detection of a diffuse stellar envelope, but we find the cluster is remarkably extended and is similar in size (at least 230 pc in radius) to the envelope of NGC 1851. A stellar envelope is also revealed around NGC 1261. However, it is notably smaller in size with radius ∼105 pc. The radial density profile of the envelope is also much steeper with γ = -3.8 ± 0.2. We discuss the possible nature of the diffuse stellar envelopes, but are unable to draw definitive conclusions based on the current data. NGC 1851, and potentially NGC 5824, could be stripped dwarf galaxy nuclei, akin to the cases of ω Cen, M54 and M2. On the other hand, the different characteristics of the NGC 1261 envelope suggest that it may be the product of dynamical evolution of the cluster.

  10. Dark Energy Survey Year 1 Results: Cosmological Constraints from Galaxy Clustering and Weak Lensing

    Energy Technology Data Exchange (ETDEWEB)

    Abbott, T.M.C.; et al.

    2017-08-04

    We present cosmological results from a combined analysis of galaxy clustering and weak gravitational lensing, using 1321 deg$^2$ of $griz$ imaging data from the first year of the Dark Energy Survey (DES Y1). We combine three two-point functions: (i) the cosmic shear correlation function of 26 million source galaxies in four redshift bins, (ii) the galaxy angular autocorrelation function of 650,000 luminous red galaxies in five redshift bins, and (iii) the galaxy-shear cross-correlation of luminous red galaxy positions and source galaxy shears. To demonstrate the robustness of these results, we use independent pairs of galaxy shape, photometric redshift estimation and validation, and likelihood analysis pipelines. To prevent confirmation bias, the bulk of the analysis was carried out while blind to the true results; we describe an extensive suite of systematics checks performed and passed during this blinded phase. The data are modeled in flat $\\Lambda$CDM and $w$CDM cosmologies, marginalizing over 20 nuisance parameters, varying 6 (for $\\Lambda$CDM) or 7 (for $w$CDM) cosmological parameters including the neutrino mass density and including the 457 $\\times$ 457 element analytic covariance matrix. We find consistent cosmological results from these three two-point functions, and from their combination obtain $S_8 \\equiv \\sigma_8 (\\Omega_m/0.3)^{0.5} = 0.783^{+0.021}_{-0.025}$ and $\\Omega_m = 0.264^{+0.032}_{-0.019}$ for $\\Lambda$CDM for $w$CDM, we find $S_8 = 0.794^{+0.029}_{-0.027}$, $\\Omega_m = 0.279^{+0.043}_{-0.022}$, and $w=-0.80^{+0.20}_{-0.22}$ at 68% CL. The precision of these DES Y1 results rivals that from the Planck cosmic microwave background measurements, allowing a comparison of structure in the very early and late Universe on equal terms. Although the DES Y1 best-fit values for $S_8$ and $\\Omega_m$ are lower than the central values from Planck ...

  11. CA II TRIPLET SPECTROSCOPY OF SMALL MAGELLANIC CLOUD RED GIANTS. III. ABUNDANCES AND VELOCITIES FOR A SAMPLE OF 14 CLUSTERS

    Energy Technology Data Exchange (ETDEWEB)

    Parisi, M. C.; Clariá, J. J.; Marcionni, N. [Observatorio Astronómico, Universidad Nacional de Córdoba, Laprida 854, Córdoba, CP 5000 (Argentina); Geisler, D.; Villanova, S. [Departamento de Astronomía, Universidad de Concepción Casilla 160-C, Concepción (Chile); Sarajedini, A. [Department of Astronomy, University of Florida P.O. Box 112055, Gainesville, FL 32611 (United States); Grocholski, A. J., E-mail: celeste@oac.uncor.edu, E-mail: claria@oac.uncor.edu, E-mail: nmarcionni@oac.uncor.edu, E-mail: dgeisler@astro-udec.cl, E-mail: svillanova@astro-udec.cl, E-mail: ata@astro.ufl.edu, E-mail: grocholski@phys.lsu.edu [Department of Physics and Astronomy, Louisiana State University 202 Nicholson Hall, Tower Drive, Baton Rouge, LA 70803-4001 (United States)

    2015-05-15

    We obtained spectra of red giants in 15 Small Magellanic Cloud (SMC) clusters in the region of the Ca ii lines with FORS2 on the Very Large Telescope. We determined the mean metallicity and radial velocity with mean errors of 0.05 dex and 2.6 km s{sup −1}, respectively, from a mean of 6.5 members per cluster. One cluster (B113) was too young for a reliable metallicity determination and was excluded from the sample. We combined the sample studied here with 15 clusters previously studied by us using the same technique, and with 7 clusters whose metallicities determined by other authors are on a scale similar to ours. This compilation of 36 clusters is the largest SMC cluster sample currently available with accurate and homogeneously determined metallicities. We found a high probability that the metallicity distribution is bimodal, with potential peaks at −1.1 and −0.8 dex. Our data show no strong evidence of a metallicity gradient in the SMC clusters, somewhat at odds with recent evidence from Ca ii triplet spectra of a large sample of field stars. This may be revealing possible differences in the chemical history of clusters and field stars. Our clusters show a significant dispersion of metallicities, whatever age is considered, which could be reflecting the lack of a unique age–metallicity relation in this galaxy. None of the chemical evolution models currently available in the literature satisfactorily represents the global chemical enrichment processes of SMC clusters.

  12. The Gaia-ESO Survey: Structural and dynamical properties of the young cluster Chamaeleon I

    Science.gov (United States)

    Sacco, G. G.; Spina, L.; Randich, S.; Palla, F.; Parker, R. J.; Jeffries, R. D.; Jackson, R.; Meyer, M. R.; Mapelli, M.; Lanzafame, A. C.; Bonito, R.; Damiani, F.; Franciosini, E.; Frasca, A.; Klutsch, A.; Prisinzano, L.; Tognelli, E.; Degl'Innocenti, S.; Prada Moroni, P. G.; Alfaro, E. J.; Micela, G.; Prusti, T.; Barrado, D.; Biazzo, K.; Bouy, H.; Bravi, L.; Lopez-Santiago, J.; Wright, N. J.; Bayo, A.; Gilmore, G.; Bragaglia, A.; Flaccomio, E.; Koposov, S. E.; Pancino, E.; Casey, A. R.; Costado, M. T.; Donati, P.; Hourihane, A.; Jofré, P.; Lardo, C.; Lewis, J.; Magrini, L.; Monaco, L.; Morbidelli, L.; Sousa, S. G.; Worley, C. C.; Zaggia, S.

    2017-05-01

    Investigating the physical mechanisms driving the dynamical evolution of young star clusters is fundamental to our understanding of the star formation process and the properties of the Galactic field stars. The young ( 2 Myr) and partially embedded cluster Chamaeleon I is one of the closest laboratories for the study of the early stages of star cluster dynamics in a low-density environment. The aim of this work is to study the structural and kinematical properties of this cluster combining parameters from the high-resolution spectroscopic observations of the Gaia-ESO Survey with data from the literature. Our main result is the evidence of a large discrepancy between the velocity dispersion (σstars = 1.14 ± 0.35 km s-1) of the stellar population and the dispersion of the pre-stellar cores ( 0.3 km s-1) derived from submillimeter observations. The origin of this discrepancy, which has been observed in other young star clusters, is not clear. It has been suggested that it may be due to either the effect of the magnetic field on the protostars and the filaments or to the dynamical evolution of stars driven by two-body interactions. Furthermore, the analysis of the kinematic properties of the stellar population puts in evidence a significant velocity shift ( 1 km s-1) between the two subclusters located around the north and south main clouds of the cluster. This result further supports a scenario where clusters form from the evolution of multiple substructures rather than from a monolithic collapse. Using three independent spectroscopic indicators (the gravity indicator γ, the equivalent width of the Li line at 6708 Å, and the Hα 10% width), we performed a new membership selection. We found six new cluster members all located in the outer region of the cluster, proving that Chamaeleon I is probably more extended than previously thought. Starting from the positions and masses of the cluster members, we derived the level of substructure Q, the surface density Σ, and

  13. Automated search for Galactic star clusters in large multiband surveys. I. Discovery of 15 new open clusters in the Galactic anticenter region

    Science.gov (United States)

    Koposov, S. E.; Glushkova, E. V.; Zolotukhin, I. Yu.

    2008-08-01

    Aims: According to some estimations, there are as many as 100 000 open clusters in the Galaxy, but less than 2000 of them have been discovered, measured, and cataloged. We plan to undertake data mining of multiwavelength surveys to find new star clusters. Methods: We have developed a new method to search automatically for star clusters in very large stellar catalogs, which is based on convolution with density functions. We have applied this method to a subset of the Two Micron All Sky Survey catalog toward the Galactic anticenter. We also developed a method to verify whether detected stellar groups are real star clusters, which tests whether the stars that form the spatial density peak also fall onto a single isochrone in the color-magnitude diagram. By fitting an isochrone to the data, we estimate at the same time the main physical parameters of a cluster: age, distance, color excess. Results: For the present paper, we carried out a detailed analysis of 88 overdensity peaks detected in a field of 16×16 degrees near the Galactic anticenter. From this analysis, 15 overdensities were confirmed to be new open clusters and the physical and structural parameters were determined for 12 of them; 10 of them were previously suspected to be open clusters by Kronberger (2006) and Froebrich (2007). The properties were also determined for 13 yet-unstudied known open clusters, thus almost tripling the sample of open clusters with studied parameters in the anticenter. The parameters determined with this method showed a good agreement with published data for a set of well-known clusters. Figures 7-18 and Table 3 are only available in electronic form at http://www.aanda.org

  14. Molecule-Based Magnets: Ferro- and Antiferromagnetic Interactions in Copper(II)-Polyorganosiloxanolate Clusters.

    Science.gov (United States)

    Rentschler, Eva; Gatteschi, Dante; Cornia, Andrea; Fabretti, Antonio C.; Barra, Anne-Laure; Shchegolikhina, Olga I.; Zhdanov, Alexandr A.

    1996-07-17

    The magnetic behavior of the clusters [(PhSiO(2))(6)Cu(6)(O(2)SiPh)(6)].6EtOH (1), Na(4)[(PhSiO(2))(12)Cu(4)].8(n)()BuOH (2), and K(4)[(C(2)H(3)SiO(2))(12)Cu(4)].6(n)()BuOH (3) has been investigated by combined magnetic susceptibility measurements and variable-temperature EPR techniques (9.25 and 245 GHz). The six copper(II) ions in the core of 1, which approaches 6/mmm symmetry, are ferromagnetically coupled as a result of the geometry at the bridging siloxanolate oxygen atoms (Cu-O-Cu = 91.5-94.6 degrees; J = -42 cm(-)(1) with H = J S(i)().S(i)()(+1), S(7) = S(1)). The ground S = 3 spin state is split in zero field mainly due to anisotropic exchange contributions (D = 0.30 cm(-)(1)). Notably, both the magnitude and the sign of the zero-field splitting parameter have been determined from HF-EPR spectra. Large antiferromagnetic Cu-Cu interactions (J approximately 200 cm(-)(1)) and an S = 0 ground state have been detected in the tetranuclear clusters 2 and 3 as a consequence of the larger Cu-O-Cu angles. The results presented in the paper are relevant to the search for new molecule-based magnetic materials.

  15. Magnetism of a novel tetranuclear nickel(II) cluster in strong magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Kataev, V [Leibniz-Institute for Solid State and Materials Research IFW Dresden, PO Box 270116, 01171 Dresden (Germany); Golze, C [Leibniz-Institute for Solid State and Materials Research IFW Dresden, PO Box 270116, 01171 Dresden (Germany); Alfonsov, A [Kazan Physical Technical Institute, Russian Academy of Sciences, 420029 Kazan (Russian Federation); Klingeler, R [Leibniz-Institute for Solid State and Materials Research IFW Dresden, PO Box 270116, 01171 Dresden (Germany); Buechner, B [Leibniz-Institute for Solid State and Materials Research IFW Dresden, PO Box 270116, 01171 Dresden (Germany); Goiran, M [Laboratoire National des Champs Magnetiques Pulses, 31432 Toulouse Cedex 04 (France); Broto, J-M [Laboratoire National des Champs Magnetiques Pulses, 31432 Toulouse Cedex 04 (France); Rakoto, H [Laboratoire National des Champs Magnetiques Pulses, 31432 Toulouse Cedex 04 (France); Mennerich, C [Institut fuer Physik der Kondens. Materie, TU Braunschweig, 38106 Braunschweig (Germany); Klauss, H-H [Institut fuer Physik der Kondens. Materie, TU Braunschweig, 38106 Braunschweig (Germany); Demeshko, S [Georg-August-University Goettingen, Institute of Inorg. Chem., 37077 Goettingen (Germany); Leibeling, G [Georg-August-University Goettingen, Institute of Inorg. Chem., 37077 Goettingen (Germany); Meyer, F [Georg-August-University Goettingen, Institute of Inorg. Chem., 37077 Goettingen (Germany)

    2006-11-15

    High frequency Electron Spin Resonance (ESR) up to {nu} = 1 THz and magnetization M(B) of a tetranuclear-Ni(II) single molecular complex of type [L{sub 2}Ni{sub 4}(N{sub 3})(O{sub 2}CAda){sub 4}](ClO{sub 4}) featuring an unprecedented central {mu}{sub 4} - 1,1,3,3 azide have been studied in magnetic fields up to B = 55T. Bridging ligands provide intramolecular exchange paths of different strength between the four Ni ions each having a spin S{sub Ni} = 1. T- and {nu}-dependent ESR measurements enable to accurately determine the energy spectrum of the spin states of the cluster as a function of B. A predominantly antiferromagnetic character of exchange renders the ground state nonmagnetic, S = 0, with a number of excited magnetic multiplet states, S = 1,. . . ,4. Remarkably, ESR gives evidence for the spin-level crossing in a field of {approx} 25T which turns the ground state of the cluster to a strongly magnetic one. This observation is confirmed by the static M(B) data.

  16. Human paraoxonase gene cluster overexpression alleviates angiotensin II-induced cardiac hypertrophy in mice.

    Science.gov (United States)

    Pei, Jian-Fei; Yan, Yun-Fei; Tang, Xiaoqiang; Zhang, Yang; Cui, Shen-Shen; Zhang, Zhu-Qin; Chen, Hou-Zao; Liu, De-Pei

    2016-11-01

    Cardiac hypertrophy is the strongest predictor of the development of heart failure, and anti-hypertrophic treatment holds the key to improving the clinical syndrome and increasing the survival rates for heart failure. The paraoxonase (PON) gene cluster (PC) protects against atherosclerosis and coronary artery diseases. However, the role of PC in the heart is largely unknown. To evaluate the roles of PC in cardiac hypertrophy, transgenic mice carrying the intact human PON1, PON2, and PON3 genes and their flanking sequences were studied. We demonstrated that the PC transgene (PC-Tg) protected mice from cardiac hypertrophy induced by Ang II; these mice had reduced heart weight/body weight ratios, decreased left ventricular wall thicknesses and increased fractional shortening compared with wild-type (WT) control. The same protective tendency was also observed with an Apoe -/- background. Mechanically, PC-Tg normalized the disequilibrium of matrix metalloproteinases (MMPs)/tissue inhibitors of MMPs (TIMPs) in hypertrophic hearts, which might contribute to the protective role of PC-Tg in cardiac fibrosis and, thus, protect against cardiac remodeling. Taken together, our results identify a novel anti-hypertrophic role for the PON gene cluster, suggesting a possible strategy for the treatment of cardiac hypertrophy through elevating the levels of the PON gene family.

  17. Calibrating the lithium-age relation with open clusters observed with GES (Gaia-ESO Survey)

    Science.gov (United States)

    Gutiérrez Albarrán, M. L.; Montes, D.; Gómez Garrido, M.; Tabernero, H. M..; González Hernández, J. I.; GES Survey Builders

    2017-03-01

    Li depletion is strongly age-dependent but currently available data have shown a complex pattern of Li depletion on the pre- and main-sequence stars that is not yet understood. The lithium abundance observed in late-type stars depend not only of the age and the temperature but also on metallicity, mixing mechanisms, convection structure, rotation and magnetic activity. The large number of stars observed within the Gaia-ESO survey (GES - https://www.gaia-eso.eu/) for many open clusters and associations can be used to calibrate the lithium-age relation and its dependence with other parameters that can be derived from the UVES and GIRAFFE spectroscopic observations. We present here the preliminary results of the analysis of membership and Li abundance of the young clusters and associations, as well as of the intermediate-age and old open clusters, observed until now in GES (iDR4) in order to conduct a comparative study. All this information allowed us to characterize the properties of the members of these clusters and identify a series of field contaminant stars, both lithium-rich giants and non-giant outliers.

  18. Detailed studies om three open clusters from Gaia ESO Survey (GES)

    Science.gov (United States)

    Balaguer-Núnez, L.; Casamiquela, L.; Jordana, N.; Massana, P.; Jordi, C.; Masana, E.

    2017-03-01

    We present results for the intermediate-age and old open clusters NGC 6633, NGC 6705 (M 11) and NGC 2682 (M 67). We have used new Str ̈omgren-Crawford photometry, proper motions from ROA observations and spectral information from Gaia-ESO Survey (GES), to study the physical parameters of the stars in the three cluster's areas. The astrometric studies cover an area of about 1°x2° and down to r' ˜ 17 while our INT-WFC CCD intermediate-band photometry covers an area of about 40'x40' down to V ˜ 19. The stars of those areas selected as cluster members from their proper motions, are classified into photometric regions and their physical parameters determined, using uvbyHβ photometry and standard relations among colour indices for each of the photometric regions of the HR diagram. That allows us to determine reddening, distances, absolute magnitudes, spectral types, effective temperatures, gravities and metallicities, thus providing an astrophysical characterization of the clusters. These results are compared with the physical parameters obtained from GES spectral data as well as radial velocities to confirm membership. All these data lead us to a comparison of photometric and spectroscopic physical parameters.

  19. Probing dark matter with star clusters: a dark matter core in the ultra-faint dwarf Eridanus II

    Science.gov (United States)

    Contenta, Filippo; Balbinot, Eduardo; Petts, James A.; Read, Justin I.; Gieles, Mark; Collins, Michelle L. M.; Peñarrubia, Jorge; Delorme, Maxime; Gualandris, Alessia

    2018-02-01

    We present a new technique to probe the central dark matter (DM) density profile of galaxies that harnesses both the survival and observed properties of star clusters. As a first application, we apply our method to the `ultra-faint' dwarf Eridanus II (Eri II) that has a lone star cluster ˜45 pc from its centre. Using a grid of collisional N-body simulations, incorporating the effects of stellar evolution, external tides and dynamical friction, we show that a DM core for Eri II naturally reproduces the size and the projected position of its star cluster. By contrast, a dense cusped galaxy requires the cluster to lie implausibly far from the centre of Eri II (>1 kpc), with a high inclination orbit that must be observed at a particular orbital phase. Our results, therefore, favour a dark matter core. This implies that either a cold DM cusp was `heated up' at the centre of Eri II by bursty star formation, or we are seeing an evidence for physics beyond cold DM.

  20. The XXL Survey. XIII. Baryon content of the bright cluster sample

    Science.gov (United States)

    Eckert, D.; Ettori, S.; Coupon, J.; Gastaldello, F.; Pierre, M.; Melin, J.-B.; Le Brun, A. M. C.; McCarthy, I. G.; Adami, C.; Chiappetti, L.; Faccioli, L.; Giles, P.; Lavoie, S.; Lefèvre, J. P.; Lieu, M.; Mantz, A.; Maughan, B.; McGee, S.; Pacaud, F.; Paltani, S.; Sadibekova, T.; Smith, G. P.; Ziparo, F.

    2016-06-01

    Traditionally, galaxy clusters have been expected to retain all the material accreted since their formation epoch. For this reason, their matter content should be representative of the Universe as a whole, and thus their baryon fraction should be close to the Universal baryon fraction Ωb/ Ωm. We make use of the sample of the 100 brightest galaxy clusters discovered in the XXL Survey to investigate the fraction of baryons in the form of hot gas and stars in the cluster population. Since it spans a wide range of mass (1013-1015 M⊙) and redshift (0.05-1.1) and benefits from a large set of multiwavelength data, the XXL-100-GC sample is ideal for measuring the global baryon budget of massive halos. We measure the gas masses of the detected halos and use a mass-temperature relation directly calibrated using weak-lensing measurements for a subset of XXL clusters to estimate the halo mass. We find that the weak-lensing calibrated gas fraction of XXL-100-GC clusters is substantially lower than was found in previous studies using hydrostatic masses. Our best-fit relation between gas fraction and mass reads fgas,500 = 0.055-0.006+0.007(M500/1014 M⊙)0.21-0.10+0.11. The baryon budget of galaxy clusters therefore falls short of the Universal baryon fraction by about a factor of two at r500,MT. Our measurements require a hydrostatic bias 1-b = MX/MWL = 0.72-0.07+0.08 to match the gas fraction obtained using lensing and hydrostatic equilibrium, which holds independently of the instrument considered. Comparing our gas fraction measurements with the expectations from numerical simulations, we find that our results favour an extreme feedback scheme in which a significant fraction of the baryons are expelled from the cores of halos. This model is, however, in contrast with the thermodynamical properties of observed halos, which might suggest that weak-lensing masses are overestimated. In light of these results, we note that a mass bias 1-b = 0.58 as required to reconcile Planck

  1. Cluster galaxy population evolution from the Subaru Hyper Suprime-Cam survey: brightest cluster galaxies, stellar mass distribution, and active galaxies

    Science.gov (United States)

    Lin, Yen-Ting; Hsieh, Bau-Ching; Lin, Sheng-Chieh; Oguri, Masamune; Chen, Kai-Feng; Tanaka, Masayuki; Chiu, I.-non; Huang, Song; Kodama, Tadayuki; Leauthaud, Alexie; More, Surhud; Nishizawa, Atsushi; Bundy, Kevin; Lin, Lihwai; Miyazaki, Satoshi; HSC Collaboration

    2018-01-01

    The unprecedented depth and area surveyed by the Subaru Strategic Program with the Hyper Suprime-Cam (HSC-SSP) have enabled us to construct and publish the largest distant cluster sample out to z~1 to date. In this exploratory study of cluster galaxy evolution from z=1 to z=0.3, we investigate the stellar mass assembly history of brightest cluster galaxies (BCGs), and evolution of stellar mass and luminosity distributions, stellar mass surface density profile, as well as the population of radio galaxies. Our analysis is the first high redshift application of the top N richest cluster selection, which is shown to allow us to trace the cluster galaxy evolution faithfully. Our stellar mass is derived from a machine-learning algorithm, which we show to be unbiased and accurate with respect to the COSMOS data. We find very mild stellar mass growth in BCGs, and no evidence for evolution in both the total stellar mass-cluster mass correlation and the shape of the stellar mass surface density profile. The clusters are found to contain more red galaxies compared to the expectations from the field, even after the differences in density between the two environments have been taken into account. We also present the first measurement of the radio luminosity distribution in clusters out to z~1.

  2. Parallel MOPEX: Computing Mosaics of Large-Area Spitzer Surveys on a Cluster Computer

    Directory of Open Access Journals (Sweden)

    Joseph C. Jacob

    2007-01-01

    Full Text Available The Spitzer Science Center's MOPEX software is a part of the Spitzer Space Telescope's operational pipeline that enables detection of cosmic ray collisions with the detector array, masking of the corrupted pixels due to these collisions, subsequent mosaicking of image fields, and extraction of point sources to create catalogs of celestial objects. This paper reports on our experiences in parallelizing the parts of MOPEX related to cosmic ray rejection and mosaicking on a 1,024-processor cluster computer at NASA's Jet Propulsion Laboratory. The architecture and performance of the new Parallel MOPEX software are described. This work was done in order to rapidly mosaic the IRAC shallow survey data, covering a region of the sky observed with one of Spitzer's infrared instruments for the study of galaxy clusters, large-scale structure, and brown dwarfs.

  3. cluster

    Indian Academy of Sciences (India)

    electron transfer chains involved in a number of biologi- cal systems including respiration and photosynthesis.1. The most common iron–sulphur clusters found as active centres in iron–sulphur proteins are [Fe2S2], [Fe3S4] and [Fe4S4], in which Fe(III) ions are coordinated to cysteines from the peptide and are linked to each ...

  4. Chandra Cluster Cosmology Project. II. Samples and X-Ray Data Reduction

    DEFF Research Database (Denmark)

    Vikhlinin, A.; Burenin, R. A.; Ebeling, H.

    2009-01-01

    We discuss the measurements of the galaxy cluster mass functions at z ≈ 0.05 and z ≈ 0.5 using high-quality Chandra observations of samples derived from the ROSAT PSPC All-Sky and 400 deg2 surveys. We provide a full reference for the data analysis procedures, present updated calibration of relati...... at a fixed mass threshold, e.g., by a factor of 5.0 ± 1.2 at M 500 = 2.5 × 1014 h –1 M sun between z = 0 and 0.5. This evolution reflects the growth of density perturbations, and can be used for the cosmological constraints complementing those from the distance-redshift relation....

  5. Structural oxidation state studies of the manganese cluster in the oxygen evolving complex of photosystem II

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Wenchuan [Univ. of California, Berkeley, CA (United States)

    1994-11-01

    X-ray absorption spectroscopy (XAS) was performed on Photosystem II (PSII)-enriched membranes prepared from spinach to explore: (1) the correlation between structure and magnetic spin state of the Mn cluster in the oxygen evolving complex (OEC) in the S2 state; and (2) the oxidation state changes of the Mn cluster in the flash-induced S-states. The structure of the Mn cluster in the S2 state with the g~4 electron paramagnetic resonance (EPR) signal (S2-g4 state) was compared with that in the S2 state with multiline signal (S2-MLS state) and the S1 state. The S2-g4 state has a higher XAS inflection point energy than that of the S1 state, indicating the oxidation of Mn in the advance from the S1 to the S2-g4 state. Differences in the edge shape and in the extended X-ray absorption fine structure (EXAFS) show that the structure of the Mn cluster in the S2-g4 state is different from that in the S2-MLS or the S1 state. In the S2-g4 state, the second shell of backscatterers from the Mn absorber contains two Mn-Mn distances of 2.73 Å and 2.85 Å. Very little distance disorder exists in the second shell of the S1 or S2-MLS states. The third shell of the S2-g4 state at about 3.3 Å also contains increased heterogeneity relative to that of the S2-MLS or the S1 state. Various S-states were prepared at room-temperature by saturating, single-turnover flashes. The flash-dependent oscillation in the amplitude of the MLS was used to characterize the S-state composition and to construct "pure" S-state Mn K-edge spectra. The edge position shifts to higher energy by 1.8 eV upon the S1 → S2 transition.

  6. A Kinematic Survey in the Perseus Molecular Cloud: Results from the APOGEE Infrared Survey of Young Nebulous Clusters (IN-SYNC)

    Science.gov (United States)

    Covey, Kevin R.; Cottaar, M.; Foster, J. B.; Nidever, D. L.; Meyer, M.; Tan, J.; Da Rio, N.; Flaherty, K. M.; Stassun, K.; Frinchaboy, P. M.; Majewski, S.; APOGEE IN-SYNC Team

    2014-01-01

    Demographic studies of stellar clusters indicate that relatively few persist as bound structures for 100 Myrs or longer. If cluster dispersal is a 'violent' process, it could strongly influence the formation and early evolution of stellar binaries and planetary systems. Unfortunately, measuring the dynamical state of 'typical' (i.e., ~300-1000 member) young star clusters has been difficult, particularly for clusters still embedded within their parental molecular cloud. The near-infrared spectrograph for the Apache Point Observatory Galactic Evolution Experiment (APOGEE), which can measure precise radial velocities for 230 cluster stars simultaneously, is uniquely suited to diagnosing the dynamics of Galactic star formation regions. We give an overview of the INfrared Survey of Young Nebulous Clusters (IN-SYNC), an APOGEE ancillary science program that is carrying out a comparative study of young clusters in the Perseus molecular cloud: NGC 1333, a heavily embedded cluster, and IC 348, which has begun to disperse its surrounding molecular gas. These observations appear to rule out a significantly super-virial velocity dispersion in IC 348, contrary to predictions of models where a cluster's dynamics is strongly influenced by the dispersal of its primordial gas. We also summarize the properties of two newly identified spectroscopic binaries; binary systems such as these play a key role in the dynamical evolution of young clusters, and introduce velocity offsets that must be accounted for in measuring cluster velocity dispersions.

  7. Towards high accuracy tests on the substellar IMF in young clusters. A survey in NGC 2024.

    Science.gov (United States)

    Da Rio, Nicola

    2017-08-01

    Measuring the Initial Mass Function in young clusters, and testing its universality, is a fundamental benchmark to constrain the physical processes and theoretical models of star formation. The shape and universality of the stellar IMF are well known. Our observational characterization of the substellar IMF, on the other hand, remains more uncertain, along with its possible environmental variations. Because of this, the physical processes that play a role in the formation of brown dwarfs are not fully constrained. In Cycle 22 we were awarded HST time to carry out the deepest spectro-photometric census of BDs in a young cluster: the Orion Nebula Cluster. Through deep WFC3/IR narrow band imaging, we are able to obtain Teff and A_V down to 15Mjup. Preliminary analysis limited to a portion of the total field of view allows us to classify several hundreds BDs, place them in the HRD and obtain, for an extinction limited sample, the complete and consistent IMF down to planetary masses. The substellar slope is consistent with the Galactic IMF but a rapid drop is found at the H-burning limit. We propose to carry out a nearly identical survey with HST in a younger, less massive nearby cluster: NGC2024 in the Flame Nebula. This will allow us to derive the complete census of the young population down to planetary masses, derive the IMF, enabling a consistent comparison with the results in the ONC. We will specifically look for statistically significant IMF variations with environmental properties (cluster mass, density) and investigate primordial mass segregation in the substellar regime. These results will significantly help to constrain the mechanisms involved in BD formation.

  8. Next Generation Virgo Cluster Survey. XXI. The Weak Lensing Masses of the CFHTLS and NGVS RedGOLD Galaxy Clusters and Calibration of the Optical Richness

    Science.gov (United States)

    Parroni, Carolina; Mei, Simona; Erben, Thomas; Van Waerbeke, Ludovic; Raichoor, Anand; Ford, Jes; Licitra, Rossella; Meneghetti, Massimo; Hildebrandt, Hendrik; Miller, Lance; Côté, Patrick; Covone, Giovanni; Cuillandre, Jean-Charles; Duc, Pierre-Alain; Ferrarese, Laura; Gwyn, Stephen D. J.; Puzia, Thomas H.

    2017-10-01

    We measured stacked weak lensing cluster masses for a sample of 1323 galaxy clusters detected by the RedGOLD algorithm in the Canada-France-Hawaii Telescope Legacy Survey W1 and the Next Generation Virgo Cluster Survey at 0.2z< 0.5, in the optical richness range 10< λ < 70. This is the most comprehensive lensing study of a ˜ 100 % complete and ˜ 80 % pure optical cluster catalog in this redshift range. We test different mass models, and our final model includes a basic halo model with a Navarro Frenk and White profile, as well as correction terms that take into account cluster miscentering, non-weak shear, the two-halo term, the contribution of the Brightest Cluster Galaxy, and an a posteriori correction for the intrinsic scatter in the mass-richness relation. With this model, we obtain a mass-richness relation of {log}{M}200/{M}⊙ =(14.46+/- 0.02)+(1.04+/- 0.09){log}(λ /40) (statistical uncertainties). This result is consistent with other published lensing mass-richness relations. We give the coefficients of the scaling relations between the lensing mass and X-ray mass proxies, L X and T X, and compare them with previous results. When compared to X-ray masses and mass proxies, our results are in agreement with most previous results and simulations, and consistent with the expected deviations from self-similarity.

  9. Rotational fluctuation of molecules in quantum clusters. II. Molecular rotation and superfluidity in OCS-doped helium-4 clusters.

    Science.gov (United States)

    Miura, Shinichi

    2007-03-21

    In this paper, quantum fluctuations of a carbonyl sulfide molecule in helium-4 clusters are studied as a function of cluster size N in a small-to-large size regime (2or=20, which is larger than the experimental nanodroplet value. Superfluid response of the doped cluster is found to show remarkable anisotropy especially for Nfluctuation of the molecule. On the other hand, the superfluid fraction regarding the axis parallel to the molecular axis reaches 0.9 at N=5, arising from the bosonic exchange cycles of the helium atoms around the molecular axis. The anisotropy in the superfluid response is found to be the direct consequence of the configurations of the bosonic exchange cycles.

  10. The use of oxygen in cluster headache treatment worldwide - a survey of the International Headache Society (IHS).

    Science.gov (United States)

    Evers, Stefan; Rapoport, Alan

    2017-04-01

    Background Oxygen is recommended for the treatment of acute cluster headache attacks. However, it is not available worldwide. Methods The International Headache Society performed a survey among its national member societies on the availability and the restrictions for oxygen in the treatment of cluster headache. Results Oxygen is reimbursed in 50% of all countries responding ( n = 22). There are additional restrictions in the reimbursement of the facial mask and with respect to age. Conclusion Oxygen for the treatment of cluster headache attack is not reimbursed worldwide. Headache societies should pressure national/public health authorities to reimburse oxygen for cluster headache in all countries.

  11. The KMOS Cluster Survey (KCS). III. Fundamental Plane of Cluster Galaxies at z ≃ 1.80 in JKCS 041

    Science.gov (United States)

    Prichard, Laura J.; Davies, Roger L.; Beifiori, Alessandra; Chan, Jeffrey C. C.; Cappellari, Michele; Houghton, Ryan C. W.; Mendel, J. Trevor; Bender, Ralf; Galametz, Audrey; Saglia, Roberto P.; Stott, John P.; Wilman, David J.; Lewis, Ian J.; Sharples, Ray; Wegner, Michael

    2017-12-01

    We present data for 16 galaxies in the overdensity JKCS 041 at z≃ 1.80 as part of the K-band Multi-Object Spectrograph (KMOS) Cluster Survey (KCS). With 20 hr integrations, we have obtained deep absorption-line spectra from which we derived velocity dispersions for seven quiescent galaxies. We combined photometric parameters derived from Hubble Space Telescope images with the dispersions to construct a fundamental plane (FP) for quiescent galaxies in JKCS 041. From the zero-point evolution of the FP, we derived a formation redshift for the galaxies of {z}{form}=3.0+/- 0.3, corresponding to a mean age of 1.4 ± 0.2 Gyr. We tested the effect of structural and velocity dispersion evolution on our FP zero-point and found a negligible contribution when using dynamical mass-normalized parameters (˜ 3 % ) but a significant contribution from stellar-mass-normalized parameters (˜ 42 % ). From the relative velocities of the galaxies, we probed the 3D structure of these 16 confirmed members of JKCS 041 and found that a group of galaxies in the southwest of the overdensity had systematically higher velocities. We derived ages for the galaxies in the different groups from the FP. We found that the east-extending group had typically older galaxies ({2.1}-0.2+0.3 Gyr) than those in the southwest group (0.3 ± 0.2 Gyr). Although based on small numbers, the overdensity dynamics, morphology, and age results could indicate that JKCS 041 is in formation and may comprise two merging groups of galaxies. This result could link large-scale structure to ages of galaxies for the first time at this redshift. Based on observations obtained at the Very Large Telescope (VLT) of the European Southern Observatory (ESO), Paranal, Chile (ESO program IDs: 095.A-0137(A) and 096.A-0189(A)).

  12. On Identifying Clusters Within the C-type Asteroids of the Sloan Digital Sky Survey

    Science.gov (United States)

    Poole, Renae; Ziffer, J.; Harvell, T.

    2012-10-01

    We applied AutoClass, a data mining technique based upon Bayesian Classification, to C-group asteroid colors in the Sloan Digital Sky Survey (SDSS). Previous taxonomic studies relied mostly on Principal Component Analysis (PCA) to differentiate asteroids within the C-group (e.g. B, G, F, Ch, Cg and Cb). AutoClass's advantage is that it calculates the most probable classification for us, removing the human factor from this part of the analysis. In our results, AutoClass divided the C-groups into two large classes and six smaller classes. The two large classes (n=4974 and 2033, respectively) display distinct regions with some overlap in color-vs-color plots. Each cluster's average spectrum is compared to 'typical' spectra of the C-group subtypes as defined by Tholen (1989) and each cluster's members are evaluated for consistency with previous taxonomies. Of the 117 asteroids classified as B-type in previous taxonomies, only 12 were found with SDSS colors that matched our criteria of having less than 0.1 magnitude error in u and 0.05 magnitude error in g, r, i, and z colors. Although this is a relatively small group, 11 of the 12 B-types were placed by AutoClass in the same cluster. By determining the C-group sub-classifications in the large SDSS database, this research furthers our understanding of the stratigraphy and composition of the main-belt.

  13. National Youth Survey US: Wave II (NYS-1977)

    Data.gov (United States)

    U.S. Department of Health & Human Services — Youth data for the second wave of the National Youth Survey are contained in this data collection. The first wave was conducted in 1976. Youths were interviewed in...

  14. Born-Oppenheimer molecular dynamics studies of Pb(ii) micro hydrated gas phase clusters

    Science.gov (United States)

    León-Pimentel, C. I.; Amaro-Estrada, J. I.; Saint-Martin, H.; Ramírez-Solís, A.

    2017-02-01

    In this work, a theoretical investigation was made to assess the coordination properties of Pb(ii) in [Pb(H2O)n]2+ clusters, with n = 4, 6, 8, 12, and 29, as well as to study proton transfer events, by means of Born-Oppenheimer molecular dynamics simulations at the B3LYP/aug-cc-pVDZ-pp/6-311G level of theory, that were calibrated in comparison with B3LYP/aug-cc-pVDZ-PP/aug-cc-pVDZ calculations. Hemidirected configurations were found in all cases; the radial distribution functions (RDFs) produced well defined first hydration shells (FHSs) for n = 4,6,8, and 12, that resulted in a coordination number CN = 4, whereas a clear-cut FHS was not found for n = 29 because the RDF did not have a vacant region after the first maximum; however, three water molecules remained directly interacting with the Pb ion for the whole simulation, while six others stayed at average distances shorter than 4 Å but dynamically getting closer and farther, thus producing a CN ranging from 6 to 9, depending on the criterion used to define the first hydration shell. In agreement with experimental data and previous calculations, proton transfer events were observed for n ≤8 but not for n ≥12 . For an event to occur, a water molecule in the second hydration shell had to make a single hydrogen bond with a water molecule in the first hydration shell.

  15. THE NEXT GENERATION VIRGO CLUSTER SURVEY. XIX. TOMOGRAPHY OF MILKY WAY SUBSTRUCTURES IN THE NGVS FOOTPRINT

    Energy Technology Data Exchange (ETDEWEB)

    Lokhorst, Deborah; Starkenburg, Else; Navarro, Julio F. [Department of Physics and Astronomy, University of Victoria, Victoria, BC V8P 1A1, Canada (Canada); McConnachie, Alan W.; Ferrarese, Laura; Côté, Patrick; Gwyn, Stephen D. J. [National Research Council, Herzberg Astronomy and Astrophysics, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Liu, Chengze [Center for Astronomy and Astrophysics, Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Peng, Eric W. [Department of Astronomy, Peking University, Beijing 100871 (China); Cuillandre, Jean-Charles [CEA/IRFU/SAP, Laboratoire AIM Paris-Saclay, CNRS/INSU, Université Paris Diderot, Observatoire de Paris, PSL Research University, F-91191 Gif-sur-Yvette Cedex (France); Guhathakurta, Puragra, E-mail: dml@uvic.ca [Department of Astronomy and Astrophysics, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States)

    2016-03-10

    The Next Generation Virgo Cluster Survey (NGVS) is a deep u*giz survey targeting the Virgo Cluster of galaxies at 16.5 Mpc. This survey provides high-quality photometry over an ∼100 deg{sup 2} region straddling the constellations of Virgo and Coma Berenices. This sightline through the Milky Way is noteworthy in that it intersects two of the most prominent substructures in the Galactic halo: the Virgo overdensity (VOD) and Sagittarius stellar stream (close to its bifurcation point). In this paper, we use deep u*gi imaging from the NGVS to perform tomography of the VOD and Sagittarius stream using main-sequence turnoff (MSTO) stars as a halo tracer population. The VOD, whose centroid is known to lie at somewhat lower declinations (α ∼ 190°, δ ∼ −5°) than is covered by the NGVS, is nevertheless clearly detected in the NGVS footprint at distances between ∼8 and 25 kpc. By contrast, the Sagittarius stream is found to slice directly across the NGVS field at distances between 25 and 40 kpc, with a density maximum at ≃35 kpc. No evidence is found for new substructures beyond the Sagittarius stream, at least out to a distance of ∼90 kpc—the largest distance to which we can reliably trace the halo using MSTO stars. We find clear evidence for a distance gradient in the Sagittarius stream across the ∼30° of sky covered by the NGVS and its flanking fields. We compare our distance measurements along the stream with those predicted by leading stream models.

  16. THE NEXT GENERATION VIRGO CLUSTER SURVEY. XV. THE PHOTOMETRIC REDSHIFT ESTIMATION FOR BACKGROUND SOURCES

    Energy Technology Data Exchange (ETDEWEB)

    Raichoor, A.; Mei, S.; Huertas-Company, M.; Licitra, R. [GEPI, Observatoire de Paris, CNRS, Université Paris Diderot, 61 Avenue de l' Observatoire, F-75014 Paris (France); Erben, T.; Hildebrandt, H. [Argelander-Institut für Astronomie, University of Bonn, Auf dem Hügel 71, D-53121 Bonn (Germany); Ilbert, O.; Boissier, S.; Boselli, A. [Aix Marseille Université, CNRS, Laboratoire d' Astrophysique de Marseille, UMR 7326, F-13388 Marseille (France); Ball, N. M.; Côté, P.; Ferrarese, L.; Gwyn, S. D. J.; Kavelaars, J. J. [Herzberg Institute of Astrophysics, National Research Council of Canada, Victoria, BC V9E 2E7 (Canada); Chen, Y.-T. [Insitute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 106, Taiwan (China); Cuillandre, J.-C. [Canada-France-Hawaïi Telescope Corporation, Kamuela, HI 96743 (United States); Duc, P. A. [Laboratoire AIM Paris-Saclay, CEA/IRFU/SAp, CNRS/INSU, Université Paris Diderot, F-91191 Gif-sur-Yvette Cedex (France); Durrell, P. R. [Department of Physics and Astronomy, Youngstown State University, Youngstown, OH 44555 (United States); Guhathakurta, P. [UCO/Lick Observatory, Department of Astronomy and Astrophysics, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States); Lançon, A., E-mail: anand.raichoor@obspm.fr [Observatoire Astronomique de Strasbourg, Université de Strasbourg, CNRS, UMR 7550, 11 rue de l' Université, F-67000 Strasbourg (France); and others

    2014-12-20

    The Next Generation Virgo Cluster Survey (NGVS) is an optical imaging survey covering 104 deg{sup 2} centered on the Virgo cluster. Currently, the complete survey area has been observed in the u*giz bands and one third in the r band. We present the photometric redshift estimation for the NGVS background sources. After a dedicated data reduction, we perform accurate photometry, with special attention to precise color measurements through point-spread function homogenization. We then estimate the photometric redshifts with the Le Phare and BPZ codes. We add a new prior that extends to i {sub AB} = 12.5 mag. When using the u* griz bands, our photometric redshifts for 15.5 mag ≤ i ≲ 23 mag or z {sub phot} ≲ 1 galaxies have a bias |Δz| < 0.02, less than 5% outliers, a scatter σ{sub outl.rej.}, and an individual error on z {sub phot} that increases with magnitude (from 0.02 to 0.05 and from 0.03 to 0.10, respectively). When using the u*giz bands over the same magnitude and redshift range, the lack of the r band increases the uncertainties in the 0.3 ≲ z {sub phot} ≲ 0.8 range (–0.05 < Δz < –0.02, σ{sub outl.rej} ∼ 0.06, 10%-15% outliers, and z {sub phot.err.} ∼ 0.15). We also present a joint analysis of the photometric redshift accuracy as a function of redshift and magnitude. We assess the quality of our photometric redshifts by comparison to spectroscopic samples and by verifying that the angular auto- and cross-correlation function w(θ) of the entire NGVS photometric redshift sample across redshift bins is in agreement with the expectations.

  17. A representative survey of the dynamics and energetics of FR II radio galaxies

    Science.gov (United States)

    Ineson, J.; Croston, J. H.; Hardcastle, M. J.; Mingo, B.

    2017-05-01

    We report the first large, systematic study of the dynamics and energetics of a representative sample of Fanaroff-Riley type II (FR II) radio galaxies with well-characterized group/cluster environments. We used X-ray inverse-Compton and radio synchrotron measurements to determine the internal radio-lobe conditions, and these were compared with external pressures acting on the lobes, determined from measurements of the thermal X-ray emission of the group/cluster. Consistent with previous work, we found that FR II radio lobes are typically electron dominated by a small factor relative to equipartition, and are overpressured relative to the external medium in their outer parts. These results suggest that there is typically no energetically significant proton population in the lobes of FR II radio galaxies (unlike for FR Is), and so for this population, inverse-Compton modelling provides an accurate way of measuring total energy content and estimating jet power. We estimated the distribution of Mach numbers for the population of expanding radio lobes, finding that at least half of the radio galaxies are currently driving strong shocks into their group/cluster environments. Finally, we determined a jet power-radio luminosity relation for FR II radio galaxies based on our estimates of lobe internal energy and Mach number. The slope and normalization of this relation are consistent with theoretical expectations, given the departure from equipartition and environmental distribution for our sample.

  18. The Faint Sky Variability Survey II: Initial Results

    OpenAIRE

    Everett, M. E.; Huber, M.E.; Howell, S. B.

    2000-01-01

    We discuss the first results from the Faint Sky Variability Survey (Groot et al. 2000). The data consist of V-band light curves, BVI colours, astrometry, and morphology information on several hundred thousand point and extended sources in the magnitude range V=17-25. We discuss the first 30 survey fields covering an area of 8.4 square degrees towards moderate and high galactic latitudes. We analyse the quality of and discuss our differential photometry light curves. We employ statistical meth...

  19. VizieR Online Data Catalog: Wide-field spectrosc. survey of GCs in Virgo cluster (Ko+, 2017)

    Science.gov (United States)

    Ko, Y.; Hwang, H. S.; Lee, M. G.; Park, H. S.; Lim, S.; Sohn, J.; Jang, I. S.; Hwang, N.; Park, B.-G.

    2017-08-01

    We selected globular cluster (GC) candidates using the Next Generation Virgo Cluster Survey (NGVS; Ferrarese+ 2012ApJS..200....4F) archival images covering the central region of the Virgo cluster. The NGVS is a wide-field imaging survey of the Virgo cluster using MegaCam with a field of view of 1°x1° attached at the Canada-French-Hawaii Telescope. We carried out spectroscopic observation of GC candidates in the Virgo using the Hectospec mounted on the 6.5m Multiple-Mirror Telescope in queue mode under program ID 2014A-UAO-G18 (PI: Myung Gyoon Lee) between 2014 February and March (wavelength range: 3650Å to 9200Å). (3 data files).

  20. Radial velocities and metallicities from infrared Ca ii triplet spectroscopy of open clusters. II. Berkeley 23, King 1, NGC 559, NGC 6603, and NGC 7245

    Science.gov (United States)

    Carrera, R.; Casamiquela, L.; Ospina, N.; Balaguer-Núñez, L.; Jordi, C.; Monteagudo, L.

    2015-06-01

    Context. Open clusters are key to studying the formation and evolution of the Galactic disc. However, there is a deficiency of radial velocity and chemical abundance determinations for open clusters in the literature. Aims: We intend to increase the number of determinations of radial velocities and metallicities from spectroscopy for open clusters. Methods: We acquired medium-resolution spectra (R ~ 8000) in the infrared region Ca ii triplet lines (~8500 Å) for several stars in five open clusters with the long-slit IDS spectrograph on the 2.5 m Isaac Newton Telescope (Roque de los Muchachos Observatory, Spain). Radial velocities were obtained by cross-correlation fitting techniques. The relationships available in the literature between the strength of infrared Ca ii lines and metallicity were also used to derive the metallicity for each cluster. Results: We obtain ⟨Vr⟩ = 48.6 ± 3.4, -58.4 ± 6.8, 26.0 ± 4.3, and -65.3 ± 3.2 km s-1 for Berkeley 23, NGC 559, NGC 6603, and NGC 7245, respectively. We found [ Fe/H ] = -0.25 ± 0.14 and -0.15 ± 0.18 for NGC 559 and NGC 7245, respectively. Berkeley 23 has low metallicity, [ Fe/H ] = -0.42 ± 0.13, which is similar to other open clusters in the outskirts of the Galactic disc. In contrast, we derived high metallicity ([ Fe/H ] = +0.43 ± 0.15) for NGC 6603, which places this system among the most metal-rich known open clusters. To our knowledge, this is the first determination of radial velocities and metallicities from spectroscopy for these clusters, except NGC 6603, for which radial velocities had been previously determined. We have also analysed ten stars in the line of sight to King 1. Because of the large dispersion obtained in both radial velocity and metallicity, we cannot be sure that we have sampled true cluster members. Based on observations made with the 2.5 m Isaac Newton Telescope operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the

  1. CANDIDATE CLUSTERS OF GALAXIES AT z > 1.3 IDENTIFIED IN THE SPITZER SOUTH POLE TELESCOPE DEEP FIELD SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Rettura, A.; Stern, D. [Jet Propulsion Laboratory, California Institute of Technology, MS 169-234, Pasadena, CA 91109 (United States); Martinez-Manso, J.; Gettings, D.; Gonzalez, A. H. [Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States); Mei, S. [GEPI, Observatoire de Paris, Section de Meudon, Meudon Cedex (France); Ashby, M. L. N. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Brodwin, M. [Department of Physics and Astronomy, University of Missouri, Kansas City, MO 64110 (United States); Stanford, S. A. [Department of Physics, University of California, Davis, CA 95616 (United States); Bartlett, J. G. [APC, AstroParticule et Cosmologie, Universite Paris Diderot, CNRS/IN2P3, CEA/lrfu, Observatoire de Paris, Sorbonne Paris Cite, 75205 Paris Cedex 13 (France)

    2014-12-20

    We present 279 galaxy cluster candidates at z > 1.3 selected from the 94 deg{sup 2} Spitzer South Pole Telescope Deep Field (SSDF) survey. We use a simple algorithm to select candidate high-redshift clusters of galaxies based on Spitzer/IRAC mid-infrared data combined with shallow all-sky optical data. We identify distant cluster candidates adopting an overdensity threshold that results in a high purity (80%) cluster sample based on tests in the Spitzer Deep, Wide-Field Survey of the Boötes field. Our simple algorithm detects all three 1.4 < z ≤ 1.75 X-ray detected clusters in the Boötes field. The uniqueness of the SSDF survey resides not just in its area, one of the largest contiguous extragalactic fields observed with Spitzer, but also in its deep, multi-wavelength coverage by the South Pole Telescope (SPT), Herschel/SPIRE, and XMM-Newton. This rich data set will allow direct or stacked measurements of Sunyaev-Zel'dovich effect decrements or X-ray masses for many of the SSDF clusters presented here, and enable a systematic study of the most distant clusters on an unprecedented scale. We measure the angular correlation function of our sample and find that these candidates show strong clustering. Employing the COSMOS/UltraVista photometric catalog in order to infer the redshift distribution of our cluster selection, we find that these clusters have a comoving number density n{sub c}=(0.7{sub −0.6}{sup +6.3})×10{sup −7} h{sup 3} Mpc{sup −3} and a spatial clustering correlation scale length r {sub 0} = (32 ± 7) h {sup –1} Mpc. Assuming our sample is comprised of dark matter halos above a characteristic minimum mass, M {sub min}, we derive that at z = 1.5 these clusters reside in halos larger than M{sub min}=1.5{sub −0.7}{sup +0.9}×10{sup 14} h{sup −1} M{sub ⊙}. We find that the mean mass of our cluster sample is equal to M{sub mean}=1.9{sub −0.8}{sup +1.0}×10{sup 14} h{sup −1} M{sub ⊙}; thus, our sample contains the progenitors of

  2. The MUSIC of galaxy clusters - II. X-ray global properties and scaling relations

    Science.gov (United States)

    Biffi, V.; Sembolini, F.; De Petris, M.; Valdarnini, R.; Yepes, G.; Gottlöber, S.

    2014-03-01

    We present the X-ray properties and scaling relations of a large sample of clusters extracted from the Marenostrum MUltidark SImulations of galaxy Clusters (MUSIC) data set. We focus on a sub-sample of 179 clusters at redshift z ˜ 0.11, with 3.2 × 1014 h-1 M⊙ MUSIC clusters reasonably resemble the self-similar prediction, especially for correlations involving TX. The observational approach also allows for a more direct comparison with real clusters, from which we find deviations mainly due to the physical description of the ICM, affecting TX and, particularly, LX.

  3. Optical Follow-Up Observations for the High-z COBRA (Clusters Occupied by Bent Radio AGN) Survey

    Science.gov (United States)

    Golden-Marx, Emmet; Blanton, Elizabeth L.; Paterno-Mahler, Rachel; Wing, Joshua; Ashby, Matthew; Brodwin, Mark

    2015-01-01

    Galaxy clusters are unique laboratories for exploring galaxy formation and evolution. Relatively few galaxy clusters have been spectroscopically confirmed beyond a redshift of 1. Different methods of searching for galaxy clusters are adding to these numbers, including detecting regions with a high-density of galaxies in the optical and IR regimes, detecting the hot intracluster medium in the X-ray, and measuring the Sunyaev-Zel'dovich effect. Another promising method for discovering high-redshift galaxy clusters uses radio observations of AGN. In particular, we use bent-double lobed radio sources, known often to reside in nearby clusters, as markers for distant galaxy clusters. We present initial results from the high-redshift COBRA (Clusters Occupied by Bent Radio AGN) survey. We have Spitzer IRAC observations of 653 bent-double radio sources with hosts too faint to be detected in the SDSS. Since the host galaxies for these radio sources are usually giant ellipticals, lack of detection in the SDSS means they are likely at z > 0.7. We have begun deep follow-up optical observations using the 4.3 m Discovery Channel Telescope and have determined from these initial optical observations that ~50% of the observed fields are overdense and thus good cluster candidates. Additionally, we have created optical-IR color magnitude diagrams to estimate the redshifts of our cluster candidates by identifying the red sequence. The distribution of galaxies on the red sequence can be used to limit galaxy formation models.

  4. A Survey of Open Clusters in the u'g'r'i'z' Filter System. 3. Results for the Cluster NGC 188

    Energy Technology Data Exchange (ETDEWEB)

    Fornal, Bartosz; Tucker, Douglas L.; Smith, J.Allyn; Allam, Sahar S.; Rider, Cristin J.; Sung, Hwankyung; /Jagiellonian U. /Fermilab /Austin Peay State U. /Wyoming U. /Johns Hopkins U. /Sejong U.

    2006-11-01

    The authors continue the series of papers describing the results of a photometric survey of open star clusters, primarily in the southern hemisphere, taken in the u'g'r'i'z' filter system. The entire observed sample covered more than 100 clusters, but here they present data only on NGC 188, which is one of the oldest open clusters known in the Milky Way. They fit the Padova theoretical isochrones to the data. Assuming a solar metallicity for NGC 188, they find a distance of 1700 {+-} 100 pc, an age of 7.5 {+-} 0.7 Gyr, and a reddening E(B-V) of 0.025 {+-} 0.005. This yields a distance modulus of 11.23 {+-} 0.14.

