WorldWideScience

Sample records for legacy survey dark

  1. (Resurveying Mediterranean Rural Landscapes: GIS and Legacy Survey Data

    Directory of Open Access Journals (Sweden)

    Robert Witcher

    2008-07-01

    Full Text Available Legacy data have always been important for Mediterranean archaeologists. Over the past decade, one specific category of legacy data, that deriving from regional survey, has become particularly important. Not only has the scale of research questions become larger (requiring greater reliance on others' data, but the surface archaeological record is deteriorating (diminishing the ability to recover good data. The legacy data from many individual surveys have now been subject to digitisation and GIS analysis, successfully redeploying data collected for one purpose within new theoretical and interpretive frameworks. However, a key research focus is now comparative survey - using the results of many different Mediterranean surveys side-by-side to identify regional variability in settlement organisation, economy and demography. In order to overcome the significant methodological differences between these surveys, attention has focused on the documentation of metadata. Yet, many legacy data lack vital information about their creation and hence how they might be (reinterpreted and compared. GIS has been advanced as an environment in which to contain, order and analyse the data necessary for comparative survey. However, there is a danger that the technology will facilitate inappropriate use of these datasets in a way that fails to acknowledge and understand the very real differences between them. Here, emphasis is placed upon the use of GIS as a space for exploratory data analysis: a process that encompasses and emphasises the integral processes of digitisation, visualisation and simple analysis for the characterisation of datasets in order to derive an alternative form of metadata. Particular emphasis is placed upon the interaction of past human behaviour (e.g. in the Roman period and archaeological recovery (i.e. the behaviour of archaeologists in the present, or recent past; these two sets of 'social action' combine to create distinctive archaeological

  2. CALIFA, the Calar alto legacy integral field area survey

    DEFF Research Database (Denmark)

    Husemann, B.; Jahnke, K.; Sánchez, S. F.

    2013-01-01

    We present the first public data release (DR1) of the Calar Alto Legacy Integral Field Area (CALIFA) survey. It consists of science-grade optical datacubes for the first 100 of eventually 600 nearby (0.005 < z < 0.03) galaxies, obtained with the integral-field spectrograph PMAS/PPak mounted on th...... the available interfaces and tools that allow easy access to this first publicCALIFA data at http://califa.caha.es/DR1.......We present the first public data release (DR1) of the Calar Alto Legacy Integral Field Area (CALIFA) survey. It consists of science-grade optical datacubes for the first 100 of eventually 600 nearby (0.005 ... on the 3.5 m telescope at the Calar Alto observatory. The galaxies in DR1 already cover a wide range of properties in color-magnitude space, morphological type, stellar mass, and gas ionization conditions. This offers the potential to tackle a variety of open questions in galaxy evolution using spatially...

  3. The Dark Energy Survey Image Processing Pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Morganson, E.; et al.

    2018-01-09

    The Dark Energy Survey (DES) is a five-year optical imaging campaign with the goal of understanding the origin of cosmic acceleration. DES performs a 5000 square degree survey of the southern sky in five optical bands (g,r,i,z,Y) to a depth of ~24th magnitude. Contemporaneously, DES performs a deep, time-domain survey in four optical bands (g,r,i,z) over 27 square degrees. DES exposures are processed nightly with an evolving data reduction pipeline and evaluated for image quality to determine if they need to be retaken. Difference imaging and transient source detection are also performed in the time domain component nightly. On a bi-annual basis, DES exposures are reprocessed with a refined pipeline and coadded to maximize imaging depth. Here we describe the DES image processing pipeline in support of DES science, as a reference for users of archival DES data, and as a guide for future astronomical surveys.

  4. Legacy Extragalactic UV Survey (LEGUS) With the Hubble Space Telescope. I. Survey Description

    NARCIS (Netherlands)

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

    2015-01-01

    The Legacy ExtraGalactic UV Survey (LEGUS) is a Cycle 21 Treasury program on the Hubble Space Telescope aimed at the investigation of star formation and its relation with galactic environment in nearby galaxies, from the scales of individual stars to those of ~kiloparsec-size clustered structures.

  5. Millimetre Astronomy Legacy Team 90 GHz Survey (MALT 90)

    Science.gov (United States)

    Jackson, James; Lo, Nadia; Rathborne, Jill; Jones, Paul; Muller, Erik; Cunningham, Maria; Brooks, Kate; Fuller, Gary; Barnes, Peter; Menten, Karl; Schilke, Peter; Garay, Guido; Mardones, Diego; Minier, Vincent; Longmore, Steven; Wyrowski, Friedrich; Herpin, Fabrice; Hill, Tracey; Bronfman, Leonardo; Deharveng, Lise; Schuller, Frederic; Motte, Frédérique; Peretto, Nicolas; Bontemps, Sylvain; Wienen, Marion; Contreras, Yanett; Lenfestey, Clare; Foster, Jonathan; Sanhueza, Patricio; Claysmith, Christopher; Hoq, Sadia

    2012-04-01

    We request Mopra time to complete MALT90, a large, volume-complete survey of high-mass star-forming cores. MALT90 is unique and exploits Mopra's capability for OTF mapping and simultaneous imaging of 16 molecular lines near 90GHz. These molecular lines probe the cores' physical, chemical, and evolutionary state. The target cores are selected from the 870um ATLASGAL survey to host the early stages of high-mass star formation and to span their complete range in evolution. Each core will be mapped at excellent angular (40'') and spectral (0.1km/s) resolution. As in the previous years, fully reduced data products will be made available to the community through the ATOA. In order for MALT90 to be volume-complete, we require 1397 hours to map 942 remaining cores. This time allocation is necessary so that MALT90 is complete to all high-mass cores out to 7kpc: a carefully chosen distance limit to adequate sample a range of Galactic environments and to include all high-mass regions for which individual cores can be resolved with ALMA. When complete, MALT90 will provide an important legacy database for the community and supply the definitive source list of high-mass cores for ALMA.

  6. MALT 90: The Millimeter Astronomy Legacy Team 90 GHz Survey

    Science.gov (United States)

    Jackson, James M.; Foster, J.; Brooks, K.; Rathborne, J.; Longmore, S.

    2011-05-01

    We present the first season results of the Millimeter Astronomy Legacy Team 90 GHz Survey (MALT90), which will image 3 mm molecular line emission from 3,000 dense star-forming cores. MALT90 exploits the capability of the ATNF Mopra 22 m telescope for fast mapping and simultaneous imaging of 16 molecular lines near 90 GHz. These molecular lines will probe the cores’ physical, chemical, and evolutionary state. The target cores are selected from the 870 micron ATLASGAL survey to host the early stages of high-mass star formation and to span the complete range of evolutionary states from pre-stellar cores, to protostellar cores, and on to H II regions. Each core will be mapped at excellent angular (40'') and spectral (0.1 km/s) resolution. We present preliminary results for four key science projects: (1) determining the kinematic distances and Galactic distribution of dense cores, (2) establishing the distribution and evolution of angular momentum in a large sample of high-mass cores, (3) investigating the chemical evolution of dense cores, and (4) comparing the extragalactic molecular line-infrared luminosity correlations with those in Galactic cores. MALT90 will provide the definitive source list of high-mass dense cores for ALMA.

  7. The Dark Energy Survey instrument design

    International Nuclear Information System (INIS)

    Flaugher, B.; Fermilab

    2006-01-01

    We describe a new project, the Dark Energy Survey (DES), aimed at measuring the dark energy equation of state parameter, w, to a statistical precision of ∼5%, with four complementary techniques. The survey will use a new 3 sq. deg. mosaic camera (DECam) mounted at the prime focus of the Blanco 4m telescope at the Cerro-Tololo International Observatory (CTIO). DECam includes a large mosaic camera, a five element optical corrector, four filters (g,r,i,z), and the associated infrastructure for operation in the prime focus cage. The focal plane consists of 62 2K x 4K CCD modules (0.27''/pixel) arranged in a hexagon inscribed within the 2.2 deg. diameter field of view. We plan to use the 250 micron thick fully-depleted CCDs that have been developed at the Lawrence Berkeley National Laboratory (LBNL). At Fermilab, we will establish a packaging factory to produce four-side buttable modules for the LBNL devices, as well as to test and grade the CCDs. R and D is underway and delivery of DECam to CTIO is scheduled for 2009

  8. Stellar Streams in the Dark Energy Survey

    Science.gov (United States)

    Shipp, Nora; Drlica-Wagner, Alex; Balbinot, Eduardo; DES Collaboration

    2018-01-01

    We present a search for Galactic stellar streams in the Dark Energy Survey (DES), using three years of optical data taken across 5000 sq. degrees of the southern sky. The wide-field, uniform DES photometry provides unprecedented sensitivity to the stellar density field in the southern hemisphere, allowing for the detection of faint stellar populations. We follow the “Field of Streams” procedure developed in the Sloan Digital Sky Survey (Belokurov et al., 2006) to identify stellar density features such as dwarf galaxies, globular clusters, and the stellar streams resulting from the tidal disruption of these objects. Improved analysis techniques applied to the DES data enable the discovery of new stellar streams, and provide added insight into the origin and stellar populations of previously identified objects. An increased sample size together with detailed characterization of individual stellar streams and their progenitors can inform our understanding of the formation of the Milky Way stellar halo, as well as the large and small scale distribution of dark matter in the Milky Way.

  9. THE CHANDRA COSMOS LEGACY SURVEY: OPTICAL/IR IDENTIFICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Marchesi, S.; Civano, F.; Urry, C. M. [Yale Center for Astronomy and Astrophysics, 260 Whitney Avenue, New Haven, CT 06520 (United States); Elvis, M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Salvato, M. [Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse 1, D-85748 Garching bei München (Germany); Brusa, M.; Lanzuisi, G.; Vignali, C. [Dipartimento di Fisica e Astronomia, Università di Bologna, viale Berti Pichat 6/2, I-40127 Bologna (Italy); Comastri, A.; Gilli, R.; Zamorani, G.; Cappelluti, N. [INAF—Osservatorio Astronomico di Bologna, via Ranzani 1, I-40127 Bologna (Italy); Hasinger, G. [Institute for Astronomy, 2680 Woodlawn Drive, University of Hawaii, Honolulu, HI 96822 (United States); Miyaji, T. [Instituto de Astronomía sede Ensenada, Universidad Nacional Autónoma de México, Km. 103, Carret. Tijunana-Ensenada, Ensenada, BC (Mexico); Treister, E. [Universidad de Concepción, Departamento de Astronomía, Casilla 160-C, Concepción (Chile); Allevato, V.; Finoguenov, A. [Department of Physics, University of Helsinki, Gustaf Hällströmin katu 2a, FI-00014 Helsinki (Finland); Cardamone, C. [Department of Science, Wheelock College, Boston, MA 02215 (United States); Griffiths, R. E. [Physics and Astronomy Dept., Natural Sciences Division, University of Hawaii at Hilo, 200 W. Kawili Street, Hilo, HI 96720 (United States); Karim, A. [Argelander-Institut für Astronomie, Universität Bonn, Auf dem Hügel 71, D-53121 Bonn (Germany); and others

    2016-01-20

    We present the catalog of optical and infrared counterparts of the Chandra  COSMOS-Legacy  Survey, a 4.6 Ms Chandra  program on the 2.2 deg{sup 2} of the COSMOS field, combination of 56 new overlapping observations obtained in Cycle 14 with the previous C-COSMOS survey. In this Paper we report the i, K, and 3.6 μm identifications of the 2273 X-ray point sources detected in the new Cycle 14 observations. We use the likelihood ratio technique to derive the association of optical/infrared (IR) counterparts for 97% of the X-ray sources. We also update the information for the 1743 sources detected in C-COSMOS, using new K and 3.6 μm information not available when the C-COSMOS analysis was performed. The final catalog contains 4016 X-ray sources, 97% of which have an optical/IR counterpart and a photometric redshift, while ≃54% of the sources have a spectroscopic redshift. The full catalog, including spectroscopic and photometric redshifts and optical and X-ray properties described here in detail, is available online. We study several X-ray to optical (X/O) properties: with our large statistics we put better constraints on the X/O flux ratio locus, finding a shift toward faint optical magnitudes in both soft and hard X-ray band. We confirm the existence of a correlation between X/O and the the 2–10 keV luminosity for Type 2 sources. We extend to low luminosities the analysis of the correlation between the fraction of obscured AGNs and the hard band luminosity, finding a different behavior between the optically and X-ray classified obscured fraction.

  10. The Dark Energy Survey Data Release 1

    Energy Technology Data Exchange (ETDEWEB)

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

    2018-01-09

    We describe the first public data release of the Dark Energy Survey, DES DR1, consisting of reduced single epoch images, coadded images, coadded source catalogs, and associated products and services assembled over the first three years of DES science operations. DES DR1 is based on optical/near-infrared imaging from 345 distinct nights (August 2013 to February 2016) by the Dark Energy Camera mounted on the 4-m Blanco telescope at Cerro Tololo Inter-American Observatory in Chile. We release data from the DES wide-area survey covering ~5,000 sq. deg. of the southern Galactic cap in five broad photometric bands, grizY. DES DR1 has a median delivered point-spread function of g = 1.12, r = 0.96, i = 0.88, z = 0.84, and Y = 0.90 arcsec FWHM, a photometric precision of < 1% in all bands, and an astrometric precision of 151 mas. The median coadded catalog depth for a 1.95" diameter aperture at S/N = 10 is g = 24.33, r = 24.08, i = 23.44, z = 22.69, and Y = 21.44 mag. DES DR1 includes nearly 400M distinct astronomical objects detected in ~10,000 coadd tiles of size 0.534 sq. deg. produced from ~39,000 individual exposures. Benchmark galaxy and stellar samples contain ~310M and ~ 80M objects, respectively, following a basic object quality selection. These data are accessible through a range of interfaces, including query web clients, image cutout servers, jupyter notebooks, and an interactive coadd image visualization tool. DES DR1 constitutes the largest photometric data set to date at the achieved depth and photometric precision.

  11. The Dark Energy Survey Data Management System

    Energy Technology Data Exchange (ETDEWEB)

    Mohr, Joseph J.; /Illinois U., Urbana, Astron. Dept. /Illinois U., Urbana; Barkhouse, Wayne; /North Dakota U.; Beldica, Cristina; /Illinois U., Urbana; Bertin, Emmanuel; /Paris, Inst. Astrophys.; Dora Cai, Y.; /NCSA, Urbana; Nicolaci da Costa, Luiz A.; /Rio de Janeiro Observ.; Darnell, J.Anthony; /Illinois U., Urbana, Astron. Dept.; Daues, Gregory E.; /NCSA, Urbana; Jarvis, Michael; /Pennsylvania U.; Gower, Michelle; /NCSA, Urbana; Lin, Huan; /Fermilab /Rio de Janeiro Observ.

    2008-07-01

    The Dark Energy Survey (DES) collaboration will study cosmic acceleration with a 5000 deg2 griZY survey in the southern sky over 525 nights from 2011-2016. The DES data management (DESDM) system will be used to process and archive these data and the resulting science ready data products. The DESDM system consists of an integrated archive, a processing framework, an ensemble of astronomy codes and a data access framework. We are developing the DESDM system for operation in the high performance computing (HPC) environments at the National Center for Supercomputing Applications (NCSA) and Fermilab. Operating the DESDM system in an HPC environment offers both speed and flexibility. We will employ it for our regular nightly processing needs, and for more compute-intensive tasks such as large scale image coaddition campaigns, extraction of weak lensing shear from the full survey dataset, and massive seasonal reprocessing of the DES data. Data products will be available to the Collaboration and later to the public through a virtual-observatory compatible web portal. Our approach leverages investments in publicly available HPC systems, greatly reducing hardware and maintenance costs to the project, which must deploy and maintain only the storage, database platforms and orchestration and web portal nodes that are specific to DESDM. In Fall 2007, we tested the current DESDM system on both simulated and real survey data. We used TeraGrid to process 10 simulated DES nights (3TB of raw data), ingesting and calibrating approximately 250 million objects into the DES Archive database. We also used DESDM to process and calibrate over 50 nights of survey data acquired with the Mosaic2 camera. Comparison to truth tables in the case of the simulated data and internal crosschecks in the case of the real data indicate that astrometric and photometric data quality is excellent.

  12. The Dark Energy Survey First Data Release

    Science.gov (United States)

    Carrasco Kind, Matias

    2018-01-01

    In this talk I will announce and highlight the main components of the first public data release (DR1) coming from the Dark Energy Survey (DES).In January 2016, the DES survey made available, in a simple unofficial release to the astronomical community, the first set of products. This data was taken and studied during the DES Science Verification period consisting on roughly 250 sq. degrees and 25 million objects at a mean depth of i=23.7 that led to over 80 publications from DES scientist.The DR1 release is the first official release from the main survey and it consists on the observations taken during the first 3 seasons from August 2013 to February 2016 (about 100 nights each season) of the survey which cover the entire DES footprint. All of the Single Epoch Images and the Year 3 Coadded images distributed in 10223 tiles are available for download in this release. The catalogs provide astrometry, photometry and basic classification for near 400M objects in roughly 5000 sq. degrees on the southern hemisphere with a approximate mean depth of i=23.3. Complementary footprint, masking and depth information is also available. All of the software used during the generation of these products are open sourced and have been made available through the Github DES Organization. Images, data and other sub products have been possible through the international and collaborative effort of all 25 institutions involved in DES and are available for exploration and download through the interfaces provided by a partnership between NCSA, NOAO and LIneA.

  13. THE CHANDRA COSMOS-LEGACY SURVEY: THE z > 3 SAMPLE

    Energy Technology Data Exchange (ETDEWEB)

    Marchesi, S.; Civano, F.; Urry, C. M. [Yale Center for Astronomy and Astrophysics, 260 Whitney Avenue, New Haven, CT 06520 (United States); Salvato, M. [Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse 1, D-85748 Garching bei München (Germany); Shankar, F. [Department of Physics and Astronomy, University of Southampton, Highfield, SO17 1BJ (United Kingdom); Comastri, A.; Lanzuisi, G.; Vignali, C.; Zamorani, G.; Brusa, M.; Gilli, R. [INAF–Osservatorio Astronomico di Bologna, via Ranzani 1, 40127 Bologna (Italy); Elvis, M. [Harvard Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Trakhtenbrot, B.; Schawinski, K. [Institute for Astronomy, Department of Physics, ETH Zurich, Wolfgang-Pauli-Strasse 27, CH-8093 Zurich (Switzerland); Allevato, V. [Department of Physics, University of Helsinki, Gustaf Hällströmin katu 2a, FI-00014 Helsinki (Finland); Fiore, F. [INAF–Osservatorio Astronomico di Roma, via di Frascati 33, I-00040 Monte Porzio Catone (Italy); Griffiths, R. [Physics and Astronomy Department, Natural Sciences Division, University of Hawaii at Hilo, 200 W. Kawili Street, Hilo, HI 96720 (United States); Hasinger, G. [Institute for Astronomy, 2680 Woodlawn Drive, University of Hawaii, Honolulu, HI 96822 (United States); Miyaji, T. [Instituto de Astronomía sede Ensenada, Universidad Nacional Autónoma de México, Km. 103, Carret. Tijunana-Ensenada, Ensenada, BC (Mexico); Treister, E. [Universidad de Concepción, Departamento de Astronomía, Casilla 160-C, Concepción (Chile)

    2016-08-20

    We present the largest high-redshift (3 < z < 6.85) sample of X-ray-selected active galactic nuclei (AGNs) on a contiguous field, using sources detected in the Chandra COSMOS-Legacy survey. The sample contains 174 sources, 87 with spectroscopic redshift and the other 87 with photometric redshift (z {sub phot}). In this work, we treat z {sub phot} as a probability-weighted sum of contributions, adding to our sample the contribution of sources with z {sub phot} < 3 but z {sub phot} probability distribution >0 at z > 3. We compute the number counts in the observed 0.5–2 keV band, finding a decline in the number of sources at z > 3 and constraining phenomenological models of the X-ray background. We compute the AGN space density at z > 3 in two different luminosity bins. At higher luminosities (log L (2–10 keV) > 44.1 erg s{sup −1}), the space density declines exponentially, dropping by a factor of ∼20 from z ∼ 3 to z ∼ 6. The observed decline is ∼80% steeper at lower luminosities (43.55 erg s{sup −1} < logL(2–10 keV) < 44.1 erg s{sup −1}) from z ∼ 3 to z ∼ 4.5. We study the space density evolution dividing our sample into optically classified Type 1 and Type 2 AGNs. At log L (2–10 keV) > 44.1 erg s{sup −1}, unobscured and obscured objects may have different evolution with redshift, with the obscured component being three times higher at z ∼ 5. Finally, we compare our space density with predictions of quasar activation merger models, whose calibration is based on optically luminous AGNs. These models significantly overpredict the number of expected AGNs at log L (2–10 keV) > 44.1 erg s{sup −1} with respect to our data.

  14. (Almost) Dark Galaxies in the ALFALFA Survey: HI-bearing Ultra-Diffuse Galaxies, and Beyond

    Science.gov (United States)

    Leisman, Luke; Haynes, Martha P.; Giovanelli, Riccardo; ALFALFA Almost Darks Team

    2017-01-01

    Scaling relations between HI and stars in galaxies suggest strong ties between their atomic gas content and star formation laws. The Arecibo Legacy Fast ALFA (ALFALFA) blind extragalactic HI survey is well positioned to locate very low surface brightness sources that lie off these relations, the most extreme of which may fall below optical detection limits. Thus, the ALFALFA (Almost) Darks Project has been investigating extreme outliers from these relations by studying the ~1% of ALFALFA sources without apparent stellar counterparts in major optical surveys. We have obtained deep HI and optical imaging of 25 of these candidate "dark" sources. We find that most "dark" sources are not extreme "(almost) dark" galaxies. A few are rare OH Megamasers, redshifted into the ALFALFA bandpass, and many are part of large galactic plumes, stretching as far as 600 kpc from their host galaxy. However, a small handful of sources appear to be galaxies with extreme stellar systems. We find multiple systems with HI mass to stellar mass ratios an order of magnitude larger than typical gas rich dwarfs. Further, we find an isolated population of HI-bearing "ultra diffuse" galaxies (UDGs), with stellar masses of dwarfs, but HI and optical radii of L* galaxies. We suggest that these sources may be related to recently reported gas poor, quiescent UDGs.

  15. SONS: The JCMT legacy survey of debris discs in the submillimetre

    OpenAIRE

    Holland, Wayne S.; Matthews, Brenda C.; Kennedy, Grant M.; Greaves, Jane S.; Wyatt, Mark C.; Booth, Mark; Bastien, Pierre; Bryden, Geoff; Butner, Harold; Chen, Christine H.; Chrysostomou, Antonio; Davies, Claire L.; Dent, William R. F.; Di Francesco, James; Duchene, Gaspard

    2017-01-01

    Debris discs are evidence of the ongoing destructive collisions between planetesimals, and their presence around stars also suggests that planets exist in these systems. In this paper, we present submillimetre images of the thermal emission from debris discs that formed the SCUBA-2 Observations of Nearby Stars (SONS) survey, one of seven legacy surveys undertaken on the James Clerk Maxwell Telescope between 2012 and 2015. The overall results of the survey are presented in the form of 850 μm (...

  16. CANDELS : THE COSMIC ASSEMBLY NEAR-INFRARED DEEP EXTRAGALACTIC LEGACY SURVEY

    NARCIS (Netherlands)

    Grogin, Norman A.; Kocevski, Dale D.; Faber, S. M.; Ferguson, Henry C.; Koekemoer, Anton M.; Riess, Adam G.; Acquaviva, Viviana; Alexander, David M.; Almaini, Omar; Ashby, Matthew L. N.; Barden, Marco; Bell, Eric F.; Bournaud, Frederic; Brown, Thomas M.; Caputi, Karina I.; Casertano, Stefano; Cassata, Paolo; Castellano, Marco; Challis, Peter; Chary, Ranga-Ram; Cheung, Edmond; Cirasuolo, Michele; Conselice, Christopher J.; Cooray, Asantha Roshan; Croton, Darren J.; Daddi, Emanuele; Dahlen, Tomas; Dave, Romeel; de Mello, Duilia F.; Dekel, Avishai; Dickinson, Mark; Dolch, Timothy; Donley, Jennifer L.; Dunlop, James S.; Dutton, Aaron A.; Elbaz, David; Fazio, Giovanni G.; Filippenko, Alexei V.; Finkelstein, Steven L.; Fontana, Adriano; Gardner, Jonathan P.; Garnavich, Peter M.; Gawiser, Eric; Giavalisco, Mauro; Grazian, Andrea; Guo, Yicheng; Hathi, Nimish P.; Haeussler, Boris; Hopkins, Philip F.; Huang, Jia-Sheng; Huang, Kuang-Han; Jha, Saurabh W.; Kartaltepe, Jeyhan S.; Kirshner, Robert P.; Koo, David C.; Lai, Kamson; Lee, Kyoung-Soo; Li, Weidong; Lotz, Jennifer M.; Lucas, Ray A.; Madau, Piero; McCarthy, Patrick J.; McGrath, Elizabeth J.; McIntosh, Daniel H.; McLure, Ross J.; Mobasher, Bahram; Moustakas, Leonidas A.; Mozena, Mark; Nandra, Kirpal; Newman, Jeffrey A.; Niemi, Sami-Matias; Noeske, Kai G.; Papovich, Casey J.; Pentericci, Laura; Pope, Alexandra; Primack, Joel R.; Rajan, Abhijith; Ravindranath, Swara; Reddy, Naveen A.; Renzini, Alvio; Rix, Hans-Walter; Robaina, Aday R.; Rodney, Steven A.; Rosario, David J.; Rosati, Piero; Salimbeni, Sara; Scarlata, Claudia; Siana, Brian; Simard, Luc; Smidt, Joseph; Somerville, Rachel S.; Spinrad, Hyron; Straughn, Amber N.; Strolger, Louis-Gregory; Telford, Olivia; Teplitz, Harry I.; Trump, Jonathan R.; van der Wel, Arjen; Villforth, Carolin; Wechsler, Risa H.; Weiner, Benjamin J.; Wiklind, Tommy; Wild, Vivienne; Wilson, Grant; Wuyts, Stijn; Yan, Hao-Jing; Yun, Min S.

    2011-01-01

    The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) is designed to document the first third of galactic evolution, over the approximate redshift (z) range 8-1.5. It will image >250,000 distant galaxies using three separate cameras on the Hubble Space Telescope, from the

  17. CALIFA, the Calar Alto Legacy Integral Field Area survey. III. Second public data release

    NARCIS (Netherlands)

    García-Benito, R.; Zibetti, S.; Sánchez, S. F.; Husemann, B.; de Amorim, A. L.; Castillo-Morales, A.; Cid Fernandes, R.; Ellis, S. C.; Falcón-Barroso, J.; Galbany, L.; Gil de Paz, A.; González Delgado, R. M.; Lacerda, E. A. D.; López-Fernandez, R.; de Lorenzo-Cáceres, A.; Lyubenova, M.; Marino, R. A.; Mast, D.; Mendoza, M. A.; Pérez, E.; Vale Asari, N.; Aguerri, J. A. L.; Ascasibar, Y.; Bekerait*error*ė, S.; Bland-Hawthorn, J.; Barrera-Ballesteros, J. K.; Bomans, D. J.; Cano-Díaz, M.; Catalán-Torrecilla, C.; Cortijo, C.; Delgado-Inglada, G.; Demleitner, M.; Dettmar, R.-J.; Díaz, A. I.; Florido, E.; Gallazzi, A.; García-Lorenzo, B.; Gomes, J. M.; Holmes, L.; Iglesias-Páramo, J.; Jahnke, K.; Kalinova, V.; Kehrig, C.; Kennicutt, R. C.; López-Sánchez, Á. R.; Márquez, I.; Masegosa, J.; Meidt, S. E.; Mendez-Abreu, J.; Mollá, M.; Monreal-Ibero, A.; Morisset, C.; del Olmo, A.; Papaderos, P.; Pérez, I.; Quirrenbach, A.; Rosales-Ortega, F. F.; Roth, M. M.; Ruiz-Lara, T.; Sánchez-Blázquez, P.; Sánchez-Menguiano, L.; Singh, R.; Spekkens, K.; Stanishev, V.; Torres-Papaqui, J. P.; van de Ven, G.; Vilchez, J. M.; Walcher, C. J.; Wild, V.; Wisotzki, L.; Ziegler, B.; Alves, J.; Barrado, D.; Quintana, J. M.; Aceituno, J.

    This paper describes the Second Public Data Release (DR2) of the Calar Alto Legacy Integral Field Area (CALIFA) survey. The data for 200 objects are made public, including the 100 galaxies of the First Public Data Release (DR1). Data were obtained with the integral-field spectrograph PMAS/PPak

  18. CALIFA, the Calar Alto Legacy Integral Field Area survey : II. First public data release

    NARCIS (Netherlands)

    Husemann, B.; Jahnke, K.; Sanchez, S. F.; Barrado, D.; Bekeraite, S.; Bomans, D. J.; Castillo-Morales, A.; Catalan-Torrecilla, C.; Cid Fernandes, R.; Falcon-Barroso, J.; Garcia-Benito, R.; Gonzalez Delgado, R. M.; Iglesias-Paramo, J.; Johnson, B. D.; Kupko, D.; Lopez-Fernandez, R.; Lyubenova, M.; Marino, R. A.; Mast, D.; Miskolczi, A.; Monreal-Ibero, A.; Gil de Paz, A.; Perez, E.; Perez, I.; Rosales-Ortega, F. F.; Ruiz-Lara, T.; Schilling, U.; van de Ven, G.; Walcher, J.; Alves, J.; de Amorim, A. L.; Backsmann, N.; Barrera-Ballesteros, J. K.; Bland-Hawthorn, J.; Cortijo, C.; Dettmar, R. -J.; Demleitner, M.; Diaz, A. I.; Enke, H.; Florido, E.; Flores, H.; Galbany, L.; Gallazzi, A.; Garcia-Lorenzo, B.; Gomes, J. M.; Gruel, N.; Haines, T.; Holmes, L.; Jungwiert, B.; Kalinova, V.; Kehrig, C.; Kennicutt, R. C.; Klar, J.; Lehnert, M. D.; Lopez-Sanchez, A. R.; de Lorenzo-Caceres, A.; Marmol-Queralto, E.; Marquez, I.; Mendez-Abreu, J.; Molla, M.; del Olmo, A.; Meidt, S. E.; Papaderos, P.; Puschnig, J.; Quirrenbach, A.; Roth, M. M.; Sanchez-Blazquez, P.; Spekkens, K.; Singh, R.; Stanishev, V.; Trager, S. C.; Vilchez, J. M.; Wild, V.; Wisotzki, L.; Zibetti, S.; Ziegler, B.

    We present the first public data release (DR1) of the Calar Alto Legacy Integral Field Area (CALIFA) survey. It consists of science-grade optical datacubes for the first 100 of eventually 600 nearby (0.005

  19. CALIFA, the Calar Alto Legacy Integral Field Area survey. II. First public data release

    NARCIS (Netherlands)

    Husemann, B.; Jahnke, K.; Sánchez, S. F.; Barrado, D.; Bekerait*error*ė, S.; Bomans, D. J.; Castillo-Morales, A.; Catalán-Torrecilla, C.; Cid Fernandes, R.; Falcón-Barroso, J.; García-Benito, R.; González Delgado, R. M.; Iglesias-Páramo, J.; Johnson, B. D.; Kupko, D.; López-Fernandez, R.; Lyubenova, M.; Marino, R. A.; Mast, D.; Miskolczi, A.; Monreal-Ibero, A.; Gil de Paz, A.; Pérez, E.; Pérez, I.; Rosales-Ortega, F. F.; Ruiz-Lara, T.; Schilling, U.; van de Ven, G.; Walcher, J.; Alves, J.; de Amorim, A. L.; Backsmann, N.; Barrera-Ballesteros, J. K.; Bland-Hawthorn, J.; Cortijo, C.; Dettmar, R.-J.; Demleitner, M.; Díaz, A. I.; Enke, H.; Florido, E.; Flores, H.; Galbany, L.; Gallazzi, A.; García-Lorenzo, B.; Gomes, J. M.; Gruel, N.; Haines, T.; Holmes, L.; Jungwiert, B.; Kalinova, V.; Kehrig, C.; Kennicutt, R. C.; Klar, J.; Lehnert, M. D.; López-Sánchez, Á. R.; de Lorenzo-Cáceres, A.; Mármol-Queraltó, E.; Márquez, I.; Mendez-Abreu, J.; Mollá, M.; del Olmo, A.; Meidt, S. E.; Papaderos, P.; Puschnig, J.; Quirrenbach, A.; Roth, M. M.; Sánchez-Blázquez, P.; Spekkens, K.; Singh, R.; Stanishev, V.; Trager, S. C.; Vilchez, J. M.; Wild, V.; Wisotzki, L.; Zibetti, S.; Ziegler, B.

    We present the first public data release (DR1) of the Calar Alto Legacy Integral Field Area (CALIFA) survey. It consists of science-grade optical datacubes for the first 100 of eventually 600 nearby (0.005

  20. Status of the Dark Energy Survey Camera (DECam) Project

    Energy Technology Data Exchange (ETDEWEB)

    Flaugher, Brenna L.; Abbott, Timothy M.C.; Angstadt, Robert; Annis, Jim; Antonik, Michelle, L.; Bailey, Jim; Ballester, Otger.; Bernstein, Joseph P.; Bernstein, Rebbeca; Bonati, Marco; Bremer, Gale; /Fermilab /Cerro-Tololo InterAmerican Obs. /ANL /Texas A-M /Michigan U. /Illinois U., Urbana /Ohio State U. /University Coll. London /LBNL /SLAC /IFAE

    2012-06-29

    The Dark Energy Survey Collaboration has completed construction of the Dark Energy Camera (DECam), a 3 square degree, 570 Megapixel CCD camera which will be mounted on the Blanco 4-meter telescope at CTIO. DECam will be used to perform the 5000 sq. deg. Dark Energy Survey with 30% of the telescope time over a 5 year period. During the remainder of the time, and after the survey, DECam will be available as a community instrument. All components of DECam have been shipped to Chile and post-shipping checkout finished in Jan. 2012. Installation is in progress. A summary of lessons learned and an update of the performance of DECam and the status of the DECam installation and commissioning will be presented.

  1. Status of the Dark Energy Survey Camera (DECam) project

    Energy Technology Data Exchange (ETDEWEB)

    Flaugher, Brenna L.; McLean, Ian S.; Ramsay, Suzanne K.; Abbott, Timothy M. C.; Angstadt, Robert; Takami, Hideki; Annis, Jim; Antonik, Michelle L.; Bailey, Jim; Ballester, Otger; Bernstein, Joseph P.; Bernstein, Rebecca A.; Bonati, Marco; Bremer, Gale; Briones, Jorge; Brooks, David; Buckley-Geer, Elizabeth J.; Campa, Juila; Cardiel-Sas, Laia; Castander, Francisco; Castilla, Javier; Cease, Herman; Chappa, Steve; Chi, Edward C.; da Costa, Luis; DePoy, Darren L.; Derylo, Gregory; de Vincente, Juan; Diehl, H. Thomas; Doel, Peter; Estrada, Juan; Eiting, Jacob; Elliott, Anne E.; Finley, David A.; Flores, Rolando; Frieman, Josh; Gaztanaga, Enrique; Gerdes, David; Gladders, Mike; Guarino, V.; Gutierrez, G.; Grudzinski, Jim; Hanlon, Bill; Hao, Jiangang; Holland, Steve; Honscheid, Klaus; Huffman, Dave; Jackson, Cheryl; Jonas, Michelle; Karliner, Inga; Kau, Daekwang; Kent, Steve; Kozlovsky, Mark; Krempetz, Kurt; Krider, John; Kubik, Donna; Kuehn, Kyler; Kuhlmann, Steve E.; Kuk, Kevin; Lahav, Ofer; Langellier, Nick; Lathrop, Andrew; Lewis, Peter M.; Lin, Huan; Lorenzon, Wolfgang; Martinez, Gustavo; McKay, Timothy; Merritt, Wyatt; Meyer, Mark; Miquel, Ramon; Morgan, Jim; Moore, Peter; Moore, Todd; Neilsen, Eric; Nord, Brian; Ogando, Ricardo; Olson, Jamieson; Patton, Kenneth; Peoples, John; Plazas, Andres; Qian, Tao; Roe, Natalie; Roodman, Aaron; Rossetto, B.; Sanchez, E.; Soares-Santos, Marcelle; Scarpine, Vic; Schalk, Terry; Schindler, Rafe; Schmidt, Ricardo; Schmitt, Richard; Schubnell, Mike; Schultz, Kenneth; Selen, M.; Serrano, Santiago; Shaw, Terri; Simaitis, Vaidas; Slaughter, Jean; Smith, R. Christopher; Spinka, Hal; Stefanik, Andy; Stuermer, Walter; Sypniewski, Adam; Talaga, R.; Tarle, Greg; Thaler, Jon; Tucker, Doug; Walker, Alistair R.; Weaverdyck, Curtis; Wester, William; Woods, Robert J.; Worswick, Sue; Zhao, Allen

    2012-09-24

    The Dark Energy Survey Collaboration has completed construction of the Dark Energy Camera (DECam), a 3 square degree, 570 Megapixel CCD camera which will be mounted on the Blanco 4-meter telescope at CTIO. DECam will be used to perform the 5000 sq. deg. Dark Energy Survey with 30% of the telescope time over a 5 year period. During the remainder of the time, and after the survey, DECam will be available as a community instrument. All components of DECam have been shipped to Chile and post-shipping checkout finished in Jan. 2012. Installation is in progress. A summary of lessons learned and an update of the performance of DECam and the status of the DECam installation and commissioning will be presented.

  2. The VLT/X-shooter GRB afterglow legacy survey

    Science.gov (United States)

    Kaper, Lex; Fynbo, Johan P. U.; Pugliese, Vanna; van Rest, Daan

    2017-11-01

    The Swift satellite allows us to use gamma-ray bursts (GRBs) to peer through the hearts of star forming galaxies through cosmic time. Our open collaboration, representing most of the active European researchers in this field, builds a public legacy sample of GRB X-shooter spectroscopy while Swift continues to fly. To date, our spectroscopy of more than 100 GRB afterglows covers a redshift range from 0.059 to about 8 (Tanvir et al. 2009, Nature 461, 1254), with more than 20 robust afterglow-based metallicity measurements (over a redshift range from 1.7 to 5.9). With afterglow spectroscopy (throughout the electromagnetic spectrum from X-rays to the sub-mm) we can hence characterize the properties of star-forming galaxies over cosmic history in terms of redshift, metallicity, molecular content, ISM temperature, UV-flux density, etc.. These observations provide key information on the final evolution of the most massive stars collapsing into black holes, with the potential of probing the epoch of the formation of the first (very massive) stars. VLT/X-shooter (Vernet et al. 2011, A&A 536, A105) is in many ways the ideal GRB follow-up instrument and indeed GRB follow-up was one of the primary science cases behind the instrument design and implementation. Due to the wide wavelength coverage of X-shooter, in the same observation one can detect molecular H2 absorption near the atmospheric cut-off and many strong emission lines from the host galaxy in the near-infrared (e.g., Friis et al. 2015, MNRAS 451, 167). For example, we have measured a metallicity of 0.1 Z ⊙ for GRB 100219A at z = 4.67 (Thöne et al. 2013, MNRAS 428, 3590), 0.02 Z ⊙ for GRB 111008A at z = 4.99 (Sparre et al. 2014, ApJ 785, 150) and 0.05 Z ⊙ for GRB 130606A at z = 5.91 (Hartoog et al. 2015, A&A 580, 139). In the latter, the very high value of [Al/Fe]=2.40 +/- 0.78 might be due to a proton capture process and may be a signature of a previous generation of massive (perhaps even the first) stars

  3. First SN Discoveries from the Dark Energy Survey

    Science.gov (United States)

    Abbott, T.; Abdalla, F.; Achitouv, I.; Ahn, E.; Aldering, G.; Allam, S.; Alonso, D.; Amara, A.; Annis, J.; Antonik, M.; Aragon-Salamanca, A.; Armstrong, R.; Ashall, C.; Asorey, J.; Bacon, D.; Balbinot, E.; Banerji, M.; Barbary, K.; Barkhouse, W.; Baruah, L.; Bauer, A.; Bechtol, K.; Becker, M.; Bender, R.; Benoist, C.; Benoit-Levy, A.; Bernardi, M.; Bernstein, G.; Bernstein, J. P.; Bernstein, R.; Bertin, E.; Beynon, E.; Bhattacharya, S.; Biesiadzinski, T.; Biswas, R.; Blake, C.; Bloom, J. S.; Bocquet, S.; Brandt, C.; Bridle, S.; Brooks, D.; Brown, P. J.; Brunner, R.; Buckley-Geer, E.; Burke, D.; Burkert, A.; Busha, M.; Campa, J.; Campbell, H.; Cane, R.; Capozzi, D.; Carlstrom, J.; Carnero Rosell, A.; Carollo, M.; Carrasco-Kind, M.; Carretero, J.; Carter, M.; Casas, R.; Castander, F. J.; Chen, Y.; Chiu, I.; Chue, C.; Clampitt, J.; Clerkin, L.; Cohn, J.; Colless, M.; Copeland, E.; Covarrubias, R. A.; Crittenden, R.; Crocce, M.; Cunha, C.; da Costa, L.; d'Andrea, C.; Das, S.; Das, R.; Davis, T. M.; Deb, S.; DePoy, D.; Derylo, G.; Desai, S.; de Simoni, F.; Devlin, M.; Diehl, H. T.; Dietrich, J.; Dodelson, S.; Doel, P.; Dolag, K.; Efstathiou, G.; Eifler, T.; Erickson, B.; Eriksen, M.; Estrada, J.; Etherington, J.; Evrard, A.; Farrens, S.; Fausti Neto, A.; Fernandez, E.; Ferreira, P. C.; Finley, D.; Fischer, J. A.; Flaugher, B.; Fosalba, P.; Frieman, J.; Furlanetto, C.; Garcia-Bellido, J.; Gaztanaga, E.; Gelman, M.; Gerdes, D.; Giannantonio, T.; Gilhool, S.; Gill, M.; Gladders, M.; Gladney, L.; Glazebrook, K.; Gray, M.; Gruen, D.; Gruendl, R.; Gupta, R.; Gutierrez, G.; Habib, S.; Hall, E.; Hansen, S.; Hao, J.; Heitmann, K.; Helsby, J.; Henderson, R.; Hennig, C.; High, W.; Hirsch, M.; Hoffmann, K.; Holhjem, K.; Honscheid, K.; Host, O.; Hoyle, B.; Hu, W.; Huff, E.; Huterer, D.; Jain, B.; James, D.; Jarvis, M.; Jarvis, M. J.; Jeltema, T.; Johnson, M.; Jouvel, S.; Kacprzak, T.; Karliner, I.; Katsaros, J.; Kent, S.; Kessler, R.; Kim, A.; Kim-Vy, T.; King, L.; Kirk, D.; Kochanek, C.; Kopp, M.; Koppenhoefer, J.; Kovacs, E.; Krause, E.; Kravtsov, A.; Kron, R.; Kuehn, K.; Kuemmel, M.; Kuhlmann, S.; Kunder, A.; Kuropatkin, N.; Kwan, J.; Lahav, O.; Leistedt, B.; Levi, M.; Lewis, P.; Liddle, A.; Lidman, C.; Lilly, S.; Lin, H.; Liu, J.; Lopez-Arenillas, C.; Lorenzon, W.; LoVerde, M.; Ma, Z.; Maartens, R.; Maccrann, N.; Macri, L.; Maia, M.; Makler, M.; Manera, M.; Maraston, C.; March, M.; Markovic, K.; Marriner, J.; Marshall, J.; Marshall, S.; Martini, P.; Marti Sanahuja, P.; Mayers, J.; McKay, T.; McMahon, R.; Melchior, P.; Merritt, K. W.; Merson, A.; Miller, C.; Miquel, R.; Mohr, J.; Moore, T.; Mortonson, M.; Mosher, J.; Mould, J.; Mukherjee, P.; Neilsen, E.; Ngeow, C.; Nichol, R.; Nidever, D.; Nord, B.; Nugent, P.; Ogando, R.; Old, L.; Olsen, J.; Ostrovski, F.; Paech, K.; Papadopoulos, A.; Papovich, C.; Patton, K.; Peacock, J.; Pellegrini, P. S. S.; Peoples, J.; Percival, W.; Perlmutter, S.; Petravick, D.; Plazas, A.; Ponce, R.; Poole, G.; Pope, A.; Refregier, A.; Reyes, R.; Ricker, P.; Roe, N.; Romer, K.; Roodman, A.; Rooney, P.; Ross, A.; Rowe, B.; Rozo, E.; Rykoff, E.; Sabiu, C.; Saglia, R.; Sako, M.; Sanchez, A.; Sanchez, C.; Sanchez, E.; Sanchez, J.; Santiago, B.; Saro, A.; Scarpine, V.; Schindler, R.; Schmidt, B. P.; Schmitt, R. L.; Schubnell, M.; Seitz, S.; Senger, R.; Sevilla, I.; Sharp, R.; Sheldon, E.; Sheth, R.; Smith, R. C.; Smith, M.; Snigula, J.; Soares-Santos, M.; Sobreira, F.; Song, J.; Soumagnac, M.; Spinka, H.; Stebbins, A.; Stoughton, C.; Suchyta, E.; Suhada, R.; Sullivan, M.; Sun, F.; Suntzeff, N.; Sutherland, W.; Swanson, M. E. C.; Sypniewski, A. J.; Szepietowski, R.; Talaga, R.; Tarle, G.; Tarrant, E.; Balan, S. Thaithara; Thaler, J.; Thomas, D.; Thomas, R. C.; Tucker, D.; Uddin, S. A.; Ural, S.; Vikram, V.; Voigt, L.; Walker, A. R.; Walker, T.; Wechsler, R.; Weinberg, D.; Weller, J.; Wester, W.; Wetzstein, M.; White, M.; Wilcox, H.; Wilman, D.; Yanny, B.; Young, J.; Zablocki, A.; Zenteno, A.; Zhang, Y.; Zuntz, J.

    2012-12-01

    The Dark Energy Survey (DES) report the discovery of the first set of supernovae (SN) from the project. Images were observed as part of the DES Science Verification phase using the newly-installed 570-Megapixel Dark Energy Camera on the CTIO Blanco 4-m telescope by observers J. Annis, E. Buckley-Geer, and H. Lin. SN observations are planned throughout the observing campaign on a regular cadence of 4-6 days in each of the ten 3-deg2 fields in the DES griz filters.

  4. CALIFA, the Calar Alto Legacy Integral Field Area survey

    Czech Academy of Sciences Publication Activity Database

    Husemann, B.; Jahnke, K.; Sánchez, Sebastián F.; Barrado, D.; Bekeraite, S.; Bomans, D.J.; Castillo-Morales, A.; Catalán-Torrecilla, C.; Fernandes, R.C.; Jungwiert, Bruno

    2013-01-01

    Roč. 549, January (2013), A87/1-A87/25 ISSN 0004-6361 Grant - others:Rada Programu interní podpory projektů mezinárodní spolupráce AV ČR(CZ) M100031201 Program:M Institutional support: RVO:67985815 Keywords : spectroscopic techniques * galaxy * surveys Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.479, year: 2013

  5. First Discoveries of z > 6 Quasars with the DECam Legacy Survey and UKIRT Hemisphere Survey

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Feige; Yang, Jinyi; Wu, Xue-Bing; Yang, Qian; Li, Zefeng [Department of Astronomy, School of Physics, Peking University, Beijing 100871 (China); Fan, Xiaohui; McGreer, Ian D.; Ding, Jiani; Green, Richard [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Bian, Fuyan [Research School of Astronomy and Astrophysics, Australian National University, Weston Creek, ACT 2611 (Australia); Li, Jiang-Tao [Department of Astronomy, University of Michigan, 311 West Hall, 1085 S. University Avenue, Ann Arbor, MI, 48109 (United States); Dey, Arjun [National Optical Astronomy Observatory, 950 N. Cherry Avenue, Tucson, AZ 85719 (United States); Dye, Simon [School of Physics and Astronomy, Nottingham University, University Park, Nottingham, NG7 2RD (United Kingdom); Findlay, Joseph R.; Myers, Adam D. [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States); James, David [Cerro Tololo Inter-American Observatory, Casilla 603 La Serena (Chile); Jiang, Linhua [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China); Lang, Dustin [Dunlap Institute for Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, Ontario, M5S 3H4 (Canada); Lawrence, Andy; Ross, Nicholas P. [Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh, EH9 3HJ (United Kingdom); and others

    2017-04-10

    We present the first discoveries from a survey of z ≳ 6 quasars using imaging data from the DECam Legacy Survey (DECaLS) in the optical, the UKIRT Deep Infrared Sky Survey (UKIDSS) and a preliminary version of the UKIRT Hemisphere Survey (UHS) in the near-IR, and ALLWISE in the mid-IR. DECaLS will image 9000 deg{sup 2} of sky down to z {sub AB} ∼ 23.0, and UKIDSS and UHS will map the northern sky at 0 < decl. < +60°, reaching J {sub VEGA} ∼ 19.6 (5- σ ). The combination of these data sets allows us to discover quasars at redshift z ≳ 7 and to conduct a complete census of the faint quasar population at z ≳ 6. In this paper, we report on the selection method of our search, and on the initial discoveries of two new, faint z ≳ 6 quasars and one new z = 6.63 quasar in our pilot spectroscopic observations. The two new z ∼ 6 quasars are at z = 6.07 and z = 6.17 with absolute magnitudes at rest-frame wavelength 1450 Å being M {sub 1450} = −25.83 and M {sub 1450} = −25.76, respectively. These discoveries suggest that we can find quasars close to or fainter than the break magnitude of the Quasar Luminosity Function (QLF) at z ≳ 6. The new z = 6.63 quasar has an absolute magnitude of M {sub 1450} = −25.95. This demonstrates the potential of using the combined DECaLS and UKIDSS/UHS data sets to find z ≳ 7 quasars. Extrapolating from previous QLF measurements, we predict that these combined data sets will yield ∼200 z ∼ 6 quasars to z {sub AB} < 21.5, ∼1000 z ∼ 6 quasars to z {sub AB} < 23, and ∼30 quasars at z > 6.5 to J {sub VEGA} < 19.5.

  6. Nobeyama 45 m telescope legacy project: Line survey

    Science.gov (United States)

    Takano, S.; Aikawa, Y.; Chen, V.; Hirano, N.; Hiramatsu, M.; Hirota, T.; Kamegai, K.; Kobayashi, K.; Kohno, K.; Kuan, Y. J.; Liu, S. Y.; Nakajima, T.; Nomura, H.; Ohashi, N.; Ohishi, M.; Ozeki, H.; Sakai, N.; Sakai, T.; Shiba, S.; Su, Y. N.; Sugimura, M.; Takakuwa, S.; Umemoto, T.; Wang, K.; Yamada, M.; Yamaguchi, T.; Yamamoto, S.; Zhang, Q. Z.

    2011-05-01

    We started line survey observations toward a few interesting sources with the Nobeyama 45 m telescope. The target sources include L1527, L1157 (B1), G28.34+0.06, NGC 1068, and NGC 253. Mainly with the new 3 mm receivers installed on the 45 m telescope [1], the frequency range of ~84-115 GHz will be surveyed with high sensitivity. The third year of the surveys was finished, and the fourth year observations are in progress. L1527 is a very interesting object, because the abundances of carbon-chain molecules are high, though this source is a low-mass star-forming region [2]. We detected many lines including high excitation lines of HC5N (e.g. J=41-40, Eupper of 110 K), isotopic species (D, 13C) of some carbon-chain and carbon-ring molecules, HCO, C3O, cyclic-C3H, etc. In L1157 B1 position, where interactions between an outflow and ambient clouds are prominent [3,4], we detected many lines including C2H, C34S, CCS, HCNO, CH3CN, CH2DOH, CH3CHO, HCOOCH3, and NH2CHO. To study shock chemistry and gas-grain interaction, these results are rather important information [5]. After our observations, we noticed that HCOOCH3 was detected by Arce et al. [6]. In G28.34+0.06 three interesting positions called mm1, mm4, and mm9 are selected. Toward mm1 and mm4 line wings were found in HCO+, HCN, SiO, CS, and CH3OH. These wings indicate outflow activities. In addition, one of the grain related species, CH3CHO, is detected only in mm1 and mm4. Based on these results, mm1 and mm4 are thought to be high-mass protostellar objects. Data of deuterated species, DNC, DCO+, and N2D+, also support this view. About galaxies we are mainly observing NGC 1068, which is a nearby galaxy with Active Galactic Nucleus (AGN). Our motivation is to study the effect of AGN on molecular abundances (cf. [7]). In addition a prototypical starburst galaxy NGC 253 is observed. We detected C2H (N=1-0), H13CN (J=1-0), and cyclic-C3H2 in NGC 1068 [8]: No significant differences in the abundances of C2H and cyclic-C3H

  7. THE CANADA-FRANCE-HAWAII TELESCOPE LEGACY SURVEY: STACKED IMAGES AND CATALOGS

    International Nuclear Information System (INIS)

    Gwyn, Stephen D. J.

    2012-01-01

    This paper describes the image stacks and catalogs of the Canada-France-Hawaii Telescope Legacy Survey produced using the MegaPipe data pipeline at the Canadian Astronomy Data Centre. The Legacy Survey is divided into two parts. The Deep Survey consists of four fields each of 1 deg 2 , with magnitude limits (50% completeness for point sources) of u = 27.5, g = 27.9, r = 27.7, i = 27.4, and z = 26.2. It contains 1.6 × 10 6 sources. The Wide Survey consists of 150 deg 2 split over four fields, with magnitude limits of u = 26.0, g = 26.5, r = 25.9, i = 25.7, and z = 24.6. It contains 3 × 10 7 sources. This paper describes the calibration, image stacking, and catalog generation process. The images and catalogs are available on the web through several interfaces: normal image and text file catalog downloads, a 'Google Sky' interface, an image cutout service, and a catalog database query service.

  8. The Dark Energy Survey: Prospects for resolved stellar populations

    Energy Technology Data Exchange (ETDEWEB)

    Rossetto, Bruno M. [Observatorio Nacional, Rio de Janeiro (Brazil); Lab. Interinstitucional de e-Astronomia-LIneA, Rio de Janeiro (Brazil); Santiago, Basílio X. [Lab. Interinstitucional de e-Astronomia-LIneA, Rio de Janeiro (Brazil); Instituto de Fisica, Porto Alegre (Brazil); Girardi, Léo [Lab. Interinstitucional de e-Astronomia-LIneA, Rio de Janeiro (Brazil); Osservatorio Astronomica di Padova-INAF, Padova (Italy); Camargo, Julio I. B. [Observatorio Nacional, Rio de Janeiro (Brazil); Lab. Interinstitucional de e-Astronomia-LIneA, Rio de Janeiro (Brazil); Balbinot, Eduardo [Lab. Interinstitucional de e-Astronomia-LIneA, Rio de Janeiro (Brazil); Instituto de Fisica, Porto Alegre (Brazil); da Costa, Luiz N. [Observatorio Nacional, Rio de Janeiro (Brazil); Lab. Interinstitucional de e-Astronomia-LIneA, Rio de Janeiro (Brazil); Yanny, Brian [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Maia, Marcio A. G. [Observatorio Nacional, Rio de Janeiro (Brazil); Lab. Interinstitucional de e-Astronomia-LIneA, Rio de Janeiro (Brazil); Makler, Martin [Lab. Interinstitucional de e-Astronomia-LIneA, Rio de Janeiro (Brazil); Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro (Brazil); Ogando, Ricardo L. C. [Observatorio Nacional, Rio de Janeiro (Brazil); Lab. Interinstitucional de e-Astronomia-LIneA, Rio de Janeiro (Brazil); Pellegrini, Paulo S. [Observatorio Nacional, Rio de Janeiro (Brazil); Lab. Interinstitucional de e-Astronomia-LIneA, Rio de Janeiro (Brazil); Ramos, Beatriz [Observatorio Nacional, Rio de Janeiro (Brazil); Lab. Interinstitucional de e-Astronomia-LIneA, Rio de Janeiro (Brazil); de Simoni, Fernando [Observatorio Nacional, Rio de Janeiro (Brazil); Lab. Interinstitucional de e-Astronomia-LIneA, Rio de Janeiro (Brazil); Armstrong, R. [Univ. of Illinois, Urbana, IL (United States); Bertin, E. [Univ. Pierre et Marie Curie, Paris (France); Desai, S. [Univ. of Illinois, Urbana, IL (United States); Kuropatkin, N. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Lin, H. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Mohr, J. J. [Max-Planck-Institut fur extraterrestrische Physik, Garching (Germany); Tucker, D. L. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2011-05-06

    Wide angle and deep surveys, regardless of their primary purpose, always sample a large number of stars in the Galaxy and in its satellite system. We here make a forecast of the expected stellar sample resulting from the Dark Energy Survey and the perspectives that it will open for studies of Galactic structure and resolved stellar populations in general. An estimated 1.2 x 108 stars will be sampled in DES grizY filters in the southern equatorial hemisphere. This roughly corresponds to 20% of all DES sources. Most of these stars belong to the stellar thick disk and halo of the Galaxy.

  9. The Dark Energy Survey and Operations: Years 1 to 3

    Energy Technology Data Exchange (ETDEWEB)

    Diehl, H. T. [Fermilab

    2016-01-01

    The Dark Energy Survey (DES) is an operating optical survey aimed at understanding the accelerating expansion of the universe using four complementary methods: weak gravitational lensing, galaxy cluster counts, baryon acoustic oscillations, and Type Ia supernovae. To perform the 5000 sq-degree wide field and 30 sq-degree supernova surveys, the DES Collaboration built the Dark Energy Camera (DECam), a 3 square-degree, 570-Megapixel CCD camera that was installed at the prime focus of the Blanco 4-meter telescope at the Cerro Tololo Inter-American Observatory (CTIO). DES has completed its third observing season out of a nominal five. This paper describes DES “Year 1” (Y1) to “Year 3” (Y3), the strategy, an outline of the survey operations procedures, the efficiency of operations and the causes of lost observing time. It provides details about the quality of the first three season's data, and describes how we are adjusting the survey strategy in the face of the El Niño Southern Oscillation

  10. System Architecture of the Dark Energy Survey Camera Readout Electronics

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, Theresa; /FERMILAB; Ballester, Otger; Cardiel-Sas, Laia; Castilla, Javier; /Barcelona, IFAE; Chappa, Steve; /Fermilab; de Vicente, Juan; /Madrid, CIEMAT; Holm, Scott; Huffman, Dave; Kozlovsky, Mark; /Fermilab; Martinez, Gustavo; /Madrid, CIEMAT; Moore, Todd; /Madrid, CIEMAT /Fermilab /Illinois U., Urbana /Fermilab

    2010-05-27

    The Dark Energy Survey makes use of a new camera, the Dark Energy Camera (DECam). DECam will be installed in the Blanco 4M telescope at Cerro Tololo Inter-American Observatory (CTIO). DECam is presently under construction and is expected to be ready for observations in the fall of 2011. The focal plane will make use of 62 2Kx4K and 12 2kx2k fully depleted Charge-Coupled Devices (CCDs) for guiding, alignment and focus. This paper will describe design considerations of the system; including, the entire signal path used to read out the CCDs, the development of a custom crate and backplane, the overall grounding scheme and early results of system tests.

  11. The Dark Energy Survey and operations: Year 1

    Science.gov (United States)

    Diehl, H. T.; Abbott, T. M. C.; Annis, J.; Armstrong, R.; Baruah, L.; Bermeo, A.; Bernstein, G.; Beynon, E.; Bruderer, C.; Buckley-Geer, E. J.; Campbell, H.; Capozzi, D.; Carter, M.; Casas, R.; Clerkin, L.; Covarrubias, R.; Cuhna, C.; D'Andrea, C.; da Costa, L.; Das, R.; DePoy, D. L.; Dietrich, J.; Drlica-Wagner, A.; Elliott, A.; Eifler, T.; Estrada, J.; Etherington, J.; Flaugher, B. L.; Frieman, J.; Fausti Neto, A.; Gelman, M.; Gerdes, D.; Gruen, D.; Gruendl, R.; Hao, J.; Head, H.; Helsby, J.; Hoffman, K.; Honscheid, K.; James, D.; Johnson, M.; Kacprzac, T.; Katsaros, J.; Kennedy, R.; Kent, S.; Kessler, R.; Kim, A.; Krause, E.; Kron, R.; Kuhlmann, S.; Kunder, A.; Li, T.; Lin, H.; Maccrann, N.; March, M.; Marshall, J.; Neilsen, E.; Nugent, P.; Martini, P.; Melchior, P.; Menanteau, F.; Nichol, R. C.; Nord, B.; Ogando, R.; Old, L.; Papadopoulos, A.; Patton, K.; Petravick, D.; Plazas, A. A.; Poulton, R.; Pujol, A.; Reil, K.; Rigby, T.; Romer, A.; Roodman, A.; Rooney, P.; Sanchez Alvaro, E.; Serrano, S.; Sheldon, E.; Smith, A.; Smith, R. C.; Soares-Santos, M.; Soumagnac, M.; Spinka, H.; Suchyta, E.; Tucker, D.; Walker, A. R.; Wester, W.; Wiesner, M.; Wilcox, H.; Williams, R.; Yanny, B.; Zhang, Y.-.

    2014-08-01

    The Dark Energy Survey (DES) is a next generation optical survey aimed at understanding the accelerating expansion of the universe using four complementary methods: weak gravitational lensing, galaxy cluster counts, baryon acoustic oscillations, and Type Ia supernovae. To perform the 5000 sq-degree wide field and 30 sq-degree supernova surveys, the DES Collaboration built the Dark Energy Camera (DECam), a 3 square-degree, 570-Megapixel CCD camera that was installed at the prime focus of the Blanco 4-meter telescope at the Cerro Tololo Inter-American Observatory (CTIO). DES started its first observing season on August 31, 2013 and observed for 105 nights through mid-February 2014. This paper describes DES "Year 1" (Y1), the strategy and goals for the first year's data, provides an outline of the operations procedures, lists the efficiency of survey operations and the causes of lost observing time, provides details about the quality of the first year's data, and hints at the "Year 2" plan and outlook.

  12. The James clerk maxwell telescope legacy survey of nearby star-forming regions in the gould belt

    NARCIS (Netherlands)

    Ward-Thompson, D.; Di Francesco, J.; Hatchell, J.; Hogerheijde, M. R.; Nutter, D.; Bastien, P.; Basu, S.; Bonnell, I.; Bowey, J.; Brunt, C.; Buckle, J.; Butner, H.; Cavanagh, B.; Chrysostomou, A.; Curtis, E.; Davis, C. J.; Dent, W. R. F.; van Dishoeck, E.; Edmunds, M. G.; Fich, M.; Fiege, J.; Fissel, L.; Friberg, P.; Friesen, R.; Frieswijk, W.; Fuller, G. A.; Gosling, A.; Graves, S.; Greaves, J. S.; Helmich, F.; Hills, R. E.; Holland, W. S.; Houde, M.; Jayawardhana, R.; Johnstone, D.; Joncas, G.; Kirk, H.; Kirk, J. M.; Knee, L. B. G.; Matthews, B.; Matthews, H.; Matzner, C.; Moriarty-Schieven, G. H.; Naylor, D.; Padman, R.; Plume, R.; Rawlings, J. M. C.; Redman, R. O.; Reid, M.; Richer, J. S.; Shipman, R.; Simpson, R. J.; Spaans, M.; Stamatellos, D.; Tsamis, Y. G.; Viti, S.; Weferling, B.; White, G. J.; Whitworth, A. P.; Wouterloot, J.; Yates, J.; Zhu, M.

    This paper describes a James Clerk Maxwell Telescope (JCMT) legacy survey that has been awarded roughly 500 hr of observing time to be carried out from 2007 to 2009. In this survey, we will map with SCUBA-2 (Submillimetre Common-User Bolometer Array 2) almost all of the well-known low-mass and

  13. Probing dark energy with lensing magnification in photometric surveys.

    Science.gov (United States)

    Schneider, Michael D

    2014-02-14

    I present an estimator for the angular cross correlation of two tracers of the cosmological large-scale structure that utilizes redshift information to isolate separate physical contributions. The estimator is derived by solving the Limber equation for a reweighting of the foreground tracer that nulls either clustering or lensing contributions to the cross correlation function. Applied to future photometric surveys, the estimator can enhance the measurement of gravitational lensing magnification effects to provide a competitive independent constraint on the dark energy equation of state.

  14. Clouds at CTIO and the Dark Energy Survey

    Energy Technology Data Exchange (ETDEWEB)

    Neilsen, Jr., Eric [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2015-08-01

    An understanding of the weather patters at Cerro-Tololo Inter-American (CTIO) Observatory, the observing site for the Dark Energy Survey (DES), is important for assessing the efciency of DES operations in using observing time and for planning future operations. CTIO has maintained records of cloud-cover by quarters of nights since 1975. A comparison between these cloud records in the 2013-2014 DES observing season (DES year 1) and achieved observing efciency and exposure quality allows the DES collaboration to make better use of the historical records in survey planning. Plots and tables here relate human recorded cloud-cover to collection of good DES data, show the variation of typical cloud-cover by month, and evaluate the relationship between the El Niño weather pattern and cloud-cover at CTIO.

  15. Stellar Streams Discovered in the Dark Energy Survey

    Energy Technology Data Exchange (ETDEWEB)

    Shipp, N.; et al.

    2018-01-09

    We perform a search for stellar streams around the Milky Way using the first three years of multi-band optical imaging data from the Dark Energy Survey (DES). We use DES data covering $\\sim 5000$ sq. deg. to a depth of $g > 23.5$ with a relative photometric calibration uncertainty of $< 1 \\%$. This data set yields unprecedented sensitivity to the stellar density field in the southern celestial hemisphere, enabling the detection of faint stellar streams to a heliocentric distance of $\\sim 50$ kpc. We search for stellar streams using a matched-filter in color-magnitude space derived from a synthetic isochrone of an old, metal-poor stellar population. Our detection technique recovers four previously known thin stellar streams: Phoenix, ATLAS, Tucana III, and a possible extension of Molonglo. In addition, we report the discovery of eleven new stellar streams. In general, the new streams detected by DES are fainter, more distant, and lower surface brightness than streams detected by similar techniques in previous photometric surveys. As a by-product of our stellar stream search, we find evidence for extra-tidal stellar structure associated with four globular clusters: NGC 288, NGC 1261, NGC 1851, and NGC 1904. The ever-growing sample of stellar streams will provide insight into the formation of the Galactic stellar halo, the Milky Way gravitational potential, as well as the large- and small-scale distribution of dark matter around the Milky Way.

  16. Observational Constraints on the Nature of the Dark Energy: First Cosmological Results From the ESSENCE Supernova Survey

    Energy Technology Data Exchange (ETDEWEB)

    Wood-Vasey, W.Michael; Miknaitis, G.; Stubbs, C.W.; Jha, S.; Riess, A.G.; Garnavich, P.M.; Kirshner, R.P.; Aguilera, C.; Becker, A.C.; Blackman, J.W.; Blondin, S.; Challis, P.; Clocchiatti, A.; Conley, A.; Covarrubias, R.; Davis, T.M.; Filippenko, A.V.; Foley, R.J.; Garg, A.; Hicken, M.; Krisciunas, K.; /Harvard-Smithsonian Ctr. Astrophys.

    2007-01-05

    We present constraints on the dark energy equation-of-state parameter, w = P/({rho}c{sup 2}), using 60 Type Ia supernovae (SNe Ia) from the ESSENCE supernova survey. We derive a set of constraints on the nature of the dark energy assuming a flat Universe. By including constraints on ({Omega}{sub M}, w) from baryon acoustic oscillations, we obtain a value for a static equation-of-state parameter w = -1.05{sub -0.12}{sup +0.13} (stat 1{sigma}) {+-} 0.13 (sys) and {Omega}{sub M} = 0.274{sub -0.020}{sup +0.033} (stat 1{sigma}) with a best-fit {chi}{sup 2}/DoF of 0.96. These results are consistent with those reported by the Super-Nova Legacy Survey in a similar program measuring supernova distances and redshifts. We evaluate sources of systematic error that afflict supernova observations and present Monte Carlo simulations that explore these effects. Currently, the largest systematic currently with the potential to affect our measurements is the treatment of extinction due to dust in the supernova host galaxies. Combining our set of ESSENCE SNe Ia with the SuperNova Legacy Survey SNe Ia, we obtain a joint constraint of w = -1.07{sub -0.09}{sup +0.09} (stat 1{sigma}) {+-} 0.13 (sys), {Omega}{sub M} = 0.267{sub -0.018}{sup +0.028} (stat 1{sigma}) with a best-fit {chi}{sup 2}/DoF of 0.91. The current SNe Ia data are fully consistent with a cosmological constant.

  17. CANDELS: THE COSMIC ASSEMBLY NEAR-INFRARED DEEP EXTRAGALACTIC LEGACY SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Grogin, Norman A.; Ferguson, Henry C.; Koekemoer, Anton M.; Brown, Thomas M.; Casertano, Stefano [Space Telescope Science Institute, Baltimore, MD (United States); Kocevski, Dale D.; Faber, S. M. [UCO/Lick Observatory, Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA (United States); Riess, Adam G. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD (United States); Acquaviva, Viviana [Department of Physics and Astronomy, Rutgers, State University of New Jersey, Piscataway, NJ (United States); Alexander, David M. [Department of Physics, Durham University, Durham (United Kingdom); Almaini, Omar [The School of Physics and Astronomy, University of Nottingham, Nottingham (United Kingdom); Ashby, Matthew L. N. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States); Barden, Marco [Institute of Astro- and Particle Physics, University of Innsbruck, Innsbruck (Austria); Bell, Eric F. [Department of Astronomy, University of Michigan, Ann Arbor, MI (United States); Bournaud, Frederic [CEA-Saclay/DSM/DAPNIA/Service d' Astrophysique, Gif-sur-Yvette (France); Caputi, Karina I. [Institute for Astronomy, University of Edinburgh, Edinburgh (United Kingdom); Cassata, Paolo [Department of Astronomy, University of Massachusetts, Amherst, MA (United States); Castellano, Marco [INAF, Osservatorio Astronomico di Roma, Rome (Italy); Challis, Peter [Harvard College Observatory, Cambridge, MA (United States); Chary, Ranga-Ram [U.S. Planck Data Center, California Institute of Technology, Pasadena, CA (United States); and others

    2011-12-01

    The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) is designed to document the first third of galactic evolution, over the approximate redshift (z) range 8-1.5. It will image >250,000 distant galaxies using three separate cameras on the Hubble Space Telescope, from the mid-ultraviolet to the near-infrared, and will find and measure Type Ia supernovae at z > 1.5 to test their accuracy as standardizable candles for cosmology. Five premier multi-wavelength sky regions are selected, each with extensive ancillary data. The use of five widely separated fields mitigates cosmic variance and yields statistically robust and complete samples of galaxies down to a stellar mass of 10{sup 9} M{sub Sun} to z Almost-Equal-To 2, reaching the knee of the ultraviolet luminosity function of galaxies to z Almost-Equal-To 8. The survey covers approximately 800 arcmin{sup 2} and is divided into two parts. The CANDELS/Deep survey (5{sigma} point-source limit H = 27.7 mag) covers {approx}125 arcmin{sup 2} within Great Observatories Origins Deep Survey (GOODS)-N and GOODS-S. The CANDELS/Wide survey includes GOODS and three additional fields (Extended Groth Strip, COSMOS, and Ultra-deep Survey) and covers the full area to a 5{sigma} point-source limit of H {approx}> 27.0 mag. Together with the Hubble Ultra Deep Fields, the strategy creates a three-tiered 'wedding-cake' approach that has proven efficient for extragalactic surveys. Data from the survey are nonproprietary and are useful for a wide variety of science investigations. In this paper, we describe the basic motivations for the survey, the CANDELS team science goals and the resulting observational requirements, the field selection and geometry, and the observing design. The Hubble data processing and products are described in a companion paper.

  18. AUTOMATED TRANSIENT IDENTIFICATION IN THE DARK ENERGY SURVEY

    International Nuclear Information System (INIS)

    Goldstein, D. A.; Nugent, P. E.; D’Andrea, C. B.; Nichol, R. C.; Papadopoulos, A.; Fischer, J. A.; Sako, M.; Wolf, R. C.; Foley, R. J.; Gupta, R. R.; Kessler, R.; Kim, A. G.; Thomas, R. C.; Smith, M.; Sullivan, M.; Wester, W.; Abdalla, F. B.; Benoit-Lévy, A.; Banerji, M.; Bertin, E.

