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Sample records for dark energy survey

  1. Dark Energy Survey

    SciTech Connect (OSTI)

    Roodman, Aaron; Nord, Brian; Elliot, Ann

    2012-12-06

    Members of the Dark Energy Survey collaboration explain what they hope to learn by studying the southern sky with the world's most advanced digital camera, mounted on a telescope in Chile.

  2. Dark Energy Survey

    ScienceCinema (OSTI)

    Roodman, Aaron; Nord, Brian; Elliot, Ann

    2014-08-12

    Members of the Dark Energy Survey collaboration explain what they hope to learn by studying the southern sky with the world's most advanced digital camera, mounted on a telescope in Chile.

  3. The Dark Energy Survey: More than dark energy - An overview

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Abbott, T.

    2016-03-21

    This overview article describes the legacy prospect and discovery potential of the Dark Energy Survey (DES) beyond cosmological studies, illustrating it with examples from the DES early data. DES is using a wide-field camera (DECam) on the 4m Blanco Telescope in Chile to image 5000 sq deg of the sky in five filters (grizY). By its completion the survey is expected to have generated a catalogue of 300 million galaxies with photometric redshifts and 100 million stars. In addition, a time-domain survey search over 27 sq deg is expected to yield a sample of thousands of Type Ia supernovae andmore » other transients. The main goals of DES are to characterise dark energy and dark matter, and to test alternative models of gravity; these goals will be pursued by studying large scale structure, cluster counts, weak gravitational lensing and Type Ia supernovae. However, DES also provides a rich data set which allows us to study many other aspects of astrophysics. In this paper we focus on additional science with DES, emphasizing areas where the survey makes a difference with respect to other current surveys. The paper illustrates, using early data (from `Science Verification', and from the first, second and third seasons of observations), what DES can tell us about the solar system, the Milky Way, galaxy evolution, quasars, and other topics. In addition, we show that if the cosmological model is assumed to be Lambda+ Cold Dark Matter (LCDM) then important astrophysics can be deduced from the primary DES probes. Lastly, highlights from DES early data include the discovery of 34 Trans Neptunian Objects, 17 dwarf satellites of the Milky Way, one published z > 6 quasar (and more confirmed) and two published superluminous supernovae (and more confirmed).« less

  4. The Dark Energy Survey Camera (DECam)

    SciTech Connect (OSTI)

    Diehl, H.Thomas; /Fermilab

    2011-09-09

    The Dark Energy Survey (DES) is a next generation optical survey aimed at understanding the expansion rate of the Universe using four complementary methods: weak gravitational lensing, galaxy cluster counts, baryon acoustic oscillations, and Type Ia supernovae. To perform the survey, the DES Collaboration is building the Dark Energy Camera (DECam), a 3 square degree, 570 Megapixel CCD camera that will be mounted at the prime focus of the Blanco 4-meter telescope at the Cerro Tololo Inter-American Observatory. CCD production has finished, yielding roughly twice the required 62 2k x 4k detectors. The construction of DECam is nearly finished. Integration and commissioning on a 'telescope simulator' of the major hardware and software components, except for the optics, recently concluded at Fermilab. Final assembly of the optical corrector has started at University College, London. Some components have already been received at CTIO. 'First-light' will be sometime in 2012. This oral presentation concentrates on the technical challenges involved in building DECam (and how we overcame them), and the present status of the instrument.

  5. The Dark Energy Survey CCD imager design

    SciTech Connect (OSTI)

    Cease, H.; DePoy, D.; Diehl, H.T.; Estrada, J.; Flaugher, B.; Guarino, V.; Kuk, K.; Kuhlmann, S.; Schultz, K.; Schmitt, R.L.; Stefanik, A.; /Fermilab /Ohio State U. /Argonne

    2008-06-01

    The Dark Energy Survey is planning to use a 3 sq. deg. camera that houses a {approx} 0.5m diameter focal plane of 62 2kx4k CCDs. The camera vessel including the optical window cell, focal plate, focal plate mounts, cooling system and thermal controls is described. As part of the development of the mechanical and cooling design, a full scale prototype camera vessel has been constructed and is now being used for multi-CCD readout tests. Results from this prototype camera are described.

  6. Photometric Redshifts for the Dark Energy Survey and VISTA and...

    Office of Scientific and Technical Information (OSTI)

    We conduct a detailed analysis of the photometric redshift requirements for the proposed Dark Energy Survey (DES) using two sets of mock galaxy simulations and an artificial neural ...

  7. The Dark Energy Survey Data Management System

    SciTech Connect (OSTI)

    Mohr, Joseph J.; Barkhouse, Wayne; Beldica, Cristina; Bertin, Emmanuel; Dora Cai, Y.; Nicolaci da Costa, Luiz A.; Darnell, J.Anthony; Daues, Gregory E.; Jarvis, Michael; Gower, Michelle; 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.

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

    SciTech Connect (OSTI)

    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.

  9. Dark energy properties from large future galaxy surveys

    SciTech Connect (OSTI)

    Basse, Tobias; Bjlde, Ole Eggers; Hannestad, Steen; Hamann, Jan; Wong, Yvonne Y.Y. E-mail: oeb@phys.au.dk E-mail: sth@phys.au.dk

    2014-05-01

    We perform a detailed forecast on how well a Euclid-like survey will be able to constrain dark energy and neutrino parameters from a combination of its cosmic shear power spectrum, galaxy power spectrum, and cluster mass function measurements. We find that the combination of these three probes 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 (?(w{sub p})?(w{sub a})){sup ?1}, we find a value of 690 for Euclid-like data combined with Planck-like measurements of the cosmic microwave background anisotropies in a 10-dimensional cosmological parameter space, assuming a ?CDM fiducial cosmology. For the more commonly used 7-parameter model, we find a figure-of-merit of 1900 for the same data combination. We consider also the survey's potential to measure dark energy perturbations in models wherein the dark energy is parameterised as a fluid with a nonstandard non-adiabatic sound speed, and find that in an optimistic scenario in which w{sub 0} deviates from -1 by as much as is currently observationally allowed, models with c-circumflex {sub s}{sup 2} = 10{sup ?6} and c-circumflex {sub s}{sup 2} = 1 can be distinguished from one another at more than 2? significance. We emphasise that constraints on the dark energy sound speed from cluster measurements are strongly dependent on the modelling of the cluster mass function; significantly weaker sensitivities ensue if we modify our model to include fewer features of nonlinear dark energy clustering. Finally, we find that the sum of neutrino masses can be measured with a 1? precision of 0.015 eV, even in complex cosmological models in which the dark energy equation of state varies with time. The 1? sensitivity to the effective number of relativistic species N{sub eff}{sup ml} is approximately 0.03, meaning that the small deviation of 0.046 from 3 in the standard value of N{sub eff}{sup ml} due to non-instantaneous decoupling and finite

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

    SciTech Connect (OSTI)

    Rossetto, Bruno M.; Santiago, Basílio X.; Girardi, Léo; Camargo, Julio I. B.; Balbinot, Eduardo; da Costa, Luiz N.; Yanny, Brian; Maia, Marcio A. G.; Makler, Martin; Ogando, Ricardo L. C.; Pellegrini, Paulo S.; Ramos, Beatriz; de Simoni, Fernando; Armstrong, R.; Bertin, E.; Desai, S.; Kuropatkin, N.; Lin, H.; Mohr, J. J.; Tucker, D. L.

    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.

  11. THE DARK ENERGY SURVEY: PROSPECTS FOR RESOLVED STELLAR POPULATIONS

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Rossetto, Bruno M.; Santiago, Baslio X.; Girardi, Lo; Camargo, Julio I. B.; Balbinot, Eduardo; da Costa, Luiz N.; Yanny, Brian; Maia, Marcio A. G.; Makler, Martin; Ogando, Ricardo L. C.; et al

    2011-06-01

    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 themoreGalaxy.less

  12. Clouds at CTIO and the Dark Energy Survey

    SciTech Connect (OSTI)

    Neilsen, Jr., Eric

    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.

  13. Automated transient identification in the Dark Energy Survey

    SciTech Connect (OSTI)

    Goldstein, D. A.

    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.

  14. Automated transient identification in the Dark Energy Survey

    SciTech Connect (OSTI)

    Goldstein, D. A.; D'Andrea, C. B.; Fischer, J. A.; Foley, R. J.; Gupta, R. R.; Kessler, R.; Kim, A. G.; Nichol, R. C.; Nungent, P.; Papadopoulos, A.; Sako, M.; Smith, M.; Sullivan, M.; Thomas, R. C.; Wester, W.; Wolf, R. C.; Abdalla, F. B.; Banjeri, M.; Benoit-Levy, A.; Bertin, E.; Brooks, D.; Rosell, A. Carnero; Castander, F. J.; da Costa, L. N.; 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.

    2015-09-01

    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. Furthermore, 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.

  15. Automated transient identification in the Dark Energy Survey

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Goldstein, D. A.; D'Andrea, C. B.; Fischer, J. A.; Foley, R. J.; Gupta, R. R.; Kessler, R.; Kim, A. G.; Nichol, R. C.; Nungent, P.; Papadopoulos, A.; et al

    2015-09-01

    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 factormore » 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. Furthermore, 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.« less

  16. Modeling the transfer function for the Dark Energy Survey

    SciTech Connect (OSTI)

    Chang, C.; Busha, M. T.; Wechsler, R. H.; Refregier, A.; Amara, A.; Rykoff, E.; Becker, M. R.; Bruderer, C.; Gamper, L.; Leistedt, B.; Peiris, H.; Abbott, T.; Abdalla, F. B.; Balbinot, E.; Banerji, M.; Bernstein, R. A.; Bertin, E.; Brooks, D.; Carnero, A.; Desai, S.; da Costa, L. N.; Cunha, C. E.; Eifler, T.; Evrard, A. E.; Fausti Neto, A.; Gerdes, D.; Gruen, D.; James, D.; Kuehn, K.; Maia, M. A. G.; Makler, M.; Ogando, R.; Plazas, A.; Sanchez, E.; Santiago, B.; Schubnell, M.; Sevilla-Noarbe, I.; Smith, C.; Soares-Santos, M.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Zuntz, J.

    2015-03-04

    We present a forward-modelling simulation framework designed to model the data products from the Dark Energy Survey (DES). This forward-model process can be thought of as a transfer function a mapping from cosmological and astronomical signals to the final data products used by the scientists. Using output from the cosmological simulations (the Blind Cosmology Challenge), we generate simulated images (the Ultra Fast Image Simulator, Berge et al. 2013) and catalogs representative of the DES data. In this work we simulate the 244 deg2 coadd images and catalogs in 5 bands for the DES Science Verification (SV) data. The simulation output is compared with the corresponding data to show that major characteristics of the images and catalogs can be captured. We also point out several directions of future improvements. Two practical examples, star/galaxy classification and proximity effects on object detection, are then used to demonstrate how one can use the simulations to address systematics issues in data analysis. With clear understanding of the simplifications in our model, we show that one can use the simulations side-by-side with data products to interpret the measurements. This forward modelling approach is generally applicable for other upcoming and future surveys. As a result, it provides a powerful tool for systematics studies which is sufficiently realistic and highly controllable.

  17. Modeling the transfer function for the Dark Energy Survey

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Chang, C.; Busha, M. T.; Wechsler, R. H.; Refregier, A.; Amara, A.; Rykoff, E.; Becker, M. R.; Bruderer, C.; Gamper, L.; Leistedt, B.; et al

    2015-03-04

    We present a forward-modelling simulation framework designed to model the data products from the Dark Energy Survey (DES). This forward-model process can be thought of as a transfer function a mapping from cosmological and astronomical signals to the final data products used by the scientists. Using output from the cosmological simulations (the Blind Cosmology Challenge), we generate simulated images (the Ultra Fast Image Simulator, Berge et al. 2013) and catalogs representative of the DES data. In this work we simulate the 244 deg2 coadd images and catalogs in 5 bands for the DES Science Verification (SV) data. The simulationmoreoutput is compared with the corresponding data to show that major characteristics of the images and catalogs can be captured. We also point out several directions of future improvements. Two practical examples, star/galaxy classification and proximity effects on object detection, are then used to demonstrate how one can use the simulations to address systematics issues in data analysis. With clear understanding of the simplifications in our model, we show that one can use the simulations side-by-side with data products to interpret the measurements. This forward modelling approach is generally applicable for other upcoming and future surveys. As a result, it provides a powerful tool for systematics studies which is sufficiently realistic and highly controllable.less

  18. Modeling the Transfer Function for the Dark Energy Survey

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Chang, C.

    2015-03-04

    We present a forward-modeling simulation framework designed to model the data products from the Dark Energy Survey (DES). This forward-model process can be thought of as a transfer function—a mapping from cosmological/astronomical signals to the final data products used by the scientists. Using output from the cosmological simulations (the Blind Cosmology Challenge), we generate simulated images (the Ultra Fast Image Simulator) and catalogs representative of the DES data. In this work we demonstrate the framework by simulating the 244 deg2 coadd images and catalogs in five bands for the DES Science Verification data. The simulation output is compared with themore » corresponding data to show that major characteristics of the images and catalogs can be captured. We also point out several directions of future improvements. Two practical examples—star-galaxy classification and proximity effects on object detection—are then used to illustrate how one can use the simulations to address systematics issues in data analysis. With clear understanding of the simplifications in our model, we show that one can use the simulations side-by-side with data products to interpret the measurements. This forward modeling approach is generally applicable for other upcoming and future surveys. It provides a powerful tool for systematics studies that is sufficiently realistic and highly controllable.« less

  19. SUPERNOVA SIMULATIONS AND STRATEGIES FOR THE DARK ENERGY SURVEY

    SciTech Connect (OSTI)

    Bernstein, J. P.; Kuhlmann, S.; Biswas, R.; Kovacs, E.; Crane, I.; Hufford, T.; Kessler, R.; Frieman, J. A.; Aldering, G.; Kim, A. G.; Nugent, P.; D'Andrea, C. B.; Nichol, R. C.; Finley, D. A.; Marriner, J.; Reis, R. R. R.; Jarvis, M. J.; Mukherjee, P.; Parkinson, D.; Sako, M.; and others

    2012-07-10

    We present an analysis of supernova light curves simulated for the upcoming Dark Energy Survey (DES) supernova search. The simulations employ a code suite that generates and fits realistic light curves in order to obtain distance modulus/redshift pairs that are passed to a cosmology fitter. We investigated several different survey strategies including field selection, supernova selection biases, and photometric redshift measurements. Using the results of this study, we chose a 30 deg{sup 2} search area in the griz filter set. We forecast (1) that this survey will provide a homogeneous sample of up to 4000 Type Ia supernovae in the redshift range 0.05

  20. Crowdsourcing quality control for Dark Energy Survey images

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Melchior, P.

    2016-07-01

    We have developed a crowdsourcing web application for image quality controlemployed by the Dark Energy Survey. Dubbed the "DES exposure checker", itrenders science-grade images directly to a web browser and allows users to markproblematic features from a set of predefined classes. Users can also generatecustom labels and thus help identify previously unknown problem classes. Userreports are fed back to hardware and software experts to help mitigate andeliminate recognized issues. We report on the implementation of the applicationand our experience with its over 100 users, the majority of which areprofessional or prospective astronomers but not data management experts. Wediscuss aspects ofmore » user training and engagement, and demonstrate how problemreports have been pivotal to rapidly correct artifacts which would likely havebeen too subtle or infrequent to be recognized otherwise. We conclude with anumber of important lessons learned, suggest possible improvements, andrecommend this collective exploratory approach for future astronomical surveysor other extensive data sets with a sufficiently large user base. We alsorelease open-source code of the web application and host an online demo versionat http://des-exp-checker.pmelchior.net« less

  1. Cosmic shear measurements with Dark Energy Survey Science Verification data

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Becker, M. R.

    2016-07-06

    Here, we present measurements of weak gravitational lensing cosmic shear two-point statistics using Dark Energy Survey Science Verification data. We demonstrate that our results are robust to the choice of shear measurement pipeline, either ngmix or im3shape, and robust to the choice of two-point statistic, including both real and Fourier-space statistics. Our results pass a suite of null tests including tests for B-mode contamination and direct tests for any dependence of the two-point functions on a set of 16 observing conditions and galaxy properties, such as seeing, airmass, galaxy color, galaxy magnitude, etc. We use a large suite of simulationsmore » to compute the covariance matrix of the cosmic shear measurements and assign statistical significance to our null tests. We find that our covariance matrix is consistent with the halo model prediction, indicating that it has the appropriate level of halo sample variance. We also compare the same jackknife procedure applied to the data and the simulations in order to search for additional sources of noise not captured by the simulations. We find no statistically significant extra sources of noise in the data. The overall detection significance with tomography for our highest source density catalog is 9.7σ. Cosmological constraints from the measurements in this work are presented in a companion paper (DES et al. 2015).« less

  2. Crowded Cluster Cores. Algorithms for Deblending in Dark Energy Survey Images

    SciTech Connect (OSTI)

    Zhang, Yuanyuan; McKay, Timothy A.; Bertin, Emmanuel; Jeltema, Tesla; Miller, Christopher J.; Rykoff, Eli; Song, Jeeseon

    2015-10-26

    Deep optical images are often crowded with overlapping objects. We found that this is especially true in the cores of galaxy clusters, where images of dozens of galaxies may lie atop one another. Accurate measurements of cluster properties require deblending algorithms designed to automatically extract a list of individual objects and decide what fraction of the light in each pixel comes from each object. In this article, we introduce a new software tool called the Gradient And Interpolation based (GAIN) deblender. GAIN is used as a secondary deblender to improve the separation of overlapping objects in galaxy cluster cores in Dark Energy Survey images. It uses image intensity gradients and an interpolation technique originally developed to correct flawed digital images. Our paper is dedicated to describing the algorithm of the GAIN deblender and its applications, but we additionally include modest tests of the software based on real Dark Energy Survey co-add images. GAIN helps to extract an unbiased photometry measurement for blended sources and improve detection completeness, while introducing few spurious detections. When applied to processed Dark Energy Survey data, GAIN serves as a useful quick fix when a high level of deblending is desired.

  3. Crowded Cluster Cores. Algorithms for Deblending in Dark Energy Survey Images

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhang, Yuanyuan; McKay, Timothy A.; Bertin, Emmanuel; Jeltema, Tesla; Miller, Christopher J.; Rykoff, Eli; Song, Jeeseon

    2015-10-26

    Deep optical images are often crowded with overlapping objects. We found that this is especially true in the cores of galaxy clusters, where images of dozens of galaxies may lie atop one another. Accurate measurements of cluster properties require deblending algorithms designed to automatically extract a list of individual objects and decide what fraction of the light in each pixel comes from each object. In this article, we introduce a new software tool called the Gradient And Interpolation based (GAIN) deblender. GAIN is used as a secondary deblender to improve the separation of overlapping objects in galaxy cluster cores inmore » Dark Energy Survey images. It uses image intensity gradients and an interpolation technique originally developed to correct flawed digital images. Our paper is dedicated to describing the algorithm of the GAIN deblender and its applications, but we additionally include modest tests of the software based on real Dark Energy Survey co-add images. GAIN helps to extract an unbiased photometry measurement for blended sources and improve detection completeness, while introducing few spurious detections. When applied to processed Dark Energy Survey data, GAIN serves as a useful quick fix when a high level of deblending is desired.« less

  4. Dark Energy | Argonne National Laboratory

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

    Dark Energy Dark Energy The Dark Energy Survey (DES) is a joint project between the U.S. Department of Energy and the National Science Foundation to study the nature of dark matter and dark energy. Dark matter and energy are believed to make up 95 percent of the universe, and their origin and composition are completely unknown. The DES has built a new 520 mega-pixel CCD camera for an existing 4-meter telescope in Chile that will be used for a five-year program of observations. These new

  5. The Dark Energy

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

    Dark Energy Survey: the Movie Brenna Flaugher Josh Frieman Marcelle Soares-Santos John Peoples December 16, 2015 4:00 p.m. - Ramsey Auditorium This public colloquium will center on a showing of a documentary film made by independent Spanish film maker Alex Muntada about cosmic surveys and the laws of physics, with primary focus on the Dark Energy Survey. The Nobel Prize for Physics in 2011 was awarded for the discovery in the late 1990s that the expansion of the Universe is speeding up. Yet the

  6. Observation of Two New L4 Neptune Trojans in the Dark Energy Survey Supernova Fields

    SciTech Connect (OSTI)

    Gerdes, D. W.

    2015-07-18

    We report the discovery of the eighth and ninth known Trojans in stable orbits around Neptune's leading Lagrange point, L4. The objects 2014 QO441 and 2014 QP441 were detected in data obtained during the 2013-14 and 2014-15 observing seasons by the Dark Energy Survey, using the Dark Energy Camera (DECam) on the 4-meter Blanco telescope at Cerro Tololo Inter- American Observatory. Both are in high-inclination orbits (18.8 and 19.4 respectively). Furthermore, with an eccentricity of 0.104, 2014 QO441 has the most eccentric orbit of the eleven known stable Neptune Trojans. We describe the search procedure and investigate the objects' long-term dynamical stability and physical properties.

  7. Observation of two new L4 Neptune Trojans in the Dark Energy Survey supernova fields

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gerdes, D. W.

    2016-01-28

    We report the discovery of the eighth and ninth known Trojans in stable orbits around Neptune's leading Lagrange point, L4. The objects 2014 QO441 and 2014 QP441 were detected in data obtained during the 2013-14 and 2014-15 observing seasons by the Dark Energy Survey, using the Dark Energy Camera (DECam) on the 4-meter Blanco telescope at Cerro Tololo Inter- American Observatory. Both are in high-inclination orbits (18.8° and 19.4° respectively). Furthermore, with an eccentricity of 0.104, 2014 QO441 has the most eccentric orbit of the eleven known stable Neptune Trojans. We describe the search procedure and investigate the objects' long-termmore » dynamical stability and physical properties.« less

  8. OzDES multifibre spectroscopy for the Dark Energy Survey: First-year operation and results

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yuan, Fang

    2015-07-29

    The Australian Dark Energy Survey (OzDES) is a five-year, 100-night, spectroscopic survey on the Anglo-Australian Telescope, whose primary aim is to measure redshifts of approximately 2500 Type Ia supernovae host galaxies over the redshift range 0.1 < z < 1.2, and derive reverberation-mapped black hole masses for approximately 500 active galactic nuclei and quasars over 0.3 < z < 4.5. This treasure trove of data forms a major part of the spectroscopic follow-up for the Dark Energy Survey for which we are also targeting cluster galaxies, radio galaxies, strong lenses, and unidentified transients, as well as measuring luminous red galaxiesmore » and emission line galaxies to help calibrate photometric redshifts. Here, we present an overview of the OzDES programme and our first-year results. Between 2012 December and 2013 December, we observed over 10 000 objects and measured more than 6 000 redshifts. Our strategy of retargeting faint objects across many observing runs has allowed us to measure redshifts for galaxies as faint as mr = 25 mag. We outline our target selection and observing strategy, quantify the redshift success rate for different types of targets, and discuss the implications for our main science goals. In conclusion, we highlight a few interesting objects as examples of the fortuitous yet not totally unexpected discoveries that can come from such a large spectroscopic survey.« less

  9. OzDES multifibre spectroscopy for the Dark Energy Survey: First-year operation and results

    SciTech Connect (OSTI)

    Yuan, Fang

    2015-07-29

    The Australian Dark Energy Survey (OzDES) is a five-year, 100-night, spectroscopic survey on the Anglo-Australian Telescope, whose primary aim is to measure redshifts of approximately 2500 Type Ia supernovae host galaxies over the redshift range 0.1 < z < 1.2, and derive reverberation-mapped black hole masses for approximately 500 active galactic nuclei and quasars over 0.3 < z < 4.5. This treasure trove of data forms a major part of the spectroscopic follow-up for the Dark Energy Survey for which we are also targeting cluster galaxies, radio galaxies, strong lenses, and unidentified transients, as well as measuring luminous red galaxies and emission line galaxies to help calibrate photometric redshifts. Here, we present an overview of the OzDES programme and our first-year results. Between 2012 December and 2013 December, we observed over 10 000 objects and measured more than 6 000 redshifts. Our strategy of retargeting faint objects across many observing runs has allowed us to measure redshifts for galaxies as faint as mr = 25 mag. We outline our target selection and observing strategy, quantify the redshift success rate for different types of targets, and discuss the implications for our main science goals. In conclusion, we highlight a few interesting objects as examples of the fortuitous yet not totally unexpected discoveries that can come from such a large spectroscopic survey.

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

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Chang, C.

    2015-07-29

    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 also 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. Thesemore » 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. Finally, we summarize our key findings in this Letter; the detailed methodology and tests for systematics are presented in a companion paper.« less

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

    SciTech Connect (OSTI)

    Chang, C.

    2015-07-29

    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 also 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. Finally, we summarize our key findings in this Letter; the detailed methodology and tests for systematics are presented in a companion paper.

  12. No Galaxy Left Behind: Accurate Measurements with the Faintest Objects in the Dark Energy Survey

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Suchyta, E.

    2016-01-27

    Accurate statistical measurement with large imaging surveys has traditionally required throwing away a sizable fraction of the data. This is because most measurements have have relied on selecting nearly complete samples, where variations in the composition of the galaxy population with seeing, depth, or other survey characteristics are small. We introduce a new measurement method that aims to minimize this wastage, allowing precision measurement for any class of stars or galaxies detectable in an imaging survey. We have implemented our proposal in Balrog, a software package which embeds fake objects in real imaging in order to accurately characterize measurement biases.more » We also demonstrate this technique with an angular clustering measurement using Dark Energy Survey (DES) data. We first show that recovery of our injected galaxies depends on a wide variety of survey characteristics in the same way as the real data. We then construct a flux-limited sample of the faintest galaxies in DES, chosen specifically for their sensitivity to depth and seeing variations. Using the synthetic galaxies as randoms in the standard LandySzalay correlation function estimator suppresses the effects of variable survey selection by at least two orders of magnitude. Now our measured angular clustering is found to be in excellent agreement with that of a matched sample drawn from much deeper, higherresolution space-based COSMOS imaging; over angular scales of 0.004° < θ < 0.2 ° , we find a best-fit scaling amplitude between the DES and COSMOS measurements of 1.00 ± 0.09. We expect this methodology to be broadly useful for extending the statistical reach of measurements in a wide variety of coming imaging surveys.« less

  13. No Galaxy Left Behind: Accurate Measurements with the Faintest Objects in the Dark Energy Survey

    SciTech Connect (OSTI)

    Suchyta, E.

    2015-07-29

    Accurate statistical measurement with large imaging surveys has traditionally required throwing away a sizable fraction of the data. This is because most measurements have have relied on selecting nearly complete samples, where variations in the composition of the galaxy population with seeing, depth, or other survey characteristics are small. We introduce a new measurement method that aims to minimize this wastage, allowing precision measurement for any class of stars or galaxies detectable in an imaging survey. We have implemented our proposal in Balrog, a software package which embeds fake objects in real imaging in order to accurately characterize measurement biases. We also demonstrate this technique with an angular clustering measurement using Dark Energy Survey (DES) data. We first show that recovery of our injected galaxies depends on a wide variety of survey characteristics in the same way as the real data. We then construct a flux-limited sample of the faintest galaxies in DES, chosen specifically for their sensitivity to depth and seeing variations. Using the synthetic galaxies as randoms in the standard LandySzalay correlation function estimator suppresses the effects of variable survey selection by at least two orders of magnitude. Now our measured angular clustering is found to be in excellent agreement with that of a matched sample drawn from much deeper, higherresolution space-based COSMOS imaging; over angular scales of 0.004° < θ < 0.2 ° , we find a best-fit scaling amplitude between the DES and COSMOS measurements of 1.00 ± 0.09. We expect this methodology to be broadly useful for extending the statistical reach of measurements in a wide variety of coming imaging surveys.

  14. No galaxy left behind. Accurate measurements with the faintest objects in the Dark Energy Survey

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Suchyta, E.; Huff, E. M.; Aleksić, J.; Melchior, P.; Jouvel, S.; MacCrann, N.; Ross, A. J.; Crocce, M.; Gaztanaga, E.; Honscheid, K.; et al

    2016-01-27

    Accurate statistical measurement with large imaging surveys has traditionally required throwing away a sizable fraction of the data. This is because most measurements have relied on selecting nearly complete samples, where variations in the composition of the galaxy population with seeing, depth, or other survey characteristics are small. Here, we introduce a new measurement method that aims to minimize this wastage, allowing precision measurement for any class of detectable stars or galaxies. Moreover, our proposal was implemented in BALROG, software which embeds fake objects in real imaging to accurately characterize measurement biases. We demonstrate this technique with an angular clusteringmore » measurement using Dark Energy Survey (DES) data. We first show that recovery of our injected galaxies depends on a variety of survey characteristics in the same way as the real data. We then construct a flux-limited sample of the faintest galaxies in DES, chosen specifically for their sensitivity to depth and seeing variations. Using the synthetic galaxies as randoms in the Landy–Szalay estimator suppresses the effects of variable survey selection by at least two orders of magnitude. With this correction, our measured angular clustering is found to be in excellent agreement with that of a matched sample from much deeper, higher resolution space-based Cosmological Evolution Survey (COSMOS) imaging; over angular scales of 0.°004 < θ < 0.°2, we find a best-fitting scaling amplitude between the DES and COSMOS measurements of 1.00 ± 0.09. We expect this methodology to be broadly useful for extending measurements’ statistical reach in a variety of upcoming imaging surveys.« less

  15. DESAlert: Enabling real-time transient follow-up with Dark Energy Survey data

    SciTech Connect (OSTI)

    Poci, A.

    2015-04-12

    The Dark Energy Survey (DES) is currently undertaking an observational program imaging 1/4 of the southern hemisphere sky with unprecedented photometric accuracy. In the process of observing millions of faint stars and galaxies to constrain the parameters of the dark energy equation of state, the DES will obtain pre-discovery images of the regions surrounding an estimated 100 gamma-ray bursts (GRBs) over five years. Once GRBs are detected by, e.g., the Swift satellite, the DES data will be extremely useful for follow-up observations by the transient astronomy community. We describe a recently-commissioned suite of software that listens continuously for automated notices of GRB activity, collates useful information from archival DES data, and promulgates relevant data products back to the community in near-real-time. Of particular importance are the opportunities that DES data provide for relative photometry of GRBs or their afterglows, as well as for identifying key characteristics (e.g., photometric redshifts) of potential GRB host galaxies. We provide the functional details of the DESAlert software as it presently operates, as well as the data products that it produces, and we show sample results from the application of DESAlert to several previously-detected GRBs.

  16. Searching for Dark Energy

    SciTech Connect (OSTI)

    Schlegel, David

    2015-05-06

    Berkeley Lab scientist David Schlegel discusses his research on mapping the universe and understanding dark energy.

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

    SciTech Connect (OSTI)

    Soumagnac, M.T.; et al.

    2013-06-21

    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 multi-parameter 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% for stars and by up to 12% for galaxies, at i-magnitude fainter than 23.

  18. Jelly Bean Universe (Dark Matter / Dark Energy)

    ScienceCinema (OSTI)

    Kurt Riesselmann

    2010-01-08

    Fermilab's Kurt Riesselmann explains how to make a jelly bean universe to help explain the mysteries of dark matter and dark energy.

  19. Jelly Bean Universe (Dark Matter / Dark Energy)

    SciTech Connect (OSTI)

    Kurt Riesselmann

    2009-09-10

    Fermilab's Kurt Riesselmann explains how to make a jelly bean universe to help explain the mysteries of dark matter and dark energy.

  20. Eight new Milky Way companions discovered in first-year Dark Energy Survey data

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bechtol, K.

    2015-06-30

    We report the discovery of eight new Milky Way companions inmore » $$\\sim 1800\\;{\\mathrm{deg}}^{2}$$ of optical imaging data collected during the first year of the Dark Energy Survey (DES). Each system is identified as a statistically significant over-density of individual stars consistent with the expected isochrone and luminosity function of an old and metal-poor stellar population. The objects span a wide range of absolute magnitudes (MV from $-2.2$ to $$-7.4\\;\\mathrm{mag}$$), physical sizes ($$10-170\\;\\mathrm{pc}$$), and heliocentric distances ($$30-330\\;\\mathrm{kpc}$$). Based on the low surface brightnesses, large physical sizes, and/or large Galactocentric distances of these objects, several are likely to be new ultra-faint satellite galaxies of the Milky Way and/or Magellanic Clouds. We introduce a likelihood-based algorithm to search for and characterize stellar over-densities, as well as identify stars with high satellite membership probabilities. As a result, we also present completeness estimates for detecting ultra-faint galaxies of varying luminosities, sizes, and heliocentric distances in the first-year DES data.« less

  1. Eight new Milky Way companions discovered in first-year Dark Energy Survey data

    SciTech Connect (OSTI)

    Bechtol, K.; et al.

    2015-06-30

    We report the discovery of eight new Milky Way companions in $\\sim 1800\\;{\\mathrm{deg}}^{2}$ of optical imaging data collected during the first year of the Dark Energy Survey (DES). Each system is identified as a statistically significant over-density of individual stars consistent with the expected isochrone and luminosity function of an old and metal-poor stellar population. The objects span a wide range of absolute magnitudes (MV from $-2.2$ to $-7.4\\;\\mathrm{mag}$), physical sizes ($10-170\\;\\mathrm{pc}$), and heliocentric distances ($30-330\\;\\mathrm{kpc}$). Based on the low surface brightnesses, large physical sizes, and/or large Galactocentric distances of these objects, several are likely to be new ultra-faint satellite galaxies of the Milky Way and/or Magellanic Clouds. We introduce a likelihood-based algorithm to search for and characterize stellar over-densities, as well as identify stars with high satellite membership probabilities. As a result, we also present completeness estimates for detecting ultra-faint galaxies of varying luminosities, sizes, and heliocentric distances in the first-year DES data.

  2. Discovery of a Stellar Overdensity in Eridanus-Phoenix in the Dark Energy Survey

    SciTech Connect (OSTI)

    Li, T.S.; et al.

    2015-09-14

    We report the discovery of an excess of main sequence turn-off stars in the direction of the constellations of Eridanus and Phoenix from the first year data of the Dark Energy Survey (DES). The Eridanus-Phoenix (EriPhe) overdensity is centered around l~285 deg and b~-60 deg and spans at least 30 deg in longitude and 10 deg in latitude. The Poisson significance of the detection is at least 9 sigma. The stellar population in the overdense region is similar in brightness and color to that of the nearby globular cluster NGC 1261, indicating that the heliocentric distance of EriPhe is about d~16 kpc. The extent of EriPhe in projection is therefore at least ~4 kpc by ~3 kpc. On the sky, this overdensity is located between NGC 1261 and a new stellar stream discovered by DES at a similar heliocentric distance, the so-called Phoenix Stream. Given their similar distance and proximity to each other, it is possible that these three structures may be kinematically associated. Alternatively, the EriPhe overdensity is morphologically similar to the Virgo overdensity and the Hercules-Aquila cloud, which also lie at a similar Galactocentric distance. These three overdensities lie along a polar plane separated by ~120 deg and may share a common origin. Spectroscopic follow-up observations of the stars in EriPhe are required to fully understand the nature of this overdensity.

  3. Discovery of a stellar overdensity in Eridanus-Phoenix in the dark energy survey

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Li, T. S.; Balbinot, E.; Mondrik, N.; Marshall, J. L.; Yanny, B.; Bechtol, K.; Drlica-Wagner, A.; Oscar, D.; Santiago, B.; Simon, J. D.; et al

    2016-01-27

    We report the discovery of an excess of main sequence turn-off stars in the direction of the constellations of Eridanus and Phoenix from the first year data of the Dark Energy Survey (DES). The Eridanus-Phoenix (EriPhe) overdensity is centered around l~285 deg and b~-60 deg and spans at least 30 deg in longitude and 10 deg in latitude. The Poisson significance of the detection is at least 9 sigma. The stellar population in the overdense region is similar in brightness and color to that of the nearby globular cluster NGC 1261, indicating that the heliocentric distance of EriPhe is aboutmore » d~16 kpc. The extent of EriPhe in projection is therefore at least ~4 kpc by ~3 kpc. On the sky, this overdensity is located between NGC 1261 and a new stellar stream discovered by DES at a similar heliocentric distance, the so-called Phoenix Stream. Given their similar distance and proximity to each other, it is possible that these three structures may be kinematically associated. Alternatively, the EriPhe overdensity is morphologically similar to the Virgo overdensity and the Hercules-Aquila cloud, which also lie at a similar Galactocentric distance. These three overdensities lie along a polar plane separated by ~120 deg and may share a common origin. Spectroscopic follow-up observations of the stars in EriPhe are required to fully understand the nature of this overdensity.« less

  4. Discovery of two gravitationally lensed quasars in the Dark Energy Survey

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Agnello, A.

    2015-10-01

    In this study, we present spectroscopic confirmation of two new lensed quasars via data obtained at the 6.5m Magellan/Baade Telescope. The lens candidates have been selected from the Dark Energy Survey (DES) and WISE based on their multi-band photometry and extended morphology in DES images. Images of DES J0115-5244 show two blue point sources at either side of a red galaxy. Our long-slit data confirm that both point sources are images of the same quasar at zs = 1.64. The Einstein Radius estimated from the DES images is 0.51''. DES J2146-0047 is in the area of overlap between DES andmore » the Sloan Digital Sky Survey (SDSS). Two blue components are visible in the DES and SDSS images. The SDSS fiber spectrum shows a quasar component at zs = 2.38 and absorption compatible with Mg II and Fe II at zl = 0.799, which we tentatively associate with the foreground lens galaxy. The long-slit Magellan spectra show that the blue components are resolved images of the same quasar. Furthermore, the Einstein Radius is 0.68'' corresponding to an enclosed mass of 1.6 × 1011 M⊙. Three other candidates were observed and rejected, two being low-redshift pairs of starburst galaxies, and one being a quasar behind a blue star. These first confirmation results provide an important empirical validation of the data-mining and model-based selection that is being applied to the entire DES dataset.« less

  5. Eight ultra-faint galaxy candidates discovered in year two of the Dark Energy Survey

    SciTech Connect (OSTI)

    Drlica-Wagner, A.

    2015-11-04

    We report the discovery of eight new ultra-faint dwarf galaxy candidates in the second year of optical imaging data from the Dark Energy Survey (DES). Six of these candidates are detected at high confidence, while two lower-confidence candidates are identified in regions of non-uniform survey coverage. The new stellar systems are found by three independent automated search techniques and are identified as overdensities of stars, consistent with the isochrone and luminosity function of an old and metal-poor simple stellar population. The new systems are faint (MV > -4.7 ) and span a range of physical sizes (17 pc < r1/2 < 181pc) and heliocentric distances (25 kpc < D < 214 kpc). All of the new systems have central surface brightnesses consistent with known ultra-faint dwarf galaxies (μ 27.5 mag arcsec -2). Roughly half of the DES candidates are more distant, less luminous, and/or have lower surface brightnesses than previously known Milky Way satellite galaxies. Most of the candidates are found in the southern part of the DES footprint close to the Magellanic Clouds. We find that the DES data alone exclude (p < 10-3) a spatially isotropic distribution of Milky Way satellites and that the observed distribution can be well, though not uniquely, described by an association between several of the DES satellites and the Magellanic system. Furthermore, our model predicts that the full sky may hold ~100 ultra-faint galaxies with physical properties comparable to the DES satellites and that 20%–30% of these would be spatially associated with the Magellanic Clouds.

  6. Eight ultra-faint galaxy candidates discovered in year two of the Dark Energy Survey

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Drlica-Wagner, A.

    2015-11-04

    We report the discovery of eight new ultra-faint dwarf galaxy candidates in the second year of optical imaging data from the Dark Energy Survey (DES). Six of these candidates are detected at high confidence, while two lower-confidence candidates are identified in regions of non-uniform survey coverage. The new stellar systems are found by three independent automated search techniques and are identified as overdensities of stars, consistent with the isochrone and luminosity function of an old and metal-poor simple stellar population. The new systems are faint (MV > -4.7 ) and span a range of physical sizes (17 pc < r1/2more » < 181pc) and heliocentric distances (25 kpc < D⊙ < 214 kpc). All of the new systems have central surface brightnesses consistent with known ultra-faint dwarf galaxies (μ 27.5 mag arcsec -2). Roughly half of the DES candidates are more distant, less luminous, and/or have lower surface brightnesses than previously known Milky Way satellite galaxies. Most of the candidates are found in the southern part of the DES footprint close to the Magellanic Clouds. We find that the DES data alone exclude (p < 10-3) a spatially isotropic distribution of Milky Way satellites and that the observed distribution can be well, though not uniquely, described by an association between several of the DES satellites and the Magellanic system. Furthermore, our model predicts that the full sky may hold ~100 ultra-faint galaxies with physical properties comparable to the DES satellites and that 20%–30% of these would be spatially associated with the Magellanic Clouds.« less

  7. Discovery of two gravitationally lensed quasars in the Dark Energy Survey

    SciTech Connect (OSTI)

    Agnello, A.

    2015-10-01

    In this study, we present spectroscopic confirmation of two new lensed quasars via data obtained at the 6.5m Magellan/Baade Telescope. The lens candidates have been selected from the Dark Energy Survey (DES) and WISE based on their multi-band photometry and extended morphology in DES images. Images of DES J0115-5244 show two blue point sources at either side of a red galaxy. Our long-slit data confirm that both point sources are images of the same quasar at zs = 1.64. The Einstein Radius estimated from the DES images is 0.51''. DES J2146-0047 is in the area of overlap between DES and the Sloan Digital Sky Survey (SDSS). Two blue components are visible in the DES and SDSS images. The SDSS fiber spectrum shows a quasar component at zs = 2.38 and absorption compatible with Mg II and Fe II at zl = 0.799, which we tentatively associate with the foreground lens galaxy. The long-slit Magellan spectra show that the blue components are resolved images of the same quasar. Furthermore, the Einstein Radius is 0.68'' corresponding to an enclosed mass of 1.6 1011 M?. Three other candidates were observed and rejected, two being low-redshift pairs of starburst galaxies, and one being a quasar behind a blue star. These first confirmation results provide an important empirical validation of the data-mining and model-based selection that is being applied to the entire DES dataset.

  8. The Difference Imaging Pipeline for the Transient Search in the Dark Energy Survey

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kessler, R.

    2015-09-09

    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 deg2 fields are repeatedly observed in the g, r, i, zpassbands with a cadence of about 1 week. Our 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 aremore » 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 ~130 detections per deg2 per observation in each band, of which only ~25% are artifacts. Of the ~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 ~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. Furthermore, 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 ~23.5, the SN Ia efficiency falls to 1/2 at redshift z ≈ 0.7; in our 2 "deep

  9. The Difference Imaging Pipeline for the Transient Search in the Dark Energy Survey

    SciTech Connect (OSTI)

    Kessler, R.

    2015-09-09

    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 deg2 fields are repeatedly observed in the g, r, i, zpassbands with a cadence of about 1 week. Our 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 ~130 detections per deg2 per observation in each band, of which only ~25% are artifacts. Of the ~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 ~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. Furthermore, 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 ~23.5, the SN Ia efficiency falls to 1/2 at redshift z ≈ 0.7; in our

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

    SciTech Connect (OSTI)

    Melchior, P.; et al.