  5. MASSIVE+: The Growth Histories of MASSIVE Survey Galaxies from their Globular Cluster Colors

    Science.gov (United States)

    Blakeslee, John

    2017-08-01

    The MASSIVE survey is targeting the 100 most massive galaxies within 108 Mpc that are visible in the northern sky. These most massive galaxies in the present-day universe reside in a surprisingly wide variety of environments, from rich clusters to fossil groups to near isolation. We propose to use WFC3/UVIS and ACS to carry out a deep imaging study of the globular cluster populations around a selected subset of the MASSIVE targets. Though much is known about GC systems of bright galaxies in rich clusters, we know surprisingly little about the effects of environment on these systems. The MASSIVE sample provides a golden opportunity to learn about the systematics of GC systems and what they can tell us about environmental drivers on the evolution of the highest mass galaxies. The most pressing questions to be addressed include: (1) Do isolated giants have the same constant mass fraction of GCs to total halo mass as BCGs of similar luminosity? (2) Do their GC systems show the same color (metallicity) distribution, which is an outcome of the mass spectrum of gas-rich halos during hierarchical growth? (3) Do the GCs in isolated high-mass galaxies follow the same radial distribution versus metallicity as in rich environments (a test of the relative importance of growth by accretion)? (4) Do the GCs of galaxies in sparse environments follow the same mass function? Our proposed second-band imaging will enable us to secure answers to these questions and add enormously to the legacy value of existing HST imaging of the highest mass galaxies in the universe.

  6. New Survey Questions and Estimators for Network Clustering with Respondent-Driven Sampling Data

    CERN Document Server

    Verdery, Ashton M; Siripong, Nalyn; Abdesselam, Kahina; Bauldry, Shawn

    2016-01-01

    Respondent-driven sampling (RDS) is a popular method for sampling hard-to-survey populations that leverages social network connections through peer recruitment. While RDS is most frequently applied to estimate the prevalence of infections and risk behaviors of interest to public health, like HIV/AIDS or condom use, it is rarely used to draw inferences about the structural properties of social networks among such populations because it does not typically collect the necessary data. Drawing on recent advances in computer science, we introduce a set of data collection instruments and RDS estimators for network clustering, an important topological property that has been linked to a network's potential for diffusion of information, disease, and health behaviors. We use simulations to explore how these estimators, originally developed for random walk samples of computer networks, perform when applied to RDS samples with characteristics encountered in realistic field settings that depart from random walks. In partic...

  7. Cluster Mass Calibration at High Redshift: HST Weak Lensing Analysis of 13 Distant Galaxy Clusters from the South Pole Telescope Sunyaev-Zel'dovich Survey

    Energy Technology Data Exchange (ETDEWEB)

    Schrabback, T.; et al.

    2016-11-11

    We present an HST/ACS weak gravitational lensing analysis of 13 massive high-redshift (z_median=0.88) galaxy clusters discovered in the South Pole Telescope (SPT) Sunyaev-Zel'dovich Survey. This study is part of a larger campaign that aims to robustly calibrate mass-observable scaling relations over a wide range in redshift to enable improved cosmological constraints from the SPT cluster sample. We introduce new strategies to ensure that systematics in the lensing analysis do not degrade constraints on cluster scaling relations significantly. First, we efficiently remove cluster members from the source sample by selecting very blue galaxies in V-I colour. Our estimate of the source redshift distribution is based on CANDELS data, where we carefully mimic the source selection criteria of the cluster fields. We apply a statistical correction for systematic photometric redshift errors as derived from Hubble Ultra Deep Field data and verified through spatial cross-correlations. We account for the impact of lensing magnification on the source redshift distribution, finding that this is particularly relevant for shallower surveys. Finally, we account for biases in the mass modelling caused by miscentring and uncertainties in the mass-concentration relation using simulations. In combination with temperature estimates from Chandra we constrain the normalisation of the mass-temperature scaling relation ln(E(z) M_500c/10^14 M_sun)=A+1.5 ln(kT/7.2keV) to A=1.81^{+0.24}_{-0.14}(stat.) +/- 0.09(sys.), consistent with self-similar redshift evolution when compared to lower redshift samples. Additionally, the lensing data constrain the average concentration of the clusters to c_200c=5.6^{+3.7}_{-1.8}.

  8. VizieR Online Data Catalog: SPT-SZ survey galaxy clusters optical spectroscopy (Ruel+, 2014)

    Science.gov (United States)

    Ruel, J.; Bazin, G.; Bayliss, M.; Brodwin, M.; Foley, R. J.; Stalder, B.; Aird, K. A.; Armstrong, R.; Ashby, M. L. N.; Bautz, M.; Benson, B. A.; Bleem, L. E.; Bocquet, S.; Carlstrom, J. E.; Chang, C. L.; Chapman, S. C.; Cho, H. M.; Clocchiatti, A.; Crawford, T. M.; Crites, A. T.; de Haan, T.; Desai, S.; Dobbs, M. A.; Dudley, J. P.; Forman, W. R.; George, E. M.; Gladders, M. D.; Gonzalez, A. H.; Halverson, N. W.; Harrington, N. L.; High, F. W.; Holder, G. P.; Holzapfel, W. L.; Hrubes, J. D.; Jones, C.; Joy, M.; Keisler, R.; Knox, L.; Lee, A. T.; Leitch, E. M.; Liu, J.; Lueker, M.; Luong-van, D.; Mantz, A.; Marrone, D. P.; McDonald, M.; McMahon, J. J.; Mehl, J.; Meyer, S. S.; Mocanu, L.; Mohr, J. J.; Montroy, T. E.; Murray, S. S.; Natoli, T.; Nurgaliev, D.; Padin, S.; Plagge, T.; Pryke, C.; Reichardt, C. L.; Rest, A.; Ruhl, J. E.; Saliwanchik, B. R.; Saro, A.; Sayre, J. T.; Schaffer, K. K.; Shaw, L.; Shirokoff, E.; Song, J.; Suhada, R.; Spieler, H. G.; Stanford, S. A.; Staniszewski, Z.; Starsk, A. A.; Story, K.; Stubbs, C. W.; van Engelen, A.; Vanderlinde, K.; Vieira, J. D.; Vikhlinin, A.; Williamson, R.; Zahn, O.; Zenteno, A.

    2017-04-01

    Most of the galaxy clusters for which we report spectroscopic observations were published as SPT cluster detections (and new discoveries) in Vanderlinde et al. (2010ApJ...722.1180V), Williamson et al. (2011ApJ...738..139W), and Reichardt et al. (2013, J/ApJ/763/127); we refer the reader to those publications for details of the SPT observations. The spectroscopic observations presented in this work are the first of our ongoing follow-up program. The data were taken from 2008 to 2012 using the Gemini Multi Object Spectrograph (GMOS; Hook et al. 2004PASP..116..425H) on Gemini South, the Focal Reducer and low dispersion Spectrograph (FORS2; Appenzeller et al. 1998Msngr..94....1A) on VLT Antu, the Inamori Magellan Areal Camera and Spectrograph (IMACS; Dressler et al. 2006SPIE.6269E..0FD) on Magellan Baade, and the Low Dispersion Survey Spectrograph (LDSS339; Allington-Smith et al. 1994PASP..106..983A) on Magellan Clay. (3 data files).

  9. Dengue fever occurrence and vector detection by larval survey, ovitrap and MosquiTRAP: a space-time clusters analysis.

    Science.gov (United States)

    de Melo, Diogo Portella Ornelas; Scherrer, Luciano Rios; Eiras, Álvaro Eduardo

    2012-01-01

    The use of vector surveillance tools for preventing dengue disease requires fine assessment of risk, in order to improve vector control activities. Nevertheless, the thresholds between vector detection and dengue fever occurrence are currently not well established. In Belo Horizonte (Minas Gerais, Brazil), dengue has been endemic for several years. From January 2007 to June 2008, the dengue vector Aedes (Stegomyia) aegypti was monitored by ovitrap, the sticky-trap MosquiTRAP™ and larval surveys in an study area in Belo Horizonte. Using a space-time scan for clusters detection implemented in SaTScan software, the vector presence recorded by the different monitoring methods was evaluated. Clusters of vectors and dengue fever were detected. It was verified that ovitrap and MosquiTRAP vector detection methods predicted dengue occurrence better than larval survey, both spatially and temporally. MosquiTRAP and ovitrap presented similar results of space-time intersections to dengue fever clusters. Nevertheless ovitrap clusters presented longer duration periods than MosquiTRAP ones, less acuratelly signalizing the dengue risk areas, since the detection of vector clusters during most of the study period was not necessarily correlated to dengue fever occurrence. It was verified that ovitrap clusters occurred more than 200 days (values ranged from 97.0±35.35 to 283.0±168.4 days) before dengue fever clusters, whereas MosquiTRAP clusters preceded dengue fever clusters by approximately 80 days (values ranged from 65.5±58.7 to 94.0±14. 3 days), the former showing to be more temporally precise. Thus, in the present cluster analysis study MosquiTRAP presented superior results for signaling dengue transmission risks both geographically and temporally. Since early detection is crucial for planning and deploying effective preventions, MosquiTRAP showed to be a reliable tool and this method provides groundwork for the development of even more precise tools.

  10. Dengue Fever Occurrence and Vector Detection by Larval Survey, Ovitrap and MosquiTRAP: A Space-Time Clusters Analysis

    Science.gov (United States)

    de Melo, Diogo Portella Ornelas; Scherrer, Luciano Rios; Eiras, Álvaro Eduardo

    2012-01-01

    The use of vector surveillance tools for preventing dengue disease requires fine assessment of risk, in order to improve vector control activities. Nevertheless, the thresholds between vector detection and dengue fever occurrence are currently not well established. In Belo Horizonte (Minas Gerais, Brazil), dengue has been endemic for several years. From January 2007 to June 2008, the dengue vector Aedes (Stegomyia) aegypti was monitored by ovitrap, the sticky-trap MosquiTRAP™ and larval surveys in an study area in Belo Horizonte. Using a space-time scan for clusters detection implemented in SaTScan software, the vector presence recorded by the different monitoring methods was evaluated. Clusters of vectors and dengue fever were detected. It was verified that ovitrap and MosquiTRAP vector detection methods predicted dengue occurrence better than larval survey, both spatially and temporally. MosquiTRAP and ovitrap presented similar results of space-time intersections to dengue fever clusters. Nevertheless ovitrap clusters presented longer duration periods than MosquiTRAP ones, less acuratelly signalizing the dengue risk areas, since the detection of vector clusters during most of the study period was not necessarily correlated to dengue fever occurrence. It was verified that ovitrap clusters occurred more than 200 days (values ranged from 97.0±35.35 to 283.0±168.4 days) before dengue fever clusters, whereas MosquiTRAP clusters preceded dengue fever clusters by approximately 80 days (values ranged from 65.5±58.7 to 94.0±14. 3 days), the former showing to be more temporally precise. Thus, in the present cluster analysis study MosquiTRAP presented superior results for signaling dengue transmission risks both geographically and temporally. Since early detection is crucial for planning and deploying effective preventions, MosquiTRAP showed to be a reliable tool and this method provides groundwork for the development of even more precise tools. PMID:22848729

  11. A NEW Hα EMISSION-LINE SURVEY IN THE ORION NEBULA CLUSTER

    Energy Technology Data Exchange (ETDEWEB)

    Szegedi-Elek, E.; Kun, M.; Pál, A.; Balázs, L. G. [Konkoly Observatory, H-1121 Budapest, Konkoly Thege út 15-17 (Hungary); Reipurth, B.; Willman, M., E-mail: eelza@konkoly.hu [Institute for Astronomy, University of Hawaii at Manoa, 640 N. Aohoku Place, Hilo, HI 96720 (United States)

    2013-10-01

    We present results from an Hα emission line survey in a 1 deg{sup 2} area centered on the Orion Nebula Cluster, obtained with the Wide Field Grism Spectrograph 2 on the 2.2 m telescope of the University of Hawaii. We identified 587 stars with Hα emission, 99 of which, located mainly in the outer regions of the observed area, have not appeared in previous Hα surveys. We determined the equivalent width (EW) of the line and, based on this, classified 372 stars as classical T Tauri stars (CTTSs) and 187 as weak-line T Tauri stars (WTTSs). Simultaneous r', i' photometry indicates a limiting magnitude of r' ∼ 20 mag, but the sample is incomplete at r' > 17 mag. The surface distribution of the Hα emission stars reveals a clustered population and a dispersed population, the former consisting of younger and more massive young stars than the latter. Comparison of the derived EWs with those found in the literature indicates variability of the Hα line. We found that the typical amplitudes of the variability are not greater than a factor of two to three in most cases. We identified a subgroup of low-EW stars with infrared signatures indicative of optically thick accretion disks. We studied the correlations between the EW and other properties of the stars. Based on literature data, we examined several properties of our CTTS and WTTS subsamples and found significant differences in mid-infrared color indices, average rotational periods, and spectral energy distribution characteristics of the subsamples.

  12. Proper motion survey and kinematic analysis of the ρ Ophiuchi embedded cluster

    Science.gov (United States)

    Ducourant, C.; Teixeira, R.; Krone-Martins, A.; Bontemps, S.; Despois, D.; Galli, P. A. B.; Bouy, H.; Le Campion, J. F.; Rapaport, M.; Cuillandre, J. C.

    2017-01-01

    . Conclusions: We kinematically confirmed that the 56 members that were known from previous studies of the ρ Ophiuchi F cluster and that were also part of our survey are members of the cluster, and we added 26 new members. We defined the evolutionary status of the unclassified members of the cluster. We showed that a large part (23) of these new members are probably brown dwarfs, which multiplies the number of known substellar objects in the cluster by a factor of 3.3. Based on observations collected at the European Southern Observatory, Chile (64.I-0197, 67.C-0349, 69.C-0230, 71.C-0028, 73.C-0022, 83.D-0635).Full Tables 6-8 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/597/A90

  13. A Type II Supernova Hubble Diagram from the CSP-I, SDSS-II, and SNLS Surveys

    Science.gov (United States)

    de Jaeger, T.; González-Gaitán, S.; Hamuy, M.; Galbany, L.; Anderson, J. P.; Phillips, M. M.; Stritzinger, M. D.; Carlberg, R. G.; Sullivan, M.; Gutiérrez, C. P.; Hook, I. M.; Howell, D. Andrew; Hsiao, E. Y.; Kuncarayakti, H.; Ruhlmann-Kleider, V.; Folatelli, G.; Pritchet, C.; Basa, S.

    2017-02-01

    The coming era of large photometric wide-field surveys will increase the detection rate of supernovae by orders of magnitude. Such numbers will restrict spectroscopic follow-up in the vast majority of cases, and hence new methods based solely on photometric data must be developed. Here, we construct a complete Hubble diagram of Type II supernovae (SNe II) combining data from three different samples: the Carnegie Supernova Project-I, the Sloan Digital Sky Survey II SN, and the Supernova Legacy Survey. Applying the Photometric Color Method (PCM) to 73 SNe II with a redshift range of 0.01-0.5 and with no spectral information, we derive an intrinsic dispersion of 0.35 mag. A comparison with the Standard Candle Method (SCM) using 61 SNe II is also performed and an intrinsic dispersion in the Hubble diagram of 0.27 mag, I.e., 13% in distance uncertainties, is derived. Due to the lack of good statistics at higher redshifts for both methods, only weak constraints on the cosmological parameters are obtained. However, assuming a flat universe and using the PCM, we derive the universe’s matter density: {{{Ω }}}m={0.32}-0.21+0.30 providing a new independent evidence for dark energy at the level of two sigma. This paper includes data gathered with the 6.5 m Magellan Telescopes, with the du Pont and Swope telescopes located at Las Campanas Observatory, Chile; and the Gemini Observatory, Cerro Pachon, Chile (Gemini Program N-2005A-Q-11, GN-2005B-Q-7, GN-2006A-Q-7, GS-2005A-Q-11, GS-2005B-Q-6, and GS-2008B-Q-56). Based on observations collected at the European Organization for Astronomical Research in the Southern Hemisphere, Chile (ESO Programmes 076.A-0156,078.D-0048, 080.A-0516, and 082.A-0526).

  14. Electronic Structure and Oxidation State Changes in the Mn4Ca Cluster of Photosystem II

    Energy Technology Data Exchange (ETDEWEB)

    Yano, Junko; Pushkar, Yulia; Messinger, Johannes; Bergmann, Uwe; Glatzel, Pieter; Yachandra, Vittal K

    2007-08-03

    Oxygen-evolving complex (Mn4Ca cluster) of Photosystem II cycles through five intermediate states (Si-states, i =0-4) before a molecule of dioxygen is released. During the S-state transitions, electrons are extracted from the OEC, either from Mn or alternatively from a Mn ligand. The oxidation state of Mn is widely accepted as Mn4(III2,IV2) and Mn4(III,IV3) for S1 and S2 states, while it is still controversial for the S0 and S3 states. We used resonant inelastic X-ray scattering (RIXS) to study the electronic structure of Mn4Ca complex in the OEC. The RIXS data yield two-dimensional plots that provide a significant advantage by obtaining both K-edge pre-edge and L-edge-like spectra (metal spin state) simultaneously. We have collected data from PSII samples in the each of the S-states and compared them with data from various inorganic Mncomplexes. The spectral changes in the Mn 1s2p3/2 RIXS spectra between the S-states were compared to those of the oxides of Mn and coordination complexes. The results indicate strong covalency for the electronic configuration in the OEC, and we conclude that the electron is transferred from a strongly delocalized orbital, compared to those in Mn oxides or coordination complexes. The magnitude for the S0 to S1, and S1 to S2 transitions is twice as large as that during the S2 to S3 transition, indicating that the electron for this transition is extracted from a highly delocalized orbital with little change in charge density at the Mn atoms.

  15. Electronic Structure and Oxidation State Changes in the Mn (4) Ca Cluster of Photosystem II

    Energy Technology Data Exchange (ETDEWEB)

    Yano, J.; Pushkar, Y.; Messinger, J.; Bergmann, U.; Glatzel, P.; Yachandra, V.K.; /SLAC

    2012-08-17

    Oxygen-evolving complex (Mn{sub 4}Ca cluster) of Photosystem II cycles through five intermediate states (S{sub i}-states, i = 0-4) before a molecule of dioxygen is released. During the S-state transitions, electrons are extracted from the OEC, either from Mn or alternatively from a Mn ligand. The oxidation state of Mn is widely accepted as Mn{sub 4}(III{sub 2},IV{sub 2}) and Mn{sub 4}(III,IV{sub 3}) for S{sub 1} and S{sub 2} states, while it is still controversial for the S{sub 0} and S{sub 3} states. We used resonant inelastic X-ray scattering (RIXS) to study the electronic structure of Mn{sub 4}Ca complex in the OEC. The RIXS data yield two-dimensional plots that provide a significant advantage by obtaining both K-edge pre-edge and L-edge-like spectra (metal spin state) simultaneously. We have collected data from PSII samples in the each of the S-states and compared them with data from various inorganic Mn complexes. The spectral changes in the Mn 1s2p{sub 3/2} RIXS spectra between the S-states were compared to those of the oxides of Mn and coordination complexes. The results indicate strong covalency for the electronic configuration in the OEC, and we conclude that the electron is transferred from a strongly delocalized orbital, compared to those in Mn oxides or coordination complexes. The magnitude for the S{sub 0} to S{sub 1}, and S{sub 1} to S{sub 2} transitions is twice as large as that during the S{sub 2} to S{sub 3} transition, indicating that the electron for this transition is extracted from a highly delocalized orbital with little change in charge density at the Mn atoms.

  16. Legacy ExtraGalactic UV Survey with The Hubble Space Telescope: Stellar Cluster Catalogs and First Insights Into Cluster Formation and Evolution in NGC 628

    Science.gov (United States)

    Adamo, A.; Ryon, J. E.; Messa, M.; Kim, H.; Grasha, K.; Cook, D. O.; Calzetti, D.; Lee, J. C.; Whitmore, B. C.; Elmegreen, B. G.; Ubeda, L.; Smith, L. J.; Bright, S. N.; Runnholm, A.; Andrews, J. E.; Fumagalli, M.; Gouliermis, D. A.; Kahre, L.; Nair, P.; Thilker, D.; Walterbos, R.; Wofford, A.; Aloisi, A.; Ashworth, G.; Brown, T. M.; Chandar, R.; Christian, C.; Cignoni, M.; Clayton, G. C.; Dale, D. A.; de Mink, S. E.; Dobbs, C.; Elmegreen, D. M.; Evans, A. S.; Gallagher, J. S., III; Grebel, E. K.; Herrero, A.; Hunter, D. A.; Johnson, K. E.; Kennicutt, R. C.; Krumholz, M. R.; Lennon, D.; Levay, K.; Martin, C.; Nota, A.; Östlin, G.; Pellerin, A.; Prieto, J.; Regan, M. W.; Sabbi, E.; Sacchi, E.; Schaerer, D.; Schiminovich, D.; Shabani, F.; Tosi, M.; Van Dyk, S. D.; Zackrisson, E.

    2017-06-01

    We report the large effort that is producing comprehensive high-level young star cluster (YSC) catalogs for a significant fraction of galaxies observed with the Legacy ExtraGalactic UV Survey (LEGUS) Hubble treasury program. We present the methodology developed to extract cluster positions, verify their genuine nature, produce multiband photometry (from NUV to NIR), and derive their physical properties via spectral energy distribution fitting analyses. We use the nearby spiral galaxy NGC 628 as a test case for demonstrating the impact that LEGUS will have on our understanding of the formation and evolution of YSCs and compact stellar associations within their host galaxy. Our analysis of the cluster luminosity function from the UV to the NIR finds a steepening at the bright end and at all wavelengths suggesting a dearth of luminous clusters. The cluster mass function of NGC 628 is consistent with a power-law distribution of slopes ˜ -2 and a truncation of a few times 105 {M}⊙ . After their formation, YSCs and compact associations follow different evolutionary paths. YSCs survive for a longer time frame, confirming their being potentially bound systems. Associations disappear on timescales comparable to hierarchically organized star-forming regions, suggesting that they are expanding systems. We find mass-independent cluster disruption in the inner region of NGC 628, while in the outer part of the galaxy there is little or no disruption. We observe faster disruption rates for low mass (≤104 {M}⊙ ) clusters, suggesting that a mass-dependent component is necessary to fully describe the YSC disruption process in NGC 628. Based on observations obtained with the NASA/ESA Hubble Space Telescope, 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.

  17. Small-Scale Interstellar Structure Toward the Open Cluster CHI Persei-Fuse II

    Science.gov (United States)

    Sonneborn, George (Technical Monitor); Friedman, Scott

    2003-01-01

    The purpose of this study was to measure the physical conditions of gas along sight lines toward 6 stars in the core Chi Persei open cluster. These sight lines traverse gas in both the Orion and Perseus spiral arms of the Galaxy, at distances of 500 and 2000 pc, respectively. The stars have angular separations ranging from 45 to 280 arcsec; 60 arcsec corresponds to linear distances of 0.15 and 0.6 pc in the two arms. Thus, abundance variations in these observations would constitute evidence for small-scale variations in the properties of the interstellar medium. Ground-based Na I observations at high resolution (approx. 15 km/sec) toward 172 stars (including the 6 in this study) in the double open cluster h and Chi Persei have revealed complex spatial variation. These variations are especially evident in the gas at velocities of -40 and -55 km/sec, corresponding to the Perseus spiral arm. 21 cm observations of HI emission using the Low Resolution DRAO Survey, with a 12-arcmin beam, also show variations. Averaging the Na I apparent optical depth profiles of neighboring sight lines in order to mimic such a beam size reduces the variation, as compared to the individual Na I measurements, but still show variations larger than seen in the 21 cm profiles. Na I is not the dominant ionization state of Na in the interstellar medium. Thus, it is possible that the variations seen really trace physical structures in the interstellar medium, or they may simply result from variations in the radiation field seen by the gas, or be due to some other environmental circumstance. To distinguish among these possibilities in the present study we obtained FUSE spectra toward the 6 targets in order to measure the molecular hydrogen absorption profiles along these sight lines. The higher J states of H2 are populated by the ambient W radiation field, and thus can provide insight into the environment affecting the gas. If both the high and low J states reveal absorption line profiles with

  18. The Gaia-ESO Survey. Mg-Al anti-correlation in iDR4 globular clusters

    Science.gov (United States)

    Pancino, E.; Romano, D.; Tang, B.; Tautvaišienė, G.; Casey, A. R.; Gruyters, P.; Geisler, D.; San Roman, I.; Randich, S.; Alfaro, E. J.; Bragaglia, A.; Flaccomio, E.; Korn, A. J.; Recio-Blanco, A.; Smiljanic, R.; Carraro, G.; Bayo, A.; Costado, M. T.; Damiani, F.; Jofré, P.; Lardo, C.; de Laverny, P.; Monaco, L.; Morbidelli, L.; Sbordone, L.; Sousa, S. G.; Villanova, S.

    2017-05-01

    We use Gaia-ESO (GES) Survey iDR4 data to explore the Mg-Al anti-correlation in globular clusters that were observed as calibrators, as a demonstration of the quality of Gaia-ESO Survey data and analysis. The results compare well with the available literature, within 0.1 dex or less, after a small (compared to the internal spreads) offset between the UVES and GIRAFFE data of 0.10-0.15 dex was taken into account. In particular, for the first time we present data for NGC 5927, which is one of the most metal-rich globular clusters studied in the literature so far with [ Fe / H ] = - 0.39 ± 0.04 dex; this cluster was included to connect with the open cluster regime in the Gaia-ESO Survey internal calibration. The extent and shape of the Mg-Al anti-correlation provide strong constraints on the multiple population phenomenon in globular clusters. In particular, we studied the dependency of the Mg-Al anti-correlation extension with metallicity, present-day mass,and age of the clusters, using GES data in combination with a large set of homogenized literature measurements.We find a dependency with both metallicity and mass, which is evident when fitting for the two parameters simultaneously, but we do not find significant dependency with age. We confirm that the Mg-Al anti-correlation is not seen in all clusters, but disappears for the less massive or most metal-rich clusters. We also use our data set to see whether a normal anti-correlation would explain the low [Mg/α] observed in some extragalactic globular clusters, but find that none of the clusters in our sample can reproduce it; a more extreme chemical composition, such as that of NGC 2419, would be required. We conclude that GES iDR4 data already meet the requirements set by the main survey goals and can be used to study globular clusters in detail, even if the analysis procedures were not specifically designed for them. Based on data products from observations made with ESO Telescopes at the La Silla Paranal

  19. Centre-excised X-ray luminosity as an efficient mass proxy for future galaxy cluster surveys

    Science.gov (United States)

    Mantz, Adam B.; Allen, Steven W.; Morris, R. Glenn; von der Linden, Anja

    2018-01-01

    The cosmological constraining power of modern galaxy cluster catalogues can be improved by obtaining low-scatter mass proxy measurements for even a small fraction of sources. In the context of large upcoming surveys that will reveal the cluster population down to the group scale and out to high redshifts, efficient strategies for obtaining such mass proxies will be valuable. In this work, we use high-quality weak-lensing and X-ray mass estimates for massive clusters in current X-ray-selected catalogues to revisit the scaling relations of the projected, centre-excised X-ray luminosity (Lce), which previous work suggests correlates tightly with total mass. Our data confirm that this is the case with Lce having an intrinsic scatter at fixed mass comparable to that of gas mass, temperature or YX. Compared to the other proxies, however, Lce is less susceptible to systematic uncertainties due to background modelling, and can be measured precisely with shorter exposures. This opens up the possibility of using Lce to estimate masses for large numbers of clusters discovered by new X-ray surveys (e.g. eROSITA) directly from the survey data, as well as for clusters discovered at other wavelengths with relatively short follow-up observations. We describe a simple procedure for making such estimates from X-ray surface brightness data, and comment on the spatial resolution required to apply this method as a function of cluster mass and redshift. We also explore the potential impact of Chandra and XMM-Newton follow-up observations over the next decade on dark energy constraints from new cluster surveys.

  20. The fundamental structure of axis II personality disorders assessed in the National Epidemiologic Survey on Alcohol and Related Conditions.

    Science.gov (United States)

    Cox, Brian J; Sareen, Jitender; Enns, Murray W; Clara, Ian; Grant, Bridget F

    2007-12-01

    Little is known about the fundamental structure of core personality disorder psychopathology in the general population. The current study employed confirmatory factor analysis to evaluate competing models of patterns of personality disorder diagnoses in a nationally representative sample. DSM-IV and alternate models of the structure of personality disorder psychopathology were evaluated using data from the National Epidemiologic Survey on Alcohol and Related Conditions conducted between 2001 and 2002 (N = 43,093). Dimensional versus categorical representations of DSM-IV personality disorder structure were also tested. Face-to-face interviews were conducted in the United States. Participants were community-based respondents aged 18 years and older. Diagnoses and dimensional scores were made for antisocial, avoidant, dependent, histrionic, obsessive-compulsive, paranoid, and schizoid personality disorders. Multiple goodness-of-fit indicators provided support for a DSM-IV-based hierarchical model of personality disorders. In this model, the individual personality disorders were viewed as belonging to 1 of 3 latent factors or clusters (A, B, or C). In all of the models, the individual personality disorders were allowed to be an indicator for only a single latent cluster, and errors were not allowed to correlate with each other. In turn, these 3 clusters were viewed as comprising a single higher-order "Axis II personality disorder factor." The DSM-IV model was largely invariant across gender, Axis I comorbidity, and treatment-seeking status. A dimensionally based form of assessment of the DSM-IV personality disorders produced excellent goodness-of-fit indicators and produced low Akaike information criterion values (which are indicative of better-fitting models). The results from this confirmatory factor analysis in a large, nationally representative mental health survey supported the DSM-IV hierarchical organization of Axis II personality disorders. This model was

  1. A SURVEY ON ANALYZING THE IMPACT OF BASEL II STANDARDS OVER SMES

    Directory of Open Access Journals (Sweden)

    NEVİN YÖRÜK

    2013-06-01

    Full Text Available Basel-II is a comprehensive arrangement that determines the standards of capital adequacy of banks and brings risk management in the foreground. It will be performed in European Union and G-10 countries beginning from 2009 and in our country beginning from 2009. The targets of Basel-II standards are increasing the risk measurement and capacity of banks and in this way providing to have a stronger banking system. However Basel-II arrangements are intended for banking and finance system, it concerns SMEs closely that want to use credit from system. Crossing from process of traditional credit granting to process of risk focused credit granting with Basel-II, period, volume, price and guarentee of credits that will be used by SMEs will be affected. A survey was conducted for determining SMEs’ level of understanding and performing the international Basel-II standards that are planned to put into practice in Turkey beginning from 2007, for determining the financing problems of firms in process of transition to Basel-II, for researching the potential competition between SMEs created by Basel-II standards. According to results of survey the SMEs of Amasya have knowledge about Basel-II criteria and think that they will not face any problems in the process of transition.

  2. A Photometric redshift galaxy catalog from the Red-Sequence Cluster Survey

    Energy Technology Data Exchange (ETDEWEB)

    Hsieh, Bau-Ching; /Taiwan, Natl. Central U. /Taipei, Inst. Astron. Astrophys.; Yee, H.K.C.; /Toronto U., Astron. Dept.; Lin, H.; /Fermilab; Gladders, M.D.; /Carnegie Inst.

    2005-02-01

    The Red-Sequence Cluster Survey (RCS) provides a large and deep photometric catalog of galaxies in the z' and R{sub c} bands for 90 square degrees of sky, and supplemental V and B data have been obtained for 33.6 deg{sup 2}. They compile a photometric redshift catalog from these 4-band data by utilizing the empirical quadratic polynomial photometric redshift fitting technique in combination with CNOC2 and GOODS/HDF-N redshift data. The training set includes 4924 spectral redshifts. The resulting catalog contains more than one million galaxies with photometric redshifts < 1.5 and R{sub c} < 24, giving an rms scatter {delta}({Delta}z) < 0.06 within the redshift range 0.2 < z < 0.5 and {sigma}({Delta}z) < 0.11 for galaxies at 0.0 < z < 1.5. They describe the empirical quadratic polynomial photometric redshift fitting technique which they use to determine the relation between red-shift and photometry. A kd-tree algorithm is used to divide up the sample to improve the accuracy of the catalog. They also present a method for estimating the photometric redshift error for individual galaxies. They show that the redshift distribution of the sample is in excellent agreement with smaller and much deeper photometric and spectroscopic redshift surveys.

  3. The Next Generation Virgo Cluster Survey. XXVIII. Characterization of the Galactic White Dwarf Population

    Energy Technology Data Exchange (ETDEWEB)

    Fantin, Nicholas J. [Department of Physics and Astronomy,University of Victoria, Victoria, BC, V8P 1A1 (Canada); Côté, Patrick; Gwyn, S. D. J.; Ferrarese, Laura; McConnachie, Alan [National Research Council of Canada, Herzberg Astronomy and Astrophysics Program, 5071 W. Saanich Road, Victoria, BC, V9E 2E7 (Canada); Hanes, David A. [Queen’s University, Department of Physics, Engineering Physics and Astronomy, Kingston, Ontario (Canada); Bianchi, Luciana [Department of Physics and Astronomy, The Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218 (United States); Cuillandre, Jean-Charles [CEA/IRFU/SAp, Laboratoire AIM Paris-Saclay, CNRS/INSU, Université Paris Diderot, Observatoire de Paris, PSL Research University, F-91191 Gif-sur-Yvette Cedex (France); Starkenburg, Else, E-mail: nfantin@uvic.ca [Leibniz Institute for Astrophysics Potsdam (AIP), An der Sternwarte 16, D-14482 Potsdam (Germany)

    2017-07-01

    We use three different techniques to identify hundreds of white dwarf (WD) candidates in the Next Generation Virgo Cluster Survey (NGVS) based on photometry from the NGVS and GUViCS, and proper motions derived from the NGVS and the Sloan Digital Sky Survey (SDSS). Photometric distances for these candidates are calculated using theoretical color–absolute magnitude relations, while effective temperatures are measured by fitting their spectral energy distributions. Disk and halo WD candidates are separated using a tangential velocity cut of 200 km s{sup −1} in a reduced proper motion diagram, which leads to a sample of six halo WD candidates. Cooling ages, calculated for an assumed WD mass of 0.6 M {sub ⊙}, range between 60 Myr and 6 Gyr, although these estimates depend sensitively on the adopted mass. Luminosity functions for the disk and halo subsamples are constructed and compared to previous results from the SDSS and SuperCOSMOS survey. We compute a number density of (2.81 ± 0.52) × 10{sup −3} pc{sup −3} for the disk WD population—consistent with previous measurements. We find (7.85 ± 4.55) × 10{sup −6} pc{sup −3} for the halo, or 0.3% of the disk. Observed stellar counts are also compared to predictions made by the TRILEGAL and Besançon stellar population synthesis models. The comparison suggests that the TRILEGAL model overpredicts the total number of WDs. The WD counts predicted by the Besançon model agree with the observations, although a discrepancy arises when comparing the predicted and observed halo WD populations; the difference is likely due to the WD masses in the adopted model halo.

  4. Surgical need in an aging population: A cluster-based household survey in Nepal.

    Science.gov (United States)

    Stewart, Barclay T; Wong, Evan; Gupta, Shailvi; Bastola, Santosh; Shrestha, Sunil; Kushner, Adam L; Nwomeh, Benedict C

    2015-05-01

    With an aging global population comes an obligate and substantial burden of noncommunicable disease, especially in low- and middle-income countries. An unknown proportion of this burden is treatable with surgical expertise. For health system planning, this study aimed to estimate the operative needs of individuals older than 50 of age years in Nepal. A 2-stage, cluster randomized, community-based survey was performed in Nepal using the validated Surgeons OverSeas Surgical Assessment Survey (SOSAS). SOSAS collects household demographics and selects household members randomly for verbal, head-to-toe examinations for surgical conditions; moreover, SOSAS also completes a verbal autopsy for deaths in the preceding year. Only respondents older than 50 years were included in the analysis. The survey sampled 1,350 households, totaling 2,695 individuals (97% response rate). Of these, 273 surgical conditions were reported by 507 persons ages ≥ 50 years. Extrapolating, there are potentially 2.1 million people older than 50 years of age with surgically treatable conditions who need care in Nepal (95% confidence interval 1.8-2.4 million; 46,000-62,600 per 100,000 persons). One in 5 deaths was potentially treatable or palliated by surgical care. Although growths or masses (including hernias and goiters) were the surgical condition reported most commonly (25%), injuries and fractures also were common and associated with the greatest disability. Literacy and distance to secondary and tertiary health facilities were associated with lack of care for operative conditions (P Nepal. Low literacy and distance from a capable health facility are the greatest barriers to care. As the global population ages, there is an increasing need to improve surgical services and strengthen health systems to care for this group. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Evolution of cluster X-ray luminosities and radii: Results from the 160 square degree rosat survey

    DEFF Research Database (Denmark)

    Vikhlinin, A.; McNamara, B.R.; Forman, W.

    1998-01-01

    We searched for cluster X-ray luminosity and radius evolution using our sample of 203 galaxy clusters detected in the 160 deg(2) survey with the ROSAT PSPC (Vikhlinin et al.). With such a large area survey, it is possible, for the first time with ROSAT, to test the evolution of luminous clusters, L-X...... > 3 x 10(44) ergs s(-1) in the 0.5-2 keV band. We detect a factor of 3-4 deficit of such luminous clusters at z > 0.3 compared with the present. The evolution is much weaker or absent at modestly lower luminosities, (1-3) x 10(44) ergs s(-1). At still lower luminosities, we find no evolution from...... the analysis of the log N-log S relation. The results in the two upper L, bins are in agreement with the Einstein Extended Medium-Sensitivity Survey evolution result (Gioia et al.; Henry ct al.), which was obtained using a completely independent cluster sample. The low-L-X results are in agreement with other...

  6. The Core Collapse Supernova Rate from the SDSS-II Supernova Survey

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Matt; Cinabro, David; Dilday, Ben; Galbany, Lluis; Gupta, Ravi R.; Kessler, R.; Marriner, John; Nichol, Robert C.; Richmond, Michael; Schneider, Donald P.; Sollerman, Jesper

    2014-08-26

    We use the Sloan Digital Sky Survey II Supernova Survey (SDSS-II SNS) data to measure the volumetric core collapse supernova (CCSN) rate in the redshift range (0.03 < z < 0.09). Using a sample of 89 CCSN, we find a volume-averaged rate of 1.06 ± 0.19 × 10(–)(4)((h/0.7)(3)/(yr Mpc(3))) at a mean redshift of 0.072 ± 0.009. We measure the CCSN luminosity function from the data and consider the implications on the star formation history.

  7. THE CARNEGIE-IRVINE GALAXY SURVEY. II. ISOPHOTAL ANALYSIS

    Energy Technology Data Exchange (ETDEWEB)

    Li Zhaoyu [Department of Astronomy, School of Physics, Peking University, Beijing 100871 (China); Ho, Luis C. [The Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Barth, Aaron J. [Department of Physics and Astronomy, 4129 Frederick Reines Hall, University of California, Irvine, CA 92697-4575 (United States); Peng, Chien Y. [NRC Herzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada)

    2011-12-01

    The Carnegie-Irvine Galaxy Survey (CGS) is a comprehensive investigation of the physical properties of a complete, representative sample of 605 bright (B{sub T} {<=} 12.9 mag) galaxies in the southern hemisphere. This contribution describes the isophotal analysis of the broadband (BVRI) optical imaging component of the project. We pay close attention to sky subtraction, which is particularly challenging for some of the large galaxies in our sample. Extensive crosschecks with internal and external data confirm that our calibration and sky subtraction techniques are robust with respect to the quoted measurement uncertainties. We present a uniform catalog of one-dimensional radial profiles of surface brightness and geometric parameters, as well as integrated colors and color gradients. Composite profiles highlight the tremendous diversity of brightness distributions found in disk galaxies and their dependence on Hubble type. A significant fraction of S0 and spiral galaxies exhibit non-exponential profiles in their outer regions. We perform Fourier decomposition of the isophotes to quantify non-axisymmetric deviations in the light distribution. We use the geometric parameters, in conjunction with the amplitude and phase of the m = 2 Fourier mode, to identify bars and quantify their size and strength. Spiral arm strengths are characterized using the m = 2 Fourier profiles and structure maps. Finally, we utilize the information encoded in the m = 1 Fourier profiles to measure disk lopsidedness. The databases assembled here and in Paper I lay the foundation for forthcoming scientific applications of CGS.

  8. Clustering and meso-level variables in cross-sectional surveys: an example of food aid during the Bosnian crisis.

    Science.gov (United States)

    Andersson, Neil; Lamothe, Gilles

    2011-12-21

    Focus groups, rapid assessment procedures, key informant interviews and institutional reviews of local health services provide valuable insights on health service resources and performance. A long-standing challenge of health planning is to combine this sort of qualitative evidence in a unified analysis with quantitative evidence from household surveys. A particular challenge in this regard is to take account of the neighbourhood or clustering effects, recognising that these can be informative or incidental. An example of food aid and food sufficiency from the Bosnian emergency (1995-96) illustrates two Lamothe cluster-adjustments of the Mantel Haenszel (MH) procedure, one assuming a fixed odds ratio and the other allowing for informative clustering by not assuming a fixed odds ratio. We compared these with conventional generalised estimating equations and a generalised linear mixed (GLMM) model, using a Laplace adjustment. The MH adjustment assuming incidental clustering generated a final model very similar to GEE. The adjustment that does not assume a fixed odds ratio produced a final multivariate model and effect sizes very similar to GLMM. In medium or large data sets with stratified last stage random sampling, the cluster adjusted MH is substantially more conservative than the naïve MH computation. In the example of food aid in the Bosnian crisis, the cluster adjusted MH that does not assume a fixed odds ratio produced similar results to the GLMM, which identified informative clustering.

  9. The XMM-LSS survey: the Class 1 cluster sample over the initial 5 deg2 and its cosmological modelling

    Science.gov (United States)

    Pacaud, F.; Pierre, M.; Adami, C.; Altieri, B.; Andreon, S.; Chiappetti, L.; Detal, A.; Duc, P.-A.; Galaz, G.; Gueguen, A.; Le Fèvre, J.-P.; Hertling, G.; Libbrecht, C.; Melin, J.-B.; Ponman, T. J.; Quintana, H.; Refregier, A.; Sprimont, P.-G.; Surdej, J.; Valtchanov, I.; Willis, J. P.; Alloin, D.; Birkinshaw, M.; Bremer, M. N.; Garcet, O.; Jean, C.; Jones, L. R.; Le Fèvre, O.; Maccagni, D.; Mazure, A.; Proust, D.; Röttgering, H. J. A.; Trinchieri, G.

    2007-12-01

    We present a sample of 29 galaxy clusters from the XMM-LSS survey over an area of some 5 deg2 out to a redshift of z = 1.05. The sample clusters, which represent about half of the X-ray clusters identified in the region, follow well-defined X-ray selection criteria and are all spectroscopically confirmed. For all clusters, we provide X-ray luminosities and temperatures as well as masses, obtained from dedicated spatial and spectral fitting. The cluster distribution peaks around z = 0.3 and T = 1.5 keV, half of the objects being groups with a temperature below 2 keV. Our LX-T(z) relation points towards self-similar evolution, but does not exclude other physically plausible models. Assuming that cluster scaling laws follow self-similar evolution, our number density estimates up to z = 1 are compatible with the predictions of the concordance cosmology and with the findings of previous ROSAT surveys. Our well-monitored selection function allowed us to demonstrate that the inclusion of selection effects is essential for the correct determination of the evolution of the LX-T relation, which may explain the contradictory results from previous studies. Extensive simulations show that extending the survey area to 10 deg2 has the potential to exclude the non-evolution hypothesis, but those constraints on more refined intracluster medium models will probably be limited by the large intrinsic dispersion of the LX-T relation, whatever be the sample size. We further demonstrate that increasing the dispersion in the scaling laws increases the number of detectable clusters, hence generating further degeneracy [in addition to σ8,Ωm, LX-T(z)] in the cosmological interpretation of the cluster number counts. We provide useful empirical formulae for the cluster mass-flux and mass-count rate relations as well as a comparison between the XMM-LSS mass sensitivity and that of forthcoming Sunyaev-Zel'dovich surveys. Based on data collected with XMM, Very Large Telescope, Magellan, NTT and

  10. Synchrotron Emission from Dark Matter Annihilation: Predictions for Constraints from Non-detections of Galaxy Clusters with New Radio Surveys

    Science.gov (United States)

    Storm, Emma; Jeltema, Tesla E.; Splettstoesser, Megan; Profumo, Stefano

    2017-04-01

    The annihilation of dark matter particles is expected to yield a broad radiation spectrum via the production of Standard Model particles in astrophysical environments. In particular, electrons and positrons from dark matter annihilation produce synchrotron radiation in the presence of magnetic fields. Galaxy clusters are the most massive collapsed structures in the universe, and are known to host ˜μG-scale magnetic fields. They are therefore ideal targets to search for, or to constrain the synchrotron signal from dark matter annihilation. In this work, we use the expected sensitivities of several planned surveys from the next generation of radio telescopes to predict the constraints on dark matter annihilation models which will be achieved in the case of non-detections of diffuse radio emission from galaxy clusters. Specifically, we consider the Tier 1 survey planned for the Low Frequency Array (LOFAR) at 120 MHz, the Evolutionary Map of the Universe (EMU) survey planned for the Australian Square Kilometre Array Pathfinder (ASKAP) at 1.4 GHz, and planned surveys for Aperture Tile in Focus (APERTIF) at 1.4 GHz. We find that, for massive clusters and dark matter masses ≲ 100 {GeV}, the predicted limits on the annihilation cross section would rule out vanilla thermal relic models for even the shallow LOFAR Tier 1, ASKAP, and APERTIF surveys.

  11. VizieR Online Data Catalog: Survey of Centaurus A's Baryonic Structures II. (Taylor+, 2017)

    Science.gov (United States)

    Taylor, M. A.; Puzia, T. H.; Munoz, R. P.; Mieske, S.; Lancon, A.; Zhang, H.; Eigenthaler, P.; Bovill, M. S.

    2018-01-01

    The Survey of Centaurus A's Baryonic Structures is an optical survey of the nearby giant elliptical galaxy NGC5128 (Centaurus A) using the Dark Energy Camera. This work focussed on identifying globular cluster candidates of 22 sq. degrees centred on NGC5128. In doing so we produced a list of ~4.4x105 point, and point-like sources in the optical u'g'r'i'z' bands with 50/90% completeness limits of at least 24.08/23.62, 22.67/22.27, 22.46/22.00, 22.05/21.63, and 21.71/21.34 AB mags, respectively. The same data is also included for a list of ~3000 highly probable globular cluster candidates Positional data is typically accurate to at least 0.5". (4 data files).

  12. Age and helium content of the open cluster NGC 6791 from multiple eclipsing binary members. II

    DEFF Research Database (Denmark)

    Brogaard, K.; VandenBerg, D. A.; Bruntt, H.

    2012-01-01

    Models of stellar structure and evolution can be constrained by measuring accurate parameters of detached eclipsing binaries in open clusters. Multiple binary stars provide the means to determine helium abundances in these old stellar systems, and in turn, to improve estimates of their age....... In the first paper of this series, we demonstrated how measurements of multiple eclipsing binaries in the old open cluster NGC6791 sets tighter constraints on the properties of stellar models than has previously been possible, thereby potentially improving both the accuracy and precision of the cluster age....... Here we add additional constraints and perform an extensive model comparison to determine the best estimates of the cluster age and helium content, employing as many observational constraints as possible. We improve our photometry and correct empirically for differential reddening effects. We...

  13. C II 158 ??bservations of a Sample of Late-type Galaxies from the Virgo Cluster

    Science.gov (United States)

    Leech, K.; Volk, H.; Heinrichsen, I.; Hippelein, H.; Metcalfe, L.; Pierini, D.; Popescu, C.; Tuffs, R.; Xu, C.

    1999-01-01

    We have observed 19 Virgo cluster spiral galaxies with the Long Wavelength Spectrometer (LWS) onboard ESAs Infrared Space Observatory (ISO) obtaining spectra around the [CII] 157.741 ??ine structure line.

  14. Does aspartate 170 of the D1 polypeptide ligate the manganese cluster in photosystem II? An EPR and ESEEM Study.

    Science.gov (United States)

    Debus, Richard J; Aznar, Constantino; Campbell, Kristy A; Gregor, Wolfgang; Diner, Bruce A; Britt, R David

    2003-09-16

    Aspartate 170 of the D1 polypeptide provides part of the high-affinity binding site for the first Mn(II) ion that is photooxidized during the light-driven assembly of the (Mn)(4) cluster in photosystem II [Campbell, K. A., Force, D. A., Nixon, P. J., Dole, F., Diner, B. A., and Britt, R. D. (2000) J. Am. Chem. Soc. 122, 3754-3761]. However, despite a wealth of data on D1-Asp170 mutants accumulated over the past decade, there is no consensus about whether this residue ligates the assembled (Mn)(4) cluster. To address this issue, we have conducted an EPR and ESEEM (electron spin-echo envelope modulation) study of D1-D170H PSII particles purified from the cyanobacterium Synechocystis sp. PCC 6803. The line shapes of the S(1) and S(2) state multiline EPR signals of D1-D170H PSII particles are unchanged from those of wild-type PSII particles, and the signal amplitudes correlate approximately with the lower O(2) evolving activity of the mutant PSII particles (40-60% compared to that of the wild type). These data provide further evidence that the assembled (Mn)(4) clusters in D1-D170H cells function normally, even though the assembly of the (Mn)(4) cluster is inefficient in this mutant. In the two-pulse frequency domain ESEEM spectrum of the 9.2 GHz S(2) state multiline EPR signal of D1-D170H PSII particles, the histidyl nitrogen modulation observed at 4-5 MHz is unchanged from that of wild-type PSII particles and no significant new modulation is observed. Three scenarios are presented to explain this result. (1) D1-Asp170 ligates the assembled (Mn)(4) cluster, but the hyperfine couplings to the ligating histidyl nitrogen of D1-His170 are too large or anisotropic to be detected by ESEEM analyses conducted at 9.2 GHz. (2) D1-Asp170 ligates the assembled (Mn)(4) cluster, but D1-His170 does not. (3) D1-Asp170 does not ligate the assembled (Mn)(4) cluster.

  15. The injury burden of the 2010 Haiti earthquake: a stratified cluster survey.

    Science.gov (United States)

    Doocy, Shannon; Jacquet, Gabrielle; Cherewick, Megan; Kirsch, Thomas D

    2013-06-01

    On January 12, 2010, a 7.0 magnitude earthquake devastated metropolitan Port au Prince and surrounding areas and resulted in widespread injury, mortality and displacement. This study aimed to estimate the injury rate among the affected population and the resulting demand of emergency medical care in the aftermath of the earthquake. In January 2011, a cross-sectional stratified cluster (60×20 household) survey of the earthquake-affected population in metropolitan Port au Prince was conducted to assess their well-being, unmet needs and perceptions of humanitarian assistance one year post-earthquake. Mixed effects simple and multiple logistic regressions were used to measure the total unadjusted and adjusted odds of injury. A total of 261 injuries were reported in the pre-earthquake population of 6489 individuals with reported injury status. The overall earthquake injury rate was estimated at 40.2 injuries/1000 (CI: 35.6-45.3). Individual characteristics such as age, gender, and education status were not significantly associated with risk of injury. Elevated injury rates were observed among households residing in camps at 46.7/1000 (CI: 39.7-54.5) as compared to those in neighbourhoods where the injury rate was 33.7/1000 (CI: 27.8-40.5) (p=0.018). Extrapolation of the survey injury rate to the affected population yields an estimated 124,577 earthquake injuries (range 110,048-140,033) which is substantially lower than the 300,000 reported injuries. Estimates of the injury burden in disasters in lower- and middle-income countries is essential for disaster preparedness and response planning in future natural disasters. Given the difficulties in reporting injuries in emergencies, including both challenges of aggregating information and lack of standardized definitions and inclusion/exclusion criteria for injuries that are not severe, ascertaining the injury burden of disasters will be a persistent challenge. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Beyond MACS: A Snapshot Survey of the Most Massive Clusters of Galaxies at z>0.5

    Science.gov (United States)

    Ebeling, Harald

    2017-08-01

    Truly massive galaxy clusters play a pivotal role for a wealth of extragalactic and cosmological research topics, and SNAPshot observations of these systems are ideally suited to identify the most promising cluster targets for further, in-depth study. The power of this approach was demonstrated by ACS/WFC3 SNAPshots of X-ray selected MACS and eMACS clusters at z>0.3 obtained by us in previous Cycles (44 of them in all of F606W, F814W, F110W, and F140W). Based on these data, the CLASH MCT program selected 16 out of 25 of their targets to be MACS clusters. Similarly, all but one of the six most powerful cluster lenses selected for in-depth study by the HST Frontier Fields initiative are MACS detections, and so are 16 of the 29 z>0.3 clusters targeted by the RELICS legacy program.We propose to extend our spectacularly successful SNAPshot survey of the most X-ray luminous distant clusters to a redshift-mass regime that is poorly sampled by any other project. Targeting only extremely massive clusters at z>0.5 from the X-ray selected eMACS sample (median velocity dispersion: 1180 km/s), the proposed program will (a) identify the most powerful gravitational telescopes at yet higher redshift for the next generation of in-depth studies of the distant Universe with HST and JWST, (b) provide constraints on the mass distribution within these extreme systems, (c) help improve our understanding of the physical nature of galaxy-galaxy and galaxy-gas interactions in cluster cores, and (d) unveil Balmer Break Galaxies at z 2 and Lyman-break galaxies at z>6 as F814W dropouts.Acknowledging the broad community interest in our sample we waive our data rights for these observations.

  17. A VLA Survey for Faint Compact Radio Sources in the Orion Nebula Cluster

    Science.gov (United States)

    Sheehan, Patrick D.; Eisner, Josh A.; Mann, Rita K.; Williams, Jonathan P.

    2016-11-01

    We present Karl G. Jansky Very Large Array 1.3, 3.6, and 6 cm continuum maps of compact radio sources in the Orion Nebular Cluster (ONC). We mosaicked 34 arcmin2 at 1.3 cm, 70 arcmin2 at 3.6 cm and 109 arcmin2 at 6 cm, containing 778 near-infrared detected young stellar objects and 190 Hubble Space Telescope-identified proplyds (with significant overlap between those characterizations). We detected radio emission from 175 compact radio sources in the ONC, including 26 sources that were detected for the first time at these wavelengths. For each detected source, we fitted a simple free-free and dust emission model to characterize the radio emission. We extrapolate the free-free emission spectrum model for each source to ALMA bands to illustrate how these measurements could be used to correctly measure protoplanetary disk dust masses from submillimeter flux measurements. Finally, we compare the fluxes measured in this survey with previously measured fluxes for our targets, as well as four separate epochs of 1.3 cm data, to search for and quantify the variability of our sources.