    2015-01-01

    We describe an algorithm for identifying point-source transients and moving objects on reference-subtracted optical images containing artifacts of processing and instrumentation. The algorithm makes use of the supervised machine learning technique known as Random Forest. We present results from its use in the Dark Energy Survey Supernova program (DES-SN), where it was trained using a sample of 898,963 signal and background events generated by the transient detection pipeline. After reprocessing the data collected during the first DES-SN observing season (2013 September through 2014 February) using the algorithm, the number of transient candidates eligible for human scanning decreased by a factor of 13.4, while only 1.0% of the artificial Type Ia supernovae (SNe) injected into search images to monitor survey efficiency were lost, most of which were very faint events. Here we characterize the algorithm’s performance in detail, and we discuss how it can inform pipeline design decisions for future time-domain imaging surveys, such as the Large Synoptic Survey Telescope and the Zwicky Transient Facility. An implementation of the algorithm and the training data used in this paper are available at at http://portal.nersc.gov/project/dessn/autoscan

  19. Automated transient identification in the Dark Energy Survey

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, D. A. [Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). et al.

    2015-08-20

    We describe an algorithm for identifying point-source transients and moving objects on reference-subtracted optical images containing artifacts of processing and instrumentation. The algorithm makes use of the supervised machine learning technique known as Random Forest. We present results from its use in the Dark Energy Survey Supernova program (DES-SN), where it was trained using a sample of 898,963 signal and background events generated by the transient detection pipeline. After reprocessing the data collected during the first DES-SN observing season (2013 September through 2014 February) using the algorithm, the number of transient candidates eligible for human scanning decreased by a factor of 13.4, while only 1.0 percent of the artificial Type Ia supernovae (SNe) injected into search images to monitor survey efficiency were lost, most of which were very faint events. Here we characterize the algorithm's performance in detail, and we discuss how it can inform pipeline design decisions for future time-domain imaging surveys, such as the Large Synoptic Survey Telescope and the Zwicky Transient Facility.

  20. The Dark Energy Survey Data Processing and Calibration System

    Energy Technology Data Exchange (ETDEWEB)

    Mohr, Joseph J. [Munich U.; Armstrong, Robert [Penn State U.; Bertin, Emmanuel [Paris, Inst. Astrophys.; Daues, Gregory E. [NCSA, Urbana; Desai, Shantanu [Munich U.; Gower, Michelle [NCSA, Urbana; Gruendl, Robert [Illinois U., Urbana (main); Hanlon, William [Illinois U., Urbana (main); Kuropatkin, Nikolay [Fermilab; Lin, Huan [Fermilab; Marriner, John [Fermilab; Petravick, Don; Sevilla, Ignacio [Madrid, CIEMAT; Swanson, Molly [Harvard-Smithsonian Ctr. Astrophys.; Tomashek, Todd [NCSA, Urbana; Tucker, Douglas [Fermilab; Yanny, Brian [Fermilab

    2012-09-24

    The Dark Energy Survey (DES) is a 5000 deg2 grizY survey reaching characteristic photometric depths of 24th magnitude (10 sigma) and enabling accurate photometry and morphology of objects ten times fainter than in SDSS. Preparations for DES have included building a dedicated 3 deg2 CCD camera (DECam), upgrading the existing CTIO Blanco 4m telescope and developing a new high performance computing (HPC) enabled data management system (DESDM). The DESDM system will be used for processing, calibrating and serving the DES data. The total data volumes are high (~2PB), and so considerable effort has gone into designing an automated processing and quality control system. Special purpose image detrending and photometric calibration codes have been developed to meet the data quality requirements, while survey astrometric calibration, coaddition and cataloging rely on new extensions of the AstrOmatic codes which now include tools for PSF modeling, PSF homogenization, PSF corrected model fitting cataloging and joint model fitting across multiple input images. The DESDM system has been deployed on dedicated development clusters and HPC systems in the US and Germany. An extensive program of testing with small rapid turn-around and larger campaign simulated datasets has been carried out. The system has also been tested on large real datasets, including Blanco Cosmology Survey data from the Mosaic2 camera. In Fall 2012 the DESDM system will be used for DECam commissioning, and, thereafter, the system will go into full science operations.

  1. AUTOMATED TRANSIENT IDENTIFICATION IN THE DARK ENERGY SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, D. A.; D’Andrea, C. B.; Fischer, J. A.; Foley, R. J.; Gupta, R. R.; Kessler, R.; Kim, A. G.; Nichol, R. C.; Nugent, P. E.; Papadopoulos, A.; Sako, M.; Smith, M.; Sullivan, M.; Thomas, R. C.; Wester, W.; Wolf, R. C.; Abdalla, F. B.; Banerji, M.; Benoit-Lévy, A.; Bertin, E.; Brooks, D.; Rosell, A. Carnero; Castander, F. J.; Costa, L. N. da; Covarrubias, R.; DePoy, D. L.; Desai, S.; Diehl, H. T.; Doel, P.; Eifler, T. F.; Neto, A. Fausti; Finley, D. A.; Flaugher, B.; Fosalba, P.; Frieman, J.; Gerdes, D.; Gruen, D.; Gruendl, R. A.; James, D.; Kuehn, K.; Kuropatkin, N.; Lahav, O.; Li, T. S.; Maia, M. A. G.; Makler, M.; March, M.; Marshall, J. L.; Martini, P.; Merritt, K. W.; Miquel, R.; Nord, B.; Ogando, R.; Plazas, A. A.; Romer, A. K.; Roodman, A.; Sanchez, E.; Scarpine, V.; Schubnell, M.; Sevilla-Noarbe, I.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thaler, J.; Walker, A. R.

    2015-08-20

    We describe an algorithm for identifying point-source transients and moving objects on reference-subtracted optical images containing artifacts of processing and instrumentation. The algorithm makes use of the supervised machine learning technique known as Random Forest. We present results from its use in the Dark Energy Survey Supernova program (DES-SN), where it was trained using a sample of 898,963 signal and background events generated by the transient detection pipeline. After reprocessing the data collected during the first DES-SN observing season (2013 September through 2014 February) using the algorithm, the number of transient candidates eligible for human scanning decreased by a factor of 13.4, while only 1.0% of the artificial Type Ia supernovae (SNe) injected into search images to monitor survey efficiency were lost, most of which were very faint events. Here we characterize the algorithm's performance in detail, and we discuss how it can inform pipeline design decisions for future time-domain imaging surveys, such as the Large Synoptic Survey Telescope and the Zwicky Transient Facility. An implementation of the algorithm and the training data used in this paper are available at http://portal.nserc.gov/project/dessn/autoscan.

  2. THE HUBBLE SPACE TELESCOPE UV LEGACY SURVEY OF GALACTIC GLOBULAR CLUSTERS. VIII. PRELIMINARY PUBLIC CATALOG RELEASE

    Energy Technology Data Exchange (ETDEWEB)

    Soto, M.; Bellini, A.; Anderson, J.; Van der Marel, R. P.; Brown, T. M. [Space Telescope Science Institute, San Martin Drive 3700, Baltimore, MD 21218 (United States); Piotto, G.; Granata, V.; Ortolani, S.; Nardiello, D. [Dipartimento di Fisica e Astronomia Galileo Galilei, Università di Padova, Vicolo dell’Osservatorio 3, I-35122 Padova (Italy); Bedin, L. R. [INAF-Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, I-35122 Padova (Italy); Milone, A. P. [Research School of Astronomy and Astrophysics, The Australian National University, Cotter Road, Weston, ACT, 2611 (Australia); Cool, A. M. [Department of Physics and Astronomy, San Francisco State University, 1600 Holloway Avenue, San Francisco, CA 94132 (United States); King, I. R. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195-1580 (United States); Sarajedini, A. [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611 (United States); Cassisi, S. [Osservatorio Astronomico di Teramo, Via Mentore Maggini s.n.c., I-64100 Teramo (Italy); Aparicio, A.; Hidalgo, S., E-mail: mario.soto@uda.cl [Instituto de Astrofísica de Canarias, E-38200 La Laguna, Tenerife, Canary Islands (Spain)

    2017-01-01

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

  3. CANDELS: The Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey

    Science.gov (United States)

    Grogin, Norman A.; Koekemoer, anton M.; Faber, S. M.; Ferguson, Henry C.; Kocevski, Dale D.; Riess, Adam G.; Acquaviva, Viviana; Alexander, David M.; Almaini, Omar; Ashby, Matthew L. N.; hide

    2011-01-01

    The Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey (CANDELS) is designed to document the first third of galactic evolution, from z approx. 8 - 1.5. It will image > 250,000 distant galaxies using three separate cameras on the Hubble Space Tele8cope, from the mid-UV to near-IR, and will find and measure Type Ia supernovae beyond z > 1.5 to test their accuracy as standard candles for cosmology. Five premier multi-wavelength sky regions are selected, each with extensive ancillary data. The use of five widely separated fields mitigates cosmic variance and yields statistically robust and complete samples of galaxies down to a stellar mass of 10(exp 9) solar mass to z approx. 2, reaching the knee of the UV luminosity function of galaxies to z approx. 8. The survey covers approximately 800 square arc minutes and is divided into two parts. The CANDELS/Deep survey (5(sigma) point-source limit H =27.7mag) covers approx. 125 square arcminutes within GOODS-N and GOODS-S. The CANDELS/Wide survey includes GOODS and three additional fields (EGS, COSMOS, and UDS) and covers the full area to a 50(sigma) point-source limit of H ? or approx. = 27.0 mag. Together with the Hubble Ultradeep Fields, the strategy creates a three-tiered "wedding cake" approach that has proven efficient for extragalactic surveys. Data from the survey are non-proprietary and are useful for a wide variety of science investigations. In this paper, we describe the basic motivations for the survey, the CANDELS team science goals and the resulting observational requirements, the field selection and geometry, and the observing design.

  4. Effective Theory of Dark Energy at Redshift Survey Scales

    CERN Document Server

    Gleyzes, Jérôme; Mancarella, Michele; Vernizzi, Filippo

    2016-01-01

    We explore the phenomenological consequences of general late-time modifications of gravity in the quasi-static approximation, in the case where cold dark matter is non-minimally coupled to the gravitational sector. Assuming spectroscopic and photometric surveys with configuration parameters similar to those of the Euclid mission, we derive constraints on our effective description from three observables: the galaxy power spectrum in redshift space, tomographic weak-lensing shear power spectrum and the correlation spectrum between the integrated Sachs-Wolfe effect and the galaxy distribution. In particular, with $\\Lambda$CDM as fiducial model and a specific choice for the time dependence of our effective functions, we perform a Fisher matrix analysis and find that the unmarginalized $68\\%$ CL errors on the parameters describing the modifications of gravity are of order $\\sigma\\sim10^{-2}$--$10^{-3}$. We also consider two other fiducial models. A nonminimal coupling of CDM enhances the effects of modified gravit...

  5. Forward Global Photometric Calibration of the Dark Energy Survey

    Energy Technology Data Exchange (ETDEWEB)

    Burke, D. L.; Rykoff, E. S.; Allam, S.; Annis, J.; Bechtol, K.; Bernstein, G. M.; Drlica-Wagner, A.; Finley, D. A.; Gruendl, R. A.; James, D. J.; Kent, S.; Kessler, R.; Kuhlmann, S.; Lasker, J.; Li, T. S.; Scolnic, D.; Smith, J.; Tucker, D. L.; Wester, W.; Yanny, B.; Abbott, T. M. C.; Abdalla, F. B.; Benoit-Lévy, A.; Bertin, E.; Rosell, A. Carnero; Kind, M. Carrasco; Carretero, J.; Cunha, C. E.; D’Andrea, C. B.; da Costa, L. N.; Desai, S.; Diehl, H. T.; Doel, P.; Estrada, J.; García-Bellido, J.; Gruen, D.; Gutierrez, G.; Honscheid, K.; Kuehn, K.; Kuropatkin, N.; Maia, M. A. G.; March, M.; Marshall, J. L.; Melchior, P.; Menanteau, F.; Miquel, R.; Plazas, A. A.; Sako, M.; Sanchez, E.; Scarpine, V.; Schindler, R.; Sevilla-Noarbe, I.; Smith, M.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Suchyta, E.; Tarle, G.; Walker, A. R.

    2017-12-28

    Many scientific goals for the Dark Energy Survey (DES) require calibration of optical/NIR broadband $b = grizY$ photometry that is stable in time and uniform over the celestial sky to one percent or better. It is also necessary to limit to similar accuracy systematic uncertainty in the calibrated broadband magnitudes due to uncertainty in the spectrum of the source. Here we present a "Forward Global Calibration Method (FGCM)" for photometric calibration of the DES, and we present results of its application to the first three years of the survey (Y3A1). The FGCM combines data taken with auxiliary instrumentation at the observatory with data from the broad-band survey imaging itself and models of the instrument and atmosphere to estimate the spatial- and time-dependence of the passbands of individual DES survey exposures. "Standard" passbands are chosen that are typical of the passbands encountered during the survey. The passband of any individual observation is combined with an estimate of the source spectral shape to yield a magnitude $m_b^{\\mathrm{std}}$ in the standard system. This "chromatic correction" to the standard system is necessary to achieve sub-percent calibrations. The FGCM achieves reproducible and stable photometric calibration of standard magnitudes $m_b^{\\mathrm{std}}$ of stellar sources over the multi-year Y3A1 data sample with residual random calibration errors of $\\sigma=5-6\\,\\mathrm{mmag}$ per exposure. The accuracy of the calibration is uniform across the $5000\\,\\mathrm{deg}^2$ DES footprint to within $\\sigma=7\\,\\mathrm{mmag}$. The systematic uncertainties of magnitudes in the standard system due to the spectra of sources are less than $5\\,\\mathrm{mmag}$ for main sequence stars with $0.5

  6. Weak gravitational lensing systematic errors in the dark energy survey

    Science.gov (United States)

    Plazas, Andres Alejandro

    Dark energy is one of the most important unsolved problems in modern Physics, and weak gravitational lensing (WL) by mass structures along the line of sight ("cosmic shear") is a promising technique to learn more about its nature. However, WL is subject to numerous systematic errors which induce biases in measured cosmological parameters and prevent the development of its full potential. In this thesis, we advance the understanding of WL systematics in the context of the Dark Energy Survey (DES). We develop a testing suite to assess the performance of the shapelet-based DES WL measurement pipeline. We determine that the measurement bias of the parameters of our Point Spread Function (PSF) model scales as (S/N )-2, implying that a PSF S/N > 75 is needed to satisfy DES requirements. PSF anisotropy suppression also satisfies the requirements for source galaxies with S/N ≳ 45. For low-noise, marginally-resolved exponential galaxies, the shear calibration errors are up to about 0.06% (for shear values ≲ 0.075). Galaxies with S/N ≳ 75 present about 1% errors, sufficient for first-year DES data. However, more work is needed to satisfy full-area DES requirements, especially in the high-noise regime. We then implement tests to validate the high accuracy of the map between pixel coordinates and sky coordinates (astrometric solution), which is crucial to detect the required number of galaxies for WL in stacked images. We also study the effect of atmospheric dispersion on cosmic shear experiments such as DES and the Large Synoptic Survey Telescope (LSST) in the four griz bands. For DES (LSST), we find systematics in the g and r (g, r, and i) bands that are larger than required. We find that a simple linear correction in galaxy color is accurate enough to reduce dispersion shear systematics to insignificant levels in the r ( i) band for DES (LSST). More complex corrections will likely reduce the systematic cosmic-shear errors below statistical errors for LSST r band

  7. CO survey of the dark nebulae in Taurus and Perseus

    International Nuclear Information System (INIS)

    Baran, G.P.

    1986-01-01

    The thesis reports a large-scale survey of carbon monoxide ( 12 CO) emission (at λ = 2.6 mm) from dark nebulae in Taurus and Perseus. CO spectra at 4395 points were obtained within an area of about 800 square degrees generally west of the galactic anti-center. The spatial resolution of the instrument was eight arcminutes and velocity resolution was 2.6 km s -1 /. CO emission is strongest wherever extinction by dust is greatest, spilling over the apparent outer boundaries of the dust clouds observed optically. Combining CO velocity for the nebulae with optically determined distances shows that the clouds in the survey area form several layers. The molecular cloud mass closest to the sun is the Taurus and Auriga complex about 150 +/- 50 pc). Nearer to the Per )B2 OB association (at 350 +/- 100 pc) than the Taurus clouds are the Per OB2 molecular cloud (350 +/- 100 pc) and the California Nebula = NGC15979 molecular clouds (at 400 +/- 150 pc). Cloud masses were determined from integrated CO emission intensity alone by assuming that γ-ray emission intensities can be used to relate H 2 column densities to CO emission intensities

  8. Dark Energy Survey Year 1 Results: Weak Lensing Shape Catalogues

    Energy Technology Data Exchange (ETDEWEB)

    Zuntz, J.; et al.

    2017-08-04

    We present two galaxy shape catalogues from the Dark Energy Survey Year 1 data set, covering 1500 square degrees with a median redshift of $0.59$. The catalogues cover two main fields: Stripe 82, and an area overlapping the South Pole Telescope survey region. We describe our data analysis process and in particular our shape measurement using two independent shear measurement pipelines, METACALIBRATION and IM3SHAPE. The METACALIBRATION catalogue uses a Gaussian model with an innovative internal calibration scheme, and was applied to $riz$-bands, yielding 34.8M objects. The IM3SHAPE catalogue uses a maximum-likelihood bulge/disc model calibrated using simulations, and was applied to $r$-band data, yielding 21.9M objects. Both catalogues pass a suite of null tests that demonstrate their fitness for use in weak lensing science. We estimate the 1$\\sigma$ uncertainties in multiplicative shear calibration to be $0.013$ and $0.025$ for the METACALIBRATION and IM3SHAPE catalogues, respectively.

  9. PLANETARY NEBULAE DETECTED IN THE SPITZER SPACE TELESCOPE GLIMPSE II LEGACY SURVEY

    International Nuclear Information System (INIS)

    Zhang Yong; Sun Kwok

    2009-01-01

    We report the result of a search for the infrared counterparts of 37 planetary nebulae (PNs) and PN candidates in the Spitzer Galactic Legacy Infrared Mid-Plane Survey Extraordinaire II (GLIMPSE II) survey. The photometry and images of these PNs at 3.6, 4.5, 5.8, 8.0, and 24 μm, taken through the Infrared Array Camera (IRAC) and the Multiband Imaging Photometer for Spitzer (MIPS), are presented. Most of these nebulae are very red and compact in the IRAC bands, and are found to be bright and extended in the 24 μm band. The infrared morphology of these objects are compared with Hα images of the Macquarie-AAO-Strasbourg (MASH) and MASH II PNs. The implications for morphological difference in different wavelengths are discussed. The IRAC data allow us to differentiate between PNs and H II regions and be able to reject non-PNs from the optical catalog (e.g., PNG 352.1 - 00.0). Spectral energy distributions are constructed by combing the IRAC and MIPS data with existing near-, mid-, and far-IR photometry measurements. The anomalous colors of some objects allow us to infer the presence of aromatic emission bands. These multi-wavelength data provide useful insights into the nature of different nebular components contributing to the infrared emission of PNs.

  10. Black Hole Masses for Type I Active Galactic Nuclei in the Chandra Cosmos Legacy Survey

    Science.gov (United States)

    Nagaraj, Gautam; Fornasini, Francesca; Civano, Francesca Maria

    2018-01-01

    Tight local relations between SMBH masses and galaxy properties have established the fundamental connection between SMBHs and their host galaxies. However, in order to better understand the coevolution of SMBHs and their host galaxies over cosmic time, we need measurements of black hole masses, AGN luminosities, and galaxy stellar masses from sizable samples of AGN covering lower luminosities than the brightest quasars spanning a wide redshift range. In this study, we report masses of the SMBHs of 224 Type I AGNs from the Chandra COSMOS Legacy Survey as determined by the line widths of Mg II 2798, Hb 4862, and Ha 6564 via scaling relations derived from reverberation mapping. Preliminary comparison with host galaxy luminosities and stellar masses suggests an increase in Eddington ratio with redshift, consistent with previous studies. In addition, our derived SMBH masses fall above the local AGN MBH--M* (galactic stellar mass) relation from Reines & Volonteri (2015), but it is still not clear whether this results from redshift evolution of the MBH--M* relation or from the incompleteness of the spectroscopic surveys available. The SAO REU program is funded by the National Science Foundation REU and Department of Defense ASSURE programs under NSF Grant AST-1659473, and by the Smithsonian Institution.

  11. Information Management System Supporting a Multiple Property Survey Program with Legacy Radioactive Contamination.

    Science.gov (United States)

    Stager, Ron; Chambers, Douglas; Wiatzka, Gerd; Dupre, Monica; Callough, Micah; Benson, John; Santiago, Erwin; van Veen, Walter

    2017-04-01

    The Port Hope Area Initiative is a project mandated and funded by the Government of Canada to remediate properties with legacy low-level radioactive waste contamination in the Town of Port Hope, Ontario. The management and use of large amounts of data from surveys of some 4800 properties is a significant task critical to the success of the project. A large amount of information is generated through the surveys, including scheduling individual field visits to the properties, capture of field data laboratory sample tracking, QA/QC, property report generation and project management reporting. Web-mapping tools were used to track and display temporal progress of various tasks and facilitated consideration of spatial associations of contamination levels. The IM system facilitated the management and integrity of the large amounts of information collected, evaluation of spatial associations, automated report reproduction and consistent application and traceable execution for this project.x. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. The SAGES Legacy Unifying Globulars and Galaxies survey (SLUGGS): sample definition, methods, and initial results

    Energy Technology Data Exchange (ETDEWEB)

    Brodie, Jean P.; Romanowsky, Aaron J.; Jennings, Zachary G.; Pota, Vincenzo; Kader, Justin; Roediger, Joel C.; Villaume, Alexa; Arnold, Jacob A.; Woodley, Kristin A. [University of California Observatories, 1156 High Street, Santa Cruz, CA 95064 (United States); Strader, Jay [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Forbes, Duncan A.; Pastorello, Nicola; Usher, Christopher; Blom, Christina; Kartha, Sreeja S. [Centre for Astrophysics and Supercomputing, Swinburne University, Hawthorn, VIC 3122 (Australia); Foster, Caroline; Spitler, Lee R., E-mail: jbrodie@ucsc.edu [Australian Astronomical Observatory, P.O. Box 915, North Ryde, NSW 1670 (Australia)

    2014-11-20

    We introduce and provide the scientific motivation for a wide-field photometric and spectroscopic chemodynamical survey of nearby early-type galaxies (ETGs) and their globular cluster (GC) systems. The SAGES Legacy Unifying Globulars and GalaxieS (SLUGGS) survey is being carried out primarily with Subaru/Suprime-Cam and Keck/DEIMOS. The former provides deep gri imaging over a 900 arcmin{sup 2} field-of-view to characterize GC and host galaxy colors and spatial distributions, and to identify spectroscopic targets. The NIR Ca II triplet provides GC line-of-sight velocities and metallicities out to typically ∼8 R {sub e}, and to ∼15 R {sub e} in some cases. New techniques to extract integrated stellar kinematics and metallicities to large radii (∼2-3 R {sub e}) are used in concert with GC data to create two-dimensional (2D) velocity and metallicity maps for comparison with simulations of galaxy formation. The advantages of SLUGGS compared with other, complementary, 2D-chemodynamical surveys are its superior velocity resolution, radial extent, and multiple halo tracers. We describe the sample of 25 nearby ETGs, the selection criteria for galaxies and GCs, the observing strategies, the data reduction techniques, and modeling methods. The survey observations are nearly complete and more than 30 papers have so far been published using SLUGGS data. Here we summarize some initial results, including signatures of two-phase galaxy assembly, evidence for GC metallicity bimodality, and a novel framework for the formation of extended star clusters and ultracompact dwarfs. An integrated overview of current chemodynamical constraints on GC systems points to separate, in situ formation modes at high redshifts for metal-poor and metal-rich GCs.

  13. The Swift Gamma-Ray Burst Host Galaxy Legacy Survey. I. Sample Selection and Redshift Distribution

    Science.gov (United States)

    Perley, D. A.; Kruhler, T.; Schulze, S.; Postigo, A. De Ugarte; Hjorth, J.; Berger, E.; Cenko, S. B.; Chary, R.; Cucchiara, A.; Ellis, R.; hide

    2016-01-01

    We introduce the Swift Gamma-Ray Burst Host Galaxy Legacy Survey (SHOALS), a multi-observatory high redshift galaxy survey targeting the largest unbiased sample of long-duration gamma-ray burst (GRB) hosts yet assembled (119 in total). We describe the motivations of the survey and the development of our selection criteria, including an assessment of the impact of various observability metrics on the success rate of afterglow-based redshift measurement. We briefly outline our host galaxy observational program, consisting of deep Spitzer/IRAC imaging of every field supplemented by similarly deep, multicolor optical/near-IR photometry, plus spectroscopy of events without preexisting redshifts. Our optimized selection cuts combined with host galaxy follow-up have so far enabled redshift measurements for 110 targets (92%) and placed upper limits on all but one of the remainder. About 20% of GRBs in the sample are heavily dust obscured, and at most 2% originate from z > 5.5. Using this sample, we estimate the redshift-dependent GRB rate density, showing it to peak at z approx. 2.5 and fall by at least an order of magnitude toward low (z = 0) redshift, while declining more gradually toward high (z approx. 7) redshift. This behavior is consistent with a progenitor whose formation efficiency varies modestly over cosmic history. Our survey will permit the most detailed examination to date of the connection between the GRB host population and general star-forming galaxies, directly measure evolution in the host population over cosmic time and discern its causes, and provide new constraints on the fraction of cosmic star formation occurring in undetectable galaxies at all redshifts.

  14. Archiving Legacy Images from International Tsunami Science Team (ITST) Surveys, 1946 - 2013

    Science.gov (United States)

    Synolakis, C.; Kong, L. S. L.; Elwany, H.; Arcos, N. P.; Dunbar, P. K.

    2016-12-01

    The ITIC, USC, Coastal Environments, and NOAA/NCEI have collaborated to gather legacy videos and photos from ITST surveys conducted since 1992, plus from 1946 and 1956, by the USC-TR. The images will become part of the NCEI online and searchable historical tsunami image database. The legacy videos and photos document the local conditions in the tsunami aftermath and are important resources for visualizing the tsunami and identifying patterns of impacts. The data provide invaluable insights into tsunami events, and this information will empower future generations to make informed decisions regarding the future management of ocean resources, local development, and safety protocols. Eyewitnesses are important sources for further understanding even well studied events, especially before 2000. Videos provide context - what residents were doing, what they felt, what they saw, what reactions helped them survive. Photographs document inundation extent. Together, they help to visualize the location and document human behavior and response of the built environment. For example, a flow mark inside a house that survived, versus a partially destroyed house, differentiates construction styles. While the scientific rationale behind tsunami surveys is obvious, ITST protocols strike the delicate balance between the prompt need to act to recover ephemeral scientific field evidence, and urgent priorities for search-and-rescue immediately after tsunami disasters. The data set includes over 50 videos of varying formats and over 3,000 internationally-sourced photos from 24 major tsunami events from 1946-2013: 01 April 1946 Unimak Island, Aleutians; 09 July 1956 Amorgos Island, Greece; 01 September 1992, Nicaragua; 12 December 1992, Flores; 02 June 1994, East Java; 04 October 1994, Shikotan; 14 November 1994, Mindoro, Philippines; 17 January 1994 Northridge; 09 October 1995, Manzanillo, Mexico; 17 February 1997, Biak, Indonesia; 21 February 1996 Chimbote, Peru; 17 August 1998 Aitape, PNG

  15. CALIFA, the Calar Alto Legacy Integral Field Area survey. IV. Third public data release

    Science.gov (United States)

    Sánchez, S. F.; García-Benito, R.; Zibetti, S.; Walcher, C. J.; Husemann, B.; Mendoza, M. A.; Galbany, L.; Falcón-Barroso, J.; Mast, D.; Aceituno, J.; Aguerri, J. A. L.; Alves, J.; Amorim, A. L.; Ascasibar, Y.; Barrado-Navascues, D.; Barrera-Ballesteros, J.; Bekeraitè, S.; Bland-Hawthorn, J.; Cano Díaz, M.; Cid Fernandes, R.; Cavichia, O.; Cortijo, C.; Dannerbauer, H.; Demleitner, M.; Díaz, A.; Dettmar, R. J.; de Lorenzo-Cáceres, A.; del Olmo, A.; Galazzi, A.; García-Lorenzo, B.; Gil de Paz, A.; González Delgado, R.; Holmes, L.; Iglésias-Páramo, J.; Kehrig, C.; Kelz, A.; Kennicutt, R. C.; Kleemann, B.; Lacerda, E. A. D.; López Fernández, R.; López Sánchez, A. R.; Lyubenova, M.; Marino, R.; Márquez, I.; Mendez-Abreu, J.; Mollá, M.; Monreal-Ibero, A.; Ortega Minakata, R.; Torres-Papaqui, J. P.; Pérez, E.; Rosales-Ortega, F. F.; Roth, M. M.; Sánchez-Blázquez, P.; Schilling, U.; Spekkens, K.; Vale Asari, N.; van den Bosch, R. C. E.; van de Ven, G.; Vilchez, J. M.; Wild, V.; Wisotzki, L.; Yıldırım, A.; Ziegler, B.

    2016-10-01

    This paper describes the third public data release (DR3) of the Calar Alto Legacy Integral Field Area (CALIFA) survey. Science-grade quality data for 667 galaxies are made public, including the 200 galaxies of the second public data release (DR2). Data were obtained with the integral-field spectrograph PMAS/PPak mounted on the 3.5 m telescope at the Calar Alto Observatory. Three different spectral setups are available: I) a low-resolution V500 setup covering the wavelength range 3745-7500 Å (4240-7140 Å unvignetted) with a spectral resolution of 6.0 Å (FWHM) for 646 galaxies, II) a medium-resolution V1200 setup covering the wavelength range 3650-4840 Å (3650-4620 Å unvignetted) with a spectral resolution of 2.3 Å (FWHM) for 484 galaxies, and III) the combination of the cubes from both setups (called COMBO) with a spectral resolution of 6.0 Å and a wavelength range between 3700-7500 Å (3700-7140 Å unvignetted) for 446 galaxies. The Main Sample, selected and observed according to the CALIFA survey strategy covers a redshift range between 0.005 and 0.03, spans the color-magnitude diagram and probes a wide range of stellar masses, ionization conditions, and morphological types. The Extension Sample covers several types of galaxies that are rare in the overall galaxy population and are therefore not numerous or absent in the CALIFA Main Sample. All the cubes in the data release were processed using the latest pipeline, which includes improved versions of the calibration frames and an even further improved image reconstruction quality. In total, the third data release contains 1576 datacubes, including ~1.5 million independent spectra. Based on observations collected at the Centro Astronómico Hispano Alemán (CAHA) at Calar Alto, operated jointly by the Max-Planck-Institut für Astronomie (MPIA) and the Instituto de Astrofísica de Andalucía (CSIC).The spectra are available at http://califa.caha.es/DR3

  16. THE ARECIBO LEGACY FAST ALFA SURVEY. IX. THE LEO REGION H I CATALOG, GROUP MEMBERSHIP, AND THE H I MASS FUNCTION FOR THE LEO I GROUP

    International Nuclear Information System (INIS)

    Stierwalt, Sabrina; Haynes, Martha P.; Giovanelli, Riccardo; Martin, Ann M.; Kent, Brian R.; Saintonge, Amelie; Karachentsev, Igor D.; Karachentseva, Valentina E.

    2009-01-01

    We present the catalog of H I sources extracted from the ongoing Arecibo Legacy Fast ALFA (ALFALFA) extragalactic H I line survey, found within the sky region bounded by 9 h 36 m h 36 m and +08 0 0 . The H I catalog presented here for this 118 deg 2 region is combined with the ones derived from surrounding regions also covered by the ALFALFA survey to examine the large-scale structure in the complex Leo region. Because of the combination of wide sky coverage and superior sensitivity, spatial and spectral resolution, the ALFALFA H I catalog of the Leo region improves significantly on the numbers of low H I mass sources as compared with those found in previous H I surveys. The H I mass function of the Leo I group presented here is dominated by low-mass objects: 45 of the 65 Leo I members have M H I 8 M-odot, yielding tight constraints on the low-mass slope of the Leo I H I mass function. The best-fit slope is α ≅ -1.41 + 0.2 - 0.1. A direct comparison between the ALFALFA H I line detections and an optical search of the Leo I region proves the advantage of the ALFALFA strategy in finding low-mass, gas-rich dwarfs. These results suggest the existence of a significant population of low surface brightness, gas-rich, yet still very low H I mass galaxies, and may reflect the same type of morphological segregation as is seen in the Local Group. While the low-mass end slope of the Leo I H I mass function is steeper than that determined for luminosity functions of the group, the slope still falls short of the values predicted by simulations of structure formation in the lambda cold dark matter paradigm.

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    , in combination with Cosmic Microwave Background (CMB) observations from Planck, cluster surveys such as that in the ESA Euclid project will be able to determine a time-independent w with subpercent precision. Likewise, if the dark energy sound horizon falls within the length scales probed by the cluster survey...

  18. CANDELS : THE COSMIC ASSEMBLY NEAR-INFRARED DEEP EXTRAGALACTIC LEGACY SURVEY-THE HUBBLE SPACE TELESCOPE OBSERVATIONS, IMAGING DATA PRODUCTS, AND MOSAICS

    NARCIS (Netherlands)

    Koekemoer, Anton M.; Faber, S. M.; Ferguson, Henry C.; Grogin, Norman A.; Kocevski, Dale D.; Koo, David C.; Lai, Kamson; Lotz, Jennifer M.; Lucas, Ray A.; McGrath, Elizabeth J.; Ogaz, Sara; Rajan, Abhijith; Riess, Adam G.; Rodney, Steve A.; Strolger, Louis; Casertano, Stefano; Castellano, Marco; Dahlen, Tomas; Dickinson, Mark; Dolch, Timothy; Fontana, Adriano; Giavalisco, Mauro; Grazian, Andrea; Guo, Yicheng; Hathi, Nimish P.; Huang, Kuang-Han; van der Wel, Arjen; Yan, Hao-Jing; Acquaviva, Viviana; Alexander, David M.; Almaini, Omar; Ashby, Matthew L. N.; Barden, Marco; Bell, Eric F.; Bournaud, Frederic; Brown, Thomas M.; Caputi, Karina I.; Cassata, Paolo; Challis, Peter J.; Chary, Ranga-Ram; Cheung, Edmond; Cirasuolo, Michele; Conselice, Christopher J.; Cooray, Asantha Roshan; Croton, Darren J.; Daddi, Emanuele; Dave, Romeel; de Mello, Duilia F.; de Ravel, Loic; Dekel, Avishai; Donley, Jennifer L.; Dunlop, James S.; Dutton, Aaron A.; Elbaz, David; Fazio, Giovanni G.; Filippenko, Alexei V.; Finkelstein, Steven L.; Frazer, Chris; Gardner, Jonathan P.; Garnavich, Peter M.; Gawiser, Eric; Gruetzbauch, Ruth; Hartley, Will G.; Haeussler, Boris; Herrington, Jessica; Hopkins, Philip F.; Huang, Jia-Sheng; Jha, Saurabh W.; Johnson, Andrew; Kartaltepe, Jeyhan S.; Khostovan, Ali A.; Kirshner, Robert P.; Lani, Caterina; Lee, Kyoung-Soo; Li, Weidong; Madau, Piero; McCarthy, Patrick J.; McIntosh, Daniel H.; McLure, Ross J.; McPartland, Conor; Mobasher, Bahram; Moreira, Heidi; Mortlock, Alice; Moustakas, Leonidas A.; Mozena, Mark; Nandra, Kirpal; Newman, Jeffrey A.; Nielsen, Jennifer L.; Niemi, Sami; Noeske, Kai G.; Papovich, Casey J.; Pentericci, Laura; Pope, Alexandra; Primack, Joel R.; Ravindranath, Swara; Reddy, Naveen A.; Renzini, Alvio; Rix, Hans-Walter; Robaina, Aday R.; Rosario, David J.; Rosati, Piero; Salimbeni, Sara; Scarlata, Claudia; Siana, Brian; Simard, Luc; Smidt, Joseph; Snyder, Diana; Somerville, Rachel S.; Spinrad, Hyron; Straughn, Amber N.; Telford, Olivia; Teplitz, Harry I.; Trump, Jonathan R.; Vargas, Carlos; Villforth, Carolin; Wagner, Cory R.; Wandro, Pat; Wechsler, Risa H.; Weiner, Benjamin J.; Wiklind, Tommy; Wild, Vivienne; Wilson, Grant; Wuyts, Stijn; Yun, Min S.

    2011-01-01

    This paper describes the Hubble Space Telescope imaging data products and data reduction procedures for the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS). This survey is designed to document the evolution of galaxies and black holes at z approximate to 1.5-8, and to study

  19. BIASED DARK ENERGY CONSTRAINTS FROM NEGLECTING REDUCED SHEAR IN WEAK-LENSING SURVEYS

    International Nuclear Information System (INIS)

    Shapiro, Charles

    2009-01-01

    The weak gravitational lensing of distant galaxies by a large-scale structure is expected to become a powerful probe of dark energy. By measuring the ellipticities of large number of background galaxies, the subtle gravitational distortion called 'cosmic shear' can be measured and used to constrain dark energy parameters. The observed galaxy ellipticities, however, are induced not by shear but by reduced shear, which also accounts for slight magnifications of the images. This distinction is negligible for present weak-lensing surveys, but it will become more important as we improve our ability to measure and understand small-angle cosmic shear modes. I calculate the discrepancy between shear and reduced shear in the context of power spectra and cross spectra, finding the difference could be as high as 10% on the smallest accessible angular scales. I estimate how this difference will bias dark energy parameters obtained from two weak-lensing methods: weak-lensing tomography and the shear ratio method known as offset-linear scaling. For weak-lensing tomography, ignoring the effects of reduced shear will cause future surveys considered by the Dark Energy Task Force to measure dark energy parameters that are biased by amounts comparable to their error bars. I advocate that reduced shear be properly accounted for in such surveys, and I provide a semi-analytic formula for doing so. Since reduced shear cross spectra do not follow an offset-linear scaling relation, the shear ratio method is similarly biased but with smaller significance.

  20. The 4MOST WAVES survey: A dark matter experiment

    OpenAIRE

    Driver, Simon

    2017-01-01

    Invited talk that covered Australia's entry to ESO, the development of complete redshift surveys, 4MOST, WAVES, GAMA, the CSFH, the stellar mass density and the dust mass density. Concluding with an invitation to attend the Final GAMA Data Release in Perth in November.

  1. Extreme Variability Quasars from the Sloan Digital Sky Survey and the Dark Energy Survey

    Science.gov (United States)

    Rumbaugh, N.; Shen, Yue; Morganson, Eric; Liu, Xin; Banerji, M.; McMahon, R. G.; Abdalla, F. B.; Benoit-Lévy, A.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Capozzi, D.; Carnero Rosell, A.; Carrasco Kind, M.; Carretero, J.; Cunha, C. E.; D’Andrea, C. B.; da Costa, L. N.; DePoy, D. L.; Desai, S.; Doel, P.; Frieman, J.; García-Bellido, J.; Gruen, D.; Gruendl, R. A.; Gschwend, J.; Gutierrez, G.; Honscheid, K.; James, D. J.; Kuehn, K.; Kuhlmann, S.; Kuropatkin, N.; Lima, M.; Maia, M. A. G.; Marshall, J. L.; Martini, P.; Menanteau, F.; Plazas, A. A.; Reil, K.; Roodman, A.; Sanchez, E.; Scarpine, V.; Schindler, R.; Schubnell, M.; Sheldon, E.; Smith, M.; Soares-Santos, M.; Sobreira, F.; Suchyta, E.; Swanson, M. E. C.; Walker, A. R.; Wester, W.; (DES Collaboration

    2018-02-01

    We perform a systematic search for long-term extreme variability quasars (EVQs) in the overlapping Sloan Digital Sky Survey and 3 Year Dark Energy Survey imaging, which provide light curves spanning more than 15 years. We identified ∼1000 EVQs with a maximum change in g-band magnitude of more than 1 mag over this period, about 10% of all quasars searched. The EVQs have L bol ∼ 1045–1047 erg s‑1 and L/L Edd ∼ 0.01–1. Accounting for selection effects, we estimate an intrinsic EVQ fraction of ∼30%–50% among all g≲ 22 quasars over a baseline of ∼15 yr. We performed detailed multi-wavelength, spectral, and variability analyses for the EVQs and compared them to their parent quasar sample. We found that EVQs are distinct from a control sample of quasars matched in redshift and optical luminosity: (1) their UV broad emission lines have larger equivalent widths; (2) their Eddington ratios are systematically lower; and (3) they are more variable on all timescales. The intrinsic difference in quasar properties for EVQs suggests that internal processes associated with accretion are the main driver for the observed extreme long-term variability. However, despite their different properties, EVQs seem to be in the tail of a continuous distribution of quasar properties, rather than standing out as a distinct population. We speculate that EVQs are normal quasars accreting at relatively low rates, where the accretion flow is more likely to experience instabilities that drive the changes in flux by a factor of a few on multi-year timescales.

  2. Extreme Variability Quasars from the Sloan Digital Sky Survey and the Dark Energy Survey

    Energy Technology Data Exchange (ETDEWEB)

    Rumbaugh, N.; Shen, Yue; Morganson, Eric; Liu, Xin; Banerji, M.; McMahon, R. G.; Abdalla, F. B.; Benoit-Lévy, A.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Capozzi, D.; Carnero Rosell, A.; Carrasco Kind, M.; Carretero, J.; Cunha, C. E.; D’Andrea, C. B.; da Costa, L. N.; DePoy, D. L.; Desai, S.; Doel, P.; Frieman, J.; García-Bellido, J.; Gruen, D.; Gruendl, R. A.; Gschwend, J.; Gutierrez, G.; Honscheid, K.; James, D. J.; Kuehn, K.; Kuhlmann, S.; Kuropatkin, N.; Lima, M.; Maia, M. A. G.; Marshall, J. L.; Martini, P.; Menanteau, F.; Plazas, A. A.; Reil, K.; Roodman, A.; Sanchez, E.; Scarpine, V.; Schindler, R.; Schubnell, M.; Sheldon, E.; Smith, M.; Soares-Santos, M.; Sobreira, F.; Suchyta, E.; Swanson, M. E. C.; Walker, A. R.; Wester, W.

    2018-02-20

    We perform a systematic search for long-term extreme variability quasars (EVQs) in the overlapping Sloan Digital Sky Survey (SDSS) and 3-Year Dark Energy Survey (DES) imaging, which provide light curves spanning more than 15 years. We identified ~1000 EVQs with a maximum g band magnitude change of more than 1 mag over this period, about 10% of all quasars searched. The EVQs have L_bol~10^45-10^47 erg/s and L/L_Edd~0.01-1. Accounting for selection effects, we estimate an intrinsic EVQ fraction of ~30-50% among all g<~22 quasars over a baseline of ~15 years. These EVQs are good candidates for so-called "changing-look quasars", where a spectral transition between the two types of quasars (broad-line and narrow-line) is observed between the dim and bright states. We performed detailed multi-wavelength, spectral and variability analyses for the EVQs and compared to their parent quasar sample. We found that EVQs are distinct from a control sample of quasars matched in redshift and optical luminosity: (1) their UV broad emission lines have larger equivalent widths; (2) their Eddington ratios are systematically lower; and (3) they are more variable on all timescales. The intrinsic difference in quasar properties for EVQs suggest that internal processes associated with accretion are the main driver for the observed extreme long-term variability. However, despite their different properties, EVQs seem to be in the tail of a continuous distribution of quasar properties, rather than standing out as a distinct population. We speculate that EVQs are normal quasars accreting at relatively low accretion rates, where the accretion flow is more likely to experience instabilities that drive the factor of few changes in flux on multi-year timescales.

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

    NARCIS (Netherlands)

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

    2017-01-01

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

  4. Weak lensing magnification in the Dark Energy Survey Science Verification data

    Science.gov (United States)

    Garcia-Fernandez, M.; Sanchez, E.; Sevilla-Noarbe, I.; Suchyta, E.; Huff, E. M.; Gaztanaga, E.; Aleksić, J.; Ponce, R.; Castander, F. J.; Hoyle, B.; Abbott, T. M. C.; Abdalla, F. B.; Allam, S.; Annis, J.; Benoit-Lévy, A.; Bernstein, G. M.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Burke, D. L.; Carnero Rosell, A.; Carrasco Kind, M.; Carretero, J.; Crocce, M.; Cunha, C. E.; D'Andrea, C. B.; da Costa, L. N.; DePoy, D. L.; Desai, S.; Diehl, H. T.; Eifler, T. F.; Evrard, A. E.; Fernandez, E.; Flaugher, B.; Fosalba, P.; Frieman, J.; García-Bellido, J.; Gerdes, D. W.; Giannantonio, T.; Gruen, D.; Gruendl, R. A.; Gschwend, J.; Gutierrez, G.; James, D. J.; Jarvis, M.; Kirk, D.; Krause, E.; Kuehn, K.; Kuropatkin, N.; Lahav, O.; Lima, M.; MacCrann, N.; Maia, M. A. G.; March, M.; Marshall, J. L.; Melchior, P.; Miquel, R.; Mohr, J. J.; Plazas, A. A.; Romer, A. K.; Roodman, A.; Rykoff, E. S.; Scarpine, V.; Schubnell, M.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Tarle, G.; Thomas, D.; Walker, A. R.; Wester, W.

    2018-02-01

    In this paper the effect of weak lensing magnification on galaxy number counts is studied by cross-correlating the positions of two galaxy samples, separated by redshift, using the Dark Energy Survey Science Verification dataset. This analysis is carried out for galaxies that are selected only by its photometric redshift. An extensive analysis of the systematic effects, using new methods based on simulations is performed, including a Monte Carlo sampling of the selection function of the survey.

  5. Weak lensing magnification in the Dark Energy Survey Science Verification data

    Science.gov (United States)

    Garcia-Fernandez, M.; Sanchez, E.; Sevilla-Noarbe, I.; Suchyta, E.; Huff, E. M.; Gaztanaga, E.; Aleksić, J.; Ponce, R.; Castander, F. J.; Hoyle, B.; Abbott, T. M. C.; Abdalla, F. B.; Allam, S.; Annis, J.; Benoit-Lévy, A.; Bernstein, G. M.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Burke, D. L.; Carnero Rosell, A.; Carrasco Kind, M.; Carretero, J.; Crocce, M.; Cunha, C. E.; D'Andrea, C. B.; da Costa, L. N.; DePoy, D. L.; Desai, S.; Diehl, H. T.; Eifler, T. F.; Evrard, A. E.; Fernandez, E.; Flaugher, B.; Fosalba, P.; Frieman, J.; García-Bellido, J.; Gerdes, D. W.; Giannantonio, T.; Gruen, D.; Gruendl, R. A.; Gschwend, J.; Gutierrez, G.; James, D. J.; Jarvis, M.; Kirk, D.; Krause, E.; Kuehn, K.; Kuropatkin, N.; Lahav, O.; Lima, M.; MacCrann, N.; Maia, M. A. G.; March, M.; Marshall, J. L.; Melchior, P.; Miquel, R.; Mohr, J. J.; Plazas, A. A.; Romer, A. K.; Roodman, A.; Rykoff, E. S.; Scarpine, V.; Schubnell, M.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Tarle, G.; Thomas, D.; Walker, A. R.; Wester, W.; DES Collaboration

    2018-05-01

    In this paper, the effect of weak lensing magnification on galaxy number counts is studied by cross-correlating the positions of two galaxy samples, separated by redshift, using the Dark Energy Survey Science Verification data set. This analysis is carried out for galaxies that are selected only by its photometric redshift. An extensive analysis of the systematic effects, using new methods based on simulations is performed, including a Monte Carlo sampling of the selection function of the survey.

  6. Dark energy and neutrino constraints from a future EUCLID-like survey

    DEFF Research Database (Denmark)

    Basse, Tobias; Eggers Bjaelde, Ole; Hamann, Jan

    2013-01-01

    vastly improves the survey's potential to measure the time evolution of dark energy. In terms of a dark energy figure-of-merit defined as (sigma(w_0) sigma(w_a))^-1, we find a value of 454 for Euclid-like data combined with Planck-like measurements of the cosmic microwave background (CMB) anisotropies...... from -1, models with c_s^2 = 10^-6 and c_s^2 = 1 can be distinguished at more than 2sigma significance. Under the same optimistic assumptions, if the Jeans mass associated with dark energy clustering falls within the cluster mass range observed by the survey, then the order of magnitude of the dark...... energy sound speed can potentially be pinned down. Finally, we find that the sum of neutrino masses can be measured with a 1sigma precision of 0.01eV, even in complex cosmological models in which the dark energy equation of state varies with time. (abridged)...

  7. Optimizing Spectroscopic and Photometric Galaxy Surveys: Same-Sky Benefits for Dark Energy and Modified Gravity

    Energy Technology Data Exchange (ETDEWEB)

    Kirk, Donnacha [University Coll. London; Lahav, Ofer [University Coll. London; Bridle, Sarah [Manchester U.; Jouvel, Stephanie [Barcelona, IEEC; Abdalla, Filipe B. [University Coll. London; Frieman, Joshua A. [Chicago U., KICP

    2015-08-21

    The combination of multiple cosmological probes can produce measurements of cosmological parameters much more stringent than those possible with any individual probe. We examine the combination of two highly correlated probes of late-time structure growth: (i) weak gravitational lensing from a survey with photometric redshifts and (ii) galaxy clustering and redshift space distortions from a survey with spectroscopic redshifts. We choose generic survey designs so that our results are applicable to a range of current and future photometric redshift (e.g. KiDS, DES, HSC, Euclid) and spectroscopic redshift (e.g. DESI, 4MOST, Sumire) surveys. Combining the surveys greatly improves their power to measure both dark energy and modified gravity. An independent, non-overlapping combination sees a dark energy figure of merit more than 4 times larger than that produced by either survey alone. The powerful synergies between the surveys are strongest for modified gravity, where their constraints are orthogonal, producing a non-overlapping joint figure of merit nearly 2 orders of magnitude larger than either alone. Our projected angular power spectrum formalism makes it easy to model the cross-correlation observable when the surveys overlap on the sky, producing a joint data vector and full covariance matrix. We calculate a same-sky improvement factor, from the inclusion of these cross-correlations, relative to non-overlapping surveys. We find nearly a factor of 4 for dark energy and more than a factor of 2 for modified gravity. The exact forecast figures of merit and same-sky benefits can be radically affected by a range of forecasts assumption, which we explore methodically in a sensitivity analysis. We show that that our fiducial assumptions produce robust results which give a good average picture of the science return from combining photometric and spectroscopic surveys.

  8. The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX): Description and Early Pilot Survey Results

    Science.gov (United States)

    Hill, G. J.; Gebhardt, K.; Komatsu, E.; Drory, N.; MacQueen, P. J.; Adams, J.; Blanc, G. A.; Koehler, R.; Rafal, M.; Roth, M. M.; Kelz, A.; Gronwall, C.; Ciardullo, R.; Schneider, D. P.

    2008-10-01

    The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) will outfit the 10 m HET with a new wide field and an array of 150 integral-field spectrographs to survey a 420 deg^2 area in the north Galactic cap. Each fiber-coupled unit spectrograph will cover 350-550 nm, simultaneously. This instrument, called VIRUS, will produce ˜34,000 spectra per exposure, and will open up the emission-line universe to large surveys for the first time. The survey will detect 0.8 million Lyman-alpha emitting (LAE) galaxies with 1.9LAE galaxies in 9 cubic Gpc volume will be used to measure the expansion history at this early epoch using baryonic acoustic oscillations and the shape of the power spectrum. The aim of HETDEX is to provide a direct detection of dark energy at z˜3. The measurement will constrain the evolution of dark energy and will also provide 0.1%-level accuracy on the curvature of the Universe, ten times better than current. The prototype of the VIRUS unit spectrograph (VIRUS-P) is a powerful instrument in its own right. Used on the McDonald 2.7~m, it covers the largest area of any integral field spectrograph, and reaches wavelengths down to 340 nm. VIRUS-P is being used for a pilot survey to better measure the properties of LAE galaxies in support of HETDEX. We report initial results from this survey.

  9. Legacies of stream channel modification revealed using General Land Office surveys, with implications for water temperature and aquatic life

    Directory of Open Access Journals (Sweden)

    Seth M. White

    2017-02-01

    Full Text Available Land use legacies can have a discernible influence in present-day watersheds and should be accounted for when designing conservation strategies for riverine aquatic life. We describe the environmental history of three watersheds within the Grande Ronde subbasin of the Columbia River using General Land Office survey field notes from the 19th century. In the two watersheds severely impacted by Euro-American land use, stream channel widths—a metric representing habitat simplification—increased from an average historical width of 16.8 m to an average present width of 20.8 m in large streams; 4.3 m to 5.5 m in small, confined or partly confined streams; and 3.5 m to 6.5 m in small, laterally unconfined steams. Conversely, we did not detect significant change in stream widths in an adjacent, wilderness stream with minimal human impact. Using a mechanistic water temperature model and restoration scenarios based on the historical condition, we predicted that stream restoration in the impacted watersheds could notably decrease average water temperatures—especially when channel narrowing is coupled with riparian restoration—up to a 6.6°C reduction in the upper Grande Ronde River and 3.0°C in Catherine Creek. These reductions in water temperature translated to substantial changes in the percentage of stream network habitable to salmon and steelhead migration (from 29% in the present condition to 79% in the fully restored scenario and to core juvenile rearing (from 13% in the present condition to 36% in the fully restored scenario. We conclude that land use legacies leave an important footprint on the present landscape and are critical for understanding historic habitat-forming processes as a necessary first step towards restoration.

  10. The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX): Description and Early Pilot Survey Results

    OpenAIRE

    Hill, G. J.; Gebhardt, K.; Komatsu, E.; Drory, N.; MacQueen, P. J.; Adams, J.; Blanc, G. A.; Koehler, R.; Rafal, M.; Roth, M. M.; Kelz, A.; Gronwall, C.; Ciardullo, R.; Schneider, D. P.

    2008-01-01

    The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) will outfit the 10 m HET with a new wide field and an array of 150 integral-field spectrographs to survey a 420 sq. deg. area in the north Galactic cap. Each fiber-coupled unit spectrograph will cover 350-550 nm, simultaneously. This instrument, called VIRUS, will produce ~34,000 spectra per exposure, and will open up the emission-line universe to large surveys for the first time. The survey will detect 0.8 million Lyman-alpha emittin...

  11. PreCam: A Precursor Observational Campaign for Calibration of the Dark Energy Survey

    Energy Technology Data Exchange (ETDEWEB)

    Kuehn, K.; Kuhlmann, S.; Allam, S.; Annis, J. T.; Bailey, T.; Balbinot, E.; Bernstein, J. P.; Biesiadzinski, T.; Burke, D. L.; Butner, M.; Camargo, J. I. B.; da Costa, L. A. N.; DePoy, D.; Diehl, H. T.; Dietrich, J. P.; Estrada, J.; Fausti, A.; Gerke, B.; Guarino, V.; Head, H. H.; Kessler, R.; Lin, H.; Lorenzon, W.; Maia, M. A. G.; Maki, L.; Marshall, J.; Nord, B.; Neilsen, E.; Ogando, R. L. C.; Park, D.; Peoples, J.; Rastawicki, D.; Rheault, J. -P.; Santiago, B.; Schubnell, M.; Seitzer, P.; Smith, J. A.; Spinka, H.; Sypniewski, A.; Tarle, G.; Tucker, D. L.; Walker, A. R.; Wester, W.

    2013-04-01

    PreCam, a precursor observational campaign supporting the Dark Energy Survey (DES), is designed to produce a photometric and astrometric catalog of nearly a hundred thousand standard stars within the DES footprint, while the PreCam instrument also serves as a prototype testbed for the Dark Energy Camera's hardware and software. This catalog represents a potential 100-fold increase in Southern Hemisphere photometric standard stars, and therefore will be an important component in the calibration of the Dark Energy Survey. We provide details on the PreCam instrument's design, construction, and testing, as well as results from a subset of the 51 nights of PreCam survey observations on the University of Michigan Department of Astronomy's Curtis-Schmidt telescope at Cerro Tololo Inter-American Observatory (CTIO). We briefly describe the preliminary data processing pipeline that has been developed for PreCam data and the preliminary results of the instrument performance, as well as astrometry and photometry of a sample of stars previously included in other southern sky surveys.

  12. The Supernova Legacy Survey: Measurement of Omega_M, Omega_Lambda, and w from the First Year Data Set

    Science.gov (United States)

    Astier, P.; Guy, J.; Regnault, N.; Pain, R.; Aubourg, E.; Balam, D.; Basa, S.; Carlberg, R. G.; Fabbro, S.; Fouchez, D.; Hook, I. M.; Howell, D. A.; Lafoux, H.; Neill, J. D.; Palanque-Delabrouille, N.; Perrett, K.; Pritchet, C. J.; Rich, J.; Sullivan, M.; Taillet, R.; Aldering, G.; Antilogus, P.; Arsenijevic, V.; Balland, C.; Baumont, S.; Bronder, J.; Courtois, H.; Ellis, R. S.; Filiol, M.; Goncalves, A. C.; Goobar, A.; Guide, D.; Hardin, D.; Lusset, V.; Lidman, C.; McMahon, R.; Mouchet, M.; Mourao, A.; Perlmutter, S.; Ripoche, P.; Tao, C.; Walton, N.

    2005-10-14

    We present distance measurements to 71 high redshift type Ia supernovae discovered during the first year of the 5-year Supernova Legacy Survey (SNLS). These events were detected and their multi-color light-curves measured using the MegaPrime/MegaCam instrument at the Canada-France-Hawaii Telescope (CFHT), by repeatedly imaging four one-square degree fields in four bands. Follow-up spectroscopy was performed at the VLT, Gemini and Keck telescopes to confirm the nature of the supernovae and to measure their redshift. With this data set, we have built a Hubble diagram extending to z = 1, with all distance measurements involving at least two bands. Systematic uncertainties are evaluated making use of the multiband photometry obtained at CFHT. Cosmological fits to this first year SNLS Hubble diagram give the following results: {Omega}{sub M} = 0.263 {+-} 0.042 (stat) {+-} 0.032 (sys) for a flat {Lambda}CDM model; and w = -1.023 {+-} 0.090 (stat) {+-} 0.054 (sys) for a flat cosmology with constant equation of state w when combined with the constraint from the recent Sloan Digital Sky Survey measurement of baryon acoustic oscillations.

  13. An Unbiased Survey of 500 Nearby Stars for Debris Disks: A JCMT Legacy Program

    NARCIS (Netherlands)

    Matthews, B.C.; Greaves, J.S.; Holland, W.S.; Wyatt, M.C.; Barlow, M.J.; Bastien, P.; Beichman, C.A.; Biggs, A.; Butner, H.M.; Dent, W.R.F.; Francesco, J. Di; Dominik, C.; Fissel, L.; Friberg, P.; Gibb, A.G.; Halpern, M.; Ivison, R.J.; Jayawardhana, R.; Jenness, T.; Johnstone, D.; Kavelaars, J.J.; Marshall, J.L.; Phillips, N.; Schieven, G.; Snellen, I.A.G.; Walker, H.J.; Ward-Thompson, D.; Weferling, B.; White, G.J.; Yates, J.; Zhu, M.; Craigon, A.

    2007-01-01

    We present the scientific motivation and observing plan for an upcoming detection survey for debris disks using the James Clerk Maxwell Telescope. The SCUBA-2 Unbiased Nearby Stars (SUNS) survey will observe 500 nearby main-sequence and subgiant stars (100 of each of the A, F, G, K, and M spectral

  14. Hubble space telescope/advanced camera for surveys confirmation of the dark substructure in A520

    International Nuclear Information System (INIS)

    Jee, M. J.; Hoekstra, H.; Mahdavi, A.; Babul, A.

    2014-01-01

    We present a weak-lensing study of the cluster A520 based on Advanced Camera for Surveys (ACS) data. The excellent data quality provides a mean source density of ∼109 arcmin –2 , which improves both resolution and significance of the mass reconstruction compared to a previous study based on Wide Field Planetary Camera 2 (WFPC2) images. We take care in removing instrumental effects such as the charge trailing due to radiation damage of the detector and the position-dependent point-spread function. This new ACS analysis confirms the previous claims that a substantial amount of dark mass is present between two luminous subclusters where we observe very little light. The centroid of the dark peak in the current ACS analysis is offset to the southwest by ∼1' with respect to the centroid from the WFPC2 analysis. Interestingly, this new centroid is in better agreement with the location where the X-ray emission is strongest, and the mass-to-light ratio estimated with this centroid is much higher (813 ± 78 M ☉ /L R☉ ) than the previous value; the aperture mass with the WFPC2 centroid provides a consistent mass. Although we cannot provide a definite explanation for the dark peak, we discuss a revised scenario, wherein dark matter with a more conventional range (σ DM /m DM < 1 cm 2 g –1 ) of self-interacting cross-section can lead to the detection of this dark substructure. If supported by detailed numerical simulations, this hypothesis opens up the possibility that the A520 system can be used to establish a lower limit of the self-interacting cross-section of dark matter.

  15. Comparison of the linear bias models in the light of the Dark Energy Survey

    Science.gov (United States)

    Papageorgiou, A.; Basilakos, S.; Plionis, M.

    2018-05-01

    The evolution of the linear and scale independent bias, based on the most popular dark matter bias models within the Λ cold dark matter (ΛCDM) cosmology, is confronted to that of the Dark Energy Survey (DES) luminous red galaxies (LRGs). Applying a χ2 minimization procedure between models and data, we find that all the considered linear bias models reproduce well the LRG bias data. The differences among the bias models are absorbed in the predicted mass of the dark-matter halo in which LRGs live and which ranges between ˜6 × 1012 and 1.4 × 1013 h-1 M⊙, for the different bias models. Similar results, reaching however a maximum value of ˜2 × 1013 h-1 M⊙, are found by confronting the SDSS (2SLAQ) Large Red Galaxies clustering with theoretical clustering models, which also include the evolution of bias. This later analysis also provides a value of Ωm = 0.30 ± 0.01, which is in excellent agreement with recent joint analyses of different cosmological probes and the reanalysis of the Planck data.

  16. Predictions of Planet Detections with Near-infrared Radial Velocities in the Upcoming SPIRou Legacy Survey-planet Search

    Science.gov (United States)

    Cloutier, Ryan; Artigau, Étienne; Delfosse, Xavier; Malo, Lison; Moutou, Claire; Doyon, René; Donati, Jean-Francois; Cumming, Andrew; Dumusque, Xavier; Hébrard, Élodie; Menou, Kristen

    2018-02-01

    The SPIRou near-infrared spectropolarimeter is destined to begin science operations at the Canada–France–Hawaii Telescope in mid-2018. One of the instrument’s primary science goals is to discover the closest exoplanets to the solar system by conducting a three- to five-year long radial velocity survey of nearby M dwarfs at an expected precision of ∼1 m s‑1, the SPIRou Legacy Survey-Planet Search (SLS-PS). In this study, we conduct a detailed Monte Carlo simulation of the SLS-PS using our current understanding of the occurrence rate of M dwarf planetary systems and physical models of stellar activity. From simultaneous modeling of planetary signals and activity, we predict the population of planets to be detected in the SLS-PS. With our fiducial survey strategy and expected instrument performance over a nominal survey length of ∼3 years, we expect SPIRou to detect {85.3}-12.4+29.3 planets including {20.0}-7.2+16.8 habitable-zone planets and {8.1}-3.2+7.6 Earth-like planets from a sample of 100 M1–M8.5 dwarfs out to 11 pc. By studying mid-to-late M dwarfs previously inaccessible to existing optical velocimeters, SPIRou will put meaningful constraints on the occurrence rate of planets around those stars including the value of {η }\\oplus at an expected level of precision of ≲ 45 % . We also predict that a subset of {46.7}-6.0+16.0 planets may be accessible with dedicated high-contrast imagers on the next generation of extremely large telescopes including {4.9}-2.0+4.7 potentially imagable Earth-like planets. Lastly, we compare the results of our fiducial survey strategy to other foreseeable survey versions to quantify which strategy is optimized to reach the SLS-PS science goals. The results of our simulations are made available to the community on GitHub (https://github.com/r-cloutier/SLSPS_Simulations).

  17. An HST legacy ultraviolet spectroscopic survey of the 13pc white dwarf sample

    Science.gov (United States)

    Gaensicke, Boris

    2015-10-01

    Over 95% of all stars in the Galaxy will become white dwarfs, and this dominant population of stellar remnants plays a unique and central role for our understanding of the formation and evolution of stars, planetary systems, and the Galaxy itself. White dwarfs are fundamental for many areas of astrophysics, including post main-sequence mass loss, the local star formation history, the bulk composition of extra-solar planets, and the characterisation of dark energy.Despite their fundamental importance for a wide range of astrophysical problems, our knowledge of the galactic white dwarf population is remarkably fragmentary: the only volume-limited and unbiased sample of white dwarfs contains 43 stars within d team has carried out substantial theoretical and computational work on improved model atmospheres and all relevant input physics. The strongest effect of our new calculations on the emergent flux occurs at ultraviolet wavelengths, and we propose to obtain STIS and COS spectroscopy for all white dwarfs in the volume-limited 13pc sample to (1) test and calibrate our atmosphere models, which we will eventually apply to the 200000 WDs discovered by Gaia, (2) turn the 13pc sample into the most accurate cosmic clocks reconstructing the local star formation history, and (3) probe in an unbiased way the frequency of rocky planet formation in the early ages of the Galaxy.

  18. The SLUGGS survey: dark matter fractions at large radii and assembly epochs of early-type galaxies from globular cluster kinematics

    Science.gov (United States)

    Alabi, Adebusola B.; Forbes, Duncan A.; Romanowsky, Aaron J.; Brodie, Jean P.; Strader, Jay; Janz, Joachim; Usher, Christopher; Spitler, Lee R.; Bellstedt, Sabine; Ferré-Mateu, Anna

    2017-07-01

    We use globular cluster kinematics data, primarily from the SAGES Legacy Unifying Globulars and GalaxieS (SLUGGS) survey, to measure the dark matter fraction (fDM) and the average dark matter density () within the inner 5 effective radii (Re) for 32 nearby early-type galaxies (ETGs) with stellar mass log (M*/M⊙) ranging from 10.1 to 11.8. We compare our results with a simple galaxy model based on scaling relations as well as with cosmological hydrodynamical simulations where the dark matter profile has been modified through various physical processes. We find a high fDM (≥0.6) within 5 Re in most of our sample, which we interpret as a signature of a late mass assembly history that is largely devoid of gas-rich major mergers. However, around log (M*/M⊙) ˜ 11, there is a wide range of fDM which may be challenging to explain with any single cosmological model. We find tentative evidence that lenticulars (S0s), unlike ellipticals, have mass distributions that are similar to spiral galaxies, with decreasing fDM within 5 Re as galaxy luminosity increases. However, we do not find any difference between the of S0s and ellipticals in our sample, despite the differences in their stellar populations. We have also used to infer the epoch of halo assembly (z ˜ 2-4). By comparing the age of their central stars with the inferred epoch of halo formation, we are able to gain more insight into their mass assembly histories. Our results suggest a fundamental difference in the dominant late-phase mass assembly channel between lenticulars and elliptical galaxies.

  19. The DES Bright Arcs Survey: Hundreds of Candidate Strongly Lensed Galaxy Systems from the Dark Energy Survey Science Verification and Year 1 Observations

    Energy Technology Data Exchange (ETDEWEB)

    Diehl, H. T.; Buckley-Geer, E. J.; Lindgren, K. A.; Nord, B.; Gaitsch, H.; Gaitsch, S.; Lin, H.; Allam, S.; Collett, T. E.; Furlanetto, C.; Gill, M. S. S.; More, A.; Nightingale, J.; Odden, C.; Pellico, A.; Tucker, D. L.; Costa, L. N. da; Neto, A. Fausti; Kuropatkin, N.; Soares-Santos, M.; Welch, B.; Zhang, Y.; Frieman, J. A.; Abdalla, F. B.; Annis, J.; Benoit-Lévy, A.; Bertin, E.; Brooks, D.; Burke, D. L.; Rosell, A. Carnero; Kind, M. Carrasco; Carretero, J.; Cunha, C. E.; D’Andrea, C. B.; Desai, S.; Dietrich, J. P.; Drlica-Wagner, A.; Evrard, A. E.; Finley, D. A.; Flaugher, B.; García-Bellido, J.; Gerdes, D. W.; Goldstein, D. A.; Gruen, D.; Gruendl, R. A.; Gschwend, J.; Gutierrez, G.; James, D. J.; Kuehn, K.; Kuhlmann, S.; Lahav, O.; Li, T. S.; Lima, M.; Maia, M. A. G.; Marshall, J. L.; Menanteau, F.; Miquel, R.; Nichol, R. C.; Nugent, P.; Ogando, R. L. C.; Plazas, A. A.; Reil, K.; Romer, A. K.; Sako, M.; Sanchez, E.; Santiago, B.; Scarpine, V.; Schindler, R.; Schubnell, M.; Sevilla-Noarbe, I.; Sheldon, E.; Smith, M.; Sobreira, F.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; Walker, A. R.

    2017-09-01

    We report the results of our searches for strong gravitational lens systems in the Dark Energy Survey (DES) Science Verication and Year 1 observations. The Science Verication data spans approximately 250 sq. deg. with median i

  20. Legacy question

    International Nuclear Information System (INIS)

    Healy, J.W.

    1977-01-01

    The legacy question discussed refers to the definition of appropriate actions in this generation to provide a world that will allow future generations to use the earth without excessive limitations caused by our use and disposal of potentially hazardous materials

  1. Enhancing the Legacy of Spitzer and Herschel with the MOSFIRE Deep Evolution Field Survey

    Science.gov (United States)

    Reddy, Naveen

    The next frontier for comprehensive galaxy surveys is the epoch at z~1.5-3.5, the peak of star formation and black hole activity. Despite the new windows that Spitzer and Herschel have opened up into the stellar and dust emission of distant galaxies and AGN during this key epoch, these studies have been limited by the lack of spectroscopic redshifts and the unknown physical conditions (e.g., metallicities, ionization) within the targeted galaxies. To realize the full potential of Spitzer and Herschel, we require a large spectroscopic survey that will: (a) efficiently assemble spectroscopic redshifts for large samples of galaxies at z=1.4-3.8; (b) yield the physical conditions, including the ionization and metallicities of these galaxies; and (c) easily obtain spectroscopic redshifts even for very dusty/confused galaxies. To this end, our team has been allocated a large program of 47 Keck nights with the multi-object near-IR spectrograph MOSFIRE to carry out the MOSFIRE Deep Evolution Field Survey (MOSDEF) in three of the Hubble CANDELS fields. MOSDEF will obtain rest-optical spectra of ~1500 galaxies at redshifts z=1.4-3.8, targeting many of the optical nebular emission lines and continuum features (e.g., [OII], [OIII], H-beta, H-alpha, [NII], [SII], 4000 Angstrom break, Ca H and K, and Mbg) that until now have been inaccessible for large samples of distant galaxies, but which are routinely used to measure the SFRs, dust attenuation, metal and gas content, and ionization and dynamical properties in nearby galaxies. MOSDEF spectroscopy provides a critical supporting role for the analysis of Spitzer and Herschel observations of distant galaxies. With this transformative dataset, we will perform the following analyses. First, we will use Spitzer and Herschel imaging, aided with spectroscopic redshifts from MOSDEF, to construct individual and mean dust SEDs for galaxies at redshifts 1.4formation and destruction processes. Our study will greatly enhance the scientific

  2. Comparison of the linear bias models in the light of the Dark Energy Survey

    Science.gov (United States)

    Papageorgiou, A.; Basilakos, S.; Plionis, M.

    2018-02-01

    The evolution of the linear and scale independent bias, based on the most popular dark matter bias models within the ΛCDM cosmology, is confronted to that of the Dark Energy Survey (DES) Luminous Red Galaxies (LRGs). Applying a χ2 minimization procedure between models and data we find that all the considered linear bias models reproduce well the LRG bias data. The differences among the bias models are absorbed in the predicted mass of the dark-matter halo in which LRGs live and which ranges between ˜6 × 1012h-1M⊙ and 1.4 × 1013h-1M⊙, for the different bias models. Similar results, reaching however a maximum value of ˜2 × 1013h-1M⊙, are found by confronting the SDSS (2SLAQ) Large Red Galaxies clustering with theoretical clustering models, which also include the evolution of bias. This later analysis also provides a value of Ωm = 0.30 ± 0.01, which is in excellent agreement with recent joint analyses of different cosmological probes and the reanalysis of the Planck data.

