Sample records for four-stage cluster sampling

  1. Brightest Cluster Galaxies in the Extended GMRT radio halo cluster sample. Radio properties and cluster dynamics

    E-Print Network [OSTI]

    Kale, Ruta; Cassano, Rossella; Giacintucci, Simona; Bardelli, sandro; Dallacasa, Daniele; Zucca, Elena

    2015-01-01T23:59:59.000Z

    Brightest Cluster Galaxies (BCGs) show exceptional properties over the whole electromagnetic spectrum. Their special location at the centres of galaxy clusters raises the question of the role of the environment on their radio properties. To decouple the effect of the galaxy mass and of the environment in their statistical radio properties, we investigate the possible dependence of the occurrence of radio loudness and of the fractional radio luminosity function on the dynamical state of the hosting cluster. We studied the radio properties of the BCGs in the Extended GMRT Radio Halo Survey (EGRHS). We obtained a statistical sample of 59 BCGs, which was divided into two classes, depending on the dynamical state of the host cluster, i.e. merging (M) and relaxed (R). Among the 59 BCGs, 28 are radio-loud, and 31 are radio--quiet. The radio-loud sources are located favourably located in relaxed clusters (71\\%), while the reverse is true for the radio-quiet BCGs, mostly located in merging systems (81\\%). The fraction...

  2. Investigating AGN Heating in a Sample of Nearby Clusters

    E-Print Network [OSTI]

    Dunn, R J H

    2006-01-01T23:59:59.000Z

    We analyse those objects in the Brightest 55 sample of clusters of galaxies which have a short central cooling time and a central temperature drop. Such clusters are likely to require some form of heating. Where clear radio bubbles are observed in these clusters, their energy injection is compared to the X-ray cooling rate. Of the 20 clusters requiring heating, at least 14 have clear bubbles, implying a duty cycle for the bubbling activity of at least 70 per cent. The average distance out to which the bubbles can offset the X-ray cooling, r_heat is given by r_heat/r_cool=0.86+/-0.11 where r_cool is defined as the radius as which the radiative cooling time is 3 Gyr. 10 out of 16 clusters have r_heat/r_cool>1, but there is a large range in values. The clusters which require heating but show no clear bubbles were combined with those clusters which have a radio core to form a second sub-sample. Using r_heat=0.86 r_cool we calculate the size of an average bubble expected in these clusters. In five cases (3C129.1, ...

  3. Four stage, fluidized bed gasification process minimizes NO{sub x}

    SciTech Connect (OSTI)

    Lewis, F.M.; Haug, R.T.

    1999-07-01T23:59:59.000Z

    In 1981, after a long and thorough study of alternative methods of sewage sludge (biosolids) disposal, the City of Los Angeles (CLA) embarked on a pilot test program to incinerate dried sewage sludge from its Hyperion Wastewater Treatment Plant. This dried sludge is typically 47% ash, 53% combustible, and has an average higher heating value (HHV), moisture, ash-free (MAF) of 10,675 Btu/Lbm. The dried sludge is called sludge derived fuel (SDF). Approximately 8% of the MAF fraction of SDF is fuel-bound nitrogen. When SDF, with its extremely high fuel-bound nitrogen, was combusted in conventional multiple hearth and fluidized bed pilot plant furnaces, NO{sub x} emissions were extremely high ({gt}1,000 ppm). Faced with this dilemma, the CLA initiated an R and D program to reduce NO{sub x}. The pilot tests with a sub-stoichiometric fluid bed and an excess air afterburner (two-stages) reduced NO{sub x} to 400--600 ppm. With one intermediate stage added (three-stage), NO{sub x} was reduced to 130--150 ppm. However, when the following four-stage process was developed and tested, NO{sub x} was reduced to 50--75 ppm. Stage 1: Sub-stoichiometric fluidized bed operating at a nominal 30% stoichiometric air (SA). Stage 2:Sub-stoichiometric zone operating at a nominal 80% SA. Stage 3: Stoichiometric zone operating at a nominal 100% SA. Stage 4: Excess air zone (Afterburner) operating at a nominal 135% SA (35% excess air). After pilot testing was complete and design parameters established, three full-size, fluid bed gasifiers (two operational--one standby) were designed, constructed and operated until 1996. This paper describes the design, operation, and emission testing of these four-stage fluid bed gasifiers with special emphasis on the problems of (a) pneumatic feeding of SDF powder into the pressurized bed and (b) baghouse fabrics (expanded PTEE membrane on PTFE scrim). Final emission test results for NO{sub x} and other criteria pollutants are also presented.

  4. Clustering of Unevenly Sampled Gene Expression Time-Series Data

    E-Print Network [OSTI]

    Rostock, Universität

    -means, k-means, average linkage hierarchical algorithm and random clustering are compared to the proposed the genes which define the model profiles in [2]. The fuzzy c-means, k- means, average linkage hierarchical as follows: The effects of the temporal information in the comparison of shapes are discussed first, followed

  5. On the occurrence of Radio Halos in galaxy clusters - Insight from a mass-selected sample

    E-Print Network [OSTI]

    Cuciti, V; Brunetti, G; Dallacasa, D; Kale, R; Ettori, S; Venturi, T

    2015-01-01T23:59:59.000Z

    Giant radio halos (RH) are diffuse Mpc-scale synchrotron sources detected in a fraction of massive and merging galaxy clusters. An unbiased study of the statistical properties of RHs is crucial to constrain their origin and evolution. We aim at investigating the occurrence of RHs and its dependence on the cluster mass in a SZ-selected sample of galaxy clusters, which is as close as possible to be a mass-selected sample. Moreover, we analyse the connection between RHs and merging clusters. We select from the Planck SZ catalogue (Planck Collaboration XXIX 2014) clusters with $M\\geq 6\\times10^{14} M_\\odot$ at z=0.08-0.33 and we search for the presence of RHs using the NVSS for z<0.2 and the GMRT RH survey (GRHS, Venturi et al. 2007, 2008) and its extension (EGRHS, Kale et al. 2013, 2015) for 0.2clusters dynamical status. We confirm that RH clusters are merging systems while the majority of clusters without RH are relaxed, thus supp...

  6. A simple D^2-sampling based PTAS for k-means and other Clustering Problems

    E-Print Network [OSTI]

    Jaiswal, Ragesh; Sen, Sandeep

    2012-01-01T23:59:59.000Z

    Given a set of points $P \\subset \\mathbb{R}^d$, the $k$-means clustering problem is to find a set of $k$ {\\em centers} $C = \\{c_1,...,c_k\\}, c_i \\in \\mathbb{R}^d,$ such that the objective function $\\sum_{x \\in P} d(x,C)^2$, where $d(x,C)$ denotes the distance between $x$ and the closest center in $C$, is minimized. This is one of the most prominent objective functions that have been studied with respect to clustering. $D^2$-sampling \\cite{ArthurV07} is a simple non-uniform sampling technique for choosing points from a set of points. It works as follows: given a set of points $P \\subseteq \\mathbb{R}^d$, the first point is chosen uniformly at random from $P$. Subsequently, a point from $P$ is chosen as the next sample with probability proportional to the square of the distance of this point to the nearest previously sampled points. $D^2$-sampling has been shown to have nice properties with respect to the $k$-means clustering problem. Arthur and Vassilvitskii \\cite{ArthurV07} show that $k$ points chosen as cente...

  7. REDSHIFT-DISTANCE SURVEY OF EARLY-TYPE GALAXIES. I. THE ENEARc CLUSTER SAMPLE1 M. Bernardi,2,3

    E-Print Network [OSTI]

    Maia, Marcio Antonio Geimba

    REDSHIFT-DISTANCE SURVEY OF EARLY-TYPE GALAXIES. I. THE ENEARc CLUSTER SAMPLE1 M. Bernardi,2,3 M. V subsample of the larger ENEAR survey of nearby early-type gal- axies. The ENEARc galaxies belong to clusters and were specifically chosen to be used for the construction of a Dn- template. The ENEARc sample includes

  8. Studies of the mechanism of the cluster formation in a thermally sampling atmospheric pressure ionization mass spectrometer

    SciTech Connect (OSTI)

    Albrecht, Sascha, E-mail: s.albrecht@fz-juelich.de; Stroh, Fred, E-mail: f.stroh@fz-juelich.de [Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research, Stratosphere (IEK-7), 52428 Jülich (Germany)] [Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research, Stratosphere (IEK-7), 52428 Jülich (Germany); Klopotowski, Sebastian, E-mail: s.klopotowski@uni-wuppertal.de; Derpmann, Valerie, E-mail: v.derpmann@uni-wuppertal.de; Klee, Sonja, E-mail: s.klee@uni-wuppertal.de; Brockmann, Klaus J., E-mail: brockma@uni-wuppertal.de; Benter, Thorsten, E-mail: tbenter@uni-wuppertal.de [Physical and Theoretical Chemistry, Institute for Pure and Applied Mass Spectrometry, University of Wuppertal, 42097 Wuppertal (Germany)] [Physical and Theoretical Chemistry, Institute for Pure and Applied Mass Spectrometry, University of Wuppertal, 42097 Wuppertal (Germany)

    2014-01-15T23:59:59.000Z

    In this study a thermally sampling atmospheric pressure ionization mass spectrometer is described and characterized. The ion transfer stage offers the capability to sample cluster ions at thermal equilibrium and during this transfer fundamental processes possibly affecting the cluster distribution are also readily identified. Additionally, the transfer stage combines optional collision-induced dissociation (CID) analysis of the cluster composition with thermal equilibrium sampling of clusters. The performance of the setup is demonstrated with regard to the proton-bound water cluster system. The benefit of the studied processes is that they can help to improve future transfer stages and to understand cluster ion reactions in ion mobility tubes and high-pressure ion sources. In addition, the instrument allows for the identification of fragmentation and protonation reactions caused by CID.

  9. INFRARED AND ULTRAVIOLET STAR FORMATION IN BRIGHTEST CLUSTER GALAXIES IN THE ACCEPT SAMPLE

    SciTech Connect (OSTI)

    Hoffer, Aaron S.; Donahue, Megan; Hicks, Amalia [Physics and Astronomy Department, Michigan State University, East Lansing, MI 48824-2320 (United States); Barthelemy, R. S., E-mail: hofferaa@msu.edu, E-mail: donahue@pa.msu.edu, E-mail: hicksam@msu.edu, E-mail: ramon.s.barthelemy@wmich.edu [Physics Department, Western Michigan University, Kalamazoo, MI 49008-5252 (United States)

    2012-03-01T23:59:59.000Z

    We present infrared (IR) and ultraviolet (UV) photometry for a sample of brightest cluster galaxies (BCGs). The BCGs are from a heterogeneous but uniformly characterized sample, the Archive of Chandra Cluster Entropy Profile Tables (ACCEPT), of X-ray galaxy clusters from the Chandra X-ray telescope archive with published gas temperature, density, and entropy profiles. We use archival Galaxy Evolution Explorer (GALEX), Spitzer Space Telescope, and Two Micron All Sky Survey (2MASS) observations to assemble spectral energy distributions (SEDs) and colors for BCGs. We find that while the SEDs of some BCGs follow the expectation of red, dust-free old stellar populations, many exhibit signatures of recent star formation in the form of excess UV or mid-IR emission, or both. We establish a mean near-UV (NUV) to 2MASS K color of 6.59 {+-} 0.34 for quiescent BCGs. We use this mean color to quantify the UV excess associated with star formation in the active BCGs. We use both fits to a template of an evolved stellar population and library of starburst models and mid-IR star formation relations to estimate the obscured star formation rates (SFRs). We show that many of the BCGs in X-ray clusters with low central gas entropy exhibit enhanced UV (38%) and mid-IR emission (43%) from 8 to 160 {mu}m, above that expected from an old stellar population. These excesses are consistent with ongoing star formation activity in the BCG, star formation that appears to be enabled by the presence of high-density, X-ray-emitting intergalactic gas in the core of the cluster of galaxies. This hot, X-ray-emitting gas may provide the enhanced ambient pressure and some of the fuel to trigger star formation. This result is consistent with previous works that showed that BCGs in clusters with low central gas entropies host H{alpha} emission-line nebulae and radio sources, while clusters with high central gas entropy exhibit none of these features. GALEX UV and Spitzer mid-IR measurements combined provide a complete picture of unobscured and obscured star formation occurring in these systems. We present IR and UV photometry and estimated equivalent continuous SFRs for a sample of BCGs.

  10. Applying the logic of sample surveys to qualitative case studies: The case cluster method

    E-Print Network [OSTI]

    McClintock, Charles C.; Brannon, Diane; Maynard-Moody, Steven

    1986-03-01T23:59:59.000Z

    Applying the Logic of Sample Suiveys to Qual- itative Case Studies: The Case Cluster Method* Charles C. McClintock, Diane Brannon, and Steven Maynard-Moody ©1979 by ComeU University. 0001 -8392/7^404-0612$00.75 We are grateful to Joe Frances... spe- dal concem vwth int^nai validity, albeit one that employs different the cpiatitative case study. December 1979, volume 24 The differences between case study and sample survey strategies in the analysis of organizations reflect a broader...

  11. Cosmological Implications and Physical Properties of an X-Ray Flux-Limited Sample of Galaxy Clusters

    E-Print Network [OSTI]

    Thomas H. Reiprich

    2003-08-08T23:59:59.000Z

    The original abstract significantly exceeds the space available here, so here's a brief summary. The abstract is similar to the abstract of astro-ph/0111285 (ApJ, 567, 716) which describes the X-ray galaxy cluster sample HIFLUGCS, the X-ray luminosity--gravitational mass relation, the cluster mass function, and the derived cosmological constraints. Additionally, the fraction of the total gravitating mass in the universe which is contained in intracluster gas is quantified. Furthermore, physical properties of the cluster sample have been studied and analyses of relations between different cluster parameters (including the gas mass fraction, gas temperature, X-ray luminosity, gas mass, gravitational mass, beta, and core radius) are discussed. Also, results from an analysis of XMM-Newton performance verification phase data of Abell 1835 are described.

  12. A complete sample of twelve very X-ray luminous galaxy clusters at z>0.5

    E-Print Network [OSTI]

    H. Ebeling; E. Barrett; D. Donovan; C. -J. Ma; A. C. Edge; L. van Speybroeck

    2007-03-15T23:59:59.000Z

    We present the statistically complete and cosmologically most relevant subset of the twelve most distant galaxy clusters detected at z>0.5 by the MAssive Cluster Survey (MACS). Ten of these systems are new discoveries; only two (MACSJ0018.5+1626 aka CL0016+1609, and MACSJ0454.1-0300 aka MS0451.6-0305) were previously known. We provide fundamental cluster properties derived from our optical and X-ray follow-up observations as well as the selection function in tabulated form to facilitate cosmological studies using this sample.

  13. Closing the gap: an X-ray selected sample of clusters of galaxies behind the Galactic plane

    E-Print Network [OSTI]

    Harald Ebeling; Christopher Mullis; Brent Tully

    2000-01-18T23:59:59.000Z

    We discuss the design and current status of the CIZA survey, the first systematic X-ray search for clusters of galaxies in the Galactic plane region. So far, we have compiled a sample of more than 70 X-ray selected clusters at |b|<20 deg, 80% of which were previously unknown. Upon its completion the CIZA cluster catalogue will complement the existing galaxy surveys in the Galactic plane region and allow a fresh look at large-scale structure and local streaming motions.

  14. JOINT ANALYSIS OF CLUSTER OBSERVATIONS. II. CHANDRA/XMM-NEWTON X-RAY AND WEAK LENSING SCALING RELATIONS FOR A SAMPLE OF 50 RICH CLUSTERS OF GALAXIES

    SciTech Connect (OSTI)

    Mahdavi, Andisheh [Department of Physics and Astronomy, San Francisco State University, San Francisco, CA 94131 (United States); Hoekstra, Henk [Leiden Observatory, Leiden University, Niels Bohrweg 2, NL-2333 CA Leiden (Netherlands); Babul, Arif; Bildfell, Chris [Department of Physics and Astronomy, University of Victoria, Victoria, BC V8W 3P6 (Canada); Jeltema, Tesla [Santa Cruz Institute for Particle Physics, UC Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States); Henry, J. Patrick [Institute for Astronomy, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)

    2013-04-20T23:59:59.000Z

    We present a study of multiwavelength X-ray and weak lensing scaling relations for a sample of 50 clusters of galaxies. Our analysis combines Chandra and XMM-Newton data using an energy-dependent cross-calibration. After considering a number of scaling relations, we find that gas mass is the most robust estimator of weak lensing mass, yielding 15% {+-} 6% intrinsic scatter at r{sub 500}{sup WL} (the pseudo-pressure Y{sub X} yields a consistent scatter of 22% {+-} 5%). The scatter does not change when measured within a fixed physical radius of 1 Mpc. Clusters with small brightest cluster galaxy (BCG) to X-ray peak offsets constitute a very regular population whose members have the same gas mass fractions and whose even smaller (<10%) deviations from regularity can be ascribed to line of sight geometrical effects alone. Cool-core clusters, while a somewhat different population, also show the same (<10%) scatter in the gas mass-lensing mass relation. There is a good correlation and a hint of bimodality in the plane defined by BCG offset and central entropy (or central cooling time). The pseudo-pressure Y{sub X} does not discriminate between the more relaxed and less relaxed populations, making it perhaps the more even-handed mass proxy for surveys. Overall, hydrostatic masses underestimate weak lensing masses by 10% on the average at r{sub 500}{sup WL}; but cool-core clusters are consistent with no bias, while non-cool-core clusters have a large and constant 15%-20% bias between r{sub 2500}{sup WL} and r{sub 500}{sup WL}, in agreement with N-body simulations incorporating unthermalized gas. For non-cool-core clusters, the bias correlates well with BCG ellipticity. We also examine centroid shift variance and power ratios to quantify substructure; these quantities do not correlate with residuals in the scaling relations. Individual clusters have for the most part forgotten the source of their departures from self-similarity.

  15. The Spatial Clustering of ROSAT All-Sky Survey AGNs III. Expanded Sample and Comparison with Optical AGNs

    E-Print Network [OSTI]

    Krumpe, Mirko; Coil, Alison L; Aceves, Hector

    2011-01-01T23:59:59.000Z

    This is the third paper in a series that reports on our investigation of the clustering properties of AGNs identified in the ROSAT All-Sky Survey (RASS) and Sloan Digital Sky Survey (SDSS). In this paper, we extend the redshift range to 0.07clustering amplitudes of both X-ray and optically-selected SDSS broad-line AGNs with and without radio detections as well as for X-ray selected narrow-line RASS/SDSS AGNs. We measure the clustering amplitude through cross-correlation functions (CCFs) with SDSS galaxies and derive the bias by applying a halo occupation distribution (HOD) model directly to the CCFs. We find no statistically convincing difference in the clustering of X-ray and optically-selected broad-line AGNs, as well as with samples in which radio-detected AGNs are excluded. This is in contrast to low redshift optically-selected narrow-line AGNs, where radio-loud AGNs are found in more massive halos than optical AGNs without a radio-detection. The typical dark matter halo mass...

  16. Temperature profiles of a representative sample of nearby X-ray galaxy clusters

    E-Print Network [OSTI]

    G. W. Pratt; H. Boehringer; J. H. Croston; M. Arnaud; S. Borgani; A. Finoguenov; R. F. Temple

    2006-09-18T23:59:59.000Z

    A study of the structural and scaling properties of the temperature distribution of the hot, X-ray emitting intra-cluster medium of galaxy clusters, and its dependence on dynamical state, can give insights into the physical processes governing the formation and evolution of structure. We analyse the X-ray temperature profiles from XMM-Newton observations of 15 nearby (z temperature range from 2.5 keV to 8.5 keV, and present a variety of X-ray morphologies. We derive accurate projected temperature profiles to ~ 0.5 R_200, and compare structural properties (outer slope, presence of cooling core) with a quantitative measure of the X-ray morphology as expressed by power ratios. We also compare the results to recent cosmological numerical simulations. Once the temperature profiles are scaled by an average cluster temperature (excluding the central region) and the estimated virial radius, the profiles generally decline in the region 0.1 R_200 temperature decrement appear to be slightly more regular. The present results lend further evidence to indicate that clusters are a regular population, at least outside the core region.

  17. Respondent-driven sampling bias induced by clustering and community structure in social networks

    E-Print Network [OSTI]

    Rocha, Luis Enrique Correa; Lambiotte, Renaud; Liljeros, Fredrik

    2015-01-01T23:59:59.000Z

    Sampling hidden populations is particularly challenging using standard sampling methods mainly because of the lack of a sampling frame. Respondent-driven sampling (RDS) is an alternative methodology that exploits the social contacts between peers to reach and weight individuals in these hard-to-reach populations. It is a snowball sampling procedure where the weight of the respondents is adjusted for the likelihood of being sampled due to differences in the number of contacts. In RDS, the structure of the social contacts thus defines the sampling process and affects its coverage, for instance by constraining the sampling within a sub-region of the network. In this paper we study the bias induced by network structures such as social triangles, community structure, and heterogeneities in the number of contacts, in the recruitment trees and in the RDS estimator. We simulate different scenarios of network structures and response-rates to study the potential biases one may expect in real settings. We find that the ...

  18. Small-sample brain mapping: sparse recovery on spatially correlated designs with randomization and clustering

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Small-sample brain mapping: sparse recovery on spatially correlated designs with randomization Abstract Functional neuroimaging can measure the brain's response to an external stimulus. It is used to perform brain mapping: identifying from these observations the brain regions in- volved. This problem can

  19. THE BARYONIC ACOUSTIC FEATURE AND LARGE-SCALE CLUSTERING IN THE SLOAN DIGITAL SKY SURVEY LUMINOUS RED GALAXY SAMPLE

    SciTech Connect (OSTI)

    Kazin, Eyal A.; Blanton, Michael R.; Scoccimarro, Roman [Center for Cosmology and Particle Physics, New York University, 4 Washington Place, New York, NY 10003 (United States); McBride, Cameron K.; Berlind, Andreas A. [Department of Physics and Astronomy, Vanderbilt University, 1807 Station B, Nashville, TN 37235 (United States); Bahcall, Neta A. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Brinkmann, Jon [Apache Point Observatory, P.O. Box 59, Sunspot, NM 88349 (United States); Czarapata, Paul [Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States); Frieman, Joshua A. [Particle Astrophysics Center, Fermilab, P.O. Box 500, Batavia, IL 60510 (United States); Kent, Stephen M. [MS 127, Fermilab, P.O. Box 500, Batavia, IL 60510 (United States); Schneider, Donald P. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States); Szalay, Alexander S., E-mail: eyalkazin@gmail.co [Department of Physics and Astronomy, The Johns Hopkins University, 3701 San Martin Drive, Baltimore, MD 21218 (United States)

    2010-02-20T23:59:59.000Z

    We examine the correlation function xi of the Sloan Digital Sky Survey Luminous Red Galaxy sample at large scales (60 h {sup -1} Mpc < s < 400 h {sup -1} Mpc) using the final data release (DR7). Focusing on a quasi-volume-limited (0.16 < z < 0.36) subsample and utilizing mock galaxy catalogs, we demonstrate that the observed baryonic acoustic peak and larger scale signal are consistent with LAMBDACDM at 70%-95% confidence. Fitting data to a non-linear, redshift-space, template-based model, we constrain the peak position at s{sub p} = 101.7+- 3.0 h {sup -1} Mpc when fitting the range 60 h {sup -1} Mpc < s < 150 h {sup -1} Mpc (1sigma uncertainties). This redshift-space distance s{sub p} is related to the comoving sound horizon scale r{sub s} after taking into account matter-clustering non-linearities, redshift distortions, and galaxy-clustering bias. Mock catalogs show that the probability that a DR7-sized sample would not have an identifiable peak is at least {approx}10%. As a consistency check of a fiducial cosmology, we use the observed s{sub p} to obtain the distance D{sub V}{identical_to}((1+z){sup 2}D{sup 2}{sub A}cz/H(z)){sup 1/3} relative to the acoustic scale. We find r{sub s} /D{sub V} (z = 0.278) = 0.1389 +- 0.0043. This result is in excellent agreement with Percival et al., who examine roughly the same data set, but use the power spectrum. Comparison with other determinations in the literature are also in very good agreement. The signal of the full sample at 125 h {sup -1} Mpc < s < 200 h {sup -1} Mpc tends to be high relative to theoretical expectations; this slight deviation can probably be attributed to sample variance. We have tested our results against a battery of possible systematic effects, finding all effects are smaller than our estimated sample variance.

  20. THE ATACAMA COSMOLOGY TELESCOPE: DYNAMICAL MASSES AND SCALING RELATIONS FOR A SAMPLE OF MASSIVE SUNYAEV-ZEL'DOVICH EFFECT SELECTED GALAXY CLUSTERS {sup ,}

    SciTech Connect (OSTI)

    Sifon, Cristobal; Barrientos, L. Felipe; Gonzalez, Jorge; Infante, Leopoldo; Duenner, Rolando [Departamento de Astronomia y Astrofisica, Facultad de Fisica, Pontificia Universidad Catolica de Chile, Casilla 306, Santiago 22 (Chile); Menanteau, Felipe; Hughes, John P.; Baker, Andrew J. [Department of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Hasselfield, Matthew [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada); Marriage, Tobias A.; Crichton, Devin; Gralla, Megan B. [Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, MD 21218-2686 (United States); Addison, Graeme E.; Dunkley, Joanna [Sub-department of Astrophysics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Battaglia, Nick; Bond, J. Richard; Hajian, Amir [Canadian Institute for Theoretical Astrophysics, University of Toronto, Toronto, ON M5S 3H8 (Canada); Das, Sudeep [Berkeley Center for Cosmological Physics, LBL and Department of Physics, University of California, Berkeley, CA 94720 (United States); Devlin, Mark J. [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104 (United States); Hilton, Matt [School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD (United Kingdom); and others

    2013-07-20T23:59:59.000Z

    We present the first dynamical mass estimates and scaling relations for a sample of Sunyaev-Zel'dovich effect (SZE) selected galaxy clusters. The sample consists of 16 massive clusters detected with the Atacama Cosmology Telescope (ACT) over a 455 deg{sup 2} area of the southern sky. Deep multi-object spectroscopic observations were taken to secure intermediate-resolution (R {approx} 700-800) spectra and redshifts for Almost-Equal-To 60 member galaxies on average per cluster. The dynamical masses M{sub 200c} of the clusters have been calculated using simulation-based scaling relations between velocity dispersion and mass. The sample has a median redshift z = 0.50 and a median mass M{sub 200c}{approx_equal}12 Multiplication-Sign 10{sup 14} h{sub 70}{sup -1} M{sub sun} with a lower limit M{sub 200c}{approx_equal}6 Multiplication-Sign 10{sup 14} h{sub 70}{sup -1} M{sub sun}, consistent with the expectations for the ACT southern sky survey. These masses are compared to the ACT SZE properties of the sample, specifically, the match-filtered central SZE amplitude y{sub 0}-tilde, the central Compton parameter y{sub 0}, and the integrated Compton signal Y{sub 200c}, which we use to derive SZE-mass scaling relations. All SZE estimators correlate with dynamical mass with low intrinsic scatter ({approx}< 20%), in agreement with numerical simulations. We explore the effects of various systematic effects on these scaling relations, including the correlation between observables and the influence of dynamically disturbed clusters. Using the three-dimensional information available, we divide the sample into relaxed and disturbed clusters and find that {approx}50% of the clusters are disturbed. There are hints that disturbed systems might bias the scaling relations, but given the current sample sizes, these differences are not significant; further studies including more clusters are required to assess the impact of these clusters on the scaling relations.

  1. THE SPATIAL CLUSTERING OF ROSAT ALL-SKY SURVEY ACTIVE GALACTIC NUCLEI. III. EXPANDED SAMPLE AND COMPARISON WITH OPTICAL ACTIVE GALACTIC NUCLEI

    SciTech Connect (OSTI)

    Krumpe, Mirko; Coil, Alison L. [University of California, San Diego, Center for Astrophysics and Space Sciences, 9500 Gilman Drive, La Jolla, CA 92093-0424 (United States); Miyaji, Takamitsu; Aceves, Hector, E-mail: mkrumpe@ucsd.edu [IAUNAM-E (Instituto de Astronomia de la Universidad Nacional Autonoma de Mexico, Ensenada), P.O. Box 439027, San Diego, CA 92143-9027 (United States)

    2012-02-10T23:59:59.000Z

    This is the third paper in a series that reports on our investigation of the clustering properties of active galactic nuclei (AGNs) identified in the ROSAT All-Sky Survey (RASS) and the Sloan Digital Sky Survey (SDSS). In this paper, we extend the redshift range to 0.07 < z < 0.50 and measure the clustering amplitudes of both X-ray-selected and optically selected SDSS broad-line AGNs with and without radio detections as well as for X-ray-selected narrow-line RASS/SDSS AGNs. We measure the clustering amplitude through cross-correlation functions (CCFs) with SDSS galaxies and derive the bias by applying a halo occupation distribution model directly to the CCFs. We find no statistically convincing difference in the clustering of X-ray-selected and optically selected broad-line AGNs, as well as with samples in which radio-detected AGNs are excluded. This is in contrast to low-redshift optically selected narrow-line AGNs, where radio-loud AGNs are found in more massive halos than optical AGNs without a radio detection. The typical dark matter halo masses of our broad-line AGNs are log (M{sub DMH}/[h{sup -1} M{sub Sun }]) {approx} 12.4-13.4, consistent with the halo mass range of typical non-AGN galaxies at low redshifts. We find no significant difference between the clustering of X-ray-selected narrow-line AGNs and broad-line AGNs. We confirm the weak dependence of the clustering strength on AGN X-ray luminosity at a {approx}2{sigma} level. Finally, we summarize the current picture of AGN clustering to z {approx} 1.5 based on three-dimensional clustering measurements.

  2. The SEGUE Stellar Parameter Pipeline. IV. Validation with an Extended Sample of Galactic Globular and Open Clusters

    SciTech Connect (OSTI)

    Smolinski, Jason P.; Beers, Timothy C.; Lee, Young Sun; /Michigan State U. /Michigan State U., JINA; An, Deokkeun; /Ewha Women's U., Seoul; Bickerton, Steven J.; /Princeton U., Astrophys. Sci. Dept.; Johnson, Jennifer A.; /Ohio State U., Dept. Astron.; Loomis, Craig P.; /Princeton U., Astrophys. Sci. Dept.; Rockosi, Constance M.; /Lick Observ.; Sivarani, Thirupathi; /Bangalore, Indian Inst. Astrophys.; Yanny, Brian; /Fermilab

    2010-08-01T23:59:59.000Z

    Spectroscopic and photometric data for likely member stars of five Galactic globular clusters (M 3, M 53, M 71, M 92, and NGC 5053) and three open clusters (M 35, NGC 2158, and NGC 6791) are processed by the current version of the SEGUE Stellar Parameter Pipeline (SSPP), in order to determine estimates of metallicities and radial velocities for the clusters. These results are then compared to values from the literature. We find that the mean metallicity (<[Fe/H]>) and mean radial velocity (hRVi) estimates for each cluster are almost all within 2{sigma} of the adopted literature values; most are within 1{sigma}. We also demonstrate that the new version of the SSPP achieves small, but noteworthy, improvements in <[Fe/H]> estimates at the extrema of the cluster metallicity range, as compared to a previous version of the pipeline software. These results provide additional confidence in the application of the SSPP for studies of the abundances and kinematics of stellar populations in the Galaxy.

  3. THE SEGUE STELLAR PARAMETER PIPELINE. IV. VALIDATION WITH AN EXTENDED SAMPLE OF GALACTIC GLOBULAR AND OPEN CLUSTERS

    SciTech Connect (OSTI)

    Smolinski, Jason P.; Lee, Young Sun; Beers, Timothy C. [Department of Physics and Astronomy and JINA (Joint Institute for Nuclear Astrophysics), Michigan State University, East Lansing, MI 48824 (United States); An, Deokkeun [Department of Science Education, Ewha Womans University, Seoul 120-750 (Korea, Republic of); Bickerton, Steven J.; Loomis, Craig P. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Johnson, Jennifer A. [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Rockosi, Constance M. [UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States); Sivarani, Thirupathi [IIAP: Indian Institute of Astrophysics, II Block, Koramangala, Bangalore 560 034 (India); Yanny, Brian, E-mail: smolin19@msu.edu, E-mail: lee@pa.msu.edu, E-mail: beers@pa.msu.edu, E-mail: deokkeun@ewha.ac.kr, E-mail: bick@astro.princeton.edu, E-mail: cloomis@astro.princeton.edu, E-mail: jaj@astronomy.ohio-state.edu, E-mail: crockosi@ucolick.org, E-mail: sivarani@iiap.res.in, E-mail: yanny@fnal.gov [Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States)

    2011-03-15T23:59:59.000Z

    Spectroscopic and photometric data for likely member stars of five Galactic globular clusters (M3, M53, M71, M92, and NGC 5053) and three open clusters (M35, NGC 2158, and NGC 6791) are processed by the current version of the SEGUE Stellar Parameter Pipeline (SSPP), in order to determine estimates of metallicities and radial velocities (RVs) for the clusters. These results are then compared to values from the literature. We find that the mean metallicity (([Fe/H])) and mean radial velocity ((RV)) estimates for each cluster are almost all within 2{sigma} of the adopted literature values; most are within 1{sigma}. We also demonstrate that the new version of the SSPP achieves small, but noteworthy, improvements in ([Fe/H]) estimates at the extrema of the cluster metallicity range, as compared to a previous version of the pipeline software. These results provide additional confidence in the application of the SSPP for studies of the abundances and kinematics of stellar populations in the Galaxy.

  4. A New Method For Robust High-Precision Time-Series Photometry From Well-Sampled Images: Application to Archival MMT/Megacam Observations of the Open Cluster M37

    E-Print Network [OSTI]

    Chang, S -W; Hartman, J D

    2015-01-01T23:59:59.000Z

    We introduce new methods for robust high-precision photometry from well-sampled images of a non-crowded field with a strongly varying point-spread function. For this work, we used archival imaging data of the open cluster M37 taken by MMT 6.5m telescope. We find that the archival light curves from the original image subtraction procedure exhibit many unusual outliers, and more than 20% of data get rejected by the simple filtering algorithm adopted by early analysis. In order to achieve better photometric precisions and also to utilize all available data, the entire imaging database was re-analyzed with our time-series photometry technique (Multi-aperture Indexing Photometry) and a set of sophisticated calibration procedures. The merit of this approach is as follows: we find an optimal aperture for each star with a maximum signal-to-noise ratio, and also treat peculiar situations where photometry returns misleading information with more optimal photometric index. We also adopt photometric de-trending based on ...

  5. Confirming EIS Clusters. Optical and Infrared Imaging

    E-Print Network [OSTI]

    L. F. Olsen; H. E. Jorgensen; M. Scodeggio; L. da Costa; R. Rengelink; M. Nonino; A. Biviano; M. Ramella; W. Boschin

    1999-10-25T23:59:59.000Z

    Clusters of galaxies are important targets in observationally cosmology, as they can be used both to study the evolution of the galaxies themselves and to constrain cosmological parameters. Here we report on the first results of a major effort to build up a sample of distant galaxy clusters to form the basis for further studies within those fields. We search for simultaneous overdensities in color and space to obtain supporting evidence for the reality of the clusters. We find a confirmation rate for EIS clusters of 66%, suggesting that a total of about 80 clusters with z>=0.6 are within reach using the EIS cluster candidates.

  6. Cluster Selection and the Evolution of Brightest Cluster Galaxies

    E-Print Network [OSTI]

    D. J. Burke; C. A. Collins; R. G. Mann

    2000-02-08T23:59:59.000Z

    The K-band Hubble diagram of Brightest Cluster Galaxies (BCGs) is presented for a large, X-ray selected cluster sample extending out to z = 0.8. The controversy over the degree of BCG evolution is shown to be due to sample selection, since the BCG luminosity depends upon the cluster environment. Selecting only the most X-ray luminous clusters produces a BCG sample which shows, under the assumption of an Einstein-de Sitter cosmology, significantly less mass growth than that predicted by current semi-analytic galaxy formation models, and significant evidence of any growth only if the dominant stellar population of the BCGs formed relatively recently (z <= 2.6).

  7. A GMBCG galaxy cluster catalog of 55,880 rich clusters from SDSS DR7

    SciTech Connect (OSTI)

    Hao, Jiangang; McKay, Timothy A.; Koester, Benjamin P.; Rykoff, Eli S.; Rozo, Eduardo; Annis, James; Wechsler, Risa H.; Evrard, August; Siegel, Seth R.; Becker, Matthew; Busha, Michael; /Fermilab /Michigan U. /Chicago U., Astron. Astrophys. Ctr. /UC, Santa Barbara /KICP, Chicago /KIPAC, Menlo Park /SLAC /Caltech /Brookhaven

    2010-08-01T23:59:59.000Z

    We present a large catalog of optically selected galaxy clusters from the application of a new Gaussian Mixture Brightest Cluster Galaxy (GMBCG) algorithm to SDSS Data Release 7 data. The algorithm detects clusters by identifying the red sequence plus Brightest Cluster Galaxy (BCG) feature, which is unique for galaxy clusters and does not exist among field galaxies. Red sequence clustering in color space is detected using an Error Corrected Gaussian Mixture Model. We run GMBCG on 8240 square degrees of photometric data from SDSS DR7 to assemble the largest ever optical galaxy cluster catalog, consisting of over 55,000 rich clusters across the redshift range from 0.1 < z < 0.55. We present Monte Carlo tests of completeness and purity and perform cross-matching with X-ray clusters and with the maxBCG sample at low redshift. These tests indicate high completeness and purity across the full redshift range for clusters with 15 or more members.

  8. A GMBCG Galaxy Cluster Catalog of 55,424 Rich Clusters from SDSS DR7

    SciTech Connect (OSTI)

    Hao, Jiangang; /Fermilab; McKay, Timothy A.; /Michigan U.; Koester, Benjamin P.; /Chicago U.; Rykoff, Eli S.; /UC, Santa Barbara /LBL, Berkeley; Rozo, Eduardo; /Chicago U.; Annis, James; /Fermilab; Wechsler, Risa H.; /SLAC; Evrard, August; /Michigan U.; Siegel, Seth R.; /Michigan U.; Becker, Matthew; /Chicago U.; Busha, Michael; /SLAC; Gerdes, David; /Michigan U.; Johnston, David E.; /Fermilab; Sheldon, Erin; /Brookhaven

    2011-08-22T23:59:59.000Z

    We present a large catalog of optically selected galaxy clusters from the application of a new Gaussian Mixture Brightest Cluster Galaxy (GMBCG) algorithm to SDSS Data Release 7 data. The algorithm detects clusters by identifying the red sequence plus Brightest Cluster Galaxy (BCG) feature, which is unique for galaxy clusters and does not exist among field galaxies. Red sequence clustering in color space is detected using an Error Corrected Gaussian Mixture Model. We run GMBCG on 8240 square degrees of photometric data from SDSS DR7 to assemble the largest ever optical galaxy cluster catalog, consisting of over 55,000 rich clusters across the redshift range from 0.1 < z < 0.55. We present Monte Carlo tests of completeness and purity and perform cross-matching with X-ray clusters and with the maxBCG sample at low redshift. These tests indicate high completeness and purity across the full redshift range for clusters with 15 or more members.

  9. Radio Bubbles in Clusters

    E-Print Network [OSTI]

    R. J. H. Dunn; A. C. Fabian; G. B. Taylor

    2005-10-06T23:59:59.000Z

    We extend our earlier work on cluster cores with distinct radio bubbles, adding more active bubbles, i.e. those with Ghz radio emission, to our sample, and also investigating ``ghost bubbles,'' i.e. those without GHz radio emission. We have determined k, which is the ratio of the total particle energy to that of the electrons radiating between 10 MHz and 10 GHz. Constraints on the ages of the active bubbles confirm that the ratio of the energy factor, k, to the volume filling factor, f lies within the range 1 < k/f < 1000. In the assumption that there is pressure equilibrium between the radio-emitting plasma and the surrounding thermal X-ray gas, none of the radio lobes has equipartition between the relativistic particles and the magnetic field. A Monte-Carlo simulation of the data led to the conclusion that there are not enough bubbles present in the current sample to be able to determine the shape of the population. An analysis of the ghost bubbles in our sample showed that on the whole they have higher upper limits on k/f than the active bubbles, especially when compared to those in the same cluster. A study of the Brightest 55 cluster sample shows that 17, possibly 20, clusters required some form of heating as they have a short central cooling time, t_cool < 3 Gyr, and a large central temperature drop, T_centre/T_outer< 1/2. Of these between 12 (70 per cent) and 15 (75 per cent), contain bubbles. This indicates that the duty cycle of bubbles is large in such clusters and that they can play a major role in the heating process.

  10. The fundamental plane of clusters of galaxies: a quest for understanding cluster dynamics and morphology

    E-Print Network [OSTI]

    Christoph Fritsch; Thomas Buchert

    1999-03-10T23:59:59.000Z

    We discuss implications of the fundamental plane parameters of clusters of galaxies derived from combined optical and X-ray data of a sample of 78 nearby clusters. In particular, we investigate the dependence of these parameters on the dynamical state of the cluster. We introduce a new concept of allocation of the fundamental plane of clusters derived from their intrinsic morphological properties, and put some theoretical implications of the existence of a fundamental plane into perspective.

  11. CLUSTER CHEMISTRY

    E-Print Network [OSTI]

    Muetterties, Earl L.

    2013-01-01T23:59:59.000Z

    Advanced Inorganic Chemistry, 11 Wiley Huetterties and C. M.Submitted to the Journal of Organometallic ChemistryCLUSTER CHEMISTRY Earl L. Muetterties TWO-WEEK LOAN COPY May

  12. Young massive star clusters in nearby galaxies. I. Identification and general properties of cluster systems

    E-Print Network [OSTI]

    Soeren S. Larsen; Tom Richtler

    1999-02-19T23:59:59.000Z

    Using ground-based UBVRI+Halpha CCD photometry we have been carrying out a search for young massive star clusters (YMCs) in a sample consisting of 21 nearby spiral galaxies. We find a large variety concerning the richness of the cluster systems, with some galaxies containing no YMCs at all and others hosting very large numbers of YMCs. Examples of galaxies with poor cluster systems are NGC 300 and NGC 4395, while the richest cluster systems are found in the galaxies NGC 5236, NGC 2997 and NGC 1313. The age distributions of clusters in these galaxies show no obvious peaks, indicating that massive star clusters are formed as an ongoing process rather than in bursts. This is in contrast to what is observed in starbursts and merger galaxies. The radial distributions of clusters follow the Halpha surface brightness. For the galaxies in our sample there is no correlation between the morphological type and the presence of YMCs

  13. The APM/Matched-Filter Cluster Catalog

    E-Print Network [OSTI]

    Wataru Kawasaki

    1999-12-15T23:59:59.000Z

    A catalog of nearby clusters in the 5800 deg$^2$ area in the southern Galactic cap is constructed by applying a matched-filter cluster-finding algorithm to the sample of 3.3 million galaxies from the APM Galaxy Survey. I have preliminarily detected more than 4000 cluster candidates with estimated redshift of less than 0.2 and with richness similar to those of ACO clusters. Generally, a good correspondence is found between the nearest cluster candidates in our catalog and the ACO clusters which have measured redshift. While the ACO catalog becomes incomplete at z>0.08, the completeness limit of our cluster catalog reaches z=0.15.

  14. Clustering: Applications

    E-Print Network [OSTI]

    Sharir, Micha

    Data Compression K Image Processing Center for Geometric Computing Motivation Geometric Clustering = function of frequency of word w i in ff: K What is the distance between two documents ff and fi? ffl d (shell) problem. K Cylinder fitting Center for Geometric Computing Statistical Estimators Geometric

  15. Scale Height Evolution of Star Clusters

    E-Print Network [OSTI]

    Froebrich, Dirk

    0) Introduction 1) The FSR Cluster Sample 2) Photometric Decontamination 3) Old Clusters 4) Distance/Background decontamination adaptation of the (Bonatto & Bica 2007) decontamination procedure #12;Fore/Background decontamination adaptation of the (Bonatto & Bica 2007) decontamination procedure calculate CCM distance between

  16. The 160 Square Degree ROSAT Survey - Revised Catalog & Cluster Evolution

    E-Print Network [OSTI]

    Mullis, C; Quintana, H; Vikhlinin, A; Henry, P; Gioia, I; Hornstrup, A; Forman, W; Jones, C; Mullis, Christopher; Namara, Brian Mc; Quintana, Hernan; Vikhlinin, Alexey; Henry, Patrick; Gioia, Isabella; Hornstrup, Allan; Forman, William; Jones, Christine

    2003-01-01T23:59:59.000Z

    We have constructed a large, statistically complete sample of galaxy clusters serendipitously detected as extended X-ray sources in 647 ROSAT PSPC pointed observations. The survey covers 158 square degrees with a median sample flux limit of 1.2 x 10^-13 erg cm^-2 s^-1 (0.5-2.0 keV). Our sample consists of 201 clusters of galaxies characterized by a median redshift of z=0.25 and a maximum of z=1.26. With 22 clusters at z > 0.5, the 160 Square Degree ROSAT Survey is the largest high-redshift sample of X-ray-selected clusters published to date. Here we describe the revised sample which features spectroscopic redshifts for 99.5% of the clusters and discuss the implications for evolution in the cluster abundance.

  17. Experimental Comparison of Cluster Ensemble L.I. Kuncheva

    E-Print Network [OSTI]

    Kuncheva, Ludmila I.

    ). The best ensembles were based on k-means individual clusterers. Consensus functions interpreting clusterers were created using the same clustering method, in one of the following ways: (a) k-means with random initialisations (b) k-means with random initialisations and using random sub-samples of the da

  18. The BMW X-ray Cluster Survey

    E-Print Network [OSTI]

    Alberto Moretti; Luigi Guzzo; Sergio Campana; Stefano Covino; Davide Lazzati; Marcella Longhetti; Emilio Molinari; Maria Rosa Panzera; Gianpiero Tagliaferri; Ian Dell'Antonio

    2001-03-21T23:59:59.000Z

    We describe the main features of the BMW survey of serendipitous X-ray clusters, based on the still unexploited ROSAT-HRI archival observations. The sky coverage, surface density and first deep optical CCD images of the candidates indicate that this sample can represent an excellent complement to the existing PSPC deep cluster surveys and will provide us with a fully independent probe of the evolution of the cluster abundance, in addition to significantly increasing the number of clusters known at z>0.6.

  19. The BMW X-ray Cluster Survey

    E-Print Network [OSTI]

    Moretti, A; Campana, S; Covino, S; Lazzati, D; Longhetti, M; Molinari, E; Panzera, M R; Tagliaferri, G; Dell'Antonio, I P; Moretti, Alberto; Guzzo, Luigi; Campana, Sergio; Covino, Stefano; Lazzati, Davide; Longhetti, Marcella; Molinari, Emilio; Panzera, Maria Rosa; Tagliaferri, Gianpiero; Antonio, Ian Dell'

    2001-01-01T23:59:59.000Z

    We describe the main features of the BMW survey of serendipitous X-ray clusters, based on the still unexploited ROSAT-HRI archival observations. The sky coverage, surface density and first deep optical CCD images of the candidates indicate that this sample can represent an excellent complement to the existing PSPC deep cluster surveys and will provide us with a fully independent probe of the evolution of the cluster abundance, in addition to significantly increasing the number of clusters known at z>0.6.

  20. THE MASSIVE DISTANT CLUSTERS OF WISE SURVEY: THE FIRST DISTANT GALAXY CLUSTER DISCOVERED BY WISE

    SciTech Connect (OSTI)

    Gettings, Daniel P.; Gonzalez, Anthony H.; Mancone, Conor [Department of Astronomy, University of Florida, 211 Bryant Space Center, Gainesville, FL 32611 (United States); Stanford, S. Adam [Institute of Geophysics and Planetary Physics, Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Eisenhardt, Peter R. M.; Stern, Daniel [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Brodwin, Mark [Department of Physics and Astronomy, University of Missouri, 5110 Rockhill Road, Kansas City, MO 64110 (United States); Zeimann, Gregory R. [Department of Physics, University of California, One Shields Avenue, Davis, CA 95616 (United States); Masci, Frank J. [Infrared Processing and Analysis Center, California Institute of Technology 100-22, Pasadena, CA 91125 (United States); Papovich, Casey [George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, and Department of Physics and Astronomy, Texas A and M University, College Station, TX, 77843-4242 (United States); Tanaka, Ichi [Subaru Telescope, National Astronomical Observatory of Japan, 650 North A'ohoku Place, Hilo, HI 96720 (United States); Wright, Edward L. [UCLA Astronomy, P.O. Box 951547, Los Angeles, CA 90095-1547 (United States)

    2012-11-01T23:59:59.000Z

    We present spectroscopic confirmation of a z = 0.99 galaxy cluster discovered using data from the Wide-field Infrared Survey Explorer (WISE). This is the first z {approx} 1 cluster candidate from the Massive Distant Clusters of WISE Survey to be confirmed. It was selected as an overdensity of probable z {approx}> 1 sources using a combination of WISE and Sloan Digital Sky Survey DR8 photometric catalogs. Deeper follow-up imaging data from Subaru and WIYN reveal the cluster to be a rich system of galaxies, and multi-object spectroscopic observations from Keck confirm five cluster members at z = 0.99. The detection and confirmation of this cluster represents a first step toward constructing a uniformly selected sample of distant, high-mass galaxy clusters over the full extragalactic sky using WISE data.

  1. Cosmography with cluster strong lensing

    E-Print Network [OSTI]

    James Gilmore; Priyamvada Natarajan

    2009-05-29T23:59:59.000Z

    By stacking an ensemble of strong lensing clusters, we demonstrate the feasibility of placing constraints on the dark energy equation of state. This is achieved by using multiple images of sources at two or more distinct redshift planes. The sample of smooth clusters in our simulations is based on observations of massive clusters and the distribution of background galaxies is constructed using the Hubble Deep Field. Our source distribution reproduces the observed redshift distribution of multiply imaged sources in Abell 1689. The cosmology recovery depends on the number of image families with known spectroscopic redshifts and the number of stacked clusters. Our simulations suggest that constraints comparable to those derived from other competing established techniques on a constant dark energy equation of state can be obtained using 10 to 40 clusters with 5 or more families of multiple images. We have also studied the observational errors in the image redshifts and positions. We find that spectroscopic redshifts and high resolution {\\it Hubble Space Telescope} images are required to eliminate confidence contour relaxation relative to the ideal case in our simulations. This suggests that the dark energy equation of state, and other cosmological parameters, can be constrained with existing {\\it Hubble Space Telescope} images of lensing clusters coupled with dedicated ground-based arc spectroscopy.

  2. Sampling box

    DOE Patents [OSTI]

    Phillips, Terrance D. (617 Chestnut Ct., Aiken, SC 29803); Johnson, Craig (100 Midland Rd., Oak Ridge, TN 37831-0895)

    2000-01-01T23:59:59.000Z

    An air sampling box that uses a slidable filter tray and a removable filter cartridge to allow for the easy replacement of a filter which catches radioactive particles is disclosed.

  3. Cluster Statistics

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisiting the TWPSuccessAlamosCharacterization2Climate, Ocean and SeaClotClusterHopper

  4. Technique for fast and efficient hierarchical clustering

    DOE Patents [OSTI]

    Stork, Christopher

    2013-10-08T23:59:59.000Z

    A fast and efficient technique for hierarchical clustering of samples in a dataset includes compressing the dataset to reduce a number of variables within each of the samples of the dataset. A nearest neighbor matrix is generated to identify nearest neighbor pairs between the samples based on differences between the variables of the samples. The samples are arranged into a hierarchy that groups the samples based on the nearest neighbor matrix. The hierarchy is rendered to a display to graphically illustrate similarities or differences between the samples.

  5. Statistical fractal analysis of 25 young star clusters

    E-Print Network [OSTI]

    Gregorio-Hetem, J; Santos-Silva, T; Fernandes, B

    2015-01-01T23:59:59.000Z

    A large sample of young stellar groups is analysed aiming to investigate their clustering properties and dynamical evolution. A comparison of the Q statistical parameter, measured for the clusters, with the fractal dimension estimated for the projected clouds shows that 52% of the sample has substructures and tends to follow the theoretically expected relation between clusters and clouds, according to calculations for artificial distribution of points. The fractal statistics was also compared to structural parameters revealing that clusters having radial density profile show a trend of parameter s increasing with mean surface stellar density. The core radius of the sample, as a function of age, follows a distribution similar to that observed in stellar groups of Milky Way and other galaxies. They also have dynamical age, indicated by their crossing time that is similar to unbound associations. The statistical analysis allowed us to separate the sample into two groups showing different clustering characteristi...