  18. Clustering of High Redshift (z>2.9) Quasars from the Sloan Digital Sky Survey

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Yue; Strauss, Michael A.; Oguri, Masamune; Hennawi, Joseph F.; Fan, Xiaohui; Richards, Gordon T.; Hall, Patrick B.; Schneider, Donald P.; Szalay, Alexander S.; Thakar, Anirudda R.; Berk, Daniel E.Vanden; Anderson, Scott F.; Bahcall, Neta A.; /KIPAC, Menlo Park

    2006-11-30

    We study the two-point correlation function of a uniformly selected sample of 4,428 optically selected luminous quasars with redshift 2.9 {le} z {le} 5.4 selected over 4041 deg{sup 2} from the Fifth Data Release of the Sloan Digital Sky Survey. We fit a power-law to the projected correlation function w{sub p}(r{sub p}) to marginalize over redshift space distortions and redshift errors. For a real-space correlation function of the form {zeta}(r) = (r/r{sub 0}){sup -{gamma}}, the fitted parameters in comoving coordinates are r{sub 0} = 15.2 {+-} 2.7 h{sup -1} Mpc and {gamma} = 2.0 {+-} 0.3, over a scale range 4 {le} r{sub p} {le} 150 h{sup -1} Mpc. Thus high-redshift quasars are appreciably more strongly clustered than their z {approx} 1.5 counterparts, which have a comoving clustering length r{sub 0} {approx} 6.5 h{sup -1} Mpc. Dividing our sample into two redshift bins: 2.9 {le} z {le} 3.5 and z {ge} 3.5, and assuming a power-law index {gamma} = 2.0, we find a correlation length of r{sub 0} = 16.9 {+-} 1.7 h{sup -1} Mpc for the former, and r{sub 0} = 24.3 {+-} 2.4 h{sup -1} Mpc for the latter. Strong clustering at high redshift indicates that quasars are found in very massive, and therefore highly biased, halos. Following Martini & Weinberg, we relate the clustering strength and quasar number density to the quasar lifetimes and duty cycle. Using the Sheth & Tormen halo mass function, the quasar lifetime is estimated to lie in the range 4 {approx} 50 Myr for quasars with 2.9 {le} z {le} 3.5; and 30 {approx} 600 Myr for quasars with z {ge} 3.5. The corresponding duty cycles are 0.004 {approx} 0.05 for the lower redshift bin and 0.03 {approx} 0.6 for the higher redshift bin. The minimum mass of halos in which these quasars reside is 2-3 x 10{sup 12} h{sup -1} M{sub {circle_dot}} for quasars with 2.9 {le} z {le} 3.5 and 4-6 x 10{sup 12} h{sup -1} M{sub {circle_dot}} for quasars with z {ge} 3.5; the effective bias factor b{sub eff} increases with redshift, e.g., b

  19. Calcium EXAFS establishes the Mn-Ca cluster in the oxygen-evolving complex of Photosystem II

    Energy Technology Data Exchange (ETDEWEB)

    Cinco, Roehl M.; McFarlane Holman, Karen L.; Robblee, John H.; Yano, Junko; Pizarro, Shelly A.; Bellacchio, Emanuele; Sauer, Kenneth; Yachandra, Vittal K.

    2002-08-02

    The proximity of Ca to the Mn cluster of the photosynthetic water-oxidation complex is demonstrated by X-ray absorption spectroscopy. We have collected EXAFS data at the Ca K-edge using active PS II membrane samples that contain approximately 2 Ca per 4 Mn. These samples are much less perturbed than previously investigated Sr-substituted samples, which were prepared subsequent to Ca depletion. The new Ca EXAFS clearly shows backscattering from Mn at 3.4 angstroms, a distance that agrees with that surmised from previously recorded Mn EXAFS. This result is also consistent with earlier related experiments at the Sr K-edge, using samples that contained functional Sr, that show Mn is {approx}; 3.5 angstroms distant from Sr. The totality of the evidence clearly advances the notion that the catalytic center of oxygen evolution is a Mn-Ca heteronuclear cluster.

  20. Photometry of Type II Cepheid Candidates from the Northern Part of the All Sky Automated Survey

    Science.gov (United States)

    Schmidt, Edward G.; Hemen, Brian; Rogalla, Danielle; Thacker-Lynn, Lauren

    2009-06-01

    We have obtained VR photometry of 282 Cepheid variable star candidates from the northern part of the All Sky Automated Survey (ASAS). These together with data from the ASAS and the Northern Sky Variability Survey (NSVS) were used to redetermine the periods of the stars. We divided the stars into four groups based on location in a plot of mean color, langV-Rrang, versus period. Two of the groups fell within the region of the diagram containing known type II Cepheids and yielded 14 new highly probable type II Cepheids. The properties of the remaining stars in these two groups are discussed but their nature remains uncertain. Unexplained differences exist between the sample of stars studied here and a previous sample drawn from the NSVS by Akerlof et al. This suggests serious biases in the identification of variables in different surveys.

  1. THE NEXT GENERATION VIRGO CLUSTER SURVEY. VI. THE KINEMATICS OF ULTRA-COMPACT DWARFS AND GLOBULAR CLUSTERS IN M87

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hong-Xin; Peng, Eric W.; Li, Biao [Department of Astronomy, Peking University, Beijing 100871 (China); Côté, Patrick; Ferrarese, Laura; Gwyn, Stephen D. J.; Blakeslee, John P. [National Research Council of Canada, Herzberg Astronomy and Astrophysics Program, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Liu, Chengze [Center for Astronomy and Astrophysics, Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Cuillandre, Jean-Charles [Canada-France-Hawaii Telescope Corporation, Kamuela, HI 96743 (United States); Caldwell, Nelson [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Jordán, Andrés; Muñoz, Roberto P.; Puzia, Thomas H. [Instituto de Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, 7820436 Macul, Santiago (Chile); Lançon, Ariane [Observatoire astronomique de Strasbourg, Université de Strasbourg, CNRS, UMR 7550, 11 rue de l' Universite, F-67000 Strasbourg (France); Bekki, Kenji [School of Physics, University of New South Wales, Sydney 2052, NSW (Australia); Boselli, Alessandro [Aix Marseille Université, CNRS, LAM (Laboratoire d' Astrophysique de Marseille) UMR 7326, F-13388 Marseille (France); Drinkwater, Michael J. [School of Mathematics and Physics, University of Queensland, Brisbane, QLD 4072 (Australia); Duc, Pierre-Alain, E-mail: hongxin@pku.edu.cn, E-mail: peng@pku.edu.cn [Laboratoire AIM Paris-Saclay, CNRS/INSU, Université Paris Diderot, CEA/IRFU/SAp, F-91191 Gif-sur-Yvette Cedex (France); and others

    2015-03-20

    The origin of ultra-compact dwarfs (UCDs; r{sub h} ≳ 10 pc)—objects larger and more massive than typical globular clusters (GCs), but more compact than typical dwarf galaxies—has been hotly debated in the 15 years since their discovery. Even whether UCDs should be considered galactic in origin, or simply the most extreme star clusters, is not yet settled. We present the dynamical properties of 97 spectroscopically confirmed UCDs and 911 GCs associated with the central cD galaxy of the Virgo cluster, M87. Our UCDs, of which 89% have M {sub *} ≳ 2× 10{sup 6} M {sub ☉} and 92% are as blue as the classic blue GCs, nearly triple the confirmed sample of Virgo UCDs, providing by far the best opportunity for studying global dynamics of a UCD system. We found that (1) UCDs have a surface number density profile that is shallower than that of blue GCs in the inner ∼70 kpc and as steep as that of red GCs at larger radii; (2) UCDs exhibit a significantly stronger rotation than GCs, and blue GCs seem to have a velocity field that is more consistent with that of the surrounding dwarf ellipticals than with that of UCDs; (3) UCDs have an orbital anisotropy profile that is tangentially biased at radii ≲40 kpc and radially biased farther out, whereas blue GCs become more tangentially biased at larger radii beyond ∼40 kpc; (4) GCs with M {sub *} ≳ 2 × 10{sup 6} M {sub ☉} have rotational properties indistinguishable from the less massive ones, suggesting that it is the size, instead of mass, that differentiates UCDs from GCs as kinematically distinct populations. We conclude that most UCDs in M87 are not consistent with being merely the most luminous and extended examples of otherwise normal GCs. The radially biased orbital structure of UCDs at large radii is in general agreement with the 'tidally threshed dwarf galaxy' scenario.

  2. Galaxy-galaxy and galaxy-cluster lensing with the SDSS and FIRST surveys

    Science.gov (United States)

    Demetroullas, C.; Brown, M. L.

    2018-01-01

    We perform a galaxy-galaxy lensing study by correlating the shapes of ∼2.7 × 105 galaxies selected from the VLA FIRST (Faint Images of the Radio Sky at Twenty centimetres) radio survey with the positions of ∼38.5 million Sloan Digital Sky Survey (SDSS) galaxies, ∼132 000 Brightest Cluster Galaxies (BCGs) and ∼78 000 SDSS galaxies that are also detected in the VLA FIRST survey. The measurements are conducted on angular scales θ ≲ 1200 arcsec. On scales θ ≲ 200 arcsec, we find that the measurements are corrupted by residual systematic effects associated with the instrumental beam of the VLA data. Using simulations, we show that we can successfully apply a correction for these effects. Using the three lens samples (the SDSS DR10 sample, the BCG sample and the SDSS-FIRST matched object sample), we measure a tangential shear signal that is inconsistent with 0 at the 10.2σ, 3.8σ and 9σ levels, respectively. Fitting an NFW model to the detected signals, we find that the ensemble mass profile of the BCG sample agrees with the values in the literature. However, the mass profiles of the SDSS DR10 and the SDSS-FIRST matched object samples are found to be shallower and steeper than results in the literature, respectively. The best-fitting Virial masses for the SDSS DR10, BCG and SDSS-FIRST matched samples, derived using an NFW model and allowing for a varying concentration factor, are M_{200}^SDSS-DR10 = (1.2 ± 0.4) × 10^{12} M_{⊙}, M_{200}^BCG = (1.4 ± 1.3) × 10^{13} M_{⊙} and M_{200}^SDSS-FIRST =8.0 ± 4.2 × 10^{13} M_{⊙}, respectively. These results are in good agreement (within ∼2σ) with values in the literature. Our findings suggest that for galaxies to be bright both in the radio and in the optical, they must be embedded in very dense environment on scales R ≲ 1 Mpc.

  3. A Survey of Star Clusters in the M31 South-West Field. UBVRI Photometry and Multi-Band Maps

    OpenAIRE

    Narbutis, D.; Vansevicius, V.; Kodaira, K.; Bridzius, A.; Stonkute, R.

    2008-01-01

    A new survey of star clusters in the South-West field of the M31 disk based on the high resolution Subaru Suprime-Cam observations is presented. The UBVRI aperture CCD photometry catalog of 285 objects (V < 20.5; 169 of them identified for the first time) is provided. Each object is supplemented with multi-band color maps presented in the electronic edition of the Astrophysical Journal Supplement. Seventy seven star cluster candidates from the catalog are located in the Hubble Space Telescope...

  4. The Sloan Digital Sky Survey-II Supernova Survey:Search Algorithm and Follow-up Observations

    Energy Technology Data Exchange (ETDEWEB)

    Sako, Masao; /Pennsylvania U. /KIPAC, Menlo Park; Bassett, Bruce; /Cape Town U. /South African Astron. Observ.; Becker, Andrew; /Washington U., Seattle, Astron. Dept.; Cinabro, David; /Wayne State U.; DeJongh, Don Frederic; /Fermilab; Depoy, D.L.; /Ohio State U.; Doi, Mamoru; /Tokyo U.; Garnavich, Peter M.; /Notre Dame U.; Craig, Hogan, J.; /Washington U., Seattle, Astron. Dept.; Holtzman, Jon; /New Mexico State U.; Jha, Saurabh; /Stanford U., Phys. Dept.; Konishi, Kohki; /Tokyo U.; Lampeitl, Hubert; /Baltimore, Space; Marriner, John; /Fermilab; Miknaitis, Gajus; /Fermilab; Nichol, Robert C.; /Portsmouth U.; Prieto, Jose Luis; /Ohio State U.; Richmond, Michael W.; /Rochester Inst.; Schneider, Donald P.; /Penn State U., Astron. Astrophys.; Smith, Mathew; /Portsmouth U.; SubbaRao, Mark; /Chicago U. /Tokyo U. /Tokyo U. /South African Astron. Observ. /Tokyo

    2007-09-14

    The Sloan Digital Sky Survey-II Supernova Survey has identified a large number of new transient sources in a 300 deg2 region along the celestial equator during its first two seasons of a three-season campaign. Multi-band (ugriz) light curves were measured for most of the sources, which include solar system objects, Galactic variable stars, active galactic nuclei, supernovae (SNe), and other astronomical transients. The imaging survey is augmented by an extensive spectroscopic follow-up program to identify SNe, measure their redshifts, and study the physical conditions of the explosions and their environment through spectroscopic diagnostics. During the survey, light curves are rapidly evaluated to provide an initial photometric type of the SNe, and a selected sample of sources are targeted for spectroscopic observations. In the first two seasons, 476 sources were selected for spectroscopic observations, of which 403 were identified as SNe. For the Type Ia SNe, the main driver for the Survey, our photometric typing and targeting efficiency is 90%. Only 6% of the photometric SN Ia candidates were spectroscopically classified as non-SN Ia instead, and the remaining 4% resulted in low signal-to-noise, unclassified spectra. This paper describes the search algorithm and the software, and the real-time processing of the SDSS imaging data. We also present the details of the supernova candidate selection procedures and strategies for follow-up spectroscopic and imaging observations of the discovered sources.

  5. Wide-Field Survey around Local Group Dwarf Spheroidal Galaxy Leo II: Spatial Distribution of Stellar Content

    Science.gov (United States)

    Komiyama, Yutaka; Doi, Mamoru; Furusawa, Hisanori; Hamabe, Masaru; Imi, Katsumi; Kimura, Masahiko; Miyazaki, Satoshi; Nakata, Fumiaki; Okada, Norio; Okamura, Sadanori; Ouchi, Masami; Sekiguchi, Maki; Shimasaku, Kazuhiro; Yagi, Masafumi; Yasuda, Naoki

    2007-08-01

    We carried out a wide-field V, I imaging survey of the Local Group dwarf spheroidal galaxy Leo II using the Subaru Prime Focus Camera on the 8.2 m Subaru Telescope. The survey covered an area of 26.67×26.67 arcmin2, far beyond the tidal radius of Leo II (8.63'), down to the limiting magnitude of V~=26, which is roughly 1 mag deeper than the turnoff point of the main-sequence stars of Leo II. Radial number density profiles of bright and faint red giant branch (RGB) stars were found to change their slopes at around the tidal radius, and extend beyond the tidal radius with shallower slopes. A smoothed surface brightness map of Leo II suggests the existence of a small substructure (4×2.5 arcmin2, 270×170 pc 2 in physical size) of globular cluster luminosity beyond the tidal radius. We investigated the properties of the stellar population by means of a color-magnitude diagram. The horizontal branch (HB) morphology index shows a radial gradient in which red HB stars are more concentrated than blue HB stars, which is common to many Local Group dwarf spheroidal galaxies. The color distribution of RGB stars around the mean RGB sequence shows a larger dispersion at the center than in the outskirts, indicating a mixture of stellar populations at the center and a more homogeneous population in the outskirts. Based on the age estimation using subgiant branch stars, we found that although the major star formation took place ~8 Gyr ago, a considerable stellar population younger than 8 Gyr is found at the center; such a younger population is insignificant in the outskirts. The following star formation history is suggested for Leo II. Star-forming activity occurred more than ~8 Gyr ago throughout the galaxy at a modest star formation rate. The star-forming region gradually shrank from the outside toward the center, and star-forming activity finally dropped to ~0 by ~4 Gyr ago, except for the center, where a small population younger than 4 Gyr is present. Based on data collected

  6. Mg II-Absorbing Galaxies in the UltraVISTA Survey

    Science.gov (United States)

    Stroupe, Darren; Lundgren, Britt

    2018-01-01

    Light that is emitted from distant quasars can become partially absorbed by intervening gaseous structures, including galaxies, in its path toward Earth, revealing information about the chemical content, degree of ionization, organization and evolution of these structures through time. In this project, quasar spectra are used to probe the halos of foreground galaxies at a mean redshift of z=1.1 in the COSMOS Field. Mg II absorption lines in Sloan Digital Sky Survey quasar spectra are paired with galaxies in the UltraVISTA catalog at an impact parameter less than 200 kpc. A sample of 77 strong Mg II absorbers with a rest-frame equivalent width ≥ 0.3 Å and redshift from 0.34 < z < 2.21 are investigated to find equivalent width ratios of Mg II, C IV and Fe II absorption lines, and their relation to the impact parameter and the star formation rates, stellar masses, environments and redshifts of their host galaxies.

  7. Self-assembly of high-nuclearity metal clusters: programmed expansion of a metallasiloxane cage to an octacopper(II) cluster.

    Science.gov (United States)

    Abbati, Gian Luca; Cornia, Andrea; Caneschi, Andrea; Fabretti, Antonio C; Mortalo, Cecilia

    2004-07-26

    The novel octanuclear copper(II) cluster [Cu6[(PhSiO2)6]2[NCCu(Me6tren)]2(MeOH)4]2+ (1) has been isolated as a perchlorate salt by reacting the hexacopper(II) metallasiloxane cage [Cu6[(PhSiO2)6]2(nBuOH)x] (x = 4, 6) with [Cu(Me6tren)CN]ClO4 in a methanol/chloroform mixture (Me6tren = tris(2-(dimethylamino)ethyl) amine). Crystal data for 1(ClO4)2 x MeOH: monoclinic, space group P2(1)/n (no. 14), a = 16.8490(3) angstroms, b = 22.2966(4) angstroms, c = 17.2508(3) angstroms, beta = 94.7658(5) degrees, V = 6458.3(2) angstroms3, Z = 2. The structure comprises a highly distorted hexagonal Cu6 array linked to two [Cu(Me6tren)] units via cyanide bridges. Magnetic measurements reveal that the addition of the copper cyanide complexes dramatically affects the magnetism of the Cu6 unit, whose ground spin state changes from S = 3 to S = 0. Copyright 2004 American Chemical Society

  8. Energy Efficient Hierarchical Clustering Approaches in Wireless Sensor Networks: A Survey

    Directory of Open Access Journals (Sweden)

    Bilal Jan

    2017-01-01

    Full Text Available Wireless sensor networks (WSN are one of the significant technologies due to their diverse applications such as health care monitoring, smart phones, military, disaster management, and other surveillance systems. Sensor nodes are usually deployed in large number that work independently in unattended harsh environments. Due to constraint resources, typically the scarce battery power, these wireless nodes are grouped into clusters for energy efficient communication. In clustering hierarchical schemes have achieved great interest for minimizing energy consumption. Hierarchical schemes are generally categorized as cluster-based and grid-based approaches. In cluster-based approaches, nodes are grouped into clusters, where a resourceful sensor node is nominated as a cluster head (CH while in grid-based approach the network is divided into confined virtual grids usually performed by the base station. This paper highlights and discusses the design challenges for cluster-based schemes, the important cluster formation parameters, and classification of hierarchical clustering protocols. Moreover, existing cluster-based and grid-based techniques are evaluated by considering certain parameters to help users in selecting appropriate technique. Furthermore, a detailed summary of these protocols is presented with their advantages, disadvantages, and applicability in particular cases.

  9. First-Year Sloan Digital Sky Survey-II (SDSS-II) Supernova Results: Constraints on Nonstandard Cosmological Models

    Science.gov (United States)

    Sollerman, J.; Mörtsell, E.; Davis, T. M.; Blomqvist, M.; Bassett, B.; Becker, A. C.; Cinabro, D.; Filippenko, A. V.; Foley, R. J.; Frieman, J.; Garnavich, P.; Lampeitl, H.; Marriner, J.; Miquel, R.; Nichol, R. C.; Richmond, M. W.; Sako, M.; Schneider, D. P.; Smith, M.; Vanderplas, J. T.; Wheeler, J. C.

    2009-10-01

    We use the new Type Ia supernovae discovered by the Sloan Digital Sky Survey-II supernova survey, together with additional supernova data sets as well as observations of the cosmic microwave background and baryon acoustic oscillations to constrain cosmological models. This complements the standard cosmology analysis presented by Kessler et al. in that we discuss and rank a number of the most popular nonstandard cosmology scenarios. When this combined data set is analyzed using the MLCS2k2 light-curve fitter, we find that more exotic models for cosmic acceleration provide a better fit to the data than the ΛCDM model. For example, the flat Dvali-Gabadadze-Porrati model is ranked higher by our information-criteria (IC) tests than the standard model with a flat universe and a cosmological constant. When the supernova data set is instead analyzed using the SALT-II light-curve fitter, the standard cosmological-constant model fares best. This investigation of how sensitive cosmological model selection is to assumptions about, and within, the light-curve fitters thereby highlights the need for an improved understanding of these unresolved systematic effects. Our investigation also includes inhomogeneous Lemaître-Tolman-Bondi (LTB) models. While our LTB models can be made to fit the supernova data as well as any other model, the extra parameters they require are not supported by our IC analysis. Finally, we explore more model-independent ways to investigate the cosmic expansion based on this new data set.

  10. Classification of patients based on their evaluation of hospital outcomes: cluster analysis following a national survey in Norway

    Science.gov (United States)

    2013-01-01

    Background A general trend towards positive patient-reported evaluations of hospitals could be taken as a sign that most patients form a homogeneous, reasonably pleased group, and consequently that there is little need for quality improvement. The objective of this study was to explore this assumption by identifying and statistically validating clusters of patients based on their evaluation of outcomes related to overall satisfaction, malpractice and benefit of treatment. Methods Data were collected using a national patient-experience survey of 61 hospitals in the 4 health regions in Norway during spring 2011. Postal questionnaires were mailed to 23,420 patients after their discharge from hospital. Cluster analysis was performed to identify response clusters of patients, based on their responses to single items about overall patient satisfaction, benefit of treatment and perception of malpractice. Results Cluster analysis identified six response groups, including one cluster with systematically poorer evaluation across outcomes (18.5% of patients) and one small outlier group (5.3%) with very poor scores across all outcomes. One-Way ANOVA with post-hoc tests showed that most differences between the six response groups on the three outcome items were significant. The response groups were significantly associated with nine patient-experience indicators (p questionnaire. Conclusions The study identified five response clusters with distinct patient-reported outcome scores, in addition to a heterogeneous outlier group with very poor scores across all outcomes. The outlier group and the cluster with systematically poorer evaluation across outcomes comprised almost one-quarter of all patients, clearly demonstrating the need to tailor quality initiatives and improve patient-perceived quality in hospitals. More research on patient clustering in patient evaluation is needed, as well as standardization of methodology to increase comparability across studies. PMID:23433450

  11. RESIS-II: An Updated Version of the Original Reservoir Sedimentation Survey Information System (RESIS) Database

    Science.gov (United States)

    Ackerman, Katherine V.; Mixon, David M.; Sundquist, Eric T.; Stallard, Robert F.; Schwarz, Gregory E.; Stewart, David W.

    2009-01-01

    The Reservoir Sedimentation Survey Information System (RESIS) database, originally compiled by the Soil Conservation Service (now the Natural Resources Conservation Service) in collaboration with the Texas Agricultural Experiment Station, is the most comprehensive compilation of data from reservoir sedimentation surveys throughout the conterminous United States (U.S.). The database is a cumulative historical archive that includes data from as early as 1755 and as late as 1993. The 1,823 reservoirs included in the database range in size from farm ponds to the largest U.S. reservoirs (such as Lake Mead). Results from 6,617 bathymetric surveys are available in the database. This Data Series provides an improved version of the original RESIS database, termed RESIS-II, and a report describing RESIS-II. The RESIS-II relational database is stored in Microsoft Access and includes more precise location coordinates for most of the reservoirs than the original database but excludes information on reservoir ownership. RESIS-II is anticipated to be a template for further improvements in the database.

  12. OCCASO - II. Physical parameters and Fe abundances of red clump stars in 18 open clusters

    Science.gov (United States)

    Casamiquela, L.; Carrera, R.; Blanco-Cuaresma, S.; Jordi, C.; Balaguer-Núñez, L.; Pancino, E.; Anders, F.; Chiappini, C.; Díaz-Pérez, L.; Aguado, D. S.; Aparicio, A.; Garcia-Dias, R.; Heiter, U.; Martínez-Vázquez, C. E.; Murabito, S.; del Pino, A.

    2017-10-01

    Open clusters have long been used to study the chemodynamical evolution of the Galactic disc. This requires a homogeneously analysed sample covering a wide range of ages and distances. In this paper, we present the Open Clusters Chemical Abundances from Spanish Observatories (OCCASO) second data release. This comprises a sample of high-resolution (R > 65 000) and high signal-to-noise spectra of 115 red clump stars in 18 open clusters. We derive atmospheric parameters (Teff, log g, ξ), and [Fe/H] abundances using two analysis techniques: equivalent widths and spectral synthesis. A detailed comparison and a critical review of the results of the two methods are made. Both methods are carefully tested between them, with the Gaia FGK benchmark stars, and with an extensive sample of literature values. We perform a membership study using radial velocities and the resulting abundances. Finally, we compare our results with a chemodynamical model of the Milky Way thin disc concluding that the oldest open clusters are consistent with the models only when dynamical effects are taken into account.

  13. Evolution of stellar collision products in open clusters : II. A grid of low-mass collisions

    NARCIS (Netherlands)

    Glebbeek, E.|info:eu-repo/dai/nl/30483324X; Pols, O.R.|info:eu-repo/dai/nl/111811155

    2008-01-01

    In a companion paper we studied the detailed evolution of stellar collision products that occurred in an N-body simulation of the old open cluster M 67 and compared our detailed models to simple prescriptions. In this paper we extend this work by studying the evolution of the collision products in

  14. ISO far-infrared observations of rich galaxy clusters II. Sersic 159-03

    DEFF Research Database (Denmark)

    Hansen, Lene; Jørgensen, H.E.; Nørgaard-Nielsen, Hans Ulrik

    2000-01-01

    In a series of papers we investigate far-infrared emission from rich galaxy clusters. Maps have been obtained by ISO at 60 mu m, 100 mu m, 135 mu m, and 200 mu m using the PHT-C camera. Ground based imaging and spectroscopy were also acquired. Here we present the results for the cooling flow...

  15. Burns in Baghdad from 2003–2014: results of a randomized household cluster survey

    Science.gov (United States)

    Stewart, Barclay T; Lafta, Riyadh; Shatari, Sahar A Esa Al; Cherewick, Megan; Burnham, Gilbert; Hagopian, Amy; Galway, Lindsay P; Kushner, Adam L

    2015-01-01

    Purpose Civilians living amid conflict are at high-risk of burns. However, the epidemiology of burns among this vulnerable group is poorly understood, yet vital for health policy and relief planning. To address this gap, we aimed to determine the death and disability, healthcare needs and household financial consequences of burns in post-invasion Baghdad. Methods A two-stage, cluster randomized, community-based household survey was performed in May of 2014 to determine the civilian burden of injury from 2003 to 2014 in Baghdad. In addition to questions about cause of household member death, households were interviewed regarding burn specifics, healthcare required, disability, relationship to conflict and resultant financial hardship. Results Nine-hundred households, totaling 5,148 individuals, were interviewed. There were 55 burns, which were 10% of all injuries reported. There were an estimated 2,340 serious burn injures (39 per 100,000 persons) in Baghdad in 2003. The frequency of serious burn injuries generally increased post-invasion to 8,780 burns in 2013 (117 per 100,000 persons). Eight burns (15%) were the direct result of conflict. Individuals aged over 45 years had more than twice the odds of burn injury than children aged less than 13 years (aOR 2.42; 95%CI 1.08 – 5.44). Nineteen burns (35%) involved ≥20% body surface area. Death (16% of burn injuries), disability (40%), household financial hardship (48%) and food insecurity (50%) were common after burn injury. Conclusion Civilian burn injury in Baghdad is epidemic, increasing in frequency and associated with household financial hardship. Challenges of healthcare provision during prolonged conflict were evidenced by a high mortality rate and likelihood of disability after burn injury. Ongoing conflict will directly and indirectly generate more burns, which mandates planning for burn prevention and care within local capacity development initiatives, as well as humanitarian assistance. PMID:26526376

  16. Burns in Baghdad from 2003 to 2014: Results of a randomized household cluster survey.

    Science.gov (United States)

    Stewart, Barclay T; Lafta, Riyadh; Esa Al Shatari, Sahar A; Cherewick, Megan; Burnham, Gilbert; Hagopian, Amy; Galway, Lindsay P; Kushner, Adam L

    2016-02-01

    Civilians living amid conflict are at high-risk of burns. However, the epidemiology of burns among this vulnerable group is poorly understood, yet vital for health policy and relief planning. To address this gap, we aimed to determine the death and disability, healthcare needs and household financial consequences of burns in post-invasion Baghdad. A two-stage, cluster randomized, community-based household survey was performed in May 2014 to determine the civilian burden of injury from 2003 to 2014 in Baghdad. In addition to questions about cause of household member death, households were interviewed regarding burn specifics, healthcare required, disability, relationship to conflict and resultant financial hardship. Nine-hundred households, totaling 5148 individuals, were interviewed. There were 55 burns, which were 10% of all injuries reported. There were an estimated 2340 serious burns (39 per 100,000 persons) in Baghdad in 2003. The frequency of serious burns generally increased post-invasion to 8780 burns in 2013 (117 per 100,000 persons). Eight burns (15%) were the direct result of conflict. Individuals aged over 45 years had more than twice the odds of burn than children aged less than 13 years (aOR 2.42; 95%CI 1.08-5.44). Nineteen burns (35%) involved ≥ 20% body surface area. Death (16% of burns), disability (40%), household financial hardship (48%) and food insecurity (50%) were common after burn. Civilian burn in Baghdad is epidemic, increasing in frequency and associated with household financial hardship. Challenges of healthcare provision during prolonged conflict were evidenced by a high mortality rate and likelihood of disability after burn. Ongoing conflict will directly and indirectly generates more burns, which mandates planning for burn prevention and care within local capacity development initiatives, as well as humanitarian assistance. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

  17. Socioeconomic-related inequalities in child malnutrition: evidence from the Ghana multiple indicator cluster survey.

    Science.gov (United States)

    Novignon, Jacob; Aboagye, Emmanuel; Agyemang, Otuo Serebour; Aryeetey, Genevieve

    2015-12-01

    Malnutrition is a prevalent public health concern in Ghana. While studies have identified factors that influence child malnutrition and related inequalities in Ghana, very little efforts have been made to decompose these inequalities across various household characteristics. This study examined the influence of socioeconomic factors on inequality in child malnutrition using a decomposition approach. The study employed cross section data from the 2011 Multiple Indicator Cluster Survey (MICS). Analysis was done at three levels: First, concentration curves were constructed to explore the nature of inequality in child malnutrition. Secondly, concentration indices were computed to quantify the magnitude of inequality. Thirdly, decomposition analysis was conducted to determine the role of mother's education and health insurance coverage in inequality of child malnutrition. The concentration curves showed that there exists a pro-poor inequality in child malnutrition measured by stunting and wasting. The concentration indices of these measures indicated that the magnitude of inequality was higher and significant at 1 % for weight-for-age (WAZ) (-0.1641), relative to height-for-age (HAZ) (-0.1613). The decomposition analyses show that whilst mother's education contributed about 13 and 11 % to inequality in HAZ, it contributed about 18.9 and 11.8 % to inequality in WAZ for primary and secondary or above education attainments, respectively. Finally, health insurance contributed about 1.91 and 1.03 % to inequality in HAZ and WAZ, respectively. The results suggest that there is the need to encourage critical policies directed towards improving female literacy in the country. The existence of a functional health insurance system and increasing universal coverage are recommended to mitigate child malnutrition.

  18. An Analysis of Rich Cluster Redshift Survey Data for Large Scale Structure Studies

    Science.gov (United States)

    Slinglend, K.; Batuski, D.; Haase, S.; Hill, J.

    1994-12-01

    The results from the COBE satellite show the existence of structure on scales on the order of 10% or more of the horizon scale of the universe. Rich clusters of galaxies from Abell's catalog show evidence of structure on scales of 100 Mpc and may hold the promise of confirming structure on the scale of the COBE result. However, many Abell clusters have zero or only one measured redshift, so present knowledge of their three dimensional distribution has quite large uncertainties. The shortage of measured redshifts for these clusters may also mask a problem of projection effects corrupting the membership counts for the clusters. Our approach in this effort has been to use the MX multifiber spectrometer on the Steward 2.3m to measure redshifts of at least ten galaxies in each of 80 Abell cluster fields with richness class R>= 1 and mag10 <= 16.8 (estimated z<= 0.12) and zero or one measured redshifts. This work will result in a deeper, more complete (and reliable) sample of positions of rich clusters. Our primary intent for the sample is for two-point correlation and other studies of the large scale structure traced by these clusters in an effort to constrain theoretical models for structure formation. We are also obtaining enough redshifts per cluster so that a much better sample of reliable cluster velocity dispersions will be available for other studies of cluster properties. To date, we have collected such data for 64 clusters, and for most of them, we have seven or more cluster members with redshifts, allowing for reliable velocity dispersion calculations. Velocity histograms and stripe density plots for several interesting cluster fields are presented, along with summary tables of cluster redshift results. Also, with 10 or more redshifts in most of our cluster fields (30({') } square, just about an `Abell diameter' at z ~ 0.1) we have investigated the extent of projection effects within the Abell catalog in an effort to quantify and understand how this may effect

  19. Patient evaluation of hospital outcomes: an analysis of open-ended comments from extreme clusters in a national survey

    OpenAIRE

    Iversen, Hilde Hestad; Bjertnæs, Øyvind Andresen; Skudal, Kjersti Eeg

    2014-01-01

    Objectives A recent study identified patients in six distinct response groups based on their evaluations of outcomes related to overall satisfaction, malpractice and benefit of treatment. This study validates the response clusters by analysing and comparing open-ended comments from the extreme positive and extreme negative response groups. Design Qualitative content analysis. Setting Data from open-ended comment fields provided by patients who completed a national patient-experience survey ca...

  20. Synthesis of mixed-valence hexanuclear Mn(II/III) clusters from its Mn(II) precursor: variations of catecholase-like activity and magnetic coupling.

    Science.gov (United States)

    Kar, Paramita; Ida, Yumi; Kanetomo, Takuya; Drew, Michael G B; Ishida, Takayuki; Ghosh, Ashutosh

    2015-06-07

    One Mn(II) coordination polymer, [Mn(o-(NO2)C6H4COO)2(pyz)(H2O)]n (1), has been synthesized and oxidized with n-Bu4NMnO4 in non-aqueous media to two mixed-valence hexanuclear Mn(II/III) complexes [MnIII2MnII4O2(pyz)0.61/(MeOH)0.39(o-(NO2)C6H4COO)10·(H2O)·{(CH3)2CO}2]·(CH3)2CO (2) and [MnIII2MnII4O2(pyz)0.28/(MeCN)3.72(o-(NO2)C6H4COO)10·(H2O)] (3) (where pyz = pyrazine). All three complexes were characterized by elemental analyses, IR spectroscopy, single-crystal X-ray diffraction analyses, and variable-temperature magnetic measurements. The structural analyses reveal that complex 1 is comprised of linear chains of pyz bridged Mn(II), which are further linked to one another by syn–anti carboxylate bridges, giving rise to a two-dimensional (2D) net. Complexes 2 and 3 feature mixed valence [MnIII2MnII4] units in which each of the six manganese centres reside in an octahedral environment. Apart from the variations in terminal ligands (acetone for 2 and acetonitrile for 3), the complexes are very similar. Using 3,5-di-tert-butyl catechol (3,5-DTBC) as the substrate, the catecholase-like activity of the complexes has been studied and it is found that the mixed valent Mn6 complexes (2 and 3) are much more active towards aerial oxidation of catechol compared to the Mn(II) complex (1). Variable-temperature (1.8–300 K) magnetic susceptibility measurements showed the presence of antiferromagnetic coupling in all three complexes. The magnetic data have been fitted with a 2D quadratic model derived by Lines, giving the exchange constant J/kB = −0.0788(5) K for 1. For 2 and 3, antiferromagnetic interactions within the Mn6 cluster have been fitted with models containing three exchange constants: JA/kB = −70 K, JB/kB = −0.5 K, JC/kB = −2.9 K for 2 and JA/kB = −60 K, JB/kB = −0.3 K, JC/kB = −2.8 K for 3.

  1. A survey on the taxonomy of cluster-based routing protocols for homogeneous wireless sensor networks.

    Science.gov (United States)

    Naeimi, Soroush; Ghafghazi, Hamidreza; Chow, Chee-Onn; Ishii, Hiroshi

    2012-01-01

    The past few years have witnessed increased interest among researchers in cluster-based protocols for homogeneous networks because of their better scalability and higher energy efficiency than other routing protocols. Given the limited capabilities of sensor nodes in terms of energy resources, processing and communication range, the cluster-based protocols should be compatible with these constraints in either the setup state or steady data transmission state. With focus on these constraints, we classify routing protocols according to their objectives and methods towards addressing the shortcomings of clustering process on each stage of cluster head selection, cluster formation, data aggregation and data communication. We summarize the techniques and methods used in these categories, while the weakness and strength of each protocol is pointed out in details. Furthermore, taxonomy of the protocols in each phase is given to provide a deeper understanding of current clustering approaches. Ultimately based on the existing research, a summary of the issues and solutions of the attributes and characteristics of clustering approaches and some open research areas in cluster-based routing protocols that can be further pursued are provided.

  2. A Survey on the Taxonomy of Cluster-Based Routing Protocols for Homogeneous Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Hiroshi Ishii

    2012-05-01

    Full Text Available The past few years have witnessed increased interest among researchers in cluster-based protocols for homogeneous networks because of their better scalability and higher energy efficiency than other routing protocols. Given the limited capabilities of sensor nodes in terms of energy resources, processing and communication range, the cluster-based protocols should be compatible with these constraints in either the setup state or steady data transmission state. With focus on these constraints, we classify routing protocols according to their objectives and methods towards addressing the shortcomings of clustering process on each stage of cluster head selection, cluster formation, data aggregation and data communication. We summarize the techniques and methods used in these categories, while the weakness and strength of each protocol is pointed out in details. Furthermore, taxonomy of the protocols in each phase is given to provide a deeper understanding of current clustering approaches. Ultimately based on the existing research, a summary of the issues and solutions of the attributes and characteristics of clustering approaches and some open research areas in cluster-based routing protocols that can be further pursued are provided.

  3. Segmenting Business Students Using Cluster Analysis Applied to Student Satisfaction Survey Results

    Science.gov (United States)

    Gibson, Allen

    2009-01-01

    This paper demonstrates a new application of cluster analysis to segment business school students according to their degree of satisfaction with various aspects of the academic program. The resulting clusters provide additional insight into drivers of student satisfaction that are not evident from analysis of the responses of the student body as a…

  4. Rail and multimodal freight: a problem-oriented survey (part II-2

    Directory of Open Access Journals (Sweden)

    Marin MARINOV

    2009-01-01

    Full Text Available This paper includes the Part II-2 of the series of problem-oriented surveys on rail and multimodal freight transportation services, which aim is to reveal the current situation in this sector and raises looming questions for discussion. The particular objective of Part II-2 is to discuss recently published works and documents dedicated to Multi-actor chain management and control, Mode choice and pricing strategies, Intermodal transportation policy and planning as well as Miscellaneous. It should be noted that this paper is a problem oriented survey and does not explicitly focus on the available scientific instrumental that has been applied in dealing with rail and multimodal freight. However, throughout the description methods and concepts are addressed, where it is of interest.

  5. HICOSMO: cosmology with a complete sample of galaxy clusters - II. Cosmological results

    Science.gov (United States)

    Schellenberger, G.; Reiprich, T. H.

    2017-10-01

    The X-ray bright, hot gas in the potential well of a galaxy cluster enables systematic X-ray studies of samples of galaxy clusters to constrain cosmological parameters. HIFLUGCS consists of the 64 X-ray brightest galaxy clusters in the Universe, building up a local sample. Here, we utilize this sample to determine, for the first time, individual hydrostatic mass estimates for all the clusters of the sample and, by making use of the completeness of the sample, we quantify constraints on the two interesting cosmological parameters, Ωm and σ8. We apply our total hydrostatic and gas mass estimates from the X-ray analysis to a Bayesian cosmological likelihood analysis and leave several parameters free to be constrained. We find Ωm = 0.30 ± 0.01 and σ8 = 0.79 ± 0.03 (statistical uncertainties, 68 per cent credibility level) using our default analysis strategy combining both a mass function analysis and the gas mass fraction results. The main sources of biases that we correct here are (1) the influence of galaxy groups (incompleteness in parent samples and differing behaviour of the Lx-M relation), (2) the hydrostatic mass bias, (3) the extrapolation of the total mass (comparing various methods), (4) the theoretical halo mass function and (5) other physical effects (non-negligible neutrino mass). We find that galaxy groups introduce a strong bias, since their number density seems to be over predicted by the halo mass function. On the other hand, incorporating baryonic effects does not result in a significant change in the constraints. The total (uncorrected) systematic uncertainties (∼20 per cent) clearly dominate the statistical uncertainties on cosmological parameters for our sample.

  6. Testing lowered isothermal models with direct N-body simulations of globular clusters - II. Multimass models

    Science.gov (United States)

    Peuten, M.; Zocchi, A.; Gieles, M.; Hénault-Brunet, V.

    2017-09-01

    Lowered isothermal models, such as the multimass Michie-King models, have been successful in describing observational data of globular clusters. In this study, we assess whether such models are able to describe the phase space properties of evolutionary N-body models. We compare the multimass models as implemented in limepy (Gieles & Zocchi) to N-body models of star clusters with different retention fractions for the black holes and neutron stars evolving in a tidal field. We find that multimass models successfully reproduce the density and velocity dispersion profiles of the different mass components in all evolutionary phases and for different remnants retention. We further use these results to study the evolution of global model parameters. We find that over the lifetime of clusters, radial anisotropy gradually evolves from the low- to the high-mass components and we identify features in the properties of observable stars that are indicative of the presence of stellar-mass black holes. We find that the model velocity scale depends on mass as m-δ, with δ ≃ 0.5 for almost all models, but the dependence of central velocity dispersion on m can be shallower, depending on the dark remnant content, and agrees well with that of the N-body models. The reported model parameters, and correlations amongst them, can be used as theoretical priors when fitting these types of mass models to observational data.

  7. X-ray studies of coeval star samples. II - The Pleiades cluster as observed with the Einstein Observatory

    Science.gov (United States)

    Micela, G.; Sciortino, S.; Vaiana, G. S.; Harnden, F. R., Jr.; Rosner, R.

    1990-01-01

    Coronal X-ray emission of the Pleiades stars is investigated, and maximum likelihood, integral X-ray luminosity functions are computed for Pleiades members in selected color-index ranges. A detailed search is conducted for long-term variability in the X-ray emission of those stars observed more than once. An overall comparison of the survey results with those of previous surveys confirms the ubiquity of X-ray emission in the Pleiades cluster stars and its higher rate of emission with respect to older stars. It is found that the X-ray emission from dA and early dF stars cannot be proven to be dissimilar to that of Hyades and field stars of the same spectral type. The Pleiades cluster members show a real rise of the X-ray luminosity from dA stars to early dF stars. X-ray emission for the young, solarlike Pleiades stars is about two orders of magnitude more intense than for the nearby solarlike stars.

  8. Synthesis, structure characterization, DNA binding, and cleavage properties of mononuclear and tetranuclear cluster of copper(II) complexes.

    Science.gov (United States)

    Vafazadeh, Rasoul; Hasanzade, Naime; Heidari, Mohammad Mehdi; Willis, Anthony C

    2015-01-01

    Two copper(II) complexes, cluster 1, and mononuclear 2, have been synthesized by reacting acetylacetone and benzohydrazide (1:1 ratio for 1 and 1:2 ratio for 2) with CuCl(2) in a methanol solution. In 2, which is a new complex, the ligand acts as a tetradentate which binds the metal ion via two amide-O atoms and two imine-N atoms providing an N(2)O(2) square-planar around the copper(II) ion. The absorption spectra data evidence strongly suggested that the two copper(II) compounds could interact with CT-DNA (intrinsic binding constant, K(b) = 0.45×10(4) M-1 for 1 and K(b) = 2.39×10(4) M-1 for 2). The super coiled plasmid pBR322 DNA cleavage ability was studied with 1 and 2 in the presence and absence of H(2)O(2) as an oxidant. In both the absence and the presence of an oxidizing agent, complex 2 exhibited no nuclease activity. However, even in the absence of an oxidant, complex 1 exhibited significant DNA cleavage activity.

  9. Fall injuries in Baghdad from 2003 to 2014: results of a randomized household cluster survey

    Science.gov (United States)

    Stewart, Barclay T; Lafta, Riyadh; Shatari, Sahar A Esa Al; Cherewick, Megan; Flaxman, Abraham; Hagopian, Amy; Burnham, Gilbert; Kushner, Adam L

    2015-01-01

    Introduction Falls incur nearly 35 million disability-adjusted life-years annually; 75% of which occur in low- and middle-income countries. The epidemiology of civilian injuries during conflict is relatively unknown, yet important for planning prevention initiatives, health policy and humanitarian assistance. This study aimed to determine the death and disability and household consequences of fall injuries in post-invasion Baghdad. Methods A two-stage, cluster randomized, community-based household survey was performed in May of 2014 to determine the civilian burden of injury from 2003 to 2014 in Baghdad. In addition to questions about household member death, households were interviewed regarding injury specifics, healthcare required, disability, relatedness to conflict and resultant financial hardship. Results Nine hundred households totaling 5,148 individuals were interviewed. There were 138 fall injuries (25% of all injuries reported); fall was the most common mechanism of civilian injury in Baghdad. The rate of serious fall injuries increased from 78 to 466 per 100,000 persons in 2003 and 2013, respectively. Fall was the most common mechanism among the injured elderly (i.e. ≥65 years; 15/24 elderly unintentional injuries; 63%). However, 46 fall injuries were children aged injuries) and 77 were respondents aged 15 - 64 years (36%). Respondents who spent significant time within the home (i.e. unemployed, retired, homemaker) had three times greater odds of having suffered a fall injury than student referents (aOR 3.34; 95%CI 1.30 – 8.60). Almost 80% of fall injured were left with life-limiting disability. Affected households often borrowed substantial sums of money (34 households; 30% of affected households) and/or suffered food insecurity after a family member's fall (52; 46%). Conclusion Falls were the most common cause of civilian injury in Baghdad. In part due to the effect of prolonged insecurity on a fragile health system, many injuries resulted in life

  10. NEWLY IDENTIFIED EXTENDED GREEN OBJECTS (EGOs) FROM THE SPITZER GLIMPSE II SURVEY. I. CATALOG

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xi; Gan, Cong-Gui; Shen, Zhi-Qiang [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030 (China); Ellingsen, Simon P.; Titmarsh, Anita [School of Mathematics and Physics, University of Tasmania, Hobart, Tasmania (Australia); He, Jin-Hua, E-mail: chenxi@shao.ac.cn [Key Laboratory for the Structure and Evolution of Celestial Objects, Yunnan Astronomical Observatory/National Astronomical Observatory, Chinese Academy of Sciences, P.O. Box 110, Kunming, 650011 Yunnan Province (China)

    2013-05-01

    We have produced a catalog containing 98 newly identified massive young stellar object (MYSO) candidates associated with ongoing outflows (known as extended green objects, or EGOs). These have been identified from the Spitzer Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) II data set and our new identifications increase the number of known EGOs to {approx}400 in our Galaxy, adding to the {approx}300 previously identified EGOs reported by Cyganowski et al. from the GLIMPSE I survey. The high detection rate ({approx}70%) of 95 GHz class I methanol masers achieved in a survey toward 57 of these new EGOs with the Mopra 22 m radio telescope demonstrates that the new EGOs are associated with outflows. Investigations of the mid-infrared properties and physical associations with other star formation tracers (e.g., infrared dark clouds, class I and II methanol masers, and millimeter Bolocam Galactic Plane Survey sources) reveal that the newly identified EGOs are very similar in nature to those in the sample of Cyganowski et al. All of the observational evidence supports the hypothesis that EGOs correspond to MYSOs at the earliest evolutionary stage, with ongoing outflow activity, and active rapid accretion.

  11. Self-Consistency and Calibration of Cluster Number Count Surveys for Dark Energy

    OpenAIRE

    Hu, Wayne

    2003-01-01

    Cluster number counts offer sensitive probes of the dark energy if and only if the_evolution_ of the cluster mass versus observable relation(s) is well calibrated. We investigate the potential for internal calibration by demanding consistency in the counts as a function of the observable. In the context of a constant dark energy equation of state, known initial fluctuation amplitude expected from the CMB, universal underlying mass function, and an idealized selection, we find that the ambigui...

  12. Star Clusters in Tidal Debris: A UV Survey of Stellar Populations, Galaxy Interactions, and Evolution

    Science.gov (United States)

    Rodruck, Michael

    2017-08-01

    Tidal tails afford us a unique window into the processes shaping star formation, offering an unobstructed view of the star formation environment in these outskirts. The latest galactic merger simulations are finding an unexpected increase of star formation in extended tidal debris, with 20 - 50% of the systems star formation rate occurring in these regions. We see this observationally in massive clusters forming in the Tadpole galaxy, occupying 30% of the system's star formation rate. At the same time, clusters suffer high rates of disruption, dispersing their material into the diffuse light of the tail and mixing with old stars drawn from the parent galaxies. We intend to break our tidal tails into their composite populations using HST and ground-based Gemini imaging. Our existing WFPC2 VI-band and HI data indicate clusters prefer to live in regions of high HI kinetic energy and low shear. However, analysis is limited to population studies, as the lack of UB-band data prevents us from age or mass estimates, permitting only a shallow understanding of the relationship between local HI properties and star clusters. Additionally, while the high resolution of HST is necessary for identifying and studying star clusters, it is unsuitable for the sensitive imaging needed to study the faint, diffuse tails. Our proposed 11 orbits of WFC3/ACS UB-band imaging will allow for precise age and mass measurements of our star clusters, while ground-based imaging searches the diffuse light for the cluster destruction history. In this manner, we will determine the present and past history of star formation in tidal tails, and the HI densities and kinematics required for cluster formation.

  13. Optical spectroscopy and velocity dispersions of galaxy clusters from the SPT-SZ survey

    Energy Technology Data Exchange (ETDEWEB)

    Ruel, J.; Bayliss, M. [Department of Physics, Harvard University, 17 Oxford Street, Cambridge, MA 02138 (United States); Bazin, G.; Bocquet, S. [Department of Physics, Ludwig-Maximilians-Universität, Scheinerstr. 1, 81679 München (Germany); Brodwin, M. [Department of Physics and Astronomy, University of Missouri, 5110 Rockhill Road, Kansas City, MO 64110 (United States); Foley, R. J.; Stalder, B.; Ashby, M. L. N. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Aird, K. A. [University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Armstrong, R. [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104 (United States); Bautz, M. [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Benson, B. A.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Crawford, T. M.; Crites, A. T. [Kavli Institute for Cosmological Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Chapman, S. C. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Cho, H. M. [NIST Quantum Devices Group, 325 Broadway Mailcode 817.03, Boulder, CO 80305 (United States); Clocchiatti, A., E-mail: mbayliss@cfa.harvard.edu [Instituto de Astrofisica, Pontificia Universidad Catolica (Chile); and others

    2014-09-01

    We present optical spectroscopy of galaxies in clusters detected through the Sunyaev-Zel'dovich (SZ) effect with the South Pole Telescope (SPT). We report our own measurements of 61 spectroscopic cluster redshifts, and 48 velocity dispersions each calculated with more than 15 member galaxies. This catalog also includes 19 dispersions of SPT-observed clusters previously reported in the literature. The majority of the clusters in this paper are SPT-discovered; of these, most have been previously reported in other SPT cluster catalogs, and five are reported here as SPT discoveries for the first time. By performing a resampling analysis of galaxy velocities, we find that unbiased velocity dispersions can be obtained from a relatively small number of member galaxies (≲ 30), but with increased systematic scatter. We use this analysis to determine statistical confidence intervals that include the effect of membership selection. We fit scaling relations between the observed cluster velocity dispersions and mass estimates from SZ and X-ray observables. In both cases, the results are consistent with the scaling relation between velocity dispersion and mass expected from dark-matter simulations. We measure a ∼30% log-normal scatter in dispersion at fixed mass, and a ∼10% offset in the normalization of the dispersion-mass relation when compared to the expectation from simulations, which is within the expected level of systematic uncertainty.

  14. Novel mixed-valence manganese cluster with two distinct Mn3(II/III/II) and Mn3(III/II/III) trinuclear units in a pseudocubane-like arrangement.

    Science.gov (United States)

    Dimitrakopoulou, Anastasia; Psycharis, Vassilis; Raptopoulou, Catherine P; Terzis, Aris; Tangoulis, Vassilis; Kessissoglou, Dimitris P

    2008-09-01

    The reaction between Mn(ClO 4) 2 and di-(2-pyridyl)-ketone in the presence of the sodium salt of propanediol as a base in MeOH leads to the formation of a hexanuclear manganese cluster. This cluster has been characterized by the formula [Mn(II) 3Mn(III) 3O(OH)(CH 3pdol) 3(Hpdol) 3(pdol)](ClO 4) 4 ( 1). Molecular conductance measurements of a 10 (-3) M solution of compound 1 in CH 3CN, DMSO, or DMF give Lambda m = 529, 135, or 245 muS/cm, respectively, which suggests a 1:4 cation/anion electrolyte. The crystal structure of hexanuclear manganese cluster 1 consists of two distinct trinuclear units with a pseudocubane-like arrangement. The trinuclear units show two different valence distributions, Mn(II)/Mn(III)/Mn(II) and Mn(III)/Mn(II)/Mn(III). Additional features of interest for the compound include the fact that (a) two of the Mn(III) ions show a Jahn-Teller elongation, whereas the third ion shows a Jahn-Teller compression; (b) one bridge between Mn(III) atoms is an oxo (O (2-)) ion, whereas the bridge between Mn(II) and Mn(III) is a hydroxyl (OH (-)) group; and (c) the di-(2-pyridyl)-ketone ligand that is methanolyzed to methyl-Hpdol and R 2pdol (R = CH 3, H) acts in three different modes: methyl-pdol(-1), Hpdol(-1), and pdol(-2). For magnetic behavior, the general Hamiltonian formalism considers that (a) all of the interactions inside the two "cubanes" between Mn(II) and Mn(III) ions are equal to the J 1 constant, those between Mn(II) ions are equal to the J 2 constant, and those between the Mn(III) ions are equal to the J 3 constant and (b) the interaction between the two cubanes is equal to the J 4 constant. The fitting results are J 1 = J 2 = 0.7 cm (-1), J 3 approximately 0.0, J 4 = -6.2 cm (-1), and g = 2.0 (fixed). According to these results, the ground state is S = 1/2, and the next excited states are S = 3/2 and 5/2 at 0.7 and 1.8 cm (-1), respectively. The EPR spectra prove that the spin ground state at a low temperature is not purely S = 1/2 but is

  15. Patient evaluation of hospital outcomes: an analysis of open-ended comments from extreme clusters in a national survey.

    Science.gov (United States)

    Iversen, Hilde Hestad; Bjertnæs, Oyvind Andresen; Skudal, Kjersti Eeg

    2014-05-30

    A recent study identified patients in six distinct response groups based on their evaluations of outcomes related to overall satisfaction, malpractice and benefit of treatment. This study validates the response clusters by analysing and comparing open-ended comments from the extreme positive and extreme negative response groups. Qualitative content analysis. Data from open-ended comment fields provided by patients who completed a national patient-experience survey carried out in Norway in 2011. 10 514 patients responded to the questionnaire and 3233 provided comments. A random sample of 50 open-ended comments from respondents representing cluster 1 ('excellent services'), cluster 5 ('services have clear improvement needs') and outliers ('very poor services') was reviewed. 3 distinct patient profiles were identified. More than half of the comments in cluster 1 included descriptions of positive healthcare experiences, one addressed patient safety issues. Only 1 of the comments in cluster 5 was positive, and 12 were related to safety. All comments from the outliers were negative, and more than three-quarters reported experiences related to malpractice or adverse events. Recurring themes did not differ significantly between the three respondent groups, but significant differences were found for the descriptions and severity of the experiences. Patients in negative response groups had distinct and much poorer healthcare descriptions than those in the extreme positive group, supporting the interpretation of quality differences between these groups. Further research should assess ways of combining statistical cluster information and qualitative comments, which could be used for local quality improvement and public reporting. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  16. Virgo Cluster and field dwarf ellipticals in 3D - II. Internal dynamics points to tidal harassment?

    Science.gov (United States)

    Ryś, A.; van de Ven, G.; Falcón-Barroso, J.