    2015-05-21

    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.

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

    SciTech Connect (OSTI)

    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 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 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. Additionally, 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 1degree (approximately 20 Mpc), showcasing the potential of DECam and DES for detailed studies of degree-scale features on the sky.

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

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Melchior, P.; Suchyta, E.; Huff, E.; Hirsch, M.; Kacprzak, T.; Rykoff, E.; Gruen, D.; Armstrong, R.; Bacon, D.; Bechtol, K.; et al

    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 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 Sciencemore » 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 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. Additionally, 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 1degree (approximately 20 Mpc), showcasing the potential of DECam and DES for detailed studies of degree-scale features on the sky.« less

  13. The Dark Energy Camera

    SciTech Connect (OSTI)

    Flaugher, B.

    2015-04-11

    The Dark Energy Camera is a new imager with a 2.2-degree diameter field of view mounted at the prime focus of the Victor M. Blanco 4-meter 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 CCD focal plane of 250-μm thick fully depleted CCDs cooled inside a vacuum Dewar. The 570 Mpixel focal plane comprises 62 2k x 4k CCDs for imaging and 12 2k x 2k CCDs for guiding and focus. The CCDs have 15μm x 15μm pixels with a plate scale of 0.263" per pixel. A hexapod system provides state-of-the-art focus and alignment capability. The camera is read out in 20 seconds with 6-9 electrons readout noise. This paper provides a technical description of the camera's engineering, construction, installation, and current status.

  14. DES13S2cmm: The first superluminous supernova from the Dark Energy Survey

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Papadopoulos, A.; Plazas, A. A.; D"Andrea, C. B.; Sullivan, M.; Nichol, R. C.; Barbary, K.; Biswas, R.; Brown, P. J.; Covarrubias, R. A.; Finley, D. A.; et al

    2015-03-23

    We present DES13S2cmm, the first spectroscopically-confirmed superluminous supernova (SLSN) from the Dark Energy Survey (DES). We briefly discuss the data and search algorithm used to find this event in the first year of DES operations, and outline the spectroscopic data obtained from the European Southern Observatory (ESO) Very Large Telescope to confirm its redshift (z = 0.663 ± 0.001 based on the host-galaxy emission lines) and likely spectral type (type I). Using this redshift, we find MpeakU = –21.05+0.10–0.09 for the peak, rest-frame U-band absolute magnitude, and find DES13S2cmm to be located in a faint, low-metallicity (sub-solar), low stellar-mass hostmore » galaxy (log(M/M⊙) = 9.3 ± 0.3), consistent with what is seen for other SLSNe-I. We compare the bolometric light curve of DES13S2cmm to fourteen similarly well-observed SLSNe-I in the literature and find it possesses one of the slowest declining tails (beyond +30 days rest frame past peak), and is the faintest at peak. Moreover, we find the bolometric light curves of all SLSNe-I studied herein possess a dispersion of only 0.2–0.3 magnitudes between +25 and +30 days after peak (rest frame) depending on redshift range studied; this could be important for ‘standardising’ such supernovae, as is done with the more common type Ia. We fit the bolometric light curve of DES13S2cmm with two competing models for SLSNe-I – the radioactive decay of ⁵⁶Ni, and a magnetar – and find that while the magnetar is formally a better fit, neither model provides a compelling match to the data. Although we are unable to conclusively differentiate between these two physical models for this particular SLSN-I, further DES observations of more SLSNe-I should break this degeneracy, especially if the light curves of SLSNe-I can be observed beyond 100 days in the rest frame of the supernova.« less

  15. DES13S2cmm: The first superluminous supernova from the Dark Energy Survey

    SciTech Connect (OSTI)

    Papadopoulos, A.; Plazas, A. A.; D"Andrea, C. B.; Sullivan, M.; Nichol, R. C.; Barbary, K.; Biswas, R.; Brown, P. J.; Covarrubias, R. A.; Finley, D. A.; Fischer, J. A.; Foley, R. J.; Goldstein, D.; Gupta, R. R.; Kessler, R.; Kovacs, E.; Kuhlmann, S. E.; Lidman, C.; March, M.; Nugent, P. E.; Sako, M.; Smith, R. C.; Spinka, H.; Wester, W.; Abbott, T. M. C.; Abdalla, F.; Allam, S. S.; Banerji, M.; Bernstein, J. P.; Bernstein, R. A.; Carnero, A.; da Costa, L. N.; DePoy, D. L.; Desai, S.; Diehl, H. T.; Eifler, T.; Evrard, A. E.; Flaugher, B.; Frieman, J. A.; Gerdes, D.; Gruen, D.; Honscheid, K.; James, D.; Kuehn, K.; Kuropatkin, N.; Lahav, O.; Maia, M. A. G.; Makler, M.; Marshall, J. L.; Merritt, K. W.; Miller, C. J.; Miquel, R.; Ogando, R.; Roe, N. A.; Romer, A. K.; Rykoff, E.; Sanchez, E.; Santiago, B. X.; Scarpine, V.; Schubnell, M.; Sevilla, I.; Soares-Santos, M.; Suchyta, E.; Swanson, M.; Tarle, G.; Thaler, J.; Tucker, L. D.; Wechsler, R. H.; Zuntz, J.

    2015-03-23

    We present DES13S2cmm, the first spectroscopically-confirmed superluminous supernova (SLSN) from the Dark Energy Survey (DES). We briefly discuss the data and search algorithm used to find this event in the first year of DES operations, and outline the spectroscopic data obtained from the European Southern Observatory (ESO) Very Large Telescope to confirm its redshift (z = 0.663 ± 0.001 based on the host-galaxy emission lines) and likely spectral type (type I). Using this redshift, we find MpeakU = –21.05+0.10–0.09 for the peak, rest-frame U-band absolute magnitude, and find DES13S2cmm to be located in a faint, low-metallicity (sub-solar), low stellar-mass host galaxy (log(M/M⊙) = 9.3 ± 0.3), consistent with what is seen for other SLSNe-I. We compare the bolometric light curve of DES13S2cmm to fourteen similarly well-observed SLSNe-I in the literature and find it possesses one of the slowest declining tails (beyond +30 days rest frame past peak), and is the faintest at peak. Moreover, we find the bolometric light curves of all SLSNe-I studied herein possess a dispersion of only 0.2–0.3 magnitudes between +25 and +30 days after peak (rest frame) depending on redshift range studied; this could be important for ‘standardising’ such supernovae, as is done with the more common type Ia. We fit the bolometric light curve of DES13S2cmm with two competing models for SLSNe-I – the radioactive decay of ⁵⁶Ni, and a magnetar – and find that while the magnetar is formally a better fit, neither model provides a compelling match to the data. Although we are unable to conclusively differentiate between these two physical models for this particular SLSN-I, further DES observations of more SLSNe-I should break this degeneracy, especially if the light curves of SLSNe-I can be observed beyond 100 days in the rest frame of the supernova.

  16. DES13S2cmm: The first superluminous supernova from the dark energy survey

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Papadopoulos, A.; D'Andrea, C. B.; Sullivan, M.; Nichol, R. C.; Barbary, K.; Biswas, R.; Brown, P. J.; Covarrubias, R. A.; Finley, D. A.; Fischer, J. A.; et al

    2015-03-23

    We present DES13S2cmm, the first spectroscopically-confirmed superluminous supernova (SLSN) from the Dark Energy Survey (DES). We briefly discuss the data and search algorithm used to find this event in the first year of DES operations, and outline the spectroscopic data obtained from the European Southern Observatory (ESO) Very Large Telescope to confirm its redshift (z = 0.663 0.001 based on the host-galaxy emission lines) and likely spectral type (type I). Using this redshift, we find MUpeak = -21.05????-0.09 for the peak, rest-frame U-band absolute magnitude, and find DES13S2cmm to be located in a faint, low metallicity (sub-solar), low stellar-massmorehost galaxy (log(M/M_sun) = 9.3 0.3); consistent with what is seen for other SLSNe-I. We compare the bolometric light curve of DES13S2cmm to fourteen similarly well-observed SLSNe-I in the literature and find it possesses one of the slowest declining tails (beyond +30 days rest frame past peak), and is the faintest at peak. Moreover, we find the bolometric light curves of all SLSNe-I studied herein possess a dispersion of only 0.2-0.3 magnitudes between +25 and +30 days after peak (rest frame) depending on redshift range studied; this could be important for 'standardising' such supernovae, as is done with the more common type Ia. We fit the bolometric light curve of DES13S2cmm with two competing models for SLSNe-I - the radioactive decay of ??Ni, and a magnetar - and find that while the magnetar is formally a better fit, neither model provides a compelling match to the data. Although we are unable to conclusively differentiate between these two physical models for this particular SLSN-I, further DES observations of more SLSNe-I should break this degeneracy, especially if the light curves of SLSNe-I can be observed beyond 100 days in the rest frame of the supernova.less

  17. DES13S2cmm: The first superluminous supernova from the Dark Energy Survey

    SciTech Connect (OSTI)

    Papadopoulos, A.; Plazas, A. A.; D"Andrea, C. B.; Sullivan, M.; Nichol, R. C.; Barbary, K.; Biswas, R.; Brown, P. J.; Covarrubias, R. A.; Finley, D. A.; Fischer, J. A.; Foley, R. J.; Goldstein, D.; Gupta, R. R.; Kessler, R.; Kovacs, E.; Kuhlmann, S. E.; Lidman, C.; March, M.; Nugent, P. E.; Sako, M.; Smith, R. C.; Spinka, H.; Wester, W.; Abbott, T. M. C.; Abdalla, F.; Allam, S. S.; Banerji, M.; Bernstein, J. P.; Bernstein, R. A.; Carnero, A.; da Costa, L. N.; DePoy, D. L.; Desai, S.; Diehl, H. T.; Eifler, T.; Evrard, A. E.; Flaugher, B.; Frieman, J. A.; Gerdes, D.; Gruen, D.; Honscheid, K.; James, D.; Kuehn, K.; Kuropatkin, N.; Lahav, O.; Maia, M. A. G.; Makler, M.; Marshall, J. L.; Merritt, K. W.; Miller, C. J.; Miquel, R.; Ogando, R.; Roe, N. A.; Romer, A. K.; Rykoff, E.; Sanchez, E.; Santiago, B. X.; Scarpine, V.; Schubnell, M.; Sevilla, I.; Soares-Santos, M.; Suchyta, E.; Swanson, M.; Tarle, G.; Thaler, J.; Tucker, L. D.; Wechsler, R. H.; Zuntz, J.

    2015-03-23

    We present DES13S2cmm, the first spectroscopically-confirmed superluminous supernova (SLSN) from the Dark Energy Survey (DES). We briefly discuss the data and search algorithm used to find this event in the first year of DES operations, and outline the spectroscopic data obtained from the European Southern Observatory (ESO) Very Large Telescope to confirm its redshift (z = 0.663 0.001 based on the host-galaxy emission lines) and likely spectral type (type I). Using this redshift, we find MpeakU = 21.05+0.100.09 for the peak, rest-frame U-band absolute magnitude, and find DES13S2cmm to be located in a faint, low-metallicity (sub-solar), low stellar-mass host galaxy (log(M/M?) = 9.3 0.3), consistent with what is seen for other SLSNe-I. We compare the bolometric light curve of DES13S2cmm to fourteen similarly well-observed SLSNe-I in the literature and find it possesses one of the slowest declining tails (beyond +30 days rest frame past peak), and is the faintest at peak. Moreover, we find the bolometric light curves of all SLSNe-I studied herein possess a dispersion of only 0.20.3 magnitudes between +25 and +30 days after peak (rest frame) depending on redshift range studied; this could be important for standardising such supernovae, as is done with the more common type Ia. We fit the bolometric light curve of DES13S2cmm with two competing models for SLSNe-I the radioactive decay of ??Ni, and a magnetar and find that while the magnetar is formally a better fit, neither model provides a compelling match to the data. Although we are unable to conclusively differentiate between these two physical models for this particular SLSN-I, further DES observations of more SLSNe-I should break this degeneracy, especially if the light curves of SLSNe-I can be observed beyond 100 days in the rest frame of the supernova.

  18. Dark Energy, or Worse

    SciTech Connect (OSTI)

    Carroll, Sean

    2006-11-13

    General relativity is inconsistent with cosmological observations unless we invoke components of dark matter and dark energy that dominate the universe. While it seems likely that these exotic substances really do exist, the alternative is worth considering: that Einstein's general relativity breaks down on cosmological scales. I will discuss models of modified gravity, tests in the solar system and elsewhere, and consequences for cosmology.

  19. Dark Energy, or Worse

    ScienceCinema (OSTI)

    Professor Sean Carroll

    2010-01-08

    General relativity is inconsistent with cosmological observations unless we invoke components of dark matter and dark energy that dominate the universe. While it seems likely that these exotic substances really do exist, the alternative is worth considering: that Einstein's general relativity breaks down on cosmological scales. I will discuss models of modified gravity, tests in the solar system and elsewhere, and consequences for cosmology.

  20. Wide-field lensing mass maps from Dark Energy Survey science verification data: Methodology and detailed analysis

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Vikram, V.

    2015-07-29

    Weak gravitational lensing allows one to reconstruct the spatial distribution of the projected mass density across the sky. These “mass maps” provide a powerful tool for studying cosmology as they probe both luminous and dark matter. In this paper, we present a weak lensing mass map reconstructed from shear measurements in a 139 deg2 area from the Dark Energy Survey (DES) science verification data. We compare the distribution of mass with that of the foreground distribution of galaxies and clusters. The overdensities in the reconstructed map correlate well with the distribution of optically detected clusters. We demonstrate that candidate superclustersmore » and voids along the line of sight can be identified, exploiting the tight scatter of the cluster photometric redshifts. We cross-correlate the mass map with a foreground magnitude-limited galaxy sample from the same data. Our measurement gives results consistent with mock catalogs from N-body simulations that include the primary sources of statistical uncertainties in the galaxy, lensing, and photo-z catalogs. The statistical significance of the cross-correlation is at the 6.8σ level with 20 arcminute smoothing. We find that the contribution of systematics to the lensing mass maps is generally within measurement uncertainties. In this study, we analyze less than 3% of the final area that will be mapped by the DES; the tools and analysis techniques developed in this paper can be applied to forthcoming larger data sets from the survey.« less

  1. Wide-field lensing mass maps from Dark Energy Survey science verification data: Methodology and detailed analysis

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Vikram, V.; Sheldon, E.; Chang, C.; Jain, B.; Bacon, D.; Amara, A.; Becker, M. R.; Bernstein, G.; Bonnett, C.; Bridle, S.; et al

    2015-07-29

    Weak gravitational lensing allows one to reconstruct the spatial distribution of the projected mass density across the sky. These mass maps provide a powerful tool for studying cosmology as they probe both luminous and dark matter. In this paper, we present a weak lensing mass map reconstructed from shear measurements in a 139 deg2 area from the Dark Energy Survey science verification data. We compare the distribution of mass with that of the foreground distribution of galaxies and clusters. The overdensities in the reconstructed map correlate well with the distribution of optically detected clusters. We demonstrate that candidate superclusters andmorevoids along the line of sight can be identified, exploiting the tight scatter of the cluster photometric redshifts. We cross-correlate the mass map with a foreground magnitude-limited galaxy sample from the same data. Our measurement gives results consistent with mock catalogs from N-body simulations that include the primary sources of statistical uncertainties in the galaxy, lensing, and photo-z catalogs. The statistical significance of the cross-correlation is at the 6.8? level with 20 arcminute smoothing. We find that the contribution of systematics to the lensing mass maps is generally within measurement uncertainties. We analyze less than 3% of the final area that will be mapped by the DES; the tools and analysis techniques developed in this paper can be applied to forthcoming larger data sets from the survey.less

  2. Wide-field lensing mass maps from Dark Energy Survey science verification data: Methodology and detailed analysis

    SciTech Connect (OSTI)

    Vikram, V.; Sheldon, E.; Chang, C.; 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.; Kovacs, A.; Lahav, O.; Leistedt, B.; Lin, H.; Melchior, P.; Peiris, H.; Rozo, E.; Rykoff, E.; Sanchez, C.; Sheldon, E.; Troxel, M. A.; Wechsler, R.; Zuntz, J.; Abbott, T.; Abdalla, F. B.; Armstrong, R.; Banerji, M.; Bauer, A. H.; Benoit-Levy, A.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Burke, D. L.; Capozzi, D.; Carnero Rosell, A.; Kind, M. Carrasco; Castander, F. J.; Crocce, M.; Cunha, C. E.

    2015-07-29

    Weak gravitational lensing allows one to reconstruct the spatial distribution of the projected mass density across the sky. These mass maps provide a powerful tool for studying cosmology as they probe both luminous and dark matter. In this paper, we present a weak lensing mass map reconstructed from shear measurements in a 139 deg2 area from the Dark Energy Survey science verification data. We compare the distribution of mass with that of the foreground distribution of galaxies and clusters. The overdensities in the reconstructed map correlate well with the distribution of optically detected clusters. We demonstrate that candidate superclusters and voids along the line of sight can be identified, exploiting the tight scatter of the cluster photometric redshifts. We cross-correlate the mass map with a foreground magnitude-limited galaxy sample from the same data. Our measurement gives results consistent with mock catalogs from N-body simulations that include the primary sources of statistical uncertainties in the galaxy, lensing, and photo-z catalogs. The statistical significance of the cross-correlation is at the 6.8? level with 20 arcminute smoothing. We find that the contribution of systematics to the lensing mass maps is generally within measurement uncertainties. We analyze less than 3% of the final area that will be mapped by the DES; the tools and analysis techniques developed in this paper can be applied to forthcoming larger data sets from the survey.

  3. Wide-field lensing mass maps from Dark Energy Survey science verification data: Methodology and detailed analysis

    SciTech Connect (OSTI)

    Vikram, V.

    2015-07-29

    Weak gravitational lensing allows one to reconstruct the spatial distribution of the projected mass density across the sky. These mass maps provide a powerful tool for studying cosmology as they probe both luminous and dark matter. In this paper, we present a weak lensing mass map reconstructed from shear measurements in a 139 deg2 area from the Dark Energy Survey (DES) science verification data. We compare the distribution of mass with that of the foreground distribution of galaxies and clusters. The overdensities in the reconstructed map correlate well with the distribution of optically detected clusters. We demonstrate that candidate superclusters and voids along the line of sight can be identified, exploiting the tight scatter of the cluster photometric redshifts. We cross-correlate the mass map with a foreground magnitude-limited galaxy sample from the same data. Our measurement gives results consistent with mock catalogs from N-body simulations that include the primary sources of statistical uncertainties in the galaxy, lensing, and photo-z catalogs. The statistical significance of the cross-correlation is at the 6.8? level with 20 arcminute smoothing. We find that the contribution of systematics to the lensing mass maps is generally within measurement uncertainties. In this study, we analyze less than 3% of the final area that will be mapped by the DES; the tools and analysis techniques developed in this paper can be applied to forthcoming larger data sets from the survey.

  4. Big Mysteries: Dark Energy

    ScienceCinema (OSTI)

    Lincoln, Don

    2014-08-07

    Scientists were shocked in 1998 when the expansion of the universe wasn't slowing down as expected by our best understanding of gravity at the time; the expansion was speeding up! That observation is just mind blowing, and yet it is true. In order to explain the data, physicists had to resurrect an abandoned idea of Einstein's now called dark energy. In this video, Fermilab's Dr. Don Lincoln tells us a little about the observations that led to the hypothesis of dark energy and what is the status of current research on the subject.

  5. Big Mysteries: Dark Energy

    SciTech Connect (OSTI)

    Lincoln, Don

    2014-04-15

    Scientists were shocked in 1998 when the expansion of the universe wasn't slowing down as expected by our best understanding of gravity at the time; the expansion was speeding up! That observation is just mind blowing, and yet it is true. In order to explain the data, physicists had to resurrect an abandoned idea of Einstein's now called dark energy. In this video, Fermilab's Dr. Don Lincoln tells us a little about the observations that led to the hypothesis of dark energy and what is the status of current research on the subject.

  6. Digging deeper into the Southern skies: A compact Milky Way companion discovered in first-year Dark Energy Survey data

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Luque, E.

    2016-02-09

    Here, the Dark Energy Survey (DES) is a 5000 sq. degree survey in the southern hemisphere, which is rapidly reducing the existing north-south asymmetry in the census of MW satellites and other stellar substructure. We use the first-year DES data down to previously unprobed photometric depths to search for stellar systems in the Galactic halo, therefore complementing the previous analysis of the same data carried out by our group earlier this year. Our search is based on a matched filter algorithm that produces stellar density maps consistent with stellar population models of various ages, metallicities, and distances over the surveymore » area. The most conspicuous density peaks in these maps have been identified automatically and ranked according to their significance and recurrence for different input models. We report the discovery of one additional stellar system besides those previously found by several authors using the same first-year DES data. The object is compact, and consistent with being dominated by an old and metal-poor population. DES J0034-4902 is found at high significance and appears in the DES images as a compact concentration of faint blue point sources at ~ 87 {kpc}.« less

  7. In the OSTI Collections: Dark Matter and Dark Energy | OSTI,...

    Office of Scientific and Technical Information (OSTI)

    Dark Matter and Dark Energy Recent observations of the universe, combined with Einstein's ... consists of entities very different from the matter and energy long familiar to us. ...

  8. Wide-Field Lensing Mass Maps from Dark Energy Survey Science...

    Office of Scientific and Technical Information (OSTI)

    Research Org: Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States) Sponsoring Org: USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25) Contributing Orgs: ...

  9. ObsTac: automated execution of Dark Energy Survey observing tactics...

    Office of Scientific and Technical Information (OSTI)

    Research Org: Fermi National Accelerator Laboratory (FNAL), Batavia, IL Sponsoring Org: USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25) Country of Publication: ...

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

    SciTech Connect (OSTI)

    Oguri, Masamune; 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 \

  11. DES J0454–4448: Discovery of the first luminous z ≥ 6 quasar from the Dark Energy Survey

    SciTech Connect (OSTI)

    Reed, S. L.

    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.

  12. DES J0454–4448: Discovery of the first luminous z ≥ 6 quasar from the Dark Energy Survey

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Reed, S. L.

    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 brightestmore » 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.« less

  13. OzDES multifibre spectroscopy for the Dark Energy Survey: First-year operation and results

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yuan, Fang; Plazas, A. A.; Lidman, C.; Davis, T. M.; Childress, M.; Abdalla, F. B.

    2015-07-29

    OzDES is a five-year, 100-night, spectroscopic survey on the Anglo-Australian Telescope, whose primary aim is to measure redshifts of approximately 2,500 Type Ia supernovae host galaxies over the redshift range 0.1 morehelp calibrate photometric redshifts. Here we present an overview of the OzDES program and our first-year results. Between Dec 2012 and Dec 2013, we observed over 10,000 objects and measured more than 6,000 redshifts. Our strategy of retargeting faint objects across many observing runs has allowed us to measure redshifts for galaxies as faint as mr = 25 mag. We outline our target selection and observing strategy, quantify the redshift success rate for different types of targets, and discuss the implications for our main science goals. Finally, we highlight a few interesting objects as examples of the fortuitous yet not totally unexpected discoveries that can come from such a large spectroscopic survey.less

  14. Observational Constraints on the Nature of the Dark Energy: First...

    Office of Scientific and Technical Information (OSTI)

    Observational Constraints on the Nature of the Dark Energy: First Cosmological Results From the ESSENCE Supernova Survey Citation Details In-Document Search Title: Observational...

  15. COLLOQUIUM: Probing the Accelerating Universe with the Dark Energy...

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

    MBG Auditorium, PPPL (284 cap.) COLLOQUIUM: Probing the Accelerating Universe with the Dark Energy Survey Dr. Joshua Frieman Fermilab and the University of Chicago Presentation: ...

  16. Galaxies in x-ray selected clusters and groups in Dark Energy Survey data. I. Stellar mass growth of bright central galaxies since z ~ 1.2

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

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

    2016-01-14

    Here, 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 ~ 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.

  17. New Camera Sheds Light on Dark Energy | Department of Energy

    Office of Environmental Management (EM)

    lies about 17,000 light years from Earth. | Photo by Dark Energy Survey Collaboration. ... Among the camera's jaw-dropping statistics, it has a weight of 4 to 5 tons and contains ...

  18. Fermilab | Science | Particle Physics | Dark matter and dark energy

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

    Dark matter and dark energy photo Visible matter makes up just 4 percent of the contents of the universe; the remaining 96 percent is made of dark matter and dark energy. Scientists discovered both by observing their cosmic effects but have yet to directly detect either. Fermilab experiments seek to uncover the mysteries of the dark universe. Scientists discovered dark matter by studying the behavior of neighboring galaxies and galaxy clusters. They could not explain the way the galaxies moved

  19. Optimizing New Dark Energy Experiments

    SciTech Connect (OSTI)

    Tyson, J. Anthony

    2013-08-26

    Next generation “Stage IV” dark energy experiments under design during this grant, and now under construction, will enable the determination of the properties of dark energy and dark matter to unprecedented precision using multiple complementary probes. The most pressing challenge in these experiments is the characterization and understanding of the systematic errors present within any given experimental configuration and the resulting impact on the accuracy of our constraints on dark energy physics. The DETF and the P5 panel in their reports recommended “Expanded support for ancillary measurements required for the long-term program and for projects that will improve our understanding and reduction of the dominant systematic measurement errors.” Looking forward to the next generation Stage IV experiments we have developed a program to address the most important potential systematic errors within these experiments. Using data from current facilities it has been feasible and timely to undertake a detailed investigation of the systematic errors. In this DOE grant we studied of the source and impact of the dominant systematic effects in dark energy measurements, and developed new analysis tools and techniques to minimize their impact. Progress under this grant is briefly reviewed in this technical report. This work was a necessary precursor to the coming generations of wide-deep probes of the nature of dark energy and dark matter. The research has already had an impact on improving the efficiencies of all Stage III and IV dark energy experiments.

  20. Berkeley Algorithms Help Researchers Understand Dark Energy

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

    Algorithms Help Researchers Understand Dark Energy Berkeley Algorithms Help Researchers Understand Dark Energy November 24, 2014 Contact: Linda Vu, +1 510 495 2402, lvu@lbl.gov ...

  1. Dark energy and dark matter from primordial QGP

    SciTech Connect (OSTI)

    Vaidya, Vaishali Upadhyaya, G. K.

    2015-07-31

    Coloured relics servived after hadronization might have given birth to dark matter and dark energy. Theoretical ideas to solve mystery of cosmic acceleration, its origin and its status with reference to recent past are of much interest and are being proposed by many workers. In the present paper, we present a critical review of work done to understand the earliest appearance of dark matter and dark energy in the scenario of primordial quark gluon plasma (QGP) phase after Big Bang.

  2. Dynamics of dark energy with a coupling to dark matter

    SciTech Connect (OSTI)

    Boehmer, Christian G.; Caldera-Cabral, Gabriela; Maartens, Roy; Lazkoz, Ruth

    2008-07-15

    Dark energy and dark matter are the dominant sources in the evolution of the late universe. They are currently only indirectly detected via their gravitational effects, and there could be a coupling between them without violating observational constraints. We investigate the background dynamics when dark energy is modeled as exponential quintessence and is coupled to dark matter via simple models of energy exchange. We introduce a new form of dark sector coupling, which leads to a more complicated dynamical phase space and has a better physical motivation than previous mathematically similar couplings.

  3. Voids and overdensities of coupled Dark Energy

    SciTech Connect (OSTI)

    Mainini, Roberto

    2009-04-15

    We investigate the clustering properties of dynamical Dark Energy even in association of a possible coupling between Dark Energy and Dark Matter. We find that within matter inhomogeneities, Dark Energy migth form voids as well as overdensity depending on how its background energy density evolves. Consequently and contrarily to what expected, Dark Energy fluctuations are found to be slightly suppressed if a coupling with Dark Matter is permitted. When considering density contrasts and scales typical of superclusters, voids and supervoids, perturbations amplitudes range from |{delta}{sub {phi}}| {approx} O(10{sup -6}) to |{delta}{sub {phi}}| {approx} O(10{sup -4}) indicating an almost homogeneous Dark Energy component.

  4. DOE Science Showcase - Dark Matter and Dark Energy | OSTI, US...

    Office of Scientific and Technical Information (OSTI)

    cosmos to you, Science.gov Saul Perlmutter, LBNL physicists and 2011 Nobel laureate, discusses Dark Energy and the Accelerating Universe, DOE Office of Science DOE Office of ...

  5. Unified dark energy-dark matter model with inverse quintessence

    SciTech Connect (OSTI)

    Ansoldi, Stefano; Guendelman, Eduardo I. E-mail: guendel@bgu.ac.il

    2013-05-01

    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.

  6. Final Technical Report: Discovering the Nature of Dark Energy...

    Office of Scientific and Technical Information (OSTI)

    Report: Discovering the Nature of Dark Energy: Towards Better Distances from Type Ia Supernovae Saurabh W. Jha 79 ASTRONOMY AND ASTROPHYSICS dark energy; supernovae; cosmology dark...

  7. Berkeley Algorithms Help Researchers Understand Dark Energy

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

    Algorithms Help Researchers Understand Dark Energy Berkeley Algorithms Help Researchers Understand Dark Energy November 24, 2014 Contact: Linda Vu, +1 510 495 2402, lvu@lbl.gov Scientists believe that dark energy-the mysterious force that is accelerating cosmic expansion-makes up about 70 percent of the mass and energy of the universe. But because they don't know what it is, they cannot observe it directly. To unlock the mystery of dark energy and its influence on the universe, researchers

  8. Dark matter and dark energy from quark bag model

    SciTech Connect (OSTI)

    Brilenkov, Maxim; Eingorn, Maxim; Jenkovszky, Laszlo; Zhuk, Alexander E-mail: maxim.eingorn@gmail.com E-mail: ai.zhuk2@gmail.com

    2013-08-01

    We calculate the present expansion of our Universe endowed with relict colored objects quarks and gluons that survived hadronization either as isolated islands of quark-gluon ''nuggets'' or spread uniformly in the Universe. In the first scenario, the QNs can play the role of dark matter. In the second scenario, we demonstrate that uniform colored objects can play the role of dark energy providing the late-time accelerating expansion of the Universe.

  9. Reconstruction of dark energy and expansion dynamics using Gaussian processes

    SciTech Connect (OSTI)

    Seikel, Marina; Clarkson, Chris; Smith, Mathew E-mail: chris.clarkson@uct.ac.za

    2012-06-01

    An important issue in cosmology is reconstructing the effective dark energy equation of state directly from observations. With few physically motivated models, future dark energy studies cannot only be based on constraining a dark energy parameter space, as the errors found depend strongly on the parametrisation considered. We present a new non-parametric approach to reconstructing the history of the expansion rate and dark energy using Gaussian Processes, which is a fully Bayesian approach for smoothing data. We present a pedagogical introduction to Gaussian Processes, and discuss how it can be used to robustly differentiate data in a suitable way. Using this method we show that the Dark Energy Survey - Supernova Survey (DES) can accurately recover a slowly evolving equation of state to σ{sub w} = ±0.05 (95% CL) at z = 0 and ±0.25 at z = 0.7, with a minimum error of ±0.025 at the sweet-spot at z ∼ 0.16, provided the other parameters of the model are known. Errors on the expansion history are an order of magnitude smaller, yet make no assumptions about dark energy whatsoever. A code for calculating functions and their first three derivatives using Gaussian processes has been developed and is available for download.

  10. DOE Science Showcase - Dark Matter and Dark Energy | OSTI, US Dept of

    Office of Scientific and Technical Information (OSTI)

    Energy Office of Scientific and Technical Information Dark Matter and Dark Energy The nature of dark energy or invisible energy is one of the universe's most compelling mysteries and its resolution is likely to completely change our understanding of matter, space, and time. For more information, see In the OSTI Collections: Dark Matter and Dark Energy, by Dr. William Watson, Physicist, OSTI staff. Gravitational lensing, or the warping of light around massive objects is one sign of dark

  11. Annealing a Follow-up Program: Improvement of the Dark Energy...

    Office of Scientific and Technical Information (OSTI)

    Galaxy Cluster Surveys Citation Details In-Document Search Title: Annealing a Follow-up Program: Improvement of the Dark Energy Figure of Merit for Optical Galaxy Cluster Surveys ...

  12. Saul Perlmutter, Distant Supernovae, Dark Energy, and the Accelerating...

    Office of Scientific and Technical Information (OSTI)

    Saul Perlmutter, Distant Supernovae, Dark Energy, and the Accelerating Expansion of the ... studies to determine the nature of dark energy.'1 'The accelerating expansion means that ...

  13. Neutrino mass, dark energy, and the linear growth factor (Journal...

    Office of Scientific and Technical Information (OSTI)

    dark energy, and the linear growth factor Citation Details In-Document Search Title: Neutrino mass, dark energy, and the linear growth factor We study the degeneracies between ...

  14. ASTRONOMY AND ASTROPHYSICS Dark Energy, Type Ia supernovae, radiative

    Office of Scientific and Technical Information (OSTI)

    of Oklahoma Univ. of Oklahoma 79 ASTRONOMY AND ASTROPHYSICS Dark Energy, Type Ia supernovae, radiative transfer, Dark Energy, Type Ia supernovae, radiative transfer, The...

  15. #LabChat Recap: What is Dark Energy

    Office of Energy Efficiency and Renewable Energy (EERE)

    The Dark Energy #LabChat on Oct. 25 yielded a lively discussion with three physicists about inflation, super symmetry, black holes and, of course, dark energy.

  16. Understanding the Fundamental Properties of Dark Matter and Dark Energy in Structure Formation and Cosmology

    SciTech Connect (OSTI)

    Ellis, Richard S.

    2012-09-30

    The program was concerned with developing and verifying the validity of observational methods for constraining the properties of dark matter and dark energy in the Universe.

  17. Evidence for Dark Energy | GE Global Research

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

    Has Evidence of Dark Energy Been Discovered? Click to email this to a friend (Opens in new window) Share on Facebook (Opens in new window) Click to share (Opens in new window) ...

  18. What We Know About Dark Energy From Supernovae

    ScienceCinema (OSTI)

    Filippenko, Alex [University of California, Berkeley, California, United States

    2010-01-08

    The measured distances of type Ia (white dwarf) supernovae as a function of redshift (z) have shown that the expansion of the Universe is currently accelerating, probably due to the presence of dark energy (X) having a negative pressure. Combining all of the data with existing results from large-scale structure surveys, we find a best fit for Omega M and Omega X of 0.28 and 0.72 (respectively), in excellent agreement with the values derived independently from WMAP measurements of the cosmic microwave background radiation. Thus far, the best-fit value for the dark energy equation-of-state parameter is -1, and its first derivative is consistent with zero, suggesting that the dark energy may indeed be Einstein's cosmological constant.

  19. Dark matter and dark energy: The critical questions (Conference...

    Office of Scientific and Technical Information (OSTI)

    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 ...

  20. Nonparametric reconstruction of the dark energy equation of state

    SciTech Connect (OSTI)

    Heitmann, Katrin; Holsclaw, Tracy; Alam, Ujjaini; Habib, Salman; Higdon, David; Sanso, Bruno; Lee, Herbie

    2009-01-01

    The major aim of ongoing and upcoming cosmological surveys is to unravel the nature of dark energy. In the absence of a compelling theory to test, a natural approach is to first attempt to characterize the nature of dark energy in detail, the hope being that this will lead to clues about the underlying fundamental theory. A major target in this characterization is the determination of the dynamical properties of the dark energy equation of state w. The discovery of a time variation in w(z) could then lead to insights about the dynamical origin of dark energy. This approach requires a robust and bias-free method for reconstructing w(z) from data, which does not rely on restrictive expansion schemes or assumed functional forms for w(z). We present a new non parametric reconstruction method for the dark energy equation of state based on Gaussian Process models. This method reliably captures nontrivial behavior of w(z) and provides controlled error bounds. We demollstrate the power of the method on different sets of simulated supernova data. The GP model approach is very easily extended to include diverse cosmological probes.

  1. The Next Dimension of Mapping the Universe: The Dark Energy Spectroscopic

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

    Instrument | Department of Energy Dimension of Mapping the Universe: The Dark Energy Spectroscopic Instrument The Next Dimension of Mapping the Universe: The Dark Energy Spectroscopic Instrument June 11, 2015 - 10:24am Addthis Zoomed-in image from the Dark Energy Camera of the barred spiral galaxy NGC 1365, in the Fornax cluster of galaxies, which lies about 60 million light years from Earth -- in other words, far, far away. | Photo courtesy of the Dark Energy Survey Collaboration. Zoomed-in

  2. Discovering the Nature of Dark Energy: Towards Better Distances...

    Office of Scientific and Technical Information (OSTI)

    the Nature of Dark Energy: Towards Better Distances from Type Ia Supernovae -- Final Technical Report Citation Details In-Document Search Title: Discovering the Nature of Dark ...

  3. Final Technical Report: Discovering the Nature of Dark Energy...

    Office of Scientific and Technical Information (OSTI)

    the Nature of Dark Energy: Towards Better Distances from Type Ia Supernovae Citation Details In-Document Search Title: Final Technical Report: Discovering the Nature of Dark ...

  4. Cooling the dark energy camera instrument

    SciTech Connect (OSTI)

    Schmitt, R.L.; Cease, H.; DePoy, D.; Diehl, H.T.; Estrada, J.; Flaugher, B.; Kuhlmann, S.; Onal, Birce; Stefanik, A.; /Fermilab

    2008-06-01

    DECam, camera for the Dark Energy Survey (DES), is undergoing general design and component testing. For an overview see DePoy, et al in these proceedings. For a description of the imager, see Cease, et al in these proceedings. The CCD instrument will be mounted at the prime focus of the CTIO Blanco 4m telescope. The instrument temperature will be 173K with a heat load of 113W. In similar applications, cooling CCD instruments at the prime focus has been accomplished by three general methods. Liquid nitrogen reservoirs have been constructed to operate in any orientation, pulse tube cryocoolers have been used when tilt angles are limited and Joule-Thompson or Stirling cryocoolers have been used with smaller heat loads. Gifford-MacMahon cooling has been used at the Cassegrain but not at the prime focus. For DES, the combined requirements of high heat load, temperature stability, low vibration, operation in any orientation, liquid nitrogen cost and limited space available led to the design of a pumped, closed loop, circulating nitrogen system. At zenith the instrument will be twelve meters above the pump/cryocooler station. This cooling system expected to have a 10,000 hour maintenance interval. This paper will describe the engineering basis including the thermal model, unbalanced forces, cooldown time, the single and two-phase flow model.

  5. Dark Energy: A Crisis for Fundamental Physics

    ScienceCinema (OSTI)

    Stubbs, Christopher [Harvard University, Cambridge, Massachusetts, USA

    2010-09-01

    Astrophysical observations provide robust evidence that our current picture of fundamental physics is incomplete. The discovery in 1998 that the expansion of the Universe is accelerating (apparently due to gravitational repulsion between regions of empty space!) presents us with a profound challenge, at the interface between gravity and quantum mechanics. This "Dark Energy" problem is arguably the most pressing open question in modern fundamental physics. The first talk will describe why the Dark Energy problem constitutes a crisis, with wide-reaching ramifications. One consequence is that we should probe our understanding of gravity at all accessible scales, and the second talk will present experiments and observations that are exploring this issue.

  6. Dark Energy Cam: Fermilab Expands Understanding of Expanding Universe |

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

    Department of Energy Dark Energy Cam: Fermilab Expands Understanding of Expanding Universe Dark Energy Cam: Fermilab Expands Understanding of Expanding Universe March 12, 2012 - 12:06pm Addthis Researchers at Fermi National Lab team stand beside the 570-megapixels, five-ton Dark Energy camera, which will be capable of measuring the expansion of the universe - and developing better models about how dark energy works. | Photo by Reidar Hahn, Fermi National Lab Researchers at Fermi National Lab

  7. Sub-horizon evolution of cold dark matter perturbations through dark matter-dark energy equivalence epoch

    SciTech Connect (OSTI)

    Piattella, O.F.; Martins, D.L.A.; Casarini, L. E-mail: denilsonluizm@gmail.com

    2014-10-01

    We consider a cosmological model of the late universe constituted by standard cold dark matter plus a dark energy component with constant equation of state w and constant effective speed of sound. By neglecting fluctuations in the dark energy component, we obtain an equation describing the evolution of sub-horizon cold dark matter perturbations through the epoch of dark matter-dark energy equality. We explore its analytic solutions and calculate an exact w-dependent correction for the dark matter growth function, logarithmic growth function and growth index parameter through the epoch considered. We test our analytic approximation with the numerical solution and find that the discrepancy is less than 1% for 0k = during the cosmic evolution up to a = 100.

  8. Simple implementation of general dark energy models

    SciTech Connect (OSTI)

    Bloomfield, Jolyon K.; Pearson, Jonathan A. E-mail: jonathan.pearson@durham.ac.uk

    2014-03-01

    We present a formalism for the numerical implementation of general theories of dark energy, combining the computational simplicity of the equation of state for perturbations approach with the generality of the effective field theory approach. An effective fluid description is employed, based on a general action describing single-scalar field models. The formalism is developed from first principles, and constructed keeping the goal of a simple implementation into CAMB in mind. Benefits of this approach include its straightforward implementation, the generality of the underlying theory, the fact that the evolved variables are physical quantities, and that model-independent phenomenological descriptions may be straightforwardly investigated. We hope this formulation will provide a powerful tool for the comparison of theoretical models of dark energy with observational data.