  6. Literature Review on Spectral Clustering

    E-Print Network [OSTI]

    Chen, Mengna

    2013-01-01T23:59:59.000Z

    Guan & Kulis. Kernel k-means, Spectral Clustering andspectral clustering and k-means clustering and spectralRelationship with kernel K-means algorithm …………………………………………

  7. Wide Field CCD photometry around nine open clusters

    E-Print Network [OSTI]

    S. Sharma; A. K. Pandey; K. Ogura; H. Mito; K. Tarusava; R. Sagar

    2006-07-24T23:59:59.000Z

    In this paper we study the evolution of core and corona of nine open clusters using the projected radial density profiles derived from homogeneous CCD photometric data obtained through the 105-cm Kiso Schmidt telescope. The age and galactocentric distance of the target clusters varies from 16 Myr to 2000 Myr and 9 kpcto 10.8 kpc respectively. Barring Be 62, which is young open cluster, other clusters show a uniform reddening across the cluster region. The reddening in Be 62varies from $E(B-V)_{min}$= 0.70 mag to $E(B-V)_{max}$= 1.00 mag. The corona of six of the clusters in the present sample is found to be elongated, however on the basis of the present sample it is not possible to establish any correlation between the age and shape of the core. The elongated core in the case of young cluster Be 62 may reflect the initial conditions in the parental molecular cloud. The other results of the present study are (i) Core radius `$r_c$' and corona size $`r_{cn}$'/cluster radius $`r_{cl}$' are linearly correlated. (ii) The $r_c/r_{cn}/r_{cl}$ are linearly correlated with the number of stars in that region. (iii) In the age range 10-1000 Myr, the core and corona shrink with age. (iv) We find that in the galactocentric distance range 9 - 10 kpc, the core and corona/cluster extent of the clusters increase with the galactocentric distance.

  8. The Alignment effect of brightest cluster galaxies in the SDSS

    SciTech Connect (OSTI)

    Kim, R. S. J. [Princeton Univ., Princeton, NJ (United States); Annis, J. [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Strauss, M. A. [Princeton Univ., Princeton, NJ (United States); Lupton, R. H. [Princeton Univ., Princeton, NJ (United States); Bahcall, N. A. [Princeton Univ., Princeton, NJ (United States); Gunn, J. E. [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States); Kepner, J. V. [MIT Lincoln Laboratory, Lexington, MA (United States); Postman, M. [Space Telescope Science Institute, Baltimore, MD (United States)

    2001-10-01T23:59:59.000Z

    One of the most vital observational clues for unraveling the origin of Brightest Cluster Galaxies (BCG) is the observed alignment of the BCGs with their host cluster and its surroundings. We have examined the BCG-cluster alignment effect, using clusters of galaxies detected from the Sloan Digital Sky Survey (SDSS). We find that the BCGs are preferentially aligned with the principal axis of their hosts, to a much higher redshift (z >~ 0.3) than probed by previous studies (z <~ 0.1). The alignment effect strongly depends on the magnitude difference of the BCG and the second and third brightest cluster members: we find a strong alignment effect for the dominant BCGs, while less dominant BCGs do not show any departure from random alignment with respect to the cluster. We therefore claim that the alignment process originates from the same process that makes the BCG grow dominant, be it direct mergers in the early stage of cluster formation, or a later process that resembles the galactic cannibalism scenario. We do not find strong evidence for (or against) redshift evolution between 0sample size (< 200 clusters). However, we have developed a framework by which we can examine many more clusters in an automated fashion for the upcoming SDSS cluster catalogs, which will provide us with better statistics for systematic investigations of the alignment with redshift, richness and morphology of both the cluster and the BCG.

  9. ISO's Contribution to the Study of Clusters of Galaxies

    E-Print Network [OSTI]

    L. Metcalfe; D. Fadda; A. Biviano

    2005-08-22T23:59:59.000Z

    Starting with nearby galaxy clusters like Virgo and Coma, and continuing out to the furthest galaxy clusters for which ISO results have yet been published ($z=0.56$), we discuss the development of knowledge of the infrared and associated physical properties of galaxy clusters from early IRAS observations, through the "ISO-era" to the present, in order to explore the status of ISO's contribution to this field. Relevant IRAS and ISO programmes are reviewed, addressing both the cluster galaxies and the still-very-limited evidence for an infrared-emitting intra-cluster medium. ISO made important advances in knowledge of both nearby and distant galaxy clusters, such as the discovery of a major cold dust component in Virgo and Coma cluster galaxies, the elaboration of the correlation between dust emission and Hubble-type, and the detection of numerous Luminous Infrared Galaxies (LIRGs) in several distant clusters. These and consequent achievements are underlined and described. We recall that, due to observing time constraints, ISO's coverage of higher-redshift galaxy clusters to the depths required to detect and study statistically significant samples of cluster galaxies over a range of morphological types could not be comprehensive and systematic, and such systematic coverage of distant clusters will be an important achievement of the Spitzer Observatory.

  10. ZIRCONIUM, BARIUM, LANTHANUM, AND EUROPIUM ABUNDANCES IN OPEN CLUSTERS

    SciTech Connect (OSTI)

    Jacobson, Heather R. [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48823 (United States); Friel, Eileen D., E-mail: jacob189@msu.edu, E-mail: efriel@indiana.edu, E-mail: hrj@mit.edu [Department of Astronomy, Indiana University, Bloomington, IN 47405 (United States)

    2013-04-15T23:59:59.000Z

    We present an analysis of the s-process elements Zr, Ba, and La and the r-process element Eu in a sample of 50 stars in 19 open clusters. Stellar abundances of each element are based on measures of a minimum of two lines per species via both equivalent width and spectrum synthesis techniques. We investigate cluster mean neutron-capture abundance trends as a function of cluster age and location in the Milky Way disk and compare them to results found in other studies in the literature. We find a statistically significant trend of increasing cluster [Ba/Fe] as a function of decreasing cluster age, in agreement with recent findings for other open cluster samples, supporting the increased importance of low-mass asymptotic giant branch stars to the generation of s-process elements. However, the other s-process elements, [La/Fe] and [Zr/Fe], do not show similar dependences, in contrast to theoretical expectations and the limited observational data from other studies. Conversely, cluster [Eu/Fe] ratios show a slight increase with increasing cluster age, although with marginal statistical significance. Ratios of [s/r]-process abundances, [Ba/Eu] and [La/Eu], however, show more clearly the increasing efficiency of s-process relative to r-process enrichment in open cluster chemical evolution, with significant increases among younger clusters. Last, cluster neutron-capture element abundances appear to be independent of Galactocentric distance. We conclude that a homogeneous analysis of a larger sample of open clusters is needed to resolve the apparent discrepant conclusions between different studies regarding s-process element abundance trends with age to better inform models of galactic chemical evolution.

  11. Recap Clustering: Introduction Clustering in IR K-means Evaluation How many clusters? Introduction to Information Retrieval

    E-Print Network [OSTI]

    Nejdl, Wolfgang

    Recap Clustering: Introduction Clustering in IR K-means Evaluation How many clusters? Introduction;Recap Clustering: Introduction Clustering in IR K-means Evaluation How many clusters? Overview 1 Recap 2 Clustering: Introduction 3 Clustering in IR 4 K-means 5 Evaluation 6 How many clusters? Sch¨utze: Flat

  12. Heating Rate Profiles in Galaxy Clusters

    E-Print Network [OSTI]

    Edward C. D. Pope; Georgi Pavlovski; Christian R. Kaiser; Hans Fangohr

    2006-01-05T23:59:59.000Z

    In recent years evidence has accumulated suggesting that the gas in galaxy clusters is heated by non-gravitational processes. Here we calculate the heating rates required to maintain a physically motived mass flow rate, in a sample of seven galaxy clusters. We employ the spectroscopic mass deposition rates as an observational input along with temperature and density data for each cluster. On energetic grounds we find that thermal conduction could provide the necessary heating for A2199, Perseus, A1795 and A478. However, the suppression factor, of the clasical Spitzer value, is a different function of radius for each cluster. Based on the observations of plasma bubbles we also calculate the duty cycles for each AGN, in the absence of thermal conduction, which can provide the required energy input. With the exception of Hydra-A it appears that each of the other AGNs in our sample require duty cycles of roughly $10^{6}-10^{7}$ yrs to provide their steady-state heating requirements. If these duty cycles are unrealistic, this may imply that many galaxy clusters must be heated by very powerful Hydra-A type events interspersed between more frequent smaller-scale outbursts. The suppression factors for the thermal conductivity required for combined heating by AGN and thermal conduction are generally acceptable. However, these suppression factors still require `fine-tuning` of the thermal conductivity as a function of radius. As a consequence of this work we present the AGN duty cycle as a cooling flow diagnostic.

  13. ReportTechnical Sampling and Clustering of the Space

    E-Print Network [OSTI]

    M. Stommel and M. Beetz Institute for Artificial Intelligence, Center for Computing and Comunication- portant to detect the human body from video data and estimate its pose. A number of different approaches to detect persons in a video and separate them from background. We use RGBD- cameras to record the input

  14. Blue Stragglers in Low-Luminosity Star Clusters

    E-Print Network [OSTI]

    Eric L. Sandquist

    2005-10-26T23:59:59.000Z

    We examine the blue straggler populations of 13 low-luminosity (M_V_t >~ -6) globular clusters and 2 old open clusters. These clusters test blue straggler formation in environments intermediate between higher luminosity (and usually higher density) clusters and the Galactic field. The anti-correlation between the relative frequency of blue stragglers (F_BSS = N_BSS / N_HB) and cluster luminosity continues to the lowest luminosity clusters, which have frequencies meeting or exceeding that of field stars. In addition we find that the anti-correlation between straggler frequency and central density disappears for clusters with density less than about 300 L_V,sun pc^-3, although this appears to be an artifact of the correlation between cluster luminosity and central density. We argue on observational (wide, eccentric binaries containing blue stragglers in M67, and the existence of very bright stragglers in most of the clusters in our sample) and theoretical grounds that stellar collisions still produce a significant fraction of the blue stragglers in low luminosity star clusters due to the long-term survival of wide binaries.

  15. Deriving physical parameters of unresolved star clusters III. Application to M31 PHAT clusters

    E-Print Network [OSTI]

    de Meulenaer, Philippe; Mineikis, Tadas; Vansevi?ius, Vladas

    2015-01-01T23:59:59.000Z

    This study is the third of a series that investigates the degeneracy and stochasticity problems present in the determination of physical parameters such as age, mass, extinction, and metallicity of partially resolved or unresolved star cluster populations situated in external galaxies when using broad-band photometry. This work tests the derivation of parameters of artificial star clusters using models with fixed and free metallicity for the WFC3+ACS photometric system. Then the method is applied to derive parameters of a sample of 203 star clusters in the Andromeda galaxy observed with the HST. Following Papers I \\& II, the star cluster parameters are derived using a large grid of stochastic models that are compared to the observed cluster broad-band integrated WFC3+ACS magnitudes. We derive the age, mass, and extinction of the sample of M31 star clusters with one fixed metallicity in agreement with previous studies. Using artificial tests we demonstrate the ability of the WFC3+ACS photometric system to ...

  16. Subaru Weak Lensing Measurements of Four Strong Lensing Clusters: Are Lensing Clusters Over-Concentrated?

    SciTech Connect (OSTI)

    Oguri, Masamune; Hennawi, Joseph F.; Gladders, Michael D.; Dahle, Haakon; Natarajan, Priyamvada; Dalal, Neal; Koester, Benjamin P.; Sharon, Keren; Bayliss, Matthew

    2009-01-29T23:59:59.000Z

    We derive radial mass profiles of four strong lensing selected clusters which show prominent giant arcs (Abell 1703, SDSS J1446+3032, SDSS J1531+3414, and SDSS J2111-0115), by combining detailed strong lens modeling with weak lensing shear measured from deep Subaru Suprime-cam images. Weak lensing signals are detected at high significance for all four clusters, whose redshifts range from z = 0.28 to 0.64. We demonstrate that adding strong lensing information with known arc redshifts significantly improves constraints on the mass density profile, compared to those obtained from weak lensing alone. While the mass profiles are well fitted by the universal form predicted in N-body simulations of the {Lambda}-dominated cold dark matter model, all four clusters appear to be slightly more centrally concentrated (the concentration parameters c{sub vir} {approx} 8) than theoretical predictions, even after accounting for the bias toward higher concentrations inherent in lensing selected samples. Our results are consistent with previous studies which similarly detected a concentration excess, and increases the total number of clusters studied with the combined strong and weak lensing technique to ten. Combining our sample with previous work, we find that clusters with larger Einstein radii are more anomalously concentrated. We also present a detailed model of the lensing cluster Abell 1703 with constraints from multiple image families, and find the dark matter inner density profile to be cuspy with the slope consistent with -1, in agreement with expectations.

  17. Sampling diffusive transition paths

    E-Print Network [OSTI]

    F. Miller III, Thomas

    2009-01-01T23:59:59.000Z

    Sampling di?usive transition paths Thomas F. Miller III ?the algorithm to sample the transition path ensemble for thedynamics I. INTRODUCTION Transition path sampling (TPS) is a

  18. Feature Level Clustering of Large Biometric Database

    E-Print Network [OSTI]

    Mehrotra, Hunny; Radhika, V Bhawani; Majhi, Banshidhar; Gupta, Phalguni

    2010-01-01T23:59:59.000Z

    This paper proposes an efficient technique for partitioning large biometric database during identification. In this technique feature vector which comprises of global and local descriptors extracted from offline signature are used by fuzzy clustering technique to partition the database. As biometric features posses no natural order of sorting, thus it is difficult to index them alphabetically or numerically. Hence, some supervised criteria is required to partition the search space. At the time of identification the fuzziness criterion is introduced to find the nearest clusters for declaring the identity of query sample. The system is tested using bin-miss rate and performs better in comparison to traditional k-means approach.

  19. Clustering versus non-clustering phase synchronizations

    SciTech Connect (OSTI)

    Liu, Shuai [Wuhan Center for Magnetic Resonance, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China) [Wuhan Center for Magnetic Resonance, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Zhan, Meng, E-mail: zhanmeng@wipm.ac.cn [Wuhan Center for Magnetic Resonance, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China)] [Wuhan Center for Magnetic Resonance, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China)

    2014-03-15T23:59:59.000Z

    Clustering phase synchronization (CPS) is a common scenario to the global phase synchronization of coupled dynamical systems. In this work, a novel scenario, the non-clustering phase synchronization (NPS), is reported. It is found that coupled systems do not transit to the global synchronization until a certain sufficiently large coupling is attained, and there is no clustering prior to the global synchronization. To reveal the relationship between CPS and NPS, we further analyze the noise effect on coupled phase oscillators and find that the coupled oscillator system can change from CPS to NPS with the increase of noise intensity or system disorder. These findings are expected to shed light on the mechanism of various intriguing self-organized behaviors in coupled systems.

  20. MultiCriteria Clustering & Classification

    E-Print Network [OSTI]

    Libre de Bruxelles, Université

    An Extension of the K-Means' algorithm MultiCriteria Ordered Clustering 6 MCDA Classification : Sorting MCDACriteria Comparison : motivation A MCDA approach for grouping problems 5 MCDA Clustering Multicriteria Clustering

  1. Cold cluster ferromagnetism

    SciTech Connect (OSTI)

    Bertsch, G.F. [Institute for Nuclear Theory and Department of Physics FM-15, University of Washington, Seattle, Washington 98195 (United States)] [Institute for Nuclear Theory and Department of Physics FM-15, University of Washington, Seattle, Washington 98195 (United States); Yabana, K. [Department of Physics, Niigata University, Niigata 950-21 (Japan)] [Department of Physics, Niigata University, Niigata 950-21 (Japan)

    1994-03-01T23:59:59.000Z

    We examine the magnetic-moment distribution of ferromagnetic clusters under conditions where the magnetic moment is aligned with the internal cluster axis. Analytic expressions are obtained for the moment distribution and the adiabatic average moment induced in low fields. The result differs from the low-field Langevin function by a factor 2/3.

  2. Cool Cluster Correctly Correlated

    SciTech Connect (OSTI)

    Sergey Aleksandrovich Varganov

    2005-12-17T23:59:59.000Z

    Atomic clusters are unique objects, which occupy an intermediate position between atoms and condensed matter systems. For a long time it was thought that physical and chemical properties of atomic dusters monotonically change with increasing size of the cluster from a single atom to a condensed matter system. However, recently it has become clear that many properties of atomic clusters can change drastically with the size of the clusters. Because physical and chemical properties of clusters can be adjusted simply by changing the cluster's size, different applications of atomic clusters were proposed. One example is the catalytic activity of clusters of specific sizes in different chemical reactions. Another example is a potential application of atomic clusters in microelectronics, where their band gaps can be adjusted by simply changing cluster sizes. In recent years significant advances in experimental techniques allow one to synthesize and study atomic clusters of specified sizes. However, the interpretation of the results is often difficult. The theoretical methods are frequently used to help in interpretation of complex experimental data. Most of the theoretical approaches have been based on empirical or semiempirical methods. These methods allow one to study large and small dusters using the same approximations. However, since empirical and semiempirical methods rely on simple models with many parameters, it is often difficult to estimate the quantitative and even qualitative accuracy of the results. On the other hand, because of significant advances in quantum chemical methods and computer capabilities, it is now possible to do high quality ab-initio calculations not only on systems of few atoms but on clusters of practical interest as well. In addition to accurate results for specific clusters, such methods can be used for benchmarking of different empirical and semiempirical approaches. The atomic clusters studied in this work contain from a few atoms to tens of atoms. Therefore, they are quantum objects. Some qualitative information about the geometries of such clusters can be obtained with classical empirical methods, for example geometry optimization using an empirical Lennard-Jones potential. However, to predict their accurate geometries and other physical and chemical properties it is necessary to solve a Schroedinger equation. If one is not interested in dynamics of clusters it is enough to solve the stationary (time-independent) Schroedinger equation (H{Phi}=E{Phi}). This equation represents a multidimensional eigenvalue problem. The solution of the Schroedinger equation is a set of eigenvectors (wave functions) and their eigenvalues (energies). The lowest energy solution (wave function) corresponds to the ground state of the cluster. The other solutions correspond to excited states. The wave function gives all information about the quantum state of the cluster and can be used to calculate different physical and chemical properties, such as photoelectron, X-ray, NMR, EPR spectra, dipole moment, polarizability etc. The dimensionality of the Schroedinger equation is determined by the number of particles (nuclei and electrons) in the cluster. The analytic solution is only known for a two particle problem. In order to solve the equation for clusters of interest it is necessary to make a number of approximations and use numerical methods.

  3. The Baltimore and Utrecht models for cluster dissolution

    E-Print Network [OSTI]

    Henny J. G. L. M. Lamers

    2008-04-14T23:59:59.000Z

    The analysis of the age distributions of star cluster samples of different galaxies has resulted in two very different empirical models for the dissolution of star clusters: the Baltimore model and the Utrecht model. I describe these two models and their differences. The Baltimore model implies that the dissolution of star clusters is mass independent and that about 90% of the clusters are destroyed each age dex, up to an age of about a Gyr, after which point mass-dependent dissolution from two-body relaxation becomes the dominant mechanism. In the Utrecht model, cluster dissolution occurs in three stages: (i) mass-independent infant mortality due to the expulsion of gas up to about 10 Myr; (ii) a phase of slow dynamical evolution with strong evolutionary fading of the clusters lasting up to about a Gyr; and (iii) a phase dominated by mass dependent-dissolution, as predicted by dynamical models. I describe the cluster age distributions for mass-limited and magnitude-limited cluster samples for both models. I refrain from judging the correctness of these models.

  4. STAR CLUSTER DISRUPTION IN THE STARBURST GALAXY MESSIER 82

    SciTech Connect (OSTI)

    Li, Shuo; Li, Chengyuan [Department of Astronomy, Peking University, Yi He Yuan Lu 5, Hai Dian District, Beijing 100871 (China); De Grijs, Richard [Kavli Institute for Astronomy and Astrophysics, Peking University, Yi He Yuan Lu 5, Hai Dian District, Beijing 100871 (China); Anders, Peter, E-mail: grijs@pku.edu.cn [Key Laboratory for Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012 (China)

    2015-01-01T23:59:59.000Z

    Using high-resolution, multiple-passband Hubble Space Telescope images spanning the entire optical/near-infrared wavelength range, we obtained a statistically complete U-band-selected sample of 846 extended star clusters across the disk of the nearby starburst galaxy M82. Based on a careful analysis of the clusters' spectral energy distributions, we determined their galaxy-wide age and mass distributions. The M82 clusters exhibit three clear peaks in their age distribution, thus defining relatively young, log (t yr{sup –1}) ? 7.5, intermediate-age, log (t yr{sup –1}) in [7.5, 8.5], and old samples, log (t yr{sup –1}) ? 8.5. Comparison of the completeness-corrected mass distributions offers a firm handle on the galaxy's star cluster disruption history. The most massive star clusters in the young and old samples are (almost) all concentrated in the most densely populated central region, while the intermediate-age sample's most massive clusters are more spatially dispersed, which may reflect the distribution of the highest-density gas throughout the galaxy's evolutionary history, combined with the solid-body nature of the galaxy's central region.

  5. Clustering in nuclear environment

    E-Print Network [OSTI]

    G. Röpke

    2014-08-12T23:59:59.000Z

    The properties of few-body clusters (mass number $A \\le 4$) are modified if they are immersed in a nuclear medium. In particular, Pauli blocking that reflects the antisymmetrization of the many-body wave function is responsible for the medium modification of light clusters and the dissolution with increasing density. A more consistent description is given with takes also the contribution of correlations in the continuum into account. The relation between cluster formation in warm dense matter and in nuclear structure is discussed.

  6. Galaxy clusters and groups in the ALHAMBRA Survey

    E-Print Network [OSTI]

    Ascaso, Begoña; Fernández-Soto, Alberto; Arnalte-Mur, Pablo; López-Sanjuan, Carlos; Molino, Alberto; Schoenell, William; Jiménez-Teja, Yolanda; Merson, Alexander I; Huertas-Company, Marc; Díaz-García, Luis Alberto; Martínez, Vicent J; Cenarro, A Javier; Dupke, Renato; Márquez, Isabel; Masegosa, Josefa; Nieves-Seoane, Lorena; Povic, Mirjana; Varela, Jesús; Viironen, Kerttu; Aguerri, J Alfonso L; Del Olmo, Ascensión; Moles, Mariano; Perea, Jaime; Alfaro, Emilio; Aparicio-Villegas, Teresa; Broadhurst, Tom; Cabrera-Caño, Jesús; Castander, Francisco J; Cepa, Jordi; Cerviño, Miguel; González~Delgado, Rosa M; Cristóbal-Hornillos, David; Hurtado-Gil, Lluis; Husillos, Cesar; Infante, Leopoldo; Prada, Francisco; Quintana, Jose María

    2015-01-01T23:59:59.000Z

    We present a catalogue of 348 galaxy clusters and groups with $0.2seven ALHAMBRA pointings ensure that this catalogue has better mass sensitivity and is less affected by cosmic variance than comparable samples. The detection has been carried out with the Bayesian Cluster Finder (BCF), whose performance has been checked in ALHAMBRA-like light-cone mock catalogues. Great care has been taken to ensure that the observable properties of the mocks photometry accurately correspond to those of real catalogues. From our simulations, we expect to detect galaxy clusters and groups with both $70\\%$ completeness and purity down to dark matter halo masses of $M_h\\sim3\\times10^{13}\\rm M_{\\odot}$ for $z<0.85$. Cluster redshifts are expected to be recovered with $\\sim0.6\\%$ precision for $z<1$. We also expect to measure cluster masses with $\\sigma_{M_h|M^*_{CL}}\\sim0.25-...

  7. Clusters and entrepreneurship

    E-Print Network [OSTI]

    Delgado, Mercedes

    This article examines the role of regional clusters in regional entrepreneurship. We focus on the distinct influences of convergence and agglomeration on growth in the number of start-up firms as well as in employment in ...

  8. Evaluation and comparison of gene clustering methods in

    E-Print Network [OSTI]

    Tseng, George C. "Chien-Cheng"

    ., 1998) K-means (MacQueen, 1967; Hartigan, 1975) K-memoids (PAM) Self-organizing maps (SOM) (Kohonen clustering Different choices of linkage: single, complete, average, centroid #12;2.1 Method 2: K-means Original Data X co-membership matrix D[C(X', k), X] sub-sample X' cluster centers C(X', k)=(C1,..., Ck) K-means

  9. Open Cluster Open Cluster Open Cluster A group of several thousand stars

    E-Print Network [OSTI]

    Bechtold, Jill

    Open Cluster Open Cluster Open Cluster A group of several thousand stars which formed within the same nebula. The Pleides, or Seven Sisters, are the most visible stars in this cluster in the Milky Way. Mass:10-10,000 SM StarPower Points: 11 A group of several thousand stars which formed within the same

  10. The Galaxy Population of Low-Redshift Abell Clusters

    E-Print Network [OSTI]

    Barkhouse, Wayne A; Lopez-Cruz, Omar

    2009-01-01T23:59:59.000Z

    We present a study of the luminosity and color properties of galaxies selected from a sample of 57 low-redshift Abell clusters. We utilize the non-parametric dwarf-to-giant ratio (DGR) and the blue galaxy fraction (fb) to investigate the clustercentric radial-dependent changes in the cluster galaxy population. Composite cluster samples are combined by scaling the counting radius by r200 to minimize radius selection bias. The separation of galaxies into a red and blue population was achieved by selecting galaxies relative to the cluster color-magnitude relation. The DGR of the red and blue galaxies is found to be independent of cluster richness (Bgc), although the DGR is larger for the blue population at all measured radii. A decrease in the DGR for the red and red+blue galaxies is detected in the cluster core region, while the blue galaxy DGR is nearly independent of radius. The fb is found not to correlate with Bgc; however, a steady decline toward the inner-cluster region is observed for the giant galaxies....

  11. Zirconium, Barium, Lanthanum and Europium Abundances in Open Clusters

    E-Print Network [OSTI]

    Jacobson, H R; 10.1088/0004-6256/145/4/107

    2013-01-01T23:59:59.000Z

    We present an analysis of the s-process elements Zr, Ba, and La and the r-process element Eu in a sample of 50 stars in 19 open clusters. Stellar abundances of each element are based on measures of a minimum of two lines per species via both equivalent width and spectrum synthesis techniques. We investigate cluster mean neutron-capture abundance trends as a function of cluster age and location in the Milky Way disk and compare them to results found in other studies in the literature. We find a statistically significant trend of increasing cluster [Ba/Fe] as a function of decreasing cluster age, in agreement with recent findings for other open cluster samples, supporting the increased importance of low-mass asymptotic giant branch stars to the generation of s-process elements. However, the other s-process elements, [La/Fe] and [Zr/Fe], do not show similar dependences, in contrast to theoretical expectations and the limited observational data from other studies. Conversely, cluster [Eu/Fe] ratios show a slight ...

  12. ESPC IDIQ Contract Sample

    Broader source: Energy.gov [DOE]

    Document displays a sample indefinite delivery, indefinite quantity (IDIQ) energy savings performance contract (ESPC).

  13. Are the Effects of Structure Formation Seen in the Central Metallicity of Galaxy Clusters?

    E-Print Network [OSTI]

    Elkholy, Tamer Y; Canizares, Claude R

    2015-01-01T23:59:59.000Z

    A sample of 46 nearby clusters observed with Chandra is analyzed to produce radial density, temperature, entropy and metallicity profiles, as well as other morphological measurements. The entropy profiles are computed to larger radial extents than in previous Chandra cluster sample analyses. We find that the iron mass fraction measured in the inner 0.15 R500 shows a larger dispersion across the sample of low-mass clusters, than it does for the sample of high-mass clusters. We interpret this finding as the result of the mixing of more haloes in large clusters than in small clusters, which leads to an averaging of the metal content in the large clusters, and thus less dispersion of metallicity for high-mass clusters. This interpretation lends support to the idea that the low-entropy, metal-rich gas of merging haloes reaches clusters' centers, which explains observations of Core-Collapse Supernova products metallicity peaks, and which is seen in hydrodynamical simulations. The gas in these merging haloes would h...

  14. Control rod cluster arrangement

    SciTech Connect (OSTI)

    Orr, W.L.; Doshi, P.K.; Mildrum, C.M.; Freeman, T.R.

    1987-02-10T23:59:59.000Z

    This patent describes a nuclear reactor including nuclear core which is cooled and moderated by light water, the nuclear core comprising a plurality of parallel arranged openings therethrough and interspersed among the fuel assemblies. A control rod cluster arrangement comprises load follow control rod cluster assemblies with each load follow control rod cluster assembly being adapted to slidingly fit within each of some of the fuel assemblies in the parallel arranged openings, the load follow control rod cluster assemblies each comprising a plurality of elongated parallel arranged rods attached to a single spider, and including a first group of rods and a second group of rods, the first group of rods and the second each consisting of a plurality of absorber rods. The first group of rods consist of absorber rods taken from the group consisting of B/sub 4/C, hafnium, or silver-indium-cadmium and the second group of rods consist of absorber rods each consisting of stainless steel, the first group of rods and the second group of rods each being integrally attached at all times to the single spider, the absorber rods of the second group of rods being dispersed throughout the control rod cluster assembly. The first group of rods have a first neutron capture cross section and the second group of rods have a second neutron capture cross section different from the first cross section.

  15. ROTATING GLOBULAR CLUSTERS

    SciTech Connect (OSTI)

    Bianchini, P.; Varri, A. L. [Now at Department of Astronomy, Indiana University, 727 East 3rd Street, Swain West 319, Bloomington, IN 47405-7105 (United States); Bertin, G.; Zocchi, A., E-mail: bianchini@mpia.de [Dipartimento di Fisica, Universita degli Studi di Milano, via Celoria 16, I-20133 Milano (Italy)

    2013-07-20T23:59:59.000Z

    Internal rotation is thought to play a major role in the dynamics of some globular clusters. However, in only a few cases has internal rotation been studied by the quantitative application of realistic and physically justified global models. Here, we present a dynamical analysis of the photometry and three-dimensional kinematics of {omega} Cen, 47 Tuc, and M15, by means of a recently introduced family of self-consistent axisymmetric rotating models. The three clusters, characterized by different relaxation conditions, show evidence of differential rotation and deviations from sphericity. The combination of line-of-sight velocities and proper motions allows us to determine their internal dynamics, predict their morphology, and estimate their dynamical distance. The well-relaxed cluster 47 Tuc is interpreted very well by our model; internal rotation is found to explain the observed morphology. For M15, we provide a global model in good agreement with the data, including the central behavior of the rotation profile and the shape of the ellipticity profile. For the partially relaxed cluster {omega} Cen, the selected model reproduces the complex three-dimensional kinematics; in particular, the observed anisotropy profile, characterized by a transition from isotropy to weakly radial anisotropy and then to tangential anisotropy in the outer parts. The discrepancy found for the steep central gradient in the observed line-of-sight velocity dispersion profile and for the ellipticity profile is ascribed to the condition of only partial relaxation of this cluster and the interplay between rotation and radial anisotropy.

  16. Thermodynamics of clusterized matter

    E-Print Network [OSTI]

    Ad. R. Raduta; F. Gulminelli

    2009-08-26T23:59:59.000Z

    Thermodynamics of clusterized matter is studied in the framework of statistical models with non-interacting cluster degrees of freedom. At variance with the analytical Fisher model, exact Metropolis simulation results indicate that the transition from homogeneous to clusterized matter lies along the $\\rho=\\rho_0$ axis at all temperatures and the limiting point of the phase diagram is not a critical point even if the surface energy vanishes at this point. Sensitivity of the inferred phase diagram to the employed statistical framework in the case of finite systems is discussed by considering the grand-canonical and constant-pressure canonical ensembles. A Wigner-Seitz formalism in which the fragment charge is neutralized by an uniform electron distribution allows to build the phase diagram of neutron star matter.

  17. The Infrared Luminosity of Galaxy Clusters

    E-Print Network [OSTI]

    Martin Giard; Ludovic Montier; Etienne Pointecouteau; Ellen Simmat

    2008-08-28T23:59:59.000Z

    The aim of this study is to quantify the infrared luminosity of clusters as a function of redshift and compare this with the X-ray luminosity. This can potentially constrain the origin of the infrared emission to be intracluster dust and/or dust heated by star formation in the cluster galaxies. We perform a statistical analysis of a large sample of galaxy clusters selected from existing databases and catalogues.We coadd the infrared IRAS and X-ray RASS images in the direction of the selected clusters within successive redshift intervals up to z = 1. We find that the total infrared luminosity is very high and on average 20 times higher than the X-ray luminosity. If all the infrared luminosity is to be attributed to emission from diffuse intracluster dust, then the IR to X-ray ratio implies a dust-to-gas mass abundance of 5e-4. However, the infrared luminosity shows a strong enhancement for 0.1 infrared luminosity that we measure is generated by the ongoing star formation in the member galaxies. From theoretical predictions calibrated on extinction measurements (dust mass abundance equal to 1e-5), we expect only a minor contribution, of a few percent, from intracluster dust.

  18. Evidence for temporal evolution in the M33 disc as traced by its star clusters

    E-Print Network [OSTI]

    Beasley, Michael A; Gallart, Carme; Sarajedini, Ata; Aparicio, Antonio

    2015-01-01T23:59:59.000Z

    We present precision radial velocities and stellar population parameters for 77 star clusters in the Local Group galaxy M33. Our GTC and WHT observations sample both young, massive clusters and known/candidate globular clusters, spanning ages ~ 10^6 - 10^10 yr, and metallicities, [M/H] ~-1.7 to solar. The cluster system exhibits an age-metallicity relation; the youngest clusters are the most metal-rich. When compared to HI data, clusters with [M/H] ~ -1.0 and younger than ~ 4 Gyr are clearly identified as a disc population. The clusters show evidence for strong time evolution in the disc radial metallicity gradient (d[M/H]dt / dR = 0.03 dex/kpc/Gyr). The oldest clusters have stronger, more negative gradients than the youngest clusters in M33. The clusters also show a clear age-velocity dispersion relation. The line of sight velocity dispersions of the clusters increases with age similar to Milky Way open clusters and stars. The general shape of the relation is reproduced by disc heating simulations, and the s...

  19. Rain sampling device

    DOE Patents [OSTI]

    Nelson, D.A.; Tomich, S.D.; Glover, D.W.; Allen, E.V.; Hales, J.M.; Dana, M.T.

    1991-05-14T23:59:59.000Z

    The present invention constitutes a rain sampling device adapted for independent operation at locations remote from the user which allows rainfall to be sampled in accordance with any schedule desired by the user. The rain sampling device includes a mechanism for directing wet precipitation into a chamber, a chamber for temporarily holding the precipitation during the process of collection, a valve mechanism for controllably releasing samples of the precipitation from the chamber, a means for distributing the samples released from the holding chamber into vessels adapted for permanently retaining these samples, and an electrical mechanism for regulating the operation of the device. 11 figures.

  20. Rain sampling device

    DOE Patents [OSTI]

    Nelson, Danny A. (Richland, WA); Tomich, Stanley D. (Richland, WA); Glover, Donald W. (Prosser, WA); Allen, Errol V. (Benton City, WA); Hales, Jeremy M. (Kennewick, WA); Dana, Marshall T. (Richland, WA)

    1991-01-01T23:59:59.000Z

    The present invention constitutes a rain sampling device adapted for independent operation at locations remote from the user which allows rainfall to be sampled in accordance with any schedule desired by the user. The rain sampling device includes a mechanism for directing wet precipitation into a chamber, a chamber for temporarily holding the precipitation during the process of collection, a valve mechanism for controllably releasing samples of said precipitation from said chamber, a means for distributing the samples released from the holding chamber into vessels adapted for permanently retaining these samples, and an electrical mechanism for regulating the operation of the device.

  1. Spectral Clustering for Complex Settings

    E-Print Network [OSTI]

    Wang, Xiang

    2013-01-01T23:59:59.000Z

    and T. Li. Integrated KL (K-means - Laplacian) clustering: Aschemes, such as K-means, hierarchical clustering, densityclustering algorithms such as K-means can only find a local

  2. Logistics clusters : prevalence and impact

    E-Print Network [OSTI]

    Rivera Virgüez, Myriam Liliana

    2014-01-01T23:59:59.000Z

    Governments around the world are investing significant resources in the development and expansion of logistics clusters. This dissertation analyzes the cluster phenomenon focusing on four topics. First, it develops a ...

  3. On the Nature of the EIS Candidate Clusters: Confirmation of z<0.6 candidates

    E-Print Network [OSTI]

    L. F. Olsen; C. Benoist; L. da Costa; M. Scodeggio; H. E. Jorgensen; S. Arnouts; S. Bardelli; A. Biviano; M. Ramella; E. Zucca

    2001-10-21T23:59:59.000Z

    We use public V-band imaging data from the wide-angle surveys conducted by the ESO Imaging Survey project (EIS) to further investigate the nature of the EIS galaxy cluster candidates. These were originally identified by applying a matched-filter algorithm which used positional and photometric data of the galaxy sample extracted from the I-band survey images. In this paper, we apply the same technique to the galaxy sample extracted from V-band data and compare the new cluster detections with the original ones. We find that ~75% of the low-redshift cluster candidates (zEIS clusters with z_I<0.6 are real, making it one of the largest samples of galaxy clusters in this redshift range currently available in the southern hemisphere.

  4. Nonparametric Bayesian analysis of some clustering problems

    E-Print Network [OSTI]

    Ray, Shubhankar

    2006-10-30T23:59:59.000Z

    it useful for clustering problems where the number of clusters is unknown. We develop nonparametric Bayesian models for two different clustering problems, namely functional and graphical clustering. We propose a nonparametric Bayes wavelet model...

  5. COMPUTER SCIENCE SAMPLE PROGRAM

    E-Print Network [OSTI]

    Gering, Jon C.

    COMPUTER SCIENCE SAMPLE PROGRAM (First Math Course MATH 198) This sample program suggests one way CS 181: Foundations of Computer Science II CS 180: Foundations of Computer Science I CS 191

  6. Clustering Chain Additional options

    E-Print Network [OSTI]

    Linial, Michal

    ProtoClass -rationale and concept ProtoNet in brief AND BEYOND: Functional roadmap in Proto-à-vis InterPro, SCOP, FSSP etc #12;6 ProtoClass Road-Maps A horizontal view provides `distances' between clusters. Those are the basis for creating Road-Maps. We test the biological content of those road maps

  7. The Globular Cluster Luminosity Function

    E-Print Network [OSTI]

    Dean E. McLaughlin

    2003-02-14T23:59:59.000Z

    The main aspects of the globular cluster luminosity function needing to be explained by a general theory of cluster formation are reviewed, and the importance of simultaneously understanding globular cluster systematics (the fundamental plane) within such a theory is pointed out.

  8. Derivatized gold clusters and antibody-gold cluster conjugates

    DOE Patents [OSTI]

    Hainfeld, J.F.; Furuya, F.R.

    1994-11-01T23:59:59.000Z

    Antibody- or antibody fragment-gold cluster conjugates are shown wherein the conjugate size can be as small as 5.0 nm. Methods and reagents are disclosed in which antibodies, Fab' or F(ab')[sub 2] fragments are covalently bound to a stable cluster of gold atoms. The gold clusters may contain 6, 8, 9, 11, 13, 55 or 67 gold atoms in their inner core. The clusters may also contain radioactive gold. The antibody-cluster conjugates are useful in electron microscopy applications as well as in clinical applications that include imaging, diagnosis and therapy. 7 figs.

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

    SciTech Connect (OSTI)

    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

    2012-06-20T23:59:59.000Z

    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.

  10. THE PANCHROMATIC HUBBLE ANDROMEDA TREASURY. III. MEASURING AGES AND MASSES OF PARTIALLY RESOLVED STELLAR CLUSTERS

    SciTech Connect (OSTI)

    Beerman, Lori C.; Johnson, L. Clifton; Fouesneau, Morgan; Dalcanton, Julianne J.; Weisz, Daniel R.; Williams, Ben F. [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); Bell, Eric F. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Bianchi, Luciana C. [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Caldwell, Nelson [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Dolphin, Andrew E. [Raytheon Company, 1151 East Hermans Road, Tucson, AZ 85756 (United States); Gouliermis, Dimitrios A. [Zentrum fuer Astronomie, Institut fuer Theoretische Astrophysik, Universitaet Heidelberg, Albert-Ueberle-Strasse 2, D-69120 Heidelberg (Germany); Kalirai, Jason S. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Larsen, Soren S. [Department of Astrophysics, IMAPP, Radboud University Nijmegen, P.O. Box 9010, NL-6500 GL Nijmegen (Netherlands); Melbourne, Jason L. [Caltech Optical Observatories, Division of Physics, Mathematics and Astronomy, Mail Stop 301-17, California Institute of Technology, Pasadena, CA 91125 (United States); Rix, Hans-Walter [Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany); Skillman, Evan D., E-mail: beermalc@astro.washington.edu [Department of Astronomy, University of Minnesota, 116 Church Street SE, Minneapolis, MN 55455 (United States)

    2012-12-01T23:59:59.000Z

    The apparent age and mass of a stellar cluster can be strongly affected by stochastic sampling of the stellar initial mass function (IMF), when inferred from the integrated color of low-mass clusters ({approx}<10{sup 4} M {sub Sun }). We use simulated star clusters to show that these effects are minimized when the brightest, rapidly evolving stars in a cluster can be resolved, and the light of the fainter, more numerous unresolved stars can be analyzed separately. When comparing the light from the less luminous cluster members to models of unresolved light, more accurate age estimates can be obtained than when analyzing the integrated light from the entire cluster under the assumption that the IMF is fully populated. We show the success of this technique first using simulated clusters, and then with a stellar cluster in M31. This method represents one way of accounting for the discrete, stochastic sampling of the stellar IMF in less massive clusters and can be leveraged in studies of clusters throughout the Local Group and other nearby galaxies.

  11. CLUSTER LENSING PROFILES DERIVED FROM A REDSHIFT ENHANCEMENT OF MAGNIFIED BOSS-SURVEY GALAXIES

    SciTech Connect (OSTI)

    Coupon, Jean; Umetsu, Keiichi [Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan (China); Broadhurst, Tom, E-mail: coupon@asiaa.sinica.edu.tw [Department of Theoretical Physics, University of Basque Country UPV/EHU, P.O. Box 644, E-48080 Bilbao (Spain)

    2013-07-20T23:59:59.000Z

    We report the first detection of a redshift-depth enhancement of background galaxies magnified by foreground clusters. Using 300,000 BOSS survey galaxies with accurate spectroscopic redshifts, we measure their mean redshift depth behind four large samples of optically selected clusters from the Sloan Digital Sky Survey (SDSS) surveys, totaling 5000-15,000 clusters. A clear trend of increasing mean redshift toward the cluster centers is found, averaged over each of the four cluster samples. In addition, we find similar but noisier behavior for an independent X-ray sample of 158 clusters lying in the foreground of the current BOSS sky area. By adopting the mass-richness relationships appropriate for each survey, we compare our results with theoretical predictions for each of the four SDSS cluster catalogs. The radial form of this redshift enhancement is well fitted by a richness-to-mass weighted composite Navarro-Frenk-White profile with an effective mass ranging between M{sub 200} {approx} 1.4-1.8 Multiplication-Sign 10{sup 14} M{sub Sun} for the optically detected cluster samples, and M{sub 200} {approx} 5.0 Multiplication-Sign 10{sup 14} M{sub Sun} for the X-ray sample. This lensing detection helps to establish the credibility of these SDSS cluster surveys, and provides a normalization for their respective mass-richness relations. In the context of the upcoming bigBOSS, Subaru Prime Focus Spectrograph, and EUCLID-NISP spectroscopic surveys, this method represents an independent means of deriving the masses of cluster samples for examining the cosmological evolution, and provides a relatively clean consistency check of weak-lensing measurements, free from the systematic limitations of shear calibration.

  12. The Distribution of Barred Galaxies in the Virgo Cluster

    E-Print Network [OSTI]

    Victor Andersen

    1996-03-22T23:59:59.000Z

    A study of the distribution of barred and nonbarred disk galaxies in the Virgo cluster is presented in an attempt to use the frequency and spatial distribution of galaxies with specific morphological features to study the efficiency of various environmental effects on the evolution of disk galaxies in clusters. The velocity distribution of the barred spirals in the Virgo region is clearly different than that of the nonbarred spirals, suggesting that barred spirals are more common in the main condensation of the cluster. A sample cleansed of galaxies not belonging to the main cluster condensation using the subcluster assignments of Binggeli et al. [A&AS, 98, 275 (1993)] bears this out, showing that the radial distribution of barred spirals is more centrally condensed than that of nonbarred spirals. In contrast to the spiral galaxies, the distribution of barred S0 galaxies is statistically indistinguishable from that of nonbarred S0's. Consideration of the level of tidal perturbation due to the cluster mass distribution as compared to that due to individual galaxies suggests that tidal triggering by the cluster mass distribution is the most likely source of the enhanced fraction of barred spirals in the cluster center.

  13. Binding Energy and the Fundamental Plane of Globular Clusters

    E-Print Network [OSTI]

    Dean E. McLaughlin

    2000-02-03T23:59:59.000Z

    A physical description of the fundamental plane of Galactic globular clusters is developed which explains all empirical trends and correlations in a large number of cluster observables and provides a small but complete set of truly independent constraints on theories of cluster formation and evolution in the Milky Way. Within the theoretical framework of single-mass, isotropic King models, it is shown that (1) 39 regular (non--core-collapsed) globulars with measured core velocity dispersions share a common V-band mass-to-light ratio of 1.45 +/- 0.10, and (2) a complete sample of 109 regular globulars reveals a very strong correlation between cluster binding energy and total luminosity, regulated by Galactocentric position: E_b \\propto (L^{2.05} r_{\\rm gc}^{-0.4}). The observational scatter about either of these two constraints can be attributed fully to random measurement errors, making them the defining equations of a fundamental plane for globular clusters. A third, weaker correlation, between total luminosity and the King-model concentration parameter, c, is then related to the (non-random) distribution of globulars on the plane. The equations of the FP are used to derive expressions for any cluster observable in terms of only L, r_{\\rm gc}, and c. Results are obtained for generic King models and applied specifically to the globular cluster system of the Milky Way.

  14. Using the central VAX cluster at ANL

    SciTech Connect (OSTI)

    Caruthers, C.M.; Vote, S.L. [eds.; Lifka, D.A.; Raffenetti, R.C.

    1992-08-01T23:59:59.000Z

    This report is a manual that discusses the following topics on the Central Vax Cluster at ANL: What the Central Vax Cluster is; how the Vax Cluster works; operational policies; getting started; using tapes; printing on the Vax Cluster; developing programs in VMS; using the X window system on the Central Vax Cluster; and using Central Vax Cluster file sharing services.

  15. FT-ICR Study of Precursor Clusters of Single Wall Carbon Nanotubes (SWNTs)

    E-Print Network [OSTI]

    Maruyama, Shigeo

    of metal-doped carbon materials used for macroscopic production of endohedral metallofullerene or SWNTs. Four different sample materials were used in the cluster beam source. Two of them were composite disks with pure carbon clusters. On the other hand, NiCn - from Ni/Co-doped and Ni/Y-doped materials and Co

  16. Computational analysis of microarray gene expression profiles: clustering, classification, and beyond

    E-Print Network [OSTI]

    Dai, Yang

    Computational analysis of microarray gene expression profiles: clustering, classification) the discovery of gene clusters, and (3) the classification of biological samples. In addition, we discuss how inch, and a library of thousands of genes is placed on a single chip. To probe the global gene

  17. Deposition dynamics and chemical properties of size-selected Ir clusters on TiO2

    E-Print Network [OSTI]

    Anderson, Scott L.

    reserved. Keywords: Iridium; Clusters; Titanium oxide; X-ray photoelectron spectroscopy; Low energy ion report a study of Irn/TiO2 samples prepared by size and energy-selected deposition of Irþ n (n ¼ 1, 2, 5 in the zero oxidation state, and there are no significant shifts in Ir 4f binding energy with cluster size

  18. Pinpointing Sheets for the Standard Cross-Cultural Sample: Complete Edition

    E-Print Network [OSTI]

    White, Douglas R.

    2009-01-01T23:59:59.000Z

    7/27/68) Sampling Province 199: Patagonia. Representative ofof Cluster 391: Tehuelche (Patagonia), Sg4:349. Focus: Theoccupied the steppes of Patagonia in Argentina from the Rio

  19. Clusters of Extragalactic Ultra Compact HII Regions

    E-Print Network [OSTI]

    Kelsey E. Johnson; Chip Kobulnicky; Phil Massey; Peter Conti

    2001-07-10T23:59:59.000Z

    We report on the detection of optically thick free-free radio sources in the galaxies M33, NGC 253, and NGC 6946 using data in the literature. We interpret these sources as being young, embedded star birth regions, which are likely to be clusters of ultracompact HII regions. All 35 of the sources presented in this article have positive radio spectral indices alpha>0 suggesting an optically thick thermal bremsstrahlung emission arising in the HII region surrounding hot stars. Energy requirements indicate a range of a several to >500 O7V star equivalents powering each HII region. Assuming a Salpeter IMF, this corresponds to integrated stellar masses of 0.1--60,000 Msun. For roughly half of the sources in our sample, there is no obvious optical counterpart, giving further support for their deeply embedded nature. Their luminosities and radio spectral energy distributions are consistent with HII regions having electron densities from 1500 cm^-3 to 15000 cm^-3 and radii of 1 - 7 pc. We suggest that the less luminous of these sources are extragalactic ultracompact HII region complexes, those of intermediate luminosity are similar to W49 in the Galaxy, while the brightest will be counterparts to 30 Doradus. These objects constitute the lower mass range of extragalactic ``ultradense HII regions'' which we argue are the youngest stages of massive star cluster formation yet observed. This sample is beginning to fill in the continuum of objects between small associations of ultracompact HII regions and the massive extragalactic clusters that may evolve into globular clusters.

  20. Clustering of SZ clusters on a past light-cone: acoustic oscillations and constraints on dark energy

    E-Print Network [OSTI]

    G. Huetsi

    2005-12-07T23:59:59.000Z

    In this paper we study the clustering of SZ-selected galaxy clusters on a past light-cone, particularly paying attention to the possibility of constraining properties of dark energy. The prospects of detecting baryonic features in the cluster power spectrum for a wide and shallow survey like PLANCK, and for an SPT-like narrow and deep survey are discussed. It is demonstrated that these future blank sky SZ surveys will have capability to improve significantly over the recently announced detection of baryonic oscillations based on the SDSS Luminous Red Galaxy (LRG) sample. We carry out parameter estimation using Fisher matrix approach taking into account the anisotropic nature of the power spectrum due to redshift space and cosmological distortions. The clustering signal which is not too sensitive to systematic uncertainties serves as a valuable piece of information that in combination with other sources of data helps in breaking degeneracies between the cosmological parameters.

  1. Structure and kinematics of galaxy clusters I. The redshift catalogue

    E-Print Network [OSTI]

    P. Stein

    1996-01-12T23:59:59.000Z

    An extensive redshift survey has been conducted on a sample of 15 nearby (0.01 < z < 0.05) clusters of galaxies. A total number of 860 redshifts were determined by fitting of emission--lines and/or cross-correlation techniques. Of this sample, 735 galaxies are within 0.2--0.8 Mpc ($H_0$ = 50 km/s/Mpc) of the center of clusters. Approximate morphological types are available for most of the galaxies. A comparison of the present redshifts with published data allows an extensive error analysis. The agreement is excellent with the most modern data, showing a zero point error of 5 km/s and an overall consistency of the measurements and their uncertainties. We estimate our redshifts to have mean random errors around 30 km/s. A population analysis of the clusters will be given in a forthcoming paper.

  2. PHOTOMETRIC PROPERTIES OF THE M33 STAR CLUSTER SYSTEM

    SciTech Connect (OSTI)

    San Roman, Izaskun; Sarajedini, Ata [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611-2055 (United States); Aparicio, Antonio, E-mail: izaskun@astro.ufl.ed, E-mail: ata@astro.ufl.ed, E-mail: antapaj@iac.e [Instituto de Astrofisica de Canarias, Via Lactea s/n. E-38205, La Laguna, Tenerife, Canary Islands (Spain)

    2010-09-10T23:59:59.000Z

    We present a catalog of 2990 extended sources in a 1{sup 0} x 1{sup 0} area centered on M33 using the MegaCam camera on the 3.6 m Canada-France-Hawaii Telescope. The catalog includes 599 new candidate stellar clusters, 204 previously confirmed clusters, 1969 likely background galaxies, and 218 unknown extended objects. We present ugriz integrated magnitudes of the candidates and confirmed star clusters (SCs) as well as the full width at half maximum, ellipticity, and stellarity. Based on the properties of the confirmed SCs, we select a sub-sample of highly probable clusters composed of 246 objects. The integrated photometry of the complete cluster catalog reveals a wide range of colors of -0.4 < (g - r) < 1.5 and -1.0 < (r - i) < 1.0 with no obvious cluster subpopulations. Comparisons with models of simple stellar populations suggest a large range of ages some as old as {approx}10 Gyr. In addition, we find a sequence in the color-color diagrams that deviates from the expected direction of evolution. This feature could be associated with very young clusters (<10{sup 7} yr) possessing significant nebular emission. Analysis of the radial density distribution suggests that the cluster system of M33 has suffered from significant depletion possibly due to interactions with M31. We also detect a gap in the cluster distribution in the color-color diagram at (g - r) {approx_equal} 0.3 and (u - g) {approx_equal} 0.8. This gap could be interpreted as an evolutionary effect. This complete catalog provides promising targets for deep photometry and high-resolution spectroscopy to study the structure and star formation history of M33.

  3. Clustering of Ultraluminous Infrared Galaxies in the Boötes Field

    E-Print Network [OSTI]

    De Alba, Roberto

    2010-07-14T23:59:59.000Z

    of these two samples are nearly indistinguishable, and they are consistent with the clustering of other massive galaxies at these redshifts. Therefore, we conclude that these objects occupy dark-matter haloes of similar mass, on the order of 5 x 1012M...

  4. Topological clusters in SU(2) gluodynamics at finite T and

    E-Print Network [OSTI]

    Topological clusters in SU(2) gluodynamics at finite T and the evidence for KvB calorons E'2005, Trinity College, Dublin July 25 to 30, 2005 #12;Overview Content · Introduction · The SU(2) KvB Caloron · Caloron-like Structures in Monte-Carlo Samples ? · A Stochastic Caloron Model · Summary

  5. Zirconium, barium, lanthanum, and europium abundances in open clusters

    E-Print Network [OSTI]

    Friel, Eileen D.