    2014-03-01

    We present the dynamical analysis of a sample of 12 dwarf elliptical (dE) galaxies for which we have obtained SAURON large-scale two-dimensional spectroscopic data. We construct Jeans axisymmetric models and obtain total dynamical masses enclosed within one effective radius. We use the obtained values to show that the validity of the dynamical scaling relations of massive early-type galaxies can be extended to these low-mass systems, except that dEs seem to contain relatively larger fraction of dark matter in their inner parts. We then demonstrate that dE galaxies have lower angular momenta than the present-day analogues of their presumed late-type progenitors, and we show that dE circular velocity curves are steeper than the rotation curves of galaxies with equal and up to an order of magnitude higher luminosity. This requires a transformation mechanism that is not only able to lower the angular momentum but also one that needs to account for increased stellar concentration. Additionally, we match the dark matter fraction of our galaxies to their location in the Virgo Cluster and see that galaxies in the cluster outskirts tend to have a higher dark-to-stellar matter ratio. Transformation due to tidal harassment is able to explain all of the above, unless the dE progenitors were already compact and had lower angular momenta at higher redshifts.

  17. VizieR Online Data Catalog: On the metallicity of open clusters. II. (Heiter+, 2014)

    Science.gov (United States)

    Heiter, U.; Soubiran, C.; Netopil, M.; Paunzen, E.

    2013-11-01

    In Table 1 we list the basic information for each star and each metallicity determination in the starting sample, which should be sufficient to extract the corresponding atmospheric parameters from the PASTEL catalogue. Table 4 lists the weighted mean metallicities for each OC and each paper, which were computed using the metallicities from the references in Table 1. For the weights we used the inverse square of the individual errors quoted by the authors. Table 4 also gives the ranges of effective temperature (Teff) and surface gravity (logg) of the stars corresponding to each paper. After removing all determinations with Teff outside the range 4400 to 6500K and with logg<2.0, we constructed a list of recommended cluster metallicities, which we call the final high-resolution sample. The weighted mean metallicities for each cluster in the final sample are given in Table 11, and the individual determinations included in the final sample are identified in Table 1 (first column). (3 data files).

  18. CHANDRA OBSERVATIONS OF 3C RADIO SOURCES WITH z < 0.3. II. COMPLETING THE SNAPSHOT SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Massaro, F. [SLAC National Laboratory and Kavli Institute for Particle Astrophysics and Cosmology, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Tremblay, G. R. [European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching bei Muenchen (Germany); Harris, D. E.; O' Dea, C. P. [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Kharb, P.; Axon, D. [Department of Physics, Rochester Institute of Technology, Carlson Center for Imaging Science 76-3144, 84 Lomb Memorial Dr., Rochester, NY 14623 (United States); Balmaverde, B.; Capetti, A. [INAF-Osservatorio Astrofisico di Torino, Strada Osservatorio 20, I-10025 Pino Torinese (Italy); Baum, S. A. [Carlson Center for Imaging Science 76-3144, 84 Lomb Memorial Dr., Rochester, NY 14623 (United States); Chiaberge, M.; Macchetto, F. D.; Sparks, W. [Space Telescope Science Institute, 3700 San Martine Drive, Baltimore, MD 21218 (United States); Gilli, R. [INAF-Osservatorio Astronomico di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); Giovannini, G. [INAF-Istituto di Radioastronomia di Bologna, Via Gobetti 101, I-40129 Bologna (Italy); Grandi, P.; Torresi, E. [INAF-IASF-Istituto di Astrofisica Spaziale e fisica Cosmica di Bologna, Via P. Gobetti 101, I-40129 Bologna (Italy); Risaliti, G. [INAF-Osservatorio Astronomico di Arcetri, Largo E. Fermi 5, I-50125 Firenze (Italy)

    2012-12-15

    We report on the second round of Chandra observations of the 3C snapshot survey developed to observe the complete sample of 3C radio sources with z < 0.3 for 8 ks each. In the first paper, we illustrated the basic data reduction and analysis procedures performed for the 30 sources of the 3C sample observed during Chandra Cycle 9, while here we present the data for the remaining 27 sources observed during Cycle 12. We measured the X-ray intensity of the nuclei and of any radio hot spots and jet features with associated X-ray emission. X-ray fluxes in three energy bands, i.e., soft, medium, and hard, for all the sources analyzed are also reported. For the stronger nuclei, we also applied the standard spectral analysis, which provides the best-fit values of the X-ray spectral index and absorbing column density. In addition, a detailed analysis of bright X-ray nuclei that could be affected by pile-up has been performed. X-ray emission was detected for all the nuclei of the radio sources in our sample except for 3C 319. Among the current sample, there are two compact steep spectrum radio sources, two broad-line radio galaxies, and one wide angle tail radio galaxy, 3C 89, hosted in a cluster of galaxies clearly visible in our Chandra snapshot observation. In addition, we also detected soft X-ray emission arising from the galaxy cluster surrounding 3C 196.1. Finally, X-ray emission from hot spots has been found in three FR II radio sources and, in the case of 3C 459, we also report the detection of X-ray emission associated with the eastern radio lobe as well as X-ray emission cospatial with radio jets in 3C 29 and 3C 402.

  19. The concentration-mass relation of clusters of galaxies from the OmegaWINGS survey

    Science.gov (United States)

    Biviano, A.; Moretti, A.; Paccagnella, A.; Poggianti, B. M.; Bettoni, D.; Gullieuszik, M.; Vulcani, B.; Fasano, G.; D'Onofrio, M.; Fritz, J.; Cava, A.

    2017-11-01

    Context. The relation between a cosmological halo concentration and its mass (cMr) is a powerful tool to constrain cosmological models of halo formation and evolution. Aims: On the scale of galaxy clusters the cMr has so far been determined mostly with X-ray and gravitational lensing data. The use of independent techniques is helpful in assessing possible systematics. Here we provide one of the few determinations of the cMr by the dynamical analysis of the projected-phase-space distribution of cluster members. Methods: Based on the WINGS and OmegaWINGS data sets, we used the Jeans analysis with the MAMPOSSt technique to determine masses and concentrations for 49 nearby clusters, each of which has ≳60 spectroscopic members within the virial region, after removal of substructures. Results: Our cMr is in statistical agreement with theoretical predictions based on ΛCDM cosmological simulations. Our cMr is different from most previous observational determinations because of its flatter slope and lower normalization. It is however in agreement with two recent cMr obtained using the lensing technique on the CLASH and LoCuSS cluster data sets. Conclusions: The dynamical study of the projected-phase-space of cluster members is an independent and valid technique to determine the cMr of galaxy clusters. Our cMr shows no tension with theoretical predictions from ΛCDM cosmological simulations for low-redshift, massive galaxy clusters. In the future we will extend our analysis to galaxy systems of lower mass and at higher redshifts.

  20. Numerical linked-cluster algorithms. II. t-J models on the square lattice.

    Science.gov (United States)

    Rigol, Marcos; Bryant, Tyler; Singh, Rajiv R P

    2007-06-01

    We discuss the application of a recently introduced numerical linked-cluster (NLC) algorithm to strongly correlated itinerant models. In particular, we present a study of thermodynamic observables: chemical potential, entropy, specific heat, and uniform susceptibility for the t-J model on the square lattice, with Jt=0.5 and 0.3. Our NLC results are compared with those obtained from high-temperature expansions (HTE) and the finite-temperature Lanczos method (FTLM). We show that there is a sizeable window in temperature where NLC results converge without extrapolations whereas HTE diverges. Upon extrapolations, the overall agreement between NLC, HTE, and FTLM is excellent in some cases down to 0.25t . At intermediate temperatures NLC results are better controlled than other methods, making it easier to judge the convergence and numerical accuracy of the method.

  1. Improved wavelet-packet compression of electrocardiogram data II: coding of compressor output and QRS clustering

    Science.gov (United States)

    Bradie, Brian D.

    1996-10-01

    Two modifications to a wavelet packet based compression scheme for single lead electrocardiogram data have been tested for their effect upon compression performance. First, differential pulse code modulation and an adaptive arithmetic coder wee implemented to improve the coding of the major components of compressor output. The improved strategies produced a 17 percent reduction in average data rate; since all techniques were lossless, there was no effect on the quality of the reconstructed signals. Second, 'QRS clustering' was incorporated into the preprocessing stage of the algorithm. Beats of similar structure were grouped, and a separate average, vector was maintained for the dominant and non-dominant beat types found in the signal. Beat similarity was quantified using a combination of linear correlation and average, absolute, point-by-point difference. A significant reduction in coefficient data rate was anticipated; however, for the test cases used in this study, a slight increase in coefficient data rate was produced.

  2. Multifrequency electron spin-echo envelope modulation studies of nitrogen ligation to the manganese cluster of photosystem II.

    Science.gov (United States)

    Yeagle, Gregory J; Gilchrist, M Lane; Walker, Lee M; Debus, Richard J; Britt, R David

    2008-03-27

    The CalEPR Center at UC-Davis (http://brittepr.ucdavis.edu) is equipped with five research grade electron paramagnetic resonance (EPR) instruments operating at various excitation frequencies between 8 and 130GHz. Of particular note for this RSC meeting are two pulsed EPR spectrometers working at the intermediate microwave frequencies of 31 and 35GHz. Previous lower frequency electron spin-echo envelope modulation (ESEEM) studies indicated that histidine nitrogen is electronically coupled to the Mn cluster in the S2 state of photosystem II (PSII). However, the amplitude and resolution of the spectra were relatively poor at these low frequencies, precluding any in-depth analysis of the electronic structure properties of this closely associated nitrogen nucleus. With the intermediate frequency instruments, we are much closer to the 'exact cancellation' limit, which optimizes ESEEM spectra for hyperfine-coupled nuclei such as 14N and 15N. Herein, we report the results from ESEEM studies of both 14N- and 15N-labelled PSII at these two frequencies. Spectral simulations were constrained by both isotope datasets at both frequencies, with a focus on high-resolution spectral examination of the histidine ligation to the Mn cluster in the S2 state.

  3. Proton Matrix ENDOR Studies on Ca2+-depleted and Sr2+-substituted Manganese Cluster in Photosystem II.

    Science.gov (United States)

    Nagashima, Hiroki; Nakajima, Yoshiki; Shen, Jian-Ren; Mino, Hiroyuki

    2015-11-20

    Proton matrix ENDOR spectra were measured for Ca(2+)-depleted and Sr(2+)-substituted photosystem II (PSII) membrane samples from spinach and core complexes from Thermosynechococcus vulcanus in the S2 state. The ENDOR spectra obtained were similar for untreated PSII from T. vulcanus and spinach, as well as for Ca(2+)-containing and Sr(2+)-substituted PSII, indicating that the proton arrangements around the manganese cluster in cyanobacterial and higher plant PSII and Ca(2+)-containing and Sr(2+)-substituted PSII are similar in the S2 state, in agreement with the similarity of the crystal structure of both Ca(2+)-containing and Sr(2+)-substituted PSII in the S1 state. Nevertheless, slightly different hyperfine separations were found between Ca(2+)-containing and Sr(2+)-substituted PSII because of modifications of the water protons ligating to the Sr(2+) ion. Importantly, Ca(2+) depletion caused the loss of ENDOR signals with a 1.36-MHz separation because of the loss of the water proton W4 connecting Ca(2+) and YZ directly. With respect to the crystal structure and the functions of Ca(2+) in oxygen evolution, it was concluded that the roles of Ca(2+) and Sr(2+) involve the maintenance of the hydrogen bond network near the Ca(2+) site and electron transfer pathway to the manganese cluster. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  4. Proton Matrix ENDOR Studies on Ca2+-depleted and Sr2+-substituted Manganese Cluster in Photosystem II*

    Science.gov (United States)

    Nagashima, Hiroki; Nakajima, Yoshiki; Shen, Jian-Ren; Mino, Hiroyuki

    2015-01-01

    Proton matrix ENDOR spectra were measured for Ca2+-depleted and Sr2+-substituted photosystem II (PSII) membrane samples from spinach and core complexes from Thermosynechococcus vulcanus in the S2 state. The ENDOR spectra obtained were similar for untreated PSII from T. vulcanus and spinach, as well as for Ca2+-containing and Sr2+-substituted PSII, indicating that the proton arrangements around the manganese cluster in cyanobacterial and higher plant PSII and Ca2+-containing and Sr2+-substituted PSII are similar in the S2 state, in agreement with the similarity of the crystal structure of both Ca2+-containing and Sr2+-substituted PSII in the S1 state. Nevertheless, slightly different hyperfine separations were found between Ca2+-containing and Sr2+-substituted PSII because of modifications of the water protons ligating to the Sr2+ ion. Importantly, Ca2+ depletion caused the loss of ENDOR signals with a 1.36-MHz separation because of the loss of the water proton W4 connecting Ca2+ and YZ directly. With respect to the crystal structure and the functions of Ca2+ in oxygen evolution, it was concluded that the roles of Ca2+ and Sr2+ involve the maintenance of the hydrogen bond network near the Ca2+ site and electron transfer pathway to the manganese cluster. PMID:26438823

  5. A Large Sample of Proto-Clusters and Proto-Groups from the VIMOS Ultra-Deep Survey

    Science.gov (United States)

    Lemaux, Brian C.

    2017-07-01

    Using observations from the VIMOS Ultra-Deep Survey (VUDS), a massive spectroscopic campaign targeting 10,000 typical star-forming galaxies at 2 groups forming in the early universe. Though ostensibly a field survey, a number of factors relating to the survey itself and intrinsic to proto-structures have allowed VUDS to sample a large range of local and global densities at these redshifts. In this talk, I will discuss the development of the methods for finding, confirming, and characterizing proto-clusters and proto-groups in the context of VUDS including new techniques and tools developed specifically for these purposes. Several case studies of spectroscopically confirmed massive proto-clusters will be presented, focused both on the diversity of their global properties and that of their member populations. I will also discuss preliminary work on the full ensemble of VUDS proto-structures as well as measurements of the star formation rate-density and color-density relations at these redshifts.

  6. On the statistics of proto-cluster candidates detected in the Planck all-sky survey

    Science.gov (United States)

    Negrello, M.; Gonzalez-Nuevo, J.; De Zotti, G.; Bonato, M.; Cai, Z.-Y.; Clements, D.; Danese, L.; Dole, H.; Greenslade, J.; Lapi, A.; Montier, L.

    2017-09-01

    Observational investigations of the abundance of massive precursors of local galaxy clusters ('proto-clusters') allow us to test the growth of density perturbations, to constrain cosmological parameters that control it, to test the theory of non-linear collapse and how the galaxy formation takes place in dense environments. The Planck collaboration has recently published a catalogue of ≳2000 cold extragalactic sub-millimeter sources, I.e. with colours indicative of z ≳ 2, almost all of which appear to be overdensities of star-forming galaxies. They are thus considered as proto-cluster candidates. Their number densities (or their flux densities) are far in excess of expectations from the standard scenario for the evolution of large-scale structure. Simulations based on a physically motivated galaxy evolution model show that essentially all cold peaks brighter than S545GHz = 500 mJy found in Planck maps after having removed the Galactic dust emission can be interpreted as positive Poisson fluctuations of the number of high-z dusty proto-clusters within the same Planck beam, rather then being individual clumps of physically bound galaxies. This conclusion does not change if an empirical fit to the luminosity function of dusty galaxies is used instead of the physical model. The simulations accurately reproduce the statistic of the Planck detections and yield distributions of sizes and ellipticities in qualitative agreement with observations. The redshift distribution of the brightest proto-clusters contributing to the cold peaks has a broad maximum at 1.5 ≤ z ≤ 3. Therefore follow-up of Planck proto-cluster candidates will provide key information on the high-z evolution of large scale structure.

  7. EVOLUTION OF GROUP GALAXIES FROM THE FIRST RED-SEQUENCE CLUSTER SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Li, I. H. [Centre for Astrophysics and Supercomputing, Swinburne University of Technology, P.O. Box 218, Hawthorn, Victoria 3122 (Australia); Yee, H. K. C. [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4 (Canada); Hsieh, B. C. [Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 106, Taiwan (China); Gladders, M., E-mail: tli@astro.swin.edu.au, E-mail: hyee@astro.utoronto.ca, E-mail: bchsieh@asiaa.sinica.edu.tw, E-mail: gladders@oddjob.uchicago.edu [Department of Astronomy and Astrophysics, University of Chicago, 5640 S. Ellis Ave, Chicago, IL 60637 (United States)

    2012-04-20

    We study the evolution of the red-galaxy fraction (f{sub red}) in 905 galaxy groups with 0.15 {<=} z < 0.52. The galaxy groups are identified by the 'probability friends-of-friends' algorithm from the first Red-Sequence Cluster Survey (RCS1) photometric-redshift sample. There is a high degree of uniformity in the properties of the red sequence of the group galaxies, indicating that the luminous red-sequence galaxies in the groups are already in place by z {approx} 0.5 and that they have a formation epoch of z {approx}> 2. In general, groups at lower redshifts exhibit larger f{sub red} than those at higher redshifts, showing a group Butcher-Oemler effect. We investigate the evolution of f{sub red} by examining its dependence on four parameters, one of which can be classified as intrinsic and three of which can be classified as environmental: galaxy stellar mass (M{sub *}), total group stellar mass (M{sub *,grp}, a proxy for group halo mass), normalized group-centric radius (r{sub grp}), and local galaxy density ({Sigma}{sub 5}). We find that M{sub *} is the dominant parameter such that there is a strong correlation between f{sub red} and galaxy stellar mass. Furthermore, the dependence of f{sub red} on the environmental parameters is also a strong function of M{sub *}. Massive galaxies (M{sub *} {approx}> 10{sup 11} M{sub Sun }) show little dependence of f{sub red} on r{sub grp}, M{sub *,grp}, and {Sigma}{sub 5} over the redshift range. The dependence of f{sub red} on these parameters is primarily seen for galaxies with lower masses, especially for M{sub *} {approx}< 10{sup 10.6} M{sub Sun }. We observe an apparent 'group down-sizing' effect, in that galaxies in lower-mass halos, after controlling for galaxy stellar mass, have lower f{sub red}. We find a dependence of f{sub red} on both r{sub grp} and {Sigma}{sub 5} after the other parameters are controlled. At a fixed r{sub grp}, there is a significant dependence of f{sub red} on {Sigma}{sub 5

  8. The SCUBA-2 cosmology legacy survey: Ultraluminous star-forming galaxies in a z = 1.6 cluster

    Energy Technology Data Exchange (ETDEWEB)

    Smail, Ian; Swinbank, A. M.; Danielson, A. L. R.; Edge, A. C.; Simpson, J. M. [Institute for Computational Cosmology, Durham University, South Road, Durham DH1 3LE (United Kingdom); Geach, J. E. [Centre for Astrophysics Research, Science and Technology Research Institute, University of Hertfordshire, Hatfield AL10 9AB (United Kingdom); Tadaki, K. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo (Japan); Arumugam, V.; Dunlop, J. S.; Ivison, R. J. [Institute for Astronomy, Royal Observatory, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Hartley, W. [Institute for Astronomy, ETH Zurich, Wolfgang-Pauli-Strasse 27, CH-8093 Zurich (Switzerland); Almaini, O.; Conselice, C. [School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG9 2RD (United Kingdom); Bremer, M. N. [H. H. Wills Physics Laboratory, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Chapin, E. [XMM SOC, ESAC, Apartado 78, E-28691 Villanueva de la Canada, Madrid (Spain); Chapman, S. C. [Department of Physics and Atmospheric Science, Dalhousie University, 6310 Coburg Road, Halifax, Nova Scotia B3H 4R2 (Canada); Scott, D. [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada); Simpson, C. J. [Astrophysics Research Institute, Liverpool John Moores University, Liverpool Science Park, 146 Brownlow Hill, Liverpool L3 5RF (United Kingdom); Karim, A. [Argelander-Institute of Astronomy, Bonn University, Auf dem Hügel 71, D-53121, Bonn (Germany); Kodama, T. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); and others

    2014-02-10

    We analyze new SCUBA-2 submillimeter and archival SPIRE far-infrared imaging of a z = 1.62 cluster, Cl 0218.3–0510, which lies in the UKIRT Infrared Deep Sky Survey/Ultra-Deep Survey field of the SCUBA-2 Cosmology Legacy Survey. Combining these tracers of obscured star-formation activity with the extensive photometric and spectroscopic information available for this field, we identify 31 far-infrared/submillimeter-detected probable cluster members with bolometric luminosities ≳10{sup 12} L {sub ☉} and show that by virtue of their dust content and activity, these represent some of the reddest and brightest galaxies in this structure. We exploit ALMA submillimeter continuum observations, which cover one of these sources, to confirm the identification of a SCUBA-2-detected ultraluminous star-forming galaxy in this structure. Integrating the total star-formation activity in the central region of the structure, we estimate that it is an order of magnitude higher (in a mass-normalized sense) than clusters at z ∼ 0.5-1. However, we also find that the most active cluster members do not reside in the densest regions of the structure, which instead host a population of passive and massive, red galaxies. We suggest that while the passive and active populations have comparable near-infrared luminosities at z = 1.6, M{sub H} ∼ –23, the subsequent stronger fading of the more active galaxies means that they will evolve into passive systems at the present day that are less luminous than the descendants of those galaxies that were already passive at z ∼ 1.6 (M{sub H} ∼ –20.5 and M{sub H} ∼ –21.5, respectively, at z ∼ 0). We conclude that the massive galaxy population in the dense cores of present-day clusters were already in place at z = 1.6 and that in Cl 0218.3–0510 we are seeing continuing infall of less extreme, but still ultraluminous, star-forming galaxies onto a pre-existing structure.

  9. The SDSS-IV Extended Baryon Oscillation Spectroscopic Survey: The Clustering of Luminous Red Galaxies Using Photometric Redshifts

    Science.gov (United States)

    Prakash, Abhishek; SDSS-IV/eBOSS

    2017-01-01

    SDSS-IV/eBOSS survey will allow a ˜1% measurement of the Baryon Acoustic Oscillation (BAO) scale and a 4.0%Redshift Space Distortion (RSD) measurement using a relatively uniform set of luminous, early-type galaxies in the redshift range 0.6 < z < 1. In this talk, I will present the 3D real space clustering of a sample of ~600,000 LRGs measured by the SDSS/eBOSS, using photometric redshifts. These galaxies have accurate photometric redshifts with an average error of z = 0.028. These LRGs range from redshift z = 0.6 to 1.0 over 10,000 deg2 of the sky, making it the largest volume ever used for galaxy clustering measurements. We measure the angular clusteringpower spectrum in different redshift slices and use well-calibrated redshift distributions to combine these into a high precision 3D real space clustering. i will present an evidence for BAO in the 2-point correlation function. The detection of BAO also allows the measurement of the comoving distance to z = 1.0. Traditionally, spectroscopic redshifts are used to estimate distances to the galaxies and, in turn, to measuregalaxy clustering. However, acquiring spectroscopic redshifts is a time consuming and expensive process even with modern multi-fiber spectrographs. Although photometric redshifts are less accurate, they are signicantly easier to obtain, and for a constant amount of time, one can image both wider areas and deeper volumes than would be possible with spectroscopy, allowing one to probe both larger scales and larger volumes. The ability to make precise clustering measurements with photometric data has been well demonstrated by Padmanabhan et al. (2007).

  10. Type-Ia Supernova Rates to Redshift 2.4 from Clash: The Cluster Lensing and Supernova Survey with Hubble

    Science.gov (United States)

    Graur, O.; Rodney, S. A.; Maoz, D.; Riess, A. G.; Jha, S. W.; Postman, M.; Dahlen, T.; Holoien, T. W.-S.; McCully, C.; Patel, B.; hide

    2014-01-01

    We present the supernova (SN) sample and Type-Ia SN (SN Ia) rates from the Cluster Lensing And Supernova survey with Hubble (CLASH). Using the Advanced Camera for Surveys and the Wide Field Camera 3 on the Hubble Space Telescope (HST), we have imaged 25 galaxy-cluster fields and parallel fields of non-cluster galaxies. We report a sample of 27 SNe discovered in the parallel fields. Of these SNe, approximately 13 are classified as SN Ia candidates, including four SN Ia candidates at redshifts z greater than 1.2.We measure volumetric SN Ia rates to redshift 1.8 and add the first upper limit on the SN Ia rate in the range z greater than 1.8 and less than 2.4. The results are consistent with the rates measured by the HST/ GOODS and Subaru Deep Field SN surveys.We model these results together with previous measurements at z less than 1 from the literature. The best-fitting SN Ia delay-time distribution (DTD; the distribution of times that elapse between a short burst of star formation and subsequent SN Ia explosions) is a power law with an index of 1.00 (+0.06(0.09))/(-0.06(0.10)) (statistical) (+0.12/-0.08) (systematic), where the statistical uncertainty is a result of the 68% and 95% (in parentheses) statistical uncertainties reported for the various SN Ia rates (from this work and from the literature), and the systematic uncertainty reflects the range of possible cosmic star-formation histories. We also test DTD models produced by an assortment of published binary population synthesis (BPS) simulations. The shapes of all BPS double-degenerate DTDs are consistent with the volumetric SN Ia measurements, when the DTD models are scaled up by factors of 3-9. In contrast, all BPS single-degenerate DTDs are ruled out by the measurements at greater than 99% significance level.

  11. A national baseline prevalence survey of schistosomiasis in the Philippines using stratified two-step systematic cluster sampling design.

    Science.gov (United States)

    Leonardo, Lydia; Rivera, Pilarita; Saniel, Ofelia; Villacorte, Elena; Lebanan, May Antonnette; Crisostomo, Bobby; Hernandez, Leda; Baquilod, Mario; Erce, Edgardo; Martinez, Ruth; Velayudhan, Raman

    2012-01-01

    For the first time in the country, a national baseline prevalence survey using a well-defined sampling design such as a stratified two-step systematic cluster sampling was conducted in 2005 to 2008. The purpose of the survey was to stratify the provinces according to prevalence of schistosomiasis such as high, moderate, and low prevalence which in turn would be used as basis for the intervention program to be implemented. The national survey was divided into four phases. Results of the first two phases conducted in Mindanao and the Visayas were published in 2008. Data from the last two phases showed three provinces with prevalence rates higher than endemic provinces surveyed in the first two phases thus changing the overall ranking of endemic provinces at the national level. Age and sex distribution of schistosomiasis remained the same in Luzon and Maguindanao. Soil-transmitted and food-borne helminthes were also recorded in these surveys. This paper deals with the results of the last 2 phases done in Luzon and Maguindanao and integrates all four phases in the discussion.

  12. A National Baseline Prevalence Survey of Schistosomiasis in the Philippines Using Stratified Two-Step Systematic Cluster Sampling Design

    Directory of Open Access Journals (Sweden)

    Lydia Leonardo

    2012-01-01

    Full Text Available For the first time in the country, a national baseline prevalence survey using a well-defined sampling design such as a stratified two-step systematic cluster sampling was conducted in 2005 to 2008. The purpose of the survey was to stratify the provinces according to prevalence of schistosomiasis such as high, moderate, and low prevalence which in turn would be used as basis for the intervention program to be implemented. The national survey was divided into four phases. Results of the first two phases conducted in Mindanao and the Visayas were published in 2008. Data from the last two phases showed three provinces with prevalence rates higher than endemic provinces surveyed in the first two phases thus changing the overall ranking of endemic provinces at the national level. Age and sex distribution of schistosomiasis remained the same in Luzon and Maguindanao. Soil-transmitted and food-borne helminthes were also recorded in these surveys. This paper deals with the results of the last 2 phases done in Luzon and Maguindanao and integrates all four phases in the discussion.

  13. Clustering of far-infrared galaxies in the AKARI All-Sky Survey

    Science.gov (United States)

    Pollo, A.; Takeuchi, T. T.; Suzuki, T. L.; Oyabu, S.

    2013-03-01

    We present the first measurement of the angular two-point correlation function for AKARI 90-μm point sources, detected outside of the Milky Way plane and other regions characterized by high Galactic extinction, and categorized as extragalactic sources according to our far-infrared-color based criterion (Pollo et al., 2010). This is the first measurement of the large-scale angular clustering of galaxies selected in the far-infrared after IRAS measurements. Although a full description of the clustering properties of these galaxies will be obtained by more detailed studies, using either a spatial correlation function, or better information about properties and, at least, photometric redshifts of these galaxies, the angular correlation function remains the first diagnostic tool to establish the clustering properties of the catalog and the observed galaxy population. We find a non-zero clustering signal in both hemispheres extending up to ~40 degrees, without any significant fluctuations at larger scales. The observed correlation function is well fitted by a power-law function. The notable differences between the northern and southern hemispheres are found, which can probably be attributed to the photometry problems, and might point to the necessity of performing a better calibration in the data from the southern hemisphere.

  14. Photophysical responses in Pt2Pb clusters driven by solvent interactions and structural changes in the Pb(II) environment.

    Science.gov (United States)

    Berenguer, Jesús R; Lalinde, Elena; Martín, Antonio; Moreno, M Teresa; Ruiz, Santiago; Sánchez, Sergio; Shahsavari, Hamid R

    2014-08-18

    Two types of Pt2Pb luminescent clusters were successfully prepared by the reaction of [Pt(C6F5)(bzq)(OCMe2)] (1) and [Pt(C6F5)(ppy)(dmso)] (2) with [Pb(SpyR-5)2] (R = H, CF3). Thus, whereas 5 (ppy, Spy) is generated through coordination of the pyridine-N atoms to the Pt centers, the formation of 3, 4 (bzq), and 6 (ppy, SpyCF3) is accompanied by a formal thiolate transfer from Pb(II) to Pt(II), keeping the two N atoms in the primary environment of the lead. In 5, the neutral Pb center adopts a rather stable and symmetrical "Pt2S2" coordination sphere supplemented by two Pb··Fo contacts, whereas for the remaining species several pseudopolymorphs were found depending on the solvent (3, 4) and crystallization conditions (6). This structural diversity relies on changes in the coordination mode of the SpyR ligands (μ-κS,N/μ-κ(3)S,N,S), intermetallic Pt-Pb bonds, and secondary intra- and intermolecular contacts induced by Pb-solvent binding. Notably, the changes, which entail a slight tuning of the stereochemical activity of the lone pair, have also a remarkable impact on the emissive state ((3)L'CCT/(3)L'LCT, SpyR → Pb,Pt/(C(∧)N) in nature). Clusters 3 and 4 display a distinct and fast reversible blue shift vapoluminescent response (4 shows also color changes) to donor solvents, correlated with changes in the environment of the Pb(II) ion (asymmetric hemidirected to more symmetric holodirected) upon solvent binding and, additionally, in 4 with modifications in the crystal packing, as confirmed by XRD and supported by TD-DFT calculations. 5 and 6 do not show a vapoluminescent response. However, for 6, three different and interconvertible forms, a symmetrical form (yellow 6-y) and two asymmetrical forms with a rather short Pt-Pb bond (pale orange 6·acetone and orange 6-o), exhibiting different emissions were found. Notably, slow crystallization and low concentration favor the formation of the thermodynamically more stable yellow form, whereas fast

  15. Stellar streams as gravitational experiments. II. Asymmetric tails of globular cluster streams

    Science.gov (United States)

    Thomas, G. F.; Famaey, B.; Ibata, R.; Renaud, F.; Martin, N. F.; Kroupa, P.

    2018-01-01

    Kinematically cold tidal streams of globular clusters (GC) are excellent tracers of the Galactic gravitational potential at moderate Galactocentric distances, and can also be used as probes of the law of gravity on Galactic scales. Here, we compare for the first time the generation of such streams in Newtonian and Milgromian gravity (MOND). We first computed analytical results to investigate the expected shape of the GC gravitational potential in both frameworks, and we then ran N-body simulations with the Phantom of Ramses code. We find that the GCs tend to become lopsided in MOND. This is a consequence of the external field effect which breaks the strong equivalence principle. When the GC is filling its tidal radius the lopsidedness generates a strongly asymmetric tidal stream. In Newtonian dynamics, such markedly asymmetric streams can in general only be the consequence of interactions with dark matter subhalos, giant molecular clouds, or interaction with the Galactic bar. In these Newtonian cases, the asymmetry is the consequence of a very large gap in the stream, whilst in MOND it is a true asymmetry. This should thus allow us in the future to distinguish these different scenarios by making deep observations of the environment of the asymmetric stellar stream of Palomar 5. Moreover, our simulations indicate that the high internal velocity dispersion of Palomar 5 for its small stellar mass would be natural in MOND. The movie is available in electronic form at http://www.aanda.org

  16. Breaking the Gordian Knot in the Structural Chemistry of Polyoxometalates: Copper(II)-Oxo/Hydroxo Clusters.

    Science.gov (United States)

    Kondinski, Aleksandar; Monakhov, Kirill Yu

    2017-06-12

    This Concept article provides insights into the molecular design and construction aspects of polyoxocuprates (POCus), an emerging class of polyoxometalate (POM)-like architectures featuring low-to-high nuclearity copper(II)-oxo/hydroxo skeletons. POCus have been identified to adopt the structural principles of classical POMs consisting of early transition metals. Their potential to afford motifs of the noble-metal-based POMs is exploited. "Cross-structural topological transformation" is introduced to generalize skeletal relationships between POCus and POMs. The study opens up strategies toward the brand-new structural chemistry of POCus with relevance to homogeneous photocatalysis, medicinal chemistry, molecular magnetism, and quantum computing. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. A deep Spitzer survey of circumstellar disks in the young double cluster, h and χ Persei

    Energy Technology Data Exchange (ETDEWEB)

    Cloutier, Ryan; Currie, Thayne; Jayawardhana, Ray [University of Toronto, 50 St. George Street, Toronto, ON, M5S 2J7 (Canada); Rieke, George H. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721-0065 (United States); Kenyon, Scott J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02140 (United States); Balog, Zoltan, E-mail: cloutier@cita.utoronto.ca, E-mail: currie@astro.utoronto.ca, E-mail: grieke@as.arizona.edu, E-mail: skenyon@cfa.harvard.edu [Max Planck Institute for Astrophysics, Königstuhl 17, D-69117 Heidelberg (Germany)

    2014-12-01

    We analyze very deep Infrared Array Camera and Multiband Imaging Photometer for Spitzer (MIPS) photometry of ∼12, 500 members of the 14 Myr old Double Cluster, h and χ Persei, building upon our earlier, shallower Spitzer Cycle 1 studies. Numerous likely members show infrared (IR) excesses at 8 μm and 24 μm, indicative of circumstellar dust. The frequency of stars with 8 μm excess is at least 2% for our entire sample, slightly lower (higher) for B/A stars (later type, lower mass stars). Optical spectroscopy also identifies gas in about 2% of systems, but with no clear trend between the presence of dust and gas. Spectral energy distribution modeling of 18 sources with detections at optical wavelengths through MIPS 24 μm reveals a diverse set of disk evolutionary states, including a high fraction of transitional disks, though similar data for all disk-bearing members would provide constraints. Using Monte Carlo simulations, we combine our results with those for other young clusters to study the global evolution of dust/gas disks. For nominal cluster ages, the e-folding times (τ{sub 0}) for the frequency of warm dust and gas are 2.75 Myr and 1.75 Myr, respectively. Assuming a revised set of ages for some clusters, these timescales increase to 5.75 and 3.75 Myr, respectively, implying a significantly longer typical protoplanetary disk lifetime than previously thought. In both cases, the transitional disk duration, averaged over multiple evolutionary pathways, is ≈1 Myr. Finally, 24 μm excess frequencies for 4-6 M {sub ☉} stars appear lower than for 1-2.5 M {sub ☉} stars in other 10-30 Myr old clusters.

  18. Exploring the nature and synchronicity of early cluster formation in the Large Magellanic Cloud - II. Relative ages and distances for six ancient globular clusters

    Science.gov (United States)

    Wagner-Kaiser, R.; Mackey, Dougal; Sarajedini, Ata; Chaboyer, Brian; Cohen, Roger E.; Yang, Soung-Chul; Cummings, Jeffrey D.; Geisler, Doug; Grocholski, Aaron J.

    2017-11-01

    We analyse Hubble Space Telescope observations of six globular clusters in the Large Magellanic Cloud (LMC) from programme GO-14164 in Cycle 23. These are the deepest available observations of the LMC globular cluster population; their uniformity facilitates a precise comparison with globular clusters in the Milky Way. Measuring the magnitude of the main-sequence turn-off point relative to template Galactic globular clusters allows the relative ages of the clusters to be determined with a mean precision of 8.4 per cent, and down to 6 per cent for individual objects. We find that the mean age of our LMC cluster ensemble is identical to the mean age of the oldest metal-poor clusters in the Milky Way halo to 0.2 ± 0.4 Gyr. This provides the most sensitive test to date of the synchronicity of the earliest epoch of globular cluster formation in two independent galaxies. Horizontal branch magnitudes and subdwarf fitting to the main sequence allow us to determine distance estimates for each cluster and examine their geometric distribution in the LMC. Using two different methods, we find an average distance to the LMC of 18.52 ± 0.05.

  19. Weak-lensing mass calibration of redMaPPer galaxy clusters in Dark Energy Survey Science Verification data

    Energy Technology Data Exchange (ETDEWEB)

    Melchior, P.; Gruen, D.; McClintock, T.; Varga, T. N.; Sheldon, E.; Rozo, E.; Amara, A.; Becker, M. R.; Benson, B. A.; Bermeo, A.; Bridle, S. L.; Clampitt, J.; Dietrich, J. P.; Hartley, W. G.; Hollowood, D.; Jain, B.; Jarvis, M.; Jeltema, T.; Kacprzak, T.; MacCrann, N.; Rykoff, E. S.; Saro, A.; Suchyta, E.; Troxel, M. A.; Zuntz, J.; Bonnett, C.; Plazas, A. A.; Abbott, T. M. C.; Abdalla, F. B.; Annis, J.; Benoit-Lévy, A.; Bernstein, G. M.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Carnero Rosell, A.; Carrasco Kind, M.; Carretero, J.; Cunha, C. E.; D’Andrea, C. B.; da Costa, L. N.; Desai, S.; Eifler, T. F.; Flaugher, B.; Fosalba, P.; García-Bellido, J.; Gaztanaga, E.; Gerdes, D. W.; Gruendl, R. A.; Gschwend, J.; Gutierrez, G.; Honscheid, K.; James, D. J.; Kirk, D.; Krause, E.; Kuehn, K.; Kuropatkin, N.; Lahav, O.; Lima, M.; Maia, M. A. G.; March, M.; Martini, P.; Menanteau, F.; Miller, C. J.; Miquel, R.; Mohr, J. J.; Nichol, R. C.; Ogando, R.; Romer, A. K.; Sanchez, E.; Scarpine, V.; Sevilla-Noarbe, I.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; Walker, A. R.; Weller, J.; Zhang, Y.

    2017-05-16

    We use weak-lensing shear measurements to determine the mean mass of optically selected galaxy clusters in Dark Energy Survey Science Verification data. In a blinded analysis, we split the sample of more than 8,000 redMaPPer clusters into 15 subsets, spanning ranges in the richness parameter $5 \\leq \\lambda \\leq 180$ and redshift $0.2 \\leq z \\leq 0.8$, and fit the averaged mass density contrast profiles with a model that accounts for seven distinct sources of systematic uncertainty: shear measurement and photometric redshift errors; cluster-member contamination; miscentering; deviations from the NFW halo profile; halo triaxiality; and line-of-sight projections. We combine the inferred cluster masses to estimate the joint scaling relation between mass, richness and redshift, $\\mathcal{M}(\\lambda,z) \\varpropto M_0 \\lambda^{F} (1+z)^{G}$. We find $M_0 \\equiv \\langle M_{200\\mathrm{m}}\\,|\\,\\lambda=30,z=0.5\\rangle=\\left[ 2.35 \\pm 0.22\\ \\rm{(stat)} \\pm 0.12\\ \\rm{(sys)} \\right] \\cdot 10^{14}\\ M_\\odot$, with $F = 1.12\\,\\pm\\,0.20\\ \\rm{(stat)}\\, \\pm\\, 0.06\\ \\rm{(sys)}$ and $G = 0.18\\,\\pm\\, 0.75\\ \\rm{(stat)}\\, \\pm\\, 0.24\\ \\rm{(sys)}$. The amplitude of the mass-richness relation is in excellent agreement with the weak-lensing calibration of redMaPPer clusters in SDSS by Simet et al. (2016) and with the Saro et al. (2015) calibration based on abundance matching of SPT-detected clusters. Our results extend the redshift range over which the mass-richness relation of redMaPPer clusters has been calibrated with weak lensing from $z\\leq 0.3$ to $z\\leq0.8$. Calibration uncertainties of shear measurements and photometric redshift estimates dominate our systematic error budget and require substantial improvements for forthcoming studies.

  20. Employing a New, BVIc Photometric Survey of IC 4665 to Investigate the Age of This Young Open Cluster

    Science.gov (United States)

    Cargile, P. A.; James, D. J.

    2010-09-01

    We present a new, BVI c photometric survey of the young open cluster IC 4665, which improves on previous studies of this young cluster by incorporating a rigorous standardization procedure, thus providing high-fidelity colors and magnitudes for cluster members. We use this new photometric dataset to reevaluate the properties (age and distance) of IC 4665. Namely, using a statistical approach incorporating τ2 color-magnitude diagram modeling, we measure a pre-main-sequence (PMS) isochrone age and distance of 36 ± 9 Myr and 360 ± 12 pc, as well as an upper-main-sequence turn-off age and distance of 42 ± 12 Myr and 357 ± 12 pc. These ages and distances are highly dependent on the isochrone model and color used for the fitting procedure, with a possible range of ~10-20 Myr in age and ~20 pc in distance. This spread in calculated ages and distances seen between colors and models is likely due to limitations in the individual membership catalogs and/or systematic differences in the predicted stellar parameters from the different sets of models. Interestingly, when we compare the isochrone ages for IC 4665 to the published lithium depletion boundary (LDB) age, 28 ± 5 Myr, we observe that this cluster does not appear to follow the trend of isochrone ages being 1.5 times smaller than LDB ages. In addition, comparing the overall magnetic activity (X-ray and Hα emission) in IC 4665 with other well-studied open clusters, we find that the observed activity distributions for this young cluster are best characterized by assuming an age of 30-40 Myr, thus in agreement with our PMS and turn-off isochrone ages for IC 4665. Overall, although some age discrepancies do exist, particularly in the ages measured from PMS isochrones, the range of possible IC 4665 ages derived from the various dating techniques employed here is relatively small compared to that found for other well-studied open clusters.

  1. Near-infrared spectroscopic survey of brown dwarfs using NIRSPEC on the Keck II Telescope

    Science.gov (United States)

    McLean, Ian S.

    2003-02-01

    Since commissioning the near-infrared spectrometer (NIRSPEC) on the Keck II telescope in April 1999 we have been carrying out an extensive spectroscopic survey of low-mass stars and brown dwarfs. At least two objects in every spectral sub-class from M6 to T8 have been observed in the J band at a resolution of R ~ 2,000. For a subset of these we have obtained complete near-infrared flux-calibrated spectra from 0.9 - 2.5 μm. In addition, J band spectra at even higher resolution (R ~ 20,000) have been obtained for many sub-classes. The results of the NIRSPEC Brown Dwarf Spectroscopic Survey (BDSS) are summarized in this paper and presented as an illustration of the progress in infrared technology and the scientific productivity of the Keck telescopes.

  2. Children Learning About Secondhand Smoke (CLASS II): protocol of a pilot cluster randomised controlled trial.

    Science.gov (United States)

    Siddiqi, Kamran; Huque, Rumana; Jackson, Cath; Parrott, Steve; Dogar, Omara; Shah, Sarwat; Thomson, Heather; Sheikh, Aziz

    2015-08-25

    Exposure to secondhand smoke (SHS) increases children's risk of acquiring chest and ear infections, tuberculosis, meningitis and asthma. Smoking bans in public places (where implemented) have significantly reduced adults' exposure to SHS. However, for children, homes remain the most likely place for them to be exposed to SHS. Additional measures are therefore required to protect children from SHS. In a feasibility study in Dhaka, Bangladesh, we have shown that a school-based smoke-free intervention (SFI) was successful in encouraging children to negotiate and implement smoking restrictions in homes. We will now conduct a pilot trial to inform plans to undertake a cluster randomised controlled trial (RCT) investigating the effectiveness and cost-effectiveness of SFI in reducing children's exposure to SHS. We plan to recruit 12 primary schools in Dhaka, Bangladesh. From these schools, we will recruit approximately 360 schoolchildren in year 5 (10-12 years old), that is, 30 per school. SFI consists of six interactive educational activities aimed at increasing pupils' knowledge about SHS and related harms, motivating them to act, providing skills to negotiate with adults to persuade them not to smoke inside homes and helping families to 'sign-up' to a voluntary contract to make their homes smoke-free. Children in the control arm will receive the usual education. We will estimate: recruitment and attrition rates, acceptability, fidelity to SFI, effect size, intracluster correlation coefficient, cost of intervention and adverse events. Our primary outcome will consist of SHS exposure in children measured by salivary cotinine. Secondary outcomes will include respiratory symptoms, lung function tests, healthcare contacts, school attendance, smoking uptake, quality of life and academic performance. The trial has received ethics approval from the Research Governance Committee at the University of York. Findings will help us plan for the definitive trial. ISRCTN68690577

  3. The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: single-probe measurements from DR12 galaxy clustering - towards an accurate model

    Science.gov (United States)

    Chuang, Chia-Hsun; Pellejero-Ibanez, Marcos; Rodríguez-Torres, Sergio; Ross, Ashley J.; Zhao, Gong-bo; Wang, Yuting; Cuesta, Antonio J.; Rubiño-Martín, J. A.; Prada, Francisco; Alam, Shadab; Beutler, Florian; Eisenstein, Daniel J.; Gil-Marín, Héctor; Grieb, Jan Niklas; Ho, Shirley; Kitaura, Francisco-Shu; Percival, Will J.; Rossi, Graziano; Salazar-Albornoz, Salvador; Samushia, Lado; Sánchez, Ariel G.; Satpathy, Siddharth; Slosar, Anže; Thomas, Daniel; Tinker, Jeremy L.; Tojeiro, Rita; Vargas-Magaña, Mariana; Vazquez, Jose A.; Brownstein, Joel R.; Nichol, Robert C.; Olmstead, Matthew D.

    2017-10-01

    We analyse the broad-range shape of the monopole and quadrupole correlation functions of the Baryon Oscillation Spectroscopic Survey Data Release 12 (DR12) CMASS and LOWZ galaxy sample to obtain constraints on the Hubble expansion rate H(z), the angular-diameter distance DA(z), the normalized growth rate f(z)σ8(z) and the physical matter density Ωm h2. We adopt wide and flat priors on all model parameters in order to ensure the results are those of a 'single-probe' galaxy clustering analysis. We also marginalize over three nuisance terms that account for potential observational systematics affecting the measured monopole. However, such Monte Carlo Markov Chain analysis is computationally expensive for advanced theoretical models. We develop a new methodology to speed up the analysis. Using the range 40 h-1 Mpc < s < 180 h-1 Mpc, we obtain {DA(z)rs,fid/rs (Mpc), H(z)rs/rs,fid km s-1 Mpc-1, f(z)σ8(z), Ωm h2} = {956 ± 28, 75.0 ± 4.0, 0.397 ± 0.073, 0.143 ± 0.017} at z = 0.32 and {1421 ± 23, 96.7 ± 2.7, 0.497 ± 0.058, 0.137 ± 0.015} at z = 0.59 where rs is the comoving sound horizon at the drag epoch and rs,fid = 147.66 Mpc for the fiducial cosmology used in this study. Combining our measurements with Planck data, we obtain Ωm = 0.306 ± 0.009, H0 = 67.9 ± 0.7 km s-1 Mpc-1 and σ8 = 0.815 ± 0.009 assuming Λcold dark matter (CDM); Ωk = 0.000 ± 0.003 and w = -1.02 ± 0.08 assuming owCDM. Our results show no tension with the flat ΛCDM cosmological paradigm. This paper is part of a set that analyses the final galaxy clustering data set from Baryon Oscillation Spectroscopic Survey.

  4. A prescription and fast code for the long-term evolution of star clusters - II. Unbalanced and core evolution

    NARCIS (Netherlands)

    Gieles, M.; Alexander, P.E.R.; Lamers, H.J.G.L.M.; Baumgardt, H.

    2014-01-01

    We introduce version two of the fast star cluster evolution code Evolve Me A Cluster of StarS (emacss). The first version (Alexander and Gieles) assumed that cluster evolution is balanced for the majority of the life cycle, meaning that the rate of energy generation in the core of the cluster equals

  5. The Hawaii SCUBA-2 Lensing Cluster Survey: Are Low-luminosity Submillimeter Galaxies Detected in the Rest-frame UV?

    Science.gov (United States)

    Hsu, Li-Yen; Cowie, Lennox L.; Barger, Amy J.; Wang, Wei-Hao

    2017-12-01

    In this third paper of the Hawaii SCUBA-2 Lensing Cluster Survey series, we present Submillimeter Array (SMA) detections of six intrinsically faint 850 μm sources detected in SCUBA-2 images of the lensing cluster fields, A1689, A2390, A370, MACS J0717.5+3745, and MACS J1423.8+2404. Two of the SCUBA-2 sources split into doublets, yielding a total of eight SMA detections. The intrinsic 870 μm flux densities of these submillimeter galaxies (SMGs) are ∼1 mJy. Five of the eight SMGs are not detected in optical or near-infrared (NIR) images. The NIR-to-submillimeter flux ratios of these faint SMGs suggest that most of them are extremely dusty and/or are at very high redshifts. By combining these SMGs and several other samples from the literature, we find a bimodal distribution for the faint sources in the space of submillimeter flux versus NIR-to-submillimeter flux ratio. While most of the SMA-detected lensed sources are very obscured, the other SMGs with similar flux densities are mostly bright in the NIR. Future Atacama Large Millimeter/submillimeter Array observations of a large sample of SCUBA-2 sources in cluster fields will allow us to decide whether or not the bimodality we observe here really exists.

  6. The Gaia-ESO Survey: dynamical models of flattened, rotating globular clusters

    Science.gov (United States)

    Jeffreson, S. M. R.; Sanders, J. L.; Evans, N. W.; Williams, A. A.; Gilmore, G. F.; Bayo, A.; Bragaglia, A.; Casey, A. R.; Flaccomio, E.; Franciosini, E.; Hourihane, A.; Jackson, R. J.; Jeffries, R. D.; Jofré, P.; Koposov, S.; Lardo, C.; Lewis, J.; Magrini, L.; Morbidelli, L.; Pancino, E.; Randich, S.; Sacco, G. G.; Worley, C. C.; Zaggia, S.

    2017-08-01

    We present a family of self-consistent axisymmetric rotating globular cluster models which are fitted to spectroscopic data for NGC 362, NGC 1851, NGC 2808, NGC 4372, NGC 5927 and NGC 6752 to provide constraints on their physical and kinematic properties, including their rotation signals. They are constructed by flattening Modified Plummer profiles, which have the same asymptotic behaviour as classical Plummer models, but can provide better fits to young clusters due to a slower turnover in the density profile. The models are in dynamical equilibrium as they depend solely on the action variables. We employ a fully Bayesian scheme to investigate the uncertainty in our model parameters (including mass-to-light ratios and inclination angles) and evaluate the Bayesian evidence ratio for rotating to non-rotating models. We find convincing levels of rotation only in NGC 2808. In the other clusters, there is just a hint of rotation (in particular, NGC 4372 and NGC 5927), as the data quality does not allow us to draw strong conclusions. Where rotation is present, we find that it is confined to the central regions, within radii of R ≤ 2rh. As part of this work, we have developed a novel q-Gaussian basis expansion of the line-of-sight velocity distributions, from which general models can be constructed via interpolation on the basis coefficients.

  7. Snapshot Survey of the Globular Cluster Populations of Isolated Early Type Galaxies

    Science.gov (United States)

    Gregg, Michael

    2017-08-01

    We propose WFC3/UVIS snapshot observations of a sample of 75 isolated early type galaxiesresiding in cosmic voids or extremely low density regions. The primary aim is to usetheir globular cluster populations to reconstruct their evolutionary history, revealingif, how, and why void ellipticals differ from cluster ellipticals. The galaxies span arange of luminosities, providing a varied sample for comparison with the well-documentedglobular cluster populations in denser environments. This proposed WFC3 study of isolatedearly type galaxies breaks new ground by targeting a sample which has thus far receivedlittle attention, and, significantly, this will be the first such study with HST.Characterizing early type galaxies in voids and their GC systems promises to increase ourunderstanding of galaxy formation and evolution of galaxies in general because isolatedobjects are the best approximation to a control sample that we have for understanding theinfluence of environment on formation and evolution. Whether these isolated objects turnout to be identical to or distinct from counterparts in other regions of the Universe,they will supply insight into the formation and evolution of all galaxies. Parallel ACSimaging will help to characterize the near field environments of the sample.

  8. Joint analysis of galaxy-galaxy lensing and galaxy clustering: Methodology and forecasts for Dark Energy Survey

    Energy Technology Data Exchange (ETDEWEB)

    Park, Y.; Krause, E.; Dodelson, S.; Jain, B.; Amara, A.; Becker, M. R.; Bridle, S. L.; Clampitt, J.; Crocce, M.; Fosalba, P.; Gaztanaga, E.; Honscheid, K.; Rozo, E.; Sobreira, F.; Sánchez, C.; Wechsler, R. H.; Abbott, T.; Abdalla, F. B.; Allam, S.; Benoit-Lévy, A.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Burke, D. L.; Carnero Rosell, A.; Carrasco Kind, M.; Carretero, J.; Castander, F. J.; da Costa, L. N.; DePoy, D. L.; Desai, S.; Dietrich, J. P.; Doel, P.; Eifler, T. F.; Fausti Neto, A.; Fernandez, E.; Finley, D. A.; Flaugher, B.; Gerdes, D. W.; Gruen, D.; Gruendl, R. A.; Gutierrez, G.; James, D. J.; Kent, S.; Kuehn, K.; Kuropatkin, N.; Lima, M.; Maia, M. A. G.; Marshall, J. L.; Melchior, P.; Miller, C. J.; Miquel, R.; Nichol, R. C.; Ogando, R.; Plazas, A. A.; Roe, N.; Romer, A. K.; Rykoff, E. S.; Sanchez, E.; Scarpine, V.; Schubnell, M.; Sevilla-Noarbe, I.; Soares-Santos, M.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thaler, J.; Vikram, V.; Walker, A. R.; Weller, J.; Zuntz, J.

    2016-09-30

    The joint analysis of galaxy-galaxy lensing and galaxy clustering is a promising method for inferring the growth function of large scale structure. Our analysis will be carried out on data from the Dark Energy Survey (DES), with its measurements of both the distribution of galaxies and the tangential shears of background galaxies induced by these foreground lenses. We develop a practical approach to modeling the assumptions and systematic effects affecting small scale lensing, which provides halo masses, and large scale galaxy clustering. Introducing parameters that characterize the halo occupation distribution (HOD), photometric redshift uncertainties, and shear measurement errors, we study how external priors on different subsets of these parameters affect our growth constraints. Degeneracies within the HOD model, as well as between the HOD and the growth function, are identified as the dominant source of complication, with other systematic effects sub-dominant. The impact of HOD parameters and their degeneracies necessitate the detailed joint modeling of the galaxy sample that we employ. Finally, we conclude that DES data will provide powerful constraints on the evolution of structure growth in the universe, conservatively/optimistically constraining the growth function to 7.9%/4.8% with its first-year data that covered over 1000 square degrees, and to 3.9%/2.3% with its full five-year data that will survey 5000 square degrees, including both statistical and systematic uncertainties.