  3. Wide-Field Lensing Mass Maps from Dark Energy Survey Science Verification Data.

    Science.gov (United States)

    Chang, C; Vikram, V; Jain, B; Bacon, D; Amara, A; Becker, M R; Bernstein, G; Bonnett, C; Bridle, S; Brout, D; Busha, M; Frieman, J; Gaztanaga, E; Hartley, W; Jarvis, M; Kacprzak, T; Kovács, A; Lahav, O; Lin, H; Melchior, P; Peiris, H; Rozo, E; Rykoff, E; Sánchez, C; Sheldon, E; Troxel, M A; Wechsler, R; Zuntz, J; Abbott, T; Abdalla, F B; Allam, S; Annis, J; Bauer, A H; Benoit-Lévy, A; Brooks, D; Buckley-Geer, E; Burke, D L; Capozzi, D; Carnero Rosell, A; Carrasco Kind, M; Castander, F J; Crocce, M; D'Andrea, C B; Desai, S; Diehl, H T; Dietrich, J P; Doel, P; Eifler, T F; Evrard, A E; Fausti Neto, A; Flaugher, B; Fosalba, P; Gruen, D; Gruendl, R A; Gutierrez, G; Honscheid, K; James, D; Kent, S; Kuehn, K; Kuropatkin, N; Maia, M A G; March, M; Martini, P; Merritt, K W; Miller, C J; Miquel, R; Neilsen, E; Nichol, R C; Ogando, R; Plazas, A A; Romer, A K; Roodman, A; Sako, M; Sanchez, E; Sevilla, I; Smith, R C; Soares-Santos, M; Sobreira, F; Suchyta, E; Tarle, G; Thaler, J; Thomas, D; Tucker, D; Walker, A R

    2015-07-31

    We present a mass map reconstructed from weak gravitational lensing shear measurements over 139  deg2 from the Dark Energy Survey science verification data. The mass map probes both luminous and dark matter, thus providing a tool for studying cosmology. We find good agreement between the mass map and the distribution of massive galaxy clusters identified using a red-sequence cluster finder. Potential candidates for superclusters and voids are identified using these maps. We measure the cross-correlation between the mass map and a magnitude-limited foreground galaxy sample and find a detection at the 6.8σ level with 20 arc min smoothing. These measurements are consistent with simulated galaxy catalogs based on N-body simulations from a cold dark matter model with a cosmological constant. This suggests low systematics uncertainties in the map. We summarize our key findings in this Letter; the detailed methodology and tests for systematics are presented in a companion paper.

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

    International Nuclear Information System (INIS)

    Smail, Ian; Swinbank, A. M.; Danielson, A. L. R.; Edge, A. C.; Simpson, J. M.; Geach, J. E.; Tadaki, K.; Arumugam, V.; Dunlop, J. S.; Ivison, R. J.; Hartley, W.; Almaini, O.; Conselice, C.; Bremer, M. N.; Chapin, E.; Chapman, S. C.; Scott, D.; Simpson, C. J.; Karim, A.; Kodama, T.

    2014-01-01

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

  5. THE SPACE DENSITY EVOLUTION OF WET AND DRY MERGERS IN THE CANADA-FRANCE-HAWAII TELESCOPE LEGACY SURVEY

    International Nuclear Information System (INIS)

    Chou, Richard C. Y.; Abraham, Roberto G.; Bridge, Carrie R.

    2011-01-01

    We analyze 1298 merging galaxies with redshifts up to z = 0.7 from the Canada-France-Hawaii Telescope Legacy Survey, taken from the catalog presented in the work of Bridge et al. By analyzing the internal colors of these systems, we show that the so-called wet and dry mergers evolve in different senses, and quantify the space densities of these systems. The local space density of wet mergers is essentially identical to the local space density of dry mergers. The evolution in the total merger rate is modest out to z ∼ 0.7, although the wet and dry populations have different evolutionary trends. At higher redshifts, dry mergers make a smaller contribution to the total merging galaxy population, but this is offset by a roughly equivalent increase in the contribution from wet mergers. By comparing the mass density function of early-type galaxies to the corresponding mass density function for merging systems, we show that not all the major mergers with the highest masses (M stellar >10 11 M sun ) will end up with the most massive early-type galaxies, unless the merging timescale is dramatically longer than that usually assumed. On the other hand, the usually assumed merging timescale of ∼0.5-1 Gyr is quite consistent with the data if we suppose that only less massive early-type galaxies form via mergers. Since low-intermediate-mass ellipticals are 10-100 times more common than their most massive counterparts, the hierarchical explanation for the origin of early-type galaxies may be correct for the vast majority of early types, even if incorrect for the most massive ones.

  6. The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters - XII. The RGB bumps of multiple stellar populations

    Science.gov (United States)

    Lagioia, E. P.; Milone, A. P.; Marino, A. F.; Cassisi, S.; Aparicio, A. J.; Piotto, G.; Anderson, J.; Barbuy, B.; Bedin, L. R.; Bellini, A.; Brown, T.; D'Antona, F.; Nardiello, D.; Ortolani, S.; Pietrinferni, A.; Renzini, A.; Salaris, M.; Sarajedini, A.; van der Marel, R.; Vesperini, E.

    2018-04-01

    The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters is providing a major breakthrough in our knowledge of globular clusters (GCs) and their stellar populations. Among the main results, we discovered that all the studied GCs host two main discrete groups consisting of first generation (1G) and second generation (2G) stars. We exploit the multiwavelength photometry from this project to investigate, for the first time, the Red Giant Branch Bump (RGBB) of the two generations in a large sample of GCs. We identified, with high statistical significance, the RGBB of 1G and 2G stars in 26 GCs and found that their magnitude separation as a function of the filter wavelength follows comparable trends. The comparison of observations to synthetic spectra reveals that the RGBB luminosity depends on the stellar chemical composition and that the 2G RGBB is consistent with stars enhanced in He and N and depleted in C and O with respect to 1G stars. For metal-poor GCs the 1G and 2G RGBB relative luminosity in optical bands mostly depends on helium content, Y. We used the RGBB observations in F606W and F814W bands to infer the relative helium abundance of 1G and 2G stars in 18 GCs, finding an average helium enhancement ΔY = 0.011 ± 0.002 of 2G stars with respect to 1G stars. This is the first determination of the average difference in helium abundance of multiple populations in a large number of clusters and provides a lower limit to the maximum internal variation of helium in GCs.

  7. The IAC Stripe 82 Legacy Project: a wide-area survey for faint surface brightness astronomy

    Science.gov (United States)

    Fliri, Jürgen; Trujillo, Ignacio

    2016-02-01

    We present new deep co-adds of data taken within Stripe 82 of the Sloan Digital Sky Survey (SDSS), especially stacked to reach the faintest surface brightness limits of this data set. Stripe 82 covers 275 ° ^2 within -50° ≤ RA ≤ +60° and -1.25° ≤ Dec. ≤ +1.25°. We discuss the steps of our reduction which puts special emphasis on preserving the characteristics of the background (sky + diffuse light) in the input images using a non-aggressive sky subtraction strategy. Our reduction reaches a limit of ˜28.5 mag arcsec-2 (3σ, 10 × 10 arcsec2) in the r band. The effective surface brightness limit (50 per cent completeness for exponential light distribution) lies at ˜ 25.5 mag arcsec-2. For point sources, we reach 50 per cent completeness limits (3σ level) of (24.2, 25.2, 24.7, 24.3, 23.0) mag in (u, g, r, I, z). This is between 1.7 and 2.0 mag deeper than the single-epoch SDSS releases. The co-adds show point spread functions (PSFs) with median full width at half-maximum values ranging from 1 arcsec in I and z to 1.3 arcsec in the u band. The imaging data are made publicly available at http://www.iac.es/proyecto/stripe82. The release includes deep co-adds and representations of the PSF for each field. Additionally, we provide object catalogues with stars and galaxies confidently separated until g ˜ 23 mag. The IAC Stripe 82 co-adds offer a rather unique possibility to study the low surface brightness Universe, exemplified by the discovery of stellar streams around NGC 0426 and NGC 0936. We also discuss further science cases like stellar haloes and disc truncations, low surface brightness galaxies, the intracluster light in galaxy clusters and the diffuse emission of Galactic dust known as Galactic Cirrus.

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

    Science.gov (United States)

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

    2017-04-01

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

  9. The Transition to Large-scale Cosmic Homogeneity in the WiggleZ Dark Energy Survey

    Science.gov (United States)

    Scrimgeour, Morag; Davis, T.; Blake, C.; James, B.; Poole, G. B.; Staveley-Smith, L.; Dark Energy Survey, WiggleZ

    2013-01-01

    The most fundamental assumption of the standard cosmological model (ΛCDM) is that the universe is homogeneous on large scales. This is clearly not true on small scales, where clusters and voids exist, and some studies seem to suggest that galaxies follow a fractal distribution up to very large scales 200 h-1 Mpc or more), whereas the ΛCDM model predicts transition to homogeneity at scales of ~100 h-1 Mpc. Any cosmological measurements made below the scale of homogeneity (such as the power spectrum) could be misleading, so it is crucial to measure the scale of homogeneity in the Universe. We have used the WiggleZ Dark Energy Survey to make the largest volume measurement to date of the transition to homogeneity in the galaxy distribution. WiggleZ is a UV-selected spectroscopic survey of ~200,000 luminous blue galaxies up to z=1, made with the Anglo-Australian Telescope. We have corrected for survey incompleteness using random catalogues that account for the various survey selection criteria, and tested the robustness of our results using a suite of fractal mock catalogues. The large volume and depth of WiggleZ allows us to probe the transition of the galaxy distribution to homogeneity on large scales and over several epochs, and see if this is consistent with a ΛCDM prediction.

  10. Internal Stellar Kinematics of M32 from the SPLASH Survey: Dark Halo Constraints

    Science.gov (United States)

    Howley, K. M.; Guhathakurta, P.; van der Marel, R.; Geha, M.; Kalirai, J.; Yniguez, B.; Kirby, E.; Cuillandre, J.-C.; Gilbert, K.

    2013-03-01

    As part of the SPLASH survey of the Andromeda (M31) system, we have obtained Keck/DEIMOS spectra of the compact elliptical (cE) satellite M32. This is the first resolved-star kinematical study of any cE galaxy. In contrast to most previous kinematical studies that extended out to r information to account statistically for M31 contamination. The rotation curve and velocity dispersion profile extend well beyond the radius (r ~ 150'') where the isophotes are distorted. Unlike NGC 205, another close dwarf companion of M31, M32's kinematics appear regular and symmetric and do not show obvious sharp gradients across the region of isophotal elongation and twists. We interpret M31's kinematics using three-integral axisymmetric dynamical equilibrium models constructed using Schwarzschild's orbit superposition technique. Models with a constant mass-to-light ratio can fit the data remarkably well. However, since such a model requires an increasing tangential anisotropy with radius, invoking the presence of an extended dark halo may be more plausible. Such an extended dark halo is definitely required to bind a half-dozen fast-moving stars observed at the largest radii, but these stars may not be an equilibrium component of M32. Data herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

  11. OzDES multifibre spectroscopy for the Dark Energy Survey: first-year operation and results

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Fang; Lidman, C.; Davis, T. M.; Childress, M.; Abdalla, F. B.; Banerji, M.; Buckley-Geer, E.; Carnero Rosell, A.; Carollo, D.; Castander, F. J.; D' Andrea, C. B.; Diehl, H. T.; Cunha, C. E.; Foley, R. J.; Frieman, J.; Glazebrook, K.; Gschwend, J.; Hinton, S.; Jouvel, S.; Kessler, R.; Kim, A. G.; King, A. L.; Kuehn, K.; Kuhlmann, S.; Lewis, G. F.; Lin, H.; Martini, P.; McMahon, R. G.; Mould, J.; Nichol, R. C.; Norris, R. P.; O' Neill, C. R.; Ostrovski, F.; Papadopoulos, A.; Parkinson, D.; Reed, S.; Romer, A. K.; Rooney, P. J.; Rozo, E.; Rykoff, E. S.; Sako, M.; Scalzo, R.; Schmidt, B. P.; Scolnic, D.; Seymour, N.; Sharp, R.; Sobreira, F.; Sullivan, M.; Thomas, R. C.; Tucker, D.; Uddin, S. A.; Wechsler, R. H.; Wester, W.; Wilcox, H.; Zhang, B.; Abbott, T.; Allam, S.; Bauer, A. H.; Benoit-L?vy, A.; Bertin, E.; Brooks, D.; Burke, D. L.; Carrasco Kind, M.; Covarrubias, R.; Crocce, M.; da Costa, L. N.; DePoy, D. L.; Desai, S.; Doel, P.; Eifler, T. F.; Evrard, A. E.; Fausti Neto, A.; Flaugher, B.; Fosalba, P.; Gaztanaga, E.; Gerdes, D.; Gruen, D.; Gruendl, R. A.; Honscheid, K.; James, D.; Kuropatkin, N.; Lahav, O.; Li, T. S.; Maia, M. A. G.; Makler, M.; Marshall, J.; Miller, C. J.; Miquel, R.; Ogando, R.; Plazas, A. A.; Roodman, A.; Sanchez, E.; Scarpine, V.; Schubnell, M.; Sevilla-Noarbe, I.; Smith, R. C.; Soares-Santos, M.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thaler, J.; Walker, A. R.

    2015-07-29

    We present results for the first three years of OzDES, a six-year program to obtain redshifts for objects in the Dark Energy Survey (DES) supernova fields using the 2dF fibre positioner and AAOmega spectrograph on the Anglo-Australian Telescope. OzDES is a multi-object spectroscopic survey targeting multiple types of targets at multiple epochs over a multi-year baseline, and is one of the first multi-object spectroscopic surveys to dynamically include transients into the target list soon after their discovery. At the end of three years, OzDES has spectroscopically confirmed almost 100 supernovae, and has measured redshifts for 17,000 objects, including the redshifts of 2,566 supernova hosts. We examine how our ability to measure redshifts for targets of various types depends on signal-to-noise, magnitude, and exposure time, finding that our redshift success rate increases significantly at a signal-to-noise of 2 to 3 per 1-A° ngstrom bin. We also find that the change in signal-to-noise with exposure time closely matches the Poisson limit for stacked exposures as long as 10 hours.We use these results to predict the redshift yield of the full OzDES survey, as well as the potential yields of future surveys on other facilities such as 4MOST, PFS, and MSE. This work marks the first OzDES data release, comprising 15,327 redshifts. OzDES is on target to obtain over 30,000 redshifts over the six-year duration of the survey, including a yield of approximately 5,700 supernova host-galaxy redshifts.

  12. CO survey of the dark nebulae in Perseus, Taurus, and Auriga

    International Nuclear Information System (INIS)

    Ungerechts, H.; Thaddeus, P.

    1987-01-01

    A new SIS receiver with extremely low noise temperature, used on the Columbia 1.2-m telescope has permitted mapping CO rapidly with full sampling. Results are presented of a survey for which the angular resolution of the telescope was reduced to 0.5 deg, allowing the observations for the complete region of 750 square degrees to be finished within four months, while retaining sufficient resolution to see significant substructure. Most positions with emission are in the Taurus-Auriga dark nebulae, a cloud associated with IC 348 and NGC 1333, and a cloud associated with the California nebula (NGC 1499) and NGC 1579, which overlaps the northern Taurus-Auriga nebulae but is separated from them in velocity. Also seen were several small clouds at Galactic latitude -25 deg to -35 deg southwest of the Taurus clouds, and the L1558 and L1551 clouds in the south. 89 references

  13. Chemical Abundance Measurements of Ultra-Faint Dwarf Galaxies Discovered by the Dark Energy Survey

    Science.gov (United States)

    Nagasawa, Daniel; Marshall, Jennifer L.; Simon, Joshua D.; Hansen, Terese; Li, Ting; Bernstein, Rebecca; Balbinot, Eduardo; Drlica-Wagner, Alex; Pace, Andrew; Strigari, Louis; Pellegrino, Craig; DePoy, Darren L.; Suntzeff, Nicholas; Bechtol, Keith; Dark Energy Suvey

    2018-01-01

    We present chemical abundance analysis results derived from high-resolution spectroscopy of ultra-faint dwarfs discovered by the Dark Energy Survey. Ultra-faint dwarf galaxies preserve a fossil record of the chemical abundance patterns imprinted by the first stars in the Universe. High-resolution spectroscopic observations of member stars in several recently discovered Milky Way satellites reveal a range of abundance patterns among ultra-faint dwarfs suggesting that star formation processes in the early Universe were quite diverse. The chemical content provides a glimpse not only of the varied nucleosynthetic processes and chemical history of the dwarfs themselves, but also the environment in which they were formed. We present the chemical abundance analysis of these objects and discuss possible explanations for the observed abundance patterns.

  14. Dark Energy Survey Year 1 Results: The Photometric Data Set for Cosmology

    Science.gov (United States)

    Drlica-Wagner, A.; Sevilla-Noarbe, I.; Rykoff, E. S.; Gruendl, R. A.; Yanny, B.; Tucker, D. L.; Hoyle, B.; Carnero Rosell, A.; Bernstein, G. M.; Bechtol, K.; Becker, M. R.; Benoit-Lévy, A.; Bertin, E.; Carrasco Kind, M.; Davis, C.; de Vicente, J.; Diehl, H. T.; Gruen, D.; Hartley, W. G.; Leistedt, B.; Li, T. S.; Marshall, J. L.; Neilsen, E.; Rau, M. M.; Sheldon, E.; Smith, J.; Troxel, M. A.; Wyatt, S.; Zhang, Y.; Abbott, T. M. C.; Abdalla, F. B.; Allam, S.; Banerji, M.; Brooks, D.; Buckley-Geer, E.; Burke, D. L.; Capozzi, D.; Carretero, J.; Cunha, C. E.; D’Andrea, C. B.; da Costa, L. N.; DePoy, D. L.; Desai, S.; Dietrich, J. P.; Doel, P.; Evrard, A. E.; Fausti Neto, A.; Flaugher, B.; Fosalba, P.; Frieman, J.; García-Bellido, J.; Gerdes, D. W.; Giannantonio, T.; Gschwend, J.; Gutierrez, G.; Honscheid, K.; James, D. J.; Jeltema, T.; Kuehn, K.; Kuhlmann, S.; Kuropatkin, N.; Lahav, O.; Lima, M.; Lin, H.; Maia, M. A. G.; Martini, P.; McMahon, R. G.; Melchior, P.; Menanteau, F.; Miquel, R.; Nichol, R. C.; Ogando, R. L. C.; Plazas, A. A.; Romer, A. K.; Roodman, A.; Sanchez, E.; Scarpine, V.; Schindler, R.; Schubnell, M.; Smith, M.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Suchyta, E.; Tarle, G.; Vikram, V.; Walker, A. R.; Wechsler, R. H.; Zuntz, J.; DES Collaboration

    2018-04-01

    We describe the creation, content, and validation of the Dark Energy Survey (DES) internal year-one cosmology data set, Y1A1 GOLD, in support of upcoming cosmological analyses. The Y1A1 GOLD data set is assembled from multiple epochs of DES imaging and consists of calibrated photometric zero-points, object catalogs, and ancillary data products—e.g., maps of survey depth and observing conditions, star–galaxy classification, and photometric redshift estimates—that are necessary for accurate cosmological analyses. The Y1A1 GOLD wide-area object catalog consists of ∼ 137 million objects detected in co-added images covering ∼ 1800 {\\deg }2 in the DES grizY filters. The 10σ limiting magnitude for galaxies is g=23.4, r=23.2, i=22.5, z=21.8, and Y=20.1. Photometric calibration of Y1A1 GOLD was performed by combining nightly zero-point solutions with stellar locus regression, and the absolute calibration accuracy is better than 2% over the survey area. DES Y1A1 GOLD is the largest photometric data set at the achieved depth to date, enabling precise measurements of cosmic acceleration at z ≲ 1.

  15. Debiasing the Dark Energy Survey's Search for Trans-Neptunian Objects

    Science.gov (United States)

    Napier, Kevin; Gerdes, David

    2018-01-01

    The Dark Energy Survey (DES) is rich in transient detections of trans-Neptunian objects (TNOs). This has resulted in many newly detected TNOs. It is important to be mindful that astronomical surveys are intrinsically biased in their detections. Understanding a survey’s bias is necessary to understand the significance of any clustering in the orbital parameters of our detections. To quantify this bias, we examine the DES’s selection function for the detection of TNOs. To do so, we developed a survey simulator in Python. We generate clones of known TNOs with uniformly varied argument of perihelion, longitude of ascending node, and mean anomaly. We test the detectability of each clone based on the pointing location and limiting magnitude of each exposure in DES. Our preliminary results show that our simulator is functional. However, we do not yet have any conclusions about the DES’s bias, as we have not yet run the simulator on the entirety of DES for all of our TNOs.

  16. The WiggleZ Dark Energy Survey: final data release and the metallicity of UV-luminous galaxies

    Science.gov (United States)

    Drinkwater, Michael J.; Byrne, Zachary J.; Blake, Chris; Glazebrook, Karl; Brough, Sarah; Colless, Matthew; Couch, Warrick; Croton, Darren J.; Croom, Scott M.; Davis, Tamara M.; Forster, Karl; Gilbank, David; Hinton, Samuel R.; Jelliffe, Ben; Jurek, Russell J.; Li, I.-hui; Martin, D. Christopher; Pimbblet, Kevin; Poole, Gregory B.; Pracy, Michael; Sharp, Rob; Smillie, Jon; Spolaor, Max; Wisnioski, Emily; Woods, David; Wyder, Ted K.; Yee, Howard K. C.

    2018-03-01

    The WiggleZ Dark Energy Survey measured the redshifts of over 200 000 ultraviolet (UV)-selected (NUV UV-luminous Lyman-break galaxies by stacking the spectra in bins of luminosity, redshift, and stellar mass. The most luminous (-25 magUV-luminous WiggleZ galaxies.

  17. Star/galaxy separation at faint magnitudes: application to a simulated Dark Energy Survey

    Energy Technology Data Exchange (ETDEWEB)

    Soumagnac, M. T.; Abdalla, F. B.; Lahav, O.; Kirk, D.; Sevilla, I.; Bertin, E.; Rowe, B. T. P.; Annis, J.; Busha, M. T.; Da Costa, L. N.; Frieman, J. A.; Gaztanaga, E.; Jarvis, M.; Lin, H.; Percival, W. J.; Santiago, B. X.; Sabiu, C. G.; Wechsler, R. H.; Wolz, L.; Yanny, B.

    2015-04-14

    We address the problem of separating stars from galaxies in future large photometric surveys. We focus our analysis on simulations of the Dark Energy Survey (DES). In the first part of the paper, we derive the science requirements on star/galaxy separation, for measurement of the cosmological parameters with the gravitational weak lensing and large-scale structure probes. These requirements are dictated by the need to control both the statistical and systematic errors on the cosmological parameters, and by point spread function calibration. We formulate the requirements in terms of the completeness and purity provided by a given star/galaxy classifier. In order to achieve these requirements at faint magnitudes, we propose a new method for star/galaxy separation in the second part of the paper. We first use principal component analysis to outline the correlations between the objects parameters and extract from it the most relevant information. We then use the reduced set of parameters as input to an Artificial Neural Network. This multiparameter approach improves upon purely morphometric classifiers (such as the classifier implemented in SExtractor), especially at faint magnitudes: it increases the purity by up to 20 per cent for stars and by up to 12 per cent for galaxies, at i-magnitude fainter than 23.

  18. Dark Energy Survey Year 1 Results: galaxy mock catalogues for BAO

    Energy Technology Data Exchange (ETDEWEB)

    Avila, S.; et al.

    2017-12-17

    Mock catalogues are a crucial tool in the analysis of galaxy surveys data, both for the accurate computation of covariance matrices, and for the optimisation of analysis methodology and validation of data sets. In this paper, we present a set of 1800 galaxy mock catalogues designed to match the Dark Energy Survey Year-1 BAO sample (Crocce et al. 2017) in abundance, observational volume, redshift distribution and uncertainty, and redshift dependent clustering. The simulated samples were built upon HALOGEN (Avila et al. 2015) halo catalogues, based on a $2LPT$ density field with an exponential bias. For each of them, a lightcone is constructed by the superposition of snapshots in the redshift range $0.45

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

    Science.gov (United States)

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

    2015-05-01

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

  20. Gas-rich Galaxies in the Arecibo Legacy Fast ALFA Survey (ALFALFA) -- From HI Dwarfs to Giants

    Science.gov (United States)

    Huang, Shan

    2013-01-01

    Making use of HI 21 cm line measurements from the ALFALFA survey (α.40) and photometry from the SDSS and GALEX, we investigate the global scaling relations linking stars and gas for 9417 common galaxies (α.40-SDSS-GALEX). Stellar masses (M*) and SFRs are derived from fitting the UV-optical SEDs. 96% of the α.40-SDSS-GALEX galaxies belong to the blue cloud, with the average gas fraction MHI/M* > 1.5. A transition in star formation (SF) properties is found whereby below M* > 109.5M⊙, the slope of the SF sequence changes, the dispersion in the specific star formation rate (SSFR) distribution increases, and the star formation efficiency (SFE) mildly increases with M*. The evolutionary track in the SSFR-M* diagram, as well as that in the CMD, is linked to the HI content; below this transition mass, the SF is regulated strongly by the HI. Comparison of HI and optically selected samples shows that the HI-selected population is less evolved and has overall higher SFR and SSFR at a given M*, but lower SFE and extinction, suggesting either that a bottleneck exists in the HI-to-H2 conversion, or that the very HI-dominated galaxies obey an low efficiency SF law. We show that for a given M*, high gas fraction galaxies reside preferentially in dark matter halos with high spin parameters. In addition, we closely studied 229 low MHI ALFALFA dwarfs with reprocessed GALEX photometry. Many of them are currently undergoing active SF, relative to the past-averaged level, so that the widely used standard formulae calibrated for a continuous SF history systematically overestimate the M* and SFR. Currently, we are gathering multi-wavelength data for the High HI Mass, HI-rich (HIghMass) galaxies identified by the ALFALFA (MHI>1010M⊙ and gas fraction more than 1σ above the mean given their M*). They may be in an arrested stage of evolution, or their huge HI disks may reflect recent baryon accretion. Most of the HIghMass galaxies exhibit strong color gradient and have higher Hα EWs

  1. Mapping extragalactic dark matter annihilation with galaxy surveys: A systematic study of stacked group searches

    Science.gov (United States)

    Lisanti, Mariangela; Mishra-Sharma, Siddharth; Rodd, Nicholas L.; Safdi, Benjamin R.; Wechsler, Risa H.

    2018-03-01

    Dark matter in the halos surrounding galaxy groups and clusters can annihilate to high-energy photons. Recent advancements in the construction of galaxy group catalogs provide many thousands of potential extragalactic targets for dark matter. In this paper, we outline a procedure to infer the dark matter signal associated with a given galaxy group. Applying this procedure to a catalog of sources, one can create a full-sky map of the brightest extragalactic dark matter targets in the nearby Universe (z ≲0.03 ), supplementing sources of dark matter annihilation from within the local group. As with searches for dark matter in dwarf galaxies, these extragalactic targets can be stacked together to enhance the signals associated with dark matter. We validate this procedure on mock Fermi gamma-ray data sets using a galaxy catalog constructed from the DarkSky N -body cosmological simulation and demonstrate that the limits are robust, at O (1 ) levels, to systematic uncertainties on halo mass and concentration. We also quantify other sources of systematic uncertainty arising from the analysis and modeling assumptions. Our results suggest that a stacking analysis using galaxy group catalogs provides a powerful opportunity to discover extragalactic dark matter and complements existing studies of Milky Way dwarf galaxies.

  2. Higgs-dilaton cosmology: An inflation-dark-energy connection and forecasts for future galaxy surveys

    Science.gov (United States)

    Casas, Santiago; Pauly, Martin; Rubio, Javier

    2018-02-01

    The Higgs-dilaton model is a scale-invariant extension of the Standard Model nonminimally coupled to gravity and containing just one additional degree of freedom on top of the Standard Model particle content. This minimalistic scenario predicts a set of measurable consistency relations between the inflationary observables and the dark-energy equation-of-state parameter. We present an alternative derivation of these consistency relations that highlights the connections and differences with the α -attractor scenario. We study how far these constraints allow one to distinguish the Higgs-dilaton model from Λ CDM and w CDM cosmologies. To this end we first analyze existing data sets using a Markov chain Monte Carlo approach. Second, we perform forecasts for future galaxy surveys using a Fisher matrix approach, both for galaxy clustering and weak lensing probes. Assuming that the best fit values in the different models remain comparable to the present ones, we show that both Euclid- and SKA2-like missions will be able to discriminate a Higgs-dilaton cosmology from Λ CDM and w CDM .

  3. Quasar Accretion Disk Sizes With Continuum Reverberation Mapping From the Dark Energy Survey

    Energy Technology Data Exchange (ETDEWEB)

    Mudd, D.; et al.

    2017-11-30

    We present accretion disk size measurements for 15 luminous quasars at $0.7 \\leq z \\leq 1.9$ derived from $griz$ light curves from the Dark Energy Survey. We measure the disk sizes with continuum reverberation mapping using two methods, both of which are derived from the expectation that accretion disks have a radial temperature gradient and the continuum emission at a given radius is well-described by a single blackbody. In the first method we measure the relative lags between the multiband light curves, which provides the relative time lag between shorter and longer wavelength variations. The second method fits the model parameters for the canonical Shakura-Sunyaev thin disk directly rather than solving for the individual time lags between the light curves. Our measurements demonstrate good agreement with the sizes predicted by this model for accretion rates between 0.3-1 times the Eddington rate. These results are also in reasonable agreement with disk size measurements from gravitational microlensing studies of strongly lensed quasars, as well as other photometric reverberation mapping results.

  4. Dark Energy Survey Year 1 Results: Cross-Correlation Redshifts - Methods and Systematics Characterization

    Science.gov (United States)

    Gatti, M.; Vielzeuf, P.; Davis, C.; Cawthon, R.; Rau, M. M.; DeRose, J.; De Vicente, J.; Alarcon, A.; Rozo, E.; Gaztanaga, E.; Hoyle, B.; Miquel, R.; Bernstein, G. M.; Bonnett, C.; Carnero Rosell, A.; Castander, F. J.; Chang, C.; da Costa, L. N.; Gruen, D.; Gschwend, J.; Hartley, W. G.; Lin, H.; MacCrann, N.; Maia, M. A. G.; Ogando, R. L. C.; Roodman, A.; Sevilla-Noarbe, I.; Troxel, M. A.; Wechsler, R. H.; Asorey, J.; Davis, T. M.; Glazebrook, K.; Hinton, S. R.; Lewis, G.; Lidman, C.; Macaulay, E.; Möller, A.; O'Neill, C. R.; Sommer, N. E.; Uddin, S. A.; Yuan, F.; Zhang, B.; Abbott, T. M. C.; Allam, S.; Annis, J.; Bechtol, K.; Brooks, D.; Burke, D. L.; Carollo, D.; Carrasco Kind, M.; Carretero, J.; Cunha, C. E.; D'Andrea, C. B.; DePoy, D. L.; Desai, S.; Eifler, T. F.; Evrard, A. E.; Flaugher, B.; Fosalba, P.; Frieman, J.; García-Bellido, J.; Gerdes, D. W.; Goldstein, D. A.; Gruendl, R. A.; Gutierrez, G.; Honscheid, K.; Hoormann, J. K.; Jain, B.; James, D. J.; Jarvis, M.; Jeltema, T.; Johnson, M. W. G.; Johnson, M. D.; Krause, E.; Kuehn, K.; Kuhlmann, S.; Kuropatkin, N.; Li, T. S.; Lima, M.; Marshall, J. L.; Melchior, P.; Menanteau, F.; Nichol, R. C.; Nord, B.; Plazas, A. A.; Reil, K.; Rykoff, E. S.; Sako, M.; Sanchez, E.; Scarpine, V.; Schubnell, M.; Sheldon, E.; Smith, M.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; Tucker, B. E.; Tucker, D. L.; Vikram, V.; Walker, A. R.; Weller, J.; Wester, W.; Wolf, R. C.

    2018-02-01

    We use numerical simulations to characterize the performance of a clustering-based method to calibrate photometric redshift biases. In particular, we cross-correlate the weak lensing (WL) source galaxies from the Dark Energy Survey Year 1 (DES Y1) sample with redMaGiC galaxies (luminous red galaxies with secure photometric redshifts) to estimate the redshift distribution of the former sample. The recovered redshift distributions are used to calibrate the photometric redshift bias of standard photo-z methods applied to the same source galaxy sample. We apply the method to two photo-z codes run in our simulated data: Bayesian Photometric Redshift (BPZ) and Directional Neighborhood Fitting (DNF). We characterize the systematic uncertainties of our calibration procedure, and find that these systematic uncertainties dominate our error budget. The dominant systematics are due to our assumption of unevolving bias and clustering across each redshift bin, and to differences between the shapes of the redshift distributions derived by clustering vs photo-z's. The systematic uncertainty in the mean redshift bias of the source galaxy sample is Δz ≲ 0.02, though the precise value depends on the redshift bin under consideration. We discuss possible ways to mitigate the impact of our dominant systematics in future analyses.

  5. Dark Energy Survey Year 1 Results: Galaxy Sample for BAO Measurement

    Energy Technology Data Exchange (ETDEWEB)

    Crocce, M.; et al.

    2017-12-17

    We define and characterise a sample of 1.3 million galaxies extracted from the first year of Dark Energy Survey data, optimised to measure Baryon Acoustic Oscillations in the presence of significant redshift uncertainties. The sample is dominated by luminous red galaxies located at redshifts $z \\gtrsim 0.6$. We define the exact selection using color and magnitude cuts that balance the need of high number densities and small photometric redshift uncertainties, using the corresponding forecasted BAO distance error as a figure-of-merit in the process. The typical photo-$z$ uncertainty varies from $2.3\\%$ to $3.6\\%$ (in units of 1+$z$) from $z=0.6$ to $1$, with number densities from $200$ to $130$ galaxies per deg$^2$ in tomographic bins of width $\\Delta z = 0.1$. Next we summarise the validation of the photometric redshift estimation. We characterise and mitigate observational systematics including stellar contamination, and show that the clustering on large scales is robust in front of those contaminants. We show that the clustering signal in the auto-correlations and cross-correlations is generally consistent with theoretical models, which serves as an additional test of the redshift distributions.

  6. Weak lensing magnification in the Dark Energy Survey Science Verification Data

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Fernandez, M.; et al.

    2016-11-30

    In this paper the effect of weak lensing magnification on galaxy number counts is studied by cross-correlating the positions of two galaxy samples, separated by redshift, using data from the Dark Energy Survey Science Verification dataset. The analysis is carried out for two photometrically-selected galaxy samples, with mean photometric redshifts in the $0.2 < z < 0.4$ and $0.7 < z < 1.0$ ranges, in the riz bands. A signal is detected with a $3.5\\sigma$ significance level in each of the bands tested, and is compatible with the magnification predicted by the $\\Lambda$CDM model. After an extensive analysis, it cannot be attributed to any known systematic effect. The detection of the magnification signal is robust to estimated uncertainties in the outlier rate of the pho- tometric redshifts, but this will be an important issue for use of photometric redshifts in magnification mesurements from larger samples. In addition to the detection of the magnification signal, a method to select the sample with the maximum signal-to-noise is proposed and validated with data.

  7. Dark Energy Survey Year 1 Results: Multi-Probe Methodology and Simulated Likelihood Analyses

    Energy Technology Data Exchange (ETDEWEB)

    Krause, E.; et al.

    2017-06-28

    We present the methodology for and detail the implementation of the Dark Energy Survey (DES) 3x2pt DES Year 1 (Y1) analysis, which combines configuration-space two-point statistics from three different cosmological probes: cosmic shear, galaxy-galaxy lensing, and galaxy clustering, using data from the first year of DES observations. We have developed two independent modeling pipelines and describe the code validation process. We derive expressions for analytical real-space multi-probe covariances, and describe their validation with numerical simulations. We stress-test the inference pipelines in simulated likelihood analyses that vary 6-7 cosmology parameters plus 20 nuisance parameters and precisely resemble the analysis to be presented in the DES 3x2pt analysis paper, using a variety of simulated input data vectors with varying assumptions. We find that any disagreement between pipelines leads to changes in assigned likelihood $\\Delta \\chi^2 \\le 0.045$ with respect to the statistical error of the DES Y1 data vector. We also find that angular binning and survey mask do not impact our analytic covariance at a significant level. We determine lower bounds on scales used for analysis of galaxy clustering (8 Mpc$~h^{-1}$) and galaxy-galaxy lensing (12 Mpc$~h^{-1}$) such that the impact of modeling uncertainties in the non-linear regime is well below statistical errors, and show that our analysis choices are robust against a variety of systematics. These tests demonstrate that we have a robust analysis pipeline that yields unbiased cosmological parameter inferences for the flagship 3x2pt DES Y1 analysis. We emphasize that the level of independent code development and subsequent code comparison as demonstrated in this paper is necessary to produce credible constraints from increasingly complex multi-probe analyses of current data.

  8. Combining Dark Energy Survey Science Verification data with near-infrared data from the ESO VISTA Hemisphere Survey

    Energy Technology Data Exchange (ETDEWEB)

    Banerji, M.; Jouvel, S.; Lin, H.; McMahon, R. G.; Lahav, O.; Castander, F. J.; Abdalla, F. B.; Bertin, E.; Bosman, S. E.; Carnero, A.; Kind, M. C.; da Costa, L. N.; Gerdes, D.; Gschwend, J.; Lima, M.; Maia, M. A. G.; Merson, A.; Miller, C.; Ogando, R.; Pellegrini, P.; Reed, S.; Saglia, R.; Sanchez, C.; Allam, S.; Annis, J.; Bernstein, G.; Bernstein, J.; Bernstein, R.; Capozzi, D.; Childress, M.; Cunha, C. E.; Davis, T. M.; DePoy, D. L.; Desai, S.; Diehl, H. T.; Doel, P.; Findlay, J.; Finley, D. A.; Flaugher, B.; Frieman, J.; Gaztanaga, E.; Glazebrook, K.; Gonzalez-Fernandez, C.; Gonzalez-Solares, E.; Honscheid, K.; Irwin, M. J.; Jarvis, M. J.; Kim, A.; Koposov, S.; Kuehn, K.; Kupcu-Yoldas, A.; Lagattuta, D.; Lewis, J. R.; Lidman, C.; Makler, M.; Marriner, J.; Marshall, J. L.; Miquel, R.; Mohr, J. J.; Neilsen, E.; Peoples, J.; Sako, M.; Sanchez, E.; Scarpine, V.; Schindler, R.; Schubnell, M.; Sevilla, I.; Sharp, R.; Soares-Santos, M.; Swanson, M. E. C.; Tarle, G.; Thaler, J.; Tucker, D.; Uddin, S. A.; Wechsler, R.; Wester, W.; Yuan, F.; Zuntz, J.

    2014-11-25

    We present the combination of optical data from the Science Verification phase of the Dark Energy Survey (DES) with near-infrared (NIR) data from the European Southern Observatory VISTA Hemisphere Survey (VHS). The deep optical detections from DES are used to extract fluxes and associated errors from the shallower VHS data. Joint seven-band (grizYJK) photometric catalogues are produced in a single 3 sq-deg dedicated camera field centred at 02h26m-04d36m where the availability of ancillary multiwavelength photometry and spectroscopy allows us to test the data quality. Dual photometry increases the number of DES galaxies with measured VHS fluxes by a factor of ~4.5 relative to a simple catalogue level matching and results in a ~1.5 mag increase in the 80 per cent completeness limit of the NIR data. Almost 70 per cent of DES sources have useful NIR flux measurements in this initial catalogue. Photometric redshifts are estimated for a subset of galaxies with spectroscopic redshifts and initial results, although currently limited by small number statistics, indicate that the VHS data can help reduce the photometric redshift scatter at both z < 0.5 and z > 1. We present example DES+VHS colour selection criteria for high-redshift luminous red galaxies (LRGs) at z ~ 0.7 as well as luminous quasars. Using spectroscopic observations in this field we show that the additional VHS fluxes enable a cleaner selection of both populations with <10 per cent contamination from galactic stars in the case of spectroscopically confirmed quasars and <0.5 per cent contamination from galactic stars in the case of spectroscopically confirmed LRGs. The combined DES+VHS data set, which will eventually cover almost 5000 sq-deg, will therefore enable a range of new science and be ideally suited for target selection for future wide-field spectroscopic surveys.

  9. THE DIFFERENCE IMAGING PIPELINE FOR THE TRANSIENT SEARCH IN THE DARK ENERGY SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Kessler, R.; Marriner, J.; Childress, M.; Covarrubias, R.; D’Andrea, C. B.; Finley, D. A.; Fischer, J.; Foley, R. J.; Goldstein, D.; Gupta, R. R.; Kuehn, K.; Marcha, M.; Nichol, R. C.; Papadopoulos, A.; Sako, M.; Scolnic, D.; Smith, M.; Sullivan, M.; Wester, W.; Yuan, F.; Abbott, T.; Abdalla, F. B.; Allam, S.; Benoit-Lévy, A.; Bernstein, G. M.; Bertin, E.; Brooks, D.; Rosell, A. Carnero; Kind, M. Carrasco; Castander, F. J.; Crocce, M.; Costa, L. N. da; Desai, S.; Diehl, H. T.; Eifler, T. F.; Neto, A. Fausti; Flaugher, B.; Frieman, J.; Gerdes, D. W.; Gruen, D.; Gruendl, R. A.; Honscheid, K.; James, D. J.; Kuropatkin, N.; Li, T. S.; Maia, M. A. G.; Marshall, J. L.; Martini, P.; Miller, C. J.; Miquel, R.; Nord, B.; Ogando, R.; Plazas, A. A.; Reil, K.; Romer, A. K.; Roodman, A.; Sanchez, E.; Sevilla-Noarbe, I.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Tarle, G.; Thaler, J.; Thomas, R. C.; Tucker, D.; Walker, A. R.

    2015-11-06

    We describe the operation and performance of the difference imaging pipeline (DiffImg) used to detect transients in deep images from the Dark Energy Survey Supernova program (DES-SN) in its first observing season from 2013 August through 2014 February. DES-SN is a search for transients in which ten 3 deg(2) fields are repeatedly observed in the g, r, i, z passbands with a cadence of about 1 week. The observing strategy has been optimized to measure high-quality light curves and redshifts for thousands of Type Ia supernovae (SNe Ia) with the goal of measuring dark energy parameters. The essential DiffImg functions are to align each search image to a deep reference image, do a pixel-by-pixel subtraction, and then examine the subtracted image for significant positive detections of point-source objects. The vast majority of detections are subtraction artifacts, but after selection requirements and image filtering with an automated scanning program, there are similar to 130 detections per deg(2) per observation in each band, of which only similar to 25% are artifacts. Of the similar to 7500 transients discovered by DES-SN in its first observing season, each requiring a detection on at least two separate nights, Monte Carlo (MC) simulations predict that 27% are expected to be SNe Ia or core-collapse SNe. Another similar to 30% of the transients are artifacts in which a small number of observations satisfy the selection criteria for a single-epoch detection. Spectroscopic analysis shows that most of the remaining transients are AGNs and variable stars. Fake SNe Ia are overlaid onto the images to rigorously evaluate detection efficiencies and to understand the DiffImg performance. The DiffImg efficiency measured with fake SNe agrees well with expectations from a MC simulation that uses analytical calculations of the fluxes and their uncertainties. In our 8 "shallow" fields with single-epoch 50% completeness depth similar to 23.5, the SN Ia efficiency falls to 1/2 at

  10. Understanding Supermassive Black Holes Using the Dark Energy Survey and OzDES

    Science.gov (United States)

    Mudd, Dale Montaine

    I present the initial results of characterizing moderate redshift (z ≤ 2) quasars in the Dark Energy Survey (DES) by their variability. As the scales associated with supermassive black holes (SMBHs) are too small to be resolved directly, alternative methods are necessary to learn about their structure, how they grow, and how they impact their environments. One such method is through variability. Quasars are naturally variable objects, and by measuring the time delay to different emitting regions as they respond to changes in the extreme ionizing UV photons produced at the inner edge of the disk, we can estimate normally inaccessible size scales associated with SMBHs. This technique is known as reverberation mapping. I first apply this technique to probe accretion disk sizes. Only a handful of such measurements exist in the literature, sampled through reverberation mapping or gravitational microlensing. I measure time delays between the DES photometric bands to place constraints on accretion disk sizes, and then present a software extension to the JAVELIN code that provides a Bayesian framework for fitting a thin accretion disk model directly to the data rather than the individual lags themselves. This is tested on fake data as well as the highest quality dataset available for a local active galaxy, NGC 5548, before being applied to a sample of DES quasars. This new framework, under our thin disk assumption, gives competitive accretion disk sizes for quasars with our survey quality data alone, and adds over a dozen objects to the relatively small number of quasars with measured disk properties. Next, I present the serendipitous discovery of a z=0.65 low-ionization broad absorption line (LoBAL) quasar in a post-starburst galaxy in the DES data, spectroscopically confirmed with the Australian Dark Energy Survey (OzDES) project. LoBAL quasars are a minority of all BALs, and rarer still is that this object also exhibits broad FeII (an FeLoBAL) and Balmer absorption

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-03-31

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

  12. THE ARECIBO LEGACY FAST ALFA SURVEY: THE α.40 H I SOURCE CATALOG, ITS CHARACTERISTICS AND THEIR IMPACT ON THE DERIVATION OF THE H I MASS FUNCTION

    International Nuclear Information System (INIS)

    Haynes, Martha P.; Giovanelli, Riccardo; Martin, Ann M.; Adams, Elizabeth A. K.; Hallenbeck, Gregory; Huang Shan; Papastergis, Emmanouil

    2011-01-01

    We present a current catalog of 21 cm H I line sources extracted from the Arecibo Legacy Fast Arecibo L-band Feed Array (ALFALFA) survey over ∼2800 deg 2 of sky: the α.40 catalog. Covering 40% of the final survey area, the α.40 catalog contains 15,855 sources in the regions 07 h 30 m h 30 m , +04° h h , +14° 2 , a factor of 29 improvement over the catalog extracted from the H I Parkes All-Sky Survey. In addition to the source centroid positions, H I line flux densities, recessional velocities, and line widths, the catalog includes the coordinates of the most probable optical counterpart of each H I line detection, and a separate compilation provides a cross-match to identifications given in the photometric and spectroscopic catalogs associated with the Sloan Digital Sky Survey Data Release 7. Fewer than 2% of the extragalactic H I line sources cannot be identified with a feasible optical counterpart; some of those may be rare OH megamasers at 0.16 < z < 0.25. A detailed analysis is presented of the completeness, width-dependent sensitivity function and bias inherent of the α.40 catalog. The impact of survey selection, distance errors, current volume coverage, and local large-scale structure on the derivation of the H I mass function is assessed. While α.40 does not yet provide a completely representative sampling of cosmological volume, derivations of the H I mass function using future data releases from ALFALFA will further improve both statistical and systematic uncertainties.

  13. Wide-field infrared survey explorer observations of young stellar objects in the Lynds 1509 dark cloud in Auriga

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wilson M.; McCollum, Bruce; Fajardo-Acosta, Sergio [Infrared Processing and Analysis Center, California Institute of Technology, MC 100-22, Pasadena, CA 91125 (United States); Padgett, Deborah L. [National Aeronautics and Space Administration, Goddard Space Flight Center, Code 665, Greenbelt, MD 20771 (United States); Terebey, Susan; Angione, John [Department of Physics and Astronomy, California State University, Los Angeles, CA 90032 (United States); Rebull, Luisa M. [Spitzer Science Center, California Institute of Technology, MC 314-6, Pasadena, CA 91125 (United States); Leisawitz, David, E-mail: wliu@ipac.caltech.edu [National Aeronautics and Space Administration, Goddard Space Flight Center, Code 605, Greenbelt, MD 20771 (United States)

    2014-06-01

    The Wide-Field Infrared Survey Explorer (WISE) has uncovered a striking cluster of young stellar object (YSO) candidates associated with the L1509 dark cloud in Auriga. The WISE observations, at 3.4 μm, 4.6 μm, 12 μm, and 22 μm, show a number of objects with colors consistent with YSOs, and their spectral energy distributions suggest the presence of circumstellar dust emission, including numerous Class I, flat spectrum, and Class II objects. In general, the YSOs in L1509 are much more tightly clustered than YSOs in other dark clouds in the Taurus-Auriga star forming region, with Class I and flat spectrum objects confined to the densest aggregates, and Class II objects more sparsely distributed. We estimate a most probable distance of 485-700 pc, and possibly as far as the previously estimated distance of 2 kpc.

  14. Preliminary Results of Detailed Chemical Abundance Analysis of Milky Way Satellite Galaxy Reticulum II Discovered in the Dark Energy Survey

    Science.gov (United States)

    Nagasawa, Daniel; Marshall, Jennifer L.; Li, Ting; Dark Energy Survey Milky Way Science Group

    2016-01-01

    We present preliminary results from abundance analysis of stars in Milky Way satellite galaxies found in the Dark Energy Survey (DES). DES has discovered 16 candidate satellite galaxies of the Milky Way in its first two years of operation. Since January 2015, three candidates have subsequently been revealed to be dark matter-dominated by spectroscopic follow-up studies of their kinematics, confirming their status as satellite galaxies. Spectroscopic follow-up of the remaining 13 candidates is underway. We have analyzed high resolution VLT/GIRAFFE spectra of member stars in one of these satellite galaxies, Reticulum II. Using equivalent width measurement and spectral synthesis methods, we measure the abundances of Iron and other species in order to begin to understand the chemical content of these Milky Way satellites.

  15. The Java Legacy Interface

    DEFF Research Database (Denmark)

    Korsholm, Stephan

    2007-01-01

    The Java Legacy Interface is designed to use Java for encapsulating native legacy code on small embedded platforms. We discuss why existing technologies for encapsulating legacy code (JNI) is not sufficient for an important range of small embedded platforms, and we show how the Java Legacy...... Interface offers this previously missing functionality. We describe an implementation of the Java Legacy Interface for a particular virtual machine, and how we have used this virtual machine to integrate Java with an existing, commercial, soft real-time, C/C++ legacy platform....

  16. Dark Energy Survey Year 1 Results: Redshift distributions of the weak lensing source galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Hoyle, B.; et al.

    2017-08-04

    We describe the derivation and validation of redshift distribution estimates and their uncertainties for the galaxies used as weak lensing sources in the Dark Energy Survey (DES) Year 1 cosmological analyses. The Bayesian Photometric Redshift (BPZ) code is used to assign galaxies to four redshift bins between z=0.2 and 1.3, and to produce initial estimates of the lensing-weighted redshift distributions $n^i_{PZ}(z)$ for bin i. Accurate determination of cosmological parameters depends critically on knowledge of $n^i$ but is insensitive to bin assignments or redshift errors for individual galaxies. The cosmological analyses allow for shifts $n^i(z)=n^i_{PZ}(z-\\Delta z^i)$ to correct the mean redshift of $n^i(z)$ for biases in $n^i_{\\rm PZ}$. The $\\Delta z^i$ are constrained by comparison of independently estimated 30-band photometric redshifts of galaxies in the COSMOS field to BPZ estimates made from the DES griz fluxes, for a sample matched in fluxes, pre-seeing size, and lensing weight to the DES weak-lensing sources. In companion papers, the $\\Delta z^i$ are further constrained by the angular clustering of the source galaxies around red galaxies with secure photometric redshifts at 0.15

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-08-04

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

  18. Holistic information evaluation of divergence of soil's properties by using of legacy data of large scale monitoring surveys

    Science.gov (United States)

    Mikheeva, Irina

    2017-04-01

    Identification of tendencies of soil's transformations is very important for adequate ecological and economical assessment of degradation of soils. But monitoring of conditions of soils, and other natural objects, bring up a number of important methodological questions, including the probabilistic and statistical analysis of the accumulated legacy data and their use for verification of quantitative estimates of natural processes. Owing to considerable natural variability there is a problem of a reliable assessment of contemporary soil evolution under the influence of environmental management and climate changes. When studying dynamics of soil quality it is necessary to consider soil as open complex system with parameters which significantly vary in space. The analysis of probabilistic distributions of attributes of studied system is informative for the characteristic of holistic state and behavior of the system. Therefore earlier we had offered the method of evaluation of alterations of soils by analysis of changes of pdf of their properties and their statistical entropy. The executed analysis of dynamics of pdf showed that often opposite tendencies to decrease and to increase of property can be shown at the same time. However to give an adequate quantitative evaluation of changes of soil properties it is necessary to characterize them in general. We proposed that it is reasonable to name processes of modern changes in soil properties concerning their start meaning by the term "divergence" and investigate it quantitatively. For this purpose we suggested to use value of information divergence which is defined as a measure of distinctions of pdf in compared objects or in various time. As the measure of dissimilarity, divergence should satisfy come conditions, the most important is scale-invariance property. Information divergence was used by us for evaluation of distinctions of soils according heterogeneity of factors of soil formation and with course of natural and

  19. The DiskMass Survey : IV. The Dark-matter-dominated Galaxy UGC 463

    NARCIS (Netherlands)

    Westfall, Kyle B.; Bershady, Matthew A.; Verheijen, Marc A. W.; Andersen, David R.; Martinsson, Thomas P. K.; Swaters, Robert A.; Schechtman-Rook, Andrew

    2011-01-01

    We present a detailed and unique mass budget for the high surface brightness galaxy UGC 463, showing it is dominated by dark matter (DM) at radii beyond one scale length (h(R)) and has a baryonic-to-DM mass ratio of approximately 1:3 within 4.2h(R). Assuming a constant scale height (h(z); calculated

  20. The DiskMass Survey. IV. The Dark-matter-dominated Galaxy UGC 463

    NARCIS (Netherlands)

    Westfall, Kyle B.; Bershady, Matthew A.; Verheijen, Marc A. W.; Andersen, David R.; Martinsson, Thomas P. K.; Swaters, Robert A.; Schechtman-Rook, Andrew

    2011-01-01

    We present a detailed and unique mass budget for the high surface brightness galaxy UGC 463, showing it is dominated by dark matter (DM) at radii beyond one scale length (hR ) and has a baryonic-to-DM mass ratio of approximately 1:3 within 4.2hR . Assuming a constant scale height (hz ; calculated

  1. The DiskMass Survey. VII. The distribution of luminous and dark matter in spiral galaxies

    NARCIS (Netherlands)

    Martinsson, Thomas P. K.; Verheijen, Marc A. W.; Westfall, Kyle B.; Bershady, Matthew A.; Andersen, David R.; Swaters, Rob A.

    We present dynamically-determined rotation-curve mass decompositions of 30 spiral galaxies, which were carried out to test the maximum-disk hypothesis and to quantify properties of their dark-matter halos. We used measured vertical velocity dispersions of the disk stars to calculate dynamical mass

  2. The DiskMass Survey : VII. The distribution of luminous and dark matter in spiral galaxies

    NARCIS (Netherlands)

    Martinsson, Thomas P. K.; Verheijen, Marc A. W.; Westfall, Kyle B.; Bershady, Matthew A.; Andersen, David R.; Swaters, Rob A.

    We present dynamically- determined rotation- curve mass decompositions of 30 spiral galaxies, which were carried out to test the maximum- disk hypothesis and to quantify properties of their dark- matter halos. We used measured vertical velocity dispersions of the disk stars to calculate dynamical

  3. The DiskMass Survey. VII. The distribution of luminous and dark matter in spiral galaxies

    NARCIS (Netherlands)

    Martinsson, T.P.K.; Verheijen, M.; Westfall, K.; Bershady, M.; Andersen, D.; Swaters, R.

    2013-01-01

    We present dynamically-determined rotation-curve mass decompositions of 30 spiral galaxies, which were carried out to test the maximum-disk hypothesis and to quantify properties of their dark-matter halos. We used measured vertical velocity dispersions of the disk stars to calculate dynamical mass

  4. Systematic Biases in Weak Lensing Cosmology with the Dark Energy Survey

    Energy Technology Data Exchange (ETDEWEB)

    Samuroff, Simon [Manchester U.

    2017-01-01

    This thesis sets out a practical guide to applying shear measurements as a cosmological tool. We first present one of two science-ready galaxy shape catalogues from Year 1 of the Dark Energy Survey (DES Y1), which covers 1500 square degrees in four bands $griz$, with a median redshift of $0.59$. We describe the shape measurement process implemented by the DES Y1 imshape catalogue, which contains 21.9 million high-quality $r$-band bulge/disc fits. In Chapter 3 a new suite of image simulations, referred to as Hoopoe, are presented. The Hoopoe dataset is tailored to DES Y1 and includes realistic blending, spatial masks and variation in the point spread function. We derive shear corrections, which we show are robust to changes in calibration method, galaxy binning and variance within the simulated dataset. Sources of systematic uncertainty in the simulation-based shear calibration are discussed, leading to a final estimate of the $1\\sigma$ uncertainties in the residual multiplica tive bias after calibration of 0.025. Chapter 4 describes an extension of the analysis on the Hoopoe simulations into a detailed investigation of the impact of galaxy neighbours on shape measurement and shear cosmology. Four mechanisms by which neighbours can have a non-negligible influence on shear measurement are identified. These effects, if ignored, would contribute a net multiplicative bias of $m \\sim 0.03 - 0.09$ in DES Y1, though the precise impact will depend on both the measurement code and the selection cuts applied. We use the cosmological inference pipeline of DES Y1 to explore the cosmological implications of neighbour bias and show that omitting blending from the calibration simulation for DES Y1 would bias the inferred clustering amplitude $S_8 \\equiv \\sigma_8 (\\omegam /0.3)^{0.5}$ by $1.5 \\sigma$ towards low values. Finally, we use the Hoopoe simulations to test the effect of neighbour-induced spatial correlations in the multiplicative bias. We find the cosmo logical

  5. THE SWIFT GRB HOST GALAXY LEGACY SURVEY. II. REST-FRAME NEAR-IR LUMINOSITY DISTRIBUTION AND EVIDENCE FOR A NEAR-SOLAR METALLICITY THRESHOLD

    Energy Technology Data Exchange (ETDEWEB)

    Perley, D. A. [Department of Astronomy, California Institute of Technology, MC 249-17, 1200 East California Blvd., Pasadena, CA 91125 (United States); Tanvir, N. R. [Department of Physics and Astronomy, University of Leicester, University Road, Leicester, LE1 7RH (United Kingdom); Hjorth, J.; Fynbo, J. P. U.; Krühler, T. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 København Ø (Denmark); Laskar, T.; Berger, E. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Chary, R. [US Planck Data Center, MS220-6, Pasadena, CA 91125 (United States); Postigo, A. de Ugarte [Instituto de Astrofísica de Andalucía (IAA-CSIC), Glorieta de la Astronomía s/n, E-18008, Granada (Spain); Levan, A. J. [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Michałowski, M. J. [Scottish Universities Physics Alliance, Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh, EH9 3HJ (United Kingdom); Schulze, S., E-mail: dperley@dark-cosmology.dk [Instituto de Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, Vicuña Mackenna 4860, 7820436 Macul, Santiago 22 (Chile)

    2016-01-20

    We present rest-frame near-IR (NIR) luminosities and stellar masses for a large and uniformly selected population of gamma-ray burst (GRB) host galaxies using deep Spitzer Space Telescope imaging of 119 targets from the Swift GRB Host Galaxy Legacy Survey spanning 0.03 < z < 6.3, and we determine the effects of galaxy evolution and chemical enrichment on the mass distribution of the GRB host population across cosmic history. We find a rapid increase in the characteristic NIR host luminosity between z ∼ 0.5 and z ∼ 1.5, but little variation between z ∼ 1.5 and z ∼ 5. Dust-obscured GRBs dominate the massive host population but are only rarely seen associated with low-mass hosts, indicating that massive star-forming galaxies are universally and (to some extent) homogeneously dusty at high redshift while low-mass star-forming galaxies retain little dust in their interstellar medium. Comparing our luminosity distributions with field surveys and measurements of the high-z mass–metallicity relation, our results have good consistency with a model in which the GRB rate per unit star formation is constant in galaxies with gas-phase metallicity below approximately the solar value but heavily suppressed in more metal-rich environments. This model also naturally explains the previously reported “excess” in the GRB rate beyond z ≳ 2; metals stifle GRB production in most galaxies at z < 1.5 but have only minor impact at higher redshifts. The metallicity threshold we infer is much higher than predicted by single-star models and favors a binary progenitor. Our observations also constrain the fraction of cosmic star formation in low-mass galaxies undetectable to Spitzer to be small at z < 4.

  6. Euclid Mission: Mapping the Geometry of the Dark Universe. Mission and Consortium Status

    Science.gov (United States)

    Rhodes, Jason

    2011-01-01

    Euclid concept: (1) High-precision survey mission to map the geometry of the Dark Universe (2) Optimized for two complementary cosmological probes: (2a) Weak Gravitational Lensing (2b) Baryonic Acoustic Oscillations (2c) Additional probes: clusters, redshift space distortions, ISW (3) Full extragalactic sky survey with 1.2m telescope at L2: (3a) Imaging: (3a-1) High precision imaging at visible wavelengths (3a-2) Photometry/Imaging in the near-infrared (3b) Near Infrared Spectroscopy (4) Synergy with ground based surveys (5) Legacy science for a wide range of in astronomy

  7. THE MIRA–TITAN UNIVERSE: PRECISION PREDICTIONS FOR DARK ENERGY SURVEYS

    International Nuclear Information System (INIS)

    Heitmann, Katrin; Habib, Salman; Biswas, Rahul; Frontiere, Nicholas; Bhattacharya, Suman; Bingham, Derek; Bergner, Steven; Lawrence, Earl; Higdon, David; Pope, Adrian; Finkel, Hal

    2016-01-01

    Large-scale simulations of cosmic structure formation play an important role in interpreting cosmological observations at high precision. The simulations must cover a parameter range beyond the standard six cosmological parameters and need to be run at high mass and force resolution. A key simulation-based task is the generation of accurate theoretical predictions for observables using a finite number of simulation runs, via the method of emulation. Using a new sampling technique, we explore an eight-dimensional parameter space including massive neutrinos and a variable equation of state of dark energy. We construct trial emulators using two surrogate models (the linear power spectrum and an approximate halo mass function). The new sampling method allows us to build precision emulators from just 26 cosmological models and to systematically increase the emulator accuracy by adding new sets of simulations in a prescribed way. Emulator fidelity can now be continuously improved as new observational data sets become available and higher accuracy is required. Finally, using one ΛCDM cosmology as an example, we study the demands imposed on a simulation campaign to achieve the required statistics and accuracy when building emulators for investigations of dark energy

  8. THE MIRA–TITAN UNIVERSE: PRECISION PREDICTIONS FOR DARK ENERGY SURVEYS

    Energy Technology Data Exchange (ETDEWEB)

    Heitmann, Katrin; Habib, Salman; Biswas, Rahul; Frontiere, Nicholas; Bhattacharya, Suman [HEP Division, Argonne National Laboratory, Lemont, IL 60439 (United States); Bingham, Derek; Bergner, Steven [Department of Statistics and Actuarial Science, Simon Fraser University, Burnaby, BC (Canada); Lawrence, Earl [CCS-6, CCS Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Higdon, David [Social and Decision Analytics Laboratory, Virginia Bioinformatics Institute, Virginia Tech, Arlington, VA 22203 (United States); Pope, Adrian; Finkel, Hal [ALCF Division, Argonne National Laboratory, Lemont, IL 60439 (United States)

    2016-04-01

    Large-scale simulations of cosmic structure formation play an important role in interpreting cosmological observations at high precision. The simulations must cover a parameter range beyond the standard six cosmological parameters and need to be run at high mass and force resolution. A key simulation-based task is the generation of accurate theoretical predictions for observables using a finite number of simulation runs, via the method of emulation. Using a new sampling technique, we explore an eight-dimensional parameter space including massive neutrinos and a variable equation of state of dark energy. We construct trial emulators using two surrogate models (the linear power spectrum and an approximate halo mass function). The new sampling method allows us to build precision emulators from just 26 cosmological models and to systematically increase the emulator accuracy by adding new sets of simulations in a prescribed way. Emulator fidelity can now be continuously improved as new observational data sets become available and higher accuracy is required. Finally, using one ΛCDM cosmology as an example, we study the demands imposed on a simulation campaign to achieve the required statistics and accuracy when building emulators for investigations of dark energy.

  9. K2: A NEW METHOD FOR THE DETECTION OF GALAXY CLUSTERS BASED ON CANADA-FRANCE-HAWAII TELESCOPE LEGACY SURVEY MULTICOLOR IMAGES

    International Nuclear Information System (INIS)

    Thanjavur, Karun; Willis, Jon; Crampton, David

    2009-01-01

    We have developed a new method, K2, optimized for the detection of galaxy clusters in multicolor images. Based on the Red Sequence approach, K2 detects clusters using simultaneous enhancements in both colors and position. The detection significance is robustly determined through extensive Monte Carlo simulations and through comparison with available cluster catalogs based on two different optical methods, and also on X-ray data. K2 also provides quantitative estimates of the candidate clusters' richness and photometric redshifts. Initially, K2 was applied to the two color (gri) 161 deg 2 images of the Canada-France-Hawaii Telescope Legacy Survey Wide (CFHTLS-W) data. Our simulations show that the false detection rate for these data, at our selected threshold, is only ∼1%, and that the cluster catalogs are ∼80% complete up to a redshift of z = 0.6 for Fornax-like and richer clusters and to z ∼ 0.3 for poorer clusters. Based on the g-, r-, and i-band photometric catalogs of the Terapix T05 release, 35 clusters/deg 2 are detected, with 1-2 Fornax-like or richer clusters every 2 deg 2 . Catalogs containing data for 6144 galaxy clusters have been prepared, of which 239 are rich clusters. These clusters, especially the latter, are being searched for gravitational lenses-one of our chief motivations for cluster detection in CFHTLS. The K2 method can be easily extended to use additional color information and thus improve overall cluster detection to higher redshifts. The complete set of K2 cluster catalogs, along with the supplementary catalogs for the member galaxies, are available on request from the authors.

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

    Science.gov (United States)

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

    2017-06-01

    We report the large effort that is producing comprehensive high-level young star cluster (YSC) catalogs for a significant fraction of galaxies observed with the Legacy ExtraGalactic UV Survey (LEGUS) Hubble treasury program. We present the methodology developed to extract cluster positions, verify their genuine nature, produce multiband photometry (from NUV to NIR), and derive their physical properties via spectral energy distribution fitting analyses. We use the nearby spiral galaxy NGC 628 as a test case for demonstrating the impact that LEGUS will have on our understanding of the formation and evolution of YSCs and compact stellar associations within their host galaxy. Our analysis of the cluster luminosity function from the UV to the NIR finds a steepening at the bright end and at all wavelengths suggesting a dearth of luminous clusters. The cluster mass function of NGC 628 is consistent with a power-law distribution of slopes ˜ -2 and a truncation of a few times 105 {M}⊙ . After their formation, YSCs and compact associations follow different evolutionary paths. YSCs survive for a longer time frame, confirming their being potentially bound systems. Associations disappear on timescales comparable to hierarchically organized star-forming regions, suggesting that they are expanding systems. We find mass-independent cluster disruption in the inner region of NGC 628, while in the outer part of the galaxy there is little or no disruption. We observe faster disruption rates for low mass (≤104 {M}⊙ ) clusters, suggesting that a mass-dependent component is necessary to fully describe the YSC disruption process in NGC 628. Based on observations obtained with the NASA/ESA Hubble Space Telescope, at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

  11. OzDES multifibre spectroscopy for the Dark Energy Survey: 3-yr results and first data release

    Science.gov (United States)

    Childress, M. J.; Lidman, C.; Davis, T. M.; Tucker, B. E.; Asorey, J.; Yuan, F.; Abbott, T. M. C.; Abdalla, F. B.; Allam, S.; Annis, J.; Banerji, M.; Benoit-Lévy, A.; Bernard, S. R.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Burke, D. L.; Carnero Rosell, A.; Carollo, D.; Carrasco Kind, M.; Carretero, J.; Castander, F. J.; Cunha, C. E.; da Costa, L. N.; D'Andrea, C. B.; Doel, P.; Eifler, T. F.; Evrard, A. E.; Flaugher, B.; Foley, R. J.; Fosalba, P.; Frieman, J.; García-Bellido, J.; Glazebrook, K.; Goldstein, D. A.; Gruen, D.; Gruendl, R. A.; Gschwend, J.; Gupta, R. R.; Gutierrez, G.; Hinton, S. R.; Hoormann, J. K.; James, D. J.; Kessler, R.; Kim, A. G.; King, A. L.; Kovacs, E.; Kuehn, K.; Kuhlmann, S.; Kuropatkin, N.; Lagattuta, D. J.; Lewis, G. F.; Li, T. S.; Lima, M.; Lin, H.; Macaulay, E.; Maia, M. A. G.; Marriner, J.; March, M.; Marshall, J. L.; Martini, P.; McMahon, R. G.; Menanteau, F.; Miquel, R.; Moller, A.; Morganson, E.; Mould, J.; Mudd, D.; Muthukrishna, D.; Nichol, R. C.; Nord, B.; Ogando, R. L. C.; Ostrovski, F.; Parkinson, D.; Plazas, A. A.; Reed, S. L.; Reil, K.; Romer, A. K.; Rykoff, E. S.; Sako, M.; Sanchez, E.; Scarpine, V.; Schindler, R.; Schubnell, M.; Scolnic, D.; Sevilla-Noarbe, I.; Seymour, N.; Sharp, R.; Smith, M.; Soares-Santos, M.; Sobreira, F.; Sommer, N. E.; Spinka, H.; Suchyta, E.; Sullivan, M.; Swanson, M. E. C.; Tarle, G.; Uddin, S. A.; Walker, A. R.; Wester, W.; Zhang, B. R.

    2017-11-01

    We present results for the first three years of OzDES, a six year programme to obtain redshifts for objects in the Dark Energy Survey (DES) supernova fields using the 2dF fibre positioner and AAOmega spectrograph on the Anglo-Australian Telescope. OzDES is a multi-object spectroscopic survey targeting multiple types of targets at multiple epochs over a multiyear baseline and is one of the first multi-object spectroscopic surveys to dynamically include transients into the target list soon after their discovery. At the end of three years, OzDES has spectroscopically confirmed almost 100 supernovae, and has measured redshifts for 17 000 objects, including the redshifts of 2566 supernova hosts. We examine how our ability to measure redshifts for targets of various types depends on signal-to-noise ratio (S/N), magnitude and exposure time, finding that our redshift success rate increases significantly at a S/N of 2-3 per 1-Å bin. We also find that the change in S/N with exposure time closely matches the Poisson limit for stacked exposures as long as 10 h. We use these results to predict the redshift yield of the full OzDES survey, as well as the potential yields of future surveys on other facilities such as (i.e. the 4-m Multi-Object Spectroscopic Telescope, the Subaru Prime Focus Spectrograph and the Maunakea Spectroscopic Explorer). This work marks the first OzDES data release, comprising 14 693 redshifts. OzDES is on target to obtain over 30 000 redshifts over the 6-yr duration of the survey, including a yield of approximately 5700 supernova host-galaxy redshifts.

  12. Outflows, infall and evolution of a sample of embedded low-mass protostars. The William Herschel Line Legacy (WILL) survey

    Science.gov (United States)

    Mottram, J. C.; van Dishoeck, E. F.; Kristensen, L. E.; Karska, A.; San José-García, I.; Khanna, S.; Herczeg, G. J.; André, Ph.; Bontemps, S.; Cabrit, S.; Carney, M. T.; Drozdovskaya, M. N.; Dunham, M. M.; Evans, N. J.; Fedele, D.; Green, J. D.; Harsono, D.; Johnstone, D.; Jørgensen, J. K.; Könyves, V.; Nisini, B.; Persson, M. V.; Tafalla, M.; Visser, R.; Yıldız, U. A.