  9. Spectroscopic Needs for Imaging Dark Energy Experiments

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Newman, Jeffrey A.; Slosar, Anze; Abate, Alexandra; Abdalla, Filipe B.; Allam, Sahar; Allen, Steven W.; Ansari, Reza; Bailey, Stephen; Barkhouse, Wayne A.; Beers, Timothy C.; et al

    2015-03-15

    uncertainty in their mean redshift, RMS dispersion, etc. – rather than to make the moments themselves small. Calibration may be done with the same spectroscopic dataset used for training if that dataset is extremely high in redshift completeness (i.e., no populations of galaxies to be used in analyses are systematically missed). Accurate photo-z calibration is necessary for all imaging experiments; Requirements: If extremely low levels of systematic incompleteness (<~0.1%) are attained in training samples, the same datasets described above should be sufficient for calibration. However, existing deep spectroscopic surveys have failed to yield secure redshifts for 30–60% of targets, so that would require very large improvements over past experience. This incompleteness would be a limiting factor for training, but catastrophic for calibration. If <~0.1% incompleteness is not attainable, the best known option for calibration of photometric redshifts is to utilize cross-correlation statistics in some form. The most direct method for this uses cross-correlations between positions on the sky of bright objects of known spectroscopic redshift with the sample of objects that we wish to calibrate the redshift distribution for, measured as a function of spectroscopic z. For such a calibration, redshifts of ~100,000 objects over at least several hundred square degrees, spanning the full redshift range of the samples used for dark energy, would be necessary; and Options: The proposed BAO experiment eBOSS would provide sufficient spectroscopy for basic calibrations, particularly for ongoing and near-future imaging experiments. The planned DESI experiment would provide excellent calibration with redundant cross-checks, but will start after the conclusion of some imaging projects. An extension of DESI to the Southern hemisphere would provide the best possible calibration from cross-correlation methods for DES and LSST. We thus anticipate that our two primary needs for spectroscopy

  10. Spectroscopic Needs for Imaging Dark Energy Experiments

    SciTech Connect (OSTI)

    Newman, Jeffrey A.; Slosar, Anze; Abate, Alexandra; Abdalla, Filipe B.; Allam, Sahar; Allen, Steven W.; Ansari, Reza; Bailey, Stephen; Barkhouse, Wayne A.; Beers, Timothy C.; Blanton, Michael R.; Brodwin, Mark; Brownstein, Joel R.; Brunner, Robert J.; Carrasco-Kind, Matias; Cervantes-Cota, Jorge; Chisari, Nora Elisa; Colless, Matthew; Comparat, Johan; Coupon, Jean; Cheu, Elliott; Cunha, Carlos E.; de la Macorra, Alex; DellAntonio, Ian P.; Frye, Brenda L.; Gawiser, Eric J.; Gehrels, Neil; Grady, Kevin; Hagen, Alex; Hall, Patrick B.; Hearin, Andrew P.; Hildebrandt, Hendrik; Hirata, Christopher M.; Ho, Shirley; Honscheid, Klaus; Huterer, Dragan; Ivezic, Zeljko; Kneib, Jean -Paul; Kruk, Jeffrey W.; Lahav, Ofer; Mandelbaum, Rachel; Marshall, Jennifer L.; Matthews, Daniel J.; Menard, Brice; Miquel, Ramon; Moniez, Marc; Moos, H. W.; Moustakas, John; Papovich, Casey; Peacock, John A.; Park, Changbom; Rhodes, Jason; Sadeh, Iftach; Schmidt, Samuel J.; Stern, Daniel K.; Tyson, J. Anthony; von der Linden, Anja; Wechsler, Risa H.; Wood-Vasey, W. M.; Zentner, A.

    2015-03-15

    redshift, RMS dispersion, etc. rather than to make the moments themselves small. Calibration may be done with the same spectroscopic dataset used for training if that dataset is extremely high in redshift completeness (i.e., no populations of galaxies to be used in analyses are systematically missed). Accurate photo-z calibration is necessary for all imaging experiments; Requirements: If extremely low levels of systematic incompleteness (<~0.1%) are attained in training samples, the same datasets described above should be sufficient for calibration. However, existing deep spectroscopic surveys have failed to yield secure redshifts for 3060% of targets, so that would require very large improvements over past experience. This incompleteness would be a limiting factor for training, but catastrophic for calibration. If <~0.1% incompleteness is not attainable, the best known option for calibration of photometric redshifts is to utilize cross-correlation statistics in some form. The most direct method for this uses cross-correlations between positions on the sky of bright objects of known spectroscopic redshift with the sample of objects that we wish to calibrate the redshift distribution for, measured as a function of spectroscopic z. For such a calibration, redshifts of ~100,000 objects over at least several hundred square degrees, spanning the full redshift range of the samples used for dark energy, would be necessary; and Options: The proposed BAO experiment eBOSS would provide sufficient spectroscopy for basic calibrations, particularly for ongoing and near-future imaging experiments. The planned DESI experiment would provide excellent calibration with redundant cross-checks, but will start after the conclusion of some imaging projects. An extension of DESI to the Southern hemisphere would provide the best possible calibration from cross-correlation methods for DES and LSST. We thus anticipate that our two primary needs for spectroscopy training and calibration of

  11. Nonparametric reconstruction of the dark energy equation of state...

    Office of Scientific and Technical Information (OSTI)

    energy equation of state from diverse data sets Citation Details In-Document Search Title: Nonparametric reconstruction of the dark energy equation of state from diverse data ...

  12. DARK FLUID: A UNIFIED FRAMEWORK FOR MODIFIED NEWTONIAN DYNAMICS, DARK MATTER, AND DARK ENERGY

    SciTech Connect (OSTI)

    Zhao Hongsheng; Li Baojiu E-mail: b.li@damtp.cam.ac.u

    2010-03-20

    Empirical theories of dark matter (DM) like modified Newtonian dynamics (MOND) gravity and of dark energy (DE) like f(R) gravity were motivated by astronomical data. But could these theories be branches rooted from a more general and hence generic framework? Here we propose a very generic Lagrangian of such a framework based on simple dimensional analysis and covariant symmetry requirements, and explore various outcomes in a top-down fashion. The desired effects of quintessence plus cold DM particle fields or MOND-like scalar field(s) are shown to be largely achievable by one vector field only. Our framework preserves the covariant formulation of general relativity, but allows the expanding physical metric to be bent by a single new species of dark fluid flowing in spacetime. Its non-uniform stress tensor and current vector are simple functions of a vector field with variable norm, not coupled with the baryonic fluid and the four-vector potential of the photon fluid. The dark fluid framework generically branches into a continuous spectrum of theories with DE and DM effects, including the f(R) gravity, tensor-vector-scalar-like theories, Einstein-Aether, and nuLAMBDA theories as limiting cases. When the vector field degenerates into a pure scalar field, we obtain the physics for quintessence. Choices of parameters can be made to pass Big Bang nucleosynthesis, parameterized post-Newtonian, and causality constraints. In this broad setting we emphasize the non-constant dynamical field behind the cosmological constant effect, and highlight plausible corrections beyond the classical MOND predictions.

  13. Interacting vacuum energy in the dark sector

    SciTech Connect (OSTI)

    Chimento, L. P.; Carneiro, S.

    2015-03-26

    We analyse three cosmological scenarios with interaction in the dark sector, which are particular cases of a general expression for the energy flux from vacuum to matter. In the first case the interaction leads to a transition from an unstable de Sitter phase to a radiation dominated universe, avoiding in this way the initial singularity. In the second case the interaction gives rise to a slow-roll power-law inflation. Finally, the third scenario is a concordance model for the late-time universe, with the vacuum term decaying into cold dark matter. We identify the physics behind these forms of interaction and show that they can be described as particular types of the modified Chaplygin gas.

  14. The coincidence problem and interacting holographic dark energy

    SciTech Connect (OSTI)

    Karwan, Khamphee

    2008-05-15

    We study the dynamical behaviour of the interacting holographic dark energy model whose interaction term is Q = 3H({lambda}{sub d}{rho}{sub d}+{lambda}{sub c}{rho}{sub c}), where {rho}{sub d} and {rho}{sub c} are the energy densities of dark energy and cold dark matter respectively. To satisfy the observational constraints from type Ia supernovae, the cosmic microwave background shift parameter and baryon acoustic oscillation measurements, if {lambda}{sub c} = {lambda}{sub d} or {lambda}{sub d},{lambda}{sub c}>0, the cosmic evolution will only reach the attractor in the future and the ratio {rho}{sub c}/{rho}{sub d} cannot be slowly varying at present. Since the cosmic attractor can be reached in the future even when the present values of the cosmological parameters do not satisfy the observational constraints, the coincidence problem is not really alleviated in this case. However, if {lambda}{sub c}{ne}{lambda}{sub d} and they are allowed to be negative, the ratio {rho}{sub c}/{rho}{sub d} can be slowly varying at present and the cosmic attractor can be reached near the present epoch. Hence, the alleviation of the coincidence problem is attainable in this case. The alleviation of the coincidence problem in this case is still attainable when confronting this model with Sloan Digital Sky Survey data.

  15. Non-adiabatic perturbations in Ricci dark energy model

    SciTech Connect (OSTI)

    Karwan, Khamphee; Thitapura, Thiti E-mail: nanodsci2523@hotmail.com

    2012-01-01

    We show that the non-adiabatic perturbations between Ricci dark energy and matter can grow both on superhorizon and subhorizon scales, and these non-adiabatic perturbations on subhorizon scales can lead to instability in this dark energy model. The rapidly growing non-adiabatic modes on subhorizon scales always occur when the equation of state parameter of dark energy starts to drop towards -1 near the end of matter era, except that the parameter α of Ricci dark energy equals to 1/2. In the case where α = 1/2, the rapidly growing non-adiabatic modes disappear when the perturbations in dark energy and matter are adiabatic initially. However, an adiabaticity between dark energy and matter perturbations at early time implies a non-adiabaticity between matter and radiation, this can influence the ordinary Sachs-Wolfe (OSW) effect. Since the amount of Ricci dark energy is not small during matter domination, the integrated Sachs-Wolfe (ISW) effect is greatly modified by density perturbations of dark energy, leading to a wrong shape of CMB power spectrum. The instability in Ricci dark energy is difficult to be alleviated if the effects of coupling between baryon and photon on dark energy perturbations are included.

  16. Structure formation in inhomogeneous Early Dark Energy models

    SciTech Connect (OSTI)

    Batista, R.C.; Pace, F. E-mail: francesco.pace@port.ac.uk

    2013-06-01

    We study the impact of Early Dark Energy fluctuations in the linear and non-linear regimes of structure formation. In these models the energy density of dark energy is non-negligible at high redshifts and the fluctuations in the dark energy component can have the same order of magnitude of dark matter fluctuations. Since two basic approximations usually taken in the standard scenario of quintessence models, that both dark energy density during the matter dominated period and dark energy fluctuations on small scales are negligible, are not valid in such models, we first study approximate analytical solutions for dark matter and dark energy perturbations in the linear regime. This study is helpful to find consistent initial conditions for the system of equations and to analytically understand the effects of Early Dark Energy and its fluctuations, which are also verified numerically. In the linear regime we compute the matter growth and variation of the gravitational potential associated with the Integrated Sachs-Wolf effect, showing that these observables present important modifications due to Early Dark Energy fluctuations, though making them more similar to the ΛCDM model. We also make use of the Spherical Collapse model to study the influence of Early Dark Energy fluctuations in the nonlinear regime of structure formation, especially on δ{sub c} parameter, and their contribution to the halo mass, which we show can be of the order of 10%. We finally compute how the number density of halos is modified in comparison to the ΛCDM model and address the problem of how to correct the mass function in order to take into account the contribution of clustered dark energy. We conclude that the inhomogeneous Early Dark Energy models are more similar to the ΛCDM model than its homogeneous counterparts.

  17. Aetherizing Lambda: Barotropic fluids as dark energy

    SciTech Connect (OSTI)

    Linder, Eric V.; Scherrer, Robert J.

    2009-07-15

    We examine the class of barotropic fluid models of dark energy, in which the pressure is an explicit function of the density, p=f({rho}). Through general physical considerations we constrain the asymptotic past and future behaviors and show that this class is equivalent to the sum of a cosmological constant and a decelerating perfect fluid, or 'aether', with w{sub AE}{>=}0. Barotropic models give substantially disjoint predictions from quintessence, except in the limit of {lambda}CDM. They are also interesting in that they simultaneously can ameliorate the coincidence problem and yet 'predict' a value of w{approx_equal}-1.

  18. The growth of structure in interacting dark energy models

    SciTech Connect (OSTI)

    Caldera-Cabral, Gabriela; Maartens, Roy; Schaefer, Bjoern Malte E-mail: roy.maartens@port.ac.uk

    2009-07-01

    If dark energy interacts with dark matter, there is a change in the background evolution of the universe, since the dark matter density no longer evolves as a{sup ?3}. In addition, the non-gravitational interaction affects the growth of structure. In principle, these changes allow us to detect and constrain an interaction in the dark sector. Here we investigate the growth factor and the weak lensing signal for a new class of interacting dark energy models. In these models, the interaction generalises the simple cases where one dark fluid decays into the other. In order to calculate the effect on structure formation, we perform a careful analysis of the perturbed interaction and its effect on peculiar velocities. Assuming a normalization to today's values of dark matter density and overdensity, the signal of the interaction is an enhancement (suppression) of both the growth factor and the lensing power, when the energy transfer in the background is from dark matter to dark energy (dark energy to dark matter)

  19. Final Technical Report: Discovering the Nature of Dark Energy: Towards

    Office of Scientific and Technical Information (OSTI)

    Better Distances from Type Ia Supernovae (Technical Report) | SciTech Connect Final Technical Report: Discovering the Nature of Dark Energy: Towards Better Distances from Type Ia Supernovae Citation Details In-Document Search Title: Final Technical Report: Discovering the Nature of Dark Energy: Towards Better Distances from Type Ia Supernovae The final technical report from the project "Discovering the Nature of Dark Energy: Towards Better Distances from Type Ia Supernovae" led at

  20. MAPPING THE DARK MATTER WITH POLARIZED RADIO SURVEYS

    SciTech Connect (OSTI)

    Brown, Michael L.; Battye, Richard A.

    2011-07-01

    In a recent paper, we proposed the use of integrated polarization measurements of background galaxies in radio weak gravitational lensing surveys and investigated the potential impact on the statistical measurement of cosmic shear. Here we extend this idea to reconstruct maps of the projected dark matter distribution or lensing convergence field. The addition of polarization can, in principle, greatly reduce shape noise due to the intrinsic dispersion in galaxy ellipticities. We show that maps reconstructed using this technique in the radio band can be competitive with those derived using standard lensing techniques which make use of many more galaxies. In addition, since the reconstruction noise is uncorrelated between these standard techniques and the polarization technique, their comparison can serve as a powerful check for systematics and their combination can reduce noise further. We examine the convergence reconstruction which could be achieved with two forthcoming facilities: (1) a deep survey, covering 1.75 deg{sup 2} using the e-MERLIN instrument currently being commissioned in the UK and (2) the high-resolution, deep wide-field surveys which will eventually be conducted with the Square Kilometre Array.

  1. The effective field theory of dark energy

    SciTech Connect (OSTI)

    Gubitosi, Giulia; Vernizzi, Filippo; Piazza, Federico E-mail: fpiazza@apc.univ-paris7.fr

    2013-02-01

    We propose a universal description of dark energy and modified gravity that includes all single-field models. By extending a formalism previously applied to inflation, we consider the metric universally coupled to matter fields and we write in terms of it the most general unitary gauge action consistent with the residual unbroken symmetries of spatial diffeomorphisms. Our action is particularly suited for cosmological perturbation theory: the background evolution depends on only three operators. All other operators start at least at quadratic order in the perturbations and their effects can be studied independently and systematically. In particular, we focus on the properties of a few operators which appear in non-minimally coupled scalar-tensor gravity and galileon theories. In this context, we study the mixing between gravity and the scalar degree of freedom. We assess the quantum and classical stability, derive the speed of sound of fluctuations and the renormalization of the Newton constant. The scalar can always be de-mixed from gravity at quadratic order in the perturbations, but not necessarily through a conformal rescaling of the metric. We show how to express covariant field-operators in our formalism and give several explicit examples of dark energy and modified gravity models in our language. Finally, we discuss the relation with the covariant EFT methods recently appeared in the literature.

  2. Stable gravastars of anisotropic dark energy

    SciTech Connect (OSTI)

    Chan, R.; Silva, M.F.A. da; Rocha, P.; Wang, Anzhong E-mail: mfasnic@gmail.com E-mail: anzhong_wang@baylor.edu

    2009-03-15

    Dynamical models of prototype gravastars made of anisotropic dark energy fluid are constructed, in which an infinitely thin spherical shell of a perfect fluid with the equation of state p = (1-{gamma}){sigma} divides the whole spacetime into two regions, the internal region is filled with an anisotropic dark energy fluid, and the external region is the Schwarzschild. It is found that in some cases the models represent the ''bounded excursion'' stable gravastars, where the thin shell is oscillating between two finite radii, while in other cases they collapse until the formation of black holes or normal stars. In the phase space, the region for the ''bounded excursion'' gravastars is very small in comparison to that of black holes, but not empty, as found in our previous papers. Therefore, although the existence of gravastars can not be completely excluded from current analysis, the opposite is not possible either, that is, even if gravastars exist, they do not exclude the existence of black holes.

  3. In the OSTI Collections: Dark Matter and Dark Energy | OSTI, US Dept of

    Office of Scientific and Technical Information (OSTI)

    Energy Office of Scientific and Technical Information Dark Matter and Dark Energy Recent observations of the universe, combined with Einstein's theory of general relativity, indicate that most of the universe consists of entities very different from the matter and energy long familiar to us. These previously unknown entities are beginning to be explored on several fronts, many through Department of Energy sponsorship. Albert Einstein's theory of relativity describes space and time as

  4. Final Technical Report: Discovering the Nature of Dark Energy...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Final Technical Report: Discovering the Nature of Dark Energy: Towards Better Distances from Type Ia Supernovae Citation Details In-Document Search Title: Final...

  5. Optimizing New Dark Energy Experiments - Final Scientific Report

    SciTech Connect (OSTI)

    Jeffrey A. Newman

    2012-06-08

    This is the final scientific report for the University of Pittsburgh portion of the collaborative grant, 'Optimizing New Dark Energy Experiments'

  6. Discovering the Nature of Dark Energy: Towards Better Distances...

    Office of Scientific and Technical Information (OSTI)

    Discovering the Nature of Dark Energy: Towards Better Distances from Type Ia Supernovae -- Final Technical Report Filippenko, Alexei Vladimir Univ. California, Berkeley 79...

  7. 2002 Manufacturing Energy Consumption Survey - User Needs Survey

    U.S. Energy Information Administration (EIA) Indexed Site

    2002 Manufacturing Energy Consumption Survey: User-Needs Survey View current results. We need your help in designing the next Energy Consumption Survey (MECS) As our valued...

  8. Chameleon dark energy models with characteristic signatures

    SciTech Connect (OSTI)

    Gannouji, Radouane; Moraes, Bruno; Polarski, David; Mota, David F.; Winther, Hans A.; Tsujikawa, Shinji

    2010-12-15

    In chameleon dark energy models, local gravity constraints tend to rule out parameters in which observable cosmological signatures can be found. We study viable chameleon potentials consistent with a number of recent observational and experimental bounds. A novel chameleon field potential, motivated by f(R) gravity, is constructed where observable cosmological signatures are present both at the background evolution and in the growth rate of the perturbations. We study the evolution of matter density perturbations on low redshifts for this potential and show that the growth index today {gamma}{sub 0} can have significant dispersion on scales relevant for large scale structures. The values of {gamma}{sub 0} can be even smaller than 0.2 with large variations of {gamma} on very low redshifts for the model parameters constrained by local gravity tests. This gives a possibility to clearly distinguish these chameleon models from the {Lambda}-cold-dark-matter ({Lambda}CDM) model in future high-precision observations.

  9. IRT Surveys | Open Energy Information

    Open Energy Info (EERE)

    consulting in building thermographers and thermal imaging allowing to detect energy loss and increase of energy efficiency. References: IRT Surveys1 This article is a stub....

  10. Calibration Monitor for Dark Energy Experiments

    SciTech Connect (OSTI)

    Kaiser, M. E.

    2009-11-23

    The goal of this program was to design, build, test, and characterize a flight qualified calibration source and monitor for a Dark Energy related experiment: ACCESS - 'Absolute Color Calibration Experiment for Standard Stars'. This calibration source, the On-board Calibration Monitor (OCM), is a key component of our ACCESS spectrophotometric calibration program. The OCM will be flown as part of the ACCESS sub-orbital rocket payload in addition to monitoring instrument sensitivity on the ground. The objective of the OCM is to minimize systematic errors associated with any potential changes in the ACCESS instrument sensitivity. Importantly, the OCM will be used to monitor instrument sensitivity immediately after astronomical observations while the instrument payload is parachuting to the ground. Through monitoring, we can detect, track, characterize, and thus correct for any changes in instrument senstivity over the proposed 5-year duration of the assembled and calibrated instrument.

  11. 2014 Manufacturing Energy Consumption Survey

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

    U S C E N S U S B U R E A U 2014 Manufacturing Energy Consumption Survey Sponsored by the Energy Information Administration U.S. Department of Energy Administered and Compiled by ...

  12. NASA and DOE Collaborate on Dark Energy Research | Department of Energy

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

    NASA and DOE Collaborate on Dark Energy Research NASA and DOE Collaborate on Dark Energy Research November 19, 2008 - 4:58pm Addthis WASHINGTON, DC -- NASA and the U.S. Department of Energy (DOE) have signed a memorandum of understanding for the implementation of the Joint Dark Energy Mission, or JDEM. The mission will feature the first space-based observatory designed specifically to understand the nature of dark energy. Dark energy is a form of energy that pervades and dominates the universe.

  13. #LabChat: What is Dark Energy? Oct 25 at 2pm ET | Department of Energy

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

    What is Dark Energy? Oct 25 at 2pm ET #LabChat: What is Dark Energy? Oct 25 at 2pm ET October 23, 2012 - 3:03pm Q&A #LabChat Oct 25, 2 pm ET | These physicists are using advanced telescopes and cameras to look for proof of dark energy. Ask them your questions. Ask Us Addthis What is dark energy? Learn about the force we think accounts for three-quarters of the mass and energy in the known universe. What is dark energy? Learn about the force we think accounts for three-quarters of the mass

  14. Digital Surveying Directional Surveying Specialists | Open Energy...

    Open Energy Info (EERE)

    Surveying Specialists Jump to: navigation, search OpenEI Reference LibraryAdd to library Web Site: Digital Surveying Directional Surveying Specialists Author Directional Surveying...

  15. Cosmological viability conditions for f(T) dark energy models

    SciTech Connect (OSTI)

    Setare, M.R.; Mohammadipour, N. E-mail: N.Mohammadipour@uok.ac.ir

    2012-11-01

    Recently f(T) modified teleparallel gravity where T is the torsion scalar has been proposed as the natural gravitational alternative for dark energy. We perform a detailed dynamical analysis of these models and find conditions for the cosmological viability of f(T) dark energy models as geometrical constraints on the derivatives of these models. We show that in the phase space exists two cosmologically viable trajectory which (i) The universe would start from an unstable radiation point, then pass a saddle standard matter point which is followed by accelerated expansion de sitter point. (ii) The universe starts from a saddle radiation epoch, then falls onto the stable matter era and the system can not evolve to the dark energy dominated epoch. Finally, for a number of f(T) dark energy models were proposed in the more literature, the viability conditions are investigated.

  16. Dark Energy: A Universe Out of Control Nicholas B. Suntzeff....

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

    Dark Energy: A Universe Out of Control Nicholas B. Suntzeff. Ph. D. MitchellHeepMunnerlyn Professor of Observational Astronomy Texas A&M University Nobel Prize in Physics 2011 ...

  17. Interacting agegraphic quintessence dark energy in non-flat universe

    SciTech Connect (OSTI)

    Sheykhi, A.; Bagheri, A.; Yazdanpanah, M.M. E-mail: ali.bagheri25@yahoo.com

    2010-09-01

    We establish a correspondence between interacting agegraphic dark energy model and the quintessence scalar field in a non-flat universe. We demonstrate that the agegraphic evolution of the universe can be described completely by a single quintessence scalar field. We also reconstruct the potential of the interacting agegraphic quintessence dark energy as well as the dynamics of the quintessence scalar field which describe the quintessence cosmology.

  18. New Light on Dark Energy (LBNL Science at the Theater)

    ScienceCinema (OSTI)

    Linder, Eric; Ho, Shirly; Aldering, Greg; Fraiknoi, Andrew

    2011-06-08

    A panel of Lab scientists ? including Eric Linder, Shirly Ho, and Greg Aldering ? along with Andrew Fraiknoi, the Bay Area's most popular astronomy explainer, gathered at the Berkeley Repertory Theatre on Monday, April 25, 2011, for a discussion about "New Light on Dark Energy." Topics will include hunting down Type 1a supernovae, measuring the universe using baryon oscillation, and whether dark energy is the true driver of the universe.

  19. Transportation Energy Consumption Surveys

    U.S. Energy Information Administration (EIA) Indexed Site

    Electricity Hydropower Biofuels: Ethanol & Biodiesel Wind Geothermal Solar Energy in Brief How much U.S. electricity is generated from renewable energy?...

  20. Chinese Geological Survey | Open Energy Information

    Open Energy Info (EERE)

    Chinese Geological Survey Jump to: navigation, search Name: Chinese Geological Survey Place: China Sector: Geothermal energy Product: Chinese body which is involved in surveys of...

  1. Commercial Buildings Energy Consumption Survey (CBECS) - Analysis...

    Gasoline and Diesel Fuel Update (EIA)

    The Commercial Buildings Energy Consumption Survey (CBECS) project cycle spans at least ... Data collection for the 2012 Commercial Buildings Energy Consumption Survey (CBECS) took ...

  2. Wind energy: An engineering survey

    SciTech Connect (OSTI)

    Nahas, M.N.; Mohamad, A.S.; Akyurt, M.; El-Kalay, A.K.

    1987-01-01

    This paper presents an extensive survey of literature about wind energy and wind machines, their design and their applications. The paper intends to provide those who plan for energy policy with thorough information about this renewable type of energy and the available machines that convert wind energy into useful mechanical or electrical work. The machines which are available at present range from the simple Savonius rotor to the powerful multi-blade windmills. The advantages and shortcomings of all types are discussed here.

  3. DESI and other Dark Energy experiments in the era of neutrino mass measurements

    SciTech Connect (OSTI)

    Font-Ribera, Andreu; McDonald, Patrick; Mostek, Nick; Reid, Beth A.; Seo, Hee-Jong; Slosar, Ane E-mail: PVMcDonald@lbl.gov E-mail: BAReid@lbl.gov E-mail: anze@bnl.gov

    2014-05-01

    We present Fisher matrix projections for future cosmological parameter measurements, including neutrino masses, Dark Energy, curvature, modified gravity, the inflationary perturbation spectrum, non-Gaussianity, and dark radiation. We focus on DESI and generally redshift surveys (BOSS, HETDEX, eBOSS, Euclid, and WFIRST), but also include CMB (Planck) and weak gravitational lensing (DES and LSST) constraints. The goal is to present a consistent set of projections, for concrete experiments, which are otherwise scattered throughout many papers and proposals. We include neutrino mass as a free parameter in most projections, as it will inevitably be relevant DESI and other experiments can measure the sum of neutrino masses to ? 0.02 eV or better, while the minimum possible sum is ? 0.06 eV. We note that constraints on Dark Energy are significantly degraded by the presence of neutrino mass uncertainty, especially when using galaxy clustering only as a probe of the BAO distance scale (because this introduces additional uncertainty in the background evolution after the CMB epoch). Using broadband galaxy power becomes relatively more powerful, and bigger gains are achieved by combining lensing survey constraints with redshift survey constraints. We do not try to be especially innovative, e.g., with complex treatments of potential systematic errors these projections are intended as a straightforward baseline for comparison to more detailed analyses.

  4. Growth of Cosmic Structure: Probing Dark Energy Beyond Expansion

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Huterer, Dragan; Kirkby, David; Bean, Rachel; Connolly, Andrew; Dawson, Kyle; Dodelson, Scott; Evrard, August; Jain, Bhuvnesh; Jarvis, Michael; Linder, Eric; et al

    2014-03-15

    The quantity and quality of cosmic structure observations have greatly accelerated in recent years, and further leaps forward will be facilitated by imminent projects. These will enable us to map the evolution of dark and baryonic matter density fluctuations over cosmic history. The way that these fluctuations vary over space and time is sensitive to several pieces of fundamental physics: the primordial perturbations generated by GUT-scale physics; neutrino masses and interactions; the nature of dark matter and dark energy. We focus on the last of these here: the ways that combining probes of growth with those of the cosmic expansionmore » such as distance-redshift relations will pin down the mechanism driving the acceleration of the Universe.« less

  5. Improved Dark Energy Constraints From ~ 100 New CfA Supernova...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Improved Dark Energy Constraints From 100 New CfA Supernova Type Ia Light Curves Citation Details In-Document Search Title: Improved Dark Energy Constraints From ...

  6. High-Powered Dark Energy Camera Can See Billions of Light Years...

    Energy Savers [EERE]

    High-Powered Dark Energy Camera Can See Billions of Light Years Away High-Powered Dark Energy Camera Can See Billions of Light Years Away August 21, 2014 - 10:19am Addthis Stars ...

  7. Discovery of Dark Energy Ushered in a New Era in Computational...

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

    Discovery of Dark Energy Ushered in a New Era in Computational Cosmology Discovery of Dark Energy Ushered in a New Era in Computational Cosmology October 4, 2011 John Hules, ...

  8. Saul Perlmutter, Distant Supernovae, Dark Energy, and the Accelerating

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

    Expansion of the Universe Saul Perlmutter, Distant Supernovae, Dark Energy, and the Accelerating Expansion of the Universe Resources with Additional Information * Awards Saul Perlmutter Photo Courtesy of Lawrence Berkeley National Laboratory 'Saul Perlmutter, an astrophysicist at the U.S. Department of Energy's Lawrence Berkeley National Laboratory and a professor of physics at the University of California at Berkeley, has won the 2011 Nobel Prize in Physics "for the discovery of the

  9. Fine Structure of Dark Energy and New Physics

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Jejjala, Vishnu; Kavic, Michael; Minic, Djordje

    2007-01-01

    Following our recent work on the cosmological constant problem, in this letter we make a specific proposal regarding the fine structure (i.e., the spectrum) of dark energy. The proposal is motivated by a deep analogy between the blackbody radiation problem, which led to the development of quantum theory, and the cosmological constant problem, for which we have recently argued calls for a conceptual extension of the quantum theory. We argue that the fine structure of dark energy is governed by a Wien distribution, indicating its dual quantum and classical nature. We discuss observational consequences of such a picture of darkmore » energy and constrain the distribution function.« less

  10. Testing coupled dark energy with large scale structure observation

    SciTech Connect (OSTI)

    Yang, Weiqiang; Xu, Lixin, E-mail: d11102004@mail.dlut.edu.cn, E-mail: lxxu@dlut.edu.cn [Institute of Theoretical Physics, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian, 116024 (China)

    2014-08-01

    The coupling between the dark components provides a new approach to mitigate the coincidence problem of cosmological standard model. In this paper, dark energy is treated as a fluid with a constant equation of state, whose coupling with dark matter is Q-bar =3H?{sub x}?-bar {sub x}. In the frame of dark energy, we derive the evolution equations for the density and velocity perturbations. According to the Markov Chain Monte Carlo method, we constrain the model by currently available cosmic observations which include cosmic microwave background radiation, baryon acoustic oscillation, type Ia supernovae, and f?{sub 8}(z) data points from redshift-space distortion. The results show the interaction rate in ? regions: ?{sub x}=0.00328{sub -0.00328-0.00328-0.00328}{sup +0.000736+0.00549+0.00816}, which means that the recently cosmic observations favor a small interaction rate which is up to the order of 10{sup -2}, meanwhile, the measurement of redshift-space distortion could rule out the large interaction rate in the ? region.

  11. On the internal consistency of holographic dark energy models

    SciTech Connect (OSTI)

    Horvat, R

    2008-10-15

    Holographic dark energy (HDE) models, underpinned by an effective quantum field theory (QFT) with a manifest UV/IR connection, have become convincing candidates for providing an explanation of the dark energy in the universe. On the other hand, the maximum number of quantum states that a conventional QFT for a box of size L is capable of describing relates to those boxes which are on the brink of experiencing a sudden collapse to a black hole. Another restriction on the underlying QFT is that the UV cut-off, which cannot be chosen independently of the IR cut-off and therefore becomes a function of time in a cosmological setting, should stay the largest energy scale even in the standard cosmological epochs preceding a dark energy dominated one. We show that, irrespective of whether one deals with the saturated form of HDE or takes a certain degree of non-saturation in the past, the above restrictions cannot be met in a radiation dominated universe, an epoch in the history of the universe which is expected to be perfectly describable within conventional QFT.

  12. No-Go Theorem for k-Essence Dark Energy

    SciTech Connect (OSTI)

    Bonvin, Camille; Caprini, Chiara; Durrer, Ruth

    2006-08-25

    We demonstrate that if k-essence can solve the coincidence problem and play the role of dark energy in the Universe, the fluctuations of the field have to propagate superluminally at some stage. We argue that this implies that successful k-essence models violate causality. It is not possible to define a time ordered succession of events in a Lorentz invariant way. Therefore, k-essence cannot arise as a low energy effective field theory of a causal, consistent high energy theory.

  13. Constraining dark energy through the stability of cosmic structures

    SciTech Connect (OSTI)

    Pavlidou, V.; Tetradis, N.; Tomaras, T.N. E-mail: ntetrad@phys.uoa.gr

    2014-05-01

    For a general dark-energy equation of state, we estimate the maximum possible radius of massive structures that are not destabilized by the acceleration of the cosmological expansion. A comparison with known stable structures constrains the equation of state. The robustness of the constraint can be enhanced through the accumulation of additional astrophysical data and a better understanding of the dynamics of bound cosmic structures.

  14. Residential Energy Consumption Survey: Quality Profile

    SciTech Connect (OSTI)

    1996-03-01

    The Residential Energy Consumption Survey (RECS) is a periodic national survey that provides timely information about energy consumption and expenditures of U.S. households and about energy-related characteristics of housing units. The survey was first conducted in 1978 as the National Interim Energy Consumption Survey (NIECS), and the 1979 survey was called the Household Screener Survey. From 1980 through 1982 RECS was conducted annually. The next RECS was fielded in 1984, and since then, the survey has been undertaken at 3-year intervals. The most recent RECS was conducted in 1993.

  15. Fermilab | Newsroom | Press Releases | August 17, 2015: Dark...

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

    2015 FOR IMMEDIATE RELEASE Dark Energy Survey finds more celestial neighbors New dwarf galaxy candidates could mean our sky is more crowded than we thought photo The Dark Energy...

  16. Inflation and dark energy from the Brans-Dicke theory

    SciTech Connect (OSTI)

    Artymowski, Michał; Lalak, Zygmunt; Lewicki, Marek

    2015-06-17

    We consider the Brans-Dicke theory motivated by the f(R)=R+αR{sup n}−βR{sup 2−n} model to obtain a stable minimum of the Einstein frame scalar potential of the Brans-Dicke field. As a result we have obtained an inflationary scalar potential with non-zero value of residual vacuum energy, which may be a source of dark energy. In addition we discuss the probability of quantum tunnelling from the minimum of the potential. Our results can be easily consistent with PLANCK or BICEP2 data for appropriate choices of the value of n and ω.

  17. A Terrestrial Search for Dark Contents of the Vacuum, Such as Dark Energy, Using Atom Interferometry

    SciTech Connect (OSTI)

    Adler, Ronald J.; Muller, Holger; Perl, Martin L.; /KIPAC, Menlo Park /SLAC

    2012-06-11

    We describe the theory and first experimental work on our concept for searching on earth for the presence of dark contents of the vacuum (DCV) using atom interferometry. Specifically, we have in mind any DCV that has not yet been detected on a laboratory scale, but which might manifest itself as dark energy on the cosmological scale. The experimental method uses two atom interferometers to cancel the effect of earth's gravity and diverse noise sources. It depends upon two assumptions: first, that the DCV possesses some space inhomogeneity in density, and second that it exerts a sufficiently strong nongravitational force on matter. The motion of the apparatus through the DCV should then lead to an irregular variation in the detected matter-wave phase shift. We discuss the nature of this signal and note the problem of distinguishing it from instrumental noise. We also discuss the relation of our experiment to what might be learned by studying the noise in gravitational wave detectors such as LIGO. The paper concludes with a projection that a future search of this nature might be carried out using an atom interferometer in an orbiting satellite. The laboratory apparatus is now being constructed.

  18. Residential Energy Consumption Survey (RECS) - Data - U.S. Energy...

    Gasoline and Diesel Fuel Update (EIA)

    Energy Usage The 1997 Residential Energy Consumption Survey (RECS) collected household energy data for the four most populated States: California, Florida, New York, and Texas. ...

  19. Cosmic acceleration without dark energy: background tests and thermodynamic analysis

    SciTech Connect (OSTI)

    Lima, J.A.S.; Graef, L.L.; Pavn, D.; Basilakos, Spyros E-mail: leilagraef@usp.br E-mail: svasil@academyofathens.gr

    2014-10-01

    A cosmic scenario with gravitationally induced particle creation is proposed. In this model the Universe evolves from an early to a late time de Sitter era, with the recent accelerating phase driven only by the negative creation pressure associated with the cold dark matter component. The model can be interpreted as an attempt to reduce the so-called cosmic sector (dark matter plus dark energy) and relate the two cosmic accelerating phases (early and late time de Sitter expansions). A detailed thermodynamic analysis including possible quantum corrections is also carried out. For a very wide range of the free parameters, it is found that the model presents the expected behavior of an ordinary macroscopic system in the sense that it approaches thermodynamic equilibrium in the long run (i.e., as it nears the second de Sitter phase). Moreover, an upper bound is found for the GibbonsHawking temperature of the primordial de Sitter phase. Finally, when confronted with the recent observational data, the current 'quasi'-de Sitter era, as predicted by the model, is seen to pass very comfortably the cosmic background tests.

  20. Dark Energy and Cosmic Sound Daniel Eisenstein Harvard University

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

    Dark Energy and Cosmic Sound Daniel Eisenstein Harvard University May 27, 2015 4:00 p.m. (coffee @ 3:30) Discuss how the acoustic oscillations that propagate in the photon- baryon fluid during the first million years of the Universe provide a robust method for measuring the cosmological distance scale. The distance that the sound can travel can be computed to high precision and creates a signature in the late-time clustering of matter that serves as a standard ruler. Galaxy clustering results

  1. CAN COUPLED DARK ENERGY SPEED UP THE BULLET CLUSTER?

    SciTech Connect (OSTI)

    Lee, Jounghun; Baldi, Marco E-mail: marco.baldi@universe-cluster.de

    2012-03-01

    It has been recently shown that the observed morphological properties of the Bullet Cluster can be accurately reproduced in hydrodynamical simulations only when the infall pairwise velocity V{sub c} of the system exceeds 3000 km s{sup -1} (or at least possibly 2500 km s{sup -1}) at the pair separation of 2R{sub vir}, where R{sub vir} is the virial radius of the main cluster, and that the probability of finding such a bullet-like system is extremely low in the standard {Lambda} cold dark matter ({Lambda}CDM) cosmology. We suggest here the fifth force mediated by coupled dark energy (cDE) as a possible velocity-enhancing mechanism and investigate its effect on the infall velocities of bullet-like systems from the Coupled Dark Energy Cosmological Simulations public database. Five different cDE models are considered: three with constant coupling and exponential potential, one with exponential coupling and exponential potential, and one with constant coupling and supergravity potential. For each model, after identifying the bullet-like systems, we determine the probability density distribution of their infall velocities at pair separations of (2-3)R{sub vir}. Approximating each probability density distribution as a Gaussian, we calculate the cumulative probability of finding a bullet-like system with V{sub c} {>=} 3000 km s{sup -1} or V{sub c} {>=} 2500 km s{sup -1}. Our results show that in all of the five cDE models the cumulative probabilities increase compared to the {Lambda}CDM case and that in the model with exponential coupling P(V{sub c} {>=} 2500 km s{sup -1}) exceeds 10{sup -4}. The physical interpretations and cosmological implications of our results are provided.

  2. Holographic dark energy with varying gravitational constant in Ho?ava-Lifshitz cosmology

    SciTech Connect (OSTI)

    Setare, M.R.; Jamil, Mubasher E-mail: mjamil@camp.nust.edu.pk

    2010-02-01

    We investigate the holographic dark energy scenario with a varying gravitational constant in a flat background in the context of Ho?ava-Lifshitz gravity. We extract the exact differential equation determining the evolution of the dark energy density parameter, which includes G variation term. Also we discuss a cosmological implication of our work by evaluating the dark energy equation of state for low redshifts containing varying G corrections.

  3. Observational constraints on holographic dark energy with varying gravitational constant

    SciTech Connect (OSTI)

    Lu, Jianbo; Xu, Lixin; Saridakis, Emmanuel N.; Setare, M.R. E-mail: msaridak@phys.uoa.gr E-mail: lxxu@dlut.edu.cn

    2010-03-01

    We use observational data from Type Ia Supernovae (SN), Baryon Acoustic Oscillations (BAO), Cosmic Microwave Background (CMB) and observational Hubble data (OHD), and the Markov Chain Monte Carlo (MCMC) method, to constrain the cosmological scenario of holographic dark energy with varying gravitational constant. We consider both flat and non-flat background geometry, and we present the corresponding constraints and contour-plots of the model parameters. We conclude that the scenario is compatible with observations. In 1? we find ?{sub ?0} = 0.72{sup +0.03}{sub ?0.03}, ?{sub k0} = ?0.0013{sup +0.0130}{sub ?0.0040}, c = 0.80{sup +0.19}{sub ?0.14} and ?{sub G}?G'/G = ?0.0025{sup +0.0080}{sub ?0.0050}, while for the present value of the dark energy equation-of-state parameter we obtain w{sub 0} = ?1.04{sup +0.15}{sub ?0.20}.

  4. Housing characteristics, 1987: Residential Energy Consumption Survey

    SciTech Connect (OSTI)

    Not Available

    1989-05-26

    This report is the first of a series of reports based on data from the 1987 RECS. The 1987 RECS is the seventh in the series of national surveys of households and their energy suppliers. These surveys provide baseline information on how households in the United States use energy. A cross section of housing types such as single-family detached homes, townhouses, large and small apartment buildings, condominiums, and mobile homes were included in the survey. Data from the RECS and a companion survey, the Residential Transportation Energy Consumption Survey (RTECS), are available to the public in published reports such as this one and on public use tapes. 10 figs., 69 tabs.

  5. Department of Energy Earned Value Management Survey Results ...

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

    Department of Energy Earned Value Management Survey Results Department of Energy Earned Value Management Survey Results Humphreys & Associates, Inc. (H&A) conducted a survey of ...

  6. Residential Energy Consumption Survey (RECS) - Analysis & Projections...

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

    efficiency has offset the increase in the number and average size of housing units, according to the newly released data from the Residential Energy Consumption Survey (RECS). ...

  7. Residential Energy Consumption Survey (RECS) - Analysis & Projections...

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

    As a part of the Residential Energy Consumption Survey (RECS), trained interviewers measure the square footage of each housing unit. RECS square footage data allow comparison of ...

  8. Residential Energy Consumption Survey (RECS) - Analysis & Projections...

    Gasoline and Diesel Fuel Update (EIA)

    EIA is releasing new benchmark estimates for home energy use for the year 2009 that include detailed data for 16 States, 12 more than in past EIA residential energy surveys. EIA ...

  9. Cosmic slowing down of acceleration for several dark energy parametrizations

    SciTech Connect (OSTI)

    Magaña, Juan; Cárdenas, Víctor H.; Motta, Verónica E-mail: victor.cardenas@uv.cl

    2014-10-01

    We further investigate slowing down of acceleration of the universe scenario for five parametrizations of the equation of state of dark energy using four sets of Type Ia supernovae data. In a maximal probability analysis we also use the baryon acoustic oscillation and cosmic microwave background observations. We found the low redshift transition of the deceleration parameter appears, independently of the parametrization, using supernovae data alone except for the Union 2.1 sample. This feature disappears once we combine the Type Ia supernovae data with high redshift data. We conclude that the rapid variation of the deceleration parameter is independent of the parametrization. We also found more evidence for a tension among the supernovae samples, as well as for the low and high redshift data.

  10. Mega-masers, Dark Energy and the Hubble Constant

    SciTech Connect (OSTI)

    Lo, Fred K. Y.