  9. The Hawaii SCUBA-2 Lensing Cluster Survey: Radio-detected Submillimeter Galaxies in the HST Frontier Fields

    Science.gov (United States)

    Hsu, Li-Yen; Desai, Vandana; Murphy, Eric J.; Cowie, Lennox L.; Heywood, Ian; Momjian, Emmanuel; Barger, Amy J.; Smail, Ian

    2017-05-01

    In this second paper of the Hawaii SCUBA-2 Lensing Cluster Survey series, we cross-match SCUBA-2 maps with 3 and 6 GHz images from the Janksy-VLA Frontier Fields Legacy Survey for three cluster fields, MACS J0416.1-2403, MACS J0717.5+3745, and MACS J1149.5+2223. Within the HST coverage, 14 out of 44 850 μm sources have 3 GHz counterparts, five of which are also detected at 6 GHz. The 850 μm flux densities of these detected sources span from 0.7 to 4.4 mJy after correcting for lensing amplification. The median redshift of the sample is z={1.28}-0.09+0.07, much lower than the typical redshifts (z = 2-3) of brighter submillimeter galaxies (SMGs) in the literature. In addition, we find that our sources have lower dust temperatures than those of the brighter SMGs. This is also confirmed by an analysis of the ratio between infrared star-formation rate and 850 μm flux density. However, these 14 sources may not represent the general submillimeter population at the same flux range, given that the SCUBA-2 sources without radio counterparts are likely at higher redshifts. Detection of these sources would require deeper radio images or submillimeter interferometry.

  10. Measuring the Scatter of the Mass–Richness Relation in Galaxy Clusters in Photometric Imaging Surveys by Means of Their Correlation Function

    Energy Technology Data Exchange (ETDEWEB)

    Campa, Julia; Estrada, Juan; Flaugher, Brenna

    2017-02-03

    The knowledge of the scatter in the mass-observable relation is a key ingredient for a cosmological analysis based on galaxy clusters in a photometric survey. We demonstrate here how the linear bias measured in the correlation function for clusters can be used to determine the value of the scatter. The new method is tested in simulations of a 5.000 square degrees optical survey up to z~1, similar to the ongoing Dark Energy Survey. The results indicate that the scatter can be measured with a precision of 5% using this technique.

  11. Alchemical poetry in medieval and early modern Europe: a preliminary survey and synthesis. Part II - Synthesis.

    Science.gov (United States)

    Kahn, Didier

    2011-03-01

    This article provides a preliminary description of medieval and early modern alchemical poetry composed in Latin and in the principal vernacular languages of western Europe. It aims to distinguish the various genres in which this poetry flourished, and to identify the most representative aspects of each cultural epoch by considering the medieval and early modern periods in turn. Such a distinction (always somewhat artificial) between two broad historical periods may be justified by the appearance of new cultural phenomena that profoundly modified the character of early modern alchemical poetry: the ever-increasing importance of the prisca theologia, the alchemical interpretation of ancient mythology, and the rise of neo-Latin humanist poetry. Although early modern alchemy was marked by the appearance of new doctrines (notably the alchemical spiritus mundi and Paracelsianism), alchemical poetry was only superficially modified by criteria of a scientific nature, which therefore appear to be of lesser importance. This study falls into two parts. Part I provides a descriptive survey of extant poetry, and in Part II the results of the survey are analysed in order to highlight such distinctive features as the function of alchemical poetry, the influence of the book market on its evolution, its doctrinal content, and the question of whether any theory of alchemical poetry ever emerged. Part II is accompanied by an index of the authors and works cited in both parts.

  12. Hand washing behavior and associated factors in Vietnam based on the Multiple Indicator Cluster Survey, 2010-2011.

    Science.gov (United States)

    To, Kien Gia; Lee, Jong-Koo; Nam, You-Seon; Trinh, Oanh Thi Hoang; Van Do, Dung

    2016-01-01

    Handwashing is a cost-effective way of preventing communicable diseases such as respiratory and food-borne illnesses. However, handwashing rates are low in developing countries. Target 7C of the seventh Millennium Development Goals was to increase by half the proportion of people with sustainable access to safe drinking water and basic sanitation by 2015. Studies have found that better access to improved water sources and sanitation is associated with higher rates of handwashing. Our goal was to describe handwashing behaviour and identify the associated factors in Vietnamese households. Data from 12,000 households participating in the Vietnam Multiple Indicator Cluster Survey 2011 were used. The survey used a multistage sampling method to randomly select 100 clusters and 20 households per cluster. Self-administered questionnaires were used to collect data from a household representative. Demographic variables, the presence of a specific place for handwashing, soap and water, access to improved sanitation, and access to improved water sources were tested for association with handwashing behaviour in logistic regression. Almost 98% of households had a specific place for handwashing, and 85% had cleansing materials and water at such a place. The prevalence of handwashing in the sample was almost 85%. Educational level, ethnicity of the household head, and household wealth were factors associated with handwashing practice (pwater sources (OR=1.74, 95% CI: 1.37-2.21, pwater sources should be targeted for interventions implementing handwashing practice. In addition, the availability of soap and water at handwashing sites should be increased and practical teaching programs should be deployed in order to increase handwashing rates.

  13. Handwashing in 51 Countries: Analysis of Proxy Measures of Handwashing Behavior in Multiple Indicator Cluster Surveys and Demographic and Health Surveys, 2010-2013.

    Science.gov (United States)

    Kumar, Swapna; Loughnan, Libbet; Luyendijk, Rolf; Hernandez, Orlando; Weinger, Merri; Arnold, Fred; Ram, Pavani K

    2017-08-01

    In 2009, a common set of questions addressing handwashing behavior was introduced into nationally representative Demographic and Health Surveys (DHS) and Multiple Indicator Cluster Surveys (MICS), providing large amounts of comparable data from numerous countries worldwide. The objective of this analysis is to describe global handwashing patterns using two proxy indicators for handwashing behavior from 51 DHS and MICS surveys conducted in 2010-2013: availability of soap anywhere in the dwelling and access to a handwashing place with soap and water. Data were also examined across geographic regions, wealth quintiles, and rural versus urban settings. We found large disparities for both indicators across regions, and even among countries within the same World Health Organization region. Within countries, households in lower wealth quintiles and in rural areas were less likely to have soap anywhere in the dwelling and at designated handwashing locations than households in higher wealth quintiles and urban areas. In addition, disparities existed among various geographic regions within countries. This analysis demonstrates the need to promote access to handwashing materials and placement at handwashing locations in the dwelling, particularly in poorer, rural areas where children are more vulnerable to handwashing-preventable syndromes such as pneumonia and diarrhea.

  14. Direct Detection of Oxygen Ligation to the Mn4Ca Cluster of Photosystem II by X-ray Emission Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Pushkar, Yulia; Long, Xi; Glatzel, Pieter; Brudvig, Gary W.; Dismukes, G. Charles; Collins, Terrence J.; Yachandra, Vittal K.; Yano, Junko; Bergmann, Uwe

    2009-06-16

    Ligands play critical roles during the catalytic reactions in metalloproteins through bond formation/breaking, protonation/deprotonation, and electron/spin delocalization. While there are well-defined element-specific spectroscopic handles, such as X-ray spectroscopy and EPR, to follow the chemistry of metal catalytic sites in a large protein matrix, directly probing particular ligand atoms like C, N, and O is challenging due to their abundance in the protein. FTIR/Raman and ligand-sensitive EPR techniques such as ENDOR and ESEEM have been applied to study metal-ligand interactions. X-ray absorption spectroscopy (XAS) can also indirectly probe the ligand environment; its element-specificity allows us to focus only on the catalytic metal site, and EXAFS and XANES provide metal-ligand distances, coordination numbers, and symmetry of ligand environments. However, the information is limited, since one cannot distinguish among ligand elements with similar atomic number (i.e. C, N. and O). As an alternative and a more direct method to probe the specific metal-ligand chemistry in the protein matrix, we investigated the application of X-ray emission spectroscopy (XES). Using this technique we have identified the oxo-bridging ligands of the Mn{sub 4}Ca complex of photosystem II (PS II), a multisubunit membrane protein, that catalyzes the water oxidizing reaction. The catalytic mechanism has been studied intensively by Mn XAS. The fundamental question of this reaction, however, is how the water molecules are ligated to the Mn{sub 4}Ca cluster and how the O-O bond formation occurs before the evolution of O{sub 2}. This implies that it is necessary to follow the chemistry of the oxygen ligands in order to understand the mechanism.

  15. Statistical survey of the diamagnetic pressure in the mid-altitude cusp region: Cluster observation

    Science.gov (United States)

    Guo, Jianguang; Shi, Jiankui; Zhang, Tielong; Liu, Zhenxing

    The narrow funnel-shaped cusp stems from the interaction of the solar wind with the geomagnetic field in Earth's dayside magnetosphere. Many space missions, such as Hawkeye, IMP, HEOS and Polar, confirmed that a strong magnetic depression was a characteristic feature of the cusp. That results from the incoming magnetosheath particles, which both decrease total magnetic field as well as increase the ambient plasma density in the cusp region. Here, we present the results of a statistical study of the diamagnetic pressure as observed by Cluster in the cusp region from 4-8 Re. We identify the cusp region with Cluster magnetic field data and plasma data. The peak diamagnetic pressure is calculated by the change of magnetic pressure in the cusp, which involves calculating a boxcar average of the background field and subtracting the magnetic pressure of the background from the total pressure. The diamagnetic pressure shows strong dependence on the solar wind dynamic pressure as expected. The IMF Bz component also has influence on the value of the diamagnetic pressure. So the diamagnetic pressure of the cusp region is controlled by the fluid dynamics and electromagnetic dynamics of the solar wind.

  16. Atomic force microscopy of photosystem II and its unit cell clustering quantitatively delineate the mesoscale variability in Arabidopsis thylakoids.

    Science.gov (United States)

    Onoa, Bibiana; Schneider, Anna R; Brooks, Matthew D; Grob, Patricia; Nogales, Eva; Geissler, Phillip L; Niyogi, Krishna K; Bustamante, Carlos

    2014-01-01

    Photoautotrophic organisms efficiently regulate absorption of light energy to sustain photochemistry while promoting photoprotection. Photoprotection is achieved in part by triggering a series of dissipative processes termed non-photochemical quenching (NPQ), which depend on the re-organization of photosystem (PS) II supercomplexes in thylakoid membranes. Using atomic force microscopy, we characterized the structural attributes of grana thylakoids from Arabidopsis thaliana to correlate differences in PSII organization with the role of SOQ1, a recently discovered thylakoid protein that prevents formation of a slowly reversible NPQ state. We developed a statistical image analysis suite to discriminate disordered from crystalline particles and classify crystalline arrays according to their unit cell properties. Through detailed analysis of the local organization of PSII supercomplexes in ordered and disordered phases, we found evidence that interactions among light-harvesting antenna complexes are weakened in the absence of SOQ1, inducing protein rearrangements that favor larger separations between PSII complexes in the majority (disordered) phase and reshaping the PSII crystallization landscape. The features we observe are distinct from known protein rearrangements associated with NPQ, providing further support for a role of SOQ1 in a novel NPQ pathway. The particle clustering and unit cell methodology developed here is generalizable to multiple types of microscopy and will enable unbiased analysis and comparison of large data sets.

  17. Atomic force microscopy of photosystem II and its unit cell clustering quantitatively delineate the mesoscale variability in Arabidopsis thylakoids.

    Directory of Open Access Journals (Sweden)

    Bibiana Onoa

    Full Text Available Photoautotrophic organisms efficiently regulate absorption of light energy to sustain photochemistry while promoting photoprotection. Photoprotection is achieved in part by triggering a series of dissipative processes termed non-photochemical quenching (NPQ, which depend on the re-organization of photosystem (PS II supercomplexes in thylakoid membranes. Using atomic force microscopy, we characterized the structural attributes of grana thylakoids from Arabidopsis thaliana to correlate differences in PSII organization with the role of SOQ1, a recently discovered thylakoid protein that prevents formation of a slowly reversible NPQ state. We developed a statistical image analysis suite to discriminate disordered from crystalline particles and classify crystalline arrays according to their unit cell properties. Through detailed analysis of the local organization of PSII supercomplexes in ordered and disordered phases, we found evidence that interactions among light-harvesting antenna complexes are weakened in the absence of SOQ1, inducing protein rearrangements that favor larger separations between PSII complexes in the majority (disordered phase and reshaping the PSII crystallization landscape. The features we observe are distinct from known protein rearrangements associated with NPQ, providing further support for a role of SOQ1 in a novel NPQ pathway. The particle clustering and unit cell methodology developed here is generalizable to multiple types of microscopy and will enable unbiased analysis and comparison of large data sets.

  18. Gaia-ESO Survey: Global properties of clusters Trumpler 14 and 16 in the Carina nebula ⋆⋆

    Science.gov (United States)

    Damiani, F.; Klutsch, A.; Jeffries, R. D.; Randich, S.; Prisinzano, L.; Maíz Apellániz, J.; Micela, G.; Kalari, V.; Frasca, A.; Zwitter, T.; Bonito, R.; Gilmore, G.; Flaccomio, E.; Francois, P.; Koposov, S.; Lanzafame, A. C.; Sacco, G. G.; Bayo, A.; Carraro, G.; Casey, A. R.; Alfaro, E. J.; Costado, M. T.; Donati, P.; Franciosini, E.; Hourihane, A.; Jofré, P.; Lardo, C.; Lewis, J.; Magrini, L.; Monaco, L.; Morbidelli, L.; Worley, C. C.; Vink, J. S.; Zaggia, S.

    2017-07-01

    Aims: We present the first extensive spectroscopic study of the global population in star clusters Trumpler 16, Trumpler 14, and Collinder 232 in the Carina nebula, using data from the Gaia-ESO Survey, down to solar-mass stars. Methods: In addition to the standard homogeneous survey data reduction, a special processing was applied here because of the bright nebulosity surrounding Carina stars. Results: We find about 400 good candidate members ranging from OB types down to slightly subsolar masses. About 100 heavily reddened early-type Carina members found here were previously unrecognized or poorly classified, including two candidate O stars and several candidate Herbig Ae/Be stars. Their large brightness makes them useful tracers of the obscured Carina population. The spectroscopically derived temperatures for nearly 300 low-mass members enables the inference of individual extinction values and the study of the relative placement of stars along the line of sight. Conclusions: We find a complex spatial structure with definite clustering of low-mass members around the most massive stars and spatially variable extinction. By combining the new data with existing X-ray data, we obtain a more complete picture of the three-dimensional spatial structure of the Carina clusters and of their connection to bright and dark nebulosity and UV sources. The identification of tens of background giants also enables us to determine the total optical depth of the Carina nebula along many sightlines. We are also able to put constraints on the star formation history of the region with Trumpler 14 stars found to be systematically younger than stars in other subclusters. We find a large percentage of fast-rotating stars among Carina solar-mass members, which provide new constraints on the rotational evolution of pre-main-sequence stars in this mass range. Based on observations collected with the FLAMES spectrograph at VLT/UT2 telescope (Paranal Observatory, ESO, Chile), for the Gaia

  19. Yellow fever vaccination coverage following massive emergency immunization campaigns in rural Uganda, May 2011: a community cluster survey

    Science.gov (United States)

    2013-01-01

    Background Following an outbreak of yellow fever in northern Uganda in December 2010, Ministry of Health conducted a massive emergency vaccination campaign in January 2011. The reported vaccination coverage in Pader District was 75.9%. Administrative coverage though timely, is affected by incorrect population estimates and over or under reporting of vaccination doses administered. This paper presents the validated yellow fever vaccination coverage following massive emergency immunization campaigns in Pader district. Methods A cross sectional cluster survey was carried out in May 2011 among communities in Pader district and 680 respondents were indentified using the modified World Health Organization (WHO) 40 × 17 cluster survey sampling methodology. Respondents were aged nine months and above. Interviewer administered questionnaires were used to collect data on demographic characteristics, vaccination status and reasons for none vaccination. Vaccination status was assessed using self reports and vaccination card evidence. Our main outcomes were measures of yellow fever vaccination coverage in each age-specific stratum, overall, and disaggregated by age and sex, adjusting for the clustered design and the size of the population in each stratum. Results Of the 680 survey respondents, 654 (96.1%, 95% CI 94.9 – 97.8) reported being vaccinated during the last campaign but only 353 (51.6%, 95% CI 47.2 – 56.1) had valid yellow fever vaccination cards. Of the 280 children below 5 years, 269 (96.1%, 95% CI 93.7 – 98.7) were vaccinated and nearly all males 299 (96.9%, 95% CI 94.3 – 99.5) were vaccinated. The main reasons for none vaccination were; having travelled out of Pader district during the campaign period (40.0%), lack of transport to immunization posts (28.0%) and, sickness at the time of vaccination (16.0%). Conclusions Our results show that actual yellow fever vaccination coverage was high and satisfactory in Pader district since it was above the

  20. DISCOVERY OF A NEW MEMBER OF THE INNER OORT CLOUD FROM THE NEXT GENERATION VIRGO CLUSTER SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ying-Tung; Ip, Wing-Huen [Institute of Astronomy, National Central University, No. 300, Jhongda Road, Jhongli City, Taoyuan County 32001, Taiwan (China); Kavelaars, J. J.; Gwyn, Stephen; Ferrarese, Laura; Côté, Patrick [Herzberg Institute of Astrophysics, National Research Council of Canada, Victoria, BC V9E 2E7 (Canada); Jordán, Andrés; Suc, Vincent [Instituto de Astrofísica, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Macul 7820436, Santiago (Chile); Cuillandre, Jean-Charles, E-mail: charles@astro.ncu.edu.tw [Canada-France-Hawaii Telescope Corporation, 65-1238 Mamalahoa Hwy., Kamuela, HI 96743 (United States)

    2013-09-20

    We report the discovery of 2010 GB{sub 174}, a likely new member of the Inner Oort Cloud (IOC). 2010 GB{sub 174} is 1 of 91 trans-Neptunian objects and Centaurs discovered in a 76 deg{sup 2} contiguous region imaged as part of the Next Generation Virgo Cluster Survey (NGVS)—a moderate ecliptic latitude survey reaching a mean limiting magnitude of g' ≅ 25.5—using MegaPrime on the 3.6 m Canada-France-Hawaii Telescope. 2010 GB{sub 174} is found to have an orbit with a semi-major axis of a ≅ 350.8 AU, an inclination of i ≅ 21.°6, and a pericenter of q ∼ 48.5 AU. This is the second largest perihelion distance among known solar system objects. Based on the sky coverage and depth of the NGVS, we estimate the number of IOC members with sizes larger than 300 km (H{sub V} ≤ 6.2 mag) to be ≅ 11, 000. A comparison of the detection rate from the NGVS and the PDSSS (a characterized survey that 'rediscovered' the IOC object Sedna) gives, for an assumed a power-law luminosity function for IOC objects, a slope of α ≅ 0.7 ± 0.2. With only two detections in this region this slope estimate is highly uncertain.

  1. THE COORDINATED RADIO AND INFRARED SURVEY FOR HIGH-MASS STAR FORMATION. II. SOURCE CATALOG

    Energy Technology Data Exchange (ETDEWEB)

    Purcell, C. R.; Hoare, M. G.; Lumsden, S. L.; Urquhart, J. S. [School of Physics and Astronomy, E.C. Stoner Building, University of Leeds, Leeds LS2 9JT (United Kingdom); Cotton, W. D. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903-2475 (United States); Chandler, C. [National Radio Astronomy Observatory, Array Operations Center, P.O. Box O, 1003 Lopezville Road, Socorro, NM 87801-0387 (United States); Churchwell, E. B. [The University of Wisconsin, Department of Astronomy, 475 North Charter Street, Madison, WI 53706 (United States); Diamond, P.; Fuller, G.; Garrington, S. T. [Jodrell Bank Centre for Astrophysics, The Alan Turing Building, School of Physics and Astronomy, The University of Manchester, Oxford Rd, Manchester, M13 9PL (United Kingdom); Dougherty, S. M. [National Research Council of Canada, Herzberg Institute for Astrophysics, Dominion Radio Astrophysical Observatory, P.O. Box 248, Penticton, British Columbia V2A 6J9 (Canada); Fender, R. P. [School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ (United Kingdom); Gledhill, T. M. [Science and Technology Research Institute, University of Hertfordshire, College Lane, Hatfield AL10 9AB (United Kingdom); Goldsmith, P. F. [Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Hindson, L. [CSIRO Astronomy and Space Science, P.O. Box 76, Epping, NSW 1710 (Australia); Jackson, J. M. [Astronomy Department, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States); Kurtz, S. E. [Centro de Radioastronomia y Astrofisica, Universidad Nacional Autonoma de Mexico - Morelia, Apartado Postal 3-72, C.P. 58090 Morelia, Michoacan (Mexico); Marti, J., E-mail: C.R.Purcell@leeds.ac.uk [Departamento de Fisica, EPSJ, Universidad de Jaen, Campus Las Lagunillas s/n, Edif. A3, E-23071 Jaen (Spain); and others

    2013-03-01

    The CORNISH project is the highest resolution radio continuum survey of the Galactic plane to date. It is the 5 GHz radio continuum part of a series of multi-wavelength surveys that focus on the northern GLIMPSE region (10 Degree-Sign < l < 65 Degree-Sign ), observed by the Spitzer satellite in the mid-infrared. Observations with the Very Large Array in B and BnA configurations have yielded a 1.''5 resolution Stokes I map with a root mean square noise level better than 0.4 mJy beam{sup -1}. Here we describe the data-processing methods and data characteristics, and present a new, uniform catalog of compact radio emission. This includes an implementation of automatic deconvolution that provides much more reliable imaging than standard CLEANing. A rigorous investigation of the noise characteristics and reliability of source detection has been carried out. We show that the survey is optimized to detect emission on size scales up to 14'' and for unresolved sources the catalog is more than 90% complete at a flux density of 3.9 mJy. We have detected 3062 sources above a 7{sigma} detection limit and present their ensemble properties. The catalog is highly reliable away from regions containing poorly sampled extended emission, which comprise less than 2% of the survey area. Imaging problems have been mitigated by down-weighting the shortest spacings and potential artifacts flagged via a rigorous manual inspection with reference to the Spitzer infrared data. We present images of the most common source types found: H II regions, planetary nebulae, and radio galaxies. The CORNISH data and catalog are available online at http://cornish.leeds.ac.uk.

  2. Applying chimera virtual data concepts to cluster finding in the Sloan Sky Survey

    Energy Technology Data Exchange (ETDEWEB)

    James Annis et al.

    2002-08-13

    The GriPhyN project is one of several major efforts working to enable large-scale data-intensive computation as a routine scientific tool. GriPhyN focuses in particular on virtual data technologies that allow computational procedures and results to be exploited as community resources so that, for example, scientists can not only run their own computations on raw data, but also discover computational procedures developed by others and data produced by these procedures. A request to retrieve data on a particular cluster might thus either lead to the retrieval of the requested data from a local or remote database or the scheduling of a computation to produce the data.

  3. A Chemical Composition Survey of the Iron-complex Globular Cluster NGC 6273 (M19)

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Christian I.; Caldwell, Nelson [Harvard–Smithsonian Center for Astrophysics, 60 Garden Street, MS-15, Cambridge, MA 02138 (United States); Rich, R. Michael [Department of Physics and Astronomy, UCLA, 430 Portola Plaza, Box 951547, Los Angeles, CA 90095-1547 (United States); Mateo, Mario [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States); Bailey, John I. III [Leiden Observatory, Leiden University, P.O. Box 9513, 2300RA Leiden (Netherlands); Clarkson, William I. [Department of Natural Sciences, University of Michigan–Dearborn, 4901 Evergreen Road, Dearborn, MI 48128 (United States); Olszewski, Edward W. [Steward Observatory, The University of Arizona, 933 N. Cherry Avenue, Tucson, AZ 85721 (United States); Walker, Matthew G., E-mail: cjohnson@cfa.harvard.edu, E-mail: ncaldwell@cfa.harvard.edu, E-mail: rmr@astro.ucla.edu, E-mail: mmateo@umich.edu, E-mail: baileyji@strw.leidenuniv.nl, E-mail: wiclarks@umich.edu, E-mail: eolszewski@as.arizona.edu, E-mail: mgwalker@andrew.cmu.edu [McWilliams Center for Cosmology, Department of Physics, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213 (United States)

    2017-02-20

    Recent observations have shown that a growing number of the most massive Galactic globular clusters contain multiple populations of stars with different [Fe/H] and neutron-capture element abundances. NGC 6273 has only recently been recognized as a member of this “iron-complex” cluster class, and we provide here a chemical and kinematic analysis of >300 red giant branch and asymptotic giant branch member stars using high-resolution spectra obtained with the Magellan –M2FS and VLT–FLAMES instruments. Multiple lines of evidence indicate that NGC 6273 possesses an intrinsic metallicity spread that ranges from about [Fe/H] = −2 to −1 dex, and may include at least three populations with different [Fe/H] values. The three populations identified here contain separate first (Na/Al-poor) and second (Na/Al-rich) generation stars, but a Mg–Al anti-correlation may only be present in stars with [Fe/H] ≳ −1.65. The strong correlation between [La/Eu] and [Fe/H] suggests that the s-process must have dominated the heavy element enrichment at higher metallicities. A small group of stars with low [ α /Fe] is identified and may have been accreted from a former surrounding field star population. The cluster’s large abundance variations are coupled with a complex, extended, and multimodal blue horizontal branch (HB). The HB morphology and chemical abundances suggest that NGC 6273 may have an origin that is similar to ω Cen and M54.

  4. Large-scale clustering of galaxies in the CfA Redshift Survey

    Science.gov (United States)

    Vogeley, Michael S.; Park, Changbom; Geller, Margaret J.; Huchra, John P.

    1992-05-01

    The power spectrum of the galaxy distribution in the Center for Astrophysics Redshift Survey (de Lapparent et al., 1986; Geller and Huchra, 1989; and Huchra et al., 1992) is measured up to wavelengths of 200/h Mpc. Results are compared with several cosmological simulations with Gaussian initial conditions. It is shown that the power spectrum of the standard CDM model is inconsistent with the observed power spectrum at the 99 percent confidence level.

  5. Large-scale clustering of galaxies in the CfA Redshift Survey

    Science.gov (United States)

    Vogeley, Michael S.; Park, Changbom; Geller, Margaret J.; Huchra, John P.

    1992-01-01

    The power spectrum of the galaxy distribution in the Center for Astrophysics Redshift Survey (de Lapparent et al., 1986; Geller and Huchra, 1989; and Huchra et al., 1992) is measured up to wavelengths of 200/h Mpc. Results are compared with several cosmological simulations with Gaussian initial conditions. It is shown that the power spectrum of the standard CDM model is inconsistent with the observed power spectrum at the 99 percent confidence level.

  6. The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters - XII. The RGB Bumps of multiple stellar populations★

    Science.gov (United States)

    Lagioia, E. P.; Milone, A. P.; Marino, A. F.; Cassisi, S.; Aparicio, A. J.; Piotto, G.; Anderson, J.; Barbuy, B.; Bedin, L. R.; Bellini, A.; Brown, T.; D'Antona, F.; Nardiello, D.; Ortolani, S.; Pietrinferni, A.; Renzini, A.; Salaris, M.; Sarajedini, A.; van der Marel, R.; Vesperini, E.

    2018-01-01

    The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters is providing a major breakthrough in our knowledge of Globular Clusters (GCs) and their stellar populations. Among the main results, we discovered that all the studied GCs host two main discrete groups consisting of first generation (1G) and second generation (2G) stars. We exploit the multiwavelength photometry from this project to investigate, for the first time, the Red Giant Branch Bump (RGBB) of the two generations in a large sample of GCs. We identified, with high statistical significance, the RGBB of 1G and 2G stars in 26 GCs and found that their magnitude separation as a function of the filter wavelength follows comparable trends. The comparison of observations to synthetic spectra reveals that the RGBB luminosity depends on the stellar chemical composition and that the 2G RGBB is consistent with stars enhanced in He and N and depleted in C and O with respect to 1G stars. For metal-poor GCs the 1G and 2G RGBB relative luminosity in optical bands mostly depends on helium content, Y. We used the RGBB observations in F606W and F814W bands to infer the relative helium abundance of 1G and 2G stars in 18 GCs, finding an average helium enhancement Δ Y = 0.011± 0.002 of 2G stars with respect to 1G stars. This is the first determination of the average difference in helium abundance of multiple populations in a large number of clusters and provides a lower limit to the maximum internal variation of helium in GCs.

  7. Environmental monitoring survey of oil and gas fields in Region II in 2009. Summary report

    Energy Technology Data Exchange (ETDEWEB)

    2010-03-15

    The oil companies Statoil ASA, ExxonMobil Exploration and Production Norway AS, Total E&P Norge AS, Talisman Energy Norge AS and Marathon Petroleum Norge AS commissioned Section of Applied Environmental Research at UNI RESEARCH AS to undertake the monitoring survey of Region II in 2009. Similar monitoring surveys in Region II have been carried out in 1996, 2000, 2003 and 2006. The survey in 2009 included in total 18 fields: Rev, Varg, Sigyn, Sleipner Vest, Sleipner OEst, Sleipner Alfa Nord, Glitne, Grane, Balder, Ringhorne, Jotun, Vale, Skirne, Byggve, Heimdal, Volve, Vilje og Alvheim. Sampling was conducted from the vessel MV Libas between May 18 and May 27. Samples were collected from in totally 137 sampling sites, of which 15 were regional sampling sites. Samples for chemical analysis were collected at all sites, whereas samples for benthos analysis were collected at 12 fields. As in previous surveys, Region II is divided into natural sub-regions. One sub-region is shallow (77-96 m) sub-region, a central sub-region (107-130 m) and a northern subregion (115-119 m). The sediments of the shallow sub-region had relatively lower content of TOM and pelite and higher content of fine sand than the central and northern sub-regions. Calculated areas of contamination are shown for the sub-regions in Table 1.1. The fields Sigyn, Sleipner Alfa Nord, Glitne, Grane, Balder, Ringhorne, Jotun, Skirne, Byggve, Vilje og Alvheim showed no contamination of THC. At the other fields there were minor changes from 2006. The concentrations of barium increased in the central sub-region from 2006 to 2009, also at fields where no drilling had been undertaken during the last years. The same laboratory and methods are used during the three last regional investigations. The changes in barium concentrations may be due to high variability of barium concentrations in the sediments. This is supported by relatively large variations in average barium concentrations at the regional sampling sites in

  8. Survey of microsatellite clustering in eight fully sequenced species sheds light on the origin of compound microsatellites.

    Science.gov (United States)

    Kofler, Robert; Schlötterer, Christian; Luschützky, Evita; Lelley, Tamas

    2008-12-17

    Compound microsatellites are a special variation of microsatellites in which two or more individual microsatellites are found directly adjacent to each other. Until now, such composite microsatellites have not been investigated in a comprehensive manner. Our in silico survey of microsatellite clustering in genomes of Homo sapiens, Maccaca mulatta, Mus musculus, Rattus norvegicus, Ornithorhynchus anatinus, Gallus gallus, Danio rerio and Drosophila melanogaster revealed an unexpected high abundance of compound microsatellites. About 4 - 25% of all microsatellites could be categorized as compound microsatellites. Compound microsatellites are approximately 15 times more frequent than expected under the assumption of a random distribution of microsatellites. Interestingly, microsatellites do not only tend to cluster but the adjacent repeat types of compound microsatellites have very similar motifs: in most cases (>90%) these motifs differ only by a single mutation (base substitution or indel). We propose that the majority of the compound microsatellites originates by duplication of imperfections in a microsatellite tract. This process occurs mostly at the end of a microsatellite, leading to a new repeat type and a potential microsatellite repeat track. Our findings suggest a more dynamic picture of microsatellite evolution than previously believed. Imperfections within microsatellites might not only cause the "death" of microsatellites they might also result in their "birth".

  9. Survey of microsatellite clustering in eight fully sequenced species sheds light on the origin of compound microsatellites

    Directory of Open Access Journals (Sweden)

    Lelley Tamas

    2008-12-01

    Full Text Available Abstract Background Compound microsatellites are a special variation of microsatellites in which two or more individual microsatellites are found directly adjacent to each other. Until now, such composite microsatellites have not been investigated in a comprehensive manner. Results Our in silico survey of microsatellite clustering in genomes of Homo sapiens, Maccaca mulatta, Mus musculus, Rattus norvegicus, Ornithorhynchus anatinus, Gallus gallus, Danio rerio and Drosophila melanogaster revealed an unexpected high abundance of compound microsatellites. About 4 – 25% of all microsatellites could be categorized as compound microsatellites. Compound microsatellites are approximately 15 times more frequent than expected under the assumption of a random distribution of microsatellites. Interestingly, microsatellites do not only tend to cluster but the adjacent repeat types of compound microsatellites have very similar motifs: in most cases (>90% these motifs differ only by a single mutation (base substitution or indel. We propose that the majority of the compound microsatellites originates by duplication of imperfections in a microsatellite tract. This process occurs mostly at the end of a microsatellite, leading to a new repeat type and a potential microsatellite repeat track. Conclusion Our findings suggest a more dynamic picture of microsatellite evolution than previously believed. Imperfections within microsatellites might not only cause the "death" of microsatellites they might also result in their "birth".

  10. Socioeconomic inequality in clusters of health-related behaviours in Europe: latent class analysis of a cross-sectional European survey.

    Science.gov (United States)

    Kino, Shiho; Bernabé, Eduardo; Sabbah, Wael

    2017-05-23

    Modifiable health-related behaviours tend to cluster among most vulnerable sectors of the population, particularly those at the bottom of the social hierarchy. This study aimed to identify the clusters of health-related behaviours in 27 European countries and to examine the socioeconomic inequalities in these clusters. Data were from Eurobarometer 72.3-2009, a cross-sectional survey of 27 European countries. The analyses were conducted in 2016. The main sections of the survey included questions pertaining to sociodemographic factors, health-related behaviours, and use of services. In this study, those aged 18 years and older were included. We selected five health-related behaviours, namely smoking, excessive alcohol consumption, frequent fresh fruit consumption, physical activity and dental check-ups. Socioeconomic position was indicated by education, subjective social status and difficulty in paying bills. Latent class analysis was conducted to explore the clusters of these five behaviours. Multinomial logistic regression model was used to examine the relationships between the clusters and socioeconomic positions adjusting for age, gender, marital status and urbanisation. The eligible total population was 23,842. Latent class analysis identified three clusters; healthy, moderate and risky clusters in this European population. Individuals with the lowest socioeconomic position were more likely to have risky and moderate clusters than healthy cluster compared to those with the highest socioeconomic position. There were clear socioeconomic gradients in clusters of health-related behaviours. The findings highlight the importance of adopting interventions that address multiple health risk behaviours and policies that tackle the social determinants of health-related behaviours.

  11. A homogeneous photometric and spectroscopic survey of open clusters in the Perseus Arm

    Science.gov (United States)

    Marco, Amparo; Negueruela, Ignacio; Monguió, Maria

    2015-08-01

    We are carrying out a homogeneous photometric survey of all young (Isaac Newton Telescope in La Palma. We intend to derive relative ages and distances with typical accuracies of 5 Ma and 200 pc. Our data will allow us to test the predictions of different models for the main mechanism producing the spiral structure of the Milky Way. In addition, we will enormously improve our knowledge of stellar evolution for stars in the 6-15 Msolar range. Moreover, the huge dataset of homogeneous photometry for thousands of stars (including ~2000 B-type stars) will have an enormous legacy value

  12. Hand washing behavior and associated factors in Vietnam based on the Multiple Indicator Cluster Survey, 2010–2011

    Directory of Open Access Journals (Sweden)

    Kien Gia To

    2016-02-01

    Full Text Available Background: Handwashing is a cost-effective way of preventing communicable diseases such as respiratory and food-borne illnesses. However, handwashing rates are low in developing countries. Target 7C of the seventh Millennium Development Goals was to increase by half the proportion of people with sustainable access to safe drinking water and basic sanitation by 2015. Studies have found that better access to improved water sources and sanitation is associated with higher rates of handwashing. Objective: Our goal was to describe handwashing behaviour and identify the associated factors in Vietnamese households. Design: Data from 12,000 households participating in the Vietnam Multiple Indicator Cluster Survey 2011 were used. The survey used a multistage sampling method to randomly select 100 clusters and 20 households per cluster. Self-administered questionnaires were used to collect data from a household representative. Demographic variables, the presence of a specific place for handwashing, soap and water, access to improved sanitation, and access to improved water sources were tested for association with handwashing behaviour in logistic regression. Results: Almost 98% of households had a specific place for handwashing, and 85% had cleansing materials and water at such a place. The prevalence of handwashing in the sample was almost 85%. Educational level, ethnicity of the household head, and household wealth were factors associated with handwashing practice (p<0.05. Those having access to an improved sanitation facility were more likely to practise handwashing [odds ratio (OR=1.69, 95% confidence interval (CI: 1.37–2.09, p<0.001], as were those with access to improved water sources (OR=1.74, 95% CI: 1.37–2.21, p<0.001. Conclusions: Households with low education, low wealth, belonging to ethnic minorities, and with low access to improved sanitation facilities and water sources should be targeted for interventions implementing handwashing

  13. The Australian longitudinal study on male health sampling design and survey weighting: implications for analysis and interpretation of clustered data.

    Science.gov (United States)

    Spittal, Matthew J; Carlin, John B; Currier, Dianne; Downes, Marnie; English, Dallas R; Gordon, Ian; Pirkis, Jane; Gurrin, Lyle

    2016-10-31

    The Australian Longitudinal Study on Male Health (Ten to Men) used a complex sampling scheme to identify potential participants for the baseline survey. This raises important questions about when and how to adjust for the sampling design when analyzing data from the baseline survey. We describe the sampling scheme used in Ten to Men focusing on four important elements: stratification, multi-stage sampling, clustering and sample weights. We discuss how these elements fit together when using baseline data to estimate a population parameter (e.g., population mean or prevalence) or to estimate the association between an exposure and an outcome (e.g., an odds ratio). We illustrate this with examples using a continuous outcome (weight in kilograms) and a binary outcome (smoking status). Estimates of a population mean or disease prevalence using Ten to Men baseline data are influenced by the extent to which the sampling design is addressed in an analysis. Estimates of mean weight and smoking prevalence are larger in unweighted analyses than weighted analyses (e.g., mean = 83.9 kg vs. 81.4 kg; prevalence = 18.0 % vs. 16.7 %, for unweighted and weighted analyses respectively) and the standard error of the mean is 1.03 times larger in an analysis that acknowledges the hierarchical (clustered) structure of the data compared with one that does not. For smoking prevalence, the corresponding standard error is 1.07 times larger. Measures of association (mean group differences, odds ratios) are generally similar in unweighted or weighted analyses and whether or not adjustment is made for clustering. The extent to which the Ten to Men sampling design is accounted for in any analysis of the baseline data will depend on the research question. When the goals of the analysis are to estimate the prevalence of a disease or risk factor in the population or the magnitude of a population-level exposure-outcome association, our advice is to adopt an analysis that respects the

  14. The Australian longitudinal study on male health sampling design and survey weighting: implications for analysis and interpretation of clustered data

    Directory of Open Access Journals (Sweden)

    Matthew J. Spittal

    2016-10-01

    Full Text Available Abstract Background The Australian Longitudinal Study on Male Health (Ten to Men used a complex sampling scheme to identify potential participants for the baseline survey. This raises important questions about when and how to adjust for the sampling design when analyzing data from the baseline survey. Methods We describe the sampling scheme used in Ten to Men focusing on four important elements: stratification, multi-stage sampling, clustering and sample weights. We discuss how these elements fit together when using baseline data to estimate a population parameter (e.g., population mean or prevalence or to estimate the association between an exposure and an outcome (e.g., an odds ratio. We illustrate this with examples using a continuous outcome (weight in kilograms and a binary outcome (smoking status. Results Estimates of a population mean or disease prevalence using Ten to Men baseline data are influenced by the extent to which the sampling design is addressed in an analysis. Estimates of mean weight and smoking prevalence are larger in unweighted analyses than weighted analyses (e.g., mean = 83.9 kg vs. 81.4 kg; prevalence = 18.0 % vs. 16.7 %, for unweighted and weighted analyses respectively and the standard error of the mean is 1.03 times larger in an analysis that acknowledges the hierarchical (clustered structure of the data compared with one that does not. For smoking prevalence, the corresponding standard error is 1.07 times larger. Measures of association (mean group differences, odds ratios are generally similar in unweighted or weighted analyses and whether or not adjustment is made for clustering. Conclusions The extent to which the Ten to Men sampling design is accounted for in any analysis of the baseline data will depend on the research question. When the goals of the analysis are to estimate the prevalence of a disease or risk factor in the population or the magnitude of a population-level exposure

  15. A SPITZER IRS SURVEY OF NGC 1333: INSIGHTS INTO DISK EVOLUTION FROM A VERY YOUNG CLUSTER

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, L. A.; Watson, Dan M.; Kim, K. H.; Manoj, P.; Remming, I.; Sheehan, P.; Forrest, W. J.; Mamajek, E. [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States); Adame, L.; McClure, M. [Department of Astronomy, University of Michigan, 500 Church Street, Dennison Building, Ann Arbor, MI 48109 (United States); Furlan, E. [Jet Propulsion Laboratory, California Institute of Technology, Mail Stop 264-723, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Espaillat, C. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-78, Cambridge, MA 02138 (United States); Ausfeld, K.; Rapson, V. A., E-mail: laa@pas.rochester.edu, E-mail: dmw@pas.rochester.edu [Center for Imaging Science, Rochester Institute of Technology, 54 Lomb Memorial Drive, Rochester, NY 14623 (United States)

    2012-08-01

    We report on the {lambda} = 5-36 {mu}m Spitzer Infrared Spectrograph (IRS) spectra of 79 young stellar objects in the very young nearby cluster NGC 1333. NGC 1333's youth enables the study of early protoplanetary disk properties, such as the degree of settling and the formation of gaps and clearings. We construct spectral energy distributions (SEDs) using our IRS data as well as published photometry and classify our sample into SED classes. Using 'extinction-free' spectral indices, we determine whether the disk, envelope, or photosphere dominates the spectrum. We analyze the dereddened spectra of objects that show disk-dominated emission using spectral indices and properties of silicate features in order to study the vertical and radial structure of protoplanetary disks in NGC 1333. At least nine objects in our sample of NGC 1333 show signs of large (several AU) radial gaps or clearings in their inner disk. Disks with radial gaps in NGC 1333 show more nearly pristine silicate dust than their radially continuous counterparts. We compare properties of disks in NGC 1333 to those in three other well-studied regions, Taurus-Auriga, Ophiuchus, and Chamaeleon I, and find no difference in their degree of sedimentation and dust processing.

  16. A combination of lacunary polyoxometalates and high-nuclear transition-metal clusters under hydrothermal conditions. Part II: From double cluster, dimer, and tetramer to three-dimensional frameworks.

    Science.gov (United States)

    Zhao, Jun-Wei; Jia, Hong-Peng; Zhang, Jie; Zheng, Shou-Tian; Yang, Guo-Yu

    2007-01-01

    The hydrothermal reactions of trivacant Keggin A-alpha-XW(9)O(34) polyoxoanions (X=P(V)/Si(IV)) with transition-metal ions (Ni(II)/Cu(II)/Fe(II)) in the presence of amines result in eight novel high-nuclear transition-metal-substituted polyoxotungstates [{Ni(7)(mu(3)-OH)(3)O(2)(dap)(3)(H(2)O)(6)}(B-alpha-PW(9)O(34))][{Ni(6)(mu(3)-OH)(3)(dap)(3)(H(2)O)(6)}(B-alpha-PW(9)O(34))][Ni(dap)(2)(H(2)O)(2)]4.5 H(2)O (1), [Cu(dap)(H(2)O)(3)](2)[{Cu(8)(dap)(4)(H(2)O)(2)}(B-alpha-SiW(9)O(34))(2)]6 H(2)O (2), (enH(2))(3)H(15)[{Fe(II) (1.5)Fe(III) (12)(mu(3)-OH)(12)(mu(4)-PO(4))(4)}(B-alpha-PW(9)O(34))(4)]ca.130 H(2)O (3), [{Cu(6)(mu(3)-OH)(3)(en)(3) (H(2)O)(3)}(B-alpha-PW(9)O(34))]7 H(2)O (4), [{Ni(6)(mu(3)-OH)(3)(en)(3)(H(2)O)(6)}(B-alpha-PW(9)O(34))]7 H(2)O (5), [{Ni(6)(mu(3)-OH)(3)(en)(2)(H(2)O)(8)}(B-alpha-PW(9)O(34))]7 H(2)O (6), [{Ni(6)(mu(3)-OH)(3)(dap)(2)(H(2)O)(8)}(B-alpha-PW(9)O(34))] 7 H(2)O (7), and [{Ni(6)(mu(3)-OH)(3)(en)(3)(H(2)O)(6)}(B-alpha-SiW(9)O(34))][Ni(0.5)(en)] 3.5 H(2)O (8) (en=ethylenediamine, dap=1,2-diaminopropane). These compounds have been structurally characterized by elemental analyses, IR spectra, diffuse reflectance spectra, thermogravimatric analysis, and X-ray crystallography. The double-cluster complex of phosphotungstate 1 simultaneously contains hepta- and hexa-Ni(II)-substituted trivacant Keggin units [{Ni(7)(mu(3)-OH)(3)O(2)(dap)(3)(H(2)O)(6)}(B-alpha-PW(9)O(34))](2-) and [{Ni(6)(mu(3)-OH)(3)(dap)(3)(H(2)O)(6)}(B-alpha-PW(9)O(34))]. The dimeric silicotungstate 2 is built up from two trivacant Keggin [B-alpha-SiW(9)O(34)](10-) fragments linked by an octa-Cu(II) cluster. The main skeleton of 3 is a tetrameric cluster constructed from four tri-Fe(III)-substituted [Fe(III) (3)(mu(3)-OH)(3)(B-alpha-PW(9) O(34))](3-) Keggin units linked by a central Fe(II) (4)O(4) cubane core and four mu(4)-PO(4) bridges. Complex 4 is an unprecedented three-dimensional extended architecture with hexagonal channels built by hexa-Cu(II) clusters and trivacant

  17. Epidermolytic hyperkeratosis (bullous congenital ichthyosiform erythroderma). Genetic linkage to chromosome 12q in the region of the type II keratin gene cluster.

    Science.gov (United States)

    Pulkkinen, L; Christiano, A M; Knowlton, R G; Uitto, J

    1993-01-01

    Epidermolytic hyperkeratosis (EHK) is an autosomal dominant genodermatosis characterized by hyperkeratosis and blistering of the skin. Histopathology demonstrates suprabasilar blister formation with aggregation of tonofilaments. In this study, we tested the hypothesis that the EHK phenotype is linked to one of the suprabasilar keratins (KRT10 or KRT1) present in the types I and II keratin gene clusters in chromosomes 17q and 12q, respectively. For this purpose, Southern hybridizations were performed with DNA from a large kindred with EHK, consisting of 11 affected individuals in three generations. Segregation analysis with markers flanking the keratin gene clusters demonstrated linkage (Z = 3.61 at theta = 0) to a locus on 12q, while markers on 17q were excluded. These data implicate KRT1, the type II keratin expressed in suprabasilar keratinocytes, as a candidate gene in this family with EHK. Images PMID:7678607

  18. Theoretical study on the structural properties and relative stability of M(II)-Al layered double hydroxides based on a cluster model.

    Science.gov (United States)

    Yan, Hong; Wei, Min; Ma, Jing; Li, Feng; Evans, David G; Duan, Xue

    2009-05-28

    The [M2Al(OH2)9(OH)4]3+ clusters (M = divalent cation Mg2+, Ca2+, Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+, or Cd2+), which include the basic information of layered double hydroxides (LDHs) lattice structure with the most economical size, have been investigated by density functional theory (DFT) to shed light on the structural properties and relative stability of M(II)-Al binary LDHs layers with a M2+/Al3+ ratio of 2. The geometric parameters (bond distance and bond angle), natural bond orbitals (NBO), stretching vibration frequencies of three-centered bridging OH groups (nu(O3-H)), as well as binding energy of the cluster model were systematically studied. It was found that the geometries and the nu(O3-H) frequency for the calculated clusters are remarkably influenced by the electronic structure of the divalent cations, such as valence electronic configuration, natural bond orbitals, natural charge transfer, and bond order. The calculated binding energies are in good agreement with the relative stability of the experimental results for the corresponding LDHs. The calculation results reveal that the 2Ni-Al cluster shows the highest stability among the open-shelled cation-containing clusters, while the stability of the 2Cu-Al cluster is the weakest; the 2Mg-Al and 2Zn-Al clusters are the most stable ones among the closed-shelled cation-containing clusters. These findings are in high accordance with the experimental results. Therefore, this work provides a detailed understanding of how the electronic structure of cations plays a more significant role in the structural properties and relative stability of the corresponding LDHs layers rather than ionic size.

  19. Perturbation of the Quinone-binding Site of Complex II Alters the Electronic Properties of the Proximal [3Fe-4S] Iron-Sulfur Cluster*

    Science.gov (United States)

    Ruprecht, Jonathan; Iwata, So; Rothery, Richard A.; Weiner, Joel H.; Maklashina, Elena; Cecchini, Gary

    2011-01-01

    Succinate-ubiquinone oxidoreductase (SQR) and menaquinol-fumarate oxidoreductase (QFR) from Escherichia coli are members of the complex II family of enzymes. SQR and QFR catalyze similar reactions with quinones; however, SQR preferentially reacts with higher potential ubiquinones, and QFR preferentially reacts with lower potential naphthoquinones. Both enzymes have a single functional quinone-binding site proximal to a [3Fe-4S] iron-sulfur cluster. A difference between SQR and QFR is that the redox potential of the [3Fe-4S] cluster in SQR is 140 mV higher than that found in QFR. This may reflect the character of the different quinones with which the two enzymes preferentially react. To investigate how the environment around the [3Fe-4S] cluster affects its redox properties and catalysis with quinones, a conserved amino acid proximal to the cluster was mutated in both enzymes. It was found that substitution of SdhB His-207 by threonine (as found in QFR) resulted in a 70-mV lowering of the redox potential of the cluster as measured by EPR. The converse substitution in QFR raised the redox potential of the cluster. X-ray structural analysis suggests that placing a charged residue near the [3Fe-4S] cluster is a primary reason for the alteration in redox potential with the hydrogen bonding environment having a lesser effect. Steady state enzyme kinetic characterization of the mutant enzymes shows that the redox properties of the [3Fe-4S] cluster have only a minor effect on catalysis. PMID:21310949

  20. The Grism Lens-Amplified Survey from Space (GLASS). VIII. The Influence of the Cluster Properties on Hα Emitter Galaxies at 0.3 < z < 0.7

    Science.gov (United States)

    Vulcani, Benedetta; Treu, Tommaso; Nipoti, Carlo; Schmidt, Kasper B.; Dressler, Alan; Morshita, Takahiro; Poggianti, Bianca M.; Malkan, Matthew; Hoag, Austin; Bradač, Marusa; Abramson, Louis; Trenti, Michele; Pentericci, Laura; von der Linden, Anja; Morris, Glenn; Wang, Xin

    2017-03-01

    Exploiting the data of the Grism Lens-Amplified Survey from Space (GLASS), we characterize the spatial distribution of star formation in 76 highly active star-forming galaxies in 10 clusters at 0.3< z< 0.7. All of these galaxies are likely restricted to first infall. In a companion paper, we contrast the properties of field and cluster galaxies, whereas here we correlate the properties of Hα emitters to a number of tracers of the cluster environment to investigate its role in driving galaxy transformations. Hα emitters are found in the clusters out to 0.5 virial radii, the maximum radius covered by GLASS. The peak of the Hα emission is offset with respect to the peak of the UV continuum. We decompose these offsets into a radial and a tangential component. The radial component points away from the cluster center in 60% of the cases, with 95% confidence. The decompositions agree with cosmological simulations; that is, the Hα emission offset correlates with galaxy velocity and ram-pressure stripping signatures. Trends between Hα emitter properties and surface mass density distributions and X-ray emissions emerge only for unrelaxed clusters. The lack of strong correlations with the global environment does not allow us to identify a unique environmental effect originating from the cluster center. In contrast, correlations between Hα morphology and local number density emerge. We conclude that local effects, uncorrelated to the cluster-centric radius, play a more important role in shaping galaxy properties.

  1. Cross-correlation of galaxies and galaxy clusters in the Sloan Digital Sky Survey and the importance of non-Poissonian shot noise

    Science.gov (United States)

    Paech, Kerstin; Hamaus, Nico; Hoyle, Ben; Costanzi, Matteo; Giannantonio, Tommaso; Hagstotz, Steffen; Sauerwein, Georg; Weller, Jochen

    2017-09-01

    We present measurements of angular cross power spectra between galaxies and optically-selected galaxy clusters in the final photometric sample of the Sloan Digital Sky Survey (SDSS). We measure the autocorrelations and cross correlations between galaxy and cluster samples, from which we extract the effective biases and study the shot noise properties. We model the non-Poissonian shot noise by introducing an effective number density of tracers and fit for this quantity. We find that we can only describe the cross-correlation of galaxies and galaxy clusters, as well as the autocorrelation of galaxy clusters, on the relevant scales using a non-Poissonian shot noise contribution. The values of effective bias we finally measure for a volume-limited sample are bcc = 4.09 ± 0.47 for the cluster autocorrelation and bgc = 2.15 ± 0.09 for the galaxy-cluster cross-correlation. We find that these results are consistent with expectations from the autocorrelations of galaxies and clusters and are in good agreement with previous studies. The main result is two-fold: first we provide a measurement of the cross-correlation of galaxies and clusters, which can be used for further cosmological analysis; and secondly we describe an effective treatment of the shot noise.

  2. On the activation energy for the formation of a critical size water cluster in structure I and structure II gas hydrates

    OpenAIRE

    Høvring, Eirik

    2012-01-01

    Master's thesis in Petroleum engineering In the present thesis, experiments have been performed in order to study the activation energy for the formation of a stable, critical size water cluster in structure I and structure II gas hydrates. This activation energy represents an energy barrier for the nucleation process forming the required particle (nuclei) size to trigger macroscopic hydrate growth. The experiments were carried out in different laboratory high pressure cells, but of eq...

  3. On the activation energy for the formation of a critical size water cluster in structure I and structure II gas hydrates

    OpenAIRE

    Høvring, Eirik

    2012-01-01

    In the present thesis, experiments have been performed in order to study the activation energy for the formation of a stable, critical size water cluster in structure I and structure II gas hydrates. This activation energy represents an energy barrier for the nucleation process forming the required particle (nuclei) size to trigger macroscopic hydrate growth. The experiments were carried out in different laboratory high pressure cells, but of equal size and geometry. Studies were conducte...

  4. Epidermolytic hyperkeratosis (bullous congenital ichthyosiform erythroderma). Genetic linkage to chromosome 12q in the region of the type II keratin gene cluster.

    OpenAIRE

    Pulkkinen, L.; Christiano, A M; Knowlton, R G; Uitto, J

    1993-01-01

    Epidermolytic hyperkeratosis (EHK) is an autosomal dominant genodermatosis characterized by hyperkeratosis and blistering of the skin. Histopathology demonstrates suprabasilar blister formation with aggregation of tonofilaments. In this study, we tested the hypothesis that the EHK phenotype is linked to one of the suprabasilar keratins (KRT10 or KRT1) present in the types I and II keratin gene clusters in chromosomes 17q and 12q, respectively. For this purpose, Southern hybridizations were pe...

  5. Progress on maternal health care in Vietnam: Findings from Vietnam Multiple Indicator Cluster Survey 2000, 2006, 2011, and 2014.