    2017-04-01

    Context. Herschel observations of water and highly excited CO (J > 9) have allowed the physical and chemical conditions in the more active parts of protostellar outflows to be quantified in detail for the first time. However, to date, the studied samples of Class 0/I protostars in nearby star-forming regions have been selected from bright, well-known sources and have not been large enough for statistically significant trends to be firmly established. Aims: We aim to explore the relationships between the outflow, envelope and physical properties of a flux-limited sample of embedded low-mass Class 0/I protostars. Methods: We present spectroscopic observations in H2O, CO and related species with Herschel HIFI and PACS, as well as ground-based follow-up with the JCMT and APEX in CO, HCO+ and isotopologues, of a sample of 49 nearby (d Gould Belt. This more than doubles the sample of sources observed by the WISH and DIGIT surveys. These data are used to study the outflow and envelope properties of these sources. We also compile their continuum spectral energy distributions (SEDs) from the near-IR to mm wavelengths in order to constrain their physical properties (e.g. Lbol, Tbol and Menv). Results: Water emission is dominated by shocks associated with the outflow, rather than the cooler, slower entrained outflowing gas probed by ground-based CO observations. These shocks become less energetic as sources evolve from Class 0 to Class I. Outflow force, measured from low-J CO, also decreases with source evolutionary stage, while the fraction of mass in the outflow relative to the total envelope (I.e. Mout/Menv) remains broadly constant between Class 0 and I. The median value of 1% is consistent with a core to star formation efficiency on the order of 50% and an outflow duty cycle on the order of 5%. Entrainment efficiency, as probed by FCO/Ṁacc, is also invariant with source properties and evolutionary stage. The median value implies a velocity at the wind launching radius

  13. Dark Energy Survey Year 1 results: the impact of galaxy neighbours on weak lensing cosmology with IM3SHAPE

    Science.gov (United States)

    Samuroff, S.; Bridle, S. L.; Zuntz, J.; Troxel, M. A.; Gruen, D.; Rollins, R. P.; Bernstein, G. M.; Eifler, T. F.; Huff, E. M.; Kacprzak, T.; Krause, E.; MacCrann, N.; Abdalla, F. B.; Allam, S.; Annis, J.; Bechtol, K.; Benoit-Lévy, A.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Carnero Rosell, A.; Carrasco Kind, M.; Carretero, J.; Crocce, M.; D'Andrea, C. B.; da Costa, L. N.; Davis, C.; Desai, S.; Doel, P.; Fausti Neto, A.; Flaugher, B.; Fosalba, P.; Frieman, J.; García-Bellido, J.; Gerdes, D. W.; Gruendl, R. A.; Gschwend, J.; Gutierrez, G.; Honscheid, K.; James, D. J.; Jarvis, M.; Jeltema, T.; Kirk, D.; Kuehn, K.; Kuhlmann, S.; Li, T. S.; Lima, M.; Maia, M. A. G.; March, M.; Marshall, J. L.; Martini, P.; Melchior, P.; Menanteau, F.; Miquel, R.; Nord, B.; Ogando, R. L. C.; Plazas, A. A.; Roodman, A.; Sanchez, E.; Scarpine, V.; Schindler, R.; Schubnell, M.; Sevilla-Noarbe, I.; Sheldon, E.; Smith, M.; Soares-Santos, M.; Sobreira, F.; Suchyta, E.; Tarle, G.; Thomas, D.; Tucker, D. L.; DES Collaboration

    2018-04-01

    We use a suite of simulated images based on Year 1 of the Dark Energy Survey to explore the impact of galaxy neighbours on shape measurement and shear cosmology. The HOOPOE image simulations include realistic blending, galaxy positions, and spatial variations in depth and point spread function properties. Using the IM3SHAPE maximum-likelihood shape measurement code, we identify four mechanisms by which neighbours can have a non-negligible influence on shear estimation. These effects, if ignored, would contribute a net multiplicative bias of m ˜ 0.03-0.09 in the Year One of the Dark Energy Survey (DES Y1) IM3SHAPE catalogue, though the precise impact will be dependent on both the measurement code and the selection cuts applied. This can be reduced to percentage level or less by removing objects with close neighbours, at a cost to the effective number density of galaxies neff of 30 per cent. We use the cosmological inference pipeline of DES Y1 to explore the cosmological implications of neighbour bias and show that omitting blending from the calibration simulation for DES Y1 would bias the inferred clustering amplitude S8 ≡ σ8(Ωm/0.3)0.5 by 2σ towards low values. Finally, we use the HOOPOE simulations to test the effect of neighbour-induced spatial correlations in the multiplicative bias. We find the impact on the recovered S8 of ignoring such correlations to be subdominant to statistical error at the current level of precision.

  14. A Limited Survey of Dark Chocolate Bars Obtained in the United States for Undeclared Milk and Peanut Allergens.

    Science.gov (United States)

    Bedford, Binaifer; Yu, Ye; Wang, Xue; Garber, Eric A E; Jackson, Lauren S

    2017-04-01

    Undeclared allergens in chocolate products have been responsible for numerous allergen-related recalls in the United States. A survey was conducted to determine the prevalence of undeclared milk and peanut in 88 and 78 dark chocolate bars, respectively. Concentrations of milk (as nonfat dry milk) or peanut in three samples of each chocolate product were determined with two milk- or peanut-specific enzyme-linked immunosorbent assay kits. In 75% of the chocolate bar products with a milk advisory statement, milk concentrations were above the limit of quantitation (2.5 μg/g [ppm]), with the majority having concentrations >1,000 ppm. An additional 67% of chocolate bars with a "traces of milk" statement contained 3 to 6,700 ppm of milk. Fifteen percent of chocolates labeled dairy free or lactose free and 25% labeled vegan were positive for milk, all with concentrations >1,000 ppm. Even for chocolates with no reference to milk on the label, 33% of these products contained 60 to 3,400 ppm of milk. The survey of chocolate products for peanuts revealed that 8% of products with an advisory statement contained peanut, with the highest concentration of 550 ppm. All nine chocolates bearing the peanut-free or allergen-free statement were negative for peanut, but 17% of chocolates with no label statement for peanut were positive for peanut at concentrations of 9 to 170 ppm. Evaluation of multiple lots of four chocolate products revealed that milk was consistently present or absent for the products investigated, but mixed results were obtained when multiple lots were tested for peanut. This study indicates that a large proportion of dark chocolate bars contain undeclared milk. The type of advisory statement or the absence of a milk advisory statement on products did not predict the amount or absence of milk protein. In contrast, a lower proportion of chocolates containing undeclared peanut was found. Consumers with food allergies should be cautious when purchasing dark chocolate

  15. Dark Energy Survey Year 1 Results: A Precise H0 Measurement from DES Y1, BAO, and D/H Data

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-11-01

    We combine Dark Energy Survey Year 1 clustering and weak lensing data with Baryon Acoustic Oscillations (BAO) and Big Bang Nucleosynthesis (BBN) experiments to constrain the Hubble constant. Assuming a flat $\\Lambda$CDM model with minimal neutrino mass ($\\sum m_\

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

    International Nuclear Information System (INIS)

    Park, Y.; Krause, E.; Dodelson, S.; Jain, B.; Amara, A.

    2016-01-01

    Here, the joint analysis of galaxy-galaxy lensing and galaxy clustering is a promising method for inferring the growth function of large-scale structure. Anticipating a near future application of this analysis to Dark Energy Survey (DES) measurements of galaxy positions and shapes, we develop a practical approach to modeling the assumptions and systematic effects affecting the joint analysis of small-scale galaxy-galaxy lensing and large-scale galaxy clustering. Introducing parameters that characterize the halo occupation distribution (HOD), photometric redshift uncertainties, and shear measurement errors, we study how external priors on different subsets of these parameters affect our growth constraints. Degeneracies within the HOD model, as well as between the HOD and the growth function, are identified as the dominant source of complication, with other systematic effects being subdominant. The impact of HOD parameters and their degeneracies necessitate the detailed joint modeling of the galaxy sample that we employ. We conclude that DES data will provide powerful constraints on the evolution of structure growth in the Universe, conservatively/optimistically constraining the growth function to 7.9%/4.8% with its first-year data that cover over 1000 square degrees, and to 3.9%/2.3% with its full five-year data that will survey 5000 square degrees, including both statistical and systematic uncertainties.

  17. Galaxy bias from the Dark Energy Survey Science Verification data: combining galaxy density maps and weak lensing maps

    Energy Technology Data Exchange (ETDEWEB)

    Chang, C.; Pujol, A.; Gaztañaga, E.; Amara, A.; Réfrégier, A.; Bacon, D.; Becker, M. R.; Bonnett, C.; Carretero, J.; Castander, F. J.; Crocce, M.; Fosalba, P.; Giannantonio, T.; Hartley, W.; Jarvis, M.; Kacprzak, T.; Ross, A. J.; Sheldon, E.; Troxel, M. A.; Vikram, V.; Zuntz, J.; Abbott, T. M. C.; Abdalla, F. B.; Allam, S.; Annis, J.; Benoit-Lévy, A.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Burke, D. L.; Capozzi, D.; Rosell, A. Carnero; Kind, M. Carrasco; Cunha, C. E.; D' Andrea, C. B.; da Costa, L. N.; Desai, S.; Diehl, H. T.; Dietrich, J. P.; Doel, P.; Eifler, T. F.; Estrada, J.; Evrard, A. E.; Flaugher, B.; Frieman, J.; Goldstein, D. A.; Gruen, D.; Gruendl, R. A.; Gutierrez, G.; Honscheid, K.; Jain, B.; James, D. J.; Kuehn, K.; Kuropatkin, N.; Lahav, O.; Li, T. S.; Lima, M.; Marshall, J. L.; Martini, P.; Melchior, P.; Miller, C. J.; Miquel, R.; Mohr, J. J.; Nichol, R. C.; Nord, B.; Ogando, R.; Plazas, A. A.; Reil, K.; Romer, A. K.; Roodman, A.; Rykoff, E. S.; Sanchez, E.; Scarpine, V.; Schubnell, M.; Sevilla-Noarbe, I.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; Walker, A. R.

    2016-04-15

    We measure the redshift evolution of galaxy bias from a magnitude-limited galaxy sample by combining the galaxy density maps and weak lensing shear maps for a $\\sim$116 deg$^{2}$ area of the Dark Energy Survey (DES) Science Verification data. This method was first developed in Amara et al. (2012) and later re-examined in a companion paper (Pujol et al., in prep) with rigorous simulation tests and analytical treatment of tomographic measurements. In this work we apply this method to the DES SV data and measure the galaxy bias for a magnitude-limited galaxy sample. We find the galaxy bias and 1$\\sigma$ error bars in 4 photometric redshift bins to be 1.33$\\pm$0.18 (z=0.2-0.4), 1.19$\\pm$0.23 (z=0.4-0.6), 0.99$\\pm$0.36 ( z=0.6-0.8), and 1.66$\\pm$0.56 (z=0.8-1.0). These measurements are consistent at the 1-2$\\sigma$ level with mea- surements on the same dataset using galaxy clustering and cross-correlation of galaxies with CMB lensing. In addition, our method provides the only $\\sigma_8$-independent constraint among the three. We forward-model the main observational effects using mock galaxy catalogs by including shape noise, photo-z errors and masking effects. We show that our bias measurement from the data is consistent with that expected from simulations. With the forthcoming full DES data set, we expect this method to provide additional constraints on the galaxy bias measurement from more traditional methods. Furthermore, in the process of our measurement, we build up a 3D mass map that allows further exploration of the dark matter distribution and its relation to galaxy evolution.

  18. (Almost) Dark Galaxies in the ALFALFA Survey: Isolated H i-bearing Ultra-diffuse Galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Leisman, Lukas; Haynes, Martha P.; Giovanelli, Riccardo [Cornell Center for Astrophysics and Planetary Science, Space Sciences Building, Cornell University, Ithaca, NY 14853 (United States); Janowiecki, Steven [International Centre for Radio Astronomy Research (ICRAR), University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 (Australia); Hallenbeck, Gregory [Department of Physics and Astronomy, Union College, Schenectady, NY 12308 (United States); Józsa, Gyula [SKA South Africa Radio Astronomy Research Group, 3rd Floor, The Park, Park Road, Pinelands 7405 (South Africa); Adams, Elizabeth A. K. [ASTRON, the Netherlands Institute for Radio Astronomy, Postbus 2, 7990 AA, Dwingeloo (Netherlands); Neira, David Bernal [Departamento de Física, Universidad de los Andes, Cra. 1 No. 18A-10, Edificio Ip, Bogotá (Colombia); Cannon, John M. [Department of Physics and Astronomy, Macalester College, 1600 Grand Avenue, Saint Paul, MN 55105 (United States); Janesh, William F.; Rhode, Katherine L.; Salzer, John J. [Department of Astronomy, Indiana University, 727 East Third Street, Bloomington, IN 47405 (United States)

    2017-06-20

    We present a sample of 115 very low optical surface brightness, highly extended, H i-rich galaxies carefully selected from the ALFALFA survey that have similar optical absolute magnitudes, surface brightnesses, and radii to recently discovered “ultra-diffuse” galaxies (UDGs). However, these systems are bluer and have more irregular morphologies than other UDGs, are isolated, and contain significant reservoirs of H i. We find that while these sources have normal star formation rates for H i-selected galaxies of similar stellar mass, they have very low star formation efficiencies. We further present deep optical and H i-synthesis follow-up imaging of three of these H i-bearing ultra-diffuse sources. We measure H i diameters extending to ∼40 kpc, but note that while all three sources have large H i diameters for their stellar mass, they are consistent with the H i mass–H i radius relation. We further analyze the H i velocity widths and rotation velocities for the unresolved and resolved sources, respectively, and find that the sources appear to inhabit halos of dwarf galaxies. We estimate spin parameters, and suggest that these sources may exist in high spin parameter halos, and as such may be potential H i-rich progenitors to the ultra-diffuse galaxies observed in cluster environments.

  19. (Almost) Dark Galaxies in the ALFALFA Survey: Isolated H I-bearing Ultra-diffuse Galaxies

    Science.gov (United States)

    Leisman, Lukas; Haynes, Martha P.; Janowiecki, Steven; Hallenbeck, Gregory; Józsa, Gyula; Giovanelli, Riccardo; Adams, Elizabeth A. K.; Bernal Neira, David; Cannon, John M.; Janesh, William F.; Rhode, Katherine L.; Salzer, John J.

    2017-06-01

    We present a sample of 115 very low optical surface brightness, highly extended, H I-rich galaxies carefully selected from the ALFALFA survey that have similar optical absolute magnitudes, surface brightnesses, and radii to recently discovered “ultra-diffuse” galaxies (UDGs). However, these systems are bluer and have more irregular morphologies than other UDGs, are isolated, and contain significant reservoirs of H I. We find that while these sources have normal star formation rates for H I-selected galaxies of similar stellar mass, they have very low star formation efficiencies. We further present deep optical and H I-synthesis follow-up imaging of three of these H I-bearing ultra-diffuse sources. We measure H I diameters extending to ˜40 kpc, but note that while all three sources have large H I diameters for their stellar mass, they are consistent with the H I mass-H I radius relation. We further analyze the H I velocity widths and rotation velocities for the unresolved and resolved sources, respectively, and find that the sources appear to inhabit halos of dwarf galaxies. We estimate spin parameters, and suggest that these sources may exist in high spin parameter halos, and as such may be potential H I-rich progenitors to the ultra-diffuse galaxies observed in cluster environments.

  20. Dark group: dark energy and dark matter

    International Nuclear Information System (INIS)

    Macorra, A. de la

    2004-01-01

    We study the possibility that a dark group, a gauge group with particles interacting with the standard model particles only via gravity, is responsible for containing the dark energy and dark matter required by present day observations. We show that it is indeed possible and we determine the constrains for the dark group. The non-perturbative effects generated by a strong gauge coupling constant can de determined and a inverse power law scalar potential IPL for the dark meson fields is generated parameterizing the dark energy. On the other hand it is the massive particles, e.g., dark baryons, of the dark gauge group that give the corresponding dark matter. The mass of the dark particles is of the order of the condensation scale Λ c and the temperature is smaller then the photon's temperature. The dark matter is of the warm matter type. The only parameters of the model are the number of particles of the dark group. The allowed values of the different parameters are severely restricted. The dark group energy density at Λ c must be Ω DGc ≤0.17 and the evolution and acceptable values of dark matter and dark energy leads to a constrain of Λ c and the IPL parameter n giving Λ c =O(1-10 3 ) eV and 0.28≤n≤1.04

  1. The Sloan Digital Sky Survey Quasar Lens Search. VI. Constraints on Dark Energy and the Evolution of Massive Galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Oguri, Masamune [Univ. of Tokyo (Japan); et al.

    2012-05-01

    We present a statistical analysis of the final lens sample from the Sloan Digital Sky Survey Quasar Lens Search (SQLS). The number distribution of a complete subsample of 19 lensed quasars selected from 50,836 source quasars is compared with theoretical expectations, with particular attention to the selection function. Assuming that the velocity function of galaxies does not evolve with redshift, the SQLS sample constrains the cosmological constant to \\Omega_\\Lambda=0.79^{+0.06}_{-0.07}(stat.)^{+0.06}_{-0.06}(syst.) for a flat universe. The dark energy equation of state is found to be consistent with w=-1 when the SQLS is combined with constraints from baryon acoustic oscillation (BAO) measurements or results from the Wilkinson Microwave Anisotropy Probe (WMAP). We also obtain simultaneous constraints on cosmological parameters and redshift evolution of the galaxy velocity function, finding no evidence for redshift evolution at z<1 in any combinations of constraints. For instance, number density evolution quantified as \

  2. Dark Energy Survey Year 1 Results: The Impact of Galaxy Neighbours on Weak Lensing Cosmology with im3shape

    Energy Technology Data Exchange (ETDEWEB)

    Samuroff, S.; et al.

    2017-08-04

    We use a suite of simulated images based on Year 1 of the Dark Energy Survey to explore the impact of galaxy neighbours on shape measurement and shear cosmology. The hoopoe image simulations include realistic blending, galaxy positions, and spatial variations in depth and PSF properties. Using the im3shape maximum-likelihood shape measurement code, we identify four mechanisms by which neighbours can have a non-negligible influence on shear estimation. These effects, if ignored, would contribute a net multiplicative bias of $m \\sim 0.03 - 0.09$ in the DES Y1 im3shape catalogue, though the precise impact will be dependent on both the measurement code and the selection cuts applied. This can be reduced to percentage level or less by removing objects with close neighbours, at a cost to the effective number density of galaxies $n_\\mathrm{eff}$ of 30%. We use the cosmological inference pipeline of DES Y1 to explore the cosmological implications of neighbour bias and show that omitting blending from the calibration simulation for DES Y1 would bias the inferred clustering amplitude $S_8\\equiv \\sigma_8 (\\Omega _\\mathrm{m} /0.3)^{0.5}$ by $2 \\sigma$ towards low values. Finally, we use the hoopoe simulations to test the effect of neighbour-induced spatial correlations in the multiplicative bias. We find the impact on the recovered $S_8$ of ignoring such correlations to be subdominant to statistical error at the current level of precision.

  3. The WiggleZ Dark Energy Survey: constraining the evolution of Newton's constant using the growth rate of structure

    International Nuclear Information System (INIS)

    Nesseris, Savvas; Blake, Chris; Davis, Tamara; Parkinson, David

    2011-01-01

    We constrain the evolution of Newton's constant using the growth rate of large-scale structure measured by the WiggleZ Dark Energy Survey in the redshift range 0.1 m (assuming General Relativity), and use this to construct a diagnostic to detect the presence of an evolving Newton's constant. Secondly we directly measure the evolution of Newton's constant, G eff , that appears in Modified Gravity theories, without assuming General Relativity to be true. The novelty of these approaches are that, contrary to other methods, they do not require knowledge of the expansion history of the Universe, H(z), making them model independent tests. Our constraints for the second derivative of Newton's constant at the present day, assuming it is slowly evolving as suggested by Big Bang Nucleosynthesis constraints, using the WiggleZ data is G double-dot eff (t 0 ) = −1.19 ± 0.95·10 −20 h 2 yr −2 , where h is defined via H 0 = 100 h km s −1 Mpc −1 , while using both the WiggleZ and the Sloan Digital Sky Survey Luminous Red Galaxy (SDSS LRG) data is G double-dot eff (t 0 ) = −3.6 ± 6.8·10 −21 h 2 yr −2 , both being consistent with General Relativity. Finally, our constraint for the rms mass fluctuation σ 8 using the WiggleZ data is σ 8 = 0.75 ± 0.08, while using both the WiggleZ and the SDSS LRG data σ 8 = 0.77 ± 0.07, both in good agreement with the latest measurements from the Cosmic Microwave Background radiation

  4. Evolution of Galaxy Luminosity and Stellar-Mass Functions since $z=1$ with the Dark Energy Survey Science Verification Data

    Energy Technology Data Exchange (ETDEWEB)

    Capozzi, D.; et al.

    2017-07-27

    We present the first study of the evolution of the galaxy luminosity and stellar-mass functions (GLF and GSMF) carried out by the Dark Energy Survey (DES). We describe the COMMODORE galaxy catalogue selected from Science Verification images. This catalogue is made of $\\sim 4\\times 10^{6}$ galaxies at $0Survey out to $z\\sim1$. At $0.2

  5. Comparing Dark Energy Survey and HST –CLASH observations of the galaxy cluster RXC J2248.7-4431: implications for stellar mass versus dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Palmese, A.; Lahav, O.; Banerji, M.; Gruen, D.; Jouvel, S.; Melchior, P.; Aleksić, J.; Annis, J.; Diehl, H. T.; Hartley, W. G.; Jeltema, T.; Romer, A. K.; Rozo, E.; Rykoff, E. S.; Seitz, S.; Suchyta, E.; Zhang, Y.; Abbott, T. M. C.; Abdalla, F. B.; Allam, S.; Benoit-Lévy, A.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Burke, D. L.; Capozzi, D.; Carnero Rosell, A.; Carrasco Kind, M.; Carretero, J.; Crocce, M.; Cunha, C. E.; D' Andrea, C. B.; da Costa, L. N.; Desai, S.; Dietrich, J. P.; Doel, P.; Estrada, J.; Evrard, A. E.; Flaugher, B.; Frieman, J.; Gerdes, D. W.; Goldstein, D. A.; Gruendl, R. A.; Gutierrez, G.; Honscheid, K.; James, D. J.; Kuehn, K.; Kuropatkin, N.; Li, T. S.; Lima, M.; Maia, M. A. G.; Marshall, J. L.; Miller, C. J.; Miquel, R.; Nord, B.; Ogando, R.; Plazas, A. A.; Roodman, A.; Sanchez, E.; Scarpine, V.; Sevilla-Noarbe, I.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; Tucker, D.; Vikram, V.

    2016-08-20

    We derive the stellar mass fraction in the galaxy cluster RXC J2248.7-4431 observed with the Dark Energy Survey (DES) during the Science Verification period. We compare the stellar mass results from DES (five filters) with those from the Hubble Space Telescope Cluster Lensing And Supernova Survey (CLASH; 17 filters). When the cluster spectroscopic redshift is assumed, we show that stellar masses from DES can be estimated within 25 per cent of CLASH values. We compute the stellar mass contribution coming from red and blue galaxies, and study the relation between stellar mass and the underlying dark matter using weak lensing studies with DES and CLASH. An analysis of the radial profiles of the DES total and stellar mass yields a stellar-to-total fraction of f(star) = (6.8 +/- 1.7) x 10(-3) within a radius of r(200c) similar or equal to 2 Mpc. Our analysis also includes a comparison of photometric redshifts and star/galaxy separation efficiency for both data sets. We conclude that space-based small field imaging can be used to calibrate the galaxy properties in DES for the much wider field of view. The technique developed to derive the stellar mass fraction in galaxy clusters can be applied to the similar to 100 000 clusters that will be observed within this survey and yield important information about galaxy evolution.

  6. The DES Bright Arcs Survey: Hundreds of Candidate Strongly Lensed Galaxy Systems from the Dark Energy Survey Science Verification and Year 1 Observations

    Energy Technology Data Exchange (ETDEWEB)

    Diehl, H. T.; Buckley-Geer, E. J.; Lindgren, K. A.; Nord, B.; Gaitsch, H.; Gaitsch, S.; Lin, H.; Allam, S.; Odden, C.; Pellico, A.; Tucker, D. L.; Kuropatkin, N.; Soares-Santos, M. [Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States); Collett, T. E. [Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth, PO1 3FX (United Kingdom); Furlanetto, C.; Nightingale, J. [University of Nottingham, School of Physics and Astronomy, Nottingham NG7 2RD (United Kingdom); Gill, M. S. S. [SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States); More, A. [Kavli IPMU (WPI), UTIAS, The University of Tokyo, Kashiwa, Chiba 277-8583 (Japan); Costa, L. N. da; Neto, A. Fausti, E-mail: diehl@fnal.gov [Laboratório Interinstitucional de e-Astronomia—LIneA, Rua Gal. José Cristino 77, Rio de Janeiro, RJ—20921-400 (Brazil); Collaboration: DES Collaboration; and others

    2017-09-01

    We report the results of searches for strong gravitational lens systems in the Dark Energy Survey (DES) Science Verification and Year 1 observations. The Science Verification data span approximately 250 sq. deg. with a median i -band limiting magnitude for extended objects (10 σ ) of 23.0. The Year 1 data span approximately 2000 sq. deg. and have an i -band limiting magnitude for extended objects (10 σ ) of 22.9. As these data sets are both wide and deep, they are particularly useful for identifying strong gravitational lens candidates. Potential strong gravitational lens candidate systems were initially identified based on a color and magnitude selection in the DES object catalogs or because the system is at the location of a previously identified galaxy cluster. Cutout images of potential candidates were then visually scanned using an object viewer and numerically ranked according to whether or not we judged them to be likely strong gravitational lens systems. Having scanned nearly 400,000 cutouts, we present 374 candidate strong lens systems, of which 348 are identified for the first time. We provide the R.A. and decl., the magnitudes and photometric properties of the lens and source objects, and the distance (radius) of the source(s) from the lens center for each system.

  7. Dark matter and dark energy

    CERN Multimedia

    Caldwell, Robert

    2009-01-01

    "Observations continue to indicate that the Universe is dominated by invisible components - dark matter and dark energy. Shedding light on this cosmic darkness is a priority for astronomers and physicists" (3 pages)

  8. Dark discrete gauge symmetries

    International Nuclear Information System (INIS)

    Batell, Brian

    2011-01-01

    We investigate scenarios in which dark matter is stabilized by an Abelian Z N discrete gauge symmetry. Models are surveyed according to symmetries and matter content. Multicomponent dark matter arises when N is not prime and Z N contains one or more subgroups. The dark sector interacts with the visible sector through the renormalizable kinetic mixing and Higgs portal operators, and we highlight the basic phenomenology in these scenarios. In particular, multiple species of dark matter can lead to an unconventional nuclear recoil spectrum in direct detection experiments, while the presence of new light states in the dark sector can dramatically affect the decays of the Higgs at the Tevatron and LHC, thus providing a window into the gauge origin of the stability of dark matter.

  9. Redshift distributions of galaxies in the Dark Energy Survey Science Verification shear catalogue and implications for weak lensing

    Energy Technology Data Exchange (ETDEWEB)

    Bonnett, C.; Troxel, M. A.; Hartley, W.; Amara, A.; Leistedt, B.; Becker, M. R.; Bernstein, G. M.; Bridle, S. L.; Bruderer, C.; Busha, M. T.; Carrasco Kind, M.; Childress, M. J.; Castander, F. J.; Chang, C.; Crocce, M.; Davis, T. M.; Eifler, T. F.; Frieman, J.; Gangkofner, C.; Gaztanaga, E.; Glazebrook, K.; Gruen, D.; Kacprzak, T.; King, A.; Kwan, J.; Lahav, O.; Lewis, G.; Lidman, C.; Lin, H.; MacCrann, N.; Miquel, R.; O’Neill, C. R.; Palmese, A.; Peiris, H. V.; Refregier, A.; Rozo, E.; Rykoff, E. S.; Sadeh, I.; Sánchez, C.; Sheldon, E.; Uddin, S.; Wechsler, R. H.; Zuntz, J.; Abbott, T.; Abdalla, F. B.; Allam, S.; Armstrong, R.; Banerji, M.; Bauer, A. H.; Benoit-Lévy, A.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Burke, D. L.; Capozzi, D.; Carnero Rosell, A.; Carretero, J.; Cunha, C. E.; D’Andrea, C. B.; da Costa, L. N.; DePoy, D. L.; Desai, S.; Diehl, H. T.; Dietrich, J. P.; Doel, P.; Fausti Neto, A.; Fernandez, E.; Flaugher, B.; Fosalba, P.; Gerdes, D. W.; Gruendl, R. A.; Honscheid, K.; Jain, B.; James, D. J.; Jarvis, M.; Kim, A. G.; Kuehn, K.; Kuropatkin, N.; Li, T. S.; Lima, M.; Maia, M. A. G.; March, M.; Marshall, J. L.; Martini, P.; Melchior, P.; Miller, C. J.; Neilsen, E.; Nichol, R. C.; Nord, B.; Ogando, R.; Plazas, A. A.; Reil, K.; Romer, A. K.; Roodman, A.; Sako, M.; Sanchez, E.; Santiago, B.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thaler, J.; Thomas, D.; Vikram, V.; Walker, A. R.

    2016-08-01

    We present photometric redshift estimates for galaxies used in the weak lensing analysis of the Dark Energy Survey Science Verification (DES SV) data. Four model- or machine learning-based photometric redshift methods { annz2, bpz calibrated against BCC-U fig simulations, skynet, and tpz { are analysed. For training, calibration, and testing of these methods, we also construct a catalogue of spectroscopically confirmed galaxies matched against DES SV data. The performance of the methods is evalu-ated against the matched spectroscopic catalogue, focusing on metrics relevant for weak lensing analyses, with additional validation against COSMOS photo-zs. From the galaxies in the DES SV shear catalogue, which have mean redshift 0.72 ±0.01 over the range 0:3 < z < 1:3, we construct three tomographic bins with means of z = {0.45; 0.67,1.00g}. These bins each have systematic uncertainties δz ≲ 0.05 in the mean of the fiducial skynet photo-z n(z). We propagate the errors in the redshift distributions through to their impact on cosmological parameters estimated with cosmic shear, and find that they cause shifts in the value of σ8 of approx. 3%. This shift is within the one sigma statistical errors on σ8 for the DES SV shear catalog. We also found that further study of the potential impact of systematic differences on the critical surface density, Σcrit, contained levels of bias safely less than the statistical power of DES SV data. We recommend a final Gaussian prior for the photo-z bias in the mean of n(z) of width 0:05 for each of the three tomographic bins, and show that this is a sufficient bias model for the corresponding cosmology analysis.

  10. Can the periodic spectral modulations observed in 236 Sloan Sky Survey stars be due to dark matter effects?

    Science.gov (United States)

    Tamburini, Fabrizio; Licata, Ignazio

    2017-09-01

    The search for dark matter (DM) is one of the most active and challenging areas of current research. Possible DM candidates are ultralight fields such as axions and weak interacting massive particles (WIMPs). Axions piled up in the center of stars are supposed to generate matter/DM configurations with oscillating geometries at a very rapid frequency, which is a multiple of the axion mass m B (Brito et al (2015); Brito et al (2016)). Borra and Trottier (2016) recently found peculiar ultrafast periodic spectral modulations in 236 main sequence stars in the sample of 2.5 million spectra of galactic halo stars of the Sloan Digital Sky Survey (˜1% of main sequence stars in the F-K spectral range) that were interpreted as optical signals from extraterrestrial civilizations, suggesting them as possible candidates for the search for extraterrestrial intelligence (SETI) program. We argue, instead, that this could be the first indirect evidence of bosonic axion-like DM fields inside main sequence stars, with a stable radiative nucleus, where a stable DM core can be hosted. These oscillations were not observed in earlier stellar spectral classes probably because of the impossibility of starting a stable oscillatory regime due to the presence of chaotic motions in their convective nuclei. The axion mass values, (50< {m}B< 2.4× {10}3) μ {eV}, obtained from the frequency range observed by Borra and Trottier, (0.6070< f< 0.6077) THz, agree with the recent theoretical results from high-temperature lattice quantum chromodynamics (Borsanyi et al (2016); Borsanyi et al (2016b)).

  11. Understanding legacy liabilities

    Energy Technology Data Exchange (ETDEWEB)

    Ossi, G.J. [Venable, LLP (United States)

    2005-08-01

    Among the most immediate issues facing operations with a workforce represented by the United Mine Workers of America (UMWA) are the so-called 'legacy liabilities'. Legacy liabilities fall under two categories: retiree health care and pension. The retiree health benefit obligations fall into two categories; statutory - those created under the Coal Industry Retiree Health Benefit Act of 1992 and contractual - the 1993 Employer Benefit Plan and the Individual Employer Plans. The pension liabilities are more straightforward; there are three different retirement plans in the NBCWA; the UMWA 1950 Pension Plan, the UMWA 1974 Pension Plan and the UMWA Cash Deferred Savings Plan of 1988.

  12. Altmetrics, Legacy Scholarship, and Scholarly Legacy

    Directory of Open Access Journals (Sweden)

    Lauren B. Collister

    2017-10-01

    Full Text Available When using alternative metrics (altmetrics to investigate the impact of a scholar’s work, researchers and librarians are typically cautioned that altmetrics will be less useful for older works of scholarship. This is because it is difficult to collect social media and other attention retroactively, and the numbers will be lower if the work was published before social media marketing and promotion were widely accepted in a field. In this article, we argue that altmetrics can provide useful information about older works in the form of documenting renewed attention to past scholarship as part of a scholar’s legacy. Using the altmetrics profile of the late Dr. Thomas E. Starzl, often referred to as “the father of modern transplantation”, we describe two cases where altmetrics provided information about renewed interest in his works: a controversy about race and genetics that shows the ongoing impact of a particular work, and posthumous remembrances by colleagues which reveal his scholarly legacy.

  13. Subaru weak-lensing survey of dark matter subhalos in the Coma cluster: Subhalo mass function and statistical properties

    Energy Technology Data Exchange (ETDEWEB)

    Okabe, Nobuhiro [Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Futamase, Toshifumi; Kuroshima, Risa [Astronomical Institute, Tohoku University, Sendai 980-8578 (Japan); Kajisawa, Masaru, E-mail: nobuhiro.okabe@ipmu.jp [Research Center for Space and Cosmic Evolution, Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577 (Japan)

    2014-04-01

    We present a 4 deg{sup 2} weak gravitational lensing survey of subhalos in the very nearby Coma cluster using the Subaru/Suprime-Cam. The large apparent size of cluster subhalos allows us to measure the mass of 32 subhalos detected in a model-independent manner, down to the order of 10{sup –3} of the virial mass of the cluster. Weak-lensing mass measurements of these shear-selected subhalos enable us to investigate subhalo properties and the correlation between subhalo masses and galaxy luminosities for the first time. The mean distortion profiles stacked over subhalos show a sharply truncated feature which is well-fitted by a Navarro-Frenk-White (NFW) mass model with the truncation radius, as expected due to tidal destruction by the main cluster. We also found that subhalo masses, truncation radii, and mass-to-light ratios decrease toward the cluster center. The subhalo mass function, dn/dln M {sub sub}, in the range of 2 orders of magnitude in mass, is well described by a single power law or a Schechter function. Best-fit power indices of 1.09{sub −0.32}{sup +0.42} for the former model and 0.99{sub −0.23}{sup +0.34} for the latter, are in remarkable agreement with slopes of ∼0.9-1.0 predicted by the cold dark matter paradigm. The tangential distortion signals in the radial range of 0.02-2 h {sup –1} Mpc from the cluster center show a complex structure which is well described by a composition of three mass components of subhalos, the NFW mass distribution as a smooth component of the main cluster, and a lensing model from a large scale structure behind the cluster. Although the lensing signals are 1 order of magnitude lower than those for clusters at z ∼ 0.2, the total signal-to-noise ratio, S/N = 13.3, is comparable, or higher, because the enormous number of background source galaxies compensates for the low lensing efficiency of the nearby cluster.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-05-16

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

  15. Creating legacy through evaluation

    DEFF Research Database (Denmark)

    Degn, Hans-Peter; Lynghøj, Hanne; Hansen, Louise Ejgod

    is how to stimulate cultural legacy in certain directions through the emphasis of specific values in the strategic objectives and evaluation criteria. Another perspective is how, to whom and for what purpose evaluation results are reported and implemented, and thus how evaluation may affect design, aims...

  16. Dark energy and dark matter

    International Nuclear Information System (INIS)

    Comelli, D.; Pietroni, M.; Riotto, A.

    2003-01-01

    It is a puzzle why the densities of dark matter and dark energy are nearly equal today when they scale so differently during the expansion of the universe. This conundrum may be solved if there is a coupling between the two dark sectors. In this Letter we assume that dark matter is made of cold relics with masses depending exponentially on the scalar field associated to dark energy. Since the dynamics of the system is dominated by an attractor solution, the dark matter particle mass is forced to change with time as to ensure that the ratio between the energy densities of dark matter and dark energy become a constant at late times and one readily realizes that the present-day dark matter abundance is not very sensitive to its value when dark matter particles decouple from the thermal bath. We show that the dependence of the present abundance of cold dark matter on the parameters of the model differs drastically from the familiar results where no connection between dark energy and dark matter is present. In particular, we analyze the case in which the cold dark matter particle is the lightest supersymmetric particle

  17. Dark matters

    International Nuclear Information System (INIS)

    Silk, Joseph

    2010-01-01

    One of the greatest mysteries in the cosmos is that it is mostly dark. That is, not only is the night sky dark, but also most of the matter and the energy in the universe is dark. For every atom visible in planets, stars and galaxies today there exists at least five or six times as much 'Dark Matter' in the universe. Astronomers and particle physicists today are seeking to unravel the nature of this mysterious but pervasive dark matter, which has profoundly influenced the formation of structure in the universe. Dark energy remains even more elusive, as we lack candidate fields that emerge from well established physics. I will describe various attempts to measure dark matter by direct and indirect means, and discuss the prospects for progress in unravelling dark energy.

  18. Search for gamma-ray emission from eight dwarf spheroidal galaxy candidates discovered in year two of Dark Energy Survey with Fermi-LAT data

    Science.gov (United States)

    Li, Shang; Liang, Yun-Feng; Duan, Kai-Kai; Shen, Zhao-Qiang; Huang, Xiaoyuan; Li, Xiang; Fan, Yi-Zhong; Liao, Neng-Hui; Feng, Lei; Chang, Jin

    2016-02-01

    Very recently the Dark Energy Survey (DES) Collaboration has released their second group of dwarf spheroidal (dSph) galaxy candidates. With the publicly available Pass 8 data of Fermi-LAT we search for γ -ray emissions from the directions of these eight newly discovered dSph galaxy candidates. No statistically significant γ -ray signal has been found in the combined analysis of these sources. With the empirically estimated J-factors of these sources, the constraint on the annihilation channel of χ χ →τ+τ- is comparable to the bound set by the joint analysis of fifteen previously known dSphs with kinematically constrained J-factors for the dark matter mass mχ>250 GeV . In the direction of Tucana III (DES J2356-5935), one of the nearest dSph galaxy candidates that is ˜25 kpc away, there is a weak γ -ray signal and its peak test statistic (TS) value for the dark matter annihilation channel χ χ →τ+τ-1 is ≈6.7 at mχ˜15 GeV . The significance of the possible signal likely increases with time. More data is highly needed to pin down the physical origin of such a GeV excess.

  19. THE HUBBLE SPACE TELESCOPE CLUSTER SUPERNOVA SURVEY. V. IMPROVING THE DARK-ENERGY CONSTRAINTS ABOVE z > 1 AND BUILDING AN EARLY-TYPE-HOSTED SUPERNOVA SAMPLE

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, N.; Rubin, D.; Aldering, G.; Barbary, K.; Faccioli, L.; Fakhouri, H. K. [E.O. Lawrence Berkeley National Lab, Berkeley, CA 94720 (United States); Lidman, C. [Australian Astronomical Observatory, Epping, NSW 1710 (Australia); Amanullah, R.; Botyanszki, J. [Department of Physics, University of California Berkeley, Berkeley, CA 94720 (United States); Barrientos, L. F. [Departamento de Astronomia y Astrofisica, Pontificia Universidad Catolica de Chile, Santiago (Chile); Brodwin, M. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Connolly, N. [Department of Physics, Hamilton College, Clinton, NY 13323 (United States); Dawson, K. S. [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States); Dey, A. [National Optical Astronomy Observatory, Tucson, AZ 85726-6732 (United States); Doi, M. [Institute of Astronomy, Graduate School of Science, University of Tokyo 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan); Donahue, M. [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Deustua, S. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Eisenhardt, P. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Ellingson, E. [Center for Astrophysics and Space Astronomy, 389 UCB, University of Colorado, Boulder, CO 80309 (United States); Fadeyev, V., E-mail: nsuzuki@lbl.gov, E-mail: rubind@berkeley.edu, E-mail: clidman@aao.gov.au [Santa Cruz Institute for Particle Physics, University of California Santa Cruz, Santa Cruz, CA 94064 (United States); Collaboration: Supernova Cosmology Project; and others

    2012-02-10

    We present Advanced Camera for Surveys, NICMOS, and Keck adaptive-optics-assisted photometry of 20 Type Ia supernovae (SNe Ia) from the Hubble Space Telescope (HST) Cluster Supernova Survey. The SNe Ia were discovered over the redshift interval 0.623 < z < 1.415. Of these SNe Ia, 14 pass our strict selection cuts and are used in combination with the world's sample of SNe Ia to derive the best current constraints on dark energy. Of our new SNe Ia, 10 are beyond redshift z = 1, thereby nearly doubling the statistical weight of HST-discovered SNe Ia beyond this redshift. Our detailed analysis corrects for the recently identified correlation between SN Ia luminosity and host galaxy mass and corrects the NICMOS zero point at the count rates appropriate for very distant SNe Ia. Adding these SNe improves the best combined constraint on dark-energy density, {rho}{sub DE}(z), at redshifts 1.0 < z < 1.6 by 18% (including systematic errors). For a flat {Lambda}CDM universe, we find {Omega}{sub {Lambda}} = 0.729 {+-} 0.014 (68% confidence level (CL) including systematic errors). For a flat wCDM model, we measure a constant dark-energy equation-of-state parameter w = -1.013{sup +0.068}{sub -0.073} (68% CL). Curvature is constrained to {approx}0.7% in the owCDM model and to {approx}2% in a model in which dark energy is allowed to vary with parameters w{sub 0} and w{sub a} . Further tightening the constraints on the time evolution of dark energy will require several improvements, including high-quality multi-passband photometry of a sample of several dozen z > 1 SNe Ia. We describe how such a sample could be efficiently obtained by targeting cluster fields with WFC3 on board HST. The updated supernova Union2.1 compilation of 580 SNe is available at http://supernova.lbl.gov/Union.

  20. Dark energy

    International Nuclear Information System (INIS)

    Wang, Yun

    2010-01-01

    Dark energy research aims to illuminate the mystery of the observed cosmic acceleration, one of the fundamental problems in physics and astronomy today. This book presents a systematic and detailed review of the current state of dark energy research, with the focus on the examination of the major observational techniques for probing dark energy. It can be used as a textbook to train students and others who wish to enter this extremely active field in cosmology.

  1. Dark stars

    DEFF Research Database (Denmark)

    Maselli, Andrea; Pnigouras, Pantelis; Nielsen, Niklas Grønlund

    2017-01-01

    to the formation of compact objects predominantly made of dark matter. Considering both fermionic and bosonic (scalar φ4) equations of state, we construct the equilibrium structure of rotating dark stars, focusing on their bulk properties and comparing them with baryonic neutron stars. We also show that these dark...... objects admit the I-Love-Q universal relations, which link their moments of inertia, tidal deformabilities, and quadrupole moments. Finally, we prove that stars built with a dark matter equation of state are not compact enough to mimic black holes in general relativity, thus making them distinguishable...

  2. Revisiting Legacy Software System Modernization

    NARCIS (Netherlands)

    Khadka, R.

    2016-01-01

    Legacy software systems are those that significantly resist modification and evolution while still being valuable to its stakeholders to the extent that their failure has a detrimental impact on business. Despite several drawbacks of legacy software systems, they are still being extensively used in

  3. The Sloan Digital Sky Survey Quasar Lens Search. III Constraints on Dark Energy From The Third Data Release Quasar Lens Catalog

    Energy Technology Data Exchange (ETDEWEB)

    Oguri, M; Inada, N; Strauss, M A; Kochanek, C S; Richards, G T; Schneider, D P; Becker, R H; Fukugita, M; Gregg, M D; Hall, P B; Hennawi, J F; Johnston, D E; Kayo, I; Keeton, C R; Pindor, B; Shin, M; Turner, E; White, R L; York, D G; Anderson, S F; Bahcall, N A; Brunner, R J; Burles, S; Castander, F J; Chiu, K; Clocchiatti, A; Einsenstein, D; Frieman, J; Kawano, Y; Lupton, R; Morokuma, T; Rix, H; Scranton, R; Sheldon, E S

    2007-09-12

    We present cosmological results from the statistics of lensed quasars in the Sloan Digital Sky Survey (SDSS) Quasar Lens Search. By taking proper account of the selection function, we compute the expected number of quasars lensed by early-type galaxies and their image separation distribution assuming a flat universe, which is then compared with 7 lenses found in the SDSS Data Release 3 to derive constraints on dark energy under strictly controlled criteria. For a cosmological constant model (w = -1) we obtain {Omega}{sub {Lambda}} = 0.74{sub -0.15}{sup +0.11}(stat.){sub -0.06}{sup +0.13}(syst.). Allowing w to be a free parameter we find {Omega}{sub M} = 0.26{sub -0.06}{sup +0.07}(stat.){sub -0.05}{sup +0.03}(syst.) and w = -1.1 {+-} 0.6(stat.){sub -0.5}{sup +0.3}(syst.) when combined with the constraint from the measurement of baryon acoustic oscillations in the SDSS luminous red galaxy sample. Our results are in good agreement with earlier lensing constraints obtained using radio lenses, and provide additional confirmation of the presence of dark energy consistent with a cosmological constant, derived independently of type Ia supernovae.

  4. Dark matter and dark radiation

    International Nuclear Information System (INIS)

    Ackerman, Lotty; Buckley, Matthew R.; Carroll, Sean M.; Kamionkowski, Marc

    2009-01-01

    We explore the feasibility and astrophysical consequences of a new long-range U(1) gauge field ('dark electromagnetism') that couples only to dark matter, not to the standard model. The dark matter consists of an equal number of positive and negative charges under the new force, but annihilations are suppressed if the dark-matter mass is sufficiently high and the dark fine-structure constant α-circumflex is sufficiently small. The correct relic abundance can be obtained if the dark matter also couples to the conventional weak interactions, and we verify that this is consistent with particle-physics constraints. The primary limit on α-circumflex comes from the demand that the dark matter be effectively collisionless in galactic dynamics, which implies α-circumflex -3 for TeV-scale dark matter. These values are easily compatible with constraints from structure formation and primordial nucleosynthesis. We raise the prospect of interesting new plasma effects in dark-matter dynamics, which remain to be explored.

  5. Dark Matter

    Indian Academy of Sciences (India)

    What You See Ain't What. You Got, Resonance, Vol.4,. No.9,1999. Dark Matter. 2. Dark Matter in the Universe. Bikram Phookun and Biman Nath. In Part 11 of this article we learnt that there are compelling evidences from dynamics of spiral galaxies, like our own, that there must be non-luminous matter in them. In this.

  6. LEGACY MANAGEMENT REQUIRES INFORMATION

    International Nuclear Information System (INIS)

    CONNELL, C.W.; HILDEBRAND, R.D.

    2006-01-01

    ''Legacy Management Requires Information'' describes the goal(s) of the US Department of Energy's Office of Legacy Management (LM) relative to maintaining critical records and the way those goals are being addressed at Hanford. The paper discusses the current practices for document control, as well as the use of modern databases for both storing and accessing the data to support cleanup decisions. In addition to the information goals of LM, the Hanford Federal Facility Agreement and Consent Order, known as the ''Tri-Party Agreement'' (TPA) is one of the main drivers in documentation and data management. The TPA, which specifies discrete milestones for cleaning up the Hanford Site, is a legally binding agreement among the US Department of Energy (DOE), the Washington State Department of Ecology (Ecology), and the US Environmental Protection Agency (EPA). The TPA requires that DOE provide the lead regulatory agency with the results of analytical laboratory and non-laboratory tests/readings to help guide them in making decisions. The Agreement also calls for each signatory to preserve--for at least ten years after the Agreement has ended--all of the records in its or its contractors, possession related to sampling, analysis, investigations, and monitoring conducted. The tools used at Hanford to meet TPA requirements are also the tools that can satisfy the needs of LM

  7. LEGACY MANAGEMENT REQUIRES INFORMATION

    Energy Technology Data Exchange (ETDEWEB)

    CONNELL, C.W.; HILDEBRAND, R.D.

    2006-12-14

    ''Legacy Management Requires Information'' describes the goal(s) of the US Department of Energy's Office of Legacy Management (LM) relative to maintaining critical records and the way those goals are being addressed at Hanford. The paper discusses the current practices for document control, as well as the use of modern databases for both storing and accessing the data to support cleanup decisions. In addition to the information goals of LM, the Hanford Federal Facility Agreement and Consent Order, known as the ''Tri-Party Agreement'' (TPA) is one of the main drivers in documentation and data management. The TPA, which specifies discrete milestones for cleaning up the Hanford Site, is a legally binding agreement among the US Department of Energy (DOE), the Washington State Department of Ecology (Ecology), and the US Environmental Protection Agency (EPA). The TPA requires that DOE provide the lead regulatory agency with the results of analytical laboratory and non-laboratory tests/readings to help guide them in making decisions. The Agreement also calls for each signatory to preserve--for at least ten years after the Agreement has ended--all of the records in its or its contractors, possession related to sampling, analysis, investigations, and monitoring conducted. The tools used at Hanford to meet TPA requirements are also the tools that can satisfy the needs of LM.

  8. Extinctions and Distances to Dark Clouds from 2MASS, MegaCam and IPHAS Surveys: LDN 1525 in the Direction of the Aur OB1 Association

    Directory of Open Access Journals (Sweden)

    Straižys V.

    2010-12-01

    Full Text Available The possibility of applying photometry from the 2MASS J, H, Ks, MegaCam u, g and IPHAS r, i, Hα surveys for determining the distance to the dark cloud LDN1525 (TGU 1192 in the direction of the Aur OB1 association is investigated using the red clump giants. The main dust cloud, probably related to the emission nebulae Sh 2-232, Sh 2-233, Sh 2-235, the molecular cloud and the association Aur OB2, is found to be located at a distance of 1.3 kpc from the Sun. The nebula Sh 2-231 can be an object of the Perseus arm. The maximum extinction AV found in the cloud is close to 6 mag.

  9. Dark Energy Survey Year 1 Results: Cross-Correlation Redshifts in the DES -- Calibration of the Weak Lensing Source Redshift Distributions

    Energy Technology Data Exchange (ETDEWEB)

    Davis, C.; et al.

    2017-10-06

    We present the calibration of the Dark Energy Survey Year 1 (DES Y1) weak lensing source galaxy redshift distributions from clustering measurements. By cross-correlating the positions of source galaxies with luminous red galaxies selected by the redMaGiC algorithm we measure the redshift distributions of the source galaxies as placed into different tomographic bins. These measurements constrain any such shifts to an accuracy of $\\sim0.02$ and can be computed even when the clustering measurements do not span the full redshift range. The highest-redshift source bin is not constrained by the clustering measurements because of the minimal redshift overlap with the redMaGiC galaxies. We compare our constraints with those obtained from $\\texttt{COSMOS}$ 30-band photometry and find that our two very different methods produce consistent constraints.

  10. Dark Energy Survey Year 1 Results: Calibration of redMaGiC Redshift Distributions in DES and SDSS from Cross-Correlations

    Energy Technology Data Exchange (ETDEWEB)

    Cawthon, R.; et al.

    2017-12-19

    We present calibrations of the redshift distributions of redMaGiC galaxies in the Dark Energy Survey Year 1 (DES Y1) and Sloan Digital Sky Survey (SDSS) DR8 data. These results determine the priors of the redshift distribution of redMaGiC galaxies, which were used for galaxy clustering measurements and as lenses for galaxy-galaxy lensing measurements in DES Y1 cosmological analyses. We empirically determine the bias in redMaGiC photometric redshift estimates using angular cross-correlations with Baryon Oscillation Spectroscopic Survey (BOSS) galaxies. For DES, we calibrate a single parameter redshift bias in three photometric redshift bins: $z \\in[0.15,0.3]$, [0.3,0.45], and [0.45,0.6]. Our best fit results in each bin give photometric redshift biases of $|\\Delta z|<0.01$. To further test the redMaGiC algorithm, we apply our calibration procedure to SDSS redMaGiC galaxies, where the statistical precision of the cross-correlation measurement is much higher due to a greater overlap with BOSS galaxies. For SDSS, we also find best fit results of $|\\Delta z|<0.01$. We compare our results to other analyses of redMaGiC photometric redshifts.

  11. Dark Energy Survey Year 1 Results: Methodology and Projections for Joint Analysis of Galaxy Clustering, Galaxy Lensing, and CMB Lensing Two-point Functions

    Energy Technology Data Exchange (ETDEWEB)

    Giannantonio, T.; et al.

    2018-02-14

    Optical imaging surveys measure both the galaxy density and the gravitational lensing-induced shear fields across the sky. Recently, the Dark Energy Survey (DES) collaboration used a joint fit to two-point correlations between these observables to place tight constraints on cosmology (DES Collaboration et al. 2017). In this work, we develop the methodology to extend the DES Collaboration et al. (2017) analysis to include cross-correlations of the optical survey observables with gravitational lensing of the cosmic microwave background (CMB) as measured by the South Pole Telescope (SPT) and Planck. Using simulated analyses, we show how the resulting set of five two-point functions increases the robustness of the cosmological constraints to systematic errors in galaxy lensing shear calibration. Additionally, we show that contamination of the SPT+Planck CMB lensing map by the thermal Sunyaev-Zel'dovich effect is a potentially large source of systematic error for two-point function analyses, but show that it can be reduced to acceptable levels in our analysis by masking clusters of galaxies and imposing angular scale cuts on the two-point functions. The methodology developed here will be applied to the analysis of data from the DES, the SPT, and Planck in a companion work.

  12. The Legacy of Radium ...

    Indian Academy of Sciences (India)

    Show any person any thing that fluoresces in the dark and ask what it is. Snap comes the reply 'Radium'. In most cases it is not radium. Most people have not seen radium and even fewer have ever handled it. But this testifies the extent to which radium has remained a household word· even a century after its discovery.

  13. THE HUBBLE SPACE TELESCOPE UV LEGACY SURVEY OF GALACTIC GLOBULAR CLUSTERS. VII. IMPLICATIONS FROM THE NEARLY UNIVERSAL NATURE OF HORIZONTAL BRANCH DISCONTINUITIES

    Energy Technology Data Exchange (ETDEWEB)

    Brown, T. M.; Bellini, A.; Anderson, J. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Cassisi, S.; Pietrinferni, A. [INAF-Osservatorio Astronomico di Teramo, Via Mentore Maggini s.n.c., I-64100 Teramo (Italy); D’Antona, F. [INAF-Osservatorio Astronomico di Roma, Via Frascati 33, I-00040 Monteporzio Catone, Roma (Italy); Salaris, M. [Astrophysics Research Institute,Liverpool John Moores University, Liverpool Science Park, IC2 Building, 146 Brownlow Hill, Liverpool L3 5RF (United Kingdom); Milone, A. P. [Research School of Astronomy and Astrophysics, The Australian National University, Cotter Road, Weston, ACT, 2611 (Australia); Dalessandro, E. [Dipartimento di Fisica e Astronomia, Università degli Studi di Bologna, Viale Berti Pichat 6/2, I-40127 Bologna (Italy); Piotto, G.; Ortolani, S.; Nardiello, D. [Dipartimento di Fisica e Astronomia “Galileo Galilei,”Università di Padova, Vicolo dell’Osservatorio 3, I-35122 Padova (Italy); Renzini, A.; Bedin, L. R. [INAF-Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, I-35122 Padova (Italy); Sweigart, A. V. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Sarajedini, A. [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611 (United States); Aparicio, A., E-mail: tbrown@stsci.edu, E-mail: jayander@stsci, E-mail: bellini@stsci.edu, E-mail: cassisi@oa-teramo.inaf.it, E-mail: pietrinferni@oa-teramo.inaf.it, E-mail: dantona@oa-roma.inaf.it, E-mail: M.Salaris@ljmu.ac.uk, E-mail: milone@mso.anu.edu.au [Instituto de Astrofísica de Canarias. Calle Vía Láctea s/n. E38200 — La Laguna, Tenerife, Canary Islands (Spain)

    2016-05-01

    The UV-initiative Hubble Space Telescope Treasury survey of Galactic globular clusters provides a new window into the phenomena that shape the morphological features of the horizontal branch (HB). Using this large and homogeneous catalog of UV and blue photometry, we demonstrate that the HB exhibits discontinuities that are remarkably consistent in color (effective temperature). This consistency is apparent even among some of the most massive clusters hosting multiple distinct sub-populations (such as NGC 2808, ω Cen, and NGC 6715), demonstrating that these phenomena are primarily driven by atmospheric physics that is independent of the underlying population properties. However, inconsistencies arise in the metal-rich clusters NGC 6388 and NGC 6441, where the discontinuity within the blue HB (BHB) distribution shifts ∼1000–2000 K hotter. We demonstrate that this shift is likely due to a large helium enhancement in the BHB stars of these clusters, which in turn affects the surface convection and evolution of such stars. Our survey also increases the number of Galactic globular clusters known to host blue-hook stars (also known as late hot flashers) from 6 to 23 clusters. These clusters are biased toward the bright end of the globular cluster luminosity function, confirming that blue-hook stars tend to form in the most massive clusters with significant self-enrichment.

  14. A WISE View of Almost Dark ALFALFA Galaxies

    Science.gov (United States)

    Pérez, Jonathan; Arrieta, A.; Pantoja, C.; Lebron, M. E.; Leisman, L.; Koopmann, R. A.; Haynes, M. P.

    2014-01-01

    Dark galaxies are galaxies that have few stars and are made mostly of dense gas. These objects are expected to be difficult to detect with optical telescopes. Dark galaxies are thought to exist possibly associated to tidal interactions between galaxies, or they might represent an early stage in the process of galaxy formation. The prototype for dark galaxies is the southwestern component of HI 1225+01 (Chengalur et al. 1995, AJ 109, 2415) with an HI mass of 8*10^8M⊙ circular velocity ~34 km/s. The Arecibo Legacy Fast ALFA extragalactic survey (ALFALFA) is a blind HI survey completed in 2012. One of the scientific objectives of ALFALFA was the possible detection of HI tidal remnants (Giovanelli et al. 2005, AJ 130, 2598). Less than 2% of the total extragalactic population of the α.40 Source Catalog from ALFALFA are classified as dark HI sources (Haynes et al. 2011, AJ. 142,170). As part of our participation of the Undergraduate ALFALFA Team we present an analysis of the infrared data from WISE of a sample of the most extreme high M_HI/ almost dark galaxies being studied by the ALFALFA team. Some of these objects have no detectable optical emission in SDSS images, while others may be associated with very faint, low luminosity stellar counterparts. For HI 1225+01, Matsuoka et al (2012, AJ 144,159) obtained an R band image of the NE clump of this object, and also found emission in the Spitzer IRAC bands of 3.6μm and 4.5μm among others. No emission was found In the SW component. We present our findings of the emission at 3.4, 4.6 and 12μm from WISE of a region centered on the almost dark galaxies. This research has made use of the NASA/IPAC Infrared Science Archive, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. We gratefully acknowledge the support from the NSF grant AST-1211005 for this project.

  15. Colorism, a Legacy of Historical Trauma in Parent-Child Relationships: Clinical, Research, and Personal Perspectives

    Science.gov (United States)

    Lewis, Marva L.; Noroña, Carmen Rosa; McConnico, Neena; Thomas, Kandace

    2013-01-01

    Practitioners need to be aware of the intergenerational transmission of historical trauma in families with young children. One legacy of historical trauma, "colorism"--valuing light skin over dark skin--occurs among many oppressed indigenous, ethnic, racial, and cultural groups around the world. The unconscious hierarchy and privilege…

  16. Dark coupling

    International Nuclear Information System (INIS)

    Gavela, M.B.; Hernández, D.; Honorez, L. Lopez; Mena, O.; Rigolin, S.

    2009-01-01

    The two dark sectors of the universe—dark matter and dark energy—may interact with each other. Background and linear density perturbation evolution equations are developed for a generic coupling. We then establish the general conditions necessary to obtain models free from non-adiabatic instabilities. As an application, we consider a viable universe in which the interaction strength is proportional to the dark energy density. The scenario does not exhibit ''phantom crossing'' and is free from instabilities, including early ones. A sizeable interaction strength is compatible with combined WMAP, HST, SN, LSS and H(z) data. Neutrino mass and/or cosmic curvature are allowed to be larger than in non-interacting models. Our analysis sheds light as well on unstable scenarios previously proposed

  17. Effects of time-varying β in SNLS3 on constraining interacting dark energy models

    International Nuclear Information System (INIS)

    Wang, Shuang; Wang, Yong-Zhen; Geng, Jia-Jia; Zhang, Xin

    2014-01-01

    It has been found that, for the Supernova Legacy Survey three-year (SNLS3) data, there is strong evidence for the redshift evolution of the color-luminosity parameter β. In this paper, adopting the w-cold-dark-matter (wCDM) model and considering its interacting extensions (with three kinds of interaction between dark sectors), we explore the evolution of β and its effects on parameter estimation. In addition to the SNLS3 data, we also use the latest Planck distance priors data, the galaxy clustering data extracted from sloan digital sky survey data release 7 and baryon oscillation spectroscopic survey, as well as the direct measurement of Hubble constant H 0 from the Hubble Space Telescope observation. We find that, for all the interacting dark energy (IDE) models, adding a parameter of β can reduce χ 2 by ∝34, indicating that a constant β is ruled out at 5.8σ confidence level. Furthermore, it is found that varying β can significantly change the fitting results of various cosmological parameters: for all the dark energy models considered in this paper, varying β yields a larger fractional CDM densities Ω c0 and a larger equation of state w; on the other side, varying β yields a smaller reduced Hubble constant h for the wCDM model, but it has no impact on h for the three IDE models. This implies that there is a degeneracy between h and coupling parameter γ. Our work shows that the evolution of β is insensitive to the interaction between dark sectors, and then highlights the importance of considering β's evolution in the cosmology fits. (orig.)

  18. The Lenses Structure and Dynamics Survey: luminous and dark matter in high redshift early-type galaxies

    NARCIS (Netherlands)

    Treu, T.; Koopmans, L.

    2003-01-01

    I will present the latest results from the Lenses Structure and Dynamics (LSD) Survey. Using ESI on the Keck Telescope, we have measured spatially resolved stellar kinematics for a sample of 11 early-type galaxies (E/S0s) in the range z=0.1-1, selected as gravitational lenses. By combining lensing

  19. Dark Matter

    Science.gov (United States)

    Lincoln, Don

    2013-01-01

    It's a dark, dark universe out there, and I don't mean because the night sky is black. After all, once you leave the shadow of the Earth and get out into space, you're surrounded by countless lights glittering everywhere you look. But for all of Sagan's billions and billions of stars and galaxies, it's a jaw-dropping fact that the ordinary kind of…

  20. The SCUBA-2 Cosmology Legacy Survey: the EGS deep field - I. Deep number counts and the redshift distribution of the recovered cosmic infrared background at 450 and 850 μ m

    Science.gov (United States)

    Zavala, J. A.; Aretxaga, I.; Geach, J. E.; Hughes, D. H.; Birkinshaw, M.; Chapin, E.; Chapman, S.; Chen, Chian-Chou; Clements, D. L.; Dunlop, J. S.; Farrah, D.; Ivison, R. J.; Jenness, T.; Michałowski, M. J.; Robson, E. I.; Scott, Douglas; Simpson, J.; Spaans, M.; van der Werf, P.

    2017-01-01

    We present deep observations at 450 and 850 μm in the Extended Groth Strip field taken with the SCUBA-2 camera mounted on the James Clerk Maxwell Telescope as part of the deep SCUBA-2 Cosmology Legacy Survey (S2CLS), achieving a central instrumental depth of σ450 = 1.2 mJy beam-1 and σ850 = 0.2 mJy beam-1. We detect 57 sources at 450 μm and 90 at 850 μm with signal-to-noise ratio >3.5 over ˜70 arcmin2. From these detections, we derive the number counts at flux densities S450 > 4.0 mJy and S850 > 0.9 mJy, which represent the deepest number counts at these wavelengths derived using directly extracted sources from only blank-field observations with a single-dish telescope. Our measurements smoothly connect the gap between previous shallower blank-field single-dish observations and deep interferometric ALMA results. We estimate the contribution of our SCUBA-2 detected galaxies to the cosmic infrared background (CIB), as well as the contribution of 24 μm-selected galaxies through a stacking technique, which add a total of 0.26 ± 0.03 and 0.07 ± 0.01 MJy sr-1, at 450 and 850 μm, respectively. These surface brightnesses correspond to 60 ± 20 and 50 ± 20 per cent of the total CIB measurements, where the errors are dominated by those of the total CIB. Using the photometric redshifts of the 24 μm-selected sample and the redshift distributions of the submillimetre galaxies, we find that the redshift distribution of the recovered CIB is different at each wavelength, with a peak at z ˜ 1 for 450 μm and at z ˜ 2 for 850 μm, consistent with previous observations and theoretical models.

  1. Eight New Luminous z > 6 Quasars Selected via SED Model Fitting of VISTA, WISE and Dark Energy Survey Year 1 Observations

    Energy Technology Data Exchange (ETDEWEB)

    Reed, S.L.; et al.

    2017-01-17

    We present the discovery and spectroscopic confirmation with the ESO NTT and Gemini South telescopes of eight new 6.0 < z < 6.5 quasars with z$_{AB}$ < 21.0. These quasars were photometrically selected without any star-galaxy morphological criteria from 1533 deg$^{2}$ using SED model fitting to photometric data from the Dark Energy Survey (g, r, i, z, Y), the VISTA Hemisphere Survey (J, H, K) and the Wide-Field Infrared Survey Explorer (W1, W2). The photometric data was fitted with a grid of quasar model SEDs with redshift dependent Lyman-{\\alpha} forest absorption and a range of intrinsic reddening as well as a series of low mass cool star models. Candidates were ranked using on a SED-model based $\\chi^{2}$-statistic, which is extendable to other future imaging surveys (e.g. LSST, Euclid). Our spectral confirmation success rate is 100% without the need for follow-up photometric observations as used in other studies of this type. Combined with automatic removal of the main types of non-astrophysical contaminants the method allows large data sets to be processed without human intervention and without being over run by spurious false candidates. We also present a robust parametric redshift estimating technique that gives comparable accuracy to MgII and CO based redshift estimators. We find two z $\\sim$ 6.2 quasars with HII near zone sizes < 3 proper Mpc which could indicate that these quasars may be young with ages < 10$^6$ - 10$^7$ years or lie in over dense regions of the IGM. The z = 6.5 quasar VDESJ0224-4711 has J$_{AB}$ = 19.75 is the second most luminous quasar known with z > 6.5.

  2. Eight new luminous z ≥ 6 quasars discovered via SED model fitting of VISTA, WISE and Dark Energy Survey Year 1 observations

    Science.gov (United States)

    Reed, S. L.; McMahon, R. G.; Martini, P.; Banerji, M.; Auger, M.; Hewett, P. C.; Koposov, S. E.; Gibbons, S. L. J.; Gonzalez-Solares, E.; Ostrovski, F.; Tie, S. S.; Abdalla, F. B.; Allam, S.; Benoit-Lévy, A.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Burke, D. L.; Carnero Rosell, A.; Carrasco Kind, M.; Carretero, J.; da Costa, L. N.; DePoy, D. L.; Desai, S.; Diehl, H. T.; Doel, P.; Evrard, A. E.; Finley, D. A.; Flaugher, B.; Fosalba, P.; Frieman, J.; García-Bellido, J.; Gaztanaga, E.; Goldstein, D. A.; Gruen, D.; Gruendl, R. A.; Gutierrez, G.; James, D. J.; Kuehn, K.; Kuropatkin, N.; Lahav, O.; Lima, M.; Maia, M. A. G.; Marshall, J. L.; Melchior, P.; Miller, C. J.; Miquel, R.; Nord, B.; Ogando, R.; Plazas, A. A.; Romer, A. K.; Sanchez, E.; Scarpine, V.; Schubnell, M.; Sevilla-Noarbe, I.; Smith, R. C.; Sobreira, F.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Tucker, D. L.; Walker, A. R.; Wester, W.

    2017-07-01

    We present the discovery and spectroscopic confirmation with the European Southern Observatory New Technology Telescope (NTT) and Gemini South telescopes of eight new, and the rediscovery of two previously known, 6.0 energy distribution (SED) model fitting to photometric data from Dark Energy Survey (g, r, I, z, Y), VISTA Hemisphere Survey (J, H, K) and Wide-field Infrared Survey Explorer (W1, W2). The photometric data were fitted with a grid of quasar model SEDs with redshift-dependent Ly α forest absorption and a range of intrinsic reddening as well as a series of low-mass cool star models. Candidates were ranked using an SED-model-based χ2-statistic, which is extendable to other future imaging surveys (e.g. LSST and Euclid). Our spectral confirmation success rate is 100 per cent without the need for follow-up photometric observations as used in other studies of this type. Combined with automatic removal of the main types of non-astrophysical contaminants, the method allows large data sets to be processed without human intervention and without being overrun by spurious false candidates. We also present a robust parametric redshift estimator that gives comparable accuracy to Mg II and CO-based redshift estimators. We find two z ˜ 6.2 quasars with H II near zone sizes ≤3 proper Mpc that could indicate that these quasars may be young with ages ≲ 106-107 years or lie in over dense regions of the IGM. The z = 6.5 quasar VDES J0224-4711 has JAB = 19.75 and is the second most luminous quasar known with z ≥ 6.5.

  3. WORLD CUP LEGACY AND PERTAINING IMPACTS ON SÃO PAULO CITY´S FUTURE

    Directory of Open Access Journals (Sweden)

    Marcos Vinicius Cardoso

    2013-08-01

    Full Text Available Legacies – structures that are built for events and which remain after the same - are one of the major positive aspects paraded by mega sporting events organizers. This study´s purpose is to analyze the current situation of legacies promised by the many governmental instances for the city of São Paulo - host city of Fifa´s 2014 World Cup – and prospect which legacies will become effective in the city. Preliminary assessments may raise construction concerns, alert the public to keep an eye on undertaken obligations and encourage official actions (Mangan, 2008, p. 1,871. Data was obtained from National Audit Court (TCU reports, Ministry and United Nations documents, in addition to testimonials and information gathered from some of Brazil´s major press media. Data analysis was conducted by classifying legacies according to tangible and intangible legacy concepts (Kaplanidou and Karadakis, 2010 followed by an analysis of promised legacies versus current status during the period of analysis. Finally, discussions as to most probable to come about legacies were presented. Results indicate that a portion of promised legacies stand a fair chance of achievement. On the other hand, other projects lag behind schedule or have been cancelled. Preliminary surveys suggest full completion of promised legacies is not possible, there has been an overuse of public resources as opposed to that planned, and provide indicatives as to the investment´s high opportunity cost.

  4. The DECam Minute Cadence Survey

    Science.gov (United States)

    Belardi, C.; Kilic, M.; Munn, J. A.; Gianninas, A.; Barber, S. D.; Dey, A.; Stetson, P. B.

    2017-03-01

    We present the first results from a minute cadence survey of a 3 deg2 field obtained with the Dark Energy Camera. We imaged part of the Canada- France-Hawaii Telescope Legacy Survey area over eight half-nights. We use the stacked images to identify 111 high proper motion white dwarf candidates with g≤ 24.5 mag and search for eclipse-like events and other sources of variability. We find a new g=20.64 mag pulsating ZZ Ceti star with pulsation periods of 11-13 min. However, we do not find any transiting planetary companions in the habitable zone of our target white dwarfs. Given the probability of eclipses of 1% and our observing window from the ground, the non-detection of such companions in this first field is not surprising. Minute cadence DECam observations of additional fields will provide stringent constraints on the frequency of planets in the white dwarf habitable zone.