    2007-10-15

    Powerful water maser emission (water mega-masers) can be found in accretion disks in the nuclei of some galaxies. Besides providing a measure of the mass at the nucleus, such mega-masers can be used to determine the distance to the host galaxy, based on a kinematic model. We will explain the importance of determining the Hubble Constant to high accuracy for constraining the equation of state of Dark Energy and describe the Mega-maser Cosmology Project that has the goal of determining the Hubble Constant to better than 3%. Time permitting, we will also present the scientific capabilities of the current and future NRAO facilities: ALMA, EVLA, VLBA and GBT, for addressing key astrophysical problems

  11. MODEL-INDEPENDENT EVIDENCE FOR DARK ENERGY EVOLUTION FROM BARYON ACOUSTIC OSCILLATIONS

    SciTech Connect (OSTI)

    Sahni, V.; Shafieloo, A.; Starobinsky, A. A. E-mail: arman@apctp.org

    2014-10-01

    Baryon acoustic oscillations (BAOs) allow us to determine the expansion history of the universe, thereby shedding light on the nature of dark energy. Recent observations of BAOs in the Sloan Digital Sky Survey (SDSS) DR9 and DR11 have provided us with statistically independent measurements of H(z) at redshifts of 0.57 and 2.34, respectively. We show that these measurements can be used to test the cosmological constant hypothesis in a model-independent manner by means of an improved version of the Om diagnostic. Our results indicate that the SDSS DR11 measurement of H(z) = 222 ± 7 km s{sup –1} Mpc{sup –1} at z = 2.34, when taken in tandem with measurements of H(z) at lower redshifts, imply considerable tension with the standard ΛCDM model. Our estimation of the new diagnostic Omh {sup 2} from SDSS DR9 and DR11 data, namely, Omh {sup 2} ≈ 0.122 ± 0.01, which is equivalent to Ω{sub 0m} h {sup 2} for the spatially flat ΛCDM model, is in tension with the value Ω{sub 0m} h {sup 2} = 0.1426 ± 0.0025 determined for ΛCDM from Planck+WP. This tension is alleviated in models in which the cosmological constant was dynamically screened (compensated) in the past. Such evolving dark energy models display a pole in the effective equation of state of dark energy at high redshifts, which emerges as a smoking gun test for these theories.

  12. Dark Energy Rules the Universe (and why the dinosaurs do not!) (LBNL Science at the Theater)

    ScienceCinema (OSTI)

    Linder, Eric

    2011-04-28

    The revolutionary discovery that the expansion of the universe is speeding up, not slowing down from gravity, means that 75 percent of our universe consists of mysterious dark energy. Berkeley Lab theoretical physicist Eric Linder delves into the mystery of dark energy as part of the Science in the Theatre lecture series on Nov. 24, 2008.

  13. Reflection Survey | Open Energy Information

    Open Energy Info (EERE)

    (Gritto, Et Al.) Rye Patch Area Integrated Seismic Studies At The Rye Patch Geothermal Reservoir, Nevada Reflection Survey At Rye Patch Area (Laney, 2005) Rye Patch Area Federal...

  14. Energy Information Agency's 2003 Commercial Building Energy Consumption Survey Tables

    Office of Energy Efficiency and Renewable Energy (EERE)

    Energy use intensities in commercial buildings vary widely and depend on activity and climate, as shown in this data table, which was derived from the Energy Information Agency's 2003 Commercial Building Energy Consumption Survey.

  15. Dark energy: Q&A with Steve Kuhlmann | Argonne National Laboratory

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

    energy: Q&A with Steve Kuhlmann Dark energy: Q&A with Steve Kuhlmann By Jared Sagoff * September 17, 2012 Tweet EmailPrint Why do we care about dark energy in the first place? One of the most fundamental questions that scientists face is to try to figure out what the universe is made of. We know that dark energy is the largest component of the universe, accounting for about 74 percent of the mass and energy that exists combined. If we want to understand the components of the universe, we

  16. Detecting features in the dark energy equation of state: a wavelet approach

    SciTech Connect (OSTI)

    Hojjati, Alireza; Pogosian, Levon; Zhao, Gong-Bo E-mail: levon@sfu.ca

    2010-04-01

    We study the utility of wavelets for detecting the redshift evolution of the dark energy equation of state w(z) from the combination of supernovae (SNe), CMB and BAO data. We show that local features in w, such as bumps, can be detected efficiently using wavelets. To demonstrate, we first generate a mock supernovae data sample for a SNAP-like survey with a bump feature in w(z) hidden in, then successfully discover it by performing a blind wavelet analysis. We also apply our method to analyze the recently released ''Constitution'' SNe data, combined with WMAP and BAO from SDSS, and find weak hints of dark energy dynamics. Namely, we find that models with w(z) < −1 for 0.2 < z < 0.5, and w(z) > −1 for 0.5 < z < 1, are mildly favored at 95% confidence level. This is in good agreement with several recent studies using other methods, such as redshift binning with principal component analysis (PCA) (e.g. Zhao and Zhang, arXiv: 0908.1568)

  17. Three Ways to Bust Ghostly Dark Matter | Department of Energy

    Office of Environmental Management (EM)

    ... about two years ago. | Image courtesy of NASA. Dark Matter and a Definite Non-Definite ... waves for millennia. | Graphic courtesy of NASA When Galaxies Collide: Ripples Indicate ...

  18. Manufacturing Energy Consumption Survey (MECS) - U.S. Energy Information

    Gasoline and Diesel Fuel Update (EIA)

    Administration (EIA) U. S. Census Regions and Divisions: census map About the MECS Survey forms Maps MECS Terminology Archives Features First 2010 Data Press Release 2010 Data Brief Other End Use Surveys Commercial Buildings - CBECS Residential - RECS Transportation DOE Uses MECS Data Manufacturing Energy and Carbon Footprints Associated Analysis Manufacturing Energy Sankey Diagrams Manufacturing Energy Flows Tool

  19. 2005 Residential Energy Consumption Survey

    U.S. Energy Information Administration (EIA) Indexed Site

    Completed forms are due by March 4, 2006. If you have any questions, please call (toll-free) 1-NNN-NNN-NNNN. Ask for the Supplier Survey Specialist. This report is mandatory under ...

  20. 2005 Residential Energy Consumption Survey

    U.S. Energy Information Administration (EIA) Indexed Site

    Completed forms are due by March 4, 2006. If you have any questions, please call (toll-free) 1-NNN-NNN-NNNN. Ask for the Supplier Survey Specialist.. This report is mandatory under ...

  1. Geodetic Survey | Open Energy Information

    Open Energy Info (EERE)

    At Kilauea Summit Area (Keller, Et Al., 1979) Kilauea Summit Area Results Of An Experimental Drill Hole At The Summit Of Kilauea Volcano, Hawaii Geodetic Survey At Long Valley...

  2. Geothermal Energy Growth Continues, Industry Survey Reports

    Broader source: Energy.gov [DOE]

    A survey released by the Geothermal Energy Association (GEA) shows continued growth in the number of new geothermal power projects under development in the United States, a 20% increase since January of this year.

  3. Residential Energy Consumption Survey (RECS) - Analysis & Projections...

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

    According to results from EIA's 2009 Residential Energy Consumption Survey (RECS), the stock of homes built in the 1970s and 1980s averages less than 1,800 square feet (Fig. 1). ...

  4. Residential Energy Consumption Survey (RECS) - Analysis & Projections...

    Gasoline and Diesel Fuel Update (EIA)

    slightly from 10.58 quads in 1978 to 10.55 quads in 2005 as reported by the most recent consumption and expenditures data from the Residential Energy Consumption Survey (RECS). ...

  5. UP TO 100,000 RELIABLE STRONG GRAVITATIONAL LENSES IN FUTURE DARK ENERGY EXPERIMENTS

    SciTech Connect (OSTI)

    Serjeant, S.

    2014-09-20

    The Euclid space telescope will observe ?10{sup 5} strong galaxy-galaxy gravitational lens events in its wide field imaging survey over around half the sky, but identifying the gravitational lenses from their observed morphologies requires solving the difficult problem of reliably separating the lensed sources from contaminant populations, such as tidal tails, as well as presenting challenges for spectroscopic follow-up redshift campaigns. Here I present alternative selection techniques for strong gravitational lenses in both Euclid and the Square Kilometre Array, exploiting the strong magnification bias present in the steep end of the H? luminosity function and the H I mass function. Around 10{sup 3} strong lensing events are detectable with this method in the Euclid wide survey. While only ?1% of the total haul of Euclid lenses, this sample has ?100% reliability, known source redshifts, high signal-to-noise, and a magnification-based selection independent of assumptions of lens morphology. With the proposed Square Kilometre Array dark energy survey, the numbers of reliable strong gravitational lenses with source redshifts can reach 10{sup 5}.

  6. Improved Dark Energy Constraints From ~ 100 New CfA Supernova Type Ia Light

    Office of Scientific and Technical Information (OSTI)

    Curves (Journal Article) | SciTech Connect Improved Dark Energy Constraints From ~ 100 New CfA Supernova Type Ia Light Curves Citation Details In-Document Search Title: Improved Dark Energy Constraints From ~ 100 New CfA Supernova Type Ia Light Curves We combine the CfA3 supernovae Type Ia (SN Ia) sample with samples from the literature to calculate improved constraints on the dark energy equation of state parameter, w. The CfA3 sample is added to the Union set of Kowalski et al. to form the

  7. Steam System Survey Guide | Department of Energy

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

    Survey Guide Steam System Survey Guide This guide provides technical information for steam system operational personnel and plant energy managers on some of the major opportunities available to improve the energy efficiency and productivity of industrial steam systems. The guide covers five main areas of investigation: (1) profiling a steam system, (2) identifying steam properties for the steam system, (3) improving boiler operations, (4) improving resource utilization in the steam system, and

  8. Manufacturing Energy Consumption Survey (MECS) - U.S. Energy Information

    U.S. Energy Information Administration (EIA) Indexed Site

    Administration (EIA) ‹ Consumption & Efficiency Manufacturing Energy Consumption Survey (MECS) Glossary › FAQS › Overview Data 2010 2006 2002 1998 1994 1991 Archive Analysis & Projections Cost of Natural Gas Used in Manufacturing Sector Has Fallen Graph showing Cost of Natural Gas Used in Manufacturing Sector Has Fallen Source: U.S. Energy Information Administration, Manufacturing Energy Consumption Survey (MECS) 1998-2010, September 6, 2013. New 2010 Manufacturing Energy

  9. Commercial Buildings Energy Consumption Survey (CBECS) - How Was Energy

    Gasoline and Diesel Fuel Update (EIA)

    Usage Information Collected in the 2012 CBECS? Energy Usage Information Collected in the 2012 CBECS? CBECS 2012 - Release date: March 18, 2016 The Commercial Buildings Energy Consumption Survey (CBECS) project cycle spans at least four years, beginning with development of the sample frame and survey questionnaire and ending with release of data to the public. This set of three methodology documents provides details about each of the three major stages of the 2012 CBECS survey process. * How

  10. Dark energy camera to probe universe's biggest mysteries | Argonne

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

    Dark Matter and a Definite Non-Definite Dark Matter and a Definite Non-Definite April 17, 2013 - 4:22pm Addthis The Alpha Magnetic Spectrometer experiment is a particle detector which was lofted to the International Space Station onboard the Space Shuttle Endeavour about two years ago. | Image courtesy of NASA. The Alpha Magnetic Spectrometer experiment is a particle detector which was lofted to the International Space Station onboard the Space Shuttle Endeavour about two years ago. | Image

  11. Department of Energy: 2011 Federal Employee Viewpoint Survey...

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

    Department of Energy 2011 Federal Employee Viewpoint Survey: Trend Report Response Summary Surveys Completed 2011 Governmentwide 266,376 2011 Department of Energy 5,613 2010 ...

  12. Observation of two new L4 Neptune Trojans in the Dark Energy...

    Office of Scientific and Technical Information (OSTI)

    using the Dark Energy Camera (DECam) on the 4-meter Blanco telescope at Cerro Tololo Inter- American Observatory. Both are in high-inclination orbits (18.8 and 19.4...

  13. Annealing a Follow-up Program: Improvement of the Dark Energy...

    Office of Scientific and Technical Information (OSTI)

    To this end, we apply a simulated annealing algorithm to maximize the dark energy information at fixed observational cost, and find that optimal follow-up strategies can reduce the ...

  14. Exploring parameter constraints on quintessential dark energy: The inverse power law model

    SciTech Connect (OSTI)

    Yashar, Mark; Bozek, Brandon; Abrahamse, Augusta; Albrecht, Andreas; Barnard, Michael

    2009-05-15

    We report on the results of a Markov chain Monte Carlo analysis of an inverse power law (IPL) quintessence model using the Dark Energy Task Force (DETF) simulated data sets as a representation of future dark energy experiments. We generate simulated data sets for a {lambda}CDM background cosmology as well as a case where the dark energy is provided by a specific IPL fiducial model, and present our results in the form of likelihood contours generated by these two background cosmologies. We find that the relative constraining power of the various DETF data sets on the IPL model parameters is broadly equivalent to the DETF results for the w{sub 0}-w{sub a} parametrization of dark energy. Finally, we gauge the power of DETF 'stage 4' data by demonstrating a specific IPL model which, if realized in the universe, would allow stage 4 data to exclude a cosmological constant at better than the 3{sigma} level.

  15. Photometric Redshifts for the Dark Energy Survey and VISTA and...

    Office of Scientific and Technical Information (OSTI)

    the photometric redshift estimate by a factor of two at z > 1. We draw attention to the ... By removing all galaxies with a 1sigma photo-z scatter greater than 0.1 from our DES+VHS ...

  16. Discovering the Nature of Dark Energy: Towards Better Distances from Type

    Office of Scientific and Technical Information (OSTI)

    Ia Supernovae -- Final Technical Report (Technical Report) | SciTech Connect Discovering the Nature of Dark Energy: Towards Better Distances from Type Ia Supernovae -- Final Technical Report Citation Details In-Document Search Title: Discovering the Nature of Dark Energy: Towards Better Distances from Type Ia Supernovae -- Final Technical Report Type Ia supernovae (SNe Ia; exploding white-dwarf stars) were the key to the Nobel-worthy 1998 discovery and subsequent verification that the

  17. Residential Energy Consumption Survey (RECS) - Energy Information

    U.S. Energy Information Administration (EIA) Indexed Site

    Administration U.S. Energy Information Administration - EIA - Independent Statistics and Analysis Sources & Uses Petroleum & Other Liquids Crude oil, gasoline, heating oil, diesel, propane, and other liquids including biofuels and natural gas liquids. Natural Gas Exploration and reserves, storage, imports and exports, production, prices, sales. Electricity Sales, revenue and prices, power plants, fuel use, stocks, generation, trade, demand & emissions. Consumption &

  18. Experimental High Energy Physics Research: Direct Detection of Dark Matter

    SciTech Connect (OSTI)

    Witherell, Michael S.

    2014-10-02

    The grant supported research on an experimental search for evidence of dark matter interactions with normal matter. The PI carried out the research as a member of the LUX and LZ collaborations. The LUX research team collected a first data set with the LUX experiment, a large liquid xenon detector installed in the Sanford Underground Research Facility (SURF). The first results were published in Physical Review Letters on March 4, 2014. The journal Nature named the LUX result a scientific highlight of the year for 2013. In addition, the LZ collaboration submitted the full proposal for the Lux Zeplin experiment, which has since been approved by DOE-HEP as a second-generation dark matter experiment. Witherell is the Level 2 manager for the Outer Detector System on the LUX-Zeplin experiment.

  19. Manufacturing Energy Consumption Survey (MECS) - Data - U.S. Energy

    U.S. Energy Information Administration (EIA) Indexed Site

    Information Administration (EIA) 8 MECS Survey Data 2010 | 2006 | 2002 | 1998 | 1994 | 1991 | Archive Data Methodology & Forms + EXPAND ALL Consumption of Energy for All Purposes (First Use) Values SIC RSE Number of Establishments by First Use of Energy for All Purposes (Fuel and Nonfuel), 1998; Level: National Data; Row: NAICS Codes; Column: Energy Sources and Shipments; Unit: Establishment Counts XLS XLS XLS First Use of Energy for All Purposes (Fuel and Nonfuel), 1998; Level: National

  20. Manufacturing-Industrial Energy Consumption Survey(MECS) Historical...

    U.S. Energy Information Administration (EIA) Indexed Site

    reports, data tables and questionnaires Released: May 2008 The Manufacturing Energy Consumption Survey (MECS) is a periodic national sample survey devoted to measuring...

  1. NASA and DOE Collaborate on Dark Energy Research | U.S. DOE Office of

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

    Science (SC) 8 » NASA and DOE Collaborate on Dark Energy Research News News Home Featured Articles 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 Science Headlines Science Highlights Presentations & Testimony News Archives Communications and Public Affairs Contact Information Office of Science U.S. Department of Energy 1000 Independence Ave., SW Washington, DC 20585 P: (202) 586-5430 11.19.08 NASA and DOE Collaborate on Dark Energy Research Print Text Size: A A A Subscribe

  2. NEPA Litigation Surveys | Department of Energy

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

    NEPA Litigation Surveys NEPA Litigation Surveys CEQ publishes surveys on NEPA litigation on an annual basis. These surveys identify the number of cases involving a NEPA based cause...

  3. Commercial Buildings Energy Consumption Survey - Office Buildings

    Reports and Publications (EIA)

    2010-01-01

    Provides an in-depth look at this building type as reported in the 2003 Commercial Buildings Energy Consumption Survey. Office buildings are the most common type of commercial building and they consumed more than 17% of all energy in the commercial buildings sector in 2003. This special report provides characteristics and energy consumption data by type of office building (e.g. administrative office, government office, medical office) and information on some of the types of equipment found in office buildings: heating and cooling equipment, computers, servers, printers, and photocopiers.

  4. High-energy neutrino signals from the Sun in dark matter scenarios with internal bremsstrahlung

    SciTech Connect (OSTI)

    Ibarra, Alejandro; Totzauer, Maximilian; Wild, Sebastian E-mail: maximilian.totzauer@mytum.de

    2013-12-01

    We investigate the prospects to observe a high energy neutrino signal from dark matter annihilations in the Sun in scenarios where the dark matter is a Majorana fermion that couples to a quark and a colored scalar via a Yukawa coupling. In this minimal scenario, the dark matter capture and annihilation in the Sun can be studied in a single framework. We find that, for small and moderate mass splitting between the dark matter and the colored scalar, the two-to-three annihilation q q-bar g plays a central role in the calculation of the number of captured dark matter particles. On the other hand, the two-to-three annihilation into q q-bar Z gives, despite its small branching fraction, the largest contribution to the neutrino flux at the Earth at the highest energies. We calculate the limits on the model parameters using IceCube observations of the Sun and we discuss their interplay with the requirement of equilibrium of captures and annihilations in the Sun and with the requirement of thermal dark matter production. We also compare the limits from IceCube to the limits from direct detection, antiproton measurements and collider searches.

  5. High Energy Electron Signals from Dark Matter Annihilation in the Sun

    SciTech Connect (OSTI)

    Schuster, Philip; Toro, Natalia; Weiner, Neal; Yavin, Itay; /New York U., CCPP

    2012-04-09

    In this paper we discuss two mechanisms by which high energy electrons resulting from dark matter annihilations in or near the Sun can arrive at the Earth. Specifically, electrons can escape the sun if DM annihilates into long-lived states, or if dark matter scatters inelastically, which would leave a halo of dark matter outside of the sun. Such a localized source of electrons may affect the spectra observed by experiments with narrower fields of view oriented towards the sun, such as ATIC, differently from those with larger fields of view such as Fermi. We suggest a simple test of these possibilities with existing Fermi data that is more sensitive than limits from final state radiation. If observed, such a signal will constitute an unequivocal signature of dark matter.

  6. Quantifying the impact of future Sandage-Loeb test data on dark energy constraints

    SciTech Connect (OSTI)

    Geng, Jia-Jia; Zhang, Jing-Fei; Zhang, Xin E-mail: jfzhang@mail.neu.edu.cn

    2014-07-01

    The Sandage-Loeb (SL) test is a unique method to probe dark energy in the ''redshift desert'' of 2∼dark energy probes. Therefore, it is of great importance to quantify how the future SL test data impact on the dark energy constraints. To avoid the potential inconsistency in data, we use the best-fitting model based on the other geometric measurements as the fiducial model to produce 30 mock SL test data. The 10-yr, 20-yr, and 30-yr observations of SL test are analyzed and compared in detail. We show that compared to the current combined data of type Ia supernovae, baryon acoustic oscillation, cosmic microwave background, and Hubble constant, the 30-yr observation of SL test could improve the constraint on Ω{sub m} by about 80% and the constraint on w by about 25%. Furthermore, the SL test can also improve the measurement of the possible direct interaction between dark energy and dark matter. We show that the SL test 30-yr data could improve the constraint on γ by about 30% and 10% for the Q = γHρ{sub c} and Q = γHρ{sub de} models, respectively.

  7. Spontaneous symmetry breaking in cosmos: the hybrid symmetron as a dark energy switching device

    SciTech Connect (OSTI)

    Bamba, K.; Nojiri, S.; Gannouji, R.; Kamijo, M.; Sami, M. E-mail: gannouji@rs.kagu.tus.ac.jp E-mail: nojiri@phys.nagoya-u.ac.jp

    2013-07-01

    We consider symmetron model in a generalized background with a hope to make it compatible with dark energy. We observe a ''no go'' theorem at least in case of a conformal coupling. Being convinced of symmetron incapability to be dark energy, we try to retain its role for spontaneous symmetry breaking and assign the role of dark energy either to standard quintessence or F(R) theory which are switched on by symmetron field in the symmetry broken phase. The scenario reduces to standard Einstein gravity in the high density region. After the phase transition generated by symmetron field, either the F(R) gravity or the standard quintessence are induced in the low density region. we demonstrate that local gravity constraints and other requirements are satisfied although the model could generate the late-time acceleration of Universe.

  8. Manufacturing Energy Consumption Survey (MECS) - Data - U.S. Energy

    U.S. Energy Information Administration (EIA) Indexed Site

    Information Administration (EIA) 1 MECS Survey Data 2010 | 2006 | 2002 | 1998 | 1994 | 1991 | Archive Data Methodology & Forms + EXPAND ALL Consumption of Energy for All Purposes (First Use) Total Primary Consumption of Energy for All Purposes by Census Region, Industry Group, and Selected Industries, 1991: Part 1 (Estimates in Btu or Physical Units) XLS Total Primary Consumption of Energy for All Purposes by Census Region, Industry Group, and Selected Industries, 1991: Part 2 (Estimates

  9. Manufacturing Energy Consumption Survey (MECS) - Data - U.S. Energy

    U.S. Energy Information Administration (EIA) Indexed Site

    Information Administration (EIA) 4 MECS Survey Data 2010 | 2006 | 2002 | 1998 | 1994 | 1991 | Archive Data Methodology & Forms + EXPAND ALL Consumption of Energy for All Purposes (First Use) Total First Use (formerly Primary Consumption) of Energy for All Purposes by Census Region, Census Division, Industry Group, and Selected Industries, 1994: Part 1 (Estimates in Btu or Physical Units) XLS Total First Use (formerly Primary Consumption) of Energy for All Purposes by Census Region,

  10. Discovery of Dark Energy Ushered in a New Era in Computational Cosmology

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

    Discovery of Dark Energy Ushered in a New Era in Computational Cosmology Discovery of Dark Energy Ushered in a New Era in Computational Cosmology October 4, 2011 John Hules, JAHules@lbl.gov, +1 510 486 6008 "If NERSC does not enable a major scientific discovery every few years, then we're not doing our job." That was the challenge issued by Bill McCurdy, then Lawrence Berkeley National Laboratory's Associate Laboratory Director for Computing Sciences, at the first all-hands meeting for

  11. Dark Matter Theory

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

    Dark Matter Theory Dark Matter Theory Understanding discoveries at the Energy, Intensity, and Cosmic Frontiers Get Expertise Rajan Gupta (505) 667-7664 Email Bruce Carlsten (505) ...

  12. Observational constraints on dark energy with a fast varying equation of state

    SciTech Connect (OSTI)

    Felice, Antonio De; Nesseris, Savvas

    2012-05-01

    We place observational constraints on models with the late-time cosmic acceleration based on a number of parametrizations allowing fast transitions for the equation of state of dark energy. In addition to the model of Linder and Huterer where the dark energy equation of state w monotonically grows or decreases in time, we propose two new parametrizations in which w has an extremum. We carry out the likelihood analysis with the three parametrizations by using the observational data of supernovae type Ia, cosmic microwave background, and baryon acoustic oscillations. Although the transient cosmic acceleration models with fast transitions can give rise to the total chi square smaller than that in the ?-Cold-Dark-Matter (?CDM) model, these models are not favored over ?CDM when one uses the Akaike information criterion which penalizes the extra degrees of freedom present in the parametrizations.

  13. Design Code Survey Form | Department of Energy

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

    Design Code Survey Form Design Code Survey Form Survey of Safety Software Used in Design of Structures, Systems, and Components 1. Introduction The Department's Implementation Plan ...

  14. Homeowner and Contractor Surveys | Department of Energy

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

    Homeowner and Contractor Surveys Homeowner and Contractor Surveys Better Buildings Neighborhood Program Data and Evaluation Peer Exchange Call: Homeowner and Contractor Surveys, ...

  15. Commercial Buildings Energy Consumption Survey (CBECS) - U.S...

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

    Consumption & Efficiency Commercial Buildings Energy Consumption Survey (CBECS) Glossary FAQS Overview Data 2012 2003 1999 1995 1992 Previous Analysis & Projections ...

  16. Energy Efficiency and Renewable Energy Network (EREN): Customer satisfaction survey

    SciTech Connect (OSTI)

    Anderson, A.V.; Henderson, D.P.

    1996-04-22

    The Energy Efficiency and Renewable Energy Network (EREN) Customer Satisfaction Survey was developed and executed in support of EREN`s continuous quality improvement (CQI) plan. The study was designed to provide information about the demographic make up of EREN users, the value or benefits they derive from EREN, the kinds and quality of services they want, their levels of satisfaction with existing services, their preferences in both the sources of service and the means of delivery, and to provide benchmark data for the establishment of continuous quality improvement measures. The survey was performed by soliciting voluntary participation from members of the EREN Users Group. It was executed in two phases; the first being conducted by phone using a randomly selected group; and the second being conducted electronically and which was open to all of the remaining members of the Users Group. The survey results are described.

  17. Commercial Buildings Energy Consumption Survey (CBECS) - U.S. Energy

    Gasoline and Diesel Fuel Update (EIA)

    Information Administration (EIA) Relationship of CBECS Coverage to EIA Supply Surveys The primary purpose of the CBECS is to collect accurate statistics of energy consumption by individual buildings. EIA also collects data on total energy supply (sales). For the information on sales totals, a different reporting system is used for each fuel and the boundaries between the different sectors (e.g., residential, commercial, industrial) are drawn differently for each fuel. Background EIA sales

  18. Cosmological Simulations for Large-Scale Sky Surveys | Argonne...

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

    The focus of cosmology today is on its two mysterious pillars, dark matter and dark energy. Large-scale sky surveys are the current drivers of precision cosmology and have been ...

  19. Cosmological Simulations for Large-Scale Sky Surveys | Argonne...

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

    The focus of cosmology today revolves around two mysterious pillars, dark matter and dark energy. Large-scale sky surveys are the current drivers of precision cosmology and have ...

  20. Seeking Answers in the Darkness | Department of Energy

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

    John Schueler John Schueler Former New Media Specialist, Office of Public Affairs What are the key facts? Fermilab is leading construction of a 570-megapixel camera, which attached to the Bianco 4-meter telescope, will survey the deepest reaches of the universe to answer questions on the behavior of gravity. In 1998, two teams of astronomers studying distant supernovae made the remarkable discovery that the expansion of the universe is speeding up. This flies in the face of Einstein's theory of

  1. 2009 - Federal Viewpoint Survey Reports | Department of Energy

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

    09 - Federal Viewpoint Survey Reports 2009 - Federal Viewpoint Survey Reports The 2009 Trend report provides summary results for the Department or Energy's portion of the Federal Employee Viewpoint Survey. The report also shows how the 2009 results compare to the results of previous years. 2009 Annual Employee Survey Results (78.54 KB) 2009 Annual Employee Survey Comparison Report (135.13 KB) 2009 Annual Employee Survey Trend Report (62.54 KB) Responsible Contacts Thomasina Mathews PROGRAM

  2. A dark energy camera search for an optical counterpart to the first advanced LIGO gravitational wave event GW150914

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Soares-Santos, M.

    2016-05-27

    We report the results of a deep search for an optical counterpart to the gravitational wave (GW) event GW150914, the first trigger from the Advanced LIGO GW detectors. We used the Dark Energy Camera (DECam) to image a 102 deg2 area, corresponding to 38% of the initial trigger high-probability sky region and to 11% of the revised high-probability region. We observed in the i and z bands at 4–5, 7, and 24 days after the trigger. The median 5σ point-source limiting magnitudes of our search images are i = 22.5 and z = 21.8 mag. We processed the images throughmore » a difference-imaging pipeline using templates from pre-existing Dark Energy Survey data and publicly available DECam data. Due to missing template observations and other losses, our effective search area subtends 40 deg2, corresponding to a 12% total probability in the initial map and 3% in the final map. In this area, we search for objects that decline significantly between days 4–5 and day 7, and are undetectable by day 24, finding none to typical magnitude limits of i = 21.5, 21.1, 20.1 for object colors (i – z) = 1, 0, –1, respectively. Lastly, our search demonstrates the feasibility of a dedicated search program with DECam and bodes well for future research in this emerging field.« less

  3. Biofuels Quality Surveys | Department of Energy

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

    Biofuels Quality Surveys Biofuels Quality Surveys 2012 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting ...

  4. Category:Telluric Survey | Open Energy Information

    Open Energy Info (EERE)

    Pages in category "Telluric Survey" This category contains only the following page. T Telluric Survey Retrieved from "http:en.openei.orgwindex.php?titleCategory:Telluric...

  5. Idaho Geological Survey | Open Energy Information

    Open Energy Info (EERE)

    The Idaho Geological Survey is located in Boise, Idaho. About Information on past oil and gas exploration wells in Idaho was transferred to the Idaho Geological Survey in...

  6. Commercial Buildings Energy Consumption Survey (CBECS) - U.S. Energy

    Gasoline and Diesel Fuel Update (EIA)

    Information Administration (EIA) Building Type Definitions In the Commercial Buildings Energy Consumption Survey (CBECS), buildings are classified according to principal activity, which is the primary business, commerce, or function carried on within each building. Buildings used for more than one of the activities described below are assigned to the activity occupying the most floorspace. A building assigned to a particular principal activity category may be used for other activities in a

  7. Manufacturing Energy Consumption Survey (MECS) - Data - U.S. Energy

    U.S. Energy Information Administration (EIA) Indexed Site

    Information Administration (EIA) 2 MECS Survey Data 2010 | 2006 | 2002 | 1998 | 1994 | 1991 | Archive Data Methodology & Forms all tables + EXPAND ALL Consumption of Energy for All Purposes (First Use) Values RSE Table 1.1 By Mfg. Industry & Region (physical units) XLS PDF XLS Table 1.2 By Mfg. Industry & Region (trillion Btu) XLS PDF XLS Table 1.3 By Value of Shipments & Employment Size Category & Region XLS PDF Table 1.4 Number of Establishments Using Energy Consumed

  8. Manufacturing Energy Consumption Survey (MECS) - Data - U.S. Energy

    U.S. Energy Information Administration (EIA) Indexed Site

    Information Administration (EIA) 10 MECS Survey Data 2010 | 2006 | 2002 | 1998 | 1994 | 1991 | Archive Data Methodology & Forms + EXPAND ALL Consumption of Energy for All Purposes (First Use) Table 1.1 By Mfg. Industry & Region (physical units) XLS PDF Table 1.2 By Mfg. Industry & Region (trillion Btu) XLS PDF Table 1.3 By Value of Shipments & Employment Size Category & Region XLS PDF Table 1.4 Number of Establishments Using Energy Consumed for All Purpose XLS PDF Table

  9. Precision Spectrophotometric Calibration System for Dark Energy Instruments

    SciTech Connect (OSTI)

    Schubnell, Michael S.

    2015-06-30

    For this research we build a precision calibration system and carried out measurements to demonstrate the precision that can be achieved with a high precision spectrometric calibration system. It was shown that the system is capable of providing a complete spectrophotometric calibration at the sub-pixel level. The calibration system uses a fast, high precision monochromator that can quickly and efficiently scan over an instrument’s entire spectral range with a spectral line width of less than 0.01 nm corresponding to a fraction of a pixel on the CCD. The system was extensively evaluated in the laboratory. Our research showed that a complete spectrophotometric calibration standard for spectroscopic survey instruments such as DESI is possible. The monochromator precision and repeatability to a small fraction of the DESI spectrograph LSF was demonstrated with re-initialization on every scan and thermal drift compensation by locking to multiple external line sources. A projector system that mimics telescope aperture for point source at infinity was demonstrated.

  10. Cool Trends in District Energy: A Survey of Thermal Energy Storage Use in

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

    District Energy Utility Applications, June 2005 | Department of Energy in District Energy: A Survey of Thermal Energy Storage Use in District Energy Utility Applications, June 2005 Cool Trends in District Energy: A Survey of Thermal Energy Storage Use in District Energy Utility Applications, June 2005 This 2005 survey considers the use of cool Thermal Energy Storage (TES) in District Cooling utility applications. cool_trends_in_de.pdf (86.08 KB) More Documents & Publications Cool Trends

  11. Process Heating Assessment and Survey Tool | Department of Energy

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

    Process Heating Assessment and Survey Tool Process Heating Assessment and Survey Tool April 10, 2014 - 3:34pm Addthis Process Heating Assessment and Survey Tool The Process Heating Assessment and Survey Tool (PHAST) introduces methods to improve thermal efficiency of heating equipment. This tool helps industrial users survey process heating equipment that consumes fuel, steam, or electricity, and identifies the most energy-intensive equipment. The tool can be used to perform a heat balance that

  12. 2014-Federal Viewpoint Survey Reports | Department of Energy

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

    4-Federal Viewpoint Survey Reports 2014-Federal Viewpoint Survey Reports The following highlight report focuses on the Department of Energy's areas of strengths and challenges, identifies areas of progress and opportunities for improvement. The Departments 2014 results are compared with the 2013 Government wide results. 2014 Federal Employee Viewpoint Survey Results: Annual Employee Survey (AES) Report (71.11 KB) 2014 Federal Employee Viewpoint Survey Results: Agency Management Report (AMR)

  13. 2010 - Federal Viewpoint Survey Reports | Department of Energy

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

    0 - Federal Viewpoint Survey Reports 2010 - Federal Viewpoint Survey Reports The 2010 Trend report provides summary results for the Department or Energy's portion of the Federal Employee Viewpoint Survey. The report also shows how the 2010 results compare to the results of previous years. Department of Energy: 2010 Federal Employee Viewpoint Survey Trend Report (253.09 KB) Responsible Contacts Thomasina Mathews PROGRAM MANAGER E-mail thomasina.mathews@hq.doe.gov Phone 202-586-2657 More Documents

  14. 2011 - Federal Viewpoint Survey Reports | Department of Energy

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

    1 - Federal Viewpoint Survey Reports 2011 - Federal Viewpoint Survey Reports The following highlight report focuses on the Department of Energy's areas of strengths and challenges, identifies areas of progress and opportunities for improvement. The Departments 2011 results are compared with both the 2011 Governmentwide results and our 2010 survey results. The Trend report provides summary results for the Department or Energy's portion of the Federal Employee Viewpoint Survey. The report also

  15. Residential Energy Consumption Survey (RECS) - Analysis & Projections -

    Gasoline and Diesel Fuel Update (EIA)

    U.S. Energy Information Administration (EIA) What's new in our home energy use? RECS 2009 - Release date: March 28, 2011 First results from EIA's 2009 Residential Energy Consumption Survey (RECS) The 2009 RECS collected home energy characteristics data from over 12,000 U.S. households. This report highlights findings from the survey, with details presented in the Household Energy Characteristics tables. How we use energy in our homes has changed substantially over the past three decades.

  16. REMS Webinar Survey | Department of Energy

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

    REMS Webinar Survey REMS Webinar Survey Survey for the inaugural DOE REMS Webinar that was held on Tuesday, March 8, 2016 at 1:00 pm EST. REMS Webinar Survey (606.08 KB) More Documents & Publications Radiation Exposure Monitoring Systems Data Submittal Notification EERE's Usability and Analysis Techniques Guidebook

  17. AASG State Geological Survey | Department of Energy

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

    AASG State Geological Survey AASG State Geological Survey presentation at the April 2013 peer review meeting held in Denver, Colorado.Contributions to the NGDSAASG State Geological Survey aasg__geo_survey_peer2013.pdf (2.44 MB) More Documents & Publications State Geological Survey Contributions to the National Geothermal Data System National Geothermal Data System Architecture Design, Testing and Maintenance National Geothermal Data Systems Data Acquisition and Access

  18. Federal Employee Viewpoint Survey | Department of Energy

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

    Policy and Guidance » Human Capital Management » Federal Employee Viewpoint Survey Federal Employee Viewpoint Survey The Federal Employee Viewpoint Survey (FedView survey) is a tool that measures employees' perceptions of whether, and to what extent, conditions characterizing successful organizations are present in their agencies. Survey results provide valuable insight into the challenges agency leaders face in ensuring the Federal Government has an effective civilian workforce and how well

  19. Energy from the Center of the Milky Way May Be the Remnant of Dark Matter |

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

    U.S. DOE Office of Science (SC) Energy from the Center of the Milky Way May Be the Remnant of Dark Matter News News Home Featured Articles 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 Science Headlines Science Highlights Presentations & Testimony News Archives Communications and Public Affairs Contact Information Office of Science U.S. Department of Energy 1000 Independence Ave., SW Washington, DC 20585 P: (202) 586-5430 11.17.10 Energy from the Center of the Milky Way May

  20. Exact solutions in a scalar-tensor model of dark energy

    SciTech Connect (OSTI)

    Granda, L.N.; Loaiza, E. E-mail: edwin.loaiza@correounivalle.edu.co

    2012-09-01

    We consider a model of scalar field with non minimal kinetic and Gauss Bonnet couplings as a source of dark energy. Based on asymptotic limits of the generalized Friedmann equation, we impose restrictions on the kinetic an Gauss-Bonnet couplings. This restrictions considerable simplify the equations, allowing for exact solutions unifying early time matter dominance with transitions to late time quintessence and phantom phases. The stability of the solutions in absence of matter has been studied.

  1. Mass map shines light on dark matter | Argonne National Laboratory

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

    Mass map shines light on dark matter By Sarah Schlieder * July 9, 2015 Tweet EmailPrint Dark matter may find it tougher to hide in our universe. An international team of researchers has developed a new map of the distribution of dark matter in the universe using data from the Dark Energy Survey (DES). The DES, underway at the Blanco telescope in Chile, is a cosmological galaxy survey that will map approximately an eighth of the visible sky. The primary aim of the DES is to better characterize

  2. Testing oscillating primordial spectrum and oscillating dark energy with astronomical observations

    SciTech Connect (OSTI)

    Liu, Jie; Li, Hong; Zhang, Xinmin; Xia, Jun-Qing E-mail: hongli@ihep.ac.cn E-mail: xmzhang@ihep.ac.cn

    2009-07-01

    In this paper we revisit the issue of determining the oscillating primordial scalar power spectrum and oscillating equation of state of dark energy from the astronomical observations. By performing a global analysis with the Markov Chain Monte Carlo method, we find that the current observations from five-year WMAP and SDSS-LRG matter power spectrum, as well as the ''union'' supernovae sample, constrain the oscillating index of primordial spectrum and oscillating equation of state of dark energy with the amplitude less than |n{sub amp}| < 0.116 and |w{sub amp}| < 0.232 at 95% confidence level, respectively. This result shows that the oscillatory structures on the primordial scalar spectrum and the equation of state of dark energy are still allowed by the current data. Furthermore, we point out that these kinds of modulation effects will be detectable (or gotten a stronger constraint) in the near future astronomical observations, such as the PLANCK satellite, LAMOST telescope and the currently ongoing supernovae projects SNLS.

  3. Dynamics of entropy perturbations in assisted dark energy with mixed kinetic terms

    SciTech Connect (OSTI)

    Karwan, Khamphee

    2011-02-01

    We study dynamics of entropy perturbations in the two-field assisted dark energy model. Based on the scenario of assisted dark energy, in which one scalar field is subdominant compared with the other in the early epoch, we show that the entropy perturbations in this two-field system tend to be constant on large scales in the early epoch and hence survive until the present era for a generic evolution of both fields during the radiation and matter eras. This behaviour of the entropy perturbations is preserved even when the fields are coupled via kinetic interaction. Since, for assisted dark energy, the subdominant field in the early epoch becomes dominant at late time, the entropy perturbations can significantly influence the dynamics of density perturbations in the universe. Assuming correlations between the entropy and curvature perturbations, the entropy perturbations can enhance the integrated Sachs-Wolfe (ISW) effect if the signs of the contributions from entropy perturbations and curvature perturbations are opposite after the matter era, otherwise the ISW contribution is suppressed. For canonical scalar field the effect of entropy perturbations on ISW effect is small because the initial value of the entropy perturbations estimated during inflation cannot be sufficiently large. However, in the case of k-essence, the initial value of the entropy perturbations can be large enough to affect the ISW effect to leave a significant imprint on the CMB power spectrum.

  4. The dark energy cosmic clock: a new way to parametrise the equation of state

    SciTech Connect (OSTI)

    Tarrant, Ewan R.M.; Copeland, Edmund J.; Padilla, Antonio; Skordis, Constantinos E-mail: ed.copeland@nottingham.ac.uk E-mail: skordis@nottingham.ac.uk

    2013-12-01

    We propose a new parametrisation of the dark energy equation of state, which uses the dark energy density, Ω{sub e} as a cosmic clock. We expand the equation of state in a series of orthogonal polynomials, with Ω{sub e} as the expansion parameter and determine the expansion coefficients by fitting to SNIa and H(z) data. Assuming that Ω{sub e} is a monotonic function of time, we show that our parametrisation performs better than the popular Chevallier-Polarski-Linder (CPL) and Gerke and Efstathiou (GE) parametrisations, and we demonstrate that it is robust to the choice of prior. Expanding in orthogonal polynomials allows us to relate models of dark energy directly to our parametrisation, which we illustrate by placing constraints on the expansion coefficients extracted from two popular quintessence models. Finally, we comment on how this parametrisation could be modified to accommodate high redshift data, where any non-monotonicity of Ω{sub e} would need to be accounted for.

  5. DOE/EIA-0321/HRIf Residential Energy Consumption Survey. Consumption

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

    purchase diaries from a subset of respondents composing a Household Transportation Panel and is reported separately. Residential Energy Consumption Survey: Consumption and...

  6. Manufacturing Energy Consumption Survey (MECS) - Data - U.S....

    U.S. Energy Information Administration (EIA) Indexed Site

    Archive MECS Survey Data 2010 | 2006 | 2002 | 1998 | 1994 | 1991 | Archive Special Reports (click on table headings to sort) Title Release Year Cycle Year Format Energy-Related...