    Science.gov (United States)

    Chuong, Nguyen Canh; Van Minh, Hoang; Thi Thuy Duong, Doan; Duc, Duong Minh; Anh Dao, Le Thi; Duy Anh, Nguyen

    2017-11-21

    This paper aims to describe a trend in coverage of maternal care services, and provides a detailed analysis of socio-economic correlations to the existing inequities. The paper uses data from the Vietnam Multiple Indicator Cluster Survey 2000, 2006, 2011, and 2014. In the MICS, there were 9,117 women in 2000, 9,473 women in 2006, 11,614 women in 2011, and 9,827 women in 2014 participated in. We found the coverage of antenatal care increase from 68.6% in 2000 to 95.9% in 2014. Similarly, the percentages of women who gave birth with the assistance of skilled staff increased during the studied period ( from 69.9% in 2000, 87.7% to 94.5% in 2014). However, improvements in antenatal care and skilled birth attendance in Vietnam have been uneven across different segments of the population. In all the four surveys, the proportions of women who received ANC by a skilled staff and percentages of women who gave birth with the assistance of a skilled health personnel were much higher among those with higher education, belonged to Kinh majority tribe, had better economic status, and lived in an urban area. The degrees of inequity in both antenatal and delivery care in Vietnam are likely to increase over time.

  6. Exome sequencing identifies NFS1 deficiency in a novel Fe-S cluster disease, infantile mitochondrial complex II/III deficiency.

    Science.gov (United States)

    Farhan, Sali M K; Wang, Jian; Robinson, John F; Lahiry, Piya; Siu, Victoria M; Prasad, Chitra; Kronick, Jonathan B; Ramsay, David A; Rupar, C Anthony; Hegele, Robert A

    2014-01-01

    Iron-sulfur (Fe-S) clusters are a class of highly conserved and ubiquitous prosthetic groups with unique chemical properties that allow the proteins that contain them, Fe-S proteins, to assist in various key biochemical pathways. Mutations in Fe-S proteins often disrupt Fe-S cluster assembly leading to a spectrum of severe disorders such as Friedreich's ataxia or iron-sulfur cluster assembly enzyme (ISCU) myopathy. Herein, we describe infantile mitochondrial complex II/III deficiency, a novel autosomal recessive mitochondrial disease characterized by lactic acidemia, hypotonia, respiratory chain complex II and III deficiency, multisystem organ failure and abnormal mitochondria. Through autozygosity mapping, exome sequencing, in silico analyses, population studies and functional tests, we identified c.215G>A, p.Arg72Gln in NFS1 as the likely causative mutation. We describe the first disease in man likely caused by deficiency in NFS1, a cysteine desulfurase that is implicated in respiratory chain function and iron maintenance by initiating Fe-S cluster biosynthesis. Our results further demonstrate the importance of sufficient NFS1 expression in human physiology.

  7. The XXL Survey. XII. Optical spectroscopy of X-ray-selected clusters and the frequency of AGN in superclusters

    Science.gov (United States)

    Koulouridis, E.; Poggianti, B.; Altieri, B.; Valtchanov, I.; Jaffé, Y.; Adami, C.; Elyiv, A.; Melnyk, O.; Fotopoulou, S.; Gastaldello, F.; Horellou, C.; Pierre, M.; Pacaud, F.; Plionis, M.; Sadibekova, T.; Surdej, J.

    2016-06-01

    Context. This article belongs to the first series of XXL publications. It presents multifibre spectroscopic observations of three 0.55 deg2 fields in the XXL Survey, which were selected on the basis of their high density of X-ray-detected clusters. The observations were obtained with the AutoFib2+WYFFOS (AF2) wide-field fibre spectrograph mounted on the 4.2 m William Herschel Telescope. Aims: The paper first describes the scientific rationale, the preparation, the data reduction, and the results of the observations, and then presents a study of active galactic nuclei (AGN) within three superclusters. Methods: To determine the redshift of galaxy clusters and AGN, we assign high priority to a) the brightest cluster galaxies (BCGs), b) the most probable cluster galaxy candidates, and c) the optical counterparts of X-ray point-like sources. We use the outcome of the observations to study the projected (2D) and the spatial (3D) overdensity of AGN in three superclusters. Results: We obtained redshifts for 455 galaxies in total, 56 of which are counterparts of X-ray point-like sources. We were able to determine the redshift of the merging supercluster XLSSC-e, which consists of six individual clusters at z ~ 0.43, and we confirmed the redshift of supercluster XLSSC-d at z ~ 0.3. More importantly, we discovered a new supercluster, XLSSC-f, that comprises three galaxy clusters also at z ~ 0.3. We find a significant 2D overdensity of X-ray point-like sources only around the supercluster XLSSC-f. This result is also supported by the spatial (3D) analysis of XLSSC-f, where we find four AGN with compatible spectroscopic redshifts and possibly one more with compatible photometric redshift. In addition, we find two AGN (3D analysis) at the redshift of XLSSC-e, but no AGN in XLSSC-d. Comparing these findings with the optical galaxy overdensity we conclude that the total number of AGN in the area of the three superclusters significantly exceeds the field expectations. All of the

  8. A survey on bio inspired meta heuristic based clustering protocols for wireless sensor networks

    Science.gov (United States)

    Datta, A.; Nandakumar, S.

    2017-11-01

    Recent studies have shown that utilizing a mobile sink to harvest and carry data from a Wireless Sensor Network (WSN) can improve network operational efficiency as well as maintain uniform energy consumption by the sensor nodes in the network. Due to Sink mobility, the path between two sensor nodes continuously changes and this has a profound effect on the operational longevity of the network and a need arises for a protocol which utilizes minimal resources in maintaining routes between the mobile sink and the sensor nodes. Swarm Intelligence based techniques inspired by the foraging behavior of ants, termites and honey bees can be artificially simulated and utilized to solve real wireless network problems. The author presents a brief survey on various bio inspired swarm intelligence based protocols used in routing data in wireless sensor networks while outlining their general principle and operation.

  9. Measuring human rights violations in a conflict-affected country: results from a nationwide cluster survey in Central African Republic

    Directory of Open Access Journals (Sweden)

    Roberts Les

    2011-03-01

    Full Text Available Abstract Background Measuring human rights violations is particularly challenging during or after armed conflict. A recent nationwide survey in the Central African Republic produced estimates of rates of grave violations against children and adults affected by armed conflict, using an approach known as the "Neighborhood Method". Methods In June and July, 2009, a random household survey was conducted based on population estimates from the 2003 national census. Clusters were assigned systematically proportional to population size. Respondents in randomly selected households were interviewed regarding incidents of killing, intentional injury, recruitment into armed groups, abduction, sexual abuse and rape between January 1, 2008 and the date of interview, occurring in their homes' and those of their three closest neighbors. Results Sixty of the selected 69 clusters were surveyed. In total, 599 women were interviewed about events in 2,370 households representing 13,669 persons. Estimates of annual rates of each violation occurring per 1000 people in each of two strata are provided for children between the ages of five and 17, adults 18 years of age and older and the entire population five years and older, along with a combined and weighted national rate. The national rates for children age five to 17 were estimated to be 0.98/1000/year (95% CI: 0.18 - 1.78 for recruitment, 2.56/1000/year (95% CI: 1.50 - 3.62 for abduction, 1.13/1000/year (95% CI: 0.33 - 1.93 for intentional injury, 10.72/1000 girls/year (95% CI: 7.40 - 14.04 for rape, and 4.80/1000 girls/year (95% CI: 2.61 - 6.00 for sexual abuse. No reports of any violation against a person under the age of five were recorded and there were no reports of rape or sexual abuse of males. No children were reported to have been killed during the recall period. Rape and abduction were the most frequently reported events. Conclusions The population-based figures greatly augment existing information on

  10. The GALAH survey

    DEFF Research Database (Denmark)

    Kos, Janez; Bland-Hawthor, Joss; Freeman, Ken

    2018-01-01

    The technique of chemical tagging uses the elemental abundances of stellar atmospheres to 'reconstruct' chemically homogeneous star clusters that have long since dispersed. The GALAH spectroscopic survey - which aims to observe one million stars using the Anglo-Australian Telescope - allows us......-SNE) - which identifies an optimal mapping of a high-dimensional space into fewer dimensions - whilst conserving the original clustering information. Typically, the projection is made to a 2D space to aid recognition of clusters by eye. We show that this method is a reliable tool for chemical tagging because...... it can: (i) resolve clustering in chemical space alone, (ii) recover known open and globular clusters with high efficiency and low contamination, and (iii) relate field stars to known clusters. t-SNE also provides a useful visualization of a high-dimensional space. We demonstrate the method on a data set...

  11. Multiple vulnerabilities and maternal healthcare in Vietnam: findings from the Multiple Indicator Cluster Surveys, 2000, 2006, and 2011

    Directory of Open Access Journals (Sweden)

    Hoang Van Minh

    2016-02-01

    Full Text Available Background: Knowledge of the aggregate effects of multiple socioeconomic vulnerabilities is important for shedding light on the determinants of growing health inequalities and inequities in maternal healthcare. Objective: This paper describes patterns of inequity in maternal healthcare utilization and analyzes associations between inequity and multiple socioeconomic vulnerabilities among women in Vietnam. Design: This is a repeated cross-sectional study using data from the Vietnam Multiple Indicator Cluster Surveys 2000, 2006, and 2011. Two maternal healthcare indicators were selected: (1 skilled antenatal care and (2 skilled delivery care. Four types of socioeconomic vulnerabilities – low education, ethnic minority, poverty, and rural location – were assessed both as separate explanatory variables and as composite indicators (combinations of three and four vulnerabilities. Pairwise comparisons and adjusted odds ratios were used to assess socioeconomic inequities in maternal healthcare. Results: In all three surveys, there were increases across the survey years in both the proportions of women who received antenatal care by skilled staff (68.6% in 2000, 90.8% in 2006, and 93.7% in 2011 and the proportions of women who gave birth with assistance from skilled staff (69.9% in 2000, 87.7% in 2006, and 92.9% in 2011. The receipt of antenatal care by skilled staff and birth assistance from skilled health personnel were less common among vulnerable women, especially those with multiple vulnerabilities. Conclusions: Even though Vietnam has improved its coverage of maternal healthcare on average, policies should target maternal healthcare utilization among women with multiple socioeconomic vulnerabilities. Both multisectoral social policies and health policies are needed to tackle multiple vulnerabilities more effectively by identifying those who are poor, less educated, live in rural areas, and belong to ethnic minority groups.

  12. The “UV-route” to Search for Blue Straggler Stars in Globular Clusters: First Results from the HST UV Legacy Survey

    Energy Technology Data Exchange (ETDEWEB)

    Raso, S.; Ferraro, F. R.; Lanzoni, B. [Department of Physics and Astronomy, University of Bologna, Viale Berti Pichat, 6/2, Bologna (Italy); Dalessandro, E. [INAF Osservatorio Astronomico di Bologna, Via Ranzani 1, Bologna (Italy); Nardiello, D. [Department of Physics and Astronomy Galileo Galilei, University of Padova, Vicolo dell’Osservatorio 3, I-35122 Padova (Italy); Bellini, A. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Vesperini, E. [Department of Astronomy, Indiana University, Bloomington, IN, 47401 (United States)

    2017-04-10

    We used data from the Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters to select the Blue Straggler Star (BSS) population in four intermediate/high density systems (namely NGC 2808, NGC 6388, NGC 6541, and NGC 7078) through a “UV-guided search.” This procedure consists of using the F275W images in each cluster to construct the master list of detected sources, and then force it to the images acquired in the other filters. Such an approach optimizes the detection of relatively hot stars and allows the detection of a complete sample of BSSs even in the central region of high-density clusters, because the light from the bright cool giants, which dominates the optical emission in old stellar systems, is sensibly reduced at UV wavelengths. Our UV-guided selections of BSSs have been compared to the samples obtained in previous, optical-driven surveys, clearly demonstrating the efficiency of the UV approach. In each cluster we also measured the parameter A {sup +}, defined as the area enclosed between the cumulative radial distribution of BSSs and that of a reference population, which traces the level of BSS central segregation and the level of dynamical evolution suffered by the system. The values measured for the four clusters studied in this paper nicely fall along the dynamical sequence recently presented for a sample of 25 clusters.

  13. Hydra II: A Faint and Compact Milky Way Dwarf Galaxy Found in the Survey of the Magellanic Stellar History

    NARCIS (Netherlands)

    Martin, Nicolas F.; Nidever, David L.; Besla, Gurtina; Olsen, Knut; Walker, Alistair R.; Vivas, A. Katherina; Gruendl, Robert A.; Kaleida, Catherine C.; Muñoz, Ricardo R.; Blum, Robert D.; Saha, Abhijit; Conn, Blair C.; Bell, Eric F.; Chu, You-Hua; Cioni, Maria-Rosa L.; de Boer, Thomas J. L.; Gallart, Carme; Jin, Shoko; Kunder, Andrea; Majewski, Steven R.; Martinez-Delgado, David; Monachesi, Antonela; Monelli, Matteo; Monteagudo, Lara; Noël, Noelia E. D.; Olszewski, Edward W.; Stringfellow, Guy S.; van der Marel, Roeland P.; Zaritsky, Dennis

    We present the discovery of a new dwarf galaxy, Hydra II, found serendipitously within the data from the ongoing Survey of the Magellanic Stellar History conducted with the Dark Energy Camera on the Blanco 4 m Telescope. The new satellite is compact ({{r}h}=68 ± 11 pc) and faint ({{M}V}=-4.8 ± 0.3),

  14. REDSHIFTS, SAMPLE PURITY, AND BCG POSITIONS FOR THE GALAXY CLUSTER CATALOG FROM THE FIRST 720 SQUARE DEGREES OF THE SOUTH POLE TELESCOPE SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Song, J. [Department of Physics, University of Michigan, 450 Church Street, Ann Arbor, MI 48109 (United States); Zenteno, A.; Desai, S.; Bazin, G. [Department of Physics, Ludwig-Maximilians-Universitaet, Scheinerstr. 1, D-81679 Muenchen (Germany); Stalder, B.; Ashby, M. L. N.; Bayliss, M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Bleem, L. E.; Benson, B. A.; Carlstrom, J. E.; Chang, C. L.; Crawford, T. M.; Crites, A. T. [Kavli Institute for Cosmological Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Aird, K. A. [Department of Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Armstrong, R. [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104 (United States); Bertin, E. [Institut d' Astrophysique de Paris, UMR 7095 CNRS, Universite Pierre et Marie Curie, 98 bis boulevard Arago, F-75014 Paris (France); Brodwin, M. [Department of Physics and Astronomy, University of Missouri, 5110 Rockhill Road, Kansas City, MO 64110 (United States); Cho, H. M. [NIST Quantum Devices Group, 325 Broadway Mailcode 817.03, Boulder, CO 80305 (United States); Clocchiatti, A. [Departamento de Astronomia y Astrosifica, Pontificia Universidad Catolica, Santiago (Chile); De Haan, T. [Department of Physics, McGill University, 3600 Rue University, Montreal, Quebec H3A 2T8 (Canada); and others

    2012-12-10

    We present the results of the ground- and space-based optical and near-infrared (NIR) follow-up of 224 galaxy cluster candidates detected with the Sunyaev-Zel'dovich (SZ) effect in the 720 deg{sup 2} of the South Pole Telescope (SPT) survey completed in the 2008 and 2009 observing seasons. We use the optical/NIR data to establish whether each candidate is associated with an overdensity of galaxies and to estimate the cluster redshift. Most photometric redshifts are derived through a combination of three different cluster redshift estimators using red-sequence galaxies, resulting in an accuracy of {Delta}z/(1 + z) = 0.017, determined through comparison with a subsample of 57 clusters for which we have spectroscopic redshifts. We successfully measure redshifts for 158 systems and present redshift lower limits for the remaining candidates. The redshift distribution of the confirmed clusters extends to z = 1.35 with a median of z{sub med} = 0.57. Approximately 18% of the sample with measured redshifts lies at z > 0.8. We estimate a lower limit to the purity of this SPT SZ-selected sample by assuming that all unconfirmed clusters are noise fluctuations in the SPT data. We show that the cumulative purity at detection significance {xi} > 5({xi} > 4.5) is {>=}95% ({>=}70%). We present the red brightest cluster galaxy (rBCG) positions for the sample and examine the offsets between the SPT candidate position and the rBCG. The radial distribution of offsets is similar to that seen in X-ray-selected cluster samples, providing no evidence that SZ-selected cluster samples include a different fraction of recent mergers from X-ray-selected cluster samples.

  15. X-Ray bright active galactic nuclei in massive galaxy clusters - II. The fraction of galaxies hosting active nuclei

    DEFF Research Database (Denmark)

    Ehlert, S.; von der Linden, A.; Allen, S. W.

    2013-01-01

    regions of the clusters that is~3 times lower than the field value. This fraction increases with clustercentric distance before becoming consistent with the field at ~2.5r500. Our data exhibit similar radial trends to those observed for star formation and optically selected AGN in cluster member galaxies...

  16. EROs found behind lensing clusters: II. Empirical properties, classification, and SED modelling based on multi-wavelength observations

    NARCIS (Netherlands)

    Hempel, A.; Schaerer, D.; Egami, E.; Pelló, R.; Wise, M.; Richard, J.; Le Borgne, J.F.; Kneib, J.P.

    2008-01-01

    Aims. We study the properties and nature of extremely red galaxies (FRO, R-K >= 5.6) found behind two lensing clusters and compare them with other known galaxy populations. Methods. New HST/ACS, Spitzer (TRAC and MIPS), and Chandra/ACIS observations of the two lensing clusters Abell 1835 and AC 114

  17. Membership, lithium and chromospheric activity of the young open clusters IC 2391, IC 2602 and IC 4665 from GES (Gaia-ESO Survey) observations

    Science.gov (United States)

    Gómez Garrido, M.; Montes, D.; Gutiérrez Albarrán, M. L.; Tabernero, H. M.; Gónzalez Hernández, J. I.; GES Survey Builders

    2017-03-01

    We conduct a comparative study of the main properties of the of the young open clusters IC 2391, IC 2602 and IC 4665, focusing on their membership, lithium abundance and level of chromospheric activity and possible accretion. We use the fundamental parameters (effective temperature, surface gravity, and radial velocity) delivered by the Gaia-ESO survey (GES - https://www.gaia-eso.eu/) consortium in the four internal data release (iDR4) to select the members of these clusters among the UVES and GIRAFFE spectroscopic observations. Chromospheric activity criterium, and iterative process between radial velocity distribution and lithium-temperature diagram are applied to determinate what objects are members or non members of the clusters. All this information allowed us to characterize the properties of the members of these clusters and identify some field contaminant lithium-rich giants.

  18. Low vaccination coverage of Greek Roma children amid economic crisis: national survey using stratified cluster sampling.

    Science.gov (United States)

    Papamichail, Dimitris; Petraki, Ioanna; Arkoudis, Chrisoula; Terzidis, Agis; Smyrnakis, Emmanouil; Benos, Alexis; Panagiotopoulos, Takis

    2017-04-01

    Research on Roma health is fragmentary as major methodological obstacles often exist. Reliable estimates on vaccination coverage of Roma children at a national level and identification of risk factors for low coverage could play an instrumental role in developing evidence-based policies to promote vaccination in this marginalized population group. We carried out a national vaccination coverage survey of Roma children. Thirty Roma settlements, stratified by geographical region and settlement type, were included; 7-10 children aged 24-77 months were selected from each settlement using systematic sampling. Information on children's vaccination coverage was collected from multiple sources. In the analysis we applied weights for each stratum, identified through a consensus process. A total of 251 Roma children participated in the study. A vaccination document was presented for the large majority (86%). We found very low vaccination coverage for all vaccines. In 35-39% of children 'minimum vaccination' (DTP3 and IPV2 and MMR1) was administered, while 34-38% had received HepB3 and 31-35% Hib3; no child was vaccinated against tuberculosis in the first year of life. Better living conditions and primary care services close to Roma settlements were associated with higher vaccination indices. Our study showed inadequate vaccination coverage of Roma children in Greece, much lower than that of the non-minority child population. This serious public health challenge should be systematically addressed, or, amid continuing economic recession, the gap may widen. Valid national estimates on important characteristics of the Roma population can contribute to planning inclusion policies.

  19. A multi-institutional survey evaluating patient related QA – phase II

    Directory of Open Access Journals (Sweden)

    Teichmann Tobias

    2017-09-01

    Full Text Available In phase I of the survey a planning intercomparison of patient-related QA was performed at 12 institutions. The participating clinics created phantom based IMRT and VMAT plans which were measured utilizing the ArcCheck diode array. Mobius3D (M3D was used in phase II. It acts as a secondary dose verification tool for patient-specific QA based on average linac beam data collected by Mobius Medical Systems. All Quasimodo linac plans will be analyzed for the continuation of the intercomparison. We aim to determine if Mobius3D is suited for use with diverse treatment techniques, if beam model customization is needed. Initially we computed first Mobius3D results by transferring all plans from phase I to our Mobius3D server. Because of some larger PTV mean dose differences we checked if output factor customization would be beneficial. We performed measurements and output factor correction to account for discrepancies in reference conditions. Compared to Mobius3D's preconfigured average beam data values, these corrected output factors differed by ±1.5% for field sizes between 7x7cm2 and 30x30cm2 and to −3.9% for 3x3cm2. Our method of correcting the output factors turns out good congruence to M3D's reference values for these medium field sizes.

  20. Bright Metal-Poor Stars from the Hamburg/ESO Survey. II. A Chemodynamical Analysis

    Science.gov (United States)

    Beers, Timothy C.; Placco, Vinicius M.; Carollo, Daniela; Rossi, Silvia; Lee, Young Sun; Frebel, Anna; Norris, John E.; Dietz, Sarah; Masseron, Thomas

    2017-01-01

    We obtain estimates of stellar atmospheric parameters for a previously published sample of 1777 relatively bright (9Hamburg/ESO Survey. The original Frebel et al. analysis of these stars was able to derive estimates of [Fe/H] and [C/Fe] only for a subset of the sample, due to limitations in the methodology then available. A new spectroscopic analysis pipeline has been used to obtain estimates of {T}{eff}, {log} g, [Fe/H], and [C/Fe] for almost the entire data set. This sample is very local—about 90% of the stars are located within 0.5 kpc of the Sun. We consider the chemodynamical properties of these stars in concert with a similarly local sample of stars from a recent analysis of the Bidelman and MacConnell “weak metal” candidates by Beers et al. We use this combined sample to identify possible members of the halo stream of stars suggested by Helmi et al. and Chiba & Beers, as well as stars that may be associated with stripped debris from the putative parent dwarf of the globular cluster Omega Centauri, suggested to exist by previous authors. We identify a clear increase in the cumulative frequency of carbon-enhanced metal-poor (CEMP) stars with declining metallicity, as well as an increase in the fraction of CEMP stars with distance from the Galactic plane, consistent with previous results. We also identify a relatively large number of CEMP stars with kinematics consistent with the metal-weak thick-disk population, with possible implications for its origin.

  1. The VLT-FLAMES Tarantula Survey. VII. A low velocity dispersion for the young massive cluster R136

    NARCIS (Netherlands)

    Hénault-Brunet, V.; Evans, C.J.; Sana, H.; Gieles, M.; Bastian, N.; Maíz Apellániz, J.; Markova, N.; Taylor, W.D.; Bressert, E.; Crowther, P.A.; van Loon, J.T.

    2012-01-01

    Detailed studies of resolved young massive star clusters are necessary to determine their dynamical state and evaluate the importance of gas expulsion and early cluster evolution. In an effort to gain insight into the dynamical state of the young massive cluster R136 and obtain the first measurement

  2. Injuries, Death, and Disability Associated with 11 Years of Conflict in Baghdad, Iraq: A Randomized Household Cluster Survey.

    Directory of Open Access Journals (Sweden)

    Riyadh Lafta

    Full Text Available The objective of this study was to characterize injuries, deaths, and disabilities arising during 11 years of conflict in Baghdad.Using satellite imagery and administrative population estimated size for Baghdad, 30 clusters were selected, proportionate to population size estimates. Interviews were conducted during April and May 2014 in 900 households containing 5148 persons. Details about injuries and disabilities occurring from 2003 through May 2014 and resultant disabilities were recorded.There were 553 injuries reported by Baghdad residents, 225 of which were intentional, and 328 unintentional. For intentional injuries, the fatality rate was 39.1% and the disability rate 56.0%. Gunshots where the major cause of injury through 2006 when blasts/explosions became the most common cause and remained so through 2014. Among unintentional injuries, the fatality rate was 7.3% and the disability rate 77.1%. The major cause of unintentional injuries was falls (131 which have increased dramatically since 2008, followed by traffic related injuries (81, which have steadily increased. The proportion of injuries ending in disabilities remained fairly constant through the survey period.Intentional injuries added substantially to the burden of unintentional injuries for the population. For Baghdad, the phases of the Iraqi conflict are reflected in the patterns of injuries and consequent deaths reported. The scale of injuries during conflict is most certainly under-reported. Difficulties recalling injuries in a survey covering 11 years is a limitation, but it is likely that minor injuries were under-reported more than severe injuries. The in- and out-migration of Baghdad populations likely had effects on the events reported which we could not measure or estimate. Damage to the health infrastructure and the flight of health workers may have contributed to mortality and morbidity. Civilian injuries as well as mortality should be measured during conflicts, though

  3. Injuries, Death, and Disability Associated with 11 Years of Conflict in Baghdad, Iraq: A Randomized Household Cluster Survey

    Science.gov (United States)

    Lafta, Riyadh; Al-Shatari, Sahar; Cherewick, Megan; Galway, Lindsay; Mock, Charles; Hagopian, Amy; Flaxman, Abraham; Takaro, Tim; Greer, Anna; Kushner, Adam; Burnham, Gilbert

    2015-01-01

    Background The objective of this study was to characterize injuries, deaths, and disabilities arising during 11 years of conflict in Baghdad. Methods Using satellite imagery and administrative population estimated size for Baghdad, 30 clusters were selected, proportionate to population size estimates. Interviews were conducted during April and May 2014 in 900 households containing 5148 persons. Details about injuries and disabilities occurring from 2003 through May 2014 and resultant disabilities were recorded. Findings There were 553 injuries reported by Baghdad residents, 225 of which were intentional, and 328 unintentional. For intentional injuries, the fatality rate was 39.1% and the disability rate 56.0%. Gunshots where the major cause of injury through 2006 when blasts/explosions became the most common cause and remained so through 2014. Among unintentional injuries, the fatality rate was 7.3% and the disability rate 77.1%. The major cause of unintentional injuries was falls (131) which have increased dramatically since 2008, followed by traffic related injuries (81), which have steadily increased. The proportion of injuries ending in disabilities remained fairly constant through the survey period. Interpretation Intentional injuries added substantially to the burden of unintentional injuries for the population. For Baghdad, the phases of the Iraqi conflict are reflected in the patterns of injuries and consequent deaths reported. The scale of injuries during conflict is most certainly under-reported. Difficulties recalling injuries in a survey covering 11 years is a limitation, but it is likely that minor injuries were under-reported more than severe injuries. The in- and out-migration of Baghdad populations likely had effects on the events reported which we could not measure or estimate. Damage to the health infrastructure and the flight of health workers may have contributed to mortality and morbidity. Civilian injuries as well as mortality should be

  4. Prevalence of surgical conditions in individuals aged more than 50 years: a cluster-based household survey in Sierra Leone.

    Science.gov (United States)

    Wong, Evan G; Kamara, Thaim B; Groen, Reinou S; Zogg, Cheryl K; Zenilman, Michael E; Kushner, Adam L

    2015-01-01

    With the demographic transition disproportionately affecting developing nations, the healthcare burden associated with the elderly is likely to be compounded by poor baseline surgical capacity in these settings. We sought to assess the prevalence of surgical disease and disability in the elderly population of Sierra Leone to guide future development strategies. A cluster randomized, cross-sectional household survey was carried out countrywide in Sierra Leone from January 9th to February 3rd 2012. Using a standardized questionnaire, household member demographics, deaths occurring during the previous 12 months, and presence of any current surgical condition were elucidated. A retrospective analysis of individuals aged 50 and over was performed. The survey included 1,843 households with a total of 3,645 respondents. Of these, 13.6 % (496/3,645) were aged over 50 years. Of the elderly individuals in our sample, 301 (60.7 %) reported a current surgical condition. Of current surgical disease identified among elderly individuals (n = 530), 349 (65.8 %) described it as disabling, and 223 (42.1 %) sought help from traditional medicine practitioners. Women (odds ratio [OR] 0.60; 95 % confidence interval [CI] 0.40-0.90) and individuals living in urban settings (OR 0.44, 95 % CI 0.26-0.75) were less likely to report a current surgical problem. Of the 230 elderly deaths in the previous year, 83 (36.1 %) reported a surgical condition in the week prior. The unmet burden of surgical disease is prevalent in the elderly in low-resource settings. This patient population is expected to grow significantly in the coming years, and more resources should be allocated to address their surgical needs.

  5. Injuries, Death, and Disability Associated with 11 Years of Conflict in Baghdad, Iraq: A Randomized Household Cluster Survey.

    Science.gov (United States)

    Lafta, Riyadh; Al-Shatari, Sahar; Cherewick, Megan; Galway, Lindsay; Mock, Charles; Hagopian, Amy; Flaxman, Abraham; Takaro, Tim; Greer, Anna; Kushner, Adam; Burnham, Gilbert

    2015-01-01

    The objective of this study was to characterize injuries, deaths, and disabilities arising during 11 years of conflict in Baghdad. Using satellite imagery and administrative population estimated size for Baghdad, 30 clusters were selected, proportionate to population size estimates. Interviews were conducted during April and May 2014 in 900 households containing 5148 persons. Details about injuries and disabilities occurring from 2003 through May 2014 and resultant disabilities were recorded. There were 553 injuries reported by Baghdad residents, 225 of which were intentional, and 328 unintentional. For intentional injuries, the fatality rate was 39.1% and the disability rate 56.0%. Gunshots where the major cause of injury through 2006 when blasts/explosions became the most common cause and remained so through 2014. Among unintentional injuries, the fatality rate was 7.3% and the disability rate 77.1%. The major cause of unintentional injuries was falls (131) which have increased dramatically since 2008, followed by traffic related injuries (81), which have steadily increased. The proportion of injuries ending in disabilities remained fairly constant through the survey period. Intentional injuries added substantially to the burden of unintentional injuries for the population. For Baghdad, the phases of the Iraqi conflict are reflected in the patterns of injuries and consequent deaths reported. The scale of injuries during conflict is most certainly under-reported. Difficulties recalling injuries in a survey covering 11 years is a limitation, but it is likely that minor injuries were under-reported more than severe injuries. The in- and out-migration of Baghdad populations likely had effects on the events reported which we could not measure or estimate. Damage to the health infrastructure and the flight of health workers may have contributed to mortality and morbidity. Civilian injuries as well as mortality should be measured during conflicts, though not currently

  6. Data Clustering

    Science.gov (United States)

    Wagstaff, Kiri L.

    2012-03-01

    On obtaining a new data set, the researcher is immediately faced with the challenge of obtaining a high-level understanding from the observations. What does a typical item look like? What are the dominant trends? How many distinct groups are included in the data set, and how is each one characterized? Which observable values are common, and which rarely occur? Which items stand out as anomalies or outliers from the rest of the data? This challenge is exacerbated by the steady growth in data set size [11] as new instruments push into new frontiers of parameter space, via improvements in temporal, spatial, and spectral resolution, or by the desire to "fuse" observations from different modalities and instruments into a larger-picture understanding of the same underlying phenomenon. Data clustering algorithms provide a variety of solutions for this task. They can generate summaries, locate outliers, compress data, identify dense or sparse regions of feature space, and build data models. It is useful to note up front that "clusters" in this context refer to groups of items within some descriptive feature space, not (necessarily) to "galaxy clusters" which are dense regions in physical space. The goal of this chapter is to survey a variety of data clustering methods, with an eye toward their applicability to astronomical data analysis. In addition to improving the individual researcher’s understanding of a given data set, clustering has led directly to scientific advances, such as the discovery of new subclasses of stars [14] and gamma-ray bursts (GRBs) [38]. All clustering algorithms seek to identify groups within a data set that reflect some observed, quantifiable structure. Clustering is traditionally an unsupervised approach to data analysis, in the sense that it operates without any direct guidance about which items should be assigned to which clusters. There has been a recent trend in the clustering literature toward supporting semisupervised or constrained

  7. Mesoscale structure of a morning sector ionospheric shear flow region determined by conjugate Cluster II and MIRACLE ground-based observations

    Directory of Open Access Journals (Sweden)

    O. Amm

    2003-08-01

    Full Text Available We analyse a conjunction event of the Cluster II spacecraft with the MIRACLE ground-based instrument net-work in northern Fennoscandia on 6 February 2001, between 23:00 and 00:00 UT. Shortly after the spacecraft were located at perigee, the Cluster II satellites’ magnetic footpoints move northwards over Scandinavia and Svalbard, almost perfectly aligned with the central chain of the IMAGE magnetometer network, and cross a morning sector ionospheric shear zone during this passage. In this study we focus on the mesoscale structure of the ionosphere. Ionospheric conductances, true horizontal currents, and field-aligned currents (FAC are calculated from the ground-based measurements of the IMAGE magnetometers and the STARE coherent scatter radar, using the 1-D method of characteristics. An excellent agreement between these results and the FAC observed by Cluster II is reached after averaging the Cluster measurements to mesoscales, as well as between the location of the convection reversal boundary (CRB, as observed by STARE and by the Cluster II EFW instrument. A sheet of downward FAC is observed in the vicinity of the CRB, which is mainly caused by the positive divergence of the electric field there. This FAC sheet is detached by 0.5°–2° of latitude from a more equatorward downward FAC sheet at the poleward flank of the westward electrojet. This latter FAC sheet, as well as the upward FAC at the equatorward flank of the jet, are mainly caused by meridional gradients in the ionospheric conductances, which reach up to 25 S in the electrojet region, but only ~ 5 S poleward of it, with a minimum at the CRB. Particle measurements show that the major part of the downward FAC is carried by upward flowing electrons, and only a small part by downward flowing ions. The open-closed field line boundary is found to be located 3°–4° poleward of the CRB, implying significant errors if the latter is used as a proxy of the former.Key words. Ionosphere

  8. Mesoscale structure of a morning sector ionospheric shear flow region determined by conjugate Cluster II and MIRACLE ground-based observations

    Directory of Open Access Journals (Sweden)

    O. Amm

    Full Text Available We analyse a conjunction event of the Cluster II spacecraft with the MIRACLE ground-based instrument net-work in northern Fennoscandia on 6 February 2001, between 23:00 and 00:00 UT. Shortly after the spacecraft were located at perigee, the Cluster II satellites’ magnetic footpoints move northwards over Scandinavia and Svalbard, almost perfectly aligned with the central chain of the IMAGE magnetometer network, and cross a morning sector ionospheric shear zone during this passage. In this study we focus on the mesoscale structure of the ionosphere. Ionospheric conductances, true horizontal currents, and field-aligned currents (FAC are calculated from the ground-based measurements of the IMAGE magnetometers and the STARE coherent scatter radar, using the 1-D method of characteristics. An excellent agreement between these results and the FAC observed by Cluster II is reached after averaging the Cluster measurements to mesoscales, as well as between the location of the convection reversal boundary (CRB, as observed by STARE and by the Cluster II EFW instrument. A sheet of downward FAC is observed in the vicinity of the CRB, which is mainly caused by the positive divergence of the electric field there. This FAC sheet is detached by 0.5°–2° of latitude from a more equatorward downward FAC sheet at the poleward flank of the westward electrojet. This latter FAC sheet, as well as the upward FAC at the equatorward flank of the jet, are mainly caused by meridional gradients in the ionospheric conductances, which reach up to 25 S in the electrojet region, but only ~ 5 S poleward of it, with a minimum at the CRB. Particle measurements show that the major part of the downward FAC is carried by upward flowing electrons, and only a small part by downward flowing ions. The open-closed field line boundary is found to be located 3°–4° poleward of the CRB, implying significant errors if the latter is used as a proxy of the former.

    Key words

  9. The Hubble Space TelescopeUV Legacy Survey of Galactic Globular Clusters - V. Constraints on formation scenarios

    Science.gov (United States)

    Renzini, A.; D'Antona, F.; Cassisi, S.; King, I. R.; Milone, A. P.; Ventura, P.; Anderson, J.; Bedin, L. R.; Bellini, A.; Brown, T. M.; Piotto, G.; van der Marel, R. P.; Barbuy, B.; Dalessandro, E.; Hidalgo, S.; Marino, A. F.; Ortolani, S.; Salaris, M.; Sarajedini, A.

    2015-12-01

    We build on the evidence provided by our Legacy Survey of Galactic globular clusters (GC) to submit to a crucial test four scenarios currently entertained for the formation of multiple stellar generations in GCs. The observational constraints on multiple generations to be fulfilled are manifold, including GC specificity, ubiquity, variety, predominance, discreteness, supernova avoidance, p-capture processing, helium enrichment and mass budget. We argue that scenarios appealing to supermassive stars, fast rotating massive stars and massive interactive binaries violate in an irreparable fashion two or more among such constraints. Also the scenario appealing to asymptotic giant branch (AGB) stars as producers of the material for next generation stars encounters severe difficulties, specifically concerning the mass budget problem and the detailed chemical composition of second-generation stars. We qualitatively explore ways possibly allowing one to save the AGB scenario, specifically appealing to a possible revision of the cross-section of a critical reaction rate destroying sodium, or alternatively by a more extensive exploration of the vast parameter space controlling the evolutionary behaviour of AGB stellar models. Still, we cannot ensure success for these efforts and totally new scenarios may have to be invented to understand how GCs formed in the early Universe.

  10. Extent of Fecal Contamination of Household Drinking Water in Nepal: Further Analysis of Nepal Multiple Indicator Cluster Survey 2014.

    Science.gov (United States)

    Kandel, Pragya; Kunwar, Ritu; Lamichhane, Prabhat; Karki, Surendra

    2017-02-08

    Water sources classified as "improved" may not necessarily provide safe drinking water for householders. We analyzed data from Nepal Multiple Indicator Cluster Survey 2014 to explore the extent of fecal contamination of household drinking water. Fecal contamination was detected in 81.2% (95% confidence interval [CI]: 77.9-84.2) household drinking water from improved sources and 89.6% (95% CI: 80.4-94.7) in water samples from unimproved sources. In adjusted analysis, there was no difference in odds of fecal contamination of household drinking water between improved and unimproved sources. We observed significantly lower odds of fecal contamination of drinking water in households in higher wealth quintiles, where soap and water were available for handwashing and in households employing water treatment. The extent of contamination of drinking water as observed in this study highlights the huge amount of effort required to ensure the provision of safely managed water in Nepal by 2030 as aimed in sustainable development goals. © The American Society of Tropical Medicine and Hygiene.

  11. Molybdophosphonate clusters as building blocks in the oxomolybdate-organodiphosphonate/cobalt(II)-organoimine system: structural influences of secondary metal coordination preferences and diphosphonate tether lengths.

    Science.gov (United States)

    Armatas, N Gabriel; Allis, Damian G; Prosvirin, Andrew; Carnutu, Gabriel; O'Connor, Charles J; Dunbar, Kim; Zubieta, Jon

    2008-02-04

    Hydrothermal conditions have been used in the preparation of a series of organic-inorganic hybrid materials of the cobalt-molybdophosphonate family. The reactions of MoO(3), cobalt(II) acetate or cobalt(II) acetylacetonate, tetra-2-pyridylpyrazine (tpyprz), and organodiphosphonic acids H(2)O(3)P(CH(2))nPO(3)H(2) (n = 1-5 and 9) of varying tether lengths yielded compounds of the general type {Co(2)(tpyprz)(H(2)O)(m)}4+/MoxOy{O(3)P(CH(2))(n)PO(3)}z. The recurring theme of the structural chemistry is the incorporation of {Mo(5)O(15)(O(3)PR)(2)}(4-) clusters as molecular building blocks observed in the structures of nine phases (compounds 2-9 and 11). The structural consequences of variations in reaction conditions are most apparent in the series with propylene diphosphonate, where four unique structures 4-7 are observed, including two distinct three-dimensional architectures for compounds 5 and 6 whose formulations differ only in the number of water molecules of crystallization. With pentyldiphosphonate, a second phase 10 is obtained which exhibits a unique cluster building block, the hexamolybdate [Mo(6)O(18){O(3)P(CH(2))(5)PO(3)}](4-). In the case of methylenediphosphonic acid, a third structural motif, the trinuclear {(Mo(3)O(8))(O(3)PCH(2)PO(3))}2- subunit, is observed in compound 1. The structural chemistry of compounds 1-11 of this study is quite distinct from that of the {Ni(2)(tpyprz)(H(2)O)(m)}(4+)/Mo(x)O(y){O(3)P(CH(2))(n)PO(3)}z family, as well as that of the copper-based family. The structural diversity of this general class of materials reflects the coordination preferences of the M(II) sites, the extent of aqua ligation to the M(II) sites, the participation of both phosphate oxygen atoms and molybdate oxo-groups in linking to the M(II) sites, and the variability in the number of attachment sites at the molybdophosphonate clusters. Since the charge densities at the peripheral oxygen atoms of the clusters are quite uniform, the attachment of {M(2)(tpyprz

  12. Creation of a 3Mn/1Fe Cluster in the Oxygen-Evolving Complex of Photosystem II and Investigation of its Functional Activity

    Energy Technology Data Exchange (ETDEWEB)

    Seibert, Michael [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Semin, B. K. [Lomonosov Moscow State University; Davletshina, L. N. [Lomonosov Moscow State University; Rubin, A. B. [Lomonosov Moscow State University

    2017-11-11

    Extraction of Mn cations from the oxygen-evolving complex (OEC) of Ca-depleted PSII membranes (PSII[-Ca,4Mn]) by reductants like hydroquinone (H2Q) occurs with lower efficiency at acidic pH (2Mn/reaction center [RC] are extracted at pH 5.7) than at neutral pH (3Mn/RC are extracted at pH 6.5) [Semin et al. Photosynth. Res. 125 (2015) 95]. Fe(II) also extracts Mn cations from PSII(-Ca,4Mn), but only 2Mn/RC at pH 6.5, forming a heteronuclear 2Mn/2Fe cluster [Semin and Seibert, J. Bioenerg. Biomembr. 48 (2016) 227]. Here we investigated the efficiency of Mn extraction by Fe(II) at acidic pH and found that Fe(II) cations can extract only 1Mn/RC from PSII(-Ca,4Mn) membranes at pH 5.7, forming a 3Mn/1Fe cluster.

  13. [High risk groups in health behavior defined by clustering of smoking, alcohol, and exercise habits: National Heath and Nutrition Examination Survey].

    Science.gov (United States)

    Kang, Kiwon; Sung, Joohon; Kim, Chang Yup

    2010-01-01

    We investigated the clustering of selected lifestyle factors (cigarette smoking, heavy alcohol consumption, lack of physical exercise) and identified the population characteristics associated with increasing lifestyle risks. Data on lifestyle risk factors, sociodemographic characteristics, and history of chronic diseases were obtained from 7,694 individuals >/=20 years of age who participated in the 2005 Korea National Health and Nutrition Examination Survey (KNHANES). Clustering of lifestyle risks involved the observed prevalence of multiple risks and those expected from marginal exposure prevalence of the three selected risk factors. Prevalence odds ratio was adopted as a measurement of clustering. Multiple correspondence analysis, Kendall tau correlation, Man-Whitney analysis, and ordinal logistic regression analysis were conducted to identify variables increasing lifestyle risks. In both men and women, increased lifestyle risks were associated with clustering of: (1) cigarette smoking and excessive alcohol consumption, and (2) smoking, excessive alcohol consumption, and lack of physical exercise. Patterns of clustering for physical exercise were different from those for cigarette smoking and alcohol consumption. The increased unhealthy clustering was found among men 20-64 years of age with mild or moderate stress, and among women 35-49 years of age who were never-married, with mild stress, and increased body mass index (>30 kg/m(2)). Addressing a lack of physical exercise considering individual characteristics including gender, age, employment activity, and stress levels should be a focus of health promotion efforts.

  14. Estimated dietary intakes and sources of flavanols in the German population (German National Nutrition Survey II).

    Science.gov (United States)

    Vogiatzoglou, Anna; Heuer, Thorsten; Mulligan, Angela A; Lentjes, Marleen A H; Luben, Robert N; Kuhnle, Gunter G C

    2014-01-01

    Data from intervention studies suggest a beneficial effect of flavanols on vascular health. However, insufficient data on their intake have delayed the assessment of their health benefits. The aim of this study was to estimate intake of flavanols and their main sources among people living in Germany. Data from diet history interviews of the German National Nutrition Survey II for 15,371 people across Germany aged 14-80 years were analyzed. The FLAVIOLA Flavanol Food Composition Database was compiled using the latest US Department of Agriculture and Phenol-Explorer Databases and expanded to include recipes and retention factors. Mean intake of total flavanols, flavan-3-ol monomers, proanthocyanidins (PA), and theaflavins in Germany was 386, 120, 196, and 70 mg/day, respectively. Women had higher intakes of total flavanols (399 mg/day) than men (372 mg/day) in all age groups, with the exception of the elderly. Similar results were observed for monomers (108 mg/day for men, 131 mg/day for women) and PA (190 mg/day; 203 mg/day), although intake of theaflavins was higher in men (74 mg/day; 66 mg/day). There was an age gradient with an increase in total flavanols, monomers, and theaflavins across the age groups. The major contributor of total flavanols in all subjects was pome fruits (27%) followed by black tea (25%). This study demonstrated age- and sex-related variations in the intake and sources of dietary flavanols in Germany. The current analysis will provide a valuable tool in clarifying and confirming the potential health benefits of flavanols.

  15. The Effect of Host Galaxies on Type Ia Supernovae in the SDSS-II Supernova Survey

    Energy Technology Data Exchange (ETDEWEB)

    Lampeitl, Hubert; /Portsmouth U., ICG; Smith, Mathew; /Cape Town U. /Portsmouth U., ICG; Nichol, Robert C.; /Portsmouth U., ICG; Bassett, Bruce; /South African Astron. Observ. /Cape Town U.; Cinabro, David; /Wayne State U.; Dilday, Benjamin; /Rutgers U., Piscataway; Foley, Ryan J.; /Harvard-Smithsonian Ctr. Astrophys.; Frieman, Joshua A.; /Chicago U. /Fermilab; Garnavich, Peter M.; /Notre Dame U.; Goobar, Ariel; /Stockholm U., OKC; Im, Myungshin; /Seoul Natl. U. /Rutgers U., Piscataway

    2010-05-01

    We present an analysis of the host galaxy dependencies of Type Ia Supernovae (SNe Ia) from the full three year sample of the SDSS-II Supernova Survey. We re-discover, to high significance, the strong correlation between host galaxy type and the width of the observed SN light curve, i.e., fainter, quickly declining SNe Ia favor passive host galaxies, while brighter, slowly declining Ia's favor star-forming galaxies. We also find evidence (at between 2 to 3{sigma}) that SNe Ia are {approx_equal} 0.1 magnitudes brighter in passive host galaxies, than in star-forming hosts, after the SN Ia light curves have been standardized using the light curve shape and color variations: This difference in brightness is present in both the SALT2 and MCLS2k2 light curve fitting methodologies. We see evidence for differences in the SN Ia color relationship between passive and star-forming host galaxies, e.g., for the MLCS2k2 technique, we see that SNe Ia in passive hosts favor a dust law of R{sub V} {approx_equal} 1, while SNe Ia in star-forming hosts require R{sub V} {approx} 2. The significance of these trends depends on the range of SN colors considered. We demonstrate that these effects can be parameterized using the stellar mass of the host galaxy (with a confidence of > 4{sigma}) and including this extra parameter provides a better statistical fit to our data. Our results suggest that future cosmological analyses of SN Ia samples should include host galaxy information.

  16. Orientation of the tetranuclear manganese cluster and tyrosine Z in the O(2)-evolving complex of photosystem II: An EPR study of the S(2)Y(Z)(*) state in oriented acetate-inhibited photosystem II membranes.

    Science.gov (United States)

    Lakshmi, K V; Eaton, S S; Eaton, G R; Brudvig, G W

    1999-09-28

    Inhibitory treatment by acetate, followed by illumination and rapid freezing, is known to trap the S(2)Y(Z)(*) state of the O(2)-evolving complex (OEC) in photosystem II (PS II). An EPR spectrum of this state exhibits broad split signals due to the interaction of the tyrosyl radical, Y(Z)(*), with the S = 1/2 S(2) state of the Mn(4) cluster. We present a novel approach to analyze S(2)Y(Z)(*) spectra of one-dimensionally (1-D) oriented acetate-inhibited PS II membranes to determine the magnitude and relative orientation of the S(2)Y(Z)(*) dipolar vector within the membrane. Although there exists a vast body of EPR data on isolated spins in oriented membrane sheets, the present study is the first of its kind on dipolar-coupled electron spin pairs in such systems. We demonstrate the feasibility of the technique and establish a rigorous treatment to account for the disorder present in partially oriented 1-D membrane preparations. We find that (i) the point-dipole distance between Y(Z)(*) and the Mn(4) cluster is 7.9 +/- 0.2 A, (ii) the angle between the interspin vector and the thylakoid membrane normal is 75 degrees, (iii) the g(z)()-axis of the Mn(4) cluster is 70 degrees away from the membrane normal and 35 degrees away from the interspin vector, and (iv) the exchange interaction between the two spins is -275 x 10(-)(4) cm(-)(1), which is antiferromagnetic. Due to the sensitivity of EPR line shapes of oriented spin-coupled pairs to the interspin distance, the present study imposes a tighter constraint on the Y(Z)-Mn(4) point-dipole distance than obtained from randomly oriented samples. The geometric constraints obtained from the 1-D oriented sample are combined with published models of the structure of Mn-depleted PS II to propose a location of the Mn(4) cluster. A structure in which Y(Z) is hydrogen bonded to a manganese-bound hydroxide ligand is consistent with available data and favors maximal orbital overlap between the two redox center that would facilitate

  17. THE SPITZER SPACE TELESCOPE SURVEY OF THE ORION A AND B MOLECULAR CLOUDS. II. THE SPATIAL DISTRIBUTION AND DEMOGRAPHICS OF DUSTY YOUNG STELLAR OBJECTS

    Energy Technology Data Exchange (ETDEWEB)

    Megeath, S. T.; Kryukova, E. [Ritter Astrophsical Research Center, Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606 (United States); Gutermuth, R. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Muzerolle, J. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Hora, J. L.; Myers, P. C.; Fazio, G. G. [Harvard Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Allen, L. E. [National Optical Astronomical Observatory, Tucson, AZ 85719 (United States); Flaherty, K. [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Hartmann, L. [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States); Pipher, J. L. [Department of Physics and Astronomy, University of Rochester, Rochester NY 14627 (United States); Stauffer, J. [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); Young, E. T., E-mail: megeath@physics.utoledo.edu [SOFIA-Universities Space Research Association, NASA Ames Research Center, Moffett Field, CA 94035 (United States)

    2016-01-15

    We analyze the spatial distribution of dusty young stellar objects (YSOs) identified in the Spitzer Survey of the Orion Molecular clouds, augmenting these data with Chandra X-ray observations to correct for incompleteness in dense clustered regions. We also devise a scheme to correct for spatially varying incompleteness when X-ray data are not available. The local surface densities of the YSOs range from 1 pc{sup −2} to over 10,000 pc{sup −2}, with protostars tending to be in higher density regions. This range of densities is similar to other surveyed molecular clouds with clusters, but broader than clouds without clusters. By identifying clusters and groups as continuous regions with surface densities ≥10 pc{sup −2}, we find that 59% of the YSOs are in the largest cluster, the Orion Nebula Cluster (ONC), while 13% of the YSOs are found in a distributed population. A lower fraction of protostars in the distributed population is evidence that it is somewhat older than the groups and clusters. An examination of the structural properties of the clusters and groups shows that the peak surface densities of the clusters increase approximately linearly with the number of members. Furthermore, all clusters with more than 70 members exhibit asymmetric and/or highly elongated structures. The ONC becomes azimuthally symmetric in the inner 0.1 pc, suggesting that the cluster is only ∼2 Myr in age. We find that the star formation efficiency (SFE) of the Orion B cloud is unusually low, and that the SFEs of individual groups and clusters are an order of magnitude higher than those of the clouds. Finally, we discuss the relationship between the young low mass stars in the Orion clouds and the Orion OB 1 association, and we determine upper limits to the fraction of disks that may be affected by UV radiation from OB stars or dynamical interactions in dense, clustered regions.

  18. Field Surveys, IOC Valleys. Volume III, Part II. Cultural Resources Survey, Pine and Wah Wah Valleys, Utah.

    Science.gov (United States)

    1981-08-01

    including horse, camel, mammoth, Ertm E-TR-48-III-II 20 musk ox, and certain species of bison, goat, and bear, which had previously inhabited the marsh and...34 - - -9,$.. 𔄃 Im I I I Si to * Location lype/Contents Affiliation 42B@644 rid e over cr ek - P/J depression, cleared areas, Fr elon (f4-5-18-92) ground

  19. The Gaia-ESO Survey and CSI 2264: Substructures, disks, and sequential star formation in the young open cluster NGC 2264

    Science.gov (United States)

    Venuti, L.; Prisinzano, L.; Sacco, G. G.; Flaccomio, E.; Bonito, R.; Damiani, F.; Micela, G.; Guarcello, M. G.; Randich, S.; Stauffer, J. R.; Cody, A. M.; Jeffries, R. D.; Alencar, S. H. P.; Alfaro, E. J.; Lanzafame, A. C.; Pancino, E.; Bayo, A.; Carraro, G.; Costado, M. T.; Frasca, A.; Jofré, P.; Morbidelli, L.; Sousa, S. G.; Zaggia, S.

    2018-01-01

    Context. Reconstructing the structure and history of young clusters is pivotal to understanding the mechanisms and timescales of early stellar evolution and planet formation. Recent studies suggest that star clusters often exhibit a hierarchical structure, possibly resulting from several star formation episodes occurring sequentially rather than a monolithic cloud collapse. Aims: We aim to explore the structure of the open cluster and star-forming region NGC 2264 ( 3 Myr), which is one of the youngest, richest and most accessible star clusters in the local spiral arm of our Galaxy; we link the spatial distribution of cluster members to other stellar properties such as age and evolutionary stage to probe the star formation history within the region. Methods: We combined spectroscopic data obtained as part of the Gaia-ESO Survey (GES) with multi-wavelength photometric data from the Coordinated Synoptic Investigation of NGC 2264 (CSI 2264) campaign. We examined a sample of 655 cluster members, with masses between 0.2 and 1.8 M⊙ and including both disk-bearing and disk-free young stars. We used Teff estimates from GES and g,r,i photometry from CSI 2264 to derive individual extinction and stellar parameters. Results: We find a significant age spread of 4-5 Myr among cluster members. Disk-bearing objects are statistically associated with younger isochronal ages than disk-free sources. The cluster has a hierarchical structure, with two main blocks along its latitudinal extension. The northern half develops around the O-type binary star S Mon; the southern half, close to the tip of the Cone Nebula, contains the most embedded regions of NGC 2264, populated mainly by objects with disks and ongoing accretion. The median ages of objects at different locations within the cluster, and the spatial distribution of disked and non-disked sources, suggest that star formation began in the north of the cluster, over 5 Myr ago, and was ignited in its southern region a few Myr later

  20. The XXL survey XV: evidence for dry merger driven BCG growth in XXL-100-GC X-ray clusters

    Science.gov (United States)

    Lavoie, S.; Willis, J. P.; Démoclès, J.; Eckert, D.; Gastaldello, F.; Smith, G. P.; Lidman, C.; Adami, C.; Pacaud, F.; Pierre, M.; Clerc, N.; Giles, P.; Lieu, M.; Chiappetti, L.; Altieri, B.; Ardila, F.; Baldry, I.; Bongiorno, A.; Desai, S.; Elyiv, A.; Faccioli, L.; Gardner, B.; Garilli, B.; Groote, M. W.; Guennou, L.; Guzzo, L.; Hopkins, A. M.; Liske, J.; McGee, S.; Melnyk, O.; Owers, M. S.; Poggianti, B.; Ponman, T. J.; Scodeggio, M.; Spitler, L.; Tuffs, R. J.