  5. Till Moritz Karbach, Scientific Legacy

    CERN Document Server

    Aaij, Roel; Adinolfi, Marco; Affolder, Anthony; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Anderson, Jonathan; Andreassi, Guido; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Aquines Gutierrez, Osvaldo; Archilli, Flavio; d'Argent, Philippe; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Batozskaya, Varvara; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Bel, Lennaert; Bellee, Violaine; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Benton, Jack; Berezhnoy, Alexander; Bernet, Roland; Bertolin, Alessandro; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bien, Alexander; Bifani, Simone; Bird, Thomas; Birnkraut, Alex; Bizzeti, Andrea; Blake, Thomas; Blanc, Frédéric; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Borghi, Silvia; Borsato, Martino; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Braun, Svende; Brett, David; Britsch, Markward; Britton, Thomas; Brodzicka, Jolanta; Brook, Nicholas; Bursche, Albert; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Calvi, Marta; Calvo Gomez, Miriam; Campana, Pierluigi; Campora Perez, Daniel; Capriotti, Lorenzo; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carniti, Paolo; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cauet, Christophe; Cavallero, Giovanni; Cenci, Riccardo; Charles, Matthew; Charpentier, Philippe; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu-Faye; Chiapolini, Nicola; Chrzaszcz, Marcin; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cogoni, Violetta; Cojocariu, Lucian; Collazuol, Gianmaria; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coombes, Matthew; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Crocombe, Andrew; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Dalseno, Jeremy; David, Pieter; Davis, Adam; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Silva, Weeraddana; De Simone, Patrizia; Dean, Cameron Thomas; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Déléage, Nicolas; Demmer, Moritz; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Dey, Biplab; Di Canto, Angelo; Di Ruscio, Francesco; Dijkstra, Hans; Donleavy, Stephanie; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Dossett, David; Dovbnya, Anatoliy; Dreimanis, Karlis; Dufour, Laurent; Dujany, Giulio; Dupertuis, Frederic; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; Easo, Sajan; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; El Rifai, Ibrahim; Elsasser, Christian; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Färber, Christian; Farinelli, Chiara; Farley, Nathanael; Farry, Stephen; Fay, Robert; Ferguson, Dianne; Fernandez Albor, Victor; Ferrari, Fabio; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fohl, Klaus; Fol, Philip; Fontana, Marianna; Fontanelli, Flavio; Forty, Roger; Francisco, Oscar; Frank, Markus; Frei, Christoph; Frosini, Maddalena; Fu, Jinlin; Furfaro, Emiliano; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; García Pardiñas, Julián; Garra Tico, Jordi; Garrido, Lluis; Gascon, David; Gaspar, Clara; Gastaldi, Ugo; Gauld, Rhorry; Gavardi, Laura; Gazzoni, Giulio; Geraci, Angelo; Gerick, David; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianelle, Alessio; Gianì, Sebastiana; Gibson, Valerie; Girard, Olivier Göran; Giubega, Lavinia-Helena; Gligorov, Vladimir; Göbel, Carla; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gotti, Claudio; Grabalosa Gándara, Marc; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graverini, Elena; Graziani, Giacomo; Grecu, Alexandru; Greening, Edward; Gregson, Sam; Griffith, Peter; Grillo, Lucia; Grünberg, Oliver; Gui, Bin; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Hadavizadeh, Thomas; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hall, Samuel; Hamilton, Brian; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; He, Jibo; Head, Timothy; Heijne, Veerle; Hennessy, Karol; Henrard, Pierre; Henry, Louis; Hernando Morata, Jose Angel; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hoballah, Mostafa; Hombach, Christoph; Hulsbergen, Wouter; Humair, Thibaud; Hussain, Nazim; Hutchcroft, David; Hynds, Daniel; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jaeger, Andreas; Jalocha, Pawel; Jans, Eddy; Jawahery, Abolhassan; Jing, Fanfan; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kandybei, Sergii; Kanso, Walaa; Karacson, Matthias; Karodia, Sarah; Kelsey, Matthew; Kenyon, Ian; Kenzie, Matthew; Ketel, Tjeerd; Khanji, Basem; Khurewathanakul, Chitsanu; Klaver, Suzanne; Klimaszewski, Konrad; Kochebina, Olga; Kolpin, Michael; Komarov, Ilya; Koopman, Rose; Koppenburg, Patrick; Korolev, Mikhail; Kozeiha, Mohamad; Kravchuk, Leonid; Kreplin, Katharina; Kreps, Michal; Krocker, Georg; Krokovny, Pavel; Kruse, Florian; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kuonen, Axel Kevin; Kurek, Krzysztof; Kvaratskheliya, Tengiz; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lambert, Dean; Lambert, Robert W; Lanfranchi, Gaia; Langenbruch, Christoph; Langhans, Benedikt; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; van Leerdam, Jeroen; Lees, Jean-Pierre; Lefèvre, Regis; Leflat, Alexander; Lefrançois, Jacques; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Yiming; Likhomanenko, Tatiana; Liles, Myfanwy; Lindner, Rolf; Linn, Christian; Lionetto, Federica; Liu, Bo; Liu, Xuesong; Loh, David; Lohn, Stefan; Longstaff, Iain; Lopes, Jose; Lowdon, Peter; Lucchesi, Donatella; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Machefert, Frederic; Maciuc, Florin; Maev, Oleg; Maguire, Kevin; Malde, Sneha; Malinin, Alexander; Manca, Giulia; Mancinelli, Giampiero; Manning, Peter Michael; Mapelli, Alessandro; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marino, Pietro; Märki, Raphael; Marks, Jörg; Martellotti, Giuseppe; Martin, Morgan; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massafferri, André; Matev, Rosen; Mathad, Abhijit; Mathe, Zoltan; Matteuzzi, Clara; Mauri, Andrea; Maurin, Brice; Mazurov, Alexander; McCann, Michael; McCarthy, James; McNab, Andrew; McNulty, Ronan; Meadows, Brian; Meier, Frank; Meissner, Marco; Melnychuk, Dmytro; Merk, Marcel; Milanes, Diego Alejandro; Minard, Marie-Noelle; Mitzel, Dominik Stefan; Molina Rodriguez, Josue; Monteil, Stephane; Morandin, Mauro; Morawski, Piotr; Mordà, Alessandro; Morello, Michael Joseph; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Müller, Janine; Müller, Katharina; Müller, Vanessa; Mussini, Manuel; Muster, Bastien; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nandi, Anita; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Anh Duc; Nguyen, Thi-Dung; Nguyen-Mau, Chung; Niess, Valentin; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Ninci, Daniele; Novoselov, Alexey; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Ogilvy, Stephen; Okhrimenko, Oleksandr; Oldeman, Rudolf; Onderwater, Gerco; Osorio Rodrigues, Bruno; Otalora Goicochea, Juan Martin; Otto, Adam; Owen, Patrick; Oyanguren, Maria Aranzazu; Palano, Antimo; Palombo, Fernando; Palutan, Matteo; Panman, Jacob; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Pappenheimer, Cheryl; Parkes, Christopher; Passaleva, Giovanni; Patel, Girish; Patel, Mitesh; Patrignani, Claudia; Pearce, Alex; Pellegrino, Antonio; Penso, Gianni; Pepe Altarelli, Monica; Perazzini, Stefano; Perret, Pascal; Pescatore, Luca; Petridis, Konstantinos; Petrolini, Alessandro; Petruzzo, Marco; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pilař, Tomas; Pinci, Davide; Pistone, Alessandro; Piucci, Alessio; Playfer, Stephen; Plo Casasus, Maximo; Poikela, Tuomas; Polci, Francesco; Poluektov, Anton; Polyakov, Ivan; Polycarpo, Erica; Popov, Alexander; Popov, Dmitry; Popovici, Bogdan; Potterat, Cédric; Price, Eugenia; Price, Joseph David; Prisciandaro, Jessica; Pritchard, Adrian; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Punzi, Giovanni; Qian, Wenbin; Quagliani, Renato; Rachwal, Bartolomiej; Rademacker, Jonas; Rama, Matteo; Rangel, Murilo; Raniuk, Iurii; Rauschmayr, Nathalie; Raven, Gerhard; Redi, Federico; Reichert, Stefanie; Reid, Matthew; dos Reis, Alberto; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Rives Molina, Vincente; Robbe, Patrick; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Lopez, Jairo Alexis; Rodriguez Perez, Pablo; Roiser, Stefan; Romanovsky, Vladimir; Romero Vidal, Antonio; Ronayne, John William; Rotondo, Marcello; Rouvinet, Julien; Ruf, Thomas; Ruiz, Hugo; Ruiz Valls, Pablo; Saborido Silva, Juan Jose; Sagidova, Naylya; Sail, Paul; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santimaria, Marco; Santovetti, Emanuele; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrina, Darya; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmelzer, Timon; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schubiger, Maxime; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Semennikov, Alexander; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Shires, Alexander; Silva Coutinho, Rafael; Simi, Gabriele; Sirendi, Marek; Skidmore, Nicola; Skillicorn, Ian; Skwarnicki, Tomasz; Smith, Edmund; Smith, Eluned; Smith, Iwan Thomas; Smith, Jackson; Smith, Mark; Snoek, Hella; Sokoloff, Michael; Soler, Paul; Soomro, Fatima; Souza, Daniel; Souza De Paula, Bruno; Spaan, Bernhard; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Steinkamp, Olaf; Stenyakin, Oleg; Sterpka, Christopher Francis; Stevenson, Scott; Stoica, Sabin; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Straticiuc, Mihai; Straumann, Ulrich; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Swientek, Stefan; Syropoulos, Vasileios; Szczekowski, Marek; Szczypka, Paul; Szumlak, Tomasz; T'Jampens, Stephane; Tekampe, Tobias; Teklishyn, Maksym; Tellarini, Giulia; Teubert, Frederic; Thomas, Christopher; Thomas, Eric; van Tilburg, Jeroen; Tisserand, Vincent; Tobin, Mark; Todd, Jacob; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Topp-Joergensen, Stig; Torr, Nicholas; Tournefier, Edwige; Tourneur, Stephane; Trabelsi, Karim; Tran, Minh Tâm; Tresch, Marco; Trisovic, Ana; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tuning, Niels; Ukleja, Artur; Ustyuzhanin, Andrey; Uwer, Ulrich; Vacca, Claudia; Vagnoni, Vincenzo; Valenti, Giovanni; Vallier, Alexis; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vázquez Sierra, Carlos; Vecchi, Stefania; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Vesterinen, Mika; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Vilasis-Cardona, Xavier; Vollhardt, Achim; Volyanskyy, Dmytro; Voong, David; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; de Vries, Jacco; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wandernoth, Sebastian; Wang, Jianchun; Ward, David; Watson, Nigel; Websdale, David; Weiden, Andreas; Whitehead, Mark; Wiedner, Dirk; Wilkinson, Guy; Wilkinson, Michael; Williams, Mark Richard James; Williams, Matthew; Williams, Mike; Williams, Timothy; Wilson, Fergus; Wimberley, Jack; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wright, Simon; Wyllie, Kenneth; Xie, Yuehong; Xu, Zhirui; Yang, Zhenwei; Yu, Jiesheng; Yuan, Xuhao; Yushchenko, Oleg; Zangoli, Maria; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Yanxi; Zhelezov, Alexey; Zhokhov, Anatoly; Zhong, Liang

    2015-01-01

    We are deeply touched by the sudden loss of our dear friend and colleague Till Moritz Karbach. With this memorial book we wish to commemorate Moritz’ scientific legacy, and what Moritz meant to us as a friend.

  6. LeMMINGs - I. The eMERLIN legacy survey of nearby galaxies. 1.5-GHz parsec-scale radio structures and cores

    Science.gov (United States)

    Baldi, R. D.; Williams, D. R. A.; McHardy, I. M.; Beswick, R. J.; Argo, M. K.; Dullo, B. T.; Knapen, J. H.; Brinks, E.; Muxlow, T. W. B.; Aalto, S.; Alberdi, A.; Bendo, G. J.; Corbel, S.; Evans, R.; Fenech, D. M.; Green, D. A.; Klöckner, H.-R.; Körding, E.; Kharb, P.; Maccarone, T. J.; Martí-Vidal, I.; Mundell, C. G.; Panessa, F.; Peck, A. B.; Pérez-Torres, M. A.; Saikia, D. J.; Saikia, P.; Shankar, F.; Spencer, R. E.; Stevens, I. R.; Uttley, P.; Westcott, J.

    2018-05-01

    We present the first data release of high-resolution (≤0.2 arcsec) 1.5-GHz radio images of 103 nearby galaxies from the Palomar sample, observed with the eMERLIN array, as part of the LeMMINGs survey. This sample includes galaxies which are active (low-ionization nuclear emission-line regions [LINER] and Seyfert) and quiescent (H II galaxies and absorption line galaxies, ALGs), which are reclassified based upon revised emission-line diagrams. We detect radio emission ≳0.2 mJy for 47/103 galaxies (22/34 for LINERS, 4/4 for Seyferts, 16/51 for H II galaxies, and 5/14 for ALGs) with radio sizes typically of ≲100 pc. We identify the radio core position within the radio structures for 41 sources. Half of the sample shows jetted morphologies. The remaining half shows single radio cores or complex morphologies. LINERs show radio structures more core-brightened than Seyferts. Radio luminosities of the sample range from 1032 to 1040 erg s-1: LINERs and H II galaxies show the highest and lowest radio powers, respectively, while ALGs and Seyferts have intermediate luminosities. We find that radio core luminosities correlate with black hole (BH) mass down to ˜107 M⊙, but a break emerges at lower masses. Using [O III] line luminosity as a proxy for the accretion luminosity, active nuclei and jetted H II galaxies follow an optical Fundamental Plane of BH activity, suggesting a common disc-jet relationship. In conclusion, LINER nuclei are the scaled-down version of FR I radio galaxies; Seyferts show less collimated jets; H II galaxies may host weak active BHs and/or nuclear star-forming cores; and recurrent BH activity may account for ALG properties.

  7. The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters - XIV. Multiple stellar populations within M 15 and their radial distribution.

    Science.gov (United States)

    Nardiello, D.; Milone, A. P.; Piotto, G.; Anderson, J.; Bedin, L. R.; Bellini, A.; Cassisi, S.; Libralato, M.; Marino, A. F.

    2018-03-01

    In the context of the Hubble Space Telescope UV Survey of Galactic Globular Clusters (GCs), we derived high-precision, multi-band photometry to investigate the multiple stellar populations in the massive and metal-poor GC M 15. By creating for red-giant branch (RGB) stars of the cluster a `chromosome map', which is a pseudo two-colour diagram made with appropriate combination of F275W, F336W, F438W, and F814W magnitudes, we revealed colour spreads around two of the three already known stellar populations. These spreads cannot be produced by photometric errors alone and could hide the existence of (two) additional populations. This discovery increases the complexity of the multiple-population phenomenon in M 15. Our analysis shows that M 15 exhibits a faint sub-giant branch (SGB), which is also detected in colour-magnitude diagrams (CMDs) made with optical magnitudes only. This poorly-populated SGB includes about 5% of the total number of SGB stars and evolves into a red RGB in the mF336W vs. mF336W - mF814W CMD, suggesting that M 15 belongs to the class of Type II GCs. We measured the relative number of stars in each population at various radial distances from the cluster centre, showing that all of these populations share the same radial distribution within statistic uncertainties. These new findings are discussed in the context of the formation and evolution scenarios of the multiple populations.

  8. An HST/COS legacy survey of high-velocity ultraviolet absorption in the Milky Way's circumgalactic medium and the Local Group

    Science.gov (United States)

    Richter, P.; Nuza, S. E.; Fox, A. J.; Wakker, B. P.; Lehner, N.; Ben Bekhti, N.; Fechner, C.; Wendt, M.; Howk, J. C.; Muzahid, S.; Ganguly, R.; Charlton, J. C.

    2017-11-01

    Context. The Milky Way is surrounded by large amounts of diffuse gaseous matter that connects the stellar body of our Galaxy with its large-scale Local Group (LG) environment. Aims: To characterize the absorption properties of this circumgalactic medium (CGM) and its relation to the LG we present the so-far largest survey of metal absorption in Galactic high-velocity clouds (HVCs) using archival ultraviolet (UV) spectra of extragalactic background sources. The UV data are obtained with the Cosmic Origins Spectrograph (COS) onboard the Hubble Space Telescope (HST) and are supplemented by 21 cm radio observations of neutral hydrogen. Methods: Along 270 sightlines we measure metal absorption in the lines of Si II, Si III, C II, and C iv and associated H I 21 cm emission in HVCs in the velocity range | vLSR | = 100-500 km s-1. With this unprecedented large HVC sample we were able to improve the statistics on HVC covering fractions, ionization conditions, small-scale structure, CGM mass, and inflow rate. For the first time, we determine robustly the angular two point correlation function of the high-velocity absorbers, systematically analyze antipodal sightlines on the celestial sphere, and compare the HVC absorption characteristics with that of damped Lyman α absorbers (DLAs) and constrained cosmological simulations of the LG (CLUES project). Results: The overall sky-covering fraction of high-velocity absorption is 77 ± 6 percent for the most sensitive ion in our survey, Si III, and for column densities log N(Si III)≥ 12.1. This value is 4-5 times higher than the covering fraction of 21 cm neutral hydrogen emission at log N(H I)≥ 18.7 along the same lines of sight, demonstrating that the Milky Way's CGM is multi-phase and predominantly ionized. The measured equivalent-width ratios of Si II, Si III, C II, and C iv are inhomogeneously distributed on large and small angular scales, suggesting a complex spatial distribution of multi-phase gas that surrounds the

  9. The dark universe dark matter and dark energy

    CERN Multimedia

    CERN. Geneva

    2008-01-01

    According to the standard cosmological model, 95% of the present mass density of the universe is dark: roughly 70% of the total in the form of dark energy and 25% in the form of dark matter. In a series of four lectures, I will begin by presenting a brief review of cosmology, and then I will review the observational evidence for dark matter and dark energy. I will discuss some of the proposals for dark matter and dark energy, and connect them to high-energy physics. I will also present an overview of an observational program to quantify the properties of dark energy.

  10. Dark Energy Survey Year 1 Results: Measurement of the Baryon Acoustic Oscillation scale in the distribution of galaxies to redshift 1

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-12-17

    We present angular diameter distance measurements obtained by locating the BAO scale in the distribution of galaxies selected from the first year of Dark Energy Survey data. We consider a sample of over 1.3 million galaxies distributed over a footprint of 1318 deg$^2$ with $0.6 < z_{\\rm photo} < 1$ and a typical redshift uncertainty of $0.03(1+z)$. This sample was selected, as fully described in a companion paper, using a color/magnitude selection that optimizes trade-offs between number density and redshift uncertainty. We investigate the BAO signal in the projected clustering using three conventions, the angular separation, the co-moving transverse separation, and spherical harmonics. Further, we compare results obtained from template based and machine learning photometric redshift determinations. We use 1800 simulations that approximate our sample in order to produce covariance matrices and allow us to validate our distance scale measurement methodology. We measure the angular diameter distance, $D_A$, at the effective redshift of our sample divided by the true physical scale of the BAO feature, $r_{\\rm d}$. We obtain close to a 4 per cent distance measurement of $D_A(z_{\\rm eff}=0.81)/r_{\\rm d} = 10.75\\pm 0.43 $. These results are consistent with the flat $\\Lambda$CDM concordance cosmological model supported by numerous other recent experimental results.

  11. Dark Spots

    Science.gov (United States)

    2006-01-01

    Dark spots (left) and 'fans' appear to scribble dusty hieroglyphics on top of the Martian south polar cap in two high-resolution Mars Global Surveyor, Mars Orbiter Camera images taken in southern spring. Each image is about 3-kilometers wide (2-miles).

  12. Dark Matter

    Indian Academy of Sciences (India)

    In Part 11 of this article we learnt that there are compelling evidences from dynamics of spiral galaxies, like our own, that there must be non-luminous matter in them. In this second part we will see that even clusters of galaxies must harbour dark matter. As if this was not enough, it turns out that if our knowledge of the ...

  13. Dark Matter

    Indian Academy of Sciences (India)

    The study of gas clouds orbiting in the outer regions of spiral galaxies has revealed that their gravitational at- traction is much larger than the stars alone can provide. Over the last twenty years, astronomers have been forced to postulate the presence of large quantities of 'dark matter' to explain their observations. They are ...

  14. Dark Matter

    Indian Academy of Sciences (India)

    interests include cinema, stamps and sketching. GENERAL I ARTICLE. Dark Matter. 1. What You See Ain'/ What You Got. Bikram Phookun and Biman Nath. The study of gas clouds orbiting in the outer regions of spiral galaxies has revealed that their gravitational at- traction is much larger than the stars alone can provide.

  15. DES J0454-4448: discovery of the first luminous z ≥ 6 quasar from the Dark Energy Survey

    Energy Technology Data Exchange (ETDEWEB)

    Reed, S. L.; McMahon, R. G.; Banerji, M.; Becker, G. D.; Gonzalez-Solares, E.; Martini, P.; Ostrovski, F.; Rauch, M.; Abbott, T.; Abdalla, F. B.; Allam, S.; Benoit-Levy, A.; Bertin, E.; Buckley-Geer, E.; Burke, D.; Carnero Rosell, A.; da Costa, L. N.; D' Andrea, C.; DePoy, D. L.; Desai, S.; Diehl, H. T.; Doel, P.; Cunha, C. E.; Estrada, J.; Evrard, A. E.; Fausti Neto, A.; Finley, D. A.; Fosalba, P.; Frieman, J.; Gruen, D.; Honscheid, K.; James, D.; Kent, S.; Kuehn, K.; Kuropatkin, N.; Lahav, O.; Maia, M. A. G.; Makler, M.; Marshall, J.; Merritt, K.; Miquel, R.; Mohr, J.; Nord, B.; Ogando, R.; Plazas, A.; Romer, K.; Roodman, A.; Rykoff, E.; Sako, M.; Sanchez, E.; Santiago, B.; Schubnell, M.; Sevilla, I.; Smith, C.; Soares-Santos, M.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; Tucker, D.; Walker, A.; Wechsler, R. H.

    2015-10-28

    We present the first results of a survey for high-redshift, z ≥ 6, quasars using izY multicolour photometric observations from the Dark Energy Survey (DES). Here we report the discovery and spectroscopic confirmation of the zAB, YAB = 20.2, 20.2 (M1450 = -26.5) quasar DES J0454-4448 with a redshift of z = 6.09±0.02 based on the onset of the Ly α forest and an H I near zone size of 4.1+1.1-1.2 proper Mpc. The quasar was selected as an i-band drop out with i-z = 2.46 and zAB < 21.5 from an area of ~300 deg2. It is the brightest of our 43 candidates and was identified for spectroscopic follow-up solely based on the DES i-z and z-Y colours. The quasar is detected by WISE and has W1AB = 19.68. The discovery of one spectroscopically confirmed quasar with 5.7 < z < 6.5 and zAB ≤ 20.2 is consistent with recent determinations of the luminosity function at z ~ 6. DES when completed will have imaged ~5000 deg2 to YAB = 23.0 (5σ point source) and we expect to discover 50–100 new quasars with z > 6 including 3–10 with z > 7 dramatically increasing the numbers of quasars currently known that are suitable for detailed studies.

  16. NASA's Dark Matter and Dark Energy Programs

    Energy Technology Data Exchange (ETDEWEB)

    Gehrels, N.; Cannizzo, J.K.

    2013-10-15

    We present an overview of selected high value scientific results and prospects for future advances from NASA's “Dark” missions, i.e., those covering dark matter (DM) and dark energy (DE). This includes current missions HST, Chandra, Swift, GALEX, Suzaku, Fermi, and future missions JWST and WFIRST. These missions and earlier ones, such as WMAP, have brought about a revolution in our understanding of the fundamental properties of the universe – its age, rate of expansion, deceleration history, and composition (i.e., relative mix of luminous matter, dark matter, and dark energy). The next chapters in this story will be written by JWST and WFIRST. JWST was the highest priority of the 2000 Decadal Survey. It will observe in the near and medium infrared, and revolutionize our understanding of the high redshift universe. WFIRST is the highest ranked large space mission of the 2010 Decadal Survey. It is a NASA observatory designed to perform wide-field imaging and slitless spectroscopic surveys of the NIR sky (0.7 – 2.5μ). WFIRST will: (i) measure the expansion history of the universe, and thereby constrain dark energy, (ii) find Earth-like planets around other stars using microlensing, and (iii) perform surveys that are ∼100 times more sensitive than current NIR surveys.

  17. LEGACY - EOP Marine Debris

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data contains towed diver surveys of and weights of marine debris removed from the near shore environments of the NWHI.

  18. Nitrate retention capacity of milldam-impacted legacy sediments and relict A horizon soils

    Science.gov (United States)

    Weitzman, Julie N.; Kaye, Jason P.

    2017-05-01

    While eutrophication is often attributed to contemporary nutrient pollution, there is growing evidence that past practices, like the accumulation of legacy sediment behind historic milldams, are also important. Given their prevalence, there is a critical need to understand how N flows through, and is retained in, legacy sediments to improve predictions and management of N transport from uplands to streams in the context of climatic variability and land-use change. Our goal was to determine how nitrate (NO3-) is cycled through the soil of a legacy-sediment-strewn stream before and after soil drying. We extracted 10.16 cm radius intact soil columns that extended 30 cm into each of the three significant soil horizons at Big Spring Run (BSR) in Lancaster, Pennsylvania: surface legacy sediment characterized by a newly developing mineral A horizon soil, mid-layer legacy sediment consisting of mineral B horizon soil and a dark, organic-rich, buried relict A horizon soil. Columns were first preincubated at field capacity and then isotopically labeled nitrate (15NO3-) was added and allowed to drain to estimate retention. The columns were then air-dried and subsequently rewet with N-free water and allowed to drain to quantify the drought-induced loss of 15NO3- from the different horizons. We found the highest initial 15N retention in the mid-layer legacy sediment (17 ± 4 %) and buried relict A soil (14 ± 3 %) horizons, with significantly lower retention in the surface legacy sediment (6 ± 1 %) horizon. As expected, rewetting dry soil resulted in 15N losses in all horizons, with the greatest losses in the buried relict A horizon soil, followed by the mid-layer legacy sediment and surface legacy sediment horizons. The 15N remaining in the soil following the post-drought leaching was highest in the mid-layer legacy sediment, intermediate in the surface legacy sediment, and lowest in the buried relict A horizon soil. Fluctuations in the water table at BSR which affect

  19. The FMOS-COSMOS Survey of Star-forming Galaxies at Z ˜ 1.6. V: Properties of Dark Matter Halos Containing Hα Emitting Galaxies

    Science.gov (United States)

    Kashino, Daichi; More, Surhud; Silverman, John D.; Daddi, Emanuele; Renzini, Alvio; Sanders, David B.; Rodighiero, Giulia; Puglisi, Annagrazia; Kajisawa, Masaru; Valentino, Francesco; Kartaltepe, Jeyhan S.; Le Fèvre, Olivier; Nagao, Tohru; Arimoto, Nobuo; Sugiyama, Naoshi

    2017-07-01

    We study the properties of dark matter halos that contain star-forming galaxies at 1.43 ≤ z ≤ 1.74, using the FMOS-COSMOS survey. The sample consists of 516 objects with a detection of the Hα emission line, which represent the star forming population at this epoch, having a stellar mass range of 109.57 ≤ M */M ⊙ ≲ 1011.4 and a star-formation rate range of 15 ≲ SFR/(M ⊙ yr-1) ≲ 600. We measure the projected two-point correlation function while carefully taking into account observational biases, and find a significant clustering amplitude at scales of 0.04-10 h -1 cMpc, with a correlation length {r}0={5.26}-0.62+0.75 {h}-1 {cMpc} and a bias b={2.44}-0.32+0.38. We interpret our clustering measurement using a halo occupation distribution model. The sample galaxies appear to reside in halos with mass {M}{{h}}={4.71}-1.62+1.19× {10}12 {h}-1 {M}⊙ on average, which will likely become present-day halos of mass M h (z = 0) ˜ 2 × 1013 h -1 M ⊙, equivalent to the typical halo mass scale of galaxy groups. We then confirm the decline of the stellar-to-halo mass ratio at M h Focus Spectrograph, a next-generation instrument that will provide strong constraints on the galaxy-formation scenario by obtaining precise measurements of galaxy clustering at z > 1.

  20. The Legacy of Nikola Tesla

    Indian Academy of Sciences (India)

    Srimath

    and problems of rural power situation in India. Writing books of science for children is his major preoccupation now. The Legacy of Nikola Tesla. 2. AC Power System and its Growth in India. D P Sen Gupta. Electrical power supply has grown enormously during this century. In 1950 the total capacity of generators producing.

  1. Exploring legacy systems using types

    NARCIS (Netherlands)

    A. van Deursen (Arie); L.M.F. Moonen (Leon)

    2000-01-01

    textabstractWe show how hypertext-based program understanding tools can achieve new levels of abstraction by using inferred type information for cases where the subject software system is written in a weakly typed language. We propose TypeExplorer, a tool for browsing COBOL legacy systems based on

  2. The Olympic legacy: feeding London

    NARCIS (Netherlands)

    Janssens, F.

    2012-01-01

    Over the last decades, the Olympic Games have increasingly claimed to deliver a social and economic ‘legacy’ to the host city. The 2012 Olympic Games in London have set out to deliver a legacy of better food for east London, an area perceived as ‘deprived’, with higher than average rates of obesity

  3. Einstein's Legacy, at the Globe

    CERN Multimedia

    2005-01-01

    One-hundred years on, Albert Einstein's theories continue to fuel the daily work of physicists. From research into gravity waves to the quest for grand unification in physics, today's researchers have not finished with the legacy of the most famous and iconic physicist of the 20th Century.

  4. The Legacy of Nikola Tesla

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 4. The Legacy of Nikola Tesla - AC Power System and its Growth in India. D P Sen Gupta. General Article Volume 12 Issue 4 April 2007 pp 69-79. Fulltext. Click here to view fulltext PDF. Permanent link:

  5. Understanding Legacy Features with Featureous

    DEFF Research Database (Denmark)

    Olszak, Andrzej; Jørgensen, Bo Nørregaard

    2011-01-01

    Feature-centric comprehension of source code is essential during software evolution. However, such comprehension is oftentimes difficult to achieve due the discrepancies between structural and functional units of object-oriented programs. We present a tool for feature-centric analysis of legacy...

  6. The Legacy of Nikola Tesla

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 3. The Legacy of Nikola Tesla - The AC System that he Helped to Usher in. D P Sen Gupta. General Article Volume 12 Issue 3 March 2007 pp 54-69. Fulltext. Click here to view fulltext PDF. Permanent link:

  7. The Legacy of S Chandrasekhar

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 4. The Legacy of S. Chandrasekhar Remembering a Giant of Our Times. Kameshwar C Wali. General Article Volume 2 Issue 4 April 1997 pp 19-24. Fulltext. Click here to view fulltext PDF. Permanent link:

  8. From Event Planning to Legacy Planning

    OpenAIRE

    Elo, Lauri

    2016-01-01

    The importance of legacy and legacy planning is increasing in the event industry. Mega-events are becoming so expensive to host that the opportunity costs decreases the amount of potential future hosts. The events aim to surpass the costs by creating positive legacies, impacts that last longer than the event itself. Small-events can also have legacies and the positive affects can be even more significant than with the mega-events. Event planning must change to legacy planning in the future, b...

  9. STELLAR, GAS, AND DARK MATTER CONTENT OF BARRED GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Cervantes Sodi, Bernardo, E-mail: b.cervantes@crya.unam.mx [Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, Campus Morelia, A.P. 3-72, C.P. 58089 Michoacán, México (Mexico)

    2017-01-20

    We select a sample of galaxies from the Sloan Digital Sky Survey Data Release 7 (SDSS-DR7) where galaxies are classified, through visual inspection, as hosting strong bars, weak bars, or as unbarred galaxies, and make use of H i mass and kinematic information from the Arecibo Legacy Fast ALFA survey catalog, to study the stellar, atomic gas, and dark matter content of barred disk galaxies. We find, in agreement with previous studies, that the bar fraction increases with increasing stellar mass. A similar trend is found with total baryonic mass, although the dependence is not as strong as with stellar mass, due to the contribution of gas. The bar fraction shows a decrease with increasing gas mass fraction. This anticorrelation between the likelihood of a galaxy hosting a bar with the gas richness of the galaxy results from the inhibiting effect the gas has in the formation of bars. We also find that for massive galaxies with stellar masses larger than 10{sup 10} M {sub ⊙}, at fixed stellar mass, the bar fraction decreases with increasing global halo mass (i.e., halo mass measured up to a radius of the order of the H i disk extent).

  10. Dark Tourism

    OpenAIRE

    Bali-Hudáková, Lenka

    2008-01-01

    This thesis is focused on the variability of the demand and the development of new trends in the fields of the tourism industry. Special attention is devoted to a new arising trend of the Dark Tourism. This trend has appeared in the end of the 20th century and it has gained the attraction of media, tourists, tourism specialists and other stakeholders. First part of the thesis is concerned with the variety of the tourism industry and the ethic question of the tourism development. The other par...

  11. Dark matter and the equivalence principle

    Science.gov (United States)

    Frieman, Joshua A.; Gradwohl, Ben-Ami

    1993-01-01

    A survey is presented of the current understanding of dark matter invoked by astrophysical theory and cosmology. Einstein's equivalence principle asserts that local measurements cannot distinguish a system at rest in a gravitational field from one that is in uniform acceleration in empty space. Recent test-methods for the equivalence principle are presently discussed as bases for testing of dark matter scenarios involving the long-range forces between either baryonic or nonbaryonic dark matter and ordinary matter.

  12. Cosmic Visions Dark Energy. Science

    Energy Technology Data Exchange (ETDEWEB)

    Dodelson, Scott [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Heitmann, Katrin [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Hirata, Chris [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Honscheid, Klaus [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Roodman, Aaron [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Seljak, Uroš [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Slosar, Anže [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Trodden, Mark [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2016-04-26

    Cosmic surveys provide crucial information about high energy physics including strong evidence for dark energy, dark matter, and inflation. Ongoing and upcoming surveys will start to identify the underlying physics of these new phenomena, including tight constraints on the equation of state of dark energy, the viability of modified gravity, the existence of extra light species, the masses of the neutrinos, and the potential of the field that drove inflation. Even after the Stage IV experiments, DESI and LSST, complete their surveys, there will still be much information left in the sky. This additional information will enable us to understand the physics underlying the dark universe at an even deeper level and, in case Stage IV surveys find hints for physics beyond the current Standard Model of Cosmology, to revolutionize our current view of the universe. There are many ideas for how best to supplement and aid DESI and LSST in order to access some of this remaining information and how surveys beyond Stage IV can fully exploit this regime. These ideas flow to potential projects that could start construction in the 2020's.

  13. Cosmic Visions Dark Energy: Science

    Energy Technology Data Exchange (ETDEWEB)

    Dodelson, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Slosar, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Heitmann, K. [Brookhaven National Lab. (BNL), Upton, NY (United States); Hirata, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Honscheid, K. [Brookhaven National Lab. (BNL), Upton, NY (United States); Roodman, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Seljak, U. [Brookhaven National Lab. (BNL), Upton, NY (United States); Trodden, M. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-04-26

    Cosmic surveys provide crucial information about high energy physics including strong evidence for dark energy, dark matter, and inflation. Ongoing and upcoming surveys will start to identify the underlying physics of these new phenomena, including tight constraints on the equation of state of dark energy, the viability of modified gravity, the existence of extra light species, the masses of the neutrinos, and the potential of the field that drove inflation. Even after the Stage IV experiments, DESI and LSST, complete their surveys, there will still be much information left in the sky. This additional information will enable us to understand the physics underlying the dark universe at an even deeper level and, in case Stage IV surveys find hints for physics beyond the current Standard Model of Cosmology, to revolutionize our current view of the universe. There are many ideas for how best to supplement and aid DESI and LSST in order to access some of this remaining information and how surveys beyond Stage IV can fully exploit this regime. These ideas flow to potential projects that could start construction in the 2020's.

  14. Legacies of the Manhattan Project

    Science.gov (United States)

    Kevles, Daniel

    2017-01-01

    The Manhattan Project of World War II mobilized thousands of people, including many of the nation's leading physicists, and extensive material resources to design, develop, and manufacture the world's first nuclear weapons. It also established sprawling new facilities for the production of fissionable fuels - notably at Oak Ridge, Tennessee, and Hanford, Washington. It left a set of powerful legacies in the context of the Cold War - endowing scientists with conscience-taxing responsibilities in the nuclear arms race; promoting enormous patronage of academic research by defense and defense-related federal agencies, notably the Office of Naval Research and the Atomic Energy Commission; and turning its wartime facilities into major national laboratories that advanced the fields of high-energy and nuclear physics and stimulated local industrial economies but that in some cases, notably at Hanford, severely polluted the surrounding environment with radioactive waste and disrupted the livelihoods of native peoples. ``Legacies of the Manhattan Project''

  15. Decaying dark matter from dark instantons

    International Nuclear Information System (INIS)

    Carone, Christopher D.; Erlich, Joshua; Primulando, Reinard

    2010-01-01

    We construct an explicit, TeV-scale model of decaying dark matter in which the approximate stability of the dark matter candidate is a consequence of a global symmetry that is broken only by instanton-induced operators generated by a non-Abelian dark gauge group. The dominant dark matter decay channels are to standard model leptons. Annihilation of the dark matter to standard model states occurs primarily through the Higgs portal. We show that the mass and lifetime of the dark matter candidate in this model can be chosen to be consistent with the values favored by fits to data from the PAMELA and Fermi-LAT experiments.

  16. Can dark matter decay in dark energy?

    International Nuclear Information System (INIS)

    Pereira, S. H.; Jesus, J. F.

    2009-01-01

    We analyze the interaction between dark energy and dark matter from a thermodynamical perspective. By assuming they have different temperatures, we study the possibility of occurring a decay from dark matter into dark energy, characterized by a negative parameter Q. We find that, if at least one of the fluids has nonvanishing chemical potential, for instance μ x dm =0 or μ x =0 and μ dm >0, the decay is possible, where μ x and μ dm are the chemical potentials of dark energy and dark matter, respectively. Using recent cosmological data, we find that, for a fairly simple interaction, the dark matter decay is favored with a probability of ∼93% over the dark energy decay. This result comes from a likelihood analysis where only background evolution has been considered.

  17. Unification of dark energy and dark matter

    International Nuclear Information System (INIS)

    Takahashi, Fuminobu; Yanagida, T.T.

    2006-01-01

    We propose a scenario in which dark energy and dark matter are described in a unified manner. The ultralight pseudo-Nambu-Goldstone (pNG) boson, A, naturally explains the observed magnitude of dark energy, while the bosonic supersymmetry partner of the pNG boson, B, can be a dominant component of dark matter. The decay of B into a pair of electron and positron may explain the 511 keV γ ray from the Galactic Center

  18. Repurposing legacy data innovative case studies

    CERN Document Server

    Berman, Jules J

    2015-01-01

    Repurposing Legacy Data: Innovative Case Studies takes a look at how data scientists have re-purposed legacy data, whether their own, or legacy data that has been donated to the public domain. Most of the data stored worldwide is legacy data-data created some time in the past, for a particular purpose, and left in obsolete formats. As with keepsakes in an attic, we retain this information thinking it may have value in the future, though we have no current use for it. The case studies in this book, from such diverse fields as cosmology, quantum physics, high-energy physics, microbiology,

  19. Dark matter that can form dark stars

    International Nuclear Information System (INIS)

    Gondolo, Paolo; Huh, Ji-Haeng; Kim, Hyung Do; Scopel, Stefano

    2010-01-01

    The first stars to form in the Universe may be powered by the annihilation of weakly interacting dark matter particles. These so-called dark stars, if observed, may give us a clue about the nature of dark matter. Here we examine which models for particle dark matter satisfy the conditions for the formation of dark stars. We find that in general models with thermal dark matter lead to the formation of dark stars, with few notable exceptions: heavy neutralinos in the presence of coannihilations, annihilations that are resonant at dark matter freeze-out but not in dark stars, some models of neutrinophilic dark matter annihilating into neutrinos only and lighter than about 50 GeV. In particular, we find that a thermal DM candidate in standard Cosmology always forms a dark star as long as its mass is heavier than ≅ 50 GeV and the thermal average of its annihilation cross section is the same at the decoupling temperature and during the dark star formation, as for instance in the case of an annihilation cross section with a non-vanishing s-wave contribution

  20. The Dark Energy Camera

    Science.gov (United States)

    Flaugher, B.; Diehl, H. T.; Honscheid, K.; Abbott, T. M. C.; Alvarez, O.; Angstadt, R.; Annis, J. T.; Antonik, M.; Ballester, O.; Beaufore, L.; Bernstein, G. M.; Bernstein, R. A.; Bigelow, B.; Bonati, M.; Boprie, D.; Brooks, D.; Buckley-Geer, E. J.; Campa, J.; Cardiel-Sas, L.; Castander, F. J.; Castilla, J.; Cease, H.; Cela-Ruiz, J. M.; Chappa, S.; Chi, E.; Cooper, C.; da Costa, L. N.; Dede, E.; Derylo, G.; DePoy, D. L.; de Vicente, J.; Doel, P.; Drlica-Wagner, A.; Eiting, J.; Elliott, A. E.; Emes, J.; Estrada, J.; Fausti Neto, A.; Finley, D. A.; Flores, R.; Frieman, J.; Gerdes, D.; Gladders, M. D.; Gregory, B.; Gutierrez, G. R.; Hao, J.; Holland, S. E.; Holm, S.; Huffman, D.; Jackson, C.; James, D. J.; Jonas, M.; Karcher, A.; Karliner, I.; Kent, S.; Kessler, R.; Kozlovsky, M.; Kron, R. G.; Kubik, D.; Kuehn, K.; Kuhlmann, S.; Kuk, K.; Lahav, O.; Lathrop, A.; Lee, J.; Levi, M. E.; Lewis, P.; Li, T. S.; Mandrichenko, I.; Marshall, J. L.; Martinez, G.; Merritt, K. W.; Miquel, R.; Muñoz, F.; Neilsen, E. H.; Nichol, R. C.; Nord, B.; Ogando, R.; Olsen, J.; Palaio, N.; Patton, K.; Peoples, J.; Plazas, A. A.; Rauch, J.; Reil, K.; Rheault, J.-P.; Roe, N. A.; Rogers, H.; Roodman, A.; Sanchez, E.; Scarpine, V.; Schindler, R. H.; Schmidt, R.; Schmitt, R.; Schubnell, M.; Schultz, K.; Schurter, P.; Scott, L.; Serrano, S.; Shaw, T. M.; Smith, R. C.; Soares-Santos, M.; Stefanik, A.; Stuermer, W.; Suchyta, E.; Sypniewski, A.; Tarle, G.; Thaler, J.; Tighe, R.; Tran, C.; Tucker, D.; Walker, A. R.; Wang, G.; Watson, M.; Weaverdyck, C.; Wester, W.; Woods, R.; Yanny, B.; DES Collaboration

    2015-11-01

    The Dark Energy Camera is a new imager with a 2.°2 diameter field of view mounted at the prime focus of the Victor M. Blanco 4 m telescope on Cerro Tololo near La Serena, Chile. The camera was designed and constructed by the Dark Energy Survey Collaboration and meets or exceeds the stringent requirements designed for the wide-field and supernova surveys for which the collaboration uses it. The camera consists of a five-element optical corrector, seven filters, a shutter with a 60 cm aperture, and a charge-coupled device (CCD) focal plane of 250 μm thick fully depleted CCDs cooled inside a vacuum Dewar. The 570 megapixel focal plane comprises 62 2k × 4k CCDs for imaging and 12 2k × 2k CCDs for guiding and focus. The CCDs have 15 μm × 15 μm pixels with a plate scale of 0.″263 pixel-1. A hexapod system provides state-of-the-art focus and alignment capability. The camera is read out in 20 s with 6-9 electron readout noise. This paper provides a technical description of the camera's engineering, construction, installation, and current status.

  1. THE DARK ENERGY CAMERA

    Energy Technology Data Exchange (ETDEWEB)

    Flaugher, B.; Diehl, H. T.; Alvarez, O.; Angstadt, R.; Annis, J. T.; Buckley-Geer, E. J. [Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States); Honscheid, K. [Center for Cosmology and Astro-Particle Physics, The Ohio State University, Columbus, OH 43210 (United States); Abbott, T. M. C.; Bonati, M. [Cerro Tololo Inter-American Observatory, National Optical Astronomy Observatory, Casilla 603, La Serena (Chile); Antonik, M.; Brooks, D. [Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT (United Kingdom); Ballester, O.; Cardiel-Sas, L. [Institut de Física d’Altes Energies, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Barcelona (Spain); Beaufore, L. [Department of Physics, The Ohio State University, Columbus, OH 43210 (United States); Bernstein, G. M. [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104 (United States); Bernstein, R. A. [Carnegie Observatories, 813 Santa Barbara St., Pasadena, CA 91101 (United States); Bigelow, B.; Boprie, D. [Department of Physics, University of Michigan, Ann Arbor, MI 48109 (United States); Campa, J. [Centro de Investigaciones Energèticas, Medioambientales y Tecnológicas (CIEMAT), Madrid (Spain); Castander, F. J., E-mail: diehl@fnal.gov [Institut de Ciències de l’Espai, IEEC-CSIC, Campus UAB, Facultat de Ciències, Torre C5 par-2, E-08193 Bellaterra, Barcelona (Spain); Collaboration: DES Collaboration; and others

    2015-11-15

    The Dark Energy Camera is a new imager with a 2.°2 diameter field of view mounted at the prime focus of the Victor M. Blanco 4 m telescope on Cerro Tololo near La Serena, Chile. The camera was designed and constructed by the Dark Energy Survey Collaboration and meets or exceeds the stringent requirements designed for the wide-field and supernova surveys for which the collaboration uses it. The camera consists of a five-element optical corrector, seven filters, a shutter with a 60 cm aperture, and a charge-coupled device (CCD) focal plane of 250 μm thick fully depleted CCDs cooled inside a vacuum Dewar. The 570 megapixel focal plane comprises 62 2k × 4k CCDs for imaging and 12 2k × 2k CCDs for guiding and focus. The CCDs have 15 μm × 15 μm pixels with a plate scale of 0.″263 pixel{sup −1}. A hexapod system provides state-of-the-art focus and alignment capability. The camera is read out in 20 s with 6–9 electron readout noise. This paper provides a technical description of the camera's engineering, construction, installation, and current status.

  2. Galactic signatures of decaying dark matter

    International Nuclear Information System (INIS)

    Zhang, Le; Sigl, Guenter

    2009-05-01

    If dark matter decays into electrons and positrons, it can affect Galactic radio emissions and the local cosmic ray fluxes. We propose a new, more general analysis of constraints on dark matter. The constraints can be obtained for any decaying dark matter model by convolving the specific dark matter decay spectrum with a response function. We derive this response function from full-sky radio surveys at 408 MHz, 1.42 GHz and 23 GHz, as well as from the positron flux recently reported by PAMELA. We discuss the influence of astrophysical uncertainties on the response function, such as from propagation and from the profiles of the dark matter and the Galactic magnetic field. As an application, we find that some widely used dark matter decay scenarios can be ruled out under modest assumptions. (orig.)

  3. Galactic signatures of decaying dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Le; Sigl, Guenter [Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik; Redondo, Javier [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2009-05-15

    If dark matter decays into electrons and positrons, it can affect Galactic radio emissions and the local cosmic ray fluxes. We propose a new, more general analysis of constraints on dark matter. The constraints can be obtained for any decaying dark matter model by convolving the specific dark matter decay spectrum with a response function. We derive this response function from full-sky radio surveys at 408 MHz, 1.42 GHz and 23 GHz, as well as from the positron flux recently reported by PAMELA. We discuss the influence of astrophysical uncertainties on the response function, such as from propagation and from the profiles of the dark matter and the Galactic magnetic field. As an application, we find that some widely used dark matter decay scenarios can be ruled out under modest assumptions. (orig.)

  4. WSRT HI imaging of ultra-compact high velocity clouds: gas-bearing dark matter minihalos?

    Science.gov (United States)

    Adams, Elizabeth A.; Oosterloo, Tom; Giovanelli, Riccardo; Haynes, Martha P.; Cannon, John M.; Faerman, Yakov; Janesh, William; Janowiecki, Steven; Munoz, Ricardo; Rhode, Katherine L.; Salzer, John Joseph; Sternberg, Amiel

    2015-01-01

    A long standing problem in cosmology is the mismatch between the number of low mass dark matter halos predicted by simulations and the number of low mass galaxies observed in the Local Volume. We recently presented a set of isolated ultra-compact high velocity clouds (UCHVCs) identified within the dataset of the Arecibo Legacy Fast ALFA (ALFALFA) HI line survey that are consistent with representing low-mass gas-bearing dark matter halos within the Local Volume (Adams+ 2013). At distances of ~1 Mpc, the UCHVCs have HI masses of ~10^5 Msun and indicative dynamical masses of 10^7-10^8 Msun. The HI diameters of the UCHVCs range from 4' to 20', or 1 to 6 kpc at a distance of 1 Mpc.We have selected the most compact and isolated UCHVCs with the highest average column densities as representing the best galaxy candidates. These systems have been observed with the Westerbork Synthesis Radio Telescope (WSRT) to enable higher spatial resolution (~60") studies of the HI distribution. The HI morphology revealed by the WSRT data offers clues to the environment and origin of the UCHVCs, the kinematics of the HI allow the underlying mass distribution to be constrained, and the combination of spatial and spectral resolution allow the detection of a cold neutral medium component to the HI. The WSRT HI observations discriminate among the selected galaxy candidates for those objects that are most likely gas-bearing dark matter halos.One UCHVC, AGC198606, is of particular interest as it is located 16 km/s and 1.2 degrees from Leo T and has similar HI properties within the ALFALFA dataset. The WSRT HI observations reveal a smooth HI morphology and a velocity gradient along the HI major axis of the system consistent with rotation. These properties are consistent with the hypothesis that this object is a gas-bearing low-mass dark matter halo.

  5. Radiative Transfer Analysis of Neptune’s New Dark Vortex

    Science.gov (United States)

    Tollefson, Joshua; Luszcz-Cook, Statia H.; Wong, Michael H.; de Pater, Imke

    2017-10-01

    A new dark spot on Neptune was discovered in late 2015, named: "SDS-2015" for "Southern Dark Spot discovered in 2015". Subsequent observations from Hubble Space Telescope Mid-Cycle 23 (PI: Wong) and the Outer Planetary Atmospheres Legacy (OPAL) programs (PI: Simon-Miller) took the first multispectral data over multiple viewing geometries of a Neptunian dark spot, spanning wavelengths from 336 to 763nm. SDS-2015 is visible at blue wavelengths, with contrast from the background atmosphere peaking at 467nm. In this abstract, we present a radiative transfer analysis of the dark spot and surrounding background atmosphere. We summarize our retrieved properties of Neptune's background atmosphere, including its aerosol structure and methane profile, and compare our findings in the optical wavelengths to those in the near-infrared. We then discuss various hypotheses about the make up of SDS-2015 and its interaction with the background atmosphere.

  6. Weak lensing and dark energy

    International Nuclear Information System (INIS)

    Huterer, Dragan

    2002-01-01

    We study the power of upcoming weak lensing surveys to probe dark energy. Dark energy modifies the distance-redshift relation as well as the matter power spectrum, both of which affect the weak lensing convergence power spectrum. Some dark-energy models predict additional clustering on very large scales, but this probably cannot be detected by weak lensing alone due to cosmic variance. With reasonable prior information on other cosmological parameters, we find that a survey covering 1000 sq deg down to a limiting magnitude of R=27 can impose constraints comparable to those expected from upcoming type Ia supernova and number-count surveys. This result, however, is contingent on the control of both observational and theoretical systematics. Concentrating on the latter, we find that the nonlinear power spectrum of matter perturbations and the redshift distribution of source galaxies both need to be determined accurately in order for weak lensing to achieve its full potential. Finally, we discuss the sensitivity of the three-point statistics to dark energy

  7. An Approach to Peabody's Gifts and Legacies.

    Science.gov (United States)

    Parker, Franklin

    1994-01-01

    One in a collection of papers on self-made millionaire and educational philanthropist George Peabody offers a listing of his gifts and legacies, which fall into the categories of libraries, lyceums, athenaeum, art, music; science; model housing; education; exploration; patriotic causes; historical societies; hospitals; churches; legacies; and…

  8. Types and concept analysis for legacy systems

    NARCIS (Netherlands)

    T. Kuipers (Tobias); L.M.F. Moonen (Leon)

    2000-01-01

    textabstractWe combine type inference and concept analysis in order to gain insight into legacy software systems. Type inference for Cobol yields the types for variables and program parameters. These types are used to perform mathematical concept analysis on legacy systems. We have developed

  9. Northeastern Area Forest Legacy Program Yearbook 2008

    Science.gov (United States)

    US Forest Service, Northeastern Area, State and Private Forestry

    2009-01-01

    The purpose of the Forest Legacy Program (FLP) is to protect environmentally important forest areas that are threatened by conversion to nonforest uses. The Forest Legacy Program is a partnership between participating States and the Forest Service, U.S. Department of Agriculture. These two entities work together to identify important forest lands and...

  10. A validatable legacy database migration using ORM

    NARCIS (Netherlands)

    Moes, T.H.; Wijbenga, J.P.; Balsters, H.; Huitema, G.B.

    2012-01-01

    This paper describes a method used in a real-life case of a legacy database migration. The difficulty of the case lies in the fact that the legacy application to be replaced has to remain fully available during the migration process while at the same time data from the old system is to be integrated

  11. The dark side of curvature

    International Nuclear Information System (INIS)

    Barenboim, Gabriela; Martínez, Enrique Fernández; Mena, Olga; Verde, Licia

    2010-01-01

    Geometrical tests such as the combination of the Hubble parameter H(z) and the angular diameter distance d A (z) can, in principle, break the degeneracy between the dark energy equation of state parameter w(z), and the spatial curvature Ω k in a direct, model-independent way. In practice, constraints on these quantities achievable from realistic experiments, such as those to be provided by Baryon Acoustic Oscillation (BAO) galaxy surveys in combination with CMB data, can resolve the cosmic confusion between the dark energy equation of state parameter and curvature only statistically and within a parameterized model for w(z). Combining measurements of both H(z) and d A (z) up to sufficiently high redshifts z ∼ 2 and employing a parameterization of the redshift evolution of the dark energy equation of state are the keys to resolve the w(z)−Ω k degeneracy

  12. Dark Energy Camera for Blanco

    Energy Technology Data Exchange (ETDEWEB)

    Binder, Gary A.; /Caltech /SLAC

    2010-08-25

    In order to make accurate measurements of dark energy, a system is needed to monitor the focus and alignment of the Dark Energy Camera (DECam) to be located on the Blanco 4m Telescope for the upcoming Dark Energy Survey. One new approach under development is to fit out-of-focus star images to a point spread function from which information about the focus and tilt of the camera can be obtained. As a first test of a new algorithm using this idea, simulated star images produced from a model of DECam in the optics software Zemax were fitted. Then, real images from the Mosaic II imager currently installed on the Blanco telescope were used to investigate the algorithm's capabilities. A number of problems with the algorithm were found, and more work is needed to understand its limitations and improve its capabilities so it can reliably predict camera alignment and focus.

  13. Conformal Gravity: Dark Matter and Dark Energy

    Directory of Open Access Journals (Sweden)

    Robert K. Nesbet

    2013-01-01

    Full Text Available This short review examines recent progress in understanding dark matter, dark energy, and galactic halos using theory that departs minimally from standard particle physics and cosmology. Strict conformal symmetry (local Weyl scaling covariance, postulated for all elementary massless fields, retains standard fermion and gauge boson theory but modifies Einstein–Hilbert general relativity and the Higgs scalar field model, with no new physical fields. Subgalactic phenomenology is retained. Without invoking dark matter, conformal gravity and a conformal Higgs model fit empirical data on galactic rotational velocities, galactic halos, and Hubble expansion including dark energy.

  14. Global environmental change effects on plant community composition trajectories depend upon management legacies.

    Science.gov (United States)

    Perring, Michael P; Bernhardt-Römermann, Markus; Baeten, Lander; Midolo, Gabriele; Blondeel, Haben; Depauw, Leen; Landuyt, Dries; Maes, Sybryn L; De Lombaerde, Emiel; Carón, Maria Mercedes; Vellend, Mark; Brunet, Jörg; Chudomelová, Markéta; Decocq, Guillaume; Diekmann, Martin; Dirnböck, Thomas; Dörfler, Inken; Durak, Tomasz; De Frenne, Pieter; Gilliam, Frank S; Hédl, Radim; Heinken, Thilo; Hommel, Patrick; Jaroszewicz, Bogdan; Kirby, Keith J; Kopecký, Martin; Lenoir, Jonathan; Li, Daijiang; Máliš, František; Mitchell, Fraser J G; Naaf, Tobias; Newman, Miles; Petřík, Petr; Reczyńska, Kamila; Schmidt, Wolfgang; Standovár, Tibor; Świerkosz, Krzysztof; Van Calster, Hans; Vild, Ondřej; Wagner, Eva Rosa; Wulf, Monika; Verheyen, Kris

    2018-04-01

    The contemporary state of functional traits and species richness in plant communities depends on legacy effects of past disturbances. Whether temporal responses of community properties to current environmental changes are altered by such legacies is, however, unknown. We expect global environmental changes to interact with land-use legacies given different community trajectories initiated by prior management, and subsequent responses to altered resources and conditions. We tested this expectation for species richness and functional traits using 1814 survey-resurvey plot pairs of understorey communities from 40 European temperate forest datasets, syntheses of management transitions since the year 1800, and a trait database. We also examined how plant community indicators of resources and conditions changed in response to management legacies and environmental change. Community trajectories were clearly influenced by interactions between management legacies from over 200 years ago and environmental change. Importantly, higher rates of nitrogen deposition led to increased species richness and plant height in forests managed less intensively in 1800 (i.e., high forests), and to decreases in forests with a more intensive historical management in 1800 (i.e., coppiced forests). There was evidence that these declines in community variables in formerly coppiced forests were ameliorated by increased rates of temperature change between surveys. Responses were generally apparent regardless of sites' contemporary management classifications, although sometimes the management transition itself, rather than historic or contemporary management types, better explained understorey responses. Main effects of environmental change were rare, although higher rates of precipitation change increased plant height, accompanied by increases in fertility indicator values. Analysis of indicator values suggested the importance of directly characterising resources and conditions to better

  15. A COMPLETE SPECTROSCOPIC SURVEY OF THE MILKY WAY SATELLITE SEGUE 1: DARK MATTER CONTENT, STELLAR MEMBERSHIP, AND BINARY PROPERTIES FROM A BAYESIAN ANALYSIS

    International Nuclear Information System (INIS)

    Martinez, Gregory D.; Minor, Quinn E.; Bullock, James; Kaplinghat, Manoj; Simon, Joshua D.; Geha, Marla

    2011-01-01

    We introduce a comprehensive analysis of multi-epoch stellar line-of-sight velocities to determine the intrinsic velocity dispersion of the ultrafaint satellites of the Milky Way. Our method includes a simultaneous Bayesian analysis of both membership probabilities and the contribution of binary orbital motion to the observed velocity dispersion within a 14-parameter likelihood. We apply our method to the Segue 1 dwarf galaxy and conclude that Segue 1 is a dark-matter-dominated galaxy at high probability with an intrinsic velocity dispersion of 3.7 +1.4 -1.1 km s -1 . The dark matter halo required to produce this dispersion must have an average density of ρ-bar 1/2 = 2.5 -1.9 +4.1 , M sun , pc -3 within a sphere that encloses half the galaxy's stellar luminosity. This is the highest measured density of dark matter in the Local Group. Our results show that a significant fraction of the stars in Segue 1 may be binaries with the most probable mean period close to 10 years, but also consistent with the 180 year mean period seen in the solar vicinity at about 1σ. Despite this binary population, the possibility that Segue 1 is a bound star cluster with the observed velocity dispersion arising from the orbital motion of binary stars is disfavored by the multi-epoch stellar velocity data at greater than 99% C.L. Finally, our treatment yields a projected (two-dimensional) half-light radius for the stellar profile of Segue 1 of R 1/2 = 28 +5 -4 pc, in excellent agreement with photometric measurements.

  16. Strategies for dark matter detection

    International Nuclear Information System (INIS)

    Silk, J.

    1988-01-01

    The present status of alternative forms of dark matter, both baryonic and nonbaryonic, is reviewed. Alternative arguments are presented for the predominance of either cold dark matter (CDM) or of baryonic dark matter (BDM). Strategies are described for dark matter detection, both for dark matter that consists of weakly interacting relic particles and for dark matter that consists of dark stellar remnants

  17. X-ray surveys - Weighting the dark matter haloes of X-ray AGN: towards a physical description of the accretion history of the Universe

    Science.gov (United States)

    Georgakakis, Antonis; Mountrichas, G.; Fanidakis, N.; Finoguenov, A.; Aegis Collaboration

    2012-09-01

    The masses of the dark matter haloes in which AGN live is powerful diagnostic of the conditions under which supermassive black holes form and evolve across cosmic time. A new clustering estimation method will be presented which requires spectroscopy only for the AGN and uses photometric redshift probability density functions for galaxies to determine the projected real-space AGN/galaxy cross-correlation function. Our method is superior to traditional AGN clustering estimators (e.g. auto-correlation function) because (i) random errors are significantly suppressed when counting AGN/galaxy pairs, (ii) the impact of sample variance is minimized, and (iii) the requirements for spectroscopy are minimal; only spectroscopic redshift measurements for the AGN are needed. This method is applied to the combined AEGIS, COSMOS and ECDFS fields to infer the bias and dark matter halo mass of moderate luminosity (Lx~10^43 erg/s/cm^2) X-ray AGN at z~1 (total of 400). Predictions from the GALFORM semi-analytic model will be compared to the observations to show that a combination of hot and cold-gas accretion (the latter triggered by disk instabilities in spirals rather than mergers) reproduce well the clustering properties of X-ray AGN over a range of redshifts and luminosities.

  18. The legacy of fossil fuels.

    Science.gov (United States)

    Armaroli, Nicola; Balzani, Vincenzo

    2011-03-01

    Currently, over 80% of the energy used by mankind comes from fossil fuels. Harnessing coal, oil and gas, the energy resources contained in the store of our spaceship, Earth, has prompted a dramatic expansion in energy use and a substantial improvement in the quality of life of billions of individuals in some regions of the world. Powering our civilization with fossil fuels has been very convenient, but now we know that it entails severe consequences. We treat fossil fuels as a resource that anyone anywhere can extract and use in any fashion, and Earth's atmosphere, soil and oceans as a dump for their waste products, including more than 30 Gt/y of carbon dioxide. At present, environmental legacy rather than consistence of exploitable reserves, is the most dramatic problem posed by the relentless increase of fossil fuel global demand. Harmful effects on the environment and human health, usually not incorporated into the pricing of fossil fuels, include immediate and short-term impacts related to their discovery, extraction, transportation, distribution, and burning as well as climate change that are spread over time to future generations or over space to the entire planet. In this essay, several aspects of the fossil fuel legacy are discussed, such as alteration of the carbon cycle, carbon dioxide rise and its measurement, greenhouse effect, anthropogenic climate change, air pollution and human health, geoengineering proposals, land and water degradation, economic problems, indirect effects on the society, and the urgent need of regulatory efforts and related actions to promote a gradual transition out of the fossil fuel era. While manufacturing sustainable solar fuels appears to be a longer-time perspective, alternatives energy sources already exist that have the potential to replace fossil fuels as feedstocks for electricity production. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. 3D map of Universe bolsters case for dark energy and dark matter

    CERN Multimedia

    2003-01-01

    "Astronomers from the Sloan Digital Sky Survey (SDSS) have made the most precise measurement to date of the cosmic clustering of galaxies and dark matter, refining our understanding of the structure and evolution of the Universe" (1 page).

  20. Impeded Dark Matter

    International Nuclear Information System (INIS)

    Kopp, Joachim; Liu, Jia; Slatyer, Tracy R.; Wang, Xiao-Ping; Xue, Wei

    2016-01-01

    We consider dark matter models in which the mass splitting between the dark matter particles and their annihilation products is tiny. Compared to the previously proposed Forbidden Dark Matter scenario, the mass splittings we consider are much smaller, and are allowed to be either positive or negative. To emphasize this modification, we dub our scenario “Impeded Dark Matter”. We demonstrate that Impeded Dark Matter can be easily realized without requiring tuning of model parameters. For negative mass splitting, we demonstrate that the annihilation cross-section for Impeded Dark Matter depends linearly on the dark matter velocity or may even be kinematically forbidden, making this scenario almost insensitive to constraints from the cosmic microwave background and from observations of dwarf galaxies. Accordingly, it may be possible for Impeded Dark Matter to yield observable signals in clusters or the Galactic center, with no corresponding signal in dwarfs. For positive mass splitting, we show that the annihilation cross-section is suppressed by the small mass splitting, which helps light dark matter to survive increasingly stringent constraints from indirect searches. As specific realizations for Impeded Dark Matter, we introduce a model of vector dark matter from a hidden SU(2) sector, and a composite dark matter scenario based on a QCD-like dark sector.

  1. Impeded Dark Matter

    Energy Technology Data Exchange (ETDEWEB)

    Kopp, Joachim; Liu, Jia [PRISMA Cluster of Excellence & Mainz Institute for Theoretical Physics,Johannes Gutenberg University,Staudingerweg 7, 55099 Mainz (Germany); Slatyer, Tracy R. [Center for Theoretical Physics, Massachusetts Institute of Technology,Cambridge, MA 02139 (United States); Wang, Xiao-Ping [PRISMA Cluster of Excellence & Mainz Institute for Theoretical Physics,Johannes Gutenberg University,Staudingerweg 7, 55099 Mainz (Germany); Xue, Wei [Center for Theoretical Physics, Massachusetts Institute of Technology,Cambridge, MA 02139 (United States)

    2016-12-12

    We consider dark matter models in which the mass splitting between the dark matter particles and their annihilation products is tiny. Compared to the previously proposed Forbidden Dark Matter scenario, the mass splittings we consider are much smaller, and are allowed to be either positive or negative. To emphasize this modification, we dub our scenario “Impeded Dark Matter”. We demonstrate that Impeded Dark Matter can be easily realized without requiring tuning of model parameters. For negative mass splitting, we demonstrate that the annihilation cross-section for Impeded Dark Matter depends linearly on the dark matter velocity or may even be kinematically forbidden, making this scenario almost insensitive to constraints from the cosmic microwave background and from observations of dwarf galaxies. Accordingly, it may be possible for Impeded Dark Matter to yield observable signals in clusters or the Galactic center, with no corresponding signal in dwarfs. For positive mass splitting, we show that the annihilation cross-section is suppressed by the small mass splitting, which helps light dark matter to survive increasingly stringent constraints from indirect searches. As specific realizations for Impeded Dark Matter, we introduce a model of vector dark matter from a hidden SU(2) sector, and a composite dark matter scenario based on a QCD-like dark sector.

  2. DarkSide search for dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, T.; Alton, D.; Arisaka, K.; Back, H. O.; Beltrame, P.; Benziger, J.; Bonfini, G.; Brigatti, A.; Brodsky, J.; Bussino, S.; Cadonati, L.; Calaprice, F.; Candela, A.; Cao, H.; Cavalcante, P.; Chepurnov, A.; Chidzik, S.; Cocco, A. G.; Condon, C.; D' Angelo, D.; Davini, S.; Vincenzi, M. De; Haas, E. De; Derbin, A.; Pietro, G. Di; Dratchnev, I.; Durben, D.; Empl, A.; Etenko, A.; Fan, A.; Fiorillo, G.; Franco, D.; Fomenko, K.; Forster, G.; Gabriele, F.; Galbiati, C.; Gazzana, S.; Ghiano, C.; Goretti, A.; Grandi, L.; Gromov, M.; Guan, M.; Guo, C.; Guray, G.; Hungerford, E. V.; Ianni, Al; Ianni, An; Joliet, C.; Kayunov, A.; Keeter, K.; Kendziora, C.; Kidner, S.; Klemmer, R.; Kobychev, V.; Koh, G.; Komor, M.; Korablev, D.; Korga, G.; Li, P.; Loer, B.; Lombardi, P.; Love, C.; Ludhova, L.; Luitz, S.; Lukyanchenko, L.; Lund, A.; Lung, K.; Ma, Y.; Machulin, I.; Mari, S.; Maricic, J.; Martoff, C. J.; Meregaglia, A.; Meroni, E.; Meyers, P.; Mohayai, T.; Montanari, D.; Montuschi, M.; Monzani, M. E.; Mosteiro, P.; Mount, B.; Muratova, V.; Nelson, A.; Nemtzow, A.; Nurakhov, N.; Orsini, M.; Ortica, F.; Pallavicini, M.; Pantic, E.; Parmeggiano, S.; Parsells, R.; Pelliccia, N.; Perasso, L.; Perasso, S.; Perfetto, F.; Pinsky, L.; Pocar, A.; Pordes, S.; Randle, K.; Ranucci, G.; Razeto, A.; Romani, A.; Rossi, B.; Rossi, N.; Rountree, S. D.; Saggese, P.; Saldanha, R.; Salvo, C.; Sands, W.; Seigar, M.; Semenov, D.; Shields, E.; Skorokhvatov, M.; Smirnov, O.; Sotnikov, A.; Sukhotin, S.; Suvarov, Y.; Tartaglia, R.; Tatarowicz, J.; Testera, G.; Thompson, J.; Tonazzo, A.; Unzhakov, E.; Vogelaar, R. B.; Wang, H.; Westerdale, S.; Wojcik, M.; Wright, A.; Xu, J.; Yang, C.; Zavatarelli, S.; Zehfus, M.; Zhong, W.; Zuzel, G.

    2013-11-22

    The DarkSide staged program utilizes a two-phase time projection chamber (TPC) with liquid argon as the target material for the scattering of dark matter particles. Efficient background reduction is achieved using low radioactivity underground argon as well as several experimental handles such as pulse shape, ratio of ionization over scintillation signal, 3D event reconstruction, and active neutron and muon vetos. The DarkSide-10 prototype detector has proven high scintillation light yield, which is a particularly important parameter as it sets the energy threshold for the pulse shape discrimination technique. The DarkSide-50 detector system, currently in commissioning phase at the Gran Sasso Underground Laboratory, will reach a sensitivity to dark matter spin-independent scattering cross section of 10-45 cm2 within 3 years of operation.

  3. The dark side of cosmology: dark matter and dark energy.

    Science.gov (United States)

    Spergel, David N

    2015-03-06

    A simple model with only six parameters (the age of the universe, the density of atoms, the density of matter, the amplitude of the initial fluctuations, the scale dependence of this amplitude, and the epoch of first star formation) fits all of our cosmological data . Although simple, this standard model is strange. The model implies that most of the matter in our Galaxy is in the form of "dark matter," a new type of particle not yet detected in the laboratory, and most of the energy in the universe is in the form of "dark energy," energy associated with empty space. Both dark matter and dark energy require extensions to our current understanding of particle physics or point toward a breakdown of general relativity on cosmological scales. Copyright © 2015, American Association for the Advancement of Science.

  4. Very heavy dark Skyrmions

    International Nuclear Information System (INIS)

    Dick, Rainer

    2017-01-01

    A dark sector with a solitonic component provides a means to circumvent the problem of generically low annihilation cross sections of very heavy dark matter particles. At the same time, enhanced annihilation cross sections are necessary for indirect detection of very heavy dark matter components beyond 100 TeV. Non-thermally produced dark matter in this mass range could therefore contribute to the cosmic γ-ray and neutrino flux above 100 TeV, and massive Skyrmions provide an interesting framework for the discussion of these scenarios. Therefore a Higgs portal and a neutrino portal for very heavy Skyrmion dark matter are discussed. The Higgs portal model demonstrates a dark mediator bottleneck, where limitations on particle annihilation cross sections will prevent a signal from the potentially large soliton annihilation cross sections. This problem can be avoided in models where the dark mediator decays. This is illustrated by the neutrino portal for Skyrmion dark matter. (orig.)

  5. Collapsed Dark Matter Structures

    Science.gov (United States)

    Buckley, Matthew R.; DiFranzo, Anthony

    2018-02-01

    The distributions of dark matter and baryons in the Universe are known to be very different: The dark matter resides in extended halos, while a significant fraction of the baryons have radiated away much of their initial energy and fallen deep into the potential wells. This difference in morphology leads to the widely held conclusion that dark matter cannot cool and collapse on any scale. We revisit this assumption and show that a simple model where dark matter is charged under a "dark electromagnetism" can allow dark matter to form gravitationally collapsed objects with characteristic mass scales much smaller than that of a Milky-Way-type galaxy. Though the majority of the dark matter in spiral galaxies would remain in the halo, such a model opens the possibility that galaxies and their associated dark matter play host to a significant number of collapsed substructures. The observational signatures of such structures are not well explored but potentially interesting.

  6. Baryonic Dark Matter

    OpenAIRE

    Silk, Joseph

    1994-01-01

    In the first two of these lectures, I present the evidence for baryonic dark matter and describe possible forms that it may take. The final lecture discusses formation of baryonic dark matter, and sets the cosmological context.

  7. Dark matter detectors

    International Nuclear Information System (INIS)

    Forster, G.

    1995-01-01

    A fundamental question of astrophysics and cosmology is the nature of dark matter. Astrophysical observations show clearly the existence of some kind of dark matter, though they cannot yet reveal its nature. Dark matter can consist of baryonic particles, or of other (known or unknown) elementary particles. Baryonic dark matter probably exists in the form of dust, gas, or small stars. Other elementary particles constituting the dark matter can possibly be measured in terrestrial experiments. Possibilities for dark matter particles are neutrinos, axions and weakly interacting massive particles (WIMPs). While a direct detection of relic neutrinos seems at the moment impossible, there are experiments looking for baryonic dark matter in the form of Massive Compact Halo Objects, and for particle dark matter in the form of axions and WIMPS. (orig.)