  7. Utah Geological Survey | Open Energy Information

    Open Energy Info (EERE)

    Logo: Utah Geological Survey Name: Utah Geological Survey Address: 1594 W. North Temple Place: Salt Lake City, Utah Zip: 84114-6100 Phone Number: 801.537.3300 Website:...

  8. Residential Energy Consumption Survey (RECS) - U.S. Energy Information

    Gasoline and Diesel Fuel Update (EIA)

    Administration (EIA) ‹ Consumption & Efficiency Residential Energy Consumption Survey (RECS) Glossary › FAQS › Overview Data 2009 2005 2001 1997 1993 Previous Analysis & Projections RECS Terminology A B C D E F G H I J K L M N O P Q R S T U V W XYZ A Account Classification: The method in which suppliers of electricity, natural gas, or fuel oil classify and bill their customers. Commonly used account classifications are "Commercial," "Industrial,"

  9. Commercial Buildings Energy Consumption Survey (CBECS) - U.S. Energy

    Gasoline and Diesel Fuel Update (EIA)

    Information Administration (EIA) CBECS Terminology NOTE: This glossary is specific to the 1999, 2003 and 2012Commercial Buildings Energy Consumption Surveys (CBECS). CBECS glossaries for prior years can be found in the appendices of past CBECS reports. A B C D E F G H I J K L M N O P Q R S T U V W X Y Z Account Classification: The method in which suppliers of electricity, natural gas, or fuel oil classify and bill their customers. Commonly used account classifications are

  10. Pacific Northwest residential energy survey. Volume 2. Technical appendix

    SciTech Connect (OSTI)

    1980-07-01

    The technical appendix presents the technical aspects of the Pacific Northwest Residential Energy Survey: the survey questionnaire, exhibit cards, instructions for interviewers, and a description of the survey plan. A description of the sample plan (method used to determine which 4000 households) is given. (MCW)

  11. Neutrinos and dark energy after Planck and BICEP2: data consistency tests and cosmological parameter constraints

    SciTech Connect (OSTI)

    Zhang, Jing-Fei; Geng, Jia-Jia; Zhang, Xin E-mail: gengjiajia163@163.com

    2014-10-01

    The detection of the B-mode polarization of the cosmic microwave background (CMB) by the BICEP2 experiment implies that the tensor-to-scalar ratio r should be involved in the base standard cosmology. In this paper, we extend the ΛCDM r+neutrino/dark radiation models by replacing the cosmological constant with the dynamical dark energy with constant w. Four neutrino plus dark energy models are considered, i.e., the wCDM r ∑ m{sub ν}, wCDM r N{sub eff}, wCDM r ∑ m{sub ν} N{sub eff}, and wCDM r N{sub eff} m{sub ν,sterile}{sup eff} models. The current observational data considered in this paper include the Planck temperature data, the WMAP 9-year polarization data, the baryon acoustic oscillation data, the Hubble constant direct measurement data, the Planck Sunyaev-Zeldovich cluster counts data, the Planck CMB lensing data, the cosmic shear data, and the BICEP2 polarization data. We test the data consistency in the four cosmological models, and then combine the consistent data sets to perform joint constraints on the models. We focus on the constraints on the parameters w, ∑ m{sub ν}, N{sub eff}, and m{sub ν,sterile}{sup eff}.

  12. 2012 - Federal Viewpoint Survey Reports | Department of Energy

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

    2 - Federal Viewpoint Survey Reports 2012 - Federal Viewpoint Survey Reports The following highlight report focuses on the Department of Energy's areas of strengths and challenges, identifies areas of progress and opportunities for improvement. The Departments 2012 results are compared with both the 2012 Government wide results and our 2011 survey results. 2012 Federal Employee Viewpoint Survey Results: Agency Management Report (10.75 MB) Responsible Contacts Thomasina Mathews PROGRAM MANAGER

  13. Combined cosmological tests of a bivalent tachyonic dark energy scalar field model

    SciTech Connect (OSTI)

    Keresztes, Zoltán; Gergely, László Á. E-mail: gergely@physx.u-szeged.hu

    2014-11-01

    A recently investigated tachyonic scalar field dark energy dominated universe exhibits a bivalent future: depending on initial parameters can run either into a de Sitter exponential expansion or into a traversable future soft singularity followed by a contraction phase. We also include in the model (i) a tiny amount of radiation, (ii) baryonic matter (Ω{sub b}h{sup 2} = 0.022161, where the Hubble constant is fixed as h = 0.706) and (iii) cold dark matter (CDM). Out of a variety of six types of evolutions arising in a more subtle classification, we identify two in which in the past the scalar field effectively degenerates into a dust (its pressure drops to an insignificantly low negative value). These are the evolutions of type IIb converging to de Sitter and type III hitting the future soft singularity. We confront these background evolutions with various cosmological tests, including the supernova type Ia Union 2.1 data, baryon acoustic oscillation distance ratios, Hubble parameter-redshift relation and the cosmic microwave background (CMB) acoustic scale. We determine a subset of the evolutions of both types which at 1σ confidence level are consistent with all of these cosmological tests. At perturbative level we derive the CMB temperature power spectrum to find the best agreement with the Planck data for Ω{sub CDM} = 0.22. The fit is as good as for the ΛCDM model at high multipoles, but the power remains slightly overestimated at low multipoles, for both types of evolutions. The rest of the CDM is effectively generated by the tachyonic field, which in this sense acts as a combined dark energy and dark matter model.

  14. Supernovae, Dark Energy and the Accelerating Universe: How DOE Helped to Win (yet another) Nobel Prize

    SciTech Connect (OSTI)

    Perlmutter, Saul

    2012-01-13

    The Department of Energy (DOE) hosted an event Friday, January 13, with 2011 Physics Nobel Laureate Saul Perlmutter. Dr. Perlmutter, a physicist at the Departments Lawrence Berkeley National Laboratory and a professor of physics at the University of California at Berkeley, won the 2011 Nobel Prize in Physics for the discovery of the accelerating expansion of the Universe through observations of distant supernovae. DOEs Office of Science has supported Dr. Perlmutters research at Berkeley Lab since 1983. After the introduction from Secretary of Energy Steven Chu, Dr. Perlmutter delivered a presentation entitled "Supernovae, Dark Energy and the Accelerating Universe: How DOE Helped to Win (yet another) Nobel Prize." [Copied with editing from DOE Media Advisory issued January 10th, found at http://energy.gov/articles/energy-department-host-event-2011-physics-nobel-laureate-saul-perlmutter

  15. Supernovae, Dark Energy and the Accelerating Universe: How DOE Helped to Win (yet another) Nobel Prize

    ScienceCinema (OSTI)

    Perlmutter, Saul

    2012-01-13

    The Department of Energy (DOE) hosted an event Friday, January 13, with 2011 Physics Nobel Laureate Saul Perlmutter. Dr. Perlmutter, a physicist at the Department?s Lawrence Berkeley National Laboratory and a professor of physics at the University of California at Berkeley, won the 2011 Nobel Prize in Physics ?for the discovery of the accelerating expansion of the Universe through observations of distant supernovae.? DOE?s Office of Science has supported Dr. Perlmutter?s research at Berkeley Lab since 1983. After the introduction from Secretary of Energy Steven Chu, Dr. Perlmutter delivered a presentation entitled "Supernovae, Dark Energy and the Accelerating Universe: How DOE Helped to Win (yet another) Nobel Prize." [Copied with editing from DOE Media Advisory issued January 10th, found at http://energy.gov/articles/energy-department-host-event-2011-physics-nobel-laureate-saul-perlmutter

  16. Manufacturing Energy Consumption Survey (MECS) - Analysis & Projections -

    U.S. Energy Information Administration (EIA) Indexed Site

    U.S. Energy Information Administration (EIA) About the MECS Survey forms Maps MECS Terminology Archives Features First 2010 Data Press Release 2010 Data Brief Other End Use Surveys Commercial Buildings - CBECS Residential - RECS Transportation DOE Uses MECS Data Manufacturing Energy and Carbon Footprints Associated Analysis Manufacturing Energy Sankey Diagrams Manufacturing Energy Flows Tool Cost of Natural Gas Used in Manufacturing Sector Has Fallen MECS 2010 - Release date: September 6,

  17. Ground Gravity Survey | Open Energy Information

    Open Energy Info (EERE)

    Et Al., 2000) Dixie Valley Geothermal Area 1999 2000 Precise Gravimetry and Geothermal Reservoir Management Ground Gravity Survey At Dixie Valley Geothermal Area (Blackwell, Et...

  18. Aeromagnetic Survey (Nannini, 1986) | Open Energy Information

    Open Energy Info (EERE)

    These surveys are based on the magnetic susceptibility contrast between magmatic rocks at depth and the sedimentary formations above. References Raffaello Nannini (1986)...

  19. Wyoming State Geological Survey | Open Energy Information

    Open Energy Info (EERE)

    navigation, search Name: Wyoming State Geological Survey Abbreviation: WSGS Address: P.O. Box 1347 Place: Laramie, Wyoming Zip: 82073 Year Founded: 1933 Phone Number:...

  20. Light and dark: A survey of new physics ideas in the 1-100 MeV window

    SciTech Connect (OSTI)

    Pospelov, Maxim

    2013-11-07

    I review the set of theoretical ideas motivating experimental searches of light physics beyond Standard Model using the high-intensity electron beams. While 'dark photon' is the chief example of such physics, the other 'light and dark' states (e.g. 'Dark Higgses') are also of interest. I discuss particle physics, cosmology and astrophysics applications.

  1. Manufacturing Energy Consumption Survey (MECS) - Analysis & Projections -

    Gasoline and Diesel Fuel Update (EIA)

    U.S. Energy Information Administration (EIA) Manufacturing Energy Consumption Data Show Large Reductions in Both Manufacturing Energy Use and the Energy Intensity of Manufacturing Activity between 2002 and 2010 MECS 2010 - Release date: March 19, 2013 Total energy consumption in the manufacturing sector decreased by 17 percent from 2002 to 2010 (Figure 1), according to data from the U.S. Energy Information Administration's (EIA) Manufacturing Energy Consumption Survey (MECS). line chart:air

  2. Local Group dSph radio survey with ATCA (III): constraints on particle dark matter

    SciTech Connect (OSTI)

    Regis, Marco; Colafrancesco, Sergio; Profumo, Stefano; De Blok, W.J.G.; Massardi, Marcella; Richter, Laura E-mail: sergio.colafrancesco@wits.ac.za E-mail: blok@astron.nl E-mail: laura@ska.ac.za

    2014-10-01

    We performed a deep search for radio synchrotron emissions induced by weakly interacting massive particles (WIMPs) annihilation or decay in six dwarf spheroidal (dSph) galaxies of the Local Group. Observations were conducted with the Australia Telescope Compact Array (ATCA) at 16 cm wavelength, with an rms sensitivity better than 0.05 mJy/beam in each field. In this work, we first discuss the uncertainties associated with the modeling of the expected signal, such as the shape of the dark matter (DM) profile and the dSph magnetic properties. We then investigate the possibility that point-sources detected in the proximity of the dSph optical center might be due to the emission from a DM cuspy profile. No evidence for an extended emission over a size of few arcmin (which is the DM halo size) has been detected. We present the associated bounds on the WIMP parameter space for different annihilation/decay final states and for different astrophysical assumptions. If the confinement of electrons and positrons in the dSph is such that the majority of their power is radiated within the dSph region, we obtain constraints on the WIMP annihilation rate which are well below the thermal value for masses up to few TeV. On the other hand, for conservative assumptions on the dSph magnetic properties, the bounds can be dramatically relaxed. We show however that, within the next 10 years and regardless of the astrophysical assumptions, it will be possible to progressively close in on the full parameter space of WIMPs by searching for radio signals in dSphs with SKA and its precursors.

  3. CHEMISTRY IN INFRARED DARK CLOUD CLUMPS: A MOLECULAR LINE SURVEY AT 3 mm

    SciTech Connect (OSTI)

    Sanhueza, Patricio; Jackson, James M.; Foster, Jonathan B.; Finn, Susanna C.; Garay, Guido; Silva, Andrea

    2012-09-01

    We have observed 37 Infrared Dark Clouds (IRDCs), containing a total of 159 clumps, in high-density molecular tracers at 3 mm using the 22 m ATNF Mopra Telescope located in Australia. After determining kinematic distances, we eliminated clumps that are not located in IRDCs and clumps with a separation between them of less than one Mopra beam. Our final sample consists of 92 IRDC clumps. The most commonly detected molecular lines are (detection rates higher than 8%) N{sub 2}H{sup +}, HNC, HN{sup 13}C, HCO{sup +}, H{sup 13}CO{sup +}, HCN, C{sub 2}H, HC{sub 3}N, HNCO, and SiO. We investigate the behavior of the different molecular tracers and look for chemical variations as a function of an evolutionary sequence based on Spitzer IRAC and MIPS emission. We find that the molecular tracers behave differently through the evolutionary sequence and some of them can be used to yield useful relative age information. The presence of HNC and N{sub 2}H{sup +} lines does not depend on the star formation activity. On the other hand, HC{sub 3}N, HNCO, and SiO are predominantly detected in later stages of evolution. Optical depth calculations show that in IRDC clumps the N{sub 2}H{sup +} line is optically thin, the C{sub 2}H line is moderately optically thick, and HNC and HCO{sup +} are optically thick. The HCN hyperfine transitions are blended, and, in addition, show self-absorbed line profiles and extended wing emission. These factors combined prevent the use of HCN hyperfine transitions for the calculation of physical parameters. Total column densities of the different molecules, except C{sub 2}H, increase with the evolutionary stage of the clumps. Molecular abundances increase with the evolutionary stage for N{sub 2}H{sup +} and HCO{sup +}. The N{sub 2}H{sup +}/HCO{sup +} and N{sub 2}H{sup +}/HNC abundance ratios act as chemical clocks, increasing with the evolution of the clumps.

  4. 2015-Federal Viewpoint Survey Reports | Department of Energy

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

    5-Federal Viewpoint Survey Reports 2015-Federal Viewpoint Survey Reports The following highlight report focuses on the Department of Energy's areas of strengths and challenges, identifies areas of progress and opportunities for improvement. The Departments 2015 results are compared with the 2014 Government wide results. 2015_FEVS_AMR_Department_of_Energy.pdf (1.15 MB) 2015_FEVS_AES_Department_of_Energy.pdf (227 KB) Responsible Contacts Thomasina Mathews PROGRAM MANAGER E-mail

  5. 2-M Probe Survey | Open Energy Information

    Open Energy Info (EERE)

    Techniques A modified version of the 2 m temperature probe survey was tested at the Salt Wells Geothermal Area in 2005.2 This technique was used to measure temperatures at...

  6. Mediation Survey Form | Department of Energy

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

    PDF icon Mediation Survey Form More Documents & Publications Microsoft Word - GC Mediation Evaluation 2-06-09.doc Mediation Brochure FIA-12-0044 - In the Matter of Cynthia Brown...

  7. Constraints on a f(R) gravity dark energy model with early scaling evolution

    SciTech Connect (OSTI)

    Park, Chan-Gyung; Hwang, Jai-chan; Noh, Hyerim E-mail: jchan@knu.ac.kr

    2011-09-01

    The modified gravity with f(R) = R{sup 1+?} (? > 0) allows a scaling solution where the energy density of gravity sector follows the energy density of the dominant fluid. We present initial conditions of background and perturbation variables during the scaling evolution regime in the modified gravity. As a possible dark energy model we consider a gravity with a form f(R) = R{sup 1+?}+qR{sup ?n} (?1 < n ? 0) where the second term drives the late-time acceleration. We show that our f(R) gravity parameters are very sensitive to the baryon perturbation growth and baryon density power spectrum, and present observational constraints on the model parameters. We consider full perturbations of f(R) gravity. Our analysis suggests that only the parameter space extremely close to the ?CDM model is allowed with ??<5 10{sup ?6} and n?>?10{sup ?4}.

  8. Cosmological back-reaction in modified gravity and its implications for dark energy

    SciTech Connect (OSTI)

    Preston, Anthony W.H.; Morris, Tim R. E-mail: T.R.Morris@soton.ac.uk

    2014-09-01

    We study the effective stress-energy tensor induced by cosmological inhomogeneity in f(R)=R+c R{sup 2} and equivalent scalar-tensor theories, motivated both by models of early universe inflation and by phenomenological alternative cosmologies to the standard Λ-CDM. We use Green and Wald's framework for averaging over classical fluctuations of short-wavelength λ. By ensuring that the leading non-linear terms from the fluctuations of the Einstein terms and the corrections both contribute in the formal limit as λ→0, we derive a diffeomorphism invariant effective stress-energy tensor whose trace is non-vanishing and of the right sign to potentially account for the current acceleration of the universe. However a more phenomenologically acceptable dark energy model would be required if this effect were to fully account for the current acceleration.

  9. Maps of CMB lensing deflection from N-body simulations in Coupled Dark Energy Cosmologies

    SciTech Connect (OSTI)

    Carbone, Carmelita; Baldi, Marco; Baccigalupi, Carlo E-mail: marco.baldi5@unibo.it E-mail: bacci@sissa.it

    2013-09-01

    We produce lensing potential and deflection-angle maps in order to simulate the weak gravitational lensing of the Cosmic Microwave Background (CMB) via ray-tracing through the COupled Dark Energy Cosmological Simulations (CoDECS), the largest suite of N-body simulations to date for interacting Dark Energy cosmologies. The constructed maps faithfully reflect the N-body cosmic structures on a range of scales going from the arcminute to the degree scale, limited only by the resolution and extension of the simulations. We investigate the variation of the lensing pattern due to the underlying Dark Energy (DE) dynamics, characterised by different background and perturbation behaviours as a consequence of the interaction between the DE field and Cold Dark Matter (CDM). In particular, we study in detail the results from three cosmological models differing in the background and perturbations evolution at the epoch in which the lensing cross section is most effective, corresponding to a redshift of ∼ 1, with the purpose to isolate their imprints in the lensing observables, regardless of the compatibility of these models with present constraints. The scenarios investigated here include a reference ΛCDM cosmology, a standard coupled DE (cDE) scenario, and a ''bouncing'' cDE scenario. For the standard cDE scenario, we find that typical differences in the lensing potential result from two effects: the enhanced growth of linear CDM density fluctuations with respect to the ΛCDM case, and the modified nonlinear dynamics of collapsed structures induced by the DE-CDM interaction. As a consequence, CMB lensing highlights the DE impact in the cosmological expansion, even in the degenerate case where the amplitude of the linear matter density perturbations, parametrised through σ{sub 8}, is the same in both the standard cDE and ΛCDM cosmologies. For the ''bouncing'' scenario, we find that the two opposite behaviours of the lens density contrast and of the matter abundance lead to

  10. Environmental Survey preliminary report, Solar Energy Research Institute, Golden, Colorado

    SciTech Connect (OSTI)

    Not Available

    1988-10-01

    This report presents the preliminary findings of the first phase of the Environmental Survey of the US Department of Energy's (DOE) Solar Energy Research Institute (SERI), conducted December 14 through 18, 1987. The Survey is being conducted by an interdisciplinary team of environmental specialists, led and managed by the Office of Environment, Safety and Health's Office of Environmental Audit. The team includes outside experts supplied by private contractors. The objective of the Survey is to identify environmental problems and areas of environmental risk associated with SERI. The Survey covers all environmental media and all areas of environmental regulation. It is being performed in accordance with the DOE Environmental Survey Manual. The on-site phase of the Survey involves the review of existing site environmental data, observations of the operations carried on at SERI, and interviews with site personnel. 33 refs., 22 figs., 21 tabs.

  11. Residential Energy Consumption Survey (RECS) - Data - U.S. Energy...

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

    2001 RECS Survey Data 2009 | 2005 | 2001 | 1997 | 1993 | Previous Housing characteristics Consumption & expenditures Microdata Methodology Housing Characteristics Tables + EXPAND ...

  12. Select Results from the Energy Assessor Experiment in the 2012 Commercial Buildings Energy Consumption Survey

    U.S. Energy Information Administration (EIA) Indexed Site

    Select Results from the Energy Assessor Experiment in the 2012 Commercial Buildings Energy Consumption Survey December 2015 Independent Statistics & Analysis www.eia.gov U.S. Department of Energy Washington, DC 20585 U.S. Energy Information Administration | Select Results from the Energy Assessor Experiment in the 2012 Commercial Buildings Energy Consumption Survey i This report was prepared by the U.S. Energy Information Administration (EIA), the statistical and analytical agency within the

  13. Manufacturing Energy Consumption Survey (MECS) - Residential...

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

    the 2010 MECS show that energy consumption in the manufacturing sector decreased between 2006 and 2010 MECS 2006-2010 - Release date: March 28, 2012 Energy consumption in the U.S. ...

  14. Residential Energy Consumption Survey (RECS) - Analysis & Projections -

    Gasoline and Diesel Fuel Update (EIA)

    U.S. Energy Information Administration (EIA) About the RECS RECS Survey Forms RECS Maps RECS Terminology Archived Reports Has your company been contacted about the RECS Energy Supplier Survey (ESS)? State fact sheets Arizona household graph See state fact sheets › 2009 RECS Features Heating and cooling no longer majority of U.S. home energy use March 7, 2013 Newer U.S. homes are 30% larger but consume about as much energy as older homes February 12, 2013 Where does RECS square footage data

  15. Residential Energy Consumption Survey (RECS) - Analysis & Projections -

    U.S. Energy Information Administration (EIA) Indexed Site

    U.S. Energy Information Administration (EIA) About the RECS RECS Survey Forms RECS Maps RECS Terminology Archived Reports Has your company been contacted about the RECS Energy Supplier Survey (ESS)? State fact sheets Arizona household graph See state fact sheets › 2009 RECS Features Heating and cooling no longer majority of U.S. home energy use March 7, 2013 Newer U.S. homes are 30% larger but consume about as much energy as older homes February 12, 2013 Where does RECS square footage data

  16. Constraining dark matter late-time energy injection: decays and p-wave annihilations

    SciTech Connect (OSTI)

    Diamanti, Roberta; Mena, Olga; Palomares-Ruiz, Sergio; Vincent, Aaron C.; Lopez-Honorez, Laura E-mail: llopezho@vub.ac.be E-mail: sergio.palomares.ruiz@ific.uv.es

    2014-02-01

    We use the latest cosmic microwave background (CMB) observations to provide updated constraints on the dark matter lifetime as well as on p-wave suppressed annihilation cross sections in the 1 MeV to 1 TeV mass range. In contrast to scenarios with an s-wave dominated annihilation cross section, which mainly affect the CMB close to the last scattering surface, signatures associated with these scenarios essentially appear at low redshifts (z∼<50) when structure began to form, and thus manifest at lower multipoles in the CMB power spectrum. We use data from Planck, WMAP9, SPT and ACT, as well as Lyman–α measurements of the matter temperature at z ∼ 4 to set a 95% confidence level lower bound on the dark matter lifetime of ∼ 4 × 10{sup 25} s for m{sub χ} = 100 MeV. This bound becomes lower by an order of magnitude at m{sub χ} = 1 TeV due to inefficient energy deposition into the intergalactic medium. We also show that structure formation can enhance the effect of p-wave suppressed annihilation cross sections by many orders of magnitude with respect to the background cosmological rate, although even with this enhancement, CMB constraints are not yet strong enough to reach the thermal relic value of the cross section.

  17. Residential Energy Consumption Survey (RECS) - Data - U.S. Energy...

    U.S. Energy Information Administration (EIA) Indexed Site

    9 RECS Survey Data 2009 | 2005 | 2001 | 1997 | 1993 | Previous Housing characteristics Consumption & expenditures Microdata Methodology Housing characteristics tables + EXPAND ALL ...

  18. Residential Energy Consumption Survey (RECS) - Data - U.S. Energy...

    U.S. Energy Information Administration (EIA) Indexed Site

    5 RECS Survey Data 2009 | 2005 | 2001 | 1997 | 1993 | Previous Housing characteristics Consumption & expenditures Microdata Housing Characteristics Tables + EXPAND ALL Floorspace - ...

  19. Reflection Survey (Ozkocak, 1985) | Open Energy Information

    Open Energy Info (EERE)

    Of Geothermal Energy For Electric Power Production And Space Heating, Florence 1984, Section 2- Geothermal Resources Additional References Retrieved from "http:...

  20. Static Temperature Survey | Open Energy Information

    Open Energy Info (EERE)

    2003. Estimation of static formation temperatures in geothermal wells. Energy conversion and management. 44(8):1343-1355. Page Area Activity Start Date Activity...

  1. Lyman Alpha Emitting Galaxies at 2 < z < 3: Towards a Calibrated Probe of Dark Energy

    SciTech Connect (OSTI)

    Caryl Gronwall

    2012-12-03

    The goal of this project was to establish the physical properties of Ly{alpha} emitting galaxies from redshifts of 2 to 3 in order to better calibrate the use of LAEs as probes of the large scale structure of the universe for upcoming dark energy experiments, such as the Hobby Eberly Telescope Dark Energy Experiment (HETDEX). We have obtained narrow-band imaging of the Extended Chandra Deep Field South (ECDF-S) in two different narrow-band filters centered at Ly{alpha} at z=2.1 and 3.1. The resulting of samples of LAEs were used to determine the LAE luminosity function, equivalent width distribution and clustering properties (bias) of LAEs at these redshifts. While the results from the ECDF-S appear robust, they are based on a single field. To explore the effects of cosmic variance and galaxy environment on the physical properties of LAEs, we have also obtained narrow-band data at both redshifts (z = 2:1 and 3:1) in three additional fields (SDSS 1030+-05, the Extended Hubble Deep Field South, and CW 1255+01). The narrow-band imaging data has been reduced and LAE catalogs are being generated. We have calculated preliminary luminosity functions, equivalent width distributions, and clustering properties. We have also obtained follow-up spectroscopy in the optical (using VLT/FORS) and in the near-infrared (using Magellan/MMIRS). Since individual LAEs have too little S/N to enable meaningful fits for stellar population parameters, our previous work has analyzed stacked Spectral Energy Distributions (SEDs). SED fitting was performed on several subsets of LAEs selected by their rest-UV luminosity, UV spectral slope, Ly alpha luminosity, Equivalent Width, or rest-optical (IRAC) luminosity.

  2. Cool Trends in District Energy: A Survey of Thermal Energy Storage...

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

    This 2005 survey considers the use of cool Thermal Energy Storage (TES) in District Cooling utility applications. cooltrendsinde.pdf (86.08 KB) More Documents & Publications ...

  3. Phantom of the Hartle–Hawking instanton: Connecting inflation with dark energy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Chen, Pisin; Qiu, Taotao; Yeom, Dong -han

    2016-02-20

    If the Hartle–Hawking wave function is the correct boundary condition of our universe, the history of our universe will be well approximated by an instanton. Although this instanton should be classicalized at infinity, as long as we are observing a process of each history, we may detect a non-classicalized part of field combinations. When we apply it to a dark energy model, this non-classicalized part of fields can be well embedded to a quintessence and a phantom model, i.e., a quintom model. Because of the property of complexified instantons, the phantomness will be naturally free from a big rip singularity.more » This phantomness does not cause perturbative instabilities, as it is an effect emergent from the entire wave function. Lastly, our work may thus provide a theoretical basis for the quintom models, whose equation of state can cross the cosmological constant boundary phenomenologically.« less

  4. Quantum fate of singularities in a dark-energy dominated universe

    SciTech Connect (OSTI)

    Bouhmadi-Lopez, Mariam; Kiefer, Claus; Sandhoefer, Barbara; Moniz, Paulo Vargas

    2009-06-15

    Classical models for dark energy can exhibit a variety of singularities, many of which occur for scale factors much bigger than the Planck length. We address here the issue of whether some of these singularities, the big freeze and the big demarrage, can be avoided in quantum cosmology. We use the framework of quantum geometrodynamics. We restrict our attention to a class of models whose matter content can be described by a generalized Chaplygin gas and be represented by a scalar field with an appropriate potential. Employing the DeWitt criterion that the wave function be zero at the classical singularity, we show that a class of solutions to the Wheeler-DeWitt equation fulfilling this condition can be found. These solutions thus avoid the classical singularity. We discuss the reasons for the remaining ambiguity in fixing the solution.

  5. Residential Energy Consumption Survey (RECS) - Analysis & Projections...

    Gasoline and Diesel Fuel Update (EIA)

    How does EIA estimate energy consumption and end uses in U.S. homes? RECS 2009 - Release date: ... ESS gathers data on how much electricity, natural gas, fuel oil, and propane were ...

  6. Residential Energy Consumption Survey: Housing Characteristics...

    Gasoline and Diesel Fuel Update (EIA)

    either air or liquid as the working fluid. It does not refer :<: passive collection of solar thermal energy. Fuel Oil Paid by Household: The household paid directly to the fuel...

  7. Constraints on dark energy from new observations including Pan-STARRS

    SciTech Connect (OSTI)

    Zheng, Wei [Department of Physics, Nanjing University, Nanjing, 210093 China (China); Li, Si-Yu [Theoretical Physics Division, Institute of High Energy Physics, Chinese Academy of Science, P.O. Box 918-4, Beijing, 100049 (China); Li, Hong; Xia, Jun-Qing [Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Science, P.O. Box 918-3, Beijing, 100049 (China); Li, Mingzhe [Interdisciplinary Center for Theoretical Study, University of Science and Technology of China, Hefei, Anhui, 230026 China (China); Lu, Tan, E-mail: physicsweiwei@gmail.com, E-mail: lisy@ihep.ac.cn, E-mail: hongli@ihep.ac.cn, E-mail: xiajq@ihep.ac.cn, E-mail: limz@ustc.edu.cn, E-mail: t.lu@pmo.ac.cn [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing, 210008 China (China)

    2014-08-01

    In this paper, we set the new limits on the equation of state parameter (EoS) of dark energy with the observations of cosmic microwave background radiation (CMB) from Planck satellite, the type Ia supernovae from Pan-STARRS and the baryon acoustic oscillation (BAO). We consider two parametrization forms of EoS: a constant w and time evolving w(a)=w{sub 0}+w{sub a}(1-a). The results show that with a constant EoS, w=-1.1410.075 68% C.L.), which is consistent with ?CDM at about 2? confidence level. For a time evolving w(a) model, we get w{sub 0}=-1.09{sup +0.16}{sub -0.18} 1? C.L.), w{sub a}=-0.34{sup +0.87}{sub -0.51} 1? C.L.), and in this case ?CDM can be comparable with our observational data at 1? confidence level. In order to do the parametrization independent analysis, additionally we adopt the so called principal component analysis (PCA) method, in which we divide redshift range into several bins and assume w as a constant in each redshift bin (bin-w). In such bin-w scenario, we find that for most of the bins cosmological constant can be comparable with the data, however, there exists few bins which give w deviating from ?CDM at more than 2? confidence level, which shows a weak hint for the time evolving behavior of dark energy. To further confirm this hint, we need more data with higher precision.

  8. Commercial Buildings Energy Consumption Survey (CBECS) - U.S. Energy

    Gasoline and Diesel Fuel Update (EIA)

    Information Administration (EIA) Survey Background and Technical Information Survey Background The commercial sector encompasses a vast range of building types-service businesses, such as retail and wholesale stores, hotels and motels, restaurants, and hospitals, as well as certain buildings that would not be considered "commercial" in a traditional economic sense, such as public and private schools, correctional institutions, and religious and fraternal organizations. Excluded

  9. Bibliographic survey of medium energy inclusive reaction data

    SciTech Connect (OSTI)

    Arthur, E.D.; Madland, D.G.; McClellan, D.M.

    1986-04-01

    A bibliographic survey of inclusive reaction data (experimental and theoretical) for several projectile types having energies between 50 and 1000 MeV has been completed. Approximately one thousand references selected from this survey describe the current state of knowledge for particle-induced inclusive reaction data. The search covered data for the following projectiles: p, d, t, /sup 3/He, /sup 4/He, and lithium ions.

  10. Residential Energy Consumption Survey (RECS) - U.S. Energy Information...

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

    This information is combined with data from energy suppliers to these homes to estimate energy costs and usage for heating, cooling, appliances and other end uses - information ...

  11. Sample design for the residential energy consumption survey

    SciTech Connect (OSTI)

    Not Available

    1994-08-01

    The purpose of this report is to provide detailed information about the multistage area-probability sample design used for the Residential Energy Consumption Survey (RECS). It is intended as a technical report, for use by statisticians, to better understand the theory and procedures followed in the creation of the RECS sample frame. For a more cursory overview of the RECS sample design, refer to the appendix entitled ``How the Survey was Conducted,`` which is included in the statistical reports produced for each RECS survey year.

  12. ENERGY MEASUREMENTS GROUP EG&G Survey Report

    Office of Legacy Management (LM)

    kL2' . ",- - &j EGG0 ENERGY MEASUREMENTS GROUP EG&G Survey Report NRC-81 09 April 1981 . AN AERIAL RADIOLOGIC SURVEY OF THE STEPAN CHEMCIAL COMPANY AND SURROUNDING AREA MAYWOOD, N E W JERSEY DATE OF SURVEY: 26 JANUARY 1981 J.R. Mueller Project Director S.A. Gunn Project Scientist APPROVED FOR DISTRIBUTION W . John Tipton, Head Radiation Sciences Section This Document is UNCLASSIFIED G. P. Stobie Classification Officer This work was performed by EG&G for the United States Nuclear

  13. User-needs study for the 1992 Commercial Buildings Energy Consumption Survey. [Energy Consumption Series

    SciTech Connect (OSTI)

    Not Available

    1992-09-01

    The Commercial Buildings Energy Consumption Survey (CBECS) that is conducted by the Energy Information Administration (EIA) is the primary source of energy data for commercial buildings in the United States. The survey began in 1979 and has subsequently been conducted in 1983, 1986, and 1989. The next survey will cover energy consumption during the year 1992. The building characteristic data will be collected between August 1992 and early December 1992. Requests for energy consumption data are mailed to the energy suppliers in January 1993, with data due by March 1993. Before each survey is sent into the field, the data users' needs are thoroughly assessed. The purpose of this report is to document the findings of that user-needs assessment for the 1992 survey.

  14. Constraining dark energy models using the lookback time to galaxy clusters and the age of the universe

    SciTech Connect (OSTI)

    Capozziello, S.; Cardone, V.F.; Funaro, M.; Andreon, S.

    2004-12-15

    An impressive amount of different astrophysical data converges towards the picture of a spatially flat Universe undergoing today a phase of accelerated expansion. The nature of the dark energy dominating the energy content of the Universe is still unknown, and a lot of different scenarios are viable candidates to explain cosmic acceleration. Most of the methods employed to test these cosmological models are essentially based on distance measurements to a particular class of objects. A different method, based on the lookback time to galaxy clusters and the age of the Universe, is used here. In particular, we constrain the characterizing parameters of three classes of dark energy cosmological models to see whether they are in agreement with this kind of data, based on time measurements rather than distance observations.

  15. Commercial Buildings Energy Consumption Survey (CBECS) - Analysis &

    Gasoline and Diesel Fuel Update (EIA)

    Projections - U.S. Energy Information Administration (EIA) All Reports & Publications Search By: Go Pick a date range: From: To: Go Commercial Buildings Available formats Commercial Buildings Energy Consumption Survey 2012 - Detailed Tables Released: May 17, 2016 The 2012 CBECS consumption and expenditures detailed tables are comprised of Tables C1-C38, which cover overall electricity, natural gas, fuel oil and district heat consumption, and tables E1-E11, which disaggregate the same

  16. Residential Energy Consumption Survey (RECS) - Data - U.S. Energy

    U.S. Energy Information Administration (EIA) Indexed Site

    Information Administration (EIA) 3 RECS Survey Data 2009 | 2005 | 2001 | 1997 | 1993 | Previous Housing characteristics Consumption & expenditures Microdata Methodology Housing Characteristics Tables Topical Sections Entire Section All Detailed Tables PDF Tables: HC1 Household Characteristics, Million U.S. Households Presents data relating to location, type, ownership, age, size, construction, and householder demographic and income characteristics. PDF Tables: HC2 Space Heating, Million

  17. A survey of state clean energy fund support for biomass

    SciTech Connect (OSTI)

    Fitzgerald, Garrett; Bolinger, Mark; Wiser, Ryan

    2004-08-20

    This survey reviews efforts by CESA member clean energy funds to promote the use of biomass as a renewable energy source. For each fund, details are provided regarding biomass eligibility for support, specific programs offering support to biomass projects, and examples of supported biomass projects (if available). For the purposes of this survey, biomass is defined to include bio-product gasification, combustion, co-firing, biofuel production, and the combustion of landfill gas, though not all of the programs reviewed here take so wide a definition. Programs offered by non-CESA member funds fall outside the scope of this survey. To date, three funds--the California Energy Commission, Wisconsin Focus on Energy, and the New York State Energy Research and Development Authority--have offered programs targeted specifically at the use of biomass as a renewable energy source. We begin by reviewing efforts in these three funds, and then proceed to cover programs in other funds that have provided support to biomass projects when the opportunity has arisen, but otherwise do not differentially target biomass relative to other renewable technologies.

  18. New Constraints on Dark Energy from Chandra X-rayObservations of the Largest Relaxed Galaxy Clusters

    SciTech Connect (OSTI)

    Allen, S.W.; Rapetti, D.A.; /KIPAC, Menlo Park; Schmidt, R.W.; /Heidelberg, Astron. Rechen Inst.; Ebeling, H.; /Inst. Astron., Honolulu; Morris, G.; /KIPAC, Menlo Park; Fabian, A.C.; /Cambridge U., Inst. of Astron.

    2007-06-06

    We present constraints on the mean matter density, {Omega}{sub m}, dark energy density, {Omega}{sub DE}, and the dark energy equation of state parameter, w, using Chandra measurements of the X-ray gas mass fraction (fgas) in 42 hot (kT > 5keV), X-ray luminous, dynamically relaxed galaxy clusters spanning the redshift range 0.05 < z < 1.1. Using only the fgas data for the 6 lowest redshift clusters at z < 0.15, for which dark energy has a negligible effect on the measurements, we measure {Omega}{sub m}=0.28{+-}0.06 (68% confidence, using standard priors on the Hubble Constant, H{sub 0}, and mean baryon density, {Omega}{sub b}h{sup 2}). Analyzing the data for all 42 clusters, employing only weak priors on H{sub 0} and {Omega}{sub b}h{sup 2}, we obtain a similar result on {Omega}{sub m} and detect the effects of dark energy on the distances to the clusters at {approx}99.99% confidence, with {Omega}{sub DE}=0.86{+-}0.21 for a non-flat LCDM model. The detection of dark energy is comparable in significance to recent SNIa studies and represents strong, independent evidence for cosmic acceleration. Systematic scatter remains undetected in the f{sub gas} data, despite a weighted mean statistical scatter in the distance measurements of only {approx}5%. For a flat cosmology with constant w, we measure {Omega}{sub m}=0.28{+-}0.06 and w=-1.14{+-}0.31. Combining the fgas data with independent constraints from CMB and SNIa studies removes the need for priors on {Omega}{sub b}h{sup 2} and H{sub 0} and leads to tighter constraints: {Omega}{sub m}=0.253{+-}0.021 and w=-0.98{+-}0.07 for the same constant-w model. More general analyses in which we relax the assumption of flatness and/or allow evolution in w remain consistent with the cosmological constant paradigm. Our analysis includes conservative allowances for systematic uncertainties. The small systematic scatter and tight constraints bode well for future dark energy studies using the f{sub gas} method.

  19. Self-similar cosmological solutions with dark energy. II. Black holes, naked singularities, and wormholes

    SciTech Connect (OSTI)

    Maeda, Hideki; Harada, Tomohiro; Carr, B. J.

    2008-01-15

    We use a combination of numerical and analytical methods, exploiting the equations derived in a preceding paper, to classify all spherically symmetric self-similar solutions which are asymptotically Friedmann at large distances and contain a perfect fluid with equation of state p=({gamma}-1){mu} with 0<{gamma}<2/3. The expansion of the Friedmann universe is accelerated in this case. We find a one-parameter family of self-similar solutions representing a black hole embedded in a Friedmann background. This suggests that, in contrast to the positive pressure case, black holes in a universe with dark energy can grow as fast as the Hubble horizon if they are not too large. There are also self-similar solutions which contain a central naked singularity with negative mass and solutions which represent a Friedmann universe connected to either another Friedmann universe or some other cosmological model. The latter are interpreted as self-similar cosmological white hole or wormhole solutions. The throats of these wormholes are defined as two-dimensional spheres with minimal area on a spacelike hypersurface and they are all nontraversable because of the absence of a past null infinity.

  20. Manufacturing Energy Consumption Survey (MECS) - Data - U.S. Energy

    U.S. Energy Information Administration (EIA) Indexed Site

    Information Administration (EIA) 6 MECS Survey Data 2010 | 2006 | 2002 | 1998 | 1994 | 1991 | Archive Data Methodology & Forms 2006 Data Tables Revision notice (November 2009): Tables 1.1, 1.2, 2.1, 2.2, 3.1, 3.2, 3.5, 4.1 and 4.2 have been slightly revised due to further editing. The revisions in XLS are indicated with a value of "R" in an adjacent column. In the PDF versions, the revised values are superscripted with an "R". No further revisions are anticipated for

  1. Residential Energy Consumption Survey (RECS) - U.S. Energy Information...

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

    Industrial and electric power sectors drive projected growth in U.S. natural gas use May 26, 2016 Declining energy prices lower the cost of living May 3, 2016 All 70 related ...

  2. Commercial Buildings Energy Consumption Survey (CBECS) - U.S. Energy

    Gasoline and Diesel Fuel Update (EIA)

    Information Administration (EIA) Estimation of Energy End-use Consumption CBECS 2012 - Release date: March 18, 2016 2012 CBECS The energy end-use consumption tables for the 2012 CBECS (Detailed Tables E1-E 11) provide estimates of the amount of electricity, natural gas, fuel oil, and district heat used for ten end uses: space heating, cooling, ventilation, water heating, lighting, cooking, refrigeration, computing (including servers), office equipment, and other uses. Although details vary

  3. OSTIblog Articles in the dark energy Topic | OSTI, US Dept of Energy Office

    Office of Scientific and Technical Information (OSTI)

    of Scientific and Technical Information energy Topic OSTI's Amazing Dr. Watson by Kathy Chambers 17 Apr, 2013 in Products and Content 5440 DrWatsonBlog.jpg OSTI's Amazing Dr. Watson Read more about 5440 During the past year, Dr. William N. Watson, physicist, of DOE/OSTI's staff has posted quite a few very interesting white papers in OSTI's monthly Science Showcase on OSTI's Home Page. This quiet, unassuming man crafts prolific papers on popular science topics of interest to the Department of

  4. LSST and the Physics of the Dark Universe

    ScienceCinema (OSTI)

    Tyson, Anthony [UC Davis, California, United States

    2010-09-01

    The physics that underlies the accelerating cosmic expansion is unknown. This, 'dark energy' and the equally mysterious 'dark matter' comprise most of the mass-energy of the universe and are outside the standard model. Recent advances in optics, detectors, and information technology, has led to the design of a facility that will repeatedly image an unprecedented volume of the universe: LSST. For the first time, the sky will be surveyed wide, deep and fast. The history of astronomy has taught us repeatedly that there are surprises whenever we view the sky in a new way. I will review the technology of LSST, and focus on several independent probes of the nature of dark energy and dark matter. These new investigations will rely on the statistical precision obtainable with billions of galaxies.