    2016-11-01

    The growth of brightest cluster galaxies (BCGs) is closely related to the properties of their host cluster. We present evidence for dry mergers as the dominant source of BCG mass growth at z ≲ 1 in the XXL 100 brightest cluster sample. We use the global red sequence, Hα emission and mean star formation history to show that BCGs in the sample possess star formation levels comparable to field ellipticals of similar stellar mass and redshift. XXL 100 brightest clusters are less massive on average than those in other X-ray selected samples such as LoCuSS or HIFLUGCS. Few clusters in the sample display high central gas concentration, rendering inefficient the growth of BCGs via star formation resulting from the accretion of cool gas. Using measures of the relaxation state of their host clusters, we show that BCGs grow as relaxation proceeds. We find that the BCG stellar mass corresponds to a relatively constant fraction 1 per cent of the total cluster mass in relaxed systems. We also show that, following a cluster scale merger event, the BCG stellar mass lags behind the expected value from the Mcluster-MBCG relation but subsequently accretes stellar mass via dry mergers as the BCG and cluster evolve towards a relaxed state.

  1. Orthopedic manifestations in patients with muco­polysaccharidosis type II (Hunter syndrome enrolled in the Hunter Outcome Survey

    Directory of Open Access Journals (Sweden)

    Bianca Link

    2010-07-01

    Full Text Available Mucopolysaccharidosis type II (MPS II or Hunter syndrome is a rare, inherited disorder caused by deficiency of the lysosomal enzyme iduronate-2-sulfatase. As a result of this deficiency, glycosaminoglycans accumulate in lysosomes in many tissues, leading to progressive multisystemic disease. The cardiopulmonary and neurological problems associated with MPS II have received considerable attention. Orthopedic manifestations are common but not as well characterized. This study aimed to characterize the prevalence and severity of orthopedic manifestations of MPS II and to determine the relationship of these signs and symptoms with cardiovascular, pulmonary and central nervous system involvement. Orthopedic manifestations of MPS II were studied using cross-sectional data from the Hunter Outcome Survey (HOS. The HOS is a global, physician-led, multicenter observational database that collects information on the natural history of MPS II and the long-term safety and effectiveness of enzyme replacement therapy. As of January 2009, the HOS contained baseline data on joint range of motion in 124 males with MPS II. In total, 79% of patients had skeletal manifestations (median onset, 3.5 years and 25% had abnormal gait (median onset, 5.4 years. Joint range of motion was restricted for all joints assessed (elbow, shoulder, hip, knee and ankle. Extension was the most severely affected movement: the exception to this was the shoulder. Surgery for orthopedic problems was rare. The presence of orthopedic manifestations was associated with the presence of central nervous system and pulmonary involvement, but not so clearly with cardiovascular involvement. Orthopedic interventions should be considered on an individual-patient basis. Although some orthopedic manifestations associated with MPS II may be managed routinely, a good knowledge of other concurrent organ system involvement is essential. A multidisciplinary approach is required.

  2. Widespread non-adherence to evidence-based maternity care guidelines: a population-based cluster randomised household survey.

    Science.gov (United States)

    Nagpal, J; Sachdeva, A; Sengupta Dhar, R; Bhargava, V L; Bhartia, A

    2015-01-01

    To assess the quality of maternity care in an Indian metropolitan city. Three-stage cluster randomised cross-sectional survey. Sixty selected colonies of Delhi. One thousand eight hundred and one subjects (of 2286 eligible) were enrolled from 118 446 houses. Women who had delivered a live viable birth in the past 6 months were selected for the study. In stage 1, 20 wards (of 150) were selected using a probability-proportionate-to-size systematic method. In stage 2, one colony from each income stratum (high, middle and low) was selected from each ward by simple random sampling. In stage 3, a house-to-house survey was conducted to recruit 30 women for administering a peer-reviewed and pilot-trialled questionnaire. Caesarean section rate, induction rate and episiotomy rate. National health targets such as iron supplementation advice (>96%), tetanus vaccination (>81%), and ≥3 antenatal visits (>90%) were largely achieved across health care facilities but not in home deliveries. Interventions were lower in public than private hospitals: caesarean section [23.7% (20.2-27.7) versus 53.8% (49.3-58.3)], induction [20.6% (17.5-24.25) versus 30.8% (26.8-33.2)] and episiotomy [57.8% (52.3-63.1) versus 79.4% (71.0-85.9)]. Private hospitals achieved better labour support rates [1.1% (0.5-2.2) versus 14.6% (8.5-24.1)] and pain relief [0.9% (0.4-2.0) versus 9.9 (6.5-14.8)]. Pubic hair shaving [16.2% (11.5-22.5) versus 36.4% (29.9-43.4)], enema [20.2% (15.5-26.0) versus 57.3% (49.5-64.8)], and IV fluids during labour [44.0% (36.2-52.2) versus 38.7% (29.3-49.1)] were widely prevalent in public and private hospitals. Present practices fall short of evidence-based guidelines, with relative overuse of interventions in private hospitals and deficiency of patient-centred practices such as labour support in public hospitals. © 2014 Royal College of Obstetricians and Gynaecologists.

  3. THE HUBBLE SPACE TELESCOPE UV LEGACY SURVEY OF GALACTIC GLOBULAR CLUSTERS. III. A QUINTUPLE STELLAR POPULATION IN NGC 2808

    Energy Technology Data Exchange (ETDEWEB)

    Milone, A. P.; Marino, A. F.; Jerjen, H. [Research School of Astronomy and Astrophysics, The Australian National University, Cotter Road, Weston, ACT, 2611 (Australia); Piotto, G. [Istituto Nazionale di Astrofisica—Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, Padova, IT-35122 (Italy); Renzini, A.; Bedin, L. R. [Dipartimento di Fisica e Astronomia “Galileo Galilei,” Univ. di Padova, Vicolo dell’Osservatorio 3, Padova, IT-35122 (Italy); Anderson, J.; Bellini, A. [Space Telescope Science Institute, 3800 San Martin Drive, Baltimore, MD 21218 (United States); Cassisi, S.; Pietrinferni, A. [Istituto Nazionale di Astrofisica—Osservatorio Astronomico di Teramo, Via Mentore Maggini s.n.c., I-64100 Teramo (Italy); D’Antona, F.; Ventura, P. [Istituto Nazionale di Astrofisica—Osservatorio Astronomico di Roma, Via Frascati 33, I-00040 Monteporzio Catone, Roma (Italy)

    2015-07-20

    In this study we present the first results from multi-wavelength Hubble Space Telescope (HST) observations of the Galactic globular cluster (GC) NGC 2808 as an extension of the Hubble Space Telescope UV Legacy Survey of Galactic GCs (GO-13297 and previous proprietary and HST archive data). Our analysis allowed us to disclose a multiple-stellar-population phenomenon in NGC 2808 even more complex than previously thought. We have separated at least five different populations along the main sequence and the red giant branch (RGB), which we name A, B, C, D, and E (though an even finer subdivision may be suggested by the data). We identified the RGB bump in four out of the five RGBs. To explore the origin of this complex color–magnitude diagram, we have combined our multi-wavelength HST photometry with synthetic spectra, generated by assuming different chemical compositions. The comparison of observed colors with synthetic spectra suggests that the five stellar populations have different contents of light elements and helium. Specifically, if we assume that NGC 2808 is homogeneous in [Fe/H] (as suggested by spectroscopy for Populations B, C, D, E, but lacking for Population A) and that population A has a primordial helium abundance, we find that populations B, C, D, E are enhanced in helium by ΔY ∼ 0.03, 0.03, 0.08, 0.13, respectively. We obtain similar results by comparing the magnitude of the RGB bumps with models. Planned spectroscopic observations will test whether Population A also has the same metallicity, or whether its photometric differences with Population B can be ascribed to small [Fe/H] and [O/H] differences rather than to helium.

  4. Early sexual initiation and multiple sexual partners among Vietnamese women: analysis from the Multiple Indicator Cluster Survey, 2011

    Directory of Open Access Journals (Sweden)

    Dinh Thai Son

    2016-02-01

    Full Text Available Introduction: Under current HIV transmission mechanisms operating in Vietnam, women are seen as victims of their male partners. Having multiple sexual partners is one of the well-known risk factors for HIV infection. However, little is known about women's risky sexual behaviour and their vulnerability to HIV in Vietnam. This study aims to explore association between early sexual initiation and the number of lifetime sexual partners in Vietnamese women. Although the Vietnamese culture is socially conservative in this area, identifying women's risky sexual behaviour is important for the protection of women at risk of HIV and other sexually transmitted diseases. Design: A total of 8,791 women, who reported having had sexual intercourse, were included in this analysis of data from the 2011 Multiple Indicator Cluster Survey in Vietnam. Data were collected using two-stage strata sampling, first at the national level and second across six geographical regions (n=8,791. Multivariable logistic regressions describe association between early initiation of a sexual activity and lifetime multiple sexual partners. Results: Early sexual intercourse was significantly associated with having lifetime multiple sexual partners. Women who were aged 19 or younger at first sexual intercourse were over five times more likely to have multiple sexual partners, compared with women whose first sexual intercourse was after marriage; aged 10–14 years (OR=5.9; 95% CI=1.9–18.8 at first intercourse; and aged 15–19 years (OR=5.4; 95% CI=4.0–7.2 at first intercourse. There was significant association with having multiple sexual partners for women of lower household wealth and urban residence, but the association with educational attainment was not strong. Conclusions: The study results call for health and education policies to encourage the postponement of early sexual activity in young Vietnamese women as protection against risky sexual behaviour later in life.

  5. Trends in socioeconomic inequalities in child malnutrition in Vietnam: findings from the Multiple Indicator Cluster Surveys, 2000–2011

    Directory of Open Access Journals (Sweden)

    Vu Duy Kien

    2016-02-01

    Full Text Available Background: Child malnutrition is not only a major contributor to child mortality and morbidity, but it can also determine socioeconomic status in adult life. The rate of under-five child malnutrition in Vietnam has significantly decreased, but associated inequality issues still need attention. Objective: This study aims to explore trends, contributing factors, and changes in inequalities for under-five child malnutrition in Vietnam between 2000 and 2011. Design: Data were drawn from the Viet Nam Multiple Indicator Cluster Survey for the years 2000 and 2011. The dependent variables used for the study were stunting, underweight, and wasting of under-five children. The concentration index was calculated to see the magnitude of child malnutrition, and the inequality was decomposed to understand the contributions of determinants to child malnutrition. The total differential decomposition was used to identify and explore factors contributing to changes in child malnutrition inequalities. Results: Inequality in child malnutrition increased between 2000 and 2011, even though the overall rate declined. Most of the inequality in malnutrition was due to ethnicity and socioeconomic status. The total differential decomposition showed that the biggest and second biggest contributors to the changes in underweight inequalities were age and socioeconomic status, respectively. Socioeconomic status was the largest contributor to inequalities in stunting. Conclusions: Although the overall level of child malnutrition was improved in Vietnam, there were significant differences in under-five child malnutrition that favored those who were more advantaged in socioeconomic terms. The impact of socioeconomic inequalities in child malnutrition has increased over time. Multifaceted approaches, connecting several relevant ministries and sectors, may be necessary to reduce inequalities in childhood malnutrition.

  6. Effect of child marriage on girls' school dropout in Nepal: Analysis of data from the Multiple Indicator Cluster Survey 2014

    Science.gov (United States)

    Sekine, Kazutaka; Hodgkin, Marian Ellen

    2017-01-01

    School dropout and child marriage are interrelated outcomes that have an enormous impact on adolescent girls. However, the literature reveals gaps in the empirical evidence on the link between child marriage and the dropout of girls from school. This study identifies the ‘tipping point’ school grades in Nepal when the risk of dropout due to marriage is highest, measures the effect of child marriage on girls’ school dropout rates, and assesses associated risk factors. Weighted percentages were calculated to examine the grades at highest risk and the distribution of reasons for discontinuing school. Using the Nepal Multiple Indicator Cluster Survey (MICS) 2014 data, we estimated the effect of marriage on school attendance and dropout among girls aged 15–17 by constructing logistic regression models. A multivariate logistic regression model was used to assess risk factors of school dropout due to child marriage. It was found that early marriage is the most common reason given for leaving school. Overall, the risk of school dropout due to marriage heightens after girls complete the fifth or sixth grade. The risk of girls’ dropping out peaks in the seventh and eighth grades and remains noteworthy in the ninth and tenth grades. Married girls in Nepal are 10 times more likely to drop out than their unmarried peers. Little or no education of the household head, belonging to the Kirat religion, and membership of a traditionally disadvantaged social class each elevate the risk of school dropout due to early marriage. The findings underscore the need to delay girl’s marriage so as to reduce girls’ school dropout in Nepal. School-based programmes aimed at preventing child marriage should target girls from the fifth grade because they are at increased risk of dropping out, as well as prioritizing girls from disadvantaged groups. PMID:28727793

  7. Effect of child marriage on girls' school dropout in Nepal: Analysis of data from the Multiple Indicator Cluster Survey 2014.

    Directory of Open Access Journals (Sweden)

    Kazutaka Sekine

    Full Text Available School dropout and child marriage are interrelated outcomes that have an enormous impact on adolescent girls. However, the literature reveals gaps in the empirical evidence on the link between child marriage and the dropout of girls from school. This study identifies the 'tipping point' school grades in Nepal when the risk of dropout due to marriage is highest, measures the effect of child marriage on girls' school dropout rates, and assesses associated risk factors. Weighted percentages were calculated to examine the grades at highest risk and the distribution of reasons for discontinuing school. Using the Nepal Multiple Indicator Cluster Survey (MICS 2014 data, we estimated the effect of marriage on school attendance and dropout among girls aged 15-17 by constructing logistic regression models. A multivariate logistic regression model was used to assess risk factors of school dropout due to child marriage. It was found that early marriage is the most common reason given for leaving school. Overall, the risk of school dropout due to marriage heightens after girls complete the fifth or sixth grade. The risk of girls' dropping out peaks in the seventh and eighth grades and remains noteworthy in the ninth and tenth grades. Married girls in Nepal are 10 times more likely to drop out than their unmarried peers. Little or no education of the household head, belonging to the Kirat religion, and membership of a traditionally disadvantaged social class each elevate the risk of school dropout due to early marriage. The findings underscore the need to delay girl's marriage so as to reduce girls' school dropout in Nepal. School-based programmes aimed at preventing child marriage should target girls from the fifth grade because they are at increased risk of dropping out, as well as prioritizing girls from disadvantaged groups.

  8. Effect of child marriage on girls' school dropout in Nepal: Analysis of data from the Multiple Indicator Cluster Survey 2014.

    Science.gov (United States)

    Sekine, Kazutaka; Hodgkin, Marian Ellen

    2017-01-01

    School dropout and child marriage are interrelated outcomes that have an enormous impact on adolescent girls. However, the literature reveals gaps in the empirical evidence on the link between child marriage and the dropout of girls from school. This study identifies the 'tipping point' school grades in Nepal when the risk of dropout due to marriage is highest, measures the effect of child marriage on girls' school dropout rates, and assesses associated risk factors. Weighted percentages were calculated to examine the grades at highest risk and the distribution of reasons for discontinuing school. Using the Nepal Multiple Indicator Cluster Survey (MICS) 2014 data, we estimated the effect of marriage on school attendance and dropout among girls aged 15-17 by constructing logistic regression models. A multivariate logistic regression model was used to assess risk factors of school dropout due to child marriage. It was found that early marriage is the most common reason given for leaving school. Overall, the risk of school dropout due to marriage heightens after girls complete the fifth or sixth grade. The risk of girls' dropping out peaks in the seventh and eighth grades and remains noteworthy in the ninth and tenth grades. Married girls in Nepal are 10 times more likely to drop out than their unmarried peers. Little or no education of the household head, belonging to the Kirat religion, and membership of a traditionally disadvantaged social class each elevate the risk of school dropout due to early marriage. The findings underscore the need to delay girl's marriage so as to reduce girls' school dropout in Nepal. School-based programmes aimed at preventing child marriage should target girls from the fifth grade because they are at increased risk of dropping out, as well as prioritizing girls from disadvantaged groups.

  9. Backlog and burden of fractures in Sierra Leone and Nepal: Results from nationwide cluster randomized, population-based surveys.

    Science.gov (United States)

    Stewart, Barclay T; Kushner, Adam L; Kamara, Thaim B; Shrestha, Sunil; Gupta, Shailvi; Groen, Reinou S; Nwomeh, Ben; Gosselin, Richard A; Spiegel, David

    2016-09-01

    The burden of injury is increasing worldwide; planning for its impact on population health and health systems is urgently needed, particularly in low- and middle-income countries (LMICs). This study aimed to model the burden of fractures and project costs to eliminate avertable fracture-related disability-adjusted life-years (i.e., a measure of overall disease burden, expressed as the number of years lost due to ill-health, disability or premature death; DALYs) in Sierra Leone and Nepal. Data from nationwide, cluster-randomized, community-based surveys of surgical need in Sierra Leone and Nepal were used to model the incidence and prevalence of fractures stratified by met and unmet needs. DALYs incurred from treated and untreated fractures were estimated. Additionally, the investment necessary to eliminate avertable incident fracture DALYs was modeled through 2025 using published cost per DALY averted estimates. The incidence of treated and untreated fractures in Sierra Leone was 570 and 1004 fractures per 100,000 persons, respectively. There could be more than 2 million avertable fracture DALYs by 2025 in Sierra Leone and 2.5 million in Nepal requiring an estimated US$ 4,049,932 (range US$ 2,011,500-6,088,364) and US$ 4,962,402 (range US$ 2,464,701-7,460,103) to address this excess burden, respectively. This study identified a significant burden of untreated fractures in both countries, and an opportunity to avert more than 4.5 million DALYs in 10 years in a cost-effective manner. Prioritizing funding mechanisms for orthopaedic care and implants should be considered given the large burden of untreated fractures found in both countries and the long-term savings and functional benefit from properly treated fractures. Copyright © 2016. Published by Elsevier Ltd.

  10. Trends in socioeconomic inequalities in child malnutrition in Vietnam: findings from the Multiple Indicator Cluster Surveys, 2000–2011

    Science.gov (United States)

    Kien, Vu Duy; Lee, Hwa-Young; Nam, You-Seon; Oh, Juhwan; Giang, Kim Bao; Van Minh, Hoang

    2016-01-01

    Background Child malnutrition is not only a major contributor to child mortality and morbidity, but it can also determine socioeconomic status in adult life. The rate of under-five child malnutrition in Vietnam has significantly decreased, but associated inequality issues still need attention. Objective This study aims to explore trends, contributing factors, and changes in inequalities for under-five child malnutrition in Vietnam between 2000 and 2011. Design Data were drawn from the Viet Nam Multiple Indicator Cluster Survey for the years 2000 and 2011. The dependent variables used for the study were stunting, underweight, and wasting of under-five children. The concentration index was calculated to see the magnitude of child malnutrition, and the inequality was decomposed to understand the contributions of determinants to child malnutrition. The total differential decomposition was used to identify and explore factors contributing to changes in child malnutrition inequalities. Results Inequality in child malnutrition increased between 2000 and 2011, even though the overall rate declined. Most of the inequality in malnutrition was due to ethnicity and socioeconomic status. The total differential decomposition showed that the biggest and second biggest contributors to the changes in underweight inequalities were age and socioeconomic status, respectively. Socioeconomic status was the largest contributor to inequalities in stunting. Conclusions Although the overall level of child malnutrition was improved in Vietnam, there were significant differences in under-five child malnutrition that favored those who were more advantaged in socioeconomic terms. The impact of socioeconomic inequalities in child malnutrition has increased over time. Multifaceted approaches, connecting several relevant ministries and sectors, may be necessary to reduce inequalities in childhood malnutrition. PMID:26950558

  11. Trends in socioeconomic inequalities in child malnutrition in Vietnam: findings from the Multiple Indicator Cluster Surveys, 2000-2011.

    Science.gov (United States)

    Kien, Vu Duy; Lee, Hwa-Young; Nam, You-Seon; Oh, Juhwan; Giang, Kim Bao; Van Minh, Hoang

    2016-01-01

    Child malnutrition is not only a major contributor to child mortality and morbidity, but it can also determine socioeconomic status in adult life. The rate of under-five child malnutrition in Vietnam has significantly decreased, but associated inequality issues still need attention. This study aims to explore trends, contributing factors, and changes in inequalities for under-five child malnutrition in Vietnam between 2000 and 2011. Data were drawn from the Viet Nam Multiple Indicator Cluster Survey for the years 2000 and 2011. The dependent variables used for the study were stunting, underweight, and wasting of under-five children. The concentration index was calculated to see the magnitude of child malnutrition, and the inequality was decomposed to understand the contributions of determinants to child malnutrition. The total differential decomposition was used to identify and explore factors contributing to changes in child malnutrition inequalities. Inequality in child malnutrition increased between 2000 and 2011, even though the overall rate declined. Most of the inequality in malnutrition was due to ethnicity and socioeconomic status. The total differential decomposition showed that the biggest and second biggest contributors to the changes in underweight inequalities were age and socioeconomic status, respectively. Socioeconomic status was the largest contributor to inequalities in stunting. Although the overall level of child malnutrition was improved in Vietnam, there were significant differences in under-five child malnutrition that favored those who were more advantaged in socioeconomic terms. The impact of socioeconomic inequalities in child malnutrition has increased over time. Multifaceted approaches, connecting several relevant ministries and sectors, may be necessary to reduce inequalities in childhood malnutrition.

  12. Comparison of the manganese cluster in oxygen-evolving photosystem II with distorted cubane manganese compounds through X-ray absorption spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Cinco, R.M.; Rompel, A.; Visser, H.; Aromi, G.; Christou, G.; Sauer, K.; Klein, M.P.; Yachandra, V.K.

    1999-12-27

    X-ray absorption spectroscopy has been employed to assess the degree of similarity between the oxygen-evolving complex (OEC) in photosystem II (PS II) and a family of synthetic manganese complexes containing the distorted cubane [Mn{sub 4}O{sub 3}X] core (C = benzoate, acetate, methoxide, hydroxide, azide, fluoride, chloride, or bromide). These [Mn{sub 4}({mu}{sub 3}-O){sub 3}({mu}{sub 3}-X)] cubanes possess C{sub 3}{nu} symmetry except for the X = benzoate species, which is slightly more distorted with only C{sub s} symmetry. In addition, Mn{sub 4}O{sub 3}Cl complexes containing three or six terminal Cl ligands at three of the Mn were included in this study. The Mn K-edge X-ray absorption near edge structure (XANES) from the oxygen-ligated complexes begin to resemble general features of the PS II (S{sub 1} state) spectrum, although the second derivatives are distinct from those in PS II. The extended X-ray absorption fine structure (EXAFS) of these Mn compounds also displays superficial resemblance to that of PS II, but major differences emerge on closer examination of the phases and amplitudes. The most obvious distinction is the smaller magnitude of the Fourier transform (FT) of the PS II EXAFS compared to the FTs from the distorted cubanes. Curve fitting of the Mn EXAFS spectra verifies the known core structures of the Mn cubanes, and shows that the number of the crucial 2.7 and 3.3 {angstrom} Mn-Mn distance differs from that observed in the OEC. The EXAFS method detects small changes in the core structures as X is varied in this series, and serves to exclude the distorted cubane of C{sub 3{nu}} symmetry as a topological model for the Mn catalytic cluster of the OEC. Instead, the method shows that even more distortion of the cubane framework, altering the ratio of the Mn-Mn distances, is required to resemble the Mn cluster in PS II.

  13. The Gaia-ESO Survey: the present-day radial metallicity distribution of the Galactic disc probed by pre-main-sequence clusters

    Science.gov (United States)

    Spina, L.; Randich, S.; Magrini, L.; Jeffries, R. D.; Friel, E. D.; Sacco, G. G.; Pancino, E.; Bonito, R.; Bravi, L.; Franciosini, E.; Klutsch, A.; Montes, D.; Gilmore, G.; Vallenari, A.; Bensby, T.; Bragaglia, A.; Flaccomio, E.; Koposov, S. E.; Korn, A. J.; Lanzafame, A. C.; Smiljanic, R.; Bayo, A.; Carraro, G.; Casey, A. R.; Costado, M. T.; Damiani, F.; Donati, P.; Frasca, A.; Hourihane, A.; Jofré, P.; Lewis, J.; Lind, K.; Monaco, L.; Morbidelli, L.; Prisinzano, L.; Sousa, S. G.; Worley, C. C.; Zaggia, S.

    2017-05-01

    Context. The radial metallicity distribution in the Galactic thin disc represents a crucial constraint for modelling disc formation and evolution. Open star clusters allow us to derive both the radial metallicity distribution and its evolution over time. Aims: In this paper we perform the first investigation of the present-day radial metallicity distribution based on [Fe/H] determinations in late type members of pre-main-sequence clusters. Because of their youth, these clusters are therefore essential for tracing the current interstellar medium metallicity. Methods: We used the products of the Gaia-ESO Survey analysis of 12 young regions (age < 100 Myr), covering Galactocentric distances from 6.67 to 8.70 kpc. For the first time, we derived the metal content of star forming regions farther than 500 pc from the Sun. Median metallicities were determined through samples of reliable cluster members. For ten clusters the membership analysis is discussed in the present paper, while for other two clusters (i.e. Chamaeleon I and Gamma Velorum) we adopted the members identified in our previous works. Results: All the pre-main-sequence clusters considered in this paper have close-to-solar or slightly sub-solar metallicities. The radial metallicity distribution traced by these clusters is almost flat, with the innermost star forming regions having [Fe/H] values that are 0.10-0.15 dex lower than the majority of the older clusters located at similar Galactocentric radii. Conclusions: This homogeneous study of the present-day radial metallicity distribution in the Galactic thin disc favours models that predict a flattening of the radial gradient over time. On the other hand, the decrease of the average [Fe/H] at young ages is not easily explained by the models. Our results reveal a complex interplay of several processes (e.g. star formation activity, initial mass function, supernova yields, gas flows) that controlled the recent evolution of the Milky Way. Based on observations

  14. Angiotensin II type 2 receptor is critical for the development of human fetal pancreatic progenitor cells into islet-like cell clusters and their potential for transplantation.

    Science.gov (United States)

    Leung, Kwan Keung; Liang, Juan; Ma, Man Ting; Leung, Po Sing

    2012-03-01

    Local renin-angiotensin systems (RASs) regulate the differentiation of tissue progenitors. However, it is not known whether such systems can regulate the development of pancreatic progenitor cells (PPCs). To address this issue, we characterized the expression profile of major RAS components in human fetal PPC preparations and examined their effects on the differentiation of PPCs into functional islet-like cell clusters (ICCs). We found that expression of RAS components was highly regulated throughout PPC differentiation and that locally generated angiotensin II (Ang II) maintained PPC growth and differentiation via Ang II type 1 and type 2 (AT(1) and AT(2)) receptors. In addition, we observed colocalization of AT(2) receptors with critical β-cell phenotype markers in PPCs/ICCs, as well as AT(2) receptor upregulation during differentiation, suggesting that these receptors may regulate β-cell development. In fact, we found that AT(2) , but not AT(1) , receptor was a key mediator of Ang II-induced upregulation of transcription factors important in β-cell development. Furthermore, lentivirus-mediated knockdown of AT(2) receptor suppressed the expression of these transcription factors in ICCs. Transplantation of AT(2) receptor-depleted ICCs into immune-privileged diabetic mice failed to ameliorate hyperglycemia, implying that AT(2) receptors are indispensable during ICC maturation in vivo. These data strongly indicate that a local RAS is involved in governing the functional maturation of pancreatic progenitors toward the endocrine lineage. Copyright © 2011 AlphaMed Press.

  15. Star formation in the first galaxies - II. Clustered star formation and the influence of metal line cooling

    Science.gov (United States)

    Safranek-Shrader, Chalence; Milosavljević, Miloš; Bromm, Volker

    2014-02-01

    We present results from three cosmological simulations, only differing in gas metallicity, that focus on the impact of metal fine-structure line cooling on stellar cluster formation in a high-redshift atomic cooling halo. Sink particles allow the process of gas hydrodynamics and accretion on to cluster stars to be followed for ˜4 Myr corresponding to multiple local free-fall times. At metallicities at least 10-3 Z⊙, gas is able to reach the cosmic microwave background temperature floor and fragment pervasively resulting in a stellar cluster of size ˜1 pc and total mass ˜1000 M⊙. The masses of individual sink particles vary, but are typically ˜100 M⊙, consistent with the Jeans mass at TCMB, though some solar mass fragments are also produced. Below 10-4 Z⊙, fragmentation is strongly suppressed on scales greater than 0.01 pc and total stellar mass is lower by a factor of ˜3 than in the higher metallicity simulations. The sink particle accretion rates, and thus their masses, are determined by the mass of the gravitationally unstable gas cloud and prolonged gas accretion over many Myr, exhibiting features of both monolithic collapse and competitive accretion. Even considering possible dust-induced fragmentation that may occur at higher densities, the formation of a bona fide stellar cluster seems to require metal line cooling and metallicities of at least ˜10-3 Z⊙.

  16. The Atacama Cosmology Telescope: Sunyaev-Zel'dovich-Selected Galaxy Clusters AT 148 GHz in the 2008 Survey

    Science.gov (United States)

    Marriage, Tobias A.; Acquaviva, Viviana; Ade, Peter A. R.; Aguirre, Paula; Amiri, Mandana; Appel, John William; Barrientos, L. Felipe; Battistelli, Elia S.; Bond, J. Richard; Brown, Ben; hide

    2011-01-01

    We report on 23 clusters detected blindly as Sunyaev-Zel'dovich (SZ) decrements in a 148 GHz, 455 deg (exp 2) map of the southern sky made with data from the Atacama Cosmology Telescope 2008 observing season. All SZ detections announced in this work have confirmed optical counterparts. Ten of the clusters are new discoveries. One newly discovered cluster, ACT-CL 10102-4915, with a redshift of 0.75 (photometric), has an SZ decrement comparable to the most massive systems at lower redshifts. Simulations of the cluster recovery method reproduce the sample purity measured by optical follow-up. In particular, for clusters detected with a signal-to-noise ratio greater than six, simulations are consistent with optical follow-up that demonstrated this subsample is 100% pure, The simulations further imply that the total sample is 80% complete for clusters with mass in excess of 6 x 10(exp 14) solar masses referenced to the cluster volume characterized by 500 times the critical density. The Compton gamma-X-ray luminosity mass comparison for the 11 best-detected clusters visually agrees with both self-similar and non-adiabatic, simulation-derived scaling laws,

  17. The VLT-FLAMES Tarantula Survey. VI. Evidence for rotation of the young massive cluster R136

    NARCIS (Netherlands)

    Hénault-Brunet, V.; Gieles, M.; Evans, C.J.; Sana, H.; Bastian, N.; Maíz Apellániz, J.; Taylor, W.D.; Markova, N.; Bressert, E.; de Koter, A.; van Loon, J.T.

    2012-01-01

    Although it has important ramifications for both the formation of star clusters and their subsequent dynamical evolution, rotation remains a largely unexplored characteristic of young star clusters (few Myr). Using multi-epoch spectroscopic data of the inner regions of 30 Doradus in the Large

  18. Weak-Lensing Mass Calibration of the Atacama Cosmology Telescope Equatorial Sunyaev-Zeldovich Cluster Sample with the Canada-France-Hawaii Telescope Stripe 82 Survey

    Science.gov (United States)

    Battaglia, N.; Leauthaud, A.; Miyatake, H.; Hasseleld, M.; Gralla, M. B.; Allison, R.; Bond, J. R.; Calabrese, E.; Crichton, D.; Devlin, M. J.; hide

    2016-01-01

    Mass calibration uncertainty is the largest systematic effect for using clustersof galaxies to constrain cosmological parameters. We present weak lensing mass measurements from the Canada-France-Hawaii Telescope Stripe 82 Survey for galaxy clusters selected through their high signal-to-noise thermal Sunyaev-Zeldovich (tSZ) signal measured with the Atacama Cosmology Telescope (ACT). For a sample of 9 ACT clusters with a tSZ signal-to-noise greater than five, the average weak lensing mass is (4.8 plus or minus 0.8) times 10 (sup 14) solar mass, consistent with the tSZ mass estimate of (4.7 plus or minus 1.0) times 10 (sup 14) solar mass, which assumes a universal pressure profile for the cluster gas. Our results are consistent with previous weak-lensing measurements of tSZ-detected clusters from the Planck satellite. When comparing our results, we estimate the Eddington bias correction for the sample intersection of Planck and weak-lensing clusters which was previously excluded.

  19. GALAXY CLUSTERS DISCOVERED VIA THE SUNYAEV-ZEL'DOVICH EFFECT IN THE 2500-SQUARE-DEGREE SPT-SZ SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Bleem, L. E.; Stalder, B.; de Haan, T.; Aird, K. A.; Allen, S. W.; Applegate, D. E.; Ashby, M. L. N.; Bautz, M.; Bayliss, M.; Benson, B. A.; Bocquet, S.; Brodwin, M.; Carlstrom, J. E.; Chang, C. L.; Chiu, I.; Cho, H. M.; Clocchiatti, A.; Crawford, T. M.; Crites, A. T.; Desai, S.; Dietrich, J. P.; Dobbs, M. A.; Foley, R. J.; Forman, W. R.; George, E. M.; Gladders, M. D.; Gonzalez, A. H.; Halverson, N. W.; Hennig, C.; Hoekstra, H.; Holder, G. P.; Holzapfel, W. L.; Hrubes, J. D.; Jones, C.; Keisler, R.; Knox, L.; Lee, A. T.; Leitch, E. M.; Liu, J.; Lueker, M.; Luong-Van, D.; Mantz, A.; Marrone, D. P.; McDonald, M.; McMahon, J. J.; Meyer, S. S.; Mocanu, L.; Mohr, J. J.; Murray, S. S.; Padin, S.; Pryke, C.; Reichardt, C. L.; Rest, A.; Ruel, J.; Ruhl, J. E.; Saliwanchik, B. R.; Saro, A.; Sayre, J. T.; Schaffer, K. K.; Schrabback, T.; Shirokoff, E.; Song, J.; Spieler, H. G.; Stanford, S. A.; Staniszewski, Z.; Stark, A. A.; Story, K. T.; Stubbs, C. W.; Vanderlinde, K.; Vieira, J. D.; Vikhlinin, A.; Williamson, R.; Zahn, O.; Zenteno, A.

    2015-01-29

    We present a catalog of galaxy clusters selected via their Sunyaev-Zel'dovich (SZ) effect signature from 2500 deg(2) of South Pole Telescope (SPT) data. This work represents the complete sample of clusters detected at high significance in the 2500 deg(2) SPT-SZ survey, which was completed in 2011. A total of 677 (409) cluster candidates are identified above a signal-to-noise threshold of xi = 4.5 (5.0). Ground-and space-based optical and near-infrared (NIR) imaging confirms overdensities of similarly colored galaxies in the direction of 516 (or 76%) of the xi > 4.5 candidates and 387 (or 95%) of the xi > 5 candidates; the measured purity is consistent with expectations from simulations. Of these confirmed clusters, 415 were first identified in SPT data, including 251 new discoveries reported in this work. We estimate photometric redshifts for all candidates with identified optical and/or NIR counterparts; we additionally report redshifts derived from spectroscopic observations for 141 of these systems. The mass threshold of the catalog is roughly independent of redshift above z similar to 0.25 leading to a sample of massive clusters that extends to high redshift. The median mass of the sample is M-500c(rho(crit)) similar to 3.5 x 10(14) M-circle dot h(70)(-1) 70, the median redshift is z(med) = 0.55, and the highest-redshift systems are at z > 1.4. The combination of large redshift extent, clean selection, and high typical mass makes this cluster sample of particular interest for cosmological analyses and studies of cluster formation and evolution.

  20. GALAXY CLUSTERS DISCOVERED VIA THE SUNYAEV-ZEL'DOVICH EFFECT IN THE 2500-SQUARE-DEGREE SPT-SZ SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Bleem, L. E.; Stalder, B.; de Haan, T.; Aird, K. A.; Allen, S. W.; Applegate, D. E.; Ashby, M. L. N.; Bautz, M.; Bayliss, M.; Benson, B. A.; Bocquet, S.; Brodwin, M.; Carlstrom, J. E.; Chang, C. L.; Chiu, I.; Cho, H. M.; Clocchiatti, A.; Crawford, T. M.; Crites, A. T.; Desai, S.; Dietrich, J. P.; Dobbs, M. A.; Foley, R. J.; Forman, W. R.; George, E. M.; Gladders, M. D.; Gonzalez, A. H.; Halverson, N. W.; Hennig, C.; Hoekstra, H.; Holder, G. P.; Holzapfel, W. L.; Hrubes, J. D.; Jones, C.; Keisler, R.; Knox, L.; Lee, A. T.; Leitch, E. M.; Liu, J.; Lueker, M.; Luong-Van, D.; Mantz, A.; Marrone, D. P.; McDonald, M.; McMahon, J. J.; Meyer, S. S.; Mocanu, L.; Mohr, J. J.; Murray, S. S.; Padin, S.; Pryke, C.; Reichardt, C. L.; Rest, A.; Ruel, J.; Ruhl, J. E.; Saliwanchik, B. R.; Saro, A.; Sayre, J. T.; Schaffer, K. K.; Schrabback, T.; Shirokoff, E.; Song, J.; Spieler, H. G.; Stanford, S. A.; Staniszewski, Z.; Stark, A. A.; Story, K. T.; Stubbs, C. W.; Vanderlinde, K.; Vieira, J. D.; Vikhlinin, A.; Williamson, R.; Zahn, O.; Zenteno, A.

    2015-01-29

    We present a catalog of galaxy clusters selected via their Sunyaev-Zel'dovich (SZ) effect signature from 2500 deg(2) of South Pole Telescope (SPT) data. This work represents the complete sample of clusters detected at high significance in the 2500 deg(2) SPT-SZ survey, which was completed in 2011. A total of 677 (409) cluster candidates are identified above a signal-to-noise threshold of ξ = 4.5 (5.0). Ground- and space-based optical and near-infrared (NIR) imaging confirms overdensities of similarly colored galaxies in the direction of 516 (or 76%) of the ξ > 4.5 candidates and 387 (or 95%) of the ξ > 5 candidates, the measured purity is consistent with expectations from simulations. Of these confirmed clusters, 415 were first identified in SPT data, including 251 new discoveries reported in this work. We estimate photometric redshifts for all candidates with identified optical and/or NIR counterparts, we additionally report redshifts derived from spectroscopic observations for 141 of these systems. The mass threshold of the catalog is roughly independent of redshift above z ~ 0.25 leading to a sample of massive clusters that extends to high redshift. The median mass of the sample is M (500c)(ρ(crit)) $\\sim 3.5\\times 10^{14}\\,M_\\odot \\,h_{70}^{-1}$, the median redshift is z (med) = 0.55, and the highest-redshift systems are at z > 1.4. The combination of large redshift extent, clean selection, and high typical mass makes this cluster sample of particular interest for cosmological analyses and studies of cluster formation and evolution.

  1. g-Anisotropy of the S2-state manganese cluster in single crystals of cyanobacterial photosystem II studied by W-band electron paramagnetic resonance spectroscopy.

    Science.gov (United States)

    Matsuoka, Hideto; Furukawa, Ko; Kato, Tatsuhisa; Mino, Hiroyuki; Shen, Jian-Ren; Kawamori, Asako

    2006-07-06

    The multiline signal from the S2-state manganese cluster in the oxygen evolving complex of photosystem II (PSII) was observed in single crystals of a thermophilic cyanobacterium Thermosynechococcus vulcanus for the first time by W-band (94 GHz) electron paramagnetic resonance (EPR). At W-band, spectra were characterized by the g-anisotropy, which enabled the precise determination of the tensor. Distinct hyperfine splittings (hfs's) as seen in frozen solutions of PSII at X-band (9.5 GHz) were detected in most of the crystal orientations relative to the magnetic field. In some orientations, however, the hfs's disappeared due to overlapping of a large number of EPR lines from eight crystallographic symmetry-related sites of the manganese cluster within the unit cell of the crystal. Analysis of the orientation-dependent spectral features yielded the following g-tensor components: g(x) = 1.988, g(y) = 1.981, g(z) = 1.965. The principal values suggested an approximate axial symmetry around the Mn(III) ion in the cluster.

  2. Nitrate-bridged "pseudo-double-propeller"-type lanthanide(III)-copper(II) heterometallic clusters: syntheses, structures, and magnetic properties.

    Science.gov (United States)

    Chaudhari, Abhijeet K; Joarder, Biplab; Rivière, Eric; Rogez, Guillaume; Ghosh, Sujit K

    2012-09-03

    Two discrete nitrate-bridged novel "pseudo-double-propeller"-shaped hexanuclear Cu/Ln clusters of the formula [Cu(4)Ln(2)L(4)L'(4)(NO(3))(2)(OH(2))(2)]·3NO(3)·4H(2)O [Ln = Dy, Gd; LH = o-vanilin; L'H = 2-(hydroxyethyl)pyridine] were synthesized and characterized. Single-crystal X-ray diffraction studies revealed the trimeric half-propeller-type Cu(2)/Ln core connected to other opposite-handed similar trimers by a bridging nitrate ligand. The Dy analogue, [Cu(4)Dy(2)L(4)L'(4)(NO(3))(2)(OH(2))(2)]·3NO(3)·4H(2)O, shows frequency-dependent out-of-phase alternating-current magnetic susceptibility, which indicates that this novel discrete [Cu(4)Dy(2)] heterometallic cluster may exhibit single-molecule-magnet behavior.

  3. Environmental Effects on Galaxy Evolution. II. Quantifying the Tidal Features in NIR Images of the Cluster Abell 85

    Science.gov (United States)

    Venkatapathy, Y.; Bravo-Alfaro, H.; Mayya, Y. D.; Lobo, C.; Durret, F.; Gamez, V.; Valerdi, M.; Granados-Contreras, A. P.; Navarro-Poupard, F.

    2017-12-01

    This work is part of a series of papers devoted to investigating the evolution of cluster galaxies during their infall. In the present article, we image in NIR a selected sample of galaxies throughout the massive cluster Abell 85 (z = 0.055). We obtain (JHK‧) photometry for 68 objects, reaching ˜1 mag arcsec-2 deeper than 2MASS. We use these images to unveil asymmetries in the outskirts of a sample of bright galaxies and develop a new asymmetry index, {α }{An}, which allows us to quantify the degree of disruption by the relative area occupied by the tidal features on the plane of the sky. We measure the asymmetries for a subsample of 41 large-area objects, finding clear asymmetries in 10 galaxies; most of these are in groups and pairs projected at different clustercentric distances, and some of them are located beyond R 500. Combining information on the H I gas content of blue galaxies and the distribution of substructures across Abell 85 with the present NIR asymmetry analysis, we obtain a very powerful tool to confirm that tidal mechanisms are indeed present and are currently affecting a fraction of galaxies in Abell 85. However, when comparing our deep NIR images with UV blue images of two very disrupted (jellyfish) galaxies in this cluster, we discard the presence of tidal interactions down to our detection limit. Our results suggest that ram-pressure stripping is at the origin of such spectacular disruptions. We conclude that across a complex cluster like Abell 85, environmental mechanisms, both gravitational and hydrodynamical, are playing an active role in driving galaxy evolution.

  4. Vaccination Coverage Cluster Surveys in Middle Dreib - Akkar, Lebanon: Comparison of Vaccination Coverage in Children Aged 12-59 Months Pre- and Post-Vaccination Campaign.

    Science.gov (United States)

    Rossi, Rodolfo; Assaad, Ramia; Rebeschini, Arianna; Hamadeh, Randa

    2016-01-01

    With the high proportion of refugee population throughout Lebanon and continuous population movement, it is sensible to believe that, in particular vulnerable areas, vaccination coverage may not be at an optimal level. Therefore, we assessed the vaccination coverage in children under 5 in a district of the Akkar governorate before and after a vaccination campaign. During the vaccination campaign, conducted in August 2015, 2,509 children were vaccinated. We conducted a pre- and post-vaccination campaign coverage surveys adapting the WHO EPI cluster survey to the Lebanese MoPH vaccination calendar. Percentages of coverage for each dose of each vaccine were calculated for both surveys. Factors associated with complete vaccination were explored. Comparing the pre- with the post-campaign surveys, coverage for polio vaccine increased from 51.9% to 84.3%, for Pentavalent from 49.0% to 71.9%, for MMR from 36.2% to 61.0%, while the percentage of children with fully updated vaccination calendar increased from 32.9% to 53.8%. While Lebanese children were found to be better covered for some antigens compared to Syrians at the first survey, this difference disappeared at the post-campaign survey. Awareness and logistic obstacles were the primary reported causes of not complete vaccination in both surveys. Vaccination campaigns remain a quick and effective approach to increase vaccination coverage in crisis-affected areas. However, campaigns cannot be considered as a replacement of routine vaccination services to maintain a good level of coverage.

  5. Solution of the explosive percolation quest. II. Infinite-order transition produced by the initial distributions of clusters.

    Science.gov (United States)

    da Costa, R A; Dorogovtsev, S N; Goltsev, A V; Mendes, J F F

    2015-03-01

    We describe the effect of power-law initial distributions of clusters on ordinary percolation and its generalizations, specifically, models of explosive percolation processes based on local optimization. These aggregation processes were shown to exhibit continuous phase transitions if the evolution starts from a set of disconnected nodes. Since the critical exponents of the order parameter in explosive percolation transitions turned out to be very small, these transitions were first believed to be discontinuous. In this article we analyze the evolution starting from clusters of nodes whose sizes are distributed according to a power law. We show that these initial distributions change dramatically the position and order of the phase transitions in these problems. We find a particular initial power-law distribution producing a peculiar effect on explosive percolation, namely, before the emergence of the percolation cluster, the system is in a "critical phase" with an infinite generalized susceptibility. This critical phase is absent in ordinary percolation models with any power-law initial conditions. The transition from the critical phase is an infinite-order phase transition, which resembles the scenario of the Berezinskii-Kosterlitz-Thouless phase transition. We obtain the critical singularity of susceptibility at this peculiar infinite-order transition in explosive percolation. It turns out that susceptibility in this situation does not obey the Curie-Weiss law.

  6. A MEGACAM SURVEY OF OUTER HALO SATELLITES. II. BLUE STRAGGLERS IN THE LOWEST STELLAR DENSITY SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Santana, Felipe A.; Munoz, Ricardo R. [Departamento de Astronomia, Universidad de Chile, Camino El Observatorio 1515, Las Condes, Santiago (Chile); Geha, Marla [Astronomy Department, Yale University, New Haven, CT 06520 (United States); Cote, Patrick; Stetson, Peter [Herzberg Institute of Astrophysics, National Research Council of Canada, Victoria, BC, V9E 2E7 (Canada); Simon, Joshua D. [Observatories of the Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Djorgovski, S. G., E-mail: fsantana@das.uchile.cl, E-mail: rmunoz@das.uchile.cl [Astronomy Department, California Institute of Technology, Pasadena, CA, 91125 (United States)

    2013-09-10

    We present a homogeneous study of blue straggler stars across 10 outer halo globular clusters, 3 classical dwarf spheroidal galaxies, and 9 ultra-faint galaxies based on deep and wide-field photometric data taken with MegaCam on the Canada-France-Hawaii Telescope. We find blue straggler stars to be ubiquitous among these Milky Way satellites. Based on these data, we can test the importance of primordial binaries or multiple systems on blue straggler star formation in low-density environments. For the outer halo globular clusters, we find an anti-correlation between the specific frequency of blue stragglers and absolute magnitude, similar to that previously observed for inner halo clusters. When plotted against density and encounter rate, the frequency of blue stragglers is well fit by a single trend with a smooth transition between dwarf galaxies and globular clusters; this result points to a common origin for these satellites' blue stragglers. The fraction of blue stragglers stays constant and high in the low encounter rate regime spanned by our dwarf galaxies, and decreases with density and encounter rate in the range spanned by our globular clusters. We find that young stars can mimic blue stragglers in dwarf galaxies only if their ages are 2.5 {+-} 0.5 Gyr and they represent {approx}1%-7% of the total number of stars, which we deem highly unlikely. These results point to mass-transfer or mergers of primordial binaries or multiple systems as the dominant blue straggler formation mechanism in low-density systems.

  7. Militarization, human rights violations and community responses as determinants of health in southeastern Myanmar: results of a cluster survey.

    Science.gov (United States)

    Davis, William W; Mullany, Luke C; Schissler, Matt; Albert, Saw; Beyrer, Chris

    2015-01-01

    The Myanmar army and ethnic armed groups agreed to a preliminary ceasefire in 2012, but a heavy military presence remains in southeastern Myanmar. Qualitative data suggested this militarization can result in human rights abuses in the absence of armed engagements between the parties, and that rural ethnic civilians use a variety of self-protection strategies to avoid these abuses or reduce their negative impacts. We used data from a household survey to determine prevalence of select self-protection activities and to examine exposure to armed groups, human rights violations and self-protection activities as determinants of health in southeastern Myanmar. Data collected from 463 households via a two-stage cluster survey of conflict-affected areas in eastern Myanmar in January 2012, were analyzed using logistic regression models to identify associations between exposure to state and non-state armed groups, village self-protection, human rights abuses and health outcomes. Close proximity to a military base was associated with human rights abuses (PRR 1.30, 95 % CI: 1.14-1.48), inadequate food production (PRR 1.08, 95 % CI: 1.03-1.13), inability to access health care (PRR 1.29, 95 % CI: 1.04-1.60) and diarrhea (PRR 1.15, 95 % CI: 1.05-1.27. Direct exposure to armed groups was associated with household hunger (PRR1.71, 95 % CI: 1.30-2.23). Among households that reported no human rights abuses, risk of household hunger (PRR 5.64, 95 % CI: 1.88-16.91), inadequate food production (PRR 1.95, 95 % CI: 1.11-3.41) and diarrhea (PRR 2.53, 95 % CI: 1.45-4.42) increased when neighbors' households reported experiencing human rights abuses. Households in villages that reported negotiating with the Myanmar army had lower risk of human rights violations (PRR 0.91, 95 % CI: 0.85-0.98), household hunger (PRR 0.85, 95 % CI: 0.74-0.96), inadequate food production (PRR 0.93, 95 % CI:0.89-0.98) and diarrhea (PRR 0.89, 95 % CI:0.82-0.97). Stratified analysis suggests that self

  8. Hunting for stellar streams in the solar neighbourhood with the SDSS and GSC-II kinematic survey

    Science.gov (United States)

    Re Fiorentin, P.; Lattanzi, M. G.; Smart, R. L.; Spagna, A.; Bailer-Jones, C. A. L.; Beers, T. C.; Zwitter, T.

    The growing awareness of the importance of the fossil record in the Milky Way for constraining galaxy formation theory is reflected by the increasing number of new ground- and space-based surveys designed to unravel the formation history of the Galaxy. Recently, a new kinematic survey has been produced by means of spectro-photometric data from the Sloan Digital Sky Survey (SDSS-DR7) and high-quality proper motions derived from multiepoch positions from the Guide Star Catalogue II (GSC-II). In this framework, we assembled a sample of ~ 30 000 FGK nearby metal-poor (sub)dwarfs for which selection and distance estimates take advantage of accurate stellar atmospheric parameters (effective temperature, surface gravity and metallicity) derived from SDSS spectra. Here, as one of the most interesting applications of this catalogue, we consider the feasibility of probing fossil signatures of the formation of the Milky Way by selecting and analysing subsamples of stars as tracers of the seven-dimensional space distribution (full phase-space coordinates plus chemical abundance) of the Galactic halo population within a few kiloparsecs from the Sun. Preliminary results exhibit statistical evidence for discrete overdensities localised in kinematics and in the space of adiabatic invariants (angular momentum and energy). By examination of their intrinsic properties, we suggest that they may be possible fossil signatures of past mergers or other accretion events.

  9. XMM-Newton/Sloan Digital Sky Survey: Star Formation Efficiency in Galaxy Clusters and Constraints on the Matter-density Parameter

    Science.gov (United States)

    Laganá, Tatiana F.; Zhang, Yu-Ying; Reiprich, Thomas H.; Schneider, Peter

    2011-12-01

    It is believed that the global baryon content of clusters of galaxies is representative of the matter distribution of the universe, and can, therefore, be used to reliably determine the matter-density parameter Ωm. This assumption is challenged by the growing evidence from optical and X-ray observations that the total baryon mass fraction increases toward rich clusters. In this context, we investigate the dependence of stellar and total baryon mass fractions as a function of mass. To do so, we used a subsample of 19 clusters extracted from the X-ray flux-limited sample HIFLUGCS that have available Sloan Digital Sky Survey Data Release 7 data. From the optical analysis we derived the stellar masses. Using XMM-Newton we derived the gas masses. Then, adopting a scaling relation we estimate the total masses. Adding the gas and the stellar mass fractions we obtain the total baryonic content that we find to increase with cluster mass, reaching seven-year Wilkinson Microwave Anisotropy Probe (WMAP7) prediction for clusters with M 500 = 1.6 × 1015 M ⊙. We observe a decrease of the stellar mass fraction (from 4.5% to ~1.0%) with increasing total mass where our findings for the stellar mass fraction agree with previous studies. This result suggests a difference in the number of stars formed per unit of halo mass, though with a large scatter for low-mass systems. That is, the efficiency of star formation varies on a cluster scale that lower mass systems are likely to have higher star formation efficiencies. It follows immediately that the dependence of the stellar mass fraction on total mass results in an increase of the mass-to-light ratio from lower to higher mass systems. We also discuss the consequences of these results in the context of determining the cosmic matter-density parameter Ωm.

  10. Consumer clusters in Denmark based on coarse vegetable intake frequency, explained by hedonics, socio-demographic, health and food lifestyle factors. A cross-sectional national survey.

    Science.gov (United States)

    Beck, Tove K; Jensen, Sidsel; Simmelsgaard, Sonni Hansen; Kjeldsen, Chris; Kidmose, Ulla

    2015-08-01

    Vegetable intake seems to play a protective role against major lifestyle diseases. Despite this, the Danish population usually eats far less than the recommended daily intake. The present study focused on the intake of 17 coarse vegetables and the potential barriers limiting their intake. The present study drew upon a large Danish survey (n = 1079) to study the intake of coarse vegetables among Danish consumers. Four population clusters were identified based on their intake of 17 different coarse vegetables, and profiled according to hedonics, socio-demographic, health, and food lifestyle factors. The four clusters were characterized by a very low intake frequency of coarse vegetables ('low frequency'), a low intake frequency of coarse vegetables; but high intake frequency of carrots ('carrot eaters'), a moderate coarse vegetable intake frequency and high intake frequency of beetroot ('beetroot eaters'), and a high intake frequency of all coarse vegetables ('high frequency'). There was a relationship between reported liking and reported intake frequency for all tested vegetables. Preference for foods with a sweet, salty or bitter taste, in general, was also identified to be decisive for the reported vegetable intake, as these differed across the clusters. Each cluster had distinct socio-demographic, health and food lifestyle profiles. 'Low frequency' was characterized by uninvolved consumers with lack of interest in food, 'carrot eaters' vegetable intake was driven by health aspects, 'beetroot eaters' were characterized as traditional food consumers, and 'high frequency' were individuals with a strong food engagement and high vegetable liking. 'Low frequency' identified more barriers than other consumer clusters and specifically regarded low availability of pre-cut/prepared coarse vegetables on the market as a barrier. Across all clusters a low culinary knowledge was identified as the main barrier. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. XMM-NEWTON/SLOAN DIGITAL SKY SURVEY: STAR FORMATION EFFICIENCY IN GALAXY CLUSTERS AND CONSTRAINTS ON THE MATTER-DENSITY PARAMETER

    Energy Technology Data Exchange (ETDEWEB)

    Lagana, Tatiana F. [Universidade de Sao Paulo, Instituto de Astronomia, Geofisica e Ciencias Atmosfericas, Departamento de Astronomia, Cidade Universitaria, CEP:05508-090, Sao Paulo, SP (Brazil); Zhang Yuying; Reiprich, Thomas H.; Schneider, Peter [Argelander-Institut fuer Astronomie, Universitaet Bonn, 53121 Bonn (Germany)

    2011-12-10

    It is believed that the global baryon content of clusters of galaxies is representative of the matter distribution of the universe, and can, therefore, be used to reliably determine the matter-density parameter {Omega}{sub m}. This assumption is challenged by the growing evidence from optical and X-ray observations that the total baryon mass fraction increases toward rich clusters. In this context, we investigate the dependence of stellar and total baryon mass fractions as a function of mass. To do so, we used a subsample of 19 clusters extracted from the X-ray flux-limited sample HIFLUGCS that have available Sloan Digital Sky Survey Data Release 7 data. From the optical analysis we derived the stellar masses. Using XMM-Newton we derived the gas masses. Then, adopting a scaling relation we estimate the total masses. Adding the gas and the stellar mass fractions we obtain the total baryonic content that we find to increase with cluster mass, reaching seven-year Wilkinson Microwave Anisotropy Probe (WMAP7) prediction for clusters with M{sub 500} = 1.6 Multiplication-Sign 10{sup 15} M{sub Sun }. We observe a decrease of the stellar mass fraction (from 4.5% to {approx}1.0%) with increasing total mass where our findings for the stellar mass fraction agree with previous studies. This result suggests a difference in the number of stars formed per unit of halo mass, though with a large scatter for low-mass systems. That is, the efficiency of star formation varies on a cluster scale that lower mass systems are likely to have higher star formation efficiencies. It follows immediately that the dependence of the stellar mass fraction on total mass results in an increase of the mass-to-light ratio from lower to higher mass systems. We also discuss the consequences of these results in the context of determining the cosmic matter-density parameter {Omega}{sub m}.