  8. Collapsed Dark Matter Structures.

    Science.gov (United States)

    Buckley, Matthew R; DiFranzo, Anthony

    2018-02-02

    The distributions of dark matter and baryons in the Universe are known to be very different: The dark matter resides in extended halos, while a significant fraction of the baryons have radiated away much of their initial energy and fallen deep into the potential wells. This difference in morphology leads to the widely held conclusion that dark matter cannot cool and collapse on any scale. We revisit this assumption and show that a simple model where dark matter is charged under a "dark electromagnetism" can allow dark matter to form gravitationally collapsed objects with characteristic mass scales much smaller than that of a Milky-Way-type galaxy. Though the majority of the dark matter in spiral galaxies would remain in the halo, such a model opens the possibility that galaxies and their associated dark matter play host to a significant number of collapsed substructures. The observational signatures of such structures are not well explored but potentially interesting.

  9. Codecaying Dark Matter.

    Science.gov (United States)

    Dror, Jeff Asaf; Kuflik, Eric; Ng, Wee Hao

    2016-11-18

    We propose a new mechanism for thermal dark matter freeze-out, called codecaying dark matter. Multicomponent dark sectors with degenerate particles and out-of-equilibrium decays can codecay to obtain the observed relic density. The dark matter density is exponentially depleted through the decay of nearly degenerate particles rather than from Boltzmann suppression. The relic abundance is set by the dark matter annihilation cross section, which is predicted to be boosted, and the decay rate of the dark sector particles. The mechanism is viable in a broad range of dark matter parameter space, with a robust prediction of an enhanced indirect detection signal. Finally, we present a simple model that realizes codecaying dark matter.

  10. Living out our values: the legacy of Christian academic nursing leadership.

    Science.gov (United States)

    Coeling, Harriet V; Chiang-Hanisko, Lenny; Thompson, Mary

    2011-01-01

    Retired academic nursing leaders possess a rich legacy of knowledge. Using a grounded theory approach, knowledge possessed by 14 retired Christian Chairperson/Deans was explored. Two themes representing commitment to living out Christian values; and fortitude, understanding, and spiritual guidance emerged from written responses to open-ended survey questions.

  11. Dark Matter Effective Theory

    DEFF Research Database (Denmark)

    Del Nobile, Eugenio; Sannino, Francesco

    2012-01-01

    We organize the effective (self)interaction terms for complex scalar dark matter candidates which are either an isosinglet, isodoublet or an isotriplet with respect to the weak interactions. The classification has been performed ordering the operators in inverse powers of the dark matter cutoff...... scale. We assume Lorentz invariance, color and charge neutrality. We also introduce potentially interesting dark matter induced flavor-changing operators. Our general framework allows for model independent investigations of dark matter properties....

  12. Dark stars: a review.

    Science.gov (United States)

    Freese, Katherine; Rindler-Daller, Tanja; Spolyar, Douglas; Valluri, Monica

    2016-06-01

    Dark stars are stellar objects made (almost entirely) of hydrogen and helium, but powered by the heat from dark matter annihilation, rather than by fusion. They are in hydrostatic and thermal equilibrium, but with an unusual power source. Weakly interacting massive particles (WIMPs), among the best candidates for dark matter, can be their own antimatter and can annihilate inside the star, thereby providing a heat source. Although dark matter constitutes only [Formula: see text]0.1% of the stellar mass, this amount is sufficient to power the star for millions to billions of years. Thus, the first phase of stellar evolution in the history of the Universe may have been dark stars. We review how dark stars come into existence, how they grow as long as dark matter fuel persists, and their stellar structure and evolution. The studies were done in two different ways, first assuming polytropic interiors and more recently using the MESA stellar evolution code; the basic results are the same. Dark stars are giant, puffy (∼10 AU) and cool (surface temperatures  ∼10 000 K) objects. We follow the evolution of dark stars from their inception at  ∼[Formula: see text] as they accrete mass from their surroundings to become supermassive stars, some even reaching masses  >[Formula: see text] and luminosities  >[Formula: see text], making them detectable with the upcoming James Webb Space Telescope. Once the dark matter runs out and the dark star dies, it may collapse to a black hole; thus dark stars may provide seeds for the supermassive black holes observed throughout the Universe and at early times. Other sites for dark star formation may exist in the Universe today in regions of high dark matter density such as the centers of galaxies. The current review briefly discusses dark stars existing today, but focuses on the early generation of dark stars.

  13. Cosmological acceleration. Dark energy or modified gravity?

    Energy Technology Data Exchange (ETDEWEB)

    Bludman, S.

    2006-05-15

    We review the evidence for recently accelerating cosmological expansion or ''dark energy'', either a negative pressure constituent in General Relativity (Dark Energy) or modified gravity (Dark Gravity), without any constituent Dark Energy. If constituent Dark Energy does not exist, so that our universe is now dominated by pressure-free matter, Einstein gravity must be modified at low curvature. The vacuum symmetry of any Robertson-Walker universe then characterizes Dark Gravity as low- or high-curvature modifications of Einstein gravity. The dynamics of either kind of ''dark energy'' cannot be derived from the homogeneous expansion history alone, but requires also observing the growth of inhomogeneities. Present and projected observations are all consistent with a small fine tuned cosmological constant, but also allow nearly static Dark Energy or gravity modified at cosmological scales. The growth of cosmological fluctuations will potentially distinguish between static and ''dynamic'' ''dark energy''. But, cosmologically distinguishing the Concordance Model {lambda}CDM from modified gravity will require a weak lensing shear survey more ambitious than any now projected. Dvali-Gabadadze-Porrati low-curvature modifications of Einstein gravity may also be detected in refined observations in the solar system (Lue and Starkman) or at the intermediate Vainstein scale (Iorio) in isolated galaxy clusters. Dark Energy's epicyclic character, failure to explain the original Cosmic Coincidence (''Why so small now?'') without fine tuning, inaccessibility to laboratory or solar system tests, along with braneworld theories, now motivate future precision solar system, Vainstein-scale and cosmological-scale studies of Dark Gravity. (Orig.)

  14. Nonthermal Supermassive Dark Matter

    Science.gov (United States)

    Chung, Daniel J. H.; Kolb, Edward W.; Riotto, Antonio

    1999-01-01

    We discuss several cosmological production mechanisms for nonthermal supermassive dark matter and argue that dark matter may he elementary particles of mass much greater than the weak scale. Searches for dark matter should ma be limited to weakly interacting particles with mass of the order of the weak scale, but should extend into the supermassive range as well.

  15. Ultracool dwarf legacy science with ESA's Euclid mission

    Directory of Open Access Journals (Sweden)

    Martin E.L.

    2013-04-01

    Full Text Available Euclid is an medium-class ESA mission that will carry out a 5 year survey of the extragalactic sky. The science drivers for the survey are cosmological and extragalactic. Nevertheless, the unprecedented depth over such a large area and the diffraction limited spatial resolution of the Euclid survey will have a long lasting impact in many fields of Astrophysics. This paper outlines the legacy science that will come out from Euclid in the field of ultracool dwarfs. In particular, it is foreseen that Euclid will increase the number of resolved ultracool binaries by more than an order of magnitude, and hence it will provide a stringent constraint on models of formation of very low-mass objects. Euclid can also find significant number of rare objects such as young free-floating planets or population III ultracool dwarfs.

  16. Dark Mass Creation During EWPT Via Dark Energy Interaction

    OpenAIRE

    Kisslinger, Leonard S.; Casper, Steven

    2013-01-01

    We add Dark Matter Dark Energy terms with a quintessence field interacting with a Dark Matter field to a MSSM EW Lagrangian previously used to calculate the magnetic field created during the EWPT. From the expectation value of the quintessence field we estimate the Dark Matter mass for parameters used in previous work on Dark Matter-Dark Energy interactions.

  17. Relations between the Sizes of Galaxies and Their Dark Matter Halos at Redshifts 0 < z < 3

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Kuang-Han [University of California Davis, 1 Shields Avenue, Davis, CA 95616 (United States); Fall, S. Michael; Ferguson, Henry C.; Grogin, Norman; Koekemoer, Anton [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Van der Wel, Arjen [Max Planck Institute for Astronomy, Koenigstuhl 17, D-69117 Heidelberg (Germany); Lee, Seong-Kook [Center for the Exploration of the Origin of the Universe, Department of Physics and Astronomy, Seoul National University, Seoul (Korea, Republic of); Pérez-González, Pablo G. [Departamento de Astrofísica, Facultad de CC. Física, Universidad Complutense de Madrid, E-28040, Madrid (Spain); Wuyts, Stijn, E-mail: khhuang@ucdavis.edu [Department of Physics, University of Bath, Claverton Down, Bath, BA2 7AY (United Kingdom)

    2017-03-20

    We derive relations between the effective radii R {sub eff} of galaxies and the virial radii R {sub 200} {sub c} of their dark matter halos over the redshift range 0 < z < 3. For galaxies, we use the measured sizes from deep images taken with Hubble Space Telescope for the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey; for halos, we use the inferred sizes from abundance matching to cosmological dark matter simulations via a stellar mass–halo mass (SMHM) relation. For this purpose, we derive a new SMHM relation based on the same selection criteria and other assumptions as for our sample of galaxies with size measurements. As a check on the robustness of our results, we also derive R {sub eff}–R {sub 200} {sub c} relations for three independent SMHM relations from the literature. We find that galaxy R {sub eff} is proportional on average to halo R {sub 200} {sub c}, confirming and extending to high redshifts the z = 0 results of Kravtsov. Late-type galaxies (with low Sérsic index and high specific star formation rate (sSFR)) follow a linear R {sub eff}– R {sub 200} {sub c} relation, with effective radii at 0.5 < z < 3 close to those predicted by simple models of disk formation; at z < 0.5, the sizes of late-type galaxies appear to be slightly below this prediction. Early-type galaxies (with high Sérsic index and low sSFR) follow a roughly parallel R {sub eff}– R {sub 200} {sub c} relation, ∼0.2–0.3 dex below the one for late-type galaxies. Our observational results, reinforced by recent hydrodynamical simulations, indicate that galaxies grow quasi-homologously with their dark matter halos.

  18. Nitrate retention capacity of milldam-impacted legacy sediments and relict A horizon soils

    Directory of Open Access Journals (Sweden)

    J. N. Weitzman

    2017-05-01

    Full Text Available While eutrophication is often attributed to contemporary nutrient pollution, there is growing evidence that past practices, like the accumulation of legacy sediment behind historic milldams, are also important. Given their prevalence, there is a critical need to understand how N flows through, and is retained in, legacy sediments to improve predictions and management of N transport from uplands to streams in the context of climatic variability and land-use change. Our goal was to determine how nitrate (NO3− is cycled through the soil of a legacy-sediment-strewn stream before and after soil drying. We extracted 10.16 cm radius intact soil columns that extended 30 cm into each of the three significant soil horizons at Big Spring Run (BSR in Lancaster, Pennsylvania: surface legacy sediment characterized by a newly developing mineral A horizon soil, mid-layer legacy sediment consisting of mineral B horizon soil and a dark, organic-rich, buried relict A horizon soil. Columns were first preincubated at field capacity and then isotopically labeled nitrate (15NO3− was added and allowed to drain to estimate retention. The columns were then air-dried and subsequently rewet with N-free water and allowed to drain to quantify the drought-induced loss of 15NO3− from the different horizons. We found the highest initial 15N retention in the mid-layer legacy sediment (17 ± 4 % and buried relict A soil (14 ± 3 % horizons, with significantly lower retention in the surface legacy sediment (6 ± 1 % horizon. As expected, rewetting dry soil resulted in 15N losses in all horizons, with the greatest losses in the buried relict A horizon soil, followed by the mid-layer legacy sediment and surface legacy sediment horizons. The 15N remaining in the soil following the post-drought leaching was highest in the mid-layer legacy sediment, intermediate in the surface legacy sediment, and lowest in the buried relict A horizon soil. Fluctuations

  19. Interactions between dark energy and dark matter

    International Nuclear Information System (INIS)

    Baldi, Marco

    2009-01-01

    We have investigated interacting dark energy cosmologies both concerning their impact on the background evolution of the Universe and their effects on cosmological structure growth. For the former aspect, we have developed a cosmological model featuring a matter species consisting of particles with a mass that increases with time. In such model the appearance of a Growing Matter component, which is negligible in early cosmology, dramatically slows down the evolution of the dark energy scalar field at a redshift around six, and triggers the onset of the accelerated expansion of the Universe, therefore addressing the Coincidence Problem. We propose to identify this Growing Matter component with cosmic neutrinos, in which case the present dark energy density can be related to the measured average mass of neutrinos. For the latter aspect, we have implemented the new physical features of interacting dark energy models into the cosmological N-body code GADGET-2, and we present the results of a series of high-resolution simulations for a simple realization of dark energy interaction. As a consequence of the new physics, cold dark matter and baryon distributions evolve differently both in the linear and in the non-linear regime of structure formation. Already on large scales, a linear bias develops between these two components, which is further enhanced by the non-linear evolution. We also find, in contrast with previous work, that the density profiles of cold dark matter halos are less concentrated in coupled dark energy cosmologies compared with Λ CDM . Also, the baryon fraction in halos in the coupled models is significantly reduced below the universal baryon fraction. These features alleviate tensions between observations and the Λ CDM model on small scales. Our methodology is ideally suited to explore the predictions of coupled dark energy models in the fully non-linear regime, which can provide powerful constraints for the viable parameter space of such scenarios

  20. Interactions between dark energy and dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Baldi, Marco

    2009-03-20

    We have investigated interacting dark energy cosmologies both concerning their impact on the background evolution of the Universe and their effects on cosmological structure growth. For the former aspect, we have developed a cosmological model featuring a matter species consisting of particles with a mass that increases with time. In such model the appearance of a Growing Matter component, which is negligible in early cosmology, dramatically slows down the evolution of the dark energy scalar field at a redshift around six, and triggers the onset of the accelerated expansion of the Universe, therefore addressing the Coincidence Problem. We propose to identify this Growing Matter component with cosmic neutrinos, in which case the present dark energy density can be related to the measured average mass of neutrinos. For the latter aspect, we have implemented the new physical features of interacting dark energy models into the cosmological N-body code GADGET-2, and we present the results of a series of high-resolution simulations for a simple realization of dark energy interaction. As a consequence of the new physics, cold dark matter and baryon distributions evolve differently both in the linear and in the non-linear regime of structure formation. Already on large scales, a linear bias develops between these two components, which is further enhanced by the non-linear evolution. We also find, in contrast with previous work, that the density profiles of cold dark matter halos are less concentrated in coupled dark energy cosmologies compared with {lambda}{sub CDM}. Also, the baryon fraction in halos in the coupled models is significantly reduced below the universal baryon fraction. These features alleviate tensions between observations and the {lambda}{sub CDM} model on small scales. Our methodology is ideally suited to explore the predictions of coupled dark energy models in the fully non-linear regime, which can provide powerful constraints for the viable parameter

  1. Collapsed Dark Matter Structures

    OpenAIRE

    Buckley, Matthew R.; DiFranzo, Anthony

    2018-01-01

    The distributions of dark matter and baryons in the Universe are known to be very different: the dark matter resides in extended halos, while a significant fraction of the baryons have radiated away much of their initial energy and fallen deep into the potential wells. This difference in morphology leads to the widely held conclusion that dark matter cannot cool and collapse on any scale. We revisit this assumption, and show that a simple model where dark matter is charged under a "dark elect...

  2. Dark Matter Caustics

    International Nuclear Information System (INIS)

    Natarajan, Aravind

    2010-01-01

    The continuous infall of dark matter with low velocity dispersion in galactic halos leads to the formation of high density structures called caustics. Dark matter caustics are of two kinds : outer and inner. Outer caustics are thin spherical shells surrounding galaxies while inner caustics have a more complicated structure that depends on the dark matter angular momentum distribution. The presence of a dark matter caustic in the plane of the galaxy modifies the gas density in its neighborhood which may lead to observable effects. Caustics are also relevant to direct and indirect dark matter searches.

  3. Hunting the dark Higgs

    International Nuclear Information System (INIS)

    Duerr, Michael; Grohsjean, Alexander; Kahlhoefer, Felix; Schmidt-Hoberg, Kai; Schwanenberger, Christian; Penning, Bjoern

    2017-05-01

    We discuss a novel signature of dark matter production at the LHC resulting from the emission of an additional Higgs boson in the dark sector. The presence of such a dark Higgs boson is motivated simultaneously by the need to generate the masses of the particles in the dark sector and the possibility to relax constraints from the dark matter relic abundance by opening up a new annihilation channel. If the dark Higgs boson decays into Standard Model states via a small mixing with the Standard Model Higgs boson, one obtains characteristic large-radius jets in association with missing transverse momentum that can be used to efficiently discriminate signal from backgrounds. We present the sensitivities achievable in LHC searches for dark Higgs bosons with already collected data and demonstrate that such searches can probe large regions of parameter space that are inaccessible to conventional mono-jet or di-jet searches.

  4. Assisted Emulation for Legacy Executables

    Directory of Open Access Journals (Sweden)

    Kam Woods

    2010-07-01

    Full Text Available Emulation is frequently discussed as a failsafe preservation strategy for born-digital documents that depend on contemporaneous software for access (Rothenberg, 2000. Yet little has been written about the contextual knowledge required to successfully use such software. The approach we advocate is to preserve necessary contextual information through scripts designed to control the legacy environment, and created during the preservation workflow. We describe software designed to minimize dependence on this knowledge by offering automated configuration and execution of emulated environments. We demonstrate that even simple scripts can reduce impediments to casual use of the digital objects being preserved. We describe tools to automate the remote use of preserved objects on local emulation environments.  This can help eliminate both a dependence on physical reference workstations at preservation institutions, and provide users accessing materials over the web with simplified, easy-to-use environments. Our implementation is applied to examples from an existing collection of over 4,000 virtual CD-ROM images containing thousands of custom binary executables.

  5. Dark nebulae, dark lanes, and dust belts

    CERN Document Server

    Cooke, Antony

    2012-01-01

    As probably the only book of its type, this work is aimed at the observer who wants to spend time with something less conventional than the usual fare. Because we usually see objects in space by means of illumination of one kind or another, it has become routine to see them only in these terms. However, part of almost everything that we see is the defining dimension of dark shading, or even the complete obscuration of entire regions in space. Thus this book is focused on everything dark in space: those dark voids in the stellar fabric that mystified astronomers of old; the dark lanes reported in many star clusters; the magical dust belts or dusty regions that have given so many galaxies their identities; the great swirling 'folds' that we associate with bright nebulae; the small dark feature detectable even in some planetary nebulae; and more. Many observers pay scant attention to dark objects and details. Perhaps they are insufficiently aware of them or of the viewing potential they hold, but also it may be...

  6. Hidden charged dark matter

    International Nuclear Information System (INIS)

    Feng, Jonathan L.; Kaplinghat, Manoj; Tu, Huitzu; Yu, Hai-Bo

    2009-01-01

    Can dark matter be stabilized by charge conservation, just as the electron is in the standard model? We examine the possibility that dark matter is hidden, that is, neutral under all standard model gauge interactions, but charged under an exact (\\rm U)(1) gauge symmetry of the hidden sector. Such candidates are predicted in WIMPless models, supersymmetric models in which hidden dark matter has the desired thermal relic density for a wide range of masses. Hidden charged dark matter has many novel properties not shared by neutral dark matter: (1) bound state formation and Sommerfeld-enhanced annihilation after chemical freeze out may reduce its relic density, (2) similar effects greatly enhance dark matter annihilation in protohalos at redshifts of z ∼ 30, (3) Compton scattering off hidden photons delays kinetic decoupling, suppressing small scale structure, and (4) Rutherford scattering makes such dark matter self-interacting and collisional, potentially impacting properties of the Bullet Cluster and the observed morphology of galactic halos. We analyze all of these effects in a WIMPless model in which the hidden sector is a simplified version of the minimal supersymmetric standard model and the dark matter is a hidden sector stau. We find that charged hidden dark matter is viable and consistent with the correct relic density for reasonable model parameters and dark matter masses in the range 1 GeV ∼ X ∼< 10 TeV. At the same time, in the preferred range of parameters, this model predicts cores in the dark matter halos of small galaxies and other halo properties that may be within the reach of future observations. These models therefore provide a viable and well-motivated framework for collisional dark matter with Sommerfeld enhancement, with novel implications for astrophysics and dark matter searches

  7. Tagore’s Dark Vision of Humanity

    Directory of Open Access Journals (Sweden)

    Alok BHALLA

    2013-04-01

    Full Text Available Tagore struggled against his dark vision of humanity to assert that the earth was a place of hierophanies and human life had a divine purpose. He failed. He called, with skepticism, for peace, equality and the restoration of earth’s loveliness: “I know I am crying in the wilderness, when I raise my voice of warning…” In a war-haunted and hungry Europe and Asia, he was confronted by a strange, cruel, and obstinately tribal world with its “legacy of ruin.” Though he asserted till his death in 1940 that he could never “commit the grievous sin of losing faith in man,” he could not turn away from “the crumbling ruins of … civilization….”

  8. The relationship between galaxy and dark matter halo size from z ˜ 3 to the present

    Science.gov (United States)

    Somerville, Rachel S.; Behroozi, Peter; Pandya, Viraj; Dekel, Avishai; Faber, S. M.; Fontana, Adriano; Koekemoer, Anton M.; Koo, David C.; Pérez-González, P. G.; Primack, Joel R.; Santini, Paola; Taylor, Edward N.; van der Wel, Arjen

    2018-01-01

    We explore empirical constraints on the statistical relationship between the radial size of galaxies and the radius of their host dark matter haloes from z ∼ 0.1-3 using the Galaxy And Mass Assembly (GAMA) and Cosmic Assembly Near Infrared Deep Extragalactic Legacy Survey (CANDELS) surveys. We map dark matter halo mass to galaxy stellar mass using relationships from abundance matching, applied to the Bolshoi-Planck dissipationless N-body simulation. We define SRHR ≡ re/Rh as the ratio of galaxy radius to halo virial radius, and SRHRλ ≡ re/(λRh) as the ratio of galaxy radius to halo spin parameter times halo radius. At z ∼ 0.1, we find an average value of SRHR ≃ 0.018 and SRHRλ ≃ 0.5 with very little dependence on stellar mass. Stellar radius-halo radius (SRHR) and SRHRλ have a weak dependence on cosmic time since z ∼ 3. SRHR shows a mild decrease over cosmic time for low-mass galaxies, but increases slightly or does not evolve for more massive galaxies. We find hints that at high redshift (z ∼ 2-3), SRHRλ is lower for more massive galaxies, while it shows no significant dependence on stellar mass at z ≲ 0.5. We find that for both the GAMA and CANDELS samples, at all redshifts from z ∼ 0.1-3, the observed conditional size distribution in stellar mass bins is remarkably similar to the conditional distribution of λRh. We discuss the physical interpretation and implications of these results.

  9. Legacy material work-off project

    International Nuclear Information System (INIS)

    Sloan, T.J.; Baker, D.H. IV

    1999-01-01

    Los Alamos National Laboratory (LANL) and its subcontractors recently completed a nine-month legacy material clean-up effort. Legacy materials were defined as chemicals, hazardous, non-hazardous, and both hazardous and radioactive (mixed), that no longer served a programmatic use and had no identified individual owner within the Laboratory. Once personnel identified the legacy materials, the items were transferred to Solid Waste Operation's (EM-SWO) control. Upon completing this process, the responsible division-level manager was required to certify that all non-radioactive hazardous and non-hazardous materials and acceptable mixed legacy materials had been identified and transferred to EM-SWO for proper handling or disposal. The major expense in this project was the cost of actual chemical and radiological analysis. This expense was the result of items not having an identified individual owner. The major benefit of this project is that LANL is now in an excellent position to implement its Integrated Safety Management (ISM) Plan, which requires the implementation of safe work practices, including requirements for removing unused items when vacating workspaces. Effective implementation of ISM will go a long way toward ensuring that legacy materials are no longer an issue at the Laboratory

  10. Observational constraints on dark matter-dark energy scattering cross section

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Suresh [BITS Pilani, Department of Mathematics, Rajasthan (India); Nunes, Rafael C. [Universidade Federal de Juiz de Fora, Departamento de Fisica, Juiz de Fora, MG (Brazil)

    2017-11-15

    In this letter, we report precise and robust observational constraints on the dark matter-dark energy scattering cross section, using the latest data from cosmic microwave background (CMB) Planck temperature and polarization, baryon acoustic oscillations (BAO) measurements and weak gravitational lensing data from Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS). The scattering scenario consists of a pure momentum exchange between the dark components, and we find σ{sub d} < 10{sup -29} cm{sup 2} (m{sub dm}c{sup 2}/GeV) at 95% CL from the joint analysis (CMB + BAO + CFHTLenS), where m{sub dm} is a typical dark matter particle mass. We notice that the scattering among the dark components may influence the growth of large scale structure in the Universe, leaving the background cosmology unaltered. (orig.)

  11. Dark matter an introduction

    CERN Document Server

    Majumdar, Debasish

    2015-01-01

    Dark Matter: An Introduction tackles the rather recent but fast-growing subject of astroparticle physics, encompassing three main areas of fundamental physics: cosmology, particle physics, and astrophysics. Accordingly, the book discusses symmetries, conservation laws, relativity, and cosmological parameters and measurements, as well as the astrophysical behaviors of galaxies and galaxy clusters that indicate the presence of dark matter and the possible nature of dark matter distribution.

  12. Interacting warm dark matter

    International Nuclear Information System (INIS)

    Cruz, Norman; Palma, Guillermo; Zambrano, David; Avelino, Arturo

    2013-01-01

    We explore a cosmological model composed by a dark matter fluid interacting with a dark energy fluid. The interaction term has the non-linear λρ m α ρ e β form, where ρ m and ρ e are the energy densities of the dark matter and dark energy, respectively. The parameters α and β are in principle not constrained to take any particular values, and were estimated from observations. We perform an analytical study of the evolution equations, finding the fixed points and their stability properties in order to characterize suitable physical regions in the phase space of the dark matter and dark energy densities. The constants (λ,α,β) as well as w m and w e of the EoS of dark matter and dark energy respectively, were estimated using the cosmological observations of the type Ia supernovae and the Hubble expansion rate H(z) data sets. We find that the best estimated values for the free parameters of the model correspond to a warm dark matter interacting with a phantom dark energy component, with a well goodness-of-fit to data. However, using the Bayesian Information Criterion (BIC) we find that this model is overcame by a warm dark matter – phantom dark energy model without interaction, as well as by the ΛCDM model. We find also a large dispersion on the best estimated values of the (λ,α,β) parameters, so even if we are not able to set strong constraints on their values, given the goodness-of-fit to data of the model, we find that a large variety of theirs values are well compatible with the observational data used

  13. Clumpy cold dark matter

    Science.gov (United States)

    Silk, Joseph; Stebbins, Albert

    1993-01-01

    A study is conducted of cold dark matter (CDM) models in which clumpiness will inhere, using cosmic strings and textures suited to galaxy formation. CDM clumps of 10 million solar mass/cu pc density are generated at about z(eq) redshift, with a sizable fraction surviving. Observable implications encompass dark matter cores in globular clusters and in galactic nuclei. Results from terrestrial dark matter detection experiments may be affected by clumpiness in the Galactic halo.

  14. Age and leadership : The moderating role of legacy beliefs

    NARCIS (Netherlands)

    Zacher, Hannes; Rosing, Kathrin; Frese, Michael

    Age and age-related motivations have been neglected in leadership research. This study examined the moderating influence of legacy beliefs on the relationships between age and transformational, transactional, and passive-avoidant leadership behaviors. Legacy beliefs involve individuals' convictions

  15. Asymmetric Dark Matter and Dark Radiation

    International Nuclear Information System (INIS)

    Blennow, Mattias; Martinez, Enrique Fernandez; Mena, Olga; Redondo, Javier; Serra, Paolo

    2012-01-01

    Asymmetric Dark Matter (ADM) models invoke a particle-antiparticle asymmetry, similar to the one observed in the Baryon sector, to account for the Dark Matter (DM) abundance. Both asymmetries are usually generated by the same mechanism and generally related, thus predicting DM masses around 5 GeV in order to obtain the correct density. The main challenge for successful models is to ensure efficient annihilation of the thermally produced symmetric component of such a light DM candidate without violating constraints from collider or direct searches. A common way to overcome this involves a light mediator, into which DM can efficiently annihilate and which subsequently decays into Standard Model particles. Here we explore the scenario where the light mediator decays instead into lighter degrees of freedom in the dark sector that act as radiation in the early Universe. While this assumption makes indirect DM searches challenging, it leads to signals of extra radiation at BBN and CMB. Under certain conditions, precise measurements of the number of relativistic species, such as those expected from the Planck satellite, can provide information on the structure of the dark sector. We also discuss the constraints of the interactions between DM and Dark Radiation from their imprint in the matter power spectrum

  16. Chaplygin dark star

    International Nuclear Information System (INIS)

    Bertolami, O.; Paramos, J.

    2005-01-01

    We study the general properties of a spherically symmetric body described through the generalized Chaplygin equation of state. We conclude that such an object, dubbed generalized Chaplygin dark star, should exist within the context of the generalized Chaplygin gas (GCG) model of unification of dark energy and dark matter, and derive expressions for its size and expansion velocity. A criteria for the survival of the perturbations in the GCG background that give origin to the dark star are developed, and its main features are analyzed

  17. Wandering in the Lyman-alpha forest: a study of dark matter-dark radiation interactions

    International Nuclear Information System (INIS)

    Krall, Rebecca; Cyr-Racine, Francis-Yan; Dvorkin, Cora

    2017-01-01

    The amplitude of large-scale matter fluctuations inferred from the observed Sunyaev-Zeldovich (SZ) cluster mass function and from weak gravitational lensing studies, when taken at face value, is in tension with measurements of the cosmic microwave background (CMB) and baryon acoustic oscillation (BAO). In this work, we revisit whether this possible discrepancy can be attributed to new interactions in the dark matter sector. Focusing on a cosmological model where dark matter interacts with a dark radiation species until the epoch of matter-radiation equality, we find that measurements of the Lyman-alpha flux power spectrum from the Sloan Digital Sky Survey provide no support to the hypothesis that new dark matter interactions can resolve the possible tension between CMB and large-scale structure (LSS). Indeed, while the addition of dark matter-dark radiation interactions leads to an improvement of 2ΔlnL=12 with respect to the standard Λ cold dark matter (ΛCDM) model when only CMB, BAO, and LSS data are considered, the inclusion of Lyman-alpha data reduces the improvement of the fit to 2ΔlnL=6 relative to ΛCDM . We thus conclude that the statistical evidence for new dark matter interactions (largely driven by the Planck SZ dataset) is marginal at best, and likely caused by systematics in the data. We also perform a Fisher forecast analysis for the reach of a future dataset composed of a CMB-S4 experiment combined with the Large Synoptic Survey Telescope galaxy survey. We find that the constraint on the effective number of fluid-like dark radiation species, Δ N fluid , will be improved by an order of magnitude compared to current bounds.

  18. Galaxy-galaxy lensing constraints on the relation between baryons and dark matter in galaxies in the Red Sequence Cluster Survey 2

    OpenAIRE

    van Uitert, Edo; Hoekstra, Henk; Velander, Malin; Gilbank, David G.; Gladders, Michael D.; Yee, H. K. C.

    2011-01-01

    We present the results of a study of weak gravitational lensing by galaxies using imaging data that were obtained as part of the second Red Sequence Cluster Survey (RCS2). In order to compare to the baryonic properties of the lenses we focus here on the ~300 square degrees that overlap with the DR7 of the SDSS. The depth and image quality of the RCS2 enables us to significantly improve upon earlier work for luminous galaxies at z>=0.3. Comparison with dynamical masses from the SDSS shows a go...

  19. The radiation legacy of Russia

    International Nuclear Information System (INIS)

    Lebedev, V.A.

    2002-01-01

    Nuclear weapons making and testing, operation of enterprises of the nuclear industry, of military and civilian nuclear fleet, as well as peaceful nuclear explosions -- all that led in the USSR to release of radioactive products into the environment. In some parts of the FSU radioactive contamination exceeded permissible levels. The necessity of remediation of such territories became evident. The most part of the contamination resulted from major radiation accidents in Kyshtym (19570 and Chernobyl (1986). Today those objects, as well as some sites of radwaste storage and disposal, written-off nuclear submarines with non-unloaded spent nuclear fuel, some floating and on-shore repositories of nuclear fleet's radwaste and spent nuclear fuel, pose a potential hazard to the biosphere. Appropriate measures aimed at decreasing their impact on the population and environment are needed. Such measures should include both restoration of contaminated lands and social support programs for the population affected by radiation. The main task of the rehabilitation is reduction of consequences of internal and external exposure of the people, creation of necessary conditions for efficient and safe economical activities. Concrete objectives should be determined, as well as principles and standards to ensure radiation safety when conducting remediation works, and also -- specifications for evaluation of the lands condition prior to their remediation, criteria of decision making, rehabilitation planning, techniques of the lands' restoration and recommendations for their future uses. The Russian Federal special program 'Radioactive Waste and Spent Nuclear Materials Management, Utilization and Disposal for 1996-2005' envisages studies on Russia's radiation legacy's assessment on the basis of up-to-date information technologies of computer-based systems for data collection, storage and processing for accounting and analysis of information on availability, origin, physical and chemical

  20. Interacting dark matter and dark radiation

    Science.gov (United States)

    Tang, Yong

    2017-05-01

    We give a brief review on the interacting Dark Matter (iDM) scenario and its effects on cosmology and particle physics. If DM candidates can have strong self-interactions or interactions with other relativistic particles, we can refer them generally as iDM. IDM is an interesting possibility that is motivated both theoretically and observationally. The relativistic particles could belong to Standard Model (SM), such as photons and neutrinos, or be dark radiation (DR) in new physics. The resulting perturbed Boltzmann equations are concisely discussed and illustrations on matter power spectrum are given.

  1. Cosmology with cluster surveys

    Indian Academy of Sciences (India)

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

  2. Cosmology with cluster surveys

    Indian Academy of Sciences (India)

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

  3. Asymmetric dark matter

    International Nuclear Information System (INIS)

    Kaplan, David E.; Luty, Markus A.; Zurek, Kathryn M.

    2009-01-01

    We consider a simple class of models in which the relic density of dark matter is determined by the baryon asymmetry of the Universe. In these models a B-L asymmetry generated at high temperatures is transferred to the dark matter, which is charged under B-L. The interactions that transfer the asymmetry decouple at temperatures above the dark matter mass, freezing in a dark matter asymmetry of order the baryon asymmetry. This explains the observed relation between the baryon and dark matter densities for the dark matter mass in the range 5-15 GeV. The symmetric component of the dark matter can annihilate efficiently to light pseudoscalar Higgs particles a or via t-channel exchange of new scalar doublets. The first possibility allows for h 0 →aa decays, while the second predicts a light charged Higgs-like scalar decaying to τν. Direct detection can arise from Higgs exchange in the first model or a nonzero magnetic moment in the second. In supersymmetric models, the would-be lightest supersymmetric partner can decay into pairs of dark matter particles plus standard model particles, possibly with displaced vertices.

  4. Baryonic Dark Matter

    OpenAIRE

    De Paolis, F.; Jetzer, Ph.; Ingrosso, G.; Roncadelli, M.

    1997-01-01

    Reasons supporting the idea that most of the dark matter in galaxies and clusters of galaxies is baryonic are discussed. Moreover, it is argued that most of the dark matter in galactic halos should be in the form of MACHOs and cold molecular clouds.

  5. The Dark Matter Problem

    NARCIS (Netherlands)

    Sanders, Robert H.

    1. Introduction; 2. Early history of the dark matter hypothesis; 3. The stability of disk galaxies: the dark halo solutions; 4. Direct evidence: extended rotation curves of spiral galaxies; 5. The maximum disk: light traces mass; 6. Cosmology and the birth of astroparticle physics; 7. Clusters

  6. Asymptotically Safe Dark Matter

    DEFF Research Database (Denmark)

    Sannino, Francesco; Shoemaker, Ian M.

    2015-01-01

    We introduce a new paradigm for dark matter (DM) interactions in which the interaction strength is asymptotically safe. In models of this type, the coupling strength is small at low energies but increases at higher energies, and asymptotically approaches a finite constant value. The resulting...... searches are the primary ways to constrain or discover asymptotically safe dark matter....

  7. A galaxy lacking dark matter

    Science.gov (United States)

    van Dokkum, Pieter; Danieli, Shany; Cohen, Yotam; Merritt, Allison; Romanowsky, Aaron J.; Abraham, Roberto; Brodie, Jean; Conroy, Charlie; Lokhorst, Deborah; Mowla, Lamiya; O'Sullivan, Ewan; Zhang, Jielai

    2018-03-01

    Studies of galaxy surveys in the context of the cold dark matter paradigm have shown that the mass of the dark matter halo and the total stellar mass are coupled through a function that varies smoothly with mass. Their average ratio Mhalo/Mstars has a minimum of about 30 for galaxies with stellar masses near that of the Milky Way (approximately 5 × 1010 solar masses) and increases both towards lower masses and towards higher masses. The scatter in this relation is not well known; it is generally thought to be less than a factor of two for massive galaxies but much larger for dwarf galaxies. Here we report the radial velocities of ten luminous globular-cluster-like objects in the ultra-diffuse galaxy NGC1052–DF2, which has a stellar mass of approximately 2 × 108 solar masses. We infer that its velocity dispersion is less than 10.5 kilometres per second with 90 per cent confidence, and we determine from this that its total mass within a radius of 7.6 kiloparsecs is less than 3.4 × 108 solar masses. This implies that the ratio Mhalo/Mstars is of order unity (and consistent with zero), a factor of at least 400 lower than expected. NGC1052–DF2 demonstrates that dark matter is not always coupled with baryonic matter on galactic scales.

  8. A galaxy lacking dark matter.

    Science.gov (United States)

    van Dokkum, Pieter; Danieli, Shany; Cohen, Yotam; Merritt, Allison; Romanowsky, Aaron J; Abraham, Roberto; Brodie, Jean; Conroy, Charlie; Lokhorst, Deborah; Mowla, Lamiya; O'Sullivan, Ewan; Zhang, Jielai

    2018-03-28

    Studies of galaxy surveys in the context of the cold dark matter paradigm have shown that the mass of the dark matter halo and the total stellar mass are coupled through a function that varies smoothly with mass. Their average ratio M halo /M stars has a minimum of about 30 for galaxies with stellar masses near that of the Milky Way (approximately 5 × 10 10 solar masses) and increases both towards lower masses and towards higher masses. The scatter in this relation is not well known; it is generally thought to be less than a factor of two for massive galaxies but much larger for dwarf galaxies. Here we report the radial velocities of ten luminous globular-cluster-like objects in the ultra-diffuse galaxy NGC1052-DF2, which has a stellar mass of approximately 2 × 10 8 solar masses. We infer that its velocity dispersion is less than 10.5 kilometres per second with 90 per cent confidence, and we determine from this that its total mass within a radius of 7.6 kiloparsecs is less than 3.4 × 10 8 solar masses. This implies that the ratio M halo /M stars is of order unity (and consistent with zero), a factor of at least 400 lower than expected. NGC1052-DF2 demonstrates that dark matter is not always coupled with baryonic matter on galactic scales.

  9. Enabling forbidden dark matter

    Science.gov (United States)

    Cline, James M.; Liu, Hongwan; Slatyer, Tracy R.; Xue, Wei

    2017-10-01

    The thermal relic density of dark matter is conventionally set by two-body annihilations. We point out that in many simple models, 3 →2 annihilations can play an important role in determining the relic density over a broad range of model parameters. This occurs when the two-body annihilation is kinematically forbidden, but the 3 →2 process is allowed; we call this scenario not-forbidden dark matter. We illustrate this mechanism for a vector-portal dark matter model, showing that for a dark matter mass of mχ˜MeV -10 GeV , 3 →2 processes not only lead to the observed relic density, but also imply a self-interaction cross section that can solve the cusp/core problem. This can be accomplished while remaining consistent with stringent CMB constraints on light dark matter, and can potentially be discovered at future direct detection experiments.

  10. Macro Dark Matter

    CERN Document Server

    Jacobs, David M; Lynn, Bryan W.

    2015-01-01

    Dark matter is a vital component of the current best model of our universe, $\\Lambda$CDM. There are leading candidates for what the dark matter could be (e.g. weakly-interacting massive particles, or axions), but no compelling observational or experimental evidence exists to support these particular candidates, nor any beyond-the-Standard-Model physics that might produce such candidates. This suggests that other dark matter candidates, including ones that might arise in the Standard Model, should receive increased attention. Here we consider a general class of dark matter candidates with characteristic masses and interaction cross-sections characterized in units of grams and cm$^2$, respectively -- we therefore dub these macroscopic objects as Macros. Such dark matter candidates could potentially be assembled out of Standard Model particles (quarks and leptons) in the early universe. A combination of earth-based, astrophysical, and cosmological observations constrain a portion of the Macro parameter space; ho...

  11. Dark cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Ping-Kai, E-mail: pingkai.hu@physics.ucla.edu [Department of Physics and Astronomy, University of California, Los Angeles, Los Angeles, CA 90095-1547 (United States); Kusenko, Alexander, E-mail: kusenko@ucla.edu [Department of Physics and Astronomy, University of California, Los Angeles, Los Angeles, CA 90095-1547 (United States); Kavli Institute for the Physics and Mathematics of the Universe (WPI), UTIAS, The University of Tokyo, Kashiwa, Chiba 277-8583 (Japan); Takhistov, Volodymyr, E-mail: vtakhist@physics.ucla.edu [Department of Physics and Astronomy, University of California, Los Angeles, Los Angeles, CA 90095-1547 (United States); Department of Physics and Astronomy, University of California, Irvine, Irvine, CA 92697-4575 (United States)

    2017-05-10

    If dark matter particles have an electric charge, as in models of millicharged dark matter, such particles should be accelerated in the same astrophysical accelerators that produce ordinary cosmic rays, and their spectra should have a predictable rigidity dependence. Depending on the charge, the resulting “dark cosmic rays” can be detected as muon-like or neutrino-like events in Super-Kamiokande, IceCube, and other detectors. We present new limits and propose several new analyses, in particular, for the Super-Kamiokande experiment, which can probe a previously unexplored portion of the millicharged dark matter parameter space. Most of our results are fairly general and apply to a broad class of dark matter models.

  12. Dark cosmic rays

    Directory of Open Access Journals (Sweden)

    Ping-Kai Hu

    2017-05-01

    Full Text Available If dark matter particles have an electric charge, as in models of millicharged dark matter, such particles should be accelerated in the same astrophysical accelerators that produce ordinary cosmic rays, and their spectra should have a predictable rigidity dependence. Depending on the charge, the resulting “dark cosmic rays” can be detected as muon-like or neutrino-like events in Super-Kamiokande, IceCube, and other detectors. We present new limits and propose several new analyses, in particular, for the Super-Kamiokande experiment, which can probe a previously unexplored portion of the millicharged dark matter parameter space. Most of our results are fairly general and apply to a broad class of dark matter models.

  13. Fingerprinting Dark Energy

    CERN Document Server

    Sapone, Domenico

    2009-01-01

    Dark energy perturbations are normally either neglected or else included in a purely numerical way, obscuring their dependence on underlying parameters like the equation of state or the sound speed. However, while many different explanations for the dark energy can have the same equation of state, they usually differ in their perturbations so that these provide a fingerprint for distinguishing between different models with the same equation of state. In this paper we derive simple yet accurate approximations that are able to characterize a specific class of models (encompassing most scalar field models) which is often generically called "dark energy". We then use the approximate solutions to look at the impact of the dark energy perturbations on the dark matter power spectrum and on the integrated Sachs-Wolfe effect in the cosmic microwave background radiation.

  14. Resonant SIMP dark matter

    Directory of Open Access Journals (Sweden)

    Soo-Min Choi

    2016-07-01

    Full Text Available We consider a resonant SIMP dark matter in models with two singlet complex scalar fields charged under a local dark U(1D. After the U(1D is broken down to a Z5 discrete subgroup, the lighter scalar field becomes a SIMP dark matter which has the enhanced 3→2 annihilation cross section near the resonance of the heavier scalar field. Bounds on the SIMP self-scattering cross section and the relic density can be fulfilled at the same time for perturbative couplings of SIMP. A small gauge kinetic mixing between the SM hypercharge and dark gauge bosons can be used to make SIMP dark matter in kinetic equilibrium with the SM during freeze-out.

  15. SURVEY

    DEFF Research Database (Denmark)

    SURVEY er en udbredt metode og benyttes inden for bl.a. samfundsvidenskab, humaniora, psykologi og sundhedsforskning. Også uden for forskningsverdenen er der mange organisationer som f.eks. konsulentfirmaer og offentlige institutioner samt marketingsafdelinger i private virksomheder, der arbejder...... med surveys. Denne bog gennemgår alle surveyarbejdets faser og giver en praktisk indføring i: • design af undersøgelsen og udvælgelse af stikprøver, • formulering af spørgeskemaer samt indsamling og kodning af data, • metoder til at analysere resultaterne...

  16. The Timeless Legacy of Robert Koch

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 11; Issue 9. The Timeless Legacy of Robert Koch - Founder of Medical Microbiology. Jaya S Tyagi. General Article Volume 11 Issue 9 September 2006 pp 20-28. Fulltext. Click here to view fulltext PDF. Permanent link:

  17. The Legacy of 1789: Part 2.

    Science.gov (United States)

    Kirkaldy, James

    1990-01-01

    Honoring the French Revolution's bicentennial, examines its legacy for modern France. Contends that 1789's imprint appears in France's centralized bureaucracy, strong political divisions (conservative-liberal-socialist), church-state separation, and tendency for government to argue ends justify means. Maintains the Revolution also spawned…

  18. George Peabody's (1795-1869) Educational Legacy.

    Science.gov (United States)

    Parker, Franklin; Parker, Betty J.

    During his career, George Peabody financially supported educational endeavors and went beyond the accumulation of money to leave for one's children. His support began in the mid-1800s and his educational legacy remains. He established: (1) a $2 million Peabody Education Fund to promote public schools and teacher training in 12 civil war devastated…

  19. Christian Social Justice Advocate: Contradiction or Legacy?

    Science.gov (United States)

    Edwards, Cher N.

    2012-01-01

    In this article, the relationship between Christian religiosity and the principles of social justice is explored, including the sociopolitical aspects of faith and advocacy. A particular emphasis is placed on the historical legacy and theological relationships between Christianity and social justice. The author concludes with a call for…

  20. Asutosh Mukhopadhyay and his Mathematical Legacy

    Indian Academy of Sciences (India)

    IAS Admin

    In this article, we describe the life and career of the versatile genius, Asutosh Mukhopadhyay. The article offers a few glimpses of his mathe- matical talent and contributions to mathemat- ics, and of his efforts to propagate and foster the study of and research in mathematics. 1. Introduction. The legacy of Asutosh ...

  1. Fundamental Considerations for Biobank Legacy Planning

    Science.gov (United States)

    Fombonne, Benjamin; Watson, Peter Hamilton; Moore, Helen Marie

    2016-01-01

    Biobanking in its various forms is an activity involving the collection of biospecimens and associated data and their storage for differing lengths of time before use. In some cases, biospecimens are immediately used, but in others, they are stored typically for the term of a specified project or in perpetuity until the materials are used up or declared to be of little scientific value. Legacy planning involves preparing for the phase that follows either biobank closure or a significant change at an operational level. In the case of a classical finite collection, this may be brought about by the completion of the initial scientific goals of a project, a loss of funding, or loss of or change in leadership. Ultimately, this may require making a decision about when and where to transfer materials or whether to destroy them. Because biobanking in its entirety is a complex endeavour, legacy planning touches on biobank operations as well as ethical, legal, financial, and governance parameters. Given the expense and time that goes into setting up and maintaining biobanks, coupled with the ethical imperative to appropriately utilize precious resources donated to research, legacy planning is an activity that every biobanking entity should think about. This article describes some of the fundamental considerations for preparing and executing a legacy plan, and we envisage that this article will facilitate dialogue to help inform best practices and policy development in the future. PMID:26890981

  2. Dark Matter Benchmark Models for Early LHC Run-2 Searches. Report of the ATLAS/CMS Dark Matter Forum

    Energy Technology Data Exchange (ETDEWEB)

    Abercrombie, Daniel [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). et al.

    2015-07-06

    One of the guiding principles of this report is to channel the efforts of the ATLAS and CMS collaborations towards a minimal basis of dark matter models that should influence the design of the early Run-2 searches. At the same time, a thorough survey of realistic collider signals of Dark Matter is a crucial input to the overall design of the search program.

  3. Galaxies in x-ray selected clusters and groups in Dark Energy Survey Data I: Stellar mass growth of bright central galaxies since Z similar to 1.2

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y.; Miller, C.; McKay, T.; Rooney, P.; Evrard, A. E.; Romer, A. K.; Perfecto, R.; Song, J; Desai, S.; Mohr, J. J.; Vikram, V.

    2016-01-10

    Using the science verification data of the Dark Energy Survey for a new sample of 106 X-ray selected clusters and groups, we study the stellar mass growth of bright central galaxies (BCGs) since redshift z similar to 1.2. Compared with the expectation in a semi-analytical model applied to the Millennium Simulation, the observed BCGs become under-massive/under-luminous with decreasing redshift. We incorporate the uncertainties associated with cluster mass, redshift, and BCG stellar mass measurements into an analysis of a redshift-dependent BCG-cluster mass relation, m(*) proportional to (M-200/1.5 x 10(14)M(circle dot))(0.24 +/- 0.08)(1+z)(-0.19 +/- 0.34), and compare the observed relation to the model prediction. We estimate the average growth rate since z = 1.0 for BCGs hosted by clusters of M-200,M-z = 10(13.8)M(circle dot); at z = 1.0: m(*, BCG) appears to have grown by 0.13 +/- 0.11 dex, in tension at the similar to 2.5 sigma significance level with the 0.40 dex growth rate expected from the semi-analytic model. We show that the build-up of extended intracluster light after z = 1.0 may alleviate this tension in BCG growth rates.

  4. Sustainable legacies for the 2012 Olympic Games.

    Science.gov (United States)

    Shipway, Richard

    2007-05-01

    The London 2012 Olympic and Paralympic Games have the unique potential to deliver sustainable sporting, social, cultural, economic and environmental legacies, not just for London as the host city, but for the whole of Britain. This article focuses primarily on the first three of these potential Olympics legacies. The first area explored is the social legacy as it impacts on host communities; second, the potential educational and cultural legacy of the 2012 Games are examined; and finally, there follows an overview of the health benefits that could result from a sustained increase in mass participation in sport, physical activity and exercise. This appraisal is undertaken through a review of existing Olympic literature and examples are drawn from previous summer and winter Games. This preliminary exploration is followed by the identification of some key challenges to be overcome if the opportunities available to a wide and diverse range of stakeholders are to be fully optimized. The article suggests that the 2012 Games can act as a catalyst for sports development throughout Britain, while also assisting with government cross-cutting agendas such as tackling crime, antisocial behaviour, developing healthy and active communities, improving educational attainment, and combating barriers to participation. In doing so, this article argues that priority should be placed at supporting grassroots sport through greater access to sport in the community, and not solely elite level sports development. The article concludes by suggesting that the 2012 Games provide opportunities to deliver real and tangible changes and most importantly, to afford a higher priority to sport, along with the obvious associated health benefits for Britain as a whole. The underlying challenge as we move towards 2012 is to achieve a positive step change in the attitudes towards sport and physical activity in British society. Achieving this would possibly be the greatest legacy of the 2012 Olympic and

  5. Observational constraints on unified dark matter including Hubble parameter data

    OpenAIRE

    Liao, Kai; Cao, Shuo; Wang, Jun; Gong, Xiaolong; Zhu, Zong-Hong

    2012-01-01

    We constrain a unified dark matter (UDM) model from the latest observational data. This model assumes that the dark sector is degenerate. Dark energy and dark matter are the same component. It can be described by an affine equation of state $P_X= p_0 +\\alpha \\rho_X$. Our data set contains the newly revised $H(z)$ data, type Ia supernovae (SNe Ia) from Union2 set, baryonic acoustic oscillation (BAO) observation from the spectroscopic Sloan Digital Sky Survey (SDSS) data release 7 (DR7) galaxy ...

  6. Dark matter: the astrophysical case

    International Nuclear Information System (INIS)

    Silk, J.

    2012-01-01

    The identification of dark matter is one of the most urgent problems in cosmology. I describe the astrophysical case for dark matter, from both an observational and a theoretical perspective. This overview will therefore focus on the observational motivations rather than the particle physics aspects of dark matter constraints on specific dark matter candidates. First, however, I summarize the astronomical evidence for dark matter, then I highlight the weaknesses of the standard cold dark matter model (LCDM) to provide a robust explanation of some observations. The greatest weakness in the dark matter saga is that we have not yet identified the nature of dark matter itself

  7. Legacies of the uranium ore mining industry and their restoration. A survey of Africa, Asia and Australia; Hinterlassenschaften des Uranerzbergbaus und deren Sanierung. Ein Ueberblick ueber Afrika, Asien und Australien

    Energy Technology Data Exchange (ETDEWEB)

    Waggitt, P. [International Atomic Energy Agency (IAEA), Vienna (Austria). Waste and Environmental Safety Section; Lersow, M. [Deutsche Gesellschaft fuer Geotechnik (DGGT) e.V., Breitenbrunn/Erzgebirge (Germany). Arbeitskreis ' Tailings' ; Maerten, H. [UIT GmbH, Dresden (Germany); Heathgate Resources Pty. Ltd., Adelaide, SA (Australia); Quasar Resources Pty. Ltd., Adelaide, SA (Australia)

    2008-03-13

    Management of the environment in the uranium mining industry has an eventful history of more than 50 years. In addition to examples of successful restoration of mining and preparation sites in some countries there are also numerous cases, in which no or defective restoration left behind serious waste deposits. In the course of the renaissance of the uranium industry there is increasing interest in the rehabilitation of such waste sites. There is still an urgent requirement to eradicate the environmental effects of the old mining industry. Previous deposits could be of interest for renewed working under the present economic boundary conditions. Restoration as an integral part of the current and future uranium mining industry with the application of modern international safety standards is extremely important. The contribution provides a survey of restoration projects of the old mining industry in various parts of the world and shows how the International Atomic Energy Agency, the national supervisory and approval authorities as well as the mining companies collaborate closely at many sites on solution of the difficult problems. (orig.)

  8. Review on Dark Photon

    Directory of Open Access Journals (Sweden)

    Curciarello Francesca

    2016-01-01

    Full Text Available e+e− collider experiments at the intensity frontier are naturally suited to probe the existence of a force beyond the Standard Model between WIMPs, the most viable dark matter candidates. The mediator of this new force, known as dark photon, should be a new vector gauge boson very weakly coupled to the Standard Model photon. No significant signal has been observed so far. I will report on current limits set on the coupling factor ε2 between the photon and the dark photon by e+e− collider experiments.

  9. Dark Matter in ATLAS

    CERN Document Server

    Resconi, Silvia; The ATLAS collaboration

    2016-01-01

    Results of Dark Matter searches in mono-X analysis with the ATLAS experiment at the Large Hadron Collider are reported. The data were collected in proton–proton collisions at a centre-of-mass energy of 13 TeV and correspond to an integrated luminosity of 3.2 fb-1. A description of the main characteristics of each analysis and how the main backgrounds are estimated is shown. The observed data are in agreement with the expected Standard Model backgrounds for all analysis described. Exclusion limits are presented for Dark Matter models including pair production of dark matter candidates.

  10. Dark Matter in ATLAS

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00222441; The ATLAS collaboration

    2016-01-01

    An overview of Dark Matter searches with the ATLAS experiment at the Large Hadron Collider (LHC) is shown. Results of Mono-X analyses requiring large missing transverse momentum and a recoiling detectable physics object (X) are reported. The data were collected in proton-proton collisions at a centre-of-mass energy of 13 TeV. The observed data are in agreement with the expected Standard Model backgrounds for all analyses described. Exclusion limits are presented for Dark Matter models including pair production of Dark Matter candidates.

  11. Physical drivers of galaxies' cold-gas content: exploring environmental and evolutionary effects with Dark Sage

    Science.gov (United States)

    Stevens, Adam R. H.; Brown, Toby

    2017-10-01

    We combine the latest spectrally stacked data of 21-cm emission from the Arecibo Legacy Fast ALFA survey with an updated version of the Dark Sage semi-analytic model to investigate the relative contributions of secular and environmental astrophysical processes on shaping the H I fractions and quiescence of galaxies in the local Universe. We calibrate the model to match the observed mean H I fraction of all galaxies as a function of stellar mass. Without consideration of stellar feedback, disc instabilities and active galactic nuclei, we show how the slope and normalization of this relation would change significantly. We find Dark Sage can reproduce the relative impact that halo mass is observed to have on satellites' H I fractions and quiescent fraction. However, the model satellites are systematically gas-poor. We discuss how this could be affected by satellite-central cross-contamination from the group-finding algorithm applied to the observed galaxies, but that it is not the full story. From our results, we suggest the anticorrelation between satellites' H I fractions and host halo mass, seen at fixed stellar mass and fixed specific star formation rate, can be attributed almost entirely to ram-pressure stripping of cold gas. Meanwhile, stripping of hot gas from around the satellites drives the correlation of quiescent fraction with halo mass at fixed stellar mass. Further detail in the modelling of galaxy discs' centres is required to solidify this result, however. We contextualize our results with those from other semi-analytic models and hydrodynamic simulations.

  12. Relieving the tension between weak lensing and cosmic microwave background with interacting dark matter and dark energy models

    Science.gov (United States)

    An, Rui; Feng, Chang; Wang, Bin

    2018-02-01

    We constrain interacting dark matter and dark energy (IDMDE) models using a 450-degree-square cosmic shear data from the Kilo Degree Survey (KiDS) and the angular power spectra from Planck's latest cosmic microwave background measurements. We revisit the discordance problem in the standard Lambda cold dark matter (ΛCDM) model between weak lensing and Planck datasets and extend the discussion by introducing interacting dark sectors. The IDMDE models are found to be able to alleviate the discordance between KiDS and Planck as previously inferred from the ΛCDM model, and moderately favored by a combination of the two datasets.

  13. Dark matter and dark energy solutions using by observational evidence

    Science.gov (United States)

    Demirel, E. C. Gunay; Yilmaz, I.

    2018-02-01

    In this study, we examine dark energy, dark matter and baryonic matter in FRW by observational evidences. Also we study our model by considering possible dark energy candidates such as Phantom energy. Obtained solutions show that dark energy candidate may be phantom energy depending on accuracy of today's observation.

  14. Cold dark matter plus not-so-clumpy dark relics

    NARCIS (Netherlands)

    Diamanti, R.; Ando, S.; Gariazzo, S.; Mena, O.; Weniger, C.

    Various particle physics models suggest that, besides the (nearly) cold dark matter that accounts for current observations, additional but sub-dominant dark relics might exist. These could be warm, hot, or even contribute as dark radiation. We present here a comprehensive study of two-component dark

  15. Verification and the safeguards legacy

    International Nuclear Information System (INIS)

    Perricos, Demetrius

    2001-01-01

    of Iraq was a case of late detection of undeclared activities, the case of DPRK was a case of prompt detection of discrepancies in the initial declaration through implementation of modem detection techniques, such as environmental sampling, and access to information. Access to the Security Council became important in view of the protracted process of non-compliance. The Model Additional Protocol (INFCIRC 540) agreed in 1997 incorporates the results of the efforts to strengthen the safeguards system and as such provides the possibility for more transparency by the States and more access to locations by the inspectors on the basis of information. It does not provide the broad and intrusive access rights as in the case of Iraq, since such rights are unprecedented and the result of a cease-fire arrangement involving the Security Council. But the expectations are that the broad implementation of the Additional Protocol will result in an effective and efficient safeguards verification system for the future. The on-site verification systems on a national, regional or multinational basis that have been put into operation in the past or are being discussed by States for the implementation of disarmament and non-proliferation conventions related to weapons of mass destruction whether nuclear, chemical or biological, have benefited and will benefit in the future from the guiding experience - both from the strengths and weaknesses -of the IAEA verification system. This is hopefully a legacy for the future of verification

  16. The Interactive Urban Model: Histories and Legacies Related to Prototyping the Twenty-First Century City

    OpenAIRE

    Verebes, Tom

    2016-01-01

    This article surveys the theoretical and historical legacies of mass production and standardization, and the cultural issues associated with globalization, in the most prolific era ever of urbanization. Situated at the intersection of scholarly writing on history, current conditions, and a speculative future, this article focuses on themes related to design research on computation, fabrication, and the city. Given the ongoing transition of industrial paradigm from Modernism’s dependency upon ...

  17. Dark Matter and Dark Energy Summary and Future Directions

    CERN Document Server

    Ellis, Jonathan Richard

    2003-01-01

    This paper reviews the progress reported at this Royal Society Discussion Meeting and advertizes some possible future directions in our drive to understand dark matter and dark energy. Additionally, a first attempt is made to place in context the exciting new results from the WMAP satellite, which were published shortly after this Meeting. In the first part of this review, pieces of observational evidence shown here that bear on the amounts of dark matter and dark energy are reviewed. Subsequently, particle candidates for dark matter are mentioned, and detection strategies are discussed. Finally, ideas are presented for calculating the amounts of dark matter and dark energy, and possibly relating them to laboratory data.

  18. Inelastic dark matter

    International Nuclear Information System (INIS)

    Smith, David; Weiner, Neal

    2001-01-01

    Many observations suggest that much of the matter of the universe is nonbaryonic. Recently, the DAMA NaI dark matter direct detection experiment reported an annual modulation in their event rate consistent with a WIMP relic. However, the Cryogenic Dark Matter Search (CDMS) Ge experiment excludes most of the region preferred by DAMA. We demonstrate that if the dark matter can only scatter by making a transition to a slightly heavier state (Δm∼100 keV), the experiments are no longer in conflict. Moreover, differences in the energy spectrum of nuclear recoil events could distinguish such a scenario from the standard WIMP scenario. Finally, we discuss the sneutrino as a candidate for inelastic dark matter in supersymmetric theories

  19. Xenophobic dark matter

    Science.gov (United States)

    Feng, Jonathan L.; Kumar, Jason; Sanford, David

    2013-07-01

    We consider models of xenophobic dark matter, in which isospin-violating dark matter-nucleon interactions significantly degrade the response of xenon direct detection experiments. For models of near-maximal xenophobia, with neutron-to-proton coupling ratio fn/fp≈-0.64, and dark matter mass near 8 GeV, the regions of interest for CoGeNT and CDMS-Si and the region of interest identified by Collar and Fields in CDMS-Ge data can be brought into agreement. This model may be tested in future direct, indirect, and collider searches. Interestingly, because the natural isotope abundance of xenon implies that xenophobia has its limits, we find that this xenophobic model may be probed in the near future by xenon experiments. Near-future data from the LHC and Fermi-LAT may also provide interesting alternative probes of xenophobic dark matter.

  20. Dark matter warms up

    CERN Multimedia

    Peplow, Mark

    2006-01-01

    "Unseen mass looks to be more "tepid" than thought. Astronomers have measured the temperature of dark matter for the first time. The discovery should help particle hunters to identify exactly what this mysterious substance is made of" (1 page)

  1. Cleaning up dark matter

    CERN Multimedia

    Bignami, Giovanni Fabrizio

    2006-01-01

    "An experiment in Italy has found tantalizing but puzzling evidence for axions, one if the leading candidates for dark matter. The authors explain how a pair of spinning neutron stars should settle the issue once and for all." (3 pages)

  2. Little composite dark matter.

    Science.gov (United States)

    Balkin, Reuven; Perez, Gilad; Weiler, Andreas

    2018-01-01

    We examine the dark matter phenomenology of a composite electroweak singlet state. This singlet belongs to the Goldstone sector of a well-motivated extension of the Littlest Higgs with T -parity. A viable parameter space, consistent with the observed dark matter relic abundance as well as with the various collider, electroweak precision and dark matter direct detection experimental constraints is found for this scenario. T -parity implies a rich LHC phenomenology, which forms an interesting interplay between conventional natural SUSY type of signals involving third generation quarks and missing energy, from stop-like particle production and decay, and composite Higgs type of signals involving third generation quarks associated with Higgs and electroweak gauge boson, from vector-like top-partners production and decay. The composite features of the dark matter phenomenology allows the composite singlet to produce the correct relic abundance while interacting weakly with the Higgs via the usual Higgs portal coupling [Formula: see text], thus evading direct detection.

  3. Inflatable Dark Matter.

    Science.gov (United States)

    Davoudiasl, Hooman; Hooper, Dan; McDermott, Samuel D

    2016-01-22

    We describe a general scenario, dubbed "inflatable dark matter," in which the density of dark matter particles can be reduced through a short period of late-time inflation in the early Universe. The overproduction of dark matter that is predicted within many, otherwise, well-motivated models of new physics can be elegantly remedied within this context. Thermal relics that would, otherwise, be disfavored can easily be accommodated within this class of scenarios, including dark matter candidates that are very heavy or very light. Furthermore, the nonthermal abundance of grand unified theory or Planck scale axions can be brought to acceptable levels without invoking anthropic tuning of initial conditions. A period of late-time inflation could have occurred over a wide range of scales from ∼MeV to the weak scale or above, and could have been triggered by physics within a hidden sector, with small but not necessarily negligible couplings to the standard model.

  4. Lectures on dark matter

    International Nuclear Information System (INIS)

    Seljak, U.

    2001-01-01

    These lectures concentrate on evolution and generation of dark matter perturbations. The purpose of the lectures is to present, in a systematic way, a comprehensive review of the cosmological parameters that can lead to observable effects in the dark matter clustering properties. We begin by reviewing the relativistic linear perturbation theory formalism. We discuss the gauge issue and derive Einstein's and continuity equations for several popular gauge choices. We continue by developing fluid equations for cold dark matter and baryons and Boltzmann equations for photons, massive and massless neutrinos. We then discuss the generation of initial perturbations by the process of inflation and the parameters of that process that can be extracted from the observations. Finally we discuss evolution of perturbations in various regimes and the imprint of the evolution on the dark matter power spectrum both in the linear and in the nonlinear regime. (author)

  5. The Dark Universe

    Science.gov (United States)

    Livio, Mario

    2010-04-01

    1. A brief history of dark matter Vera Rubin; 2. Microlensing towards the Magellanic Clouds Kailash Sahu; 3. Searching for galactic dark matter Harvey Richer; 4. Hot gas in clusters of galaxies and Omega Megan Donahue; 5. Tracking the Baryon density from the Big Bang to the present Gary Steigman; 6. Modified Newtonian dynamics and its implications Bob Sanders; 7. Cosmological parameters and quintessence from radio galaxies Ruth Daly and Eric Guerra; 8. The mass density of the Universe Neta Bahcall; 9. Growth of structure in the Universe John Peacock; 10. Cosmological implications of the most distant supernova (known) Adam Riess; 11. Dynamical probes of the Halo mass function Chris Kochanek; 12. Detection of gravitational waves from inflation Marc Kamionkowski and Andrew Jaffe; 13. Cosmological constant problems and their solution Alex Vilenkin; 14. Dark Matter and dark energy: a physicist's perspective Michael Dine.

  6. Issues Associated with Tritium Legacy Materials

    International Nuclear Information System (INIS)

    Mills, Michael

    2008-01-01

    This paper highlights some of the issues associated with the treatment of legacy materials linked to research into tritium over many years and also of materials used to contain or store tritium. The aim of the work is to recover tritium where practicable, and to leave the residual materials passively safe, either for disposal or for continued storage. A number of materials are currently stored at AWE which either contain tritium or have been used in tritium processing. It is essential that these materials are characterised such that a strategy may be developed for their safe stewardship, and ultimately for their treatment and disposal. Treatment processes for such materials are determined by the application of best practicable means (BPM) studies in accordance with the requirements of the Environment Agency of England and Wales. Clearly, it is necessary to understand the objectives of legacy material treatment / processing and the technical options available before a definitive BPM study is implemented. The majority of tritium legacy materials with which we are concerned originate from the decommissioning of a facility that was operational from the late 1950's through to the late 1990's when, on post-operative clear-out (POCO), the entire removable and transportable tritium inventory was moved to new, purpose built facilities. One of the principle tasks to be undertaken in the new facilities is the treatment of the legacy materials to recover tritium wherever practicable, and render the residual materials passively safe for disposal or continued storage. Where tritium recovery was not reasonably or technically feasible, then a means to assure continued safe storage was to be devised and implemented. The legacy materials are in the following forms: - Uranium beds which may or may not contain adsorbed tritium gas; - Tritium gas stored in containers; - Tritide targets for neutron generation; - Tritides of a broad spectrum of metals manufactured for research / long

  7. Gravity's dark side: Doing without dark matte

    International Nuclear Information System (INIS)

    Chalmers, M.

    2006-01-01

    Despite decades of searching, the 'dark matter' thought to hold galaxies together is still nowhere to be found. Matthew Chalmers describes how some physicists think it makes more sense to change our theory of gravity instead. Einstein's general theory of relativity is part of the bedrock of modern physics. It describes in elegant mathematical terms how matter causes space-time to curve, and therefore how objects move in a gravitational field. Since it was published in 1916, general relativity has passed every test asked of it with flying colours, and to many physicists the notion that it is wrong is sacrilege. But the motivation for developing an alternative theory of gravity is compelling. Over the last few years cosmologists have arrived at a simple yet extraordinarily successful model of universe. The trouble is that it requires most of the cosmos to be filled with mysterious stuff that we cannot see. In particular, general relativity - or rather its non-relativistic limit otherwise known as Newtonian gravity - can only correctly describe the dynamics of galaxies if we invoke huge quantities of 'dark matter'. Furthermore, an exotic entity called dark energy is necessary to account for the recent discovery that the expansion of the universe is accelerating. Indeed, in the standard model of cosmology, visible matter such as stars, planets and physics textbooks accounts for just 4% of the total universe. (U.K.)

  8. Distribution of Amphipods (Gammarus nipponensis Ueno) Among Mountain Headwater Streams with Different Legacies of Debris Flow Occurrence

    Science.gov (United States)

    To understand the impacts of debris flows on the distribution of an amphipod with limited dispersal ability in the context of stream networks, we surveyed the presence of Gammarus nipponensis in 87 headwater streams with different legacies of debris flow occurrence within an 8.5-...

  9. DESTINY, The Dark Energy Space Telescope

    Science.gov (United States)

    Pasquale, Bert A.; Woodruff, Robert A.; Benford, Dominic J.; Lauer, Tod

    2007-01-01

    We have proposed the development of a low-cost space telescope, Destiny, as a concept for the NASA/DOE Joint Dark Energy Mission. Destiny is a 1.65m space telescope, featuring a near-infrared (0.85-1.7m) survey camera/spectrometer with a moderate flat-field field of view (FOV). Destiny will probe the properties of dark energy by obtaining a Hubble diagram based on Type Ia supernovae and a large-scale mass power spectrum derived from weak lensing distortions of field galaxies as a function of redshift.

  10. Dark matter universe

    Science.gov (United States)

    Bahcall, Neta A.

    2015-01-01

    Most of the mass in the universe is in the form of dark matter—a new type of nonbaryonic particle not yet detected in the laboratory or in other detection experiments. The evidence for the existence of dark matter through its gravitational impact is clear in astronomical observations—from the early observations of the large motions of galaxies in clusters and the motions of stars and gas in galaxies, to observations of the large-scale structure in the universe, gravitational lensing, and the cosmic microwave background. The extensive data consistently show the dominance of dark matter and quantify its amount and distribution, assuming general relativity is valid. The data inform us that the dark matter is nonbaryonic, is “cold” (i.e., moves nonrelativistically in the early universe), and interacts only weakly with matter other than by gravity. The current Lambda cold dark matter cosmology—a simple (but strange) flat cold dark matter model dominated by a cosmological constant Lambda, with only six basic parameters (including the density of matter and of baryons, the initial mass fluctuations amplitude and its scale dependence, and the age of the universe and of the first stars)—fits remarkably well all the accumulated data. However, what is the dark matter? This is one of the most fundamental open questions in cosmology and particle physics. Its existence requires an extension of our current understanding of particle physics or otherwise point to a modification of gravity on cosmological scales. The exploration and ultimate detection of dark matter are led by experiments for direct and indirect detection of this yet mysterious particle. PMID:26417091

  11. Dark matter universe.

    Science.gov (United States)

    Bahcall, Neta A

    2015-10-06

    Most of the mass in the universe is in the form of dark matter--a new type of nonbaryonic particle not yet detected in the laboratory or in other detection experiments. The evidence for the existence of dark matter through its gravitational impact is clear in astronomical observations--from the early observations of the large motions of galaxies in clusters and the motions of stars and gas in galaxies, to observations of the large-scale structure in the universe, gravitational lensing, and the cosmic microwave background. The extensive data consistently show the dominance of dark matter and quantify its amount and distribution, assuming general relativity is valid. The data inform us that the dark matter is nonbaryonic, is "cold" (i.e., moves nonrelativistically in the early universe), and interacts only weakly with matter other than by gravity. The current Lambda cold dark matter cosmology--a simple (but strange) flat cold dark matter model dominated by a cosmological constant Lambda, with only six basic parameters (including the density of matter and of baryons, the initial mass fluctuations amplitude and its scale dependence, and the age of the universe and of the first stars)--fits remarkably well all the accumulated data. However, what is the dark matter? This is one of the most fundamental open questions in cosmology and particle physics. Its existence requires an extension of our current understanding of particle physics or otherwise point to a modification of gravity on cosmological scales. The exploration and ultimate detection of dark matter are led by experiments for direct and indirect detection of this yet mysterious particle.