  5. Manufacturing Energy Consumption Survey (MECS) - U.S. Energy Information

    Gasoline and Diesel Fuel Update (EIA)

    Administration (EIA) MECS Terminology A B C D E F G H I J K L M N O P Q R S T U V W XYZ B Barrel: A volumetric unit of measure equivalent to 42 U.S. gallons. Biomass: Organic nonfossil material of biological origin constituting a renewable energy source. Blast Furnace: A shaft furnace in which solid fuel (coke) is burned with an air blast to smelt ore in a continuous operation. Blast Furnace Gas: The waste combustible gas generated in a blast furnace when iron ore is being reduced with coke

  6. Category:Static Temperature Survey | Open Energy Information

    Open Energy Info (EERE)

    Static Temperature Survey Jump to: navigation, search Geothermalpower.jpg Looking for the Static Temperature Survey page? For detailed information on Static Temperature Survey,...

  7. OSTIblog Articles in the dark Topic | OSTI, US Dept of Energy Office of

    Office of Scientific and Technical Information (OSTI)

    Scientific and Technical Information Topic Dark Archives by Mark Martin 04 Aug, 2011 in Technology I have to admit that I am truly a science fiction and fantasy geek. Blame it on growing up on a steady diet of Star Wars and Transformers. This bit of background information helps explain why I smile internally whenever I get the chance to talk about dark archives. Those words call to mind a picture of some mysterious, powerful object at the center of an epic story, like The Lord of the Rings.

  8. Current trends in non-accelerator particle physics: 1, Neutrino mass and oscillation. 2, High energy neutrino astrophysics. 3, Detection of dark matter. 4, Search for strange quark matter. 5, Magnetic monopole searches

    SciTech Connect (OSTI)

    He, Yudong |

    1995-07-01

    This report is a compilation of papers reflecting current trends in non-accelerator particle physics, corresponding to talks that its author was invited to present at the Workshop on Tibet Cosmic Ray Experiment and Related Physics Topics held in Beijing, China, April 4--13, 1995. The papers are entitled `Neutrino Mass and Oscillation`, `High Energy Neutrino Astrophysics`, `Detection of Dark Matter`, `Search for Strange Quark Matter`, and `Magnetic Monopole Searches`. The report is introduced by a survey of the field and a brief description of each of the author`s papers.

  9. Dark Matter Theory

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

    Dark Matter Theory Dark Matter Theory Understanding discoveries at the Energy, Intensity, and Cosmic Frontiers Get Expertise Rajan Gupta (505) 667-7664 Email Bruce Carlsten (505) 667-5657 Email Dark Matter Theory The existence of dark matter can be traced back to the pioneering discoveries of Fritz Zwicky and Jan Oort that the motion of galaxies in the Coma cluster, and of nearby stars in our own Galaxy, do not follow the expected motion based on Newton's law of gravity and the observed visible

  10. On dark degeneracy and interacting models

    SciTech Connect (OSTI)

    Carneiro, S.; Borges, H.A. E-mail: humberto@ufba.br

    2014-06-01

    Cosmological background observations cannot fix the dark energy equation of state, which is related to a degeneracy in the definition of the dark sector components. Here we show that this degeneracy can be broken at perturbation level by imposing two observational properties on dark matter. First, dark matter is defined as the clustering component we observe in large scale structures. This definition is meaningful only if dark energy is unperturbed, which is achieved if we additionally assume, as a second condition, that dark matter is cold, i.e. non-relativistic. As a consequence, dark energy models with equation-of-state parameter −1 ≤ ω < 0 are reduced to two observationally distinguishable classes with ω = −1, equally competitive when tested against observations. The first comprises the ΛCDM model with constant dark energy density. The second consists of interacting models with an energy flux from dark energy to dark matter.

  11. Supercomputing Sheds Light on the Dark Universe

    SciTech Connect (OSTI)

    Salman Habib

    2012-11-15

    At Argonne National Laboratory, scientists are using supercomputers to shed light on one of the great mysteries in science today, the Dark Universe. With Mira, a petascale supercomputer at the Argonne Leadership Computing Facility, a team led by physicists Salman Habib and Katrin Heitmann will run the largest, most complex simulation of the universe ever attempted. By contrasting the results from Mira with state-of-the-art telescope surveys, the scientists hope to gain new insights into the distribution of matter in the universe, advancing future investigations of dark energy and dark matter into a new realm. The team's research was named a finalist for the 2012 Gordon Bell Prize, an award recognizing outstanding achievement in high-performance computing.

  12. Transportation Energy Survey Data Book 1.1

    SciTech Connect (OSTI)

    Gurikova, T

    2002-06-18

    vehicles. There are three ways to achieve this goal: efficiency, substitution, or less travel. A reduction in oil usage will result in a reduction of carbon emissions. Successful transition to alternative types of fuel and advanced technology vehicles may depend on awareness of U.S. dependence on imported oil and the U.S. energy situation. Successful transition may also depend on knowledge of alternative types of fuels and advanced technologies. The ''Transportation Energy Survey Data Book 1.1'' examines the public's knowledge, beliefs and expectations of the energy situation in the United States and transportation energy-related issues. The data presented in the report have been drawn from multiple sources: surveys conducted by the Opinion Research Corporation International (ORCI) for National Renewable Energy Laboratory (NREL) that are commissioned and funded by OTT, Gallup polls, ABC News/Washington Post polls, NBC News/Wall Street Journal polls, polls conducted by the Ipsos-Reid Corporation, as well articles from The Washington Post (2001) and other sources. All surveys are telephone interviews conducted with randomly selected national samples of adults 18 years of age and older. Almost all surveys were conducted before the September 11, 2001 terrorist attacks, with the only exceptions being the November 2001 ORCI survey and the November 2001 survey conducted by the Ipsos-Reid Corporation.

  13. THE WiggleZ DARK ENERGY SURVEY: GALAXY EVOLUTION AT 0.25 {<=...

    Office of Scientific and Technical Information (OSTI)

    University of Queensland, Brisbane, QLD 4072 (Australia) Department of Physics, Math, and Astronomy, California Institute of Technology, MC 405-47, 1200, East California...

  14. Wide-Field Lensing Mass Maps from Dark Energy Survey Science...

    Office of Scientific and Technical Information (OSTI)

    ; 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. ; ...

  15. Wide-field lensing mass maps from Dark Energy Survey science...

    Office of Scientific and Technical Information (OSTI)

    A. A. ; Romer, A. K. ; Roodman, A. ; Sanchez, E. ; Scarpine, V. ; Sevilla, I. ; Smith, R. C. ; Soares-Santos, M. ; Sobreira, F. ; Suchyta, E. ; Swanson, M. E. C. ; Tarle, G. ...

  16. Dark Matters

    ScienceCinema (OSTI)

    Joseph Silk

    2010-01-08

    One of the greatest mysteries in the cosmos is that it is mostly dark.  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.  I will describe the complex interplay between galaxy formation and dark matter detectability and review recent attempts to measure particle dark matter by direct and indirect means.

  17. World Energy Resources program U. S. Geological Survey

    SciTech Connect (OSTI)

    Masters, C.D.

    1986-05-01

    In 1973, with the OPEC embargo, the US was jarred into the world of insecure energy supplies - a harsh reality considering that throughout much of our history we had sufficient domestic supplies of oil and gas to meet all of our requirements. The US Government's response in 1973 was to assess domestic oil and gas potential, which was found to be substantial but nonetheless short of long-term requirements. Born of the need to become more certain about foreign as well has domestic resources, and working in conjunction with the Foreign Energy Supply Assessment Program of the US Department of Energy, the US Geological Survey undertook a program to develop a technical understanding of the reserves and undiscovered recoverable resources of petroleum in every basin in the world with petroleum potential. The World Energy Resources Program prepared an assessment of ultimate resources of crude oil for the World Petroleum Congress (WPC) in 1983, and a revision and update (including nature gas, crude oil, extra heavy oil, and tar sands) are planned for WPC in 1987. This poster session attempts to engender awareness of our scenario of world ultimate petroleum occurrence and to show some elements of the geology that guided our thinking.

  18. Category:Near Infrared Surveys | Open Energy Information

    Open Energy Info (EERE)

    Infrared Surveys Retrieved from "http:en.openei.orgwindex.php?titleCategory:NearInfraredSurveys&oldid794164" Feedback Contact needs updating Image needs updating...

  19. Hubei Electric Power Survey Design Institute | Open Energy Information

    Open Energy Info (EERE)

    Survey Design Institute Jump to: navigation, search Name: Hubei Electric Power Survey&Design Institute Place: Hubei Province, China Product: Wuhan-based power project design and...

  20. Ground Gravity Survey At Coso Geothermal Area (1980) | Open Energy...

    Open Energy Info (EERE)

    Ground Gravity Survey At Coso Geothermal Area (1980) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Coso Geothermal...

  1. Category:Airborne Gravity Survey | Open Energy Information

    Open Energy Info (EERE)

    Category Edit History Category:Airborne Gravity Survey Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Geothermalpower.jpg Looking for the Airborne Gravity Survey...

  2. Oregon National Register and Survey Program Webpage | Open Energy...

    Open Energy Info (EERE)

    National Register and Survey Program Webpage Jump to: navigation, search OpenEI Reference LibraryAdd to library Web Site: Oregon National Register and Survey Program Webpage...

  3. Cool Trends on Campus: A Survey of Thermal Energy Storage Use in Campus

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

    District Energy Systems, May 2005 | Department of Energy on Campus: A Survey of Thermal Energy Storage Use in Campus District Energy Systems, May 2005 Cool Trends on Campus: A Survey of Thermal Energy Storage Use in Campus District Energy Systems, May 2005 A survey was conducted to develop a database documenting and quantifying the use of Thermal Energy Storage (TES) in campus applications. cool_trends_on_campus.pdf (97.88 KB) More Documents & Publications Cool Trends in District Energy:

  4. Energy Efficiency in Small Server Rooms: Field Surveys and Findings

    SciTech Connect (OSTI)

    Cheung, Iris; Greenberg, Steve; Mahdavi, Roozbeh; Brown, Richard; Tschudi, William

    2014-08-11

    Fifty-seven percent of US servers are housed in server closets, server rooms, and localized data centers, in what are commonly referred to as small server rooms, which comprise 99percent of all server spaces in the US. While many mid-tier and enterprise-class data centers are owned by large corporations that consider energy efficiency a goal to minimize business operating costs, small server rooms typically are not similarly motivated. They are characterized by decentralized ownership and management and come in many configurations, which creates a unique set of efficiency challenges. To develop energy efficiency strategies for these spaces, we surveyed 30 small server rooms across eight institutions, and selected four of them for detailed assessments. The four rooms had Power Usage Effectiveness (PUE) values ranging from 1.5 to 2.1. Energy saving opportunities ranged from no- to low-cost measures such as raising cooling set points and better airflow management, to more involved but cost-effective measures including server consolidation and virtualization, and dedicated cooling with economizers. We found that inefficiencies mainly resulted from organizational rather than technical issues. Because of the inherent space and resource limitations, the most effective measure is to operate servers through energy-efficient cloud-based services or well-managed larger data centers, rather than server rooms. Backup power requirement, and IT and cooling efficiency should be evaluated to minimize energy waste in the server space. Utility programs are instrumental in raising awareness and spreading technical knowledge on server operation, and the implementation of energy efficiency measures in small server rooms.

  5. Search for Dark Matter in Events with One Jet and Missing Transverse Energy in pp̄ Collisions at √s=1.96 TeV

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aaltonen, T.; Álvarez González, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; et al

    2012-05-23

    We present the results of a search for dark matter production in the monojet signature. We analyze a sample of Tevatron pp̄ collisions at √s=1.96 TeV corresponding to an integrated luminosity of 6.7 fb⁻¹ recorded by the CDF II detector. In events with large missing transverse energy and one energetic jet, we find good agreement between the standard model prediction and the observed data. We set 90% confidence level upper limits on the dark matter production rate. The limits are translated into bounds on nucleon-dark matter scattering rates which are competitive with current direct detection bounds on spin-independent interaction belowmore » a dark matter candidate mass of 5 GeV/c², and on spin-dependent interactions up to masses of 200 GeV/c².« less

  6. Search for Dark Matter in Events with One Jet and Missing Transverse Energy in pp? Collisions at ?s=1.96 TeV

    SciTech Connect (OSTI)

    Aaltonen, T.; lvarez Gonzlez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Bai, Y.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bisello, D.; Bizjak, I.; Bland, K. R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H. S.; Burkett, K.; Busetto, G.; Bussey, P.; Buzatu, A.; Calamba, A.; Calancha, C.; Camarda, S.; Campanelli, M.; Campbell, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Carron, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Chlebana, F.; Cho, K.; Chokheli, D.; Chung, W. H.; Chung, Y. S.; Ciocci, M. A.; Clark, A.; Clarke, C.; Compostella, G.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Crescioli, F.; Cuevas, J.; Culbertson, R.; Dagenhart, D.; dAscenzo, N.; Datta, M.; de Barbaro, P.; DellOrso, M.; Demortier, L.; Deninno, M.; Devoto, F.; dErrico, M.; Di Canto, A.; Di Ruzza, B.; Dittmann, J. R.; DOnofrio, M.; Donati, S.; Dong, P.; Dorigo, M.; Dorigo, T.; Ebina, K.; Elagin, A.; Eppig, A.; Erbacher, R.; Errede, S.; Ershaidat, N.; Eusebi, R.; Farrington, S.; Feindt, M.; Fernandez, J. P.; Field, R.; Flanagan, G.; Forrest, R.; Fox, P. J.; Frank, M. J.; Franklin, M.; Freeman, J. C.; Funakoshi, Y.; Furic, I.; Gallinaro, M.; Garcia, J. E.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Giannetti, P.; Gibson, K.; Ginsburg, C. M.; Giokaris, N.; Giromini, P.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Goldschmidt, N.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; Gonzlez, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Grinstein, S.; Grosso-Pilcher, C.; Group, R. C.; Guimaraes da Costa, J.; Hahn, S. R.; Halkiadakis, E.; Hamaguchi, A.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, D.; Hare, M.; Harnik, R.; Harr, R. F.; Hatakeyama, K.; Hays, C.; Heck, M.; Heinrich, J.; Herndon, M.; Hewamanage, S.; Hocker, A.; Hopkins, W.; Horn, D.; Hou, S.; Hughes, R. E.; Hurwitz, M.; Husemann, U.; Hussain, N.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jindariani, S.; Jones, M.; Joo, K. K.; Jun, S. Y.; Junk, T. R.; Kamon, T.; Karchin, P. E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Khotilovich, V.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, J. E.; Kim, M. J.; Kim, S. B.; Kim, S. H.; Kim, Y. K.; Kim, Y. J.; Kimura, N.; Kirby, M.; Klimenko, S.; Knoepfel, K.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Krop, D.; Kruse, M.; Krutelyov, V.; Kuhr, T.; Kurata, M.; Kwang, S.; Laasanen, A. T.; Lami, S.; Lammel, S.; Lancaster, M.; Lander, R. L.; Lannon, K.; Lath, A.; Latino, G.; LeCompte, T.; Lee, E.; Lee, H. S.; Lee, J. S.; Lee, S. W.; Leo, S.; Leone, S.; Lewis, J. D.; Limosani, A.; Lin, C.-J.; Lindgren, M.; Lipeles, E.; Lister, A.; Litvintsev, D. O.; Liu, C.; Liu, H.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucchesi, D.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maeshima, K.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Margaroli, F.; Marino, C.; Martnez, M.; Mastrandrea, P.; Matera, K.; Mattson, M. E.; Mazzacane, A.; Mazzanti, P.; McFarland, K. S.; McIntyre, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Mondragon, M. N.; Moon, C. S.; Moore, R.; Morello, M. J.; Morlock, J.; Movilla Fernandez, P.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Neubauer, M. S.; Nielsen, J.; Nodulman, L.; Noh, S. Y.; Norniella, O.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagan Griso, S.; Pagliarone, C.; Palencia, E.; Papadimitriou, V.; Paramonov, A. A.; Patrick, J.; Pauletta, G.; Paus, C.; Pellett, D. E.; Penzo, A.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Prokoshin, F.; Pranko, A.; Ptohos, F.; Punzi, G.; Rahaman, A.; Ramakrishnan, V.; Ranjan, N.; Redondo, I.; Renton, P.; Rescigno, M.; Riddick, T.; Rimondi, F.; Ristori, L.; Robson, A.; Rodrigo, T.; Rodriguez, T.; Rogers, E.; Rolli, S.; Roser, R.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Safonov, A.

    2012-05-01

    We present the results of a search for dark matter production in the monojet signature. We analyze a sample of Tevatron pp? collisions at ?s=1.96 TeV corresponding to an integrated luminosity of 6.7 fb? recorded by the CDF II detector. In events with large missing transverse energy and one energetic jet, we find good agreement between the standard model prediction and the observed data. We set 90% confidence level upper limits on the dark matter production rate. The limits are translated into bounds on nucleon-dark matter scattering rates which are competitive with current direct detection bounds on spin-independent interaction below a dark matter candidate mass of 5 GeV/c, and on spin-dependent interactions up to masses of 200 GeV/c.

  7. 2001 FEMP Customer Survey Report (Appendices) | Department of Energy

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

    Appendices) 2001 FEMP Customer Survey Report (Appendices) Appendix A: Survey Instrument Appendix B: Detailed Responses Appendix C: Adoption and Diffusion of Innovations Appendices (561.75 KB) More Documents & Publications 2001 FEMP Customer Survey Report (Summary Report) 2001 FEMP Customer Survey Report (Main Report

  8. Commercial Grade Dedication Survey and Training | Department of Energy

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

    Survey and Training Commercial Grade Dedication Survey and Training This survey was conducted to obtain input from EM contractors on processes used to perform Commercial Grade Item (CGI) dedication. The intended use of this information is to form the basis for providing a recommendation to EM for a standard process for CGI dedication. Commercial Grade Dedication Survey and Training (1.17 MB) More Documents & Publications Commercial Grade Dedication Survey and Training EM Commercial Grade

  9. An organizational survey of the Pittsburgh Energy Technology Center

    SciTech Connect (OSTI)

    Stock, D.A.; Shurberg, D.A.; Haber, S.B.

    1991-09-01

    An Organizational Survey (OS) was administrated at the Pittsburgh Energy Technology Center (PETC) that queried employees on the subjects of organizational culture, various aspects of communications, employee commitment, work group cohesion, coordination of work, environmental, safety, and health concerns, hazardous nature of work, safety and overall job satisfaction. The purpose of the OS is to measure in a quantitative and objective way the notion of culture''; that is, the values attitudes, and beliefs of the individuals working within the organization. In addition, through the OS, a broad sample of individuals can be reached that would probably not be interviewed or observed during the course of a typical assessment. The OS also provides a descriptive profile of the organization at one point in time that can then be compared to a profile taken at a different point in time to assess changes in the culture of the organization.

  10. An organizational survey of the Pittsburgh Energy Technology Center

    SciTech Connect (OSTI)

    Stock, D.A.; Shurberg, D.A.; Haber, S.B.

    1991-09-01

    An Organizational Survey (OS) was administrated at the Pittsburgh Energy Technology Center (PETC) that queried employees on the subjects of organizational culture, various aspects of communications, employee commitment, work group cohesion, coordination of work, environmental, safety, and health concerns, hazardous nature of work, safety and overall job satisfaction. The purpose of the OS is to measure in a quantitative and objective way the notion of ``culture``; that is, the values attitudes, and beliefs of the individuals working within the organization. In addition, through the OS, a broad sample of individuals can be reached that would probably not be interviewed or observed during the course of a typical assessment. The OS also provides a descriptive profile of the organization at one point in time that can then be compared to a profile taken at a different point in time to assess changes in the culture of the organization.

  11. Light's Darkness

    ScienceCinema (OSTI)

    Padgett, Miles [University of Glasgow, Glasgow, Scotland

    2010-01-08

    Optical vortices and orbital angular momentum are currently topical subjects in the optics literature. Although seemingly esoteric, they are, in fact, the generic state of light and arise whenever three or more plane waves interfere. To be observed by eye the light must be monochromatic. Laser speckle is one such example, where the optical energy circulates around each black spot, giving a local orbital angular momentum. This talk with report three on-going studies. First, when considering a volume of interfering waves, the laser specs map out threads of complete darkness embedded in the light. Do these threads form loops? Links? Or even knots? Second, when looking through a rapidly spinning window, the image of the world on the other side is rotated: true or false? Finally, the entanglement of orbital angular momentum states means measuring how the angular position of one photons sets the angular momentum of another: is this an angular version of the EPR (Einstein, Podolsky, and Rosen) paradox?

  12. Converting the organic fraction of solid waste from the city of Abu Dhabi to valuable products via dark fermentation – Economic and energy assessment

    SciTech Connect (OSTI)

    Bonk, Fabian Bastidas-Oyanedel, Juan-Rodrigo Schmidt, Jens Ejbye

    2015-06-15

    Graphical abstract: Display Omitted - Highlights: • The cost and energy demand for dark fermentation using OFMSW were established. • Dark fermentation using OFMSW can produce a carbon source for bioprocesses of about 330 USD/t{sub COD}. • A maximum purification cost of VFAs from dark fermentation using OFMSW was established to 15 USD/m{sup 3}. • Replacing fossil fuel based products by dark fermentation will probably lead to net energy savings. - Abstract: Landfilling the organic fraction of municipal solid waste (OFMSW) leads to greenhouse gas emissions and loss of valuable resources. Sustainable and cost efficient solutions need to be developed to solve this problem. This study evaluates the feasibility of using dark fermentation (DF) to convert the OFMSW to volatile fatty acids (VFAs), fertilizer and H{sub 2}. The VFAs in the DF effluent can be used directly as substrate for subsequent bioprocesses or purified from the effluent for industrial use. DF of the OFMSW in Abu Dhabi will be economically sustainable once VFA purification can be accomplished on large scale for less than 15 USD/m{sup 3}{sub effluent}. With a VFA minimum selling price of 330 USD/t{sub COD}, DF provides a competitive carbon source to sugar. Furthermore, DF is likely to use less energy than conventional processes that produce VFAs, fertilizer and H{sub 2}. This makes DF of OFMSW a promising waste treatment technology and biorefinery platform.

  13. The direct detection of boosted dark matter at high energies and PeV events at IceCube

    SciTech Connect (OSTI)

    Bhattacharya, A.; Gandhi, R.; Gupta, A.

    2015-03-13

    We study the possibility of detecting dark matter directly via a small but energetic component that is allowed within present-day constraints. Drawing closely upon the fact that neutral current neutrino nucleon interactions are indistinguishable from DM-nucleon interactions at low energies, we extend this feature to high energies for a small, non-thermal but highly energetic population of DM particle χ, created via the decay of a significantly more massive and long-lived non-thermal relic Φ, which forms the bulk of DM. If χ interacts with nucleons, its cross-section, like the neutrino-nucleus coherent cross-section, can rise sharply with energy leading to deep inelastic scattering, similar to neutral current neutrino-nucleon interactions at high energies. Thus, its direct detection may be possible via cascades in very large neutrino detectors. As a specific example, we apply this notion to the recently reported three ultra-high energy PeV cascade events clustered around 1 – 2 PeV at IceCube (IC). We discuss the features which may help discriminate this scenario from one in which only astrophysical neutrinos constitute the event sample in detectors like IC.

  14. The direct detection of boosted dark matter at high energies and PeV events at IceCube

    SciTech Connect (OSTI)

    Bhattacharya, A.; Gandhi, R.; Gupta, A.

    2015-03-13

    We study the possibility of detecting dark matter directly via a small but energetic component that is allowed within present-day constraints. Drawing closely upon the fact that neutral current neutrino nucleon interactions are indistinguishable from DM-nucleon interactions at low energies, we extend this feature to high energies for a small, non-thermal but highly energetic population of DM particle χ, created via the decay of a significantly more massive and long-lived non-thermal relic ϕ, which forms the bulk of DM. If χ interacts with nucleons, its cross-section, like the neutrino-nucleus coherent cross-section, can rise sharply with energy leading to deep inelastic scattering, similar to neutral current neutrino-nucleon interactions at high energies. Thus, its direct detection may be possible via cascades in very large neutrino detectors. As a specific example, we apply this notion to the recently reported three ultra-high energy PeV cascade events clustered around 1−2 PeV at IceCube (IC). We discuss the features which may help discriminate this scenario from one in which only astrophysical neutrinos constitute the event sample in detectors like IC.

  15. The direct detection of boosted dark matter at high energies and PeV events at IceCube

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bhattacharya, A.; Gandhi, R.; Gupta, A.

    2015-03-13

    We study the possibility of detecting dark matter directly via a small but energetic component that is allowed within present-day constraints. Drawing closely upon the fact that neutral current neutrino nucleon interactions are indistinguishable from DM-nucleon interactions at low energies, we extend this feature to high energies for a small, non-thermal but highly energetic population of DM particle χ, created via the decay of a significantly more massive and long-lived non-thermal relic Φ, which forms the bulk of DM. If χ interacts with nucleons, its cross-section, like the neutrino-nucleus coherent cross-section, can rise sharply with energy leading to deep inelasticmore » scattering, similar to neutral current neutrino-nucleon interactions at high energies. Thus, its direct detection may be possible via cascades in very large neutrino detectors. As a specific example, we apply this notion to the recently reported three ultra-high energy PeV cascade events clustered around 1 – 2 PeV at IceCube (IC). We discuss the features which may help discriminate this scenario from one in which only astrophysical neutrinos constitute the event sample in detectors like IC.« less

  16. Category:2-M Probe Survey | Open Energy Information

    Open Energy Info (EERE)

    2-M Probe Survey Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Geothermalpower.jpg Looking for the 2-M Probe Survey page? For detailed information on 2-M Probe...

  17. Aeromagnetic Survey At Coso Geothermal Area (1977) | Open Energy...

    Open Energy Info (EERE)

    Home Exploration Activity: Aeromagnetic Survey At Coso Geothermal Area (1977) Exploration Activity Details Location Coso Geothermal Area Exploration Technique...

  18. Survey of the Economics of Hydrogen Technologies | Department of Energy

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

    Survey of the Economics of Hydrogen Technologies Survey of the Economics of Hydrogen Technologies Survey of the Economics of Hydrogen Technologies 27079.pdf (1.02 MB) More Documents & Publications Proceedings of the 2000 U.S. DOE Hydrogen Program Review Costs of Storing and Transporting Hydrogen FTA - SunLine Transit Agency - Final Report

  19. 2001 FEMP Customer Survey Report (Main Report) | Department of Energy

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

    Main Report) 2001 FEMP Customer Survey Report (Main Report) This summary presents the key findings and recommendations from the 2001 FEMP customer survey. The key findings presented in this summary are a condensed presentation of the more detailed findings presented in each of the chapters. Study Report (2.32 MB) More Documents & Publications 2001 FEMP Customer Survey Report (Summary

  20. Radiation tolerance survey of selected silicon photomultipliers to high energy neutron irradiation

    SciTech Connect (OSTI)

    Barbosa, Fernando J.; McKisson, John E.; Qiang, Yi; Steinberger, William; Xi, Wenze; Zorn, Carl J.

    2012-11-01

    A key feature of silicon photomultipliers (SiPMs) that can hinder their wider use in medium and high energy physics applications is their relatively high sensitivity to high energy background radiation, with particular regard to high energy neutrons. Dosages of 1010 neq/cm2 can damage them severely. In this study, some standard versions along with some new formulations are irradiated with a high intensity 241AmBe source up to a total dose of 5 109 neq/cm2. Key parameters monitored include dark noise, photon detection efficiency (PDE), gain, and voltage breakdown. Only dark noise was found to change significantly for this range of dosage. Analysis of the data indicates that within each vendor's product line, the change in dark noise is very similar as a function of increasing dose. At present, the best strategy for alleviating the effects of radiation damage is to cool the devices to minimize the effects of increased dark noise with accumulated dose.

  1. Commercial Buildings Energy Consumption Survey (CBECS) - Data - U.S. Energy

    Gasoline and Diesel Fuel Update (EIA)

    Information Administration (EIA) What is an RSE? The estimates in the Commercial Buildings Energy Consumption Survey (CBECS) are based on data reported by representatives of a statistically-designed subset of the entire commercial building population in the United States, or a "sample." Consequently, the estimates differ from the true population values. However, the sample design permits us to estimate the sampling error in each value. It is important to understand: CBECS estimates

  2. User-needs study for the 1992 Commercial Buildings Energy Consumption Survey

    SciTech Connect (OSTI)

    Not Available

    1992-09-01

    The Commercial Buildings Energy Consumption Survey (CBECS) that is conducted by the Energy Information Administration (EIA) is the primary source of energy data for commercial buildings in the United States. The survey began in 1979 and has subsequently been conducted in 1983, 1986, and 1989. The next survey will cover energy consumption during the year 1992. The building characteristic data will be collected between August 1992 and early December 1992. Requests for energy consumption data are mailed to the energy suppliers in January 1993, with data due by March 1993. Before each survey is sent into the field, the data users` needs are thoroughly assessed. The purpose of this report is to document the findings of that user-needs assessment for the 1992 survey.

  3. EOSO ENERGY MEASUREMENTS GROUP THE REMOT SENSIN EG&G SURVEY REPORT...

    Office of Legacy Management (LM)

    Oe. 1-G lZLq n EOSO ENERGY MEASUREMENTS GROUP THE REMOT SENSIN EG&G SURVEY REPORT LABORATO EP-F-002 Of THE UNITED STATES DECEMBER 1981 DEPARTMENT OF ENERGY AN AERIAL RADIOLOGICAL ...

  4. Conduct an In-Plant Pumping System Survey | Department of Energy

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

    Conduct an In-Plant Pumping System Survey Conduct an In-Plant Pumping System Survey This tip sheet outlines key steps in an effective in-plant pumping system survey. PUMPING SYSTEMS TIP SHEET #1 Conduct an In-Plant Pumping System Survey (September 2005) (215.78 KB) More Documents & Publications Test for Pumping System Efficiency Match Pumps to System Requirements Select an Energy-Efficient Centrifugal Pump

  5. Is the misalignment of the Local Group velocity and the dipole generated by the 2MASS Redshift Survey typical in {lambda} cold dark matter and the halo model of galaxies?

    SciTech Connect (OSTI)

    Erdogdu, Pirin; Lahav, Ofer

    2009-08-15

    We predict the acceleration of the Local Group generated by the 2MASS Redshift Survey within the framework of {lambda} cold dark matter and the halo model of galaxies. We show that as the galaxy fluctuations derived from the halo model have more power on small scales compared with the mass fluctuations, the misalignment angle between the CMB velocity vector and the 2MASS Redshift Survey dipole is in reasonable agreement with the observed 21 deg. This statistical analysis suggests that it is not necessary to invoke a hypothetical nearby galaxy or a distant cluster to explain this misalignment.

  6. Energy conservation by hyperfiltration: food industry background literature survey

    SciTech Connect (OSTI)

    Not Available

    1980-04-15

    The application of hyperfiltration to selected food product streams and food processing wastewaters for energy conservation was examined. This literature survey had led to the following conclusions: no research has been conducted in the food industry using membranes with hot process streams due to the temperature limitation (< 40/sup 0/C) of the typically studied cellulose acetate membranes; based on the bench-scale research reviewed, concentration of fruit and vegetable juices with membranes appears to be technically feasible; pretreatment and product recovery research was conducted with membranes on citrus peel oil, potato processing and brine wastewaters and wheys. The experiments demonstrated that these applications are feasible; many of the problems that have been identified with membranes are associated with either the suspended solids or the high osmotic pressure and viscosity of many foods; research using dynamic membranes has been conducted with various effluents, at temperatures to approx. 100/sup 0/C, at pressures to 1200 psi and with suspended solids to approx. 2%; and, the dynamic membrane is being prototype tested by NASA for high temperature processing of shower water. The literature review substantiates potential for dynamic membrane on porous stainless tubes to process a number of hot process and effluent streams in the food processing industry. Hot water for recycle and product concentrations are major areas with potential for economic application. The two plants involved in the first phase of the project should be reviewed to identify potential energy conservation applications. As many as possible of the conservation applications should be tested during the screening phase at each site. The most promising applications at each site should be evaluated more intensively to establish engineering estimates of the economics of this technology for the canned fruit and vegetable segment of the food industry.

  7. Energy consumption series: Development of the 1991 Manufacturing Energy Consumption Survey

    SciTech Connect (OSTI)

    Not Available

    1992-05-18

    The implementation and results of the proceedings concerning the Energy Information Administration assessment of the Manufacturing Energy Consumption Survey (MECS) are documented in this report. The text and Appendices C, D, and E summarize the background of the MECS data system, the events that led to the MECS redesign, the major issues address during the review process, and the eventual 1991 MECS design that resulted. For many readers, the most useful part of the report may be Appendices A and B, which contain overall summaries of the users' groups and the industrial roundtables. These appendices capture the rationale for additional data needs as provided by the users. Also, they are a rich source of information on how manufacturers deal with energy use day-to-day, how they have addressed the need for energy efficiency improvement in the past, and the opportunities and problems associated with future efforts to improve efficiency. (VC)

  8. Energy consumption series: Development of the 1991 Manufacturing Energy Consumption Survey

    SciTech Connect (OSTI)

    Not Available

    1992-05-18

    The implementation and results of the proceedings concerning the Energy Information Administration assessment of the Manufacturing Energy Consumption Survey (MECS) are documented in this report. The text and Appendices C, D, and E summarize the background of the MECS data system, the events that led to the MECS redesign, the major issues address during the review process, and the eventual 1991 MECS design that resulted. For many readers, the most useful part of the report may be Appendices A and B, which contain overall summaries of the users` groups and the industrial roundtables. These appendices capture the rationale for additional data needs as provided by the users. Also, they are a rich source of information on how manufacturers deal with energy use day-to-day, how they have addressed the need for energy efficiency improvement in the past, and the opportunities and problems associated with future efforts to improve efficiency. (VC)

  9. ENERGY MEASUREMENTS GROUP EG&G SURVEY REPORT NE-F-003

    Office of Legacy Management (LM)

    * * * * * * * * * ~n~EGc.G ENERGY MEASUREMENTS GROUP EG&G SURVEY REPORT NE-F-003 FEBRUARY 1983 THE REMOTE SENSING LABORATORY OF THE UNITED STATES DEPARTMENT OF ENERGY AN AERIAL RADIOLOGICAL SURVEY OF AN AREA SURROUNDING THE FORMER MIDDLESEX SAMPLING PLANT IN MIDDLESEX, NEW JERSEY DATE OF SURVEY: MAY 1978 DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of

  10. 2001 FEMP Customer Survey Report (Summary Report) | Department of Energy

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

    Summary Report) 2001 FEMP Customer Survey Report (Summary Report) The study was targeted to collect information from the average FEMP customer. As a result, the respondents in this survey represent 27 different federal agencies and a group of private contractors who have contracts with one or more federal agencies Summary Report (523.75 KB) More Documents & Publications 2001 FEMP Customer Survey Report (Main

  11. OSTIblog Articles in the dark energy Topic | OSTI, US Dept of...

    Office of Scientific and Technical Information (OSTI)

    in OSTI's monthly Science Showcase on OSTI's Home Page. This quiet, unassuming man crafts prolific papers on popular science topics of interest to the Department of Energy (DOE). ...

  12. Refraction Survey At Rye Patch Area (Laney, 2005) | Open Energy...

    Open Energy Info (EERE)

    Activity Details Location Rye Patch Area Exploration Technique Refraction Survey Activity Date Usefulness useful DOE-funding Unknown Notes Seismic Imaging, Majer, Gritto and Daley....

  13. Reflection Survey At Coso Geothermal Area (1989) | Open Energy...

    Open Energy Info (EERE)

    1989) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Reflection Survey At Coso Geothermal Area (1989) Exploration Activity Details Location Coso...

  14. Refraction Survey At Coso Geothermal Area (1989) | Open Energy...

    Open Energy Info (EERE)

    Area (1989) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Refraction Survey At Coso Geothermal Area (1989) Exploration Activity Details...

  15. Category:Ground Gravity Survey | Open Energy Information

    Open Energy Info (EERE)

    Apps Datasets Community Login | Sign Up Search Category Edit History Category:Ground Gravity Survey Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home...

  16. Ground Gravity Survey At Coso Geothermal Area (1990) | Open Energy...

    Open Energy Info (EERE)

    (1990) Exploration Activity Details Location Coso Geothermal Area Exploration Technique Ground Gravity Survey Activity Date 1990 Usefulness not indicated DOE-funding Unknown...

  17. Reflection Survey At The Needles Area (DOE GTP) | Open Energy...

    Open Energy Info (EERE)

    The Needles Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Reflection Survey At The Needles Area (DOE GTP) Exploration Activity...

  18. Aeromagnetic Survey At Maui Area (DOE GTP) | Open Energy Information

    Open Energy Info (EERE)

    Maui Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Aeromagnetic Survey At Maui Area (DOE GTP) Exploration Activity Details...

  19. Static Temperature Survey At Maui Area (DOE GTP) | Open Energy...

    Open Energy Info (EERE)

    Maui Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Static Temperature Survey At Maui Area (DOE GTP) Exploration Activity Details...

  20. Reflection Survey At Jemez Pueblo Area (DOE GTP) | Open Energy...

    Open Energy Info (EERE)

    Jemez Pueblo Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Reflection Survey At Jemez Pueblo Area (DOE GTP) Exploration Activity...

  1. Static Temperature Survey At Wister Area (DOE GTP) | Open Energy...

    Open Energy Info (EERE)

    Wister Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Static Temperature Survey At Wister Area (DOE GTP) Exploration Activity...

  2. Aeromagnetic Survey At Glass Buttes Area (DOE GTP) | Open Energy...

    Open Energy Info (EERE)

    Glass Buttes Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Aeromagnetic Survey At Glass Buttes Area (DOE GTP) Exploration...

  3. Reflection Survey At Wister Area (DOE GTP) | Open Energy Information

    Open Energy Info (EERE)

    Wister Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Reflection Survey At Wister Area (DOE GTP) Exploration Activity Details...

  4. DC Resistivity Survey (Schlumberger Array) | Open Energy Information

    Open Energy Info (EERE)

    of the electrodes during the survey. References (Keller, 1966) "Dipole Method for Deep Resistivity Studies" (Sharma, 1997) "Environmental and Engineering Geophysics"...

  5. DC Resistivity Survey (Pole-Dipole Array) | Open Energy Information

    Open Energy Info (EERE)

    Techniques Potential Pitfalls See Direct-Current Resistivity Survey References (Smith, 1986) "Application of the pole-dipole resistivity technique to the detection of...

  6. United States Geological Survey, LSC | Open Energy Information

    Open Energy Info (EERE)

    Testing Facilities Name United States Geological Survey, LSC Address Leetown Science Center, Conte Anadromous Fish Laboratory, 1 Migratory Way Place Turners Falls,...

  7. United States Geological Survey, HIF | Open Energy Information

    Open Energy Info (EERE)

    HIF Jump to: navigation, search Hydro | Hydrodynamic Testing Facilities Name United States Geological Survey, HIF Address Building 2101 Stennis Space Center Place Mississippi Zip...

  8. Aeromagnetic Survey At Kawaihae Area (Thomas, 1986) | Open Energy...

    Open Energy Info (EERE)

    Kawaihae Area Exploration Technique Aeromagnetic Survey Activity Date Usefulness useful DOE-funding Unknown Notes The aeromagnetic data noted above refer to a low-level...

  9. Telluric Survey At Raft River Geothermal Area (1978) | Open Energy...

    Open Energy Info (EERE)

    Raft River Geothermal Area (1978) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Telluric Survey At Raft River Geothermal Area (1978)...

  10. Colorado State Land Board Land Survey Requirements | Open Energy...

    Open Energy Info (EERE)

    Colorado State Land Board Land Survey Requirements Jump to: navigation, search OpenEI Reference LibraryAdd to library PermittingRegulatory Guidance - GuideHandbook: Colorado...

  11. Computing the Dark Universe | Argonne Leadership Computing Facility

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

    They will provide access to studying different aspects of the 'Dark Universe', dominated by the mysterious duo of dark energy and dark matter. The project will bring together two ...

  12. Interacting dark sector with transversal interaction

    SciTech Connect (OSTI)

    Chimento, Luis P.; Richarte, Martín G.

    2015-03-26

    We investigate the interacting dark sector composed of dark matter, dark energy, and dark radiation for a spatially flat Friedmann-Robertson-Walker (FRW) background by introducing a three-dimensional internal space spanned by the interaction vector Q and solve the source equation for a linear transversal interaction. Then, we explore a realistic model with dark matter coupled to a scalar field plus a decoupled radiation term, analyze the amount of dark energy in the radiation era and find that our model is consistent with the recent measurements of cosmic microwave background anisotropy coming from Planck along with the future constraints achievable by CMBPol experiment.

  13. Department of Energy Earned Value Management Survey Results | Department of

    Energy Savers [EERE]

    Department of Energy Achieves Goal of 200 Energy Savings Assessments Department of Energy Achieves Goal of 200 Energy Savings Assessments March 2, 2007 - 10:28am Addthis Over 50 Trillion Btus of Natural Gas Savings Found AUSTIN, TX - The U.S. Department of Energy (DOE) Assistant Secretary for Energy Efficiency and Renewable Andy Karsner today announced the completion of Energy Savings Assessments (ESAs) at 200 of the largest industrial facilities in the nation, identifying opportunities to

  14. 2001 Residential Energy Consumption Survey Answers to Frequently...

    U.S. Energy Information Administration (EIA) Indexed Site

    ... RoperASW is a well respected survey research firm. You will return your completed forms to ... The government may bring a civil action to prohibit reporting violations which may result ...

  15. Telluric Survey At Clear Lake Area (Skokan, 1993) | Open Energy...

    Open Energy Info (EERE)

    through use of a controlled source transient electromagnetic survey (Keller and Jacobson, 1983 ). A grounded-wire source of 1.1 km in length was energized with a current of...

  16. Surveys

    Broader source: Energy.gov [DOE]

    Surveys can be a useful way to gauge the opinions of your readers and learn more about your website's audiences, but you'll often need approval from the Office of Management and Budget (OMB) to run...

  17. Environmental Survey preliminary report, Morgantown Energy Technology Center, Morgantown, West Virginia

    SciTech Connect (OSTI)

    Not Available

    1988-06-01

    This report presents the preliminary findings from the first phase of the Environmental Survey of the US Department of Energy (DOE) Morgantown Energy Technology Center (METC) conducted November 30 through December 4, 1987. In addition, the preliminary findings of the Laramie Project Office (LPO) Survey, which was conducted as part of the METC Survey on January 25 through 29, 1988, are presented in Appendices E and F. The Survey is being conducted by an interdisciplinary team of environmental specialists, led and managed by the Office of Environment, Safety and Health's Office of Environmental Audit. Individual team components are outside experts being supplied by a private contractor. The objective of the Survey is to identify environmental problems and areas of environmental risk associated with METC. The Survey covers all environmental media and all areas of environmental regulation. It is being performed in accordance with the DOE Environmental Survey Manual. The on-site phase of the Survey involves the review of existing site environmental data, observations of the operations carried on at METC, and interviews with site personnel. The Survey team developed a Sampling and Analysis Plan to assist in further assessing certain environmental problems identified during its on-site activities at METC. The Sampling and Analysis Plan will be executed by the Oak Ridge National Laboratory (ORNL). When completed, the results will be incorporated into the METC Environmental Survey Interim Report. The Interim Report will reflect the final determinations of the Survey METC. 60 refs., 28 figs., 43 tabs.