    We present an analysis of the s-process elements Zr, Ba, and La and the r-process element Eu in a sample of 50 stars in 19 open clusters. Stellar abundances of each element are based on measures of a minimum of two lines ...

  6. IDENTIFICATION Your Sample Box

    E-Print Network [OSTI]

    Liskiewicz, Maciej

    to Virginia Tech Soil Testing Lab, 145 Smyth Hall (MC 0465), 185 Ag Quad Ln, Blacksburg VA 24061, in sturdy, K, Ca, Mg, Zn, Mn, Cu, Fe, B, and soluble salts) NoCharge $16.00 Organic Matter $4.00 $6.00 Fax with soil sample and form; make check or money order payable to "Treasurer, Virginia Tech." COST PER SAMPLE

  7. Sampling system and method

    DOE Patents [OSTI]

    Decker, David L.; Lyles, Brad F.; Purcell, Richard G.; Hershey, Ronald Lee

    2013-04-16T23:59:59.000Z

    The present disclosure provides an apparatus and method for coupling conduit segments together. A first pump obtains a sample and transmits it through a first conduit to a reservoir accessible by a second pump. The second pump further conducts the sample from the reservoir through a second conduit.

  8. Rehabilitation Services Sample Occupations

    E-Print Network [OSTI]

    Ronquist, Fredrik

    /Industries Correction Agencies Drug Treatment Centers Addiction Counselor Advocacy Occupations Art Therapist BehavioralRehabilitation Services Sample Occupations Sample Work Settings Child & Day Care Centers Clinics................................ IIB 29-1000 E4 Careers in Counseling and Human Services .........IIB 21-1010 C7 Careers in Health Care

  9. Constraints on Cluster Formation from Old Globular CLuster Systems

    E-Print Network [OSTI]

    Dean E. McLaughlin

    2000-02-03T23:59:59.000Z

    The properties of old globular cluster systems (GCSs) in galaxy halos offer unique insight into the physical processes that conspire to form any generic star cluster, at any epoch. Presented here is a summary of the information obtained from (1) the specific frequencies (total populations) and spatial structures (density vs. galactocentric radius) of GCSs in early-type galaxies, as they relate to the efficiency (or probability) of bound cluster formation, and (2) the fundamental role of a scaling between cluster mass and energy among Galactic globulars in setting their other structural correlations, and the possible implications for star formation efficiency as a function of mass in gaseous protoclusters.

  10. Intergalactic stars in the Fornax Cluster

    E-Print Network [OSTI]

    Tom Theuns; S. J. Warren

    1996-09-10T23:59:59.000Z

    We have identified ten candidate intergalactic planetary nebulae in the Fornax galaxy cluster. These objects were found during observations in 1992 and 1993 in three fields chosen well away from any Fornax galaxy at 15 arcmin, 30 arcmin, and 45 arcmin from the centre of Fornax. We used the usual method of blinking images taken in a narrow OIII filter, with images taken in an adjacent broad filter. The measured fluxes in the narrow, broad, and I bands are consistent with these unresolved objects being planetary nebulae immersed in an intergalactic population of stars. Such a population is expected to arise as a consequence of tidal encounters between galaxies, and our findings strengthen the case for the existence of such tidal debris. The confirmation of some or all of these ten candidates as planetary nebulae would imply that intergalactic stars constitute a substantial fraction of all the stars in Fornax, up to an estimated 40 per cent. Intergalactic planetary nebulae could prove useful in probing the underlying cluster potential, since they would be far more abundant than galaxies. We discuss possible contamination of the sample by emission-line galaxies, but conclude that planetary nebulae is the most likely identification for the detected objects. keywords: intergalactic medium-- galaxies: interactions -- planetary nebulae: general -- clusters: individual: Fornax

  11. Graph partitioning advance clustering technique

    E-Print Network [OSTI]

    Madhulatha, T Soni

    2012-01-01T23:59:59.000Z

    Clustering is a common technique for statistical data analysis, Clustering is the process of grouping the data into classes or clusters so that objects within a cluster have high similarity in comparison to one another, but are very dissimilar to objects in other clusters. Dissimilarities are assessed based on the attribute values describing the objects. Often, distance measures are used. Clustering is an unsupervised learning technique, where interesting patterns and structures can be found directly from very large data sets with little or none of the background knowledge. This paper also considers the partitioning of m-dimensional lattice graphs using Fiedler's approach, which requires the determination of the eigenvector belonging to the second smallest Eigenvalue of the Laplacian with K-means partitioning algorithm.

  12. The Cluster SZ -- Mass Correlation

    E-Print Network [OSTI]

    Christopher A. Metzler

    1998-12-16T23:59:59.000Z

    N-body + hydrodynamic simulations of galaxy clusters are used to demonstrate a correlation between galaxy cluster mass and the strength of the Sunyaev-Zel'dovich (SZ) effect induced by the cluster. The intrinsic scatter in the correlaton is larger than seen in the cluster mass -- X-ray temperature correlation, but smaller than seen in the correlation between mass (or temperature) and X-ray luminosity, as expected. Using the convergence to self-similarity of cluster structure at larger radii, a simple area-averaged SZ value derived from mock SZ maps also correlates well with mass; the intrinsic scatter in this correlation is comparable to that seen in simulations for the mass -- temperature correlation. Such a relation may prove a powerful tool for estimating cluster masses at higher redshifts.

  13. Cluster structures in Oxygen isotopes

    E-Print Network [OSTI]

    N. Furutachi; M. kimura; A. Doté; Y. Kanada-En'yo; S. oryu

    2007-06-01T23:59:59.000Z

    Cluster structure of 16O,18O and 20O is investigated by the antisymmettrized molecular dynamics (AMD) plus generator coordinate method (GCM). We have found the K^{\\pi}=0$_2^+$ and 0$_1^-$ rotational bands of 18O that have the prominent 14C+\\alpha cluster structure. Clustering systematics becomes richer in 20O. We suggest the K^{\\pi}=0$_2^+$ band that is the mixture of the 12C+\\alpha+4n and 14C+6He cluster structures, and the K^{\\pi}=0$_1^-$ band that has the 14C+6He cluster structure. The K^{\\pi}=0$_3^+$ and 0$_2^-$ bands that have the prominent 16C+\\alpha cluster structure are also found.

  14. A Serendipitous Deep Cluster Survey from ROSAT--PSPC pointed observations

    E-Print Network [OSTI]

    P. Rosati

    1995-09-09T23:59:59.000Z

    We present a deep X-ray selected sample of galaxy clusters which has been created from a serendipitous search in ROSAT-PSPC deep pointed observations at high galactic latitude. This survey, hereafter known as the ROSAT Deep Cluster Survey (RDCS), is being carried out utilizing a wavelet-based detection algorithm which, unlike other detection methods, is not biased against extended, low surface brightness sources. It is a flux-diameter limited sample that extends the X-ray flux limit of previous cluster surveys by more than one order of magnitude ($F_X \\ge 1\\cdot 10^{-14}\\rm erg\\, cm^{-2}s^{-1}$). The first results of the on-going optical follow-up program indicate a high success rate of identification. At the present, 38 clusters out of 80 candidates have been identified on a 26 deg$^2$ surveyed area. Recently measured redshifts confirm the nature of these systems as low-moderate redshift groups ($z\\simeq 0.2-0.3$) and intermediate to high redshift clusters ($z\\simeq 0.4-0.7$). We show X-ray and optical images of several clusters identified to date, discuss the X-ray properties of the sample and present preliminary results on the redshift distribution. The final sample will include $\\sim 100$ clusters covering and area of $\\sim 40$ deg$^2$.

  15. Heating and cooling in the Perseus cluster core

    E-Print Network [OSTI]

    A. C. Fabian; J. S. Sanders

    2006-12-15T23:59:59.000Z

    It is well known that the radiative cooling time of the hot X-ray emitting gas in the cores of most clusters of galaxies is less than 10^10 yr. In many clusters the gas temperature also drops towards the centre. If we draw a causal connection between these two properties then we infer the presence of a cooling flow onto the central galaxy. High spectral resolution XMM-Newton data and high spatial resolution Chandra data, show however a lack of X-ray emitting gas below about one third of the cluster virial temperature. The explanation is that some form of heating balances cooling. The smoothness and similarity of the cooling time profiles and the flatness of the required heating profiles all indicate that we must seek a relatively gentle, quasi-continuous (on timescales heat source. The likely such source is the central black hole and its powerful jets which create bubble-like cavities in the inner hot gas. We briefly review the general heating and cooling statistics in an X-ray bright sample of cluster before we discuss the detailed situation in the Perseus cluster, the X-ray brightest cluster in the Sky.

  16. Cosmological Constraints from the SDSS maxBCG Cluster Catalog

    SciTech Connect (OSTI)

    Rozo, Eduardo; /CCAPP; Wechsler, Risa H.; /KIPAC, Menlo Park /SLAC; Rykoff, Eli S.; /UC, Santa Barbara; Annis, James T.; /Fermilab; Becker, Matthew R.; /Chicago U. /KICP, Chicago; Evrard, August E.; /Michigan U. /Michigan U., MCTP; Frieman, Joshua A.; /Fermilab /KICP, Chicago /Chicago U.; Hansen, Sarah M.; /UC, Santa Cruz; Hao, Jia; /Michigan U.; Johnston, David E.; /Northwestern U.; Koester, Benjamin P.; /KICP, Chicago /Chicago U.; McKay, Timothy A.; /Michigan U. /Michigan U., MCTP; Sheldon, Erin S.; /Brookhaven; Weinberg, David H.; /CCAPP /Ohio State U.

    2009-08-03T23:59:59.000Z

    We use the abundance and weak lensing mass measurements of the SDSS maxBCG cluster catalog to simultaneously constrain cosmology and the richness-mass relation of the clusters. Assuming a flat {Lambda}CDM cosmology, we find {sigma}{sub 8}({Omega}{sub m}/0.25){sup 0.41} = 0.832 {+-} 0.033 after marginalization over all systematics. In common with previous studies, our error budget is dominated by systematic uncertainties, the primary two being the absolute mass scale of the weak lensing masses of the maxBCG clusters, and uncertainty in the scatter of the richness-mass relation. Our constraints are fully consistent with the WMAP five-year data, and in a joint analysis we find {sigma}{sub 8} = 0.807 {+-} 0.020 and {Omega}{sub m} = 0.265 {+-} 0.016, an improvement of nearly a factor of two relative to WMAP5 alone. Our results are also in excellent agreement with and comparable in precision to the latest cosmological constraints from X-ray cluster abundances. The remarkable consistency among these results demonstrates that cluster abundance constraints are not only tight but also robust, and highlight the power of optically-selected cluster samples to produce precision constraints on cosmological parameters.

  17. Waste classification sampling plan

    SciTech Connect (OSTI)

    Landsman, S.D.

    1998-05-27T23:59:59.000Z

    The purpose of this sampling is to explain the method used to collect and analyze data necessary to verify and/or determine the radionuclide content of the B-Cell decontamination and decommissioning waste stream so that the correct waste classification for the waste stream can be made, and to collect samples for studies of decontamination methods that could be used to remove fixed contamination present on the waste. The scope of this plan is to establish the technical basis for collecting samples and compiling quantitative data on the radioactive constituents present in waste generated during deactivation activities in B-Cell. Sampling and radioisotopic analysis will be performed on the fixed layers of contamination present on structural material and internal surfaces of process piping and tanks. In addition, dose rate measurements on existing waste material will be performed to determine the fraction of dose rate attributable to both removable and fixed contamination. Samples will also be collected to support studies of decontamination methods that are effective in removing the fixed contamination present on the waste. Sampling performed under this plan will meet criteria established in BNF-2596, Data Quality Objectives for the B-Cell Waste Stream Classification Sampling, J. M. Barnett, May 1998.

  18. Globular Clusters in Dwarf Galaxies

    E-Print Network [OSTI]

    Bryan W. Miller

    2006-06-02T23:59:59.000Z

    Recent work on globular cluster systems in dwarf galaxies outside the Local Group is reviewed. Recent large imaging surveys with the Hubble Space Telescope and follow-up spectroscopy with 8-m class telescopes now allow us to compare the properties of massive star clusters in a wide range of galaxy types and environments. This body of work provides important constraints for theories of galaxy and star cluster formation and evolution.

  19. CAIRNS: The Cluster And Infall Region Nearby Survey I. Redshifts and Mass Profiles

    E-Print Network [OSTI]

    K. Rines; M. J. Geller; M. J. Kurtz; A. Diaferio

    2003-06-25T23:59:59.000Z

    The CAIRNS (Cluster And Infall Region Nearby Survey) project is a spectroscopic survey of the infall regions surrounding eight nearby, rich, X-ray luminous clusters of galaxies. We collect 15665 redshifts (3471 new or remeasured) within \\sim 5-10 Mpc of the centers of the clusters, making it the largest study of the infall regions of clusters. We determine cluster membership and the mass profiles of the clusters based on the phase space distribution of the galaxies. All of the clusters display decreasing velocity dispersion profiles. The mass profiles are fit well by functional forms based on numerical simulations but exclude an isothermal sphere. Specifically, NFW and Hernquist models provide good descriptions of cluster mass profiles to their turnaround radii. Our sample shows that the predicted infall pattern is ubiquitous in rich, X-ray luminous clusters over a large mass range. The caustic mass estimates are in excellent agreement with independent X-ray estimates at small radii and with virial estimates at intermediate radii. The mean ratio of the caustic mass to the X-ray mass is 1.03\\pm0.11 and the mean ratio of the caustic mass to the virial mass (when corrected for the surface pressure term) is 0.93\\pm0.07. We further demonstrate that the caustic technique provides reasonable mass estimates even in merging clusters.

  20. From clusters to clouds | EMSL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    experimental data to quantum chemical calculations of cluster dissociation thermodynamics and determined that loss of either an ammonia molecule or an ammonium bisulfate...

  1. Are Cluster Dwarfs Recycled Galaxies?

    E-Print Network [OSTI]

    Christopher J. Conselice

    2003-12-12T23:59:59.000Z

    Although cluster dwarf galaxies are often neglected due to their faintness, recent observations demonstrate that they are critical for understanding the physical processes behind galaxy and cluster formation. Dwarfs are the most common galaxy type and are particularly abundant in clusters. Recent observational results suggest that dwarfs in dense environments do not all form early in the universe, as expected from hierarchical structure formation models. Many of these systems appear to be younger and more metal rich than dwarfs in lower density areas, suggesting they are possibly created by a tidal process. Several general galaxy cluster observations, including steep luminosity functions and the origin of intracluster light, are natural outcomes of these processes.

  2. YOUNG RADIO PULSARS IN GALACTIC GLOBULAR CLUSTERS

    SciTech Connect (OSTI)

    Boyles, J.; Lorimer, D. R. [Department of Physics, 210 Hodges Hall, West Virginia University, Morgantown, WV 26506 (United States); Turk, P. J.; Mnatsakanov, R. [Department of Statistics, 423 Hodges Hall, West Virginia University, Morgantown, WV 26506 (United States); Lynch, R. S. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904 (United States); Ransom, S. M. [National Radio Astronomy Observatory, 520 Edgemont Rd, Charlottesville, VA (United States); Freire, P. C. [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel D-53121, Bonn (Germany); Belczynski, K. [Astronomical Observatory, University of Warsaw, AL Ujazdowskie 4,00-478, Warsaw (Poland)

    2011-11-20T23:59:59.000Z

    Currently three isolated radio pulsars and one binary radio pulsar with no evidence of any previous recycling are known in 97 surveyed Galactic globular clusters (GCs). As pointed out by Lyne et al., the presence of these pulsars cannot be explained by core-collapse supernovae, as commonly assumed for their counterparts in the Galactic disk. We apply a Bayesian analysis to the results from surveys for radio pulsars in GCs and find the number of potentially observable non-recycled radio pulsars present in all clusters to be <3600. Accounting for beaming and retention considerations, the implied birthrate for any formation scenario for all 97 clusters is <0.25 pulsars century{sup -1} assuming a Maxwellian distribution of velocities with a dispersion of 10 km s{sup -1}. The implied birthrates for higher velocity dispersions are substantially higher than inferred for such pulsars in the Galactic disk. This suggests that the velocity dispersion of young pulsars in GCs is significantly lower than those of disk pulsars. These numbers may be substantial overestimates due to the fact that the currently known sample of young pulsars is observed only in metal-rich clusters. We propose that young pulsars may only be formed in GCs with metallicities with log[Fe/H] > - 0.6. In this case, the potentially observable population of such young pulsars is 447{sup +1420}{sub -399} (the error bars give a 95% confidence interval) and their birthrate is 0.012{sup +0.037}{sub -0.010} pulsars century{sup -1}. The most likely creation scenario to explain these pulsars is the electron capture supernova of an OMgNe white dwarf.

  3. Cluster Compatibility Mode

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisiting the TWPSuccessAlamosCharacterization2Climate, Ocean and SeaClotCluster

  4. Cluster Compatibility Mode

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisiting the TWPSuccessAlamosCharacterization2Climate, Ocean and SeaClotClusterHopper

  5. Sample Changes and Issues

    Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]

    EIA-914 Survey and HPDI. Figure 2 shows how this could change apparent production. The blue line shows the reported sample production as it would normally be reported under the...

  6. Water Sample Concentrator

    ScienceCinema (OSTI)

    Idaho National Laboratory

    2010-01-08T23:59:59.000Z

    Automated portable device that concentrates and packages a sample of suspected contaminated water for safe, efficient transport to a qualified analytical laboratory. This technology will help safeguard against pathogen contamination or chemical and biolog

  7. Dissolution actuated sample container

    DOE Patents [OSTI]

    Nance, Thomas A.; McCoy, Frank T.

    2013-03-26T23:59:59.000Z

    A sample collection vial and process of using a vial is provided. The sample collection vial has an opening secured by a dissolvable plug. When dissolved, liquids may enter into the interior of the collection vial passing along one or more edges of a dissolvable blocking member. As the blocking member is dissolved, a spring actuated closure is directed towards the opening of the vial which, when engaged, secures the vial contents against loss or contamination.

  8. SAMPLING AND ANALYSIS PROTOCOLS

    SciTech Connect (OSTI)

    Jannik, T; P Fledderman, P

    2007-02-09T23:59:59.000Z

    Radiological sampling and analyses are performed to collect data for a variety of specific reasons covering a wide range of projects. These activities include: Effluent monitoring; Environmental surveillance; Emergency response; Routine ambient monitoring; Background assessments; Nuclear license termination; Remediation; Deactivation and decommissioning (D&D); and Waste management. In this chapter, effluent monitoring and environmental surveillance programs at nuclear operating facilities and radiological sampling and analysis plans for remediation and D&D activities will be discussed.

  9. TANK 5 SAMPLING

    SciTech Connect (OSTI)

    Vrettos, N; William Cheng, W; Thomas Nance, T

    2007-11-26T23:59:59.000Z

    Tank 5 at the Savannah River Site has been used to store high level waste and is currently undergoing waste removal processes in preparation for tank closure. Samples were taken from two locations to determine the contents in support of Documented Safety Analysis (DSA) development for chemical cleaning. These samples were obtained through the use of the Drop Core Sampler and the Snowbank Sampler developed by the Engineered Equipment & Systems (EES) group of the Savannah River National Laboratory (SRNL).

  10. Atomically precise (catalytic) particles synthesized by a novel cluster deposition instrument

    SciTech Connect (OSTI)

    Yin, C.; Tyo, E. [Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States)] [Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Kuchta, K. [Extrel CMS, LLC, 575 Epsilon Dr. Suite 2, Pittsburgh, Pennsylvania 15238-2838 (United States)] [Extrel CMS, LLC, 575 Epsilon Dr. Suite 2, Pittsburgh, Pennsylvania 15238-2838 (United States); Issendorff, B. von [Physikalisches Institut, Universität Freiburg, Stefan-Meier Str. 21, D-79104 Freiburg (Germany)] [Physikalisches Institut, Universität Freiburg, Stefan-Meier Str. 21, D-79104 Freiburg (Germany); Vajda, S., E-mail: vajda@anl.gov [Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Nanoscience and Technology Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Institute for Molecular Engineering, The University of Chicago, 5747 South Ellis Avenue, Chicago, Illinois 60637 (United States); Department of Chemical and Environmental Engineering, School of Engineering and Applied Science, Yale University, 9 Hillhouse Avenue, New Haven, Connecticut 06520 (United States)

    2014-05-07T23:59:59.000Z

    We report a new high vacuum instrument which is dedicated to the preparation of well-defined clusters supported on model and technologically relevant supports for catalytic and materials investigations. The instrument is based on deposition of size selected metallic cluster ions that are produced by a high flux magnetron cluster source. The throughput of the apparatus is maximized by collecting and focusing ions utilizing a conical octupole ion guide and a linear ion guide. The size selection is achieved by a quadrupole mass filter. The new design of the sample holder provides for the preparation of multiple samples on supports of various sizes and shapes in one session. After cluster deposition onto the support of interest, samples will be taken out of the chamber for a variety of testing and characterization.

  11. Liquid sampling system

    DOE Patents [OSTI]

    Larson, L.L.

    1984-09-17T23:59:59.000Z

    A conduit extends from a reservoir through a sampling station and back to the reservoir in a closed loop. A jet ejector in the conduit establishes suction for withdrawing liquid from the reservoir. The conduit has a self-healing septum therein upstream of the jet ejector for receiving one end of a double-ended cannula, the other end of which is received in a serum bottle for sample collection. Gas is introduced into the conduit at a gas bleed between the sample collection bottle and the reservoir. The jet ejector evacuates gas from the conduit and the bottle and aspirates a column of liquid from the reservoir at a high rate. When the withdrawn liquid reaches the jet ejector the rate of flow therethrough reduces substantially and the gas bleed increases the pressure in the conduit for driving liquid into the sample bottle, the gas bleed forming a column of gas behind the withdrawn liquid column and interrupting the withdrawal of liquid from the reservoir. In the case of hazardous and toxic liquids, the sample bottle and the jet ejector may be isolated from the reservoir and may be further isolated from a control station containing remote manipulation means for the sample bottle and control valves for the jet ejector and gas bleed. 5 figs.

  12. Liquid sampling system

    DOE Patents [OSTI]

    Larson, Loren L. (Idaho Falls, ID)

    1987-01-01T23:59:59.000Z

    A conduit extends from a reservoir through a sampling station and back to the reservoir in a closed loop. A jet ejector in the conduit establishes suction for withdrawing liquid from the reservoir. The conduit has a self-healing septum therein upstream of the jet ejector for receiving one end of a double-ended cannula, the other end of which is received in a serum bottle for sample collection. Gas is introduced into the conduit at a gas bleed between the sample collection bottle and the reservoir. The jet ejector evacuates gas from the conduit and the bottle and aspirates a column of liquid from the reservoir at a high rate. When the withdrawn liquid reaches the jet ejector the rate of flow therethrough reduces substantially and the gas bleed increases the pressure in the conduit for driving liquid into the sample bottle, the gas bleed forming a column of gas behind the withdrawn liquid column and interrupting the withdrawal of liquid from the reservoir. In the case of hazardous and toxic liquids, the sample bottle and the jet ejector may be isolated from the reservoir and may be further isolated from a control station containing remote manipulation means for the sample bottle and control valves for the jet ejector and gas bleed.

  13. PreparationSampleGuide:StartQuickISX Sample Preparation Guide

    E-Print Network [OSTI]

    straining the sample through a 70 micron nylon mesh strainer. If sample aggregation is a problem, we suggest

  14. Comparative clustering analysis of variable stars in the Hipparcos, OGLE Large Magellanic Cloud and CoRoT exoplanet databases

    E-Print Network [OSTI]

    Sarro, L M; Aerts, C; López, M

    2009-01-01T23:59:59.000Z

    Context. Discovery of new variability classes in large surveys using multivariate statistics techniques such as clustering, relies heavily on the correct understanding of the distribution of known classes as point processes in parameter space. Aims. Our objective is to analyze the correspondence between the classical stellar variability types and the clusters found in the distribution of light curve parameters and colour indices of stars in the CoRoT exoplanet sample. The final aim is to help in the identification on new types of variability by first identifying the well known variables in the CoRoT sample. Methods. We apply unsupervised classification algorithms to identify clusters of variable stars from modes of the probability density distribution. We use reference variability databases (Hipparcos and OGLE) as a framework to calibrate the clustering methodology. Furthermore, we use the results from supervised classification methods to interpret the resulting clusters. Results.We interpret the clusters in ...

  15. Incremental Hierarchical Clustering of Text Documents

    E-Print Network [OSTI]

    Gordon, Geoffrey J.

    distribution is demonstrated. 1 Introduction Document clustering is an effective tool to manage informationIncremental Hierarchical Clustering of Text Documents by Nachiketa Sahoo Adviser: Jamie Callan May 5, 2006 Abstract Incremental hierarchical text document clustering algorithms are important

  16. Fluid sampling system

    DOE Patents [OSTI]

    Houck, E.D.

    1994-10-11T23:59:59.000Z

    An fluid sampling system allows sampling of radioactive liquid without spillage. A feed tank is connected to a liquid transfer jet powered by a pumping chamber pressurized by compressed air. The liquid is pumped upwardly into a sampling jet of a venturi design having a lumen with an inlet, an outlet, a constricted middle portion, and a port located above the constricted middle portion. The liquid is passed under pressure through the constricted portion causing its velocity to increase and its pressure to be decreased, thereby preventing liquid from escaping. A septum sealing the port can be pierced by a two pointed hollow needle leading into a sample bottle also sealed by a pierceable septum affixed to one end. The bottle is evacuated by flow through the sample jet, cyclic variation in the sampler jet pressure periodically leaves the evacuated bottle with lower pressure than that of the port, thus causing solution to pass into the bottle. The remaining solution in the system is returned to the feed tank via a holding tank. 4 figs.

  17. Fluid sampling system

    DOE Patents [OSTI]

    Houck, Edward D. (Idaho Falls, ID)

    1994-01-01T23:59:59.000Z

    An fluid sampling system allows sampling of radioactive liquid without spillage. A feed tank is connected to a liquid transfer jet powered by a pumping chamber pressurized by compressed air. The liquid is pumped upwardly into a sampling jet of a venturi design having a lumen with an inlet, an outlet, a constricted middle portion, and a port located above the constricted middle portion. The liquid is passed under pressure through the constricted portion causing its velocity to increase and its pressure to decreased, thereby preventing liquid from escaping. A septum sealing the port can be pierced by a two pointed hollow needle leading into a sample bottle also sealed by a pierceable septum affixed to one end. The bottle is evacuated by flow through the sample jet, cyclic variation in the sampler jet pressure periodically leaves the evacuated bottle with lower pressure than that of the port, thus causing solution to pass into the bottle. The remaining solution in the system is returned to the feed tank via a holding tank.

  18. Relative Ages of Globular Clusters

    E-Print Network [OSTI]

    Thomas H. Puzia

    2002-10-18T23:59:59.000Z

    Ages of extragalactic globular clusters can provide valuable insights into the formation and evolution of galaxies. In this contribution the photometric methods of age dating old globular cluster systems are summarised. The spectroscopic approach is reviewed with an emphasis of the right choice of age diagnostics. We present a new method of quantifying the relatively best age-sensitive spectroscopic index given the quality of a data set and a certain theoretical stellar synthesis model. The relatively best diagnostic plot is constructed from the set of Lick indices and used to age date globular clusters in several early-type galaxies which are part of a large spectroscopic survey of extragalactic globular cluster systems. We find that, independently of host galaxy, metal-poor ([Fe/H] 8 Gyr) and coeval. Metal-rich clusters show a wide range of ages from ~15 down to a few Gyr.

  19. Viscous sludge sample collector

    DOE Patents [OSTI]

    Beitel, George A [Richland, WA

    1983-01-01T23:59:59.000Z

    A vertical core sample collection system for viscous sludge. A sample tube's upper end has a flange and is attached to a piston. The tube and piston are located in the upper end of a bore in a housing. The bore's lower end leads outside the housing and has an inwardly extending rim. Compressed gas, from a storage cylinder, is quickly introduced into the bore's upper end to rapidly accelerate the piston and tube down the bore. The lower end of the tube has a high sludge entering velocity to obtain a full-length sludge sample without disturbing strata detail. The tube's downward motion is stopped when its upper end flange impacts against the bore's lower end inwardly extending rim.

  20. Experimental Scattershot Boson Sampling

    E-Print Network [OSTI]

    Marco Bentivegna; Nicolò Spagnolo; Chiara Vitelli; Fulvio Flamini; Niko Viggianiello; Ludovico Latmiral; Paolo Mataloni; Daniel J. Brod; Ernesto F. Galvão; Andrea Crespi; Roberta Ramponi; Roberto Osellame; Fabio Sciarrino

    2015-05-14T23:59:59.000Z

    Boson Sampling is a computational task strongly believed to be hard for classical computers, but efficiently solvable by orchestrated bosonic interference in a specialised quantum computer. Current experimental schemes, however, are still insufficient for a convincing demonstration of the advantage of quantum over classical computation. A new variation of this task, Scattershot Boson Sampling, leads to an exponential increase in speed of the quantum device, using a larger number of photon sources based on parametric downconversion. This is achieved by having multiple heralded single photons being sent, shot by shot, into different random input ports of the interferometer. Here we report the first Scattershot Boson Sampling experiments, where six different photon-pair sources are coupled to integrated photonic circuits. We employ recently proposed statistical tools to analyse our experimental data, providing strong evidence that our photonic quantum simulator works as expected. This approach represents an important leap toward a convincing experimental demonstration of the quantum computational supremacy.

  1. Additive Manufacturing Cluster Strategy | ornl.gov

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Additive Manufacturing Cluster Strategy SHARE Additive Manufacturing Cluster Strategy As the nation's premier research laboratory, ORNL is one of the world's most capable resources...

  2. Fragmentation Energetics of Clusters Relevant to Atmospheric...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of Clusters Relevant to Atmospheric New Particle Formation. Fragmentation Energetics of Clusters Relevant to Atmospheric New Particle Formation. Abstract: The exact mechanisms by...

  3. Blue Straggler Stars in Galactic Open Clusters and the Simple Stellar Population Model

    E-Print Network [OSTI]

    Y. Xin; L. Deng; Z. Han

    2006-09-27T23:59:59.000Z

    Blue straggler stars present as secure members in the Galactic open clusters form a major challenge to the conventional picture of evolutionary population synthesis based on the stellar evolution theory of single stars, as illustrated in our previous work. Expansion of our sample in the current work to include younger age clusters provides a larger data base to expose the question raised for the simple stellar population model. The working sample now includes 97 Galactic open clusters of ages ranging from 0.1 to several Gyrs. The contributions of blue straggler stars to the integrated light of the host clusters are calculated on an individual cluster base. A data base of observational constrained simple stellar population model is made which has a larger age coverage than our previous work. It is shown in this work that the general existence of blue stragglers in star clusters of our sample dramatically altered the predictions of convectional stellar population model in terms of spectral energy distribution. The integrated spectral energy distributions of the synthetic spectra of the clusters are enhanced towards shorter wavelengths, therefore the results of the present work will cast new lights in understanding the properties of stellar populations.

  4. Substructure in clusters containing wide-angle tailed radio galaxies. I. New redshifts

    E-Print Network [OSTI]

    Jason Pinkney; Jack O. Burns; Michael J. Ledlow; Percy L. Gomez; John M. Hill

    2000-11-08T23:59:59.000Z

    We present new redshifts and positions for 635 galaxies in nine rich clusters containing Wide-Angle Tailed (WAT) radio galaxies. Combined with existing data, we now have a sample of 18 WAT-containing clusters with more than 10 redshifts. This sample contains a substantial portion of the WAT clusters in the VLA 20 cm survey of Abell clusters, including 75% of WAT clusters in the complete survey (z0.09. It is a representative sample which should not contain biases other than selection by radio morphology. We graphically present the new data using histograms and sky maps. A semi-automated procedure is used to search for emission lines in the spectra in order to add and verify galaxy redshifts. We find that the average apparent fraction of emission line galaxies is about 9% in both the clusters and the field. We investigate the magnitude completeness of our redshift surveys with CCD data for a test case, Abell 690. This case indicates that our galaxy target lists are deeper than the detection limit of a typical MX exposure, and they are 82% complete down to R=19.0. The importance of the uniformity of the placement of fibers on targets is posited, and we evaluate this in our datasets. We find some cases of non-uniformities which may influence dynamical analyses. A second paper will use this database to look for correlations between the WAT radio morphology and the cluster's dynamical state.

  5. Weak-strong clustering transition in renewing compressible flows

    E-Print Network [OSTI]

    Ajinkya Dhanagare; Stefano Musacchio; Dario Vincenzi

    2014-11-01T23:59:59.000Z

    We investigate the statistical properties of Lagrangian tracers transported by a time-correlated compressible renewing flow. We show that the preferential sampling of the phase space performed by tracers yields significant differences between the Lagrangian statistics and its Eulerian counterpart. In particular, the effective compressibility experienced by tracers has a non-trivial dependence on the time correlation of the flow. We examine the consequence of this phenomenon on the clustering of tracers, focusing on the transition from the weak- to the strong-clustering regime. We find that the critical compressibility at which the transition occurs is minimum when the time correlation of the flow is of the order of the typical eddy turnover time. Further, we demonstrate that the clustering properties in time-correlated compressible flows are non-universal and are strongly influenced by the spatio-temporal structure of the velocity field.

  6. Weak-strong clustering transition in renewing compressible flows

    E-Print Network [OSTI]

    Dhanagare, Ajinkya; Vincenzi, Dario

    2014-01-01T23:59:59.000Z

    We investigate the statistical properties of Lagrangian tracers transported by a time-correlated compressible renewing flow. We show that the preferential sampling of the phase space performed by tracers yields significant differences between the Lagrangian statistics and its Eulerian counterpart. In particular, the effective compressibility experienced by tracers has a non-trivial dependence on the time correlation of the flow. We examine the consequence of this phenomenon on the clustering of tracers, focusing on the transition from the weak- to the strong-clustering regime. We find that the critical compressibility at which the transition occurs is minimum when the time correlation of the flow is of the order of the typical eddy turnover time. Further, we demonstrate that the clustering properties in time-correlated compressible flows are non-universal and are strongly influenced by the spatio-temporal structure of the velocity field.

  7. Age determination of 15 old to intermediate-age small Magellanic cloud star clusters

    SciTech Connect (OSTI)

    Parisi, M. C.; Clariá, J. J.; Piatti, A. E. [Observatorio Astronómico, Universidad Nacional de Córdoba, Laprida 854, Córdoba, CP 5000 (Argentina); Geisler, D.; Leiton, R. [Departamento de Astronomía, Universidad de Concepción, Casilla 160-C, Concepción (Chile); Carraro, G. [European Southern Observatory, Casilla 19001, Santiago de Chile (Chile); Costa, E. [Universidad de Chile, Casilla 36-D, Santiago de Chile (Chile); Grocholski, A. J. [Department of Physics and Astronomy, Louisiana State University, 202 Nicholson Hall, Tower Drive, Baton Rouge, LA 70803-4001 (United States); Sarajedini, A., E-mail: celeste@oac.uncor.edu, E-mail: claria@oac.uncor.edu, E-mail: andres@oac.uncor.edu, E-mail: dgeisler@astro-udec.cl, E-mail: roger.leiton@astro-udec.cl, E-mail: gcarraro@eso.org, E-mail: costa@das.uchile.cl, E-mail: grocholski@phys.lsu.edu, E-mail: ata@astro.ufl.edu [Department of Astronomy, University of Florida, P.O. Box 112055, Gainesville, FL 32611 (United States)

    2014-04-01T23:59:59.000Z

    We present color-magnitude diagrams in the V and I bands for 15 star clusters in the Small Magellanic Cloud (SMC) based on data taken with the Very Large Telescope (VLT, Chile). We selected these clusters from our previous work, wherein we derived cluster radial velocities and metallicities from calcium II infrared triplet (CaT) spectra also taken with the VLT. We discovered that the ages of six of our clusters have been appreciably underestimated by previous studies, which used comparatively small telescopes, graphically illustrating the need for large apertures to obtain reliable ages of old and intermediate-age SMC star clusters. In particular, three of these clusters, L4, L6, and L110, turn out to be among the oldest SMC clusters known, with ages of 7.9 ± 1.1, 8.7 ± 1.2, and 7.6 ± 1.0 Gyr, respectively, helping to fill a possible 'SMC cluster age gap'. Using the current ages and metallicities from Parisi et al., we analyze the age distribution, age gradient, and age-metallicity relation (AMR) of a sample of SMC clusters measured homogeneously. There is a suggestion of bimodality in the age distribution but it does not show a constant slope for the first 4 Gyr, and we find no evidence for an age gradient. Due to the improved ages of our cluster sample, we find that our AMR is now better represented in the intermediate/old period than we had derived in Parisi et al., where we simply took ages available in the literature. Additionally, clusters younger than ?4 Gyr now show better agreement with the bursting model of Pagel and Tautvaišien?, but we confirm that this model is not a good representation of the AMR during the intermediate/old period. A more complicated model is needed to explain the SMC chemical evolution in that period.

  8. DEXA'11, Toulouse, France, 31.08.2011 Sampling National Deep Web

    E-Print Network [OSTI]

    Hammerton, James

    DEXA'11, Toulouse, France, 31.08.2011 Sampling National Deep Web Denis Shestakov, fname-IP cluster random sampling Results Conclusions #12;Background Deep Web: web content behind search, the science and practice of deep web crawling is in its infancy" (in 'Web crawling', Olston&Najork, 2010) #12

  9. Modelling dynamics of samples exposed to free-electron-laser radiation with Boltzmann equations

    E-Print Network [OSTI]

    Beata Ziaja; Antonio R. B. de Castro; Edgar Weckert; Thomas Moeller

    2005-12-20T23:59:59.000Z

    We apply Boltzmann equations for modelling the radiation damage in samples irradiated by photons from free electron laser (FEL). We test this method in a study case of a spherically symmetric xenon cluster irradiated with VUV FEL photons. The results obtained demonstrate the potential of the Boltzmann method for describing the complex and non-equilibrium dynamics of samples exposed to FEL radiation.

  10. Analyzing geographic clustered response

    SciTech Connect (OSTI)

    Merrill, D.W.; Selvin, S.; Mohr, M.S.

    1991-08-01T23:59:59.000Z

    In the study of geographic disease clusters, an alternative to traditional methods based on rates is to analyze case locations on a transformed map in which population density is everywhere equal. Although the analyst's task is thereby simplified, the specification of the density equalizing map projection (DEMP) itself is not simple and continues to be the subject of considerable research. Here a new DEMP algorithm is described, which avoids some of the difficulties of earlier approaches. The new algorithm (a) avoids illegal overlapping of transformed polygons; (b) finds the unique solution that minimizes map distortion; (c) provides constant magnification over each map polygon; (d) defines a continuous transformation over the entire map domain; (e) defines an inverse transformation; (f) can accept optional constraints such as fixed boundaries; and (g) can use commercially supported minimization software. Work is continuing to improve computing efficiency and improve the algorithm. 21 refs., 15 figs., 2 tabs.

  11. Environmental Science: Sample Pathway

    E-Print Network [OSTI]

    Goldberg, Bennett

    Environmental Science: Sample Pathway Semester I Semester II Freshman Year CGS Core CGS Core GE 100 & 124) MA 115 Statistics Summer Environmental Internship Junior Year CH 171 Chem for Health Sciences CH in Environmental Sciences is 17 courses. Courses taken to satisfy CAS major requirements (required, principal, core

  12. GAMMA RAYS FROM STAR FORMATION IN CLUSTERS OF GALAXIES

    SciTech Connect (OSTI)

    Storm, Emma M.; Jeltema, Tesla E.; Profumo, Stefano [Department of Physics, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States)

    2012-08-20T23:59:59.000Z

    Star formation in galaxies is observed to be associated with gamma-ray emission, presumably from non-thermal processes connected to the acceleration of cosmic-ray nuclei and electrons. The detection of gamma rays from starburst galaxies by the Fermi Large Area Telescope (LAT) has allowed the determination of a functional relationship between star formation rate and gamma-ray luminosity. Since star formation is known to scale with total infrared (8-1000 {mu}m) and radio (1.4 GHz) luminosity, the observed infrared and radio emission from a star-forming galaxy can be used to quantitatively infer the galaxy's gamma-ray luminosity. Similarly, star-forming galaxies within galaxy clusters allow us to derive lower limits on the gamma-ray emission from clusters, which have not yet been conclusively detected in gamma rays. In this study, we apply the functional relationships between gamma-ray luminosity and radio and IR luminosities of galaxies derived by the Fermi Collaboration to a sample of the best candidate galaxy clusters for detection in gamma rays in order to place lower limits on the gamma-ray emission associated with star formation in galaxy clusters. We find that several clusters have predicted gamma-ray emission from star formation that are within an order of magnitude of the upper limits derived in Ackermann et al. based on non-detection by Fermi-LAT. Given the current gamma-ray limits, star formation likely plays a significant role in the gamma-ray emission in some clusters, especially those with cool cores. We predict that both Fermi-LAT over the course of its lifetime and the future Cerenkov Telescope Array will be able to detect gamma-ray emission from star-forming galaxies in clusters.

  13. CONSTRAINING INTERMEDIATE-MASS BLACK HOLES IN GLOBULAR CLUSTERS

    SciTech Connect (OSTI)

    Umbreit, Stefan; Rasio, Frederic A., E-mail: s-umbreit@northwestern.edu, E-mail: rasio@northwestern.edu [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Rd, Evanston, IL 60208 (United States)

    2013-05-01T23:59:59.000Z

    Decades after the first predictions of intermediate-mass black holes (IMBHs) in globular clusters (GCs) there is still no unambiguous observational evidence for their existence. The most promising signatures for IMBHs are found in the cores of GCs, where the evidence now comes from the stellar velocity distribution, the surface density profile, and, for very deep observations, the mass-segregation profile near the cluster center. However, interpretation of the data, and, in particular, constraints on central IMBH masses, require the use of detailed cluster dynamical models. Here we present results from Monte Carlo cluster simulations of GCs that harbor IMBHs. As an example of application, we compare velocity dispersion, surface brightness and mass-segregation profiles with observations of the GC M10, and constrain the mass of a possible central IMBH in this cluster. We find that, although M10 does not seem to possess a cuspy surface density profile, the presence of an IMBH with a mass up to 0.75% of the total cluster mass, corresponding to about 600 M{sub Sun }, cannot be excluded. This is also in agreement with the surface brightness profile, although we find it to be less constraining, as it is dominated by the light of giants, causing it to fluctuate significantly. We also find that the mass-segregation profile cannot be used to discriminate between models with and without IMBH. The reason is that M10 is not yet dynamically evolved enough for the quenching of mass segregation to take effect. Finally, detecting a velocity dispersion cusp in clusters with central densities as low as in M10 is extremely challenging, and has to rely on only 20-40 bright stars. It is only when stars with masses down to 0.3 M{sub Sun} are included that the velocity cusp is sampled close enough to the IMBH for a significant increase above the core velocity dispersion to become detectable.

  14. Intelligent choice of the number of clusters in K-Means clustering: an experimental study with different cluster spreads1

    E-Print Network [OSTI]

    Mirkin, Boris

    1 Intelligent choice of the number of clusters in K-Means clustering: an experimental study The issue of determining "the right number of clusters" in K-Means has attracted considerable interest of the cluster recovery. The subjects of our interest are two versions of the "intelligent" K-Means method, ik

  15. Physical component analysis of galaxy cluster weak gravitational lensing data

    E-Print Network [OSTI]

    Phil Marshall

    2007-10-30T23:59:59.000Z

    We present a novel approach for reconstructing the projected mass distribution of clusters of galaxies from sparse and noisy weak gravitational lensing shear data. The reconstructions are regularised using knowledge gained from numerical simulations of clusters: trial mass distributions are constructed from N physically-motivated components, each of which has the universal density profile and characteristic geometry observed in simulated clusters. The parameters of these components are assumed to be distributed \\emph{a priori} in the same way as they are in the simulated clusters. Sampling mass distributions from the components' parameters' posterior probability density function allows estimates of the mass distribution to be generated, with error bars. The appropriate number of components is inferred from the data itself via the Bayesian evidence, and is typically found to be small, reflecting the quality of the simulated data used in this work. Ensemble average mass maps are found to be robust to the details of the noise realisation, and succeed in recovering the input mass distribution (from a realistic simulated cluster) over a wide range of scales. We comment on the residuals of the reconstruction and their implications, and discuss the extension of the method to include strong lensing information.

  16. A photometric investigation of the young open cluster Trumpler 15

    E-Print Network [OSTI]

    Carraro, G

    2002-01-01T23:59:59.000Z

    In this paper we present and analyze new CCD $UBVRI$ photometry down to $V\\approx$21 in the region of the young open cluster Trumpler~15, located in the Carina spiral feature. The cluster is rather compact and has a core radius of about 2$^{\\prime}$, which translates in about 1 pc at the distance of the cluster. We provide the first CCD investigation and update its fundamental parameters. We identify 90 candidate photometric members on the base of the position in the color-color and color-magnitude diagrams. This sample allows us to obtain a distance of 2.4$\\pm$0.3 kpc from the Sun and a reddening E$(B-V)$=0.52$\\pm0.07$. We confirm that the cluster is young, and fix a upper limit of 6 million yrs to its age . In addition, we draw the attention on the lower part of the Main Sequence (MS) suggesting that some stars can be in contracting phase and on a gap in the MS, that we show to be a real feature, the $B1-B5$ gap found in other young open clusters. We finally study in details the extinction toward Trumpler~1...

  17. The quest for cosmic ray protons in galaxy clusters

    E-Print Network [OSTI]

    Christoph Pfrommer; Torsten A. Ensslin

    2004-12-15T23:59:59.000Z

    There have been many speculations about the presence of cosmic ray protons (CRps) in galaxy clusters over the past two decades. However, no direct evidence such as the characteristic gamma-ray signature of decaying pions has been found so far. These pions would be a direct tracer of hadronic CRp interactions with the ambient thermal gas also yielding observable synchrotron and inverse Compton emission by additionally produced secondary electrons. The obvious question concerns the type of galaxy clusters most likely to yield a signal: Particularly suited sites should be cluster cooling cores due to their high gas and magnetic energy densities. We studied a nearby sample of clusters evincing cooling cores in order to place stringent limits on the cluster CRp population by using non-detections of EGRET. In this context, we examined the possibility of a hadronic origin of Coma-sized radio halos as well as radio mini-halos. Especially for mini-halos, strong clues are provided by the very plausible small amount of required CRp energy density and a matching radio profile. Introducing the hadronic minimum energy criterion, we show that the energetically favored CRp energy density is constrained to 2% +/- 1% of the thermal energy density in Perseus. We also studied the CRp population within the cooling core region of Virgo using the TeV gamma-ray detection of M 87 by HEGRA. Both the expected radial gamma-ray profile and the required amount of CRp support this hadronic scenario.

  18. The BMW Deep X-ray Cluster Survey

    E-Print Network [OSTI]

    L. Guzzo; A. Moretti; S. Campana; S. Covino; I. Dell'Antonio; D. Lazzati; M. Longhetti; E. Molinari; M. R. Panzera; G. Tagliaferri

    2001-01-24T23:59:59.000Z

    We briefly describe the main features of the Brera Multi-Wavelet (BMW) survey of serendipitous X-ray clusters, based on the still unexploited ROSAT-HRI archival observations. Cluster candidates are selected from the general BMW catalogue of 20,000 sources based exclusively on their X-ray extension. Contrary to common wisdom, a clever selection of the HRI energy channels allows us to significantly reduce the background noise, thus greatly improving the ability to detect low surface-brightness sources as clusters. The resulting sample of ~250 candidates shows a very good sky coverage down to a flux \\~3x10^-14 erg/s/cm^2 ([0.5-2.0] keV band), i.e comparable to existing PSPC-based deep survey, with a particularly interesting area of ~100 sq.deg. around fluxes ~10^-13 erg/s/cm^2, i.e. where highly-luminous, rare systems at z~0.6-1 can be detected. At the same time, the superior angular resolution of the instrument should avoid biases against intrinsically small systems, while easing the identification process (e.g. by spotting blends and AGN contaminants). While about 20% of the candidates are already identified with groups/clusters at z0.5) bonafide cluster counterpart for ~80% of the targets.

  19. A wide-field photometric study of the globular cluster system of NGC 4636

    E-Print Network [OSTI]

    Boris Dirsch; Ylva Schuberth; Tom Richtler

    2005-03-13T23:59:59.000Z

    We investigate the unusually rich cluster system of NGC4636 with wide-field Washington photometry. The globular cluster luminosity function can be followed roughly 1 mag beyond the turn-over magnitude. This corresponds to a distance modulus of m-M=31.24+-0.17, 0.4 mag larger than the distance determined from surface brightness fluctuations. The high specific frequency is confirmed, yet the exact value remains uncertain because of the uncertain distance: it varies between 5.6+-1.2 and 8.9+-1.2. The globular cluster system has a clearly bimodal color distribution. The color peak positions show no radial dependence and are in good agreement with the values found for other galaxies studied in the same filter system. However, a luminosity dependence is found: brighter clusters with an ``intermediate'' color exist. The clusters exhibit a shallow radial distribution within 7'.Within the same radial interval, the galaxy light has a distinctly steeper profile. Because of the difference in the cluster and light distribution the specific frequency increases considerably with radius. At 7' and 9' the density profiles of the red and blue clusters, respectively, change strongly which indicates that we reach the outer rim of the cluster system at approximately 11'. This feature is seen for the first time in a globular cluster system. While the radial distribution of the cluster and field populations are rather different, this is not true for the ellipticity of the system: the elongation as well as the position angle of the cluster system agree well with the galaxy light. We compare the radial distribution of globular clusters with the light profiles for a sample of elliptical galaxies. The difference observed in NGC 4636 is typical of an elliptical galaxy of this luminosity.

  20. Characterization of sampling cyclones

    E-Print Network [OSTI]

    Moore, Murray Edward

    1986-01-01T23:59:59.000Z

    Farland, who' provided an excellent opportunity for the enhancement of my engineering career. To Dr. Best for his patient snd competent assistance in this project. To Dr. Parish who gave his service to my graduate committee. To Bob DeOtte and Carlos Ortiz... in air sampling standards, several different samplers have been developed which utilize either inertial impaction or cyclonic flow fractionation techniques. For example, a 10 pm cutpoint size selective inlet was developed by McFarland, Ortiz...

  1. PHAT Stellar Cluster Survey. II. Andromeda Project Cluster Catalog

    E-Print Network [OSTI]

    Johnson, L Clifton; Dalcanton, Julianne J; Wallace, Matthew L; Simpson, Robert J; Lintott, Chris J; Kapadia, Amit; Skillman, Evan D; Caldwell, Nelson; Fouesneau, Morgan; Weisz, Daniel R; Williams, Benjamin F; Beerman, Lori C; Gouliermis, Dimitrios A; Sarajedini, Ata

    2015-01-01T23:59:59.000Z

    We construct a stellar cluster catalog for the Panchromatic Hubble Andromeda Treasury (PHAT) survey using image classifications collected from the Andromeda Project citizen science website. We identify 2,753 clusters and 2,270 background galaxies within ~0.5 deg$^2$ of PHAT imaging searched, or ~400 kpc$^2$ in deprojected area at the distance of the Andromeda galaxy (M31). These identifications result from 1.82 million classifications of ~20,000 individual images (totaling ~7 gigapixels) by tens of thousands of volunteers. We show that our crowd-sourced approach, which collects >80 classifications per image, provides a robust, repeatable method of cluster identification. The high spatial resolution Hubble Space Telescope images resolve individual stars in each cluster and are instrumental in the factor of ~6 increase in the number of clusters known within the survey footprint. We measure integrated photometry in six filter passbands, ranging from the near-UV to the near-IR. PHAT clusters span a range of ~8 ma...

  2. A DEEP UBVRI CCD PHOTOMETRY OF SIX OPEN STAR CLUSTERS IN THE GALACTIC ANTICENTER REGION

    SciTech Connect (OSTI)

    Lata, Sneh; Pandey, Anil K.; Kumar, Brijesh; Bhatt, Himali; Pace, Giancarlo; Sharma, Saurabh [ARIES, Manora Peak, Nainital-263129, Uttarakhand (India)], E-mail: sneh@aries.res.in

    2010-02-15T23:59:59.000Z

    We present deep UBVRI CCD photometry of six open star clusters situated in the Galactic anticenter region (l{approx} 120-200 deg.). The sample includes three unstudied (Be 6, Be 77, King 17) and three partly studied open clusters (Be 9, NGC 2186, and NGC 2304). The fundamental parameters have been determined by comparing color-color and color-magnitude diagrams with the theoretical models. The structural parameters and morphology of the clusters were discussed on the basis of radial density profiles and isodensity contours, respectively. The isodensity contours show that all the clusters have asymmetric shapes. An investigation of structural parameters indicates that the evolution of core and corona of the clusters is mainly controlled by internal relaxation processes.