  12. Constraints on the dark matter and dark energy interactions from weak lensing bispectrum tomography

    Energy Technology Data Exchange (ETDEWEB)

    An, Rui [School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Feng, Chang [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Wang, Bin, E-mail: an_rui@sjtu.edu.cn, E-mail: chang.feng@uci.edu, E-mail: wang_b@sjtu.edu.cn [Center for Gravitation and Cosmology, College of Physical Science and Technology, Yangzhou University, Yangzhou 225009 (China)

    2017-10-01

    We estimate uncertainties of cosmological parameters for phenomenological interacting dark energy models using weak lensing convergence power spectrum and bispectrum. We focus on the bispectrum tomography and examine how well the weak lensing bispectrum with tomography can constrain the interactions between dark sectors, as well as other cosmological parameters. Employing the Fisher matrix analysis, we forecast parameter uncertainties derived from weak lensing bispectra with a two-bin tomography and place upper bounds on strength of the interactions between the dark sectors. The cosmic shear will be measured from upcoming weak lensing surveys with high sensitivity, thus it enables us to use the higher order correlation functions of weak lensing to constrain the interaction between dark sectors and will potentially provide more stringent results with other observations combined.

  13. Dark matter: Theoretical perspectives

    International Nuclear Information System (INIS)

    Turner, M.S.

    1993-01-01

    The author both reviews and makes the case for the current theoretical prejudice: a flat Universe whose dominant constituent is nonbaryonic dark matter, emphasizing that this is still a prejudice and not yet fact. The theoretical motivation for nonbaryonic dark matter is discussed in the context of current elementary-particle theory, stressing that (i) there are no dark-matter candidates within the open-quotes standard modelclose quotes of particle physics, (ii) there are several compelling candidates within attractive extensions of the standard model of particle physics, and (iii) the motivation for these compelling candidates comes first and foremost from particle physics. The dark-matter problem is now a pressing issue in both cosmology and particle physics, and the detection of particle dark matter would provide evidence for open-quotes new physics.close quotes The compelling candidates are a very light axion (10 -6 --10 -4 eV), a light neutrino (20--90 eV), and a heavy neutralino (10 GeV--2 TeV). The production of these particles in the early Universe and the prospects for their detection are also discussed. The author briefly mentions more exotic possibilities for the dark matter, including a nonzero cosmological constant, superheavy magnetic monopoles, and decaying neutrinos. 119 refs

  14. Dark matter: Theoretical perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Turner, M.S. (Chicago Univ., IL (United States). Enrico Fermi Inst. Fermi National Accelerator Lab., Batavia, IL (United States))

    1993-01-01

    I both review and make the case for the current theoretical prejudice: a flat Universe whose dominant constituent is nonbaryonic dark matter, emphasizing that this is still a prejudice and not yet fact. The theoretical motivation for nonbaryonic dark matter is discussed in the context of current elementary-particle theory, stressing that: (1) there are no dark matter candidates within the standard model of particle physics; (2) there are several compelling candidates within attractive extensions of the standard model of particle physics; and (3) the motivation for these compelling candidates comes first and foremost from particle physics. The dark-matter problem is now a pressing issue in both cosmology and particle physics, and the detection of particle dark matter would provide evidence for new physics.'' The compelling candidates are: a very light axion ( 10[sup [minus]6] eV--10[sup [minus]4] eV); a light neutrino (20 eV--90 eV); and a heavy neutralino (10 GeV--2 TeV). The production of these particles in the early Universe and the prospects for their detection are also discussed. I briefly mention more exotic possibilities for the dark matter, including a nonzero cosmological constant, superheavy magnetic monopoles, and decaying neutrinos.

  15. Dark matter: Theoretical perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Turner, M.S. [Chicago Univ., IL (United States). Enrico Fermi Inst.]|[Fermi National Accelerator Lab., Batavia, IL (United States)

    1993-01-01

    I both review and make the case for the current theoretical prejudice: a flat Universe whose dominant constituent is nonbaryonic dark matter, emphasizing that this is still a prejudice and not yet fact. The theoretical motivation for nonbaryonic dark matter is discussed in the context of current elementary-particle theory, stressing that: (1) there are no dark matter candidates within the standard model of particle physics; (2) there are several compelling candidates within attractive extensions of the standard model of particle physics; and (3) the motivation for these compelling candidates comes first and foremost from particle physics. The dark-matter problem is now a pressing issue in both cosmology and particle physics, and the detection of particle dark matter would provide evidence for ``new physics.`` The compelling candidates are: a very light axion ( 10{sup {minus}6} eV--10{sup {minus}4} eV); a light neutrino (20 eV--90 eV); and a heavy neutralino (10 GeV--2 TeV). The production of these particles in the early Universe and the prospects for their detection are also discussed. I briefly mention more exotic possibilities for the dark matter, including a nonzero cosmological constant, superheavy magnetic monopoles, and decaying neutrinos.

  16. The ATLAS Trigger Simulation with Legacy Software

    CERN Document Server

    Bernius, Catrin; The ATLAS collaboration

    2017-01-01

    Physics analyses at the LHC require accurate simulations of the detector response and the event selection processes, generally done with the most recent software releases. The trigger response simulation is crucial for determination of overall selection efficiencies and signal sensitivities and should be done with the same software release with which data were recorded. This requires potentially running with software dating many years back, the so-called legacy software. Therefore having a strategy for running legacy software in a modern environment becomes essential when data simulated for past years start to present a sizeable fraction of the total. The requirements and possibilities for such a simulation scheme within the ATLAS software framework were examined and a proof-of-concept simulation chain has been successfully implemented. One of the greatest challenges was the choice of a data format which promises long term compatibility with old and new software releases. Over the time periods envisaged, data...

  17. The ATLAS Trigger Simulation with Legacy Software

    CERN Document Server

    Bernius, Catrin; The ATLAS collaboration

    2017-01-01

    Physics analyses at the LHC which search for rare physics processes or measure Standard Model parameters with high precision require accurate simulations of the detector response and the event selection processes. The accurate simulation of the trigger response is crucial for determination of overall selection efficiencies and signal sensitivities. For the generation and the reconstruction of simulated event data, generally the most recent software releases are used to ensure the best agreement between simulated data and real data. For the simulation of the trigger selection process, however, the same software release with which real data were taken should be ideally used. This requires potentially running with software dating many years back, the so-called legacy software. Therefore having a strategy for running legacy software in a modern environment becomes essential when data simulated for past years start to present a sizeable fraction of the total. The requirements and possibilities for such a simulatio...

  18. Disaggregation of legacy soil data using area to point kriging for mapping soil organic carbon at the regional scale.

    Science.gov (United States)

    Kerry, Ruth; Goovaerts, Pierre; Rawlins, Barry G; Marchant, Ben P

    2012-01-15

    Legacy data in the form of soil maps, which often have typical property measurements associated with each polygon, can be an important source of information for digital soil mapping (DSM). Methods of disaggregating such information and using it for quantitative estimation of soil properties by methods such as regression kriging (RK) are needed. Several disaggregation processes have been investigated; preferred methods include those which include consideration of scorpan factors and those which are mass preserving (pycnophylactic) making transitions between different scales of investigation more theoretically sound. Area to point kriging (AtoP kriging) is pycnophylactic and here we investigate its merits for disaggregating legacy data from soil polygon maps. Area to point regression kriging (AtoP RK) which incorporates ancillary data into the disaggre-gation process was also applied. The AtoP kriging and AtoP RK approaches do not involve collection of new soil measurements and are compared with disaggregation by simple rasterization. Of the disaggregation methods investigated, AtoP RK gave the most accurate predictions of soil organic carbon (SOC) concentrations (smaller mean absolute errors (MAEs) of cross-validation) for disaggregation of soil polygon data across the whole of Northern Ireland. Legacy soil polygon data disaggregated by AtoP kriging and simple rasterization were used in a RK framework for estimating soil organic carbon (SOC) concentrations across the whole of Northern Ireland, using soil sample data from the Tellus survey of Northern Ireland and with other covariates (altitude and airborne radiometric potassium). This allowed direct comparison with previous analysis of the Tellus survey data. Incorporating the legacy data, whether from simple rasterization of the polygons or AtoP kriging, substantially reduced the MAEs of RK compared with previous analyses of the Tellus data. However, using legacy data disaggregated by AtoP kriging in RK resulted in

  19. Olympics Legacy: the London Olympics 2012

    OpenAIRE

    Gulsen, Guler; Holden, Robert

    2010-01-01

    The reasons for proposing a London 2012 bid are outlined in the light of London city planning over the past sixty years. The processes influencing the bid for the London 2012 Olympics are investigated in respect of the lessons from Barcelona and Sydney. The role of environmental\\ud and landscape improvement is examined and the importance of legacy is described and analysed. The cost of Olympiads since Sydney 2000 are described and compared. Then progress of the London 2012 Olympics developmen...

  20. The mycological legacy of Elias Magnus Fries

    OpenAIRE

    Petersen, Ronald H.; Knudsen, Henning

    2015-01-01

    The taxonomic concepts which originated with or were accepted by Elias Magnus Fries were presented during his lifetime in the printed word, illustrative depiction, and in collections of dried specimens. This body of work was welcomed by the mycological and botanical communities of his time: students and associates aided Fries and after his passing carried forward his taxonomic ideas. His legacy spawned a line of Swedish and Danish mycologists intent on perpetuating the Fries tradition: Hampus...

  1. Requalification of Legacy Radioactive Waste in Germany

    International Nuclear Information System (INIS)

    Bandt, Gabriele; Hoffmann, Paulina; Spicher, Gottfried; Filss, Martin; Schauer, Claudia

    2016-01-01

    Conclusion: • Large stocks of legacy radioactive waste exist, which do not comply with the requirements of the Konrad repository. • Requalification campaigns with thousands of waste packages have successfully been carried out. • Quality assurance plans contain all necessary steps of specific (requalification) campaigns and optimize the procedures for each campaign in advance. • When sophisticated measurement equipment was needed an iterative procedure was adopted. Repeated evaluations of the nondestructive res. destructive measurements limited the measures to the necessary limit.

  2. Migration Performance for Legacy Data Access

    Directory of Open Access Journals (Sweden)

    Kam Woods

    2008-12-01

    Full Text Available We present performance data relating to the use of migration in a system we are creating to provide web access to heterogeneous document collections in legacy formats. Our goal is to enable sustained access to collections such as these when faced with increasing obsolescence of the necessary supporting applications and operating systems. Our system allows searching and browsing of the original files within their original contexts utilizing binary images of the original media. The system uses static and dynamic file migration to enhance collection browsing, and emulation to support both the use of legacy programs to access data and long-term preservation of the migration software. While we provide an overview of the architectural issues in building such a system, the focus of this paper is an in-depth analysis of file migration using data gathered from testing our software on 1,885 CD-ROMs and DVDs. These media are among the thousands of collections of social and scientific data distributed by the United States Government Printing Office (GPO on legacy media (CD-ROM, DVD, floppy disk under the Federal Depository Library Program (FDLP over the past 20 years.

  3. A legacy building model for holistic nursing.

    Science.gov (United States)

    Lange, Bernadette; Zahourek, Rothlyn P; Mariano, Carla

    2014-06-01

    This pilot project was an effort to record the historical roots, development, and legacy of holistic nursing through the visionary spirit of four older American Holistic Nurses Association (AHNA) members. The aim was twofold: (a) to capture the holistic nursing career experiences of elder AHNA members and (b) to begin to create a Legacy Building Model for Holistic Nursing. The narratives will help initiate an ongoing, systematic method for the collection of historical data and serve as a perpetual archive of knowledge and inspiration for present and future holistic nurses. An aesthetic inquiry approach was used to conduct in-depth interviews with four older AHNA members who have made significant contributions to holistic nursing. The narratives provide a rich description of their personal and professional evolution as holistic nurses. The narratives are presented in an aesthetic format of the art forms of snapshot, pastiche, and collage rather than traditional presentations of research findings. A synopsis of the narratives is a dialogue between the three authors and provides insight for how a Legacy Model can guide our future. Considerations for practice, education, and research are discussed based on the words of wisdom from the four older holistic nurses.

  4. The Political Legacy of School Accountability Systems

    Directory of Open Access Journals (Sweden)

    Sherman Dorn

    1998-01-01

    Full Text Available The recent battle reported from Washington about proposed national testing program does not tell the most important political story about high stakes tests. Politically popular school accountability systems in many states already revolve around statistical results of testing with high-stakes environments. The future of high stakes tests thus does not depend on what happens on Capitol Hill. Rather, the existence of tests depends largely on the political culture of published test results. Most critics of high-stakes testing do not talk about that culture, however. They typically focus on the practice legacy of testing, the ways in which testing creates perverse incentives against good teaching. More important may be the political legacy, or how testing defines legitimate discussion about school politics. The consequence of statistical accountability systems will be the narrowing of purpose for schools, impatience with reform, and the continuing erosion of political support for publicly funded schools. Dissent from the high-stakes accountability regime that has developed around standardized testing, including proposals for professionalism and performance assessment, commonly fails to consider these political legacies. Alternatives to standardized testing which do not also connect schooling with the public at large will not be politically viable.

  5. Probes for Dark Matter Physics

    OpenAIRE

    Khlopov, Maxim Yu.

    2018-01-01

    The existence of cosmological dark matter is in the bedrock of the modern cosmology. The dark matter is assumed to be nonbaryonic and to consist of new stable particles. However if composite dark matter contains stable electrically charged leptons and quarks bound by ordinary Coulomb interaction in elusive dark atoms, these charged constituents of dark atoms can be the subject of direct experimental test at the colliders. In such models the excessive negatively double charged particles are bo...

  6. Legacy sample disposition project. Volume 2: Final report

    International Nuclear Information System (INIS)

    Gurley, R.N.; Shifty, K.L.

    1998-02-01

    This report describes the legacy sample disposition project at the Idaho Engineering and Environmental Laboratory (INEEL), which assessed Site-wide facilities/areas to locate legacy samples and owner organizations and then characterized and dispositioned these samples. This project resulted from an Idaho Department of Environmental Quality inspection of selected areas of the INEEL in January 1996, which identified some samples at the Test Reactor Area and Idaho Chemical Processing Plant that had not been characterized and dispositioned according to Resource Conservation and Recovery Act (RCRA) requirements. The objective of the project was to manage legacy samples in accordance with all applicable environmental and safety requirements. A systems engineering approach was used throughout the project, which included collecting the legacy sample information and developing a system for amending and retrieving the information. All legacy samples were dispositioned by the end of 1997. Closure of the legacy sample issue was achieved through these actions

  7. The DECam minute cadence survey - I

    Science.gov (United States)

    Belardi, Claudia; Kilic, Mukremin; Munn, Jeffrey A.; Gianninas, A.; Barber, Sara D.; Dey, Arjun; Stetson, Peter B.

    2016-11-01

    We present the first results from a minute cadence survey of a 3 deg2 field obtained with the Dark Energy Camera. We imaged part of the Canada-France-Hawaii Telescope Legacy Survey area over eight half-nights. We use the stacked images to identify 111 high proper motion white dwarf candidates with g ≤ 24.5 mag and search for eclipse-like events and other sources of variability. We find a new g = 20.64 mag pulsating ZZ Ceti star with pulsation periods of 11-13 min. However, we do not find any transiting planetary companions in the habitable zone of our target white dwarfs. Given the probability of eclipses of 1 per cent and our observing window from the ground, the non-detection of such companions in this first field is not surprising. Minute cadence DECam observations of additional fields will provide stringent constraints on the frequency of planets in the white dwarf habitable zone.

  8. Oleg Grabar: the scholarly legacy

    Directory of Open Access Journals (Sweden)

    Robert Hillenbrand

    2012-06-01

    Full Text Available After surveying the various necrologies and events celebrating the life and achievements of Oleg Grabar, the article reflects in a general sense on why his death has unleashed such a flood of memories, using Grabar’s own assessment of his work as a tool. The paper then underlines his extraordinary range and attempts to identify his special skills: his intellectual curiosity that drove him to pose questions rather than dictate answers; his openness to new theoretical and technological ideas and techniques; and his habit of thinking outside the box, a skill he made very much his own and that he did not learn from his teachers. His lack of professional jealousy and of the deformities that attend over-specialization were alike noteworthy. The paper then discusses his books in detail, especially The Formation of Islamic Art and The Mediation of Ornament, his acknowledged masterpieces which had wide circulation within the field and outside it. Finally, the paper anthologizes the comments of his students and colleagues on this remarkable and lovable man.

  9. Working the Dark Side

    DEFF Research Database (Denmark)

    Bjering, Jens Christian Borrebye

    A few days after the terror attacks of 9/11, then Vice President Dick Cheney appeared on television with a call for “working the dark side.” While still unclear what this expression entailed at the time, Cheney's comment appears in retrospect to almost have been prophetic for the years to come...... – years where parts of the U.S. Army and intelligence community set up a rampant torture regime all across the world. Yet, the connection between a so-called “dark side,” “working” this “dark side,” and the torture that followed is not a given, but, instead, a consequence of a set of very specific legal......, political, and personal choices in the early years after 9/11. This dissertation is an investigation into how the notion of a “dark side” took form, and of how and why the specific make-up of this“dark side” ended up creating a torture regime which already today seems almost unreal. The dissertation's first...

  10. Dark matter detection - II

    International Nuclear Information System (INIS)

    Zacek, Viktor

    2015-01-01

    The quest for the mysterious missing mass of the universe has become one of the big challenges of today's particle physics and cosmology. Astronomical observations show that only 1% of the matter of the universe is luminous. Moreover there is now convincing evidence that 85% of all gravitationally observable matter in the universe is of a new exotic kind, different from the 'ordinary' matter surrounding us. In a series of three lectures we discuss past, recent and future efforts made world-wide to detect and/or decipher the nature of Dark Matter. In Lecture I we review our present knowledge of the Dark Matter content of the Universe and how experimenters search for it's candidates; In Lecture II we discuss so-called 'direct detection' techniques which allow to search for scattering of galactic dark matter particles with detectors in deep-underground laboratories; we discuss the interpretation of experimental results and the challenges posed by different backgrounds; In Lecture III we take a look at the 'indirect detection' of the annihilation of dark matter candidates in astrophysical objects, such as our sun or the center of the Milky Way; In addition we will have a look at efforts to produce Dark Matter particles directly at accelerators and we shall close with a look at alternative nonparticle searches and future prospects. (author)

  11. Dark matter detection - III

    International Nuclear Information System (INIS)

    Zacek, Viktor

    2015-01-01

    The quest for the missing mass of the universe has become one of the big challenges of todays particle physics and cosmology. Astronomical observations show that only 1% of the matter of the Universe is luminous. Moreover there is now convincing evidence that 85% of all gravitationally observable matter in the Universe is of a new exotic kind, different from the 'ordinary' matter surrounding us. In a series of three lectures we discuss past, recent and future efforts made world- wide to detect and/or decipher the nature of Dark Matter. In Lecture I we review our present knowledge of the Dark Matter content of the Universe and how experimenters search for it's candidates; In Lecture II we discuss so-called 'direct detection' techniques which allow to search for scattering of galactic dark matter particles with detectors in deep-underground laboratories; we discuss the interpretation of experimental results and the challenges posed by different backgrounds; In Lecture III we take a look at the 'indirect detection' of the annihilation of dark matter candidates in astrophysical objects, such as our sun or the center of the Milky Way; In addition we will have a look at efforts to produce Dark Matter particles directly at accelerators and we shall close with a look at alternative nonparticle searches and future prospects. (author)

  12. Dark matter detection - I

    International Nuclear Information System (INIS)

    Zacek, Viktor

    2015-01-01

    The quest for the mysterious missing mass of the universe has become one of the big challenges of today's particle physics and cosmology. Astronomical observations show that only 1% of the matter of the universe is luminous. Moreover there is now convincing evidence that 85% of all gravitationally observable matter in the universe is of a new exotic kind, different from the 'ordinary' matter surrounding us. In a series of three lectures we discuss past, recent and future efforts made world-wide to detect and/or decipher the nature of Dark Matter. In Lecture I we review our present knowledge of the Dark Matter content of the Universe and how experimenters search for it's candidates; In Lecture II we discuss so-called 'direct detection' techniques which allow to search for scattering of galactic dark matter particles with detectors in deep-underground laboratories; we discuss the interpretation of experimental results and the challenges posed by different backgrounds; In Lecture III we take a look at the 'indirect detection' of the annihilation of dark matter candidates in astrophysical objects, such as our sun or the center of the Milky Way; In addition we will have a look at efforts to produce Dark Matter particles directly at accelerators and we shall close with a look at alternative nonparticle searches and future prospects. (author)

  13. Revival of the unified dark energy-dark matter model?

    International Nuclear Information System (INIS)

    Bento, M.C.; Bertolami, O.; Sen, A.A.

    2004-01-01

    We consider the generalized Chaplygin gas (GCG) proposal for unification of dark energy and dark matter and show that it admits an unique decomposition into dark energy and dark matter components once phantomlike dark energy is excluded. Within this framework, we study structure formation and show that difficulties associated to unphysical oscillations or blowup in the matter power spectrum can be circumvented. Furthermore, we show that the dominance of dark energy is related to the time when energy density fluctuations start deviating from the linear δ∼a behavior

  14. Dark matter as a weakly coupled dark baryon

    Science.gov (United States)

    Mitridate, Andrea; Redi, Michele; Smirnov, Juri; Strumia, Alessandro

    2017-10-01

    Dark Matter might be an accidentally stable baryon of a new confining gauge interaction. We extend previous studies exploring the possibility that the DM is made of dark quarks heavier than the dark confinement scale. The resulting phenomenology contains new unusual elements: a two-stage DM cosmology (freeze-out followed by dark condensation), a large DM annihilation cross section through recombination of dark quarks (allowing to fit the positron excess). Light dark glue-balls are relatively long lived and give extra cosmological effects; DM itself can remain radioactive.

  15. Quantitative evaluation of legacy phosphorus and its spatial distribution.

    Science.gov (United States)

    Lou, Hezhen; Zhao, Changsen; Yang, Shengtian; Shi, Liuhua; Wang, Yue; Ren, Xiaoyu; Bai, Juan

    2018-04-01

    A phosphorus resource crisis threatens the security of global crop production, especially in developing countries like China and Brazil. Legacy phosphorus (legacy-P), which is left behind in agricultural soil by over-fertilization, can help address this issue as a new resource in the soil phosphorus pool. However, issues involved with calculating and defining the spatial distribution of legacy-P hinder its future utilization. To resolve these issues, this study applied remote sensing and ecohydrological modeling to precisely quantify legacy-P and define its spatial distribution in China's Sanjiang Plain from 2000 to 2014. The total legacy-P in the study area was calculated as 579,090 t with an annual average of 38,600 t; this comprises 51.83% of the phosphorus fertilizer applied annually. From 2000 to 2014, the annual amount of legacy-P increased by more than 3.42-fold, equivalent to a 2460-ton increase each year. The spatial distribution of legacy-P showed heterogeneity and agglomeration in this area, with peaks in cultivated land experiencing long-term agricultural development. This study supplies a new approach to finding legacy-P in soil as a precondition for future utilization. Once its spatial distribution is known, legacy-P can be better utilized in agriculture to help alleviate the phosphorus resource crisis. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Transforming Cobol Legacy Software to a Generic Imperative Model

    National Research Council Canada - National Science Library

    Moraes, DinaL

    1999-01-01

    .... This research develops a transformation system to convert COBOL code into a generic imperative model, recapturing the initial design and deciphering the requirements implemented by the legacy code...

  17. The darkness that shaped the void : Dark energy and cosmic voids

    NARCIS (Netherlands)

    Bos, E. G. Patrick; van de Weygaert, Rien; Dolag, Klaus; Pettorino, Valeria

    2012-01-01

    We assess the sensitivity of void shapes to the nature of dark energy that was pointed out in recent studies and also investigate whether or not void shapes are useable as an observational probe in galaxy redshift surveys. Our focus is on the evolution of the mean void ellipticity and its underlying

  18. Asymmetric Higgsino dark matter.

    Science.gov (United States)

    Blum, Kfir; Efrati, Aielet; Grossman, Yuval; Nir, Yosef; Riotto, Antonio

    2012-08-03

    In the supersymmetric framework, prior to the electroweak phase transition, the existence of a baryon asymmetry implies the existence of a Higgsino asymmetry. We investigate whether the Higgsino could be a viable asymmetric dark matter candidate. We find that this is indeed possible. Thus, supersymmetry can provide the observed dark matter abundance and, furthermore, relate it with the baryon asymmetry, in which case the puzzle of why the baryonic and dark matter mass densities are similar would be explained. To accomplish this task, two conditions are required. First, the gauginos, squarks, and sleptons must all be very heavy, such that the only electroweak-scale superpartners are the Higgsinos. With this spectrum, supersymmetry does not solve the fine-tuning problem. Second, the temperature of the electroweak phase transition must be low, in the (1-10) GeV range. This condition requires an extension of the minimal supersymmetric standard model.

  19. Dark Energy. What the ...?

    Energy Technology Data Exchange (ETDEWEB)

    Wechsler, Risa

    2007-10-30

    What is the Universe made of? This question has been asked as long as humans have been questioning, and astronomers and physicists are finally converging on an answer. The picture which has emerged from numerous complementary observations over the past decade is a surprising one: most of the matter in the Universe isn't visible, and most of the Universe isn't even made of matter. In this talk, I will explain what the rest of this stuff, known as 'Dark Energy' is, how it is related to the so-called 'Dark Matter', how it impacts the evolution of the Universe, and how we can study the dark universe using observations of light from current and future telescopes.

  20. Periodically modulated dark states

    Science.gov (United States)

    Han, Yingying; Zhang, Jun; Zhang, Wenxian

    2018-04-01

    Phenomena of electromagnetically induced transparency (PEIT) may be interpreted by the Autler-Townes Splitting (ATS), where the coupled states are split by the coupling laser field, or by the quantum destructive interference (QDI), where the atomic phases caused by the coupling laser and the probe laser field cancel. We propose modulated experiments to explore the PEIT in an alternative way by periodically modulating the coupling and the probe fields in a Λ-type three-level system initially in a dark state. Our analytical and numerical results rule out the ATS interpretation and show that the QDI interpretation is more appropriate for the modulated experiments. Interestingly, dark state persists in the double-modulation situation where control and probe fields never occur simultaneously, which is significant difference from the traditional dark state condition. The proposed experiments are readily implemented in atomic gases, artificial atoms in superconducting quantum devices, or three-level meta-atoms in meta-materials.

  1. Dark chocolate exacerbates acne.

    Science.gov (United States)

    Vongraviopap, Saivaree; Asawanonda, Pravit

    2016-05-01

    The effects of chocolate on acne exacerbations have recently been reevaluated. For so many years, it was thought that it had no role in worsening acne. To investigate whether 99% dark chocolate, when consumed in regular daily amounts, would cause acne to worsen in acne-prone male subjects, twenty-five acne prone male subjects were asked to consume 25 g of 99% dark chocolate daily for 4 weeks. Assessments which included Leeds revised acne scores as well as lesion counts took place weekly. Food frequency questionnaire was used, and daily activities were recorded. Statistically significant changes of acne scores and numbers of comedones and inflammatory papules were detected as early as 2 weeks into the study. At 4 weeks, the changes remained statistically significant compared to baseline. Dark chocolate when consumed in normal amounts for 4 weeks can exacerbate acne in male subjects with acne-prone skin. © 2015 The International Society of Dermatology.

  2. WISPy cold dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Arias, Paola [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Pontificia Univ. Catolica de Chile, Santiago (Chile). Facultad de Fisica; Cadamuro, Davide; Redondo, Javier [Max-Planck-Institut fuer Physik, Muenchen (Germany); Goodsell, Mark [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); European Organization for Nuclear Research (CERN), Geneva (Switzerland); Jaeckel, Joerg [Durham Univ. (United Kingdom). Inst. for Particle Physics Phenomenology; Ringwald, Andreas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2012-01-15

    Very weakly interacting slim particles (WISPs), such as axion-like particles (ALPs) or hidden photons (HPs), may be non-thermally produced via the misalignment mechanism in the early universe and survive as a cold dark matter population until today. We find that, both for ALPs and HPs whose dominant interactions with the standard model arise from couplings to photons, a huge region in the parameter spaces spanned by photon coupling and ALP or HP mass can give rise to the observed cold dark matter. Remarkably, a large region of this parameter space coincides with that predicted in well motivated models of fundamental physics. A wide range of experimental searches - exploiting haloscopes (direct dark matter searches exploiting microwave cavities), helioscopes (searches for solar ALPs or HPs), or light-shining-through-a-wall techniques - can probe large parts of this parameter space in the foreseeable future. (orig.)

  3. The Chandra COSMOS-Legacy Survey: The z>3 Sample

    Science.gov (United States)

    Marchesi, S.; Civano, F.; Salvato, M.; Shankar, F.; Comastri, A.; Elvis, M.; Lanzuisi, G.; Trakhtenbrot, B.; Vignali, C.; Zamorani, G.; Allevato, V.; Brusa, M.; Fiore, F.; Gilli, R.; Griffiths, R.; Hasinger, G.; Miyaji, T.; Schawinski, K.; Treister, E.; Urry, C. M.

    2016-08-01

    We present the largest high-redshift (3 0 at z > 3. We compute the number counts in the observed 0.5-2 keV band, finding a decline in the number of sources at z > 3 and constraining phenomenological models of the X-ray background. We compute the AGN space density at z > 3 in two different luminosity bins. At higher luminosities (logL(2-10 keV) > 44.1 erg s-1), the space density declines exponentially, dropping by a factor of ˜20 from z ˜ 3 to z ˜ 6. The observed decline is ˜80% steeper at lower luminosities (43.55 erg s-1 evolution dividing our sample into optically classified Type 1 and Type 2 AGNs. At logL(2-10 keV) > 44.1 erg s-1, unobscured and obscured objects may have different evolution with redshift, with the obscured component being three times higher at z ˜ 5. Finally, we compare our space density with predictions of quasar activation merger models, whose calibration is based on optically luminous AGNs. These models significantly overpredict the number of expected AGNs at logL (2-10 keV) > 44.1 erg s-1 with respect to our data.

  4. CALIFA, the Calar Alto Legacy Integral Field Area survey

    Czech Academy of Sciences Publication Activity Database

    Sánchez, Sebastián F.; Kennicutt, R.C.; Gil de Paz, A.; van de Ven, G.; Vílchez, J.M.; Wisotzki, L.; Walcher, C.J.; Mast, D.; Aguerri, J.A.L.; Albiol-Pérez, S.; Jungwiert, Bruno

    2012-01-01

    Roč. 538, February (2012), A8/1-A8/31 ISSN 0004-6361 R&D Projects: GA MŠk(CZ) LC06014; GA ČR GD205/08/H005 Institutional research plan: CEZ:AV0Z10030501 Keywords : spectroscopic techniques * active galaxies * evolution of galaxies Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 5.084, year: 2012

  5. The James Clerk Maxwell Telescope spectral legacy survey

    NARCIS (Netherlands)

    Plume, R.; Fuller, G. A.; Helmich, F.; van der Tak, F. F. S.; Roberts, H.; Bowey, J.; Buckle, J.; Butner, H.; Caux, E.; Ceccarelli, C.; van Dishoeck, E. F.; Friberg, P.; Gibb, A. G.; Hatchell, J.; Hogerheijde, M. R.; Matthews, H.; Millar, T. J.; Mitchell, G.; Moore, T. J. T.; Ossenkopf, V.; Rawlings, J. M. C.; Richer, J.; Roellig, M.; Schilke, P.; Spaans, M.; Tielens, A. G. G. M.; Thompson, M. A.; Viti, S.; Weferling, B.; White, Glenn J.; Wouterloot, J.; Yates, J.; Zhu, M.

    Stars form in the densest, coldest, most quiescent regions of molecular clouds. Molecules provide the only probes that can reveal the dynamics, physics, chemistry, and evolution of these regions, but our understanding of the molecular inventory of sources and how this is related to their physical

  6. Wire Integrity Field Survey of USAF Legacy Aircraft

    Science.gov (United States)

    2003-02-01

    Reunions des specialistes des techniques de estion du cycle de vie pour vehicules aeriens vieillissants ] To order the complete compilation report, use...Mechanisms and Control. Specialists’ Meeting on Life Management Techniques for Ageing Air Vehicles [Les mecanismes vieillissants et le controle...upgrades and modifications . Aging Mechanisms All wiring systems are subject to aging during their normal service life. Aging is the progressive

  7. Cold dark energy constraints from the abundance of galaxy clusters

    Science.gov (United States)

    Heneka, Caroline; Rapetti, David; Cataneo, Matteo; Mantz, Adam B.; Allen, Steven W.; von der Linden, Anja

    2018-01-01

    We constrain cold dark energy of negligible sound speed using galaxy cluster abundance observations. In contrast to standard quasi-homogeneous dark energy, negligible sound speed implies clustering of the dark energy fluid at all scales, allowing us to measure the effects of dark energy perturbations at cluster scales. We compare those models and set the stage for using non-linear information from semi-analytical modelling in cluster growth data analyses. For this, we recalibrate the halo mass function with non-linear characteristic quantities, the spherical collapse threshold and virial overdensity, that account for model and redshift-dependent behaviours, as well as an additional mass contribution for cold dark energy. We present the first constraints from this cold dark matter plus cold dark energy mass function using our cluster abundance likelihood, which self-consistently accounts for selection effects, covariances and systematic uncertainties. We combine cluster growth data with cosmic microwave background, supernovae Ia and baryon acoustic oscillation data, and find a shift between cold versus quasi-homogeneous dark energy of up to 1σ. We make a Fisher matrix forecast of constraints attainable with cluster growth data from the ongoing Dark Energy Survey (DES). For DES, we predict ∼ 50 per cent tighter constraints on (Ωm, w) for cold dark energy versus wCDM models, with the same free parameters. Overall, we show that cluster abundance analyses are sensitive to cold dark energy, an alternative, viable model that should be routinely investigated alongside the standard dark energy scenario.

  8. Cosmology and Dark Matter

    CERN Document Server

    Tkachev, Igor

    2017-01-01

    This lecture course covers cosmology from the particle physicist perspective. Therefore, the emphasis will be on the evidence for the new physics in cosmological and astrophysical data together with minimal theoretical frameworks needed to understand and appreciate the evidence. I review the case for non-baryonic dark matter and describe popular models which incorporate it. In parallel, the story of dark energy will be developed, which includes accelerated expansion of the Universe today, the Universe origin in the Big Bang, and support for the Inflationary theory in CMBR data.

  9. The use of unmanned aerial systems for the mapping of legacy uranium mines.

    Science.gov (United States)

    Martin, P G; Payton, O D; Fardoulis, J S; Richards, D A; Scott, T B

    2015-05-01

    Historical mining of uranium mineral veins within Cornwall, England, has resulted in a significant amount of legacy radiological contamination spread across numerous long disused mining sites. Factors including the poorly documented and aged condition of these sites as well as the highly localised nature of radioactivity limit the success of traditional survey methods. A newly developed terrain-independent unmanned aerial system [UAS] carrying an integrated gamma radiation mapping unit was used for the radiological characterisation of a single legacy mining site. Using this instrument to produce high-spatial-resolution maps, it was possible to determine the radiologically contaminated land areas and to rapidly identify and quantify the degree of contamination and its isotopic nature. The instrument was demonstrated to be a viable tool for the characterisation of similar sites worldwide. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. Dark Side of the Universe

    CERN Document Server

    2016-01-01

    The Dark Side of the Universe (DSU) workshops bring together a wide range of theorists and experimentalists to discuss current ideas on models of the dark side, and relate them to current and future experiments. This year's DSU will take place in the colorful Norwegian city of Bergen. Topics include dark matter, dark energy, cosmology, and physics beyond the standard model. One of the goals of the workshop is to expose in particular students and young researchers to the fascinating topics of dark matter and dark energy, and to provide them with the opportunity to meet some of the best researchers in these areas .

  11. Dark matter and its detection

    International Nuclear Information System (INIS)

    Bi Xiaojun; Qin Bo

    2011-01-01

    We first explain the concept of dark matter,then review the history of its discovery and the evidence of its existence. We describe our understanding of the nature of dark matter particles, the popular dark matter models,and why the weakly interacting massive particles (called WIMPs) are the most attractive candidates for dark matter. Then we introduce the three methods of dark matter detection: colliders, direct detection and indirect detection. Finally, we review the recent development of dark matter detection, including the new results from DAMA, CoGent, PAMELA, ATIC and Fermi. (authors)

  12. Dark energy and dark matter in galaxy halos

    International Nuclear Information System (INIS)

    Tetradis, N.

    2006-01-01

    We consider the possibility that the dark matter is coupled through its mass to a scalar field associated with the dark energy of the Universe. In order for such a field to play a role at the present cosmological distances, it must be effectively massless at galactic length scales. We discuss the effect of the field on the distribution of dark matter in galaxy halos. We show that the profile of the distribution outside the galaxy core remains largely unaffected and the approximately flat rotation curves persist. The dispersion of the dark matter velocity is enhanced by a potentially large factor relative to the case of zero coupling between dark energy and dark matter. The counting rates in terrestrial dark matter detectors are similarly enhanced. Existing bounds on the properties of dark matter candidates can be extended to the coupled case, by taking into account the enhancement factor

  13. Dark matter and dark energy: The critical questions

    International Nuclear Information System (INIS)

    Michael S. Turner

    2002-01-01

    Stars account for only about 0.5% of the content of the Universe; the bulk of the Universe is optically dark. The dark side of the Universe is comprised of: at least 0.1% light neutrinos; 3.5% ± 1% baryons; 29% ± 4% cold dark matter; and 66% ± 6% dark energy. Now that we have characterized the dark side of the Universe, the challenge is to understand it. The critical questions are: (1) What form do the dark baryons take? (2) What is (are) the constituent(s) of the cold dark matter? (3) What is the nature of the mysterious dark energy that is causing the Universe to speed up

  14. New interactions in the dark sector mediated by dark energy

    International Nuclear Information System (INIS)

    Brookfield, Anthony W.; Bruck, Carsten van de; Hall, Lisa M. H.

    2008-01-01

    Cosmological observations have revealed the existence of a dark matter sector, which is commonly assumed to be made up of one particle species only. However, this sector might be more complicated than we currently believe: there might be more than one dark matter species (for example, two components of cold dark matter or a mixture of hot and cold dark matter) and there may be new interactions between these particles. In this paper we study the possibility of multiple dark matter species and interactions mediated by a dark energy field. We study both the background and the perturbation evolution in these scenarios. We find that the background evolution of a system of multiple dark matter particles (with constant couplings) mimics a single fluid with a time-varying coupling parameter. However, this is no longer true on the perturbative level. We study the case of attractive and repulsive forces as well as a mixture of cold and hot dark matter particles

  15. Sterile neutrino portal to Dark Matter II: exact dark symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Escudero, Miguel; Rius, Nuria [Universidad de Valencia-CSIC, Departamento de Fisica Teorica and IFIC, C/Catedratico Jose Beltran, 2, 46980, Paterna (Spain); Sanz, Veronica [University of Sussex, Department of Physics and Astronomy, Brighton (United Kingdom)

    2017-06-15

    We analyze a simple extension of the standard model (SM) with a dark sector composed of a scalar and a fermion, both singlets under the SM gauge group but charged under a dark sector symmetry group. Sterile neutrinos, which are singlets under both groups, mediate the interactions between the dark sector and the SM particles, and generate masses for the active neutrinos via the seesaw mechanism. We explore the parameter space region where the observed Dark Matter relic abundance is determined by the annihilation into sterile neutrinos, both for fermion and scalar Dark Matter particles. The scalar Dark Matter case provides an interesting alternative to the usual Higgs portal scenario. We also study the constraints from direct Dark Matter searches and the prospects for indirect detection via sterile neutrino decays to leptons, which may be able to rule out Dark Matter masses below and around 100 GeV. (orig.)

  16. The Legacy of Utah's Country Schools, 1847-1896. Country School Legacy: Humanities on the Frontier.

    Science.gov (United States)

    Birkinshaw, Scott B.

    This section of the Country School Legacy: Humanities on the Frontier Project, funded by the National Endowment for the Humanities and sponsored by the Mountain Plains Library Association, traces the development of schools in Utah during the Territorial Period (1847-1896). Following a discussion of the influence of the Church of Jesus Christ of…

  17. Unified Description of Dark Energy and Dark Matter

    OpenAIRE

    Petry, Walter

    2008-01-01

    Dark energy in the universe is assumed to be vacuum energy. The energy-momentum of vacuum is described by a scale-dependent cosmological constant. The equations of motion imply for the density of matter (dust) the sum of the usual matter density (luminous matter) and an additional matter density (dark matter) similar to the dark energy. The scale-dependent cosmological constant is given up to an exponent which is approximated by the experimentally decided density parameters of dark matter and...

  18. The CHASE laboratory search for chameleon dark energy

    Energy Technology Data Exchange (ETDEWEB)

    Steffen, Jason H.; /Fermilab

    2010-11-01

    A scalar field is a favorite candidate for the particle responsible for dark energy. However, few theoretical means exist that can simultaneously explain the observed acceleration of the Universe and evade tests of gravity. The chameleon mechanism, whereby the properties of a particle depend upon the local environment, is one possible avenue. We present the results of the Chameleon Afterglow Search (CHASE) experiment, a laboratory probe for chameleon dark energy. CHASE marks a significant improvement other searches for chameleons both in terms of its sensitivity to the photon/chameleon coupling as well as its sensitivity to the classes of chameleon dark energy models and standard power-law models. Since chameleon dark energy is virtually indistinguishable from a cosmological constant, CHASE tests dark energy models in a manner not accessible to astronomical surveys.

  19. The CHASE laboratory search for chameleon dark energy

    International Nuclear Information System (INIS)

    Steffen, Jason H.

    2010-01-01

    A scalar field is a favorite candidate for the particle responsible for dark energy. However, few theoretical means exist that can simultaneously explain the observed acceleration of the Universe and evade tests of gravity. The chameleon mechanism, whereby the properties of a particle depend upon the local environment, is one possible avenue. We present the results of the Chameleon Afterglow Search (CHASE) experiment, a laboratory probe for chameleon dark energy. CHASE marks a significant improvement other searches for chameleons both in terms of its sensitivity to the photon/chameleon coupling as well as its sensitivity to the classes of chameleon dark energy models and standard power-law models. Since chameleon dark energy is virtually indistinguishable from a cosmological constant, CHASE tests dark energy models in a manner not accessible to astronomical surveys.

  20. Portuguese Cistercian Churches - An acoustic legacy

    Science.gov (United States)

    Rodrigues, Fabiel G.; Lanzinha, João C. G.; Martins, Ana M. T.

    2017-10-01

    The Cistercian Order (11th century) stands out as an apologist of the simplicity and austerity of the space. According to the Order of Cîteaux, only with an austere space, without any distractions, the true spiritual contemplation is achieved. This Order was an aggregator and consolidator pole during the Christian Reconquest. Thus, as it happens with other Religious Orders, Cîteaux has a vast heritage legacy. This heritage is witness, not only of the historical, but also social, political, and spiritual evolution. This legacy resumes the key principles to an austere liturgy, which requirements, in the beginning, are based on the simplicity of worship and of the connection between man and God. Later, these requirements allowed the development of the liturgy itself and its relation with the believers. Consequently, it can be concisely established an empirical approach between the Cistercian churches and the acoustics conditioning of these spaces. This outcome is fundamental in order to understand the connection between liturgy and the conception of the Cistercian churches as well as the constructed space and its history. So, an analysis of these principles is essential to establish the relation between acoustic and religious buildings design throughout history. It is also a mean of understanding the knowledge of acoustics principles that the Cistercian Order bequeathed to Portugal. This paper presents an empirical approach on Cistercian monastic churches acoustics. These spaces are the place where the greatest acoustic efforts are concentrated and it is also the space where the liturgy reaches greater importance. On the other hand, Portugal is a country which has an important Cistercian legacy over several periods of history. Consequently, the Portuguese Cistercian monastic churches are representative of the development of the liturgy, the design of spaces and of the acoustic requirements of their churches since the 12th century until the 21st century and it is of

  1. Legacy Risk Measure for Environmental Waste

    International Nuclear Information System (INIS)

    Eide, S. A.; Nitschke, R. L.

    2002-01-01

    The Idaho National Engineering and Environmental Laboratory (INEEL) is investigating the development of a comprehensive and quantitative risk model framework for environmental management activities at the site. Included are waste management programs (high-level waste, transuranic waste, low-level waste, mixed low-level waste, spent nuclear fuel, and special nuclear materials), major environmental restoration efforts, major decontamination and decommissioning projects, and planned long-term stewardship activities. Two basic types of risk estimates are included: risks from environmental management activities, and long-term legacy risks from wastes/materials. Both types of risks are estimated using the Environment, Safety, and Health Risk Assessment Program (ESHRAP) developed at the INEEL. Given these two types of risk calculations, the following evaluations can be performed: risk evaluation of an entire program (covering waste/material as it now exists through disposal or other e nd states); risk comparisons of alternative programs or activities; comparisons of risk benefit versus risk cost for activities or entire programs; ranking of programs or activities by risk; ranking of wastes/materials by risk; evaluation of site risk changes with time as activities progress; and integrated performance measurement using indicators such as injury/death and exposure rates. This paper discusses the definition and calculation of legacy risk measures and associated issues. The legacy risk measure is needed to support three of the seven types of evaluations listed above: comparisons of risk benefit versus risk cost, ranking of wastes/materials by risk, and evaluation of site risk changes with time

  2. Legacy Nitrate Impacts on Groundwater and Streams

    Science.gov (United States)

    Tesoriero, A. J.; Juckem, P. F.; Miller, M. P.

    2017-12-01

    Decades of recharge of high-nitrate groundwater have created a legacy—a mass of high-nitrate groundwater—that has implications for future nitrate concentrations in groundwater and in streams. In the United States, inorganic nitrogen fertilizer applications to the land surface have increased ten-fold since 1950, resulting in sharp increases in nitrate concentrations in recharging groundwater, which pose a risk to deeper groundwater and streams. This study assesses the factors that control time lags and eventual concentrations of legacy nitrate in groundwater and streams. Results from the USGS National Water-Quality Assessment Project are presented which elucidate nitrate trends in recharging groundwater, delineate redox zones and assess groundwater and stream vulnerability to legacy nitrate sources on a regional scale. This study evaluated trends and transformations of agricultural chemicals based on groundwater age and water chemistry data along flow paths from recharge areas to streams at 20 study sites across the United States. Median nitrate recharge concentrations in these agricultural areas have increased markedly over the last 50 years, from 4 to 7.5 mg N/L. The effect that nitrate accumulation in shallow aquifers will have on drinking water quality and stream ecosystems is dependent on the redox zones encountered along flow paths and on the age distribution of nitrate discharging to supply wells and streams. Delineating redox zones on a regional scale is complicated by the spatial variability of reaction rates. To overcome this limitation, we applied logistic regression and machine learning techniques to predict the probability of a specific redox condition in groundwater in the Chesapeake Bay watershed and the Fox-Wolf-Peshtigo study area in Wisconsin. By relating redox-active constituent concentrations in groundwater samples to indicators of residence time and/or electron donor availability, we were able to delineate redox zones on a regional scale

  3. Dichromatic dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Yang; Su, Meng; Zhao, Yue

    2013-02-01

    Both the robust INTEGRAL 511 keV gamma-ray line and the recent tentative hint of the 135 GeV gamma-ray line from Fermi-LAT have similar signal morphologies, and may be produced from the same dark matter annihilation. Motivated by this observation, we construct a dark matter model to explain both signals and to accommodate the two required annihilation cross sections that are different by more than six orders of magnitude. In our model, to generate the low-energy positrons for INTEGRAL, dark matter particles annihilate into a complex scalar that couples to photon via a charge-radius operator. The complex scalar contains an excited state decaying into the ground state plus an off-shell photon to generate a pair of positron and electron. Two charged particles with non-degenerate masses are necessary for generating this charge-radius operator. One charged particle is predicted to be long-lived and have a mass around 3.8 TeV to explain the dark matter thermal relic abundance from its late decay. The other charged particle is predicted to have a mass below 1 TeV given the ratio of the two signal cross sections. The 14 TeV LHC will concretely test the main parameter space of this lighter charged particle.

  4. Asymmetric condensed dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Aguirre, Anthony; Diez-Tejedor, Alberto, E-mail: aguirre@scipp.ucsc.edu, E-mail: alberto.diez@fisica.ugto.mx [Santa Cruz Institute for Particle Physics and Department of Physics, University of California, Santa Cruz, CA, 95064 (United States)

    2016-04-01

    We explore the viability of a boson dark matter candidate with an asymmetry between the number densities of particles and antiparticles. A simple thermal field theory analysis confirms that, under certain general conditions, this component would develop a Bose-Einstein condensate in the early universe that, for appropriate model parameters, could survive the ensuing cosmological evolution until now. The condensation of a dark matter component in equilibrium with the thermal plasma is a relativistic process, hence the amount of matter dictated by the charge asymmetry is complemented by a hot relic density frozen out at the time of decoupling. Contrary to the case of ordinary WIMPs, dark matter particles in a condensate must be lighter than a few tens of eV so that the density from thermal relics is not too large. Big-Bang nucleosynthesis constrains the temperature of decoupling to the scale of the QCD phase transition or above. This requires large dark matter-to-photon ratios and very weak interactions with standard model particles.

  5. Dark matter axions '96

    International Nuclear Information System (INIS)

    Sikivie, P.

    1996-01-01

    This report discusses why axions have been postulated to exist, what cosmology implies about their presence as cold dark matter in the galactic halo, how axions might be detected in cavities wherein strong magnetic fields stimulate their conversion into photons, and relations between axions' energy spectra and galactic halos' properties

  6. Dark matter candidates

    International Nuclear Information System (INIS)

    Turner, M.S.

    1989-01-01

    One of the simplest, yet most profound, questions we can ask about the Universe is, how much stuff is in it, and further what is that stuff composed of? Needless to say, the answer to this question has very important implications for the evolution of the Universe, determining both the ultimate fate and the course of structure formation. Remarkably, at this late date in the history of the Universe we still do not have a definitive answer to this simplest of questions---although we have some very intriguing clues. It is known with certainty that most of the material in the Universe is dark, and we have the strong suspicion that the dominant component of material in the Cosmos is not baryons, but rather is exotic relic elementary particles left over from the earliest, very hot epoch of the Universe. If true, the Dark Matter question is a most fundamental one facing both particle physics and cosmology. The leading particle dark matter candidates are: the axion, the neutralino, and a light neutrino species. All three candidates are accessible to experimental tests, and experiments are now in progress. In addition, there are several dark horse, long shot, candidates, including the superheavy magnetic monopole and soliton stars. 13 refs

  7. Dark Barchan Dunes

    Science.gov (United States)

    2004-01-01

    13 May 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows north polar sand dunes in the summertime. During winter and early spring, north polar dunes are covered with bright frost. When the frost sublimes away, the dunes appear darker than their surroundings. To a geologist, sand has a very specific meaning. A sand grain is defined independently of its composition; it is a particle with a size between 62.5 and 2000 microns. Two thousand microns equals 2 millimeters. The dunes are dark because they are composed of sand grains made of dark minerals and/or rock fragments. Usually, dark grains indicate the presence of unoxidized iron, for example, the dark volcanic rocks of Hawaii, Iceland, and elsewhere. This dune field is located near 71.7oN, 51.3oW. Dune slip faces indicate winds that blow from the upper left toward lower right. This picture covers an area approximately 3 km (1.9 mi) across and is illuminated by sunlight from the lower left.

  8. with dark matter

    Indian Academy of Sciences (India)

    2012-11-16

    Nov 16, 2012 ... to have a dramatic impact on neutrino physics, dark matter and all fermion masses and mixings. Keywords. Radiative see-saw; fermion masses; grand unification. PACS Nos 12.10.Dm; 12.60.Jv; 14.60.Pq. 1. Introduction. In SO(10) grand unified theory which contains all standard fermions of one generation.

  9. Template Composite Dark Matter

    DEFF Research Database (Denmark)

    Drach, Vincent; Hietanen, Ari; Pica, Claudio

    2015-01-01

    We present a non perturbative study of SU(2) gauge theory with two fundamental Dirac flavours. We discuss how the model can be used as a template for composite Dark Matter (DM). We estimate one particular interaction of the DM candidate with the Standard Model : the interaction through photon...

  10. Exceptional composite dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Ballesteros, Guillermo [Universite Paris Saclay, CEA, CNRS, Institut de Physique Theorique, Gif-sur-Yvette (France); Carmona, Adrian [CERN, Theoretical Physics Department, Geneva (Switzerland); Chala, Mikael [Universitat de Valencia y IFIC, Universitat de Valencia-CSIC, Departament de Fisica Teorica, Burjassot, Valencia (Spain)

    2017-07-15

    We study the dark matter phenomenology of non-minimal composite Higgs models with SO(7) broken to the exceptional group G{sub 2}. In addition to the Higgs, three pseudo-Nambu-Goldstone bosons arise, one of which is electrically neutral. A parity symmetry is enough to ensure this resonance is stable. In fact, if the breaking of the Goldstone symmetry is driven by the fermion sector, this Z{sub 2} symmetry is automatically unbroken in the electroweak phase. In this case, the relic density, as well as the expected indirect, direct and collider signals are then uniquely determined by the value of the compositeness scale, f. Current experimental bounds allow one to account for a large fraction of the dark matter of the Universe if the dark matter particle is part of an electroweak triplet. The totality of the relic abundance can be accommodated if instead this particle is a composite singlet. In both cases, the scale f and the dark matter mass are of the order of a few TeV. (orig.)

  11. Little composite dark matter

    Science.gov (United States)

    Balkin, Reuven; Perez, Gilad; Weiler, Andreas

    2018-02-01

    We examine the dark matter phenomenology of a composite electroweak singlet state. This singlet belongs to the Goldstone sector of a well-motivated extension of the Littlest Higgs with T-parity. A viable parameter space, consistent with the observed dark matter relic abundance as well as with the various collider, electroweak precision and dark matter direct detection experimental constraints is found for this scenario. T-parity implies a rich LHC phenomenology, which forms an interesting interplay between conventional natural SUSY type of signals involving third generation quarks and missing energy, from stop-like particle production and decay, and composite Higgs type of signals involving third generation quarks associated with Higgs and electroweak gauge boson, from vector-like top-partners production and decay. The composite features of the dark matter phenomenology allows the composite singlet to produce the correct relic abundance while interacting weakly with the Higgs via the usual Higgs portal coupling λ _{ {DM}}˜ O(1%), thus evading direct detection.

  12. Simplified Dark Matter Models

    OpenAIRE

    Morgante, Enrico

    2018-01-01

    I review the construction of Simplified Models for Dark Matter searches. After discussing the philosophy and some simple examples, I turn the attention to the aspect of the theoretical consistency and to the implications of the necessary extensions of these models.

  13. Composite Dark Sectors

    International Nuclear Information System (INIS)

    Carmona, Adrian

    2015-06-01

    We introduce a new paradigm in Composite Dark Sectors, where the full Standard Model (including the Higgs boson) is extended with a strongly-interacting composite sector with global symmetry group G spontaneously broken to H is contained in G. We show that, under well-motivated conditions, the lightest neutral pseudo Nambu-Goldstone bosons are natural dark matter candidates for they are protected by a parity symmetry not even broken in the electroweak phase. These models are characterized by only two free parameters, namely the typical coupling g D and the scale f D of the composite sector, and are therefore very predictive. We consider in detail two minimal scenarios, SU(3)/[SU(2) x U(1)] and [SU(2) 2 x U(1)]/[SU(2) x U(1)], which provide a dynamical realization of the Inert Doublet and Triplet models, respectively. We show that the radiatively-induced potential can be computed in a five-dimensional description with modified boundary conditions with respect to Composite Higgs models. Finally, the dark matter candidates are shown to be compatible, in a large region of the parameter space, with current bounds from dark matter searches as well as electroweak and collider constraints on new resonances.

  14. Dark influences: imprints of dark satellites on dwarf galaxies

    NARCIS (Netherlands)

    Starkenburg, T. K.; Helmi, A.

    Context. In the context of the current Λ cold dark matter cosmological model small dark matter halos are abundant and satellites of dwarf galaxies are expected to be predominantly dark. Since low mass galaxies have smaller baryon fractions, interactions with these satellites may leave particularly

  15. Radioactive legacies from medicine and industry

    International Nuclear Information System (INIS)

    Linder, R.; Rodriguez, J.

    2005-01-01

    Due to the unintended disposal of radioactive legacies (waste from medicine, industry or private persons) radioactive material occasionally enters the disposal ways of conventional waste. The Swiss Federal Office of Public Health (SFOPH) and the Swiss accident Insurance Fund (Swiss) are the licensing authorities and regulatory agencies of the handling with radioactive materials for non-nuclear use. The aim is to avoid such incidents with concrete measures and so to preserve men and environment from the negative effect of not correctly disposed radioactive waste. (orig.)

  16. Eventscapes and the creation of event legacies

    OpenAIRE

    Brown, G.; Lee, I.S.; King, Katherine; Shipway, Richard

    2015-01-01

    Attention is directed to the difference in event legacies created by mega-events which often cause dramatic physical changes in urban environments and those which accompany events which leave very little imprint on the landscape where they are held. The Tour Down Under cycle race, which is held annually in South Australia, is examined as an example of the latter. The spatial pattern of the event and the range of settings which support it are presented as an eventscape by drawing on concepts s...

  17. Integrating commercial and legacy systems with EPICS

    International Nuclear Information System (INIS)

    Hill, J.O.; Kasemir, K.U.

    1997-01-01

    The Experimental Physics and Industrial Control System (EPICS) is a software toolkit, developed by a worldwide collaboration, which significantly reduces the level of effort required to implement a new control system. Recent developments now also significantly reduce the level of effort required to integrate commercial, legacy and/or site-authored control systems with EPICS. This paper will illustrate with an example both the level and type of effort required to use EPICS with other control system components as well as the benefits that may arise

  18. Dark clouds in particle physics and cosmology: the issues of dark matter and dark energy

    International Nuclear Information System (INIS)

    Zhang Xinmin

    2011-01-01

    Unveiling the nature of dark matter and dark energy is one of the main tasks of particle physics and cosmology in the 21st century. We first present an overview of the history and current status of research in cosmology, at the same time emphasizing the new challenges in particle physics. Then we focus on the scientific issues of dark energy, dark matter and anti-matter, and review the recent progress made in these fields. Finally, we discuss the prospects for future research on the experimental probing of dark matter and dark energy in China. (authors)

  19. Neutrinos and dark energy

    Energy Technology Data Exchange (ETDEWEB)

    Schrempp, L.

    2008-02-15

    From the observed late-time acceleration of cosmic expansion arises the quest for the nature of Dark Energy. As has been widely discussed, the cosmic neutrino background naturally qualifies for a connection with the Dark Energy sector and as a result could play a key role for the origin of cosmic acceleration. In this thesis we explore various theoretical aspects and phenomenological consequences arising from non-standard neutrino interactions, which dynamically link the cosmic neutrino background and a slowly-evolving scalar field of the dark sector. In the considered scenario, known as Neutrino Dark Energy, the complex interplay between the neutrinos and the scalar field not only allows to explain cosmic acceleration, but intriguingly, as a distinct signature, also gives rise to dynamical, time-dependent neutrino masses. In a first analysis, we thoroughly investigate an astrophysical high energy neutrino process which is sensitive to neutrino masses. We work out, both semi-analytically and numerically, the generic clear-cut signatures arising from a possible time variation of neutrino masses which we compare to the corresponding results for constant neutrino masses. Finally, we demonstrate that even for the lowest possible neutrino mass scale, it is feasible for the radio telescope LOFAR to reveal a variation of neutrino masses and therefore to probe the nature of Dark Energy within the next decade. A second independent analysis deals with the recently challenged stability of Neutrino Dark Energy against the strong growth of hydrodynamic perturbations, driven by the new scalar force felt between neutrinos. Within the framework of linear cosmological perturbation theory, we derive the equation of motion of the neutrino perturbations in a model-independent way. This equation allows to deduce an analytical stability condition which translates into a comfortable upper bound on the scalar-neutrino coupling which is determined by the ratio of the densities in cold dark

  20. Non-baryonic dark matter

    International Nuclear Information System (INIS)

    Berkes, I.

    1996-01-01

    This article discusses the nature of the dark matter and the possibility of the detection of non-baryonic dark matter in an underground experiment. Among the useful detectors the low temperature bolometers are considered in some detail. (author)

  1. An elusive vector dark matter

    Directory of Open Access Journals (Sweden)

    Chuan-Ren Chen

    2015-02-01

    Full Text Available Even though the sensitivity of direct dark matter search experiments reaches the level of about 10−45 cm2, no confident signal of dark matter has been observed. We point out that, if dark matter is a vector boson, the null result in direct dark matter search experiments may be due to the destructive effects in dark-matter–nucleon elastic scattering. We illustrate the scenario using a modified Higgs portal model that includes exotic quarks. The significant cancellation can occur for a certain mass gap between new heavy quark and dark matter. As a result, the spin-independent dark-matter–nucleon elastic scattering is so suppressed that the future direct search experiments will hardly observe the signal of dark matter.

  2. Reconstructing the dark sector interaction with LISA

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Rong-Gen; Yang, Tao [CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, P.O. Box 2735, Beijing 100190 (China); Tamanini, Nicola, E-mail: cairg@itp.ac.cn, E-mail: nicola.tamanini@cea.fr, E-mail: yangtao@itp.ac.cn [Institut de Physique Théorique, CEA-Saclay, CNRS UMR 3681, Université Paris-Saclay, F-91191 Gif-sur-Yvette (France)

    2017-05-01

    We perform a forecast analysis of the ability of the LISA space-based interferometer to reconstruct the dark sector interaction using gravitational wave standard sirens at high redshift. We employ Gaussian process methods to reconstruct the distance-redshift relation in a model independent way. We adopt simulated catalogues of standard sirens given by merging massive black hole binaries visible by LISA, with an electromagnetic counterpart detectable by future telescopes. The catalogues are based on three different astrophysical scenarios for the evolution of massive black hole mergers based on the semi-analytic model of E. Barausse, Mon. Not. Roy. Astron. Soc. 423 (2012) 2533. We first use these standard siren datasets to assess the potential of LISA in reconstructing a possible interaction between vacuum dark energy and dark matter. Then we combine the LISA cosmological data with supernovae data simulated for the Dark Energy Survey. We consider two scenarios distinguished by the time duration of the LISA mission: 5 and 10 years. Using only LISA standard siren data, the dark sector interaction can be well reconstructed from redshift z ∼1 to z ∼3 (for a 5 years mission) and z ∼1 up to z ∼5 (for a 10 years mission), though the reconstruction is inefficient at lower redshift. When combined with the DES datasets, the interaction is well reconstructed in the whole redshift region from 0 z ∼ to z ∼3 (5 yr) and z ∼0 to z ∼5 (10 yr), respectively. Massive black hole binary standard sirens can thus be used to constrain the dark sector interaction at redshift ranges not reachable by usual supernovae datasets which probe only the z ∼< 1.5 range. Gravitational wave standard sirens will not only constitute a complementary and alternative way, with respect to familiar electromagnetic observations, to probe the cosmic expansion, but will also provide new tests to constrain possible deviations from the standard ΛCDM dynamics, especially at high redshift.

  3. Biological field stations: research legacies and sites for serendipity

    Science.gov (United States)

    William K. Michener; Keith L. Bildstein; Arthur McKee; Robert R. Parmenter; William W. Hargrove; Deedra McClearn; Mark Stromberg

    2009-01-01

    Biological field stations are distributed throughout North America, capturing much of the ecological variability present at the continental scale and encompassing many unique habitats. In addition to their role in supporting research and education, field stations offer legacies of data, specimens, and accumulated knowledge. Such legacies often provide the only...

  4. Jack Wescott and Donald F. Smith. The Legacy Project

    Science.gov (United States)

    Moye, Johnny J.; Wescott, Jack W.; Smith, Donald F.

    2017-01-01

    This is the tenth in a series of articles entitled "The Legacy Project." The Legacy Project focuses on the lives and actions of leaders who have forged our profession into what it is today. Members of the profession owe a debt of gratitude to these leaders. One simple way to demonstrate that gratitude is to recognize these leaders and…

  5. Welcome to the dark side

    CERN Multimedia

    Hogan, Jenny

    2007-01-01

    "Physicists says that 96% of the Universe is unseen, and appeal tot he ideas of "dark matter" and "dark energy" to make up the difference. In the first of two articles, jeanny hogan reports that attempts to identify the mysterious dark matter are on the verge of success. In the second, Geoff Brumfiel asks why dark energy, hailed as a breakthrough when discovered a decade ago, is proving more frustrating than ever tot he scientists who study it." (4,5 pages)

  6. Signals of Supersymmetric Dark Matter

    OpenAIRE

    Abbas, Afsar

    1999-01-01

    The Lightest Supersymmetric Particle predicted in most of the supersymmetric scenarios is an ideal candidate for the dark matter of cosmology. Their detection is of extreme significance today. Recently there have been intriguing signals of a 59 Gev neutralino dark matter at DAMA in Gran Sasso. We look at other possible signatures of dark matter in astrophysical and geological frameworks. The passage of the earth through dense clumps of dark matter would produce large quantities of heat in the...

  7. Black Holes as Dark Matter

    OpenAIRE

    Frampton, Paul H.

    2009-01-01

    While the energy of the universe has been established to be about 0.04 baryons, 0.24 dark matter and 0.72 dark energy, the cosmological entropy is almost entirely, about $(1 - 10^{-15})$, from black holes and only $10^{-15}$ from everything else. This identification of all dark matter as black holes is natural in statistical mechanics. Cosmological history of dark matter is discussed.

  8. Legacies of Amazonian dark earths on forest composition, structure and dynamics

    NARCIS (Netherlands)

    Quintero Vallejo, E.M.

    2015-01-01

    Summary

    Amazonian forest is seen as the archetype of pristine forests, untouched by humans, but this romantic view is far from reality. In recent years, there is increasing evidence of long and extensive landscape modification by humans. Processes of permanent inhabitation,

  9. Legacies of Amazonian dark earths on forest composition, structure and dynamics

    NARCIS (Netherlands)

    Quintero Vallejo, E.M.

    2015-01-01

    Summary

    Amazonian forest is seen as the archetype of pristine forests, untouched by humans, but this romantic view is far from reality. In recent years, there is increasing evidence of long and extensive landscape modification by humans. Processes of permanent inhabitation,

  10. Memory and Forgiveness: Addressing the Legacy of the Dark Years in Contemporary French Politics

    OpenAIRE

    Villaseñor, Leticia

    2015-01-01

    On July 16, 1995, Jacques Chirac became the first president to publicly acknowledge the French Republic’s shared responsibility in the persecution and deportation of thousands of Jews to Nazi concentration camps during World War II. Speaking at the anniversary of the Vél d’Hiv roundup, Chirac issued a public apology for the French state’s complicit role in the deportation and extermination of Jews, while emphasizing that the errors committed during the war were a ‘faute collective’ and thus t...

  11. Legacy management: An old challenge with a new focus

    International Nuclear Information System (INIS)

    Gillogly, Mari; ); Sneve, Malgorzata; Smith, Graham

    2017-01-01

    The NEA Expert Group on Legacy Management (EGLM) aims to promote a practical and optimised approach for the regulatory supervision of nuclear legacy sites and installations. NEA member countries share their experiences and approaches on legacy management and have submitted case studies to the EGLM that illustrate the common challenges and approaches of many countries. The first report of the expert group will be based on these case studies and will be released in late 2017. A new, broader focus on decommissioning and legacy management issues within the NEA is expected to take shape in early 2018, carrying forward the mission to develop and promote a practical and optimised approach for the regulatory supervision of nuclear legacy sites and installations

  12. Caustic rings of dark matter

    OpenAIRE

    Sikivie, Pierre

    1997-01-01

    It is shown that the infall of collisionless dark matter onto isolated galaxies produces a series of caustic rings in the halo dark matter distribution. The properties of these caustics are investigated. The density profile of the caustic is derived for a specific case. Bumps in the rotation curve of NGC 3198 are interpreted as due to caustic rings of dark matter.

  13. Dark Matter Searches at LHC

    CERN Document Server

    Terashi, Koji; The ATLAS collaboration

    2017-01-01

    This talk will present dark matter searches at the LHC in the PIC2017 conference. The main emphasis is placed on the direct dark matter searches while the interpretation of searches for SUSY and invisible Higgs signals for the dark matter is also presented.

  14. The DarkSide Program

    Directory of Open Access Journals (Sweden)

    Rossi B.

    2016-01-01

    Full Text Available DarkSide-50 at Gran Sasso underground laboratory (LNGS, Italy, is a direct dark matter search experiment based on a liquid argon TPC. DS-50 has completed its first dark matter run using atmospheric argon as target. The detector performances and the results of the first physics run are presented in this proceeding.

  15. How dark chocolate is processed

    Science.gov (United States)

    This month’s column will continue the theme of “How Is It Processed?” The column will focus on dark chocolate. The botanical name for the cacao tree is Theobroma cacao, which literally means “food of the Gods.” Dark chocolate is both delicious and nutritious. Production of dark chocolate will be des...

  16. Vulnerability of streams to legacy nitrate sources

    Science.gov (United States)

    Tesoriero, Anthony J.; Duff, John H.; Saad, David A.; Spahr, Norman E.; Wolock, David M.

    2013-01-01

    The influence of hydrogeologic setting on the susceptibility of streams to legacy nitrate was examined at seven study sites having a wide range of base flow index (BFI) values. BFI is the ratio of base flow to total streamflow volume. The portion of annual stream nitrate loads from base flow was strongly correlated with BFI. Furthermore, dissolved oxygen concentrations in streambed pore water were significantly higher in high BFI watersheds than in low BFI watersheds suggesting that geochemical conditions favor nitrate transport through the bed when BFI is high. Results from a groundwater-surface water interaction study at a high BFI watershed indicate that decades old nitrate-laden water is discharging to this stream. These findings indicate that high nitrate levels in this stream may be sustained for decades to come regardless of current practices. It is hypothesized that a first approximation of stream vulnerability to legacy nutrients may be made by geospatial analysis of watersheds with high nitrogen inputs and a strong connection to groundwater (e.g., high BFI).

  17. Legacy and Emerging Perfluoroalkyl Substances Are ...

    Science.gov (United States)

    Long-chain per- and polyfluoroalkyl substances (PFASs) are being replaced by short-chain PFASs and fluorinated alternatives. For ten legacy PFASs and seven recently discovered perfluoroalkyl ether carboxylic acids (PFECAs), we report (1) their occurrence in the Cape Fear River (CFR) watershed, (2) their fate in water treatment processes, and (3) their adsorbability on powdered activated carbon (PAC). In the headwater region of the CFR basin, PFECAs were not detected in raw water of a drinking water treatment plant (DWTP), but concentrations of legacy PFASs were high. The U.S. Environmental Protection Agency’s lifetime health advisory level (70 ng/L) for perfluorooctanesulfonic acid and perfluorooctanoic acid (PFOA) was exceeded on 57 of 127 sampling days. In raw water of a DWTP downstream of a PFAS manufacturer, the mean concentration of perfluoro-2-propoxypropanoic acid (PFPrOPrA), a replacement for PFOA, was 631 ng/L (n = 37). Six other PFECAs were detected, with three exhibiting chromatographic peak areas up to 15 times that of PFPrOPrA. At this DWTP, PFECA removal by coagulation, ozonation, biofiltration, and disinfection was negligible. The adsorbability of PFASs on PAC increased with increasing chain length. Replacing one CF2 group with an ether oxygen decreased the affinity of PFASs for PAC, while replacing additional CF2 groups did not lead to further affinity changes. The USEPA’s recently completed Unregulated Contaminant Monitoring Rule 3 (UCMR3) p

  18. The mycological legacy of Elias Magnus Fries.

    Science.gov (United States)

    Petersen, Ronald H; Knudsen, Henning

    2015-06-01

    The taxonomic concepts which originated with or were accepted by Elias Magnus Fries were presented during his lifetime in the printed word, illustrative depiction, and in collections of dried specimens. This body of work was welcomed by the mycological and botanical communities of his time: students and associates aided Fries and after his passing carried forward his taxonomic ideas. His legacy spawned a line of Swedish and Danish mycologists intent on perpetuating the Fries tradition: Hampus von Post, Lars Romell, Seth Lundell and John Axel Nannfeldt in Sweden; Emil Rostrup, Severin Petersen and Jakob Lange in Denmark. Volumes of color paintings and several exsiccati, most notably one edited by Lundell and Nannfeldt attached fungal portraits and preserved specimens (and often photographs) to Fries names. The result is a massive resource from which to harvest the name-concept relationship with clarity. In the 20th century, nomenclatural commissions legislated Fries's Systema and Elenchus as the "starting point" for names of most fungi, giving these books special recognition. The present paper attempts to trace Fries's legacy from his lifetime to the recent past.