  18. Commercial Buildings Energy Consumption Survey 2003 - Detailed Tables

    Reports and Publications (EIA)

    2008-01-01

    The tables contain information about energy consumption and expenditures in U.S. commercial buildings and information about energy-related characteristics of these buildings.

  19. Trends in energy use in commercial buildings -- Sixteen years of EIA's commercial buildings energy consumption survey

    SciTech Connect (OSTI)

    Davis, J.; Swenson, A.

    1998-07-01

    The Commercial Buildings Energy Consumption Survey (CBECS) collects basic statistical information on energy consumption and energy-related characteristics of commercial buildings in the US. The first CBECS was conducted in 1979 and the most recent was completed in 1995. Over that period, the number of commercial bindings and total amount of floorspace increased, total consumption remained flat, and total energy intensity declined. By 1995, there were 4.6 million commercial buildings and 58.8 billion square feet of floorspace. The buildings consumed a total of 5.3 quadrillion Btu (site energy), with a total intensity of 90.5 thousand Btu per square foot per year. Electricity consumption exceeded natural gas consumption (2.6 quadrillion and 1.9 quadrillion Btu, respectively). In 1995, the two major users of energy were space heating (1.7 quadrillion Btu) and lighting (1.2 quadrillion Btu). Over the period 1979 to 1995, natural gas intensity declined from 71.4 thousand to 51.0 thousand Btu per square foot per year. Electricity intensity did not show a similar decline (44.2 thousand Btu per square foot in 1979 and 45.7 thousand Btu per square foot in 1995). Two types of commercial buildings, office buildings and mercantile and service buildings, were the largest consumers of energy in 1995 (2.0 quadrillion Btu, 38% of total consumption). Three building types, health care, food service, and food sales, had significantly higher energy intensities. Buildings constructed since 1970 accounted for half of total consumption and a majority (59%) of total electricity consumption.

  20. Environmental Survey preliminary report, National Institute for Petroleum and Energy Research, Bartlesville, Oklahoma

    SciTech Connect (OSTI)

    Not Available

    1989-01-01

    This report presents the preliminary findings of the first phase of the Environmental Survey of the US Department of Energy's (DOE) National Institute for Petroleum and Energy Research (NIPER), conducted February 29 through March 4, 1988. The Survey is being conducted by an interdisciplinary team of environmental specialists, led and managed by the Office of Environment, Safety and Health's Office of Environmental Audit. Team members are being provided by private contractors. The objective of the Survey is to identify environmental problems and areas of environmental risk associated with NIPER. The Survey covers all environmental media and all areas of environmental regulation. It is being performed in accordance with the DOE Environmental Survey Manual. The on-site phase of the Survey involves the review of existing site environmental data, observations of the operations carried on at NIPER and interviews with site personnel. 35 refs., 8 figs., 15 tabs.

  1. Mapping the Heavens: Probing Cosmology with Large Surveys

    ScienceCinema (OSTI)

    Frieman, Joshua [Fermilab

    2009-09-01

    This talk will provide an overview of recent and on-going sky surveys, focusing on their implications for cosmology. I will place particular emphasis on the Sloan Digital Sky Survey, the most ambitious mapping of the Universe yet undertaken, showing a virtual fly-through of the survey that reveals the large-scale structure of the galaxy distribution. Recent measurements of this large-scale structure, in combination with observations of the cosmic microwave background, have provided independent evidence for a Universe dominated by dark matter and dark energy as well as insights into how galaxies and larger-scale structures formed. Future planned surveys will build on these foundations to probe the history of the cosmic expansion--and thereby the dark energy--with greater precision.

  2. Cool Trends on Campus: A Survey of Thermal Energy Storage Use...

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

    A survey was conducted to develop a database documenting and quantifying the use of Thermal Energy Storage (TES) in campus applications. cooltrendsoncampus.pdf (97.88 KB) More ...

  3. Idaho Geological Survey and University of Idaho Explore for Geothermal Energy

    Broader source: Energy.gov [DOE]

    The University of Idaho's Idaho Geological Survey recently drilled new wells in southeastern Idaho to provide the most accurate assessment of high-temperature geothermal energy potential in the region.

  4. Prospects for Future Very High-Energy Gamma-Ray Sky Survey: Impact...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Prospects for Future Very High-Energy Gamma-Ray Sky Survey: Impact of Secondary Gamma Rays Citation Details In-Document Search Title: Prospects for Future Very ...

  5. Nonresidential-building energy-consumption survey, 1979. Final report, Part II and Part III

    SciTech Connect (OSTI)

    Not Available

    1981-06-01

    The Utility Survey component of the Nonresidential Building Energy Consumption Survey was designed to provide data on the quantity and costs of energy consumed during 1979 by each building represented in the Building Survey data. To this end, 13,386 consumption and cost reporting forms were mailed to 1509 companies/organizations/agencies who supplied some type of energy to the 6222 buildings represented in the data from the earlier Building Survey. Part II, Section 2 discusses the step-by-step process of building the computer and manual files that were needed in order to conduct the Utility Survey. How the files were actually used in order to implement, control, and manage the Utility Survey was also discussed. Section 3 discusses the reporting forms and the accompanying instructional material used to collect data from the energy suppliers and Section 4 discusses the various operations for implementing the data collection task. The proessing of the data is described in Section 5 and the method of keeping the data confidential is described in Section 6. Part III, Section 7 presents several analyses of the costs associated with the Interim Nonresidential Building Energy Consumption Survey. Tables included reflect costs incurred through April 25, 1981. Administrative correspondence, record sheets, and explanatory notes are included in appendices. (MCW)

  6. 1999 Commercial Buildings Energy Consumption Survey Detailed Tables

    U.S. Energy Information Administration (EIA) Indexed Site

    Consumption and Expenditures Tables Table C1. Total Energy Consumption by Major Fuel ............................................... 124 Table C2. Total Energy Expenditures by Major Fuel................................................ 130 Table C3. Consumption for Sum of Major Fuels ...................................................... 135 Table C4. Expenditures for Sum of Major Fuels....................................................... 140 Table C5. Consumption and Gross Energy Intensity by

  7. Manufacturing Energy Consumption Survey (MECS) - Analysis & Projections -

    Gasoline and Diesel Fuel Update (EIA)

    Association of Electrical and Medical Imaging Equipment Manufacturers Manufacturing Solutions for Energy Efficiency in Buildings Patrick Hughes Policy Director, High Performance Buildings National Electrical Manufacturers Association The Association of Electrical and Medical Imaging Equipment Manufacturers What is NEMA? The Association of Electrical Equipment and Medical Imaging Manufacturers Which policies encourage energy efficiency in buildings? Energy Savings Performance Contracts Tax

  8. All Other Editions Are Obsolete U.S. DEPARTMENT OF ENERGY SAFEGUARDS AND SECURITY SURVEY REPORT

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

    4.1 (05-94) All Other Editions Are Obsolete U.S. DEPARTMENT OF ENERGY SAFEGUARDS AND SECURITY SURVEY REPORT OMB Control No. 1910-1800 1. Survey Type: 3. Facility Name: 4. A. Facility Code: B. RIS Code: 5. Survey Date(s): 8. Previous Survey Date(s): 6. Findings: 9. Unresolved Findings: 7. Composite Rating: 10. Previous Rating: 11. Ratings: Rate Each Item: S = SATISFACTORY M = MARGINAL U = UNSATISFACTORY DNA = DOES NOT APPLY A) PROGRAM MANAGEMENT Program Management and Administration Program

  9. STEP Non-Participant Survey Report | Department of Energy

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

    THE NATURAL RESOURCES AGENCY EDMUND G. BROWN, JR., Governor CALIFORNIA ENERGY COMMISSION 1516 Ninth Street, MS 14 Sacramento, California 95814 Main website: www.energy.ca.gov January 12, 2011 United States Department of Energy (DOE) Via e-mail: expartecommunications@hq.doe.gov RE: Ex parte communication of the California Energy Commission Docket No. EERE-2008-BT-STD-0005 To Whom It May Concern, On January 6, 2011, Mike Leaon, Harinder Singh, Ken Rider, and Dennis Beck of the California Energy

  10. Environmental Survey preliminary report, Laboratory for Energy-Related Health Research, Davis, California

    SciTech Connect (OSTI)

    Not Available

    1988-03-01

    This report presents the preliminary findings from the first phase of the Survey of the United States Department of Energy (DOE) Laboratory for Energy-Related Health Research (LEHR) at the University of California, Davis (UC Davis), conducted November 16 through 20, 1987. The Survey is being conducted by an interdisciplinary team of environmental specialists, led and managed by the Office of Environment, Safety and Health's Office of Environmental Audit. Individual team components are being supplied by a private contractor. The objective of the Survey is to identify environmental problems and areas of environmental risk associated with the LEHR. The Survey covers all environmental media and all areas of environmental regulation, and is being performed in accordance with the DOE Environmental Survey Manual. This phase of the Survey involves the review of existing site environmental data, observations of the operations at the LEHR and interviews with site personnel. The Survey team developed a Sampling and Analysis Plan to assist in further assessing certain of the environmental problems identified during its on-site activities. The Sampling and Analysis Plan will be executed by a DOE National Laboratory or a support contractor. When completed, the results will be incorporated into the Environmental Survey Interim Report for the LEHR at UC Davis. The Interim Report will reflect the final determinations of the LEHR Survey. 75 refs., 26 figs., 23 tabs.

  11. Stealth Dark Matter: Dark scalar baryons through the Higgs portal

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Appelquist, T.; Brower, R. C.; Buchoff, M. I.; Fleming, G. T.; Jin, X. -Y.; Kiskis, J.; Kribs, G. D.; Neil, E. T.; Osborn, J. C.; Rebbi, C.; et al

    2015-10-23

    We present a new model of "Stealth Dark Matter": a composite baryonic scalar of an SU(ND) strongly coupled theory with even ND ≥ 4. All mass scales are technically natural, and dark matter stability is automatic without imposing an additional discrete or global symmetry. Constituent fermions transform in vectorlike representations of the electroweak group that permit both electroweak-breaking and electroweak-preserving mass terms. This gives a tunable coupling of stealth dark matter to the Higgs boson independent of the dark matter mass itself. We specialize to SU(4), and investigate the constraints on the model from dark meson decay, electroweak precision measurements,more » basic collider limits, and spin-independent direct detection scattering through Higgs exchange. We exploit our earlier lattice simulations that determined the composite spectrum as well as the effective Higgs coupling of stealth dark matter in order to place bounds from direct detection, excluding constituent fermions with dominantly electroweak-breaking masses. A lower bound on the dark baryon mass mB ≳ 300 GeV is obtained from the indirect requirement that the lightest dark meson not be observable at LEP II. Furthermore, we briefly survey some intriguing properties of stealth dark matter that are worthy of future study, including collider studies of dark meson production and decay; indirect detection signals from annihilation; relic abundance estimates for both symmetric and asymmetric mechanisms; and direct detection through electromagnetic polarizability, a detailed study of which will appear in a companion paper.« less

  12. Stealth Dark Matter: Dark scalar baryons through the Higgs portal

    SciTech Connect (OSTI)

    Appelquist, T.; Brower, R. C.; Buchoff, M. I.; Fleming, G. T.; Jin, X. -Y.; Kiskis, J.; Kribs, G. D.; Neil, E. T.; Osborn, J. C.; Rebbi, C.; Rinaldi, E.; Schaich, D.; Schroeder, C.; Syritsyn, S.; Vranas, P.; Weinberg, E.; Witzel, O.

    2015-10-23

    We present a new model of "Stealth Dark Matter": a composite baryonic scalar of an SU(ND) strongly coupled theory with even ND ≥ 4. All mass scales are technically natural, and dark matter stability is automatic without imposing an additional discrete or global symmetry. Constituent fermions transform in vectorlike representations of the electroweak group that permit both electroweak-breaking and electroweak-preserving mass terms. This gives a tunable coupling of stealth dark matter to the Higgs boson independent of the dark matter mass itself. We specialize to SU(4), and investigate the constraints on the model from dark meson decay, electroweak precision measurements, basic collider limits, and spin-independent direct detection scattering through Higgs exchange. We exploit our earlier lattice simulations that determined the composite spectrum as well as the effective Higgs coupling of stealth dark matter in order to place bounds from direct detection, excluding constituent fermions with dominantly electroweak-breaking masses. A lower bound on the dark baryon mass mB ≳ 300 GeV is obtained from the indirect requirement that the lightest dark meson not be observable at LEP II. Furthermore, we briefly survey some intriguing properties of stealth dark matter that are worthy of future study, including collider studies of dark meson production and decay; indirect detection signals from annihilation; relic abundance estimates for both symmetric and asymmetric mechanisms; and direct detection through electromagnetic polarizability, a detailed study of which will appear in a companion paper.

  13. Energy Information Administration (EIA)- CBECS Survey Background and

    Gasoline and Diesel Fuel Update (EIA)

    Technical Information Estimation of Standard Errors Sampling error is the difference between the survey estimate and the true population value due to the use of a random sample to estimate the population. This difference arises because a random subset, rather than the whole population, is observed. The typical magnitude of the sampling error is measured by the standard error of the estimate. The standard error is the root-mean-square difference between the estimate based on a particular

  14. DoE Early Career Research Program: Final Report: Model-Independent Dark-Matter Searches at the ATLAS Experiment and Applications of Many-core Computing to High Energy Physics

    SciTech Connect (OSTI)

    Farbin, Amir

    2015-07-15

    This is the final report of for DoE Early Career Research Program Grant Titled "Model-Independent Dark-Matter Searches at the ATLAS Experiment and Applications of Many-core Computing to High Energy Physics".

  15. Commercial Buildings Energy Consumption Survey (CBECS) - Analysis &

    Gasoline and Diesel Fuel Update (EIA)

    Projections - U.S. Energy Information Administration (EIA) 2012 CBECS Preliminary Results What is a commercial building? The CBECS includes buildings greater than 1,000 square feet that devote more than half of their floorspace to activity that is neither residential, manufacturing, industrial, nor agricultural. When will energy consumption estimates be available? Energy consumption and expenditures data will be available beginning in spring 2015. CBECS data collection is currently in its

  16. A survey of the electrical energy requirement of hotels in Hong Kong

    SciTech Connect (OSTI)

    Chow, W.K.; Chan, K.T. . Dept. of Building Services Engineering)

    1993-01-01

    Electrical energy consumption in commercial buildings accounts for about 50 percent of the total electricity produced in Hong Kong. Investigation of the electrical energy requirement in these buildings is essential to energy conservation. With it, norms of energy use for the buildings in use can be deduced and can be used to establish energy management programs. This article reports on a pioneer investigation on the electrical energy use of hotels in Hong Kong. A survey on the actual consumption in 20 hotels has been conducted, and results are presented. Significance of the norms and the various end-use components of the total electrical energy requirement are discussed.

  17. Alternative Fuels - A New Field For Mine Surveying | Open Energy...

    Open Energy Info (EERE)

    more importance. As far as Germany is concerned, geothermal energy and coal bedmine methane are considered as mineral resources according to the German mining law. This demands...

  18. A Framework to Survey the Energy Efficiency of Installed Motor Systems

    SciTech Connect (OSTI)

    Rao, Prakash; Hasanbeigi, Ali; McKane, Aimee

    2013-08-01

    While motors are ubiquitous throughout the globe, there is insufficient data to properly assess their level of energy efficiency across regional boundaries. Furthermore, many of the existing data sets focus on motor efficiency and neglect the connected drive and system. Without a comprehensive survey of the installed motor system base, a baseline energy efficiency of a country or region’s motor systems cannot be developed. The lack of data impedes government agencies, utilities, manufacturers, distributers, and energy managers when identifying where to invest resources to capture potential energy savings, creating programs aimed at reducing electrical energy consumption, or quantifying the impacts of such programs. This paper will outline a data collection framework for use when conducting a survey under a variety of execution models to characterize motor system energy efficiency within a country or region. The framework is intended to standardize the data collected ensuring consistency across independently conducted surveys. Consistency allows for the surveys to be leveraged against each other enabling comparisons to motor system energy efficiencies from other regions. In creating the framework, an analysis of various motor driven systems, including compressed air, pumping, and fan systems, was conducted and relevant parameters characterizing the efficiency of these systems were identified. A database using the framework will enable policymakers and industry to better assess the improvement potential of their installed motor system base particularly with respect to other regions, assisting in efforts to promote improvements to the energy efficiency of motor driven systems.

  19. Dark Secrets: What Science Tells Us About the Hidden Universe (LBNL Science at the Theater)

    ScienceCinema (OSTI)

    Permutter, Saul; Schlegel, David; Leauthaud, Alexie

    2011-04-28

    No mystery is bigger than dark energy - the elusive force that makes up three-quarters of the Universe and is causing it to expand at an accelerating rate. KTVU Channel 2 health and science editor John Fowler will moderate a panel of Lawrence Berkeley National Laboratory scientists who use phenomena such as exploding stars and gravitational lenses to explore the dark cosmos. Saul Perlmutter heads the Supernova Cosmology Project, which pioneered the use of precise observations of exploding stars to study the expansion of the Universe. His international team was one of two groups who independently discovered the amazing phenomenon known as dark energy, and he led a collaboration that designed a satellite to study the nature of this dark force. He is an astrophysicist at Berkeley Lab and a professor of physics at UC Berkeley. David Schlegel is a Berkeley Lab astrophysicist and the principal investigator of Baryon Oscillation Spectroscopic Survey (BOSS), the largest of four night-sky surveys being conducted in the third phase of the Sloan Digital Sky Survey, known as SDSS-III. BOSS will generate a 3-D map of two million galaxies and quasars, using a specially built instrument outfitted with 1,000 optical fibers and mounted on the SDSS telescope in New Mexico. Alexie Leauthaud is Chamberlain Fellow at Berkeley Lab. Her work probes dark matter in the Universe using a technique called gravitational lensing. When gravity from a massive object such as a cluster of galaxies warps space around it, this can distort our view of the light from an even more distant object. The scale and direction of this distortion allows astronomers to directly measure the properties of both dark matter and dark energy.

  20. Dark matter annihilation or unresolved astrophysical sources...

    Office of Scientific and Technical Information (OSTI)

    Citation Details In-Document Search Title: Dark matter annihilation or unresolved ... cosmic gamma-ray background (CGB) is a longstanding mystery in high-energy astrophysics. ...

  1. User-needs study for the 1993 residential energy consumption survey

    SciTech Connect (OSTI)

    Not Available

    1993-09-24

    During 1992, the Energy Information Administration (EIA) conducted a user-needs study for the 1993 Residential Energy Consumption Survey (RECS). Every 3 years, the RECS collects information on energy consumption and expenditures for various classes of households and residential buildings. The RECS is the only source of such information within EIA, and one of only a few sources of such information anywhere. EIA sent letters to more than 750 persons, received responses from 56, and held 15 meetings with users. Written responses were also solicited by notices published in the April 14, 1992 Federal Register and in several energy-related publications. To ensure that the 1993 RECS meets current information needs, EIA made a specific effort to get input from policy makers and persons needing data for forecasting efforts. These particular needs relate mainly to development of the National Energy Modeling System and new energy legislation being considered at the time of the user needs survey.

  2. Dark D-brane cosmology

    SciTech Connect (OSTI)

    Koivisto, Tomi; Wills, Danielle; Zavala, Ivonne E-mail: d.e.wills@durham.ac.uk

    2014-06-01

    Disformally coupled cosmologies arise from Dirac-Born-Infeld actions in Type II string theories, when matter resides on a moving hidden sector D-brane. Since such matter interacts only very weakly with the standard model particles, this scenario can provide a natural origin for the dark sector of the universe with a clear geometrical interpretation: dark energy is identified with the scalar field associated to the D-brane's position as it moves in the internal space, acting as quintessence, while dark matter is identified with the matter living on the D-brane, which can be modelled by a perfect fluid. The coupling functions are determined by the (warped) extra-dimensional geometry, and are thus constrained by the theory. The resulting cosmologies are studied using both dynamical system analysis and numerics. From the dynamical system point of view, one free parameter controls the cosmological dynamics, given by the ratio of the warp factor and the potential energy scales. The disformal coupling allows for new scaling solutions that can describe accelerating cosmologies alleviating the coincidence problem of dark energy. In addition, this scenario may ameliorate the fine-tuning problem of dark energy, whose small value may be attained dynamically, without requiring the mass of the dark energy field to be unnaturally low.

  3. Residential Energy Consumption Survey (RECS) - Analysis & Projections -

    Gasoline and Diesel Fuel Update (EIA)

    U.S. Energy Information Administration (EIA) All Reports & Publications Search By: Go Pick a date range: From: To: Go graph of electricity sales by sector, as explained in the article text Total U.S. electricity sales projected to grow slowly as electricity intensity declines June 15, 2016 Industrial and electric power sectors drive projected growth in U.S. natural gas use May 26, 2016 Declining energy prices lower the cost of living May 3, 2016 All 70 related articles › Residential

  4. Fermilab | Newsroom | Press Releases | August 18, 2014: Dark...

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

    Interactive to see what the Dark Energy Camera sees. thumb This image of the NGC 1398 galaxy was taken with the Dark Energy Camera. This galaxy lives in the Fornax cluster,...

  5. DOE/EIA-0318/1 Nonresidential Buildings Energy Consumption Survey:

    U.S. Energy Information Administration (EIA) Indexed Site

    318/1 Nonresidential Buildings Energy Consumption Survey: 1979 Consumption and Expenditures D! Part I: Natural Gas and Electricity March 1983 Energy Information Administration Washington, D.C. 1111? This publication is available from the Superintendent of Documents, U.S. Government Printing Office |GPO). Make check or money order payable to the Superintendent of Documents. You may send your order to the U.S. Government Printing Office or the National Energy Information Center. GPO prices are

  6. CHP Industrial Bottoming and Topping Cycle with Energy Information Administration Survey Data

    U.S. Energy Information Administration (EIA) Indexed Site

    CHP Industrial Bottoming and Topping Cycle with Energy Information Administration Survey Data Paul Otis, August 14, 2015 Independent Statistics & Analysis www.eia.gov U.S. Energy Information Administration Washington, DC 20585 This paper is released to encourage discussion and critical comment. The analysis and conclusions expressed here are those of the authors and not necessarily those of the U.S. Energy Information Administration. DISCUSSION PAPER SERIES August 2015 Paul Otis | U.S.

  7. Dark Matter

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

    Dark Matter Scientists are using the underground of the Waste Isolation Pilot Plant to try to solve the universe's major missing mass problem. He is enjoying his search They are searching for the presence of particles that may have mass but hardly interact with other matter. Based on observations of the relationships between mass and gravity and the speed of the stars and other cosmological systems, scientists believe that more than 90 percent of the universe's mass is "missing." A

  8. Survey and Analysis of Weather Data for Building Energy Simulations

    SciTech Connect (OSTI)

    Bhandari, Mahabir S; Shrestha, Som S; New, Joshua Ryan

    2012-01-01

    In recent years, calibrated energy modeling of residential and commercial buildings has gained importance in a retrofit-dominated market. Accurate weather data plays an important role in this calibration process and projected energy savings. It would be ideal to measure weather data at the building location to capture relevant microclimate variation but this is generally considered cost-prohibitive. There are data sources publicly available with high temporal sampling rates but at relatively poor geospatial sampling locations. To overcome this limitation, there are a growing number of service providers that claim to provide real time and historical weather data for 20-35 km2 grid across the globe. Unfortunately, there is limited documentation from 3rd-party sources attesting to the accuracy of this data. This paper compares provided weather characteristics with data collected from a weather station inaccessible to the service providers. Monthly average dry bulb temperature; relative humidity; direct, diffuse and horizontal solar radiation; and wind speed are statistically compared. Moreover, we ascertain the relative contributions of each weather variable and its impact on building loads. Annual simulations are calculated for three different building types, including a closely monitored and automated energy efficient research building. The comparison shows that the difference for an individual variable can be as high as 90%. In addition, annual building energy consumption can vary by 7% while monthly building loads can vary by 40% as a function of the provided location s weather data.

  9. Velocities as a probe of dark sector interactions

    SciTech Connect (OSTI)

    Koyama, Kazuya; Maartens, Roy; Song, Yong-Seon E-mail: Roy.Maartens@port.ac.uk

    2009-10-01

    Dark energy in General Relativity is typically non-interacting with other matter. However, it is possible that the dark energy interacts with the dark matter, and in this case, the dark matter can violate the universality of free fall (the weak equivalence principle). We show that some forms of the dark sector interaction do not violate weak equivalence. For those interactions that do violate weak equivalence, there are no available laboratory experiments to probe this violation for dark matter. But cosmology provides a test for violations of the equivalence principle between dark matter and baryons—via a test for consistency of the observed galaxy velocities with the Euler equation.

  10. Dark Matter Annihilation at the Galactic Center

    SciTech Connect (OSTI)

    Linden, Timothy Ryan

    2013-06-01

    Observations by the WMAP and PLANCK satellites have provided extraordinarily accurate observations on the densities of baryonic matter, dark matter, and dark energy in the universe. These observations indicate that our universe is composed of approximately ve times as much dark matter as baryonic matter. However, e orts to detect a particle responsible for the energy density of dark matter have been unsuccessful. Theoretical models have indicated that a leading candidate for the dark matter is the lightest supersymmetric particle, which may be stable due to a conserved R-parity. This dark matter particle would still be capable of interacting with baryons via weak-force interactions in the early universe, a process which was found to naturally explain the observed relic abundance of dark matter today. These residual annihilations can persist, albeit at a much lower rate, in the present universe, providing a detectable signal from dark matter annihilation events which occur throughout the universe. Simulations calculating the distribution of dark matter in our galaxy almost universally predict the galactic center of the Milky Way Galaxy (GC) to provide the brightest signal from dark matter annihilation due to its relative proximity and large simulated dark matter density. Recent advances in telescope technology have allowed for the rst multiwavelength analysis of the GC, with suitable e ective exposure, angular resolution, and energy resolution in order to detect dark matter particles with properties similar to those predicted by the WIMP miracle. In this work, I describe ongoing e orts which have successfully detected an excess in -ray emission from the region immediately surrounding the GC, which is di cult to describe in terms of standard di use emission predicted in the GC region. While the jury is still out on any dark matter interpretation of this excess, I describe several related observations which may indicate a dark matter origin. Finally, I discuss the

  11. U.S. Energy Information Administration (EIA) - Survey

    Gasoline and Diesel Fuel Update (EIA)

    Analysis & Projections Capital Cost For Electricity Plants see full report previous version Updated Capital Cost Estimates for Utility Scale Electricity Generating Plants Release Date: April 12, 2013 Introduction The current and future projected cost and performance characteristics of new electric generating capacity are a critical input into the development of energy projections and analyses. The construction and operating costs, along with the performance characteristics of new generating

  12. Residential energy consumption survey: consumption and expenditures, April 1982-March 1983. Part 1, national data

    SciTech Connect (OSTI)

    Thompson, W.

    1984-11-01

    This report presents data on the US consumption and expenditures for residential use of natural gas, electricity, fuel oil or kerosene, and liquefied petroleum gas (LPG) from April 1982 through March 1983. Data on the consumption of wood for this period are also presented. The consumption and expenditures data are based on actual household bills, obtained, with the permission of the household. from the companies supplying energy to the household. Data on wood consumption are based on respondent recall of the amount of wood burned during the winter and are subject to memory errors and other reporting errors described in the report. These data come from the 1982 Residential Energy Consumption Survey (RECS), the fifth in a series of comparable surveys beginning in 1978. The 1982 survey is the first survey to include, as part of its sample, a portion of the same households interviewed in the 1980 survey. A separate report is planned to report these longitudinal data. This summary gives the highlights of a comparison of the findings for the 5 years of RECS data. The data cover all types of housing units in the 50 states and the District of Columbia including single-family units, apartments, and mobile homes. For households with indirect energy costs, such as costs that are included in the rent or paid by third parties, the sonsumption and expenditures data are estimated and included in the figures reported here. The average household consumption of natural gas, electricity, fuel oil or kerosene, and LPG dropped in 1982 from the previous year, hitting a 5-year low since the first Residential Energy Consumption Survey (RECS) was conducted in 1978. The average consumption was 103 (+-3) million Btu per household in 1982, down from 114 (+-) million Btu in 1981. The weather was the main contributing factor. 8 figures, 46 tables.

  13. Dark Matter Jets at the LHC (Journal Article) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    These dark matter particles have unique signatures at colliders; instead of missing energy, the dark matter particles produce jets. We propose a new search strategy for such ...

  14. A Search for dark matter in events with one jet and missing transverse energy in $p\\bar{p}$ collisions at $\\sqrt{s} = 1.96$ TeV

    SciTech Connect (OSTI)

    Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J.A.; Arisawa, T.; Artikov, A.; /Dubna, JINR /Texas A-M

    2012-03-01

    We present the results of a search for dark matter production in the monojet signature. We analyze a sample of Tevatron pp collisions at {radical}s = 1.96 TeV corresponding to an integrated luminosity of 6.7 fb{sup -1} recorded by the CDF II detector. In events with large missing transverse energy and one energetic jet, we find good agreement between the standard model prediction and the observed data. We set 90% confidence level upper limits on the dark matter production rate. The limits are translated into bounds on nucleon-dark matter scattering rates which are competitive with current direct detection bounds on spin-independent interaction below a dark matter candidate mass of 5 GeV/c{sup 2}, and on spin-dependent interactions up to masses of 200 GeV/c{sup 2}.

  15. A search for the higgs boson and a search for dark-matter particle with jets and missing transverse energy at collider detector at Fermilab

    SciTech Connect (OSTI)

    Liu, Qiuguang

    2013-05-01

    Finding the standard model Higgs boson and discovering beyond-standard model physics phenomena have been the most important goals for the high-energy physics in the last decades. In this thesis, we present two such searches. First is the search for the low mass standard model Higgs boson produced in association with a vector boson; second is the rst search for a dark-matter candidate (D) produced in association with a top quark (t) in particle colliders. We search in events with energetic jets and large missing transverse energy { a signature characterized by complicated backgrounds { in data collected by the CDF detector with proton-antiproton collisions at p s = 1:96 TeV. We discuss the techniques that have been developed for background modeling, for discriminating signal from background, and for reducing background resulting from detector e ects. In the Higgs search, we report the 95% con dence level upper limits on the pro- duction cross section across masses of 90 to 150 GeV/c2. The expected limits are improved by an average of 14% relative to the previous analysis. The Large Hadron Collider experiments reported a Higgs-like particle with mass of 125 GeV/c2 by study- ing the data collected in year 2011/12. At a Higgs boson mass of 125 GeV/c2, our observed (expected) limit is 3.06 (3.33) times the standard model prediction, corre- sponding to one of the most sensitive searches to date in this nal state. In the dark matter search, we nd the data are consistent with the standard model prediction, thus set 95% con dence level upper limits on the cross section of the process p p ! t + D as a function of the mass of the dark-matter candidate. The xviii upper limits are approximately 0.5 pb for a dark-matter particle with masses in the range of 0 􀀀 150 GeV/c2.

  16. Energy Efficiency and Renewable Energy Network (EREN) customer satisfaction survey, 1997. Final report

    SciTech Connect (OSTI)

    Anderson, A.V.; Henderson, D.P.

    1997-07-01

    the EREN Customer Satisfaction Survey 1997 was designed to follow up the results of the 1995-96 Surveys, enabling comparison to the 1995- 96 baseline, and to provide additional qualitative feedback about EREN. Both the 1995-96 and 1997 Surveys had these objectives: Identify and define actual EREN users; Determine the value or benefits derived from the use of EREN; Determine the kind and quality of services that users want; Determine the users` levels of satisfaction with existing services; Determine users` preferences in both the sources of service and means of delivery; and Establish continuous quality improvement measures. This report presents the methodology used, scope and limitations of the study, description of the survey instrument, and findings regarding demographics, technical capabilities, usage patterns, general use, importance of and satisfaction with resources, and additional information and comments.

  17. Residential energy use and conservation in Venezuela: Results and implications of a household survey in Caracas

    SciTech Connect (OSTI)

    Figueroa, M.J.; Ketoff, A.; Masera, O.

    1992-10-01

    This document presents the final report of a study of residential energy use in Caracas, the capital of Venezuela. It contains the findings of a household energy-use survey held in Caracas in 1988 and examines options for introducing energy conservation measures in the Venezuelan residential sector. Oil exports form the backbone of the Venezuelan economy. Improving energy efficiency in Venezuela will help free domestic oil resources that can be sold to the rest of the world. Energy conservation will also contribute to a faster recovery of the economy by reducing the need for major investments in new energy facilities, allowing the Venezuelan government to direct its financial investments towards other areas of development. Local environmental benefits will constitute an important additional by-product of implementing energy-efficiency policies in Venezuela. Caracas`s residential sector shows great potential for energy conservation. The sector is characterized by high saturation levels of major appliances, inefficiency of appliances available in the market, and by careless patterns of energy use. Household energy use per capita average 6.5 GJ/per year which is higher than most cities in developing countries; most of this energy is used for cooking. Electricity accounts for 41% of all energy use, while LPG and natural gas constitute the remainder. Specific options for inducing energy conservation and energy efficiency in Caracas`s residential sector include energy-pricing policies, fuel switching, particularly from electricity to gas, improving the energy performance of new appliances and customer information. To ensure the accomplishment of an energy-efficiency strategy, a concerted effort by energy users, manufacturers, utility companies, government agencies, and research institutions will be needed.

  18. Dark matter directional detection in non-relativistic effective theories

    SciTech Connect (OSTI)

    Catena, Riccardo

    2015-07-20

    We extend the formalism of dark matter directional detection to arbitrary one-body dark matter-nucleon interactions. The new theoretical framework generalizes the one currently used, which is based on 2 types of dark matter-nucleon interaction only. It includes 14 dark matter-nucleon interaction operators, 8 isotope-dependent nuclear response functions, and the Radon transform of the first 2 moments of the dark matter velocity distribution. We calculate the recoil energy spectra at dark matter directional detectors made of CF{sub 4}, CS{sub 2} and {sup 3}He for the 14 dark matter-nucleon interactions, using nuclear response functions recently obtained through numerical nuclear structure calculations. We highlight the new features of the proposed theoretical framework, and present our results for a spherical dark matter halo and for a stream of dark matter particles. This study lays the foundations for model independent analyses of dark matter directional detection experiments.

  19. Dark Colored Cool Pigments for Materials Exposed to the Sun ...

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

    Building Energy Efficiency Building Energy Efficiency Find More Like This Return to Search Dark Colored Cool Pigments for Materials Exposed to the Sun Lawrence Berkeley National ...

  20. Muon fluxes from dark matter annihilation (Journal Article) ...

    Office of Scientific and Technical Information (OSTI)

    We calculate the muon flux from annihilation of the dark matter in the core of the Sun, in the ... We illustrate how muon energy distribution from dark matter annihilation ...

  1. Results of the 2008/2009 Knowledge and Opinions Surveys Conducted for the U.S. Department of Energy Hydrogen Program

    Fuel Cell Technologies Publication and Product Library (EERE)

    This report presents results of a 2008/2009 survey of hydrogen and fuel cell awareness conducted for the U.S. Department of Energy (DOE). The 2008/2009 survey follows up on a similar DOE survey conduc

  2. Survey of Recipients of WAP Services Assessment of Household Budget and Energy Behaviors Pre to Post Weatherization DOE

    SciTech Connect (OSTI)

    Tonn, Bruce Edward; Rose, Erin M.; Hawkins, Beth A.

    2015-10-01

    This report presents results from the national survey of weatherization recipients. This research was one component of the retrospective and Recovery Act evaluations of the U.S. Department of Energy s Weatherization Assistance Program. Survey respondents were randomly selected from a nationally representative sample of weatherization recipients. The respondents and a comparison group were surveyed just prior to receiving their energy audits and then again approximately 18 months post-weatherization. This report focuses on budget issues faced by WAP households pre- and post-weatherization, whether household energy behaviors changed from pre- to post, the effectiveness of approaches to client energy education, and use and knowledge about thermostats.

  3. The 1992 Pacific Northwest Residential Energy Survey: Phase 1 : Book 1 : Getting Started.

    SciTech Connect (OSTI)

    Applied Management & Planning Group; United States. Bonneville Power Administration. End-Use Research Section.

    1993-08-01

    This Executive Summary outlines the general processes employed in and the major findings from the conduct of Phase I of the Pacific Northwest Residential Energy Survey (PNWRES92-I) during the last quarter of 1992. This study was Bonneville`s third comprehensive residential survey of the region, conducted to provide data on energy usage, conservation awareness and behaviors, and associated consumer characteristics for use in forecasting and planning. The summary is divided into four sections: Background sets the stage with respect to the need for the survey, relates it to previous work, outlines the implementation processes, and summarizes the data products. Profiling the respondents summarizes the survey results under these six categories: Demographics; Housing Units; Room Inventory; Appliance Inventory; Air-Conditioning/Heating; Water-Heating; and Opinion. Reports and cross-tabulations describes the various individual documents. Bonneville Power Plus provides a short description of an Excel-spreadsheet-based software program that contains all of the tabulated material in a format that encourages browsing among the tables and charts, with special feature that they can be copied directly into other Windows-based documents.

  4. Dark matter beams at LBNF

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Coloma, Pilar; Dobrescu, Bogdan A.; Frugiuele, Claudia; Harnik, Roni

    2016-04-08

    High-intensity neutrino beam facilities may produce a beam of light dark matter when protons strike the target. Searches for such a dark matter beam using its scattering in a nearby detector must overcome the large neutrino background. We characterize the spatial and energy distributions of the dark matter and neutrino beams, focusing on their differences to enhance the sensitivity to dark matter. We find that a dark matter beam produced by a Zmore » $$^{'}$$ boson in the GeV mass range is both broader and more energetic than the neutrino beam. The reach for dark matter is maximized for a detector sensitive to hard neutral-current scatterings, placed at a sizable angle off the neutrino beam axis. In the case of the Long-Baseline Neutrino Facility (LBNF), a detector placed at roughly 6 degrees off axis and at a distance of about 200 m from the target would be sensitive to Z$$^{'}$$ couplings as low as 0.05. This search can proceed symbiotically with neutrino measurements. We also show that the MiniBooNE and MicroBooNE detectors, which are on Fermilab’s Booster beamline, happen to be at an optimal angle from the NuMI beam and could perform searches with existing data. As a result, this illustrates potential synergies between LBNF and the short-baseline neutrino program if the detectors are positioned appropriately.« less

  5. Tax and Fiscal Policies for Promotion of Industrial EnergyEfficiency: A Survey of International Experience

    SciTech Connect (OSTI)

    Price, Lynn; Galitsky, Christina; Sinton, Jonathan; Worrell,Ernst; Graus, Wina

    2005-09-15

    The Energy Foundation's China Sustainable Energy Program (CSEP) has undertaken a major project investigating fiscal and tax policy options for stimulating energy efficiency and renewable energy development in China. This report, which is part of the sectoral sub-project studies on energy efficiency in industry, surveys international experience with tax and fiscal policies directed toward increasing investments in energy efficiency in the industrial sector. The report begins with an overview of tax and fiscal policies, including descriptions and evaluations of programs that use energy or energy-related carbon dioxide (CO2) taxes, pollution levies, public benefit charges, grants or subsidies, subsidized audits, loans, tax relief for specific technologies, and tax relief as part of an energy or greenhouse gas (GHG) emission tax or agreement scheme. Following the discussion of these individual policies, the report reviews experience with integrated programs found in two countries as well as with GHG emissions trading programs. The report concludes with a discussion of the best practices related to international experience with tax and fiscal policies to encourage investment in energy efficiency in industry.

  6. Dark Shadows

    SciTech Connect (OSTI)

    Mills, Andrew; Ahlstrom, Mark; Brower, Michael; Ellis, Abraham; George, Ray; Hoff, Tom; Kroposki, Benjamin; Lenox, Carl; Miller, Nicholas; Milligan, Michael; Stein, Joshua; Wan, Yih-huei

    2011-01-10

    The U.S. Department of Energy's National Renewable Energy Laboratory, Sandia National Laboratories, the Solar Electric Power Association, the Utility Wind Integration Group, and the U.S. Department of Energy hosted a day-long public workshop on the variability of photovoltaic (PV) plants. The workshop brought together utilities, PV system developers, power system operators, and several experts to discuss the potential impacts of PV variability and uncertainty on power system operations.

  7. Quintessence with quadratic coupling to dark matter

    SciTech Connect (OSTI)

    Boehmer, Christian G.; Chan, Nyein; Caldera-Cabral, Gabriela; Lazkoz, Ruth; Maartens, Roy

    2010-04-15

    We introduce a new form of coupling between dark energy and dark matter that is quadratic in their energy densities. Then we investigate the background dynamics when dark energy is in the form of exponential quintessence. The three types of quadratic coupling all admit late-time accelerating critical points, but these are not scaling solutions. We also show that two types of coupling allow for a suitable matter era at early times and acceleration at late times, while the third type of coupling does not admit a suitable matter era.

  8. Siting Study Framework and Survey Methodology for Marine and Hydrokinetic Energy Project in Offshore Southeast Florida

    SciTech Connect (OSTI)

    Vinick, Charles; Riccobono, Antonino, MS; Messing, Charles G., Ph.D.; Walker, Brian K., Ph.D.; Reed, John K., Ph.D.

    2012-02-28

    Dehlsen Associates, LLC was awarded a grant by the United States Department of Energy (DOE) Golden Field Office for a project titled 'Siting Study Framework and Survey Methodology for Marine and Hydrokinetic Energy Project in Offshore Southeast Florida,' corresponding to DOE Grant Award Number DE-EE0002655 resulting from DOE funding Opportunity Announcement Number DE-FOA-0000069 for Topic Area 2, and it is referred to herein as 'the project.' The purpose of the project was to enhance the certainty of the survey requirements and regulatory review processes for the purpose of reducing the time, efforts, and costs associated with initial siting efforts of marine and hydrokinetic energy conversion facilities that may be proposed in the Atlantic Ocean offshore Southeast Florida. To secure early input from agencies, protocols were developed for collecting baseline geophysical information and benthic habitat data that can be used by project developers and regulators to make decisions early in the process of determining project location (i.e., the siting process) that avoid or minimize adverse impacts to sensitive marine benthic habitat. It is presumed that such an approach will help facilitate the licensing process for hydrokinetic and other ocean renewable energy projects within the study area and will assist in clarifying the baseline environmental data requirements described in the U.S. Department of the Interior Bureau of Ocean Energy Management, Regulation and Enforcement (formerly Minerals Management Service) final regulations on offshore renewable energy (30 Code of Federal Regulations 285, published April 29, 2009). Because projects generally seek to avoid or minimize impacts to sensitive marine habitats, it was not the intent of this project to investigate areas that did not appear suitable for the siting of ocean renewable energy projects. Rather, a two-tiered approach was designed with the first step consisting of gaining overall insight about seabed conditions

  9. Environmental Survey preliminary report, Department of Energy (DOE) activities at Santa Susana Field Laboratories, Ventura County, California

    SciTech Connect (OSTI)

    Not Available

    1989-02-01

    This report presents the preliminary findings from the first phase of the Environmental Survey of the United States Department of Energy (DOE) activities at the Santa Susana Field Laboratories Site (DOE/SSFL), conducted May 16 through 26, 1988. The Survey is being conducted by an interdisciplinary team of environmental specialists, led and managed by the Office of Environment, Safety and Health's Office of Environmental Audit. Individual participants for the Survey team are being supplied by an private contractor. The objective of the survey is to identify environmental problems and areas of environmental risk associated with DOE activities at SSFL. The Survey covers all environmental media and all areas of environmental regulation. It is being performed in accordance with the DOE Environmental Survey Manual. This phase of the Survey involves the review of existing site environmental data, observations of the operations performed at SSFL, and interviews with site personnel. 90 refs., 17 figs., 28 tabs.