  3. Planck 2015 results. XXIV. Cosmology from Sunyaev-Zeldovich cluster counts

    E-Print Network [OSTI]

    Ade, P A R; Arnaud, M; Ashdown, M; Aumont, J; Baccigalupi, C; Banday, A J; Barreiro, R B; Bartlett, J G; Bartolo, N; Battaner, E; Battye, R; Benabed, K; Benoît, A; Benoit-Lévy, A; Bernard, J -P; Bersanelli, M; Bielewicz, P; Bonaldi, A; Bonavera, L; Bond, J R; Borrill, J; Bouchet, F R; Bucher, M; Burigana, C; Butler, R C; Calabrese, E; Cardoso, J -F; Catalano, A; Challinor, A; Chamballu, A; Chary, R -R; Chiang, H C; Christensen, P R; Church, S; Clements, D L; Colombi, S; Colombo, L P L; Combet, C; Comis, B; Couchot, F; Coulais, A; Crill, B P; Curto, A; Cuttaia, F; Danese, L; Davies, R D; Davis, R J; de Bernardis, P; de Rosa, A; de Zotti, G; Delabrouille, J; Désert, F -X; Diego, J M; Dolag, K; Dole, H; Donzelli, S; Doré, O; Douspis, M; Ducout, A; Dupac, X; Efstathiou, G; Elsner, F; Enßlin, T A; Eriksen, H K; Falgarone, E; Fergusson, J; Finelli, F; Forni, O; Frailis, M; Fraisse, A A; Franceschi, E; Frejsel, A; Galeotta, S; Galli, S; Ganga, K; Giard, M; Giraud-Héraud, Y; Gjerløw, E; González-Nuevo, J; Górski, K M; Gratton, S; Gregorio, A; Gruppuso, A; Gudmundsson, J E; Hansen, F K; Hanson, D; Harrison, D L; Henrot-Versillé, S; Hernández-Monteagudo, C; Herranz, D; Hildebrandt, S R; Hivon, E; Hobson, M; Holmes, W A; Hornstrup, A; Hovest, W; Huffenberger, K M; Hurier, G; Jaffe, A H; Jaffe, T R; Jones, W C; Juvela, M; Keihänen, E; Keskitalo, R; Kisner, T S; Kneissl, R; Knoche, J; Kunz, M; Kurki-Suonio, H; Lagache, G; Lähteenmäki, A; Lamarre, J -M; Lasenby, A; Lattanzi, M; Lawrence, C R; Leonardi, R; Lesgourgues, J; Levrier, F; Liguori, M; Lilje, P B; Linden-Vørnle, M; López-Caniego, M; Lubin, P M; Macías-Pérez, J F; Maggio, G; Maino, D; Mandolesi, N; Mangilli, A; Martin, P G; Martínez-González, E; Masi, S; Matarrese, S; Mazzotta, P; McGehee, P; Meinhold, P R; Melchiorri, A; Melin, J -B; Mendes, L; Mennella, A; Migliaccio, M; Mitra, S; Miville-Deschênes, M -A; Moneti, A; Montier, L; Morgante, G; Mortlock, D; Moss, A; Munshi, D; Murphy, J A; Naselsky, P; Nati, F; Natoli, P; Netterfield, C B; Nørgaard-Nielsen, H U; Noviello, F; Novikov, D; Novikov, I; Oxborrow, C A; Paci, F; Pagano, L; Pajot, F; Paoletti, D; Partridge, B; Pasian, F; Patanchon, G; Pearson, T J; Perdereau, O; Perotto, L; Perrotta, F; Pettorino, V; Piacentini, F; Piat, M; Pierpaoli, E; Pietrobon, D; Plaszczynski, S; Pointecouteau, E; Polenta, G; Popa, L; Pratt, G W; Prézeau, G; Prunet, S; Puget, J -L; Rachen, J P; Rebolo, R; Reinecke, M; Remazeilles, M; Renault, C; Renzi, A; Ristorcelli, I; Rocha, G; Roman, M; Rosset, C; Rossetti, M; Roudier, G; Rubiño-Martín, J A; Rusholme, B; Sandri, M; Santos, D; Savelainen, M; Savini, G; Scott, D; Seiffert, M D; Shellard, E P S; Spencer, L D; Stolyarov, V; Stompor, R; Sudiwala, R; Sunyaev, R; Sutton, D; Suur-Uski, A -S; Sygnet, J -F; Tauber, J A; Terenzi, L; Toffolatti, L; Tomasi, M; Tristram, M; Tucci, M; Tuovinen, J; Türler, M; Umana, G; Valenziano, L; Valiviita, J; Van Tent, B; Vielva, P; Villa, F; Wade, L A; Wandelt, B D; Wehus, I K; Weller, J; White, S D M; Yvon, D; Zacchei, A; Zonca, A

    2015-01-01T23:59:59.000Z

    We present cluster counts and corresponding cosmological constraints from the Planck full mission data set. Our catalogue consists of 439 clusters detected via their Sunyaev-Zeldovich (SZ) signal down to a signal-to-noise of six, and is more than a factor of two larger than the 2013 Planck cluster cosmology sample. The counts are consistent with those from 2013 and yield compatible constraints under the same modelling assumptions. Taking advantage of the larger catalogue, we extend our analysis to the two-dimensional distribution in redshift and signal-to-noise. We use mass estimates from two recent studies of gravitational lensing of background galaxies by Planck clusters to provide priors on the hydrostatic bias parameter, $1-b$. In addition, we use lensing of cosmic microwave background (CMB) temperature fluctuations by Planck clusters as a third independent constraint on this parameter. These various calibrations imply constraints on the present-day amplitude of matter fluctuations in varying degrees of t...

  4. Functional Clustering in Nested Designs Abel Rodriguez

    E-Print Network [OSTI]

    West, Mike

    -spline fitting coupled with k-means clustering; Tarpey & Kinateder (2003), who apply k-means clustering via functional data that employ spline representations; Garc´ia-Escudero & Gordaliza (2005), where the robust k-means profile for each woman. #12;Functional Clustering in Nested Designs 3 with k-means clustering; Heard et al

  5. Post-Award Deliverables Sample (Second Part of Sample Deliverables...

    Broader source: Energy.gov (indexed) [DOE]

    samplereptgrqmts.doc More Documents & Publications ESPC Sample Deliverables for Task Orders (IDIQ Attachment. J-4) Sample Statement of Work - Standard Service Offerings for...

  6. POLYCYCLIC AROMATIC HYDROCARBONS, IONIZED GAS, AND MOLECULAR HYDROGEN IN BRIGHTEST CLUSTER GALAXIES OF COOL-CORE CLUSTERS OF GALAXIES

    SciTech Connect (OSTI)

    Donahue, Megan; Mark Voit, G.; Hoffer, Aaron [Physics and Astronomy Department, Michigan State University, East Lansing, MI 48824 (United States); De Messieres, Genevieve E.; O'Connell, Robert W. [Astronomy Department, University of Virginia, Charlottesville, VA (United States); McNamara, Brian R. [Department of Physics and Astronomy, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1 (Canada); Nulsen, Paul E. J., E-mail: donahue@pa.msu.edu, E-mail: voit@pa.msu.edu, E-mail: hofferaa@msu.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2011-05-01T23:59:59.000Z

    We present measurements of 5-25 {mu}m emission features of brightest cluster galaxies (BCGs) with strong optical emission lines in a sample of nine cool-core clusters of galaxies observed with the Infrared Spectrograph on board the Spitzer Space Telescope. These systems provide a view of dusty molecular gas and star formation, surrounded by dense, X-ray-emitting intracluster gas. Past work has shown that BCGs in cool-core clusters may host powerful radio sources, luminous optical emission-line systems, and excess UV, while BCGs in other clusters never show this activity. In this sample, we detect polycyclic aromatic hydrocarbons (PAHs), extremely luminous, rotationally excited molecular hydrogen line emission, forbidden line emission from ionized gas ([Ne II] and [Ne III]), and infrared continuum emission from warm dust and cool stars. We show here that these BCGs exhibit more luminous forbidden neon and H{sub 2} rotational line emission than star-forming galaxies with similar total infrared luminosities, as well as somewhat higher ratios of 70 {mu}m/24 {mu}m luminosities. Our analysis suggests that while star formation processes dominate the heating of the dust and PAHs, a heating process consistent with suprathermal electron heating from the hot gas, distinct from star formation, is heating the molecular gas and contributing to the heating of the ionized gas in the galaxies. The survival of PAHs and dust suggests that dusty gas is somehow shielded from significant interaction with the X-ray gas.

  7. Infrared spectroscopy of ionic clusters

    SciTech Connect (OSTI)

    Price, J.M. (California Univ., Berkeley, CA (USA). Dept. of Chemistry Lawrence Berkeley Lab., CA (USA))

    1990-11-01T23:59:59.000Z

    This thesis describes new experiments wherein the infrared vibrational predissociation spectra of a number of mass-selected ionic cluster systems have been obtained and analyzed in the 2600 to 4000 cm{sup {minus}1} region. The species studied include: the hydrated hydronium ions, H{sub 3}O{sup +} (H{sub 2}O){sub 3 {minus}10}, ammoniated ammonium ions, NH{sub 4}{sup +}(NH{sub 3}){sub 1 {minus}10} and cluster ions involving both water and ammonia around an ammonium ion core, (mixed clusters) NH{sub 4}{sup +}(NH{sub 3}){sub n}(H{sub 2}O){sub m} (n+m=4). In each case, the spectra reveal well resolved structures that can be assigned to transitions arising from the vibrational motions of both the ion core of the clusters and the surrounding neutral solvent molecules. 154 refs., 19 figs., 8 tabs.

  8. The Leadership Cluster Memorial Union

    E-Print Network [OSTI]

    Escher, Christine

    The Leadership Cluster Memorial Union Student Leadership and Involvement Student Media Something New @ OSU #12;Access Diversity "Leadership/Citizenship" Community Connection Health & Wellness Housing & Dining Administrative Leadership #12;Student Leadership & Involvement SLI-Activities Program Club

  9. Multi-source contingency clustering

    E-Print Network [OSTI]

    Bouvrie, Jacob V

    2004-01-01T23:59:59.000Z

    This thesis examines the problem of clustering multiple, related sets of data simultaneously. Given datasets which are in some way connected (e.g. temporally) but which do not necessarily share label compatibility, we ...

  10. Clusters and the Cosmic Web

    E-Print Network [OSTI]

    Rien van de Weygaert

    2006-07-24T23:59:59.000Z

    We discuss the intimate relationship between the filamentary features and the rare dense compact cluster nodes in this network, via the large scale tidal field going along with them, following the cosmic web theory developed Bond et al. The Megaparsec scale tidal shear pattern is responsible for the contraction of matter into filaments, and its link with the cluster locations can be understood through the implied quadrupolar mass distribution in which the clusters are to be found at the sites of the overdense patches. We present a new technique for tracing the cosmic web, identifying planar walls, elongated filaments and cluster nodes in the galaxy distribution. This will allow the practical exploitation of the concept of the cosmic web towards identifying and tracing the locations of the gaseous WHIM. These methods, the Delaunay Tessellation Field Estimator (DTFE) and the Morphology Multiscale Filter (MMF) find their basis in computational geometry and visualization.

  11. Decoupled Sampling for Graphics Pipelines

    E-Print Network [OSTI]

    Ragan-Kelley, Jonathan Millar

    We propose a generalized approach to decoupling shading from visibility sampling in graphics pipelines, which we call decoupled sampling. Decoupled sampling enables stochastic supersampling of motion and defocus blur at ...

  12. Fluid sampling apparatus and method

    DOE Patents [OSTI]

    Yeamans, David R. (Los Alamos, NM)

    1998-01-01T23:59:59.000Z

    Incorporation of a bellows in a sampling syringe eliminates ingress of contaminants, permits replication of amounts and compression of multiple sample injections, and enables remote sampling for off-site analysis.

  13. Fluid sampling apparatus and method

    DOE Patents [OSTI]

    Yeamans, D.R.

    1998-02-03T23:59:59.000Z

    Incorporation of a bellows in a sampling syringe eliminates ingress of contaminants, permits replication of amounts and compression of multiple sample injections, and enables remote sampling for off-site analysis. 3 figs.

  14. Dust cluster explosion

    SciTech Connect (OSTI)

    Saxena, Vikrant [School of Mathematics and Physics, Queen's University Belfast, Belfast, Northern Ireland (United Kingdom); Institute for Plasma Research, Bhat, Gandhinagar (India); Avinash, K. [Department of Physics and Astrophysics, University of Delhi, New Delhi (India); Sen, A. [Institute for Plasma Research, Bhat, Gandhinagar (India)

    2012-09-15T23:59:59.000Z

    A model for the dust cluster explosion where micron/sub-micron sized particles are accelerated at the expense of plasma thermal energy, in the afterglow phase of a complex plasma discharge is proposed. The model is tested by molecular dynamics simulations of dust particles in a confining potential. The nature of the explosion (caused by switching off the discharge) and the concomitant dust acceleration is found to depend critically on the pressure of the background neutral gas. At low gas pressure, the explosion is due to unshielded Coulomb repulsion between dust particles and yields maximum acceleration, while in the high pressure regime it is due to shielded Yukawa repulsion and yields much feebler acceleration. These results are in agreement with experimental findings. Our simulations also confirm a recently proposed electrostatic (ES) isothermal scaling relation, P{sub E}{proportional_to}V{sub d}{sup -2} (where P{sub E} is the ES pressure of the dust particles and V{sub d} is the confining volume).

  15. Adhesive Gravitational Clustering

    E-Print Network [OSTI]

    Thomas Buchert; Alvaro Dominguez

    2005-06-21T23:59:59.000Z

    The notion of `adhesion' has been advanced for the phenomenon of stabilization of large-scale structure emerging from gravitational instability of a cold medium. Recently, the physical origin of adhesion has been identified: a systematic derivation of the equations of motion for the density and the velocity fields leads naturally to the key equation of the `adhesion approximation' - however, under a set of strongly simplifying assumptions. In this work, we provide an evaluation of the current status of adhesive gravitational clustering and a clear explanation of the assumptions involved. Furthermore, we propose systematic generalizations with the aim to relax some of the simplifying assumptions. We start from the general Newtonian evolution equations for self-gravitating particles on an expanding Friedmann background and recover the popular `dust model' (pressureless fluid), which breaks down after the formation of density singularities; then we investigate, in a unified framework, two other models which, under the restrictions referred to above, lead to the `adhesion approximation'. We apply the Eulerian and Lagrangian perturbative expansions to these new models and, finally, we discuss some non-perturbative results that may serve as starting points for workable approximations of non-linear structure formation in the multi-stream regime. In particular, we propose a new approximation that includes, in limiting cases, the standard `adhesion model' and the Eulerian as well as Lagrangian first-order approximations.

  16. Soil sampling kit and a method of sampling therewith

    DOE Patents [OSTI]

    Thompson, Cyril V. (Knoxville, TN)

    1991-01-01T23:59:59.000Z

    A soil sampling device and a sample containment device for containing a soil sample is disclosed. In addition, a method for taking a soil sample using the soil sampling device and soil sample containment device to minimize the loss of any volatile organic compounds contained in the soil sample prior to analysis is disclosed. The soil sampling device comprises two close fitting, longitudinal tubular members of suitable length, the inner tube having the outward end closed. With the inner closed tube withdrawn a selected distance, the outer tube can be inserted into the ground or other similar soft material to withdraw a sample of material for examination. The inner closed end tube controls the volume of the sample taken and also serves to eject the sample. The soil sample containment device has a sealing member which is adapted to attach to an analytical apparatus which analyzes the volatile organic compounds contained in the sample. The soil sampling device in combination with the soil sample containment device allow an operator to obtain a soil sample containing volatile organic compounds and minimizing the loss of the volatile organic compounds prior to analysis of the soil sample for the volatile organic compounds.

  17. Soil sampling kit and a method of sampling therewith

    DOE Patents [OSTI]

    Thompson, C.V.

    1991-02-05T23:59:59.000Z

    A soil sampling device and a sample containment device for containing a soil sample is disclosed. In addition, a method for taking a soil sample using the soil sampling device and soil sample containment device to minimize the loss of any volatile organic compounds contained in the soil sample prior to analysis is disclosed. The soil sampling device comprises two close fitting, longitudinal tubular members of suitable length, the inner tube having the outward end closed. With the inner closed tube withdrawn a selected distance, the outer tube can be inserted into the ground or other similar soft material to withdraw a sample of material for examination. The inner closed end tube controls the volume of the sample taken and also serves to eject the sample. The soil sample containment device has a sealing member which is adapted to attach to an analytical apparatus which analyzes the volatile organic compounds contained in the sample. The soil sampling device in combination with the soil sample containment device allows an operator to obtain a soil sample containing volatile organic compounds and minimizing the loss of the volatile organic compounds prior to analysis of the soil sample for the volatile organic compounds. 11 figures.

  18. INTEGRAL observations of Galaxy Clusters

    E-Print Network [OSTI]

    Goldoni, P; Laurent, P; Cassé, M; Paul, J; Sarazin, C L

    2000-01-01T23:59:59.000Z

    Cluster of galaxies are the largest concentrations of visible mass in the Universe and therefore a fundamental topic of cosmology and astrophysics. Recent radio, EUV, and X-ray observations suggest that clusters contain large populations of diffuse nonthermal relativistic and/or superthermal particles. These particles may be produced by acceleration in cluster merger shocks, AGNs, and/or supernovae in cluster galaxies. Models for the nonthermal populations in clusters indicate that they should produce substantial hard X-ray and $\\gamma$ luminosities. The possible role of nonthermal particles in the dynamics of clusters is one of the greatest uncertainties in their use as cosmological probes. INTEGRAL offers, for the first time, the possibility of simultaneous medium resolution imaging (~ 12 arcmin) and high resolution spectroscopy (DeltaE/E ~ 2 keV @ 1.3 MeV) with exceptional sensitivity in the hard X-ray/soft gamma-ray band. The spatial resolution will allow discrete sources, such as AGNs, to be separated fr...

  19. Internal gettering by metal alloy clusters

    DOE Patents [OSTI]

    Buonassisi, Anthony (San Diego, CA); Heuer, Matthias (Berkeley, CA); Istratov, Andrei A. (Albany, CA); Pickett, Matthew D. (Berkeley, CA); Marcus, Mathew A. (Berkeley, CA); Weber, Eicke R. (Piedmont, CA)

    2010-07-27T23:59:59.000Z

    The present invention relates to the internal gettering of impurities in semiconductors by metal alloy clusters. In particular, intermetallic clusters are formed within silicon, such clusters containing two or more transition metal species. Such clusters have melting temperatures below that of the host material and are shown to be particularly effective in gettering impurities within the silicon and collecting them into isolated, less harmful locations. Novel compositions for some of the metal alloy clusters are also described.

  20. Some Remarks on Extragalactic Globular Clusters

    E-Print Network [OSTI]

    Tom Richtler

    2005-12-21T23:59:59.000Z

    I comment (in a review fashion) on a few selected topics in the field of extragalactic globular clusters with strong emphasis on recent work. The topics are: bimodality in the colour distribution of cluster systems, young massive clusters, and the brightest old clusters. Globular cluster research, perhaps more than ever, has lead to important (at least to astronomers) progress and problems in galaxy structure and formation.

  1. 2?52Cf plasma desorption mass spectrometry of metal clusters

    E-Print Network [OSTI]

    Hughes, Janita Muriel

    1991-01-01T23:59:59.000Z

    crystals. Some of these compounds have been investigated by 'Cf Plasma Desorption Mass Spectrometry (PDMS), which has in many cases provided the first direct confirmation of the proposed structure. Analysis of large platinum carbonyl anions has yielded..., 000. In the field of gold cluster chemistry, the Cf-PDMS spectra has demonstrated that the synthetic pmcesses involved in forming Au?results in the mixture of large clusters rather than a monodisperse sample. These results have provided interesting...

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

    E-Print Network [OSTI]

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

    2008-05-09T23:59:59.000Z

    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 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 $16\\times16$ 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.

  3. NID Copper Sample Analysis

    SciTech Connect (OSTI)

    Kouzes, Richard T.; Zhu, Zihua

    2011-09-12T23:59:59.000Z

    The current focal point of the nuclear physics program at PNNL is the MAJORANA DEMONSTRATOR, and the follow-on Tonne-Scale experiment, a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay (0???). This experiment requires the use of germanium isotopically enriched in 76Ge. The MAJORANA DEMONSTRATOR is a DOE and NSF funded project with a major science impact. The DEMONSTRATOR will utilize 76Ge from Russia, but for the Tonne-Scale experiment it is hoped that an alternate technology, possibly one under development at Nonlinear Ion Dynamics (NID), will be a viable, US-based, lower-cost source of separated material. Samples of separated material from NID require analysis to determine the isotopic distribution and impurities. DOE is funding NID through an SBIR grant for development of their separation technology for application to the Tonne-Scale experiment. The Environmental Molecular Sciences facility (EMSL), a DOE user facility at PNNL, has the required mass spectroscopy instruments for making isotopic measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR and for the development of the future separation technology required for the Tonne-Scale experiment. A sample of isotopically separated copper was provided by NID to PNNL in January 2011 for isotopic analysis as a test of the NID technology. The results of that analysis are reported here. A second sample of isotopically separated copper was provided by NID to PNNL in August 2011 for isotopic analysis as a test of the NID technology. The results of that analysis are also reported here.

  4. Germanium-76 Sample Analysis

    SciTech Connect (OSTI)

    Kouzes, Richard T.; Engelhard, Mark H.; Zhu, Zihua

    2011-04-01T23:59:59.000Z

    The MAJORANA DEMONSTRATOR is a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay (0???). The DEMONSTRATOR will utilize 76Ge from Russia, and the first one gram sample was received from the supplier for analysis on April 24, 2011. The Environmental Molecular Sciences facility, a DOE user facility at PNNL, was used to make the required isotopic and chemical purity measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR. The results of this first analysis are reported here.

  5. Stack sampling apparatus

    DOE Patents [OSTI]

    Lind, Randall F; Lloyd, Peter D; Love, Lonnie J; Noakes, Mark W; Pin, Francois G; Richardson, Bradley S; Rowe, John C

    2014-09-16T23:59:59.000Z

    An apparatus for obtaining samples from a structure includes a support member, at least one stabilizing member, and at least one moveable member. The stabilizing member has a first portion coupled to the support member and a second portion configured to engage with the structure to restrict relative movement between the support member and the structure. The stabilizing member is radially expandable from a first configuration where the second portion does not engage with a surface of the structure to a second configuration where the second portion engages with the surface of the structure.

  6. Draft Sample Collection Instrument

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny:Revised Finding of No53197E T ADRAFTJanuaryDominionDowDepartmentPublic5 5Sample

  7. September 2004 Water Sampling

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA group currentBradleyTableSelling7 AugustAFRICAN3u ;;;::Sampling at the Sherwood,

  8. September 2004 Water Sampling

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA groupTuba City, Arizona, DisposalFourthN V O 1CentralGroundwater,Sampling at the

  9. September 2004 Water Sampling

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA groupTuba City, Arizona, DisposalFourthN V O 1CentralGroundwater,Sampling at the4

  10. September 2004 Water Sampling

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA groupTuba City, Arizona, DisposalFourthN V O 1CentralGroundwater,Sampling at

  11. September 2004 Water Sampling

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA groupTuba City, Arizona, DisposalFourthN V O 1CentralGroundwater,Sampling

  12. September 2004 Water Sampling

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA groupTuba City, Arizona, DisposalFourthN V O 1CentralGroundwater,SamplingTuba

  13. September 2004 Water Sampling

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA groupTuba City, Arizona, DisposalFourthN V O 1CentralGroundwater,SamplingTubaand

  14. Measuring the mean and scatter of the X-ray luminosity -- optical richness relation for maxBCG galaxy clusters

    E-Print Network [OSTI]

    E. S. Rykoff; T. A. McKay; M. R. Becker; A. Evrard; D. E. Johnston; B. P. Koester; E. Rozo; E. S. Sheldon; R. H. Wechsler

    2007-12-05T23:59:59.000Z

    Determining the scaling relations between galaxy cluster observables requires large samples of uniformly observed clusters. We measure the mean X-ray luminosity--optical richness (L_X--N_200) relation for an approximately volume-limited sample of more than 17,000 optically-selected clusters from the maxBCG catalog spanning the redshift range 0.1clusters using ROSAT All-Sky Survey data, we are able to measure mean X-ray luminosities to ~10% (including systematic errors) for clusters in nine independent optical richness bins. In addition, we are able to crudely measure individual X-ray emission from ~800 of the richest clusters. Assuming a log-normal form for the scatter in the L_X--N_200 relation, we measure \\sigma_\\ln{L}=0.86+/-0.03 at fixed N_200. This scatter is large enough to significantly bias the mean stacked relation. The corrected median relation can be parameterized by L_X = (e^\\alpha)(N_200/40)^\\beta 10^42 h^-2 ergs/s, where \\alpha = 3.57+/-0.08 and \\beta = 1.82+/-0.05. We find that X-ray selected clusters are significantly brighter than optically-selected clusters at a given optical richness. This selection bias explains the apparently X-ray underluminous nature of optically-selected cluster catalogs.

  15. NID Copper Sample Analysis

    SciTech Connect (OSTI)

    Kouzes, Richard T.; Zhu, Zihua

    2011-02-01T23:59:59.000Z

    The current focal point of the nuclear physics program at PNNL is the MAJORANA DEMONSTRATOR, and the follow-on Tonne-Scale experiment, a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay (0???). This experiment requires the use of germanium isotopically enriched in 76Ge. The DEMONSTRATOR will utilize 76Ge from Russia, but for the Tonne-Scale experiment it is hoped that an alternate technology under development at Nonlinear Ion Dynamics (NID) will be a viable, US-based, lower-cost source of separated material. Samples of separated material from NID require analysis to determine the isotopic distribution and impurities. The MAJORANA DEMONSTRATOR is a DOE and NSF funded project with a major science impact. DOE is funding NID through an SBIR grant for development of their separation technology for application to the Tonne-Scale experiment. The Environmental Molecular Sciences facility (EMSL), a DOE user facility at PNNL, has the required mass spectroscopy instruments for making these isotopic measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR and for the development of the future separation technology required for the Tonne-Scale experiment. A sample of isotopically separated copper was provided by NID to PNNL for isotopic analysis as a test of the NID technology. The results of that analysis are reported here.

  16. Substructure in clusters containing wide-angle tailed radio galaxies. I. New redshifts

    E-Print Network [OSTI]

    Pinkney, J C; Ledlow, M J; Gómez, P L; Hill, J M; Pinkney, Jason; Burns, Jack O.; Ledlow, Michael J.; Gomez, Percy L.; Hill, John M.

    2000-01-01T23:59:59.000Z

    We present new redshifts and positions for 635 galaxies in nine rich clusters containing Wide-Angle Tailed (WAT) radio galaxies. Combined with existing data, we now have a sample of 18 WAT-containing clusters with more than 10 redshifts. This sample contains a substantial portion of the WAT clusters in the VLA 20 cm survey of Abell clusters, including 75% of WAT clusters in the complete survey (z0.09. It is a representative sample which should not contain biases other than selection by radio morphology. We graphically present the new data using histograms and sky maps. A semi-automated procedure is used to search for emission lines in the spectra in order to add and verify galaxy redshifts. We find that the average apparent fraction of emission line galaxies is about 9% in both the clusters and the field. We investigate the magnitude completeness of our redshift surveys with CCD data for a test case, Abell 690. This case indicates that our galaxy target lists are deeper than the detection limit of a typical M...

  17. Sample holder with optical features

    DOE Patents [OSTI]

    Milas, Mirko; Zhu, Yimei; Rameau, Jonathan David

    2013-07-30T23:59:59.000Z

    A sample holder for holding a sample to be observed for research purposes, particularly in a transmission electron microscope (TEM), generally includes an external alignment part for directing a light beam in a predetermined beam direction, a sample holder body in optical communication with the external alignment part and a sample support member disposed at a distal end of the sample holder body opposite the external alignment part for holding a sample to be analyzed. The sample holder body defines an internal conduit for the light beam and the sample support member includes a light beam positioner for directing the light beam between the sample holder body and the sample held by the sample support member.

  18. THE EVOLUTION OF DUSTY STAR FORMATION IN GALAXY CLUSTERS TO z = 1: SPITZER INFRARED OBSERVATIONS OF THE FIRST RED-SEQUENCE CLUSTER SURVEY

    SciTech Connect (OSTI)

    Webb, T. M. A.; O'Donnell, D.; Coppin, Kristen; Faloon, Ashley; Geach, James E.; Noble, Allison [McGill University, 3600 rue University, Montreal, QC, H3A 2T8 (Canada); Yee, H. K. C. [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George St., Toronto, ON, M5S 3H4 (Canada); Gilbank, David [South African Astronomical Observatory, P.O. Box 9, Observatory, 7935 (South Africa); Ellingson, Erica [Department of Astrophysical and Planetary Sciences, University of Colorado at Boulder, Boulder, CO 80309 (United States); Gladders, Mike [Department of Astronomy and Astrophysics, University of Chicago, 5640 S. Ellis Ave., Chicago, IL 60637 (United States); Muzzin, Adam [Leiden Observatory, University of Leiden, Niels Bohrweg 2, NL-2333 CA, Leiden (Netherlands); Wilson, Gillian [Department of Physics and Astronomy, University of California at Riverside, 900 University Avenue, Riverside, CA 92521 (United States); Yan, Renbin [Center for Cosmology and Particle Physics, Department of Physics, New York University, 4 Washington Place, New York, NY 10003 (United States)

    2013-10-01T23:59:59.000Z

    We present the results of an infrared (IR) study of high-redshift galaxy clusters with the MIPS camera on board the Spitzer Space Telescope. We have assembled a sample of 42 clusters from the Red-Sequence Cluster Survey-1 over the redshift range 0.3 < z < 1.0 and spanning an approximate range in mass of 10{sup 14-15} M {sub ?}. We statistically measure the number of IR-luminous galaxies in clusters above a fixed inferred IR luminosity of 2 × 10{sup 11} M {sub ?}, assuming a star forming galaxy template, per unit cluster mass and find it increases to higher redshift. Fitting a simple power-law we measure evolution of (1 + z){sup 5.1±1.9} over the range 0.3 < z < 1.0. These results are tied to the adoption of a single star forming galaxy template; the presence of active galactic nuclei, and an evolution in their relative contribution to the mid-IR galaxy emission, will alter the overall number counts per cluster and their rate of evolution. Under the star formation assumption we infer the approximate total star formation rate per unit cluster mass (?SFR/M {sub cluster}). The evolution is similar, with ?SFR/M {sub cluster} ? (1 + z){sup 5.4±1.9}. We show that this can be accounted for by the evolution of the IR-bright field population over the same redshift range; that is, the evolution can be attributed entirely to the change in the in-falling field galaxy population. We show that the ?SFR/M {sub cluster} (binned over all redshift) decreases with increasing cluster mass with a slope (?SFR/M{sub cluster}?M{sub cluster}{sup -1.5±0.4}) consistent with the dependence of the stellar-to-total mass per unit cluster mass seen locally. The inferred star formation seen here could produce ?5%-10% of the total stellar mass in massive clusters at z = 0, but we cannot constrain the descendant population, nor how rapidly the star-formation must shut-down once the galaxies have entered the cluster environment. Finally, we show a clear decrease in the number of IR-bright galaxies per unit optical galaxy in the cluster cores, confirming star formation continues to avoid the highest density regions of the universe at z ? 0.75 (the average redshift of the high-redshift clusters). While several previous studies appear to show enhanced star formation in high-redshift clusters relative to the field we note that these papers have not accounted for the overall increase in galaxy or dark matter density at the location of clusters. Once this is done, clusters at z ? 0.75 have the same or less star formation per unit mass or galaxy as the field.

  19. Interpreting the Clustering of Distant Red Galaxies

    SciTech Connect (OSTI)

    Tinker, Jeremy L.; /BCCP, Berkeley; Wechsler, Risa H.; /KIPAC, Menlo Park /SLAC; Zheng, Zheng; /Princeton, Inst. Advanced Study

    2009-08-03T23:59:59.000Z

    We analyze the angular clustering of z {approx} 2.3 distant red galaxies (DRGs) measured by Quadri et al. (2008). We find that, with robust estimates of the measurement errors and realistic halo occupation distribution modeling, the measured clustering can be well fit within standard halo occupation models, in contrast to previous results. However, in order to fit the strong break in w({theta}) at {theta} = 10{double_prime}, nearly all satellite galaxies in the DRG luminosity range are required to be DRGs. Within this luminosity-threshold sample, the fraction of galaxies that are DRGs is {approx} 44%, implying that the formation of DRGs is more efficient for satellite galaxies than for central galaxies. Despite the evolved stellar populations contained within DRGs at z = 2.3, 90% of satellite galaxies in the DRG luminosity range have been accreted within 500 Myr. Thus, satellite DRGs must have known they would become satellites well before the time of their accretion. This implies that the formation of DRGs correlates with large-scale environment at fixed halo mass, although the large-scale bias of DRGs can be well fit without such assumptions. Further data are required to resolve this issue. Using the observational estimate that {approx} 30% of DRGs have no ongoing star formation, we infer a timescale for star formation quenching for satellite galaxies of 450 Myr, although the uncertainty on this number is large. However, unless all non-star forming satellite DRGs were quenched before accretion, the quenching timescale is significantly shorter than z {approx} 0 estimates. Down to the completeness limit of the Quadri et al sample, we find that the halo masses of central DRGs are {approx} 50% higher than non-DRGs in the same luminosity range, but at the highest halo masses the central galaxies are DRGs only {approx} 2/3 of the time.

  20. ROSAT PSPC Observations of the Richest ($R \\geq 2$) ACO Clusters

    E-Print Network [OSTI]

    Laurence P. David; William Forman; Christine Jones

    1999-02-08T23:59:59.000Z

    We have compiled an X-ray catalog of optically selected rich clusters of galaxies observed by the PSPC during the pointed GO phase of the ROSAT mission. This paper contains a systematic X-ray analysis of 150 clusters with an optical richness classification of $R \\geq 2$ from the ACO catalog (Abell, Corwin, and Olowin 1989). All clusters were observed within 45' of the optical axis of the telescope during pointed PSPC observations. For each cluster, we calculate: the net 0.5-2.0 keV PSPC count rate (or $4 \\sigma$ upper limit) in a 1 Mpc radius aperture, 0.5-2.0 keV flux and luminosity, bolometric luminosity, and X-ray centroid. The cluster sample is then used to examine correlations between the X-ray and optical properties of clusters, derive the X-ray luminosity function of clusters with different optical classifications, and obtain a quantitative estimate of contamination (i.e, the fraction of clusters with an optical richness significantly overestimated due to interloping galaxies) in the ACO catalog.

  1. The matter distribution in z ~ 0.5 redshift clusters of galaxies. II : The link between dark and visible matter

    E-Print Network [OSTI]

    Soucail, Genevieve; Pointecouteau, Etienne; Arnaud, Monique; Limousin, Marceau

    2015-01-01T23:59:59.000Z

    We present an optical analysis of a sample of 11 clusters built from the EXCPRES sample of X-ray selected clusters at intermediate redshift (z ~ 0.5). With a careful selection of the background galaxies we provide the mass maps reconstructed from the weak lensing by the clusters. We compare them with the light distribution traced by the early-type galaxies selected along the red sequence for each cluster. The strong correlations between dark matter and galaxy distributions are confirmed, although some discrepancies arise, mostly for merging or perturbed clusters. The average M/L ratio of the clusters is found to be: M/L_r = 160 +/- 60 in solar units (with no evolutionary correction), in excellent agreement with similar previous studies. No strong evolutionary effects are identified even if the small sample size reduces the significance of the result. We also provide a individual analysis of each cluster in the sample with a comparison between the dark matter, the galaxies and the gas distributions. Some of th...

  2. Three gravitationally lensed supernovae behind clash galaxy clusters

    SciTech Connect (OSTI)

    Patel, Brandon; McCully, Curtis; Jha, Saurabh W.; Holoien, Thomas W.-S. [Department of Physics and Astronomy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (United States); Rodney, Steven A.; Jones, David O.; Graur, Or; Riess, Adam G. [Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, MD 21218 (United States); Merten, Julian [Jet Propulsion Laboratory, California Institute of Technology, MS 169-327, Pasadena, CA 91109 (United States); Zitrin, Adi [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, MS 249-17, Pasadena, CA 91125 (United States); Matheson, Thomas [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Sako, Masao [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104 (United States); Postman, Marc; Coe, Dan; Bradley, Larry [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21208 (United States); Bartelmann, Matthias [Institut für Theoretische Astrophysik, Universität Heidelberg, Zentrum für Astronomie, Philosophenweg 12, D-69120 Heidelberg (Germany); Balestra, Italo [INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, I-34131 Trieste (Italy); Benítez, Narciso [Instituto de Astrofísica de Andalucía (CSIC), Camino Bajo de Huétor 24, E-18008 Granada (Spain); Bouwens, Rychard [Leiden Observatory, Leiden University, NL-2300 RA Leiden (Netherlands); Broadhurst, Tom, E-mail: bpatel02@physics.rutgers.edu [Department of Theoretical Physics, University of the Basque Country, P.O. Box 644, E-48080 Bilbao (Spain); and others

    2014-05-01T23:59:59.000Z

    We report observations of three gravitationally lensed supernovae (SNe) in the Cluster Lensing And Supernova survey with Hubble (CLASH) Multi-Cycle Treasury program. These objects, SN CLO12Car (z = 1.28), SN CLN12Did (z = 0.85), and SN CLA11Tib (z = 1.14), are located behind three different clusters, MACSJ1720.2+3536 (z = 0.391), RXJ1532.9+3021 (z = 0.345), and A383 (z = 0.187), respectively. Each SN was detected in Hubble Space Telescope optical and infrared images. Based on photometric classification, we find that SNe CLO12Car and CLN12Did are likely to be Type Ia supernovae (SNe Ia), while the classification of SN CLA11Tib is inconclusive. Using multi-color light-curve fits to determine a standardized SN Ia luminosity distance, we infer that SN CLO12Car was ?1.0 ± 0.2 mag brighter than field SNe Ia at a similar redshift and ascribe this to gravitational lens magnification. Similarly, SN CLN12Did is ?0.2 ± 0.2 mag brighter than field SNe Ia. We derive independent estimates of the predicted magnification from CLASH strong+weak-lensing maps of the clusters (in magnitude units, 2.5 log{sub 10}?): 0.83 ± 0.16 mag for SN CLO12Car, 0.28 ± 0.08 mag for SN CLN12Did, and 0.43 ± 0.11 mag for SN CLA11Tib. The two SNe Ia provide a new test of the cluster lens model predictions: we find that the magnifications based on the SN Ia brightness and those predicted by the lens maps are consistent. Our results herald the promise of future observations of samples of cluster-lensed SNe Ia (from the ground or space) to help illuminate the dark-matter distribution in clusters of galaxies, through the direct determination of absolute magnifications.

  3. THE CLUSTERED NATURE OF STAR FORMATION. PRE-MAIN-SEQUENCE CLUSTERS IN THE STAR-FORMING REGION NGC 602/N90 IN THE SMALL MAGELLANIC CLOUD

    SciTech Connect (OSTI)

    Gouliermis, Dimitrios A.; Gennaro, Mario [Max Planck Institute for Astronomy, Koenigstuhl 17, 69117 Heidelberg (Germany); Schmeja, Stefan [Zentrum fuer Astronomie der Universitaet Heidelberg, Institut fuer Theoretische Astrophysik, Albert-Ueberle-Str. 2, 69120 Heidelberg (Germany); Dolphin, Andrew E. [Raytheon Company, P.O. Box 11337, Tucson, AZ 85734 (United States); Tognelli, Emanuele; Prada Moroni, Pier Giorgio [Dipartimento di Fisica 'Enrico Fermi', Universita di Pisa, largo Pontecorvo 3, Pisa I-56127 (Italy)

    2012-03-20T23:59:59.000Z

    Located at the tip of the wing of the Small Magellanic Cloud (SMC), the star-forming region NGC 602/N90 is characterized by the H II nebular ring N90 and the young cluster of pre-main-sequence (PMS) and early-type main-sequence stars NGC 602, located in the central area of the ring. We present a thorough cluster analysis of the stellar sample identified with Hubble Space Telescope/Advanced Camera for Surveys in the region. We show that apart from the central cluster low-mass PMS stars are congregated in 13 additional small, compact sub-clusters at the periphery of NGC 602, identified in terms of their higher stellar density with respect to the average background density derived from star counts. We find that the spatial distribution of the PMS stars is bimodal, with an unusually large fraction ({approx}60%) of the total population being clustered, while the remaining is diffusely distributed in the intercluster area, covering the whole central part of the region. From the corresponding color-magnitude diagrams we disentangle an age difference of {approx}2.5 Myr between NGC 602 and the compact sub-clusters, which appear younger, on the basis of comparison of the brighter PMS stars with evolutionary models, which we accurately calculated for the metal abundance of the SMC. The diffuse PMS population appears to host stars as old as those in NGC 602. Almost all detected PMS sub-clusters appear to be centrally concentrated. When the complete PMS stellar sample, including both clustered and diffused stars, is considered in our cluster analysis, it appears as a single centrally concentrated stellar agglomeration, covering the whole central area of the region. Considering also the hot massive stars of the system, we find evidence that this agglomeration is hierarchically structured. Based on our findings, we propose a scenario according to which the region NGC 602/N90 experiences an active clustered star formation for the last {approx}5 Myr. The central cluster NGC 602 was formed first and rapidly started dissolving into its immediate ambient environment, possibly ejecting also massive stars found away from its center. Star formation continued in sub-clusters of a larger stellar agglomeration, introducing an age spread of the order of 2.5 Myr among the PMS populations.

  4. Sample Environment Plans and Progress

    E-Print Network [OSTI]

    Pennycook, Steve

    Sample Environment Plans and Progress at the SNS & HFIR SNS HFIR User Group Meeting American Conference on Neutron Scattering Ottawa, Canada June 26 ­ 30, 2010 Lou Santodonato Sample Environment Group our sample environment capabilities Feedback SHUG meetings User surveys Sample Environment Steering

  5. Fluid sampling tool

    DOE Patents [OSTI]

    Johnston, Roger G. (Los Alamos, NM); Garcia, Anthony R. E. (Espanola, NM); Martinez, Ronald K. (Santa Cruz, NM)

    2001-09-25T23:59:59.000Z

    The invention includes a rotatable tool for collecting fluid through the wall of a container. The tool includes a fluid collection section with a cylindrical shank having an end portion for drilling a hole in the container wall when the tool is rotated, and a threaded portion for tapping the hole in the container wall. A passageway in the shank in communication with at least one radial inlet hole in the drilling end and an opening at the end of the shank is adapted to receive fluid from the container. The tool also includes a cylindrical chamber affixed to the end of the shank opposite to the drilling portion thereof for receiving and storing fluid passing through the passageway. The tool also includes a flexible, deformable gasket that provides a fluid-tight chamber to confine kerf generated during the drilling and tapping of the hole. The invention also includes a fluid extractor section for extracting fluid samples from the fluid collecting section.

  6. KEYWORDS: geospatial clustering, web service, Web GIS, spatial data mining, clustering 1 INTRODUCTION

    E-Print Network [OSTI]

    1 KEYWORDS: geospatial clustering, web service, Web GIS, spatial data mining, clustering 1 in disease surveillance, spatial epidemiology, population genetics, landscape ecology, crime analysis

  7. Ionization of Water Clusters is Mediated by Exciton Energy Transfer from Argon Clusters

    SciTech Connect (OSTI)

    Golan, Amir; Ahmed, Musahid

    2012-01-25T23:59:59.000Z

    The exciton energy deposited in an argon cluster, (Arn ,< n=20>) using VUV radiation is transferred to softly ionize doped water clusters, ((H2O)n, n=1-9) leading to the formation of non-fragmented clusters. Following the initial excitation, electronic energy is channeled to ionize the doped water cluster while evaporating the Ar shell, allowing identification of fragmented and complete water cluster ions. Examination of the photoionization efficiency curve shows that cluster evaporation from excitons located above 12.6 eV are not enough to cool the energized water cluster ion, and leads to their dissociation to (H2O)n-2H+ (protonated) clusters.

  8. Bayesian Model Based Clustering Procedures John W. Lau

    E-Print Network [OSTI]

    Green, Peter

    of classical approaches, such as hierarchical clustering and K-means clustering procedures, Bayesian a comparison of the statistical performance of the (approximate) optimal clustering with earlier methods

  9. AGN Physics from QSO Clustering

    E-Print Network [OSTI]

    Scott Croom; Brian Boyle; Tom Shanks; Phil Outram; Robert Smith; Lance Miller; Nicola Loaring; Suzanne Kenyon; Warrick Couch

    2003-10-20T23:59:59.000Z

    We review the current status of QSO clustering measurements, particular with respect to their relevance in understanding AGN physics. Measurements based on the 2dF QSO Redshift Survey (2QZ) find a scale length for QSO clustering of s_0=5.76(+0.17-0.27) h-1 Mpc at a redshift ~1.5, very similar to low redshift galaxies. There is no evidence of evolution in the clustering of QSOs from z~0.5 to z~2.2. This lack of evolution and low clustering amplitude suggests a short life time for AGN activity of the order ~10^6-10^7 years. Large surveys such at the 2QZ and SDSS also allow the the study of QSO environments in 3D for the first time (at least at low redshift), early results from this work seem to show no difference between the environments of QSOs and normal galaxies. Future studies e.g. measuring clustering as a function of black hole mass, and deep QSO surveys should provide further insight into the formation and evolution of AGN.

  10. The Color-Magnitude Effect in Early-Type Cluster Galaxies

    E-Print Network [OSTI]

    Omar Lopez-Cruz; Wayne A. Barkhouse; H. K. C. Yee

    2004-07-30T23:59:59.000Z

    We present the analysis of the color-magnitude relation (CMR) for a sample of 57 X-ray detected Abell clusters within the redshift interval 0.02 <= z <= 0.18. We use the B-R vs R color-magnitude plane to establish that the CMR is present in all our low-redshift clusters and can be parameterized by a single straight line.We find that the CMRs for this large cluster sample of different richness and cluster types are consistent with having universal properties. The k-corrected color of the individual CMRs in the sample at a fixed absolute magnitude have a small intrinsic dispersion of ~0.05 mag. The slope of the CMR is consistent with being the same for all clusters, with the variations entirely accountable by filter band shifting effects. We determine the mean of the dispersion of the 57 CMRs to be 0.074 mag, with a small rms scatter of 0.026 mag. However, a modest amount of the dispersion arises from photometric measurement errors and possible background cluster superpositions; and the derived mean dispersion is an upper limit. Models which explain the CMR in terms of metallicity and passive evolution can naturally reproduce the observed behavior of the CMR in this paper. The observed properties of the CMR are consistent with models in which the last episode of significant star formation in cluster early-type galaxies occurred significantly more than ~3 Gyr ago, and that the core set of early-type galaxies in clusters were formed more than 7 Gyr ago. (abridged)

  11. Nuclear Star Clusters and Bulges

    E-Print Network [OSTI]

    Cole, David R

    2015-01-01T23:59:59.000Z

    Nuclear star clusters are among the densest stellar systems known and are common in both early- and late-type galaxies. They exhibit scaling relations with their host galaxy which may be related to those of supermassive black holes. These may therefore help us to unravel the complex physical processes occurring at the centres of galaxies. The properties of nuclear stellar systems suggest that their formation requires both dissipational and dissipationless processes. They have stellar populations of different ages, from stars as old as their host galaxy to young stars formed in the last 100 Myr. Therefore star formation must be happening either directly in the nuclear star cluster or in its vicinity. The secular processes that fuel the formation of pseudobulges very likely also contributes to nuclear star cluster growth.

  12. Are Cluster Magnetic Fields Primordial ?

    E-Print Network [OSTI]

    Robi Banerjee; Karsten Jedamzik

    2004-09-07T23:59:59.000Z

    We present results of a detailed and fully non-linear numerical and analytical investigation of magnetic field evolution from the very earliest cosmic epochs to the present. We find that, under reasonable assumptions concerning the efficiency of a putative magnetogenesis era during cosmic phase transitions, surprisingly strong magnetic fields 10^{-13} - 10^{-11} Gauss, on comparatively small scales 100 pc - 10 kpc may survive to the present. Building on prior work on the evolution of magnetic fields during the course of gravitational collapse of a cluster, which indicates that pre-collapse fields of 4\\times 10^{-12} Gauss extant on small scales may suffice to produce clusters with acceptable Faraday rotation measures, we question the widely hold view that cluster magnetic fields may not be entirely of primordial origin.

  13. Cosmological constraints from the correlation function of galaxy clusters

    E-Print Network [OSTI]

    James Robinson

    2000-04-03T23:59:59.000Z

    I compare various semi-analytic models for the bias of dark matter halos with halo clustering properties observed in recent numerical simulations. The best fitting model is one based on the collapse of ellipsoidal perturbations proposed by Sheth, Mo & Tormen (1999), which fits the halo correlation length to better than 8 per cent accuracy. Using this model, I confirm that the correlation length of clusters of a given separation depends primarily on the shape and amplitude of mass fluctuations in the universe, and is almost independent of other cosmological parameters. Current observational uncertainties make it difficult to draw robust conclusions, but for illustrative purposes I discuss the constraints on the mass power spectrum which are implied by recent analyses of the APM cluster sample. I also discuss the prospects for improving these constraints using future surveys such as the Sloan Digital Sky Survey. Finally, I show how these constraints can be combined with observations of the cluster number abundance to place strong limits on the matter density of the universe.

  14. Specified assurance level sampling procedure

    SciTech Connect (OSTI)

    Willner, O.

    1980-11-01T23:59:59.000Z

    In the nuclear industry design specifications for certain quality characteristics require that the final product be inspected by a sampling plan which can demonstrate product conformance to stated assurance levels. The Specified Assurance Level (SAL) Sampling Procedure has been developed to permit the direct selection of attribute sampling plans which can meet commonly used assurance levels. The SAL procedure contains sampling plans which yield the minimum sample size at stated assurance levels. The SAL procedure also provides sampling plans with acceptance numbers ranging from 0 to 10, thus, making available to the user a wide choice of plans all designed to comply with a stated assurance level.

  15. Sampling for Bacteria in Wells 

    E-Print Network [OSTI]

    Lesikar, Bruce J.

    2001-11-15T23:59:59.000Z

    Sampling for Bacteria in Wells E-126 11/01 Water samples for bacteria tests must always be col- lected in a sterile container. The procedure for collect- ing a water sample is as follows: 1. Obtain a sterile container from a Health Department... immediately after collecting water sample. Refrigerate the sample and transport it to the laborato- ry (in an ice chest) as soon after collection as possible (six hours is best, but up to 30 hours). Many labs will not accept bacteria samples on Friday so check...

  16. The Herschel Virgo Cluster Survey XVI: a cluster inventory

    E-Print Network [OSTI]

    Davies, J I; Baes, M; Bendo, G J; Clemens, M; De Looze, I; Alighieri, S di Serego; Fritz, J; Fuller, C; Pappalardo, C; Hughes, T M; Madden, S; Smith, M W L; Verstappen, J; Vlahakis, C

    2013-01-01T23:59:59.000Z

    Herschel FIR observations are used to construct Virgo cluster galaxy luminosity functions and to show that the cluster lacks the very bright and the numerous faint sources detected in field galaxy surveys. The far-infrared SEDs are fitted to obtain dust masses and temperatures and the dust mass function. The cluster is over dense in dust by about a factor of 100 compared to the field. The same emissivity (beta) temperature relation applies for different galaxies as that found for different regions of M31. We use optical and HI data to show that Virgo is over dense in stars and atomic gas by about a factor of 100 and 20 respectively. Metallicity values are used to measure the mass of metals in the gas phase. The mean metallicity is about 0.7 solar and 50% of the metals are in the dust. For the cluster as a whole the mass density of stars in galaxies is 8 times that of the gas and the gas mass density is 130 times that of the metals. We use our data to consider the chemical evolution of the individual galaxies,...

  17. How Many Clusters? Which Clustering Method? Answers Via

    E-Print Network [OSTI]

    Raftery, Adrian

    much more closely than single-link (nearest-neighbour) or standard k-means, in the absence of any on the Bayesian information criterion (BIC); unlike significance tests, this allows comparison of more than two a clustering methodology based on multivariate normal mixtures in which the BIC is used for direct comparison

  18. Perspectives for logistics clusters development in Russia

    E-Print Network [OSTI]

    Tantsuyev, Andriy

    2012-01-01T23:59:59.000Z

    This thesis is a normative work aimed at identifying locations in Russia with high, medium and unclear potentials for logistics cluster development. As a framework this work uses four different models of logistics clusters: ...

  19. Agglomerative Clustering via Maximum Incremental Path Integral

    E-Print Network [OSTI]

    Wang, Xiaogang

    clusters into small ones. Numerous algorithms have been proposed, such as k-means [2], spectral clustering of the algorithm based on absorbing random walk is provided. Experimental comparison on toy data and imagery data

  20. Performance Characterization of Clustering Algorithms for Colour Image Segmentation

    E-Print Network [OSTI]

    Whelan, Paul F.

    techniques (K-Means clustering, Fuzzy C- Means clustering and Adaptive K-Means clustering) that are applied algorithms: K-Means, Fuzzy C-Means and Adaptive K-Means (also called clustering by competitive agglomeration

  1. PageRank Based Clustering of Hypertext Document Collections

    E-Print Network [OSTI]

    Avrachenkov, Konstantin

    are K-means clustering, Informa- tion Bottleneck based clustering and Contextual Document Clustering with high modularity and coverage. The comparison of the PRC algorithm with two content based clustering

  2. Radio Galaxies in Cooling Cores: Insights from a Complete Sample

    E-Print Network [OSTI]

    J. A. Eilek; F. N. Owen

    2006-12-04T23:59:59.000Z

    We have observed a new, complete, cooling-core sample with the VLA, in order to understand how the massive black hole in the central galaxy interacts with the local cluster plasma. We find that every cooling core is currently being energized by an active radio jet, which has probably been destabilized by its interaction with the cooling core. We argue that current models of cooling-core radio galaxies need to be improved before they can be used to determine the rate at which the jet is heating the cooling core. We also argue that the extended radio haloes we see in many cooling-core clusters need extended, in situ re-energization, which cannot be supplied solely by the central galaxy.