  19. Accounting for Readout Dark in ACS/WFC Superbiases

    Science.gov (United States)

    Ryon, J. E.; Grogin, N. A.; Coe, D.

    2017-12-01

    We investigate the properties of excess dark current accumulated during the 100-second full-frame readout of the Advanced Camera for Surveys (ACS) Wide Field Channel (WFC) detectors. This excess dark current, called "readout dark", gives rise to ambient background gradients and hot columns in each ACS/WFC image. We present an analysis of simulated readout dark images developed in ACS ISR 2014-02, and find that the results from the simulated data cannot be fully reconciled with the results from observed bias images. We develop a new method to estimate the readout dark noise properties in ACS/WFC observations instead of using simulated images. While readout dark signal is removed from science images during the bias correction step in CALACS, the additional noise from the readout dark is currently not taken into account. We will update the ERR extensions of superbias images to include the appropriate noise from the ambient readout dark gradient and stable hot columns. We will also flag unstable hot columns in the DQ extensions of the superbiases. A new reference file pipeline for ACS/WFC that will implement these changes is currently under construction.

  20. Interacting dark matter disguised as warm dark matter

    International Nuclear Information System (INIS)

    Boehm, Celine; Riazuelo, Alain; Hansen, Steen H.; Schaeffer, Richard

    2002-01-01

    We explore some of the consequences of dark-matter-photon interactions on structure formation, focusing on the evolution of cosmological perturbations and performing both an analytical and a numerical study. We compute the cosmic microwave background anisotropies and matter power spectrum in this class of models. We find, as the main result, that when dark matter and photons are coupled, dark matter perturbations can experience a new damping regime in addition to the usual collisional Silk damping effect. Such dark matter particles (having quite large photon interactions) behave like cold dark matter or warm dark matter as far as the cosmic microwave background anisotropies or matter power spectrum are concerned, respectively. These dark-matter-photon interactions leave specific imprints at sufficiently small scales on both of these two spectra, which may allow us to put new constraints on the acceptable photon-dark-matter interactions. Under the conservative assumption that the abundance of 10 12 M · galaxies is correctly given by the cold dark matter, and without any knowledge of the abundance of smaller objects, we obtain the limit on the ratio of the dark-matter-photon cross section to the dark matter mass σ γ-DM /m DM -6 σ Th /(100 GeV)≅6x10 -33 cm 2 GeV -1

  1. Quantum Field Theory of Interacting Dark Matter/Dark Energy: Dark Monodromies

    CERN Document Server

    D'Amico, Guido; Kaloper, Nemanja

    2016-11-28

    We discuss how to formulate a quantum field theory of dark energy interacting with dark matter. We show that the proposals based on the assumption that dark matter is made up of heavy particles with masses which are very sensitive to the value of dark energy are strongly constrained. Quintessence-generated long range forces and radiative stability of the quintessence potential require that such dark matter and dark energy are completely decoupled. However, if dark energy and a fraction of dark matter are very light axions, they can have significant mixings which are radiatively stable and perfectly consistent with quantum field theory. Such models can naturally occur in multi-axion realizations of monodromies. The mixings yield interesting signatures which are observable and are within current cosmological limits but could be constrained further by future observations.

  2. From legacy and client/server systems to components in healthcare information systems in Finland.

    Science.gov (United States)

    Mykkänen, J; Korpela, M; Eerola, A; Porrasmaa, J; Ruonamaa, H; Sormunen, M

    2001-01-01

    A strategy and toolset (FixIT) for migrating a specific type of legacy systems--based on the FileMan DBMS of the U.S. Department of Veterans Affairs--to a two-tier client/server and web browser-based architecture was presented in MEDINFO'98. In the current paper we discuss the further migration to a multitier software component architecture. A literature survey and industry contacts were used to specify an open, component-based target architecture for healthcare information systems to be reached by the year 2005, as well as a phased migration strategy from the present FileMan/FixIT-based systems towards the target. The target architecture is based on large-grained business components and accommodates heterogeneous elements on the intra-component, intra-application, intra-organization and inter-organizational levels. Four logical tiers are identified within a business component. Three migration paths are specified for different cases: the tier-by-tier, piece-by-piece, and web-wrapping paths. It is argued that the architecture, supported by off-the-shelf toolsets, application frameworks and a new software development process, makes it possible to turn legacy systems into a valuable asset, split monolithic applications into reusable components, and ultimately replace the legacy parts at a feasible pace

  3. Dark Skies Rangers

    Science.gov (United States)

    Doran, Rosa

    2015-08-01

    Creating awareness about the importance of the protection of our dark skies is the main goal of the Dark Skies Rangers project, a joint effort from the NOAO and the Galileo Teacher Training Program. Hundreds of schools and thousands of students have been reached by this program. We will focus in particular on the experience being developed in Portugal where several municipalities have now received street light auditing produced by students with suggestions on how to enhance the energy efficiency of illumination of specific urban areas. In the International Year of Light we are investing our efforts in exporting the successful Portuguese experience to other countries. The recipe is simple: train teachers, engage students, foster the participation of local community and involve local authorities in the process. In this symposium we hope to draft the cookbook for the near future.

  4. CN in dark clouds

    International Nuclear Information System (INIS)

    Churchwell, E.; Bieging, J.H.

    1983-01-01

    We have detected CN (N = 1--0) emission toward six locations in the Taurus dark cloud complex, but not toward L183 or B227. The two hyperfine components, F = 3/2--1/2 and F = 5/2--3/2 (of J = 3/2--1/2), have intensity ratios near unity toward four locations in Taurus, consistent with large line optical depths. CN column densities are found to be > or approx. =6 x 10 13 cm -2 in those directions where the hyperfine ratios are near unity. By comparing CN with NH 3 and C 18 O column densities, we find that the relative abundance of CN in the Taurus cloudlets is at least a factor of 10 greater than in L183. In this respect, CN fits the pattern of enhanced abundances of carbon-bearing molecules (in partricular the cyanopolyynes) in the Taurus cloudlets relative to similar dark clouds outside Taurus

  5. Dark matter from unification

    DEFF Research Database (Denmark)

    Kainulainen, Kimmo; Tuominen, Kimmo; Virkajärvi, Jussi Tuomas

    2013-01-01

    We consider a minimal extension of the Standard Model (SM), which leads to unification of the SM coupling constants, breaks electroweak symmetry dynamically by a new strongly coupled sector and leads to novel dark matter candidates. In this model, the coupling constant unification requires...... eigenstates of this sector and determine the resulting relic density. The results are constrained by available data from colliders and direct and indirect dark matter experiments. We find the model viable and outline briefly future research directions....... the existence of electroweak triplet and doublet fermions singlet under QCD and new strong dynamics underlying the Higgs sector. Among these new matter fields and a new right handed neutrino, we consider the mass and mixing patterns of the neutral states. We argue for a symmetry stabilizing the lightest mass...

  6. Baryonic dark matter

    Science.gov (United States)

    Silk, Joseph

    1991-01-01

    Both canonical primordial nucleosynthesis constraints and large-scale structure measurements, as well as observations of the fundamental cosmological parameters, appear to be consistent with the hypothesis that the universe predominantly consists of baryonic dark matter (BDM). The arguments for BDM to consist of compact objects that are either stellar relics or substellar objects are reviewed. Several techniques for searching for halo BDM are described.

  7. A dark energy multiverse

    Energy Technology Data Exchange (ETDEWEB)

    Robles-Perez, Salvador; Martin-Moruno, Prado; Rozas-Fernandez, Alberto; Gonzalez-Diaz, Pedro F [Colina de los Chopos, Instituto de Matematicas y Fisica Fundamental, Consejo Superior de Investigaciones CientIficas, Serrano 121, 28006 Madrid (Spain)

    2007-05-21

    We present cosmic solutions corresponding to universes filled with dark and phantom energy, all having a negative cosmological constant. All such solutions contain infinite singularities, successively and equally distributed along time, which can be either big bang/crunches or big rips singularities. Classically these solutions can be regarded as associated with multiverse scenarios, being those corresponding to phantom energy that may describe the current accelerating universe. (fast track communication)

  8. Dark Web 101

    Science.gov (United States)

    2016-07-21

    input data to get access (email or online banks), unlinked content (unpublished blogs or or- ganizational databases), proprietary data (study results...reigns, enables darknet communication. One Chinese blogger who established a darknet blog said “This is a free Chinese Internet world, here you can...thought my first contact with the dark web would be on a Chinese website. I hope the webmaster continues their good work13.” These tactics reflect

  9. Dark Sand Dunes

    Science.gov (United States)

    2005-01-01

    13 January 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows dark sand dunes in the north polar region of Mars. The dominant winds responsible for these dunes blew from the lower left (southwest). They are located near 76.6oN, 257.2oW. The picture covers an area 3 km (1.9 mi) across; sunlight illuminates the scene from the upper right.

  10. DARK MATTER: Optical shears

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    Evidence for dark matter continues to build up. Last year (December 1993, page 4) excitement rose when the French EROS (Experience de Recherche d'Objets Sombres) and the US/Australia MACHO collaborations reported hints that small inert 'brown dwarf stars could provide some of the Universe's missing matter. In the 1930s, astronomers first began to suspect that there is a lot more to the Universe than meets the eye

  11. Dark matter wants Linear Collider

    International Nuclear Information System (INIS)

    Matsumoto, S.; Asano, M.; Fujii, K.; Takubo, Y.; Honda, T.; Saito, T.; Yamamoto, H.; Humdi, R.S.; Ito, H.; Kanemura, S; Nabeshima, T.; Okada, N.; Suehara, T.

    2011-01-01

    One of the main purposes of physics at the International Linear Collider (ILC) is to study the property of dark matter such as its mass, spin, quantum numbers, and interactions with particles of the standard model. We discuss how the property can or cannot be investigated at the ILC using two typical cases of dark matter scenario: 1) most of new particles predicted in physics beyond the standard model are heavy and only dark matter is accessible at the ILC, and 2) not only dark matter but also other new particles are accessible at the ILC. We find that, as can be easily imagined, dark matter can be detected without any difficulties in the latter case. In the former case, it is still possible to detect dark matter when the mass of dark matter is less than a half mass of the Higgs boson.

  12. Interstellar ice : The Infrared Space Observatory legacy

    NARCIS (Netherlands)

    Gibb, EL; Whittet, DCB; Boogert, ACA; Tielens, AGGM

    We present 2.5-30 mum spectra from the Short-Wavelength Spectrometer of the Infrared Space Observatory for a total of 23 sources. The sources include embedded young stellar objects spanning a wide range of mass and luminosity, together with field stars sampling quiescent dark clouds and the diffuse

  13. Cold dark matter plus not-so-clumpy dark relics

    Science.gov (United States)

    Diamanti, Roberta; Ando, Shin'ichiro; Gariazzo, Stefano; Mena, Olga; Weniger, Christoph

    2017-06-01

    Various particle physics models suggest that, besides the (nearly) cold dark matter that accounts for current observations, additional but sub-dominant dark relics might exist. These could be warm, hot, or even contribute as dark radiation. We present here a comprehensive study of two-component dark matter scenarios, where the first component is assumed to be cold, and the second is a non-cold thermal relic. Considering the cases where the non-cold dark matter species could be either a fermion or a boson, we derive consistent upper limits on the non-cold dark relic energy density for a very large range of velocity dispersions, covering the entire range from dark radiation to cold dark matter. To this end, we employ the latest Planck Cosmic Microwave Background data, the recent BOSS DR11 and other Baryon Acoustic Oscillation measurements, and also constraints on the number of Milky Way satellites, the latter of which provides a measure of the suppression of the matter power spectrum at the smallest scales due to the free-streaming of the non-cold dark matter component. We present the results on the fraction fncdm of non-cold dark matter with respect to the total dark matter for different ranges of the non-cold dark matter masses. We find that the 2σ limits for non-cold dark matter particles with masses in the range 1-10 keV are fncdm100 keV range they are fncdm<=0.43 (0.45), respectively.

  14. Cold dark matter plus not-so-clumpy dark relics

    International Nuclear Information System (INIS)

    Diamanti, Roberta; Ando, Shin'ichiro; Weniger, Christoph; Gariazzo, Stefano; Mena, Olga

    2017-01-01

    Various particle physics models suggest that, besides the (nearly) cold dark matter that accounts for current observations, additional but sub-dominant dark relics might exist. These could be warm, hot, or even contribute as dark radiation. We present here a comprehensive study of two-component dark matter scenarios, where the first component is assumed to be cold, and the second is a non-cold thermal relic. Considering the cases where the non-cold dark matter species could be either a fermion or a boson, we derive consistent upper limits on the non-cold dark relic energy density for a very large range of velocity dispersions, covering the entire range from dark radiation to cold dark matter. To this end, we employ the latest Planck Cosmic Microwave Background data, the recent BOSS DR11 and other Baryon Acoustic Oscillation measurements, and also constraints on the number of Milky Way satellites, the latter of which provides a measure of the suppression of the matter power spectrum at the smallest scales due to the free-streaming of the non-cold dark matter component. We present the results on the fraction f ncdm of non-cold dark matter with respect to the total dark matter for different ranges of the non-cold dark matter masses. We find that the 2σ limits for non-cold dark matter particles with masses in the range 1–10 keV are f ncdm ≤0.29 (0.23) for fermions (bosons), and for masses in the 10–100 keV range they are f ncdm ≤0.43 (0.45), respectively.

  15. Olympic Health Legacy; Essentials for Lasting Development of Host City.

    Science.gov (United States)

    Lee, Young-Hee; Kim, Jung Moon

    2013-03-01

    The purpose of the Olympic Games should be to contribute to the social development by leaving behind economic, cultural and environmental legacies to the hosting region. While tangible examples such as venues are often recognized as representative legacies of the Olympics, intangible aspects such as the environment, culture, policy and human resources have been gaining in importance. The Olympic Games, at its most fundamental level, is a sporting event. Sports not only is closely related to the physical health, but is also instrumental to fostering mental health through inspiration. One of the most important sports legacies was the general change in the population's perception on sports and physical activities; due to such change, people were able to enjoy sports as part of healthy and active everyday life and benefit physically. However, compared to tangible legacies such as the facilities, social legacies such as the general health and their planning, execution and achievements are hard to monitor. Therefore, for the Olympics to leave behind socio-cultural legacies that contribute to the development of the hosting region, there must be a thorough business plan that takes into account region-specific purpose, and is divided into stages such as before, during and after the Games. Should the 2018 Winter Olympic Games hope to create continuing contribution to its hosting region, it must leave behind 'Health Legacies' that will enhance the happiness of the hosting region's population. To this end, establishment of region-specific purpose and systematic promotion of business via detailed analysis of precedents are a must. This article aim to review the health legacy endeavors of past host cities and suggest the appropriate forms of health legacy of 2018 Pyeongchang Winter Olympic and Paralympic Games.

  16. Dark matter substructure modelling and sensitivity of the Cherenkov Telescope Array to Galactic dark halos

    International Nuclear Information System (INIS)

    Huetten, M.; Combet, C.; Maurin, D.

    2016-07-01

    Hierarchical structure formation leads to a clumpy distribution of dark matter in the Milky Way. These clumps are possible targets to search for dark matter annihilation with present and future γ-ray instruments. Many uncertainties exist on the clump distribution, leading to disputed conclusions about the expected number of detectable clumps and the ensuing limits that can be obtained from non-detection. In this paper, we use the CLUMPY code to simulate thousands of skymaps for several clump distributions. This allows us to statistically assess the typical properties (mass, distance, angular size, luminosity) of the detectable clumps. Varying parameters of the clump distributions allows us to identify the key quantities to which the number of detectable clumps is the most sensitive. Focusing our analysis on two extreme clump configurations, yet consistent with results from numerical simulations, we revisit and compare various calculations made for the Fermi-LAT instrument, in terms of number of dark clumps expected and the angular power spectrum for the Galactic signal. We then focus on the prospects of detecting dark clumps with the future CTA instrument, for which we make a detailed sensitivity analysis using open-source CTA software. Based on a realistic scenario for the foreseen CTA extragalactic survey, and accounting for a post-trial sensitivity in the survey, we show that we obtain competitive and complementary limits to those based on long observation of a single bright dwarf spheroidal galaxy.

  17. Cassini: The Journey and the Legacy

    KAUST Repository

    Porco, Carolyn

    2018-01-15

    An international mission to explore, in depth, the Saturnian system ヨthe planet Saturn and its magnetosphere, glorious rings, and many moons- begun over 27 years ago. After seven years of development, the Cassini spacecraft was launched in 1997, spent seven years trekking to Saturn, and finally entered Saturn orbit in the summer of 2004. In the course of its 13 years orbiting this ring world, Cassini returned over 450 thousand images, 635GB of data, and invaluable insights on the solar systemメs most splendid and scientifically rich planetary system. In this lecture, Carolyn Porco, the leader of the imaging science team on NASA\\'s Cassini mission, will delight her audience with a retrospective look at what has been learned from this profoundly successful mission and what its final legacy is likely to be.

  18. Peter Waterman and his scientific legacy

    Science.gov (United States)

    Mishchenko, Michael I.; Kahnert, Michael; Mackowski, Daniel W.; Wriedt, Thomas

    2013-01-01

    Peter C. Waterman, a giant figure in the theory of electromagnetic, acoustic, and elastic wave scattering, passed away on 3 June, 2012. In view of his fundamental contributions, which to a large degree have guided the progress of these disciplines over the past five decades and affected profoundly the multifaceted research published in the Journal of Quantitative Spectroscopy and Radiative Transfer (JQSRT), we felt that it would be appropriate to solicit papers for a special issue of JQSRT commemorating Peter Waterman's scientific legacy. This initiative was endorsed by the JQSRT management and has resulted in a representative collection of high-quality papers which have undergone the same peer scrutiny as any paper submitted to JQSRT.

  19. The Phenomenal Legacy of Rabindranath Tagore

    Directory of Open Access Journals (Sweden)

    Ketaki Kushari Dyson

    2010-12-01

    Full Text Available Belonging to a generation of Bengalis who received Tagore as an acknowledged classic of their tradition, I grew up reading his books, listening to his music, watching his dance-dramas, and writing poetry under the inspiration of his words. This youthful appreciation of Tagore eventually led to a deeper understanding of his stature as an artist and thinker, but it was only when I entered Tagore studies in a more formal manner that I realized how truly spectacular his achievements were from an international perspective. Tagore was fortunate in that his time, place, and circumstances allowed him to give a good run to the natural versatility and fecundity of his genius. He has thereby secured a rich and diverse legacy for us, which tends to mean different things to different groups of people.

  20. Could Freemium Models Work for Legacy Newspapers?

    DEFF Research Database (Denmark)

    Holm, Anna B.

    2016-01-01

    The newspaper industry has long been looking for sustainable business models for their digital editions. One of their popular choices is the freemium business model based on free and premium content with a paywall. However, freemium has not yet lived up to the expectation of the industry and has ...... not secured the revenues that industry players hoped for. This article discusses a number of the main principles of the freemium strategy and tactics, and highlights the critical points for legacy newspaper organisations.......The newspaper industry has long been looking for sustainable business models for their digital editions. One of their popular choices is the freemium business model based on free and premium content with a paywall. However, freemium has not yet lived up to the expectation of the industry and has...

  1. Late forming dark matter in theories of neutrino dark energy

    International Nuclear Information System (INIS)

    Das, Subinoy; Weiner, Neal

    2011-01-01

    We study the possibility of late forming dark matter, where a scalar field, previously trapped in a metastable state by thermal or finite density effects, goes through a phase transition near the era matter-radiation equality and begins to oscillate about its true minimum. Such a theory is motivated generally if the dark energy is of a similar form, but has not yet made the transition to dark matter, and, in particular, arises automatically in recently considered theories of neutrino dark energy. If such a field comprises the present dark matter, the matter power spectrum typically shows a sharp break at small, presently nonlinear scales, below which power is highly suppressed and previously contained acoustic oscillations. If, instead, such a field forms a subdominant component of the total dark matter, such acoustic oscillations may imprint themselves in the linear regime.

  2. Adiabatic instability in coupled dark energy/dark matter models

    International Nuclear Information System (INIS)

    Bean, Rachel; Flanagan, Eanna E.; Trodden, Mark

    2008-01-01

    We consider theories in which there exists a nontrivial coupling between the dark matter sector and the sector responsible for the acceleration of the Universe. Such theories can possess an adiabatic regime in which the quintessence field always sits at the minimum of its effective potential, which is set by the local dark matter density. We show that if the coupling strength is much larger than gravitational, then the adiabatic regime is always subject to an instability. The instability, which can also be thought of as a type of Jeans instability, is characterized by a negative sound speed squared of an effective coupled dark matter/dark energy fluid, and results in the exponential growth of small scale modes. We discuss the role of the instability in specific coupled cold dark matter and mass varying neutrino models of dark energy and clarify for these theories the regimes in which the instability can be evaded due to nonadiabaticity or weak coupling.

  3. Unified dark energy-dark matter model with inverse quintessence

    International Nuclear Information System (INIS)

    Ansoldi, Stefano; Guendelman, Eduardo I.

    2013-01-01

    We consider a model where both dark energy and dark matter originate from the coupling of a scalar field with a non-canonical kinetic term to, both, a metric measure and a non-metric measure. An interacting dark energy/dark matter scenario can be obtained by introducing an additional scalar that can produce non constant vacuum energy and associated variations in dark matter. The phenomenology is most interesting when the kinetic term of the additional scalar field is ghost-type, since in this case the dark energy vanishes in the early universe and then grows with time. This constitutes an ''inverse quintessence scenario'', where the universe starts from a zero vacuum energy density state, instead of approaching it in the future

  4. Nonlocal astrophysics dark matter, dark energy and physical vacuum

    CERN Document Server

    Alexeev, Boris V

    2017-01-01

    Non-Local Astrophysics: Dark Matter, Dark Energy and Physical Vacuum highlights the most significant features of non-local theory, a highly effective tool for solving many physical problems in areas where classical local theory runs into difficulties. The book provides the fundamental science behind new non-local astrophysics, discussing non-local kinetic and generalized hydrodynamic equations, non-local parameters in several physical systems, dark matter, dark energy, black holes and gravitational waves. Devoted to the solution of astrophysical problems from the position of non-local physics Provides a solution for dark matter and dark energy Discusses cosmological aspects of the theory of non-local physics Includes a solution for the problem of the Hubble Universe expansion, and of the dependence of the orbital velocity from the center of gravity

  5. Dearth of dark matter or massive dark halo? Mass-shape-anisotropy degeneracies revealed by NMAGIC dynamical models of the elliptical galaxy NGC 3379

    NARCIS (Netherlands)

    De Lorenzi, F.; Gerhard, O.; Coccato, L.; Arnaboldi, M.; Capaccioli, M.; Douglas, N. G.; Freeman, K. C.; Kuijken, K.; Merrifield, M. R.; Napolitano, N. R.; Noordermeer, E.; Romanowsky, A. J.; Debattista, V. P.

    2009-01-01

    Recent results from the Planetary Nebula Spectrograph (PNS) survey have revealed a rapidly falling velocity dispersion profile in the nearby elliptical galaxy NGC 3379, casting doubts on whether this intermediate-luminosity galaxy has the kind of dark matter (DM) halo expected in A cold dark matter

  6. Managing a project's legacy: implications for organizations and project management

    Science.gov (United States)

    Cooper, Lynne P.; Hecht, Michael H.; Majchrzak, Ann

    2003-01-01

    Organizations that rely on projects to implement their products must find effective mechanisms for propagating lessons learned on one project throughout the organization. A broad view of what constitutes a project's 'legacy' is presented that includes not just the design products and leftover parts, but new processes, relationships, technology, skills, planning data, and performance metrics. Based on research evaluating knowledge reuse in innovative contexts, this paper presents an approach to project legacy management that focuses on collecting and using legacy knowledge to promote organizational learning and effective reuse, while addressing factors of post-project responsibility, information obsolescence, and the importance of ancillary contextual information. .

  7. Examining the evidence for dynamical dark energy.

    Science.gov (United States)

    Zhao, Gong-Bo; Crittenden, Robert G; Pogosian, Levon; Zhang, Xinmin

    2012-10-26

    We apply a new nonparametric Bayesian method for reconstructing the evolution history of the equation of state w of dark energy, based on applying a correlated prior for w(z), to a collection of cosmological data. We combine the latest supernova (SNLS 3 year or Union 2.1), cosmic microwave background, redshift space distortion, and the baryonic acoustic oscillation measurements (including BOSS, WiggleZ, and 6dF) and find that the cosmological constant appears consistent with current data, but that a dynamical dark energy model which evolves from w-1 at higher redshift is mildly favored. Estimates of the Bayesian evidence show little preference between the cosmological constant model and the dynamical model for a range of correlated prior choices. Looking towards future data, we find that the best fit models for current data could be well distinguished from the ΛCDM model by observations such as Planck and Euclid-like surveys.

  8. Current constraints on interacting holographic dark energy

    International Nuclear Information System (INIS)

    Wu Qiang; Gong Yungui; Wang Anzhong; Alcaniz, J.S.

    2008-01-01

    Although there is mounting observational evidence that the cosmic expansion is undergoing a late-time acceleration, the physical mechanism behind such a phenomenon is yet unknown. In this Letter, we investigate a holographic dark energy (HDE) model with interaction between the components of the dark sector in the light of current cosmological observations. We use both the new gold sample of 182 type Ia supernovae (SNe Ia) and the 192 SNe Ia ESSENCE data, the baryon acoustic oscillation measurement from the Sloan Digital Sky Survey and the shift parameter from the three-year Wilkinson Microwave Anisotropy Probe data. In agreement with previous results, we show that these observations suggest a very weak coupling or even a noninteracting HDE. The phantom crossing behavior in the context of these scenarios is also briefly discussed

  9. Sourcing dark matter and dark energy from α-attractors

    International Nuclear Information System (INIS)

    Mishra, Swagat S.; Sahni, Varun; Shtanov, Yuri

    2017-01-01

    In [1], Kallosh and Linde drew attention to a new family of superconformal inflationary potentials, subsequently called α-attractors [2]. The α-attractor family can interpolate between a large class of inflationary models. It also has an important theoretical underpinning within the framework of supergravity. We demonstrate that the α-attractors have an even wider appeal since they may describe dark matter and perhaps even dark energy. The dark matter associated with the α-attractors, which we call α-dark matter (αDM), shares many of the attractive features of fuzzy dark matter, with V (φ) = ½ m 2 φ 2 , while having none of its drawbacks. Like fuzzy dark matter, αDM can have a large Jeans length which could resolve the cusp-core and substructure problems faced by standard cold dark matter. αDM also has an appealing tracker property which enables it to converge to the late-time dark matter asymptote, ( w ) ≅ 0, from a wide range of initial conditions. It thus avoids the enormous fine-tuning problems faced by the m 2 φ 2 potential in describing dark matter.

  10. Legacy Interventions With Patients with Co-Occurring Disorders: Legacy Definitions, Life Satisfaction, and Self-Efficacy.

    Science.gov (United States)

    Franklin, Felina C; Cheung, Monit

    2017-12-06

    Individuals with co-occurring disorders tend to avoid interaction with others. To instill hope, legacy intervention aims to highlight past experiences while managing life stressors for a positive outlook. Participants take part in legacy activities-crafting tangible projects and recording one's life events-in order to actualize a personal sense of legacy. This pre-posttest research tested whether legacy intervention in a partial hospital program (PHP) on reframing past experiences through creative activities could increase life satisfaction and self-efficacy among adults with co-occurring substance misuse and mental health symptoms. Eighty consented patients with co-occurring disorders were randomly assigned to two groups with 62 participants continuing: 37 in legacy intervention (LI) and 25 in partial hospital program only (PHP-only). LI participants were engaged in both PHP and legacy activities. Ten group sessions were held over the course of five weeks for cohorts of 10-15 adult patients in each intervention. Sense of legacy was measured to ensure that LI patients received the appropriate legacy dosage. With RANOVA analyses between and among three time points, life satisfaction was significantly higher in the LI group with group interaction effect over time. In terms of self-efficacy, both groups showed positive changes but no significant difference could be found between the two groups over time and the interaction (time X group) effect was not significant. The legacy definitions gathered from the LI group were consistent with existing literature and showed three additional themes: children's involvement, concreteness, and life continuation after death.

  11. Dark Martian Dunes

    Science.gov (United States)

    2005-01-01

    30 June 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows dark, windblown sand dunes in a crater in the Hesperia region of Mars. The steepest slopes on the dunes -- their slipfaces -- point toward the south-southwest, indicating that the winds responsible for the dunes blew from the north-northeast (top/upper right). Location near: 12.4oS, 236.5oW Image width: 3 km (1.9 mi) Illumination from: upper left Season Southern Spring

  12. Dark Polar Dunes

    Science.gov (United States)

    2005-01-01

    20 January 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image, acquired during northern summer in December 2004, shows dark, windblown sand dunes in the north polar region of Mars. A vast sea of sand dunes nearly surrounds the north polar cap. These landforms are located near 80.3oN, 144.1oW. Light-toned features in the image are exposures of the substrate that underlies the dune field. The image covers an area about 3 km (1.9 mi) wide and is illuminated by sunlight from the lower left.

  13. Dark energy constraints from galaxy cluster peculiar velocities

    International Nuclear Information System (INIS)

    Bhattacharya, Suman; Kosowsky, Arthur

    2008-01-01

    Future multifrequency microwave background experiments with arcminute resolution and micro-Kelvin temperature sensitivity will be able to detect the kinetic Sunyaev-Zeldovich effect, providing a way to measure radial peculiar velocities of massive galaxy clusters. We show that cluster peculiar velocities have the potential to constrain several dark energy parameters. We compare three velocity statistics (the distribution of radial velocities, the mean pairwise streaming velocity, and the velocity correlation function) and analyze the relative merits of these statistics in constraining dark energy parameters. Of the three statistics, mean pairwise streaming velocity provides constraints that are least sensitive to velocity errors: the constraints on parameters degrade only by a factor of 2 when the random error is increased from 100 to 500 km/s. We also compare cluster velocities with other dark energy probes proposed in the Dark Energy Task Force report. For cluster velocity measurements with realistic priors, the eventual constraints on the dark energy density, the dark energy equation of state and its evolution are comparable to constraints from supernovae measurements, and better than cluster counts and baryon acoustic oscillations; adding velocity to other dark energy probes improves constraints on the figure of merit by more than a factor of 2. For upcoming Sunyaev-Zeldovich galaxy cluster surveys, even velocity measurements with errors as large as 1000 km/s will substantially improve the cosmological constraints compared to using the cluster number density alone.

  14. Dark Matter: Looking for WIMPs in the Galactic Halo

    International Nuclear Information System (INIS)

    Akerib, Daniel S.

    2006-01-01

    Overwhelming observational evidence indicates that most of the matter in the Universe consists of non-baryonic dark matter. One possibility is that the dark matter is Weakly-Interacting Massive Particles (WIMPs) that were produced in the early Universe. These relics could comprise the Milky Way's dark halo and provide evidence for new particle physics, such as Supersymmetry. After reviewing some of the evidence for dark matter and the WIMP hypothesis, I will describe the strategy for searching for WIMPs, along with a survey of the current status and outlook. In particular, dark matter searches have begun to explore the region of parameter space where SUSY particles could provide dark matter candidates. I will also mention some of the recent theoretical work on dark matter candidates which is being done in anticipation of the turn-on of the LHC and as part of the active R and D on the ILC. Finally, a vigorous detector development program promises significant advances in WIMP sensitivity in the coming years

  15. Dark Energy Studies with LSST Image Simulations, Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, John Russell [Purdue Univ., West Lafayette, IN (United States)

    2016-07-26

    This grant funded the development and dissemination of the Photon Simulator (PhoSim) for the purpose of studying dark energy at high precision with the upcoming Large Synoptic Survey Telescope (LSST) astronomical survey. The work was in collaboration with the LSST Dark Energy Science Collaboration (DESC). Several detailed physics improvements were made in the optics, atmosphere, and sensor, a number of validation studies were performed, and a significant number of usability features were implemented. Future work in DESC will use PhoSim as the image simulation tool for data challenges used by the analysis groups.

  16. Dark matter in the universe

    International Nuclear Information System (INIS)

    Opher, Reuven

    2001-01-01

    We treat here the problem of dark matter in galaxies. Recent articles seem to imply that we are entering into the precision era of cosmology, implying that all of the basic physics of cosmology is known. However, we show here that recent observations question the pillar of the standard model: the presence of nonbaryonic 'dark matter' in galaxies. Using Newton's law of gravitation, observations indicate that most of the matter in galaxies in invisible or dark. From the observed abundances of light elements, dark matter in galaxies must be primarily nonbaryonic. The standard model and its problems in explaining nonbaryonic dark matter will first be discussed. This will be followed by a discussion of a modification of Newton's law of gravitation to explain dark matter in galaxies. (author)

  17. Quantum vacuum and dark matter

    CERN Document Server

    Hajdukovic, Dragan Slavkov

    2012-01-01

    Recently, the gravitational polarization of the quantum vacuum was proposed as alternative to the dark matter paradigm. In the present paper we consider four benchmark measurements: the universality of the central surface density of galaxy dark matter haloes, the cored dark matter haloes in dwarf spheroidal galaxies, the non-existence of dark disks in spiral galaxies and distribution of dark matter after collision of clusters of galaxies (the Bullet cluster is a famous example). Only some of these phenomena (but not all of them) can (in principle) be explained by the dark matter and the theories of modified gravity. However, we argue that the framework of the gravitational polarization of the quantum vacuum allows the understanding of the totality of these phenomena.

  18. Direct search for dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Jonghee; /Fermilab

    2009-12-01

    Dark matter is hypothetical matter which does not interact with electromagnetic radiation. The existence of dark matter is only inferred from gravitational effects of astrophysical observations to explain the missing mass component of the Universe. Weakly Interacting Massive Particles are currently the most popular candidate to explain the missing mass component. I review the current status of experimental searches of dark matter through direct detection using terrestrial detectors.

  19. Astrophysical probes of dark matter

    Science.gov (United States)

    Hurst, Travis J.

    In the ACDM model,≈ 26% of the matter-energy content of the Universe is in the form of an unidentified Cold Dark Matter. Observations indicate that the Dark Matter is a new exotic particle not accounted for in the Standard Model of particle physics. Identifying the Dark Matter particle is one of the most pressing problems in cosmology and particle physics. In this thesis we investigate several possible astrophysical signatures of Dark Matter: Dark Matter annihilations in cold White Dwarfs provide a source of luminosity that could halt their cooling. This effect can be used to constrain the Dark Matter density local to the White Dwarf. In the case of the coldest White Dwarf in a Globular Cluster, a constraint on the maximum Dark Matter content is derived. Globular Clusters do not appear to have Dark Matter halos today, but could have possessed them in the past. We investigate whether Globular Clusters could have lost their halos through multi-body gravitational interactions--we find that this scenario is unlikely. Finally, we explore the effects of Asymmetric Dark Matter on stellar evolution. Asymmetric Dark Matter can alter the transport of energy in the cores of stars. We show that this has potentially observable effects on low mass Main Sequence and post-Main Sequence stars. Our main conclusion is that astrophysical observations can potentially rule out some Dark Matter models. On the other hand, if the properties of the Dark Matter particle become known, then its astrophysical effects must be taken into account when evaluating observations.

  20. Caustic rings of dark matter

    International Nuclear Information System (INIS)

    Sikivie, P.

    1997-01-01

    It is shown that the infall of collisionless dark matter onto isolated galaxies produce a series of caustic rings in the halo dark matter distribution. The properties of these caustics are investigated. It is found in particular that the density profile of the caustic behaves as the inverse distance to the ring. Bumps in the rotation curve of NGC 3198 are interpreted as due to caustic rings of dark matter

  1. Methods for Finding Legacy Wells in Residential and Commercial Areas

    Energy Technology Data Exchange (ETDEWEB)

    Hammack, Richard [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Veloski, Garret [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States)

    2016-06-06

    The objective of this study was to locate legacy wells in Versailles Borough so that the Pennsylvania Department of Environmental Protection could mitigate dangerous CH4 concentrations in the community by venting or plugging leaking wells.

  2. Sport and exercise medicine and the Olympic health legacy

    Directory of Open Access Journals (Sweden)

    Tew Garry A

    2012-07-01

    Full Text Available Abstract London 2012 is the first Olympic and Paralympic Games to explicitly try and develop socioeconomic legacies for which success indicators are specified - the highest profile of which was to deliver a health legacy by getting two million more people more active by 2012. This editorial highlights how specialists in Sport and Exercise Medicine can contribute towards increasing physical activity participation in the UK, as well as how the National Centre for Sport and Exercise Medicine might be a useful vehicle for delivering an Olympic health legacy. Key challenges are also discussed such as acquisition of funding to support new physical activity initiatives, appropriate allocation of resources, and how to assess the impact of legacy initiatives.

  3. An assessment of mine legacies and how to prevent them

    DEFF Research Database (Denmark)

    Pacheco Cueva, Vladimir

    of AMD is felt well beyond the mining district and the costs of prevention and remediation were found to be significant. Apart from environmental legacies, the mine also left a number of socio-economic legacies including: limited access to non-polluted water that results in San Sebastian residents...... devoting a high proportion of their income in obtaining water, lost opportunities due to the cessation of mining, uncertain land tenure situation and increasing growth of ASGM activities that exacerbate already existing environmental pollution due to use of mercury. The study also found that the state......The study seeks to enrich the growing literature on mine legacies by examining a case study of a small abandoned mine in Latin America. Using a combination of Rapid Rural Appraisal and secondary source analysis, this study assessed some of the most damaging legacies of the San Sebastian mine...

  4. Legacy System Wrapping for Department of Defense Information System Modernization

    National Research Council Canada - National Science Library

    Jordan, Kathleen

    1995-01-01

    This document explains the activities, benefits, problems, and issues in using the object-oriented technique of software wrapping to support the migration from legacy information systems to modernized systems...

  5. The DarkSide project

    Energy Technology Data Exchange (ETDEWEB)

    Agnes, P.; Agostino, L.; Albuquerque, Ivone Freire Da Mota; Alexander, Thomas R.; Alton, A.; Arisaka, K.; Back, Henning O.; Baldin, B.; Biery, K.; Bonfini, G.; Bossa, M.; Bottino, Bianca; Brigatti, A.; Brodsky, J.; Budano, F.; Bussino, Severino; Cadeddu, Matteo; Cadonati, L.; Cadoni, M.; Calaprice, F.; Canci, N.; Candela, A.; Cao, H.; Cariello, M.; Carlini, Macro; Catalanotti, Sergio; Cavalcante, P.; Chepurnov, A.; Cocco, A. G.; Covone, G.; Crippa, L.; D' Angelo, D.; D' Incecco, M.; Davini, S.; De Cecco, Sandro; De Deo, M.; De Vincenzi, Mario; Derbin, A.; Devoto, A.; Di Eusanio, F.; Di Pietro, Giuseppe; Edkins, E.; Empl, Anton; Fan, A.; Fiorillo, G.; Fomenko, K.; Forster, G.; Franco, D.; Gabriele, F.; Galbiati, C.; Giganti, C.; Goretti, A.; Granato, Francesco; Grandi, L.; Gromov, M.; Guan, M. Y.; Guardincerri, Y.; Hackett, B.; Herner, K.; Hungerford, Edward; Ianni, Al.; Ianni, An.; James, I.; Jollet, C.; Keeter, K.; Kendziora, C.; Kobychev, V.; Koh, G.; Korablev, D.; Korga, G.; Kubankin, Alexander; Li, X.; Lissia, M.; Lombardi, P.; Luitz, S.; Ma, Y. Q.; Machulin, I.; Mandarano, A.; Mari, S. M.; Maricic, J.; Marini, L.; Martoff, J.; Meregaglia, A.; Meyers, P. D.; Miletic, T.; Milincic, R.; Montanari, D.; Monte, Alissa; Montuschi, M.; Monzani, M. E.; Mosteiro, P.; Mount, B.; Muratova, V.; Musico, P.; Napolitano, James; Nelson, A.; Odrowski, S.; Orsini, M.; Ortica, F.; Pagani, L.; Pallavicini, Marco; Pantic, E.; Parmeggiano, S.; Pelczar, K.; Pelliccia, N.; Perasso, S.; Pocar, A.; Pordes, S.; Pugachev, D.; Qian, H.; Randle, K.; Ranucci, Gioacchino; Razeto, A.; Reinhold, B.; Renshaw, Andrew; Romani, A.; Rossi, B.; Rossi, N.; Rountree, S. D.; Sablone, D.; Saggese, P.; Saldanha, R.; Sands, W.; Sangiorgio, Samuele; Savarese, Claudio; Segreto, E.; Semenov, D.; Shields, E.; Singh, Parth; Skorokhvatov, Mikhail; Smirnov, Oleg; Sotnikov, Albert; Stanford, Chris; Suvorov, Yura; Tartaglia, Roberto; Tatarowicz, John; Testera, Gemma; Tonazzo, Alessandra; Trinchese, P.; Unzhakov, Eugenii; Vishneva, Alina; Vogelaar, R. B.; Wada, Masayuki; Walker, Susan E.; Wang, H.; Wang, Y.; Watson, A. W.; Westerdale, S.; Wilhelmi, James; Wojcik, M.; Xiang, Xin; Xu, Jingke; Yang, C. G.; Yoo, J.; Zavatarelli, Sandra; Zec, Adam; Zhong, W. L.; Zhu, Chengliang; Zuzel, G.

    2016-02-01

    DarkSide is a graded experimental project based on radiopure argon, and is now, and will be, used in direct dark matter searches. The present DarkSide-50 detector, operating at the Gran Sasso National Laboratory, is a dual-phase, 50 kg, liquid argon time-projection-chamber surrounded by an active liquid scintillator veto. It is designed to be background free in 3 years of operation. DS-50 performances, when filled with atmospheric argon, are reported. However DS-50 filled with underground argon, shows impressive reduction of the 39Ar isotope. The application of this powerful technology in a future generation of the DarkSide program is discussed.

  6. Kaluza-Klein dark matter

    CERN Document Server

    Cheng, H C; Matchev, K T; Cheng, Hsin-Chia; Feng, Jonathan L; Matchev, Konstantin T.

    2002-01-01

    We propose that cold dark matter is made of Kaluza-Klein particles and explore avenues for its detection. The lightest Kaluza-Klein state is an excellent dark matter candidate if standard model particles propagate in extra dimensions and Kaluza-Klein parity is conserved. We consider Kaluza-Klein gauge bosons. In sharp contrast to the case of supersymmetric dark matter, these annihilate to hard positrons, neutrinos and photons with unsuppressed rates. Direct detection signals are also promising. These conclusions are generic to bosonic dark matter candidates.

  7. Supersymmetric dark matter: Indirect detection

    International Nuclear Information System (INIS)

    Bergstroem, L.

    2000-01-01

    Dark matter detection experiments are improving to the point where they can detect or restrict the primary particle physics candidates for non baryonic dark matter. The methods for detection are usually categorized as direct, i.e., searching for signals caused by passage of dark matter particles in terrestrial detectors, or indirect. Indirect detection methods include searching for antimatter and gamma rays, in particular gamma ray lines, in cosmic rays and high-energy neutrinos from the centre of the Earth or Sun caused by accretion and annihilation of dark matter particles. A review is given of recent progress in indirect detection, both on the theoretical and experimental side

  8. Dark matter. A light move

    International Nuclear Information System (INIS)

    Redondo, Javier; Doebrich, Babette

    2013-11-01

    This proceedings contribution reports from the workshop Dark Matter - a light move, held at DESY in Hamburg in June 2013. Dark Matter particle candidates span a huge parameter range. In particular, well motivated candidates exist also in the sub-eV mass region, for example the axion. Whilst a plethora of searches for rather heavy Dark Matter particles exists, there are only very few experiments aimed at direct detection of sub-eV Dark Matter to this date. The aim of our workshop was to discuss if and how this could be changed in the near future.

  9. Dark matter. A light move

    Energy Technology Data Exchange (ETDEWEB)

    Redondo, Javier [Muenchen Univ. (Germany). Arnold Sommerfeld Center; Max-Planck-Institut fuer Physik, Muenchen (Germany); Doebrich, Babette [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2013-11-15

    This proceedings contribution reports from the workshop Dark Matter - a light move, held at DESY in Hamburg in June 2013. Dark Matter particle candidates span a huge parameter range. In particular, well motivated candidates exist also in the sub-eV mass region, for example the axion. Whilst a plethora of searches for rather heavy Dark Matter particles exists, there are only very few experiments aimed at direct detection of sub-eV Dark Matter to this date. The aim of our workshop was to discuss if and how this could be changed in the near future.

  10. Baryonic dark matter

    International Nuclear Information System (INIS)

    Lynden-Bell, D.; Gilmore, G.

    1990-01-01

    Dark matter, first definitely found in the large clusters of galaxies, is now known to be dominant mass in the outer parts of galaxies. All the mass definitely deduced could be made up of baryons, and this would fit well with the requirements of nucleosynthesis in a big bang of small Ω B . However, if inflation is the explanation of the expansion and large scale homogeneity of the universe and of baryon synthesis, and if the universe did not have an infinite extent at the big bang, then Ω should be minutely greater than unity. It is commonly hypothesized that most mass is composed of some unknown, non-baryonic form. This book first discusses the known forms, comets, planets, brown dwarfs, stars, gas, galaxies and Lyman α clouds in which baryons are known to exist. Limits on the amount of dark matter in baryonic form are discussed in the context of the big bang. Inhomogeneities of the right type alleviate the difficulties associated with Ω B = 1 cosmological nucleosynthesis

  11. Dark Matter remains obscure

    CERN Multimedia

    Fabio Capello

    2011-01-01

    It is one of the hidden secrets that literally surround the Universe. Experiments have shown no result so far because trying to capture particles that do not seem to interact with ordinary matter is no trivial exercise. The OSQAR experiment at CERN is dedicated to the search for axions, one of the candidates for Dark Matter. For its difficult challenge, OSQAR counts on one of the world’s most powerful magnets borrowed from the LHC. In a recent publication, the OSQAR collaboration was able to confirm that no axion signal appears out of the background. In other words: the quest is still on.   The OSQAR experiment installed in the SM18 hall. (Photo by F. Capello) The OSQAR “Light Shining Through a Wall” experiment was officially launched in 2007 with the aim of detecting axions, that is, particles that might be the main components of Dark Matter. OSQAR uses the powerful LHC dipole magnet to intensify the predicted photon-axion conversions in the presence of strong m...

  12. Olympic Health Legacy; Essentials for Lasting Development of Host City

    Science.gov (United States)

    Lee, Young-Hee; Kim, Jung Moon

    2013-01-01

    The purpose of the Olympic Games should be to contribute to the social development by leaving behind economic, cultural and environmental legacies to the hosting region. While tangible examples such as venues are often recognized as representative legacies of the Olympics, intangible aspects such as the environment, culture, policy and human resources have been gaining in importance. The Olympic Games, at its most fundamental level, is a sporting event. Sports not only is closely related to the physical health, but is also instrumental to fostering mental health through inspiration. One of the most important sports legacies was the general change in the population’s perception on sports and physical activities; due to such change, people were able to enjoy sports as part of healthy and active everyday life and benefit physically. However, compared to tangible legacies such as the facilities, social legacies such as the general health and their planning, execution and achievements are hard to monitor. Therefore, for the Olympics to leave behind socio-cultural legacies that contribute to the development of the hosting region, there must be a thorough business plan that takes into account region-specific purpose, and is divided into stages such as before, during and after the Games. Should the 2018 Winter Olympic Games hope to create continuing contribution to its hosting region, it must leave behind ‘Health Legacies’ that will enhance the happiness of the hosting region’s population. To this end, establishment of region-specific purpose and systematic promotion of business via detailed analysis of precedents are a must. This article aim to review the health legacy endeavors of past host cities and suggest the appropriate forms of health legacy of 2018 Pyeongchang Winter Olympic and Paralympic Games. PMID:26064832

  13. Dark fluid: A complex scalar field to unify dark energy and dark matter

    International Nuclear Information System (INIS)

    Arbey, Alexandre

    2006-01-01

    In this article, we examine a model which proposes a common explanation for the presence of additional attractive gravitational effects - generally considered to be due to dark matter - in galaxies and in clusters, and for the presence of a repulsive effect at cosmological scales - generally taken as an indication of the presence of dark energy. We therefore consider the behavior of a so-called dark fluid based on a complex scalar field with a conserved U(1)-charge and associated to a specific potential, and show that it can at the same time account for dark matter in galaxies and in clusters, and agree with the cosmological observations and constraints on dark energy and dark matter

  14. The Dearth of z ∼ 10 Galaxies in All HST Legacy Fields—The Rapid Evolution of the Galaxy Population in the First 500 Myr

    Science.gov (United States)

    Oesch, P. A.; Bouwens, R. J.; Illingworth, G. D.; Labbé, I.; Stefanon, M.

    2018-03-01

    We present an analysis of all prime HST legacy fields spanning >800 arcmin2 in the search for z ∼ 10 galaxy candidates and the study of their UV luminosity function (LF). In particular, we present new z ∼ 10 candidates selected from the full Hubble Frontier Field (HFF) data set. Despite the addition of these new fields, we find a low abundance of z ∼ 10 candidates with only nine reliable sources identified in all prime HST data sets that include the HUDF09/12, the HUDF/XDF, all of the CANDELS fields, and now the HFF survey. Based on this comprehensive search, we find that the UV luminosity function decreases by one order of magnitude from z ∼ 8 to z ∼ 10 over a four-magnitude range. This also implies a decrease of the cosmic star formation rate density by an order of magnitude within 170 Myr from z ∼ 8 to z ∼ 10. We show that this accelerated evolution compared to lower redshift can entirely be explained by the fast build up of the dark matter halo mass function at z > 8. Consequently, the predicted UV LFs from several models of galaxy formation are in good agreement with this observed trend, even though the measured UV LF lies at the low end of model predictions. The difference is generally still consistent within the Poisson and cosmic variance uncertainties. We discuss the implications of these results in light of the upcoming James Webb Space Telescope mission, which is poised to find much larger samples of z ∼ 10 galaxies as well as their progenitors at less than 400 Myr after the big bang. Based on data obtained with the Hubble Space Telescope operated by AURA, Inc. for NASA under contract NAS5-26555.

  15. Is Self-Interacting Dark Matter Undergoing Dark Fusion?

    Energy Technology Data Exchange (ETDEWEB)

    McDermott, Samuel D.

    2017-11-02

    We suggest that two-to-two dark matter fusion may be the relaxation process that resolves the small-scale structure problems of the cold collisionless dark matter paradigm. In order for the fusion cross section to scale correctly across many decades of astrophysical masses from dwarf galaxies to galaxy clusters, we require the fractional binding energy released to be greater than v^n ~ [10^{-(2-3)}]^n, where n=1,2 depends on local dark sector chemistry. The size of the dark-sector interaction cross sections must be sigma ~ 0.1-1 barn, moderately larger than for Standard Model deuteron fusion, indicating a dark nuclear scale Lambda ~ O(100 MeV). Dark fusion firmly predicts constant sigma v below the characteristic velocities of galaxy clusters. Observations of the inner structure of galaxy groups with velocity dispersion of several hundred kilometer per second, of which a handful have been identified, could differentiate dark fusion from a dark photon model.

  16. DarkSUSY: Computing Supersymmetric Dark Matter Properties Numerically

    Energy Technology Data Exchange (ETDEWEB)

    Gondolo, P.

    2004-07-16

    The question of the nature of the dark matter in the Universe remains one of the most outstanding unsolved problems in basic science. One of the best motivated particle physics candidates is the lightest supersymmetric particle, assumed to be the lightest neutralino - a linear combination of the supersymmetric partners of the photon, the Z boson and neutral scalar Higgs particles. Here we describe DarkSUSY, a publicly-available advanced numerical package for neutralino dark matter calculations. In DarkSUSY one can compute the neutralino density in the Universe today using precision methods which include resonances, pair production thresholds and coannihilations. Masses and mixings of supersymmetric particles can be computed within DarkSUSY or with the help of external programs such as FeynHiggs, ISASUGRA and SUSPECT. Accelerator bounds can be checked to identify viable dark matter candidates. DarkSUSY also computes a large variety of astrophysical signals from neutralino dark matter, such as direct detection in low-background counting experiments and indirect detection through antiprotons, antideuterons, gamma-rays and positrons from the Galactic halo or high-energy neutrinos from the center of the Earth or of the Sun. Here we describe the physics behind the package. A detailed manual will be provided with the computer package.

  17. Turning off the lights: How dark is dark matter?

    International Nuclear Information System (INIS)

    McDermott, Samuel D.; Yu Haibo; Zurek, Kathryn M.

    2011-01-01

    We consider current observational constraints on the electromagnetic charge of dark matter. The velocity dependence of the scattering cross section through the photon gives rise to qualitatively different constraints than standard dark matter scattering through massive force carriers. In particular, recombination epoch observations of dark matter density perturbations require that ε, the ratio of the dark matter to electronic charge, is less than 10 -6 for m X =1 GeV, rising to ε -4 for m X =10 TeV. Though naively one would expect that dark matter carrying a charge well below this constraint could still give rise to large scattering in current direct detection experiments, we show that charged dark matter particles that could be detected with upcoming experiments are expected to be evacuated from the Galactic disk by the Galactic magnetic fields and supernova shock waves and hence will not give rise to a signal. Thus dark matter with a small charge is likely not a source of a signal in current or upcoming dark matter direct detection experiments.

  18. Correlation between dark matter and dark radiation in string compactifications

    International Nuclear Information System (INIS)

    Allahverdi, Rouzbeh; Cicoli, Michele; Dutta, Bhaskar; Sinha, Kuver

    2014-01-01

    Reheating in string compactifications is generically driven by the decay of the lightest modulus which produces Standard Model particles, dark matter and light hidden sector degrees of freedom that behave as dark radiation. This common origin allows us to find an interesting correlation between dark matter and dark radiation. By combining present upper bounds on the effective number of neutrino species N eff with lower bounds on the reheating temperature as a function of the dark matter mass m DM from Fermi data, we obtain strong constraints on the (N eff , m DM )-plane. Most of the allowed region in this plane corresponds to non-thermal scenarios with Higgsino-like dark matter. Thermal dark matter can be allowed only if N eff tends to its Standard Model value. We show that the above situation is realised in models with perturbative moduli stabilisation where the production of dark radiation is unavoidable since bulk closed string axions remain light and do not get eaten up by anomalous U(1)s

  19. Residual non-Abelian dark matter and dark radiation

    Directory of Open Access Journals (Sweden)

    P. Ko

    2017-05-01

    Full Text Available We propose a novel particle physics model in which vector dark matter (VDM and dark radiation (DR originate from the same non-Abelian dark sector. We show an illustrating example where dark SU(3 is spontaneously broken into SU(2 subgroup by the nonzero vacuum expectation value (VEV of a complex scalar in fundamental representation of SU(3. The massless gauge bosons associated with the residual unbroken SU(2 constitute DR and help to relieve the tension in Hubble constant measurements between Planck and Hubble Space Telescope. In the meantime, massive dark gauge bosons associated with the broken generators are VDM candidates. Intrinsically, this non-Abelian VDM can interact with non-Abelian DR in the cosmic background, which results in a suppressed matter power spectrum and leads to a smaller σ8 for structure formation.

  20. The interaction between dark energy and dark matter

    International Nuclear Information System (INIS)

    He Jianhua; Wang Bin

    2010-01-01

    In this review we first present a general formalism to study the growth of dark matter perturbations in the presence of interactions between dark matter(DM) and dark energy(DE). We also study the signature of such interaction on the temperature anisotropies of the large scale cosmic microwave background (CMB). We find that the effect of such interaction has significant signature on both the growth of dark matter structure and the late Integrated Sachs Wolfe effect(ISW). We further discuss the potential possibility to detect the coupling by cross-correlating CMB maps with tracers of the large scale structure. We finally confront this interacting model with WMAP 5-year data as well as other data sets. We find that in the 1σ range, the constrained coupling between dark sectors can solve the coincidence problem.

  1. Neutrino signals from dark matter

    Science.gov (United States)

    Erkoca, Arif Emre

    Large-scale neutrino telescopes will be powerful tools to observe multitude of mysterious phenomena happening in the Universe. The dark matter puzzle is listed as one of them. In this study, indirect detection of dark matter via neutrino signals is presented. The upward muon, the contained muon and the hadronic shower fluxes are calculated, assuming annihilation/decay of the dark matter in the core of the astrophysical objects and in the Galactic center. Direct neutrino production and secondary neutrino production from the decay of Standard Model particles produced in the annihilation/decay of dark matter are studied. The results are contrasted to the ones previously obtained in the literature, illustrating the importance of properly treating muon propagation and energy loss for the upward muon flux. The dependence of the dark matter signals on the density profile, the dark matter mass and the detector threshold are discussed. Different dark matter models (gravitino, Kaluza-Klein and leptophilic) which can account for recent observations of some indirect searches are analyzed regarding their detection in the kilometer size neutrino detectors in the near future. Muon and shower rates and the minimum observation times in order to reach 2sigma detection significance are evaluated, with the result suggesting that the optimum cone half angles chosen about the Galactic center are about 10° (50°) for the muon (shower) events. A detailed analysis shows that for the annihilating dark matter models such as the leptophilic and Kaluza-Klein models, upward and contained muon as well as showers yield promising signals for dark matter detection in just a few years of observation, whereas for decaying dark matter models, the same observation times can only be reached with showers. The analytical results for the final fluxes are also obtained as well as parametric forms for the muon and shower fluxes for the dark matter models considered in this study.

  2. Exploring a hidden fermionic dark sector

    Indian Academy of Sciences (India)

    2017-10-09

    Oct 9, 2017 ... Fermions in the dark sector also carry a global U ( 1 ) H charge while the gauge bosons and dark scalar do not have any global U ( 1 ) H charge. The lightest fermion in dark sector can serve as a potential dark matter candidate. We investigate whether the proposed dark matter candidate can explain indirect ...

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

    International Nuclear Information System (INIS)

    Chen, Xi; Gan, Cong-Gui; Shen, Zhi-Qiang; Ellingsen, Simon P.; Titmarsh, Anita; He, Jin-Hua

    2013-01-01

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

  4. SPHEREx: Probing the Physics of Inflation with an All-Sky Spectroscopic Galaxy Survey

    Science.gov (United States)

    Dore, Olivier; SPHEREx Science Team

    2018-01-01

    SPHEREx, a mission in NASA's Medium Explorer (MIDEX) program that was selected for Phase A in August 2017, is an all-sky survey satellite designed to address all three science goals in NASA’s astrophysics division: probe the origin and destiny of our Universe; explore whether planets around other stars could harbor life; and explore the origin and evolution of galaxies. These themes are addressed by a single survey, with a single instrument.In this poster, we describe how SPHEREx can probe the physics of inflationary non-Gaussianity by measuring large-scale structure with galaxy redshifts over a large cosmological volume at low redshifts, complementing high-redshift surveys optimized to constrain dark energy.SPHEREx will be the first all-sky near-infrared spectral survey, creating a legacy archive of spectra. In particular, it will measure the redshifts of over 500 million galaxies of all types, an unprecedented dataset. Using this catalog, SPHEREx will reduce the uncertainty in fNL -- a parameter describing the inflationary initial conditions -- by a factor of more than 10 compared with CMB measurements. At the same time, this catalog will enable strong scientific synergies with Euclid, WFIRST and LSST

  5. The Taipan Galaxy Survey: Scientific Goals and Observing Strategy

    Science.gov (United States)

    da Cunha, Elisabete; Hopkins, Andrew M.; Colless, Matthew; Taylor, Edward N.; Blake, Chris; Howlett, Cullan; Magoulas, Christina; Lucey, John R.; Lagos, Claudia; Kuehn, Kyler; Gordon, Yjan; Barat, Dilyar; Bian, Fuyan; Wolf, Christian; Cowley, Michael J.; White, Marc; Achitouv, Ixandra; Bilicki, Maciej; Bland-Hawthorn, Joss; Bolejko, Krzysztof; Brown, Michael J. I.; Brown, Rebecca; Bryant, Julia; Croom, Scott; Davis, Tamara M.; Driver, Simon P.; Filipovic, Miroslav D.; Hinton, Samuel R.; Johnston-Hollitt, Melanie; Jones, D. Heath; Koribalski, Bärbel; Kleiner, Dane; Lawrence, Jon; Lorente, Nuria; Mould, Jeremy; Owers, Matt S.; Pimbblet, Kevin; Tinney, C. G.; Tothill, Nicholas F. H.; Watson, Fred

    2017-10-01

    The Taipan galaxy survey (hereafter simply `Taipan') is a multi-object spectroscopic survey starting in 2017 that will cover 2π steradians over the southern sky (δ ≲ 10°, |b| ≳ 10°), and obtain optical spectra for about two million galaxies out to z instrument, which includes an innovative `Starbugs' positioning system capable of rapidly and simultaneously deploying up to 150 spectroscopic fibres (and up to 300 with a proposed upgrade) over the 6° diameter focal plane, and a purpose-built spectrograph operating in the range from 370 to 870 nm with resolving power R ≳ 2000. The main scientific goals of Taipan are (i) to measure the distance scale of the Universe (primarily governed by the local expansion rate, H 0) to 1% precision, and the growth rate of structure to 5%; (ii) to make the most extensive map yet constructed of the total mass distribution and motions in the local Universe, using peculiar velocities based on improved Fundamental Plane distances, which will enable sensitive tests of gravitational physics; and (iii) to deliver a legacy sample of low-redshift galaxies as a unique laboratory for studying galaxy evolution as a function of dark matter halo and stellar mass and environment. The final survey, which will be completed within 5 yrs, will consist of a complete magnitude-limited sample (i ⩽ 17) of about 1.2 × 106 galaxies supplemented by an extension to higher redshifts and fainter magnitudes (i ⩽ 18.1) of a luminous red galaxy sample of about 0.8 × 106 galaxies. Observations and data processing will be carried out remotely and in a fully automated way, using a purpose-built automated `virtual observer' software and an automated data reduction pipeline. The Taipan survey is deliberately designed to maximise its legacy value by complementing and enhancing current and planned surveys of the southern sky at wavelengths from the optical to the radio; it will become the primary redshift and optical spectroscopic reference catalogue for

  6. A Light in the Darkness?

    DEFF Research Database (Denmark)

    Brudholm, Thomas

    2007-01-01

    The article considers the implications of how we remember and commemorate so-called "lights in the darkness," such as the rescue of the Jews in Denmark in 1943.......The article considers the implications of how we remember and commemorate so-called "lights in the darkness," such as the rescue of the Jews in Denmark in 1943....

  7. Alternate Models to Dark Energy

    OpenAIRE

    Arun, Kenath; Gudennavar, S B; Prasad, A; Sivaram, C

    2017-01-01

    One of the unresolved questions currently in cosmology is that of the non-linear accelerated expansion of the universe. This has been attributed to the so called Dark Energy (DE). The accelerated expansion of the universe is deduced from measurements of Type Ia supernovae. Here we propose alternate models to account for the Type Ia supernovae measurements without invoking dark energy.

  8. Alternate models to dark energy

    Science.gov (United States)

    Arun, Kenath; Gudennavar, S. B.; Prasad, A.; Sivaram, C.

    2018-01-01

    One of the unresolved questions currently in cosmology is that of the non-linear accelerated expansion of the universe. This has been attributed to the so called Dark Energy (DE). The accelerated expansion of the universe is deduced from measurements of Type Ia supernovae. Here we propose alternate models to account for the Type Ia supernovae measurements without invoking dark energy.

  9. Indirect searches for dark matter

    Indian Academy of Sciences (India)

    The current status of indirect searches for dark matter has been reviewed in a schematic way here. The main relevant experimental results of the recent years have been listed and the excitements and disappointments that their phenomenological interpretations in terms of almost-standard annihilating dark matter have ...

  10. Indirect searches for dark matter

    Indian Academy of Sciences (India)

    Abstract. The current status of indirect searches for dark matter has been reviewed in a schematic way here. The main relevant experimental results of the recent years have been listed and the excite- ments and disappointments that their phenomenological interpretations in terms of almost-standard annihilating dark matter ...

  11. Z2 SIMP dark matter

    International Nuclear Information System (INIS)

    Bernal, Nicolás; Chu, Xiaoyong

    2016-01-01

    Dark matter with strong self-interactions provides a compelling solution to several small-scale structure puzzles. Under the assumption that the coupling between dark matter and the Standard Model particles is suppressed, such strongly interacting massive particles (SIMPs) allow for a successful thermal freeze-out through N-to-N' processes, where N dark matter particles annihilate to N' of them. In the most common scenarios, where dark matter stability is guaranteed by a Z 2 symmetry, the seemingly leading annihilating channel, i.e. 3-to-2 process, is forbidden, so the 4-to-2 one dominate the production of the dark matter relic density. Moreover, cosmological observations require that the dark matter sector is colder than the thermal bath of Standard Model particles, a condition that can be dynamically generated via a small portal between dark matter and Standard Model particles, à la freeze-in. This scenario is exemplified in the context of the Singlet Scalar dark matter model

  12. Non-baryonic dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Berkes, I.

    1996-12-31

    This article discusses the nature of the dark matter and the possibility of the detection of non-baryonic dark matter in an underground experiment. Among the useful detectors the low temperature bolometers are considered in some detail. (author). 19 refs.

  13. Superheavy dark matter

    CERN Document Server

    Riotto, Antonio

    2000-01-01

    It is usually thought that the present mass density of the Universe is dominated by a weakly interacting massive particle (WIMP), a fossil relic of the early Universe. Theoretical ideas and experimental efforts have focused mostly on production and detection of thermal relics, with mass typically in the range a few GeV to a hundred GeV. Here, we will review scenarios for production of nonthermal dark matter whose mass may be in the range 10/sup 12/ to 10/sup 19/ GeV, much larger than the mass of thermal wimpy WIMPS. We will also review recent related results in understanding the production of very heavy fermions through preheating after inflation. (19 refs).

  14. Dark Slope Streaks

    Science.gov (United States)

    2004-01-01

    13 March 2004 Martian slope streaks occur in the regions most heavily mantled by fine, dry dust, particularly Tharsis, Arabia, and the knobby areas between Amazonis and Cerberus. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows some examples of dark slope streaks off of buttes, mesas, and massifs in a dust-mantled crater in central Arabia Terra. New slope streaks form from time to time in the modern martian environment; the streaks in this image probably formed within the past decade. To create them, dust slid or avalanched down the slopes in an almost liquid-like manner. The image is located near 6.8oN, 321.7oW. The picture covers an area 3 km (1.9 mi) across. Sunlight illuminates the scene from the lower left.

  15. Supersymmetric Dark Matter Candidates

    CERN Document Server

    Ellis, John

    2010-01-01

    After reviewing the theoretical, phenomenological and experimental motivations for supersymmetric extensions of the Standard Model, we recall that supersymmetric relics from the Big Bang are expected in models that conserve R parity. We then discuss possible supersymmetric dark matter candidates, focusing on the lightest neutralino and the gravitino. In the latter case, the next-to-lightest supersymmetric particle is expected to be long-lived, and possible candidates include spartners of the tau lepton, top quark and neutrino. We then discuss the roles of the renormalization-group equations and electroweak symmetry breaking in delimiting the supersymmetric parameter space. We discuss in particular the constrained minimal extension of the Standard Model (CMSSM), in which the supersymmetry-breaking parameters are assumed to be universal at the grand unification scale, presenting predictions from a frequentist analysis of its parameter space. We also discuss astrophysical and cosmological constraints on gravitin...

  16. Through a glass, darkly.

    Science.gov (United States)

    Rittenberry, Ronnie

    2005-10-01

    The technology available in today's auto-darkening welding helmets was the stuff of science fiction to welders 30 years ago. A single lens capable of darkening automatically to a variable, preset shade level the instant an arc is struck would have sounded about as realistic as a "Star Trek"-style "transporter" or a cell phone that can take pictures. "It would have been complete and total science fiction," said Kevin Coughlin, president of Hoodlum Welding Gear, Minneapolis. "The technology really didn't exist, so it would be like me telling you your car will be flying in 20 years--you'd look at me and laugh. Even 25 years ago, if someone had told me [the lens] would go from clear to dark when you spark, I'd have said, 'Yeah, right, sure it does.' "

  17. Ultralight particle dark matter

    International Nuclear Information System (INIS)

    Ringwald, A.

    2013-10-01

    We review the physics case for very weakly coupled ultralight particles beyond the Standard Model, in particular for axions and axion-like particles (ALPs): (i) the axionic solution of the strong CP problem and its embedding in well motivated extensions of the Standard Model; (ii) the possibility that the cold dark matter in the Universe is comprised of axions and ALPs; (iii) the ALP explanation of the anomalous transparency of the Universe for TeV photons; and (iv) the axion or ALP explanation of the anomalous energy loss of white dwarfs. Moreover, we present an overview of ongoing and near-future laboratory experiments searching for axions and ALPs: haloscopes, helioscopes, and light-shining-through-a-wall experiments.

  18. Ultralight particle dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Ringwald, A.

    2013-10-15

    We review the physics case for very weakly coupled ultralight particles beyond the Standard Model, in particular for axions and axion-like particles (ALPs): (i) the axionic solution of the strong CP problem and its embedding in well motivated extensions of the Standard Model; (ii) the possibility that the cold dark matter in the Universe is comprised of axions and ALPs; (iii) the ALP explanation of the anomalous transparency of the Universe for TeV photons; and (iv) the axion or ALP explanation of the anomalous energy loss of white dwarfs. Moreover, we present an overview of ongoing and near-future laboratory experiments searching for axions and ALPs: haloscopes, helioscopes, and light-shining-through-a-wall experiments.

  19. Terrestrial Laser Scanning for Measuring Stream Bank Erosion within Legacy Sediments: Data Processing and Analysis Methods

    Science.gov (United States)

    Starek, M. J.; Mitasova, H.; Wegmann, K. W.

    2011-12-01

    Land clearing for agricultural purposes following European settlement of America resulted in upland erosion rates 50-400 times above long-term geologic rates in much of the North Carolina Piedmont region. A considerable amount of the eroded sediment was subsequently aggraded on floodplains and impounded in the slackwater ponds behind milldams. This trapped "legacy" sediment is commonly mistaken for natural floodplain deposition and has remained largely unrecognized as a potential source of accelerated sediment erosion contributing to modern water quality impairment. In this study, terrestrial laser scanning (TLS) is utilized to monitor stream bank evolution along a reach that has breached a former millpond. Due to the unique surface geometry and orientation of the stream bank, vegetation occlusion, and true 3D structure of the point cloud, a systematic data processing approach is implemented to compute the change in sediment volume between repeat TLS surveys. The processing approach consists of the following four steps: 1) segmentation of the stream bank point cloud; 2) transformation of the point cloud such that the xy plane is parallel to the trend of the bank; 3) filter vegetation by selecting local lowest point within a grid cell; 4) smooth high frequency noise 5) generate bare earth digital elevation model (DEM). From the DEMs, change in volume was quantified for a 13 m x 3.5 m section of the stream bank providing an estimate on erosion rates and slumping between surveys. The major mechanisms for the observed changes are freeze-thaw events and fluvial entrainment. To evaluate the surface evolution between the distinct sedimentary layers (legacy vs non-legacy) that comprise the stream bank, elevation change is modeled as a continuous trivariate function z = f(x,y,t) where x,y is horizontal location, t is time, and z is a first-surface referenced elevation. Hence, z=0 for all x,y at t=0, time of first survey. The filtered, transformed, and first

  20. Working Group Report: Dark Energy and CMB

    Energy Technology Data Exchange (ETDEWEB)

    Dodelson, S.; Honscheid, K.; Abazajian, K.; Carlstrom, J.; Huterer, D.; Jain, B.; Kim, A.; Kirkby, D.; Lee, A.; Padmanabhan, N.; Rhodes, J.; Weinberg, D.

    2013-09-20

    The American Physical Society's Division of Particles and Fields initiated a long-term planning exercise over 2012-13, with the goal of developing the community's long term aspirations. The sub-group "Dark Energy and CMB" prepared a series of papers explaining and highlighting the physics that will be studied with large galaxy surveys and cosmic microwave background experiments. This paper summarizes the findings of the other papers, all of which have been submitted jointly to the arXiv.