  12. Solving a bi-objective location routing problem by a NSGA-II combined with clustering approach: application in waste collection problem

    Science.gov (United States)

    Rabbani, Masoud; Farrokhi-Asl, Hamed; Asgarian, Bahare

    2017-10-01

    It is observed that the separated design of location for depots and routing for servicing customers often reach a suboptimal solution. So, solving location and routing problem simultaneously could achieve better results. In this paper, waste collection problem is considered with regard to economic and societal objective functions. A non-dominated sorting genetic algorithm (NSGA-II) is used to locate depots and treatment facilities and design the routes starting from depots to serve customers. A new mathematical model is proposed and two objective functions including economic objective (opening cost of depots and treatment facility and transportation cost) and societal objective; that is, negative impact of treatment facilities which are close to towns are addressed in this study. A straightforward order based solution representation is applied for coding solutions of the problem and clustering approach is used to generate appropriate initial solutions. Moreover, three multi-objective decomposition methods including weighted sum, goal programming, and goal attainment are applied to validate the performance of the proposed algorithm. Number of test problems are conducted and the results obtained by algorithms are compared with respect to some comparison metrics. Finally, the experimental results show that the proposed hybrid NSGA-II outperforms all decomposition methods, but the computational times for decomposition methods are less than NSGA-II.

  13. The Hubble space telescope UV legacy survey of galactic globular clusters. I. Overview of the project and detection of multiple stellar populations

    Energy Technology Data Exchange (ETDEWEB)

    Piotto, G.; Nardiello, D.; Cunial, A., E-mail: giampaolo.piotto@unipd.it, E-mail: domenico.nardiello@studenti.unipd.it, E-mail: andrea.cunial@studenti.unipd.it [Dipartimento di Fisica e Astronomia “Galileo Galilei,” Università di Padova, Vicolo dell’Osservatorio 3, I-35122 Padova (Italy); and others

    2015-03-01

    In this paper we describe a new UV-initiative Hubble Space Telescope project (GO-13297) that will complement the existing F606W and F814W database of the Advanced Camera for Surveys Globular Cluster (GC) Treasury by imaging most of its clusters through UV/blue WFC3/UVIS filters F275W, F336W, and F438W. This “magic trio” of filters has shown an uncanny ability to disentangle and characterize multiple population (MP) patterns in GCs in a way that is exquisitely sensitive to C, N, and O abundance variations. Combination of these passbands with those in the optical also gives the best leverage for measuring helium enrichment. The dozen clusters that had previously been observed in these bands exhibit a bewildering variety of MP patterns, and the new survey will map the full variance of the phenomenon. The ubiquity of multiple stellar generations in GCs has made the formation of these cornerstone objects more intriguing than ever; GC formation and the origin of their MPs have now become one and the same problem. In this paper we will describe the database and our data reduction strategy, as well as the uses we intend to make of the final photometry, astrometry, and PMs. We will also present preliminary color–magnitude diagrams from the data so far collected. These diagrams also draw on data from GO-12605 and GO-12311, which served as a pilot project for the present GO-13297.

  14. Materials used to restore class II lesions in primary molars: a survey of California pediatric dentists.

    Science.gov (United States)

    Pair, Rebecca Lee; Udin, Richard D; Tanbonliong, Thomas

    2004-01-01

    The purpose of this study was to determine which materials were most commonly used by pediatric dentists in California to restore Class II lesions in the primary dentition. A questionnaire consisting of 18 multiple-choice questions was mailed to all 440 active members of the California Society of Pediatric Dentistry (CSPD). The questions related to the practitioners' material of choice for restoring Class II lesions in primary molars. A 66% response rate was received. For 57% of the respondents, amalgam was the material of choice for restoration of Class II lesions in primary molars. Twenty-nine percent selected composite, 5% glass ionomer, 6% compomer, and 1% (1 practitioner) stainless steel crowns. Sixty-eight percent responded that amalgam has historically proven to be a safe, reliable, and affordable material. The main reasons cited for using composite resin were "patient preference" (86%) and "better esthetics" (78%). Most practitioners used either a single-step (fifth-generation) or 2-step (fourth-generation) bonding agent (53% and 35%, respectively). When using a nonamalgam restorative material, 49% of practitioners used a traditional Class II amalgam preparation. The role of dental literature in treatment decision-making was not significantly related to the restorative material used. While amalgam was the most common material used for Class II restorations, nonamalgam materials were significantly popular among California pediatric dentists.

  15. The KMOS Cluster Survey (KCS). I. The Fundamental Plane and the Formation Ages of Cluster Galaxies at Redshift 1.4 < z < 1.6

    Science.gov (United States)

    Beifiori, Alessandra; Mendel, J. Trevor; Chan, Jeffrey C. C.; Saglia, Roberto P.; Bender, Ralf; Cappellari, Michele; Davies, Roger L.; Galametz, Audrey; Houghton, Ryan C. W.; Prichard, Laura J.; Smith, Russell; Stott, John P.; Wilman, David J.; Lewis, Ian J.; Sharples, Ray; Wegner, Michael

    2017-09-01

    We present the analysis of the fundamental plane (FP) for a sample of 19 massive red-sequence galaxies (M\\star > 4× 1010 M⊙) in three known overdensities at 1.39 11) in our sample, we translate the FP zero-point evolution into a mass-to-light-ratio M/L evolution, finding Δlog M/LB= (-0.46+/-0.10)z, Δlog M/LB=(-0.52+/- 0.07)z, to Δlog M/LB=(-0.55+/- 0.10)z, respectively. We assess the potential contribution of the galaxy structural and stellar velocity dispersion evolution to the evolution of the FP zero-point and find it to be ˜6%-35% of the FP zero-point evolution. The rate of M/L evolution is consistent with galaxies evolving passively. Using single stellar population models, we find an average age of 2.33-0.51+0.86 Gyr for the log{M}\\star /M⊙> 11 galaxies in our massive and virialized cluster at z = 1.39, 1.59-0.62+1.40 Gyr in a massive but not virialized cluster at z = 1.46, and 1.20-0.47+1.03 Gyr in a protocluster at z = 1.61. After accounting for the difference in the age of the universe between redshifts, the ages of the galaxies in the three overdensities are consistent within the errors, with possibly a weak suggestion that galaxies in the most evolved structure are older. Based on observations obtained at the Very Large Telescope (VLT) of the European Southern Observatory (ESO), Paranal, Chile (ESO program IDs: 092.A-0210(A); 093.A-0051(A/B); 094.A-0578(A); 095.A-0137(A); 096.A0189(A); 097.A-0332(A). This work is further based on observations taken by the CANDELS Multi-cycle Treasury Program with the NASA/ESA HST, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

  16. Correlated behavior of the EPR signal of cytochrome b-559 heme Fe(III) ligated by OH- and the multiline signal of the Mn cluster in PS-II membrane fragments.

    Science.gov (United States)

    Fiege, R; Shuvalov, V A

    1996-05-27

    EPR signals of Cyt b-559 heme Fe(III) ligated by OH- and the multiline signal of the Mn cluster in PS-II membrane fragments have been investigated. In 2,3-dicyano-5,6-dichloro-p-benzoquinone-oxidized PS-II membrane fragments the light-induced decrease of the EPR signal of the heme Fe(III)-OH- is accompanied by the appearance of the EPR multiline signal of the Mn cluster. Addition of F- ions, which act as a stronger ligand for heme Fe(III) than OH-, decreases to the same extent the dark- and light-induced signal of the heme Fe(III)-OH- and the light-induced multiline signal of the Mn cluster. These results are discussed in terms of the light-induced formation of a bound OH' radical shared between the Cyt b-559 heme Fe and the Mn cluster as a first step of water oxidation.

  17. Galactic bulge population II Cepheids in the VVV survey: period-luminosity relations and a distance to the Galactic centre

    Science.gov (United States)

    Bhardwaj, A.; Rejkuba, M.; Minniti, D.; Surot, F.; Valenti, E.; Zoccali, M.; Gonzalez, O. A.; Romaniello, M.; Kanbur, S. M.; Singh, H. P.

    2017-09-01

    Context. Multiple stellar populations of different ages and metallicities reside in the Galactic bulge that trace its structure and provide clues to its formation and evolution. Aims: We present the near-infrared observations of population II Cepheids in the Galactic bulge from VISTA Variables in the Vía Láctea (VVV) survey. The JHKs photometry together with optical data from Optical Gravitational Lensing Experiment (OGLE) survey provide an independent estimate of the distance to the Galactic centre. The old, metal-poor and low-mass population II Cepheids are also investigated as useful tracers for the structure of the Galactic bulge. Methods: We identify 340 population II Cepheids in the VVV survey Galactic bulge catalogue based on their match with the OGLE-III Catalogue. The single-epoch JH and multi-epoch Ks observations complement the accurate periods and optical (VI) mean-magnitudes from OGLE. The sample consisting of BL Herculis and W Virginis subtypes is used to derive period-luminosity relations after correcting mean-magnitudes for the extinction. Our Ks-band period-luminosity relation, Ks = -2.189(0.056) [log (P)-1] + 11.187(0.032), is consistent with published work for BL Herculis and W Virginis variables in the Large Magellanic Cloud. Results: We present a combined OGLE-III and VVV catalogue with periods, classification, mean magnitudes, and extinction for 264 Galactic bulge population II Cepheids that have good-quality Ks-band light curves. The absolute magnitudes for population II Cepheids and RR Lyraes calibrated using Gaia and Hubble Space Telescope parallaxes, together with calibrated magnitudes for Large Magellanic Cloud population II Cepheids, are used to obtain a distance to the Galactic centre, R0 = 8.34 ± 0.03(stat.) ± 0.41(syst.), which changes by with different extinction laws. While noting the limitation of small number statistics, we find that the present sample of population II Cepheids in the Galactic bulge shows a nearly spheroidal

  18. Level II contamiant survey of the Tallahatchie National Wildlife Refuge, Quitman, Tallahatchie, and Grenada Counties, Mississippi

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Report contains findings of tissue and sediment samples for organic and inorganic contaminants as part of a preaquistion survey for Tallahatchie NWR. Elevated levels...

  19. Environmental monitoring survey of oil and gas fields in Region II in 2009. Summary report; Miljoeovervaaking av olje- og gassfelt i Region II i 2009

    Energy Technology Data Exchange (ETDEWEB)

    2010-03-15

    The oil companies Statoil ASA, ExxonMobil Exploration and Production Norway AS, Total E&P Norge AS, Talisman Energy Norge AS and Marathon Petroleum Norge AS commissioned Section of Applied Environmental Research at UNI RESEARCH AS to undertake the monitoring survey of Region II in 2009. Similar monitoring surveys in Region II have been carried out in 1996, 2000, 2003 and 2006. The survey in 2009 included in total 18 fields: Rev, Varg, Sigyn, Sleipner Vest, Sleipner OEst, Sleipner Alfa Nord, Glitne, Grane, Balder, Ringhorne, Jotun, Vale, Skirne, Byggve, Heimdal, Volve, Vilje og Alvheim. Sampling was conducted from the vessel MV Libas between May 18 and May 27. Samples were collected from in totally 137 sampling sites, of which 15 were regional sampling sites. Samples for chemical analysis were collected at all sites, whereas samples for benthos analysis were collected at 12 fields. As in previous surveys, Region II is divided into natural sub-regions. One sub-region is shallow (77-96 m) sub-region, a central sub-region (107-130 m) and a northern subregion (115-119 m). The sediments of the shallow sub-region had relatively lower content of TOM and pelite and higher content of fine sand than the central and northern sub-regions. Calculated areas of contamination are shown for the sub-regions in Table 1.1. The fields Sigyn, Sleipner Alfa Nord, Glitne, Grane, Balder, Ringhorne, Jotun, Skirne, Byggve, Vilje og Alvheim showed no contamination of THC. At the other fields there were minor changes from 2006. The concentrations of barium increased in the central sub-region from 2006 to 2009, also at fields where no drilling had been undertaken during the last years. The same laboratory and methods are used during the three last regional investigations. The changes in barium concentrations may be due to high variability of barium concentrations in the sediments. This is supported by relatively large variations in average barium concentrations at the regional sampling sites in

  20. Environmental monitoring survey of oil and gas fields in Region II in 2009. Summary report; Miljoeovervaaking av olje- og gassfelt i Region II i 2009. Sammendragsrapport

    Energy Technology Data Exchange (ETDEWEB)

    2010-03-15

    The oil companies Statoil ASA, ExxonMobil Exploration and Production Norway AS, Total E&P Norge AS, Talisman Energy Norge AS and Marathon Petroleum Norge AS commissioned Section of Applied Environmental Research at UNI RESEARCH AS to undertake the monitoring survey of Region II in 2009. Similar monitoring surveys in Region II have been carried out in 1996, 2000, 2003 and 2006. The survey in 2009 included in total 18 fields: Rev, Varg, Sigyn, Sleipner Vest, Sleipner Oest, Sleipner Alfa Nord, Glitne, Grane, Balder, Ringhorne, Jotun, Vale, Skirne, Byggve, Heimdal, Volve, Vilje og Alvheim. Sampling was conducted from the vessel MV Libas between May 18 and May 27. Samples were collected from in totally 137 sampling sites, of which 15 were regional sampling sites. Samples for chemical analysis were collected at all sites, whereas samples for benthos analysis were collected at 12 fields. As in previous surveys, Region II is divided into natural sub-regions. One sub-region is shallow (77-96 m) sub-region, a central sub-region (107-130 m) and a northern subregion (115-119 m). The sediments of the shallow sub-region had relatively lower content of TOM and pelite and higher content of fine sand than the central and northern sub-regions. Calculated areas of contamination are shown for the sub-regions in Table 1.1. The fields Sigyn, Sleipner Alfa Nord, Glitne, Grane, Balder, Ringhorne, Jotun, Skirne, Byggve, Vilje og Alvheim showed no contamination of THC. At the other fields there were minor changes from 2006. The concentrations of barium increased in the central sub-region from 2006 to 2009, also at fields where no drilling had been undertaken during the last years. The same laboratory and methods are used during the three last regional investigations. The changes in barium concentrations may be due to high variability of barium concentrations in the sediments. This is supported by relatively large variations in average barium concentrations at the regional sampling sites in

  1. Baryon acoustic oscillations in 2D. II. Redshift-space halo clustering in N-body simulations

    Science.gov (United States)

    Nishimichi, Takahiro; Taruya, Atsushi

    2011-08-01

    We measure the halo power spectrum in redshift space from cosmological N-body simulations, and test the analytical models of redshift distortions particularly focusing on the scales of baryon acoustic oscillations. Remarkably, the measured halo power spectrum in redshift space exhibits a large-scale enhancement in amplitude relative to the real-space clustering, and the effect becomes significant for the massive or highly biased halo samples. These findings cannot be simply explained by the so-called streaming model frequently used in the literature. By contrast, a physically motivated perturbation theory model developed in the previous paper reproduces the halo power spectrum very well, and the model combining a simple linear scale-dependent bias can accurately characterize the clustering anisotropies of halos in two dimensions, i.e., line-of-sight and its perpendicular directions. The results highlight the significance of nonlinear coupling between density and velocity fields associated with two competing effects of redshift distortions, i.e., Kaiser and Finger-of-God effects, and a proper account of this effect would be important in accurately characterizing the baryon acoustic oscillations in two dimensions.

  2. The evolution of the cluster optical galaxy luminosity function between z = 0.4 and 0.9 in the DAFT/FADA survey

    Science.gov (United States)

    Martinet, Nicolas; Durret, Florence; Guennou, Loïc; Adami, Christophe; Biviano, Andrea; Ulmer, Melville P.; Clowe, Douglas; Halliday, Claire; Ilbert, Olivier; Márquez, Isabel; Schirmer, Mischa

    2015-03-01

    Context. There is some disagreement about the abundance of faint galaxies in high-redshift clusters, with contradictory results in the literature arising from studies of the optical galaxy luminosity function (GLF) for small cluster samples. Aims: We compute GLFs for one of the largest medium-to-high-redshift (0.4 ≤ z DAFT/FADA survey in the B,V,R, and I rest-frame bands. We used photometric redshifts computed from BVRIZJ images to constrain galaxy cluster membership. We carried out a detailed estimate of the completeness of our data. We distinguished the red-sequence and blue galaxies using a V - I versus I colour-magnitude diagram. We studied the evolution of these two populations with redshift. We fitted Schechter functions to our stacked GLFs to determine average cluster characteristics. Results: We find that the shapes of our GLFs are similar for the B,V,R, and I bands with a drop at the red GLF faint ends that is more pronounced at high redshift: αred ~ -0.5 at 0.40 ≤ z 0.1 at 0.65 ≤ z < 0.90. The blue GLFs have a steeper faint end (αblue ~ -1.6) than the red GLFs, which appears to be independent of redshift. For the full cluster sample, blue and red GLFs meet at MV = -20, MR = -20.5, and MI = -20.3. A study of how galaxy types evolve with redshift shows that late-type galaxies appear to become early types between z ~ 0.9 and today. Finally, the faint ends of the red GLFs of more massive clusters appear to be richer than less massive clusters, which is more typical of the lower redshift behaviour. Conclusions: Our results indicate that these clusters form at redshifts higher than z = 0.9 from galaxy structures that already have an established red sequence. Late-type galaxies then appear to evolve into early types, enriching the red sequence between this redshift and today. This effect is consistent with the evolution of the faint-end slope of the red sequence and the galaxy type evolution that we find. Finally, faint galaxies accreted from the field

  3. Study of the Sextans dwarf spheroidal galaxy from the DART Ca II triplet survey

    NARCIS (Netherlands)

    Battaglia, G.; Tolstoy, E.; Helmi, A.; Irwin, M.; Parisi, P.; Hill, V.; Jablonka, P.

    We use Very Large Telescope (VLT)/Fibre Large Array Multi Element Spectrograph (FLAMES) intermediate-resolution (R˜ 6500) spectra of individual red giant branch stars in the near-infrared Ca II triplet (CaT) region to investigate the wide-area metallicity properties and internal kinematics of the

  4. Clustering of Galaxy Clusters at Intermediate Redshifts

    Science.gov (United States)

    Postman, Marc; Lauer, Tod R.; Oegerle, William

    2001-02-01

    We propose to continue a redshift survey of 141 objectively selected galaxy clusters to measure their clustering properties and constrain models of the formation of structure in the universe. This is the first redshift survey to probe cluster correlations on comoving scales of ~ 50h_75^-1 Mpc at z ~ 0.5 and will thus provide an original and important constraint on the evolution of large-scale structure. The cluster sample comes from our deep (I_AB ≤ 24), contiguous 16 deg^2 I-band KPNO 4-m survey. The proposed observations distinguish themselves from other ongoing distant cluster redshift work in that this survey will be able to provide meaningful constraints on the large-scale spatial distribution of moderate redshift clusters owing to the large angular area and contiguous geometry of the parent survey. The availability of the HET/LRS provides a highly efficient solution to the acquisition of redshifts for the 80 cluster candidates with 0.6 ≤ z_est ≤ 0.7. The systems with z_est > 0.6 are needed to assure complete sampling of the cluster population at z_obs ~ 0.5. The survey declination (52+/-2°) and observational strategy are extremely well-suited to the initial capabilities and queue observing mode of the HET. The 4m/RCSP is well suited to completing the survey of the z_est data. This survey began using the KPNO 4m to obtain redshifts for the 0.3 ≤ z_est < 0.6 sample. So far, we have observed 31 clusters and we're presently ~25% complete with the z_est < 0.6 observations (75% complete for z_est < 0.4). We have discovered at least 2 superclusters at z=0.23 and z=0.50.

  5. THE NEXT GENERATION VIRGO CLUSTER SURVEY. X. PROPERTIES OF ULTRA-COMPACT DWARFS IN THE M87, M49, AND M60 REGIONS

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chengze [Center for Astronomy and Astrophysics, Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Peng, Eric W.; Zhang, Hong-Xin [Department of Astronomy, Peking University, Beijing 100871 (China); Côté, Patrick; Ferrarese, Laura; Gwyn, Stephen; Blakeslee, John P. [Herzberg Institute of Astrophysics, National Research Council of Canada, Victoria, BC V9E 2E7 (Canada); Jordán, Andrés; Muñoz, Roberto P.; Puzia, Thomas H. [Instituto de Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, 7820436 Macul, Santiago (Chile); Mihos, J. Christopher [Department of Astronomy, Case Western Reserve University, Cleveland, OH (United States); Lançon, Ariane [Observatoire Astronomique de Strasbourg, Université de Strasbourg and CNRS, UMR 7550, 11 rue de l’Université, F-67000 Strasbourg (France); Cuillandre, Jean-Charles [CEA/IRFU/SAp, Laboratoire AIM Paris-Saclay, CNRS/INSU, Université Paris Diderot, Observatoire de Paris, PSL Research University, F-91191 Gif-sur-Yvette Cedex (France); Boselli, Alessandro [Aix-Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, F-13388, Marseille (France); Durrell, Patrick R., E-mail: czliu@sjtu.edu.cn, E-mail: peng@pku.edu.cn [Department of Physics and Astronomy, Youngstown State University, One University Plaza, Youngstown, OH 44555 (United States); and others

    2015-10-10

    We use imaging from the Next Generation Virgo cluster Survey (NGVS) to present a comparative study of ultra-compact dwarf (UCD) galaxies associated with three prominent Virgo sub-clusters: those centered on the massive red-sequence galaxies M87, M49, and M60. We show how UCDs can be selected with high completeness using a combination of half-light radius and location in color–color diagrams (u*iK{sub s} or u*gz). Although the central galaxies in each of these sub-clusters have nearly identical luminosities and stellar masses, we find large differences in the sizes of their UCD populations, with M87 containing ∼3.5 and 7.8 times more UCDs than M49 and M60, respectively. The relative abundance of UCDs in the three regions scales in proportion to sub-cluster mass, as traced by X-ray gas mass, total gravitating mass, number of globular clusters (GCs), and number of nearby galaxies. We find that the UCDs are predominantly blue in color, with ∼85% of the UCDs having colors similar to blue GCs and stellar nuclei of dwarf galaxies. We present evidence that UCDs surrounding M87 and M49 may follow a morphological sequence ordered by the prominence of their outer, low surface brightness envelope, ultimately merging with the sequence of nucleated low-mass galaxies, and that envelope prominence correlates with distance from either galaxy. Our analysis provides evidence that tidal stripping of nucleated galaxies is an important process in the formation of UCDs.

  6. THE GRISM LENS-AMPLIFIED SURVEY FROM SPACE (GLASS). V. EXTENT AND SPATIAL DISTRIBUTION OF STAR FORMATION IN z ∼ 0.5 CLUSTER GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Vulcani, Benedetta [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo Institutes for Advanced Study (UTIAS), the University of Tokyo, Kashiwa, 277-8582 (Japan); Treu, Tommaso; Malkan, Matthew; Abramson, Louis [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095-1547 (United States); Schmidt, Kasper B. [Department of Physics, University of California, Santa Barbara, CA 93106-9530 (United States); Poggianti, Bianca M. [INAF-Astronomical Observatory of Padova (Italy); Dressler, Alan [The Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Fontana, Adriano; Pentericci, Laura [INAF—Osservatorio Astronomico di Roma, Via Frascati 33, 00040 Monte Porzio Catone (Italy); Bradac, Marusa; Hoag, Austin; Huang, Kuan-Han; He, Julie [Department of Physics, University of California, Davis, CA 95616 (United States); Brammer, Gabriel B. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Trenti, Michele [School of Physics, University of Melbourne, VIC 3010 (Australia); Linden, Anja von der [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen Juliane Maries Vej 30, DK-2100 Copenhagen Ø (Denmark); Morris, Glenn [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, 452 Lomita Mall, Stanford, CA 94305-4085 (United States)

    2015-12-01

    We present the first study of the spatial distribution of star formation in z ∼ 0.5 cluster galaxies. The analysis is based on data taken with the Wide Field Camera 3 as part of the Grism Lens-Amplified Survey from Space (GLASS). We illustrate the methodology by focusing on two clusters (MACS 0717.5+3745 and MACS 1423.8+2404) with different morphologies (one relaxed and one merging) and use foreground and background galaxies as a field control sample. The cluster+field sample consists of 42 galaxies with stellar masses in the range 10{sup 8}–10{sup 11} M{sub ⊙} and star formation rates in the range 1–20 M{sub ⊙} yr{sup −1}. Both in clusters and in the field, Hα is more extended than the rest-frame UV continuum in 60% of the cases, consistent with diffuse star formation and inside-out growth. In ∼20% of the cases, the Hα emission appears more extended in cluster galaxies than in the field, pointing perhaps to ionized gas being stripped and/or star formation being enhanced at large radii. The peak of the Hα emission and that of the continuum are offset by less than 1 kpc. We investigate trends with the hot gas density as traced by the X-ray emission, and with the surface mass density as inferred from gravitational lens models, and find no conclusive results. The diversity of morphologies and sizes observed in Hα illustrates the complexity of the environmental processes that regulate star formation. Upcoming analysis of the full GLASS data set will increase our sample size by almost an order of magnitude, verifying and strengthening the inference from this initial data set.

  7. THE GOULD’S BELT DISTANCES SURVEY (GOBELINS). II. DISTANCES AND STRUCTURE TOWARD THE ORION MOLECULAR CLOUDS

    Energy Technology Data Exchange (ETDEWEB)

    Kounkel, Marina; Hartmann, Lee [Department of Astronomy, University of Michigan, 1085 S. University Street, Ann Arbor, MI 48109 (United States); Loinard, Laurent; Ortiz-León, Gisela N.; Rodríguez, Luis F.; Pech, Gerardo; Rivera, Juana L. [Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de Mexico, Morelia 58089 (Mexico); Mioduszewski, Amy J. [National Radio Astronomy Observatory, Domenici Science Operations Center, 1003 Lopezville Road, Socorro, NM 87801 (United States); Dzib, Sergio A. [Max Planck Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Torres, Rosa M. [Centro Universitario de Tonalá, Universidad de Guadalajara, Avenida Nuevo Perifrico No. 555, Ejido San José, Tatepozco, C.P. 48525, Tonalá, Jalisco, México (Mexico); Galli, Phillip A. B. [Université Grenoble Alpes, IPAG, F-38000, Grenoble (France); Boden, Andrew F. [Division of Physics, Math and Astronomy, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Evans II, Neal J. [Department of Astronomy, The University of Texas at Austin, 2515 Speedway, Stop C1400, Austin, TX 78712-1205 (United States); Briceño, Cesar [Cerro Tololo Interamerican Observatory, Casilla 603, La Serena (Chile); Tobin, John J., E-mail: mkounkel@umich.edu [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 West Brooks Street, Norman, OK 73019 (United States)

    2017-01-10

    We present the results of the Gould’s Belt Distances Survey of young star-forming regions toward the Orion Molecular Cloud Complex. We detected 36 young stellar objects (YSOs) with the Very Large Baseline Array, 27 of which have been observed in at least three epochs over the course of two years. At least half of these YSOs belong to multiple systems. We obtained parallax and proper motions toward these stars to study the structure and kinematics of the Complex. We measured a distance of 388 ± 5 pc toward the Orion Nebula Cluster, 428 ± 10 pc toward the southern portion L1641, 388 ± 10 pc toward NGC 2068, and roughly ∼420 pc toward NGC 2024. Finally, we observed a strong degree of plasma radio scattering toward λ Ori.

  8. Galaxy-galaxy lensing constraints on the relation between baryons and dark matter in galaxies in the Red Sequence Cluster Survey 2

    OpenAIRE

    van Uitert, Edo; Hoekstra, Henk; Velander, Malin; Gilbank, David G.; Gladders, Michael D.; Yee, H. K. C.

    2011-01-01

    We present the results of a study of weak gravitational lensing by galaxies using imaging data that were obtained as part of the second Red Sequence Cluster Survey (RCS2). In order to compare to the baryonic properties of the lenses we focus here on the ~300 square degrees that overlap with the DR7 of the SDSS. The depth and image quality of the RCS2 enables us to significantly improve upon earlier work for luminous galaxies at z>=0.3. Comparison with dynamical masses from the SDSS shows a go...

  9. The VLT-FLAMES Tarantula Survey. III. A very massive star in apparent isolation from the massive cluster R136

    NARCIS (Netherlands)

    Bestenlehner, J.M.; Vink, J.S.|info:eu-repo/dai/nl/212372971; Gräfener, G.; Najarro, F.; Evans, C.J.; Bastian, N.; Bonanos, A.Z.; Bressert, E.; Crowther, P.A.; Doran, E.; Friedrich, K.; Hénault-Brunet, V.; Herrero, A.; de Koter, A.; Langer, N.|info:eu-repo/dai/nl/304829498; Lennon, D.J.; Maíz Apellániz, J.; Sana, H.; Soszynski, I.; Taylor, W.D.

    2011-01-01

    VFTS 682 is located in an active star-forming region, at a projected distance of 29 pc from the young massive cluster R136 in the Tarantula Nebula of the Large Magellanic Cloud. It was previously reported as a candidate young stellar object, and more recently spectroscopically revealed as a

  10. mocca-SURVEY database I. Accreting white dwarf binary systems in globular clusters - III. Cataclysmic variables - implications of model assumptions

    Science.gov (United States)

    Belloni, Diogo; Zorotovic, Mónica; Schreiber, Matthias R.; Leigh, Nathan W. C.; Giersz, Mirek; Askar, Abbas

    2017-06-01

    In this third of a series of papers related to cataclysmic variables (CVs) and related objects, we analyse the population of CVs in a set of 12 globular cluster models evolved with the MOCCA Monte Carlo code, for two initial binary populations (IBPs), two choices of common-envelope phase (CEP) parameters, and three different models for the evolution of CVs and the treatment of angular momentum loss. When more realistic models and parameters are considered, we find that present-day cluster CV duty cycles are extremely low (≲0.1 per cent) that makes their detection during outbursts rather difficult. Additionally, the IBP plays a significant role in shaping the CV population properties, and models that follow the Kroupa IBP are less affected by enhanced angular momentum loss. We also predict from our simulations that CVs formed dynamically in the past few Gyr (massive CVs) correspond to bright CVs (as expected) and that faint CVs formed several Gyr ago (dynamically or not) represent the overwhelming majority. Regarding the CV formation rate, we rule out the notion that it is similar irrespective of the cluster properties. Finally, we discuss the differences in the present-day CV properties related to the IBPs, the initial cluster conditions, the CEP parameters, formation channels, the CV evolution models and the angular momentum loss treatments.

  11. Deconstructing dwarf galaxies: a Suprime-Cam survey of Andromeda II

    Science.gov (United States)

    McConnachie, Alan W.; Arimoto, Nobuo; Irwin, Mike

    2007-07-01

    We present deep, subhorizontal-branch, multicolour photometry of the Andromeda II dwarf spheroidal (And II dSph) taken with the Subaru Suprime-Cam wide-field camera. We identify a red clump population in this galaxy, the first time this feature has been detected in an M31 dSph, which are normally characterized as having no significant intermediate-age populations. We construct radial profiles for the various stellar populations and show that the horizontal branch (HB) has a nearly constant density spatial distribution out to large radius, whereas the reddest red giant branch stars are centrally concentrated in an exponential profile. We argue that these populations trace two distinct structural components in And II, and show that this assumption provides a good match to the overall radial profile of this galaxy. The extended component dominates the stellar populations at large radius, whereas the exponential component dominates the inner few arcminutes. By examining colour-magnitude diagrams in these regions, we show that the two components have very different stellar populations; the exponential component has an average age of ~7-10 Gyr, is relatively metal-rich ([Fe/H] ~ -1) but with a significant tail to low metallicities, and possesses a red clump. The extended component, on the other hand, is ancient (~13 Gyr), metal-poor ([Fe/H] ~ -1.5) with a narrower dispersion σ[Fe/H] ~= 0.28, and has a well-developed blue HB. The extended component contains approximately three-quarters of the light of And II and its unusual density profile is unique in Local Group dwarf galaxies. This suggests that its formation and/or evolution may have been quite different from other dwarf galaxies. The obvious chemodynamical complexity of And II lends further support to the accumulating body of evidence which shows that the evolutionary histories of faint dSph galaxies can be every bit as complicated as their brighter and more massive counterparts. Based on data collected at Subaru

  12. Vaccination Coverage Cluster Surveys in Middle Dreib - Akkar, Lebanon: Comparison of Vaccination Coverage in Children Aged 12-59 Months Pre- and Post-Vaccination Campaign.

    Directory of Open Access Journals (Sweden)

    Rodolfo Rossi

    Full Text Available With the high proportion of refugee population throughout Lebanon and continuous population movement, it is sensible to believe that, in particular vulnerable areas, vaccination coverage may not be at an optimal level. Therefore, we assessed the vaccination coverage in children under 5 in a district of the Akkar governorate before and after a vaccination campaign. During the vaccination campaign, conducted in August 2015, 2,509 children were vaccinated.We conducted a pre- and post-vaccination campaign coverage surveys adapting the WHO EPI cluster survey to the Lebanese MoPH vaccination calendar. Percentages of coverage for each dose of each vaccine were calculated for both surveys. Factors associated with complete vaccination were explored.Comparing the pre- with the post-campaign surveys, coverage for polio vaccine increased from 51.9% to 84.3%, for Pentavalent from 49.0% to 71.9%, for MMR from 36.2% to 61.0%, while the percentage of children with fully updated vaccination calendar increased from 32.9% to 53.8%. While Lebanese children were found to be better covered for some antigens compared to Syrians at the first survey, this difference disappeared at the post-campaign survey. Awareness and logistic obstacles were the primary reported causes of not complete vaccination in both surveys.Vaccination campaigns remain a quick and effective approach to increase vaccination coverage in crisis-affected areas. However, campaigns cannot be considered as a replacement of routine vaccination services to maintain a good level of coverage.

  13. Wide-Field Variability Survey of the Globular Cluster M 79 and a New Period-Luminosity Relation for SX Phe Stars

    Science.gov (United States)

    Kopacki, G.

    2015-03-01

    We present the results of a search for variable stars in a 26×39 arcmin2 field around globular cluster M 79 (NGC 1904). The search was made by means of an extended version of image subtraction, which allows us to analyze in a uniform manner CCD frames obtained with different telescopes and cameras of different sizes and resolutions. The search resulted in finding 20 new variable stars, among which 13 are cluster members. The members include one new RR Lyr star of subtype c, three SX Phe stars, and nine variable red giants. We also show that V7 is a W Vir star with a period of 13.985 d. Revised mean periods of RRab and RRc stars, ab=0.71 d and c=0.34 d, respectively, and relative percentage of RRc stars, Nc/(Nab+Nc)=45% confirm that M 79 belongs to the Oosterhoff II group of globular clusters. The mean V magnitude of the horizontal branch of M 79 based on ten RR Lyr stars has been estimated to be VHB=RR=16.11±0.03 mag. In one RRc star, V9, light changes with three close frequencies were detected, indicating excitation of nonradial modes. An SX Phe star, V18, is a double-mode pulsator with two radial modes excited, fundamental and first overtone. Moreover, we have discovered two SX Phe or δ Sct stars and one W UMa type system, all likely field objects. We also studied the period-luminosity relation for SX Phe stars. Using 62 fundamental and fundamentalized periods of radial double-mode and high-amplitude SX Phe stars known in Galactic globular clusters, we have derived the slope and zero point of this relation to be, -3.3±0.27 and 2.68±0.03 mag (at log(P/d)=-1.24), respectively.

  14. Clinical evaluation and grading practices in schools of nursing: national survey findings part II.

    Science.gov (United States)

    Oermann, Marilyn H; Yarbrough, Suzanne S; Saewert, Karen J; Ard, Nell; Charasika, Margie E

    2009-01-01

    To better understand how nurse educators evaluate and grade students' clinical practice, the Evaluation of Learning Advisory Council of the National League for Nursing conducted a survey of faculty (N = 1,573) in all types of prelicensure RN programs. This article describes the findings of that survey in relation to clinical evaluation and grading clinical practice. Nearly all faculty used a clinical evaluation tool to rate students' performance in the clinical setting (n = 1,534, 98 percent); most programs had the same basic tool in all courses, but modified to reflect the unique aspects of each course (n = 1,095, 70 percent). Faculty (n = 1,116, 83 percent) reported using pass/fail for grading in clinical courses rather than a letter or numerical grade.

  15. The infrared medium-deep survey. II. How to trigger radio AGNs? Hints from their environments

    Energy Technology Data Exchange (ETDEWEB)

    Karouzos, Marios; Im, Myungshin; Kim, Jae-Woo; Lee, Seong-Kook; Jeon, Yiseul; Choi, Changsu; Hong, Jueun; Hyun, Minhee; Jun, Hyunsung David; Kim, Dohyeong; Kim, Yongjung; Kim, Ji Hoon; Kim, Duho; Park, Won-Kee; Taak, Yoon Chan; Yoon, Yongmin [CEOU—Astronomy Program, Department of Physics and Astronomy, Seoul National University, Gwanak-gu, Seoul 151-742 (Korea, Republic of); Chapman, Scott [Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia (Canada); Pak, Soojong [School of Space Research, Kyung Hee University, Yongin-si, Gyeonggi-do 446-701 (Korea, Republic of); Edge, Alastair, E-mail: mkarouzos@astro.snu.ac.kr [Department of Physics, University of Durham, South Road, Durham, DH1 3LE (United Kingdom)

    2014-12-10

    Activity at the centers of galaxies, during which the central supermassive black hole is accreting material, is nowadays accepted to be rather ubiquitous and most probably a phase of every galaxy's evolution. It has been suggested that galactic mergers and interactions may be the culprits behind the triggering of nuclear activity. We use near-infrared data from the new Infrared Medium-Deep Survey and the Deep eXtragalactic Survey of the VIMOS-SA22 field and radio data at 1.4 GHz from the FIRST survey and a deep Very Large Array survey to study the environments of radio active galactic nuclei (AGNs) over an area of ∼25 deg{sup 2} and down to a radio flux limit of 0.1 mJy and a J-band magnitude of 23 mag AB. Radio AGNs are predominantly found in environments similar to those of control galaxies at similar redshift, J-band magnitude, and (M{sub u} – M{sub r} ) rest-frame color. However, a subpopulation of radio AGNs is found in environments up to 100 times denser than their control sources. We thus preclude merging as the dominant triggering mechanism of radio AGNs. By fitting the broadband spectral energy distribution of radio AGNs in the least and most dense environments, we find that those in the least dense environments show higher radio-loudness, higher star formation efficiencies, and higher accretion rates, typical of the so-called high-excitation radio AGNs. These differences tend to disappear at z > 1. We interpret our results in terms of a different triggering mechanism for these sources that is driven by mass loss through winds of young stars created during the observed ongoing star formation.

  16. Physicians' attitudes toward homosexuality and HIV: survey of a California Medical Society- revisited (PATHH-II).

    Science.gov (United States)

    Smith, Davey M; Mathews, Wm Christopher

    2007-01-01

    In 1982, Mathews et al. surveyed San Diego County Medical Society's (SDCMS) physicians about their attitudes toward homosexuality. They found significant differences in prevalence of homophobic attitudes by gender, year of medical school graduation, specialty, and practice setting. To assess current physicians' attitudes toward homosexuality and persons with HIV infection, an anonymous, self-administered, 17-item survey was mailed to all 4,385 members of the SDCMS and 1,271 UCSD physicians. The survey included items measuring attitudes toward homosexuality and toward entry to medical school and referral patterns, conditional on sexual orientation and HIV status of hypothetical referents. Only 3% of respondents would not admit a highly qualified homosexual applicant to medical school compared with 30% in 1982. Similarly, 9% would discontinue referrals to a gay pediatrician compared with 46% of respondents in 1982. Forty-two percent would not admit a "highly qualified but asymptomatic HIV-infected applicant with excellent response to antiretroviral therapy to medical school" and 66% would discontinue referral to a general surgeon known to be HIV infected. In multiple logistic regression analyses controlling for sex and medical school affiliation, significant (p attitudes toward homosexuals and year of graduation from medical school appear to be significant predictors of attitudes toward persons with HIV infection.

  17. Socioeconomic correlates of generalized anxiety disorder and major depression in primary care: the GADIS II study (Generalized Anxiety and Depression Impact Survey II).

    Science.gov (United States)

    Ansseau, Marc; Fischler, Benjamin; Dierick, Michel; Albert, Adelin; Leyman, Sophie; Mignon, Annick

    2008-01-01

    A previous Generalized Anxiety Disorder Impact Survey (GADIS I) performed on 15,399 Belgian patients consulting their primary care physicians, revealed high prevalences of generalized anxiety disorder (GAD) and major depression (MD) with important regional differences. The objective of this study (GADIS II) was to replicate previous findings and to evaluate the role of socioeconomic factors in the diagnoses of GAD and MD. A large-scale cross-sectional survey was conducted in a random sample of 377 general practitioners distributed geographically over Belgium and Luxemburg. Each physician was asked to screen 40 consecutive patients at predefined time periods for the presence of GAD and MD using sections of the Mini International Neuropsychiatric Interview (MINI). Socioeconomic parameters were collected. The level of impairment was assessed using the Sheehan Disability Scale. In a sample of 13,699 patients, point prevalences of GAD and of MD were found to be 13.4 and 11.0%, respectively. Overall, 17.8% of the population was positive for GAD and/or MD. Both disorders were significantly more frequent in women than in men. Marked regional differences were observed with prevalences for GAD and/or MD of 24.2% in Brussels, 22.7% in Wallonia, 13.6% in Luxemburg and 12.9% in Flanders. Several socioeconomic factors were significantly associated with positive diagnoses: living alone, a low level of education and unemployment. However, regional differences remained significant even after controlling for socioeconomic factors. The study confirms the high prevalence of GAD and MD in primary care and the role of several socioeconomic and regional factors in the illnesses.

  18. A two-stage cluster sampling method using gridded population data, a GIS, and Google EarthTM imagery in a population-based mortality survey in Iraq

    Directory of Open Access Journals (Sweden)

    Galway LP

    2012-04-01

    Full Text Available Abstract Background Mortality estimates can measure and monitor the impacts of conflict on a population, guide humanitarian efforts, and help to better understand the public health impacts of conflict. Vital statistics registration and surveillance systems are rarely functional in conflict settings, posing a challenge of estimating mortality using retrospective population-based surveys. Results We present a two-stage cluster sampling method for application in population-based mortality surveys. The sampling method utilizes gridded population data and a geographic information system (GIS to select clusters in the first sampling stage and Google Earth TM imagery and sampling grids to select households in the second sampling stage. The sampling method is implemented in a household mortality study in Iraq in 2011. Factors affecting feasibility and methodological quality are described. Conclusion Sampling is a challenge in retrospective population-based mortality studies and alternatives that improve on the conventional approaches are needed. The sampling strategy presented here was designed to generate a representative sample of the Iraqi population while reducing the potential for bias and considering the context specific challenges of the study setting. This sampling strategy, or variations on it, are adaptable and should be considered and tested in other conflict settings.

  19. Environmental survey of RCMP detachment building in Powell River, B.C., implicated in a cancer cluster.

    Science.gov (United States)

    van Netten, C; Brands, R; Teschke, K E; Ashwood-Smith, M J; Morley, D R; Ross, R N

    1995-01-01

    The rationale and approach are presented that were used to investigate the Powell River RCMP detachment building, perceived to have a higher than normal cancer incidence and whose occupants demanded to know whether the building was safe to work in. On the basis of the history of the building and the cancers observed, a set of carcinogens were looked for in areas where the worst conditions were expected. A positive result would initiate a second more in-depth survey. This was done for Fyrol-PCF, which was shown to be a contaminant of the charcoal adsorption tubes used. The results of the survey indicated a safe work environment. The chemical analyses, complemented by the bioassay and comparison with a recognizable control site, were found to be most effective in the acceptance of the results by the public. The conclusions from this survey were confirmed by the findings of an epidemiological survey.

  20. NEAR-INFRARED IMAGING AND SPECTROSCOPIC SURVEY OF THE SOUTHERN REGION OF THE YOUNG OPEN CLUSTER NGC 2264

    Energy Technology Data Exchange (ETDEWEB)

    Marinas, Naibi; Lada, Elizabeth A. [Astronomy Department, University of Florida, Gainesville, FL 32611 (United States); Teixiera, Paula S. [Department of Astrophysics, University of Vienna, Tuerkenschanzstrasse 17, A-1180 Vienna (Austria); Lada, Charles J. [Harvard-Smithsonian CFA, Cambridge, MA (United States)

    2013-08-01

    We have obtained JHK near-IR images and JH band low-resolution spectra of candidate members of the southern region of the young open cluster NGC 2264. We have determined spectral types from H-band spectra for 54 sources, 25 of which are classified for the first time. The stars in our sample cover a large range of spectral types (A8-M8). Using a cluster distance of 780 pc, we determined a median age of 1 Myr for this region of NGC 2264, with 90% of the stars being 5 Myr or younger. To improve the statistical significance of our sample, we included 66 additional cluster members within our field of view with optical spectral classification in the literature. We derived infrared excesses using stellar properties to model the photospheric emission for each source and the extinction to correct FLAMINGOS near-IR and Spitzer mid-IR photometry, and obtained a disk fraction of 51% {+-} 5% for the region. Binning the stars by stellar mass, we find a disk fraction of 38% {+-} 9% for the 0.1-0.3 solar mass group, 55% {+-} 6% for 0.3-1 solar masses, and 58% {+-} 10% for the higher than 1 solar mass group. The lower disk fraction for the lower mass stars is similar to the results found in non-cluster regions like Taurus and Chamaeleon, but differs from the older 3 Myr cluster IC 348 in which the disk fraction is lower for the higher mass stars. This mass-dependent disk fraction is accentuated in the sample with isochrone ages younger than 2 Myr. Here, we find that 45% {+-} 11% of the 0.1-0.3 solar mass stars have disks, 60% {+-} 7% of the 0.3-1 solar mass stars have disks, and all 1-3 solar mass stars have disks. Stellar masses might be an important factor in the ability of a system to form or retain a disk early on. However, regardless of the stellar mass, the large infrared excesses expected from optically thick disks disappear within the first 2 Myr for all stars in our study and small excesses from optically thin disks are found mostly in sources younger than 4 Myr.

  1. The Rise and Fall of Type Ia Supernova Light Curves in the SDSS-II Supernova Survey

    Energy Technology Data Exchange (ETDEWEB)

    Hayden, Brian T.; /Notre Dame U.; Garnavich, Peter M.; /Notre Dame U.; Kessler, Richard; /KICP, Chicago /Chicago U., EFI; Frieman, Joshua A.; /KICP, Chicago /Chicago U. /Fermilab; Jha, Saurabh W.; /Stanford U., Phys. Dept. /Rutgers U., Piscataway; Bassett, Bruce; /Cape Town U., Dept. Math. /South African Astron. Observ.; Cinabro, David; /Wayne State U.; Dilday, Benjamin; /Rutgers U., Piscataway; Kasen, Daniel; /UC, Santa Cruz; Marriner, John; /Fermilab; Nichol, Robert C.; /Portsmouth U., ICG /Baltimore, Space Telescope Sci. /Johns Hopkins U.

    2010-01-01

    We analyze the rise and fall times of Type Ia supernova (SN Ia) light curves discovered by the Sloan Digital Sky Survey-II (SDSS-II) Supernova Survey. From a set of 391 light curves k-corrected to the rest-frame B and V bands, we find a smaller dispersion in the rising portion of the light curve compared to the decline. This is in qualitative agreement with computer models which predict that variations in radioactive nickel yield have less impact on the rise than on the spread of the decline rates. The differences we find in the rise and fall properties suggest that a single 'stretch' correction to the light curve phase does not properly model the range of SN Ia light curve shapes. We select a subset of 105 light curves well observed in both rise and fall portions of the light curves and develop a '2-stretch' fit algorithm which estimates the rise and fall times independently. We find the average time from explosion to B-band peak brightness is 17.38 {+-} 0.17 days, but with a spread of rise times which range from 13 days to 23 days. Our average rise time is shorter than the 19.5 days found in previous studies; this reflects both the different light curve template used and the application of the 2-stretch algorithm. The SDSS-II supernova set and the local SNe Ia with well-observed early light curves show no significant differences in their average rise-time properties. We find that slow-declining events tend to have fast rise times, but that the distribution of rise minus fall time is broad and single peaked. This distribution is in contrast to the bimodality in this parameter that was first suggested by Strovink (2007) from an analysis of a small set of local SNe Ia. We divide the SDSS-II sample in half based on the rise minus fall value, t{sub r} - t{sub f} {approx}< 2 days and t{sub r} - t{sub f} > 2 days, to search for differences in their host galaxy properties and Hubble residuals; we find no difference in host galaxy properties or Hubble

  2. The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: Cosmological implications of the Fourier space wedges of the final sample

    Science.gov (United States)

    Grieb, Jan Niklas; Sánchez, Ariel G.; Salazar-Albornoz, Salvador; Scoccimarro, Román; Crocce, Martín; Dalla Vecchia, Claudio; Montesano, Francesco; Gil-Marín, Héctor; Ross, Ashley J.; Beutler, Florian; Rodríguez-Torres, Sergio; Chuang, Chia-Hsun; Prada, Francisco; Kitaura, Francisco-Shu; Cuesta, Antonio J.; Eisenstein, Daniel J.; Percival, Will J.; Vargas-Magaña, Mariana; Tinker, Jeremy L.; Tojeiro, Rita; Brownstein, Joel R.; Maraston, Claudia; Nichol, Robert C.; Olmstead, Matthew D.; Samushia, Lado; Seo, Hee-Jong; Streblyanska, Alina; Zhao, Gong-bo

    2017-05-01

    We extract cosmological information from the anisotropic power-spectrum measurements from the recently completed Baryon Oscillation Spectroscopic Survey (BOSS), extending the concept of clustering wedges to Fourier space. Making use of new fast-Fourier-transform-based estimators, we measure the power-spectrum clustering wedges of the BOSS sample by filtering out the information of Legendre multipoles ℓ > 4. Our modelling of these measurements is based on novel approaches to describe non-linear evolution, bias and redshift-space distortions, which we test using synthetic catalogues based on large-volume N-body simulations. We are able to include smaller scales than in previous analyses, resulting in tighter cosmological constraints. Using three overlapping redshift bins, we measure the angular-diameter distance, the Hubble parameter and the cosmic growth rate, and explore the cosmological implications of our full-shape clustering measurements in combination with cosmic microwave background and Type Ia supernova data. Assuming a Λ cold dark matter (ΛCDM) cosmology, we constrain the matter density to Ω M= 0.311_{-0.010}^{+0.009} and the Hubble parameter to H_0 = 67.6_{-0.6}^{+0.7} km s^{-1 Mpc^{-1}}, at a confidence level of 68 per cent. We also allow for non-standard dark energy models and modifications of the growth rate, finding good agreement with the ΛCDM paradigm. For example, we constrain the equation-of-state parameter to w = -1.019_{-0.039}^{+0.048}. This paper is part of a set that analyses the final galaxy-clustering data set from BOSS. The measurements and likelihoods presented here are combined with others in Alam et al. to produce the final cosmological constraints from BOSS.

  3. HiZELS: a high-redshift survey of Hα emitters - I. The cosmic star formation rate and clustering at z = 2.23

    Science.gov (United States)

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

    2008-08-01

    We present results from a near-infrared narrow-band survey of emission-line galaxies at z = 2.23, using the Wide Field Camera on the United Kingdom Infrared Telescope. The H2S1 narrow-band filter (λc = 2.121μm) we employ selects the Hα emission-line redshifted to z = 2.23, and is thus suitable for selecting `typical' star-forming galaxies and active galactic nuclei at this epoch. The pilot study was undertaken in the well-studied Cosmological Evolution Survey field (COSMOS) and is already the largest near-infrared narrow-band survey at this depth, with a line flux limit of FHα ~ 10-16ergs-1cm-2 over 0.60deg2, probing ~220 × 103Mpc3 (comoving) down to a limiting star formation rate of ~30Msolaryr-1 (3σ). In this paper, we present the results from our pilot survey and evaluate the Hα luminosity function and estimate the clustering properties of Hα emitters at z = 2.23 from 55 detected galaxies. The integrated luminosity function is used to estimate the volume-averaged star formation rate at z = 2.23: ρSFR = 0.17+0.16-0.09Msolaryr-1Mpc-3 for LHα > 1042ergs-1. For the first time, we use the Hα star formation tracer to reliably constrain ρSFR out to z = 2.23 demonstrating the rapid increase in ρSFR out to this redshift as well as confirming the flattening in ρSFR between z ~ 1 and 2. In addition to the luminosity distribution, we analyse the clustering properties of these galaxies. Using the two-point angular correlation function, ω(θ), we estimate a real-space correlation length of r0 = 4.2+0.4-0.2h-1Mpc. In comparison to models of clustering which take into account bias evolution, we estimate that these galaxies are hosted by dark matter haloes of mass Mhalo ~ 1012Msolar consistent with the progenitors of the Milky Way. Based on observations obtained with the Wide Field CAMera (WFCAM) on the United Kingdom Infrared Telescope (UKIRT). E-mail: j.e.geach@durham.ac.uk

  4. Deep Chandra Survey of the Small Magellanic Cloud. II. Timing Analysis of X-Ray Pulsars

    Science.gov (United States)

    Hong, JaeSub; Antoniou, Vallia; Zezas, Andreas; Haberl, Frank; Sasaki, Manami; Drake, Jeremy J.; Plucinsky, Paul P.; Laycock, Silas

    2017-09-01

    We report the timing analysis results of X-ray pulsars from a recent deep Chandra survey of the Small Magellanic Cloud (SMC). We analyzed a total exposure of 1.4 Ms from 31 observations over a 1.2 deg2 region in the SMC under a Chandra X-ray Visionary Program. Using the Lomb-Scargle and epoch-folding techniques, we detected periodic modulations from 20 pulsars and a new candidate pulsar. The survey also covered 11 other pulsars with no clear sign of periodic modulation. The 0.5-8 keV X-ray luminosity (L X ) of the pulsars ranges from 1034 to 1037 erg s-1 at 60 kpc. All of the Chandra sources with L X ≳ 4 × 1035 erg s-1 exhibit X-ray pulsations. The X-ray spectra of the SMC pulsars (and high-mass X-ray binaries) are in general harder tha