  3. 3 - DJ : sampling as design

    E-Print Network [OSTI]

    Patel, Sayjel Vijay

    2015-01-01T23:59:59.000Z

    3D Sampling is introduced as a new spatial craft that can be applied to architectural design, akin to how sampling is applied in the field of electronic music. Through the development of 3-DJ, a prototype design software, ...

  4. Cluster Dynamics in a Circulating Fluidized Bed

    SciTech Connect (OSTI)

    Guenther, C.P.; Breault, R.W.

    2006-11-01T23:59:59.000Z

    A common hydrodynamic feature in industrial scale circulating fluidized beds is the presence of clusters. The continuous formation and destruction of clusters strongly influences particle hold-up, pressure drop, heat transfer at the wall, and mixing. In this paper fiber optic data is analyzed using discrete wavelet analysis to characterize the dynamic behavior of clusters. Five radial positions at three different axial locations under five different operating were analyzed using discrete wavelets. Results are summarized with respect to cluster size and frequency.

  5. Effervescent heating: constraints from nearby cooling flow clusters observed with XMM-Newton

    E-Print Network [OSTI]

    Rocco Piffaretti; Jelle Kaastra

    2006-05-15T23:59:59.000Z

    We have used deprojected radial density and temperature profiles of a sample of 16 nearby CF clusters observed with XMM-Newton to test whether the effervescent heating model can satisfactorily explain the dynamics of CF clusters. For each cluster we derived the required extra heating as a function of cluster-centric distance for various values of the unknown parameters $\\dot M$ (mass deposition rate) and $f_c$ (conduction efficiency). We fitted the extra heating curve using the AGN effervescent heating function and derived the AGN parameters $L$ (the time-averaged luminosity) and $r_0$ (the scale radius where the bubbles start rising in the ICM). While we do not find any solution with the effervescent heating model for only one object, we do show that AGN and conduction heating are not cooperating effectively for half of the objects in our sample. For most of the clusters we find that, when a comparison is possible, the derived AGN scale radius $r_0$ and the observed AGN jet extension have the same order of magnitude. The AGN luminosities required to balance radiative losses are substantially lowered if the fact that the AGN deposits energy within a finite volume is taken into account. For the Virgo cluster, we find that the AGN power derived from the effervescent heating model is in good agreement with the observed jet power.

  6. Observation of neutral sulfuric acid-amine containing clusters in laboratory and ambient measurements

    SciTech Connect (OSTI)

    Kuang C.; Zhao, J.; Smith, J. N.; Eisele, F. L.; Chen, M.; McMurry, P. H.

    2011-11-02T23:59:59.000Z

    Recent ab initio calculations showed that amines can enhance atmospheric sulfuric acid-water nucleation more effectively than ammonia, and this prediction has been substantiated in laboratory measurements. Laboratory studies have also shown that amines can effectively displace ammonia in several types of ammonium clusters. However, the roles of amines in cluster formation and growth at a microscopic molecular scale (from molecular sizes up to 2 nm) have not yet been well understood. Processes that must be understood include the incorporation of amines into sulfuric acid clusters and the formation of organic salts in freshly nucleated particles, which contributes significantly to particle growth rates. We report the first laboratory and ambient measurements of neutral sulfuric acid-amine clusters using the Cluster CIMS, a recently-developed mass spectrometer designed for measuring neutral clusters formed in the atmosphere during nucleation. An experimental technique, which we refer to as Semi-Ambient Signal Amplification (SASA), was employed. Sulfuric acid was added to ambient air, and the concentrations and composition of clusters in this mixture were analyzed by the Cluster CIMS. This experimental approach led to significantly higher cluster concentrations than are normally found in ambient air, thereby increasing signal-to-noise levels and allowing us to study reactions between gas phase species in ambient air and sulfuric acid containing clusters. Mass peaks corresponding to clusters containing four H{sub 2}SO{sub 4} molecules and one amine molecule were clearly observed, with the most abundant sulfuric acid-amine clusters being those containing a C2- or C4-amine (i.e. amines with masses of 45 and 73 amu). Evidence for C3- and C5-amines (i.e. amines with masses of 59 and 87 amu) was also found, but their correlation with sulfuric acid tetramer was not as strong as was observed for the C2- and C4-amines. The formation mechanisms for those sulfuric acid-amine clusters were investigated by varying the residence time in the inlet. It was concluded that the amines react directly with neutral clusters and that ion-induced clustering of sulfuric acid cluster ions with amines was not a dominant process. Results from ambient measurements using the Cluster CIMS without addition of sulfuric acid have shown that the sulfuric acid-amine clusters were reasonably well correlated with sulfuric acid tetramer and consistent with the SASA experiments at the same Boulder sampling site. Also, clusters that contain C2- or C4-amines were more abundant and better correlated with sulfuric acid tetramer than other types of amine containing clusters. However, ambient measurements of sulfuric acid-amine clusters remain difficult and highly uncertain because their concentrations are only slightly above background levels, even during nucleation events.

  7. Sampling for Bacteria in Wells

    E-Print Network [OSTI]

    Lesikar, Bruce J.

    2001-11-15T23:59:59.000Z

    Sampling for Bacteria in Wells E-126 11/01 Water samples for bacteria tests must always be col- lected in a sterile container. The procedure for collect- ing a water sample is as follows: 1. Obtain a sterile container from a Health Department...

  8. ON ADAPTIVE SAMPLING Philippe Flajolet

    E-Print Network [OSTI]

    Flajolet, Philippe

    . We analyze the storage/accuracy trade--off of an adaptive sampling algorithm due to Wegman that makes. Wegman [11] has proposed an interesting alternative solution to that problem based on Adaptive Sampling 4. 2 Wegman's Adaptive Sampling Method The problem discussed here is the following. We are given

  9. Spectral Thompson Sampling Tomas Kocak

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Spectral Thompson Sampling Tom´as Koc´ak SequeL team INRIA Lille - Nord Europe France Michal Valko Thompson Sampling (TS) has surged a lot of interest due to its good empirical performance, in particular that our algorithm is com- petitive on both synthetic and real-world data. 1 Introduction Thompson Sampling

  10. An Improved Cluster Richness Estimator

    SciTech Connect (OSTI)

    Rozo, Eduardo; /Ohio State U.; Rykoff, Eli S.; /UC, Santa Barbara; Koester, Benjamin P.; /Chicago U. /KICP, Chicago; McKay, Timothy; /Michigan U.; Hao, Jiangang; /Michigan U.; Evrard, August; /Michigan U.; Wechsler, Risa H.; /SLAC; Hansen, Sarah; /Chicago U. /KICP, Chicago; Sheldon, Erin; /New York U.; Johnston, David; /Houston U.; Becker, Matthew R.; /Chicago U. /KICP, Chicago; Annis, James T.; /Fermilab; Bleem, Lindsey; /Chicago U.; Scranton, Ryan; /Pittsburgh U.

    2009-08-03T23:59:59.000Z

    Minimizing the scatter between cluster mass and accessible observables is an important goal for cluster cosmology. In this work, we introduce a new matched filter richness estimator, and test its performance using the maxBCG cluster catalog. Our new estimator significantly reduces the variance in the L{sub X}-richness relation, from {sigma}{sub lnL{sub X}}{sup 2} = (0.86 {+-} 0.02){sup 2} to {sigma}{sub lnL{sub X}}{sup 2} = (0.69 {+-} 0.02){sup 2}. Relative to the maxBCG richness estimate, it also removes the strong redshift dependence of the richness scaling relations, and is significantly more robust to photometric and redshift errors. These improvements are largely due to our more sophisticated treatment of galaxy color data. We also demonstrate the scatter in the L{sub X}-richness relation depends on the aperture used to estimate cluster richness, and introduce a novel approach for optimizing said aperture which can be easily generalized to other mass tracers.

  11. DESIGN OF CLUSTERED SUPERSCALAR MICROARCHITECTURES

    E-Print Network [OSTI]

    Parcerisa, Joan-Manuel

    DESIGN OF CLUSTERED SUPERSCALAR MICROARCHITECTURES Joan-Manuel Parcerisa Departament d'Arquitectura SUPERSCALAR MICROARCHITECTURES Joan-Manuel Parcerisa Departament d'Arquitectura de Computadors Universitat après tantes coses sobre l'ofici de la recerca, i sobre l'arquitectura de computadors al llarg d

  12. COSMOS Cluster 3 Summer 2010

    E-Print Network [OSTI]

    Russell, Lynn

    COSMOS Cluster 3 Summer 2010 Clouds in a Glass of Root Beer Instructor: Prof. Lynn Russell Teaching and Physics J.H. Seinfeld and S.N. Pandis, 1997 Clouds in a Glass of Beer: Simple Experiments in Atmospheric) to observe the difference in carbonation of water and root beer 2) to form clouds in root beer using

  13. Gravitational `Convergence' and Cluster Masses

    E-Print Network [OSTI]

    Tom Broadhurst

    1995-12-01T23:59:59.000Z

    Two colour photometry of the cluster A1689 reveals a `relative magnification-bias' between lensed blue and red background galaxies, arising from a dependence of the faint galaxy count-slope on colour. The colour distribution is skewed blueward of the far field, allowing us to measure the cluster magnification and to understand the notorious blueness of large arcs. We show that the magnification information can be combined with the usual image distortion measurements to isolate the local `convergence' component of lensing and hence derive the projected mass. This is achieved through a simple local relation between the convergence and the observables, which can be applied generally over the surface a cluster. In the weak lensing limit, the convergence reduces to a dependence on the magnification alone, so that in the outskirts of clusters the surface-density of matter is obtained directly from the surface-density of background galaxies. Hence, useful lensing work requires colour information but not necessarily good seeing. Interestingly, convergence varies slowly at high redshift, saturating at a level depending on the Horizon distance, allowing a useful model-independent measurement of the Global Geometry.

  14. Cold Fronts in CDM clusters

    E-Print Network [OSTI]

    Daisuke Nagai; Andrey V. Kravtsov

    2003-01-08T23:59:59.000Z

    Recently, high-resolution Chandra observations revealed the existence of very sharp features in the X-ray surface brightness and temperature maps of several clusters (Vikhlinin et. al., 2001). These features, called ``cold fronts'', are characterized by an increase in surface brightness by a factor >2 over 10-50 kpc, accompanied by a drop in temperature of a similar magnitude. The existence of such sharp gradients can be used to put interesting constraints on the physics of the intracluster medium (ICM), if their mechanism and longevity are well understood. Here, we present results of a search for cold fronts in high-resolution simulations of galaxy clusters in cold dark matter (CDM) models. We show that sharp gradients with properties similar to those of observed cold fronts naturally arise in cluster mergers when the shocks heat gas surrounding the merging sub-cluster, while its dense core remains relatively cold. The compression induced by supersonic motions and shock heating during the merger enhance the amplitude of gas density and temperature gradients across the front. Our results indicate that cold fronts are non-equilibrium transient phenomena and can be observed for a period of less than a billion years. We show that the velocity and density fields of gas surrounding the cold front can be very irregular which would complicate analyses aiming to put constraints on the physical conditions of the intracluster medium in the vicinity of the front.

  15. Modeling the Energy Efficiency of Heterogeneous Clusters

    E-Print Network [OSTI]

    Teo, Yong-Meng

    are an alternative for energy-efficient clusters [18], [20], [23]. On the contrary, other researchersModeling the Energy Efficiency of Heterogeneous Clusters Lavanya Ramapantulu, Bogdan Marius Tudor analyze the energy efficiency of mixing high-performance and low-power nodes in a cluster. Using a model

  16. Clustering with the Fisher Score Koji Tsuda,

    E-Print Network [OSTI]

    clustering with the Fisher score, K-Means type methods are obviously inappropriate because they make use such as biological sequences [2] are especially challenging, because efficient clustering algorithms e.g. K-Means [6 of unnecessary nuisance dimensions. So K-Means type clustering [6] is obviously inappropriate because it takes

  17. Spectrophotometric indices and metal content of galactic globular clusters

    E-Print Network [OSTI]

    Covino, S; Pasinetti, L E; Covino, S; Galletti, S; Pasinetti, L E

    1995-01-01T23:59:59.000Z

    Spectrophotometric indices for 18 Galactic globular clusters, obtained from CCD observations and careful reductions, were used to determine reliable calibrations on metallicity [Fe/H]. The indices were measured in the bandpasses adopted by Burnstein et al. (\\cite{BFGK84}). Adding other observations of Burnstein et al. (\\cite{BFGK84}) we obtained our results from an homogeneous sample of indices for 26 globular clusters. Relations with indices defined by other Authors and with metallicity photometric indices or parameters were also computed. In each case the relations are quite satisfactory. Observational data were compared with synthetic indices derived from Buzzoni's (\\cite{B89}) models and detailed discussions were performed for Mg_2, Fe_{52}, and H_\\beta. The observational points seem to be systematically shifted with respect to the fiducial lines traced by the models. The scenario confirms that a certain degree of oxygen enhancement would be necessary to obtain a better agreement between observed data and...

  18. A good mass proxy for galaxy clusters with XMM-Newton

    SciTech Connect (OSTI)

    Zhao, Hai-Hui; Jia, Shu-Mei; Chen, Yong; Li, Cheng-Kui; Song, Li-Ming; Xie, Fei, E-mail: zhaohh@ihep.ac.cn [Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

    2013-12-01T23:59:59.000Z

    We use a sample of 39 galaxy clusters at redshift z < 0.1 observed by XMM-Newton to investigate the relations between X-ray observables and total mass. Based on central cooling time and central temperature drop, the clusters in this sample are divided into two groups: 25 cool core clusters and 14 non-cool core clusters, respectively. We study the scaling relations of L {sub bol}-M {sub 500}, M {sub 500}-T, M {sub 500}-M {sub g}, and M {sub 500}-Y {sub X}, and also the influences of cool core on these relations. The results show that the M {sub 500}-Y {sub X} relation has a slope close to the standard self-similar value, has the smallest scatter and does not vary with the cluster sample. Moreover, the M {sub 500}-Y {sub X} relation is not affected by the cool core. Thus, the parameter of Y{sub X} may be the best mass indicator.

  19. A Wide Field Hubble Space Telescope Study of the Cluster Cl0024+1654 at z=0.4 II: The Cluster Mass Distribution

    E-Print Network [OSTI]

    Jean-Paul Kneib; Patrick Hudelot; Richard S. Ellis; Tommaso Treu; Graham P. Smith; Phil Marshall; Oliver Czoske; Ian Smail; Priya Natarajan

    2003-07-15T23:59:59.000Z

    (abridged) We present a comprehensive lensing analysis of the rich cluster Cl0024+1654 based on panoramic sparse-sampled imaging conducted with HST. We demonstrate an ability to detect reliably weak lensing signals to a cluster radius of ~5 Mpc where the mean shear is around 1%. The projected mass distribution reveals a secondary concentration representing 30% of the overall cluster mass, which is also visible in the distribution of cluster member galaxies. We normalize the mass profile determined from the shear by assuming that background galaxies selected with I=23-26 have a redshift distribution statistically similar to that in the HDFs. Combining strong and weak constraints, we are able to probe the mass profile of the cluster on scales of 0.1 to 5 Mpc thus providing a valuable test of the universal form proposed by NFW on large scales. A generalized power law fit indicates a asymptotic density distribution with 3D slope larger than 2.4. An isothermal mass profile is therefore strongly rejected, whereas a NFW profile with M_200= 6.1+/-1 10^14 M_sun provides a good fit to the lensing data. We isolate cluster members according to their optical-near infrared colors; the red cluster light closely traces the dark matter with a mean mass-to-light ratio of M/L_K~ 40 M/L_sun. Similar profiles for mass and light on 1-5 Mpc scales are expected if cluster assembly is largely governed by infalling groups.

  20. Periodic Cluster Mutations and Related Integrable Maps

    E-Print Network [OSTI]

    Allan P Fordy

    2014-03-31T23:59:59.000Z

    One of the remarkable properties of cluster algebras is that any cluster, obtained from a sequence of mutations from an initial cluster, can be written as a Laurent polynomial in the initial cluster (known as the "Laurent phenomenon"). There are many nonlinear recurrences which exhibit the Laurent phenomenon and thus unexpectedly generate integer sequences. The mutation of a typical quiver will not generate a recurrence, but rather an erratic sequence of exchange relations. How do we "design" a quiver which gives rise to a given recurrence? A key role is played by the concept of "periodic cluster mutation", introduced in 2009. Each recurrence corresponds to a finite dimensional map. In the context of cluster mutations, these are called "cluster maps". What properties do cluster maps have? Are they integrable in some standard sense? In this review I describe how integrable maps arise in the context of cluster mutations. I first explain the concept of "periodic cluster mutation", giving some classification results. I then give a review of what is meant by an integrable map and apply this to cluster maps. Two classes of integrable maps are related to interesting monodromy problems, which generate interesting Poisson algebras of functions, used to prove complete integrability and a linearisation. A connections to the Hirota-Miwa equation is explained.

  1. Surface photometry of a sample of elliptical and S0 galaxies

    SciTech Connect (OSTI)

    De carvalho, R.R.; Da costa, L.N.; Djorgovski, S. (Observatorio Nacional do Brasil, Sao Cristovao (Brazil) California Institute of Technology, Pasadena (United States))

    1991-08-01T23:59:59.000Z

    The results are reported of surface photometry of 38 early-type galaxies, located mainly in the Fornax Cluster. Detailed comparisons with previously published work are given along with internal and external error estimates for all quantities, and some serious systematic discrepancies in the older aperture photometry of some of the galaxies in the present sample are pointed out. 15 refs.

  2. Cluster synchronization induced by one-node clusters in networks with asymmetric negative couplings

    SciTech Connect (OSTI)

    Zhang, Jianbao [School of Science, Hangzhou Dianzi University, Hangzhou 310018 (China)] [School of Science, Hangzhou Dianzi University, Hangzhou 310018 (China); Ma, Zhongjun, E-mail: mzj1234402@163.com [School of Mathematics and Computing Science, Guilin University of Electronic Technology, Guilin 541004 (China)] [School of Mathematics and Computing Science, Guilin University of Electronic Technology, Guilin 541004 (China); Zhang, Gang [College of Mathematics and Information Science, Hebei Normal University, Shijiazhuang 050024 (China)] [College of Mathematics and Information Science, Hebei Normal University, Shijiazhuang 050024 (China)

    2013-12-15T23:59:59.000Z

    This paper deals with the problem of cluster synchronization in networks with asymmetric negative couplings. By decomposing the coupling matrix into three matrices, and employing Lyapunov function method, sufficient conditions are derived for cluster synchronization. The conditions show that the couplings of multi-node clusters from one-node clusters have beneficial effects on cluster synchronization. Based on the effects of the one-node clusters, an effective and universal control scheme is put forward for the first time. The obtained results may help us better understand the relation between cluster synchronization and cluster structures of the networks. The validity of the control scheme is confirmed through two numerical simulations, in a network with no cluster structure and in a scale-free network.

  3. Clustering Fossils in Solid Inflation

    E-Print Network [OSTI]

    Mohammad Akhshik

    2014-09-10T23:59:59.000Z

    In solid inflation the single field non-Gaussianity consistency condition is violated. As a result, the long tensor perturbation induces observable clustering fossils in the form of quardupole anisotropy in large scale structure power spectrum. In this work we revisit the bispectrum analysis for the scalar-scalar-scalar and tensor-scalar-scalar for the general parameter space of solid. We consider the parameter space of the model in which the level of non-Gaussianity generated is consistent with Planck constraints. Specializing to this allowed range of model parameter, we calculate the quadrupole anisotropy induced from the long tensor perturbations on the power spectrum of scalar perturbations. We argue that imprints of clustering fossil from primordial gravitational waves on large scale structures can be detected from the future galaxy surveys.

  4. The Architecture of Ant-Based Clustering to improve Topographic Mapping

    E-Print Network [OSTI]

    behind ant-based clustering is that autonomous stochastic agents, called ants, move data objects on a low stochastic agents, called ants, that move input samples x X from m(x) to new location m (x). #12;Ants might. Probabilities for picking and dropping are computed using the average similarity x(i) between x X and input sam

  5. Cosmological constraints from the virial mass function of nearby galaxy groups and clusters

    E-Print Network [OSTI]

    Hill, James Colin

    2008-01-01T23:59:59.000Z

    In this thesis, I present a new determination of the cluster mass function in a volume ~107 h-03 70 Mpc3 using the ROSAT-2MASS-FAST Group Survey (R2FGS). R2FGS is an X-ray-selected sample of systems from the ROSAT All-Sky ...

  6. Host-IP Clustering Technique for Deep Web Characterization Denis Shestakov

    E-Print Network [OSTI]

    Hammerton, James

    Host-IP Clustering Technique for Deep Web Characterization Denis Shestakov Department of Media databases. This part of the Web, known as the deep Web, is to date relatively unexplored and even major are aimed at more accurate estimation of main parameters of the deep Web by sampling one national web domain

  7. A fast and recursive algorithm for clustering large datasets with k-medians

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    tech- niques such as k-means, trimmed k-means and PAM (partitioning around medoids). Finally, this new of the k-means algorithms. They are very fast and only require O(kn) operations, where n is the sample size by the barycenters of the elements belonging to each cluster. A major drawback of the k-means algorithms

  8. JAC, Hilo, 26/08/2010 Old Star Clusters in the Milky

    E-Print Network [OSTI]

    Froebrich, Dirk

    ) Decontamination/Classification 3) Results/Conclusions #12;JAC, Hilo, 26/08/2010 Whybother? Most (~90%) stars) determine radius via: The FSR Cluster Sample #12;JAC, Hilo, 26/08/2010 Fore/Background decontamination adaptation of the (Bonatto & Bica 2007) decontamination procedure #12;JAC, Hilo, 26/08/2010 Fore

  9. Acceptance sampling using judgmental and randomly selected samples

    SciTech Connect (OSTI)

    Sego, Landon H.; Shulman, Stanley A.; Anderson, Kevin K.; Wilson, John E.; Pulsipher, Brent A.; Sieber, W. Karl

    2010-09-01T23:59:59.000Z

    We present a Bayesian model for acceptance sampling where the population consists of two groups, each with different levels of risk of containing unacceptable items. Expert opinion, or judgment, may be required to distinguish between the high and low-risk groups. Hence, high-risk items are likely to be identifed (and sampled) using expert judgment, while the remaining low-risk items are sampled randomly. We focus on the situation where all observed samples must be acceptable. Consequently, the objective of the statistical inference is to quantify the probability that a large percentage of the unsampled items in the population are also acceptable. We demonstrate that traditional (frequentist) acceptance sampling and simpler Bayesian formulations of the problem are essentially special cases of the proposed model. We explore the properties of the model in detail, and discuss the conditions necessary to ensure that required samples sizes are non-decreasing function of the population size. The method is applicable to a variety of acceptance sampling problems, and, in particular, to environmental sampling where the objective is to demonstrate the safety of reoccupying a remediated facility that has been contaminated with a lethal agent.

  10. Sample Residential Program Term Sheet

    Broader source: Energy.gov [DOE]

    A sample for defining and elaborating on the specifics of a clean energy loan program. Author: U.S. Department of Energy

  11. IWTU Process Sample Analysis Report

    SciTech Connect (OSTI)

    Nick Soelberg

    2013-04-01T23:59:59.000Z

    CH2M-WG Idaho (CWI) requested that Battelle Energy Alliance (BEA) analyze various samples collected during June – August 2012 at the Integrated Waste Treatment Facility (IWTU). Samples of IWTU process materials were collected from various locations in the process. None of these samples were radioactive. These samples were collected and analyzed to provide more understanding of the compositions of various materials in the process during the time of the process shutdown that occurred on June 16, 2012, while the IWTU was in the process of nonradioactive startup.

  12. Pair extended coupled cluster doubles

    E-Print Network [OSTI]

    Henderson, Thomas M; Scuseria, Gustavo E

    2015-01-01T23:59:59.000Z

    The accurate and efficient description of strongly correlated systems remains an important challenge for computational methods. Doubly occupied configuration interaction (DOCI), in which all electrons are paired and no correlations which break these pairs are permitted, can in many cases provide an accurate account of strong correlations, albeit at combinatorial computational cost. Recently, there has been significant interest in a method we refer to as pair coupled cluster doubles (pCCD), a variant of coupled cluster doubles in which the electrons are paired. This is simply because pCCD provides energies nearly identical to those of DOCI, but at mean-field computational cost (disregarding the cost of the two-electron integral transformation). Here, we introduce the more complete pair extended coupled cluster doubles (pECCD) approach which, like pCCD, has mean-field cost and reproduces DOCI energetically. We show that unlike pCCD, pECCD also reproduces the DOCI wave function with high accuracy. Moreoever, pEC...

  13. Binary Frequencies in Globular Clusters

    E-Print Network [OSTI]

    Ji, Jun

    2015-01-01T23:59:59.000Z

    Binary stars are predicted to have an important role in the evolution of globular clusters, so we obtained binary fractions for 35 globular clusters that were imaged in the F606W and F814W with the ACS on the Hubble Space Telescope. When compared to the values of prior efforts (Sollima et al. 2007; Milone et al. 2012), we find significant discrepancies, despite each group correcting for contamination effects and having performed the appropriate reliability tests. The most reliable binary fractions are obtained when restricting the binary fraction to q > 0.5. Our analysis indicates that the range of the binary fractions is nearly an order of magnitude for the lowest dynamical ages, suggesting that there is a broad distribution in the binary fraction at globular cluster formation. Dynamical effects also appears to decrease the core binary fractions by a factor of two over a Hubble time, but this is a weak relationship. We confirm a correlation from previous work that the binary fraction within the core radius d...

  14. THE LUMINOSITY PROFILES OF BRIGHTEST CLUSTER GALAXIES

    SciTech Connect (OSTI)

    Donzelli, C. J.; Muriel, H. [Instituto de Investigaciones en Astronomia Teorica y Experimental IATE, Observatorio Astronomico OAC, Laprida 854, X5000BGR, Cordoba (Argentina); Madrid, J. P., E-mail: charly@oac.uncor.edu [Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, VIC 3122 (Australia)

    2011-08-01T23:59:59.000Z

    We have derived detailed R-band luminosity profiles and structural parameters for a total of 430 brightest cluster galaxies (BCGs), down to a limiting surface brightness of 24.5 mag arcsec{sup -2}. Light profiles were initially fitted with a Sersic's R {sup 1/n} model, but we found that 205 ({approx}48%) BCGs require a double component model to accurately match their light profiles. The best fit for these 205 galaxies is an inner Sersic model, with indices n {approx} 1-7, plus an outer exponential component. Thus, we establish the existence of two categories of the BCG luminosity profiles: single and double component profiles. We found that double profile BCGs are brighter ({approx}0.2 mag) than single profile BCGs. In fact, the Kolmogorov-Smirnov test applied to these subsamples indicates that they have different total magnitude distributions, with mean values M{sub R} = -23.8 {+-} 0.6 mag for single profile BCGs and M{sub R} = -24.0 {+-} 0.5 mag for double profile BCGs. We find that partial luminosities for both subsamples are indistinguishable up to r = 15 kpc, while for r > 20 kpc the luminosities we obtain are on average 0.2 mag brighter for double profile BCGs. This result indicates that extra-light for double profile BCGs does not come from the inner region but from the outer regions of these galaxies. The best-fit slope of the Kormendy relation for the whole sample is a = 3.13 {+-} 0.04. However, when fitted separately, single and double profile BCGs show different slopes: a{sub single} = 3.29 {+-} 0.06 and a{sub double} = 2.79 {+-} 0.08. Also, the logarithmic slope of the metric luminosity {alpha} is higher in double profile BCGs ({alpha}{sub double} = 0.65 {+-} 0.12) than in single profile BCGs ({alpha}{sub single} = 0.59 {+-} 0.14). The mean isophote outer ellipticity (calculated at {mu} {approx} 24 mag arcsec{sup -2}) is higher in double profile BCGs (e{sub double} = 0.30 {+-} 0.10) than in single profile BCGs (e{sub single} = 0.26 {+-} 0.11). Similarly, the mean absolute value of inner minus outer ellipticity is also higher in double profile BCGs. From a subsample of 24 BCGs, we found strong evidence that extra-light at intermediate radii in double profile BCGs is related to the presence of a faint stellar envelope. Similarly, from another subsample of 12 BCGs we also found that extra-light is related to star formation. On the other hand, we did not find differences between these two BCG categories when we compared global cluster properties such as the BCG-projected position relative to the cluster X-ray center emission, X-ray luminosity, or BCG orientation with respect to the cluster position angle.

  15. Defining And Characterizing Sample Representativeness For DWPF Melter Feed Samples

    SciTech Connect (OSTI)

    Shine, E. P.; Poirier, M. R.

    2013-10-29T23:59:59.000Z

    Representative sampling is important throughout the Defense Waste Processing Facility (DWPF) process, and the demonstrated success of the DWPF process to achieve glass product quality over the past two decades is a direct result of the quality of information obtained from the process. The objective of this report was to present sampling methods that the Savannah River Site (SRS) used to qualify waste being dispositioned at the DWPF. The goal was to emphasize the methodology, not a list of outcomes from those studies. This methodology includes proven methods for taking representative samples, the use of controlled analytical methods, and data interpretation and reporting that considers the uncertainty of all error sources. Numerous sampling studies were conducted during the development of the DWPF process and still continue to be performed in order to evaluate options for process improvement. Study designs were based on use of statistical tools applicable to the determination of uncertainties associated with the data needs. Successful designs are apt to be repeated, so this report chose only to include prototypic case studies that typify the characteristics of frequently used designs. Case studies have been presented for studying in-tank homogeneity, evaluating the suitability of sampler systems, determining factors that affect mixing and sampling, comparing the final waste glass product chemical composition and durability to that of the glass pour stream sample and other samples from process vessels, and assessing the uniformity of the chemical composition in the waste glass product. Many of these studies efficiently addressed more than one of these areas of concern associated with demonstrating sample representativeness and provide examples of statistical tools in use for DWPF. The time when many of these designs were implemented was in an age when the sampling ideas of Pierre Gy were not as widespread as they are today. Nonetheless, the engineers and statisticians used carefully thought out designs that systematically and economically provided plans for data collection from the DWPF process. Key shared features of the sampling designs used at DWPF and the Gy sampling methodology were the specification of a standard for sample representativeness, an investigation that produced data from the process to study the sampling function, and a decision framework used to assess whether the specification was met based on the data. Without going into detail with regard to the seven errors identified by Pierre Gy, as excellent summaries are readily available such as Pitard [1989] and Smith [2001], SRS engineers understood, for example, that samplers can be biased (Gy?s extraction error), and developed plans to mitigate those biases. Experiments that compared installed samplers with more representative samples obtained directly from the tank may not have resulted in systematically partitioning sampling errors into the now well-known error categories of Gy, but did provide overall information on the suitability of sampling systems. Most of the designs in this report are related to the DWPF vessels, not the large SRS Tank Farm tanks. Samples from the DWPF Slurry Mix Evaporator (SME), which contains the feed to the DWPF melter, are characterized using standardized analytical methods with known uncertainty. The analytical error is combined with the established error from sampling and processing in DWPF to determine the melter feed composition. This composition is used with the known uncertainty of the models in the Product Composition Control System (PCCS) to ensure that the wasteform that is produced is comfortably within the acceptable processing and product performance region. Having the advantage of many years of processing that meets the waste glass product acceptance criteria, the DWPF process has provided a considerable amount of data about itself in addition to the data from many special studies. Demonstrating representative sampling directly from the large Tank Farm tanks is a difficult, if not unsolvable enterprise due to li

  16. Constraining globular cluster formation through studies of young massive clusters - V. ALMA observations of clusters in the Antennae

    E-Print Network [OSTI]

    Cabrera-Ziri, I; Longmore, S N; Brogan, C; Hollyhead, K; Larsen, S S; Whitmore, B; Johnson, K; Chandar, R; Henshaw, J D; Davies, B; Hibbard, J E

    2015-01-01T23:59:59.000Z

    Some formation scenarios that have been put forward to explain multiple populations within Globular Clusters (GCs) require that the young massive cluster have large reservoirs of cold gas within them, which is necessary to form future generations of stars. In this paper we use deep observations taken with Atacama Large Millimeter/sub-millimeter Array (ALMA) to assess the amount of molecular gas within 3 young (50-200 Myr) massive (~10^6 Msun) clusters in the Antennae galaxies. No significant CO(3--2) emission was found associated with any of the three clusters. We place upper limits for the molecular gas within these clusters of ~1x10^5 Msun (or cool gas within young massive clusters at these ages.

  17. Hazard Sampling Dialog General Layout

    E-Print Network [OSTI]

    Zhang, Tao

    1 Hazard Sampling Dialog General Layout The dialog's purpose is to display information about the hazardous material being sampled by the UGV so either the system or the UV specialist can identify the risk level of the hazard. The dialog is associated with the hazmat reading icons (Table 1). Components

  18. Database Sampling with Functional Dependencies

    E-Print Network [OSTI]

    Riera, Jesús Bisbal

    Database Sampling with Functional Dependencies Jes´us Bisbal, Jane Grimson Department of Computer there is a need to prototype the database which the applications will use when in operation. A prototype database can be built by sampling data from an existing database. Including relevant semantic information when

  19. BLOOD SAMPLING SYSTEM TROUBLESHOOTING TIPS

    E-Print Network [OSTI]

    Kay, Mark A.

    SAFESET TM BLOOD SAMPLING SYSTEM SAFESETTM TROUBLESHOOTING TIPS TO PREVENT BLOOD BACKING UP IN LINE that all air bubbles have been eliminated when priming o Invert and tap blood sampling ports to remove air volume o Reinfuse the patient's blood slowly, no faster than 1mL per second, by pressing the plunger back

  20. Sample push-out fixture

    DOE Patents [OSTI]

    Biernat, John L. (Scotia, NY)

    2002-11-05T23:59:59.000Z

    This invention generally relates to the remote removal of pelletized samples from cylindrical containment capsules. V-blocks are used to receive the samples and provide guidance to push out rods. Stainless steel liners fit into the v-channels on the v-blocks which permits them to be remotely removed and replaced or cleaned to prevent cross contamination between capsules and samples. A capsule holder securely holds the capsule while allowing manual up/down and in/out movement to align each sample hole with the v-blocks. Both end sections contain identical v-blocks; one that guides the drive out screw and rods or manual push out rods and the other to receive the samples as they are driven out of the capsule.

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

    E-Print Network [OSTI]

    Fornal, B; Smith, J A; Allam, S S; Rider, C J; Sung, H; Fornal, Bartosz; Tucker, Douglas L.; Allam, Sahar S.; Rider, Cristin J.; Sung, Hwankyung

    2006-01-01T23:59:59.000Z

    We continue our 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 we present data only on NGC 188, which is one of the oldest open clusters known in the Milky Way. We fit the Padova theoretical isochrones to our data. Assuming a solar metallicity for NGC 188, we 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.

  2. The Mass Profile of the Coma Galaxy Cluster

    E-Print Network [OSTI]

    M. J. Geller; Antonaldo Diaferio; M. J. Kurtz

    1999-03-19T23:59:59.000Z

    We use a new redshift survey complete to m_R=15.4 within 4.25 deg from the center of the Coma cluster to measure the mass profile of the cluster to r=5.5 Mpc/h. We extend the profile to r=10 Mpc/h with a further sample complete to m_R=15.4 in 42% of the area within a 10 deg radius and to m_{Zw}=15.5 in the remaining area. Galaxies within this region are falling onto the cluster on moderately radial orbits and thus do not satisfy virial equilibrium. Nonetheless, identification of the caustics in redshift space provides an estimate of the gravitational potential at radius r and hence of the system mass, M(<10 Mpc/h)=(1.65+-0.41)10^{15} M_\\odot/h (1-sigma error). Previous mass estimates derived from optical and X-ray observations are limited to r<2.5 Mpc/h. Our mass profile is consistent with these estimates but extends to distances four times as large. Over the entire range, the mass increases with r at the rate expected for a Navarro, Frenk & White (1997) density profile.

  3. The BMW Deep X-ray Cluster Survey

    E-Print Network [OSTI]

    Guzzo, L; Campana, S; Covino, S; Dell'Antonio, I P; Lazzati, D; Longhetti, M; Molinari, E; Panzera, M R; Tagliaferri, G

    2001-01-01T23:59:59.000Z

    We briefly describe the main features of the Brera Multi-Wavelet (BMW) survey of serendipitous X-ray clusters, based on the still unexploited ROSAT-HRI archival observations. Cluster candidates are selected from the general BMW catalogue of 20,000 sources based exclusively on their X-ray extension. Contrary to common wisdom, a clever selection of the HRI energy channels allows us to significantly reduce the background noise, thus greatly improving the ability to detect low surface-brightness sources as clusters. The resulting sample of ~250 candidates shows a very good sky coverage down to a flux \\~3x10^-14 erg/s/cm^2 ([0.5-2.0] keV band), i.e comparable to existing PSPC-based deep survey, with a particularly interesting area of ~100 sq.deg. around fluxes ~10^-13 erg/s/cm^2, i.e. where highly-luminous, rare systems at z~0.6-1 can be detected. At the same time, the superior angular resolution of the instrument should avoid biases against intrinsically small systems, while easing the identification process (e.g...

  4. The WARPS Survey: VI. Galaxy Cluster and Source Identifications from Phase I

    E-Print Network [OSTI]

    E. S. Perlman; D. J. Horner; L. R. Jones; C. A. Scharf; H. Ebeling; G. Wegner; M. Malkan

    2002-09-25T23:59:59.000Z

    We present in catalog form the optical identifications for objects from the first phase of the Wide Angle ROSAT Pointed Survey (WARPS). WARPS is a serendipitous survey of relatively deep, pointed ROSAT observations for clusters of galaxies. The X-ray source detection algorithm used by WARPS is Voronoi Tessellation and Percolation (VTP), a technique which is equally sensitive to point sources and extended sources of low surface brightness. WARPS-I is based on the central regions of 86 ROSAT PSPC fields, covering an area of 16.2 square degrees. We describe here the X-ray source screening and optical identification process for WARPS-I, which yielded 34 clusters at 0.06clusters form a complete, statistically well defined sample drawn from 75 of these 86 fields, covering an area of 14.1 square degrees, with a flux limit of $F (0.5-2.0 keV) = 6.5 \\times 10^{-14} erg cm^{-2} s^{-1}}$. This sample can be used to study the properties and evolution of the gas, galaxy and dark matter content of clusters, and to constrain cosmological parameters. We compare in detail the identification process and findings of WARPS to those from other recently published X-ray surveys for clusters, including RDCS, SHARC-Bright, SHARC-south and the CfA 160 deg$^2$ survey.

  5. The Seven Sisters DANCe. I. Empirical isochrones, Luminosity and Mass Functions of the Pleiades cluster

    E-Print Network [OSTI]

    Bouy, H; Sarro, L M; Barrado, D; Moraux, E; Bouvier, J; Cuillandre, J -C; Berihuete, A; Olivares, J; Beletsky, Y

    2015-01-01T23:59:59.000Z

    The DANCe survey provides photometric and astrometric (position and proper motion) measurements for approximately 2 millions unique sources in a region encompassing $\\approx$80deg$^{2}$ centered around the Pleiades cluster. We aim at deriving a complete census of the Pleiades, and measure the mass and luminosity function of the cluster. Using the probabilistic selection method described in Sarro+2014, we identify high probability members in the DANCe ($i\\ge$14mag) and Tycho-2 ($V\\lesssim$12mag) catalogues, and study the properties of the cluster over the corresponding luminosity range. We find a total of 2109 high probability members, of which 812 are new, making it the most extensive and complete census of the cluster to date. The luminosity and mass functions of the cluster are computed from the most massive members down to $\\approx$0.025M$_{\\odot}$. The size, sensitivity and quality of the sample result in the most precise luminosity and mass functions observed to date for a cluster. Our census supersedes ...

  6. The Early-type Dwarf-to-Giant Ratio and Substructure in the Coma Cluster

    E-Print Network [OSTI]

    Jeff Secker; William E. Harris

    1996-05-15T23:59:59.000Z

    We have obtained new CCD photometry for a sample of $\\simeq 800$ early-type galaxies (dwarf and giant ellipticals) in the central 700 arcmin$^2$ of the Coma cluster, complete in color and in magnitude to $R = 22.5$ mag ($M_R \\simeq -12$ mag for $H_0 = 86$ km/sec/Mpc). The composite luminosity function for all galaxies in the cluster core (excluding NGC 4874 and NGC 4889) is modeled as the sum of a Gaussian distribution for the giant galaxies and a Schechter function for the dwarf elliptical galaxies. We determine that the early-type dwarf-to-giant ratio (EDGR) for Coma is identical to that measured for the less rich Virgo cluster; i.e., the EDGR does not increase as predicted by the EDGR-richness correlation. We postulate that the presence of substructure is an important factor in determining the cluster's EDGR; that is, the EDGR for Coma is consistent with the Coma cluster being built up from the merger of multiple less-rich galaxy clusters.

  7. Probing the Large Magellanic Cloud's recent chemical enrichment history through its star clusters

    E-Print Network [OSTI]

    Palma, Tali; Geisler, Doug; Gramajo, Luciana V; Ahumada, Andrea V

    2015-01-01T23:59:59.000Z

    We present Washington system colour-magnitude diagrams (CMDs) for 17 practically unstudied star clusters located in the bar as well as in the inner disc and outer regions of the Large Magellanic Cloud (LMC). Cluster sizes were estimated from star counts distributed throughout the entire observed fields. Based on the best fits of theoretical isochrones to the cleaned $(C-T_1,T_1)$ CMDs, as well as on the $\\delta T_1$ parameter and the standard giant branch method, we derive ages and metallicities for the cluster sample. Four objects are found to be intermediate-age clusters (1.8-2.5 Gyr), with [Fe/H] ranging from -0.66 to -0.84. With the exception of SL263, a very young cluster ($\\sim$ 16 Myr), the remaining 12 objects are aged between 0.32 and 0.89 Gyr, with their [Fe/H] values ranging from -0.19 to -0.50. We combined our results with those for other 231 clusters studied in a similar way using the Washington system. The resulting age-metallicity relationship shows a significant dispersion in metallicities, wh...

  8. Landscape Characterization and Representativeness Analysis for Understanding Sampling Network Coverage

    SciTech Connect (OSTI)

    Maddalena, Damian; Hoffman, Forrest; Kumar, Jitendra; Hargrove, William

    2014-08-01T23:59:59.000Z

    Sampling networks rarely conform to spatial and temporal ideals, often comprised of network sampling points which are unevenly distributed and located in less than ideal locations due to access constraints, budget limitations, or political conflict. Quantifying the global, regional, and temporal representativeness of these networks by quantifying the coverage of network infrastructure highlights the capabilities and limitations of the data collected, facilitates upscaling and downscaling for modeling purposes, and improves the planning efforts for future infrastructure investment under current conditions and future modeled scenarios. The work presented here utilizes multivariate spatiotemporal clustering analysis and representativeness analysis for quantitative landscape characterization and assessment of the Fluxnet, RAINFOR, and ForestGEO networks. Results include ecoregions that highlight patterns of bioclimatic, topographic, and edaphic variables and quantitative representativeness maps of individual and combined networks.

  9. Landscape Characterization and Representativeness Analysis for Understanding Sampling Network Coverage

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Maddalena, Damian; Hoffman, Forrest; Kumar, Jitendra; Hargrove, William

    Sampling networks rarely conform to spatial and temporal ideals, often comprised of network sampling points which are unevenly distributed and located in less than ideal locations due to access constraints, budget limitations, or political conflict. Quantifying the global, regional, and temporal representativeness of these networks by quantifying the coverage of network infrastructure highlights the capabilities and limitations of the data collected, facilitates upscaling and downscaling for modeling purposes, and improves the planning efforts for future infrastructure investment under current conditions and future modeled scenarios. The work presented here utilizes multivariate spatiotemporal clustering analysis and representativeness analysis for quantitative landscape characterization and assessment of the Fluxnet, RAINFOR, and ForestGEO networks. Results include ecoregions that highlight patterns of bioclimatic, topographic, and edaphic variables and quantitative representativeness maps of individual and combined networks.

  10. Oct 30th & 31st Clustering review

    E-Print Network [OSTI]

    Mitchell, Tom

    CLUSTERING Oct 30th & 31st Daegun Won #12;Outline ·Clustering review · K-means · GMM · Hierarchical clustering ·Examples #12;K-means & GMM #12;K-means · #12;K-means (2) ·Linear decision boundary · Voronoi #12;LET'S SEE SOME EXAMPLES! #12;K-means ­ seed choice? #12;Oops! #12;K-means ·What's the effect

  11. The Swift X-ray Telescope Cluster Survey III: Cluster Catalog from 2005-2012 Archival Data

    E-Print Network [OSTI]

    Liu, Teng; Tundo, Elena; Moretti, Alberto; Rosati, Piero; Wang, Jun-Xian; Tagliaferri, Gianpiero; Campana, Sergio; Giavalisco, Mauro

    2015-01-01T23:59:59.000Z

    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 to 2012, 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 degree to avoid high HI 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 degree^2. We identify extended source candidates in the soft-band (0.5-2keV) 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 minim...

  12. E-Print Network 3.0 - alpha decay cluster Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    relationship for the alpha decay... life-time was derived on the ground of the fission theory of alpha ... Source: Ecole Polytechnique, Centre de mathmatiques Collection:...

  13. Globular Cluster Formation in M82

    E-Print Network [OSTI]

    S. J. Lipscy; P. Plavchan

    2003-11-12T23:59:59.000Z

    We present high resolution mid-infrared (mid-IR; 11.7 and 17.65 micron) maps of the central 400 pc region of the starburst galaxy M82. Seven star forming clusters are identified which together provide ~ 15% of the total mid-IR luminosity of the galaxy. Combining the mid-IR data with thermal radio measurements and near- and mid-IR line emission, we find that these young stellar clusters have inferred masses and sizes comparable to globular clusters. At least 20% of the star formation in M82 is found to occur in super-star clusters.

  14. Black holes in young stellar clusters

    SciTech Connect (OSTI)

    Goswami, Sanghamitra; Kiel, Paul; Rasio, Frederic A. [Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208 (United States)

    2014-02-01T23:59:59.000Z

    We present theoretical models for stellar black hole (BH) properties in young, massive star clusters. Using a Monte Carlo code for stellar dynamics, we model realistic star clusters with N ? 5 × 10{sup 5} stars and significant binary fractions (up to 50%) with self-consistent treatments of stellar dynamics and stellar evolution. We compute the formation rates and characteristic properties of single and binary BHs for various representative ages, cluster parameters, and metallicities. Because of dynamical interactions and supernova (SN) kicks, more single BHs end up retained in clusters compared to BHs in binaries. We also find that the ejection of BHs from a cluster is a strong function of initial density. In low-density clusters (where dynamical effects are negligible), it is mainly SN kicks that eject BHs from the cluster, whereas in high-density clusters (initial central density ? {sub c}(0) ? 10{sup 5} M {sub ?} pc{sup –3} in our models) the BH ejection rate is enhanced significantly by dynamics. Dynamical interactions of binary systems in dense clusters also modify the orbital period and eccentricity distributions while increasing the probability of a BH having a more massive companion.

  15. Wide field imaging of distant clusters

    E-Print Network [OSTI]

    T. Treu

    2004-08-05T23:59:59.000Z

    Wide field imaging is key to understanding the build-up of distant clusters and their galaxy population. By focusing on the so far unexplored outskirts of clusters, where infalling galaxies first hit the cluster potential and the hot intracluster medium, we can help separate cosmological field galaxy evolution from that driven by environment. I present a selection of recent advancements in this area, with particular emphasis on Hubble Space Telescope wide field imaging, for its superior capability to deliver galaxy morphologies and precise shear maps of distant clusters.

  16. Multiphoton ionization of large water clusters

    SciTech Connect (OSTI)

    Apicella, B., E-mail: apicella@irc.cnr.it [Combustion Research Institute, IRC–C.N.R., P.le Tecchio 80, 80125 Napoli (Italy); Li, X. [Key Laboratory of Power Machinery and Engineering, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240 (China); Passaro, M. [CNISM and Chemical Engineering, Materials and Industrial Production Department, University of Naples “Federico II,” P.le Tecchio 80, 80125 Napoli (Italy); Spinelli, N. [CNISM and Physics Department, University of Naples “Federico II,” Via Cintia, 80124 Napoli (Italy); Wang, X. [SPIN–C.N.R., Via Cintia, 80124 Napoli (Italy)

    2014-05-28T23:59:59.000Z

    Water clusters are multimers of water molecules held together by hydrogen bonds. In the present work, multiphoton ionization in the UV range coupled with time of flight mass spectrometry has been applied to water clusters with up to 160 molecules in order to obtain information on the electronic states of clusters of different sizes up to dimensions that can approximate the bulk phase. The dependence of ion intensities of water clusters and their metastable fragments produced by laser ionization at 355 nm on laser power density indicates a (3+1)-photon resonance-enhanced multiphoton ionization process. It also explains the large increase of ionization efficiency at 355 nm compared to that at 266 nm. Indeed, it was found, by applying both nanosecond and picosecond laser ionization with the two different UV wavelengths, that no water cluster sequences after n = 9 could be observed at 266 nm, whereas water clusters up to m/z 2000 Th in reflectron mode and m/z 3000 Th in linear mode were detected at 355 nm. The agreement between our findings on clusters of water, especially true in the range with n > 10, and reported data for liquid water supports the hypothesis that clusters above a critical dimension can approximate the liquid phase. It should thus be possible to study clusters just above 10 water molecules, for getting information on the bulk phase structure.

  17. The Impact of Rotation on Cluster Dynamics

    E-Print Network [OSTI]

    Christian Boily

    2000-02-23T23:59:59.000Z

    The evolution of rotating, isolated clusters of stars up to core-collapse is investigated with n-body numerical codes. The simulations start off from axisymmetric generalisations of King profiles, with added global angular momentum. In this contribution I report on results obtained for two sets of single-mass cluster simulations. These confirm the more rapid evolution of even mildly-rotating clusters. A model is presented with rotational energy comparable to omega-Centauri's; it reaches core-collapse in less than half the time required for non-rotating model clusters.

  18. Optimization of synchronization in gradient clustered networks

    E-Print Network [OSTI]

    Xingang Wang; Liang Huang; Ying-Cheng Lai; Choy Heng Lai

    2007-11-23T23:59:59.000Z

    We consider complex clustered networks with a gradient structure, where sizes of the clusters are distributed unevenly. Such networks describe more closely actual networks in biophysical systems and in technological applications than previous models. Theoretical analysis predicts that the network synchronizability can be optimized by the strength of the gradient field but only when the gradient field points from large to small clusters. A remarkable finding is that, if the gradient field is sufficiently strong, synchronizability of the network is mainly determined by the properties of the subnetworks in the two largest clusters. These results are verified by numerical eigenvalue analysis and by direct simulation of synchronization dynamics on coupled-oscillator networks.

  19. A faint galaxy redshift survey behind massive clusters

    SciTech Connect (OSTI)

    Frye, Brenda

    1999-12-01T23:59:59.000Z

    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 {approximately}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.

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

    SciTech Connect (OSTI)

    Contreras, R. [INAF-Osservatorio Astronomico di Bologna, via Ranzani 1, 40127, Bologna (Italy); Catelan, M. [Departamento de AstronomIa y Astrofisica, Pontificia Universidad Catolica de Chile, Av. Vicuna Mackenna 4860, 782-0436 Macul, Santiago (Chile); Smith, H. A.; Kuehn, C. A. [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Pritzl, B. J. [Department of Physics and Astronomy, University of Wisconsin, Oshkosh, WI 54901 (United States); Borissova, J. [Departamento de Fisica y AstronomIa, Facultad de Ciencias, Universidad de ValparaIso, Ave. Gran Bretana 1111, Playa Ancha, Casilla 5030, ValparaIso (Chile)

    2010-12-15T23:59:59.000Z

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

  1. Cold Gas in Cluster Cores

    E-Print Network [OSTI]

    Megan Donahue

    2006-11-26T23:59:59.000Z

    I review the literature's census of the cold gas in clusters of galaxies. Cold gas here is defined as the gas that is cooler than X-ray emitting temperatures (~10^7 K) and is not in stars. I present new Spitzer IRAC and MIPS observations of Abell 2597 (PI: Sparks) that reveal significant amounts of warm dust and star formation at the level of 5 solar masses per year. This rate is inconsistent with the mass cooling rate of 20 +/- 5 solar masses per year inferred from a FUSE [OVI] detection.