  10. Issue Brief: A Survey of State Policies to Support Utility-Scale and Distributed-Energy Storage (Brochure), NREL (National Renewable Energy Laboratory)

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

    t e c h n i c a l a s s i s ta n c e NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC. NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC. t e c h n i c a l a s s i s ta n c e Issue Brief: A Survey of State Policies to Support Utility-Scale and Distributed-Energy

  11. Preliminary survey and evaluation of nonaquifer thermal energy storage concepts for seasonal storage

    SciTech Connect (OSTI)

    Blahnik, D.E.

    1980-11-01

    Thermal energy storage enables the capture and retention of heat energy (or cold) during one time period for use during another. Seasonal thermal energy storage (STES) involves a period of months between the input and recovery of energy. The purpose of this study was to make a preliminary investigation and evaluation of potential nonaquifer STES systems. Current literature was surveyed to determine the state of the art of thermal energy storage (TES) systems such as hot water pond storage, hot rock storage, cool ice storage, and other more sophisticated concepts which might have potential for future STES programs. The main energy sources for TES principally waste heat, and the main uses of the stored thermal energy, i.e., heating, cooling, and steam generation are described. This report reviews the development of sensible, latent, and thermochemical TES technologies, presents a preliminary evaluation of the TES methods most applicable to seasonal storage uses, outlines preliminary conclusions drawn from the review of current TES literature, and recommends further research based on these conclusions. A bibliography of the nonaquifer STES literature review, and examples of 53 different TES concepts drawn from the literature are provided. (LCL)

  12. Dipolar dark matter with massive bigravity

    SciTech Connect (OSTI)

    Blanchet, Luc; Heisenberg, Lavinia

    2015-12-14

    Massive gravity theories have been developed as viable IR modifications of gravity motivated by dark energy and the problem of the cosmological constant. On the other hand, modified gravity and modified dark matter theories were developed with the aim of solving the problems of standard cold dark matter at galactic scales. Here we propose to adapt the framework of ghost-free massive bigravity theories to reformulate the problem of dark matter at galactic scales. We investigate a promising alternative to dark matter called dipolar dark matter (DDM) in which two different species of dark matter are separately coupled to the two metrics of bigravity and are linked together by an internal vector field. We show that this model successfully reproduces the phenomenology of dark matter at galactic scales (i.e. MOND) as a result of a mechanism of gravitational polarisation. The model is safe in the gravitational sector, but because of the particular couplings of the matter fields and vector field to the metrics, a ghost in the decoupling limit is present in the dark matter sector. However, it might be possible to push the mass of the ghost beyond the strong coupling scale by an appropriate choice of the parameters of the model. Crucial questions to address in future work are the exact mass of the ghost, and the cosmological implications of the model.

  13. Asymmetric dark matter

    SciTech Connect (OSTI)

    Kumar, Jason

    2014-06-24

    We review the theoretical framework underlying models of asymmetric dark matter, describe astrophysical constraints which arise from observations of neutron stars, and discuss the prospects for detecting asymmetric dark matter.

  14. Comparison of the Department of Energy's 2007, 2008, & 2009 Annual Employee Survey Results

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

    the Department of Energy's 2007, 2008, & 2009 Annual Employee Survey Results Item # Personal Work Experiences Year Favorable Neutral Unfavorable DNK/NBJ 2009 87% 7% 6% 0% 2008 86% 8% 6% 0% 1 The people I work with cooperate to get the job done. 2007 78% 13% 9% 0% 2009 68% 17% 15% 0% 2008 66% 17% 17% 0% 2 I am given a real opportunity to improve my skills in my organization. 2007 57% 25% 19% 0% 2009 76% 13% 11% 0% 2008 72% 14% 14% 0% 3 My work gives me a feeling of personal accomplishment.

  15. Redshift-space distortions in massive neutrino and evolving dark...

    Office of Scientific and Technical Information (OSTI)

    Redshift-space distortions in massive neutrino and evolving dark energy cosmologies ... This content will become publicly available on March 16, 2017 Title: Redshift-space ...

  16. Neutrino Coherent Scattering Rates at Direct Dark Matter Detectors...

    Office of Scientific and Technical Information (OSTI)

    Neutrino Coherent Scattering Rates at Direct Dark Matter Detectors Citation Details ... Visit OSTI to utilize additional information resources in energy science and technology. A ...

  17. Offshore Wind Energy Permitting: A Survey of U.S. Project Developers

    SciTech Connect (OSTI)

    Van Cleve, Frances B.; Copping, Andrea E.

    2010-11-30

    The U.S. Department of Energy (DOE) has adopted a goal to generate 20% of the nation’s electricity from wind power by 2030. Achieving this “20% Wind Scenario” in 2030 requires acceleration of the current rate of wind project development. Offshore wind resources contribute substantially to the nation’s wind resource, yet to date no offshore wind turbines have been installed in the U.S. Progress developing offshore wind projects has been slowed by technological challenges, uncertainties about impacts to the marine environment, siting and permitting challenges, and viewshed concerns. To address challenges associated with siting and permitting, Pacific Northwest National Laboratory (PNNL) surveyed offshore wind project developers about siting and project development processes, their experience with the environmental permitting process, and the role of coastal and marine spatial planning (CMSP) in development of the offshore wind industry. Based on the responses to survey questions, we identify several priority recommendations to support offshore wind development. Recommendations also include considerations for developing supporting industries in the U.S. and how to use Coastal and Marine Spatial Planning (CMSP) to appropriately consider ocean energy among existing ocean uses. In this report, we summarize findings, discuss the implications, and suggest actions to improve the permitting and siting process.

  18. Survey Consumption

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

    purchase diaries from a subset of respondents composing a Household Transportation Panel and is reported separately. Residential Energy Consumption Survey: Consumption and...

  19. radiological. survey

    National Nuclear Security Administration (NNSA)

    7%2A en NNSA to Conduct Aerial Radiological Surveys Over San Francisco, Pacifica, Berkeley, And Oakland, CA Areas http:nnsa.energy.govmediaroompressreleasesamsca

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

    SciTech Connect (OSTI)

    Abercrombie, Daniel

    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.

  1. A possible explanation of low energy γ-ray excess from galactic centre and Fermi bubble by a Dark Matter model with two real scalars

    SciTech Connect (OSTI)

    Modak, Kamakshya Prasad; Majumdar, Debasish

    2015-03-09

    We promote the idea of multi-component Dark Matter (DM) to explain results from both direct and indirect detection experiments. In these models as contribution of each DM candidate to relic abundance is summed up to meet WMAP/Planck measurements of Ω{sub DM}, these candidates have larger annihilation cross-sections compared to the single-component DM models. We illustrate this fact by introducing an extra scalar to the popular single real scalar DM model. We also present detailed calculations for the vacuum stability bounds, perturbative unitarity and triviality constraints on this model. As direct detection experimental results still show some conflict, we kept our options open, discussing different scenarios with different DM mass zones. In the framework of our model we make an interesting observation: the existing direct detection experiments like CDMS II, CoGeNT, CRESST II, XENON 100 or LUX together with the observation of excess low energy γ-ray from galactic centre and Fermi bubble by Fermi Gamma-ray Space Telescope (FGST) already have the capability to distinguish between different DM halo profiles.

  2. Ground Gravity Survey At Hot Pot Area (DOE GTP) | Open Energy...

    Open Energy Info (EERE)

    Ground Gravity Survey At Hot Pot Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Hot Pot Area (DOE GTP)...

  3. Ground Gravity Survey At Fort Bliss Area (DOE GTP) | Open Energy...

    Open Energy Info (EERE)

    Ground Gravity Survey At Fort Bliss Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Fort Bliss Area (DOE...

  4. Ground Gravity Survey At New River Area (DOE GTP) | Open Energy...

    Open Energy Info (EERE)

    Ground Gravity Survey At New River Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At New River Area (DOE...

  5. Ground Gravity Survey At Glass Buttes Area (DOE GTP) | Open Energy...

    Open Energy Info (EERE)

    Ground Gravity Survey At Glass Buttes Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Glass Buttes Area...

  6. The darkness of spin-0 dark radiation

    SciTech Connect (OSTI)

    Marsh, M.C. David

    2015-01-01

    We show that the scattering of a general spin-0 sector of dark radiation off the pre-recombination thermal plasma results in undetectably small spectral distortions of the Cosmic Microwave Background.

  7. Dark Forces and Light Dark Matter

    SciTech Connect (OSTI)

    Hooper, Dan; Weiner, Neal; Xue, Wei

    2012-09-01

    We consider a simple class of models in which the dark matter, X, is coupled to a new gauge boson, phi, with a relatively low mass (m_phi \\sim 100 MeV-3 GeV). Neither the dark matter nor the new gauge boson have tree-level couplings to the Standard Model. The dark matter in this model annihilates to phi pairs, and for a coupling of g_X \\sim 0.06 (m_X/10 GeV)^1/2 yields a thermal relic abundance consistent with the cosmological density of dark matter. The phi's produced in such annihilations decay through a small degree of kinetic mixing with the photon to combinations of Standard Model leptons and mesons. For dark matter with a mass of \\sim10 GeV, the shape of the resulting gamma-ray spectrum provides a good fit to that observed from the Galactic Center, and can also provide the very hard electron spectrum required to account for the observed synchrotron emission from the Milky Way's radio filaments. For kinetic mixing near the level naively expected from loop-suppressed operators (epsilon \\sim 10^{-4}), the dark matter is predicted to scatter elastically with protons with a cross section consistent with that required to accommodate the signals reported by DAMA/LIBRA, CoGeNT and CRESST-II.

  8. Neutrinos and dark matter

    SciTech Connect (OSTI)

    Ibarra, Alejandro

    2015-07-15

    Neutrinos could be key particles to unravel the nature of the dark matter of the Universe. On the one hand, sterile neutrinos in minimal extensions of the Standard Model are excellent dark matter candidates, producing potentially observable signals in the form of a line in the X-ray sky. On the other hand, the annihilation or the decay of dark matter particles produces, in many plausible dark matter scenarios, a neutrino flux that could be detected at neutrino telescopes, thus providing non-gravitational evidence for dark matter. More conservatively, the non-observation of a significant excess in the neutrino fluxes with respect to the expected astrophysical backgrounds can be used to constrain dark matter properties, such as the self-annihilation cross section, the scattering cross section with nucleons and the lifetime.

  9. Systematic Effects in Type-1a Supernovae Surveys from Host Galaxy Spectra

    Office of Scientific and Technical Information (OSTI)

    (Technical Report) | SciTech Connect Systematic Effects in Type-1a Supernovae Surveys from Host Galaxy Spectra Citation Details In-Document Search Title: Systematic Effects in Type-1a Supernovae Surveys from Host Galaxy Spectra The physical relation between the properties of Type Ia supernovae and their host galaxies is investigated. Such supernovae are used to constrain the properties of dark energy, making it crucial to understand their physical properties and to check for systematic

  10. The C-4 Dark Matter Experiment

    SciTech Connect (OSTI)

    Bonicalzi, Ricco; Collar, J. I.; Colaresi, J.; Fast, James E.; Fields, N.; Fuller, Erin S.; Hai, M.; Hossbach, Todd W.; Kos, Marek S.; Orrell, John L.; Overman, Cory T.; Reid, Douglas J.; VanDevender, Brent A.; Wiseman, Clinton G.; Yocum, K. M.

    2013-06-01

    Abstract We describe the experimental design of C-4, an expansion of the CoGeNT dark matter search to four identical detectors each approximately three times the mass of the p-type point contact (PPC) germanium diode presently taking data at the Soudan Underground Laboratory. Expected reductions of radioactive backgrounds and energy threshold are discussed, including an estimate of the additional sensitivity to low-mass dark matter candidates to be obtained with this search.

  11. STEP Participant Survey Report

    Broader source: Energy.gov [DOE]

    STEP Participant Survey Report, from the Tool Kit Framework: Small Town University Energy Program (STEP).

  12. Results of the 2008/2009 Knowledge and Opinions Surveys conducted for the U.S. Department of Energy Hydrogen Program

    Broader source: Energy.gov [DOE]

    This report presents results of a 2008/2009 survey of hydrogen and fuel cell awareness conducted for the US Department of Energy (DOE).

  13. Gravity survey of Dixie Valley, west-central Nevada | Open Energy...

    Open Energy Info (EERE)

    to library Report: Gravity survey of Dixie Valley, west-central Nevada Author Donald H. Schaefer Published US Geological Survey, 1983 Report Number 82-111 DOI Not Provided...

  14. Ratcheting Up The Search for Dark Matter

    SciTech Connect (OSTI)

    McDermott, Samuel Dylan

    2014-01-01

    The last several years have included remarkable advances in two of the primary areas of fundamental particle physics: the search for dark matter and the discovery of the Higgs boson. This dissertation will highlight some contributions made on the forefront of these exciting fields. Although the circumstantial evidence supporting the dark matter hypothesis is now almost undeniably significant, indisputable direct proof is still lacking. As the direct searches for dark matter continue, we can maximize our prospects of discovery by using theoretical techniques complementary to the observational searches to rule out additional, otherwise accessible parameter space. In this dissertation, I report bounds on a wide range of dark matter theories. The models considered here cover the spectrum from the canonical case of self-conjugate dark matter with weak-scale interactions, to electrically charged dark matter, to non-annihilating, non-fermionic dark matter. These bounds are obtained from considerations of astrophysical and cosmological data, including, respectively: diffuse gamma ray photon observations; structure formation considerations, along with an explication of the novel local dark matter structure due to galactic astrophysics; and the existence of old pulsars in dark-matter-rich environments. I also consider the prospects for a model of neutrino dark matter which has been motivated by a wide set of seemingly contradictory experimental results. In addition, I include a study that provides the tools to begin solving the speculative ``inverse'' problem of extracting dark matter properties solely from hypothetical nuclear energy spectra, which we may face if dark matter is discovered with multiple direct detection experiments. In contrast to the null searches for dark matter, we have the example of the recent discovery of the Higgs boson. The Higgs boson is the first fundamental scalar particle ever observed, and precision measurements of the production and decay of

  15. Comment on ''Interacting holographic dark energy model and generalized second law of thermodynamics in a non-flat universe{sup ,} by M.R. Setare (JCAP 01 (2007) 023)

    SciTech Connect (OSTI)

    Karami, K.

    2010-01-01

    Author of ref. 1, M.R. Setare (JCAP 01 (2007) 023), by redefining the event horizon measured from the sphere of the horizon as the system's IR cut-off for an interacting holographic dark energy model in a non-flat universe, showed that the generalized second law of thermodynamics is satisfied for the special range of the deceleration parameter. His paper includes an erroneous calculation of the entropy of the cold dark matter. Also there are some missing terms and some misprints in the equations of his paper. Here we present that his conclusion is not true and the generalized second law is violated for the present time independently of the deceleration parameter.

  16. Proposed mechanism to represent the suppression of dark current density by four orders with low energy light ion (H{sup ?}) implantation in quaternary alloy-capped InAs/GaAs quantum dot infrared photodetectors

    SciTech Connect (OSTI)

    Mandal, A.; Ghadi, H.; Mathur, K.L.; Basu, A.; Subrahmanyam, N.B.V.; Singh, P.; Chakrabarti, S.

    2013-08-01

    Graphical abstract: - Abstract: Here we propose a carrier transport mechanism for low energy H{sup ?} ions implanted InAs/GaAs quantum dot infrared photodetectors supportive of the experimental results obtained. Dark current density suppression of up to four orders was observed in the implanted quantum dot infrared photodetectors, which further demonstrates that they are effectively operational. We concentrated on determining how defect-related material and structural changes attributed to implantation helped in dark current density reduction for InAs/GaAs quantum dot infrared photodetectors. This is the first study to report the electrical carrier transport mechanism of H{sup ?} ion-implanted InAs/GaAs quantum dot infrared photodetectors.

  17. Identifying dark matter interactions in monojet searches

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Agrawal, Prateek; Rentala, Vikram

    2014-05-22

    We study the discrimination of quark-initiated jets from gluon-initiated jets in monojet searches for dark matter using the technique of averaged jet energy profiles. We demonstrate our results in the context of effective field theories of dark matter interactions with quarks and gluons, but our methods apply more generally to a wide class of models. Different effective theories of dark matter and the standard model backgrounds each have a characteristic quark/gluon fraction for the leading jet. When used in conjunction with the traditional cut-and-count monojet search, the jet energy profile can be used to set stronger bounds on contact interactionsmore » of dark matter. In the event of a discovery of a monojet excess at the 14 TeV LHC, contact interactions between dark matter with quarks or with gluons can be differentiated at the 95% confidence level. For a given rate at the LHC, signal predictions at direct detection experiments for different dark matter interactions can span five orders of magnitude. Lastly, the ability to identify these interactions allows us to make a tighter connection between LHC searches and direct detection experiments.« less

  18. Identifying dark matter interactions in monojet searches

    SciTech Connect (OSTI)

    Agrawal, Prateek; Rentala, Vikram

    2014-05-22

    We study the discrimination of quark-initiated jets from gluon-initiated jets in monojet searches for dark matter using the technique of averaged jet energy profiles. We demonstrate our results in the context of effective field theories of dark matter interactions with quarks and gluons, but our methods apply more generally to a wide class of models. Different effective theories of dark matter and the standard model backgrounds each have a characteristic quark/gluon fraction for the leading jet. When used in conjunction with the traditional cut-and-count monojet search, the jet energy profile can be used to set stronger bounds on contact interactions of dark matter. In the event of a discovery of a monojet excess at the 14 TeV LHC, contact interactions between dark matter with quarks or with gluons can be differentiated at the 95% confidence level. For a given rate at the LHC, signal predictions at direct detection experiments for different dark matter interactions can span five orders of magnitude. Lastly, the ability to identify these interactions allows us to make a tighter connection between LHC searches and direct detection experiments.

  19. Distance Probes of Dark Energy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kim, A. G.; Padmanabhan, N.; Aldering, G.; Allen, S. W.; Baltay, C.; Cahn, R. N.; D' Andrea, C. B.; Dalal, N.; Dawson, K. S.; Denney, K. D.; et al

    2015-03-15

    We present the results from the Distances subgroup of the Cosmic Frontier Community Planning Study (Snowmass 2013). This document summarizes the current state of the field as well as future prospects and challenges. In addition to the established probes using Type Ia supernovae and baryon acoustic oscillations, we also consider prospective methods based on clusters, active galactic nuclei, gravitational wave sirens and strong lensing time delays.

  20. Survey of Laser Markets Relevant to Inertial Fusion Energy Drivers, information for National Research Council

    SciTech Connect (OSTI)

    Bayramian, A J; Deri, R J; Erlandson, A C

    2011-02-24

    Development of a new technology for commercial application can be significantly accelerated by leveraging related technologies used in other markets. Synergies across multiple application domains attract research and development (R and D) talent - widening the innovation pipeline - and increases the market demand in common components and subsystems to provide performance improvements and cost reductions. For these reasons, driver development plans for inertial fusion energy (IFE) should consider the non-fusion technology base that can be lveraged for application to IFE. At this time, two laser driver technologies are being proposed for IFE: solid-state lasers (SSLs) and KrF gas (excimer) lasers. This document provides a brief survey of organizations actively engaged in these technologies. This is intended to facilitate comparison of the opportunities for leveraging the larger technical community for IFE laser driver development. They have included tables that summarize the commercial organizations selling solid-state and KrF lasers, and a brief summary of organizations actively engaged in R and D on these technologies.

  1. Reflection Survey At Fish Lake Valley Area (DOE GTP) | Open Energy...

    Open Energy Info (EERE)

    Fish Lake Valley Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Reflection Survey At Fish Lake Valley Area (DOE GTP) Exploration...

  2. Ground radon survey of a geothermal area in Hawaii | Open Energy...

    Open Energy Info (EERE)

    on the lower east riftof Kilauea volcano, were measured by alpha particle sensitive cellulose nitrate films. The survey successfully defined an area of thermal significance...

  3. Ground Gravity Survey At Maui Area (DOE GTP) | Open Energy Information

    Open Energy Info (EERE)

    Maui Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Maui Area (DOE GTP) Exploration Activity Details...

  4. Reflection Survey At Soda Lake Area (DOE GTP) | Open Energy Informatio...

    Open Energy Info (EERE)

    Soda Lake Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Reflection Survey At Soda Lake Area (DOE GTP) Exploration Activity...

  5. Reflection Survey At Rye Patch Area (DOE GTP, 2011) | Open Energy...

    Open Energy Info (EERE)

    DOE GTP, 2011) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Reflection Survey At Rye Patch Area (DOE GTP, 2011) Exploration Activity Details...

  6. Reflection Survey At Hot Pot Area (DOE GTP) | Open Energy Information

    Open Energy Info (EERE)

    Hot Pot Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Reflection Survey At Hot Pot Area (DOE GTP) Exploration Activity Details...

  7. Refraction Survey At New River Area (DOE GTP) | Open Energy Informatio...

    Open Energy Info (EERE)

    New River Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Refraction Survey At New River Area (DOE GTP) Exploration Activity...

  8. Reflection Survey At New River Area (DOE GTP) | Open Energy Informatio...

    Open Energy Info (EERE)

    New River Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Reflection Survey At New River Area (DOE GTP) Exploration Activity...

  9. Static Temperature Survey At Hot Pot Area (DOE GTP) | Open Energy...

    Open Energy Info (EERE)

    Hot Pot Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Static Temperature Survey At Hot Pot Area (DOE GTP) Exploration Activity...

  10. 2-M Probe Survey At Coso Geothermal Area (2007) | Open Energy...

    Open Energy Info (EERE)

    Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: 2-M Probe Survey At Coso Geothermal Area (2007) Exploration Activity Details Location Coso...

  11. Project and Survey Staff (HC-50.1) | Department of Energy

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

    The Project and Survey Staff (HC-50.1) report to the Office of Human Capital Strategy, ... the Department to define and design Human Capital Management (HCM) implementation ...

  12. Ghost dark matter

    SciTech Connect (OSTI)

    Furukawa, Tomonori; Yokoyama, Shuichiro; Ichiki, Kiyotomo; Sugiyama, Naoshi; Mukohyama, Shinji E-mail: shu@a.phys.nagoya-u.ac.jp E-mail: naoshi@a.phys.nagoya-u.ac.jp

    2010-05-01

    We revisit ghost dark matter, the possibility that ghost condensation may serve as an alternative to dark matter. In particular, we investigate the Friedmann-Robertson-Walker (FRW) background evolution and the large-scale structure (LSS) in the ΛGDM universe, i.e. a late-time universe dominated by a cosmological constant and ghost dark matter. The FRW background of the ΛGDM universe is indistinguishable from that of the standard ΛCDM universe if M∼>1eV, where M is the scale of spontaneous Lorentz breaking. From the LSS we find a stronger bound: M∼>10eV. For smaller M, ghost dark matter would have non-negligible sound speed after the matter-radiation equality, and thus the matter power spectrum would significantly differ from observation. These bounds are compatible with the phenomenological upper bound M∼<100GeV known in the literature.

  13. Results of the 2008/2009 Knowledge and Opinions Surveys Conducted for the U.S. Department of Energy Hydrogen Program

    SciTech Connect (OSTI)

    Schmoyer, R. L.; Truett, Tykey; Cooper, Christy; Chew, Andrea

    2010-04-01

    This report presents results of a 2008/2009 survey of hydrogen and fuel cell awareness conducted for the U.S. Department of Energy (DOE). The 2008/2009 survey follows up on a similar DOE survey conducted in 2004, measuring levels of awareness and understanding of hydrogen and fuel cell technologies in four populations: (1) the general public, (2) students, (3) personnel in state and local governments, and (4) potential end users of hydrogen and fuel cell technologies in business and industry. The 2008/2009 survey includes these four groups and adds a fifth group, safety and code officials. The same survey methods were used for both surveys; the 2008/2009 survey report includes a comparison of 2004 and 2008/2009 findings. Information from these surveys will be used to enhance hydrogen and fuel cell education strategies.

  14. The darkside multiton detector for the direct dark matter search

    SciTech Connect (OSTI)

    Aalseth, C. E.; Agnes, P.; Alton, A.; Arisaka, K.; Asner, D. M.; Back, H. O.; Baldin, B.; Biery, K.; Bonfini, G.; Bossa, M.; Brigatti, A.; Brodsky, J.; Budano, F.; Cadonati, L.; Cadoni, M.; Calaprice, F.; Canci, N.; Candela, A.; Cao, H.; Cariello, M.; Cavalcante, P.; Chepurnov, A.; Cocco, A. G.; Condon, C.; Crippa, L.; D’Angelo, D.; D’Incecco, M.; Davini, S.; De Deo, M.; Derbin, A.; Devoto, A.; Di Eusanio, F.; Edkins, E.; Empl, A.; Fan, A.; Fiorillo, G.; Fomenko, K.; Forster, G.; Foxe, M.; Franco, D.; Gabriele, F.; Galbiati, C.; Goretti, A.; Grandi, L.; Gromov, M.; Guan, M. Y.; Guardincerri, Y.; Hackett, B.; Herner, K.; Hime, A.; Humble, P.; Hungerford, E.; Ianni, Al.; Ianni, An.; Jaffe, D. E.; Jollet, C.; Keeter, K.; Kendziora, C.; Kidner, S.; Kobychev, V.; Koh, G.; Korablev, D.; Korga, G.; Kurlej, A.; Li, P. X.; Lissia, M.; Lombardi, P.; Ludhova, L.; Luitz, S.; Lukyachenko, G.; Ma, Y. Q.; Machulin, I.; Mandarano, A.; Mari, S. M.; Maricic, J.; Marini, L.; Markov, D.; Martoff, J.; Meregaglia, A.; Meroni, E.; Meyers, P. D.; Miletic, T.; Milincic, R.; Montuschi, M.; Monzani, M. E.; Mosteiro, P.; Mount, B.; Muratova, V.; Musico, P.; Montanari, D.; Nelson, A.; Odrowski, S.; Odrzywolek, A.; Orrell, J. L.; Orsini, M.; Ortica, F.; Pagani, L.; Pallavicini, M.; Pantic, E.; Parmeggiano, S.; Parsells, B.; Pelczar, K.; Pelliccia, N.; Perasso, S.; Perasso, L.; Pocar, A.; Pordes, S.; Pugachev, D.; Qian, H.; Randle, K.; Ranucci, G.; Razeto, A.; Recine, K.; Reinhold, B.; Renshaw, A.; Romani, A.; Rossi, N.; Rossi, B.; Rountree, S. D.; Sablone, D.; Saggese, P.; Saldanha, R.; Sands, W.; Sangiorgio, S.; Segreto, E.; Semenov, D.; Shields, E.; Skorokhvatov, M.; Smallcomb, M.; Smirnov, O.; Sotnikov, A.; Suvurov, Y.; Tartaglia, R.; Tatarowicz, J.; Testera, G.; Tonazzo, A.; Unzhakov, E.; Vogelaar, R. B.; Wada, M.; Walker, S. E.; Wang, H.; Wang, Y.; Watson, A. W.; Westerdale, S.; Williams, R.; Wojcik, M.; Xu, J.; Yang, C. G.; Yoo, J.; Yu, B.; Zavatarelli, S.; Zhong, W. L.; Zuzel, G.

    2015-01-01

    Although the existence of dark matter is supported by many evidences, based on astrophysical measurements, its nature is still completely unknown. One major candidate is represented by weakly interacting massive particles (WIMPs), which could in principle be detected through their collisions with ordinary nuclei in a sensitive target, producing observable low-energy (<100 keV) nuclear recoils. The DarkSide program aims at the WIPMs detection using a liquid argon time projection chamber (LAr-TPC). In this paper we quickly review the DarkSide program focusing in particular on the next generation experiment DarkSide-G2, a 3.6-ton LAr-TPC. The different detector components are described as well as the improvements needed to scale the detector from DarkSide-50 (50 kg LAr-TPC) up to DarkSide-G2. Finally, the preliminary results on background suppression and expected sensitivity are presented.

  15. The darkside multiton detector for the direct dark matter search

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aalseth, C. E.; Agnes, P.; Alton, A.; Arisaka, K.; Asner, D. M.; Back, H. O.; Baldin, B.; Biery, K.; Bonfini, G.; Bossa, M.; et al

    2015-01-01

    Although the existence of dark matter is supported by many evidences, based on astrophysical measurements, its nature is still completely unknown. One major candidate is represented by weakly interacting massive particles (WIMPs), which could in principle be detected through their collisions with ordinary nuclei in a sensitive target, producing observable low-energy (<100 keV) nuclear recoils. The DarkSide program aims at the WIPMs detection using a liquid argon time projection chamber (LAr-TPC). In this paper we quickly review the DarkSide program focusing in particular on the next generation experiment DarkSide-G2, a 3.6-ton LAr-TPC. The different detector components are described as wellmore » as the improvements needed to scale the detector from DarkSide-50 (50 kg LAr-TPC) up to DarkSide-G2. Finally, the preliminary results on background suppression and expected sensitivity are presented.« less

  16. Survey and alignment of high energy physics accelerators and transport lines

    SciTech Connect (OSTI)

    Ruland, R.E.

    1992-11-01

    This talk summarizes the survey and alignment processes of accelerators and transport lines and discusses the propagation of errors associated with these processes. The major geodetic principles governing the survey and alignment measurement space are revisited and their relationship to a lattice coordinate system shown. The paper continues with a broad overview about the activities involved in the step by step sequence from initial absolute alignment to final smoothing. Emphasis is given to the relative alignment of components, in particular to the importance of incorporating methods to remove residual systematic effects in surveying and alignment operations.

  17. DC Resistivity Survey (Mise-A-La-Masse) | Open Energy Information

    Open Energy Info (EERE)

    fluid type and phase state of the pore water Thermal: Resistivity influenced by temperature Dictionary.png DC Resistivity Survey (Mise-A-La-Masse): No definition has been...

  18. Response to FESAC survey, Non-Fusion Connections to Fusion Energy...

    Office of Scientific and Technical Information (OSTI)

    Citation Details In-Document Search Title: Response to FESAC survey, Non-Fusion ... Due to the iconic status of the pillars of the Eagle Nebula, this research will bring ...

  19. PIA - Form EIA-475 A/G Residential Energy Consumption Survey...

    Energy Savers [EERE]

    Survey (390.38 KB) More Documents & Publications FOIA Responses processed by DOE HQ in 2009 PIA - WEB iPASS System DOE PIA PIA - Security Clearance Work Tracking and Budget

  20. Technical support document: Survey data used in revising the energy conservation requirements in the manufactured home construction and safety standards

    SciTech Connect (OSTI)

    Lee, A.D.; Conner, C.C.

    1992-02-01

    This report documents data used in the development of revised energy conservation standards for manufactured housing. The approach used in developing the proposed standard revision is a cost-benefit analysis in which the costs of energy conservation measures (ECM) are balanced against the benefits of energy savings. The analysis used to develop the recommendations for revision of the US Department of Housing and Urban Development (HUD) energy conservation standards for manufactured housing requires information on specific ECMs. This technical support document contains the data from two of the three surveys that were used primarily to characterize the available ECMs and their associated costs. The analyses of these data are provided in separate reports. 5 refs.

  1. Modeling plant-level industrial energy demand with the Manufacturing Energy Consumption Survey (MECS) database and the Longitudinal Research Database (LRD)

    SciTech Connect (OSTI)

    Boyd, G.A.; Neifer, M.J.; Ross, M.H.

    1992-08-01

    This report discusses Phase 1 of a project to help the US Department of Energy determine the applicability of the Manufacturing Energy Consumption Survey (MECS) database and the Longitudinal Research Database (LRD) for industrial modeling and analysis. Research was conducted at the US Bureau of the Census; disclosure of the MECS/LRD data used as a basis for this report was subject to the Bureau`s confidentiality restriction. The project is designed to examine the plant-level energy behavior of energy-intensive industries. In Phase 1, six industries at the four-digit standard industrial classification (SIC) level were studied. The utility of analyzing four-digit SIC samples at the plant level is mixed, but the plant-level structure of the MECS/LRD makes analyzing samples disaggregated below the four-digit level feasible, particularly when the MECS/LRD data are combined with trade association or other external data. When external data are used, the validity of using value of shipments as a measure of output for analyzing energy use can also be examined. Phase 1 results indicate that technical efficiency and the distribution of energy intensities vary significantly at the plant level. They also show that the six industries exhibit monopsony-like behavior; that is, energy prices vary significantly at the plant level, with lower prices being correlated with a higher level of energy consumption. Finally, they show to what degree selected energy-intensive products are manufactured outside their primary industry.

  2. Vector field models of modified gravity and the dark sector

    SciTech Connect (OSTI)

    Zuntz, J.; Ferreira, P. G.; Zlosnik, T. G; Bourliot, F.; Starkman, G. D.

    2010-05-15

    We present a comprehensive investigation of cosmological constraints on the class of vector field formulations of modified gravity called generalized Einstein-aether models. Using linear perturbation theory we generate cosmic microwave background and large-scale structure spectra for general parameters of the theory, and then constrain them in various ways. We investigate two parameter regimes: a dark matter candidate where the vector field sources structure formation, and a dark energy candidate where it causes late-time acceleration. We find that the dark matter candidate does not fit the data, and identify five physical problems that can restrict this and other theories of dark matter. The dark energy candidate does fit the data, and we constrain its fundamental parameters; most notably we find that the theory's kinetic index parameter n{sub ae} can differ significantly from its {Lambda}CDM value.

  3. Traveling dark solitons in superfluid Fermi gases

    SciTech Connect (OSTI)

    Liao Renyuan; Brand, Joachim

    2011-04-15

    Families of dark solitons exist in superfluid Fermi gases. The energy-velocity dispersion and number of depleted particles completely determine the dynamics of dark solitons on a slowly varying background density. For the unitary Fermi gas, we determine these relations from general scaling arguments and conservation of local particle number. We find solitons to oscillate sinusoidally at the trap frequency reduced by a factor of 1/{radical}(3). Numerical integration of the time-dependent Bogoliubov-de Gennes equation determines spatial profiles and soliton-dispersion relations across the BEC-BCS crossover, and proves consistent with the scaling relations at unitarity.

  4. Big Questions: Dark Matter

    SciTech Connect (OSTI)

    Lincoln, Don

    2013-12-05

    Carl Sagan's oft-quoted statement that there are "billions and billions" of stars in the cosmos gives an idea of just how much "stuff" is in the universe. However scientists now think that in addition to the type of matter with which we are familiar, there is another kind of matter out there. This new kind of matter is called "dark matter" and there seems to be five times as much as ordinary matter. Dark matter interacts only with gravity, thus light simply zips right by it. Scientists are searching through their data, trying to prove that the dark matter idea is real. Fermilab's Dr. Don Lincoln tells us why we think this seemingly-crazy idea might not be so crazy after all.

  5. Asymmetric twin Dark Matter

    SciTech Connect (OSTI)

    Farina, Marco

    2015-11-09

    We study a natural implementation of Asymmetric Dark Matter in Twin Higgs models. The mirroring of the Standard Model strong sector suggests that a twin baryon with mass around 5 GeV is a natural Dark Matter candidate once a twin baryon number asymmetry comparable to the SM asymmetry is generated. We explore twin baryon Dark Matter in two different scenarios, one with minimal content in the twin sector and one with a complete copy of the SM, including a light twin photon. The essential requirements for successful thermal history are presented, and in doing so we address some of the cosmological issues common to many Twin Higgs models. The required interactions we introduce predict signatures at direct detection experiments and at the LHC.

  6. Big Questions: Dark Matter

    ScienceCinema (OSTI)

    Lincoln, Don

    2014-08-07

    Carl Sagan's oft-quoted statement that there are "billions and billions" of stars in the cosmos gives an idea of just how much "stuff" is in the universe. However scientists now think that in addition to the type of matter with which we are familiar, there is another kind of matter out there. This new kind of matter is called "dark matter" and there seems to be five times as much as ordinary matter. Dark matter interacts only with gravity, thus light simply zips right by it. Scientists are searching through their data, trying to prove that the dark matter idea is real. Fermilab's Dr. Don Lincoln tells us why we think this seemingly-crazy idea might not be so crazy after all.

  7. Making beam splitters with dark soliton collisions

    SciTech Connect (OSTI)

    Steiglitz, Ken

    2010-10-15

    We show with numerical simulations that for certain simple choices of parameters, the waveguides induced by colliding dark solitons in a Kerr medium yield a complete family of beam splitters for trapped linear waves, ranging from total transmission to total deflection. The way energy is transferred from one waveguide to another is similar to that of a directional coupler, but no special fabrication is required. Dark soliton beam splitters offer potential advantages over their bright soliton counterparts: Their transfer characteristics do not depend on the relative phase or speed of the colliding solitons; dark solitons are generally more robust than bright solitons; and the probe peaks at nulls of the pump, enhancing the signal-to-noise ratio for probe detection. The last factor is especially important for possible application to quantum information processing.

  8. Secrets of the Dark Universe: Simulating the Sky on the Blue Gene/Q

    SciTech Connect (OSTI)

    2012-09-13

    An astonishing 99.6% of our Universe is dark. Observations indicate that the Universe consists of 70% of a mysterious dark energy and 25% of a yet unidentified dark matter component, and only 0.4% of the remaining ordinary matter is visible. Understanding the physics of this dark sector is the foremost challenge in cosmology today. Sophisticated simulations of the evolution of the Universe play a crucial task in this endeavor.

  9. Fermilab | Newsroom | Press Releases | August 18, 2014: Dark...

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

    Fermilab Photos photo Download image: Med Res | Hi Res This image of the NGC 1398 galaxy was taken with the Dark Energy Camera. This galaxy lives in the Fornax cluster,...

  10. Can WIMP dark matter overcome the nightmare scenario? (Journal...

    Office of Scientific and Technical Information (OSTI)

    Even if new physics beyond the standard model indeed exists, the energy scale of new ... In the nightmare scenario, we introduce a WIMP dark matter singlet under the standard ...

  11. The Search for Dark Matter

    ScienceCinema (OSTI)

    Orrell, John

    2014-07-24

    More than 25 years ago, PNNL scientists began the first underground measurements searching for dark matter using specialized radiation detector technology. Dark matter is yet to be discovered says Physicist John L. Orrell.

  12. The Search for Dark Matter

    SciTech Connect (OSTI)

    Orrell, John

    2013-11-20

    More than 25 years ago, PNNL scientists began the first underground measurements searching for dark matter using specialized radiation detector technology. Dark matter is yet to be discovered says Physicist John L. Orrell.

  13. STEP Participant Survey Executive Summary

    Broader source: Energy.gov [DOE]

    STEP Participant Survey Executive Summary, from the Tool Kit Framework: Small Town University Energy Program (STEP).

  14. Inflatable Dark Matter

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    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, without the need to tune underlying parameters or to appeal to anthropic considerations. 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 non-thermal abundance of GUTmore » or Planck scale axions can be brought to acceptable levels, without invoking anthropic tuning of initial conditions. Additionally, 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.« less

  15. Inflatable Dark Matter

    SciTech Connect (OSTI)

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

    2015-07-30

    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, without the need to tune underlying parameters or to appeal to anthropic considerations. 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 non-thermal abundance of GUT or Planck scale axions can be brought to acceptable levels, without invoking anthropic tuning of initial conditions. Additionally, 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.

  16. Inflatable dark matter

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Davoudiasl, Hooman; Hooper, Dan; McDermott, Samuel

    2016-01-22

    Here, 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 levelsmore » 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.« less

  17. Hidden sector monopole, vector dark matter and dark radiation with Higgs portal

    SciTech Connect (OSTI)

    Baek, Seungwon; Ko, P.; Park, Wan-Il E-mail: pko@kias.re.kr

    2014-10-01

    We show that the 't Hooft-Polyakov monopole model in the hidden sector with Higgs portal interaction makes a viable dark matter model, where monopole and massive vector dark matter (VDM) are stable due to topological conservation and the unbroken subgroup U(1 {sub X}. We show that, even though observed CMB data requires the dark gauge coupling to be quite small, a right amount of VDM thermal relic can be obtained via s-channel resonant annihilation for the mass of VDM close to or smaller than the half of SM higgs mass, thanks to Higgs portal interaction. Monopole relic density turns out to be several orders of magnitude smaller than the observed dark matter relic density. Direct detection experiments, particularly, the projected XENON1T experiment, may probe the parameter space where the dark Higgs is lighter than ∼< 50 GeV. In addition, the dark photon associated with the unbroken U(1 {sub X} contributes to the radiation energy density at present, giving Δ N{sub eff}{sup ν} ∼ 0.1 as the extra relativistic neutrino species.

  18. Household energy use in urban Venezuela: Implications from surveys in Maracaibo, Valencia, Merida, and Barcelona-Puerto La Cruz

    SciTech Connect (OSTI)

    Figueroa, M.J.; Sathaye, J.

    1993-08-01

    This report identifies the most important results of a comparative analysis of household commercial energy use in Venezuelan urban cities. The use of modern fuels is widespread among all cities. Cooking consumes the largest share of urban household energy use. The survey documents no use of biomass and a negligible use of kerosene for cooking. LPG, natural gas, and kerosene are the main fuels available. LPG is the fuel choice of low-income households in all cities except Maracaibo, where 40% of all households use natural gas. Electricity consumption in Venezuela`s urban households is remarkably high compared with the levels used in households in comparable Latin American countries and in households of industrialized nations which confront harsher climatic conditions and, therefore, use electricity for water and space heating. The penetration of appliances in Venezuela`s urban households is very high. The appliances available on the market are inefficient, and there are inefficient patterns of energy use among the population. Climate conditions and the urban built form all play important roles in determining the high level of energy consumption in Venezuelan urban households. It is important to acknowledge the opportunities for introducing energy efficiency and conservation in Venezuela`s residential sector, particularly given current economic and financial constraints, which may hamper the future provision of energy services.

  19. Self-interacting asymmetric dark matter coupled to a light massive...

    Office of Scientific and Technical Information (OSTI)

    Moreover, we estimate the cosmological abundance of dark photons in various regimes, and ... Country of input: International Atomic Energy Agency (IAEA) Country of Publication: ...

  20. DOE/EIA-0272/S The National Interim Energy Consumption Survey...

    U.S. Energy Information Administration (EIA) Indexed Site

    Exploring the Variability in Energy Consumption, (DOEEIA-0272). A discussion on the theory behind the particular form of the models chosen and the choice of the independent...