  2. Evolution of the Blue Luminosity-to-Baryon Mass Ratio of Clusters of Galaxies

    E-Print Network [OSTI]

    Kazuhiro Shimasaku

    2000-01-31T23:59:59.000Z

    We derive the ratio of total blue luminosity to total baryon mass, LB/Mb, for massive (Mgas at the Abell radius is \\ge 1 \\times 10^{13} h^{-2.5} \\Msolar) clusters of galaxies up to z \\simeq 1 from the literature. Twenty-two clusters in our sample are at z > 0.1. Assuming that the relative mix of hot gas and galaxies in clusters does not change during cluster evolution, we use LB/Mb to probe the star formation history of the galaxy population as a whole in clusters. We find that LB/Mb of clusters increases with redshift from LB/Mb=0.024 (solar units) at z = 0 to \\simeq 0.06 at z=1, indicating a factor of 2-3 brightening (we assume H0=70 km/s/Mpc). This amount of brightening is almost identical to the brightening of the M/LB ratio of early-type galaxies in clusters at 0.02 \\le z \\le 0.83 reported by van Dokkum et al. (1998). We compare the observed brightening of LB/Mb with luminosity evolution models for the galaxy population as a whole, changing the e-folding time of star formation \\tau by 0.1 \\le \\tau \\le 5 Gyr and the formation redshift \\zF by 2 \\le \\zF < \\infty. We find that \\tau=0.1 Gyr 'single burst' models with \\zF \\ge 3 and \\tau=5 Gyr 'disk' models with arbitrary \\zF are consistent with the observed brightening, while models with \\tau=1-2 Gyr tend to predict too steep brightening. We also derive the ratio of blue luminosity density to baryon density for field galaxies, adopting \\Omega_b h^2 = 0.02, and find that blue luminosity per unit baryon is similar in clusters and in fields up to z \\simeq 1 within the observational uncertainties.

  3. Detecting Climate Change in Multivariate Time Series Data by Novel Clustering and Cluster Tracing Techniques

    E-Print Network [OSTI]

    Detecting Climate Change in Multivariate Time Series Data by Novel Clustering and Cluster Tracing Aachen University, Germany {kremer, guennemann, seidl}@cs.rwth-aachen.de Abstract--Climate change can series, and trace the clusters over time. A climate pattern is categorized as a changing pattern

  4. Agglomerative Fuzzy K-Means Clustering Algorithm with Selection of Number of Clusters

    E-Print Network [OSTI]

    Cheung, Yiu-ming

    Agglomerative Fuzzy K-Means Clustering Algorithm with Selection of Number of Clusters Mark Junjie--In this paper, we present an agglomerative fuzzy K-Means clustering algorithm for numerical data, an extension to the standard fuzzy K-Means algorithm by introducing a penalty term to the objective function to make

  5. Optimal interval clustering: Application to Bregman clustering and statistical mixture learning

    E-Print Network [OSTI]

    Nielsen, Frank

    clustering of n scalar elements into k pairwise disjoint intervals. This case includes 1D Euclidean k-means- hood. Index Terms--Clustering, dynamic programming, k-means, Bregman divergences, statistical mixtures is the celebrated k-means [1] that seeks to minimize the sum of intra-cluster variances by prescribing beforehand

  6. Cluster environments around quasars at 0.5 < z < 0.8

    E-Print Network [OSTI]

    M. Wold; M. Lacy; P. B. Lilje; S. Serjeant

    1999-10-14T23:59:59.000Z

    We have observed the galaxy environments around two complete samples of radio-loud (steep-spectrum) and radio-quiet quasars (RLQ and RQQ) at 0.5 < z < 0.8 that are matched in B-luminosity, and find that the environments of both quasar populations are pratically indistinguishable. A few objects are found in relatively rich clusters, but on average, they seem to prefer galaxy groups or cluster of approximatly Abell class 0. By combining the RLQ sample with samples from the literature, we detect a weak, but significant, positive correlation between environmental richness and quasar radio luminosity. This may give us clues about what determines a quasar's radio luminosity.

  7. Sample Business Plan Framework 3

    Broader source: Energy.gov [DOE]

    U.S. Department of Energy Better Buildings Neighborhood Program: Sample Business Plan Framework 1: A program seeking to continue operations in the post-grant period as a not-for-profit (NGO) entity.

  8. Sample Business Plan Framework 2

    Broader source: Energy.gov [DOE]

    U.S. Department of Energy Better Buildings Neighborhood Program: Sample Business Plan Framework 1: A program seeking to continue operations in the post-grant period as a not-for-profit (NGO) entity.

  9. Sample Business Plan Framework 4

    Broader source: Energy.gov [DOE]

    U.S. Department of Energy Better Buildings Neighborhood Program: Sample Business Plan Framework 1: A program seeking to continue operations in the post-grant period as a not-for-profit (NGO) entity.

  10. Sample Business Plan Framework 1

    Broader source: Energy.gov [DOE]

    U.S. Department of Energy Better Buildings Neighborhood Program: Sample Business Plan Framework 1: A program seeking to continue operations in the post-grant period as a not-for-profit (NGO) entity.

  11. THE RICH GLOBULAR CLUSTER SYSTEM OF ABELL 1689 AND THE RADIAL DEPENDENCE OF THE GLOBULAR CLUSTER FORMATION EFFICIENCY

    SciTech Connect (OSTI)

    Alamo-Martínez, K. A.; González-Lópezlira, R. A. [Centro de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, Morelia 58090 (Mexico); Blakeslee, J. P.; Côté, P.; Ferrarese, L. [Herzberg Institute of Astrophysics, National Research Council of Canada, Victoria, BC V9E 2E7 (Canada); Jee, M. J. [Department of Physics, University of California, Davis, One Shields Avenue, Davis, CA 95616 (United States); Jordán, A. [Departamento de Astronomía y Astrofísica, Pontificia Universidad Católica de Chile, 7820436 Macul, Santiago (Chile); Meurer, G. R. [International Centre for Radio Astronomy Research, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 (Australia); Peng, E. W. [Department of Astronomy and Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China); West, M. J., E-mail: k.alamo@crya.unam.mx [European Southern Observatory, Alonso de Córdova 3107, Vitacura, Santiago (Chile)

    2013-09-20T23:59:59.000Z

    We study the rich globular cluster (GC) system in the center of the massive cluster of galaxies Abell 1689 (z = 0.18), one of the most powerful gravitational lenses known. With 28 Hubble Space Telescope/Advanced Camera for Surveys orbits in the F814W bandpass, we reach a magnitude I{sub 814} = 29 with ?>90% completeness and sample the brightest ?5% of the GC system. Assuming the well-known Gaussian form of the GC luminosity function (GCLF), we estimate a total population of N{sup total}{sub GC}= 162,850{sup +75,450}{sub -51,310} GCs within a projected radius of 400 kpc. As many as half of the GCs may comprise an intracluster component. Even with the sizable uncertainties, which mainly result from the uncertain GCLF parameters, this system is by far the largest GC population studied to date. The specific frequency S{sub N} is high, but not uncommon for central galaxies in massive clusters, rising from S{sub N} ? 5 near the center to ?12 at large radii. Passive galaxy fading would increase S{sub N} by ?20% at z = 0. We construct the radial mass profiles of the GCs, stars, intracluster gas, and lensing-derived total mass, and we compare the mass fractions as a function of radius. The estimated mass in GCs, M{sub GC}{sup total} = 3.9 × 10{sup 10} M{sub ?}, is comparable to ?80% of the total stellar mass of the Milky Way. The shape of the GC mass profile appears intermediate between those of the stellar light and total cluster mass. Despite the extreme nature of this system, the ratios of the GC mass to the baryonic and total masses, and thus the GC formation efficiency, are typical of those in other rich clusters when comparing at the same physical radii. The GC formation efficiency is not constant, but varies with radius, in a manner that appears similar for different clusters; we speculate on the reasons for this similarity in profile.

  12. An Increase in the faint red galaxy population in massive clusters since z~0.5

    E-Print Network [OSTI]

    J. P. Stott; Ian Smail; A. C. Edge; H. Ebeling; G. P. Smith; J. -P. Kneib; K. A. Pimbblet

    2007-03-19T23:59:59.000Z

    We compare the luminosity functions for red galaxies lying on the restframe (U-V) color-magnitude sequence in a homogeneous sample of ten X-ray luminous clusters from the MACS survey at z~0.5 to a similarly selected X-ray cluster sample at z~0.1. We exploit deep Hubble Space Telescope ACS imaging in the F555W and F814W passbands of the central 1.2Mpc diameter regions of the distant clusters to measure precise colors for the galaxies in these regions and statistically correct for contamination by field galaxies using observations of blank fields. We apply an identical analysis to ground-based photometry of the z~0.1 sample. This comparison demonstrates that the number of faint, Mv~ -19, red galaxies relative to the bright population seen in the central regions of massive clusters has roughly doubled over the 4 Gyrs between z~0.5 and z~0.1. We quantify this difference by measuring the dwarf to giant ratio on the red sequence which increases by a factor of at least 2.2+/- 0.4 since z~0.5. This is consistent with the idea that many faint, blue star-forming galaxies in high density environments are transforming onto the red sequence in the last half of the Hubble time.

  13. A New Radio - X-Ray Probe of Galaxy Cluster Magnetic Fields

    E-Print Network [OSTI]

    T. E. Clarke; P. P. Kronberg; H. Boehringer

    2000-11-14T23:59:59.000Z

    Results are presented of a new VLA-ROSAT study that probes the magnetic field strength and distribution over a sample of 16 ``normal'' low redshift (z = 5-10 (l/10 kpc)^{-1/2} microGauss, where l is the field correlation length. These results lead to a global estimate of the total magnetic energy in clusters, and give new insight into the ultimate energy origin, which is likely gravitational. These results also shed some light on the cluster evolutionary conditions that existed at the onset of cooling flows.

  14. NO HEAVY-ELEMENT DISPERSION IN THE GLOBULAR CLUSTER M92

    SciTech Connect (OSTI)

    Cohen, Judith G., E-mail: jlc@astro.caltech.edu [Palomar Observatory, Mail Stop 249-17, California Institute of Technology, Pasadena, CA 91125 (United States)

    2011-10-20T23:59:59.000Z

    Although there have been recent claims that there is a large dispersion in the abundances of the heavy neutron capture elements in the old Galactic globular cluster M92, we show that the measured dispersion for the absolute abundances of four of the rare earth elements within a sample of 12 luminous red giants in M92 ({<=}0.07 dex) does not exceed the relevant sources of uncertainty. As expected from previous studies, the heavy elements show the signature of the r-process. Their abundance ratios are essentially identical to those of M30, another nearby globular cluster of similar metallicity.

  15. SPECTROPHOTOMETRIC INDICES AND METAL CONTENT OF GALACTIC GLOBULAR CLUSTERS

    E-Print Network [OSTI]

    S. Covino; S. Galletti; L. E. Pasinetti

    1995-03-06T23:59:59.000Z

    Spectrophotometric indices for $18$ Galactic globular clusters, obtained from CCD observations and careful reductions, were used to determine reliable calibrations on metallicity $[Fe/H]$. The indices were measured in the bandpasses adopted by Burnstein et al. (\\cite{BFGK84}). Adding other observations of Burnstein et al. (\\cite{BFGK84}) we obtained our results from an homogeneous sample of indices for $26$ globular clusters. Relations with indices defined by other Authors and with metallicity photometric indices or parameters were also computed. In each case the relations are quite satisfactory. Observational data were compared with synthetic indices derived from Buzzoni's (\\cite{B89}) models and detailed discussions were performed for $Mg_2$, $Fe_{52}$, and $H_\\beta$. The observational points seem to be systematically shifted with respect to the fiducial lines traced by the models. The scenario confirms that a certain degree of oxygen enhancement would be necessary to obtain a better agreement between observed data and theoretical predictions. This enhancement, however, removes some of the disagreement, but not all of it. The dependence of the observed $Fe_{52}$ and $H_\\beta$ indices on the metal content for different HB morphologies was considered. Finally, some results were also discussed from a statistical point of view. A principal component analysis was applied to the index sample to study the number of independent parameters necessary to reproduce the observations. The whole index set is completely consistent with a one-parameter family.

  16. Demixing cascades in cluster crystals

    E-Print Network [OSTI]

    Nigel B. Wilding; Peter Sollich

    2014-07-14T23:59:59.000Z

    In a cluster crystal, each lattice site is occupied by multiple soft-core particles. As the number density is increased at zero temperature, a `cascade' of isostructural phase transitions can occur between states whose site occupancy differs by unity. For low but finite temperature, each of these transitions terminates in a critical point. Using tailored Monte Carlo simulation techniques we have studied such demixing cascades in systems of soft particles interacting via potentials of the generalized exponential form $u(r)=\\epsilon\\exp[-(r/\\sigma)^n]$. We have estimated the critical parameters of the first few transitions in the cascade as a function of the softness parameter $n$. The critical temperature and pressure exhibit non-monotonic behaviour as $n$ is varied, although the critical chemical potential remains monotonic. The trends for the pressure and chemical potential are confirmed by cell model calculations at zero temperature. As $n\\to 2^+$, all the transitions that we have observed are preempted by melting although we cannot rule out that clustering transitions survive at high density.

  17. Adsorption, Desorption, and Clustering H20 on Pt (111). | EMSL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Desorption, and Clustering H20 on Pt (111). Adsorption, Desorption, and Clustering H20 on Pt (111). Abstract: The adsorption, desorption, and clustering behavior of H20 on Pt(111)...

  18. Au34-: A Fluxional Core-Shell Cluster. | EMSL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Au34-: A Fluxional Core-Shell Cluster. Au34-: A Fluxional Core-Shell Cluster. Abstract: Among the large Aun – clusters for n > 20, the photoelectron spectra of Au34...

  19. Consensus Clustering Algorithms: Comparison and Refinement Andrey Goder

    E-Print Network [OSTI]

    Filkov, Vladimir

    -deterministic clustering algorithms, e.g. K-means, are sensitive to the choice of the initial seed clusters; running K-meansConsensus Clustering Algorithms: Comparison and Refinement Andrey Goder Vladimir Filkov Computer

  20. When Network Coding improves the Performances of Clustered Wireless Networks

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    When Network Coding improves the Performances of Clustered Wireless Networks that significantly increases the performances of clustering algorithms in wireless multi-hop networks-XOR coding; wireless multi-hop networks; clustering I. INTRODUCTION Partitioning nodes

  1. Knowledge-based cluster development in India : opportunities and challenges

    E-Print Network [OSTI]

    Singla, Chandan Dev

    2008-01-01T23:59:59.000Z

    Knowledge-based industries tend to cluster. The nature of activities illustrate the importance of networks and virtual and proximity aspects of clustering. Review of existing literature brings out the advantages of clustering ...

  2. Dynamics of excess electrons in atomic and molecular clusters

    E-Print Network [OSTI]

    Young, Ryan Michael

    2011-01-01T23:59:59.000Z

    Time-Resolved Dynamics in Acetonitrile Cluster Anions (CH 3Time-resolved dynamics in acetonitrile clusters anions (CH 3resolved dynamics in acetonitrile clusters anions (CH 3 CN)

  3. THE APM CLUSTER SURVEY: CLUSTER DETECTION AND LARGE-SCALE STRUCTURE

    E-Print Network [OSTI]

    G. B. Dalton

    1995-05-17T23:59:59.000Z

    The APM Cluster Survey was based on a modification of Abell's original classification scheme for galaxy clusters. Here we discuss the results of an investigation of the stability of the statistical properties of the cluster catalogue to changes in the selection parameters. For a poor choice of selection parameters we find clear indications of line-of-sight clusters, but there is a wide range of input parameters for which the statistical properties of the catalogue are stable. We conclude that clusters selected in this way are indeed useful as tracers of large-scale structure.

  4. Sampling Report for August 15, 2014 WIPP Samples

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn'tOrigin ofEnergy atLLC - FE DKT. 10-160-LNG - ORDERSTATE0-1ofEnergy SampleSample of

  5. Reference Potential source Data type Sampling site Type of samples Number of samples Method of source

    E-Print Network [OSTI]

    Meskhidze, Nicholas

    samples for Saharan dust from Libya back trajectory analysis Kandler et al. 2009 PSA NAF-2 Illite NAF-4 Illite/kaolinite ratio Chlorite/kaolinite ratio Carbonate content Libya (here: central

  6. Energy Accounting and Control on HPC clusters

    E-Print Network [OSTI]

    Lefèvre, Laurent

    Energy Accounting and Control on HPC clusters Yiannis Georgiou R&D Software Engineer #12;Objectives Issues that we wanted to deal with: Measure power and energy consumption on HPC clusters Attribute power and energy data to HPC components Calculate the energy consumption of jobs in the system Extract power

  7. Clustering Web Search Results Using Fuzzy Ants

    E-Print Network [OSTI]

    Gent, Universiteit

    Clustering Web Search Results Using Fuzzy Ants Steven Schockaert,* Martine De Cock, Chris Cornelis and Uncertainty Modelling Research Unit, Krijgslaan 281 (S9), B-9000 Gent, Belgium Algorithms for clustering Web existing approaches and illustrates how our algorithm can be applied to the problem of Web search results

  8. Cluster Parallel Loops Part I. Preliminaries

    E-Print Network [OSTI]

    Kaminsky, Alan

    ;14­2 BIG CPU, BIG DATA he massively parallel Bitcoin mining program in Chapter 13 still doesn't take full advantage of the cluster's parallel processing capabilities. Each Bitcoin mining task uses all the cores on just one node. So on the 10-node tardis cluster, I have to mine 10 or more Bitcoins to fully utilize

  9. An Experimental Comparison of Kernel Clustering Methods

    E-Print Network [OSTI]

    Masulli, Francesco

    , Support Vec- tor Clustering, and three standard methods: K-means, FCM-I, and FCM-II. The motiva- tion. #12;2. Methods 2.1. K-means This is the standard K-means clustering algorithm [13], included to be equal, while for m close to one we obtain crisp memberships as in K-means. By a Lagrangian approach

  10. STELLAR ENCOUNTER RATE IN GALACTIC GLOBULAR CLUSTERS

    SciTech Connect (OSTI)

    Bahramian, Arash; Heinke, Craig O.; Sivakoff, Gregory R.; Gladstone, Jeanette C., E-mail: bahramia@ualberta.ca [Department of Physics, University of Alberta, CCIS 4-183, Edmonton, AB, T5K 1V4 (Canada)

    2013-04-01T23:59:59.000Z

    The high stellar densities in the cores of globular clusters cause significant stellar interactions. These stellar interactions can produce close binary mass-transferring systems involving compact objects and their progeny, such as X-ray binaries and radio millisecond pulsars. Comparing the numbers of these systems and interaction rates in different clusters drives our understanding of how cluster parameters affect the production of close binaries. In this paper we estimate stellar encounter rates ({Gamma}) for 124 Galactic globular clusters based on observational data as opposed to the methods previously employed, which assumed 'King-model' profiles for all clusters. By deprojecting cluster surface brightness profiles to estimate luminosity density profiles, we treat 'King-model' and 'core-collapsed' clusters in the same way. In addition, we use Monte Carlo simulations to investigate the effects of uncertainties in various observational parameters (distance, reddening, surface brightness) on {Gamma}, producing the first catalog of globular cluster stellar encounter rates with estimated errors. Comparing our results with published observations of likely products of stellar interactions (numbers of X-ray binaries, numbers of radio millisecond pulsars, and {gamma}-ray luminosity) we find both clear correlations and some differences with published results.

  11. PHOTOIONIZED TOF MASS SPECTROMETRY OF ATOMIC CLUSTERS

    E-Print Network [OSTI]

    Maruyama, Shigeo

    for sev eral cluster sou rce nozzle condition s. Heliu m gas pressu re at the tim e of v aporization of solid m aterial played the key role in cluster size range obtain ed. Th e effect of pressu re was thorou

  12. Projection-based curve clustering Benjamin AUDER

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    -hydraulic computer code CATHARE is used to study the re- liability of reactor vessels. The code inputs are physical parameters and the outputs are time evolution curves of a few other physical quantities. As the CATHARE code process involves a clustering step. In the present paper, CATHARE output curves are clustered using a k

  13. Regional Innovation Clusters September 25 , 2012

    E-Print Network [OSTI]

    Levinson, David M.

    prosperity ­ Find, birth, build and celebrate clusters ­ Improve the business environment ­ Connect the dots by Professor Michael E. Porter and Monitor Company Group, L.P. -- Confidential -- CAM Q BMW Spartanburg #12 Automotive Cluster #12;Timken Technology Center Carroll A. Campbell Graduate Engineering Center IBMOracle BMW

  14. M31 Globular Clusters in the HST Archive: I. Cluster Detection and Completeness

    E-Print Network [OSTI]

    P. Barmby; J. P. Huchra

    2001-07-20T23:59:59.000Z

    Globular clusters at the distance of M31 have apparent angular sizes of a few arcseconds. While many M31 GCs have been detected and studied from ground-based images, the high spatial resolution of HST allows much more robust detection and characterization of star cluster properties. We present the results of a search of 157 HST/WFPC2 images of M31: we found 82 previously-cataloged globular cluster candidates as well as 32 new globular cluster candidates and 20 open cluster candidates. We present images of the new candidates and photometry for all clusters. We assess existing cluster catalogs' completeness and use the results to estimate the total number of GCs in M31 as 460+/-70. The specific frequency is S_N = 1.2+/-0.2 and the mass specific frequency T = 2.4+/-0.4; these values are at the upper end of the range seen for spiral galaxies.

  15. IP Profiling via Service Cluster Membership Vectors

    SciTech Connect (OSTI)

    Bartoletti, A

    2009-02-23T23:59:59.000Z

    This study investigates the feasibility of establishing and maintaining a system of compact IP behavioral profiles as a robust means of computer anomaly definition and detection. These profiles are based upon the degree to which a system's (IP's) network traffic is distributed among stable characteristic clusters derived of the aggregate session traffic generated by each of the major network services. In short, an IP's profile represents its degree of membership in these derived service clusters. The goal is to quantify and rank behaviors that are outside of the statistical norm for the services in question, or present significant deviation from profile for individual client IPs. Herein, we establish stable clusters for accessible features of common session traffic, migrate these clusters over time, define IP behavior profiles with respect to these clusters, migrate individual IP profiles over time, and demonstrate the detection of IP behavioral changes in terms of deviation from profile.

  16. Clustering attributed graphs: models, measures and methods

    E-Print Network [OSTI]

    Bothorel, Cecile; Magnani, Matteo; Micenkova, Barbora

    2015-01-01T23:59:59.000Z

    Clustering a graph, i.e., assigning its nodes to groups, is an important operation whose best known application is the discovery of communities in social networks. Graph clustering and community detection have traditionally focused on graphs without attributes, with the notable exception of edge weights. However, these models only provide a partial representation of real social systems, that are thus often described using node attributes, representing features of the actors, and edge attributes, representing different kinds of relationships among them. We refer to these models as attributed graphs. Consequently, existing graph clustering methods have been recently extended to deal with node and edge attributes. This article is a literature survey on this topic, organizing and presenting recent research results in a uniform way, characterizing the main existing clustering methods and highlighting their conceptual differences. We also cover the important topic of clustering evaluation and identify current open ...

  17. Sample rotating turntable kit for infrared spectrometers

    DOE Patents [OSTI]

    Eckels, Joel Del (Livermore, CA); Klunder, Gregory L. (Oakland, CA)

    2008-03-04T23:59:59.000Z

    An infrared spectrometer sample rotating turntable kit has a rotatable sample cup containing the sample. The infrared spectrometer has an infrared spectrometer probe for analyzing the sample and the rotatable sample cup is adapted to receive the infrared spectrometer probe. A reflectance standard is located in the rotatable sample cup. A sleeve is positioned proximate the sample cup and adapted to receive the probe. A rotator rotates the rotatable sample cup. A battery is connected to the rotator.

  18. Computer System, Cluster, and Networking Summer Institute Program...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    System, Cluster, and Networking Summer Institute Program Description The Computer System, Cluster, and Networking Summer Institute (CSCNSI) is a focused technical enrichment...

  19. Gate-tunable exchange coupling between cobalt clusters on graphene...

    Office of Scientific and Technical Information (OSTI)

    Accepted Manuscript: Gate-tunable exchange coupling between cobalt clusters on graphene Citation Details Title: Gate-tunable exchange coupling between cobalt clusters on...

  20. Iridium Complexes and Clusters in Dealuminated Zeolite HY: Distributio...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Iridium Complexes and Clusters in Dealuminated Zeolite HY: Distribution between Crystalline and Impurity Amorphous Regions. Iridium Complexes and Clusters in Dealuminated Zeolite...

  1. Cryogenic CO2 Formation on Oxidized Gold Clusters Synthesized...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Cryogenic CO2 Formation on Oxidized Gold Clusters Synthesized via Reactive Layer Assisted Deposition. Cryogenic CO2 Formation on Oxidized Gold Clusters Synthesized via Reactive...

  2. Approximating K-means-type clustering via semidefinite programming

    E-Print Network [OSTI]

    Jiming Peng

    2005-04-22T23:59:59.000Z

    Apr 22, 2005 ... Approximating K-means-type clustering via semidefinite ... Abstract: One of the fundamental clustering problems is to assign $n$ points into $k$ ...

  3. ClusterSculptor: Software for Expert-Steered Classification of...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and intuitive framework to aid scientists in data classification. ClusterSculptor uses k-means as the overall clustering engine, but allows tuning its parameters interactively,...

  4. Analysis of a Cluster Strategy for Near Term Hydrogen Infrastructure...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    a Cluster Strategy for Near Term Hydrogen Infrastructure Rollout in Southern California Analysis of a Cluster Strategy for Near Term Hydrogen Infrastructure Rollout in Southern...

  5. acid gene cluster: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the application of a novel clustering algorithm, Super-Paramagnetic Clustering (SPC) to analysis of gene expression profiles that were generated recently during a study of...

  6. arom gene cluster: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the application of a novel clustering algorithm, Super-Paramagnetic Clustering (SPC) to analysis of gene expression profiles that were generated recently during a study of...

  7. almt1 gene cluster: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the application of a novel clustering algorithm, Super-Paramagnetic Clustering (SPC) to analysis of gene expression profiles that were generated recently during a study of...

  8. All-Boron Aromatic Clusters as Potential New Inorganic Ligands...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Boron Aromatic Clusters as Potential New Inorganic Ligands and Building Blocks in Chemistry. All-Boron Aromatic Clusters as Potential New Inorganic Ligands and Building Blocks in...

  9. High performance computing: Clusters, constellations, MPPs, and future directions

    E-Print Network [OSTI]

    Dongarra, Jack; Sterling, Thomas; Simon, Horst; Strohmaier, Erich

    2003-01-01T23:59:59.000Z

    and Jim Gray, “High Performance Computing: Crays, Clusters,The Marketplace of High-Performance Computing”, ParallelHigh Performance Computing Clusters, Constellations, MPPs,

  10. Optimization of the Coupled Cluster Implementation in NWChem...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the Coupled Cluster Implementation in NWChem on Petascale Parallel Architectures. Optimization of the Coupled Cluster Implementation in NWChem on Petascale Parallel Architectures....

  11. Inertial impaction air sampling device

    DOE Patents [OSTI]

    Dewhurst, K.H.

    1987-12-10T23:59:59.000Z

    An inertial impactor to be used in an air sampling device for collection of respirable size particles in ambient air which may include a graphite furnace as the impaction substrate in a small-size, portable, direct analysis structure that gives immediate results and is totally self-contained allowing for remote and/or personal sampling. The graphite furnace collects suspended particles transported through the housing by means of the air flow system, and these particles may be analyzed for elements, quantitatively and qualitatively, by atomic absorption spectrophotometry. 3 figs.

  12. Inertial impaction air sampling device

    DOE Patents [OSTI]

    Dewhurst, K.H.

    1990-05-22T23:59:59.000Z

    An inertial impactor is designed which is to be used in an air sampling device for collection of respirable size particles in ambient air. The device may include a graphite furnace as the impaction substrate in a small-size, portable, direct analysis structure that gives immediate results and is totally self-contained allowing for remote and/or personal sampling. The graphite furnace collects suspended particles transported through the housing by means of the air flow system, and these particles may be analyzed for elements, quantitatively and qualitatively, by atomic absorption spectrophotometry. 3 figs.

  13. Spent nuclear fuel sampling strategy

    SciTech Connect (OSTI)

    Bergmann, D.W.

    1995-02-08T23:59:59.000Z

    This report proposes a strategy for sampling the spent nuclear fuel (SNF) stored in the 105-K Basins (105-K East and 105-K West). This strategy will support decisions concerning the path forward SNF disposition efforts in the following areas: (1) SNF isolation activities such as repackaging/overpacking to a newly constructed staging facility; (2) conditioning processes for fuel stabilization; and (3) interim storage options. This strategy was developed without following the Data Quality Objective (DQO) methodology. It is, however, intended to augment the SNF project DQOS. The SNF sampling is derived by evaluating the current storage condition of the SNF and the factors that effected SNF corrosion/degradation.

  14. THREE-CLUSTER NUCLEAR MOLECULES

    E-Print Network [OSTI]

    D. N. Poenaru; B. Dobrescu; W. Greiner

    2000-01-01T23:59:59.000Z

    A three-center phenomenological model able to explain, at least from a qualitative point of view, the difference in the observed yield of a particle-accompanied fission and that of binary fission was developed. It is derived from the liquid drop model under the assumption that the aligned configuration, with the emitted particle between the light and heavy fragment is obtained by increasing continuously the separation distance, while the radii of the light fragment and of the light particle are kept constant. During the first stage of the deformation one has a two-center evolution until the neck radius becomes equal to the radius of the emitted particle. Then the three center starts developing by decreasing with the same amount the two tip distances. In such a way a second minimum, typical for a cluster molecule, appears in the deformation energy. Examples are presented for 240 Pu parent nucleus emitting ?-particles and 14 C in a ternary process. 1

  15. A Multi-Wavelength Study of Low Redshift Cluster of Galaxies II. Environmental Impact on Galaxy Growth

    E-Print Network [OSTI]

    Atlee, David W

    2012-01-01T23:59:59.000Z

    Galaxy clusters provide powerful laboratories for the study of galaxy evolution, particularly the origin of correlations of morphology and star formation rate (SFR) with density. We construct visible to MIR spectral energy distributions (SEDs) of cluster galaxies and use them to measure stellar masses and SFRs in eight low redshift clusters, which we examine as a function of environment. A partial correlation analysis indicates that SFR depends strongly on R/R200 (>99.9% confidence) and is independent of projected local density at fixed radius. SFR also shows no residual dependence on stellar mass. We therefore conclude that interactions with the intra-cluster medium drive the evolution of SFRs in cluster galaxies. A merged sample of galaxies from the five most complete clusters shows \\propto(R/R200)^(1.3+/-0.7) for galaxies with R/R200<0.4. A decline in the fraction of SFGs toward the cluster center contributes most of this effect, but it is accompanied by a reduction in SFRs among star-forming galaxies (...

  16. 2009 Clusters, Nanocrystals & Nanostructures GRC

    SciTech Connect (OSTI)

    Lai-Sheng Wang

    2009-07-19T23:59:59.000Z

    For over thirty years, this Gordon Conference has been the premiere meeting for the field of cluster science, which studies the phenomena that arise when matter becomes small. During its history, participants have witnessed the discovery and development of many novel materials, including C60, carbon nanotubes, semiconductor and metal nanocrystals, and nanowires. In addition to addressing fundamental scientific questions related to these materials, the meeting has always included a discussion of their potential applications. Consequently, this conference has played a critical role in the birth and growth of nanoscience and engineering. The goal of the 2009 Gordon Conference is to continue the forward-looking tradition of this meeting and discuss the most recent advances in the field of clusters, nanocrystals, and nanostructures. As in past meetings, this will include new topics that broaden the field. In particular, a special emphasis will be placed on nanomaterials related to the efficient use, generation, or conversion of energy. For example, we anticipate presentations related to batteries, catalysts, photovoltaics, and thermoelectrics. In addition, we expect to address the controversy surrounding carrier multiplication with a session in which recent results addressing this phenomenon will be discussed and debated. The atmosphere of the conference, which emphasizes the presentation of unpublished results and lengthy discussion periods, ensures that attendees will enjoy a valuable and stimulating experience. Because only a limited number of participants are allowed to attend this conference, and oversubscription is anticipated, we encourage all interested researchers from academia, industry, and government institutions to apply as early as possible. An invitation is not required. We also encourage all attendees to submit their latest results for presentation at the poster sessions. We anticipate that several posters will be selected for 'hot topic' oral presentations. Because of the important role that students and postdocs play in the future of this field, we also anticipate to select several posters from young investigators for oral presentations.

  17. Example far-infrared SEDs for 4 Herschel-detected BCGs: A1835, MACS1423, A2667, A2390. All belong to known cool-core clusters. The green line shows the best fit

    E-Print Network [OSTI]

    Rawle, Tim

    to known cool-core clusters. The green line shows the best fit template from the Rieke+09 library, from, E. Egami1, A. Edge2, M. Rex1, for the Herschel Lensing Survey and LoCuSS collaborations 1Steward the Herschel Lensing Survey (HLS) and Local Cluster Substructure Survey (LoCuSS). The sample includes known

  18. Methods and Materials Sample Collection

    E-Print Network [OSTI]

    by Greenwood (1958). A 1.5-inch (3.8 em) mesh liner was laced into the cod end to retain small specimens which reported that Alaska pollock \\yas the principal species taken by these Japanese fisheries. However from flatfish samples collected in 1949 were reported by Mosher (1954); the Soviet collections of 1957

  19. Sample Internship Posting Department Name

    E-Print Network [OSTI]

    Bordenstein, Seth

    Sample Internship Posting Department Name: Internship Title: Location: Description of Organization are examples from other internship postings Interns will: · Analyze potential investments · Shadow team members(s) in ________ is desirable For a list of majors see http://admissions.vanderbilt.edu/major Internship Period: The following

  20. Waste tank characterization sampling limits

    SciTech Connect (OSTI)

    Tusler, L.A.

    1994-09-02T23:59:59.000Z

    This document is a result of the Plant Implementation Team Investigation into delayed reporting of the exotherm in Tank 241-T-111 waste samples. The corrective actions identified are to have immediate notification of appropriate Tank Farm Operations Shift Management if analyses with potential safety impact exceed established levels. A procedure, WHC-IP-0842 Section 12.18, ``TWRS Approved Sampling and Data Analysis by Designated Laboratories`` (WHC 1994), has been established to require all tank waste sampling (including core, auger and supernate) and tank vapor samples be performed using this document. This document establishes levels for specified analysis that require notification of the appropriate shift manager. The following categories provide numerical values for analysis that may indicate that a tank is either outside the operating specification or should be evaluated for inclusion on a Watch List. The information given is intended to translate an operating limit such as heat load, expressed in Btu/hour, to an analysis related limit, in this case cesium-137 and strontium-90 concentrations. By using the values provided as safety flags, the analytical laboratory personnel can notify a shift manager that a tank is in potential violation of an operating limit or that a tank should be considered for inclusion on a Watch List. The shift manager can then take appropriate interim measures until a final determination is made by engineering personnel.

  1. Licensing Guide and Sample License

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    TEI:HNOL06Y TRANSFER WORKIN6 6ROUP Lic:eniing Guide and Sample Lic:enie ICan.u City Plan I OFermilab OAK RIDGE Nuioul.

  2. Environmental Analysis & Policy: Sample Pathway

    E-Print Network [OSTI]

    Goldberg, Bennett

    Environmental Analysis & Policy: Sample Pathway Semester I Semester II Freshman Year CGS Core CGS Sustainable Development OR Spring GE 425 U.S. Environmental Policy (Senior) GE 309 Intermediate Env Analysis (Fall) EAP Elective Summer Environmental Internship Senior Year GE 420 Env Policy Analysis 4 th Semester

  3. Quantum rejection sampling Maris Ozols

    E-Print Network [OSTI]

    Cerf, Nicolas

    generation prob- lem. We exhibit an algorithm, which we call quantum rejec- tion sampling, and analyze its technical innovation is an extension of the automorphism principle to continuous groups that arise or to redistribute to lists, requires prior specific permission and/or a fee. ITCS '12, January 08 - 10, 2012

  4. AUTOMATING GROUNDWATER SAMPLING AT HANFORD

    SciTech Connect (OSTI)

    CONNELL CW; HILDEBRAND RD; CONLEY SF; CUNNINGHAM DE

    2009-01-16T23:59:59.000Z

    Until this past October, Fluor Hanford managed Hanford's integrated groundwater program for the U.S. Department of Energy (DOE). With the new contract awards at the Site, however, the CH2M HILL Plateau Remediation Company (CHPRC) has assumed responsibility for the groundwater-monitoring programs at the 586-square-mile reservation in southeastern Washington State. These programs are regulated by the Resource Conservation and Recovery Act (RCRA) and the Comprehensive Environmental Response Compensation and Liability Act (CERCLA). The purpose of monitoring is to track existing groundwater contamination from past practices, as well as other potential contamination that might originate from RCRA treatment, storage, and disposal (TSD) facilities. An integral part of the groundwater-monitoring program involves taking samples of the groundwater and measuring the water levels in wells scattered across the site. More than 1,200 wells are sampled each year. Historically, field personnel or 'samplers' have been issued pre-printed forms that have information about the well(s) for a particular sampling evolution. This information is taken from the Hanford Well Information System (HWIS) and the Hanford Environmental Information System (HEIS)--official electronic databases. The samplers used these hardcopy forms to document the groundwater samples and well water-levels. After recording the entries in the field, the samplers turned the forms in at the end of the day and the collected information was posted onto a spreadsheet that was then printed and included in a log book. The log book was then used to make manual entries of the new information into the software application(s) for the HEIS and HWIS databases. This is a pilot project for automating this tedious process by providing an electronic tool for automating water-level measurements and groundwater field-sampling activities. The automation will eliminate the manual forms and associated data entry, improve the accuracy of the information recorded, and enhance the efficiency and sampling capacity of field personnel. The goal of the effort is to eliminate 100 percent of the manual input to the database(s) and replace the management of paperwork by the field and clerical personnel with an almost entirely electronic process. These activities will include the following: scheduling the activities of the field teams, electronically recording water-level measurements, electronically logging and filing Groundwater Sampling Reports (GSR), and transferring field forms into the site-wide Integrated Document Management System (IDMS).

  5. Effects of $?$-cluster breaking on 3$?$ cluster structures in $^{12}$C

    E-Print Network [OSTI]

    Tadahiro Suhara; Yoshiko Kanada-En'yo

    2015-02-17T23:59:59.000Z

    To clarify the effects of $\\alpha$-cluster breaking on 3$\\alpha$ cluster structures in $^{12}$C, we investigate $^{12}$C using a hybrid model that combines the Brink-Bloch cluster model with the $p_{3/2}$ subshell closure wave function. We have found that $\\alpha$-cluster breaking caused by spin-orbit force significantly changes cluster structures of excited $0^{+}$ states through orthogonality to lower states. Spatially developed cluster components of the $0^{+}_{2}$ state are reduced. The $0^{+}_{3}$ state changes from a vibration mode in the bending motion of three $\\alpha$ clusters to a chain-like 3$\\alpha$ structure having an open triangle configuration. As a result of these structure changes of $0^{+}$ states, the band assignment for the $2^{+}_{2}$ state is changed by the $\\alpha$-cluster breaking effect. Namely, in model calculations without the $\\alpha$-cluster breaking effect, the $0^{+}_{2}$ state is assigned to be the band-head of the $2^{+}_{2}$ state. However, when we incorporate $\\alpha$-cluster breaking caused by the spin-orbit force, the $0^{+}_{3}$ state is regarded as the band-head of the $2^{+}_{2}$ state.

  6. Jet Veto Clustering Logarithms Beyond Leading Order

    E-Print Network [OSTI]

    Simone Alioli; Jonathan R. Walsh

    2014-11-23T23:59:59.000Z

    Many experimental analyses separate events into exclusive jet bins, using a jet algorithm to cluster the final state and then veto on jets. Jet clustering induces logarithmic dependence on the jet radius R in the cross section for exclusive jet bins, a dependence that is poorly controlled due to the non-global nature of the clustering. At jet radii of experimental interest, the leading order (LO) clustering effects are numerically significant, but the higher order effects are currently unknown. We rectify this situation by calculating the most important part of the next-to-leading order (NLO) clustering logarithms of R for any 0-jet process, which enter as $O(\\alpha_s^3)$ corrections to the cross section. The calculation blends subtraction methods for NLO calculations with factorization properties of QCD and soft-collinear effective theory (SCET). We compare the size of the known LO and new NLO clustering logarithms and find that the impact of the NLO terms on the 0-jet cross section in Higgs production is small. This brings clustering effects under better control and may be used to improve uncertainty estimates on cross sections with a jet veto.

  7. The Formation History of Globular Clusters

    E-Print Network [OSTI]

    Dean E. McLaughlin

    2000-02-03T23:59:59.000Z

    The properties of old globular cluster systems in galaxy halos are used to infer quantitative constraints on aspects of generic star (cluster) formation. First, the spatial distribution of globulars in three large galaxies, together with trends in total cluster population vs. galaxy luminosity for 97 early-type systems plus the halo of the Milky Way, imply that bound stellar clusters formed with a universal efficiency throughout early protogalaxies: by mass, always 0.26% of star-forming gas was converted into globulars rather than halo field stars. That this fraction is so robust in the face of extreme variations in local and global galaxy environment suggests that any parcel of gas needs primarily to exceed a relative density threshold in order to form a bound cluster of stars. Second, it is shown that a strict, empirical scaling of total binding energy with luminosity and Galactocentric position is a defining equation for a fundamental plane of Galactic globular clusters. The characteristics of this plane, which subsumes all other observable correlations between the structural parameters of globulars, provide a small but complete set of facts that must be explained by theories of cluster formation and evolution in the Milky Way. It is suggested that the E_b(L,r_{\\rm gc}) relation specifically resulted from star formation efficiencies having been systematically higher inside more massive protoglobular gas clumps.

  8. A search for ultra-compact dwarf galaxies in the Centaurus galaxy cluster

    E-Print Network [OSTI]

    S. Mieske; M. Hilker; A. Jordan; L. Infante; M. Kissler-Patig

    2007-06-19T23:59:59.000Z

    Aim: To extend the investigations of ultra-compact dwarf galaxies (UCDs) beyond the well studied Fornax and Virgo clusters. Methods: We measured spectroscopic redshifts of about 400 compact object candidates with 19.2 < V < 22.4 mag in the central region of the Centaurus galaxy cluster (d=43Mpc), using VIMOS@VLT. The luminosity range of the candidates covers that of bright globular clusters (GCs) and of UCDs in Fornax and Virgo. Results: We confirm the cluster membership of 27 compact objects, covering an absolute magnitude range -12.2 < M_V < -10.9 mag. We do not find counterparts to the two very large and bright UCDs in Fornax and Virgo with M_V=-13.5 mag, possibly due to survey incompleteness. The compact objects' distribution in magnitude and space is consistent with that of the GC population. Their kinematics and spatial distribution associate them to the central galaxies rather than to the overall cluster potential. The compact objects have a mean metallicity consistent with that of the metal-rich globular cluster sub-population. Compact objects with high S/N spectra exhibit solar [alpha/Fe] abundances, consistent with typical dwarf elliptical galaxy values and unlike galactic bulge globular clusters. HST based size estimates for a sub-sample of eight compact objects reveal the existence of one very large object with half-light radius r_h around 30 pc, having M_V=-11.6 mag (~10^7 M_sun). This source shows super-solar [alpha/Fe] abundances. Seven further sources are only marginally larger than typical GCs with r_h in the range 4 to 10 pc. Conclusions: We consider the largest compact object found to be the only bona-fide UCD detected in our study. In order to improve our understanding of UCDs in Centaurus, a significant increase of our survey completeness is necessary.

  9. Evolution of globular cluster systems in elliptical galaxies. I. Log-normal initial mass function

    E-Print Network [OSTI]

    E. Vesperini

    2000-07-18T23:59:59.000Z

    We study the evolution of globular cluster systems (GCS) in elliptical galaxies and explore the dependence of their main properties on the mass and the size of the host galaxy.The dependence of the evolution of the GCS mass function (GCMF), of the fraction of surviving clusters and of the ratio of the final to initial mass in clusters on the structure of the host galaxy as well as their variation with the galactocentric distance inside individual host galaxies has been thoroughly investigated.After a survey over a large number of different host galaxies we have restricted our attention to a sample of galaxies with effective masses and radii equal to those observed for dwarf,normal and giant ellipticals. We show that, in spite of large differences in the fraction of surviving clusters, the final mean masses of the GCMF in massive galaxies are very similar to each other with a small galaxy-to-galaxy dispersion;low-mass compact galaxies tend to have smaller values of the final mean mass and a larger galaxy-to-galaxy dispersion. These findings are in agreement with those of recent observational analyses. The fraction of surviving clusters increases with the mass of the host galaxy. We show that a small difference between the initial and the final mean mass and dispersion of the GCMF and the lack of a significant radial dependence of the mean mass inside individual galaxies do not necessarily imply that evolutionary processes have been unimportant in the evolution of the initial population of clusters. For giant galaxies most disruption occurs within the effective radius while for low-mass galaxies a significant disruption of clusters takes place also at larger galactocentric distances. The dependence of the results obtained on the initial mean mass of the GCMF is investigated. (abridged)

  10. The 160 Square Degree ROSAT Survey: the Revised Catalog of 201 Clusters with Spectroscopic Redshifts

    E-Print Network [OSTI]

    Mullis, C R; Quintana, H; Vikhlinin, A; Henry, J P; Gioia, I M; Hornstrup, A; Forman, W; Jones, C

    2003-01-01T23:59:59.000Z

    We present the revised catalog of galaxy clusters detected as extended X-ray sources in the 160 Square Degree ROSAT Survey, including spectroscopic redshifts and X-ray luminosities for 200 of the 201 members. The median redshift is z~0.25 and the median X-ray luminosity is 4.2e+43 erg/s/h50^2 (0.5-2.0 keV). This is the largest high-redshift sample of X-ray selected clusters published to date. There are 73 objects at z>0.3 and 22 objects at z>0.5 drawn from a statistically complete flux-limited survey with a median object flux of 1.4d-13 erg/cm^2/s. We describe the optical follow-up of these clusters with an emphasis on our spectroscopy which has yielded 155 cluster redshifts, 110 of which are presented here for the first time. These measurements combined with 45 from the literature and other sources provide near-complete spectroscopic coverage for our survey. We discuss the final optical identifications for the extended X-ray sources in the survey region and compare our results to similar X-ray cluster search...

  11. The Gaia-ESO Survey: Detailed Abundances in the Metal-poor Globular Cluster NGC 4372

    E-Print Network [OSTI]

    Roman, I San; Geisler, D; Villanova, S; Kacharov, N; Koch, A; Carraro, G; Tautvaišiene, G; Vallenari, A; Alfaro, E J; Bensby, T; Flaccomio, E; Francois, P; Korn, A J; Pancino, E; Recio-Blanco, A; Smiljanic, R; Bergemann, M; Costado, M T; Damiani, F; Heiter, U; Hourihane, A; Jofré, P; Lardo, C; de Laverny, P; Masseron, T; Morbidelli, L; Sbordone, L; Sousa, S G; Worley, C C; Zaggia, S

    2015-01-01T23:59:59.000Z

    We present the abundance analysis for a sample of 7 red giant branch stars in the metal-poor globular cluster NGC 4372 based on UVES spectra acquired as part of the Gaia-ESO Survey. This is the first extensive study of this cluster from high resolution spectroscopy. We derive abundances of O, Na, Mg, Al, Si, Ca, Sc, Ti, Fe, Cr, Ni, Y, Ba, and La. We find a metallicity of [Fe/H] = -2.19 $\\pm$ 0.03 and find no evidence for a metallicity spread. This metallicity makes NGC 4372 one of the most metal-poor galactic globular clusters. We also find an {\\alpha}-enhancement typical of halo globular clusters at this metallicity. Significant spreads are observed in the abundances of light elements. In particular we find a Na-O anti-correlation. Abundances of O are relatively high compared with other globular clusters. This could indicate that NGC 4372 was formed in an environment with high O for its metallicity. A Mg-Al spread is also present which spans a range of more than 0.5 dex in Al abundances. Na is correlated wit...

  12. The Gaia-ESO Survey: Insights on the inner-disc evolution from open clusters

    E-Print Network [OSTI]

    Magrini, L; Donati, P; Bragaglia, A; Adibekyan, V; Romano, D; Smiljanic, R; Blanco-Cuaresma, S; Tautvaisiene, G; Friel, E; Overbeek, J; Jacobson, H; Cantat-Gaudin, T; Vallenari, A; Sordo, R; Pancino, E; Geisler, D; Roman, I San; Villanova, S; Casey, A; Hourihane, A; Worley, C C; Francois, P; Gilmore, G; Bensby, T; Flaccomio, E; Korn, A J; Recio-Blanco, A; Carraro, G; Costado, M T; Franciosini, E; Heiter, U; Jofree, P; Lardo, C; de Laverny, P; Monaco, L; Morbidelli, L; Sacco, G; Sousa, S G; Zaggia, S

    2015-01-01T23:59:59.000Z

    Context. The inner disc, linking the thin disc with the bulge, has been somehow neglected in the past because of intrinsic difficulties in its study, due, e.g., to crowding and high extinction. Open clusters located in the inner disc are among the best tracers of its chemistry at different ages and distances. Aims. We analyse the chemical patterns of four open clusters located within 7 kpc of the Galactic Centre and of field stars to infer the properties of the inner disc with the Gaia-ESO survey idr2/3 data release. Methods. We derive the parameters of the newly observed cluster, Berkeley 81, finding an age of about 1 Gyr and a Galactocentric distance of 5.4 kpc. We construct the chemical patterns of clusters and we compare them with those of field stars in the Solar neighbourhood and in the inner-disc samples. Results. Comparing the three populations we observe that inner-disc clusters and field stars are both, on average, enhanced in [O/Fe], [Mg/Fe] and [Si/Fe]. Using the idr2/3 results of M67, we estimate...

  13. Online Spectral Clustering on Network Streams

    E-Print Network [OSTI]

    Jia, Yi

    2012-12-31T23:59:59.000Z

    .3.1 First Order Approximation (FOA) Approach . . . . . . . . . . . . . 109 7.3.2 Eigen Perturbation Theory Based Approaches . . . . . . . . . . . . . 111 7.3.2.1 General Eigen Perturbation Theory (GEPT) Approach . . . 111 7.3.2.2 Enhanced Eigen Perturbation... of an evolving graph with two snapshots . . . . . . . . . . . . . 109 7.2 The clustering results of the evolving graph in Figure 7.1 by using SC-FOA . 110 xi 7.3 The clustering results of the evolving graph in Figure 7.1 by using FOA . . . 111 7.4 The clustering...

  14. Cluster state quantum computing in optical fibers

    E-Print Network [OSTI]

    Yasaman Soudagar; Felix Bussieres; Guido Berlin; Suzanne Lacroix; Jose M. Fernandez; Nicolas Godbout

    2006-05-12T23:59:59.000Z

    A scheme for the implementation of the cluster state model of quantum computing in optical fibers, which enables the feedforward feature, is proposed. This scheme uses the time-bin encoding of qubits. Following previously suggested methods of applying arbitrary one-qubit gates in optical fibers, two different ways for the realization of fusion gate types I and II for cluster production are proposed: a fully time-bin based encoding scheme and a combination of time-bin and polarization based encoding scheme. Also the methods of measurement in any desired bases for the purpose of the processing of cluster state computing for both these encodings are explained.

  15. Method for assaying clustered DNA damages

    DOE Patents [OSTI]

    Sutherland, Betsy M.

    2004-09-07T23:59:59.000Z

    Disclosed is a method for detecting and quantifying clustered damages in DNA. In this method, a first aliquot of the DNA to be tested for clustered damages with one or more lesion-specific cleaving reagents under conditions appropriate for cleavage of the DNA to produce single-strand nicks in the DNA at sites of damage lesions. The number average molecular length (Ln) of double stranded DNA is then quantitatively determined for the treated DNA. The number average molecular length (Ln) of double stranded DNA is also quantitatively determined for a second, untreated aliquot of the DNA. The frequency of clustered damages (.PHI..sub.c) in the DNA is then calculated.

  16. Smoothed Particle Inference: A Kilo-Parametric Method for X-ray Galaxy Cluster Modeling

    SciTech Connect (OSTI)

    Peterson, John R.; Marshall, P.J.; /KIPAC, Menlo Park; Andersson, K.; /Stockholm U. /SLAC

    2005-08-05T23:59:59.000Z

    We propose an ambitious new method that models the intracluster medium in clusters of galaxies as a set of X-ray emitting smoothed particles of plasma. Each smoothed particle is described by a handful of parameters including temperature, location, size, and elemental abundances. Hundreds to thousands of these particles are used to construct a model cluster of galaxies, with the appropriate complexity estimated from the data quality. This model is then compared iteratively with X-ray data in the form of adaptively binned photon lists via a two-sample likelihood statistic and iterated via Markov Chain Monte Carlo. The complex cluster model is propagated through the X-ray instrument response using direct sampling Monte Carlo methods. Using this approach the method can reproduce many of the features observed in the X-ray emission in a less assumption-dependent way that traditional analyses, and it allows for a more detailed characterization of the density, temperature, and metal abundance structure of clusters. Multi-instrument X-ray analyses and simultaneous X-ray, Sunyaev-Zeldovich (SZ), and lensing analyses are a straight-forward extension of this methodology. Significant challenges still exist in understanding the degeneracy in these models and the statistical noise induced by the complexity of the models.

  17. Variation of lattice constant and cluster formation in GaAsBi

    SciTech Connect (OSTI)

    Puustinen, J.; Schramm, A.; Guina, M. [Optoelectronics Research Centre, Tampere University of Technology, P.O. Box 692, FI-33101 Tampere (Finland)] [Optoelectronics Research Centre, Tampere University of Technology, P.O. Box 692, FI-33101 Tampere (Finland); Wu, M.; Luna, E. [Paul-Drude Institut für Festkörperelektronik, Hausvogteiplatz 5-7, 10117 Berlin (Germany)] [Paul-Drude Institut für Festkörperelektronik, Hausvogteiplatz 5-7, 10117 Berlin (Germany); Laukkanen, P. [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland)] [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Laitinen, M.; Sajavaara, T. [Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä (Finland)] [Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä (Finland)

    2013-12-28T23:59:59.000Z

    We investigate the structural properties of GaAsBi layers grown by molecular beam epitaxy on GaAs at substrate temperatures between 220–315 °C. Irrespective of the growth temperature, the structures exhibited similar Bi compositions, and good overall crystal quality as deduced from X-Ray diffraction measurements. After thermal annealing at temperatures as low as 500 °C, the GaAsBi layers grown at the lowest temperatures exhibited a significant reduction of the lattice constant. The lattice variation was significantly larger for Bi-containing samples than for Bi-free low-temperature GaAs samples grown as a reference. Rutherford backscattering spectrometry gave no evidence of Bi diffusing out of the layer during annealing. However, dark-field and Z-contrast transmission electron microscopy analyses revealed the formation of GaAsBi clusters with a Bi content higher than in the surrounding matrix, as well as the presence of metallic As clusters. The apparent reduction of the lattice constant can be explained by a two-fold process: the diffusion of the excess As incorporated within As{sub Ga} antisites to As clusters, and the reduction of the Bi content in the GaAs matrix due to diffusion of Bi to GaAsBi clusters. Diffusion of both As and Bi are believed to be assisted by the native point defects, which are present in the low-temperature as-grown material.

  18. The Clustering of Luminous Red Galaxies in the Sloan Digital Sky Survey Imaging Data

    E-Print Network [OSTI]

    Padmanabhan, N; Seljak, U; Makarov, A; Bahcall, Neta A; Blanton, M R; Brinkmann, J; Eisenstein, D J; Finkbeiner, D P; Gunn, J E; Hogg, D W; Ivezic, Z; Knapp, G R; Loveday, J; Lupton, R H; Nichol, R C; Schneider, D P; Strauss, M A; Tegmark, M; York, D G

    2006-01-01T23:59:59.000Z

    We present the 3D real space clustering power spectrum of a sample of \\~600,000 luminous red galaxies (LRGs) measured by the Sloan Digital Sky Survey (SDSS), using photometric redshifts. This sample of galaxies ranges from redshift z=0.2 to 0.6 over 3,528 deg^2 of the sky, probing a volume of 1.5 (Gpc/h)^3, making it the largest volume ever used for galaxy clustering measurements. We measure the angular clustering power spectrum in eight redshift slices and combine these into a high precision 3D real space power spectrum from k=0.005 (h/Mpc) to k=1 (h/Mpc). We detect power on gigaparsec scales, beyond the turnover in the matter power spectrum, on scales significantly larger than those accessible to current spectroscopic redshift surveys. We also find evidence for baryonic oscillations, both in the power spectrum, as well as in fits to the baryon density, at a 2.5 sigma confidence level. The statistical power of these data to constrain cosmology is ~1.7 times better than previous clustering analyses. Varying t...

  19. Mon. Not. R. Astron. Soc. 000, 000000 (0000) Printed 14 October 2009 (MN LATEX style file v2.2) Cosmological Constraints from the Clustering of the Sloan Digital

    E-Print Network [OSTI]

    Skibba, Ramin A.

    .2) Cosmological Constraints from the Clustering of the Sloan Digital Sky Survey DR7 Luminous Red Galaxies Beth A derived from a sample of Luminous Red Galaxies (LRGs) from the Sloan Digital Sky Survey Seventh Data Re

  20. Adaptive Noisy Clustering Michael CHICHIGNOUD

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    with respect to the Lebesgue measure. Since we observe a corrupted sample, a direct approach as the popular k-means is not suitable in this case. In this paper, we propose a noisy k-means minimization, which is based on the k-means an adaptive upper bound for a new selection rule, called ERC (Empirical Risk Comparison). This selection rule

  1. Environmental surveillance master sampling schedule

    SciTech Connect (OSTI)

    Bisping, L E

    1992-01-01T23:59:59.000Z

    Environmental surveillance of the Hanford Site and surrounding areas is conducted by the Pacific Northwest Laboratory (PNL) for the US Department of Energy (DOE). This document contains the planned schedule for routine sample collection for the Surface Environmental Surveillance Project (SESP) and Ground-Water Monitoring Project. Samples for radiological analyses include Air-Particulate Filter, gases and vapor; Water/Columbia River, Onsite Pond, Spring, Irrigation, and Drinking; Foodstuffs/Animal Products including Whole Milk, Poultry and Eggs, and Beef; Foodstuffs/Produce including Leafy Vegetables, Vegetables, and Fruit; Foodstuffs/Farm Products including Wine, Wheat and Alfalfa; Wildlife; Soil; Vegetation; and Sediment. Direct Radiation Measurements include Terrestrial Locations, Columbia River Shoreline Locations, and Onsite Roadway, Railway and Aerial, Radiation Surveys.

  2. Adaptive Sampling in Hierarchical Simulation

    SciTech Connect (OSTI)

    Knap, J; Barton, N R; Hornung, R D; Arsenlis, A; Becker, R; Jefferson, D R

    2007-07-09T23:59:59.000Z

    We propose an adaptive sampling methodology for hierarchical multi-scale simulation. The method utilizes a moving kriging interpolation to significantly reduce the number of evaluations of finer-scale response functions to provide essential constitutive information to a coarser-scale simulation model. The underlying interpolation scheme is unstructured and adaptive to handle the transient nature of a simulation. To handle the dynamic construction and searching of a potentially large set of finer-scale response data, we employ a dynamic metric tree database. We study the performance of our adaptive sampling methodology for a two-level multi-scale model involving a coarse-scale finite element simulation and a finer-scale crystal plasticity based constitutive law.

  3. Offline solid phase microextraction sampling system

    DOE Patents [OSTI]

    Harvey, Chris A. (French Camp, CA)

    2008-12-16T23:59:59.000Z

    An offline solid phase microextraction (SPME) sampling apparatus for enabling SPME samples to be taken a number of times from a previously collected fluid sample (e.g. sample atmosphere) stored in a fused silica lined bottle which keeps volatile organics in the fluid sample stable for weeks at a time. The offline SPME sampling apparatus has a hollow body surrounding a sampling chamber, with multiple ports through which a portion of a previously collected fluid sample may be (a) released into the sampling chamber, (b) SPME sampled to collect analytes for subsequent GC analysis, and (c) flushed/purged using a fluidically connected vacuum source and purging fluid source to prepare the sampling chamber for additional SPME samplings of the same original fluid sample, such as may have been collected in situ from a headspace.

  4. Food Cluster: A Strategy for Job Growth in North

    E-Print Network [OSTI]

    Minnesota, University of

    with Aeroponics Business Requires low-skill labor Faster production cycle Reduced material & energy costs 16 #12, commercial urban ag. business to anchor the food cluster 3. Find smaller urban farming businesses to serve Cluster Businesses Recommendations 2 #12;Business Clusters Drive Economic Growth · Business Cluster

  5. Secure Two-Party k-Means Clustering Rafail Ostrovsky

    E-Print Network [OSTI]

    Ostrovsky, Rafail

    Secure Two-Party k-Means Clustering Paul Bunn Rafail Ostrovsky Abstract The k-Means Clustering. To date there have been numerous attempts to create specific multiparty k-means clustering protocols a Two-Party k-Means Clustering Protocol that guarantees privacy, and is more efficient than utilizing

  6. Performance impact of dynamic parallelism on different clustering algorithms

    E-Print Network [OSTI]

    Taufer, Michela

    will be measured using two well-known clustering algorithms that exhibit data dependencies: the K-means clustering and the hierarchical clustering. K-means has a sequential data dependence wherein iterations occur in a linear fashion drawbacks of CUDA 5's new dynamic parallelism feature. Keywords: K-means, Divisive hierarchical clustering

  7. Spectral Embedded Clustering Feiping Nie1,2

    E-Print Network [OSTI]

    Xu, Dong

    methods, such as spectral clustering, Clustering with local and global regularization, K-means and Discrimi- native K-means. The experiments on many real- world data sets show that SEC significantly out- performs the existing spectral clustering methods as well as K-means clustering related methods. 1

  8. The globular cluster system of M31

    E-Print Network [OSTI]

    P. Jablonka

    2001-07-17T23:59:59.000Z

    This review presents the current status of our knowledge of M31 star clusters. Given the broadness of the subject, I chose to focus on some of its aspects which are not covered by the other participants in this conference.

  9. Classification and clustering problems in microarray analysis

    E-Print Network [OSTI]

    Tseng, George C. "Chien-Cheng"

    -based · Distance-based 3. Estimating # of clusters 4. Methods & comparison · Hierarchical, K-means, SOM, Tight & comparison · Linear & quadratic discriminant, CART, SVM 3. Gene (feature) selection · Ranking, Recursive

  10. UCD Candidates in the Hydra Cluster

    E-Print Network [OSTI]

    Elizabeth Wehner; William Harris

    2007-08-10T23:59:59.000Z

    NGC 3311, the giant cD galaxy in the Hydra cluster (A1060), has one of the largest globular cluster systems known. We describe new Gemini GMOS (g',i') photometry of the NGC 3311 field which reveals that the red, metal-rich side of its globular cluster population extends smoothly upward into the mass range associated with the new class of Ultra-Compact Dwarfs (UCDs). We identify 29 UCD candidates with estimated masses > 6x10^6 solar masses and discuss their characteristics. This UCD-like sequence is the most well defined one yet seen, and reinforces current ideas that the high-mass end of the globular cluster sequence merges continuously into the UCD sequence, which connects in turn to the E galaxy structural sequence.

  11. Customer Data Clustering using Data Mining Technique

    E-Print Network [OSTI]

    Rajagopal, Dr Sankar

    2011-01-01T23:59:59.000Z

    Classification and patterns extraction from customer data is very important for business support and decision making. Timely identification of newly emerging trends is very important in business process. Large companies are having huge volume of data but starving for knowledge. To overcome the organization current issue, the new breed of technique is required that has intelligence and capability to solve the knowledge scarcity and the technique is called Data mining. The objectives of this paper are to identify the high-profit, high-value and low-risk customers by one of the data mining technique - customer clustering. In the first phase, cleansing the data and developed the patterns via demographic clustering algorithm using IBM I-Miner. In the second phase, profiling the data, develop the clusters and identify the high-value low-risk customers. This cluster typically represents the 10-20 percent of customers which yields 80% of the revenue.

  12. Carbon Fiber Cluster Strategy | ornl.gov

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Carbon Fiber Cluster Strategy ORNL has a 40-year history in R&D on fiber-reinforced composite materials, and has been leading DOE's low-cost carbon fiber initiative for more than...

  13. Flagship Cluster Hiring Initiative Computational Science

    E-Print Network [OSTI]

    Allen, Gabrielle

    Flagship Cluster Hiring Initiative Computational Science: Advancing Research, Society and the Economy Gabrielle Allen (PI) Thomas Sterling (Presenter/co-PI) Department of Computer Science Center for Computation & Technology #12;Computational Science: Advancing Research, Society and the Economy, External

  14. Adaptively refined large eddy simulations of clusters

    E-Print Network [OSTI]

    Maier, A; Schmidt, W; Niemeyer, J C

    2009-01-01T23:59:59.000Z

    We present a numerical scheme for modelling unresolved turbulence in cosmological adaptive mesh refinement codes. As a first application, we study the evolution of turbulence in the intra-cluster medium and in the core of a galaxy cluster. Simulations with and without subgrid scale model are compared in detail. Since the flow in the ICM is subsonic, the global turbulent energy contribution at the unresolved length scales is smaller than 1% of the internal energy. We find that the production of turbulence is closely correlated with merger events occurring in the cluster environment, and its dissipation locally affects the cluster energy budget. Because of this additional source of dissipation, the core temperature is larger and the density is smaller in the presence of subgrid scale turbulence than in the standard adiabatic run, resulting in a higher entropy core value.

  15. Gravitational clustering in Static and Expanding Backgrounds

    E-Print Network [OSTI]

    T. Padmanabhan

    2003-08-28T23:59:59.000Z

    A brief summary of several topics in the study of gravitational many body problem is given. The discussion covers both static backgrounds (applicable to astrophysical systems) as well as clustering in an expanding background (relevant for cosmology)

  16. NGC 7789: AN OPEN CLUSTER CASE STUDY

    E-Print Network [OSTI]

    Overbeek, Jamie C.

    We have obtained high-resolution spectra of 32 giants in the open cluster NGC 7789 using the Wisconsin–Indiana–Yale–NOAO Hydra spectrograph. We explore differences in atmospheric parameters and elemental abundances caused ...

  17. Nuclear clusters with Halo Effective Field Theory

    E-Print Network [OSTI]

    Renato Higa

    2008-09-30T23:59:59.000Z

    After a brief discussion of effective field theory applied to nuclear clusters, I present the aspect of Coulomb interactions, with applications to low-energy alpha-alpha and nucleon-alpha scattering.

  18. Shocks and cold fronts in galaxy clusters

    E-Print Network [OSTI]

    Maxim Markevitch; Alexey Vikhlinin

    2007-04-24T23:59:59.000Z

    Table of contents (abridged): COLD FRONTS Origin and evolution of merger cold fronts Cold fronts in cluster cool cores . . . Simulations of gas sloshing. Origin of density discontinuity. . . . Effect of sloshing on cluster mass estimates and cooling flows. Zoology of cold fronts COLD FRONTS AS EXPERIMENTAL TOOL Velocities of gas flows Thermal conduction and diffusion across cold fronts Stability of cold fronts . . . Rayleigh-Taylor instability. Kelvin-Helmholtz instability. Possible future measurements using cold fronts . . . Plasma depletion layer and magnetic field. Effective viscosity of ICM. SHOCK FRONTS AS EXPERIMENTAL TOOL Cluster merger shocks Mach number determination Front width Mach cone and reverse shock? Test of electron-ion equilibrium . . . Comparison with other astrophysical plasmas Shocks and cluster cosmic ray population . . . Shock acceleration. Compression of fossil electrons. . . . Yet another method to measure intracluster magnetic field.

  19. Co-Clustering with Generative Models

    E-Print Network [OSTI]

    Golland, Polina

    2009-11-03T23:59:59.000Z

    In this paper, we present a generative model for co-clustering and develop algorithms based on the mean field approximation for the corresponding modeling problem. These algorithms can be viewed as generalizations of the ...

  20. Photoelectron Spectroscopy of Cold Hydrated Sulfate Clusters...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    sulfate clusters SO42-(H2O)n (n ) 4-7) at 12 K and ab initio studies to understand the structures and dynamics of these unique solvated systems. A significant increase of...

  1. Accelerating semantic graph databases on commodity clusters

    SciTech Connect (OSTI)

    Morari, Alessandro; Castellana, Vito G.; Haglin, David J.; Feo, John T.; Weaver, Jesse R.; Tumeo, Antonino; Villa, Oreste

    2013-10-06T23:59:59.000Z

    We are developing a full software system for accelerating semantic graph databases on commodity cluster that scales to hundreds of nodes while maintaining constant query throughput. Our framework comprises a SPARQL to C++ compiler, a library of parallel graph methods and a custom multithreaded runtime layer, which provides a Partitioned Global Address Space (PGAS) programming model with fork/join parallelism and automatic load balancing over a commodity clusters. We present preliminary results for the compiler and for the runtime.

  2. Contribution of White Dwarfs to Cluster Masses

    E-Print Network [OSTI]

    Ted von Hippel

    1998-02-14T23:59:59.000Z

    I present a literature search through 31 July 1997 of white dwarfs (WDs) in open and globular clusters. There are 36 single WDs and 5 WDs in binaries known among 13 open clusters, and 340 single WDs and 11 WDs in binaries known among 11 globular clusters. From these data I have calculated WD mass fractions for four open clusters (the Pleiades, NGC 2168, NGC 3532, and the Hyades) and one globular cluster (NGC 6121). I develop a simple model of cluster evolution that incorporates stellar evolution but not dynamical evolution to interpret the WD mass fractions. I augment the results of my simple model with N-body simulations incorporating stellar evolution (Terlevich 1987; de la Feunte Marcos 1996; Vesperini & Heggie 1997). I find that even though these clusters undergo moderate to strong kinematical evolution the WD mass fraction is relatively insensitive to kinematical evolution. By comparing the cluster mass functions to that of the Galactic disk, and incorporating plausibility arguments for the mass function of the Galactic halo, I estimate the WD mass fraction in these two populations. I assume the Galactic disk is ~10 Gyrs old (Winget et al. 1987; Liebert, Dahn, & Monet 1988; Oswalt et al. 1996) and that the Galactic halo is ~12 Gyrs old (Reid 1997b; Gratton et al. 1997; Chaboyer et al. 1998), although the WD mass fraction is insensitive to age in this range. I find that the Galactic halo should contain 8 to 9% (alpha = -2.35) or perhaps as much as 15 to 17% (alpha = -2.0) of its stellar mass in the form of WDs. The Galactic disk WD mass fraction should be 6 to 7% (alpha = -2.35), consistent with the empirical estimates of 3 to 7% (Liebert, Dahn, & Monet 1988; Oswalt et al. 1996). (abridged)

  3. The Efficiency of Globular Cluster Formation

    E-Print Network [OSTI]

    Dean E. McLaughlin

    1999-01-21T23:59:59.000Z

    (Abridged): The total populations of globular cluster systems (GCSs) are discussed in terms of their connection to the efficiency of globular cluster formation---the mass fraction of star-forming gas that was able to form bound stellar clusters rather than isolated stars or unbound associations---in galaxy halos. Observed variations in GCS specific frequencies (S_N=N_gc/L_gal), both as a function of galactocentric radius in individual systems and globally between entire galaxies, are reviewed in this light. It is argued that trends in S_N do not reflect any real variation in the underlying efficiency of cluster formation; rather, they result from ignoring the hot gas in many large ellipticals. This claim is checked and confirmed in each of M87, M49, and NGC 1399, for which existing data are combined to show that the volume density profile of globular clusters, rho_cl, is directly proportional to the sum of (rho_gas+rho_stars) at large radii. The constant of proportionality is the same in each case: epsilon=0.0026 +/- 0.0005 in the mean. This is identified with the globular cluster formation efficiency. The implication that epsilon might have had a universal value is supported by data on the GCSs of 97 early-type galaxies, on the GCS of the Milky Way, and on the ongoing formation of open clusters. These results have specific implications for some issues in GCS and galaxy formation, and they should serve as a strong constraint on more general theories of star and cluster formation.

  4. Microsoft Word - JWS Sample.doc

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    7 SAMPLE ONLY REV2021005 SAMPLE ONLY Joint Work Statement For CRADA No. Sample BETWEEN U. S. Department of Energy Naval Petroleum Reserve No. 3 Rocky Mountain Oilfield Testing...

  5. Feedback from Clustered Sources During Reionization

    E-Print Network [OSTI]

    Roban Hultman Kramer; Zoltan Haiman; S. Peng Oh

    2006-04-10T23:59:59.000Z

    The reionization history of the intergalactic medium (IGM) at high redshift (z > 6) was likely strongly shaped by several global feedback processes. Because the earliest ionizing sources formed at the locations of the rare density peaks, their spatial distribution was strongly clustered. Here we demonstrate that this clustering significantly boosts the impact of feedback processes operating at high redshift. We build a semi-analytical model to include feedback and clustering simultaneously, and apply this model to the suppression of star-formation in minihalos due to photoionization. The model is built on the excursion-set-based formalism of Furlanetto, Zaldarriaga and Hernquist (2004), which incorporates the clustering of ionizing sources, and which we here extend to include suppression of star formation in minihalos. We find that clustering increases the mean HII bubble size by a factor of several, and it dramatically increases the fraction of minihalos that are suppressed, by a factor of up to 60 relative to a randomly distributed population. This enhanced suppression can significantly reduce the electron scattering optical depth, as required by the three-year data from the Wilkinson Microwave Anisotropy Probe (WMAP). We argue that source clustering is likely to similarly boost the importance of a variety of other feedback mechanisms.

  6. Cosmological Constraints from Galaxy Cluster Velocity Statistics

    E-Print Network [OSTI]

    Suman Bhattacharya; Arthur Kosowsky

    2007-04-20T23:59:59.000Z

    Future microwave sky surveys will have the sensitivity to detect the kinematic Sunyaev-Zeldovich signal from moving galaxy clusters, thus providing a direct measurement of their line-of-sight peculiar velocity. We show that cluster peculiar velocity statistics applied to foreseeable surveys will put significant constraints on fundamental cosmological parameters. We consider three statistical quantities that can be constructed from a cluster peculiar velocity catalog: the probability density function, the mean pairwise streaming velocity, and the pairwise velocity dispersion. These quantities are applied to an envisioned data set which measures line-of-sight cluster velocities with normal errors of 100 km/s for all clusters with masses larger than $10^{14}$ solar masses over a sky area of up to 5000 square degrees. A simple Fisher matrix analysis of this survey shows that the normalization of the matter power spectrum and the dark energy equation of state can be constrained to better than 10 percent, and the Hubble constant and the primordial power spectrum index can be constrained to a few percent, independent of any other cosmological observations. We also find that the current constraint on the power spectrum normalization can be improved by more than a factor of two using data from a 400 square degree survey and WMAP third-year priors. We also show how the constraints on cosmological parameters changes if cluster velocities are measured with normal errors of 300 km/s.

  7. Free floating planets in stellar clusters?

    E-Print Network [OSTI]

    Kester W. Smith; Ian A. Bonnell

    2001-01-05T23:59:59.000Z

    We have simulated encounters between planetary systems and single stars in various clustered environments. This allows us to estimate the fraction of systems liberated, the velocity distribution of the liberated planets, and the separation and eccentricity distributions of the surviving bound systems. Our results indicate that, for an initial distribution of orbits that is flat in log space and extends out to 50AU, 50% of the available planets can be liberated in a globular cluster, 25% in an open cluster, and less than 10% in a young cluster. These fractions are reduced to 25%, 12% and 2% if the initial population extends only to 20AU. Furthermore, these free-floating planets can be retained for longer than a crossing time only in a massive globular cluster. It is therefore difficult to see how planets, which by definition form in a disc around a young star, could be subsequently liberated to form a significant population of free floating substellar objects in a cluster.

  8. Electron attenuation in free, neutral ethane clusters

    SciTech Connect (OSTI)

    Winkler, M.; Harnes, J.; Børve, K. J., E-mail: Knut.Borve@kj.uib.no [Department of Chemistry, University of Bergen, NO-5007 Bergen (Norway); Myrseth, V. [Department of Physics and Technology, University of Bergen, NO-5007 Bergen (Norway)

    2014-10-28T23:59:59.000Z

    The electron effective attenuation length (EAL) in free, neutral ethane clusters has been determined at 40 eV kinetic energy by combining carbon 1s x-ray photoelectron spectroscopy and theoretical lineshape modeling. More specifically, theory is employed to form model spectra on a grid in cluster size (N) and EAL (?), allowing N and ? to be determined by optimizing the goodness-of-fit ?{sup 2}(N, ?) between model and observed spectra. Experimentally, the clusters were produced in an adiabatic-expansion setup using helium as the driving gas, spanning a range of 100–600 molecules in mean cluster size. The effective attenuation length was determined to be 8.4?±?1.9 Å, in good agreement with an independent estimate of 10 Å formed on the basis of molecular electron-scattering data and Monte Carlo simulations. The aggregation state of the clusters as well as the cluster temperature and its importance to the derived EAL value are discussed in some depth.

  9. Synchronized sampling improves fault location

    SciTech Connect (OSTI)

    Kezunovic, M. [Texas A and M Univ., College Station, TX (United States)] [Texas A and M Univ., College Station, TX (United States); Perunicic, B. [Lamar Univ., Beaumont, TX (United States)] [Lamar Univ., Beaumont, TX (United States)

    1995-04-01T23:59:59.000Z

    Transmission line faults must be located accurately to allow maintenance crews to arrive at the scene and repair the faulted section as soon as possible. Rugged terrain and geographical layout cause some sections of power transmission lines to be difficult to reach. In the past, a variety of fault location algorithms were introduced as either an add-on feature in protective relays or stand-alone implementation in fault locators. In both cases, the measurements of current and voltages were taken at one terminal of a transmission line only. Under such conditions, it may become difficult to determine the fault location accurately, since data from other transmission line ends are required for more precise computations. In the absence of data from the other end, existing algorithms have accuracy problems under several circumstances, such as varying switching and loading conditions, fault infeed from the other end, and random value of fault resistance. Most of the one-end algorithms were based on estimation of voltage and current phasors. The need to estimate phasors introduces additional difficulty in high-speed tripping situations where the algorithms may not be fast enough in determining fault location accurately before the current signals disappear due to the relay operation and breaker opening. This article introduces a unique concept of high-speed fault location that can be implemented either as a simple add-on to the digital fault recorders (DFRs) or as a stand-alone new relaying function. This advanced concept is based on the use of voltage and current samples that are synchronously taken at both ends of a transmission line. This sampling technique can be made readily available in some new DFR designs incorporating receivers for accurate sampling clock synchronization using the satellite Global Positioning System (GPS).

  10. Radio morphology and spectral analysis of cD galaxies in rich and poor galaxy clusters

    E-Print Network [OSTI]

    S. Giacintucci; T. Venturi; M. Murgia; D. Dallacasa; R. Athreya; S. Bardelli; P. Mazzotta; D. J. Saikia

    2007-08-31T23:59:59.000Z

    We present a radio morphological study and spectral analysis for a sample of 13 cD galaxies in rich and poor clusters of galaxies.} Our study is based on new high sensitivity Giant Metrewave Radio Telescope (GMRT) observations at 1.28 GHz, 610 MHz and 235 MHz, and on archival data. From a statistical sample of cluster cD galaxies we selected those sources with little information available in the literature and promising for the detection of aged radio emission. Beyond the high sensitivity images for all 13 radio galaxies, we present also a detailed spectral analysis for 7 of them. We found a variety of morphologies and linear sizes, as typical for radio galaxies in the radio power range sampled here (low to intermediate power radio galaxies). The spectral analysis shows that 10/13 radio galaxies have steep radio spectrum, with spectral index $\\alpha \\ge 1$. In general, the radiative ages and growth velocities are consistent with previous findings that the evolution of radio galaxies at the cluster centres is affected by the dense external medium (i.e. low growth velocities and old ages. We suggest that the dominant galaxies in A 2622 and MKW 03s are dying radio sources, which at present are not fed by nuclear activity. On the other hand, the spectacular source at the centre of A 2372 might be a very interesting example of restarted radio galaxy. For this source we estimated a life cycle of the order of 10$^6$ yr.

  11. Consistent use of type Ia supernovae highly magnified by galaxy clusters to constrain the cosmological parameters

    SciTech Connect (OSTI)

    Zitrin, Adi [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, MS 249-17, Pasadena, CA 91125 (United States); Redlich, Matthias [Universität Heidelberg, Zentrum für Astronomie, Institut für Theoretische Astrophysik, Philosophenweg 12, D-69120 Heidelberg (Germany); Broadhurst, Tom, E-mail: adizitrin@gmail.com [Department of Theoretical Physics, University of Basque Country UPV/EHU, Bilbao (Spain)

    2014-07-01T23:59:59.000Z

    We discuss how Type Ia supernovae (SNe) strongly magnified by foreground galaxy clusters should be self-consistently treated when used in samples fitted for the cosmological parameters. While the cluster lens magnification of a SN can be well constrained from sets of multiple images of various background galaxies with measured redshifts, its value is typically dependent on the fiducial set of cosmological parameters used to construct the mass model. In such cases, one should not naively demagnify the observed SN luminosity by the model magnification into the expected Hubble diagram, which would create a bias, but instead take into account the cosmological parameters a priori chosen to construct the mass model. We quantify the effect and find that a systematic error of typically a few percent, up to a few dozen percent per magnified SN may be propagated onto a cosmological parameter fit unless the cosmology assumed for the mass model is taken into account (the bias can be even larger if the SN is lying very near the critical curves). We also simulate how such a bias propagates onto the cosmological parameter fit using the Union2.1 sample supplemented with strongly magnified SNe. The resulting bias on the deduced cosmological parameters is generally at the few percent level, if only few biased SNe are included, and increases with the number of lensed SNe and their redshift. Samples containing magnified Type Ia SNe, e.g., from ongoing cluster surveys, should readily account for this possible bias.

  12. Tank farm backlog soil sample analysis plan

    SciTech Connect (OSTI)

    Ahlers, J.D., Westinghouse Hanford

    1996-07-17T23:59:59.000Z

    This document describes the measures to collect samples, perform testing on samples, and make decisions to obtain a Contained- in Determination for tank farms backlog soil.

  13. Radioactive Samples / Materials at the APS

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Using Radioactive Samples Materials at the APS The use of radioactive samples requires additional information for review and approval. All proposed experiments involving...

  14. LANSCE | Lujan Center | Chemical & Sample Prep

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Chemical & Sample Preparation For general questions, please contact the Lujan Center Chemical and Sample Preparation Laboratory responsible: Charles Kelsey | ckelsey@lanl.gov |...

  15. Gas Sampling | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489InformationFrenchtown, NewG22 JumpGas Sampling Jump to:

  16. Sample Licensing Agreements | Partnerships | ORNL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's PossibleRadiation Protection245C Unlimited ReleaseWelcome ton6 th US/German Workshop onSample

  17. Sample Retention Incentive Service Agreement

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn'tOrigin ofEnergy atLLC - FE DKT. 10-160-LNG - ORDERSTATE0-1ofEnergy Sample Employee:

  18. Soil Sampling | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:Ezfeedflag JumpID-f < RAPID‎ |RippeyInformationSoda Springs, Idaho:Soil Sampling Jump

  19. Groundwater Sampling | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are8COaBulkTransmissionSitingProcess.pdfGetec AG| Open Energy Information 2000)2004) |1978) |Groundwater Sampling

  20. The Next Generation Virgo Cluster Survey. VI. The Kinematics of Ultra-compact Dwarfs and Globular Clusters in M87

    E-Print Network [OSTI]

    Zhang, Hong-Xin; Cote, Patrick; Liu, Chengze; Ferrarese, Laura; Cuillandre, Jean-Charles; Caldwell, Nelson; Gwyn, Stephen D J; Jordan, Andres; Lancon, Ariane; Li, Biao; Munoz, Roberto P; Puzia, Thomas H; Bekki, Kenji; Blakeslee, John; Boselli, Alessandro; Drinkwater, Michael J; Duc, Pierre-Alain; Durrell, Patrick; Emsellem, Eric; Firth, Peter; Sanchez-Janssen, Ruben

    2015-01-01T23:59:59.000Z

    The origin of ultra-compact dwarfs (UCDs)--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 GCs, is not yet settled. We present the dynamical properties of 97 spectroscopically confirmed UCDs (rh >~10 pc) and 911 GCs associated with central cD galaxy of the Virgo cluster, M87. Our UCDs, of which 89% have M_star > ~2X10^6 M_sun and 92% are as blue as the classic blue GCs, nearly triple the sample of previous confirmed Virgo UCDs, providing by far the best opportunity for studying the global dynamics of a UCD system. We found that (1) UCDs have a surface number density profile that is shallower than that of the blue GCs in the inner ~ 70 kpc and as steep as that of the red GCs at larger radii; (2) UCDs exhibit a significantly stronger rotation than the GCs, and the blue GCs seem to have a velocity fi...

  1. Apparatus for sectioning demountable semiconductor samples

    DOE Patents [OSTI]

    Sopori, Bhushan L. (Scottsdale, AZ); Wolf, Abraham (Sun City West, AZ)

    1984-01-01T23:59:59.000Z

    Apparatus for use during polishing and sectioning operations of a ribbon sample is described. The sample holder includes a cylinder having an axially extending sample cavity terminated in a first funnel-shaped opening and a second slot-like opening. A spring-loaded pressure plunger is located adjacent the second opening of the sample cavity for frictional engagement of the sample prior to introduction of a molding medium in the sample cavity. A heat softenable molding medium is inserted in the funnel-shaped opening, to surround the sample. After polishing, the heater is energized to allow draining of the molding medium from the sample cavity. During manual polishing, the second end of the sample holder is inserted in a support ring which provides mechanical support as well as alignment of the sample holder during polishing. A gauge block for measuring the protrusion of a sample beyond the second wall of the holder is also disclosed.

  2. HUBBLE SPACE TELESCOPE OBSERVATIONS OF A SPECTACULAR NEW STRONG-LENSING GALAXY CLUSTER: MACS J1149.5+2223 AT z = 0.544

    SciTech Connect (OSTI)

    Smith, Graham P. [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham, B15 2TT (United Kingdom); Ebeling, Harald; Ma, Cheng-Jiun [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Limousin, Marceau; Kneib, Jean-Paul; Jauzac, Mathilde [Laboratoire d'Astrophysique de Marseille, CNRS-Universite Aix-Marseille, 38 rue F. Joliot-Curie, 13388 Marseille Cedex 13 (France); Swinbank, A. M.; Richard, Johan; Edge, Alastair C.; Smail, Ian [Institute for Computational Cosmology, Durham University, South Road, Durham, DH1 3LE (United Kingdom); Jullo, Eric [Jet Propulsion Laboratory, California Institute of Technology, MS 169-506, Pasadena, CA 91125 (United States); Sand, David J., E-mail: gps@star.sr.bham.ac.u [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2009-12-20T23:59:59.000Z

    We present Advanced Camera for Surveys observations of MACS J1149.5+2223, an X-ray luminous galaxy cluster at z = 0.544 discovered by the Massive Cluster Survey. The data reveal at least seven multiply imaged galaxies, three of which we have confirmed spectroscopically. One of these is a spectacular face-on spiral galaxy at z = 1.491, the four images of which are gravitationally magnified by 8 approx< mu approx< 23. We identify this as an L* (M{sub B} approx = -20.7), disk-dominated (B/T approx< 0.5) galaxy, forming stars at approx6 M{sub sun} yr{sup -1}. We use a robust sample of multiply imaged galaxies to constrain a parameterized model of the cluster mass distribution. In addition to the main cluster dark matter halo and the bright cluster galaxies, our best model includes three galaxy-group-sized halos. The relative probability of this model is P(N{sub halo} = 4)/P(N{sub halo} < 4) >= 10{sup 12} where N{sub halo} is the number of cluster/group-scale halos. In terms of sheer number of merging cluster/group-scale components, this is the most complex strong-lensing cluster core studied to date. The total cluster mass and fraction of that mass associated with substructures within R <= 500 kpc, are measured to be M{sub tot} = (6.7 +- 0.4) x 10{sup 14} M{sub sun} and f{sub sub} = 0.25 +- 0.12, respectively. Our model also rules out recent claims of a flat density profile at approx>7sigma confidence, thus highlighting the critical importance of spectroscopic redshifts of multiply imaged galaxies when modeling strong-lensing clusters. Overall our results attest to the efficiency of X-ray selection in finding the most powerful cluster lenses, including complicated merging systems.

  3. A populous intermediate-age open cluster and evidence of an embedded cluster among the FSR globular cluster candidates

    E-Print Network [OSTI]

    Bica, Eduardo

    2007-01-01T23:59:59.000Z

    We study the nature of the globular cluster (GC) candidates FSR 1603 and FSR 1755 selected from the catalogue of \\citet{FSRcat}. Their properties are investigated with 2MASS field-star decontaminated photometry, which is used to build colour-magnitude diagrams (CMDs), and stellar radial density profiles (RDPs). FSR 1603 has the open cluster (OC) Ruprecht 101 as optical counterpart, and we show it to be a massive intermediate age cluster (IAC). Relevant parameters of FSR 1603 are the age $\\approx1$ Gyr, distance from the Sun $\\ds\\approx2.7$ kpc, Galactocentric distance $\\dgc\\approx6.4$ kpc, core radius $\\rc\\approx1.1$ pc, mass function slope $\\chi\\approx1.8$, observed stellar mass (for stars with mass in the range $\\rm 1.27 \\ms\\leq m\\leq2.03 \\ms$) $\\mObs\\approx500 \\ms$, and a total (extrapolated to $\\rm m=0.08 \\ms$) stellar mass $\\mTot\\approx2300 \\ms$. FSR 1755, on the other hand, is not a populous cluster. It may be a sparse young cluster embedded in the H II region Sh2-3, subject to an absorption $\\aV\\approx...

  4. ASSOCIATION RULES OF DCI PATIENT CLUSTERS AND RELIABILITY OF CLUSTERING ANALYSIS

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    work:. K-Means Algorithm The k-means method is a widely used geometric clustering algorithm based is guaranteed to terminate. The k-means method is still very popular today, and it has been applied in a wide of the k-means algorithm is the necessity to specify the number of clusters. COBWEB Algorithm Unlike the k-means

  5. Radial velocities of three poorly studied clusters and the kinematics of open clusters

    SciTech Connect (OSTI)

    Hayes, Christian R.; Friel, Eileen D., E-mail: hayescr@indiana.edu, E-mail: efriel@indiana.edu [Astronomy Department, Indiana University, Bloomington, IN 47405 (United States)

    2014-04-01T23:59:59.000Z

    We present radial velocities for stars in the field of the open star clusters Berkeley 44, Berkeley 81, and NGC 6802 from spectra obtained using the Wisconsin-Indiana-Yale-NOAO (WIYN) 3.5 m telescope. These clusters are of intermediate age (1-3 Gyr), located within the solar Galactocentric radius, and have no previous radial velocity measurements. We find mean radial velocities of –9.6 ± 3.0 km s{sup –1}, 48.1 ± 2.0 km s{sup –1}, and 12.4 ± 2.8 km s{sup –1} for Be 44, Be 81, and NGC 6802, respectively. We present an analysis of radial velocities of 134 open clusters of a wide range of ages using data obtained in this study and the literature. Assuming the system of clusters rotates about the Galactic center with a constant velocity, we find older clusters exhibit a slower rotation and larger line-of-sight (LOS) velocity dispersion than younger clusters. The gradual decrease in rotational velocity of the cluster system with age is accompanied by a smooth increase in LOS velocity dispersion, which we interpret as the effect of heating on the open cluster system over time.

  6. Keck Spectroscopy of Globular Clusters in the Virgo Cluster Dwarf Elliptical VCC 1386

    E-Print Network [OSTI]

    Christopher J. Conselice

    2005-11-01T23:59:59.000Z

    We present the results of a Keck spectroscopic study of globular clusters associated with the Virgo Cluster dwarf elliptical VCC 1386. We analyze blue spectroscopic absorption lines from 3500-5500 A for 13 globular cluster candidates and confirm that five are associated with VCC 1386. By comparing metal and Balmer line indices of these globular clusters with alpha-enhanced single stellar population models we find that these systems are metal poor with [Fe/H] 5 Gyr at 3 sigma confidence, placing their formation at z >1. This is one of the first spectroscopic studies of globular clusters surrounding dwarfs in a cluster, revealing that some low mass galaxies in rich environments form at least part of their stellar mass early in the history of the universe. We further find that the luminosity weighted stellar population of VCC 1386 itself is younger, and more metal rich than its globular clusters, consistent with (V-I)_0 colors from Hubble Space Telescope imaging. This implies that VCC 1386, like Local Group dEs, has had multiple episodes of star formation. Globular clusters associated with low luminosity systems however appear to be roughly as old as those associated with giant galaxies, contrary to the `downsizing' formation of their bulk stellar populations.

  7. Magnetospheric line radiation event observed simultaneously on board Cluster 1, Cluster 2 and DEMETER spacecraft

    E-Print Network [OSTI]

    Santolik, Ondrej

    be related to power line harmonic radiation (PLHR, an electromagnetic radiation from electric power systemsMagnetospheric line radiation event observed simultaneously on board Cluster 1, Cluster 2., O. Santolík, M. Parrot, and J. S. Pickett (2012), Magnetospheric line radiation event observed

  8. The Clustering of Luminous Red Galaxies in the Sloan Digital Sky Survey Imaging Data

    E-Print Network [OSTI]

    N. Padmanabhan; D. J. Schlegel; U. Seljak; A. Makarov; N. A. Bahcall; M. R. Blanton; J. Brinkmann; D. J. Eisenstein; D. P. Finkbeiner; J. E. Gunn; D. W. Hogg; Z. Ivezic; G. R. Knapp; J. Loveday; R. H. Lupton; R. C. Nichol; D. P. Schneider; M. A. Strauss; M. Tegmark; D. G. York

    2006-05-15T23:59:59.000Z

    We present the 3D real space clustering power spectrum of a sample of \\~600,000 luminous red galaxies (LRGs) measured by the Sloan Digital Sky Survey (SDSS), using photometric redshifts. This sample of galaxies ranges from redshift z=0.2 to 0.6 over 3,528 deg^2 of the sky, probing a volume of 1.5 (Gpc/h)^3, making it the largest volume ever used for galaxy clustering measurements. We measure the angular clustering power spectrum in eight redshift slices and combine these into a high precision 3D real space power spectrum from k=0.005 (h/Mpc) to k=1 (h/Mpc). We detect power on gigaparsec scales, beyond the turnover in the matter power spectrum, on scales significantly larger than those accessible to current spectroscopic redshift surveys. We also find evidence for baryonic oscillations, both in the power spectrum, as well as in fits to the baryon density, at a 2.5 sigma confidence level. The statistical power of these data to constrain cosmology is ~1.7 times better than previous clustering analyses. Varying the matter density and baryon fraction, we find \\Omega_M = 0.30 \\pm 0.03, and \\Omega_b/\\Omega_M = 0.18 \\pm 0.04, The detection of baryonic oscillations also allows us to measure the comoving distance to z=0.5; we find a best fit distance of 1.73 \\pm 0.12 Gpc, corresponding to a 6.5% error on the distance. These results demonstrate the ability to make precise clustering measurements with photometric surveys (abridged).

  9. INCOHERENCE AND THE PARAMETRIC TEST FRAMEWORK: MISCONCEIVED RELATIONSHIPS AMONG SAMPLE, SAMPLING DISTRIBUTION, AND POPULATION

    E-Print Network [OSTI]

    Yu, Alex

    INCOHERENCE AND THE PARAMETRIC TEST FRAMEWORK: MISCONCEIVED RELATIONSHIPS AMONG SAMPLE, SAMPLING Keywords: Parametric test, sample, population, sampling distributions Parametric tests are frequently parametric tests, nor hold beliefs that are consistent with that framework. The parametric test framework

  10. Fractal Dimensions of a Weakly Clustered Distribution and the Scale of Homogeneity

    E-Print Network [OSTI]

    J. S. Bagla; Jaswant Yadav; T. R. Seshadri

    2008-08-04T23:59:59.000Z

    Homogeneity and isotropy of the universe at sufficiently large scales is a fundamental premise on which modern cosmology is based. Fractal dimensions of matter distribution is a parameter that can be used to test the hypothesis of homogeneity. In this method, galaxies are used as tracers of the distribution of matter and samples derived from various galaxy redshift surveys have been used to determine the scale of homogeneity in the Universe. Ideally, for homogeneity, the distribution should be a mono-fractal with the fractal dimension equal to the ambient dimension. While this ideal definition is true for infinitely large point sets, this may not be realised as in practice, we have only a finite point set. The correct benchmark for realistic data sets is a homogeneous distribution of a finite number of points and this should be used in place of the mathematically defined fractal dimension for infinite number of points (D) as a requirement for approach towards homogeneity. We derive the expected fractal dimension for a homogeneous distribution of a finite number of points. We show that for sufficiently large data sets the expected fractal dimension approaches D in absence of clustering. It is also important to take the weak, but non-zero amplitude of clustering at very large scales into account. In this paper we also compute the expected fractal dimension for a finite point set that is weakly clustered. Clustering introduces departures in the Fractal dimensions from D and in most situations the departures are small if the amplitude of clustering is small. Features in the two point correlation function, like those introduced by Baryon Acoustic Oscillations (BAO) can lead to non-trivial variations in the Fractal dimensions where the amplitude of clustering and deviations from D are no longer related in a monotonic manner.

  11. Quantitative Morphology of Galaxies in the Core of the Coma Cluster

    E-Print Network [OSTI]

    C. M. Gutierrez; I. Trujillo; J. A. L. Aguerri; A. W. Graham; N. Caon

    2003-10-19T23:59:59.000Z

    We present a quantitative morphological analysis of 187 galaxies in a region covering the central 0.28 square degrees of the Coma cluster. Structural parameters from the best-fitting Sersic r^{1/n} bulge plus, where appropriate, exponential disc model, are tabulated here. This sample is complete down to a magnitude of R=17 mag. By examining the Edwards et al. (2002) compilation of galaxy redshifts in the direction of Coma, we find that 163 of the 187 galaxies are Coma cluster members, and the rest are foreground and background objects. For the Coma cluster members, we have studied differences in the structural and kinematic properties between early- and late-type galaxies, and between the dwarf and giant galaxies. Analysis of the elliptical galaxies reveals correlations among the structural parameters similar to those previously found in the Virgo and Fornax clusters. Comparing the structural properties of the Coma cluster disc galaxies with disc galaxies in the field, we find evidence for an environmental dependence: the scale lengths of the disc galaxies in Coma are 30% smaller. A kinematical analysis shows marginal differences between the velocity distributions of ellipticals with Sersic index n2 (giants); the dwarf galaxies having a greater (cluster) velocity dispersion. Finally, our analysis of all 421 background galaxies reveals a non-uniform distribution in redshift with contrasts in density ~3, characterized by a void extending from ~10,000 to ~20,000 km s^{-1}, and two dense and extended structures centred at ~20,000 and ~47,000 km s^{-1}.

  12. Agglomerative Connectivity Constrained Clustering for Image Segmentation We consider the problem of clustering under the constraint that data points in the same cluster

    E-Print Network [OSTI]

    Li, Jia

    for images with large sizes, the segmentation algorithm combines the top-down k-means clustering constrained clustering, agglomerative clustering, image segmentation, k-means 1 Introduction Research efforts at multiple stages through which the similarity measure is adjusted. Experimental results with comparison

  13. GALAXY CLUSTER BULK FLOWS AND COLLISION VELOCITIES IN QUMOND

    SciTech Connect (OSTI)

    Katz, Harley; McGaugh, Stacy; Teuben, Peter [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Angus, G. W., E-mail: hkatz@astro.umd.edu, E-mail: stacy.mcgaugh@case.edu, E-mail: teuben@astro.umd.edu, E-mail: angus.gz@gmail.com [Astrophysics, Cosmology and Gravity Centre, University of Cape Town, Private Bag X3, Rondebosch 7700 (South Africa)

    2013-07-20T23:59:59.000Z

    We examine the formation of clusters of galaxies in numerical simulations of a QUMOND cosmogony with massive sterile neutrinos. Clusters formed in these exploratory simulations develop higher velocities than those found in {Lambda}CDM simulations. The bulk motions of clusters attain {approx}1000 km s{sup -1} by low redshift, comparable to observations whereas {Lambda}CDM simulated clusters tend to fall short. Similarly, high pairwise velocities are common in cluster-cluster collisions like the Bullet Cluster. There is also a propensity for the most massive clusters to be larger in QUMOND and to appear earlier than in {Lambda}CDM, potentially providing an explanation for ''pink elephants'' like El Gordo. However, it is not obvious that the cluster mass function can be recovered.

  14. THE FORMATION OF YOUNG DENSE STAR CLUSTERS THROUGH MERGERS

    SciTech Connect (OSTI)

    Fujii, M. S.; Portegies Zwart, S. F. [Leiden Observatory, Leiden University, NL-2300RA Leiden (Netherlands); Saitoh, T. R. [Interactive Research Center of Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, Tokyo 152-8551 (Japan)

    2012-07-01T23:59:59.000Z

    Young star clusters such as NGC 3603 and Westerlund 1 and 2 in the Milky Way and R136 in the Large Magellanic Cloud are dynamically more evolved than expected based on their current relaxation times. In particular, the combination of a high degree of mass segregation, a relatively low central density, and the large number of massive runaway stars in their vicinity are hard to explain with the monolithic formation of these clusters. Young star clusters can achieve such a mature dynamical state if they formed through the mergers of a number of less massive clusters. The shorter relaxation times of less massive clusters cause them to dynamically evolve further by the time they merge, and the merger product preserves the memory of the dynamical evolution of its constituent clusters. With a series of N-body simulations, we study the dynamical evolution of single massive clusters and those that are assembled through merging smaller clusters together. We find that the formation of massive star clusters through the mergers of smaller clusters can reproduce the currently observed spatial distribution of massive stars, the density, and the characteristics (number and mass distribution) of the stars ejected as runaways from young dense clusters. We therefore conclude that these clusters and possibly other young massive star clusters formed through the mergers of smaller clusters.

  15. "Dedicated to Maximizing Planetary Sample Science

    E-Print Network [OSTI]

    Rathbun, Julie A.

    that evaluated sample mass with regards to previous Apollo Program surface activity, scientific productivity and environmentally sensitive samples. (2) This geological sample mass exceeds that of the Apollo 17 mission by only that of the Apollo Program to demonstrate we have progressed beyond Apollo. (3) Using the Apollo sample containers

  16. Bayesian Model-Based Clustering Procedures John W. LAU and Peter J. GREEN

    E-Print Network [OSTI]

    Xu, Xinyi

    of classical approaches, such as hierarchical clustering and K-means clustering procedures, Bayesian a comparison of the statistical performance of the (approximate) optimal clustering with earlier methods

  17. Time Resolved Photoelectron Imaging of Electronic Relaxation Dynamics in Anionic Clusters

    E-Print Network [OSTI]

    Griffin, Graham Bailey

    2009-01-01T23:59:59.000Z

    Solvation in Iodide-Doped Acetonitrile Clusters, Journal ofSolvation in Iodide-doped Acetonitrile Clusters [ReprintedSolvation in Iodide- doped Acetonitrile Clusters", Oli T.

  18. Sample introduction apparatus for a flow cytometer

    DOE Patents [OSTI]

    Van den Engh, Ger (Seattle, WA)

    1998-01-01T23:59:59.000Z

    A sample introduction system for a flow cytometer allows easy change of sample containers such as test tubes and facilitates use in high pressure environments. The sample container includes a cap having a pressure supply chamber and a sample container attachment cavity. A sample container may be automatically positioned into the attachment cavity so as to sealably engage the end of the sample container as its outer surface. This positioning may be accomplished through some sample introduction mechanism. To facilitate cleaning HPLC tubing and fittings may be used in a manner which facilitates removable of the entire tubing from both the nozzle container and other sample container cap to permit its replacement to avoid contamination. The sample container support may include horizontal stops which loosely limit the movement of the sample container and thus avoid further stresses upon it.

  19. Sample introduction system for a flow cytometer

    DOE Patents [OSTI]

    Engh, G. van den

    1997-02-11T23:59:59.000Z

    A sample introduction system for a flow cytometer allows easy change of sample containers such as test tubes and facilitates use in high pressure environments. The sample container includes a cap having a pressure supply chamber and a sample container attachment cavity. A sample container may be automatically positioned into the attachment cavity so as to sealably engage the end of the sample container as its outer surface. This positioning may be accomplished through some sample introduction mechanism. To facilitate cleaning, HPLC tubing and fittings may be used in a manner which facilitates removing of the entire tubing from both the nozzle container and other sample container cap to permit its replacement to avoid contamination. The sample container support may include horizontal stops which loosely limit the movement of the sample container and thus avoid further stresses upon it. 3 figs.

  20. Sample introduction system for a flow cytometer

    DOE Patents [OSTI]

    Van den Engh, Ger (Seattle, WA)

    1997-01-01T23:59:59.000Z

    A sample introduction system for a flow cytometer allows easy change of sample containers such as test tubes and facilitates use in high pressure environments. The sample container includes a cap having a pressure supply chamber and a sample container attachment cavity. A sample container may be automatically positioned into the attachment cavity so as to sealably engage the end of the sample container as its outer surface. This positioning may be accomplished through some sample introduction mechanism. To facilitate cleaning, HPLC tubing and fittings may be used in a manner which facilitates removing of the entire tubing from both the nozzle container and other sample container cap to permit its replacement to avoid contamination. The sample container support may include horizontal stops which loosely limit the movement of the sample container and thus avoid further stresses upon it.

  1. Sample introduction apparatus for a flow cytometer

    DOE Patents [OSTI]

    Van den Engh, G.

    1998-03-10T23:59:59.000Z

    A sample introduction system for a flow cytometer allows easy change of sample containers such as test tubes and facilitates use in high pressure environments. The sample container includes a cap having a pressure supply chamber and a sample container attachment cavity. A sample container may be automatically positioned into the attachment cavity so as to sealably engage the end of the sample container as its outer surface. This positioning may be accomplished through some sample introduction mechanism. To facilitate cleaning HPLC tubing and fittings may be used in a manner which facilitates removable of the entire tubing from both the nozzle container and other sample container cap to permit its replacement to avoid contamination. The sample container support may include horizontal stops which loosely limit the movement of the sample container and thus avoid further stresses upon it. 3 figs.

  2. Detonation of Meta-stable Clusters

    SciTech Connect (OSTI)

    Kuhl, Allen; Kuhl, Allen L.; Fried, Laurence E.; Howard, W. Michael; Seizew, Michael R.; Bell, John B.; Beckner, Vincent; Grcar, Joseph F.

    2008-05-31T23:59:59.000Z

    We consider the energy accumulation in meta-stable clusters. This energy can be much larger than the typical chemical bond energy (~;;1 ev/atom). For example, polymeric nitrogen can accumulate 4 ev/atom in the N8 (fcc) structure, while helium can accumulate 9 ev/atom in the excited triplet state He2* . They release their energy by cluster fission: N8 -> 4N2 and He2* -> 2He. We study the locus of states in thermodynamic state space for the detonation of such meta-stable clusters. In particular, the equilibrium isentrope, starting at the Chapman-Jouguet state, and expanding down to 1 atmosphere was calculated with the Cheetah code. Large detonation pressures (3 and 16 Mbar), temperatures (12 and 34 kilo-K) and velocities (20 and 43 km/s) are a consequence of the large heats of detonation (6.6 and 50 kilo-cal/g) for nitrogen and helium clusters respectively. If such meta-stable clusters could be synthesized, they offer the potential for large increases in the energy density of materials.

  3. Globular cluster luminosity function as distance indicator

    E-Print Network [OSTI]

    Rejkuba, M

    2012-01-01T23:59:59.000Z

    Globular clusters are among the first objects used to establish the distance scale of the Universe. In the 1970-ies it has been recognized that the differential magnitude distribution of old globular clusters is very similar in different galaxies presenting a peak at M_V ~ -7.5. This peak magnitude of the so-called Globular Cluster Luminosity Function has been then established as a secondary distance indicator. The intrinsic accuracy of the method has been estimated to be of the order of ~0.2 mag, competitive with other distance determination methods. Lately the study of the Globular Cluster Systems has been used more as a tool for galaxy formation and evolution, and less so for distance determinations. Nevertheless, the collection of homogeneous and large datasets with the ACS on board HST presented new insights on the usefulness of the Globular Cluster Luminosity Function as distance indicator. I discuss here recent results based on observational and theoretical studies, which show that this distance indica...

  4. Clustering of Aerosols in Atmospheric Turbulent Flow

    E-Print Network [OSTI]

    T. Elperin; N. Kleeorin; M. A. Liberman; V. L'vov; I. Rogachevskii

    2007-02-15T23:59:59.000Z

    A mechanism of formation of small-scale inhomogeneities in spatial distributions of aerosols and droplets associated with clustering instability in the atmospheric turbulent flow is discussed. The particle clustering is a consequence of a spontaneous breakdown of their homogeneous space distribution due to the clustering instability, and is caused by a combined effect of the particle inertia and a finite correlation time of the turbulent velocity field. In this paper a theoretical approach proposed in Phys. Rev. E 66, 036302 (2002) is further developed and applied to investigate the mechanisms of formation of small-scale aerosol inhomogeneities in the atmospheric turbulent flow. The theory of the particle clustering instability is extended to the case when the particle Stokes time is larger than the Kolmogorov time scale, but is much smaller than the correlation time at the integral scale of turbulence. We determined the criterion of the clustering instability for the Stokes number larger than 1. We discussed applications of the analyzed effects to the dynamics of aerosols and droplets in the atmospheric turbulent flow.

  5. Globular Cluster Ages and Stromgren CCD Photometry

    E-Print Network [OSTI]

    Frank Grundahl

    1999-09-23T23:59:59.000Z

    Stromgren uvby CCD photometry can be used in a variety of ways to constrain the absolute and relative ages of globular clusters. The reddening corrected (v-y, c1) diagram offers the means to derive ages that are completely independent of distance. Very precise differential ages for clusters of the same chemical composition may also be determined from such 2-color plots, or from measurements of the magnitude difference, Delta_u, between the subgiant and horizontal branches on the $u-y, u$ plane (where both of these features are flat and well-defined, even for clusters like M13 that have extremely blue HBs on the (B-V, V) diagram). Based on high-quality photometry we find that: (1) M92 is 15 Gyr old, (2) M3 and M13 differ in age by < 1 Gyr, and (3) NGC 288, NGC 362, and NGC 1851 are coeval to within ~1.5 Gyr. These results strongly suggest that age cannot be the only ``second parameter''. Finally, we suggest that the observed variations in c1 among giant branch stars in all the metal-poor clusters that we have studied so far are likely due to star-to-star C and N abundance variations, and potentially indicate that most (if not all) globular clusters have ``primordial'' variations in at least these elements.

  6. Clusters and halos in light nuclei

    E-Print Network [OSTI]

    Thomas Neff

    2012-10-15T23:59:59.000Z

    The fermionic molecular dynamics approach uses Gaussian wave packets as single-particle basis states. Many-body basis states are Slater determinants projected on parity, angular momentum and total linear momentum. The wave-packet basis is very flexible - FMD contains harmonic oscillator shell model and Brink-type cluster states as special cases. The parameters of the wave packets are obtained by variation. A realistic effective interaction derived from the Argonne V18 interaction by means of the unitary correlation operator method is employed. We discuss the fully microscopic calculation of the 3He(alpha,gamma)7Be capture reaction within the FMD approach. The model space contains frozen cluster configurations at large distances and polarized configurations in the interaction region. The polarized configurations are essential for a successful description of the 7Be bound state properties and for the S- and D-wave scattering states. The calculated cross section agrees well with recent measurements regarding both the absolute normalization and the energy dependence. We also discuss the structure of the cluster states, including the famous Hoyle state, in 12C. From the two-body densities we conclude that the Hoyle state has a spatially extended triangular alpha-cluster structure, whereas the third 0+ state features a chain-like obtuse triangle structure. We also calculate the N hbar Omega decomposition of our wave functions to illuminate the challenges of no-core shell model calculations for these cluster states.

  7. Angular clustering in the SUMSS radio survey

    E-Print Network [OSTI]

    Chris Blake; Tom Mauch; Elaine M. Sadler

    2003-10-05T23:59:59.000Z

    We measure the angular correlation function of radio galaxies selected by the 843 MHz Sydney University Molonglo Sky Survey (SUMSS). We find that the characteristic imprint of large-scale structure is clearly detectable, and that the survey is very uniform. Through comparison with similar analyses for other wide-area radio surveys - the 1400 MHz NRAO VLA Sky Survey (NVSS) and the 325 MHz Westerbork Northern Sky Survey (WENSS) - we are able to derive consistent angular clustering parameters, including a steep slope for the clustering function, $w(\\theta) \\propto \\theta^{-1.1}$. We revise upwards previous estimates of the NVSS clustering amplitude, and find no evidence for dependence of clustering properties on radio frequency. It is important to incorporate the full covariance matrix when fitting parameters to the measured correlation function. Once the redshift distribution for mJy radio galaxies has been determined, these projected clustering measurements will permit a robust description of large-scale structure at $z \\sim 0.8$, the median redshift of the sources.

  8. Confirming EIS Clusters. Multi-object Spectroscopy

    E-Print Network [OSTI]

    A. Biviano; M. Ramella; W. Boschin; S. Bardelli; M. Scodeggio; L. N. da Costa; L. F. Olsen; M. Nonino; S. Borgani; M. Girardi

    1999-10-26T23:59:59.000Z

    Using EFOSC2 at the 3.6m ESO telescope, we obtained redshifts for 68 galaxies in the field of six cluster candidates from the ESO Imaging Survey (EIS). The cluster candidates were selected in the EIS patches C and D and have estimated mean redshifts between z=0.5 and z=0.7. In the six candidate cluster fields, we identify possible systems of galaxies in the redshift space. The likelihoods of these systems are established by comparison with random resamplings of the Canada-France Redshift Surveys, and using the redshift distribution expected from Postman et al.'s luminosity function, with Poggianti's K- and evolutionary-corrections. Four of the six candidate EIS clusters are found to correspond to a real system in the redshift space, with > 95 % probability. Two of them have a mean redshift in agreement with the estimate from the matched filter algorithm, while the other two have a significantly smaller redshift. The independent analysis of the V-I vs. I color-magnitude diagrams for five of our six cluster fields, supports our conclusions based on the spectroscopic data.

  9. Multi-object spectroscopy of low redshift EIS clusters. I

    E-Print Network [OSTI]

    L. Hansen; L. F. Olsen; H. E. Jorgensen

    2002-04-23T23:59:59.000Z

    We report the results of the first multi-object spectroscopic observations at the Danish 1.54m telescope at La Silla, Chile. Observations of five cluster candidates from the ESO Imaging Survey Cluster Candidate Catalog are described. From these observations we confirm the reality of the five clusters with measured redshifts of 0.11<=z<=0.35. We estimate velocity dispersions in the range 294-621km/s indicating rather poor clusters. This, and the measured cluster redshifts are consistent with the results of the matched filter procedure applied to produce the Cluster Candidate Catalog.

  10. Nonlinear Gravitational Clustering in Expanding Universe

    E-Print Network [OSTI]

    T. Padmanabhan

    1996-07-19T23:59:59.000Z

    The gravitational clustering of collisionless particles in an expanding universe is modelled using some simple physical ideas. I show that it is possible to understand the nonlinear clustering in terms of three well defined regimes: (1) linear regime; (2) quasilinear regime which is dominated by scale-invariant radial infall and (3) nonlinear regime dominated by nonradial motions and mergers. Modelling each of these regimes separately I show how the nonlinear two point correlation function can be related to the linear correlation function in hierarchical models. This analysis leads to results which are in good agreement with numerical simulations thereby providing an explanation for numerical results. Using this model and some simple extensions, it is possible to understand the transfer of power from large to small scales and the behaviour of higher order correlation functions. The ideas presented here will also serve as a powerful analytical tool to investigate nonlinear clustering in different models.

  11. Spectroscopic Constraints on the Stellar Population of Elliptical Galaxies in the Coma Cluster

    E-Print Network [OSTI]

    Bahram Mobasher; Phil. A. James

    2000-02-26T23:59:59.000Z

    Near-IR spectra for a sample of 31 elliptical galaxies in the Coma cluster are obtained. The galaxies are selected to be ellipticals (no lenticulars), with a large spatial distribution, covering both the core and outskirt of the cluster (ie. corresponding to regions with large density contrasts). Spectroscopic CO (2.3 micron) absorption indices, measuring contribution from intermediate-age red giant and supergiant stars to the near-IR light of the ellipticals, are then estimated. It is found that the strength of spectroscopic CO features in elliptical galaxies increases from the core (r 0.2 deg) of the Coma cluster. Using the Mg2 strengths, it is shown that the observed effect is not due to metallicity and is mostly caused by the presence of a younger population (giant and supergiant stars) in ellipticals in outskirts (low density region) of the cluster. Using the spectroscopic CO features, the origin of the scatter on the near-IR Fundamental Plane of elliptical galaxies is studied. Correcting this relation for contributions from the red giant and supergiant stars, the rms scatter reduces from 0.077dex to 0.073dex. Although measurable, the contribution from these intermediate-age stars to the scatter on the near-IR Fundamental Plane of ellipticals is only marginal. A relation is found between the CO and V-K colours of ellipticals with a slope 0.036 +/- 0.016. This is studied using stellar synthesis models.

  12. Very Small Array observations of the Sunyaev-Zel'dovich effect in nearby galaxy clusters

    E-Print Network [OSTI]

    Katy Lancaster; Ricardo Genova-Santos; Nelson Falcon; Keith Grainge; Carlos Gutierrez; Ruediger Kneissl; Phil Marshall; Guy Pooley; Rafael Rebolo; Jose-Alberto Rubino-Martin; Richard D. E. Saunders; Elizabeth Waldram; Robert A. Watson

    2004-12-02T23:59:59.000Z

    We present VSA observations (~34GHz) on scales ~20 arcmin towards a complete, X-ray-flux-limited sample of seven clusters at redshift z<0.1. Four have significant SZ detections in the presence of CMB primordial anisotropy. We use a bayesian MCMC method for inference from the VSA data, with X-ray priors on cluster positions and temperatures, and radio priors on sources. We make assumptions of beta-model gas distributions and of hydrostatic equilibrium, to evaluate probability densities for the gas mass and total mass out to r_200. Our combined estimate of the gas fraction is 0.08^{+0.06}_{-0.04}h^{-1} The random errors are poor (note that the errors are higher than would have been obtained with the usual chi-squared method) but the control of bias is good. We have described the MCMC analysis method specifically in terms of SZ but hope the description will be of more general use. We find that the effects of primordial CMB contamination tend to be similar in the estimates of both the gas mass and total mass over our narrow range of angular scales, so that there is little effect of primordials on the gas fraction determination. Using our total mass estimates we find a normalisation of the mass-temperature relation based on the profiles from the VSA cluster pressure maps that is in good agreement with recent M-T determinations from X-ray cluster measurements.

  13. Luminous Red Galaxies in Clusters: Central Occupation, Spatial Distributions, and Mis-centering

    E-Print Network [OSTI]

    Hoshino, Hanako; Lackner, Claire; Hikage, Chiaki; Rozo, Eduardo; Rykoff, Eli; Mandelbaum, Rachel; More, Surhud; More, Anupreeta; Saito, Shun; Vulcani, Benedetta

    2015-01-01T23:59:59.000Z

    Luminous Red Galaxies (LRG) from the Sloan Digital Sky Survey are considered among the best understood samples of galaxies, and they are employed in a broad range of cosmological studies. Because they form a relatively homogeneous population, with high stellar masses and red colors, they are expected to occupy halos in a relatively simple way. In this paper, we study how LRGs occupy massive halos via direct counts in clusters and we reveal several unexpected trends suggesting that the connection between LRGs and dark matter halos may not be straightforward. Using the redMaPPer cluster catalog, we derive the central occupation of LRGs as a function richness, Ncen({\\lambda}). Assuming no correlation between cluster mass and central galaxy luminosity at fixed richness, we show that clusters contain a significantly lower fraction of central LRGs than predicted from the two-point correlation function. At halo masses of 10^14.5 Msun, we find Ncen=0.73, compared to Ncen of 0.89 from correlation studies. Our central ...

  14. Stellar rotation, binarity, and lithium in the open cluster IC4756

    E-Print Network [OSTI]

    Strassmeier, Klaus G; Granzer, Thomas; Bihain, Gabriel; Weber, Michael; Barnes, Sydney A

    2015-01-01T23:59:59.000Z

    An important aspect in the evolutionary scenario of cool stars is their rotation and the rotationally induced magnetic activity and interior mixing. Stars in open clusters are particularly useful tracers for these aspects because of their known ages. We aim to characterize the open cluster IC4756 and measure stellar rotation periods and surface differential rotation for a sample of its member stars. Thirty-seven cluster stars were observed continuously with the CoRoT satellite for 78 days in 2010. Follow-up high-resolution spectroscopy of the CoRoT targets and deep Str\\"omgren $uvby\\beta$ and H$\\alpha$ photometry of the entire cluster were obtained with our robotic STELLA facility and its echelle spectrograph and wide-field imager, respectively. We determined high-precision photometric periods for 27 of the 37 CoRoT targets and found values between 0.155 and 11.4 days. Twenty of these are rotation periods. Twelve targets are spectroscopic binaries of which 11 were previously unknown; orbits are given for six ...

  15. An explanation for long flares from extragalactic globular cluster X-ray sources

    E-Print Network [OSTI]

    Thomas J. Maccarone

    2005-09-21T23:59:59.000Z

    Repeatedly flaring X-ray binaries have recently been discovered in NGC 4697 by Sivakoff and collaborators. We show that these flares can be explained as the result of eccentric binaries in globular clusters which accrete more rapidly at periastron than during the rest of the binary orbit. We show that theoretical timescales for producing eccentricities and circularising the binaries are consistent with what is needed to produce the observed population of flaring sources, although the circularisation timescales are highly uncertain on both observational and theoretical grounds. This model makes two clear theoretical predictions (1) the flares should be seen to be strictly periodic if adequate sampling is provided, and that periodicity should be of approximately 15 hours (2) this class of flaring behaviour should be seen only in globular cluster sources, and predominantly in the densest globular clusters. We also test the model for producing eccentricities through fly-by's of a third star near the binary in a globular cluster against a much larger database of millisecond pulsar observations than has been used in past work, and find that the theoretical cross sections for producing eccentricity in binaries are in reasonable agreement with most of the data, provided that the pulsar ages are about $4\\times10^9$ years.

  16. GeV Gamma-ray Flux Upper Limits from Clusters of Galaxies

    E-Print Network [OSTI]

    al., M Ackermann et

    2010-01-01T23:59:59.000Z

    The detection of diffuse radio emission associated with clusters of galaxies indicates populations of relativistic leptons infusing the intracluster medium. Those electrons and positrons are either injected into and accelerated directly in the intracluster medium, or produced as secondary pairs by cosmic-ray ions scattering on ambient protons. Radiation mechanisms involving the energetic leptons together with decay of neutral pions produced by hadronic interactions have the potential to produce abundant GeV photons. Here, we report on the search for GeV emission from clusters of galaxies using data collected by the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope (Fermi) from August 2008 to February 2010. Thirty-three galaxy clusters have been selected according to their proximity and high mass, X-ray flux and temperature, and indications of non-thermal activity for this study. We report upper limits on the photon flux in the range 0.2-100 GeV towards a sample of observed clusters (typical va...

  17. $XMM-Newton$ $?$ project: III. Gas mass fraction shape in high redshift clusters

    E-Print Network [OSTI]

    Rachida Sadat; Alain Blanchard; Sebastien C. Vauclair; David H. Lumb; James Bartlett; A. K. Romer; Jean-Philippe Bernard; Michel Boer; Philippe Marty; Jukka Nevalainen; Douglas J. Burke; C. A. Collins; Robert C. Nichol

    2005-03-19T23:59:59.000Z

    We study the gas mass fraction, $f\\_{\\rm gas},$ behavior in $XMM-Newton$ $\\Omega$ project. The typical $f\\_{\\rm gas}$ shape of high redshift galaxy clusters follows the global shape inferred at low redshift quite well. This result is consistent with the gravitational instability picture leading to self similar structures for both the dark and baryonic matter. However, the mean $f\\_{\\rm gas} in distant clusters shows some differences to local ones, indicating a departure from strict scaling. This result is consistent with the observed evolution in the luminosity-temperature relation. We quantitatively investigate this departure from scaling laws. Within the local sample we used, a moderate but clear variation of the amplitude of the gas mass fraction with temperature is found, a trend that weakens in the outer regions. These variations do not explain departure from scaling laws of our distant clusters. An important implication of our results is that the gas fraction evolution, a test of the cosmological parameters, can lead to biased values when applied at radii smaller than the virial radius. From our $XMM$ clusters, the apparent gas fraction at the virial radius is consistent with a non-evolving universal value in a high matter density model and not with a concordance.

  18. The double galaxy cluster Abell 2465 - II. Star formation in the cluster

    E-Print Network [OSTI]

    Wegner, Gary A; Hwang, Ho Seong

    2014-01-01T23:59:59.000Z

    We investigate the star formation rate and its location in the major merger cluster Abell 2465 at $z$ = 0.245. Optical properties of the cluster are described in Paper I. Measurements of the H$\\alpha$ and infrared dust emission of galaxies in the cluster were made with an interference filter centred on the redshifted line at a wavelength of 817 nm and utilized data from the WISE satellite 12 $\\mu$m band. Imaging in the Johnson $U$ and $B$ bands was obtained, and along with SDSS $u$ and $r$ was used to study the blue fraction, which appears enhanced, as a further signatures of star formation in the cluster. Star formation rates were calculated using standard calibrations. The total star formation rate normalized by the cluster mass, $\\Sigma SFR/M_{cl}$ compared to compilations for other clusters indicate that the components of Abell 2465 lie above the mean $z$ and $M_{cl}$ relations, suggestive that interacting galaxy clusters have enhanced star formation. The projected radial distribution of the star forming ...

  19. Multi-object spectroscopy of low redshift EIS clusters. III. Properties of optically selected clusters

    E-Print Network [OSTI]

    L. F. Olsen; C. Benoist; L. da Costa; L. Hansen; H. E. Jorgensen

    2005-02-25T23:59:59.000Z

    We have carried out an investigation of the properties of low redshift EIS clusters using both spectroscopy and imaging data. We present new redshifts for 738 galaxies in 21 ESO Imaging Survey (EIS) Cluster fields. We use the ``gap''-technique to search for significant overdensities in redshift space and to identify groups/clusters of galaxies corresponding to the original EIS matched filter cluster candidates. In this way we spectroscopically confirm 20 of the 21 cluster candidates with a matched-filter estimated redshift z_MF=0.2. We have now obtained spectroscopic redshifts for 34 EIS cluster candidates with z_MF=0.2 (see also Hansen et al., 2002; Olsen et al., 2003). Of those we spectroscopically confirm 32 with redshifts ranging from z=0.064 to 0.283. We find that: 1) the velocity dispersions of the systems range from sigma_v<=130km/s to sigma_v=1200km/s, typical of galaxy groups to rich clusters; 2) richnesses corresponding to Abell classes R<=1; and 3) concentration indices ranging from C=0.2 to C=1.2. From the analysis of the colours of the galaxy populations we find that 53% of the spectroscopically confirmed systems have a ``significant'' red sequence. These systems are on average richer and have higher velocity dispersions. We find that the colour of the red sequence galaxies matches passive stellar evolution predictions.

  20. Method and apparatus for data sampling

    DOE Patents [OSTI]

    Odell, Daniel M. C. (Aiken, SC)

    1994-01-01T23:59:59.000Z

    A method and apparatus for sampling radiation detector outputs and determining event data from the collected samples. The method uses high speed sampling of the detector output, the conversion of the samples to digital values, and the discrimination of the digital values so that digital values representing detected events are determined. The high speed sampling and digital conversion is performed by an A/D sampler that samples the detector output at a rate high enough to produce numerous digital samples for each detected event. The digital discrimination identifies those digital samples that are not representative of detected events. The sampling and discrimination also provides for temporary or permanent storage, either serially or in parallel, to a digital storage medium.

  1. Method and apparatus for data sampling

    DOE Patents [OSTI]

    Odell, D.M.C.

    1994-04-19T23:59:59.000Z

    A method and apparatus for sampling radiation detector outputs and determining event data from the collected samples is described. The method uses high speed sampling of the detector output, the conversion of the samples to digital values, and the discrimination of the digital values so that digital values representing detected events are determined. The high speed sampling and digital conversion is performed by an A/D sampler that samples the detector output at a rate high enough to produce numerous digital samples for each detected event. The digital discrimination identifies those digital samples that are not representative of detected events. The sampling and discrimination also provides for temporary or permanent storage, either serially or in parallel, to a digital storage medium. 6 figures.

  2. Fluid sampling system for a nuclear reactor

    DOE Patents [OSTI]

    Lau, Louis K. (Monroeville, PA); Alper, Naum I. (Monroeville, PA)

    1994-01-01T23:59:59.000Z

    A system of extracting fluid samples, either liquid or gas, from the interior of a nuclear reactor containment utilizes a jet pump. To extract the sample fluid, a nonradioactive motive fluid is forced through the inlet and discharge ports of a jet pump located outside the containment, creating a suction that draws the sample fluid from the containment through a sample conduit connected to the pump suction port. The mixture of motive fluid and sample fluid is discharged through a return conduit to the interior of the containment. The jet pump and means for removing a portion of the sample fluid from the sample conduit can be located in a shielded sample grab station located next to the containment. A non-nuclear grade active pump can be located outside the grab sampling station and the containment to pump the nonradioactive motive fluid through the jet pump.

  3. Fluid sampling system for a nuclear reactor

    DOE Patents [OSTI]

    Lau, L.K.; Alper, N.I.

    1994-11-22T23:59:59.000Z

    A system of extracting fluid samples, either liquid or gas, from the interior of a nuclear reactor containment utilizes a jet pump. To extract the sample fluid, a nonradioactive motive fluid is forced through the inlet and discharge ports of a jet pump located outside the containment, creating a suction that draws the sample fluid from the containment through a sample conduit connected to the pump suction port. The mixture of motive fluid and sample fluid is discharged through a return conduit to the interior of the containment. The jet pump and means for removing a portion of the sample fluid from the sample conduit can be located in a shielded sample grab station located next to the containment. A non-nuclear grade active pump can be located outside the grab sampling station and the containment to pump the nonradioactive motive fluid through the jet pump. 1 fig.

  4. Sample storage/disposal study

    SciTech Connect (OSTI)

    Valenzuela, B.D.

    1994-09-29T23:59:59.000Z

    Radioactive waste from defense operations has accumulated at the Hanford Site`s underground waste tanks since the late 1940`s. Each tank must be analyzed to determine whether it presents any harm to the workers at the Hanford Site, the public or the environment. Analyses of the waste aids in the decision making process in preparation of future tank waste stabilization procedures. Characterization of the 177 waste tanks on the Hanford Site will produce a large amount of archived material. This also brings up concerns as to how the excess waste tank sample material from 325 and 222-S Analytical Laboratories will be handled. Methods to archive and/or dispose of the waste have been implemented into the 222-S and 325 Laboratory procedures. As the amount of waste characterized from laboratory analysis grows, an examination of whether the waste disposal system will be able to compensate for this increase in the amount of waste needs to be examined. Therefore, the need to find the safest, most economically sound method of waste storage/disposal is important.

  5. Quantitative Morphology of the Intermediate-Redshift Galaxy Cluster Abell 2443 from Ground-Based Imaging -- Evidence for a galaxy concentration index correlation with cluster density

    E-Print Network [OSTI]

    I. Trujillo; J. A. L. Aguerri; C. M. Gutierrez; J. Cepa

    2001-04-18T23:59:59.000Z

    We present broad-band photometry and provide a quantitative analysis of the structure of galaxies in the inner region of the Abell Cluster 2443 (z~0.1). The galaxy parameters have been derived by fitting a two-component model (Sersic r^{1/n} bulge and exponential disk) to a magnitude-limited sample. Using a new method of analysis which takes into account the effects of seeing on the structural parameters and considers the ellipticity as an active parameter, we avoid systematic errors arising from assumptions of circular symmetry. 76% of the sample galaxies were classified with these models, the rest were morphologically peculiar. For the spiral galaxies, the relation between n and B/D is consistent with the trend observed in nearby field galaxy samples. The Sersic index n (which can be considered as a concentration index) of the elliptical galaxies is correlated with the local surface density of the cluster. Monte Carlo simulations were used to check the reliability of the method and determine the magnitude selection criteria.

  6. Dynamic cluster-scaling in DNA

    E-Print Network [OSTI]

    A. Bershadskii

    2010-08-07T23:59:59.000Z

    It is shown that the nucleotide sequences in DNA molecules have cluster-scaling properties (discovered for the first time in turbulent processes: Sreenivasan and Bershadskii, 2006, J. Stat. Phys., 125, 1141-1153.). These properties are relevant to both types of nucleotide pair-bases interactions: hydrogen bonds and stacking interactions. It is shown that taking into account the cluster-scaling properties can help to improve heterogeneous models of the DNA dynamics. Two human genes: BRCA2 and NRXN1, have been considered as examples.

  7. Autoregressive clustering for HMM speech synthesis

    E-Print Network [OSTI]

    Shannon, Matt; Byrne, William

    2010-09-27T23:59:59.000Z

    -estimation formulae used to compute updated parameter values given the state occupancies ?q(t) obtained us- ing the Forward-Backward algorithm [10]. Defining a dummy summarizer f i0(t) , cit for notational convenience, we define accumulators Sideq , X t ?q(t)f id... case we do not split that leaf. Note that (9) depends only on C, C1 and C2 and not on the other clusters, so the order in which we choose to split leaves makes no difference. We can compute the accumulators for an arbitrary cluster just by summing...

  8. Non-thermal phenomena in galaxies clusters

    E-Print Network [OSTI]

    Gianfranco Brunetti

    2004-04-26T23:59:59.000Z

    The discovery of diffuse synchrotron radio emission and, more recently, of the hard X-ray (HXR) tails have triggered a growing interest about non-thermal phenomena in galaxy clusters. After a brief review of the most important evidences for non-thermal emission, I will focus on the origin of the emitting particles and of the hadronic component. In particular I will describe the particle-injection and -acceleration mechanisms at work in the intra-cluster medium (ICM) and, at the same time, discuss the possibility to test current modellings of these phenomena with future radio, HXR, and gamma rays observatories.

  9. Mass Distributions of Clusters Using Gravitational Magnification

    E-Print Network [OSTI]

    Tom Broadhurst

    1995-05-03T23:59:59.000Z

    Lensing in the context of rich clusters is normally quantified from small image distortions, yielding a relative mass distribution in the limit of weak lensing. Here we show the magnification effect of lensing can also be mapped over a cluster, resulting in absolute mass determinations for the weak limit. Furthermore, given both magnification and distortion measurements, the mass distribution may be constrained in the strong regime. Methods for obtaining the magnification using spectroscopic and/or photometric information are discussed, for object detection within a fixed isophote or to a given flux limit. A map of the magnification around A1689 is constructed from the observed depletion of background red galaxy counts.

  10. Dynamical clustering of counterions on flexible polyelectrolytes

    E-Print Network [OSTI]

    Tak Shing Lo; Boris Khusid; Joel Koplik

    2007-07-31T23:59:59.000Z

    Molecular dynamics simulations are used to study the local dynamics of counterion-charged polymer association at charge densities above and below the counterion condensation threshold. Surprisingly, the counterions form weakly-interacting clusters which exhibit short range orientational order, and which decay slowly due to migration of ions across the diffuse double layer. The cluster dynamics are insensitive to an applied electric field, and qualitatively agree with the available experimental data. The results are consistent with predictions of the classical theory only over much longer time scales.

  11. Course Clusters | Photosynthetic Antenna Research Center

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisitingContract Management Fermi Site OfficeCourse Clusters Course Clusters Courses

  12. Metal Enrichment of the Intra-Cluster Medium: Ram-Pressure Stripping of Cluster Galaxies

    E-Print Network [OSTI]

    W. Domainko; W. Kapferer; S. Schindler; E. van Kampen; S. Kimeswenger; M. Mair; M. Ruffert

    2004-05-28T23:59:59.000Z

    We present numerical simulations of the dynamical and chemical evolution of galaxy clusters. X-ray spectra show that the intra-cluster medium contains a significant amount of metals. As heavy elements are produced in the stars of galaxies material from the galaxies must have been expelled to enrich the ambient medium. We have performed hydrodynamic simulations investigating various processes. In this presentation we show the feedback from gas which is stripped from galaxies by ram-pressure stripping. The efficiency, resulting spatial distribution of the metals and the time dependency of this enrichment process on galaxy cluster scale is shown.

  13. Spatial clustering of pixels of a multispectral image

    DOE Patents [OSTI]

    Conger, James Lynn

    2014-08-19T23:59:59.000Z

    A method and system for clustering the pixels of a multispectral image is provided. A clustering system computes a maximum spectral similarity score for each pixel that indicates the similarity between that pixel and the most similar neighboring. To determine the maximum similarity score for a pixel, the clustering system generates a similarity score between that pixel and each of its neighboring pixels and then selects the similarity score that represents the highest similarity as the maximum similarity score. The clustering system may apply a filtering criterion based on the maximum similarity score so that pixels with similarity scores below a minimum threshold are not clustered. The clustering system changes the current pixel values of the pixels in a cluster based on an averaging of the original pixel values of the pixels in the cluster.

  14. ICA-Based Clustering of Genes from Microarray Expression Data

    E-Print Network [OSTI]

    Batzoglou, Serafim

    for microarray analysis, compared to the most widely used methods namely PCA and k-means clustering. We also of independent biological processes. Comparison of clustering performance among various ICA algorithms including

  15. Combining relations and text in scientific network clustering

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    attributes, like hierarchical clustering or k-means [13], [14], [15]. More precisely, unsupervised learning of several data types rises the problem of the meaning of the clustering. Indeed, the different comparison

  16. A Study of Hierarchical Correlation Clustering for Scientific Volume Data

    E-Print Network [OSTI]

    Wang, Chaoli

    hierarchical clustering methods based on qual- ity threshold, k-means, and random walks, to investigate. The evaluation includes side-by-side qualitative comparison of clustering results and quantitative comparison

  17. High density cluster jet target for storage ring experiments

    E-Print Network [OSTI]

    Alexander Täschner; Esperanza Köhler; Hans-Werner Ortjohann; Alfons Khoukaz

    2011-11-02T23:59:59.000Z

    The design and performance of a newly developed cluster jet target installation for hadron physics experiments are presented which, for the first time, is able to generate a hydrogen cluster jet beam with a target thickness of above $10^{15}\\,\\mathrm{atoms/cm}^2$ at a distance of two metres behind the cluster jet nozzle. The properties of the cluster beam and of individual clusters themselves are studied at this installation. Special emphasis is placed on measurements of the target beam density as a function of the relevant parameters as well as on the cluster beam profiles. By means of a time-of-flight setup, measurements of the velocity of single clusters and velocity distributions were possible. The complete installation, which meets the requirements of future internal fixed target experiments at storage rings, and the results of the systematic studies on hydrogen cluster jets are presented and discussed.

  18. Weak lensing flexion as a probe of galaxy cluster substructure

    E-Print Network [OSTI]

    Cain, Benjamin Martin

    2011-01-01T23:59:59.000Z

    Measuring galaxy cluster total masses and the amount of dark matter substructure within galaxy cluster haloes is a fundamental probe of the ACDM model of structure formation, as well as the interactions between baryonic ...

  19. Beltrami Equation and Cluster Lensing: Characteristic Equations and Applications

    E-Print Network [OSTI]

    Schramm; T

    1995-07-24T23:59:59.000Z

    Arclets in clusters of galaxies can be used to determine the lens mapping and not only to constrain the mass density of the cluster. Multiply imaged arclets are therefore easily identified without further modelling.

  20. THE ERA OF STAR FORMATION IN GALAXY CLUSTERS

    E-Print Network [OSTI]

    Brodwin, M.

    We analyze the star formation properties of 16 infrared-selected, spectroscopically confirmed galaxy clusters at 1 < z < 1.5 from the Spitzer/IRAC Shallow Cluster Survey (ISCS). We present new spectroscopic confirmation ...

  1. A COMPARISON OF ARTIFICIAL NEURAL NETWORKS AND CLUSTER ANALYSIS FOR TYPING BIOMETRICS

    E-Print Network [OSTI]

    A COMPARISON OF ARTIFICIAL NEURAL NETWORKS AND CLUSTER ANALYSIS FOR TYPING BIOMETRICS biometrics, artificial neural networks, cluster analysis, Multi Layer Perceptrons, K- means clustering are clustering techniques and Artificial Neural Networks , in conjunction with data processing to improve

  2. Adaptive dimension reduction for clustering high dimensional data

    E-Print Network [OSTI]

    Ding, Chris; He, Xiaofeng; Zha, Hongyuan; Simon, Horst

    2002-01-01T23:59:59.000Z

    theorem. The com- plete ADR-Kmeans algorithm is identical to1: Clustering results of ADM-Kmeans algorithm. Discussions

  3. Studies of nearby poor clusters - A3574 and S753

    SciTech Connect (OSTI)

    Willmer, C.N.A.; Focardi, P.; Chan, R.; Pellegrini, P.S.; Da Costa, N.L. (Observatorio Nacional do Brasil, Rio de Janeiro (Brazil))

    1991-01-01T23:59:59.000Z

    Photometric and spectroscopic data are presented for two clusters, A3574 and S753, belonging to the Centaurus concentration of galaxies. The masses of the clusters are estimated at 1.5 x 10 to the 14th solar masses; no evidence of substructure has been detected in either cluster. The solution of a two-body linear orbit suggests that the clusters do not form a bound system, although the result is marginal. 60 refs.

  4. Bayesian Statistics Stochastic Simulation -Gibbs sampling

    E-Print Network [OSTI]

    Wright, Francis

    Bayesian Statistics Stochastic Simulation - Gibbs sampling Bayesian Statistics - an Introduction Dr Pettit Bayesian Statistics - an Introduction #12;Bayesian Statistics Stochastic Simulation - Gibbs sampling What is Bayesian Statistics? Bayes Theorem The Likelihood Principle Mixtures of conjugate priors

  5. Curve sampling and geometric conditional simulation

    E-Print Network [OSTI]

    Fan, Ayres C. (Ayres Chee), 1978-

    2008-01-01T23:59:59.000Z

    The main objective of this thesis is the development and exploitation of techniques to generate geometric samples for the purpose of image segmentation. A sampling-based approach provides a number of benefits over existing ...

  6. An introduction to boson-sampling

    E-Print Network [OSTI]

    Bryan T. Gard; Keith R. Motes; Jonathan P. Olson; Peter P. Rohde; Jonathan P. Dowling

    2014-06-26T23:59:59.000Z

    Boson-sampling is a simplified model for quantum computing that may hold the key to implementing the first ever post-classical quantum computer. Boson-sampling is a non-universal quantum computer that is significantly more straightforward to build than any universal quantum computer proposed so far. We begin this chapter by motivating boson-sampling and discussing the history of linear optics quantum computing. We then summarize the boson-sampling formalism, discuss what a sampling problem is, explain why boson-sampling is easier than linear optics quantum computing, and discuss the Extended Church-Turing thesis. Next, sampling with other classes of quantum optical states is analyzed. Finally, we discuss the feasibility of building a boson-sampling device using existing technology.

  7. Principles for Sampling Airborne Radioactivity from Stacks

    SciTech Connect (OSTI)

    Glissmeyer, John A.

    2010-10-18T23:59:59.000Z

    This book chapter describes the special processes involved in sampling the airborne effluents from nuclear faciities. The title of the book is Radioactive Air Sampling Methods. The abstract for this chapter was cleared as PNNL-SA-45941.

  8. Multi-Grain Clustering Topic Model (MGCTM)Motivation Evaluation of Document Clustering Integrating Document Clustering and Topic Modeling

    E-Print Network [OSTI]

    Xing, Eric P.

    proportion ·Sample Bernoulli parameter ·For each word (l) (l) ( )Dir (g) (g) ( )Dir ( )Beta w Sample kuwait larson shuttle energy usr motif xterm henrik armenians jews mission dc apr Local topics of 3

  9. Flow Cytometry Instrument Policy & Penalties Sample Preparation

    E-Print Network [OSTI]

    Noble, James S.

    the integrity of the instrument, all samples must be filtered with a 40 µm mesh cell strainer just before

  10. Knowledge Engineering Technique for Cluster Development

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Knowledge Engineering Technique for Cluster Development Pradorn Sureephong1 , Nopasit Chakpitak1 management by using knowledge engineering which is one of the most important method for managing knowledge. This work analyzed three well known knowledge engineering methods, i.e. MOKA, SPEDE and Common

  11. Statistical Learning Theory Nearest Neighbor Clustering

    E-Print Network [OSTI]

    functions such as the k-means objective function, graph cut objective functions, and many others. This consistency result is stronger than most of the existing consistency results in the literature such as for k-means Learning Research, (accepted) (2009). 2. Pollard, D.: Strong Consistency of k-means Clustering. Annals

  12. Clustering with Bregman Divergences Arindam Banerjee

    E-Print Network [OSTI]

    Ghosh, Joydeep

    . The proposed algorithms unify centroid-based parametric clustering approaches, such as classical kmeans main- tain the simplicity and scalability of the classical kmeans algorithm, while generalizing relocation scheme of Euclidean kmeans [14]. The popularity of this algorithm stems from its simplicity

  13. Mixture Models for Clustering and Dimension Reduction

    E-Print Network [OSTI]

    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 3.3 A greedy approach to k-means clustering . . . . . . . . . . . . . . . . . . . 66 3.3.1 The global k-means algorithm . . . . . . . . . . . . . . . . . . . . . 67 3.3.2 Speeding up execution of global k-means . . . . . . . . . . . . . . . 68 3.3.3 Experimental results

  14. TOLERANCE ZONES THROUGH ROBUST CLUSTERING TECHNIQUES

    E-Print Network [OSTI]

    Cuesta, Juan Antonio

    -trimmed observations after a trimmed k-means procedure. Trimmed k-means were introduced in Cuesta-Albertos, Gordaliza and Matr´an (1997) with the aim of robustifying the classical k-means clustering procedure. In this work. References [1] Cuesta-Albertos, J.A., Gordaliza, A. and Matr´an, C. (1997), "Trimmed k-means: An attempt

  15. Molecular Cluster Perturbation Theory. I. Formalism

    E-Print Network [OSTI]

    Jason N. Byrd; Nakul Jindal; Robert W. Molt, Jr.; Rodney J. Bartlett; Beverly A. Sanders; Victor F. Lotrich

    2015-03-23T23:59:59.000Z

    We present second-order molecular cluster perturbation theory (MCPT(2)), a linear scaling methodology to calculate arbitrarily large systems with explicit calculation of individual wavefunctions in a coupled-cluster framework. This new MCPT(2) framework uses coupled-cluster perturbation theory and an expansion in terms of molecular dimer interactions to obtain molecular wavefunctions that are infinite-order in both the electronic fluctuation operator and all possible dimer (and products of dimers) interactions. The MCPT(2) framework has been implemented in the new SIA/Aces4 parallel architecture, making use of the advanced dynamic memory control and fine grained parallelism to perform very large explicit molecular cluster calculations. To illustrate the power of this method, we have computed energy shifts, lattice site dipole moments, and harmonic vibrational frequencies via explicit calculation of the bulk system for the polar and non-polar polymorphs of solid hydrogen fluoride. The explicit lattice size (without using any periodic boundary conditions) was expanded up to 1,000 HF molecules, with 32,000 basis functions and 10,000 electrons. Our obtained HF lattice site dipole moments and harmonic vibrational frequencies agree well with the existing literature.

  16. New nuclear three-body clusters ?{NN}

    E-Print Network [OSTI]

    Vladimir B. Belyaev; Werner Sandhas; Ivan I. Shlyk

    2007-07-31T23:59:59.000Z

    Binding energies of three-body systems of the type \\phi+2N are estimated. Due to the strong attraction between \\phi-meson and nucleon, suggested in different approaches, bound states can appear in systems like \\phi+np (singlet and triplet) and \\phi+pp. This indicates the principal possibility of the formation of new nuclear clusters.

  17. Detecting the Gravitational Redshift of Cluster Gas

    E-Print Network [OSTI]

    Tom Broadhurst; Evan Scannapieco

    2000-03-08T23:59:59.000Z

    We examine the gravitational redshift of radiation emitted from within the potential of a cluster. Spectral lines from the intracluster medium (ICM) are redshifted in proportion to the emission-weighted mean potential along the line of sight, amounting to approximately 50 km/s at a radius of 100 kpc/h, for a cluster dispersion of 1200 km/s. We show that the relative redshifts of different ionization states of metals in the ICM provide a unique probe of the three-dimensional matter distribution. An examination of the reported peculiar velocities of cD galaxies in well studied Abell clusters reveals they are typically redshifted by an average of $\\sim +200$ km/s. This can be achieved by gravity with the addition of a steep central potential associated with the cD galaxy. Note that in general gravitational redshifts cause a small overestimate of the recessional velocities of clusters by an average of $\\sim$ 20 km/s.

  18. College of Engineering High Performance Computing Cluster

    E-Print Network [OSTI]

    Demirel, Melik C.

    College of Engineering High Performance Computing Cluster Policy and Procedures COE-HPC-01 and registered as requiring high performance computing; the course identification/registrations process the College High Performance Computing system will need register for system access by visiting http

  19. Molecular Cluster Perturbation Theory. I. Formalism

    E-Print Network [OSTI]

    Jason N. Byrd; Nakul Jindal; Robert W. Molt, Jr.; Rodney J. Bartlett; Beverly A. Sanders; Victor F. Lotrich

    2015-01-14T23:59:59.000Z

    We present second-order molecular cluster perturbation theory (MCPT(2)), a linear scaling methodology to calculate arbitrarily large systems with explicit calculation of individual wavefunctions in a coupled-cluster framework. This new MCPT(2) framework uses coupled-cluster perturbation theory and an expansion in terms of molecular dimer interactions to obtain molecular wavefunctions that are infinite-order in both the electronic fluctuation operator and all possible dimer (and products of dimers) interactions. The MCPT(2) framework has been implemented in the new SIA/ACES parallel architecture, making use of the advanced dynamic memory control and fine grained parallelism to perform very large explicit molecular cluster calculations. To illustrate the power of this method, we have computed energy shifts and lattice site dipole moments via explicit calculation of the bulk system for the polar and non-polar polymorphs of solid hydrogen fluoride. The explicit lattice size without periodic boundary conditions was expanded up to 1,000 HF molecules, with 32,000 basis functions and 10,000 electrons. Our obtained HF lattice site dipole moments and harmonic vibrational frequencies agree well with the existing literature.

  20. A Binary Method for Fast Computation of Inter and Intra Cluster Similarities for Combining Multiple Clusterings

    E-Print Network [OSTI]

    Mimaroglu, Selim

    . k-means [5] is the best known partitional cluster- ing algorithm. k-means divides a set of objects provides comparison of our new method with the conventional technique for varying size data sets

  1. The Fate of Dwarf Galaxies in Clusters and the Origin of Intracluster Stars. I. Isolated Clusters

    E-Print Network [OSTI]

    Paramita Barai; William Brito; Hugo Martel

    2008-07-02T23:59:59.000Z

    The main goal of this paper is to compare the relative importance of destruction by tides, vs. destruction by mergers, in order to assess if tidal destruction of dwarf galaxies in clusters is a viable scenario for explaining the origin of intracluster stars. We have designed a simple algorithm for simulating the evolution of isolated clusters. The distribution of galaxies in the cluster is evolved using a direct gravitational N-body algorithm combined with a subgrid treatment of physical processes such as mergers, tidal disruption, and galaxy harassment. Using this algorithm, we have performed a total of 227 simulations. Our main results are (1) destruction of dwarf galaxies by mergers dominates over destruction by tides, and (2) the destruction of dwarf galaxies by tides is sufficient to explain the observed intracluster light in clusters.

  2. From nuclear clusters to halo globulars: Star clusters as basic galactic building blocks

    E-Print Network [OSTI]

    Richard de Grijs

    2006-09-05T23:59:59.000Z

    I assess the similarities and differences between the star-formation modes in quiescent spiral galaxies versus those in violent starburst regions, including galactic nuclei. As opposed to the quiescent star-formation mode, current empirical evidence on the star-formation processes in the extreme, high-pressure environments induced by galaxy encounters strongly suggests that star cluster formation is an important and perhaps even the dominant mode of star formation in such starburst events. This implies that by using star clusters as unique diagnostic probes, we can trace a galaxy's most violent star formation history very well, at least for the past few Gyr. The sizes, luminosities, and mass estimates of the young massive star clusters are entirely consistent with what is expected for young Milky Way-type globular clusters (GCs). Recent evidence lends support to the scenario that GCs, which were once thought to be the oldest building blocks of galaxies, are still forming today.

  3. clusterMaker: a multi-algorithm clustering plugin for Cytoscape

    E-Print Network [OSTI]

    2011-01-01T23:59:59.000Z

    than 40% of all known proteins lack any annota- tions withinprotein BH2212 from Bacillus halodurans (gi:15614775) lacksprotein interaction data sets have been clustered to identify stable complexes, but scientists lack

  4. Factor analysis of Galactic globular clusters on structural parameters

    E-Print Network [OSTI]

    O. Eigenson; O. Yatsyk

    2000-11-08T23:59:59.000Z

    Principal component method is used to study galactic globular clusters in 7- and 8-axis space of structural parameters. It is shown that the manifold properties of clusters with this set of parameters is determined mainly by two independent factors. This result may be useful for the theory of formation and evolution of clusters.

  5. Cluster Value Problems in Infinite-Dimensional Spaces

    E-Print Network [OSTI]

    Ortega Castillo, Sofia

    2014-08-05T23:59:59.000Z

    In this dissertation we study cluster value problems for Banach algebras H(B) of analytic functions on the open unit ball B of a Banach space X that contain X* and 1. Solving cluster value problems requires understanding the cluster set of a...

  6. Energy Conservation in Heterogeneous Server Clusters Taliver Heath

    E-Print Network [OSTI]

    Bianchini, Ricardo

    Energy Conservation in Heterogeneous Server Clusters #3; Taliver Heath Dept. of Computer Science, measurement Keywords Energy conservation, server clusters, heterogeneity #3; This research has been supported.g., [3, 4, 9, 21]) and dynamic cluster recon#12;guration for energy conservation without per- formance

  7. An Interactive, Example-Based, Visual Clustering System

    E-Print Network [OSTI]

    An Interactive, Example-Based, Visual Clustering System Pierrick Bruneau 1 and Benoit Otjacques 1 1) Abstract This work describes and evaluates a novel interactive visual clustering system. It combines a 2D projection with a clustering algorithm that operates on this pro- jected data. Users can interact directly

  8. HEAVY GOLD CLUSTER BEAMS production and identi cation

    E-Print Network [OSTI]

    Boyer, Edmond

    . This method is based on the acceleration of the clusters to high energy (MeV) and on the measurement, after to select heavy Aun cluster beams for applications at low energy (keV) in mass spectrometry. 1. Introduction, with a multianode detector 7], the number of constituents coming out of the foil. High energy clusters, accelerated

  9. TIGER:Thermal-Aware File Assignment in Storage Clusters

    E-Print Network [OSTI]

    Qin, Xiao

    energy efficiency of data centers housing storage clusters. Disks have non-negligible thermal impactTIGER:Thermal-Aware File Assignment in Storage Clusters Ajit Chavan, Xunfei Jiang, Mohemmad I/O performance. I. INTRODUCTION Thermal management for power-dense storage clusters can address cooling problems

  10. Robust Control-theoretic Thermal Balancing for Server Clusters

    E-Print Network [OSTI]

    Lu, Chenyang

    Robust Control-theoretic Thermal Balancing for Server Clusters Yong Fu, Chenyang Lu, Hongan Wang for clusters because of the increasing power consumption of modern processors, compact server architectures and growing server density in data centers. Thermal balancing mitigates hot spots in a cluster through dynamic

  11. Automatic Clustering of Grid Nodes Department of Electrical and

    E-Print Network [OSTI]

    Subhlok, Jaspal

    Automatic Clustering of Grid Nodes Qiang Xu Department of Electrical and Computer Engineering Science University of Houston Houston, Texas 77204 Email: jaspal@uh.edu Abstract-- In a grid to an efficient, scalable and portable method of clustering grid nodes and building a distance map among clusters

  12. Spectral Embedded Clustering Feiping Nie1,2

    E-Print Network [OSTI]

    Tsang Wai Hung "Ivor"

    , K-means and Discrimi- native K-means. The experiments on many real- world data sets show that SEC significantly out- performs the existing spectral clustering methods as well as K-means clustering related have been developed such as K-means clustering, mixture models [McLachlan and Peel, 2000], spectral

  13. Visualizing non-hierarchical and hierarchical cluster analyses with

    E-Print Network [OSTI]

    Schonlau, Matt

    are impractical when the data set is large. For non-hierarchical cluster algorithms (e.g. Kmeans) a graph like implementations of the Kmeans algorithm. A data set related to asbestos claims and the Thailand Landmine Data-hierarchical, large data, Kmeans algorithm #12;2 1 Introduction The purpose of cluster analysis is to cluster

  14. Normalized k-means clustering of hyper-rectangles

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Normalized k-means clustering of hyper-rectangles Marie Chavent Math´ematiques Appliqu´ees de-rectangles and their use in two normalized k-means clustering algorithms. Keywords: Interval data, Standardization [Diday, 1988], [Bock and Diday, 2000]. Several works on k-means clustering of interval data sets have

  15. Stability of K-Means Clustering Alexander Rakhlin

    E-Print Network [OSTI]

    Rakhlin, Alexander "Sasha"

    Stability of K-Means Clustering Alexander Rakhlin Department of Computer Science UC Berkeley phrase K-means clustering as an empirical risk minimization procedure over a class HK and explicitly calculate the covering number for this class. Next, we show that stability of K-means clustering

  16. Understanding Complex Network Attack Graphs through Clustered Adjacency Matrices

    E-Print Network [OSTI]

    Noel, Steven

    Understanding Complex Network Attack Graphs through Clustered Adjacency Matrices Steven Noel}@gmu.edu Abstract We apply adjacency matrix clustering to network attack graphs for attack correlation, prediction, and hypothesizing. We self-multiply the clustered adjacency matrices to show attacker reachability across

  17. Aalborg Universitet Hierarchical Control for Multiple DC Microgrids Clusters

    E-Print Network [OSTI]

    Vasquez, Juan Carlos

    Aalborg Universitet Hierarchical Control for Multiple DC Microgrids Clusters Shafiee, Qobad Control for Multiple DC Microgrids Clusters. I E E E Transactions on Energy Conversion. General rights, J. C. Vasquez, and J. M. Guerrero, "Hierarchical Control for Multiple DC-Microgrids Clusters," IEEE

  18. VISCOSITY OF CONCENTRATED SUSPENSIONS: INFLUENCE OF CLUSTER FORMATION

    E-Print Network [OSTI]

    Boyer, Edmond

    1 VISCOSITY OF CONCENTRATED SUSPENSIONS: INFLUENCE OF CLUSTER FORMATION V.Starov1 , V.Zhdanov1 , M and these forces determine both structure and size of clusters. We assume that viscosity of concentrated suspension of viscosity on a concentration of dispersed particles taking into account cluster formation, is deduced. Under

  19. Parametrization of light clusters within relativistic mean field models

    SciTech Connect (OSTI)

    Ferreira, Marcio; Providencia, Constanca [Centro de Fisica Computacional, Department of Physics, University of Coimbra, P-3004-516 Coimbra (Portugal)

    2013-06-10T23:59:59.000Z

    Light clusters are included in the equation of state of nuclearmatter within the relativistic mean field theory. The effect of the cluster-meson coupling constants on the dissolution density is discussed. Theoretical and experimental constraints are used to fix the cluster-meson couplings at T Almost-Equal-To 5 MeV.

  20. cars: A New Code Generation Framework for Clustered ILP Processors

    E-Print Network [OSTI]

    Kailas, Krishnan

    â??glu z Ashok Agrawala \\Lambda y Department of Electrical & Computer Engineering z T. J. Watson Research are characterized by a large number of non­centralized on­chip re­ sources grouped into clusters. Traditional code we present cars, a code generation framework for Clustered ILP processors, which combines the cluster